Molecular and expression characterization of a nanos1 homologue in Chinese sturgeon, Acipenser sinensis

The nanos gene family was essential for germ line development in diverse organisms. In the present study, the full-length cDNA of a nanos1 homologue in A. sinensis, Asnanos1, was isolated and characterized. The cDNA sequence of Asnanos1 was 1489 base pairs (bp) in length and encoded a peptide of 228 amino acid residues. Multiple sequence alignment showed that the zinc-finger motifs of Nanos1 were highly conserved in vertebrates. By RT-PCR analysis, Asnanos1 mRNAs were ubiquitously detected in all tissues examined except for the fat, including liver, spleen, heart, ovary, kidney, muscle, intestines, pituitary, hypothalamus, telencephalon, midbrain, cerebellum, and medulla oblongata. Moreover, a specific polyclonal antibody was prepared from the in vitro expressed partial AsNanos1 protein. Western blot analysis revealed that the tissue expression pattern of AsNanos1 was not completely coincided with that of its mRNAs, which was not found in fat, muscle and intestines. Additionally, by immunofluoresence localization, it was observed that AsNanos1 protein was in the cytoplasm of primary oocytes and spermatocytes. The presented results indicated that the expression pattern of Asnanos1 was differential conservation and divergence among diverse species.     

A novel heterozygous mutation of the AIRE gene in a patient with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED)

Background

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) is an autosomal recessive disease due to mutations of the autoimmune regulator (AIRE) gene. Typical manifestations include candidiasis, Addison's disease, and hypoparathyroidism. Type 1 diabetes, alopecia, vitiligo, ectodermal dystrophy, celiac disease and other intestinal dysfunctions, chronic atrophic gastritis, chronic active hepatitis, autoimmune thyroid disorders, pernicious anemia and premature ovarian failure are other rare associated diseases although other conditions have been associated with APECED.

Case presentation

What follows is the clinical, endocrinological and molecular data of a female APECED patient coming from Lithuania. The patient was affected by chronic mucocutaneous candidiasis, hypoparathyroidism and pre-clinical Addison's disease. Using direct sequencing of all the 14 exons of the AIRE gene in the patient's DNA, we identified in exon 6 the known mutation c.769 C>T (p.Arg257X) in compound heterozygosity with the newly discovered mutation c.1214delC (p.Pro405fs) in exon 10. The novel mutation results in a frameshift that is predicted to alter the sequence of the protein starting from amino acid 405 as well as to cause its premature truncation, therefore a non-functional Aire protein.

Conclusions

A novel mutation has been described in a patient with APECED with classical clinical components, found in compound heterozygosity with the c.769 C>T variation. Expanded epidemiological investigations based on AIRE gene sequencing are necessary to verify the relevancy of the novel mutation to APECED etiopathogenesis in the Lithuanian population and to prove its diagnostic efficacy in association with clinical and immunological findings.     

Candidate-gene exclusion in a family with inherited non-syndromic dental disorders

Objectives

Amelogenesis imperfecta, dentinogenesis imperfecta, and dentin dysplasia are the most common non-syndromic dental disorders. In this study, we analysed and localised the gene(s) responsible for inherited non-syndromic dental disorders in a Chinese family.

Methods

This study identified and researched non-syndromic dental disorders in a four-generation Chinese family, including four affected individuals whose clinical phenotype was atypical. Linkage analysis with seven polymorphic markers that localise to six different autochromosomes showed that the family was linked through chromosome 4q. All exons and exon–intron boundaries of dentin sialophosphoprotein (DSPP), enamelin (ENAM), and ameloblastin (AMBN), which are located on chromosome 4q, were sequenced in nine of the family members.

Results

Direct DNA sequence analysis revealed the existence of a G to A transversion in exon 4 (g.13081786G > A, c.727G > A, p.Asp243Asn, based on reference sequences NM_014208.3) of the DSPP gene, and this sequence variation correlated exactly with the presence of the disease.

