Faculty Bibliography

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a severe adult-onset inflammatory disease caused by somatic mutations that reduce cytoplasmic activity of UBA1, the primary initiating enzyme for ubiquitylation. How this hypomorphic state drives cell-intrinsic immune activation in mature myeloid cells is unknown. Using unbiased multi-omic, biochemical, and cell biological analyses of model systems and patient-derived cells, we show that loss of cytoplasmic UBA1 activity convergently disrupts endoplasmic reticulum-associated degradation (ERAD) and mitochondrial homeostasis. ERAD failure arises from preferential under-charging of ERAD E2 enzymes, explaining hallmark VEXAS features, including ER-derived vacuoles and unfolded protein response activation, and promotes accumulation of the ERAD substrate STING. Simultaneously, mitochondrial dysfunction drives cytosolic leakage of mitochondrial DNA, inducing cGAS-dependent STING signaling and inflammatory cytokine production. STING inhibition or reversal of mitochondrial DNA leakage resolves multi-cytokine inflammation in VEXAS models and patient myeloid cells, establishing the cGAS-STING pathway as a therapeutically actionable vulnerability.

Somatic mutations rewire the ubiquitin-proteasome system (UPS) to support tumor growth, but the proteome-wide consequences of cancer-driver alterations on UPS composition remain incompletely understood. Using harmonized proteogenomic data from up to 11 CPTAC cohorts, we performed an integrated pan-cancer analysis of UPS protein dysregulation, prognostic associations, and mutation-driven remodeling. We show that mRNA poorly predicts UPS protein abundance, that a defined set of E3 ligases is recurrently dysregulated across cancers, and that somatic mutations (most strikingly TP53 loss) produce coherent UPS protein-quantitative trait locus (pQTL) signatures. Two case studies (UBR5 and TRIM28) illustrate orthogonal modes of UPS rewiring: a mutation-driven axis in which TP53-mutant tumors elevate UBR5 to support replication stress tolerance, and a lineage-driven axis in which TRIM28 engages tissue-restricted regulatory networks with opposing prognostic effects in glioblastoma versus head and neck cancer. Each axis exposes context-specific therapeutic vulnerabilities, including sensitivity to DNA damage response inhibitors (UBR5-high) and lineage-specific drug responses (TRIM28-high). Together, these analyses define a mechanistic framework for how cancer-driver mutations reshape proteostasis through the UPS and nominate mutation- and lineage-defined dependencies for precision degrader therapy. The harmonized pan-tissue atlas and the UbiDash interactive resource that underpin parts of this analysis are reported in our companion paper [1].

Targeted protein degradation repurposes endogenous E3 ubiquitin ligases to eliminate disease-driving proteins, yet the ligase toolkit deployed clinically remains narrow and largely tissue-agnostic. To support rational expansion of this toolkit, we built a harmonized pan-tissue proteomic atlas of the ubiquitin-proteasome system (UPS) by integrating four major resources: (1) CPTAC tumor and normal-adjacent tissues, (2) PRIDE healthy tissues, (3) the Pan-Cancer Proteome Atlas (TPCPA), and (4) the Cancer Cell Line Encyclopedia (CCLE). The resulting atlas spans 20 distinct tissue contexts and quantifies 5998 proteins, including 473 UPS components and 181 E3 ligases. Cross-resource validation confirmed successful harmonization while maintaining biological signal. We then derived a sample-level relative rank score (RRS) for every quantified UPS protein and identified 139 E3 ligases (of 181 detected) as being significantly tissue- or tumor-specific, including XIAP in lung cancer, KLHL7 in female-specific malignancies, and FBXL18 in head-and-neck and brain tumors. To enable broad accessibility, we developed UbiDash ( https://ruggleslab.shinyapps.io/UbiDash/ ), an interactive R Shiny platform that supports queries of UPS expression, mutation effects, protein co-regulation, and clinical associations. Together, the atlas and UbiDash provide a tissue-aware framework for ligase prioritization and rational degrader design that complements the mechanistic mutation- and lineage-driven UPS analyses described in our companion manuscript [1].

Chronic coronary disease (CCD) remains a leading cause of morbidity and mortality worldwide. However, current clinical assessments, including tests of inducible ischemia or coronary artery disease severity poorly discriminate risk for future cardiovascular (CV) disease events among this population with established CCD. To address this gap, our study leverages high-dimensional molecular data from the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) Trials biorepository to molecularly characterize patients with CCD. By integrating transcriptomic (N = 646) and methylomic (N = 732) data with core-lab confirmed clinical phenotyping, we describe molecular signatures associated with disease severity and identify distinct whole-blood molecular subtypes of CCD. These subtypes demonstrate differential risks of CV events, independent of traditional clinical risk scores, and have distinct molecular and immune profiles. Validation of the transcriptomic and methylomic subtypes in two independent external cohorts confirms the clinical relevance and generalizability of our findings. These findings underscore the potential of blood-based multi-omic approaches to refine risk stratification, improve personalized treatment strategies and advance secondary prevention in CCD. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT01471522; https://clinicaltrials.gov/ct2/show/NCT01471522.

