Peroxisome proliferator-activated receptor gamma (PPARγ) is a critical regulator of carbohydrate and lipid metabolism, adipocyte differentiation and inflammatory response. Post-translational modification of PPARγ and its degradation involve several pathways, including the ubiquitin-proteasome system. Here, we identified F-box only protein 9 (FBXO9) as an E3 ubiquitin ligase of PPARγ.
View Article and Find Full Text PDFThe current diabetes mellitus pandemic constitutes an important global health problem. Reductions in the mass and function of β-cells contribute to most of the pathophysiology underlying diabetes. Thus, physiological control of blood glucose levels can be adequately restored by replacing functioning β-cell mass.
View Article and Find Full Text PDFThe direct differentiation of hepatocytes from bone marrow cells remains controversial. Several mechanisms, including transdifferentiation and cell fusion, have been proposed for this phenomenon, although direct visualization of the process and the underlying mechanisms have not been reported. In this study, we established an efficient in vitro culture method for differentiation of functioning hepatocytes from murine lineage-negative bone marrow cells.
View Article and Find Full Text PDFIn this study, the effects of autologous islet transplantation (ITx) were compared to those of oral antidiabetic drugs (OAD) after distal pancreatectomy (NCT01922492). We enrolled nondiabetic patients who underwent distal pancreatectomy for benign tumors. In the ITx group, islets were isolated from the normal part of the resected pancreas and implanted via the portal vein.
View Article and Find Full Text PDFThe objective of this study is to investigate whether F-box only protein 9 (FBXO9), an ubiquitination E3 ligase, has a functional role in adipocyte differentiation. Expression of FBXO9 was compared between obese mice and control lean mice using real-time PCR. Also, expression pattern of FBXO9 was monitored during 3T3-L1 adipocyte differentiation.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
November 2011
Thiazolidinediones (TZDs) are synthetic ligands of peroxisome proliferator-activated receptor-γ (PPARγ), a member of the nuclear receptor superfamily. TZDs are known to increase insulin sensitivity and also to have an antioxidative effect. In this study, we tested whether TZDs protect pancreatic β-cells from oxidative stress, and we investigated the mechanism involved in this process.
View Article and Find Full Text PDFActivation of the Wnt/β-catenin signaling pathway inhibits adipogenesis, while disruption of Wnt signaling leads to spontaneous adipogenesis. CCAAT/enhancer binding protein β (C/EBPβ) is rapidly induced in early stages of adipogenesis and is responsible for transcriptional induction of two major adipogenic transcription factors, peroxisome proliferator-activated receptor γ (PPARγ) and C/EBPα. In this study, we examined whether C/EBPβ is involved in the suppression of Wnt/β-catenin signaling during adipogenesis.
View Article and Find Full Text PDFBackground And Objectives: Hyperacute rejection (HAR) is a major obstacle to successful xenotransplantation of vascularized organs. This study was conducted to observe the effect of hemolysis of perfused human whole blood on pig heart function, and determine the major risk factors for preservation of xenoperfused cardiac function using ex-vivo pig to human xenogeneic cardiac perfusion model.
Materials And Methods: Harvested pig hearts were perfused with normal human whole blood (group 1), two different types of pre-treated human whole blood (group 2: immunoglobulins were depleted by plasmapheresis, group 3: pre-treated with plasmapheresis, GAS914, cobra venom factor (CVF) and steroid), and normal porcine whole blood as control (group 4) for 3 hours.
Objective: Having previously demonstrated that the complement system modulates mobilization of hematopoietic stem/progenitor cells (HSPC) in mice, we investigated the involvement of C5 cleavage fragments (C5a/(desArg)C5a) in human HSPC mobilization.
Materials And Methods: C5 cleavage fragments in the plasma were evaluated by enzyme-linked immunosorbent assay using human anti-(desArg)C5a antibody, and expression of the C5a/(desArg)C5a receptor (CD88) in hematopoietic cells by flow cytometry. We also examined the chemotactic responses of hematopoietic cells to C5 cleavage fragments and expression of stromal cell-derived factor-1 (SDF-1)-degrading proteases that perturb retention of HSPC in bone marrow, namely matrix metalloproteinase (MMP)-9, membrane type (MT) 1-MMP, and carboxypeptidase M.
Arch Immunol Ther Exp (Warsz)
September 2009
The mobilization of hematopoietic stem/progenitor cells (HSPCs) from bone marrow into peripheral blood (PB) is still not fully understood. Different chemokines, cytokines, growth factors, and neurotransmitters have been described that facilitate this process. However, mounting evidence suggests that mobilization of HSPCs is a part of the immune response and is mediated by innate immunity.
View Article and Find Full Text PDFBackground: Sertoli cells (SC) have immunomodulative properties, and chemokine receptor 7 (CCR7) can optimize the systemic immunomodulatory effect by guiding SC from the periphery to the secondary lymphoid organs.
Methods: The effect of immortalized neonatal porcine SC (NPSCi) was evaluated by analysis of cytokine levels. Hyporesponsiveness to donor cells was determined by MLC and analysis of splenocyte phenotypes using a murine allogeneic skin graft model.
The understanding of main mechanisms that determine the ability of immune privilege related to Sertoli cells (SCs) will provide clues for promoting a local tolerogenic environment. In this study, we evaluated the property of humoral and cellular immune response modulation provided by porcine SCs. Porcine SCs were resistant to human antibody and complement-mediated formation of the membrane attack complex (38.
View Article and Find Full Text PDFBackground: Sertoli cells (SC) are known to have active mechanism for evading humoral immune response and are known to have immune modulatory effects in the presence of other antigens. This has led us to hypothesize that systemic immune modulating effect of SC might be optimized by their residence on peripheral lymph node. This study was designed to evaluate our new strategy to promote preventive or therapeutic effects of SC in systemic immune modulation for organ transplantation.
View Article and Find Full Text PDFSertoli cells (SC) are known to contain immunoprotective properties, which allow them to survive as allografts without the use of immunosuppressive drugs. Experiments were designed to determine which factors are related to prolonged survival of allogeneic SC. Balb/c derived Sertoli (TM4) and colon cancer (CT-26) cell lines were implanted beneath the kidney capsule of non-immunosuppressed C57BL/6 mice and compared their survival as allografts.
View Article and Find Full Text PDFBackground: An understanding of the main mechanism that determines the ability of immune privilege related to Sertoli cells (SC) will provide clues for promoting a local tolerogenic environment. In this report, we established neonatal porcine SC line and evaluated their characteristics.
Methods: SC line was established following the transfection of primary SC (NPSC) from the testis of neonatal pig with plasmid pRNS-1 carrying genes for neomycin resistance and the SV40 large T antigen.
Background: The immunoprotective nature of the testes has prompted numerous investigations into their supportive roles during allogeneic or xenogeneic cellular grafts. However, the optimal developmental stage of these cells in terms of maximum efficacy for cellular grafts has not been elucidated. In this study, the time-dependent expressions of immune-privilege- and proliferation-related molecules in Sertoli cells were determined.
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