1.Effect of electroacupuncture at the acupoints for Tiaozang Xingshen on cerebral metabolism in the patients with type 2 diabetes mellitus-associated cognitive dysfunction.
Lin YAO ; Yan-Ze LIU ; Meng-Yuan LI ; Zi-Yang ZHANG ; Shuo YU ; Shu-Nan SUN ; Ming XU ; Hai-Zhu ZHENG ; Shi-Qi MA ; Zhen ZHONG ; Hong-Feng WANG
Chinese Acupuncture & Moxibustion 2023;43(12):1343-1350
OBJECTIVES:
To investigate the cerebral metabolism in the patients with type 2 diabetes mellitus-associated cognitive dysfunction (T2DACD) and explore the mechanism of electroacupuncture (EA) at the acupoints for Tiaozang Xingshen (adjusting zangfu function and rescuing the spirit) in treatment of T2DACD, using magnetic resonance spectroscopy.
METHODS:
Fifteen patients with T2DACD (observation group) and 22 healthy subjects (control group) were enrolled. In the observation group, the patients were treated with EA for Tiaozang Xingshen at Baihui (GV 20) and Shenting (GV 24), and bilateral Feishu (BL 13), Pishu (BL 20), Shenshu (BL 23), Zusanli (ST 36), Sanyinjiao (SP 6), Hegu (LI 4) and Taichong (LR 3). EA was operated with disperse-dense wave, 2 Hz/100 Hz in frequency and 0.1 mA to 1.0 mA in current intensity; 30 min each time, once daily. One course of EA consisted of 5 treatments, at the interval of 2 days and the intervention lasted 8 courses. Before treatment in the control group, before and after treatment in the observation group, the score of Montreal cognitive assessment scale (MoCA), the score of clinical dementia rating (CDR), Flanker paradigm, Stroop paradigm, Nback paradigm, the score of self-rating anxiety scale (SAS), the score of self-rating depression scale (SDS), and the score of Hamilton depression rating scale (HAMD) were evaluated separately; the glycolipid metabolic indexes (fasting plasma glucose [FPG], glycosylated hemoglobin type A1c [HbA1c], total cholesterol [TC], triacylglycerol [TG], high-density lipoprotein cholesterol [HDL-C] and low-density lipoprotein cholesterol [LDL-C]) were determined;with the magnetic resonance spectroscopy technique adopted, the metabolites in the basal ganglia area were detected. The correlation analysis was performed for the metabolite values with MoCA score, CDR score , Flanker paradigm, Stroop paradigm, and Nback paradigm.
RESULTS:
Before treatment, compared with the control group, in the observation group, MoCA score was lower (P<0.001), CDR score and the levels of FPG and HbA1c were higher (P<0.001); the reaction times of Flanker non-conflict, Flanker conflict, Stroop neutrality, Stroop congruence, Stroop conflict, and 1-back were prolonged (P<0.05, P<0.001), and the accuracy of Flanker conflict, Stroop conflict, and 1-back decreased (P<0.05, P<0.01); the ratio of N-acetyl aspartate (NAA) to creatine (Cr) in the left basal ganglia area was dropped (P<0.001), and that of myo-inositol (MI) to Cr in the right side increased (P<0.05). In the observation group after treatment, compared with the levels before treatment, MoCA score was higher (P<0.001), the scores of CDR, SAS and HAMD were reduced (P<0.01, P<0.05), the reaction times of Flanker conflict and Stroop conflict shortened (P<0.001, P<0.05), and the accuracy of Flanker conflict and 1-back increased (P<0.001, P<0.05); the ratio of NAA to Cr in the left basal ganglia area and that of the gamma-aminobutyric acid (GABA) to Cr in the right increased (P<0.05), that of MI to Cr in the right decreased (P<0.05). Before treatment, in the observation group, the ratio of MI to Cr in the right basal ganglia area was positively correlated with the reaction time of Stroop congruence (r=0.671, P=0.012) and this ratio was positively correlated with the reaction time of Stroop conflict (r=0.576, P=0.039).
CONCLUSIONS
Electroacupuncture for "adjusting zangfu function and rescuing the mind" improves the cognitive function of T2DACD patients, which may be related to the regulation of NAA, MI and GABA levels in the basal ganglia.
