Effects of myonectin on porcine intramuscular adipocyte differentiation and exogenous free fatty acid utilization.

As an important factor secreted by skeletal muscle, myonectin can regulate lipid metabolism and energy metabolism, but its role in the utilization of peripheral free fatty acids (FFAs) by porcine intramuscular fat cells remains to be further investigated. In this study, porcine intramuscular adipocytes were treated with recombinant myonectin and palmitic acid (PA), either alone or in combination, and then were examined for their uptake of exogenous FFAs, intracellular lipid synthesis and catabolism, and mitochondrial oxidation of fatty acids. The results showed that myonectin decreased the area of lipid droplets in intramuscular adipocytes (p < 0.05) and significantly increased (p < 0.05) the expression levels of hormone-sensitive lipase (HSL) and lipoprotein lipase (LPL). Moreover, myonectin can up-regulate the expression of p38 mitogen-activated protein kinase (p38 MAPK). Myonectin significantly promoted the uptake of peripheral FFAs (p < 0.01), improved (p < 0.05) the expression of fatty transport protein 1 (FATP1) and fatty acid binding protein 4 (FABP4) in intramuscular adipocytes. Myonectin also significantly increased (p < 0.05) the expression levels of fatty acid oxidation markers: transcription factor (TFAM), uncoupling protein-2 (UCP2) and oxidative respiratory chain marker protein complex I (NADH-CoQ) in mitochondria of intramuscular adipocytes. In summary, myonectin promoted the absorption, transport, and oxidative metabolism of exogenous FFAs in mitochondria, thereby inhibiting lipid deposition in porcine intramuscular adipocytes.

Effects of L-theanine on intestinal morphology, barrier function, and MAPK signaling pathways in diquat-challenged piglets.

This study aimed to explore the protective effects of L-theanine supplementation on the diquat-challenged weaned piglets. A total of 160 weaned piglets were randomly divided into 4 groups using a 2 × 2 two-factor design, there were 4 replicates per group and 10 pigs per replicate. Piglets were fed diets (with 1000 mg/kg L-theanine addition or not), then challenged with diquat or saline on day 7. 21 days after challenge, two pigs from each replicate were selected for sample collection. Results showed that supplement with 1000 mg/kg L-theanine down-regulated the diarrhea rate, serum D-lactate level, tumor necrosis factor-α, and phosphorylation of extracellular regulated protein kinases (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) signaling in pigs without diquat challenge (p < 0.05). While for diquat-challenged piglets, L-theanine addition increased average daily gain, jejunum villus height, and interferon-γ level (p < 0.05). Meanwhile, L-theanine addition decreased the diarrhea rates and mortality, serum D-lactate level, and phosphorylation of ERK and JNK in diquat-challenged pigs (p < 0.05). These results demonstrate that L-theanine pretreatment could alleviate diquat-induced oxidative stress and improve intestinal barrier function in diquat-challenged weaned piglets, which can be attributed to suppression of MAPK phosphorylation signaling pathways.

Cinnamaldehyde affects lipid droplets metabolism after adipogenic differentiation of C2C12 cells.

BACKGROUND: Based on our previous research conducted on cinnamaldehyde (CA) exhibiting its ability to improve the growth performance of fattening pigs and the adipogenesis induction model of C2C12 cells constructed in our laboratory, we explored the effects of CA on the generation and development of lipid droplets (LDs) in adipogenic differentiated C2C12 cells. METHODS AND RESULTS: C2C12 cells were treated with either 0.4 mM or 0.8 mM CA. BODIPY staining and triglyceride measurements were conducted to observe the morphology of LDs, and Western blotting was used to measure the expression of their metabolism-related proteins. The results showed that the average number of LDs in the CA treatment groups was more than the control group (P < 0.05), whereas the average LD size and triglyceride content decreased (P < 0.05). Compared with the control group, the expression levels of fusion-related genes in the LDs of the CA treatment group significantly decreased, while decomposition-related genes and autophagy-related genes in the LDs in C2C12 cells significantly increased (P < 0.01). CONCLUSION: Cinnamaldehyde promoted the decomposition and autophagy of lipid droplets in C2C12 cells and inhibited the fusion of lipid droplets.

