Therapeutic Potential of Exploiting Autophagy Cascade Against Coronavirus Infection

Trigonelline Chloride Ameliorated Triphenyltin-Induced Testicular Autophagy, Inflammation, and Apoptosis: Role of Recovery

Triphenyltin chloride (TPT-Cl) is an organometallic organotin. This study aimed to investigate the role of trigonelline (TG) along with the impact of TPT withdrawal on the testicular toxicity induced by TPT-Cl. Thirty-six adult male albino rats were divided into control, TG (40 mg/kg/day), TPT-Cl (0.5 mg/kg/day), TG + TPT-Cl, and recovery groups. Animals were daily gavaged for 12 weeks. Both TG and TPT-Cl withdrawal improved TPT-Cl-induced testicular toxicity features involving testis and relative testis weight reduction, luteinizing hormone, follicular stimulating hormone, and sex hormone-binding globulin elevation, reduction of inhibin B, free testosterone levels, and sperm count reduction with increased abnormal sperm forms. Moreover, both TG and TPT-Cl withdrawal reduced inflammatory activin A, follistatin, tumor necrosis factor α, interleukin-1β, and proapoptotic Bax and elevated antiapoptotic Bcl2 in testicular tissues mediated by TPT-Cl. TG and TPT-Cl withdrawal restored the excessive autophagy triggered by TPT-Cl via elevation of mTOR, AKT, PI3K, and P62/SQSTM1 and reduction of AMPK, ULK1, Beclin1, and LC3 mRNA gene expressions and regained the deteriorated testicular structure. In conclusion, TG and TPT-Cl withdrawal had an ameliorative role in partially reversing TPT-Cl-induced testicular toxicity. However, the findings indicated that the use of TG as an adjunctive factor is more favorable than TPT-Cl withdrawal, suggesting the capability of the testis for partial self-improvement.

Protective role of stem cells in POI: Current status and mechanism of action, a review article

Premature ovarian insufficiency (POI) has far-reaching consequences on women's life quality. Due to the lack of full recognition of the etiology and complexity of this disease, there is no appropriate treatment for infected patients. Recently, stem cell therapy has attracted the attention of regenerative medicine scholars and offered promising outcomes for POI patients. Several kinds of stem cells, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) have been used for the treatment of ovarian diseases. However, their potential protective mechanisms are still unknown. Undoubtedly, a better understanding of the therapeutic molecular and cellular mechanisms of stem cells will address uncover strategies to increase their clinical application for multiple disorders such as POI. This paper describes a detailed account of the potential properties of different types of stem cells and provides a comprehensive review of their protective mechanisms, particularly MSC, in POI disorder. In addition, ongoing challenges and several strategies to improve the efficacy of MSC in clinical use are addressed. Therefore, this review will provide proof-of-concept for further clinical application of stem cells in POI.

AMPK inhibitor, compound C, inhibits coronavirus replication in vitro

The coronavirus disease (COVID-19) pandemic has resulted in more than six million deaths by October 2022. Vaccines and antivirals for severe acute respiratory syndrome coronavirus 2 are now available; however, more effective antiviral drugs are required for effective treatment. Here, we report that a potent AMP-activated protein kinase (AMPK) inhibitor, compound C/dorsomorphin, inhibits the replication of the human coronavirus OC43 strain (HCoV-OC43). We examined HCoV-OC43 replication in control and AMPK-knockout (KO) cells and found that the virus replication decreased in AMPK-KO cells. Next, we examined the effect of the AMPK inhibitor, compound C on coronavirus replication. Compound C treatment efficiently inhibited the replication and decreased the coronavirus-induced cytotoxicity, further inhibiting autophagy. In addition, treatment with compound C in combination with chloroquine synergistically inhibited coronavirus replication. These results suggest that compound C can be considered as a potential drug candidate for COVID-19.

