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.

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.

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

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

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<age≤18 years) retrospectively enrolled from three pediatric nephrology centers were analyzed. Among them, 217 children were followed and survival analysis was performed.

RESULTS

Among 61 ANCA-positive LN children, 86.9% of them had antimyeloperoxidase antibodies. Both ANCA-positive and ANCA-negative children had high disease activities with median SLEDAI-2K of 16 (13, 20). Hematuria was more prominent (urinary RBC +++ ∼ ++++: 45.9% vs 26.7%, p = 0.011), while fever (42.6% vs. 58.2%, p = 0.035), alopecia (3.3% vs. 14.5%, p = 0.019), photosensitivity (0% vs. 8.2%, p = 0.013), and pleurisy (4.9% vs. 15.8%, p = 0.026) were less common in ANCA-positive children. Higher proportions of segmental sclerosis (23.7% vs. 9.8%, p = 0.025), crescentic formation (36.4% vs. 16.3%, p = 0.009), and capillary wall thickening (24.5% vs. 11.0%, p = 0.01) were observed in biopsies of ANCA-positive children. Long-term renal survival did not differ significantly between two groups (p = 0.300).

CONCLUSIONS

Positive ANCA serology in LN children was associated with different clinical and histopathologic features compared to those with negative ANCA serology. Further studies are needed to clarify the pathogenic role of ANCAs in childhood-onset LN and confirm their association with prognosis.

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.

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.

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.

CuI-Promoted [3+2] Cycloaddition/oxidation to construct Pyrrolo[2,1a]isoquinolino-quinones from naphthoquinone and tetrahydroisoquinoline

The copper-catalyzed three-component one-pot 1,3-dipole cycloaddition/oxidation has been developed to construct Pyrrolo[2,1-a]isoquinolinoquinone derivatives with environmentally friendly oxygen as the oxidant. The products Pyrrolo[2,1-a]isoquinolinoquinones were obtained from the naturally available raw materials tetrahydroisoquinoline, 1,4-naphthoquinone and benzaldehyde with medium yields.

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.

Application of Chlorophyte ChlB Gene and Cyanophyte NIES Gene in the Detection of Drowning-Related Plankton

Abstract

Objective To construct a polymerase chain reaction-capillary electrophoresis （PCR-CE） detection method using ChlB gene and NIES gene, investigate the method's specificity and sensitivity, and to evaluate its application value in drowning diagnosis. Methods The specific primers ChlB and NIES were designed for the conserved sequence of chlorophyte ChlB gene and cyanophyte NIES gene in GenBank to construct PCR-CE detection method; 50 species of standard DNA samples were amplified; the sensitivity was determined by gradient concentration detection of positive standard samples; 25 actual cadaver lung tissue samples （drowned： 20, natural death： 5） were detected, and the simultaneous detection results of microwave digestion-vacuum filtration-automated scanning electron microscopy （MD-VF-Auto SEM） were simultaneously compared. Results The minimum DNA detection concentration of primers ChlB and NIES was 0.161 ng and 0.109 ng, respectively, which could specifically amplify chlorophyte （Chlorella pyrenoidosa） and cyanophyte ［Microcystis aeruginosa （producing and not producing toxin）］ widespread in water. The product fragments were 156 bp and 182 bp, respectively. The results of non-drowning tissues were negative. Conclusion This method has high sensitivity and specificity. It can be applied to the detection of plankton related to drowning and combined with MD-VF-Auto SEM method, can increase the detection range of plankton related to drowning and improve the evidence power of drowning diagnosis.

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 (UPR^ER) 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.

Nondestructive Strategy to Effectively Enhance the Interfacial Adhesion of PBO/Epoxy Composites

Low interfacial adhesion seriously limits the wide application of PBO fiber in composites. To solve this problem, a novel hierarchical reinforcement strategy was developed by introducing epoxy sizing, nanoreinforcement of amino-functionalized silicon dioxide (SiO₂-NH₂), and an interfacial compatibilizer of 2,6-bis(2-hydroxy-4-aminophenyl) benzobisoxazole (HABO) onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a facile dip-coating approach. SiO₂-NH₂ and HABO were uniformly dispersed in epoxy sizing, forming an active interface layer. On this basis, wettability, surface roughness of the PBO fiber, and compatibility with the resin matrix were significantly improved, which gave 88.4 and 40.4% enhancement in the interfacial shear strength and interlaminar shear strength of the corresponding composites, respectively. Moreover, it should be noted that the outstanding mechanical and thermal properties of the PBO fiber were not impaired during the sizing treatment. In summary, our work provides an effective and damage-free approach to improve the interfacial adhesion of PBO/epoxy composites.

