Differentiation of UC-MSCs into hepatocyte-like cells in partially hepatectomized model rats.

The aim of the study was to investigate the possibility of human umbilical cord mesenchymal stem cells (UC-MSCs) surviving and differentiating into hepatocyte-like cells in partially hepatectomized model rats. MSCs were isolated from human umbilical cord and cultured with collagenase digestion. Cell surface markers were detected and fifth generation UC-MSCs were labeled with PKH26. The partially hepatectomized model rats were injected with the labeled human umbilical cord MSCs and transplanted through the portal vein. The survival of the labeled cells, in differentiation conditions and the expression of hepatic marker albumin were observed at post-transplantation 1, 2 and 3 weeks under a fluorescence microscope. It was found that the human umbilical cord MSCs could be cultured and amplified in vitro. Following transplantation to the partially hepatectomized liver of the model rat, the cells survived and expresses the hepatic marker albumin in vivo. After being labeled with PKH26, the cells were visualized as red fluorescence under a fluorescence microscope. In the frozen sections of the liver, the marked cells scattered around and most of them expressed albumin with green fluorescence under the fluorescence microscope. In conclusion, the transplanted human umbilical cord MSCs survived and differentiated into hepatocyte-like cells. The human umbilical cord MSCs may therefore be a main source of hepatocytes in transplantation.

[Effects of triterpenoid from Psidium guajava leaves ursolic acid on proliferation, differentiation of 3T3-L1 preadipocyte and insulin resistance].

OBJECTIVE: To investigate the influences of triterpenoid from Psidium guajava Leaves (ursolic acid) on the proliferation, differentiation of 3T3-L1 preadipocyte, and its possible mechanism treat for insulin resistance. METHODS: 3T3-L1 preadipocyte was cultured in vitro. After adding ursolic acid to the culture medium for 48h, the cell viability was tested by MTT assay. Induced for 6 days, the lipid accumulation of adipocyte was measured by Oil Red O staining. The insulin resistant cell model was established with Dexamethasone. Cellular glucose uptake was determined with GOD-POD assays and FFA concentration was determined at the time of 48h. Secreted adiponectin were measured by ELISA. The protein levels of PPARgamma and PTP1B in insulin resistant adipocyte were measured by Western Blotting. RESULTS: Compared with medium control group, 30, 100 micromol/L ursolic acid could increase its proliferation and differentiation significantly (P < 0.05 or P < 0.01). Compared with the model group, ursolic acid at 100 micromol/L could enhance cellular glucose uptake of insulin resistant adipocyte significantly both in basic and insulin stimulation state (P < 0.01), while ursolic acid at 30 micromol/L could already enhance its glucose uptake significantly (P < 0.05), and could already decrease its FFA production significantly (P < 0.05). Ursolic acid at 30 micromol/L could increase the secretion of adiponectin on insulin resistant adipocyte significantly (P < 0.05), up-regulate the expression of PPARgamma protein (P < 0.05), but showed no effect on the PTP1B protein expression (P > 0.05). CONCLUSION: Ursolic acid can improve the proliferation and differentiation of 3T3-L1 preadipocyte, enhance cellular glucose uptake, inhibit the production of FFA, promote the secretion of adiponectin insulin resistant adipocyte, its mechanism may be related to upregulating the expression of PPARgamma protein.

[Nephro-protective effects of total triterpenoids from Psidium guajava leaves on type 2 diabetic rats].

OBJECTIVE: To investigate the nephro-protective effects of total triterpenoids from Psidium guajava leaves (TTPGL) on type 2 diabetic rats. METHODS: Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 35 mg/kg) and a high-fat diet. Diabetic rats were divided into five groups: diabetic model control, low-dose TTPGL-treated (60 mg/kg, L-TTPGL), medium-dose TTPGL-treated (120 mg/kg, M-TTPGL), high-dose TTPGL-treated (240 mg/kg, H-TTPGL) and rosiglitazone-treated (3 mg/kg, RSG). The rats received daily treatment for six weeks. At the end of the period,the levels of fasting blood glucose (FPG), fasting insulin (FINS), creatinine (Cr) and blood urea nitrogen (BUN) in serum were measured. Kidneys for histopathological evaluation were stained with Hematoxylin and Eosin (HE). RESULTS: Compared with normal control group, the level of FPG was increased, the insulin and insulin sensitivity index were decreased in the model group; The levels of BUN and Cr were increased with histopathological changes related to diabetic nephropathy in the kidney, which were the glomerular endothelium and mesangial cell proliferation, capillary narrowed, the base-membrane incrassation, glomerular swelling, cysts narrowed and tubules edema. Compared with the model group, the levels of FPG were decreased, serum insulin and insulin sensitivity index were increased significantly in M-TTPGL and H-TTPGL groups (P<0.01 or P<0.05); The levels of BUN and Cr were decreased significantly (P<0.01 or P<0.05) and the renal structural damages were improved significantly. CONCLUSION: TTPGL could decrease the level of blood glucose of diabetic rat effectively, increase the insulin sensitivity index and protect renal lesions in diabetic rats.