Noriaki Maeshige

Changes of hepatic lipid mediators associated with intake of high-fat diet for 12 weeks in endotoxemic rats using LC-ESI-MS/MS

BACKGROUND & AIMSnIt has recently been reported that anti-inflammatory lipid mediators are increased in the late phase of acute inflammation, whereas proinflammatory lipid mediators are regulated at the initiation of inflammation. The purpose of this study was to evaluate changes of hepatic lipid mediators due to high-fat diet (HFD) feeding in endotoxemic rats.nnnMETHODSnMale Wistar rats were fed either HFD or control diet for 12 weeks, and were then killed 0, 1.5, and 6 h after lipopolysaccharide (LPS) injection. Analyses included lipidomics assessment of mediators using liquid chromatography-electrospray ionization/multi-stage mass spectrometry; measuring expression of hepatic polyunsaturated fatty acid (PUFA)-oxidizing enzyme, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and inducible nitric oxide synthase mRNA levels; blood biochemical tests; and liver histology.nnnRESULTSnHFD feeding worsened liver injury, increased expression of TNF-α and IL-6 mRNA, and increased oxidative stress after LPS injection. PUFA-oxidizing enzymes were higher in HFD-fed rats after LPS injection. The proinflammatory prostaglandin (PG)E2 and thromboxane B2 were increased 1.5 h after LPS injection, and had decreased by 6 h in HFD-fed rats. In contrast, potent pro-resolving resolvins derived from eicosapentaenoic acid and docosahexaenoic acid were not detected, but anti-inflammatory epoxyeicosatrienoic acids, lipoxin A4, and 15-deoxy-PGJ2 were increased after LPS injection in HFD-fed rats.nnnCONCLUSIONSnHFD feeding for 12 weeks enhanced proinflammatory lipid mediators 1.5 h after LPS injection suggesting relation to liver injury.

Astaxanthin supplementation attenuates immobilization-induced skeletal muscle fibrosis via suppression of oxidative stress

Immobilization induces skeletal muscle fibrosis characterized by increasing collagen synthesis in the perimysium and endomysium. Transforming growth factor-β1 (TGF-β1) is associated with this lesion via promoting differentiation of fibroblasts into myofibroblasts. In addition, reactive oxygen species (ROS) are shown to mediate TGF-β1-induced fibrosis in tissues. These reports suggest the importance of ROS reduction for attenuating skeletal muscle fibrosis. Astaxanthin, a powerful antioxidant, has been shown to reduce ROS production in disused muscle. Therefore, we investigated the effects of astaxanthin supplementation on muscle fibrosis under immobilization. In the present study, immobilization increased the collagen fiber area, the expression levels of TGF-β1, α-smooth muscle actin, and superoxide dismutase-1 protein and ROS production. However, these changes induced by immobilization were attenuated by astaxanthin supplementation. These results indicate the effectiveness of astaxanthin supplementation on skeletal muscle fibrosis induced by ankle joint immobilization.

Lard-based high-fat diet increases secretory leukocyte protease inhibitor expression and attenuates the inflammatory response of acute lung injury in endotoxemic rats

BACKGROUND & AIMSnAcute lung injury (ALI) is less severe in obese than in nonobese patients, but the mechanism is unclear. Secretory leukocyte protease inhibitor (SLPI) is the key anti-inflammatory protein in various lung diseases. We have previously reported changes of the surgical stress in obese rats using lard-based high-fat diet (HFD). The purpose of this study was to elucidate the effect of lard-based HFD on the pathophysiology of lipopolysaccharide (LPS)-induced ALI, and the role of SLPI expression.nnnMETHODSnMale Wistar rats were fed lard-based HFD (60 kcal% fat) or control diet (CD) for either 4 or 12 weeks and were killed after intraperitoneal LPS injection. Analyses included messenger RNA expression of TNF-α, macrophage inflammatory protein (MIP)-2, inducible nitric oxide synthase (iNOS), IL-10 and SLPI in the lung tissue and bronchoalveolar lavage fluid, and histology of the lungs.nnnRESULTSnRats fed HFD for 12 weeks showed suppression of the lung injury and oxidative stress after LPS injection, as indicated by reduction of pulmonary TNF-α, MIP-2 and iNOS mRNA expression and 8-hydroxy-2-deoxyguanosine immunostaining. The increased pulmonary SLPI caused by lard was associated with decreased pro-inflammatory cytokines and oxidative stress, which eventually resulted in the prevention of ALI. Those effects of lard on LPS-induced ALI were greater after 12 weeks than after 4 weeks feeding, as indicated by the reduction of TNF-α, MIP-2 and iNOS levels.nnnCONCLUSIONSnFeeding lard-based HFD for 12 weeks attenuated LPS-induced ALI with increased pulmonary SLPI expression in rats.

