Hyperuricemic Nephropathy Research Articles

Oxyberberrubine, a novel liver microsomes-mediated secondary metabolite of berberine, alleviates hyperuricemic nephropathy in mice

BackgroundBerberrubine (BRB), one of the major metabolites of berberine (BBR), exerts an anti-hyperuricemic effect even superior to BBR. Liver is an important location for drug transformation. Nevertheless, there are few studies on the bioactivities and metabolites of BRB. PurposeWe investigated whether oxyberberrubine (OBR), a liver metabolite of BRB, exerted urate-lowering and reno-protective effects in hyperuricemic mice. MethodsLiver microsomes were used to incubate BRB for studying its biotransformation. We isolated and identified its new metabolite OBR, and investigated its anti-hyperuricemic and reno-protective effects. In this work, the hyperuricemic mice model was established by receiving potassium oxonate (PO) and hypoxanthine (HX) for 7 consecutive days. 1 h after modeling, different dosages of OBR (5, 10 and 20 mg/kg), BRB (20 mg/kg) or febuxostat (Fex, 5 mg/kg) were given mice by gavage. ResultsResults showed that OBR possessed potent anti-hyperuricemic and reno-protective effects in hyperuricemic mice. Serum uric acid (UA) level was lowered, and the activities of xanthine oxidase (XOD) as well as adenosine deaminase (ADA) in the liver were suppressed after treatment with OBR. Hepatic expressions of XOD were remarkably decreased at mRNA and protein levels by OBR treatment. In addition, OBR prominently alleviated renal injury, embodied in markedly reduced serum creatinine and blood urea nitrogen (BUN) levels, decreased inflammatory mediators (TNF-α, IL-1β, IL-6 and IL-18) levels, mRNA expression of CYP27B1 and repairment of renal tissues damage. Besides, OBR down-regulated renal expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), and caspase-1 at mRNA and protein levels. ConclusionsIn short, our study indicated that OBR possessed superior anti-hyperuricemic and reno-protective effects, at least in part, through the inhibition of XOD, URAT1, GLUT9 and NLRP3 inflammasome signaling pathway in the kidney.

Simiao pill inhibits epithelial mesenchymal transition in a mouse model of chronic hyperuricemic nephropathy by inhibiting NLRP3 inflammasome activation

BackgroundSimiao pill module (SMM), a traditional Chinese medicine formula, has been widely used to treat gout and gouty arthritis. The goal of this study was to investigate the effects of SMM on epithelial-mesenchymal transition (EMT) and activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome in a mouse model of potassium oxonate (PO)-induced chronic hyperuricemic nephropathy (HN).MethodsMice were randomly divided into the following four groups: control, HN model (PO), febuxostat (FEB)-treated (PO + FEB), and SMM-treated (PO + SMM) groups. Following 6 weeks of treatment, blood samples were collected and mice were sacrificed to collect kidney samples to study the biochemical parameters associated with renal function and histopathological changes associated with HN, respectively. The samples were analyzed for the expression of markers of EMT (collagen type 3, α-smooth muscle actin [α-SMA], fibronectin, vimentin and E-cadherin) and activation of NLRP3 inflammasome (NLRP3, apoptosis-associated speck-like protein [ASC], caspase-1, interleukin [IL]-1β, and IL-18).ResultsOur results showed that hyperuricemia, impaired kidney function, and renal pathological characteristics induced by PO treatment were improved following treatment with SMM and FEB. Additionally, treatment with SMM and FEB decreased the expression of vimentin, collagen 3, fibronectin, and α-SMA, and increased the expression of E-cadherin. Moreover, NLRP3 inflammasome activation, as assessed by the increased expression of NLRP3, ASC, and caspase-1, and secretion of IL-1β and IL-18, was inhibited by treatment with SMM and FEB.ConclusionThese results suggest that SMM inhibited EMT and NLRP3 inflammasome activation in chronic HN mice, and the beneficial effect of SMM was compared with a standard drug, FEB.

Fibroblast growth factor 21 attenuates the progression of hyperuricemic nephropathy through inhibiting inflammation, fibrosis and oxidative stress.

