Tubular Dilatation Research Articles

#2592 Tubular cell polyploidy is involved in kidney compensatory hypertrophy

Abstract Background and Aims Chronic kidney disease (CKD) affects more than 10% of the population and it is associated with high risk of death for cardiovascular causes or progression towards end stage kidney disease (ESKD) requiring dialysis or kidney transplantation. CKD is characterized by progressive loss of nephrons, with consequent structural degeneration and fibrosis. Nephron number is established during prenatal kidney development and cannot increase. Consequently, following a reduction in kidney mass or in condition of altered metabolic demands, the remaining nephrons undergo compensatory hypertrophy. Compensatory hypertrophy results in increased functional output and has been observed in the absence of direct tissue injury after nephrectomy. Recently, we have identified a previously unknown mechanism of cellular adaptation: polyploidization of tubular epithelial cells (TC), and demonstrated that this is the essential mediator of kidney hypertrophy after acute kidney injury (AKI). Here, we hypothesize that TC polyploidy is involved in compensatory hypertrophy following nephrectomy. Method Polyploid TC are characterized by an increased DNA content in the absence of cell division. To discriminate polyploid cells from actively proliferating cells, we employed a series of in vitro and in vivo transgenic models based on the Fluorescence Ubiquitin Cell Cycle Indicator (FUCCI2aR) technology. Nephrectomy was performed by removing the left kidney and mice were sacrificed at different days after uni- Nephrectomy (Nfx). Cytofluorimetric techniques were employed to characterize a subpopulation of polyploid TC and histology investigation was employed analyze fibrosis development. These results were further corroborated by single cell RNA-sequencing (scRNA-seq) analyses in vitro and in vivo. Results Employing mice that express the FUCCI2aR reported under the Pax8 promoter (which marks all TC), we found that TC polyploidy increases immediately after uni-Nfx. This was accompanied by an increased kidney to body mass ratio with a maximum peaks 3 days afterwards. Importantly, after uni-Nfx, YAP1 expression and nuclei localization (i.e., implying pathway activation) was exponentially increased, suggesting that the same mechanism that drives TC polyploidy after AKI controls TC polyploidization response after uni-Nfx. However, unlike in AKI, polyploidy after nephrectomy was not accompanied by structural alterations as shown by PAS and Masson's trichrome staining. Conversely, after uni-Nfx YAP1 knock-out mice, that are unable to undergo rapid polyploidization, displayed an impaired kidney function in the long term, characterized by extensive tubular dilations. Conclusion Polyploidization of TC mediates compensatory hypertrophy following nephrectomy via YAP1 activation

#2884 Dose-dependent EGR1 expression in the rat renal medulla after chronic NSAID treatment

Abstract Background and Aims Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in clinical medicine. Chronic use of NSAIDs is associated with reduced renal medullary blood flow, potentially causing severe and irreversible damage including papilla necrosis. We have previously demonstrated that chronic hyperosmolar injury in the renal medulla induces the expression of pro-fibrotic TGF-beta1 and EGR1. However, the impact of chronic NSAID treatment on EGR1 and pro-fibrotic factors in renal cortex and medulla remains unexplored. Thus, we aimed to analyze the effects of chronic NSAID treatment in the rat renal medulla. Method Male Wistar rats (250-260 grams) were orally treated twice daily for two weeks with various NSAIDs: indomethacin (IND, 2 mg/kg), naproxen (NAP, 10 or 20 mg/kg), celecoxib (CEL, 10 and 30 mg/kg), or vehicle (1% hydroxyethylcellulose). Left kidney was removed for histology and immunohistochemistry, the right kidney medulla was separated for mRNA analysis. Kruskal-Wallis test was performed for statistical analysis. Results NSAIDs caused significant tubular dilatation in all treated groups except IND. CEL (10, 30 mg/kg) and NAP (10 mg/kg) markedly increased epithelial atrophy. NAP 10 and 30 mg/kg induced a dose-dependent, 2-fold and 3.2-fold TIMP1 mRNA over-expression, respectively. Only NAP 20 mg/kg induced significant, 2.5-fold EGR1 mRNA expression. Both IND and CEL increased a 2-fold EGR1 protein expression in the medulla, but NAP induced a dose-dependent 5- and 10-fold increase of EGR1 protein. Conclusion Our study show that EGR1 and TIMP1 might play an important role in the development of NSAID induced tissue injury in the rat renal medulla. Further studies are needed to shed light on the molecular pathogenesis.

