BACKGROUND: Although the pathogenesis of vitiligo isn't fully understood, a recent study demonstrates that oxidative stress plays an important role to induce vitiligo. Peroxiredoxin (Prx) is a novel peroxidase family to remove hydrogen peroxide using thioredoxin system, which is consisted of thioredoxin, thioredoxin reductase, and NADPH. OBJECTIVE: This study aimed to investigate the change of expression of Prx I to elucidate the role of oxidative stress in the pathogenesis of vitiligo. METHODS: Sample specimens were obtained from the lesional skin of vitiligo patients, and non-depigmented skin was obtained from the perilesional area as control samples. The skin samples were immediately frozen using liquid nitrogen, and then section samples were prepared to perform immunohistochemical staining with antibodies for Prx I. Some of the skin biopsy samples were used for primary culture of keratinocytes. Protein extracts from the expanded keratinocytes were prepared for Western blot analysis of Prx I. RESULTS: In vitiligo, the ubiquitous expression of Prx I in all layers of epidermis, which was also observed in the normal perilesional skin, was reduced in the depigmented lesion of vitiligo patients. The reduction of Prx I was remarkable from the lesions which were exposed to sunlight. Consistently, Prx I expression from the lesional keratinocytes were noticeably reduced in comparison with that from perilesional keratinocytes. CONCLUSION: Our results showing that Prx I is impaired in the epidermis of depigmented lesions of vitiligo patients suggest that oxidative stress is an important factor to induce vitiligo.
Antibodies ; Biopsy ; Blotting, Western ; Epidermis ; Humans ; Hydrogen Peroxide ; Keratinocytes ; Nitrogen ; Oxidative Stress ; Peroxidase ; Peroxiredoxins ; Skin ; Sunlight ; Thioredoxin-Disulfide Reductase ; Thioredoxins ; Vitiligo

BACKGROUND: Regular aerobic exercise is essential for the prevention and management of type 2 diabetes mellitus and may be particularly beneficial for those treated with thiazolidinediones, since it may prevent associated weight gain. This study aimed to evaluate the effect of combined exercise and rosiglitazone treatment on body composition and glucose metabolism in obese diabetes-prone animals. METHODS: We analyzed metabolic parameters, body composition, and islet profiles in Otsuka Long Evans Tokushima Fatty rats after 28 weeks of aerobic exercise, rosiglitazone treatment, and combined exercise and rosiglitazone treatment. RESULTS: Combined exercise with rosiglitazone showed significantly less increase in weight and epididymal fat compared to rosiglitazone treatment. Aerobic exercise alone and combined rosiglitazone and exercise treatment led to similar retention of lean body mass. All experimental groups showed a decrease in fasting glucose. However, the combined exercise and rosiglitazone therapy group showed prominent improvement in glucose tolerance compared to the other groups. Rescue of islet destruction was observed in all experimental groups, but was most prominent in the combined therapy group. CONCLUSION: Regular aerobic exercise combined with rosiglitazone treatment can compensate for the adverse effect of rosiglitazone treatment and has benefit for islet preservation.
Animals ; Body Composition ; Diabetes Mellitus, Type 2 ; Exercise* ; Fasting ; Glucose* ; Metabolism* ; Rats, Inbred OLETF* ; Thiazolidinediones ; Weight Gain

BACKGROUND: The human Rho guanine nucleotide exchange factor 11 (ARHGEF11) functions as an activator of Rho GTPases and is thought to influence insulin signaling. The R1467H variant of ARHGEF11 has been reported to be associated with susceptibility to type 2 diabetes mellitus (T2DM) in Western populations. METHODS: We investigated the effects of the R1467H variant on susceptibility to T2DM as well as related traits in a Korean population. We genotyped the R1467H (rs945508) of ARHGEF11 in 689 unrelated T2DM patients and 249 non-diabetic individuals and compared the clinical and biochemical characteristics according to different alleles. RESULTS: The H allele was significantly more frequent in T2DM cases than in controls (P = 0.037, 17.1% and 13.1%; respectively). H homozygocity was associated with a higher risk of T2DM compared to those with R/R or R/H genotype (odds ratio, 5.24; 95% confidence interval, 1.06 to 25.83; P = 0.042). The fasting plasma glucose, HbA1c, fasting insulin, HOMA2-IR and HOMA2-%beta levels did not differ significantly between different genotypes. CONCLUSION: Our study replicated associations of the ARHGEF11 polymorphism with increased risk of T2DM in a Korean population and thus supports previous data implicating a potential role of ARHGEF11 in the etiology of T2DM. Further studies revealing the underlying mechanism for this association are needed.
Alleles ; Diabetes Mellitus, Type 2 ; Fasting ; Genotype ; Glucose ; Guanine ; Guanine Nucleotide Exchange Factors ; Humans ; Insulin ; Plasma ; Polymorphism, Single Nucleotide ; rho GTP-Binding Proteins

Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. Notably, tumors themselves can lead to angiogenesis by inducing vascular endothelial growth factor (VEGF), which is one of the most potent angiogenic factors. Inhibition of angiogenesis is currently perceived as one of the most promising strategies for the blockage of tumor growth. In this study, we investigated the effects of Acer tegmentosum maxim water extract (ATME) on angiogenesis and its underlying signal mechanism. We studied the antiangiogenic activity of ATME by using human umbilical vein endothelial cells (HUVECs). ATME strongly inhibited VEGF-induced endothelial cell proliferation, migration, invasion, and tube formation, as well as vessel sprouting in a rat aortic ring sprouting assay. Moreover, we found that the p44/42 mitogen activated protein (MAP) kinase signaling pathway is involved in the inhibition of angiogenesis by ATME. Moreover, when we performed the in vivo matrigel plug assay, VEGF-induced angiogenesis was potently reduced when compared to that for the control group. Taken together, these results suggest that ATME exhibits potent antiangiogenic activity in vivo and in vitro and that these effects are regulated by the extracellular regulated kinase (ERK) pathway.
Acer/*metabolism ; Angiogenesis Inhibitors/*pharmacology ; Animals ; Cell Line, Tumor ; Cell Movement/drug effects ; Cell Proliferation/drug effects ; Cell Survival ; Extracellular Signal-Regulated MAP Kinases/*metabolism ; Hep G2 Cells ; Human Umbilical Vein Endothelial Cells/*drug effects ; Humans ; MAP Kinase Signaling System/drug effects ; Mice ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinase 1/metabolism ; Neoplasm Invasiveness/pathology ; Neovascularization, Pathologic/*drug therapy/prevention & control ; Nitric Oxide Synthase Type III/metabolism ; Phosphorylation/drug effects ; Plant Extracts/pharmacology ; Rats ; Rats, Sprague-Dawley ; Transcription Factors/metabolism ; Vascular Endothelial Growth Factor A/antagonists & inhibitors/metabolism