A systematic review and meta-analysis of mortality and kidney function in uranium-exposed individuals.

BACKGROUND: Humans are exposed to uranium (U) in a variety of applications. Both animal and observational human studies support an associated U nephrotoxicity. Few statistical syntheses of the human data have been performed and these analyses are limited in the types of exposures considered. OBJECTIVES: This study aims to evaluate the state of current evidence and to expand on existing meta-analyses by systematically evaluating kidney-associated causes of mortality in multiple U-exposed populations. This study also aims to evaluate the effect of U exposure on kidney function and biomarkers of kidney injury. METHODS: The published and grey literature were systematically reviewed for studies that reported Standardized Mortality Ratios (SMR) for kidney cancer, chronic nephritis/nephrosis, all-cause mortality, diabetes, all circulatory/heart disease, and/or ischemic heart disease in U-exposed humans. Studies that reported kidney biomarker measures for U-exposed versus control subjects were identified separately. RESULTS: 36 studies were included. The studies were parsed into subgroups based on setting of exposure. Analysis of kidney cancer and chronic nephritis/nephrosis mortality demonstrated an SMR of 0.93 (95CI: 0.82-1.05) and 0.82 (95CI: 0.70-0.96), respectively. The other clinical outcomes evaluated also demonstrated mortality deficits in exposed relative to unexposed individuals. Subgroup analyses demonstrated similar mortality deficits. Conversely, biomarker analyses suggested better kidney function in the controls, but none of these differences reached significance. DISCUSSION: Given that most of the included mortality studies were conducted in occupational populations, the mortality deficits observed in our analyses were likely due to the healthy-worker effect. Additionally, our analyses of kidney biomarkers were severely limited by low precision due to a low number of available studies and small study-size. Future work needs to evaluate the progression of chronic and to end-stage kidney disease in community-based populations to better assess the full impact of prolonged chronic U exposure on kidney outcomes.

Role of the Ste20-like kinase SLK in podocyte adhesion.

SLK controls the cytoskeleton, cell adhesion, and migration. Podocyte-specific deletion of SLK in mice leads to podocyte injury as mice age and exacerbates injury in experimental focal segment glomerulosclerosis (FSGS; adriamycin nephrosis). We hypothesized that adhesion proteins may be substrates of SLK. In adriamycin nephrosis, podocyte ultrastructural injury was exaggerated by SLK deletion. Analysis of a protein kinase phosphorylation site dataset showed that podocyte adhesion proteins-paxillin, vinculin, and talin-1 may be potential SLK substrates. In cultured podocytes, deletion of SLK increased adhesion to collagen. Analysis of paxillin, vinculin, and talin-1 showed that SLK deletion reduced focal adhesion complexes (FACs) containing these proteins mainly in adriamycin-induced injury; there was no change in FAC turnover (focal adhesion kinase Y397 phosphorylation). In podocytes, paxillin S250 showed basal phosphorylation that was slightly enhanced by SLK; however, SLK did not phosphorylate talin-1. In adriamycin nephrosis, SLK deletion did not alter glomerular expression/localization of talin-1 and vinculin, but increased focal adhesion kinase phosphorylation modestly. Therefore, SLK decreases podocyte adhesion, but FAC proteins in podocytes are not major substrates of SLK in health and disease.

Clinical and molecular characteristics of two Italian kindreds with hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome.

