Proteinúria é a principal manifestação da nefrite lúpica (NL) e reflete lesão no podócito. Análise dos biomarcadores do podócito foi realizada com o objetivo de identificar se o fenótipo podocitário é distinto na NL membranosa pura e proliferativa. Expressão de sinaptopodina, proteína 1 do tumor de Wilms (Wilms tumor protein 1 - WT1), proteína epitelial glomerular 1 (glomerular epitelial protein 1 - GLEPP1) e nefrina foi avaliada em 52 biópsias de NL por imunohistoquímica. Expressão preservada de sinaptopodina foi observada em apenas 10 (19,2%) de todas as biópsias enquanto que 42 (80,8%) apresentavam expressão reduzida. Ambos os grupos tinham proteinúria semelhante no momento da biópsia (p = 0,22), porém, no seguimento médio de quatro anos houve uma tendência para menores níveis médios de proteinúria nos pacientes com marcação preservada de sinaptopodina (0,26 ± 0,23 vs 0,84 ± 0,90 g/24 h, p = 0,05) do que naqueles com expressão reduzida. Trinta e nove (75%) biópsias foram classificadas como proliferativa e treze (25%) como membranosa pura. Comparação dos biomarcadores do podócito demonstrou predomíno de marcação preservada de sinaptopodina (69,2%), WT1 (69,2%), GLEPP1 (53,9%) e nefrina (60%) no grupo membranosa pura enquanto apenas < 10% das proliferativas apresentaram expressão preservada. Nossos dados sugerem que nas classes proliferativas parece haver lesão estrutural do podócito, enquanto que na membranosa pura o padrão predominantemente preservado sugere uma lesão funcional do podócito que pode ser responsável pelo melhor prognóstico a longo prazo do desfecho da proteinúria / Proteinuria is a major feature of lupus nephritis (LN) and reflects podocyte injury. Analysis of podocyte biomarkers was performed attempting to identify if podocyte phenotype is distinct in pure membranous and proliferative LN. Expression of synaptopodin, Wilms tumor protein 1 (WT1), glomerular epithelial protein 1 (GLEPP1) and nephrin was evaluated in 52 LN biopsies by immunohistochemistry. Preserved synaptopodin expression was observed in only 10 (19,2%) of all biopsies while 42 (80,8%) had a reduced expression. Both groups had comparable proteinuria at the time of biopsy (p=0,22), however, in the mean follow-up of four years there was a tendency to lower mean levels of proteinuria in patients with preserved synaptopodin staining (0,26 ± 0,23 vs. 0,84 ± 0,90 g/24 h, p=0,05) than those with diminished expression. Thirty-nine (75%) biopsies were classified as proliferative and thirteen (25%) as pure membranous. Comparison of podocyte biomarkers demonstrated a predominance of preserved staining of synaptopodin (69,2%), WT1 (69,2%), GLEPP1 (53,9%) and nephrin (60%) in the pure membranous group whereas only < 10% of the proliferative showed preserved expression. Our data suggest that in proliferative forms there seems to occur structural podocyte damage, whereas in the pure membranous the predominant preserved pattern suggests a dysfunctional podocyte lesion that may account for the better long-term prognosis of proteinuria outcome

Introdução: A lesão do podócito exerce um papel crítico na nefropatia diabética (ND) e é um fator preditivo de albuminúria patológica e progressão da doença. Neste estudo foi avaliada a expressão gênica de proteínas associadas ao podócito na urina de pacientes diabéticos em diferentes estágios da ND e em indivíduos com pré diabetes. Material e Métodos: Foram estudados 67 pacientes diabéticos com normo (n=34), micro (n=14) ou macroalbuminúria (n=19), dezenove indivíduos pré diabéticos e 15 controles saudáveis. O RNAm de nefrina, podocina, podocalixina, sinaptopodina, Transient Receptor Potential