Hyperoside Suppresses Renal Inflammation by Regulating Macrophage Polarization in Mice With Type 2 Diabetes Mellitus.

Accumulating evidence reveals that both inflammation and lymphocyte dysfunction play a vital role in the development of diabetic nephropathy (DN). Hyperoside (HPS) or quercetin-3-O-galactoside is an active flavonoid glycoside mainly found in the Chinese herbal medicine Tu-Si-Zi. Although HPS has a variety of pharmacological effects, including anti-oxidative and anti-apoptotic activities as well as podocyte-protective effects, its underlying anti-inflammatory mechanisms remain unclear. Herein, we investigated the therapeutic effects of HPS on murine DN and the potential mechanisms responsible for its efficacy. We used C57BLKS/6J Lepdb/db mice and a high glucose (HG)-induced bone marrow-derived macrophage (BMDM) polarization system to investigate the potentially protective effects of HPS on DN. Our results showed that HPS markedly reduced diabetes-induced albuminuria and glomerular mesangial matrix expansion, accompanied with a significant improvement of fasting blood glucose level, hyperlipidaemia and body weight. Mechanistically, pretreatment with HPS effectively regulated macrophage polarization by shifting proinflammatory M1 macrophages (F4/80+CD11b+CD86+) to anti-inflammatory M2 ones (F4/80+CD11b+CD206+) in vivo and in bone marrow-derived macrophages (BMDMs) in vitro, resulting in the inhibition of renal proinflammatory macrophage infiltration and the reduction in expression of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor (TNF-α) and inducible nitric oxide synthase (iNOS) while increasing expression of anti-inflammatory cytokine Arg-1 and CD163/CD206 surface molecules. Unexpectedly, pretreatment with HPS suppressed CD4+ T cell proliferation in a coculture model of IL-4-induced M2 macrophages and splenic CD4+ T cells while promoting their differentiation into CD4+IL-4+ Th2 and CD4+Foxp3+ Treg cells. Taken together, we demonstrate that HPS ameliorates murine DN via promoting macrophage polarization from an M1 to M2 phenotype and CD4+ T cell differentiation into Th2 and Treg populations. Our findings may be implicated for the treatment of DN in clinic.

A low toxicity synthetic cinnamaldehyde derivative ameliorates renal inflammation in mice by inhibiting NLRP3 inflammasome and its related signaling pathways.

Uncontrolled inflammation is a leading cause of various chronic diseases. Cinnamaldehyde (CA) is a major bioactive compound isolated from the essential oil of the leaves of Cinnamomum osmophloeum kaneh that exhibits anti-inflammatory activity; however, the use of CA is limited by its cytotoxicity. Here, we synthesized three CA derivatives and identified 4-hydroxycinnamaldehyde-galactosamine (HCAG) as a low toxicity anti-inflammatory compound in vitro (HCAG IC50 ≫ 1600 µM; CA IC50=40 µM) and in vivo. HCAG reduced pro-inflammatory mediator expression in LPS-activated macrophages by inhibiting MAPK and PKC-α/δ phosphorylation, decreasing ROS generation and reducing NF-κB activation. HCAG also reduced NLRP3 inflammasome-derived IL-1ß secretion by inhibiting the ATP-mediated phosphorylation of AKT and PKC-α/δ. In a mouse model of LPS-induced renal inflammation, we observed reduced albuminuria and a mild degree of glomerular proliferation, glomerular sclerosis and periglomerular inflammation in the HCAG-treated mice compared with the vehicle-treated mice. The underlying mechanisms for these renoprotective effects involved: (1) inhibited NLRP3 inflammasome activation; (2) decreased superoxide anion levels and apoptosis; and (3) suppressed activation of NF-κB and related downstream inflammatory mediators.

Protective effects of curcumin on acute gentamicin-induced nephrotoxicity in rats.

