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1.
Dermatol Ther ; 34(6): e15139, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34549487

RESUMO

Debulking followed by intralesional 5-fluorouracil (deb-IL5FU) is a nonsurgical modality which has been used to treat skin cancer anecdotally for many years. There are few in depth studies examining this technique and success rate of intralesional 5-fluorouracil (IL5FU) for the treatment of cutaneous squamous cell carcinoma (cSCC). To evaluate the response rate of deb-IL5FU for the treatment of cSCC and to determine which patient factors were associated with tumor clearance or treatment failure. A retrospective chart analysis of patients with the diagnosis of cSCC or keratoacanthoma (KA) and subsequent deb-IL5FU treatment. Sixty-one patients with a total of 315 tumors (cSCC and KA), were treated using deb-IL5FU. The overall tumor clearance rate was 89%. This was highest for well-differentiated SCC, SCC, KA-type SCC, and KA. Tumors on the trunk and extremities showed high clearance rates while tumors on the scalp/face/neck/ears showed lower clearance rates. Immunocompetent patients cleared more tumors compared to immunocompromised patients. Limitations included the retrospective nature of this analysis as well as a small sample size. Treatment of cSCC and KA with deb-IL5FU demonstrated high tumor clearance rates. Lower rates of clearance were seen in males, immunosuppressed patients, tumors located on the scalp and face/neck/ears.


Assuntos
Carcinoma de Células Escamosas , Ceratoacantoma , Neoplasias Cutâneas , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/tratamento farmacológico , Procedimentos Cirúrgicos de Citorredução , Fluoruracila , Humanos , Ceratoacantoma/diagnóstico , Ceratoacantoma/tratamento farmacológico , Ceratoacantoma/patologia , Masculino , Estudos Retrospectivos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/tratamento farmacológico
2.
Dermatol Online J ; 26(4)2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32621681

RESUMO

Sézary syndrome is a rare leukemic subtype of cutaneous T cell lymphoma that is characterized by erythroderma, lymphadenopathy, and malignant T cells in the peripheral blood. Poor prognostic factors of Sézary syndrome include advanced disease stage, older age at onset, and large cell transformation. Presentation with bullous lesions, though rare, has been reported in a few patients. We present an elderly woman with bullous Sézary syndrome who presented with a two-month history of progressive rash. Upon admission, the patient had pruritic, erythematous, edematous plaques with overlying flaccid bullae and erosions involving the scalp, neck, torso, and extremities. Despite treatment, the patient died two months after presentation. Although rare, bullous lesions associated with Sézary syndrome may indicate poor prognosis.


Assuntos
Síndrome de Sézary/complicações , Dermatopatias Vesiculobolhosas/etiologia , Neoplasias Cutâneas/complicações , Idoso , Diagnóstico Diferencial , Evolução Fatal , Feminino , Humanos , Prognóstico , Síndrome de Sézary/diagnóstico , Síndrome de Sézary/patologia , Dermatopatias Vesiculobolhosas/patologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia
3.
Transpl Infect Dis ; 20(3): e12869, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29512247

RESUMO

A 61-year-old Caucasian man presented with papules on his left forearm and hand three months after liver transplantation: images from physical exam, pathology, and microbiology are presented. Skin biopsy confirmed the presence of fungal elements within the hair shaft, which is consistent with Majocchi granuloma, also known as nodular granulomatous perifolliculitis. A combination of fungal culture, microscopic morphology, and gene sequencing was used to identify the causative organism. The patient recovered with appropriate systemic antifungal therapy.


