ABSTRACT
ObjectiveTo observe the effect of ginsenoside Rg1 （G-Rg1） on the biological activity of cryopreserved Schwann cells （SCs） of the rat sciatic nerve and explore the feasibility of G-Rg1 in reducing the cryopreservation-induced injury in SCs. MethodBilateral sciatic nerves of SD rats were randomly divided into a fresh group， a blank group， and five G-Rg1 groups of different doses （1×10-7， 1×10-6， 1×10-5， 1×10-4， and 1×10-3 mol·L-1）. The nerves in the blank group and the G-Rg1 groups were preserved in liquid nitrogen solutions containing 0， 1×10-7， 1×10-6， 1×10-5， 1×10-4， and 1×10-3 mol·L-1 G-Rg1 for four weeks. The apoptosis of SCs was detected by TdT-mediated dUTP-biotin nick end labeling （TUNEL）/S100 immunofluorescence staining. The expression of cysteinyl aspartate-specific protease （Caspase）-9， Caspase-3， major histocompatibility complex （MHC）-Ⅰ， and MHC-Ⅱ was detected by Western blot. Subsequently， all nerves were cultured in the incubator at 37 ℃ with 5% CO2 for 7 days. The expression of glial cell line-derived neurotrophic factor （GDNF） and nerve growth factor （NGF） was detected by Western blot. In addition， the above cryopreserved nerves in the blank group and the 1×10-6， 1×10-5， and 1×10-4 mol·L-1 G-Rg1 groups were transplanted to the Wistar rats by allografting （blank transplantation group and the 1×10-6， 1×10-5， and 1×10-4 mol·L-1 G-Rg1 transplantation groups）， and fresh sciatic nerve allograft and isograft control group were set up. Sixteen weeks after transplantation， compound muscle action potential （CMAP） and nerve conduction velocity （NCV） were measured by electrophysiology. Nerve filament （NF）200 immunofluorescence staining， transmission electron microscopy， and toluidine blue staining were used to analyze the histology of the regenerated nerves. ResultCompared with the fresh group， the blank group and the G-Rg1 groups showed increased expression of Caspase-9， Caspase-3， and the apoptosis of SCs （P<0.05，P<0.01） and decreased expression of GDNF， NGF， MHC-Ⅰ， and MHC-Ⅱ （P<0.01）. Compared with the results in the blank group， the expression of Caspase-9 and Caspase-3 decreased in the 1×10-7， 1×10-6， 1×10-5，1×10-4 mol·L-1 G-Rg1 groups （P<0.01）， and the apoptosis of SCs was reduced in the 1×10-7-1×10-4 mol·L-1 G-Rg1 groups（P<0.05，P<0.01） and increased in the 1×10-3 mol·L-1 group （P<0.05）， while the expression of GDNF and NGF increased in the 1×10-7， 1×10-6， 1×10-5，1×10-4 mol·L-1 G-Rg1 groups and decreased in the 1×10-3 mol·L-1 group （P<0.05）. There was no statistical significance in the expression of MHC-Ⅰ and MHC-Ⅱ between the blank group and the G-Rg1 groups. Compared with the 1×10-7 mol·L-1 and 1×10-3 mol·L-1 G-Rg1 groups， the 1×10-6 1×10-5， 1×10-4 mol·L-1 G-Rg1 groups showed decreased expression of Caspase-3 and the apoptosis of SCs （P<0.05，P<0.01） and increased expression of GDNF and NGF （P<0.05，P<0.01）. There was no statistical significance in MHC-Ⅰ and MHC-Ⅱ expression among G-Rg1 groups. Sixteen weeks after transplantation， compared with the isograft group， the blank transplantation group and the G-Rg1 transplantation groups showed decreased CMAP， NCV， myelin sheath thickness， and number of myelinated nerve fibers （P<0.01）， and the 1×10-6 and 1×10-4 mol·L-1 G-Rg1 transplantation groups showed decreased NF200 （P<0.01）. Compared with the allograft group， the blank transplantation group and the G-Rg1 transplantation groups showed increased CMAP， NCV， NF200， myelin sheath thickness， and number of myelinated nerve fibers （P<0.05，P<0.01）. Compared with the blank transplantation group， the G-Rg1 transplantation groups showed increased CMAP， NCV， NF200， myelin sheath thickness， and number of myelinated nerve fibers （P<0.05，P<0.01）. Among all groups of G-Rg1 transplantation， each index of the 1×10-5 mol·L-1 G-Rg1 transplantation group was superior to that of the 1×10-4 and 1×10-6 mol·L-1 G-Rg1 transplantation group （P<0.05）. ConclusionG-Rg1 at a certain centration can maintain the biological activity of cryopreserved SCs of rat sciatic nerve， alleviate the cryopreservation-induced injury of rat sciatic nerve， and promote nerve regeneration after allograft.
ABSTRACT
Ice easily recrystallizes during warming after vitrification, and antifreeze protein (AFP) can inhibit the re-crystallization. However, no study has evaluated the effect of AFP treatment only thereon during warming. This study sought to compare AFP treatment protocols: a conventional protocol with AFP treatment during vitrification and first-step warming and a new protocol with AFP treatment during the first-step warming only. According to the protocols, 10 mg/mL of LeIBP (a type of AFP) was used. Five-week-old B6D2F1 mouse ovaries were randomly divided into a vitrified-warmed control and two experimental groups, one treated with the conventional AFP treatment protocol (LeIBP-all) and the other with the new AFP treatment protocol (LeIBP-w). For evaluation, ratios of ovarian follicle integrity, apoptosis, and DNA double-strand (DDS) damage/repairing were analyzed. The LeIBP-treated groups showed significantly higher intact follicle ratios than the control, and the results were similar between the LeIBP-treated groups. Apoptotic follicle ratios were significantly lower in both LeIBP-treated groups than the control, and the results were not significantly different between the LeIBP-treated groups. With regard to DDS damage/repairing follicle ratio, significantly lower ratios were recorded in both LeIBP-treated groups, compared to the control, and the results were similar between the LeIBP-treated groups. This study demonstrated that both protocols with LeIBP had a beneficial effect on maintaining follicle integrity and preventing follicle apoptosis and DDS damage. Moreover, the new protocol showed similar results to the conventional protocol. This new protocol could optimize the mouse ovary vitrification-warming procedure using AFP, while minimizing the treatment steps.