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Dash, R.

Publications and source records attributed to Dash, R..

At least 19 recordsLinked to original sources

A Deep Learning Framework for Biomarker Segmentation and Classification in Traumatic Brain Injury

Traumatic brain injury (TBI) triggers widespread biomarker activation, including astrocytic markers such as glial fibrillary acidic protein (GFAP) and microglia markers such as ionized calcium-binding adapter molecule 1 (IBA1). Quantifying and analyzing these biomarkers are critical for understanding injury impact; however, current methods are labor-intensive and time-consuming. In this study, we propose an automated deep learning framework for dual-biomarker segmentation and TBI classification using GFAP and IBA1 immunofluorescent images. Four U-Net variants: Baseline U-Net, U-Net++, MANet, and LinkNet were trained for segmentation. Three classification models, ResNet50, Swin_T, and MaxViT, were trained to distinguish TBI from control images under single- and dual-biomarker conditions. The baseline U-Net achieved the highest segmentation Dice score for GFAP (0.9259), while the U-Net++ achieved the highest Dice score for IBA1 (0.9676). Trained segmentation models demonstrated significantly better performance compared to QuPath alternatives. While GFAP alone supported high classification accuracy, IBA1 alone was less effective. Multimodal fusion of GFAP and IBA1 significantly improved classification performance across all models, with Swin_T achieving the highest overall accuracy (0.9489), and ResNet50 achieving the highest F1-score (0.9499). These findings demonstrate that integrating complementary biomarkers enhances automated TBI classification, and deep learning offers a robust alternative to manual analysis for immunofluorescent brain injury imaging. This framework is scalable to additional biomarkers and injury models, offering a reproducible approach to accelerate biomarker research.

neuroscience↗

Molecular Determinants Governing the Antitubercular Activity of Griselimycin

The emergence of drug-resistant strains of Mycobacterium tuberculosis makes anti-tubercular drug development a critical priority. Griselimycin is a cyclic peptide that targets the essential DNA sliding clamp of M. tuberculosis. While griselimycin is a promising antimycobacterial compound, its poorly understood structure-activity relationship has stalled derivatization. To investigate the contribution of each amino acid towards its activity, we assessed the antibiotic activity of an alanine scan library in M. tuberculosis. Incorporation of an N-terminal fluorophore enabled visualization of griselimycin accumulation inside of mycobacteria-infected macrophage cells. Derivatives containing altered cyclization chemistries, unnatural amino acids, expanded proline side chains, and alkyne handles were assessed, with a final design combining the most potent edits showing increased antibiotic activity. These findings present the comprehensive structure-activity investigation of griselimycin and can be used to rationally design future analogues.

pharmacology and toxicology↗

Data-Driven Mechanistic Computational Modeling of Human Cell Cycle Phases for Defining Inhibitor Combinations in Silico

