A Caspase-1 Biosensor to Monitor the Progression of Inflammation In Vivo.

Inflammasomes are multiprotein complexes that coordinate cellular inflammatory responses and mediate host defense. Following recognition of pathogens and danger signals, inflammasomes assemble and recruit and activate caspase-1, the cysteine protease that cleaves numerous downstream targets, including pro-IL-1ß and pro-IL-18 into their biologically active form. In this study, we sought to develop a biosensor that would allow us to monitor the initiation, progression, and resolution of inflammation in living animals. To this end, we inserted a known caspase-1 target sequence into a circularly permuted luciferase construct that becomes bioluminescent upon protease cleavage. This biosensor was activated in response to various inflammatory stimuli in human monocytic cell lines and murine bone marrow-derived macrophages. Next, we generated C57BL/6 transgenic mice constitutively expressing the caspase-1 biosensor. We were able to monitor the spatiotemporal dynamics of caspase-1 activation and onset of inflammation in individual animals in the context of a systemic bacterial infection, colitis, and acute graft-versus-host disease. These data established a model whereby the development and progression of inflammatory responses can be monitored in the context of these and other mouse models of disease.

Nucleoporin93 limits Yap activity to prevent endothelial cell senescence.

As the innermost lining of the vasculature, endothelial cells (ECs) are constantly subjected to systemic inflammation and particularly vulnerable to aging. Endothelial health is hence vital to prevent age-related vascular disease. Healthy ECs rely on the proper localization of transcription factors via nuclear pore complexes (NPCs) to govern cellular behavior. Emerging studies report NPC degradation with natural aging, suggesting impaired nucleocytoplasmic transport in age-associated EC dysfunction. We herein identify nucleoporin93 (Nup93), a crucial structural NPC protein, as an indispensable player in vascular protection. Endothelial Nup93 protein levels are significantly reduced in the vasculature of aged mice, paralleling observations of Nup93 loss when using in vitro models of EC senescence. The loss of Nup93 in human ECs induces cell senescence and promotes the expression of inflammatory adhesion molecules, where restoring Nup93 protein in senescent ECs reverses features of endothelial aging. Mechanistically, we find that both senescence and loss of Nup93 impair endothelial NPC transport, leading to nuclear accumulation of Yap and downstream inflammation. Pharmacological studies indicate Yap hyperactivation as the primary consequence of senescence and Nup93 loss in ECs. Collectively, our findings indicate that the maintenance of endothelial Nup93 is a key determinant of EC health, where aging targets endothelial Nup93 levels to impair NPC function as a novel mechanism of EC senescence and vascular aging.

Low-cost quantitative tool-tissue applied pressure indication method for surgical training and assessment in reality-based physical models.

We present a method of quantitatively measuring the pressure distribution applied to synthetic tissues by surgical tools via dye-impregnated microcapsules that rupture at specified pressures. A method utilizing pre-made indicator sheets is evaluated by force applications on synthetic bowel, and methods for creating paint-on indicator slurries were explored. A high spatial resolution of pressure intensity is demonstrated (0.1mm) and preliminary results merit further study.

Nucleoporin93 (Nup93) Limits Yap Activity to Prevent Endothelial Cell Senescence.

Endothelial cells (ECs) form the innermost lining of the vasculature and serve a pivotal role in preventing age-related vascular disease. Endothelial health relies on the proper nucleocytoplasmic shuttling of transcription factors via nuclear pore complexes (NPCs). Emerging studies report NPC degradation with natural aging, suggesting impaired nucleocytoplasmic transport in age-related EC dysfunction. We herein identify nucleoporin93 (Nup93), a crucial structural NPC protein, as an indispensable player for vascular protection. Endothelial Nup93 protein levels are significantly reduced in the vasculature of aged mice, paralleling observations of Nup93 loss when using in vitro models of endothelial aging. Mechanistically, we find that loss of Nup93 impairs NPC transport, leading to the nuclear accumulation of Yap and downstream inflammation. Collectively, our findings indicate maintenance of endothelial Nup93 as a key determinant of EC health, where aging targets endothelial Nup93 levels to impair NPC function as a novel mechanism for EC senescence and vascular aging.