TNRC18 engages H3K9me3 to mediate silencing of endogenous retrotransposons

Pharmacologic degradation of WDR5 suppresses oncogenic activities of SS18::SSX and provides a therapeutic of synovial sarcoma

Cancer-causing aberrations recurrently target the chromatic-regulatory factors, leading to epigenetic dysregulation. Almost all patients with synovial sarcoma (SS) carry a characteristic gene fusion, SS18::SSX, which produces a disease-specific oncoprotein that is incorporated into the switch/sucrose non-fermentable (SWI/SNF) chromatin-remodeling complexes and profoundly alters their functionalities. Targeting epigenetic dependency in cancers holds promise for improving current treatment. Leveraging on cancer cell dependency dataset, pharmacological tools, and genomic profiling, we find WDR5, a factor critical for depositing histone H3 lysine 4 (H3K4) methylation, to be an unexplored vulnerability in SS. Mechanistically, WDR5 and SS18::SSX interact and colocalize at oncogenes where WDR5 promotes H3K4 methylation and the chromatin association of SS18::SSX-containing chromatin-remodeling complexes. WDR5 degradation by proteolysis-targeting chimera (PROTAC) not only suppresses the SS18::SSX-related oncogenic programs but additionally causes the ribosomal protein deregulations leading to p53 activation. WDR5-targeted PROTAC suppresses SS growth in vitro and in vivo, providing a promising strategy for the SS treatment.

A facultative plasminogen-independent thrombolytic enzyme from Sipunculus nudus

Current thrombolytic therapies primarily function by converting plasminogen into plasmin, a process dependent on the fibrin-activator complex. This dependence, coupled with the substantial molecular size of plasmin, constrains its effectiveness in degrading D-dimer and restricts its diffusion within thrombi. Here, we introduce a small facultative plasminogen-independent thrombolytic enzyme, snFPITE, isolated from Sipunculus nudus. Compared to traditional thrombolytic agents, snFPITE does not require plasminogen for thrombolysis, although its presence enhances lytic activity. This enzyme fully degrades cross-linked fibrin without leaving residual nondegradable D-dimer and generates a smaller fibrinolytic-active agent from plasminogen. A series of male rats and mice models further confirm that snFPITE is a safety injectable thrombolytic agent. Mechanistically, snFPITE activates plasminogen and degrades fibrin(ogen) in a multisite cleavage manner. snFPITE is inhibited by plasminogen activator inhibitor 1 and α2-antiplasmin via a competitive inhibition. We further identify 28 snFPITE candidate sequences, of which 10 are confirmed as functional genes.

HIF regulates multiple translated endogenous retroviruses: Implications for cancer immunotherapy

Clear cell renal cell carcinoma (ccRCC), despite having a low mutational burden, is considered immunogenic because it occasionally undergoes spontaneous regressions and often responds to immunotherapies. The signature lesion in ccRCC is inactivation of the VHL tumor suppressor gene and consequent upregulation of the HIF transcription factor. An earlier case report described a ccRCC patient who was cured by an allogeneic stem cell transplant and later found to have donor-derived T cells that recognized a ccRCC-specific peptide encoded by a HIF-responsive endogenous retrovirus (ERV), ERVE-4. We report that ERVE-4 is one of many ERVs that are induced by HIF, translated into HLA-bound peptides in ccRCCs, and capable of generating antigen-specific T cell responses. Moreover, ERV expression can be induced in non-ccRCC tumors with clinical-grade HIF stabilizers. These findings have implications for leveraging ERVs for cancer immunotherapy.

ERVcancer: a web resource designed for querying activation of human endogenous retroviruses across major cancer types

Human endogenous retroviruses (HERVs) comprise approximately 8% of the human genome, integrated into the dynamic regulatory network of cellular potency during early embryonic development. In recent studies, resurgent the transcriptional activity of HERVs has been frequently observed in many types of human cancers, suggesting their potential functions in the occurrence and progression of malignancy. However, a dedicated web resource for querying the relationship between the activation of HERVs and cancer development is lacking. Here, we construct a database to explore the sequence information, expression profiles, survival prognosis, and genetic interactions of HERVs in diverse cancer types. Our database currently contains RNA sequencing data of 580 HERVs across 16,246 samples, including that of 6478 tumoral and 634 normal tissues, 932 cancer cell lines, as well as 151 early embryonic and 8051 human adult tissues. The primary goal is to provide an easily accessible and user-friendly database for professionals in the fields of bioinformatics, pathology, pharmacology, and related areas, enabling them to efficiently screen the activity of HERVs of interest in normal and cancerous tissues and evaluate the clinical relevance. The ERVcancer database is available at http://kyuanlab.com/ervcancer/.

