Molecular Docking and Simulation Analysis of Cyclopeptides as Anticancer Agents

Background: Cancer is a leading cause of death for people worldwide, in addition to the rise in mortality rates attributed to the Covid epidemic. This allows scientists to do additional research. Here, we have selected Integerrimide A, cordy heptapeptide, and Oligotetrapeptide as the three cyclic proteins that will be further studied and investigated in this context.Methods: Docking research was carried out using the protein complexes 1FKB and 1YET, downloaded from the PDB database and used in the docking investigations. Cyclopeptides have been reported to bind molecularly to human HSP90 (Heat shock protein) and FK506. It was possible to locate HSP90 in Protein Data Banks 1YET and 1FKB. HSP90 was retrieved from Protein Data Bank 1YET and 1FKB. Based on these findings, it is possible that the anticancer effects of Int A, Cordy, and Oligo substances could be due to their ability to inhibit the mTOR rapamycin binding domain and the HSP90 Geldanamycin binding domain via the mTOR and mTOR chaperone pathways. During the calculation, there were three stages: system development, energy reduction, and molecular dynamics (also known as molecular dynamics). Each of the three compounds demonstrated a binding affinity for mTOR's Rapamycin binding site that ranged from -6.80 to -9.20 Kcal/mol (FKB12).Results: An inhibition constant Ki of 181.05 nM characterized Cordy A with the highest binding affinity (-9.20 Kcal/mol). Among the three tested compounds, Cordy A was selected for MD simulation. HCT116 and B16F10 cell lines were used to test each compound's anticancer efficacy. Doxorubicin was used as a standard drug. The cytotoxic activity of substances Int A, Cordy A, and Oligo on HCT116 cell lines was found to be 77.65 μM, 145.36 μM, and 175.54 μM when compared to Doxorubicin 48.63 μM, similarly utilizing B16F10 cell lines was found to be 68.63 μM, 127.63 μM, and 139.11 μM to Doxorubicin 45.25 μM.Conclusion: Compound Cordy A was more effective than any other cyclic peptides tested in this investigation.

The Role of Hsp70 in Adaptation to Adverse Conditions and Its Possible Medical Application.

In the present era of global warming and dramatically increased environmental pollution posing a threat to animal life, the understanding and manipulation of organisms' resources of stress tolerance is apparently a question of survival. Heat stress and other forms of stressful factors induce a highly organized response of organisms at the cellular level where heat shock proteins (Hsps) and in particular Hsp70 family of chaperones are among the major players in the protection from the environmental challenge. The present review article summarizes the peculiarities of the Hsp70 family of proteins protective functions being a result of many millions of years of adaptive evolution. It discusses the molecular structure and specific details of hsp70 gene regulation in various organisms, living in diverse climatic zones, with a special emphasis on the protective role of Hsp70 in adverse conditions of the environment. The review discusses the molecular mechanisms underlying Hsp70-specific properties that emerged in the course of adaptation to harsh environmental conditions. This review also includes the data on the anti-inflammatory role of Hsp70 and the involvement of endogenous and recombinant Hsp70 (recHsp70) in proteostatic machinery in various pathologies including neurodegenerative ones such as Alzheimer's and Parkinson's diseases in rodent model organisms and humans in vivo and in vitro. Specifically, the role of Hsp70 as an indicator of disease type and severity and the use of recHsp70 in several pathologies are discussed. The review discusses different roles exhibited by Hsp70 in various diseases including the dual and sometimes antagonistic role of this chaperone in various forms of cancer and viral infection including the SARS-Cov-2 case. Since Hsp70 apparently plays an important role in many diseases and pathologies and has significant therapeutic potential there is a dire need to develop cheap recombinant Hsp70 production and further investigate the interaction of externally supplied and endogenous Hsp70 in chaperonotherapy.

The Link Between Heat Shock Proteins, Renin-Angiotensin System, and the Coagulation Cascade in the Pathogenesis of the Coronavirus-19 Disease.

