Protective effect of modified Huangqi Chifeng decoction on immunoglobulin A nephropathy through toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway.

OBJECTIVE: To examine the nephroprotective mechanism of modified Huangqi Chifeng decoction (, MHCD) in immunoglobulin A nephropathy (IgAN) rats. METHODS: To establish the IgAN rat model, the bovine serum albumin, lipopolysaccharide, and carbon tetrachloride 4 method was employed. The rats were then randomly assigned to the control, model, telmisartan, and high-, medium-, and low-dose MHCD groups, and were administered the respective treatments via intragastric administration for 8 weeks. The levels of 24-h urinary protein, serum creatinine (CRE), and blood urea nitrogen (BUN) were measured in each group. Pathological alterations were detected. IgA deposition was visualized through the use of immunofluorescence staining. The ultrastructure of the kidney was observed using a transmission electron microscope. The expression levels of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-ß1 (TGF-ß1) were examined by immunohistochemistry and quantitative polymerase chain reaction. Levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor-kappa B (NF-κB) P65, were examined by immunohistochemistry, Western blotting, and quantitative polymerase chain reaction. RESULTS: The 24-h urine protein level in each group increased significantly at week 6, and worsen from then on. But this process can be reversed by treatments of telmisartan, and high-, medium-, and low-dose of MHCD, and these treatments did not affect renal function. Telmisartan, and high-, and medium-dose of MHCD reduced IgA deposition. Renal histopathology demonstrated the protective effect of high-, medium-, and low-dose of MHCD against kidney injury. The expression levels of MCP-1, IL-6, and TGF-ß1 in kidney tissues were downregulated by low, medium and high doses of MHCD treatment. Additionally, treatment of low, medium and high doses of MHCD decreased the protein and mRNA levels of TLR4, MyD88, and NF-κB. CONCLUSIONS: MHCD exerted nephroprotective effects on IgAN rats, and MHCD regulated the expressions of key targets in TLR4/MyD88/NF-κB signaling pathway, thereby alleviating renal inflammation by inhibiting MCP-1, IL-6 expressions, and ameliorating renal fibrosis by inhibiting TGF-ß1 expression.

LPS/TLR4 Pathway Regulates IgA1 Secretion to Induce IgA Nephropathy.

Context: Studies have reported that the incidence and severity of IgA nephropathy (IgAN) are closely related to the imbalance of the intestinal flora. Imbalance of the intestinal flora may cause abnormalities, such as intestinal mucosal immunity or mesenteric B1 lymphocyte subsets. These can lead to an increase in immunoglobulin A (IgA) production and IgA structural changing, which can eventually cause IgA1 deposition in the glomerular mesangial area and nephritis. Objective: The study intended to explore whether the LPS/TLR4 pathway regulates mesenteric B cells, secreting Gd-IgA1 to induce IgA nephropathy. Design: The research team designed an animal study. Setting: The study took place at Department of Nephrology, Minhang Hospital, Fudan University. Animals: The animals were 60 specific pathogen free (SPF) C57BL/6 (B6, H-2b) male mice from that were 6-8 weeks old and weighed 20-25 grams. Intervention: The research team established a mouse model of IgA nephropathy. The team created five groups of mice: (1) the NC group, a normal negative control group without induced nephropathy and with no treatments; (2) the IgA nephropathy (IgAN) group, a positive control group with induced nephropathy and with no treatments; (3) the IgAN+anti-TLR4 group, an intervention group, with induced nephropathy and with a TLR4-antibody (anti-TLR4) treatment; (4) the IgAN+GEC group, an intervention group, with induced nephropathy and with treatment with glutamine enteric-coated capsules (GEC); and (5) the IgAN+anti-TLR4+GEC group, an intervention group, with induced nephropathy and with treatment with anti-TLR4 and GEC. Outcome Measures: The research team collected the blood and urine of all the mice and used an enzyme-linked immunoassay (ELISA) to analyze the levels of blood creatinine, urine protein, and urea nitrogen (BUN). The team also used the ELISA to analyze signal molecules for serum inflammation: interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1), cyclooxygenase-2 (COX2), and galactose-deficient IgA1(Gd-IgA1). The team analyzed the distribution and content of IgA+B220+B lymphocytes in the intestinal tissues of all the mice, using tissue immunofluorescence tracking technology, and used hematoxylin-eosin (HE) staining to analyze the pathological damage in the kidney tissue. For analysis of glomerular IgA deposition, the team used a tissue immunofluorescence technique, and for detection of protein expression-toll-like receptor 4 (TLR4), B-cell activating factor (BAFF), and a proliferation-inducing ligand (APRIL)-in mesenteric lymphoid tissues, the team used western blot analysis. Results: For the five groups of mice, the amount or degree of the physiological indicators and inflammatory factors that ELISA detected, the B lymphocytes and IgA sedimentation that immunofluorescence tracing measured, the kidney pathological that HE staining detected, and the expression of immune-related proteins that western blotting measured, all showed a common trend: IgAN group> IgAN+ glomerular endothelial cells (GEC) group> IgAN+anti-TLR4 group> IgAN+anti-TLR4+GEC group> NC group. Conclusions: The TLR4 antibody and GEC for the treatment of the intestinal tract can regulate and repair intestinal function, so that IgAN can also be relieved at the same time. The results supported the hypothesis that a relationship exists between IgAN and the LPS/TLR4 pathway that regulates mesenteric B cells to secrete low-glycosylated poly-IgA1, which provides a new potential therapeutic plan for IgA nephritis.

