Cell Death & Disease最新文献

Hepatocellular carcinoma (HCC) is characterized by high invasiveness and metastatic potential, leading to poor prognosis. Therefore, understanding the molecular mechanisms underlying HCC invasion and metastasis is essential for developing effective therapeutic strategies. This study investigates the role of ZMYM3 in HCC invasion and metastasis. Analysis of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets, along with immunohistochemistry, revealed that ZMYM3 is upregulated in HCC tissues and associated with recurrence and poor prognosis. Single-cell sequencing data indicated higher ZMYM3 expression in portal vein tumor thrombus compared to primary lesions, suggesting its involvement in metastasis. Functional assays demonstrated that ZMYM3 enhances HCC cell proliferation, invasion, and metastasis. RNA sequencing identified that ZMYM3 promotes invadopodia formation and epithelial-mesenchymal transition (EMT) in HCC cells. Further chromatin immunoprecipitation sequencing and mechanistic studies showed that ZMYM3 directly binds to the promoter of CTTN, a key gene regulating invadopodia formation, thereby increasing its expression. This upregulation contributes to the enhanced invasive and metastatic capabilities of HCC cells. Our findings identify ZMYM3 overexpression as a predictor of high recurrence risk and poor prognosis in HCC patients. Mechanistically, ZMYM3 promotes invadopodia formation primarily through the upregulation of CTTN, thereby augmenting the invasive and metastatic potential of HCC cells. These results highlight the critical role of ZMYM3 in HCC progression and metastasis.ZMYM3 promotes hepatocellular carcinoma metastasis by upregulating CTTN and inducing invadopodia formation.

Photoreceptor degeneration in Retinitis pigmentosa (RP) is the most prevalent cause of inherited legal blindness, for which effective visual restoration treatments are still missing. Injectable prosthetic strategies represent a promising tool for vision restoration. We demonstrated that injectable poly(3-hexylthiophene) nanoparticles (P3HT-NPs) promote a sustained visual restoration in Royal College of Surgeons rats, an RP model harboring a mutation that impairs the phagocytic activity of the retinal pigment epithelium (RPE) and microglia, leading to progressive and combined rod/cone degeneration. However, it is unclear whether the efficacy of P3HT-NPs in this model is enhanced by the impairment of RPE and microglial phagocytosis, and thus whether this prosthetic intervention will also be effective in more typical forms of RP that primarily affect rods. Here, we evaluated the efficacy of P3HT-NPs in the pigmented retinal degeneration 10 (rd10) mouse, which carries a recessive missense mutation in the rod phosphodiesterase-6B gene, while retaining a morphologically and functionally intact RPE. We demonstrate that, in this mouse model of RP, P3HT-NPs restore visually driven responses at both subcortical and cortical levels at the end stage of photoreceptor degeneration. Although partial phagocytosis of P3HT-NPs by the RPE occurs, the P3HT-NPs remaining in the outer retina were sufficient to mediate a significant recovery of visual function characterized by complex light-dependent reactivation of the primary visual cortex and formation of implicit visual memories. These results demonstrate that healthy RPE and microglial activities do not compromise the efficacy of the injectable nanotherapeutic strategy, underscoring the clinical potential of P3HT-NPs for visual restoration in late-stage retinal degeneration, which closely mimics the conditions of RP patients undergoing prosthetic interventions.

