Original Research: ACE2 activator associated with physical exercise potentiates the reduction of pulmonary fibrosis

Panax notoginseng saponin alleviates pulmonary fibrosis in rats by modulating the renin-angiotensin system

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is a chronic, progressive, and often fatal interstitial lung disease. Traditional Chinese medicine formulations and their active ingredients have shown potential in the treatment of PF. Panax notoginseng saponin (PNS) is extracted from the widely used traditional Chinese medicinal herb Panax notoginseng (Burkill) F. H. Chen, exhibiting therapeutic effects in pulmonary diseases treatment.

AIM OF THE STUDY

This study aimed to investigate the effects and elucidate possible potential mechanisms of PNS on bleomycin (BLM)-induced PF in rats.

MATERIALS AND METHODS

PF was induced in rats by intratracheal administration of bleomycin (BLM, 5 mg/kg). After disease model induction, the rats were treated with PNS (50, 100, or 200 mg/kg per day) or pirfenidone (PFD, 50 mg/kg per day) for 28 days. Lung function, histopathological changes, collagen deposition, and E- and N-cadherin levels in lung tissue were evaluated. The mechanism of action of PNS was investigated using tandem mass tag-based quantitative proteomics analysis. Immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and Western blot analysis were performed to verify the proteomic results.

RESULTS

PNS treatment improved lung function, ameliorated the BLM-induced increase in the lung coefficient, attenuated the degree of alveolar inflammation and fibrosis, and reduced the elevated collagen level in PF rats. PNS treatment also down-regulated the expression of N-cadherin while up-regulating the expression of E-cadherin. Proteomic and bioinformatic analyses revealed that the renin-angiotensin system (RAS) was closely related to the therapeutic effect of PNS. Immunohistochemistry, Western blot, and ELISA results indicated that PNS exerted its anti-fibrotic effect via regulation of the balance between the angiotensin-converting enzyme (ACE)-angiotensin (Ang)II-AngII receptor type 1 (AT1R) and ACE2-Ang(1-7)-MasR axes.

CONCLUSIONS

PNS ameliorates BLM-induced PF in rats by modulating the RAS homeostasis, and is a new potential therapeutic agent for PF.

Role of Enhancing Aerobic Capacity in Countering COVID-19-induced Liver Injury in Elderlies

COVID-19 is still a world disaster; however, its vaccination is globally available. Liver and gastrointestinal disturbances occur in patients infected with COVID-19 at varying incidences. Aging decreases the functions of the liver. Thus, the elderly have a weaker response to the COVID-19 virus. The COVID-19 virus affects the liver directly through direct and indirect mechanisms. It directly affects the renin-angiotensin system or indirectly causes sepsis, uncontrolled immune reactions, drug-related hepatic injury, and cytokine storm. Also, COVID-19 vaccines and anti-drugs have adverse effects on the liver too. Thus, this review explores the effect of enhancing aerobic capacity as a nonpharmacological intervention on decreasing COVID- 19-induced liver injury. Enhancing aerobic capacity decreases COVID-19-induced liver injury through the following: 1) downregulating systemic and tissue ACE/ANG II/AT1R axis, upregulating ACE2/ANG 1-7/Mas axis, and moving the renin-angiotensin system to the direction of the ACE2/ANG (1-7)/Mas axis, 2) Improving mitochondrial function and oxygenation to body and lung tissues, causing a decrease in harmful oxidative reactions, 3) Increasing the processing of accumulated free radicals and inhibiting the acute respiratory distress syndrome, 4) Acting as an antioxidant to protect the liver from oxidative stress, 5) Increasing the effect of antiviral drugs and COVID-19 vaccines, which improves the function of immune biomarkers, decreases the viral load, and increases the body's defense against the virus, 6) Decreasing coagulation abnormalities and thrombosis. In conclusion, enhancing aerobic capacity may be an efficient nonpharmacological intervention to decrease COVID-19-induced liver injury in elderlies and regenerate the liver to its normal status after being infected by the COVID-19 virus. It also helps to strengthen the body's immunity for better effects of both COVID-19 vaccination and drugs.

Respiratory issues in patients with multiple sclerosis as a risk factor during SARS-CoV-2 infection: a potential role for exercise

Coronavirus disease-2019 (COVID-19) is associated with cytokine storm and is characterized by acute respiratory distress syndrome (ARDS) and pneumonia problems. The respiratory system is a place of inappropriate activation of the immune system in people with multiple sclerosis (MS), and this may cause damage to the lung and worsen both MS and infections.The concerns for patients with multiple sclerosis are because of an enhance risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The MS patients pose challenges in this pandemic situation, because of the regulatory defect of autoreactivity of the immune system and neurological and respiratory tract symptoms. In this review, we first indicate respiratory issues associated with both diseases. Then, the main mechanisms inducing lung damages and also impairing the respiratory muscles in individuals with both diseases is discussed. At the end, the leading role of physical exercise on mitigating respiratory issues inducing mechanisms is meticulously evaluated.

