Introduction: Measurement of pancreatic beta cell mass in animal models is a common assay in diabetes researches. Novel whole-organ clearance methods in conjunction with transgenic mouse models hold tremendous promise to improve beta cell mass measurement methods. Here, we proposed a refined method to estimate the beta cell mass using a new transgenic Tg(Pdx1-GFP) mouse model and a recently developed free-of-acrylamide clearing tissue (FACT) protocol. Methods: First, we generated and evaluated a Tg(Pdx1-GFP) transgenic mouse model. Using the FACT protocol in our model, we could quantify the beta cell mass and alloxan-induced beta cell destruction in whole pancreas specimens. Results: Compiled fluorescent images of pancreas resulted in enhanced beta cell mass characterization in FACT-cleared sections (2928869±, 120215 AU) compared to No-FACT cleared sections (1292372±, 325632 AU). Additionally, the total number of detected islets with this method was significantly higher than the other clearance methods (155. 7 and 109, respectively). Using this method, we showed green fluorescent protein (GFP) expression confined to beta cells in Tg(Pdx1-GFP) transgenic. This enhanced GFP expression enabled us to accurately measure beta cell loss in a beta cell destruction model. The results suggest that our proposed method can be used as a simple, and rapid assay for beta cell mass measurement in islet biology and diabetes studies. Conclusion: The Tg(Pdx1-GFP) transgenic mouse in conjunction with the FACT protocol can enhance large-scale screening studies in the field of diabetes.

Objective: To treat a type 1 diabetic rat model with Adipose Tissue-Derived Stem Cells (ADSC) Expressing Pancratic Duodenal Homeobox 1 (Pdx1)Materials and Methods: Human or rat ADSC were transduced with Pdx1, examined for pancreatic cell characteristics, and transplanted into type 1 diabetic rats.Results: ADSC tranduced with Pdx1 exhibited beta cell characteristics. Transplantation of Pdx1 expressing ADSC partially reverted the progress of type 1diabetesConclusion: ADSC-expressing Pdx1 is promising for treating type1 diabetes

Type I diabetes is an immunologically-mediated devastation of insulin producing cells (IPCs) in the pancreatic islet. Stem cells that produce b-cells are a new promising tool. Adult stem cells such as mesenchymal stem cells (MSCs) are self renewing multi potent cells showing capabilities to differentiate into ectodermal, mesodermal and endodermal tissues. Pancreatic and duodenal homeobox factor 1 (PDX1) is a master regulator gene required for embryonic development of the pancreas and is crucial for normal pancreatic islets activities in adults.Materials and Methods: We induced the over-expression of the PDX1 gene in human bone marrow MSCs (BM-MSCs) by Lenti-PDX1 in order to generate IPCs. Next, we examine the ability of the cells by measuring insulin/c-peptide production and INSULIN and PDX1 gene expressions.Results: After transduction, MSCs changed their morphology at day 5 and gradually differentiated into IPCs. INSULIN and PDX1 expressions were confirmed by real time polymerase chain reaction (RT-PCR) and immunostaining. IPC secreted insulin and C-peptide in the media that contained different glucose concentrations.Conclusion: MSCs differentiated into IPCs by genetic manipulation. Our result showed that lentiviral vectors could deliver PDX1 gene to MSCs and induce pancreatic differentiation.

Background: Leptin and adiponectin are two hormones, which are released from adipocytes in order to control energy expenditure. Both hormones are also involved in glucose homeostasis through control of insulin secretion from pancreatic islets. Since Pdx1, PPARg, and foxm1 play important roles in islets function, it is essential to understand how these genes are regulated in the islets of Langerhans.Objectives: We have designed an experiment to identify the effect of leptin and adiponectin treatment on Pdx1, PPARg, and foxm1 transcription.Materials and Methods: Islets were isolated from adult male rats by collagenase and incubated with different concentrations of leptin and adiponectin for 24 hours. Next, by means of real time PCR, we evaluated the gene transcription related to a housekeeping gene. The effect of leptin and adiponectin on insulin secretion was evaluated by ELISA.Results: Leptin decreased PPARg transcription and insulin secretion, while adiponectin significantly increased Pdx1 and PPARg transcription and insulin secretion in rat islets. The transcription of foxm1 did not change in the islet cells treated with leptin or adiponectin.Conclusions: These findings indicate the possibility that Pdx1 and PPARg transcription is a mediator of leptin and adiponectin function in control of insulin secretion and glucose homeostasis in pancreatic islets.