Tumor and stroma COL8A1 secretion induces autocrine and paracrine progression signaling in pancreatic ductal adenocarcinoma.

Several collagen subtypes are involved in pancreatic ductal adenocarcinoma (PDAC) desmoplasia, which constrains therapeutic efficacy. We evaluated collagen type VIII alpha 1 chain (COL8A1), whose function in PDAC is currently unknown. We identified COL8A1 expression in 7 examined PDAC cell lines by microarray analysis, western blotting, and RT‒qPCR. Higher COL8A1 expression occurred in 2 gemcitabine-resistant PDAC cell lines; pancreas tissue (n=15) from LSL-KrasG12D/+; p48-Cre mice with advanced PDAC predisposition; and PDAC parenchyma and stroma of a patient tissue microarray (n=82). Bioinformatic analysis confirmed higher COL8A1 expression in PDAC patient tissue available from TCGA (n=183), GTEx (n=167), and GEO (n=261) databases. siRNA or lentiviral sh-mediated COL8A1 inhibition in PDAC cells reduced migration, invasion and gemcitabine resistance and resulted in lower cytidine deaminase and thymidine kinase 2 expression and was rescued by COL8A1-secreting cancer-associated fibroblasts (CAFs). The activation of COL8A1 expression involved cJun/AP-1, as demonstrated by CHIP assay and siRNA inhibition. Downstream of COL8A1, activation of ITGB1 and DDR1 receptors and PI3K/AKT and NF-κB signaling occurred, as detected by expression, adhesion and EMSA binding studies. Orthotopic transplantation of PDAC cells with downregulated COL8A1 expression resulted in reduced tumor xenograft growth and lower gemcitabine resistance but was prevented by cotransplantation of COL8A1-secreting CAFs. Most importantly, COL8A1 expression in PDAC patient tissues from our clinic (n=84) correlated with clinicopathological data, and we confirmed these findings by the use of patient data (n=177) from the TCGA database. These findings highlight COL8A1 expression in tumor and stromal cells as a new biomarker for PDAC progression.

COL8A1 facilitates the growth of triple-negative breast cancer via FAK/Src activation.

PURPOSE: Triple-negative breast cancer (TNBC) is one of the most aggressive breast cancer subtypes, and treatment options are limited because of the lack of signature molecules and heterogeneous properties of cancer. COL8A1 expression is higher in breast cancer than in normal tissues and is strongly correlated with worse overall survival in patients with breast cancer. However, the biological function of COL8A1 on cancer progression is not fully understood. In this study, we investigated the biological function of COL8A1 on TNBC progression. METHODS: COL8A1-deficient cells were generated using the CRISPR-Cas9 system. The tumor growth and metastasis of TNBC cells were evaluated using three-dimensional culture (3D) methods and xenograft mouse models. The activation of focal adhesion kinase (FAK)/Src by COL8A1 in TNBC cells was evaluated by immunoblotting. RESULTS: COL8A1 expression was primarily distributed into TNBC cell lines. Further, relapse-free survival in TNBC patients with the MSL subtype was strongly associated with the COL8A1 expression. MDA-MB-231 and Hs578T cells, classified as the MSL subtype, strongly express COL8A1, and COL8A1 protein expression was induced by hypoxia in both cell lines. Loss of COL8A1 expression inhibited spheroid /tumor growth and metastasis in vitro and in vivo. Further, exogenous COL8A1 promoted TNBC growth via the FAK/Src activation. Finally, the spheroid growth of MDA-MB-231 and Hs578T cells was inhibited by defactinib, a FAK inhibitor, without cytotoxicity. CONCLUSION: These results indicate that COL8A1-mediated FAK/Src activation produces a more aggressive phenotype in TNBC, and its target inhibition may be an efficacious treatment for TNBC.

Serum Levels of ARMS2, COL8A1, RAD51B, and VEGF and their Correlations in Age-related Macular Degeneration.

