The interplay of co-infections in shaping COVID-19 severity: Expanding the scope beyond SARS-CoV-2.

High mortality has been reported in severe cases of COVID-19. Emerging reports suggested that the severity is not only due to SARS-CoV-2 infection, but also due to coinfections by other pathogens exhibiting symptoms like COVID-19. During the COVID-19 pandemic, simultaneous respiratory coinfections with various viral (Retroviridae, Flaviviridae, Orthomyxoviridae, and Picoviridae) and bacterial (Mycobacteriaceae, Mycoplasmataceae, Enterobacteriaceae and Helicobacteraceae) families have been observed. These pathogens intensify disease severity by potentially augmenting SARSCoV-2 replication, inflammation, and modulation of signaling pathways. Coinfection emerges as a critical determinant of COVID-19 severity, principally instigated by heightened pro-inflammatory cytokine levels, as cytokine storm. Thereby, in co-infection scenario, the severity is also driven by the modulation of inflammatory signaling pathways by both pathogens possibly associated with interleukin, interferon, and cell death exacerbating the severity. In the current review, we attempt to understand the role of co- infections by other pathogens and their involvement in the severity of COVID-19.

Exploring the cytotoxic potential of biflavones of Araucaria cunninghamii: Precise identification combined by LC-HRMS-metabolomics and database mining, targeted isolation, network pharmacology, in vitro cytotoxicity, and docking studies.

The leaves of Araucaria cunninghamii are known to be nonedible and toxic. Previous studies have identified biflavones in various Araucaria species. This study aimed to investigate the in vitro cytotoxicity of the isolated compounds from Araucaria cunninghamii after metabolomics and network pharmacological analysis. Methanol extract of Araucaria cunninghamii leaves was subjected to bioassay-guided fractionation. The active fraction was analyzed using LC-HRMS, through strategic database mining, by comparing the data to the Dictionary of Natural Products to identify 12 biflavones, along with abietic acid, beta-sitosterol, and phthalate. Eight compounds were screened for network pharmacology study, where in silico ADME analysis, prediction of gene targets, compound-gene-pathway network and hierarchical network analysis, protein-protein interaction, KEGG pathway, and Gene Ontology analyses were done, that showed PI3KR1, EGFR, GSK3B, and ABCB1 as the common targets for all the compounds that may act in the gastric cancer pathway. Simultaneously, four biflavones were isolated via chromatography and identified through NMR as dimeric apigenin with varying methoxy substitutions. Cytotoxicity study against the AGS cell line for gastric cancer showed that AC1 biflavone (IC50 90.58 µM) exhibits the highest cytotoxicity and monomeric apigenin (IC50 174.5 µM) the lowest. Besides, the biflavones were docked to the previously identified targets to analyze their binding affinities, and all the ligands were found to bind with energy ≤-7 Kcal/mol.

Gut dysbiosis and neurological modalities: An engineering approach via proteomic analysis of gut-brain axis.

The human gut microbiota is a complex and dynamic community of microorganisms, that influence metabolic, neurodevelopmental, and immune pathways. Microbial dysbiosis, characterized by changes in microbial diversity and relative abundances, is implicated in the development of various chronic neurological and neurodegenerative disorders. These disorders are marked by the accumulation of pathological protein aggregates, leading to the progressive loss of neurons and behavioural functions. Dysregulations in protein-protein interaction networks and signalling complexes, critical for normal brain function, are common in neurological disorders but challenging to unravel, particularly at the neuron and synapse-specific levels. To advance therapeutic strategies, a deeper understanding of neuropathogenesis, especially during the progressive disease phase, is needed. Biomarkers play a crucial role in identifying disease pathophysiology and monitoring disease progression. Proteomics, a powerful technology, shows promise in accelerating biomarker discovery and aiding in the development of novel treatments. In this chapter, we provide an in-depth overview of how proteomic techniques, utilizing various biofluid samples from patients with neurological conditions and diverse animal models, have contributed valuable insights into the pathogenesis of numerous neurological disorders. We also discuss the current state of research, potential challenges, and future directions in proteomic approaches to unravel neuro-pathological conditions.

Gut-brain axis interplay via STAT3 pathway: Implications of Helicobacter pylori derived secretome on inflammation and Alzheimer's disease.

