Detection of revertant mosaicism in epidermolysis bullosa through Cas9-targeted long read sequencing
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ABSTRACT:
ORGANISM(S): Escherichia coli Homo sapiens
PROVIDER: GSE186002 | GEO | 2022/01/13
REPOSITORIES: GEO
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Project description:Detection of revertant mosaicism in epidermolysis bullosa through Cas9-targeted long read sequencing
| PRJNA771681 | ENA
Project description:Revertant mosaicism by somatic reversion of inherited mutations has been described for a number of genetic diseases. Several mechanisms can underlie this reversion process, such as gene conversion, crossing-over, true back mutation, and second-site mutation. Here, we report the occurrence of multiple corrections in two unrelated probands with revertant mosaicism of non-Herlitz junctional epidermolysis bullosa, an autosomal recessive genodermatosis due to mutations in the COL17A1 gene. Immunofluorescence microscopy and laser dissection microscopy, followed by DNA and RNA analysis, were performed on skin biopsy specimens. In patient 1, a true back mutation, 3781T-->C, was identified in the specimen from the arm, and a second-site mutation, 4463-1G-->A, which compensated for the frameshift caused by the inherited 4424-5insC mutation, was identified in the 3' splice site of exon 55 in a specimen from the middle finger. Patient 2 showed--besides two distinct gene conversion events in specimens from the arm and hand sites, both of which corrected the 1706delA mutation--a second-site mutation (3782G-->C) in an ankle specimen, which prevented the premature ending of the protein by the 3781C-->T nonsense mutation (R1226X). Thus, both inherited mutations, paternal as well as maternal, reverted at least once by different reversion events in distinct cell clusters in the described patients. The occurrence of multiple correcting mutations within the same patient indicates that in vivo reversion is less unusual than was generally thought. Furthermore, in the male patient, mosaic patterns of type XVII collagen-positive keratinocytes were present in clinically unaffected and affected skin. This latter observation makes it likely that reversion may be overlooked and may happen more often than expected.
| S-EPMC1271383 | biostudies-literature
Project description:Revertant mosaicism, or "natural gene therapy", is the phenomenon in which germline mutations are corrected by somatic events. In recent years, revertant mosaicism has been identified in all major types of epidermolysis bullosa, the group of heritable blistering disorders caused by mutations in the genes encoding epidermal adhesion proteins. Moreover, revertant mosaicism appears to be present in all patients with a specific subtype of recessive epidermolysis bullosa. We therefore hypothesized that revertant mosaicism should be expected at least in all patients with recessive forms of epidermolysis bullosa. Naturally corrected, patient-own cells are of extreme interest for their promising therapeutic potential, and their presence in all patients would open exciting, new treatment perspectives to those patients. To test our hypothesis, we determined the probability that single nucleotide reversions occur in patients' skin using a mathematical developmental model. According to our model, reverse mutations are expected to occur frequently (estimated 216x) in each patient's skin. Reverse mutations should, however, occur early in embryogenesis to be able to drive the emergence of recognizable revertant patches, which is expected to occur in only one per ~10,000 patients. This underestimate, compared to our clinical observations, can be explained by the "late-but-fitter revertant cell" hypothesis: reverse mutations arise at later stages of development, but provide revertant cells with a selective growth advantage in vivo that drives the development of recognizable healthy skin patches. Our results can be extrapolated to any other organ with stem cell division numbers comparable to skin, which may offer novel future therapeutic options for other genetic conditions if these revertant cells can be identified and isolated.
| S-EPMC5823395 | biostudies-literature
Project description:Revertant mosaicism due to in vivo reversion of an inherited mutation has been described in the genetic skin disease epidermolysis bullosa (EB) for the genes KRT14 and COL17A1. Here we demonstrate the presence of multiple second-site mutations, all correcting the germline mutation LAMB3:c.628G-->A;p.E210K, in 2 unrelated non-Herlitz junctional EB patients with revertant mosaicism. Both probands had a severe reduction in laminin-332 expression in their affected skin. Remarkably, the skin on the lower leg of patient 078-01 (c.628G-->A/c.1903C-->T) became progressively clinically healthy, with normal expression of laminin-332 on previously affected skin. In the other proband, 029-01 (c.628G-->A/c.628G-->A), the revertant patches were located at his arms, shoulder, and chest. DNA analysis showed different second-site mutations in revertant keratinocytes of distinct biopsy specimens (c.565-3T-->C, c.596G-->C;p.G199A, c.619A-->C;p.K207Q, c.628+42G-->A, and c.629-1G-->A), implying that there is not a single preferred mechanism for the correction of a specific mutation. Our data offer prospects for EB treatment in particular cases, since revertant mosaicism seems to occur at a higher frequency than expected. This opens the possibility of applying revertant cell therapy in mosaic EB of the LAMB3 gene by using autologous naturally corrected keratinocytes, thereby bypassing the recombinant gene correction phase.
