Search Results (51)

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are among the most common congenital malformations and the leading cause of chronic kidney disease in children. They arise when key steps in kidney development are disrupted, including ureteric bud induction, branching morphogenesis and nephron progenitor differentiation. These processes depend on coordinated transcriptional programs, signaling pathways, ciliary function and proper extracellular matrix (ECM) organization. Advances in whole exome and whole genome sequencing, as well as copy number variation analysis, have expanded the spectrum of known monogenic causes. Pathogenic variants have now been identified in major transcriptional regulators and multiple ciliopathy-related genes. Evidence also points to defects in central signaling pathways and changes in ECM composition as contributors to CAKUT pathogenesis. Clinical presentations vary widely, shaped by modifying effects of genetic background, epigenetic regulation and environmental influences such as maternal diabetes and fetal hypoxia. Emerging tools, including human kidney organoids, gene-editing approaches and single-cell or spatial transcriptomics, allow detailed exploration of developmental mechanisms and validation of candidate pathways. Overall, CAKUT reflects a multifactorial condition shaped by interacting genetic, epigenetic and environmental determinants. Integrating genomic data with experimental models is essential for improving diagnosis, deepening biological insight and supporting the development of targeted therapeutic strategies. Full article

Background: The 17q12 recurrent deletion syndrome is a genomic disorder encompassing a 1.4 to 1.5 Mb region that includes the HNF1B gene, and it manifests with remarkable phenotypic variability. Renal anomalies, endocrine and metabolic disturbances, and neurodevelopmental or psychiatric disorders are recurrent features, although penetrance and severity differ widely between patients. Methods: We reviewed the literature on the molecular basis, clinical presentation, diagnostic approaches, and management of 17q12 deletion syndrome, and we illustrate the variability of this condition through two contrasting paediatric cases. Results: The cases concern three siblings harbouring the same familial deletion, who nevertheless exhibited striking intrafamilial variability, ranging from renal and neurodevelopmental features to multisystemic involvement. These cases exemplify both extremes of the syndrome and highlight the challenges of clinical prognostication. Conclusions: The review and cases emphasise the importance of early genetic testing in paediatric renal anomalies, the necessity of multidisciplinary surveillance even in asymptomatic individuals, and the relevance of 17q12 deletion as a model of variable expressivity in genomic medicine. Full article

The occurrence of congenital anomalies of the kidney and urinary tract (CAKUT) is influenced by intrauterine environmental factors, and maternal exposure to endocrine-disrupting chemicals (EDCs) during pregnancy may affect the kidney development of offspring. 2,4-Di-tert-butylphenol (2,4-DTBP) is a high-production volume chemical classified as an EDC, which has been detected in humans and has been found to increase mortality and malformation rates in zebrafish embryos. Its effects on mammalian development are still unknown. In this study, a maternal mouse model exposed to 2,4-DTBP throughout pregnancy was established by gavage. The overall conditions of the maternal mice and their offspring were observed, and the concentrations of 2,4-DTBP in maternal serum and offspring tissues were measured using liquid chromatography–tandem mass spectrometry. Exposure to 2,4-DTBP of 75 µg/g·day during pregnancy markedly reduced the early pregnancy rate in mice to 41.75% (95% CI: 33.53–49.97%; n = 139), compared to 82.29% (95% CI: 74.18–90.39%; n = 85) in the controls (p < 0.0001), with a relative risk (RR) of 0.51 (95% CI: 0.41–0.63). 2,4-DTBP could accumulate in maternal mice and be transferred to embryos and internal organs of the offspring, and is associated with the elevated risk of CAKUT in the offspring, primarily manifesting as hydronephrosis/ureteral dilation. The CAKUT rate of DTBP-75 group is 33.59% (95% CI: 17.62–49.56%; N = 9, n = 56), compared to 11.85% (95% CI: 2.43–21.28%; N = 9, n = 67) in the controls (p = 0.02), RR = 2.53 (95% CI: 1.18–5.42). These findings enhance the understanding of the health risks posed by 2,4-DTBP and provide a theoretical basis for environmental monitoring in public health. Full article

