Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes

Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserve

Hemossiderose pulmonar idiopática tratada com azatioprina: relato de caso em criança Idiopathic pulmonary hemosiderosis treated with azathioprine in a child

A hemossiderose pulmonar idiopática (HPI), principal causa de hemossiderose pulmonar em crianças, cursa com sangramento alveolar intermitente e presença de hemossiderófagos no escarro ou no lavado gástrico. O tratamento é baseado nos corticoesteróides e citostáticos, em condições especiais. Descreve-se o caso de uma menina de sete anos com HPI, que conseguiu controle parcial da doença mediante altas doses de corticoesteróide. O tratamento, no entanto, necessitou ser suspenso gradualmente visto a paciente ter desenvolvido fácies cushingóide. Foi iniciada a associação da azatioprina ao corticóide até a substituição total por azatioprina isolada, cujo uso foi mantido por quatro anos, com ótimo resultado.<br>Idiopathic pulmonary hemosiderosis (IPH), the main cause of pulmonary hemosiderosis in children, is characterized by intermittent alveolar bleeding and hemosiderin-laden macrophages in sputum and in gastric lavage. The treatment is based on corticosteroids and cytotoxic drugs, under special conditions. We describe the case of a 7-year-old girl with IPH who achieved partial clinical remission with high doses of corticosteroids. However, the treatment had to be discontinued because the patient developed Cushing's syndrome. Treatment was started with an azathioprine-corticosteroid combination and then changed to azathioprine alone, which was maintained for four years, with excellent results

MRI Assessment of Cardiomyopathy Induced by β1-Adrenoreceptor Autoantibodies and Protection Through β3-Adrenoreceptor Overexpression

The cardiopathogenic role of autoantibodies (aabs) directed against β1-adrenoreceptors (β1-AR) is well established. In mouse models, they cause progressive dilated cardiomyopathy (DCM) whose characterization with echocardiography requires prolonged protocols with numerous animals, complicating the evaluation of new treatments. Here, we report on the characterization of β1-aabs-induced DCM in mice using 11.7T MRI. C57BL/6J mice (n = 10 per group) were immunized against the β1-AR and left ventricular (LV) systolic function was assessed at 10, 18 and 27 weeks. Increase in LV mass/tibial length ratio was detected as the first modification at 10 weeks together with dilation of cavities, thereby outperforming echocardiography. Significant impairment in diastolic index was also observed in immunized animals before the onset of systolic dysfunction. Morphometric and histological measurements confirmed these observations. The same protocol performed on β3-AR-overexpressing mice and wild-type littermates (n = 8-12 per group) showed that transgenic animals were protected with reduced LV/TL ratio compared to wild-type animals and maintenance of the diastolic index. This study demonstrates that MRI allows a precocious detection of the subtle myocardial dysfunction induced by β1-aabs and that β3-AR stimulation blunts the development of β1-aabs-induced DCM, thereby paving the way for the use of β3AR-stimulating drugs to treat this autoimmune cardiomyopathy