INTRODUCTION: Understanding the pathogenesis of COVID-19 is integral for its successful treatment. METHODS: Available literature on the relationship between COVID-19, heat shock proteins (HSP), and the renin-angiotensin-aldosterone (RAAS) system were searched and used to hypothesize how HSP can be targeted in COVID-19. RESULTS: During SARS-CoV-2 cellular entry, the ACE-2 receptor is downregulated. This leads to the augmentation of angiotensin-2/AT1 receptor axis along with attenuation of the ACE-2/angiotensin1-7/Mas axis. Heat shock proteins are key stabilizing molecules in various pathways.In the heart and vessels, HSP-90 and HSP-60 can facilitate angiotensin-2-mediated myocardial injury and endothelial cell activation. HSP-60-TLR4/CD14 complex formation stabilizes IκB-kinase (IKK) potentiating NF-κB activation. HSPs in lungs and kidneys have antioxidant, vasodilatory, and anti-inflammatory actions and may be protective against the effects of RAAS. Stress-induced HSP-70 has a role in complement-mediated microvascular injury such as has been demonstrated in COVID-19. SARS-CoV-2 can induce autophagy via Beclin-1 and ER (endoplasmic reticular) stress via BIP. These two can be potential targets in the HSP environment. CONCLUSION: Various HSP molecules can modulate the effects of the renin-angiotensin-aldosterone (RAAS) system and thus may have a potential role in the pathogenesis of COVID-19.

Collagen-Specific HSP47+ Myofibroblasts and CD163+ Macrophages Identify Profibrotic Phenotypes in Deceased Hearts With SARS-CoV-2 Infections.

Background Cardiac fibrosis complicates SARS-CoV-2 infections and has been linked to arrhythmic complications in survivors. Accordingly, we sought evidence of increased HSP47 (heat shock protein 47), a stress-inducible chaperone protein that regulates biosynthesis and secretion of procollagen in heart tissue, with the goal of elucidating molecular mechanisms underlying cardiac fibrosis in subjects with this viral infection. Methods and Results Using human autopsy tissue, immunofluorescence, and immunohistochemistry, we quantified Hsp47+ cells and collagen α 1(l) in hearts from people with SARS-CoV-2 infections. Because macrophages are also linked to inflammation, we measured CD163+ cells in the same tissues. We observed irregular groups of spindle-shaped HSP47+ and CD163+ cells as well as increased collagen α 1(I) deposition, each proximate to one another in "hot spots" of ≈40% of hearts after SARS-CoV-2 infection (HSP47+ P<0.05 versus nonfibrotics and P<0.001 versus controls). Because HSP47+ cells are consistent with myofibroblasts, subjects with hot spots are termed "profibrotic." The remaining 60% of subjects dying with COVID-19 without hot spots are referred to as "nonfibrotic." No control subject exhibited hot spots. Conclusions Colocalization of myofibroblasts, M2(CD163+) macrophages, and collagen α 1(l) may be the first evidence of a COVID-19-related "profibrotic phenotype" in human hearts in situ. The potential public health and diagnostic implications of these observations require follow-up to further define mechanisms of viral-mediated cardiac fibrosis.

Comparison of allosteric signaling in DnaK and BiP using mutual information between simulated residue conformations.

