ISSN 0006-2979, Biochemistry (Moscow), 2026, Vol. 91, No. 5, pp. 800-815 © Pleiades Publishing, Ltd., 2026.
800
Effect of the PPARγ Agonist Pioglitazone
on Rat Behavior and Expression
of Epileptogenesis-Related Genes during
the Latent Phase of the Lithium-Pilocarpine Model
Adeliya R. Kharisova
1#
, Olga E. Zubareva
1,a
*
#
, Anna A. Kovalenko
1
,
Denis S. Sinyak
1
, and Aleksey V. Zaitsev
1
1
Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences,
194223 Saint Petersburg, Russia
a
e-mail: ZubarevaOE@mail.ru
Received February 2, 2026
Revised April 22, 2026
Accepted April 24, 2026
Abstract— Epilepsy is a severe chronic condition that remains pharmacoresistant in approximately 30% of
the patients, which necessitates the search for new treatment approaches. Epileptogenesis involves disruption
in the interaction between metabolic pathways and neuronal signaling. A promising therapeutic target is the
peroxisome proliferator-activated receptors (PPARs), which integrate metabolic and anti-inflammatory signals.
Theaim of this work was to evaluate effects of the PPARγ agonist pioglitazone on the complex of epileptogenesis
manifestations: behavior and expression of the genes encoding glial markers, cytokines, neurotrophic factors,
and glutamate receptor subunits during the latent phase of the lithium-pilocarpine model in rats. The study
was conducted with 8-week-old male Wistar rats divided into control and experimental groups. Pioglitazone was
administered at low doses (7 mg/kg after status epilepticus, followed by 1 mg/kg/day for 7 days). On the days 8-9,
locomotor and social activities were assessed using the Open Field and Social Interaction tests. Onthe day 10,
expression of the genes encoding markers for activation and various states of astro- and microglia, cytokines,
neurotrophic factors, and glutamate receptor subunits was analyzed in the dorsal hippocampus and temporal
cortex using RT-qPCR. Itwas shown that pioglitazone partially alleviated the pilocarpine-induced social deficit.
In the brain of rats with the epilepsy model, increased expression of the glial activation markers (Gfap, Aif1)
and cytokines (Il1b, Il1rn) was found, which was weakly affected by administration of pioglitazone. At the same
time, the drug completely prevented the pilocarpine-induced decrease in the expression of the glutamate recep-
tor subunit gene Grin2b. The obtained data suggest that, at the applied doses, pioglitazone primarily modulates
expression of the genes related to synaptic plasticity and does not exert a significant effect on expression of
the genes associated with glial activation and inflammation. Thus, activation of PPARγ as a metabolic sensor
during epileptogenesis could stabilize transcriptional programs that are important for maintaining synaptic
homeostasis, which opens the possibilities for targeted modulation of metabolic pathways in epilepsy therapy.
DOI: 10.1134/S0006297926600183
Keywords: pioglitazone, PPARγ, temporal lobe epilepsy, lithium-pilocarpine model, astroglia, microglia, gene
expression, neuroinflammation, glutamate receptors, behavior
* To whom correspondence should be addressed.
# These authors contributed equally to this study.
INTRODUCTION
Epilepsy is a severe chronic disorder character-
ized by the development of spontaneous recurrent
seizures and associated behavioral disturbances.
Up to 30% of the patients with epilepsy are resis-
tant to current therapies, necessitating the search
for novel treatment approaches [1]. The underly-
ing basis of this process is pathological interac-
tion between the disrupted neuronal signaling (pri-
marily imbalance between the glutamatergic and
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BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
GABAergic systems) and severe metabolic remodel-
ing [2, 3].
Glial cells play a key role in mediating this inter-
play, as they not only maintain homeostasis but also
actively regulate neuroinflammation and cerebral en-
ergy metabolism [3, 4].
Dysfunction of astrocytes and microglia, often
described as their shift toward pro-inflammatory
phenotypes (M1/A1), is accompanied by metabolic re-
programming [5]. These phenotypes support neuroin-
flammation and create energy deficit in neurons, thus
reducing the seizure threshold [6]. Glial cells could
also exert protective functions by shifting toward
anti-inflammatory phenotypes (M2/A2) that promote
neural tissue repair [7, 8]. Therefore, a promising
therapeutic approach lies in identifying drugs that
could shift glial activity from a pro-inflammatory to
a protective phenotype via concurrent modulation of
both the glial metabolic state and neuroinflammation.
Agonists of the peroxisome proliferator-activated
receptors (PPARs α, β/δ, and γ) – a family of nuclear
transcription factors that function as key metabolic
sensors – exhibit precisely these properties. PPARs co-
ordinately regulate lipid and energy metabolism, as
well as inflammatory and oxidative stress signaling
cascades [9]. PPAR activation is considered one of the
key mechanisms underlying efficacy of ketogenic diet
in the drug-resistant epilepsy [10]. Antiepileptic prop-
erties of the PPAR agonists have been demonstrated
in the pentylenetetrazole- and pilocarpine-induced
seizure models [11, 12]. Their neuroprotective effects
are thought to be mediated through regulation of the
glial energy metabolism [5], reversal of the mitochon-
drial dysfunction [13], suppression of neuroinflamma-
tion (including inhibition of the transcription factor
NF-κB) [14], and attenuation of oxidative stress [15].
Pleiotropic neuroprotective and anti-inflammato-
ry properties in the acute seizure models have been
demonstrated for the selective PPARγ agonist piogli-
tazone (PG) [11], a drug used in clinical practice for
treatment of the type 2 diabetes. PG affects function-
al activity of the NMDA-type glutamate receptors [16],
which play a key role in epileptogenesis [2]. However,
impact of PG on expression of the genes of glutamate
receptor and glial proteins during epileptogenesis re-
mains largely unexplored.
The aim of this study was to evaluate the effect of
the PPARγ agonist pioglitazone on behavioral and mo-
lecular alterations during the latent phase of the lithi-
um-pilocarpine model in rats. We assessed behavioral
responses and expression of the genes associated with
glial activation and neuroinflammation, neurotrophic
factors, and glutamate receptor subunits in the brain
tissue. This model was selected because it reliably re-
produces the key features of temporal lobe epilepsy,
including neuroinflammation at this stage [17].
MATERIALS AND METHODS
Animals and work with them. Forty-one (41)
8-week-old male Wistar rats weighing 200-230 g, ob-
tained from the vivarium of the Sechenov Institute
of Evolutionary Physiology and Biochemistry, Russian
Academy of Sciences (IEPhB RAS) were used in the
study, animals were housed under standard laborato-
ry conditions. The animals were randomly assigned to
four groups: (1) control (Ctrl, n = 9); (2) control treat-
ed with PG (Ctrl + PG, n = 6); (3) lithium-pilocarpine
model of epilepsy (Pilo, initial n = 12, final n = 9);
(4) lithium-pilocarpine model of epilepsy treated with
PG (Pilo + PG, initial n = 14, final n = 11).
Lithium-pilocarpine model of temporal lobe
epilepsy. Rats were injected with LiCl (127 mg/kg,
i.p.). Twenty-four hours later, premedication with sco-
polamine methyl bromide (1 mg/kg, i.p.) was adminis-
tered to prevent peripheral effects of pilocarpine. One
hour later, status epilepticus (SE) was induced by re-
peated injections of pilocarpine (initial dose 10 mg/kg,
i.p., at 30-min intervals) until stage 4 seizures accord-
ing to the Racine scale were achieved [18]. SE was
terminated with diazepam (10 mg/kg, i.p.) 90 min af-
ter onset of the stage 4 seizures. Animals that failed
to develop seizures after a cumulative pilocarpine
dose of 40 mg/kg were excluded from the experiment
(<5%). Control rats received LiCl only. This protocol
has previously been shown to lead to the develop-
ment of spontaneous recurrent seizures in the chron-
ic phase [19].
