Recognition and characterization of TGF-β receptor interacting protein 1 (TRIP-1) containing WD40 repeats from Clonorchis sinensis by bioinformatics, cloning, and expression in Escherichia coli

Identification of a novel SUOX pathogenic variants as the cause of isolated sulfite oxidase deficiency in a Chinese pedigree

BACKGROUND

Isolated sulfite oxidase deficiency (ISOD) is a life-threatening rare autosomal recessive disorder caused by pathogenic variants in SUOX (OMIM 606887) gene. The aim of our study was to establish a comprehensive genetic diagnosis strategy for the pathogenicity analysis of the SUOX gene within a limited time and to lay the foundation for precise genetic counseling, prenatal diagnosis, and preimplantation genetic diagnosis.

METHODS

Two offspring from one set of parents were studied. Next-generation sequencing (NGS) was used to screen for disease-causing gene variants in a family with ISOD. Then, Sanger sequencing was performed to verify the presence of candidate variants. Sulfite, homocysteine and uric acid levels were detected in the patients. According to the ACMG/AMP guidelines, the pathogenicity level of novel variants was annotated.

RESULTS

The nonsense pathogenic variant (c.1200C > G (p.Y400*)) and a duplication (c.1549_1574dup (p.I525 Mfs*102)) were found in the SUOX gene in the proband. The nonsense mutation (c.1200C > G (p.Y400*), pathogenic, isolated sulfite oxidase deficiency, autosomal recessive) has been reported as pathogenic and the duplication (c.1549_1574dup (p.I525 Mfs*102), pathogenic, isolated sulfite oxidase deficiency, autosomal recessive) was novel, which was classified as pathogenic according to the ACMG/AMP Standards and Guidelines.

CONCLUSION

We established the pathogenicity assessment in ISOD patients based on ACMG/AMP Standards and Guidelines and this is the first ISOD patient reported in mainland China. We also discovered that ISOD is caused by SUOX gene duplication mutation, which enriches the spectrum of SUOX pathogenic variants.

Cytokine Production in Cholangiocarcinoma Cells in Response to Clonorchis sinensis Excretory-Secretory Products and Their Putative Protein Components

Clonorchis sinensis is a carcinogenic human liver fluke that promotes hepatic inflammatory environments via direct contact or through their excretory-secretory products (ESPs), subsequently leading to cholangitis, periductal fibrosis, liver cirrhosis, and even cholangiocarcinoma (CCA). This study was conducted to examine the host inflammatory responses to C. sinensis ESPs and their putative protein components selected from C. sinensis expressed sequenced tag (EST) pool databases, including TGF-β receptor interacting protein 1(CsTRIP1), legumain (CsLeg), and growth factor binding protein 2 (CsGrb2). Treatment of CCA cells (HuCCT1) with the ESPs or bacterial recombinant C. sinensis proteins differentially promoted the secretion of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) as well as anti-inflammatory cytokines (IL-10, TGF-β1, and TGF-β2) in a time-dependent manner. In particular, recombinant C. sinensis protein treatment resulted in increase (at maximum) of ~7-fold in TGF-β1, ~30-fold in TGF-β2, and ~3-fold in TNF-α compared with the increase produced by ESPs, indicating that CsTrip1, CsLeg, and CsGrb2 function as strong inducers for secretion of these cytokines in host cells. These results suggest that C. sinensis ESPs contribute to the immunopathological response in host cells, leading to clonorchiasis-associated hepatobiliary abnormalities of greater severity.

Two novel mutations in the PPIB gene cause a rare pedigree of osteogenesis imperfecta type IX

BACKGROUND

Osteogenesis imperfecta (OI) is a rare genetic skeletal disorder characterized by increased bone fragility and vulnerability to fractures. PPIB is identified as a candidate gene for OI-IX, here we detect two pathogenic mutations in PPIB and analyze the genotype-phenotype correlation in a Chinese family with OI.

