ABSTRACT
BACKGROUND:Platelet-rich plasma has been shown to enhance the viability and the pro-angiogenesis capacity of mesenchymal stem cells.Extracellular vesicles are one of the key mediators for mesenchymal stem cells to exert their effects,but currently,it is unclear whether platelet-rich plasma affects the functions of extracellular vesicles. OBJECTIVE:To investigate the effects of platelet-rich plasma on the function of extracellular vesicles from bone marrow mesenchymal stem cells,verify whether platelet-rich plasma can be used as an adjuvant to enhance the healing effects of bone marrow mesenchymal stem cells on repairing the peripheral nerve injury. METHODS:For in vitro study,bone marrow mesenchymal stem cells were cultured under normal conditions and with 1%platelet-rich plasma.The ultracentrifugation was used to extract the extracellular vesicles produced by bone marrow mesenchymal stem cells cultured under normal conditions(EVs-nor)or the condition supplemented with 1%platelet-rich plasma(EVs-prp).Extracellular vesicles were used to incubate with Schwann cells.The EdU assay,western blot assay,qPCR and light microscopy photography were performed to examine the effects of EVs-nor and EVs-prp on Schwann cell reprogramming,which was characterized by cell proliferation,c-Jun expression,reprogramming-associated gene expression and cell morphology.For in vivo study,the model of sciatic nerve injury in rats was established.Bone marrow mesenchymal stem cells were grafted with or without 1%platelet-rich plasma into the injured rat sciatic nerve using a chitin nerve conduit.Eight weeks after the surgery,the recovery was assessed by histological and functional indexes,including regenerated nerve fiber density,gastrocnemius wet weight ratio and sciatic function index. RESULTS AND CONCLUSION:(1)Compared with EVs-nor,EVs-prp was stronger in promoting Schwann cell proliferation.The gene expressions of c-Jun and GDNF were significantly upregulated in EVs-prp treated Schwann cells.The morphology of Schwann cells was significantly longer in EVs-prp group than that in EVs-nor group,indicating that EVs-prp had a stronger ability to stimulate Schwann cell reprogramming than EVs-nor.(2)Sciatic nerve injury animal experiment results revealed that grafting mesenchymal stem cells along with platelet-rich plasma into the injured sciatic nerve showed the best recovery compared with grafting mesenchymal stem cells or platelet-rich plasma alone,demonstrated by the significantly improved density of nerve fibers,gastrocnemius wet weight ratio,and sciatic function index.(3)These results suggested that platelet-rich plasma improved the function of bone marrow mesenchymal stem cell-derived extracellular vesicles and could be served as a practical and feasible preparation to synergize with bone marrow mesenchymal stem cells to improve peripheral nerve repair.
ABSTRACT
Objective@#To evaluate the effects of percutaneous nephrolithotomy (PNL) in the treatment of medullary sponge kidney with calculi.@*Methods@#A total of 77 patients (91 renal units) of medullary sponge kidney with calculi (MSK group) and 77 patients (77 renal units) with common kidney stone (control group) received PNL at Department of Urology in Peking University People′s Hospital from September 2006 to February 2016 were analyzed retrospectively. The MSK group included 33 males and 44 females with a mean age of (42.1±13.2) years, the mean stone burden was (3.9±1.8) cm. The control group included 36 males and 41 females with a mean age of (45.3±13.0) years, the mean stone burden was (3.6±1.5) cm. The numbers of tracts, the time of operation, the drop of hemoglobin, the change of creatine, the time of hospitalization, the stone free rate and major complications were compared between the two groups. The measurement data and numeration data were compared with t test and χ2 test.@*Results@#There were no significant differences in sex, age, preoperative urinary tract infection, stone type, and stone burden between the two groups (all P>0.05). The proportion of bilateral renal calculus in MSK group was higher (18.2% vs. 0, χ2=15.400, P=0.000). There were 159 percutaneous channels were established in MSK group while 90 percutaneous channels were established in control group. Compared with the control group, the operation time ((88.1±37.5) minutes vs. (68.5±30.1) minutes, t=3.543, P=0.000) and hospitalization time ((15.1±8.3) days vs. (10.1±3.6) days, t=4.816, P=0.000) were longer, the creatinine level increased ((101.2±62.6) μmol/L vs. (71.3±23.6) μmol/L, t=3.777, P=0.000), the rate of stone free decreased (27.5% vs. 83.1%, χ2=51.840, P=0.000) and the rate of complications increased (29.9% vs. 11.7%, χ2=8.114, P=0.004) in MSK group. There was no statistically difference in hemoglobin drop ((12.5±13.2) g/L vs. (13.0±10.9) g/L, t=-0.260, P=0.795).@*Conclusions@#Using PNL for patients of MSK with calculi has a lower stone free rate and a higher complications. It is an effective method for patients of MSK with large and complex calculi.