Autophagic clearance of polyQ proteins mediated by ubiquitin-Atg8 adaptors of the conserved CUET protein family.

Selective ubiquitin-dependent autophagy plays a pivotal role in the elimination of protein aggregates, assemblies, or organelles and counteracts the cytotoxicity of proteins linked to neurodegenerative diseases. Following substrate ubiquitylation, the cargo is delivered to autophagosomes involving adaptors like human p62 that bind ubiquitin and the autophagosomal ubiquitin-like protein Atg8/LC3; however, whether similar pathways exist in lower eukaryotes remained unclear. Here, we identify by a screen in yeast a new class of ubiquitin-Atg8 adaptors termed CUET proteins, comprising the ubiquitin-binding CUE-domain protein Cue5 from yeast and its human homolog Tollip. Cue5 collaborates with Rsp5 ubiquitin ligase, and the corresponding yeast mutants accumulate aggregation-prone proteins and are vulnerable to polyQ protein expression. Similarly, Tollip depletion causes cytotoxicity toward polyQ proteins, whereas Tollip overexpression clears human cells from Huntington's disease-linked polyQ proteins by autophagy. We thus propose that CUET proteins play a critical and ancient role in autophagic clearance of cytotoxic protein aggregates.

Pharmacological induction of autophagy reduces inflammation in macrophages by degrading immunoproteasome subunits.

Defective autophagy is linked to proinflammatory diseases. However, the mechanisms by which autophagy limits inflammation remain elusive. Here, we found that the pan-FGFR inhibitor LY2874455 efficiently activated autophagy and suppressed expression of proinflammatory factors in macrophages stimulated by lipopolysaccharide (LPS). Multiplex proteomic profiling identified the immunoproteasome, which is a specific isoform of the 20s constitutive proteasome, as a substrate that is degraded by selective autophagy. SQSTM1/p62 was found to be a selective autophagy-related receptor that mediated this degradation. Autophagy deficiency or p62 knockdown blocked the effects of LY2874455, leading to the accumulation of immunoproteasomes and increases in inflammatory reactions. Expression of proinflammatory factors in autophagy-deficient macrophages could be reversed by immunoproteasome inhibitors, confirming the pivotal role of immunoproteasome turnover in the autophagy-mediated suppression on the expression of proinflammatory factors. In mice, LY2874455 protected against LPS-induced acute lung injury and dextran sulfate sodium (DSS)-induced colitis and caused low levels of proinflammatory cytokines and immunoproteasomes. These findings suggested that selective autophagy of the immunoproteasome was a key regulator of signaling via the innate immune system.

ALS-linked C9orf72-SMCR8 complex is a negative regulator of primary ciliogenesis.

Massive GGGGCC (G4C2) repeat expansion in C9orf72 and the resulting loss of C9orf72 function are the key features of ~50% of inherited amyotrophic lateral sclerosis and frontotemporal dementia cases. However, the biological function of C9orf72 remains unclear. We previously found that C9orf72 can form a stable GTPase activating protein (GAP) complex with SMCR8 (Smith-Magenis chromosome region 8). Herein, we report that the C9orf72-SMCR8 complex is a major negative regulator of primary ciliogenesis, abnormalities in which lead to ciliopathies. Mechanistically, the C9orf72-SMCR8 complex suppresses the primary cilium as a RAB8A GAP. Moreover, based on biochemical analysis, we found that C9orf72 is the RAB8A binding subunit and that SMCR8 is the GAP subunit in the complex. We further found that the C9orf72-SMCR8 complex suppressed the primary cilium in multiple tissues from mice, including but not limited to the brain, kidney, and spleen. Importantly, cells with C9orf72 or SMCR8 knocked out were more sensitive to hedgehog signaling. These results reveal the unexpected impact of C9orf72 on primary ciliogenesis and elucidate the pathogenesis of diseases caused by the loss of C9orf72 function.

PAK inhibitor FRAX486 decreases the metastatic potential of triple-negative breast cancer cells by blocking autophagy.

