Nuclear NF-κB p65 in peripheral blood mononuclear cells correlates with urinary MCP-1, RANTES and the severity of type 2 diabetic nephropathy

Role of Inflammation and the NF-κB Signaling Pathway in Hirschsprung's Disease

Hirschsprung's disease (HSCR, incidence 1/5000 live births) is caused by the failure of neural crest-derived precursors to migrate, survive, proliferate, or differentiate during the embryonic development of the Enteric Nervous System (ENS), which could be disrupted by many factors, including inflammatory processes. The NF-κB family controls several biological processes, including inflammation, neurogenesis, and cell migration. With the aim of studying the potential role of NF-κB in HSCR, we have analyzed the expression of the NF-κB main subunits and other NF-κB-related genes by RT-qPCR in HSCR tissue samples (sub-divided into ganglionic and aganglionic segments). We found decreased gene expression of the NF-κB main subunit RELA but also of NFKBIA, TNFA, TFGBR2, and ERBB3 in the pathologic distal aganglionic segments compared to the proximal ganglionic segments. Moreover, we could also confirm the lower protein expression of RelA/p65 in the aganglionic distal segments by immunofluorescence staining. Further, we show that the expression of RelA/p65 protein in the proximal segments concurs with lymphocyte infiltration in the bowel tissue, indicating a pro-inflammatory activation of p65 in the proximal ganglionic HSCR tissue in the patients analyzed. All in all, our findings suggest that the modulation of NF-κB signaling in the neuro-enteric system does obviously contribute to the pathological effects of HSCR.

Plasma MCP-1 and TGF-β1 Levels are Associated with Kidney Injury in Children with Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are primarily causal for end-stage renal disease and have significant implications for long-term survival. A total of 39 healthy controls and 94 children with chronic kidney disease (CKD) were enrolled (3-12 years old as children, 13-18 years old as adolescents), who were divided into CAKUT and Non-CAKUT according to the etiology of CKD. CKD group was further classified according to estimating glomerular filtration rate (eGFR). Circulating levels of inflammatory markers such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemokine-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) were analyzed. The relationship between these inflammatory markers with eGFR and the kidney injury parameter (urine protein) was investigated to assess their potential as early markers of disease progression. All circulating levels of these inflammatory cytokines were increased in CKD patients (including CAKUT and Non-CAKUT) compared with healthy subjects. The circulating levels of MCP-1 and TGF-β1 were increased in CAKUT adolescents compared with CAKUT children. In CAKUT children, levels of MCP-1 and TGF-β1 increased as CKD progressed, and MCP-1 and TGF-β1 were negatively and significantly correlated with eGFR and positively with urine protein. MCP-1 and TGF-β1 may contribute to the early detection of CKD and disease stage/progression in CAKUT children.

Understanding the lncRNA/miRNA-NFκB regulatory network in Diabetes Mellitus: From function to clinical translation

Diabetes mellitus (DM) and its significant ramifications make out one of the primary reasons behind morbidity worldwide. Noncoding RNAs (ncRNAs), such as microRNAs and long noncoding RNAs, are involved in regulating manifold biological processes, including diabetes initiation and progression. One of the established pathways attributed to DM development is NF-κB signaling. Neurons, β cells, adipocytes, and hepatocytes are among the metabolic tissues where NF-κB is known to produce a range of inflammatory chemokines and cytokines. The direct or indirect role of ncRNAs such as lncRNAs and miRNAs on the NF-κB signaling pathway and DM development has been supported by many studies. As a result, effective diabetes treatment and preventive methods will benefit from a comprehensive examination of the interplay between NF-κB and ncRNAs. Herein, we provide a concise overview of the role of NF-κB-mediated signaling pathways in diabetes mellitus and its consequences. The reciprocal regulation of ncRNAs and the NF-κB signaling pathway in diabetes is then discussed, shedding light on the pathogenesis of the illness and its possible therapeutic interventions.

Gold Nanoparticles Supported on Ceria Nanoparticles Modulate Leukocyte-Endothelium Cell Interactions and Inflammation in Type 2 Diabetes

Gold-ceria nanoparticles (Au/CeO2) are known to have antioxidant properties. However, whether these nanoparticles can provide benefits in type 2 diabetes mellitus (T2D) remains unknown. This work aimed to study the effects of Au/CeO2 nanoparticles at different rates of gold purity (10, 4.4, 1.79 and 0.82) on leukocyte-endothelium interactions and inflammation in T2D patients. Anthropometric and metabolic parameters, leukocyte-endothelium interactions, ROS production and NF-κB expression were assessed in 57 T2D patients and 51 healthy subjects. T2D patients displayed higher Body Mass Index (BMI) and characteristic alterations in carbohydrate and lipid metabolism. ROS production was increased in leukocytes of T2D patients and decreased by Au/CeO2 at 0.82% gold. Interestingly, Au/CeO2 0.82% modulated leukocyte-endothelium interactions (the first step in the atherosclerotic process) by increasing leukocyte rolling velocity and decreasing rolling flux and adhesion in T2D. A static adhesion assay also revealed diminished leukocyte-endothelium interactions by Au/CeO2 0.82% treatment. NF-κB (p65) levels increased in T2D patients and were reduced by Au/CeO2 treatment. Cell proliferation, viability, and apoptosis assays demonstrated no toxicity produced by Au/CeO2 nanoparticles. These results demonstrate that Au/CeO2 nanoparticles at 0.82% exert antioxidant and anti-inflammatory actions in the leukocyte-endothelium interaction of T2D patients, suggesting a protective role against the appearance of atherosclerosis and cardiovascular diseases when this condition exists.

Immune responses in diabetic nephropathy: Pathogenic mechanisms and therapeutic target

Diabetic nephropathy (DN) is a chronic, inflammatory disease affecting millions of diabetic patients worldwide. DN is associated with proteinuria and progressive slowing of glomerular filtration, which often leads to end-stage kidney diseases. Due to the complexity of this metabolic disorder and lack of clarity about its pathogenesis, it is often more difficult to diagnose and treat than other kidney diseases. Recent studies have highlighted that the immune system can inadvertently contribute to DN pathogenesis. Cells involved in innate and adaptive immune responses can target the kidney due to increased expression of immune-related localization factors. Immune cells then activate a pro-inflammatory response involving the release of autocrine and paracrine factors, which further amplify inflammation and damage the kidney. Consequently, strategies to treat DN by targeting the immune responses are currently under study. In light of the steady rise in DN incidence, this timely review summarizes the latest findings about the role of the immune system in the pathogenesis of DN and discusses promising preclinical and clinical therapies.

Diabetic nephropathy patients show hyper-responsiveness to N6-carboxymethyllysine

The aim of this study was to evaluate the impact of N6-carboxymethyllysine (CML) on NF-κB gene expression and tumor necrosis factor (TNF) production in diabetic nephropathy. This was an observational study comprised of three groups: diabetic nephropathy (n=30), type II diabetes mellitus (n=28), and healthy volunteers (n=30). Blood samples collected from the study participants were cultured for 24 h in the presence of CML or an appropriate control. After incubation, the cultures were centrifuged to separate the cells from the conditioned media. cDNA was prepared from the cell pellet and used to quantify NF-κB gene expression by quantitative real-time polymerase chain reaction (PCR). The conditioned media were used to measure TNF production by enzyme-linked immunosorbent assay (ELISA). The CML-induced fold change in NF-κB gene expression was significantly different among the study groups (P=5.4×10^-5). Also, the CML-induced fold change in TNF levels was significantly different among the three groups (P=4.3×10^-8). These results imply that patients with diabetic nephropathy and type II diabetes mellitus showed an elevated response to CML.

The role of CDH2 and MCP-1 mRNAs of blood extracellular vesicles in predicting early-stage diabetic nephropathy

Background

Extracellular vesicles (EVs), including exosomes and microvesicles, are involved in intercellular communication by transferring biomolecules such as mRNA, which has been shown to be as essential biomarkers for many physiological and pathological conditions such as diabetic nephropathy (DN). This study aimed to investigate the expression of CDH1, CDH2, MCP-1, and PAI-1 mRNAs in blood EVs of DN patients and to determine their accuracy in predicting early-stage DN.

