1.Impact of Social Defeat Stress on DNA Methylation in Drd2, Nr3c1, and Stmn1 in Wild-type and Stmn1 Knock-out Mice
Young-Eun OH ; Thong Ba NGUYEN ; Fatima Zahra RAMI ; Maryam KARAMIKHEIRABAD ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2022;20(1):51-60
Objective:
Epigenetic profiles can be modified by stress. Dopamine receptor D2 (Drd2), glucocorticoid receptor gene (Nr3c1) and Stathmin 1 (Stmn1) genes are all implicated in adaptation to stress. The aim of study is to investigate impact of social defeat on DNA methylation in Drd2, Nr3c1, and Stmn1 in wild-type (WT) and Stmn1 knock-out (KO) mice.
Methods:
The WT and Stmn1 KO mice were subjected to chronic social defeat. Brain tissues of the prefrontal cortex (PFC), amygdala (AMY) and hippocampus (HIP) were obtained. We measured DNA methylation levels of the Drd2, Nr3c1, and Stmn1 genes in the PFC, AMY, and HIP using pyrosequencing.
Results:
In WT mice, social defeat stress did not induce any changes in Drd2 methylation, whereas significant hypermethylation occurred in Nr3c1 and Stmn1 in the susceptible and unsusceptible groups, respectively, compared to the control group. The methylation responses in the Stmn1 KO mice differed from those seen in the WT mice, such that hypermethylation was evident in all three genes in the susceptible and unsusceptible groups compared to control group. Comparison of the Stmn1 KO and WT mice revealed the same pattern of hypermethylation for all three genes.
Conclusion
Social defeat stress induced different epigenetic modifications in three genes among control, unsusceptible, and susceptible groups of WT and Stmn1 KO mice. In particular, hypermethylation of Nr3c1 in the HIP of the susceptible group, and of Stmn1 in the AMY of the unsusceptible group in WT mice, could serve as epigenetic biomarkers of stress susceptibility and stress resilience, respectively.
2.Risperidone Induced DNA Methylation Changes in Dopamine Receptor and Stathmin Genes in Mice Exposed to Social Defeat Stress
Fatima Zahra RAMI ; Thong Ba NGUYEN ; Young-Eun OH ; Maryam KARAMIKHEIRABAD ; Thi-Hung LE ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2022;20(2):373-388
Objective:
Understanding complex epigenetic mechanisms is necessary to fully elucidate the effects of antipsychotic drug. This study investigated DNA methylation and mRNA expression levels of dopamine D2 and D1 receptor (Drd2 and Drd1, respectively), nuclear receptor subfamily 3, group C, member 1 (Nr3c1) and stathmin 1 (Stmn1) in brain regions of mice exposed to social defeat stress (SDS) and effects of risperidone on altered methylation and mRNA expression levels induced by SDS.
Methods:
Following SDS for 10 days, risperidone (0.2 mg/kg) or vehicle was administered to adult mice for 7 days. Brain tissues from the prefrontal cortex (PFC), hippocampus (HIP) and amygdala (AMY) were processed to measure methylation and mRNA levels of Drd2, Drd1, Nr3c1 and Stmn1 using pyrosequencing and real time-polymerase chain reaction.
Results:
We found altered methylation status of Nr3c1 and Stmn1 in the HIP and AMY of mice exposed to SDS. These changes were reversed by risperidone treatment. In addition, different methylation patterns of Drd2 and Drd1 in the PFC and AMY between defeated and control mice were identified with risperidone treatment.
Conclusion
These findings suggest that risperidone can cause epigenetic changes in Drd2, Drd1, Nr3c1 and Stmn1 in defeated mice. These changes could be epigenetic mechanisms underlying antipsychotic efficacy.
