Reversine promotes browning of white adipocytes by suppressing miR-133a

Brown adipocytes are characterized by a high number of uncoupling protein 1 (UCP1)-positive mitochondrial content and increased thermogenic capacity. As UCP1-enriched cells can consume lipids by generating heat, browning of white adipocytes is now highlighted as a promising approach for the prevention of obesity and obesity-associated metabolic diseases. Upon cold exposure or β-adrenergic stimuli, downregulation of microRNA-133 (miR-133) elevates the expression levels of PR domain containing 16 (Prdm16), which has been shown to be a brown adipose determination factor, in brown adipose tissue and subcutaneous white adipose tissues (WAT). Here, we show that treatment of reversine to white adipocytes induces browning via suppression of miR-133a. Reversine treatment promoted the expression of brown adipocyte marker genes, such as Prdm16 and UCP1, increasing the mitochondrial content, while decreasing the levels of miR-133a and white adipocyte marker genes. Ectopic expression of miR-133a mimic reversed the browning effects of the reversine treatment. Moreover, intraperitoneal administration of reversine in mice upregulated thermogenesis and resulted in resistance to high-fat diet-mediated weight gain as well as browning of subcutaneous and epididymal WAT. Taken together, we found a novel way to promote browning of white adipocytes through downregulation of miR-133a followed by activation of Prdm16, with a synthetic chemical, reversine.     

Eugenol Inhibits the GABAA Current in Trigeminal Ganglion Neurons

Eugenol has sedative, antioxidant, anti-inflammatory, and analgesic effects, but also serves as an irritant through the regulation of a different set of ion channels. Activation of gamma aminobutyric acid (GABA) receptors on sensory neurons leads to the stabilization of neuronal excitability but contributes to formalin-induced inflammatory pain. In this study, we examined the effect of eugenol on the GABA-induced current in rat trigeminal ganglia (TG) neurons and in human embryonic kidney (HEK) 293 cells expressing the GABAA receptor α1β2γ2 subtype using the whole-cell patch clamp technique. RT-PCR and Western blot analysis were used to confirm the expression of GABA_A receptor γ2 subunit mRNA and protein in the TG and hippocampus. Eugenol decreased the amplitude ratio of the GABA-induced current to 27.5 ± 3.2% (p < 0.05) in TG neurons, which recovered after a 3-min washout. In HEK 293 cells expressing the α1β2γ2 subtype, eugenol inhibited GABA-induced currents in a dose-dependent manner. Application of eugenol also decreased the GABA response in the presence of a G-protein blocker. Eugenol pretreatment with different concentrations of GABA resulted in similar inhibition of the GABA-induced current in a non-competitive manner. In conclusion, eugenol inhibits the GABA-induced current in TG neurons and HEK 293 cells expressing the GABA_A receptor in a reversible, dose-dependent, and non-competitive manner, but not via the G-protein pathway. We suggest that the GABA_A receptor could be a molecular target for eugenol in the modulation of nociceptive information.     

Characterization of Phase Transition in the Thalamocortical System during Anesthesia-Induced Loss of Consciousness

The thalamocortical system plays a key role in the breakdown or emergence of consciousness, providing bottom-up information delivery from sensory afferents and integrating top-down intracortical and thalamocortical reciprocal signaling. A fundamental and so far unanswered question for cognitive neuroscience remains whether the thalamocortical switch for consciousness works in a discontinuous manner or not. To unveil the nature of thalamocortical system phase transition in conjunction with consciousness transition, ketamine/xylazine was administered unobtrusively to ten mice under a forced working test with motion tracker, and field potentials in the sensory and motor-related cortex and thalamic nuclei were concomitantly collected. Sensory and motor-related thalamocortical networks were found to behave continuously at anesthesia induction and emergence, as evidenced by a sigmoidal response function with respect to anesthetic concentration. Hyperpolarizing and depolarizing susceptibility diverged, and a non-discrete change of transitional probability occurred at transitional regimes, which are hallmarks of continuous phase transition. The hyperpolarization curve as a function of anesthetic concentration demonstrated a hysteresis loop, with a significantly higher anesthetic level for transition to the down state compared to transition to the up state. Together, our findings concerning the nature of phase transition in the thalamocortical system during consciousness transition further elucidate the underlying basis for the ambiguous borderlines between conscious and unconscious brains. Moreover, our novel analysis method can be applied to systematic and quantitative handling of subjective concepts in cognitive neuroscience.     

