Ulinastatin inhibits unilateral ureteral obstruction-induced renal interstitial fibrosis in rats via transforming growth factor β (TGF-β)/Smad signalling pathways

The Protective Effect of Zebularine, an Inhibitor of DNA Methyltransferase, on Renal Tubulointerstitial Inflammation and Fibrosis

Renal fibrosis, the final pathway of chronic kidney disease, is caused by genetic and epigenetic mechanisms. Although DNA methylation has drawn attention as a developing mechanism of renal fibrosis, its contribution to renal fibrosis has not been clarified. To address this issue, the effect of zebularine, a DNA methyltransferase inhibitor, on renal inflammation and fibrosis in the murine unilateral ureteral obstruction (UUO) model was analyzed. Zebularine significantly attenuated renal tubulointerstitial fibrosis and inflammation. Zebularine decreased trichrome, α-smooth muscle actin, collagen IV, and transforming growth factor-β1 staining by 56.2%. 21.3%, 30.3%, and 29.9%, respectively, at 3 days, and by 54.6%, 41.9%, 45.9%, and 61.7%, respectively, at 7 days after UUO. Zebularine downregulated mRNA expression levels of matrix metalloproteinase (MMP)-2, MMP-9, fibronectin, and Snail1 by 48.6%. 71.4%, 31.8%, and 42.4%, respectively, at 7 days after UUO. Zebularine also suppressed the activation of nuclear factor-κB (NF-κB) and the expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, by 69.8%, 74.9%, and 69.6%, respectively, in obstructed kidneys. Furthermore, inhibiting DNA methyltransferase buttressed the nuclear expression of nuclear factor (erythroid-derived 2)-like factor 2, which upregulated downstream effectors such as catalase (1.838-fold increase at 7 days, p < 0.01), superoxide dismutase 1 (1.494-fold increase at 7 days, p < 0.05), and NAD(P)H: quinone oxidoreduate-1 (1.376-fold increase at 7 days, p < 0.05) in obstructed kidneys. Collectively, these findings suggest that inhibiting DNA methylation restores the disrupted balance between pro-inflammatory and anti-inflammatory pathways to alleviate renal inflammation and fibrosis. Therefore, these results highlight the possibility of DNA methyltransferases as therapeutic targets for treating renal inflammation and fibrosis.

Recent research progress on the role of ulinastatin in chronic kidney disease

With the continuous improvement in living standards, lifestyle changes and ageing of the population, the prevalence of chronic kidney disease (CKD) has increased significantly, and its prevention and treatment have become important public health issues worldwide. Renal fibrosis is the main pathological basis of CKD progression to end-stage renal disease. Preventing the progression of renal fibrosis has always been the focus of clinical and scientific research. Ulinastatin is a serine protease inhibitor that is found in human blood and urine and inhibits the inflammatory response, regulates immunity and improves the microcirculation. It is widely used in patients with sepsis and septic shock in clinical practice. Recent studies have shown that ulinastatin can also play an important anti-fibrotic and organ protective role and can provide a new therapeutic hope for CKD patients. This review mainly introduced the research progress of UTI in inflammation, oxidative stress, apoptosis, acute kidney injury and renal fibrosis. By investigating the role of ulinastatin in CKD, we can determine the possible mechanisms for its renal protection and improvement of renal fibrosis, so as to provide new ideas for the treatment of CKD.

Stevioside inhibits unilateral ureteral obstruction-induced kidney fibrosis and upregulates renal PPARγ expression in mice

This study aimed to examine the inhibitory effect of stevioside on unilateral ureteral obstruction (UUO)-induced kidney fibrosis. The UUO mice were daily given 50-100 mg/kg stevioside by gavage for 14 days after the operation. The results showed that stevioside decreased the levels of blood urea nitrogen and renal hydroxyproline, severity of kidney fibrosis, and expressions of renal collagen I/III and α-smooth muscle actin proteins. Importantly, stevioside increased the expressions of renal peroxisome proliferator-activated receptor γ (PPARγ) and Smad7 proteins and level of renal glutathione peroxidase, decreased the expressions of renal nuclear factor kappa B (NF-κB), signal transducer and activator of transcription 3 (STAT3), p-STAT3, transforming growth factor-β1 (TGF-β1), Smad2/3, and p-Smad2/3 proteins, suggesting that the antifibrotic mechanisms are related to the activation of PPARγ and subsequent downregulations of NF-κB-mediated STAT3 and TGF-β1 expressions and inhibition of Smad-mediated signaling pathway. These findings provide an applied perspective of stevioside for kidney fibrosis. PRACTICAL APPLICATIONS: Stevioside is widely used in food products as a sweetener, and it has many beneficial biological effects, including antidiabetes, antihypertension, and renal protective action. Here, we provide a novel potential application of stevioside in the prevention and treatment of kidney fibrosis.