3.Effects of Epothilone D on Social Defeat Stress-induced Changes in Microtubule-related and Endoplasmic Reticulum Stress Protein Expression
Thi-Hung LE ; Ling LI ; Fatima Zahra RAMI ; Jung-Mi OH ; Sungkun CHUN ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2025;23(1):110-119
Objective:
Epothilone D (EpoD), microtubule (MT) stabilizing agent, demonstrated promising results in the animal models of Alzheimer’s disease, Parkinson’s disease and schizophrenia. The present study sought to investigate preventive effects of EpoD on altered changes of MT related proteins and endoplasmic reticulum (ER) stress proteins induced by social defeat stress (SDS).
Methods:
We measured protein expression levels of -tubulin and its post-translational modifications, MT-associated protein 2, stathmin1 and 2 with their phosphorylated forms, and ER stress markers, 78-kDa glucose-regulated protein (GRP-78) and CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) in the prefrontal cortex (PFC) and hippocampus (HIP) of C57BL/6J strain mice treated with EpoD (2 mg/kg) or its vehicle, dimethylsulfoxide (DMSO), and exposed to SDS.
Results:
We observed lower levels of acetylated -tubulin, MAP2, p-STMN (Ser16), and GRP-78 in the PFC of the EpoD-Con group when compared to the DMSO-Con group. On the other hand, in the HIP, there were significantly higher levels of tyrosinated -tubulin and GRP-78 in the EpoD-Defeat group compared to the DMSO-Defeat group.Furthermore, the level of MAP2 in the HIP was found to be lower in the EpoD-Con group compared to the DMSO-Con group.
Conclusion
Our results suggest that EpoD exhibits a dual impact, manifesting both beneficial and detrimental effects on the aberrant changes of MT-related proteins and ER stress proteins induced by SDS, depending on the brain regions.These findings underscore the complexity of EpoD’s effects, necessitating further exploration to understand its intricate mechanisms in cellular pathways linked to SDS.
4.Effects of Epothilone D on Social Defeat Stress-induced Changes in Microtubule-related and Endoplasmic Reticulum Stress Protein Expression
Thi-Hung LE ; Ling LI ; Fatima Zahra RAMI ; Jung-Mi OH ; Sungkun CHUN ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2025;23(1):110-119
Objective:
Epothilone D (EpoD), microtubule (MT) stabilizing agent, demonstrated promising results in the animal models of Alzheimer’s disease, Parkinson’s disease and schizophrenia. The present study sought to investigate preventive effects of EpoD on altered changes of MT related proteins and endoplasmic reticulum (ER) stress proteins induced by social defeat stress (SDS).
Methods:
We measured protein expression levels of -tubulin and its post-translational modifications, MT-associated protein 2, stathmin1 and 2 with their phosphorylated forms, and ER stress markers, 78-kDa glucose-regulated protein (GRP-78) and CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) in the prefrontal cortex (PFC) and hippocampus (HIP) of C57BL/6J strain mice treated with EpoD (2 mg/kg) or its vehicle, dimethylsulfoxide (DMSO), and exposed to SDS.
Results:
We observed lower levels of acetylated -tubulin, MAP2, p-STMN (Ser16), and GRP-78 in the PFC of the EpoD-Con group when compared to the DMSO-Con group. On the other hand, in the HIP, there were significantly higher levels of tyrosinated -tubulin and GRP-78 in the EpoD-Defeat group compared to the DMSO-Defeat group.Furthermore, the level of MAP2 in the HIP was found to be lower in the EpoD-Con group compared to the DMSO-Con group.
Conclusion
Our results suggest that EpoD exhibits a dual impact, manifesting both beneficial and detrimental effects on the aberrant changes of MT-related proteins and ER stress proteins induced by SDS, depending on the brain regions.These findings underscore the complexity of EpoD’s effects, necessitating further exploration to understand its intricate mechanisms in cellular pathways linked to SDS.
