SPINK5 and Netherton syndrome: novel mutations, demonstration of missing LEKTI, and differential expression of transglutaminases.
Netherton syndrome (NTS) is an autosomal recessive congenital ichthyosis featuring chronic inflammation of the skin, hair anomalies, epidermal hyperplasia with an impaired epidermal barrier function, failure to thrive and atopic manifestations. The disease is caused by mutations in the SPINK5 gene encoding the serine proteinase inhibitor lympho-epithelial Kazal-type inhibitor (LEKTI). Sequence analyses of SPINK5 in seven NTS patients from five different families allowed us to identify two known and three novel mutations all creating premature termination codons. We developed a monoclonal antibody giving a strong signal for LEKTI in the stratum granulosum of normal skin and demonstrated absence of the protein in NTS epidermis. Immunoblot analysis revealed presence of full length LEKTI and of LEKTI cleavage fragments in normal hair roots, whereas in NTS hair roots LEKTI and its cleavage products were completely missing. Transglutaminase1 activity was present throughout almost the entire suprabasal epidermis in NTS, whereas in normal skin it is restricted to the stratum granulosum. In contrast, immunostaining for transglutaminase3 was absent or faint. Moreover, comparable with the altered pattern in psoriatic skin the epidermis in NTS strongly expressed the serine proteinase inhibitor SKALP/elafin and the anti-microbial protein human beta-defensin 2. These studies demonstrate LEKTI deficiency in the epidermis and in hair roots at the protein level and an aberrant expression of other proteins, especially transglutaminase1 and 3, which may account for the impaired epidermal barrier in NTS.
Raghunath
Michael
M
Department of Dermatology, University Hospital, University of Münster, Von-Esmarch-Strasse 58, D-48149 Münster, Germany.
Tontsidou
Lambrini
L
Oji
Vinzenz
V
Aufenvenne
Karin
K
Schürmeyer-Horst
Funda
F
Jayakumar
Arumugam
A
Ständer
Hartmut
H
Smolle
Josef
J
Clayman
Gary L
GL
Traupe
Heiko
H
D000328:Adult; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D015415:Biomarkers; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000276:immunology; D002454:Cell Differentiation; D018389:Codon, Nonsense; D004817:Epidermis / Q000201:enzymology / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D016113:Ichthyosiform Erythroderma, Congenital / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D053491:Proteinase Inhibitory Proteins, Secretory; D000074163:Serine Peptidase Inhibitor Kazal-Type 5; D013577:Syndrome; D011503:Transglutaminases / Q000235:genetics* / Q000378:metabolism
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D018389:Codon, Nonsense; D053491:Proteinase Inhibitory Proteins, Secretory; C120650:SPINK5 protein, human; D000074163:Serine Peptidase Inhibitor Kazal-Type 5; C498712:TGM3 protein, human; D011503:Transglutaminases; C105804:transglutaminase 1