Elevated levels of circulating fibroblast growth factor 21 (FGF21) have been reported in patients with hyperuricemia. However, the effect of FGF21 in hyperuricemic nephropathy (HN) remains unexplored. Here, we investigated the effect and mechanism of action of FGF21 on HN. HN model was induced with adenine and potassium oxysalt in wild-type C57BL/6 mice and FGF21-/- mice. For in vitro studies, human renal tubular epithelial (HK-2) cells were exposed to uric acid with/without FGF21 or β-Klotho-siRNA. Here, we reported aggravated renal dysfunction and structural damage in the FGF21-/- mice compared to the wild-type mice. These were evident in the upsurge of inflammatory factors IL-1β, TNF-α, IL-6, and IL-18; fibrotic markers Collagen I and α-SMA; and oxidation products ROS and MDA. However, exogenous administration of FGF21 to wild-type HN mice significantly reversed these negative effects. In terms of mechanism, FGF21 significantly inhibited NF-κB/NLRP3 and TGF-β1/Smad3 pathways and promoted nuclear translocation of Nrf2 both in vivo and in vitro. Furthermore, the silencing of β-Klotho was marked by the attenuation of the improved effect of FGF21 on cell damage. In conclusion, our studies revealed that exogenous FGF21 treatment significantly improved HN, which was achieved by the inhibition of inflammation, fibrosis, and oxidative stress.

AMP-activated protein kinase α2 contributes to acute and chronic hyperuricemic nephropathy via renal urate deposition in a mouse model

Hyperuricemia can induce acute and chronic kidney damage, but the pathological mechanism remains unclear. The potential role of AMP-activated protein kinase (AMPK) α2 in hyperuricemia-induced renal injury was investigated in this study. Acute and chronic hyperuricemic nephropathy was induced by administering intraperitoneal injections of uric acid and oxonic acid to AMPK α2 knockout and wild-type mice. Changes in renal function, histopathology, inflammatory cell infiltration, renal interstitial fibrosis, and urate deposition were analyzed. In both acute and chronic hyperuricemic nephropathy mouse models, knockout of AMPK α2 significantly reduced serum creatinine levels and renal pathological changes. The tubular expression of kidney injury molecule-1 was also reduced in hyperuricemic nephropathy mice deficient in AMPK α2. In addition, knockout of AMPK α2 significantly suppressed the infiltration of renal macrophages and progression of renal interstitial fibrosis in mice with chronic hyperuricemic nephropathy. Knockout of AMPK α2 reduced renal urate crystal deposition, probably through increasing the expression of the uric acid transporter, multidrug resistance protein 4. In summary, AMPK α2 is involved in acute and chronic hyperuricemia-induced kidney injury and may be associated with increased urate crystal deposition in the kidney.

Integrating network pharmacology and pharmacological validation to explore the effect of Shi Wei Ru Xiang powder on suppressing hyperuricemia

Ethnopharmacological relevanceShi Wei Ru Xiang powder (SWR) is a traditional Tibetan medicinal formula with the effect of dispelling dampness and dispersing cold. In clinical practice, SWR is generally used for the treatment of hyperuricemia (HUA). However, its exact pharmacological mechanism remains unclear. Aims of the studyTo preliminarily elucidate the regulatory effects and possible mechanisms of SWR on hyperuricemia using network pharmacology and experimental validation. Materials and methodsA mouse model of hyperuricemia was used to evaluate the alleviating effect of SWR on hyperuricemia. The major components of SWR were acquired by UPLC-Q/TOF-MS. The potential molecular targets and associated signaling pathways were predicted through network pharmacology. The mechanism of action of SWR in ameliorating hyperuricemia was further investigated by pharmacological evaluation. ResultsMice with hyperuricemia and renal dysfunction were ameliorated by SWR. The 36 components of SWR included phenolic acids, terpenoids, alkaloids and flavonoids were identified. Network pharmacological analysis showed the involvement of the above compounds, and 115 targets were involved to treat hyperuricemia, involving multiple biological processes and different signaling pathways. Pharmacological experiments validated that SWR ameliorated hyperuricemic nephropathy in mice by modulating the mitogen-activated protein kinase (MAPK) signaling pathway, nuclear factor kappaB (NF-κB) signaling pathway and NOD-like receptor signaling pathway. ConclusionMAPK signaling pathway, NF-κB signaling pathway and NOD-like receptor signaling pathway play important roles in the therapeutic effects of SWR on hyperuricemia.

