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Summary Observational studies on dietary or circulating magnesium and risk of cardiovascular disease (CVD) in Chronic Kidney Disease (CKD) stage 1–4 have reported no-to-modest inverse associations. 24 h Urinary magnesium concentration (24 h UMg), an indicator of intestinal magnesium absorption, may provide better insight into the connection of CKD progression. We examined 3179 participants aged 18–74 years with CKD stage 1–4 in the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE) study, a prospective population-based cohort study. Data were analysed using Spearman rank-order correlation coefficients for all comparisons. We also performed a time-to-event analysis of the data using the Kaplan–Meier survival model, Cox proportional hazard model and competing risk Fine and Gray subdistribution hazard model. During a median follow-up of 4.19 years (interquartile range, 3.43–5.09 years), when modelling end-stage renal disease (ESRD), CVD and death, 24 h UMg was associated with risk of CVD (HR, 1.612 (95% CI, 1.056–2.460)), while no significant association with ESRD and death endpoints could be detected. 24 h UMg risk variants display a modest association with CVD in CKD stage 1–4 patients. Trial registration ClinicalTrials.gov Identifier NCT03041987. Registered January 1, 2012. (retrospectively registered) ( https://www.clinicaltrials.gov/ct2/show/NCT03041987?term=Chinese+Cohort+Study+of+Chronic+Kidney+Disease+%28C-STRIDE%29&rank=1 ).

Fluorofenidone (AKF-PD) is a novel pyridone agent that reduces the deposition of extracellular matrix (ECM) in various models of renal fibrosis. However, there are no reports on the effect of AKF-PD in preventing fibrosis in the folic acid nephropathy model. Besides, the mechanisms of action of AKF-PD in preventing renal fibrosis are not fully understood. In the study, we observed that AKF-PD reduced folate-induced kidney injury, ameliorated the deterioration of renal function, and suppressed the deposition of ECM by decreasing the expression of collagen I, collagen III, transforming growth factor-β (TGF-β), fibronectin (FN), and alpha smooth muscle actin (α-SMA) in the folic acid nephropathy model. Additionally, AKF-PD suppressed the activation of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome to reduce the production of caspase-1 and IL-1β, and alleviated mitochondrial oxidative damage by promoting mitochondrial energy metabolism and reducing the expression of NADPH oxidase 4 (NOX4). The results of in vitro experiments demonstrated that AKF-PD suppressed NLRP3 inflammasome activation in activated peritoneal-derived macrophages (PDMs) and renal tubular epithelial cells (RTECs). AKF-PD increased the intracellular ATP content and decreased the expression of NOX4, while preventing the excessive production of mitochondrial reactive oxygen species (mtROS) in activated PDMs. In conclusion, this study demonstrated that AKF-PD inhibited renal fibrosis by suppressing the mtROS-NLRP3 pathway in the folic acid nephropathy model. These findings provide new evidence in support of the clinical use of AKF-PD in the treatment of diseases related to renal fibrosis.

Cholestasis is characterized by intrahepatic accumulation of bile acids (BAs), resulting in liver injury, fibrosis, and liver failure. To date, only ursodeoxycholic acid and obeticholic acid have been approved for the treatment of cholestasis. As fluorofenidone (AKF-PD) was previously reported to play significant anti-fibrotic and anti-inflammatory roles in various diseases, we investigated whether AKF-PD ameliorates cholestasis. A mouse model of cholestasis was constructed by administering a 0.1 % 3,5-diethoxycarbonyl-1,4-dihydroxychollidine (DDC) diet for 14 days. Male C57BL/6 J mice were treated with either AKF-PD or pirfenidone (PD) orally in addition to the DDC diet. Serum and liver tissues were subsequently collected and analyzed. We found that AKF-PD significantly reduced the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bile salts (TBA), as well as hepatic bile acids (BAs) levels. Hepatic histological analyses demonstrated that AKF-PD markedly attenuated hepatic inflammation and fibrosis. Further mechanistic analyses revealed that AKF-PD markedly inhibited expression of Cyp7a1, an enzyme key to BAs synthesis, by increasing Fxr nuclear translocation, and decreased hepatic inflammation by attenuating Erk/-Egr-1-mediated expression of inflammatory cytokines and chemokines Tnfα, Il-1β, Il-6, Ccl2, Ccl5 and Cxcl10. Moreover, AKF-PD was found to substantially reduce liver fibrosis via inhibition of Tgfβ1/Smad pathway in our mouse model. Here, we found that AKF-PD effectively attenuates cholestasis and hepatic fibrosis in the mouse model of DDC-induced cholestasis. As such, AKF-PD warrants further investigation as a candidate drug for treatment of cholestasis.

Cisplatin (CP) is one of the most effective chemotherapeutics in the treatment of human cancers. However, the beneficial effects of CP are limited by the toxic effects, especially nephrotoxicity. Fluorofenidone (AKFPD) is a promising multifunctional antifibrosis pyridinone drug discovered by our group. But there is no evidence of its protective effects against acute kidney injury (AKI). Therefore, we investigated the protective effects of AKFPD on CP-induced AKI

Sterile inflammation is initiated by damage-associated molecular patterns (DAMPs) and a key contributor to acute liver injury (ALI). However, the current knowledge on those DAMPs that activate hepatic inflammation under ALI remains incomplete. We report here that circulating peroxiredoxin-1 (Prdx1) is a novel DAMP for ALI. Intraperitoneal injection of acetaminophen (APAP) elicited a progressive course of ALI in mice, which was developed from 12 to 24 h post injection along with liver inflammation evident by macrophage infiltration and upregulations of cytokines (IL-1β, IL-6 and TNF-α); these alterations were concurrently occurred with a robust and progressive production of serum Prdx1. Similar observations were also obtained in carbon tetrachloride (CCl4)-induced ALI in mice. Removal of the source of serum Prdx1 protected mice deficient in Prdx1 from APAP and CCl4-induced liver injury, and decreased macrophage infiltration, IL-1β, IL-6 and TNF-α production. As a result, Prdx1−/− mice were strongly protected from APAP-induced death that was likely progressed from ALI. Additionally, intravenous re-introduction of recombinant Prdx1 (rPrdx1) in Prdx1−/− mice reversed or reduced all the above events, demonstrating an important contribution of circulating Prdx1 to ALI. rPrdx1 potently induced in primary macrophages the expression of pro-IL-1β, IL-6, TNF-α, and IL-1β through the NF-κB signaling as well as the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling, evident by caspase-1 activation. Furthermore, a significant elevation of serum Prdx1 was demonstrated in patients (n = 15) with ALI; the elevation is associated with ALI severity. Collectively, we provide the first demonstration for serum Prdx1 contributing to ALI.

Background Chronic kidney disease (CKD) leads to end-stage renal failure and cardiovascular events. An attribute to these progressions is abnormalities in inflammation, which can be evaluated using the neutrophil-to-lymphocyte ratio (NLR). We aimed to investigate the association of NLR with the progression of end stage of renal disease (ESRD), cardiovascular disease (CVD) and all-cause mortality in Chinese patients with stages 1–4 CKD. Methods Patients with stages 1–4 CKD (18–74 years of age) were recruited at 39 centers in 28 cities across 22 provinces in China since 2011. A total of 938 patients with complete NLR and other relevant clinical variables were included in the current analysis. Cox regression analysis was used to estimate the association between NLR and the outcomes including ESRD, CVD events or all-cause mortality. Results Baseline NLR was related to age, hypertension, serum triglycerides, total serum cholesterol, CVD history, urine albumin to creatinine ratio (ACR), chronic kidney disease-mineral and bone disorder (CKD-MBD), hyperlipidemia rate, diabetes, and estimated glomerular filtration rate (eGFR). The study duration was 4.55 years (IQR 3.52–5.28). Cox regression analysis revealed an association of NLR and the risk of ESRD only in patients with stage 4 CKD. We did not observe any significant associations between abnormal NLR and the risk of either CVD or all-cause mortality in CKD patients in general and CKD patients grouped according to the disease stages in particular. Conclusion Our results suggest that NLR is associated with the risk of ESRD in Chinese patients with stage 4 CKD. NLR can be used in risk assessment for ESRD among patients with advanced CKD; this application is appealing considering NLR being a routine test. Trial registration ClinicalTrials.gov Identifier NCT03041987. Registered January 1, 2012. (retrospectively registered) (https://www.clinicaltrials.gov/ct2/show/NCT03041987?term=Chinese+Cohort+Study+of+Chronic+Kidney+Disease+%28C-STRIDE%29&rank=1)

Background/Aims: Cyclosporine A (CsA) is an immunosuppressant drug that is used during organ transplants. However, its utility is limited by its nephrotoxic potential. This study aimed to investigate whether fluorofenidone (AKF-PD) could provide protection against CsA-induced nephrotoxicity. Methods: Eighty-five male Sprague-Dawley rats were divided into 5 groups: drug solvent, CsA, CsA with AKF-PD (250, 500 mg/kg/day), and CsA with pirfenidone (PFD, 250 mg/kg/day). Tubulointerstitial injury index, extracellular matrix (ECM) deposition, expression of type I and IV collagen, transforming growth factor (TGF)-β1, platelet-derived growth factor (PDGF), Fas ligand (FASL), cleaved-caspase-3, cleaved-poly(ADP-ribose) polymerase (PARP)-1, and the number of transferase-mediated nick end-labeling (TUNEL)-positive renal tubule cells were determined. In addition, levels of TGF-β1, FASL, cleaved-caspase-3, cleaved-PARP-1, and number of annexin V-positive cells were determined in rat proximal tubular epithelial cells (NRK-52E) treated with CsA (20 μmol/L), AKF-PD (400 μg/mL), PFD (400 μg/mL), and GW788388 (5 μmol/L). Results: AKF-PD (250, 500 mg/kg/day) significantly reduced tubulointerstitial injury, ECM deposition, expression of type I and IV collagen, TGF-β1, PDGF, FASL, cleaved-caspase-3, cleaved-PARP-1, and number of TUNEL-positive renal tubule cells in the CsA-treated kidneys. In addition, AKF-PD (400 μg/mL) significantly decreased TGF-β1, FASL, cleaved-caspase-3, and PARP-1 expression in NRK-52E cells and further reduced the number of annexin V-positive cells. Conclusion: AKF-PD protect kidney from fibrosis and apoptosis in CsA-induced kidney injury.

