VEGF overexpression in transplanted NSCs promote recovery of neurological function in rats with cerebral ischemia by modulating the Wnt signal transduction pathway

Neural stem cell transplantation is a good method to treat stroke, but the mechanism is still unclear. Therefore, this study aims to explore the regulatory mechanism of VEGF overexpression in transplanted NSCs to promote the recovery of neural function in ischemic rats by regulating Wnt signal transduction pathways. We amplified VEGF gene fragments by PCR and transfected them into NSCs with Ad5 adenovirus. Rat brain IRI model was established by MCAO method, and VEGF transfected NSCs (VEGF-NSCs) were transplanted 24 h after successful IRI model. One week after the transplant, cognitive function was assessed using a neurological deficit score; Brain injury was assessed by histopathology; Photochemical and ELISA methods were used to detect oxidative stress markers and inflammatory factors, respectively. Western blotting has been detected in molecules of the Wnt signaling pathway. The results showed that the transduced NSCs express VEGF at least for 14 days. VEGF-NSCs transplantation (VNT) improved spatial learning and memory in rats, and inhibited oxidative stress injury, inflammatory response, and histopathological injury. VNT also resulted in significant changes in the phosphorylation levels of β-catenin and GSK-3β proteins, ultimately triggering activation of the Wnt signal transduction pathway. These results suggest that the neuroprotective effects of VNT may be related to the regulation of the Wnt signal transduction pathway.

Role of Sfrps in cardiovascular disease

Secreted frizzled-related proteins (Sfrps) are a family of secreted proteins that bind extracellularly to Wnt ligands and frizzled receptors. This binding modulates the Wnt signaling cascade, and Sfrps interact with their corresponding receptors. Sfrps are thought to play an important role in the pathological mechanism of cardiac disease such as myocardial infarction, cardiac remodeling, and heart failure. However, the overall role of Sfrps in cardiac disease is unknown. Some members of the Sfrps family modulate cellular apoptosis, angiogenesis, differentiation, the inflammatory process, and cardiac remodeling. In this review, we summarize the evidence of Sfrps association with cardiac disease. We also discuss how multiple mechanisms may underlie Sfrps being involved in such diverse pathologies.

Wnt signal transduction pathways: modules, development and evolution

Background

Wnt signal transduction pathway (Wnt STP) is a crucial intracellular pathway mainly due to its participation in important biological processes, functions, and diseases, i.e., embryonic development, stem-cell management, and human cancers among others. This is why Wnt STP is one of the highest researched signal transduction pathways. Study and analysis of its origin, expansion and gradual development to the present state as found in humans is one aspect of Wnt research. The pattern of development and evolution of the Wnt STP among various species is not clear till date. A phylogenetic tree created from Wnt STPs of multiple species may address this issue.

Results

In this respect, we construct a phylogenetic tree from modules of Wnt STPs of diverse species. We term it as the ‘Module Tree’. A module is nothing but a self-sufficient minimally-dependent subset of the original Wnt STP. Authenticity of the module tree is tested by comparing it with the two reference trees.

Conclusions

The module tree performs better than an alternative phylogenetic tree constructed from pathway topology of Wnt STPs. Moreover, an evolutionary emergence pattern of the Wnt gene family is created and the module tree is tallied with it to showcase the significant resemblances.

Electronic supplementary material

The online version of this article (doi:10.1186/s12918-016-0299-7) contains supplementary material, which is available to authorized users.