scholarly journals Telocinobufagin, a Novel Cardiotonic Steroid, Promotes Renal Fibrosis via Na+/K+-ATPase Profibrotic Signaling Pathways

2018 ◽  
Vol 19 (9) ◽  
pp. 2566 ◽  
Author(s):  
David Kennedy ◽  
Fatimah Khalaf ◽  
Brendan Sheehy ◽  
Malory Weber ◽  
Brendan Agatisa-Boyle ◽  
...  

Cardiotonic steroids (CTS) are Na+/K+-ATPase (NKA) ligands that are elevated in volume-expanded states and associated with cardiac and renal dysfunction in both clinical and experimental settings. We test the hypothesis that the CTS telocinobufagin (TCB) promotes renal dysfunction in a process involving signaling through the NKA α-1 in the following studies. First, we infuse TCB (4 weeks at 0.1 µg/g/day) or a vehicle into mice expressing wild-type (WT) NKA α-1, as well as mice with a genetic reduction (~40%) of NKA α-1 (NKA α-1+/−). Continuous TCB infusion results in increased proteinuria and cystatin C in WT mice which are significantly attenuated in NKA α-1+/− mice (all p < 0.05), despite similar increases in blood pressure. In a series of in vitro experiments, 24-h treatment of HK2 renal proximal tubular cells with TCB results in significant dose-dependent increases in both Collagens 1 and 3 mRNA (2-fold increases at 10 nM, 5-fold increases at 100 nM, p < 0.05). Similar effects are seen in primary human renal mesangial cells. TCB treatment (100 nM) of SYF fibroblasts reconstituted with cSrc results in a 1.5-fold increase in Collagens 1 and 3 mRNA (p < 0.05), as well as increases in both Transforming Growth factor beta (TGFb, 1.5 fold, p < 0.05) and Connective Tissue Growth Factor (CTGF, 2 fold, p < 0.05), while these effects are absent in SYF cells without Src kinase. In a patient study of subjects with chronic kidney disease, TCB is elevated compared to healthy volunteers. These studies suggest that the pro-fibrotic effects of TCB in the kidney are mediated though the NKA-Src kinase signaling pathway and may have relevance to volume-overloaded conditions, such as chronic kidney disease where TCB is elevated.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
David J Kennedy ◽  
Malory E Weber ◽  
Anuradha Guggilam ◽  
Kristen M Westfall ◽  
Brendan Agatisa-Boyle ◽  
...  

Cardiotonic steroids (CTS) are Na/K-ATPase (NKA) ligands that are elevated in volume-expanded states and associated with cardiac and renal dysfunction in both clinical and experimental settings. We recently discovered significantly elevated levels of a novel CTS, telocinobufagin (TCB), in patients with heart failure. We tested the hypothesis that TCB promotes cardiac and renal dysfunction in a process involving signaling through the NKA-α-1 in the following studies. First, we infused TCB (4 weeks at 10 ug/Kg/day) or vehicle into mice expressing wild type NKA-α-1 (WT), as well as mice with a genetic reduction of NKA-α-1 (NKA+/-) or transgenic human NKA-α-1 (NKA-Tg), which renders them more sensitive to CTS. TCB infusion resulted in impairment of cardiac structure (36% increase in heart weight/body weight ratio, 18% increase in diastolic Left Ventricular Internal Dimension vs. vehicle, p<0.05) in WT mice which was significantly attenuated in NKA+/- mice. TCB infusion also resulted increased proteinuria and cystatin C in WT mice which was significantly attenuated in NKA+/- mice (all p<0.05) despite similar increases in blood pressure. In NKA-Tg mice, TCB infusion resulted in increased myocardial (Fig 1A) and renal (Fig 1B) fibrosis vs. WT (all p<0.05). In a series of in vitro experiments, 24 hour treatment of HK2 renal proximal tubular cells with TCB resulted in significant dose dependent increases in both Collagen 1 and 3 mRNA (2 fold increases at 10 nM, 5 fold increases at 100 nM, p<0.05). TCB treatment (100 nM) of SYF fibroblasts reconstituted with cSrc resulted in a 1.5 fold increase in Collagen 1 and 3 mRNA (p<0.05) as well as increases in both Transforming Growth factor beta (TGFb, 1.5 fold, p<0.05) and Connective Tissue Growth Factor (CTGF, 2 fold, p<0.05), while these effects were absent in SYF cells without Src kinase. These studies suggest that the pro-fibrotic effects of TCB are mediated though the NKA-Src kinase signaling pathway.


