Bone marrow-derived mesenchymal stem cells differentiation into tubular epithelial-like cells in vitro

Differentiated kidney tubular cell-derived extracellular vesicles enhance maturation of tubuloids

The prevalence of end-stage kidney disease (ESKD) is rapidly increasing with the need for regenerative therapies. Adult stem cell derived kidney tubuloids have the potential to functionally mimic the adult kidney tubule, but still lack the expression of important transport proteins needed for waste removal. Here, we investigated the potential of extracellular vesicles (EVs) obtained from matured kidney tubular epithelial cells to modulate in vitro tubuloids functional maturation. We focused on organic anion transporter 1 (OAT1), one of the most important proteins involved in endogenous waste excretion. First, we show that EVs from engineered proximal tubule cells increased the expression of several transcription factors and epithelial transporters, resulting in improved OAT1 transport capacity. Next, a more in-depth proteomic data analysis showed that EVs can trigger various biological pathways, including mesenchymal-to-epithelial transition, which is crucial in the tubular epithelial maturation. Moreover, we demonstrated that the combination of EVs and tubuloid-derived cells can be used as part of a bioartificial kidney to generate a tight polarized epithelial monolayer with formation of dense cilia structures. In conclusion, EVs from kidney tubular epithelial cells can phenotypically improve in vitro tubuloid maturation, thereby enhancing their potential as functional units in regenerative or renal replacement therapies.

Differentiation of Bone Mesenchymal Stem Cells Into Vascular Endothelial Cell-Like Cells Using Functionalized Single-Walled Carbon Nanotubes

Carbon nanotubes (CNTs) are a promising bioactive scaffold for bone regeneration because of their superior mechanical and biological properties. Vascularization is crucial in bone tissue engineering, and insufficient vascularization is a long-standing problem in tissue-engineered scaffolds. However, the effect of CNTs on vascularization is still minimal. In the current study, pristine single-walled carbon nanotubes (SWNTs) were purified to prepare different ratios of SWNTs/EDC composites, and their surface morphology and physicochemical properties of SWNTs/EDC were studied. Furthermore, the effect of SWNTs/EDC on vascularization was investigated by inducing the differentiation of bone mesenchymal stem cells (BMSCs) into vascular endothelial cell-like cells (VEC-like cells). Results showed that SWNTs/EDC composite was successfully prepared, and EDC was embedded in the SWNTs matrix and uniformly distributed throughout the composites. The AFM, FTIR spectra, and Raman results confirmed the formation of SWNTs/EDC composites. Besides, the surface topography of the SWNTs/EDC composites presents a rough surface, which may positively affect cell function. In vitro cell culture revealed that SWNTs and SWNTs/EDC composites exhibited excellent biocompatibility and bioactivity. The SWNTs/EDC composite at mass/volume ratios 1:10 had the best enhancement of proliferation and differentiation of BMSCs. Moreover, after culture with SWNTs/EDC composite, approximately 78.3% ± 4.2% of cultured cells are double-positive for FITC-UEA-1 and DiI-Ac-LDL double staining. Additionally, the RNA expression of representative endothelial cell markers VEGF, VEGF-R2, CD31, and vWF in the SWNTs/EDC composite group was significantly higher than those in the control and SWNTs group. With the limitation of our study, the results suggested that SWNTs/EDC composite can promote BMSCs differentiation into VEC-like cells and positively affect angiogenesis and bone regeneration.

Influence of hepatocyte growth factor-transfected bone marrow-derived mesenchymal stem cells towards renal fibrosis in rats

Background & objectives:

Hepatocyte growth factor (HGF) produced by endothelial cells, fibroblasts, fat cells and other interstitial cells, can promote angiogenesis, repair damaged tissues and resist fibrosis. Mesenchymal stem cells (MSCs) are located in bone marrow and secrete a variety of cytokines and are often used in the repair and regeneration of damaged tissues. This study was aimed to investigate the influence of HGF-transfected bone marrow-derived MSCs towards renal fibrosis in rats.

Methods:

The HGF gene-carrying adenoviral vector (Ad-HGF) was transfected into MSCs, and the Ad-HGF-modified MSCs were transplanted into rats with unilateral ureteral obstruction (UUO). The localization of renal transplanted cells in the frozen section was observed with fluorescence microscope. The Masson's trichrome staining was performed to observe the renal collagen deposition, and the immunohistochemistry was performed to detect the expressions of α-smooth muscle actin (α-SMA) and HGF in renal tissues. Reverse transcription (RT)-PCR was used to detect the mRNA expressions of α-SMA, HGF and fibronectin (FN).

Results:

Ad-HGF-modified MSCs could highly express HGF in vitro. On the post-transplantation 3^rd, 7^th and 14^th day, the 4',6-diamidino-2-phenylindole (DAP)-labelled transplanted cells were seen inside renal tissues. Compared with UUO group, the renal collagen deposition in transplantation group was significantly reduced, and the expressions of α-SMA mRNA and protein were significantly decreased, while the expressions of HGF mRNA and protein were significantly increased, and the expression of FN mRNA was significantly decreased (P<0.001).