Cation Channel 6 (TRPC6), alfa actinina-4 e TGF1 foi quantificado por PCR em tempo real (2-ΔΔCt) em células do sedimento urinário. A expressão dos genes alvo do podócito foi correlacionada com albuminúria, controle glicêmico e função renal. O desempenho diagnóstico dos genes para albuminúria patológica foi determinado por curva ROC, e o seu efeito independente sobre esse desfecho foi avaliado por análise de regressão de Poisson. Resultados: O RNAm na urina dos genes alvo foi significativamente maior nos pacientes diabéticos em comparação aos não diabéticos, exceto de sinaptopodina e TGFβ1. A expressão de nefrina foi mais elevada nos indivíduos diabéticos micro e macroalbuminúricos comparado aos controles (p=0,04 e p<0,001 respectivamente), pré diabéticos (p<0,05) e normoalbuminúricos (p<0,05). Embora sua expressão tenha sido maior do que nos não diabéticos, os genes TRPC6, podocalixina e alfa actinina-4 não discriminaram os estágios da ND. A correlação da expressão dos genes com albuminúria e hemoglobina glicada foi estatisticamente significativa. Pacientes pré diabéticos tiveram expressão gênica semelhante aos controles. Na análise multivariada, apenas o gene da nefrina foi preditivo de albuminúria patológica. 6 Conclusões: A expressão das proteínas associadas ao podócito na urina foi maior nos pacientes diabéticos, mas não houve correlação direta do RNAm dos genes com níveis crescentes de albuminúria, exceto de nefrina. O gene da nefrina foi o único que discriminou os diferentes estágios da ND e foi preditivo de albuminúria patológica, mas a podocalixina e o TRPC6 também se correlacionaram com albuminúria e controle glicêmico. Neste estudo preliminar não se identificou aumento da expressão gênica das proteínas do podócito na urina em indivíduos com pré diabetes. / Introduction: Podocyte damage plays a critical role in the development of diabetic nephropathy (DN). The present study evaluated gene expression of podocyte-associated proteins in urine of pre-diabetic and diabetic patients at different stages of DN. Material and Methods: We studied 19 pre-diabetic patients, 67 diabetic patients with normo (n = 34), micro (n = 15), or macroalbuminuria (n = 19), and 15 healthy controls. Levels of mRNA of nephrin, podocin, podocalyxin, synaptopodin, transient receptor potential cation channel 6 (TRPC6), alpha-actinin-4, and TGF-1 were quantitatively measured by real-time polymerase chain reaction in urinary sediment. Gene expression was correlated with albuminuria, glycemic control, and renal function. The diagnostic performance of the genes for detecting pathological albuminuria was assessed by the receiver operating characteristic (ROC) curve and Poisson regression. Results: The mRNA expression of target genes in urinary sediment was significantly higher in diabetic compared to pre-diabetic patients and controls. Levels of nephrin were higher in diabetic patients with micro or macroalbuminuria than controls (p= 0.04 and p<0.001, respectively), pre-diabetic (p<0.05), and diabetic patients with normoalbuminuria (p<0.05), and increased with increasing rates of albuminuria. Gene expression was similar in pre-diabetic patients and controls. There was a significant positive correlation of gene expression with albuminuria and glycated hemoglobin. In the multivariate analysis, only nephrinuria predicted pathological albuminuria. Conclusions: The expression of podocyte-associated proteins in urine was higher in diabetic patients, but only nephrin correlated with increasing albuminuria and predicted 8 pathological albuminuria. This preliminary study did not find increased gene transcription in pre-diabetic patients.

