Numerous hypotheses have been put forth over the years to explain the development of bipolar disorder. Of these, circadian rhythm hypotheses have gained much importance of late. While the hypothalamus-pituitary-adrenal (HPA) axis hyperactivation hypothesis and the monoamine hypothesis somewhat explain the pathogenic mechanism of depression, they do not provide an explanation for the development of mania/hypomania. Interestingly, all patients with bipolar disorder display significant disruption of circadian rhythms and sleep/wake cycles throughout their mood cycles. Indeed, mice carrying the Clock gene mutation exhibit an overall behavioral profile that is similar to human mania, including hyperactivity, decreased sleep, lowered depression-like behavior, and lower anxiety. It was recently reported that monoamine signaling is in fact regulated by the circadian system. Thus, circadian rhythm instability, imposed on the dysregulation of HPA axis and monoamine system, may in turn increase individual susceptibility for switching from depression to mania/hypomania. In addition to addressing the pathophysiologic mechanism underlying the manic switch, circadian rhythm hypotheses can explain other bipolar disorder-related phenomena such as treatment resistant depression and mixed features.
Animals ; Bipolar Disorder* ; Chronobiology Disorders ; Circadian Rhythm* ; Depression ; Depressive Disorder, Treatment-Resistant ; Humans ; Mice

BACKGROUND: Parkinson disease (PD) is caused by selective cell death of dopaminergic neurons in the substantia nigra. An early onset form of PD, autosomal recessive juvenile parkinsonism has been associated with a mutation in the parkin gene. The function of parkin is known to remove misfolding proteins and protect cell death. We aimed to investigate the role of parkin against oxidative stress in neuronal cells. METHODS: Parkin knockout embryonic stem cells (PKO ES cells) were differentiated into neurons by adherent monolayer culture method. Oxidative stress was induced by the treatment of 1-methyl-4-phenylpyridinium (MPP+) in neurons derived from wild type and PKO ES cells, and cell viability was examined by MTT assay. After exposure to MPP+, Tuj1-positive cell population was compared between PKO and wild type cells by fluorescence activated cell sorter (FACS) analysis. The activated caspase3 protein level was also measured by Western blot analysis, FACS and immunocytochemistry. RESULTS: There was no difference in the efficiency of neuronal differentiation between wild type and PKO ES cells. After exposure to MPP+, no significant differences were found in cell viability and Tuj1-positive cell population between the two groups determined by MTT assay and FACS analysis, respectively. The activated caspase3 protein levels examined by Western blot analysis, FACS and immunocytochemistry were not changed in PKO cells compared with those of wild type cells after MPP+ treatment. CONCLUSION: These results suggest that PKO neuronal cells including dopaminergic neurons are not sensitive to caspase3-dependent cell death pathway during the response against MPP+-induced oxidative stress.
1-Methyl-4-phenylpyridinium ; Blotting, Western ; Cell Death ; Cell Survival ; Dopaminergic Neurons ; Embryonic Stem Cells ; Fluorescence ; Immunohistochemistry ; Neurons ; Oxidative Stress* ; Parkinson Disease ; Parkinsonian Disorders ; Substantia Nigra

OBJECTIVE: Previous studies have suggested an association between CACNA1C and susceptibility of bipolar disorder. In this study, we examined the association of CACNA1C variants with bipolar disorder in the Korean population. METHODS: We selected 2 CACNA1C single nucleotide polymorphisms (SNPs), namely, rs723672 and rs1051375, based on their functions and minor allele frequencies described in previous studies. Genotypes of these 2 SNPs were analyzed by extracting DNA from blood samples collected from 287 patients with bipolar disorder and 340 healthy controls. RESULTS: Genotype frequencies of both rs723672 and rs1051375 SNPs were significantly different in patients and controls (p=0.0462 and 1.732E-14, respectively). Dominant, recessive, and allele models showed significant differences between patients and controls with respect to the rs1051375 SNP (p=1.72E-11, 4.17E-10, 4.95E-16, respectively). CONCLUSION: Our results suggested that CACNA1C SNPs rs723672 and rs1051375 were associated with bipolar disorder in the Korean population. In addition, our results highlighted the importance of CACNA1C in determining susceptibility to bipolar disorder.
Alleles ; Bipolar Disorder* ; DNA ; Gene Frequency ; Genotype ; Humans ; Polymorphism, Single Nucleotide

