Cell Death Discovery

Reversing the effects of ceramide imbalance via anti-ceramide immunotherapy is an effective therapy for diabetic retinopathy
Zhou L, Li J, Fu C and Chu WK
Folic acid prevents inner hair cell degeneration via genomic stability
Cai R, Ma X, Lu J, Liu H, Wang M, Wang Z, Xi Q, Wu H, Zhang Z and Liu H
Damage to inner hair cells (IHCs) is a leading cause of hearing loss, typically initiating at the base region of the basilar membrane. However, the mechanisms and preventative strategies for IHC damage remain to be elucidated. This study revealed that IHCs in the low-frequency region exhibit a significantly faster calcium clearance rate than high-frequency IHCs. This difference is associated with different PMCA1 expression. We then generated an IHC-specific Pmca1 knockout mouse model (Pmca1 CKO) exhibiting profound hearing loss and IHC death. Using single-cell RNA-seq analysis, we found that the differentially expressed genes (DEGs) were related to tetrahydrofolate biosynthesis, DNA damage, and DNA repair dysfunction. We therefore treated Pmca1 CKO mice with folic acid and found that it protected IHCs by reducing γ-H2A.X levels. In addition, we found that folic acid protected IHCs from noise-induced damage. Overall, our findings suggest that disrupted calcium homeostasis plays a role in IHC damage and that folic acid may be a promising therapeutic agent for protecting hair cells.
Exploring p53 isoforms: unraveling heterogeneous p53 tumor suppressor functionality in uveal melanoma
Bartolomei L, Ciribilli Y, Brugnara S, Reggiani F, Moretta GM, Petito M, Marcaccini E, Ambrosio M, Mosci C, Pfeffer U, Amaro A, Monti P and Bisio A
Uveal melanoma (UM) is the most common intraocular tumor, and despite being rare, it accounts for nearly 13% of melanoma-related deaths. Indeed, patients with metastatic disease have typically survival rates of less than one year, with little improvement over the past few decades. Although TP53 mutations are uncommon in UM, recent findings highlight a dysfunctional p53 pathway in this cancer. Given its crucial role in mediating DNA damage responses, we analyzed the p53 protein functionality and downstream target activation in a panel of UM cell lines in response to standard-of-care treatments (i.e., cisplatin and proton-beam irradiation). Although most of the analyzed cells retained a wild-type p53, we observed a wide range of p53 protein stabilization and targets' activation. Recently, p53 isoforms have been recognized as modifiers of p53 activity, and their biology and functions depend on cellular context. We observed that UM cells express a broad spectrum of p53 isoforms, including Δ160p53α and Δ133p53β and the longer variants Δ40p53β and p53β. Interestingly, the down-regulation of the short p53 isoforms (Δ133/Δ160) revealed their contribution to promoting cell growth and in mitigating cell death triggered by standard-of-care therapies. Moreover, we verified the wild-type p53 status in a panel of 32 UM cases and analyzed the expression levels of p53 isoforms. Our results indicated a correlation between higher expression levels of Δ40p53α or Δ133p53γ isoforms and the development of more aggressive cancers. Our findings suggest that shorter p53 isoforms can promote cancer aggressiveness and therapy resistance, thereby providing crucial insights into UM pathogenesis.
Aurora-A-mediated cytosolic localization of Maf1 promotes cell proliferation via regulating mitochondrial function in HCC
Yang SJ, Kuan YH, Ooi ZX, Lai HS, Wu HY, Liao PC, Lin YJ, Su CM, Lai MD and Hung LY
Maf1 is a well-known RNA polymerase III repressor and functions as a tumor suppressor due to its role in inhibiting tRNA synthesis. However, the role of Maf1 in hepatocellular carcinoma (HCC) remains unclear. This study identified Aurora-A as a novel upstream regulator of Maf1 in HCC. We demonstrated that Aurora-A interacts with the C domain of Maf1 and phosphorylates it at Threonine-212, leading to increased protein stability and cytosolic accumulation of Maf1. Importantly, the Aurora-A-enhanced cytosolic localization of Maf1 promotes mitochondrial dysfunction and glycolytic activity, ultimately driving HCC cell proliferation. In contrast, mutation of the Thr-212 site abolishes these effects, confirming its critical role. Significantly, elevated Maf-1 expression correlates with unfavorable clinical outcomes in HCC, particularly among patients with high Aurora-A expression. Furthermore, HCC cells with overexpressed Maf1 have heightened sensitivity to Aurora-A inhibitors, suggesting a potential therapeutic vulnerability. Our study uncovers a non-canonical, oncogenic role of Maf1 in HCC and highlights the Aurora-A-Maf1 axis as a promising target for personalized cancer therapy.
