Spironolactone rescues renal dysfunction in obstructive jaundice rats by upregulating ACE2 expression

FXR contributes to obstructive jaundice-induced vascular hyporeactivity in mesenteric arteries by reconstituting BKCa channels

OBJECTIVE

Vascular hyporeactivity increases with the incidence of obstructive jaundice (OJ). Evidence suggests that OJ activates the farnesoid X receptor (FXR) as well as the large-conductance Ca2+-activated K+ (BKCa or MaxiK) channel. This study was designed to explore the role of the FXR in vascular hyporesponsiveness induced by cholestasis.

METHODS

The OJ model rats were constructed by bile duct ligation (BDL) and treated with an FXR agonist or antagonist. Vasoconstriction of the mesenteric arteries (MAs) was assessed in vitro. Whole-cell patch clamp recordings were used to investigate BKCa channel function. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot were used to detect mRNA and protein levels.

RESULTS

A significant increase in vascular tone and responsiveness to norepinephrine (NE) was observed after the MaxiK channel blocker (IbTX) was administered. This effect was pronounced in BDL animals and can be mimicked by the FXR agonist GW4064 and inhibited by the FXR antagonist Z-guggulsterone (Z-Gu). GW4064 has a similar effect as cholestasis in promoting MaxiK currents in isolated arterial smooth muscle cells (ASMCs), while Z-Gu blunted this effect. The mRNA and protein expression of FXR and MaxiK-β1, but not MaxiK-α, were significantly increased in the BDL group in comparison to the sham. Furthermore, activation or inhibition of FXR promoted or inhibited the mRNA and protein expression of the MaxiK-β1 subunit, respectively.

CONCLUSION

Activation of FXR enhances the capability of the MaxiK channel to regulate vascular tone and leads to vascular hyporesponsiveness in the MAs of BDL rats, which may be mediated by the nonparallel upregulation of MaxiK-α and MaxiK-β1 subunit expression.

Lymphocytes regulate expression of the SARS-CoV-2 cell entry factor ACE2 in the pancreas of T2DM patients

AIMS

COVID-19 patients with type 2 diabetes mellitus (T2DM) show both poorer clinical outcomes and have an increased risk of death. SARS-CoV-2 virus infection requires simultaneous expression of the SARS-CoV-2 cell entry factors angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine type 2 (TMPRSS2) in the same cell. The aim of the study was to explore the underlying mechanisms of a COVID-19 infection in patients with T2DM.

METHODS

The distribution and expression of AEC2 and TMPRSS2 in different pancreatic cell types in clinical samples of T2DM patients and diabetic mouse models were analysed by single-cell sequencing, bioinformatics analysis and basic experiments.

RESULTS

The results showed that ACE2 and TMPRSS2 are expressed in the ducts of the human pancreas. These findings suggest that SARS-CoV-2 can infect ductal cells in vivo through ACE2 and TMPRSS2. T2DM can promote the co-expression of ACE2 and TMPRSS2 in exocrine ducts, including in the human pancreas. We hypothesize that ACE2 expression levels are associated with increased numbers of lymphocytes in vivo.

CONCLUSIONS

Increased blood glucose levels are associated with increased ACE2 expression and an increased number of lymphocytes. At the same time, lymphocytes can promote ACE2 expression.

Exploration of sodium homeostasis and pharmacokinetics in bile duct-ligated rats treated by anti-cirrhosis herbal formula plus spironolactone