[Notoginsenoside R_1 interferes with renal oxidative stress and Nrf2/HO-1 signaling pathway to alleviate kidney injury in mice with IgA nephropathy and its mechanism].

The purpose of this study was to investigate the effect of notoginsenoside R_1(NGR_1) on alleviating kidney injury by regulating renal oxidative stress and the Nrf2/HO-1 signaling pathway in mice with IgA nephropathy(IgAN) and its mechanism. The mouse model of IgAN was established using a variety of techniques, including continuous bovine serum albumin(BSA) gavage, subcutaneous injections of carbon tetrachloride(CCl_4) castor oil, and tail vein injections of lipopolysaccharide(LPS). After successful modeling, mice with IgAN were randomly separated into a model group, low, medium, and high-dose NGR_1 groups, and a losartan group, and C57BL6 mice were utilized as normal controls. The model and normal groups were given phosphate buffered saline(PBS) by gavage, the NGR_1 groups were given varying dosages of NGR_1 by gavage, and the losartan group was given losartan by gavage for 4 weeks. The 24-hour urine of mice was collected after the last administration, and serum and kidney tissues of mice were taken at the end of the animal experiment. Then urine red blood cell count(URBCC), 24-hour urine protein(24 h protein), serum creatinine(Scr), and blood urea nitrogen(BUN) levels were measured. The enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of galactose-deficient IgA1(Gd-IgA1), kidney injury molecule 1(Kim-1), and neutropil gelatinase-associated lipocalin(NGAL) in the mouse serum. The assay kits were used to detect the levels of malondialdehyde(MDA) and superoxide dismutase(SOD), and immunofluorescence(IF) was used to detect the expression level of glutathione peroxidase 4(GPX4) in the mesangial region. Western blot was used to detect the protein expression of nuclear transcription factor E2 related factor 2(Nrf2)/heme oxygenase 1(HO-1) signaling pathway in the renal tissue. Hematoxylin-eosin(HE) staining was used to observe pathological alterations in the glomerulus of mice. The results revealed that, as compared with the model group, the serum Gd-IgA1 level, URBCC, 24 h protein level, renal damage markers(Kim-1 and NGAL) in the high-dose NGR_1 group decreased obviously and renal function indicators(BUN, Scr) improved significantly. The activity of SOD activity and expression level of GPX4 increased significantly in the high-dose NGR_1 group, whereas the expression level of MDA reduced and protein expression levels of Nrf2 and HO-1 increased. Simultaneously, HE staining of the renal tissue indicated that glomerular damage was greatly decreased in the high-dose NGR_1 group. In conclusion, this study has clarified that NGR_1 may alleviate the kidney injury of mice with IgAN by activating the Nrf2/HO-1 signaling pathway, improving antioxidant capacity, and reducing the level of renal oxidative stress.

Efficacy of Modified Huangqi Chifeng decoction in alleviating renal fibrosis in rats with IgA nephropathy by inhibiting the TGF-ß1/Smad3 signaling pathway through exosome regulation.

ETHNOPHARMACOLOGICAL RELEVANCE: IgA nephropathy is the most common form of primary glomerulonephritis and is a major cause of renal failure worldwide. Modified Huangqi Chifeng decoction (MHCD), a traditional Chinese herbal preparation, has clinical efficacy in reducing the 24-h urine protein levels in patients with IgA nephropathy. However, the molecular mechanism of MHCD needs further study. AIM OF THE STUDY: This study aimed to investigate the mechanisms by which MHCD treatment alleviates renal fibrosis. MATERIALS AND METHODS: An IgA nephropathy rat model was established using bovine serum albumin, carbon tetrachloride, and lipopolysaccharide. The rats were divided into control, model, telmisartan, low-dose MHCD, medium-dose MHCD, and high-dose MHCD groups. Treatments were administered to these groups for 8 weeks. Subsequently, the 24-h urine protein, serum creatinine, blood urea nitrogen, and blood albumin levels were measured. Pathological changes and degree of fibrosis in renal tissues were observed, and levels of the transforming growth factor-ß1 (TGF-ß1)/Smad3 signaling pathway components in renal tissues and TGF-ß1 in urinary exosomes were measured. RESULTS: Telmisartan and MHCD reduced 24-h urine protein levels, alleviated renal pathological injury, and decreased the renal expression of fibronectin, laminin, and collagen IV in rats with IgA nephropathy. Urinary exosomes were extracted and identified for further investigation of their role in renal fibrosis. MHCD reduced TGF-ß1 expression in urinary exosomes and reduced TGF-ß1 and p-Smad3 levels in renal tissues. CONCLUSION: MHCD alleviated renal fibrosis in rats with IgA nephropathy by inhibiting the TGF-ß1/Smad3 signaling pathway through the downregulation of TGF-ß1 expression in exosomes.