Effects of Fermented Bamboo Powder Supplementation on Serum Biochemical Parameters, Immune Indices, and Fecal Microbial Composition in Growing-Finishing Pigs.

This experiment aimed to investigate the effects of fermented bamboo powder (FBP) on the growth performance, serum biochemical parameters, immunoglobulins and inflammatory cytokines, and fecal microbial composition of growing−finishing pigs. A total of 108 barrows (initial body weight, 56.30 ± 0.55 kg) were randomly allocated to three dietary treatments in a 75 d trial, including a control (CON) diet and two FBP supplementation diets. The CON diet was formulated to three-phase diets according to the body weight of pigs, and the FBP diets were formulated used 5.00% (FBP1) or 10.00% (FBP2) FBP to replace the wheat bran in the CON diet, respectively. The results showed that there were no influences on growth performances between the CON diet and FBP addition diets, whereas the 5% FBP addition decreased the feed:gain of pigs compared to the pigs fed the FBP2 diet from d 0−75 (p < 0.05). Meanwhile, the FBP addition increased the high-density lipoprotein cholesterol (HDLC) and immunoglobulin A (IgA) content in serum (linear, p < 0.05), and pigs fed the FBP1 diet had greater HDLC and IgA contents in serum than those in the pigs fed the CON diet (p < 0.05). Microbial analysis showed that the FBP addition diets decreased the abundance of Spirochaetes, and the FBP2 diet increased the abundance of Firmicutes more than the CON diet (p < 0.05). In addition, the pigs fed the FBP2 diet increased the abundance of uncultured_bacterium_f_Lachnospiraceae, Ruminococcaceae_UCG-005, Prevotellaceae_UCG-003, Lachnospiraceae_XPB1014_group, and Lactobacillus more than the CON group (p < 0.05). In conclusion, the FBP supplementation to the diet had no negative effects on the growth performance and exerted beneficial effects on promoting serum biochemical and immune indices, as well as modulating the fecal microbiota of pigs. Therefore, these results showed that the fermented bamboo powder could be one potential fiber-rich ingredient for growing−finishing pigs, and that the recommended addition proportion in the growing−finishing pigs' diet is 5%.

Influence of Lonicera japonica and Radix Puerariae Crude Extracts on the Fecal Microbiome and Nutrient Apparent Digestibility of Finishing Pigs.

This study aims to investigate the influence of adding Lonicera japonica (L. japonica) and Radix Puerariae crude extracts and their mixture to the diet of finishing pigs on their fecal microbes and nutrient apparent digestibility. A total of 72 healthy Duroc × Landrace × Yorkshire crossbred barrows without significant differences in body weight (93 ± 2 kg) were selected and randomly divided into four groups (18 in each group). Three replicate pens per group (six pigs per pen) were used, and two pigs were evaluated for each pen. The groups were fed the following diets: control group (CON), basic diet; chlorogenic acid group (CGA group), basic diet + 1 kg/ton L. japonica crude extract; Pueraria flavonoid group (PF group), basic diet + 1 kg/ton Radix Puerariae crude extract; and mix group (Mix group), basic diet + 0.5 kg/ton L. japonica crude extract + 0.5 kg/ton Radix Puerariae crude extract. The following results were obtained: (1) At the phylum level, Bacteroidetes, Firmicutes, Spirochaetes, Proteobacteria, Fibrobaeteres, and Kiritimatiellaeota were the main components of the fecal microbiota (top 5); the relative abundance of bacteria from phyla Firmicutes significantly increased in the Mix group than in the CON group (p < 0.05). At the genus level, Treponema_2, Rikenellaceae_RC9_gut_group, uncultured_bacterium_f_Lachnospiraceae, uncultured_bacterium_f_Prevotellaceae, and Prevotellaceae_NK3B31_group were the main components of the fecal microbiota (top 5); the relative abundance of bacteria from genus Lactobacillus significantly increased in the Mix group than in the CON group (p < 0.05). Chao1 and Ace counts were significantly higher in group CGA than in the CON group and group Mix (p < 0.05). The alpha and beta diversities and the relative abundance of fecal microbes were higher in all test groups than in the CON group. (2) The protein digestibility was significantly higher in the CGA and PF groups than in the CON group, and the TP digestibility was significantly higher in the CGA than in the CON and Mix groups (p < 0.05). In conclusion, Lonicera japonica and Radix Puerariae crude extract supplementation in the diet significantly changed fecal microbiota and improved the protein and TP digestibility of finishing pigs.