Assuntos
Eritema/microbiologia , Antebraço/patologia , Transplante de Fígado/efeitos adversos , Tinha/diagnóstico , Antifúngicos/uso terapêutico , Biópsia , Antebraço/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNA , Pele/microbiologia , Pele/patologia , Tinha/tratamento farmacológico , Tinha/microbiologia , Trichophyton/efeitos dos fármacos , Trichophyton/genética , Trichophyton/isolamento & purificação , Trichophyton/ultraestrutura
4.
J Biol Chem ; 288(13): 9447-56, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23404504

RESUMO

The pemphigus family of autoimmune bullous disorders is characterized by autoantibody binding to desmoglein 1 and/or 3 (dsg1/dsg3). In this study we show that EGF receptor (EGFR) is activated following pemphigus vulgaris (PV) IgG treatment of primary human keratinocytes and that EGFR activation is downstream of p38 mitogen-activated protein kinase (p38). Inhibition of EGFR blocked PV IgG-triggered dsg3 endocytosis, keratin intermediate filament retraction, and loss of cell-cell adhesion in vitro. Significantly, inhibiting EGFR prevented PV IgG-induced blister formation in the passive transfer mouse model of pemphigus. These data demonstrate cross-talk between dsg3 and EGFR, that this cross-talk is regulated by p38, and that EGFR is a potential therapeutic target for pemphigus. Small-molecule inhibitors and monoclonal antibodies directed against EGFR are currently used to treat several types of solid tumors. This study provides the experimental rationale for investigating the use of EGFR inhibitors in pemphigus.


Assuntos
Acantólise/metabolismo , Receptores ErbB/metabolismo , Regulação da Expressão Gênica , Imunoglobulina G/metabolismo , Pênfigo/metabolismo , Animais , Animais Recém-Nascidos , Adesão Celular , Células Cultivadas , Desmogleínas/metabolismo , Desmossomos/metabolismo , Detergentes/farmacologia , Modelos Animais de Doenças , Feminino , Humanos , Imunoglobulina G/química , Queratinócitos/citologia , Queratinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
J Skin Cancer ; 2023: 9990046, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36777100

RESUMO

Background: Patients with field cancerization will develop numerous superficial non-melanoma skin cancers (NMSCs). Treating patients with field cancerization can be challenging and burdensome due to the numerous non-melanoma skin cancers (NMSCs) they develop and the frequent dermatology visits required for biopsy and treatment. Objective: The success rate of diagnosing and treating lesions suspicious for NMSCs on the same day is measured, immediately after biopsy. Methods: We retrospectively reviewed records of patients with same day lesion diagnosis and curettage treatment to determine diagnostic accuracy, treatment failure, and number needed to treat to reduce a follow-up treatment. Results: A total of 237 lesions underwent same day biopsy and treatment, of which the majority were NMSC (66%) or actinic keratosis (23%). Patients had at least 3 months and a median of 17 months follow-up. A total of 20 lesions either recurred or were deemed to require additional treatment. The number needed to treat (NNT) to prevent one follow-up treatment was 1.3. Limitations: sample size limited ability to determine risk factors for treatment failure. Conclusion: Simultaneous diagnosis and treatment of superficial NMSCs is a successful way of improving efficiency and patient satisfaction.

7.
J Biol Chem ; 285(12): 8936-41, 2010 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-20093368

RESUMO

Pemphigus vulgaris (PV) is an autoimmune blistering disease in which antibodies against the desmosomal cadherin, DSG3 (desmoglein-3), cause acantholysis. It has become increasingly clear that loss of cell-cell adhesion in PV is a complex and active process involving multiple signaling events such as activation of p38MAPK. It has also been demonstrated that incubating keratinocytes with PV IgG causes a redistribution of DSG3 from the cell surface to endosomes, which target these proteins for degradation. This study was undertaken to determine the relationship between p38MAPK and DSG3 endocytosis in pemphigus. In this work, we confirm that PV IgG causes internalization of cell-surface DSG3 into endosomes (as early as 4 h), which are then depleted from both detergent-soluble and detergent-insoluble pools. Cell-surface DSG3 internalization and depletion from both the detergent-soluble and detergent-insoluble fractions were blocked by the p38MAPK inhibitor SB202190. These data suggest that p38MAPK is capable of regulating PV IgG-mediated DSG3 internalization and that previously isolated mechanistic observations may be linked to a common pathway by which pemphigus autoantibodies lead to acantholysis.


