Podocyte-specific Nup160 knockout mice develop nephrotic syndrome and glomerulosclerosis.

More than 60 monogenic genes mutated in steroid-resistant nephrotic syndrome (SRNS) have been identified. Our previous study found that mutations in nucleoporin 160 kD (NUP160) are implicated in SRNS. The NUP160 gene encodes a component of the nuclear pore complex. Recently, two siblings with homozygous NUP160 mutations presented with SRNS and a nervous system disorder. However, replication of nephrotic syndrome (NS)-associated phenotypes in a mammalian model following loss of Nup160 is needed to prove that NUP160 mutations cause SRNS. Here, we generated a podocyte-specific Nup160 knockout (Nup160podKO) mouse model using CRISPR/Cas9 and Cre/loxP technologies. We investigated NS-associated phenotypes in these Nup160podKO mice. We verified efficient abrogation of Nup160 in Nup160podKO mice at both the DNA and protein levels. We showed that Nup160podKO mice develop typical signs of NS. Nup160podKO mice exhibited progression of proteinuria to average albumin/creatinine ratio (ACR) levels of 15.06 ± 2.71 mg/mg at 26 weeks, and had lower serum albumin levels of 13.13 ± 1.34 g/l at 30 weeks. Littermate control mice had urinary ACR mean values of 0.03 mg/mg and serum albumin values of 22.89 ± 0.34 g/l at the corresponding ages. Further, Nup160podKO mice exhibited glomerulosclerosis compared with littermate control mice. Podocyte-specific Nup160 knockout in mice led to NS and glomerulosclerosis. Thus, our findings strongly support that mutations in NUP160 cause SRNS. The newly generated Nup160podKO mice are a reliable mammalian model for future study of the pathogenesis of NUP160-associated SRNS.

Growth hormone treatment in pre-pubertal short Chinese children with chronic kidney disease prior to transplantation.

BACKGROUND: The effect of recombinant human GH (rhGH) in Chinese children with chronic kidney disease (CKD) is unclear. METHODS: This was a 52-week, multicenter, randomized, open-label, negative-controlled phase 3 study. Prepubertal subjects were randomized 1:1 to either daily subcutaneous injections of rhGH 0.05 mg/kg/day or no treatment for 52 weeks. RESULTS: A total of 68 subjects with a mean age of 7.8 ± 3.27 years were enrolled. At week 52, the height standard deviation score (HT-SDS) in the treated group increased by 0.75 ± 0.58, which was significantly higher compared with 0.17 ± 0.47 in the untreated group (least squares mean 0.58, 95% confidence interval, 0.32-0.84; P < 0.001). At week 52, significant improvements were observed in other growth parameters (height velocity [P < 0.001]), insulin-like growth factor 1 (IGF-1) SDS [P < 0.001], IFG-1/insulin-like growth factor binding protein-3 molar ratio [P < 0.001], and height [P < 0.001]) compared with the untreated control. Seven patients reported treatment-related adverse events (TRAEs) and most TRAEs were mild in severity. Most subjects recovered without further intervention. CONCLUSIONS: Daily rhGH for 52 weeks in children with CKD-induced growth retardation significantly improved HT-SDS and other growth parameters without compromising safety. IMPACT: The efficacy and safety of growth hormone (GH) therapy in Chinese children with chronic kidney disease (CKD) are unclear. This study found that giving short stature Chinese children with CKD daily recombinant human growth hormone (rhGH) for 52 weeks improved growth parameters without compromising safety. This study's information can give physicians the confidence to treat these patients in their clinical practice.

Clinicopathologic features in childhood-onset lupus nephritis with antineutrophil cytoplasmic antibody positivity--a multi-center retrospective study.

BACKGROUND: Positive antineutrophil cytoplasmic antibody (ANCA) serology in adult-onset lupus nephritis (LN) is associated with more active disease and distinct renal pathology, but data with respect to childhood-onset LN remain scarce. Here, we aimed to determine the impact of positive ANCA serology on clinical and histopathologic features and renal outcomes in children with LN from multiple centers. METHODS: Clinical and histopathologic data of 61 ANCA-positive and 330 ANCA-negative LN children (1

Polystyrene nanoplastics promote the apoptosis in Caco-2 cells induced by okadaic acid more than microplastics.

