Modulation of Macrophage Activation State Protects Tissue from Necrosis during Critical Limb Ischemia in Thrombospondin-1-Deficient Mice

International audienceBACKGROUND: Macrophages, key regulators of healing/regeneration processes, strongly infiltrate ischemic tissues from patients suffering from critical limb ischemia (CLI). However pro-inflammatory markers correlate with disease progression and risk of amputation, suggesting that modulating macrophage activation state might be beneficial. We previously reported that thrombospondin-1 (TSP-1) is highly expressed in ischemic tissues during CLI in humans. TSP-1 is a matricellular protein that displays well-known angiostatic properties in cancer, and regulates inflammation in vivo and macrophages properties in vitro. We therefore sought to investigate its function in a mouse model of CLI. METHODS AND FINDINGS: Using a genetic model of tsp-1(-/-) mice subjected to femoral artery excision, we report that tsp-1(-/-) mice were clinically and histologically protected from necrosis compared to controls. Tissue protection was associated with increased postischemic angiogenesis and muscle regeneration. We next showed that macrophages present in ischemic tissues exhibited distinct phenotypes in tsp-1(-/-) and wt mice. A strong reduction of necrotic myofibers phagocytosis was observed in tsp-1(-/-) mice. We next demonstrated that phagocytosis of muscle cell debris is a potent pro-inflammatory signal for macrophages in vitro. Consistently with these findings, macrophages that infiltrated ischemic tissues exhibited a reduced postischemic pro-inflammatory activation state in tsp-1(-/-) mice, characterized by a reduced Ly-6C expression and a less pro-inflammatory cytokine expression profile. Finally, we showed that monocyte depletion reversed clinical and histological protection from necrosis observed in tsp-1(-/-) mice, thereby demonstrating that macrophages mediated tissue protection in these mice. CONCLUSION: This study defines targeting postischemic macrophage activation state as a new potential therapeutic approach to protect tissues from necrosis and promote tissue repair during CLI. Furthermore, our data suggest that phagocytosis plays a crucial role in promoting a deleterious intra-tissular pro-inflammatory macrophage activation state during critical injuries. Finally, our results describe TSP-1 as a new relevant physiological target during critical leg ischemia

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Health economic analyses of the justice community opioid innovation network (JCOIN)

The Justice Community Opioid Innovation Network (JCOIN) will generate real-world evidence to address the unique needs of people with opioid use disorder (OUD) in justice settings. Evidence regarding the economic value of OUD interventions in justice populations is limited. Moreover, the variation in economic study designs is a barrier to defining specific interventions as broadly cost-effective. The JCOIN Health Economics Analytic Team (HEAT) has worked closely with the Measures Committee to incorporate common economic measures and instruments across JCOIN studies, which will: a) ensure rigorous economic evaluations within each trial; b) enhance comparability of findings across studies; and c) allow for cross-study analyses of trials with similar designs/settings (e.g., pre-reentry MOUD), to assess questions beyond the scope of a single study, while controlling for and evaluating the effect of intervention-, organizational-, and population-level characteristics. We describe shared trial characteristics relevant to the economic evaluations, and discuss potential cross-study economic analyses

Community-Clinical Linkage Intervention to Improve Colorectal Cancer Screening Among Underserved Korean Americans

Background: Korean Americans report thae lowest and declined rates of colorectal cancer (CRC) screening, compared to general population in the United States. The present study aimed to evaluate the efficacy of a community-based multifaceted intervention designed to improve CRC screening among Korean Americans. Methods: A cluster-randomized trial involving 30 Korean church-based community organizations (n = 925) was conducted. Fifteen churches were assigned to intervention (n=470) and the other 15 to control (n = 455) groups. Main components of the intervention included interactive group education, patient navigation, physician engagement, and provision of fecal immunochemical test (FIT) kit. CRC screening rates were assessed at a 12-month follow-up. Results: Participants in the intervention group were significantly more likely to receive CRC screening (69.3%) as compared with those in the control group (16%). The intervention was particularly effective in promoting FIT among the more disadvantaged individuals in the Korean American community. Regression analysis revealed that controlling for the intervention effect, male gender, high school education, annual income of $20,000–40,000 were significantly associated with increased screening by FIT, whereas English inefficiency was significantly and lack of health insurance was marginally significantly associated with decreased screening by colonoscopy/sigmoidoscopy. Conclusion: Culturally and linguistically appropriate multifaceted intervention combining FIT provision with community-clinical linkage has a potential to be a cost-effective and practical approach to effectively targeting hard-to-reach disadvantaged minority populations and enhance CRC screening to reduce cancer disparities.&nbsp