Huangkui Capsule in Combination with Leflunomide Improves Immunoglobulin A Nephropathy by Inhibiting the TGF-ß1/Smad3 Signaling Pathway.

OBJECTIVES: To investigate the efficacy and potential molecular mechanism of Huangkui capsule in combination with leflunomide (HKL) for the treatment of immunoglobulin A nephropathy (IgAN). METHODS: IgAN rat models were constructed by treating rats with bovine serum albumin, lipopolysaccharide, and tetrachloromethane. Th22 cells were isolated from the blood samples of patients with IgAN using a CD4+ T cell isolation kit. The expression levels of the components of the TGF-ß1/Smad3 signaling pathway, namely, TGF-ß1, Smad2, Smad3, Smad4, and Smad7, were detected using quantitative reverse transcription polymerase chain reaction. Cell proliferation was determined using the MTT assay, cell viability was determined using the WST 1 method, and the chemotaxis of Th22 cells was observed using the wound healing assay. Changes in the histology of the kidney tissues were analyzed using hematoxylin and eosin staining. RESULTS: Compared with IgAN rats, the rats subjected to HKL treatment showed good improvement in kidney injuries, and the combined drug treatment performed much better than the single-drug treatment. In addition, following HKL treatment, the viability, proliferation, and chemotaxis of Th22 cells dramatically decreased (*p<0.05, **p<0.01, and ***p<0.001). In addition, CCL20, CCL22, and CCL27 levels decreased and the expression of the key components of the TGF-ß1/Smad3 signaling pathway was downregulated in IgAN rats and Th22 cells (*p<0.05, ***p<0.001). CONCLUSIONS: By targeting the TGF-ß1/Smad3 signaling pathway, HKL treatment can improve kidney injury in IgAN rats as well as the excessive proliferation and metastasis of Th22 cells.

Huangqi Guizhi Wuwu Decoction attenuates Podocyte cytoskeletal protein damage in IgA nephropathy rats by regulating AT1R/Nephrin/c-Abl pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Huangqi Guizhi Wuwu Decoction(HQGZWWD) is a Traditional Chinese Medicine formula from Synopsis of Golden Chamber used to treat blood arthralgia. According to the principle that the same treatment can be used for different diseases, HQGZWWD has proven effective for IgA nephropathy (IgAN) associated with spleen and kidney yang deficiency. AIM OF THE STUDY: In this study, we investigated the mechanism by which HQGZWWD alleviates proteinuria and protects renal function in rats with IgAN by regulating the AT1R/Nephrin/c-Abl pathway. METHODS: Rats were randomly divided into six groups: control, IgAN model, IgAN model treated with low-dose HQGZWWD, IgAN model treated with medium-dose HQGZWWD, IgAN model treated with high-dose HQGZWWD, and IgAN model treated with valsartan. IgAN was induced using bovine γ-globulin. We evaluated the mediating effects of HQGZWWD on podocyte cytoskeletal proteins, the AT1R/Nephrin/c-Abl pathway, upstream tumor necrosis factor-α (TNF-α), and TNF-α receptor-1 (TNFR1). RESULTS: The IgAN rats displayed proteinuria, IgA deposition in the mesangial region, and podocyte cytoskeletal protein damage. The expression of TNF-α, TNFR1, AT1R, and c-Abl was increased in the IgAN rat kidney, whereas the expression of nephrin, podocin, ACTN4, and phosphorylated nephrin (p-nephrin) was reduced. HQGZWWD treatment significantly alleviated podocyte cytoskeletal protein damage in the IgAN rats, upregulated the expression of nephrin, podocin, and ACTN4, and the colocalized expression of F-actin and nephrin. This study demonstrates that HQGZWWD attenuates podocyte cytoskeletal protein damage by regulating the AT1R-nephrin- c-Abl pathway, upregulating the expression of p-nephrin, and downregulating the expression of AT1R and c-Abl. CONCLUSIONS: These results indicate that HQGZWWD attenuates podocyte cytoskeletal protein damage in IgAN rats by regulating the AT1R/Nephrin/c-Abl pathway, providing a potential therapeutic approach for IgAN.