Microplastics (MPs) are widespread in the environment and can be ingested through food, water, and air, posing a threat to human health. In addition, MPs can have a potential combined effect with other toxic compounds. Polystyrene (PS) has been shown to enhance the cytotoxicity of okadaic acid (OA). However, it remains unclear whether this enhancement effect is related to the size of PS particles. In this study, we investigated the mechanism of the combined effect of PS microplastics (PS-MPs) or PS nanoplastics (PS-NPs) and OA on Caco-2 cells. The results indicated that PS-NPs enhanced the cytotoxicity of OA and induced endoplasmic reticulum (ER) stress-mediated apoptosis in Caco-2 cells, compared to PS-MPs. Specifically, PS-NPs and OA cause more severe oxidative stress, lactate dehydrogenase (LDH) release, and mitochondrial membrane depolarization. Furthermore, it induced intracellular calcium overload through store-operated channels (SOCs) and activated the PERK/ATF-4/CHOP pathway to cause ER stress. ER stress promoted mitochondrial damage and finally activated the caspase family to induce apoptosis. This study provided an indirect basis for the assessment of the combined toxicity of MPs or NPs with OA.

Long-term nephrotic syndrome recurrence risk of kidney transplantation in two siblings with ADCK4-associated glomerulopathy.

BACKGROUND: Mutations in the ADCK4 gene cause steroid-resistant nephrotic syndrome (NS), namely ADCK4-associated glomerulopathy. Reportedly, 38.5% of patients with ADCK4-associated glomerulopathy had end-stage renal disease (ESRD) at the time of diagnosis of ADCK4-associated glomerulopathy, requiring renal replacement therapy, such as dialysis and kidney transplantation. However, long-term NS recurrence risk of kidney transplantation in patients with ADCK4-associated glomerulopathy is unknown. METHODS: The clinical data and mutations in ADCK4 of two siblings with steroid-resistant NS were collected. The long-term prognosis of the two siblings who received kidney transplantation was evaluated. RESULTS: We describe two siblings with ADCK4-associated glomerulopathy who received deceased donor kidney transplantation and showed no clinical evidence of recurrence of NS during more than 10 years of follow-up. CONCLUSIONS: This suggests that long-term NS recurrence risk of kidney transplantation is low in patients with ADCK4-associated glomerulopathy who progress to ESRD.

Mutations in NUP160 Are Implicated in Steroid-Resistant Nephrotic Syndrome.

BACKGROUND: Studies have identified mutations in >50 genes that can lead to monogenic steroid-resistant nephrotic syndrome (SRNS). The NUP160 gene, which encodes one of the protein components of the nuclear pore complex nucleoporin 160 kD (Nup160), is expressed in both human and mouse kidney cells. Knockdown of NUP160 impairs mouse podocytes in cell culture. Recently, siblings with SRNS and proteinuria in a nonconsanguineous family were found to carry compound-heterozygous mutations in NUP160. METHODS: We identified NUP160 mutations by whole-exome and Sanger sequencing of genomic DNA from a young girl with familial SRNS and FSGS who did not carry mutations in other genes known to be associated with SRNS. We performed in vivo functional validation studies on the NUP160 mutations using a Drosophila model. RESULTS: We identified two compound-heterozygous NUP160 mutations, NUP160R1173× and NUP160E803K . We showed that silencing of Drosophila NUP160 specifically in nephrocytes (fly renal cells) led to functional abnormalities, reduced cell size and nuclear volume, and disorganized nuclear membrane structure. These defects were completely rescued by expression of the wild-type human NUP160 gene in nephrocytes. By contrast, expression of the NUP160 mutant allele NUP160R1173× completely failed to rescue nephrocyte phenotypes, and mutant allele NUP160E803K rescued only nuclear pore complex and nuclear lamin localization defects. CONCLUSIONS: Mutations in NUP160 are implicated in SRNS. Our findings indicate that NUP160 should be included in the SRNS diagnostic gene panel to identify additional patients with SRNS and homozygous or compound-heterozygous NUP160 mutations and further strengthen the evidence that NUP160 mutations can cause SRNS.

Spectrum of mutations in Chinese children with steroid-resistant nephrotic syndrome.