Ulinastatin enhances autophagy against radiation-induced lung injury in mice

Background

To investigate the enhancement of autophagy by ulinastatin for protecting against radiation-induced lung injury (RILI) in mice.

Methods

Forty C57BL/6 mice were equally divided into (I) control (C), (II) irradiation (R), (III) ulinastatin (U), (IV) 3-methyladenine (3-MA) (M), and (V) ulinastatin plus 3-MA (U+M) groups. Three mice in each group were infected with adeno-associated virus (AAV) carrying green fluorescent protein (GFP)-1A/1B-light chain 3 (GFP-LC3) in the lung for the marker of autophagy. All mice in R, U, M and U+M groups were given chest irradiation (1 Gy/min, 12 min), following injection with normal saline in C and U groups, ulinastatin (500,000 IU/kg·d, i.p., 7 d) in U group, 3-MA (10 mg/kg·d, i.p., 7 d) in M group, and ulinastatin plus 3-MA in U+M group. The effects of ulinastatin on lung injury and autophagy were evaluated by electron microscope (EM), immunohistochemistry, mRNA expression levels of collagen alpha-1 (COL1A1), collagen alpha-2 (COL1A2), α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGF-β1), and protein levels of LC3, α-SMA, COL1A2, TGF-β1, matrix metalloproteinase-2 (MMP-2) and MMP-9.

Results

EM observation revealed that the radiation caused the injury of type I and II alveolar epithelial cells, which was improved by ulinastatin treatment associated with increased the numbers of autophagosomes. GFP-LC3 signals was significantly enhanced by ulinastatin detected by immune histochemical tests. At transcriptional and/or translational levels, ulinastatin significantly enhanced the expression levels of TGF-β1 and LC3 but reduced COL1A1, COL1A2, α-SMA, MMP-2 and MMP-9 after radiation-induced RILI.

Conclusions

Ulinastatin reduces RILI by enhancing autophagy, which might be a potential therapeutic drug in the protection against RILI.

Ulinastatin Inhibits the Formation and Progression of Experimental Abdominal Aortic Aneurysms

AIMS

Aortic mural inflammatory damage takes a vital part in abdominal aortic aneurysm (AAA). Recently, ulinastatin (UTI) has attracted attention for its anti-inflammatory function. Our study aimed to evaluate potential influences of UTI on experimental AAA.

METHODS

A mouse model of AAA was induced by infusion of porcine pancreatic elastase (PPE) into the abdominal aorta. Mice were treated with UTI (50,000 U/kg/day i.p.) beginning either immediately or on the 4th day after PPE infusion, with treatment being continued until the 14th day. UTI effects were assessed by aortic diameter measurements and aortic histopathological analysis.

RESULTS

Significant and time-dependent aortic diameter enlargement persisted in the control mice from day 0. In the UTI group, aortic diameter increased, and depletion of aortic mural smooth muscle cells and elastin was significantly -attenuated. Simultaneously, mural CD68+ macrophages, CD8+ T-cell and B220+ B-cell density, as well as neoangiogenesis were suppressed by UTI. In addition, delayed UTI treatment could still effectively limit aneurysm expansion.

CONCLUSIONS

UTI treatment limits the formation and growth of experimental AAA, and UTI may be a potential treatment for early AAA disease.

