RNA-seq Was Used to Obtain the Key Genes in the Regulation of Conjugated Linoleic Acid on Intramuscular Fat Metabolism in Royal Chicken / 中国生物化学与分子生物学报

Transcriptome sequencing was used to obtain the differentially expressed genes of conjugated linoleic acid (CLA) on the basal diet of Royal chickens on intramuscular fat metabolism in related signal pathways and candidate genes that may play important roles by bioinformatics analysis, which could provide a further understanding of the molecular mechanism of CLA on intramuscular fat deposition. In this study, 55-day-old healthy Royal chickens were selected as experimental animals, and 0%, 1% and 2% of CLA were added to the basic diet. The pre-feeding period was 1 week and the normal feeding period was 6 weeks. The breast muscle tissues were collected for transcriptome sequencing, and the sequencing data were subjected for differential expression analysis, such as GO function and KEGG pathway enrichment analysis of differentially expressed genes. Differentially expressed genes related to breast muscle lipid metabolism were screened out, and qRT-PCR was used to verify differentially expressed genes. The results showed that a total of 1 065 differentially expressed genes were obtained, of which 703 were up-regulated genes and 362 were down-regulated genes. GO enrichment results show that differentially expressed genes are concentrated in cellular processes, single-biological processes, biological regulation and metabolic processes in biological processes. Enrichment analysis of KEGG signaling pathway shows that differentially expressed genes were significantly enriched in focal adhesion, unsaturated fatty acid biosynthesis, fatty acid biosynthesis, and steroid biosynthesis. Totally 11 candidate genes were found mainly related to intramuscular fat metabolism, including FADS1, FADS2, ELOVL5, ACOX2, SLC27A1, FABP5, LPL, LOC107050163, ENSGALG00000030996, ENSGALG00000005043 and ENSGALG00000048882. Six genes were randomly selected for qRT-PCR verification, and their relative expression changes were consistent with the sequencing results. This study screened the differentially expressed genes related to CLA affecting breast muscle lipid metabolism in Royal chickens, and analyzed 11 genes related to fat metabolism, laying the foundation for revealing the molecular mechanism of CLA regulating intramuscular fat deposition.

Oferta de pasto kikuyo (Pennisetum clandestinum), tercio de lactancia y perfil de ácidos grasos lácteos / Kikuyo grass (Pennisetum clandestinum) allowance, state of lactation and milk fatty acid profile

Objetivo. Evaluar el efecto de la oferta de kikuyo y el tercio de lactancia sobre el perfil de ácidos grasos en la grasa láctea de bovinos en pastoreo. Materiales y métodos. Se utilizaron 18 vacas de la raza Holstein con un peso promedio de 585 ±10 kg entre dos y cuatro partos, en primer y segundo tercio de lactancia. Las vacas se dividieron en tres grupos y fueron asignados al azar a uno de los tres tratamientos (ofertas de 2.6; 3.3 ó 4.0 kg MS/100 kg PV). Se determinó el perfil de ácidos grasos en la leche los días 14 y 21 del periodo experimental. Resultados. Los ácidos grasos C6:0, C16:0, C18:1c9 y C18:3 permanecieron constantes entre las diferentes ofertas de forraje y tercios de lactancia. En las mayores ofertas se presentó un aumento entre el día 14 y 21 de los ácidos C10:0 y C12:0 mientras que disminuyeron su concentración en estos mismos días los ácidos C18:1t11, C18:2c9c12, C18:2c9t11 y poliinsaturados. Se presentó una mayor concentración del ALC en animales de segundo tercio respecto a los de primero. Conclusiones. Debido a las variaciones entre los días de muestreo en el perfil de ácidos grasos de la grasa láctea fue imposible determinar si el aumento en la oferta mejora las concentraciones de ácidos grasos que han presentado efecto benéfico en la salud humana. La movilización de reservas de grasa podría explicar el comportamiento diferente de la concentración de ácidos grasos entre los días de recolección de muestras.