PURPOSE: Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome, also known as Barakat syndrome, is a rare autosomal dominant disease characterized by the triad of hypoparathyroidism, deafness, and renal abnormalities. The disorder is caused by the haploinsufficiency of the zinc finger transcription factor GATA3 and exhibits a great clinical variability with an age-dependent penetrance of each feature. We report two unrelated kindreds whose probands were referred to our outpatient clinic for further evaluation of hypoparathyroidism. METHODS: The proband of family 1, a 17-year-old boy, was referred for severe hypocalcemia (5.9 mg/dL) incidentally detected at routine blood tests. Abdomen ultrasound showed bilateral renal cysts. The audiometric evaluation revealed the presence of bilateral moderate hearing loss although the patient could communicate without any problem. Conversely, the proband of family 2, a 19-year-old man, had severe symptomatic hypocalcemia complicated by epileptic seizure at the age of 14 years; his past medical history was remarkable for right nephrectomy at the age of 4 months due to multicystic renal disease and bilateral hearing loss diagnosed at the age of 18 years. RESULTS: Based on clinical, biochemical, and radiologic data, HDR syndrome was suspected and genetic analysis of the GATA3 gene revealed the presence of two pathogenetic variants in exon 3, c.404dupC and c.431dupG, in the proband of family 1 and 2, respectively. CONCLUSION: HDR syndrome is a rare cause of hypoparathyroidism and must be excluded in all patients with apparently idiopathic hypoparathyroidism. A correct diagnosis is of great importance for early detection of other HDR-related features and genetic counseling.

Role of the SLC22A17/lipocalin-2 receptor in renal endocytosis of proteins/metalloproteins: a focus on iron- and cadmium-binding proteins.

The transmembrane protein SLC22A17 [or the neutrophil gelatinase-associated lipocalin/lipocalin-2 (LCN2)/24p3 receptor] is an atypical member of the SLC22 family of organic anion and cation transporters: it does not carry typical substrates of SLC22 transporters but mediates receptor-mediated endocytosis (RME) of LCN2. One important task of the kidney is the prevention of urinary loss of proteins filtered by the glomerulus by bulk reabsorption of multiple ligands via megalin:cubilin:amnionless-mediated endocytosis in the proximal tubule (PT). Accordingly, overflow, glomerular, or PT damage, as in Fanconi syndrome, results in proteinuria. Strikingly, up to 20% of filtered proteins escape the PT under physiological conditions and are reabsorbed by the distal nephron. The renal distal tubule and collecting duct express SLC22A17, which mediates RME of filtered proteins that evade the PT but with limited capacity to prevent proteinuria under pathological conditions. The kidney also prevents excretion of filtered essential and nonessential transition metals, such as iron or cadmium, respectively, that are largely bound to proteins with high affinity, e.g., LCN2, transferrin, or metallothionein, or low affinity, e.g., microglobulins or albumin. Hence, increased uptake of transition metals may cause nephrotoxicity. Here, we assess the literature on SLC22A17 structure, topology, tissue distribution, regulation, and assumed functions, emphasizing renal SLC22A17, which has relevance for physiology, pathology, and nephrotoxicity due to the accumulation of proteins complexed with transition metals, e.g., cadmium or iron. Other putative renal functions of SLC22A17, such as its contribution to osmotic stress adaptation, protection against urinary tract infection, or renal carcinogenesis, are discussed.

Barakat syndrome.

Barakat syndrome, also known as HDR syndrome, is a clinically heterogenous, autosomal dominant rare genetic disease, which frequency is unknown. It is primarily caused by deletion of chromosome 10p14 or mutation of GATA3 gene, located on chromosome 10. Although this syndrome is phenotypically defined by its triad of HDR: hypoparathyroidism (H), deafness (D), renal disease (R), the literature identifies cases with different components, consisting of HD, DR, HR (1). The syndrome was first described by Amin J. Barakat et al. in 1977 in siblings with hypocalcemia and proteinuria (2). So far, about 180 cases have been reported in the worldwide medical literature (3). In this report we present our own case report of patient with Barakat syndrome with hypoparathyrodism, unilateral deafness and renal impairment.

ER stress and slit diaphragms: is there a connection?

Galloway-Mowat syndrome is a neurorenal syndrome that has been linked with defective transfer RNA and protein translation caused by variants in the multiprotein complex KEOPS. In the kidney, this syndrome seems to primarily affect the podocytes, but the pathogenesis has remained unclear. In this issue of Kidney International, Krausel et al. use Drosophila nephrocytes to link endoplasmic reticulum stress with defects in the slit diaphragm.

Cytoprotective remedies for ameliorating nephrotoxicity induced by renal oxidative stress.

