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Renal fibrosis is the common endpoint of nearly all chronic and progressive nephropathies. Cell death and sterile inflammation are the main characteristics of renal fibrosis, which can lead to end-stage renal failure. The inflammatory reaction triggered by tissue damage is strongly related to necroptosis, a type of caspase-independent, regulated cell death. Using an animal model of unilateral ureteral obstruction (UUO), the anti-fibrotic effects of sorafenib (SOF), a multi-kinase inhibitor, and edaravone (EDV), a potent antioxidant and free radical scavenger, were examined in rats with obstructive nephropathy. Experimentally, animals were divided randomly into five groups: sham; UUO; UUO + SOF (5 mg/kg/day, P.O.); UUO + EDV (20 mg/kg/day, P.O.); and UUO + SOF + EDV groups. The kidney function biomarkers, oxidant/antioxidant status, renal mRNA expressions of TNF-α, collagen-1α, protein expressions of RIPK-1, RIPK-3, MLKL, caspase-8, HYP, MPO, and TNF-α were all significantly modulated by UUO. Administration of either SOF or EDV significantly attenuated cellular and molecular changes induced by UUO. Also, histopathological changes were improved. Moreover, SOF in combination with EDV, significantly improved UUO-induced renal fibrosis compared with each drug alone. Collectively, administration of either SOF or EDV or both of them significantly attenuated the rats with obstructive nephropathy, possibly by blocking the RIPK-3/MLKL necroptotic pathway and suppressing renal oxidative stress and inflammation. [ABSTRACT FROM AUTHOR]

Iguratimod is a novel synthetic, small-molecule immunosuppressive agent used to treat rheumatoid arthritis. Through ongoing exploration of its role and mechanisms of action, iguratimod has been observed to have antifibrotic effects in the lung and skin; however, its effect on renal fibrosis remains unknown. This study aimed to investigate whether iguratimod could affect renal fibrosis progression. Three different concentrations of iguratimod (30 mg/kg/day, 10 mg/kg/day, and 3 mg/kg/day) were used to intervene in unilateral ureteral obstruction (UUO) model mice. Iguratimod at 10 mg/kg/day was observed to be effective in slowing UUO-mediated renal fibrosis. In addition, stimulating bone marrow-derived macrophages with IL-4 and/or iguratimod, or with TGF-β and iguratimod or SRC inhibitors in vitro, suggested that iguratimod mitigates the progression of renal fibrosis in UUO mice, at least in part, by inhibiting the IL-4/STAT6 signaling pathway to attenuate renal M2 macrophage infiltration, as well as by impeding SRC activation to reduce macrophage–myofibroblast transition. These findings reveal the potential of iguratimod as a treatment for renal disease. [ABSTRACT FROM AUTHOR]

Abstract Obstructed urine flow is known to cause structural and functional kidney damage leading to renal fibrosis. However, limited information is available on the change in kidney lipids during urinary tract obstruction. In this study, we investigated the change in lipidome in a mouse model with unilateral ureteral obstruction (UUO). The establishment of the UUO model was confirmed by histopathological examination using transmission electron microscopy. Untargeted liquid chromatography/mass spectrometry was carried out over a time course of 4 and 7 days. Compared to the sham control, the UUO kidney at 7 days showed dilatation of the renal tubule with loss of brush borders and thickening of the capillary endothelium. In the kidney lipidomes obtained from the UUO 7 days group compared to the control, a significant decrease of ceramide, sphingomyelin, phosphatidylcholine, lysophospholipids, and phosphatidylethanolamine was observed, whereas cholesteryl esters, free fatty acids, phosphatidylglycerol, and cardiolipins were significantly increased. The present study revealed the disturbed lipid metabolism in the UUO model, which may provide a clue to potential lipid pathways and therapeutic targets for the early stage of renal fibrosis.

Abstract Introduction Inflammatory and immunological responses are reported involved in the pathogenesis and progression of obstructive nephropathy (ON). This study was designed to investigate the characteristics of peripheral immunity in patients with upper urinary tract urolithiasis and analyze the underlying associations with renal function. Methods Patients with unilateral upper urinary tract urolithiasis meeting the operation indications were prospectively enrolled. Preoperative circulating immune cells and inflammatory cytokines were detected in our clinical laboratory, and the indicators of renal function and calculi related parameters were particularly recorded. Patients were sectionalized into subgroups on the basis of the lesion of calculi. Characteristics of peripheral immunity in each subgroup were investigated by statistical approaches, and the underlying correlations with the degree of hydronephrosis (HN) and renal function were discussed in corresponding group. Results Patients with ureteral calculi presented severer HN compared with renal calculi, especial middle ureteral calculi, acting as the chief culprit of ON, exhibiting the highest serum creatine and blood urea nitrogen, most impaired estimated glomerular filtration rate, and severest HN. In addition, serum interleukin-8 (IL-8) and IL-6 were demonstrated presenting statistical differences between ureteral calculi and renal calculi patients, exhibiting underlying values in comprehending ON. However, circulating immune cells were demonstrated no obvious differences among groups. Conclusions Circulating inflammatory cytokines, referred in particular to serum IL-8 and IL-6 were partially associated with kidney injury in patients with upper urinary tract urolithiasis. But the specific influences and mechanisms between them needed to be investigated furthermore.

Objective: To investigate the effects of ginkgo biloba extract (GBE) on renal fibrosis in mice with unilateral ureteral obstruction (UUO) by regulating transforming growth factor-β1 (TGF-β1)/ hepatocyte growth factor (HGF) signaling pathway. Methods:The UUO mouse model was constructed by unilateral ureteral ligation, the mice were randomly divided into model group, irbesartan group (20 mg/kg), GBE low, medium and high dose groups (25 mg/kg, 50 mg/kg, 100 mg/kg) after successful modeling, with 10 mice in each group. Another 10 mice were taken as sham operation group (only the left ureter was separated but not ligated). Renal function indexes: β-N-acetylglucosaminidase (NAG), creatinine (Scr), urea nitrogen (BUN) were detected; The levels of serum tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). The pathological changes of renal tissue were observed by hematoxylin-eosin (HE) staining. The fibrosis of renal tissue were observed by masson (Masson) staining.The expressions of α-smooth muscle actin (α-SMA) and TGF-β1 were detected by immunohistochemistry. The expression of type I collagen (Col-I), α-SMA, TGF-β1, cell signal transduction molecule 2 (Smad2), phosphorylated Smad2 (p-Smad2) and HGF protein in renal tissue were detected by Western blot. Results: Compared with sham operation group, the renal tubular lumen in model group was dilated or atrophied, inflammatory cell infiltration, collagen fiber deposition was obvious, NAG, Scr, BUN, TNF-α, IL-1β, IL-6, renal fibrosis level, Col-I, α-SMA, TGF-β1, p-Smad2/Smad2 expression were significantly increased, and HGF protein expression was significantly decreased (P＜0.05). Compared with model group, the pathological damage of renal tissue in irbesartan group and GBE low, medium and high dose groups was reduced, the collagen deposition fibers were reduced, NAG, Scr, BUN, TNF-α, IL-1β, IL-6, renal fibrosis level,Col-I, α-SMA, TGF-β1, p-Smad2/Smad2 expression were significantly decreased, and HGF protein expression was significantly increased (P＜0.05), among which irbesartan group and EG high dose group improved most significantly. Conclusion: GBE can reduce renal function damage, inhibit inflammatory response, and improve renal fibrosis in UUO mice, the mechanism may be relate to regulating the balance of TGF-β1/HGF signaling pathway. [ABSTRACT FROM AUTHOR]

Introduction: Inflammatory and immunological responses are reported involved in the pathogenesis and progression of obstructive nephropathy (ON). This study was designed to investigate the characteristics of peripheral immunity in patients with upper urinary tract urolithiasis and analyze the underlying associations with renal function. Methods: Patients with unilateral upper urinary tract urolithiasis meeting the operation indications were prospectively enrolled. Preoperative circulating immune cells and inflammatory cytokines were detected in our clinical laboratory, and the indicators of renal function and calculi related parameters were particularly recorded. Patients were sectionalized into subgroups on the basis of the lesion of calculi. Characteristics of peripheral immunity in each subgroup were investigated by statistical approaches, and the underlying correlations with the degree of hydronephrosis (HN) and renal function were discussed in corresponding group. Results: Patients with ureteral calculi presented severer HN compared with renal calculi, especial middle ureteral calculi, acting as the chief culprit of ON, exhibiting the highest serum creatine and blood urea nitrogen, most impaired estimated glomerular filtration rate, and severest HN. In addition, serum interleukin-8 (IL-8) and IL-6 were demonstrated presenting statistical differences between ureteral calculi and renal calculi patients, exhibiting underlying values in comprehending ON. However, circulating immune cells were demonstrated no obvious differences among groups. Conclusions: Circulating inflammatory cytokines, referred in particular to serum IL-8 and IL-6 were partially associated with kidney injury in patients with upper urinary tract urolithiasis. But the specific influences and mechanisms between them needed to be investigated furthermore. [ABSTRACT FROM AUTHOR]

