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1.
Br J Dermatol ; 184(5): 840-848, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32920824

RESUMEN

BACKGROUND: Economic evidence for vitiligo treatments is absent. OBJECTIVES: To determine the cost-effectiveness of (i) handheld narrowband ultraviolet B (NB-UVB) and (ii) a combination of topical corticosteroid (TCS) and NB-UVB compared with TCS alone for localized vitiligo. METHODS: Cost-effectiveness analysis alongside a pragmatic, three-arm, placebo-controlled randomized controlled trial with 9 months' treatment. In total 517 adults and children (aged ≥ 5 years) with active vitiligo affecting < 10% of skin were recruited from secondary care and the community and were randomized 1: 1: 1 to receive TCS, NB-UVB or both. Cost per successful treatment (measured on the Vitiligo Noticeability Scale) was estimated. Secondary cost-utility analyses measured quality-adjusted life-years using the EuroQol 5 Dimensions 5 Levels for those aged ≥ 11 years and the Child Health Utility 9D for those aged 5 to < 18 years. The trial was registered with number ISRCTN17160087 on 8 January 2015. RESULTS: The mean ± SD cost per participant was £775 ± 83·7 for NB-UVB, £813 ± 111.4 for combination treatment and £600 ± 96·2 for TCS. In analyses adjusted for age and target patch location, the incremental difference in cost for combination treatment compared with TCS was £211 (95% confidence interval 188-235), corresponding to a risk difference of 10·9% (number needed to treat = 9). The incremental cost was £1932 per successful treatment. The incremental difference in cost for NB-UVB compared with TCS was £173 (95% confidence interval 151-196), with a risk difference of 5·2% (number needed to treat = 19). The incremental cost was £3336 per successful treatment. CONCLUSIONS: Combination treatment, compared with TCS alone, has a lower incremental cost per additional successful treatment than NB-UVB only. Combination treatment would be considered cost-effective if decision makers are willing to pay £1932 per additional treatment success.


Asunto(s)
Terapia Ultravioleta , Vitíligo , Corticoesteroides , Adulto , Niño , Terapia Combinada , Análisis Costo-Beneficio , Humanos , Resultado del Tratamiento , Vitíligo/tratamiento farmacológico
2.
Br J Dermatol ; 184(5): 828-839, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33006767

RESUMEN

BACKGROUND: Evidence for the effectiveness of vitiligo treatments is limited. OBJECTIVES: To determine the effectiveness of (i) handheld narrowband UVB (NB-UVB) and (ii) a combination of potent topical corticosteroid (TCS) and NB-UVB, compared with TCS alone, for localized vitiligo. METHODS: A pragmatic, three-arm, placebo-controlled randomized controlled trial (9-month treatment, 12-month follow-up). Adults and children, recruited from secondary care and the community, aged ≥ 5 years and with active vitiligo affecting < 10% of skin, were randomized 1 : 1 : 1 to receive TCS (mometasone furoate 0·1% ointment + dummy NB-UVB), NB-UVB (NB-UVB + placebo TCS) or a combination (TCS + NB-UVB). TCS was applied once daily on alternating weeks; NB-UVB was administered on alternate days in escalating doses, adjusted for erythema. The primary outcome was treatment success at 9 months at a target patch assessed using the participant-reported Vitiligo Noticeability Scale, with multiple imputation for missing data. The trial was registered with number ISRCTN17160087 on 8 January 2015. RESULTS: In total 517 participants were randomized to TCS (n = 173), NB-UVB (n = 169) and combination (n = 175). Primary outcome data were available for 370 (72%) participants. The proportions with target patch treatment success were 17% (TCS), 22% (NB-UVB) and 27% (combination). Combination treatment was superior to TCS: adjusted between-group difference 10·9% (95% confidence interval 1·0%-20·9%; P = 0·032; number needed to treat = 10). NB-UVB alone was not superior to TCS: adjusted between-group difference 5·2% (95% CI - 4·4% to 14·9%; P = 0·29; number needed to treat = 19). Participants using interventions with ≥ 75% expected adherence were more likely to achieve treatment success, but the effects were lost once treatment stopped. Localized grade 3 or 4 erythema was reported in 62 (12%) participants (including three with dummy light). Skin thinning was reported in 13 (2·5%) participants (including one with placebo ointment). CONCLUSIONS: Combination treatment with home-based handheld NB-UVB plus TCS is likely to be superior to TCS alone for treatment of localized vitiligo. Combination treatment was relatively safe and well tolerated but was successful in only around one-quarter of participants.


