Researchers have identified elevated levels of a protein called Miro1 (Mitochondrial Rho GTPase1) in the skeletal muscle of people with Type 2 diabetes as a potential contributor to insulin resistance — and a possible future drug target.
What Miro1 does: Miro1 sits on the outer membrane of mitochondria (the cell’s energy producers). The team found that accumulation of Miro1 impairs muscle’s response to insulin.
Evidence across three levels:
- In people: Miro1 levels were elevated in skeletal muscle of people with Type 2 diabetes.
- In preclinical models: Removing Miro1 restored muscle insulin sensitivity, showing a causal effect.
- With exercise: In a randomized controlled trial of people with obesity and Type 2 diabetes, aerobic exercise vs. standard medical care led to reductions in muscle Miro1, along with improved insulin sensitivity and muscle energy production.
Study details: Published in Nature Communications. Led by senior author Dr. John P. Kirwan — who did the work at LSU’s Pennington Biomedical Research Center and is now Executive Director of the OU Health Harold Hamm Diabetes Center at the University of Oklahoma. First author is Elizabeth Heintz, doctoral candidate at Pennington Biomedical; co-corresponding author is Christopher Axelrod, now also at Harold Hamm.
Significance and next steps: Insulin resistance in muscle is central to Type 2 diabetes but its molecular causes remain unclear. This work proposes Miro1 as a new therapeutic target and helps explain why exercise is effective. The authors note more research is needed to determine if targeting Miro1 can lead to new treatments.