Social isolation through single housing negatively affects trabecular and cortical bone in adult male, but not female, C57BL/6J mice

Authors

Rebecca V. Mountain, Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, USA.
Audrie L. Langlais, Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, USA; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA.
Dorothy Hu, Department of Medicine, Harvard Medical School, Boston, MA, USA; Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
Roland Baron, Department of Medicine, Harvard Medical School, Boston, MA, USA; Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
Christine W. Lary, Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, USA; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA; Roux Institute, Northeastern University, Portland, ME, USA.
Katherine J. Motyl, Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, USA; Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA; Tufts University School of Medicine, Tufts University, Boston, MA, USA.Follow

Document Type

Article

Publication Date

4-10-2023

Institution/Department

Center for Molecular Medicine, MaineHealth Institute for Research

Journal Title

Bone

Abstract

Social isolation is a potent form of psychosocial stress and is a growing public health concern, particularly among older adults. Even prior to the onset of the COVID-19 pandemic, which has significantly increased the prevalence of isolation and loneliness, researchers have been concerned about a rising "epidemic" of loneliness. Isolation is associated with an increased risk for many physical and mental health disorders and increased overall mortality risk. In addition to social isolation, older adults are also at greater risk for osteoporosis and related fractures. While researchers have investigated the negative effects of other forms of psychosocial stress on bone, including depression and PTSD, the effects of social isolation on bone have not been thoroughly investigated. The aim of this study was to test the hypothesis that social isolation would lead to bone loss in male and female C57BL/6J mice. 16-week-old mice were randomized into social isolation (1 mouse/cage) or grouped housing (4 mice/cage) for four weeks. Social isolation significantly decreased trabecular (BV/TV, BMD, Tb. N., Tb. Th.) and cortical bone (Ct.Th., Ct.Ar., Ct.Ar./Tt.Ar., pMOI, Ct.Por.) parameters in male, but not female mice. Isolated male mice had signs of reduced bone remodeling represented by reduced osteoblast numbers, osteoblast-related gene expression and osteoclast-related gene expression. However, isolated females had increased bone resorption-related gene expression, without any change in bone mass. Overall, our data suggest that social isolation has negative effects on bone in male, but not female mice, although females showed suggestive effects on bone resorption. These results provide critical insight into the effects of isolation on bone and have key clinical implications as we grapple with the long-term health impacts of the rise in social isolation related to the COVID-19 pandemic.

First Page

116762

Recommended Citation

Mountain RV, Langlais AL, Hu D, Baron R, Lary CW, Motyl KJ. Social isolation through single housing negatively affects trabecular and cortical bone in adult male, but not female, C57BL/6J mice [published online ahead of print, 2023 Apr 10]. Bone. 2023;116762. doi:10.1016/j.bone.2023.116762