Cognitive Impairment in Multiple Sclerosis

Almost three million individuals suffer from multiple sclerosis (MS) throughout the world, a demyelinating disease in the nervous system with increased prevalence over the last five decades, and is now being recognized as one significant etiology of cognitive loss and dementia. Presently, disease modifying therapies can limit the rate of relapse and potentially reduce brain volume loss in patients with MS, but unfortunately cannot prevent disease progression or the onset of cognitive disability. Innovative strategies are therefore required to address areas of inflammation, immune cell activation, and cell survival that involve novel pathways of programmed cell death, mammalian forkhead transcription factors (FoxOs), the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), and associated pathways with the apolipoprotein E (APOE-ε4) gene and severe acute respiratory syndrome coronavirus (SARS-CoV-2). These pathways are intertwined at multiple levels and can involve metabolic oversight with cellular metabolism dependent upon nicotinamide adenine dinucleotide (NAD+). Insight into the mechanisms of these pathways can provide new avenues of discovery for the therapeutic treatment of dementia and loss in cognition that occurs during MS.

Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System

It is estimated that, at minimum, 500 million individuals suffer from cellular metabolic dysfunction, such as diabetes mellitus (DM), throughout the world. Even more concerning is the knowledge that metabolic disease is intimately tied to neurodegenerative disorders, affecting both the central and peripheral nervous systems as well as leading to dementia, the seventh leading cause of death. New and innovative therapeutic strategies that address cellular metabolism, apoptosis, autophagy, and pyroptosis, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), growth factor signaling with erythropoietin (EPO), and risk factors such as the apolipoprotein E (APOE-ε4) gene and coronavirus disease 2019 (COVID-19) can offer valuable insights for the clinical care and treatment of neurodegenerative disorders impacted by cellular metabolic disease. Critical insight into and modulation of these complex pathways are required since mTOR signaling pathways, such as AMPK activation, can improve memory retention in Alzheimer's disease (AD) and DM, promote healthy aging, facilitate clearance of β-amyloid (Aß) and tau in the brain, and control inflammation, but also may lead to cognitive loss and long-COVID syndrome through mechanisms that can include oxidative stress, mitochondrial dysfunction, cytokine release, and APOE-ε4 if pathways such as autophagy and other mechanisms of programmed cell death are left unchecked.

Emerging mechanistic insights of selective autophagy in hepatic diseases

Macroautophagy (hereafter referred to as autophagy), a highly conserved metabolic process, regulates cellular homeostasis by degrading dysfunctional cytosolic constituents and invading pathogens via the lysosomal system. In addition, autophagy selectively recycles specific organelles such as damaged mitochondria (via mitophagy), and lipid droplets (LDs; via lipophagy) or eliminates specialized intracellular pathogenic microorganisms such as hepatitis B virus (HBV) and coronaviruses (via virophagy). Selective autophagy, particularly mitophagy, plays a key role in the preservation of healthy liver physiology, and its dysfunction is connected to the pathogenesis of a wide variety of liver diseases. For example, lipophagy has emerged as a defensive mechanism against chronic liver diseases. There is a prominent role for mitophagy and lipophagy in hepatic pathologies including non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC), and drug-induced liver injury. Moreover, these selective autophagy pathways including virophagy are being investigated in the context of viral hepatitis and, more recently, the coronavirus disease 2019 (COVID-19)-associated hepatic pathologies. The interplay between diverse types of selective autophagy and its impact on liver diseases is briefly addressed. Thus, modulating selective autophagy (e.g., mitophagy) would seem to be effective in improving liver diseases. Considering the prominence of selective autophagy in liver physiology, this review summarizes the current understanding of the molecular mechanisms and functions of selective autophagy (mainly mitophagy and lipophagy) in liver physiology and pathophysiology. This may help in finding therapeutic interventions targeting hepatic diseases via manipulation of selective autophagy.