BACKGROUND: Triple-negative breast cancer (TNBC) is a unique breast cancer subtype with a high risk of metastasis and recurrence and a poor prognosis. Epithelial-mesenchymal transition (EMT) endows epithelial cells with the ability to move to distant sites, which is essential for the metastasis of TNBC to organs, including the lung. Autophagy, an intracellular degradation process that involves formation of double-layered lipid autophagosomes that transport cytosolic cargoes into lysosomes via autophagosome-lysosome fusion, is involved in various diseases, including cancer and neurodegenerative, metabolic, cardiovascular, and infectious diseases. The relationship between autophagy and cancer has become relatively clear. However, research on pharmacological drugs that block cancer EMT by targeting autophagy is still in the initial stages. Therefore, the re-evaluation of old drugs for their potential in blocking both autophagy and EMT was conducted. METHODS: More than 2000 small molecule chemicals were screened for dual autophagy/EMT inhibitors, and FRAX486 was identified as the best candidate inhibitor of autophagy/EMT. The functions of FRAX486 in TNBC metastasis were detected by CCK-8, migration and wound healing assays. The effects of FRAX486 on autophagy and its target PAK2 were determined by immunoblotting, immunofluorescence, immunoprecipitation analysis and transmission electron microscopy. The findings were validated in mouse models. RESULTS: Here, we report that FRAX486, a potent P21-activated kinase 2 (PAK2) inhibitor, facilitates TNBC suppression both in vitro and in vivo by blocking autophagy. Mechanistically, FRAX486 inhibits autophagy in TNBC cells by targeting PAK2, leading to the ubiquitination and proteasomal degradation of STX17, which mediates autophagosome-lysosome fusion. The inhibition of autophagy by FRAX486 causes upregulation of the epithelial marker protein E-cadherin and thus suppresses the migration and metastasis of TNBC cells. CONCLUSIONS: The effects of FRAX486 on TNBC metastasis suppression were verified to be dependent on PAK2 and autophagy inhibition. Together, our results provide a molecular basis for the application of FRAX486 as a potential treatment for inhibiting the metastasis of TNBC.

The RNA polymerase II subunit Rpb9 activates ATG1 transcription and autophagy.

Macroautophagy/autophagy is a conserved process in eukaryotic cells that mediates the degradation and recycling of intracellular substrates. Proteins encoded by autophagy-related (ATG) genes are essentially involved in the autophagy process and must be tightly regulated in response to various circumstances, such as nutrient-rich and starvation conditions. However, crucial transcriptional activators of ATG genes have remained obscure. Here, we identify the RNA polymerase II subunit Rpb9 as an essential regulator of autophagy by a high-throughput screen of a Saccharomyces cerevisiae gene knockout library. Rpb9 plays a crucial and specific role in upregulating ATG1 transcription, and its deficiency decreases autophagic activities. Rpb9 promotes ATG1 transcription by binding to its promoter region, which is mediated by Gcn4. Furthermore, the function of Rpb9 in autophagy and its regulation of ATG1/ULK1 transcription are conserved in mammalian cells. Together, our results indicate that Rpb9 specifically activates ATG1 transcription and thus positively regulates the autophagy process.

Risk factors for the development of severe breast cancer-related lymphedema: a retrospective cohort study.

BACKGROUND: Severe lymphedema presents a challenge in terms of treatment due to the significant formation of scar tissue that accompanies it. The aim of this study was to identify intraoperative and preoperative risk factors of severe lymphedema and to develop a nomogram for estimating the risk of severe lymphedema within 3 years of surgery. METHOD: Data was collected from a retrospective cohort of 326 patients with BCRL at the Zhejiang Cancer Hospital from November 2015 to November 2018. Univariate and multivariate logistic regression analysis was conducted to identify predictive indicators of severe lymphedema. A nomogram was developed to further improve the clinical applicability. RESULTS: In the retrospective cohort, the ratio of severe/non-severe lymphedema within 3 years of surgery was 1:3. Independent risk factors for severe lymphedema were determined to be age, positive lymph nodes, interpectoral (Rotter's) lymph nodes (IPNs) dissection, and educational level. IPNs dissection was found to contribute greatly to the development of severe lymphedema with a higher odds ratio (7.76; 95% CI: 3.87-15.54) than other risk factors. A nomogram was developed by integrating age, positive lymph nodes, IPNs dissection, and educational level, which yielded a C-index of 0.810 and 0.681 in the training and validation cohort, respectively. This suggested a moderate performance of the nomogram in predicting the risk of severe lymphedema within 3 years of surgery. The cut-off values of the low-, medium- and high-risk probabilities were 0.0876 and 0.3498, and the severe lymphedema exhibited a significantly higher risk probability as compared with the non-severe lymphedema. CONCLUSION: This study identified the risk factors of severe lymphedema and highlighted the substantial contribution of IPNs dissection to the severity of lymphedema.