Successful pregnancy requires precise immune interactions between fetal extravillous trophoblasts (EVT) and maternal decidual immune cells at the maternal-fetal interface. Glycosylation, particularly terminal sialylation, is emerging as a key modulator of these interactions; however, its functional role in regulating the EVT-immune crosstalk remains poorly defined. Here, we aimed to identify a critical sialic acid-Siglec-7-IL-8-STAT3 signaling axis that promotes EVT invasiveness and is disrupted during recurrent pregnancy loss (RPL). Using primary human tissues and organ-on-chip models, we demonstrate that EVTs from patients with RPL exhibit reduced sialylation, coinciding with an increased proportion of Siglec-7⁺ decidual natural killer (dNK) cells. Mechanistically, sialylated glycoproteins on EVT surfaces engage Siglec-7, stimulating IL-8 secretion by dNK cells, which, in turn, activates STAT3 in EVTs to enhance migration and invasion. Restoration of EVT sialylation re-engages Siglec-7, rescues IL-8-STAT3 signaling, and restores invasive capacity. Our findings reveal that defective EVT sialylation disrupts a key immunological checkpoint that normally promotes EVT invasion and potentially contributes to RPL. This work provides direct mechanistic evidence that specific glycan-encoded immune signals at the maternal-fetal interface are critical for healthy pregnancy outcomes and suggests that modulating sialylation may offer a therapeutic strategy for RPL.Proposed model of sialic acid-Siglec-7-mediated regulation of EVT invasion through the ST6GALNAC6-sialic acid-Siglec-7-IL-8-STAT3 signaling axis. Schematic representation of the working model: enhanced sialylation of EVT membrane glycoproteins-driven by ST6GALNAC6-facilitates recognition by Siglec-7 expressed on dNK cells. This interaction promotes the activation of the IL-8-STAT3 signaling pathway, which supports EVT cell migration and invasion. Disruption of sialylation or Siglec-7 engagement impairs this pathway and reduces EVT invasiveness, potentially contributing to the pathogenesis of RPL. Figure created with BioRender.com (https://BioRender.com/dxxt5az).

Shp1 is a cytosolic tyrosine phosphatase generally associated with antitumor effects through the inhibition of tyrosine kinase signaling. Herein, we shown that genetic and pharmacological inhibition of Shp1 in breast cancer cells induces accelerated cell migration and promotes a more invasive phenotype. Furthermore, we found that interleukin-8 (IL8), a chemokine with multiple pro-tumorigenic roles within the tumor microenvironment, directly modulates Shp1 activity. In breast cancer, IL8 elicits its functions through the binding to the CXCR2 receptor with the subsequent modulation of several intracellular signaling pathways. We show that in breast MCF7 cells, IL8 induces the PKC-mediated phosphorylation of Shp1 at Ser591, diminishing its enzymatic activity and impairing the dephosphorylation of PP2A; this enhances CXCR2 phosphorylation and alters receptor trafficking by promoting ubiquitination and degradation of CXCR2. This feedback mechanism limits IL8 signaling revealing a previously unrecognized mechanism of receptor turnover and signal attenuation. In addition, we found that Shp1-mediated regulation of CXCR2 directly influences IL8-driven invasiveness in a subtype-specific manner, affecting luminal and triple-negative breast cancer (TNBC) cells but not HER2-positive ones. Transcriptomic and pathway analyses further support Shp1 involvement in cytokine and GPCR signaling, particularly in TNBC, where its downregulation correlates with reduced survival and higher IL8 levels. Taken together, our findings elucidate a novel mechanism of IL8 signaling and identify Shp1 as a promising therapeutic target, highlighting the potential of modulating the CXCR2-Shp1 axis to limit invasiveness and metastasis in aggressive breast cancer subtypes, particularly TNBC.

Ataxia telangiectasia (AT) is a rare multisystem disorder caused by the loss of functional ATM protein, leading to immunodeficiency, cancer predisposition, neurodegeneration, diabetes, heart failure, and premature aging. Although ATM's role as a sensor of DNA double-strand breaks (DSBs) is well established, the mechanisms underlying the diverse AT phenotypes remain incompletely understood, with evidence suggesting they extend beyond DSB sensing. Here, we uncover widespread glycogen accumulation as a key feature of AT cells and tissues, driven by dysregulated glucose metabolism and impaired mitochondrial respiration assessed with a multidimensional approach including metabolomics, flux analysis, histopathology, bioenergetic measurements, and electron tomography. These metabolic defects contribute to reduced cellular viability and premature senescence observed in AT patient-derived cells. Strikingly, inactivation of FNIP2, which controls mitochondrial respiration, partially rescues these defects in AT cellular models. We show that FNIP2 interacts with the SERCA2b calcium channel, and its inactivation enhances cytoplasmic calcium availability, stimulating mitochondrial respiration and increasing glucose consumption. This metabolic reprogramming prevents glycogen accumulation and improves survival in AT primary cells. Our findings provide novel insights into AT pathophysiology and indicate the FNIP2-SERCA2b axis as a novel potential target for mitigating the systemic effects of AT and improving outcomes in this complex disease.