BACKGROUND: Gentamicin-induced nephrotoxicity is one of the most common causes of acute kidney injury (AKI). The phenotypic alterations that contribute to acute kidney injury include inflammatory response and oxidative stress. Curcumin has a wide range biological functions, especially as an antioxidant. This study was designed to evaluate the renoprotective effects of curcumin treatment in gentamicin-induced AKI. METHODS: Gentamicin-induced AKI was established in female Sprague-Dawley rats. Rats were treated with curcumin (100 mg/kg body mass) by intragastric administration, once daily, followed with an intraperitoneal injection of gentamicin sulfate solution at a dose of 80 mg/kg body mass for 8 consecutive days. At days 3 and 8, the rats were sacrificed, and the kidneys and blood samples were collected for further analysis. RESULTS: The animals treated with gentamicin showed marked deterioration of renal function, together with higher levels of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1) in the plasma as compared with the controls. Animals that underwent intermittent treatment with curcumin exhibited significant improvements in renal functional parameters. We also observed that treatment with curcumin significantly attenuated renal tubular damage, apoptosis, and oxidative stress. Curcumin treatment exerted anti-apoptosis and anti-oxidative effects by up-regulating Nrf2/HO-1 and Sirt1 expression. CONCLUSIONS: Our data clearly demonstrate that curcumin protects kidney from gentamicin-induced AKI via the amelioration of oxidative stress and apoptosis of renal tubular cells, thus providing hope for the amelioration of gentamicin-induced nephrotoxicity.

Colony-stimulating factors in inflammation and autoimmunity.

Although they were originally defined as haematopoietic-cell growth factors, colony-stimulating factors (CSFs) have been shown to have additional functions by acting directly on mature myeloid cells. Recent data from animal models indicate that the depletion of CSFs has therapeutic benefit in many inflammatory and/or autoimmune conditions and as a result, early-phase clinical trials targeting granulocyte/macrophage colony-stimulating factor and macrophage colony-stimulating factor have now commenced. The distinct biological features of CSFs offer opportunities for specific targeting, but with some associated risks. Here, I describe these biological features, discuss the probable specific outcomes of targeting CSFs in vivo and highlight outstanding questions that need to be addressed.

Downregulation of renal TRPM7 and increased inflammation and fibrosis in aldosterone-infused mice: effects of magnesium.

Hyperaldosteronism is associated with hypertension, cardiovascular fibrosis, and electrolyte disturbances, including hypomagnesemia. Mechanisms underlying aldosterone-mediated Mg(2+) changes are unclear, but the novel Mg(2+) transporters TRPM6 and TRPM7 may be important. We examined whether aldosterone influences renal TRPM6/7 and the TRPM7 downstream target annexin-1 and tested the hypothesis that Mg(2+) administration ameliorates aldosterone-induced cardiovascular and renal injury and prevents aldosterone-associated hypertension. C57B6 mice were studied (12 weeks, n=8 to 9/group); (1) control group (0.2% dietary Mg(2+)), (2) Mg(2+) group (0.75% dietary Mg(2+)), (3) aldosterone group (Aldo, 400 microg/kg/min and 0.9% NaCl drinking water), and (4) Aldo+Mg(2+) group. Blood pressure was unaltered by aldosterone and was similar in all groups throughout the experiment. Serum Na(+) was increased and serum K(+) and Mg(2+) decreased in the Aldo group. Aldo mice had hypomagnesuria and proteinuria, and renal, cardiac, and aortic fibrosis, which were normalized by Mg(2+) supplementation. Renal and cardiovascular expression of interleukin-6, VCAM1 and COX2 was increased in the Aldo group. Magnesium attenuated renal and cardiac interleukin-6 content and decreased renal VCAM1 and cardiac COX2 expression (P<0.05). Aldosterone decreased expression of renal TRPM7 and the downstream target annexin-1 (P<0.05) without effect on TRPM6. Whereas Mg(2+) increased mRNA expression of TRPM6 and TRPM7, it had no effect on TRPM7 and annexin-1 protein content. Our data demonstrate that aldosterone mediates blood pressure-independent renal and cardiovascular fibrosis and inflammation through Mg(2+)-sensitive pathways. We suggest that altered Mg(2+) metabolism in hyperaldosteronism may relate to TRPM7 downregulation and that Mg(2+) protects against cardiovascular and renal damaging actions of aldosterone.