BACKGROUND: The aim of this study was to elucidate whether genetic screening test results of pediatric patients with steroid-resistant nephrotic syndrome (SRNS) vary with ethnicity. METHODS: Using high-throughput DNA sequencing, 28 nephrotic syndrome-related genes were analyzed in 110 chil-dren affected by SRNS and 10 children with isolated proteinuria enrolled by 5 centers in China (67 boys, 53 girls). Their age at disease onset ranged from 1 day to 208 months (median, 48.8 months). Patients were excluded if their age at onset of disease was over 18 years or if they were diagnosed as having Alport syndrome. RESULTS: A genetic etiology was identified in 28.3% of our cohort and the likelihood of establishing a genetic diagnosis decreased as the age at onset of nephrotic syndrome increased. The most common mutated genes were ADCK4 (6.67%), NPHS1 (5.83%), WT1 (5.83%), and NPHS2 (3.33%), and the difference in the frequencies of ADCK4 and NPHS2 mutations between this study and a study on monogenic causes of SRNS in the largest international cohort of 1,783 different families was significant. A case of congenital nephrotic syndrome was attributed to a homozygous missense mutation in ADCK4, and a de novo missense mutation in TRPC6 was detected in a case of infantile nephrotic syndrome. CONCLUSIONS: Our results showed that, in the first and the largest multicenter cohort of Chinese pediatric SRNS reported to date, ADCK4 is the most common causative gene, whereas there is a low prevalence of NPHS2 mutations. Our data indicated that the genetic testing results for pediatric SRNS patients vary with different ethnicities, and this information will help to improve management of the disease in clinical practice.

Early plasma exchange for treating ricin toxicity in children after castor bean ingestion.

Plasma exchange (PE) for the treatment of ricin toxicity has not been previously reported. Here we describe the use of PE to treat children who experienced ricin toxicity after ingesting castor beans. Seven children (median age: 8.1 years) who consumed castor beans (median: 5 beans) were treated with PE. All had bradycardia and sinus arrhythmia, and most had experienced episodes of vomiting and/or diarrhea. PE settings were blood flow, 50-80 mL/min; PE rate, 600-800 mL/h; volume of exchange, 1440-1950 mL. Median time from ingestion to PE was 73 h. All clinical symptoms disappeared and vital signs rapidly returned to normal after PE; no severe organ dysfunction occurred. All children were discharged and recovered uneventfully. Concentrations of all serum biochemical parameters significantly decreased immediately after PE. Some, but not all, of these parameters were also significantly decreased at 48 and 72 h after PE compared with before PE. Our findings suggest that PE can be an effective early intervention in the treatment of ricin toxicity due to castor bean ingestion.

[Mutational analysis of MYO1E in Chinese children with familial steroid-resistant nephrotic syndrome].

OBJECTIVE: Steroid-resistant nephrotic syndrome (SRNS) with MYO1E mutations has been identified as autosomal recessive focal segmental glomerulosclerosis (FSGS). To date, only two homozygous mutations in the MYO1E gene were reported in three families with FSGS. This study aimed to examine mutations in the MYO1E gene in children with familial SRNS in the Han Chinese ethnic group. METHODS: Between 2005 and 2010, peripheral blood samples were collected from the probands, their siblings and parents of four families with autosomal recessive SRNS in the Han Chinese ethnic group. Four probands were studied from nine patients. The mutational analysis of MYO1E was performed by polymerase chain reaction and direct DNA sequencing. Fifty-nine healthy volunteers with normal urine analysis were included as controls. RESULTS: Twenty-five MYO1E variants in the prohands from 4 families with SRNS were identified in this study. Among them, 24 variants were found in NCBI dbSNP. One heterozygous mutation IVS21-85G>A was found in the prohand from Family D, whereas it was absent in 59 normal Chinese controls. No splice site change caused by IVS21-85G>A was reported by analysis with NetGene2. CONCLUSIONS: MYO1E mutations are not a major cause of Chinese familial SRNS in this study.

A child with isolated nephrotic syndrome and WT1 mutation presenting as a 46, XY phenotypic male.