Renal sodium retention is an essential indicator that is used for the prognosis of cirrhosis with ascites that requires diuretic treatment to restore sodium homeostasis. The diuretic effects of Yin-Chen-Hao-Tang (YCHT) alone or in combination with diuretics for sodium retention in patients with cirrhosis have not been investigated. This study aimed to investigate the diuretic effects and sodium retention caused by YCHT with spironolactone, from both the pharmacokinetic and pharmacodynamic perspective, in bile duct-ligated rats. The HPLC method was validated and utilized for the pharmacokinetic analysis of rat urine. Urine samples were collected and analyzed every 4 hours for 32 h after oral administration of YCHT at 1 or 3 g/kg daily for 5 days in bile duct-ligated rats. A dose of 20 mg/kg spironolactone was also administered to pretreat the YCHT 1 g/kg or the 3 g/kg group on the 5th day to explore the interaction of the two treatments. Urine sodium, potassium, weight, volume, and spironolactone and canrenone levels were measured to investigate fluid homeostasis after the coadministration. The linearity, precision, and accuracy of the HPLC method were suitable for subsequent urinary pharmacokinetic analyses. The pharmacokinetic parameters in the 1 g/kg YCHT with spironolactone group revealed that the elimination half-life of the spironolactone metabolite, canrenone, was prolonged. In addition, the cumulative excretion amount, the area under the rate curve (AURC), and the maximum rate of excretion (Rmax) were significantly decreased when the spironolactone group was pretreated with 3 g/kg YCHT. Urinary sodium excretion elicited by spironolactone was suppressed by pretreatment with 1 or 3 g/kg YCHT. The 32-hour urine output was not altered by the administration of YCHT alone, but it was significantly decreased by 64.9% after the coadministration of YCHT with spironolactone. The interaction of spironolactone and YCHT was found to decrease urine sodium-potassium and water excretion, and this change was attributed to the decreased level of spironolactone metabolites and possibly the regulation of the renin-angiotensin-aldosterone system by obstructed cirrhosis. The dose adjustment of YCHT or diuresis monitoring should be noted when co-administering YCHT and spironolactone to treat hepatic diseases clinically.

[Angiotensin-converting enzyme 2 particapates in ozone-induced lung inflammation and airway remodeling in mice]

OBJECTIVE

To investigate the roles of angiotensin-converting enzyme 2 (ACE2) in ozone-induced pulmonary inflammation and airway remodeling in mice.

METHODS

Sixteen wild-type (WT) C57BL/6J mice and 16 ACE2 knock-out (KO) mice were exposed to either filtered air or ozone (0.8 ppm) for 3 h per day for 5 consecutive days. Masson's staining and HE staining were used to observe lung pathologies. Bronchoalveolar lavage fluid (BALF) was collected and the total cell count was determined. The total proteins and cytokines in BALF were determined by BCA and ELISA method. The transcription levels of airway remodeling-related indicators in the lung tissues were detected using real-time quantitative PCR. The airway resistance of the mice was measured using a small animal ventilator with methacholine stimulation.

RESULTS

Following ozoneexposure ACE2 KO mice had significantly higher lung pathological scores than WT mice (P < 0.05). Masson staining results showed that compared with ozone-exposed WT mice, ozone-exposed ACE2 KO mice presented with significantly larger area of collagen deposition in the bronchi [(19.62±3.16)% vs (6.49±1.34)%, P < 0.05] and alveoli [(21.63±3.78)% vs (4.44±0.99)%, P < 0.05]. The total cell count and total protein contents in the BALF were both higher in ozone-exposed ACE2 KO mice than in WT mice, but these differences were not statistically significant (P > 0.05). The concentrations of IL-6, IL-1β, TNF-α, CXCL1/KC and MCP-1 in the BALF were all higher in ozone-exposed ACE2 KO mice than in ozone-exposed WT mice, but only the difference in IL-1β was statistically significant (P < 0.05). The transcription levels of MMP-9, MMP-13, TIMP 4, COL1A1, and TGF-β in the lung tissues were all significantly higher in ozone-exposed ACE2 KO mice (P < 0.01). No significant difference was found in airway resistance between ozone-exposed ACE KO mice and WT mice after challenge with 0, 10, 25, or 100 mg/mL of methacholine.

CONCLUSION

ACE2 participates in ozone-induced lung inflammation and airway remodeling in mice.

Perfusion Analysis of Kidney Injury in Rats With Cirrhosis Induced by Common Bile Duct Ligation Using Arterial Spin Labeling MRI

BACKGROUND

Arterial spin labeling (ASL) has been proven to be effective in ischemia-induced acute kidney injury (AKI); however, validation of ASL magnetic resonance imaging (MRI) is limited in AKI in the presence of cirrhosis.