Beneficial effect of neutrophil elastase inhibitor on anti-Thy1.1 nephritis in rats.

BACKGROUND: Neutrophil elastase, one of the proteinases released by neutrophils, plays an important role at the sites of inflammation and was reported to be involved in the pathogenesis of glomerulonephritis. Sivelestat is a selective neutrophil elastase inhibitor used for acute lung injury associated with systemic inflammatory response syndrome. There have been few reports on the effects of sivelestat on renal disease. METHODS: In male Wistar rats, anti-Thy1.1 nephritis was induced by the injection of anti-Thy1.1 antibody. The rats were divided into four groups: nephritic rats treated with low- (group A) and high-dose sivelestat (group B), those not treated with sivelestat (group C) and control rats (group D). Urine samples were obtained every day during the experiment. The rats were killed on day 6 in order to obtain the blood plasma and kidneys. Measurement of urine protein levels, blood biochemical values and histological examination of the kidneys were carried out. RESULTS: Increased levels of proteinuria were observed in the nephritic rats (groups A, B and C) compared with group D. The proteinuria level was significantly suppressed by sivelestat in groups A and B in a dose-dependent fashion compared with group C. The light microscopy revealed an increased glomerular cell count in group C, which was significantly suppressed in group B. In the electron microscopic study, sivelestat suppressed the fusion of epithelial foot process, especially in group B. CONCLUSION: Neutrophil elastase is suggested to be involved in the development of anti-Thy1.1 nephritis, and the neutrophil elastase inhibitor sivelestat reduces the tissue injury of anti-Thy1.1 nephritis in rats.

Targeting Notch signaling in autoimmune and lymphoproliferative disease.

Patients with autoimmune lymphoproliferative syndrome (ALPS) and systemic lupus erythematosis (SLE) have T-cell dysregulation and produce abnormal, activated T lymphocytes and an atypical peripheral T-cell population, termed double negative T cells (DNTs). T-cell functions, including DNT transition in T-cell development and T-cell activation, are critically dependent on Notch signaling. We hypothesized that inhibiting Notch signaling would be effective in ALPS and SLE by reducing the production of abnormal DNTs and by blocking aberrant T-cell activation. We tested this hypothesis using murine models of ALPS and SLE. Mice were randomized to treatment with the notch pathway inhibitor (gamma-secretase inhibitor), N-S-phenyl-glycine-t-butyl ester (DAPT), or vehicle control. Response to treatment was assessed by measurement of DNTs in blood and lymphoid tissue, by monitoring lymph node and spleen size with ultrasound, by quantifying cytokines by bead-array, by ELISA for total IgG and anti-double-stranded DNA (dsDNA) specific antibodies, and by histopathologic assessment for nephritis. We found a profound and statistically significant decrease in all disease parameters, comparing DAPT-treated mice to controls. Using a novel dosing schema, we avoided the reported toxicities of gamma-secretase inhibitors. Inhibiting the Notch signaling pathway may thus present an effective, novel, and well-tolerated treatment for autoimmune and lymphoproliferative diseases.

Lipoic acid supplementation prevents angiotensin II-induced renal injury.

BACKGROUND: Angiotensin II (Ang II)-induced renal injury is associated with perivascular inflammation, cell proliferation, and increased superoxide production in the vascular wall. We tested whether lipoic acid, an endogenous antioxidant, protects against the Ang II-induced inflammatory response and end-organ damage. METHODS: Light microscopy, immunohistochemistry, electrophoretic mobility shift assay, Northern blots, and high-pressure liquid chromatography (HPLC) were used in kidneys from double transgenic rats (dTGR) harboring human renin and angiotensinogen genes and normotensive Sprague Dawley (SD) rats. The effects of lipoic acid supplementation for three weeks were examined in dTGR and SD rats. RESULTS: Lipoic acid effectively prevented Ang II-induced glomerular and vascular damage in the kidneys and completely prevented the development of albuminuria. Ang II-induced leukocyte infiltration and cell proliferation in the kidney were attenuated. The redox-sensitive transcription factors nuclear factor (kappa) B (NF-kappa B) and activator protein-1 (AP-1) in the kidneys were increased in dTGR compared with SD, and were effectively reduced. Renal glutathione levels were much higher in dTGR than in SD, while the opposite was true for cysteine levels. These results suggested increased renal glutathione oxidation in dTGR, leading to cysteine shortage. Lipoic acid partly prevented renal cysteine depletion and increased hepatic cysteine and glutathione concentrations. This effect was accompanied by increased hepatic gamma-glutamylcysteine synthetase mRNA expression. CONCLUSION: Our in vivo results suggest that lipoic acid protects against Ang II-induced renal injury through anti-inflammatory/antioxidative mechanisms. The effects are associated with decreased NF-kappa B and AP-1 activation, as well as improved thiol homeostasis.

