ABSTRACT: UPLC-ESI-pos-HRMS/MS analysis of incubation extracts of Vibrio furnissii. Metabolic analysis for dereplication of secondary microbial metabolites.
Project description:We established a human pluripotent stem cell (hPSC)-derived pancreatic progenitor organoid (PO) culture that provides the cellular plasticity for PDAC modeling and supports robust gene editing. Through the combinatorial expression of oncogenic KRAS and deletion of multiple tumor suppressor genes (TSGs),we successfully recapitulated the transcriptional hallmarks of initial malignant transformation and progression of PDAC in POs in vitro. Moreover, these POs exhibited distinct histopathology from preneoplastic pancreatic intraepithelial neoplasia (PanIN) and moderately differentiated to poorly differentiated PDAC upon orthotopic transplantation. Further chromatin accessibility profiling unveiled 1) a progressive loss of pancreatic lineage program during disease development, accompanied by repression of TET1, 5hmc marking and hypermethylation of essential pancreatic lineage transcription factors and 2) an emergence of trans-lineage/malignant feature, associated with the opening of AP-1 motif enriched chromatin regions. Gene perturbation screening identified FOSL2, FOS, and JUNB as pro-malignancy AP-1 factors during malignant transformation of POs. Notably, inhibition of ERK, a regulator of AP-1, not only reversed AP-1 levels and malignant feature in transformed POs, but also derepressed TET1 and its associated chromatin regions. Thus, our de novo PDAC POs faithfully model the disease development and reveal distinct but concerted mechanisms that drive the cellular plasticity in PDAC. The comprehensive validation of this model against clinical datasets approves its potential for discovery of therapeutic targets and biomarkers for preventive screening in the future.
Project description:we report the effect of Ramoplanin on the transcription profile of RPE cells in comparison to DMSO (Vehicle) or MFGE8+GAS6 treated cells in the presence and absence of POS
Project description:We established a human pluripotent stem cell (hPSC)-derived pancreatic progenitor organoid (PO) culture that provides the cellular plasticity for PDAC modeling and supports robust gene editing. Through the combinatorial expression of oncogenic KRAS and deletion of multiple tumor suppressor genes (TSGs),we successfully recapitulated the transcriptional hallmarks of initial malignant transformation and progression of PDAC in POs in vitro. Moreover, these POs exhibited distinct histopathology from preneoplastic pancreatic intraepithelial neoplasia (PanIN) and moderately differentiated to poorly differentiated PDAC upon orthotopic transplantation. Further chromatin accessibility profiling unveiled 1) a progressive loss of pancreatic lineage program during disease development, accompanied by repression of TET1, 5hmc marking and hypermethylation of essential pancreatic lineage transcription factors and 2) an emergence of trans-lineage/malignant feature, associated with the opening of AP-1 motif enriched chromatin regions. Gene perturbation screening identified FOSL2, FOS, and JUNB as pro-malignancy AP-1 factors during malignant transformation of POs. Notably, inhibition of ERK, a regulator of AP-1, not only reversed AP-1 levels and malignant feature in transformed POs, but also derepressed TET1 and its associated chromatin regions. Thus, our de novo PDAC POs faithfully model the disease development and reveal distinct but concerted mechanisms that drive the cellular plasticity in PDAC. The comprehensive validation of this model against clinical datasets approves its potential for discovery of therapeutic targets and biomarkers for preventive screening in the future.
Project description:We established a human pluripotent stem cell (hPSC)-derived pancreatic progenitor organoid (PO) culture that provides the cellular plasticity for PDAC modeling and supports robust gene editing. Through the combinatorial expression of oncogenic KRAS and deletion of multiple tumor suppressor genes (TSGs),we successfully recapitulated the transcriptional hallmarks of initial malignant transformation and progression of PDAC in POs in vitro. Moreover, these POs exhibited distinct histopathology from preneoplastic pancreatic intraepithelial neoplasia (PanIN) and moderately differentiated to poorly differentiated PDAC upon orthotopic transplantation. Further chromatin accessibility profiling unveiled 1) a progressive loss of pancreatic lineage program during disease development, accompanied by repression of TET1, 5hmc marking and hypermethylation of essential pancreatic lineage transcription factors and 2) an emergence of trans-lineage/malignant feature, associated with the opening of AP-1 motif enriched chromatin regions. Gene perturbation screening identified FOSL2, FOS, and JUNB as pro-malignancy AP-1 factors during malignant transformation of POs. Notably, inhibition of ERK, a regulator of AP-1, not only reversed AP-1 levels and malignant feature in transformed POs, but also derepressed TET1 and its associated chromatin regions. Thus, our de novo PDAC POs faithfully model the disease development and reveal distinct but concerted mechanisms that drive the cellular plasticity in PDAC. The comprehensive validation of this model against clinical datasets approves its potential for discovery of therapeutic targets and biomarkers for preventive screening in the future.
Project description:This study is an analysis of changes in gene expression during stringent response in Vibrio cholerae. V. cholerae cells in mid-log were treated with serine hydroxamate and gene expression was compared to untreated cells. Keywords: Stress response, stringent response
Project description:Type VI secretion systems (T6SS) are widely distributed among Vibrio species, yet their roles in the coexistence of toxigenic and non- toxigenic strains remain unclear. Here, we report a novel orphan T6SS effector-immunity module, TseVs-TsiVs, primarily harbored by non- toxigenic Vibrio cholerae. TseVs exhibits robust vibriocidal activity, specifically targeting susceptible Vibrios (lacking TsiVs). TseVs forms dual-membrane, ion-selective pores that collapse Na⁺/K⁺ homeostasis, resulting in membrane depolarization and ATP depletion. Remarkably, non-Vibrio bacteria evade TseVs through proton motive force (PMF)-dependent resilience, uncovering a previously unrecognized immunity-independent defense strategy. Furthermore, tseVs+ non- toxigenic V. cholerae strains are globally distributed and have dominated in recent decades, highlighting TseVs’s ecological significance in Vibrio population dynamics. By linking TseVs’s bioenergetic assassination to Vibrio population shifts, we demonstrate how T6SS effectors shape microbial genetic diversity. Our findings suggest that TseVs represents a promising model for precision antimicrobial strategies, minimizing collateral damage to commensal microbiota.
Project description:In marine Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome via homologous recombination. Expression of the master competence regulator TfoX bypasses the need for chitin induction and drives expression of the genes required for competence in several Vibrio species. Here, we show that TfoX expression in two Vibrio campbellii strains, DS40M4 and NBRC 15631, enables high frequencies of natural transformation. Conversely, transformation was not achieved in the model quorum-sensing strain V. campbellii BB120 (previously classified as Vibrio harveyi). Surprisingly, we find that quorum sensing is not required for transformation in V. campbellii DS40M4. This result is in contrast to Vibrio cholerae that requires the quorum-sensing regulator HapR to activate the competence regulator QstR. However, similar to V. cholerae, QstR is necessary for transformation in DS40M4. To investigate the difference in transformation frequencies between BB120 and DS40M4, we used previously studied V. cholerae competence genes to inform a comparative genomics analysis coupled with transcriptomics. BB120 encodes homologs of all known competence genes, but most of these genes were not induced by ectopic expression of TfoX, which likely accounts for the non-functional natural transformation in this strain. Comparison of transformation frequencies among Vibrio species indicates a wide disparity among even closely related strains, with Vibrio vulnificus having the lowest functional transformation frequency. We show that ectopic expression of both TfoX and QstR is sufficient to produce a significant increase in transformation frequency in Vibrio vulnificus.