PURPOSE

To investigate the feasibility of ASL in revealing renal blood flow (RBF) changes in kidney injury in the presence of cirrhosis and to assess its value in the early diagnosis of disease.

STUDY TYPE

Longitudinal.

ANIMAL MODEL

Rats were randomized into baseline group (N = 3), sham surgery group (N = 18), and common bile duct ligation (BDL) group (N = 48). All groups were divided into six subgroups based on different sacrificed time points.

FIELD STRENGTH/SEQUENCE

3 T scanner, prototypic pulsed ASL sequence using flow-sensitive alternating inversion recovery preparation, half-Fourier acquisition single-shot turbo spin echo sequence.

ASSESSMENT

RBF measurement was performed by ASL. Hematoxylin-eosin (HE) score, Hypoxia-inducible factor-1alpha (HIF-1α) score, peritubular capillar (PTC) density, alanine aminotransferase, aspartate aminotransferase, serum total bilirubin, total bile acids, serum creatinine (Scr), and blood urea nitrogen (BUN) were harvested.

STATISTICAL TESTS

Analysis of variance, Pearson's correlation coefficient, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant.

RESULTS

RBF, HE score, HIF-1α score, and PTC density after BDL were significantly different from baseline. RBF was highly correlated with HE score, HIF-1α score, and PTC density (r = -0.7598, r = -0.7434, r = 0.6406, respectively). RBF and Scr began to differ significantly from baseline at day 3 and 7 after intervention, respectively. The areas under the curves of RBF, Scr, and BUN for distinguishing non-AKI from AKI in cirrhosis were 1.00, 0.888, and 0.911, while those for distinguishing mild from severe kidney injury were 0.961, 0.830, and 0.857, respectively.

DATA CONCLUSION

ASL allows the longitudinal assessment of the degree of AKI induced by cholestatic cirrhosis in rats and can serve as a noninvasive marker for the early and accurate diagnosis of AKI.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

The roles of the glucagon-like peptide-2 and the serum TGF-β1 levels in the intestinal barrier and immune functions in rats with obstructive jaundice

OBJECTIVE

To determine the mechanisms by which glucagon-like peptide-2 (GLP-2) impacts the intestinal barrier function, the immune function, and the serum transforming growth factor-β1 (TGF-β1) levels in rats with obstructive jaundice.

METHODS

Overall, 72 SPF-grade healthy Wistar rats were randomly divided into 4 groups containing 18 rats each: the observation group (ligation of common bile duct, intraperitoneal GLP-2 injection), the control group (ligation of common bile duct, normal saline), the sham-operated group (common bile duct exposed without ligation, normal saline), and the blank group. The serum immune function and the TGF-β1 levels were measured on days 3, 7, and 14 after the intervention.

RESULTS

The body mass was determined to be significantly less in the control group than in the other three groups on day 14 after the intervention (P < 0.05). The TGF-β1, endotoxin, alanine aminotransferase (ALT), and bilirubin were expressed at significantly higher levels in the control group compared with the blank and sham-operated groups and were the highest at each time point, but the levels in the observation group were significantly decreased after the intervention (P < 0.05).

CONCLUSIONS

We found that GLP-2 can decrease the serum TGF-β1 levels, regulate the immune function, reduce the endotoxin and bilirubin, and protect the intestinal barrier function in rats with obstructive jaundice.