[A comparative study of the activity of a natural peptide complex in the kidneys and its synthetic analogs in autoimmune nephritis]. / Sravnitel'noe izuchenie aktivnosti estestvennogo peptidnogo kompleksa pochek i ego sinteticheskikh analogov pri autoimmunnom nefrite.

The activity of the natural peptide complex of the kidneys and of its synthetic analogs (PEKDLRK, PEKDSRK, PEKDDRL) in autoimmune nephritis was studied on golden hamsters. All the peptides under study demonstrated therapeutic activity but were characterized by peculiarity of their effect. The peptide PEKDLRK possessed the most marked capacity for stimulating phagocytic reactions, PEKDDRL apparently activated the system of natural killers. It is concluded that the study of peptides-analogs as potential drugs is promising.

Cyclosporin A reduces albuminuria in experimental anti-GBM nephritis independently from changes in GFR.

Cyclosporin A (CsA) can reduce proteinuria in various forms of human and experimental glomerulonephritis. This antiproteinuric effect of CsA may be the consequence of diminution of immunological damage, a drug-induced decrease of GFR, or changes in permselectivity of the glomerular basement membrane (GBM). We studied the antiproteinuric effect of CsA in the heterologous phase of a passively induced anti-GBM nephritis in the mouse. This passive model is characterized by acute exudative glomerular lesions and a dose-dependent albuminuria. Rabbit anti-mouse GBM antibodies were administered intravenously in C57B110 mice at day 4, after 3 days of pretreatment with either CsA (75 mg/kg body weight) (n = 15) or olive oil (OO, controls, n = 15) orally. CsA did not influence the severity of the histological lesions. Albuminuria was substantially reduced by CsA (CsA 1.6 +/- 1.8; OO 5.6 +/- 3.2 mg/18 h; P < 0.002). There was a considerable concomitant reduction of the GFR by CsA, as measured with a 51Cr-EDTA single-shot plasma clearance technique before (day-1) and during treatment (day 4): GFR ratio day 4/day-1 for CsA, 0.4 +/- 0.1; for OO controls, 1.1 +/- 0.6; P < 0.01. This drug-induced decrease of GFR was prevented by simultaneous treatment with phenoxybenzamine (PB) twice daily 45 micrograms orally for 4 days (GFR ratio day 4/day-1 for PB and CsA, 0.9 +/- 0.4; controls (PB and OO), 1.0 +/- 0.4; P = NS). Although the CsA-induced GFR reduction was prevented, CsA still reduced albuminuria significantly (PB and CsA, 2.2 +/- 1.8; controls (PB and OO), 5.6 +/- 1.8 mg/18 h; P = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

[A preliminary study on the red cell immune function in blood stasis syndrome in traditional Chinese medicine].

20 patients with blood stasis syndrome (BSS), 20 patients with non-blood stasis syndrome (NBSS), and 17 normal subjects were measured by tests of RBC-C3b receptor rosette and RBC immune complex rosette. The rates of RBC-C3b receptor rosette formation (RBC-C3b RR, %) in BSS group, NBSS group and normal subjects were 20.90 +/- 4.02, 12.88 +/- 3.29 and 16.74 +/- 4.13 (P less than 0.01) respectively. The rates of RBC immune complex rosette formation (RBC-IC R, %) in the three groups were respectively 8.28 +/- 3.68, 7.73 +/- 2.48 and 7.41 +/- 2.43 (P less than 0.05). RBC-C3b RR was correlated to RBC-IC R in the normal subjects (r = 0.695, P less than 0.001). In patients with the same disease, RBC-C3b RR between the two syndromes (BSS and NBSS) was also very significantly different (P less than 0.01). This study suggested that there are variations on red cell immune function in BSS patients, and also provided an evidence that different syndromes of traditional Chinese medicine exist in diseases.