Humans
;
Electroacupuncture
;
Acupuncture Therapy
;
Acupuncture Points
;
Diabetes Mellitus, Type 2/therapy*
;
Glycated Hemoglobin
;
Cognitive Dysfunction/therapy*
;
Cholesterol
;
gamma-Aminobutyric Acid
2.Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats.
Hong-Kun WANG ; Jin-Ming HE ; Yue-Heng YAN ; Zi-Hao WANG ; Ruo-Xuan LI ; Yan-Yan WANG
China Journal of Chinese Materia Medica 2023;48(20):5583-5591
This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.
Rats
;
Mice
;
Animals
;
Receptors, Ionotropic Glutamate/metabolism*
;
Hippocampus
;
Neuronal Plasticity
;
Receptors, N-Methyl-D-Aspartate/genetics*
;
Anxiety/genetics*
;
gamma-Aminobutyric Acid
3."Component-target-efficacy" network analysis and experimental verification of Qingkailing Oral Preparation.
Hong-Ying CHEN ; Peng-Fei YAO ; Yan-Qi HAN ; Xu XU ; Jun XU ; Bi-Yan PAN ; Dong-Sheng OUYANG ; Tie-Jun ZHANG
China Journal of Chinese Materia Medica 2023;48(1):170-182
This study aims to explore the mechanism of Qingkailing(QKL) Oral Preparation's heat-clearing, detoxifying, mind-tranquilizing effects based on "component-target-efficacy" network. To be specific, the potential targets of the 23 major components in QKL Oral Preparation were predicted by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP) and SwissTargetPrediction. The target genes were obtained based on UniProt. OmicsBean and STRING 10 were used for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the targets. Cytoscape 3.8.2 was employed for visualization and construction of "component-target-pathway-pharmacological effect-efficacy" network, followed by molecular docking between the 23 main active components and 15 key targets. Finally, the lipopolysaccharide(LPS)-induced RAW264.7 cells were adopted to verify the anti-inflammatory effect of six monomer components in QKL Oral Preparation. It was found that the 23 compounds affected 33 key signaling pathways through 236 related targets, such as arachidonic acid metabolism, tumor necrosis factor α(TNF-α) signaling pathway, inflammatory mediator regulation of TRP channels, cAMP signaling pathway, cGMP-PKG signaling pathway, Th17 cell differentiation, interleukin-17(IL-17) signaling pathway, neuroactive ligand-receptor intera-ction, calcium signaling pathway, and GABAergic synapse. They were involved in the anti-inflammation, immune regulation, antipyretic effect, and anti-convulsion of the prescription. The "component-target-pathway-pharmacological effect-efficacy" network of QKL Oral Preparation was constructed. Molecular docking showed that the main active components had high binding affinity to the key targets. In vitro cell experiment indicated that the six components in the prescription(hyodeoxycholic acid, baicalin, chlorogenic acid, isochlorogenic acid C, epigoitrin, geniposide) can reduce the expression of nitric oxide(NO), TNF-α, and interleukin-6(IL-6) in cell supernatant(P<0.05). Thus, the above six components may be the key pharmacodynamic substances of QKL Oral Preparation. The major components in QKL Oral Prescription, including hyodeoxycholic acid, baicalin, chlorogenic acid, isochlorogenic acid C, epigoitrin, geniposide, cholic acid, isochlorogenic acid A, and γ-aminobutyric acid, may interfere with multiple biological processes related to inflammation, immune regulation, fever, and convulsion by acting on the key protein targets such as IL-6, TNF, prostaglandin-endoperoxide synthase 2(PTGS2), arachidonate 5-lipoxygenase(ALOX5), vascular cell adhesion molecule 1(VCAM1), nitric oxide synthase 2(NOS2), prostaglandin E2 receptor EP2 subtype(PTGER2), gamma-aminobutyric acid receptor subunit alpha(GABRA), gamma-aminobutyric acid type B receptor subunit 1(GABBR1), and 4-aminobutyrate aminotransferase(ABAT). This study reveals the effective components and mechanism of QKL Oral Prescription.
Chlorogenic Acid
;
Drugs, Chinese Herbal/pharmacology*
;
gamma-Aminobutyric Acid
;
Interleukin-6
;
Medicine, Chinese Traditional
;
Molecular Docking Simulation
;
Tumor Necrosis Factor-alpha/genetics*
;
Animals
;
Mice
;
RAW 264.7 Cells
4.Anxiolytic and antidepressant effects of agarwood inhalation and its mechanism.