The interplay between selective types of (macro)autophagy: Mitophagy and xenophagy

Autophagy is a physiological response, activated by a myriad of endogenous and exogenous cues, including DNA damage, perturbation of proteostasis, depletion of nutrients or oxygen and pathogen infection. Upon sensing those stimuli, cells employ multiple non-selective and selective autophagy pathways to promote fitness and survival. Importantly, there are a variety of selective types of autophagy. In this review we will focus on autophagy of bacteria (xenophagy) and autophagy of mitochondria (mitophagy). We provide a brief introduction to bulk autophagy, as well as xenophagy and mitophagy, highlighting their common molecular factors. We also describe the role of xenophagy and mitophagy in the detection and elimination of pathogens by the immune system and the adaptive mechanisms that some pathogens have developed through evolution to escape the host autophagic response. Finally, we summarize the recent articles (from the last five years) linking bulk autophagy with xenophagy and/or mitophagy in the context on developmental biology, cancer and metabolism.

Network analysis of the autophagy biochemical network in relation to various autophagy-targeted proteins found among SARS-CoV-2 variants of concern

Autophagy is an important cellular process that triggers a coordinated action involving multiple individual proteins and protein complexes while SARS-CoV-2 (SARS2) was found to both hinder autophagy to evade host defense and utilize autophagy for viral replication. Interestingly, the possible significant stages of the autophagy biochemical network in relation to the corresponding autophagy-targeted SARS2 proteins from the different variants of concern (VOC) were never established. In this study, we performed the following: autophagy biochemical network design and centrality analyses; generated autophagy-targeted SARS2 protein models; and superimposed protein models for structural comparison. We identified 2 significant biochemical pathways (one starts from the ULK complex and the other starts from the PI3P complex) within the autophagy biochemical network. Similarly, we determined that the autophagy-targeted SARS2 proteins (Nsp15, M, ORF7a, ORF3a, and E) are structurally conserved throughout the different SARS2 VOC suggesting that the function of each protein is preserved during SARS2 evolution. Interestingly, among the autophagy-targeted SARS2 proteins, the M protein coincides with the 2 significant biochemical pathways we identified within the autophagy biochemical network. In this regard, we propose that the SARS2 M protein is the main determinant that would influence autophagy outcome in regard to SARS2 infection.

Temporal proteomic analyses of human lung cells distinguish high pathogenicity influenza viruses and coronaviruses from low pathogenicity viruses

Newly re-emerging viruses are of significant global concern. In late 2019, a new coronavirus, SARS-CoV-2, emerged in China and soon spread worldwide, causing the COVID-19 pandemic, which to date has caused >6 M deaths. There has been a wealth of studies on this new virus since its emergence. The coronaviruses consist of many animal and human pathogens, with some of the human coronavirus, such as strain OC43, normally causing only mild cold-like symptoms. Viruses usurp host cellular processes to successfully replicate. We used tandem mass tag mass spectrometry-based proteomic analyses of human lung MRC-5 cells infected with OC43 for various periods of time to delineate virus-induced host cell alterations. Numerous proteins involved in lipid metabolism, molecular transport, small molecule biochemistry, cell death and survival, humoral immune response, and inflammatory response were dysregulated. Comparison of our findings to previous studies that examined a range of differentially pathogenic influenza A viruses (IAV), and to SARS-CoV-2 data, revealed that proteins involved in the cell cycle, cytokine signaling, DNA replication, and anti-inflammatory responses were generally similarly affected by virtually all tested IAV and CoV. However, proteins involved in necrosis, protein metabolism, ECM regulation, and signal transduction were generally different. In addition, the more pathogenic CoV and IAV activated Rb-dependent repression of E2F-mediated transcription, whereas less pathogenic influenza and coronaviruses either inhibited or had no effect on this pathway.

Functional characterization of nutraceuticals using spectral clustering: Centrality of caveolae-mediated endocytosis for management of nitric oxide and vitamin D deficiencies and atherosclerosis

It is well recognized that redox imbalance, nitric oxide (NO), and vitamin D deficiencies increase risk of cardiovascular, metabolic, and infectious diseases. However, clinical studies assessing efficacy of NO and vitamin D supplementation have failed to produce unambiguous efficacy outcomes suggesting that the understanding of the pharmacologies involved is incomplete. This raises the need for using systems pharmacology tools to better understand cause-effect relationships at biological systems levels. We describe the use of spectral clustering methodology to analyze protein network interactions affected by a complex nutraceutical, Cardio Miracle (CM), that contains arginine, citrulline, vitamin D, and antioxidants. This examination revealed that interactions between protein networks affected by these substances modulate functions of a network of protein complexes regulating caveolae-mediated endocytosis (CME), TGF beta activity, vitamin D efficacy and host defense systems. Identification of this regulatory scheme and the working of embedded reciprocal feedback loops has significant implications for treatment of vitamin D deficiencies, atherosclerosis, metabolic and infectious diseases such as COVID-19.