Peroxisome Elevation Induces Stem Cell Differentiation and Intestinal Epithelial Repair

Epithelial-repair-dependent mucosal healing (MH) is associated with a more favorable prognosis for patients with inflammatory bowel disease (IBD). MH is accomplished via repair and regeneration of the intestinal epithelium. However, the mechanism underlying MH is ill defined. We found a striking upregulation of peroxisomes in the injured crypts of IBD patients. By increasing peroxisome levels in Drosophila midguts, we found that peroxisome elevation enhanced RAB7-dependent late endosome maturation, which then promoted stem and/or progenitor-cell differentiation via modulation of Janus Kinase (JAK) and Signal Transducer and Activator of Transcription (STAT)-SOX21A signaling. This in turn enhanced ISC-mediated regeneration. Importantly, RAB7 and SOX21 were upregulated in the crypts of IBD patients. Moreover, administration of drugs that increased peroxisome levels reversed the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice. This study demonstrates a peroxisome-mediated epithelial repair mechanism, which opens a therapeutic avenue for the enhancement of MH in IBD patients.

A simple method for detecting and quantifying microplastics utilizing fluorescent dyes - Safranine T, fluorescein isophosphate, Nile red based on thermal expansion and contraction property

Microplastics (particle size <5 mm) are an emerging contaminant for aquatic environmental, which have attracted increasing attention in worldwide range. In this study, an improved fluorescent staining method for detection and quantification of microplastics was developed based on thermal expansion and contraction. This method is effective in detection of polyethylene, polystyrene, polyvinyl chloride and polyethylene terephthalate plastic particles. In order to avoid error statistics caused by pretreatment, various characterizations of microplastics were measured after heated, such as microstructure, compositions and thermostability. The results showed that there was no significant damage to microplastics even under heating condition at 75 °C for 30 min, and the stained microplastics had strong stability for up to two months. Moreover, this method has been successfully applied to the quantification of microplastics in biological samples and result showed there were about 54 particles g^-1 (dry weight) microplastics in the Sipunculus nudus. This new method provides a reliable method for quantitative analysis of microplastics in environment and biological tissue.

[The 8th edition of the American Joint Committee on Cancer staging system provide improved prognostic accuracy in T1-2N1M0 postmastectomy breast cancer patients]

Objective: To validate whether the prognostic stage groups by the 8th edition of the American Joint Committee on Cancer (AJCC) staging system provides improved prognostic accuracy in T1-2N1M0 postmastectomy breast cancer patients compared to 7th edition. Methods: a total of 1 823 female patients with T1-2N1M0 breast cancer who underwent mastectomy and axillary lymph node dissection without neoadjuvant chemotherapy were analyzed and restaged according to 8th edition. Univariate analysis of prognostic factors was evaluated by using log-rank test. Multivariate analysis was estimated by using the Cox proportional hazards model. The prognostic accuracy of the two staging systems was compared using receiver operating characteristic (ROC) analyses and the concordance index (C-index). Results: 5-year locoregional recurrence rate (LRR) for the whole group was 6.0%, 5-year distant metastasis (DM) rate was 11.5%, 5-year disease-free survival (DFS) was 85.0%, and 5-year overall survival (OS) was 93.1%. Cox analysis showed that 7th edition of the AJCC staging system and progesterone receptor status were independent risk factors for LRR, DM, DFS and OS (P<0.05). Compared with stage by 7th edition, 1 278(70.1%) were assigned to a different prognostic stage group: 1 088 (85.1%) to a lower stage and 190 (14.9%) to a higher stage. LRR, DM, DFS and OS were significantly different between prognostic stage ⅠA, ⅠB, ⅡA, ⅡB and ⅢA according to 8th edition of the AJCC staging system(P<0.001). Prognostic stage had significantly higher C-indexes and provided better estimation of prognosis compared to stage by 7th edition of the AJCC staging system (P<0.001). Conclusion: The prognostic stage groups of 8th edition AJCC staging system has superior prognostic accuracy compared to 7th edition in T1-2N1M0 breast cancer, and has better clinical therapeutic guidance value.

[Genetic variants of familial hematuria associated genes in three families with hematuria with probands initially diagnosed as IgA nephropathy]

Objective: To examine genetic variants of familial hematuria (FH) associated genes in 3 families with hematuria with probands initially diagnosed with IgA nephropathy (IgAN). Methods: A retrospective analysis was performed on the clinical data, laboratory tests and genetic test results of three children with hematuria and the probands in three families with hematuria. The families were ascertained at the Department of Pediatrics, Fuzhou General Hospital of Nanjing Military Command from August 2014 to May 2018. Results: The proband of Family One, an 8-year-old boy, manifested gross hematuria. His renal biopsy pathology revealed IgAN. His father also manifested hematuria. Genetic testing showed that the proband and his father carried a heterozygous variant of the CFHR5 gene,533A>G (Asn178Ser). The child of Family Two, a 4-year-old girl, manifested hematuria. Her father, the proband of the family, was 36 years old, and manifested hematuria, proteinuria, high-frequency sensorineural deafness and renal insufficiency. He was diagnosed as IgAN according to clinical manifestations, renal pathology and routine immunohistochemistry without renal biopsy electron microscopy, renal tissue type Ⅳ collagen α3, α4, α5 chains immunofluorescence and skin type Ⅳ collagen α5 chain immunofluorescence. Genetic testing showed that the girl carried a heterozygous variant of the COL4A5 gene,566G>T (Gly189Val), and her father carried the hemizygous variant. The child of Family Three, a 7-year-old girl, manifested hematuria and proteinuria. Her mother, the proband of the family, was 34 years old, and manifested hematuria and proteinuria as well. The proband was diagnosed as IgAN by the same method used for Family Two. The girl's grandfather died of uremia at the age of 44. Genetic testing showed that the girl and her mother carried a heterozygous variant 539G>A (Gly180Glu)in COL4A5 gene. Conclusions: The variant of the CFHR5 gene identified in Family One is of uncertain signifance, and the two variants of the COL4A5 gene identified in Families Two and Three are pathogenic. The probands of Families Two and Three are diagnosed as Alport syndrome. The study suggests that clinicians should examine genetic variants of FH associated genes in families with hematuria when the probands were diagnosed as IgAN by their clinical manifestations, renal pathology and routine immunohistochemistry.

