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The enzymatic activity of telomerase is important for the extension of the telomere repeat sequence and overcoming cellular senescence. We generated a conditional transgenic mouse line, carrying the telomerase reverse transcriptase (Tert) expression cassette, controlled by the Cre-loxP-mediated recombination. In our study, Cre recombinase expression efficiently activated Tert expression, resulting in its increased enzymatic activity, which extended the period of cellular proliferation until the keratinocytes entered senescence. This suggests that transgenic Tert expression is effective in enhancing primary cell proliferation. Notably, Tert expression increased colony formation of induced pluripotent stem (iPS) cells after the introduction of four reprogramming factors, Oct-4, klf4, SOX-2, and c-Myc into the transgenic fibroblasts. To the best of our knowledge, this is the first study to show that the transgenic Tert expression enhances reprogramming efficiency of iPS cells, which indicates a critical role for Tert in the reprogramming process.

We developed the AAV-Oxtr-IRES-Venus vector to rescue the oxytocin receptor (Oxtr) gene functionally at restricted regions in the brains of Oxtr knockout mice. First we chose human eIF4G gene-derived IRES to co-express Venus, a fluorescent marker gene, with Oxtr. With selected human eIF4G IRES, we constructed the AAV-Oxtr-IRES-Venus vector, and it caused expression of the Venus gene in the brain when 1 microl of viral solution (9.4x10(7) vg) was injected into the medial amygdaloid nucleus. In primary neuronal cells transduced with this viral vector and followed by oxytocin administration, functional expression of OXTR was detected by Ca(2+) imaging assay.

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>