Objective. To evaluate the effect of kikuyu offer and stage of lactation on fatty acids profile on milk fat of grazing dairy bovines. Materials and methods. Eighteen Holstein cows with average weight of 585±10 Kg in two to four calvings on first and second lactation stages. Cows were divided in three groups and assigned randomly to one of three treatments (pasture allowances of 2.6, 3.3 or 4.0 KgDM/100 Kg LW). Milk fatty acid profiles were determined on days 14 and 21 of the experimental period. Results. Fatty acids C6:0, C16:0, C18:1cis9, C18:3 remained constant between different forage allowances and lactation stage were used. On the treatments of highest allowance, there was an increase between days 14 and 21 of C10:0 andC12:0 acids while C18:1t11,C18:2c9c12, C18:2c9,t11, and polyunsaturated fatty acids decreased their concentration. The lowest allowance had a different behavior. A higher concentration of ALC was observed in animals of second stage compared to first stage of lactation. Conclusions. It was not possible to conclude on the effects of forage allowance on the fatty acid profile of milk, due to variations between sampling dates. It is possible that mobilization of fat storage can explain the different behavior of fatty acid concentrations between sampling days.

Ácido linoleico conjugado (ALC), metabolismo de lípidos y enfermedad cardiovascular / Conjugated linoleic acid (ALC), lipid metabolism and cardiovascular disease

High density lipoproteins (HDL) have been inversely related with the risk of cardiovascular diseases and are considered antiatherogenic factors. The vascular protective effect of HDL is associated to the reverse cholesterol transport, where the sterol is mobilized from peripheral tissues to the liver by HDL and redistributed to circulation or delivered through the bile as free cholesterol or transformed into bile acids. In the last years it has been demonstrated that conjugated linoleic acid (CLA), an omega-6 fatty acid from ruminants, which is a mixture of positional and geometric isomers of linoleic acid, has hipolipidemic and antiatherogenic properties in animal models. However, the precise effect of CLA on HDL metabolism and the mechanisms involved in these actions have yet not been elucidated. The present work reviews the scientific literature about the possible role of CLA as an antiatherogenic factor by controlling the reverse cholesterol transport.

Las lipoproteínas de alta densidad (HDL) han sido correlacionadas inversamente con el riesgo de enfermedad cardiovascular ya que se considera que constituyen un factor de protección antiateroesclerótico. El efecto protector vascular de las HDL se asocia con la vía de transporte reverso de colesterol, proceso por el cual el esterol es movilizado desde los tejidos periféricos hacia el hígado a través de las HDL plasmáticas para ser redistribuido a la circulación, o para su remoción hacia la bilis como colesterol propiamente tal o transformado en sales biliares. Por otro lado, en los últimos a±os el ácido linoleico conjugado (ALC), un acido graso derivado de la serie omega-6 proveniente de animales rumiantes y cuya mezcla está mayoritariamente formada por los isómeros geométricos y posicionales del ácido linoleico (cis 9 trans 11 y trans 10 cis 12), ha demostrado tener propiedades hipolipemiantes y antiaterogénicas en varios modelos animales. Sin embargo, su efecto preciso sobre el metabolismo de HDL y los posibles mecanismos de acción involucrados aún no ha sido dilucidado. El presente trabajo realiza una revisión de la literatura científica en relación al rol antiaterosclerótico que puede tener el consumo de ALC a través del control del trasporte reverso del colesterol.

Isomer specificity of conjugated linoleic acid (CLA): 9E,11E-CLA

Conjugated linoleic acids (CLA) were identified in 1980's, since then it has been intensively studied due to its various beneficial health effects such as anti-inflammatory, anti-atherogenic, anti-carcinogenic and anti-diabetic/obesity effects. Isomer specificity of a number of CLA isomers, especially predominant isomer 9Z,11E- and 10E,12Z-CLA, is now recognized. However, the less prevalent CLA isomers have not been well characterized. Recently, studies have reported the distinctively different effects of 9E,11E-CLA in colon cancer cells, endothelial cells, and macrophage cells compared to the rest of CLA isomers. In this review, various effects of CLAs, especially anti-inflammatory and anti-atherogenic effects, will be discussed with focusing on the isomer-specific effects and potential mechanism of action of CLA. At last, recent studies about 9E,11E-CLA in in vitro and animal models will be discussed.