Asunto(s)
Terapia Ultravioleta , Vitíligo , Corticoesteroides , Adulto , Niño , Terapia Combinada , Humanos , Furoato de Mometasona , Pomadas , Resultado del Tratamiento , Vitíligo/tratamiento farmacológico
3.
J Eur Acad Dermatol Venereol ; 32(12): 2275-2283, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29972710

RESUMEN

BACKGROUND: Psychological interventions are recommended as part of routine management of vitiligo. However, the development and effectiveness of such interventions have been rarely addressed. This study aimed to identify key components for a psychological intervention for people with vitiligo. This is the first time perspectives of people with vitiligo, and healthcare professionals (HCPs) have been directly explored to inform intervention content and delivery. OBJECTIVES: To identify 1. which psychological difficulties are highlighted that can be targeted by an intervention; 2. what is important in terms of intervention content and delivery. METHODS: Web-based questionnaires containing both quantitative and qualitative items were completed by people with vitiligo and HCPs. Questionnaires collected data from people with vitiligo on demographics, clinical features, psychological difficulties and priority areas for psychological interventions, including ideas on delivery and content. HCPs questionnaires collected data on psychological difficulties reported, use of psychological interventions and suitability within health services. Quantitative data were analysed using descriptive statistics, and qualitative data utilized thematic framework analysis. RESULTS: A total of 100 people with vitiligo (66% female, 92% Caucasian) and 39 HCPs (54% dermatologists) participated. Key areas of difficulty were the impact of vitiligo, coping, issues with appearance/body image and the sun, and medical interactions. Vitiligo on sensitive sites was associated with more psychological impact. Interventions directed at increasing acceptance, confidence and self-esteem, as well as managing embarrassment, were important. These issues could be managed through interventions such as cognitive behavioural therapy, mindfulness and acceptance and commitment therapy. Both people with vitiligo and HCPs favoured individual interventions. CONCLUSION: Vitiligo has significant impact, requiring ongoing psychosocial support. There is a strong need for a psychoeducational intervention with focus on acceptance and managing social impact. The results of this study are the first steps to informing the development of a patient-centred psychological intervention.


Asunto(s)
Terapia de Aceptación y Compromiso , Adaptación Psicológica , Atención Plena , Vitíligo/psicología , Vitíligo/terapia , Actitud del Personal de Salud , Imagen Corporal/psicología , Desconcierto , Femenino , Humanos , Internet , Masculino , Investigación Cualitativa , Autoeficacia , Luz Solar/efectos adversos , Encuestas y Cuestionarios , Reino Unido
4.
Br J Dermatol ; 174(5): 962-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26686510

RESUMEN

Vitiligo affects around 1% of the world's population. Despite it being relatively common, there is still no effective treatment. The objective of this study was to update the Cochrane systematic review of randomized clinical trials (RCTs) to evaluate the efficacy of treatments for vitiligo. We carried out searches of a range of databases to October 2013 for RCTs of interventions for vitiligo regardless of language or publication status. At least two reviewers independently assessed study eligibility and methodological quality and extracted data using data extraction forms approved by the Cochrane Skin Group. Our primary outcomes of interest were quality of life, > 75% repigmentation and adverse effects. We retrieved 96 studies, of which 39 were new studies, with an overall total of 4512 participants. Repigmentation was assessed in all studies, although only five reported on all three of our primary outcomes. Regarding our two secondary outcomes, six studies measured cessation of spread but none assessed long-term permanence of repigmentation at 2 years' follow-up. Most of the studies evaluated combination treatments, which generally showed better repigmentation than monotherapies. Of the new studies, seven were surgical interventions. The majority of the studies had fewer than 50 participants. The quality of the studies was poor to moderate at best. Very few studies specifically included children or participants with segmental vitiligo. Five years after the last update of this review, there are still important variations in study design and outcome measures in clinical trials for vitiligo, limiting the evidence for the efficacy of different therapeutic options. The best evidence from individual trials showed short-term benefit from topical corticosteroids and various forms of ultraviolet radiation combined with topical preparations. Long-term follow-up and patient-rated outcomes should be incorporated into study design, and more studies should assess psychological interventions.