Fufang Zhenzhu Tiaozhi capsule ameliorates hyperuricemic nephropathy by inhibition of PI3K/AKT/NF-κB pathway

Ethnopharmacological relevanceExcessive serum uric acid (SUA) causes hyperuricemic nephropathy (HN), characterized by inflammatory infiltration and tubulointerstitial fibrosis. Most recently, we demonstrated that Fufang Zhenzhu Tiaozhi (FTZ) capsule attenuated diabetic nephropathy through inhibition of renal inflammation and fibrosis. However, whether FTZ ameliorates HN is still unclear. Aim of the studyTo determine the protective roles and mechanism of FTZ in mouse renal injury and fibrosis under hyperuricemic condition. Materials and methodsHN mice, induced by potassium oxonate and hypoxanthine, were administrated with 600 and 1200 mg/kg FTZ (intragastrically) daily for three weeks. SUA levels, renal functions and histological changes were analyzed. Western blotting, quantitative real-time PCR (q-PCR) and RNA sequencing were used to identify the roles and underlying mechanism of FTZ in HN mice. ResultsWe demonstrated that FTZ treatment mitigated renal injury in mice, as evidenced by the decrease in SUA, serum creatinine (SCr) and cystatin C (Cys C) levels, as well as improved renal histology. FTZ markedly attenuates inflammasome activation, collagen deposition and the imbalance of uric acid transporters. RNA-sequencing revealed a key mechanism involved in the protective effects on HN mice was related to PI3K/AKT/NF-κB pathway. Western blot also confirmed that FTZ diminished the phosphorylation of AKT and p65 in HN mice. ConclusionsFTZ prevents renal injury, inflammation and fibrosis in HN mice via promoting uric acid excretion and inhibiting PI3K/AKT/NF-κB signaling pathway.

Chlorogenic Acid Prevents Hyperuricemia Nephropathy via Regulating TMAO-Related Gut Microbes and Inhibiting the PI3K/AKT/mTOR Pathway.

Hyperuricemia is an independent hazard factor of renal injury and can induce renal fibrosis, promoting the development of chronic kidney disease (CKD). This study aimed to explore the probability of chlorogenic acid (CGA) as a potential substance for preventing hyperuricemia nephropathy (HN). Pretreatment with CGA downregulated SUA, BUN, and CR levels, relieved oxidative stress and inflammatory response, alleviated kidney fibrosis, and contributed to the prevention of HN. In the gut microbiota, Blautia, Enterococcus, and Faecalibaculum related to trimethylamine N-oxide (TMAO) synthesis were significantly increased in HN rats. In addition, it showed a significant increase in serum TMAO content in HN rats. However, CGA regulated the cascade response of the microbiota-TMAO signaling to reverse the increase of serum TMAO. CGA also decreased the protein expression of protein kinase B (AKT) phosphorylation, phosphatidylinositide 3-kinase (PI3K), and mammalian target of rapamycin (mTOR) by reducing the production of TMAO. CGA delayed kidney fibrosis in HN rats as evidenced by regulating the cascade response of the microbiota-TMAO-PI3K/AKT/mTOR signaling pathway. In summary, CGA can be an excellent candidate for HN prevention.

Traditional Chinese herbs and natural products in hyperuricemia-induced chronic kidney disease.

Hyperuricemia is a common biochemical disorder, which resulted from both excessive uric acid (UA) production and/or absolute or relative impairment of urinary UA excretion. Growing evidence has indicated that hyperuricemia is an independent risk factor for the development and progression of chronic kidney disease (CKD), causing hyperuricemia-induced CKD (hyperuricemic nephropathy, HN). The therapeutic strategy of HN is managing hyperuricemia and protecting kidney function. Adverse effects of commercial drugs make persistent treatment of HN challenging. Traditional Chinese medicine (TCM) has exact efficacy in lowering serum UA without serious adverse effects. In addition, TCM is widely applied for the treatment of CKD. This review aimed to provide an overview of efficacy and mechanisms of traditional Chinese herbs and natural products in hyperuricemia-induced CKD.

Febuxostat Improves Uric Acid Levels and Renal Function in Patients with Chronic Kidney Disease and Hyperuricemia: A Meta-Analysis.