COVID-19 and Diarylamidines: The Parasitic Connection

As emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants (Omicron) continue to outpace and negate combinatorial vaccines and monoclonal antibody therapies targeting the spike protein (S) receptor binding domain (RBD), the appetite for developing similar COVID-19 treatments has significantly diminished, with the attention of the scientific community switching to long COVID treatments. However, treatments that reduce the risk of "post-COVID-19 syndrome" and associated sequelae remain in their infancy, particularly as no established criteria for diagnosis currently exist. Thus, alternative therapies that reduce infection and prevent the broad range of symptoms associated with 'post-COVID-19 syndrome' require investigation. This review begins with an overview of the parasitic-diarylamidine connection, followed by the renin-angiotensin system (RAS) and associated angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSSR2) involved in SARS-CoV-2 infection. Subsequently, the ability of diarylamidines to inhibit S-protein binding and various membrane serine proteases associated with SARS-CoV-2 and parasitic infections are discussed. Finally, the roles of diarylamidines (primarily DIZE) in vaccine efficacy, epigenetics, and the potential amelioration of long COVID sequelae are highlighted.

Stress induced proinflammatory adaptations: Plausible mechanisms for the link between stress and cardiovascular disease

Initiating from Hans Selye’s conceptualization of stress physiology, to our present understanding of allostatic load as the cumulative burden of chronic psychological stress and life events, investigators have sought to identify the physiological mechanisms that link stress to health and disease. Of particular interest has been the link between psychological stress and cardiovascular disease (CVD), the number one cause of death in the United States. In this regard, attention has been directed toward alterations in the immune system in response to stress that lead to increased levels of systemic inflammation as a potential pathway by which stress contributes to the development of CVD. More specifically, psychological stress is an independent risk factor for CVD, and as such, mechanisms that explain the connection of stress hormones to systemic inflammation have been examined to gain a greater understanding of the etiology of CVD. Research on proinflammatory cellular mechanisms that are activated in response to psychological stress demonstrates that the ensuing low-grade inflammation mediates pathways that contribute to the development of CVD. Interestingly, physical activity, along with its direct benefits to cardiovascular health, has been shown to buffer against the harmful consequences of psychological stress by “toughening” the SAM system, HPA axis, and immune system as “cross-stressor adaptations” that maintain allostasis and prevent allostatic load. Thus, physical activity training reduces psychological stress induced proinflammation and attenuates the activation of mechanisms associated with the development of cardiovascular disease. Finally, COVID-19 associated psychological stress and its associated health risks has provided another model for examining the stress-health relationship.

COVID-19 and preventive strategy

In December 2019, an unprecedented outbreak of the novel coronavirus disease 2019 (COVID-19), an infectious disease caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) began to spread internationally, now impacting more than 293,750,692 patients with 5,454,131 deaths globally as of January 5, 2022. COVID-19 is highly pathogenic and contagious which has caused a large-scale epidemic impacting more deaths than the severe acute respiratory syndrome (SARS) epidemic in 2002-2003 or the Middle East respiratory syndrome (MERS) epidemic in 2012-2013. Although COVID-19 symptoms are mild in most people, in those with pre-existing comorbidities there is an increased risk of progression to severe disease and death. In an attempt to mitigate this pandemic, urgent public health measures including quarantining exposed individuals and social distancing have been implemented in most states, while some states have even started the process of re-opening after considering both the economic and public health consequences of social distancing measures. While prevention is crucial, both novel agents and medications already in use with other indications are being investigated in clinical trials for patients with COVID-19. The collaboration between healthcare providers, health systems, patients, private sectors, and local and national governments is needed to protect both healthcare providers and patients to ultimately overcome this pandemic. The purpose of this review is to summarize the peer-reviewed and preprint literature on the epidemiology, transmission, clinical presentation, and available therapies as well as to propose a preventive strategy to overcome the present global pandemic.

Mitigation of Multi-Organ Radiation Injury with ACE2 Agonist Diminazene Aceturate

The renin-angiotensin system (RAS) is known to regulate the pathogenesis of radiation-induced injury as inhibitors of the RAS enzyme angiotensin converting enzyme (ACE) have established function as mitigators of multi-organ radiation injury. To further elucidate the role of RAS signaling during both the acute and delayed syndromes of radiation exposure, we have evaluated whether pharmacologic modulation of alternate RAS enzyme angiotensin converting enzyme 2 (ACE2) reduces the pathogenesis of multi-organ radiation-induced injuries. Here, we demonstrate pharmacologic ACE2 activation with the small molecule ACE2 agonist diminazene aceturate (DIZE) improves survival in rat models of both hematologic acute radiation syndrome (H-ARS) and multi-organ delayed effects of acute radiation exposure (DEARE). In the H-ARS model, DIZE treatment increased 30-day survival by 30% compared to vehicle control rats after a LD50/30 total-body irradiation (TBI) dose of 7.75 Gy. In the mitigation of DEARE, ACE2 agonism with DIZE increased median survival by 30 days, reduced breathing rate, and reduced blood urea nitrogen (BUN) levels compared to control rats after partial-body irradiation (PBI) of 13.5 Gy. DIZE treatment was observed to have systemic effects which may explain the multi-organ benefits observed including mobilization of hematopoietic progenitors to the circulation and a reduction in plasma TGF-beta levels. These data suggest the ACE2 enzyme plays a critical role in the RAS-mediated pathogenesis of radiation injury and may be a potential therapeutic target for the development of medical countermeasures for acute radiation exposure.

Association between the chronology of gestation and the morphometrical skin characteristics at childbirth: a development of predictive model

Objective

The structural maturation of the skin is considered a potential marker of pregnancy dating. This study investigated the correlation between the morphometrical skin characteristics with the pregnancy chronology to propose models for predicting gestational age.