Asunto(s)
Vitíligo/terapia , Administración Cutánea , Administración Oral , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/efectos adversos , Procedimientos Quirúrgicos Dermatologicos/efectos adversos , Procedimientos Quirúrgicos Dermatologicos/métodos , Medicina Basada en la Evidencia , Humanos , Terapia PUVA/efectos adversos , Terapia PUVA/métodos , Psicoterapia/métodos , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
5.
Br J Dermatol ; 168(1): 5-19, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22860621

RESUMEN

The aetiopathogenic mechanisms of vitiligo are still poorly understood, and this has held back progress in diagnosis and treatment. Up until now, treatment guidelines have existed at national levels, but no common European viewpoint has emerged. This guideline for the treatment of segmental and nonsegmental vitiligo has been developed by the members of the Vitiligo European Task Force and other colleagues. It summarizes evidence-based and expert-based recommendations (S1 level).


Asunto(s)
Vitíligo/terapia , Administración Cutánea , Administración Oral , Corticoesteroides/administración & dosificación , Antioxidantes/uso terapéutico , Inhibidores de la Calcineurina , Lista de Verificación , Terapia Combinada , Fármacos Dermatológicos/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Fototerapia/métodos , Preparaciones para Aclaramiento de la Piel/uso terapéutico , Esteroides/administración & dosificación , Resultado del Tratamiento , Vitíligo/diagnóstico
6.
Br J Dermatol ; 167(4): 804-14, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22591025

RESUMEN

BACKGROUND: Relevant and reliable outcomes play a crucial role in the correct interpretation and comparison of the results of clinical trials. There is a lack of consensus around methods of assessment and outcome measures for vitiligo, which makes it difficult to compare results of randomized controlled trials (RCTs) and perform meta-analysis. OBJECTIVES: To describe the heterogeneity in outcome measures used in published RCTs of vitiligo treatments, and to report the most desirable outcomes from patients' and clinicians' perspectives. METHODS: We conducted a systematic review of outcome measures used in RCTs as well as a survey of the most desirable outcomes identified by patients and clinicians as part of a Vitiligo Priority Setting Partnership. RESULTS: Outcomes from 54 eligible trials were analysed and compared with outcomes suggested by patients and clinicians. In the systematic review, 25 different outcomes were reported. Only 22% of trials had clearly stated primary outcome measures. Repigmentation was the most frequently reported outcome in 96% of trials and was measured using 48 different scales. Only 9% of trials assessed quality of life. Thirteen per cent measured cessation of spreading of the disease and 17% of studies reported patients' opinions and satisfaction with the treatment. In contrast, out of 438 suggestions made by patients and clinicians, cosmetically acceptable repigmentation (rather than percentage of repigmentation) was the most desirable outcome (68%), followed by cessation of spread of vitiligo (15%), quality of life (8%) and maintenance of repigmentation (4%). CONCLUSIONS: We propose that future vitiligo trials should include repigmentation, cosmetic acceptability of results, global assessment of the disease, quality of life, maintenance of repigmentation, stabilization of vitiligo and side-effects. International consensus among clinicians, researchers and patients is needed to establish an agreed core outcome set for future vitiligo trials.


Asunto(s)
Vitíligo/diagnóstico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Médicos/psicología , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Índice de Severidad de la Enfermedad , Pigmentación de la Piel/efectos de los fármacos , Encuestas y Cuestionarios , Resultado del Tratamiento , Reino Unido , Vitíligo/tratamiento farmacológico
7.
Br J Dermatol ; 164(3): 530-6, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21128908