Bao GONG ; Can-Hong WANG ; Yu-Lan WU ; Yang-Yang LIU ; Jian-He WEI
China Journal of Chinese Materia Medica 2023;48(4):1023-1031
This study used m-chloropheniperazine(MCPP) and chronic unforeseeable mild stress(CUMS) to induce the rat models of anxiety and depression, respectively. The behaviors of rats were observed by the open field test(OFT), light-dark exploration test(LDE), tail suspension test(TST), and forced swimming test(FST), and the antidepressant and anxiolytic effects of agarwood essential oil(AEO), agarwood fragrant powder(AFP), and agarwood line incense(ALI) were explored. The enzyme-linked immunosorbent assay(ELISA) was used to determine the levels of 5-hydroxytryptamine(5-HT), glutamic acid(Glu), and γ-aminobutyric acid(GABA_A) in the hippocampal area. The Western blot assay was used to determine the protein expression levels of glutamate receptor 1(GluR1) and vesicular glutamate transporter type 1(VGluT1), exploring the anxiolytic and antidepressant mechanism of agarwood inhalation. The results showed that compared with the anxiety model group, the AEO, AFP, and ALI groups decreased the total distance(P<0.05), decreased the velocity of movements(P<0.05), prolonged the immobile time(P<0.05), and reduced the distance and velocity of the rat model of anxiety in the dark box(P<0.05). Compared with the depression model group, the AEO, AFP, and ALI groups increased the total distance and average velocity(P<0.05), reduced the immobile time(P<0.05), and reduced the forced swimming and tail suspension time(P<0.05). In terms of transmitter regulation, the AEO, AFP, and ALI groups decreased the level of Glu in the rat model of anxiety(P<0.05) and increased the levels of GABA_A and 5-HT(P<0.05), while the AEO, AFP, and ALI groups all increased the level of 5-HT in the rat model of depression(P<0.05) and decreased the levels of GABA_A and Glu(P<0.05). At the same time, the AEO, AFP, and ALI groups all increased the protein expression levels of GluR1 and VGluT1 in the hippocampus of the rat models of anxiety and depression(P<0.05). In conclusion, AEO, AFP, and ALI exert anxiolytic and antidepressant effects, and the mechanism might be related to the regulation of the neurotransmitter and the protein expression of GluR1 and VGluT1 in the hippocampus.
Animals
;
Rats
;
Anti-Anxiety Agents
;
Serotonin
;
alpha-Fetoproteins
;
Antidepressive Agents
;
Glutamic Acid
;
gamma-Aminobutyric Acid
5.Efficient biosynthesis of γ-aminobutyric acid by rationally engineering the catalytic pH range of a glutamate decarboxylase from Lactobacillus plantarum.
Jiewen XIAO ; Jin HAN ; Zhina QIAO ; Guodong ZHANG ; Wujun HUANG ; Kai QIAN ; Meijuan XU ; Xian ZHANG ; Taowei YANG ; Zhiming RAO
Chinese Journal of Biotechnology 2023;39(6):2108-2125
γ-aminobutyric acid can be produced by a one-step enzymatic reaction catalyzed by glutamic acid decarboxylase. The reaction system is simple and environmentally friendly. However, the majority of GAD enzymes catalyze the reaction under acidic pH at a relatively narrow range. Thus, inorganic salts are usually needed to maintain the optimal catalytic environment, which adds additional components to the reaction system. In addition, the pH of solution will gradually rise along with the production of γ-aminobutyric acid, which is not conducive for GAD to function continuously. In this study, we cloned the glutamate decarboxylase LpGAD from a Lactobacillus plantarum capable of efficiently producing γ-aminobutyric acid, and rationally engineered the catalytic pH range of LpGAD based on surface charge. A triple point mutant LpGADS24R/D88R/Y309K was obtained from different combinations of 9 point mutations. The enzyme activity at pH 6.0 was 1.68 times of that of the wild type, suggesting the catalytic pH range of the mutant was widened, and the possible mechanism underpinning this increase was discussed through kinetic simulation. Furthermore, we overexpressed the Lpgad and LpgadS24R/D88R/Y309K genes in Corynebacterium glutamicum E01 and optimized the transformation conditions. An optimized whole cell transformation process was conducted under 40 ℃, cell mass (OD600) 20, 100 g/L l-glutamic acid substrate and 100 μmol/L pyridoxal 5-phosphate. The γ-aminobutyric acid titer of the recombinant strain reached 402.8 g/L in a fed-batch reaction carried out in a 5 L fermenter without adjusting pH, which was 1.63 times higher than that of the control. This study expanded the catalytic pH range of and increased the enzyme activity of LpGAD. The improved production efficiency of γ-aminobutyric acid may facilitate its large-scale production.