Overexpression of angiotensin-converting enzyme 2 by renin-angiotensin system inhibitors. Truth or myth? A systematic review of animal studies

Angiotensin-converting enzyme 2 (ACE2) protects against organ damage in hypertension and cardiovascular diseases by counter regulating the renin-angiotensin system (RAS). ACE2 is also the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Based on the claim that RAS inhibitors (RASIs) cause ACE2 overexpression in some animal experiments, concerns have arisen that RASIs may aggravate SARS-CoV-2 infection and coronavirus disease-2019 severity in RASI-treated patients. To achieve a comprehensive review, a systematic search of MEDLINE/PubMed was conducted regarding the effects of RASIs on tissue ACE2 mRNA/protein expression in healthy animals and animal models of human diseases. We identified 88 eligible articles involving 168 experiments in the heart, kidneys, lungs, and other organs. Three of 38 experiments involving healthy animals showed ACE2 expression greater than twice that of the control (overexpression). Among 102 disease models (130 experiments), baseline ACE2 was overexpressed in 16 models (18 experiments) and less than half the control level (repression) in 28 models (40 experiments). In 72 experiments, RASIs did not change ACE2 levels from the baseline levels of disease models. RASIs caused ACE2 overexpression compared to control levels in seven experiments, some of which were unsupported by other experiments under similar conditions. In 36 experiments, RASIs reversed or prevented disease-induced ACE2 repression, yielding no or marginal changes. Therefore, ACE2 overexpression appears to be a rare rather than common consequence of RASI treatment in healthy animals and disease models. Future studies should clarify the pathophysiological significance of RASI-induced reversal or prevention of ACE2 repression in disease models.

Organoprotective Effects of Spironolactone on Top of Ramipril Therapy in a Mouse Model for Alport Syndrome

Angiotensin-converting enzyme inhibitors (ACEi) delay progression of the inherited renal disease Alport syndrome. However, the effect of ACEis weakens gradually due to an “aldosterone escape”. Here, we investigate if an aldosterone antagonist can counteract loss of ACEi-efficacy. COL4A3−/− mice were treated with ramipril (ACEi), starting at 4.5 weeks of age, and spironolactone was added at 7 weeks of age. Lifespan until renal failure, as well as kidney function parameters, were investigated. Dual therapy decreased proteinuria levels compared to ACEi monotherapy. Matrix accumulation, as well as tubulointerstitial and glomerular scar-tissue formation, were significantly reduced compared to untreated mice and ACEi-monotherapy at 75 and 100 days. Lifespan in dual treated mice was extended compared to untreated mice. However, lifespan was not superior to ACEi monotherapy–despite improved urea-nitrogen levels in the dual therapy group. In conclusion, adding the aldosterone-antagonist spironolactone to ACEi therapy further improved kidney function and reduced proteinuria and fibrosis. However, survival was not improved further, possibly due to premature death from side effects of dual therapy such as hyperkalemia. Thus, dual therapy could offer an effective therapy option for Alport syndrome patients with progressive proteinuria. However, the risks of adverse events require close monitoring.

A comprehensive guide to the pharmacologic regulation of angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor

The recent emergence of coronavirus disease-2019 (COVID-19) as a global pandemic has prompted scientists to address an urgent need for defining mechanisms of disease pathology and treatment. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19, employs angiotensin converting enzyme 2 (ACE2) as its primary target for cell surface attachment and likely entry into the host cell. Thus, understanding factors that may regulate the expression and function of ACE2 in the healthy and diseased body is critical for clinical intervention. Over 66% of all adults in the United States are currently using a prescription drug and while earlier findings have focused on possible upregulation of ACE2 expression through the use of renin angiotensin system (RAS) inhibitors, mounting evidence suggests that various other widely administered drugs used in the treatment of hypertension, heart failure, diabetes mellitus, hyperlipidemias, coagulation disorders, and pulmonary disease may also present a varied risk for COVID-19. Specifically, we summarize mechanisms on how heparin, statins, steroids and phytochemicals, besides their established therapeutic effects, may also interfere with SARS-CoV-2 viral entry into cells. We also describe evidence on the effect of several vitamins, phytochemicals, and naturally occurring compounds on ACE2 expression and activity in various tissues and disease models. This comprehensive review aims to provide a timely compendium on the potential impact of commonly prescribed drugs and pharmacologically active compounds on COVID-19 pathology and risk through regulation of ACE2 and RAS signaling.

