FHL2‐driven molecular network mediated Septin2 knockdown inducing apoptosis in mesangial cell

The apoptosis of mesangial cells (MCs) plays a critical role in the pathological progress of MesPGN. Septin2, a filamentous GTPase, is implicated in the apoptotic progress of MCs in the rat MesPGN model. However, the molecular mechanism of SEPT2 in MCs apoptosis is not clear. Here, we present the FHL2‐driven molecular network as the main mechanism of SEPT2‐mediated rat primary MCs apoptosis. First, we proved that the expression of FHL2 and Septin2 were closely related with MCs apoptosis in anti‐Thy1 nephritis model. Then, it was found that FHL2 was a new interaction protein of Septin2 and Septin2 knockdown could induce MC apoptosis by FHL2‐mediatied signal pathways including p‐ERK1 and p‐AKT. We applied label‐Free quantitative proteomics to identify the mechanism of Septin2/FHL2‐regulated apoptosis. Bioinformatics analysis revealed that FHL2‐driven molecular network composed of biological functions including glycolysis, oxidative stress, ribonucleotide metabolism, actin cytoskeleton regulation, and signaling pathway, was the main mechanism of SETP2‐mediated apoptosis. Furthermore, we showed that the effect of Septin2 knockdown on MC apoptosis could be alleviated by the overexpression of FHL2. Overall, this study illustrated the FHL2‐driven molecular network controlling SEPT2‐mediated apoptosis in MCs and their potential roles in mesangial proliferative nephritis.     

Sublytic C5b‐9 induces proliferation of glomerular mesangial cells via ERK5/MZF1/RGC‐32 axis activated by FBXO28‐TRAF6 complex

Mesangioproliferative glomerulonephritis (MsPGN) is characterized by the proliferation of glomerular mesangial cells (GMCs) and accumulation of extracellular matrix (ECM), followed by glomerulosclerosis and renal failure of patients. Although our previous studies have demonstrated that sublytic C5b‐9 complex formed on the GMC membrane could trigger GMC proliferation and ECM expansion of rat Thy‐1 nephritis (Thy‐1N) as an animal model of MsPGN, their mechanisms are still not fully elucidated. In the present studies, we found that the levels of response gene to complement 32 (RGC‐32), myeloid zinc finger 1 (MZF1), phosphorylated extracellular signal‐regulated kinase 5 (phosphorylated ERK5, p‐ERK5), F‐box only protein 28 (FBXO28) and TNF receptor‐associated factor 6 (TRAF6) were all markedly up‐regulated both in the renal tissues of rats with Thy‐1N (in vivo) and in the GMCs upon sublytic C5b‐9 stimulation (in vitro). Further in vitro experiments revealed that up‐regulated FBXO28 and TRAF6 could form protein complex binding to ERK5 and enhance ERK5 K63‐ubiquitination and subsequent phosphorylation. Subsequently, ERK5 activation contributed to MZF1 expression and MZF1‐dependent RGC‐32 up‐regulation, finally resulting in GMC proliferative response. Furthermore, the MZF1‐binding element within RGC‐32 promoter and the functions of FBXO28 domains were identified. Additionally, knockdown of renal FBXO28, TRAF6, ERK5, MZF1 and RGC‐32 genes respectively markedly reduced GMC proliferation and ECM production in Thy‐1N rats. Together, these findings indicate that sublytic C5b‐9 induces GMC proliferative changes in rat Thy‐1N through ERK5/MZF1/RGC‐32 axis activated by the FBXO28‐TRAF6 complex, which might provide a new insight into MsPGN pathogenesis.     

Urinary Vitamin D Binding Protein and KIM-1 Are Potent New Biomarkers of Major Adverse Renal Events in Patients Undergoing Coronary Angiography

Background

Vitamin-D-binding protein (VDBP) is a low molecular weight protein that is filtered through the glomerulus as a 25-(OH) vitamin D 3/VDBP complex. In the normal kidney VDBP is reabsorbed and catabolized by proximal tubule epithelial cells reducing the urinary excretion to trace amounts. Acute tubular injury is expected to result in urinary VDBP loss. The purpose of our study was to explore the potential role of urinary VDBP as a biomarker of an acute renal damage.

Method

We included 314 patients with diabetes mellitus or mild renal impairment undergoing coronary angiography and collected blood and urine before and 24 hours after the CM application. Patients were followed for 90 days for the composite endpoint major adverse renal events (MARE: need for dialysis, doubling of serum creatinine after 90 days, unplanned emergency rehospitalization or death).