We present MelOD (Melanoma Omics Dashboard), a free, web-based interactive platform integrating preprocessed data from 16 melanoma studies, including eight bulk transcriptomics, six single-cell RNA-seq, and two proteomics datasets. MelOD provides user-friendly visualization and analysis tools, differential expression, dimensionality reduction, clustering, correlation, and survival analysis without requiring local computational resources. Several datasets include annotations for immunotherapy response, facilitating exploration of resistance and response signatures. Built on RShiny with optimized handling of large datasets, MelOD supports real-time hypothesis generation, cross-study validation, and community dataset contributions. Freely accessible online, MelOD lowers barriers to multi-omics research in melanoma and related fields.

BACKGROUND:Epigenetic modification of the APOL1 gene carrying risk alleles (G1 and G2) may represent a therapeutic strategy for APOL1-related kidney diseases. However, DNA methylation changes associated with APOL1 have not been thoroughly characterized. METHODS:) and with urine albumin-to-creatinine ratio (ACR). Methylation patterns were additionally assessed for differentially methylated regions and associations with kidney function. We further evaluated whether APOL1 risk-associated CpGs can modulate the relationship between APOL1 risk alleles and kidney function measures. RESULTS:and ACR. APOL1 risk-associated CpGs showed significant interactions with APOL1 risk alleles in relation to kidney function. CONCLUSION/CONCLUSIONS:APOL1 risk alleles are associated with complex DNA methylation alterations across the APOL1-APOL4-MYH9 region, potentially regulating multiple genes within this locus. APOL1 risk-associated CpGs may represent therapeutic targets for APOL1-related kidney diseases.

OBJECTIVES/OBJECTIVE:The gut microbiome plays a crucial role in regulating systemic immunity and has been implicated in several chronic inflammatory diseases. Intestinal expansions of Ruminococcus gnavus (RG), a dominant gut commensal, correlate with disease flares in lupus nephritis (LN), but the underlying mechanism remains unknown. METHODS:In a Pilot cohort of patients with biopsy-proven LN, subsetted by gut microbiota community, immune status was characterised using bulk-blood RNA sequencing libraries, serum levels of representative host proteins, and levels of immunoglobulin (Ig)G antibodies to the novel lipoglycan (LG) produced by pathogenic RG strains. A Validation LN cohort was evaluated for blood transcriptomic profiles and levels of anti-LG antibodies. In murine models, mechanistic hypotheses were tested after RG gut colonisation or after intraperitoneal injection with an LG preparation, with outcomes determined by transcriptomic analyses, platelet functional readouts, and tissue histology. RESULTS:In a Pilot cohort of patients with LN, RG gut expansions were associated with high-level platelet, neutrophil, and monocyte activation. Serum levels of platelet factor 4 and release of neutrophil extracellular traps (NETs) were significantly higher in patients with high serum IgG antibody against the novel RG-specific LG, a marker of in vivo immune exposure. An LN Validation cohort confirmed these correlates and showed that anti-LG antibodies serve as a surrogate for thromboinflammatory profile in this LN-associated endotype. In mice, gut colonisation with LG-producing RG strains or a single LG injection caused megakaryocytosis and platelet activation; RG colonisation with LG-producing strains induced tubulointerstitial injury with NETosis. In vivo responses to LG toxin were Toll-like receptor 2-dependent. CONCLUSIONS:Gut expansions of the RG pathobiont may contribute to autoimmune pathogenesis through the LG toxin and cause LN flares through thromboinflammatory mechanisms in this previously unrecognised LN endotype.

Breast cancer remains the second leading cause of cancer-related mortality among women, with triple-negative breast cancer (TNBC) exhibiting a particularly poor five-year prognosis. Here, we demonstrated that, among genetic and pharmacological perturbations targeting DNA replication, suppression of DNA polymerase epsilon (POLE) induced a potent, TNBC-specific gene expression signature enriched in inflammatory cytokines that are transcriptional targets of NF-κB. TNBC cells exhibited markedly higher levels of DNA damage and canonical NF-κB activation compared to luminal breast cancer cells. Notably, NF-κB activation in this context depended on the canonical component RELA but not the non-canonical component RELB. Mechanistically, ATM, STING, and RIG-I each contributed to NF-κB activation following POLE suppression. POLE suppression in an in vivo murine TNBC model led to cancer cell-intrinsic elimination of tumor burden and increased immune cell infiltration. Together, these findings support a model in which replication stress from POLE inhibition triggers robust NF-κB-mediated inflammation and immune microenvironment remodeling in TNBC and can independently trigger tumor eradication. These results suggest a potential therapeutic avenue for targeting POLE in TNBC.