Aldosterone and Mineralocorticoid Receptor Signaling as Determinants of Cardiovascular and Renal Injury: From Hans Selye to the Present

BACKGROUND

A full understanding of the mechanisms of action of aldosterone and its interaction with the mineralocorticoid receptor (MR) allows a theoretical framework to predict the therapeutic potential of MR antagonists (MRAs) in CKD, and heart failure with reduced ejection fraction.

SUMMARY

The initial focus on the mechanisms of action of aldosterone was directed primarily on its role in modulating renal excretory function. In contrast, many recent studies have demonstrated a wider and expanded role for aldosterone in modulating inflammation, collagen formation, fibrosis, and necrosis. Increasing evidence has accrued that implicates the pathophysiological overactivation of the MR as a major determinant of progression of CKD. By promoting inflammation and fibrosis, MR overactivation constitutes a pivotal determinant of CKD progression and its associated morbidity and mortality. In accord with this mechanism of action, blockade of the MR is currently being investigated as a novel treatment regimen to slow the progression of CKD. The recently reported FIDELIO-DKD (FInerenone in reducing kiDnEy faiLure and dIsease prOgression in Diabetic Kidney Disease) study demonstrated that patients with CKD and type 2 diabetes who were treated with finerenone (a novel nonsteroidal MRA) manifested a lower risk of a composite primary outcome event compared with patients in the placebo arm (defined as kidney failure, or a sustained decrease of ≥40% in the estimated glomerular filtration rate from baseline, or death from renal causes). In addition, patients in the finerenone group also manifested a lower risk of a key secondary outcome event (defined as death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure). Key Messages: Based on the success of the FIDELIO-DKD study, future studies should be implemented testing the hypothesis that a wide array of nondiabetic CKD is modulated by overactivation of the MR, and consequently may be amenable to treatment with novel nonsteroidal MRAs. Future studies are encouraged to elucidate the clinical implications of the interplay of nonsteroidal MRAs and the components of the renin-angiotensin cascade. The unique and recently reported interrelationship of fibroblast growth factor (FGF23) and aldosterone may also constitute a propitious subject for future investigation.

Inhibition of the norepinephrine transporter rescues vascular hyporeactivity to catecholamine in obstructive jaundice

In patients with obstructive jaundice, the cardiovascular system exhibits hypotension and vascular hyporeactivity. Most norepinephrine is taken up through the neuronal norepinephrine transporter (NET), which is implicated in cardiovascular diseases. A previous study demonstrated that pharmacological NET inhibition could increase resting blood pressure. However, the role of NETs in vascular hyporeactivity induced by obstructive jaundice is poorly understood. This study used the NET inhibitor nisoxetine and a rat model of bile duct ligation (BDL) to investigate whether NET is associated with BDL-induced vascular hyporeactivity. Rats were injected with nisoxetine via the tail vein for 7 consecutive days after BDL. Samples of the superior cervical sympathetic ganglion (SCG) and thoracic aortic rings were processed for investigations. Our results showed that NET expression in the SCG was significantly increased after BDL. Nisoxetine prevented the augmentation of NET expression, increased α₁-adrenoceptor activation, and enhanced the weakened contractile responses of thoracic aortic rings after BDL. Our study demonstrates that nisoxetine plays a protective role in BDL-induced vascular hyporeactivity through increased α₁-adrenoceptor activation in rats.

Oil-In-Water Microemulsion Encapsulation of Antagonist Drugs Prevents Renal Ischemia-Reperfusion Injury in Rats

