Salidroside Pretreatment to Mesenchymal Stem Cells Improves Cell Survival and Migration to Promote Diabetic Wound Healing

Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokines and angiogenic factors,mesenchymal stem cells(MSCs)have been acknowledged to be a potential agent in modulating wound healing process.However,post-transplanted MSCs are vulnerable to death,indicating poor survival and migration ability in the wound site of the host,especially under hyperglycemia.As hyperglycemia induces reactive oxygen species(ROS)generation and cellular apoptosis,improvement of MSCs survival and migration potentials under hyperglycemia could contribute to a more efficient MSCs-based wound healing therapy.Salidroside(Sa),a small-molecule drug derived from Rhodiola plant,has been proved to enhance the paracrine function of skeletal muscle cells,as well as their migration even under hypoxichyperglycemia.Herein,we investigated whether Sa could improve the survival and migration potentials of MSCs,subsequently enhance the wound healing process under hyperglycemia.Methods MSCs were cultured under three conditions:low glucose,high glucose,and high glucose+Sa.qPCR analysis and western blotting were done to examine the mRNA and protein expression level of several factors which are important in upregulating the wound healing process.MTT colorimetric assay,intracellular ROS detection,and flow cytometry assay were employed to examine the effect of Sa in MSCs survival.Transwell chamber assay,scratch assay,and phalloidin staining were done to elucidate the role of Sa in regulating MSCs migration potential.For in vivo experiment,diabetic wound healing mice model was generated to elucidate the effect of Sa-pretreated MSCs transplantation in wound closure rate,as well as re-epithelization status,observed with hematoxylin and eosin staining.The diabetic wound healing mice model were divided into three groups:1)mice injected with PBS,2)mice transplanted with PBS-pretreated MSCs,and 3)mice transplanted with Sa-pretreated MSCs.Results(1)Hyperglycemic condition induced the generation of ROS and suppressed total cell number of MSCs,while Sa treatment into MSCs restored these hyperglycemia-induced alterations.In line with this,total apoptotic cells were also suppressed by treating MSCs with Sa.The expression level of cell survival factor,heme-oxygenase 1(HO-1),was enhanced in Sa-pretreated MSCs.Further treatment of HO-1 inhibitor into Sa-pretreated MSCs nullified the ROS level and total apoptotic cells,indica-ting the importance of HO-1 in mediating the Sa-induced survival of MSCs under hyperglycemia.(2)Transwell chamber and scratch assay results showed that Sa-pretreated MSCs have a higher migration potential under hyperglycemia,supported by higher F-actin polymerization fractal dimension.Fibroblast growth factor 2(FGF2)and hepatocyte growth factor(HGF)expression level,which are essential factors for cell migration,were also improved in Sa-pretreated MSCs under hyperglycemia.(3)In diabetic wound healing mice model,transplantation of Sa-pretreated MSCs resulted in significantly improved wound closure rate and re-epithelization.The protein levels of HO-1,FGF2,and HGF were also enhanced in the tissues obtained from the wound site of diabetic wound healing mice model which were transplanted with Sa-pretreated MSCs.Conclusions Salidroside pretreatment on MSCs could improve their survival and migration potentials,subsequently promoting wound healing process under hyperglycemia.This prospective MSC-based therapy could serve as a novel strategy to improve diabetic wound healing.

The two sides of chromosomal instability:drivers and brakes in cancer

Chromosomal instability(CIN)is a hallmark of cancer and is associated with tumor cell malignancy.CIN triggers a chain reaction in cells leading to chromosomal abnormalities,including deviations from the normal chromosome number or structural changes in chromosomes.CIN arises from errors in DNA replication and chromosome segregation during cell division,leading to the formation of cells with abnormal number and/or structure of chromosomes.Errors in DNA replication result from abnormal replication licensing as well as replication stress,such as double-strand breaks and stalled replication forks;meanwhile,errors in chromosome segregation stem from defects in chromosome segregation machinery,including centrosome amplification,erroneous microtubule-kinetochore attachments,spindle assembly checkpoint,or defective sister chromatids cohesion.In normal cells,CiN is deleterious and is associated with DNA damage,proteotoxic stress,metabolic alteration,cell cycle arrest,and senescence.Paradoxically,despite these negative consequences,CiN is one of the hallmarks of cancer found in over 90%of solid tumors and in blood cancers.Furthermore,CiN could endow tumors with enhanced adaptation capabilities due to increased intratumor heterogeneity,thereby facilitating adaptive resistance to therapies;however,excessive CiN could induce tumor cells death,leading to the"just-right"model for CIN in tumors.Elucidating the complex nature of CIN is crucial for understanding the dynamics of tumorigenesis and for developing effective anti-tumor treatments.This review provides an overview of causes and consequences of CIN,as well as the paradox of CIN,a phenomenon that continues to perplex researchers.Finally,this review explores the potential of CIN-based anti-tumor therapy.