5.Effects of Epothilone D on Social Defeat Stress-induced Changes in Microtubule-related and Endoplasmic Reticulum Stress Protein Expression
Thi-Hung LE ; Ling LI ; Fatima Zahra RAMI ; Jung-Mi OH ; Sungkun CHUN ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2025;23(1):110-119
Objective:
Epothilone D (EpoD), microtubule (MT) stabilizing agent, demonstrated promising results in the animal models of Alzheimer’s disease, Parkinson’s disease and schizophrenia. The present study sought to investigate preventive effects of EpoD on altered changes of MT related proteins and endoplasmic reticulum (ER) stress proteins induced by social defeat stress (SDS).
Methods:
We measured protein expression levels of -tubulin and its post-translational modifications, MT-associated protein 2, stathmin1 and 2 with their phosphorylated forms, and ER stress markers, 78-kDa glucose-regulated protein (GRP-78) and CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) in the prefrontal cortex (PFC) and hippocampus (HIP) of C57BL/6J strain mice treated with EpoD (2 mg/kg) or its vehicle, dimethylsulfoxide (DMSO), and exposed to SDS.
Results:
We observed lower levels of acetylated -tubulin, MAP2, p-STMN (Ser16), and GRP-78 in the PFC of the EpoD-Con group when compared to the DMSO-Con group. On the other hand, in the HIP, there were significantly higher levels of tyrosinated -tubulin and GRP-78 in the EpoD-Defeat group compared to the DMSO-Defeat group.Furthermore, the level of MAP2 in the HIP was found to be lower in the EpoD-Con group compared to the DMSO-Con group.
Conclusion
Our results suggest that EpoD exhibits a dual impact, manifesting both beneficial and detrimental effects on the aberrant changes of MT-related proteins and ER stress proteins induced by SDS, depending on the brain regions.These findings underscore the complexity of EpoD’s effects, necessitating further exploration to understand its intricate mechanisms in cellular pathways linked to SDS.
6.Effects of Epothilone D on Social Defeat Stress-induced Changes in Microtubule-related and Endoplasmic Reticulum Stress Protein Expression
Thi-Hung LE ; Ling LI ; Fatima Zahra RAMI ; Jung-Mi OH ; Sungkun CHUN ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2025;23(1):110-119
Objective:
Epothilone D (EpoD), microtubule (MT) stabilizing agent, demonstrated promising results in the animal models of Alzheimer’s disease, Parkinson’s disease and schizophrenia. The present study sought to investigate preventive effects of EpoD on altered changes of MT related proteins and endoplasmic reticulum (ER) stress proteins induced by social defeat stress (SDS).
Methods:
We measured protein expression levels of -tubulin and its post-translational modifications, MT-associated protein 2, stathmin1 and 2 with their phosphorylated forms, and ER stress markers, 78-kDa glucose-regulated protein (GRP-78) and CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) in the prefrontal cortex (PFC) and hippocampus (HIP) of C57BL/6J strain mice treated with EpoD (2 mg/kg) or its vehicle, dimethylsulfoxide (DMSO), and exposed to SDS.
Results:
We observed lower levels of acetylated -tubulin, MAP2, p-STMN (Ser16), and GRP-78 in the PFC of the EpoD-Con group when compared to the DMSO-Con group. On the other hand, in the HIP, there were significantly higher levels of tyrosinated -tubulin and GRP-78 in the EpoD-Defeat group compared to the DMSO-Defeat group.Furthermore, the level of MAP2 in the HIP was found to be lower in the EpoD-Con group compared to the DMSO-Con group.
Conclusion
Our results suggest that EpoD exhibits a dual impact, manifesting both beneficial and detrimental effects on the aberrant changes of MT-related proteins and ER stress proteins induced by SDS, depending on the brain regions.These findings underscore the complexity of EpoD’s effects, necessitating further exploration to understand its intricate mechanisms in cellular pathways linked to SDS.
7.Effects of Social Defeat Stress on Microtubule Regulating Proteins and Tubulin Polymerization
Thi-Hung LE ; Jung-Mi OH ; Fatima Zahra RAMI ; Ling LI ; Sung-Kun CHUN ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2024;22(1):129-138
Objective:
Microtubule (MT) stability in neurons is vital for brain development; instability is associated with neuropsychiatric disorders. The present study examined the effects of social defeat stress (SDS) on MT-regulating proteins and tubulin polymerization.
