Huntington's disease (HD) is an incurable neurological disorder caused by an abnormal glutamine repeat expansion in the huntingtin (Htt) protein. In the present studies we investigated the role of Transducers of Regulated cAMP response element binding protein (CREB) activity (TORCs) in HD, since TORCs play an important role in expression of the transcriptional co-regulator PGC-1α, whose expression is impaired in HD. We found significantly decreased TORC1 expression levels in STHdhQ111 cells expressing mutant Htt, in the striatum of NLS-N171-82Q, R6/2 and HdhQ111 HD transgenic mice, and in postmortem striatal tissue from HD patients. TORC1 over expression in wild type and Htt striatal cells increased CREB mRNA and protein levels, PGC-1α promoter activity, mRNA expression of the PGC-1α, NRF-1, Tfam and CytC genes, mitochondrial DNA content, mitochondrial activity and mitochondrial membrane potential (MMP). TORC1 over expression also increased the resistance of striatal cells to 3-nitropropionic acid (3-NP) mediated toxicity. In cultured wild-type- and mutant Htt striatal cells, shRNA mediated TORC1 knock down resulted in decreased PGC-1α expression, and increased susceptibility to 3-NP induced toxicity. Over expression of PGC-1α partially prevented TORC-1 knock down mediated increased susceptibility of huntingtin striatal cells to 3-NP. Specific knock down of TORC1 in the striatum of NLS-N171-82Q HD transgenic mice induced neurodegeneration. Lastly, knock down of Htt prevents transcriptional repression of TORC-1 and CREB in Htt striatal cells. These findings show that impaired expression and function of TORC1, which results in reduction of PGC-1α, plays an important role in mitochondrial dysfunction in HD.

Kim Y-S, Shin S-I, Kang K-L, Herr Y, Bae W-J, Kim E-C. Nicotine and lipopolysaccharide stimulate the production of MMPs and prostaglandin E ( 2 ) by hypoxia-inducible factor-1α up-regulation in human periodontal ligament cells. J Periodont Res 2012; doi: 10.1111/j.1600-0765.2012.01487.x. ©2012 John Wiley & Sons A/S Background and Objective:  Although hypoxia-inducible factor 1α (HIF-1α) is up-regulated in the periodontal pockets of periodontitis patients, the expression and precise molecular mechanisms of HIF-1α remain unknown in human periodontal ligament cells (PDLCs). The aim of this study was to explore the effects, as well as the signaling pathway, of nicotine and lipopolysaccharide (LPS) on the expression of HIF-1α and on the production of its target genes, including cyclooxygenase-2 (COX-2)-derived prostaglandin E(2)(PGE(2)), MMP-2 and MMP-9 in PDLCs. Material and Methods:  The expression of COX-2 and HIF-1α proteins was evaluated using western blotting. The production of PGE(2) and MMPs was evaluated using enzyme immunoassays and zymography, respectively. Results:  LPS and nicotine synergistically induced the production of PGE(2), MMP-2 and MMP-9, and increased the expression of MMP-2, MMP-9, COX-2 and HIF-1α proteins. Inhibition of HIF-1α activity by chetomin or knockdown of HIF1α gene expression by small interfering RNA markedly attenuated the production of LPS- and nicotine-stimulated PGE(2) and MMPs, as well as the expression of COX-2 and HIF-1α. Furthermore, pretreatment with inhibitors of COX-2, p38, extracellular signal-regulated kinase, Jun N-terminal kinase, protein kinase C, phosphatidylinositol 3-kinase and nuclear factor-kappaB decreased the expression of nicotine- and LPS-induced HIF-1α and COX-2, as well as the activity of PGE(2) and MMPs. Conclusion:  These data demonstrate novel mechanisms by which nicotine and LPS promote periodontal tissue destruction, and provide further evidence that HIF-1α is a potential target in periodontal disease associated with smoking and dental plaque.

