Rat Renal Tissue Research Articles

Oral administration of powdered dried rhizomes of Curcuma longa L. (turmeric, Zingiberaceae) is effective in the treatment of doxorubicin-induced kidney injury in rats.

Curcumin is a polyphenol present in the rhizomes of the species Curcuma longa L. ("turmeric," Zingiberaceae), which has been used for centuries as an anti-inflammatory. We aimed to evaluate the anti-inflammatory effects of C.longa in renal injury induced by doxorubicin (DOX, 3.5mg.kg-1 IV). We studied four groups of Wistar rats: two groups with DOX-induced kidney injury, one fed with standard food and another with standard food mixed with C.longa (5mg.g-1 ). Two other control groups without kidney injury were fed with the same foods. We measured albuminuria, body weight, and food intake every 2weeks. After 8weeks, treatment with C.longa did not change albuminuria, but it significantly attenuated the excretion of urinary inflammatory markers monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-β (TGF-β) and significantly attenuated immunostaining for desmin, vimentin, and ED-1+ cells in renal tissues of rats with DOX-induced kidney injury. In addition, treatment with C.longa resulted in significantly lower glomerular and tubule interstitial injury scores, compared with that in the DOX-STD group. In conclusion, administration of powdered rhizomes of C.longa for 8weeks to rats with DOX-induced kidney injury did not reduce albuminuria but led to a significant decrease in urinary inflammatory markers MCP-1 and TGF-β and decreased histopathological alterations and immunostaining for desmin, vimentin, and ED-1+ cells kidneys tissues.

The Effect of Intermittent Hypobaric Hypoxia Exposure on Reduced-Glutathione Level in Rat Lung and Renal Tissues

Hypobaric hypoxia is basically a hypoxia condition experienced in high altitude commonly during flight, that increase reactive oxygen species (ROS). When hypoxia hypobaric does not undergo continuation or in other word, intermittent, it will cause adaptation response in a form of protection mode into ROS. Moreover, ROS could be eliminated by reduced-glutathione (GSH) as an endogenous non enzymatic antioxidant. Therefore, the aim of this study was to analyze the effects of intermittent hypobaric hypoxia exposure on GSH level in rat lung and renal tissue. Lung and renal samples were collected from 6–8 weeks old male Sprague-Dawley rats weighing 150–200 g, previously exposed 1–4 times to intermittent hypobaric hypoxia in 35,000 ft (1 minute), 25.000 ft (5 minute) and 18,000 ft altitude (25 minute). Afterwards, GSH level was calculated from lung and renal extracts using the Ellman’s method. In lung tissues, GSH level was decreased in hypoxia 1×, 2×, 3×, 4× treatment, and were significant between the control–hypoxia 3×, control–hypoxia 4×, hypoxia 1×–hypoxia 3× and hypoxia 1×–hypoxia 4×. On the contrary, GSH level was increased in renal tissues on hypoxia 1× and hypoxia 2× treatment compared to control. Nevertheless, GSH level was decreased after 3× treatment and found almost stabilized at 4× treatment of hypoxia in renal tissues. Intermittent hypobaric hypoxia exposure affect GSH in rat lung and renal tissues with varying level as an adaptive response system.

P3H4 affects renal carcinoma through up-regulating miR-1/133a.

P3H4, as a kind of quinone compounds, is a coenzyme Q10 (ubiquinone) analogues. A recent study investigated the role of P3H4 on cerebral ischemia-reperfusion and hypertension. It is well known that ischemia-reperfusion is closely associated with kidney disease. This study aims to investigate the impact of P3H4 in the occurrence and development of the tumor. A total of 40 rats at 8-week old were selected to establish renal cancer model by burying suture method for 4 months. The rats in the experimental group received P3H4 treatment at 100 mg/kg every 48 h for consecutive 4 weeks, while the rats in control received normal saline. H&E staining was applied to test the histological changes of tissue at 0, 1, 2 weeks after treatment. Gene microarray was adopted to screen miRNA expression to explore the function of miRNA in renal cancer cell line. Renal cancer cell migration and invasion were evaluated by wound healing and transwell assays after the treatment of P3H4, miR-1a, miR-133a, respectively. The rats were randomly equally divided into experimental group and control. HE staining result showed renal interstitial fibroblasts hyperplasia, renal tubular necrosis, and glomerular reduction after modeling. P3H4 treatment significantly alleviated the lesion severity and inhibited the tumor cells invasion. Microarray demonstrated that miR-1a and miR-133a were significantly upregulated in rat renal cancer tissue after the treatment of P3H4. The overexpression of miR-1a and miR-133a markedly reduced renal cell invasion and migration, which was consistent with the effect of P3H4. P3H4 suppressed the development of renal carcinoma through upregulating miR-1a and miR-13a, which provides fundamental leads for the future anti-cancer therapy.

