Renal Inflammatory Cell Infiltration Research Articles

Anti-Inflammatory, Antioxidant, and Antifibrotic Effects of Kefir Peptides on Salt-Induced Renal Vascular Damage and Dysfunction in Aged Stroke-Prone Spontaneously Hypertensive Rats.

The increased prevalence of renal dysfunction and chronic kidney disease (CKD) and the high costs and poor outcomes of treatment are a significant health issue. The consequence of chronic high blood pressure is the increased prevalence of target organ end-stage renal disease, which has been proven to be a strong independent risk factor for adverse cardiovascular disease. A previous study showed that kefir products have anti-inflammatory and anti-hypertensive activities and immunological modulation functions. However, no data regarding the beneficial effects of kefir peptides (KPs) on salt-induced renal damage or related kidney diseases are available. In this study, KPs were orally administered to aged salt-induced stroke-prone spontaneously hypertensive (SHRSP) rats, and the effects of KPs against inflammation and oxidative stress and their ability to protect against renal dysfunction were evaluated. Fifty-five-week-old SHRSP rats under induction with 1% NaCl in drinking water for 4 weeks showed multiple renal injuries with increased renal inflammation, fibrosis, oxidative stress, tubular atrophy, and glomerulosclerosis. In contrast, oral gavage with KPs reduced the urine protein to creatinine (UPC) ratio, the fractional excretion of electrolytes (FeNa and FeCl), extracellular matrix deposition, and the interstitial fibrotic α-smooth muscle actin (α-SMA) levels in salt-induced SHRSP rats. The renal infiltration of inflammatory cells; the release of monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), endothelin-1 (ET-1), and the cytokine nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) and transforming growth factor-β (TGF-β); the reactive oxygen species (ROS) levels; and histopathological lesions were also decreased in salt-induced SHRSP rats. Furthermore, KP treatment significantly increased the renal superoxide dismutase (SOD) activity and the glomerular filtration rate (GFR), which exerted potent protection against salt-induced chronic kidney disease in SHRSP rats. The results of this study suggest that KPs ameliorate salt-induced renal damage, tubular atrophy, and glomerular dysfunction through anti-inflammatory, antioxidative stress, and antifibrotic activities, and might be a promising protective agent against high salt-induced renovascular-related diseases.

Zinc Deficiency Aggravation of ROS and Inflammatory Injury Leading to Renal Fibrosis in Mice.

Zinc (Zn) is a trace element with a variety of anti-inflammatory and antioxidant effects. Zn deficiency is related to tissue fibrosis. The present study was designed to investigate the effect of Zn on renal fibrosis. Mouse models were successfully established by feeding mice diets with different concentrations of Zn. Zn deficiency induced a decrease in Zn levels in kidney tissue. The results also revealed renal vasodilation, hyperemia, and inflammatory cell infiltration, and the levels of creatinine and urea nitrogen were increased. Furthermore, the TUNEL results showed a large degree of renal cell necrosis caused by Zn deficiency. Meanwhile, the corresponding antioxidant and anti-inflammatory regulators (MT-1, MT-2, Nrf2, and TGF-β1) were detected by RT-PCR, showing that the expression of MT-1, MT-2, and Nrf2 decreased but that TGF-β1 expression increased. The results of Sirius red staining proved that the expression of collagen was increased by Zn deficiency. The immunohistochemical experiments found that the expression of α-smooth muscle actin (α-SMA) increased. ELISA showed that the expression of Collagen I, III, and IV; fibronectin (FN); and inflammatory factors (TNF-α and IL-1β) were remarkably increased. The expression of MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-12, and TIMP-1, which are extracellular matrix-regulating molecules, was detected by RT-PCR. The results showed that the expression of TIMPs was increased but that the expression of MMPs was decreased. We also obtained consistent results in vivo. All the experimental results indicated that Zn deficiency could aggravate fibrosis by increasing inflammation in the kidney.

