Search Results (151)

Nephronophthisis (NPH) is the leading genetic cause of end-stage renal disease in children and young adults, but no effective disease-modifying therapies are currently available. Here, we identify glucagon-like peptide-1 (GLP-1) signaling as a novel therapeutic target for NPH through a systematic drug repurposing screen in zebrafish. By simultaneously depleting nphp1 and nphp4, we developed a robust zebrafish model that reproduces key features of human NPH, including glomerular cyst formation. Our screen revealed that dipeptidyl peptidase-4 (DPP4) inhibitors (Omarigliptin and Linagliptin) and GLP-1 receptor agonists (Semaglutide) significantly reduce cystogenesis in a dose-dependent manner. Genetic analysis demonstrated that GLP-1 receptor signaling is important for maintaining pronephros integrity, with gcgra and gcgrb (GLP-1 receptor genes) playing a particularly important role. Transcriptomic profiling identified adenosine receptor A2ab (adora2ab) as a key downstream effector of GLP-1 signaling, which regulates ciliary morphology and prevents cyst formation. Notably, nphp1/nphp4 double mutant zebrafish exhibited the upregulation of gcgra as a compensatory mechanism, which might explain their resistance to cystogenesis. This compensation was disrupted by the targeted depletion of GLP-1 receptors or the inhibition of adenylate cyclase, resulting in enhanced cyst formation, specifically in the mutant background. Our findings establish a signaling cascade from GLP-1 receptors to adora2ab in terms of regulating ciliary organization and preventing cystogenesis, offering new therapeutic opportunities for NPH through the repurposing of FDA-approved medications with established safety profiles. Full article

Polycystic liver disease (PLD) is a rare genetic disorder characterized by the development of >10 fluid-filled cysts in the liver. While PLD can occur in isolation, it is most commonly associated with autosomal dominant polycystic kidney disease, adding complexity to its management. PLD is often asymptomatic but can lead to hepatomegaly, causing symptoms such as abdominal distension, pain and discomfort, early satiety, gastroesophageal reflux, and malnutrition, ultimately affecting patients’ quality of life. Current treatment strategies, including pharmacological and interventional approaches, focus on reducing liver volume and alleviating symptoms. However, management remains largely symptomatic, as no definitive therapies exist to halt cyst progression. Liver transplantation is the only curative option for patients with severe, progressive disease and refractory complications. The EASL guidelines recognize that PLD-related symptoms, primarily due to hepatomegaly, can contribute to involuntary weight loss and recommend assessing symptomatic patients for malnutrition and sarcopenia. Although evidence suggests that patients with PLD may be at risk of malnutrition, original data on the quality and extent of nutritional alterations remain scarce. The potential influence of nutrition on disease progression, symptom burden, and overall well-being is also largely unexplored. Given these knowledge gaps, addressing nutritional challenges, such as early satiety, is essential for optimizing symptom management and maintaining overall nutritional status. This review outlines a possible pathophysiology of malnutrition, specific dietary considerations and recommendations, and weight management in patients with PLD. Additionally, dietary complexities in patients with concurrent renal involvement are discussed, offering a practical framework for clinicians and dietitians in managing this challenging condition. Full article

A 10-year-old intact female Bichon Frise presented with multiple firm skin nodules on all four limbs. The nodules progressively increased in number and size over seven months. Diagnostic tests included cytology of fine-needle aspirates, histopathology of skin biopsies, radiography, and abdominal ultrasonography. Cytology revealed spindle-shaped mesenchymal cells and extracellular matrix components, and histopathology confirmed ND characterized by mature collagen deposition without evidence of malignancy. Ultrasonography detected multiple kidney cysts bilaterally, although their exact nature (benign or malignant) could not be confirmed histologically. Genetic analysis was performed, revealing no mutation in the traditionally implicated FLCN gene but multiple nonsynonymous mutations in the BRCA2 gene. This case suggests a potential association between BRCA2 gene mutations and the development of ND with renal cystic lesions, broadening the known genetic causes beyond the commonly reported FLCN mutation. Regular genetic screening and close monitoring of dermatological and renal conditions in atypical breeds are recommended. To the best of current knowledge, this is the first case report demonstrating ND and renal cysts associated with BRCA2 mutations in a Bichon Frise. Full article