Methods

We recruited 196 participants, including 35 overt DN patients, 53 incipient DN patients, 62 diabetic patients (DM), and 46 healthy individuals. Quantification of the mRNA profile of blood EVs was performed using the qRT-PCR method. The diagnostic performance of mRNA was evaluated using receiver operating characteristic analysis.

Results

The mRNA expression of CDH2 and MCP-1 was downregulated in overt DN group (0.22-fold change and 0.15-fold change, respectively) and incipient DN group (0.60-fold change and 0.43-fold change, respectively) compared to DM group (1.72-fold change and 2.77-fold change, respectively), while PAI-1 mRNA expression decreased in incipient DN group (0.70-fold change) and DM group (0.58-fold change) compared to control. However, the expression level of CDH1 mRNA was not significantly different among the four groups (p = 0.408). Moreover, CDH2 and MCP-1 mRNAs inversely correlated with creatinine (r = -0.370 and r = -0.361, p<0.001) and Alb/Cr ratio (r = -0.355 and r = -0.297, p<0.001). 1/CDH2 mRNA also predicted overt DN with an accuracy of 0.75 (95%CI: 0.65–0.85) and incipient DN with an accuracy of 0.61 (95%CI: 0.50–0.71) while 1/MCP-1 mRNA had an accuracy of 0.66 (95%CI: 0.55–0.77) for overt DN prediction and an accuracy of 0.61 (95%CI: 0.51–0.71) for incipient DN prediction.

Conclusion

CDH2 and MCP-1 mRNAs expression in blood EVs was decreased with the development of DN, suggesting the renoprotective effect of these mRNAs in diabetic individuals. Moreover, their quantifications could serve as diagnostic biomarkers for early-stage DN.

The response of two polar monocyte subsets to inflammation

Macrophages are a central component of innate immunity that play an important role in the defense of the organism. Macrophages are highly plastic and are activated by interaction with other cells and environmental factors. In this work, we study the effect of lipopolysaccharide on macrophages derived from the two most polar (CD14+ and CD16+ monocytes) as well as the intermediate subset of blood monocytes from healthy donors and assess what happens to the subset most prone to polarization on the transcriptomic and proteomic level. It has been shown that, according to primary pro-inflammatory polarization markers, their cytokine profile, and their phagocytic activity, macrophages derived from CD14+ monocytes exhibit higher sensitivity to inducers of pro-inflammatory polarization. Flow cytometry analysis revealed increased levels of CD86, while secretome analysis demonstrated significant increase of pro-inflammatory and anti-inflammatory cytokines observed in CD14+-derived macrophages, as compared to CD16+-derived macrophages in conditioned media. Assessment of the transcriptome and proteome of CD14+-derived macrophages with further bioinformatic analysis identified the most significant differences after polarization towards the pro-inflammatory phenotype. Immune-, membrane-, IFN-γ-, cytokine-, and defense-associated pathways were found significantly prevalent, while downregulated pathways were represented by RNA binding-, housekeeping-, exocytosis-, intracellular transport-, peptide and amide metabolic-related signaling. This data could be useful for macrophage-based cell therapeutics of cancer, as it provides additional background for the manipulation of donor monocytes intended for back transplantation.

Chemokines in Prediabetes and Type 2 Diabetes: A Meta-Analysis

Background

A growing number of studies found inconsistent results on the role of chemokines in the progression of type 2 diabetes (T2DM) and prediabetes (PDM). The purpose of this meta-analysis was to summarize the results of previous studies on the association between the chemokines system and T2DM/PDM.

Methods

We searched in the databases, PubMed, Web of Science, Embase and Cochrane Library, for eligible studies published not later than March 1, 2020. Data extraction was performed independently by 2 reviewers, on a standardized, prepiloted form. Group differences in chemokines concentrations were summarized using the standardized mean difference (SMD) with a 95% confidence interval (CI), calculated by performing a meta-analysis using the random-effects model.

Results

We identified 98 relevant studies that investigated the association between 32 different chemokines and T2DM/PDM. Altogether, these studies involved 14,708 patients and 14,574 controls. Results showed that the concentrations of CCL1, CCL2, CCL4, CCL5, CCL11, CXCL8, CXCL10 and CX3CL1 in the T2DM patients were significantly higher than that in the controls, while no difference in these concentrations was found between the PDM patients and controls.

Conclusion

Progression of T2DM may be associated with elevated concentrations of chemokines.

Meta-Analysis Registration

PROSPERO, identifier CRD42019148305.

Enzyme-treated soy protein supplementation in low protein diet enhanced immune function of immune organs in on-growing grass carp

A 56 days feeding trial was conducted to investigate the effects of enzyme-treated soy protein (ETSP) supplementation in low protein diets on immune function of immune organs (head kidney, spleen and skin) in on-growing grass carp. A total of 540 on-growing grass carp (initial average weight: 325.72 ± 0.60 g) were fed six diets, which included a normal protein diet (28% crude protein) and five low protein diets (26% crude protein) supplemented with graded levels of ETSP (0.0, 0.8, 1.2, 1.6 and 2.0%). At the end of feeding period, a challenge test was performed by infection with Aeromonas hydrophila for two weeks. The results indicated that (1) reducing dietary protein content from 28 to 26% decreased antibacterial substances and aggravated inflammatory responses of above three immune organs; (2) under the condition of reducing protein level in diet, 0.8-1.2% ETSP supplementation reversed these above adverse effects on immune function of above three immune organs; (3) suitable ETSP supplementation-decreased inflammatory responses were partly associated with [IκB kinase β (IKKβ)/inhibitor of κBα (IκBα)/nuclear factor kappa B (NF-κB) p65 and p52 or NF-κB p65] signaling and [target of rapamycin (TOR)/(S6K1, 4E-BP)] signaling in above three immune organs. (4) On the basis of C3 content (head kidney), C4 content (spleen) and skin hemorrhage and lesion, the optimal ETSP supplementation levels in low protein diets were estimated to be 1.48%, 1.61% and 1.03%, respectively. In summary, ETSP supplementation in low protein diets improved immune function of head kidney, spleen and skin in on-growing grass carp.

Accelerated Kidney Aging in Diabetes Mellitus

With aging, the kidney undergoes inexorable and progressive changes in structural and functional performance. These aging-related alterations are more obvious and serious in diabetes mellitus (DM). Renal accelerated aging under DM conditions is associated with multiple stresses such as accumulation of advanced glycation end products (AGEs), hypertension, oxidative stress, and inflammation. The main hallmarks of cellular senescence in diabetic kidneys include cyclin-dependent kinase inhibitors, telomere shortening, and diabetic nephropathy-associated secretory phenotype. Lysosome-dependent autophagy and antiaging proteins Klotho and Sirt1 play a fundamental role in the accelerated aging of kidneys in DM, among which the autophagy-lysosome system is the convergent mechanism of the multiple antiaging pathways involved in renal aging under DM conditions. Metformin and the inhibitor of sodium-glucose cotransporter 2 are recommended due to their antiaging effects independent of antihyperglycemia, besides angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. Additionally, diet intervention including low protein and low AGEs with antioxidants are suggested for patients with diabetic nephropathy (DN). However, their long-term benefits still need further study. Exploring the interactive relationships among antiaging protein Klotho, Sirt1, and autophagy-lysosome system may provide insight into better satisfying the urgent medical needs of elderly patients with aging-related DN.