Obstructed urine flow is known to cause structural and functional kidney damage leading to renal fibrosis. However, limited information is available on the change in kidney lipids during urinary tract obstruction. In this study, we investigated the change in lipidome in a mouse model with unilateral ureteral obstruction (UUO). The establishment of the UUO model was confirmed by histopathological examination using transmission electron microscopy. Untargeted liquid chromatography/mass spectrometry was carried out over a time course of 4 and 7 days. Compared to the sham control, the UUO kidney at 7 days showed dilatation of the renal tubule with loss of brush borders and thickening of the capillary endothelium. In the kidney lipidomes obtained from the UUO 7 days group compared to the control, a significant decrease of ceramide, sphingomyelin, phosphatidylcholine, lysophospholipids, and phosphatidylethanolamine was observed, whereas cholesteryl esters, free fatty acids, phosphatidylglycerol, and cardiolipins were significantly increased. The present study revealed the disturbed lipid metabolism in the UUO model, which may provide a clue to potential lipid pathways and therapeutic targets for the early stage of renal fibrosis. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) affects the morphological structure and causes significant degradation in kidney function, leading to renal replacement treatment in affected individuals. Vascular rarefaction is thought to be an important factor in accelerating kidney damage in CKD patients, therefore, the assessment of renal morphology and vasculature is crucial in nephrology. The objective of this study was to evaluate the morphological and vascular changes caused by CKD in mice kidneys. In this study, dual photoacoustic microscopy (PAM) and optical coherence microscopy (OCM) oriented wide-field high-resolution imaging modalities were employed for diseased renal imaging. The unilateral ureteral obstruction (UUO) model was used to prepare renal samples with CKD, and the developed wide-field dual imaging system was used to image both control and CKD-affected kidneys for assessing vascular and morphological changes during CKD progression. The obtained results reveal a gradual alteration in vascular intensity and pelvis space with the progress of UUO disease. Furthermore, a quantitative micro-vessel analysis was performed based on the node, junction, and mesh of the vessel, which provides details on the increasing microvascular-related characteristics in the peripheral area as the disease progresses. Thus, by concurrently employing the advantages of each optical imaging technique, the proposed method of assessing the OCM-based morphological and PAM-based vascular properties of the renal sample using a wide-field multimodal imaging system can be an efficient technique for whole volume analysis without any exogenous contrast agents in kidney histopathology. [ABSTRACT FROM AUTHOR]

Objectives: Erythropoietin (EPO) exerts tissue‐protective effects on various organs including the kidney. However, the effects of EPO on established renal fibrosis remain unclear. In this study, we aimed to examine the therapeutic potential of EPO against established renal fibrosis. Methods: Renal fibrosis was induced in mice by unilateral ureteral obstruction (UUO) and the mice were treated with recombinant human EPO (rhEPO) daily during 7 and 13 days after UUO. The degrees of renal fibrosis, myofibroblast accumulation, and macrophage infiltration; the mRNA expression levels of transforming growth factor (TGF)‐β1 and α1(I) collagen; and the protein levels of Kelch‐like ECH‐associated protein 1 (Keap1) and nuclear NF‐E2‐related factor 2 (Nrf2) in the kidneys were assessed on day 14 after UUO. Results: Treatment with rhEPO significantly decreased fibrosis, myofibroblast accumulation, and α1(I) collagen mRNA expression, but it did not significantly affect TGF‐β1 mRNA expression. Although treatment with rhEPO did not significantly affect the total number of interstitial macrophages, it significantly decreased the number of CD86‐positive cells (M1 macrophages), while significantly increased the number of CD206‐positive cells (M2 macrophages) in the interstitium. Treatment with rhEPO did not affect the Keap1/Nrf2 protein level or the peripheral blood hematocrit value. Conclusions: These results indicate for the first time that EPO exerts antifibrotic effects against the evolution of established renal fibrosis, possibly by influencing the polarization of infiltrating macrophages. [ABSTRACT FROM AUTHOR]

Renal fibrosis plays a significant role in the development of chronic kidney disease (CKD). Therefore, treatment of renal fibrosis is essential in reducing the incidence of CKD-related problems. Due to their function as anti-inflammatory and antioxidant agents, honey and Nigella sativa may have therapeutic promise in renal fibrosis. This study aim to investigate the effects of the combination of honey and Nigella sativa oil as anti-inflammatory and antioxidant agents in a rat model of unilateral ureteral obstruction (UUO)-induced kidney injury. In this study, thirty male Wistar rats were divided randomly into five groups. One sham group, one UUO group, and three UUO groups that received varied doses of the combination of honey and Nigella sativa oil (HoNi). HoNi was administered to the rats orally, once daily for 21 days starting from the 14th day post-UUO induction. After treatment, blood samples were collected, and the levels of antioxidant enzymes; Superoxide Dismutase (SOD), Glutathione (GSH), and Catalase (CAT) were measured. The inflammatory marker; C-reactive protein (CRP) activity, and haemoglobin (Hb) levels were also measured. The results showed that the administration of the combination of honey and Nigella sativa for 21 days in UUO rat model significantly reduced CRP, while increasing the activities of SOD, GSH, and CAT, and also enhanced haemoglobin levels in a dose-dependent manner.These findings suggest that the renoprotective effect of the combination of honey and Nigella sativa oil maybe associated with its antiinflammatory and antioxidant properties. [ABSTRACT FROM AUTHOR]

Iguratimod is a novel synthetic, small-molecule immunosuppressive agent used to treat rheumatoid arthritis. Through ongoing exploration of its role and mechanisms of action, iguratimod has been observed to have antifibrotic effects in the lung and skin; however, its effect on renal fibrosis remains unknown. This study aimed to investigate whether iguratimod could affect renal fibrosis progression. Three different concentrations of iguratimod (30 mg/kg/day, 10 mg/kg/day, and 3 mg/kg/day) were used to intervene in unilateral ureteral obstruction (UUO) model mice. Iguratimod at 10 mg/kg/day was observed to be effective in slowing UUO-mediated renal fibrosis. In addition, stimulating bone marrow-derived macrophages with IL-4 and/or iguratimod, or with TGF-β and iguratimod or SRC inhibitors in vitro, suggested that iguratimod mitigates the progression of renal fibrosis in UUO mice, at least in part, by inhibiting the IL-4/STAT6 signaling pathway to attenuate renal M2 macrophage infiltration, as well as by impeding SRC activation to reduce macrophage–myofibroblast transition. These findings reveal the potential of iguratimod as a treatment for renal disease.

Objective: To discuss the effect of NOD-like receptor protein 3（NLRP3) inflammasome on the renal interstitial fibrosis in the unilateral ureteral obstruction (UUO) model rats, and to clarify its potential mechanism. Methods: Thirty healthy male Wistar rats were randomly divided into sham operation group (n=6) and UUO group (n=24) . The rats in sham operation group underwent the dissection of the ureter without ligation, while the rats in UUO group were sacrificed on the 3rd, 7th, and 14th days after operation, and based on the treatment duration, the rats were divided into UUO 3 d group (n=8), UUO 7 d group (n=8), and UUO 14 d group (n=8) . HE staining and Masson staining were used to observe the pathomorphology of kidney tissue of the rats in various groups; reagent kits were used to detect the levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD), and levels of hydroxyproline (HYP) in kidney tissue of the rats in various groups；immunohistochemistry method was used to detect the expression levels of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF- β1) proteins in kidney tissue of the rats in various groups; Western blotting method was used to detect the expression levels of NLRP3 protein in kidney tissue of the rats in various groups. Results: The HE staining results showed significant tubular dilation, interstitial edema, and widening, with increased infiltration of inflammatory cells, and shedding of epithelial cells was seen in parts of the tubular lumina of the rats in UUO group. Compared with sham operation group, the interstitial fibrosis scores of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were significantly increased (P<0. 05); compared with UUO 3 d group and UUO 7 d group, the interstitial fibrosis score of the rats in UUO 14 d group was significantly decreased（P<0. 05) . The Masson staining results showed that in UUO group, there was evident infiltration of inflammatory cells in the renal interstitium and a noticeable increase in fibrotic tissue proliferation; with the increasing of duration of UUO, some tubular structures disappeared, and the interstitial widened further with gradually increasing collagen deposition, particularly at the corticomedullary junction. Compared with sham operation group, the interstitial fibrosis scores of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were significantly increased (P<0. 05); and compared with UUO 3 d and UUO 7 d groups, the interstitial fibrosis score of the rats in UUO 14 d group was significantly decreased (P<0. 05) . Compared with sham operation group, the levels of MDA in obstructed kidney tissue of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were significantly increased (P<0. 05), and the SOD activities were significantly decreased (P<0. 05) . Compared with sham operation group, the levels of HYP in obstructed kidney tissue of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were also significantly increased (P<0. 05); compared with UUO 3 d group, the level of HYP in obstructed kidney tissue of the rats in UUO 14 d group was significantly increased (P<0. 05) . The immunohistochemistry results showed that compared with sham operation group, the expression levels of α -SMA protein in kidney tissue of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were significant increased (P< 0. 05); compared with UUO 3 d and UUO 7 d groups, the expression levels of α -SMA protein in kidney tissue of the rats in UUO 14 d group was significantly increased (P<0. 05); compared with sham operation group, the expression levels of TGF- β1 protein in renal tubular epithelial cells and renal tubule interstitial tissue of the rats in UUO 3 d, UUO 7 d, and UUO 14 d groups were also significantly increased (P<0. 05); compared with UUO 3 d group, the expression levels of TGF- β1 protein in the tubular epithelial cells and renal tubule interstitial tissue of the rats in UUO 14 d group were significantly decreased (P<0. 05) . The Western blotting results showed that compared with sham operation group, the expression levels of NLRP3 protein in kidney tissue of the rats in UUO 7 d and UUO 14 d groups were significantly increased (P<0. 05) . Conclusion: The NLRP3 inflammasome plays a critical role in renal fibrosis of the UUO rats, and its mechanism may be related to the increasing of oxidative stress and the increasing of expression level of TGF-β1 protein. [ABSTRACT FROM AUTHOR]

Objectives: Ellagic acid (EA), a kind of polyphenol found in numerous fruits and vegetables, has anti-inflammatory, anti-apoptotic, anti-oxidant, and anti-fibrotic effects against a variety of diseases, but its role in mediating renal fibrogenesis remains unknown. Materials and Methods: We used an in vivo mouse unilateral ureteral obstruction (UUO) model and an in vitro model with HK-2 cell lines treated with EA and transforming growth factor β1 (TGF-β1). The expression of epithelial-to-mesenchymal transition (EMT)-related proteins of UUO mice was examined using immunohistochemical staining. Liver function and renal function were evaluated using biochemical testing. Western blot analysis was used to determine the proteins related to EMT, and MTT assay was used to determine cell viability. Results: In UUO mice fed EA, both microscopical examination with immunohistochemical staining and western blotting protein analysis showed reduced expression of fibrotic (α-SMA, fibronectin, and collagen I)- and EMT (vimentin and N-cadherin)-related proteins, compared with sham control. In HK-2 cells treated with TGF-β1, EA decreased motility as well as expression of α-SMA, collagen-I, fibronectin, N-cadherin, and vimentin. Conclusion: EA reduced the progression of the morphological transformations and concomitantly suppressed the expression of fibrotic- and EMT-related proteins in vitro and in vivo. These findings improved our understanding of the role of EA in suppressing renal fibrogenesis and demonstrated the promising role EA may play in the management of chronic kidney disease.