AIMS: Nephrotoxicity is the hallmark of anti-neoplastic drug metabolism that causes oxidative stress. External chemical agents and prescription drugs release copious amounts of free radicals originating from molecular oxidation and unless sustainably scavenged, they stimulate membrane lipid peroxidation and disruption of the host antioxidant mechanisms. This review aims to provide a comprehensive collection of potential cytoprotective remedies in surmounting the most difficult aspect of cancer therapy as well as preventing renal oxidative stress by other means. MATERIALS AND METHODS: Over 400 published research and review articles spanning several decades were scrutinised to obtain the relevant data which is presented in 3 categories; sources, mechanisms, and mitigation of renal oxidative stress. KEY-FINDINGS: Drug and chemical-induced nephrotoxicity commonly manifests as chronic or acute kidney disease, nephritis, nephrotic syndrome, and nephrosis. Renal replacement therapy requirements and mortalities from end-stage renal disease are set to rapidly increase in the next decade for which 43 different cytoprotective compounds which have the capability to suppress experimental nephrotoxicity are described. SIGNIFICANCE: The renal system performs essential homeostatic functions that play a significant role in eliminating toxicants, and its accumulation and recurrence in nephric tissues results in tubular degeneration and subsequent renal impairment. Global statistics of the latest chronic kidney disease prevalence is 13.4 % while the end-stage kidney disease requiring renal replacement therapy is 4-7 million per annum. The remedial compounds discussed herein had proven efficacy against nephrotoxicity manifested consequent to impaired antioxidant mechanisms in preclinical models produced by renal oxidative stress activators.

Predicting Modifiers of Genotype-Phenotype Correlations in Craniofacial Development.

Most human birth defects are phenotypically variable even when they share a common genetic basis. Our understanding of the mechanisms of this variation is limited, but they are thought to be due to complex gene-environment interactions. Loss of the transcription factor Gata3 associates with the highly variable human birth defects HDR syndrome and microsomia, and can lead to disruption of the neural crest-derived facial skeleton. We have demonstrated that zebrafish gata3 mutants model the variability seen in humans, with genetic background and candidate pathways modifying the resulting phenotype. In this study, we sought to use an unbiased bioinformatic approach to identify environmental modifiers of gata3 mutant craniofacial phenotypes. The LINCs L1000 dataset identifies chemicals that generate differential gene expression that either positively or negatively correlates with an input gene list. These chemicals are predicted to worsen or lessen the mutant phenotype, respectively. We performed RNA-seq on neural crest cells isolated from zebrafish across control, Gata3 loss-of-function, and Gata3 rescue groups. Differential expression analyses revealed 551 potential targets of gata3. We queried the LINCs database with the 100 most upregulated and 100 most downregulated genes. We tested the top eight available chemicals predicted to worsen the mutant phenotype and the top eight predicted to lessen the phenotype. Of these, we found that vinblastine, a microtubule inhibitor, and clofibric acid, a PPAR-alpha agonist, did indeed worsen the gata3 phenotype. The Topoisomerase II and RNA-pol II inhibitors daunorubicin and triptolide, respectively, lessened the phenotype. GO analysis identified Wnt signaling and RNA polymerase function as being enriched in our RNA-seq data, consistent with the mechanism of action of some of the chemicals. Our study illustrates multiple potential pathways for Gata3 function, and demonstrates a systematic, unbiased process to identify modifiers of genotype-phenotype correlations.

Assessment of Intravascular Volume Status in Children with Nephrotic Edema Using Serum and Urinary Indices and Its Correlation with Inferior Vena Cava Collapsibility Index.