The sotos syndrome gene Nsd1 safeguards developmental gene enhancers poised for transcription by maintaining the precise deposition of histone methylation

Germline haploinsufficiency of NSD1 is implicated as the etiology of Sotos syndrome; however, the underlying mechanism remains far from being clear. Here, we use mouse embryonic stem cell (mESC) differentiation as a model system to address this question. We found Nsd1 to be indispensable for the faithful differentiation of mESCs into three primary germ layers, particularly, meso-endodermal cell lineages related to the development of the heart and the skeletal system. Time-course transcriptomic profiling following the mESC differentiation revealed that Nsd1 not only facilitates the basal expression but also permits the differentiation-accompanied rapid induction of a suite of meso-endoderm lineage-specifying transcription factor genes such as T and Gata4. Mechanistically, Nsd1 directly occupies putative distal enhancers of the lineage transcription factor genes under the pluripotent cell state, where it deposits H3K36me2 to antagonize the excessive H3K27me3 and maintains the basal H3K27ac level, thereby safeguarding these gene enhancers at a primed state that responds readily to differentiation cues. In agreement, gene rescue assays using the Nsd1 KO mESCs showed that the H3K36me2 catalysis by Nsd1 requires several functional modules within Nsd1 (namely, PHD1-4, PWWP2, and SET) to a similar degree. Disruption of either one of these Nsd1 modules severely abrogated H3K36me2 in mESCs and significantly impaired appropriate induction of developmental genes upon mESC differentiation. Altogether, our study provides novel molecular insight into how the NSD1 perturbation derails normal development and causes the disease.

Viral influencers: deciphering the role of endogenous retroviral LTR12 repeats in cellular gene expression

The human genome is like a museum of ancient retroviral infections. It contains a large number of endogenous retroviruses (ERVs) that bear witness to past integration events. About 5,000 of them are so-called long terminal repeat 12 (LTR12) elements. Compared with 20,000 human genes, this is a remarkable number. Although LTR12 elements can act as promoters or enhancers of cellular genes, the function of most of these retroviral elements has remained unclear. In our mini-review, we show that different LTR12 elements share many similarities, including common transcription factor binding sites. Furthermore, we summarize novel insights into the epigenetic mechanisms governing their silencing and activation. Specific examples of genes and pathways that are regulated by LTR12 loci are used to illustrate the regulatory network built by these repetitive elements. A particular focus is on their role in the regulation of antiviral immune responses, tumor cell proliferation, and senescence. Finally, we describe how a targeted activation of this fascinating ERV family could be used for diagnostic or therapeutic purposes.

Genome-wide association study of anterior uveitis

BACKGROUND/AIMS

The purpose of this study is to define genetic factors associated with anterior uveitis through genome-wide association study (GWAS).

METHODS

In this GWAS meta-analysis, we combined data from the FinnGen, Estonian Biobank and UK Biobank with a total of 12 205 anterior uveitis cases and 917 145 controls. We performed a phenome-wide association study (PheWAS) to investigate associations across phenotypes and traits. We also evaluated genetic correlations of anterior uveitis.

RESULTS

We identified six anterior uveitis-associated loci. Genome-wide significant (p<5 × 10-8) associations were identified for the first time at three loci (innate immunity activator (INAVA), nucleotide-binding domain, leucine-rich repeat family, pyrin domain containing 3 and nitric oxide synthase 2). We detected associations at three loci previously reported to be associated with uveitis (endoplasmic reticulum aminopeptidase 1 (ERAP1), the trinucleotide repeat containing 18 (TNRC18) and the HLA region) and also replicated associations at two loci previously associated with acute anterior uveitis (IL23R and HDAC2-AS2). In PheWAS, we further detected that lead single nucleotide polymorphisms (SNPs) at three of the anterior uveitis-associated loci (ERAP1, INAVA and TNRC18) are associated with other immunity-related phenotypes, including ankylosing spondylitis and inflammatory bowel disease. Additionally, we detected a moderate genetic correlation between anterior uveitis and inflammatory bowel disease (rg =0.39, p=8 × 10-5).