2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Chenglei Zhao ◽  
Sean T. Zuckerman ◽  
Chuanqi Cai ◽  
Sreenivasulu Kilari ◽  
Avishek Singh ◽  
...  

Background Venous neointimal hyperplasia and venous stenosis (VS) formation can result in a decrease in arteriovenous fistula (AVF) patency in patients with end‐stage renal disease. There are limited therapies that prevent VNH/VS. Systemic delivery of simvastatin has been shown to reduce VNH/VS but local delivery may help decrease the side effects associated with statin use. We determined if microparticles (MP) composed of cyclodextrins loaded with simvastatin (MP‐SV) could reduce VS/VNH using a murine arteriovenous fistula model with chronic kidney disease. Methods and Results Male C57BL/6J mice underwent nephrectomy to induce chronic kidney disease. Four weeks later, an arteriovenous fistula was placed and animals were randomized to 3 groups: 20 μL of PBS or 20 μL of PBS with 16.6 mg/mL of either MP or MP‐SV. Animals were euthanized 3 days later and the outflow veins were harvested for quantitative reverse transcriptase–polymerase chain reaction analysis and 28 days later for immunohistochemistical staining with morphometric analysis. Doppler ultrasound was performed weekly. Gene expression of vascular endothelial growth factor‐A ( Vegf‐A ), matrix metalloproteinase‐9 ( Mmp‐9 ), transforming growth factor beta 1 ( Tgf‐β1 ), and monocyte chemoattractant protein‐1 ( Mcp‐1 ) were significantly decreased in MP‐SV treated vessels compared with controls. There was a significant decrease in the neointimal area, cell proliferation, inflammation, and fibrosis, with an increase in apoptosis and peak velocity in MP‐SV treated outflow veins. MP‐SV treated fibroblasts when exposed to hypoxic injury had decreased gene expression of Vegf‐A and Mmp‐9 . Conclusions In experimental arteriovenous fistulas, periadventitial delivery of MP‐SV decreased gene expression of Vegf‐A , Mmp‐9 , Tgf‐β1 and Mcp‐1, VNH/VS, inflammation, and fibrosis.


2020 ◽  
pp. 1098612X2093575
Author(s):  
Kate KuKanich ◽  
Christopher George ◽  
James K Roush ◽  
Sherry Sharp ◽  
Giosi Farace ◽  
...  

Objectives Meloxicam therapy may benefit cats with degenerative joint disease, and retrospective studies suggest it could slow kidney disease progression and increase survival. This study aimed to prospectively evaluate the renal effects of low-dose meloxicam treatment (0.02 mg/kg/day) over 6 months in cats with chronic kidney disease (CKD). Methods Twenty-one cats with stable International Renal Interest Society stage 2 or 3 CKD were recruited and randomized to placebo or meloxicam groups. Cats were evaluated at baseline and at 1, 3 and 6 months, including blood pressure, chemistry, symmetric dimethylarginine (SDMA), glomerular filtration rate (GFR), urinalysis, urine protein:creatinine ratio (UPC), urine transforming growth factor-beta (ß):creatinine ratio, urine clusterin, urine cystatin B and serum inosine. Results No statistical difference was observed in systolic blood pressure, blood urea nitrogen, creatinine, SDMA, GFR, urine transforming growth factor-ß:creatinine ratio, urine clusterin, urine cystatin B or serum inosine in cats receiving meloxicam vs placebo. Mean UPC was greater in the meloxicam group (0.33) than the placebo group (0.1) at 6 months ( P = 0.006). Four cats had meloxicam discontinued owing to potential (mainly gastrointestinal) adverse effects. Conclusions and relevance No decline in renal excretory function was observed when meloxicam was administered to cats with CKD. However, gastrointestinal adverse effects were observed, and cats that received meloxicam had greater proteinuria at 6 months than cats that received placebo. As proteinuria is associated with negative outcomes (progression of azotemia and hypertension) in cats with CKD, this finding suggests that meloxicam should be used with caution in cats with CKD and UPC monitored. Until further research is available, clinicians should weigh the risk of potential increased proteinuria against quality of life benefits when considering meloxicam for analgesia in cats with renal disease.