Blockade of mitochondrial components release by exosome pathway promotes the pathogenesis of Fuchs endothelial corneal dystrophy
Zhao C, Wang Q, Zhou Q, Wang Z, Yao S, Sang T, Duan H, Wu J, Zhong X, Sui X, Shi W and Wang T
Fuchs endothelial corneal dystrophy (FECD) is the leading indication of corneal transplantation worldwide and the focus of pathogenesis has been on the corneal endothelium. Instead of cellular analysis, we aimed to identify the protein changes of aqueous humor (AH) in patients with FECD and investigate in more detail the relationship between AH and corneal endothelium. We collected 13 AH samples of 7 early/middle stage FECD patients and 6 control patients during routine cataract surgery. The proteomes of AH were profiled with the 4D label-free quantitative tandem mass spectrometry. Among 1613 identified proteins, 44 proteins exhibited above two-fold upregulation in the AH of FECD patients than control patients. Gene ontology (GO) analysis showed the enrichment of mitochondrial components, which were further validated by ELISA of mitochondrial proteins SLC25A3, PC, and PARK7. Moreover, immunofluorescence staining and ultrastructural observation were conducted in clinical specimens, mouse corneal endothelium and cultured human corneal endothelial cells (HCECs). The mitochondrial protein TOM20 was reduced in the FECD corneal endothelium, accompanied by damaged mitochondrial ejection. We next isolated extracellular vesicles by ultracentrifugation from HCECs and revealed that the mitochondria copy numbers were significantly increased in UVA-irradiated cells. Inhibition of exosome biogenesis aggravated cell death and mitochondrial membrane potential impairment in FECD endothelial cells. Taken together, our results provided novel insights into the proteome characterization of the AH from FECD patients and offered new perspective to deepen the impaired mitochondrial quality control in the pathogenesis of FECD.
USP5 promotes glycolysis of fibroblast-like synoviocytes by stabilizing the METTL14/mA/GLUT1 axis in rheumatoid arthritis
Li X, Ling M, Wen Z, Jiang C and Tan X
Fibroblast-like synoviocytes (FLSs) contribute to the advancement of rheumatoid arthritis (RA) through enhanced metabolic reprogramming. This research focused on exploring the role and underlying mechanism of ubiquitin-specific protease 5 (USP5) in modulating the glycolysis and activation of RA-FLSs. Here, we identified that knockdown of USP5 in RA rats reduced synovial inflammation and glycolytic activity, as evidenced by decreased serum lactate levels and GLUT1 expression. In RA-FLSs, USP5 knockdown or treatment with 2-DG reduced cell proliferation, migration, invasion, cytokine production, and glycolysis, while increased apoptosis. Mechanistically, USP5 stabilized METTL14 by inhibiting its ubiquitination, while METTL14 enhanced the mA modification of GLUT1 mRNA, thereby increasing its expression. Furthermore, overexpression of METTL14 partially reversed the effects of USP5 knockdown on glycolysis and inflammatory activation in RA-FLSs. Additionally, knockdown of METTL14 inhibited RA-FLS glycolysis and inflammatory activation by downregulating GLUT1. Collectively, USP5 stabilized METTL14-mediated mA modification of GLUT1 by inhibiting the ubiquitination of METTL14, thereby enhancing glycolysis and inflammatory activation in RA-FLSs. These results suggest that the USP5/METTL14/GLUT1 axis could be a potential therapeutic target for RA.
