Chul-hoon Kim

Nonalcoholic fatty liver disease (NAFLD) has become the most common form of liver disease, affecting 20% to 30% of the US population. Its clinical manifestations are usually absent or subtle, and it usually comes to medical attention incidentally when aminotransferase levels are found to be elevated or a radiographic study reveals that the liver is fatty. Primary NAFLD is now considered the hepatic manifestation of the metabolic syndrome. The pathogenesis is thought to be a multiple-hit process

Metabotropic glutamate receptors (mGluRs) play important roles in neurotransmission, neuronal development, synaptic plasticity, and neurological disorders. Recent studies have revealed a sophisticated interplay between mGluRs and protein kinases: activation of mGluRs regulates the activity of a number of kinases, and direct phosphorylation of mGluRs affects receptor signaling, trafficking, and desensitization. Here we review the emerging literature on mGluR phosphorylation, signaling, and synapt

The activation of Group 1 metabotropic glutamate receptors, mGluR5 and mGluR1alpha, triggers intracellular calcium release; however, mGluR5 activation is unique in that it elicits Ca2+ oscillations. A short region of the mGluR5 C terminus is the critical determinant and differs from the analogous region of mGluR1alpha by a single amino acid residue, Thr-840, which is an aspartic acid (Asp-854) in mGluR1alpha. Previous studies show that mGluR5-elicited Ca2+ oscillations require protein kinase C (

Pyrrolidine dithiocarbamate (PDTC) is a potent inhibitor of nuclear factor kappa B (NF-kappaB) activation. PDTC inhibited basal NF-kappaB activity of endothelial cells. PDTC, however, failed to inhibit basal NF-kappaB activity after withdrawal of serum in the media, and the inhibitory effect of PDTC could be restored by addition of zinc. When various preparations of metal ion-EDTA were tested with PDTC in serum-containing media, only Zn-EDTA failed to block the inhibitory effect of PDTC. The dep

The antioxidant and metal-chelating effects of pyrrolidine dithiocarbamate (PDTC) have been extensively studied. PDTC prevents cell death induced by various insults. However, PDTC itself may cause cell death in selected experimental paradigms. PDTC induced bovine cerebral endothelial cell death. However, in serum-depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. The metal chelators bathocuproine disulfonic

Hyperphosphorylated tau is a main component of neurofibrillary tangles, a pathological hallmark of Alzheimer's disease (AD). There is evidence that various protein kinases are involved in tau hyperphosphorylation. However, little is known about AD-related stimuli that activates tau kinases. We investigated the role of zinc, a metal involved in AD pathology, in tau phosphorylation. Zinc increased the phosphorylation of serine 214 (S214) in tau protein in human wild-type tau1-441-expressing SH-SY5

These data suggest that genetic variations in TCF7L2, SLC30A8, HHEX, CDKAL1, CDKN2A/B, and KCNQ1 are associated with PTDM in Korea.

Incretin hormone-based therapy in type 2 diabetes has been widely used, and dipepdityl peptidase-4 (DPP-4) inhibitors, which prevent incretin degradation, have become popular oral hypoglycemic agents. The efficacy of DPP-4 inhibitors varies from individuals, and factors determining responses to DPP-4 inhibitors have not been fully established. We aimed to investigate whether genetic variations in glucagon-like peptide (GLP-1) receptor are associated with responses to DPP-4 inhibitors in patients

Mechanically gated ion channels convert sound into an electrical signal for the sense of hearing. In Drosophila melanogaster, several transient receptor potential (TRP) channels have been implicated to be involved in this process. TRPN (NompC) and TRPV (Inactive) channels are localized in the distal and proximal ciliary zones of auditory receptor neurons, respectively. This segregated ciliary localization suggests distinct roles in auditory transduction. However, the regulation of this localizat

Abstract The neurobiological basis of social dysfunction and the high male prevalence in autism spectrum disorder (ASD) remain poorly understood. Although network alterations presumably underlie the development of autistic-like behaviors, a clear pattern of connectivity differences specific to ASD has not yet emerged. Because the heterogeneous nature of ASD hinders investigations in human subjects, we explored brain connectivity in an etiologically homogenous rat model of ASD induced by exposure

Cilia are highly specialized antennae-like cellular organelles. Inositol polyphosphate 5-phosphatase E (INPP5E) converts PI(4,5)P2 into PI4P and is required for proper ciliary function. Although Inpp5e mutations are associated with ciliopathies in humans and mice, the precise molecular role INPP5E plays in cilia remains unclear. Here, we report that Drosophila INPP5E (dINPP5E) regulates ciliary protein trafficking by controlling the phosphoinositide composition of ciliary membranes. Mutations in