Testicular Sertoli cells protect pancreatic islet grafts from alloand autoimmune destruction; however, the mechanism(s) of protection is unclear. The aim of this study was to determine whether Fas ligand (FasL) and/ or transforming growth factor (TGF), immunoregulatory proteins produced by Sertoli cells, might mediate the protective effects of these cells against autoimmune destruction of islet...

Role of GLP-1 and GIP in beta cell compensatory responses to beta cell attack and insulin resistance were examined in C57BL/6 mice lacking functional receptors for GLP-1 and GIP. Mice were treated with multiple low dose streptozotocin or hydrocortisone. Islet parameters were assessed by immunohistochemistry and hormone measurements were determined by specific enzyme linked immunoassays. Wild-ty...

AIMS Recent studies suggest that decreasing oxidative stress is crucial to achieve successful islet transplantation. Thioredoxin-1 (TRX), which is a multifunctional redox-active protein, has been reported to suppress oxidative stress. Furthermore, it also has anti-inflammatory and anti-apoptotic effects. In this study, we investigated the effects of TRX on early graft loss after islet transplan...

Although it has been hypothesized that initial hyperperfusion followed by late hypoperfusion in islet circulation occurs in rodent models of type 2 diabetes, islet blood flow has not been measured during prediabetic phase. We studied islet blood flow in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of slowly progressive obese type 2 diabetes. Islet blood flow was measured by the two-c...

Islet amyloid polypeptide (IAPP) aggregates to form amyloid fibrils in patients with type 2 diabetes and acts as a potent stimulus for interleukin (IL)-1β secretion by bone marrow-derived macrophages. We sought to determine the contribution of resident islet macrophages to IAPP-induced inflammation and β-cell dysfunction. In cultured islets, macrophages (F4/80(+)CD11b(+)CD11c(+) cells) were req...

Islet cell tumors, endocrine neoplasm arising from pancreatic islets of Langerhans, are histologically difficult to diagnose as benign or malignant. Molecular markers are associated with the clinical characteristics that most of insulinoma are usually benign tumors, whereas other islet cell tumors are malignant but have not been identified. In this context, we newly found that an endothelial an...

Since the development of the Edmonton Islet Transplantation Protocol, islet transplantation has given new hope to patients with type 1 diabetes. Like solid organ transplantation, one of the biggest challenges islet transplantation faces is the shortage of available donor tissue. Finding an alternative source of islet tissue has become an increasingly important field of study. The possibility of...

An unusual structure resembling an islet of Langerhans was described in the pancreatic ductal epithelium of a presumably normal human male. Further studies to establish the identities of both islet and duct were performed. The original hematoxylin and eosin section served for histological description, as well as for nuclear volume analysis to characterize levels of beta cell polyploidy. The sec...

Islet cell transplantation has therapeutic potential to treat type 1 diabetes, which is characterized by autoimmune destruction of insulin-producing pancreatic islet β cells. It represents a minimal invasive approach for β cell replacement, but long-term blood control is still largely unachievable. This phenomenon can be attributed to the lack of islet vasculature and hypoxic environment in the...

Objective(s):Some pathologic situations such as diabetes and metabolic syndrome are associated with alternation in nitric oxide level. Incidence of these condition increases with aging. On the other hand, insulin secretion is modulated by nitric oxide, and nitric oxide synthase (NOS) activity is also altered in diabetes. In this study, modification in the enzyme activity associated with aging a...