Search

In normal physiological conditions, restoration of a functional epidermal barrier is highly efficient; nevertheless, when it fails, one of the main consequences is a chronic ulcerative skin defect, one of the most frequently recognized complications of diabetes. Most of these chronic venous ulcers do not heal with conventional treatment, leading to the appearance of infections and complications in the patient. Treatments based on the use of autologous mesenchymal stem cells (MSC) have been successful; however, its implementation entails complications. The umbilical cord offers an unlimited source of adult MSC (ucMSC) from the Wharton's jelly tissue with the same relevant features for clinical applicability and avoiding difficulties. It has recently been characterized by one specific subpopulation derived from ucMSC, the differentiated mesenchymal cells (DMCs). This subpopulation expresses the human leukocyte antigen-G (HLA-G) molecule, a strong immunosuppressive checkpoint, and vascular endothelial growth factor (VEGF), the most potent angiogenic factor. Considering the importance of developing a more effective therapy for wound treatment, especially ulcerative skin lesions, we analyzed DMC safety, efficacy, and therapeutic potential. By immunohistochemistry, umbilical cords HLA-G and VEGF positive were selected. Flow cytometry revealed that 90% of the DMC subpopulation are HLA-G+, CD44+, CD73+, CD29+, CD105+, CD90+, and HLA-DR-. Reverse transcription-polymerase chain reaction revealed the expression of HLA-G in all of DMC subpopulations. Upon co-culture with the DMC, peripheral blood mononuclear cell proliferation was inhibited by 50%. In a xenograft transplantation assay, DMC improved wound healing with no signs of rejection of the transplanted cells in immunocompetent mice. This study confirms that HLA-G allows allogeneic cell transplantation, and VEGF is fundamental for the restoration of the failure in blood supply. DMC population has positive effects on wound healing by promoting local angiogenesis in skin lesions. DMC could play a very important role in regenerative medicine and could be a novel allogeneic cell-therapeutic tool for wound healing.

Background: Clear cell renal cell carcinoma (ccRCC), the most aggressive renal cancer, is characterized by early lymph node metastases and bad prognosis. Most therapies targeting advanced or metastatic ccRCC are based, as first-line treatment, on the administration of the vascular endothelial growth factor (VEGF) neutralizing antibody termed Bevacizumab. Despite proven benefits, the expected results were not obtained for the majority of patients. The possibility that an intricate interplay between angiogenesis and immune-checkpoints might exist lead us to evaluate tumor angiogenesis, by means of VEGF expression together with the immune checkpoint HLA-G/ILT4., Methods: Tumor specimens were obtained from patients from two separate cohorts: One from "Evita Pueblo" Hospital from Berazategui, (Buenos Aires, Argentina) and the second includes patients surgically operated at the Urology Department of Saint-Louis Hospital (Paris, France) with a confirmed ccRCC diagnosis. Immunohistochemistry was performed with specific antibodies directed against HLA-G, VEGF-A, VEGF-C, D240, CD34, ILT4 and Ca-IX. In addition, gene expression levels were measured in a cell line derived from a ccRCC patient by semi-quantitative RT-PCR., Results: Our results show that the highly vascularized tumors of ccRCC patients express high levels of VEGF and the immune-checkpoint HLA-G. In addition, ILT4, one of the HLA-G receptors, was detected on macrophages surrounding tumor cells, suggesting the generation of an immune-tolerant microenvironment that might favor tumorigenesis. Notably, RT-qPCR analysis provided the first evidence on the transcriptional relationship between HLA-G/ILT4 and the VEGF family. Namely, in the presence of HLA-G or ILT4, the levels of VEGF-A are diminished whereas those of VEGF-C are increased., Conclusions: In an effort to find new therapeutic molecules and fight against metastasis dissemination associated with the poor survival rates of ccRCC patients, these findings provide the rationale for co-targeting angiogenesis and the immune checkpoint HLA-G.

Introduction: Mesenchymal stem cells (MSCs) are a promising source of cells for regenerative therapies. Although they can be isolated easily from several tissues, cell expansion is limited since their properties are lost with successive passages. Hence, pluripotent derived MSCs (PD-MSCs) arise as a suitable alternative for MSC production. Nevertheless, at present, PD-MSC derivation protocols are either expensive or not suitable for clinical purposes., Methods: In this work we present a therapy-grade, inexpensive and simple protocol to derive MSCs from pluripotent stem cells (PSCs) based on the use of platelet lysate (PL) as medium supplement., Results: We showed that the PD-MSCPL expressed multiple MSC markers, including CD90, CD73, CD105, CD166, and CD271, among others. These cells also show multilineage differentiation ability and immunomodulatory effects on pre-stimulated lymphocytes. Thorough characterization of these cells showed that a PD-MSCPL resembles an umbilical cord (UC) MSC and differs from a PSC in surface marker and extracellular matrix proteins and integrin expression. Moreover, the OCT-4 promoter is re-methylated with mesenchymal differentiation comparable with the methylation levels of UC-MSCs and fibroblasts. Lastly, the use of PL-supplemented medium generates significantly more MSCs than the use of fetal bovine serum., Conclusions: This protocol can be used to generate a large amount of PD-MSCs with low cost and is compatible with clinical therapies.

We have previously demonstrated that the sub-chronic administration of low doses of Toc or α-Toc, glyphosate and zineb to rats (i.p. 1/250 LD50, three times a week for 5 weeks) provoked severe oxidative stress (OS) in testicles. These effects were also reflected in plasma. Lipoic acid (LA) and α-tocopherol are considered as antioxidants due to their ability to neutralize reactive oxygenated species (ROS) and reset endogenous antioxidant levels. To investigate the possible protective effect on reproductive function, LA and Toc (i.p. 25, 50 and 100mg/kg) were administered simultaneously with the pesticide mixture (PM) for 5 weeks. Both drugs prevented OS and the damage to proteins and lipids caused by PM in a dose-dependent manner. The PM-induced increase levels of prostaglandins E2 and F2α was completely restored by LA but not by Toc. Similarly, only LA was able to restore the inhibition of testosterone production, the decrease of 3β- and 17β-hydroxysteroid dehydrogenases activities, and the elevation of gonatropins (FSH and LH) levels produced by PM. Furthermore, LA was more efficient than Toc in normalizing the histological alterations produced by PM administration, suggesting that pesticides act though other mechanisms that generate oxidative stress. In our experimental model LA displayed a higher protective role against pesticide-induced damage than that observed by Toc administration. Our results suggest that LA administration is a promising therapeutic strategy for coping with disorders suspected to be caused by OS generators - such as pesticides - in male reproductive system., (Copyright © 2013 Elsevier Inc. All rights reserved.)