Oxidative stress-induced renal telomere shortening as a mechanism of cyclosporine-induced nephrotoxicity.

Due to the association of oxidative stress and telomere shortening, it was aimed in the present study to investigate the possibility whether cyclosporine-A exerts its nephrotoxic side effects via induction of oxidative stress-induced renal telomere shortening and senescent phenotype in renal tissues of rats. Renal oxidative stress markers, 8-hydroxydeoxyguanosine, malondialdehyde, and protein carbonyl groups were measured by standard methods. Telomere length and telomerase activity were also evaluated in kidney tissue samples. Results showed that cyclosporine-A treatment significantly (P<0.05) enhanced renal malondialdehyde, 8-hydroxydeoxyguanosine, and protein carbonyl groups levels, decreased renal telomere length, and deteriorated renal function compared with the controls. Renal telomerase activity was not affected by cyclosporine-A. Renal telomere length could be considered as an important parameter of both oxidative stress and kidney function. Telomere shortening and accelerated kidney aging may be caused by cyclosporine-induced oxidative stress, indicating the potential mechanism of cyclosporine-induced nephrotoxicity.

Effects of Temperature on FTIR Spectral Characteristics of Renal Tissue in Rats after Death

To analyse the Fourier transform infrared （FTIR） spectral data of renal tissue at different temperatures in rats after death, and to explore the effects of temperature on the FTIR spectral characteristics of renal tissue. The rats were sacrificed by cervical dislocation and placed at 4 ℃, 20 ℃ and 30 ℃. The FTIR spectral data of renal tissue were collected at different time points and analysed by data mining method. The principal component analysis （PCA） results showed that there were significant trends of clustering in the samples of partial time point at 4 ℃, 20 ℃ and 30 ℃. Partial least square （PLS） regression models were established with the spectral data at three temperature groups. The performance of PLS regression models in 20 ℃ and 30 ℃ groups were more superior than that in 4 ℃ group, and the stability of the model in 20 ℃ group was better than that in 30 ℃ group. There are differences in the FTIR spectral characteristics of renal tissue of rats after death at different temperatures. Temperature has a major impact on the performance of FTIR spectral PLS regression model. Therefore, in order to improve the accuracy of postmortem interval estimation, the effects of temperature on the model should be considered in the related study by spectral method.

BML-111 inhibits the inflammatory response and apoptosis of renal tissue in rats with hemorrhagic shock by inhibiting the MAPK pathway.

The effect of lipoxin receptor agonist BML-111 on acute kidney injury and AKI in rats with hemorrhagic shock (HS) and its mechanism were investigated. A model of hemorrhagic shock in Sprague-Dawley (SD) rats was established, and recovered after 30 min of shock. 1 mg/kg BML-111 was intraperitoneally injected at the beginning of resuscitation in group BML-111. The concentration of serum creatinine, serum KIM-1 content, NGAL and inflammatory factors were detected. Renal tissue injury was examined by HE staining; TUNEL staining was used to detect the apoptosis of rat kidney cells. Western blot was performed for the detection of the expression level of MAPK (mitogen-activated protein kinase), Bax, cytochrome C and caspase-3,9 in rat renal tissue. HE staining showed pathological changes in groups group comparing to sham group. BML-111 group had a significant decrease in renal tissue injury. The scores of renal injury in each group were in accordance with the histological changes. The expression level of inflammatory factors in HS group was significantly higher than that in sham group (p<0.05). After BML-111 intervention, the levels of inflammatory factors in renal tissue were significantly lower than those in HS group (p<0.05). Meanwhile, NGAL and KIM-1 also showed the same trend. TUNEL staining showed that compared with sham group, the number of apoptotic cells in renal tissue of HS group increased significantly, and the apoptosis rate of renal tissue cells in group BML-111 decreased significantly. Western blot showed that the expression level of JNK, p38MAPK, and apoptosis-related protein in HS group was significantly increased, whereas the expression level of p38MAPK and JNK in group BML-111 was significantly decreased. BML-111 can reduce the inflammatory response and apoptosis of renal tissue by inhibiting the activation of MAPK signaling pathway in acute renal injury induced by hemorrhagic shock.