Results

Increased urine VDBP concentration 24 hours after contrast media exposure was predictive for dialysis need (no dialysis: 113.06 ± 299.61ng/ml, n = 303; need for dialysis: 613.07 ± 700.45 ng/ml, n = 11, Mean ± SD, p<0.001), death (no death during follow-up: 121.41 ± 324.45 ng/ml, n = 306; death during follow-up: 522.01 ± 521.86 ng/ml, n = 8; Mean ± SD, p<0.003) and MARE (no MARE: 112.08 ± 302.00ng/ml, n = 298; MARE: 506.16 ± 624.61 ng/ml, n = 16, Mean ± SD, p<0.001) during the follow-up of 90 days after contrast media exposure. Correction of urine VDBP concentrations for creatinine excretion confirmed its predictive value and was consistent with increased levels of urinary Kidney Injury Molecule-1 (KIM-1) and baseline plasma creatinine in patients with above mentioned complications. The impact of urinary VDBP and KIM-1 on MARE was independent of known CIN risk factors such as anemia, preexisting renal failure, preexisting heart failure, and diabetes.

Conclusions

Urinary VDBP is a promising novel biomarker of major contrast induced nephropathy-associated events 90 days after contrast media exposure.     

Morphological insights into the origin of glomerular endothelial and mesangial cells and their precursors.

Glomerular endothelial and mesangial cells may originate from the metanephric mesenchyme. We used the MAb Thy1.1, a mesangial cell marker in the adult rat kidney, and rat endothelial cell markers MAb RECA-1, MAb PECAM-1 (CD31), and MAb Flk-1 as potential markers to characterize the spatial and temporal distribution of mesangial and endothelial cell precursors during nephrogenesis in the rat. At early stages of glomerulogenesis, RECA-1- and Thy1.1-positive cells were detected in the metanephric blastema at 14 days post conception (dpc) embryos and 15 dpc, respectively, with Thy1.1 expression in cells surrounding the ureteric bud. At 17 and 18 dpc, both RECA-1- and Thy1.1-positive cells were found in the cleft of the S-shaped bodies and in the capillary loops of maturing glomeruli. Double staining for BrdU, a marker of proliferation, and for RECA-1 or BrdU and Thy1.1 also localize in the cleft of S-shaped bodies and in glomerular capillary loops at later stages of development. PDGFRbeta co-localizes in cells expressing endothelial or mesangial markers. The data suggest that endothelial and mesangial cell precursors share common markers during the course of glomerulogenesis and that full differentiation of these cells occurs at late stages of glomerular maturation. Thy1.1- and RECA-1-positive cells may be derived from the metanephric blastemal cells at early stages of kidney development. A subpopulation of these Thy1.1- or RECA-1-positive cells may be precursors that can migrate into the cleft of comma and S-shaped bodies and proliferate in situ to form glomerular capillary tufts.     

Bioinformatics analysis of proteomic profiles during the process of anti-Thy1 nephritis

Anti-Thy1 nephritis is a well-established experimental mesangial proliferative nephritis model. Exploring the molecular mechanisms of pathophysiology in anti-Thy1 nephritis may elucidate the pathogeneses of mesangial proliferation. We examined the roles and acting mechanisms of differentially expressed proteins (DEPs) by bioinformatics analysis of glomeruli proteomic profiles during the course of anti-Thy1 nephritis. In total, 108 DEPs were found by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE), and 40 DEPs were identified by matrix-assisted laser desorption ionization/time of flight and liquid chromatography-MS. DEPs were classified into five clusters (Clusters 1-5), according to their expression trends using Cluster 3.0 software, involved in regulating biological processes such as the stress response, cell proliferation, apoptosis, energy metabolism, transport, and the actin cytoskeleton. The expression patterns of ten DEPs, distributed across five clusters, including AKR1A1, AGAT, ATP6V1B2, HIBADH, MDH1, MPST, NIT2, PRDX6, PSMB7, and TPI1, were validated by Western blotting. Based on Western blotting and immunohistochemistry, we also found that the DEP FHL2, which was primarily expressed in the mesangial region, was down-regulated on days 3 and 5, and up-regulated on day 10. In vitro, we found that FHL2 overexpression induced mesangial cell proliferation by increasing the number of S-phase cells and decreasing G2/M-phase cells, whereas inhibiting FHL2 had the opposite effect. This study explored novel DEPs and their expression patterns during anti-Thy1 nephritis, and elucidated FHL2's effect on mesangial cell proliferation. These results will contribute to our understanding of the pathogenesis of mesangial proliferation.     