Proteinúria é a principal manifestação da nefrite lúpica (NL) e reflete lesão no podócito. Análise dos biomarcadores do podócito foi realizada com o objetivo de identificar se o fenótipo podocitário é distinto na NL membranosa pura e proliferativa. Expressão de sinaptopodina, proteína 1 do tumor de Wilms (Wilms tumor protein 1 - WT1), proteína epitelial glomerular 1 (glomerular epitelial protein 1 - GLEPP1) e nefrina foi avaliada em 52 biópsias de NL por imunohistoquímica. Expressão preservada de sinaptopodina foi observada em apenas 10 (19,2%) de todas as biópsias enquanto que 42 (80,8%) apresentavam expressão reduzida. Ambos os grupos tinham proteinúria semelhante no momento da biópsia (p = 0,22), porém, no seguimento médio de quatro anos houve uma tendência para menores níveis médios de proteinúria nos pacientes com marcação preservada de sinaptopodina (0,26 ± 0,23 vs 0,84 ± 0,90 g/24 h, p = 0,05) do que naqueles com expressão reduzida. Trinta e nove (75%) biópsias foram classificadas como proliferativa e treze (25%) como membranosa pura. Comparação dos biomarcadores do podócito demonstrou predomíno de marcação preservada de sinaptopodina (69,2%), WT1 (69,2%), GLEPP1 (53,9%) e nefrina (60%) no grupo membranosa pura enquanto apenas < 10% das proliferativas apresentaram expressão preservada. Nossos dados sugerem que nas classes proliferativas parece haver lesão estrutural do podócito, enquanto que na membranosa pura o padrão predominantemente preservado sugere uma lesão funcional do podócito que pode ser responsável pelo melhor prognóstico a longo prazo do desfecho da proteinúria / Proteinuria is a major feature of lupus nephritis (LN) and reflects podocyte injury. Analysis of podocyte biomarkers was performed attempting to identify if podocyte phenotype is distinct in pure membranous and proliferative LN. Expression of synaptopodin, Wilms tumor protein 1 (WT1), glomerular epithelial protein 1 (GLEPP1) and nephrin was evaluated in 52 LN biopsies by immunohistochemistry. Preserved synaptopodin expression was observed in only 10 (19,2%) of all biopsies while 42 (80,8%) had a reduced expression. Both groups had comparable proteinuria at the time of biopsy (p=0,22), however, in the mean follow-up of four years there was a tendency to lower mean levels of proteinuria in patients with preserved synaptopodin staining (0,26 ± 0,23 vs. 0,84 ± 0,90 g/24 h, p=0,05) than those with diminished expression. Thirty-nine (75%) biopsies were classified as proliferative and thirteen (25%) as pure membranous. Comparison of podocyte biomarkers demonstrated a predominance of preserved staining of synaptopodin (69,2%), WT1 (69,2%), GLEPP1 (53,9%) and nephrin (60%) in the pure membranous group whereas only < 10% of the proliferative showed preserved expression. Our data suggest that in proliferative forms there seems to occur structural podocyte damage, whereas in the pure membranous the predominant preserved pattern suggests a dysfunctional podocyte lesion that may account for the better long-term prognosis of proteinuria outcome

The incidence of chronic kidney disease (CKD) is increasing. CKD is characterized by a gradual decrease in renal function leading to end stage renal disease (ESRD). Damage to the glomerular podocytes, is one of the first hallmarks of CKD. We hypothesized that podocyte prostaglandin E2 (PGE2) receptors contribute to the progression of glomerular injury in models of CKD. To test this hypothesis, transgenic mice were generated with either podocyte-specific overexpression or deletion of the PGE2 EP4 receptor (EP4pod+and EP4pod-/- respectively). Mice were next tested in the 5/6 nephrectomy (5/6 Nx) or angiotensin II (Ang II) models of CKD. These studies revealed increased proteinuria and decreased survival for EP4pod+ mice while EP4pod-/- mice were protected against the development of glomerular injury. Furthermore, our findings were supported by in vitro studies using cultured mouse podocytes where an adhesion defect was uncovered for cells overexpressing the EP4 receptor. Additionally, our investigations have demonstrated a novel synergy between angiotensin II AT1 receptors and prostaglandin E2 EP4 receptors. This was revealed by in vitro studies using isolated mouse glomeruli. There we were able to show that Ang II stimulation leads to increased expression of cyclooxygenase 2 (COX-2), the enzyme responsible for synthesis of PGE2, in a p38 mitogen activated protein kinase (MAPK) dependent fashion. Moreover increased PGE2 synthesis was measured in response to Ang II stimulation. We confirmed the presence of this synergy in our cultured mouse podocytes and showed an adhesion defect in response to Ang II stimulation which was COX-2 and EP4 dependent. These findings suggest that Ang II AT1 receptors and PGE2 EP4 receptors act in concert to exacerbate glomerulopathies. Studies using mice with either podocyte-specific overexpression of a dominant negative p38 MAPK or mice with global deletion of the EP1 receptor did not provide conclusive results as to their respective signaling involvement in podocyte injury. Altogether our findings provide novel insight for podocyte PGE2 EP4 and Ang II AT1 receptor signaling in models of CKD. These studies provide novel avenues for pursuing therapeutic interventions for individuals with progressive kidney disease.