BACKGROUND: Many factors including genetic and environmental are responsible for the incidence of Age-related Macular Degeneration (AMD). However, its pathogenesis has not been clearly elucidated yet. OBJECTIVE: This study aimed to estimate the Age-Related Maculopathy Susceptibility 2 (ARMS2), Collagen type VIII Alpha 1 chain (COL8A1), Rad 51 paralog(RAD51B), and Vascular Endothelial Growth Factor (VEGF) protein levels in serum of AMD and control participants and to further investigate their correlation to understand AMD pathogenesis. METHODS: For this case-control study, 31 healthy control and 57 AMD patients were recruited from Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. A blood sample was taken and serum was isolated from it. ELISA (enzyme-linked immunosorbent assay) was used for the estimation of proteins in the serum of patients. RESULTS: ARMS2 and COL8A1 levels were significantly elevated in the AMD group than in the control group. The highest levels of ARMS2, COL8A1, and VEGF proteins were recorded for the wet AMD sub-group. The study results endorsed significant positive correlation between these following molecules; ARMS2 and COL8A1 (r = 0.933, p < 0.0001), ARMS2 and RAD51B (r = 0.704, p < 0.0001), ARMS2 and VEGF (r = 0.925, p < 0.0001), COL8A1 and RAD51B (r = 0.736, p < 0.0001), COL8A1 and VEGF (r = 0.879, p < 0.0001), and RAD51B and VEGF (r = 0.691, p < 0.0001). CONCLUSION: The ARMS2 and COL8A1 levels were significantly higher and RAD51B was significantly lower in the AMD group than controls. Also, a significant statistical correlation was detected between these molecules, indicating that their interaction may be involved in the pathogenesis of AMD.

Start codon disruption with CRISPR/Cas9 prevents murine Fuchs' endothelial corneal dystrophy.

A missense mutation of collagen type VIII alpha 2 chain (COL8A2) gene leads to early-onset Fuchs' endothelial corneal dystrophy (FECD), which progressively impairs vision through the loss of corneal endothelial cells. We demonstrate that CRISPR/Cas9-based postnatal gene editing achieves structural and functional rescue in a mouse model of FECD. A single intraocular injection of an adenovirus encoding both the Cas9 gene and guide RNA (Ad-Cas9-Col8a2gRNA) efficiently knocked down mutant COL8A2 expression in corneal endothelial cells, prevented endothelial cell loss, and rescued corneal endothelium pumping function in adult Col8a2 mutant mice. There were no adverse sequelae on histology or electroretinography. Col8a2 start codon disruption represents a non-surgical strategy to prevent vision loss in early-onset FECD. As this demonstrates the ability of Ad-Cas9-gRNA to restore the phenotype in adult post-mitotic cells, this method may be widely applicable to adult-onset diseases, even in tissues affected with disorders of non-reproducing cells.

Collagen type VIII alpha 2 chain (COL8A2), an important component of the basement membrane of the corneal endothelium, facilitates the malignant development of glioblastoma cells via inducing EMT.

Glioblastoma (GBM) is one of the most lethal tumor of all human cancers. Due to its poor response to chemotherapy and radiotherapy as well as its high rate of recurrence after treatment, the treatment is still undesired. The identification of potential related genes and bio-markers in the development of GBM could provide some new targets for the treatment of GBM. Our purpose in this study was to evaluate the mission of COL8A2 in GBM. Combined with TCGA, Oncomine databases, CGGA, GEPIA website and qRT-PCR analyses, we found that COL8A2 was up-regulated both in GBM tissues and cells compared to the controls. Moreover, the high COL8A2 expression was associated with the shorter overall survival of patients with GBM. The expression of COL8A2 was also positively correlated with metastasis-associated genes including vimentin, snail, slug, MMP2 and MMP7 according to GEPIA website. Knockdown of COL8A2 could suppress the cell proliferation, cell migration and invasion, whereas the overexpression of COL8A2 significantly expedited these processes. What's more, the outcome of western blot analysis manifested that COL8A2 could induced the expression of vimentin, snail, slug, MMP2 and MMP7. Taken together, COL8A2 activated cell proliferation, cell migration and invasion via raising the relative expression of EMT-related proteins in GBM. Therefore, our investigation suggests the oncogenic role of COL8A2 in GBM and provides a potential application of COL8A2 for GBM therapy.

Variable phenotype of Knobloch syndrome due to biallelic COL18A1 mutations in children.