The human cell cycle is a highly regulated process that integrates multiple signaling pathways and checkpoints to ensure faithful genome duplication and cell division. Disruptions in these regulatory networks contribute to a wide range of diseases. Here, we present a novel, updateable computational model of the full human cell cycle that shows sustained oscillations over time and reproduces experimental perturbations. We used a hybrid framework combining mass action and Michaelis-Menten kinetics, incorporating the synthesis, degradation, and regulation of key cell cycle proteins and protein complexes. It consists of 63 distinct biochemical species, interacting through 41 major reactions, and functioning through 63 ODEs. The model is built upon a modular framework, structured around the core regulatory networks of the G1, S, G2, and M phases. Due to its complexity, we determined parameter sets that met strict criteria, namely event timing, comparable concentrations, and continuous cycling. We validated the models behavior by reproducing canonical checkpoint responses, including mitogen dependence and the DNA damage response, both of which produced reversible and robust cell cycle arrests. Importantly, the model was trained and calibrated using in vitro data from human U251-MG glioma cells expressing the FastFUCCI cell cycle reporter. We quantitatively aligned the simulated and experimentally determined phase durations and cell doubling times. Next, we experimentally tested and refined model parameters by using abemaciclib-mediated inhibition of CDK4 and volasertib-mediated inhibition of PLK1. In vitro and in silico data show dose-dependent G1 arrest by abemaciclib and dose-dependent mitotic arrest by volasertib. Finally, we demonstrated that the model predicts changes in cell proliferation over a wide range of drug concentrations and combinations. Overall, our work establishes a robust, data-driven computational model for systems-level analysis of the human cell cycle and its disruption by therapeutic perturbations. AUTHOR SUMMARYKnowledge of the protein-protein interaction networks governing the cell cycle is ever-expanding, yet this information is often fragmented across studies focusing on disconnected subsets of the cycle. For decades, researchers have investigated the underlying mechanisms of cell division, but an integrated, quantitative understanding of the entire process remains elusive. This gap is a major hurdle for predicting how targeted therapies affect cell proliferation, especially when used in combination. Our goal is to develop an in silico simulation of the complete human cell cycle by integrating the key mechanistic relationships across all four phases into a single computational model with enough resolution to approximate outcomes upon perturbation. In achieving this, we have developed a novel, comprehensive computational model that provides an integrated quantitative understanding of how cancer drugs alter the human cell cycle. We have rigorously trained, calibrated, and validated the model by suitably estimating its parameter values to produce accurate cell cycle phase timing, using high-resolution, live-cell imaging data and other cardinal features of the cell cycle in a U251-MG glioblastoma line. This work provides an accessible tool for exploring how normal cell cycle control is disrupted in disease, generating new hypotheses, and identifying potential points of therapeutic intervention.

cancer biology↗

Split-luciferin Assay for Real-time Measurement of Cytosolic Drug Accumulation in Live Mycobacteria

Tuberculosis causes over one million deaths annually and remains the leading cause of death from a single infectious agent. The emergence of multidrug-resistant Mycobacterium tuberculosis strains highlights the urgent need for new antibiotics, a pursuit hindered by the bacteriums complex cell envelope. As most anti-tuberculosis agents act on intracellular targets, assessing cytosolic drug accumulation is critical. Conventional approaches generally quantify whole-cell association without resolving subcellular localization. Moreover, no current method permits real-time monitoring of drug accumulation in live mycobacterial cells. Here, we present a split-luciferin-based assay to quantify molecular accumulation in mycobacteria. Using this approach, we quantified the cytosolic accumulation of diverse small-molecule antibiotics and polyarginine peptides conjugated via a disulfide-linked D-cysteine tag. We also show the localization of a polyarginine peptide inside of mycobacteria in infected macrophage cells, demonstrating that these peptides can cross multiple accumulation barriers. Our findings establish the first assay for real-time quantification of cytosolic molecular accumulation in live mycobacteria, addressing a longstanding methodological gap and enabling mechanistic insights into intracellular drug uptake.

microbiology↗

Profiling Cytosolic Drug Delivery in Mammalian Cells: A Generalizable Assay for Intracellular Accumulation

The ability of biologically active molecules to access intracellular targets remains a critical barrier in drug development. While assays for measuring cellular uptake exist, they often fail to distinguish between membrane-associated or endosomal trapped compounds and those that successfully reach the cytosol. Here, we present the Chloroalkane HaloTag Azide-based Membrane Penetration (CHAMP) Assay, a novel high-throughput method that employs a minimally disruptive azide tag to report the cytosolic accumulation of diverse molecules in mammalian cells. The CHAMP assay utilizes HaloTag-expressing cells and strain-promoted azide-alkyne cycloaddition (SPAAC) chemistry to quantify the presence of azide-tagged test compounds in the cytosol. We demonstrate the versatility of this approach by evaluating the accumulation profiles of small molecules, peptides, and proteins, revealing how structural variations and stereochemical differences influence cytosolic penetration. Our findings with cell-penetrating peptides confirm established structure-activity relationships, with longer polyarginine sequences showing enhanced accumulation. Additionally, we observed that C-terminal amidation and D-amino acid substitutions significantly impact cellular penetration. When applied to supercharged proteins and antibiotics, CHAMP successfully discriminates between compounds with varying accumulation capabilities. This method provides a robust platform for screening cytosolic accumulation while minimizing the confounding effects of large tags on molecular permeability, potentially accelerating the development of therapeutics targeting intracellular pathways.