The heat shock protein 70 kDa (Hsp70) chaperone system serves as a critical component of protein quality control across a wide range of prokaryotic and eukaryotic organisms. Divergent evolution and specialization to particular organelles have produced numerous Hsp70 variants which share similarities in structure and general function, but differ substantially in regulatory aspects, including conformational dynamics and activity modulation by cochaperones. The human Hsp70 variant BiP (also known as GRP78 or HSPA5) is of therapeutic interest in the context of cancer, neurodegenerative diseases, and viral infection, including for treatment of the pandemic virus SARS-CoV-2. Due to the complex conformational rearrangements and high sequential variance within the Hsp70 protein family, it is in many cases poorly understood which amino acid mutations are responsible for biochemical differences between protein variants. In this study, we predicted residues associated with conformational regulation of human BiP and Escherichia coli DnaK. Based on protein structure networks obtained from molecular dynamics simulations, we analyzed the shared information between interaction timelines to highlight residue positions with strong conformational coupling to their environment. Our predictions, which focus on the binding processes of the chaperone's substrate and cochaperones, indicate residues filling potential signaling roles specific to either DnaK or BiP. By combining predictions of individual residues into conformationally coupled chains connecting ligand binding sites, we predict a BiP specific secondary signaling pathway associated with substrate binding. Our study sheds light on mechanistic differences in signaling and regulation between Hsp70 variants, which provide insights relevant to therapeutic applications of these proteins.

Targeting heat shock proteins 90 and 70: A promising remedy for both autoimmune bullous diseases and COVID-19.

Heat shock proteins (Hsps), including Hsp90 and Hsp70, are intra- and extracellular molecules implicated in cellular homeostasis and immune processes and are induced by cell stress such as inflammation and infection. Autoimmune bullous disorders (AIBDs) and COVID-19 represent potentially life-threatening inflammatory and infectious diseases, respectively. A significant portion of AIBDs remain refractory to currently available immunosuppressive therapies, which may represent a risk factor for COVID-19, and suffer from treatment side-effects. Despite advances in vaccination, there is still a need to develop new therapeutic approaches targeting SARS-CoV-2, especially considering vaccine hesitancy, logistical distribution challenges, and breakthrough infections. In this mini review, we briefly summarize the role of targeting Hsp90/70 as a promising double-edged sword in the therapy of AIBDs and COVID-19.

Host cell stress response as a predictor of COVID-19 infectivity and disease progression.

The coronavirus disease (COVID-19) caused by a coronavirus identified in December 2019 has caused a global pandemic. COVID-19 was declared a pandemic in March 2020 and has led to more than 6.3 million deaths. The pandemic has disrupted world travel, economies, and lifestyles worldwide. Although vaccination has been an effective tool to reduce the severity and spread of the disease there is a need for more concerted approaches to fighting the disease. COVID-19 is characterised as a severe acute respiratory syndrome . The severity of the disease is associated with a battery of comorbidities such as cardiovascular diseases, cancer, chronic lung disease, and renal disease. These underlying diseases are associated with general cellular stress. Thus, COVID-19 exacerbates outcomes of the underlying conditions. Consequently, coronavirus infection and the various underlying conditions converge to present a combined strain on the cellular response. While the host response to the stress is primarily intended to be of benefit, the outcomes are occasionally unpredictable because the cellular stress response is a function of complex factors. This review discusses the role of the host stress response as a convergent point for COVID-19 and several non-communicable diseases. We further discuss the merits of targeting the host stress response to manage the clinical outcomes of COVID-19.

Effect of HSP90AB1 on the replication of avian infectious bronchitis virus

The effects of heat shock protein HSPQOABl on the replication of avian infectious bronchitis virus(AIBV) were confirmed by using over expression and RNA interference methods. The results showed that over expression of HSPQOABI inhibited AIBV replication, whereas knockdown of HSPQOABl in- creased AIBV replication. These results indicated that HSPQOABI is a potential anti-viral host factor. These findings provide the basis for further study of the pathogenic mechanism of AIBV and anti-coronavirus infection.