Evaluation of urine N-acetyl-β-D-glucosaminidase in renal tubular interstitial lesions of IgA nephropathy

Objective To explore the clinical significance of urine NAG in judging the condition of renal tubular interstitial lesions in patients with IgA nephropathy (IgAN). Methods The data of 82 IgAN patients who had been clinical and pathological diagnosed in our hospital from February 2014 to June 2018 were collected. According to NAG normal level, all patients were divided into NAG normal group and high NAG group. The difference of clinic index and pathological scores between two groups were compared, and the clinical and pathological risk factor which have correlation with urine NAG were assessed. Results There had significant differences in Cr, micro-albumin(mALB), Cys-C, and NAG between two groups(P<0.05). The pathological lesion scores of mesangial cell proliferation, interstitial inflammatory cell infiltration, renal interstitial fibrosis, and tubular atrophy comparison between groups were compared. There were statistically significant differences(P<0.05). The correlation analysis showed that there were positive correlations of NAG with mALB, eGFR , renal interstitial inflammatory cell infiltration, renal tubular atrophy, renal fibrosis and the mesangial cell proliferation. Conclusions Urinary NAG levels are closely related to renal function, proteinuria and tubule-interstitial lesions, which can be used as clinical indicators to evaluate and monitor the degree of tubule-interstitial lesions in IgAN. Key words: Glomerulonephritis, IGA; Uridine Diphosphate N-Acetylglucosamine; Nephritis, Interstitial

Phloretin ameliorates hyperuricemia-induced chronic renal dysfunction through inhibiting NLRP3 inflammasome and uric acid reabsorption

BackgroundHyperuricemia (HUA) is an important risk factor for renal diseases and contributes to renal fibrosis. It has been proved that phloretin has antioxidant and anti-inflammatory properties and could inhibit uric acid (UA) uptake in vitro. However, whether phloretin has a renal protective role in vivo remains unknown. PurposeThis study aims to evaluate the therapeutic effect of phloretin on HUA-induced renal injury in mice and to reveal its underlying mechanism. MethodsMice were induced hyperuricemic by oral gavage of adenine/potassium oxonate. The effects of phloretin on renal function, fibrosis, oxidative stress, inflammation, and UA metabolism in HUA mice were evaluated. The effect of phloretin on NLRP3 pathway was analyzed in human renal tubular cell lines (HK-2). ResultsHUA mice showed renal dysfunction with increased renal fibrosis, inflammation and mitochondrial stress. By contrast, phloretin reduced the level of serum blood urea nitrogen (BUN), urinary albumin to creatinine ratio (UACR), tubular necrosis, extracellular matrix (ECM) deposition and interstitial fibroblasts in HUA mice. The renal infiltration of inflammatory cells, cytokines such as NOD-like receptor family pyrin domain containing 3 (NLRP3) and interleukin-1β (IL-1β) release, mitochondrial reactive oxygen species (ROS) and morphological lesions in HUA mice also decreased. Furthermore, phloretin partly inhibited renal glucose transporter 9 (GLUT9) and promoted urinary UA excretion in HUA mice. In vitro, phloretin suppressed the NLPR3 pathway under LPS or UA stimulation in HK-2 cells. ConclusionsPhloretin could effectively attenuate UA-induced renal injury via co-inhibiting NLRP3 and UA reabsorption, and thus it might be a potential therapy to hyperuricemia-related renal diseases.

Functional regulation of von Willebrand factor ameliorates acute ischemia-reperfusion kidney injury in mice

Acute kidney injury (AKI), an abrupt loss of renal function, is often seen in clinical settings and may become fatal. In addition to its hemostatic functions, von Willebrand factor (VWF) is known to play a role in cross-talk between inflammation and thrombosis. We hypothesized that VWF may be involved in the pathophysiology of AKI, major causes of which include insufficient renal circulation or inflammatory cell infiltration in the kidney. To test this hypothesis, we studied the role of VWF in AKI using a mouse model of acute ischemia-reperfusion (I/R) kidney injury. We analyzed renal function and blood flow in VWF-gene deleted (knock-out; KO) mice. The functional regulation of VWF by ADAMTS13 or a function-blocking anti-VWF antibody was also evaluated in this pathological condition. Greater renal blood flow and lower serum creatinine were observed after reperfusion in VWF-KO mice compared with wild-type (WT) mice. Histological analysis also revealed a significantly lower degree of tubular damage and neutrophil infiltration in kidney tissues of VWF-KO mice. Both human recombinant ADAMTS13 and a function-blocking anti-VWF antibody significantly improved renal blood flow, renal function and histological findings in WT mice. Our results indicate that VWF plays a role in the pathogenesis of AKI. Proper functional regulation of VWF may improve the microcirculation and vessel function in the kidney, suggesting a novel therapeutic option against AKI.