Despite the increasing understanding of the pathophysiology of hepatic fibrosis, the therapies to combat it remain inadequate. Fluorofenidone (AKF-PD) is a novel pyridone agent able to ameliorate hepatic fibrosis in an experimental hepatic fibrosis model induced by dimethylnitrosamine. However, the underlying mechanism remains to be further elucidated. In light of the critical role of the NF-κB pathway in inflammation and hepatic fibrosis, together with the preliminary finding that AKF-PD decreases the release of proinflammatory cytokines in the endotoxemia and unilateral ureteral occlusion model, the aim of this study was to explore whether AKF-PD exerts an antifibrotic effect in hepatic fibrosis by inhibiting inflammation and suppressing the activation of the NF-κB pathway in vivo and in vitro. To test this possibility, the effect of AKF-PD on hepatic fibrosis models induced by both carbon tetrachloride (CCL4 ) and porcine serum (PS) was investigated. Our results showed that AKF-PD treatment ameliorated hepatic injury and fibrosis in both models. Furthermore, the administration of AKF-PD induced a robust anti-inflammatory reaction revealed by the downregulation of the proinflammatory cytokines as well as the suppression of the infiltration of inflammatory cells in the fibrotic liver. The analysis of the mechanism of action demonstrated that the attenuation of the production of proinflammatory cytokines and chemokines mediated by AKF-PD in vivo and in vitro were accompanied by the suppression in the activation of the NF-κB signaling pathway. In conclusion, AKF-PD might be considered as an antifibrotic agent attenuating hepatic inflammation and fibrosis potentially through the suppression of the NF-κB pathway.

Hyper-activation of NLRP3 inflammasomes contributes to the development of endotoxemia, but the molecular mechanisms are poorly defined. Tang et al. demonstrate that sequential ubiquitination of NLRP3 is crucial to keep NLRP3 inflammasomes in check and limits endotoxemia., Aberrant NLRP3 inflammasome activation contributes to the development of endotoxemia. The importance of negative regulation of NLRP3 inflammasomes remains poorly understood. Here, we show that the E3 ubiquitin ligase Cbl-b is essential for preventing endotoxemia induced by a sub-lethal dose of LPS via a caspase-11/NLRP3–dependent manner. Further studies show that NLRP3 undergoes both K63- and K48-linked polyubiquitination. Cbl-b binds to the K63-ubiquitin chains attached to the NLRP3 leucine-rich repeat domain (LRR) via its ubiquitin-associated region (UBA) and then targets NLRP3 at K496 for K48-linked ubiquitination and proteasome-mediated degradation. We also identify RNF125 as an additional E3 ubiquitin ligase that initiates K63-linked ubiquitination of the NLRP3 LRR domain. Therefore, NLRP3 is sequentially ubiquitinated by K63- and K48-linked ubiquitination, thus keeping the NLRP3 inflammasomes in check and restraining endotoxemia.

AIM To observe gene polymorphisms of TPMT and NUDT15, and compare their predictive value for azathioprine (AZA)-induced leukopenia in inflammatory bowel disease (IBD). METHODS This study enrolled 219 patients diagnosed with IBD in Xiangya Hospital, Central South University, Changsha, China from February 2016 to November 2017. Peripheral blood of all patients was collected to detect their genotypes of TPMT and NUDT15 by pyrosequencing at the Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital. Eighty patients were treated with AZA according to the disease condition. During the first month, patients who received AZA underwent routine blood tests and liver function tests once a week. The endpoint of the study was leukopenia induced by AZA. By analyzing patient characteristics, genotypes and leukopenia induced by drug use, we found the risk factors associated with AZA-induced leukopenia. RESULTS There were 219 patients with IBD (160 men and 59 women), including 39 who were confirmed with ulcerative colitis (UC), 176 with Crohn’s disease (CD) and 4 with undetermined IBD (UIBD). There were 44 patients (20.1%) with mutant genotype of NUDT15 (C/T); among them, 16 received AZA, and 8 (50%) developed leukopenia. There were 175 patients (79.7%) with wild genotype of NUDT15 (C/C); among them, 64 received AZA, and 11 (17.2%) developed leukopenia. A significant difference was found between NUDT15 C/T and its wild-type C/C (P = 0.004). There were only 3 patients with TPMT mutant genotype of A/G (1.4%) who participated in the research, and 1 of them was treated with AZA and developed leukopenia. The remaining 216 patients (98.6%) were found to bear the wild genotype of TPMT (A/A); among them, 79 patients received AZA, and 18 (22.8%) developed leukopenia, and there was no significant difference from those with A/G (P = 0.071). The frequency of TPMT mutation was 1.4%, and NUDT15 mutation rate was significantly higher and reached 20.1% (P = 0.000). Therefore, NUDT15 gene polymorphism was obviously a better biomarker than TPMT gene polymorphism in the prediction of AZA-induced leukopenia. CONCLUSION Mutation rate of NUDT15 in Chinese IBD patients is higher than that of TPMT. NUDT15 polymorphism is a better predictor for AZA-induced leukopenia than TPMT polymorphism.

Oxidative stress, inflammation and fibrosis can cause irreversible damage on cell structure and function of kidney and are key pathological factors in Diabetic Nephropathy (DN). Therefore, multi-target agents are urgently need for the clinical treatment of DN. Using Pirfenidone as a lead compound and based on the previous research, two novel series (5-trifluoromethyl)-2(1H)-pyridone analogs were designed and synthesized. SAR of (5-trifluoromethyl)-2(1H)-pyridone derivatives containing nitrogen heterocyclic ring have been established for in vitro potency. In addition, compound 8, a novel agent that act on multiple targets of anti-DN with IC50 of 90μM in NIH3T3 cell lines, t1/2 of 4.89±1.33h in male rats and LD50>2000mg/kg in mice, has been advanced to preclinical studies as an oral treatment for DN.

Suitable and efficient treatments for Henoch-Schonlein purpura nephritis (HSPN) with proteinuria remains unclear. Whether steroids combined with immunosuppressive agents improves prognosis compared to steroid therapy alone also remains controversial. This study explored whether combined therapy reduces proteinuria in HSPN patients with different pathological features. Chinese patients (n = 84) diagnosed with HSPN with proteinuria by renal biopsy between 2010 and 2019 were retrospectively studied. Patients were grouped into the steroid group (control) or the combined steroid and immunosuppressant group. Estimated glomerular filtration rate (eGFR) (mL/min/1.73 m2/y) and proteinuria were measured. The primary outcome progression was analyzed using Kaplan–Meier survival curves. The effect of the combined therapy on renal outcome was analyzed by multivariable Cox regression. Propensity score matching and sensitivity analysis were used to explore whether pathological features impacted prognosis. Patients who received combined steroid and immunosuppressant therapy were more likely to recover from HSPN and had proteinuria

Diabetic nephropathy (DN) is a major complication of diabetes. Currently, drugs are not available to effectively control the disease. Fluorofenidone (AKF-PD) is a recently developed drug; it possesses activities in reducing DN progression in preclinical research. Nonetheless, its renal protection and the underlying mechanisms have not been thoroughly investigated. We report here that AKF-PD significantly alleviatesrenal oxidative stress (OS) in db/dbmice through downregulation of Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase and upregulation of glutathione peroxidase and superoxide dismutase, thereby protecting kidney from DN pathogenesis. AKF-PD likely reduces OS through the advanced glycation end products (AGE) and protein kinase C (PKC) pathways. While renal AGEs, PKCα, PKCβ, and NADPH oxidase 4 (NOX4) were all substantially upregulated in db/db mice compared to db/m animals, AKF-PD robustly downregulated all these events to the basal levelsdetected in db/m mice. In primary human renal mesangial cells (HMCs), high glucose (HG) elevated receptor for advanced glycation endproducts (RAGE), PKCα, PKCβ and NOX4 activity, and induced the production of reactive oxygen species (ROS); these events were all inhibited by AKF-PD. Furthermore, HG led to mitochondrial damagein HMCs;AKF-PD conferred protection on the damage. Knockdown of either PKCα or PKCβ reduced HG-induced ROS production and mitochondrial damage in HMCs. The knockdown significantly enhanced AKF-PD-mediated inhibition of ROS production and mitochondrial damage in HG-treated HMCs. Collectively, our study demonstrates that AKF-PD protects renal function under diabetes conditions in part through inhibition of OS during DN pathogenesis. AKF-PD can be explored for clinical applications in DN therapy.