biochemistry↗

Unraveling the distinct motion bias of TrkA-NGF complex in NGFR100W-driven HSAN V disease

Nerve growth factor (NGF), which binds to tropomyosin-related kinase A (TrkA) receptor, plays essential roles in neuronal survival and function and is also a potent mediator of pain sensation. Mutations in NGF, particularly NGFR100W, cause hereditary sensory autonomic neuropathy V (HSAN V), which is characterized by insensitivity to pain but without impairment of neurotrophin function. Even though several studies reported the mechanism of growing HSAN V disease, the dynamic mechanisms that dictate its functional specificity remain unclear. In this study, we performed a microsecond scale molecular dynamics (MD) simulation to elucidate the changes in the structural dynamics of NGF by NGFR100W at an atomic level to dissect the distinct motion bias for specific TrkA functions. We found that the NGFR100W reduced NGF dimerization while its binding to the TrkA remained unchanged. NGFR100W enhanced the magnitude of bond formation in the different regions from TrkA, which induced different correlated and dynamic motions associated with impaired nociceptive signaling. The dynamics scenario from this study, shedding light on the deleterious role of NGFR100W, provides new structural insights into the function-oriented dynamics motion of the TrkA-NGF complex, offering potential avenues for designing new therapeutics.

neuroscience↗

Systematic Determination of the Impact of Structural Edits on Accumulation into Mycobacteria

Understanding the factors that influence the accumulation of molecules beyond the mycomembrane of Mycobacterium tuberculosis (Mtb) - the main barrier to accumulation - is essential for developing effective antimycobacterial agents. In this study, we investigated two design principles commonly observed in natural products and mammalian cell-permeable peptides: backbone N-alkylation and macrocyclization. To assess how these structural edits impact molecule accumulation beyond the mycomembrane, we utilized our recently developed Peptidoglycan Accessibility Click-Mediated Assessment (PAC-MAN) assay for live-cell analysis. Our findings provide the first empirical evidence that peptide macrocyclization generally enhances accumulation in mycobacteria, while N-alkylation influences accumulation in a context-dependent manner. We examined these design principles in the context of two peptide antibiotics, tridecaptin A1 and griselimycin, which revealed the roles of N-alkylation and macrocyclization in improving both accumulation and antimicrobial activity against mycobacteria in specific contexts. Together, we present a working model for strategic structural modifications aimed at enhancing the accumulation of molecules past the mycomembrane. More broadly, our results also challenge the prevailing belief in the field that large and hydrophilic molecules, such as peptides, cannot readily traverse the mycomembrane.

microbiology↗

Clostridium novyi type B causes fatal hemorrhagic disease in wild Asian elephants

The population of Asian elephants, an endangered species, is decreasing significantly due to anthropogenic interference in India. Research on Asian elephant disease is largely confined to observations reported from captive populations. The present study explored 11 disease investigation cases whose clinicopathological changes were similar to those of fatal hemorrhagic disease caused by Bacillus anthracis. We used molecular diagnostic approaches such as PCR (polymerase chain reaction), quantitative PCR, 16S metagenomics analysis and whole-metagenome sequencing for identification of the etiological agent responsible for these wild elephant mortalities. 16S metagenomics analysis revealed the presence of Clostridium hemolyticum as the dominant bacteria in all the mortality events. In contrast, flagellin gene-specific identification of all the samples and whole metagenomics analysis of blood samples collected from the ear pinna of a freshly deceased elephant revealed Clostridium novyi type B as the sole pathogenic agent responsible for the death of elephants. This study provides the first evidence of the involvement of Clostridium novyi type B in the death of wild elephants with similar clinical manifestations to anthrax. The current study also provides ample evidence of the need to explore investigations of emerging diseases of wild elephants to conserve these large mammals.