#1110 The AHR antagonist CH223191 alleviates kidney injury and renal fibrosis in adenine-induced chronic kidney disease

Abstract Background and Aims The aryl hydrocarbon receptor (AhR) is a transcription factor that can be activated by a variety of endogenous and exogenous ligands, and is involved in varieties of biological processes. It has been confirmed that the expression of AhR in kidney is elevated in chronic kidney disease (CKD). However, the specific role of AhR signaling pathway in CKD and its molecular mechanism remain unclear. This study aims to investigate the role and underlying mechanism of AhR in CKD, providing potential targets for the treatment of CKD. Method Male C57/B6L mice were randomly divided into control group, model group and treatment group. The model group was fed 0.2% adenine diet for 14 days to establish CKD model, while the treatment group was treated with AhR antagonist CH223191. AhR agonist kynurenine and antagonist CH223191 was applied in mouse tubular epithelial (TCMK-1) cells to investigate the underlying mechanisms of AhR in vitro. The renal function, histological changes and renal fibrosis in mice were evaluated to explore the role of AhR in adenine-induced CKD. Histological changes were evaluated by PAS and MASSON stainings, immunohistochemistry and immunofluorescence. Western blot and qPCR were used to measure protein/gene transcription levels. Results The levels of serum creatinine (p < 0.0001) and urea nitrogen (p < 0.0001) in the model group were significantly increased, with obvious renal tubule dilation and renal fibrosis by PAS and MASSON staining. CH223191 treatment significantly reduced serum creatinine (p=0.0012) and urea nitrogen ( < 0.0001) levels in mice, and alleviated renal fibrosis histologically. Q-PCR and Western-Blot results showed that the renal expression level of AhR in the treatment group was decreased, while the expression levels of fibronectin (Fn) (p < 0.0001), α-smooth muscle actin (α-SMA) (p < 0.0001), type I collagen (p=0.0007) and transforming growth factor-β (TGF-b) (p=0.0027) were significantly decreased. In addition, the expression levels of N-GAL (p < 0.0001) and KIM-1 ( < 0.0001) molecular markers associated with kidney injury were reduced, suggesting that inhibiting AhR expression in vivo can reduce adenine-mediated kidney injury and renal fibrosis in CKD. In vitro experiments indicated that kynurenic acid could induce the expression of AhR and AhR downstream regulatory gene CYP1b1 and upregulated fibrosis-related genes in tubular epithelial cells, while CH223191 treatment downregulated the fibrosis-related genes in tubular epithelial cells. Conclusion AhR mediates renal injury and renal fibrosis in adenine-induced CKD mice. AhR antagonist CH223191 exerts a renal protective effect by reducing the expression of AhR in renal tubular epithelial cells, thereby alleviating renal injury and renal fibrosis.

Magnoflorine Ameliorates Chronic Kidney Disease in High-Fat and High-Fructose-Fed Mice by Promoting Parkin/PINK1-Dependent Mitophagy to Inhibit NLRP3/Caspase-1-Mediated Pyroptosis.

Excessive intake of fat and fructose in Western diets has been confirmed to induce renal lipotoxicity, thereby driving the progression of chronic kidney disease (CKD). This study was conducted to evaluate the efficacy of magnoflorine in a CKD mouse model subjected to high-fat and high-fructose diets. Our results demonstrated that magnoflorine treatment ameliorated abnormal renal function indices (serum creatinine, urea nitrogen, uric acid, and urine protein) in high-fat- and high-fructose-fed mice. Histologically, renal tubular cell steatosis, lipid deposition, tubular dilatation, and glomerular fibrosis were significantly reduced by the magnoflorine treatment in these mice. Mechanistically, magnoflorine promotes Parkin/PINK1-mediated mitophagy, thereby inhibiting NLRP3/Caspase-1-mediated pyroptosis. Consistent findings were observed in the palmitic acid-incubated HK-2 cell model. Notably, both silencing of Parkin and the use of a mitophagy inhibitor reversed the inhibitory effect of magnoflorine on NLRP3 inflammasome activation in vitro. Therefore, the present study provides compelling evidence that magnoflorine improves renal injury in high-fat- and high-fructose-fed mice by promoting Parkin/PINK1-dependent mitophagy to inhibit NLRP3 inflammasome activation and pyroptosis. Our findings suggest that dietary supplementation with magnoflorine and magnoflorine-rich foods (such as magnolia) might be an effective strategy for the prevention of CKD.

The renoprotective effect of Tibolone in sepsis-induced acute kidney injury.

