RESUMEN
Chromosome damage combined with defective recombinase activity has been widely considered to render cells inviable, owing to deficient double-strand break repair. However, temperature-sensitive recAts polA cells grow well upon induction of DNA damage and supplementation with catalase at restrictive temperatures. These treatments reduce intracellular reactive oxygen species (ROS) levels, which suggests that recAts polA cells are susceptible to ROS, but not chronic chromosome damage. Therefore, we investigated whether polA cells can tolerate a complete lack of recombinase function. We introduced a ΔrecA allele in polA cells in the presence or absence of the hslO-encoding redox molecular chaperon Hsp33 expression plasmid. Induction of the hslO gene with IPTG resulted in increased cell viability in ΔrecA polA cells with the hslO expression plasmid. ΔrecA polA cells in the absence of the hslO expression plasmid showed rich medium sensitivity with increasing ROS levels. Adding catalase to the culture medium considerably rescued growth arrest and decreased ROS. These results suggest that hslO expression manages oxidative stress to an acceptable level in cells with oxidative damage and rescues cell growth. Overall, ROS may regulate several processes, from damage response to cell division, via ROS-sensitive cell metabolism.
Asunto(s)
Daño del ADN , Estrés Oxidativo , Catalasa/genética , Catalasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Recombinasas/metabolismoAsunto(s)
Pénfigo , Humanos , Desmocolinas , Desmogleína 1 , Desmogleína 3 , Anticuerpos , AutoanticuerposAsunto(s)
Autoanticuerpos/sangre , Conjuntiva/patología , Desmocolinas/inmunología , Enfermedades de la Boca/inmunología , Pénfigo/inmunología , Oftalmopatías/etiología , Oftalmopatías/patología , Femenino , Humanos , Enfermedades de la Boca/complicaciones , Enfermedades de la Boca/patología , Mucosa Bucal/inmunología , Mucosa Bucal/patología , Pénfigo/complicaciones , Adulto JovenRESUMEN
Psoriasis is characterized by excessive growth and aberrant differentiation of epidermal keratinocytes due to persistent inflammation. However, the underlying mechanism that triggers immune activation in psoriasis is not clear. In this study, we explored excessive DNA as a potential trigger of psoriasis using cultured human keratinocytes and psoriatic skin tissues. We demonstrated that human genomic DNA fragments induced tumour necrosis factor (TNF)-α expression, hyperproliferation and over-expression of heparin-binding epidermal-like growth factor (HB-EGF) and transforming growth factor (TGF)-α, accompanied by defective expression of keratins 1 and 10 in cultured normal human epidermal keratinocytes, which have a similar phenotype to that of keratinocytes in psoriatic skin lesions. In psoriatic lesions, we found high levels of double-stranded (ds)DNA fragments, accompanying keratinocytes expressing Ki-67, HB-EGF and TNF-α. In addition, we showed that 1,25-dihydroxyvitamin D3 inhibited genomic DNA fragment-induced TNFA and interleukin-1ß (IFNB) expression in human keratinocytes, and an intact function of cathelicidin anti-microbial peptide (CAMP) was required for this effect. These results suggest that excessive dsDNA fragments probably act as a risk factor for immune activation in psoriasis, and the active form of vitamin D can prevent genomic DNA-mediated skin inflammation via CAMP.