Identification of volume status in nephrotic syndrome (NS) is important but clinically challenging. Urinary and serum indices can be helpful in assessing the volume status and so can be inferior vena cava collapsibility index (IVCCI). This study was done to assess the serum and urinary indices in children with nephrotic edema and to correlate them with IVCCI for intravascular volume assessment. Fifty children with nephrotic edema and 47 children in remission were analyzed for blood and urine indices. Volume status was defined as overfilling or underfilling based on the biochemical indices and also by IVCCI. Eighty-four percent individuals among cases and 23% among controls had sodium retention (FENa < 0.5%). Among cases, 54% had primary sodium retention compared to 17% among controls (p = 0.0002). Hypovolemia was observed among 36% cases based on biochemical indices and in 20% cases as per IVCCI. Hypovolemia was significantly associated with low urinary sodium and low serum albumin.

Nicorandil protects podocytes via modulation of antioxidative capacity in acute puromycin aminonucleoside-induced nephrosis in rats.

Nephrotic syndrome, characterized by proteinuria and hypoalbuminemia, results from the dysregulation of glomerular podocytes and is a significant cause of end-stage kidney disease. Patients with idiopathic nephrotic syndrome are generally treated with immunosuppressive agents; however, these agents produce various adverse effects. Previously, we reported the renoprotective effects of a stimulator of the mitochondrial ATP-dependent K+ channel (MitKATP), nicorandil, in a remnant kidney model. Nonetheless, the cellular targets of these effects remain unknown. Here, we examined the effect of nicorandil on puromycin aminonucleoside-induced nephrosis (PAN) rats, a well-established model of podocyte injury and human nephrotic syndrome. PAN was induced using a single intraperitoneal injection. Nicorandil was administered orally at 30 mg/kg/day. We found that proteinuria and hypoalbuminemia in PAN rats were significantly ameliorated following nicorandil treatment. Immunostaining and ultrastructural analysis under electron microscopy demonstrated that podocyte injury in PAN rats showed a significant partial attenuation following nicorandil treatment. Nicorandil ameliorated the increase in the oxidative stress markers nitrotyrosine and 8-hydroxy-2-deoxyguanosine in glomeruli. Conversely, nicorandil prevented the decrease in levels of the antioxidant enzyme manganese superoxide dismutase in PAN rats. We found that mitochondrial Ca2+ uniporter levels in glomeruli were higher in PAN rats than in control rats, and this increase was significantly attenuated by nicorandil. We conclude that stimulation of MitKATP by nicorandil reduces proteinuria by attenuating podocyte injury in PAN nephrosis, which restores mitochondrial antioxidative capacity, possibly through mitochondrial Ca2+ uniporter modulation. These data indicate that MitKATP may represent a novel target for podocyte injury and nephrotic syndrome.NEW & NOTEWORTHY Our findings suggest that the mitochondrial Ca2+ uniporter may be an upstream regulator of manganese superoxide dismutase and indicate a biochemical basis for the interaction between the ATP-sensitive K+ channel and Ca2+ signaling. We believe that our study makes a significant contribution to the literature because our results indicate that the ATP-sensitive K+ channel may be a potential therapeutic target for podocyte injury and nephrotic syndrome.

Functional characterization of a novel TP53RK mutation identified in a family with Galloway-Mowat syndrome.

Galloway-Mowat syndrome (GAMOS) is a very rare condition characterized by early-onset nephrotic syndrome and microcephaly with variable neurologic features. While considerable genetic heterogeneity of GAMOS has been identified, the majority of cases are caused by pathogenic variants in genes encoding the four components of the Kinase, endopeptidase, and other proteins of small size (KEOPS) complex, one of which is TP53RK. Here we describe a 3-year-old male with progressive microcephaly, neurodevelopmental deficits, and glomerular proteinuria. He was found to carry a novel homozygous TP53RK missense variant, c.163C>G (p.Arg55Gly), which was considered as potentially disease-causing. We generated a morpholino tp53rk knockdown model in Xenopus laevis showing that the depletion of endogenous Tp53rk caused abnormal eye and head development. This phenotype could be rescued by the expression of human wildtype TP53RK but not by the c.163C>G mutant nor by another previously described GAMOS-associated mutant c.125G>A (p.Gly42Asp). These findings support the pathogenic role of the novel TP53RK variant.