microbiology↗

Elucidating conformational alteration of human islet amyloid polypeptide by nonsynonymous substitution

Islet amyloid polypeptide (IAPP) is a peptide hormone that serves multiple essential functions, including metabolism and regulating gastric emptying and satiation through amylin receptors. However, mutations in the IAPP, notably in the amyloidogenic segment (20-29 amino acid residues), cause its aggregation and amyloid formation, which leads to {beta}-cell toxicity and death in type 2 diabetes mellitus (T2DM) and protein misfolding disorders (PMDs). The current work aims to elucidate the non-synonymous variants in the IAPP, which may adversely affect its function and rise to T2DM and PMDs. We harnessed in silico non-synonymous single-nucleotide polymorphisms (nsSNPs) assessment and molecular dynamics (MD) simulation to discover the potential deleterious mutants that cause T2DM and PMDs. Firstly, we executed nsSNPs prediction in IAPP using the NCBI dbSNP server, and then, all the predicted nsSNPs were assessed by a total of 26 in silico tools to find out which possessed the most deleterious effect in IAPP. Finally, MD simulation was carried out utilizing the most deleterious nsSNPs to check which significantly alters the conformational dynamics of IAPP. We found a total of 62 nsSNPs, among which the top 4 deleterious nsSNPs (T37P, L45P, G66R, and T69I) were selected based on the deleteriousness predictions by in silico tools and their location in the mature IAPP sequence (34-70 amino acid residues). MD simulations further confirm that three variants (T37P, L45P, and G66R) significantly alter the conformational dynamics of IAPP, suggesting a potential starting point for future research to elucidate the roles of these variants in IAPP aggregation and amyloid formation and their associations with T2DM and PMDs.

biophysics↗

Proteostasis Associated Variants in HSPB5 Destabilize the αB-crystallin Domain

HSPB5 (B-crystallin) is an ATP-independent, stress-inducible chaperone protein that improves protein misfolding and degradation in proteotoxicity-related diseases, including several myopathies, neurodegenerative diseases, and cancers. Although single nucleotide polymorphism (SNP) reduces the overall activity of HSPB5, its dynamic behaviour remains unknown. To get molecular insights into the deleterious, pathogenic, and proteotoxicity-related mutations, this study investigates the potential deleterious SNPs associated with HSPB5. Notably, eleven computational tools identified D109H, R120G, and D140N as the most deleterious SNPs from a total of 313 missense SNPs. Interestingly, these three mutations are present in the core B-crystallin (B-c) domain. A molecular dynamics simulation for 500 ns was conducted to reveal these variants mechanistic insights. The mutant variants showed higher flexibility and significant conformational changes than the wild, which might be noteworthy to reduce these variants chaperoning activity. Also, this conformational change elucidated the loss of function mutations, which could alter these variants oligomeric properties. This study will help our understanding of the role and molecular mechanism of HSPB5 mutations in proteotoxicity vulnerable diseases.

bioinformatics↗

NEK9 ablation rewires docetaxel resistance through induction of ERK-mediated cancer cell pyroptosis

Docetaxel alone or in combination with other drugs is the most common chemotherapy regimen for several neoplasms including advanced OSCC. Unfortunately, chemoresistance leads to relapse and continued tumor growth. It is therefore important to explore the causative factors for docetaxel resistance. In this study, we performed a CRISPR-based kinome screening that identified Never In Mitosis Gene-A Related Kinase-9 (NEK9) as a major player of docetaxel resistance in OSCC, prostate, and pancreatic cancer lines. NEK9 expression was upregulated in tumor samples of chemotherapy non-responders compared to responder OSCC patients. Our validation data suggests selectively knocking out NEK9 sensitizes cancer cells to docetaxel. Mechanistically, we found that ablation of NEK9 induces DNA damage, activating ERK(p-T202/Y204) that leads to Gasdermin-E mediated Cancer Cell pyroptosis. The in-vitro kinase activity assay identified fostamatinib as a potent inhibitor of NEK9. The xenograft data suggest that fostamatinib restores docetaxel sensitivity and facilitates a significant reduction of tumor burden. Overall, our data suggests a novel combination of fostamatinib and docetaxel needs further clinical investigation in advanced OSCC.

