Purpose of review Osteoarthritis is a debilitating disease leading to joint degeneration, inflammation, pain, and disability. Despite efforts to develop a disease modifying treatment, the only accepted and available clinical approaches involve palliation. Although many factors contribute to the development of osteoarthritis, the gut microbiome has recently emerged as an important pathogenic factor in osteoarthritis initiation and progression. This review examines the literature to date regarding the link between the gut microbiome and osteoarthritis. Recent findings Studies showing correlations between serum levels of bacterial metabolites and joint degeneration were the first links connecting a dysbiosis of the gut microbiome with osteoarthritis. Further investigations have demonstrated that microbial community shifts induced by antibiotics, a germ-free environment or high-fat are important underlying factors in joint homeostasis and osteoarthritis. It follows that strategies to manipulate the microbiome have demonstrated efficacy in mitigating joint degeneration in osteoarthritis. Moreover, we have observed that dietary supplementation with nutraceuticals that are joint protective may exert their influence via shifts in the gut microbiome. Summary Although role of the microbiome in osteoarthritis is an area of intense study, no clear mechanism of action has been determined. Increased understanding of how the two factors interact may provide mechanistic insight into osteoarthritis and lead to disease modifying treatments.

AR-12/OSU-03012 is an antitumor celecoxib-derivative that has progressed to Phase I clinical trial as an anticancer agent and has activity against a number of infectious agents including fungi, bacteria and viruses. However, the mechanism of these activities has remained unclear. Based on a chemical-genetic profiling approach in yeast, we have found that AR-12 is an ATP-competitive, time-dependent inhibitor of yeast acetyl coenzyme A synthetase. AR-12-treated fungal cells show phenotypes consistent with the genetic reduction of acetyl CoA synthetase activity, including induction of autophagy, decreased histone acetylation, and loss of cellular integrity. In addition, AR-12 is a weak inhibitor of human acetyl CoA synthetase ACCS2. Acetyl CoA synthetase activity is essential in many fungi and parasites. In contrast, acetyl CoA is primarily synthesized by an alternate enzyme, ATP-citrate lyase, in mammalian cells. Taken together, our results indicate that AR-12 is a non-nucleoside acetyl CoA synthetase inhibitor and that acetyl CoA synthetase may be a feasible antifungal drug target.

Knowledge surveys are a type of confidence survey in which students rate their confidence in their ability to answer questions rather than answering the questions. These surveys have been discussed as a tool to evaluate student in-class or curriculum-wide learning. However, disagreement exists as to whether confidence is actually an accurate measure of knowledge. With the concomitant goals of assessing content-based learning objectives and addressing this disagreement, we present herein a pretest/posttest knowledge survey study that demonstrates a significant difference correctness on graded test questions at different levels of reported confidence in a multi-semester timeframe. Questions were organized into Bloom’s taxonomy, allowing for the data collected to further provide statistical analyses on strengths and deficits in various levels of Bloom’s reasoning with regard to mean correctness. Collectively, students showed increasing confidence and correctness in all levels of thought but struggled with synthesis-level questions. However, when students were only asked to rate confidence and not answer the accompanying test questions, they reported significantly higher confidence than the control group which was asked to do both. This indicates that when students do not attempt to answer questions, they have significantly greater confidence in their ability to answer those questions. Additionally, when students rate only confidence without answering the question, resolution across Bloom’s levels of reasoning is lost. Based upon our findings, knowledge surveys can be an effective tool for assessment of both breadth and depth of knowledge, but may require students to answer questions in addition to rating confidence to provide the most accurate data.

Purpose of Review Osteoarthritis (OA) is the most common forms of arthritis in the general population, accounting for more pain and functional disability than any other musculoskeletal disease. There are currently no approved disease modifying drugs for OA. In the absence of effective pharmacotherapy, many patients with OA turn to nutritional supplements and nutraceuticals, including collagen derivatives. Collagen hydrolyzates and ultrahydrolyzates are terms used to describe collagens that have been broken down into small peptides and amino acids in the presence of collagenases and high pressure. Recent Findings This article reviews the relevant literature and serves as a White Paper on collagen hydrolyzates and ultrahydrolyzates as emerging supplements often advertised to support joint health in OA. Collagen hydrolyzates have demonstrated some evidence of efficacy in a handful of small scale clinical trials, but their ability to treat and reverse advanced joint disease remains highly speculative, as is the case for other nutritional supplements. Summary The aim of this White Paper is to stimulate research and development of collagen-based supplements for patients with OA and other musculoskeletal diseases at academic and industrial levels. This White Paper does not make any treatment recommendations for OA patients in the clinical context, but simply aims to highlight opportunities for scientific innovation and interdisciplinary collaboration, which are crucial for the development of novel products and nutritional interventions based on the best available and published evidence.

