Alejandra Droguett - Academia.edu (original) (raw)

Papers by Alejandra Droguett

Research paper thumbnail of Tubular overexpression of Gremlin in transgenic mice aggravates renal damage in diabetic nephropathy

American Journal of Physiology-Renal Physiology, 2015

Diabetic nephropathy (DN) is currently a leading cause of end-stage renal failure worldwide. Grem... more Diabetic nephropathy (DN) is currently a leading cause of end-stage renal failure worldwide. Gremlin was identified as a gene differentially expressed in mesangial cells exposed to high glucose and in experimental diabetic kidneys. We have described that Gremlin is highly expressed in biopsies from patients with diabetic nephropathy, predominantly in areas of tubulointerstitial fibrosis. In streptozotocin (STZ)-induced experimental diabetes, Gremlin deletion using Grem1 heterozygous knockout mice or by gene silencing, ameliorates renal damage. To study the in vivo role of Gremlin in renal damage, we developed a diabetic model induced by STZ in transgenic (TG) mice expressing human Gremlin in proximal tubular epithelial cells. The albuminuria/creatinuria ratio, determined at week 20 after treatment, was significantly increased in diabetic mice but with no significant differences between transgenic (TG/STZ) and wild-type mice (WT/STZ). To assess the level of renal damage, kidney tissu...

Research paper thumbnail of Renin-angiotensin system activation and interstitial inflammation in human diabetic nephropathy

Kidney international. Supplement, 2003

The molecular mechanisms of renal injury in diabetic nephropathy (DN) are not completely understo... more The molecular mechanisms of renal injury in diabetic nephropathy (DN) are not completely understood, although inflammatory cells play a key role. The renin-angiotensin system (RAS) is involved in kidney damage; however, few studies have examined the localization of RAS components in human DN. Our aim was to investigate in renal biopsies the expression of RAS and their correlation with proinflammatory parameters and renal injury. The biopsies from 10 patients with type 2 diabetes mellitus and overt nephropathy were studied for the expression of RAS components by immunohistochemistry (IH). In addition, by Southwestern histochemistry we studied the in situ detection of the activated nuclear factor kappa B (NFkappaB), and by IH and/or in situ hybridization (ISH), the expression of monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T cell expressed and secreted (RANTES), whose genes are regulated by NFkappaB. Angiotensin-converting enzyme (ACE) immunostainin...

Research paper thumbnail of Renal angiotensin II up-regulation and myofibroblast activation in human membranous nephropathy

Kidney international. Supplement, 2003

The molecular mechanisms of renal injury and fibrosis in proteinuric nephropathies are not comple... more The molecular mechanisms of renal injury and fibrosis in proteinuric nephropathies are not completely elucidated but the renin-angiotensin system (RAS) is involved. Idiopathic membranous nephropathy (MN), a proteinuric disease, may progress to renal failure. Our aim was to investigate the localization of RAS components in MN and their correlation with profibrotic parameters and renal injury. Renal biopsies from 20 patients with MN (11 with progressive disease) were studied for the expression of RAS components [angiotensin-converting enzyme (ACE) and angiotensin II (Ang II)] by immunohistochemistry. Transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF)-BB were studied by by in situ hybridization, and myofibroblast transdifferentiation by alpha-smooth muscle actin (alpha-SMA) staining. ACE immunostaining was elevated in tubular cells and appeared in interstitial cells colocalized in alpha-actin-positive cells in progressive disease. Elevated levels of An...

Research paper thumbnail of Anti-inflammatory, antioxidant and renoprotective effects of SOCS1 mimetic peptide in the BTBR ob/ob mouse model of type 2 diabetes

BMJ Open Diabetes Research & Care

IntroductionDiabetic nephropathy (DN) is the leading cause of chronic kidney disease worldwide. T... more IntroductionDiabetic nephropathy (DN) is the leading cause of chronic kidney disease worldwide. The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway participates in the development and progression of DN. Among the different mechanisms involved in JAK/STAT negative regulation, the family of suppressor of cytokine signaling (SOCS) proteins has been proposed as a new target for DN. Our aim was to evaluate the effect of SOCS1 mimetic peptide in a mouse model of obesity and type 2 diabetes (T2D) with progressive DN.Research design and methodsSix-week-old BTBR (black and tan brachyuric) mice with the ob/ob (obese/obese) leptin-deficiency mutation were treated for 7 weeks with two different doses of active SOCS1 peptide (MiS1 2 and 4 µg/g body weight), using inactive mutant peptide (Mut 4 µg) and vehicle as control groups. At the end of the study, the animals were sacrificed to obtain blood, urine and kidney tissue for further analysis.ResultsTreatment of ...

