Polydatin protects Schwann cells from methylglyoxal induced cytotoxicity and promotes crushed sciatic nerves regeneration of diabetic rats.

Oxidative stress plays the main role in the pathogenesis of diabetes mellitus and peripheral neuropathy. Polydatin (PD) has been shown to exhibit strong antioxidative and antiinflammatory effects. At present, no research has focused on the possible effects of PD on Schwann cells and impaired peripheral nerves in diabetic models. Here, we used an in vitro Schwann cell damage model induced by methylglyoxal and an in vivo diabetic sciatic nerve crush model to study problems in such an area. In our experiment, we demonstrated that PD potently alleviated the decrease of cellular viability, prevented reactive oxygen species generation, and suppressed mitochondrial depolarization as well as cellular apoptosis in damaged Schwann cells. Moreover, we found that PD could upregulate Nrf2 and Glyoxalase 1 (GLO1) expression and inhibit Keap1 and receptor of AGEs (RAGE) expression of damaged Schwann cells. Finally, our in vivo experiment showed that PD could promote sciatic nerves repair of diabetic rats. Our results revealed that PD exhibited prominent neuroprotective effects on Schwann cells and sciatic nerves in diabetic models. The molecular mechanisms were associated with activating Nfr2 and GLO1 and inhibiting Keap1 and RAGE.

Grafted muscle-derived stem cells promote the therapeutic efficiency of epimysium conduits in mice with peripheral nerve gap injury.

Our research aimed to build allogeneic artificial conduits with epimysium and muscle-derived stem cells (MDSCs) from the skeletal muscle of mice. We applied the conduit to repair peripheral nerve defects and estimated the effectiveness of the repair process. In the research, we prepared epimysium conduits with lumens to bridge repair a 5-mm-long sciatic nerve defect from C57 wild-type mice and then transplanted green fluorescent protein (GFP)-MDSCs and Matrigel suspensions into the conduit. Histological and functional assessments were performed 4 and 8 weeks after surgery. The tissue-engineered conduit from muscle effectively repaired the nerve defect, while the group with GFP-MDSCs showed improved histological examinations and functional assessments, and the newborn nerves highly expressed GFP. As the results suggested, autologous epimysium conduits represent a reliable method to repair peripheral nerve defects, and the addition of MDSCs promote the effectiveness of differentiating into multiple lineages. Our research simultaneously demonstrated the myogenic, neurogenic, and angiogenic potential of MDSCs in vivo for the first time.

A modified preplate technique for efficient isolation and proliferation of mice muscle-derived stem cells.

We modified an existing protocol to develop a more efficient method to acquire and culture muscle-derived stem cells (MDSCs) and compared the characteristics of cells obtained from the two methods. This method is based on currently used multistep enzymatic digestion and preplate technique. During the replating process, we replaced the traditional medium with isolation medium to promote fibroblast-like cell adherence at initial replating step, which shortened the purifying duration by up to 4 days. Moreover, we modified the culture container to provide a stable microenvironment that promotes MDSC adherence. We compared the cell morphology, growth curve and the expression of specific markers (Sca-1, CD34, PAX7 and Desmin) between the two cell groups separately obtained from the two methods. Afterwards, we compared the neural differentiation capacity of MDSCs with other muscle-derived cell lineages. The protocol developed here is a fast and effective method to harvest and purify MDSCs from mice limb skeletal muscle.

Association of the WNT3 polymorphisms and non-syndromic cleft lip with or without cleft palate: evidence from a meta-analysis.

OBJECTIVE: This meta-analysis was conducted with the aim of investigating the association between WNT3 gene polymorphisms and non-syndromic cleft lip (CL) with or without cleft palate (NSCL/P) predisposition. METHODS: A comprehensive literature search was performed in six online databases including PubMed, Embase, ISI Web of Science, CENTRAL, CNKI, and Wanfang from inception up to June 2018 without language restriction. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (95%CIs) were calculated under allele model of inheritance to indicate the association between WNT3 polymorphisms and NSCL/P. Risk of bias was assessed through the Newcastle-Ottawa scale (NOS). Predetermined stratified and sensitivity analyses were performed using the RevMan 5.3 software, publication bias were evaluated by Egger's and Begg's tests. RESULTS: Seven case-control studies comprising 1617 NSCL/P patients and 2143 healthy controls were identified and included in the present study, a total of eight loci were investigated in the present study: rs3809857 was significantly associated with NSCL/P vulnerability (G compared with T, OR = 1.34, 95%CI: 1.15-1.56, P=0.0001), a significant association between rs9890413 polymorphism and NSCL/P susceptibility (A compared with G, OR = 1.25, 95%CI: 1.06-1.47, P=0.007) was detected as well. Since only few studies reported detailed data about the association between rs142167, rs7207916, rs199498, rs111769, rs12452064, rs11653738, and NSCL/P risk, these results were not combined using meta-analysis. CONCLUSION: Based on the findings of our current study, the rs3809857 and rs9890413 polymorphisms of WNT3 appeared to be associated with NSCL/P. Limited evidence is found to support the association between other WNT3 polymorphisms and risk of NSCL/P.

