RESUMEN
Various systemic or primary glomerular diseases can result in deposition of fibrillary material in the glomerular tuft and may cause an important diagnostic challenge for the pathologists. Biopsy findings of a patient with type 2 diabetes is presented here in which striking fibrillary structures were identified in the mesangium by ultrastructural examination. The distinction between diabetic fibrillosis and fibrillary glomerulonephritis accompanying diabetic nephropathy is discussed in the setting of a literature review.
Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/patología , Mesangio Glomerular/patología , Femenino , Humanos , Persona de Mediana EdadAsunto(s)
Calcio/sangre , Enema/métodos , Impactación Fecal/tratamiento farmacológico , Pacientes Internos , Fosfatos/sangre , Administración Rectal , Anciano , Anciano de 80 o más Años , Impactación Fecal/sangre , Impactación Fecal/complicaciones , Femenino , Tasa de Filtración Glomerular , Humanos , Hiperfosfatemia/sangre , Hiperfosfatemia/inducido químicamente , Hiperfosfatemia/epidemiología , Hipocalcemia/sangre , Hipocalcemia/inducido químicamente , Hipocalcemia/epidemiología , Incidencia , Masculino , Fosfatos/administración & dosificación , Insuficiencia Renal/sangre , Insuficiencia Renal/complicaciones , Insuficiencia Renal/fisiopatología , Factores de Riesgo , Singapur/epidemiologíaRESUMEN
Mutations in ATCAY that encodes the brain-specific protein BNIP-H (or Caytaxin) lead to Cayman cerebellar ataxia. BNIP-H binds to glutaminase, a neurotransmitter-producing enzyme, and affects its activity and intracellular localization. Here we describe the identification and characterization of the binding between BNIP-H and Pin1, a peptidyl-prolyl cis/trans isomerase. BNIP-H interacted with Pin1 after nerve growth factor-stimulation and they co-localized in the neurites and cytosol of differentiating pheochromocytoma PC12 cells and the embryonic carcinoma P19 cells. Deletional mutagenesis revealed two cryptic binding sites within the C-terminus of BNIP-H such that single point mutants affecting the WW domain of Pin1 completely abolished their binding. Although these two sites do not contain any of the canonical Pin1-binding motifs they showed differential binding profiles to Pin1 WW domain mutants S16E, S16A and W34A, and the catalytically inert C113A of its isomerase domain. Furthermore, their direct interaction would occur only upon disrupting the ability of BNIP-H to form an intramolecular interaction by two similar regions. Furthermore, expression of Pin1 disrupted the BNIP-H/glutaminase complex formation in PC12 cells under nerve growth factor-stimulation. These results indicate that nerve growth factor may stimulate the interaction of BNIP-H with Pin1 by releasing its intramolecular inhibition. Such a mechanism could provide a post-translational regulation on the cellular activity of BNIP-H during neuronal differentiation.