PURPOSE: Knobloch syndrome is a rare, recessively inherited disorder classically characterized by high myopia, retinal detachment, and occipital encephalocele. Our aim is to report the clinical and genetic findings of four Israeli children affected by Knobloch syndrome. METHODS: Retrospective study of four patients diagnosed with Knobloch syndrome, who underwent full ophthalmic examination, electroretinography, and neuroradiologic imaging. Genetic analysis included whole exome sequencing (WES) and Sanger sequencing. RESULTS: The four patients included in this study had high myopia and nystagmus at presentation. Ocular findings included vitreous syneresis, macular atrophy, macular coloboma, and retinal detachment. One child had iris transillumination defects and an albinotic fundus, initially leading to an erroneous clinical diagnosis of albinism. Electroretinography revealed a marked cone-rod pattern of dysfunction in all four children. Brain imaging demonstrated none to severe occipital pathology. Cutaneous scalp changes were present in three patients. WES analysis, confirmed by Sanger sequencing revealed COL18A1 biallelic null mutations in all affected individuals, consistent with autosomal recessive inheritance. CONCLUSIONS: This report describes variable features in patients with Knobloch syndrome, including marked lack of eye pigment similar to albinism in one child, macular coloboma in two children as well as advanced cone-rod dysfunction in all children. One patient had normal neuroradiologic findings, emphasizing that some affected individuals have isolated ocular disease. Awareness of this syndrome, with its variable phenotype may aid early diagnosis, monitoring for potential complications, and providing appropriate genetic counseling.

COL8A2 Regulates the Fate of Corneal Endothelial Cells.

Purpose: To investigate the effect of COL8A2 repression on corneal endothelial cells (CECs) in vitro and in vivo. Methods: Cultured human CECs (hCECs) were transfected with COL8A2 siRNA (siCOL8A2), and the cell viability and proliferation rate were measured. The expression of cell proliferation-associated molecules was evaluated by Western blotting and real-time reverse transcription PCR. Cell shape, Wingless-INT (WNT) signaling, and mitochondrial oxidative stress were also measured. For in vivo experiments, siCOL8A2 was transfected into rat CECs (rCECs), and corneal opacity and corneal endothelium were evaluated. Results: After transfection with siCOL8A2, COL8A2 expression was reduced (80%). Cell viability, cell proliferation rate, cyclin D1 expression, and the number of cells in the S-phase were reduced in siCOL8A2-treated cells. The cell attained a fibroblast-like shape, and SNAI1, pSMAD2, and ß-catenin expression, along with mitochondrial mass and oxidative stress levels, were altered. Corneal opacity increased, and the CECs were changed in rats in the siCOL8A2 group. Conclusions: COL8A2 is required to maintain normal wound healing and CEC function.

Zonal regulation of collagen-type proteins and posttranslational modifications in prostatic benign and cancer tissues by imaging mass spectrometry.

BACKGROUND: The emergence of reactive stroma is a hallmark of prostate cancer (PCa) progression and a potential source for prognostic and diagnostic markers of PCa. Collagen is a main component of reactive stroma and changes systematically and quantitatively to reflect the course of PCa, yet has remained undefined due to a lack of tools that can define collagen protein structure. Here we use a novel collagen-targeting proteomics approach to investigate zonal regulation of collagen-type proteins in PCa prostatectomies. METHODS: Prostatectomies from nine patients were divided into zones containing 0%, 5%, 20%, 70% to 80% glandular tissue and 0%, 5%, 25%, 70% by mass of PCa tumor following the McNeal model. Tissue sections from zones were graded by a pathologist for Gleason score, percent tumor present, percent prostatic intraepithelial neoplasia and/or inflammation (INF). High-resolution accurate mass collagen targeting proteomics was done on a select subset of tissue sections from patient-matched tumor or nontumor zones. Imaging mass spectrometry was used to investigate collagen-type regulation corresponding to pathologist-defined regions. RESULTS: Complex collagen proteomes were detected from all zones. COL17A and COL27A increased in zones of INF compared with zones with tumor present. COL3A1, COL4A5, and COL8A2 consistently increased in zones with tumor content, independent of tumor size. Collagen hydroxylation of proline (HYP) was altered in tumor zones compared with zones with INF and no tumor. COL3A1 and COL5A1 showed significant changes in HYP peptide ratios within tumor compared with zones of INF (2.59 ± 0.29, P value: .015; 3.75 ± 0.96 P value .036, respectively). By imaging mass spectrometry COL3A1 showed defined localization and regulation to tumor pathology. COL1A1 and COL1A2 showed gradient regulation corresponding to PCa pathology across zones. Pathologist-defined tumor regions showed significant increases in COL1A1 HYP modifications compared with COL1A2 HYP modifications. Certain COL1A1 and COL1A2 peptides could discriminate between pathologist-defined tumor and inflammatory regions. CONCLUSIONS: Site-specific posttranslational regulation of collagen structure by proline hydroxylation may be involved in reactive stroma associated with PCa progression. Translational and posttranslational regulation of collagen protein structure has potential for new markers to understand PCa progression and outcomes.