CONCLUSION

We identified six anterior uveitis-associated loci, including three novel loci with genome-wide significance. Our findings deepen our understanding of the genetic basis of anterior uveitis and the genetic connections between anterior uveitis and immune-related disorders, providing a foundation for further research and potential therapeutic interventions.

Stem cell activity-coupled suppression of endogenous retrovirus governs adult tissue regeneration

Mammalian retrotransposons constitute 40% of the genome. During tissue regeneration, adult stem cells coordinately repress retrotransposons and activate lineage genes, but how this coordination is controlled is poorly understood. Here, we observed that dynamic expression of histone methyltransferase SETDB1 (a retrotransposon repressor) closely mirrors stem cell activities in murine skin. SETDB1 ablation leads to the reactivation of endogenous retroviruses (ERVs, a type of retrotransposon) and the assembly of viral-like particles, resulting in hair loss and stem cell exhaustion that is reversible by antiviral drugs. Mechanistically, at least two molecularly and spatially distinct pathways are responsible: antiviral defense mediated by hair follicle stem cells and progenitors and antiviral-independent response due to replication stress in transient amplifying cells. ERV reactivation is promoted by DNA demethylase ten-eleven translocation (TET)-mediated hydroxymethylation and recapitulated by ablating cell fate transcription factors. Together, we demonstrated ERV silencing is coupled with stem cell activity and essential for adult hair regeneration.

A constitutive heterochromatic region shapes genome organization and impacts gene expression in Neurospora crassa

BACKGROUND

Organization of the eukaryotic genome is essential for proper function, including gene expression. In metazoans, chromatin loops and Topologically Associated Domains (TADs) organize genes into transcription factories, while chromosomes occupy nuclear territories in which silent heterochromatin is compartmentalized at the nuclear periphery and active euchromatin localizes to the nucleus center. A similar hierarchical organization occurs in the fungus Neurospora crassa where its seven chromosomes form a Rabl conformation typified by heterochromatic centromeres and telomeres independently clustering at the nuclear membrane, while interspersed heterochromatic loci aggregate across Megabases of linear genomic distance to loop chromatin in TAD-like structures. However, the role of individual heterochromatic loci in normal genome organization and function is unknown.

RESULTS

We examined the genome organization of a Neurospora strain harboring a ~ 47.4 kilobase deletion within a temporarily silent, facultative heterochromatic region, as well as the genome organization of a strain deleted of a 110.6 kilobase permanently silent constitutive heterochromatic region. While the facultative heterochromatin deletion minimally effects local chromatin structure or telomere clustering, the constitutive heterochromatin deletion alters local chromatin structure, the predicted three-dimensional chromosome conformation, and the expression of some genes, which are qualitatively repositioned into the nucleus center, while increasing Hi-C variability.

CONCLUSIONS

Our work elucidates how an individual constitutive heterochromatic region impacts genome organization and function. Specifically, one silent region indirectly assists in the hierarchical folding of the entire Neurospora genome by aggregating into the "typical" heterochromatin bundle normally observed in wild type nuclei, which may promote normal gene expression by positioning euchromatin in the nucleus center.

Distinct H3K9me3 heterochromatin maintenance dynamics govern different gene programmes and repeats in pluripotent cells

H3K9me3 heterochromatin, established by lysine methyltransferases (KMTs) and compacted by heterochromatin protein 1 (HP1) isoforms, represses alternative lineage genes and DNA repeats. Our understanding of H3K9me3 heterochromatin stability is presently limited to individual domains and DNA repeats. Here we engineered Suv39h2-knockout mouse embryonic stem cells to degrade remaining two H3K9me3 KMTs within 1 hour and found that both passive dilution and active removal contribute to H3K9me3 decay within 12-24 hours. We discovered four different H3K9me3 decay rates across the genome and chromatin features and transcription factor binding patterns that predict the stability classes. A 'binary switch' governs heterochromatin compaction, with HP1 rapidly dissociating from heterochromatin upon KMT depletion and a particular threshold level of HP1 limiting pioneer factor binding, chromatin opening and exit from pluripotency within 12 h. Unexpectedly, receding H3K9me3 domains unearth residual HP1β peaks enriched with heterochromatin-inducing proteins. Our findings reveal distinct H3K9me3 heterochromatin maintenance dynamics governing gene networks and repeats that together safeguard pluripotency.