Oral tributyrin prevents endotoxin-induced lipid metabolism disorder

BACKGROUND & AIMSnSepsis leads to dysregulation of lipid and lipoprotein metabolism. Butyrate increases peroxisome proliferator-activated receptors (PPARs), which are key nuclear hormone receptors to induce fatty acid oxidation and synthesis. Oral administration of tributyrin, a prodrug of butyrate contained in dairy products, suppresses lipopolysaccharide (LPS)-induced liver injury through attenuating nuclear factor-κB activity with an increased hepatoportal butyrate level. In this study, we elucidated the protective effect of oral administration of tributyrin against LPS-mediated lipid metabolism disorder in rats.nnnMETHODSnMale Wistar rats were randomly divided and were administered tributyrin or vehicle orally 1xa0h before LPS injection and then sacrificed at 0, 1.5, 6, and 24xa0h after LPS. Liver tissue expressions of nuclear hormone receptors, enzymes associated with fatty acid metabolism, and histone acetylation were analyzed by real-time polymerase chain reaction or western blotting. Plasma lipids levels were measured.nnnRESULTSnTributyrin enhanced expression of PPARs and histone H3 in the liver at basal levels. Tributyrin suppressed LPS-induced repression of PPARs fatty acid oxidation-associated enzymes: fatty acid transport protein and fatty acid binding protein, and fatty acid synthesis-associated enzyme: sterol regulatory element binding protein-1c. Tributyrin reduced the increase in plasma triglyceride, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels at 24xa0h after LPS injection.nnnCONCLUSIONSnOral tributyrin administration prevented elevation of plasma triglyceride, TC, and LDL-C levels through improved fatty acid oxidation in endotoxemic rats.

Preventive effects of nucleoprotein supplementation combined with intermittent loading on capillary regression induced by hindlimb unloading in rat soleus muscle

Physical inactivity leads to muscle atrophy and capillary regression in the skeletal muscle. Intermittent loading during hindlimb unloading attenuates the muscle atrophy, meanwhile the capillary regression in the skeletal muscle is not suppressed. Nucleoprotein has antioxidant capacity and may prevent capillary regression. Therefore, we assessed the combined effects of intermittent loading with nucleoprotein supplementation on capillary regression induced by hindlimb unloading. Five groups of rats were assigned: control (CON), 7 days hindlimb unloading (HU), HU plus nucleoprotein supplementation (HU + NP), intermittent loading during HU (HU + IL), and intermittent loading combined with nucleoprotein supplementation during HU (HU + IL + NP). Seven days HU resulted in decrease in capillary number‐to‐fiber number (C/F) ratio accompanied with disuse‐associated changes in fetal liver kinase‐1 (Flk‐1), a proangiogenesis factor, and thrombospondin‐1 (TSP‐1), an antiangiogenesis factor, in the soleus muscle. In addition, citrate synthase (CS) activity was decreased and protein level of superoxide dismutase (SOD)‐2 was increased. Neither nucleoprotein supplementation nor intermittent loading prevented the decrease in the C/F ratio, whereas nucleoprotein supplementation combined with intermittent loading prevented the regression of capillary during unloading. Moreover, the levels of Flk‐1, TSP‐1, and SOD‐2 protein and the CS activity were maintained up to control levels. These results suggested that nucleoprotein supplementation combined with intermittent loading was effective to prevent capillary regression induced by muscle atrophy.

Enterococcus faecium strain R30 increases red blood cell velocity and prevents capillary regression in the soleus of hindlimb unloaded rats via the eNOS/VEGF pathway

A chronic decrease in neuromuscular activity results in atrophy and capillary regression in skeletal muscles. The purposes of this study were to determine the effects of Enterococcus faecium strain R30 (R30) administration on (i) the hemodynamics of the rat soleus muscle, and (ii) the capillary regression normally associated with HU.