Sepsis-induced acute kidney injury (AKI) remains a major challenge in intensive care, contributing significantly to morbidity and mortality. Tibolone, known for its neuroprotective and hormonal properties, has not been explored for its potential in AKI management. This study investigates the protective effects of Tibolone and its underlying mechanisms involving Sirtuin-1 (SIRT1) and Yes-Associated Protein (YAP) in a rat sepsis model. Thirty-six female Wistar albino rats underwent cecal ligation and puncture (CLP) to induce sepsis. They were randomly assigned to control, CLP+Saline, and CLP+Tibolone groups. Tibolone was administered intraperitoneally. Biomarkers, including Sirtuin (SIRT1), Yes-associated protein (YAP), Tumor necrosis factor (TNF-α), High mobility group box 1 (HMGB1), malondialdehyde (MDA), creatinine, and urea, were assessed. Histopathological examination evaluated renal damage. Tibolone administration significantly reduced plasma TNF-α, HMGB1, MDA, creatinine, and urea levels compared to the CLP+Saline group. Moreover, Tibolone elevated SIRT1 and YAP levels in kidney tissues. Histopathological examination demonstrated a significant decrease in tubular epithelial necrosis, luminal debris, dilatation, hemorrhage, and interstitial inflammation in Tibolone-treated rats. This study unveils the protective role of Tibolone against sepsis-induced AKI in rats. The improvements in inflammatory and oxidative biomarkers and histological evidence suggest Tibolone's potential as a therapeutic intervention in sepsis-associated kidney injury. The upregulation of SIRT1 and YAP indicates their involvement in Tibolone's renoprotective mechanisms. Further investigations are warranted to explore Tibolone's translational potential in human sepsis-induced AKI.

Kidney Measurement and Glomerular Filtration Rate Evolution in Children with Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by renal tubular cystic dilatations. The cysts can develop anywhere along the nephron, and over time the cystic dilatation leads to kidney enlargement. On the other hand, the cysts begin to reduce the number of functional nephrons as a consequence of cystic expansion that further contributes to the decline in renal function over the years. The pressure exerted by the dilated cysts leads to compensatory mechanisms that further contribute to the decline in renal function. These structural changes are responsible of glomerular hyperfiltration states, albuminuria, proteinuria, and hematuria. However, the presentation of ADPKD varies in children, from a completely asymptomatic child with incidental ultrasound detection of cysts to a rapidly progressive disease. There have been reports of early onset ADPKD in children younger than 2 years that showed a more rapid decline in renal function. ADPKD is caused by a mutation in PKD1 and PKD2 genes. Today, the PKD1 gene mutation seems to account for up to 85% of the cases worldwide, and it is associated with worse renal outcomes. Individuals with PKD2 gene mutation seem to present a milder form of the disease, with a more delayed onset of end-stage kidney disease. The cardinal sign of ADPKD is the presence of renal cysts during renal ultrasound. The current guidelines provide clinicians the recommendations for genetic testing in children with a positive family history. Given that the vast majority of children with ADPKD present with normal or supra-normal kidney function, we explored the glomerular filtration rates dynamics and the renal ultrasound-adjusted percentiles. In total, 14 out of 16 patients had kidney percentiles over 90%. The gene mutations were equally distributed among our cohort. In addition, we compared the modified Schwartz formula to the quadratic equation after adjusting the serum creatinine measurements. It seems that even though children with ADPKD have enlarged kidneys, the renal function is more likely normal or near normal when the quadratic estimation of glomerular filtration rate is used (qGFR tended to be lower, 111.95 ± 12.43 mL/min/1.73 m2 when compared to Schwartz eGFR 126.28 ± 33.07 mL/min/1.73 m2, p = 0.14). Also, when the quadratic equation was employed, not even a single patient reached the glomerular hyperfiltration threshold. The quadratic formula showed that glomerular filtration rates are linear or slightly decreasing after 1 year of follow-up (quadratic ΔeGFR = -0.32 ± 5.78 mL/min/1.73 m2), as opposed to the Schwartz formula that can falsely classify children in a hyperfiltration state (ΔeGFR = 7.51 ± 19.46 mL/min/1.73 m2), p = 0.019.

A compared histopathological study on kidneys and eye bulbs in distinct clinical presentations of canine leishmaniasis by Leishmania infantum.

Canine leishmaniasis (CanL) caused byLeishmania infantumcommonly progresses with renal and ophthalmic lesions associated with active systemic disease. As chronic inflammation related to immune complex deposits is a pathophysiological factor in the development of both glomerulonephritis and uveitis, we aimed to evaluate renal and ocular histopathological lesions and analyze whether they were related to each other and the clinical degree of the disease. For that, we evaluated 15 dogs from CanL-endemic areas.L. infantumPCR-positive dogs were studied according to disease severity into two different groups: Group-1 (G1) had data from seven dogs with mild to moderate CanL and no history of treatment, and G2 was formed with eight dogs with severe to terminal disease that had not responded to CanL treatment. Histopathological analysis of kidneys showed higher frequencies and intensities of glomerular basement membrane thickening (p = 0.026), deposits in glomeruli (p = 0.016), epithelial necrosis (p = 0.020), tubular dilatation (p = 0.003) and interstitial fibrosis (p = 0.04) in G2 dogs than in G1 dogs. Surprisingly, the histopathology of eye bulbs showed a higher frequency and intensity of retinitis (p = 0.019) in G1 dogs than in G2 dogs. The comparative analysis showed that there was no correspondence between histopathological findings in kidneys versus eyes in milder or more severe CanL. Our findings suggested that (1) clinically undetectable eye alterations can be more precocious than those in kidneys in the development of CanL, and (2) the lower frequency of eye lesions and higher frequency of renal lesions in dogs with terminal disease even after treatment indicate that therapy may have been effective in reducing CanL-associated ophthalmic disease but not proportionally in reducing kidney disease.

