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Background: Lung adenocarcinoma (LUAD) is a highly aggressive and rapidly fatal malignancy worldwide. Collagen XVII (COL17A1) has been implicated in various protumorigenic processes. However, the functions and mechanisms of COL17A1 in LUAD progression still remain elusive. Methods: COL17A1 and ubiquitin‐specific protease 22 (USP22) mRNA analysis was performed by quantitative PCR, and their protein levels were detected by immunoblotting and immunohistochemistry. The functional influence was evaluated by determining cell viability, proliferation, apoptosis, invasion, migration, and ferroptosis in vitro, as well as xenograft growth in vivo. Co‐immunoprecipitation (Co‐IP) and IP experiments were used to examine the USP22/COL17A1 interaction and COL17A1 deubiquitination. Cycloheximide treatment was used to analyze COL17A1 protein stability. Results: COL17A1 and USP22 were upregulated in human LUAD tissues and cell lines. Functionally, COL17A1 knockdown acted for the suppression of LUAD cell growth, invasion, and migration as well as promotion of cell apoptosis and ferroptosis in vitro. COL17A1 knockdown could diminish the tumorigenicity of LUAD cells in vivo. Mechanistically, USP22 stabilized and upregulated COL17A1 by enhancing the deubiquitination of COL17A1. Additionally, reexpression of COL17A1 could reverse USP22 silencing‐induced phenotype changes of LUAD cells in vitro. Conclusion: Our findings demonstrate that USP22‐stabilized COL17A1 possesses oncogenic activity in LUAD. We propose that USP22 and COL17A1 would be potential targets for the establishment of therapeutic approaches against LUAD. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Lung adenocarcinoma (LUAD) is a highly aggressive and rapidly fatal malignancy worldwide. Collagen XVII (COL17A1) has been implicated in various protumorigenic processes. However, the functions and mechanisms of COL17A1 in LUAD progression still remain elusive. Methods COL17A1 and ubiquitin‐specific protease 22 (USP22) mRNA analysis was performed by quantitative PCR, and their protein levels were detected by immunoblotting and immunohistochemistry. The functional influence was evaluated by determining cell viability, proliferation, apoptosis, invasion, migration, and ferroptosis in vitro, as well as xenograft growth in vivo. Co‐immunoprecipitation (Co‐IP) and IP experiments were used to examine the USP22/COL17A1 interaction and COL17A1 deubiquitination. Cycloheximide treatment was used to analyze COL17A1 protein stability. Results COL17A1 and USP22 were upregulated in human LUAD tissues and cell lines. Functionally, COL17A1 knockdown acted for the suppression of LUAD cell growth, invasion, and migration as well as promotion of cell apoptosis and ferroptosis in vitro. COL17A1 knockdown could diminish the tumorigenicity of LUAD cells in vivo. Mechanistically, USP22 stabilized and upregulated COL17A1 by enhancing the deubiquitination of COL17A1. Additionally, reexpression of COL17A1 could reverse USP22 silencing‐induced phenotype changes of LUAD cells in vitro. Conclusion Our findings demonstrate that USP22‐stabilized COL17A1 possesses oncogenic activity in LUAD. We propose that USP22 and COL17A1 would be potential targets for the establishment of therapeutic approaches against LUAD.

Amelogenesis imperfecta (AI) represents a group of clinically and genetically heterogeneous disorders that affect enamel formation and mineralization. Although AI is commonly considered a monogenic disorder, digenic inheritance is rarely reported. In this study, we recruited two nonconsanguineous Chinese families exhibiting diverse phenotypes of enamel defects among affected family members. Digenic variants were discovered in both probands. In family 1, the proband inherited a paternal frameshift variant in LAMA3 (NM_198129.4:c.3712dup) and a maternal deletion encompassing the entire AMELX gene. This resulted in a combined hypoplastic and hypomineralized AI phenotype, which was distinct from the parents' manifestations. In family 2, whole‐exome sequencing analysis revealed the proband carried a maternal heterozygous splicing variant in COL17A1 (NC_000010.11 (NM_000494.3): c.4156 + 2dup) and compound heterozygous variants in RELT (paternal: NM_032871.4:c.260A > T; maternal: NM_032871.4:c.521 T > G). These genetic changes caused the abundant irregular enamel defects observed in the proband, whereas other affected family members carrying heterozygous variants in both COL17A1 and RELT displayed only horizontal grooves as their phenotype. The pathogenicity of the novel COL17A1 splice site variant was confirmed through RT‐PCR and minigene assay. This study enhances our understanding by highlighting the potential association between the co‐occurrence of variants in two genes and variable phenotypes observed in AI patients. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) is the most abundant and reversible modification occurring in eukaryotic mRNAs, however, its functions in mammalian epidermal development are still not fully elucidated. To explore the role of METTL14 (Methyltransferase like 14), one of the m6A methyltransferases, in maintaining epidermal homeostasis. We constructed mice with Mettl14 -inactivation in the epidermal basal cells. The phenotype was explored by H&E staining and immunofluorescence staining. To explore the underlying mechanisms, we performed RNA-seq, Ribosome profiling and MeRIP-seq on wild-type and Mettl14 -inactivation epidermal keratinocytes. Moreover, HaCaT cells were used for in vitro validation. Inactivation of Mettl14 in murine epidermis led to transient thicker epidermis and exhaustion of the epidermal stem cell pool. Interestingly, we found that the mRNA of type XVII collagen (Col17a1), integrin β4 (Itgβ4) and α6 (Itgα6) had m6A modifications, and the proteins expression were decreased in Mettl14 -inactivated epidermis. Furthermore, in epidermis-specific Mettl4 -inactivated mice, the epidermis was detached from the dermis and presented a phenotype similar to junctional epidermolysis bullosa (JEB), which may result from hemidesmosomes damage (decrease of COL17A1, ITGB4 and ITGA6). Knockdown of Mettl14 in HaCaT cells impaired the self-renewal and decreased the protein level of COL17A1, ITGB4 and ITGA6 and Itgβ4 knockdown inhibited colony formation. Our study highlighted the role of METTL14 in the maintenance of epidermal homeostasis and identified its critical role through m6A-mediated translational inhibition of Col17a1, Itgβ4 and Itgα6. Our study suggested that METTL14 may be a potential therapeutic target for the treatment of hemidesmosomes-deficient diseases, such as JEB. • Mettl14 inactivation in murine epidermis led to transient thicker epidermis and exhaustion of the epidermal stem cell pool. • Mettl14 inactivation led to a junctional epidermolysis bullosa (JEB)-like phenotype (dermal-epidermal detachment). • METTL14 may regulate epidermal homeostasis through m6A methylation modifications of Col17a1, Itgβ4 and Itgα6. [ABSTRACT FROM AUTHOR]