Aldosterone promotes renal interstitial fibrosis via the AIF‑1/AKT/mTOR signaling pathway.

A number of studies have shown that aldosterone serves an important role in promoting renal interstitial fibrosis, although the specific mechanism remains to be elucidated. A previous study revealed that the fibrotic effect of aldosterone was associated with the expression of allograft inflammatory factor 1 (AIF-1) in RAW264.7 macrophage cells, in a time- and concentration-dependent manner. However, the exact mechanism through which aldosterone promotes renal interstitial fibrosis remains unknown. In the present study, the effects of aldosterone on renal inflammatory cell infiltration, collagen deposition and the expression levels of AIF-1, phosphatidylinositol 3-kinase (PI3K), AKT serine/threonine kinase (AKT), mammalian target of rapamycin (mTOR), the oxidative stress factor NADPH oxidase 2 (NOX2) and nuclear transcription factor erythroid-related factor 2 (Nrf2) were assessed in normal rats, rats treated with aldosterone, rats treated with aldosterone and spironolactone and those treated with spironolactone only (used as the control). The effect of aldosterone on these factors was also investigated in the renal interstitium of unilateral ureteral obstruction (UUO) rats. Additionally, the AIF-1 gene was overexpressed and knocked down in macrophage RAW264.7 cells, and the effects of aldosterone on PI3K, AKT, mTOR, NOX2 and Nrf2 were subsequently investigated. The results showed that aldosterone promoted inflammatory cell infiltration, collagen deposition and the expression of AIF-1, PI3K, AKT, mTOR and NOX2, but inhibited the expression of Nrf2. In the UUO rats, aldosterone also promoted renal interstitial inflammatory cell infiltration, collagen deposition and the expression of AIF-1, NOX2, PI3K, AKT and mTOR, whereas the expression of Nrf2 was downregulated by aldosterone compared with that in the UUO-only group; the influence of aldosterone was counteracted by spironolactone in the normal and UUO rats. In vitro, aldosterone upregulated the expression levels of AKT, mTOR, NOX2 and Nrf2 in RAW264.7 cells compared with those in untreated cells. Suppressing the expression of AIF-1 inhibited the effects of aldosterone, whereas the overexpression of AIF-1 enhanced these effects in RAW264.7 cells. These findings indicated that aldosterone promoted renal interstitial fibrosis by upregulating the expression of AIF-1 and that the specific mechanism may involve AKT/mTOR and oxidative stress signaling.

Blocking pannexin-1 alleviates cisplatin-induced acute kidney injury in mice by reducing renal inflammatory cell infiltration

To investigate the effect of blocking pannexin-1 against acute kidney injury induced by cisplatin. Twenty-six male C57BL/6 mice aged 6-8 weeks were randomly divided into control group, cisplatin model (Cis) group and cisplatin + carbenoxolone treatment group (Cis + CBX). In Cis group and Cis + CBX group, the mice were injected intraperitoneally with 20 mg/kg of cisplatin and with CBX (20 mg/kg) at 30 min before and 24 and 48 h after cisplatin inhjection, respectively. All the mice were sacrificed at 72 h after cisplatin injection, and plasma and kidney samples were collected for testing mRNA and protein expression levels of pannexin-1 in the renal tissue using RT-qPCR and Western blotting and for detecting plasma creatinine and BUN levels; the pathological changes in the renal tissues were observed using Periodic Acid-Schiff staining. The expression of kidney injury molecule 1 (KIM-1) was examined using immunohistochemistry and the mRNA expressions of KIM-1 and neutrophil gelatinase- related lipid transport protein (NGAL) were detected by RT-qPCR to evaluate the injuries of the renal tubules. The infiltration of F4/80-positive macrophages and CD4-positive T cells were observed by immunofluorescence. In the in vitro experiment, human proximal tubule epithelial cell line HK-2 was stimulated with 50 μmol/L cisplatin to establish a cell model of acute kidney injury, and the mRNA and protein expressions of pannexin-1 were detected by RT-qPCR and Western blotting at 4, 6, 12, 18 and 24 h after the stimulation. Compared with the control mice, the cisplatin-treated mice showed significantly up-regulated protein levels (P &lt; 0.05) and mRNA levels (P &lt; 0.005) of pannexin-1 in the kidney tissue. Cisplatin stimulation also caused significant increases in the protein levels (P &lt; 0.005) and mRNA levels (P &lt; 0.005) of pannexin-1 in cultured HK-2 cells. Compared with cisplatin-treated mice, the mice treated with both cisplatin and the pannexin-1 inhibitor CBX showed obviously lessened kidney pathologies and milder renal tubular injuries with significantly reduced plasma BUN and Scr levels (P &lt; 0.01), expressions of KIM-1 and NGAL in the kidney (P &lt; 0.05), and infiltration of F4/80-positive macrophages (P &lt; 0.01) and CD4- positive T cells (P &lt; 0.05) in the kidney tissues. In cisplatin induced acute kidney injury mice model, Pannexin-1 expression is up-regulated in the kidneys tissue, and blocking pannexin-1 alleviates the acute kidney injury via reducing renal inflammatory cell infiltration.