Nucleoprotein supplementation enhances the recovery of rat soleus mass with reloading after hindlimb unloading–induced atrophy via myonuclei accretion and increased protein synthesis

Hindlimb unloading results in muscle atrophy and a period of reloading has been shown to partially recover the lost muscle mass. Two of the mechanisms involved in this recovery of muscle mass are the activation of protein synthesis pathways and an increase in myonuclei number. The additional myonuclei are provided by satellite cells that are activated by the mechanical stress associated with the reloading of the muscles and eventually incorporated into the muscle fibers. Amino acid supplementation with exercise also can increase skeletal muscle mass through enhancement of protein synthesis and nucleotide supplements can promote cell cycle activity. Therefore, we hypothesized that nucleoprotein supplementation, a combination of amino acids and nucleotides, would enhance the recovery of muscle mass to a greater extent than reloading alone after a period of unloading. Adult rats were assigned to 4 groups: control, hindlimb unloaded (HU; 14 days), reloaded (5 days) after hindlimb unloading (HUR), and reloaded after hindlimb unloading with nucleoprotein supplementation (HUR + NP). Compared with the HUR group, the HUR + NP group had larger soleus muscles and fiber cross-sectional areas, higher levels of phosphorylated rpS6, and higher numbers of myonuclei and myogenin-positive cells. These results suggest that nucleoprotein supplementation has a synergistic effect with reloading in recovering skeletal muscle properties after a period of unloading via rpS6 activation and satellite cell differentiation and incorporation into the muscle fibers. Therefore, this supplement may be an effective therapeutic regimen to include in rehabilitative strategies for a variety of muscle wasting conditions such as aging, cancer cachexia, muscular dystrophy, bed rest, and cast immobilization.

Low-Intensity Ultrasound Enhances Histone Acetylation and Inhibition of Interleukin 6 Messenger RNA Expression by the Histone Deacetylase Inhibitor Sodium Butyrate in Fibroblasts

Sodium butyrate, an inhibitor of histone deacetylase, has several therapeutic actions, including anti‐inflammation. These actions depend on the concentration of sodium butyrate. In addition, lower concentrations have shown no effect on inflammation. Sonoporation by ultrasound can modify the permeability of the cell plasma membrane. Thus, the effects of sodium butyrate may be enhanced by the ultrasonic acoustics. Therefore, the facilitative effects of low‐intensity ultrasound on histone acetylation and interleukin 6 (IL‐6) regulation by sodium butyrate were investigated in this study.

Combination therapy with butyrate and docosahexaenoic acid for keloid fibrogenesis: an in vitro study

Background A single, effective therapeutic regimen for keloids has not been established yet, and the development of novel therapeutic approaches is expected. Butyrate, a short-chain fatty acid, and docosahexaenoic acid (DHA), a ω-3 polyunsaturated fatty acid, play multiple anti-inflammatory and anticancer roles via their respective mechanisms of action. Objective In this study, we evaluated the antifibrogenic effects of their single and combined use on keloid fibroblasts. Methods Keloid fibroblasts were treated with butyrate (0-16 mM) and/or DHA (0-100 µM) for 48 or 96 h. Results Butyrate inhibited cell proliferation, and α-smooth muscle actin (α-SMA) and type III collagen expressions, with inhibition of the transforming growth factor (TGF)-β1 and TGF-β type I receptor expressions and increased prostaglandin E2 with upregulation of cyclooxygenase-1 expression with induction of histone acetylation. DHA inhibited α-SMA, type III collagen, and TGF-β type I receptor expressions. Then, the butyrate/DHA combination augmented the antifibrogenic effects, resulting in additional inhibition of α-SMA, type I and III collagen expressions, with strong disruption of stress fiber and apoptosis induction. Moreover, the butyrate/DHA combination inhibited the cyclooxygenase-2 expression, suggesting stronger anti-inflammatory effect than each monotherapy. Study limitations Activation in keloid tissue is affected not only by fibroblasts but also by epithelial cells and immune cells. Evaluation of the effects by butyrate and DHA in these cells or in an in vivo study is required. Conclusion This study demonstrated that butyrate and docosahexaenoic acid have antifibrogenic effects on keloid fibroblasts and that these may exert therapeutic effects for keloid.