Physiological Functions of Aquaporin-3 in Mediating Water and Solutes

Aquaporins (AQP), are a family of membrane channel proteins that facilitate the transmembrane diffusion of water and some small non-charged solutes such as glycerol and urea by osmosis or solute gradient. AQP3, an aquaglyceroporin, is expressed in the kidney, skin, and testes, etc. Mice lacking AQP3 have symptoms of diabetes insipidus. In addition, the absence of AQP3 leads to dry skin in mice. AQP4 is permeable to water only. To understand the specific function of the water permeability and small solute transport mediated by AQP3, we generated AQP3 knock-out (AQP3 KO) mice and AQP4 knock-in mice (AQP4 KI) with AQP4 replacing AQP3 in situ. In the basal condition, knock-out of AQP3 in mice led to increased urine volume, decreased urine osmolality and tubule dilation. Interestingly, in AQP4 KI mice, these phenomena were reversed, showing improved urine concentration and tubular morphology. However, there was no significant difference in non-urea solute concentrations between both genotypes. Subsequently, we conducted acute urea loading tests and high-protein diet experiments to further increase the production and excretion of urea in mice. The experimental results showed that both urea loading and high-protein diet had little impact on urine osmolality and urinary urea concentration in AQP3 KO mice. But the urine osmolality and urinary urea concentration in AQP4 KI mice were altered by exogenous administration of urea. Our data indicates that the absence of AQP3 prevents urea accumulation in the kidney, disrupting urine concentration mechanism. The knock-in of AQP4 can restore AQP3 mediated water channel function and help to regulate the urine concentration ability. The water permeability, other than solute transport, of AQP3 plays important role in urine concentrating mechanism. AQP3 KO mice exhibited significant epidermal thickening, excessive keratinization, decreased skin hydration and elasticity. The replacement of AQP4 in situ did not improve these phenomena, indicating that solute transport mediated by AQP3 may play a role in maintaining normal skin function. Therefore, we constructed a mouse model of psoriasis induced by imiquimod (IMQ). It was found that AQP3 expression was reduced in the lesional skin of wildtype (WT) mice, while AQP3 KO mice and AQP4 KI mice exhibited dry skin, excessive epidermal proliferation, and increased inflammatory response. Local treatment with urea (10%) could alleviate these symptoms. These experimental results confirmed the important role of AQP3 in the pathogenesis of psoriasis and the potential role of urea in the treatment of psoriasis. Our study suggests the diverse physiological functions of AQP3 in different tissues. This research was supported by Beijing Natural Science Foundation (7232249). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Renal Artery Coil Embolization as an Endovascular Approach for Establishing a Rabbit Model of Chronic Kidney Disease

PurposeTo investigate the safety and feasibility of renal artery coil embolization for establishing chronic kidney disease (CKD) in rabbits. Materials and MethodsTen male adult New Zealand rabbits underwent renal artery coil embolization. Initially, the main renal artery on 1 side was completely embolized, followed by embolization of approximately two-thirds of the primary branches of the contralateral renal artery 1 week later. Four rabbits were randomly chosen for sacrifice at 4 weeks after embolization, whereas the remaining 6 were sacrificed at 8 weeks after embolization. The assessment encompassed the animals’ general condition, angiography, biochemical parameters, inflammatory markers, and histopathological examination of the kidneys and hearts. ResultsFour weeks after embolization, serum creatinine level showed a substantial increase (2.4 mg/dL [SD ± 0.6]; P = .009 vs baseline), with a subsequent 4.12-fold elevation at 8 weeks after embolization (4.9 mg/dL [SD ± 1.4]; P < .001 vs baseline). Additionally, considerable increases in serum blood urea nitrogen, calcium, and potassium ions were observed at 8 weeks after embolization (58.3 mg/dL [SD ± 19.0]; P < .001 vs baseline; 23.1 mg/dL [SD ± 4.4]; P < .001 vs baseline; and 6.3 mEq/L [SD ± 0.7]; P < .001 vs baseline, respectively). The completely embolized kidney exhibited notable atrophy, severe fibrosis, and cortical calcification, whereas the contralateral partially embolized kidney displayed compensatory hypertrophy, along with glomerulosclerosis, tubular dilation, tubular casts, and interstitial fibrosis. ConclusionsRenal artery coil embolization proved to be effective and safe for establishing a CKD model in rabbits.

