Fatty Acid Oxidation Promotes Cardiomyocyte Proliferation Rate but Does Not Change Cardiomyocyte Number in Infant Mice

Cardiomyocyte proliferation accounts for the increase of cardiac muscle during fetal mammalian heart development. Shortly after birth, cardiomyocyte transits from hyperplasia to hypertrophic growth. Here, we have investigated the role of fatty acid β-oxidation in cardiomyocyte proliferation and hypertrophic growth during early postnatal life in mice. A transient wave of increased cell cycle activity of cardiomyocyte was observed between postnatal day 3 and 5, that proceeded as cardiomyocyte hypertrophic growth and maturation. Assessment of cardiomyocyte metabolism in neonatal mouse heart revealed a myocardial metabolic shift from glycolysis to fatty acid β-oxidation that coincided with the burst of cardiomyocyte cell cycle reactivation and hypertrophic growth. Inhibition of fatty acid β-oxidation metabolism in infant mouse heart delayed cardiomyocyte cell cycle exit, hypertrophic growth and maturation. By contrast, pharmacologic and genetic activation of PPARα, a major regulator of cardiac fatty acid metabolism, induced fatty acid β-oxidation and initially promoted cardiomyocyte proliferation rate in infant mice. As the cell cycle proceeded, activation of PPARα-mediated fatty acid β-oxidation promoted cardiomyocytes hypertrophic growth and maturation, which led to cell cycle exit. As a consequence, activation of PPARα-mediated fatty acid β-oxidation did not alter the total number of cardiomyocytes in infant mice. These findings indicate a unique role of fatty acid β-oxidation in regulating cardiomyocyte proliferation and hypertrophic growth in infant mice

Shengmai San Alleviates Diabetic Cardiomyopathy Through Improvement of Mitochondrial Lipid Metabolic Disorder

Background/Aims: Shengmai San (SMS), prepared from Panax ginseng, Ophiopogon japonicus, and Schisandra chinensisin, has been widely used to treat ischemic disease. In this study, we investigated whether SMS may exert a beneficial effect in diabetic cardiomyopathy through improvement of mitochondrial lipid metabolism. Methods: A leptin receptor-deficient db/db mouse model was utilized, and lean age-matched C57BLKS mice served as non-diabetic controls. Glucose and lipid profiles, myocardial structure, dimension, and function, and heart weight to tibial length ratio were determined. Myocardial ultrastructural morphology was observed with transmission electron microscopy. Protein expression and activity of oxidative phosphorylation (OXPHOS) complex were assessed using western blotting and microplate assay kits. We also observed cellular viability, mitochondrial membrane potential, OXPHOS complex activity, and cellular ATP level in palmitic acid-stimulated H9C2 cardiomyocytes. Changes in the sirtuin (SIRT1)/AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) pathway and mitochondrial uncoupling signaling were assessed using western blotting and quantitative real-time PCR. Results: Leptin receptor-deficient db/db mice exhibit obesity, hyperglycemia, and hyperlipidemia, accompanied by distinct myocardial hypertrophy and diastolic dysfunction. SMS at a dose of 3 g/kg body weight contributed to a recovery of diabetes-induced myocardial hypertrophy and diastolic dysfunction. SMS administration led to an effective restoration of mitochondrial structure and function both in vivo and in vitro. Furthermore, SMS markedly enhanced SIRT1 and p-AMPKα protein levels and decreased the expression of acetylated-PGC-1α and uncoupling protein 2 protein. SMS also restored the depletion of NRF1 and TFAM levels in diabetic hearts and H9C2 cardiomyocytes. Conclusion: The results indicate that SMS may alleviate diabetes-induced myocardial hypertrophy and diastolic dysfunction by improving mitochondrial lipid metabolism

Experimental and DFT studies on aggregation behavior of dodecylsulfonate-based surface active ionic liquids in water and ethylammonium nitrate

