Ureteral Obstruction Promotes Ureteral Inflammation and Fibrosis

Shuangshi Tonglin Capsule Improves Prostate Fibrosis through Nrf2/TGF-β1 Signaling Pathways

OBJECTIVE

To investigate the effect and mechanism of Shuangshi Tonglin Capsules (SSTL) in the treatment of prostate fibrosis (PF).

METHODS

Human prostate stromal cells (WPMY-1) were used for in vitro experiments to establish PF cell models induced with estradiol (E2). The cell proliferation, migration and clonogenic capacity were determined by cell counting kit-8, scratch assay, and crystal violet staining, respectively. Sprague-Dawley rats were used for in vivo experiments. The changes in histomorphology and organ index of rat prostate by SSTL were determined. Pathologic changes and collagen deposition changes in rat prostate were observed by haematoxylin and eosin (HE) and Masson staining. Enzyme-linked immunosorbent assay kits were used to determine changes in rat PF markers fibroblast growth factor-23 (FGF-23), E2 and prostate specific antigen (PSA). Mechanistically, changes in oxidative stress indicators by SSTL were determined in WPMY-1 cells and PF rats. Then the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) and transforming growth factor-β1 (TGF-β1)/Smad pathway-related proteins as well as Nrf2 and TGF-β1 mRNA were further detected by Western blot or quantitative real-time polymerase chain reaction both in vivo and in vitro.

RESULTS

In the efficacy study, SSTL significantly reduced the proliferation, migration, and clonogenic ability of cells, improved the morphology of the glandular tissue, significantly reduced the prostate index, reduced glandular fibrous tissue and collagen deposition, and resulted in a significant decrease in the levels of FGF-23, E2 and PSA (P<0.01 or P<0.05). In the mechanistic study, SSTL ameliorated oxidative stress by significantly increasing superoxide dismutase and glutathione peroxidase levels and decreasing malondialdehyde level in WPMY-1 cells and rats (P<0.01 or P<0.05). SSTL significantly elevated the expressions of Nrf2, HO-1, NAD(P)H quinone oxidoreductase 1 (NQO-1), and Smad7 proteins in both cells and rats, and significantly decreased the expressions of TGF-β1, collagen I, α-smooth muscle actin and Smad4 proteins (P<0.01 or P<0.05). SSTL also elevated the content of Nrf2 mRNA and decreased the content of TGF-β1 mRNA in cells and rats (P<0.01 or P<0.05). The Nrf2 inhibitor ML385 was added in in vitro experiments to further validate the pathway relevance.

CONCLUSION

SSTL was effective in improving PF in vivo and in vitro, and its mechanism of action may function through the Nrf2/TGF-β1 signaling pathway.

Renal fibrosis progression following partial unilateral ureteral obstruction: mechanisms and therapeutic insights

Ureteral obstruction, a common clinical condition, is associated with various renal disorders affecting all age groups and can lead to permanent renal damage. In Partial unilateral ureteral obstruction (PUUO), increased ureteral pressure, and decreased glomerular filtration rate (GFR) in the affected kidney cause cellular and molecular abnormalities, which ultimately lead to renal fibrosis if untreated. While removing the obstruction (RUUO) is essential to prevent long-term damage, additional therapeutic approaches may be necessary to fully restore kidney function. The PUUO model is used to induce renal fibrosis, primarily characterized by tubular injury resulting from obstructed urine flow. PUUO in rodents can simulate human chronic obstructive nephropathy at an accelerated rate. Although alleviating the obstruction can reduce immediate symptoms, it is often insufficient to reverse established fibrosis, emphasizing the need for adjunctive therapies. The renal response to RUUO depends on factors like the obstruction's duration and severity, as well as the contralateral kidney's functional state.

Evaluation of serum galectin-3 concentrations in healthy cats and in cats with ureteral obstruction

OBJECTIVES

Serum galectin-3 (sGal-3) is a protein present in renal tubules and increases in experimental rodent models of acute kidney injury. The aim of this study was to compare sGal-3 concentrations in healthy cats and cats with ureteral obstruction (UO).

