scholarly journals Renal SGLT mRNA expression in human health and disease: a study in two cohorts

2019 ◽  
Vol 317 (5) ◽  
pp. F1224-F1230
Author(s):  
Vikas Srinivasan Sridhar ◽  
Jaya Prakash N. Ambinathan ◽  
Matthias Kretzler ◽  
Laura L. Pyle ◽  
Petter Bjornstad ◽  
...  

Pharmacological Na+-glucose linked cotransporter (SGLT)2 inhibition is being examined as a renal protection strategy in nondiabetic chronic kidney disease. We quantified renal SGLT mRNA expression in healthy controls (HC), glomerulonephritis (GN), and diabetic kidney disease (DKD) to identify differences in expression across a spectrum of renal diseases. mRNA expression of SGLT1 and SGLT2 in renal tubules and glomeruli, obtained using microdissection and microarray techniques, was evaluated in two large cohorts. The European Renal cDNA bank included HC, GN, and DKD (98 glomeruli and 93 tubulointerstitium). The Nephrotic Syndrome Study Network cohort included 124 adults with membranous nephropathy, minimal change disease, focal segmental glomerulosclerosis, and IgA nephropathy. Within the European Renal cDNA bank, SGLT2 tubular and glomerular log2 mRNA expression significantly differed across HC, GN, and DKD ( P = 0.0009 and P = 0.0004), with the highest expression in HC. Within the Nephrotic Syndrome Study Network, there were no differences in SGLT log2 mRNA expression across GN subtypes. Tubular SGLT2 log2 mRNA expression positively correlated with estimated glomerular filtration rate (by the Modification of Diet in Renal Disease Study equation) and glycated hemoglobin ( r = 0.33 and 0.34, P < 0.05) and inversely correlated with interstitial fibrosis ( r = −0.21, P < 0.05). In conclusion, SGLT2 mRNA expression was lower in DKD compared with HC or GN and inversely related to interstitial fibrosis. The relationships between SGLT mRNA, protein expression, and transporter activity require further elucidation.

2021 ◽  
Vol 10 (10) ◽  
pp. 2046
Author(s):  
Goren Saenz-Pipaon ◽  
Saioa Echeverria ◽  
Josune Orbe ◽  
Carmen Roncal

Diabetic kidney disease (DKD) is the leading cause of end stage renal disease (ESRD) in developed countries, affecting more than 40% of diabetes mellitus (DM) patients. DKD pathogenesis is multifactorial leading to a clinical presentation characterized by proteinuria, hypertension, and a gradual reduction in kidney function, accompanied by a high incidence of cardiovascular (CV) events and mortality. Unlike other diabetes-related complications, DKD prevalence has failed to decline over the past 30 years, becoming a growing socioeconomic burden. Treatments controlling glucose levels, albuminuria and blood pressure may slow down DKD evolution and reduce CV events, but are not able to completely halt its progression. Moreover, one in five patients with diabetes develop DKD in the absence of albuminuria, and in others nephropathy goes unrecognized at the time of diagnosis, urging to find novel noninvasive and more precise early diagnosis and prognosis biomarkers and therapeutic targets for these patient subgroups. Extracellular vesicles (EVs), especially urinary (u)EVs, have emerged as an alternative for this purpose, as changes in their numbers and composition have been reported in clinical conditions involving DM and renal diseases. In this review, we will summarize the current knowledge on the role of (u)EVs in DKD.


The Lancet ◽  
2011 ◽  
Vol 377 (9784) ◽  
pp. 2181-2192 ◽  
Author(s):  
Colin Baigent ◽  
Martin J Landray ◽  
Christina Reith ◽  
Jonathan Emberson ◽  
David C Wheeler ◽  
...  