Targeting NF-κB by the Cell-Permeable NEMO-Binding Domain Peptide Improves Albuminuria and Renal Lesions in an Experimental Model of Type 2 Diabetic Nephropathy

Diabetic nephropathy (DN) is a multifactorial disease characterized by hyperglycemia and close interaction of hemodynamic, metabolic and inflammatory factors. Nuclear factor-κB (NF-κB) is a principal matchmaker linking hyperglycemia and inflammation. The present work investigates the cell-permeable peptide containing the inhibitor of kappa B kinase γ (IKKγ)/NF-κB essential modulator (NEMO)-binding domain (NBD) as therapeutic option to modulate inflammation in a preclinical model of type 2 diabetes (T2D) with DN. Black and tan, brachyuric obese/obese mice were randomized into 4 interventions groups: Active NBD peptide (10 and 6 µg/g body weight); Inactive mutant peptide (10 µg/g); and vehicle control. In vivo/ex vivo fluorescence imaging revealed efficient delivery of NBD peptide, systemic biodistribution and selective renal metabolization. In vivo administration of active NBD peptide improved albuminuria (>40% reduction on average) and kidney damage, decreased podocyte loss and basement membrane thickness, and modulated the expression of proinflammatory and oxidative stress markers. In vitro, NBD blocked IKK-mediated NF-κB induction and target gene expression in mesangial cells exposed to diabetic-like milieu. These results constitute the first nephroprotective effect of NBD peptide in a T2D mouse model that recapitulates the kidney lesions observed in DN patients. Targeting IKK-dependent NF-κB activation could be a therapeutic strategy to combat kidney inflammation in DN.

Condensed tannins decreased the growth performance and impaired intestinal immune function in on-growing grass carp (Ctenopharyngodon idella)

The present study investigated the effects of condensed tannins (CT) on intestinal immune function in on-growing grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp were fed six diets containing different levels of CT (0, 10·00, 20·00, 30·00, 40·00 and 50·00 g/kg diet) for 70 d and then challenged with Aeromonas hydrophila for 14 d. The results showed that, compared with the control group, dietary CT (1) induced intestinal histopathological lesions and aggravated enteritis; (2) decreased lysozyme and acid phosphatase activities, complement 3 (C3), C4 and IgM contents and down-regulated the Hepcidin, liver-expressed antimicrobial peptide (LEAP)-2A, LEAP-2B, Mucin2 and β-defensin-1 mRNA levels in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) (P < 0·05); (3) down-regulated the mRNA levels of anti-inflammatory cytokines transforming growth factor (TGF)-β1, TGF-β2 (not in MI and DI), IL-4/13A (not IL-4/13B), IL-10 and IL-11 partly correlated with target of rapamycin (TOR) signalling; and (4) up-regulated the mRNA levels of pro-inflammatory cytokines interferon-γ2, IL-1β, IL-6, IL-8 (not in PI), IL-12p35, IL-12p40, IL-15 and IL-17D partly related to NF-κB signalling in the intestine of on-growing grass carp. Overall, the results indicated that CT could impair the intestinal immune function, and its potential regulation mechanisms were partly associated with the TOR and NF-κB signalling pathways. Finally, based on the percentage weight gain and enteritis morbidity, the maximum allowable levels of CT for on-growing grass carp (232·22-890·11 g) were estimated to be 18·6 and 17·4 g/kg diet, respectively.

Podoplanin mediates the renoprotective effect of berberine on diabetic kidney disease in mice

Hyperglycemia-caused podocyte injury plays a crucial role in the progress of diabetic kidney disease. Podoplanin, one of the podocyte-associated molecules, is closely related to the integrity of the glomerular filtration barrier. A number of studies demonstrate that berberine could ameliorate renal dysfunction in diabetic mice with nephropathy, but the molecular mechanisms have not been fully elucidated. In this study, we explored the relationship between the renoprotective effect of berberine and podoplanin expression in streptozotocin (STZ)-induced diabetic mice as well as mouse podocytes (MPC5 cells) cultured in high glucose (HG, 30 mM) medium. We found that the expression levels of podoplanin were significantly decreased both in the renal glomerulus of STZ-induced diabetic mice and HG-cultured MPC5 cells. We also demonstrated that NF-κB signaling pathway was activated in MPC5 cells under HG condition, which downregulated the expression level of podoplanin, thus leading to increased podocyte apoptosis. Administration of berberine (100, 200 mg/kg every day, ig, for 8 weeks) significantly improved hyperglycemia and the renal function of STZ-induced diabetic mice and restored the expression level of podoplanin in renal glomerulus. In high glucose-cultured MPC5 cells, treatment with berberine (30–120 μM) dose-dependently decreased the apoptosis rate, increased the expression of podoplanin, and inhibited the activation of NF-κB signaling pathway. When podoplanin expression was silenced with shRNA, berberine treatment still inhibited the NF-κB signaling pathway, but its antiapoptotic effect on podocytes almost disappeared. Our results suggest that berberine inhibits the activation of NF-κB signaling pathway, thus increasing the podoplanin expression to exert renoprotective effects.

Investigating subtle kidney injury in primary hyperparathyroidism by means of sensitive and specific biomarkers

OBJECTIVE

Kidney involvement is a common complication in primary hyperparathyroidism (PHPT). No study so far has assessed the prevalence of kidney injury developing before the reduction in glomerular filtration rate (GFR) in PHPT. The study was aimed at establishing the potential role of biomarkers of kidney injury in detecting subtle renal damage in patients with PHPT.

DESIGN

Cross-sectional study.

PATIENTS

A total of 69 postmenopausal patients with PHPT and 41 healthy age- and sex-matched subjects were studied. Exclusion criteria were as follows: GFR < 30 mL/min, chronic inflammatory disease, nephrotic syndrome, infection, malignancy, heart failure, recent exposure to iodinated contrast media or nonsteroidal anti-inflammatory drugs.

MEASUREMENTS

We measured a panel of sensitive biomarkers of kidney injury in PHPT vs controls.

RESULTS

Mean FGF23 and Klotho were higher in PHPT (72 ± 48 and 811 ± 366 pg/mL, respectively) than controls (53 ± 23.5 and 668.6 ± 17; P < .02 and P < .05). Urine KIM-1/uCr was significantly higher in PHPT (1.4^-6  ± 1.3^-6 ) than controls (9.2^-7  ± 7^-7 ; P < .05); this was particularly evident in the CrCl 60-89 mL/min category (1.3⁶  ± 9⁷ vs 8.2^-7  ± 3.6^-7 ; P < .02). Mean values of urine NGAL/uCr were higher in PHPT with (n = 28) compared to those without kidney stones (n = 35; 1.8^-5  ± 1.4^-5 and 1^-5  ± 8^-6 ; P < .0001). We found significant positive associations between urine NGAL/uCr and Ca (R = .292, P < .02) and urine KIM1/uCr and PTH (R = .329, P < .01).

CONCLUSIONS

We propose the utilization of these molecules, particularly urine KIM-1/uCr and urine NGAL/uCr ratios for the assessment of subtle kidney injury in patients with PHPT. These molecules are elevated in tubular necrosis and have potential role in the development of kidney damage in PHPT, according to the severity of the disease.

Red Ginseng Reduces Inflammatory Response via Suppression MAPK/P38 Signaling and p65 Nuclear Proteins Translocation in Rats and Raw 264.7 Macrophage

Lipopolysaccharides (LPS) cause systemic inflammatory responses, which are characterized by high mortality and multiple signs, including metabolic disturbances, respiratory acidosis, hypotension, and vital organs disorder. Cytokines secretion and oxidative stress are the main features of the disease. Diagnosis and treatment of systemic inflammation (SI) remain a challenge. Korean Red Ginseng (RG) is one of medicinal herbs that showed a potent anti-oxidant effect. We aimed to study the protective effects of RG on systemic inflammatory response in rats and RAW 264.7 macrophage cells induced by LPS. The rats were treated with water and alcohol extracts of RG for four weeks to prevent the inflammatory response. The result showed that LPS toxin increased morbidity and mortality, and induced liver, kidney, and lung injuries manifested by deteriorated biomarkers. Hypotension, hypomagnesemia, acidosis, and oxidative stress were observed in septic rats. However, RG extracts attenuated liver, kidney, and lung enzymes and metabolites in treated groups via its anti-inflammatory and anti-oxidant properties. Furthermore, RG improved magnesium and blood pressure in the treated groups. RAW 264.7 macrophage cells exposed to LPS disturbance in translocation of p65 and MAPK/p38. Nevertheless, RG-pretreated cells did not significantly alter. In conclusion, RG reduced the rates of mortality and morbidity of treated rats - liver, kidney, and lung injuries were protected in the treated groups through the potentiation of anti-oxidant defense. RG was able to conserve mitochondrial function, inhibiting the activation of MAPK/p38 signaling and suppressing NF-κB p65 cytoplasm-nucleus transport. Further studies are needed to examine the effects on chronic conditions in animal models and human.