Exercise training in extreme temperatures concurrent with hypohydration status may potentiate the development of acute kidney injury (AKI) in young, healthy persons. Background/Objectives: It is unknown how repeated training bouts in ambient higher temperatures and humidity may influence measures of AKI. The purpose of this study was to investigate hydration status and renal biomarkers related to AKI in NCAA Division I female soccer athletes during preseason conditioning. Methods: A convenience sample of n = 21 athletes were recruited (mean ± SEM; age: 19.3 ± 0.25 y; height: 169.6 ± 1.36 cm; mass: 68.43 ± 2.46 kg; lean body mass: 45.91 ± 1.13 kg; fat mass: 22.51 ± 1.69 kg; body fat %: 32.22 ± 1.32%). The average temperature was 27.43 ± 0.19 °C, and the humidity was 71.69 ± 1.82%. Body composition, anthropometric, workload, and 14 urine samples were collected throughout the preseason training period for urine specific gravity (USG), creatinine (uCr), cystatin C (uCyst-C), and neutrophil gelatinase-associated lipocalin (uNGAL) analyses. Results: Our investigation showed that, when compared to baseline (D0), the athletes maintained a USG-average euhydrated status (1.019 ± 0.001) and were euhydrated prior to each exhibition game (D5-Pre: p = 0.03; 1.011 ± 0.001; D10-Pre: p = 0.0009; 1.009 ± 0.001); uCr was elevated on D8 (p = 0.001; 6.29 ± 0.44 mg·dL⁻¹·LBM⁻¹) and D10-Post (p = 0.02; 6.61 ± 0.44 mg·dL⁻¹·LBM⁻¹); uCyst-C was elevated on D6 through D10 (p = 0.001; ~0.42 ± 0.01 mg·dL⁻¹); no differences were found in uNGAL concentration. The highest distance (m) displaced was found during exhibition games (D5: p = <0.0001; ~8.6 km and D10: p = <0.0001; ~9.6 km). During the preseason conditioning, the athletes maintained a euhydrated status (~1.019) via USG, an increase in uCr that averaged within a normal range (208 mg·dL⁻¹), and an increase in uCyst-C to near AKI threshold levels (0.42 mg·L⁻¹) for several practice sessions, followed by an adaptive decline. No differences were found in uNGAL, which may be explained by athlete variation, chosen time sample collection, and variation in training and hydration status. Conclusions: The athletes maintained a euhydrated status, and this may help explain why urinary markers did not change or meet the reference threshold for AKI. Full article

Autosomal dominant polycystic kidney disease (ADPKD) is a prevalent hereditary renal disorder characterized by the progressive formation of numerous fluid-filled cysts, ultimately leading to end-stage kidney disease. The results of recent studies have demonstrated that metabolic reprogramming plays a crucial role in cystogenesis and disease progression, including enhanced aerobic glycolysis, impaired fatty acid oxidation, glutamine dependence, and mitochondrial dysfunction; these metabolic alterations are regulated by signaling pathways such as mTOR, cAMP/PKA, and HIF-1α, which can modulate cell proliferation, fluid secretion, and energy metabolism. Furthermore, hypoxia and the oxidative microenvironment also promote the growth of cysts. In this review, we summarized the complex interactions between metabolic pathway alterations and key signaling cascades in ADPKD, in addition to exploring new therapeutic strategies targeting these metabolic pathways, including drug and dietary interventions. A comprehensive understanding of these mechanisms may contribute to the development of innovative treatment methods aiming to slow the disease progression of patients with ADPKD. Full article