Interpretation & conclusions:

Trans-renal artery injection of HGF-modified MSCs can effectively reduce the renal interstitial fibrosis in UUO rat model.

Knockdown of Tcf3 enhances the wound healing effect of bone marrow mesenchymal stem cells in rats

The aim of the present study was to explore the wound healing effect of Tcf3 in rat bone marrow mesenchymal stem cells (BMSCs) and their effects on wound healing. Epidermal growth factor (EGF) and fibroblast growth factors (FGFs) were used to induce BMSCs differentiation into epithelial-like cells. Western Blotting analysis and RT-qPCR were performed to assess the expression levels of Tcf3 and the markers of epithelial-like cells, such as Cytokeratin-18 (CK-18), CK-19 and P63. Cell counting kit-8 (CCK-8) and clone formation assay were carried out to detect cell viability. Immunohistochemistry and HE staining were used to assess the level of Tcf3 protein and skin repair degree, respectively. Rat wound healing model was built to evaluate the effects of BMSCs with altered expression of Tcf3 on wound healing. Results showed that EGF and FGFs stimulation increased the expression of CK-18, CK-19 and P63, improved BMSCs viability, but decreased the expression of Tcf3. Knockdown of Tcf3 in BMSCs increased CK-18, CK-19 and P63 expression and improved cell proliferation, as well as accelerated wound healing process. Moreover, inhibition of Wnt/β-catenin signaling weakened the effect of Tcf3 down-regulation on BMSCs proliferation enhancement. And inhibition of Notch1 signaling impeded the epithelial-like cell differentiation of BMSCs induced by Tcf3 down-regulation. Our study reveals that knockdown of Tcf3 enhances the wound healing process of BMSCs in rat, which provides new approach for accelerating skin regeneration.

In Vitro Expression of Cytokeratin 19 in Adipose-Derived Stem Cells Is Induced by Epidermal Growth Factor

BACKGROUND Cytokeratin 19 (CK19) is a typical epithelial marker. In this study, we determined whether epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) could enhance CK19 expression in adipose-derived stem cells (ADSCs), thereby inducing the differentiation of ADSCs into epithelial-like cells. MATERIAL AND METHODS ADSCs were isolated from perinephric fat, and the expression of CD29, CD90, and CD105 was confirmed. Following isolation, ADSCs were cultured in static medium or medium containing EGF or bFGF. RESULTS Flow cytometry revealed that EGF and bFGF could alter mesenchymal stem cell markers as well as the cell cycle of ADSCs. Western blotting and immunofluorescence revealed that after 14 days, EGF treatment enhanced the expression of CK19 in ADSCs. CONCLUSIONS Our findings offer important insight for the clinical use of ADSCs in the generation of epithelial-like cells in the future.

Mesenchymal Stromal Cells Epithelial Transition Induced by Renal Tubular Cells-Derived Extracellular Vesicles

Mesenchymal-epithelial interactions play an important role in renal tubular morphogenesis and in maintaining the structure of the kidney. The aim of this study was to investigate whether extracellular vesicles (EVs) produced by human renal proximal tubular epithelial cells (RPTECs) may induce mesenchymal-epithelial transition of bone marrow-derived mesenchymal stromal cells (MSCs). To test this hypothesis, we characterized the phenotype and the RNA content of EVs and we evaluated the in vitro uptake and activity of EVs on MSCs. MicroRNA (miRNA) analysis suggested the possible implication of the miR-200 family carried by EVs in the epithelial commitment of MSCs. Bone marrow-derived MSCs were incubated with EVs, or RPTEC-derived total conditioned medium, or conditioned medium depleted of EVs. As a positive control, MSCs were co-cultured in a transwell system with RPTECs. Epithelial commitment of MSCs was assessed by real time PCR and by immunofluorescence analysis of cellular expression of specific mesenchymal and epithelial markers. After one week of incubation with EVs and total conditioned medium, we observed mesenchymal-epithelial transition in MSCs. Stimulation with conditioned medium depleted of EVs did not induce any change in mesenchymal and epithelial gene expression. Since EVs were found to contain the miR-200 family, we transfected MSCs using synthetic miR-200 mimics. After one week of transfection, mesenchymal-epithelial transition was induced in MSCs. In conclusion, miR-200 carrying EVs released from RPTECs induce the epithelial commitment of MSCs that may contribute to their regenerative potential. Based on experiments of MSC transfection with miR-200 mimics, we suggested that the miR-200 family may be involved in mesenchymal-epithelial transition of MSCs.

