Intra-Peritoneal Delivery of Genetically Modified Human Mesenchymal Stromal Cells (MSCs) Can Improve Glucose Homeostasis in Diet Induced Obese (DIO) Diabetic Mouse Models By Upregulating UCP1 in White Fat

Presentation Number: OR13-3
Date of Presentation: April 2nd, 2017

Cleyton C. Domingues*, Nabanita Kundu, Neeki Ahmadi and Sabyasachi Sen
The George Washington University, Washington, DC

Abstract

Background: MSCs are undifferentiated, multipotent cells. We have previously showed that High Glucose (HG, 25mM) exposure promotes adipogenic differentiation, inflammation, increased formation of ROS and decreased cellular oxygen consumption rate (OCR) in human adipose-derived MSCs. However, antioxidants SOD1 and SOD2 upregulation reduced intracellular ROS and improved OCR in presence of HG environment. Hypothesis: We hypothesized that intracellular (SOD1, SOD2, Catalase) and extracellular (SOD3) anti-oxidant upregulation using gene over-expression reduces ROS and improves glucose homeostasis in hyperglycemic mouse models. Methods: We used GFP-containing Adenoviral constructs to upregulate anti-oxidants (SOD1, SOD2, SOD3, Catalase) in MSCs. Modified MSCs were delivered intra-peritoneally to DIO (60% and 45% high-fat diet) hyperglycemic C57BL/6J mice. Results: Mice receiving SOD2 upregulated MSCs improved glucose tolerance at week 4 with least AUC (area under the curve) compared to SOD1 and Null (control) in both 60% and 45% DIO mice. Catalase also improved insulin tolerance besides glucose tolerance in 60% DIO mice. Interestingly, RT-PCR of pericardial fat showed significant increases in mRNA expression of not only UCP1 (25-100,000-fold) but also PRDM-16 (2-10-fold) in both 60% and 45% fat DIO mice that received antioxidants upregulated MSCs, compared to mice receiving Null upregulated MSCs. For omental fat, an increase in mRNA expression of UCP1 was also observed in 60% fat DIO mice (1,000-fold for SOD1 and SOD2; 3,000 and 6,000-fold for catalase and SOD3, respectively), while for mice fed with 45% fat diet only those receiving SOD1 and SOD2 upregulated MSCs presented UCP1 (1,000 and 11,000-fold respectively) and PRDM16 (2-fold) mRNA upregulation. Histology of the same fat depots revealed less hyperplastic adipocytes in mice receiving SOD2 and catalase-upregulated MSCs, particularly in omental samples. We are confirming our finding of beiging or brown fat formation (supported by concomitant upregulation of UCP1 and PRDM-16) in white fat depots by western blot of UCP1 and PRDM16. We are also analyzing serum samples to assess whether MSC delivery can reduce systemic inflammation, by ELISA of IL6 and TNFalpha. Conclusion: We conclude that delivery of specific antioxidant upregulated MSCs to the inflamed adipocyte depots in diabetic DIO model may be the key to improve glucose homeostasis most likely by up-regulating UCP-1 in the host tissue. Therefore, this approach may be a novel yet safe therapeutic tool to reduce insulin resistance and combat DIO associated impaired glucose homeostasis that can lead to prediabetes and diabetes.

 

Nothing to Disclose: CCD, NK, NA, SS