PG (TCI, Japan) was dissolved in DMSO and ad-
ministered intraperitoneally (i.p.) at a volume of
0.1 mL per 100 g body weight. The PG dosing regi-
men was as follows: a loading dose of 7 mg/kg at 2 h
after SE termination, followed by a maintenance dose
of 1 mg/kg/day for 7 days. The control group received
an equivalent volume of DMSO. During the first 24 h
after pilocarpine administration, mortality was up
to 30%. To support recovery, animals were provided
with moist chow.
Unlike the prophylactic administration of PPARγ
agonists prior to pilocarpine [20], we administered
PG after SE termination to model therapeutic inter-
vention during the latent period of epileptogenesis.
The 7-day treatment course was chosen because
the peak of glial activation occurs during the first
week following induction of the lithium-pilocarpine
model [21]. The maintenance dose of 1 mg/kg/day was
based on evidence of an elevated seizure threshold
in mice following its chronic administration [22].
Loading dose of 7 mg/kg administered as the first
injection was aimed at suppressing the peak of neu-
roinflammation (IL-1β and TNF release) in the first
hours after SE to maximize therapeutic effect within
the “therapeutic window”.
KHARISOVA et al.802
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
Behavioral testing. On days 8-9 after SE, during
the dark phase of the light-dark cycle (20:00-23:00 h),
behavior was assessed using the Open Field Test
and the Social Interaction Test. These tests are sen-
sitive to epileptic disturbances and neuroinflamma-
tion [19]. Video recordings were analyzed by a re-
searcher blinded to group assignment using Field4
and Pole_Krest software (Institute of Experimental
Medicine, St. Petersburg, Russia). In the Open Field
Test (circular arena, 1 m in diameter, illumination
8 lux, 5-min recording), the following parameters
were assessed: locomotor activity (distance traveled,
duration of movement), exploratory activity (support-
ed rears), and anxiety-related behavior (time spent
in the central zone, duration of grooming, freezing,
and unsupported rears). In the Social Interaction Test
(a cage 60×30×40 cm, 24-h habituation of the resi-
dent to the setup, 5-min interaction with an unfa-
miliar intact male), the following resident behaviors
were analyzed: aggressive (attacks, threats), commu-
nicative (sniffing, partner grooming), defensive, and
anxiety-related (grooming).
Real-time reverse transcription polymerase
chain reaction (RT-qPCR). On day 10 after SE, rats
were decapitated, and brains were rapidly removed,
frozen, and stored at −80°C. For molecular analysis,
dorsal hippocampus and temporal cortex were dis-
sected using an OTF5000 cryostat (Bright Instrument,
UK) according to the stereotaxic atlas [23].
Real-time RT-qPCR was used to analyze gene
expression at the mRNA level. All steps of sample
preparation were described in detail previously [24].
PCR was performed using a C1000 Touch thermal
cycler with a CFX384 Touch™ detection system (Bio-
Rad, USA) in a total volume of 6 μL, containing 0.8 μL
of cDNA, 0.5 units of TaqM polymerase (Alkor Bio,
Russia), 3.5 mM MgCl
2
, and gene-specific forward and
reverse primers, and probes (the primer and probe
sequences are listed in Online Resource 1), manu-
factured by DNA-Synthesis LLC (Russia). All samples
were analyzed in quadruplicate. In the present study,
we performed a comprehensive assessment of the
effect of PG on the expression of a broad panel of
genes involved in the regulation of epileptogenesis:
(1) markers of astroglial (Gfap) and microglial (Aif1)
activation; (2) pro-inflammatory (Il1b, Tnfa) and an-
ti-inflammatory (Il1rn) cytokines; (3) genes associated
with reactive glial and macrophage phenotypes (Lcn2,
S100a10, Nos2, Nlrp3, Arg1). Lcn2 was considered as
a marker of the neurotoxic response, expressed in as-
trocytes and microglia/infiltrating cells; S100a10– as
a marker of the neuroprotective astroglial phenotype;
Nos2 and Nlrp3 – as markers of pro-inflammatory
(M1-like), and Arg1 – as a marker of anti-inflam-
matory (M2-like) microglial/macrophage activation;
(4) neurotrophic factors Fgf 2, Bdnf, Tgf b1; (5) subunits
of glutamate NMDA receptors (Grin1, Grin2a, Grin2b)
and AMPA receptors (Gria1, Gria2). Gene name abbre-
viations are provided in Online Resource 1.
Relative expression of the genes of interest was
calculated using the 2
–∆∆Ct
method [25]. Data were
normalized to the geometric mean of the expres-
sion of the three most stable reference genes, se-
lected under conditions of the present experiment
from nine housekeeping genes (Gapdh, Actb, Rpl13a,
B2m, Pgk1, Ppia, Hprt1, Ywhaz, Sdha) using the on-
line tool RefFinder® (https://ciidirsinaloa.com.mx/
RefFinder-master/): Actb, Hprt1, Pgk1 for the dorsal
hippocampus; Rpl13a, Sdha, Ppia for the temporal
cortex.
Statistical analysis. Statistical analysis was per-
formed using IBM SPSS Statistics 23.0 and GraphPad
Prism 9.0 software. Normality of data distribution was
assessed using the Kolmogorov–Smirnov test; outliers
were identified using the interquartile range method,
and homogeneity of variances across groups was veri-
fied by the Levene’s test. The required sample size was
estimated a priori using G*Power 3.1 software with a
significance level of α = 0.05 and power of 80%.
Changes in body weight over time were analyzed
using three-way mixed-design analysis of variance
(Mixed ANOVA) with the factors “Model,” “Treat-
ment”, and “Day of testing.” Survival analysis was
performed using the Kaplan–Meier method and the
log-rank test. To test the hypothesis regarding the ef-
fect of PG on behavioral and molecular alterations
in experimental and control rats, two-way analysis
of variance (two-way ANOVA) with the fixed factors
“Model” and “Treatment” was applied. When a sig-
nificant interaction between the factors was detected,
posthoc pairwise comparisons were performed using
the Sidak test.
Since we hypothesized that alterations could be
present in the untreated rats but not in treated an-
imals, we additionally used the method of planned
contrasts alongside the two-way ANOVA. Two compar-
isons were performed: (Ctrl vs. Pilo) in the untreat-
ed groups and (Ctrl+PG vs. Pilo+PG) in the treated
groups. Unlike the post hoc tests, planned contrasts
were performed regardless of the significance of
the interaction between the factors. To control for
type I error in multiple comparisons, the Bonfer-
roni correction was applied (adjusted significance
level α = 0.025). Data in the graphs are presented as
a mean ± standard deviation. Individual data points
represent values for individual animals.
RESULTS
Body weight dynamics and survival. Initial
body weight did not differ between the groups.
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Fig. 1. Body weight dynamics in the control (Ctrl) (a) and experimental (Pilo) (b) animals, and survival curves of the rats
with lithium-pilocarpine model of epilepsy untreated (Pilo) and treated with pioglitazone (Pilo+PG) (c). Ctrl – control, PG–
pioglitazone; * p < 0.05, Sidak post hoc test.
Following SE induction, animals with the epilepsy
model showed a 12-29% decrease in body weight com-
pared to the baseline values (Fig. 1, a, b). Three-way
mixed ANOVA revealed a significant main effect of
the factor “Model” (F
2,6; 76,8
= 5.3; p = 0.003), the factor
“Treatment” (F
2,6; 76,8
= 3.2; p = 0.032), and significant
“Day × Model × Treatment” interaction (F
2,6; 76,8
= 5.2;
p = 0.002). In the control groups, PG had no effect on
body weight. In the experimental animals, on days
6-7 after SE, body weight was significantly higher in
the Pilo+PG group than in the Pilo group (p < 0.05).