Background and aims Glutathione S-transferase A3 (GSTA3) is known as an antioxidative protease, however, the crucial role of GSTA3 in liver fibrosis remains unclear. As a recently we developed water-soluble pyridone agent with antifibrotic features, fluorofenidone (AKF-PD) can attenuate liver fibrosis, present studies were designed to explore the role of GSTA3 in liver fibrosis and its modulation by AKF-PD in vivo and in vitro. Methods Rats liver fibrosis models were induced by dimethylnitrosamine (DMN) or carbon tetrachloride (CCl4). The two activated hepatic stellate cells (HSCs) lines, rat CFSC-2G and human LX2 were treated with AKF-PD respectively. The lipid peroxidation byproduct malondialdehyde (MDA) in rat serum was determined by ELISA. The accumulation of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescein fluorescence analysis. The expression of α-smooth muscle actin (α-SMA), fibronectin (FN), and phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK) and glycogen synthase kinase 3 beta (GSK-3β) were detected by western blotting (WB). Results GSTA3 was substantially reduced in the experimental fibrotic livers and transdifferentiated HSCs. AKF-PD alleviated rat hepatic fibrosis and potently inhibited HSCs activation correlated with restoring GSTA3. Moreover, GSTA3 overexpression prevented HSCs activation and fibrogenesis, while GSTA3 knockdown enhanced HSCs activation and fibrogenesis resulted from increasing accumulation of ROS and subsequent amplified MAPK signaling and GSK-3β phosphorylation. Conclusions We demonstrated firstly that GSTA3 inhibited HSCs activation and liver fibrosis through suppression of the MAPK and GSK-3β signaling pathways. GSTA3 may represent a promising target for potential therapeutic intervention in liver fibrotic diseases.

Mefunidone is a new pyridone agent that attenuates renal tubulointerstitial fibrosis. However, the signaling pathways involved in the effect of mefunidone on renal tubulointerstitial fibrosis have not been well explained. Inflammatory response initiates and promotes renal tubulointerstitial fibrosis, and the inhibitor of nuclear factor kappa-B kinase beta (IKKβ) is a master regulator of inflammation. This study is determined to clarify the influence of mefunidone on renal inflammation and the phosphorylation of IKKβ. Experimental renal tubulointerstitial fibrosis was induced by unilateral ureteral obstruction (UUO) for 3, 7 and 14days in sprague dawley rat. Treatment with mefunidone was conducted simultaneously. Obstructed kidneys were harvested for the assessment. Our results showed that treatment with mefunidone ameliorated renal inflammatory injury, renal tubular lesions and interstitial fibrosis. Further studies indicated that treatment with mefunidone mitigated the expressions of tumor necrosis factorα (TNFα) and interleukin-1β (IL-1β) in the kidney. The phosphorylation of IKKβ and inhibitor of kappa-B (IκB) and the expression of NOD-like receptor family, pyrin domain containing 3 (NALP3) were also reduced in vivo after treatment with mefunidone. In vitro, peritoneal macrophages were incubated with necrotic cells or lipopolysaccharide in the presence or absence of mefunidone. Mefunidone markedly decreased necrotic cell or LPS induced IL-1β production and LPS induced TNFα production in primary peritoneal macrophages. Furthermore, mefunidone significantly inhibited the phosphorylation of IKKβ/IκB and nuclear transition of NF-κB p65 in peritoneal macrophages stimulated by necrotic cell or lipopolysaccharide. In conclusion, mefunidone serves as a novel anti-inflammatory agent that attenuates UUO-induced renal interstitial inflammation and fibrosis, possibly through suppressing IKKβ phosphorylation.

BACKGROUND: Oxygen deprivation or hypoxia in the kidney drives CKD and contributes to end organ damage. The erythrocyte’s role in delivery of oxygen (O(2)) is regulated by hypoxia, but the effects of CKD are unknown. METHODS: We screened all of the metabolites in the whole blood of mice infused with angiotensin II (Ang II) at 140 ng/kg per minute up to 14 days to simulate CKD and compared their metabolites with those from untreated mice. Mice lacking a receptor on their erythrocytes called ADORA2B, which increases O(2) delivery, and patients with CKD were studied to assess the role of ADORA2B-mediated O(2) delivery in CKD. RESULTS: Untargeted metabolomics showed increased production of 2,3-biphosphoglycerate (2,3-BPG), an erythrocyte-specific metabolite promoting O(2) delivery, in mice given Ang II to induce CKD. Genetic studies in mice revealed that erythrocyte ADORA2B signaling leads to AMPK-stimulated activation of BPG mutase, promoting 2,3-BPG production and O(2) delivery to counteract kidney hypoxia, tissue damage, and disease progression in Ang II–induced CKD. Enhancing AMPK activation in mice offset kidney hypoxia by triggering 2,3-BPG production and O(2) delivery. Patients with CKD had higher 2,3-BPG levels, AMPK activity, and O(2) delivery in their erythrocytes compared with controls. Changes were proportional to disease severity, suggesting a protective effect. CONCLUSIONS: Mouse and human evidence reveals that ADORA2B-AMPK signaling cascade–induced 2,3-BPG production promotes O(2) delivery by erythrocytes to counteract kidney hypoxia and progression of CKD. These findings pave a way to novel therapeutic avenues in CKD targeting this pathway.

To investigate the effect of fluorofenidone on renal interstitial fibrosis in rats with unilateral ureteral obstruction (UUO) and to observe the effect of fluorofenidone on the expressions of collagen type I (Col I), collagen type III (Col III), α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), platelet derived growth factor (PDGF) in the renal tissues of UUO rats. Methods: Male Sprague-Dawley (SD) rats were randomly divided into a sham-operated group, a UUO group, and a flurofenidone group (n=5). UUO model was induced by ligating the left ureter in rats. The rats were treated with 125 mg/(kg.d) fluorofenidone by gastric gavage in the fluorofenidone group at 24 h before the operation, and the rats were treated with the identical dose of 0.5% sodium carboxyl methyl cellulose (CMC-Na) in the other 2 groups. The rats were sacrificed at 14 days after UUO. Pathological changes of the renal tissue were observed by HE and Masson staining, the mRNA expressions of Col I, Col III, α-SMA, PDGF and CTGF were detected by real-time PCR, and the protein expressions of Col I, Col III, PDGF and CTGF were detected by immunohistochemical staining. Results: The renal interstitial damage index, relative collagen area and mRNA and protein expressions of Col I and Col III in the renal tissues of the rats in the UUO group significantly increased (P0.05), and fluorofenidone could reduce these indexes (P0.05). Compared with the sham-operated group, the protein expressions of α-SMA, PDGF, CTGF and the mRNA expressions of PDGF and CTGF in the renal tissues of the rats in the UUO group were increased, but fluorofenidone could decrease the protein expressions of α-SMA, PDGF, CTGF and the mRNA expressions of PDGF and CTGF (P0.05). Conclusion: Fluorofenidone (125 mg/kg.d) could attenuate renal interstitial fibrosis through inhibition of fibroblast proliferation, myofibroblastic activation, PDGF and CTGF expression.目的：观察氟非尼酮对单侧输尿管梗阻大鼠肾间质纤维化的疗效，探讨氟非尼酮对肾间质纤维化大鼠肾组织中I型胶原(collagen type I，Col I)，III型胶原(collagen type III，Col III)，α-平滑肌肌动蛋白(α-smooth muscle actin，α-SMA)，结缔组织生长因子(connective tissue growth factor，CTGF)和血小板源性生长因子(platelet derived growth factor，PDGF)表达的影响。方法：将15只雄性SD大鼠随机分为假手术组、模型组和氟非尼酮组(n=5)。对模型组和氟非尼酮组大鼠行左侧输尿管结扎术建立单侧输尿管梗阻模型。氟非尼酮组从造模前24 h开始以氟非尼酮[125 mg/(kg.d)]溶于0.5%羧甲基纤维素钠(sodium carboxyl methyl cellulose，CMC-Na)中灌胃，模型组和假手术组以等体积0.5% CMC-Na灌胃。于术后14 d处死大鼠，取梗阻侧肾组织行HE和Masson染色观察各组大鼠肾组织病理改变；用免疫组织化学检测Col I，Col III，α-SMA，PDGF，CTGF的蛋白表达；用RT-PCR检测Col I，Col III，PDGF，CTGF mRNA表达。结果：模型组肾间质损伤指数、胶原相对面积评分及Col I，Col III mRNA和蛋白表达均较假手术组增高(P0.05)，氟非尼酮治疗后明显改善(P0.05)。模型组肾组织α-SMA，PDGF，CTGF蛋白表达及PDGF，CTGF mRNA表达均较假手术组明显增加(P0.05)，氟非尼酮治疗后表达均明显减少(P0.05)。结论：氟非尼酮(125 mg/kg.d)能够显著改善单侧输尿管梗阻大鼠肾间质纤维化，其作用机制与抑制肌成纤维细胞的活化及关键促纤维化因子PDGF和CTGF的表达有关。.