Pathogenic variants in type IV collagen genes (COL4A3, COL4A4, COL4A5) are classically associated with Alport syndrome (AS), a hereditary nephropathy primarily affecting the glomerular basement membrane (GBM). Recent findings, however, suggest a broader phenotypic spectrum that includes renal cyst formation, raising questions about overlapping mechanisms with other cystic kidney diseases. Clinically, renal cysts have been increasingly reported in patients with autosomal dominant and X-linked forms of Alport syndrome, particularly in association with glycine missense variants. The most recent studies focusing on the cystic phenotype in Alport syndrome provide growing support for the idea that variants in type IV collagen genes are associated with an increased likelihood of developing renal cysts, likely through mechanisms involving the structural integrity of renal basement membranes. In this review, we explore evidence from murine models and human studies indicating defects in collagen IV and discuss their contribution to cystogenesis. These observations underscore the need for broader genetic screening strategies and further investigation into the molecular mechanisms underlying this emerging phenotype. Full article

The Bosniak classification categorizes renal cystic lesions based on cross-sectional imaging features from clearly benign (Bosniak type I) to malignant lesions (Bosniak type IV). A 67-year-old female patient presented to the emergency department with typical symptoms of acute cholecystitis. During a transabdominal ultrasound examination, an incidental finding was a suspicious cluster of anechoic cystic lesions with internal septa in the left kidney. Following contrast-enhanced computed tomography (CT), the lesion was categorized as a Bosniak type IV cyst. Compared to an earlier CT scan, a Bosniak type I cyst preceded the current Bosniak type IV cyst, suggesting a malignant alteration over the 7-year interval. It was surgically removed, and pathohistological analysis revealed cystic renal cell carcinoma. Although simple renal cysts rarely become malignant, scientific discussion about potential algorithms for additional surveillance is needed. Full article

Polycystic kidney disease (PKD), a ciliopathy caused primarily by mutations in the Pkd1 and Pkd2 genes, disrupts renal structure and function, leading to progressive renal failure. The primary cilium, a sensory organelle essential for cellular signaling, plays a pivotal role in maintaining renal function. Among its signaling components, G-protein-coupled receptors (GPCRs) within the cilium have gained significant attention for their localized functions and their contribution to PKD pathogenesis. Dysfunction of ciliary GPCR signaling alters key downstream pathways, including mammalian target of rapamycin (mTOR), cyclic adenosine monophosphate (cAMP), and calcium homeostasis, exacerbating cyst formation and disease progression. Additionally, interactions between ciliary GPCRs and PKD-associated proteins, such as Polycystin-1 (PC1) and Polycystin-2 (PC2), underline the complexity of PKD mechanisms. Recent advances highlight GPCRs as promising therapeutic targets for ciliopathies, including PKD. Emerging GPCR modulators and drugs in clinical trials show the potential to restore ciliary signaling and attenuate disease progression. This paper explores the physiological functions of ciliary GPCRs, their mechanistic links to PKD, and the therapeutic implications of targeting these receptors, offering insights into future research directions and therapeutic strategies for PKD. Full article

Background: This study investigated the clinical features, underlying causes, and management of patients with spontaneous perirenal hemorrhage (Wunderlich syndrome; WS). Methods: We retrospectively reviewed the records of patients hospitalized for WS at a single tertiary center between 2011 and 2024. All patients were evaluated for non-traumatic perirenal hemorrhage identified on computed tomography (CT) in the emergency department. Clinical variables, including age, underlying diseases, symptoms, hemodynamic instability, and hospitalization course, were analyzed. Laboratory test results, as well as radiological and pathological findings, were reviewed. Results: The study included 46 events from 38 patients, with a median (IQR) follow-up period of 32 (4–82) months. The most common presenting symptom was flank pain, observed in 44 cases (95.7%). Renal lesions, including visible tumors, were detected in 25 cases (54.3%), while 13 cases (28.3%) exhibited perirenal hematoma without a distinct lesion. Among seven patients with hemodynamic instability (systolic blood pressure < 90 mmHg), one underwent emergency embolization, and four required emergency surgical exploration. Surgical intervention was performed in 13 cases (28.3%), all involving nephrectomy, while radiologic embolization was attempted in seven cases (15.2%), with one patient later requiring delayed nephrectomy. The final diagnosis revealed renal cell carcinoma in eight cases (six patients), angiomyolipoma in 11 cases (six patients), renal cysts in six cases, acquired cystic kidney disease in six cases, sarcoma in three cases, perivascular epithelioid cell tumor in one case, lymphoma in one case, and chronic pyelonephritis in four cases; no specific disease was identified in six cases. During follow-up, six patients died; four of these deaths were directly related to WS or its underlying etiologies. Conclusions: WS is a potentially life-threatening condition, with benign or malignant renal masses being the most common causes. Although the advancement of interventional techniques has led to an increasing number of cases being conservatively managed, the possibility of renal malignancy should always be considered. Full article