Effect of fluorofenidone on renal interstitial fibrosis in rats with unilateral ureteral obstruction

To investigate the effect of fluorofenidone on renal interstitial fibrosis in rats with unilateral ureteral obstruction (UUO) and to observe the effect of fluorofenidone on the expressions of collagen type I (Col I), collagen type III (Col III), α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), platelet derived growth factor (PDGF) in the renal tissues of UUO rats. Methods: Male Sprague-Dawley (SD) rats were randomly divided into a sham-operated group, a UUO group, and a flurofenidone group (n=5). UUO model was induced by ligating the left ureter in rats. The rats were treated with 125 mg/(kg.d) fluorofenidone by gastric gavage in the fluorofenidone group at 24 h before the operation, and the rats were treated with the identical dose of 0.5% sodium carboxyl methyl cellulose (CMC-Na) in the other 2 groups. The rats were sacrificed at 14 days after UUO. Pathological changes of the renal tissue were observed by HE and Masson staining, the mRNA expressions of Col I, Col III, α-SMA, PDGF and CTGF were detected by real-time PCR, and the protein expressions of Col I, Col III, PDGF and CTGF were detected by immunohistochemical staining. Results: The renal interstitial damage index, relative collagen area and mRNA and protein expressions of Col I and Col III in the renal tissues of the rats in the UUO group significantly increased (P<0.05), and fluorofenidone could reduce these indexes (P<0.05). Compared with the sham-operated group, the protein expressions of α-SMA, PDGF, CTGF and the mRNA expressions of PDGF and CTGF in the renal tissues of the rats in the UUO group were increased, but fluorofenidone could decrease the protein expressions of α-SMA, PDGF, CTGF and the mRNA expressions of PDGF and CTGF (P<0.05). Conclusion: Fluorofenidone (125 mg/kg.d) could attenuate renal interstitial fibrosis through inhibition of fibroblast proliferation, myofibroblastic activation, PDGF and CTGF expression.

Downregulation of lncRNA MALAT1 contributes to renal functional improvement after duodenal-jejunal bypass in a diabetic rat model.

Ameliorated renal function has been reported after bariatric surgery, but the mechanisms underlying this phenomenon are not well-studied. To investigate whether the long non-coding RNA (lncRNA) MALAT1 mediates the amelioration of diabetic nephropathy after duodenal-jejunal bypass (DJB) surgery, rats were assigned randomly into four groups: diabetic (DM) group, DM with DJB surgery group, DM with sham surgery group, and healthy control group. Food intake, body weight, oral glucose tolerance test (OGTT), urine albumin excretion rate (UAER), and glomerular filtration rate (GFR) were measured and histological examination of renal sections was performed. For in vitro study, HK-2 cells were cultured under various glucose concentrations following MALAT1 siRNA transfection. Expression levels of MALAT1, SAA3, IL-6, and TNF-α in rat renal tissues or HK-2 cell lines were evaluated by qRT-PCR and/or ELISA. Results showed DJB surgery improved the renal function of diabetic rats, as indicated by ameliorated UAER and GFR and attenuated glomerular hypertrophy. Expression of MALAT1 and its downstream target SAA3 was significantly downregulated in renal tissues after DJB, which in turn decreased the expression of the pro-inflammatory cytokines IL-6 and TNF-α. Knockdown of MALAT1 in HK-2 cell lines further confirmed that expression levels of SAA3, IL-6, and TNF-α were regulated by MALAT1 under both low- and high-glucose conditions. Our findings suggest that MALAT1 is implicated in the improvement of renal function after DJB through regulation of its downstream targets SAA3, IL-6, and TNF-α.

Changes in kidney tissue and effects of erythropoietin after acute heart failure

Impairment of cardiac function causes renal damage. Renal failure after heart failure is attributed to hemodynamic derangement including reduced renal perfusion and increased venous pressure. One mechanism involves apoptosis and is defined as cardiorenal syndrome type 1. Erythropoietin (EPO) is a cytokine that induces erythropoiesis under hypoxic conditions. Hypoxia inducible factor 1 alpha (HIF-1α) plays a regulatory role in cellular response to hypoxia. Protective effects of EPO on heart, kidney and nervous system are unrelated to red blood cell production. We investigated early changes in and effects of EPO on renal tissues of rats with myocardial infarction by morphology and immunohistochemistry. Coronary artery ligation was used to induce myocardial infarction in Wistar rats. Group 1 comprised sham operated rats; groups 2, 3 and 4 included rats after coronary artery ligation that were sacrificed 6 h after ligation and that were treated with saline, 5,000 U/kg EPO or 10,000 U/kg EPO, respectively; group 5 included rats sacrificed 1 h after ligation. Group 2 showed increased renal tubule damage. Significantly less tubule damage was observed in EPO treated groups. EPO and EPO receptor (EPO-R) immunostaining intensities increased slightly for group 5 and became more intense for group 2. EPO and EPO-R immunostaining was observed in the interstitial area, glomerular cells and tubule epithelial cells of EPO treated groups. HIF-1α immunostaining was observed in collecting tubules in the medulla only in group 2. Caspase-3 immunostaining is an indicator of apoptosis. Caspase-3 staining intensity decreased in renal medulla of EPO treated groups. EPO treatment may exert a protective effect on the renal tissues of patients with cardiorenal syndrome.

