RESUMO
The proteinase prostasin is a candidate mediator for aldosterone-driven proteolytic activation of the epithelial sodium channel (ENaC). It was hypothesized that the aldosterone-mineralocorticoid receptor (MR) pathway stimulates prostasin abundance in kidney and urine. Prostasin was measured in plasma and urine from type 2 diabetic patients with resistant hypertension (n = 112) randomized to spironolactone/placebo in a clinical trial. Prostasin protein level was assessed by immunoblotting in (1) human and rat urines with/without nephrotic syndrome, (2) human nephrectomy tissue, (3) urine and kidney from aldosterone synthase-deficient (AS-/-) mice and ANGII- and aldosterone-infused mice, and in (4) kidney from adrenalectomized rats. Serum aldosterone concentration related to prostasin concentration in urine but not in plasma. Plasma prostasin concentration increased significantly after spironolactone compared to control. Urinary prostasin and albumin related directly and were reduced by spironolactone. In patients with nephrotic syndrome, urinary prostasin protein was elevated compared to controls. In rat nephrosis, proteinuria coincided with increased urinary prostasin, unchanged kidney tissue prostasin, and decreased plasma prostasin while plasma aldosterone was suppressed. Prostasin protein abundance in human nephrectomy tissue was similar across gender and ANGII inhibition regimens. Prostasin urine abundance was not different in AS-/- and aldosterone-infused mice. Prostasin kidney level was not different from control in adrenalectomized rats and AS-/- mice. We found no evidence for a direct relationship between mineralocorticoid receptor signaling and kidney and urine prostasin abundance. The reduction of urinary prostasin in spironolactone-treated patients is most likely the result of an improved glomerular filtration barrier function and generally reduced proteinuria.
Assuntos
Albuminúria/urina , Aldosterona/sangue , Anti-Hipertensivos/farmacologia , Serina Endopeptidases/urina , Espironolactona/farmacologia , Adulto , Idoso , Albuminúria/sangue , Albuminúria/etiologia , Animais , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/uso terapêutico , Nefropatias Diabéticas/complicações , Feminino , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Ratos , Ratos Sprague-Dawley , Serina Endopeptidases/sangue , Serina Endopeptidases/metabolismo , Espironolactona/efeitos adversos , Espironolactona/uso terapêuticoRESUMO
On the basis of previous observations that deletion of the von Hippel-Lindau protein (pVHL) in juxtaglomerular (JG) cells of the kidney suppresses renin and induces erythropoietin expression, this study aimed to characterize the events underlying this striking change of hormone expression. We found that renin cell-specific deletion of pVHL in mice leads to a phenotype switch in JG cells, from a cuboid and multiple vesicle-containing form into a flat and elongated form without vesicles. This shift of cell phenotype was accompanied by the disappearance of marker proteins for renin cells (e.g., aldo-keto reductase family 1, member 7 and connexin 40) and by the appearance of markers of fibroblast-like cells (e.g., collagen I, ecto-5'-nucleotidase, and PDGF receptor-ß). Furthermore, hypoxia-inducible transcription factor-2α (HIF-2α) protein constitutively accumulated in these transformed cells. Codeletion of pVHL and HIF-2α in JG cells completely prevented the phenotypic changes. Similar to renin expression in normal JG cells, angiotensin II negatively regulated erythropoietin expression in the transformed cells. In summary, chronic activation of HIF-2 in renal JG cells leads to a reprogramming of the cells into fibroblast-like cells resembling native erythropoietin-producing cells located in the tubulointerstitium.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Eritropoetina/sangue , Sistema Justaglomerular/patologia , Renina/sangue , Doença de von Hippel-Lindau/patologia , 5'-Nucleotidase/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Biomarcadores/metabolismo , Colágeno Tipo I/metabolismo , Fibroblastos/metabolismo , Sistema Justaglomerular/metabolismo , Masculino , Camundongos , Camundongos Knockout , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Renina/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Doença de von Hippel-Lindau/sangueRESUMO
States of low perfusion pressure of the kidney associate with hyperplasia or expansion of renin-producing cells, but it is unknown whether hypoxia-triggered genes contribute to these changes. Here, we stabilized hypoxia-inducible transcription factors (HIFs) in mice by conditionally deleting their negative regulator, Vhl, using the Cre/loxP system with renin-1d promoter-driven Cre expression. Vhl (−/−(REN)) mice were viable and had normal BP. Deletion of Vhl resulted in constitutive accumulation of HIF-2α in afferent arterioles and glomerular cells and HIF-1α in collecting duct cells of the adult kidney. The preglomerular vascular tree developed normally, but far fewer renin-expressing cells were present, with more than 70% of glomeruli not containing renin cells at the typical juxtaglomerular position. Moreover, these mice had an attenuated expansion of renin-producing cells in response to a low-salt diet combined with an ACE inhibitor. However, renin-producing cells of Vhl (−/−(REN)) mice expressed the erythropoietin gene, and they were markedly polycythemic. Taken together, these results suggest that hypoxia-inducible genes, regulated by VHL, are essential for normal development and physiologic adaptation of renin-producing cells. In addition, deletion of Vhl shifts the phenotype of juxtaglomerular cells from a renin- to erythropoietin-secreting cell type, presumably in response to HIF-2 accumulation.