Preparation of Micro-Nano Material Composed of Oyster Shell/Fe3O4 Nanoparticles/Humic Acid and Its Application in Selective Removal of Hg(II)

Micro-nano composite material was prepared to adsorb Hg(II) ions via the co-precipitation method. Oyster shell (OS), Fe3O4 nanoparticles, and humic acid (HA) were used as the raw materials. The adhesion of nanoparticles to OS displayed by scanning electron microscopy (SEM), the appearance of the (311) plane of standard Fe3O4 derived from X-ray diffraction (XRD), and the transformation of pore sizes to 50 nm and 20 μm by mercury intrusion porosimetry (MIP) jointly revealed the successful grafting of HA-functionalized Fe3O4 onto the oyster shell surface. The vibrating sample magnetometer (VSM) results showed superparamagnetic properties of the novel adsorbent. The adsorption mechanism was investigated based on X-ray photoelectron spectroscopy (XPS) techniques, which showed the process of physicochemical adsorption while mercury was adsorbed as Hg(II). The effects of pH (3-7), initial solution concentration (2.5-30 mg·L-1), and contact time (0-5 h) on the adsorption of Hg(II) ions were studied in detail. The experimental data were well fitted to the Langmuir isotherm equation (R2 = 0.991) and were shown to follow a pseudo-second-order reaction model (R2 = 0.998). The maximum adsorption capacity of Hg(II) was shown to be 141.57 mg·g-1. In addition, this new adsorbent exhibited excellent selectivity.

[A multicenter study of reference intervals for 15 laboratory parameters in Chinese children]

Objective: To establish comprehensive laboratory reference intervals for Chinese children. Methods: This was a cross-sectional multicenter study. From June 2013 to December 2014, eligible healthy children aged from 6-month to 17-year were enrolled from 20 medical centers with informed consent. They were assessed by physical examination, questionnaire survey and abdominal ultrasound for eligibility. Fasting blood samples were collected and delivered to central laboratory. Measurements of 15 clinical laboratory parameters were performed, including estradiol (E2), testosterone(T), luteinizing hormone(LH), follicle-stimulating hormone(FSH), alanine transaminase(ALT), serum creatinine(Scr), cystatin C, immunoglobulin A(IgA), immunoglobulin G(IgG), immunoglobulin M(IgM), complement (C3, C4), alkaline phosphatase(ALP), uric acid(UA) and creatine kinase(CK). Reference intervals were established according to central 95% confidence intervals for reference population, stratified by age and sex. Results: In total, 2 259 children were enrolled. Finally, 1 648 children were eligible for this study, including 830 boys and 818 girls, at a mean age of 7.4 years. Age- and sex- specific reference intervals have been established for the parameters. Reference intervals of sex hormones increased gradually with age. Concentrations of ALT, cystatin C, ALP and CK were higher in children under 2 years old. Serum levels of sex hormones, creatinine, immunoglobin, CK, ALP and urea increased rapidly in adolescence, with significant sex difference. In addition, reference intervals were variable depending on assay methods. Concentrations of ALT detected by reagents with pyridoxal 5'-phosphate(PLP) were higher than those detected by reagents without PLP. Compared with enzymatic method, Jaffe assay always got higher results of serum creatinine, especially in children younger than 9 years old. Conclusion: This study established age- and sex- specific reference intervals, for 15 clinical laboratory parameters based on defined healthy children.

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, NUP160^R1173× and NUP160^E803K . 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 NUP160^R1173× completely failed to rescue nephrocyte phenotypes, and mutant allele NUP160^E803K 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.

