Mutations of RNF213 are responsible for sporadic cerebral cavernous malformation and lead to a mulberry-like cluster in zebrafish.

Although familial forms of cerebral cavernous malformation are mainly attributed to three CCM genes (KRIT1, CCM2 and PDCD10), no mutation is identified in sporadic cerebral cavernous malformation cases with a unique lesion, indicating additional genes for sporadic cerebral cavernous malformation. To screen the candidate genes, we conducted whole exome sequencing in 31 sporadic cerebral cavernous malformation patients and 32 healthy controls, and identified 5 affected individuals carrying 6 heterozygous deleterious mutations in RNF213 but no RNF213 mutation in healthy individuals. To further confirm RNF213 was associated with cerebral cavernous malformation, we generated rnf213a homozygous knockout zebrafish and found mutation of rnf213a in zebrafish led to a mulberry-like cluster of disordered-flow vascular channels which was reminiscent of human cerebral cavernous malformation. In addition, we revealed kbtbd7 and anxa6 were significantly downregulated due to rnf213a mutation through transcriptomic sequencing and RT-qPCR analysis. Based on the mulberry-like phenotype partly rescued by mRNA of kbtbd7 as well as anxa6, we suggested that rnf213a promoted mulberry-like cluster via downregulation of kbtbd7 and anxa6. Altogether, we firstly demonstrate RNF213is a novel candidate gene for sporadic cerebral cavernous malformation and the mutation of rnf213a is responsible for the mulberry-like cluster in zebrafish.

Expression profile of BAFF in peripheral blood from patients of IgA nephropathy: Correlation with clinical features and Streptococcus pyogenes infection.

B cells are critically important for the pathogenesis of IgA nephropathy (IgAN). The present study aimed to investigate the abundance of B cell activating factor (BAFF), which belongs to the tumor necrosis factor superfamily, in the peripheral blood of patients with IgAN. The different forms of BAFF in peripheral blood and its association with clinical features and immunological factors were analyzed. mRNA levels of BAFF and other associated genes in the peripheral blood mononuclear cells (PBMCs) of patients with IgAN and controls were analyzed by quantitative polymerase chain reaction. Cellular BAFF proteins in PBMCs and plasma soluble BAFF proteins were measured by western blot analysis and ELISA, respectively. PBMCs from patients were stimulated with Streptococcus pyogenes (S. pyogenes) ex vivo for the BAFF secretion assay. The data demonstrated that, although mRNA levels of BAFF in PBMC were not significantly increased in patients with IgAN, they were positively associated with those of a proliferation inducing ligand (APRIL), Toll­like receptor (TLR)2, TLR4 and TLR7. The cellular BAFF protein in PBMCs was not upregulated. Plasma BAFF protein levels in patients with IgAN (n=76) were significantly decreased compared with controls. However, plasma BAFF levels were positively associated with serum creatinine, proteinuria, uric acid and group A Streptococcus infection index in patients with IgAN. In patients with IgAN, plasma BAFF concentrations were markedly higher in those with more severe renal tubular atrophy/interstitial fibrosis and global glomerulosclerosis. Furthermore, BAFF production in PBMCs of patients with IgAN was increased following S. pyogenes stimulation ex vivo. In conclusion, plasma BAFF levels in patients with IgAN were associated with renal function and disease activity. S. pyogenes infection was closely associated with BAFF production in patients with IgAN.

[Recurrence of Cerebral Infarction Associated Aspirin Resistance or Chinese Medical Constitutions: a Correlation Study].

