PPARgamma activation induces CD36 expression and stimulates foam cell like changes in rVSMCs

The purpose of the present study was to determine the role of peroxisome proliferator-activated receptor gamma (PPARgamma) activation in smooth muscle cell (SMC) derived form cell formation. Wild and mutant type PPARgamma were delivered by adenovirus then activated with troglitazone. The result of Oil Red O staining and FACS analysis showed that PPARgamma activation induced lipid accumulation in rVSMCs. Furthermore, PPARgamma activation reduced SMC marker genes such as alpha-actin while induced adipocyte differentiation marker genes and lipid metabolism-related genes as evidenced by RT-PCR and fluorescent immunocytochemistry. All these data demonstrate that PPARgamma activation can drive foam cell like change in rVSMCs. Our results strongly suggest that PPARgamma expression induces CD36 expression and adipocyte differentiation gene activation in the process of atherosclerosis and might be one of the crucial events in SMC derived foam cell formation.     

Enterovirus‐A71 exploits peripherin and Rac1 to invade the central nervous system

Enterovirus‐A71 (EV‐A71) has been associated with severe neurological forms of hand, foot, and mouth disease (HFMD). EV‐A71 infects motor neurons at neuromuscular junctions (NMJs) to invade the central nervous system (CNS). Here, we investigate the role of peripherin (PRPH) during EV‐A71 infection, a type III intermediate neurofilament involved in neurodegenerative conditions. In mice infected with EV‐A71, PRPH co‐localizes with viral particles in the muscles at NMJs and in the spinal cord. In motor neuron‐like and neuroblastoma cell lines, surface‐expressed PRPH facilitates viral entry, while intracellular PRPH influences viral genome replication through interactions with structural and non‐structural viral components. Importantly, PRPH does not play a role during infection with coxsackievirus A16, another causative agent of HFMD rarely associated with neurological complications, suggesting that EV‐A71 ability to exploit PRPH represents a unique attribute for successful CNS invasion. Finally, we show that EV‐A71 also exploits some of the many PRPH‐interacting partners. Of these, small GTP‐binding protein Rac1 represents a potential druggable host target to limit neuroinvasion of EV‐A71.     

Single molecule analysis indicates stimulation of MUTYH by UV-DDB through enzyme turnover

The oxidative base damage, 8-oxo-7,8-dihydroguanine (8-oxoG) is a highly mutagenic lesion because replicative DNA polymerases insert adenine (A) opposite 8-oxoG. In mammalian cells, the removal of A incorporated across from 8-oxoG is mediated by the glycosylase MUTYH during base excision repair (BER). After A excision, MUTYH binds avidly to the abasic site and is thus product inhibited. We have previously reported that UV-DDB plays a non-canonical role in BER during the removal of 8-oxoG by 8-oxoG glycosylase, OGG1 and presented preliminary data that UV-DDB can also increase MUTYH activity. In this present study we examine the mechanism of how UV-DDB stimulates MUTYH. Bulk kinetic assays show that UV-DDB can stimulate the turnover rate of MUTYH excision of A across from 8-oxoG by 4–5-fold. Electrophoretic mobility shift assays and atomic force microscopy suggest transient complex formation between MUTYH and UV-DDB, which displaces MUTYH from abasic sites. Using single molecule fluorescence analysis of MUTYH bound to abasic sites, we show that UV-DDB interacts directly with MUTYH and increases the mobility and dissociation rate of MUTYH. UV-DDB decreases MUTYH half-life on abasic sites in DNA from 8800 to 590 seconds. Together these data suggest that UV-DDB facilitates productive turnover of MUTYH at abasic sites during 8-oxoG:A repair.     

Selective removal of anti-α-Gal antibodies from human serum by using synthetic α-Gal epitope on a core-shell type resin

A novel α-Gal resin was chemo-enzymatically synthesized for the efficient adsorption of anti-α-Gal antibodies in human serum for xenotransplantation. To covalently conjugate a hexanoate linker with lactose and N-acetylglucosamine, both acceptor sugars were acetylated and brominated. Then, α-and β-galactoses were sequentially added to the linker-containing saccharides at their non-reducing ends by using recombinant α-(1,3)-and β-(1,4)-galactosyltransferases from E. coli. Finally, the synthesized α-Gal derivatives were immobilized on HiCore, a core-shell type resin, that was functionalized with amino groups on the shell region, as a packing material on-column. Using this method we were able to demonstrate that the α-Gal HiCore resin had a reduced level of non-specific protein adsorption compared with the commercially available polystyrene supports, TentaGel, and agarose-based supports, when Lectin BS-I was used as the model binding protein. Furthermore, the α-Gal HiCore resin was more efficient at eliminating anti-α-Gal IgGs from the total human IgGs through immunoadsorption than the other two α-Gal resins, α-Gal TentaGel and α-Gal agarose. The α-Gal HiCore resin developed in this study can be utilized in a wide range of applications including ex vivo immunoadsorption and as a quantitative assay of anti-Gal antibody in human sera.     

Metformin ameliorates olanzapine-induced disturbances in POMC neuron number,axonal projection,and hypothalamic leptin resistance

Antipsychotics have been widely accepted as a treatment of choice for psychiatric illnesses such as schizophrenia. While atypical antipsychotics such as aripiprazole are not associated with obesity and diabetes, olanzapine is still widely used based on the anticipation that it is more effective in treating severe schizophrenia than aripiprazole, despite its metabolic side effects. To address metabolic problems, metformin is widely prescribed. Hypothalamic proopiomelanocortin (POMC) neurons have been identified as the main regulator of metabolism and energy expenditure. Although the relation between POMC neurons and metabolic disorders is well established, little is known about the effects of olanzapine and metformin on hypothalamic POMC neurons. In the present study, we investigated the effect of olanzapine and metformin on the hypothalamic POMC neurons in female mice. Olanzapine administration for 5 days significantly decreased Pomc mRNA expression, POMC neuron numbers, POMC projections, and induced leptin resistance before the onset of obesity. It was also observed that coadministration of metformin with olanzapine not only increased POMC neuron numbers and projections but also improved the leptin response of POMC neurons in the olanzapine-treated female mice. These findings suggest that olanzapine-induced hypothalamic POMC neuron abnormality and leptin resistance, which can be ameliorated by metformin administration, are the possible causes of subsequent hyperphagia.     

Identification of parasite DNA in common bile duct stones by PCR and DNA sequencing

We attempted to identify parasite DNA in the biliary stones of humans via PCR and DNA sequencing. Genomic DNA was isolated from each of 15 common bile duct (CBD) stones and 5 gallbladder (GB) stones. The patients who had the CBD stones suffered from cholangitis, and the patients with GB stones showed acute cholecystitis, respectively. The 28S and 18S rDNA genes were amplified successfully from 3 and/or 1 common bile duct stone samples, and then cloned and sequenced. The 28S and 18S rDNA sequences were highly conserved among isolates. Identity of the obtained 28S D1 rDNA with that of Clonorchis sinensis was higher than 97.6%, and identity of the 18S rDNA with that of other Ascarididae was 97.9%. Almost no intra-specific variations were detected in the 28S and 18S rDNA with the exception of a few nucleotide variations, i.e., substitution and deletion. These findings suggest that C. sinensis and Ascaris lumbricoides may be related with the biliary stone formation and development.