Overexpression of Wnt3a facilitates the proliferation and neural differentiation of neural stem cells in vitro and after transplantation into an injured rat retina

Abstract

Neural stem cell-based therapy is a promising option for repair after injury. However, poor stem cell proliferation and insufficient differentiation of the stem cells into neurons are still difficult problems. The present study investigated whether transplantation of neural stem cells (NSCs) genetically modified to express Wnt3a is a promising approach to overcome these difficulties. We explored the possibility that Wnt3a might contribute to the therapeutic effect of NSC transplantation in retinal repair. The relative promotion of proliferation and neural differentiation by modified NSCs was investigated in a rat model of optic nerve crush. A recombinant lentivirus (Lenti-Wnt3a) was engineered to express Wnt3a. NSCs infected with control lentivirus (Lenti-GFP) or Lenti-Wnt3a were transplanted into the subretinal space immediately after the optic nerve crush. The proliferation and neural differentiation activity of the NSCs were assessed in vitro and in vivo. Overexpression of Wnt3a in NSCs induced activation of Wnt signaling, promoted proliferation, and directed the differentiation of the NSCs into neurons both in vitro and in vivo. Our study suggests that Wnt3a can potentiate the therapeutic benefits of NSC-based therapy in the injured retina.

Rac1 Guides Porf-2 to Wnt Pathway to Mediate Neural Stem Cell Proliferation

“…The isolation, culture, and identification of NSCs were done according to our earlier published studies (Yang et al, 2014). Briefly, pregnant Sprague–Dawley rats (Shanghai Experimental Animal Center, Shanghai, China) were deeply anesthetized with a mixture of ketamine and xylazine (3:1 ratio) and carefully dissected to get embryos (embryonic day 14).…”

“…NSCs were engrafted into the subretinal space immediately after the optic nerve crush with a transscleral approach as previous procedure (Yang et al, 2014). Briefly, under ophthalmic microscopic observation, the temporal conjunctiva was dissected at the limbus.…”

“…Cell counting in the histological analysis was done as described previously (Yang et al, 2014). Fourteen days after transplantation, the eyes were proceeded for the analysis of proliferation, and for differentiation at 10 weeks after transplantation.…”

“…Unfortunately, the standard therapeutic strategy for the treatment of optic nerve injury is absent. Neural stem cells (NSCs) can be isolated, proliferated, genetically manipulated and differentiated and reintroduced into pathologically altered central nerve system (CNS), which have been considered a potential therapeutic approach that may restore or sustain retinal function and prevent blindness in patients with optic nerve injury (Nishida et al, 2000; Banin et al, 2006; Harvey et al, 2006; Muller et al, 2006; Bi et al, 2009; Yang et al, 2014). However, engrafted NSCs usually could differentiate into glial cells rather than neurons in vivo , limiting their therapeutic effects (Zhou et al, 2009).…”

Efficient gene delivery to human umbilical cord mesenchymal stem cells by cationized Porphyra yezoensis polysaccharide nanoparticles

“…39 Meanwhile, HUMSCs have been ultimately converted into induced pluripotent stem cells via the codelivery of Yamanaka factors (c-Myc, Klf4, Sox2, and Oct4) using calcium phosphate nanoparticles, 43 which illustrated the remarkable inducibility of HUMSCs based on a nonviral gene-delivery system. In addition, the overexpression of Wnt3a 44 can direct the differentiation of neural stem cells into neurons both in vitro and in vivo by activating Wnt signaling, which is also a requirement for the maintenance, proliferation, and survival of neural progenitors when cultured under neurosphere conditions. 45 Previous studies have demonstrated that the overexpression of Wnt3a in highly self-renewable cells 46,47 might contribute to the formation and proliferation of neural cells, which could be a new and safe method for the recovery of spinal cord injury.…”