cancer biology↗

Bioluminescence-Based Determination of Cytosolic Accumulation of Antibiotics in Escherichia coli

Antibiotic resistance is an alarming public health concern that affects millions of individuals across the globe each year. A major challenge in the development of effective antibiotics lies in their limited ability to permeate into cells, noting that numerous susceptible antibiotic targets reside within the bacterial cytosol. Consequently, improving cellular permeability is often a key consideration during antibiotic development, underscoring the need for reliable methods to assess the permeability of molecules across cellular membranes. Currently, methods used to measure permeability often fail to discriminate between arrival within the cytoplasm and the overall association of molecules with the cell. Additionally, these techniques typically possess throughput limitations. In this work, we describe a luciferase-based assay designed for assessing the permeability of molecules into the cytosolic compartment of Gram-negative bacteria. Our findings demonstrate a robust system that can elucidate the kinetics of intracellular antibiotics accumulation in live bacterial cells in real time.

microbiology↗

Development of a Plasmodium vivax biobank for functional ex vivo assays

BackgroundPlasmodium vivax is the second most prevalent cause of malaria yet remains challenging to study due to the lack of a continuous in vitro culture system, highlighting the need to establish a biobank of clinical isolates with multiple freezes per sample for use in functional assays. Different methods for cryopreserving parasite isolates were compared and subsequently the most promising one was validated. Enrichment of early- and late-stage parasites and parasite maturation were quantified to facilitate assay planning. MethodsIn order to compare cryopreservation protocols, nine clinical P. vivax isolates were frozen with four glycerolyte-based mixtures. Parasite recovery post thaw, post KCl-Percoll enrichment and in short-term in vitro culture was measured via slide microscopy. Enrichment of late-stage parasites by magnetic activated cell sorting (MACS) was measured. Short and long-term storage of parasites at either -80{degrees}C or liquid nitrogen were also compared. ResultsOf the four cryopreservation mixtures, one mixture (glycerolyte:serum:RBC at a 2.5:1.5:1 ratio) resulted in improved parasite recovery and statistically significant (P<0.05) enhancement in parasite survival in short-term in vitro culture. A parasite biobank was subsequently generated using this protocol resulting in a collection with 106 clinical isolates, each with 8 vials. The quality of the biobank was validated by measuring several factors from 47 thaws: the average reduction in parasitemia post-thaw (25.3%); the average fold enrichment post KCl-Percoll (6.65-fold); and the average percent recovery of parasites (22.0%, measured from 30 isolates). During short-term in vitro culture, robust maturation of ring stage parasites to later stages (>20% trophozoites, schizonts and gametocytes) was observed in 60.0% of isolates by 48 hours. Enrichment of mature parasite stages via MACS showed good reproducibility, with an average 30.0% post-MACS parasitemia and an average 5.30 x 105 parasites/vial. Finally, the effect of storage temperature was tested, and no large impacts from short-term (7 day) or long term (7 - 10 year) storage at -80{degrees}C on parasite recovery, enrichment or viability was observed. ConclusionsHere, an optimized freezing method for P. vivax clinical isolates is demonstrated as a template for the generation and validation of a parasite biobank for use in functional assays.

microbiology↗

CMTM6 mediates cisplatin resistance in OSCC by regulating AKT/c-MYC driven ribosome biogenesis