Wheat Germ Spermidine and Clove Eugenol in Combination Stimulate Autophagy In Vitro Showing Potential in Supporting the Immune System against Viral Infections

Impaired autophagy, responsible for increased inflammation, constitutes a risk factor for the more severe COVID-19 outcomes. Spermidine (SPD) is a known autophagy modulator and supplementation for COVID-19 risk groups (including the elderly) is recommended. However, information on the modulatory effects of eugenol (EUG) is scarce. Therefore, the effects of SPD and EUG, both singularly and in combination, on autophagy were investigated using different cell lines (HBEpiC, SHSY5Y, HUVEC, Caco-2, L929 and U937). SPD (0.3 mM), EUG (0.2 mM) and 0.3 mM SPD + 0.2 mM EUG, significantly increased autophagy using the hallmark measure of LC3-II protein accumulation in the cell lines without cytotoxic effects. Using Caco-2 cells as a model, several crucial autophagy proteins were upregulated at all stages of autophagic flux in response to the treatments. This effect was verified by the activation/differentiation and migration of U937 monocytes in a three-dimensional reconstituted intestinal model (Caco-2, L929 and U937 cells). Comparable benefits of SPD, EUG and SPD + EUG in inducing autophagy were shown by the protection of Caco-2 and L929 cells against lipopolysaccharide-induced inflammation. SPD + EUG is an innovative dual therapy capable of stimulating autophagy and reducing inflammation in vitro and could show promise for COVID-19 risk groups.

Parkinson’s Disease and SARS-CoV-2 Infection: Particularities of Molecular and Cellular Mechanisms Regarding Pathogenesis and Treatment

Accumulating data suggest that chronic neuroinflammation-mediated neurodegeneration is a significant contributing factor for progressive neuronal and glial cell death in age-related neurodegenerative pathology. Furthermore, it could be encountered as long-term consequences in some viral infections, including post-COVID-19 Parkinsonism-related chronic sequelae. The current systematic review is focused on a recent question aroused during the pandemic’s successive waves: are there post-SARS-CoV-2 immune-mediated reactions responsible for promoting neurodegeneration? Does the host’s dysregulated immune counter-offensive contribute to the pathogenesis of neurodegenerative diseases, emerging as Parkinson’s disease, in a complex interrelation between genetic and epigenetic risk factors? A synthetic and systematic literature review was accomplished based on the ”Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses” (PRISMA) methodology, including registration on the specific online platform: International prospective register of systematic reviews—PROSPERO, no. 312183. Initially, 1894 articles were detected. After fulfilling the five steps of the selection methodology, 104 papers were selected for this synthetic review. Documentation was enhanced with a supplementary 47 bibliographic resources identified in the literature within a non-standardized search connected to the subject. As a final step of the PRISMA method, we have fulfilled a Population-Intervention-Comparison-Outcome-Time (PICOT)/Population-Intervention-Comparison-Outcome-Study type (PICOS)—based metanalysis of clinical trials identified as connected to our search, targeting the outcomes of rehabilitative kinesitherapeutic interventions compared to clinical approaches lacking such kind of treatment. Accordingly, we identified 10 clinical trials related to our article. The multi/interdisciplinary conventional therapy of Parkinson’s disease and non-conventional multitarget approach to an integrative treatment was briefly analyzed. This article synthesizes the current findings on the pathogenic interference between the dysregulated complex mechanisms involved in aging, neuroinflammation, and neurodegeneration, focusing on Parkinson’s disease and the acute and chronic repercussions of COVID-19. Time will tell whether COVID-19 neuroinflammatory events could trigger long-term neurodegenerative effects and contribute to the worsening and/or explosion of new cases of PD. The extent of the interrelated neuropathogenic phenomenon remains obscure, so further clinical observations and prospective longitudinal cohort studies are needed.