Deoxynivalenol decreased intestinal immune function related to NF-κB and TOR signalling in juvenile grass carp (Ctenopharyngodon idella)

Deoxynivalenol (DON) is one of the most common mycotoxins in animal feed worldwide and causes significant threats to the animal production. The intestine is an important mucosal immune organ in teleost, and it is also the first target for feed-borne toxicants in animal. However, studies concerning the effect of DON on fish intestine are scarce. This study explored the effects of DON on intestinal immune function in juvenile grass carp (Ctenopharyngodon idella). A total of 1440 juvenile grass carp (12.17 ± 0.01 g) were fed six diets containing graded levels of DON (27, 318, 636, 922, 1243 and 1515 μg/kg diet) for 60 days. After the growth trial, fish were challenged with Aeromonas hydrophila. The results were analysed by the Duncan's multiple-range test (P < 0.05), indicating that compared with the control group (27 μg/kg diet), dietary DON levels up to 318 μg/kg diet: (1) decreased lysozyme (LZ) and acid phosphatase (ACP) activities, as well as complement 3 (C3), C4 and immunoglobulin M (IgM) content in the proximal intestine (PI), middle intestine (MI) and distal intestine (DI) of juvenile grass carp (P < 0.05); (2) down-regulated the mRNA levels of anti-microbial substance: liver expressed antimicrobial peptide (LEAP) -2A, LEAP-2B, hepcidin, β-defensin-1 and mucin2 in the PI, MI and DI of juvenile grass carp (P < 0.05); (3) up-regulated the mRNA levels of pro-inflammatory cytokines [interleukin 1β (IL-1β), tumour necrosis factor α (TNF-α), interferon γ2 (INF-γ2), IL-6 (only in PI), IL-8, IL-12p35, IL-12p40, IL-15 and IL-17D] in the PI, MI and DI of juvenile grass carp (P < 0.05), which might be partly related to nuclear factor kappa B (NF-κB) signalling [IκB kinase β (IKKβ) and IKKγ/inhibitor of κBα (IκBα)/NF-κB (p65 and c-Rel)]; and (4) down-regulated the mRNA levels of anti-inflammatory cytokines [IL-10, IL-11, IL-4/13A (not IL-4/13B), transforming growth factor β1 (TGF-β1) (not TGF-β2)] in the PI, MI and DI of juvenile grass carp (P < 0.05), which might be partly related to target of rapamycin (TOR) signalling [TOR/ribosomal protein S6 kinases 1 (S6K1) and eIF4E-binding proteins (4E-BP)]. All data indicated that DON could impair the intestinal immune function, and its potential regulation mechanisms were partly associated with NF-κB and TOR signalling pathways. Finally, based on the enteritis morbidity, and the LZ and ACP activities as well as IgM content in the PI, the reasonable dose of DON for grass carp were estimated to be 251.66, 305.83, 252.34 and 309.94 μg/kg diet, respectively.

The mitochondrial antioxidant SS-31 increases SIRT1 levels and ameliorates inflammation, oxidative stress and leukocyte-endothelium interactions in type 2 diabetes

There is growing focus on mitochondrial impairment and cardiovascular diseases (CVD) in type 2 diabetes (T2D), and the development of novel therapeutic strategies in this context. It is unknown whether mitochondrial-targeting antioxidants such as SS-31 protect sufficiently against oxidative damage in diabetes. We aimed to evaluate if SS-31 modulates SIRT1 levels and ameliorates leukocyte-endothelium interactions, oxidative stress and inflammation in T2D patients. Anthropometric and metabolic parameters were studied in 51 T2D patients and 57 controls. Production of mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential, glutathione content, leukocyte-endothelium interactions, NFκB-p65, TNFα and SIRT1 levels was measured in leukocytes treated or not with SS-31. We observed increased mitochondrial ROS production that was restored by SS-31 treatment. SS-31 also increased mitochondrial membrane potential, glutathione content, SIRT1 levels and leukocyte rolling velocity and reduced rolling flux and adhesion in T2D patients. NFκB-p65 and TNFα, which were enhanced in diabetic patients, were also reduced by SS-31 treatment. Our results reveal that SS-31 exerts beneficial effects on the leukocytes of T2D patients by reducing oxidative stress, leukocyte-endothelium interactions, NFκB and TNFα and by increasing SIRT1 levels. These actions support its use as a potential agent against CVD risk.

Vitamin D protects against diabetic nephropathy: Evidence-based effectiveness and mechanism

Vitamin D has been suggested to harbor multiple biological activities, among them the potential of vitamin D in the protection of diabetic nephropathy (DN) has attracted special attention. Both animal studies and clinical trials have documented an inverse correlation between low vitamin D levels and DN risk, and supplementation with vitamin D or its active derivatives has been demonstrated to improve endothelial cell injury, reduce proteinuria, attenuate renal fibrosis, and resultantly retard DN progression. Vitamin D exerts its pharmacological effects primarily via vitamin D receptor, whose activation inhibits the renin-angiotensin system, a key culprit for DN under hyperglycemia. The anti-DN benefit of vitamin D can be enhanced when administrated in combination with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. Mechanistic studies reveal that pathways relevant to inflammation participate in the pathogenesis of DN, however, consumption of vitamin D-related products negatively regulates inflammatory response at multiple levels, indicated by inhibiting macrophage infiltration, nuclear factor-kappa B (NF-κB) activation, and production of such inflammatory mediators as transforming growth factor-β(TGF-β), monocyte chemoattractant protein 1(MCP-1), and regulated upon activation normal T cell expressed and secreted protein(RANTES). The robust anti-inflammatory property of vitamin D-related products allows them with a promising renoprotective therapeutic option for DN. This review summarizes new advances in our understanding of vitamin D-related products in the DN management.

Ursolic acid improves diabetic nephropathy via suppression of oxidative stress and inflammation in streptozotocin-induced rats

Inflammation plays a pivotal role in the pathogenesis of diabetic nephropathy (DN). Overexpression of inflammatory chemokine and cytokines is involved in the development of DN. Ursolic acid (UA), a common pentacyclic triterpenoid compound, has been reported to have myriad benefits and medicinal properties. However, its protective effects against renal injury in streptozotocin (STZ)-induced diabetic rats have not been firmly established. In the current report, we investigated whether UA inhibits oxidative stress and inflammation in the kidneys of STZ-induced diabetic rats. Diabetes mellitus (DM) was induced by STZ (40 mg/ kg, i.v.). Animals were randomly divided into control group (normal saline, i.g.), DN group (normal saline, i.g.), DN + UA group (35 mg/kg UA + normal saline, i.g.) and DN + telmisartan group (12 mg/kg telmisartan + normal saline, i.g.). Fasting blood glucose (FBG) levels were monitored at regular intervals. The administration of compounds started at 5th week and lasted for 8 weeks. At the beginning of 13th week, rats were humanely euthanized, KW/BW, BUN, SCr, SOD and MDA were measured. Histopathological changes in renal tissue were observed after hematoxylin-eosin (HE) staining. Furthermore, the expressions of TNF-α, MCP-1 and IL-1β in kidney were determined by immunohistochemistry and western blot. Our results showed that UA significantly lowered the levels of FBG, KW/BW, BUN, SCr and MDA in diabetic rats. Additionally, the SOD activity in UA treated group was higher than that in DN group. Furthermore, renal structural abnormalities and the elevation of TNF-α, MCP-1 and IL-1β expression level were blocked by the administration of UA. In conclusion, our data demonstrate that UA could be well used as a protective agent to counter renal dysfunction - through antioxidant and anti-inflammatory effects.

