Project description:Non-small cell lung cancer (NSCLC) is highly malignant with limited treatment options due to the inherent tumoral heterogeneity and acquired resistance towards chemotherapy and immunotherapy. RG7388 was previously reported to have anticancer activity against TP53WT NSCLC which was designed as MDM2 inhibitor triggering p53/PUMA axis-dependent apoptosis. However, RG7388 exhibited p53-independent anticancer effect against TP53mutant NSCLC in our current research, the underlying mechanisms of which were still uncertain. Here, we reported that RG7388 specifically induced NOXA/Caspase-3 axis dependent apoptosis and gasdermin E (GSDME)-mediated secondary pyroptosis in TP53mutant NSCLC using in silico and multiple biological methods. Mechanically, we identified accumulated reactive oxygen species (ROS) served as the pivotal factor in NOXA upregulation and p38 MAPK pathway activation in RG7388 treated TP53mutant NSCLC by using two ROS scavengers N-acetylcysteine (NAC) and Ferrostatin-1 (Fer-1) respectively. Furthermore, pharmacologic inhibition of p38 MAPK signaling by SB203580 rescued RG7388 induced ROS-dependent NOXA accumulation and subsequent apoptosis and pyroptosis, thus suggesting a leading role of ROS/phosphorylated p38 MAPK (p-p38)/NOXA/Caspase-3 axis in RG7388 induced TP53mutant NSCLC cell death. Taken together, our work unraveled a novel mechanism of selective targeting of mutant p53 derived cancers via ROS/p-p38-mediated NOXA accumulation that could have potential therapeutic implications given the relative lack of direct mutant p53 targeting strategies in cancer. Moreover, A strong positive correlation between p-p38 and NOXA expression was confirmed by using an NSCLC tissue microarray and immunohistochemical (IHC) staining. Clinical data analysis suggested that the p-p38/NOXA axis could serve as a potential indicator for predicting overall survival (OS) in NSCLC patients.
Project description:It is widely acknowledged that gasdermin family proteins, which are known as the executors of pyroptosis, undergo protease-mediated cleavage prior to inducing pyroptosis. Here, we unexpectedly discovered a non-canonical form of pyroptosis mediated by full-length GSDME (FL-GSDME) without any proteolytic cleavage. Upon intense ultraviolet (UV) irradiation-triggered DNA damage, hyperactivation of nuclear PARP1 led to extensive formation of poly(ADP-ribose) (PAR) polymers and then release to the cytoplasm.These PAR polymers activate PARP5 to catalyze GSDME PARylation, resulted in a conformational change in GSDME that relieved autoinhibition imposed by its C terminus on the N terminus. On the other hand, intense UV irradiation boosted mitochondrial fission-dependent generation of mitochondrial reactive oxygen species (mito-ROS), further promoting cytochrome c-catalyzed peroxidation of cardiolipin. This lipid-ROS signal was then sensed by PARylated-GSDME and then induced oxidative oligomerization of GSDME, which facilitated FL-GSDME plasma membrane targeting for perforation, eventually inducing pyroptosis. Reagents that concurrently stimulate PARPs activity and lipid-ROS also induced sequential modifications i.e., PARylation and oxidation of FL-GSDME and synergistically promoted pyroptotic cell death. Overall, our findings elucidate a novel mechanism underlying cleavage-independent function of GSDME in executing cell demise, further enriching the paradigms and cognition of FL-GSDME-mediated non-canonical pyroptosis.
Project description:Acute kidney injury(AKI) is associated with an increased risk of chronic kidney disease(CKD). There is still a lack of effective prevention for AKI-CKD transition. In the present study, we simultaneously explored the contribution of GSDMD and GSDME in folic acid (FA)-induced nephropathy, a model mimicking the essential components of the AKI-CKD transition. We found that blockage of both GSDMD and GSDME-mediated pyroptosis could have accumulative protection against FA-induced AKI-CKD transition. GSDME-mediated pyroptosis played a crucial role in tubular cell damage. GSDMD could exert important functions in infiltration of inflammatory cells and NETs formation. Pyroptotic tubular cells triggered NETs generation and macrophage polarization. NETs promoted macrophage-to-myofibroblast transition. Our results illustrated the orchestration of GSDMD and GSDME in AKI-CKD transition, providing new insights into the molecular mechanism for the clinical dilemma.
