Objective Extracellular traps-(ETs) consist of DNA-protein-complexes formed following tissue injury contributes to the inflammatory and thrombosis cascades thereby exacerbating injury. Exogenous DNase-1 has been suggested as a therapeutic strategy to limit injury in the brain and myocardium.. These studies were designed to evaluate the effects of exogenous DNase-I treatment on skeletal muscle injury following acute hind limb ischemia-reperfusion (IR) injury in mice, and to determine whether neutrophils were a major source of ETs in postischemic muscle tissue. Methods C57BL6 mice were subjected to 1.5 hrs tourniquet ischemia and 24 hrs reperfusion with and without human recombinant DNase-I treatment. A separate set of mice was subjected to neutrophil depletion, followed by the same intervals of IR. Laser Doppler imaging and tissue harvesting was done at 24 hrs for assessment of limb perfusion, muscle fiber injury, ATP, markers of inflammation, thrombosis, and ETs formation. Results DNase-I treatment significantly reduced ETs detection in post-ischemic muscle but did not alter skeletal muscle fiber injury, levels of pro-inflammatory molecules or ATP. DNase-I treatment did enhance postischemic hind limb perfusion, decreased infiltrating inflammatory cells and reduced the expression of Thrombin-Anti-Thrombin-III. Neutrophil depletion resulted in a significant yet small reduction in ETs in the post ischemic muscle. Neutrophil depletion did not alter skeletal muscle fiber injury, hind limb perfusion, or ATP levels. Conclusions These data suggest that neither DNase-I treatment nor Neutrophil depletion were protective against IR injury, even though both decreased ETs detection in skeletal muscle following IR. Neutrophils are not the only source of ETs following IR.

Background Obesity is a major risk factor for the development of diabetes. Limb ischemia reperfusion injury (IR) is a common clinical problem in diabetics who have compromised lower extremity perfusion. This study compared the histologic, metabolic and functional outcomes following hindlimb IR in diet-induced obese(DIO) and non-diabetic (ND) mice during the acute and the regenerative phases of IR. Methods DIO and ND mice were subjected to 1.5hrs unilateral hindlimb ischemia followed by 1 or 28 days IR. Muscle morphology, metabolic and genomic stress was evaluated at day 1 and 28 IR; Acute inflammation and thrombosis were only measured at day 1 IR. At day 28 IR, skeletal muscle contractility and maturation was also assessed. Results At day 1 IR, similar levels of acute muscle fiber necrosis were seen in both groups. DIO mice demonstrated substantially greater inflammatory, pro-thrombotic, and genomic stress responses which were also associated with a greater reduction in energy substrates and Akt phosphorylation. At 28 days, there was no difference in the peak forces generated in the hindlimbs for the two groups. DIO mice had reduced fatigue resistance compared to ND and larger areas of fat accumulation even though there was no significant difference in muscle fiber maturation. Conclusion DIO mice had an exacerbated acute response to IR with enhanced metabolic deficit, fat accumulation and defective functional recovery during the regenerative phase of IR. These changes in fatigue resistance reflect compromised functional recovery following IR injury and have relevance for the functional recovery of patients with metabolic syndrome and insulin resistance.

Cell migration is vital to many physiological and pathological processes including tissue development, repair, and regeneration, cancer metastasis, and inflammatory responses. Given the current interest in the role of mesenchymal stromal cells in mediating tissue repair, we are interested in quantifying the migratory capacity of these cells, and understanding how migratory capacity may be altered after damage. Optimization of a rigorously quantitative migration assay that is both easy to customize and cost-effective to perform is key to answering questions concerning alterations in cell migration in response to various stimuli. Current methods for quantifying cell migration, including scratch assays, trans-well migration assays (Boyden chambers), micropillar arrays, and cell exclusion zone assays, possess a range of limitations in reproducibility, customizability, quantification, and cost-effectiveness. Despite its prominent use, the scratch assay is confounded by issues with reproducibility related to damage of the cell microenvironment, impediments to cell migration, influence of neighboring senescent cells, and cell proliferation, as well as lack of rigorous quantification. The optimized scratch assay described here demonstrates robust outcomes, quantifiable and image-based analysis capabilities, cost-effectiveness, and adaptability to other applications. Video LinkThe video component of this article can be found at

The physiological risks of organ transplantation are well documented, but more poorly understood are the sociological ways in which organ recipients redefine themselves in reaction to physiological risks and social changes accompanying transplantation. This article analyses transplantation as a procedure that is not only physiologically risky but also poses risk to the social identity of the recipient, and explores how transplant recipients cognitively navigate transplantation surgery from waiting for to recovering after a transplant. It builds on previous sociological exploration of risk as a socially constructed process mediating experiences of health and illness with a focused contribution on explaining how individuals navigate risks posed to their social identities by major biophysical transformations. This article pointedly analyses narratives of fourteen organ recipients and the four dominant phases of identity management that emerged to create what we have coined as the new 'transplanted self', indicating the varied ways the individual social self emerges in response to the social risks of transplantation. We conclude that a better understanding of the recipient experience will contribute to improved care in the transplantation field.