Sequestration of LINE-1 in novel cytosolic bodies by MOV10 restricts retrotransposition

LINE-1 (L1) are autonomous retroelements that have retained their ability to mobilize. Mechanisms regulating L1 mobility include DNA methylation in somatic cells and the Piwi-interacting RNA pathway in the germline. During pre-implantation stages of mouse embryonic development, however, both pathways are inactivated leading to a critical window necessitating alternate means of L1 regulation. We previously reported an increase in L1 levels in Dicer_KO mouse embryonic stem cells (mESCs). Intriguingly this was accompanied by only a marginal increase in retrotransposition, suggestive of additional mechanisms suppressing L1 mobility. Here, we demonstrate that L1 Ribonucleoprotein complexes (L1 RNP) accumulate as aggregates in Dicer_KO cytoplasm along with the RNA helicase MOV10. The combined overexpression of L1 RNAs and MOV10 is sufficient to create L1 RNP aggregates in stem cells. In Dicer_KO mESCs, MOV10 is upregulated due to the loss of its direct regulation by miRNAs. The newly discovered post-transcriptional regulation of Mov10 expression, and its role in preventing L1 retrotransposition by driving novel cytosolic aggregation affords alternate routes to explore for therapy and disease progression.

Localized temporal co-delivery of interleukin 10 and decorin genes using amediated by collagen-based biphasic scaffold modulates the expression of TGF-β1/β2 in a rabbit ear hypertrophic scarring model

The study shows that although pIL-10/pDCN therapy are individually able to suppress TGF-β1/β2, only the combined overexpression of both transgenes was efficacious in suppressing TGF-β1/β2 and concurrently sustaining the upregulation of TGF-β3.

Combined overexpression of SIRT1 and knockout of GCN5 in adult skeletal muscle does not affect glucose homeostasis or exercise performance in mice

Sirtuin 1 (SIRT1) and general control of amino acid synthesis 5 (GCN5) regulate mitochondrial biogenesis via opposing modulation of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) acetylation status and activity. However, the combined contribution of SIRT1 and GCN5 to skeletal muscle metabolism and endurance performance in vivo is unknown. In this study, we investigated the impact of combined skeletal muscle-specific overexpression of SIRT1 and deletion of GCN5 on glucose homeostasis, skeletal muscle mitochondrial biogenesis and function, and metabolic adaptation to endurance exercise training in mice. We generated mice with combined and tamoxifen-inducible skeletal muscle-specific overexpression of SIRT1 and knockout of GCN5 (dTG) and floxed [wild type (WT)] littermates using a Cre-LoxP approach. All mice were treated with tamoxifen at 5–6 wk of age, and 4–7 wk later glucose homeostasis, skeletal muscle contractile function, mitochondrial function, and the effects of 14 days of voluntary wheel running on expression of metabolic proteins and exercise capacity were assessed. There was no difference in oral glucose tolerance, skeletal muscle contractile function, mitochondrial abundance, or maximal respiratory capacity between dTG and WT mice. Additionally, there were no genotype differences in exercise performance and markers of mitochondrial biogenesis after 14 days of voluntary wheel running. These results demonstrate that combined overexpression of SIRT1 and loss of GCN5 in vivo does not promote metabolic remodeling in skeletal muscle of sedentary or exercise-trained mice.

ALKBH overexpression in head and neck cancer: potential target for novel anticancer therapy

The nine identified human homologues of E. coli AlkB 2-oxoglutarate (2OG) and Fe(II)-dependent dioxygenase, ALKBH1-8 and FTO, display different substrate specificities and diverse biological functions. Here we discovered the combined overexpression of members of the ALKBH family in head and neck squamous cell carcinomas (HNSCC). We found direct correlation of ALKBH3 and FTO expression with primary HNSCC tumor size. We observed unidentified thus far cytoplasmic localization of ALKBH2 and 5 in HNSCC, suggesting abnormal role(s) of ALKBH proteins in cancer. Further, high expression of ALKBHs was observed not only in HNSCC, but also in several cancerous cell lines and silencing ALKBH expression in HeLa cancer cells resulted in dramatically decreased survival. Considering the discovered impact of high expression of ALKBH proteins on HNSCC development, we screened for ALKBH blockers among newly synthetized anthraquinone derivatives and demonstrated their potential to support standard anticancer therapy.

Increased L-Ornithine Production in Corynebacterium glutamicum by Overexpression of a Gene Encoding a Putative Aminotransferase

Overexpression of the NCgl0462 open reading frame, encoding a class II aminotransferase, was studied in conjunction with other enzymes in <smlcap>L</smlcap>-ornithine biosynthesis in an <smlcap>L</smlcap>-ornithine-producing strain. Expression of the wild-type NCgl0462 open reading frame, which displayed aminotransferase activity, was amplified by placing it under the control of the glyceraldehyde 3-phosphate dehydrogenase gene promoter in the pEK0 plasmid and in the genome. <smlcap>L</smlcap>-Ornithine production in <i>Corynebacterium</i><i>glutamicum</i> SJC8260 harboring plasmid and the genomic NCgl0462 open reading frame was increased by 8.8 and 21.6%, respectively. In addition, the combined overexpression of the NCgl0462 open reading frame within the genome along with the mutated <smlcap>L</smlcap>-ornithine biosynthesis genes <i>(argCJBD)</i> placed in the pEK0 plasmid in <i>C</i>. <i>glutamicum</i> SJC8260 resulted in significant improvement in <smlcap>L</smlcap>-ornithine production (12.48 g/l for combined overexpression compared with 8.42 g/l for the control). These results suggest that overexpression of the aminotransferase-encoding NCgl0462 open reading frame plays an unequivocal role in the <smlcap>L</smlcap>-ornithine biosynthetic pathway, with overlapping substrate specificity in <i>C</i>. <i>glutamicum</i>.