Functional metabolomics reveals arsenic-induced inhibition of linoleic acid metabolism in mice kidney in drinking water

Arsenic (As) is a heavy metal known for its detrimental effects on the kidneys, but the precise mechanisms underlying its toxicity remain unclear. In this study, we employed an integrated approach combining traditional toxicology methods with functional metabolomics to explore the nephrotoxicity induced by As in mice. Our findings demonstrated that after 28 days of exposure to sodium arsenite, blood urea nitrogen, serum creatinine levels were significantly increased, and pathological examination of the kidneys revealed dilation of renal tubules and glomerular injury. Additionally, uric acid, total cholesterol, and low-density lipoprotein cholesterol levels were significant increased while triglyceride level was decreased, resulting in renal insufficiency and lipid disorders. Subsequently, the kidney metabolomics analysis revealed that As exposure disrupted 24 differential metabolites, including 14 up-regulated and 10 down-regulated differential metabolites. Ten metabolic pathways including linoleic acid and glycerophospholipid metabolism were significantly enriched. Then, 80 metabolic targets and 168 predicted targets were identified using metabolite network pharmacology analysis. Of particular importance, potential toxicity targets, such as glycine amidinotransferase, mitochondrial (GATM), and nitric oxide synthase, and endothelial (NOS3), were prioritized through the “metabolite-target-pathway” network. Receiver operating characteristics curve and molecular docking analyses suggested that 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, linoleic acid, and L-hydroxyarginine might be functional metabolites associated with GATM and NOS3. Moreover, targeted verification result showed that the level of linoleic acid in As group was 0.4951 μg/mL, which was significantly decreased compared with the control group. And in vivo and in vitro protein expression experiments confirmed that As exposure inhibited the expression of GATM and NOS3. In conclusion, these results suggest that As-induced renal injury may be associated with the inhibition of linoleic acid metabolism through the down-regulation of GATM and NOS3, resulting in decreased levels of linoleic acid, 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, and L-hydroxyarginine metabolites.

Protecting against ferroptosis in hyperuricemic nephropathy: The potential of ferrostatin-1 and its inhibitory effect on URAT1

Hyperuricemic nephropathy (HN) is characterized by renal fibrosis and tubular necrosis caused by elevated uric acid levels. Ferroptosis, an iron-dependent type of cell death, has been implicated in the pathogenesis of kidney diseases. The objective of this study was to explore the role of ferroptosis in HN and the impact of a ferroptosis inhibitor, ferrostatin-1 (Fer-1). The study combined adenine and potassium oxonate administration to establish a HN model in mice and treated HK-2 cells with uric acid to simulate HN conditions. The effects of Fer-1 on the renal function, fibrosis, and ferroptosis-associated molecules were investigated in HN mice and HK-2 cells treated with uric acid. The HN mice presented with renal dysfunction characterized by elevated tissue iron levels and diminished antioxidant capacity. There was a significant decrease in the mRNA and protein expression levels of SLC7A11, GPX4, FTL-1 and FTH-1 in HN mice. Conversely, treatment with Fer-1 reduced serum uric acid, serum creatinine, and blood urea nitrogen, while increasing uric acid levels in urine. Fer-1 administration also ameliorated renal tubule dilatation and reduced renal collagen deposition. Additionally, Fer-1 also upregulated the expression levels of SLC7A11, GPX4, FTL-1, and FTH-1, decreased malondialdehyde and iron levels, and enhanced glutathione in vivo and in vitro. Furthermore, we first found that Fer-1 exhibited a dose-dependent inhibition of URAT1, with the IC50 value of 7.37 ± 0.66 μM. Collectively, the current study demonstrated that Fer-1 effectively mitigated HN by suppressing ferroptosis, highlighting the potential of targeting ferroptosis as a therapeutic strategy for HN.

Abstract 6622: Identification of early oncogenic lesions following concomitant Vhl and Pbrm1 loss in the murine kidney