Assuntos
Desmogleína 3/metabolismo , Regulação Enzimológica da Expressão Gênica , Pênfigo/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Autoanticorpos/química , Biotinilação , Membrana Celular/metabolismo , Detergentes/farmacologia , Endocitose , Endossomos/metabolismo , Humanos , Imunoglobulina G/química , Queratinócitos/citologia , Microscopia Confocal/métodos , Transdução de Sinais
8.
J Exp Med ; 199(7): 959-70, 2004 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-15067032

RESUMO

Mast cells secrete various substances that initiate and perpetuate allergic responses. Cross-linking of the high-affinity receptor for IgE (FcepsilonRI) in RBL-2H3 and bone marrow-derived mast cells activates sphingosine kinase (SphK), which leads to generation and secretion of the potent sphingolipid mediator, sphingosine-1-phosphate (S1P). In turn, S1P activates its receptors S1P1 and S1P2 that are present in mast cells. Moreover, inhibition of SphK blocks FcepsilonRI-mediated internalization of these receptors and markedly reduces degranulation and chemotaxis. Although transactivation of S1P1 and Gi signaling are important for cytoskeletal rearrangements and migration of mast cells toward antigen, they are dispensable for FcepsilonRI-triggered degranulation. However, S1P2, whose expression is up-regulated by FcepsilonRI cross-linking, was required for degranulation and inhibited migration toward antigen. Together, our results suggest that activation of SphKs and consequently S1PRs by FcepsilonRI triggering plays a crucial role in mast cell functions and might be involved in the movement of mast cells to sites of inflammation.


Assuntos
Mastócitos/imunologia , Receptores Acoplados a Proteínas G/genética , Receptores de IgE/metabolismo , Animais , Sequência de Bases , Degranulação Celular , Linhagem Celular , Quimiotaxia , Lisofosfolipídeos/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Interferente Pequeno/genética , Receptores de Lisofosfolipídeos , Esfingosina/análogos & derivados , Esfingosina/biossíntese , Ativação Transcricional
9.
Mol Cell Biol ; 25(10): 4237-49, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15870293

RESUMO

Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, is the ligand for five specific G protein-coupled receptors, named S1P(1) to S1P(5). In this study, we found that cross-communication between platelet-derived growth factor receptor and S1P(2) serves as a negative damper of PDGF functions. Deletion of the S1P(2) receptor dramatically increased migration of mouse embryonic fibroblasts toward S1P, serum, and PDGF but not fibronectin. This enhanced migration was dependent on expression of S1P(1) and sphingosine kinase 1 (SphK1), the enzyme that produces S1P, as revealed by downregulation of their expression with antisense RNA and small interfering RNA, respectively. Although S1P(2) deletion had no significant effect on tyrosine phosphorylation of the PDGF receptors or activation of extracellular signal-regulated kinase 1/2 or Akt induced by PDGF, it reduced sustained PDGF-dependent p38 phosphorylation and markedly enhanced Rac activation. Surprisingly, S1P(2)-null cells not only exhibited enhanced proliferation but also markedly increased SphK1 expression and activity. Conversely, reintroduction of S1P(2) reduced DNA synthesis and expression of SphK1. Thus, S1P(2) serves as a negative regulator of PDGF-induced migration and proliferation as well as SphK1 expression. Our results suggest that a complex interplay between PDGFR and S1P receptors determines their functions.


Assuntos
Movimento Celular/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/farmacologia , Receptores de Lisoesfingolipídeo/metabolismo , Animais , Estruturas da Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quimiotaxia/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/enzimologia , Fibroblastos/metabolismo , Deleção de Genes , Expressão Gênica , Masculino , Camundongos , Modelos Biológicos , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Receptores de Lisoesfingolipídeo/deficiência , Receptores de Lisoesfingolipídeo/genética , Proteínas rac de Ligação ao GTP/metabolismo
10.
Transplant Proc ; 49(1): 213-215, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28104140

