Regeneration of islet β‐cells in tree shrews and rats

摘要

Backgroud:Current understanding of injury and regeneration of isletβ‐cells in diabetes is mainly based on rodent studies.The tree shrew is now generally accepted as being among the closest living relatives of primates,and has been widely used in animal experimentation.However,there are few reports on islet cell composition and regeneration ofβ‐cells in tree shrews.Methods:In this study,we examined the changes in islet cell composition and regeneration ofβ‐cells after streptozotocin(STZ)treatment in tree shrews compared with Sprague‐Dawley rats.Injury and regeneration of isletβ‐cells were observed using hematoxylin and eosin(HE)staining and immunohistochemical staining for insulin,glucagon,somatostatin and PDX‐1.Results:Our data showed that in rats islet injury was most obvious on day 3 after injection,and islet morphologies were significantly restored by day 21.Regeneration of isletβ‐cells was very pronounced in rats,and mainly involved regeneration of centro‐acinar cells and transformation of extra‐islet ductal cells.In tree shrews,the regeneration of isletβ‐cells was not as significant.On days 3 and 7,only scattered regenerated cells were observed in the remaining islets.Further,no regeneration of centro‐acinar cells was observed.Conclusion:The results suggest that the repair mechanism of isletβ‐cells in tree shrews is similar to that of humans.