METHODS

This was a retrospective study. Banked serum was used for sGal-3 evaluations in 15 healthy control cats and 22 cats with UO. For the control cats, creatinine and symmetric dimethylarginine were within reference intervals and ultrasound showed minimal to no kidney changes. A feline-specific sGal-3 ELISA was used to determine sGal-3 concentrations. Samples were analyzed in duplicate, and results were included if the coefficient of variation between samples was <20%. Shapiro-Wilk testing was used to evaluate for normality and parametric statistics were performed. P <0.05 was considered significant.

RESULTS

Mean (±SD) sGal-3 was lower in healthy cats (274.3 ± 146.5 pg/ml) than in cats with UO (707.7 ± 223.3 pg/ml; P <0.0001). There was no difference in sGal-3 concentrations between cats with unilateral or bilateral UO (P = 0.24) and no correlation between sGal-3 and creatinine, body weight or age. With a cutoff of 500 pg/ml, sGal-3 had a sensitivity of 86% (95% confidence interval [CI] 0.67-0.95) and specificity of 100% (95% CI 0.79-1.00) for differentiating cats with UO from healthy cats.

CONCLUSIONS AND RELEVANCE

An early diagnosis of UO is critical, given its associated morbidity and mortality. Given the differences in sGal-3 concentrations in healthy cats and those with UO in this study, sGal-3 shows potential for an early UO diagnosis; however, further research is needed.

Imperatorin ameliorates ferroptotic cell death, inflammation, and renal fibrosis in a unilateral ureteral obstruction mouse model

BACKGROUND

Imperatorin is a naturally occurring furocoumarin derivative found in traditional Chinese medicine Angelica dahurica for its anticancer, antihypertensive, and antidiabetic properties. Chronic kidney disease (CKD) is a global health issue, characterized by a high prevalence, significant morbidity and mortality, and a range of related complications.

OBJECTIVE

This study aims to investigate the protective effects of imperatorin treatment and the specific underlying mechanisms in progressive CKD.

METHODS

Imperatorin was orally administrated for 14 consecutive days to mice with unilateral ureteral obstruction (UUO) to investigate the renal pathological alternations, pro-inflammatory mediators, antioxidant response, and ferroptotic death signaling. Imperatorin was also tested in the erastin-induced injury of renal proximal tubular cells (NRK-52E). Cell viability, ferroptosis protein markers, erastin-induced oxidative stress, and lipid peroxidation were assessed.

RESULTS

In vivo, imperatorin treatment alleviated kidney histology alternations and attenuated the protein expression of fibrotic markers. Furthermore, imperatorin administration reduced inflammatory cell infiltration, and alleviated the oxidative stress burden by downregulating protein markers such as catalase, superoxide dismutase 2 (SOD-2), NADPH oxidase 4 (NOX-4), and thioredoxin reductase 1 (Trxr-1). It also mitigated ferroptosis markers such as glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11/cystine transporter (SLC7A11/xCT), and transferrin receptor 1 (TFR-1), and attenuated renal cell apoptosis. In vitro, imperatorin treatment effectively decreased erastin-induced feroptotic cell death, restored the antioxidant enzyme levels, and mitigated lipid peroxidation as well as the expression of ferroptosis-related markers (XCT, GPX4, and p-p53) in a dose-dependent manner.

CONCLUSION

Our finding demonstrated for the first time, that imperatorin treatment holds therapeutic potential in a UUO mouse model of CKD and inhibits the erastin-induced oxidative stress, ferroptosis, and subsequent lipid peroxidation in vitro. This highlights the potential of imperatorin as a future therapeutic target for ferroptosis to improve the progression of CKD.

Drugs to affect the smooth musculature of the human ureter - an update with integrated information from basic science to the use in medical expulsion therapy (MET)

PURPOSE

Urolithiasis and symptomatic ureterolithiasis represent diseases known to be on the increase in most westernized countries. The present article aims to give an overview on some drug principles assumed to target signalling systems involved in modulating ureter smooth muscle contractility and to present background to their potential use or prospects in ureter stone disease.