Mutations in the WT1 gene can lead to Denys-Drash syndrome or Frasier syndrome and can also cause isolated nephrotic syndrome (NS). Most patients with isolated NS caused by WT1 mutations present as 46, XX phenotypic females. There have been two cases with an onset age younger than 3 years with isolated NS caused by WT1 mutations presenting as 46, XY phenotypic males. We present a 46, XY phenotypic male patient with isolated NS and end-stage renal disease (ESRD) at the age of 6.3 years. He had normal male external genitalia with normal penis length and soft and normal volume of both testes. A mutation, 1051A>G (K351E), in exon 8 of WT1 was identified in the patient. After starting hemodialysis, manifestations of hypertension and renal failure improved, but he died at 6.8 years of age as a result of respiratory failure and heart failure. Our study supports the necessity of searching for mutations in WT1 in 46, XY phenotypic male patients with isolated NS and ESRD.

Corrigendum: Phosphate solubilizing microorganisms as a driving force to assist mine phytoremediation.

[This corrects the article DOI: 10.3389/fbioe.2023.1201067.].

Scalp Tumor and Hydroureteronephrosis in Patients with Nephronophthisis and Homozygous NPHP1 Deletion.

Homozygous deletion of NPHP1 can lead to isolated nephronophthisis (NPHP) and syndromic disorders. However, the phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1 has not been reported. Clinical data, laboratory results, and genetic testing of 4 NPHP patients were collected. Examination of their eyes, heart, and urinary tract and of their hepatobiliary, skeletal, and central nervous systems was evaluated. Isolated NPHP was observed in 1 case, and syndromic disorders were observed in the other 3 patients. Their syndromic disorders showed NPHP combined with central nervous system defects, eye involvement, scalp tumor, arachnoid cyst, or hydroureteronephrosis. Large homozygous deletions covering the whole NPHP1 gene locus were identified in all 4 patients. We report a novel phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1, paving an avenue for further research on NPHP1-associated deformity in the skin and the urinary system.

The Clinical and Genetic Features in Chinese Children With Steroid-Resistant or Early-Onset Nephrotic Syndrome: A Multicenter Cohort Study.

Steroid-resistant nephrotic syndrome (SRNS) is one of the major causes of end-stage kidney disease (ESKD) in children and young adults. For approximately 30% of children with SRNS results from a genetic cause. In this study, genotype-phenotype correlations in a cohort of 283 pediatric patients with SRNS or early-onset NS (nephrotic syndrome presenting within the first year of life) from 23 major pediatric nephrology centers in China were analyzed. All patients were performed with next-generation sequencing and Sanger sequencing. The overall mutation detection rate was 37.5% (106 of 283 patients). WT1 was the most frequently detected mutation, followed by NPHS1, NPHS2, and ADCK4, and these four major causative genes (WT1, NPHS1, NPHS2, and ADCK4) account for 73.6% of patients with monogenic SRNS. Thirteen of 106 individuals (12.3%) carried mutations in ADCK4 that function within the coenzyme Q10 biosynthesis pathway. In the higher frequently ADCK4-related SRNS, two mutations, c.737G>A (p.S246N) and c.748G>C (p.D250H), were the most prevalent. Our study provides not only definitive diagnosis but also facilitate available targeted treatment for SRNS, and prediction of prognosis and renal outcome. Our indications for genetic testing are patients with FSGS, initial SRNS, cases of positive family history or those with extra-renal manifestations.

Taurine represses age-associated gut hyperplasia in Drosophila via counteracting endoplasmic reticulum stress.

As they age, adult stem cells become more prone to functional decline, which is responsible for aging-associated tissue degeneration and diseases. One goal of aging research is to identify drugs that can repair age-associated tissue degeneration. Multiple organ development-related signaling pathways have recently been demonstrated to have functions in tissue homeostasis and aging process. Therefore, in this study, we tested several chemicals that are essential for organ development to assess their ability to delay intestinal stem cell (ISC) aging and promote gut function in adult Drosophila. We found that taurine, a free amino acid that supports neurological development and tissue metabolism in humans, represses ISC hyperproliferation and restrains the intestinal functional decline seen in aged animals. We found that taurine represses age-associated ISC hyperproliferation through a mechanism that eliminated endoplasmic reticulum (ER) stress by upregulation of the target genes of unfolded protein response in the ER (UPRER ) and inhibiting the c-Jun N-terminal kinase (JNK) signaling. Our findings show that taurine plays a critical role in delaying the aging process in stem cells and suggest that it may be used as a natural compound for the treatment of age-associated, or damage-induced intestinal dysfunction in humans.