Conclusion

These results indicate that mutation p.Asp243Asn is a highly probable cause of non-syndromic dental disorder in this Chinese family. The presence of symptom heterogeneity is possible, as the clinical classification system is hampered by the lack of close correlation between the subtype and the molecular defect.     

Effect of periplasmic expression of recombinant mouse interleukin-4 on hydrogen peroxide concentration and catalase activity in Escherichia coli

Oxidative stress occurs as a result of imbalance between generation and detoxification of reactive oxygen species (ROS). This kind of stress was rarely discussed in connection with foreign protein production in Escherichia coli. Relation between cytoplasmic recombinant protein expression with H₂O₂ concentration and catalase activity variation was already reported. The periplasmic space of E. coli has different oxidative environment in relative to cytoplasm and there are some benefits in periplasmic expression of recombinant proteins. In this study, hydrogen peroxide concentration and catalase activity following periplasmic expression of mouse IL-4 were measured in E. coli. After construction of pET2mIL4 plasmid, the expression of recombinant mouse interleukin-4 (mIL-4) was confirmed. Then, the H₂O₂ concentration and catalase activity variation in the cells were studied in exponential and stationary phases at various ODs and were compared to those of wild type cells and empty vector transformed cells. It was revealed that empty vector introduction and periplasmic recombinant protein expression increased significantly the H₂O₂ concentration of the cells. However, the H₂O₂ concentration in mIL-4 expressing cells was significantly higher than its concentration in empty vector transformed cells, demonstrating more effects of recombinant mIL-4 expression on H₂O₂ elevation. Likewise, although catalase activity was reduced in foreign DNA introduced cells, it was more lowered following expression of recombinant proteins. Correlation between H₂O₂ concentration elevation and catalase activity reduction with cell growth depletion is also demonstrated. It was also found that recombinant protein expression results in cell size increase.     

The XRCC1 Arg280His polymorphism contributes to cancer susceptibility: an update by meta-analysis of 53 individual studies

The X-ray repair cross-complementing group 1 (XRCC1) protein plays a central role in DNA repair pathways. Epidemiological studies have revealed the association between XRCC1 Arg280His polymorphism and cancer risk, but the results were inconsistent. We conducted this meta-analysis to assess the effect of XRCC1 Arg280His polymorphism on cancer susceptibility with accumulated data. Up to January 2012, 53 case‐control studies with 21,349 cases and 23,649 controls were available for our study. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) for XRCC1 Arg280His polymorphism and cancer were estimated using fixed‐ or random-effects models when appropriate. Our meta-analysis identified that elevated cancer risk was statistically associated with the minor variant His allele and Arg–His/His–His genotypes both in the overall population (allele comparison, His versus Arg: OR = 1.16; 95% CI: 1.08–1.25; dominant comparison, Arg–His/His–His versus Arg–Arg: OR = 1.17; 95% CI: 1.08–1.27) and in terms of subgroup analyses by ethnicity for both Caucasians and non‐Caucasians. However, no significant result was observed in the stratified analysis by cancer type. Moreover, significantly increased cancer risk was observed in smokers. These findings indicated that XRCC1 Arg280His polymorphism may play a role in cancer development.     

A peculiar mutation in the DNA-binding/dimerization domain of NFIX causes Sotos-like overgrowth syndrome: A new case

The Nuclear Factor I-X (NFIX) is a member of the nuclear factor I (NFI) family proteins, which are implicated as site-specific DNA-binding proteins and is deleted or mutated in a subset of patients with Sotos-like overgrowth syndrome and in patients with Marshall–Smith syndrome. We evaluated an additional patient with clinical features of Sotos-like syndrome by sequencing analysis of the NFIX gene and identified a 21 nucleotide in frame deletion predicting loss of 7 amino acids in the DNA-binding/dimerization domain of the NFIX protein. The deleted residues are all evolutionally conserved amino acids. The present report further confirms that mutations in DNA-binding/dimerization domain cause haploinsufficiency of the NFIX protein and strongly suggests that in individuals with Sotos-like features unrelated to NSD1 changes genetic testing of NFIX should be considered.