METHODS

The article reviews drugs that have been evaluated over the last decades in vitro, in vivo and/or in clinical settings with regard to their properties to achieve spontaneous passage of (distal) ureteral stones and relieve colic pain. Among these drugs are alpha- and beta-adrenoceptor antagonists, calcium channel blocking agents, Rho kinase inhibitors, nitric oxide (NO) donor drugs, selective inhibitors of cyclic nucleotide phosphodiesterase enzymes (PDEs), as well as potassium channel openers.

RESULTS

Based on the recent scientific information on agents targeting different pathways, antagonists of alpha 1-adrenoceptors, inhibitors of the PDE isoenzymes PDE4 and PDE5 (affecting cyclic AMP- or NO/cyclic GMP-mediated signals that facilitate relaxation of ureter smooth muscle), as well as the combination of certain drugs (for example, PDE5/PDE4 inhibitor plus alpha 1-AR antagonist) seem to be intriguing pharmacological approaches to medical expulsion therapy (MET) in the overall population of patients.

CONCLUSION

While NO donors, calcium channel antagonists and potassium channel openers may be limited for further development for medical expulsion therapy (MET) due to their systemic effects and a lack of effect on stone clearance, Rho kinase inhibitors should be explored further as a future pharmacological principle in ureteral stone disease.

Evaluation of postoperative renal function in infants with congenital hydronephrosis using ROI from ultrasound technique in renography

The aim of this study was to assess the efficacy of GFR measured using ROI from ultrasound technique in diuretic renography for evaluating postoperative outcomes in infants under one year old with congenital hydronephrosis. A retrospective analysis was conducted on thirty infants who underwent abdominal ultrasound and diuretic renography before and after surgery, obtaining preoperative and postoperative gGFRs and uGFRs (measured using ROI from ultrasound technique) determined using the Gates method and ultrasonic-assisted drawing ROI technique, respectively. A comparative study was performed on total GFR as well as individual kidney GFR before and after intervention. The preoperative and postoperative total and single uGFRs were significantly lower than gGFRs, while the postoperative total and single renal function, along with relative renal function in the hydronephrotic kidneys, were also significantly higher than the preoperative results (p < 0.05). Among 30 infants, 23 cases exhibited substantial recovery of renal function in their hydronephrotic kidneys after surgery, 2 cases did not show significant improvement, while 5 cases continued to experience deterioration in renal function. The GFR measured using ROI from ultrasound technique provides a more accurate assessment of renal function changes before and after surgery in infants under one year old with congenital hydronephrosis, facilitating an effective evaluation of postoperative treatment efficacy.

CXCL5 inhibition ameliorates acute kidney injury and prevents the progression from acute kidney injury to chronic kidney disease

Acute kidney injury (AKI) increases the risk of chronic kidney disease (CKD). CXC motif chemokine ligand 5 (CXCL5) is up-regulated in kidney diseases. We aimed to investigate the direct effect of CXCL5 on the pathology of AKI. Serum and renal expression of CXCL5 were increased in animals with renal ischemia-reperfusion injury or unilateral ureteral obstruction. CXCL5-knockout mice exhibited reduced systemic oxidative stress and preserved renal function in the acute and chronic phases of AKI, as evidenced by reductions in serum BUN and creatinine levels, the urinary albumin-to-creatinine ratio, and the kidney-to-body weight ratio. CXCL5-knockout mice improved AKI-induced tubular injury and fibrosis, reduced renal macrophage infiltration, and reduced expression of NADPH oxidase and inflammatory and fibrotic proteins. CXCL5 activated p47 to up-regulate ROS generation and induce cellular damages through CXCR2. CXCL5 knockdown exerted antioxidative, anti-inflammatory, anti-fibrotic, and anti-apoptotic effects on hypoxia-reoxygenation-stimulated renal proximal tubular epithelial cells. Clinical data indicated elevated circulating and renal CXCL5 in CKD patients, and renal CXCL5 was correlated with increased renal fibrosis and decreased estimated glomerular filtration rate. Altogether, CXCL5 levels increased in experimental AKI and clinical CKD, and in vivo and in vitro CXCL5 inhibition may reduce acute tubular injury and prevent the subsequent progression from AKI to CKD.

