The lipolytic activity of LipJ, a stress-induced enzyme, is regulated by its C-terminal adenylate cyclase domain.

Aim: The confirmation of lipolytic activity and role of Rv1900c in the Mycobacterium physiology Methods:rv1900c/N-terminus domain (rv1900NT) were cloned in pET28a/Escherichia coli, purified by affinity chromatography and characterized. Results: A zone of clearance on tributyrin-agar and activity with pNP-decanoate confirmed the lipolytic activity of Rv1900c. The Rv1900NT demonstrated higher enzyme specific activity, Vmax and kcat, but Rv1900c was more thermostable. The lipolytic activity of Rv1900c decreased in presence of ATP. Mycobacterium smegmatis expressed rv1900c/rv1900NT-altered colony morphology, growth, cell surface properties and survival under stress conditions. The effect was more prominent with Rv1900NT as compared with Rv1900c. Conclusion: The study confirmed the lipolytic activity of Rv1900c and suggested its regulation by the adenylate cyclase domain and role in the intracellular survival of bacteria.

Lay abstract Tuberculosis (TB) remains the top contagious/infectious killer in the world. It is caused by the bacteria Mycobacterium tuberculosis. The bacteria resides/replicates in the immune cell that normally has to eradicate infectious microorganisms. Though the treatment of TB is available, the emergence of drug-resistant bacteria is of major concern. The treatment of drug-resistant TB has been reported to be more difficult due to lengthy and complex treatment regimens. Therefore, there is an urgent need for new and better drugs to treat TB/drug-resistant TB. For this purpose understanding the role of each protein in the physiology of mycobacteria is required. Lipids play a critical role in the intracellular survival of this pathogen in the host. Our study demonstrated that LipJ supported the intracellular survival of bacteria. Therefore, it could be a potential drug target.

Clinical course and outcome among patients with acute pancreatitis and COVID-19.

BACKGROUND: The data on clinical course and outcome of acute pancreatitis among patients with coronavirus disease 2019 (COVID-19) are sparse. In this study, we analyzed the clinical profiles of patients with COVID 19 and acute pancreatitis. METHODS: This retrospective study was conducted on Research Patient Data Registry data which was pooled from five Mass General Brigham Healthcare Network hospitals. We extracted data on demographics, symptoms, ICU transfer, mechanical ventilation, laboratories' profiles, imaging findings, and patient outcomes. RESULT: Of 985 screened adult patients, 17 were eligible for the study, 9 (52.9%) were admitted primarily for respiratory failure and developed acute pancreatitis after a median of 22.5 days (13-76 days) from the onset of COVID-19 symptoms. On contrary, eight patients presented with typical symptoms and were diagnosed with acute pancreatitis, the majority with mild severity (62.5%) on admission. Patients who were admitted primarily with severe COVID-19 illness were younger (median age 57 vs. 63 years), females (55.6 vs. 25%), of Hispanic ethnicity (55.6 vs. 25%), and obese (88.9 vs. 37.5%). The median peak lipase, C reactive protein, ferritin, lactate dehydrogenase, D-dimer were higher among patients who developed acute pancreatitis later during hospitalization. Patients who developed acute pancreatitis later also experienced higher episodes of necrotizing pancreatitis (11.1% vs. 0), thromboembolic complications (55.6 vs. 12.5%), and higher mortality (37.5 vs. 12.5%). CONCLUSION: Acute pancreatitis is not common among patients with COVID-19. Patients with COVID-19 who had acute pancreatitis on admission had more benign course and overall better outcome as compared to the patients who developed acute pancreatitis during hospitalization.

Hyperlipasemia in absence of acute pancreatitis is associated with elevated D-dimer and adverse outcomes in COVID 19 disease.

BACKGROUND: Coronavirus SARS-CoV-2 affects multiple organs. Studies have reported mild elevations of lipase levels of unclear significance. Our study aims to determine the outcomes in patients with COVID-19 and hyperlipasemia, and whether correlation with D-dimer levels explains the effect on outcomes. METHODS: Case-control study from two large tertiary care health systems, of patients with COVID-19 disease admitted between March 1 and May 1, 2020 who had lipase levels recorded. Data analyzed to study primary outcomes of mortality, length of stay (LOS) and intensive care utilization in hyperlipasemia patients, and correlation with D-dimer and outcomes. RESULTS: 992 out of 5597 COVID-19 patients had lipase levels, of which 429 (43%) had hyperlipasemia. 152 (15%) patients had a lipase > 3x ULN, with clinical pancreatitis in 2 patients. Hyperlipasemia had a higher mortality than normal lipase patients (32% vs. 23%, OR = 1.6,95%CI = 1.2-2.1, P = 0.002). In subgroup analysis, hyperlipasemia patients had significantly worse LOS (11vs.15 days, P = 0.01), ICU admission rates (44% vs. 66%,OR = 2.5,95%CI = 1.3-5.0,P = 0.008), ICU LOS (12vs.19 days,P = 0.01), mechanical ventilation rates (34% vs. 55%,OR = 2.4,95%CI = 1.3-4.8,P = 0.01), and durations of mechanical ventilation (14 vs. 21 days, P = 0.008). Hyperlipasemia patients were more likely to have a D-dimer value in the highest two quartiles, and had increased mortality (59% vs. 15%,OR = 7.2,95%CI = 4.5-11,P < 0.001) and LOS (10vs.7 days,P < 0.001) compared to those with normal lipase and lower D-dimer levels. CONCLUSION: There is high prevalence of hyperlipasemia without clinical pancreatitis in COVID-19 disease. Hyperlipasemia was associated with higher mortality and ICU utilization, possibly explained by elevated D-dimer.