Glutamate Decarboxylase/genetics*
;
Lactobacillus plantarum/genetics*
;
Catalysis
;
gamma-Aminobutyric Acid
;
Hydrogen-Ion Concentration
;
Glutamic Acid
6.Effect of acupuncture combined with low frequency rTMS on comorbid mild-to-moderate depressive disorder and insomnia: a randomized controlled trial.
Lu-da YAN ; Peng ZHOU ; Mei-Qi LAI ; Miao WU ; Yu ZHANG ; Run-Dong TANG ; Rui SUN ; Yi LUO ; Mei LI ; Ji-Ling SUN ; Wen-Bin FU
Chinese Acupuncture & Moxibustion 2023;43(4):374-378
OBJECTIVE:
To observe the impacts of acupuncture on depressive mood and sleep quality in patients with comorbid mild-to-moderate depressive disorder and insomnia, and explore its effect mechanism.
METHODS:
A total of 60 patients with comorbid mild-to-moderate depressive disorder and insomnia were randomly divided into an observation group (30 cases, 1 case dropped off) and a control group (30 cases, 2 cases dropped off). In the observation group, acupuncture and low frequency repeated transcranial magnetic stimulation (rTMS) were combined for the intervention. Acupuncture was applied to Baihui (GV 20), Yintang (GV 24+), Neiguan (PC 6) and Yanglingquan (GB 34), etc., the needles were retained for 30 min; and the intradermal needles were embedded at Xinshu (BL 15) and Danshu (BL 19) for 2 days. After acupuncture, the rTMS was delivered at the right dorsolateral prefrontal cortex (R-DLPFC), with 1 Hz and 80% of movement threshold, lasting 30 min in each treatment. In the control group, the sham-acupuncture was adopted, combined with low frequency rTMS. The acupoint selection and manipulation were the same as the observation group. In the two groups, acupuncture was given once every two days, 3 times weekly; while, rTMS was operated once daily, for consecutive 5 days a week. The duration of treatment consisted of 4 weeks. Hamilton depression scale-17 (HAMD-17) and Pittsburgh sleep quality index (PSQI) scores were observed before and after treatment, as well as 1 month after the treatment completion (follow-up period) separately. Besides, the levels of nerve growth factor (BDNF) and γ-aminobutyric acid (GABA) in the serum were detected before and after treatment in the two groups.
RESULTS:
After treatment and in follow-up, the HAMD-17 scores were lower than those before treatment in the two groups (P<0.05), and the scores in the observation group were lower than the control group (P<0.05). After treatment, the total scores and the scores of each factor of PSQI were reduced in the two groups in comparison with those before treatment except for the score of sleep efficiency in the control group (P<0.05); the total PSQI score and the scores for sleep quality, sleep latency, sleep efficiency and daytime dysfunction in the observation group were all lower than those in the control group (P<0.05). In the follow-up, except for the scores of sleep duration and sleep efficiency in the control group, the total PSQI score and the scores of all the other factors were reduced compared with those before treatment in the two groups (P<0.05); the total PSQI score and the scores of sleep quality, sleep latency, sleep duration, sleep efficiency and daytime dysfunction in the observation group were lower than the control group (P<0.05). After treatment, the levels of serum BDNF and GABA were increased in comparison with those before treatment in the observation group (P<0.05), and the level of serum BDNF was higher than that in the control group (P<0.05).
CONCLUSION
Acupuncture relieves depressive mood and improves sleep quality in patients with comorbid mild-to-moderate depressive disorder and insomnia. The effect mechanism may be related to the regulation of BDNF and GABA levels and the promotion of brain neurological function recovery.