Huangkui capsule in combination with leflunomide improves immunoglobulin a nephropathy by inhibiting the TGF-ß1/Smad3 signaling pathway.

OBJECTIVES: To investigate the efficacy and potential molecular mechanism of Huangkui capsule in combination with leflunomide (HKL) for the treatment of immunoglobulin A nephropathy (IgAN) METHODS: IgAN rat models were constructed by treating rats with bovine serum albumin, lipopolysaccharide, and tetrachloromethane. Th22 cells were isolated from the blood samples of patients with IgAN using a CD4+ T cell isolation kit. The expression levels of the components of the TGF-β1/Smad3 signaling pathway, namely, TGF-β1, Smad2, Smad3, Smad4, and Smad7, were detected using quantitative reverse transcription polymerase chain reaction. Cell proliferation was determined using the MTT assay, cell viability was determined using the WST 1 method, and the chemotaxis of Th22 cells was observed using the wound healing assay. Changes in the histology of the kidney tissues were analyzed using hematoxylin and eosin staining. RESULTS: Compared with IgAN rats, the rats subjected to HKL treatment showed good improvement in kidney injuries, and the combined drug treatment performed much better than the single-drug treatment. In addition, following HKL treatment, the viability, proliferation, and chemotaxis of Th22 cells dramatically decreased (*p<0.05, **p<0.01, and ***p<0.001). In addition, CCL20, CCL22, and CCL27 levels decreased and the expression of the key components of the TGF-β1/Smad3 signaling pathway was downregulated in IgAN rats and Th22 cells (*p<0.05, ***p<0.001). CONCLUSIONS: By targeting the TGF-β1/Smad3 signaling pathway, HKL treatment can improve kidney injury in IgAN rats as well as the excessive proliferation and metastasis of Th22 cells.

Jixuecao (Herba Centellae Asiaticae) alleviates mesangial cell proliferation in IgA nephropathy by inducing mitofusin 2 expression.

OBJECTIVE: To investigate the effect of mitofusin 2 (Mfn2) and its downstream signaling pathway on glomerular mesangial cells (GMCs) proliferation in IgA nephropathy (IgAN), as well as the mechanism of action of Jixuecao (Herba Centellae Asiaticae, HCA) in the treatment of IgAN. METHODS: Adenovirus-mediated Mfn2 gene transfection and Mfn2 expression were analyzed by real-time polymerase chain reaction (PCR) and Western blotting. IgA1 induced the proliferation of GMCs, which were then treated with HCA. Cell proliferation was detected with cell counting kit-8 (CCK-8), and Mfn2 expression was analyzed by real-time PCR and western blotting. An IgAN animal model was also established and treated with HCA. GMCs proliferation was detected by hematoxylin-eosin staining, mitochondrial structure was analyzed by electron microscopy, mitochondrial function was determined by the Clark oxygen electrode method, and the expression of Mfn2, Phospho-extracellular regulated protein kinases1/2 (P-ERK1/2), Cyclin-dependent kinase 2 (CDK2), Phospho-p27 (p-p27), and cyclin A was analyzed by Western blotting. RESULTS: In vitro, HCA inhibited GMCs in a concentration-dependent manner in association with the upregulation of Mfn2 expression. The overexpression of Mfn2 inhibited IgA1-induced GMCs proliferation and elevated the effect of HCA. In vivo, treatment with HCA could alleviate albuminuria and creatinine and GMCs proliferation. These effects were related to the upregulation of Mfn2, p-p27 and inhibition of p-ERK1/2, CDK2, and cyclinA. Mitochondrial swelling, vacuolar degeneration, and reduction of respiratory control rate were identified in IgAN, but HCA could improve the mitochondrial structure and function. CONCLUSION: HCA inhibited GMCs proliferation via the upregulation Mfn2 and the inhibition of Ras-Raf-ERK/MAPK. We revealed that changes of mitochondrial structure and function are associated with IgAN, but that HCA can improve these mitochondrial features.

Effectiveness of Qingre Lishi Yishen decoction on the glomerular fibrosis of immunoglobulin A nephropathy in a rat's model.