[Evaluation of strain indexes and prognosis of patients with cardiac amyloidosis with preserved LVEF by three-dimensional speckle tracking imaging]

Objective: To evaluate the patients with Cardiac amyloidosis (CA) and Hypertrophic cardiomyopathy (HCM) by using the strain indexes of three-dimensional speckle tracking imaging(3D-STI) technique, and to evaluate the prognosis. Methods: A total of 32 patients with pathologically confirmed cardiac amyloidosis and 34 patients with hypertrophic cardiomyopathy and 16 normal controls were enrolled from the First Affiliated Hospital of Zhejiang University College of Medicine from June, 2013 to January, 2018.The color Doppler echocardiography and three-dimensional speckle tracking echocardiography were used to measure strain indexes of each group, and the Logistic regression equation was used to analyze the index differences.The cut-off values were analyzed using the Receiver Operating Characteristic (ROC), and Kaplan-Meier and Cox were used for survival regression analysis. Results: The globe radial strain (GRS) (16%±7% vs 23%±9%), left ventricular wall peak time difference (PSD) (52 ms±17 ms vs 77 ms±25 ms), Sokolow-Lyon index (20 mm±6 mm vs 34 mm±14 mm) were significantly different between cardiac amyloidosis group and hypertrophic cardiomyopathy group by 3D-STI, which had high sensitivity and specificity by Logistic regression analysis.The area under the ROC curve of GRS was 0.725, PSD was 0.812, Sokolow-Lyon index was 0.832.In addition, the area strain and atrial septal thickness were significant prognostic factors according to survival regression analysis. Conclusions: For the differential diagnosis of cardiac amyloidosis with preserved LVEF, unlike echocardiographic parameters, the 3D-STI strain indicators could be used to differentiate cardiac amyloidosis from hypertrophic cardiomyopathy, reflecting obvious diagnostic advantages.When combined with area strain and atrial septal thickness, 3D-STI strain indicators could be used to predict the survival prognosis, which are important in clinical practice.

[Prognosis and risk factors of 1 791 patients with breast cancer treated with breast-conserving surgery based on real-world data]

Objective: To investigate the overall efficacy of early breast cancer after breast-conserving treatment. To analyze risk factors affecting local regional recurrence (LRR), distant metastasis (DM) and survival. Methods: 1 791 breast cancer patients treated with breast-conserving surgery were retrospectively analyzed. The inclusion criteria were pathologic diagnosis of invasive breast cancer without supraclavicular and internal mammary node metastasis, T1-2N0-3M0, and no neoadjuvant therapy. Univariate analysis of survival was performed by Kaplan-Meier method and log rank test. Cox regression model was used for multivariate analysis. Results: The median follow-up time was 4.2 years. For all patients, the 5-year LRR, DM, disease-free survival(DFS) and overall survival(OS) rates were 3.6%, 4.6%, 93.0% and 97.4%, respectively. The LRR rates of patients with Luminal A, Luminal B1, Luminal B2, HER-2 over-expressed and triple-negative breast cancer were 2.0%, 6.1%, 5.9%, 0 and 10.0%, while the DM rates were 3.2%, 6.7%, 8.3%, 4.8% and 7.3%, respectively. Among the N0 patients, axillary dissection was performed in 689 cases and sentinel lymph node biopsy in 652 cases. The 5-year LRR rates were 3.3% and 3.2% (P=0.859), and the OS rates were 98.2% and 98.3% (P=0.311) respectively, which showed no statistically significant. There were 1 576 patients that underwent postoperative radiotherapy. Postoperative radiotherapy significantly reduced the 5-year LRR compared with surgery alone (2.5% vs 12.9%). The 5-year LRR rates of patients who received conventional fractionated radiotherapy and hypo-fractionated radiotherapy were 2.7% and 3.1%, respectively. But the difference was not statistically significant (P=0.870). Multivariate analysis showed that age, lymphovascular invasion, pathological T staging, postoperative radiotherapy, ER/PR status and endocrine therapy were independent factors of LRR in breast cancer patients (all P<0.05). Histological grade and pathological N staging were independent factors of DM (all P<0.05). The age, lymphovascular invasion, pathological T and N staging, postoperative radiotherapy, ER/PR status and endocrine therapy were independent factors for DFS (all P<0.05). Histological grade, pathological N staging, ER/PR status and endocrine therapy were factors for OS (all P<0.05). Conclusions: With contemporary standard treatment, the recurrence rate of early breast cancer after breast conserving treatment is less than 10%. Node-negative patients after sentinel lymph node biopsy did not need axillary dissection. The overall utilization of radiotherapy after breast conserving surgery is satisfactory. Hypofractionated radiotherapy is as effective as conventional fractionated radiotherapy. Local regional recurrence and distant metastasis have different risk factors.

[Clinical characteristics and prognosis of patients with ipsilateral breast tumor recurrence after breast conservation therapy]