RESUMEN

BACKGROUND: Vitiligo is the most frequent depigmentation disorder of the skin and is cosmetically and psychologically devastating. A recently updated Cochrane systematic review 'Interventions for vitiligo' showed that the research evidence for treatment of vitiligo is poor, making it difficult to make firm recommendations for clinical practice. OBJECTIVES: To stimulate and steer future research in the field of vitiligo treatment, by identifying the 10 most important research areas for patients and clinicians. METHODS: A vitiligo priority setting partnership was established including patients, healthcare professionals and researchers with an interest in vitiligo. Vitiligo treatment uncertainties were gathered from patients and clinicians, and then prioritized in a transparent process, using a methodology advocated by the James Lind Alliance. RESULTS: In total, 660 treatment uncertainties were submitted by 461 participants. These were reduced to a list of the 23 most popular topics through an online/paper voting process. The 23 were then prioritized at a face-to-face workshop in London. The final list of the top 10 treatment uncertainties included interventions such as systemic immunosuppressants, topical treatments, light therapy, melanocyte-stimulating hormone analogues, gene therapy, and the impact of psychological interventions on the quality of life of patients with vitiligo. CONCLUSIONS: The top 10 research areas for the treatment of vitiligo provide guidance for researchers and funding bodies, to ensure that future research answers questions that are important both to clinicians and to patients.


Asunto(s)
Investigación Biomédica/organización & administración , Vitíligo/terapia , Humanos , Prevención Secundaria , Vitíligo/prevención & control
8.
Br J Dermatol ; 159(5): 1051-76, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19036036

RESUMEN

This detailed and user-friendly guideline for the diagnosis and management of vitiligo in children and adults aims to give high quality clinical advice, based on the best available evidence and expert consensus, taking into account patient choice and clinical expertise. The guideline was devised by a structured process and is intended for use by dermatologists and as a resource for interested parties including patients. Recommendations and levels of evidence have been graded according to the method developed by the Scottish Inter-Collegiate Guidelines Network. Where evidence was lacking, research recommendations were made. The types of vitiligo, process of diagnosis in primary and secondary care, and investigation of vitiligo were assessed. Treatments considered include offering no treatment other than camouflage cosmetics and sunscreens, the use of topical potent or highly potent corticosteroids, of vitamin D analogues, and of topical calcineurin inhibitors, and depigmentation with p-(benzyloxy)phenol. The use of systemic treatment, e.g. corticosteroids, ciclosporin and other immunosuppressive agents was analyzed. Phototherapy was considered, including narrowband ultraviolet B (UVB), psoralen with ultraviolet A (UVA), and khellin with UVA or UVB, along with combinations of topical preparations and various forms of UV. Surgical treatments that were assessed include full-thickness and split skin grafting, mini (punch) grafts, autologous epidermal cell suspensions, and autologous skin equivalents. The effectiveness of cognitive therapy and psychological treatments was considered. Therapeutic algorithms using grades of recommendation and levels of evidence have been produced for children and for adults with vitiligo.


Asunto(s)
Vitíligo/diagnóstico , Vitíligo/terapia , Adulto , Algoritmos , Antiinflamatorios/uso terapéutico , Niño , Medicina Basada en la Evidencia , Humanos , Inmunosupresores/uso terapéutico , Psicoterapia/métodos , Calidad de Vida , Terapia Ultravioleta/métodos , Vitíligo/psicología
9.
Cochrane Database Syst Rev ; (1): CD003263, 2006 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-16437451