A fish oil diet preserves renal function in nephrotoxic serum nephritis.

Fish oil diets preserve renal function in murine lupus, but we have found that these diets accelerate renal deterioration in renoprival nephropathy. In this study we examined the effects of dietary fish oil in accelerated nephrotoxic serum nephritis. For 1 month, 14 female rats were fed diets that differed only in fat composition, containing either menhaden (fish) oil or beef tallow (control). Rats were then preimmunized with rabbit IgG and, 5 days later, were injected with nephrotoxic serum. Glomerular filtration rate (GFR) was measured continuously in conscious animals by means of intraperitoneal 14C-labeled inulin minipumps. Fish oil-containing diets markedly attenuated the nephrotoxic serum-induced decline in GFR and the rise in proteinuria and significantly reduced glomerular prostaglandin E2 and thromboxane A2. The results of tests of renal histology showed no differences between the two groups. Five days after preimmunization, rats fed fish oil had more rabbit IgG remaining in their serum and had mounted less of an antibody response to the rabbit IgG. Fish oil diets also resulted in an attenuated disappearance of injected 14C-labeled rabbit IgG. In vitro, peritoneal macrophages from rats fed fish oil took up less rabbit IgG than macrophages from rats fed control diets. Thus the beneficial effects of a fish oil diet may result from defective immune surveillance and from alterations in eicosanoids.

Effect of thyroparathyroidectomy and parathyroidectomy on renal function and the nephrotic syndrome in rat nephrotoxic serum nephritis.

Dietary phosphorus restriction (PR) prevents uremia in rats with nephrotoxic serum nephritis (NSN). One possible mechanism by which PR could be protective would be through the suppression of parathyroid hormone. To evaluate this possibility two separate protocols were designed. In the first rats were thyroparathyroidectomized (TPTX) before (n = 11) or 5 wk after (n = 7) NSN induction and compared to sham-operated parathyroid intact rats with NSN (n = 12). At the end of the 23-wk study, intact rats were azotemic, plasma creatinine 3.80+/-0.81 mg/100 ml vs. 0.65+/-0.07 for TPTX rats (P < 0.001). During the study 75% of intact rats died of uremia in contrast to none of the TPTX rats (P < 0.001). Renal histological damage was greatly diminished and calcification prevented in TPTX rats. The proteinuria of the heterologous phase was unaffected, but the protein excretion and hypertriglyceridemia (HTG) of the autologous phase were markedly decreased in the TPTX rats. The degree of HTG and proteinuria had a high positive correlation (P < 0.001). Late TPTX also produced significant decreases in proteinuria and HTG regardless of the degree of azotemia, and prevented azotemia if the plasma creatinine at the time of TPTX was

Biochemical criteria for the evaluation of drug efficiency on adjuvant arthritis and nephrotoxic serum nephritis in the rat: studies with phenylbutazone, L-Asparaginase, colchicine, lysine acetylsalicylate, and pyridinol carbamate.

The levels of serum orosomucoid, haptoglobin, and seromucoid were evaluated as possible quantitative criteria for the estimation of drug efficiency in adjuvant arthritis and nephrotoxic serum nephritis. In adjuvant arthritis, haptoglobin, seromucoid, and chiefly orosomucoid serum levels were generally very sensitive to anti-inflammatory agents such as phenylbutazone and pyridinol carbamate, and to immunosuppressive agents such as L-asparaginase. There was a significant correlation between the serum levels of these glycoproteins and the arthritis scores. In nephrotoxic serum nephritis, seromucoid levels were correlated with the proteinuria of the autologous phase and were found to be a good complementary criterion for the analysis of the efficiency of pyridinol carbamate, colchicine, iysine acetylsalicylate, and L-asparaginase.