Project description:Millions of patients suffer from silicosis, but it remains an uncurable disease due to its unclear pathogenic mechanisms. Though the Nlrp3 inflammasome is involved in silicosis pathogenesis, inhibition of its classic downstream factors, Caspase-1 and Gsdmd, fails to block pyroptosis and cytokine release. To clarify the molecular mechanism of silicosis pathogenesis for new therapy, we examined samples from silicosis patients and genetic mouse models. We discovered an alternative pyroptotic pathway which requires cleavage of Gsdme by Caspases-3/8 in addition to Caspase-1/Gsdmd. Consistently, Gsdmd-/-Gsdme-/- mice showed markedly attenuated silicosis pathology, and Gsdmd-/-Gsdme-/- macrophages were resistant to silica-induced pyroptosis. Furthermore, we found that in addition to Caspase 1, Caspase-8 cleaved IL-1β in silicosis, explaining why Caspase-1-/- mice also suffered from silicosis. Finally, we found that inhibitors of Caspase-1, -3, -8 or an FDA approved drug, dimethyl fumarate, could dramatically alleviate silicosis pathology through blocking cleavage of Gsdmd and Gsdme. This study highlights that Caspase-1/Gsdmd and Caspase-3/8/Gsdme-dependent pyroptosis is essential for the development of silicosis, implicating new potential targets and drug for silicosis treatment.
Project description:Cannabidiol (CBD), a phytochemical derived from Cannabis sativa L., has been demonstrated to exhibit promising anti-tumor properties in multiple cancer types. However, the effects of CBD on Hepatocellular carcinoma cells (HCC) remains unknown. We have shown that CBD effectively suppresses HCC cell growth in vivo and in vitro, and induced HCC cell pyroptosis in a caspase-3/GSDME-dependent manner. We further demonstrated that accumulation of Integrative Stress Response (ISR) and mitochondrial stress may contribute to the initiation of pyroptotic signaling by CBD. Simultaneously, CBD can repress aerobic glycolysis through modulation of the ATF4-IGFBP1-Akt axis, due to the depletion of ATP and crucial intermediate metabolites. Collectively, these observations indicate that CBD could be considered as a potential compound for HCC therapy.
Project description:Investigation of NOXA dependent apoptosis in pancreatic cancer cell lines with CRISPR/Cas9 mediated knockouts for NOXA and RUNX1 including parental cell lines.
Project description:The aim of this study was to explore the transciptome of the diverse vascular smooth muscle cells subsets from abdominal aortic aneurysm tissues in Gsdme deletion mice.The model was established by exposing the infrarenal aorta to PPE (porcine pancreatic elastase) under pressure to induce aneurysmal degeneration for 4 weeks.we compared the characteristics of SMC subpopulation beteew the WT and KO groupsto reveal the effect of GSDME in the progression of Abdomanl Aortic Aneurysm.
Project description:The ubiquitin-proteasome system (UPS) has recently emerged as a major target for drug development in cancer therapy. The proteasome inhibitor bortezomib has clinical activity in multiple myeloma and mantle cell lymphoma. Here we report that Eeyarestatin I (EerI), a chemical inhibitor that blocks ER-associated protein degradation (ERAD), has anti-tumor and biologic activities similar to bortezomib, and can synergize with bortezomib. Like bortezomib, EerI-induced cytotoxicity requires the upregulation of the BH3 only pro-apoptotic protein NOXA. We further demonstrate that both EerI and bortezomib activate NOXA via an unanticipated mechanism that requires cooperation between two processes: First, these agents elicit an integrated stress response program at the ER to activate the CREB/ATF transcription factors ATF3 and ATF4. We show that ATF3 and ATF4 form a complex capable of binding to the NOXA promoter, which is required for NOXA activation. Second, EerI and bortezomib also block ubiquitination of histone H2A to relieve its inhibition on NOXA transcription. Our results identify a class of anti-cancer agents that integrate ER stress response with an epigenetic mechanism to induce cell death.
Project description:Bortezomib (BZM) is the first proteasome inhibitor approved for relapsed Mantle Cell Lymphoma (MCL) with durable responses seen in 30%-50% of patients. The biological basis for differences in response to BZM is not completely understood. Our previous work demonstrated marked differences in methylation between primary MCL and normal B cells. We hypothesized that a subset of aberrantly methylated genes may be modulating BZM response in MCL patients. We examined genome-wide DNA methylation profiles in MCL patient treated with BZM using a NimbleGen array platform. DNA methylation analysis revealed a striking promoter hypomethylation in MCL patient samples following BZM treatment. Pathway analysis of differentially methylated genes identified molecular mechanisms of cancer as a top canonical pathway enriched among hypomethylated genes in BZM treated samples. Noxa, a pro-apoptotic Bcl-2 family member essential for the cytotoxicity of BZM, was significantly hypomethylated and induced following BZM treatment. Therapeutically, we could demethylate Noxa and induce anti-lymphoma activity using BZM and the DNA methytransferase inhibitor Decitabine (DAC) and their combination in vitro and in vivo in BZM resistant MCL cells. Noxa depletion by RNA interference protected MCL cells from death by these agents. These findings suggest a role for dynamic Noxa methylation for therapeutic benefit of BZM. Potent and synergistic cytotoxicity between BZM and DAC in vitro and in vivo supports a strategy for using epigenetic priming to overcome BZM resistance in relapsed MCL patients. Our data demonstrate that genomic methylation profiling can provide mechanistic insights to guide novel therapeutic approaches.