Acupuncture attenuates renal interstitial fibrosis via the TGF‑β/Smad pathway

Acupuncture is one of the most useful tools in complimentary medicine, and has demonstrated potential value for treating chronic renal failure (CRF). However, the underlying mechanisms for its therapeutic effect remain unknown. In the present study, the effects of acupuncture on renal interstitial fibrosis (RIF) were explored in a rabbit model of CRF. Rabbits were assigned to the following five groups: sham, model, losartan potassium (Posi), acupuncture (Acup) and acupuncture+inhibitor (Acup+Inhib) groups. The CRF rabbits were administered a drug or/and acupuncture on Shenshu, Mingmen and Pishu. The body weights, urine protein, serum creatinine (SCr) and blood urea nitrogen (BUN) levels of the rabbits were measured. Transforming growth factor β (TGF-β), integrin-linked kinase (ILK) and Smad3 expression were detected by qRT-PCR. Tumor necrosis factor-α (TNF-α) and endothelial nitric oxide synthase (eNOS) expression were analyzed by western blot methods. The concentrations of TGF-β, IL-8, TNF-α and IL-1β in blood serum were detected using ELISA kits. In addition, pathological characteristics of the rabbit tissues were evaluated by H&E and Masson's trichrome staining methods, and TGF-β expression was detected by immunohistochemistry (IHC) assays. Results showing decreased body weights and increased urine protein, SCr and BUN levels confirmed that the CRF model had been successfully constructed. It was also found that acupuncture significantly reduced the levels of TNF-α, Smad3, ILK and TGF-β expression, dramatically decreased the concentrations of TGF-β, IL-8, TNF-α and IL-1β in blood serum, and significantly increased eNOS expression in the CRF model rabbits by affecting the TGF-β/Smad signaling pathway. In addition, it was demonstrated that acupuncture could relieve RIF by affecting the TGF-β/Smad pathway. These observations indicate that acupuncture may be useful for treating CRF, and suggest the TGF-β/Smad pathway as a target for CRF therapy.

Nimbolide ameliorates unilateral ureteral obstruction-induced renal fibrosis by inhibition of TGF-β and EMT/Slug signalling

Chronic kidney disease (CKD) involves interstitial fibrosis as an underlying pathological process associated with compromised renal function irrespective of etiological cause of the injury. The transforming growth factor-β (TGF-β) plays a pivotal role in progression of renal fibrosis. TGF-β transduces its downstream signalling by phosphorylation of smad2/3 and also regulates epithelial-mesenchymal-transition (EMT), a program centrally involved in activation of fibroblasts. Renal fibrosis was induced in Swiss albino mice by unilateral ureteral obstruction of animals. Kidney tissues were evaluated for fibrotic protein expression by western blot and immunohistochemistry. The administration of nimbolide (NB) to UUO animals reduced the oxidative stress, expression of ECM proteins, TGF-β, p-smad and EMT program. Further, NB administration also improved histoarchitecture of obstructed kidney and reduced the collagen deposition in kidney. Our results provided compelling evidence to support antifibrotic activity of NB by reduction in oxidative stress, TGF-β, and EMT program in fibrotic kidney. The administration of NB in animals blunted the UUO-induced renal injury, inflammation and reduced fibrogenesis in obstructed kidney.

Inhibition of p300/CBP-Associated Factor Attenuates Renal Tubulointerstitial Fibrosis through Modulation of NF-kB and Nrf2

p300/CBP-associated factor (PCAF), a histone acetyltransferase, is involved in many cellular processes such as differentiation, proliferation, apoptosis, and reaction to cell damage by modulating the activities of several genes and proteins through the acetylation of either the histones or transcription factors. Here, we examined a pathogenic role of PCAF and its potential as a novel therapeutic target in the progression of renal tubulointerstitial fibrosis induced by non-diabetic unilateral ureteral obstruction (UUO) in male C57BL/6 mice. Administration of garcinol, a PCAF inhibitor, reversed a UUO-induced increase in the renal expression of total PCAF and histone 3 lysine 9 acetylation and reduced positive areas of trichrome and α-smooth muscle actin and collagen content. Treatment with garcinol also decreased mRNA levels of transforming growth factor-β, matrix metalloproteinase (MMP)-2, MMP-9, and fibronectin. Furthermore, garcinol suppressed nuclear factor-κB (NF-κB) and pro-inflammatory cytokines such as tumor necrosis factor-α and IL-6, whereas it preserved the nuclear expression of nuclear factor erythroid-derived 2-like factor 2 (Nrf2) and levels of Nrf2-dependent antioxidants including heme oxygense-1, catalase, superoxide dismutase 1, and NAD(P)H:quinone oxidoreductase 1. These results suggest that the inhibition of inordinately enhanced PCAF could mitigate renal fibrosis by redressing aberrant balance between inflammatory signaling and antioxidant response through the modulation of NF-κB and Nrf2.

