Hero Image

Publicaciones

Palisson F, Yubero MJ, Lecaros C, Krämer S, Fuentes C, Morandé P, Noya B, Cofré G, Castillo J, Acevedo F, Burattini N, Muñoz A, Klausseger A, Fuentes I. Epidemiology of Epidermolysis Bullosa in Chile. Br J Dermatol. 2024 Jun 11:ljae245. doi: 10.1093/bjd/ljae245.

Ver abstract

Dear Editor, Recent reports from high-income countries have emphasized the critical need for quality epidemiological
data on epidermolysis bullosa (EB) to strategically allocate healthcare resources and guide research efforts.1,2 Although
there are existing studies highlighting genetic variants of EB in various countries, in Latin America, an extensive epidemiological profile of Latin ethnic populations remains lacking.

This study aims to provide estimates of basic epidemiological measures and characterize pathogenic variants of EB in Chile. In Chile, there is only one EB referral centre, the DEBRA Chile Centre, which collects patient numbers and contains the national EB database. From January 2000 to December 2023, the DEBRA Chile Centre provided care to 292 patients with EB, representing 177 distinct families. Of these patients, 263 received both clinical and molecular diagnoses. Notably, 31 of these individuals were excluded from subsequent analysis, as they had acral peeling skin syndrome, a condition not categorized as EB in the latest classification.3 The remaining cohort considered for further analysis consisted of 232 patients from 157 unique families.

Susanne Krämer DDS, Anna Lena Hillebrecht, Yao Wang, Mihai Badea, Jose Ignacio Barrios, Sorina Danescu, Ignacia Fuentes PhD, Demet Kartal, Alfred Klausegger MSc, Enrique Ponce de León DDS, Reinhard Schilke, Ivelina Yordanova, Agnes Bloch-Zupan, Cristina Has MD. Expanding the orofacial anomalies in Kindler Epidermolysis bullosa: amelogenesis imperfecta as an additional feature. Accepted for publication in Jama Dermatology.

Ver abstract

Importance: Kindler epidermolysis bullosa is a genetic skin-blistering disease associated with recessive inherited pathogenic variants in FERMT1, which encodes kindlin-1. Severe orofacial manifestations of Kindler epidermolysis bullosa, including early oral squamous cell carcinoma, have been reported.

Objective: To determine whether hypoplastic pitted amelogenesis imperfecta is a feature of Kindler epidermolysis bullosa.

Design, settings, and participants: This longitudinal, 2-center cohort study was performed from 2003 to 2023 at the Epidermolysis Bullosa Centre, University of Freiburg, Germany, and the Special Care Dentistry Clinic, University of Chile in association with DEBRA Chile. Participants included a convenience sampling of all patients with a diagnosis of Kindler epidermolysis bullosa.

Main outcomes and measures: The primary outcomes were the presence of hypoplastic pitted amelogenesis imperfecta, intraoral wounds, gingivitis and periodontal disease, gingival hyperplasia, vestibular obliteration, cheilitis, angular cheilitis, chronic lip wounds, microstomia, and oral squamous cell carcinoma.

Results: The cohort consisted of 36 patients (15 female [42%] and 21 male [58%]; mean age at first examination, 23 years [range, 2 weeks to 70 years]) with Kindler epidermolysis bullosa. The follow-up ranged from 1 to 24 years. The enamel structure was assessed in 11 patients, all of whom presented with enamel structure abnormalities. The severity of hypoplastic pitted amelogenesis imperfecta varied from generalized to localized pitting. Additional orofacial features observed include gingivitis and periodontal disease, which was present in 90% (27 of 30 patients) of those assessed, followed by intraoral lesions (16 of 22 patients [73%]), angular cheilitis (24 of 33 patients [73%]), cheilitis (22 of 34 patients [65%]), gingival overgrowth (17 of 26 patients [65%]), microstomia (14 of 25 patients [56%]), and vestibular obliteration (8 of 16 patients [50%]). Other features included chronic lip ulcers (2 patients) and oral squamous cell carcinoma with lethal outcome (2 patients).

Conclusions and relevance: These findings suggest that hypoplastic pitted amelogenesis imperfecta is a feature of Kindler epidermolysis bullosa and underscore the extent and severity of oral manifestations in Kindler epidermolysis bullosa and the need for early and sustained dental care.

Tartaglia G., Fuentes I., Patel N., Varughese A., Israel L.E., Park P.H., Alexander M.H., Poojan S., Cao Q., Solomon B., Padron Z.M., Dyer J.A., Mellerio J.E., McGrath J.A., Palisson F., Salas-Alanis J., Han L., South A.P. Antiviral drugs prolong survival in murine recessive dystrophic epidermolysis bullosa. (2024). EMBO Molecular Medicine. Mar 10. doi: 10.1038/s44321-024-00048-8. Epub ahead of print. PMID: 38462666.