RESUMEN

BACKGROUND: Around 1% of the world's population has vitiligo, which causes a loss of skin colour in patches. The methods currently available to treat vitiligo are largely unsatisfactory and vary widely between cultures and within health systems. OBJECTIVES: To assess the effects of interventions used to manage vitiligo. SEARCH STRATEGY: We searched the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, AMED and other databases (last searched September 2004). Reference lists of articles and conference proceedings were searched. Authors of reviews were contacted. SELECTION CRITERIA: Randomised controlled trials (RCTs). DATA COLLECTION AND ANALYSIS: At least two reviewers independently assessed study eligibility and methodological quality and carried out data extraction. The included studies compared different interventions and used different outcome measures so we considered it inappropriate to combine their results. MAIN RESULTS: Nineteen trials with a total of 1350 participants were included. The RCTs generally had low numbers of participants and only RCTs of repigmentation and not other methods of managing vitiligo were able to be included. In one study, potent topical steroids resulted in better repigmentation than placebo and they were also better than oral psoralens plus sunlight in another study (RR 4.70 95% CI 1.14 to 19.39) although their long-term use is limited by adverse effects. Two studies suggested that topical calcipotriol enhanced repigmentation rates from PUVAsol and PUVA when compared with placebo. Another two studies showed higher repigmentation rates with oral PUVAsol versus placebo plus sunlight (RR 19.20 95% CI 1.21 to 304.50 in 79 adults and RR 2.29 95% CI 1.14 to 4.58 in a study of 50 children). The safety of these interventions was poorly described and none of the studies was able to demonstrate long term benefits. Very few studies were carried out on children or included segmental vitiligo. No trials evaluating micropigmentation, melanocyte transplantation, depigmentation or cosmetic camouflage could be found. Despite the fact that the main impact of vitiligo is psychosocial only one study on psychological therapy was found and it is awaiting assessment. AUTHORS' CONCLUSIONS: This review has found some evidence to support existing therapies for vitiligo, but the different designs and outcome measurements, lack of quality of life measures and adverse effect reporting in the studies limit the usefulness of their findings. There is a pressing need for high quality randomised trials using standardised measures of repigmentation and which address relevant clinical outcomes including quality of life.


Asunto(s)
Vitíligo , Humanos , Terapia PUVA/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Esteroides/administración & dosificación , Vitíligo/tratamiento farmacológico , Vitíligo/cirugía
12.
J Biol Chem ; 273(32): 19993-20000, 1998 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-9685336

RESUMEN

We have previously demonstrated cleavage of alpha-spectrin by caspase-3 and calpain during apoptosis in SH-SY5Y neuroblastoma cells (Nath, R., Raser, K. J., Stafford, D., Hajimohammadreza, I., Posner, A., Allen, H., Talanian, R. V., Yuen, P., Gilbertsen, R. B., and Wang, K. K. (1996) Biochem. J. 319, 683-690). We demonstrate here that calcium/calmodulin-dependent protein kinase IV (CaMK IV) is cleaved during apoptosis by caspase-3 and calpain. We challenged SH-SY5Y cells with the pro-apoptotic agent thapsigargin. Western blot analysis revealed major CaMK IV breakdown products of 40, 38, and 33 kDa. Digestion of control SH-SY5Y lysate with purified caspase-3 produced a 38-kDa CaMK IV fragment; digestion with purified calpain produced a major fragment of 40 kDa. Pretreatment with carbobenzoxy-Asp-CH2OC(O)-2,6-dichlorobenzene or Z-Val-Ala-Asp-fluoromethylketone was able to block the caspase-3-mediated production of the 38-kDa fragment both in situ and in vitro. Calpain inhibitor II similarly blocked formation of the calpain-mediated 40-kDa fragment both in situ and in vitro. Digestion of recombinant CaMK IV by other caspase family members revealed that only caspase-3 produces a fragmentation pattern consistent to that seen in situ. The major caspase-3 and calpain cleavage sites are respectively identified as PAPD176*A and CG201*A, both within the CaMK IV catalytic domain. Furthermore, calmodulin-stimulated protein kinase activity decreases within 6 h in thapsigargin-treated SH-SY5Y. The loss of activity precedes cell death.


Asunto(s)
Apoptosis/efectos de los fármacos , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Caspasas , Cisteína Endopeptidasas/metabolismo , Neuroblastoma/enzimología , Clorometilcetonas de Aminoácidos/farmacología , Animales , Ácido Aspártico/análogos & derivados , Ácido Aspártico/farmacología , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina , Calpaína/metabolismo , Caspasa 3 , Clorobenzoatos/farmacología , Inhibidores Enzimáticos , Humanos , Ratones , Fragmentos de Péptidos/química , Proteínas Recombinantes/metabolismo , Estaurosporina/farmacología , Tapsigargina/farmacología , Células Tumorales Cultivadas
13.
Inorg Chem ; 39(9): 1874-7, 2000 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-11428106

