Galectins are carbohydrate-binding proteins that are involved in many physiological functions, such as inflammation, immune responses, cell migration, autophagy, and signaling. They are also linked to diseases such as fibrosis, cancer, and heart disease. Galectin-1 is a small protein with major functions. It is involved in the regulation of inflammation and the function of fat cells in the body, and has been associated with type 2 diabetes. Now, researchers from the University of Gothenburg have demonstrated how elevated levels of galectin-1 are linked to an increased risk of developing type 2 diabetes. The researchers also report the protein may also play a protective role for the kidneys among type 2 diabetes patients at high risk for diabetic nephropathy.

Their findings are published in the journal Diabetologia, in a paper titled, “The role of circulating galectin-1 in type 2 diabetes and chronic kidney disease: evidence from cross-sectional, longitudinal and Mendelian randomization analysis.”

“Galectin-1 modulates inflammation and angiogenesis, and cross-sectional studies indicate that galectin-1 may be a uniting factor between obesity, type 2 diabetes, and kidney function,” the researchers wrote.

Using the population-based Malmö Diet and Cancer Study–Cardiovascular Cohort (MDCS-CC), the researchers sought to determine whether circulating galectin-1 levels are associated with incident CKD and type 2 diabetes, independently of established risk factors.

“This is probably not as strange as it might sound. My own personal theory is that the actions of galectin-1 found in the kidney are linked to inflammatory processes, whereas the actions of galectin-1 in the adipose tissue appear to be largely linked to metabolic processes. Thus, we can expect to see different mechanisms at work and different outcomes for the same protein,” said Emanuel Fryk, one of the study’s lead authors and a resident physician in general medicine and a doctoral student at Sahlgrenska Academy, University of Gothenburg.

The study incorporates analyses of blood samples from more than 4,000 participants, collected between 1991 and 1994. Galectin-1 levels in blood samples were analyzed in order to assess the relation to risk of developing type 2 diabetes, around 18 years after the sample was initially collected. The authors do not suggest that galectin-1 should become a new tool in predicting who will develop diabetes, but rather a step forward in better understanding the disease.

“This is an important piece of the puzzle in the research field on why obesity is such a big risk factor for the disease. It is a new clue for scientists trying to find out exactly what happens in the body of individuals with obesity who later develop type 2 diabetes,” the authors wrote.

“In conclusion, galectin-1 shows a strong cross-sectional association with decreased kidney function, but two-sample MR analyses suggest a causal protective effect of galectin-1 on kidney function among participants with type 2 diabetes at high risk of diabetic nephropathy,” concluded the researchers. “Future studies are needed to explore the mechanisms by which galectin-1 affects kidney function and whether it could be a useful target for improving kidney function among individuals with type 2 diabetes.”