Renal interstitial fibrosis is a common renal injury resulted from a variety of chronic kidney conditions and an array of factors. We report here that Notch3 is a potential contributor. In comparison to 6 healthy individuals, a robust elevation of Notch3 expression was observed in the renal tubular epithelial cells of 18 patients with obstructive nephropathy. In a rat unilateral ureteral obstruction (UUO) model which mimics the human disease, Notch3 upregulation closely followed the course of renal injury, renal fibrosis, TGFβ expression, and alpha-smooth muscle actin (α-SMA) expression, suggesting a role of Notch3 in promoting tubulointerstitial fibrosis. This possibility was supported by the observation that TGFβ, the major renal fibrogenic cytokine, stimulated Notch3 expression in human proximal tubule epithelial HK-2 cells. TGFβ enhanced the activation of ERK, p38, but not JNK MAP kinases in HK-2 cells. While inhibition of p38 activation using SB203580 did not affect TGFβ-induced Notch3 expression, inhibition of ERK activation with a MEK1 inhibitor PD98059 dramatically reduced the event. Furthermore, enforced ERK activation through overexpression of the constitutively active MEK1 mutant MEK1Q56P upregulated Notch3 expression in HK-2 cells, and PD98059 reduced ERK activation and Notch3 expression in HK-2 cells expressing MEK1Q56P. Collectively, we provide the first clinical evidence for Notch3 upregulation in patients with obstructive nephropathy; the upregulation is likely mediated through the TGFβ-ERK pathway. This study suggests that Notch3 upregulation contributes to renal injury caused by obstructive nephropathy, which could be prevented or delayed through ERK inhibition.

Interleukin-1 beta (IL-1β) is a potent pro-inflammatory and pro-fibrotic cytokine that plays an important role in renal fibrosis. Fluorofenidone (AKF-PD) is a novel pyridone agent that exerts a strong renal anti-fibrotic effect. We previously found that administration of AKF-PD could significantly attenuate IL-1β production in vitro and in vivo. However, the underlying mechanism is not fully understood. Here we show that AKF-PD has no effect on the expression of pro-IL-1β in activated mouse macrophages in vitro. Instead, AKF-PD inhibits the inflammasome, lowering caspase-1 levels and thereby decreasing cleavage of pro-IL-1β into IL-1β. AKF-PD was found to block inflammasome activity induced by various signals, including ATP, alum crystals, and Salmonella typhimurium. These results provide a novel mechanistic insight into how AKF-PD exerts its anti-inflammatory and anti-fibrotic activities, and suggest that AKF-PD might block IL-1β production via suppression of inflammasomes in renal fibrosis. In addition, the results suggest that AKF-PD may be of therapeutic potential in other inflammasome-related diseases.

Renal interstitial fibrosis closely relates to chronic kidney disease and is regarded as the final common pathway in most cases of end-stage renal disease. Metabolomic biomarkers can facilitate early diagnosis and allow better understanding of the pathogenesis underlying renal fibrosis. Gas chromatography-mass spectrometry (GC/MS) is one of the most promising techniques for identification of metabolites. However, the existence of the background, baseline offset, and overlapping peaks makes accurate identification of the metabolites unachievable. In this study, GC/MS coupled with chemometric methods was successfully developed to accurately identify and seek metabolic biomarkers for rats with renal fibrosis. By using these methods, seventy-six metabolites from rat serum were accurately identified and five metabolites (i.e., urea, ornithine, citric acid, galactose, and cholesterol) may be useful as potential biomarkers for renal fibrosis.

Background This study aimed to compare clinical features and health-related quality of life (HRQoL) in the Chinese chronic kidney disease (CKD) 3 population and determined the necessity of the subdivision of CKD3 in Chinese patients with CKD. Methods Participants with stage 3 CKD (18–74 years of age) were recruited at 39 clinical centers located at 28 cities in 22 provinces of China. The sociodemographic status, medical history, anthropometric measurements, and lifestyle behaviors were documented at entry, and blood and urine samples were collected. The estimated glomerular filtration rate was calculated using the CKD-EPI creatinine equation. The HRQoL was evaluated using the kidney disease quality-of-life instrument. A linear regression model was used to estimate the association between HRQoL and CKD stages (G3b vs G3a). Results The levels of intact parathyroid hormone, systolic blood pressure, uric acid, and high-density lipoprotein cholesterol were statistically significantly higher, whereas the levels of serum bicarbonate and hemoglobin were statistically significantly lower in the G3b group compared with the G3a group. Compared with CKD G3a group, the proportions of subjects with hyperuricemia and anemia were significantly higher in CKD G3b group (61.4% vs. 52.0% and 26.4% vs. 17.9%, respectively, P

We explored whether Fluorofenidone reduced interleukin-1β (IL-1β) production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction (UUO).Ureteral obstruction rats were treated with Fluorofenidone (500 mg/kg per day) for 3, 7 days. Morphologic analysis and leukocytes infiltration were assessed in ligated kidneys. Furthermore, plasmids of NLRP3, ASC, pro-Caspase-1, pro-IL-1β were co-transfected into 293 T cells, and then treated with Fluorofenidone (2 mM). The expression of NLRP3, ASC, pro-caspase-1, cleavage caspase-1, pro-IL-1β and cleavage IL-1β were measured by Western blot or real-time PCR in vivo and in vitro. Moreover the interaction of NLRP3 inflammasome-assembly was detected by co-immunoprecipitation and confocal immunofluorescence.Fluorofenidone treatment significantly attenuated renal fibrosis and leukocytes infiltration in UUO model. Fluorofenidone had no effect on the expression of pro-IL-1β. Interestingly, Fluorofenidone inhibited the activation of NLRP3 inflammasome, downregulated Caspase-1 levels and thereby decreased the cleavage of pro-IL-1β into IL-1β in vivo and in vitro. Fluorofenidone treatment distinctively weakened the interaction between NLRP3 and ASC, as well as ASC and pro-Caspase-1 in vivo. However, Fluorofenidone treatment only significantly weakened the interaction between ASC and pro-Caspase-1 in co-transfected 293 T cells.Fluorofenidone serves as a novel anti-inflammatory agent that attenuates IL-1β production in UUO model by interacting with NLRP3 inflammasome.

Background Accumulated evidence indicates that inflammation plays a critical role in the progression of many renal diseases. Fluorofenidone (AKF-PD) has been shown to attenuate renal fibrosis in a number of experimental renal fibrosis models. The aim of this study was to assess the anti-inflammatory effect of AKF-PD. Methods Human proximal tubule (HK-2) cells were stimulated with tumor necrosis factor (TNF)-α in the presence or absence of AKF-PD. Mouse peritoneal macrophages were incubated with necrotic MES-13 cells in the presence or absence of AKF-PD. The production of pro-inflammatory cytokines and chemokines was measured by enzyme-linked immunosorbent assay, and the activation of Nuclear factor kB (NF-κB) pathway was assessed by Western blot analysis. Results AKF-PD significantly inhibited TNF-α-induced expression of interleukin-6, monocyte chemoattractant protein-1 and interleukin-8 and nuclear translocation of p65 in HK-2 cells. Addition of AKF-PD also significantly suppressed necrotic cell-induced TNF-α expression and p65 nuclear translocation in mouse peritoneal macrophages. Conclusions These results demonstrated that AKF-PD exerts anti-inflammatory effect, at least in part, through inhibition of the NF-κB pathway.

Insulin delivery and transendothelial insulin transport are two discrete steps that limit muscle insulin action. Angiotensin II type 1 receptor (AT1R) blockade recruits microvasculature and increases glucose use in muscle. Increased muscle microvascular perfusion is associated with increased muscle delivery and action of insulin. To examine the effect of acute AT1R blockade on muscle insulin uptake and action, rats were studied after an overnight fast to examine the effects of losartan on muscle insulin uptake ( protocol 1), microvascular perfusion ( protocol 2), and insulin's microvascular and metabolic actions in the state of insulin resistance ( protocol 3). Endothelial cell insulin uptake was assessed, using125I-insulin as tracer. Systemic lipid infusion was used to induce insulin resistance. Losartan significantly increased muscle insulin uptake (∼60%, P < 0.03), which was associated with a two- to threefold increase in muscle microvascular blood volume (MBV; P = 0.002) and flow (MBF; P = 0.002). Losartan ± angiotensin II had no effect on insulin internalization in cultured endothelial cells. Lipid infusion abolished insulin-mediated increases in muscle MBV and MBF and lowered insulin-stimulated whole body glucose disposal ( P = 0.0001), which were reversed by losartan administration. Inhibition of nitric oxide synthase abolished losartan-induced muscle insulin uptake and reversal of lipid-induced metabolic insulin resistance. We conclude that AT1R blockade increases muscle insulin uptake mainly via microvascular recruitment and rescues insulin's metabolic action in the insulin-resistant state. This may contribute to the clinical findings of decreased cardiovascular events and new onset of diabetes in patients receiving AT1R blockers.