[Laparoscopic pyeloplasty combined with ultrasonic lithotripsy via nephroscope for treatment of ureteropelvic junction obstruction with renal calculi].

OBJECTIVE: To investigate the efficacy and safety of laparoscopic pyeloplasty combined with ultrasonic lithotripsy via nephroscope in the treatment of ureteropelvic junction obstruction (UPJO) with renal calculi. METHODS: From June 2016 to January 2022, eight patients including five males and three females underwent laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F(1F≈0.33 mm) nephroscope in Peking University People' s Hospital. The age ranged from 23-51 years (mean: 40.5 years) and the body mass index (BMI) ranged from 18.8-32.4 kg/m2 (mean 27.0 kg/m2). The lesion located on the left side in all of the eight patients. Two patients had solitary kidney and one patient had horseshoe kidney. Solitary stone was seen in one patient and the other seven patients suffered multiple stones, with two patients had staghorn stones. The largest diameter of stones ranged from 0.6-2.5 cm (mean: 1.5 cm). CT or ultrasound showed that moderate nephrosis was seen in five patients and severe nephrosis was seen in three patients. During surgery, after exposure of renal pelvis and proximal ureter, a small incision of 1.5 cm was performed in the anterior wall of the renal pelvis, and a 19.5F nephroscope was introduced into renal pelvis through laparoscopic trocar and renal pelvis incision. Stones were fragmented and sucked out by 3.3 mm ultrasonic probe placed through nephroscope. After stones were removed, modified laparoscopic pyeloplasty was performed. RESULTS: Surgery was successfully completed in all of the eight patients without conversion to open surgery. The operation time ranged from 160-254 min (mean 213 min) and the time of nephroscopic management time was 25-40 min (mean: 33 min). The hemoglobin was decreased by 3-21 g/L (mean: 10.3 g/L). The stone-free rate was 75% (6/8 cases), stones were incompletely removed in two patients due to abnormal intrarenal structure. The modified Clavien classification system (MCCS) grade ⅢA complication occurred in one patient postoperatively, which was nephrosis due to intrarenal bleeding, and nephrostomy was performed. With the mean follow-up of 30 months (ranged from 2-68 months), there was no evidence of obstruction in all the patients, and one patient underwent percutaneous nephrolithotomy to treat residual calculi. CONCLUSION: Laparoscopic pyeloplasty combined with ultrasonic lithotripsy via 19.5F nephroscope is feasible and safe, and could be a complementary method to treat UPJO and renal calculi.

Prevalence and correlates of depressive and anxiety symptoms among adults in Guangdong Province of China: A population-based study.

AIMS: To examine the prevalence and health correlates of depressive and anxiety symptoms among adults living in Guangdong province of China with a large population and rapid urbanization. METHODS: The Guangdong Sleep and Psychosomatic Health Survey was conducted from September to November in 2019, which was a population-based study with a representative sample of adults aged 18-85 years. Multistage stratified cluster sampling was used. A total of 13,768 inhabitants were included and face-to-face interviewed using standardized assessment tools. Depressive and anxiety symptoms were evaluated using the Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder Scale (GAD-7), respectively. RESULTS: The weighted prevalence rates of depressive and anxiety symptoms were 8.6% (95% confidence interval [CI]: 8.0%-9.3%) and 6.0% (95%CI, 5.4%-6.5%) respectively. People who have never married, irregular diet rhythm, hardly exercise, poorer sleep, alcohol consumption, chronic diseases and being unemployment and retirement were more likely to suffer depressive and anxiety symptoms. Moreover, the prevalence of depressive symptoms was significantly higher in those suffering from cardiovascular disease (Odds ratio[OR]:3.89, 95%CI: 1.77-8.54), chronic nephrosis (OR:3.89, 95%CI: 1.52-9.94), hyperlipidemia (OR:2.68, 95%CI: 1.57-4.59), anemia (OR:1.96, 95%CI: 1.33-2.89) and arthritis (OR:1.93, 95%CI: 1.17-3.16). The prevalence of anxiety symptoms was evidently greater within patients with cardiovascular disease (OR:3.15, 95%CI: 1.39-7.14), chronic nephrosis (OR: 2.89, 95%CI: 1.22-6.83), hyperlipidemia (OR:2.27, 95%CI: 1.20-4.29) and diabetes (OR:1.99, 95%CI: 1.15-3.44). CONCLUSIONS: Depressive and anxiety symptoms are commonly found in patients with chronic diseases. Given these adverse outcomes on health, health professionals should pay more attention to depressive and anxiety problems in health care for high-risk population.