The present work aims to systematically study the aggregation behavior of one halogen-free surface active ionic liquid (SAIL), i.e., 1-butyl-3-methylimidazolum dodecylsulfonate ([C(4)mim][C12H25SO3]), in water and ethylammonium nitrate (EAN), respectively. Multiple-state ordered aggregates, viz. lyotropic liquid crystals (LLCs) (normal hexagonal and laminar lyotropic liquid phases, i.e. H-1 and L-alpha phases) and lamellar gels, were facilely tuned only by the concentration of SAIL or solvent type. Furthermore, it is particularly interesting that LLC phases were constructed in H2O while lamellar gels were obtained in the EAN media environment, which were characterized by polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). According to the investigative SAXS patterns, some structural parameters were calculated, suggesting that a higher concentration of SAIL results in a denser arrangement whereas an opposite trend generates because of a higher temperature. FT-IR spectra and density functional theory (DFT) calculations reveal that both strong H-bonding and electrostatic interactions between EAN and the headgroups of [C(4)mim][C12H25SO3] facilitate gelation. For the self-assembled lamellar gels formed by [C(4)mim][C12H25SO3] in EAN, a thermally reversible sol-gel transition was observed by differential scanning calorimetry (DSC). The rheological results show that the H1 phase formed by [C(4)mim][C12H25SO3] in water exhibits a viscoelastic gel-like behavior among the whole frequency region while L-alpha phase displays a viscous behavior at lower frequencies and an elastic behavior at higher frequencies. This work is expected to set a basis for application of the eco-friendly halogen-free SAIL in some fields, e.g. electrochemistry, supramolecular chemistry and drug delivery. (c) 2016 Elsevier B.V. All rights reserved

Reversible Photoresponsive Molecular Alignment of Liquid Crystals at Fluid Interfaces with Persistent Stability

This work demonstrates a noninvasive approach to control alignment of liquid crystals persistently and reversibly at fluid interfaces by using a photoresponsive azobenzene-based surfactant dissolved in an ionic liquid (IL), ethylammonium nitrate (EAN). As the first report on the orientational behavior of LCs at the IL/ LC interface, our study also expands current understanding of alignment control of LCs at the aqueous/LC interface by adding electrolytes into aqueous solutions. The threshold concentration for switching the optical responses of LCs can be changed just by simply manipulating the ratio of EAN to H2O. This work will inspire fundamental studies and novel applications of using the LC-based imaging technique to investigate various chemical and biological events in ILs

A nonionic surfactant-decorated liquid crystal sensor for sensitive and selective detection of proteins

Proteins are responsible for most biochemical events in human body. It is essential to develop sensitive and selective methods for the detection of proteins. In this study, liquid crystal (LC)-based sensor for highly selective and sensitive detection of lysozyme, concanavalin A (Con A), and bovine serum albumin (BSA) was constructed by utilizing the LC interface decorated with a nonionic surfactant, dodecyl beta-Dglucopyranoside. A change of the LC optical images from bright to dark appearance was observed after transferring dodecyl beta-D-glucopyranoside onto the aqueous/LC interface due to the formation of stable self-assembled surfactant monolayer, regardless of pH and ion concentrations studied in a wide range. The optical images turned back from dark to bright appearance after addition of lysozyme, Con A and BSA, respectively. Noteworthy is that these proteins can be further distinguished by adding enzyme inhibitors and controlling incubation temperature of the protein solutions based on three different interaction mechanisms between proteins and dodecyl beta-D-glucopyranoside, viz. enzymatic hydrolysis, specific saccharide binding, and physical absorption. The LC-based sensor decorated with dodecyl beta-Dglucopyranoside shows high sensitivity for protein detection. The limit of detection (LOD) for lysozyme, Con A and BSA reaches around 0.1 mg/mL, 0.01 mg/mL and 0.001 mg/mL, respectively. These results might provide new insights into increasing selectivity and sensitivity of LC-based sensors for the detection of proteins. (C) 2016 Elsevier B.V. All rights reserved

A liquid crystal-based sensor for the simple and sensitive detection of cellulase and cysteine

A liquid crystal (LC)-based sensor, which is capable of monitoring enzymatic activity at the aqueous/LC interface and detecting cellulase and cysteine (Cys), was herein reported. When functionalized with a surfactant, dodecyl beta-D-glucopyranosicie, the 4-cyano-4'-pentylbiphenyl (5CB) displays a dark-to-bright transition in the optical appearance for cellulase. We attribute this change to the orientational transition of LCs, as a result of enzymatic hydrolysis between cellulase and surfactant. Furthermore, by adding cellulase and Cu2+, our surfactant-LCs system performs an interesting ability to detect Cys, even though Cys could not interact with surfactant or LC directly. Alternatively, through the strong binding between Cys and Cu2+, cellulase was able to hydrolyze surfactant in the presence of Cu2+, leading to the transition of LCs from dark to bright. The detection limit of the LC sensor was around 1 x 10(-5) mg/mL and 82.5 mu M for cellulase and Cys, respectively. The LC-based sensor may contribute to the development of low-cost, expedient, and label-free detection for cellulase and Cys and the design strategy may also provide a novel way for detecting multiple analytes. (C) 2016 Elsevier B.V. All rights reserved