Selenium deficiency impaired immune function of the immune organs in young grass carp (Ctenopharyngodon idella)

This study aimed to investigate the effects of dietary selenium on resistance to skin haemorrhages and lesions and on immune function as well as the underlying mechanisms of those effects in the head kidney, spleen and skin of young grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp with initial body weight (226.48 ± 0.68 g) were randomly divided into six groups and fed six separate diets with graded dietary levels of selenium (0.025, 0.216, 0.387, 0.579, 0.795 and 1.049 mg/kg diet) for 80 days. After the feeding period, an immunization trial was performed by infection with Aeromonas hydrophila for 14 days. The results showed that, compared with the optimal selenium level, (1) selenium deficiency impaired the production of antibacterial compounds and immunoglobulins and down-regulated the transcript abundances of antimicrobial peptides and selenoproteins; (2) selenium deficiency aggravated inflammatory responses in part by up-regulating pro-inflammatory cytokines and down-regulating anti-inflammatory cytokines mRNA levels, which were partially related to [IKKα, β, γ/IκBα/NF-κB] signalling and [TOR/(S6K1, 4E-BP1)] signalling, respectively. Interestingly, selenium deficiency had no effect on the expression of TGF-β2, IL-4/13B, IL-10, IL-12p35, IL-15 (skin only) or 4E-BP2 in the head kidney, spleen and skin of young grass carp. Finally, based on the percent weight gain (PWG), the morbidity of skin haemorrhages and lesions, the ACP activity in the head kidney and the lysozyme activity in spleen, the optimal dietary selenium requirements for young grass carp were estimated to be 0.546-0.604 mg/kg diet. In summary, selenium deficiency decreased the growth performance and impaired the immune function in the head kidney, spleen and skin of young grass carp.

Rapeseed protein-derived antioxidant peptide RAP alleviates renal fibrosis through MAPK/NF-κB signaling pathways in diabetic nephropathy

Introduction

Kidney fibrosis is the main pathologic change in diabetic nephropathy (DN), which is the major cause of end-stage renal disease. Current therapeutic strategies slow down but cannot reverse the progression of renal dysfunction in DN. Plant-derived bioactive peptides in foodstuffs are widely used in many fields because of their potential pharmaceutical and nutraceutical benefits. However, this type of peptide has not yet been studied in renal fibrosis of DN. Previous studies have indicated that the peptide YWDHNNPQIR (named RAP), a natural peptide derived from rapeseed protein, has an antioxidative stress effect. The oxidative stress is believed to be associated with DN. The aim of this study was to evaluate the pharmacologic effects of RAP against renal fibrosis of DN and high glucose (HG)-induced mesangial dysfunction.

Materials and methods

Diabetes was induced by streptozotocin and high-fat diet in C57BL/6 mice and these mice were treated by subcutaneous injection of different doses of RAP (0.1 mg/kg and 0.5 mg/kg, every other day) or PBS for 12 weeks. Later, functional and histopathologic analyses were performed. Parallel experiments verifying the molecular mechanism by which RAP alleviates DN were carried out in HG-induced mesangial cells (MCs).

Results

RAP improved the renal function indices, including 24-h albuminuria, triglyceride, serum creatinine, and blood urea nitrogen levels, but did not lower blood glucose levels in DN mice. RAP also simultaneously attenuated extracellular matrix accumulation in DN mice and HG-induced MCs. Furthermore, RAP reduced HG-induced cell proliferation, but it showed no toxicity in MCs. Additionally, RAP inhibited the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signaling pathways.

Conclusion

RAP can attenuate fibrosis in vivo and in vitro by antagonizing the MAPK and NF-κB pathways.

Role of the Immune System in Diabetic Kidney Disease

PURPOSE OF REVIEW

The purpose of this review is to examine the proposed role of immune modulation in the development and progression of diabetic kidney disease (DKD).

RECENT FINDINGS

Diabetic kidney disease has not historically been considered an immune-mediated disease; however, increasing evidence is emerging in support of an immune role in its pathophysiology. Both systemic and local renal inflammation have been associated with DKD. Infiltration of immune cells, predominantly macrophages, into the kidney has been reported in a number of both experimental and clinical studies. In addition, increased levels of circulating pro-inflammatory cytokines have been linked to disease progression. Consequently, a variety of therapeutic strategies involving modulation of the immune response are currently being investigated in diabetic kidney disease. Although no current therapies for DKD are directly based on immune modulation many of the therapies in clinical use have anti-inflammatory effects along with their primary actions. Macrophages emerge as the most likely beneficial immune cell target and compounds which reduce macrophage infiltration to the kidney have shown potential in both animal models and clinical trials.

Tangshen formula improves inflammation in renal tissue of diabetic nephropathy through SIRT1/NF-κB pathway

The present study investigated the mechanism underlying the anti-inflammatory effects of Tangshen formula (TS) in Sprague Dawley (SD) rats with diabetic nephropathy (DN). A rat model of DN was established by intraperitoneal injection of 1% (40 mg/kg) streptozotocin and administration of a high fat and glucose diet. Subsequently, SD rats were randomly divided into six groups (n=8): A DN group, a valsartan group, a high-dose TS group, a middle-dose TS group, a low-dose TS group and a control group with normal SD rats. Once rats received their allocated treatment for 12 weeks, body weight and kidney weight were recorded, and fasting blood glucose, ratio of urinary protein, β₂-MG and creatinine clearance rate were determined. Furthermore, hemodynamic indices, including plasma viscosity and whole blood reduction viscosity were detected. Immunohistochemistry was used to detect the infiltration of macrophages in the kidneys of rats. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to investigate the activation; mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1), macrophage migration inhibitory factor (MIF), nuclear factor-κB (NF-κB) and sirtuin-1 (SIRT1) in each group. In comparison with the DN group, each biochemical indicator of rats in the high-dose TS group was significantly decreased (P<0.05). Blood viscosity in each treatment group was significantly decreased when compared with the DN group (P<0.01). Hematoxylin and eosin staining indicated that the infiltration of macrophages was significantly decreased in the high-dose TS group when compared with the DN group (P<0.01). mRNA and protein expression levels of MCP-1 and MIF in the high-dose TS group were significantly decreased when compared with the DN group (P<0.05). In the treatment groups, SITR1 mRNA expression levels were significantly increased, whereas the mRNA expression levels of NF-κB were significantly decreased (P<0.01). Western blotting results indicated a significant decrease in the protein expression levels of acetylated NF-κB in the treatment groups when compared with the DN group (P<0.01) and the propensity of protein expression of the other inflammatory factors were consistent with the mRNA findings. The results of the high-dose TS group were similar to those of the valsartan group. The present study indicates that TS was able to activate SITR1, which lead to NF-κB deacetylation, thus reducing the release of inflammatory factors and decreasing the severity of diabetic nephropathy.

Effect of a single intravenous zoledronic acid administration on biomarkers of acute kidney injury (AKI) in patients with osteoporosis: a pilot study

AIMS

The pilot study was designed to evaluate the early effect of intravenous (i.v.) zoledronic acid (ZA) on renal function.

METHODS

Five mg i.v. ZA was administered to 23 patients with osteoporosis (17 women and 6 men, mean age 73 ± 7 SD years). Urinary NGAL, KIM-1, and MCP-1, plasma (p) MCP-1 and serum (s) IL-18, serum calcium (sCa), Creatinine clearance (CrCl), parathyroid hormone (PTH), plasma C-terminal FGF23 (pFGF23), serum (s) Klotho, calcium excretion (CaEx) and renal threshold phosphate concentration/GFR (TmPO₄ /GFR) were assessed at baseline, 24 h and Day 30 after administration.

