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Type 2 diabetes involves insulin resistance and β-cell failure leading to inadequate insulin secretion. An important component of β-cell failure is cell loss by apoptosis. Apoptosis repressor with caspase recruitment domain (ARC) is an inhibitor of apoptosis that is expressed in cardiac and skeletal myocytes and neurons. ARC possesses the unusual property of antagonizing both the extrinsic (death receptor) and intrinsic (mitochondria/endoplasmic reticulum [ER]) cell death pathways. Here we report that ARC protein is abundant in cells of the endocrine pancreas, including >99.5% of mouse and 73% of human β-cells. Using genetic gain- and loss-of-function approaches, our data demonstrate that ARC inhibits β-cell apoptosis elicited by multiple inducers of cell death, including ER stressors tunicamycin, thapsigargin, and physiological concentrations of palmitate. Unexpectedly, ARC diminishes the ER stress response, acting distal to protein kinase RNA-like ER kinase (PERK) and inositol-requiring protein 1α, to suppress C/EBP homologous protein (CHOP) induction. Depletion of ARC in isolated islets augments palmitate-induced apoptosis, which is dramatically rescued by deletion of CHOP. These data demonstrate that ARC is a previously unrecognized inhibitor of apoptosis in β-cells and that its protective effects are mediated through suppression of the ER stress response pathway.

The Surviving Sepsis Campaign recommends immediate antibiotics for all patients with suspected sepsis and septic shock, ideally within 1 hour of recognition. Immediate antibiotic treatment is lifesaving for some patients, but a substantial fraction of patients initially diagnosed with sepsis have noninfectious conditions. Aggressive time-to-antibiotic targets risk promoting antibiotic overuse and antibiotic-associated harms for this subset of the population. An accurate understanding of the precise relationship between time-to-antibiotics and mortality for patients with possible sepsis is therefore critical to finding the best balance between assuring immediate antibiotics for those patients who truly need them versus allowing clinicians some time for rapid investigation to minimize the risk of overtreatment and antibiotic-associated harms for patients who are not infected. More than 30 papers have been published assessing the relationship between time-to-antibiotics and outcomes, almost all of which are observational cohort studies. Most report significant associations but all have important limitations. Key limitations include focusing just on the sickest subset of patients (only patients requiring intensive care and/or patients with septic shock), blending together mortality estimates from patients with very long intervals until antibiotics with patients with shorter intervals and reporting a single blended (and thus inflated) estimate for the average increase in mortality associated with each hour until antibiotics, and failure to control for large potential confounders including patients’ presenting signs and symptoms and granular measures of comorbidities and severity of illness. In this study, we elaborate on these potential sources of bias and try to distill a better understanding of what the true relationship between time-to-antibiotics and mortality may be for patients with suspected sepsis or septic shock.

Blockade of the inflammatory cytokine tumor necrosis factor (TNF) in depressed patients with increased inflammation has been associated with decreased depressive symptoms. Nevertheless, the impact of TNF blockade on sleep in depressed patients has not been examined. Accordingly, sleep parameters were measured using polysomnography in 36 patients with treatment resistant major depression at baseline and 2 weeks after 3 infusions (week 8) of either the TNF antagonist infliximab (n=19) or placebo (n=17). Markers of inflammation including c-reactive protein (CRP) and TNF and its soluble receptors were assessed along with depression measured by the 17-item Hamilton Depression Rating Scale. No differences in sleep parameters were found as a function of infliximab treatment over time. Nevertheless, Wake After Sleep Onset (WASO), the spontaneous arousal index and sleep period time significantly decreased, and sleep efficiency significantly increased, from baseline to week 8 in infliximab-treated patients with high (CRP>5mg/L)(n=9) versus low inflammation (CRP≤5mg/L)(n=10), controlling for changes in scores of depression. Stage 2 sleep also significantly decreased in infliximab-treated patients with high versus low inflammation. Decreases in soluble TNF receptor 1 significantly correlated with decreases in WASO and increases in sleep efficiency in infliximab-treated subjects with high inflammation. Placebo-treated subjects exhibited no sleep changes as a function of inflammation, and no correlations between inflammatory markers and sleep parameters in placebo-treated patients were found. These data suggest that inhibition of inflammation may be a viable strategy to improve sleep alterations in patients with depression and other disorders associated with increased inflammation.

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Spinal neuronal mechanisms regulate recovered involuntary micturition after spinal cord injury (SCI). It is recently discovered that dopamine (DA) is synthesized in the rat injured spinal cord and is involved in lower urinary tract (LUT) activity. To fully understand the role of spinal DA-ergic machinery in micturition, we examined urodynamic responses in female rats during pharmacological modulation of the DA pathway. Three to four weeks after complete thoracic SCI, L-DOPA administered intravenously during bladder cystometrogram and external urethral sphincter (EUS) electromyography reduced bladder overactivity and increased the duration of EUS bursting, leading to remarkably improved voiding efficiency. Apomorphine, a non-selective dopamine receptor (DR) agonist, or quinpirole, a selective DR 2 agonist, induced similar responses whereas a specific DR 2 antagonist remoxipride alone only had minimal effects. Meanwhile, administration of SCH 23390, a DR 1 antagonist, reduced voiding efficiency by increasing tonic EUS activity and shortening the EUS bursting period. Unexpectedly, SKF 38393, a selective DR 1 agonist, increased EUS tonic activity, implying a complicated role of DR 1 in LUT function.In metabolic cage assays, subcutaneous administration of quinpirole decreased spontaneous voiding frequency and increased voiding volumes; while L-DOPA and apomorphine were inactive possibly due to slow entry into the CNS. Collectively, tonically active DR 1 in SCI rats inhibits urine storage and enhances voiding by differentially modulating the EUS tonic and bursting patterns, respectively; while pharmacologic activation of DR 2 which are normally silent improves voiding by enhancing EUS bursting. Thus, enhancing DA signaling achieves better detrusor-sphincter coordination to facilitate micturition function in SCI rats.