Renal Fibrosis, Immune Cell Infiltration and Changes of TRPC Channel Expression after Unilateral Ureteral Obstruction in Trpc6-/- Mice

The transient receptor potential cation channel subfamily C member 6 (TRPC6) is a Ca2+-permeable nonselective cation channel and has received recent attention because of its capability to promote chronic kidney disease (CKD). The aims of this study were (i) to examine whether deletion of TRPC6 impacts on renal fibrosis and inflammatory cell infiltration in an early CKD model of unilateral ureter obstruction (UUO) in mice; and (ii) whether TRPC6-deficiency as well as UUO affect the regulation of TRPC expression in murine kidneys. Wild-type (WT), Trpc6-knockout (Trpc6-/-) and New Zealand obese (NZO) mice underwent sham operation or unilateral ureteral obstruction (UUO). The kidneys were harvested 7 days after surgery. We examined renal fibrosis and inflammatory cell infiltration by histological and immunohistochemical staining. The mRNA expression of TRPC members and markers of fibrosis and inflammation in kidney were assessed by using real-time quantitative reverse transcription PCR. Histological and immunohistochemical analyses revealed less inflammatory cell infiltration (F4/80 and CD3) in UUO kidneys of Trpc6-/- mice compared to UUO kidneys of WT mice as well as less fibrosis. Genomic deletion of TRPC6 also affected the expression of pro-fibrotic genes in UUO Trpc6-/- kidneys compared to UUO WT kidneys while the expression of pro-inflammatory genes did not differ. UUO caused marked up-regulation of Trpc6 and down-regulation of Trpc1 mRNA in kidneys of WT and NZO mice. Trpc3 mRNA expression was significantly elevated in kidneys of Trpc6-/- mice underwent UUO while the levels did not change in kidneys of neither WT nor in NZO mice underwent UUO. TRPC6 contributes to renal fibrosis and immune cell infiltration in the UUO mouse model. Therefore, inhibition of TRPC6 emerges as a promising novel therapeutic strategy for treatment of chronic kidney failure in chronic obstructive nephropathy. However, confounding genomic and non-genomic effects of other TRPC channels should be taken into consideration to fully comprehend the renoprotective potential of targeting TRPC6 therapeutically under chronic kidney damaging conditions.

Interleukin-17A blockade reduces albuminuria and kidney injury in an accelerated model of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common complications of diabetes, and currently the first end-stage renal disease worldwide. New strategies to treat DN using agents that target inflammatory pathways have attracted special interest. Recent pieces of evidences suggest a promising effect of IL-17A, the Th17 effector cytokine. Among experimental DN models, mouse strain BTBR ob/ob (leptin deficiency mutation) develops histological features similar to human DN, which means an opportunity to study mechanisms and novel therapies aimed at DN regression. We found that BTBR ob/ob mice presented renal activation of the factors controlling Th17 differentiation. The presence of IL-17A-expressing cells, mainly CD4+ and γδ lymphocytes, was associated with upregulation of proinflammatory factors, macrophage infiltration and the beginning of renal damage. To study IL-17A involvement in experimental DN pathogenesis, treatment with an IL-17A neutralizing antibody was carried out starting when the renal damage had already appeared. IL-17A blockade ameliorated renal dysfunction and disease progression in BTBR ob/ob mice. These beneficial effects correlated to podocyte number restoration and inhibition of NF-κB/proinflammatory factors linked to a decrease in renal inflammatory-cell infiltration. These data demonstrate that IL-17A takes part in diabetes-mediated renal damage and could be a promising therapeutic target to improve DN.

