Effects Of Rehmannia Glutinosa Oligosaccharides And Bone Marrow Mesenchymal Stem Cells Transplantation In Rats With Heart Failure

Background:Rehmannia Glutinosa is a traditional Chinese herbal medicine and has the function of invigorating the 'kidney' and enhancing vital energy. Rehmannia Glutinosa Oligosaccharides(RGOs) is a low molecular weight polysaccharides extracted from Rehmannia Glutinosa. In the theroy of Traditional Chinese Medicine, the kidney is an organ storing the "congenital essential substance" and heart failure is mainly caused by 'kidney' deficiency. We hypothesized that there might be close relationship between stem cells and "congenital essential substance", and RGOs may have synergitic effect with bone marrow MSCs transplantation in improving cardiac function of heart failure.ObjectiveTo observe the effects of RGOs on MSCs transplantation in rats with heart failure and to investigate the pharmacological actions of RGOs to MSCs in vitro.MethodsThe first part: MSCs were isolated from adult rat bone marrow and purified by consecutive passages. The effect of RGOs on the proliferation of MSCs was investigated by MTT assay. The 8th passage of MSCs were induced by RGOs and 5-Azacytidine (5-Aza) separately or combined to differentiate into cardiomyocytes- -like cells. The expression of CK-MB, cTnI, CX 43, ERK1/2 and p- ERK1/2 was detected by chemical method, immumo- fluorescence method and Western-blot respectively, and compared with control group.The second part: A chronic heart failure model was created by administering Adriamycin (total dose 15mg/kg) intraperitoneally in male Wistar rats. Four weeks after the last administration, the survived rats were randomly divided into four groups: one given an injection of blank culture medium via tail vein for two times (control, group), one given an injection of 4×10~7 MSCs via tail vein for two times (MSCs, group), one given an injection of 4×10~7 MSCs via tail vein for two times plus an intragastric administration of RGOs(200mg/kg/d) (MSCs/ RGOs, group), and one given an intragastric administration of RGOs (200mg/kg/d) (RGOs, group). Four weeks later, cardiac function was evaluated by echocardiography. The injected MSCs from male rats were pre-lablled with DAPI before transplantation and were traced by fluorescent microscope. The tissue capillary vessel density was counted by the VI factor positive cells, collagen volume fraction(CVF) of left ventricular was calculated by Picrosirius red staining.ResultsRGOs significantly promote the proliferation of MSCs. The expression of CK-MB, cTnI and CX43 was positive in the induced MSCs and negative or very weakly positive in non-induced MSCs. The transformation ratio of MSCs into cardiomyocyte-like cells was higher in the RGOs/5-Aza group than in the RGOs group and 5-Aza group(both P<0.05). The expression of p-ERK1/2 was higher in the RGOs group than in the 5-Aza, RGOs/ 5-Aza and non-induced groups.Compared with the control group, the heart function was improved, the capillary vessel density increased and CVF of left ventricular decreased in the MSCs, MSCs/RGOs, and RGOs groups. The effect was more evident in the RGOs/ MSCs group than in the MSCs group and RGOs group. The MSCs lablled with DAPI were observed in the recipients heart and the number of it was higher in the RGOs / MSCs group than in the MSCs group.ConclusionsRGOs can promote the proliferation of MSCs and induce MSCs to differentiate into cardiomyocyte-like cells in vitro. MSCs transplanted intravenously can migrtae into impaired heart. RGOs has synergistic effect with MSCs transplantation in improving the cardiac function of rats with heart failure.