Tubular epithelial-mesenchymal transition (EMT) has been widely accepted as the underlying mechanisms of renal interstitial fibrosis (RIF). The production of reactive oxygen species (ROS) plays a vital role in tubular EMT process. The purpose of this study was to investigate the involved molecular mechanisms in TGF-beta-induced EMT and identify the potential role of glutathione S-transferase alpha 3 (GSTA3) in this process. The iTRAQ screening was performed to identify protein alterations of the rats underwent unilateral-ureteral obstruction (UUO). Protein expression of GSTA3 in patients with obstructive nephropathy and UUO rats was detected by immunohistochemistry. Protein and mRNA expression of GSTA3 in UUO rats and NRK-52E cells were determined by Western blot and RT-PCR. siRNA and overexpression plasmid were transfected specifically to assess the role of GSTA3 in RIF. The generation of ROS was measured by dichlorofluorescein fluorescence analysis. GSTA3 protein and mRNA expression was significantly reduced in UUO rats. Immunohistochemical analysis revealed that GSTA3 expression was reduced in renal cortex in UUO rats and patients with obstructive nephropathy. Treating with TGF-β1 down-regulated GSTA3 expression in NRK-52E cells, which have been found to be correlated with the decreased expression in E-cadherin and megalin and increased expression in α-smooth muscle actin. Furthermore, knocking down GSTA3 in NRK-52 cells led to increased production of ROS and tubular EMT, whereas overexpressing GSTA3 ameliorated ROS production and prevented the occurrence of tubular EMT. GSTA3 plays a protective role against tubular EMT in renal fibrosis, suggesting GSTA3 is a potential therapeutic target for RIF.

Fluorofenidone (FD) is a novel pyridone agent with significant antifibrotic effects in vitro. The purpose of this study is to investigate the effects of FD on renal interstitial fibrosis in rats with obstructive nephropathy caused by unilateral ureteral obstruction (UUO). With pirfenidone (PD, 500 mg/kg/day) and enalapril (10 mg/kg/day) as the positive treatment controls, the rats in different experimental groups were administered with FD (500 mg/kg/day) from day 4 to day 14 after UUO. The tubulointerstitial injury, interstitial collagen deposition, and expression of type I and type III collagen, transforming growth factor-β(1) (TGF-β(1)), connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), α-smooth muscle actin (α-SMA), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were assessed. FD treatment significantly attenuated the prominently increased scores of tubulointerstitial injury, interstitial collagen deposition, and protein expression of type I and type III collagen in ureter-obstructed kidneys, respectively. As compared with untreated rats, FD also significantly reduced the expression of α-SMA, TGF-β(1), CTGF, PDGF, and inhibitor of TIMP-1 in the obstructed kidneys. Fluorofenidone attenuates renal interstitial fibrosis in the rat model of obstructive nephropathy through its regulation on fibrogenic growth factors, tubular cell transdifferentiation, and extracellular matrix.

Resveratrol, a polyphenol found in many plants, has antioxidant and anti-inflammatory actions. It also improves endothelial function and may be cardioprotective. Tumor necrosis factor-α (TNFα) causes oxidative stress and microvascular endothelial dysfunction. Whether resveratrol affects microvascular function in vivo and, if so, whether inflammatory cytokines antagonize its microvascular action are not clear. In cultured bovine aortic endothelial cells (BAECs), reserveratrol (100 nM) increased the phosphorylation of protein kinase B (Akt), endothelial nitric oxide (NO) synthase (eNOS), and ERK1/2 within 15 min by more than twofold, and this effect lasted for at least 2 h. Treatment of BAECs with TNFα (10 ng/ml) significantly increased the NADPH oxidase activity and the production of hydrogen peroxide and superoxide. Pretreatment of cells with resveratrol (100 nM) prevented each of these. Injection (ip) of resveratrol in rats potently increased muscle microvascular blood volume (MBV; P = 0.007) and flow (MBF; P < 0.02) within 30 min, and this was sustained for at least 2 h. The phosphorylation of Akt in liver or muscle was unchanged. Superimposed systemic infusion of l-NAME (NOS inhibitor) completely abolished resveratrol-induced increases in MBV and MBF. Similarly, systemic infusion of TNFα prevented resveratrol-induced muscle microvascular recruitment. In conclusion, resveratrol activates eNOS and increases muscle microvascular recruitment via an NO-dependent mechanism. Despite the potent antioxidant effect of resveratrol, TNFα at concentrations that block insulin-mediated muscle microvascular recruitment completely neutralized resveratrol's microvascular action. Thus, chronic inflammation, as seen in type 2 diabetes, may limit resveratrol's vasodilatory actions on muscle microvasculature.

Background: Novel therapeutic agents are urgently needed to combat renal fibrosis. The purpose of this study was to assess, using complete unilateral ureteral obstruction (UUO) in rats, whether fluorofenidone (AKF-PD) [1-(3-fluorophenyl)-5-methyl-2-(1H)-pyridone] inhibits renal fibrosis, and to determine whether it exerts its inhibitory function on renal fibroblast activation. Methods: Sprague-Dawley rats were randomly divided into 3 groups: sham operation, UUO and UUO/AKF-PD (500 mg/kg/day). Renal function, tubulointerstitium damage index score, extracellular matrix (ECM) deposition, and the expressions of TGF-β1, collagen III, α-SMA, p-Smad2, p-Smad3, p-ERK1/2, p-JNK and p-p38 were measured. In addition, the expressions of α-SMA, fibronectin, CTGF, p-Smad2/3, p-ERK1/2, p-p38 and p-JNK were measured in TGF-β1-stimulated normal rat renal fibroblasts (NRK-49F). Results: AKF-PD treatment significantly attenuated tubulointerstitium damage, ECM deposition, the expressions of TGF-β1, collagen III, α-SMA, p-ERK1/2, p-p38 and p-JNK in vivo. In vitro, AKF-PD dose-dependently inhibited expressions of α-SMA, fibronectin and CTGF. Furthermore, AKF-PD did not inhibit Smad2/3 phosphorylation or nuclear accumulation, but rather attenuated ERK, p38 and JNK activation. Conclusion: AKF-PD treatment inhibits the progression of renal interstitial fibrosis in obstructed kidneys; this is potentially achieved by suppressing fibroblast activation. Therefore, AKF-PD is a special candidate for the treatment of renal fibrosis.

The pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release proinflammatory factors like TNF-alpha and IL-1beta. Fluorofenidone (AKF-PD) is a novel pyridone agent, which exerts a strong antifibrotic effect. In this work, we showed that AKF-PD also exert an inhibitory effect on acute systemic inflammatory response. AKF-PD treatment significantly increased survival in animals with established endotoxemia. In addition, AKF-PD treatment significantly reduced circulating levels of TNF-alpha and IL-1beta during endotoxemia. In macrophage cultures, AKF-PD inhibited the release of TNF-alpha and IL-1beta in a dose-dependent manner. In conclusion, these results indicate that AKF-PD inhibits the release of the proinflammatory cytokines (TNF-a and IL-1beta) and improves survival during lethal endotoxemia, which suggest this new pyridone agent can be a novel candidate for therapy of septic shock.

Background: It is still not known whether the spinal cytokine signaling pathways are involved in the pathophysiologic mechanism of the acute phase of heart disease. This study examines the expression pattern of tumor necrosis factor-α (TNF-α) and its two related mitogenic-activated protein kinases, p38 and Jun-N-terminal kinase (JNK), in the spinal cord in response to acute cardiac injury (ACI). Methods: The ACI rat model was established by intra-myocardial injection of formalin. At the indicated times after the establishment of ACI, the thoracic segments of the spinal cord were harvested and Western blot was performed to determine the expression of TNF-α, p38 and JNK. The localization of the cytokine and the kinases was determined by immunohistochemistry and double immunofluorescence. Results: In response to ACI, TNF-α protein was up-regulated and reached a peak level at 6 h after ACI. The up-regulated TNF-α was distributed in all the laminae in the spinal cord and mainly localized in the neurons, as determined by immunohistochemistry and double immunofluorescence. In response to ACI, p38 and JNK were also up-regulated in the spinal cord. The expression profiles of p38 and JNK were similar to that of activated TNF-α following ACI. Conclusions: This study shows that cardiac injury can induce the activation of spinal TNF-α, p38 and JNK. The activated spinal cytokine signaling may contribute to disease progression in the acute phase of cardiac injury in clinical practice.

