Fibrotic skin disease represents a major global healthcare burden, characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix. Fibroblasts are found to be heterogeneous in multiple fibrotic diseases, but fibroblast heterogeneity in fibrotic skin diseases is not well characterized. In this study, we explore fibroblast heterogeneity in keloid, a paradigm of fibrotic skin diseases, by using single-cell RNA-seq. Our results indicate that keloid fibroblasts can be divided into 4 subpopulations: secretory-papillary, secretory-reticular, mesenchymal and pro-inflammatory. Interestingly, the percentage of mesenchymal fibroblast subpopulation is significantly increased in keloid compared to normal scar. Functional studies indicate that mesenchymal fibroblasts are crucial for collagen overexpression in keloid. Increased mesenchymal fibroblast subpopulation is also found in another fibrotic skin disease, scleroderma, suggesting this is a broad mechanism for skin fibrosis. These findings will help us better understand skin fibrotic pathogenesis, and provide potential targets for fibrotic disease therapies.

Polygenic risk scores (PRS) have the potential to identify individuals at risk of diseases, optimizing treatment, and predicting survival outcomes. Here, we construct and validate a genome-wide association study (GWAS) derived PRS for nasopharyngeal carcinoma (NPC), using a multi-center study of six populations (6 059 NPC cases and 7 582 controls), and evaluate its utility in a nested case-control study. We show that the PRS enables effective identification of NPC high-risk individuals (AUC = 0.65) and improves the risk prediction with the PRS incremental deciles in each population (Ptrend ranging from 2.79 × 10−7 to 4.79 × 10−44). By incorporating the PRS into EBV-serology-based NPC screening, the test’s positive predictive value (PPV) is increased from an average of 4.84% to 8.38% and 11.91% in the top 10% and 5% PRS, respectively. In summary, the GWAS-derived PRS, together with the EBV test, significantly improves NPC risk stratification and informs personalized screening.

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Keloids represent one extreme of aberrant dermal wound healing. One of the important characteristics of keloids is uncontrolled fibroblasts proliferation. However, the mechanism of excessive proliferation of fibroblasts in keloids remains elusive. In this study, we demonstrated that TRAF4 was highly expressed in keloid fibroblasts and promoted fibroproliferation. We investigated the underlying molecular mechanism and found that TRAF4 suppressed the p53 pathway independent of its E3 ubiquitin ligase activity. Specifically, TRAF4 interacted with the deubiquitinase USP10 and blocked the access of p53 to USP10, resulting in p53 destabilization. Knockdown of p53 rescued cell proliferation in TRAF4-knockdown keloid fibroblasts, suggesting that the regulation of proliferation by TRAF4 in keloids relied on p53. Furthermore, in keloid patient samples, TRAF4 expression was inversely correlated with p53ep21 signaling activity. These findings help to elucidate the mechanisms underlying keloid development and indicate that blocking TRAF4 could represent a potential strategy for keloid therapy in the future.

Genetic susceptibility underlies the pathogenesis of cancer. We and others have previously identified a novel susceptibility gene , which encodes an orphan member of the TNF receptor superfamily known to be associated with nasopharyngeal carcinoma (NPC) and lung cancer risk. Here, we show that TNFRSF19 is highly expressed in NPC and is required for cell proliferation and NPC development. However, unlike most of the TNF receptors, TNFRSF19 was not involved in NFκB activation or associated with TRAF proteins. We identified TGFβ receptor type I (TβRI) as a specific binding partner for TNFRSF19. TNFRSF19 bound the kinase domain of TβRI in the cytoplasm, thereby blocking Smad2/3 association with TβRI and subsequent signal transduction. Ectopic expression of TNFRSF19 in normal epithelial cells conferred resistance to the cell-cycle block induced by TGFβ, whereas knockout of TNFRSF19 in NPC cells unleashed a potent TGFβ response characterized by upregulation of Smad2/3 phosphorylation and TGFβ target gene transcription. Furthermore, elevated TNFRSF19 expression correlated with reduced TGFβ activity and poor prognosis in patients with NPC. Our data reveal that gain of function of TNFRSF19 in NPC represents a mechanism by which tumor cells evade the growth-inhibitory action of TGFβ., a susceptibility gene for nasopharyngeal carcinoma and other cancers, functions as a potent inhibitor of the TGFβ signaling pathway. http://cancerres.aacrjournals.org/content/canres/78/13/3469/F1.large.jpg .