No abstract

Hypoxia preconditioning has been confirmed as an effective strategy to enhance the therapeutic potentials of mesenchymal stem cells (MSCs), such as for myocardial ischemia. However, whether hypoxia preconditioning would produce beneficial effects on MSC-based renal repair has not been demonstrated. In the study, we aimed to determine the feasibility and efficacy of hypoxia preconditioning to enhance MSC-based therapy of acute kidney injury (AKI). MSCs were isolated from human adipose tissues. The paracrine effects of MSCs under normoxia and hypoxia were determined in vitro. Rats of AKI were induced by kidney I/R surgery and randomly divided into three groups: I/R control receiving PBS injection; MSC group receiving normal MSC injection; hypoMSC group receiving hypoxia-preconditioned MSC injection. It was demonstrated in vitro that paracrine effects of MSCs were significantly enhanced, especially angiogenic factors. Dihydroethidium (DHE) staining showed that antioxidative activities of MSCs were significantly enhanced by hypoxia stimulation. Vascularization, apoptosis, and histological injury were all significantly improved in hypoMSC injected group compared with that in control and MSC injected groups. Finally, the renal function was also significantly improved in hypoMSC injected group compared with that in the other two groups as assessed by the serum creatinine and BUN levels.

In plants, the vesicle fusion process plays a vital role in pathogen defence. However, the importance of the vesicle fusion process in apple ring rot has not been studied. Here, we isolated and characterised the apple syntaxin gene MdSYP121. Silencing the MdSYP121 gene in transgenic apple calli increased tolerance to Botryosphaeria dothidea infection; this increased tolerance was correlated with salicylic acid (SA) synthesis-related and signalling-related gene transcription. In contrast, overexpressing MdSYP121 in apple calli resulted in the opposite phenotypes. In addition, the results of RNA sequencing (RNA-Seq) and quantitative real-time PCR (qRT-PCR) assays suggested that MdSYP121 plays an important role in responses to oxidation–reduction reactions. Silencing MdSYP121 in apple calli enhanced the expression levels of reactive oxygen species (ROS)-related genes and the activity of ROS-related enzymes. The enhanced defence response status in MdSYP121-RNAi lines suggests that syntaxins are involved in the defence response to B. dothidea. More importantly, we showed that MdSYP121 forms a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex with MdSNAP33, and the complex may participate in regulating resistance to B. dothidea. In conclusion, by regulating the interaction of SA pathway and oxidation–reduction process, MdSYP121 can influence the pathogen infection process in apple.

The differentiation rate of adipose-derived mesenchymal stem cells (Ad-MSCs) into endothelial cells is always lower under normal condition, which limits further clinical application of Ad-MSCs for angiogenesis regenerative medicine and needs to be enhanced. In the present study, the tissue-specific-derived decellularized ovine arteries matrix (DCS) was used as scaffold to investigate the pro-endothelial differentiation ability of decellularized ovine arteries matrix as well as the underlying mechanisms. The prepared decellularized ovine arteries matrix by the combination of enzymatic and chemical decellularization approaches preserved macroscopic 3D architecture, native composition and ultrastructure of natural ovine arteries. The RT-PCR, histopathological and immunofluorescence assay results suggested that DCS could increase the proliferation ability of MSC. What's more, the DCS could also induce the endothelial differentiation of MSC, which was further enhanced by adding VEGF. Our results showed that natural 3D matrix from decellularized ovine arteries could induce the endothelial differentiation of AD-MSCs alone or with the combination of VEGF. Our results indicated that the decellularized ovine arteries matrix would serve as an efficient culture system for promoting endothelial differentiation of Ad-MSCs.

Central venous catheters (CVC) are widely used in clinics to gain vascular access, but the risk and prevalence of catheter-related complications remains a serious issue. We report a long-term dialysis catheter accidentally inserted into the mediastinum via the right jugular vein in a hemodialysis patient. We also review complications associated with vascular catheterization and propose immediate therapeutic interventions for such cases.