Human skin is the most widespread and abundant type of tissue in the human body. With the passage of time, most of our organs, including a substantial part of the skin, tend to undergo a gradual thinning or decrease in size. As we age, there is a gradual and progressive reduction in the thickness of both the epidermis and dermis layers of our skin. This is primarily attributed to the decline of epidermal stem cells and the loss of dermal collagen, which is the most abundant protein in the human body. Age-related alterations of the epidermis and dermis impair skin structure/function and create a tissue microenvironment that promotes age-related skin diseases, such as impaired skin barrier, delayed wound healing, and skin cancer development. This review will examine the current body of literature pertaining to our knowledge of skin epidermal and dermal aging. • As skin aging is inevitable, the visible signs of aging skin have a significant impact on our social and visual interactions. • Alterations in the skin due to aging give rise to a microenvironment closely associated with various skin conditions. • The process of skin aging extends beyond cosmetic considerations and plays a crucial role in age-related skin problems. • This review aims to elucidate our current understanding of the aging process in the epidermis and dermis of the skin. [ABSTRACT FROM AUTHOR]

Hereditary conditions that affect tooth enamel in quantity and/or quality are called amelogenesis imperfecta (AI). AI can occur as an isolated condition or as a symptom of a syndrome. An OMIM search with the term "AI" yielded 79 result entries. Mutations in the same gene cause syndromic or non-syndromic AI, depending on the nature of the mutations. In this study, we recruited two AI families and performed mutational analysis using whole-exome sequencing. The proband of family 1, with hypoplastic pitted AI and mild localized atopic dermatitis, had compound heterozygous COL17A1 mutations (paternal NM_000494.4: c.3598G>T, p.Asp1200Tyr and maternal c.1700G>A, p.Gly567Glu). The proband of family 2, with hypoplastic pitted AI and Jervell and Lange-Nielsen syndrome, had a recurrent LAMB3 mutation (NM_000228.3: c.3463_3475del, p.(Glu1155Thrfs*51)) in addition to compound heterozygous mutations in the KCNQ1 gene. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The presence of more than one genetic/genomic disorder is not uncommon. It is therefore essential to continuously consider new signs and symptoms over time. Administration of gene therapy could be extremely difficult in particular situations. A 9‐month‐old boy presented to our department for evaluation of developmental delay. We found that he was affected by intermediate junctional epidermolysis bullosa (COL17A1, c.3766 + 1G > A, homozygous), Angelman syndrome (5,5 Mb deletion of 15q11.2‐q13.1), and autosomal recessive deafness type 57 (PDZD7, c.883C > T, homozygous). [ABSTRACT FROM AUTHOR]

Copyright of Journal of China Medical University is the property of Journal of China Medical University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Key Clinical Message The presence of more than one genetic/genomic disorder is not uncommon. It is therefore essential to continuously consider new signs and symptoms over time. Administration of gene therapy could be extremely difficult in particular situations. Abstract A 9‐month‐old boy presented to our department for evaluation of developmental delay. We found that he was affected by intermediate junctional epidermolysis bullosa (COL17A1, c.3766 + 1G > A, homozygous), Angelman syndrome (5,5 Mb deletion of 15q11.2‐q13.1), and autosomal recessive deafness type 57 (PDZD7, c.883C > T, homozygous).

Junctional epidermolysis bullosa (JEB) is a severe blistering skin disease caused by mutations in genes encoding structural proteins essential for skin integrity. In this study, we developed a cell line suitable for gene expression studies of the JEB-associated COL17A1 encoding type XVII collagen (C17), a transmembrane protein involved in connecting basal keratinocytes to the underlying dermis of the skin. Using the CRISPR/Cas9 system of Streptococcus pyogenes we fused the coding sequence of GFP to COL17A1 leading to the constitutive expression of GFP-C17 fusion proteins under the control of the endogenous promoter in human wild-type and JEB keratinocytes. We confirmed the accurate full-length expression and localization of GFP-C17 to the plasma membrane via fluorescence microscopy and Western blot analysis. As expected, the expression of GFP-C17mut fusion proteins in JEB keratinocytes generated no specific GFP signal. However, the CRISPR/Cas9-mediated repair of a JEB-associated frameshift mutation in GFP-COL17A1mut-expressing JEB cells led to the restoration of GFP-C17, apparent in the full-length expression of the fusion protein, its accurate localization within the plasma membrane of keratinocyte monolayers as well as within the basement membrane zone of 3D-skin equivalents. Thus, this fluorescence-based JEB cell line provides the potential to serve as a platform to screen for personalized gene editing molecules and applications in vitro and in appropriate animal models in vivo. [ABSTRACT FROM AUTHOR]