Effect of CLA (Conjugated Linoleic Acid) on the Anti-Atherosclerotic Factors in Human Hepatoma HepG2 Cells

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA), which is found abundantly in dairy products and meats. This study was performed to investigate the anticarcinogenic effect of CLA in HepG2 hepatoma cells. HepG2 cell were treated with LA and CLA at the various concentrations of 10, 20, 40, 80 uM each at different incubation times. After each incubation times, cell proliferation, fatty acids incorporation into cell, peroxidation and postaglandin E2 (PGE2) and thromboxane A2 (TXA2) for the eicosanoid metabolism were measured. LA treated HepG2 cells were increased cell growth 6 - 70% of control whereas CLA increased cell death the half of those in LA group (p < 0.001). LA and CLA were incorporated very well into the cellular membranes four times higher than in control according to concentration and longer incubation times. Moreover, LA synthesized significantly arachidonic acids corresponding with LA concentration compared to CLA supplementation. The supplementation with LA increased intracellular lipid peroxides concentration corresponding with LA concentration and five times higher than those in CLA significantly at any incubation times (p < 0.001). PGE2 and TXA2 levels were three to twenty times lower in condition of CLA treatments than LA, respectively. Overall, the dietary CLA might change the HepG2 cell growth by the changes of cell composition, production of lipid peroxide. Since CLA have not changed the levels of arachidonic acid of cell membrane, which was sources of eicosanoids, eicosanoid synthesis was not increased in CLA compared to LA. Our results was suggest CLA has a possibility to protect the progress of atherosclerosis because CLA does not produce lipid production and endothelial contraction factors in liver.

Effects of Conjugated Linoleic Acid (CLA) on Matrix Metalloproteinase (MMP) Activity and Cell Motility in Human Colon Cancer Cell Lines

Conjugated linoleic acid (CLA) consists of several geometric isomers of linoleic acid. CLA is found in foods derived from ruminants and exhibits strong anticarcinogenic effects in a variety of animal models. Matrix metalloproteinases (MMPs) play a key role in cancer progression. Specifically, MMP-2 and -9, which hydrolyze the basal membrane type IV collagen, are involved in the initial breakdown of collagen and basement membrane components during tumor growth and invasion. However, the effects of CLA on cancer cell motility and MMP expression and activity are not currently well known. Therefore, the present study examined whether CLA reduces the activity of MMP and cell motility in SW480 and SW620 cells, the human colon cancer cell lines. Gelatin zymography and Western blot analysis revealed that phorbol 12-myristate 13-acetate (PMA) induced the activity and protein expression of Mr 92,000 MMP-9 in both cell lines. To examine whether CLA inhibits the MMP activity, cells were incubated with 100 ngfmL PMA in the presence of various concentrations of CLA. PMA-induced MMP-9 activity was decreased by 20 micrometer CLA in SW480 cells, and by 10 micrometer and 20 micrometer CLA in SW620 cells. Results from the Hoyden chamber assay showed that cell motility was increased by PMA and that PMA-induced cell motility was significantly decreased by 20 micrometer CLA in SW480 cells. These results indicate that CLA may reduce the motility and MMP activity in human colon cancer cells.

EFFECT OF FORTIFIED CONJUGATED LINOLEIC ACID MILK ON BODY FAT AND PLASMA LIPIDS IN MICE / 营养学报

Objective: To study the effects of fortified conjugated linoleic acid (CLA) milk on body fat and plasma lipids in mice.Method:Forty male Kunming mice of 4 w old were randomly divided into four groups and fed diet and milk supplemented with 0%,0.1%,0.5%,1.0% CLA (percent of diet, dry mass) respectively for 4 w.Weight gain,body fat,intra-abdominal fat,feed conversion efficiency and plasma TG, TC, HDL , LPL were measured.Results:At the end of the experiment, all these physiological indices were decreased with increasing CLA in the milk and were lower significantly than that of control group when supplemented with 0.5% CLA in milk. TG , TC and (TC- HDL) / HDL were decreased, but HDL and LPL were increased with increasing CLA amount in the milk. TG,HDL,LPL and (TC- HDL)/ HDL were best when fed the milk supplemented with 1.0% CLA,while TC was the lowest when fed the milk supplemented with 0.5% CLA . Conclusion:The fortified conjugated linoleic acid is effective in lowering body fat and blood lipids.