Behavior and Musculoskeletal Effects of Chronic D-Galactose Treatment in Mice: Role of Heme Oxygenase-1

Chronic d-galactose (d-gal) treatment is a model to induce accelerated aging-like phenotypes in rodents. However, the sex differences in behavioral and musculoskeletal manifestations of this model are not well understood. Heme oxygenase-1 (HO-1) is a cytoprotective protein that may have anti-aging properties. The goal of this study was to better understand the sex differences in the behavioral and musculoskeletal effects of chronic d-gal treatment in C57BL/6J mice, as well as the role of HO-1 induction or inhibition. Eight-week-old male and female mice received daily saline or d-gal injections (500 mg/kg, s.c.) for 12 weeks. After this time, mice in the d-gal group were randomized into three groups (n = 6/group/sex): d-gal, d-gal + cobalt protoporphyrin (CoPP) (5 mg/kg, s.c. weekly), and d-gal + zinc deutroporphyrin bisglycol (ZnBG) (42 mg/kg, i.p. triweekly) for a period of 4 weeks. Open-field, novel-object recognition, Barnes maze, grip strength, micro-computed tomography (µ-CT), histology, and protein analysis were performed. Chronic d-gal treatment resulted in a sexual dimorphic response, with female mice being more prone to develop deficits in both short- and long-term spatial memory as well as in non-spatial memory. Male mice exhibited deficits only in long-term spatial memory when treated chronically with d-gal. Inhibition of HO-1 was protective in both females and males. Chronic d-gal treatment did not accelerate the development of osteoporosis or sarcopenia in either males or females. Our results demonstrate a sexual dimorphic response to the chronic effects of d-gal treatment on aging, with greater effects in females than in males, which is dependent on HO-1.