Effect of treating renal failure with decorin gene therapy.

To explore a new approach for treating renal insufficiency with gene therapy by implanting decorin (DCN)-expressing fibroblasts within the renal tissue of rats with renal failure to neutralize TGF-β1 activity. The 5/6 kidney of the selected male SD rats were removed under aseptic conditions. The rats were grouped randomly after the establishment of the model. There were 10 rats in the sham-operated group (Group A), 10 in the operation control group (without treatment, Group B), 10 in the blank control group [treated with empty vector-transfected fibroblasts (FB (LXSN) cells), Group C], and 10 in the treatment group [treated with FB (LDCNSN) cells, Group D]. The pathological changes of rats including body weight, blood lipids, renal function, and renal histology, were observed. The expression of TGF-β1 and DCN in renal tissue was detected by immunohistochemistry. There were no significant differences in body weight and blood lipids between the groups at 4 weeks after treatment. The levels of blood urea nitrogen and serum creatinine in rats in Group D were significantly decreased compared with those in Group C (p < 0.05). Although the differences were not statistically significant, the levels of those pathological indicators are higher than baseline values. The expression of DCN in renal tissue increased significantly after 4 weeks in rats of Group D and the differences were significant compared with the other groups. There were no significant differences in TGF-β1 expression between any two groups of Group D, B, and C. Furthermore, pathological damage to the renal interstitium of rats in Group D was significantly decreased compared with that of Group B and C. DCN can alleviate fibrosis and delay the progression of renal failure.

Differential JNK, p38 and ERK response to renal injury in a rat model of acute pancreatitis in pregnancy.

The objective of this study was to determine the mechanism of acute renal injury (ARI) in acute necrotizing pancreatitis in late pregnancy (ANPIP). Pregnant Sprague-Dawley rats in the third trimester were used for this study, and an ANPIP model was induced by injecting 5% sodium taurocholate into the biliary pancreatic duct. The rats were randomly divided into three groups: the normal, sham-operated (SO) and acute necrotizing pancreatitis (ANP) groups. Rats were killed at 3, 6, 12h after the operation, and blood, pancreatic and renal tissue samples were harvested. Differences were detected in the physiology, pathology and cellular and molecular responses among the different groups. Serum amylase, lipase, urea and Cr levels were increased in rats with ANPIP. Additionally, expression of phosphorylation p38 and JNK as well as TNF-α and NF-κB were increased in the renal tissues of rats with ANPIP. The expression of phosphorylation ERK was decreased in the renal tissues of rats with ANPIP. Mitogen-activated protein kinases may play an important role in renal injury in rat models of ANPIP.

Beraprost Sodium, a Stable Analogue of PGI2, Inhibits the Renin-Angiotensin System in the Renal Tissues of Rats with Chronic Renal Failure