Introduction: Renal fibrosis is a critical event in the development and progression of chronic kidney disease (CKD), and it is considered the final common pathway for all types of CKD. The prevalence of CKD is higher in females; however, males have a greater prevalence of end-stage renal disease. In addition, low birth weight and low nephron number are associated with increased risk for CKD. This study examined the development and severity of unilateral ureter obstruction (UUO)-induced renal fibrosis in male and female wild-type (ROP +/+) and mutant (ROP Os/+) mice, a mouse model of low nephron number. Methods: Male and female ROP +/+ and ROP Os/+ mice were subjected to UUO, and kidney tissue was collected at the end of the 10-day experimental period. Kidney histological analysis and mRNA expression determined renal fibrosis, tubular injury, collagen deposition, extracellular matrix proteins, and immune cell infiltration. Results: Male and female UUO mice demonstrated marked renal injury, kidney fibrosis, and renal extracellular matrix production. Renal fibrosis and α-smooth muscle actin were increased to a similar degree in ROP +/+ and ROP Os/+ mice with UUO of either sex. There were also no sex differences in renal tubular cast formation or renal infiltration of macrophage in ROP +/+ and ROP Os/+ UUO mice. Interestingly, renal fibrosis and α-smooth muscle actin were 1.5–3-fold greater in UUO-ROP +/+ compared to UUO-ROP Os/+ mice. Renal inflammation phenotypes following UUO were also 30–45% greater in ROP +/+ compared to ROP Os/+ mice. Likewise, expression of extracellular matrix and renal fibrotic genes was greater in UUO-ROP +/+ mice compared to UUO-ROP Os/+ mice. In contrast to these findings, ROP Os/+ mice with UUO demonstrated glomerular hypertrophy with 50% greater glomerular tuft area compared to ROP +/+ with UUO. Glomerular hypertrophy was not sex-dependent in any of the genotypes of ROP mice. These findings provide evidence that low nephron number contributes to UUO-induced glomerular hypertrophy in ROP Os/+ mice but does not enhance renal fibrosis, inflammation, and renal tubular injury. Conclusion: Taken together, we demonstrate that low nephron number contributes to enhanced glomerular hypertrophy but not kidney fibrosis and tubular injury. We also demonstrate that none of the changes caused by UUO was affected by sex in any of the ROP mice genotypes.

Introduction: Renal fibrosis is a critical event in the development and progression of chronic kidney disease (CKD), and it is considered the final common pathway for all types of CKD. The prevalence of CKD is higher in females; however, males have a greater prevalence of end-stage renal disease. In addition, low birth weight and low nephron number are associated with increased risk for CKD. This study examined the development and severity of unilateral ureter obstruction (UUO)-induced renal fibrosis in male and female wild-type (ROP +/+) and mutant (ROP Os/+) mice, a mouse model of low nephron number. Methods: Male and female ROP +/+ and ROP Os/+ mice were subjected to UUO, and kidney tissue was collected at the end of the 10-day experimental period. Kidney histological analysis and mRNA expression determined renal fibrosis, tubular injury, collagen deposition, extracellular matrix proteins, and immune cell infiltration. Results: Male and female UUO mice demonstrated marked renal injury, kidney fibrosis, and renal extracellular matrix production. Renal fibrosis and α-smooth muscle actin were increased to a similar degree in ROP +/+ and ROP Os/+ mice with UUO of either sex. There were also no sex differences in renal tubular cast formation or renal infiltration of macrophage in ROP +/+ and ROP Os/+ UUO mice. Interestingly, renal fibrosis and α-smooth muscle actin were 1.5–3-fold greater in UUO-ROP +/+ compared to UUO-ROP Os/+ mice. Renal inflammation phenotypes following UUO were also 30–45% greater in ROP +/+ compared to ROP Os/+ mice. Likewise, expression of extracellular matrix and renal fibrotic genes was greater in UUO-ROP +/+ mice compared to UUO-ROP Os/+ mice. In contrast to these findings, ROP Os/+ mice with UUO demonstrated glomerular hypertrophy with 50% greater glomerular tuft area compared to ROP +/+ with UUO. Glomerular hypertrophy was not sex-dependent in any of the genotypes of ROP mice. These findings provide evidence that low nephron number contributes to UUO-induced glomerular hypertrophy in ROP Os/+ mice but does not enhance renal fibrosis, inflammation, and renal tubular injury. Conclusion: Taken together, we demonstrate that low nephron number contributes to enhanced glomerular hypertrophy but not kidney fibrosis and tubular injury. We also demonstrate that none of the changes caused by UUO was affected by sex in any of the ROP mice genotypes. [ABSTRACT FROM AUTHOR]

Renal fibrosis is a pathological feature of chronic kidney disease (CKD), progressing toward end-stage kidney disease (ESKD). The aim of this study is to investigate the therapeutic potential of altenusin, a farnesoid X receptor (FXR) agonist derived from fungi, on renal fibrosis. The effect of altenusin was determined (i) in vitro using the transforming growth factor β1 (TGF-β1)-induced epithelial to mesenchymal transition (EMT) of human renal proximal tubular cells and (ii) in vivo using mouse unilateral ureteral obstruction (UUO). The findings revealed that incubation of 10 ng/ml TGF-β1 promotes morphological change in RPTEC/TERT1 cells, a human renal proximal tubular cell line, from epithelial to fibroblast-like cells. TGF-β1 markedly increased EMT markers namely α-smooth muscle actin (α-SMA), fibronectin, and matrix metalloproteinase 9 (MMP-9), while decreased the epithelial marker E-cadherin. Co-incubation TGF-β1 with altenusin preserved the epithelial characteristics of the renal epithelial cells by antagonizing TGF-β/Smad signaling pathway, specifically a decreased phosphorylation of Smad2/3 with an increased level of Smad7. Interestingly, the antagonizing effect of altenusin does not require FXR activation. Moreover, altenusin could reverse TGF-β1-induced fibroblast-like cells to epithelial-like cells. Treatment on UUO mice with 30 mg/kg altenusin significantly reduced the expression of α-SMA, fibronectin, and collagen type 1A1 (COL1A1). The reduction in the renal fibrosis markers is correlated with the decreased phosphorylation of Smad2/3 levels but does not improve E-cadherin protein expression. Collectively, altenusin reduces EMT in human renal proximal tubular cells and renal fibrosis by antagonizing the TGF-β/Smad signaling pathway.

Renal fibrosis is recognized as a key pathological feature of chronic kidney disease (CKD), which progresses toward end stage renal disease (ESRD). Transforming growth factor (TGF)-β-induced epithelial to mesenchymal transition (EMT) of renal epithelial tubular cells is the key mechanism of renal fibrosis. The aim of this study is to investigate the pharmacological effect of altenusin, an active compound derived from fungi, on TGF-β/mitogenactivated protein kinase (MAPK) signaling pathway-induced fibrosis in renal proximal tubular cells and in mouse unilateral ureteral obstruction (UUO) model. As a result, TGF-β1 induced EMT of RPTECT/TERT1 cells (an immortalized human renal proximal tubular cells) by concentration- and time-dependent manners. Incubating cells with 10 ng/ml TGF-β1 for 48 hours significantly upregulated MAPK signaling pathway by increase phosphorylated (p)-Jun N-terminal kinase (JNK), p-p38, and p-Extracellular signal-regulated kinase (ERK) 1/2. Treating the cells with altenusin (50 -100 µM) significantly attenuated TGF-β1-induced EMT. The inhibitory effect of altenusin on EMT was mediated by inhibition of p38 and ERK1/2 but not JNK. UUO in mice for 14 days dramatically increased p-JNK, p-p38, and p-ERK1/2, activation of these proteins by UUO were attenuated by co-treatment with altenusin 3 mg/kg. These results demonstrate the inhibitory effect of altenusin on TGF-β/MAPK signaling pathway-induced EMT in human renal proximal tubular cells and in animal model of renal fibrosis. [ABSTRACT FROM AUTHOR]

