Hyun-Kyung Park

Naringin Protects against Rotenone-induced Apoptosis in Human Neuroblastoma SH-SY5Y Cells

Rotenone, a mitochondrial complex I inhibitor, can induce the pathological features of Parkinsons disease (PD). In the present study, naringin, a grapefruit flavonoid, inhibited rotenone-induced cell death in human neuroblastoma SH-SY5Y cells. We assessed cell death and apoptosis by measuring mitogen-activated protein kinase (MAPKs) and caspase (CASPs) activities and by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Naringin also blocked rotenone-induced phosphorylation of Jun NH2-terminal protein kinase (JNK) and P38, and prevented changes in B-cell CLL/lymphoma 2 (BCL2) and BCL2-associated X protein (BAX) expression levels. In addition, naringin reduced the enzyme activity of caspase 3 and cleavages of caspase 9, poly (ADP-ribose) polymerase (PARP), and caspase 3. These results suggest that naringin has a neuroprotective effect on rotenone-induced cell death in human neuroblastoma SH-SY5Y cells.

Effects of nicotine on apoptosis in human gingival fibroblasts

AIM Cigarette smoke is a complex mixture of more than 4700 chemical compounds including free radicals and oxidants and it is a world widely known problem to health. Nicotine is the major compound of tobacco and known as the cause of gingivitis and periodontitis. It induces intracellular oxidative stress recognized as the important agent in the damage of biological molecules. The aim of this study is to clarify the cytotoxic pathway of nicotine in human gingival fibroblasts (HGFs). METHODS Human gingival fibroblasts stimulated by nicotine were used as an in vitro model. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell viability and reactive oxygen species (ROS) generation was assessed with 2,7-dichlorofluoroscein diacetate (DCF-DA). Morphological change was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) assay, stained with 4,6-diamidino-2-phenylindole (DAPI). To delineate the roles of extracellular signal-regulated kinase (ERK), P38 and c-Jun N-terminal kinase (JNK), Western blot and caspase-3 (CASP3) activity assay were performed. RESULTS Exposure of the human gingival fibroblasts to nicotine reduced cell viability by time and dose dependent and increased the generation of ROS. It also showed morphological evidence of increased apoptosis, resulted in transient activation of JNK and ERK concomitant with activation of P38, and stimulated apoptosis as evidenced by CASP3 activation and Poly ADP ribose polymerase (PARP) cleavage. CONCLUSION These results suggest that nicotine induces apoptosis through the ROS generation and CASP3 dependent pathways in HGFs.

Gene expression profile of acupuncture treatment in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease model

Abstract Objectives: To find new biomarkers by stimulating acupuncture point GB34 (Yangneungcheon) which has neuroprotective effect on the mouse model of Parkinsons disease, analysis of cDNA microarray on mRNAs of the substantia nigra was performed. Methods: Male C57BL/6 mice were divided into two groups: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mice (MPTP group, n=3); 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and acupuncture (GB34)-treated mice (MPTP + ACU group, n=3). The mice received an intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (30 mg/kg) once daily for 3 consecutive days. Manual acupuncture was performed 2 hours after every injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The total RNA in the substantia nigra of each mouse was isolated on 3 days after the last 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injection. Agilent mouse whole genome 44K chip was used for microarray analysis and the hybridization image was analysed by GenePix Pro 6.0. Data normalization and analysis were performed using GeneSpring GX 7.3.1 program. Results: The acupuncture stimulation revealed 799 genes (424 up- and 375 down-regulated) of which expression levels were changed more than two-folds in the MPTP + ACU group, compared to the MPTP group. The genes selected were classified into several categories based on their functions using DAVID Bioinformatics Resources 2008 (http://david.abcc.ncifcrf.gov/) and KEGG PATHWAY Database (http://www.genome.jp/kegg/pathway.html). Discussion: Biomarkers in response to acupuncture stimulation to GB34 were identified in a mouse model for Parkinsons disease. These biomarkers might provide a promising clue for understanding the neuroprotective effect of acupuncture in Parkinsons disease.

No association between polymorphisms of WNT2

BackgroundWingless-type MMTV integration site family member 2 (WNT2) has a potentially important role in neuronal development; however, there has yet to be an investigation into the association between single nucleotide polymorphisms (SNPs) of WNT2 and schizophrenia. This study aimed to determine whether certain SNPs of WNT2 were associated with schizophrenia in a Korean population.Methodse genotyped 7 selected SNPs in the WNT2 gene region (approximately 46 Kb) using direct sequencing in 288 patients with schizophrenia and 305 healthy controls.ResultsOf the SNPs examined, one SNP showed a weak association with schizophrenia (p = 0.017 in the recessive model). However, this association did not remain statistically significant after Bonferroni correction.ConclusionThe present study does not support a major role for WNT2 in schizophrenia. This could be due to the size of the population. Therefore, additional studies would be needed to definitively rule out the genes minor effects.