HSP90 Modulates T2R Bitter Taste Receptor Nitric Oxide Production and Innate Immune Responses in Human Airway Epithelial Cells and Macrophages

Bitter taste receptors (T2Rs) are G protein-coupled receptors (GPCRs) expressed in various cell types including ciliated airway epithelial cells and macrophages. T2Rs in these two innate immune cell types are activated by bitter products, including those secreted by Pseudomonas aeruginosa, leading to Ca2+-dependent activation of endothelial nitric oxide (NO) synthase (eNOS). NO enhances mucociliary clearance and has direct antibacterial effects in ciliated epithelial cells. NO also increases phagocytosis by macrophages. Using biochemistry and live-cell imaging, we explored the role of heat shock protein 90 (HSP90) in regulating T2R-dependent NO pathways in primary sinonasal epithelial cells, primary monocyte-derived macrophages, and a human bronchiolar cell line (H441). Immunofluorescence showed that H441 cells express eNOS and T2Rs and that the bitter agonist denatonium benzoate activates NO production in a Ca2+- and HSP90-dependent manner in cells grown either as submerged cultures or at the air–liquid interface. In primary sinonasal epithelial cells, we determined that HSP90 inhibition reduces T2R-stimulated NO production and ciliary beating, which likely limits pathogen clearance. In primary monocyte-derived macrophages, we found that HSP-90 is integral to T2R-stimulated NO production and phagocytosis of FITC-labeled Escherichia coli and pHrodo-Staphylococcus aureus. Our study demonstrates that HSP90 serves as an innate immune modulator by regulating NO production downstream of T2R signaling by augmenting eNOS activation without impairing upstream Ca2+ signaling. These findings suggest that HSP90 plays an important role in airway antibacterial innate immunity and may be an important target in airway diseases such as chronic rhinosinusitis, asthma, or cystic fibrosis.

The capture of host cell's resources: The role of heat shock proteins and polyamines in SARS-COV-2 (COVID-19) pathway to viral infection.

The exposure of organisms and cells to unfavorable conditions such as increased temperature, antibiotics, reactive oxygen species, and viruses could lead to protein misfolding and cell death. The increased production of proteins such as heat shock proteins (HSPs) and polyamines has been linked to protein misfolding sequestration, thus maintaining, enhancing, and regulating the cellular system. For example, heat shock protein 40 (Hsp40) works hand in hand with Hsp70 and Hsp90 to successfully assist the newly synthesized proteins in folding properly. On the other hand, polyamines such as putrescine, spermidine, and spermine have been widely studied and reported to keep cells viable under harsh conditions, which are also involved in cell proliferation, differentiation, and growth. Polyamines are found in all living organisms, including humans and viruses. Some organisms have developed a mechanism to hijack mammalian host cell machinery for their benefit like viruses need polyamines for infection. Therefore, the role of HSPs and polyamines in SARS-CoV-2 (COVID-19) viral infection, how these molecules could delay the effectiveness of the current treatment in the market, and how COVID-19 relies on the host molecules for its successful infection are reviewed.

HSP90 Inhibitors Modulate SARS-CoV-2 Spike Protein Subunit 1-Induced Human Pulmonary Microvascular Endothelial Activation and Barrier Dysfunction.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused more than 5 million deaths worldwide. Multiple reports indicate that the endothelium is involved during SARS-Cov-2-related disease (COVID-19). Indeed, COVID-19 patients display increased thrombophilia with arterial and venous embolism and lung microcapillary thrombotic disease as major determinants of deaths. The pathophysiology of endothelial dysfunction in COVID-19 is not completely understood. We have investigated the role of subunit 1 of the SARS-CoV-2 spike protein (S1SP) in eliciting endothelial barrier dysfunction, characterized dose and time relationships, and tested the hypothesis that heat shock protein 90 (HSP90) inhibitors would prevent and repair such injury. S1SP activated (phosphorylated) IKBα, STAT3, and AKT and reduced the expression of intercellular junctional proteins, occludin, and VE-cadherin. HSP90 inhibitors (AT13387 and AUY-922) prevented endothelial barrier dysfunction and hyperpermeability and reduced IKBα and AKT activation. These two inhibitors also blocked S1SP-mediated barrier dysfunction and loss of VE-cadherin. These data suggest that spike protein subunit 1 can elicit, by itself, direct injury to the endothelium and suggest a role of HSP90 inhibitors in preserving endothelial functionality.