Methods

A cross-sectional analysis selected 35 corpses of newborns. The biopsy was performed up to 48 hours after death in the periumbilical abdomen, palm and sole regions. Pregnancy chronology was based on the obstetric ultrasound before 14 weeks. The dimensions of the skin layers, area of glands and connective fibrous tissue were measured with imaging software support. Univariate and multivariate regression models on morphometric values were used to predict gestational age.

Results

Gestational age at birth ranged from 20.3 to 41.2 weeks. Seventy-one skin specimens resulted in the analysis of 1183 digital histological images. The correlation between skin thickness and gestational age was positive and strong in both regions of the body. The highest univariate correlation between gestational age and skin thickness was using the epidermal layer dimensions, in palm (r=0.867, p<0.001). The multivariate modelling with the thickness of the abdominal epidermis, the dermis and the area of the sebaceous glands adjusted had the highest correlation with gestational age (r=0.99, p<0.001).

Conclusion

The thickness of the protective epidermal barrier is, in itself, a potential marker of pregnancy dating. However, sets of values obtained from skin morphometry enhanced the estimation of the gestational age. Such findings may support non-invasive image approaches to estimate pregnancy dating with various clinical applications.

Moderate Intensity Aerobic Exercise Potential Favorable Effect Against COVID-19: The Role of Renin-Angiotensin System and Immunomodulatory Effects

The coronavirus disease (COVID-19) pandemic is caused by a novel coronavirus (CoV) named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the angiotensin converting enzyme 2 (ACE2) is the cellular receptor of SARS-CoV-2, it has a strong interaction with the renin angiotensin system (RAS). Experimental studies have shown that the higher levels of ACE2 or increasing ACE2/ACE1 ratio improve COVID-19 outcomes through lowering inflammation and death. Aerobic moderate intensity physical exercise fights off infections by two mechanisms, the inhibition of ACE/Ang II/AT1-R pathway and the stimulation of ACE2/Ang-(1-7)/MasR axis. Exercise can also activate the anti-inflammatory response so that it can be a potential therapeutic strategy against COVID-19. Here, we summarize and focus the relation among COVID-19, RAS, and immune system and describe the potential effect of aerobic moderate intensity physical exercise against CoV as a useful complementary tool for providing immune protection against SARS-CoV-2 virus infection, which is a novel intervention that requires further investigation.

Eosinophils mediate SIgA production triggered by TLR2 and TLR4 to control Ascaris suum infection in mice

Human ascariasis is the most prevalent but neglected tropical disease in the world, affecting approximately 450 million people. The initial phase of Ascaris infection is marked by larval migration from the host's organs, causing mechanical injuries followed by an intense local inflammatory response, which is characterized mainly by neutrophil and eosinophil infiltration, especially in the lungs. During the pulmonary phase, the lesions induced by larval migration and excessive immune responses contribute to tissue remodeling marked by fibrosis and lung dysfunction. In this study, we investigated the relationship between SIgA levels and eosinophils. We found that TLR2 and TLR4 signaling induces eosinophils and promotes SIgA production during Ascaris suum infection. Therefore, control of parasite burden during the pulmonary phase of ascariasis involves eosinophil influx and subsequent promotion of SIgA levels. In addition, we also demonstrate that eosinophils also participate in the process of tissue remodeling after lung injury caused by larval migration, contributing to pulmonary fibrosis and dysfunction in re-infected mice. In conclusion, we postulate that eosinophils play a central role in mediating host innate and humoral immune responses by controlling parasite burden, tissue inflammation, and remodeling during Ascaris suum infection. Furthermore, we suggest that the use of probiotics can induce eosinophilia and SIgA production and contribute to controlling parasite burden and morbidity of helminthic diseases with pulmonary cycles.

Role of the Renin-Angiotensin-Aldosterone and Kinin-Kallikrein Systems in the Cardiovascular Complications of COVID-19 and Long COVID

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the virus responsible for the COVID-19 pandemic. Patients may present as asymptomatic or demonstrate mild to severe and life-threatening symptoms. Although COVID-19 has a respiratory focus, there are major cardiovascular complications (CVCs) associated with infection. The reported CVCs include myocarditis, heart failure, arrhythmias, thromboembolism and blood pressure abnormalities. These occur, in part, because of dysregulation of the Renin-Angiotensin-Aldosterone System (RAAS) and Kinin-Kallikrein System (KKS). A major route by which SARS-CoV-2 gains cellular entry is via the docking of the viral spike (S) protein to the membrane-bound angiotensin converting enzyme 2 (ACE2). The roles of ACE2 within the cardiovascular and immune systems are vital to ensure homeostasis. The key routes for the development of CVCs and the recently described long COVID have been hypothesised as the direct consequences of the viral S protein/ACE2 axis, downregulation of ACE2 and the resulting damage inflicted by the immune response. Here, we review the impact of COVID-19 on the cardiovascular system, the mechanisms by which dysregulation of the RAAS and KKS can occur following virus infection and the future implications for pharmacological therapies.

