No abstract

Rationale Endothelial progenitor cells (EPCs) respond to SDF-1 through receptors CXCR7 and CXCR4. Whether SDF-1 receptors involves in diabetes induced EPCs dysfunction remains unknown. Objective To determine the role of SDF-1 receptors in diabetic EPCs dysfunction. Methods and Results CXCR7 expression, but not CXCR4 was reduced in EPCs from db/db mice, which coincided with impaired tube formation. Knockdown of CXCR7 impaired tube formation of EPCs from normal mice, while up-regulation of CXCR7 rescued angiogenic function of EPCs from db/db mice. In normal EPCs treated with oxidized low-density lipoprotein (ox-LDL) or high glucose (HG) also reduced CXCR7 expression, impaired tube formation and increased oxidative stress and apoptosis. The damaging effects of ox-LDL or HG were markedly reduced by SDF-1 pretreatment in EPCs transduced with CXCR7 lentivirus (CXCR7-EPCs) but not in EPCs transduced with control lentivirus (Null-EPCs). Most importantly, CXCR7-EPCs were superior to Null-EPCs for therapy of ischemic limbs in db/db mice. Mechanistic studies demonstrated that ox-LDL or HG inhibited Akt and GSK-3β phosphorylation, nuclear export of Fyn and nuclear localization of Nrf2, blunting Nrf2 downstream target genes HO-1, NQO-1 and catalase, and inducing an increase in EPC oxidative stress. This destructive cascade was blocked by SDF-1 treatment in CXCR7-EPCs. Furthermore, inhibition of PI3K/Akt prevented SDF-1/CXCR7-mediated Nrf2 activation and blocked angiogenic repair. Moreover, Nrf2 knockdown almost completely abolished the protective effects of SDF-1/CXCR7 on EPC function in vitro and in vivo. Conclusions Elevated expression of CXCR7 enhances EPC resistance to diabetes-induced oxidative damage and improves therapeutic efficacy of EPCs in treating diabetic limb ischemia. The benefits of CXCR7 are mediated predominantly by an Akt/GSK-3β/Fyn pathway via increased activity of Nrf2.

BackgroundHuman adipose stem cells (ASCs) have emerged as a promising treatment paradigm for skin wounds. Recent works demonstrate that the therapeutic effect of stem cells is partially mediated by extracellular vesicles, which comprise exosomes and microvesicles. In this study, we investigate the regenerative effects of isolated microvesicles from ASCs and evaluate the mechanisms how ASC microvesicles promote wound healing.MethodsAdipose stem cell-derived microvesicles (ASC-MVs) were isolated by differential ultracentrifugation, stained by PKH26, and characterized by electron microscopy and dynamic light scattering (DLS). We examined ASC-MV effects on proliferation, migration, and angiogenesis of keratinocytes, fibroblasts, and endothelial cells both in vitro and in vivo. Next, we explored the underlying mechanisms by gene expression analysis and the activation levels of AKT and ERK signaling pathways in all three kinds of cells after ASC-MV stimulation. We then assessed the effect of ASC-MVs on collagen deposition, neovascularization, and re-epithelialization in an in vivo skin injury model.ResultsASC-MVs could be readily internalized by human umbilical vein endothelial cells (HUVECs), HaCAT, and fibroblasts and significantly promoted the proliferation, migration, and angiogenesis of these cells both in vitro and in vivo. The gene expression of proliferative markers (cyclin D1, cyclin D2, cyclin A1, cyclin A2) and growth factors (VEGFA, PDGFA, EGF, FGF2) was significantly upregulated after ASC-MV treatment. Importantly, ASC-MVs stimulated the activation of AKT and ERK signaling pathways in those cells. The local injection of ASC-MVs at wound sites significantly increased the re-epithelialization, collagen deposition, and neovascularization and led to accelerated wound closure.ConclusionsOur data suggest that ASC-MVs can stimulate HUVEC, HaCAT, and fibroblast functions. ASC-MV therapy significantly accelerates wound healing, and the benefits of ASC-MVs may due to the involvement of AKT and ERK signaling pathways. This illustrates the therapeutic potential of ASC-MVs which may become a novel treatment paradigm for cutaneous wound healing.Electronic supplementary materialThe online version of this article (10.1186/s13287-019-1152-x) contains supplementary material, which is available to authorized users.