Cryo-EM structure of C9ORF72-SMCR8-WDR41 reveals the role as a GAP for Rab8a and Rab11a.

A massive intronic hexanucleotide repeat (GGGGCC) expansion in C9ORF72 is a genetic origin of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recently, C9ORF72, together with SMCR8 and WDR41, has been shown to regulate autophagy and function as Rab GEF. However, the precise function of C9ORF72 remains unclear. Here, we report the cryogenic electron microscopy (cryo-EM) structure of the human C9ORF72-SMCR8-WDR41 complex at a resolution of 3.2 Å. The structure reveals the dimeric assembly of a heterotrimer of C9ORF72-SMCR8-WDR41. Notably, the C-terminal tail of C9ORF72 and the DENN domain of SMCR8 play critical roles in the dimerization of the two protomers of the C9ORF72-SMCR8-WDR41 complex. In the protomer, C9ORF72 and WDR41 are joined by SMCR8 without direct interaction. WDR41 binds to the DENN domain of SMCR8 by the C-terminal helix. Interestingly, the prominent structural feature of C9ORF72-SMCR8 resembles that of the FLNC-FNIP2 complex, the GTPase activating protein (GAP) of RagC/D. Structural comparison and sequence alignment revealed that Arg147 of SMCR8 is conserved and corresponds to the arginine finger of FLCN, and biochemical analysis indicated that the Arg147 of SMCR8 is critical to the stimulatory effect of the C9ORF72-SMCR8 complex on Rab8a and Rab11a. Our study not only illustrates the basis of C9ORF72-SMCR8-WDR41 complex assembly but also reveals the GAP activity of the C9ORF72-SMCR8 complex.

The crystal structure of Atg18 reveals a new binding site for Atg2 in Saccharomyces cerevisiae.

Macroautophagy (hereafter referred to as autophagy) is a highly conserved catabolic eukaryotic pathway that is critical for stress responses and homeostasis. Atg18, one of the core proteins involved in autophagy, belongs to the PROPPIN family and is composed of seven WD40 repeats. Together with Atg2, Atg18 participates in the elongation of phagophores and the recycling of Atg9 in yeast. Despite extensive studies on the PROPPIN family, the structure of Atg18 from Saccharomyces cerevisiae has not been determined. Here, we report the structure of ScAtg18 at a resolution of 2.8 Å. Based on bioinformatics and structural analysis, we found that the 7AB loop of ScAtg18 is extended in Atg18, in comparison to other members of the PROPPIN family. Genetic analysis revealed that the 7AB loop of ScAtg18 is required for autophagy. Biochemical and biophysical experiments indicated that the 7AB loop of ScAtg18 is critical for interaction with ScAtg2 and the recruitment of ScAtg2 to the autophagy-initiating site. Collectively, our results show that the 7AB loop of ScAtg18 is a new binding site for Atg2 and is of functional importance to autophagy.

O-GlcNAcylation modulates HBV replication through regulating cellular autophagy at multiple levels.

O-GlcNAcylation is a form of posttranslational modification, and serves various functions, including modulation of location, stability, and activity for the modified proteins. O-linked-N-acetylglucosamine (O-GlcNAc) transferase (OGT) is an essential cellular enzyme that posttranslationally modifies the cellular proteins with O-GlcNAc moiety. Early studies reported that the decreased O-GlcNAcylation regulates cellular autophagy, a process relevant for hepatitis B virus replication (HBV) and assembly. Therefore, we addressed the question how O-GlcNAcylation regulates cellular autophagy and HBV replication. Inhibition of OGT activity with a small molecule inhibitor OSMI-1 or silencing OGT significantly enhanced HBV replication and HBsAg production in hepatoma cells and primary human hepatocytes (PHHs). Western blotting analysis showed that inhibition of O-GlcNAcylation-induced endoplasmic reticulum (ER) stress and cellular autophagy, two processes subsequently leading to enhanced HBV replication. Importantly, the numbers of autophagosomes and the levels of autophagic markers LC3-II and SQSTM1/p62 in hepatoma cells were elevated after inhibition of O-GlcNAcylation. Further analysis revealed that inhibition of O-GlcNAcylation blocked autophagosome-lysosome fusion and thereby prevented autophagic degradation of HBV virions and proteins. Moreover, OSMI-1 further promoted HBV replication by inducing autophagosome formation via inhibiting the O-GlcNAcylation of Akt and mTOR. In conclusion, decreased O-GlcNAcylation enhanced HBV replication through increasing autophagosome formation at multiple levels, including triggering ER-stress, Akt/mTOR inhibition, and blockade of autophagosome-lysosome fusion.