Developing new therapeutic drugs to prevent ischemia/reperfusion (I/R)-induced renal injuries is highly pursued. Liposomal encapsulation of spironolactone (SP) as a mineralocorticoid antagonist increases dissolution rate, bioavailability and prevents the drug from degradation. In this context, this work develops a new formulation of oil-in-water type microemulsions to enhance the bioavailability of SP. The size of the SP-loaded microemulsion was about 6.0 nm by dynamic light scattering analysis. Briefly, we investigated the effects of nano-encapsulated SP (NESP) on renal oxidative stress, biochemical markers and histopathological changes in a rat model of renal I/R injury. Forty eight male Wistar rats were divided into six groups. Two groups served as control and injury model (I/R). Two groups received “conventional” SP administration (20 mg/kg) and NESP (20 mg/kg), respectively, for two days. The remaining two groups received SP (20 mg/kg) and NESP (20 mg/kg) two days before induction of I/R. At the end of the experiments, serum and kidneys of rats underwent biochemical, molecular and histological examinations. Our results showed that I/R induces renal oxidative stress, abnormal histological features and altered levels of renal biomarkers. Administration of SP in healthy animals did not cause any significant changes in the measured biochemical and histological parameters compared to the control group. However, SP administration in the I/R group caused some corrections in renal injury, although it could not completely restore I/R-induced renal oxidative stress and kidney damage. On the contrary, NESP administration restored kidney oxidative injury via decreasing renal lipid peroxidation and enhancing glutathione, superoxide dismutase and catalase in kidneys of the I/R group. The deviated serum levels of urea, creatinine, total proteins and uric acid were also normalized by NESP administration. Furthermore, NESP protected against renal abnormal histology features induced by I/R. Therefore, NESP has beneficial effects in preventing kidney damage and renal oxidative stress in a rat model of I/R, which deserves further evaluations in the future.

The pathogenesis of renal injury in obstructive jaundice: A review of underlying mechanisms, inducible agents and therapeutic strategies

Kidney injury is one of the main complications of obstructive jaundice (OJ) and its pathogenesis has not been clarified. As an independent risk factor for OJ associated with significant morbidity and mortality, it can be mainly divided into two types of morphological injury and functional injury. We called these dysfunctions caused by OJ-induced kidney injury as OJKI. However, the etiology of OJKI is still not fully clear, and research studies on how OJKI becomes a facilitated factor of OJ are limited. This article reviews the underlying pathological mechanism from five aspects, including metabolisms of bile acids, hemodynamic disturbances, oxidative stress, inflammation and the organic transporter system. Some nephrotoxic drugs and measures that can enhance or reduce the renal function with potential intervention in perioperative periods to alleviate the incidence of OJKI were also described. Furthermore, a more in-depth study on the pathogenesis of OJKI from multiple aspects for exploring more targeted treatment measures were further put forward, which may provide new methods for the prevention and treatment of clinical OJKI and improve the prognosis.

Coronavirus-19: Possible Therapeutic Implications of Spironolactone and Dry Extract of Glycyrrhiza glabra L. (Licorice)

https://clinicaltrials.gov/ (NCT044241349, NCT043465887, NCT04487964)

Spironolactone may provide protection from SARS-CoV-2: Targeting androgens, angiotensin converting enzyme 2 (ACE2), and renin-angiotensin-aldosterone system (RAAS)

In coronavirus disease-19 (COVID-19), four major factors have been correlated with worse prognosis: aging, hypertension, obesity, and exposure to androgen hormones. Angiotensin-converting enzyme-2 (ACE2) receptor, regulation of the renin-angiotensin-aldosterone system (RAAS), and transmembrane serine protease 2 (TMPRSS2) action are critical for the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) cell entry and infectivity. ACE2 expression and RAAS are abnormal in hypertension and obesity, while TMPRSS2 is overexpressed when exposed to androgens, which may justify why these factors are overrepresented in COVID-19. Among therapeutic targets for SARS-CoV-2, we hypothesized that spironolactone, a long used and safe mineralocorticoid and androgen receptors antagonist, with effective anti-hypertensive, cardioprotective, nephroprotective, and anti-androgenic properties may offer pleiotropic actions in different sites to protect from COVID-19. Current data shows that spironolactone may concurrently mitigate abnormal ACE2 expression, correct the balances membrane-attached and free circulating ACE2 and between angiotensin II and Angiotensin-(1-7) (Ang-(1-7)), suppress androgen-mediated TMPRSS2 activity, and inhibit obesity-related RAAS dysfunctions, with consequent decrease of viral priming. Hence, spironolactone may provide protection from SARS-CoV-2, and has sufficient plausibility to be clinically tested, particularly in the early stages of COVID-19.

