Browsing by Author "Hatch, Jennifer"

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    Effects of Raloxifene and tibial loading on bone mass and mechanics in male and female mice
    (Taylor & Francis, 2022) Berman, Alycia G.; Damrath, John G.; Hatch, Jennifer; Pulliam, Alexis N.; Powell, Katherine M.; Hinton, Madicyn; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
    Raloxifene (RAL) is a selective estrogen receptor modulator (SERM) that has previously been shown to cause acellular benefits to bone tissue. Due to these improvements, RAL was combined with targeted tibial loading to assess if RAL treatment during periods of active bone formation would allow for further mechanical enhancements. To do so, structural, mechanical, and microstructural effects were assessed in bone from C57BL/6 mice that were treated with RAL (0.5 mg/kg), tibial loading, or both for 6 weeks, beginning at 10 weeks of age. Ex vivo microcomputed tomography (CT) images indicated RAL and loading work together to improve bone mass and architecture, especially within the cancellous region of males. Increases in cancellous bone volume fraction were heavily driven by increases in trabecular thickness, though there were some effects on trabecular spacing and number. In the cortical regions, RAL and loading both increased cross-sectional area, cortical area, and cortical thickness. Whole-bone mechanical testing primarily indicated effects of loading. Further characterization through Raman spectroscopy and nanoindentation showed load-based changes in mineralization and micromechanics, while both loading and RAL caused changes in the secondary collagen structure. In contrast to males, in females, there were large load-based effects in the cancellous and cortical regions, resulting in increased whole-bone mechanical properties. RAL had less of an effect on cancellous and cortical architecture, though some effects were still present. In conclusion, RAL and loading work together to impact bone architecture and mechanical integrity, leading to greater improvements than either treatment individually.
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    Sex-Specific Bone Phenotype in the Streptozotocin-Induced Murine Model of Diabetes
    (2021-08) Hatch, Jennifer; Wallace, Joseph M.; Allen, Matthew R.; Bone, Robert N.; Li, Jilliang; Na, Sungsoo
    Bone disease and degradation is a ubiquitous problem, the complexity and treatment of which humanity has only begun to understand. Diabetes Mellitus is a disease which, in all forms, profoundly effects the organs of the body, bone included. As is often the case in biology, there are inherent differences between the sexes when considering skeletal development and disease progression and outcome. Although there are several reported mouse models for diabetes, until now there has been no characterization of bone disease in any model where diabetes occurs with equal frequency in males and females in greater than 90% of animals. In this study, a protocol for reliable induction of diabetes in both sexes using intraperitoneal injections of Streptozotocin was developed. The resulting bone phenotype in male and female mice was characterized and compared to weight and age matched control groups. In this model female diabetic mice exhibited a robust deficit in bone quality, while both sexes experienced loss of beta-cell mass and increased glycation of hemoglobin rendering the diabetic mice unable to produce insulin endogenously. Further, these mice were unable to metabolize exogenous insulin injected during insulin tolerance testing. This model is a strong candidate for future exploration of osteoporotic bone disease, Diabetes Mellitus, and the link between estrogen and glucose sensitivity.