Background Uric acid nephropathy, also known as hyperuricemia nephropathy or gouty nephropathy, is characterized by uric acid crystal deposition and inflammatory cell infiltration. Herein, we aimed to demonstrate the role of febuxostat on uric acid levels and renal function in patients with chronic kidney disease and hyperuricemia. Methods Eight databases included were searched for clinical randomized controlled trials. Meanwhile, the confidence interval (CI) of either relative risk or mean difference was set to 95%. Besides, the heterogeneity of the research results is tested by I2. Results Ten studies were ultimately included in this meta-analysis. All of them were considered to be random controlled trials. 10 studies reported the serum uric acid of the test group and the control group, which was significantly lower (SMD: -146.44, 95% Cl: -195.96, -86.93, and P < 0.01) than the control group, EGFR (SMD: 3.21, 95% Cl: 1.17, 5.25, and P < 0.01), serum creatinine (SMD: -15.27, 95% Cl: -20.75, -9.79, and P < 0.01), serum urea nitrogen (SMD: -2.37, 95% Cl: -3.31, -1.61, and P < 0.01), and adverse reactions (OR: 0.74, 95% Cl: 0.32, 1.68, and P = 0.47). Conclusion The results of this study suggest that febuxostat may be effective in patients with CKD with HUA, as evidenced by serum uric acid, creatinine, urea nitrogen, and EGFR. However, large sample, multicenter, low risk of bias clinical studies, as well as basic medical research, are needed.

Evaluation of renal microperfusion in hyperuricemic nephropathy by contrast-enhanced ultrasound imaging

ABSTRACTDiagnostic tools for the early detection of renal injury caused by hyperuricemia are still lacking. Here, we investigated whether contrast-enhanced ultrasound (CEUS) could be used as a diagnostic tool for hyperuricemic nephropathy (HN). In the HN rat model, CEUS detected a significant decline in renal cortical perfusion compared with that in control rats. Peak intensity (PI) values correlated significantly with serum KIM-1 levels and fibrosis scores in HN rats. An early decline in PI values was also observed in chronic kidney disease (CKD) stage 1 patients with HN compared with the controls (61.1±4.52 dB versus 65.80±7.10 dB) and correlated with renal function in the patients with HN. In contrast, an increase in time to reach PI values was detected in HN patients with stage 1 CKD (15.14±1.75 s versus 14.52±4.75 s) and was more pronounced in CKD stage 4 patients (67.32±3.29 s). CEUS was able to detect abnormal renal perfusion in early CKD with HN, which correlated with renal function decline, suggesting that CEUS could be used as a noninvasive tool for assessing renal function in patients with HN.

Urolithin A Attenuates Hyperuricemic Nephropathy in Fructose-Fed Mice by Impairing STING-NLRP3 Axis-Mediated Inflammatory Response via Restoration of Parkin-Dependent Mitophagy

Urolithin A (UroA) is one of the primary intestinal metabolites of ellagitannins, showing translational potential as a nutritional intervention in humans. Mounting evidence suggests that fructose consumption contributes to the progression of chronic kidney disease (CKD) that manifests in hyperuricemic nephropathy, renal inflammation, and tubulointerstitial injury. Here, we investigated the efficacy of UroA in alleviating fructose-induced hyperuricemic nephropathy in mice. Uric acid-exposed human kidney-2 (HK-2) cells were utilized for in vitro mechanism validation. Histopathological staining, immunoblotting, and transmission electron microscope were performed for the mechanistic investigations. Our results revealed that UroA ameliorated fructose-induced hyperuricemic nephropathy in mice. The histopathologic assessment showed that UroA attenuated tubular hypertrophy and dilation, glomerular basement membrane thickening, and collagen deposition in the kidney of fructose-fed mice. Mechanistically, UroA treatment impaired STING-NLRP3 activation, resulting in reduced production of proinflammatory cytokines IL-1β, IL-6, and TNF-α. Notably, UroA exhibited a scavenging effect against reactive oxygen species (ROS) and restored fructose-impaired PINK1/Parkin-mediated mitophagy in nephropathic mice. Furthermore, the inhibitory effect of UroA in STING-NLRP3 activation was impaired after Parkin gene silencing in HK-2 cells. Together, this study suggests that UroA alleviates fructose-induced hyperuricemic nephropathy by promoting Parkin-dependent mitophagy, thereby suppressing STING-NLRP3 axis-mediated inflammatory response. Thus, dietary supplementation with UroA or ellagitannins-rich foods may serve as a promising intervention to prevent CKD progression.

