The ability to identify and isolate lineage-specific stem cells from adult tissues could facilitate cell replacement therapy. Leydig cells (LCs) are the primary source of androgen in the mammalian testis, and the prospective identification of stem Leydig cells (SLCs) may offer new opportunities for treating testosterone deficiency. Here, in a transgenic mouse model expressing GFP driven by the Nestin (Nes) promoter, we observed Nes-GFP+ cells located in the testicular interstitial compartment where SLCs normally reside. We showed that these Nes-GFP+ cells expressed LIFR and PDGFR-α, but not LC lineage markers. We further observed that these cells were capable of clonogenic self-renewal and extensive proliferation in vitro and could differentiate into neural or mesenchymal cell lineages, as well as LCs, with the ability to produce testosterone, under defined conditions. Moreover, when transplanted into the testes of LC-disrupted or aging models, the Nes-GFP+ cells colonized the interstitium and partially increased testosterone production, and then accelerated meiotic and post-meiotic germ cell recovery. In addition, we further demonstrated that CD51 might be a putative cell surface marker for SLCs, similar with Nestin. Taken together, these results suggest that Nes-GFP+ cells from the testis have the characteristics of SLCs, and our study would shed new light on developing stem cell replacement therapy for testosterone deficiency.

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BackgroundLiver fibrosis which mainly occurs upon chronic hepatitis virus infection potentially leads to portal hypertension, hepatic failure and hepatocellular carcinoma. However, the immune status of Th17 and Treg cells in liver fibrosis is controversial and the exact mechanisms remain largely elusive.MethodsLiver tissues and peripheral blood were obtained simultaneously from 32 hepatitis B virus infected patients undergoing surgery for hepatocellular carcinoma at the medical center of Sun Yat-sen University. Liver tissues at least 3 cm away from the tumor site were used for the analyses. Levels of Th17 cells and regulatory T cells were detected by flow cytometry analysis and immunohistochemistry. In vitro experiment, we adopted magnetic cell sorting to investigate how hepatic stellate cells regulate the levels of Th17 cells and regulatory T cells.ResultsWe found that hepatic Th17 cells and regulatory T cells were increased in patients with advanced stage HBV-related liver fibrosis. Hepatic stellate cells upregulated the levels of Th17 cells and regulatory T cells via PGE2/EP2 and EP4 pathway.ConclusionsWe found that the increased levels of Th17 cells and regulatory T cells were upregulated by hepatic stellate cells. These results may provide insight into the role of hepatic stellate cells and Th17 cells and regulatory T cells in the persistence of fibrosis and into the occurrence of hepatocellular carcinoma following cirrhosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-017-1167-y) contains supplementary material, which is available to authorized users.

Radiation-induced oral mucositis affects patient quality of life and reduces tolerance to cancer therapy. Unfortunately, traditional treatments are insufficient for the treatment of mucositis and might elicit severe side effects. Due to their immunomodulatory and anti-inflammatory properties, the transplantation of mesenchymal stem cells (MSCs) is a potential therapeutic strategy for mucositis. However, systemically infused MSCs rarely reach inflamed sites, impacting their clinical efficacy. Previous studies have demonstrated that chemokine axes play an important role in MSC targeting. By systematically evaluating the expression patterns of chemokines in radiation/chemical-induced oral mucositis, we found that CXCL2 was highly expressed, whereas cultured MSCs negligibly express the CXCL2 receptor CXCR2. Thus, we explored the potential therapeutic benefits of the transplantation of CXCR2-overexpressing MSCs (MSCsCXCR2) for mucositis treatment. Indeed, MSCsCXCR2 exhibited enhanced targeting ability to the inflamed mucosa in radiation/chemical-induced oral mucositis mouse models. Furthermore, we found that MSCCXCR2 transplantation accelerated ulcer healing by suppressing the production of pro-inflammatory chemokines and radiogenic reactive oxygen species (ROS). Altogether, these findings indicate that CXCR2 overexpression in MSCs accelerates ulcer healing, providing new insights into cell-based therapy for radiation/chemical-induced oral mucositis.