CLC3 regulates V-ATPase to enhance lysosomal degradation and cisplatin resistance in cervical cancer cells
Chen C, Zhang F, Shen J, Zheng Q, Zhang Z, Lu S, Liu L, Zhu T, Du Y and Guan Y
Chemoresistance remains a major challenge in cervical cancer (CVC) treatment. Lysosomal function, mediated by V-ATPase, is critical in cancer progression and drug resistance. CLC3, a chloride channel that regulates lysosomal acidification, may contribute to chemoresistance by modulating V-ATPase activity. This study aims to investigate the role of CLC3 in modulating lysosomal function, chemoresistance, and tumorigenesis in CVC. CLC3 expression in CVC cell lines was assessed, and chemoresistance was evaluated using IC50 calculations for cisplatin, paclitaxel, and 5-FU. Effects of CLC3 downregulation or overexpression on lysosomal pH, autophagy, apoptosis, cell proliferation, cell cycle progression, and tumor stemness were analyzed. A general V-ATPase inhibitor was used to assess changes in lysosomal pH and protein degradation, while a2v-mAb was applied to investigate the interaction between CLC3 and specific V-ATPase subunits. In vivo, a mouse xenograft model was used to assess the effects of CLC3 modulation on tumor growth and response to chemoresistance. CLC3 was upregulated in CVC cells, reducing chemosensitivity. Overexpression of CLC3 enhanced cytosolic alkalinization, lysosomal acidification, and protein degradation while inhibiting autophagy and apoptosis independently. CLC3 promoted cell proliferation and tumor stemness via V-ATPase activity, particularly ATP6V1A. CLC3 knockdown combined with V-ATPase inhibition decreased proliferation and increased cisplatin sensitivity. In vivo, CLC3 knockdown with cisplatin reduced tumor volume and increased apoptosis, whereas overexpression promoted cisplatin resistance. CLC3 plays a pivotal role in chemoresistance and tumor progression in CVC by regulating lysosomal function via V-ATPase. Targeting CLC3 and its downstream pathways may provide novel therapeutic strategies to overcome chemoresistance.
GSDMD deficiency attenuates BPD by suppressing macrophage pyroptosis and promoting M2 polarization
Yang X, Wang X, Yang Y, Ma Y, Liu X, Mo D, Guo C and Han W
Bronchopulmonary dysplasia (BPD), a frequent complication in preterm infants receiving supplemental oxygen, is characterized by hyper-activation of macrophage inflammasomes, exuberant release of pro-inflammatory cytokines such as interleukin-1β (IL-1β), and Gasdermin D (GSDMD)-driven pyroptosis. However, the precise contribution of macrophage pyroptosis to BPD pathogenesis remains incompletely defined, and effective pharmacological interventions are still lacking. Using neonatal C57BL/6 wild-type (WT) and GSDMD-knockout (GSDMD) mice, we established a hyperoxia-induced BPD model (85% FiO₂, 14 days) and administered the GSDMD inhibitor disulfiram (50 mg kg⁻¹ intraperitoneally, once daily for 7 days). In vivo, we assessed lung histopathology, IL-1β levels, alveolarization, and vascular development; ex vivo, we isolated bone-marrow-derived macrophages (BMDMs) to quantify pyroptotic markers, M1/M2 polarization, and antibacterial capacity. GSDMD deletion or disulfiram treatment significantly attenuated macrophage and neutrophil infiltration, decreased pulmonary IL-1β concentrations, improved alveolar architecture and vascular density, and reduced overall cell death. BMDMs from GSDMD mice displayed diminished M1 polarization, enhanced bacterial killing, yet unaltered zymosan phagocytosis. Collectively, these findings identify GSDMD-mediated macrophage pyroptosis as a critical driver of BPD-related lung injury. Targeted GSDMD inhibition, whether genetic or pharmacologic, alleviates experimental BPD by down-regulating IL-1β and promoting alveolar development, thereby providing a promising therapeutic avenue for this devastating neonatal disorder.