Prevalence of monoclonal gammopathy of undetermined significance in an elderly urban Korean population

Research on the epidemiology of monoclonal gammopathy of undetermined significance (MGUS) is limited in Korea. The aim of this study was to determine the prevalence and characteristics of MGUS in an elderly urban Korean population. A random sample of 1118 Korean elders was selected from residents aged 65 years or older living in Seongnam, Korea 1 year from August 2005. We obtained plasma samples remaining after scheduled tests for the Korean Longitudinal Study on Health and Aging. The mean age of the study population was 72 years (range, 65–97 years). To screen for MGUS, immunofixation and free light‐chain (FLC) assays were performed. Age‐adjusted and gender‐adjusted MGUS prevalence rates in 680 responders were estimated as 3.3% [95% confidence interval (CI) = 2.0–4.6%], and the estimated age‐adjusted prevalence of MGUS was 4.3% in men (95% CI = 1.9–6.6%) and 2.6% in women (95% CI = 1.0–4.2%). Abnormal FLC ratios were detected in 10% of MGUS cases. Multivariate analysis of 945 participants revealed that significant risk factors for MGUS included advanced age, male sex, hyperproteinemia, increased erythrocyte sedimentation rate, and abnormal FLC ratio. MGUS is less prevalent among elderly Koreans (3.3%) than other races. This is the first study to estimate the prevalence of MGUS in the Korean elderly population. Our findings should be confirmed with additional studies analyzing follow‐up samples from 2010. Am. J. Hematol., 2011.

Toll-like receptor 1 gene polymorphisms in childhood IgA nephropathy: a case-control study in the Korean population

Toll‐like receptors (TLRs) are innate immune mediators that stimulate nuclear factor kappa B and the inflammatory cytokines. TLR1 is expressed in renal tubular epithelial cells when the kidney is injured, but the role of TLR1 gene in glomerulonephritis has not been clearly elucidated. We aimed to investigate the association of TLR1 polymorphisms with immunoglobulin A nephropathy (IgAN) in children. One hundred and ninety pediatric patients with biopsy‐proven IgAN and 283 healthy control subjects were enrolled. Two single nucleotide polymorphisms of TLR1 gene [rs4833095 (missense, Asn248Ser) and rs5743557 (promoter, −414C/T)] were selected and genotyped by direct sequencing. For rs4833095, the C/T genotype in the codominant model (vs. the T/T genotype) [odds ratio (OR) = 2.11, 95% confidence interval (CI): 1.21–3.69, P = 0.009] and the genotype containing C allele (C/T and C/C) in the dominant model (vs. the T/T genotype) (OR = 1.97, 95% CI: 1.16–3.34, P = 0.012) were associated with an increased risk of IgAN. For rs5743557, the T/T genotype in the codominant model (vs. the C/C genotype) (OR = 1.74, 95% CI: 1.02–2.96, P = 0.041) appeared to be associated with IgAN risk. In haplotype analysis, the CT haplotype revealed an association with IgAN (codominant model, OR = 1.38, 95% CI: 1.06–1.80, P = 0.017; dominant model, OR = 1.76, 95% CI: 1.16–2.67, P = 0.008). After Bonferroni correction, the association of the genotypes of rs4833095 and the CT haplotype with IgAN risk remained significant. These findings suggest that TLR1 gene polymorphisms may affect IgAN susceptibility in Korean children.

PDGFRA promoter polymorphisms are associated with the risk of papillary thyroid cancer.

Platelet-derived growth factor (PDGF) acts as a regulator in cancer development and progression. We investigated whether single nucleotide polymorphisms (SNPs) of platelet-derived growth factor receptor α polypeptide (PDGFRA) and platelet-derived growth factor receptor β polypeptide (PDGFRB) genes are associated with papillary thyroid cancer (PTC) in a Korean population. Two promoter SNPs (rs6554162, -1309A/G and rs1800812, -635G/T) of PDGFRA and one promoter SNP (rs3828610, -202A/C) of PDGFRB were genotyped using direct sequencing in 93 PTCs and 212 controls. Genetic data were analyzed using the SNPAnalyzer Pro, SNPStats and Haploview programs. Two promoter SNPs (rs6554162 and rs1800812) in PDGFRA revealed significant differences between PTC and controls (for rs6554162, p=0.0018 in the codominant model and p=0.0005 in the dominant model; for rs1800812, p=0.016 in the codominant model and p=0.007 in the dominant model). In the analysis of allele frequency, we also found that the A allele of rs6554162 (p=0.004) and the T allele of rs1800812 (p=0.029) were associated with PTC. Additionally, by haplotype analysis, the GG and AT haplotypes consisting of rs6554162 and rs1800812 were associated with PTC (GG, p=0.0033; AT, p=0.0270). However, rs3828610 in PDGFRB showed no significant difference between PTC and controls. The results suggest that PDGFRA promoter SNPs (rs6554162 and rs1800812) may be associated with the risk of PTC.

