scholarly journals Therapeutic Targeting of Aristolochic Acid Induced Uremic Toxin Retention, SMAD 2/3 and JNK/ERK Pathways in Tubulointerstitial Fibrosis: Nephroprotective Role of Propolis in Chronic Kidney Disease

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 364
Author(s):  
Jia-Feng Chang ◽  
Chih-Yu Hsieh ◽  
Kuo-Cheng Lu ◽  
Yue-Wen Chen ◽  
Shih-Shin Liang ◽  
...  

The nephrotoxicity of aristolochic acids (AAs), p-cresyl sulfate (PCS) and indoxyl sulfate (IS) were well-documented, culminating in tubulointerstitial fibrosis (TIF), advanced chronic kidney disease (CKD) and fatal urothelial cancer. Nonetheless, information regarding the attenuation of AAs-induced nephropathy (AAN) and uremic toxin retention is scarce. Propolis is a versatile natural product, exerting anti-oxidant, anti-cancer and anti-fibrotic properties. We aimed to evaluate nephroprotective effects of propolis extract (PE) in a murine model. AAN was developed to retain circulating PCS and IS using C57BL/6 mice, mimicking human CKD. The kidney sizes/masses, renal function indicators, plasma concentrations of PCS/IS, tissue expressions of TIF, α-SMA, collagen IaI, collagen IV and signaling pathways in transforming growth factor-β (TGF-β) family were analyzed among the control, PE, AAN, and AAN-PE groups. PE ameliorated AAN-induced renal atrophy, renal function deterioration, TIF, plasma retention of PCS and IS. PE also suppressed α-SMA expression and deposition of collagen IaI and IV in the fibrotic epithelial-mesenchymal transition. Notably, PE treatment in AAN model inhibited not only SMAD 2/3-dependent pathways but also SMAD-independent JNK/ERK activation in the signaling cascades of TGF-β family. Through disrupting fibrotic epithelial-mesenchymal transition and TGF-β signaling transduction pathways, PE improves TIF and thereby facilitates renal excretion of PCS and IS in AAN. In light of multi-faced toxicity of AAs, PE may be capable of developing a new potential drug to treat CKD patients exposed to AAs.

2020 ◽  
Vol 39 (12) ◽  
pp. 1628-1638 ◽  
Author(s):  
J-Y Zhao ◽  
X-L Wang ◽  
Y-C Yang ◽  
B Zhang ◽  
Y-B Wu

Acute kidney injury (AKI) is an independent risk factor for chronic kidney disease (CKD). However, the role and mechanism of microRNA (miRNA, miR) in AKI-CKD transition are elusive. In this study, a murine model of renal ischemia/reperfusion was established to investigate the repairing effect and mechanism of miR-101a-3p on renal injury. The pathological damage of renal tissue was observed by hematoxylin and eosin and Masson staining. The levels of miR-101, profibrotic cytokines, and epithelial–mesenchymal transition (EMT) markers were analyzed using Western blotting, real-time polymerase chain reaction, and/or immunofluorescence. MiR-101 overexpression caused the downregulation of α-smooth muscle actin, collagen-1, and vimentin, as well as upregulation of E-cadherin, thereby alleviating the degree of renal tissue damage. MiR-101 overexpression mitigated hypoxic HK-2 cell damage. Collagen, type X, alpha 1 and transforming growth factor β receptor 1 levels were downregulated in hypoxic cells transfected with miR-101 mimic. Our study indicates that miR-101 is an anti-EMT miRNA, which provides a novel therapeutic strategy for AKI-CKD transition.


2007 ◽  
Vol 292 (2) ◽  
pp. F567-F576 ◽  
Author(s):  
Lindsay R. White ◽  
Jason B. Blanchette ◽  
Li Ren ◽  
Ali Awn ◽  
Kiril Trpkov ◽  
...  