Depletion of tryptophanyl-tRNA synthetase and tryptophan accumulation triggers p53-dependent apoptosis
Ali TA, Izadi M, Vazehan R, Al-Mansoob M and Pourkarimi E
Aminoacyl tRNA synthetases (AaRSs) are enzymes that play a role in maintaining translational fidelity by ensuring the accurate loading of amino acids to their cognate tRNAs. Mutations in the AaRSs are linked to diverse human diseases, including neurological disorders and various types of cancer. Among AaRSs, mutations in wars-1, a tryptophanyl tRNA synthetase, have been associated with cancer. Despite the extensive knowledge of WARS-1, there is no comprehensive understanding of its contribution to pathogenesis. In our previous study, we discovered the impact of WARS-1 on genomic integrity. We showed that WARS-1 depletion leads to a significant accumulation of free tryptophan (Trp), resulting in pronounced genomic instability, including the formation of chromatin bridges and micronuclei, and cell cycle arrest. In this study, we demonstrate that wars-1 knockdown induces apoptosis in the germline of C. elegans.
Bidirectional crosstalk between ER stress and lipid metabolism: From proteostasis to tumor adaptation
Wu Y, Luo H, Pan Z, Chen W and Bi L
Endoplasmic reticulum (ER) stress is a central adaptive response that maintains proteostasis under diverse metabolic and environmental challenges. In cancer, ER stress and lipid metabolism form a tightly coupled, bidirectional regulatory network that integrates protein quality control with lipid remodeling. Through the unfolded protein response (UPR), ER stress reprograms lipid synthesis, oxidation, and storage to sustain energy balance and membrane integrity. Conversely, dysregulated lipid accumulation disrupts ER homeostasis and amplifies stress signaling, creating a feedback loop between metabolic and proteostatic imbalance. Proteostasis systems, including the ubiquitin-proteasome system (UPS) and autophagy, cooperate with UPR signaling to fine-tune this adaptive balance and enhance tumor survival under stress. This review highlights the bidirectional crosstalk between ER stress and lipid metabolism from the perspective of proteostasis-driven tumor adaptation and summarizes emerging therapeutic strategies such as small-molecule modulators, natural products, and combination therapies that target this adaptive network to overcome drug resistance and improve cancer treatment.
USP25 attenuates the immunosuppressive tumor microenvironment via the deubiquitination of TAB2 in head and neck squamous cell carcinoma
Li X, Jia Y, Zhang R, Zheng X, Li C, Ma W, Han Y, Zheng C, Li Y, Shi Q, Hei H, Zhang S and Qin J
The role of deubiquitinating enzymes in the tumor immune microenvironment (TIME) remains understudied. Here, we sought to identify the mechanisms of USP25 modulation in the TIME of head and neck squamous cell carcinoma (HNSCC). Bioinformatics analysis was performed to screen differentially expressed novel deubiquitinases (DUBs) in HNSCC. The importance of USP25 in clinical practice was assessed in the TCGA dataset and tissue microarrays. Single-cell RNA-sequencing was applied to profile the TIME. The function of USP25 was determined through loss-of-function assays. Reduced expression of USP25 was associated with the malignant progression of HNSCC and further indicated poor prognosis. USP25 protein levels were positively correlated with CD8 T-cell infiltration in HNSCC tissue cohorts, suggesting its role in modulating the TIME. Concordantly, this study revealed a reduction in myeloid-derived suppressor cells (MDSCs), concomitant with increased numbers of cytotoxic T cells in tumors with high USP25 expression. Mechanistically, we revealed that USP25 binds to TAB2, removes K63-linked ubiquitination chains, and subsequently activates MAPK signaling and the secretion of IL-6, which increases MDSCs migration. Increased MSDCs in turn antagonized functional CD8 T cells in the TIME. Importantly, overexpression of USP25 increased anti-PD1 therapeutic efficacy in HNSCC in vivo. These results underscore the critical role and mechanism of USP25 in modulating the TIME in HNSCC, suggesting its potential as a therapeutic target in immune checkpoint blockade therapy.