Effects of alternative remission criteria on outcome of pediatric proliferative lupus nephritis: a multi-center retrospective study of pediatric proliferative lupus nephritis.

OBJECTIVES: To observe the induction efficacy of mycophenolate mofetil and cyclophosphamide under different complete remission (CR) criteria in children with proliferative lupus nephritis, and to further explore the factors influencing the judgment of remission. METHODS: From 2003 to 2019, children who diagnosed proliferative lupus nephritis underwent induction therapy of MMF or CYC in three hospitals were consecutively collected. Based on this population, we compared CR rates between two groups under six CR criteria selected from related recommendations and clinical trials. Then degrees and impact factors of disagreement among CR rates evaluated by selected criteria would be analyzed by Kappa test and multivariable logistic-regression models. RESULTS: A total of 161 children were included in this study, 27 patients received induction therapy of mycophenolate mofetil (MMF) and 134 patients recieved cyclophosphamide (CYC). Under different CR criteria, CR rates in MMF group fluctuated between 18.5%-74.1% and that in CYC group ranged from 16.4%-73.9%. Moreover, comparison between the two drugs in induction treatment under different criteria showed an opposite trend in efficacy. The results of six criteria were inconsistent, with pair-to-pair Kappa values ranging from 0.118 to 0.858. The most important factors leading to disagreement in judgment were urinary protein and urinary red blood cells. CONCLUSIONS: The definition of complete response, especially the factors of the urinary protein and urinary red blood cells, significantly impacts the clinical judgment of children with lupus nephritis.

R168H and V165X mutant podocin might induce different degrees of podocyte injury via different molecular mechanisms.

A lot of mutations of podocin, a key protein of podocyte slit diaphragm (SD), have been found both in hereditary and sporadic focal segmental glomeruloscleorosis (FSGS). Nevertheless, the mechanisms of podocyte injury induced by mutant podocins are still unclear. A compound heterozygous podocin mutation was identified in our FSGS patient, leading to a truncated (podocin (V165X)) and a missense mutant protein (podocin (R168H)), respectively. Here, it was explored whether and how both mutant podocins induce podocyte injury in the in vitro cultured podocyte cell line. Our results showed that podocin (R168H) induced more significant podocyte apoptosis and expression changes in more podocyte molecules than podocin (V165X). Podocyte injury caused by the normal localized podocin(V165X) was effectively inhibited by TRPC6 knockdown. The abnormal retention of podocin(R168H) in endoplasmic reticulum (ER) resulted in the mis-localizations of other critical SD molecules nephrin, CD2AP and TRPC6, and significantly up-regulated ER stress markers Bip/grp78, p-PERK and caspase-12. These results implicated that podocin (R168H) and podocin (V165X) induced different degrees of podocyte injury, which might be resulted from different molecular mechanisms. Our findings provided some possible clues for further exploring the pharmacological targets to the proteinuria induced by different mutant podocins.

WT1 gene mutations in Chinese children with early onset nephrotic syndrome.

In Chinese children with steroid-resistant nephrotic syndrome (SRNS), it was reported that NPHS2 mutation was detected in 4.3%, which was lower than that in Caucasians (10-30%). However, there were no data on WT1 mutation in nephrotic syndrome (NS), especially in early-onset NS of Chinese children. Thus, a study, which enrolled 36 Chinese children with early-onset (before 3 y old) NS and steroid resistance if failing steroid therapy (early-group), was conducted. As control, 35 children with SRNS and with disease onset age after 3 y old were also analyzed (control-group). WT1 gene was examined by PCR and direct sequencing. The result showed that in the early-group 6/36 (16.7%) were detected with WT1 mutations. Further analysis according to different onset age revealed that the mutation detection rates of WT1 were 26.3% (5/19), 6.3% (1/16), and 0 (0/1) in children younger than 1 y, 1-2 y, and 2-3 y, respectively. In control-group, no WT1 (0/35) mutation was detected. WT1 mutation combined with NPHS2 variant was detected in a girl. In conclusion, WT1 mutations seemed more common in Chinese children with early-onset NS.