The incidence of chronic kidney disease (CKD) is increasing. CKD is characterized by a gradual decrease in renal function leading to end stage renal disease (ESRD). Damage to the glomerular podocytes, is one of the first hallmarks of CKD. We hypothesized that podocyte prostaglandin E2 (PGE2) receptors contribute to the progression of glomerular injury in models of CKD. To test this hypothesis, transgenic mice were generated with either podocyte-specific overexpression or deletion of the PGE2 EP4 receptor (EP4pod+and EP4pod-/- respectively). Mice were next tested in the 5/6 nephrectomy (5/6 Nx) or angiotensin II (Ang II) models of CKD. These studies revealed increased proteinuria and decreased survival for EP4pod+ mice while EP4pod-/- mice were protected against the development of glomerular injury. Furthermore, our findings were supported by in vitro studies using cultured mouse podocytes where an adhesion defect was uncovered for cells overexpressing the EP4 receptor. Additionally, our investigations have demonstrated a novel synergy between angiotensin II AT1 receptors and prostaglandin E2 EP4 receptors. This was revealed by in vitro studies using isolated mouse glomeruli. There we were able to show that Ang II stimulation leads to increased expression of cyclooxygenase 2 (COX-2), the enzyme responsible for synthesis of PGE2, in a p38 mitogen activated protein kinase (MAPK) dependent fashion. Moreover increased PGE2 synthesis was measured in response to Ang II stimulation. We confirmed the presence of this synergy in our cultured mouse podocytes and showed an adhesion defect in response to Ang II stimulation which was COX-2 and EP4 dependent. These findings suggest that Ang II AT1 receptors and PGE2 EP4 receptors act in concert to exacerbate glomerulopathies. Studies using mice with either podocyte-specific overexpression of a dominant negative p38 MAPK or mice with global deletion of the EP1 receptor did not provide conclusive results as to their respective signaling involvement in podocyte injury. Altogether our findings provide novel insight for podocyte PGE2 EP4 and Ang II AT1 receptor signaling in models of CKD. These studies provide novel avenues for pursuing therapeutic interventions for individuals with progressive kidney disease.

Podocytes are specialized epithelial cells which wrap glomerular capillaries with numerous interdigitating foot processes (FP). Between adjacent FPs a unique junction, the slit diaphragm (SD), functions as the final blood filtration barrier. Actin organization is critical for maintaining FP structure and SD function, and the adaptor protein Nck can bind an intracellular SD component to couple it with actin regulators. Podocyte-specific deletion of Nck in mice results in proteinuria and FP effacement. To better understand FP remodelling, we have pursued a transgenic mouse model utilizing an inducible and reversible dominant negative Nck (DN-Nck) to prevent signalling to actin regulators, exclusively in podocytes. Effects of DN-Nck were first confirmed in vitro, and transgenic mice were then generated and induced to express DN-Nck. Despite obtaining several mice which exhibited a mild renal phenotype, transgene expression appeared to be lost in successive generations. Full in vivo analysis awaits generation of additional transgenic founders.

