Clark, Brian J.

Background While delivery of supplemental oxygen is a life-saving therapy, exposure to high oxygen, called hyperoxia, leads to increased intensive care unit mortality. Hyperoxia induces oxidant-mediated acute lung injury (ALI) and pulmonary cell death, called hyperoxic ALI (HALI). Elucidating molecular mechanisms in HALI could identify therapeutic targets in ALI. Methods In the current study, we examined in vivo effects of HALI on Beclin-1 (BCN1), which regulates autophagy, and modulation of BCN1 by epidermal growth factor receptor (EGFR). Effects of HALI on BCN1 and autophagy were examined in mice with genetically decreased EGFR (EGFR Wa5/+ ). Wildtype (WT) and EGFR Wa5/+ mice were exposed to 100% oxygen for 24–72 hours along with normoxia controls (eight groups; n=4–6/group), and analysis of pulmonary BCN1 and autophagy was completed. Results In WT, HALI led to increased BCN1 (59% increased total BCN1/β-Actin; p<0.01) in lung and alveolar epithelium (484% increased H-score; p<0.001). HALI led to decreased microtubule-associated protein 1B-light chain (LC3B)-II/-I ratios (43% decrease; p<0.05) and increased p62 (93% increase; p<0.05), suggesting reduced autophagic flux. In human alveolar type-II cells derived from induced pluripotent stem cells (AT2s iPSC ), HALI caused increased LDH release (130% increase; p<0.0001) and decreased LC3B-II/-I ratios (32% decrease; p<0.05). We previously showed that EGFR Wa5/+ mice are protected in HALI. In the current study, EGFR Wa5/+ mice showed increased pulmonary BCN1 (122% increase; p<0.05), reduced phosphorylated-(p-)/total BCN1 (47% decrease; p<0.05) and decreased LC3B-II/-I ratios (70% decrease; p<0.01) in HALI compared with WT. In addition, wortmannin (1 mg/kg), which decreases BCN1-mediated autophagy, increased mortality in HALI compared with vehicle control (n=10/group; 18% decreased hours survived; p<0.001). Conclusions These data delineate a novel cell death pathway in HALI involving BCN1 and EGFR with therapeutic potential.

Background: Fecal microbiota, live-jslm (RBL) is a microbiota-based product for the prevention of recurrent Clostridioides difficile infection (rCDI) in adults following antibiotic treatment. The safety and clinical effectiveness of RBL administered via colonoscopy in adults with rCDI were evaluated in CDI-SCOPE. An 8-week analysis showed 9.8% of participants had RBL-related treatment-emergent adverse events (TEAEs; primary endpoint) and 95.1% experienced treatment success (no CDI recurrence). Objectives: To evaluate long-term safety and clinical effectiveness of RBL through 6 months of follow-up in CDI-SCOPE. Design: Single-arm exploratory phase IIIb trial conducted at 12 sites in the United States. Methods: Eligible adults with rCDI received a single 150-mL dose of RBL to the right colon via colonoscopy. The primary endpoint was RBL-related TEAEs through 8 weeks after RBL administration or confirmed treatment failure. Secondary endpoints included safety up to 6 months after RBL administration. Exploratory analyses included assessment of further CDI episodes. Results: Of the 41 participants enrolled, 39 completed trial assessments through 6 months. From 8 weeks through 6 months after RBL administration, 36 TEAEs in 15 participants (36.6%) were reported, one of which (irritable bowel syndrome) was RBL-related; most TEAEs (97.2%) were of mild or moderate severity. Over the 6-month trial period, 23 participants (56.1%) experienced 69 TEAEs; 94.2% were of mild or moderate severity. Serious TEAEs occurred in three participants (7.3%), none of which were related to RBL or its administration, and no TEAEs led to discontinuation or death. Overall, 38 participants (92.7%) did not experience further CDI episodes, 1 (2.4%) did between 8 weeks and 6 months, and 2 (4.9%) had an indeterminate outcome due to trial withdrawal before 8 weeks. Conclusion: RBL administered via colonoscopy was safe and effective for preventing CDI recurrence in adults with rCDI in CDI-SCOPE. Trial registration: ClinicalTrials.gov: NCT05831189.

Background: Recurrent Clostridioides difficile infection (rCDI) occurs in up to 35% of patients with CDI, and further recurrence is common. Fecal microbiota, live-jslm (RBL) is safe and effective for preventing rCDI in adults following antibiotic treatment for rCDI when administered rectally. There is clinical interest in alternative routes of administration. Objectives: CDI-SCOPE assessed the safety and clinical effectiveness of RBL when administered via colonoscopy to adults with rCDI. Design: Single-arm, exploratory phase IIIb trial conducted at 12 sites in the United States. Methods: Eligible adults with rCDI received one administration of RBL consisting of one 150-mL dose of RBL, delivered via colonoscopy to the right side of the colon. The primary endpoint assessed RBL-related treatment-emergent adverse events (TEAEs) within 8 weeks of RBL administration or until confirmed treatment failure. Secondary endpoints included treatment success (absence of CDI recurrence for 8 weeks following RBL administration), physician experience administering RBL via colonoscopy, and physician perception of participant benefit. Results: Of 54 participants screened, 41 were enrolled and received RBL via colonoscopy; 39 participants completed the 8-week visit. Five TEAEs in four participants (9.8%) were assessed as related to RBL, all of which were gastrointestinal and mild in severity. Overall, 18 participants (43.9%) experienced 33 TEAEs within 8 weeks, most of which were of mild (25/33; 75.8%) or moderate (5/33; 15.2%) severity. No TEAEs led to intensive care unit admission or death. Overall, 39 participants (95.1%) experienced treatment success; 2 participants (4.9%) withdrew consent and had an indeterminate outcome. Among physicians, 90.2% of investigators indicated a “positive” or “very positive” experience administering RBL by colonoscopy. All physicians assessed participant benefit as “much” or “very much” improved. Conclusion: This single-arm study suggests RBL administered via colonoscopy is practical, safe, and effective for preventing CDI recurrence following antibiotic treatment in adults. Trial registration: ClinicalTrials.gov: NCT05831189.