Author(s):  
Komuraiah Myakala ◽  
Bryce Jones ◽  
Xiaoxin Wang ◽  
Moshe Levi

Although renin-angiotensin blockade has shown the beneficial outcomes in patients with diabetes, renal injury progresses in most of these patients. Therefore, there remains a need for new therapeutic targets in diabetic kidney disease. Enhancement of vasoactive peptides, such as natriuretic peptides, via neprilysin inhibition, has been a new approach. A first-in-class drug sacubitril/valsartan (Sac/Val), a combination of angiotensin II receptor blocker valsartan and neprilysin inhibitor prodrug sacubitril, has been shown more effective than renin-angiotensin blockade alone in the treatment of heart failure with reduced ejection fraction. In this study we tested the effects of Sac/Val in the diabetic kidney disease. We administered Sac/Val or valsartan to two type 2 diabetes mouse models, db/db mice or KKAy mice. After 3-month treatment, Sac/Val attenuated the progression of proteinuria, glomerulosclerosis, and podocyte loss in both models of diabetic mice. Valsartan shared the similar improvement but to a lesser degree in some parameters compared to Sac/Val. Sac/Val but not valsartan decreased the blood glucose level in KKAy mice. Sac/Val exerted renal protection through coordinated effects on anti-oxidative stress and anti-inflammation. In both diabetic models, we revealed a new mechanism to cause inflammation, self DNA activated cGAS-STING signaling, which was activated in diabetic kidneys and prevented by Sac/Val or valsartan treatment. Present data suggest that Sac/Val has sufficient therapeutical potential to counter the pathophysiological effects of diabetic kidney disease and its effectiveness could be better than valsartan alone.


2020 ◽  
Vol 21 (8) ◽  
pp. 2951 ◽  
Author(s):  
Masahiro Nezu ◽  
Norio Suzuki

Over 10% of the global population suffers from kidney disease. However, only kidney replacement therapies, which burden medical expenses, are currently effective in treating kidney disease. Therefore, elucidating the complicated molecular pathology of kidney disease is an urgent priority for developing innovative therapeutics for kidney disease. Recent studies demonstrated that intertwined renal vasculature often causes ischemia-reperfusion injury (IRI), which generates oxidative stress, and that the accumulation of oxidative stress is a common pathway underlying various types of kidney disease. We reported that activating the antioxidative transcription factor Nrf2 in renal tubules in mice with renal IRI effectively mitigates tubular damage and interstitial fibrosis by inducing the expression of genes related to cytoprotection against oxidative stress. Additionally, since the kidney performs multiple functions beyond blood purification, renoprotection by Nrf2 activation is anticipated to lead to various benefits. Indeed, our experiments indicated the possibility that Nrf2 activation mitigates anemia, which is caused by impaired production of the erythroid growth factor erythropoietin from injured kidneys, and moderates organ damage worsened by anemic hypoxia. Clinical trials investigating Nrf2-activating compounds in kidney disease patients are ongoing, and beneficial effects are being obtained. Thus, Nrf2 activators are expected to emerge as first-in-class innovative medicine for kidney disease treatment.


Author(s):  
Yu Ho Lee ◽  
Ki Pyo Kim ◽  
Sun-Hwa Park ◽  
Dong-Jin Kim ◽  
Yang-Gyun Kim ◽  
...  

