The mechanisms of control of glucagon secretion are largely debated. In particular, the paracrine role of somatostatin (SST) is unclear. We studied its role in the control of glucagon secretion by glucose and K channel blockers, using perifused islets and the in situ perfused pancreas. The involvement of SST was evaluated by comparing glucagon release of control tissue or tissue without paracrine influence of SST (pertussis toxin-treated islets, or islets or pancreas from mice). We show that removal of the paracrine influence of SST suppresses the ability of K channel blockers or K channel ablation to inhibit glucagon release, suggesting that in control islets, the glucagonostatic effect of K channel blockers/ablation is fully mediated by SST. By contrast, the glucagonostatic effect of glucose in control islets is mainly independent of SST for low glucose concentrations (0-7 mmol/L) but starts to involve SST for high concentrations of the sugar (15-30 mmol/L). This demonstrates that the glucagonostatic effect of glucose only partially depends on SST. Real-time quantitative PCR and pharmacological experiments indicate that the glucagonostatic effect of SST is mediated by two types of SST receptors, SSTR2 and SSTR3. These results suggest that alterations of the paracrine influence of SST will affect glucagon release.

Hepcidin is a key hormone governing mammalian iron homeostasis and may be directly or indirectly involved in the development of most iron deficiency/overload and inflammation-induced anemia. The objective of this study was to investigate the expression of hepcidin in anemia of chronic disease. To characterize serum hepcidin, iron and inflammatory indicators associated with anemia of chronic disease (ACD), we studied ACD, ACD concomitant iron-deficiency anemia (ACD/IDA), pure IDA and acute inflammation (AcI) patients and analyzed the associations between hepcidin levels and inflammation parameters in various types of anemia. Serum hepcidin levels in patient groups were statistically different, from high to low: ACD, AcI > ACD/IDA > the control > IDA. Serum ferritin levels were significantly increased in ACD and AcI patients but were decreased significantly in ACD/IDA and IDA. Elevated serum EPO concentrations were found in ACD, ACD/IDA and IDA patients but not in AcI patients and the controls. A positive correlation between hepcidin and IL-6 levels only existed in ACD/IDA, AcI and the control groups. A positive correlation between hepcidin and ferritin was marked in the control group, while a negative correlation between hepcidin and ferritin was noted in IDA. The significant negative correlation between hepcidin expression and reticulocyte count was marked in both ACD/IDA and IDA groups. All of these data demonstrated that hepcidin might play role in pathogenesis of ACD, ACD/IDA and IDA, and it could be a potential marker for detection and differentiation of these anemias.

Mesenchymal stem cell (MSC) differentiation is dramatically reduced after long-term in vitro culture, which limits their application. MSCs derived from induced pluripotent stem cells (iPSCs-MSCs) represent a novel source of MSCs. In this study, we investigated the therapeutic effect of iPSC-MSCs on diabetic mice. Streptozocin-induced diabetic mice transplanted with 400 islets alone or with 1 · 10 6 iPSC-MSCs were examined following rapamycin injection (0.1 mg/kg/day, i.p., from days 0 to 9) after transplantation. Our results showed that iPSC-MSCs combined with rapamycin significantly prolonged islet allograft survival in the diabetic mice; 50% of recipients exhibited long-term survival ( > 100 days). Histopathological analysis revealed that iPSCMSCs combined with rapamycin preserved the graft effectively, inhibited inflammatory cell infiltration, and resulted in substantial release of insulin. Flow cytometry results showed that the proportion of CD4 + and CD8 + T cells was significantly reduced, and the number of T regulatory cells increased in the spleen and lymph nodes in the iPSC-MSCs combined with the rapamycin group compared with the rapamycin-alone group. Production of the Th1 proinflammatory cytokines interleukin-2 (IL-2) and interferon-g was reduced, and secretion of the anti-inflammatory cytokines IL-10 and transforming growth factor-b was enhanced compared with the rapamycin group, as determined using enzyme-linked immunosorbent assays. Transwell separation significantly weakened the immunosuppressive effects of iPSC-MSCs on the proliferation of Con A-treated splenic T cells, which indicated that the combined treatment exerted immunosuppressive effects through cell-cell contact and regulation of cytokine production. Taken together, these findings highlight the potential application of iPSCMSCs in islet transplantation.