Helicobacter pylori is a pathogenic bacterium that causes gastritis and gastric carcinoma. Besides gastric complications its potential link with gut-brain axis disruption and neurological disorders has also been reported. The current study investigated the plausible role and its associated molecular mechanism underlying H. pylori mediated gut-brain axis disruption and neuroinflammation leading to neurological modalities like Alzheimer's disease (AD). We have chosen the antimicrobial resistant and susceptible H. pylori strains on the basis of broth dilution method. We have observed the increased inflammatory response exerted by H. pylori strains in the gastric as well as in the neuronal compartment after treatment with Helicobacter pylori derived condition media (HPCM). Further, elevated expression of STAT1, STAT3, and AD-associated proteins- APP and APOE4 was monitored in HPCM-treated neuronal and neuron-astrocyte co-cultured cells. Excessive ROS generation has been found in these cells. The HPCM treatment to LN229 causes astrogliosis, evidenced by increased glial fibrillary acidic protein. Our results indicate the association of STAT3 as an important regulator in the H. pylori-mediated pathogenesis in neuronal cells. Notably, the inhibition of STAT3 by its specific inhibitor, BP-1-102, reduced the expression of pSTAT3 and AD markers in neuronal compartment induced by HPCM. Thus, our study demonstrates that H. pylori infection exacerbates inflammation in AGS cells and modulates the activity of STAT3 regulatory molecules. H. pylori secretome could affect neurological compartments by promoting STAT3 activation and inducing the expression of AD-associated signature markers. Further, pSTAT-3 inhibition mitigates the H. pylori associated neuroinflammation and amyloid pathology.

Helicobacter pylori and Epstein-Barr virus infection in cell polarity alterations.

The asymmetrical distribution of the cellular organelles inside the cell is maintained by a group of cell polarity proteins. The maintenance of polarity is one of the vital host defense mechanisms against pathogens, and the loss of it contributes to infection facilitation and cancer progression. Studies have suggested that infection of viruses and bacteria alters cell polarity. Helicobacter pylori and Epstein-Barr virus are group I carcinogens involved in the progression of multiple clinical conditions besides gastric cancer (GC) and Burkitt's lymphoma, respectively. Moreover, the coinfection of both these pathogens contributes to a highly aggressive form of GC. H. pylori and EBV target the host cell polarity complexes for their pathogenesis. H. pylori-associated proteins like CagA, VacA OipA, and urease were shown to imbalance the cellular homeostasis by altering the cell polarity. Similarly, EBV-associated genes LMP1, LMP2A, LMP2B, EBNA3C, and EBNA1 also contribute to altered cell asymmetry. This review summarized all the possible mechanisms involved in cell polarity deformation in H. pylori and EBV-infected epithelial cells. We have also discussed deregulated molecular pathways like NF-κB, TGF-ß/SMAD, and ß-catenin in H. pylori, EBV, and their coinfection that further modulate PAR, SCRIB, or CRB polarity complexes in epithelial cells.

Unraveling the Aurora kinase A and Epstein-Barr nuclear antigen 1 axis in Epstein Barr virus associated gastric cancer.

Aurora kinase A (AURKA) is one of the crucial cell cycle regulators associated with gastric cancer. Here, we explored Epstein Barr Virus-induced gastric cancer progression through EBV protein EBNA1 with AURKA. We found that EBV infection enhanced cell proliferation and migration of AGS cells and upregulation of AURKA levels. AURKA knockdown markedly reduced the proliferation and migration of the AGS cells even with EBV infection. Moreover, MD-simulation data deciphered the probable connection between EBNA1 and AURKA. The in-vitro analysis through the transcript and protein expression showed that AURKA knockdown reduces the expression of EBNA1. Moreover, EBNA1 alone can enhance AURKA protein expression in AGS cells. Co-immunoprecipitation and NMR analysis between AURKA and EBNA1 depicts the interaction between two proteins. In addition, AURKA knockdown promotes apoptosis in EBV-infected AGS cells through cleavage of Caspase-3, -9, and PARP1. This study demonstrates that EBV oncogenic modulators EBNA1 possibly modulate AURKA in EBV-mediated gastric cancer progression.

Withania somnifera extract reduces gastric cancerous properties through inhibition of gankyrin in cellular milieu produced by Helicobacter pylori and Epstein Barr virus.