Effect of Melatonin on the In Vitro Maturation of Porcine Oocytes, Development of Parthenogenetically Activated Embryos, and Expression of Genes Related to the Oocyte Developmental Capability.

Melatonin treatment can improve quality and in vitro development of porcine oocytes, but the mechanism of improving quality and developmental competence is not fully understood. In this study, porcine cumulus-oocyte complexes were cultured in TCM199 medium with non-treated (control), 10-5 M luzindole (melatonin receptor antagonist), 10-5 M melatonin, and melatonin + luzindole during in vitro maturation, and parthenogenetically activated (PA) embryos were treated with nothing (control), or 10-5 M melatonin. Cumulus oophorus expansion, oocyte survival rate, first polar body extrusion rate, mitochondrial distribution, and intracellular levels of reactive oxygen species (ROS) and glutathione of oocytes, and cleavage rate and blastocyst rate of the PA embryos were assessed. In addition, expression of growth differentiation factor 9 (GDF9), tumor protein p53 (P53), BCL2 associated X protein (BAX), catalase (CAT), and bone morphogenetic protein 15 (BMP15) were analyzed by real-time quantitative PCR. The results revealed that melatonin treatment not only improved the first polar body extrusion rate and cumulus expansion of oocytes via melatonin receptors, but also enhanced the rates of cleavage and blastocyst formation of PA embryos. Additionally, melatonin treatment significantly increased intraooplasmic level of glutathione independently of melatonin receptors. Furthermore, melatonin supplementation not only significantly enhanced mitochondrial distribution and relative abundances of BMP15 and CAT mRNA, but also decreased intracellular level of ROS and relative abundances of P53 and BAX mRNA of the oocytes. In conclusion, melatonin enhanced the quality and in vitro development of porcine oocytes, which may be related to antioxidant and anti-apoptotic mechanisms.

Adiponectin modulates oxidative stress-induced mitophagy and protects C2C12 myoblasts against apoptosis.

Adiponectin (APN), also known as apM1, Acrp30, GBP28 and adipoQ, is a circulating hormone that is predominantly produced by adipose tissue. Many pharmacological studies have demonstrated that this protein possesses potent anti-diabetic, anti-atherogenic and anti-inflammatory properties. Although several studies have demonstrated the antioxidative activity of this protein, the regulatory mechanisms have not yet been defined in skeletal muscles. The aim of the present study was to examine the cytoprotective effects of APN against damage induced by oxidative stress in mouse-derived C2C12 myoblasts. APN attenuated H2O2-induced growth inhibition and exhibited scavenging activity against intracellular reactive oxygen species that were induced by H2O2. Furthermore, treating C2C12 cells with APN significantly induced heme oxygenase-1 (HO-1) and nuclear factor-erythroid 2 related factor 2 (Nrf2). APN also suppressed H2O2-induced mitophagy and partially inhibited the colocalization of mitochondria with autophagosomes/lysosomes, correlating with the expression of Pink1 and Parkin and mtDNA. Moreover, APN protected C2C12 myoblasts against oxidative stress-induced apoptosis. Furthermore, APN significantly reduced the mRNA and protein expression levels of Bax. These data suggest that APN has a moderate regulatory role in oxidative stress-induced mitophagy and suppresses apoptosis. These findings demonstrate the antioxidant potential of APN in oxidative stress-associated skeletal muscle diseases.