Repurposing existing drugs for COVID-19: an endocrinology perspective

BACKGROUND

Coronavirus Disease 2019 (COVID-19) is a multi-systemic infection caused by the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), that has become a pandemic. Although its prevailing symptoms include anosmia, ageusia, dry couch, fever, shortness of brief, arthralgia, myalgia, and fatigue, regional and methodological assessments vary, leading to heterogeneous clinical descriptions of COVID-19. Aging, uncontrolled diabetes, hypertension, obesity, and exposure to androgens have been correlated with worse prognosis in COVID-19. Abnormalities in the renin-angiotensin-aldosterone system (RAAS), angiotensin-converting enzyme-2 (ACE2) and the androgen-driven transmembrane serine protease 2 (TMPRSS2) have been elicited as key modulators of SARS-CoV-2.

MAIN TEXT

While safe and effective therapies for COVID-19 lack, the current moment of pandemic urges for therapeutic options. Existing drugs should be preferred over novel ones for clinical testing due to four inherent characteristics: 1. Well-established long-term safety profile, known risks and contraindications; 2. More accurate predictions of clinical effects; 3. Familiarity of clinical management; and 4. Affordable costs for public health systems. In the context of the key modulators of SARS-CoV-2 infectivity, endocrine targets have become central as candidates for COVID-19. The only endocrine or endocrine-related drug class with already existing emerging evidence for COVID-19 is the glucocorticoids, particularly for the use of dexamethasone for severely affected patients. Other drugs that are more likely to present clinical effects despite the lack of specific evidence for COVID-19 include anti-androgens (spironolactone, eplerenone, finasteride and dutasteride), statins, N-acetyl cysteine (NAC), ACE inhibitors (ACEi), angiotensin receptor blockers (ARB), and direct TMPRSS-2 inhibitors (nafamostat and camostat). Several other candidates show less consistent plausibility. In common, except for dexamethasone, all candidates have no evidence for COVID-19, and clinical trials are needed.

CONCLUSION

While dexamethasone may reduce mortality in severely ill patients with COVID-19, in the absence of evidence of any specific drug for mild-to-moderate COVID-19, researchers should consider testing existing drugs due to their favorable safety, familiarity, and cost profile. However, except for dexamethasone in severe COVID-19, drug treatments for COVID-19 patients must be restricted to clinical research studies until efficacy has been extensively proven, with favorable outcomes in terms of reduction in hospitalization, mechanical ventilation, and death.

Currently prescribed drugs in the UK that could upregulate or downregulate ACE2 in COVID-19 disease: a systematic review

OBJECTIVE

To review evidence on routinely prescribed drugs in the UK that could upregulate or downregulate ACE2 and potentially affect COVID-19 disease.

DESIGN

Systematic review.

DATA SOURCE

MEDLINE, EMBASE, CINAHL, the Cochrane Library and Web of Science.

STUDY SELECTION

Any design with animal or human models examining a currently prescribed UK drug compared with a control, placebo or sham group, and reporting an effect on ACE2 level, activity or gene expression.

DATA EXTRACTION AND SYNTHESIS

MEDLINE, EMBASE, CINAHL, the Cochrane Library, Web of Science and OpenGrey from inception to 1 April 2020. Methodological quality was assessed using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk-of-bias tool for animal studies and Cochrane risk-of-bias tool for human studies.

RESULTS

We screened 3360 titles and included 112 studies with 21 different drug classes identified as influencing ACE2 activity. Ten studies were in humans and one hundred and two were in animal models None examined ACE2 in human lungs. The most frequently examined drugs were angiotensin receptor blockers (ARBs) (n=55) and ACE inhibitors (ACE-I) (n=22). More studies reported upregulation than downregulation with ACE-I (n=22), ARBs (n=55), insulin (n=8), thiazolidinedione (n=7) aldosterone agonists (n=3), statins (n=5), oestrogens (n=5) calcium channel blockers (n=3) glucagon-like peptide 1 (GLP-1) agonists (n=2) and Non-steroidal anti-inflammatory drugs (NSAIDs) (n=2).