Physical activity and exercise as an essential medical strategy for the COVID-19 pandemic and beyond

COVID-19 disease has been a problem in today's society, which has worldwide effects on different areas, especially on the economy; also, from a health perspective, the disease affects the daily life quality. Physical activity is one major positive factor with regard to enhancing life quality, as it can improve the whole psychological, social, and physical health conditions. Current measures such as social distancing are focused on preventing the viral spread. However, the consequences on other areas are yet to be investigated. Elderly, people with chronic diseases, obese, and others benefit largely from exercise from the perspective of improved health, and preventive measures can drastically improve daily living. In this article, we elaborate the effects of exercise on the immune system and the possible strategies that can be implemented toward greater preventive potential.

Maternal protein restriction before and during pregnancy leads to a gestational day-dependent response of folliculogenesis in outbred mice

Knowledge of follicle development during pregnancy under experimental conditions could be a key factor to understanding maternal ovarian activity. Thus, this study evaluated the effects of maternal protein restriction before and during pregnancy on folliculogenesis. Swiss outbred female mice were allocated to either a control (CC; 20% protein) or treated (TT; 8% protein) group. Pregnant females were killed either on Gestational day (GD) 7.5 or GD17.5 and the ovaries were evaluated using histomorphometric and immunohistochemical methods. TT females showed higher feed and energy intakes, but lower bodyweight gain at GD17.5 (P <0.05). They also had lower number of secondary follicles at GD7.5 and a higher proportion of primordial follicles at GD17.5 (P <0.05). In addition, the areas of the secondary follicles and their granulosa layer were smaller in the TT group on GD7.5, whereas the areas of the oocyte and granulosa layer from atretic follicles were larger (P <0.05). Notwithstanding the slight increase in the insulin-like growth factor 1 (IGF1) receptor expression on GD7.5 in the TT group, there was a marked reduction in IGF1 expression detected in secondary follicles on GD17.5 (P <0.05). Collectively, these results demonstrate that protein restriction during pregnancy negatively affects follicle quality by reducing the size and activation capacity, which is more severe in late pregnancy.

Physical exercise effects on the brain during COVID-19 pandemic: links between mental and cardiovascular health

The current pandemic was caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The quarantine period during corona virus disease 19 (COVID-19) outbreak might affect the quality of life leading thousands of individuals to diminish the daily caloric expenditure and mobility, leading to a sedentary behavior and increase the number of health disorders. Exercising is used as a non-pharmacological treatment in many chronic diseases. Here, we review the molecular mechanisms of physical exercise in COVID-19 pandemic on mental health. We also point links between exercise, mental, and cardiovascular health. The infection caused by SARS-CoV-2 affects host cells binding to angiotensin-converting enzyme-2 (ACE2), which is the receptor for SARS-CoV-2. If there is not enough oxygen supply the lungs and other tissues, such as the heart or brain, are affected. SARS-CoV-2 enhances ACE2 leading to inflammation and neuronal death with possible development of mood disorders, such as depression and anxiety. Physical exercise also enhances the ACE2 expression. Conversely, the activation of ACE2/Ang 1-7/Mas axis by physical exercise induces an antiinflammatory and antifibrotic effect. Physical exercise has beneficial effects on mental health enhancing IGF-1, PI3K, BDNF, ERK, and reducing GSK3β levels. In addition, physical exercise enhances the activity of PGC-1α/ FNDC5/Irisin pathway leading to neuronal survival and the maintenance of a good mental health. Thus, SARS-CoV-2 infection leads to elevation of ACE2 levels through pathological mechanisms that lead to neurological and cardiovascular complications, while the physiological response of ACE2 to physical exercise improves cardiovascular and mental health.

Potentially obesogenic diets alter metabolic and neurobehavioural parameters in Wistar rats: a comparison between two dietary models

BACKGROUND

Clinical studies related to the obesity pandemic have intensified in recent years, being the animal studies are also considered of great relevance. However, despite the fact that many diets have been reported in the literature to induce obesity in animal models, there is still a gap regarding evidence of the efficacy of these models, considering not only changes in somatic parameters, but also the triggering of comorbidities associated with obesity. In this scenario, the aim of this study was to compare the effectiveness of western and cafeteria diets as obesity-inducing protocols, focusing on the evaluation of metabolic, somatic, oxidative, histological and behavioural parameters of Wistar rats.

METHODS

The rats were fed a control (CON), western (WTD) or cafeteria (CAF) diet for 16 weeks.

RESULTS

The CAF diet caused anxiogenic-like behaviour. Body mass (BMI), Lee and adiposity indices increased in the CAF group. CAF and WTD diets reduced glucose and insulin tolerance, caused dyslipidemia, increased lipid peroxidation and decrease antioxidant capacity in the liver, kidneys and brain. The WTD and CAF groups shows greater IL-6 protein expression in adipose tissue, developed hepatic steatosis and ischaemic neurons, whereas interstitial nephritis was observed only in the CAF group.

CONCLUSION

The CAF diet was most effective in inducing obesity, as shown both by the somatic parameters and by the greater number of obesity-related metabolic and neurobehavioural disorders in the evaluated rats.