Hypoxia-induced USP13 expression drives ferroptosis resistance and tumor immune evasion in hepatocellular carcinoma through the stabilization of ACLY
Hu K, Li J, Chen K, Mi X, Pan Y, Tang J, Cao J and Zhong X
Hepatocellular carcinoma (HCC) is an aggressive liver cancer with high recurrence and poor prognosis. This study aims to explore USP13's role in HCC progression and assess its potential as a therapeutic target to induce ferroptosis and enhance immune response. HCC patient-derived organoids (PDOs), HCC cell lines and animal models were utilized to evaluate the anti-cancer responses of USP13 inhibition. We analyzed the correlation of USP13 expression and immune cell infiltration using single-cell RNA sequencing, flow cytometry analysis. A USP13 inhibitor, 2-Methoxyestradiol (2-Met), was used to evaluate its therapeutic efficacy. USP13 was found to be highly expressed in HCC tissues and was correlated with poor prognosis. Single-cell RNA sequencing analysis indicated that high expression of USP13 in HCC cells was associated with decreased enrichment of CD8 + T cells in the tumor microenvironment (TME). Targeting USP13 reduced HCC cell proliferation, stemness, and cholesterol metabolism while promoting ferroptosis and enhancing T cell-mediated cytotoxicity. Mechanistically, USP13 stabilized ACLY via inhibiting the K48-specific poly-ubiquitination process on ACLY protein at the K726 site. Under hypoxia condition, HIF-1α upregulates the transcription of USP13 by binding to its promoter region, which stabilizes ACLY protein. Overall, this research reveals that hypoxia-induced USP13 expression drives ferroptosis resistance and tumor immune evasion in hepatocellular carcinoma through the stabilization of ACLY. Pharmacological inhibition or knockdown of USP13 impedes HCC progression, induces ferroptosis, and enhances T cell-mediated cytotoxic effects. These results highlight that USP13 could be a promising therapeutic target for HCC.
O-GlcNAcylation in novel regulated cell death: ferroptosis, pyroptosis, and necroptosis
Wang YZ, Zhao HY, Nyima T and Ma Z
GlcNAcylation, a dynamic post-translational modification involving the addition of N-acetylglucosamine to serine and threonine residues, has emerged as a key regulatory factor in cellular metabolism and signaling. Ferroptosis, pyroptosis, and necroptosis are newly discovered forms of regulated cell death that play crucial roles in various physiological and pathological processes, including cancer development, neurodegeneration, and inflammation. This review aims to summarize the functions of O-GlcNAcylation in modulating these distinct cell death pathways, with a focus on their implications in disease mechanisms and potential therapeutic applications. We summarize the mechanisms by which O-GlcNAcylation modulates ferroptosis, pyroptosis, and necroptosis, and explore the potential of targeting O-GlcNAcylation as a promising therapeutic strategy for diseases characterized by dysregulated cell death.
Hypomethylation-mediated upregulation of PHOX1 promotes gastric cancer progression via transactivation of NGFR
Li Y, Liu W, Zheng L, Zhu G, Qian X, Zeng R, Xu Y, Huang W, Huang Y and Zhang Q
Gastric cancer (GC) remains a leading cause of global cancer-related mortality with limited therapeutic options, and its molecular mechanisms are incompletely understood. Through integrative analysis of TCGA and GEO datasets, coupled with clinical cohort validation, we identified frequent overexpression of the transcription factor PHOX1 in GC tissues, which correlated significantly with advanced T/M stages and poor patient survival. We demonstrated that PHOX1 promoter hypomethylation, particularly at the CpG site cg04123776, drives its overexpression in GC. Functional assays revealed that overexpression of PHOX1 enhanced GC cell proliferation, migration, and invasion in vitro, while knockdown of PHOX1 inhibited these malignant behaviors. Additionally, orthotopic xenograft models confirmed its pro-metastatic role in promoting liver metastasis of GC cells. Mechanistically, RNA sequencing, chromatin immunoprecipitation assays, and luciferase reporter assays demonstrated that PHOX1 directly activated Nerve Growth Factor Receptor (NGFR) transcription. Rescue experiments with siRNA against NGFR and an ERK1/2 inhibitor further established that PHOX1 drove malignant phenotypes via NGFR and downstream ERK1/2 signaling. In conclusion, our study defines PHOX1 as a methylation-sensitive oncogene in GC, orchestrating tumor progression through transcriptional activation of NGFR, and the PHOX1-NGFR-ERK1/2 axis may serve as a therapeutic target for metastatic GC.