During the first 72 h after SE, mortality was 25%
(3/12) in the Pilo group and 21.4% (3/14) in the
Pilo+PG group. Kaplan–Meier survival analysis re-
vealed no significant differences between the groups
(Fig. 1c, χ
2
= 1.6; p = 0.21).
Behavioral analysis. In the Open Field Test
(Fig. 2, a-e), the rats with the lithium-pilocarpine
model showed increased locomotor activity as mea-
sured by locomotion time (factor “Model”: F
1,32
= 9;
p < 0.01; factor “Treatment”: F
1,32
= 4,0; p = 0.06;
“Model” × “Treatment” interaction: F
1,32
= 0,5; p =
= 0.49), planned contrasts revealed a significant dif-
ference between the Ctrl and Pilo groups (p = 0.01).
A similar trend was observed for another measure
of locomotor activity – distance traveled; however,
the differences did not reach statistical significance
(factor “Model”: F
1,30
= 3.1; p = 0.09).
Two-way ANOVA revealed a statistically signifi-
cant main effect of the factor “Model” on the time
spent in the center (F
1,31
= 4.8; p = 0.04) and duration
of grooming (F
1,31
= 9.9; p = 0.004), which may be in-
terpreted as an alteration in anxiety levels. The effect
of the factor “Treatment” and interaction between the
factors did not reach statistical significance (p > 0.05
for all cases). Planned contrasts revealed that, among
the PG-treated animals, grooming time was significant-
ly lower in the epilepsy model group compared to the
control group (Ctrl+PG vs. Pilo+PG; p < 0.01; Fig. 2e).
In the Social Interaction Test (Fig. 2, f, g), the
rats with the epilepsy model exhibited reduced com-
municative activity: interaction time was reduced by
a factor of 10 (F
1,30
= 61.9; p < 0.001), and the num-
ber of social contacts was reduced by a factor of 4.8
(F
1,31
= 26.9; p < 0.001). For the number of contacts,
a significant “Model × Treatment” interaction was
revealed (F
1,30
= 4.3; p < 0.05). Post hoc analysis re-
vealed differences between the Ctrl and Pilo groups
(p < 0.0001), but not between the Ctrl+PG and Pilo+PG
groups, suggesting a corrective effect of pioglitazone
on social behavior. Aggressive and defensive behav-
iors did not differ significantly between the groups.
Analysis of expression of the genes involved
in regulation of epileptogenesis. Genes of astroglial
and microglial/macrophage proteins. In the temporal
cortex, the lithium-pilocarpine model induced a sharp
increase in the expression of the astrocyte activation
marker gene (Gfap) and the microglial activation
marker gene (Aif1) (Fig. 3, b, d; effect of the model –
F
1,21
= 90.6; p < 0.001 and F
1,19
= 46.8; p < 0.0001, re-
KHARISOVA et al.804
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
Fig. 2. Behavior of control (Ctrl) rats and rats with temporal lobe epilepsy model (Pilo) in the Open Field Test (a-e) and
the Social Interaction Test (f, g). a) Representative tracks in the Open Field. Ctrl – control, PG – pioglitazone; * p < 0.05,
** p < 0.01, *** p < 0.001, **** p < 0.0001, Sidak post hoc test(f) or planned contrasts within the analysis of variance (g).
spectively). PG administration did not prevent this
increase. In the dorsal hippocampus, two-way ANOVA
revealed a statistically significant main effect of the
factor “Treatment” on the mRNA levels of Gfap and
Aif1 (Fig. 3, a, c; F
1,23
= 5.9; p = 0.02 and F
1,23
= 5;
p = 0.04, respectively), however, pairwise comparisons
revealed no significant differences between the indi-
vidual groups.
In the animals with lithium-pilocarpine model
of epilepsy, expression of the pro-inflammatory gene
Il1b was unchanged in the dorsal hippocampus but
was increased in the temporal cortex (Fig. 4, a, b;
factor “Model”: F
1,20
= 16.8; p < 0.001); PG administra-
tion did not prevent this increase. Expression of the
anti-inflammatory gene Il1rn was increased in both
brain regions examined: in the dorsal hippocam-
pus (Fig. 4c; factor “Model”: F
1,24
= 45.3; p < 0.001)
and in the temporal cortex (Fig. 4d; factor “Model”:
F
1,22
= 11.6; p < 0.01). In the temporal cortex, two-way
ANOVA also revealed a statistically significant main
effect of the factor “Treatment” on the Il1rn expres-
sion (F
1,22
= 5.8; p = 0.03).
Expression of the Tnfa gene did not depend on
the factor “Model”; however, in the dorsal hippocam-
pus, a statistically significant main effect of the fac-
tor “Treatment” was revealed (Fig. 4e; PG: F
1,19
= 8.2;
p = 0.01).
Next, we analyzed expression of the genes asso-
ciated with pro-inflammatory (M1) and anti-inflam-
matory (M2) phenotypes of microglia/macrophages:
Nlrp3 and Nos2 (M1 markers) and Arg1 (M2 mark-
er) (Fig. 5). Two-way ANOVA revealed a statistical-
ly significant main effect of the factor “Model” on
the Nlrp3 gene expression in the temporal cortex
(F
1,20
= 11.7; p = 0.003), however, post hoc compari-
sons did not reach statistical significance (Fig. 5f).
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Fig. 3. Relative expression of the astrocyte activation marker gene Gfap (a, b) and the microglial activation marker gene
Aif1 (c, d) in the dorsal hippocampus and temporal cortex of experimental (Pilo) and control (Ctrl) rats. PG – pioglitazone;
** p < 0.01; *** p < 0.001; **** p < 0.0001, planned contrasts within the analysis of variance.
Fig. 4. a-f)Relative expression of pro- and anti-inflammatory cytokine genes in the dorsal hippocampus and temporal cor-
tex of experimental (Pilo) and control (Ctrl) rats. PG – pioglitazone; * p < 0.05, ** p < 0.01, *** p < 0.001, planned contrasts
within the analysis of variance.
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BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
Fig. 5. a-j)Relative expression of microglial and astroglial protein genes in the dorsal hippocampus and temporal cortex of
experimental (Pilo) and control (Ctrl) rats. PG – pioglitazone; * p < 0.05, ** p < 0.01, **** p < 0.0001, Sidak post hoc multiple
comparisons test or planned contrasts within the analysis of variance.
For the Nos2 gene in the temporal cortex, signifi-
cant main effects of the factors “Model” (F
1,19
= 22.6;
p < 0.001) and “Treatment” (F
1,19
= 5.6; p = 0.03) were
observed, as well as their interaction (F
1,19
= 12.3;
p = 0.002; Fig. 5g). Post hoc analysis revealed that in
the untreated animals with the epilepsy model, Nos2
expression was reduced compared to the control
(p < 0.001), whereas in the PG-treated animals this
decrease was not observed (difference between the
Pilo and Pilo+PG groups: p < 0.01).
In the animals with the epilepsy model, expres-
sion of the Arg1 gene was reduced in both struc-
tures examined (Fig. 5, c, h; dorsal hippocampus:
F
1,20
= 27.2; p < 0.0001; temporal cortex: F
1,23
= 9.4;
p = 0.006). In the dorsal hippocampus, the changes
were unidirectional in the Pilo and Pilo+PG groups,
whereas in the temporal cortex, according to the
planned contrasts analysis, reduction was more
pronounced in the PG-treated animals (p < 0,05).
In contrast to Nos2, no significant effect of the fac-
tor “Treatment” was detected by two-way ANOVA for
the Nlrp3 and Arg1 genes.