Tubular epithelial cell fate following exposure to various types of injurious stimuli can be decided at distinct cell cycle checkpoints. One such checkpoint occurs during mitosis, known as the spindle assembly checkpoint, and is tightly regulated through the actions of cell division cycle protein 20 (CDC20). Due to our paucity of knowledge about the role of CDC20 in the kidney, the present study was designed to investigate the expression levels and distribution of CDC20 within the kidney and how pharmacological inhibition of CDC20 function affects kidney recovery using various rodent models of kidney injury. CDC20 is normally detected in distal tubules, but upon injury by either cisplatin administration or ureter obstruction, CDC20 accumulation is considerably elevated. Blockade of CDC20 activity using a selective pharmacological inhibitor, Apcin, lowered serum creatinine, tubular damage, and DNA injury following acute kidney injury compared with vehicle-treated mice. In unilateral ureteral obstruction, Apcin reduced tissue kidney injury molecule-1 levels, sirius red staining, and tubulointerstitial α-smooth muscle actin staining in the tissue. The findings in the present study demonstrated that elevations in CDC20 levels in the kidney are associated with kidney injury and that inhibition of CDC20 can alleviate and reverse some of the pathological effects on the architecture and function of kidney. NEW & NOTEWORTHY To our knowledge, this is the first study to characterize the expression and localization of cell division cycle 20 protein (CDC20) in normal and acute, and chronically injured kidneys. Tubular epithelial cell damage was markedly reduced through the administration of a selective inhibitor of CDC20, Apcin. This study provides new evidence that CDC20 can be induced in damaged kidney cells and negatively impact the recovery of the kidney following acute kidney injury. [ABSTRACT FROM AUTHOR]

Emerging evidence suggests that myo-inositol (MI) has a critical role in reducing renal inflammatory processes and improving podocyte function and preventing diabetes-related renal damage. We aimed to explore the function and underlying workings of MI in renal interstitial fibrosis (RIF). Based on a mouse model, we explored the effect of MI in unilateral ureteral obstruction (UUO) and in transforming growth factor-β1 (TGF-β1)-treated HK-2 cells. Pathological changes of the kidney tissues were examined following staining of the tissues with hematoxylin, eosin, and Masson's trichrome. The mRNA quantities of fibrosis markers, fibronectin, α-smooth muscle actin (α-SMA), and collagen I, were analyzed by means of real-time polymerase chain reaction, whereas those of protein levels were assessed with Western blotting. We also determined the expression of collagen I by immunofluorescence, and the levels of phosphorylated phosphotidylinositol-3-kinase and protein kinase B (PI3K/AKT) by Western blot. In vivo, histopathological examination in the UUO mice revealed renal tubular epithelial cell necrosis, inflammatory cell infiltration, and RIF. UUO mice showed higher expression levels of collagen I, fibronectin, α-SMA, pPI3K, and pAKT compared with sham-operated mice. However, MI treatment diminished the pathological alterations of RIF in UUO mice and downregulated the expression of fibrosis markers and phosphorylated PI3K/AKT. In vitro, TGF-β1 positively influenced the propagation and differentiation of HK-2 cells and upregulated the levels of α-SMA, fibronectin, collagen I, pPI3K, and pAKT, but these became significantly reversed by MI treatment. In conclusion, MI ameliorates RIF, possibly by negatively regulating TGF-β1-induced epithelial transdifferentiation and PI3K/AKT activation. [ABSTRACT FROM AUTHOR]

Introduction: The receptor for advanced glycation end products (RAGE) and its ligands, such as high-mobility group protein box 1 (HMGB1), play an important role in the accumulation of extracellular matrix in chronic kidney diseases with tubulointerstitial fibrosis. Blocking RAGE signaling with soluble RAGE (sRAGE) is a therapeutic candidate for renal fibrosis. Methods: NRK-52E cells were stimulated with or without HMGB1 and incubated with sRAGE in vitro. Sprague-Dawley rats were intraperitoneally treated with sRAGE after unilateral ureteral obstruction (UUO) operation in vivo. Results: HMBG1-stimulated NRK-52E cells showed increased fibronectin expression, type I collagen, a-smooth muscle actin, and connective tissue growth factor, which were attenuated by sRAGE. The mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of nuclear factor kappa B (NF-κB) were enhanced in NRK-52E cells exposed to HMBG1, and sRAGE treatment alleviated the activation of the MAPK and NF-κB pathways. In the UUO rat models, sRAGE significantly ameliorated the increased renal fibronectin, type I collagen, and α-smooth muscle actin expressions. Masson's trichrome staining confirmed the anti-fibrotic effect of sRAGE in the UUO rat model. RAGE also significantly attenuated the activation of the MAPK pathway and NF-κB, as well as the increased number of infiltrated macrophages within the tubulointerstitium in the kidney of the UUO rat models. Conclusion: These findings suggest that RAGE plays a pivotal role in the pathogenesis of renal fibrosis and that its inhibition by sRAGE may be a potential therapeutic approach for renal fibrosis. [ABSTRACT FROM AUTHOR]

Bone marrow-derived mesenchymal stem cells (MSCs) show antifibrotic activity in various chronic kidney diseases. Here, we aimed to investigate whether Calycosin (CA), a phytoestrogen, could enhance the antifibrotic activity of MSCs in primary tubular epithelial cells (PTECs) induced by TGF-β1 and in a mouse model of unilateral ureteral obstruction (UUO). We found that MSCs treatment significantly inhibited fibrosis, and CA pretreatment enhanced the effects of MSCs on fibrosis in vitro. Consistent with the in vitro studies, MSCs alleviated tubular injury and renal fibrosis in mice after UUO, and CA-pretreated MSCs resulted in more significant improvements in tubular injury and renal fibrosis than MSCs after UUO. Moreover, MSCs treatment significantly inhibited necroptosis by repressing the elevation of MLKL, RIPK1, and RIPK3 in PTECs treated by TGF-β1and in mice after UUO, and CA-pretreated MSCs were superior to MSCs in alleviating necroptosis. MSCs significantly reduced TNF-α and TNFR1 expression induced by TGF-β1 in PTECs and inhibited TGF-β1, TNF-α, and TNFR1 expression induced by UUO in mice. These effects of MSCs were significantly enhanced after CA pretreatment. Therefore, our results suggest that CA pretreatment enhances the antifibrotic activity of MSCs by inhibiting TGF-β1/TNF-α/TNFR1 signaling-induced necroptosis.

Renal fibrosis is a common characteristic and the final pathological mechanism of chronic kidney disease (CKD). Although CKD remains incurable, inhibition of renal fibrosis is beneficial to inhibit the CKD process. Relaxin alleviates renal fibrosis in some experimental models, but its mechanism remains unclear. In the following, we studied the regulatory effect of relaxin on epithelial-mesenchymal transition (EMT) after unilateral ureteral obstruction (UUO). Our results demonstrate that relaxin could downregulate Wnt/β-catenin signaling and decrease EMT, thus protecting against loss of transporters in tubular epithelial cells (TECs) and abrogate renal interstitial fibrosis following UUO. We confirmed that relaxin can downregulate Wnt/β-catenin signaling and decrease EMT in NRK52E, thus abrogating G2 cell cycle arrest in vitro experiments. Therefore, a novel mechanism by which relaxin is antifibrotic is that relaxin regulates the EMT program of TECs via Wnt/β-catenin signaling pathway. The inhibition of EMT contributes to protecting the functional capabilities of TECs and promoting the regeneration of TECs.

Context Protocatechuic aldehyde (PCA) is a natural product that has various benefits for fibrosis.Objective This study evaluated the effects of PCA on renal fibrosis.Materials and methods Epithelial–mesenchymal transition (EMT) was induced by 20 ng/mL transforming growth factor-β1 (TGF-β1), followed by treatment with 1 and 5 μM PCA, in the rat renal proximal tubular cell line NRK-52E. Cell viability, protein expression, and scratch wound-healing assays were conducted. Sprague–Dawley (SD) rats underwent unilateral ureteral obstruction (UUO) surgery for renal fibrosis indication and were treated with 50 and 100 mg/kg PCA for 14 days.Results The IC50 of PCA was appropriately 13.75 ± 1.91 μM in NRK-52E cells, and no significant difference at concentrations less than 5 μM. PCA ameliorated TGF-β1-induced EMT, such as enhanced E-cadherin and decreased vimentin. Fibrotic markers collagen IV and α-smooth muscle actin (α-SMA) increased in TGF-β1-induced NRK-52E. Moreover, PCA reduced TGF-β1-induced migration in the wound-healing assay. Analysis of rat kidneys indicated that PCA reduced UUO-induced hydronephrosis (control: 15.11 ± 1.00%; UUO: 39.89 ± 1.91%; UUO + PCA50: 18.37 ± 1.61%; UUO + PCA100: 17.67 ± 1.39%). Protein level demonstrated that PCA not only decreased vimentin expression and enhanced E-cadherin expression, but inhibited UUO-induced collagen IV and α-SMA upregulation, indicating that it could mitigate EMT in a rat model of UUO-induced renal fibrosis.Discussion and conclusions This study suggested that PCA decreases TGF-β1-induced fibrosis and EMT in vitro and in vivo. These findings demonstrate pharmacological effects of PCA and might be a potential strategy for the prevention of organ fibrosis in clinics.