The incidence of chronic kidney disease (CKD) is increasing. CKD is characterized by a gradual decrease in renal function leading to end stage renal disease (ESRD). Damage to the glomerular podocytes, is one of the first hallmarks of CKD. We hypothesized that podocyte prostaglandin E2 (PGE2) receptors contribute to the progression of glomerular injury in models of CKD. To test this hypothesis, transgenic mice were generated with either podocyte-specific overexpression or deletion of the PGE2 EP4 receptor (EP4pod+and EP4pod-/- respectively). Mice were next tested in the 5/6 nephrectomy (5/6 Nx) or angiotensin II (Ang II) models of CKD. These studies revealed increased proteinuria and decreased survival for EP4pod+ mice while EP4pod-/- mice were protected against the development of glomerular injury. Furthermore, our findings were supported by in vitro studies using cultured mouse podocytes where an adhesion defect was uncovered for cells overexpressing the EP4 receptor. Additionally, our investigations have demonstrated a novel synergy between angiotensin II AT1 receptors and prostaglandin E2 EP4 receptors. This was revealed by in vitro studies using isolated mouse glomeruli. There we were able to show that Ang II stimulation leads to increased expression of cyclooxygenase 2 (COX-2), the enzyme responsible for synthesis of PGE2, in a p38 mitogen activated protein kinase (MAPK) dependent fashion. Moreover increased PGE2 synthesis was measured in response to Ang II stimulation. We confirmed the presence of this synergy in our cultured mouse podocytes and showed an adhesion defect in response to Ang II stimulation which was COX-2 and EP4 dependent. These findings suggest that Ang II AT1 receptors and PGE2 EP4 receptors act in concert to exacerbate glomerulopathies. Studies using mice with either podocyte-specific overexpression of a dominant negative p38 MAPK or mice with global deletion of the EP1 receptor did not provide conclusive results as to their respective signaling involvement in podocyte injury. Altogether our findings provide novel insight for podocyte PGE2 EP4 and Ang II AT1 receptor signaling in models of CKD. These studies provide novel avenues for pursuing therapeutic interventions for individuals with progressive kidney disease.

Although the etiology of diabetic nephropathy is still uncertain, proteinuria due to podocyte injury and loss (podocytopenia) are early features of the disease. Significant increases in thromboxane A2 (TXA2) production as well as expression of its receptor in animal models of diabetic nephropathy led to the hypothesis that TXA2 acting via its thromboxane-prostanoid (TP) receptor induces podocytopenia resulting in proteinuria. Systemic infusion of a TP antagonist demonstrated an important role of TXA2/TP signalling in our model of streptozotocin induced type-1 diabetic nephropathy by reducing kidney damage including proteinuria. Podocyte specific TP overexpressing mice did not demonstrate more pathologic or dynamic kidney damage than non-transgenic mice in STZ-induced diabetic nephropathy. Further assessment of the TP transgene functionality in this mice line is necessary to validate those results. Whereas the importance of TXA2/TP signalling is undeniable in diabetic nephropathy, it appears that podocyte TP receptors might not be directly targeted.

