Development of a novel angiotensin converting enzyme 2 stimulator with broad implications in SARS-CoV2 and type 1 diabetes.

Angiotensin-converting enzyme 2 (ACE2) is protective in cardiovascular disease, lung injury and diabetes yet paradoxically underlies our susceptibility to SARs-CoV2 infection and the fatal heart and lung disease it can induce. Furthermore, diabetic patients have chronic, systemic inflammation and altered ACE2 expression resulting in increased risk of severe COVID-19 and the associated mortality. A drug that could increase ACE2 activity and inhibit cellular uptake of severe acute respiratory syndrome coronavirus 2 (SARs-CoV2), thus decrease infection, would be of high relevance to cardiovascular disease, diabetes and SARs-CoV2 infection. While the need for such a drug lead was highlighted over a decade ago receiving over 600 citations,1 to date, no such drugs are available.2 Here, we report the development of a novel ACE2 stimulator, designated '2A'(international PCT filed), which is a 10 amino acid peptide derived from a snake venom, and demonstrate its in vitro and in vivo efficacy against SARs-CoV2 infection and associated lung inflammation. Peptide 2A also provides remarkable protection against glycaemic dysregulation, weight loss and disease severity in a mouse model of type 1 diabetes. No untoward effects of 2A were observed in these pre-clinical models suggesting its strong clinical translation potential.

Chronic Renin-Angiotensin System Activation Induced Neuroinflammation: Common Mechanisms Underlying Hypertension and Dementia?

Hypertension is a major risk factor for the pathogenesis of vascular dementia and Alzheimer's disease. Chronic activation of the renin-angiotensin system (RAS) contributes substantially to neuroinflammation. We propose that neuroinflammation arising from chronic RAS activation can initiate and potentiate the onset of hypertension and related dementia. Neuroinflammation induced by chronic activation of the RAS plays a key role in the pathogenesis of dementia. Increased levels of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and transforming growth factor (TGF)-ß have been reported in brain tissue of vascular dementia patients and animal models of vascular dementia induced by either angiotensin II infusion or transverse aortic coarctation. It is proposed that neuronal cell death and synaptic dysfunction induced by neuroinflammation lead to cognitive impairment in dementia. The neuroprotective RAS pathway, regulated by angiotensin-converting enzyme 2 (ACE2) which converts angiotensin II into angiotensin-(1-7), can attenuate hypertension and dementia. Furthermore, the use of anti-hypertensive medications in preventing dementia or cognitive decline in hypertensive patients and animal models of dementia have mostly been beneficial. Current evidence suggests a strong link between RAS induced neuroinflammation and the onset of hypertension and dementia, which warrants further investigation. Strategies to counteract an overactive RAS and enhance the neuroprotective arm of the RAS may help prevent or improve cognitive impairment associated with hypertension.

The Role of Gut Bacterial Metabolites in Brain Development, Aging and Disease.

In the last decade, emerging evidence has reported correlations between the gut microbiome and human health and disease, including those affecting the brain. We performed a systematic assessment of the available literature focusing on gut bacterial metabolites and their associations with diseases of the central nervous system (CNS). The bacterial metabolites short-chain fatty acids (SCFAs) as well as non-SCFAs like amino acid metabolites (AAMs) and bacterial amyloids are described in particular. We found significantly altered SCFA levels in patients with autism spectrum disorder (ASD), affective disorders, multiple sclerosis (MS) and Parkinson's disease (PD). Non-SCFAs yielded less significantly distinct changes in faecal levels of patients and healthy controls, with the majority of findings were derived from urinary and blood samples. Preclinical studies have implicated different bacterial metabolites with potentially beneficial as well as detrimental mechanisms in brain diseases. Examples include immunomodulation and changes in catecholamine production by histone deacetylase inhibition, anti-inflammatory effects through activity on the aryl hydrocarbon receptor and involvement in protein misfolding. Overall, our findings highlight the existence of altered bacterial metabolites in patients across various brain diseases, as well as potential neuroactive effects by which gut-derived SCFAs, p-cresol, indole derivatives and bacterial amyloids could impact disease development and progression. The findings summarized in this review could lead to further insights into the gut-brain-axis and thus into potential diagnostic, therapeutic or preventive strategies in brain diseases.