Humans
;
Sleep Initiation and Maintenance Disorders/therapy*
;
Transcranial Magnetic Stimulation
;
Brain-Derived Neurotrophic Factor
;
Treatment Outcome
;
Acupuncture Therapy
;
Acupuncture Points
;
gamma-Aminobutyric Acid
;
Depressive Disorder
7.Effect of Auricular Acupoint Bloodletting plus Auricular Acupressure on Sleep Quality and Neuroendocrine Level in College Students with Primary Insomnia: A Randomized Controlled Trial.
Hao CHEN ; Ming-Jian ZHANG ; Jia-Ai WU ; Yan-Fen SHE ; Xin-Ru YUAN ; Yun-Xiang HUO ; Huan SUN ; Dao-Nan LIU ; Xu-Liang SHI
Chinese journal of integrative medicine 2022;28(12):1096-1104
OBJECTIVE:
To evaluate the effects of auricular acupoint bloodletting (AB) and auricular acupressure (AA) on sleep quality and the levels of melatonin (MT), glutamic acid (Glu), and γ -aminobutyric acid (GABA) in college students with primary insomnia, and to explore the possible mechanism.
METHODS:
Totally 74 college students at Hebei University of Chinese Medicine with primary insomnia were selected from October 2019 to October 2020. All patients were assigned to AB+AA group (37 cases, received combination of AB and AA) and AA group (37 cases, received only AA on the same acupoints) by a random number table. Each group was treated twice a week for 4 weeks. The Pittsburgh Sleep Quality Index (PSQI) score, Chinese medicine (CM) syndrome score, total effective rate, serum concentrations of MT, Glu, and GABA, and Glu/GABA ratio were compared between the two groups after treatment and at follow-up. The safety of therapy was also evaluated.
RESULTS:
After 4-week treatment, the total scores of PSQI, each PSQI component score, and the CM syndrome scores in both groups all decreased (P<0.05); the serum MT concentrations in both groups all increased (P<0.05). The concentrations of Glu and GABA in the AB+AA group were significantly higher than those in the AA group after treatment (P<0.05). However, there was no significant difference in the ratio of Glu/GABA in both groups before and after treatment (P>0.05). At follow-up, the CM syndrome score in the AB+AA group was significantly lower than that in the AA group (P<0.05). There was no significant difference between the two groups in total effective rates and adverse events (P>0.05).
CONCLUSIONS
Both AB+AA and AA can relieve insomnia symptoms, but a stronger long-term effect were observed for AB+AA. AB+AA can promote the secretion of MT, increase the levels of Glu and GABA more effective than AA, and regulate their imbalance, and thus it may be benificial for treating insomnia.
Humans
;
Acupressure
;
Acupuncture Points
;
Bloodletting
;
Sleep Initiation and Maintenance Disorders/therapy*
;
Sleep Quality
;
Syndrome
;
Students
;
gamma-Aminobutyric Acid
8.Effect of
Wen-Zhong WU ; Shi-Yu ZHENG ; Cheng-Yong LIU ; Shan QIN ; Xiao-Qiu WANG ; Jin-Li HU ; Qing-Yun WAN ; Ya-Nan ZHAO ; Han-Qing XI
Chinese Acupuncture & Moxibustion 2021;41(7):721-724
9.Na-K-2Cl symporter contributes to γ-aminobutyric acid-evoked excitation in rat enteric neurons.