AIM: To investigate the inhibitory effect of modulating nuclear factor E2-related factor 2 （Nrf2）/glutathione peroxidase 4 （GPX4） signaling pathway on ferroptosis and renal fibrosis in unilateral ureteral obstruction （UUO） mice. METHODS: The expression levels of GPX4, Nrf2 and α-smooth muscle actin（ α-SMA） were measured by immunohistochemistry in paraffin sections of kidney puncture specimens from 9 chronic kidney disease （CKD） patients and 9 non-CKD patients. In animal experiments, 25 male C57BL/6 mice （6 to 8 weeks old） were randomly divided into 5 groups: sham group, UUO group, UUO+liproxstatin-1 （Lip-1; ferroptosis inhibitor） group, UUO+sulforaphane （SFN; Nrf2 agonist） group, and UUO+irbesartan （IRB） group. The mice in each group were fed with normal chow for 1 week, and those in the latter 3 groups were intraperitoneally injected with Lip-1 （10 mg·kg-1·d-1）, SFN （25 mg·kg-1·d-1） and urea nitrogen. Kidney tissues were embedded in paraffin and stained with HE, Masson and Sirius red to observe the renal pathological changes. Western blot, RT-qPCR and immunohistochemistry were applied to determine the expression levels of Nrf2, GPX4, solute carrier family 7 member 11 （SLC7A11）, fibronectin （Fn）, collagen type I （Col-I）, α-SMA, and NADPH oxidase 4 （NOX4） in mouse kidney tissues. RESULTS: Immunohistochemical results showed that the expression levels of GPX4 and Nrf2 were lower in CKD patients than those in non-CKD patients, while the expression of α-SMA was higher than that in non-CKD patients. In animal experiments, the mice in the 3 treatment groups had improved renal function, reduced fibrosis, and decreased expression of renal fibrosis-related indexes compared with UUO group. The expression levels of Nrf2, GPX4 and SLC7A11 in renal tissues of Lip-1 and SFN treatment groups were higher than those of UUO group（ P<0. 05）, while the expression of NOX4 was lower than that of UUO group（ P<0. 05）. CONCLUSION: Fibrosis and ferroptosis were significantly increased in the kidneys of CKD patients and UUO mice. Regulation of Nrf2/GPX4 signaling pathway could effectively inhibit ferroptosis and attenuate kidney fibrosis in UUO mice. [ABSTRACT FROM AUTHOR]

Folic acid exerts both anti-inflammatory and antifibrotic effects. Glycine N-methyltransferase (GNMT), the major folic acid-binding protein in the liver, is a crucial enzyme that regulates the cellular methylation process by maintaining S-adenosylmethionine levels. However, as yet neither the therapeutic effects of folic acid in renal fibrosis nor whether GNMT is involved in these folic acid-associated mechanisms has been investigated. First, the expression of GNMT was examined in human kidneys with or without obstructive nephropathy. Later, wild-type and GNMT knockout (GNMT−/−) mice were subjected to unilateral ureteral obstruction (UUO) and then treated with either folic acid or vehicle for 14 days. Renal tubular injury, inflammation, fibrosis, and autophagy were evaluated by histological analysis and Western blotting. We observed increased expression of GNMT in humans with obstructive nephropathy. Furthermore, UUO significantly increased the expression of GNMT in mice; in addition, it caused renal injury as well as the development of both hydronephrosis and tubular injury. These were all alleviated by folic acid treatment. In contrast, GNMT−/− mice exhibited exacerbated UUO-induced renal injury, but the protective effect of folic acid was not observed in GNMT−/− mice. We propose a novel role for folic acid in the treatment of renal fibrosis, which indicates that GNMT may be a therapeutic target. [ABSTRACT FROM AUTHOR]

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Background: Chronic Kidney Disease (CKD) is a problem in nephrology with a fairly high incidence rate, the final condition of CKD is the presence of kidney fibrosis in the tubulointerstitial region depending on the polarization of macrophages. Basil antioxidant efficacious leaves can prevent damage to tubular cells in animals. Objective: To determine the effect of giving basil leaf extract (Ocimum basilicum L.) on the amount of M2 macrophages in mice (Mus musculus) with the Unilateral Ureteral Obstruction method. Methods: This research use an experimental study using a posttest only with randomized controlled group design. Results: Data on administration of basil leaf extract (Ocimum basilicum L.) to mice can reduce damage to the kidneys analyzed using LSD test obtained p value (0.000

Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites with biological effects, including antiapoptotic, anti-inflammatory, and antifibrotic functions. Soluble epoxide hydrolase (sEH)-mediated hydrolysis of EETs to dihydroxyeicosatrienoic acids (DHETs) attenuates these effects. Recent studies have demonstrated that inhibition of sEH prevents renal tubulointerstitial fibrosis and inflammation in the chronic kidney disease model. Given the pathophysiological role of the EET pathway in chronic kidney disease, we investigated if administration of EET regioisomers and/or sEH inhibition will promote antifibrotic and renoprotective effects in renal fi- brosis following unilateral ureteral obstruction (UUO). EETs administration abolished tubulointerstitial fibrogenesis, as demonstrated by reduced fibroblast activation and collagen deposition after UUO. The inflammatory response was prevented as demonstrated by decreased neutrophil and macrophage infiltration and expression of cytokines in EET-administered UUO kidneys. EET administration and/or sEH inhibition significantly reduced M1 macrophage markers, whereas M2 macrophage markers were highly upregulated. Furthermore, UUO-induced oxidative stress, tubular injury, and apoptosis were all downregulated following EET administration. Combined EET administration and sEH inhibition, however, had no additive effect in attenuating inflammation and renal interstitial fibrogenesis after UUO. Taken together, our findings provide a mechanistic understanding of how EETs prevent kidney fibrogenesis during obstructive nephropathy and suggest EET treatment as a potential therapeutic strategy to treat fibrotic diseases. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to establish a suitable animal model of chronic kidney disease–mineral and bone disorder (CKD–MBD) by comparing CKD–MBD rat models induced by 5/6 Nx, AN, and UUO, accompanied by a low-calcium and highphosphorus diet. Methods: Sprague‒Dawley rats were randomly divided into four groups: control group, 5/6 nephrectomy (5/6 Nx) group, Adriamycin nephropathy (AN) group, and unilateral ureteral obstruction (UUO) group. Serum biochemical indices were measured to evaluate renal function, mineral and bone metabolism, the severity of CKD–MBD, and the status of bone transformation. Hematoxylin–eosin staining (HE) and Masson’s trichrome (Masson) staining were used for histopathological analysis of the kidney. Goldner’s trichrome (Goldner) and tartrate-resistant acid phosphatase (TRAP) staining were utilized to observe bone mineralization and osteoclasts in the femur, respectively. Micro-CT images were applied to study the structure of the femur. The expression levels of osterix and cathepsin K in the femur were measured by immunohistochemistry (IHC) to confirm the status of bone transformation. Results: The levels of serum creatinine (Scr) and blood urea nitrogen (BUN) in the 5/ 6 Nx and AN group rats were significantly higher than those in the control rats, and this change was accompanied by marked changes in the levels of calcium (Ca), phosphate (Pi), intact parathyroid hormone (i-PTH), fibroblast growth factor 23 (FGF23), osteocalcin (OC), and cross-linked C-telopeptide of type 1 collagen (CTX-1); UUO group rats exhibited slight and inconsistent variations in the levels of Scr, BUN, Ca, Pi, i-PTH, FGF23, OC, and CTX-1 in serum. Histopathological analysis of the kidney showed that the UUO group rats suffered serious fibrosis and 5/6 Nx group rats exhibited severe focal calcification. Histopathological analysis of the femur showed that the AN group rats had minimal bone mineralization and that the 5/6 Nx group rats had overactive osteoclasts. Micro-CT revealed that the AN model had the most severe bone destruction and that the 5/6 Nx model had the least severe bone loss among the three models. The expression of cathepsin K in the femur was significantly increased in all models, while the expression of osterix in the femur was only significantly increased in the 5/6 Nx model. Conclusion: 5/6 Nx, AN, and UUO accompanied by a low-calcium and highphosphorus diet successfully induced CKD–MBD in rats. The 5/6 NX model presented the progression of high-turnover bone disease, with consistency between biochemical indices in serum and histomorphometric analysis of the femur, and the AN and UUO models developed a severe deterioration in bone quantity and severe bone resorption; however, the changes in biochemical indices were subtle in the UUO model, and liver injury was obvious in the AN model. [ABSTRACT FROM AUTHOR]

Introduction: Chronic kidney disease (CKD) is a major public health issue worldwide, which is characterized by irreversible loss of nephron and renal function. However, the molecular mechanism of CKD remains underexplored. Methods: This study integrated three transcriptional profile datasets to investigate the molecular mechanism of CKD. The differentially expressed genes (DEGs) between Sham control (Con) and unilateral ureteral obstruction (UUO)-operated mice were analyzed by utilizing the limma package in R. The shared DEGs were analyzed by Gene Ontology and functional enrichment. Protein-protein interactions (PPIs) were constructed by utilizing the STRING database. Hub genes were analyzed by MCODE and Cytohubba. We further validated the gene expression by using the other dataset and mouse UUO model. Results: A total of 315 shared DEGs between Con and UUO samples were identified. Gene function and KEGG pathway enrichment revealed that DEGs were mainly enriched in inflammatory response, immune system process, and chemokine signaling pathway. Two modules were clustered based on PPI network analysis. Module 1 contained 13 genes related to macrophage activation, migration, and chemotaxis. Ten hub genes were identified by PPI network analysis. Subsequently, the expression levels of hub genes were validated with the other dataset. Finally, these four validated hub genes were further confirmed by our UUO mice. Three validated hub genes, Gng2, Pf4, and Ccl9, showed significant response to UUO. Conclusion: Our study reveals the coordination of genes during UUO and provides a promising gene panel for CKD treatment. GNG2 and PF4 were identified as potential targets for developing CKD drugs. [ABSTRACT FROM AUTHOR]