Introdução: A lesão do podócito exerce um papel crítico na nefropatia diabética (ND) e é um fator preditivo de albuminúria patológica e progressão da doença. Neste estudo foi avaliada a expressão gênica de proteínas associadas ao podócito na urina de pacientes diabéticos em diferentes estágios da ND e em indivíduos com pré diabetes. Material e Métodos: Foram estudados 67 pacientes diabéticos com normo (n=34), micro (n=14) ou macroalbuminúria (n=19), dezenove indivíduos pré diabéticos e 15 controles saudáveis. O RNAm de nefrina, podocina, podocalixina, sinaptopodina, Transient Receptor Potential Cation Channel 6 (TRPC6), alfa actinina-4 e TGF1 foi quantificado por PCR em tempo real (2-ΔΔCt) em células do sedimento urinário. A expressão dos genes alvo do podócito foi correlacionada com albuminúria, controle glicêmico e função renal. O desempenho diagnóstico dos genes para albuminúria patológica foi determinado por curva ROC, e o seu efeito independente sobre esse desfecho foi avaliado por análise de regressão de Poisson. Resultados: O RNAm na urina dos genes alvo foi significativamente maior nos pacientes diabéticos em comparação aos não diabéticos, exceto de sinaptopodina e TGFβ1. A expressão de nefrina foi mais elevada nos indivíduos diabéticos micro e macroalbuminúricos comparado aos controles (p=0,04 e p<0,001 respectivamente), pré diabéticos (p<0,05) e normoalbuminúricos (p<0,05). Embora sua expressão tenha sido maior do que nos não diabéticos, os genes TRPC6, podocalixina e alfa actinina-4 não discriminaram os estágios da ND. A correlação da expressão dos genes com albuminúria e hemoglobina glicada foi estatisticamente significativa. Pacientes pré diabéticos tiveram expressão gênica semelhante aos controles. Na análise multivariada, apenas o gene da nefrina foi preditivo de albuminúria patológica. 6 Conclusões: A expressão das proteínas associadas ao podócito na urina foi maior nos pacientes diabéticos, mas não houve correlação direta do RNAm dos genes com níveis crescentes de albuminúria, exceto de nefrina. O gene da nefrina foi o único que discriminou os diferentes estágios da ND e foi preditivo de albuminúria patológica, mas a podocalixina e o TRPC6 também se correlacionaram com albuminúria e controle glicêmico. Neste estudo preliminar não se identificou aumento da expressão gênica das proteínas do podócito na urina em indivíduos com pré diabetes. / Introduction: Podocyte damage plays a critical role in the development of diabetic nephropathy (DN). The present study evaluated gene expression of podocyte-associated proteins in urine of pre-diabetic and diabetic patients at different stages of DN. Material and Methods: We studied 19 pre-diabetic patients, 67 diabetic patients with normo (n = 34), micro (n = 15), or macroalbuminuria (n = 19), and 15 healthy controls. Levels of mRNA of nephrin, podocin, podocalyxin, synaptopodin, transient receptor potential cation channel 6 (TRPC6), alpha-actinin-4, and TGF-1 were quantitatively measured by real-time polymerase chain reaction in urinary sediment. Gene expression was correlated with albuminuria, glycemic control, and renal function. The diagnostic performance of the genes for detecting pathological albuminuria was assessed by the receiver operating characteristic (ROC) curve and Poisson regression. Results: The mRNA expression of target genes in urinary sediment was significantly higher in diabetic compared to pre-diabetic patients and controls. Levels of nephrin were higher in diabetic patients with micro or macroalbuminuria than controls (p= 0.04 and p<0.001, respectively), pre-diabetic (p<0.05), and diabetic patients with normoalbuminuria (p<0.05), and increased with increasing rates of albuminuria. Gene expression was similar in pre-diabetic patients and controls. There was a significant positive correlation of gene expression with albuminuria and glycated hemoglobin. In the multivariate analysis, only nephrinuria predicted pathological albuminuria. Conclusions: The expression of podocyte-associated proteins in urine was higher in diabetic patients, but only nephrin correlated with increasing albuminuria and predicted 8 pathological albuminuria. This preliminary study did not find increased gene transcription in pre-diabetic patients.

