Squaramides enhance NLRP3 inflammasome activation by lowering intracellular potassium

The NLRP3 inflammasome is a component of the inflammatory response to infection and injury, orchestrating the maturation and release of the pro-inflammatory cytokines interleukin-1β (IL-1β), IL-18, and triggering pyroptotic cell death. Appropriate levels of NLRP3 activation are needed to avoid excessive tissue damage while ensuring host protection. Here we report a role for symmetrical diarylsquaramides as selective K+ efflux-dependent NLRP3 inflammasome enhancers. Treatment of macrophages with squaramides potentiated IL-1β secretion and ASC speck formation in response to K+ efflux-dependent NLRP3 inflammasome activators without affecting priming, endosome cargo trafficking, or activation of other inflammasomes. The squaramides lowered intracellular K+ concentration which enabled cells to respond to a below-threshold dose of the inflammasome activator nigericin. Taken together these data further highlight the role of ion flux in inflammasome activation and squaramides as an interesting platform for therapeutic development in conditions where enhanced NLRP3 activity could be beneficial.

LRRC8A is essential for hypotonicity-, but not for DAMP-induced NLRP3 inflammasome activation

The NLRP3 inflammasome is a multi-molecular protein complex that converts inactive cytokine precursors into active forms of IL-1β and IL-18. The NLRP3 inflammasome is frequently associated with the damaging inflammation of non-communicable disease states and is considered an attractive therapeutic target. However, there is much regarding the mechanism of NLRP3 activation that remains unknown. Chloride efflux is suggested as an important step in NLRP3 activation, but which chloride channels are involved is still unknown. We used chemical, biochemical, and genetic approaches to establish the importance of chloride channels in the regulation of NLRP3 in murine macrophages. Specifically, we identify LRRC8A, an essential component of volume-regulated anion channels (VRAC), as a vital regulator of hypotonicity-induced, but not DAMP-induced, NLRP3 inflammasome activation. Although LRRC8A was dispensable for canonical DAMP-dependent NLRP3 activation, this was still sensitive to chloride channel inhibitors, suggesting there are additional and specific chloride sensing and regulating mechanisms controlling NLRP3.

Rural and urban differences in employment and vacancies in ten allied health professions

Few studies examine rural and urban differences in supply and demand for allied health professionals. This research examined ten allied health professions for rural and urban differences in employment and vacancies across four types of hospital settings. Based on data from a Georgia workforce study, significant differences in employment rates were noted for medical technologists, medical laboratory technicians, licensed practical nurses, registered nurses, and social workers. Significant size x location differences in vacancy rates were found for registered nurses and respiratory therapists. This study suggests that rurality and hospital size may impact levels of employment and vacancies in selected professions, and that a detailed workforce analysis is needed by profession, employment sector, and geographical area to establish a clear picture of health care services needed by the population.

Occupational therapy: a study of supply and demand in Georgia

In 1986 the University of Georgia's Institute of Higher Education conducted a statewide needs assessment of the supply of and demand for health care professionals in over 25 health care fields. Of the 638 hospitals, nursing homes, home health agencies, and freestanding ambulatory surgical centers surveyed, 321 replied (50%). Respondents reported that occupational therapy positions have one of the highest vacancy rates and pose severe recruitment difficulties. The occupational therapy vacancies in Georgia hospitals were 16.1% and averaged 15% in all surveyed facilities. In the hospital setting, the length of time needed to hire an occupational therapist ranged from 0 to 280 days with 3 months as average. Nevertheless, the respondents projected a 41% increase in employment of occupational therapists by 1995. Occupational therapy employment opportunities in Georgia far exceed the supply, and this imbalance will continue until the turn of the century. Although much publicity has been focused on the severe nursing shortage nationwide, in Georgia and apparently in other states, the shortage of occupational therapists is also severe. A concerted effort is required to turn this situation around.