Do sodium-glucose co-transporter-2 inhibitors increase plasma glucagon by direct actions on the alpha cell? And does the increase matter for the associated increase in endogenous glucose production?

SGLT2 inhibitors and AMPK: The road to cellular housekeeping?

Sodium-glucose co-transporter-2 (SGLT2) inhibitors, known as Gliflozins, are a class of Glucose-lowering drugs in adults with type 2 diabetes (T2D) that induce glucosuria by blocking SGLT2 co-transporters in the proximal tubules. Several lines of evidence suggest that SGLT2 inhibitors regulate multiple mechanisms associated with the regulation of varying cellular pathways. The 5'-adenosine monophosphate-activated protein kinase (AMPK) pathway plays an important role in metabolic homeostasis by influencing cellular processes. Recently, it has been shown that SGLT2 inhibitors can affect the AMPK pathway in differing physiological and pathological ways, resulting in kidney, intestinal, cardiovascular, and liver protective effects. Additionally, they have therapeutic effects on nonalcoholic fatty liver disease and diabetes mellitus-associated complications. In this review, we summarize the results of studies of AMPK-associated therapeutic effects of SGLT2 inhibitors in different organelle functions.

Effects of GLP-1RA and SGLT2i, Alone or in Combination, on Mouse Models of Type 2 Diabetes Representing Different Disease Stages

Glucagon-like peptide-1 receptor agonist (GLP-1RA) and sodium-dependent glucose transporter 2 inhibitor (SGLT2i), in addition to lowering glucose, have pleiotropic effects on the heart, kidneys, and liver. These drugs have thus come into widespread use for treating type 2 diabetes (T2DM). However, mechanistic comparisons and effects of combining these drugs have not been adequately studied. Employing diet-induced obese (DIO) mice and db/db mice as models of the early and advanced stages of T2DM, we evaluated effects of single or combined use of liraglutide (a GLP-1RA) and ipragliflozin (a SGLT2i). Treatments with liraglutide and/or ipragliflozin for 28 days improved glycemic control and reduced hepatic lipid accumulation similarly in DIO mice. In contrast, in db/db mice, despite similar favorable effects on fatty liver, liraglutide exerted no beneficial effects on glycemic control. Improved glycemic control in db/db mice treated with ipragliflozin was accompanied by increased pancreatic β-cell area and insulin content, both of which tended to rise further when ipragliflozin was combined with liraglutide. Our data suggest that liraglutide is more efficient at an earlier stage and ipragliflozin can be effective in both stages. In addition, their combined use is a potential option for treating advanced stage diabetes with fatty liver disease.