Research paper thumbnail of Targeting NF-κB by the Cell-Permeable NEMO-Binding Domain Peptide Improves Albuminuria and Renal Lesions in an Experimental Model of Type 2 Diabetic Nephropathy

International Journal of Molecular Sciences

Diabetic nephropathy (DN) is a multifactorial disease characterized by hyperglycemia and close in... more Diabetic nephropathy (DN) is a multifactorial disease characterized by hyperglycemia and close interaction of hemodynamic, metabolic and inflammatory factors. Nuclear factor-κB (NF-κB) is a principal matchmaker linking hyperglycemia and inflammation. The present work investigates the cell-permeable peptide containing the inhibitor of kappa B kinase γ (IKKγ)/NF-κB essential modulator (NEMO)-binding domain (NBD) as therapeutic option to modulate inflammation in a preclinical model of type 2 diabetes (T2D) with DN. Black and tan, brachyuric obese/obese mice were randomized into 4 interventions groups: Active NBD peptide (10 and 6 µg/g body weight); Inactive mutant peptide (10 µg/g); and vehicle control. In vivo/ex vivo fluorescence imaging revealed efficient delivery of NBD peptide, systemic biodistribution and selective renal metabolization. In vivo administration of active NBD peptide improved albuminuria (>40% reduction on average) and kidney damage, decreased podocyte loss and b...

Research paper thumbnail of Gremlin, A Potential Urinary Biomarker of Anca-Associated Crescentic Glomerulonephritis

Scientific Reports, May 3, 2019

Gremlin renal overexpression has been reported in diabetic nephropathy, pauci-immune crescentic g... more Gremlin renal overexpression has been reported in diabetic nephropathy, pauci-immune crescentic glomerulonephritis and chronic allograft nephropathy and has been implicated in the pathophysiology of the progression of renal damage. However, it is unknown whether urinary Gremlin can be associated with renal functional status, renal biopsy findings and outcome. To examine these associations we studied 20 patients with ANCA+ renal vasculitis and very high urinary Gremlin (354 ± 76 ug/gCr), 86 patients with other glomerular diseases and moderately elevated urinary Gremlin (83 ± 14 ug/gCr) and 11 healthy controls (urinary Gremlin 11.3 ± 2.4 ug/gCr). Urinary Gremlin was significantly correlated with renal expression of Gremlin (r = 0.64, p = 0.013) observed in cellular glomerular crescents, tubular epithelial cells and interstitial inflammatory cells. Moreover, urinary Gremlin levels were correlated with the number of glomerular crescents (r = 0.53; p < 0.001), renal CD68 positive cells (r = 0.71; p < 0.005), tubulointerstitial fibrosis (r = 0.50; p < 0.05), and serum creatinine levels (r = 0.60; p < 0.001). Interestingly, Gremlin expression was colocalized with CD68, CD163 (monocyte/macrophage markers) and CCL18 positive cells. ROC curve analysis showed that the cutoff value of urinary Gremlin in glomerular diseases as 43 ug/gCr with 72% of sensitivity and 100% of specificity [AUC: 0.96 (CI 95% 0.92–0.99] (p < 0.001). For ANCA+ renal vasculitis the value of urinary Gremlin of 241 ug/gCr had 55% of sensitivity and 100% of specificity [AUC: 0.81 (CI 95% 0.68–0.94) (p < 0.001]. Based on these results we propose that urinary Gremlin represents a non-invasive biomarker in ANCA+ renal vasculitis, and suggest a role of Gremlin in the formation of crescents.

Research paper thumbnail of Could IL-17A Be a Novel Therapeutic Target in Diabetic Nephropathy?

Journal of Clinical Medicine

Chronic kidney disease has become a major medical issue in recent years due to its high prevalenc... more Chronic kidney disease has become a major medical issue in recent years due to its high prevalence worldwide, its association with premature mortality, and its social and economic implications. A number of patients gradually progress to end-stage renal disease (ESRD), requiring then dialysis and kidney transplantation. Currently, approximately 40% of patients with diabetes develop kidney disease, making it the most prevalent cause of ESRD. Thus, more effective therapies for diabetic nephropathy are needed. In preclinical studies of diabetes, anti-inflammatory therapeutic strategies have been used to protect the kidneys. Recent evidence supports that immune cells play an active role in the pathogenesis of diabetic nephropathy. Th17 immune cells and their effector cytokine IL-17A have recently emerged as promising targets in several clinical conditions, including renal diseases. Here, we review current knowledge regarding the involvement of Th17/IL-17A in the genesis of diabetic renal...