Beneficial herb-drug interaction of Gnaphalium affine extract on benzbromarone: A pharmacokinetic and pharmacodynamic study in rats

BackgroundGnaphalium affine D. Don extract (GAD) enhanced efficacy and reduced toxicity of benzbromarone (BBR) in combination use. However, little is known about effects of GAD on the pharmacokinetics (PKs) and metabolic enzymes of BBR. PurposeTo investigate the pharmacokinetic (PK) and pharmacodynamic (PD) mechanism of the herb-drug interactions (HDIs) between GAD and BBR. Study design and methodsIntragastric single BBR (4.5 or 50 mg/kg), single BBR (4.5 or 50 mg/kg) + single GAD (450 mg/kg, 2 h after BBR-administration), or single BBR (4.5 or 50 mg/kg) + multiple GAD (450 mg/kg/day, once daily for 7 days) were administered to both sexes for BBR PK studies in normal rats. Intragastric multiple BBR (4.5 mg/kg/day), or multiple BBR (4.5 mg/kg/day) + multiple GAD (450 mg/kg/day, 2 h after BBR-administration) were administered for BBR PK and PD studies in male rats with hyperuricemic nephropathy (HN). The cumulative anti-hyperuricemic effects of BBR and BBR+GAD were determined by plasma uric acid (UA) concentration-time curve and area under curve (AUCUA). An in vivo cocktail approach was employed to determine the effects of GAD on cytochrome P450 (CYP) 2C11(9) and 1A2 – mediated drug metabolism. ResultsIn normal rats, the repeated dose administration of GAD induced a significant increase of BBR AUC and prolonged the mean residence time (MRT) (p < 0.05). systemic exposure to BBR and metabolically derived hydroxybenzbromarones was significantly greater in female compared with male rats (p < 0.05). In HN rats, post-administration of GAD resulted in significantly higher bioavailability and enterohepatic recycling (ER) of BBR relative to the BBR alone administrated group from the prolongation of terminal elimination half-life (T1/2) and MRT of BBR (p < 0.05). Significantly higher urate-lowering effect of BBR+GAD compared with BBR alone was generally observed at post-dosing most time points with a maximal effect of 84.3% (acute treatment), 71.4% (7-day subchronic treatment) and 82.5% (14-day subchronic treatment) reduction in UA levels. Additionally, GAD showed a significant inhibitory effect on CYP2C11(9)-mediated tolbutamide (probe substrate) metabolism with ≥ 1.25 but < 2-fold increase in AUCtolbutamide. ConclusionsPD synergism demonstrated with the BBR+GAD combination could be explained by the PK interaction observed partially from CYP2C11(9)-mediation and enterohepatic recycling.

Blockade of Autophagy Prevents the Progression of Hyperuricemic Nephropathy Through Inhibiting NLRP3 Inflammasome-Mediated Pyroptosis.

Hyperuricemia has become a common metabolic disease, and is a risk factor for multiple diseases, including chronic kidney disease. Our recent study indicated that following persistent uric acid stimulation, autophagy was activated in rats of hyperuricemic nephropathy (HN) and facilitated the development of renal fibrosis. Nevertheless, the potential mechanism by which autophagy promoted the progression of HN is still not fully elucidated. Thus, in the current study, we investigated the mechanisms of autophagy inhibition on the development of HN. Our data showed that autophagy was activated in human renal tubular cell lines (HK-2) exposure to uric acid. Inhibition of autophagy with 3-methyladenine (3-MA) and transfected with Beclin-1 siRNA prevented uric acid-induced upregulation of α-SMA, Collagen I and Collagen III in HK-2 cells. Moreover, uric acid upregulated autophagy via promoting the p53 pathway. In vivo, we showed that hyperuricemic injury induced the activation of NLRP3 inflammasome and pyroptosis, as evidenced by cleavage of caspase-1 and caspase-11, activation of gasdermin D (GSDMD) and the release of IL-1β and IL-18. Treatment with autophagy inhibitor 3-MA alleviated aforementioned phenomenon. Stimulation with uric acid in HK-2 cells also resulted in NLRP3 inflammasome activation and pyroptotic cell death, however treatment with 3-MA prevented all these responses. Mechanistically, we showed that the elevation of autophagy and degradation of autophagolysosomes resulted in the release of cathepsin B (CTSB), which is related to the activation of NLRP3 inflammasome. CTSB siRNA can inhibit the activation of NLRP3 inflammasome and pyroptosis. Collectively, our results indicate that autophagy inhibition protects against HN through inhibiting NLRP3 inflammasome-mediated pyroptosis. What’s more, blockade the release of CTSB plays a crucial role in this process. Thus, inhibition of autophagy may be a promising therapeutic strategy for hyperuricemic nephropathy.