Background: Genetic variants in Pre-B cell Leukemia Factor 1 (PBX1) transcription factor (TF) have been associated with Congenital Anomalies of the Kidney and Urinary Tract (CAKUT). This study aims to functionally characterize a novel missense variant in a 4-year-old patient presenting with horseshoe kidney with preserved function, in the absence of a positive familial history. Methods: Clinical exome sequencing was performed on a 4-year-old child, followed by Sanger sequencing and family segregation studies to validate the identified variant. Functional assays to study the protein expression, molecular interactions and localization were then performed. Results: Genetic analysis identified a novel de novo variant [c.712C>T, p.(Arg238Trp), NM_002585.3], mapping in the first nuclear localization signal (NLS) of PBX1. When introduced in HEK293T cells, PBX1^c.712C>T did not affect protein expression, which was comparable to the wild-type (WT) counterpart. Similar results were obtained when modeling a missense variant [c.863G>A; p.(Arg288Gln)], located in the second NLS of the protein, previously reported in the literature but never functionally characterized. As a TF, PBX1 may work in association with MEIS and PKNOX1/2 cofactors, but none of the two variants modified the interactions with its cofactor PKNOX1. However, both variants significantly affected the nuclear localization of PBX1, increasing its retention in the cytoplasm while limiting its availability in the nucleus. Conclusions: In conclusion, we identified a novel de novo heterozygous missense variant in PBX1 that impairs nuclear localization of the protein, potentially limiting its role as a TF and possibly explaining the clinical phenotype of the patient. Full article

Kidney organoids, derived from stem cells, including pluripotent stem cells and adult progenitor cells, have been reported as three-dimensional in vitro models that reflect key aspects of kidney development, structure, and function. Advances in differentiation protocols and tissue engineering have enabled the generation of organoids that exhibit nephron-like structures, including glomerular and tubular structures. Kidney organoids have been widely applied in several directions, including disease modeling and therapeutic screening, drug nephrotoxicity evaluation, and regenerative medicine. In particular, kidney organoids offer a promising platform for studying genetic kidney diseases, such as polycystic kidney disease and congenital anomalies of the kidney and urinary tract (CAKUT), by allowing patient-specific modeling for the analysis of pathophysiology and therapeutic screening. Despite several current limitations, such as incomplete maturation, lack of full nephron segmentation, and variability between protocols and cell conditions, further technological innovations such as microfluidics and bioengineering may refine kidney organoid systems. This review highlights recent advances in kidney organoid research, outlines major applications, and discusses future directions to enhance their physiological relevance, functional maturity, and translational integration into preclinical and clinical nephrology. Full article

Background: Thrombospondin-1 (TSP-1) is a matricellular protein involved in kidney fibrosis, potentially influencing the progression of proteinuria. However, its potential as a predictive biomarker for proteinuria events in children with chronic kidney disease (CKD), particularly across different etiological subgroups, such as congenital anomalies of the kidney and urinary tract (CAKUT) and non-CAKUT, has not been fully explored. Methods: In this prospective study of 60 children with CKD, we assessed baseline plasma TSP-1 and tracked proteinuria events over one year. Participants were stratified into CAKUT and non-CAKUT groups. Results: In total, 5 of 60 participants had proteinuria events. Plasma TSP-1 was significantly lower in patients with events (21.18 vs. 36.28 μg/mL, p = 0.0364). In multivariable analysis, TSP-1 lost significance overall but remained predictive in the non-CAKUT subgroup (AUC = 0.79, p = 0.064; OR = 0.93, p = 0.028). Conclusions: Plasma TSP-1 may serve as an etiology-specific biomarker for proteinuria events in pediatric CKD, particularly among non-CAKUT patients, and warrants further investigation for personalized risk assessment. Full article