Four Loci Are Associated with Cardiorespiratory Fitness and Endurance Performance in Young Chinese Females.

Cardiorespiratory fitness (CRF) and endurance performance are characterized by a complex genetic trait with high heritability. Although research has identified many physiological and environmental correlates with CRF, the genetic architecture contributing to CRF remains unclear, especially in non-athlete population. A total of 762 Chinese young female participants were recruited and an endurance run test was used to determine CRF. We used a fixed model of genome-wide association studies (GWAS) for CRF. Genotyping was performed using the Affymetrix Axiom and illumina 1 M arrays. After quality control and imputation, a linear regression-based association analysis was conducted using a total of 5,149,327 variants. Four loci associated with CRF were identified to reach genome-wide significance (P < 5.0 × 10-8), which located in 15q21.3 (rs17240160, P = 1.73 × 10-9, GCOM1), 3q25.31 (rs819865, P = 8.56 × 10-9, GMPS), 21q22.3 (rs117828698, P = 9.59 × 10-9, COL18A1), and 17q24.2 (rs79806428, P = 3.85 × 10-8, PRKCA). These loci (GCOM1, GMPS, COL18A1 and PRKCA) associated with cardiorespiratory fitness and endurance performance in Chinese non-athlete young females. Our results suggest that these gene polymorphisms provide further genetic evidence for the polygenetic nature of cardiorespiratory endurance and be used as genetic biomarkers for future research.

Identification of proliferative diabetic retinopathy-associated genes on the protein-protein interaction network by using heat diffusion algorithm.

Diabetic retinopathy is a common complication of diabetes mellitus that causes pathogenic damage to the retina. Particularly, the proliferative diabetic retinopathy (PDR) state can cause abnormal angiogenesis in the retina tissues and trigger the retina destruction in advanced stage. In the clinic, the symptoms during the initiation and progression of PDR are relatively unrecognizable. Therefore, various studies have focused on the pathogenesis of PDR. According to published literature, genetic contributions play an irreplaceable role in the initiation and progression of PDR. Although many computational methods, such as shortest path- and random walk with restart-based methods, have been applied in screening the potential pathogenic factors of PDR, advanced computational methods, which may provide essential supplements for previous ones, are still widely needed. In this study, a novel computational method was presented to infer novel PDR-associated genes. Different from previous methods, the method used in this work employed a different network algorithm, that is, the Laplacian heat diffusion algorithm. This algorithm was applied on the protein-protein interaction network reported in the STRING database. Three screening tests were performed to filter the most likely inferred genes. A total of 26 genes were accessed using the proposed method. Compared with the two previous predictions, most of the identified genes were novel, and only one gene was shared. Several inferred genes, such as CSF3, COL18A1, CXCR2, CCR1, FGF23, CXCL11, and IL13, were related to the pathogenesis of PDR.

RNAseq-Based Prioritization Revealed COL6A5, COL8A1, COL10A1 and MIR146A as Common and Differential Susceptibility Biomarkers for Psoriasis and Psoriatic Arthritis: Confirmation from Genotyping Analysis of 1417 Italian Subjects.

Psoriasis (Ps) and Psoriatic Arthritis (PsA) are characterized by a multifactorial etiology, involving genetic and environmental factors. The present study aimed to investigate polymorphisms (SNPs) within genes involved in extracellular matrix and cell homeostasis and microRNA genes as susceptibility biomarkers for Ps and PsA. Bioinformatic analysis on public RNA-seq data allowed for selection of rs12488457 (A/C, COL6A5), rs13081855 (G/T, COL8A1), rs3812111 (A/T, COL10A1) and rs2910164 (C/G, MIR146A) as candidate biomarkers. These polymorphisms were analyzed by Real-Time PCR in a cohort of 1417 Italian patients (393 Ps, 424 PsA, 600 controls). Statistical and bioinformatic tools were utilized for assessing the genetic association and predicting the effects of the selected SNPs. rs12488457, rs13081855 and rs2910164 were significantly associated with both Ps (p = 1.39 × 10-8, p = 4.52 × 10-4, p = 0.04, respectively) and PsA (p = 5.12 × 10-5, p = 1.19 × 10-6, p = 0.01, respectively). rs3812111, instead, was associated only with PsA (p = 0.005). Bioinformatic analysis revealed common and differential biological pathways involved in Ps and PsA. COL6A5 and COL8A1 take part in the proliferation and angiogenic pathways which are altered in Ps/PsA and contribute to inflammation together with MIR146A. On the other hand, the exclusive association of COL10A1 with PsA highlighted the specific involvement of bone metabolism in PsA.

