Antiviral, anti-inflammatory and antioxidant effects of curcumin and curcuminoids in SH-SY5Y cells infected by SARS-CoV-2.

COVID-19, caused by SARS-CoV-2, affects neuronal cells, causing several symptoms such as memory loss, anosmia and brain inflammation. Curcuminoids (Me08 e Me23) and curcumin (CUR) are derived from Curcuma Longa extract (EXT). Many therapeutic actions have been linked to these compounds, including antiviral action. Given the severe implications of COVID-19, especially within the central nervous system, our study aims to shed light on the therapeutic potential of curcuminoids against SARS-CoV-2 infection, particularly in neuronal cells. Here, we investigated the effects of CUR, EXT, Me08 and Me23 in human neuroblastoma SH-SY5Y. We observed that Me23 significantly decreased the expression of plasma membrane-associated transmembrane protease serine 2 (TMPRSS2) and TMPRSS11D, consequently mitigating the elevated ROS levels induced by SARS-CoV-2. Furthermore, Me23 exhibited antioxidative properties by increasing NRF2 gene expression and restoring NQO1 activity following SARS-CoV-2 infection. Both Me08 and Me23 effectively reduced SARS-CoV-2 replication in SH-SY5Y cells overexpressing ACE2 (SH-ACE2). Additionally, all of these compounds demonstrated the ability to decrease proinflammatory cytokines such as IL-6, TNF-α, and IL-17, while Me08 specifically reduced INF-γ levels. Our findings suggest that curcuminoid Me23 could serve as a potential agent for mitigating the impact of COVID-19, particularly within the context of central nervous system involvement.

Progestogen-Mediated Neuroprotection in Central Nervous System Disorders.

Neuroactive steroids can be synthetic or endogenous molecules produced by neuronal and glial cells and peripheral glands. Examples include estrogens, testosterone, progesterone and its reduced metabolites such as 5α-dihydro-progesterone and allopregnanolone. Steroids produced by neurons and glia target the nervous system and are called neurosteroids. Progesterone and analog molecules, known as progestogens, have been shown to exhibit neurotrophic, neuroprotective, antioxidant, anti-inflammatory, glial modulatory, promyelinating, and remyelinating effects in several experimental models of neurodegenerative and injury conditions. Pleiotropic mechanisms of progestogens may act synergistically to prevent neuron degeneration, astrocyte and microglial reactivity, reducing morbidity and mortality. The aim of this review is to summarize the significant findings related to the actions of progesterone and other progestogens in experimental models and epidemiological and clinical trials of some of the most prevalent and debilitating chronic neurodegenerative disorders, namely, Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and multiple sclerosis. We evaluated progestogen alterations under pathological conditions, how pathology modifies their levels, as well as the intracellular mechanisms and glial interactions underlying their neuroprotective effects. Furthermore, an analysis of the potential of natural progestogens and synthetic progestins as neuroprotective and regenerative agents, when administered as hormone replacement therapy in menopause, is also discussed.

Overexpression of estrogen receptor GPER1 and G1 treatment reduces SARS-CoV-2 infection in BEAS-2B bronchial cells.

Gender-bias in COVID-19 severity has been suggested by clinical data. Experimental data in cell and animal models have demonstrated the role of sex hormones, particularly estrogens, in viral infections such as in COVID-19. SARS-CoV-2 uses ACE2 as a receptor to recognize host cells, and the protease TMPRSS2 for priming the Spike protein, facilitating virus entry into cells. However, the involvement of estrogenic receptors in SARS-CoV-2 infection are still being explored. Thus, in order to investigate the role of estrogen and its receptors in COVID-19, the estrogen receptors ERα, ERß and GPER1 were overexpressed in bronchial BEAS-2B cell, and then infected with SARS-CoV-2. Interestingly, the levels of ACE2 and TMPRSS2 mRNA were higher in SARS-CoV-2-infected cells, but no difference was observed in cells with estrogen receptors overexpression. GPER1 can be involved in virus infection or replication, since its higher levels reduces SARS-CoV-2 load. On the other hand, pharmacological antagonism of GPER1 enhanced viral load. Those data suggest that GPER1 has an important role in SARS-CoV-2 infection.

SARS-CoV-2 infection and replication kinetics in different human cell types: The role of autophagy, cellular metabolism and ACE2 expression.