Objective: To analyze the clinical features and prognosis of the ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery. Methods: From 1999 to 2013, 63 women with IBTR after breast conserving surgery were retrospectively reviewed. All patients had adequate information on tumor location both at first presentation and at recurrence, with or without regional recurrence or distant metastasis. The histologic changes between true local recurrence and elsewhere recurrence groups were compared. The local recurrence, the overall survival after IBTR (IBTR-OS), the disease-free survival after IBTR (IBTR-DFS) were also compared. Results: All patients had undergone lumpectomy, including 38 cases with additional axillary lymph node dissection and 13 cases with sentinel lymph node biopsy. There were 11.3% (7/63) cases received neoadjuvant systemic therapy, 68.3% (43/63) had adjuvant radiotherapy, 60.3% (38/63) underwent adjuvant chemotherapy and 47.6% (30/63) received hormonal therapy. Forty-five cases (71.4%) had recurrence in the same quadrant, and 18 cases (28.6%) had elsewhere recurrence. Compared with histology at presentation, 10.3% of the patients (6/58) had different ones at recurrence and 28.9% of patients (13/45) had different molecular subtypes. The conversion rate of estrogen receptor status (33.3% vs 9.5%, P=0.012) and progesterone receptor status (56.3% vs 19.0%, P=0.005) in patients with elsewhere recurrence was significantly higher than that in patients with same quadrant recurrence. Fifty-nine cases had undergone surgery after IBTR, with 48 cases of secondary breast-conserving surgery and 11 cases of salvage mastectomy. The median time to IBTR of same quadrant recurrence and elsewhere recurrence groups were 26 months and 62 months (P=0.012), respectively. There were 84.4% and 44.4% cases who had local recurrence within 5 years after breast conserving surgery, respectively. Of all cases, the overall 5-year IBTR-OS and 5-year IBTR-DFS rates were 79.4% and 60.4%, respectively. There were no significant differences in 5-year IBTR-OS (77.4% vs. 83.6%, P=0.303) or 5-year IBTR-DFS (60.0% vs. 62.8%, P=0.780) between same quadrant recurrence and elsewhere recurrence groups. Univariate analysis showed that pN0-1 (P<0.001), luminal subtype (P=0.026), adjuvant endocrine therapy (P=0.007) at first presentation, recurrent tumor < 3 cm (P=0.036) and having surgery after IBTR(P=0.002) were favorable factors of IBTR-OS. pN0-1 (P<0.001) at first presentation, recurrent tumor stage Ⅰ-Ⅱ (P<0.001) and having surgery after IBTR(P=0.001) were favorable factors of IBTR-DFS. There was no significant difference between second breast-conserving surgery and salvage mastectomy in IBTR-OS and IBTR-DFS (P>0.05). Conclusions: The IBTR after breast conserving surgery mainly occurred at the original quadrant. Second breast-conserving surgery did not affect patient's prognosis. There were significant differences in biological features between the same quadrant recurrence and elsewhere recurrence, requiring different therapeutic strategies in the future.

Knockdown of NUP160 inhibits cell proliferation, induces apoptosis, autophagy and cell migration, and alters the expression and localization of podocyte associated molecules in mouse podocytes

Genetic mutations in dozens of monogenic genes can lead to serious podocyte dysfunction, which is a major cause of steroid-resistant nephrotic syndrome (SRNS). The NUP160 gene is expressed in both human kidney and mouse kidney. However, whether knockdown of NUP160 impairs podocytes has not yet been established. Therefore, we knocked down NUP160 by targeted short hairpin RNA (shRNA) in conditionally immortalized mouse podocytes and observed the effect of NUP160 knockdown on the proliferation, apoptosis, autophagy and cell migration of podocytes. We also investigated the effect of NUP160 knockdown on the expression and localization of podocyte associated molecules, such as nephrin, podocin, CD2AP and α-actinin-4. The knockdown of NUP160 significantly inhibited the proliferation of podocytes by decreasing the expression of both cyclin D1 and CDK4, increasing the expression of p27, and inducing S phase arrest. The knockdown of NUP160 promoted the apoptosis and autophagy of podocytes, and enhanced cell migration. The knockdown of NUP160 decreased the expression of nephrin, podocin and CD2AP in podocytes, and increased the expression of α-actinin-4. The knockdown of NUP160 also altered the subcellular localization of nephrin, podocin and CD2AP in podocytes. These results suggest that the knockdown of NUP160 impairs mouse podocytes, i.e. inhibiting cell proliferation, inducing apoptosis, autophagy and cell migration of mouse podocytes, and altering the expression and localization of podocyte associated molecules, including nephrin, podocin, CD2AP and α-actinin-4.

Rethinking genotype-phenotype correlations in papillorenal syndrome: a case report on an unusual congenital camptodactyly and skeletal deformity with a heterogeneous PAX2 mutation of hexanucleotide duplication

Papillorenal syndrome (PRS), an autosomal dominant inherited condition, is clinically featured by renal hypoplasia and optic nerve dysplasia. Based on current knowledge of genotype-phenotype correlations in PRS, mutations in the Paired box 2 (PAX2) gene have been recognized as a critical pathogenesis of typical renal and optic disease manifestations. However, little information is currently available on the skeletal abnormalities of PRS and the potential contribution of PAX2 mutations. Here, we present a case of a 10-year-old female PRS patient with the typical features of chronic renal failure and severe myopia, but was unexpectedly discovered camptodactyly of her left middle finger which affects the proximal interphalangeal joint. Pathologically, the camptodactyly was further indicated by radiology as a skeletal deformity, demonstrating a decline of bone mineral density and disappearance of joint space. Molecular diagnostics revealed a heterozygous mutation, 220_225dup, in the exon 3 of her PAX2 gene, which is de novo considering the lack of this mutation in her non-consanguineous parents. This mutation leads to duplication of glutamic acid at position 74 and tyrosine at position 75 in PAX2 protein, which may influence the DNA-binding function. Besides, the absence of Spalt like transcription factor 4 (SALL4) mutation excluded the diagnosis of acro-renal-ocular syndrome (AROS), of which clinical characteristics are similar to our patient's. This case unravels a previously unrecognized phenotype of camptodactyly due to a significant skeletal deformity of PRS with a heterogeneous PAX2 mutation of hexanucleotide duplication. This report challenges against the current belief of genotype-phenotype correlations in PRS.

