A preliminary study on recruitment of the bone marrow-derived stem cells into streptozotocin-induced diabetic mice

ObjectiveTo investigate whether the versatile bone marrow-derived stem cells could be transdifferentiated into insulin-positive cells in streptozotocin (STZ)-induced diabetic mice. MethodsCells were cultured under the conditions referred by Verfaillie method with some modification. Female Balb/c mice (6-8-week-old) were used as recipients, while male mice (3-week-old) as donors. Diabetic mice induced by STZ received 1-2×106 carboxyflurescein diacetate succinmidyl ester (CFSE, a kind of fluorescent label)-labeled cells via tail vein injection. At the end of 4-week test, chromosome Y in the female mice was determined by PCR and Cy3 labeled insulin and CFSE staining were observed under fluorenscent microscope. Pancreas were harvested for insulin immunochemistry and both islet and insulin positive area were calculated. ResultsThere were no significant changes of both blood glucose and body weight in test group and control group before and at the end of 4-weeks test, but normal blood glucose and increased body weight were found in the normal group. Chromosome Y was detected in all of the female mice with bone marrow-derived stem cell transplantation. Cells double stained with CFSE and insulin were found in pancreas with the number per section being 1.2±1.1.Insulin immunochemistry found that the islet neogenesis with the insulin-positive area was higher in these mice compared with those without transplantation [(474±380 vs 329±499)μm2 ,P=0.037], while there was no significant difference of islet area between them (10172±6303)μm2 vs(9857±4444)μm2.The islet and insulin area of the normal group [(17175±10495)μm2 and (1527±1788)μm2, respectively] were higher than those in test and control group. ConclusionThe transplanted bone marrow-derived stem cells could reside at the pancreatic site of STZ-induced diabetic mice and be transdifferantiated into insulin-positive cells.