Ver abstract

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare inherited skin disease characterized by defects in type VII collagen leading to a range of fibrotic pathologies resulting from skin fragility, aberrant wound healing, and altered dermal fibroblast physiology. Using a novel in vitro model of fibrosis based on endogenously produced extracellular matrix, we screened an FDA-approved compound library and identified antivirals as a class of drug not previously associated with anti-fibrotic action. Preclinical validation of our lead hit, daclatasvir, in a mouse model of RDEB demonstrated significant improvement in fibrosis as well as overall quality of life with increased survival, weight gain and activity, and a decrease in pruritus-induced hair loss. Immunohistochemical assessment of daclatasvir-treated RDEB mouse skin showed a reduction in fibrotic markers, which was supported by in vitro data demonstrating TGFβ pathway targeting and a reduction of total collagen retained in the extracellular matrix. Our data support the clinical development of antivirals for the treatment of patients with RDEB and potentially other fibrotic diseases.

Keywords: Antivirals; Collagen; Drug Repurposing; Fibrosis; Recessive Dystrophic Epidermolysis Bullosa.

Bremer J., Pas H.H., Diercks G.F.H., Meijer H.J., van der Molen S.M., Nijenhuis A.M., van Nijen-Vos L.L..,. Morandé P, Yubero MJ, Palisson F, Fuentes I., Pasmooij A.M.G. Patients suffering from dystrophic epidermolysis bullosa are prone to developing autoantibodies against skin proteins: A longitudinal confirmational study. (2024). Experimental Dermatology.33(2):e15035.

Ver abstract

Epidermolysis bullosa (EB) is a heritable skin blistering disease caused by variants in genes coding for proteins that secure cell-cell adhesion and attachment of the epidermis to the dermis. Interestingly, several proteins involved in inherited EB are also associated with autoimmune blistering diseases (AIBD). In this study, we present a long-term follow-up of 15 patients suffering from recessive dystrophic or junctional EB. From these patients, 62 sera were analysed for the presence of autoantibodies associated with AIBD. We show that patients suffering from recessive dystrophic EB (RDEB) are more susceptible to developing autoantibodies against skin proteins than patients suffering from junctional EB (70% vs. 20%, respectively). Interestingly, no correlation with age was observed. Most patients showed reactivity to Type XVII collagen/linear IgA bullous dermatosis autoantigen (n = 5; 33%), followed by BP230 (n = 4; 27%), Type VII collagen (n = 4; 27%) and laminin-332 (n = 1; 7%). The pathogenicity of these autoantibodies remains a subject for future experiments.

Keywords: Type VII collagen; autoantibodies; dystrophic epidermolysis bullosa; junctional epidermolysis bullosa; serological follow-up.

De Gregorio C., Catalán E., Garrido G., Morandé P., Bennett J.C., Muñoz C., Cofré G., Huang Y., Cuadra B., Murgas P., Calvo M., Altermatt F., Yubero M.J., Palisson F., South A.P., Ezquer M., Fuentes I. Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions. (2023). Biological Research. 56(1):23.

Ver abstract

Background: Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the COL7A1 gene, coding for type VII collagen (C7), an important component of anchoring fibrils in the basement membrane of the epidermis. RDEB patients suffer from skin fragility starting with blister formation and evolving into chronic wounds, inflammation and skin fibrosis, with a high risk of developing aggressive skin carcinomas. Restricted therapeutic options are limited by the lack of in vitro models of defective wound healing in RDEB patients.

Results: In order to explore a more efficient, non-invasive in vitro model for RDEB studies, we obtained patient fibroblasts derived from discarded dressings) and examined their phenotypic features compared with fibroblasts derived from non-injured skin of RDEB and healthy-donor skin biopsies. Our results demonstrate that fibroblasts derived from RDEB chronic wounds (RDEB-CW) displayed characteristics of senescent cells, increased myofibroblast differentiation, and augmented levels of TGF-β1 signaling components compared to fibroblasts derived from RDEB acute wounds and unaffected RDEB skin as well as skin from healthy-donors. Furthermore, RDEB-CW fibroblasts exhibited an increased pattern of inflammatory cytokine secretion (IL-1β and IL-6) when compared with RDEB and control fibroblasts. Interestingly, these aberrant patterns were found specifically in RDEB-CW fibroblasts independent of the culturing method, since fibroblasts obtained from dressing of acute wounds displayed a phenotype more similar to fibroblasts obtained from RDEB normal skin biopsies.