Identification of methylation-sensitive human transcription factors using meSMiLE-seq

Transcription factors (TFs) are key players in eukaryotic gene regulation, but the DNA binding specificity of many TFs remains unknown. Here, we assayed 284 mostly poorly characterized, putative human TFs using selective microfluidics-based ligand enrichment followed by sequencing (SMiLE-seq), revealing 72 new DNA binding motifs. To investigate whether some of the 158 TFs for which we did not find motifs preferably bind epigenetically modified DNA (i.e. methylated CG dinucleotides), we developed methylation-sensitive SMiLE-seq (meSMiLE-seq). This microfluidic assay simultaneously probes the affinity of a protein to methylated and unmethylated DNA, augmenting the capabilities of the original method to infer methylation-aware binding sites. We assayed 114 TFs with meSMiLE-seq and identified DNA-binding models for 48 proteins, including the known methylation-sensitive binding modes for POU5F1 and RFX5. For 11 TFs, binding to methylated DNA was preferred or resulted in the discovery of alternative, methylation-dependent motifs (e.g. PRDM13), while aversion towards methylated sequences was found for 13 TFs (e.g. USF3). Finally, we uncovered a potential role for ZHX2 as a putative binder of Z-DNA, a left-handed helical DNA structure which is adopted more frequently upon CpG methylation. Altogether, our study significantly expands the human TF codebook by identifying DNA binding motifs for 98 TFs, while providing a versatile platform to quantitatively assay the impact of DNA modifications on TF binding.

Dual roles of human endogenous retroviruses in cancer progression and antitumor immune response

Human endogenous retroviruses (HERVs) are a class of transposable elements formed by the integration of ancient retroviruses into the germline genome. They are inherited in a Mendelian manner and approximately constitute 8 % of the human genome. HERVs were considered as "junk DNA" for decades, but increasing evidence suggests that they play significant roles in pathological inflammation, neural differentiation, and oncogenesis. Specifically, HERVs expression has been implicated in several oncogenic processes and the formation of the tumor microenvironment. Indeed, the dual roles of HERVs in cancer, serving as both promoters of oncogenesis and forerunners of the innate antitumor immune response, remain a subject of debate. In this review, we will discuss how HERVs participate in cancer progression and how they are regulated. Our aim is to provide a comprehensive understanding of the fundamental properties and potential function of HERVs in propagating oncogenesis and activating the antitumor immune response. We hope that updated knowledge will reshape our understanding of the critical roles played by HERVs in human evolution and cancer progression.

A Constitutive Heterochromatic Region Shapes Genome Organization and Impacts Gene Expression in Neurospora crassa

Background

Organization of the eukaryotic genome is essential for proper function, including gene expression. In metazoans, chromatin loops and Topologically Associated Domains (TADs) organize genes into transcription factories, while chromosomes occupy nuclear territories in which silent heterochromatin is compartmentalized at the nuclear periphery and active euchromatin localizes to the nucleus center. A similar hierarchical organization occurs in the fungus Neurospora crassa where its seven chromosomes form a Rabl conformation typified by heterochromatic centromeres and telomeres independently clustering at the nuclear membrane, while interspersed heterochromatic loci aggregate across Megabases of linear genomic distance to loop chromatin in TAD-like structures. However, the role of individual heterochromatic loci in normal genome organization and function is unknown.

Results

We examined the genome organization of a Neurospora strain harboring a ~47.4 kilobase deletion within a temporarily silent, facultative heterochromatic region, as well as the genome organization of a strain deleted of a 110.6 kilobase permanently silent constitutive heterochromatic region. While the facultative heterochromatin deletion minimally effects local chromatin structure or telomere clustering, the constitutive heterochromatin deletion alters local chromatin structure, the predicted three-dimensional chromosome conformation, and the expression of some genes, which are qualitatively repositioned into the nucleus center, while increasing Hi-C variability.

Conclusions

Our work elucidates how an individual constitutive heterochromatic region impacts genome organization and function. Specifically, one silent region indirectly assists in the hierarchical folding of the entire Neurospora genome by aggregating into the "typical" heterochromatin bundle normally observed in wild type nuclei, which may promote normal gene expression by positioning euchromatin in the nucleus center.