Staphylococcus aureus causes a wide spectrum of disease, with the site and severity of infection dependent on virulence traits encoded within genetically distinct clonal complexes (CCs) and bacterial responses to host innate immunity. The production of nitric oxide (NO) by activated phagocytes is a major host response to which S. aureus metabolically adapts through multiple strategies that are conserved in all CCs, including an S. aureus nitric oxide synthase (Nos). Previous genome analysis of CC30, a lineage associated with chronic endocardial and osteoarticular infections, revealed a putative NO reductase (Nor) not found in other CCs that potentially contributes to NO resistance and clinical outcome. Here, we demonstrate that Nor has true nitric oxide reductase activity, with nor expression enhanced by NO stress and anaerobic growth. Furthermore, we demonstrate that nor is regulated by MgrA and SrrAB, which modulate S. aureus virulence and hypoxic response. Transcriptome analysis of the S. aureus UAMS-1, UAMS-1 Δnor, and UAMS-1 Δnos strains under NO stress and anaerobic growth demonstrates that Nor contributes to nucleotide metabolism and Nos to glycolysis. We demonstrate that Nor and Nos contribute to enhanced survival in the presence of human human polymorphonuclear cells and have organ-specific seeding in a tail vein infection model. Nor contributes to abscess formation in an osteological implant model. We also demonstrate that Nor has a role in S. aureus metabolism and virulence. The regulation overlap between Nor and Nos points to an intriguing link between regulation of intracellular NO, metabolic adaptation, and persistence in the CC30 lineage. IMPORTANCE Staphylococcus aureus can cause disease at most body sites, and illness spans asymptomatic infection to death. The variety of clinical presentations is due to the diversity of strains, which are grouped into distinct clonal complexes (CCs) based on genetic differences. The ability of S. aureus CC30 to cause chronic infections relies on its ability to evade the oxidative/nitrosative defenses of the immune system and survive under different environmental conditions, including differences in oxygen and nitric oxide concentrations. The significance of this work is the exploration of unique genes involved in resisting NO stress and anoxia. A better understanding of the functions that control the response of S. aureus CC30 to NO and oxygen will guide the treatment of severe disease presentations.

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OBJECTIVES/GOALS: Osteoarthritis (OA) is a cartilage destroying disease. We are investigating abaloparatide (ABL) activation of parathyroid hormone receptor type 1 (PTH1R), which is expressed by articular chondrocytes in OA. We propose ABL treatment is chondroprotective in murine PTOA via stimulation of matrix production and inhibition of chondrocyte maturation. METHODS/STUDY POPULATION: 16-week-old C57BL/6 male mice received destabilization of the medial meniscus (DMM) surgery to induce knee PTOA. Beginning 2 weeks post-DMM, 40 μg/kg of ABL (or saline) was administered daily via subcutaneous injection and tissues were harvested after 6 weeks of daily injections and 8 weeks after DMM surgery. Harvested joint tissues were used for histological and molecular assessment of OA using three 5 μm thick sagittal sections from each joint, 50 μm apart, cut from the medial compartment of injured knees. Safranin O/Fast Green tissue staining and immunohistochemistry-based detection of type 10 collagen (Col10) and lubricin (Prg4) was performed using standard methods. Histomorphometric quantification of tibial cartilage area and larger hypertrophic-like cells was performed using the Osteomeasure system. RESULTS/ANTICIPATED RESULTS: Safranin O/Fast Green stained sections showed a decreased cartilage loss in DMM joints from ABL-treated versus saline-treated mice. Histomorphometric analysis of total tibial cartilage area revealed preservation of cartilage tissue on the tibial surface. Immunohistochemical analyses showed that upregulation of Col10 in DMM joints was mitigated in the cartilage of ABL-treated mice, and chondrocyte expression of Prg4 was increased in uncalcified cartilage areas in ABL-treated group. The Prg4 finding suggests a matrix anabolic effect that may counter OA cartilage loss. Quantification of chondrocytes in uncalcified and calcified tibial cartilage areas revealed a reduction in the number of larger hypertrophic-like cells in ABL treated mice, suggesting deceleration of hypertrophic differentiation. DISCUSSION/SIGNIFICANCE: Cartilage preservation/regeneration therapies would fill a critical unmet need. We demonstrate that an osteoporosis drug targeting PTH1R decelerates PTOA in mice. ABL treatment was associated with preservation of cartilage, decreased Col10, increased Prg4, and decreased number of large hypertrophic-like chondrocytes in the tibial cartilage.