Next, we analyzed expression levels of the Lcn2
gene (marker of neurotoxic response in astrocytes
and microglia/infiltrating cells) and of the S100a10
gene (marker of the neuroprotective astroglial phe-
notype). In the animals with the epilepsy model,
the Lcn2 expression was increased in the dorsal
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Fig. 6. a-f) Relative expression of growth factor and neurotrophic protein genes in the dorsal hippocampus and temporal
cortex of experimental (Pilo) and control (Ctrl) rats. PG– pioglitazone; * p < 0.05, ** p < 0.01, *** p < 0.001, planned contrasts
within the analysis of variance.
hippocampus (Fig. 5d; factor “Model”: F
1,23
= 11.2;
p < 0.01). According to the planned contrasts analysis,
a statistically significant increase was observed only
in the Pilo group (without PG treatment). Expres-
sion of the neuroprotective gene S100a10 was also
increased in the dorsal hippocampus (Fig. 5e; factor
“Model”: F
1,21
= 24.7; p < 0.001) and in the temporal
cortex (Fig. 5j; factor “Model”: F
1,24
= 15.6; p < 0.001).
The planned contrasts analysis revealed that in the
hippocampus, increase in the S100a10 expression was
significant in both epilepsy model groups, whereas in
the temporal cortex it reached statistical significance
only in the PG-treated animals.
Overall, analysis of expression of the astroglial
and microglial/macrophage marker genes revealed
their substantial alterations during the latent phase
of the lithium-pilocarpine model, with a more pro-
nounced response to the model observed in the
temporal cortex. PG administration did not prevent
most of the identified alterations; however, in some
cases (Lcn2 in the hippocampus, Nos2 in the cortex),
a modulatory effect of the drug was observed.
Expression of growth factor and neurotrophic
factor genes (Fig. 6). In the animals with the ep-
ilepsy model, expression of the Fgf2 (F
1,23
= 42.7;
p < 0.001), Bdnf(F
1,25
= 12.1; p = 0.002), and Tgf b1
(F
1,22
= 140.8; p < 0.001) genes was increased in the
dorsal hippocampus. For the Tgf b1 gene, increase in
expression was also observed in the temporal cor-
tex (F
1,24
= 17.7; p < 0.001). The planned contrasts
analysis revealed that the increase in the Bdnf ex-
pression was statistically significant only in the Pilo
group. In the dorsal hippocampus, PG administration
significantly attenuated the pilocarpine-induced in-
crease in the Fgf2 expression (factor “Treatment”:
F
1,23
= 19.9; p < 0.001; factor interaction: F
1,23
= 8.8;
p = 0.007), and post hoc comparisons revealed sig-
nificant differences between the Pilo and Pilo+PG
groups (p < 0.001). PG also influenced the Tgf b1 gene
expression in the dorsal hippocampus (F
1,22
= 4.7;
p = 0.04).
Thus, PG administration during the latent phase
of epileptogenesis attenuated the model-character-
istic increase in the Fgf2 expression in the dorsal
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Fig. 7. a-d)Relative expression of glutamate AMPA receptor subunit genes in the dorsal hippocampus and temporal cortex
of experimental (Pilo) and control (Ctrl) rats. PG– pioglitazone; * p < 0.05, ** p < 0.01, planned contrasts within the analy-
sis of variance.
Fig. 8. a-f) Relative expression of the glutamate NMDA receptor subunit genes in the dorsal hippocampus and temporal
cortex of the experimental (Pilo) and control (Ctrl) rats. PG – pioglitazone; *** p < 0.001, planned contrasts within the
analysis of variance.
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hippocampus. Atrend toward normalization was also
observed for the Bdnf gene.
Expression of glutamate AMPA and NMDA recep-
tor genes. Epileptogenesis was accompanied by the
decrease in expression of the AMPA receptor sub-
unit genes (Fig. 7) both in the dorsal hippocampus
(Model: Gria1 – F
1,24
= 6.3; p = 0.02; Gria2: F
1,22
= 19.2,
p < 0.01), and in the temporal cortex (Model: Gria1–
F
1,24
= 7.4; p = 0.01; Gria2: F
1,21
= 19.3; p < 0.001).
PG administration influenced the level of expression
of the AMPA receptor genes in the temporal cor-
tex (factor “Treatment”: Gria1– F
1,24
= 5.2; p = 0.03;
Gria2: F
1,21
= 10.8; p < 0.01).
Analysis of the NMDA receptor subunit expres-
sion (Fig. 8) revealed no substantial changes in the
Grin1 mRNA levels in either of the brain structures
examined. Atthe same time, the Grin2a gene expres-
sion was altered in the dorsal hippocampus (Model:
F
1,23
= 6.3; p = 0.02) and in the temporal cortex
(F
1,24
= 8; p < 0.01). The Grin2b gene expression was
altered in the dorsal hippocampus of the rats with
temporal lobe epilepsy (Model: F
1,22
= 12,5; p < 0.01).
Analysis of planned contrasts in the dorsal hippo-
campus revealed decrease in the Grin2b mRNA levels
only in the untreated model animals compared to the
control.
DISCUSSION
In the present study, we investigated the effect
of PG on behavioral and molecular alterations during
the latent phase of epileptogenesis. Animals with the
lithium-pilocarpine model of epilepsy exhibited char-
acteristic behavioral disturbances: increased locomo-
tor activity in the Open Field Test and impaired so-
cial interaction in the Social Interaction Test, which
is consistent with the published data on the early
development of behavioral disorders during epilep-
togenesis [26, 27]. PG administration attenuated the
pilocarpine-induced deficits in social behavior. A sim-
ilar effect of PG was previously demonstrated in the
febrile seizure model [28].
We also identified significant changes in the ex-
pression of the genes associated with neuroinflam-
mation. We observed marked activation of the glial
cells, as evidenced by the increased mRNA levels of
the astroglial marker Gfap and the microglial mark-
er Aif1 in the temporal cortex. These changes were
more pronounced in the cortex than in the hippo-
campus, which may reflect distinct dynamics of the
neuroinflammatory response during epileptogenesis.
GFAP is an established marker of reactive astroglio-
sis [29], and AIF1 reflects microglial activation [30].
Our data are consistent with numerous clinical and
experimental observations demonstrating persistent
glial activation in the temporal lobe epilepsy [4, 19].
Importantly, glial activation is not merely a second-
ary consequence of epileptic activity but also one of
the factors that sustain the pathological process and
promote disease progression through the persistence
of neuroinflammation [31]. PGadministration did not
significantly attenuate these changes.
Glial activation in our experiment was accompa-
nied by the increased expression of both pro-inflam-
matory (Il1b) and anti-inflammatory (Il1rn) cytokine
genes, which is consistent with the published data
[32, 33]. PG administration had a limited effect on
the expression of pro- and anti-inflammatory cyto-
kine genes, and no statistically significant intergroup
differences were detected). Previous studies using the
lithium-pilocarpine model and the pentylenetetra-
zole-induced acute seizure model have shown that
the PPARγ agonists suppress expression of the pro-in-
flammatory cytokine genes in the hippocampus [34,
35]. The less pronounced effect of PG on the expres-
sion of these genes in the present study may be at-
tributable to the relatively low dose of the drug used.
In interpreting the increased expression of the
Gfap and Aif1 genes, we considered these changes in
the context of glial polarization. Despite the growing
understanding of the spectrum of glial states [7, 36],
the markers we examined remain reference points
for identifying pro-inflammatory (M1/A1) and anti-in-
flammatory (M2/A2) phenotypes [7, 17]. Since previ-
ous studies have demonstrated the effect of PPARγ
agonists on polarization of the microglial [37] and
astroglial [38, 39] cells in various models of neuro-
pathology, we assessed the effect of PG on the ex-
pression of the genes associated with reactive glial
and macrophage phenotypes (Lcn2, S100a10, Nos2,
Nlrp3, Arg1). A small number of macrophages may
have been present in the samples, as our analysis
was performed on tissue homogenates.