Screening for Genes Involved in Autophagy.

Autophagy is an important intracellular lysosomal degradation process in cells, which is highly conserved from yeast to mammals. The process of autophagy is roughly divided into the following key steps: the formation of a membrane structure called ISM (isolated membrane) after stimulation, the biogenesis and maturation of autophagosomes, and finally the degradation of autophagosomes. A number of proteins are required to function in the whole process of autophagy. Since the initial genetic screening in yeast cells, multiple genes that play pivotal roles in autophagy have been discovered. These molecules have been named ATG genes (AuTophaGy related genes). The screening for new key molecules involved in autophagy has greatly promoted the characterization of the mechanism of the autophagy machinery and provides multiple targets for the development of autophagy-based regulatory drugs.

Proteomics and Autophagy Research.

Autophagy is an evolutionarily conserved intracellular degradation process. Autophagy is closely involved in human health and diseases. In recent years, mass spectrometry-based proteomic methods have become important and powerful tools for autophagy studies. These types of techniques have been especially helpful to reveal the range of degradation substrates of autophagy through large-scale, unbiased analysis of cellular proteomes. At present, a variety of mass spectrometry-based proteomics methods have been successfully applied to autophagy research.

High-mobility group protein N2 induces autophagy by activating AMPK/ULK1 pathway and thereby boosts UPEC proliferation within bladder epithelial cells.

Urinary tract infection is one of the most common bacterial infections which is mainly caused by Escherichia coli (UPEC). Autophagy plays a key role in immune response to eliminate invading pathogens. Exploring the effect of autophagy on UPEC infection and the molecular mechanisms will be benefit for the treatment of urinary tract infection. High-mobility group protein N2 (HMGN2), a highly conserved nuclear protein and an antibacterial peptide, has been associated with bacterial infection induced immune response; however, whether this function is due to the regulation of autophagy remains unclear. In this study, we demonstrate for the first time that HMGN2 is upregulated in UPEC infection of bladder epithelial cell line 5637 (BEC 5637). Furthermore, HMGN2 enhances autophagy in BEC 5637 via activation of AMPK and ULK1, whereas UPEC suppresses autophagy. In addition, the enhanced autophagy activity by HMGN2 overexpression or rapamycin boosts the proliferation of UPEC J96 in BEC 5637. In summary, our data indicate that HMGN2 activates autophagy via AMPK/ULK1 pathway which can be utilized by UPEC J96 for their proliferation within bladder epithelial cells.

Autophagy Regulation of Bacterial Pathogen Invasion.

Autophagy pathway is highly conserved in all eukaryotic species and responsible for targeting of cytosol components, such as protein aggregates, damaged or unnecessary organelles, and intracellular bacterial pathogens for lysosome-dependent degradation. Besides severing as a catabolic process, autophagy pathway furthermore has been discovered to function pivotally in both innate and adaptive immune responses. At present, it has been well demonstrated that certain types of bacteria could be targeted by autophagy upon their invasion. However, several bacterial pathogens have developed strategies to evade this degradation and clearance. Here, we review the role and mechanism of autophagy in the regulation of bacteria invasion, which may facilitate the designing of clinical drugs for efficient and safe cure of infection diseases caused by toxic bacteria.

SCFFBXL¹5 regulates BMP signalling by directing the degradation of HECT-type ubiquitin ligase Smurf1.

Smad ubiquitination regulatory factor 1 (Smurf1), an homologous to E6AP C-terminus (HECT)-type E3 ubiquitin ligase, performs a crucial role in the regulation of the bone morphogenetic protein (BMP) signalling pathway in both embryonic development and bone remodelling. How the stability and activity of Smurf1 are negatively regulated remains largely unclear. Here, we report that F-box and LRR domain-containing protein 15 (FBXL15), an F-box protein of the FBXL family, forms an Skp1-Cullin1-F-box protein-Roc1 (SCF)(FBXL15) ubiquitin ligase complex and targets Smurf1 for ubiquitination and proteasomal degradation. FBXL15, through its leucine-rich repeat domain, specifically recognizes the large subdomain within the N-lobe of the Smurf1 HECT domain and promotes the ubiquitination of Smurf1 on K355 and K357 within the WW-HECT linker region. In this way, FBXL15 positively regulates BMP signalling in mammalian cells. Knockdown of fbxl15 expression in zebrafish embryos by specific antisense morpholinos causes embryonic dorsalization phenocoping BMP-deficient mutants. Injection of FBXL15 siRNAs into rat bone tissues leads to a significant loss of bone mass and decrease in bone mineral density. Collectively, our results demonstrate that Smurf1 stability is suppressed by SCF(FBXL15)-mediated ubiquitination and that FBXL15 is a key regulator of BMP signalling during embryonic development and adult bone formation.