Abstract Background Uniparental disomy (UPD) is a condition in which both chromosomes are inherited from the same parent, except for imprinting disorders. Uniparental isodisomy (UPiD) may result in a homozygous variant contributing to an autosomal recessive disorder in the offspring of a heterozygous carrier. Junctional epidermolysis bullosa intermediate (JEB intermediate) is an autosomal recessive inherited disease that is associated with a series of gene variants, including those of COL17A1. Case presentation We report the first case of complete paternal UPiD of chromosome 10 harbouring a novel homozygous variant in COL17A1: c.1880(exon23)delG (p.G627Afs*56). This variant led to the clinical phenotype of junctional epidermolysis bullosa intermediate in a 5-year-old child. Trio-whole exome sequencing (Trio-WES) and in silico data analysis were used for variant identification, Sanger sequencing was performed for variant validation, and pathological examination was performed as the gold standard for phenotype confirmation. Conclusions We recommend the use of WES as a first-tier test for the diagnosis of epidermolysis bullosa, especially for paediatric patients. Moreover, UPD events should be detected and analysed routinely through WES data in the future.

This study aimed to determine the role of COL17A1 in tumor progression and predict the prognosis of pancreatic cancer (PC). RNA-seq data from The Cancer Genome Atlas and Genotype-Tissue Expression were analyzed using bioinformatics methods. "Limma" package was used to screen differentially expressed genes (DEGs). Prognostic-associated data were further analyzed using univariate Cox regression and verified using the GSE28375 and GSE62452 datasets. Protein-protein interaction (PPI) network analysis was integrated to screen for hub genes. In vitro quantitative real-time PCR (qPCR) and western blotting were used to detect gene expression. The functional attributes of PC cells were verified by wound healing assays, migration and invasion assays, Cell Counting Kit 8 (CCK8), and 5-ethynyl-2′-deoxyuridine (EdU) assay. On analyzing PC data, 4637 DEGs were identified. Of these, 2399 genes were upregulated and 2238 were downregulated. Through PPI network analysis, we identified that COL17A1 expression was highly correlated with poor prognosis of patients with PC. Functional attribute assays in the in vitro study showed that COL17A1 knockdown inhibited PC cell proliferation, migration, and invasion. According to our results, COL17A1 promotes PC cell proliferation, migration, and invasion mediated by the epithelial-mesenchymal transition (EMT) pathway. Thus, COL17A1 could be used as a prognostic marker in PC. • COL17A1 has higher expression levels in pancreatic cancer tissue than normal pancreatic tissue. • COL17A1 significantly promotes pancreatic cancer cells growth, migration and invasion via regulating EMT pathways. • COL17A1 is a valuable indicator to assess prognosis, and providedes a promising therapeutic target for pancreatic cancer. [ABSTRACT FROM AUTHOR]

ADAM10 is A Disintegrin And Metalloproteinase (ADAM) family member that is membrane bound with its catalytic domain present on the cell surface. It is a sheddase that cleaves anchored cell surface proteins to shed them from the cell surface. ADAM10 can cleave at least a hundred different proteins and is expressed in most tissues of the body. ADAM10 is best characterized for its role in Notch signaling. Interestingly, ADAM10 is transported to specific sites on the cell surface by six different tetraspanins. Although the mechanism is not clear, tetraspanins can regulate ADAM10 substrate specificity, which likely contributes to the diversity of ADAM10 substrates. In developing mouse teeth, ADAM10 is expressed in the stem cell niche and subsequently in pre-ameloblasts and then secretory stage ameloblasts. However, once ameloblasts begin transitioning into the maturation stage, ADAM10 expression abruptly ceases. This is exactly when ameloblasts stop their movement that extends enamel crystallites and when the enamel layer reaches its full thickness. ADAM10 may play an important role in enamel development. ADAM10 can cleave cadherins and other cell-cell junctions at specific sites where the tetraspanins have transported it and this may promote cell movement. ADAM10 can also cleave the transmembrane proteins COL17A1 and RELT. When either COL17A1 or RELT are mutated, malformed enamel may occur in humans and mice. So, ADAM10 may also regulate these proteins that are necessary for proper enamel development. This mini review will highlight ADAM10 function, how that function is regulated by tetraspanins, and how ADAM10 may promote enamel formation.

Collagen 17A1 (COL17A1) is a transmembrane structural component of the hemidesmosome that mediate adhesion of keratinocytes to the underlying membrane. Recent work in mouse showed that COL17A1 deficiency leads to premature skin aging. Although the role COL17A1 in skin aging is becoming recognized in mouse models, its connection to human skin natural aging/photoaging/ultraviolet (UV)-irradiated human skin has received little attention. To determine COL17A1 expression in naturally aged and photoaged as well as acutely UV irradiated human skin, skin samples were obtained from: (1) young (N = 10, 26.7±1.3 years) and aged (N = 10, 84.0 ± 1.7 years) sun-protected buttock skin; (2) photoaged extensor forearm and subject matched sun-protected underarm skin (N = 6, 56.0 ± 3.4 years); (3) solar-simulated UV-irradiated buttock skin (N = 6, 51.2 ± 3.6 years). COL17A1 levels were determined by immunohistology and RT-PCR, and the potential role of COL17A1 in epidermal aging was investigated by immunostaining of the marker for interfollicular epidermal stem cells and keratinocytes proliferation. We found that COL17A1 is specifically expressed in interfollicular epidermal stem cell niches, and that significantly reduced in naturally aged, photoaged, and acute UV-irradiated human skin in vivo. COL17A1 is identified as keratinocyte-specific collagen, and UV irradiation significantly downregulates COL17A1 expression in keratinocytes. Reduced expression of COL17A1 is positively correlated with impaired regeneration of keratinocytes and reduced dermal-epidermal junction as well as thin epidermis in aged human skin (epidermal aging). We also confirmed that keratinocyte-specific integrin β4 (ITGB4), which interacts with COL17A1, is reduced in aged human skin. Mechanistically, we found that matrix metalloproteinases (MMPs) are responsible for UV-mediated COL17A1 degradation in both in vitro keratinocytes and in vivo mouse skin. These data suggest the possible links between reduced expression of COL17A1 and epidermal aging in human skin. [ABSTRACT FROM AUTHOR]