OBJECTIVE: To investigate the effect of the clinical effective prescription of Qingre Lishi Yishen decoction (QRLS) on the activation of mesangial cells in immunoglobulin A nephropathy (IgAN) rats. METHODS: IgAN rat's model was established by combine with intragastric administration of bovine serum albumin (BSA) + intravenous injection of lipopolysaccharide (LPS) by + subcutaneous injection of carbon tetrachloride (CCL4). Then the animals were randomly divided into four groups: control group, IgAN model group, IgAN model with Valsartan (Val) treatment group and IgAN model with QRLS treatment group. To observe the indexes of 24-h urine protein, renal function, deposition of immune complexes, expression of activation factor, fibrosis marker and inflammatory cytokines in four different groups. RESULTS: The Val or QRLS treatment group: (a) it reduced the immune complexes deposition of IgA in glomerular mesangial and inhibited mesangial cell proliferation; (b) it decreased the expression of smooth muscle actin (α-SMA), fibronectin (FN) and tumor necrosis factor alpha (TNF-α). CONCLUSION: The study suggested that QRLS ameliorate renal structure and function in IgAN rat's model. Furthermore, we also observed that QRLS alleviated mesangial cells activation and matrix accumulation partly by decreasing the α-SMA, then to downregu.

Effects of Periostracum Cicadae on Cytokines and Apoptosis Regulatory Proteins in an IgA Nephropathy Rat Model.

Periostracum cicadae, the cast-off shell of the cicada Cryptotympana pustulata Fabricius, is used in traditional Chinese medicine for its diaphoretic, anticonvulsive, sedative, antipyretic, and antiallergic effects. However, the exact pathogenesis of immunoglobulin A nephropathy (IgAN) remains unclear, thereby hindering investigations to identify novel therapeutic agents. A rat IgAN model was established by administration of bovine serum albumin, lipopolysaccharide, and carbon tetrachloride, which simultaneously established blood stasis and a heat syndrome model. The animals were sacrificed to detect changes in protein levels in urine and blood. Immunofluorescence was performed to assess IgA deposition in the glomeruli. Tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin 6 (IL-6) levels were measured in bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay. Hematology and eosin, periodic acid-Schiff, TUNEL (TdT-mediated dUTP Nick-End Labeling), and immunohistochemical staining were performed to evaluate histopathological changes in kidney tissues. Additionally, target-related proteins were measured by Western blotting. Periostracum cicadae resulted in a reduction in blood and urine protein levels. Serum TNF-α, IL-1ß, and IL-6 levels significantly decreased in the periostracum cicadae-treated groups compared to the IgAN group. Furthermore, a reduction in MCP-1 (Monocyte Chemotactic Protein-1), TLR4 ((Toll-Like Receptor 4)), and IgA expression levels and a dose-dependent increase in caspase 3 expression were observed in response to periostracum cicadae treatment. TGF-ß1(Transforming Growth Factor-ß) levels decreased, whereas that of Fas increased in the kidney tissues of the periostracum cicadae-treated groups. The findings of the present study indicate that periostracum cicadae induces apoptosis and improves kidney inflammation and fibrosis in IgA nephropathy rat models.

Zhen-wu-tang protects against podocyte injury in rats with IgA nephropathy via PPARγ/NF-κB pathway.

Zhen-wu-tang (ZWT) has been widely applied in chronic kidney diseases. However, the mechanism of ZWT remains unclear. Peroxisome proliferator-activated receptors-γ (PPARγ) is known as a protective factor for podocyte and kidney function. This study is aimed to investigate the protective effects of ZWT on IgA nephropathy (IgAN) in rats against podocyte injury and the underlying mechanism related to PPARγ. IgAN model rats were induced by administering bovine serum albumin, lipopolysaccharide, and carbon tetrachloride. ZWT at two doses and GW9662 (PPARγ antagonist) was administered once daily for 4 weeks respectively. Cultured podocyte induced by LPS were used to evaluate the podocyte-protective effect and related mechanism of ZWT in vitro. Results showed that ZWT observably reduced proteinuria and hematuria excretion, as well as the levels of blood urea nitrogen, serum creatinine, serum uric acid, low-density lipoprotein cholesterol, total cholesterol and triglycerides, but increased the contents of high-density lipoprotein cholesterol, ameliorating renal function and hyperlipidemia state in IgAN rats. Besides, both ZWT administration groups alleviated kidney pathological lesion, macrophage infiltration, IgA and C3 deposition in glomeruli. To further demonstrate the protective effects of ZWT, we found that podocyte damage was markedly ameliorated with ZWT treatments in IgAN rats and LPS-induced podocyte injury model by suppressing the expressions of desmin, reducing podocyte apoptosis and augmenting nephrin and podocin levels. Moreover, ZWT inhibited the phosphorylation of NF-κB and IκBα, simultaneously upregulated PPARγ. However, GW9662 made no difference in all the above effects compared to the model group, and was reversed by ZWT in vitro study. In conclusion, these results demonstrated that ZWT ameliorated IgAN-induced podocyte injury via upregulation PPARγ and the underlying mechanism might involve the inhibition of NF-κB pathway.