High renal DC-SIGN+ cell density is associated with severe renal lesions and poor prognosis in patients with immunoglobulin A nephropathy.

In this observational cohort study, we assessed the prognostic value of DC-SIGN+ cells in the pathogenesis and progression of IgA nephropathy (IgAN). A total of 139 adult IgAN patients were enrolled into this study from June 2009 to June 2010. We characterised DC-SIGN+ cells by immunohistochemistry or immunofluorescence in renal biopsy tissue. Correlations between the DC-SIGN, intercellular adhesion molecule 3 (ICAM-3), CD4 and CD8 were evaluated. Patients were classified into the DC-SIGNhigh and DC-SIGNlow groups. Depending on an average of 100-month follow-up, the predictive value of DC-SIGN+ cells in IgAN progression was analysed. DC-SIGN+ cells were found frequently in IgAN kidneys while rarely observed in normal kidneys, and almost all DC-SIGN+ cells expressed MHC-II. We also found that DC-SIGN+ cells were adjacent to ICAM-3-positive CD4+ and CD8+ lymphocytes. The density of DC-SIGN+ cells was positively and linearly correlated with the density of ICAM-3+ cells, CD4+ cells and CD8+ cells in renal biopsy tissues. In the DC-SIGNhigh group, the degree of renal lesion and inflammatory cell infiltration was more severe compared to the DC-SIGNlow group. Patients in the DC-SIGNhigh group also had increased incidences of deteriorating renal function during the follow up compared to patients in the DC-SIGNlow group. DC-SIGN+ cells probably served as a potential contributor to exacerbate local inflammatory response. The density of DC-SIGN+ cells was associated with the severity of renal lesions of the patients. High renal DC-SIGN+ cell density might be used as a predictor of poor prognosis in patients with IgAN.

La néphrite de Lyme chez l’homme : bases physiopathologiques et spectre lésionnel rénal

Known in less than half a century, borreliosis, or Lyme disease, is a zoonosis caused by the tick bite. It is the most common vector disease in Europe and the United States. Borrelia burgdorferi sensu lato, the bacterium in question, is fitted with a “cunning device” that allows it to trick the immune system and implant the infection chronically. It causes multi-system tissue damage mediated by the inflammatory response of the host. Renal involvement is rarely reported and is better known in dogs as Lyme nephritis. The first case of kidney impairment in the human being was described in 1999, and since then eight other cases have been reported. The involvement is preferentially glomerular; the histological forms vary between immune complex nephropathy and podocytopathy. The pathophysiological mechanisms appear to be triple: immune complex deposits, podocytic hyper-expression of the B7-1 membrane protein, and renal infiltration of inflammatory cells. On the basis of the accumulated knowledge of the disease in just over 40 years, this review aims at establishing the physio-pathological hypotheses of renal involvement in order to better define the histological lesions.

Gremlin activates the Notch pathway linked to renal inflammation.

Preclinical studies suggest that Gremlin participates in renal damage and could be a potential therapeutic target for human chronic kidney diseases. Inflammation is a common characteristic of progressive renal disease, and therefore novel anti-inflammatory therapeutic targets should be investigated. The Notch signaling pathway is involved in kidney development and is activated in human chronic kidney disease, but whether Gremlin regulates the Notch pathway has not been investigated. In cultured tubular cells, Gremlin up-regulated gene expression of several Notch pathway components, increased the production of the canonical ligand Jagged-1, and caused the nuclear translocation of active Notch-1 (N1ICD). In vivo administration of Gremlin into murine kidneys elicited Jagged-1 production, increased N1ICD nuclear levels, and up-regulated the gene expression of the Notch effectors hes-1 and hey-1 All these data clearly demonstrate that Gremlin activates the Notch pathway in the kidney. Notch inhibition using the γ-secretase inhibitor DAPT impaired renal inflammatory cell infiltration and proinflammatory cytokines overexpression in Gremlin-injected mice and in experimental models of renal injury. Moreover, Notch inhibition blocked Gremlin-induced activation of the canonical and noncanonical nuclear factor-κB (NF-κB) pathway, identifying an important mechanism involved in the anti-inflammatory actions of Notch inhibition. In conclusion, Gremlin activates the Notch pathway in the kidney and this is linked to NF-κB-mediated inflammation, supporting the hypothesis that Notch inhibition could be a potential anti-inflammatory strategy for renal diseases.