RESUMO

Renal transplant recipients are at an increased risk of developing verrucae due to chronic immunosuppression, and certain therapies may confer a greater risk. Herein, we describe a 51-year-old woman with a 10-year-old unrelated kidney transplant who developed numerous therapy-resistant verrucae while on mycophenolate mofetil and tacrolimus maintenance immunosuppression. Over several years of immunosuppressant therapy, she declined the approach of reducing her mycophenolate mofetil dose to potentially improve her verrucae. Unfortunately, she later developed graft rejection requiring reversion to peritoneal dialysis. Within months of reducing her mycophenolate mofetil dose (her tacrolimus dose remained unchanged), she experienced dramatic resolution of many of her verrucae. In the current case, the observed clinical improvement may have resulted from either the total reduction of immunosuppression or the specific reduction of mycophenolate mofetil. Consequently, mycophenolate mofetil may contribute to the refractory nature of verrucae within renal transplant recipients, and further research should determine the relationship between verrucae development and both specific immunosuppressant therapies and the degree of immunosuppression.


Assuntos
Imunossupressores/efeitos adversos , Transplante de Rim/efeitos adversos , Ácido Micofenólico/efeitos adversos , Complicações Pós-Operatórias/induzido quimicamente , Verrugas/induzido quimicamente , Feminino , Rejeição de Enxerto/induzido quimicamente , Humanos , Terapia de Imunossupressão/efeitos adversos , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Pessoa de Meia-Idade , Ácido Micofenólico/administração & dosagem , Tacrolimo/administração & dosagem , Tacrolimo/efeitos adversos
11.
J Clin Aesthet Dermatol ; 10(9): 36-38, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29344326

RESUMO

Pyoderma gangrenosum and hidradenitis suppurativa are skin conditions characterized by an intense neutrophil-mediated inflammatory response that is often difficult to effectively treat. Successful use of interleukin (IL)-1ß inhibition using canakinumab and anakinra has been reported in patients with concomitant pyoderma gangrenosum and hidradenitis suppurativa. We report two cases where targeted therapy with canakinumab failed to lead to improvement for patients with pyoderma gangrenosum and hidradenitis suppurativa. The reason behind the non-response to IL-1ß blockade seen in these patients is unclear. Our report suggests that further controlled studies are warranted to help clinicians predict treatment responses to anti-IL-1 therapies in these challenging patients.

12.
Oncogene ; 24(1): 178-87, 2005 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-15637591

RESUMO

While most of the pharmacological therapies for melanoma utilize the apoptotic machinery of the cells, the available therapeutic options are limited due to the ability of melanoma cells to resist programmed cell death. Human melanoma cell lines A-375 and M186 are sensitive to ceramide- and Fas-induced cell death, while Mel-2a and M221 are resistant. We have now found that Mel-2a and M221 cells have a significantly higher ceramide/sphingosine-1-phosphate (S1P) ratio than A-375 and M186 cells. As sphingosine kinase (SphK) type 1 plays a critical role in determining the dynamic balance between the proapoptotic sphingolipid metabolite ceramide and the prosurvival S1P, we examined its role in apoptosis of melanoma cells. Increasing SphK1 expression reduced the sensitivity of A-375 melanoma cells to Fas- and ceramide-mediated apoptosis. Conversely, downregulation of SphK1 with small interfering RNA decreased the resistance of Mel-2a cells to apoptosis. Importantly, overexpression of the prosurvival protein Bcl-2 in A-375 cells markedly stimulated SphK1 expression and activity, while downregulation of Bcl-2 reduced SphK1 expression. This link between Bcl-2 and SphK1 might be an additional clue to chemotherapy resistance of malignant melanoma.


Assuntos
Apoptose/fisiologia , Ceramidas/metabolismo , Melanoma/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Regulação para Baixo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Células Tumorais Cultivadas
14.
Cutis ; 97(3): 212-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27023083

RESUMO

Acute generalized exanthematous pustulosis (AGEP) is a rare cutaneous eruption that often is a reaction to medications, most commonly antibiotics. Clinically, AGEP closely mimics pustular psoriasis and also is similar to subcorneal pustular dermatosis and IgA pemphigus. For clinicians, it is important to differentiate AGEP from pustular psoriasis. Acute generalized exanthematous pustulosis will have an acute drug association. Few cases have been known to be caused by hydroxychloroquine (HCQ). Proper therapeutic management of AGEP includes withdrawal of the offending agent, and resolution typically occurs within 15 days. We report a case of AGEP after HCQ administration that did not follow the usual course of resolution after medication cessation. The patient continued to experience cutaneous eruptions that waxed and waned for 81 days. Hydroxychloroquine has a particularly long half-life and is a known cause of AGEP; therefore, it is possible that HCQ-induced AGEP may not follow the typical rapid recovery time.