RESULTS

There was a significant decrease in sCa and CaEx at 24 h (-4.1 ± 2.8%, P < 0.01 and -28 ± 59%, P < 0.05, respectively) and Day 30 (-3.9 ± 4%, P < 0.001 and -26 ± 43%, P < 0.01) and a significant increase in PTH (79.8 ± 95.8%) at Day 30 (P < 0.001) compared to baseline. TmPO₄ /GFR decreased significantly at 24 h and Day 30 (-8.6 ± 15.9%, P < 0.05 and -11.3 ± 13.5%, P < 0.001) compared to baseline. We observed no difference in the concentration of pFGF23, sKlotho and urinary AKI biomarkers at any time points. Mean levels of sIL-18 and pMCP-1 increased significantly at 24 h (44 ± 88%; P < 0.01 and 198 ± 237%; P < 0.001) and returned to baseline at Day 30.

CONCLUSIONS

Our pilot study suggests that there is no direct acute effect of ZA on kidney function. The increase in plasma MCP-1 and serum IL-18 concentration could be associated with the stimulation of immunity mechanisms occurring soon after the administration of the drug. Secondary hyperparathyroidism develops shortly after the infusion of ZA and is maintained even after 1 month.

Renoprotective Effect of the Shen-Yan-Fang-Shuai Formula by Inhibiting TNF-α/NF-κB Signaling Pathway in Diabetic Rats

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease, and satisfactory therapeutic strategies have not yet been established. The Shen-Yan-Fang-Shuai Formula (SYFSF) is a traditional Chinese formula composed of Astragali radix, Radixangelicae sinensis, Rheum officinale Baill, and four other herbs. It has been widely used as an effective treatment for DKD patients in China. However, little is known about the molecular mechanisms underlying SYFSF's renoprotection. In this study, we compared the protective effect of SYFSF to irbesartan on the histology and renal cells in type 2 DKD rat model and high-glucose (HG) cultured mesangial cells, respectively. We found that SYFSF could significantly decrease urinary albumin, cholesterol, and triglyceride. And a decrease in serum creatinine was also found in SYFSF-treated group compared with irbesartan-treated rats. In addition, SYFSF inhibited the interstitial expansion and glomerulosclerosis in diabetic rats. Notably, SYFSF markedly downregulated the expression of MCP-1, TGF-β1, collagen IV, and fibronectin in diabetic rat models and HG-induced mesangial cell models. The renoprotection was closely associated with a reduced expression of TNF-α and phosphorylated NF-κBp65. Our study suggests that SYFSF may ameliorate diabetic kidney injury. The observed renoprotection is probably attributable to an inhibition of inflammatory response and extracellular matrix (ECM) accumulation mediated by TNF-α/NF-κBp65 signaling pathway.

Targeting heme oxygenase-1 in early diabetic nephropathy in streptozotocin-induced diabetic rats

Diabetic nephropathy (DN) is one of the most common microvascular diabetic complications. This study was designed to evaluate the possible protective effect and underlying mechanisms of HO-1 induction in streptozotocin (STZ)-induced early DN in rats. The diabetic rats were divided into three groups: STZ-diabetic, cobalt protoporphyrin (CoPP)-treated diabetic, and zinc protoporphyrin IX (ZnPP)-treated diabetic groups. Compared to the STZ-diabetic group, CoPP-induced HO-1 upregulation improved the diabetic state and renal functional parameters, suppressed the renal proinflammatory marker, NF-κB, abrogated the elevated renal hydroxyprolin, and decreased the enhanced renal nicotinamide adenine dinucleotide phosphate oxidase activity with parallel reduction of urinary oxidative stress markers. On the contrary, treatment with ZnPP abrogated HO-1 levels, aggravated the diabetic condition with further increases in renal oxidative stress, fibrotic and inflammatory markers, and exacerbated renal dysfunction in diabetic animals. These findings suggest that the reduced diabetic renal injury upon HO-1 induction implicates the role of HO-1 induction as a potential treatment for DN.

Apigenin ameliorates streptozotocin-induced diabetic nephropathy in rats via MAPK-NF-κB-TNF-α and TGF-β1-MAPK-fibronectin pathways

Diabetic nephropathy (DN), a microvascular complication of diabetes, has emerged as an important health problem worldwide. There is strong evidence to suggest that oxidative stress, inflammation, and fibrosis play a pivotal role in the progression of DN. Apigenin has been shown to possess antioxidant, anti-inflammatory, antiapoptotic, antifibrotic, as well as antidiabetic properties. Hence, we evaluated whether apigenin halts the development and progression of DN in streptozotocin (STZ)-induced diabetic rats. Male albino Wistar rats were divided into control, diabetic control, and apigenin treatment groups (5-20 mg/kg po, respectively), apigenin per se (20 mg/kg po), and ramipril treatment group (2 mg/kg po). A single injection of STZ (55 mg/kg ip) was administered to all of the groups except control and per se groups to induce type 1 diabetes mellitus. Rats with fasting blood glucose >250 mg/dl were included in the study and randomized to different groups. Thereafter, the protocol was continued for 8 mo in all of the groups. Apigenin (20 mg/kg) treatment attenuated renal dysfunction, oxidative stress, and fibrosis (decreased transforming growth factor-β1, fibronectin, and type IV collagen) in the diabetic rats. It also significantly prevented MAPK activation, which inhibited inflammation (reduced TNF-α, IL-6, and NF-κB expression) and apoptosis (increased expression of Bcl-2 and decreased Bax and caspase-3). Furthermore, histopathological examination demonstrated reduced inflammation, collagen deposition, and glomerulosclerosis in the renal tissue. In addition, all of these changes were comparable with those produced by ramipril. Hence, apigenin ameliorated renal damage due to DN by suppressing oxidative stress and fibrosis and by inhibiting MAPK pathway.

Gene and protein expressions and metabolomics exhibit activated redox signaling and wnt/β-catenin pathway are associated with metabolite dysfunction in patients with chronic kidney disease

Changes in plasma concentration of small organic metabolites could be due to their altered production or urinary excretion and changes in their urine concentration may be due to the changes in their filtered load, tubular reabsorption, and/or altered urine volume. Therefore, these factors should be considered in interpretation of the changes observed in plasma or urine of the target metabolite(s). Fasting plasma and urine samples from 180 CKD patients and 120 age-matched healthy controls were determined by UPLC-HDMS-metabolomics and quantitative real-time RT-PCR techniques. Compared with healthy controls, patients with CKD showed activation of NF-κB and up-regulation of pro-inflammatory and pro-oxidant mRNA and protein expression as well as down-regulation of Nrf2-associated anti-oxidant gene mRNA and protein expression, accompanied by activated canonical Wnt/β-catenin signaling. 124 plasma and 128 urine metabolites were identified and 40 metabolites were significantly altered in both plasma and urine. Plasma concentration and urine excretion of 25 metabolites were distinctly different between CKD and controls. They were related to amino acid, methylamine, purine and lipid metabolisms. Logistic regression identified four plasma and five urine metabolites. Parts of them were good correlated with eGFR or serum creatinine. 5-Methoxytryptophan and homocystine and citrulline were good correlated with both eGFR and creatinine. Clinical factors were incorporated to establish predictive models. The enhanced metabolite model showed 5-methoxytryptophan, homocystine and citrulline have satisfactory accuracy, sensitivity and specificity for predictive CKD. The dysregulation of CKD was related to amino acid, methylamine, purine and lipid metabolisms. 5-methoxytryptophan, homocystine and citrulline could be considered as additional GFR-associated biomarker candidates and for indicating advanced renal injury. CKD caused dysregulation of the plasma and urine metabolome, activation of inflammatory/oxidative pathway and Wnt/β-catenin signaling and suppression of antioxidant pathway.