Sibiriline, a novel dual inhibitor of necroptosis and ferroptosis, prevents RIPK1 kinase activity and (phospho)lipid peroxidation as a potential therapeutic strategy
Delehouzé C, Mallais M, Comte A, Lucas R, Baratte B, Bélal S, Autret A, Py N, Steinschneider R, Adoux L, Saintpierre B, Letourneur F, Robert T, Cougoule C, Bomfim C, Planès R, Péricat D, Bulinski JC, Dimanche-Boitrel MT, Goekjian P, Meunier E, Rousselot M, Pratt DA and Bach S
In the past two decades, various non-apoptotic pathways of regulated cell death have been identified; a small subset of these, including necroptosis and ferroptosis, manifests the phenotypic features of necrotic death. These two regulated necroses are being extensively studied because of their putative roles in severe acute and chronic pathologies. Moreover, as these regulated necrotic pathways are coactivated in a number of common pathologies, the development of multi-target directed ligands (that is, the use of a polypharmacological strategy) is a path-breaking avenue of research. In this study, we determined that the 7-azaindole derivative, sibiriline, inhibited both RIPK1-driven necroptosis (induced by Tumor Necrosis Factor-α) and ferroptosis (triggered by various classes of ferroptosis inducers), with ECs against each in the µM range. We next performed a combined large-scale transcriptomic study in order to determine the molecular mechanisms of action of sibiriline. We identified the stress response protein heme oxygenase-1 (HMOX1) as the main biomarker of ferroptosis inhibition by sibiriline. We hypothesized that this compound reacts as an antioxidant to block ferroptosis; indeed, we found that sibiriline inhibits lipid peroxidation by trapping phospholipid-derived peroxyl radicals as a radical-trapping antioxidant (RTA). Taken together, these results show that sibiriline is a new dual inhibitor of necroptosis and ferroptosis cell death pathways; it works by inhibition of both RIPK1 kinase and (phospho)lipid peroxidation. We also demonstrate the in vitro efficacy of sibiriline to inhibit cell death in cell-based models of Parkinson's disease and cystic fibrosis. These findings shed light on the high therapeutic potency of RIPK1 inhibitors with RTA activity.
Inhibition of TBK1/IKKε mediated RIPK1 phosphorylation sensitizes tumors to immune cell killing
Piskopou A, Vredevoogd DW, Kong X, Peeper DS, Altelaar M and Stecker KE
Resistance to immune cell-mediated cytotoxicity poses a significant challenge in cancer therapy, compromising the efficacy of immunotherapeutic approaches such as immune checkpoint blockade (ICB) treatment. To enhance therapy outcomes, it is crucial to identify interventions that can synergize with ICB therapy to overcome tumor resistance. Therefore, we need to define the cellular mechanisms that sensitize tumors to cytotoxic T cells. CD8 T cells rely on cytokines such as TNF to carry out their cytotoxicity against tumors, and recent findings link select tumor mutations in the TNF pathway to increased T cell killing, in a manner dependent on RIPK1 kinase. Here, we demonstrate that sensitized tumor cells fail to initiate inhibitory RIPK1 phosphorylation at site S25 upon T cell attack, thereby foregoing a pro-survival checkpoint early in TNF signal transduction. Consequently, tumor cells experiencing a loss of TNF-induced RIPK1 S25 phosphorylation exhibit increased RIPK1 activation and fail to recruit non-canonical IKK kinases (TBK1 and IKKε) to the TNFR1 complex. Functional knockouts of TBK1 and IKKε in melanoma cells result in heightened sensitivity not only in CD8 T cell but also in Natural Killer cell attacks. Our findings indicate that preventing TBK1 and IKKε recruitment to the TNF signaling complex, thereby blocking RIPK1 pro-survival phosphorylation and promoting direct RIPK1 activation, is a tractable strategy to increase tumor sensitivity to immune cell killing and has the potential to benefit current immunotherapy interventions.