Helicobacter pylori and Epstein Barr virus (EBV) are group1 carcinogens and their role in Gastric cancer (GC) is well established. Previously we have shown that H. pylori and EBV appears to support aggressive gastric oncogenesis through the upregulation of oncoprotein Gankyrin. Natural plant active molecules have the potential to interrupt oncogenesis. Herein, we investigated the potential of Withania somnifera root extract (WSE) as a possible chemotherapeutic agent against host oncoprotein Gankyrin whose expression was altered by H. pylori and EBV-associated modified cellular milieu. The results show that WSE does not have any inhibitory effect on H. pylori and EBV-associated gene transcripts except for the lmps (lmp1, lmp2a, and lmp2B). Moreover, the WSE exert their anticancer activity via host cellular response and decreased the expression of cell-migratory (mmp3 and mmp7); cell-cycle regulator (pcna); antiapoptotic gene (bcl2); increased the expression of the proapoptotic gene (apaf1 and bax); and tumor suppressor (p53, prb, and pten). Knockdown of Gankyrin followed by the treatment of WSE also decreases the expression of TNF-ɑ, Akt, and elevated the expression of NFkB, PARP, Casp3, and Casp9. WSE also reduces cell migration, and genomic instability and forced the cells to commit programmed cell death. Moreover, molecular simulation studies revealed that out of eight active compounds of WSE, only four compounds such as withaferin A (WFA), withanoside IV (WA4), withanolide B (WNB), and withanolide D (WND) showed direct stable interaction with Gankyrin. This article reports for the first time that treatment of WSE decreased the cancerous properties through host cellular response modulation in gastric epithelial cells coinfected with H. pylori and EBV.Communicated by Ramaswamy H. Sarma.

Dysbiosis of Gut Microbiota from the Perspective of the Gut-Brain Axis: Role in the Provocation of Neurological Disorders.

The gut-brain axis is a bidirectional communication network connecting the gastrointestinal tract and central nervous system. The axis keeps track of gastrointestinal activities and integrates them to connect gut health to higher cognitive parts of the brain. Disruption in this connection may facilitate various neurological and gastrointestinal problems. Neurodegenerative diseases are characterized by the progressive dysfunction of specific populations of neurons, determining clinical presentation. Misfolded protein aggregates that cause cellular toxicity and that aid in the collapse of cellular proteostasis are a defining characteristic of neurodegenerative proteinopathies. These disorders are not only caused by changes in the neural compartment but also due to other factors of non-neural origin. Mounting data reveal that the majority of gastrointestinal (GI) physiologies and mechanics are governed by the central nervous system (CNS). Furthermore, the gut microbiota plays a critical role in the regulation and physiological function of the brain, although the mechanism involved has not yet been fully interpreted. One of the emerging explanations of the start and progression of many neurodegenerative illnesses is dysbiosis of the gut microbial makeup. The present understanding of the literature surrounding the relationship between intestinal dysbiosis and the emergence of certain neurological diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis, is the main emphasis of this review. The potential entry pathway of the pathogen-associated secretions and toxins into the CNS compartment has been explored in this article at the outset of neuropathology. We have also included the possible mechanism of undelaying the synergistic effect of infections, their metabolites, and other interactions based on the current understanding.

Comparative Account of Biomolecular Changes Post Epstein Barr Virus Infection of the Neuronal and Glial Cells Using Raman Microspectroscopy.

Raman microspectroscopy is a vibrational spectroscopy technique used for investigating molecular fingerprints of a wide range of liquid or solid samples. The technique can be efficiently utilized to understand the virus-mediated cellular changes and could provide valuable insights into specific biomolecular alterations. The Epstein Barr virus (EBV) has been associated with various types of cancers as well as neurodegenerative diseases. However, EBV-mediated neurological ailments are yet underexplored in terms of biomolecular changes in neuronal and glial cells (astrocytes and microglia). In continuation of our earlier exploration of EBV-influenced glial cells, we tried to decipher biomolecular changes in EBV-infected neuronal cells using Raman microspectroscopy. Additionally, we compared the consecutive biomolecular changes observed in neuronal cells with both the glial cells. We observed that EBV infection gets differentially regulated in the neuronal cells, astrocytes, and microglia. The viral entry and initiation of infection-mediated cellular modulation could start as soon as 2 h post infection but may regulate a distinct biomolecular milieu in different time intervals. Similar to the early timespan, the 24-36 h interval could also be important for EBV to manipulate neuronal as well as glial cells as depicted from elevated biomolecular activities. At these time intervals, some common biomolecules such as proline, glucose, lactic acid, nucleotides, or cholesterol were observed in the cells. However, at these time intervals, some distinct biomolecules were also observed in each cell, such as collagen, lipid, and protein stretches in the neuronal nucleus (2-4 h); tyrosine and RNA in the astrocyte nucleus (2-4 h nucleus); and fatty acids in the microglia nucleus (24-36 h). The observed biomolecular entities could ultimately play pivotal roles in the viral usurpation of cells. We also provided insights into whether these biomolecular changes can be correlated to each other and mediate virus-associated manifestations which can be linked to neurological complications. Our study aids in the understanding of EBV-mediated biomolecular changes in the various compartments of the central nervous system.