The lithium-pilocarpine model of epilepsy was
associated with bidirectional changes in the M1/M2
phenotype markers, and magnitude and direction
of these changes differed depending on the brain
structure. In the temporal cortex, expression of the
Nlrp3 gene was increased, which is consistent with
the published data obtained in several models of ep-
ilepsy [17, 40]. No significant changes in the Nlrp3
gene expression were detected in the dorsal hippo-
campus, which may be attributable to the differences
in the time points of testing. Expression of the Arg1
gene was reduced in both structures; however, this
reduction was more pronounced in the hippocampus
(F
1,20
= 27.2; p < 0.0001) than in the cortex (F
1,23
= 9.4;
p = 0.006), which may reflect a more profound sup-
pression of the anti-inflammatory M2 mechanisms in
the hippocampus. Similar changes were identified in
our previous studies in the latent [32] and chronic [41]
KHARISOVA et al.810
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
phases of the model, as well as by Peng et al. [42].
Incontrast to expression of the Nlrp3 and Arg1 genes,
expression of the Nos2 gene was reduced in the cor-
tex, whereas no significant changes were observed in
the hippocampus. This is inconsistent with the pre-
viously described increase in iNOS during the acute
period of epileptogenesis [32]; this discrepancy may
be due to the differences in the time points of testing
and region-specific nature of the response. PG admin-
istration did not affect expression of the Nlrp3 or Arg1
genes in either structure, which differs from the find-
ings of Peng et al. [42], who demonstrated efficacy of
another PPARγ agonist, rosiglitazone. This discrepancy
may be explained by the differences in the drugs used.
We also analyzed expression of the Lcn2 gene
(a marker of the neurotoxic response in astrocytes
and microglia/infiltrating cells), and of the S100a10
gene (marker of the protective A2 astrocyte state).
Notably, both genes were simultaneously upregulated,
indicating concurrent activation of both detrimental
and protective pathways, a phenomenon previous-
ly described in the kainate model of epilepsy [43].
However, regional specificity was also evident here:
the Lcn2 gene was upregulated only in the dorsal
hippocampus (and remained unchanged in the cor-
tex), and PG prevented this increase. The S100a10
gene was upregulated in both structures, but with
different dynamics: in the hippocampus – in both
model groups (Pilo and Pilo+PG), whereas in the cor-
tex – only in the PG-treated group.
Thus, analysis of the expression of the astrogli-
al and microglial/macrophage markers revealed re-
gion-specific changes during the latent phase of the
lithium-pilocarpine model. The temporal cortex ex-
hibited a broader and more pronounced inflammato-
ry response than the dorsal hippocampus, including
activation of astrocytes (Gfap) and microglia (Aif1),
increase in the Nlrp3 expression, and decrease in
the Nos2 expression. A more profound decrease in
expression of the anti-inflammatory marker Arg1 was
observed in the hippocampus accompanied by the in-
crease in expression of the neurotoxic marker Lcn2.
PG did not block the main pathological changes
(glial activation, increased Il1b, decreased Arg1) but
exerted selective effects: it prevented the increase
in Lcn2 expression in the hippocampus, counteract-
ed the decrease in Nos2 expression, and induced in-
crease in the S100a10 expression in the cortex. This
indicates a region-dependent modulation of specific
glial pathways rather than systemic anti-inflammato-
ry effect of the drug during the latent phase.
Since epileptogenesis involves not only inflam-
matory but also regulatory systems, including neuro-
trophic factors that are under metabolic control [44],
we investigated expression of three growth factor
genes – Fgf 2, Bdnf, and Tgf b1. In the rats with the
lithium-pilocarpine model, we observed increased
expression of the Bdnf and Fgf2 genes in the dorsal
hippocampus, and of Tgf b1 in both the hippocampus
and the temporal cortex. It is known that the Bdnf
gene activity is increased in the temporal cortex of
the patients with epilepsy [45], and that the levels of
expression of the Bdnf and Fgf2 genes are upregulat-
ed in the hippocampus of the animals in the pilocar-
pine model [46, 47]. However, the increased expres-
sion of the growth factors studied may exert a dual
effect on epileptogenesis. For example, BDNF exerts
neuroprotective and cognition-enhancing effects via
the CREB activation [48] but also promotes mossy fi-
ber sprouting, a key mechanism in the development
of temporal lobe epilepsy [49]. FGF2 could prevent
neuronal death [50] but, at the same time, it could in-
duce ictal activity [51]. TGF-β1 plays a similarly dual
role, possessing anti-inflammatory properties [52]
while also contributing to seizure induction and as-
trogliosis [53].
In our study, PG influenced expression of the
neurotrophic factor genes only in the hippocampus: it
partially prevented the pilocarpine-induced increase
in the Fgf2 expression. At the same time, its effect on
the Tgfb1 and Bdnf expression was less pronounced
and did not reach statistical significance in the inter-
group comparisons. Previously, effect of rosiglitazone
on the Bdnf gene expression was demonstrated in a
similar model [54]. Greater sensitivity of the dorsal
hippocampus to PG may be explained by the higher
density of PPARγ in this brain region [55]. Signifi-
cance of the selective suppression of the Fgf2 gene in
the hippocampus for epileptogenesis requires further
investigation.
Given the key role of glutamate receptors in the
pathogenesis of epilepsy, we analyzed expression of
the genes encoding their major subunits in the lith-
ium-pilocarpine model and the effect of PG on their
expression. We found that expression of the Grin2a
and Grin2b genes, which encode the GluN2A and
GluN2B subunits of the NMDA receptors, was reduced
in the dorsal hippocampus of the experimental rats.
Data on the expression of the NMDA receptor subunit
genes in epilepsy models are contradictory, which is
likely explained by the differences in experimental
protocols and examination time points. For example,
the increased Grin2b expression was observed in the
chronic phase of the pilocarpine model without lith-
ium [56], whereas we previously observed decrease
in its expression during the latent phase of the lith-
ium-pilocarpine model [57]. We also found decrease
in the expression of the Gria2 gene (encoding the
GluA2 subunit of AMPA receptors) in both brain re-
gions examined, which is consistent with our previ-
ous data [58] and observations in other models of
epilepsy [59]. In the hippocampus, PG prevented the
EFFECT OF PIOGLITAZONE ON EPILEPTOGENESIS 811
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
epilepsy-associated downregulation in the Grin2b ex-
pression, restoring its level to values indistinguish-
able from the control. This result may reflect the
neuroprotective effect of PG demonstrated by other
authors in the lithium-pilocarpine model [60] and in
the pentylenetetrazole-induced seizure model [61].
This finding suggests that activation of PPARγ as a
metabolic sensor may stabilize transcriptional pro-
grams important for synaptic homeostasis. However,
precise molecular mechanisms underlying this effect
require further investigation.
Thus, this study demonstrated that the PPARγ
agonist PG attenuates behavioral disturbances and
selectively restores expression of the glutamate re-
ceptor subunit genes (Grin2b) and the neurotrophic
factor Fgf2 in the dorsal hippocampus during epi-
leptogenesis, while exerting only weak effect on the
glial markers and neuroinflammation. Since gluta-
mate receptors are expressed predominantly in neu-
rons, it is reasonable to assume that the neuropro-
tective potential of PG during epileptogenesis may
be primarily associated with modulation of neuronal
rather than glial processes. This highlights the prom-
ise of further investigation of PG within the frame-
work of strategies aimed at correcting disturbanc-
es related to neuronal metabolism and excitability
in epilepsy.
Abbreviations
Ctrl control group
PG pioglitazone
Pilo lithium-pilocarpine model of temporal
lobe epilepsy
PPAR peroxisome proliferator-activated
receptors
RT-qPCR real-time reverse transcription
polymerase chain reaction
SE status epilepticus
Supplementary information
The online version contains supplementary material
available at https://doi.org/10.1134/S0006297926600183.
Acknowledgments
The authors express their gratitude to Anna I.
Roginskaya for technical assistance with the experi-
ments.