METHODS

Next-generation sequencing (NGS) was used to screen the whole exome of the parents of proband. Screening of variation frequency, evolutionary conservation comparisons, pathogenicity evaluation, and protein structure prediction were conducted to assess the pathogenicity of the novel mutations. Sanger sequencing was used to confirm the candidate variants. RTQ-PCR was used to analyze the PPIB gene expression.

RESULTS

All mutant genes screened out by NGS were excluded except PPIB. Two novel heterozygous PPIB mutations (father, c.25A>G; mother, c.509G>A) were identified in relation to osteogenesis imperfecta type IX. Both mutations were predicted to be pathogenic by bioinformatics analysis and RTQ-PCR analysis revealed downregulated PPIB expression in the two carriers.

CONCLUSION

We report a rare pedigree with an autosomal recessive osteogenesis imperfecta type IX (OI-IX) caused by two novel PPIB mutations identified for the first time in China. The current study expands our knowledge of PPIB mutations and their associated phenotypes, and provides new information on the genetic defects associated with this disease for clinical diagnosis.

Receptor for activated C kinase ortholog of second-generation merozoite in Eimeria tenella: clone, characterization, and diclazuril-induced mRNA expression

The receptor for activated C kinase (RACK) cDNA of second-generation merozoites of Eimeria tenella was cloned using reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends, compared with other species, and then successfully expressed using the pET-28a vector in Escherichia coli BL21 (DE3) (EtRACK). Nucleotide sequence analysis revealed that the full length of the cloned cDNA (1,264 bp) encompassed a 957-bp open reading frame encoding a polypeptide of 318 residues with an estimated molecular mass of 34.94 kDa and a theoretical isoelectric point of 5.97. Molecular analysis of EtRACK reveals the presence of seven WD40 repeat motifs. EtRACK localizes to the cytoplasm and nucleus in second-generation merozoites of E. tenella. The cDNA sequence has been submitted to the GenBank Database with accession number JQ292804. EtRACK shared 98% homology with the published sequence of a RACK protein from Toxoplasma gondii at the amino acid level (GenBank XP_002370996.1). Recombinant protein expression was induced using 1 mM of isopropyl β-D-1-thiogalactopyranoside in vitro at 30 °C. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed that the 39.79-kDa fusion protein existed in unsolvable form. Quantitative real-time PCR analysis showed that compared with the control group, the level of EtRACK mRNA expression in the treatment group was downregulated by 81.3% by diclazuril treatment. The high similarity of EtRACK to previously described RACKs of other organisms, as well as its downregulated expression in second-generation merozoites induced by diclazuril, suggests that it could play a key role in the signaling event that precedes protein secretion and parasite invasion. Moreover, the downregulation of EtRACK mRNA expression also enriches studies on the mechanism of action of diclazuril on E. tenella.

Clonorchis sinensis and clonorchiasis, an update

Clonorchis sinensis is the most common human liver fluke in East Asia. Several studies proved its carcinogenesis in humans and it was reclassified as a group 1 biological carcinogen in 2009. It is still actively transmitted in endemic areas of Korea, China, Russia, and Vietnam. Currently it is estimated that more than 200 million people are at risk of infection, 15-20 million people are infected and 1.5-2 million show symptoms or complications. Several molecules and genes of the fluke have been identified and characterized. Studies on its oncogenesis and omics-based findings have been especially encouraging. Diagnosis of its infection depends mainly on detection of eggs in feces but other methods have been developed. ELISA using crude extract antigen is now popular for its diagnosis. Diagnosis by detecting DNAs from eggs in feces has been developed using PCR, real-time PCR, and LAMP, which have been found sensitive and specific. Imaging diagnosis has been studied in depth and is widely used. Any evidence of clonorchiasis, such as eggs, DNAs, or images, may lead to recommendations of chemotherapy in endemic areas. Praziquantel is the major chemotherapeutic agent for clonorchiasis and recently tribendimidine was found effective and is now under investigation as a promising chemotherapeutic alternative. Sustainable control programs which include mass chemotherapy with praziquantel and education for prevention of re-infection may reduce its morbidity and eliminate its infections in endemic areas.