CONCLUSIONS

There is an abundance of the academic literature and media reports on the potential of drugs that could attenuate or exacerbate COVID-19 disease. This is leading to trials of repurposed drugs and uncertainty among patients and clinicians concerning continuation or cessation of prescribed medications. Our review indicates that the impact of currently prescribed drugs on ACE2 has been poorly studied in vivo, particularly in human lungs where the SARS-CoV-2 virus appears to enact its pathogenic effects. We found no convincing evidence to justify starting or stopping currently prescribed drugs to influence outcomes of COVID-19 disease.

Hypertension and related diseases in the era of COVID-19: a report from the Japanese Society of Hypertension Task Force on COVID-19

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected more than seven million people worldwide, contributing to 0.4 million deaths as of June 2020. The fact that the virus uses angiotensin-converting enzyme (ACE)-2 as the cell entry receptor and that hypertension as well as cardiovascular disorders frequently coexist with COVID-19 have generated considerable discussion on the management of patients with hypertension. In addition, the COVID-19 pandemic necessitates the development of and adaptation to a “New Normal” lifestyle, which will have a profound impact not only on communicable diseases but also on noncommunicable diseases, including hypertension. Summarizing what is known and what requires further investigation in this field may help to address the challenges we face. In the present review, we critically evaluate the existing evidence for the epidemiological association between COVID-19 and hypertension. We also summarize the current knowledge regarding the pathophysiology of SARS-CoV-2 infection with an emphasis on ACE2, the cardiovascular system, and the kidney. Finally, we review evidence on the use of antihypertensive medication, namely, ACE inhibitors and angiotensin receptor blockers, in patients with COVID-19.

ACE2 Attenuates Epithelial-Mesenchymal Transition in MLE-12 Cells Induced by Silica

Purpose

The role of angiotensin-converting enzyme 2 (ACE2) in silicosis remains unknown, although previous studies have suggested that ACE2 may be beneficial. We, therefore, investigated the effect of ACE2 on silicosis, particularly with regard to its role in regulating the epithelial-mesenchymal transition (EMT) induced by silica, with the aim to uncover a new potential target for the treatment of pulmonary fibrosis.

Materials and Methods

We employed wild-type mice treated with diminazene aceturate (DIZE, an ACE2 activator, 15 mg/kg/day for 4 weeks), hACE2-transgenic mice (overexpress the ACE2 gene), and the mouse lung type II epithelial cell line treated with DIZE (10^-7 M for 48 h) or angiotensin-(1-7) [Ang-(1-7)] (10^-4 M for 48 h), following induced fibrotic responses to determine the protective potential of ACE2. Silicosis models were established by orotracheal instillation of SiO₂ (2.5 mg/mouse). Immunostaining was used to determine α-smooth muscle actin (α-SMA) expression. The activities of angiotensin-converting enzyme (ACE) and ACE2 and the levels of angiotensin II (Ang II) and Ang-(1-7) were detected by enzyme-linked immunosorbent assay. The mRNA expression of ACE and ACE2, and protein expression of the renin-angiotensin system (RAS) components and EMT indicators were studied by qRT-PCR and Western blot, respectively.

Results

DIZE treatment and overexpression of ACE2 markedly inhibited the formation of silica-induced lung fibrosis and increased the level of E-cadherin, with concomitant downregulation of pro-collagen, vimentin, and α-SMA via RAS signaling. Furthermore, DIZE and Ang-(1-7) attenuated the EMT and collagen deposition induced by silica in MLE-12 cells. Moreover, these effects were abrogated by MLN-4760 (a specific ACE2 inhibitor) and A779 (a specific Mas receptor blocker).

Conclusion

The overexpression of ACE2 and treatment with DIZE can ameliorate EMT in silicotic mice via activation of the ACE2-Ang-(1-7)-Mas receptor axis, and these changes are accompanied by suppression of the ACE-Ang II-AT1 receptor axis.