Adipose Function in Health and Disease
The adipose organ is complex and composed of many different cell types including adipocytes, endothelial cells, preadipocytes and immune cells (such as macrophages and lymphocytes). Aside from the well-known role of adipocytes to store energy, adipocytes secrete many adipocytokines that can modulate systemic energy homeostasis and diseases such as diabetes and obesity. Fat has often been cast as a “bad player” in diseases. However, we know that patients lacking fat develop hypertension and severe insulin resistance. The reason for this apparent paradox is that fat cells normally secrete many beneficial adipocytokines. Disease states may arise when there is a loss of these beneficial adipokines coupled with an increase in deleterious adipokines. The Lo lab is interested in understanding how the adipose organ strikes this delicate balance and harnessing the power of specific adipokines to prevent and treat diseases.
We made the discovery that the adipokine adipsin can control blood sugar levels in a mouse model of type 2 diabetes. Adipsin acts via the pancreatic beta cell to induce insulin secretion. In support of our basic research studies, we found that human patients with type 2 diabetes mellitus who are deficient in insulin also have lower circulating levels of adipsin. We are finding ways to leverage this novel adipose to pancreatic islet axis to combat diabetes mellitus.
The lab is actively exploring other new adipokines and adipocyte factors involved in metabolism and inflammatory diseases. Stay tuned!
Pancreatic Islet Biology and Dysregulation in Diabetes
The pancreatic islets are clusters of endocrine cells embedded within the exocrine part of the pancreas. Although these islets are relatively “small”, they have a large impact on whole body energy metabolism. The beta cell is responsible for secreting insulin, a hormone that is a central regulator of blood glucose levels. In type 2 diabetes or prediabetes (where blood glucose levels are too high), insulin may initially increase to help compensate for hyperglycemia. However, in advanced and chronic cases of type 2 diabetes there is a decline in beta cell secretion of insulin termed beta cell failure. There are no current treatments that can arrest or reverse beta cell failure.
We are using state of the art molecular techniques to investigate how beta cell failure develops. Our goal is that by understanding the molecular mechanisms behind beta cell failure, we will be able to come up with innovative approaches to this difficult problem.