Congenital anomalies of the kidney and urinary tract (CAKUT) are the third most common congenital anomaly and a significant public health concern. It is the predominant cause of chronic renal disease in pediatric populations and the principal reason for kidney replacement therapy in individuals under 20, as well as the fourth leading cause in adults. Five candidate genes, including EDA2R, PCDH9, and TRAF7 were identified as potential contributors to CAKUT. These genes had not been previously prioritized in CAKUT research, and our prior studies have demonstrated that the proteins encoded by these candidate genes display dysregulated expression across various CAKUT subgroups. Our research examined the expression patterns of EDA2R, PCDH9, and TRAF7 in yotari (Dab1^−/−) mice at two embryonic stages (E13.5 and E15.5) and two postnatal stages (P4 and P14) to ascertain the potential correlation between Reelin–Dab1 signaling, previously linked to CAKUT phenotypes, and the aforementioned proteins through molecular and morphological analyses. All three observed proteins exhibited the highest area percentage at E13.5, with a trend of decline into postnatal stages, during which specific changes in protein expression were noted between the cortex and medulla of yotari mice compared to wild-type mice. For TRAF7, a statistically significant difference in area percentage at E13.5 was observed, indicating a link with Reelin–Dab1 signaling and a potentially critical role in the pathophysiology of CAKUT, also marked by our prior study. Full article

Congenital anomalies of the kidney and urinary tract (CAKUT) are a major cause of pediatric renal failure, but the molecular mechanisms driving these conditions are not yet fully understood. Fibroblast Growth Factor 23 (FGF23) and its co-receptor α-KLOTHO play crucial roles in regulating calcium and phosphate homeostasis in adult kidneys, but their roles in kidney development and the pathogenesis of CAKUT remain unclear. Because of that, we analyzed the spatial and temporal expression of FGF23 and α-KLOTHO in normal fetal kidney development and CAKUT using an immunofluorescence technique. Our results demonstrate a dynamic pattern of FGF23 and α-KLOTHO expression in healthy kidney development, with FGF23 levels decreasing and α-KLOTHO levels increasing with gestational age. Also, we showed that FGF23 expression was significantly reduced in horseshoe (HKs) and duplex kidneys (DKs), while α-KLOTHO expression remained unchanged across all CAKUT conditions. Based on our results, we suggest that altered FGF23 expression in CAKUT contributes to disease pathogenesis and may represent a potential therapeutic target. Full article

Mitochondrial dysfunction is a pivotal driver in the pathogenesis of acute kidney injury (AKI), chronic kidney disease (CKD), and congenital anomalies of the kidney and urinary tract (CAKUT). The kidneys, second only to the heart in mitochondrial density, rely on oxidative phosphorylation to meet the high ATP demands of solute reabsorption and filtration. Disrupted mitochondrial dynamics, such as excessive fission mediated by Drp1, exacerbate tubular apoptosis and inflammation in AKI models like ischemia–reperfusion injury. In CKD, persistent mitochondrial dysfunction drives oxidative stress, fibrosis, and metabolic reprogramming, with epigenetic mechanisms (DNA methylation, histone modifications, non-coding RNAs) regulating genes critical for mitochondrial homeostasis, such as PMPCB and TFAM. Epigenetic dysregulation also impacts mitochondrial–ER crosstalk, influencing calcium signaling and autophagy in renal pathology. Mitophagy, the selective clearance of damaged mitochondria, plays a dual role in kidney disease. While PINK1/Parkin-mediated mitophagy protects against cisplatin-induced AKI by preventing mitochondrial fragmentation and apoptosis, its dysregulation contributes to fibrosis and CKD progression. For instance, macrophage-specific loss of mitophagy regulators like MFN2 amplifies ROS production and fibrotic responses. Conversely, BNIP3/NIX-dependent mitophagy attenuates contrast-induced AKI by suppressing NLRP3 inflammasome activation. In diabetic nephropathy, impaired mitophagy correlates with declining eGFR and interstitial fibrosis, highlighting its diagnostic and therapeutic potential. Emerging therapeutic strategies target mitochondrial dysfunction through antioxidants (e.g., MitoQ, SS-31), mitophagy inducers (e.g., COPT nanoparticles), and mitochondrial transplantation, which mitigates AKI by restoring bioenergetics and modulating inflammatory pathways. Nanotechnology-enhanced drug delivery systems, such as curcumin-loaded nanoparticles, improve renal targeting and reduce oxidative stress. Epigenetic interventions, including PPAR-α agonists and KLF4 modulators, show promise in reversing metabolic reprogramming and fibrosis. These advances underscore mitochondria as central hubs in renal pathophysiology. Tailored interventions—ranging from Drp1 inhibition to mitochondrial transplantation—hold transformative potential to mitigate kidney injury and improve clinical outcomes. Additionally, dietary interventions and novel regulators such as adenogens are emerging as promising strategies to modulate mitochondrial function and attenuate kidney disease progression. Future research should address the gaps in understanding the role of mitophagy in CAKUT and optimize targeted delivery systems for precision therapies. Full article