BackgroundEpidermolysis bullosa (EB), a severe genetic disorder characterized by blister formation in skin, is caused by mutations in genes encoding dermal-epidermal junction proteins that function to hold the skin layers together. CRISPR/Cas9-induced homology-directed repair (HDR) represents a promising tool for editing causal mutations in COL17A1 in the treatment of junctional epidermolysis bullosa (JEB).MethodsIn this study, we treated primary type XVII collagen (C17)-deficient JEB keratinocytes with either Cas9 nuclease or nickase (Cas9n) ribonucleoproteins (RNP) and a single-stranded oligonucleotide (ssODN) HDR template in order to correct a causal pathogenic frameshift mutation within the COL17A1 gene.ResultsAs analyzed by next-generation sequencing of RNP-nucleofected keratinocytes, we observed an HDR efficiency of ∼38% when cells were treated with the high-fidelity Cas9 nuclease, a mutation-specific sgRNA, and an ssODN template. The combined induction of end-joining repair and HDR-mediated pathways resulted in a C17 restoration efficiency of up to 60% as assessed by flow cytometry. Furthermore, corrected JEB keratinocytes showed a significantly increased adhesive strength to laminin-332 and an accurate deposition of C17 along the basement membrane zone (BMZ) upon differentiation into skin equivalents.ConclusionHere we present a gene editing approach capable of reducing end joining-generated repair products while increasing the level of seamless HDR-mediated gene repair outcomes, thereby providing a promising CRISPR/Cas9-based gene editing approach for JEB.

Tumor dormancy is the underpinning for cancer relapse and chemoresistance, leading to massive cancer-related death in colorectal cancer (CRC). However, our comprehension of the mechanisms dictating tumor dormancy and strategies for eliminating dormant tumor cells remains restricted. In this study, we identified that collagen XVII (COL17A1), a hemidesmosomal transmembrane protein, can promote the dormancy of CRC cells. The upregulation of COL17A1 was observed to prolong quiescence periods and diminish drug susceptibility of CRC cells. Mechanistically, COL17A1 acts as a scaffold, enhancing the crosstalk between mTORC2 and Akt, thereby instigating the mTORC2-mediated dormant signaling. Notably, the activation of mTORC2 is contingent upon the intracellular domain of COL17A1, regardless of its ectodomain shedding. Our findings underscore a pivotal role of the COL17A1-mTORC2 axis in CRC dormancy, suggesting that mTORC2-specific inhibitors may hold therapeutic prospects for the eradication of dormant tumor cells. • COL17A1 drives CRC cells into dormancy. • COL17A1 acts as a scaffold, enhancing the crosstalk between mTORC2 and Akt. • mTORC2 is critical for maintaining the dormancy induced by COL17A1. • The ectodomain shedding of COL17A1 does not affect its ability to induce dormancy. [ABSTRACT FROM AUTHOR]

Background: Uniparental disomy (UPD) is a condition in which both chromosomes are inherited from the same parent, except for imprinting disorders. Uniparental isodisomy (UPiD) may result in a homozygous variant contributing to an autosomal recessive disorder in the offspring of a heterozygous carrier. Junctional epidermolysis bullosa intermediate (JEB intermediate) is an autosomal recessive inherited disease that is associated with a series of gene variants, including those of COL17A1. Case presentation: We report the first case of complete paternal UPiD of chromosome 10 harbouring a novel homozygous variant in COL17A1: c.1880(exon23)delG (p.G627Afs*56). This variant led to the clinical phenotype of junctional epidermolysis bullosa intermediate in a 5-year-old child. Trio-whole exome sequencing (Trio-WES) and in silico data analysis were used for variant identification, Sanger sequencing was performed for variant validation, and pathological examination was performed as the gold standard for phenotype confirmation. Conclusions: We recommend the use of WES as a first-tier test for the diagnosis of epidermolysis bullosa, especially for paediatric patients. Moreover, UPD events should be detected and analysed routinely through WES data in the future. [ABSTRACT FROM AUTHOR]