Hsp70 promotes maturation of uromodulin mutants that cause familial juvenile hyperuricemic nephropathy and suppresses cellular damage.

Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal dominant disorder caused by mutations in UMOD. Here we studied effects of genetic expression and pharmacological induction of Hsp70 on the UMOD mutants C112Y and C217G. We expressed wild type (WT), C112Y and C217G in HEK293 cells and studied their maturation and cellular damage using western blot and flow cytometry. Expression of C112Y or C217G increased pro-apoptotic proteins, decreased anti-apoptotic proteins, and induced cellular apoptosis as examined by annexin V staining and flow cytometry. Overexpression of Hsp70 or administration of an Hsp70 inducer geranylgeranylacetone (GGA) promoted maturation of the mutant proteins, increased their secreted forms, normalized the levels of pro- and anti-apoptotic proteins and suppressed apoptosis. These findings indicated that Hsp70 enhanced maturation of C112Y and C217G and reduced cellular apoptosis, suggesting that Hsp70 induction might be of a therapeutic value for treatment of FJHN.

POS-081 SERUM RESPONSE FACTOR, A NOVEL EARLY DIAGNOSTIC BIOMARKER OF ACUTE KIDNEY INJURY

Studies have shown that serum response factor (SRF) is increased in chronic kidney injury, such as diabetic nephropathy, hyperuricemic nephropathy and renal cell carcinoma. The objective is to explore the early diagnostic value of SRF in acute kidney injury (AKI). AKI-related microarray data were analyzed, and the expression and location of SRF were investigated in the early phase of AKI. ① The microarray analysis results of bilateral I/R mice There were 567 DEGs at 2 h and 857 DEGs at 4 h after I/R in GSE98622 (Figure 1A, 1B). SRF started to increase at 2 h-4 h and decreased to the basal level at 72 h after bilateral I/R in mice (Figure 1C), which suggested that SRF might be connected with AKI. Moreover, as shown in Figure 1C, SRF was increased again 7 d after I/R, which indicated that SRF might be a promising biomarker of the transformation from AKI to chronic kidney injury and post-AKI fibrosis. ② SRF was upregulated and localized in TECs in I/R rats As shown by IHC and IF, SRF was upregulated and located in TECs 6 h after I/R compared to the sham operation group and the control group (Figure 2). This result was consistent with the microarray data from I/R mice. ③ Scr level and renal SRF mRNA expression in I/R rats As shown in Figure 3A, the expression of SRF mRNA in the kidney changed 1 h, 3 h, 6 h, 9 h, 12 h, and 24 h after I/R. In other words, the SRF level in the kidney of the I/R rats started to increase after 3 h, reached its peak at 6-9 h and decreased at 12 h and 24 h. The fitting function estimated that the peak SRF level should be at 6 h. No significant variation in SRF was detected in the sham operation group (Figure 3A). Compared to the increase in SRF levels, the increase in Scr levels was obviously delayed. Scr started to increase after 24 h in the I/R group compared to the control group and the sham group (Figure 3B), indicating that SRF may be an earlier biomarker for AKI and may assist physicians in diagnosing AKI in a timelier manner. ④ The protein level of SRF in kidney, urine and serum in vivo SRF levels in the kidney increased at 1 h, reached its peak at 6 h and started to decline at 12 h after I/R (Figure 4A, 4B). SRF was dramatically increased in the serum of I/R rats at 1 h-6 h after I/R (Figure 4C). In urine, the expression of SRF in the I/R group was dramatically increased at 3 h, reached its peak at 6-9 h, and began to decrease at 12 h after I/R. Additionally, SRF levels were also increased postoperatively in the kidney, urine and serum of the sham rats, but the increases in the sham group were significantly less than those in the I/R group. ⑤ The ROC curve of renal SRF mRNA, renal SRF protein, urinary SRF, serum SRF and Scr in early (before 24 h) AKI To explore more sensitive and specific biomarkers to diagnose AKI, we used a ROC curve assay to investigate the cutoff value of renal SRF mRNA, renal SRF protein, urinary SRF, serum SRF, and Scr levels (Figure 5). The AUCs of SRF mRNA, SRF protein, urinary SRF and serum SRF were 87.9%, 83%, 81.3% and 78.8%, respectively, which were all better than that of Scr (68.8%), which indicated that urinary SRF could be an early diagnostic marker of AKI with better sensitivity and specificity than Scr. SRF is remarkably upregulated in early (before 24 h) AKI and can replace Scr as a potential new early diagnostic biomarker of AKI.