Conclusions: Our results show that in vitro cultured RDEB-CW fibroblasts maintain distinctive cellular and molecular characteristics resembling the inflammatory and fibrotic microenvironment observed in RDEB patients’ chronic wounds. This work describes a novel, non-invasive and painless strategy to obtain human fibroblasts chronically subjected to an inflammatory and fibrotic environment, supporting their use as an accessible model for in vitro studies of RDEB wound healing pathogenesis. As such, this approach is well suited to testing new therapeutic strategies under controlled laboratory conditions.

Keywords: Chronic Wounds; Fibrosis; Recessive Dystrophic Epidermolysis Bullosa; Skin fibroblast; Wound Dressing.

Fuentes I., Yubero MJ., Morandé P., Varela C., Oróstica K., Acevedo F., Rebolledo-Jaramillo B., Arancibia E., Porte L., Palisson F. Longitudinal study of wound healing status and bacterial colonisation of Staphylococcus aureus and Corynebacterium diphtheriae in epidermolysis bullosa patients. (2023). International Wound Journal. 20(3):774-783.

Ver abstract

Epidermolysis bullosa (EB) is an inherited disorder characterised by skin fragility and the appearance of blisters and wounds. Patient wounds are often colonised or infected with bacteria, leading to impaired healing, pain and high risk of death by sepsis. Little is known about the impact of bacterial composition and susceptibility in wound resolution, and there is a need for longitudinal studies to understand healing outcomes with different types of bacterial colonisation. A prospective longitudinal study of 70 wounds from 15 severe EB patients (Junctional and Recessive Dystrophic EB) from Chile. Wounds were selected independently of their infected status. Wound cultures, including bacterial species identification, composition and Staphylococcus aureus (SA) antibiotic susceptibility were registered. Wounds were separated into categories according to their healing capacity, recognising chronic, and healing wounds. Hundred-one of the 102 wound cultures were positive for bacterial growth. From these, 100 were SA-positive; 31 were resistant to Ciprofloxacin (31%) and only seven were methicillin-resistant SA (7%). Ciprofloxacin-resistant SA was found significantly predominant in chronic wounds (**P < .01). Interestingly, atoxigenic Corynebacterium diphtheriae (CD) was identified and found to be the second most abundant recovered bacteria (31/101), present almost always in combination with SA (30/31). CD was only found in Recessive Dystrophic EB patients and not related to wound chronicity. Other less frequent bacterial species found included Pseudomonas aeruginosa, Streptococus spp. and Proteus spp. Infection was negatively associated with the healing status of wounds.

Cao Q, Tartaglia G, Alexander M, Park PH, Poojan S, Farshchian M, Fuentes I, Chen M, McGrath JA, Palisson F, Salas-Alanis J, South AP. Collagen VII maintains proteostasis in dermal fibroblasts by scaffolding TANGO1 cargo. (2022). Matrix Biology. 111:226-244.

Ver abstract

Lack of type VII collagen (C7) disrupts cellular proteostasis yet the mechanism remains undescribed. By studying the relationship between C7 and the extracellular matrix (ECM)-associated proteins thrombospondin-1 (TSP1), type XII collagen (C12) and tissue transglutaminase (TGM2) in primary human dermal fibroblasts from multiple donors with or without the genetic disease recessive dystrophic epidermolysis bullosa (RDEB) (n=31), we demonstrate that secretion of each of these proteins is increased in the presence of C7. In dermal fibroblasts isolated from patients with RDEB, where C7 is absent or defective, association with the COPII outer coat protein SEC31 and ultimately secretion of each of these ECM-associated proteins is reduced and intracellular levels are increased. In RDEB fibroblasts, overall collagen secretion (as determined by the levels of hydroxyproline in the media) is unchanged while traffic from the ER to Golgi of TSP1, C12 and TGM2 occurs in a type I collagen (C1) dependent manner. In normal fibroblasts association of TSP1, C12 and TGM2 with the ER exit site transmembrane protein Transport ANd Golgi Organization-1 (TANGO1) as determined by proximity ligation assays, requires C7. In the absence of wild-type C7, or when ECM-associated proteins are overexpressed, C1 proximity and intracellular levels increase resulting in elevated cellular stress responses and elevated TGFβ signaling. Collectively, these data demonstrate a role for C7 in loading COPII vesicle cargo and provides a mechanism for disrupted proteostasis, elevated cellular stress and increased TGFβ signaling in patients with RDEB. Furthermore, our data point to a threshold of cargo loading that can be exceeded with increased protein levels leading to pathological outcomes in otherwise normal cells.