Copyright of Detergent & Cosmetics is the property of Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Junctional epidermolysis bullosa (JEB) is a rare autosomal recessive genodermatosis with a broad spectrum of phenotypes. Current genotype-phenotype paradigms are insufficient to accurately predict JEB subtype and characteristics from genotype, particularly for splice site variants, which account for over a fifth of disease-causing variants in JEB. This study evaluated the genetic and clinical findings from a JEB cohort, investigating genotype-phenotype correlations through bioinformatic analyses and comparison with previously reported variants. Eighteen unique variants in LAMB3, LAMA3, LAMC2, or COL17A1 were identified from 17 individuals. Seven had severe JEB, 9 had intermediate JEB, and 1 had laryngo-onycho-cutaneous syndrome. Seven variants were previously unreported. Deep phenotyping was completed for all intermediate JEB cases and demonstrated substantial variation between individuals. Splice site variants underwent analysis with SpliceAI, a state-of-the-art artificial intelligence tool, to predict resultant transcripts. Predicted functional effects included exon skipping and cryptic splice site activation, which provided potential explanations for disease severity and in most cases correlated with laminin-332 immunofluorescence. RT-PCR was performed for 1 case to investigate resultant transcripts produced from the splice site variant. This study expands the JEB genomic and phenotypic landscape. Artificial intelligence tools show potential for predicting the functional effects of splice site variants and may identify candidates for confirmatory laboratory investigation. Investigation of RNA transcripts will help to further elucidate genotype-phenotype correlations for novel variants., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Summary: Eye colour genetics have been extensively studied in humans since the rediscovery of Mendel's laws. This trait was first interpreted using simplistic genetic models but soon it was realised that it is more complex. In this study, we analysed eye colour variability in a Large White pig population (n = 897) and report the results of GWASs based on several comparisons including pigs having four main eye colour categories (three with both pigmented eyes of different brown grades: pale, 17.9%; medium, 14.8%; and dark, 54.3%; another one with both eyes completely depigmented, 3.8%) and heterochromia patterns (heterochromia iridis – depigmented iris sectors in pigmented irises, 3.2%; heterochromia iridum – one whole eye iris of depigmented phenotype and the other eye with the iris completely pigmented, 5.9%). Pigs were genotyped with the Illumina PorcineSNP60 BeadChip and GEMMA was used for the association analyses. The results indicated that SLC45A2 (on chromosome 16, SSC16), EDNRB (SSC11) and KITLG (SSC5) affect the different grades of brown pigmentation of the eyes, the bilateral eye depigmentation defect and the heterochromia iridis defect recorded in this white pig population respectively. These genes are involved in several mechanisms affecting pigmentation. Significant associations for the eye depigmented patterns were also identified for SNPs on two SSC4 regions (including two candidate genes: NOTCH2 and PREX2) and on SSC6, SSC8 and SSC14 (including COL17A1 as candidate gene). This study provided useful information to understand eye pigmentation mechanisms, further valuing the pig as animal model to study complex phenotypes in humans. [ABSTRACT FROM AUTHOR]

Deficiency of DNA repair pathways drives the development of colorectal cancer. However, the role of the base excision repair (BER) pathway in colorectal cancer initiation remains unclear. This study shows that Nei-like DNA glycosylase 1 (NEIL1) is highly expressed in colorectal cancer (CRC) tissues and associated with poorer clinical outcomes. Knocking out neil1 in mice markedly suppresses tumorigenesis and enhances infiltration of CD8+ T cells in intestinal tumors. Furthermore, NEIL1 directly forms a complex with SATB2/c-Myc to enhance the transcription of COL17A1 and subsequently promotes the production of immunosuppressive cytokines in CRC cells. A NEIL1 peptide suppresses intestinal tumorigenesis in Apc Min/+ mice, and targeting NEIL1 demonstrates a synergistic suppressive effect on tumor growth when combined with a nuclear factor κB (NF-κB) inhibitor. These results suggest that combined targeting of NEIL1 and NF-κB may represent a promising strategy for CRC therapy. [Display omitted] • Upregulation of NEIL1 enhances CRC initiation • NEIL1 directly form a transcriptional complex with SATB2/c-Myc/RNAPII • NEIL1 promotes COL17A1 expression leading an immunosuppressive microenvironment in CRC • Inhibition of NEIL1 can sensitize CRC cells to cytotoxic T cells Cao et al. report that NEIL1 drives CRC initiation through promoting the transcriptional level of COL17A1 and cytokine production of CRC cells via directly forming a complex with SATB2/c-Myc/RNAPII, which provides a link between carcinogenic inducers like oxidative stress, inflammation, and CRC initiation. [ABSTRACT FROM AUTHOR]

Junctional epidermolysis bullosa (JEB) is a hereditary blistering disease caused by reduced dermal-epidermal adhesion due to deficiencies of one of the proteins, laminin-332, type XVII collagen, integrin α6β4 or integrin α3. Significant progress has been achieved in the development of therapies for EB, such as bone-marrow transplantation, local or systemic injections with fibroblasts or mesenchymal stromal cells, readthrough of premature termination codons, or exon skipping. These were tailored in particular for dystrophic EB, which is caused by type VII collagen deficiency and have not yet reached broad clinical practice. Recently, pioneering combined gene and stem cell therapy was successful in treating one boy with junctional EB. Beside these exclusive approaches, no specific therapy to amend the major clinical features, skin and mucosal blistering and non-healing wounds is available to date. Here we extend the mutational spectrum of junctional EB, provide a stratification of COL17A1 mutations and discuss potential molecular therapeutic approaches.

Background: Collagen XVII is most typically associated with human disease when biallelic COL17A1 variants (>230) cause junctional epidermolysis bullosa (JEB), a rare, genetically heterogeneous, mucocutaneous blistering disease with amelogenesis imperfecta (AI), a developmental enamel defect. Despite recognition that heterozygous carriers in JEB families can have AI, and that heterozygous COL17A1 variants also cause dominant corneal epithelial recurrent erosion dystrophy (ERED), the importance of heterozygous COL17A1 variants causing dominant non-syndromic AI is not widely recognised., Methods: Probands from an AI cohort were screened by single molecule molecular inversion probes or targeted hybridisation capture (both a custom panel and whole exome sequencing) for COL17A1 variants. Patient phenotypes were assessed by clinical examination and analyses of affected teeth., Results: Nineteen unrelated probands with isolated AI (no co-segregating features) had 17 heterozygous, potentially pathogenic COL17A1 variants, including missense, premature termination codons, frameshift and splice site variants in both the endo-domains and the ecto-domains of the protein. The AI phenotype was consistent with enamel of near normal thickness and variable focal hypoplasia with surface irregularities including pitting., Conclusion: These results indicate that COL17A1 variants are a frequent cause of dominantly inherited non-syndromic AI. Comparison of variants implicated in AI and JEB identifies similarities in type and distribution, with five identified in both conditions, one of which may also cause ERED. Increased availability of genetic testing means that more individuals will receive reports of heterozygous COL17A1 variants. We propose that patients with isolated AI or ERED, due to COL17A1 variants, should be considered as potential carriers for JEB and counselled accordingly, reflecting the importance of multidisciplinary care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Type XVII collagen (COL17) is a transmembranous protein that is mainly expressed in the epidermal basal keratinocytes. Epidermal‐dermal attachment requires COL17 expression at the hemidesmosomes of the epidermal basement membrane zone because congenital COL17 deficiency leads to junctional epidermolysis bullosa and acquired autoimmunity to COL17 induces bullous pemphigoid. Recently, in addition to facilitating epidermal‐dermal attachment, COL17 has been reported to serve as a niche for hair follicle stem cells, to regulate proliferation in the interfollicular epidermis and to be present along the non‐hemidesmosomal plasma membrane of epidermal basal keratinocytes. This review focuses on the physiological properties of COL17 in the epidermis, its role in maintaining stem cells and its association with signalling pathways. We propose possible solutions to unanswered questions in this field. [ABSTRACT FROM AUTHOR]