Encapsulation of transplanted cells within an immunoisolating membrane may provide a new strategy for protecting these cells from recipient immune responses without the use of immunosuppressive drugs. We have previously reported a novel concept of immunoisolation and immunodelusion using recipient cells instead of traditional artificial materials. We developed a chondrocyte sheeting immunodelusive immunoisolated bioartificial pancreas (CSI-BAP) that would enable transplantation of cells across allogeneic and xenogeneic barriers without the cells being recognized as donor cells and without the need for immunosuppression. Recently, we have constructed hybrid cellular spheroids (HCSs) containing cells from two different cell lines (RIN-5F, an insulin-secreting cell line, and Hep-G2, a hepatocellular carcinoma cell line) to enhance the function and biocompatibility of the HCSs. These HCSs were then encapsulated with multiple layers of chondrocyte sheets obtained from the auricular cartilage of Sprague-Dawley (SD) rats. The in vitro ability of the CSI-BAP to secrete insulin was tested before transplantation. Histological evaluation of CSI-BAP chondrocyte microencapsulated immunoisolated islet morphology and viability of allogeneic or xenogeneic cell lines was performed 100 days after the CSI-BAP was transplanted into SD rats. Morphological evaluations revealed good viability of the islets and progression of islet encapsulation. In vitro insulin secretion from the CSI-BAP was well maintained. Additionally, insulin and albumin secretion from the CSI-BAP was confirmed by in vivo immunohistochemical examination. Moreover, the cell lines transplanted into the subcutaneous space in the form of HCSs within the chondrocyte sheets showed good viability of more than 100 days and sustained insulin and albumin secreting ability.

INTRODUCTION Although Islet cell isolation and culture have been well developed, there has been little progress to prolong transplanted islet sruvival. Hepatic ischemia and insufficient neovascularization of islets are considered to be the barriers to long-term survival, Hepatocytes that survive ischemic injury have been reported to protect themeslves and regenerate using the IL-6 interleukin 6 and STAT3 pathways. MATERIALS AND METHODS The hepatocellular carcinoma (Hep-G2) cell line preconditioned for 0, 2, 4, 6, and 24 hours in a hypoxic chamber, was cocultured with rat insulin-secreting celline (RIN-5F) cells. We measured cell viabilities, insulin secretion, and p-STAT3, IL-6, and NF-κB levels. RESULTS Cocultured Hep-G2 and RIN-5F cells aggregated to form spheroids. Viabilities of Hep-G2 cells were no different after various ischemic preconditioning times, but insulin secretion increased in a time-dependent fashion with preconditioning. Western blotting showed p-STAT3, NF-κB, and IL-6 levels to increase with preconditioning time. CONCLUSION The IL-6/STAT3 pathway of Hep-G2 cells after ischemic injury showed beneficial effects on insulin secretion of RIN-5f cells cocultured with themselves.

During islet transplantation into the portal vein of the liver, the islet cells are expected to have complex interactions with hepatocytes. However, the mechanism underlying this interaction is not yet understood. Hence, we developed cellular complexes containing a mixture of human hepatocellular carcinoma cell line (Hep-G2) and rat insulin-secreting cell line (RIN-5F) by using a co-culture model and studied the function and morphology of the resultant hybrid cellular spheroids (HCSs). The RIN-5F and Hep-G2 cells were suspension cultured and, within 5 days of culture, the two types of cells aggregated to yield spheroids. The functionality of the thus formed HCSs was evaluated by measuring the levels of insulin and albumin in the culture supernatant. The HCSs retained their insulin- and albumin-secreting ability and their morphology, as revealed by immunohistological staining. The insulin and albumin levels secreted by the HCSs were considerably higher than those secreted by spheroids of single-cell origin. Generally, obtaining complexes from more than two types of cells is difficult. However, we were able to generate HCSs. We believe that this culture method could have various applications such as studying the in vitro cell-cell interactions and developing new cell transplantation models.

Improving human islet transplantation is often limited by the shortage of donors and the side effects of immunosuppressive agents. If immunoisolation is properly used, it can overcome these obstacles. Because artificial materials are adopted in this technique, however, there are still multiple issues with biocompatibility and foreign body reactions. We developed a chondrocyte microencapsulated immunoisolated islet (CMI-islet) that allows living cells to act as the immunoisolating material. To manufacture CMI-islets for xenotransplantation, isolated rat pancreatic islets were placed on low cell-binding culture dishes. Subsequently, expanded canine auricular cartiage primary cells were seeded on these dishes at a high density and maintained in a suspended state via a shaking culture system. Morphological evaluations showed good islet viability and a clear progression of the islet- encapsulation events. When the cells were challenged with glucose, they were able to secrete sufficient insulin according to glucose concentrations. The CMI-islets responded better to the glucose challenge than did nude pancreatic islets and created better glucose-insulin feedback regulation. Moreover, insulin secretion into the culture medium was confirmed over a period of 100 days, showing the survival and secretory capacity of the CMI-islet cells. By microencapsulating pancreatic islets with recipient ear cartilage cells, long-term insulin secretion can be maintained and the response to glucose challenges improved. This new immunodelusion technology differs from other immunoisolation techniques in that the donor tissue is enclosed with the recipient's tissue, thus allowing the transplanted cells to be recognized as recipient cells. This microencapsulation method may lead to developing viable xenotransplantation techniques that do not use immunosuppressive drugs.