The transition from mitosis to meiosis is crucial for determining the germ cell fate and ensuring the successive production of gametes. However, the mechanisms underlying meiotic entry within the dynamic chromatin context still remain poorly understood. Herein, we demonstrate that H3K9me2, a key marker of heterochromatin formation, plays a pivotal role in the transition from mitosis to meiosis in female germ cells of mice. We show that H3K9me2 maintains high levels in female germ cells from embryonic day 13.5 to 15.5, which closely corresponds to the timing of entry into meiosis in female mice. Interestingly, the reduction of H3K9me2 levels impairs the transition from pluripotency to meiosis in female germ cells, and the role of H3K9me2 appears to act upstream of Stra8 and Dazl. Mechanistically, the multi-omics sequencing analyses of sorted germ cells reveal that H3K9me2 is specifically enriched at the promoter region of pluripotency transcription factor SOX2 and components of the ATP-dependent chromatin remodeling complex. Reduction of H3K9me2 levels results in increased chromatin accessibility, specifically for the pluripotent factor and ATP-dependent chromatin remodelers, thereby impeding the complete exit from the pluripotency progression. Hence, our findings highlight the essential role of H3K9me2 in controlling the exit from the pluripotent state and coordinating the competency of female germ cells, thereby indicating the fundamental role of chromatin remodeling processes in mitosis-to-meiosis transition. This study will provide new insights into the role of chromatin remodeling in the process of gamete production from stem cell to germ cell in vitro.

Triple-negative breast cancer (TNBC) is a subtype characterized by the absence of common BC receptors and is closely associated with a hypoxic tumor microenvironment. However, the mechanisms through which TNBCs adapt to hypoxia remain elusive. This study revealed elevated ENO1 levels in various BC datasets and revealed ENO1 protein lactylation in BC samples through 4D label-free lactylation quantitative proteomics analysis. The results indicated that lactylation increases ENO1 protein stability and enzyme activity, which promotes glycolysis. Notably, as lactate levels increased, a positive feedback loop was established, further promoting lactylation of ENO1. This positive feedback mechanism enables TNBC cells to adapt more efficiently to hypoxia and enhances their malignant behaviors. Lactylation prevented the lysosomal degradation of ENO1. In this study, the characteristics of ENO1, an RNA-binding protein, were assessed to determine how to interfere with its lactylation; specifically, an RNA ligand that can be specifically bound by ENO1 was identified. The RNA ligand was found to be linked to the Lamp2a protein in adipose stem cells (ADSCs) after stable transfection with Lamp2a-TAT and TRA-ligand plasmids. ADSCs seeded in a polyglycolic acid scaffold secreted exosomes containing the Lamp2a-linked ligand. This RNA ligand binds to ENO1 after it enters TNBC cells and further induces the lysosomal degradation of ENO1 by the Lamp2a protein. Consequently, glycolysis, which is associated with malignant cell behaviors, is inhibited. Overall, this study elucidated the role of ENO1 lactylation-mediated glycolysis in TNBC adaptation to hypoxia and provides a strategy for targeting ENO1.

Pleural mesothelioma (PM) is an uncommon yet deadly cancer linked to asbestos exposure. The lack of effective early diagnosis and treatment leads to reduced life expectancy among patients with PM. This study aims to identify a novel molecular target inhibitor to develop more effective therapeutics for PM. Our drug screening assay showed that the fatty acid synthase (FASN) inhibitor cerulenin demonstrates strong and selective antiproliferative properties against NF2/CDKN2A(p16)-deficient PM cells, surpassing the effects of C75, cisplatin or pemetrexed. FASN protein is frequently detected in NF2/p16-deficient PM tumor-derived tissues (15/15, 100%), but rarely in NF2/p16-intact PM tumors (8/25, 32%). Notably, cerulenin administration successfully reduced the growth of NF2/p16-deficient PM tumors in xenografted mice. Cerulenin inhibits mitochondrial fission by targeting dynamin-related protein 1 (DRP1) in NF2/p16-deficient cells. Moreover, the disruption of the FASN gene leads to increased ubiquitination of DRP1. These findings suggest that FASN might play a role in the tumorigenesis of PM cells through the regulation of mitochondrial dynamics. This research offers a novel perspective on the potential development of precision medicine for PM.

