Cell Death & Disease最新文献

Insufficient cytotrophoblast (CTB) migration and invasion into the maternal myometrium leads to pregnancy related complications like Intra-uterus Growth Restriction (IUGR), and pre-eclampsia (PE). We previously found that hydrogen sulfide (H₂S) enhanced CTB migration without knowing the mechanism(s) and the pathophysiological significance. By studying human samples and cell line, we found that H₂S levels were lower in PE patients' plasma; H₂S synthetic enzyme cystathionine β-synthetase (CBS) was reduced in PE extravillious invasive trophoblasts. GYY4137 (H₂S donor, 1 µM) promoted CBS/H₂S translocation onto mitochondria, preserved mitochondria functions, enhanced cell invasion and migration. CBS knockdown hindered the above functions which were rescued by GYY4137, indicating the vital roles of CBS/H₂S signal. Disturbance of mitochondria dynamics inhibited cell invasion and migration. The 185 and 504 cysteines of Mitochondrial Rho GTPase 2 (Miro2^C185/C504) were highly sulfhydrated by H₂S. Knockdown Miro2 or double mutation of Miro2^C185/^C504 to serine fragmented mitochondria, and inhibited cell invasion and migration which can't be rescued by H₂S. The present study showed that human cytotrophoblast receives low dose H₂S regulation; CBS/H₂S sustained mitochondria functions via Miro2^C185/C504 sulfhydration to enhance cytotrophoblast mobility. These findings established a new regulatory pathway for cytotrophoblast functions, and provided new targets for IUGR and PE.

Glioblastoma accounts for nearly half of all primary malignant brain tumors in adults, and despite an aggressive standard of care, including excisional surgery and adjuvant chemoradiation, recurrence remains universal, with an overall median survival of 14.6 months. Recent work has revealed the importance of passenger mutations as critical mediators of metabolic adaptation in cancer progression. In our previous work, we identified a role for the epigenetic modifier ID-1 in temozolomide resistance in glioblastoma. Here, we show that ID-1-mediated glioblastoma tumourigenesis is accompanied by upregulation of one-carbon (1-C) mediated de novo purine synthesis. ID-1 knockout results in a significant reduction in the expression of 1-C metabolism and purine synthesis enzymes. Analysis of glioblastoma surgical specimens at initial presentation and recurrence reveals that 1-C purine synthesis metabolic enzymes are enriched in recurrent glioblastoma and that their expression correlates with a shorter time to tumor recurrence. Further, we show that the 1-C metabolic phenotype underlies proliferative capacity and temozolomide resistance in glioblastoma cells. Supplementation with exogenous purines restores proliferation in ID-1-deficient cells, while inhibition of purine synthesis with AICAR sensitizes temozolomide-resistant glioblastoma cells to temozolomide chemotherapy. Our data suggest that the metabolic phenotype observed in treatment-resistant glioma cells is a potential therapeutic target in glioblastoma.

Niemann-Pick disease Type C (NPC) is caused by mutations in the cholesterol transport protein NPC1 leading to the endolysosomal accumulation of the lipid and to psychiatric alterations. Using an NPC mouse model (Npc1^nmf164) we show aberrant mGluR₅ lysosomal accumulation and reduction at plasma membrane in NPC1 deficient neurons. This phenotype was induced in wild-type (wt) neurons by genetic and pharmacological NPC1 silencing. Extraction of cholesterol normalized mGluR₅ distribution in NPC1-deficient neurons. Intracellular accumulation of mGluR₅ was functionally active leading to enhanced mGluR-dependent long-term depression (mGluR-LTD) in Npc1^nmf164 hippocampal slices. mGluR-LTD was lower or higher in Npc1^nmf164 slices compared with wt when stimulated with non-membrane-permeable or membrane-permeable mGluR₅ agonists, respectively. Oral treatment with the mGluR₅ antagonist 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine (CTEP) reduced mGluR-LTD and ameliorated psychiatric anomalies in the Npc1^nmf164 mice. Increased neuronal mGluR₅ levels were found in an NPC patient. These results implicate mGluR₅ alterations in NPC psychiatric condition and provide a new therapeutic strategy that might help patients suffering from this devastating disease.

