CD105 is regulated by hsa-miR-1287 and its expression is inversely correlated with osteopotential in SHED.

A more accurate understanding of the molecular mechanisms and signaling pathways underpinning human mesenchymal stem cell (MSC) plasticity and differentiation properties is pivotal for accomplishing solid and diligent translation of MSC-based experimental therapeutics and clinical trials to broad clinical practice. In addition, this knowledge enables selection of MSC subpopulations with increased differentiation potential and/or use of exogenous factors to boost this potential. Here, we report that CD105 (ENG) is a predictive biomarker of osteogenic potential in two types of MSCs: stem cells from human exfoliated deciduous teeth (SHED) and human adipose-derived stem cells (hASC). We also validate that CD105 can be used to select and enrich for subpopulations of SHED and hASC with higher in vitro osteogenic potential. In addition, we show that hsa-mir-1287 regulates CD105 expression, and propose that fine-tuning hsa-mir-1287 levels could be used to control osteopotential in SHED. These findings provide better discernment of the molecular bases behind MSC osteogenic plasticity and open up new perspectives to leverage osteogenic potential in MSCs by modulation of a specific miRNA.

A regulatory miRNA-mRNA network is associated with tissue repair induced by mesenchymal stromal cells in acute kidney injury

Mesenchymal stromal cells (MSCs) orchestrate tissue repair by releasing cell-derived microvesicles (MVs), which, presumably by small RNA species, modulate global gene expression. The knowledge of miRNA/mRNA signatures linked to a reparative status may elucidate some of the molecular events associated with MSC protection. Here, we used a model of cisplatin-induced kidney injury (acute kidney injury) to assess how MSCs or MVs could restore tissue function. MSCs and MVs presented similar protective effects, which were evidenced in vivo and in vitro by modulating apoptosis, inflammation, oxidative stress, and a set of prosurvival molecules. In addition, we observed that miRNAs (i.e., miR-880, miR-141, miR-377, and miR-21) were modulated, thereby showing active participation on regenerative process. Subsequently, we identified that MSC regulates a particular miRNA subset which mRNA targets are associated with Wnt/TGF-beta fibrosis, and epithelial-mesenchymal transition signaling pathways. Our results suggest that MSCs release MVs that transcriptionally reprogram injured cells, thereby modulating a specific miRNA-mRNA network.

Chronic VEGF blockade worsens glomerular injury in the remnant kidney model.

VEGF inhibition can promote renal vascular and parenchymal injury, causing proteinuria, hypertension and thrombotic microangiopathy. The mechanisms underlying these side effects are unclear. We investigated the renal effects of the administration, during 45 days, of sunitinib (Su), a VEGF receptor inhibitor, to rats with 5/6 renal ablation (Nx). Adult male Munich-Wistar rats were distributed among groups S+V, sham-operated rats receiving vehicle only; S+Su, S rats given Su, 4 mg/kg/day; Nx+V, Nx rats receiving V; and Nx+Su, Nx rats receiving Su. Su caused no change in Group S. Seven and 45 days after renal ablation, renal cortical interstitium was expanded, in association with rarefaction of peritubular capillaries. Su did not worsen hypertension, proteinuria or interstitial expansion, nor did it affect capillary rarefaction, suggesting little angiogenic activity in this model. Nx animals exhibited glomerulosclerosis (GS), which was aggravated by Su. This effect could not be explained by podocyte damage, nor could it be ascribed to tuft hypertrophy or hyperplasia. GS may have derived from organization of capillary microthrombi, frequently observed in Group Nx+Su. Treatment with Su did not reduce the fractional glomerular endothelial area, suggesting functional rather than structural cell injury. Chronic VEGF inhibition has little effect on normal rats, but can affect glomerular endothelium when renal damage is already present.