Applying urinary ultrasound to predict the risk of spontaneous ureteral stone passage: a retrospective cohort study

BACKGROUND

To assess the value of urological ultrasound in predicting the risk of spontaneous passage of ureteral stones.

METHODS

Clinical and ultrasound data were collected consecutively from patients receiving conservative treatment for ureteral stones, and the outcome of spontaneous passage was followed up for 1 month. Ultrasound variables independently associated with the risk of spontaneous stone passage were screened. A logistic regression prediction model was constructed based on the independent risk factors, and the discriminative efficacy and clinical utility of the prediction model in inferring the risk of spontaneous passing were assessed by the receiver operating characteristic (ROC) curve, calibration curve and clinical decision curve.

RESULTS

A total of 163 patients undergoing conservative treatment for ureteral stones were included in the study, with a mean age of 45.95 ± 13.01 years. Among them, 47 cases (28.83%) experienced failure of spontaneous stone passage. Multivariable analysis revealed that stone length (OR: 2.622, P = 0.027), distal stone location (OR: 0.219, P = 0.003), and ureteral jetting frequency (OR: 6.541, P < 0.001) were independent risk factors for spontaneous stone passage. A prediction model incorporating stone length, stone location, and affected ureteral jetting frequency was developed to assess the risk of spontaneous stone passage. The area under the ROC curve was 0.814 (95% CI: 0.747-0.882), indicating good discriminatory power. The prediction model also demonstrated favorable net clinical benefit.

CONCLUSION

A prediction model based on ultrasound-derived stone length, location, and ureteral jetting frequency can accurately evaluate the risk of spontaneous stone passage in patients with ureteral stones, providing a basis for optimizing the clinical decision-making on ureteral stones, and has reliable clinical application value.

Platelet membrane biomimetic nanoparticle-targeted delivery of TGF-β1 siRNA attenuates renal inflammation and fibrosis

The progression of renal fibrosis to end-stage renal disease (ESRD) is significantly influenced by transforming growth factor-beta (TGF-beta) signal pathway. This study aimed to develop nanoparticles (PMVs@PLGA complexes) with platelet membrane camouflage, which can transport interfering RNA to target and regulate the TGF-β1 pathway in damaged renal tissues. The aim is to reduce the severity of acute kidney injury and to reduce fibrosis in chronic kidney disease. Hence, we formulated PMVs@TGF-β1-siRNA NP complexes and employed them for both in vitro and in vivo therapy. From the experimental findings we know that the PMVs@siRNA NPs could effectively target the kidneys in unilateral ureteral obstruction (UUO) mice and ischemia/reperfusion injury (I/R) mice. In animal models of treatment, PMVs@siRNA NP complexes effectively decreased the expression of TGF-β1 and mitigated inflammation and fibrosis in the kidneys by blocking the TGF-β1/Smad3 pathway. Therefore, these PMVs@siRNA NP complexes can serve as a promising biological delivery system for treating kidney diseases.

Migration of varicocele coil leading to ureteral obstruction and hydronephrosis: A case report

BACKGROUND

Varicocele embolization, a minimally invasive treatment for symptomatic varicoceles, carries a rare risk of complications like ureteral obstruction and hydronephrosis. This case report documents such a case to raise awareness of these potential complications and showcase minimally invasive surgical management as a successful solution.

CASE SUMMARY

A 35-year-old male presented with flank pain and hematuria following varicocele embolization. Imaging confirmed left ureteral obstruction and hydronephrosis. Laparoscopic ureterolysis successfully removed the embolization coil and repaired the ureter, resolving the patient's symptoms. Follow-up at six months and two years showed sustained improvement.