Multiple In Vivo Biological Processes Are Mediated by Functionally Redundant Activities of Drosophila mir-279 and mir-996

While most miRNA knockouts exhibit only subtle defects, a handful of miRNAs are profoundly required for development or physiology. A particularly compelling locus is Drosophila mir-279, which was reported as essential to restrict the emergence of CO₂-sensing neurons, to maintain circadian rhythm, and to regulate ovarian border cells. The mir-996 locus is located near mir-279 and bears a similar seed, but they otherwise have distinct, conserved, non-seed sequences, suggesting their evolutionary maintenance for separate functions. We generated single and double deletion mutants of the mir-279 and mir-996 hairpins, and cursory analysis suggested that miR-996 was dispensable. However, discrepancies in the strength of individual mir-279 deletion alleles led us to uncover that all extant mir-279 mutants are deficient for mature miR-996, even though they retain its genomic locus. We therefore engineered a panel of genomic rescue transgenes into the double deletion background, allowing a pure assessment of miR-279 and miR-996 requirements. Surprisingly, detailed analyses of viability, olfactory neuron specification, and circadian rhythm indicate that miR-279 is completely dispensable. Instead, an endogenous supply of either mir-279 or mir-996 suffices for normal development and behavior. Sensor tests of nine key miR-279/996 targets showed their similar regulatory capacities, although transgenic gain-of-function experiments indicate partially distinct activities of these miRNAs that may underlie that co-maintenance in genomes. Altogether, we elucidate the unexpected genetics of this critical miRNA operon, and provide a foundation for their further study. More importantly, these studies demonstrate that multiple, vital, loss-of-function phenotypes can be rescued by endogenous expression of divergent seed family members, highlighting the importance of this miRNA region for in vivo function.     

Analysis of relation between skin elasticity and the entropy of skin image using near‐infrared and visible light sources

Skin elasticity has been regarded as one of the main indicators of skin condition. Current measurement devices for skin elasticity are mostly expensive for home‐use and should contact the skin surface. As a first step to develop improved methods, we focus on the relation between skin elasticity and the entropy of skin images. Reduced skin elasticity causes wrinkles. It spreads frequency components and increases their randomness in the frequency domain. The randomness is quantified as entropy, which is a measure of the disorder of a system in physics. Therefore, skin elasticity is expected to have a negative relation with entropy. This tendency can be improved by applying penetration depth characteristics according to the wavelength of light. From cheeks and forehead of 12 Korean adults, skin images are acquired with three different light sources (470 nm, 870 nm and broadband light) and skin elasticity is measured. The root mean square error between the measured data and the fitted model is “0.27” (870 nm), “0.49” (broadband light) and “1.42” (470 nm). Furthermore, the results are analyzed by classifying by sex, age and measurement area. This study demonstrates the possibility of developing noncontact home‐use devices to measure skin elasticity in the future.     

Profiling Differentially Abundant Proteins by Overexpression of Three Putative Methyltransferases in Xanthomonas axonopodis pv. glycines

Methyltransferases (MTases) are enzymes that modify specific substrates by adding a methyl group using S‐adenosyl‐l ‐methionine. Functions of MTases have been extensively studied in eukaryotic organisms and animal pathogenic bacteria. Despite their importance, mechanisms underlying MTase function in plant pathogenic bacteria have not been studied in depth, as is the case of Xanthomonas axonopodis pv. glycines (Xag) that causes bacterial pustule disease in soybean crops worldwide. Here, the association between Xag proteome alterations and three MTase‐overexpressing strains, Xag(XgMT1), Xag(XgMT2), and Xag(XgMT3), compared to Xag carrying an empty vector, Xag(EV) is reported. Using label‐free shotgun comparative proteomic analysis, proteins are identified in all three biological replicates of the four strains and ranged from 1004 to 1082. In comparative analyses, 124, 135, and 134 proteins are differentially changed (over twofold) by overexpression of XgMT1, XgMT2, and XgMT3, respectively. These proteins are also categorized using cluster of orthologous group (COG) analyses, allowing postulation of biological mechanisms associated with three MTases in Xag. COGs reveal that the three MTases may play distinct roles, although some functions may overlap. These results are expected to allow new insight into understanding and predicting the biological functions of MTases in plant pathogenic bacteria. Data are available via ProteomeXchange (Identifier PXD012590).