Isolation and multipotential differentiation of mesenchymal stromal cell­like progenitor cells from human bladder.

Various types of mesenchymal stromal cells (MSCs) have been used in urological tissue engineering but to date the existence of MSCs has not been reported in the human bladder. The present study provided evidence that a small number of MSC­like cells exist in the human bladder and designated this class of cells 'human bladder­derived MSC­like cells' (hBSCs). It was demonstrated that hBSCs can be cultured to yield a large population. These hBSCs expressed the surface markers of MSCs and exhibited the capacity for osteogenic, adipogenic and chondrogenic differentiation. On induction with appropriate media in vitro, hBSCs could differentiate into bladder­associated cell types, including urothelial, endothelial and smooth muscle cell­like lineages. In addition, the average telomerase activity of adult hBSCs was higher compared with adult human bone marrow­derived MSCs, but lower than that of human umbilical cord Wharton's jelly­derived MSCs. These findings may inspire future studies on the role of hBSCs in urological tissue engineering applications and in other fields.

Overexpression of ULK1 Represents a Potential Diagnostic Marker for Clear Cell Renal Carcinoma and the Antitumor Effects of SBI-0206965.

BACKGROUND: Uncoordinated 51-like kinase 1 (ULK1) plays a vital role in autophagy. ULK1 dysregulation has recently been found in several human cancers. METHODS: mRNA expression levels of ULK1 and clinical information were analysed from The Cancer Genome Atlas data. ULK1 expression levels were verified in 36 paired fresh ccRCC tissue specimens by western blot analysis. Expression of ULK1 was knockdown by shRNA lentivirus. ULK1 activity was inhibited by SBI-0206965. The effect of inhibition of ULK1 was measured by detecting the apoptotic rate, autophagy, and the ratio of ROS and NADPH. The efficacy of SBI-0206965 in vivo was assessed by the murine xenograft model. FINDINGS: ULK1 mRNA expression was significantly upregulated in clear cell renal cell carcinoma (ccRCC) and overexpression of ULK1 correlated with poor outcomes. We found that ULK1 was highly expressed in 66.7% of ccRCC tumours (p < 0·05). Knockdown of ULK1 and selective inhibition of ULK1 by SBI-0206965 induced cell apoptosis in ccRCC cells. We demonstrated that SBI-0206965 triggered apoptosis by preventing autophagy and pentose phosphate pathway (PPP) flux. Furthermore, blocking the kinase activity of ULK1 with SBI-0206965 resulted in a level of anticancer effect in vivo. INTERPRETATION: Taken together, our results suggested that ULK1 was upregulated in ccRCC tumours and may be a potential therapeutic target. Therefore, SBI-0206965 should be further considered as an anti-ccRCC agent. FUND: This work was supported in part by The National Natural Science Foundation of China (No. 81570748) and Natural Science Foundation of Fujian Province (No. 2018J01345, 2017XQ1194).

Correlation of CDC42 Activity with Cell Proliferation and Palmitate-Mediated Cell Death in Human Umbilical Cord Wharton's Jelly Derived Mesenchymal Stromal Cells.

RHO GTPases regulate cell migration, cell-cycle progression, and cell survival in response to extracellular stimuli. However, the regulatory effects of RHO GTPases in mesenchymal stromal cells (MSCs) are unclear. Herein, we show that CDC42 acts as an essential factor in regulating cell proliferation and also takes part in lipotoxic effects of palmitate in human umbilical cord Wharton's jelly derived MSCs (hWJ-MSCs). Cultured human bone marrow, adipose tissue, and hWJ-MSC derived cells had varying pro-inflammatory cytokine secretion levels and cell death rates when treated by palmitate. Strikingly, the proliferation rate of these types of MSCs correlated with their sensitivity to palmitate. A glutathione-S-transferase pull-down assay demonstrated that hWJ-MSCs had the highest activation of CDC42, which was increased by palmitate treatment in a time-dependent manner. We demonstrated that palmitate-induced synthesis of pro-inflammatory cytokines and cell death was attenuated by shRNA against CDC42. In CDC42 depleted hWJ-MSCs, population-doubling levels were notably decreased, and phosphorylation of ERK1/2 and p38 MAPK was reduced. Our data therefore suggest a mechanistic role for CDC42 activity in hWJ-MSC proliferation and identified CDC42 activity as a promising pharmacological target for ameliorating lipotoxic cell dysfunction and death.

[Palmitate induces apoptosis and endoplasmic reticulum stress in human umbilical cord-derived mesenchymal stem cells].

The saturated free fatty acid (FFA), palmitate, could induce apoptosis in various cell types, but little is known about its effects on human umbilical cord-derived mesenchymal stem cells (hUC-MSCs). Here, we investigated whether palmitate induced apoptosis and endoplasmic reticulum (ER) stress in hUC-MSCs. hUC-MSCs were stained by labeled antibodies and identified by flow cytometry. After administration with palmitate, apoptotic cell was assessed by flow cytometry using the Annexin V-FITC/7-AAD apoptosis detection kit. Relative spliced XBP1 levels were analyzed using semi-quantitative RT-PCR. The mRNA of BiP, GRP94, ATF4 and CHOP were analyzed by real-time PCR. Relative BiP and CHOP protein were analyzed using Western blot analysis. The results showed that hUC-MSCs were homogeneously positive for MSC markers; palmitate increased apoptosis of hUC-MSCs and activated XBP1 splicing, BiP, GRP94, ATF4 and CHOP transcription. These findings suggest that palmitate induces apoptosis and ER stress in hUC-MSCs.

BMSCs reduce rat granulosa cell apoptosis induced by cisplatin and perimenopause.

BACKGROUND: The objective of this study was to evaluate the effect of bone marrow mesenchymal stem cells (BMSCs) on the apoptosis of granulosa cells (GCs) in rats. RESULTS: Cisplatin increased GC apoptosis from 0.59% to 13.04% in the control and cisplatin treatment groups, respectively, which was significantly reduced upon co-culture with BMSCs to 4.84%. Cisplatin treatment increased p21 and bax and decreased c-myc mRNA expression, which was reversed upon co-culture with BMSCs. As compared to young rats, increased apoptosis was observed in the perimenopausal rats (P < 0.001). After 3 months, the apoptosis rate in the BMSC group was significantly lower than that of the control group (P = 0.007). CONCLUSIONS: BMSC therapy may protect against GC apoptosis induced by cisplatin and perimenopause. Further studies are necessary to evaluate therapeutic efficacy of BMSCs.