Chronic renal failure (CRF) is a prolonged kidney condition characterized by decreased kidney function that can eventually develop into total kidney failure. The renin-angiotensin system (RAS) helps to regulate the balance between human bodily fluids and electrolytes. The aim of the present study was to investigate the effects of a prostacyclin analogue (beraprost sodium [BPS]) on the expression of key factors associated with local RAS activities in the renal tissues of rats with CRF. After a CRF rat model was successfully established, the levels of BUN, SCr, phosphorus, and calcium were detected by an automatic biochemistry analyzer. Furthermore, the activities of malondialdehyde (MDA) and superoxide dismutase (SOD) in rat renal tissues were measured using a colorimetric method, while the activity of angiotensin-converting enzyme (ACE) was determined by ultraviolet (UV) spectrophotometry. In situ hybridization was employed to determine the expression of angiotensin II type 1 receptor (AT). Finally, the positive expression rates of cells expressing important apoptotic proteins (Bax and Bcl-2) were determined, and the protein and mRNA levels of phosphatidylinositol 3-kinase (AKT) and key factors involved in the RAS (AT1, AT2, angiotensin ACE and angiotensinogen [AGT]) were evaluated by RT-qPCR and western blot analysis. Initial observations revealed that treatment with BPS decreased the levels of BUN, SCr and phosphorus but increased calcium levels in the renal tissues of CRF rats. Additionally, BPS reduced the levels of MDA while increasing the levels of SOD, ACE activity, and AT1 expression in the renal tissues of CRF rats. BPS inhibited glomerular hypertension and hyperfiltration; increased the mRNA and protein levels of AKT and AT2; and decreased the mRNA and protein levels of AT1, AGT, and ACE in the renal tissues of CRF rats. The results of this study demonstrate that BPS, a PGI2 analogue, inhibits the expression of key factors involved in the local RAS, resulting in a delay in the occurrence and development of CRF. The key findings of the present study ultimately highlight the potential of this PGI2 analogue as a promising therapeutic strategy for treating CRF.

Cadmium-induced hematological, renal, and hepatic toxicity: The amelioration by spirulina platensis

Background: spirulina platensis (SP) is known as a valuable additional food and therapeutic agent. Objective: We investigate the protective effect of SP on cadmium (Cd)-induced hematological, renal and hepatic toxicity in rats. Materials and Methods: The rats were divided into four groups. Group 1: received saline orally. Group 2: treated with SP orally for 28 days. Groups 3: treated with CdCl2for 28 days. Group 4: treated with CdCl2and SP for 28 days. Renal and hepatic damages were evaluated by investigating the renal and hepatic functions, oxidative markers, and histopathological changes. Results: There was a statistically significant (P ≤ 0.05) increase in Cd concentration in the liver and kidneys of G3 and a significant decrease with the administration of SP in G4. In rat hepatic and renal tissues, superoxide dismutase and catalase were significantly reduced while malondialdehyde (MDA) was significantly increased and significant decrease in RBC count, hemoglobin concentration, and hematocrit in Group 3 when compared to G1 and G2 (P ≤ 0.05), with improvements of these parameters in G4 when compared to G3. A significant increase was observed in plasma MDA level in Group 3 compared to control group and SP-treated group, and it was significantly decreased in G4 compared to G3. Conclusion: It can be concise that accumulation of Cd in liver and kidneys of rats is associated with remarkable alterations enzymatic activities of the antioxidant system. Our data suggested that lipid peroxidation was associated with Cd toxicity in both liver and kidney tissues. The oxidative damage in kidney and liver of rats induced by Cd is protected by SP.

Sublytic C5b-9 Induces Glomerular Mesangial Cell Apoptosis Through miR-3546/SOX4/Survivin Axis in Rat Thy-1 Nephritis

Background/Aims: The activation of complement system and the formation of C5b-9 complex have been confirmed in the glomeruli of patients with mesangioproliferative glomerulonephritis (MsPGN). However, the role and mechanism of C5b-9-induced injury in glomerular mesangial cell (GMC) are poorly understood. Rat Thy-1N is an animal model for studying MsPGN. It has been revealed that the attack of C5b-9 to the GMC in rat Thy-1N is sublytic, and sublytic C5b-9 can cause GMC apoptosis, but the underlying mechanism is not fully elucidated. To explore the role and regulatory mechanism of C5b-9 in MsPGN lesion, we used rat Thy-1N model and first detected the change of microRNA (miRNA) profiles both in Thy-1N rat renal tissues (in vivo) and in the cultured GMCs with sublytic C5b-9 stimulation (in vitro). Then we determined the effect of miR-3546, which increased both in vivo and in vitro, on GMC apoptosis upon sublytic C5b-9 as well as the involved mechanism. Methods: Rat Thy-1N model was established and GMCs were treated with sublytic C5b-9. The rat renal cortex and the stimulated GMCs were obtained for miRNA microarray detection. Subsequently, the increased miRNAs were verified by real-time PCR. Meanwhile, to ascertain the ability of some miRNAs to upregulate cleaved caspase 3 and induce GMC apoptosis, the corresponding miRNA mimics were transfected into GMCs, followed by western blotting (WB) and flow cytometry mesurement. Thereafter, the miR-3546-targeted gene (SOX4) was predicted using bioinformatics approaches, and SOX4 expression in Thy-1N tissues and in the GMCs upon sublytic C5b-9 stimulation or miR-3546 mimic/inhibitor transfection were detected using real-time PCR and WB. To prove that miR-3546 can affect SOX4 gene transcription and SOX4 can regulate survivin expression, dual luciferase reporter assay, real-time PCR, WB and chromatin immunoprecipitation (ChIP) assays were performed. Furthermore, the role of miR-3546/SOX4/survivin axis in the GMC apoptosis induced by sublytic C5b-9 was examined using WB and flow cytometry. Results: Compared with normal renal tissues and untreated GMCs, there were 43 and 62 upregulated miRNAs (> 2-fold) in Thy-1N tissues and sublytic C5b-9-stimulated GMCs respectively. A total of 17 miRNAs were increased both in vivo and in vitro, 11 of which were validated by real-time PCR. Among them, miR-3546 could markedly promote GMC apoptosis and inhibit SOX4 or survivin expression in response to sublytic C5b-9, and either SOX4 or survivin overexpression markedly rescued the GMC apoptosis mediated by miR-3546 mimic. Additionally, SOX4 overexpression could reverse the survivin suppression by miR-3546 mimic, and SOX4 could bind to survivin promoter (-1,278 to -853 nt) and activate survivin gene transcription. Conclusion: MiR-3546/ SOX4/survivin axis has a promoting role in the GMC apoptosis triggered by sublytic C5b-9, and our findings may provide a new insight into the pathogenesis of rat Thy-1N and human MsPGN.