Interleukin-1 production by mononuclear leukocytes and mesangial cells in experimental nephrotoxic nephritis

We investigated the intensiveness of the cell proliferation, number of mononuclear leucocytes (MNL) and production of interleukin-1 (IL-1) in glomerular cell cultures of rats with nephrotoxic serum (NTS) nephritis and control (C) rats. Five days after intravenous injection of nephrotoxic serum from rabbits the glomeruli were isolated, treated with collagenase and cultured over a period of 20 days. In cultures the number and intensity of mesangial cell proliferation in the NTS group were significantly higher than in the C group. Thus, the intensive mesangial cell proliferation in experimental nephrotoxic serum nephritis is related to infiltration of glomerulus by MNL of bone marrow origin with increased production of IL-1.     

Knockdown of TRIM27 expression suppresses the dysfunction of mesangial cells in lupus nephritis by FoxO1 pathway

TRIM27 (tripartite motif-containing 27) is a member of the TRIM (tripartite motif) protein family and participates in a variety of biological processes. Some research has reported that TRIM27 was highly expressed in certain kinds of carcinoma cells and tissues and played an important role in the proliferation of carcinoma cells. However, whether TRIM27 takes part in the progression of lupus nephritis (LN) especially in cells proliferation remains unclear. Our study revealed that the overexpression of TRIM27 was observed in the kidneys of patients with LN, lupus mice and mesangial cells exposed to LN plasma which correlated with the proliferation of mesangial cells and ECM (extracellular matrix) deposition. Downregulation of TRIM27 expression suppressed the proliferation of mesangial cells and ECM accumulation in MRL/lpr mice and cultured human mesangial cells (HMCs) by regulating the FoxO1 pathway. Furthermore, the overexpression of FoxO1 remarkably decreased HMCs proliferation level and ECM accumulation in LN plasma-treated HMCs. In addition, the protein kinase B (Akt) signal pathway inhibitor LY294002 significantly reduced the expression of TRIM27 and inhibited the dysfunction of mesangial cells. These above data suggested that TRIM27 mediated abnormal mesangial cell proliferation in kidney of lupus and might be the potential target for treating mesangial cell proliferation of lupus nephritis.     

HMGB1 protein promotes glomerular mesangial matrix deposition via TLR2 in lupus nephritis

Lupus nephritis (LN) is the most common complication of systemic lupus erythematosus. Patients with LN mostly die of sclerosing glomerulonephritis and renal failure. The inhibition of glomerular mesangial matrix deposition is an efficient method to restrict the progress of renal injury. By recognizing and binding extracellular and intracellular ligands, Toll-like receptor 2 (TLR2) contributes to the pathogenesis of most immune diseases. However, the relationship between TLR2 and LN is still unknown. Our previous studies confirmed that high-mobility group box 1 (HMGB1), an important ligand of TLR2, promotes the progression of LN by inducing the proliferation of glomerular mesangial cells. However, whether or not HMGB1 participates in the pathogenesis of glomerular mesangial matrix deposition in LN remains unknown. In this study, we observed the upregulated expression of TLR2 in the glomeruli of LN patients and MRL/lpr mice. The inhibition of either TLR2 or HMGB1 inhibited the release of fibronectin and the activation of the MyD88/NF-κB pathway in mesangial cells cultured with LN plasma. In addition, both TLR2- and HMGB1-deficient mice showed reduced 24 hr urine protein levels and improved glomerular histological changes and sclerosis levels. These results indicate that TLR2 regulates glomerular mesangial matrix deposition in LN through the activation of the MyD88/NF-κB pathway by binding to HMGB1.     

Is Vitamin D Binding Protein a Novel Predictor of Labour?

Vitamin D binding protein (VDBP) has previously been identified in the amniotic fluid and cervicovaginal fluid (CVF) of pregnant women. The biological functions of VDBP include acting as a carrier protein for vitamin D metabolites, the clearance of actin that is released during tissue injury and the augmentation of the pro-inflammatory response. This longitudinal observational study was conducted on 221 healthy pregnant women who spontaneously laboured and delivered either at term or preterm. Serial CVF samples were collected and VDBP was measured by ELISA. Binary logistic regression analysis was performed to assess the utility of VDBP as a predictor of labour. VDBP in the CVF did not change between 20 and 35 weeks'' gestation. VDBP measured in-labour was significantly increased 4.2 to 7.4-fold compared to 4–7, 8–14 and 15–28 days before labour (P<0.05). VDBP concentration was 4.3-fold significantly higher at 0–3 days compared to 15–28 days pre-labour (P<0.05). The efficacy of VDBP to predict spontaneous labour onset within 3 days provided a positive and negative predictive value of 82.8% and 95.3% respectively (area under receiver operator characteristic curve  = 0.974). This longitudinal study of pregnant women suggests that VDBP in the CVF may be a useful predictor of labour.     