[The role of postmastectomy radiotherapy in clinical T1-3N1M0 breast cancer patients with pathological negative lymph nodes after neoadjuvant chemotherapy and mastectomy]

Objective: To analyze the outcomes of clinical T1-3N1M0 breast cancer patients with pathological negative axillary lymph nodes (ypN0) after neoadjuvant chemotherapy (NAC) and mastectomy, and investigate the role of postmastectomy radiotherapy (PMRT). Methods: A total of 185 patients with clinical T1-3N1M0 breast cancer treated between 1999 and 2013 were retrospectively reviewed. All patients were treated with NAC and mastectomy, and achieved ypN0. Of them, 89 patients received additional PMRT and 96 patients did not. 101 patients had clinical stage Ⅱ disease. 84 patients had clinical stage Ⅲ disease. The rates of locoregional recurrence (LRR), distant metastasis (DM), disease-free survival (DFS), and overall survival (OS) were calculated using the Kaplan-Meier method, and differences were compared using the log-rank test. Univariate analysis was used to interpret the impact of clinical features and treatment on patients' outcome. Results: The 5-year rates of LRR, DM, DFS, and OS for all patients were 4.5%, 10.4%, 86.6%, and 97.1%, respectively. For patients with and without PMRT, the 5-year LRR rates were 1.1% and 7.5% (P=0.071), the 5-year DM rates were 5.1% and 15.0% (P=0.023), the 5-year DFS rates were 95.0% and 79.0% (P=0.008), and the 5-year OS rates were 100.0% and 94.5% (P=0.089) respectively. In univariate analysis, lymph-vascular space invasion (LVSI) was poor prognostic factor of LRR (P=0.001), < 40 years old and lack of PMRT was a poor prognostic factor for DM (P<0.05), lack of PMRT was a poor prognostic factor for DFS (P=0.008), primary lesion residual and mild-moderate pathological response to NAC were poor prognostic factors for OS (P<0.05). In the subgroup of Stage Ⅲ disease, for patients with and without PMRT, the 5-year LRR rates were 1.9% and 14.4% (P=0.041), the 5-year DFS rates were 91.9% and 67.4% (P=0.022), respectively. In the subgroup of Stage Ⅱ disease, for patients with and without PMRT, the 5-year DM rates were 0 and 11.5% (P=0.044), the 5-year DFS rates were 100.0% and 84.9% (P=0.023), respectively. Conclusions: The LRR rate of clinical T1-3N1M0 breast cancer patients who achieved ypN0 after NAC and mastectomy was low. PMRT decreased the DM rate and increased DFS rate in all patients, and significantly decreased the LRR rate in Stage Ⅲ disease. PMRT should be considered for patients with Stage Ⅲ disease, and further research is warranted to investigate the benefit of PMRT for Stage Ⅱ disease.

[Analysis of variants in complement genes in Han Chinese children with atypical hemolytic uremic syndrome]

Objective: To investigate the prevalence and characteristics of pathogenic variants in complement genes in Han Chinese children with atypical hemolytic uremic syndrome (aHUS). Method: Eleven Han Chinese children with aHUS, including 9 boys and 2 girls aged between 1 year and 4 months and 13 years, were investigated in Department of Pediatrics, Fuzhou General Hospital, from November 1998 to February 2014. Analysis of variants of all the exons of 10 complement genes (CFH, MCP, CFI, C3, CFB, CFHR1, CFHR2, CFHR3, CFHR4 and CFHR5), including 25 bases from 3' end and 25 bases from 5' end, was performed in the 11 cases by targeted sequence capture and next generation sequencing. Significant variants detected by next generation sequencing were confirmed by Sanger sequencing. To understand pathogenicity of variants found in the captured genes, we investigated genetic conservation by multiple protein sequence alignment among different species, and analyzed whether the variants were located in protein domains or not, and investigated functional significance by functional computational prediction methods. Result: Twenty-seven percent of Han Chinese children with aHUS carried pathogenic variants in the 10 complement genes. Pathogenic variant CFB 221G>A (R74H) was detected in Patient 3 and Patient 9, which was not found in parents of Patient 3' , and was found in healthy father of patient 9. Pathogenic variant CFHR5 242C>T (P81L) was found in Patient 2, and was found in healthy father of patient 2. However, no pathogenic variants in genes CFH, MCP, CFI, C3, CFHR1, CFHR2, CFHR3 and CFHR4 were identified. Conclusion: Pathogenic variants in the 10 complement genes were identified in 3/11 of Han Chinese children with aHUS in our study and CFB was the most frequently mutated gene.

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.