The hallmark of progressive chronic kidney disease is the deposition of extracellular matrix proteins and tubulointerstitial fibrosis. Integrins mediate cell-extracellular matrix interaction and may play a role tubular epithelial injury. Murine primary tubular epithelial cells (TECs) express α5-integrin, a fibroblast marker and the natural receptor for fibronectin. Microscopy localized α5-integrin on E-cadherin-positive cells, confirming epithelial expression. The expression of α5-integrin increased in TECs grown on fibronectin and occurred in parallel with an upregulation of α-smooth muscle actin (αSMA), a marker of epithelial-mesenchymal transition (EMT). Exposure of TECs to transforming growth factor (TGF)-β also increased TEC α5-integrin expression in association with αSMA and EMT. Knock-down of α5-integrin expression with short interfering RNA attenuated the TGF-β induction of αSMA but did not alter morphologic EMT. Rather, α5-integrin was necessary for epithelial cell migration on fibronectin but not type IV collagen during cell spreading and epithelial wound healing in vitro. Immunohistochemistry revealed basolateral tubular epithelial α5-integrin expression in mouse kidneys after unilateral ureteric obstruction but not in contralateral control kidneys. In patient biopsies of nondiabetic kidney disease, α5-integrin expression was increased significantly in the renal interstitium. Focal basolateral staining was also detected in injured, but not in normal, tubular epithelium. In summary, these data show that TECs are induced to express α5-integrin during EMT and tubular epithelial injury in vitro and in vivo. These results increase our understanding of the biology of integrins during EMT and tubular injury in chronic kidney disease.


2021 ◽  
Vol 22 (12) ◽  
pp. 6270
Author(s):  
Chia-Ter Chao ◽  
Shih-Hua Lin

The accumulation of uremic toxins (UTs) is a prototypical manifestation of uremic milieu that follows renal function decline (chronic kidney disease, CKD). Frailty as a potential outcome-relevant indicator is also prevalent in CKD. The intertwined relationship between uremic toxins, including small/large solutes (phosphate, asymmetric dimethylarginine) and protein-bound ones like indoxyl sulfate (IS) and p-cresyl sulfate (pCS), and frailty pathogenesis has been documented recently. Uremic toxins were shown in vitro and in vivo to induce noxious effects on many organ systems and likely influenced frailty development through their effects on multiple preceding events and companions of frailty, such as sarcopenia/muscle wasting, cognitive impairment/cognitive frailty, osteoporosis/osteodystrophy, vascular calcification, and cardiopulmonary deconditioning. These organ-specific effects may be mediated through different molecular mechanisms or signal pathways such as peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), mitogen-activated protein kinase (MAPK) signaling, aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Runt-related transcription factor 2 (RUNX2), bone morphogenic protein 2 (BMP2), osterix, Notch signaling, autophagy effectors, microRNAs, and reactive oxygen species induction. Anecdotal clinical studies also suggest that frailty may further accelerate renal function decline, thereby augmenting the accumulation of UTs in affected individuals. Judging from these threads of evidence, management strategies aiming for uremic toxin reduction may be a promising approach for frailty amelioration in patients with CKD. Uremic toxin lowering strategies may bear the potential of improving patients’ outcomes and restoring their quality of life, through frailty attenuation. Pathogenic molecule-targeted therapeutics potentially disconnect the association between uremic toxins and frailty, additionally serving as an outcome-modifying approach in the future.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Byung Min Ye ◽  
Il Young Kim ◽  
Min Jeong Kim ◽  
Soo Bong Lee ◽  
Dong Won Lee ◽  
...  

Abstract Background and Aims Acute kidney injury (AKI) is an underestimated, yet important risk factor for the development of chronic kidney disease (CKD), which is characterized by the tubulointerstitial fibrosis and tubular epithelial-mesenchymal transition (EMT). Akt has been reported to be involved in renal fibrosis and EMT. Thus, we investigated the role of Akt1, one of the three Akt isoforms, in the murine model of AKI to CKD progression. Method We subjected the wild type and Akt1−/− mice to unilateral ischemia-reperfusion injury (UIRI). UIRI was induced by clamping the left renal artery for 30 min followed by reperfusion. After 6 weeks of UIRI, the renal fibrosis and EMT were assessed by histology, immunohistochemistry, and western blot. Results After 6 weeks after UIRI, we found that Akt1, not Akt2 or Akt3, was activated in UIRI-kidney. The tubulointerstitial fibrosis was significantly alleviated in Akt1−/− mice compared with the wild type (WT) mice. Besides, the deletion of Akt1 decreased the expression of the vimentin and α-SMA and increased the expression of E-cadherin, indicating the suppression of tubular EMT. However, there was no difference in the activity of TGF-β1/Smad signalling, which is the potent inducer of renal fibrosis and EMT, between WT mice and Akt1−/− mice. The deletion of Akt1 also increased the GSK-3β activity and decreased the expression of β-catenin, Snail, and twist1. Conclusion Our findings demonstrate that the deletion of Akt1 attenuates the renal fibrosis and tubular EMT independently of TGF-β1/Smad signalling during the AKI to CKD progression. Akt1 may be the therapeutic target against the AKI to CKD progression.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yoshinari Yasuda ◽  
Ryosuke Kikuchi ◽  
Kazunori Goto ◽  
Ahmad Baseer Kaihan ◽  
Sawako Kato ◽  
...  