Sequence similarity of HSP65 of Mycobacterium bovis BCG with SARS-CoV-2 spike and nuclear proteins: may it predict an antigen-dependent immune protection of BCG against COVID-19?

The Bacillus Calmette-Guérin (BCG) vaccine is known to have protective effects not only against tuberculosis but also against other unrelated infectious diseases caused by different pathogens. Several epidemiological studies have also documented the beneficial influence of BCG vaccine in reducing both susceptibility to and severity of SARS-CoV-2 infection. The protective, non-specific effects of BCG vaccination would be related to an antigen-independent enhancement of the innate immunity, termed trained immunity. However, the knowledge that heat shock protein (HSP)65 is the main antigen of Mycobacterium bovis BCG prompted us to verify whether sequence similarity existed between HSP65 and SARS-CoV-2 spike (S) and nuclear (N) proteins that could support an antigen-driven immune protection of BCG vaccine. The results of the in silico investigation showed an extensive sequence similarity of HSP65 with both the viral proteins, especially SARS-CoV-2 S, that also involved the regions comprising immunodominant epitopes. The finding that the predicted B cell and CD4+ T cell epitopes of HSP65 shared strong similarity with the predicted B and T cell epitopes of both SARS-CoV-2 S and N would support the possibility of a cross-immune reaction of HSP65 of BCG with SARS-CoV-2.

Autoantibodies to heat shock protein 60, 70, and 90 are not altered in the anti-SARS-CoV-2 IgG-seropositive humans without or with mild symptoms.

Highly conserved heat shock proteins (Hsps) are localized in the cytoplasm and cellular organelles, and act as molecular chaperones or proteases. Members of Hsp families are released into the extracellular milieu under both normal and stress conditions. It is hypothesized that the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) has the potential to elicit autoimmunity due to molecular mimicry between human extracellular Hsps and immunogenic proteins of the virus. To confirm the above hypothesis, levels of circulating autoantibodies directed to the key human chaperones i.e., Hsp60, Hsp70, and Hsp90 in the anti-SARS-CoV-2 IgG-seropositive participants have been evaluated. Twenty-six healthy volunteers who got two doses of the mRNA vaccine encoding the viral spike protein, anti-SARS-CoV-2 IgG-positive participants (n = 15), and healthy naïve (anti-SARS-CoV-2 IgG-negative) volunteers (n = 51) have been included in this study. We found that the serum levels of anti-Hsp60, anti-Hsp70, and anti-Hsp90 autoantibodies of the IgG, IgM, or IgA isotype remained unchanged in either the anti-COVID-19-immunized humans or the anti-SARS-CoV-2 IgG-positive participants when compared to healthy naïve volunteers, as measured by enzyme-linked immunosorbent assay. Our results showing that the humoral immune response to SARS-CoV-2 did not include the production of anti-SARS-CoV-2 antibodies that also recognized extracellular heat shock protein 60, 70, and 90 represent a partial evaluation of the autoimmunity hypothesis stated above. Further testing for cell-based immunity will be necessary to fully evaluate this hypothesis.

First Virtual International Congress on Cellular and Organismal Stress Responses, November 5-6, 2020.

Members of the Cell Stress Society International (CSSI), Patricija van Oosten-Hawle (University of Leeds, UK), Mehdi Mollapour (SUNY Upstate Medical University, USA), Andrew Truman (University of North Carolina at Charlotte, USA) organized a new virtual meeting format which took place on November 5-6, 2020. The goal of this congress was to provide an international platform for scientists to exchange data and ideas among the Cell Stress and Chaperones community during the Covid-19 pandemic. Here we will highlight the summary of the meeting and acknowledge those who were honored by the CSSI.

P53 in acute respiratory distress syndrome.