AIMS: This study evaluated SARS-CoV-2 replication in human cell lines derived from various tissues and investigated molecular mechanisms related to viral infection susceptibility and replication. MAIN METHODS: SARS-CoV-2 replication in BEAS-2B and A549 (respiratory tract), HEK-293 T (kidney), HuH7 (liver), SH-SY5Y (brain), MCF7 (breast), Huvec (endothelial) and Caco-2 (intestine) was evaluated by RT-qPCR. Concomitantly, expression levels of ACE2 (Angiotensin Converting Enzyme) and TMPRSS2 were assessed through RT-qPCR and western blot. Proteins related to autophagy and mitochondrial metabolism were monitored in uninfected cells to characterize the cellular metabolism of each cell line. The effect of ACE2 overexpression on viral replication in pulmonary cells was also investigated. KEY FINDINGS: Our data show that HuH7, Caco-2 and MCF7 presented a higher viral load compared to the other cell lines. The increased susceptibility to SARS-CoV-2 infection seems to be associated not only with the differential levels of proteins intrinsically related to energetic metabolism, such as ATP synthase, citrate synthase, COX and NDUFS2 but also with the considerably higher TMPRSS2 mRNA expression. The two least susceptible cell types, BEAS-2B and A549, showed drastically increased SARS-CoV-2 replication capacity when ACE2 was overexpressed. These modified cell lines are relevant for studying SARS-CoV-2 replication in vitro. SIGNIFICANCE: Our data not only reinforce that TMPRSS2 expression and cellular energy metabolism are important molecular mechanisms for SARS-CoV-2 infection and replication, but also indicate that HuH7, MCF7 and Caco-2 are suitable models for mechanistic studies of COVID-19. Moreover, pulmonary cells overexpressing ACE2 can be used to understand mechanisms associated with SARS-CoV-2 replication.

Unraveling Muscle Impairment Associated With COVID-19 and the Role of 3D Culture in Its Investigation.

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been considered a public health emergency, extensively investigated by researchers. Accordingly, the respiratory tract has been the main research focus, with some other studies outlining the effects on the neurological, cardiovascular, and renal systems. However, concerning SARS-CoV-2 outcomes on skeletal muscle, scientific evidence is still not sufficiently strong to trace, treat and prevent possible muscle impairment due to the COVID-19. Simultaneously, there has been a considerable amount of studies reporting skeletal muscle damage in the context of COVID-19. Among the detrimental musculoskeletal conditions associated with the viral infection, the most commonly described are sarcopenia, cachexia, myalgia, myositis, rhabdomyolysis, atrophy, peripheral neuropathy, and Guillain-Barré Syndrome. Of note, the risk of developing sarcopenia during or after COVID-19 is relatively high, which poses special importance to the condition amid the SARS-CoV-2 infection. The yet uncovered mechanisms by which musculoskeletal injury takes place in COVID-19 and the lack of published methods tailored to study the correlation between COVID-19 and skeletal muscle hinder the ability of healthcare professionals to provide SARS-CoV-2 infected patients with an adequate treatment plan. The present review aims to minimize this burden by both thoroughly exploring the interaction between COVID-19 and the musculoskeletal system and examining the cutting-edge 3D cell culture techniques capable of revolutionizing the study of muscle dynamics.

17ß-estradiol reduces SARS-CoV-2 infection in vitro.

The COVID-19 has originated from Wuhan, China, in December 2019 and has been affecting the public health system, society, and economy in an unheard-of manner. There is no specific treatment or vaccine available for COVID-19. Previous data showed that men are more affected than women by COVID-19, then we hypothesized whether sex hormones could be protecting the female organism against the infection. VERO E6 cells have been commonly used as in vitro model for SARS-CoV-2 infection. In our experimental approach, we have treated VERO E6 cells with 17ß-estradiol to evaluate the modulation of SARS-CoV-2 infection in this cell line. Here we demonstrated that estrogen protein receptors ERα, ERß, and GPER1 are expressed by VERO E6 cells and could be used to study the effects of this steroid hormone. Previous and 24-hours post-infection, cells treated with 17ß-estradiol revealed a reduction in the viral load. Afterward, we found that SARS-CoV-2 infection per se results in ACE2 and TMPRSS2 increased gene expression in VERO E6-cell, which could be generating a cycle of virus infection in host cells. The estrogen treatment reduces the levels of the TMPRSS2, which are involved with SARS-CoV-2 infectiveness capacity, and hence, reducing the pathogenicity/genesis. These data suggest that estrogen could be a potential therapeutic target promoting cell protection against SARS-CoV-2. This opens new possibilities for further studies on 17ß-estradiol in human cell lines infected by SARS-CoV-2 and at least in part, explain why men developed a more severe COVID-19 compared to women.

SARS-CoV-2 and the possible connection to ERs, ACE2, and RAGE: Focus on susceptibility factors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has provoked major stresses on the health-care systems of several countries, and caused the death of more than a quarter of a million people globally, mainly in the elderly population with preexisting pathologies. Previous studies with coronavirus (SARS-CoV) point to gender differences in infection and disease progression with increased susceptibility in male patients, indicating that estrogens may be associated with physiological protection against the coronavirus. Therefore, the objectives of this work are threefold. First, we aim to summarize the SARS-CoV-2 infection pathway and the roles both the virus and patient play in COVID-19 (Coronavirus disease 2019) progression, clinical symptomatology, and mortality. Second, we detail the effect estrogen has on viral infection and host infection response, including its role in both the regulation of key viral receptor expression and the mediation of inflammatory activity. Finally, we describe how ERs (estrogen receptors) and RAGE (receptor for advanced glycation end-products) play a critical role in metabolic pathways, which we envisage could maintain a close interplay with SARS-CoV and COVID-19 mortality rates, despite a current lack of research directly determining how. Taken together, we present the current state of the field regarding SARS-CoV-2 research and illuminate where research is needed to better define the role both estrogen and metabolic comorbidities have in the COVID-19 disease state, which can be key in screening potential therapeutic options as the search for effective treatments continue.