Research paper thumbnail of Interleukin-17A blockade reduces albuminuria and kidney injury in an accelerated model of diabetic nephropathy

Kidney International

Some clinical trials blocking IL-17A have proven beneficial effects in chronic inflammatory disea... more Some clinical trials blocking IL-17A have proven beneficial effects in chronic inflammatory diseases. Novel therapeutic options to prevent renal damage clinically are unmet for diabetic nephropathy (DN). Our preclinical data suggest that treatment with neutralizing IL-17A antibodies could be a therapeutic option for diabetic patients with albuminuria.

Research paper thumbnail of FP448TUBULAR Overexpression of Gremlin in Transgenic Mice Aggravates Renal Damage in Diabetic Nephropathy

Nephrology Dialysis Transplantation, 2015

Research paper thumbnail of Correction: Tubular Overexpression of Gremlin Induces Renal Damage Susceptibility in Mice

Research paper thumbnail of Tubular NF-κB and AP1 activation in human proteinuric renal disease

Kidney International - KIDNEY INT, 2001

Tubular NF-κB and AP-1 activation in human proteinuric renal disease.BackgroundNuclear factor-κB ... more Tubular NF-κB and AP-1 activation in human proteinuric renal disease.BackgroundNuclear factor-κB (NF-κB) and activated protein-1 (AP-1) are transcription factors that regulate many genes involved in the progression of renal disease. Recent data have shown that NF-κB is activated in tubules and glomeruli in various experimental models of renal injury. In vitro studies also suggest that proteinuria could be an important NF-κB activator. We therefore approached the idea that NF-κB may be an indicator of renal damage progression.MethodsParaffin-embedded renal biopsy specimens from 34 patients with intense proteinuria [14 with minimal change disease (MCD) and 20 with idiopathic membranous nephropathy (MN)] and from 7 patients with minimal or no proteinuria (IgA nephropathy) were studied by Southwestern histochemistry for the in situ detection of activated transcription factors NF-κB and AP-1. In addition, by immunohistochemistry, we performed staining for the NF-κB subunits (p50 and p65)...

Research paper thumbnail of Overexpression of chemokines, fibrogenic cytokines, and myofibroblasts in human membranous nephropathy

Kidney …, 2000

Kidney International aims to inform the renal researcher and practicing nephrologists on all aspe... more Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published ...

Research paper thumbnail of Gremlin and renal diseases: ready to jump the fence to clinical utility?

Nephrology Dialysis Transplantation

Adherence to the Mediterranean diet is associated with reduced risk of incident chronic kidney di... more Adherence to the Mediterranean diet is associated with reduced risk of incident chronic kidney diseases among Tehranian adults.

Research paper thumbnail of NF B activation and overexpression of regulated genes in human diabetic nephropathy

Nephrology Dialysis Transplantation - NEPHROL DIALYSIS TRANSPLANT, 2004

Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such... more Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such as the chemokines monocyte chemoattractant protein-1 (MCP-1) and RANTES. NF-kB is activated in experimental models of renal injury, and in vitro studies also suggest that proteinuria and angiotensin II could be important NF-kB activators. It has been proposed that locally produced MCP-1 may be involved in the development of diabetic nephropathy (DN). We examined the hypothesis that NF-kB could be an indicator of renal damage progression in DN. Methods. Biopsy specimens from 11 patients with type 2 diabeties and overt nephropathy were studied by southwestern histochemistry for the in situ detection of activated NF-kB. In addition, by immunohistochemistry and/or in situ hybridization, we studied the expression of MCP-1 and RANTES, whose genes are regulated by NF-kB. Results. NF-kB was detected mainly in cortical tubular epithelial cells and, to a lesser extent, in some glomerular and interstitial cells. A strong upregulation of MCP-1 and RANTES was observed in all the cases, mainly in tubular cells, and there was a strong correlation between the expression of these chemokines and NF-kB activation in the same cells, as observed in serial sections (r ¼ 0.7; P ¼ 0.01). In addition, the tubular expression of these chemokines was correlated mainly with the magnitude of the proteinuria (P ¼ 0.002) and with interstitial cell infiltration (P<0.05). Conclusions. The activation of NF-kB and the transcription of certain pro-inflammatory chemokines in tubular epithelial cells are markers of progressive DN. Proteinuria might be one of the main factors inducing the observed pro-inflammatory phenotype.