Effect by acupuncture on hypothalamic expression of maternally separated rats: proteomic approach

Abstract Objectives: Early stressors can influence the development of biological and neurological systems. Maternal separation (social isolation) in early life may increase vulnerability to neurodegenerative diseases and neuropsychiatric disorders over the lifespan. To identify new proteins on acupuncture effects in maternally separated rats, an animal model for study of early environmental insults, proteomic approach on the expression of the hypothalamic proteins was performed. Methods: On post-natal day 14, rat pups were randomly divided into four groups: pups kept with their mothers for 7 days; pups kept with their mothers with acupuncture daily to HT8 (Sobu); maternally separated pups; maternally separated pups with acupuncture. The hypothalamic proteins were analysed by two-dimensional electrophoresis coupled with matrix assisted laser desorption/ionization time-of-flight mass spectrometer. Results: The results showed that 27 spots were differentially and commonly expressed. Of 27 spots, 21 spots were identified while six spots were not, and 15 proteins were known proteins. In maternally separated group, the expressions of 14 proteins were down-regulated, compared to control group. In group of maternally separation with acupuncture, five proteins were down-regulated and nine were up-regulated, compared to the maternally separated group. Among nine proteins up-regulated by acupuncture treatment, we found four proteins (dihydropyrimidinase-like 2, dystrophin-related protein 2, tubulin, alpha 1a and syntaxin 1b) related to neurodevelopment. Discussion: The result suggests that acupuncture to HT8 may affect neurodevelopment, and acupuncture may be a possible therapy for neurodevelopmental disorders.

Association of the -2510A/G chemokine (C-C motif) ligand 2 polymorphism with knee osteoarthritis in a Korean population.

Objective: To investigate the possible association between polymorphisms [the −2510A/G promoter polymorphism (rs1024611) and the Cys35Cys coding polymorphism (rs4586) in exon 2] of the chemokine (C–C motif) ligand 2 (CCL2) gene and knee osteoarthritis (OA) in a Korean population. Methods: DNA was obtained from 153 Korean primary knee OA patients and 270 healthy controls. CCL2 genomic variants (−2510A/G and Cys35Cys polymorphisms) were detected by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP). In additional, the effect of −2510A/G on CCL2 transcription was examined, using a luciferase reporter gene construct transfected into HMC‐1 cells. Results: The −2510A/G promoter polymorphism was associated with OA [genotype frequency, p = 0.041; allele frequency, p = 0.017, odds ratio (OR) = 1.45, 95% confidence interval (CI) = 1.07–1.96]. Significant association was observed between the G carrier of the −2510A/G promoter polymorphism and primary knee OA patients (p = 0.021, OR = 2.25, 95% CI = 1.12–4.52). The G carrier of the −2510A/G promoter polymorphism was also associated with both clinically subtyped OA patients (OA patients with functionally poor index and radiographically severe OA patients). However, no significant difference was found in the Cys35Cys polymorphism. Haplotype frequency analysis revealed a significant difference (χ2 = 8.98, p = 0.030). The CCL2 serum level of subjects with the G carrier (290.0±87.5 pg/mL) of the −2510A/G promoter polymorphism was statistically higher than that of subjects with the non‐G carrier (161.5±48.3 pg/mL). The luciferase activity was significantly greater from interleukin (IL)‐1β‐induced cells transfected with constructs containing G at position −2510. Conclusions: The G carrier of the −2510A/G promoter polymorphism was found to be associated with primary knee OA, and could be a susceptibility factor in the development of primary knee OA in the Korean population.

Protective effect of histamine H2 receptor antagonist ranitidine against rotenone-induced apoptosis.

Histamine H(2) receptor antagonists have been reported to improve the motor symptoms of Parkinsons disease (PD) patients and to exert neuroprotective effects. In this study, we investigated the protective effects of the H(2) receptor antagonist ranitidine on rotenone-induced apoptosis in human dopaminergic SH-SY5Y cells, focusing on mitogen-activated protein kinases (MAPKs) and caspases (CASPs)-mediated apoptotic events. Ranitidine blocked the rotenone-induced phosphorylation of c-Jun NH(2)-terminal protein kinase (JNK) and P38 MAPK (P38), and promoted the phosphorylation of extracellular signal-regulated protein kinase (ERK). Ranitidine also prevented the down-regulation of B-cell CLL/lymphoma 2 (BCL2) and the up-regulation of BCL2-associated X protein (BAX) by rotenone. Furthermore, ranitidine not only attenuated rotenone-induced cleavages of CASP9, poly(ADP-ribose) polymerase-1 (PARP) and CASP3, but also suppressed CASP3 enzyme activity. These results indicate that ranitidine protects against rotenone-induced apoptosis, inhibiting phosphorylation of JNK and P38, and activation of CASPs in human dopaminergic SH-SY5Y cells.