Assuntos
Pustulose Exantematosa Aguda Generalizada/etiologia , Antirreumáticos/efeitos adversos , Hidroxicloroquina/efeitos adversos , Pustulose Exantematosa Aguda Generalizada/diagnóstico , Pustulose Exantematosa Aguda Generalizada/patologia , Antirreumáticos/administração & dosagem , Antirreumáticos/farmacocinética , Feminino , Meia-Vida , Humanos , Hidroxicloroquina/administração & dosagem , Hidroxicloroquina/farmacocinética , Pessoa de Meia-Idade , Fatores de Tempo
15.
Mol Immunol ; 38(16-18): 1239-45, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12217390

RESUMO

Asthma is a complex condition in which exposure to environmental antigens induces inflammatory reactions in the airway characterized by activation of mast cells and eosinophils. Mast cells are known to be the main effector cells in eliciting IgE-mediated allergic response. These cells secrete various substances that perpetuate inflammation and provoke airway smooth muscle (ASM) contraction. A newly recognized addition to the repertoire of FcepsilonRI-mediated signaling events is the activation of sphingosine kinase leading to the generation of the potent sphingolipid mediator, sphingosine-1-phosphate (S1P) from sphingosine. S1P secretion by the lung significantly increases after challenge with an allergen, adding this sphingolipid metabolite to the variety of mediators that are released during an allergic reaction [FASEB J. 15 (2001) 1212]. Indeed, similar to previous reports, we found that FcepsilonRI cross-linking not only increased cellular levels of S1P, it also markedly enhanced its secretion from rat basophilic leukemia RBL-2H3 cells. Moreover, S1P induced degranulation of RBL and bone marrow derived mast cells (BMMCs) cells as determined by hexosaminidase release. Treatment of BMMCs with the sphingosine kinase inhibitors, DL-threo-dihydrosphingosine and dimethylsphingosine, reduced IgE/Ag stimulated histamine release. RT-PCR analysis demonstrated that these mast cells express S1P receptors EDG-1 and EDG-5 but not EDG-3, EDG-6 or EDG-8 transcripts. Further studies are needed to determine whether IgE triggering results in transactivation of EDG-1 or EDG-5 present on mast cells and whether this is a critical event for mast cell activation.


Assuntos
Asma/imunologia , Lisofosfolipídeos , Mastócitos/imunologia , Esfingosina/análogos & derivados , Esfingosina/fisiologia , Obstrução das Vias Respiratórias/imunologia , Animais , Asma/fisiopatologia , Inflamação/imunologia , Pulmão/citologia , Pulmão/fisiopatologia , Modelos Imunológicos , Músculo Liso/fisiopatologia , Ratos , Receptores de IgE/metabolismo , Transdução de Sinais , Esfingolipídeos/metabolismo
16.
Int J Dermatol ; 54(3): 370-4, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25039741

RESUMO

BACKGROUND: Vismodegib is a novel hedgehog pathway inhibitor approved to treat advanced and metastatic basal cell carcinoma (BCC) in the United States. Several studies have demonstrated efficacy for treatment of new and existing BCC in both basal cell nevus syndrome (BCNS) and non-BCNS patients. However, severe and numerous adverse events are associated with vismodegib use. Therefore, we have also examined all of the currently published clinical trials and tabulated the available adverse events for review. The most frequently reported adverse events include muscle spasms (53.4%), dysgeusia/ageusia (49.3%), alopecia (38.8%), fatigue (32.0%), nausea (28.4%), weight loss (24.2%), and decreased appetite (16.5%). CASE STUDY: We report a case of a previously healthy 72-year-old male with a history of innumerable BCCs who developed severe nausea, jaundice, and cholestasis with significantly elevated BUN, creatinine, and liver enzymes one month after starting vismodegib. The patient began using over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) to treat severe, vismodegib-induced myalgia. No other new medications were started. Our patient had no history of liver disease. CONCLUSIONS: Herein, we describe a potential serious adverse effect associated with vismodegib use. Whether the illness is directly attributable to the medication or the result of drug-drug interactions between vismodegib and NSAIDs, practitioners should be aware of the possibility of hepatic injury in patients on vismodegib. Furthermore, patients need to be informed of the potential risks of vismodegib and should be monitored closely to ensure that life-threatening complications of treatment are avoided.