Interleukin (IL)‐1β plays an important role in the pathogenesis of idiopathic pulmonary fibrosis. The production of IL‐1β is dependent upon caspase‐1‐containing multiprotein complexes called inflammasomes and IL‐1R1/MyD88/NF‐κB pathway. In this study, we explored whether a potential anti‐fibrotic agent fluorofenidone (FD) exerts its anti‐inflammatory and anti‐fibrotic effects through suppressing activation of NACHT, LRR and PYD domains‐containing protein 3 (NALP3) inflammasome and the IL‐1β/IL‐1R1/MyD88/NF‐κB pathway in vivo and in vitro. Male C57BL/6J mice were intratracheally injected with Bleomycin (BLM) or saline. Fluorofenidone was administered throughout the course of the experiment. Lung tissue sections were stained with haemotoxylin and eosin and Masson's trichrome. Cytokines were measured by ELISA, and α‐smooth muscle actin (α‐SMA), fibronectin, collagen I, caspase‐1, IL‐1R1, MyD88 were measured by Western blot and/or RT‐PCR. The human actue monocytic leukaemia cell line (THP‐1) were incubated with monosodium urate (MSU), with or without FD pre‐treatment. The expression of caspase‐1, IL‐1β, NALP3, apoptosis‐associated speck‐like protein containing (ASC) and pro‐caspase‐1 were measured by Western blot, the reactive oxygen species (ROS) generation was detected using the Flow Cytometry, and the interaction of NALP3 inflammasome‐associated molecules were measured by Co‐immunoprecipitation. RLE‐6TN (rat lung epithelial‐T‐antigen negative) cells were incubated with IL‐1β, with or without FD pre‐treatment. The expression of nuclear protein p65 was measured by Western blot. Results showed that FD markedly reduced the expressions of IL‐1β, IL‐6, monocyte chemotactic protein‐1 (MCP‐1), myeloperoxidase (MPO), α‐SMA, fibronectin, collagen I, caspase‐1, IL‐1R1 and MyD88 in mice lung tissues. And FD inhibited MSU‐induced the accumulation of ROS, blocked the interaction of NALP3 inflammasome‐associated molecules, decreased the level of caspase‐1 and IL‐1β in THP‐1 cells. Besides, FD inhibited IL‐1β‐induced the expression of nuclear protein p65. This study demonstrated that FD, attenuates BLM‐induced pulmonary inflammation and fibrosis in mice via inhibiting the activation of NALP3 inflammasome and the IL‐1β/IL‐1R1/MyD88/ NF‐κB pathway.

Background/Aims: We evaluated the therapeutic effects of fluorofenidone (AKF-PD), a novel pyridone agent, targeting oxidative stress and fibrosis in obstructive nephropathy. Methods: AKF-PD was used to treat renal interstitial fibrosis in unilateral ureteral obstruction (UUO) obstructive nephropathy in rats. The expression of NOX2 (gp91phox), fibronectin and extracellular signal regulated kinase (ERK) were detected by western blot. A level of Malondialdehyde (MDA), an oxidative stress marker, was measured by ELISA. In addition, ROS and the expressions of NOX2, collagen I (a1), fibronectin and p-ERK were measured in angiotensin (Ang) II-stimulated rat proximal tubular epithelial cells (NRK-52E) in culture. Results: In NRK-52E cells, AKF-PD reduced AngII induced expressions of ROS, NOX2, fibronectin, collagen I (a1) and p-ERK. In UUO kidney cortex, AKF-PD attenuated the degree of renal interstitial fibrosis, which was associated with reduced the expressions of collagen I (a1) and fibronectin. Furthermore, AKF-PD downregulated the expressions of NOX2, MDA and p-ERK. Conclusion: AKF-PD treatment inhibits the progression of renal interstitial fibrosis by suppressing oxidative stress and ERK/MAPK signaling pathway.

BACKGROUND:Inflammation has a crucial role in renal interstitial fibrosis, which is the common pathway of chronic kidney diseases. Mefunidone (MFD) is a new compound which could effectively inhibit the proliferation of renal fibroblasts in vitro. However, the overall effect of Mefunidone in renal fibrosis remains unknown. METHODS:Sprague-Dawley rats were randomly divided intro 6 groups: sham operation, unilateral ureteral obstruction (UUO), UUO/Mefunidone (25, 50, 100mg/kg/day) and UUO/PFD (500mg/kg/day). The rats were sacrificed respectively on days 3, 7, and 14 after the operation. Tubulointerstitial injury index, interstitial collagen deposition, expression of fibronectin (FN), α-smooth muscle actin (α-SMA), type I and III collagen and the number of CD3+ and CD68+ cells were determined. The expressions of proinflammatory cytokines, p-ERK, p-IκB, and p-STAT3 were measured in human renal proximal tubular epithelial cells of HK-2 or macrophages. RESULTS:Mefunidone treatment significantly attenuated tubulointerstitial injury, interstitial collagen deposition, expression of FN, α-SMA, type I and III collagen in the obstructive kidneys, which correlated with significantly reduced the number of T cells and macrophages in the obstructive kidneys. Mechanistically, Mefunidone significantly inhibited tumor necrosis factor-α (TNF-α-) or lipopolysaccharide (LPS)-induced production of proinflammatory cytokines. This effect is possibly due to the inhibition of phosphorylation of ERK, IκB, and STAT3. CONCLUSION:Mefunidone treatment attenuated tubulointerstitial fibrosis in a rat model of UUO, at least in part, through inhibition of inflammation.

Apoptosis is one of the most important mechanisms underlying renal tubulointerstitial fibrosis. We identified a role of protein Peroxiredoxin 1 (Prx1) in protecting apoptosis occurred in tubular epithelial cells of the rat and human kidney.Immunohistochemistry (IHC) staining was used to detect Prx1 expression in kidney derived from unilateral-ureteral obstruction (UUO) rats or patients with obstructive nephropathy. Modulation of Prx1 expression by transfecting siRNA and overexpression plasmid approach were carried out in NRK-52E (rat kidney tubular epithelial cell line) cells. UUO-induced apoptosis was determined using TUNEL assay.Immunohistochemistry staining showed that Prx1 expressed in the cytoplasm of renal tubular epithelial cells, in the kidneys of UUO rats. The reduction was confirmed by both IHC and real-time polymerase chain reaction following a course of renal tubulointerstitial fibrosis in UUO rats and a decrease of Prx1 occurred concomitantly with an elevation of TUNEL-positive cells. Fluorofenidone (AKF-PD), a new anti-tubulointerstitial fibrotic agent, attenuated Prx1 reduction in UUO rats. Furthermore, hydrogen peroxide (H2 O2 )-derived oxidative stress activated p38 MAPK, and induced apoptosis in NRK-52E cells; knockdown of Prx1 sensitized both events in NRK-52E cells, and overexpression of Prx1 diminished the apoptosis and the phosphorylation of p38 CONCLUSION: Downregulation of Prx1 occurred in renal tubular epithelial cells of UUO rats and patients with obstructive nephropathy. Prx1 may alleviate the pathogenesis by inhibiting H2 O2 -induced apoptosis via inhibiting the p38 MAPK pathway. Prx1 may represent a useful target for a protective therapy towards renal tubulointerstitial fibrosis.

Signaling through the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway, especially JAK2/STAT3, is involved in renal fibrosis. Fluorofenidone (FD), a novel pyridone agent, exerts anti-fibrotic effects in vitro and in vivo. Herein, we sought to investigate whether FD demonstrates its inhibitory function through preventing JAK2/STAT3 pathway. In this study, we examined the effect of FD on activation of rat renal interstitial fibroblasts, glomerular mesangial cells (GMC), and expression of JAK2/STAT3. Moreover, we explored the histological protection effects of FD in UUO rats, db/db mice, and phosphorylation of JAK2/STAT3 cascade. Our studies found that pretreatment with FD resulted in blockade of activation of fibroblast and GMC manifested by fibronectin (FN) and α-smooth muscle actin (α-SMA) protein expression and decline of STAT3 tyrosine phosphorylation induced by IL-6 or high glucose. In unilateral ureteral obstruction rats and a murine model of spontaneous type 2 diabetes (db/db mice), treatment with FD blocked the expression of FN and α-SMA, prevented renal fibrosis progression, and attenuated STAT3 activation. However, FD administration did not interfere with JAK2 activation both in vivo and in vitro. In summary, the molecular mechanism by which FD exhibits renoprotective effects appears to involve the inhibition of STAT3 phosphorylation.

Apoptosis is one of the most important mechanisms underlying renal interstitial fibrosis. We identified the role of protein Niban in apoptosis of tumour cells. The purpose of this study was to assess the expression of Niban in renal interstitial fibrosis of humans and rats.Immunohistochemistry was used to detect Niban in patients with obstructive nephropathy. Proteomics and gene array analysis were performed to screen different molecules involved in the pathophysiology of unilateral-ureteral obstruction rats. We confirmed Niban using immunohistochemistry and Western blot in renal cortex of UUO rats and HK-2 cells. TUNEL assay and flow cytometry revealed apoptosis of renal tubular cells. siRNA and overexpression plasmid were transfected specifically to study the possible function of Niban.Niban was decreased apparently in renal tubular cells of patients with obstructive nephropathy, compared with controls. Niban decreased in renal cortex of UUO rats and transforming growth factor-β1 (TGF-β1)-stimulated HK-2 cells. siRNA of Niban increased apoptosis of HK-2 cells. TGF-β1 also increased apoptosis of HK-2 cells. Overexpression of Niban failed to diminish apoptosis of HK-2 cells induced by TGF-β1.Niban decreased in renal tubular cells of patients of obstructive nephropathy, UUO rats and TGF-β1 stimulated HK-2 cells. Suppressing Niban increases apoptosis in HK-2 cells. Niban may be associated with apoptosis of HK-2 cells.