Activation of Src mediates PDGF-induced Smad1 phosphorylation and contributes to the progression of glomerulosclerosis in glomerulonephritis

Platelet-derived growth factor (PDGF) plays critical roles in mesangial cell (MC) proliferation in mesangial proliferative glomerulonephritis. We showed previously that Smad1 contributes to PDGF-dependent proliferation of MCs, but the mechanism by which Smad1 is activated by PDGF is not precisely known. Here we examined the role of c-Src tyrosine kinase in the proliferative change of MCs. Experimental mesangial proliferative glomerulonephritis (Thy1 GN) was induced by a single intravenous injection of anti-rat Thy-1.1 monoclonal antibody. In Thy1 GN, MC proliferation and type IV collagen (Col4) expression peaked on day 6. Immunohistochemical staining for the expression of phospho-Src (pSrc), phospho-Smad1 (pSmad1), Col4, and smooth muscle α-actin (SMA) revealed that the activation of c-Src and Smad1 signals in glomeruli peaked on day 6, consistent with the peak of mesangial proliferation. When treated with PP2, a Src inhibitor, both mesangial proliferation and sclerosis were significantly reduced. PP2 administration also significantly reduced pSmad1, Col4, and SMA expression. PDGF induced Col4 synthesis in association with increased expression of pSrc and pSmad1 in cultured MCs. In addition, PP2 reduced Col4 synthesis along with decreased pSrc and pSmad1 protein expression in vitro. Moreover, the addition of siRNA against c-Src significantly reduced the phosphorylation of Smad1 and the overproduction of Col4. These results provide new evidence that the activation of Src/Smad1 signaling pathway plays a key role in the development of glomerulosclerosis in experimental glomerulonephritis.     

应用高脂饮食联合维生素D3建立慢性系膜增殖性肾炎血管病变大鼠模型

目的 探讨应用高脂饮食建立慢性系膜增殖性肾炎血管病变模型的方法.方法 雄性Wistar大鼠行单侧肾切除后随机分为单纯肾切除组、单纯肾炎组、单纯高脂组、肾炎高脂组.单纯肾炎组、肾炎高脂组在单侧肾切除后3d尾静脉注射OX7抗体(100 mg/kg),1周后尾静脉连续注射OX7抗体(每次100 mg/kg,1次/周,共3次),单纯肾切除组和单纯高脂组在同一时间尾静脉注射PBS,注射抗体后第2天单纯高脂组、肾炎高脂组腹腔注射维生素D3(6万U/kg,1次/4周),同时给予高脂饲料.分别于第4、8、10周观察各组大鼠的一般情况、体重、血压、尿蛋白、血浆白蛋白、血脂、血钙、肾功能以及肾脏病理改变.结果 模型组(肾炎高脂组)大鼠第8周肾小球外的小动脉出现管壁增厚,管腔变小,平滑肌细胞减少,细胞排列紊乱,纤维组织增生.第10周单纯肾炎组和单纯高脂组肾小球外小动脉管壁轻度增厚,管腔变化不明显,模型组血管病变积分明显高于单纯肾炎组和单纯高脂组(P＜0.05).结论 通过对慢性抗Thy1肾炎大鼠加用高脂饲料并腹腔注射维生素D3的方法,可以成功建立慢性系膜增殖性肾炎血管病变模型.     

An ultrastructural study of proliferative nephritis induced experimentally by a monoclonal antibody against mesangial cells: replacement of mesangial cells by cells of the monocyte-macrophage system

An experimental nephritis accompanied by transient proteinuria can be produced by an intravenous injection of the monoclonal antibody, 1-22-3, raised against isolated rat glomeruli. The present study deals with the ultrastructural changes in the glomeruli in rats after the injection of this antibody. At 2 h after injection, all the mesangial cells had completely degenerated and neutrophils invaded most mesangial areas. Monocytes occupied the vacant mesangial areas at 24 h and gradually increased in number over the next 4 days. At 4 and 6 days, macrophage-like cells, possibly derived from monocytes, underwent frequent mitosis, resulting in a remarkable proliferation of these cells. The interpretation of these cells as macrophages was strongly supported by the fact that they contained previously injected latex particles in large numbers. From 2 to 4 weeks after injection, the macrophage-like cells gradually transformed into cells indistinguishable from normal mesangial cells. In the present experimental nephritis where all mesangial cells were initially destroyed, cells of the monocyte-macrophage system appear to play a leading role in the pathogenesis of the ensuing proliferative glomerulonephritis, and represent the source of the replacing mesangial cells.     