Natural Flavonoid Pectolinarigenin Alleviated Hyperuricemic Nephropathy via Suppressing TGFβ/SMAD3 and JAK2/STAT3 Signaling Pathways.

Natural flavonoid pectolinarigenin (PEC) was reported to alleviate tubulointerstitial fibrosis of unilateral ureteral obstruction (UUO) mice in our previous study. To further investigate nephroprotective effects of PEC in hyperuricemic nephropathy (HN), adenine and potassium oxonate induced HN mice and uric acid-treated mouse kidney epithelial (TCMK-1) cells were employed in the study. As a result, PEC significantly lowered serum uric acid level and restored hyperuricemia-related kidney injury in HN mice. Meanwhile, PEC alleviated inflammation, fibrosis, and reduced adipokine FABP4 content in the kidneys of HN mice and uric acid-treated TCMK-1 cells. Mechanistically, PEC inhibited the TGF-β1 expression as well as the phosphorylation of transcription factor SMAD3 and STAT3 to regulate the corresponding inflammatory and fibrotic gene expression in kidney tissues. In conclusion, our results suggested that PEC could inhibit the activation of SMAD3 and STAT3 signaling to suppress inflammation and fibrosis, and thereby alleviate HN in mice.

Fufang Zhenzhu Tiaozhi Capsule Ameliorates Hyperuricemic Nephropathy by Inhibition of PI3K/AKT/NF-Κb Pathway

Fufang Zhenzhu Tiaozhi Capsule Ameliorates Hyperuricemic Nephropathy by Inhibition of PI3K/AKT/NF-Κb Pathway

Methyl Gallate Improves Hyperuricemia Nephropathy Mice Through Inhibiting NLRP3 Pathway.

Hyperuricemia nephropathy (HN) is a form of chronic tubulointerstitial inflammation, caused by the deposition of monosodium urate crystals (MSU) in the distal collecting duct and medullary interstitium, associated with a secondary inflammatory reaction. Numerous published reports indicated that NLRP3 inflammasome pathway play crucial roles in HN symptoms. The present study aims to investigate the protective effects of methyl gallate on HN mice and the underlying mechanisms. An HN model was established by intraperitoneal injection of potassium oxide (PO) to assess the effect of methyl gallate on renal histopathological changes, renal function, cytokine levels and expressions of NLRP3-related protein in HN mice. Moreover, in vitro models of lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs) and human peripheral blood mononuclear cells (PBMCs) were established to explore the mechanism of methyl gallate on NLRP3 inflammasome activation. The results showed that methyl gallate significantly ameliorated HN by inhibiting uric acid production and promoting uric acid excretion as well as ameliorating renal injury induced by NLRP3 activation. Mechanistically, methyl gallate is a direct NLRP3 inhibitor that inhibits NLRP3 inflammasome activation but has no effect on the activation of AIM2 or NLRC4 inflammasomes in macrophages. Furthermore, methyl gallate inhibited the assembly of NLRP3 inflammasomes by blocking the ROS over-generation and oligomerization of NLRP3. Methyl gallate was also active ex vivo against ATP-treated PBMCs and synovial fluid mononuclear cells from patients with gout. In conclusion, methyl gallate has a nephroprotective effect against PO-induced HN through blocking the oligomerization of NLRP3 and then exerting anti-inflammatory activity in the NLRP3-driven diseases.