Asunto(s)
Proliferación Celular , Fragmentación del ADN , ADN/metabolismo , Queratinocitos/metabolismo , Psoriasis/metabolismo , Línea Celular , Factor de Crecimiento Similar a EGF de Unión a Heparina/biosíntesis , Humanos , Interleucina-1beta/biosíntesis , Queratinocitos/patología , Antígeno Ki-67/biosíntesis , Psoriasis/patología , Factor de Crecimiento Transformador alfa/biosíntesis , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
BACKGROUND: Scabies is a common parasitic skin condition that causes considerable morbidity globally. Clinical and epidemiological research for scabies has been limited by a lack of standardization of diagnostic methods. OBJECTIVES: To develop consensus criteria for the diagnosis of common scabies that could be implemented in a variety of settings. METHODS: Consensus diagnostic criteria were developed through a Delphi study with international experts. Detailed recommendations were collected from the expert panel to define the criteria features and guide their implementation. These comments were then combined with a comprehensive review of the available literature and the opinion of an expanded group of international experts to develop detailed, evidence-based definitions and diagnostic methods. RESULTS: The 2020 International Alliance for the Control of Scabies (IACS) Consensus Criteria for the Diagnosis of Scabies include three levels of diagnostic certainty and eight subcategories. Confirmed scabies (level A) requires direct visualization of the mite or its products. Clinical scabies (level B) and suspected scabies (level C) rely on clinical assessment of signs and symptoms. Evidence-based, consensus methods for microscopy, visualization and clinical symptoms and signs were developed, along with a media library. CONCLUSIONS: The 2020 IACS Criteria represent a pragmatic yet robust set of diagnostic features and methods. The criteria may be implemented in a range of research, public health and clinical settings by selecting the appropriate diagnostic levels and subcategories. These criteria may provide greater consistency and standardization for scabies diagnosis. Validation studies, development of training materials and development of survey methods are now required. What is already known about this topic? The diagnosis of scabies is limited by the lack of accurate, objective tests. Microscopy of skin scrapings can confirm the diagnosis, but it is insensitive, invasive and often impractical. Diagnosis usually relies on clinical assessment, although visualization using dermoscopy is becoming increasingly common. These diagnostic methods have not been standardized, hampering the interpretation of findings from clinical research and epidemiological surveys, and the development of scabies control strategies. What does this study add? International consensus diagnostic criteria for common scabies were developed through a Delphi study with global experts. The 2020 International Alliance for the Control of Scabies (IACS) Criteria categorize diagnosis at three levels of diagnostic certainty (confirmed, clinical and suspected scabies) and eight subcategories, and can be adapted to a range of research and public health settings. Detailed definitions and figures are included to aid training and implementation. The 2020 IACS Criteria may facilitate the standardization of scabies diagnosis.
Asunto(s)
Escabiosis , Administración Tópica , Consenso , Humanos , Escabiosis/diagnóstico , Escabiosis/epidemiología , PielAsunto(s)
Paraplejía/complicaciones , Penfigoide Ampolloso/patología , Traumatismos de la Médula Espinal/complicaciones , Biopsia , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/uso terapéutico , Femenino , Humanos , Metotrexato/administración & dosificación , Metotrexato/uso terapéutico , Persona de Mediana Edad , Penfigoide Ampolloso/sangre , Penfigoide Ampolloso/diagnóstico , Penfigoide Ampolloso/tratamiento farmacológico , Resultado del TratamientoAsunto(s)
Síndromes Paraneoplásicos , Pénfigo , Anticuerpos , Humanos , Pénfigo/tratamiento farmacológicoRESUMEN
BACKGROUND: Anti-laminin-γ1 (lam-γ1) pemphigoid, a recently described immunobullous disorder sharing immune serological features of bullous pemphigoid and epidermolysis bullosa acquisita (EBA), is characterized by the detection of serum IgG autoantibodies against the lam-γ1 chain, a 200 kDa heterotrimeric component of the dermal-epidermal junction (DEJ). OBJECTIVE: The aim of the study was to develop an easy-to-perform and reliable assay for the serological detection of anti-lam-γ1 IgG autoantibodies. The clinical appearance alone is not sufficient to establish diagnosis of anti-lam-γ1 pemphigoid and rather requires immune serological evidence of (i) IgG reactivity against the dermal portion of salt-split human skin; (ii) exclusion of IgG against other components of the DEJ; and (iii) IgG reactivity with a 200 kDa protein of dermal extracts by immunoblot analysis (IB). METHODS: The sera of 55 patients with anti-lam-γ1 pemphigoid were tested by IB with two recombinant heterotrimers, laminin 111 (lam-111) and laminin 421 (lam-421), as well as with a recombinant lam-γ1 chain monomer. Additionally, a total of 41 control sera from patients with EBA (n = 15), psoriasis vulgaris (PV; n = 14), and healthy controls (HC; n = 12) were tested. RESULTS: Immunoblot analysis revealed a positive reactivity with lam-111 and/or lam-421 in 46/55 (84%) of anti-lam-γ1 pemphigoid sera. Moreover, 8/9 of the initially non-reactive sera were positive with the lam-γ1 monomer, leading to an overall sensitivity of 98.2%. Analyses of 41 control sera with the three lam-γ1 recombinants led to a specificity of 88%. Specifically, 3/15 EBA sera, 1/14 PV serum and 1/12 HC serum reacted with the lam-γ1 monomer while only the 3 EBA sera reacted with lam-421. CONCLUSIONS: Here we show a novel two-step IB assay using the two recombinant laminin trimers and lam-γ1 chain monomer for the detection of anti-lam-γ1 serum IgG with high sensitivity and specificity. This assay will facilitate the diagnosis and further characterization of this disease.