Emodin ameliorates renal fibrosis in rats via TGF-β1/Smad signaling pathway and function study of Smurf 2.

Emodin is a natural active component extracted from Chinese herbs. In this study, we investigated the therapeutic effect of emodin on surgery-induced renal fibrosis in rat. Moreover, the function of Smad ubiquitination regulatory factor 2 (Smurf 2) was further studied in vitro. The renal fibrosis rat model was established via 5/6 renal mass reduction. The histopathological abnormalities of renal tissues in rats were tested via staining method and microscopic examination. Renal function indicators, the serum creatinine, blood urea nitrogen and total urinary protein were measured via spectrophotometric method. The renal tissues were tested via Western blotting and real-time quantitative PCR. Moreover, Smurf 2 protein expression under different conditions and its regulatory function in vitro was measured via Western blotting. Our results showed that the histopathological abnormalities, the decrease in rat body weight and the abnormal renal function caused by renal fibrosis were improved by emodin. Further, mRNA expression of TGF-β1 was decreased by emodin. Furthermore, extracellular matrix (ECM) components as well as TGF-β1/Smad signaling-related Smurf 2 were decreased by emodin both in vivo and in vitro. The protein level of mothers against decapentaplegic homolog 7 (Smad7) was up-regulated. In addition, ECM components were increased by Smurf 2 over-expression and these effects were weakened by emodin co-treatment in vitro. Emodin showed an anti-fibrosis effect in surgery-induced renal fibrotic rats. And this effect was potentially achieved via down-regulating expressions of TGF-β1 and Smurf 2 and up-regulating Smad7 expression.

Astragaloside IV prevents kidney injury caused by iatrogenic hyperinsulinemia in a streptozotocin‑induced diabetic rat model.

Diabetic patients are able to manage their blood glucose with exogenous insulin but, ultimately, remain at risk of diabetic nephropathy (DN). Long‑term use of insulin may lead to iatrogenic hyperinsulinemia, which has been suggested to cause kidney injury. However, there are no effective interventions for iatrogenic hyperinsulinemia leading to kidney damage. In the present paper, the hypothesis that astragalosideIV (AS‑IV), a novel saponin purified from Astragalus membranaceus (Fisch) Bunge, may prevent DN in iatrogenic hyperinsulinemic diabetic rats through antioxidative and anti‑inflammatory mechanisms was investigated. Diabetes was induced with streptozotocin (STZ) (55mg/kg) by intraperitoneal injection in rats. At 1week following STZ injection, the diabetic rats were treated with Levemir subcutaneously for4weeks. Diabetic rat insulin levels >30µU/ml were considered as iatrogenic hyperinsulinemia. Rats were divided into six groups (n=8 per group): Iatrogenic hyperinsulinemic rats, and iatrogenic hyperinsulinemic rats treated with Tempol and AS‑IV at 2.5, 5 and 10mg/kg/day, intragastric infusion, for 12weeks. The normal rats were used as a non‑diabetic control group. AS‑IV ameliorated albuminuria, mesangial cell proliferation, basement membrane thickening and podocyte foot process effacement in iatrogenic hyperinsulinemic rats. In iatrogenic hyperinsulinemic rat renal tissues, malondialdehyde, interleukin‑1β(IL‑1β), tumor necrosis factor‑α (TNF‑α), typeIV collagenand laminin levels were increased, whereas glutathione peroxidaseand superoxide dismutase activity levels were decreased. Nicotinamide adenine dinucleotide phosphate oxidase4 expression and extracellular signal‑regulated kinase1/2(ERK1/2) activation were upregulated, and canonical transient receptor potential cation channel6 (TRPC6) protein expression was downregulated. However, all these abnormalities were attenuated by AS‑IV. These findings suggested that AS‑IV prevented rat kidney injury caused by iatrogenic hyperinsulinemia by inhibiting oxidative stress, IL‑1β and TNF‑α overproduction, downregulating ERK1/2 activation, and upregulating TRPC6 expression.