Abstract Characterizing the early events preceding tumorigenesis is a major challenge in understanding cancer. To address this, we are investigating the paradigm of clear cell renal cell carcinoma (ccRCC) that is driven by the biallelic loss of the von Hippel Lindau (VHL) tumor suppressor gene. Though VHL loss is required, additional mutations have been found in the evolution of the cancer, most commonly in Polybromo-1 (PBRM1), a subunit of the PBAF SWI/SNF chromatin remodeling complex. Concomitant Vhl and Pbrm1 deletion, but not Vhl deletion alone, in the renal tubular epithelium (RTE) has been reported to be sufficient to drive the formation of renal tumors in mice. However, the early in vivo consequences of Vhl loss, and the exact requirement for Pbrm1 loss to tumorigenesis remain poorly studied. We have previously reported the development of a novel lineage-tracing model of Vhl deletion that directly couples loss of a conditional Vhl allele to the expression of a tdTomato reporter and allows accurate identification and retrieval of marked Vhl-null cells. In the work reported here, we have combined this system with conditional Pbrm1 deletion using an RTE-restricted Pax8-CreERT2 to precisely identify and assay Vhl/Pbrm1-null cells. We describe the histological abnormalities specifically comprising Vhl/Pbrm1-null cells observed at early (1-3 weeks), intermediate (10 months), and late (17 months) intervals post recombination. We found that Vhl/Pbrm1-null cells formed extensive ‘tumorlets’, disorganized, multilayered tubules, and cystic dilated tubules specifically in the renal cortex at 17 months post recombination. Immunohistochemistry confirmed that all epithelial cells in the lesions were Vhl/Pbrm1 null and expressed HIF1 and HIF2. These lesions contained cycling cells as identified by dual tdTomato/Ki67 staining, foci of immune cells and were strikingly surrounded by cells expressing high levels of p-ERK. We then traced these lesions to earlier timepoints, and observed Vhl/Pbrm1-null lesions resembling ‘tumorlet’ precursors and disorganized tubules at 10 months post recombination specifically in the renal cortex. Interestingly, these precursors were encompassed by macrophages and could be discerned in situ by a ring of p-ERK-expressing cells surrounding these lesions. No similar lesions were detected at 3 weeks after recombination. Interestingly, the presence of cortical lesions was associated with a region-specific expansion of the total Vhl/Pbrm1-null population over time. Our data suggest that morphological abnormalities arise after a general proliferation of Vhl/Pbrm1-null cells in the renal cortex and from a subset of cells expressing specific markers. We are now comparing the differential gene expression patterns of Vhl-null cells and Vhl/Pbrm1-null normal and transformed cells at single cell resolution to expand on these observations. Citation Format: Joanna Lima, Samvid Kurlekar, Norma Masson, Ayslan B. Barros, Maria Fernanda Soares, Christopher W. Pugh, Julie Adam, Peter J. Ratcliffe. Identification of early oncogenic lesions following concomitant Vhl and Pbrm1 loss in the murine kidney [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6622.

Optimal intestinal graft selection for reconstruction of extended ureteral stricture: an animal model study

Introduction. The prevalence of patients with extended ureteral strictures has been steadily increasing over the past decades. When it is not possible to perform reconstruction with the tissues of the urinary system, the best solution is intestinal replacement plasty. However, despite the great world experience, the search for the optimal method of intestinal reconstruction does not stop, which determines the relevance of conducting an experimental prospective study.Objective. To evaluate morphological changes in renal parenchyma after ureteral replacement reconstruction by segments of small and large intestine.Materials &amp; methods. Fifteen white giant rabbits (6-months-old, weighing 5 kg) were divided into three groups. Group A (n = 5) underwent small intestine [ilealplasty] replacement plasty. Group B (n = 5) double-flap ileoplasty using the Yang-Monti technique. Group C (n = 5) – large intestine [coloplasy] ureteral reconstruction. Before the operation and before withdrawal from the experiment, the level of creatinine and electrolytes was assessed, kidney ultrasound was performed on days 2, 5, 10. Excretory urography was performed to assess the patency of the anastomoses. Animals were withdrawn from the experiment from day 10 to 30. The material used for morphological study included kidneys from the operated and intact sides, proximal and distal anastomoses.Results. No increase in creatinine level, metabolic disorders were detected in animals. According to ultrasound data, hydronephrosis developed in all animals on day 2 and remained unchanged during the entire follow-up. Group A: no complications were detected. Histologically, the renal parenchyma showed moderate signs of chronic inflammation, single foci of lymphoid infiltration, but there were no irreversible processes in the form of necrosis and sclerosis. Group B: complications — stricture in the anastomosis area of the detubularised fragments and necrosis of the small intestine due to compression of the mesentery by the graft vascular stem. Histologically there were marked dilatation of the tubules at all levels, enlargement of the Bowman-Shumlansky capsule, as well as signs of moderate inflammatory process, there were hydropic and hyaline-droplet dystrophy, tubular necrosis foci. Group C: complications — accumulation of a significant amount of grit, mucus, and fibrin in the colocystoanastomosis area. Histologically, the renal parenchyma showed a marked inflammatory process, in particular, purulent inflammation with demarcation zones, infiltration with polymorphonuclear leukocytes and bacterial cells, foci of necrosis and sclerosis of both stroma and tubules, dilatation of tubules and Bowman-Schumlansky capsules.Conclusion. The use of an unchanged ileal-graft reconstruction of an extended ureteral defect showed acceptable histological results in an animal model, which confirms the feasibility of its use in clinical practice. The absence of foci of necrosis and fibrosis in the renal parenchyma indicates the preserved functional potential, which suggests the stabilization of renal function in the long term.