Asunto(s)
Autoanticuerpos/sangre , Inmunoglobulina G/sangre , Laminina/inmunología , Penfigoide Ampolloso/diagnóstico , Penfigoide Ampolloso/inmunología , Dermatitis por Contacto , Femenino , Humanos , Immunoblotting/métodos , Masculino , Persona de Mediana Edad , Penfigoide Ampolloso/sangre , Proteínas Recombinantes , Pruebas SerológicasAsunto(s)
Pénfigo/diagnóstico , Piel/patología , Adolescente , Humanos , Masculino , Mucosa Bucal/patología , Pénfigo/patologíaRESUMEN
BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare pemphigoid disease involving autoantibodies to type VII collagen (COL7), a major structural component of anchoring fibrils. IgE autoantibodies to type XVII collagen (BP180) have been identified in bullous pemphigoid (BP), the prototype of pemphigoid diseases. Although the pathogenic relevance of IgG anti-COL7 has been investigated, that of IgE in EBA remains unclear. OBJECTIVES: To reveal the presence and pathogenic relevance of IgE anti-COL7 in EBA. METHODS: We examined IgE antibodies in 109 patients with EBA by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA). RESULTS: IIF with normal human skin revealed IgE reactivity in the basement membrane zone in 29 (26·6%) cases. To verify whether the IgE antibodies were specific to COL7, we performed IIF with 21 clearly positive cases and the skin of a patient with dystrophic EBA, which does not involve COL7. All cases showed negative results, indicating that IgE antibodies were specific to COL7. In a modified IgG COL7 ELISA for IgE, 16 (14·7%) cases were positive (three and 13 cases were negative and positive on IIF, respectively). We compared anti-COL7 IgG and IgE, and found a weak but significant correlation (r = 0·459, P < 0·001). EBA is clinically divided into a mechanobullous (MB; noninflammatory) type and an inflammatory (INF) type resembling BP. Of the IIF-positive cases, 11 of 30 (37%) had INF and nine of 48 (19%) had MB. CONCLUSIONS: This study is the first to demonstrate the presence of circulating anti-COL7 IgE in patients with EBA, which may correlate with the clinical phenotype.
Asunto(s)
Autoanticuerpos/sangre , Colágeno Tipo VII/inmunología , Epidermólisis Ampollosa Adquirida/inmunología , Inmunoglobulina E/sangre , Autoanticuerpos/inmunología , Autoanticuerpos/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática , Epidermólisis Ampollosa Adquirida/sangre , Epidermólisis Ampollosa Adquirida/diagnóstico , Epidermólisis Ampollosa Adquirida/patología , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunoglobulina E/inmunología , Inmunoglobulina E/aislamiento & purificación , Piel/inmunología , Piel/patologíaRESUMEN
We report a unique case of a Japanese woman with herpetiform pemphigus (HP) who had IgG autoantibodies reactive with nondesmosomal sites of keratinocytes and presented characteristic transmission electron microscopic (TEM) findings of various-sized vacuoles in keratinocytes without acantholysis. The patient presented with pruritic annular oedematous erythemas with small blisters lining the margins on the trunk and extremities. Histopathological examinations showed intraepidermal blisters with prominent infiltrations of eosinophils. Direct and indirect immunofluorescence tests revealed the presence of in vivo bound and circulating IgG autoantibodies to the keratinocyte cell surfaces. However, enzyme-linked immunosorbent assays for desmoglein (Dsg) 1, Dsg3 and desmocollins 1-3 showed negative results. Immunoblotting using the full-length human Dsg1 recombinant protein showed a positive band. TEM examination showed various-sized vacuoles squashing the nuclei in many keratinocytes, resulting in rupture of the cells. Immunoelectron microscopic examination revealed IgG deposition over the entire keratinocyte cell surfaces, which spared the desmosomes. IgG antibodies were also present on the inside walls of the vacuoles around the nuclei of keratinocytes and on the cell surfaces of infiltrating eosinophils. This patient also had marked eosinophilia and high levels of thymus and activation-regulated chemokine and interleukin-5 in the serum. These results indicated a novel autoantigen on the nondesmosomal keratinocyte cell surfaces and the pathogenesis of bullous spongiotic change with inflammation in HP.
