An increase of visceral fat affects human bone health causing fragility, mechanical strength reduction, and increased propensity to fractures because of impaired bone matrix microstructure and aberrant bone cell function. Adult Danio rerio (zebrafish) represents a powerful model to study both
metabolic diseases and bone metabolism. The aim of this study was to generate an obese adult zebrafish by high-fat diet and evaluate metabolic and bone tissue effects. Fish
blood glucose and
insulin levels were found to be altered in high-fat diet fish revealing a failure in β-cells
insulin production. Blood analysis of
adipokines revealed significant alterations in
adiponectin and
leptin levels that are common in human and other
obesity animal models.
Advanced glycation end products (AGEs), derived from
hyperglycemia condition, were found to be altered too. All these alterations were associated with an impaired bone metabolism. The scales of high-fat diet fish shown
bone resorption lacunae associated with an intense osteoclastic
tartrate-resistant acid phosphatase (TRAP) activity, whereas
alkaline phosphatase (ALP) decreased. These data suggest that an imbalance of fat metabolism alters energy metabolism generating an
osteoporosis-like phenotype in adult zebrafish scales. The zebrafish
obesity model can contribute to elucidate in vivo the molecular mechanisms of metabolic changes in human obese patients.