The expression, regulation, and function of human endogenous retroviruses in genitourinary cancers
Ma W, Ji C, Abudushataer A, Liu N, Xu T, Zhao K, Qian Y, Tuerxun P, Jiang X, Xiong Z, Wang M, Jia R, Xu Z, Li Y and Ge YZ
Human endogenous retroviruses (HERVs), constituting approximately 8% of the human genome, represent genomic remnants of ancestral retroviral infections that colonized the germline through evolutionary processes. While most HERVs remain epigenetically silenced, their reactivation through environmental stimuli or epigenetic dysregulation enables participation in oncogenesis via viral mimicry, immunomodulation, and insertional mutagenesis. Substantial evidence now implicates aberrant HERVs activity across urologic malignancies-including prostate cancer, renal cell carcinoma (RCC), bladder cancer, and testicular germ cell tumors-where cancer-type-specific mechanisms drive tumor development and progression. These encompass androgen-responsive HERV-K activation in prostate malignancies, hypoxia-inducible factor-mediated ERV immunogenicity in RCC, HERV-derived microRNA silencing of tumor suppressors in bladder cancer, and DNA hypomethylation-associated HERV expression in testicular germ cell tumors. This review synthesizes fundamental HERV biology with recent advances in their diagnostic and therapeutic applications for urologic neoplasms. Key clinical translations include ERV-based stratification models predicting immune checkpoint inhibitor response in metastatic RCC, HERV-E-targeted adoptive T cell therapies, and noncoding RNA biomarkers for early bladder cancer detection. We further discuss unresolved mechanistic paradoxes such as contradictory prognostic associations between HERV superfamily expression and PBRM1 inactivation in RCC, concluding with priorities for future research: validating HERV-derived neoantigens in immunotherapy platforms, optimizing epigenetic priming strategies to enhance viral mimicry effects, and establishing standardized HERV signatures as clinical biomarkers through multi-institutional cohorts.
N6-methyladenosine: a key regulator in ocular disease mechanisms and treatment
Lin Y, Zeng L, Zhang Y, Liu Y, Wang J, Xu C, Liu L, Yu P, Han Z, Li S and Yang Q
N6-methyladenosine (m6A), a pivotal RNA modification, has garnered considerable attention in cell biology and disease research. m6A plays a critical role in the regulation of gene expression, cell proliferation, differentiation, and apoptosis, with particular relevance to the onset and progression of ocular diseases. This review examines the current research on m6A in ocular diseases, including keratitis, cataracts, glaucoma, retinopathy, thyroid ophthalmopathy, and ocular tumors, highlighting its functional significance and potential mechanisms in these conditions. Recent studies suggest that m6A modification influences cellular fate and pathophysiological processes by modulating the expression of key genes. However, a deeper understanding of the precise mechanisms underlying m6A action in ocular diseases is still needed. By synthesizing the existing literature, this review seeks to offer novel insights and identify potential therapeutic targets, thereby advancing clinical applications for ocular disease treatment.
PPA1 promotes oxidative phosphorylation and malignant progression of colorectal cancer under glucose restriction via AMPK/ULK1/FUNDC1-mediated mitophagy
Chen Y, Deng Q, Chen Z, Yang L, Li X and Fu Z
Metabolic reprogramming is a hallmark of colorectal cancer (CRC). Pyrophosphatase 1(PPA1), an energy-metabolizing enzyme, has been observed to be upregulated in multiple cancers and implicated in tumorigenesis and progression. However, its specific role in metabolic rewiring of CRC and the underlying molecular mechanisms remain poorly understood. Our study revealed that PPA1 is highly expressed in CRC epithelial cells and is significantly associated with advanced tumor size, lymph node status, TNM stage, and reduced overall survival in patients. Knockdown of PPA1 suppressed CRC tumorigenesis and metastasis both in vitro and in vivo. Under glucose-restricted conditions, PPA1 depletion impaired OXPHOS in CRC cells, leading to reduced oxygen consumption, decreased ATP production, elevated mitochondrial ROS levels, and decline in mitochondrial membrane potential. Mechanistically, PPA1 promotes phosphorylation of AMPK at Thr172, thereby facilitating phosphorylation of ULK1 at Ser467 and Ser555, and subsequently enhancing FUNDC1 phosphorylation at Ser17. This phosphorylation cascade initiates mitophagy to sustain OXPHOS metabolic activity, thereby driving CRC malignant progression. In summary, PPA1 sustains OXPHOS and drives malignant progression in CRC under glucose restriction by promoting AMPK/ULK1/FUNDC1-mediated mitophagy.