P53 is a tumor suppressor protein, associated with strong anti-inflammatory activities. Recent evidence suggest that this transcription factor counteracts lung inflammatory diseases, including the lethal acute respiratory distress syndrome. Herein we provide a brief discussion on the relevant topic.

Covid-19, heat shock proteins, and autoimmune bullous diseases: a potential link deserving further attention.

A link between Covid-19 and development of autoimmunity has been reported. A possible explanation could be molecular mimicry between SARS-CoV-2 and human proteins. Peptide sharing has been found between antigenic epitopes of this virus and heat shock proteins (Hsp) 60 and 90, both of which are associated with autoimmune diseases including those of the bullous type. In particular, there is evidence for the latter Hsp acting as a pathophysiological factor and treatment target in autoimmune blistering dermatoses. Considering multimodal anti-inflammatory mechanisms of action of anti-Hsp90 treatment and drug repositioning results, it may be hypothesized that Hsp90 inhibition could also be a treatment option for cytokine storm-mediated acute respiratory distress syndrome in Covid-19 patients. Hence, although Covid-19-induced autoimmune bullous diseases have not been described in the literature so far, the potential relationship between Covid-19, Hsp, and these autoimmune disorders deserves further attention with respect to both pathophysiology and treatment.

Enhancing innate immunity against virus in times of COVID-19: Trying to untangle facts from fictions.

INTRODUCTION: In light of the current COVID-19 pandemic, during which the world is confronted with a new, highly contagious virus that suppresses innate immunity as one of its initial virulence mechanisms, thus escaping from first-line human defense mechanisms, enhancing innate immunity seems a good preventive strategy. METHODS: Without the intention to write an official systematic review, but more to give an overview of possible strategies, in this review article we discuss several interventions that might stimulate innate immunity and thus our defense against (viral) respiratory tract infections. Some of these interventions can also stimulate the adaptive T- and B-cell responses, but our main focus is on the innate part of immunity. We divide the reviewed interventions into: 1) lifestyle related (exercise, >7 h sleep, forest walking, meditation/mindfulness, vitamin supplementation); 2) Non-specific immune stimulants (letting fever advance, bacterial vaccines, probiotics, dialyzable leukocyte extract, pidotimod), and 3) specific vaccines with heterologous effect (BCG vaccine, mumps-measles-rubeola vaccine, etc). RESULTS: For each of these interventions we briefly comment on their definition, possible mechanisms and evidence of clinical efficacy or lack of it, especially focusing on respiratory tract infections, viral infections, and eventually a reduced mortality in severe respiratory infections in the intensive care unit. At the end, a summary table demonstrates the best trials supporting (or not) clinical evidence. CONCLUSION: Several interventions have some degree of evidence for enhancing the innate immune response and thus conveying possible benefit, but specific trials in COVID-19 should be conducted to support solid recommendations.

COVID-19 and heme oxygenase: novel insight into the disease and potential therapies.

The COVID-19 pandemic needs therapies that are presently available and safe. We propose that subjects with metabolic syndrome, old age, and male gender have the greatest morbidity and mortality and have low stress proteins, in particular, low intracellular heme oxygenase (HO-1), making them particularly vulnerable to the disease. Additionally, COVID-19's heme reduction may contribute to even lower HO-1. Low-grade inflammation associated with these risk factors contributes to triggering a cytokine storm that spreads to multi-organ failure and near death. The high mortality of those treated with ventilator assistance may partially be explained by ventilator-induced inflammation. The cytoprotective and anti-inflammatory properties of HO-1 can limit the infection's damage. A paradox of COVID-19 hospital admissions data suggests that fewer cigarette-smokers are admitted compared with non-smokers in the general population. This unexpected observation may result from smoke induction of HO-1. Therapies with anti-viral properties that raise HO-1 include certain anesthetics (sevoflurane or isoflurane), hemin, estrogen, statins, curcumin, resveratrol, and melatonin. Controlled trials of these HO-1 inducers should be done in order to prevent or treat COVID-19 disease.