Serum Endostatin Is a Novel Marker for COPD Associated with Lower Lung Function, Exacerbation and Systemic Inflammation.

Backgrounds and Aims: It is well known that angiogenesis contributes to the progression of chronic obstructive pulmonary disease (COPD) by initiating the remodeling of bronchial vasculature. However, the specific molecular mechanisms are incompletely understood. This research aimed to explore whether endostatin, a member of endogenous antiangiogenic proteins, is a biomarker in COPD and plays a role in the angiogenesis of COPD. Methods: 100 stable COPD patients, 130 patients with acute exacerbation (AECOPD) and 68 healthy volunteers were recruited in this research. Lung function test was conducted in the healthy people and stable COPD patients. Serum endostatin, C-reactive protein (CRP) and vascular endothelial growth factor (VEGF) of all the subjects were measured by Human Magnetic Luminex Screening Assay. Results: Serum endostatin level was significantly higher in stable COPD compared with healthy control and even more in AECOPD patients (P<0.001). Besides, stable COPD patients with frequent exacerbation (≥2 exacerbations per year) in the last 1 year had a higher concentration of endostatin in the circulation compared to the patients with less exacerbation (P=0.037). Furthermore, circulatory endostatin was negatively associated with forced expiratory volume in 1 s % predicted (FEV1%pre), an index of lung function in the stable COPD group (P=0.009). Finally, endostatin was positively correlated to serum CRP in COPD group (including stable and AECOPD) (P=0.005) and all the subjects (P<0.001), but only associated with VEGF in the total participants (P=0.002), not in the COPD group. Conclusion: These results suggested that endostatin is a biomarker for COPD and associated with lower lung function, exacerbation, and systemic inflammation. Endostatin potentially contributes to the pathogenesis of COPD.

Functional Impact of Human Genetic Variants of COL18A1/Endostatin on Pulmonary Endothelium.

Pulmonary arterial hypertension (PAH) is an incurable disease characterized by disordered and dysfunctional angiogenesis leading to small-vessel loss and an obliterative vasculopathy. The pathogenesis of PAH is not fully understood, but multiple studies have demonstrated links between elevated angiostatic factors, disease severity, and adverse clinical outcomes. ES (endostatin), one such circulating angiostatic peptide, is the cleavage product of the proteoglycan COL18A1 (collagen α1[XVIII] chain). Elevated serum ES is associated with increased mortality and disease severity in PAH. A nonsynonymous variant of ES (aspartic acid-to-asparagine substitution at amino acid 104; p.D104N) is associated with differences in PAH survival. Although COL18A1/ES expression is markedly increased in remodeled pulmonary vessels in PAH, the impact of ES on pulmonary endothelial cell (PEC) biology and molecular contributions to PAH severity remain undetermined. In the present study, we characterized the effects of exogenous ES on human PEC biology and signaling. We demonstrated that ES inhibits PEC migration, proliferation, and cell survival, with significant differences between human variants, indicating that they are functional genetic variants. ES promotes proteasome-mediated degradation of the transcriptional repressor ID1, increasing expression and release of TSP-1 (thrombospondin 1). ES inhibits PEC migration via an ID1/TSP-1/CD36-dependent pathway, in contrast to proliferation and apoptosis, which require both CD36 and CD47. Collectively, the data implicate ES as a novel negative regulator of ID1 and an upstream propagator of an angiostatic signal cascade converging on CD36 and CD47, providing insight into the cellular and molecular effects of a functional genetic variant linked to altered outcomes in PAH.

Genetic polymorphisms in collagen-related genes are associated with pelvic organ prolapse.