Burns: Pathophysiology of Systemic Complications and Current Management

As a result of many years of research, the intricate cellular mechanisms of burn injury are slowly becoming clear. Yet, knowledge of these cellular mechanisms and a multitude of resulting studies have often failed to translate into improved clinical treatment for burn injuries. Perhaps the most valuable information to date is the years of clinical experience and observations in the management and treatment of patients, which has contributed to a gradual improvement in reported outcomes of mortality. This review provides a discussion of the cellular mechanisms and pathways involved in burn injury, resultant systemic effects on organ systems, current management and treatment, and potential therapies that we may see implemented in the future.

Quantitative peptidomics of endogenous peptides involved in TGF-β1-induced epithelial mesenchymal transition of renal epithelial cells

TGF-β1 is a key fibrotic factor mediating epithelial mesenchymal transition (EMT) of epithelial cells through various signaling pathways. However, roles of proteolytic cleavage and endogenous peptide dynamics in TGF-β1-induced EMT remain unknown. We therefore performed quantitative peptidomics of TGF-β1-induced EMT in renal tubular epithelial cells. The acquired mesenchymal characteristics were confirmed, including morphological change (from cobblestone-like to fibroblast-like), decreased epithelial marker (ZO-1), and increased mesenchymal marker (vimentin). Quantitative peptidomics using stable isotope labeling revealed significantly altered levels of 70 unique endogenous peptides (derived from internal and C-terminal parts of 39 unique precursor proteins) after EMT induction. Interestingly, the majority of these peptides were derived from non-short-lived proteins, and analysis of P1 position revealed predominance of hydrophobic residues, suggesting that these endogenous peptides were generated mainly from proteasome cleavage. This hypothesis was confirmed by treating the cells with MG132 (a proteasome inhibitor), which provided almost identical endogenous peptide pattern as of the TGF-β1-treated cells. Moreover, validation assay showed marked reduction of proteasome peptidase activity in both TGF-β1-treated and MG132-treated cells. This is the first peptidome dataset that provides several novel aspects of mechanisms for TGF-β1-induced EMT. Our data also suggest that TGF-β1 exerts inhibitory effect against proteasome activity during EMT induction.

Therapeutic effect of ulinastatin on pulmonary fibrosis via downregulation of TGF‑β1, TNF‑α and NF‑κB

Pulmonary fibrosis is a chronic, progressive, lethal lung disease characterized by alveolar cell necrosis and dysplasia of interstitial fibrotic tissue, resulting in loss of lung function and eventual respiratory failure. Previously, glucocorticoid drugs were used to treat this lung disorder. However, positive responses were recorded in less than half of treated patients and the cytotoxicity caused by high dosage treatment is still a concern. The present study investigated whether ulinastatin, a typical urinary trypsin inhibitor that mitigates numerous inflammatory responses, could be a treatment option for lung fibrosis. The results demonstrated that ulinastatin had the ability to ameliorate interstitial fibrosis and alveolar exudates and to protect against lung diseases induced by smoke, irradiation or silica particles. The mechanism of ulinastatin resulted in the downregulation of inflammatory cascades: Transforming growth factor-β1, tumor necrosis factor-α and nuclear factor-κB, as demonstrated by western blotting and ELISA. Ulinastatin treatment with a high dose (100,000 U/kg body weight/day) resulted in an attenuated inflammatory response, and inhibited fibrosis formation in lungs, suggesting that ulinastatin may become a part of a clinical therapeutic strategy.

Ulinastatin inhibits renal tubular epithelial apoptosis and interstitial fibrosis in rats with unilateral ureteral obstruction