Contributions
A.R.K. performed experiments, processed data,
prepared illustrations, and wrote and edited the
manuscript; O.E.Z. conceptualized the study, pro-
cessed data, and wrote and edited the manuscript;
D.S.S. performed experiments, conducted statisti-
cal analysis, and prepared illustrations; A.A.K. per-
formed experiments and edited the manuscript;
A.V.Z. conceptualized and supervised the study
and edited the manuscript. All authors have read
and agreed to the published version of the man-
uscript.
Funding
This work was financially supported by the state as-
signment for research project no. 075-00263-25-00.
Ethics approval and consent to participate
The study was conducted in accordance with the EU
Directive 2010/63/EU on the protection of animals
used for scientific purposes and was approved by
the Ethics Committee of the I. M. Sechenov Institute
of Evolutionary Physiology and Biochemistry, Russian
Academy of Sciences (Ethical Approval no. 1-16,
January 26, 2023).
Conflict of interest
The authors of this work declare that they have no
conflicts of interest.
REFERENCES
1. Sultana, B., Panzini, M.-A., Veilleux Carpentier, A., Comtois, J., Rioux, B., Gore, G., Bauer, P. R., Kwon, C.-S.,
Jetté, N., Josephson, C. B., and Keezer, M. R. (2021) Incidence and prevalence of drug-resistant epilepsy: a
systematic review and meta-analysis, Neurology, 96, 805-817, https://doi.org/10.1212/WNL.0000000000011839.
2. Becker, A. J. (2018) Review: Animal models of acquired epilepsy: insights into mechanisms of human epilep-
togenesis, Neuropathol. Appl. Neurobiol., 44, 112-129, https://doi.org/10.1111/nan.12451.
3. Rho, J. M., and Boison, D. (2022) The metabolic basis of epilepsy, Nat. Rev. Neurol., 18, 333-347, https://
doi.org/10.1038/s41582-022-00651-8.
4. Alyu, F., and Dikmen, M. (2017) Inflammatory aspects of epileptogenesis: contribution of molecular inflamma-
tory mechanisms, Acta Neuropsychiatr., 29, 1-16, https://doi.org/10.1017/neu.2016.47.
5. Boison, D., and Steinhäuser, C. (2018) Epilepsy and astrocyte energy metabolism, Glia, 66, 1235-1243, https://
doi.org/10.1002/glia.23247.
6. Villasana-Salazar, B., and Vezzani, A. (2023) Neuroinflammation microenvironment sharpens seizure circuit,
Neurobiol. Dis., 178, 106027, https://doi.org/10.1016/j.nbd.2023.106027.
7. Fan, Y. Y., and Huo, J. (2021) A1/A2 astrocytes in central nervous system injuries and diseases: angels or
devils? Neurochem. Int., 148, 105080, https://doi.org/10.1016/j.neuint.2021.105080.
KHARISOVA et al.812
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
8. Tang, Y., and Le, W. (2016) Differential roles of M1 and M2 microglia in neurodegenerative diseases, Mol.
Neurobiol., 53, 1181-1194, https://doi.org/10.1007/s12035-014-9070-5.
9. Blanquart, C., Barbier, O., Fruchart, J. C., Staels, B., and Glineur, C. (2003) Peroxisome proliferator-activated
receptors: regulation of transcriptional activities and roles in inflammation, J. Steroid Biochem. Mol. Biol., 85,
267-273, https://doi.org/10.1016/s0960-0760(03)00214-0.
10. Knowles, S., Budney, S., Deodhar, M., Matthews, S. A., Simeone, K. A., and Simeone, T. A. (2018) Ketogenic
diet regulates the antioxidant catalase via the transcription factor PPARγ2, Epilepsy Res., 147, 71-74, https://
doi.org/10.1016/j.eplepsyres.2018.09.009.
11. Adabi Mohazab, R., Javadi-Paydar, M., Delfan, B., and Dehpour, A. R. (2012) Possible involvement of PPAR-gam-
ma receptor and nitric oxide pathway in the anticonvulsant effect of acute pioglitazone on pentylenetetrazole-
induced seizures in mice, Epilepsy Res., 101, 28-35, https://doi.org/10.1016/j.eplepsyres.2012.02.015.
12. Abdelbasset, W. K., Jasim, S. A., Rudiansyah, M., Huldani, H., Margiana, R., Jalil, A. T., Mohammad, H. J.,
Ridha, H. S., and Yasin, G. (2022) Treatment of pilocarpine-induced epileptic seizures in adult male mice,
Braz. J. Biol., 84, e260091, https://doi.org/10.1590/1519-6984.260091.
13. Arteaga, O., Revuelta, M., Urigüen, L., Álvarez, A., Montalvo, H., and Hilario, E. (2015) Pretreatment with res-
veratrol prevents neuronal injury and cognitive deficits induced by perinatal hypoxia-ischemia in rats, PLoS
One, 10, e0142424, https://doi.org/10.1371/journal.pone.0142424.
14. Kaplan, J., Nowell, M., Chima, R., and Zingarelli, B. (2014) Pioglitazone reduces inflammation through inhibi-
tion of NF-κB in polymicrobial sepsis, Innate Immunity, 20, 519-528, https://doi.org/10.1177/1753425913501565.
15. Muzio, G., Barrera, G., and Pizzimenti, S. (2021) Peroxisome proliferator-activated receptors (PPARs) and
oxidative stress in physiological conditions and in cancer, Antioxidants (Basel), 10, 1734, https://doi.org/
10.3390/antiox10111734.
16. Salehi-Sadaghiani, M., Javadi-Paydar, M., Gharedaghi, M. H., Zandieh, A., Heydarpour, P., Yousefzadeh-
Fard, Y., and Dehpour, A. R. (2012) NMDA receptor involvement in antidepressant-like effect of pioglita-
zone in the forced swimming test in mice, Psychopharmacology, 223, 345-355, https://doi.org/10.1007/s00213-
012-2722-0.
17. Kovalenko, A. A., Zakharova, M. V., Zubareva, O. E., Schwarz, A. P., Skorik, Y. A., and Zaitsev, A. V. (2025)
Fenofibrate as a PPARα agonist modulates neuroinflammation and glutamate receptors in a rat model of tem-
poral lobe epilepsy: region-specific effects and behavioral outcomes, Int.J. Mol. Sci., 26, 9054, https://doi.org/
10.3390/ijms26189054.
18. Racine, R. J. (1972) Modification of seizure activity by electrical stimulation. II. Motor seizure, Electroenceph-
alogr. Clin. Neurophysiol., 32, 281-294, https://doi.org/10.1016/0013-4694(72)90177-0.
19. Dyomina, A. V., Zubareva, O. E., Smolensky, I. V., Vasilev, D. S., Zakharova, M. V., Kovalenko, A. A.,
Schwarz, A. P., Ischenko, A. M., and Zaitsev, A. V. (2020) Anakinra reduces epileptogenesis, provides neuro-
protection, and attenuates behavioral impairments in rats in the lithium-pilocarpine model of epilepsy, Phar-
maceuticals (Basel), 13, 340, https://doi.org/10.3390/ph13110340.
20. Hung, T.-Y., Chu, F.-L., Wu, D. C., Wu, S.-N., and Huang, C.-W. (2019) The protective role of peroxisome
proliferator-activated receptor-gamma in seizure and neuronal excitotoxicity, Mol. Neurobiol., 56, 5497-5506,
https://doi.org/10.1007/s12035-018-1457-2.
21. Wang, N., Mi, X., Gao, B., Gu, J., Wang, W., Zhang, Y., and Wang, X. (2015) Minocycline inhibits brain in-
flammation and attenuates spontaneous recurrent seizures following pilocarpine-induced status epilepticus,
Neuroscience, 287, 144-156, https://doi.org/10.1016/j.neuroscience.2014.12.021.