Activation of TLR7 and TLR9 by endogenous RNA- or DNA-containing ligands, respectively, can lead to hyper-activation of immune cells, including macrophages and DCs, subsequently contributes to the pathogenesis of SLE. CD180, a TLR-like protein, is specifically involved in the development and activation of immune cells. Our previous study and others have reported that CD180-negative B cells are dramatically increased in SLE patients and responsible for the production of auto-antibodies. However, the mode of CD180 expression on macrophages and DCs in SLE remains unclear and the role of CD180 on regulating TLR7- and TLR9-mediated activation of macrophages and DCs are largely unknown. In the present study, we found that the percentages of CD180-negative macrophages and DCs were both increased in SLE patients and lupus-prone MRL/lpr mice compared with healthy donors and wild-type mice, respectively. Notably, ligation of CD180 significantly inhibited the activation of TLR7 and TLR9 signaling pathways in macrophages and DCs through the Lyn-SHP-1/2 axis. What's more, injection of anti-CD180 Ab could markedly ameliorate the lupus-symptoms of imiquimod-treated mice and lupus-prone MRL/lpr mice through inhibiting the activation of macrophages and DCs. Collectively, our results highlight a critical role of CD180 in regulating TLR7- and TLR9-mediated activation of macrophages and DCs, hinting that CD180 can be regarded as a potential therapeutic target for SLE treatment.

Mesenchymal stem cells (MSCs) have been widely used in regenerative medicine and cellular therapy due to their multi-lineage differentiation potential and immunomodulatory function. The applicability of MSCs also depends on their cellular sources and in vivo functions. Here in this study, we systematically compared the morphologic characteristics, immunophenotypes and the adipogenic differentiation of MSCs derived from umbilical cord (UC), adipose tissue (Ad) and bone marrow (BM). We found that the three tissues-derived MSCs displayed decreased adipogenic capacity in the order: Ad-MSC > BM-MSC > UC-MSC, and no morphologic and immunophenotypic differences were observed. Mechanistic investigation revealed a miR-301b~miR-130b—PPARγ axis, whose expression pattern in UC-MSC, Ad-MSC and BM-MSC significantly correlates with their adipogenic capacity. Our results come up with a potential mechanism to elucidate the differential adipogenesis of Ad-MSC, BM-MSC and UC-MSC, which would provide instructional advice for which source of MSCs to choose according to a certain clinical purpose. Furthermore, the miR-301b~miR-130b—PPARγ axis may also be used as a potential therapeutic target for the disorders associated with MSCs-mediated abnormal adipogenesis.

Arsenic trioxide may prevent allograft rejection by inhibiting T-cell proliferation and inducing T-cell apoptosis.

The aim of this study was to establish the antioxidant status and oxidative stress in adult patients with chronic idiopathic thrombocytopenic purpura (ITP). Eighty-four patients diagnosed with chronic ITP were studied. Fiftyeight age-matched healthy subjects were selected as controls. Serum nitrogen monoxide ( NO), oxidized glutathione (GSSG), malondialdehyde (MDA), total antioxidant status (TAS), total oxidant status (TOS), superoxide dismutase (SOD), hydrogen peroxide enzyme (CAT), glutathione peroxidase (GSH-Px), glutathione (GSH) were evaluated by enzyme-linked immunosorbent assay (ELISA). It was found that serum SOD, CAT, GSH-Px, GSH, TAS levels were significantly lower in patients with chronic ITP than controls (all P < 0.05), while serum NO, GSSG, MDA, TOS values were significantly higher (P < 0.05). The number of platelet showed a negative correlation with NO, GSSG, MDA, TOS, respectively,while platelet number showed a positive correlation with SOD, CAT, GSH-Px, GSH, TAS. These findings suggested that oxidants were increased and antioxidants were decreased in patients with chronic ITP, these may be prominent factors in destructing the platelet membrane. The scavenging of oxygen radical provides a theoretical basis for the treatment of ITP patients.

Increased propensity of bone marrow-derived mesenchymal stem cells (BM-MSCs) toward adipogenic differentiation has been implicated in the fatty bone marrow and defective hematopoiesis of aplastic anemia (AA). However, the underlying molecular mechanism remains to be investigated. In this study, we found that microRNA 199a-5p (miR-199a-5p) exhibits significantly higher expression in AA BM-MSCs compared with the normal control and is demonstrated to facilitate adipogenic differentiation of BM-MSCs through lentivirus-mediated miR-199a overexpression. Mechanistic investigation reveals that miR-199a-5p could be regulated by PPAR gamma (PPARg) in a transcription-independent manner and regulates adipogenic differentiation by targeting the expression of transforming growth factor beta induced (TGFBI), which is subsequently validated as a negative regulator of adipogenesis. Besides, the positive correlation between PPARg and miR-199a-5p expression as well as the inverse relationship between miR-199a-5p and TGFBI expression in normal and AA BM-MSCs was observed. Altogether, our work demonstrates that PPARg-regulated miR-199a-5p promotes adipogenesis of BM-MSCs by inhibiting TGFBI expression, which might be a novel mechanism underlying the bone marrow adiposity in AA, and provides promising therapeutic targets for AA treatment.