The effect of ulinastatin (UTI) on renal tubular epithelial apoptosis and interstitial fibrosis in rats with unilateral ureteral obstruction (UUO) was investigated. A total of 18 male Wistar rats were randomly divided into the following 3 groups: The Sham group (n=6), the UUO group (n=6), and the UTI group (n=6). In the UUO and UTI groups, the left ureter was ligated to establish a UUO model. Starting from day 1 after surgery, an intervention treatment was performed using normal saline (1 ml/kg/d) and UTI (40,000 unit/kg/d). On day 7 after surgery, 6 rats from each group were sacrificed. In the Sham group, the left ureter was only freed, not ligated; after 7 days of abdominal closure, all of the rats were sacrificed. Blood samples were collected prior to sacrificing the animals to measure the blood urea nitrogen (BUN) and serum creatinine (Scr). The incidence of renal interstitial lesions on the obstruction side was observed by hematoxylin and eosin, and Masson staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and immunohistochemical detection of apoptosis regulator Bax (Bax), apoptosis regulator Bcl-2 (Bcl-2) and caspase-3 were performed to observe the presence of renal tubular epithelial cell apoptosis. The UTI did not have a significant influence on the mouse BUN and Scr levels in any of the groups (P>0.05). Compared with that in the Sham group, renal tissue injury in the UUO group was significantly aggravated with renal tubular dilation, epithelial cell atrophy, renal interstitial inflammatory cell infiltration and fibrous tissue hyperplasia (P<0.01). Furthermore, the renal tubular epithelial TUNEL+ cell number and Bax and caspase-3 levels were increased, and the expression of Bcl-2 was decreased (P<0.01). Following the UTI treatment, the renal interstitial injury at the obstruction side was significantly attenuated (P<0.05), the renal tubular epithelial TUNEL+ cell number, and Bax and caspase-3 levels significantly decreased, and the expression of Bcl-2 was restored (P<0.05). UTI inhibited renal tubular epithelial apoptosis and interstitial fibrosis in UUO rats.

Treatment combining aliskiren with paricalcitol is effective against progressive renal tubulointerstitial fibrosis via dual blockade of intrarenal renin

The aim of this study was to assess any potential additive effects of a treatment combining aliskiren with paricalcitol on reducing renal fibrosis. C57BL/6J mice were treated individually with aliskiren and/or paricalcitol until 7 days after initiation of unilateral ureteral obstruction (UUO).In obstructed kidneys of UUO mice, monotherapy with aliskiren or paricalcitol significantly attenuated interstitial fibrosis, collagen IV accumulation, and α-smooth muscle actin- and terminal deoxynucleotidyl transferase-mediated biotin nick end-labeling-positive cells. The combination treatment showed additive efficacy in inhibition of these parameters. Renal NADPH oxidase (Nox)1 and Nox2 were significantly decreased by aliskiren or paricalcitol alone or in combination, while renal Nox4 expression was significantly reduced by paricalcitol mono- or combination treatment. Increased levels of p-Erk and p-p38 MAPK, and NF-κB in UUO kidneys were also significantly reduced by either aliskiren or paricalcitol treatment alone or in combination. Aliskiren or paricalcitol monotherapy significantly reduced the expression of (pro)renin receptor in UUO kidneys. In addition, aliskiren tended to augment renin expression in UUO kidneys, but paricalcitol reduced its expression level. The combination treatment effectively blocked both (pro)renin receptor and renin expression induced by aliskiren, and resulted in a further reduction of the renal expression of angiotensin II AT1 receptor. Aliskiren failed to increase the expression of vitamin D receptor in UUO kidneys, but the combination treatment restored its expression level. Taken together, a treatment combining aliskiren with paricalcitol better inhibits UUO-induced renal injury. The mechanism of this synergy may involve more profound inhibition of the intrarenal renin-angiotensin system.

Alpha-lipoic acid ameliorates the epithelial mesenchymal transition induced by unilateral ureteral obstruction in mice

The epithelial-to-mesenchymal transition (EMT) is one of mechanisms that induce renal interstitial fibrosis. Understanding EMT in renal fibrosis has important therapeutic implications for patients with kidney disease. Alpha-lipoic acid (ALA) is a natural compound with antioxidant properties. Studies for ALA are performed in acute kidney injury with renal tubular apoptosis, renal inflammation, and oxidative stress. We investigated the effects of ALA on EMT-mediated renal interstitial fibrosis in mice with unilateral ureteral obstruction (UUO). UUO mice developed severe tubular atrophy and tubulointerstitial fibrosis, with a robust EMT response and ECM deposition after 7 postoperative days. In contrast, ALA-treated UUO mice showed only moderate injury and minimal fibrosis and also larger reductions in the expression of ECM proteins, inflammatory factors, and EMT markers. ALA was shown to be involved in the suppression of infiltrating macrophages associated with EMT and the progression of interstitial fibrosis. It also lessened the destruction of the tubular basement membrane, by reducing the expression of matrix metalloproteinases. This is the first study to show that ALA modulates EMT in a UUO mouse model. Our results suggest that ALA merits further exploration as a therapeutic agent in the prevention and treatment of chronic kidney disease.

