Protective effects of fatty acid amide hydrolase inhibition in UVB-activated microglia.

Neuroinflammation is a hallmark of several neurodegenerative disorders that has been extensively studied in recent years. Microglia, the primary immune cells of the central nervous system (CNS), are key players in this physiological process, demonstrating a remarkable adaptability in responding to various stimuli in the eye and the brain. Within the complex network of neuroinflammatory signals, the fatty acid N-ethanolamines, in particular N-arachidonylethanolamine (anandamide, AEA), emerged as crucial regulators of microglial activity under both physiological and pathological states. In this study, we interrogated for the first time the impact of the signaling of these bioactive lipids on microglial cell responses to a sub-lethal acute UVB radiation, a physical stressor responsible of microglia reactivity in either the retina or the brain. To this end, we developed an in vitro model using mouse microglial BV-2 cells. Upon 24 h of UVB exposure, BV-2 cells showed elevated oxidative stress markers and, cyclooxygenase (COX-2) expression, enhanced phagocytic and chemotactic activities, along with an altered immune profiling. Notably, UVB exposure led to a selective increase in expression and activity of fatty acid amide hydrolase (FAAH), the main enzyme responsible for degradation of fatty acid ethanolamides. Pharmacological FAAH inhibition via URB597 counteracted the effects of UVB exposure, decreasing tumor necrosis factor α (TNF-α) and nitric oxide (NO) release and reverting reactive oxidative species (ROS), interleukin-1ß (IL-1ß), and interleukin-10 (IL-10) levels to the control levels. Our findings support the potential of enhanced fatty acid amide signaling in mitigating UVB-induced cellular damage, paving the way to further exploration of these lipids in light-induced immune responses.

Cellular and Molecular Effects of Microgravity on the Immune System: A Focus on Bioactive Lipids.

Microgravity is one of the main stressors that astronauts are exposed to during space missions. This condition has been linked to many disorders, including those that feature dysfunctional immune homeostasis and inflammatory damage. Over the past 30 years, a significant body of work has been gathered connecting weightlessness-either authentic or simulated-to an inefficient reaction to pathogens, dysfunctional production of cytokines and impaired survival of immune cells. These processes are also orchestrated by a plethora of bioactive lipids, produced by virtually all cells involved in immune events, which control the induction, magnitude, outcome, compartmentalization and trafficking of immunocytes during the response to injury. Despite their crucial importance in inflammation and its modulation, however, data concerning the role of bioactive lipids in microgravity-induced immune dysfunctions are surprisingly scarce, both in quantity and in variety, and the vast majority of it focuses on two lipid classes, namely eicosanoids and endocannabinoids. The present review aims to outline the accumulated knowledge addressing the effects elicited by microgravity-both simulated and authentic-on the metabolism and signaling of these two prominent lipid groups in the context of immune and inflammatory homeostasis.

Simulated Microgravity Affects Pro-Resolving Properties of Primary Human Monocytes.

Space-related stressors such as microgravity are associated with cellular and molecular alterations of the immune and inflammatory homeostasis that have been linked to the disorders that astronauts suffer from during their missions. Most of the research of the past 30 years has consistently established that innate adaptive immune cells represent a target of microgravity, which leads to their defective or dysfunctional activation, as well as to an altered ability to produce soluble mediators-e.g., cytokines/chemokines and bioactive lipids-that altogether control tissue homeostasis. Bioactive lipids include a vast array of endogenous molecules of immune origin that control the induction, intensity and outcome of the inflammatory events. However, none of the papers published so far focus on a newly characterized class of lipid mediators called specialized pro-resolving mediators (SPMs), which orchestrate the "resolution of inflammation"-i.e., the active control and confinement of the inflammatory torrent mostly driven by eicosanoids. SPMs are emerging as crucial players in those processes that avoid acute inflammation to degenerate into a chronic event. Given that SPMs, along with their metabolism and signaling, are being increasingly linked to many inflammatory disorders, their study seems of the outmost importance in the research of pathological processes involved in space-related diseases, also with the perspective of developing therapeutic countermeasures. Here, we show that microgravity, simulated in the rotary cell culture system (RCCS) developed by NASA, rearranges SPM receptors both at the gene and protein level, in human monocytes but not in lymphocytes. Moreover, RCCS treatment reduces the biosynthesis of a prominent SPM like resolvin (Rv) D1. These findings strongly suggest that not only microgravity can impair the functioning of immune cells at the level of bioactive lipids directly involved in proper inflammation, but it does so in a cell-specific manner, possibly perturbing immune homeostasis with monocytes being primary targets.

