Biology subjects

Babele, P.

Publications and source records attributed to Babele, P..

4 recordsLinked to original sources

bioRxiv2024

Distance between miRNA responsive elements selectively enhances target specificity with reduced cellular toxicity by miRNA-mediated synergism

Despite the emergence of miRNAs as promising therapeutic tools in cancer management, most clinical trials have not been successful due to their cytotoxic effects. Here, we have investigated the factors regulating the effect of miRNA-mimic pairs in enhancing target gene specificity while reducing cellular toxicity. Synergistic reductions by the miRNA-mimic pairs were observed for the 3-UTRs of common target genes with miRNA-responsive elements (MREs) preferentially located at a distance of 200-800bp. Deletion of either of the miRNA seed sequences resulted in a loss of synergism. Furthermore, we performed small RNA-sequencing to identify significantly downregulated miRNAs in Oral cancer. Consequently, we transfected let-7c-5p and miR-125b-5p miRNA mimics either alone or in combination at half-dose concentrations and determined the expression levels of their common and unique target genes in oral cancer cells. Significant reductions in target gene expression were observed for genes containing MREs for both miRNA mimics within the preferential distance. Proteomic data revealed that the let-7c-5p and miR-125b-5p miRNA-mimic pairs synergistically reduced the expression of their common target genes, hexokinase 2 (HK2) and branched-chain amino acid transaminase 1 (BCAT1), in cancer cells. However, unique target genes did not exhibit any significant alterations in their protein levels. The effect of HK2 and BCAT1 downregulation was also reflected in the metabolomic profiling of cancer cells, specifically affecting glycolysis and the BCAA degradation pathways. As a result of the metabolic impairment caused by the synergistic effect of miRNA mimic pairs, oral cancer cells showed a significant reduction in proliferation, migration, and spheroid formation compared to cells treated with either single miRNA. The synergistic effect of these miRNA mimics was lost in normal keratinocytes, possibly due to low expression levels of the target oncogenes, suggesting a cancer cell-specific effect of this mechanism.

cancer biology↗

bioRxiv2024

(p)ppGpp and DksA play crucial role in reducing the efficacy of b-lactam antibiotics by modulating bacterial membrane permeability

The key signaling molecules in the bacterial stress sensing pathway, the alarmone (p)ppGpp and transcription factor DksA, help in survival during nutritional deprivation and exposure to xenobiotics by modulating cellular metabolic pathways. In Vibrio cholerae, (p)ppGpp metabolism is solely linked with the functions of three proteins: RelA, SpoT, and RelV. At threshold or elevated concentrations of (p)ppGpp, the level of cellular metabolites and proteins in the presence and absence of DksA in V. cholerae and other bacteria has not yet been comprehensively studied. We engineered the genome of V. cholerae to develop DksA null mutants in the presence and absence of (p)ppGpp biosynthetic enzymes. We observed a higher sensitivity of the (p)ppGpp0{Delta}dksA V. cholerae mutant to different -lactam antibiotics compared to the wild-type (WT) strain. Our whole-cell metabolomic and proteome analysis revealed that the cell membrane and peptidoglycan biosynthesis pathways are significantly altered in the (p)ppGpp0, {Delta}dksA, and (p)ppGpp0{Delta}dksA V. cholerae strains. Further, the mutant strains displayed enhanced inner and outer membrane permeability in comparison to the WT strains. These results directly correlate with the tolerance and survival of V. cholerae to -lactam antibiotics. These findings may help in the development of adjuvants for -lactam antibiotics by inhibiting the functions of stringent response modulators. ImportanceThe (p)ppGpp biosynthetic pathway is widely conserved in bacteria. Intracellular levels of (p)ppGpp and the transcription factor DksA play crucial roles in bacterial multiplication and viability in the presence of antibiotics and/or other xenobiotics. The present findings have shown that (p)ppGpp and DksA significantly reduces the efficacy of -lactam and other antibiotics by modulating the availability of peptidoglycan and cell membrane-associated metabolites by reducing membrane permeability. Nevertheless, the whole-cell proteome analysis of (p)ppGpp0, {Delta}dksA, and (p)ppGpp0{Delta}dksA strains identified the biosynthetic pathways and associated enzymes that are directly modulated by the stringent response effector molecules. Thus, the (p)ppGpp metabolic pathways and DksA could be a potential target for increasing the efficacy of antibiotics and developing antibiotic adjuvants.

microbiology↗

bioRxiv2022

Prophylactic treatment of Glycyrrhiza glabra mitigates COVID-19 pathology through inhibition of pro-inflammatory cytokines in the hamster model and NETosis.

Severe coronavirus disease (COVID-19) is accompanied with acute respiratory distress syndrome & pulmonary pathology, and is presented mostly with inflammatory cytokine release, dysregulated immune response, skewed neutrophil/ lymphocyte ratio, and hypercoagulable state. Though vaccinations have proved effective in reducing the COVID-19 related mortality, the limitation of use of vaccine against immunocompromised, comorbidity, and emerging variants remains a concern. In the current study we investigate for the first-time the efficacy of Glycyrrhiza glabra (GG) extract, a potent immunomodulator, against SARS-CoV-2 infection in hamsters. Prophylactic treatment with GG showed protection against loss in body weight and 35-40% decrease in lung viral load along with reduced lung pathology in the hamster model. Remarkably, GG reduced the mRNA expression of pro-inflammatory cytokines and Plasminogen activator inhibito-1 (PAI-1). In-vitro, GG acted as potent immunomodulator by reducing Th2 and Th17 differentiation and IL-4 and IL-17A cytokine production. In addition, GG also showed robust potential to suppress ROS, mtROS and NETs generation in a concentration dependent manner in both human polymorphonuclear neutrophils (PMNs) and murine bone marrow derived neutrophils (BMDNs). Taken together, we provide evidence for the protective efficacy of GG against COVID-19 and its putative mechanistic insight, which might be developed as a future immunomodulatory approach against various pathologies with high cytokine production, aberrant neutrophil activation including coronavirus infection.

immunology↗

bioRxiv2021

Accelerating Strain Engineering using Desorption Electrospray Ionization-Imaging Mass Spectrometry and Untargeted Molecular Analysis of Intact Microbial Colonies.

Progress in the fields of genomic and biologic sciences has yielded microbial bioprocesses for the advanced production of chemicals. While biomanufacturing has the potential to address global demands for renewable fuels and chemicals, engineering microbial cell factories that can compete with synthetic chemical processes remains a challenge. Optimizing strains for enhanced chemical production is no longer limited by reading and writing DNA, rather it is impeded by the lack of high-throughput platforms for characterizing the metabolic phenotypes resulting from specific gene editing events. To address this issue, we have developed a desorption electrospray ionization- imaging mass spectrometry (DESI-IMS) screening assay that is conducive to both multiplexed sampling and untargeted analyses. This technology bridges the gap between genomic and metabolomic timescales by simultaneously characterizing the chemical output of various engineered Escherichia coli strains rapidly and directly under ambient conditions. The developed method was used to phenotype four E. coli strains on the basis of measured metabolomes, which were validated via PCR genotyping. Untargeted DESI-IMS phenotyping suggests multiple strategies for future engineering which include: (i) relative amounts of specific biosynthetic products, (ii) identification of secondary products, and (iii) the metabolome of engineered organisms. In sum, we present a workflow to accelerate strain engineering by providing rapid, untargeted, and multiplexed analyses of microbial metabolic phenotypes.

bioengineering↗