Coadministration Of Marrow Stromal Cells With Bcl-2 Gene Improves Neurological Deficits And Enhances IGF-1 Expression After Stroke In Rats

Coadministration of marrow stromal cells with bcl-2 gene improves neurological deficits and enhances IGF-1 expression after stroke in ratsIntroductionIschemic cerebrovascular diseases have threatened human health even life more and more seriously, but they still lack of effective treatment. Therefore, it is a focal point of research in the present neurological field that how to improve neurological functional recovery after the infarction.MSCs are multipotent, and some transplanted MSCs can differentiate into neurons and neuroglia cells in the recipient brain. Transplantation of MSCs into the brain of experimental stroke rats has been shown to improve neurological functional recovery. The effect of MSCs transplantation is dependent on the number of transplanted MSCs. However, the livability of MSCs after transplantation is poor. Thus, to research a new approach to augment the livability of MSCs transplantation is the key for the therapy effect of MSCs to the regenerative treatment of stroke.Bcl-2 gene is the first gene that has been acknowaged to have the function of antiapoptosis. Bcl-2 gene is also effective on improvement of neurological functional deficits after stroke in rats.Taking these findings together, bcl-2 gene infusion may have additive or synergetic effects on MSCs transplantation, which may result in improvement of neurological functional recovery. The purpose of this study was to test the hypotheses that coadministration of bone marrow stromal cells with bcl-2 gene improve neurological deficits, promotes MSCs survival, inhibits cell apoptosis and enhance IGF-1 expression after stroke in rats compared to individual therapy. MethodsWistar rats (n=40) were subjected to 2-hour middle cerebral artery occlusion and randomly devided into four groups: MSCs+bcl-2 group (n=10), MSCs group (n=10), bcl-2 group (n=10) and control group (n=10). 3 hours after reperfusion, MSCs+bcl-2 group and bcl-2 group received intra-arterial infusion of bcl-2 gene; 24 hours after reperfusion, MSCs+bcl-2 group and MSCs group received intravenous transplantation of MSCs. 1 day, 3 days, 7 days and 14 days after reperfusion, mNSS was performed to examine neurological function. 3 days and 14 days after reperfusion, immunohistological assessments were performed to examine the effects of these treatments; TUNEL staining was performed to examine cellular apoptosis.Determination of the result: Taken two sections of each sample, examined and photographed using computerized video imaging microscopy. Data were acquired from different fields in frontal lobe, apical lobe and corpus striatum region by analysing the positive area percentage or counting the number of positive cells at high power magnification (400×).Statistical Analysis: All data were expressed as (?)±s. The results were analyzed using t-test or ANOVA and processed by SPSS 13.0. A value P＜0.05 was considered statistically significant.Results1,Identification of plasmid pLXSN-bcl-2: pLXSN-bcl-2 cut by the EcoRⅠ, XhoⅠdouble enzyme has two belts, one is 850 bp bcl-2 piece, and another is 5863 bp pLXSN split-ring piece.2,The neurological score significantly improved in the MSCs, bcl-2 and MSCs+bcl-2 groups compared with the control group. Importantly, improvement in the MSCs+bcl-2 group was significantly greater than that in the MSCs and bcl-2 groups.3,The number of engrafted MSCs in the MSCs+bcl-2 group was significantly higher than that in the MSCs group. 4,The expression of IGF-1 significantly increased in the MSCs+bcl-2 group compared with the MSCs and bcl-2 groups.5,The expression of Bcl-2 significantly increased in the MSCs+bcl-2 group compared with the MSCs and bcl-2 groups.6,The cell apoptosis significantly decreased in the MSCs+bcl-2 group compared with the MSCs and bcl-2 groups.Conclusions1,bcl-2 gene enhanced the therapeutic potency of MSCs possibly through inhibition of MSCs apoptosis;2,Enhancing IGF-1 expression might be one of the therapeutic mechanisms of MSCs treated stroke in rats.