Methods:
After 10 days of SDS, defeated mice were separated into susceptible (Sus) and unsusceptible (Uns) groups based on their performance in a social avoidance test. Using extracted brain tissues, we measured the expression levels of α-tubulin, acetylated α-tubulin, tyrosinated α-tubulin, MT-associated protein-2 (MAP2), stathmin (STMN1), phospho stathmin serine 16 (p-STMN1 [Ser16]), phospho stathmin serine 25 (p-STMN1 [Ser25]), phospho stathmin serine 38 (p-STMN1 [Ser38]), stathmin2 (STMN2), phospho stathmin 2 serine 73 (p-STMN2 [Ser73]), 78-kDa glucose-regulated protein (GRP-78), and CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) using Western blot assay. The tubulin polymerization rate was also measured.
Results:
We observed increased and decreased expression of acetylated and tyrosinated α-tubulin, respectively, decreased expression of p-STMN1 (Ser16) and increased expression of p-STMN1 (Ser25), p-STMN2 (Ser73) and GRP-78 and CHOP in the prefrontal cortex and/or hippocampus of defeated mice. A reduced tubulin polymerization rate was observed in the Sus group compared to the Uns and Con groups.
Conclusion
Our findings suggest that SDS has detrimental effects on MT stability, and a lower tubulin polymerization rate could be a molecular marker for susceptibility to SDS.
8.Methylome-wide Association Study of Patients with Recent-onset Psychosis
Yan-Hong PIAO ; Yin CUI ; Fatima Zahra RAMI ; Ling LI ; Maryam KARAMIKHEIRABAD ; Shi Hyun KANG ; Sung-Wan KIM ; Jung Jin KIM ; Bong Ju LEE ; Young-Chul CHUNG
Clinical Psychopharmacology and Neuroscience 2022;20(3):462-473
Objective:
Dysregulation of gene expression through epigenetic mechanisms may have a vital role in the pathogenesis of schizophrenia (SZ). In this study, we investigated the association of altered methylation patterns with SZ symptoms and early trauma in patients and healthy controls.
Methods:
The present study was conducted to identify methylation changes in CpG sites in peripheral blood associated with recent-onset (RO) psychosis using methylome-wide analysis. Lifestyle factors, such as smoking, alcohol, exercise, and diet, were controlled.
Results:
We identified 2,912 differentially methylated CpG sites in patients with RO psychosis compared to controls. Most of the genes associated with the top 20 differentially methylated sites had not been reported in previous methylation studies and were involved in apoptosis, autophagy, axonal growth, neuroinflammation, protein folding, etc. The top 15 significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways included the oxytocin signaling pathway, long-term depression pathway, axon guidance, endometrial cancer, long-term potentiation, mitogen-activated protein kinase signaling pathway, and glutamatergic pathway, among others. In the patient group, significant associations of novel methylated genes with early trauma and psychopathology were observed.
Conclusion
Our results suggest an association of differential DNA methylation with the pathophysiology of psychosis and early trauma. Blood DNA methylation signatures show promise as biomarkers of future psychosis.
9.Effects of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Criteria Changes for Schizophrenia on Diagnoses of First-Episode Schizophrenia Spectrum Disorders
WooRi CHO ; Sung-Wan KIM ; Seung-Hee WON ; Bong-Ju LEE ; Naohisa TSUJINO ; Youji TAKUBO ; Taiju YAMAGUCHI ; Takahiro NEMOTO ; Ling LI ; Thi-Hung LE ; Fatima Zahra RAMI ; Young-Chul CHUNG
Psychiatry Investigation 2025;22(2):212-217
Objective:
Impact of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) changes on the criteria for schizophrenia (SZ) has been reported to be minimal in previous studies. However, this could be different in first-episode schizophrenia spectrum disorders (FE-SSDs). We investigated what proportion of patients with FE-SSDs was diagnosed based on the sole presence of bizarre delusions (BDs) or first rank auditory hallucinations (FRAHs). Their alternative diagnosis by the DSM-5 was established and diagnostic stability over 1-year was identified.