Assuntos
Eritropoetina/biossíntese , Rim/metabolismo , Renina/biossíntese , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Eritropoetina/genética , Marcação de Genes , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Sistema Justaglomerular/metabolismo , Sistema Justaglomerular/patologia , Rim/irrigação sanguínea , Rim/patologia , Masculino , Camundongos , Camundongos Knockout , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Renina/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genéticaRESUMO
Renin-expressing cells in the kidney normally appear as mural cells of developing preglomerular vessels and finally impose as granulated juxtaglomerular cells in adult kidneys. The differentiation of renin-expressing cells from the metanephric mesenchyme in general and the potential role of special precursor stages in particular is not well understood. Therefore, it was the aim of this study to search for renin cell precursors in the kidney. As an experimental model, we used kidneys of aldosterone synthase-deficient mice, which display a prominent compensatory overproduction of renin cells that are arranged in multilayered perivascular cell clusters. We found that the perivascular cell clusters contained two apparently distinct cell types, one staining positive for renin and another one staining positive for type I procollagen (PC1). It appeared as if PC1 and renin expression were inversely related at the cellular level. The proportion of renin-positive to PC1-positive cells in the clusters was inversely linked to the rate of salt intake, as was overall renin expression. Our findings suggest that the cells in the perivascular cell clusters can reversibly switch between PC1 and renin expression and that PC1-expressing cells might be precursors of renin cells. A few of those PC1-positive cells were found also in adult wild-type kidneys in the juxtaglomerular lacis cell area, in which renin expression can be induced on demand.
Assuntos
Colágeno Tipo I/biossíntese , Rim/metabolismo , Renina/fisiologia , Células-Tronco/metabolismo , Animais , Linhagem da Célula , Citocromo P-450 CYP11B2/deficiência , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Imuno-Histoquímica , Sistema Justaglomerular/irrigação sanguínea , Rim/citologia , Córtex Renal/citologia , Córtex Renal/metabolismo , Óperon Lac/genética , Camundongos , Camundongos Knockout , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo RealRESUMO
BACKGROUND: Turpentine-containing substances are considered effective in treating cutaneous bacterial infections, but reliable clinical data are scant. OBJECTIVE: We investigated the efficacy and safety of an ointment containing larch turpentine (from Larix decidua), eucalyptus oil (from Eucalyptus globulus), and turpentine oil (from Pinus pinaster) in outpatients with painful skin abscesses in a randomized, placebo-controlled, double-blind study. INTERVENTION: 116 outpatients with skin abscesses used verum or placebo for 10 days. Sum score of the patient's discomforts, changes in abscess size, rate of therapeutic success, and complete healing served as outcome parameters. RESULTS: Fifty-four patients were treated with verum and 56 with placebo. According to the patient's discomfort sum score, patients in the verum group showed a better improvement compared to the placebo group (7.3 vs. 4.7; p = 0.024), and subjective assessment by the investigators revealed a higher treatment success rate after verum (70% vs. 48%; p = 0.021). Complete healing was documented in 67% of the patients receiving verum versus 46% in the placebo group (p = 0.037). There was a positive trend toward a larger decrease in the abscess sizes in the verum group compared to the placebo group (p = 0.07). CONCLUSION: The ointment studied is an effective and safe option for the treatment of bacterial skin diseases.