Exosomal CCL2 from Tubular Epithelial Cells Is Critical for Albumin-Induced Tubulointerstitial Inflammation.

Albuminuria is a key instigator of tubulointerstitial inflammation associated with CKD, but the mechanism through which filtered albumin propagates renal injury remains unclear. In this study, we explored the role in this process of exosome mRNA released from tubular epithelial cells (TECs). Compared with control mice, acute and chronic kidney injury models had more exosomes containing inflammatory cytokine mRNA, particularly the chemokine CCL2, in kidneys and urine. In vitro stimulation of TECs with BSA recapitulated this finding. Notably, the internalization of purified TEC exosomes by cultured macrophages increased if TECs were exposed to BSA. Macrophage internalization of exosomes from BSA-treated TECs led to an enhanced inflammatory response and macrophage migration, but CCL2 silencing in TECs prevented these effects. Using a GFP-CCL2 fusion mRNA construct, we observed direct transfer of CCL2 mRNA from TEC exosomes to macrophages. Mice subjected to tail vein injection of purified BSA-treated TEC exosomes developed tubular injury with renal inflammatory cell infiltration. However, injection of exosomes from BSA-treated CCL2-deficient TECs induced less severe kidney inflammation. Finally, in patients with IgA nephropathy, the increase of proteinuria correlated with augmented urinary excretion of exosomes with exaggerated expression of CCL2 mRNA. Moreover, the level of CCL2 mRNA in urinary exosomes correlated closely with levels of renal interstitial macrophage infiltration in these patients. Our studies demonstrate that the increasing release of exosomes that transfer CCL2 mRNA from TECs to macrophages constitutes a critical mechanism of albumin-induced tubulointerstitial inflammation.

Carnosol protects against renal ischemia-reperfusion injury in rats.

Acute kidney injury, which is caused by renal ischemia-reperfusion injury (IRI), occurs in several clinical situations and causes severe renal damage. There is no effective therapeutic agent available for renal IRI at present. In this study, we performed an experiment based on an in vivo murine model of renal IRI to examine the effect of carnosol. Thirty Sprague-Dawley rats were randomized into three groups (10 rats in each group): the sham, IRI, and carnosol groups. Rats in the carnosol group were injected intravenously with 3 mg/kg of carnosol, and those in the sham and IRI groups were injected intravenously with 10% dimethyl sulfoxide 1 h before ischemia. Rats were sacrificed after 24 h of reperfusion. The blood and kidneys were harvested, renal function was assessed, and histologic evaluation was performed to analyze renal injury. A renal myeloperoxidase activity assay, in-situ apoptosis examination, enzyme-linked immunosorbent assay, immunohistochemical assay, and western blot were also performed. Carnosol pretreatment significantly reduced renal dysfunction and histologic damage induced by renal IRI. Carnosol pretreatment suppressed renal inflammatory cell infiltration and pro-inflammatory cytokine expression. In addition, carnosol markedly inhibited apoptotic tubular cell death, caspase-3 activation, and activation of the p38 pathway. Carnosol pretreatment protects rats against renal IRI by inhibiting inflammation and apoptosis. Although future investigation is needed, carnosol may be a potential therapeutic agent for preventing renal IRI.

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.

