Integrative Single-Cell RNA-Seq and ATAC-Seq Analysis of Mouse Corneal Epithelial Cells.

Purpose: Corneal epithelial homeostasis is maintained by coordinated gene expression across distinct cell populations, but the gene regulatory programs underlying this cellular diversity remain to be characterized. Here we applied single-cell multi-omics analysis to delineate the gene regulatory profile of mouse corneal epithelial cells under normal homeostasis. Methods: Single cells isolated from the cornea epithelium (with marginal conjunctiva) of adult mice were subjected to scRNA-seq and scATAC-seq using the 10×Genomics platform. Cell types were clustered by the graph-based visualization method uniform manifold approximation and projection and unbiased computational informatics analysis. The scRNA-seq and scATAC-seq datasets were integrated following the integration pipeline described in ArchR and Seurat. Results: We characterized diverse corneal epithelial cell types based on gene expression signatures and chromatin accessibility. We found that cell type-specific accessibility regions were mainly located at distal regions, suggesting essential roles of distal regulatory elements in determining corneal epithelial cell diversity. Trajectory analyses revealed a continuum of cell state transition and higher coordination between transcription factor (TF) motif accessibility and gene expression during corneal epithelial cell differentiation. By integrating transcriptomic and chromatin accessibility analysis, we identified cell type-specific and shared gene regulation programs. We also uncovered critical TFs driving corneal epithelial cell differentiation, such as nuclear factor I (NFI) family members, Rarg, Elf3. We found that nuclear factor-κB (NF-κB) family members were positive TFs in limbal cells and some superficial cells, but they were involved in regulating distinct biological processes. Conclusions: Our study presents a comprehensive gene regulatory landscape of mouse cornea epithelial cells, and provides valuable foundations for future investigation of corneal epithelial homeostasis in the context of cornea pathologies and regenerative medicine.

Acquired coagulation dysfunction resulting from vitamin K-dependent coagulation factor deficiency associated with rheumatoid arthritis: A case report.

BACKGROUND: Rheumatoid arthritis (RA) is a common chronic inflammatory autoimmune disease with the main clinical feature of progressive joint synovial inflammation, which can lead to joint deformities as well as disability. RA often causes damage to multiple organs and systems within the body, including the blood hemostasis system. Few reports have focused on acquired coagulation dysfunction resulting from vitamin K-dependent coagulation factor deficiency associated with RA. CASE SUMMARY: A 64-year-old woman with a history of RA presented to our hospital, complaining of painless gross hematuria for 2 wk. Blood coagulation function tests showed increased prothrombin time, international normalized ratio, and activated partial thromboplastin time. Abnormal blood coagulation factor (F) activity was detected (FII, 7.0%; FV, 122.0%; and FX, 6.0%), indicating vitamin K-dependent coagulation factor deficiency. Thromboelastography and an activated partial thromboplastin time mixed correction experiment also suggested decreased coagulation factor activity. Clinically, the patient was initially diagnosed with hematuria, RA, and vitamin K-dependent coagulation factor deficiency. The patient received daily intravenous administration of vitamin K1 20 mg, etamsylate 3 g, and vitamin C 3000 mg for 10 d. Concurrently, oral leflunomide tablets and prednisone were administered for treatment of RA. After the treatment, the patient's symptoms improved markedly and she was discharged on day 12. There were no hemorrhagic events during 18 mo of follow- up. CONCLUSION: RA can result in vitamin K-dependent coagulation factor deficiency, which leads to acquired coagulation dysfunction. Vitamin K1 supplementation has an obvious effect on coagulation dysfunction under these circumstances.

LncRNA PRNCR1 rs1456315 and CCAT2 rs6983267 Polymorphisms on 8q24 Associated with Lung Cancer.

BACKGROUND: Long noncoding RNA single nucleotide polymorphisms (lncRNA-SNPs) PCAT1 rs710886, PRNCR1 rs1456315 and CCAT2 rs6983267 on 8q24 region present generalizability in the susceptibility to multiple cancers, however, the influence of rs710886, rs1456315 and rs6983267 on lung cancer has not been assessed. The aim of this study was to investigate associations between three lncRNA-SNPs and lung cancer. METHODS: A case-control study was performed on 438 patients with lung cancer and 456 healthy controls in the Han population from southern China. The collected samples were genotyped by the TaqMan genotyping, and the association with clinical characteristics, including age, gender, drinking status, smoking status, pathological types and clinical stages were analyzed. And the SNP function prediction was based on lncRNASNP2, RNAfold and GTEx. RESULTS: The rs1456315 T allele increased the risk of lung cancer [OR=1.95, 95% CI (1.58-2.43), P=0.003] compared to the rs1456315 C allele, and rs1456315 significantly increased the risk of lung cancer in the dominant model [OR=1.86, 95% CI (1.16-3.00), P=0.002]. The rs6983267 G allele, compared with the T allele, increased the risk of lung cancer [OR=1.29, 95% CI (1.07-1.57), P=0.007], and rs6983267 was identified as a risk factor for lung cancer [OR=1.28, 95% CI (1.06-1.55), P=0.003] in the additive model. Both rs1456315 and rs6983267 demonstrated significance after adjusting for the smoking status, drinking status and age. The structure prediction found rs6983267 and rs1456315 influence the secondary structure of its lncRNA. The results from lncRNASNP2 indicated that rs6983267 and rs1456315 change gain/loss target of miRNAs. CONCLUSION: PRNCR1 rs1456315 and CCAT2 rs6983267 on 8q24 region are significantly associated with lung cancer in the Han population of southern China and alter the potential biological function in bioinformatic analysis, and the results further extended generalism of the susceptibility of cancer-associated lncRNA-SNPs to lung cancer and underlying mechanism involved in lung cancer.

G206D Mutation of Presenilin-1 Reduces Pen2 Interaction, Increases Aß42/Aß40 Ratio and Elevates ER Ca(2+) Accumulation.

Early-onset familial Alzheimer's disease (AD) is most commonly associated with the mutations in presenilin-1 (PS1). PS1 is the catalytic component of the γ-secretase complex, which cleaves amyloid precursor protein to produce amyloid-ß (Aß), the major cause of AD. Presenilin enhancer 2 (Pen2) is critical for activating γ-secretase and exporting PS1 from endoplasmic reticulum (ER). Among all the familial AD-linked PS1 mutations, mutations at the G206 amino acid are the most adjacent position to the Pen2 binding site. Here, we characterized the effect of a familial AD-linked PS1 G206D mutation on the PS1-Pen2 interaction and the accompanied alteration in γ-secretase-dependent and -independent functions. We found that the G206D mutation reduced PS1-Pen2 interaction, but did not abolish γ-secretase formation and PS1 endoproteolysis. For γ-secretase-dependent function, the G206D mutation increased Aß42 production but not Notch cleavage. For γ-secretase-independent function, this mutation disrupted the ER calcium homeostasis but not lysosomal calcium homeostasis and autophagosome maturation. Impaired ER calcium homeostasis may due to the reduced mutant PS1 level in the ER. Although this mutation did not alter the cell survival under stress, both increased Aß42 ratio and disturbed ER calcium regulation could be the mechanisms underlying the pathogenesis of the familial AD-linked PS1 G206D mutation.