[Effect of cells in the epimysium conduit on the regeneration of peripheral nerve].

Objective: To investigate the effect of cells in the epimysium conduit (EMC) on the regeneration of sciatic nerve of mice. Methods: The epimysium of the 8-week-old male C57BL/6J enhanced green fluorescent protein (EGFP) mouse was trimmed to a size of 5 mm×3 mm, and prepared in a tubular shape (ie, EMC). Some epimysia were treated with different irradiation doses (0, 15, 20, 25, 30, 35 Gy) to inhibit cells migration. Then the number of migrating cells were counted, and the epimysia with the least migrating cells were selected to prepare EMC. Some epimysia were subjected to decellularization treatment and prepared EMC. HE and Masson staining were used to identify the decellularization effect. Twenty-four C57BL/6J wild-type mice were used to prepare a 3-mm-long sciatic nerve defect of right hind limb model and randomly divided into 3 groups ( n=8). EMC (group A), EMC after cell migration inhibition treatment (group B), and decellularized EMC (group C) were used to repair defects. At 16 weeks after operation, the midline of the regenerating nerve was taken for gross, toluidine blue staining, immunofluorescence staining, and transmission electron microscopy. Results: At 15 days, the number of migrating cells gradually decreased with the increase of irradiation dose. There was no significant difference between 30 Gy group and 35 Gy group ( P>0.05); there were significant differences between the other groups ( P<0.05). The epimysium after treatment with 35 Gy irradiation dose was selected for the in vivo experiment. After the decellularization of the epimysium, no nucleus was found in the epimysium and the epimysium could be sutured to prepare EMC. At 16 weeks after operation, the nerves in all groups were recanalized. The sciatic nerve was the thickest in group A, followed by group B, and the finest in group C. Immunofluorescence staining showed that the EGFP cells in group A were surrounded by regenerated axons. Toluidine blue staining and transmission electron microscopy observation showed that the number of regenerated axons and the thickness of regenerated myelin sheath in group A were significantly better than those in groups B and C ( P<0.05). There was no significant difference between groups B and C ( P>0.05). Conclusion: The cellular components of the epimysium participate in and promote the regeneration of the sciatic nerve in mice.

Muscle-derived stem cells in peripheral nerve regeneration: reality or illusion?

Owing to the complicated and time-consuming regenerative process, the repair of injured peripheral nerves depends largely on ongoing stem-cell therapy. Decades ago, researchers successfully isolated and identified muscle-derived stem cells (MDSCs) and discovered their potential for multidifferentiation. MDSCs play an important role in trauma repair associated with neuromuscular and vascular injury by simultaneously promoting tissue regrowth via direct differentiation and systematic secretion under physiological conditions. However, the isolation, culture, induction and application of MDSCs require further methodological analysis before clinical application. In this review, we comprehensively discuss the challenges associated with neural regeneration and reviewed the progress of stem cell based regenerative medicine, in an effort to realize the potential of MDSCs in nerve regeneration.

[Role of cell autophagy in peripheral nerve injury and regeneration].

Objective: To review the mechanism and effects of cell autophagy in the pathophysiology changes of peripheral nerve injury. Methods: The recent literature about cell autophagy in peripheral nerve injury and regeneration was extensively reviewed and summarized. Results: The researches through drugs intervention and gene knockout techniques have confirmed that the Schwann cell autophagy influences the myelin degeneration, debris clearance, inflammatory cells infiltration, and axon regeneration through JNK/c-Jun pathway. To adjust autophagy process could slow down the Wallerian degeneration, maintain the integrity of injured nerve, while the effect on axon regeneration is still controversial. Conclusion: The Schwann cell autophagy plays a key role in the pathophysiology changes of peripheral nerve injury, the further study of its mechanism could provide new methods for the therapy of peripheral nerve injury.