Abstract Background and Aims Uremic toxins have been highlighted as serious risk factors for deterioration of renal function and onset/progression of cardiovascular diseases (CVD). Serum level of indoxyl sulphate (IS), a major uremic toxin, was demonstrated its significant association with vascular disease and mortality in a cohort of chronic kidney disease (CKD) patients, however, IS has not been available in clinical setting due to time consuming and expensive measurement cost. Recently epoch-making IS measurement method applicable for general auto analyzer has been developed, which could explore new therapeutic avenue in CKD from the view point of uremic toxin management. In this study, clinical utility of new enzymatic IS measurement method was analyzed in association with renal function and CVD among CKD patients. Method Subjects were consecutive 150 CKD patients in Nagoya University Hospital whose serum samples were collected between 2009 and 2014. Serum IS levels were measured by “NIPRO” reagent and analyzed with eGFR, CVD events and renal outcomes defined by 30% decrease in eGFR. Results Characteristics of patients were 69 ± 10 years old, 29% female, eGFR: 44 ± 20 mL/min/1.73m2 (∼G3a: 43%, G3b: 29%, G4: 24%, G5: 4%), proteinuria 2.8 ± 3. 5g/gCr (A1: 29%, A2: 29%, A3: 42%), HTN: 83%, and DM: 39%. Serum IS levels (μmol/L) were 10.5 ± 7.5 (∼G3a: 1.8 ± 0.6, G3b: 2.1 ± 0.6, G4: 15.8 ± 8.1, G5: 22.9 ± 13.5), and strongly correlated with eGFR (r =0.518, P<0.001). Among IS low (<6), middle and high (≥12) tertiles, significantly different factors were age, eGFR, Hb, iPTH and LDL-C. In multiple logistic regression analysis, only eGFR was significant associating factor with IS tertiles. IS levels in 2 patients prescribed AST-120 (Kremezin) were 8.1 and 10.3, which seems to be very low in comparison to their eGFR of 13.8 and 13.7. During observation period of 5.1 ± 1.0 years, 59 renal outcomes and 9 CVD events were observed. Kaplan-Meier survival curve analysis free from renal outcomes revealed better tendency in IS low group (p= 0.0617 in log-rank test). According to IS levels adjusted by eGFR, only 1 out of 9 CVD events occurred in low IS/eGFR tertile group. Conclusion Serum IS levels could be measured in new enzymatic method. Strong correlation between IS and eGFR was demonstrated, and AST-120 might be effective to improve IS. In renal and CVD outcome analysis, more sample size is needed for further study.


2018 ◽  
Vol 45 (6) ◽  
pp. 2293-2304 ◽  
Author(s):  
Mohammed Al Za’abi ◽  
Suhail Al Salam ◽  
Yousuf Al Suleimani ◽  
Priyadarsini Manoj ◽  
Abderrahim Nemmar ◽  
...  

Background/Aims: The effect of treatment with gum acacia (GA), a prebiotic shown previously to ameliorate chronic kidney disease (CKD), in diabetic and non – diabetic rats with adenine – induced CKD has been investigated using several conventional and novel physiological, biochemical, and histopathological parameters. Methods: Diabetes mellitus was induced in rats by a single injection of streptozotocin (STZ). Diabetic and non – diabetic rats were randomly divided into several groups, and given either normal food or food mixed with adenine (0.25% w/w, for five weeks) to induce CKD. Some of these groups were also concomitantly treated orally with GA in the drinking water (15% w/w). Results: Rats fed adenine alone exhibited physiological (decreased body weight, increased food and water intake and urine output), biochemical (increase in urinary albumin/creatinine ratio, plasma urea and, creatinine, indoxyl sulfate and phosphorus), inflammatory biomarkers (increased in neutrophil gelatinase-associated lipocalin, transforming growth factor beta -1, tumor necrosis factor alpha, adiponectin, cystatin C and interleukin-1β), oxidative biomarkers (8-isoprostane, 8 -hydroxy -2-deoxy guanosine), nitrosative stress biomarkers (nitrite and nitrate) and histopathological (increase in tubular necrosis and fibrosis) signs of CKD. STZ - induced diabetes alone worsened most of the renal function tests measured. Administration of adenine in STZ – diabetic rats further worsened the renal damage induced by adenine alone. GA significantly ameliorated the renal actions of adenine and STZ, given either singly or in combination, especially with regards to the histopathological damage. Conclusion: GA is a useful dietary agent in attenuating the progression of CKD in rats with streptozotocin-induced diabetes.


