First Identification of Rare Exonic and Deep Intronic Splice-Altering Variants in Patients With Beta-Sarcoglycanopathy.

Background: The precise genetic diagnosis of a sarcoglycanopathy or dystrophinopathy is sometimes extremely challenging, as pathogenic non-coding variants and/or complex structural variants do exist in DMD or sarcoglycan genes. This study aimed to determine the genetic diagnosis of three patients from two unrelated families with a suspected sarcoglycanopathy or dystrophinopathy based on their clinical, radiological, and pathological features, for whom routine genomic detection approaches failed to yield a definite genetic diagnosis. Methods: Muscle-derived reverse transcription-polymerase chain reaction analysis and/or TA cloning of DMD, SGCA, SGCB, SGCD, and SGCG mRNA were performed to identify aberrant transcripts. Genomic Sanger sequencing around the aberrant transcripts was performed to detect possible splice-altering variants. Bioinformatic and segregation studies of the detected genomic variants were performed in both families. Results: In patients F1-II1 and F1-II2, we identified two novel pathogenic compound heterozygous variants in SGCB. One is a deep intronic splice-altering variant (DISV), c.243 + 1558C > T in intron 2 causing the activation of an 87-base pair (bp) pseudoexon, and the other one is a non-canonical splicing site variant, c.243 + 6T > A leading to the partial intron inclusion of 10-bp sequence. A novel DISV, c.243 + 1576C > G causing a 106-bp pseudoexon activation, and a nonsense variant in SGCB were identified in compound heterozygous state in patient F2-II1. Unexpectedly, the predicted nonsense variant, c.334C > T in exon 3, created a new donor splice site in exon 3 that was stronger than the natural one, resulting in a 97-bp deletion of exon 3 (r.333_429del). Conclusion: This is the first identification of rare exonic and DISVs in the SGCB gene.

Total syntheses of (-)-isoschizogamine and (-)-2-hydroxyisoschizogamine.

Total syntheses of (-)-isoschizogamine and (-)-2-hydroxyisoschizogamine are described. The synthesis employs two asymmetric Michael additions to establish chiral centers at C7 and the quaternary carbon C20. Regioselective reduction of the methylthioiminium cation rather than the enamine generates an isoschizogamine-type pentacyclic skeleton. Acidic hydrolysis of the isoschizogamine-type intermediate in the absence of oxygen provides natural (-)-isoschizogamine. Conducting the reaction in the presence of oxygen leads to a multistep oxidative hydrolysis cascade that affords unnatural (-)-2-hydroxyisoschizogamine.

MiR-374a promotes the proliferation of human osteosarcoma by downregulating FOXO1 expression.

MiRNAs play crucial roles in development of cancer. However, the underlying mechanisms of miRNAs in osteosarcoma (OS) are poorly understood. In the present study, we reported that the expression of miR-374a was markedly upregulated in OS tissues and OS cells compared with the matched adjacent normal tissues and human osteoclast h-FOB cell lines. Overexpression of miR-374a promoted the proliferation and anchorage-independent growth of OS cells, whereas inhibition of miR-374a showed opposite effect. Furthermore, we identified that FOXO1 is the functional target of miR-374a. MiR-374a-induced proliferation was correlated with FOXO1, upregulating of the cell cycle regulator cyclin D1 and downregulating of cyclin-dependent kinase inhibitors p27. In functional assays, FOXO1 downregulation is required for miR-374a-induced OS cell proliferation. In sum, our data provide compelling evidence that a novel mechanism of FOXO1 suppression mediated by miR-374a in OS.

Total syntheses of ainsliadimer B and gochnatiolides a and B.

Oh my goch: The total syntheses of ainsliadimer B and gochnatiolides A and B from α-santonin have been accomplished in 25 steps with approximately 1 % overall yield. A Diels-Alder reaction of natural dehydrozaluzanin C with a monomeric guaianolide derivative allows stereoselective assembly of a dimeric gochnatiolide-type skeleton with the required stereochemistry and preinstalled functionalities for the synthesis of dimeric ainsliadimer B and gochnatiolides A and B (see scheme).

Diversity of culturable bacteria isolated from root domains of moso bamboo (Phyllostachys edulis).

The distribution of culturable bacteria in the rhizosphere, rhizoplane, and interior root tissues of moso bamboo plants was investigated in this study. Of the 182 isolates showing different colony characteristics on Luria-Bertani and King B plates, 56 operational taxonomic units of 22 genera were identified by 16S ribosomal RNA gene sequence analysis. The majority of root endophytic bacteria were Proteobacteria (67.5%), while the majority of rhizospheric and rhizoplane bacteria were Firmicutes (66.3% and 70.4%, respectively). The most common genus in both the rhizosphere and on the rhizoplane was Bacillus (42.4% and 44.4%, respectively), while Burkholderia was the most common genus inside the roots, comprising 35.0% of the isolates from this root domain. The endophytic bacterial community was less diverse than the rhizoplane and rhizospheric bacterial communities. Members of Lysinibacillus, Bacillus, and Burkholderia were found in all three root domains, whereas many isolates were found in only a single domain. Our results show that the population diversity of culturable bacteria is abundant in the root domains of moso bamboo plants and that obvious differences exist among the rhizospheric, rhizoplane, and endophytic bacterial communities.