ACE and ACE2 catalytic activity in the fecal content along the gut.

BACKGROUND: Angiotensin-converting enzyme (ACE) and ACE2 are two major enzymes of the renin-angiotensin-aldosterone system (RAAS), which control the formation/degradation of angiotensin (Ang) II and Ang1-7, regulating their opposite effects. We aimed at evaluating the catalytic activity of ACE and ACE2 in the intestinal content and corresponding intestinal tissue along the gut of Wistar Han rats. METHODS: Portions of the ileum, cecum, proximal colon, and distal colon, and the corresponding intestinal content were collected from Wistar Han rats. Enzyme activity was evaluated by fluorometric assays using different substrates: Hippuryl-His-Leu for ACE-C-domain, Z-Phe-His-Leu for ACE-N-domain, and Mca-APK(Dnp) for ACE2. ACE and ACE2 concentration was assessed by ELISA. Ratios concerning concentrations and activities were calculated to evaluate the balance of the RAAS. Statistical analysis was performed using Friedman test followed by Dunn's multiple comparisons test or Wilcoxon matched-pairs test whenever needed. KEY RESULTS: ACE and ACE2 are catalytically active in the intestinal content along the rat gut. The ACE N-domain shows higher activity than the C-domain both in the intestinal content and in the intestinal tissue. ACE and ACE2 are globally more active in the intestinal content than in the corresponding intestinal tissue. There was a distal-to-proximal prevalence of ACE2 over ACE in the intestinal tissue. CONCLUSIONS & INFERENCES: This work is the first to report the presence of catalytically active ACE and ACE2 in the rat intestinal content, supporting future research on the regulatory role of the intestinal RAAS on gut function and a putative link to the microbiome.

The impact of the second wave of COVID-19 on liaison psychiatry: a comparative retrospective study with the homologous non-pandemic period.

OBJECTIVE: To determine the impact of COVID-19 pandemic (COVID-19-P) on clinical and health organisational variables of patients evaluated by Liaison Psychiatry (LP). METHODS: Revision of all collaboration requests (CR) to LP for patients hospitalised in a Portuguese General Hospital during the second wave of COVID-19-P, from 1 October to 31 December of 2020. Medical charts were analysed and selected variables were compared with those of the homologous non-pandemic period. Data were statistically analysed. RESULTS: There was a 22.3% decrease in the number of CR in 2020. The most frequently given reasons for CR were depressive symptoms, psychomotor agitation, and difficulties in adapting to the disease in both years. However, 5.9% more patients reported suicidal ideation in 2020. The hospitalisation length before CR was smaller in 2020 than in 2019 (9 vs 11). There was a higher proportion of patients followed in a psychiatric consultation and previously taking psychotropic medication before hospitalisation in 2020 than in 2019. After the assessment, the trend was that both groups did not meet diagnostic criteria for any disorder and no pharmacological adjustment was needed. CONCLUSION: This study highlights the need to better characterise the indirect repercussion of COVID-19-P, and focus on the prevention and treatment of mental illness particularly in adverse contexts.Key PointsFewer collaboration requests to liaison psychiatry during the second wave of COVID-19;Collaboration requests were made earlier in the hospitalisation;For patients with more medical comorbidities, psychiatric history, and psychotropic medication;Most because of depressive symptoms and more with suicidal ideation;Fewer collaboration requests to liaison psychiatry during COVID-19;Made earlier in the hospitalisation;For patients with more medical comorbidities, psychiatric history, and medication;Most because of depressive symptoms and more with suicidal ideation.

Unraveling the Role of ACE2, the Binding Receptor for SARS-CoV-2, in Inflammatory Bowel Disease.

Angiotensin-converting enzyme 2 (ACE2) has been highlighted for its role as a receptor for SARS-CoV-2, responsible for the current COVID-19 pandemic. This review summarizes current knowledge about ACE2 as a multifunctional protein, focusing on its relevance in inflammatory bowel disease (IBD). As an enzyme, ACE2 may be protective in IBD because it favors the counter-regulatory arm of the renin-angiotensin system or deleterious because it metabolizes other anti-inflammatory/repairing elements. Meanwhile, as a receptor for SARS-CoV-2, the impact of ACE2 expression/activity on infection is still under debate because no direct evidence has been reported and, again, both protective and deleterious pathways are possible. Research has shown that ACE2 regulates the expression of the neutral amino acid transporter B0AT1, controlling tryptophan-associated intestinal inflammation and nutritional status. Finally, intact membrane-bound or shed soluble ACE2 can also trigger integrin signaling, modulating the response to anti-integrin biologic drugs used to treat IBD (such as vedolizumab) and fibrosis, a long-term complication of IBD. As such, future studies on ACE2 expression/activity in IBD can improve monitoring of the disease and explore an alternative pharmacological target.