Co-expression analysis to identify key modules and hub genes associated with COVID-19 in platelets

Corona virus disease 2019 (COVID-19) increases the risk of cardiovascular occlusive/thrombotic events and is linked to poor outcomes. The underlying pathophysiological processes are complex, and remain poorly understood. To this end, platelets play important roles in regulating the cardiovascular system, including via contributions to coagulation and inflammation. There is ample evidence that circulating platelets are activated in COVID-19 patients, which is a primary driver of the observed thrombotic outcome. However, the comprehensive molecular basis of platelet activation in COVID-19 disease remains elusive, which warrants more investigation. Hence, we employed gene co-expression network analysis combined with pathways enrichment analysis to further investigate the aforementioned issues. Our study revealed three important gene clusters/modules that were closely related to COVID-19. These cluster of genes successfully identify COVID-19 cases, relative to healthy in a separate validation data set using machine learning, thereby validating our findings. Furthermore, enrichment analysis showed that these three modules were mostly related to platelet metabolism, protein translation, mitochondrial activity, and oxidative phosphorylation, as well as regulation of megakaryocyte differentiation, and apoptosis, suggesting a hyperactivation status of platelets in COVID-19. We identified the three hub genes from each of three key modules according to their intramodular connectivity value ranking, namely: COPE, CDC37, CAPNS1, AURKAIP1, LAMTOR2, GABARAP MT-ND1, MT-ND5, and MTRNR2L12. Collectively, our results offer a new and interesting insight into platelet involvement in COVID-19 disease at the molecular level, which might aid in defining new targets for treatment of COVID-19–induced thrombosis.

COVID-19 and Retinal Degenerative Diseases: Promising link “Kaempferol”

Coronavirus disease (COVID-19) outbreak has caused unprecedented global disruption since 2020. Approximately 238 million people are affected worldwide where the elderly succumb to mortality. Post-COVID syndrome and its side effects have popped up with several health hazards, such as macular degeneration and vision loss. It thus necessitates better medical care and management of our dietary practices. Natural flavonoids have been included in traditional medicine and have also been used safely against COVID-19 and several other diseases. Kaempferol is an essential flavonoid that has been demonstrated to influence several vital cellular signaling pathways involved in apoptosis, angiogenesis, inflammation, and autophagy. In this review, we emphasize the plausible regulatory effects of Kaempferol on hallmarks of COVID-19 and macular degeneration.

Coronavirus Usurps the Autophagy-Lysosome Pathway and Induces Membranes Rearrangement for Infection and Pathogenesis

Autophagy is a crucial and conserved homeostatic mechanism for early defense against viral infections. Recent studies indicate that coronaviruses (CoVs) have evolved various strategies to evade the autophagy–lysosome pathway. In this minireview, we describe the source of double-membrane vesicles during CoV infection, which creates a microenvironment that promotes viral RNA replication and virion synthesis and protects the viral genome from detection by the host. Firstly, CoVs hijack autophagy initiation through non-structural proteins and open-reading frames, leading to the use of non-nucleated phagophores and omegasomes for autophagy-derived double-membrane vesicles. Contrastingly, membrane rearrangement by hijacking ER-associated degradation machinery to form ER-derived double-membrane vesicles independent from the typical autophagy process is another important routine for the production of double-membrane vesicles. Furthermore, we summarize the molecular mechanisms by which CoV non-structural proteins and open-reading frames are used to intercept autophagic flux and thereby evade host clearance and innate immunity. A comprehensive understanding of the above mechanisms may contribute to developing novel therapies and clinical drugs against coronavirus disease 2019 (COVID-19) in the future.