Physical Activity and Natural Products and Minerals in the SARS-CoV-2 Pandemic: An Update

Coronavirus-disease 19 (COVID-19) has rapidly become a global public health issue, and there is a desperate need for strategies of prevention, reduction, and treatment to halt the epidemic. The coronavirus affects the immune system, and individuals with a compromised immune system, such as those with diabetes, hypertension, obesity, are more susceptible to this virus. Lifestyle-related variables such as physical activity and nutritional supplements can decrease inflammatory markers, increase anti-inflammatory and antioxidant status, and improve the immune system. Lifesty-lerelated variables play preventive roles against various infectious diseases including COVID-19. This review highlights the effects of physical activity and nutrients supplements on the immune system and their possible benefits in combating the harms caused by infection with the COVID-19 virus.

Integrative medicine considerations for convalescence from mild-to-moderate COVID-19 disease

The majority of individuals infected with SARS-CoV-2 have mild-to-moderate COVID-19 disease. Convalescence from mild-to-moderate (MtoM) COVID-19 disease may be supported by integrative medicine strategies. Integrative Medicine (IM) is defined as healing-oriented medicine that takes account of the whole person, including all aspects of lifestyle. Integrative medicine strategies that may support recovery from MtoM COVID-19 are proposed given their clinically studied effects in related conditions. Adoption of an anti-inflammatory diet, supplementation with vitamin D, glutathione, melatonin, Cordyceps, Astragalus and garlic have potential utility. Osteopathic manipulation, Qigong, breathing exercises and aerobic exercise may support pulmonary recovery. Stress reduction, environmental optimization, creative expression and aromatherapy can provide healing support and minimize enduring trauma. These modalities would benefit from clinical trials in people recovering from COVID-19 infection.

COVID-19 in Elderly Adults: Clinical Features, Molecular Mechanisms, and Proposed Strategies

Coronavirus disease 2019 (COVID-19) is causing problems worldwide. Most people are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but elderly populations are more susceptible. Elevated susceptibility and death rates in elderly COVID-19 patients, especially those with age-related complications, are challenges for pandemic prevention and control. In this paper, we review the clinical features of elderly patients with COVID-19 and explore the related molecular mechanisms that are essential for the exploration of preventive and therapeutic strategies in the current pandemic. Furthermore, we analyze the feasibility of currently recommended potential novel methods against COVID-19 among elderly populations.

Molecular mechanisms involved in the positive effects of physical activity on coping with COVID-19

PURPOSE

Physical activity (PA) represents the first line of defence against diseases characterised by increased inflammation status, such as metabolic and infectious diseases. Conversely, a sedentary lifestyle-associated with obesity, type 2 diabetes and cardiovascular disorders-negatively impacts on general health status, including susceptibility to infections. At a time of a pandemic SARS-CoV2 infection, and in the context of the multiorgan crosstalk (widely accepted as a mechanism participating in the pathophysiology of all organs and systems), we examine the complex interplay mediated by skeletal muscle contraction involving the immune system and how this contributes to control health status and to counteract viral infections. In so doing, we review the molecular mechanisms and expression of molecules modulated by PA, able to provide the proper molecular equipment against viral infections such as the current SARS-CoV2.

METHODS

A critical review of the literature was performed to elucidate the molecular mechanisms and mediators induced by PA that potentially impact on viral infections such as SARS-CoV2.

RESULTS

We showed the effects mediated by regular moderate PA on viral adverse effects through the regulation of biological processes involving the crosstalk between skeletal muscle, the immune system and adipose tissue. Evidence was provided of the effects mediated by modulation of the expression of inflammation markers.

CONCLUSION

A tigth association between PA and reduction in inflammation status allows effective counteracting of SARS-CoV2 infection. It is therefore essential to persuade people to keep active.

Manipulation of ACE2 expression in COVID-19

SARS-CoV-2 is the virus responsible for the ongoing COVID-19 outbreak. The virus uses ACE2 receptor for viral entry. ACE2 is part of the counter-regulatory renin-angiotensin-aldosterone system and is also expressed in the lower respiratory tract along the alveolar epithelium. There is, however, significant controversy regarding the role of ACE2 expression in COVID-19 pathogenesis. Some have argued that decreasing ACE2 expression would result in decreased susceptibility to the virus by decreasing available binding sites for SARS-CoV-2 and restricting viral entry into the cells. Others have argued that, like the pathogenesis of other viral pneumonias, including those stemming from previous severe acute respiratory syndrome (SARS) viruses, once SARS-CoV-2 binds to ACE2, it downregulates ACE2 expression. Lack of the favourable effects of ACE2 might exaggerate lung injury by a variety of mechanisms. In order to help address this controversy, we conducted a literature search and review of relevant preclinical and clinical publications pertaining to SARS-CoV-2, COVID-19, ACE2, viral pneumonia, SARS, acute respiratory distress syndrome and lung injury. Our review suggests, although controversial, that patients at increased susceptibility to COVID-19 complications may have reduced baseline ACE2, and by modulating ACE2 expression one can possibly improve COVID-19 outcomes. Herein, we elucidate why and how this potential mechanism might work.

Mucuna pruriens Administration Minimizes Neuroinflammation and Shows Anxiolytic, Antidepressant and Slimming Effects in Obese Rats

This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract.