ABSTRACT Corneal dystrophies are a clinically and genetically heterogeneous group of inherited disorders that bilaterally affect corneal transparency. They are defined according to the corneal layer affected and by their genetic cause. In this study, we identified a dominantly inherited epithelial recurrent erosion dystrophy (ERED)-like disease that is common in northern Sweden. Whole-exome sequencing resulted in the identification of a novel mutation, c.2816C>T, p.T939I, in the COL17A1 gene, which encodes collagen type XVII alpha 1. The variant segregated with disease in a genealogically expanded pedigree dating back 200 years. We also investigated a unique COL17A1 synonymous variant, c.3156C>T, identified in a previously reported unrelated dominant ERED-like family linked to a locus on chromosome 10q23-q24 encompassing COL17A1. We show that this variant introduces a cryptic donor site resulting in aberrant pre-mRNA splicing and is highly likely to be pathogenic. Bi-allelic COL17A1 mutations have previously been associated with a recessive skin disorder, junctional epidermolysis bullosa, with recurrent corneal erosions being reported in some cases. Our findings implicate presumed gain-of-function COL17A1 mutations causing dominantly inherited ERED and improve understanding of the underlying pathology. [ABSTRACT FROM AUTHOR]

Disruption of cell adhesion plays a central role in dedifferentiation, invasion, and metastasis of various cancers. The desmosome and hemidesmosome are anchoring junctions that control cell-cell and cell-matrix adhesion, respectively. To clarify their contributions in mediating the biological properties of oral cancer, we immunohistochemically examined the expression of desmoglein 1 (DSG1), DSG2, DSG3, desmocollin 2 (DSC2), integrin beta 4 (ITGB4), laminin gamma chain 2 (LAMC2), and collagen type 17 alpha 1 (COL17A1) in 51 cases of oral squamous cell carcinoma. On normal oral epithelial cells, DSG1, DSG3, DSC2, and COL17A1 were expressed on the plasma membrane, while ITGB4 and mature LAMC2 were present at the basement membrane. In cancer, the expression of DSG1, DSG3, DSC2, and COL17A1 decreased and internalized to the cytoplasm. Cytoplasmic expression of DSG2, ITGB4, and LAMC2 was induced in the cancer cells facing to the stroma. We scored immunohistochemical expression and correlated this to clinicopathological parameters including histologic differentiation, pattern of invasion, and presence of lymph node metastasis. Decrease of DSG3 and DSC2 expression correlated with a more aggressive cancer phenotype: less differentiated and more invasive histologic features and a higher incidence of nodal metastasis. Lower COL17A1 and higher LAMC2 expression were also associated with a more aggressive phenotype. The present study demonstrates that aberrant expression and altered cellular localization of desmosomal and hemidesmosomal proteins are associated with aggressive clinicopathological features of oral cancer. This reinforces the notion that disturbance of the keratin-associated anchoring junctions confers aggressive features to cancer cells. [ABSTRACT FROM AUTHOR]

ADAM10 is A Disintegrin And Metalloproteinase (ADAM) family member that is membrane bound with its catalytic domain present on the cell surface. It is a sheddase that cleaves anchored cell surface proteins to shed them from the cell surface. ADAM10 can cleave at least a hundred different proteins and is expressed in most tissues of the body. ADAM10 is best characterized for its role in Notch signaling. Interestingly, ADAM10 is transported to specific sites on the cell surface by six different tetraspanins. Although the mechanism is not clear, tetraspanins can regulate ADAM10 substrate specificity, which likely contributes to the diversity of ADAM10 substrates. In developing mouse teeth, ADAM10 is expressed in the stem cell niche and subsequently in pre-ameloblasts and then secretory stage ameloblasts. However, once ameloblasts begin transitioning into the maturation stage, ADAM10 expression abruptly ceases. This is exactly when ameloblasts stop their movement that extends enamel crystallites and when the enamel layer reaches its full thickness. ADAM10 may play an important role in enamel development. ADAM10 can cleave cadherins and other cell-cell junctions at specific sites where the tetraspanins have transported it and this may promote cell movement. ADAM10 can also cleave the transmembrane proteins COL17A1 and RELT. When either COL17A1 or RELT are mutated, malformed enamel may occur in humans and mice. So, ADAM10 may also regulate these proteins that are necessary for proper enamel development. This mini review will highlight ADAM10 function, how that function is regulated by tetraspanins, and how ADAM10 may promote enamel formation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Shahid, Ikeda, Layana and Bartlett.)