Satisfaction with telemedicine-delivered inflammatory bowel disease care depends on disease activity, personality and economic factors.

Objective: Patients with inflammatory bowel disease (IBD) traditionally receive follow-up care at face-to-face outpatient clinics. During the COVID-19 pandemic, gastroenterology societies recommended IBD clinics to be carried out remotely where possible using telephone or telemedicine-delivered virtual clinics. Previous studies have demonstrated patient satisfaction with virtual clinics but few studies have examined factors that impact satisfaction or assessed patient's personal perception of the virtual clinic experience. Design/method: Patients who had their IBD clinic appointment changed from face-to-face to telephone virtual clinic completed a questionnaire relating to their clinical experience and preference for future care. Qualitative data were also collected and evaluated using content analysis to identify major themes associated with the patient experience. Results: 141 patients were included for analysis. The virtual clinic satisfaction questionnaire was found to be valid while patients expressed high-satisfaction levels with virtual clinics (median satisfaction score 18, range 0-20). Multivariate analysis identified open personality type (p=0.004), short disease duration (p=0.047) and higher cost to attend clinic (p=0.047) as predictors of high-satisfaction levels, with active disease (p=0.035) and an agreeable personality type (p=0.042) associated with low satisfaction levels. Content analysis of the qualitative data identified three major themes connected to virtual clinic convenience, lack of physical interaction and disease activity. Conclusion: Patients expressed high levels of satisfaction with telemedicine-delivered IBD clinics, with most wishing to continue their use. Personality type should be recognised as an important variable affecting clinical satisfaction, in addition to socioeconomic and disease-related factors.

Brief and Telehealth Acceptance and Commitment Therapy (ACT) Interventions for Stress in Inflammatory Bowel Disease (IBD): A Series of Single Case Experimental Design (SCED) Studies.

Psychological intervention targeting distress is now considered an integral component of inflammatory bowel disease (IBD) management. However, significant barriers to access exist which necessitate the development of effective, economic, and accessible brief and remote interventions. Acceptance and commitment therapy (ACT) is a therapy with demonstrated acceptability and a growing evidence base for the treatment of distress in IBD populations. The present paper trialled two brief ACT interventions via randomized multiple baseline designs. Study 1 trialled a single-session ACT intervention (delivered face-to-face and lasting approximately two hours) targeting stress and experiential avoidance, respectively. Participants were seven people with an IBD diagnosis who presented with moderate to extremely severe stress (five females, two males; M age = 39.57, SD = 5.74). The findings of study 1 indicate that a single-session ACT intervention represented an insufficient dosage to reduce stress and experiential avoidance. Study 2 investigated a brief telehealth ACT intervention (delivered via a video conferencing platform and lasting approximately four hours) targeting stress and increased psychological flexibility. Participants (N = 12 people with an IBD diagnosis and mild to extremely severe stress) completed baselines lasting from 21 to 66 days before receiving a two-session ACT telehealth intervention supplemented by a workbook and phone consultation. Approximately half of participants experienced reduced stress, increased engagement in valued action, and increased functioning. Despite shortcomings such as missing data and the context of COVID-19, the present findings suggest that brief ACT interventions in this population may be effective and economic, though further research and replications are necessary.

Microglial Endocannabinoid Signalling in AD.

Chronic inflammation in Alzheimer's disease (AD) has been recently identified as a major contributor to disease pathogenesis. Once activated, microglial cells, which are brain-resident immune cells, exert several key actions, including phagocytosis, chemotaxis, and the release of pro- or anti-inflammatory mediators, which could have opposite effects on brain homeostasis, depending on the stage of disease and the particular phenotype of microglial cells. The endocannabinoids (eCBs) are pleiotropic bioactive lipids increasingly recognized for their essential roles in regulating microglial activity both under normal and AD-driven pathological conditions. Here, we review the current literature regarding the involvement of this signalling system in modulating microglial phenotypes and activity in the context of homeostasis and AD-related neurodegeneration.