[Prognostic differences of phenotypes in pT1-2N0 invasive breast cancer: a large cohort study with cluster analysis]

OBJECTIVE

To find phenotypic subgroups of patients with pT1-2N0 invasive breast cancer by means of cluster analysis and estimate the prognosis and clinicopathological features of these subgroups.

METHODS

From 1999 to 2013, 4979 patients with pT1-2N0 invasive breast cancer were recruited for hierarchical clustering analysis. Age (≤40, 41-70, 70+ years), size of primary tumor, pathological type, grade of differentiation, microvascular invasion, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) were chosen as distance metric between patients. Hierarchical cluster analysis was performed using Ward's method. Cophenetic correlation coefficient (CPCC) and Spearman correlation coefficient were used to validate clustering structures.

RESULTS

The CPCC was 0.603. The Spearman correlation coefficient was 0.617 (P<0.001), which indicated a good fit of hierarchy to the data. A twelve-cluster model seemed to best illustrate our patient cohort. Patients in cluster 5, 9 and 12 had best prognosis and were characterized by age >40 years, smaller primary tumor, lower histologic grade, positive ER and PR status, and mainly negative HER-2. Patients in the cluster 1 and 11 had the worst prognosis, The cluster 1 was characterized by a larger tumor, higher grade and negative ER and PR status, while the cluster 11 was characterized by positive microvascular invasion. Patients in other 7 clusters had a moderate prognosis, and patients in each cluster had distinctive clinicopathological features and recurrent patterns.

CONCLUSIONS

This study identified distinctive clinicopathologic phenotypes in a large cohort of patients with pT1-2N0 breast cancer through hierarchical clustering and revealed different prognosis. This integrative model may help physicians to make more personalized decisions regarding adjuvant therapy.

A new perspective on the IIIC staging in Chinese patients with primary breast cancer: Single-center experiences

PURPOSE

The purpose of this retrospective study was to investigate whether Stage IIIC (TanyN3M0) breast cancer can be classified further into subgroups with different prognosis.

MATERIALS AND METHODS

One hundred and thirty-two patients with Stage IIIC breast cancer at Tianjin Medical University Cancer Institute and Hospital were analyzed. The disease-free survival (DFS) and overall survival (OS) were calculated by Kaplan-Meier method for lymph node ratio (LNR) and the number of positive lymph node (PLN). The receiver operating characteristic curve analysis was performed to determine the optimal cut-off value of the LNR and PLN. The univariate and multivariate analysis were applied to identify the prognostic factors.

RESULTS

The results showed that the optimal cut-off value of LNR value was 0.65, and the optimal cut-off value of PLN was 15. The Kaplan-Meier survival analysis showed the higher value of LNR or PLN was correlated with shortened DFS (P = 0.002, P = 0.008, respectively) and OS (P < 0.001, P = 0.001, respectively). In multivariate survival analysis, the value of LNR and PLN were still remained as independent prognostic factors for DFS (P = 0.014, P = 0.013, respectively) and OS (P = 0.004, P = 0.002, respectively).

CONCLUSION

These results suggest that the value of LNR or PLN could be used as a new significant prognostic biomarker for Stage IIIC breast cancer patients. Stage IIIC breast cancer patients with lower value of LNR or PLN may be down staged.

Analysis of the association between polymorphisms in the vitamin D receptor (VDR) gene and dental caries in a Chinese population

Environmental influences on the development and progression of dental caries are well known; however, there is little evidence of a genetic component imparting susceptibility to dental caries. The aim of this study was to investigate the relationship between a single nucleotide polymorphism in the vitamin D receptor TaqI locus and dental caries susceptibility in a Chinese population. This case-control study was conducted with a case group (264 patients with dental caries from northwestern China) and a control group (219 individuals without dental caries or systemic disease from the same area). DNA was extracted from the peripheral venous blood of the study participants; the distribution of TaqI locus genotypes and allele frequencies was determined via polymerase chain reaction-restriction fragment length polymorphism. The data obtained were statistically analyzed using the Hardy-Weinberg equilibrium and Chi-square test. The frequency of the Tt genotype in the case group (14.0%) was significantly higher than that in the control group (4.3%), as determined using the genotype TT as the reference. The risk of dental caries was increased 3.8-fold in individuals with the heterozygous Tt genotype compared to that in the individuals with the TT genotype. The proportion of the 't' allele in the case group (7.0%) and the control group (2.1%) was observed to be significantly different [P = 0.0003; OR = 3.592, confidence interval 95% (1.790-7.208)]. Our results therefore suggested that the allele 't' might be a genetic factor determining dental caries susceptibility in individuals from the northwest of China.

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.