22. Shafaroodi, H., Moezi, L., Ghorbani, H., Zaeri, M., Hassanpour, S., Hassanipour, M., and Dehpour, A. R.
(2012) Sub-chronic treatment with pioglitazone exerts anti-convulsant effects in pentylenetetrazole-induced
seizures of mice: the role of nitric oxide, Brain Res. Bull., 87, 544-550, https://doi.org/10.1016/j.brainresbull.
2012.02.001.
23. Paxinos, G., and Watson, C. (2007) The Rat Brain Stereotaxic Co-Ordinates, Academic Press, https://doi.org/
10.1016/B978-0-12-547620-1.50006-0.
24. Zubareva, O. E., Dyomina, A. V., Kovalenko, A. A., Roginskaya, A. I., Melik-Kasumov, T. B., Korneeva, M. A.,
Chuprina, A. V., Zhabinskaya, A. A., Kolyhan, S. A., Zakharova, M. V., Gryaznova, M. O., and Zaitsev, A. V.
(2023) Beneficial effects of probiotic bifidobacterium longum in a lithium-pilocarpine model of temporal lobe
epilepsy in rats, Int. J. Mol. Sci., 24, 8451, https://doi.org/10.3390/ijms24098451.
25. Livak, K. J., and Schmittgen, T. D. (2001) Analysis of relative gene expression data using real-time quantitative
PCR and the 2
−ΔΔC
T
method, Methods, 25, 402-408, https://doi.org/10.1006/meth.2001.1262.
26. Smolensky, I. V., Zubareva, O. E., Kalemenev, S. V., Lavrentyeva, V. V., Dyomina, A. V., Karepanov, A. A.,
and Zaitsev, A. V. (2019) Impairments in cognitive functions and emotional and social behaviors in a rat
EFFECT OF PIOGLITAZONE ON EPILEPTOGENESIS 813
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
lithium-pilocarpine model of temporal lobe epilepsy, Behav. Brain Res., 372, 112044, https://doi.org/10.1016/j.bbr.
2019.112044.
27. Suleymanova, E. M., Gulyaev, M. V., and Abbasova, K. R. (2016) Structural alterations in the rat brain
and behavioral impairment after status epilepticus: an MRI study, Neuroscience, 315, 79-90, https://
doi.org/10.1016/j.neuroscience.2015.11.061.
28. Hussein, H. A., Moghimi, A., and Roohbakhsh, A. (2019) Anticonvulsant and ameliorative effects of pi-
oglitazone on cognitive deficits, inflammation and apoptosis in the hippocampus of rat pups ex-
posed to febrile seizure, Iran. J. Basic Med. Sci., 22, 267-276, https://doi.org/10.22038/ijbms.2019.
35056.8339.
29. Xu, Z., Xue, T., Zhang, Z., Wang, X., Xu, P., Zhang, J., Lei, X., Li, Y., Xie, Y., Wang, L., Fang, M., and Chen, Y.
(2011) Role of signal transducer and activator of transcription-3 in up-regulation of GFAP after epilepsy, Neu-
rochem. Res., 36, 2208-2215, https://doi.org/10.1007/s11064-011-0576-1.
30. Flores-Cuadrado, A., Saiz-Sanchez, D., Mohedano-Moriano, A., Lamas-Cenjor, E., Leon-Olmo, V., Martinez-
Marcos, A., and Ubeda-Bañon, I. (2021) Astrogliosis and sexually dimorphic neurodegeneration and mi-
crogliosis in the olfactory bulb in Parkinson’s disease, NPJ Parkinson’s Dis., 7, 11, https://doi.org/10.1038/
s41531-020-00154-7.
31. Mukherjee, S., Arisi, G. M., Mims, K., Hollingsworth, G., O’Neil, K., and Shapiro, L. A. (2020) Neuroinflam-
matory mechanisms of post-traumatic epilepsy, J. Neuroinflamm., 17, 193, https://doi.org/10.1186/s12974-020-
01854-w.
32. Zubareva, O. E., Kharisova, A. R., Roginskaya, A. I., Kovalenko, A. A., Zakharova, M. V., Schwarz, A. P., Sin-
yak, D. S., and Zaitsev, A. V. (2024) PPARbeta/delta agonist GW0742 modulates microglial and astroglial
gene expression in a rat model of temporal lobe epilepsy, Int. J. Mol. Sci., 25, 10015, https://doi.org/10.3390/
ijms251810015.
33. Sanz, P., Rubio, T., and Garcia-Gimeno, M. A. (2024) Neuroinflammation and epilepsy: from pathophysiology
to therapies based on repurposing drugs, Int. J. Mol. Sci., 25, 4161, https://doi.org/10.3390/ijms25084161.
34. San, Y.-Z., Liu, Y., Zhang, Y., Shi, P.-P., and Zhu, Y.-L. (2015) Peroxisome proliferator-activated receptor-γ ag-
onist inhibits the mammalian target of rapamycin signaling pathway and has a protective effect in a rat
model of status epilepticus, Mol. Med. Rep., 12, 1877-1883, https://doi.org/10.3892/mmr.2015.3641.
35. Sun, H., Huang, Y., Yu, X., Li, Y., Yang, J., Li, R., Deng, Y., and Zhao, G. (2008) Peroxisome proliferator-ac-
tivated receptor gamma agonist, rosiglitazone, suppresses CD40 expression and attenuates inflammato-
ry responses after lithium pilocarpine-induced status epilepticus in rats, Int.J. Dev. Neurosci., 26, 505-515,
https://doi.org/10.1016/j.ijdevneu.2008.01.009.
36. Dubbelaar, M. L., Kracht, L., Eggen, B. J. L., and Boddeke, E. W. G. M. (2018) The kaleidoscope of microglial
phenotypes, Front. Immunol., 9, 1753, https://doi.org/10.3389/fimmu.2018.01753.
37. Ding, Y., Wang, Y., Qi, M., Zhang, X., and Wu, D. (2025) Pioglitazone modulates microglia M1/M2 polariza-
tion through PPAR-γ pathway and exerts neuroprotective effects in experimental subarachnoid hemorrhage,
Mol. Neurobiol., 62, 5930-5946, https://doi.org/10.1007/s12035-024-04664-w.
38. Hong, S., Xin, Y., HaiQin, W., GuiLian, Z., Ru, Z., ShuQin, Z., HuQing, W., Li, Y., and Yun, D. (2012) The
PPARγ agonist rosiglitazone prevents cognitive impairment by inhibiting astrocyte activation and oxida-
tive stress following pilocarpine-induced status epilepticus, Neurol. Sci., 33, 559-566, https://doi.org/10.1007/
s10072-011-0774-2.
39. Ren, X., Li, Y.-F., Pei, T.-W., Wang, H.-S., Wang, Y.-H., and Chen, T. (2024) Rosiglitazone regulates astrocyte po-
larization and neuroinflammation in a PPAR-γ dependent manner after experimental traumatic brain injury,
Brain Res. Bull., 209, 110918, https://doi.org/10.1016/j.brainresbull.2024.110918.
40. Pohlentz, M. S., Müller, P., Cases-Cunillera, S., Opitz, T., Surges, R., Hamed, M., Vatter, H., Schoch, S., Becker,
A. J., and Pitsch, J. (2022) Characterisation of NLRP3 pathway-related neuroinflammation in temporal lobe
epilepsy, PLoS One, 17, e0271995, https://doi.org/10.1371/journal.pone.0271995.
41. Kharisova, A. R., Roginskaya, A. I., and Zubareva, O. E. (2024) Effect of cardarine on gene expression of
proteins involved in epileptogenesis in rat hippocampus in the lithium-pilocarpine model of temporal lobe
epilepsy, J. Evol. Biochem. Physiol., 60, 1064-1081, https://doi.org/10.1134/S0022093024030177.
42. Peng, J., Wang, K., Xiang, W., Li, Y., Hao, Y., and Guan, Y. (2019) Rosiglitazone polarizes microglia and
protects against pilocarpine-induced status epilepticus, CNS Neurosci. Ther., 25, 1363-1372, https://doi.org/
10.1111/cns.13265.