Unveiling the Impact of Nandrolone Decanoate on Kidney and Heart of Rattus Norvegicus

Background: The use of anabolic androgenic steroids (AAS) like Nandrolone Decanoate (ND) for enhancing physical performance and muscle growth is prevalent among athletes and non-athletes. However, the adverse effects of AAS on organ systems, particularly the kidney and heart, have been a growing concern within the medical and scientific community. Previous studies have highlighted the potential nephrotoxic and cardiotoxic effects of these substances, necessitating further research to elucidate the extent of organ damage. Objective: This study aims to investigate the histopathological effects of ND on the kidney and heart tissues of Rattus norvegicus and to draw comparisons with control groups to assess the severity of organ damage. Methods: A total of 15 Rattus norvegicus were divided into three groups: a control group, an olive oil group (positive control), and a steroid group (ND treated). The animals were housed under controlled conditions with a 12-hour light/dark cycle at 23±2°C. The steroid and olive oil groups received 50mg/ml intramuscular injections of ND and olive oil, respectively, twice weekly for six weeks. Following treatment, the animals were euthanized, and their kidney and heart tissues were extracted for histological examination. Tissues were fixed in 10% formalin, processed, and stained with Hematoxylin and Eosin (H&amp;E) for microscopic evaluation. Results: Histological analysis revealed significant alterations in the ND-treated group compared to controls. Kidney tissues from the ND group exhibited tubular dilation, epithelial degeneration, and necrosis with a noticeable increase in Bowman's space and vascular congestion. Quantitatively, tubular atrophy and degeneration were observed in 80% of the ND-treated animals, compared to none in the control and olive oil groups. Heart tissues in the ND group showed evidence of myocardial fibrosis and necrosis, with myocardial fibrosis observed in 70% of the steroid-treated animals, significantly higher than the control groups. Conclusion: The administration of Nandrolone Decanoate in Rattus norvegicus significantly impacts kidney and heart histology, underscoring the potential health risks associated with AAS use. These findings contribute to the growing body of evidence on the nephrotoxic and cardiotoxic effects of steroids, emphasizing the need for caution and further research in human healthcare to develop safer therapeutic alternatives.

Modulation of Stem Cell Factor by Forskolin Inhibits the Progression of Tubule Interstitial Fibrosis

Purpose Forskolin is primarily found in the roots of the Coleus forskohlii plant, historically employed in Southeast Asian and Indian Ayurvedic medicine. Mast cells play a crucial role in fibrosis progression, yet their activation and inhibition in animal models are understudied; thus, we explored forskolin’s impact on kidney fibrosis. Materials and Methods Forskolin was evaluated in a mouse model for stem cell factor-induced histamine release, and plasma histamine levels were measured using the enzyme-linked immunosorbent assay. Kidney fibrosis was developed by unilateral ureteral obstruction (UUO). Renal function was assessed by spectrophotometric measurements of serum blood urea nitrogen (BUN) and creatinine. The gene expression of collagen, transforming growth factor-beta (TGF-β), α-smooth muscle actin (α-SMA), interleukin-1 beta (IL-1β), and mast cell protease-5 (MCPT-5) in the kidney was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Histopathological changes in the renal tissues were examined by hematoxylin and eosin (H&amp;E) and Masson’s trichome stain. Results Our results showed that 3 mg/kg forskolin inhibited SCF-induced plasma histamine release in a mouse model. In the 7-day UUO model, forskolin significantly showed inhibition of serum creatinine and blood urea nitrogen compared with the disease group. Forskolin significantly inhibited elevated expression of collagen, TGF-β, α-SMA, IL-1β, and MCPT-5 in the kidneys. Histopathological observation of H&amp;E and Masson trichome-stained kidney forskolin demonstrated a reduction in inflammatory cells, pelvic and tubular dilation, and fibrosis. Conclusion Forskolin showed an anti-fibrotic effect in UUO-induced renal fibrotic mice. Most significantly, forskolin administration showed a decrease in the expression of the mast cell protease MCPT5 in the kidneys. These results imply that forskolin, through modifying SCF activity, may be a viable potential treatment for the attenuation of tubule-interstitial fibrosis.

Pathogenesis and management of renal fibrosis induced by unilateral ureteral obstruction.

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.

Evaluation of the healing and protective properties of adipose-derived mesenchymal stem cells from cisplatin-induced liver and kidney damage.

The occurrence of nephrotoxicity and hepatotoxicity as a result of cisplatin administration is a major concern in clinical practice. This study examined the potential protective effects of administering mesenchymal stem cells (MSCs) on the renal and hepatic damage caused by cisplatin. Moreover, the study investigated the potential protective effects of administering Adipose-Derived Mesenchymal Stem Cells (ADMSC) to counteract the harmful effects of cisplatin-induced kidney and liver damage. Male Sprague-Dawley rats were divided into three groups: normal control, cisplatin + saline, and cisplatin + ADMSC. Cisplatin was administered to induce toxicity, and ADMSC was administered intravenously as a potential therapeutic intervention. Biochemical parameters and histopathological changes were assessed in the kidney and liver tissues. Statistical analyses were performed using a one-way ANOVA. Cisplatin increased malondialdehyde (MDA), tumor necrosis factor alfa (TNF-alfa), IL-6, alanine transaminase (ALT), creatinine, Galectin-3, Tissue growth factor beta 1 (TGF-beta 1), compared to the normal control group. Cisplatin-MSC reduced these levels. Histopathology showed that cisplatin caused kidney tubular epithelial necrosis, luminal necrotic debris, tubular dilatation, interstitial inflammation, liver sinusoidal and central vein dilatation, congestion, necrosis, and cytoplasmic vacuolization. ADMSC administration significantly reduced histopathological changes. These findings highlight the potential therapeutic benefits of mesenchymal stem cell (MSC) administration in mitigating cisplatin-induced nephrotoxicity and hepatotoxicity. MSC treatment demonstrated protective effects by reducing oxidative stress, inflammatory markers, and histopathological alterations. Further investigations are warranted to elucidate the precise mechanisms underlying these protective effects and evaluate their clinical implications for managing cisplatin-induced organ damage.

