RESUMO
In Neurofibromatosis 1 (NF1) germ line loss of function mutations result in reduction of cellular neurofibromin content (NF1+/-, NF1 haploinsufficiency). The Ras-GAP neurofibromin is a very large cytoplasmic protein (2818 AA, 319 kDa) involved in the RAS-MAPK pathway. Aside from regulation of proliferation, it is involved in mechanosensoric of cells. We investigated neurofibromin replacement in cultured human fibroblasts showing reduced amount of neurofibromin. Full length neurofibromin was produced recombinantly in insect cells and purified. Protein transduction into cultured fibroblasts was performed employing cell penetrating peptides along with photochemical internalization. This combination of transduction strategies ensures the intracellular uptake and the translocation to the cytoplasm of neurofibromin. The transduced neurofibromin is functional, indicated by functional rescue of reduced mechanosensoric blindness and reduced RasGAP activity in cultured fibroblasts of NF1 patients or normal fibroblasts treated by NF1 siRNA. Our study shows that recombinant neurofibromin is able to revert cellular effects of NF1 haploinsuffiency in vitro, indicating a use of protein transduction into cells as a potential treatment strategy for the monogenic disease NF1.
Assuntos
Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Células Cultivadas , Fibroblastos/metabolismo , Expressão Gênica , Técnicas de Silenciamento de Genes , Inativação Gênica , Genes Reporter , Humanos , Microscopia de Fluorescência , Neurofibromatose 1/genética , Neurofibromatose 1/metabolismo , Neurofibromina 1/química , Fosforilação , Interferência de RNA , Proteínas Recombinantes de Fusão , Transdução GenéticaRESUMO
This paper focusses on Xhosa healers and their pharmacopoeias in Southern Africa. Its preliminary aim is to show that Xhosa healers have incorporated Western pharmaceutical products into their traditional dispensaries. The primary aim of the paper is to explain the trend towards medicinal incorporation in terms of the historical development of health and health care in Xhosa-speaking regions. Finally, it is suggested that Xhosa healers utilise Western medicines for their symbolic value, allowing them to negotiate some of the historical precedents which have had the effect of marginalising their profession.