To determine the characteristics and differences in bleomycin-induced lung fibrosis model by repeated low-dose intravenous injection and single dose intratracheal instillation of bleomycin.Forty male ICR (Institute for Cancer Research) mice were randomly divided into a model group I, a model group II, and 2 control groups (10 mice in each group). In model group I, bleomycin was injected intravenously at 10 mg/(kg.d) for 14 consecutive days; and in model group II, bleomycin was instilled intratracheally at 5 mg/kg. The 2 control groups were given isotonic saline solution. At the 28th day, the mice were sacrificed and the bronchoalveolar lavage fluid (BALF) was collected. The total cells and proteins in the BALF, pulmonary coefficient, and hydroxyproline (HYP) content were determined. The pathological changes were observed by the eosin staining and Masson's trichrome staining.1) Both intravenous injection and intratracheal instillation of bleomycin resulted in severe and extensive inflammation and fibrosis in the lungs. The total cells and proteins in the BALF, HYP content, pulmonary coefficient and the pathological score of pulmonary fibrosis were all significantly increased in the 2 model groups (P0.01). 2) Fibrosis was mainly under the pleura or around the vessel in model group I, and it was located near the bronehia and bronchioles in model group II. 3) The death rate was higher in the model group II than that in the model group I. 4) Proteins in the BALF were significantly higher in model group II than that in model group I (P0.05). There was no difference in the total cells in the BALF, the pulmonary coefficient, the HYP content, and the pathological score of pulmonary fibrosis between the 2 groups (P0.05).The pulmonary fibrosis model can be successfully established by intravenous injection or intratracheal instillation of bleomycin, but the sites of pulmonary fibrosis are different. The histological changes caused by the repeated low-dose intravenous injection of bleomycin is more similar to idiopathic pulmonary fibrosis than that by the single dose intratracheal instillation.

Fluorofenidone (AKF-PD) is a novel pyridone agent. The purpose of this study is to investigate the inhibitory effects of AKF-PD on liver fibrosis in rats and the involved molecular mechanism related to hepatic stellate cells (HSCs). Rats treated with dimethylnitrosamine or CCl4were randomly divided into normal, model, AKF-PD treatment, and pirfenidone (PFD) treatment groups. The isolated primary rat HSCs were treated with AKF-PD and PFD respectively. Cell proliferation and cell cycle distribution were analyzed by bromodeoxyuridine and flow cytometry, respectively. The expression of collagen I and α-smooth muscle actin (α-SMA) were determined by Western blot, immunohistochemical staining, and real-time RT-PCR. The expression of cyclin D1, cyclin E, and p27kip1and phosphorylation of MEK, ERK, Akt, and 70-kDa ribosomal S6 kinase (p70S6K) were detected by Western blot. AKF-PD significantly inhibited PDGF-BB-induced HSC proliferation and activation by attenuating the expression of collagen I and α-SMA, causing G0/G1 phase cell cycle arrest, reducing expression of cyclin D1and cyclin E, and promoting expression of p27kip1. AKF-PD also downregulated PDGF-BB-induced MEK, ERK, Akt, and p70S6K phosphorylation in HSCs. In rat liver fibrosis, AKF-PD alleviated hepatic fibrosis by decreasing necroinflammatory score and semiquantitative score, and reducing expression of collagen I and α-SMA. AKF-PD attenuated the progression of hepatic fibrosis by suppressing HSCs proliferation and activation via the ERK/MAPK and PI3K/Akt signaling pathways. AKF-PD may be used as a potential novel therapeutic agent against liver fibrosis.

Rationale: Hypertension is the most prevalent life-threatening disease worldwide and is frequently associated with chronic kidney disease (CKD). However, the molecular basis underlying hypertensive CKD is not fully understood. Objective: We sought to identify specific factors and signaling pathways that contribute to hypertensive CKD and thereby exacerbate disease progression. Methods and Results: Using high-throughput quantitative reverse-transcription polymerase chain reaction profiling, we discovered that the expression level of 5′-ectonucleotidase (CD73), a key enzyme that produces extracellular adenosine, was significantly increased in the kidneys of angiotensin II–infused mice, an animal model of hypertensive nephropathy. Genetic and pharmacological studies in mice revealed that elevated CD73-mediated excess renal adenosine preferentially induced A2B adenosine receptor (ADORA2B) production and that enhanced kidney ADORA2B signaling contributes to angiotensin II–induced hypertension. Similarly, in humans, we found that CD73 and ADORA2B levels were significantly elevated in the kidneys of CKD patients compared with normal individuals and were further elevated in hypertensive CKD patients. These findings led us to further discover that elevated renal CD73 contributes to excess adenosine signaling via ADORA2B activation that directly stimulates endothelin-1 production in a hypoxia-inducible factor-α–dependent manner and underlies the pathogenesis of the disease. Finally, we revealed that hypoxia-inducible factor-α is an important factor responsible for angiotensin II–induced CD73 and ADORA2B expression at the transcriptional level. Conclusions: Overall, our studies reveal that angiotensin II–induced renal CD73 promotes the production of renal adenosine that is a prominent driver of hypertensive CKD by enhanced ADORA2B signaling–mediated endothelin-1 induction in a hypoxia-inducible factor-α–dependent manner. The inhibition of excess adenosine-mediated ADORA2B signaling represents a novel therapeutic target for the disease.

Idiopathic pulmonary fibrosis is a progressive, life-threatening, interstitial lung disease with no effective therapy. In this study, we evaluated the effects of fluorofenidone (FD), a novel pyridone agent, on a murine model of bleomycin-induced pulmonary inflammation and fibrosis. Institute for Cancer Research mice were intravenously injected with BLM or saline for 14 consecutive days. Fluorofenidone, pirfenidone (500 mg · kg · d, respectively), or vehicle was administered throughout the course of the experiment. Animals were killed on day 28, and various parameters reflecting pulmonary vascular permeability, influx of inflammatory cells, and levels of transforming growth factor β in the bronchoalveolar lavage fluid were assessed. Collagen I, α-smooth muscle actin, and fibronectin were measured by real-time reverse transcriptase-polymerase chain reaction or Western blot. Furthermore, caveolin 1 and activation of P38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase were detected by Western blot. Fluorofenidone treatment significantly attenuated the increased pulmonary damage index score, the levels of proteins, transforming growth factor β, and the influx of cells in bronchoalveolar lavage fluid. Fluorofenidone also markedly reduced the expression of fibronectin, α-smooth muscle actin, and collagen I in mouse lung tissues. Inversely, FD restored caveolin 1 protein and mRNA expression, which was significantly downregulated in BLM-induced lung fibrosis. Fluorofenidone also inhibited phosphorylation of extracellular signal-regulated kinase, P38, and c-Jun N-terminal kinase. These findings collectively suggest that FD is an effective agent with antifibrotic and anti-inflammatory properties, and the mechanisms of its antifibrotic effect include regulating caveolin 1 expression and blocking mitogen-activated protein kinase signaling pathways.

Background Fluorofenidone (AKF-PD) is a novel pyridone agent. The purpose of this study is to investigate the inhibitory effects of AKF-PD on dimethylnitrosamine (DMN)-induced liver fibrosis in rats and the involved molecular mechanism related to hepatic stellate cells (HSCs). Materials and methods Wistar rats were randomly divided into normal control, DMN, DMN/AKF-PD treatment and DMN/pirfenidone (PFD) treatment groups. AKF-PD and PFD treatments were, respectively, performed for two activated HSCs lines, rat CFSC-2G and human LX2. The cell proliferation was analysed by MTT. The expression of collagen I was determined by immunohistochemical staining and real-time RT-PCR. The expression of α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinases-1 (TIMP-1), extracellular signal regulated kinase (ERK1/2), p38 MAPK (p38), and c-Jun N-terminal kinase/stress-activated protein kinase (JNK) were also detected by real-time RT-PCR and/or Western blot. Results AKF-PD significantly reduced PDGF-BB-induced proliferation and activation of HSCs, as determined by reducing protein expression of α-SMA and TIMP-1. AKF-PD treatment attenuated PDGF-BB-induced upregulation of phosphorylation of ERK1/2, p38 and JNK. In fibrotic rat liver, AKF-PD reduced the degree of liver injury and hepatic fibrosis, which was associated with reduced the expression of collagen I, α-SMA, TIMP-1 at both mRNA and protein levels. Conclusion AKF-PD treatment inhibits the progression of hepatic fibrosis by suppressing HSCs proliferation and activation via MAPK signalling pathway.

