Helicobacter pylori isolated from gastric juice have higher pathogenic potential than biopsy isolates

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.

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.

A Prototype of Graphene E-Nose for Exhaled Breath Detection and Label-Free Diagnosis of Helicobacter Pylori Infection

Helicobacter pylori (HP), a common microanaerobic bacteria that lives in the human mouth and stomach, is reported to infect ≈50% of the global population. The current diagnostic methods for HP are either invasive, time-consuming, or harmful. Therefore, a noninvasive and label-free HP diagnostic method needs to be developed urgently. Herein, reduced graphene oxide (rGO) is composited with different metal-based materials to construct a graphene-based electronic nose (e-nose), which exhibits excellent sensitivity and cross-reactive response to several gases in exhaled breath (EB). Principal component analysis (PCA) shows that four typical types of gases in EB can be well discriminated. Additionally, the potential of the e-nose in label-free detection of HP infection is demonstrated through the measurement and analysis of EB samples. Furthermore, a prototype of an e-nose device is designed and constructed for automatic EB detection and HP diagnosis. The accuracy of the prototype machine integrated with the graphene-based e-nose can reach 92% and 91% in the training and validation sets, respectively. These results demonstrate that the highly sensitive graphene-based e-nose has great potential for the label-free diagnosis of HP and may become a novel tool for non-invasive disease screening and diagnosis.

Design and synthesis of a nucleobase functionalized peptide hydrogel: in vitro assessment of anti-inflammatory and wound healing effects

Over the past several years, a significant increase in the expanding field of biomaterial sciences has been observed due to the development of biocompatible materials based on peptide derivatives that have intrinsic therapeutic potential. In this report, we synthesized nucleobase functionalized peptide derivatives (NPs). Hydrogelation in the synthesized NPs was induced by increasing their hydrophobicity with an aromatic moiety. The aggregation behavior of the NPs was analyzed by performing molecular dynamics simulations and DOSY NMR experiments. We performed circular dichroism (CD), thioflavin-T binding and PXRD to characterize the supramolecular aggregation in the NP1 hydrogel. The mechanical strength of the NP1 hydrogel was tested by performing rheological experiments. TEM and SEM experiments were performed to investigate the morphology of the NP1 hydrogel. The biocompatibility of the newly synthesized NP1 hydrogel was investigated using McCoy and A549 cell lines. The hemolytic activity of the NP1 hydrogel was examined in human blood cells. The stability of the newly formed NP1 hydrogel was examined using proteinase K and α-chymotrypsin. The NP1 hydrogel was used for in vitro wound healing. Western blotting, qRT-PCR and DCFDA assay were performed to determine the anti-inflammatory activity of the NP1 hydrogel. The synthesized NP1 hydrogel also exhibits antibacterial efficacy.

Influence of chlorpyrifos and endosulfan and their metabolites on the virulence of Helicobacter pylori

Organochlorine (OC) and organophosphorus (OP) pesticides such as chlorpyrifos (CPF) and endosulfan (ES) have been associated with a plethora of adverse health effects. Helicobacter pylori (H. pylori) infection can lead to gastrointestinal diseases by regulating several cellular processes. Thus, the current study focuses on the effect of the co-exposure to pesticides and H. pylori on gastric epithelial cells. We have used the in-silico approach to determine the interactive potential of pesticides and their metabolites with H. pylori-associated proteins. Further, various in-vitro methods depict the potential of ES in enhancing the virulence of H. pylori. Our results showed that ES along with H. pylori affects the mitochondrial dynamics, increases the transcript expression of mitochondrial fission genes, and lowers the mitochondrial membrane potential and biomass. They also promote inflammation and lower oxidative stress as predicted by ROS levels. Furthermore, co-exposure induces the multi-nucleated cells in gastric epithelial cells. In addition, ES along with H. pylori infection follows the extrinsic pathway for apoptotic signaling. H. pylori leads to the NF-κB activation which in turn advances the β-catenin expression. The expression was further enhanced in the co-exposure condition and even more prominent in co-exposure with ES-conditioned media. Thus, our study demonstrated that pesticide and their metabolites enhance the pathogenicity of H. pylori infection.

SARS-CoV-2 envelope protein induces necroptosis and mediates inflammatory response in lung and colon cells through receptor interacting protein kinase 1

SARS-CoV-2 Envelope protein (E) is one of the crucial components in virus assembly and pathogenesis. The current study investigated its role in the SARS-CoV-2-mediated cell death and inflammation in lung and gastrointestinal epithelium and its effect on the gastrointestinal-lung axis. We observed that transfection of E protein increases the lysosomal pH and induces inflammation in the cell. The study utilizing Ethidium bromide/Acridine orange and Hoechst/Propidium iodide staining demonstrated necrotic cell death in E protein transfected cells. Our study revealed the role of the necroptotic marker RIPK1 in cell death. Additionally, inhibition of RIPK1 by its specific inhibitor Nec-1s exhibits recovery from cell death and inflammation manifested by reduced phosphorylation of NFκB. The E-transfected cells' conditioned media induced inflammation with differential expression of inflammatory markers compared to direct transfection in the gastrointestinal-lung axis. In conclusion, SARS-CoV-2 E mediates inflammation and necroptosis through RIPK1, and the E-expressing cells' secretion can modulate the gastrointestinal-lung axis. Based on the data of the present study, we believe that during severe COVID-19, necroptosis is an alternate mechanism of cell death besides ferroptosis, especially when the disease is not associated with drastic increase in serum ferritin.

Computational insights into VacA toxin inhibition: harnessing FDA-approved antibiotics against Helicobacter pylori

Cancer is a condition in which a few of the body's cells grow beyond its control and spread to other outward regions. Globally, gastric cancer (GC) is third most common cause of cancer-related mortality and the fourth most common kind of cancer. Persistent infection of VacA-positive Helicobacter pylori (H. pylori) modulates cellular physiology and leads to GC. About ∼70% of H. pylori are positive for vacuolating cytotoxin-A (VacA), and it infects ∼80-90% of world populations. Herein, for first time, we repurposed FDA-approved gram-negative antibiotics, which are feasible alternatives to existing regimens and may be used in combinatorial treatment against VacA-positive H. pylori. Out of 110 FDA-approved antibiotics, we retrieved 92 structures, which were screened against the VacA protein. Moreover, we determined that the top eight hit antibiotics viz; cefpiramide, cefiderocol, eravacycline, doxycycline, ceftriaxone, enoxacin, tedizolid, and cefamandole show binding free energies of -9.1, -8.9, -8.1, -8.0, -7.9, -7.8, -7.8 and -7.8 Kcal/mol, respectively, with VacA protein. Finally, we performed 100 ns duplicate MD simulations on the top eight selected antibiotics showing strong VacA binding. Subsequently, five antibiotics, including cefiderocol, cefpiramide, doxycycline, enoxacin, and tedizolid show stable ligand protein distance and good binding affinity revealed by the MM-PBSA scheme. Among the five antibiotics cefiderocol act as the most potent inhibitor (-28.33 kcal/mol). Furthermore, we also identified the hotspot residue like Asn-506, Tyr-529, and Phe-483 which control the interaction. Concisely, we identified antibiotics that can be repurposed against VacA of H. pylori and explored their molecular mechanism of interaction with VacA.Communicated by Ramaswamy H. Sarma.