The mitochondria-targeted antioxidant MitoQ modulates oxidative stress, inflammation and leukocyte-endothelium interactions in leukocytes isolated from type 2 diabetic patients

It is not known if the mitochondria-targeted antioxidants such as mitoquinone (MitoQ) can modulate oxidative stress and leukocyte-endothelium interactions in T2D patients. We aimed to evaluate the beneficial effect of MitoQ on oxidative stress parameters and leukocyte-endothelium interactions in leukocytes of T2D patients. The study population consisted of 98 T2D patients and 71 control subjects. We assessed metabolic and anthropometric parameters, mitochondrial reactive oxygen species (ROS) production, glutathione peroxidase 1 (GPX-1), NFκB-p65, TNFα and leukocyte-endothelium interactions. Diabetic patients exhibited higher weight, BMI, waist circumference, SBP, DBP, glucose, insulin, HOMA-IR, HbA1c, triglycerides, hs-CRP and lower HDL-c with respect to controls. Mitochondrial ROS production was enhanced in T2D patients and decreased by MitoQ. The antioxidant also increased GPX-1 levels and PMN rolling velocity and decreased PMN rolling flux and PMN adhesion in T2D patients. NFκB-p65 and TNFα were augmented in T2D and were both reduced by MitoQ treatment. Our findings support that the antioxidant MitoQ has an anti-inflammatory and antioxidant action in the leukocytes of T2D patients by decreasing ROS production, leukocyte-endothelium interactions and TNFα through the action of NFκB. These data suggest that mitochondria-targeted antioxidants such as MitoQ should be investigated as a novel means of preventing cardiovascular events in T2D patients.

miR-451 suppresses the NF-kappaB-mediated proinflammatory molecules expression through inhibiting LMP7 in diabetic nephropathy

Activation of nuclear factor -kappa B (NF-κB) is associated with inflammation in the progression of diabetic nephropathy (DN). MiR-451 is closely linked to renal damage in DN. Large multifunctional protease 7 (LMP7), an immunoproteasome subunit, can activate NF-κB. However, it remained unclear whether miR-451 affected NF-κB-induced inflammation by regulating LMP7 in DN. In this study, deep sequencing, in situ hybridization, quantitative real-time PCR, dual-luciferase reporter gene assays, western blot and chromatin immunoprecipitation were respectively used. For the results, we found that miR-451 was markedly downregulated in the kidneys of db/db mice, PBMCs of DN patients and mesangial cells (MCs) cultured in high glucose conditions. Furthermore, miR-451 directly targeted LMP7 expression to inhibit NF-κB activity, and down-regulated transcription of proinflammatory molecules in MCs. More importantly, in the kidneys of db/db DN mice, increasing miR-451 level inhibited LMP7/NF-κB activity, and attenuated the urinary microalbumin excretion, blood glucose, and glomerular injury. In conclusion, these results provide new insights into the regulation of miR-451 via the LMP7/NF-κB central inflammatory pathway during progression of DN.

Involvement of the NF-κB signaling pathway in the renoprotective effects of isorhamnetin in a type 2 diabetic rat model

The aim of the present study was to investigate the renoprotective effects of isorhamnetin (ISO) in type 2 diabetic rats and its effects on the nuclear factor-κB (NF-κB) signaling pathway, which is associated with diabetic nephropathy. The type 2 diabetic rat model was established by a high-fat diet plus streptozocin injection and the rats were subsequently treated with two dosages of ISO, respectively. The levels of blood glucose were determined. Urinary osteopontin, kidney injury molecule-1 (KIM-1) and albumin were measured to evaluate the renal function of the rats. Renal NF-κB signaling activity was assessed by measuring the levels of NF-κB p65, phospho-NF-κB p65, inhibitor of NF-κB (IκBα) and phospho-IκBα, and the NF-κB p65 DNA-binding activity. Downstream inflammatory mediators [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, intercellular adhesion molecule-1 (ICAM-1) and transforming growth factor-β1 (TGF-β1)] of the NF-κB signaling pathway were investigated to evaluate the renal inflammatory response. Renal levels of malondialdehyde and total superoxide dismutase were detected to access the oxidative stress. Furthermore, glomerular mesangial cells (GMCs) were treated with lipopolysaccharide and ISO. In the cellular experiment, the NF-κB signaling activity, levels of TNF-α, IL-1β, IL-6, ICAM-1 and TGF-β1, and oxidative stress were also investigated. The results showed that ISO decreased the levels of urinary osteopontin, KIM-1 and albumin. ISO also inhibited the NF-κB signaling activity, decreased the production of inflammatory mediators and attenuated oxidative stress in diabetic rats and GMCs. The present investigations revealed that ISO had ameliorative effects on diabetes-induced renal damage and the activity may be associated with the negative regulation of NF-κB signaling pathway.

Panax notoginseng saponins protect kidney from diabetes by up-regulating silent information regulator 1 and activating antioxidant proteins in rats

OBJECTIVE

To explore the mechanism of the protective effects of Panax notoginseng saponins (PNS) on kidney in diabetic rats.

METHODS

Diabetic rat model was obtained by intravenous injection of alloxan, and the rats were divided into model, PNS-100 mg/(kg day) and PNS-200 mg/(kg day) groups, 10 each. Another 10 rats injected with saline were served as control. Periodic acid-Schiff staining and immunological histological chemistry were used to observe histomorphology and tissue expression of bone morphogenetic protein-7 (BMP-7). Silent information regulator 1 (SIRT1) was silenced in rat mesangial cells by RNA interference. The mRNA expressions of SIRT-1, monocyte chemoattractant protein-1 (MCP-1), transforming growth factor β1 (TGF-β1) and plasminogen activator inhibitor-1 (PAI-1) were analyzed by reverse transcription polymerase chain reaction. The protein expressions of SIRT1 and the acetylation of nuclear factor κB (NF-κB) P65 were determined by western blotting. The concentration of MCP-1, TGF-β1 and malondialdehyde (MDA) in culture supernatant were detected by enzyme-linked immuno sorbent assay. The activity of superoxide dismutase (SOD) was detected by the classical method of nitrogen and blue four.

RESULTS

In diabetic model rats, PNS could not only reduce blood glucose and lipid (P<0.01), but also increase protein level of BMP-7 and inhibit PAI-1 expression for suppressing fibrosis of the kidney. In rat mesangial cells, PNS could up-regulate the expression of SIRT1 (P<0.01) and in turn suppress the transcription of TGF-β1 (P<0.05) and MCP-1 (P<0.05). PNS could also reverse the increased acetylation of NF-κB p65 by high glucose. In addition, redox regulation factor MDA was down-regulated (P<0.05) and SOD was up-regulated (P<0.01), which were both induced by SIRT1 up-regulation.

CONCLUSIONS

PNS could protect kidney from diabetes with the possible mechanism of up-regulating SIRT1, therefore inhibiting inflammation through decreasing the induction of inflammatory cytokines and TGF-β1, as well as activating antioxidant proteins.

Naringin Alleviates Diabetic Kidney Disease through Inhibiting Oxidative Stress and Inflammatory Reaction

Naringin, a flavanone glycoside extracted from Citrus grandis Osbeck, has a wide range of pharmacological effects. In the present study we aimed at demonstrating the protective effect of naringin against diabetic kidney disease (DKD) and elucidating its possible molecular mechanism underlying. The beneficial effect of naringin was assessed in rats with streptozotocin (STZ)-induced diabetes and high glucose-induced HBZY-1 cells. According to our results, first we found that naringin relieved kidney injury, improved renal function and inhibited collagen formation and renal interstitial fibrosis. Second, we confirmed that naringin restrained oxidative stress by activating Nrf2 antioxidant pathway. Moreover, the results suggested that naringin significantly resisted inflammatory reaction by inhibiting NF- κ B signaling pathway. Taken together, our results demonstrate that naringin effectively alleviates DKD, which provide theoretical basis for naringin clinically used to treatment of DKD.