Rhabdomyolysis, myoglobinuric nephrosis, and crystalline nephropathy in a captive bottlenose dolphin.

A 5-y-old female bottlenose dolphin (Tursiops truncatus) from an aquarium in Japan had clinical signs of anorexia, vomiting, and bradykinesia. Enrofloxacin and lactated Ringer solution were administered for treatment of bacterial infection and for rehydration. Elevations of creatine kinase and aspartate aminotransferase activities were detected on day 4 of treatment, indicating that rhabdomyolysis had developed on day 3. On day 5, serum creatinine and urea concentrations increased and remained high throughout the remaining treatment; the dolphin died on day 16. Postmortem examination revealed massive necrosis of the longissimus dorsi muscles. Histologic examination revealed extensive necrosis of skeletal myofibers, multifocal renal tubular necrosis with intratubular casts and crystals, and suppurative bronchopneumonia. The renal casts labeled positively with anti-myoglobin antibody; expression of aquaporin-1 was decreased in renal tubules compared to normal kidney tissue. To our knowledge, this description of clinicopathologic findings of rhabdomyolysis leading to acute kidney injury with concomitant crystalline nephropathy has not been reported previously in a bottlenose dolphin.

Enfermedad de cambios mínimos cortico-resistente e hipotiroidismo. Reporte de caso / Steroid-resistant minimal change disease and hypothyroidism: Case report

Introducción: La enfermedad de cambios mínimos es una causa rara de síndrome nefrótico en el adulto, y su relación con el hipotiroidismo es más rara aún. Se considera que esta patología renal responde favorablemente al manejo con glucocorticoides y tiene una baja frecuencia de resistencia. Su abordaje hoy en día es objeto de investigación. Objetivo: Describir una rara etiología de síndrome nefrótico en el adulto con presentación, tratamiento y desenlace infrecuentes. Presentación del caso: Paciente femenino de 53 años quien inicia con síndrome nefrótico por enfermedad de cambios mínimos cortico-resistente y su asociación con un hipotiroidismo descontrolado, quien requiere manejo con rituximab y control de la enfermedad endocrinológica asociada, como enfermedad de base. Conclusiones: En este caso clínico se muestra como las enfermedades citadas pueden coexistir y el tratamiento en conjunto es necesario. El establecimiento de nuevas terapias en la población adulta como el rituximab podría mostrar beneficio, como en este caso. Sin embargo, aún existe la necesidad de estudios de mayor evidencia que validen firmemente la efectividad de los diferentes tratamientos en este tipo de pacientes.

Introduction: Minimal change disease is a rare cause of nephrotic syndrome in adults, and its association with hypothyroidism is even more exceptional. This renal pathology is considered to respond favorably to glucocorticoid management and has a low resistance frequency. How to approach this disease is currently under investigation. Objective: To describe a rare etiology of adult nephrotic syndrome with unusual presentation, treatment, and outcome. Case presentation: A 53 years-old female patient who initially experienced nephrotic syndrome due to steroid-resistant minimal change disease, which was also associated with uncontrolled hypothyroidism. She required management with rituximab and control of the associated endocrinological disease, which was considered as the underlying disease. Conclusions: This clinical case shows (i) how the two aforementioned diseases can coexist and (ii) that a joint treatment is necessary. Establishing new therapies may be beneficial for adult populations, such as the benefits seen in this case with the use of rituximab. However, further studies are needed to strongly validate the effectiveness of the different treatments for these types of patients.