The dysfunction in intestinal microorganisms and enzyme activity as significant contributors to diarrhea with kidney-yang deficiency syndrome.

To investigate the pathogenesis of diarrhea with kidney-yang deficiency syndrome by examining characteristic changes in intestinal microorganisms, enzyme activities, oxidative stress, and metabolism indices. Twenty mice were randomly and equally divided into control group (NC) and model group (NM). Mice in NM group received adenine suspension at a dosage of 50 mg/(kg⋅day) by gavage, 0.4 mL/time, once a day for 14 days, and Folium sennae decoction at a dosage of 10 g/(kg⋅day) by gavage, 0.4 mL/time, once a day for 7 days, starting on 8th day. Mice in NC group were administered an equivalent amount of sterile water by gavage once a day for 7 days, and twice a day from the 8th day. After modeling, assessments encompassed microbial culture, organ index calculation, microbial and enzyme activity detection, malondialdehyde (MDA) content determination, superoxide dismutase (SOD) activity, blood biochemical tests, and observation of kidney tissue pathological changes. The results showed that in NM group, a reduction in the number of Lactobacillus and Bifidobacteria was noted, accompanied by an increase in the number of bacteria and E. coli. Xylanase activity in the intestinal contents and mucosa, protease activity in the intestinal mucosa, and intestinal mucosa microbial activity were diminished. Conversely, the activities of amylase, sucrase, and lactase increased in intestinal mucosa. Additionally, there was an elevation in the level of MDA. Renal tubular dilatation and inflammatory cell infiltration were observed in the renal interstitium. These dysfunctions in intestinal microorganisms and enzyme activities suggest potential involvement in diarrhea with kidney-yang deficiency syndrome.

Testicular leukaemic infiltration in relapsed acute lymphoblastic leukaemia: a case report

Abstract Background Although paediatric patients with acute lymphoblastic leukaemia (ALL) have improved survival following modern chemotherapy treatment, disease relapses still occur in 20–25% of them. Our case had relapsed ALL with testicular leukaemic infiltration, which is rare, with less than 2% incidence. Case presentation We describe a case of an 11-year-old boy with a background history of ALL presenting with painless unilateral scrotal swelling. An initial ultrasound of the testes showed heterogeneity throughout with hypervascularity on colour-flow imaging on the affected testis. Some areas are hypoechoic with dilated tubules. The histopathology of the follow-up testicular biopsy revealed malignant cells and leukaemic infiltration. Patient subsequently received chemotherapy treatment at another centre. Conclusions Testicular relapse of ALL is relatively rare with the use of improved contemporary frontline treatment with better outcomes. With its non-specific symptoms, radiological imaging can significantly facilitate timely diagnosis and contribute to appropriate further management and improved prognosis.

Effects of the Surgical Ligation of the Ureter in Different Locations on the Kidney over Time in the Rat Model.

To evaluate the effects of the surgical ligation of the ureter in different locations on the kidney over time in the rat model. A total of 155 rats were enrolled and randomly divided into the case (n = 150) and control (n = 5) groups. The case group included three separate groups (fifty rats in each group) that underwent surgical ureteral ligation at the proximal, middle, and distal ureter. The laboratory tests, and tumor necrosis factor α (TNF-α), were measured in groups. The pathological evaluation for glomerular changes, tubular dilation, interstitial fibrosis, and interstitial infiltration of the inflammatory cells following the obstruction was performed (severity of tubular atrophy categorized too mild (+), moderate (++), and severe (+++)). To compare the continuous variables between the groups and between the measurement times, the analysis of variance (ANOVA) was used. Our results revealed that the creatinine four weeks after the obstruction was significantly higher in the proximal group obstruction (p value: 0.046). The three groups had no significant differences regarding urine creatinine, serum sodium, and serum TNF (p value: 0.261). Obstruction did not change the glomerular morphology in three intervention groups after six weeks. The commencing of severe tubular atrophy in proximal, middle, and distal ureteral obstruction was at weeks three, four, and six, respectively. The location of ureteral obstruction is also crucial in deciding to intervene to relieve the complete ureteral obstruction. Severe tubular damage occurs in weeks three, four, and six in proximal, middle, and distal ureteral obstruction, respectively.