CXC chemokine receptor 3 (CXCR3), predominately expressed on memory/activated T lymphocytes, is a receptor for both IFN-γ-inducible protein-10 (γ IP-10) and monokine induced by IFN-γ (Mig). We report a novel finding that CXCR3 is also expressed on eosinophils. γ IP-10 and Mig induce eosinophil chemotaxis via CXCR3, as documented by the fact that anti-CXCR3 mAb blocks γ IP-10- and Mig-induced eosinophil chemotaxis. γ IP-10- and Mig-induced eosinophil chemotaxis are up- and down-regulated by IL-2 and IL-10, respectively. Correspondingly, CXCR3 protein and mRNA expressions in eosinophils are up- and down-regulated by IL-2 and IL-10, respectively, as detected using flow cytometry, immunocytochemical assay, and a real-time quantitative RT-PCR technique. γ IP-10 and Mig act eosinophils to induce chemotaxis via the cAMP-dependent protein kinase A signaling pathways. The fact that γ IP-10 and Mig induce an increase in intracellular calcium in eosinophils confirms that CXCR3 exists on eosinophils. Besides induction to chemotaxis, γ IP-10 and Mig also activate eosinophils to eosinophil cationic protein release. These results indicate that CXCR3-γ IP-10 and -Mig receptor-ligand pairs as well as the effects of IL-2 and IL-10 on them may be especially important in the cytokine/chemokine environment for the pathophysiologic events of allergic inflammation, including initiation, progression, and termination in the processes.

No abstract

We report that CCR3 is not expressed on freshly isolated peripheral and germinal B cells, but is up-regulated after stimulation with IL-2 and IL-4 (∼98% CCR3+). Ligation of CCR3 by eotaxin/chemokine ligand (CCL) 11 induces apoptosis in IL-2- and IL-4-stimulated primary CD19+ (∼40% apoptotic cells) B cell cultures as well as B cell lines, but has no effect on chemotaxis or cell adhesion. Freshly isolated B cells express low levels of CD95 and CD95 ligand (CD95L) (19 and 21%, respectively). Expression is up-regulated on culture in the presence of a combination of IL-2, IL-4, and eotaxin/CCL11 (88% CD95 and 84% CD95L). We therefore propose that ligation of such newly induced CCR3 on peripheral and germinal B cells by eotaxin/CCL11 leads to the enhanced levels of CD95 and CD95L expression. Ligation of CD95 by its CD95L expressed on neigboring B cells triggers relevant death signaling pathways, which include an increase in levels of Bcl-2 expression, its functional activity, and the release of cytochrome c from the mitochondria into the cytosol. These events initiate a cascade of enzymatic processes of the caspase family, culminating in programmed cell death. Interaction between CCR3 and eotaxin/CCL11 may, besides promoting allergic reactions, drive activated B cells to apoptosis, thereby reducing levels of Ig production, including IgE, and consequently limit the development of the humoral immune response. The apoptotic action of eotaxin/CCL11 suggests a therapeutic modality in the treatment of B cell lymphoma.

Every sector of the global economy is faced with environmental problems and their resulting consequences to their day-to-day operations. Due to the rising threat of global climate change, the green banking (GB) concept has been given significant attention in recent green finance literature. Therefore, the main purpose of this study was to identify the impact of GB practices on banks’ environmental performance and sources of green financing of private commercial banks (PCBs) in Bangladesh. Using a survey method, the primary data were obtained from a cross-sectional sample of 322 banking employees of PCBs in Bangladesh. In order to identify the key relationships existing between the study variables, structural equation modelling (SEM) approach was employed. The empirical findings indicated that banks’ employees, daily-operations, and policy-related GB practices have significant positive effects on green financing, contrary to banks’ customer-related GB practice, which was not statistically significant. Additionally, banks’ green project financing exhibited a strong and positive influence on banks’ environmental performance. Moreover, banks’ daily operation and policy-related practices of GB were observed to have significant impacts on banks’ environmental performances, in contrast to banks’ employee and customer-related GB practices. Therefore, major policy implications and directions for future research in the concerned area are discussed.

Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) is a complicated syndrome characterized by genitourinary pain in the absence of bacterial infection. Th17 cell‐driven autoimmunity has been proposed as a cause of CP/CPPS. However, the factors that promote Th17‐driven autoimmunity in experimental autoimmune prostatitis (EAP) and the molecular mechanisms are still largely unknown. Here, we showed that Th17 cells were excessively activated, and blockade of IL‐17A could effectively ameliorate various symptoms in EAP. Furthermore, we revealed that calcium/calmodulin‐dependent kinase Ⅳ (CaMK4), especially Thr196 p‐CaMK4 was increased in the Th17 cells of the EAP group, which were activated by intracellular cytosolic Ca2+. Pharmacologic and genetic inhibition of CaMK4 decreased the proportion of Th17 cells, and the protein and mRNA level of IL‐17A, IL‐22, and RORγt. The phosphorylation of CaMK4 was dependent on the increase in intracellular cytosolic Ca2+ concentration in Th17 cells. A mechanistic study demonstrated that inhibition of CaMK4 reduced IL‐17A production by decreasing the phosphorylation of Akt‐mTOR, which was well accepted to positively regulate Th17 differentiation. Collectively, our results demonstrated that Ca2+‐CaMK4‐Akt/mTOR‐IL‐17A axis inhibition may serve as a promising therapeutic strategy for CP/CPPS.