C-terminus of Hsc70-interacting protein (CHIP) enhances stemness properties of human Wharton’s jelly mesenchymal stem cell

Mesenchymal stem cells are an attractive source of multipotent cells in part because they are easy to obtain. Several E3 ligases regulate the stability and functions of various factors in different adult stem cells through the ubiquitylation pathway. We investigated the C-terminus of Hsc70-interacting protein (CHIP) E3 ligase that regulates pluripotency of human Wharton’s jelly mesenchymal stem cells (hWJMSC). We found that CHIP increases protein kinase B (Akt) phosphorylation by decreased expression of phosphatase and tensin homolog (PTEN), which suggests improvement of the survival pathway by CHIP over-expression. We also found that increased CHIP expression induced Sox2 and NANOG, which can promote stem cell self-renewal and prevent oxidative stress-induced senescence of hWJMSC by decreased p21. We found that CHIP could be used to enhance the multiple functions of hWJMSC.     

Hyperglycemia differentially affects proliferation,apoptosis, and BNIP3 and p53 mRNA expression of human umbilical cord Wharton's jelly cells from non-diabetic and diabetic pregnancies

Diabetes in pregnancy constitutes an unfavorable environment for embryonic and fetal development, where the child has a higher risk of perinatal morbidity and mortality, with high incidence of congenital malformations and predisposition to long-term metabolic diseases that increase with a hypercaloric diet. To analyze whether hyperglycemia differentially affects proliferation, apoptosis, and mRNA expression in cells from children of normoglycemic pregnancies (NGPs) and diabetes mellitus pregnancies (DMPs), we used umbilical cord Wharton jelly cells as a research model. Proliferation assays were performed to analyze growth and determine the doubling time, and the rate of apoptosis was determined by flow cytometry-annexin-V assays. AMPK, BNIP3, HIF1α, and p53 mRNA gene expression was assessed by semi-quantitative RT-PCR. We found that hyperglycemia decreased proliferation in a statistically significant manner in NGP cells treated with 40?mM D-glucose and in DMP cells treated with 30 and 40?mM D-glucose. Apoptosis increased in hyperglycemic conditions in NGP and DMP cells. mRNA expression of BNIP3 and p53 was significantly increased in cells from DMPs but not in cells from NGPs. We found evidence that maternal irregular metabolic conditions, like diabetes with hyperglycemia in culture, affect biological properties of fetal cells. These observations could be a constituent of fetal programming.     

Scaffold-free 3D culturing enhance pluripotency,immunomodulatory factors,and differentiation potential of Wharton’s jelly-mesenchymal stem cells

Mesenchymal stem cells (MSCs) show a decline in pluripotency and differentiation with increased cell culture passages in 2D cultures. The 2D monolayer culture fails to correctly imitate the architecture and microenvironments of in-vivo cell models. Alternatively, 3D culture may improve the simulations of in-vivo cell microenvironments with wide applications in cell culture and drug discovery. In the present study, we compared various 3D culturing techniques such as 3D micro-well (3D-S), hanging drop (HD), and ultra-low attachment (ULA) plate-based spheroid culture to study their effect on morphology, viability, pluripotency, cell surface markers, immunomodulatory factors, and differentiation capabilities of Wharton’s jelly-mesenchymal stem cells (WJ-MSCs). The cell morphology, viability, and senescence of 3D cultured WJ-MSCs were comparable to cells in 2D culture. The expression of pluripotency markers (OCT4, SOX2, and NANOG) was enhanced upto 2–8 fold in 3D cultured WJ-MSCs when compared to 2D culture. Moreover, the immunomodulatory factors (IDO, IL-10, LIF, ANG1, and VEGF) were significantly elevated in ULA based 3D cultured WJ-MSCs. Furthermore, significant enhancement in the differentiation potential of WJ-MSCs towards adipocyte (ADP and C/EBP-α), osteocyte (OPN and RUNX2), and definitive endodermal (SOX17, FOXA2, and CXCR4) lineages in 3D culture conditions were observed. Additionally, the osteogenic and adipogenic differentiation potential of WJ-MSCs over the time points 7 days, 14 days, and 28 days was also significantly increased in 3D culture groups. Our study demonstrates that stemness properties of WJ-MSCs were significantly enhanced in 3D cultures and ULA-based culture outperformed other methods with high pluripotency gene expression and enhanced differentiation potential. This study indicates the efficacy of 3D cultures to bridge the gap between 2D cell culture and animal models in regenerative medicine.     

