RESUMO
OBJECTIVE: To observe the cellular expression of (R127W) HSPB1 and its influence on neurofilament light chain (NFL) self-assembly and co-localization with NFL. METHODS: Eukaryotic expression vectors pEGFPN1-(wt) HSPB1 and pEGFPN1- (R127W) HSPB1 were constructed. Hela cells were transiently transfected with pEGFPN1-(wt) HSPB1 or pEGFPN1- (R127W) HSPB1 and observed under a confocal microscope. Hela cells were also transiently co-transfected with Pcl-NFL and pEGFPN1-(wt)HSPB1, or pCL-NFL and pEGFPN1-(R127W)HSPB1. The self-assembly of NFL was observed and the co-localization study of HSPB1/ (R127W)HSPB1 with NFL was carried out in these two cell models by immunofluorescence technique. RESULTS: The aggregates formed by EGFP-(R127W)HSPB1 predominantly located around the nucleus, and EGFP-(wt)HSPB1 showed diffusion pattern in Hela cells. When co expressed with EGFP-(wt)HSPB1, NFL formed homogeneous structure in cytosol. When co-expressed with EGFP-(R127W)HSPB1, however, NFL had amorphous staining pattern predominantly consisting of NFL aggregates, and NFL co-localized with (R127W)HSPB1 in these aggregates. CONCLUSION: The R127W mutant of HSPB1 may have reduced capacity to serve as a chaperone to prevent aggregate formation, and fail to correctly organize the neurofilament network. Dysfunction of the axon cytoskeleton and axon transport may be the primary mechanism of R127W mutation of HSPB1 in the pathogenesis of Charcot-Marie-Tooth disease.
Assuntos
Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas de Neurofilamentos/metabolismo , Sequência de Bases , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/metabolismo , Vetores Genéticos/genética , Células HeLa , Proteínas de Choque Térmico , Humanos , Espaço Intracelular/metabolismo , Chaperonas Moleculares , Ligação Proteica/genética , Transporte Proteico , TransfecçãoRESUMO
The purpose of this study was to understand the mutation features of lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF), ras-associated protein RAB7 (RAB7), lamin A/C (LMNA) and myotubularin-related protein 2 (MTMR2) genes in Chinese Charcot-Marie-Tooth disease (CMT) patients. Mutation analysis of LITAF gene was carried out using PCR combined with DNA sequencing, and mutation analysis of RAB7 gene by PCR-single strand conformation polymorphism (PCR-SSCP) combined with DNA sequencing in 33 CMT patients including 6 probands of autosomal domi-nated CMT families and 27 sporadic patients; mutation analysis of LMNA and MTMR2 genes was observed using PCR-SSCP combined with DNA sequencing in 41 CMT patients, including 14 probands of autosomal recessive CMT fami-lies and 27 sporadic patients. Two sequence variations c.269G-->A and c.274A-->G were detected in LITAF gene and two sequence variations c.1243G-->A and c.1910C-->T were detected in LMNA gene. No sequence variation was found in RAB7 and MTMR2 gene. Variations of c.269G-->A in LITAF gene and c.1243G-->A, c.1910C-->T in LMNA gene are newly found SNPs in this study. Variation of c.274A-->G in LITAF gene is known SNP reported in SNP database. Mutations in LITAF, RAB7, LMNA, and MTMR2 genes are rare in Chinese CMT patients.
Assuntos
Doença de Charcot-Marie-Tooth/genética , Lamina Tipo A/genética , Mutação , Proteínas Nucleares/genética , Proteínas Tirosina Fosfatases não Receptoras/genética , Fatores de Transcrição/genética , Proteínas rab de Ligação ao GTP/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , proteínas de unión al GTP Rab7RESUMO
AIM: To evaluate the safety and efficacy profile of 27-gauge (27G) pars plana vitrectomy (PPV) for the treatment of various vitreoretinal diseases. METHODS: The clinical outcomes of 61 eyes (58 patients) with various vitreoretinal diseases following 27G PPV were retrospectively reviewed. RESULTS: Surgical indications included rhegmatogenous retinal detachment (n=24), full-thickness macular hole (n=12), diabetic retinopathy (n=11), vitreous hemorrhage (n=6), Eales disease (n=4), pathological myopia-related vitreous floater (n=2), and macular epiretinal membrane (n=2). The mean follow-up was 166.4±61.3d (range 98-339d). The mean logMAR best-corrected visual acuity (BCVA) improved from 1.7±1.1 [0.02 decimal visual acuity (VA) equivalent] preoperatively to 1.2±1.0 (0.06 decimal VA equivalent) at the last postoperative visit (P<0.001). The mean operative time was 49.9min. With the exception of complicated cataract in one eye, no intraoperative complications were encountered. No case required conversion to conventional 20-, 23- or 25G instrumentation in all surgical maneuvers except for silicone oil infusion, which required a 25G oil injection syringe. Postoperative complications included transient ocular hypertension, vitreous hemorrhage, persistent intraocular pressure elevation, subconjunctival oil leakage, and recurrent retinal detachment. No cases of hypotony, endophthalmitis, and sclerotomy-related tears were observed. CONCLUSION: The current results suggest that 27G PPV system is a safe and effective treatment for various vitreoretinal diseases. When learning to perform 27G PPV, surgeons may encounter a learning curve and should gradually expand surgical indications from easy to pathologically complicated cases.