Inherited Keratinization Disorders

Disorders of keratinization include a variety of diseases characterized by abnormal epidermal differentiation and desquamation. Abnormalities in desquamation and differentiation usually result from abnormal corneocyte shedding or from increased epidermal cell proliferation. Ichthyoses are divided into two groups as syndromic and non-syndromic. This review describes ichthyoses, which are commonly seen among hereditary disorders of keratinization. (Turkderm 2011; 45 Suppl 2: 73-80)WoSScopu

Inherited Bullous Diseases

Epidermolysis bullosa (EB), refers to a group of inherited bullous disorders, characterized by fagility of the skin and mucous membranes, and blister formation in response to minor friction or trauma. Skin fragility and bulla formation of EB result from genetic mutations of any of dozen genes that encode structural proteins which normally reside within the epidermis, the dermo-epidermal juntion, or the upper dermis. There are four major type of inherited epidermolysis bullosa: EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and Kindler syndrome. (Turkderm 2011; 45 Suppl 2: 81-6)WoSScopu

Photochemotherapy for Photodermatoses

Nowadays, photo(chemo)therapy procedures mainly ultraviolet-B and PUVA have been used in the treatment of various photodermatoses. The most commonly used fotodermatoses can be classified as polymorphic light eruption, solar urticaria, chronic actinic dermatitis, hydroa vacciniforme and actinic prurigo. In this review, the use of photo(chemo)therapy in above aforementioned photodermatoses will be discussed and treatment protocols will be emphasized.Wo

Impairment Of Lipophagy By Pnpla1 Mutations Causes Lipid Droplet Accumulation In Primary Fibroblasts Of Autosomal Recessive Congenital Ichthyosis Patients

Background: Autosomal Recessive Congenital Ichthyosis (ARCI) is a group of epidermal keratinization disorders. One of the disease-associated proteins, patatin-like phospholipase domain-containing protein-1 (PNPLA1), plays a key role in the epidermal omega-O-acylceramide synthesis and localizes on the surface of lipid droplets (LDs). Objective: Previously, routine clinical test results showed abnormal LD accumulation in blood smear samples of our ARCI patients with PNPLA1 mutations. To investigate the abnormal accumulation of LDs, we analyzed primary fibroblast cells of ARCI patients with PNPLA1 mutations (p.Y245del and p.D172N). We hypothesized that PNPLA1 mutations might affect lipophagy-mediated regulation of LDs and cause intracellular lipid accumulation in ARCI patients. Methods: LD accumulation was analyzed by fluorescence staining with BODIPY (R) 493/503 in the fibroblasts of patient cells and PNPLA1 siRNA transfected control fibroblast cells. The expression of PNPLA1 and its effects on the lipophagy-mediated degradation of LDs were analyzed by immunocytochemistry and immunoblotting. Results: Our results showed that mutant or downregulated PNPLA1 protein causes abnormal intracellular LD accumulation. We found that PNPLA1 mutations affect neither the cellular localization nor the expression levels of the protein in fibroblast cells. When we analyzed lipophagic degradation process, LC3 expression and the number of autophagosomes were significantly decreased in fibroblast cells of the patients. In addition, co-localization of LDs with autophagosomes and lysosomes were markedly less than that of the control group. Conclusion: PNPLA1 mutations caused disturbances in both autophagosome formation and fusion of autophagosomes with lysosomes. Our results indicate a possible role for PNPLA1 protein in LD regulation via lipophagy-mediated degradation. (C) 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.WoSScopu

Impairment of lipophagy by PNPLA1 mutations causes lipid droplet accumulation in primary fibroblasts of autosomal recessive congenital ichthyosis patients