Autophagy in Virus Infection: A Race between Host Immune Response and Viral Antagonism

Virus-infected cells trigger a robust innate immune response and facilitate virus replication. Here, we review the role of autophagy in virus infection, focusing on both pro-viral and anti-viral host responses using a select group of viruses. Autophagy is a cellular degradation pathway operated at the basal level to maintain homeostasis and is induced by external stimuli for specific functions. The degradative function of autophagy is considered a cellular anti-viral immune response. However, autophagy is a double-edged sword in viral infection; viruses often benefit from it, and the infected cells can also use it to inhibit viral replication. In addition to viral regulation, autophagy pathway proteins also function in autophagy-independent manners to regulate immune responses. Since viruses have co-evolved with hosts, they have developed ways to evade the anti-viral autophagic responses of the cells. Some of these mechanisms are also covered in our review. Lastly, we conclude with the thought that autophagy can be targeted for therapeutic interventions against viral diseases.

Differential Co-Expression Network Analysis Reveals Key Hub-High Traffic Genes as Potential Therapeutic Targets for COVID-19 Pandemic

Background

The recent emergence of COVID-19, rapid worldwide spread, and incomplete knowledge of molecular mechanisms underlying SARS-CoV-2 infection have limited development of therapeutic strategies. Our objective was to systematically investigate molecular regulatory mechanisms of COVID-19, using a combination of high throughput RNA-sequencing-based transcriptomics and systems biology approaches.

Methods

RNA-Seq data from peripheral blood mononuclear cells (PBMCs) of healthy persons, mild and severe 17 COVID-19 patients were analyzed to generate a gene expression matrix. Weighted gene co-expression network analysis (WGCNA) was used to identify co-expression modules in healthy samples as a reference set. For differential co-expression network analysis, module preservation and module-trait relationships approaches were used to identify key modules. Then, protein-protein interaction (PPI) networks, based on co-expressed hub genes, were constructed to identify hub genes/TFs with the highest information transfer (hub-high traffic genes) within candidate modules.

Results

Based on differential co-expression network analysis, connectivity patterns and network density, 72% (15 of 21) of modules identified in healthy samples were altered by SARS-CoV-2 infection. Therefore, SARS-CoV-2 caused systemic perturbations in host biological gene networks. In functional enrichment analysis, among 15 non-preserved modules and two significant highly-correlated modules (identified by MTRs), 9 modules were directly related to the host immune response and COVID-19 immunopathogenesis. Intriguingly, systemic investigation of SARS-CoV-2 infection identified signaling pathways and key genes/proteins associated with COVID-19's main hallmarks, e.g., cytokine storm, respiratory distress syndrome (ARDS), acute lung injury (ALI), lymphopenia, coagulation disorders, thrombosis, and pregnancy complications, as well as comorbidities associated with COVID-19, e.g., asthma, diabetic complications, cardiovascular diseases (CVDs), liver disorders and acute kidney injury (AKI). Topological analysis with betweenness centrality (BC) identified 290 hub-high traffic genes, central in both co-expression and PPI networks. We also identified several transcriptional regulatory factors, including NFKB1, HIF1A, AHR, and TP53, with important immunoregulatory roles in SARS-CoV-2 infection. Moreover, several hub-high traffic genes, including IL6, IL1B, IL10, TNF, SOCS1, SOCS3, ICAM1, PTEN, RHOA, GDI2, SUMO1, CASP1, IRAK3, HSPA5, ADRB2, PRF1, GZMB, OASL, CCL5, HSP90AA1, HSPD1, IFNG, MAPK1, RAB5A, and TNFRSF1A had the highest rates of information transfer in 9 candidate modules and central roles in COVID-19 immunopathogenesis.

Conclusion

This study provides comprehensive information on molecular mechanisms of SARS-CoV-2-host interactions and identifies several hub-high traffic genes as promising therapeutic targets for the COVID-19 pandemic.