The HECT type ubiquitin ligase NEDL2 is degraded by anaphase-promoting complex/cyclosome (APC/C)-Cdh1, and its tight regulation maintains the metaphase to anaphase transition.

NEDD4-like ubiquitin ligase 2 (NEDL2) is a HECT type ubiquitin ligase. NEDL2 enhances p73 transcriptional activity and degrades ATR kinase in lamin misexpressed cells. Compared with the important functions of other HECT type ubiquitin ligase, there is less study concerning the function and regulation of NEDL2. Using primary antibody immunoprecipitation and mass spectrometry, we identify a list of potential proteins that are putative NEDL2-interacting proteins. The candidate list contains many of mitotic proteins, especially including several subunits of anaphase-promoting complex/cyclosome (APC/C) and Cdh1, an activator of APC/C. Cdh1 can interact with NEDL2 in vivo and in vitro. Cdh1 recognizes one of the NEDL2 destruction boxes (R(740)GSL(743)) and targets it for degradation in an APC/C-dependent manner during mitotic exit. Overexpression of Cdh1 reduces the protein level of NEDL2, whereas knockdown of Cdh1 increases the protein level of NEDL2 but has no effect on the NEDL2 mRNA level. NEDL2 associates with mitotic spindles, and its protein level reaches a maximum in mitosis. The function of NEDL2 during mitosis is essential because NEDL2 depletion prolongs metaphase, and overexpression of NEDL2 induces chromosomal lagging. Elevated expression of NEDL2 protein and mRNA are both found in colon cancer and cervix cancer. We conclude that NEDL2 is a novel substrate of APC/C-Cdh1 as cells exit mitosis and functions as a regulator of the metaphase to anaphase transition. Its overexpression may contribute to tumorigenesis.

CKIP-1 couples Smurf1 ubiquitin ligase with Rpt6 subunit of proteasome to promote substrate degradation.

CKIP-1 is an activator of the Smurf1 ubiquitin ligase acting to promote the ubiquitylation of Smad5 and MEKK2. The mechanisms involved in the recognition and degradation of these substrates by the proteasome remain unclear. Here, we show that CKIP-1, through its leucine zipper, interacts directly with the Rpt6 ATPase of the 19S regulatory particle of the proteasome. CKIP-1 mediates the Smurf1-Rpt6 interaction and delivers the ubiquitylated substrates to the proteasome. Depletion of CKIP-1 reduces the degradation of Smurf1 and its substrates by Rpt6. These findings reveal an unexpected adaptor role of CKIP-1 in coupling the ubiquitin ligase and the proteasome.

Selective autophagy of the immunoproteasomes suppresses innate inflammation.

Immunoproteasomes are involved in various inflammatory diseases. Upon stimulation, standard constitutive proteasomes are partially replaced by newly formed immunoproteasomes that promote inflammatory responses. How the upregulated immunoproteasomes are cleared to constrain hyper-inflammation is unknown. Recently, our studies showed that the pan-FGFR inhibitor LY2874455 efficiently activates macroautophagy/autophagy in macrophages, leading to the degradation of the immunoproteasomes. Immunoproteasome subunits are ubiquitinated and recognized by the selective autophagy receptor SQSTM1/p62. LY2874455 suppresses inflammation induced by lipopolysaccharide both in vivo and in vitro through autophagic degradation of the immunoproteasomes. In summary, our work uncovers a mechanism of inflammation suppression by autophagy in macrophages.

Preoperative prediction of central lymph node metastasis in follicular variant of papillary thyroid carcinoma using clinical and ultrasound features.