Asunto(s)
Dermatitis Herpetiforme/diagnóstico , Queratinocitos/ultraestructura , Pénfigo/diagnóstico , Piel/patología , Anciano , Dermatitis Herpetiforme/patología , Desmosomas/ultraestructura , Femenino , Humanos , Queratinocitos/citología , Microscopía Electrónica de Transmisión , Pénfigo/patología , Piel/citología , Vacuolas/ultraestructuraAsunto(s)
Desmogleína 1/inmunología , Desmogleína 1/metabolismo , Pénfigo/inmunología , Adulto , Autoanticuerpos , Humanos , Masculino , Pénfigo/patologíaAsunto(s)
Autoanticuerpos/inmunología , Enfermedades Autoinmunes/etiología , Linfoma Folicular/complicaciones , Linfoma no Hodgkin/complicaciones , Pénfigo/etiología , Anciano de 80 o más Años , Autoanticuerpos/sangre , Autoantígenos/inmunología , Enfermedades Autoinmunes/inmunología , Linfocitos T CD8-positivos/química , Linfocitos T CD8-positivos/inmunología , Desmogleína 1/inmunología , Resultado Fatal , Femenino , Humanos , Linfoma Folicular/diagnóstico , Linfoma Folicular/inmunología , Linfoma Folicular/patología , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/inmunología , Linfoma no Hodgkin/patología , Pénfigo/inmunología , PlaquinasRESUMEN
BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare, potentially devastating autoimmune disease of the skin. IgG autoantibodies directed against type VII collagen (Col7), the major component of anchoring fibrils, induce skin fragility leading to cutaneous and mucocutaneous blister formation, which is mostly of a scarring phenotype. Thus, powerful and reproducible diagnostic assays are critical to establish the diagnosis of EBA early to avoid irreversible sequelae. OBJECTIVES: The present international, retrospective multicentre study included a large cohort of patients with EBA and evaluated the diagnostic power of four different diagnostic assays for the detection of anti-Col7 IgG autoantibodies. METHODS: Overall, 95 EBA sera and 200 control sera consisting of 100 bullous pemphigoid sera, 50 pemphigus vulgaris sera and 50 sera of healthy controls were tested for anti-Col7 IgG autoantibodies using indirect immunofluorescence (IIF), two commercial enzyme-linked immunosorbent assay (ELISA) systems and Western blot (WB) analysis. EBA sera were taken from patients with positive direct immunofluorescence and IgG reactivity in at least one of the immunoserological assays (IIF, ELISA, WB). RESULTS: A Col7-NC1/NC2 ELISA (MBL, Nagoya, Japan) showed the highest sensitivity (97·9%), followed by a Col7-NC1 ELISA (Euroimmun, Lübeck, Germany) (89·5%), WB with Col7-NC1 (85·3%), and IIF on saline-split human skin (74·7%). The specificities of both ELISA systems were comparable (NC1 98·7%, NC1/NC2 99·3%). Furthermore, WB was more sensitive than IIF, which was more specific. CONCLUSIONS: The two commercially available ELISA systems allow for a highly sensitive and specific diagnosis of EBA. The sensitivity of the Col7-NC1/NC2 ELISA is significantly higher compared with the ELISA based on the Col7-NC1 domain only.