Research paper thumbnail of Gremlin: A novel mediator of epithelial mesenchymal transition and fibrosis in chronic allograft nephropathy

Transplantation Proceedings, 2008

Background. Chronic allograft nephropathy (CAN) is the most frequent cause of chronic dysfunction... more Background. Chronic allograft nephropathy (CAN) is the most frequent cause of chronic dysfunction and late loss of renal allografts. Epithelial mesenchymal transition (EMT) has been identified as responsible for the presence of activated interstitial fibroblasts (myofibroblasts) and transforming growth factor beta (TGF-␤)/Smad is the key signaling mediator. It has been proposed that the bone morphogenetic protein 7 (BMP-7) antagonist, Gremlin, could participate in EMT, as a downstream mediator of TGF-␤. Methods. We evaluated 33 renal allograft biopsies, 16 of which showed CAN, versus 17 controls. By in situ hybridization we studied the expression of TGF-␤ and Gremlin mRNA. Gremlin, BMP-7, E-cadherin, and ␣-smooth muscle actin (␣-SMA) proteins were evaluated by immunohistochemistry and Smad3 activation by Southwestern. In cultured human tubuloepithelial cells (HK2 cell line), Gremlin induction by TGF-␤ was studied by confocal microscopy. Results. Among renal biopsies of transplanted patients with CAN, we detected upregulation of TGF-␤ in colocalization with Gremlin (RNA and protein), mainly in areas of tubulointerstitial fibrosis. In the same tubules, we observed decreased expression of E-cadherin and induction of vimentin and ␣-SMA. BMP-7 was significantly decreased in the CAN biopsies. In addition, HK2 stimulated with TGF-␤ (1 ng/mL) induced Gremlin production at 72 hours. Conclusion. We postulated that Gremlin is a downstream mediator of TGF-␤, suggesting a role for Gremlin in EMT observed in CAN.

Research paper thumbnail of Translational study of the Notch pathway in hypertensive nephropathy

Nefrología : publicación oficial de la Sociedad Española Nefrologia, Jan 21, 2014

The Notch signalling pathway is activated in a wide variety of human renal diseases. We have rece... more The Notch signalling pathway is activated in a wide variety of human renal diseases. We have recently demonstrated that the activation of this pathway is not involved in experimental renal fibrosis induced by angiotensin II or hypertension. To assess whether the Notch pathway is activated in renal fibrosis related to hypertensive nephrosclerosis. To test the hypothesis, various glomerular diseases characterised by tubulointerstitial fibrosis were analysed. Renal biopsies were performed on patients with hypertensive nephrosclerosis, in comparison with diabetic nephropathy and membranous nephropathy at various stages. Gene and protein expression were evaluated by in-situ hybridisation and immunohistochemistry respectively. In hypertensive nephrosclerosis low renal expression of notch-related proteins was observed. There was no link between tubulointerstitial fibrosis and the levels of these proteins. By contrast, in the glomerular diseases studied we observed high expression of the tr...

Research paper thumbnail of Expression of gremlin, a bone morphogenetic protein antagonist, in glomerular crescents of pauci-immune glomerulonephritis

Background. Recent evidence in vitro and in vivo suggests that gremlin, a bone morphogenetic prot... more Background. Recent evidence in vitro and in vivo suggests that gremlin, a bone morphogenetic protein antagonist, is participating in tubular epithelial mesenchymal transition (EMT) in diabetic nephropa- thy as a downstream mediator of TGF-b. Since EMT also occurs in parietal epithelial glomerular cells (PECs) leading to crescent formation, we hypothesized that gremlin could participate in this process. With this aim

Research paper thumbnail of Gremlin Activates the Smad Pathway Linked to Epithelial Mesenchymal Transdifferentiation in Cultured Tubular Epithelial Cells

BioMed Research International, 2014

Research paper thumbnail of Tubular Overexpression of Gremlin Induces Renal Damage Susceptibility in Mice

PLoS ONE, 2014

A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular ... more A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-b. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1) specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2-to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-b and aSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage progression. This transgenic mouse model could be used as a new tool for enhancing the knowledge of renal disease progression.

Research paper thumbnail of NF-kB activation and overexpression of regulated genes in human diabetic nephropathy

Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such... more Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such as the chemokines monocyte chemoattractant protein-1 (MCP-1) and RANTES. NF-kB is activated in experimental models of renal injury, and in vitro studies also suggest that proteinuria and angiotensin II could be important NF-kB activators. It has been proposed that locally produced MCP-1 may be involved in the development

Research paper thumbnail of Tubular overexpression of Gremlin in transgenic mice aggravates renal damage in diabetic nephropathy

American Journal of Physiology-Renal Physiology, 2015

Diabetic nephropathy (DN) is currently a leading cause of end-stage renal failure worldwide. Grem... more Diabetic nephropathy (DN) is currently a leading cause of end-stage renal failure worldwide. Gremlin was identified as a gene differentially expressed in mesangial cells exposed to high glucose and in experimental diabetic kidneys. We have described that Gremlin is highly expressed in biopsies from patients with diabetic nephropathy, predominantly in areas of tubulointerstitial fibrosis. In streptozotocin (STZ)-induced experimental diabetes, Gremlin deletion using Grem1 heterozygous knockout mice or by gene silencing, ameliorates renal damage. To study the in vivo role of Gremlin in renal damage, we developed a diabetic model induced by STZ in transgenic (TG) mice expressing human Gremlin in proximal tubular epithelial cells. The albuminuria/creatinuria ratio, determined at week 20 after treatment, was significantly increased in diabetic mice but with no significant differences between transgenic (TG/STZ) and wild-type mice (WT/STZ). To assess the level of renal damage, kidney tissu...