Abstract Background Interstitial fibrosis and tubular atrophy (IFTA) is a well-recognized risk factor for poor renal outcome in patients with diabetic kidney disease (DKD). However, a noninvasive biomarker for IFTA is currently lacking. The purpose of this study was to identify urinary markers of IFTA and to determine their clinical relevance as predictors of renal prognosis. Methods Seventy patients with biopsy-proven isolated DKD were enrolled in this study. We measured multiple urinary inflammatory cytokines and chemokines by multiplex enzyme-linked immunosorbent assay in these patients and evaluated their association with various pathologic features and renal outcomes. Results Patients enrolled in this study exhibited advanced DKD at the time of renal biopsy, characterized by moderate to severe renal dysfunction [mean estimated glomerular filtration rate (eGFR) 36.1 mL/min/1.73 m2] and heavy proteinuria (mean urinary protein:creatinine ratio 7.8 g/g creatinine). Clinicopathologic analysis revealed that higher IFTA scores were associated with worse baseline eGFR (P < 0.001) and poor renal outcome (P = 0.002), whereas glomerular injury scores were not. Among measured urinary inflammatory markers, C-X-C motif ligand 16 (CXCL16) and endostatin showed strong correlations with IFTA scores (P = 0.001 and P < 0.001, respectively), and patients with higher levels of urinary CXCL16 and/or endostatin experienced significantly rapid renal progression compared with other patients (P < 0.001). Finally, increased urinary CXCL16 and endostatin were independent risk factors for poor renal outcome after multivariate adjustments (95% confidence interval 1.070–3.455, P = 0.029). Conclusions Urinary CXCL16 and endostatin could reflect the degree of IFTA and serve as biomarkers of renal outcome in patients with advanced DKD.


Toxins ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 367 ◽  
Author(s):  
Wen-Chih Liu ◽  
Yasuhiko Tomino ◽  
Kuo-Cheng Lu

Uremic toxins, such as indoxyl sulfate (IS) and p-cresol, or p-cresyl sulfate (PCS), are markedly accumulated in the organs of chronic kidney disease (CKD) patients. These toxins can induce inflammatory reactions and enhance oxidative stress, prompting glomerular sclerosis and interstitial fibrosis, to aggravate the decline of renal function. Consequently, uremic toxins play an important role in the worsening of renal and cardiovascular functions. Furthermore, they destroy the quantity and quality of bone. Oral sorbent AST-120 reduces serum levels of uremic toxins in CKD patients by adsorbing the precursors of IS and PCS generated by amino acid metabolism in the intestine. Accordingly, AST-120 decreases the serum IS levels and reduces the production of reactive oxygen species by endothelial cells, to impede the subsequent oxidative stress. This slows the progression of cardiovascular and renal diseases and improves bone metabolism in CKD patients. Although large-scale studies showed no obvious benefits from adding AST-120 to the standard therapy for CKD patients, subsequent sporadic studies may support its use. This article summarizes the mechanisms of the uremic toxins, IS, and PCS, and discusses the multiple effects of AST-120 in CKD patients.


2001 ◽  
Vol 281 (3) ◽  
pp. F513-F521 ◽  
Author(s):  
Kyoichi Fukuda ◽  
Koji Yoshitomi ◽  
Taihei Yanagida ◽  
Masanori Tokumoto ◽  
Hideki Hirakata

Unilateral ureteral obstruction (UUO) leads to interstitial fibrosis of the obstructed kidney, and transforming growth factor-β1 (TGF-β1) is thought to play an important role in this process. Although increased TGF-β1 mRNA expression in the obstructed kidney has been demonstrated, the source of the increased TGF-β1 remains to be elucidated. To determine the precise localization of TGF-β1 in the obstructed kidney, we examined TGF-β1 mRNA expression using in situ hybridization and competitive RT-PCR in rats with UUO. In situ hybridization demonstrated that TGF-β1 mRNA expression was preferentially increased in tubular epithelial cells and to a lesser degree in infiltrating macrophages in obstructed kidneys. Quantitative analysis using competitive RT-PCR in microdissected nephron segments revealed that levels of TGF-β1 mRNA in obstructed kidneys relative to control kidneys increased significantly in proximal tubules, thick ascending limbs of Henle, and distal convoluted tubules, whereas those in glomeruli and collecting ducts did not change significantly. Of the tubular segments, the proximal tubules appeared to predominantly contribute to increased TGF-β1 mRNA. Our findings suggest that renal tubules, particularly proximal tubules, are the main contributors to increased TGF-β1 mRNA expression in obstructed kidneys and to the subsequent interstitial fibrosis.


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