Peptide-based inhibition of IκB kinase/nuclear factor-κB pathway protects against diabetes-associated nephropathy and atherosclerosis in a mouse model of type 1 diabetes

AIMS/HYPOTHESIS

The canonical nuclear factor-κB (NF-κB) pathway mediated by the inhibitor of NF-κB kinase (IKK) regulates the transcription of inflammatory genes involved in the pathogenesis of diabetes, from the early phase to progression and final complications. The NF-κB essential modulator binding domain (NBD) contained in IKKα/β is essential for IKK complex assembly. We therefore investigated the functional consequences of targeting the IKK-dependent NF-κB pathway in the progression of diabetes-associated nephropathy and atherosclerosis.

METHODS

Apolipoprotein E-deficient mice with diabetes induced by streptozotocin were treated with a cell-permeable peptide derived from the IKKα/β NBD region. Kidneys and aorta were analysed for morphology, leucocyte infiltrate, collagen, NF-κB activity and gene expression. In vitro studies were performed in renal and vascular cells.

RESULTS

NBD peptide administration did not affect the metabolic severity of diabetes but resulted in renal protection, as evidenced by dose-dependent decreases in albuminuria, renal lesions (mesangial expansion, leucocyte infiltration and fibrosis), intranuclear NF-κB activity and proinflammatory and pro-fibrotic gene expression. Furthermore, peptide treatment limited atheroma plaque formation in diabetic mice by decreasing the content of lipids, leucocytes and cytokines and increasing plaque stability markers. This nephroprotective and anti-atherosclerotic effect was accompanied by a decline in systemic T helper 1 cytokines. In vitro, NBD peptide prevented IKK assembly/activation, p65 nuclear translocation, NF-κB-regulated gene expression and cell proliferation induced by either high glucose or inflammatory stimulation.

CONCLUSIONS/INTERPRETATION

Peptide-based inhibition of IKK complex formation attenuates NF-κB activation, suppresses inflammation and retards the progression of renal and vascular injury in diabetic mice, thus providing a feasible approach against diabetes inflammatory complications.

Renal Protective Effects of a Diet and Exercise Intervention in Type 2 Diabetic Rats

Purpose:

Diabetic nephropathy (DN) is one of the most common diabetic microvascular complications. Inflammatory factors participate in each stage of DN, and nuclear factor (NF)-κB and monocyte chemoattractant protein-1(MCP-1) play important mediation roles. The purpose of this study was to investigate the renal protective effects of a diet and exercise intervention in a rat model of Type 2 diabetes mellitus (T2DM).

Method:

Control rats (Group A, n = 10) were fed a normal diet, while 30 rats were fed a high-glucose, high-fat diet and given an intraperitoneal injection of streptozocin to establish the T2DM model. Model rats ( n = 8 per group) were randomized into Groups B, C, and D. Groups C and D were treated with glibenclamide, and Group D received an 8-week diet and exercise intervention. Blood, 12-hr urine, and kidney tissue samples were collected postintervention for detecting blood glucose and lipid levels, expression of MCP-1 and NF-κB, and renal function indices.

Results:

Postintervention, blood glucose, and lipid levels in Groups C and D were lower than those in Group B, with decreases in Group D significantly greater than in Group C. Every index of renal protection showed greater improvement in Group D than in Group C ( p < .05). The expression of NF-κB and MCP-1 was lower in Group D than in Group C ( p < .05).

Conclusions:

The diet and exercise intervention reduced the inflammatory reaction and delayed T2DM and DN progression by inhibiting the activation of NF-κB and downregulating the expression of MCP-1.

Altered Mitochondrial Function, Mitochondrial DNA and Reduced Metabolic Flexibility in Patients With Diabetic Nephropathy

The purpose of this study was to determine if mitochondrial dysfunction plays a role in diabetic nephropathy (DN), a kidney disease which affects > 100 million people worldwide and is a leading cause of renal failure despite therapy. A cross-sectional study comparing DN with diabetes patients without kidney disease (DC) and healthy controls (HCs); and renal mesangial cells (HMCs) grown in normal and high glucose, was carried out. Patients with diabetes (DC) had increased circulating mitochondrial DNA (MtDNA), and HMCs increased their MtDNA within 24 h of hyperglycaemia. The increased MtDNA content in DCs and HMCs was not functional as transcription was unaltered/down-regulated, and MtDNA damage was present. MtDNA was increased in DC compared to HC, conversely, patients with DN had lower MtDNA than DC. Hyperglycaemic HMCs had fragmented mitochondria and TLR9 pathway activation, and in diabetic patients, mitophagy was reduced. Despite MtDNA content and integrity changing within 4 days, hyperglycaemic HMCs had a normal bio-energetic profile until 8 days, after which mitochondrial metabolism was progressively impaired. Peripheral blood mononuclear cells (PBMCs) from DN patients had reduced reserve capacity and maximal respiration, loss of metabolic flexibility and reduced Bioenergetic Health Index (BHI) compared to DC. Our data show that MtDNA changes precede bioenergetic dysfunction and that patients with DN have impaired mitochondrial metabolism compared to DC, leading us to propose that systemic mitochondrial dysfunction initiated by glucose induced MtDNA damage may be involved in the development of DN. Longitudinal studies are needed to define a potential cause–effect relationship between changes in MtDNA and bioenergetics in DN.

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Diabetic nephropathy may be a disease of acquired MtDNA damage and bioenergetic deficit.

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MtDNA content is increased in blood cells of diabetes patients and hyperglycaemic renal cells.

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Hyperglycaemia leads to renal cell MtDNA damage and subsequent bioenergetic dysfunction.

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Diabetic nephropathy patients have reduced circulating MtDNA , BHI and metabolic flexibility bioenergetic dysfunction and reduced metabolic flexibility and BHI.

Combination of active components of Xiexin decoction ameliorates renal fibrosis through the inhibition of NF-κB and TGF-β1/Smad pathways in db/db diabetic mice

Xiexin decoction, a herbal therapeutic agent commonly used in traditional Chinese medicine, is recognized for its beneficial effects on diabetic nephropathy exerted through the combined action of multiple components, including Rhizoma Coptidis alkaloids (A), Radix et Rhizoma Rhei polysaccharides (P), and Radix Scutellaria flavones (F). Our previous studies have shown that a combination of A, P, and F (APF) exhibits renoprotective effects against diabetic nephropathy. This study was aimed at determining the effects of APF on renal fibrosis in diabetic nephropathy and elucidating the underlying molecular mechanisms. To evaluate the effects of APF, in vivo, db/db diabetic mice were orally administered a low or high dose of APF (300 or 600 mg/kg, respectively) once a day for 8 weeks. We evaluated the blood and urine indices of metabolic and renal function, renal tissue histopathology, renal inflammation, and fibrosis. APF treatment significantly ameliorated glucose and lipid metabolism dysfunction, decreased urinary albumin excretion, normalized creatinine clearance, and reduced the morphological changes in renal tissue. Additionally, APF administration in db/db diabetic mice reduced the elevated levels of renal inflammation mediators such as intercellular adhesion molecule-1, monocyte chemotactic protein-1, tumor necrosis factor-α, interleukin-1β, and active nuclear factor κB (NF-κB). APF treatment also reduced type I and IV collagen, transforming growth factor-β1 (TGF-β1), and TGF-β1 type II receptor expression levels, and decreased the phosphorylation of Smad2/3 in the kidneys of db/db diabetic mice. These results suggest that APF reduces renal fibrosis in diabetic nephropathy through the NF-κB and TGF-β1/Smad signaling pathways. In vitro, APF treatment reduced cell proliferation and protein expression of α-smooth muscle actin, collagen I, TGF-β1 and NF-κB in mesangial cells cultured with high glucose concentrations. Our findings indicate that treatment with multi-component herbal therapeutic formulations may be a useful approach for the treatment of diabetic nephropathy.