Min Yoo

Aquaporin 3 expression is up-regulated by TGF-β1 in rat peritoneal mesothelial cells and plays a role in wound healing.

Aquaporin 3 (AQP3) is expressed in many tissues including the peritoneum and kidney. In cultured mesothelial cells, glucose up-regulates AQP3, which may be important for water transport through the peritoneal membrane. However, there has been no research into the role of AQP3 in human peritoneal mesothelial cell (HPMC) migration or peritoneal fibrosis. We investigated the effects of transforming growth factor-β1 (TGF-β1) on AQP3 expression in HPMCs. We also investigated the role of AQP3 in the peritoneal wound healing process in rats. Chronic exposure to glucose-containing solution increased peritoneal myofibroblasts, with TGF-β1 and AQP3 expression in a model of long-term peritoneal dialysis. In vitro, TGF-β1 induced AQP3 expression in HPMCs. AQP3 knockdown by small-interfering RNA inhibited TGF-β1-induced AQP3 and α-smooth muscle actin expression and also slowed HPMC migration. AQP3 overexpression induced faster migration of HPMCs. Treatment with an extracellular signal-regulated kinase inhibitor and p38 kinase inhibitor attenuated TGF-β1-induced AQP3 expression in HPMCs. These data suggest that TGF-β1 induces AQP3 and that AQP3 has a critical role in TGF-β-induced HPMC migration. These findings provide evidence of a novel role for AQP3 in peritoneal fibrosis and wound healing. The effect of TGF-β1 on AQP3 expression in HPMCs is mediated, at least in part, by ERK and p38 signaling.

Association of Adiponectin Polymorphisms with Type 2 Diabetes in Korean Population

Type 2-diabetes is a typical polygenic disease complex, for which several common risk alleles have been identified. Adiponectin, which modulates insulin resistance as well as glucose and lipid metabolism, has recently been associated with type 2-diabetes (T2DM). Therefore, we investigated the genotype for the T45G and G267T polymorphisms in adiponectin genes in the Korean population and compared genotypes of patients with those of a control group. 100 patients (63 male, 37 female), who previously underwent T2DM and 100 controls (36 male, 63 female) participated in this study. There was a strong association between T45G polymorphism in the adiponectin gene and T2DM. The present study shows that adiponectin T45G polymorphism may be associated with the pathogenesis of T2DM. Further studies with a larger population may be needed for the development of diagnostic methods at genetic levels such as DNA chip.

Association of Hepatocyte Nuclear factor-4α Polymorphisms with Type 2 Diabetes in Koreans

Type 2 diabetes is a typical polygenic disease complex, for which several common risk alleles have been identified. The hepatocyte nuclear factor- (HNF-), a transcription factor involved in the regulation of serum lipid and glucose levels, has recently been associated with type 2 diabetes. Therefore, we investigated the genotype for the C>T polymorphism at position 12352 of the HNF- gene in Koreans and compared patient genotypes with those of the control group. 100 patients (63 males, 37 females) with a history of type 2 diabetes (T2DM) and 100 controls (36 males, 64 females) participated in this study. There was no association between 12352 C>T polymorphism in the HNF- gene and T2DM. The present study shows that HNF- 12352 C>T polymorphism may not be associated with the pathogenesis of T2DM. Further studies with larger populations may be needed for the development of diagnostic methods at a genetic level such as DNA chip.

Studies on the Toxicity of Benzophenone in the Developing Chick Embryo

Endocrine disruptors are chemicals which can be found in our normal daily lives. Chemicals such as bisphenol A, DDT, benzophenone and phenylphenol can be easily ingested through plastic food containers and pesticides. Endocrine disruptors can be very harmful and toxic because they disrupt the normal function of the endocrine system. It has been reported that endocrine disruptions can cause fatal strikes in the cardiovascular, reproductive, and central nervous systems, and other parts of the body. Therefore we examined if benzophenone as an endocrine disruptor inhibits development in or induces malformation of chick embryos. Chick embryos which received a single injection of benzophenone (/egg /egg) via the yolk sac at designated times (6, 9, 12, 15, 18 and 21 days after incubation) were investigated. Body weight reduction was observed in middle doses (/egg /egg). High mortality rates and teratogenic signs such as abnormal wry beak and abnormal eyeballs were seen in high doses (/egg /egg). In conclusion, it is suggested that benzophenone induces malformation of chick embryos and seriously inhibits development.