Keywords: Collagen VII; ER stress; TANGO1; and TGFβ signaling; recessive dystrophic epidermolysis bullosa; thrombospondin.

Ramovs V., Janssen H., Fuentes I., Pitaval A., Rachidi W., Chuva de Sousa Lopes S.M., Freund C., Gidrol X., Mummery C.M. & Raymond K. Characterization of the epidermal-dermal junction in human induced pluripotent stem cell-derived skin organoids. (2022). Stem Cells Reports, 7(6):1279-1288.

Ver abstract

Human induced pluripotent stem cell (hiPSC)-derived hair-bearing skin organoids offer exciting new possibilities for modeling diseases like epidermolysis bullosa (EB). These inherited diseases affect 1 in 30,000 people worldwide and result from perturbed expression and/or structure of components of the epidermal-dermal junction (EDJ). To establish whether hiPSC-derived skin organoids might be able to capture salient features of EB, it is thus important to characterize their EDJ. Here, we report successful generation of hair-bearing skin organoids from two hiPSC lines that exhibited fully stratified interfollicular epidermis. Using immunofluorescence and electron microscopy, we showed that basal keratinocytes in organoids adhere to laminin-332 and type IV collagen-rich basement membrane via type I hemidesmosomes and integrin β1-based adhesion complexes. Importantly, we demonstrated that EDJs in organoids are almost devoid of type VII collagen, a fibril that mediates anchorage of the epidermis to dermis. This should be considered when using skin organoids for EB modeling.

Keywords: collagen; epidermal-dermal junction; hiPSC-derived hair-bearing skin organoids.

Schmidt D., Díaz D., Muñoz D., Espinoza F., Nystrom A., Fuentes I., Ezquer M., Bennett D.L. & Calvo M. (2022). Characterisation of the pathophysiology of neuropathy and sensory dysfunction in a mouse model of recessive dystrophic epidermolysis bullosa. Pain, 10.1097.

Ver abstract

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genetic condition in which mutations in the type VII collagen gene ( COL7A1 ) lead to decreased expression of this anchoring protein of the skin, causing the loss of stability at the dermo-epidermal junction. Most patients with RDEB experience neuropathic pain and itch due to the development of a small fibre neuropathy, characterised by decreased intraepidermal innervation and thermal hypoaesthesia. To understand the physiopathology of this neuropathy, we used a mouse model of RDEB (Col7a1 flNeo/flNeo ) and performed a detailed characterisation of the somatosensory system. Col7a1 flNeo/flNeo mice showed a decrease in heat sensitivity, an increase in spontaneous scratching, and a significant decrease in intraepidermal nerve fibre density in the hindpaw; these changes were distal because there was no significant loss of unmyelinated or myelinated fibres in the nerve trunk. Of interest, we observed a decrease in axon diameter in both myelinated and unmyelinated fibres. This axonal damage was not associated with inflammation of the dorsal root ganglion or central projection targets at the time of assessment. These results suggest that in RDEB, there is a distal degeneration of axons produced by exclusive damage of small fibres in the epidermis, and in contrast with traumatic and acute neuropathies, it does not induce sustained neuroinflammation. Thus, this animal model emphasizes the importance of a healthy cutaneous environment for maintenance of epidermal innervation and faithfully replicates the pathology in humans, offering the opportunity to use this model in the development of treatments for pain for patients with RDEB.

Olivares B., Martínez F, Ezquer M., Morales B.J, Fuentes I., Calvo M. & Campodónico P.R. (2022). Betaine-urea deep eutectic solvent improves imipenem antibiotic activity. Journal of Molecular Liquids, 350, 118551.

Ver abstract

Beta-lactam antibiotics are highly unstable in aqueous media, which may lead to subclinical concentrations, antimicrobial resistance and therapeutic failure. In previous work we demonstrated that a natural deep eutectic solvent consisting of betaine and urea (BU) is capable of improving the stability of some beta-lactams, including imipenem (IMP), the most unstable antibiotic of the family. Here, IMP-BU was studied by selective protonic Nuclear Overhauser Effect Spectroscopy Magnetic Resonance (H1 NOESY NMR) to gain insight into the mechanism by which BU protects IMP. The kinetics of IMP release and its antibacterial activity were evaluated in diffusional, time-kill and antibiofilm assays. It was found that BU is a protective matrix which allows a fast release of IMP, resulting in superior antibacterial activity when compared to IMP in aqueous solution, both against bacteria growing in planktonic form and in biofilms. Furthermore, it was shown that BU is nontoxic when evaluated in fibroblast primary cell cultures and in organotypic skin cultures, and is not immunogenic when tested in vitro in macrophage cultures, suggesting that BU has potential application as a biomaterial or excipient.

Enlaces