Mast Cell and M1 Macrophage Infiltration and Local Pro-Inflammatory Factors Were Attenuated with Incretin-Based Therapies in Obesity-Related Glomerulopathy

Background: The global increase of obesity parallels the obesity-related glomerulopathy (ORG) epidemic. Dipeptidyl peptidase 4 inhibitors and glucagon-like peptide-1 receptor agonists were well recognized to attenuate renal injury independent of glucose control in diabetic nephropathy. There are limited studies focusing on their effects on ORG. We explored the effects of incretin-based therapies on early ORG and the inflammatory responses involved mainly concentrated on mast cell (MC) and macrophage (M) infiltration and local pro-inflammatory factors.Methods: ORG rat models were induced by high-fat diet and then divided into ORG vehicle, vildagliptin (3 mg/kg/day, qd) and liraglutide (200 μg/kg, bid) treated groups. After 8 weeks of treatments, albuminuria, glomerular histology, renal inflammatory cell infiltration, and pro-inflammatory factors were analyzed.Results: Early ORG model was demonstrated by albuminuria, glomerulomegaly, foot process fusion, and mesangial and endothelial mild proliferation. Incretin-based therapies limited body weight gain and improved insulin sensitivity. ORG was alleviated, manifested by decreased average glomerular area, attenuated mesangial and endothelial cell proliferation, and revived cell-to-cell propagation of podocytes, which contributed to reduced albuminuria. Compared with ORG vehicle, MC and M1 macrophage (pro-inflammatory) infiltration and M1/M2 ratio were significantly decreased; M2 macrophage (anti-inflammatory) was not significantly increased after incretin-based treatments. Tumor necrosis factor-α (TNF-α) and IL-6 in renal cortex were significantly downregulated, while transforming growth factor-β1 (TGF-β1) remained unchanged.Conclusions: Incretin-based treatments could alleviate high-fat diet-induced ORG partly through the systemic insulin sensitivity improvement and the attenuated local inflammation, mainly by the decrease of MC and M1 macrophage infiltration and reduction of TNF-α and IL-6.

Mapping urinary chemokines in human lupus nephritis: Potentially redundant pathways recruit CD4+ and CD8+ T cells and macrophages.

Renal infiltration of inflammatory cells contributes to the pathogenesis of lupus nephritis (LN). Current knowledge on the recruitment mechanisms relies mainly on findings in rodent models. Here, we assess various chemokine pathways in human LN by comparing urinary chemokine concentrations (in 25 patients with acute LN and in 78 lupus patients without active LN) with the expression of corresponding chemokine receptors on urinary leukocytes (in ten acute LN patients). Nine urinary chemokines were significantly elevated in LN patients and correlated with renal disease activity and urinary cell counts; however, their concentrations displayed considerable interindividual heterogeneity. Analysis of the corresponding receptors revealed abundance of urinary CD8+ T cells for CCR5 and CXCR3, while CD4+ T cells were additionally enriched for CCR1, CCR6 and CXCR6. Urinary Treg showed similar CCR expression, and urinary CD14+ macrophages were enriched for CCR5 expressing cells. In conclusion, cell specific recruitment patterns seem to involve CCR5 and CXCR3 in all cells studied, while CD4+ T-cell subset recruitment is probably much more varied. However, urinary chemokine abundance in active LN is individually variable in our cohort and does not offer a singular chemokine usable as universal biomarker or potential future treatment target.

Suppression of interleukin 17 contributes to the immunomodulatory effects of adipose-derived stem cells in a murine model of systemic lupus erythematosus.

Due to roles in immunoregulation and low immunogenicity, mesenchymal stem cells have been suggested to be potent regulators of the immune response and may represent promising treatments for autoimmune disease. Adipose-derived stem cells (ADSCs), stromal cells derived from adipose tissue, were investigated with allogeneic ADSCs in B6.MRL/lpr mice, a murine model of systemic lupus erythematosus (SLE). We intravenously injected allogeneic ADSCs into SLE mice after disease onset and report that ADSCs reduced anti-ds DNA antibodies in serum and proteinuria in SLE mice. Also, ADSCs decreased IL-17 and IL-6 expression in serum of SLE mice. ADSCs alleviated renal damage and inflammatory cell infiltration and edema of the renal interstitium. Furthermore, ADSCs significantly downregulated renal IL-17 and CD68 expression, suggesting that ADSCs suppressed renal inflammation. ADSCs also decreased IL-17 mRNA expression and increased Foxp3, ROR-γt and miR-23b mRNA expression in renal tissue in SLE mice. ADSCs reduced renal protein expression of TAB 2 and IKK-α in SLE mice. Thus, ADSCs may be a novel potential therapy for treating SLE.