Tadalafil protector effect during ischemia-reperfusion in rats.

To evaluate histological parameters in rat renal tissue after tadalafil use during hot ischemia for 45 minutes and reperfusion for 24 hours. Twenty rats were divided into 2 groups. In the experimental group 10 mg/kg of tadalafil was used per gavage before the procedure. All cases underwent left partial nephrectomy, followed by 45 minutes of warm ischemia. Left nephrectomy of the remaining kidney was performed after 24 hours from the initial procedure. The histological parameters analyzed were: detachment of tubular cells, accumulation of desquamated cells in the proximal tubule, loss of brush border, tubular cylinders, interstitial edema, leukocyte infiltration, capillary congestion, vacuolization, tubular dilatation, necrosis and collapse of the capillary tuft. Two rats from each group died and were excluded from the study. Tadalafil significantly reduced leukocyte infiltration (p = 0.036). The remaining histological parameters did not show statistical difference between the groups. The use of tadalafil during warm ischemia and reperfusion demonstrates statistically significant reduction of leukocyte infiltration in the renal interstitium.

Thymosin \u03b24 alleviates renal fibrosis and tubular cell apoptosis through TGF-\u03b2 pathway inhibition in UUO rat models

BackgroundThymosin β4 (Tβ4) is closely associated with the cytoskeleton, inflammation, wound healing, angiogenesis, apoptosis, and myocardial regeneration, but the effects of Tβ4 treatment on chronic renal tubular interstitial fibrosis (CRTIF) are poorly known. This study aimed to examine the effects of Tβ4 on the renal apoptosis and the expression of transforming growth factor (TGF-β), E-cadherin, and α-smooth muscle actin (α-SMA) in CRTIF rat models.MethodsMale SD rats were randomized into four groups (sham group, unilateral ureteral obstruction (UUO) group, UUO + low-dose Tβ4 group, and UUO + high-dose Tβ4 group). The pathological changes of kidney tissue and its function were assessed two weeks after UUO. In renal interstitial tissue,TGF-β, E-cadherin and α-SMA expression was detected by western blot. In tubular epithelial cells, E-cadherin and α-SMA expression was detected using Real-time qPCR and western blot. Cell apoptosis of rat renal interstitial tissue and tubular epithelial cells was evaluated by immunofluorescence and western blot.ResultsTwo weeks after UUO, no differences in blood urea nitrogen and creatinine were observed between the four groups (P > 0.05). Compared to the UUO group, Tβ4 treatment decreased the 24-h proteinuria (P < 0.001) and reduced the area of pathological change (P < 0.01); this effect was more apparent in the UUO + high-dose Tβ4 group. Compared to the UUO group, a significant decrease in TGF-β and α-SMA protein expression was observed in the high-dose Tβ4 group. The level of E-cadherin protein was lower in the UUO group than the Tβ4 groups, and high-dose Tβ4 treatment further increased E-cadherin expression and improved cell apoptosis in the renal interstitial tissue. Analysis of in vitro tubular epithelial cells showed that α-SMA mRNA and protein expression decreased, while E-cadherin mRNA and protein expression increased by Tβ4 treatment. Similarly, these changes were more significant in the UUO + high-dose Tβ4 group. Tβ4 treatment improved the apoptosis of In vitro tubular epithelial cells compared with pure TGF-β stimulation, and equally, the decrease of apoptosis was more apparent in the TGF-β + high-dose Tβ4 group.ConclusionsTβ4 treatment might alleviate the renal fibrosis and apoptosis of tubular epithelial cells through TGF-β pathway inhibition in UUO rats with CRTIF.