Mycophenolic acid (MPA) is an immunosuppressive agent that is widely used in clinical therapy, including pancreas and islet transplantation. Previously, we showed that MPA induces significant apoptosis of insulin-secreting cells by downregulating RhoGDI-α and increasing JNK expression. In this study, we investigated Rac1 directly associated with RhoGDI-α during MPA-induced apoptosis in INS-1E cells (an insulin-secreting cell line). Cells were treated with MPA for 24 and 36 hours. Immunoprecipitation was used to examine physical interactions between RhoGDI-α and Rac1. Activation and immunoprecipitation assays showed expressions of Rac1 and RhoGDI-α to be directly correlated. Rac1 binding to RhoGDI-α decreased after MPA treatment, and Rac1 was induced and subsequently activated by MPA. We concluded that this novel RhoGDI-α/Rac1/JNK pathway induced apoptosis of transplanted islet cells after MPA treatment.

OBJECTIVES: We compared the clinical characteristics and outcomes of, and the bacterial genotypes in, patients with bacteraemia due to heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-susceptible S. aureus (VSSA). METHODS: A total of 268 consecutive patients with methicillin-resistant S. aureus (MRSA) bacteraemia were prospectively enrolled. All isolates were selected on the first day of bacteraemia and subjected to population analysis profiling for identification of hVISA phenotype and PCR analysis for 41 virulence factors. RESULTS: Of 268 MRSA isolates, 101 (37.7%) were identified as hVISA. Overall mortality was similar in hVISA- and VSSA-infected patients (45/101 versus 65/167; P = 0.36). The following factors were independently associated with the presence of hVISA: a vancomycin MIC ≥2 mg/L by Etest [adjusted OR (aOR), 9.98; 95% CI, 4.22-23.59], rifampicin resistance (aOR, 5.74; 95% CI, 1.35-24.37), prior vancomycin therapy (aOR, 3.04; 95% CI, 1.49-6.17) and use of immunosuppressive therapy (aOR, 2.41; 95% CI, 1.12-5.17). Among patients with hVISA, bacteraemia was more likely to persist for ≥7 days in patients with an initial vancomycin trough <15 mg/L than in those with an initial trough ≥15 mg/L (13/34 versus 5/35; P = 0.02). The hVISA and VSSA isolates were genotypically similar. CONCLUSIONS: The hVISA phenotype was present in more than one-third of MRSA isolates and was independently associated with several baseline factors. Although this phenotype did not affect patient outcomes, our results indicate that targeting an initial vancomycin trough of 15-20 mg/L may be beneficial in patients with hVISA bacteraemia.

A new Nocardia species, N. concava, was first reported in Japan in 2005. To date, there have been only 3 case reports of N. concava infection worldwide (2 in Japan and 1 in China), and only 1 of these reports has detailed the clinical characteristics of N. concava, in China. Here we report the first case of disseminated infection caused by N. concava- in a patient with a history of glucocorticoid use-in South Korea. Species identification of N. concava was done with 16S rRNA sequencing and was confirmed by biochemical tests using urea, xanthine, tyrosine, and hypoxanthine decomposition. The patient was successfully treated with trimethoprim-sulfamethoxazole.

We reported a case in which a nasogastric tube was inserted into the gastrocutaneous fistula, diagnosed by abdominal computed tomography. A 78-year-old man with a history of recurrent cerebral hemorrhage had a percutaneous endoscopic gastrostomy tube due to dysphagia for 2 years. However, soft tissue infection at the gastrostomy site caused the removal of the tube. Immediately, antibiotic agents were infused. For appropriate hydration and medication, a nasogastric tube was inserted. However, there was no significant improvement of the soft tissue infection. Moreover, the amount of bloody exudate increased. Abdominal computed tomography revealed the nasogastric tube placed under the patient's skin via gastrocutaneous fistula. The nasogastric tube was removed, and an antibiotic agents were maintained. After 3 weeks, the signs of infection fully improved, and percutaneous endoscopic gastrostomy was performed again. This case shows necessities of an appropriate interval between removal of the gastrostomy tube and insertion of a nasogastric tube, and suspicion of existence of gastrocutaneous fistula.