Assuntos
Anilidas/efeitos adversos , Anti-Inflamatórios não Esteroides/efeitos adversos , Antineoplásicos/efeitos adversos , Carcinoma Basocelular/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Colestase/induzido quimicamente , Piridinas/efeitos adversos , Neoplasias Cutâneas/tratamento farmacológico , Idoso , Aspirina/efeitos adversos , Interações Medicamentosas , Disgeusia/induzido quimicamente , Humanos , Masculino , Mialgia/induzido quimicamente , Mialgia/tratamento farmacológico , Naproxeno/efeitos adversos
19.
Dermatol Res Pract ; 2010: 456841, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20631907

RESUMO

Pemphigus is a group of human autoimmune blistering diseases of the skin in which autoantibodies to desmosome cadherins induce loss of cell-cell adhesion (acantholysis). In addition to steric hindrance and activation of intracellular signaling, apoptosis has been suggested to contribute to the mechanism by which pathogenic IgG induces acantholysis. We review the current literature examining the role of apoptosis in pemphigus. Current data suggest that apoptosis is not required for blister induction, but that activation of proapoptotic proteins, including caspase cysteine proteinases, may sensitize cells to the acantholytic effects of pemphigus IgG.

20.
J Biol Chem ; 284(18): 12524-32, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19270308

RESUMO

In pemphigus vulgaris and pemphigus foliaceus (PF), autoantibodies against desmoglein-3 and desmoglein-1 induce epidermal cell detachment (acantholysis) and blistering. Activation of keratinocyte intracellular signaling pathways is emerging as an important component of pemphigus IgG-mediated acantholysis. We previously reported activation of p38 mitogen-activated protein kinase (MAPK) in response to pathogenic pemphigus vulgaris and PF IgG. Inhibition of p38MAPK blocked pemphigus IgG-induced cytoskeletal reorganization in tissue culture and blistering in pemphigus mouse models. We now extend these observations by demonstrating two peaks of p38MAPK activation in pemphigus tissue culture and mouse models. Administration of the p38MAPK inhibitor SB202190 before PF IgG injection blocked both peaks of p38MAPK phosphorylation and blister formation, consistent with our previous findings; however, administration of the inhibitor 4 h after PF IgG injection blocked only the later peak of p38MAPK activation but failed to block blistering. Examination of the temporal relationship of p38MAPK phosphorylation and apoptosis showed that apoptosis occurs at or after the second peak of p38MAPK activation. The time course of p38MAPK activation and apoptotic markers, as well as the ability of inhibitors of p38MAPK to block activation of the proapoptotic proteinase caspase-3, suggest that activation of apoptosis is downstream to, and a consequence of, p38MAPK activation in pemphigus acantholysis. Furthermore, these observations suggest that the earlier peak of p38MAPK activation is part of the mechanism leading to acantholysis, whereas the later peak of p38MAPK and apoptosis may not be essential for acantholysis.


Assuntos
Acantólise/enzimologia , Pênfigo/enzimologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Acantólise/patologia , Animais , Apoptose/efeitos dos fármacos , Autoanticorpos/metabolismo , Caspase 3/metabolismo , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Desmogleína 1/metabolismo , Desmogleína 3/metabolismo , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Humanos , Imunoglobulina G/metabolismo , Camundongos , Pênfigo/patologia , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Técnicas de Cultura de Tecidos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
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