COL10A1 expression distinguishes a subset of cancer-associated fibroblasts present in the stroma of high-risk basal cell carcinoma.

BACKGROUND: Basal cell carcinoma (BCC) is the most frequently diagnosed skin cancer and the most common malignancy in humans. Different morphological subtypes of BCC are associated with low- or high-risk of recurrence and aggressiveness, but the underlying biology of how the individual subtypes arise remains largely unknown. Because the majority of BCCs appear to arise from mutations in the same pathway, we hypothesized that BCC development, growth and invasive potential is also influenced by the tumor microenvironment and in particular by cancer-associated fibroblasts (CAFs) and their secreted factors. OBJECTIVE: We aimed to characterize the stroma of the different BCC subtypes with a focus on CAF populations. METHODS: To investigate the stromal features of the different BCC subtypes, we applied laser-capture microdissection (LCM) followed by RNA sequencing. A cohort of 15 BCC samples from 5 different "pure" subtypes (superficial, nodular, micronodular, sclerosing and basosquamous; n=3 each) were selected and included in the analysis. Healthy skin was used as a control (n=6). We confirmed the results by immunohistochemistry. We validated our findings in two independent, public single-cell RNA sequencing (scRNAseq) datasets and by RNAscope. RESULTS: The stroma of the different BCC subtypes have distinct gene expression signatures. Nodular and micronodular seem to have the most similar signatures, while superficial and sclerosing the most different. By comparing low- and high-risk BCC subtypes, we observed that Collagen 10A1 (COL10A1) is overexpressed in the stroma of sclerosing/infiltrative and basosquamous but not micronodular high-risk subtypes. Those findings were confirmed by immunohistochemistry in a cohort of 89 different BCC and 13 healthy skin samples. Moreover, scRNAseq analysis of BCCs of two independent datasets showed that the COL10A1-expressing population of cells is associated with the stroma adjacent to invasive BCC and shows extracellular matrix remodeling features. CONCLUSION: We identified COL10A1 as a marker of high-risk BCC, in particular of the sclerosing/infiltrative and basosquamous subtypes. We demonstrated at the single cell level that COL10A1 is expressed by a specific CAF population associated with the stroma of invasive BCC. This opens up new tailored treatment options as well as a new prognostic biomarker for BCC progression.

Central macular thickness change after uneventful small-incision cataract surgery - An observational study.

Purpose: The purpose of this study was to diagnose CME with the help of optical coherence tomography (OCT) after uneventful cataract surgery to prevent visual deterioration. Methods: This study was conducted on 120 patients, who underwent manual small-incision cataract surgery with posterior chamber intra-ocular lens implantation. Follow-up was performed after the first week, sixth week, and 12th week post-operatively. Detailed examination was performed at each visit along with measurements of central macular thickness using OCT. Statistical analysis was performed using SPSS 22.0. Result: The mean age of the patients was 61.85 ± 11.41 years having female preponderance. The pre-operative mean best corrected visual acuity (BCVA) was found to be 0.05 ± 0.04, whereas the mean post-operative BCVA was found to be 0.65 ± 0.17 at the first week, 0.66 ± 0.17 at the sixth week, and 0.67 ± 0.17 at the 12th week follow-up. The post-operative mean macular thicknesses at the first week, sixth week, and 12th week post-operatively were documented to be 221.66 ± 8.49 µm, 224.60 ± 8.75 µm, and 219.17 ± 8.22 µm, respectively. Conclusion: A sub-clinical increase in macular thickness occurs even after uncomplicated cataract surgery. The maximum increase was observed after 6 weeks of surgery, which returns to near normal values within 3 months. Comparison of central macular thicknesses pre-operatively and post-operatively at the first week, sixth week, and 12th week suggests a significant correlation.

Monoallelic IRF5 deficiency in B cells prevents murine lupus.

Gain-of-function polymorphisms in the transcription factor IFN regulatory factor 5 (IRF5) are associated with an increased risk of developing systemic lupus erythematosus. However, the IRF5-expressing cell type(s) responsible for lupus pathogenesis in vivo is not known. We now show that monoallelic IRF5 deficiency in B cells markedly reduced disease in a murine lupus model. In contrast, similar reduction of IRF5 expression in macrophages, monocytes, and neutrophils did not reduce disease severity. B cell receptor and TLR7 signaling synergized to promote IRF5 phosphorylation and increase IRF5 protein expression, with these processes being independently regulated. This synergy increased B cell-intrinsic IL-6 and TNF-α production, both key requirements for germinal center (GC) responses, with IL-6 and TNF-α production in vitro and in vivo being substantially lower with loss of 1 allele of IRF5. Mechanistically, TLR7-dependent IRF5 nuclear translocation was reduced in B cells from IRF5-heterozygous mice. In addition, we show in multiple lupus models that IRF5 expression was dynamically regulated in vivo with increased expression in GC B cells compared with non-GC B cells and with further sequential increases during progression to plasmablasts and long-lived plasma cells. Overall, a critical threshold level of IRF5 in B cells was required to promote disease in murine lupus.