Protective effect of luteolin on streptozotocin-induced diabetic renal damage in mice via the regulation of RIP140/NF-кB pathway and insulin signalling pathway

Luteolin (LUT) is one of the most common flavonoids present in various fruits and vegetables. The effects of luteolin (LUT) on streptozotocin (STZ)-induced diabetic renal damage were investigated. LUT was orally administered at 10, 20 mg/kg/day for 4 weeks to streptozotocin-induced diabetic mice. Serum levels of uric acid, creatinine, triacylglycerol, total cholesterol, low density lipoprotein and blood urea nitrogen were measured. Urinary uric acid and creatinine were assayed. Serum insulin level and oral glucose tolerance test (OGTT) were determined. Kidney pathological changes were detected. Receptor-interacting protein 140 (RIP140)/nuclear factor кB (NF-кB) pathway and insulin signalling pathway were detected. LUT restored streptozotocin-induced insulin resistance, dyslipidaemia, hyperuricemia, and renal inflammatory cell infiltration in streptozotocin-induced mice. Furthermore, LUT inhibited RIP140/NF-кB pathway and improved the insulin signalling pathway in streptozotocin-induced renal damage in mice. Thus, the beneficial effect of LUT against diabetic nephropathy (DN) is related to its regulation of RIP140/NF-кB and insulin pathway.

Relevant Role of Von Willebrand Factor in Ischemia-Reperfusion Model of Acute Kidney Injury in Mice

Acute kidney injury (AKI), an abrupt loss of renal function, is often seen in clinical settings and its mortality remains high even in the developed countries. An adhesive protein von Willebrand factor (VWF) plays a pivotal role in platelet thrombus formation and is recently understood as a key protein in a cross-talk between inflammation and thrombosis. Recent mouse model studies demonstrated that VWF-mediated thrombotic and inflammatory responses could play a role in the disease progression of myocardial infarction or brain stroke. Thus, we assumed that VWF may also be involved in the pathophysiology of AKI, the major cause of which could be an insufficient renal circulation and/or inflammatory cell infiltration in the kidney. To test this hypothesis, we studied the relevant role of VWF in AKI in mouse model of acute ischemia-reperfusion (I/R) kidney injury. All mice used were male, 8-12 weeks of age, healthy and whose right kidney was surgically removed by the standard mouse nephrectomy procedure 1 week prior to the kidney I/R experiment. The preliminary experiments confirmed that surgical removal of mouse right kidney did not affect their general conditions including renal functions. Mice were anesthetized with inhaled isoflurane and then placed in an abdominal position on a heating pad. Surgical incision was given on the left side of back and the left kidney was brought out and kept outside during the operation. Both renal artery and vein were clamped at the renal hilus by a clamping clip for 30 min ischemia. Then a clip was taken off to provoke the reperfusion of renal blood flow, which was monitored by Laser Doppler flowmetry (ALF21, Advance Co, Tokyo, Japan). The kidney was then put back in a body and skin incision was closed. The renal blood flow was measured again 30 h after reperfusion and mice were then sacrificed for blood collection. We compared 15 wild-type (WT) and 16 VWF-gene deleted (knock-out; KO) mice (from The Jackson Laboratory, Bar Harbor, ME). Excess blood loss was not observed in all mice (WT or KO) during whole surgical process. Although no difference was seen immediately after reperfusion, significantly (p < 0.05) higher renal blood flow at 30 h after reperfusion was confirmed in VWF-KO mice, as compared to WT (KO; 24.0±2.3 vs. WT; 15.1±1.46 ml/min/100g of kidney weight, and the reperfusion/base flow ratio: KO; 1.0±0.07 vs. WT; 0.6 ±0.07). Consistent with the renal blood flow data, the serum creatinine value at 30 h after reperfusion were significantly (p < 0.05) lower in VWF-KO mice than WT (KO; 2.77±0.11 vs. WT; 3.15±0.11 mg/dl). Our results suggest that VWF does play a role in the pathogenesis of AKI, in which VWF-dependent thrombotic or inflammatory responses may trigger thrombotic ischemia or endothelial damages of vascular bed in the kidney. Thus, proper functional regulation of VWF would be beneficial for better microcirculation and vessel functions in the kidney, suggesting a novel therapeutic potential against AKI. DisclosuresNo relevant conflicts of interest to declare.