Vimentin is an intermediate filament that regulates cell attachment and subcellular organization. In this study, vimentin filaments were morphologically altered, and its soluble subunits were rapidly reduced via cadmium chloride treatment. Cadmium chloride stimulated three major mitogen-activated protein kinases (MAPKs): extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, and led apoptotic pathway via caspase-9 and caspase-3 activations. In order to determine whether MAPKs were involved in this cadmium-induced soluble vimentin disappearance, we applied MAPK- specific inhibitors (PD98059, SP600125, SB203580). These inhibitors did not abolish the cadmium-induced soluble vimentin disappearance. Caspase and proteosome degradation pathway were also not involved in soluble vimentin disappearance. When we observed vimentin levels in soluble and insoluble fractions, soluble vimentin subunits shifted to an insoluble fraction. As we discovered that heat- shock protein 27 (HSP27) was colocalized and physically associated with vimentin in unstressed cells, the roles of HSP27 with regard to vimentin were assessed. HSP27-overexpressing cells prevented morphological alterations of the vimentin filaments, as well as reductions of soluble vimentin, in the cadmium-treated cells. Moreover, HSP27 antisense oligonucleotide augmented these cadmium-induced changes in vimentin. These findings indicate that HSP27 prevents disruption of the vimentin intermediate filament networks and soluble vimentin disappearance, by virtue of its physical interaction with vimentin in cadmium-treated SK-N-SH cells.
Cadmium/*pharmacology ; Caspases/metabolism ; Cell Line ; Heat-Shock Proteins/*metabolism ; Humans ; Mitogen-Activated Protein Kinases/metabolism ; Protein Binding/drug effects ; Protein Subunits/chemistry/metabolism ; Solubility/drug effects ; Vimentin/*chemistry/*metabolism

Bipolar disorder (BD), characterized by recurrent mood swings between depression and mania, is a highly heritable and devastating mental illness with poorly defined pathophysiology. Recent genome-wide molecular genetic studies have identified several protein-coding genes and microRNAs (miRNAs) significantly associated with BD. Notably, some of the proteins expressed from BD-associated genes function in neuronal synapses, suggesting that abnormalities in synaptic function could be one of the key pathogenic mechanisms of BD. In contrast, however, the role of BD-associated miRNAs in disease pathogenesis remains largely unknown, mainly because of a lack of understanding about their target mRNAs and pathways in neurons. To address this problem, in this study, we focused on a recently identified BD-associated but uncharacterized miRNA, miR-1908-5p. We identified and validated its novel target genes including DLGAP4, GRIN1, STX1A, CLSTN1 and GRM4, which all function in neuronal glutamatergic synapses. Moreover, bioinformatic analyses of human brain expression profiles revealed that the expression levels of miR-1908-5p and its synaptic target genes show an inverse-correlation in many brain regions. In our preliminary experiments, the expression of miR-1908-5p was increased after chronic treatment with valproate but not lithium in control human neural progenitor cells. In contrast, it was decreased by valproate in neural progenitor cells derived from dermal fibroblasts of a BD subject. Together, our results provide new insights into the potential role of miR-1908-5p in the pathogenesis of BD and also propose a hypothesis that neuronal synapses could be a key converging pathway of some BD-associated protein-coding genes and miRNAs.
Bipolar Disorder* ; Brain ; Computational Biology ; Depression ; Fibroblasts ; Humans ; Lithium ; MicroRNAs* ; Molecular Biology ; Neurons* ; RNA, Messenger ; Stem Cells ; Synapses* ; Valproic Acid

Purpose: Although surgical resection is usually considered for a single tumor, several reports have suggested that resection can be considered for multiple tumors. The objective of this study was to determine whether resection could provide better long-term outcome for patients with multiple hepatocellular carcinomas (HCCs) within Milan criteria. Methods: A total of 276 patients with multiple HCCs within Milan criteria with liver function preserved who underwent resection, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE) between 2009 and 2013 were analyzed. Propensity-score (PS) matching was conducted. Results: Five-year overall survival (OS) and recurrence-free survival (RFS) were better in the resection group than that in the RFA or TACE group. Patients who underwent resection had more preserved liver function and different tumor characteristics compared to those received RFA or TACE. With similar baseline characteristics generated in the PS model, there was no difference in 5-year OS among 3 groups (79.5% vs. 72.3% or 62.0%, P = 0.232), but the 5-year RFS was better for patients who received resection than those who received RFA or TACE (51.9% vs. 22.0% or 0.0%, P < 0.001). Although the major complication rate was slightly higher than RFA or TACE, there was no significant difference between the 3 groups before and after PS matching. Conclusion Resection was associated with better RFS than RFA or TACE and showed comparable OS in multiple HCC patients within the Milan criteria, but at a cost of slightly increased risk of complication. Resection can be considered as a first-line option if selected appropriately.