@article {554, title = {Fibroblast activation and abnormal extracellular matrix remodelling as common hallmarks in three cancer-prone genodermatoses.}, journal = {Br J Dermatol}, volume = {181}, year = {2019}, month = {2019 09}, pages = {512-522}, abstract = {

BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB), Kindler syndrome (KS) and xeroderma pigmentosum complementation group C (XPC) are three cancer-prone genodermatoses whose causal genetic mutations cannot fully explain, on their own, the array of associated phenotypic manifestations. Recent evidence highlights the role of the stromal microenvironment in the pathology of these disorders.

OBJECTIVES: To investigate, by means of comparative gene expression analysis, the role played by dermal fibroblasts in the pathogenesis of RDEB, KS and XPC.

METHODS: We conducted RNA-Seq analysis, which included a thorough examination of the differentially expressed genes, a functional enrichment analysis and a description of affected signalling circuits. Transcriptomic data were validated at the protein level in cell cultures, serum samples and skin biopsies.

RESULTS: Interdisease comparisons against control fibroblasts revealed a unifying signature of 186 differentially expressed genes and four signalling pathways in the three genodermatoses. Remarkably, some of the uncovered expression changes suggest a synthetic fibroblast phenotype characterized by the aberrant expression of extracellular matrix (ECM) proteins. Western blot and immunofluorescence in~situ analyses validated the RNA-Seq data. In addition, enzyme-linked immunosorbent assay revealed increased circulating levels of periostin in patients with RDEB.

CONCLUSIONS: Our results suggest that the different causal genetic defects converge into common changes in gene expression, possibly due to injury-sensitive events. These, in turn, trigger a cascade of reactions involving abnormal ECM deposition and underexpression of antioxidant enzymes. The elucidated expression signature provides new potential biomarkers and common therapeutic targets in RDEB, XPC and KS. What{\textquoteright}s already known about this topic? Recessive dystrophic epidermolysis bullosa (RDEB), Kindler syndrome (KS) and xeroderma pigmentosum complementation group C (XPC) are three genodermatoses with high predisposition to cancer development. Although their causal genetic mutations mainly affect epithelia, the dermal microenvironment likely contributes to the physiopathology of these disorders. What does this study add? We disclose a large overlapping transcription profile between XPC, KS and RDEB fibroblasts that points towards an activated phenotype with high matrix-synthetic capacity. This common signature seems to be independent of the primary causal deficiency, but reflects an underlying derangement of the extracellular matrix via transforming growth factor-β signalling activation and oxidative state imbalance. What is the translational message? This study broadens the current knowledge about the pathology of these diseases and highlights new targets and biomarkers for effective therapeutic intervention. It is suggested that high levels of circulating periostin could represent a potential biomarker in RDEB.

}, keywords = {Adolescent, Adult, Biopsy, Blister, Case-Control Studies, Cells, Cultured, Child, Child, Preschool, Epidermolysis Bullosa, Epidermolysis Bullosa Dystrophica, Extracellular Matrix, Extracellular Matrix Proteins, Female, Fibroblasts, Fibrosis, Gene Expression Regulation, Healthy Volunteers, Humans, Infant, Infant, Newborn, Male, Middle Aged, mutation, Periodontal Diseases, Photosensitivity Disorders, Primary Cell Culture, RNA-seq, Skin, Xeroderma Pigmentosum, Young Adult}, issn = {1365-2133}, doi = {10.1111/bjd.17698}, author = {Chac{\'o}n-Solano, E and Le{\'o}n, C and D{\'\i}az, F and Garc{\'\i}a-Garc{\'\i}a, F and Garc{\'\i}a, M and Esc{\'a}mez, M J and Guerrero-Aspizua, S and Conti, C J and Menc{\'\i}a, {\'A} and Mart{\'\i}nez-Santamar{\'\i}a, L and Llames, S and P{\'e}vida, M and Carbonell-Caballero, J and Puig-Butill{\'e}, J A and Maseda, R and Puig, S and de Lucas, R and Baselga, E and Larcher, F and Dopazo, J and Del Rio, M} } @article {484, title = {Two novel mutations in the BCKDK (branched-chain keto-acid dehydrogenase kinase) gene are responsible for a neurobehavioral deficit in two pediatric unrelated patients.}, journal = {Hum Mutat}, volume = {35}, year = {2014}, month = {2014 Apr}, pages = {470-7}, abstract = {

Inactivating mutations in the BCKDK gene, which codes for the kinase responsible for the negative regulation of the branched-chain α-keto acid dehydrogenase complex (BCKD), have recently been associated with a form of autism in three families. In this work, two novel exonic BCKDK mutations, c.520C>G/p.R174G and c.1166T>C/p.L389P, were identified at the homozygous state in two unrelated children with persistently reduced body fluid levels of branched-chain amino acids (BCAAs), developmental delay, microcephaly, and neurobehavioral abnormalities. Functional analysis of the mutations confirmed the missense character of the c.1166T>C change and showed a splicing defect r.[520c>g;521_543del]/p.R174Gfs1*, for c.520C>G due to the presence of a new donor splice site. Mutation p.L389P showed total loss of kinase activity. Moreover, patient-derived fibroblasts showed undetectable (p.R174Gfs1*) or barely detectable (p.L389P) levels of BCKDK protein and its phosphorylated substrate (phospho-E1α), resulting in increased BCKD activity and the very rapid BCAA catabolism manifested by the patients{\textquoteright} clinical phenotype. Based on these results, a protein-rich diet plus oral BCAA supplementation was implemented in the patient homozygous for p.R174Gfs1*. This treatment normalized plasma BCAA levels and improved growth, developmental and behavioral variables. Our results demonstrate that BCKDK mutations can result in neurobehavioral deficits in humans and support the rationale for dietary intervention.

}, keywords = {Amino Acids, Branched-Chain, Developmental Disabilities, Fibroblasts, Humans, Male, Mutation, Missense, Nervous System Diseases, Pediatrics, Protein Kinases}, issn = {1098-1004}, doi = {10.1002/humu.22513}, author = {Garc{\'\i}a-Cazorla, Angels and Oyarzabal, Alfonso and Fort, Joana and Robles, Concepci{\'o}n and Castej{\'o}n, Esperanza and Ruiz-Sala, Pedro and Bodoy, Susanna and Merinero, Bego{\~n}a and Lopez-Sala, Anna and Dopazo, Joaquin and Nunes, Virginia and Ugarte, Magdalena and Artuch, Rafael and Palac{\'\i}n, Manuel and Rodr{\'\i}guez-Pombo, Pilar and Alcaide, Patricia and Navarrete, Rosa and Sanz, Paloma and Font-Llitj{\'o}s, Mariona and Vilaseca, Ma Antonia and Ormaizabal, Aida and Pristoupilova, Anna and Agull{\'o}, Sergi Beltran} }