[Effects of Gubentongluo Formula on Oxidative Stress Reflected by Expressions of PPARα and L-FABP in Mice with IgA Nephropathy].

OBJECTIVES: To determine the underlying mechanism of Gubentongluo Formula in the treatment of IgA nephropathy (IgAN). METHODS: C57BL/6 mice were randomly divided into four groups: normal group (n =10), IgAN group (n =10), control group (n =10) and treatment group (n =10). Mice in the normal and IgAN groups were intragastricly administered with normal saline for 12 weeks; while those in the control and treatment groups were given fenofibrate [30 mg/(kg!$d) and Gubentongluo Formula [1.67 mL/(g!$d)], respectively. Urinary albumin was detected at week 0 and 12. At week 12, protein expressions of peroxisome proliferstor activated receptor α (PPARα), liver fatty acid-binding proteins (L-FABP), 4-hydroxy-2-nonenal (4-HNE), and hemeoxygenase-1(HO-1) in renal tissues were determined by Western blot; mRNA expressions of PPARα and L-FABP in renal tissues were determined by florescent quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: At week 12, higher levels of urinary albumin, pathological injuries in glomerular mesangial area, and lower expressions of protein and mRNA of PPARα and L-FABP were found in mice in the IgAN group compared with those in the normal group (P <0.01). The levels of those indicators decreased in those treated with fenofibrate and Gubentongluo Formule, but still higher than the normal controls (P <0.01). The mice treated with Gubentongluo Formula had more significant improvement than those treated with fenofibrate (P <0.05). CONCLUSION: [CM(155.3mm]Gubentongluo formula can improve proteinuria and pathological injuries in glomerular mesangial area of IgAN mice, due to reduction of oxidative stress in renal tissues through regulating the expressions of PPARα and L-FABP.

A system biology approach to understanding the molecular mechanisms of Gubentongluo decoction acting on IgA Nephropathy.

BACKGROUND: Traditional Chinese medicine (TCM) has been widely used in treating various diseases in eastern Asia for several thousand years, and is becoming increasingly popular in western countries. Gubentongluo (GBTL) decoction, as a classic TCM formula, is commonly applied to treat IgA Nephropathy (IgAN) in China. To date, however, the pharmacological/molecular mechanisms of GBTL have not been fully elucidated. METHOD: In the present study, we used a system biological approach to explore these mechanisms acting on IgAN. RESULTS: First, we found 3876 potential target proteins for GBTL (based on TCMID) and 25 known IgAN associated biomarkers (based on the OMIM or IPA database).16 of the latter biomarkers were direct targets of 6 of the 9 herbs in GBTL, suggesting that these components play a vital role in treating IgAN. Second, we showed that these 6 herbs mainly regulate the immune system and renin-angiotensin system, imbalance in which is the main factor leading to IgAN. Importantly, HUANG QI links with 14 biomarkers, indicating that it is the most important herb in GBTL for treating IgAN. Also, relationships of other herbs with IgAN were explored. Third, we demonstrated that the remaining 9 IgAN associated proteins are responses to biological processes, such as antigen processing, protein ubiquitination and cell cycle regulation, which are crucial for IgAN development. Finally, we found that GBTL could induce a significant increase in the levels of two target gene: TNF and NOS2. CONCLUSIONS: Further studies are called to develop/modify the formula of GBTL, in order to enhance its effect on IgAN.

Nephrokeli, a Chinese herbal formula, may improve IgA nephropathy through regulation of the sphingosine-1-phosphate pathway.

Nephrokeli (NPKL) is a Chinese herbal formula that has been used to treat patients with IgA nephropathy (IgAN) for improvement of proteinuria and kidney injury. However, the mechanism remains unclear. Sphingosine-1-phosphate (S1P) and its receptors S1PR2 and S1PR3 are known to play an important role in kidney disease. Here, we tested whether NPKL is able to regulate the S1P pathway in the kidney of IgAN rats. Four groups of rats were included in the study: Control, IgAN, IgAN treated with losartan, and IgAN treated with NPKL. The IgAN model was generated by injection of bovine serum albumin and staphylococcus enterotoxin B. We found that IgAN rats had increased staining for proliferating cell nuclear antigen (PCNA) in the mesangial area and increased mRNA and protein levels of S1PR2 and S1PR3 in the kidney compared to control rats. Connective tissue growth factor (CTGF), a downstream growth factor in the S1P pathway, was also elevated in the kidney of IgAN rats. Treatment with either NPKL or losartan was able to reduce PCNA staining and the expression of both S1PR2 and S1PR3 in the kidney of IgAN rats. However, NPKL (but not losartan treatment) reduced the expression of CTGF in the kidney of IgAN rats. In addition, we treated rat mesangial cells with sera collected from either NPKL-treated rats or control rats and found that NPKL-serum was able to reduce S1P-induced mesangial cell proliferation and the expression of S1PR2/S1PR3 and CTGF. NPKL also attenuates expression of fibrosis, inflammation, and oxidative stress markers in the kidney of IgAN rats. Our studies provide the mechanism by which NPKL attenuates kidney injury in IgAN rats.