CMTM6, a type 3 transmembrane protein, is known to stabilize the expression of programmed cell death ligand 1 (PD-L1) and hence facilitates the immune evasion of tumor cells. Recently, we demonstrated that CMTM6 is a major driver of cisplatin resistance in oral squamous cell carcinomas (OSCC). However, the detailed mechanism how CMTM6 rewires cisplatin resistance in OSCC is yet to be explored. RNA sequencing analysis of cisplatin resistant OSCC lines stably expressing NtShRNA and CMTM6 ShRNA revealed that CMTM6 might be a potential regulator of ribosome biogenesis network. Knocking down CMTM6 significantly inhibited transcription of 47S precursor rRNA and hindered the nucleolar structure, indicating reduced ribosome biogenesis. When CMTM6 was ectopically over expressed in CMTM6KD cells, almost all ribosomal machinery components were rescued. Mechanistically, CMTM6 induced the expression of C-Myc, which promotes RNA polymerase I mediated rDNA transcription. In addition to this, CMTM6 also found to regulate the AKT-mTORC1-dependent ribosome biogenesis and protein synthesis in cisplatin resistant lines. The nude mice and zebrafish xenograft experiments indicate that blocking ribosome synthesis either by genetic inhibitor (CMTM6KD) or by pharmacological inhibitor (CX-5461), significantly restores cisplatin medicated cell death in chemoresistant OSCC. Overall, our study suggests that CMTM6 is a major regulator of ribosome biogenesis network and targeting ribosome biogenesis network is a viable target to overcome chemoresistance in OSCC. The novel combination of CX-5461 and cisplatin deserves further clinical investigation in advanced OSCC.

cancer biology↗

Template-based design of peptides to inhibit SARS-CoV-2 RNA-dependent RNA polymerase complexation.

The RNA-dependent RNA polymerase (RdRp) complex of SARS-CoV-2 lies at the core of its replication and transcription processes. The interfaces between the subunits of the RdRp complex are highly conserved, facilitating the design of inhibitors with high affinity for the interaction hotspots of the complex. Here, we report development and application of a structural bioinformatics protocol to design peptides that can inhibit RdRp complex formation by targeting the interface of its core subunit nonstructural protein (nsp) 12 with accesory factor nsp7. We adopt a top-down approach for protein design by using interaction hotspots of the nsp7-nsp12 complex obtained from a long molecular dynamics trajectory as template. A large library of peptide sequences constructed from multiple hotspot motifs of nsp12 is screened in silico to determine peptide sequences with highest shape and interaction complementarity for the nsp7-nsp12 interface. Two lead designed peptide are extensively characterized using orthogonal bioanalytical methods to determine their suitability for inhibition of RdRp complexation and anti-viral activity. Their binding affinity to nsp7 (target), as determined from surface plasmon resonance (SPR) assay, is found to be comparable to that of the nsp7-nsp12 complex. Further, one of the designed peptides gives 46 % inhibition of nsp7-nsp12 complex at 10:1 peptide:nsp7 molar concentration (from ELISA assay). Further optimization of cell penetrability and target affinity of these designed peptides is expected to provide lead candidates with high anti-viral activity against SARS-CoV-2.

bioinformatics↗

Isolation and Characterization of SARS-CoV-2 strains circulating in Eastern India.

Emergence of SARS-CoV-2 as a serious pandemic has altered the global socioeconomic dynamics. The wide prevalence, high death counts and rapid emergence of new variants urge for establishment of research infrastructure to facilitate rapid development of efficient therapeutic modalities and preventive measures. In agreement with this, five SARS-CoV2 strains (ILS01, ILS02, ILS03, ILS15 and ILS24) of four different clades (19A, 19B, 20A and 20B) were isolated from patient swab samples collected during the 1st COVID-19 wave in Odisha, India. The viral isolates were adapted to in-vitro cultures and further characterized to identify strain specific variations in viral growth characteristics. All the five isolates showed substantial amount of virus induced CPE however ILS03 belonging to 20A clade displayed highest level of CPE. Time kinetics experiment revealed spike protein expression was evident after 16th hours post infection in all five isolates. ILS03 induced around 90% of cytotoxicity. Further, the susceptibility of various cell lines (human hepatoma cell line (Huh-7), CaCo2 cell line, HEK-293T cells, Vero, Vero-E6, BHK-21, THP-1 cell line and RAW 264.7 cells) were assessed. Surprisingly, it was found that the human monocyte cells THP-1 and murine macrophage cell line RAW 264.7 were permissive to all the SARS-CoV-2 isolates. The neutralization susceptibility of viral isolates to vaccine-induced antibodies was determined using sera from individuals vaccinated in the Government run vaccine drive in India. The micro-neutralization assay suggested that both Covaxin and Covishield vaccines were equally effective (100% neutralization) against all of the isolates. The whole genome sequencing of culture adapted viral isolates and viral genome from patient oropharyngeal swab sample suggested that repetitive passaging of SARS-CoV2 virus in Vero-E6 cells did not lead to emergence of many mutations during the adaptation in cell culture. Phylogenetic analyses revealed that the five isolates clustered to respective clades. The major goal was to isolate and adapt SARS-CoV-2 viruses in in-vitro cell culture with minimal modification to facilitate research activities involved in understanding the molecular virology, host-virus interactions, application of these strains for drug discovery and animal challenge models development which eventually will contribute towards the development of effective and reliable therapeutics.