CONCLUSION

Minimally invasive surgery offers an effective treatment option for rare complications like ureteral obstruction arising from varicocele embolization.

Abnormal urodynamic changes in post-upper urinary tract dysfunction in ureteral obstruction rat models

Objects: This study investigated changes in upper urinary tract urodynamics (UUTU) after upper urinary tract dysfunction (UUTD). Methods: The UUTD model was induced through unilateral ureteral obstruction. To measure the renal pelvis volume, and resting pressure. Ureteral electromyography (EMG) and in situ ureteral constriction experiments were performed. Ureteral tissue was obtained for HE and masson staining, IF staining and IHC research to explore the distribution of Piezo1, and the expression of Piezo1 was studied using Western blotting. Results: The study showed that the renal pelvis volumes and the renal pelvis resting pressures gradually increased post surgery in the experimental group. The degree of ureteral tissue edema, cell necrosis and fibrosis gradually increased. The maximum contraction force and frequency of ureter in the experimental group post surgery were significantly higher than in the sham group. Western blotting showed that the expression intensity of Piezo1 gradually increased and was significantly higher than in the sham group. Further analysis of each sub-layer of the ureter revealed that Piezo1 was highly expressed in the urothelium layer, followed by the suburothelium layer, and had low expression in the smooth muscle cell layer. Conclusion: The study observed that morphological and electrophysiological changes in the upper urinary tract may be important mechanisms of abnormal UUTU. Increased expression of the Piezo1 may be a new molecular mechanism of abnormal urodynamics after UUTD.

Development of a new scoring system predicting medical expulsive therapy success on 4-10 mm distal ureteral stones: medical expulsive therapy stone score (METSS)

Ureteral stone passage by using medical expulsive therapy (MET) are affected by numerous radiological and clinical parameters. We aimed to construct a scoring system, which would be based on clinical and computed tomography (CT)-derived data, to predict the success of the MET approach. 186 patients presenting to urology clinic or emergency department with unilateral single 4-10 mm distal ureteral stone and who had MET were included. All patients were divided into two groups as the MET-successful group and the MET-unsuccessful group. The success rate of MET was 67.2%. Stone size ≥ 6.5 mm, stone density > 1078 HU, ureteral wall thickness (UWT) > 2.31 mm, ureteral diameter (UD) > 9.24 mm, presence of periureteral stranding (PUS) and presence of diabetes mellitus (DM) were stated as the independent risk factors. Based on the regression coefficients on multivariate logistic regression analysis, 1 point for stone size > 6.5 mm, 2 points for stone density > 1078 HU, 2 points for UWT > 2.31 mm, 3 points for UD > 9.24 mm, 1 point for presence of PUS and 1 point for presence of DM were assigned to patients for each risk factor. Higher medical expulsive therapy stone score (METSS) indicated lower MET success. All patients were classified into three risk groups according to METSS: low risk (0-3 points; success percentage: 92.8%); intermediate risk (4-5 points; success percentage: 60.4%) and high risk (6-10 points; success percentage: 8.3%). The METSS seems to separate successfully the patients with a favorable or adverse constellation of factors.

A Comparison of Boron Supplement and Tamsulosin as Medical Expulsive Therapy for Urinary Stones After Extracorporeal Shock Wave Lithotripsy: a Randomized Controlled Clinical Trial

