Mutations in the NUP93, NUP107 and NUP160 genes cause steroid-resistant nephrotic syndrome in Chinese children.

BACKGROUND: The variants of nucleoporins are extremely rare in hereditary steroid-resistant nephrotic syndrome (SRNS). Most of the patients carrying such variants progress to end stage kidney disease (ESKD) in their childhood. More clinical and genetic data from these patients are needed to characterize their genotype-phenotype relationships and elucidate the role of nucleoporins in SRNS. METHODS: Four patients of SRNS carrying biallelic variants in the NUP93, NUP107 and NUP160 genes were presented. The clinical and molecular genetic characteristics of these patients were summarized, and relevant literature was reviewed. RESULTS: All four patients in this study were female and initially presented with SRNS. The median age at the onset of the disease was 5.08 years, ranging from 1 to 10.5 years. Among the four patients, three progressed to ESKD at a median age of 7 years, ranging from 1.5 to 10.5 years, while one patient reached stage 3 chronic kidney disease (CKD3). Kidney biopsies revealed focal segmental glomerulosclerosis in three patients. Biallelic variants were detected in NUP93 in one patient, NUP107 in two patients, as well as NUP160 in one patient respectively. Among these variants, five yielded single amino acid substitutions, one led to nonsense mutation causing premature termination of NUP107 translation, one caused a single nucleotide deletion resulting in frameshift and truncation of NUP107. Furthermore, one splicing donor mutation was observed in NUP160. None of these variants had been reported previously. CONCLUSION: This report indicates that biallelic variants in NUP93, NUP107 and NUP160 can cause severe early-onset SRNS, which rapidly progresses to ESKD. Moreover, these findings expand the spectrum of phenotypes and genotypes and highlight the importance of next-generation sequencing in elucidating the molecular basis of SRNS and allowing rational treatment for affected individuals.

Clinical, histological and molecular characteristics of Alport syndrome in Chinese children.

BACKGROUND: Alport syndrome is caused by COL4A3, COL4A4, or COL4A5 gene mutations. The present study aims to compare the clinicopathological features, gene mutations, and outcome of Chinese children with different forms of Alport syndrome. METHODS: One hundred twenty-eight children from 126 families diagnosed with Alport syndrome through pathological and genetic examination between 2003 and 2021 were included in this single-center retrospective study. The laboratory and clinicopathological features of the patients with different inheritance patterns were analyzed. The patients were followed-up for disease progression and phenotype-genotype correlation. RESULTS: Of the 126 Alport syndrome families, X-linked forms accounted for 77.0%, autosomal recessive for 11.9%, autosomal dominant for 7.1%, and digenic for 4.0%. Among the patients, 59.4% were males and 40.6% were females. Altogether, 114 different mutations were identified in 101 patients from 99 families by whole-exome sequencing, of which 68 have not been previously reported. The most prevalent type of mutation was glycine substitution, which was identified in 52.1%, 36.7%, and 60% of the patients with X-linked Alport syndrome, autosomal recessive and autosomal dominant Alport syndrome, respectively. At the end of a median follow up of 3.3 (1.8-6.3) years, Kaplan-Meier curves showed kidney survival was significantly lower in autosomal recessive compared to X-linked Alport syndrome (P = 0.004). Pediatric patients with Alport syndrome seldom presented extrarenal involvement. CONCLUSIONS: X-linked Alport syndrome is the most frequent form found in this cohort. Progression was more rapid in autosmal recessive than in X-linked Alport syndrome.

Effectiveness of Huai Qi Huang Granules on Juvenile Collagen-induced Arthritis and Its Influence on Pyroptosis Pathway in Synovial Tissue.

Huai Qi Huang (HQH) exerts great effects in clinic, such as anti-inflammation, immune-regulation, anti-cancer, and so on. However, the mechanism by which HQH protects juvenile idiopathic arthritis (JIA) is obscure. Thus, we explored deeply the protective mechanisms in juvenile collagen-induced arthritis (CIA) rat model. Pyroptosis is Gasdermin D (GSDMD)-dependent programmed cell death, involved in many diseases, such as sepsis. We investigated whether GSDMD-induced pyroptosis take part in mechanisms of juvenile CIA arthritis. Juvenile Wistar rats (3-4 weeks) were injected intradermally with fully emulsified bovine type II collagen and complete Freund's adjuvant to establish CIA rat models. Later, the CIA rats received oral administration of HQH (4.16 g/kg) once a day from the day 21 of modeling, with the treatment lasting for 28 days. Varieties of indicators were measured for evaluation of anti-inflammation effect of HQH, including hind paw swelling, arthritis scores, micro CT, and histopathological changes and the level of pro-inflammatory cytokines in the serum, including tumor necrosis factor alpha (TNF-±) and interleukin-18 (IL-18). The expression of GSDMD and caspase-1 in the joint synovial tissues was detected. The results demonstrated that the expression of the pyroptotic protein GSDMD and its upstream caspase-1 was significantly increased in the synovial tissues of CIA rats. The treatment of HQH ameliorated the symptoms in CIA rats, reduced levels of pro-inflammatory cytokines and hind paw swelling, down-regulated the expression of GDSMD and caspase-1. GSDMD-induced pyroptosis participated in the pathogenesis of CIA rats. The study supported that HQH can effectively improve joints inflammation of juvenile collagen-induced arthritis rats by inhibiting pyroptosis pathway in the joint synovial tissues.