The molecular phenotype of endocapillary proliferation: novel therapeutic targets for IgA nephropathy.

IgA nephropathy (IgAN) is a clinically and pathologically heterogeneous disease. Endocapillary proliferation is associated with higher risk of progressive disease, and clinical studies suggest that corticosteroids mitigate this risk. However, corticosteroids are associated with protean cellular effects and significant toxicity. Furthermore the precise mechanism by which they modulate kidney injury in IgAN is not well delineated. To better understand molecular pathways involved in the development of endocapillary proliferation and to identify novel specific therapeutic targets, we evaluated the glomerular transcriptome of microdissected kidney biopsies from 22 patients with IgAN. Endocapillary proliferation was defined according to the Oxford scoring system independently by 3 nephropathologists. We analyzed mRNA expression using microarrays and identified transcripts differentially expressed in patients with endocapillary proliferation compared to IgAN without endocapillary lesions. Next, we employed both transcription factor analysis and in silico drug screening and confirmed that the endocapillary proliferation transcriptome is significantly enriched with pathways that can be impacted by corticosteroids. With this approach we also identified novel therapeutic targets and bioactive small molecules that may be considered for therapeutic trials for the treatment of IgAN, including resveratrol and hydroquinine. In summary, we have defined the distinct molecular profile of a pathologic phenotype associated with progressive renal insufficiency in IgAN. Exploration of the pathways associated with endocapillary proliferation confirms a molecular basis for the clinical effectiveness of corticosteroids in this subgroup of IgAN, and elucidates new therapeutic strategies for IgAN.

Dietary zinc is a key environmental modifier in the progression of IgA nephropathy.

IgA nephropathy (IgAN) shows diverse epidemiological characteristics, resulting from both genetic and acquired (e.g., environmental) causes. Environmental factors, such as diet or exposure to exogenous antigens, may prescribe the progression or prognosis of IgAN. It remains unclear as to how diet and infection influence susceptibility to IgAN. A relationship, such as Toll-like receptors (TLRs), especially TLR9 and TLR4, was demonstrated between IgAN and pathogen-recognition molecules. Recently, zinc (Zn) was discovered to be involved in various immune-related diseases, affecting B, T, and dendritic cells (DCs). This study investigates the relationship between dietary Zn and IgAN development in IgAN-prone mice. Seven-week-old IgAN-prone mice were divided into low, normal, and high Zn diet groups. To assess exogenous pathogen-mediated immune responses, lipopolysaccharide (LPS) was nasally administered. The activity of IgAN was biochemically and pathologically evaluated during the disease course. We also examined in vitro IgA production in spleen cells or in combinations of cocultured B, T, and DCs under various Zn conditions with or without LPS. Dietary conditioning with Zn affected serum immunoglobulins and urinary albumin levels, and mesangial deposition of IgA and IgG. Zn deficiency is associated with IgAN progression through the activation of the TLR4/TIR-domain-containing adapter-inducing interferon-ß (TRIF), but not the TLR9, in DCs. Zn supplementation prevented disease aggravation. Our findings indicate that immune conditioning with dietary Zn alters nephritogenic IgA production after mucosal infection.

Osthole mitigates progressive IgA nephropathy by inhibiting reactive oxygen species generation and NF-κB/NLRP3 pathway.

Renal reactive oxygen species (ROS) and mononuclear leukocyte infiltration are involved in the progressive stage (exacerbation) of IgA nephropathy (IgAN), which is characterized by glomerular proliferation and renal inflammation. The identification of the mechanism responsible for this critical stage of IgAN and the development of a therapeutic strategy remain a challenge. Osthole is a pure compound isolated from Cnidiummonnieri (L.) Cusson seeds, which are used as a traditional Chinese medicine, and is anti-inflammatory, anti-apoptotic, and anti-fibrotic both in vitro and in vivo. Recently, we showed that osthole acts as an anti-inflammatory agent by reducing nuclear factor-kappa B (NF-κB) activation in and ROS release by activated macrophages. In this study, we examined whether osthole could prevent the progression of IgAN using a progressive IgAN (Prg-IgAN) model in mice. Our results showed that osthole administration resulted in prevention of albuminuria, improved renal function, and blocking of renal progressive lesions, including glomerular proliferation, glomerular sclerosis, and periglomerular mononuclear leukocyte infiltration. These findings were associated with (1) reduced renal superoxide anion levels and increased Nrf2 nuclear translocation, (2) inhibited renal activation of NF-κB and the NLRP3 inflammasome, (3) decreased renal MCP-1 expression and mononuclear leukocyte infiltration, (4) inhibited ROS production and NLRP3 inflammasome activation in cultured, activated macrophages, and (5) inhibited ROS production and MCP-1 protein levels in cultured, activated mesangial cells. The results suggest that osthole exerts its reno-protective effects on the progression of IgAN by inhibiting ROS production and activation of NF-κB and the NLRP3 inflammasome in the kidney. Our data also confirm that ROS generation and activation of NF-κB and the NLRP3 inflammasome are crucial mechanistic events involved in the progression of the renal disorder.