Retinal alterations resemble brain pathology in a rat model of Parkinson's disease induced by intranigral infusion of α-synuclein oligomers
Burgaletto C, Cantone AF, Palmas MF, Platania CBM, Di Benedetto G, Gaudio G, Barbagallo C, Ragusa M, Bucolo C, Vicario N, Carboni E, De Simone A, Bernardini R, Carta AR and Cantarella G
Parkinson's disease (PD) is a debilitating neurodegenerative synucleinopathy, characterized by dopaminergic degeneration, pathological deposition of alpha-synuclein (α-Syn), and neuroinflammation in both motor regions of the midbrain and non-motor areas of the cortex. Despite its motor-centric characterization, visual disturbances such as hallucinations, diplopia, altered contrast sensitivity and retinal abnormalities are well-documented non-motor changes of PD. While this evidence points to neuropathological processes in PD that extend beyond the brain, the neuropathological basis of retinal dysfunction and the role of α-Syn remain poorly investigated. Given the central neuropathological role of α-Syn in the PD brain, we assessed whether the retina is affected in a translational rat model of PD based on the intranigral bilateral infusion of toxic oligomers of human α-Synuclein (H-α-SynOs). Rats were stereotaxically injected with H-α-SynOs or PBS (Vehicle) into the substantia nigra pars compacta (SNpc) and sacrificed 3 months post-infusion. Thereafter, several retinal tissue pathological parameters, along with the expression patterns of selected miRNAs and inflammatory markers, were assessed. The retina of rats infused with H-α-SynOs exhibited high levels of phosphorylated-α-Syn (p-α-Syn), along with a significant decrease of tyrosine hydroxylase (TH) expression, reflecting dopaminergic neuron disfunction. Analysis of PD-associated miRNAs in the retina also revealed heightened levels of miR-384-5p, which inversely correlated with the expression of its predicted molecular target, SIRT1, in rats infused with H-α-SynOs. Consistently, H-α-SynOs infusion induced a widespread activation of retinal astrocytes and microglial markers, associated with a heightened proinflammatory cytokine signaling downstream of TLR4/NFκB. Collectively, our data reveal that H-α-SynOs extend their neuropathological effects to retinal damage, reinforcing our rodent model ability to recapitulate PD pathology in both brain and retina. This study underscores the robustness of this preclinical model and its value as translational system for testing proactive interventions targeting PD-related pathology.
Epithelial pyroptosis-induced TREM1 macrophages activate Th17 cells to accelerate oral mucosal inflammation
Shang Q, Wang Z, Peng J, Yang D, Li W, Huang X, Qing M, Cheng H, Liu J, Dan H, Zeng X, Zhou Y, Zhang D, Xu H and Chen Q
Chronic inflammation of the oral mucosa could affect daily living and even threaten systemic health. Unlike periodontitis, oral lichen planus, a common oral chronic inflammatory disease, has diverse clinical manifestations and can progress to malignancy. Hence, this study aimed to investigate the mechanism of oral chronic inflammation using single-cell RNA sequencing (scRNA-seq), spatial transcriptome, a large clinical follow-up cohort with bulk RNA sequencing, cytological experiments, and multiplex immunohistochemistry. We found that epithelial pyroptosis-induced triggering receptor expressed on myeloid cell-1 (TREM1) macrophages activated pathogenic T helper cell 17 via interleukin-1β, to spur the inflammatory development of oral mucosal epithelium. Besides, we established a spatiotemporal interactional online database, Oral-Gut Axis Mucosal Immune Atlas (ORGUAMIA), to uncover the extensive pro-inflammatory role of epithelial pyroptosis-induced TREM1 macrophages in chronic digestive tract disorders. In summary, this study highlights the role of epithelial pyroptosis-induced TREM1 macrophages accelerating mucosal epithelial inflammation and offers ORGUAMIA as a tool for researchers using scRNA-seq and spatial transcriptome without technological barriers.