2020 ◽  
Author(s):  
Cheng-Hsu Chen ◽  
Shih-Chien Huang ◽  
Pei-Chih Lin ◽  
Shang-Feng Tsai ◽  
Yi-Chia Huang

Abstract Background: Increased levels of uremic toxins and decreased antioxidant capacities have a significant impact on the progression of chronic kidney disease (CKD). However, it is unclear whether they interact with each other in order to mediate the damage of renal function. The purpose of this study was to determine whether uremic toxins [i.e., homocysteine and indoxyl sulfate (IS)] and glutathione-dependent antioxidant enzyme activities are dependently or independently associated with each other in affecting renal function during different stages of CKD patients.Methods: One hundred thirty-two patients diagnosed with CKD stage 1 to 5 participated in this cross-sectional study.Results: Patients who had reached an advanced CKD stage experienced a gradual increase in plasma uremic toxin levels, along with decreased glutathione peroxidase (GSH-Px) activities. Plasma homocysteine, cysteine and IS concentrations were positively associated with each other, but negatively correlated to GSH-Px activity levels after adjusting potential confounders in all CKD patients. Although plasma homocysteine, cysteine, IS and GSH-Px levels were significantly associated with renal function, only plasma IS levels still had a significant association with renal function after these parameters were simultaneously adjusted.Conclusions: IS plays a more dominant role than other factors in affecting renal function, where a higher IS concentration needs to be controlled in order to defer the progressive loss of renal function.


Author(s):  
Myrna Y. Munar ◽  
Ali J. Olyaei

The kidneys play an important role in the elimination of many drugs. In chronic kidney disease and acute kidney injury several pharmacokinetic processes are altered. Thus, patients with impaired renal function require adjustment of medication dosing. Many drugs require a loading dose to rapidly achieve therapeutic plasma concentrations. Subsequently, the dose or dosing interval may have to be adjusted as appropriate for the degree for renal function. The most common method to estimate renal function is use of the Cockcroft–Gault (CG) equation. It has been well validated, is easy to remember, and is fairly accurate in estimating kidney function. Most drugs are dosed based on the patient’s weight (mg/kg), which makes the CG method easier to use for most estimates. Other methods are available and a patient’s renal function should always be estimated based on the best available evidence for that specific patient. Patients with chronic kidney disease are at great risk of developing kidney injury from drugs or diagnostic agents. Exposure to nephrotoxins should be avoided as much as possible.


2019 ◽  
Vol 3 (9) ◽  
Author(s):  
Rattiyaporn Kanlaya ◽  
Visith Thongboonkerd

ABSTRACT Chronic kidney disease (CKD) is a common public health problem worldwide characterized by gradual decline of renal function over months/years accompanied by renal fibrosis and failure in tissue wound healing after sustained injury. Patients with CKD frequently present with profound signs/symptoms that require medical treatment, mostly culminating in hemodialysis and renal transplantation. To prevent CKD more efficiently, there is an urgent need for better understanding of the pathogenic mechanisms and molecular pathways of the disease pathogenesis and progression, and for developing novel therapeutic targets. Recently, several lines of evidence have shown that epigallocatechin-3-gallate (EGCG), an abundant phytochemical polyphenol derived from Camellia sinensis, might be a promising bioactive compound for prevention of CKD development/progression. This review summarizes current knowledge of molecular mechanisms underlying renoprotective roles of EGCG in CKD based on available preclinical evidence (from both in vitro and in vivo animal studies), particularly its antioxidant property through preservation of mitochondrial function and activation of Nrf2 (nuclear factor erythroid 2-related factor 2)/HO-1 (heme oxygenase-1) signaling, anti-inflammatory activity, and protective effect against epithelial mesenchymal transition. Finally, future perspectives, challenges, and concerns regarding its clinical use in CKD and renal fibrosis are discussed.


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