Comparison of Plasma and Urine Biomarker Performance in Acute Kidney Injury

Background

New renal biomarkers measured in urine promise to increase specificity for risk stratification and early diagnosis of acute kidney injury (AKI) but concomitantly may be altered by urine concentration effects and chronic renal insufficiency. This study therefore directly compared the performance of AKI biomarkers in urine and plasma.

Methods

This single-center, prospective cohort study included 110 unselected adults undergoing cardiac surgery with cardiopulmonary bypass between 2009 and 2010. Plasma and/or urine concentrations of creatinine, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), liver fatty acid-binding protein (L-FABP), kidney injury molecule 1 (KIM1), and albumin as well as 15 additional biomarkers in plasma and urine were measured during the perioperative period. The primary outcome was AKI defined by AKIN serum creatinine criteria within 72 hours after surgery.

Results

Biomarkers in plasma showed markedly better discriminative performance for preoperative risk stratification and early postoperative (within 24h after surgery) detection of AKI than urine biomarkers. Discriminative power of urine biomarkers improved when concentrations were normalized to urinary creatinine, but urine biomarkers had still lower AUC values than plasma biomarkers. Best diagnostic performance 4h after surgery had plasma NGAL (AUC 0.83), cystatin C (0.76), MIG (0.74), and L-FAPB (0.73). Combinations of multiple biomarkers did not improve their diagnostic power. Preoperative clinical scoring systems (EuroSCORE and Cleveland Clinic Foundation Score) predicted the risk for AKI (AUC 0.76 and 0.71) and were not inferior to biomarkers. Preexisting chronic kidney disease limited the diagnostic performance of both plasma and urine biomarkers.

Conclusions

In our cohort plasma biomarkers had higher discriminative power for risk stratification and early diagnosis of AKI than urine biomarkers. For preoperative risk stratification of AKI clinical models showed similar discriminative performance to biomarkers. The discriminative performance of both plasma and urine biomarkers was reduced by preexisting chronic kidney disease.     

Discovery of early urinary biomarkers in preclinical study of gentamicin-induced kidney injury and recovery in rats

LC/MS- and NMR-based global metabolomics analyses were utilized to study the changes in rat urine in response to gentamicin treatment. Sprague?CDawley rats were dosed with gentamicin sulfate at 0, 75, 150 or 300?mg/kg/day for one, two or three consecutive days. Four animals from each group were sacrificed to harvest kidney tissue and to collect urine on days 1, 2, 3, 7, 10, 15, 18, 22, 29, 36 and 44 for a total of 11 different time points. Both uni- and multivariate statistical analyses were employed to identify the significantly changed metabolites in urine at the different dose levels and time points. Increases and decreases in amino acids including tyrosine, valine and hydroxyproline reflected histopathology changes of kidney injury development and/or kidney injury recovery. Glucosuria was noted much earlier than changes in the classic kidney function biomarkers, blood urea nitrogen and serum creatinine. Dopamine-related compounds, homovanillic acid sulfate (HVA-SO₄) and homoveratric acid sulfate (HVrA-SO₄) were significantly increased at early time points and could be early indicators of a renal adaptive response to gentamicin-induced renal injury. Furthermore, the drug efficacy of gentamicin was evaluated through the detection of changes in gut microflora-related compounds (e.g. indole-containing metabolites). Metabolomics was successful in identifying valine, hydroxyproline, HVA-SO₄ and HVrA-SO₄ that might serve as potential early injury biomarkers or adaptive markers of gentamicin-induced renal injury, and in assessing gentamicin efficacy through changes in compounds reported to be related to gut microflora. However, caution should be taken in direct translation of the biomarkers reported in clinical settings because a much higher dose of gentamicin than the normal therapeutic dose (~1?C2?mg/kg) was used to cause kidney damaged.     