Treatment with alpha-blockers has been used in many studies to facilitate stone clearance after extra-corporeal shock wave lithotripsy (ESWL), based on mediating ureteral wall relaxation. Ureteral wall edema is another barrier against the stone passage. We aimed to compare the effectiveness of boron supplement (due to its anti-inflammatory effect) and tamsulosin in the passage of stone fragments after ESWL. Eligible patients after ESWL were randomly assigned to two groups and were treated with boron supplement (10 mg/BD) or tamsulosin (0.4 mg per night) for 2 weeks. The primary outcome was the stone expulsion rate according to the remained fragmented stone burden. The secondary outcomes were the time of stone clearance, pain intensity, drug side effects, and the need for auxiliary procedures. In this randomized control trial, 200 eligible patients were treated with boron supplement or tamsulosin. Finally, 89 and 81 patients in the two groups completed the study, respectively. The expulsion rate was 46.6% in the boron and 38.7% in the tamsulosin group, which there was no statistically significant difference between the two groups (p = 0.003), as well as the time of stone clearance (7.47 ± 22.4 vs 6.52 ± 18.45, days, p = 0.648, respectively), after 2-week follow-up. Moreover, pain intensity was the same in both groups. No Significant side effects were reported in the two groups. Boron supplement could be effective as adjuvant medical expulsive therapy after ESWL with no significant side effects in short-term follow-up. Iranian Clinical Trial Registration number and date of registration: IRCT20191026045244N3, 07/29/2020.

A novel in vivo model of ureteral fibrosis induced by calcium oxalate beads in C57BL/6J mice

The global incidence of ureteroliths in humans is increasing, particularly posing a problem in developed countries. The most common stone type is calcium oxalate, which is associated with a high recurrence rate. In veterinary medicine, stones are the most common cause of ureteral obstruction in cats, accounting for 72-87% of cases. In cats, stones cause irreversible ureteral damage, necessitating stone treatment as well as ureteral therapy. However, the mechanisms underlying the ureteral damage caused by stones remain unclear. Therefore, this study aimed to create a mouse model suitable for studying the ureteral fibrosis caused by oxalate stones by artificially embedding calcium oxalate in the ureter. Pathological tissue analysis was used to compare normal ureters without ligation and ureters with sham or oxalate bead implantation. The ureters of the sham and oxalate bead groups showed granulation tissue formation, transitional epithelium exfoliation, and densely packed connective tissue in the proprietary and muscle layer regions. Particularly in the oxalate bead group, infiltration of degenerated neutrophils, presence of foreign body giant cells, and hyperplasia of the transitional epithelium were observed. The proportion of fibrosis was higher in the oxalate group than in the sham group. Overall, this mouse model created using oxalate bead implantation has the potential to efficiently induce ureteral obstruction. This mouse model is expected to be used for elucidating the molecular mechanisms of ureteral fibrosis and evaluating therapeutic drugs in future.

Indwelling stents cause severe inflammation and fibrosis of the ureter via urothelial-mesenchymal transition

To explore the pathways and mechanisms driving inflammation and fibrosis in stented ureters. In total, six healthy female pigs underwent cystoscopic unilateral ureteral stent insertion (6 Fr). After 14 days indwelling time, ureteral tissue was harvested in three pigs, while the remaining three pigs had their stents removed, and were recovered for 7 days. Three separate pigs served as controls. Tissue from stented and contralateral ureters was analysed histologically to evaluate tissue remodelling and classify the degree of inflammation and fibrosis, while genome, proteome and immunohistochemistry analysis was performed to assess changes at the transcriptional and translational levels. Finally, immunofluorescence was used to characterize the cell composition of the immune response and pathways involved in inflammation and fibrosis. Statistical analysis was performed using GraphPad Prism and RStudio for Welch ANOVA, Kruskal-Wallis and Dunnett's T3 multiple comparison test. Stents cause significant inflammation and fibrosis of ureters. Gene set enrichment analysis confirmed fibrotic changes and tissue proliferation and suggests that epithelial-mesenchymal transition is a driver of fibrosis. Moreover, IL-6/JAK/STAT and TNFα via NF-κB signalling might contribute to chronic inflammation promoting a profibrotic environment. Immunostaining confirmed epithelial-mesenchymal transition in the urothelium and NF-κB expression in ureters stented for 14 days. Tissue alterations do not fully recover after 7 days. Histological evaluation showed that contralateral, unstented ureters are affected by mild inflammation. Our study showed that stenting has a significant impact on the ureter. Chronic inflammation and epithelial-mesenchymal transition are drivers of fibrosis, potentially impairing ureteral functionality in the long term. Furthermore, we observed mild inflammation in contralateral, unstented ureters.