Background: The most common metastatic site of follicular variant of papillary thyroid carcinoma (FVPTC) is the central lymph nodes, which may be associated with the prognosis and survival of patients. In the present study, we establish a combined model based on preoperative clinical and ultrasound (US) features of FVPTC to predict the risk of central lymph node metastasis (CLNM). Methods: From January 2013 to December 2022, 315 patients with FVPTC were enrolled and randomly divided into the training and validation cohorts in a ratio of 7:3. The independent risk factors for CLNM in FVPTC were analysed using univariate and multivariate logistic regression analyses. Then, three different models were established based on clinical and US data. Subsequently, a nomogram was constructed to predict CLNM. Its predictive effect was evaluated via receiver operating characteristic and calibration curve analyses. Results: Backward multivariate regression analysis revealed that age (P=0.001), thyroid peroxidase antibody (TPOAb) (P=0.11), diameter (P=0.047), irregular/lobulated margin (P=0.15), extrathyroidal extension (P=0.001), nodules with macrocalcifications (P=0.009), nodules with microcalcification (P=0.003) and Thyroid Imaging Reporting and Data System (ACR-TI-RADS) category 5 (P=0.33) were independent risk factors for CLNM in FVPTC. The areas under the curve of the matching nomogram in the training (N=221) and validation cohorts (N=94) were 0.841 [95% confidence interval (CI): 0.788-0.895] and 0.735 (95% CI: 0.621-0.872), respectively. Conclusions: Preoperative thyroid US provides useful features for prediction of CLNM. The nomogram constructed based on combining US and clinical features can better predict the risk of CLNM and may facilitate decision-making in clinical settings.

Molecular subtype identification and prognosis stratification based on lysosome-related genes in breast cancer.

Background: Lysosomes are known to have a significant impact on the development and recurrence of breast cancer. However, the association between lysosome-related genes (LRGs) and breast cancer remains unclear. This study aims to explore the potential role of LRGs in predicting the prognosis and treatment response of breast cancer. Methods: Breast cancer gene expression profile data and clinical information were downloaded from TCGA and GEO databases, and prognosis-related LRGs were screened for consensus clustering analysis. Lasso Cox regression analysis was used to construct risk features derived from LRGs, and immune cell infiltration, immune therapy response, drug sensitivity, and clinical pathological feature differences were evaluated for different molecular subtypes and risk groups. A nomogram based on risk features derived from LRGs was constructed and evaluated. Results: Our study identified 176 differentially expressed LRGs that are associated with breast cancer prognosis. Based on these genes, we divided breast cancer into two molecular subtypes with significant prognostic differences. We also found significant differences in immune cell infiltration between these subtypes. Furthermore, we constructed a prognostic risk model consisting of 7 LRGs, which effectively divides breast cancer patients into high-risk and low-risk groups. Patients in the low-risk group have better prognostic characteristics, respond better to immunotherapy, and have lower sensitivity to chemotherapy drugs, indicating that the low-risk group is more likely to benefit from immunotherapy and chemotherapy. Additionally, the risk score based on LRGs is significantly correlated with immune cell infiltration, including CD8 T cells and macrophages. This risk score model, along with age, chemotherapy, clinical stage, and N stage, is an independent prognostic factor for breast cancer. Finally, the nomogram composed of these factors has excellent performance in predicting overall survival of breast cancer. Conclusions: In conclusion, this study has constructed a novel LRG-derived breast cancer risk feature, which performs well in prognostic prediction when combined with clinical pathological features.

DNALI1 Promotes Neurodegeneration after Traumatic Brain Injury via Inhibition of Autophagosome-Lysosome Fusion.

Traumatic brain injury (TBI) leads to progressive neurodegeneration that may be caused by chronic traumatic encephalopathy (CTE). However, the precise mechanism remains unclear. Herein, the study identifies a crucial protein, axonemal dynein light intermediate polypeptide 1 (DNALI1), and elucidated its potential pathogenic role in post-TBI neurodegeneration. The DNALI1 gene is systematically screened through analyses of Aging, Dementia, and TBI studies, confirming its elevated expression both in vitro and in vivo. Moreover, it is observed that altered DNALI1 expression under normal conditions has no discernible effect. However, upon overexpression, DNALI1 inhibits autophagosome-lysosome fusion, reduces autophagic flux, and exacerbates cell death under pathological conditions. DNALI1 silencing significantly enhances autophagic flux and alleviates neurodegeneration in a CTE model. These findings highlight DNALI1 as a potential key target for preventing TBI-related neurodegeneration.