Background: Epidermolysis bullosa (EB), a severe genetic disorder characterized by blister formation in skin, is caused by mutations in genes encoding dermal-epidermal junction proteins that function to hold the skin layers together. CRISPR/Cas9-induced homology-directed repair (HDR) represents a promising tool for editing causal mutations in COL17A1 in the treatment of junctional epidermolysis bullosa (JEB)., Methods: In this study, we treated primary type XVII collagen (C17)-deficient JEB keratinocytes with either Cas9 nuclease or nickase (Cas9n) ribonucleoproteins (RNP) and a single-stranded oligonucleotide (ssODN) HDR template in order to correct a causal pathogenic frameshift mutation within the COL17A1 gene., Results: As analyzed by next-generation sequencing of RNP-nucleofected keratinocytes, we observed an HDR efficiency of ∼38% when cells were treated with the high-fidelity Cas9 nuclease, a mutation-specific sgRNA, and an ssODN template. The combined induction of end-joining repair and HDR-mediated pathways resulted in a C17 restoration efficiency of up to 60% as assessed by flow cytometry. Furthermore, corrected JEB keratinocytes showed a significantly increased adhesive strength to laminin-332 and an accurate deposition of C17 along the basement membrane zone (BMZ) upon differentiation into skin equivalents., Conclusion: Here we present a gene editing approach capable of reducing end joining-generated repair products while increasing the level of seamless HDR-mediated gene repair outcomes, thereby providing a promising CRISPR/Cas9-based gene editing approach for JEB., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Petković, Bischof, Kocher, March, Liemberger, Hainzl, Strunk, Raninger, Binder, Reichelt, Guttmann-Gruber, Wally, Piñón Hofbauer, Bauer and Koller.)

Background Mutations in the gene COL17A1 coding for type XVII collagen cause non-Herlitz junctional epidermolysis bullosa (nH-JEB). Objectives Here we give an overview of the genotype-phenotype correlation in 12 patients from the Netherlands with type XVII collagen-deficient nH-JEB. Patient and methods Family and personal history and clinical presentation were recorded from each patient, and skin biopsies of intact and bullous skin were taken for immunofluorescence and electron microscopy. The mutations were identified by analysing the patient's DNA isolated from peripheral blood cells. Results DNA analysis identified five novel deletions: 1284delA, 1365delC, 3236delT, 3600–3601delCT and 4425delT. Interestingly, we identified a new patient, homozygous for 4425delT, with an exceptionally mild blistering phenotype. All together, three patients had more localized blistering confined to hands, lower legs and face, absent or very mild nail dystrophy, normal primary hair and sparse secondary hair. Nine patients had generalized blistering, nail dystrophy, sparse primary and absent secondary hair. All 12 patients had amelogenesis imperfecta (enamel pitting). Immunofluorescence (IF) antigen mapping with monoclonal antibodies 1A8C and 1D1 that bind to type XVII collagen, but not to its 97-kDa fragment was completely negative in patients with generalized blistering, whereas reduced in patients with localized blistering. Conclusions Our data reveal that in patients with COL17A1 mutations a localized nH-JEB phenotype can be differentiated from a generalized nH-JEB phenotype by IF antigen mapping. The data are important for genetic counselling at early age when the clinical phenotype is not yet clear. [ABSTRACT FROM AUTHOR]

Generalized atrophic benign epidermolysis bullosa (GABEB), a subtype of epidermolysis bullosa (EB), is an autosomal recessive skin disease characterized by derm-epidermal separation leading to skin fragility and atrophy and other associated abnormalities. Although a few reports demonstrated that eosinophils are infiltrating beneath bullas in infants with some types of EB, no such condition in adult GABEB patients has been known. Here we report on three adult patients with GABEB from a Japanese family, whose bullous skin lesions showed massive eosinophil infiltration. One of the three patients showed amyloid deposition at the intestine, kidney, and skin. Linkage analysis revealed that GABEB in the family was linked to COL17A1 with a maximum LOD score of 3.08. Mutation analysis identified in the three patients a homozygous insertional mutation, 209-210insCA, in exon 5 of COL17A1. The expression of mutated COL17A1 was confirmed by semiquantitative RT-PCR, but no signals for truncated COL17A1 protein were detected by the immunohistochemical studies using antibodies against BP180. Furthermore, no autoantibody against the mutant protein was detected by western blot analysis. It is thus less likely that autoantibody and/or a local immune reaction in their skin has a primary role in eosinophil infiltration in these patients. [ABSTRACT FROM AUTHOR]

Mutations inCOL17A1, coding for type XVII collagen, cause junctional epidermolysis bullosa with an ultrastructural plane of cleavage through the lamina lucida of the epidermal basement membrane.To identify theCOL17A1mutations in a child with reduced type XVII collagen expression and intraepidermal blister formation.Protein expression and level of tissue separation were studied by immunofluorescence and electron microscopy. The mutations were identified by analysing the patient's DNA and mRNA.Immunofluorescence microscopy performed on nonlesional skin demonstrated absence of the type XVII collagen endodomain and presence, although reduced, of the shed ectodomain. Electron microscopy showed that the plane of cleavage was through the basal cells, not through the lamina lucida. Two heterozygous mutations were identified inCOL17A1: a new 3′-acceptor splice-site mutation in intron 21 (1877–2A→C), and a deletion in exon 48 (3432delT). The splice-site mutation in intron 21 results in alternative transcripts of which two are in-frame, with deletions of the first nine codons of exon 22 and the entire exon 22, respectively. By Western blot analysis, a type XVII collagen molecule was detected that was slightly smaller than normal.Occasionally mutations in theCOL17A1gene may result in split levels suggesting epidermolysis bullosa simplex rather than junctional epidermolysis bullosa. [ABSTRACT FROM AUTHOR]