Lung squamous cell carcinoma (LUSC) is associated with high mortality and has few therapeutic options. Chemotherapy remains the main treatment for LUSC patients, but multi-drug resistance has become the dominant challenge in the failure of chemotherapy in various cancers. Therefore, the effective therapeutic strategy for LUSC patients is an urgent unmet need. Here, we found vasohibin-2 (VASH2) was a prognostic biomarker for LUSC patients, and VASH2 promoted the malignant biological behaviors of LUSC cells and chemoresistance by increasing the detyrosination of α-tubulin. The high level of detyrosinated-tubulin was negatively associated with patient prognosis. Blocking the tubulin carboxypeptidase (TCP) activity of VASH2 inhibited the xenograft tumor growth and improved the treatment efficacy of paclitaxel in vivo. Results revealed that VASH2-induced increase in tubulin detyrosination boosted the binding of kinesin family member 3C (KIF3C) to microtubules and enhanced KIF3C-dependent endosomal recycling of EGFR, leading to the prolonged activation of PI3K/Akt/mTOR signaling. This study demonstrated that VASH2 was not only a prognostic biomarker but also a promising therapeutic target in LUSC, which offers a novel insight that combination of chemotherapy and EpoY, a TCP inhibitor, may be a promising treatment strategy for LUSC patients.

Nonalcoholic steatohepatitis (NASH) is a prevalent chronic disease, yet its exact mechanisms and effective treatments remain elusive. Nuclear receptor subfamily 5 group A member 2 (NR5A2), a transcription factor closely associated with cholesterol metabolism in the liver, has been hindered from comprehensive investigation due to the lethality of NR5A2 loss in cell lines and animal models. To elucidate the role of NR5A2 in NASH, we generated hepatocyte-specific knockout mice for Nr5a2 (Nr5a2^HKO) and examined their liver morphology across different age groups under a regular diet. Furthermore, we established cell lines expressing haploid levels of NR5A2 and subsequently reintroduced various isoforms of NR5A2. In the liver of Nr5a2^HKO mice, inflammation and fibrosis spontaneously emerged from an early age, independent of lipid accumulation. Pyroptosis occurred in NR5A2-deficient cell lines, and different isoforms of NR5A2 reversed this form of cell death. Our findings unveiled that inhibition of NR5A2 triggers pyroptosis, a proinflammatory mode of cell death primarily mediated by the activation of the NF-κB pathway induced by reactive oxygen species (ROS). As a transcriptionally regulated molecule of NR5A2, aldehyde dehydrogenase 1 family member B1 (ALDH1B1) participates in pyroptosis through modulation of ROS level. In conclusion, the diverse isoforms of NR5A2 exert hepatoprotective effects against NASH by maintaining a finely tuned balance of ROS, which is contingent upon the activity of ALDH1B1.

Liver kinase B1 (LKB1) is a serine/threonine kinase controlling cell homeostasis. Among post-translational modification, Sumoylation is vital for LKB1 activating adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), the key regulator in energy metabolism. Of note, AMPK-regulated fatty acid metabolism is highly involved in maintaining normal renal function. However, the regulative mechanisms of LKB1 Sumoylation remain elusive. In this study, we demonstrated that β-catenin, a notorious signal in renal fibrosis, inhibited the Sumoylation of LKB1, thereby disrupting fatty acid oxidation in renal tubular cells and triggering renal fibrosis. Mechanically, we found that Sumo3 was the key mediator for LKB1 Sumoylation in renal tubular cells, which was transcriptionally inhibited by β-catenin/Transcription factor 4 (TCF4) signaling. Overexpression of Sumo3, not Sumo1 or Sumo2, restored β-catenin-disrupted fatty acid metabolism, and retarded lipid accumulation and fibrogenesis in the kidney. In vivo, conditional knockout of β-catenin in tubular cells effectively preserved fatty acid oxidation and blocked lipid accumulation by maintaining LKB1 Sumoylation and AMPK activation. Furthermore, ectopic expression of Sumo3 strongly inhibited Wnt1-aggravated lipid accumulation and fibrogenesis in unilateral ischemia-reperfusion mice. In patients with chronic kidney disease, we found a loss of Sumo3 expression, and it was highly related to LKB1 repression. This contributes to fatty acid metabolism disruption and lipid accumulation, resulting in renal fibrosis. Overall, our study revealed a new mechanism in fatty acid metabolism dysfunction and provided a new therapeutic target pathway for regulating Sumo modification in renal fibrosis.