Background: Autosomal Recessive Congenital Ichthyosis (ARCI) is a group of epidermal keratinization disorders. One of the disease-associated proteins, patatin-like phospholipase domain-containing protein-1 (PNPLA1), plays a key role in the epidermal omega-O-acylceramide synthesis and localizes on the surface of lipid droplets (LDs). Objective: Previously, routine clinical test results showed abnormal LD accumulation in blood smear samples of our ARCI patients with PNPLA1 mutations. To investigate the abnormal accumulation of LDs, we analyzed primary fibroblast cells of ARCI patients with PNPLA1 mutations (p.Y245del and p.D172N). We hypothesized that PNPLA1 mutations might affect lipophagy-mediated regulation of LDs and cause intracellular lipid accumulation in ARCI patients. Methods: LD accumulation was analyzed by fluorescence staining with BODIPY1493/503 in the fibroblasts of patient cells and PNPLA1 siRNA transfected control fibroblast cells. The expression of PNPLA1 and its effects on the lipophagy-mediated degradation of LDs were analyzed by immunocytochemistry and immunoblotting. Results: Our results showed that mutant or downregulated PNPLA1 protein causes abnormal intracellular LD accumulation. We found that PNPLA1 mutations affect neither the cellular localization nor the expression levels of the protein in fibroblast cells. When we analyzed lipophagic degradation process, LC3 expression and the number of autophagosomes were significantly decreased in fibroblast cells of the patients. In addition, co-localization of LDs with autophagosomes and lysosomes were markedly less than that of the control group. Conclusion: PNPLA1 mutations caused disturbances in both autophagosome formation and fusion of autophagosomes with lysosomes. Our results indicate a possible role for PNPLA1 protein in LD regulation via lipophagy-mediated degradation

Identification Of Two Novel Pnpla1 Mutations In Turkish Families With Autosomal Recessive Congenital Ichthyosis

Autosomal recessive congenital ichthyosis (ARCI) is a group of inherited keratinization disorders that are characterized by abnormal epidermal keratinization. ARCI patients generally represent serious symptoms including collodion baby phenotype accompanied by dehydration, heat loss, electrolytic imbalance, and sepsis. ARCI shows high degree of clinical and genetic heterogeneity. To date, nine genes were shown to be responsible for ARCI phenotype. One of these genes, patatin-like phospholipase domain containing protein-1 (PNPLA1) was suggested to be involved in the synthesis of omega-O-acylceramides related to epidermal cornified lipid envelope organization. In addition to previously reported PNPLA1 mutations, we report two novel PNPLA1 mutations including one novel missense mutation c.335C > A (p.Ser112Tyr) and one novel deletion mutation c. 733_735delTAC (p.Tyr245del) in Turkish ARCI patients from unrelated consanguineous families. We also report previously reported missense mutation c.514G > A (p.Asp172Asn) in Turkish ARCI patients. Novel PNPLA1 mutations were shown to be located in the catalytic pat at in domain of PNPLA1 gene. Identification of novel mutations in PNPLA1 gene expands the mutational spectrum in the causative gene. Increase in the total number of cases has high diagnostic value in terms of genotype-phenotype correlation in ARCI patients.WoSScopu

Novel Mutations In Alox12B In Patients With Autosomal Recessive Congenital Ichthyosis And Evidence For Genetic Heterogeneity On Chromosome 17P13

We report clinical and molecular findings in 20 patients from 11 families with autosomal recessive congenital ichthyosis (ARCI) linked to chromosome 17p13, and attributed to mutations in the ALOX gene cluster, which includes three lipoxygenase genes, ALOXE3, ALOX12B, and ALOX15B. We identified six novel missense mutations and one novel deletion leading to a premature stop codon in ALOX12B in only six out of the 11 familes which led us to investigate a possible implication of ALOX15B. Mutation analysis of this gene, as well as ALOXE3, which is known to be mutated in some cases of ARCI, failed to reveal causative mutations in the five remaining ARCI families, indicating that other genes on chromosome 17p13 may be involved in this disease. However, by adding new variants to the repertoire of ALOX12B mutations in non-bullous congenital ichthyosiform erythroderma, our data contribute to an enlargement of the spectrum of mutations for the development of efficient molecular genetic tests for analysis of at risk individuals whose carrier status is unknown.WoSScopu