Heterochromatin formation and remodeling by IRTKS condensates counteract cellular senescence

Heterochromatin, a key component of the eukaryotic nucleus, is fundamental to the regulation of genome stability, gene expression and cellular functions. However, the factors and mechanisms involved in heterochromatin formation and maintenance still remain largely unknown. Here, we show that insulin receptor tyrosine kinase substrate (IRTKS), an I-BAR domain protein, is indispensable for constitutive heterochromatin formation via liquid‒liquid phase separation (LLPS). In particular, IRTKS droplets can infiltrate heterochromatin condensates composed of HP1α and diverse DNA-bound nucleosomes. IRTKS can stabilize HP1α by recruiting the E2 ligase Ubc9 to SUMOylate HP1α, which enables it to form larger phase-separated droplets than unmodified HP1α. Furthermore, IRTKS deficiency leads to loss of heterochromatin, resulting in genome-wide changes in chromatin accessibility and aberrant transcription of repetitive DNA elements. This leads to activation of cGAS-STING pathway and type-I interferon (IFN-I) signaling, as well as to the induction of cellular senescence and senescence-associated secretory phenotype (SASP) responses. Collectively, our findings establish a mechanism by which IRTKS condensates consolidate constitutive heterochromatin, revealing an unexpected role of IRTKS as an epigenetic mediator of cellular senescence.

Distinct H3K9me3 heterochromatin maintenance dynamics govern different gene programs and repeats in pluripotent cells

H3K9me3-heterochromatin, established by lysine methyltransferases (KMTs) and compacted by HP1 isoforms, represses alternative lineage genes and DNA repeats. Our understanding of H3K9me3-heterochromatin stability is presently limited to individual domains and DNA repeats. We engineered Suv39h2 KO mouse embryonic stem cells to degrade remaining two H3K9me3-KMTs within one hour and found that both passive dilution and active removal contribute to H3K9me3 decay within 12-24 hours. We discovered four different H3K9me3 decay rates across the genome and chromatin features and transcription factor binding patterns that predict the stability classes. A "binary switch" governs heterochromatin compaction, with HP1 rapidly dissociating from heterochromatin upon KMTs' depletion and a particular threshold level of HP1 limiting pioneer factor binding, chromatin opening, and exit from pluripotency within 12 hr. Unexpectedly, receding H3K9me3 domains unearth residual HP1β peaks enriched with heterochromatin-inducing proteins. Our findings reveal distinct H3K9me3-heterochromatin maintenance dynamics governing gene networks and repeats that together safeguard pluripotency.

EZH2 PROTACs target EZH2- and FOXM1-associated oncogenic nodes, suppressing breast cancer cell growth

Breast cancer (BC) remains the second leading cause of cancer-related mortalities in women. Resistance to hormone therapies such as tamoxifen, an estrogen receptor (ER) inhibitor, is a major hurdle in the treatment of BC. Enhancer of zeste homolog 2 (EZH2), the methyltransferase component of the Polycomb repressive complex 2 (PRC2), has been implicated in tamoxifen resistance. Evidence suggests that EZH2 often functions noncanonically, in a methyltransferase-independent manner, as a transcription coactivator through interacting with oncogenic transcription factors. Unlike methyltransferase inhibitors, proteolysis targeting chimeras (PROTAC) can suppress both activating and repressive functions of EZH2. Here, we find that EZH2 PROTACs, MS177 and MS8815, effectively inhibited the growth of BC cells, including those with acquired tamoxifen resistance, to a much greater degree when compared to methyltransferase inhibitors. Mechanistically, EZH2 associates with forkhead box M1 (FOXM1) and binds to the promoters of FOXM1 target genes. EZH2 PROTACs induce degradation of both EZH2 and FOXM1, leading to reduced expression of target genes involved in cell cycle progression and tamoxifen resistance. Together, this study supports that EZH2-targeted PROTACs represent a promising avenue of research for the future treatment of BC, including in the setting of tamoxifen resistance.