Background and Clinical Significance: Polycystic kidney disease (PKD) is the most common inherited kidney condition, affecting approximately 500,000 individuals in the US. It causes fluid-filled cysts to develop throughout the kidneys, leading to decreased kidney function. Autosomal dominant polycystic kidney disease (ADPKD) is the more prevalent form, subdivided into the PKD1 and PKD2 variants. PKD1 variants typically result in more severe symptoms and an earlier need for dialysis compared to PKD2. A prenatal diagnosis of ADPKD is rare due to its late-onset manifestations, but early detection can be crucial for management and family counseling. Case Presentation: A 24-year-old woman, during her first pregnancy, presented for her first prenatal ultrasound at 22 + 2 weeks gestation. The ultrasound revealed an increased echogenicity of the renal parenchyma in the left kidney, with pelvic dystopia, while the right kidney appeared normal. Follow-up scans showed significant progression, with both kidneys exhibiting thinning parenchyma and cyst formation. The baby was delivered via an elective cesarean section at 38 weeks, and a postnatal ultrasound confirmed ADPKD. Genetic testing identified a heterozygous variant of the PKD1 gene, NM_001009944.3 (PKD1):c.9157G>A p.(Ala3053Thr), classified as likely pathogenic. The baby displayed electrolyte abnormalities but improved after a week of hospitalization. Conclusions: This case highlights an unusual early presentation of ADPKD in a fetus with no family history of the disease. A prenatal diagnosis through ultrasounds and genetic testing can aid in early detection and management, providing valuable information for family counseling. Regular monitoring and genetic identification are essential for managing ADPKD and improving patient outcomes. Full article

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inheritable disease of cystic degeneration in the kidney. ADPKD is a significant cause of end-stage renal disease (ESRD). Autosomal Dominant Polycystic Liver Disease (ADPLD) results in substantial PLD with minimal PKD. Currently, there are eight genes which have been associated with ADPKD (PKD1 and PKD2), ADPLD (PRKCSH, SEC63, LRP5, ALG8, and SEC61B), or both (GANAB). The severity of ADPKD can show an extremely broad range, but the evolution to ESRD is doubtless unavoidable. In some patients, carcinogenesis develops with inflammation as a potential promoting factor. In this chapter, we illustrate the severity of ADPKD and the fate to develop renal cell carcinoma (RCC). Full article

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease, affecting approximately 1 in 1000 individuals. This genetically heterogeneous condition is primarily caused by monoallelic pathogenic or likely pathogenic variants in the PKD1 and PKD2 genes, accounting for 78% and 15% of typical cases, respectively. Recently, the application of NGS methods has led to the identification of additional genes associated with ADPKD, which have been incorporated into routine diagnostic testing for detecting phenocopies of the disease. Methods: In this study, targeted NGS (tNGS) analysis of the main cystogenes associated with classic and atypical ADPKD was performed in a cohort of 218 patients clinically diagnosed with cystic nephropathies. Results: Genetic testing identified variants in 175 out of 218 cases (80.3%). Among these, 133 probands (76%) harbored likely pathogenic or pathogenic variants in one or more genes of the panel, while 42 individuals (24%) had a variant of unknown significance (VUS). Specifically, one or more class 4/5 variants in PKD1, PKD2, or both were identified in 111 (83.5%) probands. Remarkably, a pathogenic variant in the IFT140 gene was identified in 14 index cases (8% of positive individuals, 6.4% of the global cohort): 10 distinct loss-of-function (LoF) variants were identified (including four frameshift variants, four nonsense variants, and two splice site defects); one individual carried a second IFT140 missense variant classified as VUS. Furthermore, five affected family members were found to carry a P/LP LoF variant in IFT140. Conclusions: Our data support that IFT140 heterozygous IFT140 LoF variants result in an atypical, mild form of ADPKD, consisting of bilateral kidney cysts and renal functional decline at older ages. Furthermore, we describe the second pediatric patient with a mild form of ADPKD due to an IFT140 variant and discuss hyperuricemia as a previously unappreciated feature of this condition. Full article

