At least eight inherited neurodegenerative diseases are caused by expanded CAG repeats encoding polyglutamine (polyQ) stretches. Although cytotoxicities of expanded polyQ stretches are implicated, the molecular mechanisms of neurodegeneration remain unclear. We found that expanded polyQ stretches preferentially bind to TAFII130, a coactivator involved in cAMP-responsive element binding protein (CREB)-dependent transcriptional activation, and strongly suppress CREB-dependent transcriptional activation. The suppression of CREB-dependent transcription and the cell death induced by polyQ stretches were restored by the co-expression of TAFII130. Our results indicate that interference of transcription by the binding of TAFII130 with expanded polyQ stretches is involved in the pathogenetic mechanisms underlying neurodegeneration.

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Background and Aim:  Several recent studies have reported that liver cirrhosis (LC) can be ameliorated, but few adequate strategies are available against liver fibrosis. Although LC clinically shows thrombocytopenia and hypersplenism, the correlation with liver fibrosis and platelets remains unclear. The aim of the present study was to investigate the effect of platelets on liver fibrosis in mouse models. Methods:  To induce liver fibrosis, C57BL6 female mice were injected i.p. with 1 mL/kg carbon tetrachloride (CCl4) twice a week for 8 weeks. Thrombocytosis was achieved by giving thrombopoietin or splenectomy in addition to CCl4 intoxication. At 8 weeks, whole blood and liver specimens were obtained for studies as follows: peripheral platelet counts, histopathological examination, hydroxyproline assay, immunostaining, quantification of mRNA expression, and microarray analysis. Results:  Thrombocytosis significantly reduced liver fibrosis and hydroxyproline content of liver tissues compared to mice with CCl4 administration alone. Platelets suppressed increments in mRNA expression for transforming growth factor‐β, and increased matrix metalloproteinase‐9 expression in the liver. Microarray analysis of the liver revealed that platelets upregulated gene expressions involved in cell proliferation compared to expression in mice with CCl4 intoxication alone. Platelets also increased liver volume, proliferative cell nuclear antigen labeling index, and mitotic index in fibrotic mice. Conclusion:  These results clearly show that platelets reduce liver fibrosis and promote liver regeneration, even under cirrhotic conditions. We, therefore, propose that platelets could offer a potent tool in the treatment of liver cirrhosis.

Microencapsulation of genetically engineered cells has attracted much attention as an alternative nonviral strategy to gene therapy. Though smaller microcapsules (i.e. less than 300 microm) theoretically have various advantages, technical limitations made it difficult to prove this notion. We have developed a novel microfabricated device, namely a micro-airflow-nozzle (MAN), to produce 100 to 300 microm alginate microcapsules with a narrow size distribution. The MAN is composed of a nozzle with a 60 microm internal diameter for an alginate solution channel and airflow channels next to the nozzle. An alginate solution extruded through the nozzle was sheared by the airflow. The resulting alginate droplets fell directly into a CaCl2 solution, and calcium alginate beads were formed. The device enabled us to successfully encapsulate living cells into 150 microm microcapsules, as well as control microcapsule size by simply changing the airflow rate. The encapsulated cells had a higher growth rate and greater secretion activity of marker protein in 150 microm microcapsules compared to larger microcapsules prepared by conventional methods because of their high diffusion efficiency and effective scaffold surface area. The advantages of smaller microcapsules offer new prospects for the advancement of microencapsulation technology.

We have used a laminar flow stream formed by a microfabricated nozzle array to prepare cell-encapsulated alginate gel micro-tubes, in which cells formed a cylindrical multi-cellular aggregate after cultivation for two weeks.

The objective of this study is to investigate interactions between adipocytes and breast cancer cells, and identify the responsible factors for the observed effects. In 27 breast cancer patients undergoing mastectomy, mammary adipose tissue was obtained from the breast quadrant bearing the tumor and corresponding non-tumoral quadrant. Isolated normal breast adipocytes (NBAs) and cancer-associated adipocytes (CAAs) were cultured in collagen gels to mimic the in vivo environment. Immunohistochemistry, qRT-PCR, and cell proliferation assays were performed to analyze adipocyte phenotypes. MCF7 and MDA-MB-231 breast cancer cell lines were co-cultured with adipocytes to detect phenotypic changes. Migration of MCF7 and MDA-MB-231 cells was assessed in NBA- and CAA-conditioned media. Cytokine levels in conditioned media were measured by cytokine array. Migration assays were repeated using conditioned media containing neutralizing antibodies. NBAs and CAAs lost their morphological phenotype in culture, acquiring a spindle-like shape, and CAAs showed higher cell proliferation, suggesting reversion to an immature phenotype. In co-cultures with MCF7 or MDA-MB-231 cells, NBAs exhibited increased cell proliferation, indicating acquisition of the immature phenotype of CAAs. MCF7 and MDA-MB-231 showed higher migration in a CAA-conditioned medium than in an NBA-conditioned medium. Cytokine array analysis of conditioned media revealed higher levels of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) in the CAA-conditioned medium. Neutralization experiments using antibodies against IL-6 or MCP-1 showed abrogation of migration-enhancing effects of the CAA-conditioned medium. Adipocytes revert to an immature and proliferative phenotype in the presence of breast cancer cells, and promote cancer cell migration via adipokines including IL-6 and MCP-1.

Pancreatic cancer is often associated with an intense production of interstitial collagens, known as the desmoplastic reaction. To understand more about desmoplasia in pancreatic cancer, the expression of mRNA for type I and III collagens and potent desmoplastic inducing growth factors transforming growth factor-b (TGF-b), connective tissue growth factor (CTGF), acidic and basic fibroblast growth factor (FGF), platelet-derived growth factor (PDGF) A and C and epidermal growth factor (EGF) was analysed by quantitative RT-PCR. Expression of both collagens in 23 frozen primary pancreatic cancer nodules was significantly higher than that in 15 nonneoplastic pancreatic tissues. The expressions of mRNAs for TGF-b, acidic FGF, basic FGF and PDGF C were likewise higher in surgical cancer nodules, while that of CTGF, PDGF A and EGF were not. Among these growth factors, the expression of TGF-b mRNA showed the most significant correlation with that of collagens (Po0.0001). By immunohistochemistry, TGF-b showed faint cytoplasmic staining in cancer cells. In contrast, isolated cells, mainly located on the invasive front surrounding cancerous nests, were prominently and strongly stained. These TGF-b-positive cells contained a segmented nucleus, were negative for anti-macrophage (CD68) and positive for anti-granulocyte antibodies, indicating their granulocytic nature. In conclusion, TGF-b seemed to play a major role among the various growth factors in characteristic overproduction of collagens in pancreatic cancer. Moreover, the predominant cells that express TGF-b were likely to be infiltrated granulocytes (mostly are neutrophils) and not pancreatic cancer cells.