Plasma exchange parameter selection and safety observation of children with severe ricinism

The aim of this study was to investigate the selection of plasma exchange (PE) parameters and the safety of children with severe ricinism. The PE parameters and heparin dosage in 7 children with severe ricinism were recorded, and changes in the patients' vital signs and coagulation function were monitored before and after PE. All patients successfully completed PE. The speed of blood flow was 50-80 mL/min, speed of exchange flow was 600-800 mL/h, and isolating rate of blood plasma was 12.5-19.05%. Transmembrane pressure was stable at approximately 100 mmHg, and venous pressure was stable at approximately 95 mmHg. The first dose of heparin was 0.39 ± 0.04 mg/kg, and the maintaining heparin dose was 0.40 ± 0.05 to 0.22 ± 0.03 mg·kg(-1)·h(-1). During the PE process, mean arterial pressure, heart rate, respiratory rate, and pulse oxygen saturation were steady. After PE, the activated partial thromboplastin time and thrombin time prolonged to 2-3 times greater than that before PE. However, no bleeding tendency was seen. For children with severe ricinism, the choice of PE to eliminate the toxin from blood, tissues, and organs was safe and effective.

Mutational analysis of podocyte genes in children with sporadic steroid-resistant nephrotic syndrome

Recent studies have demonstrated that mutations in 4 podocyte genes, NPHS1, NPHS2, CD2AP, and WT1, are associated with the pathogenesis of steroid-resistant nephrotic syndrome (SRNS). Systematic investigation of all 4 genes for sporadic SRNS in China has not been performed. We examined 10 Chinese children with sporadic SRNS who showed no response to immunosuppressive agents and 20 SRNS controls who exhibited a response to prolonged steroid or immunosuppressive treatment and achieved complete remission. We analyzed mutations in the 4 podocyte genes, NPHS1, NPHS2, CD2AP, and WT1. Mutational analysis was performed using polymerase chain reaction and direct sequencing. Of the 10 SRNS children who showed no response to immunosuppressive agents, the compound heterozygous NPHS1 mutations 2677A>G (T893A) and *142T>C were identified in 1 patient, while a heterozygous mutation in WT1, 1180C>T (R394W), was found in another patient. Of the 20 SRNS children showing complete remission who responded to prolonged steroid therapy or immunosuppressive agents, 4 heterozygous NPHS1 mutations, 928G>A, IVS8+30C>T, IVS21+14G>A, and IVS25-23C>T, were identified in 4 patients and a heterozygous CD2AP mutation, IVS7-135G>A, was identified in 1 patient. Our results indicate the necessity of genetic examination for mutations in podocyte genes in Chinese SRNS children who show no response to immunosuppressive agents.

[Mutational analysis of MYO1E in children with sporadic steroid-resistant nephrotic syndrome in Chinese Han ethnic group]

OBJECTIVE

Previous studies have demonstrated that two homozygous missense MYO1E mutations are associated with childhood autosomal recessive focal segmental glomerulosclerosis in steroid-resistant nephrotic syndrome (SRNS) families from Italy and Turkey. Non-disease-causing heterozygous MYO1E variants were also found in other SRNS patient cohorts. However, the role of MYO1E mutations in Chinese sporadic SRNS has not been established.

METHOD

Peripheral blood samples were collected for genetic analysis from 54 children with sporadic SRNS in Chinese Han ethnic group and a normal control group of 59 healthy adult volunteers. None of the patients carried mutations in NPHS2 or WT1. Genomic DNA was extracted from peripheral blood leukocytes. Twenty-eight exons and exon-intron boundaries of the MYO1E gene were amplified by polymerase chain reaction. Mutational analysis was performed by direct DNA sequencing and restriction endonuclease digestion.

RESULT

Fifty-one variants in the MYO1E gene were identified in 54 children with sporadic SRNS. Among them, 10 MYO1E mutations of IVS1-11T>C, IVS2-86T>A, 279T>C (D93D), IVS6-181G>A, 718C>T (L240F), 1678A>G (T560A), IVS16-35A>G, IVS18+48T>A, IVS19+38G>A and IVS25+13C>T were detected in 11 patients, whereas they were absent in the 59 normal Chinese controls. Forty-one variants in MYO1E were identified and all of them were published in single nucleotide polymorphism database from national center for biotechnology information. Furthermore, all the 10 MYO1E mutations were in heterozygous states.

CONCLUSION

MYO1E mutations are not a major cause of Chinese children with sporadic SRNS in the study.

Wilms' tumor suppressor gene mutations in girls with sporadic isolated steroid-resistant nephrotic syndrome

Mutations in the Wilms' tumor suppressor gene (WT1) can lead to syndromic forms of steroid-resistant nephrotic syndrome (SRNS) such as Denys-Drash or Frasier syndrome and can cause isolated SRNS. A mutation within WT1 is a frequent cause of sporadic isolated SRNS in girls. In a worldwide cohort of girls, the rate of occurrence was 10.8%. Previous reports have indicated that in Chinese girls, the detection rate of WT1 mutations is 16.7% for early onset isolated nephrotic syndrome. The detection rate of WT1 mutations in Chinese girls with sporadic isolated SRNS is unknown. We examined WT1 mutations in 14 Chinese girls with sporadic isolated SRNS using polymerase chain reaction and direct sequencing and studied a control group of 38 boys with sporadic isolated SRNS. We identified a WT1 mutation in 1 of 14 (7.1% detection rate) Chinese girls with sporadic isolated SRNS. No mutations occurred in WT1 in the remaining 13 girls or the control group. Our investigation supports the necessity of genetic examination for mutations in WT1 in girls with sporadic isolated SRNS.