microbiology↗

MINK1 modulates 5FU resistance in OSCC through AKT/MDM2 mediated regulation of p53

Cisplatin, 5FU and docetaxel (TPF) are the most common chemotherapy regimen used for advanced OSCC. However, many cancer patients experience relapse, continued tumor growth, and spread due to drug resistance, which leads to treatment failure and metastatic disease. Here, using a CRISPR/Cas9 based kinome knockout screening, Misshapen-like kinase 1 (MINK1) is identified as an important mediator of 5FU resistance in OSCC. Analysis of clinical samples demonstrated significantly higher MINK1 expression in the tumor tissues of chemotherapy non-responder as compared to chemotherapy responders. The nude mice and zebrafish xenograft experiments indicate that knocking out MINK1 restores 5FU mediated cell death in chemoresistant OSCC. An antibody based phosphorylation array screen revealed MINK1 as a negative regulator of p53. Mechanistically, MINK1 modulates AKT phosphorylation at Ser473, which enables p-MDM2 (Ser 166) mediated degradation of p53. We also identified lestaurtinib as a potent inhibitor of MINK1 kinase activity. The patient derived TPF resistant cell based xenograft data suggest that lestaurtinib restores 5FU sensitivity and facilitates a significant reduction of tumor burden. Overall, our study suggests that MINK1 is a major driver of 5FU resistance in OSCC. The novel combination of MINK1 inhibitor lestaurtinib and 5FU needs further clinical investigation in advanced OSCC.

cancer biology↗

Quantitative proteomics of hamster lung tissues infected with SARS-CoV-2 reveal host-factors having implication in the disease pathogenesis and severity

Syrian golden hamsters (Mesocricetus auratus) infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manifests lung pathology that resembles human COVID-19 patients. In this study, efforts were made to check the infectivity of a local SARS-CoV-2 isolate in hamster model and evaluate the differential expression of lung proteins during acute infection and convalescence. The findings of this study confirm the infectivity of this isolate in vivo. Analysis of clinical parameters and tissue samples shows a similar type of pathophysiological manifestation of SARS-CoV-2 infection as reported earlier in COVID-19 patients and hamsters infected with other isolates. The lung-associated pathological changes were very prominent on the 4th day post-infection (dpi), mostly resolved by 14dpi. Here, we carried out quantitative proteomic analysis of the lung tissues from SARS-CoV-2-infected hamsters at day 4 and day 14 post infection. This resulted in the identification of 1,585 differentially expressed proteins of which 68 proteins were significantly altered among both the infected groups. Pathway analysis revealed complement and coagulation cascade, platelet activation, ferroptosis and focal adhesion as the top enriched pathways. In addition, we also identified altered expression of two pulmonary surfactant-associated proteins (Sftpd and Sftpb), known for their protective role in lung function. Together, these findings will aid in the identification of candidate biomarkers and understanding the mechanism(s) involved in SARS-CoV-2 pathogenesis. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=143 HEIGHT=200 SRC="FIGDIR/small/434371v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1930556org.highwire.dtl.DTLVardef@14376d6org.highwire.dtl.DTLVardef@2f064eorg.highwire.dtl.DTLVardef@1472572_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