Alteração do Transporte de Ácido Úrico na Glicosúria Renal Familiar e Expressão de SGLT2 no Rim Normal e Patológico

Familial renal glucosuria (FRG) is a rare co -dominantly inherited benign phenotype characterized by the presence of glucose in the urine. It is caused by mutations in the SLC5A2 gene that encodes SGLT2, a Na+ -glucose co -transporter. The purpose of our current work was twofold: to characterize the molecular and phenotype findings of an FRG cohort and, in addition, to detail the SGLT2 expression in the adult human kidney. The phenotype of FRG pedigrees was evaluated using direct sequencing for the identification of sequence variations in the SLC5A2 gene. The expression of SGLT2 in the adult human kidney was studied by immunofluorescence on kidney biopsy specimens. In the absence of renal biopsies from FRG individuals, and in order to evaluate the potential disruption of SGLT2 expression in a glucosuric nephropathy, we have selected cases of nucleoside analogues induced proximal tubular toxicity. We identified six novel SLC5A2 mutations in six FRG pedigrees and described the occurrence of hyperuricosuria associated with hypouricaemia in the two probands with the most severe phenotypes. Histopathological studies proved that SGLT2 is localized to the brush -border of the proximal tubular epithelia cell and that this normal pattern was found to be disrupted in cases of nucleoside analogues induced tubulopathy. We present six novel SLC5A2 mutations, further contributing to the allelic heterogeneity in FRG, and identified hyperuricosuria and hypouricaemia as part of the FRG phenotype. SGLT2 is localized to the brush -border of the proximal tubule in the adult human normal kidney, and aberrant expression of the co -transporter may underlie the glucosuria seen with the use of nucleoside analogues

Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of Candida albicans.

The regulatory networks governing morphogenesis of a pleomorphic fungus, Candida albicans are extremely complex and remain to be completely elucidated. This study investigated the function of C. albicans yeast casein kinase 2 (CaYck2p). The yck2Δ/yck2Δ strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the yck2Δ/yck2Δ strain which showed significant upregulation of UME6, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes ALS3, HWP1, and SUN41, all of which are associated with morphogenesis and biofilm architecture. The yck2Δ/yck2Δ strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, CHS2, CHS3, and CHS8. Absence of CaYck2p also affected fungal-host interaction; the yck2Δ/yck2Δ strain had significantly reduced ability to damage host cells. However, the yck2Δ/yck2Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in C. albicans, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions

Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of Candida albicans.

The regulatory networks governing morphogenesis of a pleomorphic fungus, Candida albicans are extremely complex and remain to be completely elucidated. This study investigated the function of C. albicans yeast casein kinase 2 (CaYck2p). The yck2Δ/yck2Δ strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the yck2Δ/yck2Δ strain which showed significant upregulation of UME6, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes ALS3, HWP1, and SUN41, all of which are associated with morphogenesis and biofilm architecture. The yck2Δ/yck2Δ strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, CHS2, CHS3, and CHS8. Absence of CaYck2p also affected fungal-host interaction; the yck2Δ/yck2Δ strain had significantly reduced ability to damage host cells. However, the yck2Δ/yck2Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in C. albicans, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions

Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of <i>Candida albicans</i>

<div><p>The regulatory networks governing morphogenesis of a pleomorphic fungus, <i>Candida albicans</i> are extremely complex and remain to be completely elucidated. This study investigated the function of <i>C</i>. <i>albicans</i> yeast casein kinase 2 (CaYck2p). The <i>yck2Δ/yck2Δ</i> strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the <i>yck2Δ/yck2Δ</i> strain which showed significant upregulation of <i>UME6</i>, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes <i>ALS3</i>, <i>HWP1</i>, and <i>SUN41</i>, all of which are associated with morphogenesis and biofilm architecture. The <i>yck2Δ/yck2Δ</i> strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, <i>CHS2</i>, <i>CHS3</i>, and <i>CHS8</i>. Absence of CaYck2p also affected fungal-host interaction; the <i>yck2Δ/yck2Δ</i> strain had significantly reduced ability to damage host cells. However, the <i>yck2</i>Δ/<i>yck2</i>Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in <i>C</i>. <i>albicans</i>, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions.</p></div

Effect of <i>YCK2</i> deletion on cell wall integrity.

<p><b>A,</b> susceptibility of the indicated strains to various cell wall stressors, 2 mg/ml protamine sulfate, 0.1% SDS, 300 μg/ml congo red, and 10 μg/ml calcofluor white (CFW) after 48 h at 30°C. <b>B,</b> susceptibility of the designated strains to calcineurin inhibitors, 10 μg/ml cyclosporine A and 5 μg/ml FK506 and 5 μg/ml pyrvinium pamoate. Shown are representative images for three independent experiments with the same outcome. <b>C,</b> microscopic analysis of chitin deposition in the cell wall of the wild-type (a, e), the insertion mutant (b, f), the <i>yck2</i>Δ/<i>yck2</i>Δ (c, g), and the complemented (d, h) strains grown in YPD at 30°C and stained with 0.05% calcofluor white.</p

Quantitative gene expression analysis of cell wall synthase genes.

<p><b>A,</b> the relative mRNA expression of chitin synthase genes compared to wild type in the indicated strains grown in YPD at 30°C to mid log phase (** p<0.001 and *** p<0.0001). <b>B,</b> the relative mRNA expression of glucan synthase genes compared to wild type in the indicated strains grown in YPD at 30°C to mid log phase.</p