Research paper thumbnail of Renin-angiotensin system activation and interstitial inflammation in human diabetic nephropathy

Kidney international. Supplement, 2003

The molecular mechanisms of renal injury in diabetic nephropathy (DN) are not completely understo... more The molecular mechanisms of renal injury in diabetic nephropathy (DN) are not completely understood, although inflammatory cells play a key role. The renin-angiotensin system (RAS) is involved in kidney damage; however, few studies have examined the localization of RAS components in human DN. Our aim was to investigate in renal biopsies the expression of RAS and their correlation with proinflammatory parameters and renal injury. The biopsies from 10 patients with type 2 diabetes mellitus and overt nephropathy were studied for the expression of RAS components by immunohistochemistry (IH). In addition, by Southwestern histochemistry we studied the in situ detection of the activated nuclear factor kappa B (NFkappaB), and by IH and/or in situ hybridization (ISH), the expression of monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T cell expressed and secreted (RANTES), whose genes are regulated by NFkappaB. Angiotensin-converting enzyme (ACE) immunostainin...

Research paper thumbnail of Renal angiotensin II up-regulation and myofibroblast activation in human membranous nephropathy

Kidney international. Supplement, 2003

The molecular mechanisms of renal injury and fibrosis in proteinuric nephropathies are not comple... more The molecular mechanisms of renal injury and fibrosis in proteinuric nephropathies are not completely elucidated but the renin-angiotensin system (RAS) is involved. Idiopathic membranous nephropathy (MN), a proteinuric disease, may progress to renal failure. Our aim was to investigate the localization of RAS components in MN and their correlation with profibrotic parameters and renal injury. Renal biopsies from 20 patients with MN (11 with progressive disease) were studied for the expression of RAS components [angiotensin-converting enzyme (ACE) and angiotensin II (Ang II)] by immunohistochemistry. Transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF)-BB were studied by by in situ hybridization, and myofibroblast transdifferentiation by alpha-smooth muscle actin (alpha-SMA) staining. ACE immunostaining was elevated in tubular cells and appeared in interstitial cells colocalized in alpha-actin-positive cells in progressive disease. Elevated levels of An...

Research paper thumbnail of Anti-inflammatory, antioxidant and renoprotective effects of SOCS1 mimetic peptide in the BTBR ob/ob mouse model of type 2 diabetes

BMJ Open Diabetes Research & Care

IntroductionDiabetic nephropathy (DN) is the leading cause of chronic kidney disease worldwide. T... more IntroductionDiabetic nephropathy (DN) is the leading cause of chronic kidney disease worldwide. The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway participates in the development and progression of DN. Among the different mechanisms involved in JAK/STAT negative regulation, the family of suppressor of cytokine signaling (SOCS) proteins has been proposed as a new target for DN. Our aim was to evaluate the effect of SOCS1 mimetic peptide in a mouse model of obesity and type 2 diabetes (T2D) with progressive DN.Research design and methodsSix-week-old BTBR (black and tan brachyuric) mice with the ob/ob (obese/obese) leptin-deficiency mutation were treated for 7 weeks with two different doses of active SOCS1 peptide (MiS1 2 and 4 µg/g body weight), using inactive mutant peptide (Mut 4 µg) and vehicle as control groups. At the end of the study, the animals were sacrificed to obtain blood, urine and kidney tissue for further analysis.ResultsTreatment of ...

Research paper thumbnail of Targeting NF-κB by the Cell-Permeable NEMO-Binding Domain Peptide Improves Albuminuria and Renal Lesions in an Experimental Model of Type 2 Diabetic Nephropathy

International Journal of Molecular Sciences

Diabetic nephropathy (DN) is a multifactorial disease characterized by hyperglycemia and close in... more Diabetic nephropathy (DN) is a multifactorial disease characterized by hyperglycemia and close interaction of hemodynamic, metabolic and inflammatory factors. Nuclear factor-κB (NF-κB) is a principal matchmaker linking hyperglycemia and inflammation. The present work investigates the cell-permeable peptide containing the inhibitor of kappa B kinase γ (IKKγ)/NF-κB essential modulator (NEMO)-binding domain (NBD) as therapeutic option to modulate inflammation in a preclinical model of type 2 diabetes (T2D) with DN. Black and tan, brachyuric obese/obese mice were randomized into 4 interventions groups: Active NBD peptide (10 and 6 µg/g body weight); Inactive mutant peptide (10 µg/g); and vehicle control. In vivo/ex vivo fluorescence imaging revealed efficient delivery of NBD peptide, systemic biodistribution and selective renal metabolization. In vivo administration of active NBD peptide improved albuminuria (>40% reduction on average) and kidney damage, decreased podocyte loss and b...

