Estrogen Regulation of the Wnt/β-catenin Pathway in Osteocytes in Response to Mechanical Loading

Title from PDF of title page viewed January 27, 2021Dissertation advisor: Mark L. JohnsonVitaIncludes bibliographical references (page 101-107)Thesis (Ph.D.)--School of Dentistry and School of Pharmacy. University of Missouri--Kansas City, 2019Osteoporosis is a major health concern, especially for women who are peri- and post-menopausal. During this time, estrogen levels dramatically decline followed by a subsequent loss of bone density, which increases risk of bone fracture. The increased fragility of bone negatively affects the patient’s quality of life by limiting the performance of everyday activities and increasing the frequency of physician visits and medical care costs. Estrogen exerts its effects on bone at various levels. One important, yet poorly understood, aspect of its action is on the osteocyte, the most abundant cell in bone and thought to be the primary cell involved in sensing mechanical loads. The Wnt/β-catenin pathway is activated in the osteocyte upon mechanical loading. The role of estrogen (specifically estrogen loss) in regulation of this pathway in osteocytes is not fully understood. I hypothesize that estrogen is a critical factor in the responsiveness of the osteocyte to mechanical loading via regulation of the Wnt/β-catenin pathway; and in the absence of estrogen, osteocytes will have a decreased activation upon mechanical loading. The specific aims are: 1) determine the effects of ovariectomy (OVX) on the ability of the osteocyte to activate the Wnt/β-catenin pathway in response to mechanical load; 2) determine the role of estrogen on the activation of the Wnt/β-catenin pathway in vitro in response to mechanical load. The OVX group failed to activate osteocyte β-catenin signaling at 24 hours post-loading, which is normal peak activation time point of the pathway following loading. Trabecular bone had significant decreases in bone mineral density, bone volume/total volume and trabecular thickness in the OVX group, along with increases in osteoclasts and decreases in osteoblast numbers. Bone micro-architecture (lacunar size and volume) and biomechanical properties remained unchanged. In vitro studies showed osteocyte activation with fluid flow and the addition of Wnt3a, and activation was attenuated with the addition of an estrogen receptor inhibitor. These findings are consistent with a change in the intrinsic ability of the osteocyte to respond to loading in the absence of estrogen and support the hypothesis that estrogen plays a critical role in the osteocyte’s responsiveness to mechanical loading.Introduction -- Methods and Materials -- Results -- Discussion -- Conclusion

The Development of Novel Nanodiamond Based MALDI Matrices for the Analysis of Small Organic Pharmaceuticals

The utility of novel functionalized nanodiamonds (NDs) as matrices for matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) is described herein. MALDI-MS analysis of small organic compounds (<1000 Da) is typically complex due to interferences from numerous cluster ions formed when using conventional matrices. To expand the use of MALDI for the analysis of small molecules, , novel matrices were designed by covalently linking conventional matrices (or a lysine moiety) to detonated NDs. Four new functionalized NDs were evaluated for their ionization capabilities using five pharmaceuticals with varying molecular structures. Two ND matrices were able to ionize all tested pharmaceuticals in the negative ion mode, producing the deprotonated ions [M-H]-. Ion intensity for target analytes was generally strong with enhanced signal-to-noise ratios compared with conventional matrices. The negative ion mode is of great importance for biological samples as interference from endogenous compounds is inherently minimized in the negative ion mode. Since the molecular structures of the tested pharmaceuticals did not suggest that negative ion mode would be preferable, this result magnifies the importance of these findings. On the other hand, conventional matrices primarily facilitated the ionization as expected in the positive ion mode, producing either the protonated molecules [M+H]+ or cationic adducts (typically producing complex spectra with numerous adduct peaks). The data presented in this study suggests that these matrices may offer advantages for the analysis of low molecular weight pharmaceuticals/metabolites

Increasing Physical Activity Among African-American Women and Girls

WHITT-GLOVER, M. C., D. J. BRAND, M. E. TURNER, S. A. WARD, and E. M. JACKSON. Increasing physical activity among African-American women and girls. Curr. Sports Med. Rep., Vol. 8, No. 6, pp. 318-324, 2009. The benefits of physical activity on diseases and risk factors are well known. Despite the known benefits, many segments of the population, particularly African-American women and girls, do not obtain adequate levels of physical activity. Strategies are needed to identify successful and sustainable interventions to increase physical activity among this population. We reviewed literature published between 2007 and 2009 that focused on increasing physical activity or fitness among this population. We identified 37 studies, 11 of which focused on increasing physical activity. This article summarizes the findings from those 11 studies and provides recommendations for improving strategies to increase physical activity in African-American women and girls

Agricultural data management and sharing: Best practices and case study

Agricultural data are crucial to many aspects of production, commerce, and research involved in feeding the global community. However, in most agricultural research disciplines standard best practices for data management and publication do not exist. Here we propose a set of best practices in the areas of peer review, minimal dataset development, data repositories, citizen science initiatives, and support for best data management. We illustrate some of these best practices with a case study in dairy agroecosystems research. While many common, and increasingly disparate data management and publication practices are entrenched in agricultural disciplines, opportunities are readily available for promoting and adopting best practices that better enable and enhance data-intensive agricultural research and production

Microbial glutamate metabolism predicts intravenous cocaine self-administration in diversity outbred mice.

