Browsing by Author "Squire, Maria E."

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    Examining the Role of Hypothalamus-Derived Neuromedin-U (NMU) in Bone Remodeling of Rats
    (MDPI, 2023-03-31) Born-Evers, Gabriella; Orr, Ashley L.; Hulsey, Elizabeth Q.; Squire, Maria E.; Hum, Julia M.; Plotkin, Lilian; Sampson, Catherine; Hommel, Jonathan; Lowery, Jonathan W.; Anatomy, Cell Biology and Physiology, School of Medicine
    Global loss of the neuropeptide Neuromedin-U (NMU) is associated with increased bone formation and high bone mass in male and female mice by twelve weeks of age, suggesting that NMU suppresses osteoblast differentiation and/or activity in vivo. NMU is highly expressed in numerous anatomical locations including the skeleton and the hypothalamus. This raises the possibility that NMU exerts indirect effects on bone remodeling from an extra-skeletal location such as the brain. Thus, in the present study we used microinjection to deliver viruses carrying short-hairpin RNA designed to knockdown Nmu expression in the hypothalamus of 8-week-old male rats and evaluated the effects on bone mass in the peripheral skeleton. Quantitative RT-PCR confirmed approximately 92% knockdown of Nmu in the hypothalamus. However, after six weeks, micro computed tomography on tibiae from Nmu-knockdown rats demonstrated no significant change in trabecular or cortical bone mass as compared to controls. These findings are corroborated by histomorphometric analyses which indicate no differences in osteoblast or osteoclast parameters between controls and Nmu-knockdown samples. Collectively, these data suggest that hypothalamus-derived NMU does not regulate bone remodeling in the postnatal skeleton. Future studies are necessary to delineate the direct versus indirect effects of NMU on bone remodeling.
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    NMUR1 in the NMU-Mediated Regulation of Bone Remodeling
    (MDPI, 2021-09-29) Hsiao, Yu-Tin; Manikowski, Kelli J.; Snyder, Samantha; Griffin, Nicole; Orr, Ashley L.; Hulsey, Elizabeth Q.; Born-Evers, Gabriella; Zukosky, Tara; Squire, Maria E.; Hum, Julia M.; Metzger, Corinne E.; Allen, Matthew R.; Lowery, Jonathan W.; Anatomy, Cell Biology and Physiology, School of Medicine
    Neuromedin-U (NMU) is an evolutionarily conserved peptide that regulates varying physiologic effects including blood pressure, stress and allergic responses, metabolic and feeding behavior, pain perception, and neuroendocrine functions. Recently, several lines of investigation implicate NMU in regulating bone remodeling. For instance, global loss of NMU expression in male and female mice leads to high bone mass due to elevated bone formation rate with no alteration in bone resorption rate or observable defect in skeletal patterning. Additionally, NMU treatment regulates the activity of osteoblasts in vitro. The downstream pathway utilized by NMU to carry out these effects is unknown as NMU signals via two G-protein-coupled receptors (GPCRs), NMU receptor 1 (NMUR1), and NMU receptor 2 (NMUR2), and both are expressed in the postnatal skeleton. Here, we sought to address this open question and build a better understanding of the downstream pathway utilized by NMU. Our approach involved the knockdown of Nmur1 in MC3T3-E1 cells in vitro and a global knockout of Nmur1 in vivo. We detail specific cell signaling events (e.g., mTOR phosphorylation) that are deficient in the absence of NMUR1 expression yet trabecular bone volume in femora and tibiae of 12-week-old male Nmur1 knockout mice are unchanged, compared to controls. These results suggest that NMUR1 is required for NMU-dependent signaling in MC3T3-E1 cells, but it is not required for the NMU-mediated effects on bone remodeling in vivo. Future studies examining the role of NMUR2 are required to determine the downstream pathway utilized by NMU to regulate bone remodeling in vivo.
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    Trends in Gender Authorship and Collaborations: A 30-Year Comparative Bibliometric Analysis of Manuscripts from The Journal of Bone and Joint Surgery and The Bone and Joint Journal
    (Hindawi, 2020-12-18) Squire, Maria E.; Schultz, Katherine; McDonald, Donnell; Meixner, Cory; Snyder, Dayton; Cooke, Alyssa M.; Davis, Jacob C.; Masso Maldonado, Sarina; Martinez Licha, Carlos R.; Whipple, Elizabeth C.; Kacena, Melissa A.; Loder, Randall T.; Orthopaedic Surgery, School of Medicine
    Publishing original peer-reviewed research is essential for advancement through all career stages. Fewer women than men hold senior-level positions in academic medicine and, therefore, examining publication trends relative to gender is important. The goal of this study was to examine and compare publication trends in The Journal of Bone and Joint Surgery (JBJS) and The Bone and Joint Journal (BJJ) with a particular emphasis on trends regarding author gender. Data was collected and analyzed for manuscripts published in JBJS and BJJ over the past 30 years. For manuscripts published in 1986, 1996, 2006, and 2016, we recorded the numbers of authors, manuscript pages, references, collaborating institutions, the position in the byline of the corresponding author, the country of the corresponding author, and the names of the first and corresponding author. We also calculated the normalized number of citations and corresponding author position. The number of authors, institutions, and countries collaborating on manuscripts published in both JBJS and BJJ increased over time. JBJS published more manuscripts from North America and BJJ published more manuscripts from Europe. In both journals, the percentage of women as first and/or corresponding author increased over time. Trends over the past 30 years have shown increased collaborations with greater citations in manuscripts published in JBJS and BJJ. In the same time period, both journals demonstrated a rise in the percentage of manuscripts with women first and/or corresponding authors, suggesting a decrease in the gender gap.