OBJECTIVE: Pelvic organ prolapse (POP) is a common health issue that has a profound negative influence on women's quality of life. Genetic susceptibility to POP has been increasingly investigated. In this study, we assessed the single-nucleotide polymorphisms (SNPs) of six collagen-related genes (COL14A1, COL5A1, COL4A2, COL3A1, COL1A1, and COL18A1) and the genetic association with POP in Chinese women. METHODS: We performed a candidate gene association study of case women (n = 48) with stage III and IV prolapse and control women (n = 48) without prolapse. A target region sequencing approach was used to identify the SNPs in collagen-related genes. The association between SNPs and POP was examined by Fisher exact tests for unadjusted model and logistic regression analysis adjusted for delivery and pregnancy. RESULTS: There was a significant association between COL14A1 SNPs (rs4870723, rs2305600, and rs2305598; P = 0.013, 0.019, and 0.028, respectively), a COL5A1 SNP (rs3827852; P = 0.016), and COL4A2 SNPs (rs76425569, rs388222, and rs2281968; P = 0.049 for the three, and rs445348, P = 0.040) and POP, respectively. Although there was no significant association between the COL3A1 SNP and POP, there was a trend toward significance for COL14A1 SNP (rs2305603), COL4A2 SNP (rs74941798), two COL1A1 SNPs (rs2586488 and rs2249492) and three COL18A1 SNPs (rs1050351, rs56335679, and rs55690336), and POP. CONCLUSION: We are the first to evaluate the relationship between COL14A1, COL5A1, and COL4A2 polymorphisms and POP, besides COL3A1, COL1A1, and COL18A1, which have been reported previously. We found several candidate SNPs that were significantly associated with prolapse in Chinese women. Our results provide new evidence for further investigation of the involvement of these potential genes in the etiology of POP.

Stem cells from human cardiac adipose tissue depots show different gene expression and functional capacities.

BACKGROUND: The composition and function of the adipose tissue covering the heart are poorly known. In this study, we have investigated the epicardial adipose tissue (EAT) covering the cardiac ventricular muscle and the EAT covering the left anterior descending artery (LAD) on the human heart, to identify their resident stem cell functional activity. METHODS: EAT covering the cardiac ventricular muscle was isolated from the apex (avoiding areas irrigated by major vessels) of the heart (ventricular myocardium adipose tissue (VMAT)) and from the area covering the epicardial arterial sulcus of the LAD (PVAT) in human hearts excised during heart transplant surgery. Adipose stem cells (ASCs) from both adipose tissue depots were immediately isolated and phenotypically characterized by flow cytometry. The different behavior of these ASCs and their released secretome microvesicles (MVs) were investigated by molecular and cellular analysis. RESULTS: ASCs from both VMAT (mASCs) and the PVAT (pASCs) were characterized by the expression of CD105, CD44, CD29, CD90, and CD73. The angiogenic-related genes VEGFA, COL18A1, and TF, as well as the miRNA126-3p and miRNA145-5p, were analyzed in both ASC types. Both ASCs were functionally able to form tube-like structures in three-dimensional basement membrane substrates. Interestingly, pASCs showed a higher level of expression of VEGFA and reduced level of COL18A1 than mASCs. Furthermore, MVs released by mASCs significantly induced human microvascular endothelial cell migration. CONCLUSION: Our study indicates for the first time that the resident ASCs in human epicardial adipose tissue display a depot-specific angiogenic function. Additionally, we have demonstrated that resident stem cells are able to regulate microvascular endothelial cell function by the release of MVs.

Type XVIII Collagen Modulates Keratohyalin Granule Formation and Keratinization in Oral Mucosa.

Epithelial keratinization involves complex cellular modifications that provide protection against pathogens and chemical and mechanical injuries. In the oral cavity, keratinized mucosa is also crucial to maintain healthy periodontal or peri-implant tissues. In this study, we investigated the roles of type XVIII collagen, a collagen-glycosaminoglycan featuring an extracellular matrix component present in the basement membrane, in oral mucosal keratinization. Histological analysis of keratinized and non-keratinized oral mucosa showed that type XVIII collagen was highly expressed in keratinized mucosa. Additionally, a 3D culture system using human squamous carcinoma cells (TR146) was used to evaluate and correlate the changes in the expression of type XVIII collagen gene, COL18A1, and epithelial keratinization-related markers, e.g., keratin 1 (KRT1) and 10 (KRT10). The results showed that the increase in COL18A1 expression followed the increase in KRT1 and KRT10 mRNA levels. Additionally, loss-of-function analyses using silencing RNA targeting COL18A1 mRNA and a Col18-knockout (KO) mouse revealed that the absence of type XVIII collagen induces a dramatic decrease in KRT10 expression as well as in the number and size of keratohyalin granules. Together, the results of this study demonstrate the importance of type XVIII collagen in oral mucosal keratinization.