Non-small cell lung cancer (NSCLC) remains a cause for concern as the leading cause of cancer-related death worldwide. Amidst ongoing debates on the role and mechanisms of methionine adenosyltransferase 1A (MAT1A) in cancer, our study sheds light on its significance in NSCLC. Leveraging TCGA database and immunohistochemical staining, we systematically analyzed MAT1A expression in NSCLC, uncovering its marked upregulation. To unravel the functional and mechanistic underpinnings, we implemented stable knockdown of MAT1A in NSCLC cell lines. Our findings converged to demonstrate that suppression of MAT1A expression effectively impeded the proliferation and migratory capabilities of NSCLC cells, while concurrently enhancing apoptosis. Mechanistically, we discovered that MAT1A depletion accelerated the degradation of CCND1, a key cell cycle regulator, through S-phase kinase-associated protein 2 (SKP2)-mediated ubiquitination. Notably, CCND1 emerged as a crucial MAT1A partner, jointly orchestrating glycolytic metabolism in NSCLC cells. This intricate interplay suggests that MAT1A promotes NSCLC progression by safeguarding CCND1 protein stability and activating glycolytic pathways, thereby sustaining tumorigenesis. In summary, our study not only identifies MAT1A as a prognostic marker for poor survival in NSCLC patients but also elucidates its mechanistic contributions to cancer progression. These findings pave the way for the development of targeted therapies aimed at disrupting the deleterious MAT1A-CCND1-glycolysis axis in NSCLC.

Necroptosis and ferroptosis are two distinct forms of necrotic-like cell death in terms of their morphological features and regulatory mechanisms. These two types of cell death can coexist in disease and contribute to pathological processes. Inhibition of both necroptosis and ferroptosis has been shown to enhance therapeutic effects in treating complex necrosis-related diseases. However, targeting both necroptosis and ferroptosis by a single compound can be challenging, as these two forms of cell death involve distinct molecular pathways. In this study, we discovered that KW-2449, a previously described necroptosis inhibitor, also prevented ferroptosis both in vitro and in vivo. Mechanistically, KW-2449 inhibited ferroptosis by targeting the autophagy pathway. We further identified that KW-2449 functioned as a ULK1 (Unc-51-like kinase 1) inhibitor to block ULK1 kinase activity in autophagy. Remarkably, we found that Necrostatin-1, a classic necroptosis inhibitor that has been shown to prevent ferroptosis, also targets the autophagy pathway to suppress ferroptosis. This study provides the first understanding of how necroptosis inhibitors can prevent ferroptosis and suggests that autophagy is a targetable pathway for necroptosis inhibitors to prevent ferroptosis. Therefore, the identification and design of pharmaceutical molecules that target the autophagy pathway from necroptosis inhibitors is a promising strategy to develop dual inhibitors of necroptosis and ferroptosis in clinical application.

Chemotherapy resistance has been a great challenge in pancreatic ductal adenocarcinoma(PDAC) treatments. Current first-line chemotherapy regimens for PDAC include gemcitabine-based regimens such as AG regimen (albumin paclitaxel and gemcitabine), fluorouracil-based regiments such as FOLFIRINOX regimen ((5-fluorouracil5-FU), oxaliplatin, Irinotecan) and platinum-based regimens for patients with BRCA mutations. large amounts of work have been done on exploring the mechanism underlying resistance of gemcitabine-based and platinum-based regimens, while little research has been achieved on the mechanism of FOLFIRINOX regimens resistance. Hence, we identified Polypeptide N-Acetylgalactosaminyltransferase 5, (GALNT5) as a vital regulator and a potential therapeutic target in FOLFIRINOX regimens resistance. Colony formation assays and flow cytometry assays were performed to explore the roles of GALNT5 in cell proliferation and apoptosis in PDAC treated with FOLFIRINOX. IC50 alterations were calculated in GALNT5 knockdown and overexpressed cell lines. RNA-seq followed by GSEA (gene set enrichment analysis) was displayed to explore the potential mechanism. WB (western blotting), real-time PCR, and IF (immunofluorescence) were performed to validate relative pathways. The mouse orthotopic xenograft PDAC model was established to examine GALNT5 functions in vivo. GALNT5 was highly expressed in PDAC tissues and predicted poor prognosis in PDAC. Upregulation of GALNT5 in PDAC cells conferred FOLFIRINOX resistance on PDAC by inhibiting DNA damage. Moreover, GALNT5 interacted with MYH9, thus participating in the activation of the NOTCH pathways, resulting in hampering FOI-induced DNA damage. Functions of GALNT5 promoting FOLFIRINOX resistance were validated in vivo. In this study, we found that aberrantly overexpressed GALNT5 in PDAC took part in the activation of the NOTCH pathway by interacting with MYH9, thus inhibiting the DDR to achieve FOLFIRINOX resistance and causing poor prognosis. We identified GALNT5 as a potential therapeutic target for PDAC patients resistant to FOLFIRINOX chemotherapy.