Background: Renin-angiotensin system (RAS) is prominently associated with renal pathophysiology in postmenopausal women. Long non-coding RNAs (lncRNAs) H19, GAS5, MIAT, and Rian have been linked to the pathogenesis of renal injury. Aims: This study aimed to evaluate the beneficial effects of daidzein on unilateral ureteral obstruction (UUO) induced-renal injury in ovariectomized (OVX) rats through interaction with angiotensin AT1, Mas receptors, and lncRNAs. Methods: 84 female rats were ovariectomized (OVX) two weeks before performing obstruction of the left kidney ureter (UUO). The animals were then randomly divided into four main groups (n=21): Sham+DMSO, UUO+DMSO, UUO+17ß-Estradiol (E2) (positive control), and UUO+daidzein. Each main group comprised three subgroups (n=7) and were treated with saline, A779 (MasR antagonist), or losartan (AT1R antagonist) for 15 days. On day 16, the animals were euthanized, and the left kidneys were harvested for histopathology and lncRNAs expression assays. Results: UUO significantly increased kidney tissue damage score (KTDS) in the UUO rats, increased the expression of H19 and MIAT, and decreased the expression of GAS5 and Rian. Daidzein alone and in cotreatment with losartan or A779 reversed these effects. Daidzein with 1 mg/kg dose was more effective than E2. Conclusion: Daidzein alone and in co-treatment with A779 and losartan improved renal injury in UUO rats and recovered dysregulated expression of UUOrelated lncRNAs through modulating MasR and AT1R receptors, associating with modulation of the expression of lncRNAs. Daidzein could be considered a renoprotective phytoestrogen substitute for E2 therapy in postmenopausal women suffering from renal diseases. [ABSTRACT FROM AUTHOR]

Renal fibrosis is a major factor in the progression of chronic kidney diseases. Obstructive nephropathy is a common cause of renal fibrosis, which is also accompanied by inflammation. To explore the effect of human‐specific CHRFAM7A expression, an inflammation‐related gene, on renal fibrosis during obstructive nephropathy, we studied CHRFAM7A transgenic mice and wild type mice that underwent unilateral ureteral obstruction (UUO) injury. Transgenic overexpression of CHRFAM7A gene inhibited UUO‐induced renal fibrosis, which was demonstrated by decreased fibrotic gene expression and collagen deposition. Furthermore, kidneys from transgenic mice had reduced TGF‐β1 and Smad2/3 expression following UUO compared with those from wild type mice with UUO. In addition, the overexpression of CHRFAM7A decreased release of inflammatory cytokines in the kidneys of UUO‐injured mice. In vitro, the overexpression of CHRFAM7A inhibited TGF‐β1‐induced increase in expression of fibrosis‐related genes in human renal tubular epithelial cells (HK‐2 cells). Additionally, up‐regulated expression of CHRFAM7A in HK‐2 cells decreased TGF‐β1‐induced epithelial‐mesenchymal transition (EMT) and inhibited activation f TGF‐β1/Smad2/3 signalling pathways. Collectively, our findings demonstrate that overexpression of the human‐specific CHRFAM7A gene can reduce UUO‐induced renal fibrosis by inhibiting TGF‐β1/Smad2/3 signalling pathway to reduce inflammatory reactions and EMT of renal tubular epithelial cells. [ABSTRACT FROM AUTHOR]

Renal fibrosis is a common characteristic and the final pathological mechanism of chronic kidney disease (CKD). Although CKD remains incurable, inhibition of renal fibrosis is beneficial to inhibit the CKD process. Relaxin alleviates renal fibrosis in some experimental models, but its mechanism remains unclear. In the following, we studied the regulatory effect of relaxin on epithelial-mesenchymal transition (EMT) after unilateral ureteral obstruction (UUO). Our results demonstrate that relaxin could downregulate Wnt/β-catenin signaling and decrease EMT, thus protecting against loss of transporters in tubular epithelial cells (TECs) and abrogate renal interstitial fibrosis following UUO. We confirmed that relaxin can downregulate Wnt/β-catenin signaling and decrease EMT in NRK52E, thus abrogating G2 cell cycle arrest in vitro experiments. Therefore, a novel mechanism by which relaxin is antifibrotic is that relaxin regulates the EMT program of TECs via Wnt/β-catenin signaling pathway. The inhibition of EMT contributes to protecting the functional capabilities of TECs and promoting the regeneration of TECs. [ABSTRACT FROM AUTHOR]

Objective To determine the improving effect of salvianolic acid B on renal interstitial fibrosis (RIF) of rats with unilateral ureteral obstruction (UUO) based on ferroptosis mediated by nuclear factor erythroid 2-related factor 2 (Nrf2)-glutathione peroxidase 4 (Gpx4) pathway. Methods A total of 40 rats were divided into sham operation group, model group, salvianolic acid B group, and salvianolic acid B+Nrf2 inhibitor group, with 10 rats in each group. UUO model was established in the latter 3 groups, and those of the sham operation group received the same operation except for not ligating and cutting the ureter. Salvianolic acid B of 100 mg·kg-1·d-1 and Nrf2 inhibitor ML385 of 30 mg·kg-1·d-1 were intragastrically administered to the corresponding groups, and sterile normal saline of equal volume was given to the sham operation group and model group, for 9 consecutive days. Hematoxylin-eosin (HE) staining and Masson staining were used to detect the morphology and fibrosis in renal tissues. The contents of Fe2+, maleicdialdehyde (MDA) and activity of superoxide dismutase (SOD) in renal tissues were detected with corresponding kits. Quantitative real-time PCR (RT-qPCR) and Western blotting were used to detect the mRNA and protein levels of Collagen-Ⅰ (CoL-Ⅰ), Collagen-Ⅲ (CoL-Ⅲ), Nrf2, and Gpx4 in the renal tissues. Results Compared with the sham operation group, the contents of Fe2+ and MDA and the mRNA and protein levels of CoL-Ⅰ and CoL-Ⅲ in the renal tissues were increased (P < 0.05), and the serum SOD activity and the mRNA and protein levels of Nrf2 were decreased (P < 0.05) in the model group. While the contents of Fe2+ and MDA and the mRNA and protein levels of CoL-Ⅰ and CoL-Ⅲ were decreased (P < 0.05), and the SOD activity and the levels of Nrf2 and Gpx4 were increased (P < 0.05) in the salvianolic acid B group than the model group. The treatment of salvianolic acid B+Nrf2 inhibitor increased the contents of Fe2+ and MDA and the mRNA and protein levels of CoL-Ⅰ and CoL-Ⅲ (P < 0.05), and reduced the SOD activity and the levels of Nrf2 and Gpx4 (P < 0.05) when compared with the salvianolic acid B group. Conclusion Salvianolic acid B activates the Nrf2-Gpx4 pathway and then inhibits ferroptosis to relieve RIF in UUO rats.

Background & aim: Unilateral ureteral obstruction (UUO) is a common disorder of the renal system that may cause irreversible kidney damage and depends on the duration of the obstruction and the extent of renal tissue damage and dysfunction. The aim of the present study was to determine the effect of estradiol on oxidative stress index and nitric oxide levels in unilateral ureteral obstruction in ovariectomized rats. Methods: In the present experimental study conducted in 2017, 84 rats underwent ovariectomy (180 20 20 g) and were randomly divided into 14 groups of 6. Group 1 (sham group) had no surgery and all groups 2 to 14 had unilateral ureteral obstruction and some of them were treated with medication. Thus; Groups 2-4 were sacrificed 3 days after UUO and receiving the drug (sesame oil, 0.1 and 0.5 mg / kg estradiol), respectively, group 5-7 3 days after UUO and receiving the unblocked drug (RUUO) were sacrificed the next day, groups 8-9 and 10-12 were sacrificed 1 and 3 days after RUUO and estradiol, respectively, and groups 14-13 were sacrificed 3 days after UUO and RUUO and received the drug in both models. Were. Quantitative detection tests for stable metabolites of nitric oxide and malondialdehyde in blood and tissue samples were performed using special kits. The collected data were analyzed using statistical tests and LSD test. Results: The results of the present study indicated that in the UUO model, the level of nitrite and MDA of renal tissue in the obstructive groups decreased significantly compared to the sham group (p 0.05). Conclusion: According to the obtained results, it can be stated that estradiol administration during UUO and RUUO times had no effect on nitrite and MDA levels. Although its protective effect may occur after a longer period of time than RUUO, the short-term damage caused by UUO can develop even after RUUO.