The protective effect of rabbit serum paraoxonase-1 on the renal injury induced by dichlorvos in rats

Objective To assess the protective effect of rabbit serum paraoxonase-1 (PON-1) on renal injury induced by dichlorvos in rats. Methods Totally 30 healthy S-D rats were randomly divided into 5 groups : control group ( group A, n=6), exposure group ( group B, n=6), PON-1 pretreatment group (group C, n=6), traditional atropine, pralidoxime treatment group(group D, n=6) and combination therapy group (group E, n=6). The rats of group A were given normal saline in equal volume of dichlorvos injected into abdominal cavity to make a false model of dichlorvos poisoning. In rats of groups B, C, D and E, 9 mg/kg dichlorvos was administered. In rats of groups C and E, PON-1 4 500 units/kg was injected into vein of the tails half an hour before dichlorvos administration. After dichlorvos exposure, rats in group D and E were treated with 45 mg/kg iodoprofen and 10 mg/kg atropine by intraperitoneal injection. The activity of blood urea nitrogen (BUN) was assayed with urease. Serum creatinine (Cr) were measured by picric acid colorimetry. Serum Cys-C, KIM-1 and NAG in urine were determined by ELISA. Ultrastructural changes in renal tissues of rats were examined by light microscopy. The differences in laboratory findings between groups were compared. Results The creatinine level in group B was significantly higher than that in other groups (P<0.05). The levels of Cys-C, KIM-1 and NAG in group B and group D were significantly higher than those in group A (P<0.01). But there were no significant differences in above biomarkers among group C, group E and group A. There were no significant differences in above biomarkers between group B and group D. In group B, inflammatory cells infiltrated extensively in renal tissues and, the renal cells were congested and edematous, the lumen was obliterated and the border of the brush disappeared. The tubular structures were not clearly distinct found in group B, but edema and inflammatory cell infiltration with lesser degree were found in group D than those in dichlorvos exposure groups. The clearly distinct structure of the tube without completely occluded lumen in group D, and the most serious lesions were found in distal convoluted tubules. In group C, and group E, there were only mild congestion and edema without significant cell degeneration and necrosis. In group A, the structure of renal tubular epithelium was clearly distinct with brush-shaped margin, and without tubular or necrotic cell debris in the lumen. Conclusion The rabbit serum PON-1 can protect the renal tissue of rats after dichlorvos exposure. Key words: Dichlorvos; Paraoxonase -1; Renal injury; Protective effect; Rats

Fucoidan elevates surface organic cation transporter 2 expression via upregulation of protein kinase A in uric acid nephropathy.

Uric acid nephropathy (UAN) is caused by excessive uric acid, and is a key risk factor for uric acid nephrolithiasis, gouty arthritis, renal diseases and cardiovascular diseases. The present study aimed to evaluate the protective effect of fucoidan, a sulfated polysaccharide component of brown algae, on UAN and to elucidate the underlying molecular mechanism. A rat model of UAN was induced by adenine treatment, and rats were then randomly assigned to control, model or fucoidan treatment groups. Hematoxylin and eosin staining of the kidney tissues of rats with UAN was subjected to conventional morphological evaluation. Cellular infiltrate in the tubules, atrophic glomeruli, tubular ectasia, granuloma hyperplasia focal fibrosis and accumulated urate crystals in the tubules of UAN rat renal tissues were observed. These symptoms of kidney damage were reduced in the fucoidan treatment group. Periodic acid methenamine silver-Masson staining was performed and the results indicated that renal interstitial fibrosis was reduced among renal tissues from the fucoidan treatment group compared with the model group. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling staining revealed a lower proportion of apoptotic nuclei in the kidneys of the fucoidan treatment group compared with the model group. Protein kinase A (PKA) 2β and phosphorylated PKA 2β protein levels were significantly elevated in renal tissues of the fucoidan treatment group compared with the model group (P<0.05 and P<0.01, respectively), suggesting that PKA expression was upregulated by fucoidan. Immunohistochemistry staining of PKA in rat renal tissues demonstrated increased expression of PKA. The surface organic cation transporter 2 (OCT2) level was significantly increased by fucoidan treatment compared with the model group (P<0.01), with no significant change in total OCT2 level. COS-7 cells ectopically expressing OCT2 were established. It was indicated that fucoidan was able to activate PKA and upregulate surface OCT2 in OCT2-expressing COS-7 cells. This further demonstrated that upregulation of surface OCT2 expression in OCT2-expressing cells was induced by PKA upregulation. In conclusion, fucoidan upregulated surface OCT2 expression in renal tissues to alleviate the symptoms of UAN via upregulated expression of PKA.