The novel E3 ligase of PPAR?? TRIM25 regulates adipocyte differentiation

Department of Biological SciencesPeroxisome proliferator-activated receptor ?? (PPAR??) is a ligand-dependent transcription factor which regulates glucose homeostasis and adipocyte differentiation. Its transcriptional activity is regulated by not only ligands but also post-translational modifications (PTMs). In this study, we demonstrate a novel E3 ligase of PPAR??, TRIM25 directly induces ubiquitination of PPAR?? followed by proteasome-dependent degradation. During the adipocyte differentiation, both mRNA and protein expression of TRIM25 significantly decreased and negatively correlated with the expression of PPAR??. Stable expression of TRIM25 reduces PPAR?? protein levels, but not mRNA expression, and suppressed adipocyte differentiation in 3T3-L1 cells. In contrast, specific knock-down of TRIM25 increases PPAR?? protein levels and stimulates adipocyte differentiation. Furthermore, TRIM25 knock-out mouse embryonic fibroblast (MEFs) shows an increased ability for adipocyte differentiation compared with wild-type MEFs. Taken together, these data indicate that TRIM25 is a novel E3 ubiquitin ligase of PPAR??, and depict TRIM25 as a novel target for PPAR??-involved metabolic diseases.ope

Gauge Coupling Unification in Six Dimensions

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Running inflation with unitary Higgs

We consider the renormalization group(RG) improved inflaton potential in unitarized Higgs inflation where the original Higgs inflation is unitarized by the addition of a real singlet scalar of sigma-model type. The sigma field coupling to the Higgs, which is introduced to reproduce a large non-minimal coupling of the Higgs below the sigma scalar threshold, also improves the Standard Model vacuum stability due to the RG running. Furthermore, the same sigma field coupling determines the reheating temperature or the number of efoldings. Considering the uncertainties in the number of efoldings in the model, we show that the loop-corrected spectral index and tensor-to-scalar ratio are consistent with nine-year WMAP and new Planck data within 1sigma.Comment: 19 pages, 8 figures, version to appear in Phys. Lett. B, typos correcte

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We give a review on the thermal average of the annihilation cross-sections for $3\rightarrow 2$ and general higher-order processes. Thermal average of higher order annihilations highly depend on the velocity of dark matter, especially, for the case with resonance poles. We show such examples for scalar dark matter in gauged $Z_3$ models.Comment: 5 pages, 2 figures, Prepared for the proceedings of the 13th International Conference on Gravitation, 3-7 July 201

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We give a review on the SIMP paradigm and discuss a consistent model for SIMP dark mesons in the context of a dark QCD with flavor symmetry. The $Z'$-portal interaction is introduced being compatible with stable dark mesons and is responsible for making the SIMP dark mesons remain in kinetic equilibrium with the SM during the freeze-out process. The SIMP parameter space of the $Z'$ gauge boson can be probed by future collider and direct detection experiments.Comment: 4 pages, no figures, To appear in the proceedings of PPC 2015 conference, Deadwood, South Dakota, US

Reheating the Universe at Criticality

We present the general discussion on the inflection point inflation with small or large inflaton fields and show the effects of reheating dynamics on the inflationary predictions. In order to compare the model predictions with precisely measured CMB anisotropies and constrain the inflation models, the knowledge of the reheating dynamics is required. Inflection point inflation extended to the trans-Planckian regime can accommodate a sizable tensor-to-scalar ratio at the detectable level in the future CMB experiments.Comment: 6 pages, 2 figures, To appear in the proceedings of CosPA 2015 conferenc