2004 ◽  
Vol 286 (1) ◽  
pp. F134-F143 ◽  
Author(s):  
Shinya Mizuno ◽  
Toshikazu Nakamura

Diabetic nephropathy is now the leading cause of end-stage renal diseases, and glomerular sclerotic injury is an initial event that provokes renal dysfunction during processes of diabetes-linked kidney disease. Growing evidence shows that transforming growth factor-β1 (TGF-β1) plays a key role in this process, especially in eliciting hypertrophy and matrix overaccumulation. Thus it is important to find a ligand system to antagonize the TGF-β1-mediated pathogenesis under high-glucose conditions. Herein, we provide evidence that hepatocyte growth factor (HGF) targets mesangial cells, suppresses TGF-β1 production, and minimizes glomerular sclerotic changes, using streptozotocin-induced diabetic mice. In our murine model, glomerular sclerogenesis (such as tuft area expansion and collagen deposition) progressed between 6 and 10 wk after the induction of hyperglycemia, during a natural course of diabetic disease. Glomerular HGF expression levels in the diabetic kidney transiently increased but then declined below a basal level, with manifestation of glomerular sclerogenesis. When anti-HGF IgG was injected into mice for 2 wk (i.e., from weeks 4 to 6 after onset of hyperglycemia), these glomerular changes were significantly aggravated. When recombinant HGF was injected into the mice for 4 wk (i.e., between 6 and 10 wk following streptozotocin treatment), the progression of glomerular hypertrophy and sclerosis was almost completely inhibited, even though glucose levels remained unchanged (>500 mg/dl). Even more important, HGF repressed TGF-β1 production in glomerular mesangial cells even under hyperglycemic conditions both in vitro and in vivo. Consequently, not only albuminuria but also tubulointerstitial fibrogenesis were attenuated by HGF. Overall, HGF therapy inhibited the onset of renal dysfunction in the diabetic mice. On the basis of these findings, we wish to emphasize that HGF plays physiological and therapeutic roles in blocking renal fibrogenesis during a course of diabetic nephropathy.


2017 ◽  
Vol 204 (3-4) ◽  
pp. 191-198 ◽  
Author(s):  
Gemma A. Figtree ◽  
Kristen J. Bubb ◽  
Owen Tang ◽  
Eddy Kizana ◽  
Carmine Gentile

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.


2016 ◽  
Vol 14 (1) ◽  
pp. 8-10 ◽  
Author(s):  
Ingrid Prkacin ◽  
Gordana Cavric ◽  
Nikolina Basic-Jukic

AbstractClinical and laboratory findings of kidney disease in an adult may find an explanation in kidney functional and/or structural abnormalities that already existed during infancy and childhood, but that may have been missed or underdiagnosed. All the cardiovascular abnormalities that occur in adults with chronic kidney disease are also present in children with chronic kidney disease. Complications in childhood chronic kidney disease will have consequences well beyond pediatric age and influence outcomes of affected young adults with disease. Kidney dysfunction appears early in the course of kidney disease and has been observed in children and adults with chronic kidney disease, condition characterised with kidney fibrosis. Transforming growth factor beta is recognized as a major mediator of kidney fibrosis. New evidence illustrates the relationship between transforming growth factor beta signaling and microRNAs expression during kidney diseases development. MicroRNAs play important roles in kidney development and kidney diseases; they are naturally occurring, 22-nucleotide, noncoding RNAs that mediate posttranscriptional gene regulation. Dysregulation of miRNA expression is an indicator of several diseases including chronic kidney disease. Targeting microRNAs should be a therapeutic potential to ameliorate the disease related to fibrosis. The discovery that circulating miRNAs are detectable in serum and plasma, and that their expression varies as a result of disease, presents great potential to be used as biomarkers in kidney disease prevention and diagnosis.


2017 ◽  
Vol 45 (3) ◽  
pp. 226-234 ◽  
Author(s):  
David Langsford ◽  
Mila Tang ◽  
Hicham I. Cheikh Hassan ◽  
Ognjenka Djurdjev ◽  
Manish M. Sood ◽  
...  