QiShenYiQi Attenuates Renal Interstitial Fibrosis by Blocking the Activation of β-Catenin

Chronic kidney disease (CKD) is becoming a worldwide problem. However, current treatment options are limited. In the current study we showed that QiShenYiQi (QSYQ), a water-ethanol extract from several Chinese medicines, is a potent inhibitor of renal interstitial fibrosis. QSYQ inhibited transforming growth factor-β1 (TGF-β1)-responsive α-smooth muscle actin (α-SMA), collagen I, and fibronectin up-regulation in obstructive nephropathy and cultured cells. Administration of QSYQ also inhibited the established renal interstitial fibrosis in obstructive nephropathy. Interestingly, QSYQ selectively inhibited TGF-β1-induced β-catenin up-regulation and downstream gene transcription. Taken together, our study suggests that QSYQ selectively inhibits TGF-β1-induced β-catenin up-regulation and might have significant therapeutic potential for the treatment of renal fibrosis.

Epigallocatechin-3-gallate attenuates cadmium-induced chronic renal injury and fibrosis

Cadmium (Cd) pollution is a serious environmental problem. Kidney is a main target organ of Cd toxicity. This study was undertaken to investigate the potential protective effects of epigallocatechin-3-gallate (EGCG) against chronic renal injury and fibrosis induced by CdCl2. Rat model was induced by exposing to 250 mg/L CdCl2 through drinking water. The renal function was evaluated by detecting the levels of blood urea nitrogen (BUN) and serum creatinine (SCR). The oxidative stress was measured by detecting the levels of malondialdehyde (MDA), nitric oxide (NO), reduced glutathione/oxidized glutathione (GSH/GSSG) and renal enzymatic antioxidant status. Additionally, the renal levels of transforming growth factor-β1 (TGF-β1), Smad3, phosphorylation-Smad3 (pp-Smad3), α-smooth muscle actin (α-SMA), vimentin and E-cadherin were measured by western blot assay. Renal levels of microRNA-21 (miR-21), miR-29a/b/c and miR-192 were measured by quantitative RT-PCR. It was found that EGCG ameliorated the CdCl2-induced renal injury, inhibited the level of oxidative stress, normalized renal enzymatic antioxidant status and E-cadherin level, as well as attenuated the over generation of TGF-β1, pp-Smad3, vimentin and α-SMA. EGCG also decreased the production of miR-21 and miR-192, and enhanced the levels of miR-29a/b/c. These results showed that EGCG could attenuate Cd induced chronic renal injury.

Effect of Quyu Chencuo Formula () on Renal Fibrosis in Obstructive Nephropathy Rats

OBJECTIVE

To observe the effect of Quyu Chencuo Formula (, QCF) on renal fibrosis in rats with obstructive nephropathy.

METHODS

Twenty-four rats were randomly divided into three groups, 4 for sham operation as the control group, 10 for unilateral ureteral obstruction (UUO) model group, and the rest 10 for QCF treating UUO model group. All rats were sacrificed under 3% pentobarbital (50 mg/kg) anesthesia on the 14th day after surgery, then the right kidney samples of rats were harvested for hematoxylin eosin (HE) staining and Masson staining to observe the renal pathological changes. Immunohistochemistry and Western blotting were used to examine the expression of transforming growth factor β1 (TGF-β1), and real-time polymerase chain reaction (RT-PCR) was employed to examine the expressions of TGF-β1, α-smooth muscle actin (α-SMA) and E-cadherin mRNA.

RESULTS

HE and Masson staining showed that the renal interstitial of the rats in the control group had no significant fibrotic lesion; in the model group, there were obvious interstitial fibrosis; for the QCF group, there were epithelial cell necrosis, infiltration of lymphocytes and mononuclear cells, aggravated interstitial fibrosis in varied degrees, but the pathological changes were less in the QCF group than in the model group. The immunohistochemistry and Western blotting results showed that the TGF-β1 expression was increased significantly in the model group, while decreased significantly in the QCF group (P<0.05); RT-PCR showed that the mRNA expression of α-SMA and TGF-β1 increased significantly in the model group, while both were significantly decreased in the QCF group compared with the model group (P<0.05). The mRNA expression of E-cadherin was decreased significantly in the model group, and it was significantly increased in the QCF group as compared with the model group (P<0.05).

CONCLUSION

QCF may improve renal fibrosis by regulating the expressions of TGF-β1, α-SMA and E-cadherin, and prevent the progress of kidney fibrosis.