脐带华通胶间充质干细胞向Flkl阳性细胞分化的研究

目的：诱导脐带华通胶间充质干细胞向Flk1阳性细胞分化。方法：胶原酶法分离培养脐带华通胶间充质干细胞,第3代细胞以含2-巯基乙醇的分化培养基培养,应用RT-PCR和流式细胞仪从mRNA和蛋白水平检测Flk1阳性细胞分化水平。结果：脐带华通胶间充质干细胞Flk1mRNA及蛋白表达极低,分化培养基培养后表达上调,48h达高峰（P〈0.05）,之后表达降低。结论：2-巯基乙醇可诱导脐带华通胶间充质干细胞向Flk1阳性细胞分化,为从中分选Flk1阳性细胞进行进一步研究提供了依据     

人脐带间充质干细胞对低氧环境下的肾小管上皮细胞中肝细胞生长因子（HGF）表达的影响

目的：肾脏的急性缺血缺氧性损伤是泌尿外科常见病,以肾小管间质纤维化为主要病理特点,成体干细胞在急性肾脏损伤动物模型中可以促进肾脏结构修复、改善肾脏功能,肝细胞生长因子作为抗纤维化的主要生长因子,在成体干细胞干预的急性肾脏损伤动物模型实验中起重要作用,然而以往的研究对象主要以动物模型为主,成体干细胞对肝细胞生长因子的具体调节机制尚不清。本实验通过体外分离、培养人的脐带间充质干细胞,来干预离体低氧预处理后的大鼠近端肾小管上皮细胞,探讨在体外培养条件下人脐带间充质干细胞对低氧预处理大鼠近端肾小管上皮细胞肝细胞生长因子表达的影响,为今后研究间充质干细胞治疗肾功能损害提供可靠的理论依据。方法：采用贴壁培养的方法无菌条件下分离、培养、传代人脐带间充质干细胞。细胞融合达90％时更换无血清培养基（serum．fleemedium,SFM）培养24h,收集细胞上清液即为人脐带间充质干细胞条件培养基（conditionmedium,CM）;大鼠近端肾小管上皮细胞（tubularepithelialcells,TECs）于低氧环境处理1h后,随机分为对照组与CM干预组,分别培养24h和48h后检测TECs中大鼠肝细胞生长因子（hepatocytegrowthfactor,HGF）的mRNA水平、收集上清液测定大鼠HGF蛋白的含量,同时收集CM干预组中Oh,12h、24h、48h的上清液,测定其中人来源HGF蛋白的含量,并对TECs在CM干预24h和48h后行免疫组化定性人的HGF蛋白的表达。结果：在低氧预处理的培养环境下,CM干预组中,TECs中大鼠来源的HGFmRNA表达水平在24h和48h时明显高于对照组（P〈0．05）;上清液中大鼠HGF蛋白的含量在24h和48h,CM干预组显著高于对照组（P〈0．05）;上清液中人的HGF蛋白的含量随时间进行性增高,免疫组化染色显示在24h和48h大鼠TECs中能检测人的HGF蛋白的表达。结论：在低氧预处理的体外培养环境下,脐带间充质干细胞的条件培养基可以显著的上调大鼠自身的HGF水平,并可诱导大鼠TECs合成和分泌人的HGF蛋白,并为探究脐带间充质干细胞治疗肾功能损害提供可靠的理论依据。     

Histological,immunohistochemical, and genomic evaluation of excisional and diabetic wounds treated with human Wharton’s jelly stem cells with and without a nanocarrier

We showed in previous studies that human umbilical cord Wharton’s jelly stem cells (hWJSCs) improved the healing rates of excisional and diabetic wounds in the mouse model. As an extension of those studies, we report here the more detailed quantitative histological, immunohistochemical, and genomic evaluation of biopsies from those excisional and diabetic wounds in an attempt to understand the mechanisms of the enhanced wound healing aided by hWJSCs. Bright-field microscopic observations and ImageJ software analysis on histological sections of the excisional and diabetic wound biopsies collected at different time points showed that the thickness of the epidermis and dermis, and positive picrosirius-red stained areas for collagen, were significantly greater in the presence of hWJSCs compared with controls (P < 0.05). Immunohistochemistry of the diabetic wound biopsies showed increased positive staining for the vascular endothelial marker CD31 and cell proliferation marker Ki67 in the presence of hWJSCs and its conditioned medium (hWJSC-CM). Quantitative real-time polymerase chain reaction showed upregulation of groups of genes involved in extracellular matrix regulation, collagen biosynthesis, angiogenesis, antifibrosis, granulation, and immunomodulation in the presence of hWJSCs. Taken together, the results demonstrated that hWJSCs and hWJSC-CM that contains the paracrine secretions of hWJSCs, enhance the healing of excisional and diabetic wounds via re-epithelialization, collagen deposition, angiogenesis, and immunomodulation. The inclusion of an Aloe vera-polycaprolactone (AV/PCL) nanocarrier did not significantly change the effect of the hWJSCs. However, the topical application of an AV/PCL nanocarrier impregnated with hWJSCs is convenient and less invasive than the administration of hWJSC injections into wounds.     

脐带华通胶间充质干细胞向Flk1 阳性细胞分化的研究*

目的:诱导脐带华通胶间充质干细胞向Flk1阳性细胞分化。方法:胶原酶法分离培养脐带华通胶间充质干细胞,第3代细胞以含2-巯基乙醇的分化培养基培养,应用RT-PCR和流式细胞仪从mRNA和蛋白水平检测Flk1阳性细胞分化水平。结果:脐带华通胶间充质干细胞Flk1mRNA及蛋白表达极低,分化培养基培养后表达上调,48h达高峰(P<0.05),之后表达降低。结论:2-巯基乙醇可诱导脐带华通胶间充质干细胞向Flk1阳性细胞分化,为从中分选Flk1阳性细胞进行进一步研究提供了依据。