In vitro expression of cytokeratin 18, 19 and tube formation of adipose-derived stem cells induced by the breast epithelial cell line HBL-100

Fat transplantation is increasingly used in breast augmentation; and recently, the issue of safety concerns from a cellular and molecular point of view has been raised. In this study, attentions were paid to the interaction between adipose-derived stem cells (ADSC) and mammary epithelial cells: human breast cancer cell line - 100 (HBL - 100) cells were used to simulate the normal microenvironment in breast tissue, ADSCs were harvest from human and co-cultured with HBL-100 cells. It was found that ADSCs formed tube-like structures in the co-culture with HBL-100 cells in contrast to the normal morphology of ADSCs in the control group. In addition, the immunofluorescence imaging showed that cytokeratin 18 and 19 (CK18 and 19) were significantly expressed in ADSCs after the co-culture with HBL-100 cells. The ultrastructure of those ADSCs also showed epithelial changes. In conclusion, ADSCs are not biological stable when co-cultured with HBL-100 cells. They differentiate into epithelial-like cells with the expression of epithelial surface marks (CK 18, 19) and form tube-like structures. This may offer an important evidence for the further study of clinical application of transplanting ADSCs rich adipose tissue into the breast in the future.

Enhanced renoprotective effect of HIF-1α modified human adipose-derived stem cells on cisplatin-induced acute kidney injury in vivo

Current therapeutic options for acute kidney injury (AKI) are limited to the use of supportive measures and dialysis. A recent approach that has sparked great interest and gained enormous popularity is the implantation of stem cells to repair acutely damaged kidney organ. Hypoxia inducible factor-1α (HIF-1α) is effective in protecting the kidney from ischemia and nephrotoxicity. In this study, we investigated whether HIF-1α-modified adipose-derived stem cells (ASCs) had an enhanced protective effect on cisplatin-induced kidney injury in vivo. Cisplatin-induced AKI was established in nude mice. Our study demonstrated that HIF-1α-modified ASCs obviously promoted the recovery of renal function, ameliorated the extent of histologic injury and reduced renal apoptosis and inflammation, but HIF-1α-modified ASCs homed to kidney tissues at very low levels after transplantation. In addition, we also found that HIF-1α-modified ASCs significantly increased HO-1 expression in cisplatin-induced AKI in vivo. Thus, our study indicated HIF-1α-modified ASCs implantation could provide advanced benefits in the protection again AKI, which will contribute to developing a new therapeutic strategy for the treatment of AKI.

Bone marrow-derived mesenchymal stem cells protect against cisplatin-induced acute kidney injury in rats by inhibiting cell apoptosis

Acute kidney injury (AKI) is a common syndrome with a high mortality and morbidity rate. Recent developments in stem cell research have shown great promise for the treatment of AKI. The aim of this study was to investigate the therapeutic potential and anti-apoptotic mechanisms of action of bone marrow-derived mesenchymal stem cells (BM-MSCs) in the treatment of AKI induced by cisplatin in vivo and in vitro. In vivo, adult male Sprague-Dawley rats (n=24) were administered BM-MSCs intravenously one day after cisplatin injection. The rats were sacrificed four days after the cisplatin injection and the effects of BM-MSCs on cisplatin-induced AKI, as well as the anti-apoptotic mechanisms involved were investigated. In vitro, NRK-52E cells, a rat renal proximal tubular cell line, were incubated in conditioned medium or complete medium in the presence or absence of cisplatin, followed by cell proliferation and apoptosis assays. The infusion of BM-MSCs preserved renal function, ameliorated renal tubular lesions, reduced apoptosis and accelerated tubular cell regeneration in the rats with cisplatin-induced AKI. The infusion of BM-MSCs also inhibited the activation of two mitogen-activated protein kinases, p38 and ERK, downregulated the expression of Bax and cleaved caspase-3, and upregulated the expression of Bcl-2. BM-MSC-conditioned medium improved NRK-52E cell viability and inhibited apoptosis. In conclusion, our results demonstrate that injecting rats with BM-MSCs protects renal function and structure in cisplatin-induced AKI by inhibiting cell apoptosis in vivo. BM-MSC-conditioned medium protects renal cells from apoptosis induced by cisplatin in vitro. Hence, the infusion of BM-MSCs should be considered as a possible therapeutic strategy for the treatment of AKI.

Generating CK19-positive cells with hair-like structures from Wharton's jelly mesenchymal stromal cells

Wharton's jelly mesenchymal stromal cells (WJMSCs) are considered mesenchymal, multipotent, and capable of differentiating into cells of mesodermal origin. Ectodermal differentiation from mesenchymal cells has been recently reported. Herein, we show for the first time that we can generate cytokeratin 19-positive cells and hair-like structures from WJMSCs in vitro using 2 separate methodologies that utilize osteogenic media to induce WJMSCs to undergo osteogenic differentiation. In one method, WJMSCs were seeded on a matrix isolated from Wharton's jelly following decellularization. In the other method, WJMSCs were cultured to form spheroids. Our findings demonstrate that WJMSCs may have the capacity for ectodermal differentiation.