Dysfunction of DMT1 and miR-135b in the gut-testis axis in high-fat diet male mice

Obese patients have been found to be susceptible to iron deficiency, and malabsorption of dietary iron is the cause of obesity-related iron deficiency (ORID). Divalent metal transporter 1 (DMT1) and ferroportin (FPN), are two transmembrane transporter proteins expressed in the duodenum that are closely associated with iron absorption. However, there have been few studies on the association between these two proteins and the increased susceptibility to iron deficiency in obese patients. Chronic inflammation is also thought to be a cause of obesity-related iron deficiency, and both conditions can have an impact on spermatogenesis and impair male reproductive function. Based on previous studies, transgenerational epigenetic inheritance through gametes was observed in obesity.

Our results  showed that obese mice had decreased blood iron levels (p < 0.01), lower protein and mRNA expression for duodenal DMT1 (p < 0.05), but no statistically significant variation in mRNA expression for duodenal FPN (p > 0.05); there was an increase in sperm miR-135b expression (p < 0.05). Bioinformatics revealed ninety overlapping genes and further analysis showed that they were primarily responsible for epithelial cilium movement, fatty acid beta-oxidation, protein dephosphorylation, fertilization, and glutamine transport, which are closely related to spermatogenesis, sperm development, and sperm viability in mice.

In obese mice, we observed downregulation of DMT1 in the duodenum and upregulation of miR-135b in the spermatozoa.