Glucagon-like peptide 1 (GLP-1) increases tissue glucose uptake and causes vasodilation independent of insulin. We examined the effect of GLP-1 on muscle microvasculature and glucose uptake. After confirming that GLP-1 potently stimulates nitric oxide (NO) synthase (NOS) phosphorylation in endothelial cells, overnight-fasted adult male rats received continuous GLP-1 infusion (30 pmol/kg/min) for 2 h plus or minus NOS inhibition. Muscle microvascular blood volume (MBV), microvascular blood flow velocity (MFV), and microvascular blood flow (MBF) were determined. Additional rats received GLP-1 or saline for 30 min and muscle insulin clearance/uptake was determined. GLP-1 infusion acutely increased muscle MBV (P < 0.04) within 30 min without altering MFV or femoral blood flow. This effect persisted throughout the 120-min infusion period, leading to a greater than twofold increase in muscle MBF (P < 0.02). These changes were paralleled with increases in plasma NO levels, muscle interstitial oxygen saturation, hind leg glucose extraction, and muscle insulin clearance/uptake. NOS inhibition blocked GLP-1–mediated increases in muscle MBV, glucose disposal, NO production, and muscle insulin clearance/uptake. In conclusion, GLP-1 acutely recruits microvasculature and increases basal glucose uptake in muscle via a NO-dependent mechanism. Thus, GLP-1 may afford potential to improve muscle insulin action by expanding microvascular endothelial surface area.

Chronic kidney disease (CKD) is a prevalent life-threatening disease frequently associated with hypertension, progression to renal fibrosis, and eventual renal failure. Although the pathogenesis of CKD remains largely unknown, an increased inflammatory response is known to be associated with the disease and has long been speculated to contribute to disease development. However, the causative factors, the exact role of the increased inflammatory cascade in CKD, and the underlying mechanisms for its progression remain unidentified. Here we report that interleukin 6 (IL-6) expression levels were significantly increased in the kidneys collected from CKD patients and further elevated in CKD patients characterized with hypertension. Functionally, we determined that angiotensin II is a causative factor responsible for IL-6 induction in the mouse kidney and that genetic deletion of IL-6 significantly reduced hypertension and key features of CKD, including renal injury and progression to renal fibrosis in angiotensin II–infused mice. Mechanistically, we provide both human and mouse evidence that IL-6 is a key cytokine functioning downstream of angiotensin II signaling to directly induce fibrotic gene expression and preproendothelin 1 mRNA expression in the kidney. Overall, both the mouse and human studies reported here provide evidence that angiotensin II induces IL-6 production in the kidney, and that, in addition to its role in hypertension, increased IL-6 may play an important pathogenic role in CKD by inducing fibrotic gene expression and ET-1 gene expression. These findings immediately suggest that the IL-6 signaling is a novel therapeutic target to manage this devastating disorder affecting millions worldwide.

To determine the expression and effect of hypoxia-inducible factor 1alpha (HIF-1alpha) in chronic kidney fibrosis, and to observe the effect of perindopril on its expression.The rat models of chronic kidney fibrosis were induced by 5/6 nephrectomy, and 11 successful 5/6-nephrectomized rats were randomly assigned to 2 groups: a surgery group (n=6) and a treatment group (perindopril, n=5). A control group was induced by sham operation. Five weeks later, Picro-Sirius red stained was applied to measure collagen in the kidney, and Western blot was used to test HIF-1alpha protein; The expression of HIF-1alpha and CTGF mRNA in the kidney was analyzed by real-time PCR.Picro-Sirius red stained revealed significant accumulation of collagens in the surgery group than the control group; and lower accumulation of collagens in the treatment group than the surgery group. Western blot showed higher deposit HIF-1alpha in the surgery group than the control group (P0.01) and lower deposit HIF-1alpha in the treatment group than the surgery group (P0.01). Real time PCR showed higher expression of HIF-1alpha and CTGF mRNA in the surgery group than the control group (P0.01)and lower expression of HIF-1alpha and CTGF mRNA in kidney of the treatment group compared with the surgery group (P0.01). The expression of CTGF had positive correlation with HIF-1alpha (r=0.68, P0.01).The HIF-1alpha may induce kidney fibrosis through CTGF. Perindopril may decrease the expression of HIF-1alpha and CTGF to ameliorate kidney fibrosis.

To dynamically observe the effect of enalapril on the expression of transforming growth factor beta1 (TGF-beta1), connective tissue growth factor (CTGF), alpha-smooth muscle actin (alpha-SMA), and Smad7 in the obstructed kidney after unilateral ureteral obstruction (UUO) in rats, and to investigate the effect of enalapril on transdifferentiation of renal tubular epithelial cells.The model rats were induced by ligating the left ureter. Male Sprague-Dawley (SD) rats were divided into a normal control (sham-surgery) group, a model group, and a treatment group (enalapril 10 mg/ (kg * d) by gastric gavage from 24 h before the obstruction day). Rats were sacrificed on day 3, 7, 14, 21 after UUO was initiated. Sections of the renal tissue were stained with hematoxylin and eosin stain, which were used for histological and morphometric studies of the pathological change of the obstructed kidney. Real-time PCR was performed to examine the expression of TGF-beta1 mRNA and CTGF mRNA, and Western blot was performed to examine the expression of Smad7, alpha-SMA, and CTGF in the obstructed kidney.The score of renal interstitial lesion increased with the extension of obstruction. The expression of TGF-beta1 mRNA, CTGF mRNA, alpha-SMA and CTGF increased in the model group with the extension of obstruction; but Smad7 expression decreased. Compared with the UUO group,the degree of renal interstitial lesion and the expression of TGF-beta1 mRNA, CTGF mRNA, alpha-SMA and CTGF were decreased, but the expression of Smad7 increased in the treatment group. Enalapril could significantly decrease TGF-beta1 mRNA on day 3, 7, 14, 21 after UUO. Enalapril could significantly affect the expression of CTGF mRNA,alpha-SMA,CTGF and Smad7 on day 3, 7, 14 after UUO initiation.Enalapril significantly alleviates renal interstitial fibrosis by suppressing the expression of TGF-beta1, CTGF and alpha-SMA, upregulating the expression of Smad7, and has better effect at early stage (within 14 days after the UUO).

Diabetic nephropathy (DN) remains the leading cause of end-stage renal disease (ESRD), a situation that is in part attributable to the lack of effective treatments. Fluorofenidone is a newly developed reagent with anti-fibrotic activity. While fluorofenidone was previously demonstrated to possess renoprotection from DN pathogenesis in db/db mice, the protective process and its underlying mechanisms have not been well studied. To characterize fluorofenidone-derived renoprotection, we treated 5, 8, or 12-week old db/db mice with daily doses of placebo, fluorofenidone, or losartan until 24 weeks of age; the time at which diabetes and DN were fully developed in placebo-treated animals. In comparison to db/db mice receiving fluorofenidone at 12-weeks old, those treated at 5-weeks had less glomerular expansion and better preservation of renal functions, judged by serum creatinine levels, albumin to creatinine ratio, and urinary albumin excretion (mg/24 hours). These benefits of early treatment were associated with significant reductions of multiple DN-promoting events, such as decreased expression of TGF-β1 and the p22phox subunit of NADPH oxidase as well as downregulated activation of protein kinase C-zeta (ζ), ERK and AKT. This improvement in renoprotection following early interventions is not a unique property of DN pathogenesis, as losartan does not apparently offer the same benefits and is not more renoprotective than fluorofenidone. Additionally, the enhanced renoprotection provided by fluorofenidone did not affect the diabetic process, as it did not alter serum levels of glycated serum proteins, glucose, triglyceride or cholesterol. Collectively, we provide evidence that fluorofenidone offers improved renoprotection at early stages of DN pathogenesis.

Loss of IQGAP2 contributes to the tumorigenesis of hepatocellular carcinoma and gastric cancer. However, whether IQGAP2 also suppresses prostate tumorigenesis remains unclear. We report here that IQGAP2 is a candidate tumour suppressor of prostate cancer (PC). Elevated IQGAP2 was detected in prostatic intraepithelial neoplasia (PIN), early stages of PCs (Gleason score ≤3), and androgen-dependent LNCaP PC cells. However, IQGAP2 was expressed at substantially reduced levels not only in prostate glands and non-tumorigenic BPH-1 prostate epithelial cells but also in advanced (Gleason score 4 or 5) and androgen-independent PCs. Furthermore, xenograft tumours that were derived from stem-like DU145 cells displayed advanced features and lower levels of IQGAP2 in comparison to xenograft tumours that were produced from non stem-like DU145 cells. Collectively, these results suggest that IQGAP2 functions in the surveillance of prostate tumorigenesis. Consistent with this concept, ectopic IQGAP2 reduced the proliferation of DU145, PC3, and 293T cells as well as the invasion ability of DU145 cells. While ectopic IQGAP2 up-regulated E-cadherin in DU145 and PC3 cells, knockdown of IQGAP2 reduced E-cadherin expression. In primary PC and DU145 cells-derived xenograft tumours, the majority of tumours with high levels of IQGAP2 were strongly-positive for E-cadherin. Therefore, IQGAP2 may suppress PC tumorigenesis, at least in part, by up-regulation of E-cadherin. Mechanistically, overexpression of IQGAP2 significantly reduced AKT activation in DU145 cells and inhibition of AKT activation upregulated E-cadherin, suggesting that IQGAP2 increases E-cadherin expression by inhibiting AKT activation. Taken together, we demonstrate here that IQGAP2 is a candidate tumour suppressor of PC.