RESUMEN

The synthesis and single-crystal structure of a new one-to-one charge-transfer salt, derived from decamethylferrocene and 2,3-dicyano-1,4-naphthoquinone, are described. [Fe(Cp*)2][DCNQ] crystallizes in the orthorhombic space group Pbca, with a = 17.3149(5) A, b = 14.6862(4) A, c = 21.0507(6) A, and Z = 8. Magnetization vs temperature data obtained in 100 G suggest that the compound exhibits dominant one-dimensional ferromagnetic coupling and that it subsequently undergoes an antiferromagnetic phase transition below TN approximately 4 K. Results of magnetization vs applied field experiments show that the compound is a metamagnet with a critical field of approximately 3 kG at 1.8 K. In the nominally antiferromagnetic state, apparent canting of the moments gives rise to a small amount of hysteresis. This picture is supported by ac susceptibility data. The 57Fe Mössbauer spectrum exhibits the expected decamethylferrocenium unresolved quadrupole doublet (delta = 0.53 mm/s) at 77 K and magnetic hyperfine splitting, Hint = 37.9 T, corresponding to long-range magnetic order at 1.63 K.

14.
J Biol Chem ; 275(25): 18712-6, 2000 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-10751397

RESUMEN

The full-length, protein coding sequence for dehaloperoxidase was obtained using a reverse genetic approach and a cDNA library from marine worm Amphitrite ornata. The crystal structure of the dehaloperoxidase (DHP) was determined by the multiple isomorphous replacement method and was refined at 1.8-A resolution. The enzyme fold is that of the globin family and, together with the amino acid sequence information, indicates that the enzyme evolved from an ancient oxygen carrier. The peroxidase activity of DHP arose mainly through changes in the positions of the proximal and distal histidines relative to those seen in globins. The structure of a complex of DHP with 4-iodophenol is also reported, and it shows that in contrast to larger heme peroxidases DHP binds organic substrates in the distal cavity. The binding is facilitated by the histidine swinging in and out of the cavity. The modeled position of the oxygen atom bound to the heme suggests that the enzymatic reaction proceeds via direct attack of the oxygen atom on the carbon atom bound to the halogen atom.


Asunto(s)
Peroxidasas/química , Poliquetos/enzimología , Secuencia de Aminoácidos , Animales , Clonación Molecular , Cristalografía por Rayos X , Hemoglobinas , Datos de Secuencia Molecular , Peroxidasas/genética , Conformación Proteica , Homología de Secuencia de Aminoácido
15.
J Biol Chem ; 273(35): 22490-7, 1998 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-9712874

RESUMEN

The degradation of alphaII- and betaII-spectrin during apoptosis in cultured human neuroblastoma SH-SY5Y cells was investigated. Immunofluorescent staining showed that the collapse of the cortical spectrin cytoskeleton is an early event following staurosporine challenge. This collapse correlated with the generation of a series of prominent spectrin breakdown products (BDPs) derived from both alphaII- and betaII-subunits. Major C-terminal alphaII-spectrin BDPs were detected at approximately 150, 145, and 120 kDa (alphaII-BDP150, alphaII-BDP145, and alphaII-BDP120, respectively); major C-terminal betaII-spectrin BDPs were at approximately 110 and 85 kDa (betaII-BDP110 and betaII-BDP85, respectively). N-terminal sequencing of the major fragments produced in vitro by caspase 3 revealed that alphaII-BDP150 and alphaII-BDP120 were generated by cleavages at DETD1185*S1186 and DSLD1478*S1479, respectively. For betaII-spectrin, a major caspase site was detected at DEVD1457*S1458, and both betaII-BDP110 and betaII-BDP85 shared a common N-terminal sequence starting with Ser1458. An additional cleavage site near the C terminus, at ETVD2146*S2147, was found to account for betaII-BDP85. Studies using specific caspase or calpain inhibitors indicate that the pattern of spectrin breakdown during apoptosis differs from that during non-apoptotic cell death. We postulate that in concert with calpain, caspase rapidly targets critical sites in both alphaII- and betaII-spectrin and thereby initiates a rapid dissolution of the spectrin-actin cortical cytoskeleton with apoptosis.


Asunto(s)
Apoptosis , Caspasas , Cisteína Endopeptidasas/metabolismo , Espectrina/metabolismo , Secuencia de Aminoácidos , Caspasa 3 , Humanos , Hidrólisis , Cinética , Espectrina/química , Especificidad por Sustrato , Células Tumorales Cultivadas
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