Pasmooij AMG, van Zalen S, Nijenhuis AM, Kloosterhuis AJ, Zuiderveen J, Jonkman MF, Pas HH. A very mild form of non-Herlitz junctional epidermolysis bullosa: BP180 rescue by outsplicing of mutated exon 30 coding for the COL15 domain. Mutations in the gene COL17A1 cause non-Herlitz junctional epidermolysis bullosa. Here, we describe a patient who, despite two heterozygous mutations in COL17A1, has an extremely mild form of the disease missing most of the characteristic clinical features. DNA analysis revealed a frame-shift mutation 3432delT and a nonsense mutation 2356C→T (Q751X). cDNA analysis showed that the deleterious effect of the latter mutation was skirted by deleting the premature termination codon containing exon 30. In this way, the reading frame was restored, resulting in a 36 nucleotides shorter mRNA transcript. Immunoblot analysis showed expression of the 180-kDa bullous pemphigoid antigen (BP180) with a slightly higher SDS-PAGE mobility, in line with the deletion of 12 amino acids from the COL15 domain. Immunofluorescence of skin sections showed diminished, but correctly localised expression of BP180, and this, in concert with the mild clinical phenotype, suggests that this COL15 mutated BP180 is still partly functional. [ABSTRACT FROM AUTHOR]

SummaryIn this study we describe six Italian patients presenting an unusually mild variant of non-Herlitz junctional epidermolysis bullosa associated with a reduced expression of type XVII collagen. All patients are homozygous for a novel nonsense mutation (R795X) within exon 33 of COL17A1 and show a common haplotype, attesting propagation of an ancestral allele within the Italian population. Analysis of patients' COL17A1 transcripts showed the presence of two mRNA species: a normal-sized mRNA carrying mutation R795X that undergoes rapid decay, and a transcript generated by in-frame skipping of exon 33. Patients keratinocytes were shown to synthesize minute amounts of type XVII collagen, which appeared correctly localized along the cutaneous basement membrane. We therefore suggest that the exon 33-deleted COL17A1 splice variant encodes for type XVII collagen molecules that maintain a functional role and account for the mild phenotype of our patients. [ABSTRACT FROM AUTHOR]

Cell competition (CC) is a feature that allows tumor cells to outcompete and eliminate adjacent cells that are deemed less fit. Studies of CC, first described in Drosophila melanogaster, reveal a diversity of underlying mechanisms. In this review, we will discuss three recent studies that expand our understanding of the molecular features governing CC. In particular, we will focus on a molecular fitness fingerprint, oncogenic pathways, and the importance of cell junction stability. A fitness fingerprint, mediated by flower (hFWE) protein isoforms, dictates that cells expressing the flower-win isoforms will outcompete adjacent flower-loss-expressing cells. The impact of the flower protein isoforms is seen in cancer progression and may have diagnostic potential. The yes-associated protein (YAP) and TAZ transcription factors, central mediators of the oncogenic Hippo pathway, elevate peritumoral fitness thereby protecting against tumor progression and provide a suppressive barrier. Similarly, COL17A1 is a key component in hemidesmosome stability, and its expression in epidermal stem cells contributes to fitness competition and aging characteristics. The contributions of these pathways to disease development and progression will help define how CC is hijacked to favor cancer growth. Understanding these features will also help frame the diagnostic and therapeutic possibilities that may place CC in the crosshairs of cancer therapeutics. [ABSTRACT FROM AUTHOR]

At the early stage of cancer development, oncogenic mutations often cause multilayered epithelial structures. However, the underlying molecular mechanism still remains enigmatic. By performing a series of screenings targeting plasma membrane proteins, we have found that collagen XVII (COL17A1) and CD44 accumulate in RasV12-, Src-, or ErbB2-transformed epithelial cells. In addition, the expression of COL17A1 and CD44 is also regulated by cell density and upon apical cell extrusion. We further demonstrate that the expression of COL17A1 and CD44 is profoundly upregulated at the upper layers of multilayered, transformed epithelia in vitro and in vivo. The accumulated COL17A1 and CD44 suppress mitochondrial membrane potential and reactive oxygen species (ROS) production. The diminished intracellular ROS level then promotes resistance against ferroptosis-mediated cell death upon cell extrusion, thereby positively regulating the formation of multilayered structures. To further understand the functional role of COL17A1, we performed comprehensive metabolome analysis and compared intracellular metabolites between RasV12 and COL17A1-knockout RasV12 cells. The data imply that COL17A1 regulates the metabolic pathway from the GABA shunt to mitochondrial complex I through succinate, thereby suppressing the ROS production. Moreover, we demonstrate that CD44 regulates membrane accumulation of COL17A1 in multilayered structures. These results suggest that CD44 and COL17A1 are crucial regulators for the clonal expansion of transformed cells within multilayered epithelia, thus being potential targets for early diagnosis and preventive treatment for precancerous lesions., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Genetic and environmental factors influence wrinkle development. We evaluated the polygenetic risk score (PRS) by pooling the selected single nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS) for wrinkles and the interaction of PRS with lifestyle factors in middle-aged women. Under the supervision of a dermatologist, the skin status of 128 women aged over 40 years old was evaluated with Mark-Vu, a skin diagnosis system. PRS was generated from the selected SNPs for wrinkle risk from the genome-wide association study. Lifestyle interactions with PRS were also evaluated for wrinkle risk. Participants in the wrinkled group were more likely to be post-menopausal, eat less fruit, take fewer vitamin supplements, exercise less, and be more tired after awakening in the morning than those in the less-wrinkled group. The PRS included EGFR _rs1861003, MMP16 _rs6469206, and COL17A1 _rs805698. Subjects with high PRS had a wrinkle risk 15.39-fold higher than those with low PRS after adjusting for covariates, and they had a 10.64-fold higher risk of a large skin pore size. Menopause, UV exposure, and water intake interacted with PRS for wrinkle risk: the participants with high PRS had a much higher incidence of wrinkle risk than those with low PRS, only among post-menopausal women and those with UV exposure. Only with low water intake did the participants with medium PRS have increased wrinkle risk. In conclusion, women aged >40 years with high PRS-related collagen metabolism may possibly avoid wrinkle risk by avoiding UV exposure by applying sunscreen, maintaining sufficient water intake, and managing estrogen deficiency.