ShenKang injection suppresses kidney fibrosis and oxidative stress via transforming growth factor-β/Smad3 signalling pathway in vivo and in vitro

Objectives

The purpose of this study is to investigate the antifibrosis and antioxidation of ShenKang injection (SKI) in vivo and in vitro and to evaluate potential mechanisms involved in the treatment of chronic kidney disease (CKD).

Methods

In experimental animal studies, CKD was established by 5/6 nephrectomy (5/6Nx). Serum creatinine (Scr) and blood urea nitrogen (BUN) were determined. Histopathological tests were performed by H&E and Masson trichrome stained. The protein expressions of fibronectin (FN), collagen Ι, α-smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β) and phosphorylation of Smad3 were measured in 5/6Nx rats. In Human kidney proximal tubular cell line (HK-2) cells, the effects of TGF-β/Smad3 signalling pathway on renal fibrosis and oxidative injury were examined.

Key findings

5/6Nx induced severe renal damages. Treatment of rats with SKI markedly reduced levels of Scr and BUN, alleviated expression of fibrosis-associated signalling molecules and reduced expression of TGF-β and phosphorylated Smad3. Meanwhile, in HK-2 cells, after exposure to TGF-β and H2O2, the protein expression of renal fibrosis was significantly increased. The generation of oxidative stress was also elevated. The severity of fibrosis and oxidative damage appears to be reduced after treatment with SKI.

Conclusion

SKI inhibits renal fibrosis and oxidative stress through downregulation of TGF-β/Smad3 signalling pathway.

Ulinastatin attenuates renal interstitial inflammation and inhibits fibrosis progression in rats under unilateral ureteral obstruction

The aim of the present study was to examine the protective effects of the urinary trypsin inhibitor ulinastatin (UTI) on renal interstitial inflammation and fibrosis in rats subjected to unilateral ureteral obstruction (UUO). A total of 24 male Wistar rats were randomly divided into the three groups; the sham operation (SOR) group (n=8), the UUO group (n=8) and the UUO+UTI group (post‑UUO UTI treatment, n=8). UUO was performed with complete ligation of the left ureter. As a medical intervention, saline (4 ml kg‑1 d‑1) and UTI (40000 units kg‑1 d‑1) were injected, respectively, into the animals of the corresponding groups on day one following surgery. The rats in all three groups were euthanized on day seven post surgery. Blood samples were harvested for blood urea nitrogen (BUN) and serum creatinine (Scr) content measurements. The degree of interstitial pathological changes in the tissues from the obstructed kidneys were observed through hematoxylin and eosin (H&E) and Masson staining. The CD68+ macrophage amount, tumor necrosis factor‑α (TNF‑α), interleukin 1β (IL‑1β), nuclear factor‑κB (NF‑κB), transforming growth factor‑β1 (TGF‑β1) and type I collagen (Col‑I) levels were examined immunohistochemically. The protein expression levels of NF‑κB were examined using western blot analysis. Total superoxide dismutase (SOD) activity and malondialdehyde (MDA) content of homogenates were measured spectrophotometrically. The results revealed that ulinastatin had no statistically significant effect on the BUN and Scr levels (P>0.05). However, in comparison with the SOR group, the UUO group exhibited significantly more severe renal interstitial pathological injury in terms of tubular dilation, epithelial atrophy, renal interstitial inflammatory cell infiltration and proliferation of fibrous tissues, as well as significantly elevated levels of interstitial CD68+ macrophages, IL‑1β, TNF‑α, NF‑κB, TGF‑β1 and Col‑I (P<0.01). UTI treatment significantly reduced UUO‑induced renal interstitial damage with reduced levels of interstitial CD68+ macrophages, IL‑1β, TNF‑α, NF‑κB, TGF‑β1 and Col‑I and MDA (P<0.05), and increased SOD levels (P<0.05). In conclusion, the present study indicated that UTI is able to effectively inhibit UUO‑side renal interstitial inflammatory reaction and fibrosis in UUO‑inflicted rats.