Unzippable Siamese Nanoparticles for Programmed Two-Stage Cancer Immunotherapy

Epigenetic drugs (epi-drugs) can destruct cancer cells and initiate both innate and adaptive immunity, yet they have achieved very limited success in solid tumors so far, partly attributing to their concurrent induction of the myeloid-derived suppressor cell (MDSC) population. Here, dissociable Siamese nanoparticles (SIANPs) are developed for tumor cell-targeted delivery of epi-drug CM-272 and MDSC-targeted delivery of small molecule inhibitor Ibrutinib. The SIANPs are assembled via interparticle DNA annealing and detached via tumor microenvironment-triggered strand separation. Such binary regulation induces endogenous retrovirus expression and immunogenic cell death in tumor cells while restraining the immunosuppressive effects of MDSCs, and synergistically promotes dendritic cell maturation and CD8+ T cell activation for tumor inhibition. Significantly, immune microenvironment remodeling via SIANPs further overcomes tumor resistance to immune checkpoint blockade therapy. This study represents a two-pronged approach for orchestrating immune responses, and paves a new way for employing epi-drugs in cancer immunotherapy.

ChAHP2 and ChAHP control diverse retrotransposons by complementary activities

Retrotransposon control in mammals is an intricate process that is effectuated by a broad network of chromatin regulatory pathways. We previously discovered ChAHP, a protein complex with repressive activity against short interspersed element (SINE) retrotransposons that is composed of the transcription factor ADNP, chromatin remodeler CHD4, and HP1 proteins. Here we identify ChAHP2, a protein complex homologous to ChAHP, in which ADNP is replaced by ADNP2. ChAHP2 is predominantly targeted to endogenous retroviruses (ERVs) and long interspersed elements (LINEs) via HP1β-mediated binding of H3K9 trimethylated histones. We further demonstrate that ChAHP also binds these elements in a manner mechanistically equivalent to that of ChAHP2 and distinct from DNA sequence-specific recruitment at SINEs. Genetic ablation of ADNP2 alleviates ERV and LINE1 repression, which is synthetically exacerbated by additional depletion of ADNP. Together, our results reveal that the ChAHP and ChAHP2 complexes function to control both nonautonomous and autonomous retrotransposons by complementary activities, further adding to the complexity of mammalian transposon control.

Technology to the rescue: how to uncover the role of transposable elements in preimplantation development

Transposable elements (TEs) are highly expressed in preimplantation development. Preimplantation development is the phase when the cells of the early embryo undergo the first cell fate choice and change from being totipotent to pluripotent. A range of studies have advanced our understanding of TEs in preimplantation, as well as their epigenetic regulation and functional roles. However, many questions remain about the implications of TE expression during early development. Challenges originate first due to the abundance of TEs in the genome, and second because of the limited cell numbers in preimplantation. Here we review the most recent technological advancements promising to shed light onto the role of TEs in preimplantation development. We explore novel avenues to identify genomic TE insertions and improve our understanding of the regulatory mechanisms and roles of TEs and their RNA and protein products during early development.

Causality between Ankylosing Spondylitis and osteoarthritis in European ancestry: a bidirectional Mendelian randomization study

Objective

To explore the bidirectional causal relationship between Ankylosing Spondylitis (AS) and Osteoarthritis (OA) at the genetic level within the European ancestry.

Methods

We implemented a series of quality control steps to select instrumental variables (IVs) related to the exposure. We conducted two-sample Mendelian randomization (MR) using the inverse-variance weighted method as the primary approach. We adjusted significance levels using Bonferroni correction, assessed heterogeneity using Cochrane's Q test. Sensitivity analysis was conducted through leave-one-out method. Additionally, external datasets and relaxed IV selection criteria were employed, and multivariate MR analyses were performed for validation purposes. Finally, Bayesian colocalization (COLOC) analysis identified common genes, validating the MR results.

Results

The investigation focused on the correlation between OA and AS in knee, hip, and hand joints. MR results revealed that individuals with AS exhibit a decreased risk of knee OA (OR = 0.9882, 95% CI: 0.9804-0.9962) but no significant increase in the risk of hip OA (OR = 0.9901, 95% CI: 0.9786-1.0018). Conversely, AS emerged as a risk factor for hand OA (OR = 1.0026, 95% CI: 1.0015-1.0036). In reverse-direction MR analysis, OA did not significantly influence the occurrence of AS. Importantly, minimal heterogeneity was observed in our MR analysis results (p > 0.05), and the robustness of these findings was confirmed through sensitivity analysis and multivariate MR analysis. COLOC analysis identified four colocalized variants for AS and hand OA (rs74707996, rs75240935, rs181468789, and rs748670681).

Conclusion

In European population, individuals with AS have a relatively lower risk of knee OA, whereas AS serves as a risk factor for hand OA. However, no significant causal relationship was found between AS and hip OA. Additionally, it offers novel insights into genetic research on AS and OA.