Involvement of X-box binding protein 1 and reactive oxygen species pathways in the pathogenesis of tumour necrosis factor receptor-associated periodic syndrome.
Ann Rheum Dis
; 71(12): 2035-43, 2012 Dec.
Article
en En
| MEDLINE
| ID: mdl-22679299
ABSTRACT
OBJECTIVES:
To investigate convergence of endoplasmic reticulum stress pathways and enhanced reactive oxygen species (ROS) production, due to intracellular retention of mutant tumour necrosis factor receptor 1 (TNFR1), as a disease mechanism in TNFR-associated periodic syndrome (TRAPS).METHODS:
Peripheral blood mononuclear cells from patients with TRAPS (n=16) and healthy controls (HC) (n=22) were studied alongside HEK293T cells expressing wild type-TNFR1 or TRAPS-associated mutations. Unfolded protein response (UPR)-associated proteins (protein kinase-like endoplasmic reticulum kinase, PERK), phosphorylated-PERK (p-PERK), phosphorylated inositol-requiring enzyme 1α (p-IRE1α) and spliced X-box binding protein 1 (sXBP1)) were measured by flow cytometry. XBP1 splicing and UPR-associated transcript expression were assessed by reverse transcription PCR/quantitative real-time PCR. ROS levels were measured using CM-H(2)DCFDA and MitoSOX Red in patients' monocytes or HEK293T cells by flow cytometry.RESULTS:
Mutant TNFR1-expressing HEK293T cells had increased TNFR1 expression associated with intracellular aggregation. TRAPS patients had increased sXBP1 transcripts (p<0.01) compared with HC. Raised p-PERK protein was seen, indicative of an UPR, but other UPR-associated transcripts were normal. Increased ROS levels were observed in TRAPS monocytes compared with HCs (p<0.02); these increased further upon IL-6 stimulation (p<0.01). Lipopolysaccharide-stimulated peripheral blood mononuclear cells of patients with TRAPS, but not HCs, demonstrated increased sXBP1 levels (p<0.01), which were reduced by antioxidant treatment (p<0.05).CONCLUSIONS:
Patients with TRAPS have evidence of increased sXBP1 and PERK expression but without other signs of classical UPR, and also with high ROS generation that may contribute to the pro-inflammatory state associated with TRAPS. The authors propose a non-traditional XBP1 pathway with enhanced sXBP1 as a novel disease-contributing mechanism in TRAPS.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
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Factor de Necrosis Tumoral alfa
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Especies Reactivas de Oxígeno
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Proteínas de Unión al ADN
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Enfermedades Autoinflamatorias Hereditarias
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Estrés del Retículo Endoplásmico
Tipo de estudio:
Etiology_studies
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Risk_factors_studies
Límite:
Adolescent
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Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Ann Rheum Dis
Año:
2012
Tipo del documento:
Article
País de afiliación:
Reino Unido