Dipeptidyl peptidase IV inhibitor protects against renal interstitial fibrosis in a mouse model of ureteral obstruction

Dipeptidyl peptidase IV (DPPIV) is an exopeptidase that modulates the function of several substrates, among which insulin-releasing incretin hormones are the most well known. DPPIV also modulate substrates involved in inflammation, cell migration, and cell differentiation. Although DPPIV is highly expressed in proximal renal tubular cells, the role of DPPIV inhibition in renal disease is not fully understood. For this reason, we investigated the effects of LC15-0444, a DPPIV inhibitor, on renal function in a mouse model of renal fibrosis. Eight-week-old C57/BL6 mice were subjected to unilateral ureteral obstruction (UUO) and were treated with LC15-0444 (a DPPIV inhibitor) at a dose of 150 mg/kg per day in food or vehicle for 14 days. DPPIV activity was significantly increased in obstructed kidneys, and reduced after treatment with LC15-0444. Administration of LC15-0444 resulted in a significant decrease in albuminuria, urinary excretion of 8-isoprostane, and renal fibrosis. DPPIV inhibition also substantially decreased the synthesis of several proinflammatory and profibrotic molecules, as well as the infiltration of macrophages. UUO significantly increased, and LC15-0444 markedly suppressed, levels of phosphorylated Smad2/3, TGFβ1, toll-like receptor 4, high-mobility group box-1, NADPH oxidase 4, and NF-κB. These results suggest that activation of DPPIV in the kidney has a role in the progression of renal disease and that targeted therapy inhibiting DPPIV may prove to be a useful new approach in the management of progressive renal disease, independent of mechanisms mediated by glucagon-like peptide-1.

Oleanolic acid attenuates renal fibrosis in mice with unilateral ureteral obstruction via facilitating nuclear translocation of Nrf2

Background

Renal interstitial fibrosis is a common final pathological process in the progression of kidney disease. This is primarily due to oxidative stress, which contributes to renal inflammation and fibrosis. Nuclear factor-erythroid-2-related factor 2 (Nrf2) is known to coordinate induction of genes that encode antioxidant enzymes. We investigated the effects of oleanolic acid, a known Nrf2 activator, on oxidative stress-induced renal inflammation and fibrosis.

Methods

One day before unilateral ureteral obstruction (UUO) performed in C57BL/6 mice, oleanolic acid treatment was initiated and was continued until 3 and 7 days after UUO. Renal inflammation and fibrosis, markers of oxidative stress, and changes in Nrf2 expression were subsequently evaluated.

Results

In the obstructed kidneys of UUO mice, oleanolic acid significantly attenuated UUO-induced collagen deposition and fibrosis on day 7. Additionally, significantly less inflammatory cell infiltration, a lower ratio of Bax to Bcl-2 expression, and fewer apoptotic cells on TUNEL staining were observed in the obstructed kidneys of oleanolic acid-treated mice. Oleanolic acid increased the expression of nuclear Nrf2, heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 and heat shock protein 70, and decreased lipid peroxidation in the obstructed kidney of UUO mice. There were no changes in the expression of total Nrf2 and Kelch-like ECH-associated protein 1, indicating that oleanolic acid enhanced nuclear translocation of Nrf2.

Conclusions

These results suggest that oleanolic acid may exert beneficial effects on renal fibrosis by increasing nuclear translocation of Nrf2 and subsequently reducing renal oxidative stress.

Hydrogen-rich saline ameliorates renal injury induced by unilateral ureteral obstruction in rats

Hydrogen has been demonstrated to have effective protection against tissue injuries caused by oxidative stress, inflammation, and apoptosis. This study investigated the efficacy of hydrogen-rich saline (HS) on the prevention of renal injury induced by unilateral ureteric obstruction (UUO) in rats. Male Sprague-Dawley rats were divided randomly into 4 groups: sham group, UUO group, UUO+saline group, and UUO+HS group. UUO was induced by ligation of the left ureter. 5ml/kg HRSS or saline was administered beginning 1day after UUO and for 10days thereafter. Rats were killed at 10days after UUO. Left kidneys were excised immediately for the tissue histologic examinations and biochemical assays. Renal injury scores in the UUO group and the UUO+saline group were significantly higher compared with those in the sham group. However, administration of HS significantly reduced the injury score. Apoptosis index was significantly increased in UUO group and the UUO+saline group. HS treatment also reduced the apoptosis index. Interstitial fibrosis and macrophage infiltration were obvious in UUO kidneys. However, HS treatment significantly reduced the fibrosis and infiltration of macrophage in UUO kidneys. Significant increase in the MDA level and decrease in the SOD activity were observed in UUO group and the UUO+saline group. MDA level of UUO+HS group was significantly reduced. In addition, SOD activity of was significantly improved after treatment of HS. The data provide a biochemical and histologic basis for HS acting as a novel therapeutic strategy for preventing the renal injury induced by UUO.