43. Dahal, A., Govindarajan, K., and Kar, S. (2023) Administration of kainic acid differentially alters astrocyte
markers and transiently enhanced phospho-tau level in adult rat hippocampus, Neuroscience, 516, 27-41,
https://doi.org/10.1016/j.neuroscience.2023.02.010.
KHARISOVA et al.814
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
44. Genzer, Y., Dadon, M., Burg, C., Chapnik, N., and Froy, O. (2016) Effect of dietary fat and the circadian clock
on the expression of brain-derived neurotrophic factor (BDNF), Mol. Cell Endocrinol., 430, 49-55, https://
doi.org/10.1016/j.mce.2016.04.015.
45. Martínez-Levy, G. A., Rocha, L., Rodríguez-Pineda, F., Alonso-Vanegas, M. A., Nani, A., Buentello-García, R. M.,
Briones-Velasco, M., San-Juan, D., Cienfuegos, J., and Cruz-Fuentes, C. S. (2018) Increased expression of
brain-derived neurotrophic factor transcripts I and VI, cAMP response element binding, and glucocorticoid
receptor in the cortex of patients with temporal lobe epilepsy, Mol. Neurobiol., 55, 3698-3708, https://doi.org/
10.1007/s12035-017-0597-0.
46. Schmidt-Kastner, R., Humpel, C., Wetmore, C., and Olson, L. (1996) Cellular hybridization for BDNF, trkB, and
NGF mRNAs and BDNF-immunoreactivity in rat forebrain after pilocarpine-induced status epilepticus, Exp.
Brain Res., 107, 331-347, https://doi.org/10.1007/BF00230416.
47. Hagihara, H., Hara, M., Tsunekawa, K., Nakagawa, Y., Sawada, M., and Nakano, K. (2005) Tonic-clonic sei-
zures induce division of neuronal progenitor cells with concomitant changes in expression of neurotrophic
factors in the brain of pilocarpine-treated mice, Brain Res. Mol. Brain Res., 139, 258-266, https://doi.org/
10.1016/j.molbrainres.2005.05.031.
48. Hashemi, P., and Ahmadi, S. (2023) Alpha-pinene moderates memory impairment induced by kainic acid via
improving the BDNF/TrkB/CREB signaling pathway in rat hippocampus, Front. Mol. Neurosci., 16, 1202232,
https://doi.org/10.3389/fnmol.2023.1202232.
49. Skupien-Jaroszek, A., Walczak, A., Czaban, I., Pels, K. K., Szczepankiewicz, A. A., Krawczyk, K., Ruszczycki, B.,
Wilczynski, G. M., Dzwonek, J., and Magalska, A. (2021) The interplay of seizures-induced axonal sprout-
ing and transcription-dependent Bdnf repositioning in the model of temporal lobe epilepsy, PLoS One, 16,
e0239111, https://doi.org/10.1371/journal.pone.0239111.
50. Liu, Z., D’Amore, P. A., Mikati, M., Gatt, A., and Holmes, G. L. (1993) Neuroprotective effect of chronic infu-
sion of basic fibroblast growth factor on seizure-associated hippocampal damage, Brain Res., 626, 335-338,
https://doi.org/10.1016/0006-8993(93)90598-h.
51. Liu, X., Liu, J., Liu, J., Liu, X.-L., Jin, L.-Y., Fan, W., Ding, J., Peng, L.-C., Wang, Y., and Wang, X. (2013)
BDNF-TrkB signaling pathway is involved in pentylenetetrazole-evoked progression of epileptiform activity in
hippocampal neurons in anesthetized rats, Neurosci. Bull., 29, 565-575, https://doi.org/10.1007/s12264-013-1326-y.
52. Xin, W., Pan, Y., Wei, W., Gerner, S. T., Huber, S., Juenemann, M., Butz, M., Bähr, M., Huttner, H. B.,
and Doeppner, T. R. (2023) TGF-β1 decreases microglia-mediated neuroinflammation and lipid droplet
accumulation in an in vitro stroke model, Int. J. Mol. Sci., 24, 17329, https://doi.org/10.3390/ijms242417329.
53. Zhang, Y., Zhang, M., Zhu, W., Pan, X., Wang, Q., Gao, X., Wang, C., Zhang, X., Liu, Y., Li, S., and Sun, H.
(2020) Role of elevated thrombospondin-1 in kainic acid-induced status epilepticus, Neurosci. Bull., 36, 263-276,
https://doi.org/10.1007/s12264-019-00437-x.
54. Hong, S., Xin, Y., HaiQin, W., GuiLian, Z., Ru, Z., ShuQin, Z., HuQing, W., Li, Y., Ning, B., and YongNan, L.
(2013) The PPARγ agonist rosiglitazone prevents neuronal loss and attenuates development of spontaneous
recurrent seizures through BDNF/TrkB signaling following pilocarpine-induced status epilepticus, Neurochem.
Int., 63, 405-412, https://doi.org/10.1016/j.neuint.2013.07.010.
55. Moreno, S., Farioli-Vecchioli, S., and Cerù, M. P. (2004) Immunolocalization of peroxisome proliferator-acti-
vated receptors and retinoid X receptors in the adult rat CNS, Neuroscience, 123, 131-145, https://doi.org/
10.1016/j.neuroscience.2003.08.064.
56. Müller, L., Tokay, T., Porath, K., Köhling, R., and Kirschstein, T. (2013) Enhanced NMDA receptor-depen-
dent LTP in the epileptic CA1 area via upregulation of NR2B, Neurobiol. Dis., 54, 183-193, https://doi.org/
10.1016/j.nbd.2012.12.011.
57. Zubareva, O. E., Kovalenko, A. A., Kalemenev, S. V., Schwarz, A. P., Karyakin, V. B., and Zaitsev, A. V. (2018)
Alterations in mRNA expression of glutamate receptor subunits and excitatory amino acid transporters follow-
ing pilocarpine-induced seizures in rats, Neurosci. Lett., 686, 94-100, https://doi.org/10.1016/j.neulet.2018.08.047.
58. Diespirov, G. P., Postnikova, T. Y., Griflyuk, A. V., Kovalenko, A. A., and Zaitsev, A. V. (2023) Alterations in the
properties of the rat hippocampus glutamatergic system in the lithium-pilocarpine model of temporal lobe
epilepsy, Biochemistry (Moscow), 88, 353-363, https://doi.org/10.1134/S0006297923030057.
59. Lippman-Bell, J. J., Zhou, C., Sun, H., and Feske, J. S. (2016) Early-life seizures alter synaptic calcium-per-
meable AMPA receptor function and plasticity, Mol. Cell. Neurosci., 76, 11-20, https://doi.org/10.1016/
j.mcn.2016.08.002.
60. Rostamian, S., Keshavarz Hedayati, S., Khosraviani, S., Aali, E., and Naderi, Y. (2021) Anticonvulsive and antioxi-
dant effects of pioglitazone on pilocarpine-induced seizures in mice, Iran. J. Toxicol., 15, 271-278, https://doi.org/
10.32598/ijt.15.4.833.1.
EFFECT OF PIOGLITAZONE ON EPILEPTOGENESIS 815
BIOCHEMISTRY (MOSCOW) Vol. 91 No. 5 2026
61. El-Megiri, N., Mostafa, Y. M., Ahmed, A., Mehanna, E. T., El-Azab, M. F., Alshehri, F., Alahdal, H., and El-Sayed,
N. M. (2022) Pioglitazone ameliorates hippocampal neurodegeneration, disturbances in glucose metabolism and
AKT/mTOR signaling pathways in pentyelenetetrazole-kindled mice, Pharmaceuticals (Basel), 15, 1113, https://
doi.org/10.3390/ph15091113.
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