Pathogenic germline TP53 variants predispose to diverse Li-Fraumeni syndrome (LFS) phenotypes and a broad cancer spectrum, whereby carriers of hypomorphic variants cluster in a cohort with attenuated disease onset and an overrepresentation of breast cancer (BC). Recently, functional assays have gained importance among the criteria used to predict the pathogenicity of hereditary breast and ovarian cancer (HBOC) risk-gene variants. Experimental assays scoring p53 functions in transcription and growth control have contributed to variant classification, yet a significant fraction of TP53 variants remain of unknown significance (VUS). To understand whether non-canonical functions of p53 in the fidelity control of DNA replication may aid variant classification, we subjected 23 TP53 VUS and 20 control variants identified in the German Consortium for HBOC (GC-HBOC) to assays that monitor nascent DNA synthesis and recombination-mediated bypass of replication barriers. Our results reveal a clear functional separation between benign (B)/likely benign (LB) and pathogenic (P)/likely pathogenic (LP) variants in recombination measurements, with B/LB variants associated with high recombination frequencies and P/LP variants with low recombination frequencies. Importantly, 8/23 VUS exhibited activities within the B/LB or P/LP ranges and therefore emerge as candidates for revised classification. Variant-specific recombination activities showed significant correlations with functional scores from four earlier studies systematically analyzing canonical p53 functions. Differently, in DNA fiber spreading assays B/LB and P/LP variants showed a more heterogeneous pattern and thus did not consistently recapitulate replication slow-down and acceleration observed in the presence and absence of p53, respectively. Structural modeling of separation-of-function (SOF) variants in transcription and recombination indicates varying effects on protein stability and the conformation of surface-exposed regions, affecting for example, the flexibility of Loop 1 (L1). Intriguingly, individual SOF variants suggest that loss-of-function (LOF) in recombination may drive BC, underscoring the predictive power of this assay for low-penetrance TP53 variants.

The cortical motor network excitatory-inhibitory (E/I) imbalance contributes to several neurodegenerative movement disorders. Spinal Muscular Atrophy (SMA) is a neuromuscular disease due to the lack of Survival Motor Neuron (SMN) protein, characterized by lower motor neuron (MN) degeneration and muscle atrophy. However, evidence shows that SMA patients display motor cortex abnormalities correlating with disease severity, suggesting altered maturation and maladaptive plasticity potentially contributing to upper MN vulnerability. This raises questions about cortical involvement and highlights the need for preclinical studies to clarify underlying mechanisms, given the limited accessibility of early-stage, untreated brain tissue from SMA patients. In agreement, our previous work in SMA mice revealed upper MN vulnerability, indicating SMA pathogenesis is far more complex than classically conceived. Here, by employing a combination of imaging, molecular techniques, and electrophysiological characterization of cortical inhibitory neurotransmission, we dissected GABAergic signalling, metabolism, and interneuron function in the sensorimotor cortex and primary neuron-astrocyte co-cultures of a severe SMA mouse model. Additionally, we conducted bioinformatic analyses and biochemical assays to assess age-dependent modulation of neurotransmitter pathways and quantify key metabolites across different stages of the disease, with the overall aim of evaluating correlations between GABA levels, its precursor glutamine, the expression of synthetic enzymes (GAD65/67), and the density of Parvalbumin-positive interneurons with SMN deficiency. We unveiled a significant association between SMN deficiency and impaired density, morphology and signalling of GABAergic Parvalbumin positive interneurons in the sensorimotor cortex of late-stage SMA mice, suggesting E/I imbalance and possibly contributing to shape upper MN vulnerability. We also highlighted the pivotal role of SMN, as involved in pre-mRNA splicing, in its impact on neuronal-astrocyte interactions regulating GABA metabolism, release and reuptake. These findings underscore a role for altered motor cortical GABAergic neurotransmission in SMA progression and offer a new key perspective to achieving novel, comprehensive therapeutic approaches.