Methods:
This was a retrospective review study on the medical records, case report forms for the subjects with FE-SSDs (n=404) participated in the Korea Early Psychosis Study. The two Japanese sites reviewed retrospectively only medical records of the subjects with FE-SSDs (n=103). We used three different definitions of BDs (strict, narrow, and broad) and specified subtypes of Other Specified Schizophrenia spectrum and Other psychotic disorders (OSSOs). To ensure inter-rater reliability between the hospitals, regular zoom meetings were held.
Results:
Forty (7.89%) subjects out of 507 were found to be diagnosed as SSDs based on the sole presence of BDs or FRAHs. All these patients met the criteria of OSSOs and were classified as having pure delusion (n=22), delusion with attenuated auditory hallucinations (AHs) (n=5), pure AHs (n=3) and AHs with attenuated delusion (n=10). The patients with first and second subtypes (n=27) were found to have BDs. The BDs fulfilled mostly strict definitions or satisfied the next broadest definition. The diagnostic stability of FE-OSSOs and its subgroups (first and second subtypes) over 1-year was substantially high (70.27% and 84% respectively).
Conclusion
These findings suggest that more rigorous diagnostic assessment should be performed especially to differentiate OSSOs from SZ in patients with FE-SSDs and more refined classification of the subtypes for OSSOs considered in the next DSM revision.
10.Effects of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Criteria Changes for Schizophrenia on Diagnoses of First-Episode Schizophrenia Spectrum Disorders
WooRi CHO ; Sung-Wan KIM ; Seung-Hee WON ; Bong-Ju LEE ; Naohisa TSUJINO ; Youji TAKUBO ; Taiju YAMAGUCHI ; Takahiro NEMOTO ; Ling LI ; Thi-Hung LE ; Fatima Zahra RAMI ; Young-Chul CHUNG
Psychiatry Investigation 2025;22(2):212-217
Objective:
Impact of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) changes on the criteria for schizophrenia (SZ) has been reported to be minimal in previous studies. However, this could be different in first-episode schizophrenia spectrum disorders (FE-SSDs). We investigated what proportion of patients with FE-SSDs was diagnosed based on the sole presence of bizarre delusions (BDs) or first rank auditory hallucinations (FRAHs). Their alternative diagnosis by the DSM-5 was established and diagnostic stability over 1-year was identified.
Methods:
This was a retrospective review study on the medical records, case report forms for the subjects with FE-SSDs (n=404) participated in the Korea Early Psychosis Study. The two Japanese sites reviewed retrospectively only medical records of the subjects with FE-SSDs (n=103). We used three different definitions of BDs (strict, narrow, and broad) and specified subtypes of Other Specified Schizophrenia spectrum and Other psychotic disorders (OSSOs). To ensure inter-rater reliability between the hospitals, regular zoom meetings were held.
Results:
Forty (7.89%) subjects out of 507 were found to be diagnosed as SSDs based on the sole presence of BDs or FRAHs. All these patients met the criteria of OSSOs and were classified as having pure delusion (n=22), delusion with attenuated auditory hallucinations (AHs) (n=5), pure AHs (n=3) and AHs with attenuated delusion (n=10). The patients with first and second subtypes (n=27) were found to have BDs. The BDs fulfilled mostly strict definitions or satisfied the next broadest definition. The diagnostic stability of FE-OSSOs and its subgroups (first and second subtypes) over 1-year was substantially high (70.27% and 84% respectively).
Conclusion
These findings suggest that more rigorous diagnostic assessment should be performed especially to differentiate OSSOs from SZ in patients with FE-SSDs and more refined classification of the subtypes for OSSOs considered in the next DSM revision.