Inhibition of alpha-hemolysin expression by resveratrol attenuates Staphylococcus aureus virulence.

Staphylococcus aureus is an important zoonotic pathogen that causes a variety of life-threatening diseases. The increasing emergence of drug resistance further complicates the treatment of S. aureus infections. The critical role of alpha-hemolysin (Hla) in virulence renders this toxin an ideal target for the development of anti-infective agents for S. aureus. Here, We found that resveratrol, a natural compound widely found in fruits without antibacterial activity, could effectively inhibit Hla expression via down-regulating the transcription of hla, the gene that encodes Hla, and RNAIII, the effector molecule of the agr system. The addition of resveratrol to a co-culture system of S. aureus and A549 cells significantly alleviated bacteria-mediated cellular injury. Furthermore, treatment with resveratrol effectively protected mice from S. aureus pneumonia. Our results established resveratrol as an effective Hla inhibitor that reduces Hla expression without antimicrobial activity and can be further developed into novel therapeutics against S. aureus infections.

Cloning and transcriptional activity analysis of the porcine cofilin 2 gene promoter.

Cofilins (CFL), including CFL1 and CFL2, are members of the family of actin-binding proteins in eukaryote. CFL2 is predominantly expressed in mammalian skeletal muscle and heart and is important to muscle fiber formation and muscular regeneration. To study transcriptional regulation of porcine CFL2, a 2.5 kb upstream sequence starting from the major CFL2 transcriptional start site was cloned by genome walking. Twelve DNA fragments of the 5' flank region of the porcine CFL2 gene were further isolated from porcine genomic DNA via PCR and inserted into the luciferase reporter vector pGL4.10 to make 12 CFL2 reporter constructs. All reporter vectors were transfected into C2C12, NIH3T3, or Hela cells and their relative luciferase activity measured after 48 h, respectively. Bioinformatics analysis suggested that there were two TATA-boxes at the -508 bp and -453 bp, as well as a GC-box and a CAAT-box in this sequence. Additional transcription factor binding sites including SP1, AP1, AP2, and GATA-1 sites were also predicted. The transcriptional activity of pGL4.10-1554 (1502 bp to +51 bp) was the strongest, and the promoter's active region was mapped to a region from -1502 bp to -1317 bp. Our data provide a foundation for future studies into transcriptional regulation of CFL2.

Single-nucleotide polymorphisms and activity analysis of the promoter and enhancer of the pig lactase gene.

Lactose intolerance in northern Europeans is strongly associated with a single-nucleotide polymorphism (SNP) located 14 kb upstream of the human lactase gene: -13,910 C/T. We examined whether SNPs in the 5' flanking region of the pig lactase gene are similar to those in the human gene and whether these polymorphisms play a functional role in regulating pig lactase gene expression. The 5' flanking region of the lactase gene from several different breeds of pigs was cloned and analyzed for gene regulatory activity of a luciferase reporter gene. One SNP was found in the enhancer region (-797 G/A) and two were found in the promoter region (-308G/C and -301 A/G). The promoter C-308,G-301(Pro-CG) strongly promotes the expression of the lactase gene, but the promoter G-308,A-301(Pro-GA) does not. The enhancer A-797(Enh-A) genotype for Pro-GA can significantly enhance promoter activity, but has an inhibitory effect on Pro-CG. The Enhancer G-797(Enh-G) has a significant inhibitory effect on both promoters. In conclusion, the order of effectiveness on the pig lactase gene is Enh-A+Pro-GA>Enh-A/G+Pro-CG>Enh-G+Pro-GA.

[A family of congenital fibrosis of extraocular muscles associated with juvenile canities].

OBJECTIVE: To analyze the clinical manifestations of affected individuals in a family of congenital fibrosis of the extraocular muscles (CFEOM) with juvenile canities. METHODS: All affected and unaffected individuals were retrospectively analyzed in this study. The clinical features include genetic aspects, sex, age, ptosis, restriction of eye movement, aberrant innervation and surgical procedures, were evaluated. RESULTS: This pedigree was inherited as autosomal dominant. There were 14 cases suffering from congenital fibrosis of extraocular muscles in four generations. They had congenital blepharoptosis, head-tilt, chin lift and primary gaze fixed in a hypotrophic position. But vertical and horizontal positions of the eye and restriction of eye movement were different among affected individuals. Some of them also had pupillary abnormally, aberrant innervation and juvenile canities. Inferior rectus recession improved hypotropia in patients with infraducted eyes and chin elevation. Horizontal muscle recession corrected horizontal strabismus satisfactorily in most cases. Ptosis was repaired by frontalis sling or levator resection. CONCLUSIONS: This is the first report of CFEOM associated with juvenile canities. There was phenotypic heterogeneity in this CFEOM pedigree. So the phenotype alone is not sufficient to distinguish among the 3 genotypically distinct CFEOM syndromes. The combination of clinical characteristics and genetic analysis are the basis for the establishment of diagnosis.

[Advances in clinical and molecular genetics of congenital cranial dysinnervation disorders].

Congenital cranial dysinnervation disorders (CCDDs) are congenital non-progressive, sporadic or familial abnormalities of cranial musculature that result from developmental abnormalities of, or the complete absence of, one or more cranial nerves with primary or secondary muscle dysinnervation. These disorders include vertical disorders of ocular motility, horizontal disorders of ocular motility and disorders with abnormalities of facial motility that were previously referred to as "congenital fibrosis syndromes". The advances in clinical and molecular genetics of congenital cranial dysinnervation disorders are reviewed.