RESUMO
We evaluated myoblast implantation in 10 boys with Duchenne muscular dystrophy (DMD) and absent dystrophin (age 5-10 years) who were implanted with 100 million myoblasts in the anterior tibial muscle of one leg and placebo in the other. Cyclosporine (5 mg/kg/day) was administered for 7 months. Pre- and postimplantation (after 1 and 6 months) muscle biopsies were analyzed. Force generation (tetanic tension and maximum voluntary contraction) was measured monthly in a double-blind design. There was increased force generation in both legs of all boys, probably due to cyclosporine. Using the polymerase chain reaction, evidence of myoblast survival and dystrophin mRNA expression was obtained in 3 patients after 1 month and in 1 patient after 6 months. These studies suggest a salutary effect of cyclosporine upon muscular force generation in Duchenne muscular dystrophy; however, myoblast implantation was not effective in replacing clinically significant amounts of dystrophin in DMD muscle.
Assuntos
Distrofina/deficiência , Músculo Esquelético/transplante , Distrofias Musculares/fisiopatologia , Distrofias Musculares/terapia , Adulto , Biópsia , Transplante de Células/métodos , Células Cultivadas , Criança , Pré-Escolar , Ciclosporina/uso terapêutico , Distrofina/biossíntese , Teste de Histocompatibilidade , Humanos , Imunossupressores/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Contração Muscular , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Distrofias Musculares/patologia , Exame Físico , Biossíntese de Proteínas , Doadores de Tecidos , Transcrição GênicaRESUMO
Gene delivery by transplantation of normal myoblasts has been proposed as a treatment of the primary defect, lack of the muscle protein dystrophin, that causes Duchenne muscular dystrophy (DMD), a lethal human muscle degenerative disorder. To test this possibility, we transplanted normal myoblasts from a father or an unaffected sibling into the muscle of eight boys with DMD, and assessed their production of dystrophin. Three patients with deletions in the dystrophin gene expressed normal dystrophin transcripts in muscle biopsy specimens taken from the transplant site one month after myoblast injection. Using the polymerase chain reaction we established that the dystrophin in these biopsies derived from donor myoblast DNA. These results show that transplanted myoblasts persist and produce dystrophin in muscle fibres of DMD patients.
Assuntos
Distrofina/genética , Músculos/transplante , Distrofias Musculares/genética , Distrofias Musculares/cirurgia , Transcrição Gênica , Adulto , Sequência de Bases , Criança , Éxons , Antígenos HLA/genética , Teste de Histocompatibilidade , Humanos , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Sondas de Oligonucleotídeos , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
A recombinant gene encoding human growth hormone (hGH) was stably introduced into cultured myoblasts with a retroviral vector. After injection of genetically engineered myoblasts into mouse muscle, hGH could be detected in serum for 3 months. The fate of injected myoblasts was assessed by coinfecting the cells with two retroviral vectors, one encoding hGH and the other encoding beta-galactosidase from Escherichia coli. These results provide evidence that myoblasts, which can fuse into preexisting multinucleated myofibers that are vascularized and innervated, may be advantageous as vehicles for systemic delivery of recombinant proteins.