Research paper thumbnail of Gremlin, A Potential Urinary Biomarker of Anca-Associated Crescentic Glomerulonephritis

Scientific Reports, May 3, 2019

Gremlin renal overexpression has been reported in diabetic nephropathy, pauci-immune crescentic g... more Gremlin renal overexpression has been reported in diabetic nephropathy, pauci-immune crescentic glomerulonephritis and chronic allograft nephropathy and has been implicated in the pathophysiology of the progression of renal damage. However, it is unknown whether urinary Gremlin can be associated with renal functional status, renal biopsy findings and outcome. To examine these associations we studied 20 patients with ANCA+ renal vasculitis and very high urinary Gremlin (354 ± 76 ug/gCr), 86 patients with other glomerular diseases and moderately elevated urinary Gremlin (83 ± 14 ug/gCr) and 11 healthy controls (urinary Gremlin 11.3 ± 2.4 ug/gCr). Urinary Gremlin was significantly correlated with renal expression of Gremlin (r = 0.64, p = 0.013) observed in cellular glomerular crescents, tubular epithelial cells and interstitial inflammatory cells. Moreover, urinary Gremlin levels were correlated with the number of glomerular crescents (r = 0.53; p < 0.001), renal CD68 positive cells (r = 0.71; p < 0.005), tubulointerstitial fibrosis (r = 0.50; p < 0.05), and serum creatinine levels (r = 0.60; p < 0.001). Interestingly, Gremlin expression was colocalized with CD68, CD163 (monocyte/macrophage markers) and CCL18 positive cells. ROC curve analysis showed that the cutoff value of urinary Gremlin in glomerular diseases as 43 ug/gCr with 72% of sensitivity and 100% of specificity [AUC: 0.96 (CI 95% 0.92–0.99] (p < 0.001). For ANCA+ renal vasculitis the value of urinary Gremlin of 241 ug/gCr had 55% of sensitivity and 100% of specificity [AUC: 0.81 (CI 95% 0.68–0.94) (p < 0.001]. Based on these results we propose that urinary Gremlin represents a non-invasive biomarker in ANCA+ renal vasculitis, and suggest a role of Gremlin in the formation of crescents.

Research paper thumbnail of Could IL-17A Be a Novel Therapeutic Target in Diabetic Nephropathy?

Journal of Clinical Medicine

Chronic kidney disease has become a major medical issue in recent years due to its high prevalenc... more Chronic kidney disease has become a major medical issue in recent years due to its high prevalence worldwide, its association with premature mortality, and its social and economic implications. A number of patients gradually progress to end-stage renal disease (ESRD), requiring then dialysis and kidney transplantation. Currently, approximately 40% of patients with diabetes develop kidney disease, making it the most prevalent cause of ESRD. Thus, more effective therapies for diabetic nephropathy are needed. In preclinical studies of diabetes, anti-inflammatory therapeutic strategies have been used to protect the kidneys. Recent evidence supports that immune cells play an active role in the pathogenesis of diabetic nephropathy. Th17 immune cells and their effector cytokine IL-17A have recently emerged as promising targets in several clinical conditions, including renal diseases. Here, we review current knowledge regarding the involvement of Th17/IL-17A in the genesis of diabetic renal...

Research paper thumbnail of Interleukin-17A blockade reduces albuminuria and kidney injury in an accelerated model of diabetic nephropathy

Kidney International

Some clinical trials blocking IL-17A have proven beneficial effects in chronic inflammatory disea... more Some clinical trials blocking IL-17A have proven beneficial effects in chronic inflammatory diseases. Novel therapeutic options to prevent renal damage clinically are unmet for diabetic nephropathy (DN). Our preclinical data suggest that treatment with neutralizing IL-17A antibodies could be a therapeutic option for diabetic patients with albuminuria.