Background/Objectives: Renal cell cancer is a rare occurrence in patients with ulcerative colitis (UC), with no clearly demonstrated association between UC and an increased risk of renal malignancies. In this article, a case report concerning this relationship is presented. Methods: Our research group presented a case of clear cell renal carcinoma in a 56-year-old male with UC who had previously undergone ileorectal anastomosis and subtotal colectomy. Results: The patient developed a complex renal cyst that progressed to malignancy within one year while on immunosuppressive therapy with infliximab and then filgotinib. Previous ultrasound examinations of the kidney highlighted only simple cysts in the contralateral kidney in previous years. The neoplasm was promptly examined using contrast-enhanced ultrasound, confirming the diagnosis of a Bosniak IV cyst, which was corroborated by a subsequent computed tomography study. Conclusions: The patient underwent a nephrectomy and is currently scheduled for therapy with vedolizumab. Given the increasing use of biologics and small molecules in UC management, periodic ultrasound screening may be a valuable tool for the long-term monitoring of these patients. Full article

Objectives: To describe the US, CEUS, CT, and MRI features of papillary renal cell carcinoma (PRCC) and to underline the imaging characteristics that are helpful in the differential diagnosis. Methods: Patients with histologically proven papillary renal cell carcinoma who underwent at least two imaging examinations (US, CEUS, CT, and MRI) were included in the study. Tumor size, homogeneity, morphology, perilesional stranding, contrast enhancement locoregional extension were assessed. A comparison and the characteristics of the imaging features for each imaging modality were analyzed. Results: A total of 27 patients with an histologically confirmed diagnosis of PRCC were included in the study. US was highly accurate in distinguishing solid masses from cystic masses, supporting the differential diagnosis of PRCC, as well as in patients with a poor representation of the solid component. CEUS significantly increased diagnostic accuracy in delineating the solid intralesional component. Furthermore, when using CEUS, in the arterial phase, PRCC exhibited hypo-enhancement, and in the late phase it showed an inhomogeneous and delayed wash-out compared with the surrounding renal parenchyma. At MRI, PRCC showed a marked restiction of DWI and was hypointense in the T2-weighted compared to the renal parenchyma. Conclusions: In our study, the characteristic hypodensity and hypoenhancement of PRCC make CT the weakest method of their recognition, while US/CEUS and MRI are necessary to reach a definitive diagnosis. Knowledge of the appearance of PRCC can support an early diagnosis and prompt management, and radiologists should be aware that PRCC, when detected using CT, may resemble spurious non-septate renal cyst. Full article

Tuberous sclerosis complex (TSC) is caused by mutations in TSC1 or TSC2 genes and affects multiple organs. TSC proteins control cell growth by regulating the activity of the mechanistic target of rapamycin complex 1. Extracellular vesicles (EVs) are membrane-bound particles produced by cells that mediate cellular communication, function, and growth. Although extensive studies regarding the genetic basis of TSC exist, the exact mechanism contributing to its pathogenesis remains unresolved. It has been proposed that EVs generated by renal cyst epithelia of mice and cells with Tsc gene mutations contain factors that alter the function and proliferation of TSC-sufficient cells. To test this, EVs from the kidneys and kidney explants of wildtype and Tsc1KO mice were isolated and characterized by Western blotting, transmission electron microscopy, dynamic light scattering, and fluorescent nanoparticle tracking. Our results show an enrichment in EV-associated markers and particle sizes of similar ranges. RNA-seq and proteomic analyses identified EV shuttle factors. EV RNA and protein shuttle factors showed significant differences. Furthermore, EVs isolated from Tsc1KO mice inhibited the proliferation of M-1 cells. Understanding the role of EVs in cell proliferation and cystogenesis in TSC may lead to the development of new approaches for the treatment of this disease. Full article