Should ACE2 be given a chance in COVID-19 therapeutics: A semi-systematic review of strategies enhancing ACE2

The severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) has resulted in almost 28 million cases of COVID-19 (Corona virus disease-2019) and more than 900000 deaths worldwide since December 2019. In the absence of effective antiviral therapy and vaccine, treatment of COVID-19 is largely symptomatic. By making use of its spike (S) protein, the virus binds to its primary human cell receptor, angiotensin converting enzyme 2 (ACE2) which is present in the pulmonary epithelial cells as well as other organs. SARS-CoV-2 may cause a downregulation of ACE2. ACE2 plays a protective role in the pulmonary system through its Mas-receptor and alamandine-MrgD-TGR7 pathways. Loss of this protective effect could be a major component of COVID-19 pathogenesis. An attractive strategy in SARS-CoV-2 therapeutics would be to augment ACE2 either directly by supplementation or indirectly through drugs which increase its levels or stimulate its downstream players. In this semi-systematic review, we have analysed the pathophysiological interplay between ACE and ACE2 in the cardiopulmonary system, the modulation of these two proteins by SARS-CoV-2, and potential therapeutic avenues targeting ACE-Ang II and ACE2-Ang (1-7) axes, that can be utilized against COVID-19 disease progression.

Exercise Improves Lung Inflammation, but Not Lung Remodeling and Mechanics in a Model of Bleomycin-Induced Lung Fibrosis

Introduction

Moderate aerobic exercise training accelerates the resolution of lung fibrosis in a model of bleomycin-induced pulmonary fibrosis. However, whether it can inhibit the development of lung fibrosis is unknown.

Materials and Methods

C57Bl/6 mice were distributed into four groups: Control (Co), Exercise (Exe), Bleomycin (Bleo), and Bleomycin+Exercise (Bleo+Exe). A single bleomycin dose (1.5 UI/kg) was administered orotracheally and treadmill exercise started in the same day, enduring for 4 weeks, 5x/week, 60 minutes/session, at moderate intensity. Lung mechanics, systemic and pulmonary inflammation, and lung remodeling were evaluated. Lung homogenates were used to evaluate the antioxidant status.

Results

Total cells, macrophages, lymphocytes, and neutrophils numbers, in agreement with IL-6 levels, were higher in the BAL and serum of Bleo group, compared to other groups. In addition, lung levels of LTB4 in Bleo were higher than other groups, whereas SOD activity and nitric oxide levels in exercised groups (Exe and Exe+Bleo) compared to the Bleo group. Lung GPX activity was lower in Bleo and Exe+Bleo groups compared to others. Exe and Exe+Bleo groups also showed higher IL-10 expression by lung macrophages than other groups, whereas TGF-β expression was higher in Exe, Bleo, and Exe+Bleo groups compared to control. CCR7 expression was induced only in the Exe group. However, exercise did not improve lung remodeling and mechanics, or serum and pulmonary levels of VEGF, IGF-1, and TGF-β.

Conclusion

Aerobic exercise training initiated concomitantly with induction of pulmonary fibrosis reduces lung and systemic inflammation but fails to inhibit lung fibrosis and mechanics impairment.

Physical Exercise and the Renin Angiotensin System: Prospects in the COVID-19

Recent reports have shown that the renin angiotensin system (RAS) plays an important role in the Coronavirus disease 2019 (COVID-19) because the angiotensin converting enzyme 2 is the receptor for the severe acute respiratory syndrome coronavirus 2. In addition, the balance of RAS components can be involved in the pathogenesis and progression of COVID-19, especially in patients with metabolic and cardiovascular diseases. On the other hand, physical exercise is effective to prevent and to counteract the consequences of such diseases and one of the biological mediators of the exercise adaptation is the RAS. This review was designed to highlight the connection between COVID-19 and RAS, and to discuss the role of the RAS as a mediator of the benefits of physical exercise in COVID-19 pandemic.

Molecular mechanisms involved in the positive effects of physical activity on coping with COVID-19

PURPOSE

Physical activity (PA) represents the first line of defence against diseases characterised by increased inflammation status, such as metabolic and infectious diseases. Conversely, a sedentary lifestyle-associated with obesity, type 2 diabetes and cardiovascular disorders-negatively impacts on general health status, including susceptibility to infections. At a time of a pandemic SARS-CoV2 infection, and in the context of the multiorgan crosstalk (widely accepted as a mechanism participating in the pathophysiology of all organs and systems), we examine the complex interplay mediated by skeletal muscle contraction involving the immune system and how this contributes to control health status and to counteract viral infections. In so doing, we review the molecular mechanisms and expression of molecules modulated by PA, able to provide the proper molecular equipment against viral infections such as the current SARS-CoV2.

METHODS

A critical review of the literature was performed to elucidate the molecular mechanisms and mediators induced by PA that potentially impact on viral infections such as SARS-CoV2.

RESULTS

We showed the effects mediated by regular moderate PA on viral adverse effects through the regulation of biological processes involving the crosstalk between skeletal muscle, the immune system and adipose tissue. Evidence was provided of the effects mediated by modulation of the expression of inflammation markers.

CONCLUSION

A tigth association between PA and reduction in inflammation status allows effective counteracting of SARS-CoV2 infection. It is therefore essential to persuade people to keep active.