Research paper thumbnail of FP448TUBULAR Overexpression of Gremlin in Transgenic Mice Aggravates Renal Damage in Diabetic Nephropathy

Nephrology Dialysis Transplantation, 2015

Research paper thumbnail of Correction: Tubular Overexpression of Gremlin Induces Renal Damage Susceptibility in Mice

Research paper thumbnail of Tubular NF-κB and AP1 activation in human proteinuric renal disease

Kidney International - KIDNEY INT, 2001

Tubular NF-κB and AP-1 activation in human proteinuric renal disease.BackgroundNuclear factor-κB ... more Tubular NF-κB and AP-1 activation in human proteinuric renal disease.BackgroundNuclear factor-κB (NF-κB) and activated protein-1 (AP-1) are transcription factors that regulate many genes involved in the progression of renal disease. Recent data have shown that NF-κB is activated in tubules and glomeruli in various experimental models of renal injury. In vitro studies also suggest that proteinuria could be an important NF-κB activator. We therefore approached the idea that NF-κB may be an indicator of renal damage progression.MethodsParaffin-embedded renal biopsy specimens from 34 patients with intense proteinuria [14 with minimal change disease (MCD) and 20 with idiopathic membranous nephropathy (MN)] and from 7 patients with minimal or no proteinuria (IgA nephropathy) were studied by Southwestern histochemistry for the in situ detection of activated transcription factors NF-κB and AP-1. In addition, by immunohistochemistry, we performed staining for the NF-κB subunits (p50 and p65)...

Research paper thumbnail of Overexpression of chemokines, fibrogenic cytokines, and myofibroblasts in human membranous nephropathy

Kidney …, 2000

Kidney International aims to inform the renal researcher and practicing nephrologists on all aspe... more Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published ...

Research paper thumbnail of Gremlin and renal diseases: ready to jump the fence to clinical utility?

Nephrology Dialysis Transplantation

Adherence to the Mediterranean diet is associated with reduced risk of incident chronic kidney di... more Adherence to the Mediterranean diet is associated with reduced risk of incident chronic kidney diseases among Tehranian adults.

Research paper thumbnail of NF B activation and overexpression of regulated genes in human diabetic nephropathy

Nephrology Dialysis Transplantation - NEPHROL DIALYSIS TRANSPLANT, 2004

Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such... more Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such as the chemokines monocyte chemoattractant protein-1 (MCP-1) and RANTES. NF-kB is activated in experimental models of renal injury, and in vitro studies also suggest that proteinuria and angiotensin II could be important NF-kB activators. It has been proposed that locally produced MCP-1 may be involved in the development of diabetic nephropathy (DN). We examined the hypothesis that NF-kB could be an indicator of renal damage progression in DN. Methods. Biopsy specimens from 11 patients with type 2 diabeties and overt nephropathy were studied by southwestern histochemistry for the in situ detection of activated NF-kB. In addition, by immunohistochemistry and/or in situ hybridization, we studied the expression of MCP-1 and RANTES, whose genes are regulated by NF-kB. Results. NF-kB was detected mainly in cortical tubular epithelial cells and, to a lesser extent, in some glomerular and interstitial cells. A strong upregulation of MCP-1 and RANTES was observed in all the cases, mainly in tubular cells, and there was a strong correlation between the expression of these chemokines and NF-kB activation in the same cells, as observed in serial sections (r ¼ 0.7; P ¼ 0.01). In addition, the tubular expression of these chemokines was correlated mainly with the magnitude of the proteinuria (P ¼ 0.002) and with interstitial cell infiltration (P<0.05). Conclusions. The activation of NF-kB and the transcription of certain pro-inflammatory chemokines in tubular epithelial cells are markers of progressive DN. Proteinuria might be one of the main factors inducing the observed pro-inflammatory phenotype.

Research paper thumbnail of Gremlin: A novel mediator of epithelial mesenchymal transition and fibrosis in chronic allograft nephropathy

Transplantation Proceedings, 2008

Background. Chronic allograft nephropathy (CAN) is the most frequent cause of chronic dysfunction... more Background. Chronic allograft nephropathy (CAN) is the most frequent cause of chronic dysfunction and late loss of renal allografts. Epithelial mesenchymal transition (EMT) has been identified as responsible for the presence of activated interstitial fibroblasts (myofibroblasts) and transforming growth factor beta (TGF-␤)/Smad is the key signaling mediator. It has been proposed that the bone morphogenetic protein 7 (BMP-7) antagonist, Gremlin, could participate in EMT, as a downstream mediator of TGF-␤. Methods. We evaluated 33 renal allograft biopsies, 16 of which showed CAN, versus 17 controls. By in situ hybridization we studied the expression of TGF-␤ and Gremlin mRNA. Gremlin, BMP-7, E-cadherin, and ␣-smooth muscle actin (␣-SMA) proteins were evaluated by immunohistochemistry and Smad3 activation by Southwestern. In cultured human tubuloepithelial cells (HK2 cell line), Gremlin induction by TGF-␤ was studied by confocal microscopy. Results. Among renal biopsies of transplanted patients with CAN, we detected upregulation of TGF-␤ in colocalization with Gremlin (RNA and protein), mainly in areas of tubulointerstitial fibrosis. In the same tubules, we observed decreased expression of E-cadherin and induction of vimentin and ␣-SMA. BMP-7 was significantly decreased in the CAN biopsies. In addition, HK2 stimulated with TGF-␤ (1 ng/mL) induced Gremlin production at 72 hours. Conclusion. We postulated that Gremlin is a downstream mediator of TGF-␤, suggesting a role for Gremlin in EMT observed in CAN.