Background: Prognosis in chronic kidney disease (CKD) for adverse outcomes differs substantially based on the etiology of CKD. We examined whether the biomarker profile differed based on CKD etiology and whether they were associated with mortality. Methods: Prospective observational study of 1,157 patients, 663 with diabetic kidney disease (DKD), 273 with glomerulonephritis (GN), and 221 with cystic/interstitial disease (polycystic kidney disease, pyelonephritis or chronic tubulointerstitial nephritis [PCK/TIN]) were identified in the Canadian Study of Prediction of Dialysis, Death and Interim Cardiovascular events over Time cohort. The outcome of interest was mortality before commencing dialysis. The biomarker profile consisted of N-terminal pro-brain natriuretic peptide (NT-proBNP), troponin I (TnI), asymmetric dimethylarginine (ADMA), interleukin (IL)-6, high sensitivity C-reactive protein, fibroblast growth factor-23 (FGF23), transforming growth factor-beta, 25-hydroxylvitamin D, and cystatin C (CysC). Results: The mean estimated glomerular filtration rate was 27 mL/min/1.73 m2 and median follow-up time was 44 months. Mortality before dialysis commencement was the greatest in DKD (20%), followed by PCK/TIN (13%), and was least in those GN (8%). The majority of deaths were cardiovascular in nature, 17, 9, and 5.5% for DKD, PCK/TIN, GN, respectively. Those with DKD had higher hazard for mortality, unadjusted (hazard ratio [HR] 2.7, 95% CI 1.7-4.3) and adjusted (HR 1.7, 95% CI 1.1-2.8). The biomarker profiles associated with mortality differed significantly by CKD etiology as follows: DKD was associated with CysC (HR 1.3, 95% CI 1.0-1.6), ADMA (HR 1.3, 95% CI 1.1-1.6), and NT-proBNP (HR 1.7, 95% CI 1.4-2.1), GN was associated with FGF23 (HR 1.8, 95% CI 1.1-2.8), TnI (HR 3.6, 95% CI 1.3-9.5), and transforming growth factor-beta (HR 0.6, 95% CI 0.4-0.9) and PCK/TIN was associated with ADMA (HR 1.5, 95% CI 1.3-1.8) and IL-6 (HR 2.1, 95% CI 1.5-3.1). Conclusions: Biomarkers profiles differ according to the etiology of CKD and are associated with mortality.


2019 ◽  
Vol 24 (3) ◽  
pp. 160
Author(s):  
Sijani Prahastuti ◽  
Meilinah Hidayat ◽  
Stella Tinia Hasiana ◽  
Wahyu Widowati ◽  
Annisa Amalia ◽  
...  

Chronic Kidney Disease (CKD) has increased incidence and prevalence in developing nations. In this in vitro study, we evaluated the cells proliferative effects, fibronectin (FN), transforming growth factor β (TGF-β1), and Reactive oxygen species (ROS) - level inhibition potential of ethanol extract of detam 1 soybean seed (EEDS) on glucose-induced kidney mesangial cells (SV40 MES 13). The cells proliferation assay used 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium (MTS) assay. FN and TGF-β1 level were measured using ELISA assay kit and ROS level using flow cytometry. Level of   FN, TGF-β1 and ROS, on CKD cells model (5 mM, 10 mM glucose-induced mesangial cell) treated with EEDS 6.25 µg/mL were lower significantly compared to positive control,  EEDS improve cells viability and decrease FN, TGF-β1 and ROS level in glucose-induced kidney mesangial cells as CKD cells model.


2007 ◽  
Vol 293 (5) ◽  
pp. F1468-F1475 ◽  
Author(s):  
Jie Xu ◽  
Bing Yao ◽  
Xiaofeng Fan ◽  
Melissa M. Langworthy ◽  
Ming-Zhi Zhang ◽  
...  

Serotonin [5-hydroxytryptamine (5HT)] acts through multiple G protein-coupled 5-HT receptors, and its activity is also regulated by the 5-HT transporter. The current studies report the expression and localization of the 5-HT receptors and transporter in the kidney. In addition, the enzymatic pathway mediating 5-HT synthesis is present in renal cortex, especially in the proximal tubules and glomerular epithelial cells and mesangial cells. Expression of the 5-HT receptors and 5-HT transporter was detected by RT-PCR in cell lines of these cell types. In cultured proximal tubule cells and podocytes, 5-HT activated ERK1/2 and increased the expression of connective tissue growth factor and transforming growth factor-β, two key mediators of extracellular matrix accumulation. Immunohistochemistry and real-time RT-PCR studies also indicated that 5-HT stimulated expression of vascular endothelial growth factor in podocytes in vitro and in vivo. Therefore, these results indicate the presence of an integrated intrarenal serotonergic system and suggest a possible role for 5-HT as a mediator of renal fibrosis in the kidney.


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