Introdução: A lesão do podócito exerce um papel crítico na nefropatia diabética (ND) e é um fator preditivo de albuminúria patológica e progressão da doença. Neste estudo foi avaliada a expressão gênica de proteínas associadas ao podócito na urina de pacientes diabéticos em diferentes estágios da ND e em indivíduos com pré diabetes. Material e Métodos: Foram estudados 67 pacientes diabéticos com normo (n=34), micro (n=14) ou macroalbuminúria (n=19), dezenove indivíduos pré diabéticos e 15 controles saudáveis. O RNAm de nefrina, podocina, podocalixina, sinaptopodina, Transient Receptor Potential Cation Channel 6 (TRPC6), alfa actinina-4 e TGF1 foi quantificado por PCR em tempo real (2-ΔΔCt) em células do sedimento urinário. A expressão dos genes alvo do podócito foi correlacionada com albuminúria, controle glicêmico e função renal. O desempenho diagnóstico dos genes para albuminúria patológica foi determinado por curva ROC, e o seu efeito independente sobre esse desfecho foi avaliado por análise de regressão de Poisson. Resultados: O RNAm na urina dos genes alvo foi significativamente maior nos pacientes diabéticos em comparação aos não diabéticos, exceto de sinaptopodina e TGFβ1. A expressão de nefrina foi mais elevada nos indivíduos diabéticos micro e macroalbuminúricos comparado aos controles (p=0,04 e p<0,001 respectivamente), pré diabéticos (p<0,05) e normoalbuminúricos (p<0,05). Embora sua expressão tenha sido maior do que nos não diabéticos, os genes TRPC6, podocalixina e alfa actinina-4 não discriminaram os estágios da ND. A correlação da expressão dos genes com albuminúria e hemoglobina glicada foi estatisticamente significativa. Pacientes pré diabéticos tiveram expressão gênica semelhante aos controles. Na análise multivariada, apenas o gene da nefrina foi preditivo de albuminúria patológica. 6 Conclusões: A expressão das proteínas associadas ao podócito na urina foi maior nos pacientes diabéticos, mas não houve correlação direta do RNAm dos genes com níveis crescentes de albuminúria, exceto de nefrina. O gene da nefrina foi o único que discriminou os diferentes estágios da ND e foi preditivo de albuminúria patológica, mas a podocalixina e o TRPC6 também se correlacionaram com albuminúria e controle glicêmico. Neste estudo preliminar não se identificou aumento da expressão gênica das proteínas do podócito na urina em indivíduos com pré diabetes. / Introduction: Podocyte damage plays a critical role in the development of diabetic nephropathy (DN). The present study evaluated gene expression of podocyte-associated proteins in urine of pre-diabetic and diabetic patients at different stages of DN. Material and Methods: We studied 19 pre-diabetic patients, 67 diabetic patients with normo (n = 34), micro (n = 15), or macroalbuminuria (n = 19), and 15 healthy controls. Levels of mRNA of nephrin, podocin, podocalyxin, synaptopodin, transient receptor potential cation channel 6 (TRPC6), alpha-actinin-4, and TGF-1 were quantitatively measured by real-time polymerase chain reaction in urinary sediment. Gene expression was correlated with albuminuria, glycemic control, and renal function. The diagnostic performance of the genes for detecting pathological albuminuria was assessed by the receiver operating characteristic (ROC) curve and Poisson regression. Results: The mRNA expression of target genes in urinary sediment was significantly higher in diabetic compared to pre-diabetic patients and controls. Levels of nephrin were higher in diabetic patients with micro or macroalbuminuria than controls (p= 0.04 and p<0.001, respectively), pre-diabetic (p<0.05), and diabetic patients with normoalbuminuria (p<0.05), and increased with increasing rates of albuminuria. Gene expression was similar in pre-diabetic patients and controls. There was a significant positive correlation of gene expression with albuminuria and glycated hemoglobin. In the multivariate analysis, only nephrinuria predicted pathological albuminuria. Conclusions: The expression of podocyte-associated proteins in urine was higher in diabetic patients, but only nephrin correlated with increasing albuminuria and predicted 8 pathological albuminuria. This preliminary study did not find increased gene transcription in pre-diabetic patients.