Molecular pathways involved in COVID-19 and potential pathway-based therapeutic targets

Deciphering the molecular downstream consequences of severe acute respiratory syndrome coronavirus (SARS-CoV)- 2 infection is important for a greater understanding of the disease and treatment planning. Furthermore, greater understanding of the underlying mechanisms of diagnostic and therapeutic strategies can help in the development of vaccines and drugs against COVID-19. At present, the molecular mechanisms of SARS-CoV-2 in the host cells are not sufficiently comprehended. Some of the mechanisms are proposed considering the existing similarities between SARS-CoV-2 and the other members of the β-CoVs, and others are explained based on studies advanced in the structure and function of SARS-CoV-2. In this review, we endeavored to map the possible mechanisms of the host response following SARS-CoV-2 infection and surveyed current research conducted by in vitro, in vivo and human observations, as well as existing suggestions. We addressed the specific signaling events that can cause cytokine storm and demonstrated three forms of cell death signaling following virus infection, including apoptosis, pyroptosis, and necroptosis. Given the elicited signaling pathways, we introduced possible pathway-based therapeutic targets; ADAM17 was especially highlighted as one of the most important elements of several signaling pathways involved in the immunopathogenesis of COVID-19. We also provided the possible drug candidates against these targets. Moreover, the cytokine-cytokine receptor interaction pathway was found as one of the important cross-talk pathways through a pathway-pathway interaction analysis for SARS-CoV-2 infection.

Citicoline and COVID-19-Related Cognitive and Other Neurologic Complications

With growing concerns about COVID-19’s hyperinflammatory condition and its potentially damaging impact on the neurovascular system, there is a need to consider potential treatment options for managing short- and long-term effects on neurological complications, especially cognitive function. While maintaining adequate structure and function of phospholipid in brain cells, citicoline, identical to the natural metabolite phospholipid phosphatidylcholine precursor, can contribute to a variety of neurological diseases and hypothetically toward post-COVID-19 cognitive effects. In this review, we comprehensively describe in detail the potential citicoline mechanisms as adjunctive therapy and prevention of COVID-19-related cognitive decline and other neurologic complications through citicoline properties of anti-inflammation, anti-viral, neuroprotection, neurorestorative, and acetylcholine neurotransmitter synthesis, and provide a recommendation for future clinical trials.

Translation Inhibitors Activate Autophagy Master Regulators TFEB and TFE3

The autophagy-lysosome pathway is a major protein degradation pathway stimulated by multiple cellular stresses, including nutrient or growth factor deprivation, hypoxia, misfolded proteins, damaged organelles, and intracellular pathogens. Recent studies have revealed that transcription factor EB (TFEB) and transcription factor E3 (TFE3) play a pivotal role in the biogenesis and functions of autophagosome and lysosome. Here we report that three translation inhibitors (cycloheximide, lactimidomycin, and rocaglamide A) can facilitate the nuclear translocation of TFEB/TFE3 via dephosphorylation and 14-3-3 dissociation. In addition, the inhibitor-mediated TFEB/TFE3 nuclear translocation significantly increases the transcriptional expression of their downstream genes involved in the biogenesis and function of autophagosome and lysosome. Furthermore, we demonstrated that translation inhibition increased autophagosome biogenesis but impaired the degradative autolysosome formation because of lysosomal dysfunction. These results highlight the previously unrecognized function of the translation inhibitors as activators of TFEB/TFE3, suggesting a novel biological role of translation inhibition in autophagy regulation.

Targeting autophagy with natural products to prevent SARS-CoV-2 infection

Autophagy is a catabolic process that maintains internal homeostasis and energy balance through the lysosomal degradation of redundant or damaged cellular components. During virus infection, autophagy is triggered both in parenchymal and in immune cells with different finalistic objectives: in parenchymal cells, the goal is to destroy the virion particle while in macrophages and dendritic cells the goal is to expose virion-derived fragments for priming the lymphocytes and initiate the immune response. However, some viruses have developed a strategy to subvert the autophagy machinery to escape the destructive destiny and instead exploit it for virion assembly and exocytosis. Coronaviruses (like SARS-CoV-2) possess such ability. The autophagy process requires a set of proteins that constitute the core machinery and is controlled by several signaling pathways. Here, we report on natural products capable of interfering with SARS-CoV-2 cellular infection and replication through their action on autophagy. The present study provides support to the use of such natural products as adjuvant therapeutics for the management of COVID-19 pandemic to prevent the virus infection and replication, and so mitigating the progression of the disease.