Does High Cardiorespiratory Fitness Confer Some Protection Against Proinflammatory Responses After Infection by SARS-CoV-2?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in China in late 2019 and has since spread rapidly to every continent in the world. This pandemic continues to cause widespread personal suffering, along with severe pressure on medical and health care providers. The symptoms of SARS-CoV-2 and the subsequent prognosis are worsened in individuals who have preexisting comorbidities prior to infection by the virus. Individuals with obesity or overweight, insulin resistance, and diabetes typically have chronic low-grade inflammation characterized by increased levels of several proinflammatory cytokines and the inflammasome; this state predisposes to greater risk for infection along with more adverse outcomes. Here, we consider whether a high level of cardiorespiratory fitness induced by prior exercise training may confer some innate immune protection against COVID-19 by attenuating the "cytokine storm syndrome" often experienced by "at risk" individuals.

Angiotensin II receptors: Impact for COVID-19 severity

COVID-19 is an outbreak of viral pneumonia which became a global health crisis, and the risk of morbidity and mortality of people with obesity are higher. SARS-CoV-2, the pathogen of COVID-19, enters into cells through binding to the Angiotensin Converting Enzyme (ACE) homolog-2 (ACE2). ACE2 is a regulator of two contrary pathways in renin angiotensin system (RAS): ACE-Ang-II-AT1R axis and ACE2-Ang 1-7-Mas axis. Viral entry process eventuates in downregulation of ACE2 and subsequent activation of ACE-Ang-II-AT1R axis. ACE-Ang II-AT1R axis increases lipid storage, reduces white-to-beige fat conversion and plays role in obesity. Conversely, adipose tissue is an important source of angiotensin, and obesity results in increased systemic RAS. ACE-Ang-II-AT1R axis, which has proinflammatory, profibrotic, prothrombotic, and vasoconstrictive effects, is potential mechanism of more severe SARS-CoV-2 infection. The link between obesity and severe COVID-19 may be attributed to ACE2 consumption and subsequent ACE-Ang-II-AT1R axis activation. Therefore, patients with SARS-CoV-2 infection may benefit from therapeutic strategies that activate ACE2-Ang 1-7-Mas axis, such as Ang II receptor blockers (ARBs), ACE inhibitors (ACEIs), Mas receptor agonists and ACE2.

Impact of diminazene aceturate on renin-angiotensin system, infectious myocarditis and skeletal myositis in mice: An in vitro and in vivo study

Although renin-angiotensin system (RAS) imbalance is manifested in cardiomyopathies with different etiologies, the impact of RAS effectors on Chagas cardiomyopathy and skeletal myositis is poorly understood. Given that diminazene aceturate (DMZ) shares trypanocidal, angiotensin-converting enzyme 2 (ACE2) and angiotensin-(1-7) stimulatory effects, we investigated the impact of DMZ on cardiomyocytes infection in vitro, renin-angiotensin system, Chagas cardiomyopathy and skeletal myositis in vivo. Cardiomyocytes and T. cruzi were used to evaluate DMZ toxicity in vitro. The impact of 20-days DMZ treatment (1 mg/kg) was also investigated in uninfected and T. cruzi-infected mice as follows: control uninfected and untreated, uninfected treated with DMZ, infected untreated and infected treated with DMZ. DMZ had low toxicity on cardiomyocytes, induced dose-dependent antiparasitic activity on T. cruzi trypomastigotes, and reduced parasite load but not infection rates in cardiomyocytes. DMZ increased ACE2 activity and angiotensin-(1-7) plasma levels but exerted no interference on angiotensin-converting enzyme (ACE) activity, ACE, ACE2 and angiotensin II levels in uninfected and infected mice. DMZ treatment also reduced IFN-γ and IL-2 circulating levels but was ineffective in attenuating parasitemia, MCP-1, IL-10, anti-T. cruzi IgG, nitrite/nitrate and malondialdehyde production, myocarditis and skeletal myositis compared to infected untreated animals. As the antiparasitic effect of DMZ in vitro did not manifest in vivo, this drug exhibited limited relevance to the treatment of Chagas disease. Although DMZ is effective in upregulating angiotensin-(1-7) levels, this molecule does not act as a potent modulator of T. cruzi infection, which can establish heart and skeletal muscle parasitism, lipid oxidation and inflammatory damage, even in the presence of high concentrations of this RAS effector.

Impact of sex and gender on COVID-19 outcomes in Europe

BACKGROUND

Emerging evidence from China suggests that coronavirus disease 2019 (COVID-19) is deadlier for infected men than women with a 2.8% fatality rate being reported in Chinese men versus 1.7% in women. Further, sex-disaggregated data for COVID-19 in several European countries show a similar number of cases between the sexes, but more severe outcomes in aged men. Case fatality is highest in men with pre-existing cardiovascular conditions. The mechanisms accounting for the reduced case fatality rate in women are currently unclear but may offer potential to develop novel risk stratification tools and therapeutic options for women and men.

CONTENT

The present review summarizes latest clinical and epidemiological evidence for gender and sex differences in COVID-19 from Europe and China. We discuss potential sex-specific mechanisms modulating the course of disease, such as hormone-regulated expression of genes encoding for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) entry receptors angiotensin converting enzyme (ACE) 2 receptor and TMPRSS2 as well as sex hormone-driven innate and adaptive immune responses and immunoaging. Finally, we elucidate the impact of gender-specific lifestyle, health behavior, psychological stress, and socioeconomic conditions on COVID-19 and discuss sex specific aspects of antiviral therapies.

CONCLUSION

The sex and gender disparities observed in COVID-19 vulnerability emphasize the need to better understand the impact of sex and gender on incidence and case fatality of the disease and to tailor treatment according to sex and gender. The ongoing and planned prophylactic and therapeutic treatment studies must include prospective sex- and gender-sensitive analyses.