Sumei LIU ; Lifei ZHENG ; Kayla NEITZEL ; Tuo JI ; Wei REN ; Mei-Hua QU
Acta Physiologica Sinica 2020;72(3):263-273
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the adult central nervous system (CNS), however, it causes excitation in the immature CNS neurons. The shift from GABA-induced depolarization to hyperpolarization in postnatal brain is primarily due to progressive decrease in the expression of the Na-K-2Cl symporter 1 (NKCC1) and increased expression of the K-Cl cotransporter 2 (KCC2). Unlike CNS neurons, both immature and mature neurons in the enteric nervous system (ENS) are depolarized by GABA. Molecular mechanisms by which GABA excites ENS neurons are unclear. It is understood, however, that the excitatory action depends on elevated intraneuronal Cl. We aimed to test a hypothesis that high intracellular Cl in ENS neurons is maintained by activity of the NKCCs. We found that NKCC2 immunoreactivity (IR) was expressed in the ENS of the rat colon on postnatal day 1 (P1). The expression level of NKCC2 continuously increased and reached a steady high level on P14 and maintained at that level in adulthood. NKCC1 IR appeared in ENS on P14 and maintained through adulthood. KCC2 IR was not detectable in the ENS in any of the developmental stages. Both NKCC1 IR and NKCC2 IR were co-expressed with GABA receptors in ENS neurons. Exogenous GABA (1 mmol/L) caused membrane depolarization in the ENS neurons. The reversal potential of GABA-induced depolarization was about -16 mV. Blockade of NKCC by bumetanide (50 μmol/L) or furosemide (300 μmol/L) suppressed the depolarizing responses to GABA. Bumetanide (50 μmol/L) shifted the reversal potential of GABA-induced depolarization in the hyperpolarizing direction. Neither the KCC blocker DIOA (20 μmol/L) nor the Cl/HCO exchanger inhibitor DIDS (200 μmol/L) suppressed GABA-evoked depolarization. The results suggest that ENS neurons continuously express NKCC2 since P1 and NKCC1 since P14, which contribute to the accumulation of Cl in ENS neurons and GABA-evoked depolarization in neonate and adult ENS neurons. These results provide the first direct evidence for the contribution of both NKCC2 and NKCC1 to the GABA-mediated depolarization.
Animals
;
Bumetanide
;
Neurons
;
Rats
;
Receptors, GABA-A
;
Symporters
;
gamma-Aminobutyric Acid
10.Calpain-2 as a Treatment Target in Prenatal Stress-induced Epileptic Spasms in Infant Rats
Hyeok Hee KWON ; Chiranjivi NEUPANE ; Juhee SHIN ; Do Hyeong GWON ; Yuhua YIN ; Nara SHIN ; Hyo Jung SHIN ; Jinpyo HONG ; Jin Bong PARK ; YoonYoung YI ; Dong Woon KIM ; Joon Won KANG
Experimental Neurobiology 2019;28(4):529-536
Stress can induce a serious epileptic encephalopathy that occurs during early infancy. Recent studies have revealed that prenatal stress exposure is a risk factor for the development of infantile spasms. Our previous work demonstrates that prenatal stress with betamethasone-induced alterations to the expression of the K⁺/Cl⁻ co-transporter (KCC2) in gamma-aminobutyric acid (GABA) interneurons lowers the seizure threshold in exposed animals. Here, we further investigated the mechanisms involved in this KCC2 dysfunction and explored possible treatment options. We stressed Sprague-Dawley rats prenatally and further treated dams with betamethasone on gestational day 15, which increases seizure susceptibility and NMDA (N-Methyl-D-aspartate)-triggered spasms on postnatal day 15. In this animal model, first, we evaluated baseline calpain activity. Second, we examined the cleavage and dephosphorylation of KCC2. Finally, we checked the effect of a calpain inhibitor on seizure occurrence. The phosphorylated-N-methyl-D-aspartate Receptor 2B (NR2B):non-phosphorylated NR2B ratio was found to be higher in the cortex of the prenatally stressed beta-methasone model. We further found that the betamethasone model exhibited increased phosphorylation of calpain-2 and decreased phosphorylation of KCC2 and Glutamic acid decarboxylase 67 (GAD67). After using a calpain inhibitor in prenatal-stress rats, the seizure frequency decreased, while latency increased. GABAergic depolarization was further normalized in prenatal-stress rats treated with the calpain inhibitor. Our study suggests that calpain-dependent cleavage and dephosphorylation of KCC2 decreased the seizure threshold of rats under prenatal stress. Calpain-2 functions might, thus, be targeted in the future for the development of treatments for epileptic spasms.
Animals
;
Betamethasone
;
Brain Diseases
;
Calpain
;
Epilepsy
;
gamma-Aminobutyric Acid
;
Glutamate Decarboxylase
;
Humans
;
Infant
;
Infant, Newborn
;
Interneurons
;
Models, Animal
;
N-Methylaspartate
;
Phosphorylation
;
Rats
;
Rats, Sprague-Dawley
;
Risk Factors
;
Seizures
;
Spasm
;
Spasms, Infantile

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