The gut microbiome is thought to play a critical role in the onset and development of psychiatric disorders, including depression and substance use disorder (SUD). To test the hypothesis that the microbiome affects addiction predisposing behaviors and cocaine intravenous self-administration (IVSA) and to identify specific microbes involved in the relationship, we performed 16S rRNA gene sequencing on feces from 228 diversity outbred mice. Twelve open field measures, two light-dark assay measures, one hole board and novelty place preference measure significantly differed between mice that acquired cocaine IVSA (ACQ) and those that failed to acquire IVSA (FACQ). We found that ACQ mice are more active and exploratory and display decreased fear than FACQ mice. The microbial abundances that differentiated ACQ from FACQ mice were an increased abundance of Barnesiella, Ruminococcus, and Robinsoniella and decreased Clostridium IV in ACQ mice. There was a sex-specific correlation between ACQ and microbial abundance, a reduced Lactobacillus abundance in ACQ male mice, and a decreased Blautia abundance in female ACQ mice. The abundance of Robinsoniella was correlated, and Clostridium IV inversely correlated with the number of doses of cocaine self-administered during acquisition. Functional analysis of the microbiome composition of a subset of mice suggested that gut-brain modules encoding glutamate metabolism genes are associated with the propensity to self-administer cocaine. These findings establish associations between the microbiome composition and glutamate metabolic potential and the ability to acquire cocaine IVSA thus indicating the potential translational impact of targeting the gut microbiome or microbial metabolites for treatment of SUD. This article is part of the Special Issue on Microbiome & the Brain: Mechanisms & Maladies

A Qualitative Exploration of the Functional, Social, and Emotional Impacts of the COVID-19 Pandemic on People Who Use Drugs

Since 2020, people who use drugs (PWUD) experienced heightened risks related to drug supply disruptions, contamination, overdose, social isolation, and increased stress. This study explored how the lives of PWUD changed in Philadelphia over a one-year period. Using semi-structured interviews with 20 participants in a Housing First, low-barrier medication for opioid use (MOUD) program in Philadelphia, the effects of the first year of the COVID-19 pandemic on the daily lives, resources, functioning, substance use, and treatment of PWUD were explored. Interviews were analyzed using a combination of directed and conventional content analysis. Six overarching themes emerged during data analysis: (1) response to the pandemic; (2) access to MOUD and support services; (3) substance use; (4) impacts on mental health, physical health, and daily functioning; (5) social network impacts; and (6) fulfillment of basic needs. Participants reported disruptions in every domain of life, challenges meeting their basic needs, and elevated risk for adverse events. MOUD service providers offset some risks and provided material supports, treatment, social interaction, and emotional support. These results highlight how there were significant disruptions to the lives of PWUD during the first year of the COVID-19 pandemic and identified critical areas for future intervention and policies

Prognostic role of clusterin in resected adenocarcinomas of the lung

Rationale Clusterin expression may change in various human malignancies, including lung cancer. Patients with resectable non-small cell lung cancer (NSCLC), including adenocarcinoma, have a poor prognosis, with a relapse rate of 30\u201350% within 5 years. Nuclear factor kB (Nf-kB) is an intracellular protein involved in the initiation and progression of several human cancers, including the lung. Objectives We investigate the role of clusterin and Nf-kB expression in predicting the prognosis of patients with early-stage surgically resected adenocarcinoma of the lung. Findings The level of clusterin gradually decreased from well-differentiated to poorly differentiated adenocarcinomas. Clusterin expression was significantly higher in patients with low-grade adenocarcinoma, in early-stage disease and in women. Clusterin expression was inversely related to relapse and survival in both univariate and multivariate analyses. Finally, we observed an inverse correlation between Nf-kB and clusterin. Conclusions Clusterin expression represents an independent prognostic factor in surgically resected lung adenocarcinoma and was proven to be a useful biomarker for fewer relapses and longer survival in patients in the early stage of disease. The inverse correlation between Nf-kB and clusterin expression confirm the previously reported role of clusterin as potent down regulator of Nf-kB

A first in man phase I trial of the oral immunomodulator, indoximod, combined with docetaxel in patients with metastatic solid tumors

BackgroundIndoleamine 2,3-dioxygenase (IDO) is an enzyme that tumors use to create a state of immunosuppression. Indoximod is an IDO pathway inhibitor. Preclinical studies demonstrated that indoximod combined with chemotherapy was synergistic in a mouse model of breast cancer. A phase I 3+3 trial was designed to study the combination of docetaxel and indoximod.MethodsDocetaxel was administered at 60 mg/m2 intravenously every 3 weeks dose levels 1-4 and 75 mg/m2 for dose level 5. Indoximod was given at 300, 600, 1000, 2000, and 1200 mg PO twice daily continuously for levels 1-5, respectively. Serum drug levels were measured.ResultsTwenty-seven patients were treated, with 22 evaluable for response. DLTs included grade 3 dehydration (level 1), hypotension(level 4), mucositis (level 4) and grade 5 enterocolitis (level 2). Dose level 5 is the recommended phase II dose. The most frequent adverse events were fatigue (58.6%), anemia (51.7%), hyperglycemia (48.3%), infection (44.8%), and nausea (41.4%). There were 4 partial responses (2 breast, 1 NSCLC, 1 thymic tumor). No drug-drug interactions were noted.ConclusionsDocetaxel plus indoximod was well tolerated with no increase in expected toxicities or pharmacokinetic interactions. It was active in a pretreated population of patients with metastatic solid tumors