Genetic factors for idiopathic choroidal neovascularization.

Objective: The aim of this study was to investigate genetic factors associated with idiopathic choroidal neovascularization (ICNV). Methods: We conducted a case-control study including 69 cases with ICNV and 114 controls who underwent cataract surgery. Single nucleotide polymorphisms (SNPs) from genes reported to be related to AMD, CNV and uveitis were selected for this study. Results: In an univariate analysis, the rs669676 SNP located in the COL8A1 gene was associated with the proportion of people who has idiopathic CNV ( X2 = 9.3453, corrected p-value = 0.1). For the rs669676 SNP, minor allele homozygotes, in the dominant model of genotype analysis (GG versus AA-GA), it showed significant differences in the ICNV group vs controls (p = .01, OR = 1.219 (95%CI: 1.04-1.429)). Conclusions: The rs669676 SNP located in the COL8A1 gene may contribute to a genetic susceptibility for ICNV.

Atopic Eczema: Genetic Analysis of COL6A5, COL8A1, and COL10A1 in Mediterranean Populations.

To date, the genes associated with susceptibility to Atopic Eczema (AE) are mainly implicated in immunity, inflammation, and maintenance of skin barrier. Little is known about the possible relationship between genes modulating Extra-Cellular Matrix (ECM) and AE etiopathogenesis. In this regard, the primary objective of the present study has been the investigation of susceptibility biomarkers localized within genes encoding collagen proteins. Several studies have shown that polymorphisms within the genes encoding such proteins may generate abnormal connective tissues, making them more susceptible to mechanical stress, loss of epidermal integrity, and aging. We therefore decided to investigate three polymorphisms located in COL6A5, COL8A1, and COL10A1 as potential susceptibility biomarkers for AE in a cohort of 1470 subjects of Mediterranean origin. The genes of interest have been selected considering that the ECM and immune/inflammatory response are strongly dysregulated in AE and other complex disorders. The study confirmed that the susceptibility to AE depends on a complex interaction between latitude, geographical localization, and the differential distribution of genetic variants among populations exposed to similar environmental factors.

RAD51B (rs8017304 and rs2588809), TRIB1 (rs6987702, rs4351379, and rs4351376), COL8A1 (rs13095226), and COL10A1 (rs1064583) Gene Variants with Predisposition to Age-Related Macular Degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is a progressive neurodegenerative disease of a central part of the neural retina (macula) and a leading cause of blindness in elderly people. While it is known that the AMD is a multifactorial disease, genetic factors involved in lipid metabolism, inflammation, and neovascularization are currently being widely studied in genome-wide association studies (GWAS). The aim of our study was to evaluate the impact of new single nucleotide polymorphisms (SNPs) in RAD51B, TRIB1, COL8A1, and COL10A1 genes on AMD development. METHODS: Case-control study involved 254 patients diagnosed with early AMD, 244 patients with exudative AMD, and 942 control subjects. The genotyping of RAD51B (rs8017304 and rs2588809), TRIB1 (rs6987702, rs4351379, and rs4351376), COL8A1 (rs13095226), and COL10A1 (rs1064583) was carried out using TaqMan assays by a real-time polymerase chain reaction (RT-PCR) method. RESULTS: Statistically significant difference was found in genotype (TT, TC, and CC) distribution of COL8A1 rs13095226 between exudative AMD and control groups (60.2%, 33.6%, and 6.1% vs. 64.9%, 32.3%, and 2.9%, respectively, p = 0.036). Also, comparing with TT+TC, rs13095226 CC genotype was associated with 3.5-fold increased odds of exudative AMD development (OR = 3.540; 95% CI: 1.415-8.856; p = 0.007). CONCLUSION: Our study revealed a strong association between a variant in COL8A1 (rs13095226) and exudative AMD development.