scholarly journals Laminin 332 in junctional epidermolysis bullosa

2013 ◽  
Vol 7 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Dimitra Kiritsi ◽  
Cristina Has ◽  
Leena Bruckner-Tuderman
Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 716
Author(s):  
Daniele Castiglia ◽  
Paola Fortugno ◽  
Angelo Giuseppe Condorelli ◽  
Sabina Barresi ◽  
Naomi De Luca ◽  
...  

Junctional epidermolysis bullosa (JEB) is a clinically and genetically heterogeneous skin fragility disorder frequently caused by mutations in genes encoding the epithelial laminin isoform, laminin-332. JEB patients also present mucosal involvement, including painful corneal lesions. Recurrent corneal abrasions may lead to corneal opacities and visual impairment. Current treatments are merely supportive. We report a novel JEB phenotype distinguished by the complete resolution of skin fragility in infancy and persistent ocular involvement with unremitting and painful corneal abrasions. Biallelic LAMB3 mutations c.3052-5C>G and c.3492_3493delCG were identified as the molecular basis for this phenotype, with one mutation being a hypomorphic splice variant that allows residual wild-type laminin-332 production. The reduced laminin-332 level was associated with impaired keratinocyte adhesion. Then, we also investigated the therapeutic power of a human amniotic membrane (AM) eyedrop preparation for corneal lesions. AM were isolated from placenta donors, according to a procedure preserving the AM biological characteristics as a tissue, and confirmed to contain laminin-332. We found that AM eyedrop preparation could restore keratinocyte adhesion in an in vitro assay. Of note, AM eyedrop administration to the patient resulted in long-lasting remission of her ocular manifestations. Our findings suggest that AM eyedrops could represent an effective, non-invasive, simple-to-handle treatment for corneal lesions in patients with JEB and possibly other EB forms.


2018 ◽  
Vol 115 (28) ◽  
pp. E6536-E6545 ◽  
Author(s):  
Vadim Lincoln ◽  
Jon Cogan ◽  
Yingping Hou ◽  
Michaela Hirsch ◽  
Michelle Hao ◽  
...  

Herlitz junctional epidermolysis bullosa (H-JEB) is an incurable, devastating, and mostly fatal inherited skin disease for which there is only supportive care. H-JEB is caused by loss-of-function mutations in LAMA3, LAMB3, or LAMC2, leading to complete loss of laminin 332, the major component of anchoring filaments, which mediate epidermal-dermal adherence. LAMB3 (laminin β3) mutations account for 80% of patients with H-JEB, and ∼95% of H-JEB–associated LAMB3 mutations are nonsense mutations leading to premature termination codons (PTCs). In this study, we evaluated the ability of gentamicin to induce PTC readthrough in H-JEB laminin β3-null keratinocytes transfected with expression vectors encoding eight different LAMB3 nonsense mutations. We found that gentamicin induced PTC readthrough in all eight nonsense mutations tested. We next used lentiviral vectors to generate stably transduced H-JEB cells with the R635X and C290X nonsense mutations. Incubation of these cell lines with various concentrations of gentamicin resulted in the synthesis and secretion of full-length laminin β3 in a dose-dependent and sustained manner. Importantly, the gentamicin-induced laminin β3 led to the restoration of laminin 332 assembly, secretion, and deposition within the dermal/epidermal junction, as well as proper polarization of α6β4 integrin in basal keratinocytes, as assessed by immunoblot analysis, immunofluorescent microscopy, and an in vitro 3D skin equivalent model. Finally, newly restored laminin 332 corrected the abnormal cellular phenotype of H-JEB cells by reversing abnormal cell morphology, poor growth potential, poor cell-substratum adhesion, and hypermotility. Therefore, gentamicin may offer a therapy for H-JEB and other inherited skin diseases caused by PTC mutations.


2020 ◽  
Vol 21 (4) ◽  
pp. 1426
Author(s):  
Paola Fortugno ◽  
Angelo Giuseppe Condorelli ◽  
Elena Dellambra ◽  
Liliana Guerra ◽  
Francesca Cianfarani ◽  
...  

Variably reduced expression of the basement membrane component laminin-332 (α3aβ3γ2) causes junctional epidermolysis bullosa generalized intermediate (JEB-GI), a skin fragility disorder with an increased susceptibility to squamous cell carcinoma (SCC) development in adulthood. Laminin-332 is highly expressed in several types of epithelial tumors and is central to signaling pathways that promote SCC tumorigenesis. However, laminin-332 mutations and expression in individuals affected by JEB-GI and suffering from recurrent SCCs have been poorly characterized. We studied a JEB-GI patient who developed over a hundred primary cutaneous SCCs. Molecular analysis combined with gene expression studies in patient skin and primary keratinocytes revealed that the patient is a functional hemizygous for the p.Cys1171* mutant allele which is transcribed in a stable mRNA encoding for a β3 chain shortened of the last two C-terminal amino acids (Cys1171-Lys1172). The lack of the Cys1171 residue involved in the C-terminal disulphide bond to γ2 chain did not prevent assembly, secretion, and proteolytic processing of the heterotrimeric molecule. Immunohistochemistry of SCC specimens revealed accumulation of mutant laminin-332 at the epithelial-stromal interface of invasive front. We conclude that the C-terminal disulphide bond is a structural element crucial for laminin-332 adhesion function in-vivo. By saving laminin-332 amount, processing, and signaling role the p.Cys1171* mutation may allow intrinsic pro-tumorigenic properties of the protein to be conveyed, thus contributing to invasiveness and recurrence of SCCs in this patient.


Cell Reports ◽  
2019 ◽  
Vol 27 (7) ◽  
pp. 2036-2049.e6 ◽  
Author(s):  
Laura De Rosa ◽  
Alessia Secone Seconetti ◽  
Giorgio De Santis ◽  
Giovanni Pellacani ◽  
Tobias Hirsch ◽  
...  

2020 ◽  
Vol 28 (5) ◽  
pp. 1327-1338 ◽  
Author(s):  
Andrew Kwong ◽  
Jon Cogan ◽  
Yingping Hou ◽  
Richard Antaya ◽  
Michelle Hao ◽  
...  

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