Renal fibrosis, the final pathway of chronic kidney disease, is caused by genetic and epigenetic mechanisms. Although DNA methylation has drawn attention as a developing mechanism of renal fibrosis, its contribution to renal fibrosis has not been clarified. To address this issue, the effect of zebularine, a DNA methyltransferase inhibitor, on renal inflammation and fibrosis in the murine unilateral ureteral obstruction (UUO) model was analyzed. Zebularine significantly attenuated renal tubulointerstitial fibrosis and inflammation. Zebularine decreased trichrome, α-smooth muscle actin, collagen IV, and transforming growth factor-β1 staining by 56.2%. 21.3%, 30.3%, and 29.9%, respectively, at 3 days, and by 54.6%, 41.9%, 45.9%, and 61.7%, respectively, at 7 days after UUO. Zebularine downregulated mRNA expression levels of matrix metalloproteinase (MMP)-2, MMP-9, fibronectin, and Snail1 by 48.6%. 71.4%, 31.8%, and 42.4%, respectively, at 7 days after UUO. Zebularine also suppressed the activation of nuclear factor-κB (NF-κB) and the expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, by 69.8%, 74.9%, and 69.6%, respectively, in obstructed kidneys. Furthermore, inhibiting DNA methyltransferase buttressed the nuclear expression of nuclear factor (erythroid-derived 2)-like factor 2, which upregulated downstream effectors such as catalase (1.838-fold increase at 7 days, p < 0.01), superoxide dismutase 1 (1.494-fold increase at 7 days, p < 0.05), and NAD(P)H: quinone oxidoreduate-1 (1.376-fold increase at 7 days, p < 0.05) in obstructed kidneys. Collectively, these findings suggest that inhibiting DNA methylation restores the disrupted balance between pro-inflammatory and anti-inflammatory pathways to alleviate renal inflammation and fibrosis. Therefore, these results highlight the possibility of DNA methyltransferases as therapeutic targets for treating renal inflammation and fibrosis. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to construct a microRNA (miRNA)-messenger RNA (mRNA)-transcription factor (TF) regulatory network and explore underlying molecular mechanisms, effective biomarkers, and drugs in renal fibrosis (RF). Methods: A total of six datasets were downloaded from Gene Expression Omnibus. "Limma" and "DESeq2" packages in R software and GEO2R were applied to identify the differentially expressed miRNAs and mRNAs (DEmiRNAs and DEmRNAs, respectively). The determination and verification of DEmiRNAs and DEmRNAs were performed through the integrated analysis of datasets from five mouse 7 days of unilateral ureteral obstruction datasets and one human chronic kidney disease dataset and the Human Protein Atlas (http://www. proteinatlas.org). Target mRNAs of DEmiRNAs and TFs were predicted by prediction databases and the iRegulon plugin in Cytoscape, respectively. A protein-protein interaction network was constructed using STRING, Cytoscape v3.9.1, and CytoNCA. Functional enrichment analysis was performed by DIANAmiRPath v3.0 and R package "clusterProfiler." A miRNA-mRNA-TF network was established using Cytoscape. Receiver operating characteristic (ROC) curve analysis was used to examine the diagnostic value of the key hub genes. Finally, the Comparative Toxicogenomics Database and Drug-Gene Interaction database were applied to identify potential drugs. Results: Here, 4 DEmiRNAs and 11 hub genes were determined and confirmed in five mouse datasets, of which Bckdha and Vegfa were further verified in one human dataset and HPA, respectively. Moreover, Bckdha and Vegfa were also predicted by miR-125a-3p and miR-199a-5p, respectively, in humans as in mice. The sequences of miR-125a-3p and miR-199a-5p in mice were identical to those in humans. A total of 6 TFs were predicted to regulate Bckdha and Vegfa across mice and humans; then, a miRNA-mRNA-TF regulatory network was built. Subsequently, ROC curve analysis showed that the area under the curve value of Vegfa was 0.825 (p = 0.002). Finally, enalapril was identified to target Vegfa for RF therapy. Conclusion: Pax2, Pax5, Sp1, Sp2, Sp3, and Sp4 together with Bckdhadependent miR-125a-3p/Vegfa-dependent miR-199a-5p formed a coregulatory network enabling Bckdha/Vegfa to be tightly controlled in the underlying pathogenesis of RF across mice and humans. Vegfa could act as a potential novel diagnostic marker and might be targeted by enalapril for RF therapy. [ABSTRACT FROM AUTHOR]

Hepatorenal syndrome (HRS) is a complication of cirrhosis with high morbidity and mortality. Nevertheless, the underlying mechanism involving how kidney injury aggravates the progression of cirrhosis remains unclear. This study aims to explore the role of the Toll-like receptor 4 (TLR4) signaling pathway in mediating liver and kidney injuries in HRS mice induced by unilateral ureteral obstruction (UUO) and/or bile duct ligation (BDL). Two weeks after UUO, there were no obvious pathological changes in mouse liver and the unligated side of kidney. Nevertheless, impaired liver and kidney functions, inflammatory response, and fibrosis were examined in mice after 2 wk of BDL. Compared with those of other groups, mice in the BDL + UUO group presented severer liver and kidney injuries, higher levels of inflammatory factors, and faster deposition of collagens, suggesting that kidney injuries accelerated the aggravation of HRS. Correlation analysis identified a positive correlation between expression levels of inflammatory factors and fibrotic levels. Meanwhile, TLR4 and its ligand MyD88 were upregulated during the process of liver and kidney injuries in HRS mice. Further animal experiments in transgenic TLR4-/- mice or in those treated with TAK242, a small molecule inhibitor of TLR4, showed that blocking the TLR4 signaling pathway significantly improved survival quality and survival rate in HRS mice by alleviating liver fibrosis and kidney injury. It is concluded that kidney dysfunction plays an important role in the aggravation of cirrhosis, which may be attributed to the TLR4 signaling pathway. Targeting TLR4 could be a promising therapeutic strategy for protecting both liver and kidneys in patients with HRS. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) involves progressive and irreversible loss of renal function, often causing complications and comorbidities and impairing the function of various organs. In particular, lung injury is observed not only in advanced CKD but also in early-stage CKD. The present study investigated the potential involvement of mineralocorticoid receptors (MRs) and lymphatic vessels in lung injury using a 180-day unilateral ureteral obstruction (UUO) model for CKD. Changes in lung associated with lymphangiogenesis and inflammatory were analyzed in UUO rats. The pathology of the lung tissue was observed by hematoxylin and eosin and Masson's staining. Detection of the expression of lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1), Podoplanin, vascular endothelial growth factor receptor-3 (VEGFR-3) and VEGF C to investigate lymphangiogenesis. The mRNA and protein expression levels of IL-1ß, monocyte chemotactic protein 1, tumor necrosis factor-a, nuclear factor B, phosphorylated serum and glucocorticoid-induced protein kinase-1 and MR were evaluated using western blot, reverse transcription-quantitative PCR, immunohistochemical staining and immunofluorescence staining. In the present study, long-term UUO caused kidney damage, which also led to lung inflammation, accompanied by lymphangiogenesis. However, treatment with eplerenone, an MR blocker, significantly reduced the severity of lung injury and lymphangiogenesis. Therefore, lymphangiogenesis contributed to lung fibrosis in UUO rats due to activation of MRs. In addition, transdifferentiation of lymphatic epithelial cells into myofibroblasts may also be involved in lung fibrosis. Collectively, these findings provided a potential mechanism for lung fibrosis in CKD and suggested that the use of eplerenone decreased kidney damage and lung fibrosis. [ABSTRACT FROM AUTHOR]

Fibrosis is a common final pathway of chronic kidney disease, which is a major incurable disease. Although fibrosis has an irreversible pathophysiology, the molecular and cellular mechanisms responsible remain unclear and no specific treatment is available to halt the progress of renal fibrosis. Thus, an improved understanding of the cellular mechanism involved and a novel therapeutic approach are urgently required for end-stage renal disease (ESRD). We investigated the role played by interleukin-10 (IL-10, a potent anti-inflammatory cytokine) in kidney fibrosis and the mechanisms involved using IL-10−/− mice and TCMK-1 cells (mouse kidney tubular epithelial cell line). Endoplasmic reticulum stress (ERS), apoptosis, and fibrosis in IL-10−/− mice were more severe than in IL-10+/+ mice after unilateral ureteral obstruction (UUO). The 4-Phenylbutyrate (an ERS inhibitor) treatment induced dramatic reductions in ERS, apoptosis, and fibrosis-associated factors in the renal tissues of IL-10−/− mice, compared to wild-type controls after UUO. On the other hand, in cultured TCMK-1 cells, the ERS inducers (tunicamycin, thapsigargin, or brefeldin A) enhanced the expressions of proapoptotic and profibrotic factors, though these effects were mitigated by IL-10. These results were supported by the observation that IL-10 siRNA transfection aggravated tunicamycin-induced CHOP and a-SMA expressions in TCMK-1 cells. We conclude that the anti-fibrotic effects of IL-10 were attributable to the inhibition of ERS-mediated apoptosis and believe that the results of this study improve the understanding of the cellular mechanism responsible for fibrosis and aid in the development of novel therapeutic approaches. [ABSTRACT FROM AUTHOR]

The prevalence of chronic kidney disease (CKD) is gradually rising worldwide. Patients often remain asymptomatic for an extended period, leaving them unaware of their condition, which can lead to progressing to end-stage renal disease and cause significant economic burden. Improved understanding of CKD pathogenesis can enhance early detection and facilitate advances in drug development. Here, we performed proteomic and phosphoproteomic analyses of the mouse unilateral ureteral obstruction model to explore the molecular mechanisms of chronic kidney injury. 474 significantly differentially expressed proteins and 96 significantly differentially expressed phosphoproteins were screened, respectively. Chronic kidney injury involves complex metabolic pathways such as citrate cycle and hematopoietic system in proteome, and mitochondrial oxidative phosphorylation suppression is a notable alteration. The phosphoproteomic analysis revealed a significant upregulation in epithelial mesenchymal transition and P53 pathways, with a corresponding increase in the phosphorylation of Jun at serine 73. Utilizing HK2 cells, we observed that the reduction oxidative phosphorylation was consistently associated with an augmentation in oxidative stress, which subsequently activated Jun and induced apoptosis. Proteins that act as hubs in these pathways may be candidate targets for CKD intervention. These findings contribute significantly to the current understanding of CKD and provide valuable insights for future studies. SIGNIFICANCE: Chronic kidney disease (CKD) incidence rising annually with varied etiologies, kidney often irreversibly fibrotic, the treatment options are limited and often ineffective due to deficient understanding of renal fibrosis mechanisms. Despite the extensive efforts and numerous omics studies conducted on renal fibrosis, to date, no study has been undertaken to investigate the role of phosphorylated proteins in UUO models. Previously, we performed a comprehensive transcriptome and proteome analysis based on the CKD model, but the potential alterations in the phosphoproteome were not addressed. Here, an integrated proteomic and phosphoproteomic landscape of CKD was completed, which was the the first phosphoproteomic profiles of UUO model. Phosphoproteomic profile suggests that the epithelial mesenchymal transition and P53 pathways is significantly activated in mouse models of kidney injury, and the core protein Jun played a key role in CKD. And a preliminary correlation between P-Jun and oxidative phosphorylation was found base on HK2 cells. Our work contributes to a deeper understanding of the disease characteristics and molecular mechanisms of CKD. Identifying potential CKD targets from proteome and phosphoproteome may provide valuable insights for early diagnosis and treatment of CKD., Competing Interests: Declaration of competing interest All authors declare that they have no conflicts interests. All the authors of this paper declare that we have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. There is no professional or other personal interest of any nature or kind in any product, service or company that could be construed as influencing the position presented in, or the review of the manuscript entitled., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Regardless of the underlying etiology, renal fibrosis is the final histological outcome of progressive kidney disease. Unilateral ureteral obstruction (UUO) is an ideal and reproducible experimental rodent model of renal fibrosis, which is characterized by tubulointerstitial inflammatory responses, accumulation of extracellular matrix, tubular dilatation and atrophy, and fibrosis. The magnitude of UUO-induced renal fibrosis is experimentally manipulated by the species chosen, animal age, and the severity and duration of the obstruction, while relief of the obstruction allows the animal to recover from fibrosis. The pathogenesis of renal fibrosis is complex and multifactorial and is orchestrated by activation of renin-angiotensin system (RAS), oxidative stress, inflammatory response, transforming growth factor beta 1-Smad pathway, activated myofibroblasts, cell death (apoptosis, autophagy, ferroptosis, and necroptosis), destruction of intracellular organelles, and signaling pathway. The current therapeutic approaches have limited efficacy. Inhibition of RAS and use of antioxidants and antidiabetic drugs, such as inhibitors of sodium-glucose cotransporter 2 and dipeptidyl peptidase-4, have recently gained attention as therapeutic strategies to prevent renal scarring. This literature review highlights the state of the art regarding the molecular mechanisms relevant to the management of renal fibrosis caused by UUO.