Renoprotective effects of montelukast in an experimental model of cisplatin nephrotoxicity in rats

Renal toxicity is one of the most severe complications that can occur with cisplatin (CIS) administration in cancer patients. Montelukast (ML) renoprotective outcome contrary to CIS‐drawn nephrotoxicity remains obscure. Therefore, adult male Sprague–Dawley rats were orally given ML (10 and 20 mg/kg/day) 5 days before and after single CIS (5 mg/kg; i.p.) treatment. ML returned blood urea nitrogen, as well as serum creatinine and gamma glutamyl transferase that were elevated by CIS to normal level. The improved kidney function tests corroborated the attenuation of CIS renal injury at the microscopical level. It also reduced serum/renal nitric oxide and renal hemeoxygenase‐1. Meanwhile, ML hindered the raised levels of serum endothelin‐1, serum and renal tumor necrosis factor‐α, and monocyte chemoattractant protein‐1. These effects were associated by deceased caspase‐3 expression in kidney after ML treatment. In conclusion, ML guards against CIS‐induced nephrotoxicity via anti‐inflammatory and antiapoptotic properties.     

Evidence of Uncoupling between Renal Dysfunction and Injury in Cardiorenal Syndrome: Insights from the BIONICS Study

Objective

The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF).

Methods

In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF.

Results

26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF.

Conclusions

In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153).     

Low‐energy shock wave pretreatment recruit circulating endothelial progenitor cells to attenuate renal ischaemia reperfusion injury

Low‐energy shock wave (LESW) has been recognized as a promising non‐invasive intervention to prevent the organs or tissues against ischaemia reperfusion injury (IRI), whereas its effect on kidney injury is rarely explored. To investigate the protective role of pretreatment with LESW on renal IRI in rats, animals were randomly divided into Sham, LESW, IRI and LESW + IRI groups. At 4, 12, 24 hours and 3 and 7 days after reperfusion, serum samples and renal tissues were harvested for performing the analysis of renal function, histopathology, immunohistochemistry, flow cytometry and Western blot, as well as enzyme‐linked immunosorbent assay. Moreover, circulating endothelial progenitor cells (EPCs) were isolated, labelled with fluorescent dye and injected by tail vein. The fluorescent signals of EPCs were detected using fluorescence microscope and in vivo imaging system to track the distribution of injected circulating EPCs. Results showed that pretreatment with LESW could significantly reduce kidney injury biomarkers, tubular damage, and cell apoptosis, and promote cell proliferation and vascularization in IRI kidneys. The renoprotective role of LESW pretreatment would be attributed to the remarkably increased EPCs in the treated kidneys, part of which were recruited from circulation through SDF‐1/CXCR7 pathway. In conclusion, pretreatment with LESW could increase the recruitment of circulating EPCs to attenuate and repair renal IRI.     

Predictive Usefulness of Urinary Biomarkers for the Identification of Cyclosporine A-Induced Nephrotoxicity in a Rat Model

The main side effect of cyclosporine A (CsA), a widely used immunosuppressive drug, is nephrotoxicity. Early detection of CsA-induced acute nephrotoxicity is essential for stop or minimize kidney injury, and timely detection of chronic nephrotoxicity is critical for halting the drug and preventing irreversible kidney injury. This study aimed to identify urinary biomarkers for the detection of CsA-induced nephrotoxicity. We allocated salt-depleted rats to receive CsA or vehicle for 7, 14 or 21 days and evaluated renal function and hemodynamics, microalbuminuria, renal macrophage infiltration, tubulointerstitial fibrosis and renal tissue and urinary biomarkers for kidney injury. Kidney injury molecule-1 (KIM-1), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), fibronectin, neutrophil gelatinase-associated lipocalin (NGAL), TGF-β, osteopontin, and podocin were assessed in urine. TNF-α, IL-6, fibronectin, osteopontin, TGF-β, collagen IV, alpha smooth muscle actin (α -SMA) and vimentin were assessed in renal tissue. CsA caused early functional renal dysfunction and microalbuminuria, followed by macrophage infiltration and late tubulointerstitial fibrosis. Urinary TNF-α, KIM-1 and fibronectin increased in the early phase, and urinary TGF-β and osteopontin increased in the late phase of CsA nephrotoxicity. Urinary biomarkers correlated consistently with renal tissue cytokine expression. In conclusion, early increases in urinary KIM-1, TNF-α, and fibronectin and elevated microalbuminuria indicate acute CsA nephrotoxicity. Late increases in urinary osteopontin and TGF-β indicate chronic CsA nephrotoxicity. These urinary kidney injury biomarkers correlated well with the renal tissue expression of injury markers and with the temporal development of CsA nephrotoxicity.