Pediatric chronic kidney disease (CKD) is a growing concern that often originates early in life, yet significant challenges remain in translating clinical guidelines into real-world practice. World Kidney Day 2025 highlights the importance of early detection, but the three levels of preventive strategies commonly recommended for adults may not be directly applicable to children. Unlike adult CKD, primary prevention in pediatrics should focus on prenatal, neonatal, and early-life factors such as congenital anomalies of the kidney and urinary tract (CAKUT), preterm birth, maternal health, and environmental exposures. Secondary prevention, involving early detection through screening, is crucial, yet the effectiveness of mass urinary screening in children remains a subject of global debate. Several key challenges persist, including the accurate estimation of glomerular filtration rate (eGFR), consistent definition and diagnosis of pediatric hypertension, identification of reliable biomarkers, and targeted screening in specific pediatric populations. Although clear guidelines exist to manage CKD progression and enhance quality of life, a critical gap remains between what is known and what is practiced. Closing this gap requires robust evidence to inform best practices, improve health-related quality of life, and advance pediatric kidney replacement therapies. To protect and improve kidney health for every child worldwide, these challenges must be acknowledged, and sustainable, evidence-based solutions must be developed and implemented without further delay. Full article

Background/Objectives: The human kallikrein-related peptidase 6 (KLK6), a serine protease with trypsin-like properties, belongs to the 15-member kallikrein (KLK) gene family and is predominantly recognized for its role in oncogenesis, neurodegenerative disorders, and skin conditions. Aquaporins (AQPs) are integral membrane proteins that facilitate water transport across cell membranes. AQP1 is constitutively active in the kidneys and plays a crucial role in reabsorbing filtered water, while AQP2 is regulated by vasopressin and is essential for maintaining body fluid homeostasis. The primary objective of the present study is to investigate the spatio-temporal expression patterns of KLK6, AQP1, and AQP2 throughout normal human nephrogenesis and congenital kidney and urinary tract (CAKUT) abnormalities: duplex kidneys, horseshoe kidneys, and dysplastic kidneys. Methods: An immunofluorescence analysis of KLK6, AQP1, and AQP2 was performed on 37 paraffin-embedded fetal kidney samples. The area percentage of KLK6 in the kidney cortex was calculated in normal developing samples during developmental phases 2, 3, and 4 and compared with CAKUT samples. Results: KLK6 exhibits distinct spatiotemporal expression patterns during human kidney development, with consistent localization in proximal tubules. Its subcellular positioning shifts from the basolateral cytoplasm in early phases to the apical cytoplasm in later stages, which may be strategically positioned to act on its substrate in either the peritubular space or the tubular fluid. KLK6 expression followed a quadratic trajectory, peaking at Ph4. This marked increase in the final developmental phase aligns with its strong expression in mature kidneys, suggesting a potential role in proximal tubule differentiation and functional maturation through facilitating extracellular matrix remodeling and activating proteinase-activated receptors, modulating the signaling pathways that are essential for tubular development. In duplex kidneys, structural abnormalities such as ureteral obstruction and hydronephrosis may upregulate KLK6 as part of a reparative response, while its downregulation could impair epithelial remodeling and cytoskeletal integrity, exacerbating dysplastic phenotypes. Conclusions: These findings highlight the potential of KLK6 involvement in normal kidney development and the pathology of CAKUT. Full article