Impaired Pentose Phosphate Pathway in the Spinal Cord of the hSOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis.

Impairments in energy metabolism in amyotrophic lateral sclerosis (ALS) have long been known. However, the changes in the energy-producing pathways in ALS are not comprehensively understood. To investigate specific alterations in glucose metabolism in glycolytic, pentose phosphate, and TCA cycle pathways, we injected uniformly labeled [U-13C]glucose to wild-type and hSOD1G93A mice at symptom onset (80 days). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), levels of metabolites were determined in extracts of the cortex and spinal cord. In addition, the activities of several enzymes involved in glucose metabolism were quantified. In the spinal cord, the levels of pentose phosphate pathway (PPP) intermediate ribose 5-phosphate (p = 0.037) were reduced by 37% in hSOD1G93A mice, while the % 13C enrichments in glucose 6-phosphate were increased threefold. The maximal activities of the enzyme glucose 6-phosphate dehydrogenase were decreased by 24% in the spinal cord (p = 0.005), suggesting perturbations in the PPP. The total amount of pyruvate in the cortex (p = 0.039) was reduced by 20% in hSOD1G93A mice. Also, the activities of the glycolytic enzyme pyruvate kinase were reduced in the cortex by 31% (p = 0.002), indicating alterations in glycolysis. No significant differences were seen in the total amounts as well as % 13C enrichments in most TCA cycle intermediates, suggesting largely normal TCA cycle function. On the other hand, oxoglutarate dehydrogenase activity was decreased in the cortex, which may indicate increased oxidative stress. Overall, this study revealed decreased activity of the PPP in the spinal cord and alterations in glycolysis in hSOD1G93A mouse CNS tissues at the early symptomatic stage of disease.

Effect of Chlorhexidine Bathing Every Other Day on Prevention of Hospital-Acquired Infections in the Surgical ICU: A Single-Center, Randomized Controlled Trial.

OBJECTIVE: To test the hypothesis that compared with daily soap and water bathing, 2% chlorhexidine gluconate bathing every other day for up to 28 days decreases the risk of hospital-acquired catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection in surgical ICU patients. DESIGN: This was a single-center, pragmatic, randomized trial. Patients and clinicians were aware of treatment-group assignment; investigators who determined outcomes were blinded. SETTING: Twenty-four-bed surgical ICU at a quaternary academic medical center. PATIENTS: Adults admitted to the surgical ICU from July 2012 to May 2013 with an anticipated surgical ICU stay for 48 hours or more were included. INTERVENTIONS: Patients were randomized to bathing with 2% chlorhexidine every other day alternating with soap and water every other day (treatment arm) or to bathing with soap and water daily (control arm). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was a composite outcome of catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection. Of 350 patients randomized, 24 were excluded due to prior enrollment in this trial and one withdrew consent. Therefore, 325 were analyzed (164 soap and water versus 161 chlorhexidine). Patients acquired 53 infections. Compared with soap and water bathing, chlorhexidine bathing every other day decreased the risk of acquiring infections (hazard ratio = 0.555; 95% CI, 0.309-0.997; p = 0.049). For patients bathed with soap and water versus chlorhexidine, counts of incident hospital-acquired infections were 14 versus 7 for catheter-associated urinary tract infection, 13 versus 8 for ventilator-associated pneumonia, 6 versus 3 for incisional surgical site infections, and 2 versus 0 for primary bloodstream infection; the effect was consistent across all infections. The absolute risk reduction for acquiring a hospital-acquired infection was 9.0% (95% CI, 1.5-16.4%; p = 0.019). Incidences of adverse skin occurrences were similar (18.9% soap and water vs 18.6% chlorhexidine; p = 0.95). CONCLUSIONS: Compared with soap and water, chlorhexidine bathing every other day decreased the risk of acquiring infections by 44.5% in surgical ICU patients.