Project description:Single-cell mRNA sequencing (scRNA-seq) study was conducted to compare the transcriptomes of SULT2B1b knockdown (KD) versus non-targeting (Control) KD LNCaP cells. Over 2,000 differentially expressed (DE) genes were identified along with alterations in numerous canonical pathways, including the death receptor signaling pathway.
Project description:TNF is a key component of the innate immune response. Upon binding to its receptor, TNFR1, it promotes production of other cytokines via a membrane-bound complex 1, or induces cell death via a cytosolic complex 2. To understand how TNF-induced cell death is regulated we performed mass spectrometry of complex 2 and identified tankyrase-1 as a native component that, upon a death stimulus, mediates complex 2 poly-ADP-ribosylation (PARylation). PARylation promotes recruitment of the E3 ligase RNF146 resulting in proteasomal degradation of complex 2 thereby limiting cell death. Intriguingly, expression of the ADP-ribose binding/hydrolyzing SARS-CoV-2 macrodomain sensitizes cells to TNF-induced death via abolishing complex 2 PARylation. This suggests that disruption of ADP-ribosylation during an infection can prime a cell to retaliate with an inflammatory cell death.
Project description:Withaferin A (WA), a major chemical component of an Indian herb Withania somnifera, induces cell death (apoptosis/necrosis) in a variety of tumor cells, but its molecular mechanism remains elusive. We report that WA induces cell death selectively in high-grade prostate (PC-3 and DU-145) and tongue (SAS) cancer cells but not in normal human fibroblast (TIG-1) and low-grade prostate cancer (LNCaP) cells. To identify genes whose expression levels were up- or down-regulated in prostate cancer cells following WA treatment, we examined the transcriptome profiles of mRNA prepared from TIG-1, LNCaP, PC-3 and DU-145 cells using Agilent’s Whole Human Genome Microarray.
Project description:A20 is known key regulator of NF-κB activity and inflammatory response, but its role in the control of cell death receptor signaling is not completely understood. Although A20 is widely accepted anti-apoptotic protein, we demonstrate that elevated expression of A20 in both, human and murine keratinocytes results in sensitisation to TNF-induced cell death. We prove that the Ripoptosome formation in A20 overexpressing cells is prerequisite for the TNF-induced cell death execution. We demonstrate that both canonical and non-canonical NF-κB signaling pathways are regulated upon increase of A20 expression. A20 dependent alteration of cIAPs and TRAF1 expressions are involved in the multiple level control of cell death in keratinocytes with elevated A20 expression.
Project description:A20 is known key regulator of NF-κB activity and inflammatory response, but its role in the control of cell death receptor signaling is not completely understood. Although A20 is widely accepted anti-apoptotic protein, we demonstrate that elevated expression of A20 in both, human and murine keratinocytes results in sensitisation to TNF-induced cell death. We prove that the Ripoptosome formation in A20 overexpressing cells is prerequisite for the TNF-induced cell death execution. We demonstrate that both canonical and non-canonical NF-κB signaling pathways are regulated upon increase of A20 expression. A20 dependent alteration of cIAPs and TRAF1 expressions are involved in the multiple level control of cell death in keratinocytes with elevated A20 expression.
Project description:Withaferin A (WA), a major chemical component of an Indian herb Withania somnifera, induces cell death (apoptosis/necrosis) in a variety of tumor cells, but its molecular mechanism remains elusive. We report that WA induces cell death selectively in high-grade prostate (PC-3 and DU-145) and tongue (SAS) cancer cells but not in normal human fibroblast (TIG-1) and low-grade prostate cancer (LNCaP) cells.
Project description:Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a cytosolic protein kinase that regulates multiple inflammatory and cell death pathways. Serine/Threonine phosphorylation of RIPK1 is known to suppress RIPK1 kinase-mediated cell death in the contexts of inflammation, infection and embryogenesis, however, regulation by tyrosine phosphorylation has not been reported. Here, we show that non-receptor tyrosine kinases Janus kinase 1 (JAK1) and SRC are able to phosphorylate RIPK1 at Y384 (Y383 in murine RIPK1), leading to suppression of TNF-induced cell death. Mice bearing a homozygous Ripk1 mutation that prevents tyrosine phosphorylation of RIPK1 (Ripk1Y383F/Y383F), develop systemic inflammation and emergency haematopoiesis. Mechanistically, Ripk1Y383F/Y383F mutation promotes RIPK1 kinase activation and enhances TNF-induced apoptosis and necroptosis, which is partially due to impaired recruitment and activation of MAP kinase-activated protein kinase 2 (MK2). The systemic inflammation and emergency haematopoiesis in Ripk1Y383F/Y383F mice are largely alleviated by RIPK1 kinase inhibition, and prevented by genomic deletions targeted to the upstream pathway (either to Tumor necrosis factor receptor 1 or RIPK3 and Caspase8 simultaneously). In summary, our results demonstrate that tyrosine phosphorylation of RIPK1 is critical for regulating RIPK1 activity to limit cell death and inflammation.