| S-EPMC1857245 | biostudies-literature
Project description:BackgroundRevertant mosaicism has been described previously in recessive dystrophic epidermolysis bullosa (RDEB), manifesting as regions of skin with normal mechanical and biological characteristics. Here we report the discovery of revertant dermal fibroblasts, unique in that all other documented cases of revertant mosaicism occur in epidermal keratinocytes.ObjectivesTo determine the cause of revertant mosaicism found in a patient with RDEB from isolated epidermal keratinocytes and dermal fibroblasts in blister and mosaic skin regions.MethodsSkin biopsies were taken from blister and mosaic skin regions of a patient with RDEB. Allele identification was confirmed and the type VII collagen (C7) content and COL7A1 expression profile of isolated keratinocytes and fibroblasts was determined.ResultsKeratinocytes isolated from the mosaic area had a slight increase in C7, although overall expression of COL7A1 was unchanged between blister and mosaic fibroblasts. Differential allele expression was identified in blister and mosaic fibroblasts using targeted RNA sequencing (TREx), where the allele harbouring a point mutation was preferentially expressed over that containing a frameshift mutation. A crossing over event was identified in mosaic fibroblasts that was not present in blister fibroblasts, yielding a functional COL7A1 allele in a subset of cells.ConclusionsIn documenting a novel case of revertant mosaicism in RDEB, we have identified dermal fibroblasts as having the capacity to correct blistering functionally. We have also pioneered the use of TREx in quantifying allele-specific expression. Using fibroblasts instead of keratinocytes for RDEB therapies offers advantages in the local and systemic therapy of RDEB. What's already known about this topic? Revertant mosaicism has been previously documented in patients with recessive dystrophic epidermolysis bullosa (RDEB), however, it has only been found in epidermal keratinocytes. What does this study add? We have demonstrated that COL7A1 gene reversion in dermal fibroblasts occurs and is able to form functional skin in a patient with RDEB. Additionally, we have pioneered a new application for targeted RNA sequencing in quantifying allele-specific expression in fibroblasts and keratinocytes. What is the translational message? This opens up possibilities for using fibroblasts as local and systemic therapy for patients with RDEB.
| S-EPMC6766431 | biostudies-literature
Project description:We performed clinical trial of treatment with cultured epidermal autograft (CEA) produced from patients’ own revertant epidermal keratinocytes as a proof-of-concept study. We successfully produced CEAs from genetically confirmed revertant skin of the three EI patients and genetically confirmed that CEAs mainly consist of revertant wild-type cells by amplicon sequencing and droplet digital PCR analysis. Single-cell RNA sequencing analysis confirmed normal proliferation and safety profiling of CEAs.
2024-05-22 | GSE245859 | GEO
Project description:The goal of this study is to characterize the expression profile of Epidermolysis bullosa simplex-mottled pigmentation (EBS-MP) patient compared with normal subjects using genomic expression analyses. Microarray analyses were performed with RNA isolated from skin biopsies. Robust multiarray analysis (RMA) normalization and Smyth’s moderated t test were used to select differentially expressed genes. Expression profiling comparisons show that 52 genes are differentially expressed in EBS-MP patients compared to control subjects. Difference of expression for three genes (TYR, CCL22 , and ACVR1C ) was validated using real-time reverse transcription–polymerase chain reaction. Twelve genes were related to lipid biosynthesis process, two to keratinisation and skin pigmentation, Nineteen to cell growth and apoptosis, five to immune response and fourteen to predicted or less known function cluster. To our knowledge, the distinctive pattern of gene expression that characterizes EBS-MP versus healthy skin tissue has never been reported. RNA used for the microarrays analysis was isolated from superficial 2mm punch biopsies composed of mainly epidermis with minimal dermis amounts of normal-appearing skin of one EBS-MP patient and seven healthy volunteers.
2012-03-10 | E-GEOD-36406 | biostudies-arrayexpress
Project description:Seven sets of SILAC-based AP-MS experiments were performed analyzing phosphotyrosine signaling after 0, 5, and 10 min of PDGF-BB treatment of primary human skin fibroblasts. For this, proteins phosphorylated on tyrosine residues were enriched using the 4G10 antibody.
2021-11-01 | PXD022985 | Pride
Project description:The goal of this study is to characterize the expression profile of Epidermolysis bullosa simplex-mottled pigmentation (EBS-MP) patient compared with normal subjects using genomic expression analyses. Microarray analyses were performed with RNA isolated from skin biopsies. Robust multiarray analysis (RMA) normalization and Smyth’s moderated t test were used to select differentially expressed genes. Expression profiling comparisons show that 52 genes are differentially expressed in EBS-MP patients compared to control subjects. Difference of expression for three genes (TYR, CCL22 , and ACVR1C ) was validated using real-time reverse transcription–polymerase chain reaction. Twelve genes were related to lipid biosynthesis process, two to keratinisation and skin pigmentation, Nineteen to cell growth and apoptosis, five to immune response and fourteen to predicted or less known function cluster. To our knowledge, the distinctive pattern of gene expression that characterizes EBS-MP versus healthy skin tissue has never been reported.
2012-03-10 | GSE36406 | GEO
Project description:Patients with the genetic skin blistering disease recessive dystrophic epidermolysis bullosa (RDEB) develop aggressive cutaneous squamous cell carcinoma (cSCC). Metastasis leading to mortality is greater in RDEB than in other patient groups with cSCC. Here we investigate the dermal component in RDEB using mRNA expression profiling to compare cultured fibroblasts isolated from individuals without cSCC and directly from tumor matrix in RDEB and non-RDEB samples. While gene expression of RDEB normal skin fibroblasts resembled that of cancer-associated fibroblasts, RDEB cancer-associated fibroblasts exhibited a distinct and divergent gene expression profile, with a large proportion of the differentially expressed genes involved in matrix and cell adhesion. RDEB cancer-associated fibroblasts conferred increased adhesion and invasion to tumor and non-tumor keratinocytes. Reduction of COL7A1, the defective gene in RDEB, in normal dermal fibroblasts led to increased type XII collagen, thrombospondin-1 and Wnt-5A, while re-expression of wild type COL7A1 in RDEB fibroblasts decreased type XII collagen, thrombospondin- 1, and Wnt-5A expression, reduced tumor cell invasion in organotypic culture, and restricted tumor growth in vivo. Overall our findings demonstrate that matrix composition in patients with RDEB is a permissive environment for tumor development, and type VII collagen directly regulates the composition of matrix proteins secreted by dermal and cancer-associated fibroblasts. 16 samples
2012-05-15 | E-GEOD-37738 | biostudies-arrayexpress