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.

Up-regulation of brain cytokines and metalloproteinases 1 and 2 contributes to neurological deficit and brain damage in transient ischemic stroke

Ischemic stroke represents a major cause of adult death and severe neurological disability worldwide. Reperfusion following brain ischemia produces an inflammatory cascade that increases brain damage. In this context, matrix metalloproteinases (MMPs) play an important role as pro-inflammatory mediators. The MMP 2 up-regulation seems to promote matrix degradation, blood-brain barrier (BBB) disruption and facilitates the influx of peripheral inflammatory cells to the brain after stroke. However, there are not studies about MMP-1 in this condition. The aim of this study is to evaluate the association of brain damage, inflammatory response and the immunostaining profile of matrix metalloproteinases 1 and 2 after transient global cerebral ischemia. Mice were submitted to bilateral common carotid arterial occlusion (BCCAo) during 25 min. After three days of reperfusion, the neurological deficit score was evaluated and the animals were euthanized. Brain samples were collected in order to analyze the histopathological damage, MMPs 1 and 2 immunostaining and cytokines and chemokines levels. Ischemic group showed neurological deficits associated with brain lesions, characterized by necrotic core and penumbra zone three days after reperfusion. Higher brain immunostaining of MMP-1 and MMP-2 was observed in BCCAo samples than in sham samples. Ischemic group also exhibited increased brain levels of the cytokines tumoral necrosis factor (TNF) and interleukin 1β (IL-1β), chemokine (C-X-C motif) ligand 1 (CXCL1), and chemokine (C-C motif) ligand 5 (CCL5) in comparison to sham group. Our results suggest that the MMP-1 and MMP-2 raise, associated with the up-regulation of inflammatory mediators, contributes to brain damage and neurological deficits after global brain ischemia followed by three days of reperfusion in mice.

Comorbidity associated to Ascaris suum infection during pulmonary fibrosis exacerbates chronic lung and liver inflammation and dysfunction but not affect the parasite cycle in mice

Ascariasis is considered the most neglected tropical disease, and is a major problem for the public health system. However, idiopathic pulmonary fibrosis (IPF) is a result of chronic extracellular deposition of matrix in the pulmonary parenchyma, and thickening of the alveolar septa, which reduces alveolar gas exchange. Considering the high rates of ascariasis and pulmonary fibrosis, we believe that these two diseases may co-exist and possibly lead to comorbidities. We therefore investigated the mechanisms involved in comorbidity of Ascaris suum (A. suum) infection, which could interfere with the progression of pulmonary fibrosis. In addition, we evaluated whether a previous lung fibrosis could interfere with the pulmonary cycle of A. suum in mice. The most important findings related to comorbidity in which A. suum infection exacerbated pulmonary and liver injury, inflammation and dysfunction, but did not promote excessive fibrosis in mice during the investigated comorbidity period. Interestingly, we found that pulmonary fibrosis did not alter the parasite cycle that transmigrated preferentially through preserved but not fibrotic areas of the lungs. Collectively, our results demonstrate that A. suum infection leads to comorbidity, and contributes to the aggravation of pulmonary dysfunction during pulmonary fibrosis, which also leads to significant liver injury and inflammation, without changing the A. suum cycle in the lungs.

Ascariasis is considered a major problem for the public health system, which has an estimated 800 million infected people worldwide. It occurs in the United States, Africa, Asia, and Latin America, and is generally associated with poverty and precarious health conditions. Pulmonary fibrosis affects 14–63 people per 100,000 habitants/year, and is characterized by collagen deposition and alveolar wall thickening. The comorbidities caused by infections are commonly associated with pulmonary fibrosis exacerbations, poor prognosis, and high mortality. Despite the comorbidities caused by helminth infections, which display a pulmonary parasitic cycle such as that of Ascaris, there is no evidence relating to pulmonary fibrosis progression, possibly because Ascariasis is considered a neglected disease. We evaluated the role of Ascaris during pulmonary fibrosis. We considered two simple questions: (1) Whether Ascaris infection could protect or aggravate fibrosis (comorbidities) and (2) whether pulmonary fibrosis could change the cycle of Ascaris as a result of increased alveolar thickening, larvae retention, and the limitation of influx into airways. We answered both questions as follows: (1) Ascaris infection exacerbates pulmonary and liver injury and inflammation, but not fibrosis; and (2) Pulmonary fibrosis did not alter the course of Ascaris cycle in lungs during transmigration into airways, because Ascaris preferentially seeks and penetrates into the lung areas, which are thought to be preserved, but not into fibrotic areas.

Lung

In the present chapter, we review and summarize current advances on the role of angiotensin-(1-7) [Ang-(1-7)] in the pathophysiology of main lung diseases: pulmonary hypertension (PH), acute respiratory distress syndrome (ARDS), asthma, and pulmonary fibrosis. Understanding the involvement of renin angiotensin system (RAS) in pulmonary inflammation may open new therapeutic possibilities for the treatment of respiratory diseases. Studies to date showed that Ang-(1-7) presents anti-inflammatory, antifibrotic activities and reduces pulmonary remodeling. These actions support the development of new pharmacological therapies based on the increase in Ang-(1-7) in the lungs to improve the treatment of inflammatory diseases.