Research paper thumbnail of Translational study of the Notch pathway in hypertensive nephropathy

Nefrología : publicación oficial de la Sociedad Española Nefrologia, Jan 21, 2014

The Notch signalling pathway is activated in a wide variety of human renal diseases. We have rece... more The Notch signalling pathway is activated in a wide variety of human renal diseases. We have recently demonstrated that the activation of this pathway is not involved in experimental renal fibrosis induced by angiotensin II or hypertension. To assess whether the Notch pathway is activated in renal fibrosis related to hypertensive nephrosclerosis. To test the hypothesis, various glomerular diseases characterised by tubulointerstitial fibrosis were analysed. Renal biopsies were performed on patients with hypertensive nephrosclerosis, in comparison with diabetic nephropathy and membranous nephropathy at various stages. Gene and protein expression were evaluated by in-situ hybridisation and immunohistochemistry respectively. In hypertensive nephrosclerosis low renal expression of notch-related proteins was observed. There was no link between tubulointerstitial fibrosis and the levels of these proteins. By contrast, in the glomerular diseases studied we observed high expression of the tr...

Research paper thumbnail of Expression of gremlin, a bone morphogenetic protein antagonist, in glomerular crescents of pauci-immune glomerulonephritis

Background. Recent evidence in vitro and in vivo suggests that gremlin, a bone morphogenetic prot... more Background. Recent evidence in vitro and in vivo suggests that gremlin, a bone morphogenetic protein antagonist, is participating in tubular epithelial mesenchymal transition (EMT) in diabetic nephropa- thy as a downstream mediator of TGF-b. Since EMT also occurs in parietal epithelial glomerular cells (PECs) leading to crescent formation, we hypothesized that gremlin could participate in this process. With this aim

Research paper thumbnail of Gremlin Activates the Smad Pathway Linked to Epithelial Mesenchymal Transdifferentiation in Cultured Tubular Epithelial Cells

BioMed Research International, 2014

Research paper thumbnail of Tubular Overexpression of Gremlin Induces Renal Damage Susceptibility in Mice

PLoS ONE, 2014

A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular ... more A growing number of patients are recognized worldwide to have chronic kidney disease. Glomerular and interstitial fibrosis are hallmarks of renal progression. However, fibrosis of the kidney remains an unresolved challenge, and its molecular mechanisms are still not fully understood. Gremlin is an embryogenic gene that has been shown to play a key role in nephrogenesis, and its expression is generally low in the normal adult kidney. However, gremlin expression is elevated in many human renal diseases, including diabetic nephropathy, pauci-immune glomerulonephritis and chronic allograft nephropathy. Several studies have proposed that gremlin may be involved in renal damage by acting as a downstream mediator of TGF-b. To examine the in vivo role of gremlin in kidney pathophysiology, we generated seven viable transgenic mouse lines expressing human gremlin (GREM1) specifically in renal proximal tubular epithelial cells under the control of an androgen-regulated promoter. These lines demonstrated 1.2-to 200-fold increased GREM1 expression. GREM1 transgenic mice presented a normal phenotype and were without proteinuria and renal function involvement. In response to the acute renal damage cause by folic acid nephrotoxicity, tubule-specific GREM1 transgenic mice developed increased proteinuria after 7 and 14 days compared with wild-type treated mice. At 14 days tubular lesions, such as dilatation, epithelium flattening and hyaline casts, with interstitial cell infiltration and mild fibrosis were significantly more prominent in transgenic mice than wild-type mice. Tubular GREM1 overexpression was correlated with the renal upregulation of profibrotic factors, such as TGF-b and aSMA, and with increased numbers of monocytes/macrophages and lymphocytes compared to wild-type mice. Taken together, our results suggest that GREM1-overexpressing mice have an increased susceptibility to renal damage, supporting the involvement of gremlin in renal damage progression. This transgenic mouse model could be used as a new tool for enhancing the knowledge of renal disease progression.

Research paper thumbnail of NF-kB activation and overexpression of regulated genes in human diabetic nephropathy

Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such... more Background. Nuclear factor-kB (NF-kB) regulates genes involved in renal disease progression, such as the chemokines monocyte chemoattractant protein-1 (MCP-1) and RANTES. NF-kB is activated in experimental models of renal injury, and in vitro studies also suggest that proteinuria and angiotensin II could be important NF-kB activators. It has been proposed that locally produced MCP-1 may be involved in the development