Introduction. The high prevalence of renal diseases caused by urinary tract obstruction led to the need for experimental research of compensatory and pathological processes with kidney injury. It is also of relevance to study key mechanisms providing a compensatory function of the contralateral kidney for early diagnosis, treatment, and prognosis of obstructive renal diseases.Purpose of the study. To examine epithelial nephron cells phenotype dynamics changes in contralateral kidney using unilateral ureteral obstruction experimental model.Materials and methods. Model of unilateral ureteral obstruction was established using adult rabbits. The studies were carried out on days 7, 14 and 21 of complete obstruction of the left ureter. Immunophenotyping was performed on contralateral kidney tissue samples using epithelial (cytokeratin 7, E-cadherin) and mesenchymal (vimentin, α-smooth muscle actin) markers.Results. The contralateral kidney under additional load can maintain the morphological and functional characteristics of the nephron for a long time. The first transmogrify signs in the nephron epithelium phenotype were detected by day 21 as the diffuse appearance of mesenchymal marker vimentin with unaltered visualization of epithelial phenotype markers.Conclusion. The results obtained allow us to assume that the compensatory reserve of the contralateral kidney is gradually decreasing when the duration of the obstruction increases. Thus, the likelihood of developing negative disorders increases.

Background Nesfatin-1 (NES-1), an anorexigenic peptide, was reported to have anti-inflammatory and anti-apoptotic actions in several inflammation models. Methods To elucidate potential renoprotective effects of NES-1, unilateral ureteral obstruction (UUO) was induced in male Sprague Dawley rats by ligating left ureters. The rats were injected intraperitoneally with either saline (SL) or NES-1 (10 µg/kg/day) for 7 or 14 days (n  = 8 in each group). On the 7th or 14th day, obstructed kidneys were removed for the isolation of leucocytes for flow-cytometric analysis and the assessments of biochemical and histopathological changes. Results Opposite to glutathione levels, renal myeloperoxidase activity in the SL-treated UUO group was significantly increased compared with the sham-operated group, while NES-1 treatment abolished the elevation. The percentages of CD8+/CD4+ T-lymphocytes infiltrating the obstructed kidneys were increased in the SL-treated groups but treatment with NES-1 did not prevent lymphocyte infiltration. Elevated tumour necrosis factor-alpha (TNF-α) levels in SL-treated UUO group were decreased with NES-1. Although total degeneration scores were similarly increased in all UUO groups, tubular dilatation scores were significantly increased in UUO groups and lowered by NES-1 only in the 7-day treated group. Elevated interstitial fibrosis scores in the SL-treated groups were decreased in both 7- and 14-day NES-1 treated groups, while alpha-smooth muscle actin (α-SMA) and apoptosis scores were depressed in both NES-1 treated groups. Conclusion The present data demonstrate that UUO-induced renal fibrosis is ameliorated by NES-1, which appears to involve the inhibition of neutrophil infiltration and thereby amelioration of oxidative stress and inflammation. These data suggest that NES-1 may have a regulatory role in protecting the kidneys against obstruction-induced renal injury. [ABSTRACT FROM AUTHOR]

Histone deacetylase 4 (HDAC4) has been shown to be involved in cell proliferation, differentiation, and migration and is associated with a variety of cancers. However, the role of HDAC4 in renal fibrogenesis and its mechanisms are unclear. We assessed the role of HDAC4 and possible mechanisms of fibrosis in a murine model of kidney injury induced by unilateral ureteral obstruction (UUO) using tasquinimod, a highly selective HDAC4 inhibitor, and knockout mice with depletion of HDAC4 in renal tubular cells. UUO injury resulted in increased expression of HDAC4 and fibrotic proteins fibronectin and α-smooth muscle actin, while treatment with tasquinimod or knockout of HDAC4 significantly reduced their expression. Pharmacological and genetic inhibition of HDAC4 also decreased tubular epithelial cell arrest in the G2/M phase of the cell cycle, expression of transforming growth factor-β1 and phosphorylation of Smad3, signal transducer and activator of transcription 3, and extracellular signal-regulated kinase 1/2 in the injured kidney. Moreover, tasquinimod treatment or HDAC4 deletion inhibited UUO-induced renal tubular cell injury and apoptosis as indicated by reduced expression of neutrophil gelatinase–associated lipocalin, Bax, and inhibition of caspase-3. Finally, administration of tasquinimod or knockdown of HDAC4 prevented injury-related repression of Klotho, a renoprotective protein. Our results indicate that HDAC4 is critically involved in renal tubular injury and fibrosis and suggest that HDAC4 is a potential therapeutic target for treatment of chronic fibrotic kidney disease. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in the development and progression of renal fibrosis. lncRNAs can regulate target messenger RNAs (mRNAs) by competitively binding to miRNAs. However, research on lncRNA–miRNA–mRNA interactions remains inadequate. Therefore, the aim of the present study was to investigate the possible function of lncRNA–miRNA–mRNA interactions in chronic renal fibrosis. The relationships among the expression levels of lncRNA4474, miR-615, and hepatocyte nuclear factor-1β (HNF-1β) mRNAs were determined through RNA sequencing. The biological roles of lncRNA4474, miR-615, and HNF-1β in renal fibrosis were investigated with gain-of-function and loss-of-function experiments. Results showed that miR-615 expression increased in unilateral ureteral obstruction rats, accompanied by decreased lncRNA4474 and HNF-1β mRNA expression. The overexpression of HNF-1β attenuated the development of chronic renal fibrosis, whereas HNF-1β knockdown promoted the development. Increase in HNF-1β expression downregulated and upregulated the expression levels of miR-615 and lncRNA4474, respectively, thereby attenuating renal fibrosis progression. Furthermore, lncRNA4474 promoted the expression of HNF-1β by inhibiting miR-615 expression, whereas miR-615 regulated the expression of HNF-1β and thus activated the Wnt signaling pathway. This study demonstrated that the overexpression of lncRNA4474 may attenuate fibrosis progression, accompanied by the downregulation of miR-615 and upregulation of HNF-1β. Hence, this study provides novel information that can be useful in the early diagnosis and treatment of renal fibrosis. [ABSTRACT FROM AUTHOR]

Objective(s): To explore the effect of verbascoside on renal fibrosis in unilateral ureteral obstruction (UUO) rats.Materials and Methods: Twenty Sprague-Dawley rats were randomly distributed into sham-operated, UUO, and UUO+Verbascoside groups. After two weeks of rat model construction, urine and blood samples were collected for biochemical analysis while kidney tissues were harvested for hematoxylin and eosin (H&E), Masson’s Trichrome, and immunohistochemistry staining. Pearson coefficient was used to analyze the correlation between the two proteins. Results: Verbascoside improved UUO-induced renal dysfunction as detected by decreased serum creatinine, urea nitrogen, and urinary protein excretion rate. In UUO rats, H&E staining result revealed increased total nucleated cell number, and Masson’s Trichrome staining results showed tubular interstitial fibrosis with the deposition of collagen fibrils. Besides, expressions of fibrosis-related proteins including collagen type I (COL-I), α-smooth muscle actin (a-SMA), and tissue inhibitor of metalloproteinase 2 (TIMP2) expressed higher in the UUO group. Moreover, macrophage infiltration-related factors such as CD68+, F4/80+ cells, and suppressor of cytokine signaling-3 (SOCS3) were significantly higher in the UUO group than in sham-operated rats. However, after administration with verbascoside, the accumulation of collagen fibrils and total nucleated cell numbers were mitigated. Likewise, macrophage infiltration was extenuated and fibrosis-related proteins were down-regulated in the UUO+Verbascoside rats. Correlation analysis indicated that macrophage infiltration-related markers were related to fibrosis-related factors.Conclusion: Verbascoside could alleviate renal fibrosis in UUO rats probably through ameliorating macrophage infiltration.