The Effect Of Mesenchymal Stem Cells In Wharton's Jelly Of The Human Umbilical Cord On The Levels Of Blood Glucose And Body Weight In Rats With Type 1 Diabetic Mellitus

OBJECTIVE: Mesenchymal stem cells in Wharton's Jelly of the human umbilical cord (hUC-MSCs) had been transdifferentiated into islet-like cells utilizing the microenvironment that islet cells living on the protophase. But it was unknown that if these islet-like cells could react in vivo. This study was to explore the effect of these islet-like cells on the levels of blood glucose and body weight in rats with type 1 Diabetic Mellitus (DM).METHODS:1 MSCs were isolated and cultured from Wharton's Jelly of the human umbilical cord by tissue adherence.2 The islet cells were isolated from pancreas by collagenase V digesting.3 hUC-MSCs were induced by cocultureing with islet cells. Cell morphologic change was observed under inverted microscope.4 Rats were divided into normal control group and diabetic model group. The models of type 1 DM were made by intraperitoneal injection streptozocin(STZ). If random blood sugar of rats exceeded 16.7mmol/L for continuous three times, diabetic models were considered to succeed. The diabetic rats were divided into STZ experiment group and STZ control group.5 Postinduced cells were marked by Brdu.6 The positive cells for Brdu were transplanted into renal capsule of diabetic rats in STZ experiment group. Blood glucose and body weight of diabetic rats were observed.The experiment was ended after 8 weeks.7 The pancreas and kidney were removaled to carry out HE or immunohistochemistry dyeing at the end of the experiment.RESULTS:1 Blood glucose of rats increased remarkably after intraperitoneal injection STZ. Rats occurred urorrhagia and polydipsia symptoms. Their body weight didn't increase even cut down. The fur of diabetic rats were dim and some fur depilated. If random blood sugar of rats exceeded 16.7mmol/L for continuous three times, diabetic models were considered to succeed. The achievement ratio of diabetic models was 100 percent.2 Selecting ten visual fields randomly to count positive cells and negative cells under the microscope. Then, to calculate the positive rate of Brdu. The positive rate of Brdu was 92 percent.3 In the process of experiment, five rats died in STZ experiment group, two of which died of operation and three of which died of hyperglycemia. Eight rats died of hyperglycemia in STZ control group. There only had seventeen rats to carry out statistical analysis eventually.4 The change of blood glucose At eight weeks after cell transplantation, blood glucose in STZ experiment group decreased, there had statistical significance(p<0.05). Blood glucose in STZ control group and normal control group all had no statistical significance(p>0.05). Blood glucose in STZ experiment group were (29.00±3.68) mmol/L before cells transplantation and (20.31±1.70) mmol/L after cells transplantation. Blood glucose in STZ control group were (27.87±2.28) mmol/L before cells transplantation and (28.23±1.89) mmol/L after cells transplantation. Blood glucose in normal control group were (6.70±0.25) mmol/L before cells transplantation and (6.58±0.66) mmol/L after cells transplantation.5 The change of body weight At eight weeks after cell transplantation, body weight increased in three groups, there all had statistical significance (p<0.05). The increment of body weight in normal control group was most, the second was STZ experiment group. The increment of body weight in STZ control group was least. Blood glucose in normal control group were (275.33±28.49) g before cells transplantation and (496.50±20.51) g after cells transplantation. Body weight in STZ experiment group were (219.33±16.58) g before cells transplantation and (323.14±28.33) g after cells transplantation. Blood glucose in STZ control group were (207.25±13.63) g before cells transplantation and (246.00±27.54) g after cells transplantation.6 The HE dyeing showed that inequality of size pancreatic islet diffused distribution in normal pancreas. Their structures were clear. The quantity of islet decreased in diabetic rats of STZ control group. Their shapes were rugosity. Some hypertrophic acinar cells surrounded emarcide islets. Some large arteries were contractus in the interstitium of pancreas. Endothelial cells faced to lumens and the artery walls were incrassate. The fibrous tissue surrounding artery hyperplasy and formed some nerve fiber bundles. The lobule of pancreas atrophy. There had evident acinar lumina and some lymphocytes infiltrate into interstitium. The pancreas in STZ experiment group had the similar change to STZ control group.7 The HE dyeing showed that the verge of renal capsule was integrity and clear in normal control group and STZ control group. There had considerable cells between renal capsule and renal cortex in STZ experiment group. The renal capsule appeared break.8 The immunohistochemistry dyeing showed that there didn't have positive cells for insulin or Brdu below the renal capsule in normal control group and STZ control group. There had some positive cells for insulin whose endochylemas were brown as well as some positive cells for Brdu whose nucelus were brown between renal capsule and renal cortex in STZ experiment group.CONCLUSION: Islet-like cells derived from mesenchymal stem cells in Wharton's Jelly of the human umbilical cord could survival below the renal capsule of diabetic rats. These islet-like cells could lower blood glucose and increase body weight after cell transplantation.