OBJECTIVE: To explore the correlation between the recurrence of cerebral infarction and aspirin resistance (AR)/Chinese medical (CM) constitutions. METHODS: Totally 413 cerebral infarction patients took Aspirin Enteric-coated Tablet (100 mg per day) while receiving routine therapy, 5 days at least in a week. They were followed-up for 12 months. Aspirin sensitivity (AS) was determined using turbidimetry. CM constitutions among patients with different AS were compared. Ratios of AR patients and AS patients of different CM constitutions in cerebral infarction recurrent patients were compared. Platelet membrane glycoproteins (GP) II b HPA-3 gene polymorphism was detected by polymerase chain reaction (PCR) method. Correlation between recurrence of cerebral infarction and AR, bb genotypes, CM constitutions times AS were analyzed by Logistic regression. RESULTS: Totally 11 patients dropped out, 101 (25.12%)with recurrent cerebral infarction and 301 (74.88%) without recurrent cerebral infarction. There were 152 (37.81%) AR patients and 250 (62.19%) AS patients. AR accounted for 26.6% (80/ 301) and AS accounted for 73.4% (221/301) in non-recurrent cerebral infarction patients. AR accounted for 71.3% (72/101) and AS accounted for 28.7% (29/101) in recurrent cerebral infarction patients. There was statistical difference in AR and AS ratios (χ2 = 64.287, P = 0.000). The proportion of yin deficiency constitution (YDC) was the largest [28.3% (43/152)] in AR patients. The proportion of blood stasis constitution (BSC) was the largest [23.6% (59/250)] in AS patients. There was statistical difference in CM constitutions between AR patients and AS patients (χ2 = 21.574, P < 0.01). The former 4 recurrent rates occurred in AR patients of YDC, BSC, damp-phlegm constitution (DPC), qi deficiency constitution (QDC). YDC occupied the first place [22.4% (34/152)]. The former 4 recurrent rates occurred in AS patients of BSC, QDC, DPC, damp-heat constitution (DHC). BSC occupied the first place [3.2% (2/250)]. Compared with non-recurrent cerebral infarction patients and AS patients, bb gene occurred most often, but aa gene and ab gene occurred obviously lesser in non-recurrent cerebral infarction patients and AR patients (χ2 = 20.171, χ2 = 55.139, P < 0.01). AR and bb gene were positively correlated with recurrent cerebral infarction (OR = 18.423, P = 0.000; OR = 1.304, P = 0.028). Body constitutions interacted with AS (OR = 0.707, P = 0.000). CONCLUSIONS: Recurrent cerebral infarction was closely related to AR and constitutional types. The recurrence rate was higher in AR patients of YDC. GP I b HPA-3 bb genotype might be a risk factor for AR and recurrent cerebral infarction.

Nickel trafficking system responsible for urease maturation in Helicobacter pylori.

Helicobacter pylori (H. pylori) is a common human pathogen responsible for various gastric diseases. This bacterium relies on the production of urease and hydrogenase to inhabit the acidic environment of the stomach. Nickel is an essential cofactor for urease and hydrogenase. H. pylori has to uptake sufficient nickel ions for the maturation of urease, and on the other way, to prevent the toxic effects of excessive nickel ions. Therefore, H. pylori has to strike a delicate balance between the import of nickel ions, its efficient intracellular storage, and delivery to nickel-dependent metalloenzymes when required. The assembly and maturation of the urease enzyme is a complex and timely ordered process, requiring various regulatory, uptake, chaperone and accessory proteins. In this review, we focus on several nickel trafficking proteins involved in urease maturation: NikR, NixA, HypAB, UreEFGH, HspA, Hpn and Hpnl. The work will deepen our understanding of how this pathogenic bacterium adapts to severe habitant environments in the host.

Histidine-rich protein Hpn from Helicobacter pylori forms amyloid-like fibrils in vitro and inhibits the proliferation of gastric epithelial AGS cells.

Helicobacter pylori causes various gastric diseases, such as gastritis, peptic ulcerations, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Hpn is a histidine-rich protein abundant in this bacterium and forms oligomers in physiologically relevant conditions. In this present study, Hpn oligomers were found to develop amyloid-like fibrils as confirmed by negative stain transition electron microscopy, thioflavin T and Congo red binding assays. The amyloid-like fibrils of Hpn inhibit the proliferation of gastric epithelial AGS cells through cell cycle arrest in the G2/M phase, which may be closely related to the disruption of mitochondrial bioenergetics as reflected by the significant depletion of intracellular ATP levels and the mitochondrial membrane potential. The collective data presented here shed some light on the pathologic mechanisms of H. pylori infections.