n-3 polyunsaturated fatty acids and autoimmune-mediated glomerulonephritis.

Consumption of n-3 polyunsaturated fatty acids (PUFAs) found in fish oil suppresses inflammatory processes making these fatty acids attractive candidates for both the prevention and amelioration of several organ-specific and systemic autoimmune diseases. Both pre-clinical and clinical studies have been conducted to determine whether fish oils containing the n-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) can be used in the prevention and treatment of immunoglobulin A nephropathy (IgAN) and lupus nephritis. In a toxin-induced mouse model that mimics the early stages of IgAN, n-3 PUFA consumption suppresses aberrant interleukin (IL)-6-driven IgA production and mesangial IgA immune complex deposition by impairing phosphorylation of upstream kinases and activation of transcription factors essential for IL-6 gene transcription. n-3 PUFAs can also suppress production of anti-double-stranded DNA IgG antibodies and the resultant development of lupus nephritis in the NZBW F1 mouse and related models. These effects have been linked in part to impaired expression of proinflammatory cytokines and adhesion molecules as well as increases in antioxidant enzymes in kidney and immune organs. Several recent clinical trials have provided compelling evidence that n-3 PUFA supplementation could be useful in treatment of human IgAN and lupus nephritis, although some other studies suggest such supplementation might be without benefit. Future investigations employing genomics/proteomics and novel genetically altered mice should provide further insight into how n-3 PUFAs modulate these diseases as well help to identify clinically relevant biomarkers. The latter could be employed in future well-designed, long-term clinical studies that will resolve current controversies on n-3 PUFA efficacy in autoimmune-mediated glomerulonephritis.

Saireito probably prevents mesangial cell proliferation in HIGA mice via PDGF-BB tyrosine kinase inhibition.

BACKGROUND: In this study, we administered saireito to high serum IgA (HIGA) mice and investigated its inhibitory effect on platelet-derived growth factor (PDGF) receptor tyrosine kinase (which causes mesangial proliferation) as one of the possible antinephritic mechanisms of saireito. METHODS: Female HIGA/NscSlc mice, aged 10 weeks, were divided into five groups (each, n = 12; a control group, three saireito-mixed feed groups, and a captopril-mixed feed group) so that the plasma IgA levels were comparable among the groups. After the grouping, the animals were administered the saireito or captopril, mixed in the feed, until the age of 45 weeks. RESULTS: At the age of 45 weeks, the glomerular cell number was 47.8 +/- 3.9 / cross section in the HIGA mice in the control group, but 41.6 +/- 2.3 / cross section in the 1.3% saireito-mixed feed group and 38.7 +/- 3.5 / cross section in the captopril-mixed feed group, being significantly lower in both these treatment groups than in the control group. At the age of 45 weeks, the sclerosis score in the HIGA mice in the control group was 0.92 +/- 0.23. However, the sclerosis scores in the 0.26% (0.59 +/- 0.26) and 1.3% (0.58 +/- 0.16) saireito-mixed feed groups were significantly lower than that in the control group. In the captopril-mixed feed group, the sclerosis score was 0.64 +/- 0.34, significantly lower than that in the control group. It was clarified that saireito suppressed mesangial cell proliferation without showing any cytotoxicity. Furthermore, as a result of investigating the mesangial cell proliferation-suppressing effect similarly with the 23 substances constituting saireito, a proliferation-suppressing effect was recognized with isoliquiritigenin (a component of Glycyrrhizae Radix) and oroxylin A (a component of Scutellariae Radix). Oroxylin A and isoliquiritigenin showed an inhibitory effect on PDGF receptor tyrosine kinase. Furthermore, the inhibitory effects of oroxylin A and isoliquiritigenin on tyrosine kinase were found to be specific to the PDGF receptor, and showed no influence on the tyrosine kinase activities of other growth-factor receptors examined. CONCLUSION: These results suggest that the antinephritic effects of saireito in HIGA mice may be partly due to the inhibiton of PDGF tyrosine kinase by oroxylin A and isoliquiritigenin, components of saireito.