Zishen Qingre Tongluo Formula Improves Renal Fatty Acid Oxidation and Alleviated Fibrosis via the Regulation of the TGF-β1/Smad3 Signaling Pathway in Hyperuricemic Nephrology Rats.

Hyperuricemia, an independent risk factor for ensuing chronic kidney disease (CKD), contributed to tubulointerstitial fibrosis and insufficiency of renal fatty acid oxidation. Many studies have shown that renal fatty acid oxidation dysfunction is related to the TGF-β1/Smad3 signaling pathway. We experimented the effects of Zishen Qingre Tongluo Formula (ZQTF) on the adenine/yeast-induced HN rats and uric acid-induced renal mouse tubular epithelial cells (mTECs), determined whether this effect was related to the TGF-β1/Smad3 signaling pathway, and further investigated the relationship between this effect and renal fatty acid oxidation. Rats were given intraperitoneally with adenine (100 mg/kg) and feed chow with 10% yeast for 18 days and then received ZQTF (12.04 g/kg/day) via intragastric gavage for eight weeks. The TGF-β1/Smad3 signaling pathway and renal fatty acid oxidation protein were detected by using western blotting, real-time PCR, and immunohistochemistry staining. mTECs induced by UA were used to investigate the relationship between the TGF-β1/Smad3 signaling pathway and renal fatty acid oxidation. After treatment with ZQTF, levels of UA, 24 h UTP, BUN, and Scr were significantly decreased and histologic injuries were visibly ameliorated in HN rats. Western blotting, real-time PCR, and immunohistochemistry staining revealed that PGC-1α, PPARγ, and PPARα significantly increased, and fibronectin, collagen 1, and P-Smad3 significantly decreased in HN rats and UA-induced mTECs after ZQTF treatment. SIS3 (a specific inhibitor of Smad3) treatment significantly increased the expressions of PGC-1α, PPARγ, and PPARα and decreased the expressions of fibronectin, collagen 1, and P-Smad3 in UA-induced mTECs. Our study demonstrated that ZQTF exhibited renoprotective effects by promoting renal fatty acid oxidation via the regulation of the TGF-β1/Smad3 signaling pathway. Thus, the present results indicated that ZQTF was a novel antifibrotic strategy for hyperuricemic nephropathy.

Enhanced Efficacy and Reduced Hepatotoxicity by Combination of Gnaphalium affine Extract and Benzbromarone in the Treatment of Rats with Hyperuricemic Nephropathy

Simultaneous oral intake of herbal medicine with chemical drugs may result in beneficial pharmacodynamic efficacy, including additive and synergistic effects with reduced toxicity. Gnaphalium affine D. Don (GAD) is a traditional Chinese Medicine that has been used for the management of hyperuricemia and gout. Benzbromarone (BBR) is one of the first-line drugs used for urate-lowering therapy in China but is toxic to the liver. The present study aimed to determine the effects of GAD and BBR, both alone and in co-treatment (with dosing interval of 1 hour), on chronic hyperuricemic nephropathy (HN) and hepatotoxicity in rats. Our data indicated that GAD significantly inhibited the elevation of serum uric acid, blood urea nitrogen, and creatinine levels in chronic HN rats at doses of 450 and 900 mg/kg/day. The rise in serum alanine aminotransferase and aspartate aminotransferase in BBR (or vehicle)-treated HN rats was significantly reduced by pre- (or post)-administration of GAD (450 mg/kg/day). The q-value &gt;1.15 (by Jin method) indicated synergistic effects of co-treatments of BBR (50 mg/kg) with GAD (450 mg/kg). The synergistic beneficial effects were validated by comparison of BBR alone at a dose of clinical usage (4.5 mg/kg/day, in two divided doses) and BBR + GAD at half dose plus half dose (2.25 + 225 mg/kg/day) or half dose plus full dose (2.25 + 450 mg/kg/day). In conclusion, co-treatment with GAD and BBR holds promise for the management of hyperuricemia and gout.