Congenital anomalies of the kidney and urinary tract (CAKUT) are common developmental malformations and a leading cause of pediatric renal dysfunction. Severe hydronephrosis, especially when accompanied by ureteral duplication, ureterocele, or neurogenic bladder, poses significant diagnostic and therapeutic challenges. This case report presents a 7-year-old male with prenatally diagnosed bilateral grade IV/V hydronephrosis (according to the radiology hydronephrosis grading system), complicated by the right pyeloureteral duplication, the left ureterocele, and the neurogenic bladder. The patient’s clinical course was marked by recurrent urinary tract infections (UTIs), progressive renal dysfunction, and multiple surgical interventions. Initial decompression via bilateral ureterostomy and stenting led to significant improvements in renal function. However, the patient experienced recurrent febrile UTIs caused by multidrug-resistant pathogens, necessitating repeated hospitalizations and intravenous antibiotic therapy. Serial imaging studies documented persistent hydronephrosis, a neurogenic bladder, and vesicoureteral reflux. Subsequent surgical interventions included bilateral ureteral reimplantation, excision of the left ureterocele, and removal of a fibroepithelial polyp from the bladder wall. Despite these interventions, residual left hydronephrosis and right kidney hypoplasia persisted, underscoring the need for long-term surveillance. This case highlights the diagnostic and therapeutic challenges of managing CAKUT and emphasizes the importance of a multidisciplinary approach integrating imaging, functional assessment, and surgical planning. Early diagnosis and timely intervention can stabilize renal function, but ongoing monitoring and individualized treatment remain crucial for optimizing long-term outcomes in children with complex CAKUT. Full article

Congenital anomalies of the kidney and urinary tract (CAKUT) are a common cause of chronic kidney disease in children. Most patients will reach end-stage renal function and dialysis or transplantation in childhood or early adulthood. Patients with CAKUT deserve a careful evaluation before a kidney transplant; detailed imaging and functional studies are necessary, particularly in the presence of lower urinary tract abnormalities, and surgical procedures are advisable in selected cases. A higher incidence of complications has been reported after a kidney transplant in CAKUT, mainly urinary tract infections. However, in the long term, the prognosis seems to be comparable to other kidney diseases. A large number of reports are available in the literature on medical and surgical management of patients with CAKUT before, during, and after a kidney transplant; almost all recommendations of surgical procedures before a kidney transplantation are based on retrospective not controlled studies or personal opinions; prospective controlled studies are needed. In this narrative, nonsystematic review, we report the results of recently published selected studies and underline questions that should be addressed in future guidelines. Full article

Background/Objectives: The prevalence of chronic kidney disease (CKD) is increasing worldwide, and this tendency is also visible in pediatric patients. The major clinical challenge is to achieve a diagnosis as early as possible, despite an overt clinical course, especially in the early stages of the disease. Unfavorable external conditions may disturb the proper treatment of chronically ill patients and delay the time of diagnosis. The recent COVID-19 pandemia might have altered the usual diagnostic pathways of different comorbidities, and CKD was probably one of them. However, there are no data on newly diagnosed CKD in children during the time of the pandemia, so our aim was to approach this problem. Methods: We analyzed medical records of 154 children with CKD who were hospitalized in the Department of Pediatric Nephrology in prepandemic (years 2015–2019) vs. pandemic and postpandemic (2020–2024) conditions, analyzing the eGFR value and stage of CKD at diagnosis, the underlying diseases leading to CKD, and sex-related differences. Results: The number of patients who were diagnosed with CKD in both time periods was comparable. Children hospitalized in the years 2020–2024 presented more often with advanced stages of CKD. The trend towards an increasing share of glomerulopathies, acute kidney injury, and unknown causes of CKD was noticeable under pandemic conditions. Conclusions: The COVID-19 pandemic could, probably owing to reduced access to primary healthcare and disrupted routine check-ups, delay the process of diagnosing CKD in children. Full article