Linoleic Acid Supplementation Research Articles

Influence of linoleic acid supplementation on the quality of frozen-thawed ram semen

Influence of linoleic acid supplementation on the quality of frozen-thawed ram semen

Physiological response of Metarhizium rileyi with linoleic acid supplementation

Metarhizium rileyi has a broad biocontrol spectrum but is highly sensitive to abiotic factors. A Colombian isolate M. rileyi Nm017 has shown notorious potential against Helicoverpa zea. However, it has a loss of up to 22% of its conidial germination after drying, which limits its potential as a biocontrol agent and further commercialization. Conidial desiccation resistance can be enhanced by nutritional supplements, which promotes field adaptability and facilitates technological development as a biopesticide. In this study, the effect of culture medium supplemented with linoleic acid on desiccation tolerance in Nm017 conidia was evaluated. Results showed that using a 2% linoleic acid-supplemented medium increased the relative germination after drying by 41% compared to the control treatment, without affecting insecticidal activity on H. zea. Also, the fungus increased the synthesis of trehalose, glucose, and erythritol during drying, independently of linoleic acid use. Ultrastructural analyses of the cell wall-membrane showed a loss of thickness by 22% and 25%, in samples obtained from 2% linoleic acid supplementation and the control, respectively. Regarding its morphological characteristics, conidia inner area from both treatments did not change after drying. However, conidia from the control had a 24% decrease in length/width ratio, whereas there was no alteration in conidia from acid linoleic. The average value of dry conidia elasticity coefficient from linoleic acid treatment was 200% above the control. Medium supplementation with linoleic acid is a promising fermentation strategy for obtaining more tolerant conidia without affecting production and biocontrol parameters, compatible solutes synthesis, or modifying its cell configuration.

Linoleic Acid Supplementation Attenuates Inflammation and Redox Imbalance During Aging in Wistar Rats

Linoleic Acid Supplementation Attenuates Inflammation and Redox Imbalance During Aging in Wistar Rats

Temporal Effects of Safflower Oil Diet-based Linoleic Acid Supplementation on Barth Syndrome Cardiomyopathy

Background: Barth syndrome (BTHS) is an X-linked mitochondrial lipid disorder caused by mutations in TAFAZZIN ( TAZ). Cardiomyopathy is a major clinical feature in BTHS. Thus far, there is no curative therapy for BTHS. TAZ is an acyltransferase required for remodeling/maturation of cardiolipin (CL), a signature phospholipid of mitochondria. TAZ deficiency causes ineffcient transacylation and maturation of CL. In mammalian heart, the major mature CL species is tetralinoleoyl-CL, containing four linoleic acid (LA) side chains. LA is one of two essential fatty acids that must be obtained through diet. In this study, focus on the investigation of potential therapeutic effects of a safflower oil diet-based LA supplementation on BTHS cardiomyopathy. Hypothesis: Linoleic acid (LA) supplementation could ameliorate BTHS by increasing incorporation of linoleoyl groups into nascent CL towards mature CL composition without requiring the remodeling process. Methods: Taz global (gKO) and cardiomyocyte-specific knockout (cKO) mouse models were fed with high-LA safflower oil diet (LAD) contained 10% LA (LA weight/chow weight; law/cw) and the low-LA palm oil control diet (CD) contained 1% LA (law/cw). Echocardiographic analysis was performed for cardiac function over a full-time course. Lipidomic analysis was performed to determine CL profiles in mutant hearts. Results: Our results clearly revealed that dietary LA supplementation fully prevented cardiomyopathy in Taz gKO and cKO mutants at 4 months of age, with cardiac function of mutants in the LAD group being comparable to that of WT controls, while mutants in the CD group displayed significant dilated cardiomyopathy (DCM) at this age. The beneficial effects of LA supplementation extended to, albeit with diminishing effcacy, at 6 and 8 months of age. In lipidomic analysis, we observed “BTHS-like” CL profiles in Taz cKO hearts both in LAD and CD groups. However, LAD ameliorated the severity of CL abnormalities in Taz cKO hearts. Interesting, beneficial effects of LAD on CL profiles declined at 8 months of age. Conclusion: Our study demonstrated that dietary LA supplementation has potential to delay development of BTHS cardiomyopathy at early stages, but there is a declining effectiveness as the disease progresses, providing important insights into the temporal effects of LA in BTHS therapy. Xi Fang is supported by NIH grants. Sylvia M Evans is supported by NIH grants and the Foundation Leducq (16 CVD 03). Asa B Gustafsson is supported by NIH grants R01HL155281 and R01HL157265. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dietary linoleic acid supplementation fails to rescue established cardiomyopathy in Barth syndrome

Barth syndrome (BTHS) is a mitochondrial lipid disorder caused by mutations in TAFAZZIN (TAZ), required for cardiolipin (CL) remodeling. Cardiomyopathy is a major clinical feature, with no curative therapy. Linoleic acid (LA) supplementation is proposed to ameliorate BTHS cardiomyopathy by enhancing linoleoyl group incorporation into CL. While the beneficial effect of dietary LA supplementation in delaying the development of BTHS cardiomyopathy has been recently tested, its potential to reverse established BTHS cardiomyopathy remains unclear. Our study revealed that LA supplementation cannot rescue established BTHS cardiomyopathy in mice, highlighting the importance of early initiation of LA supplementation for maximum benefits.

Dietary linoleic acid supplementation protects against obesity-induced microglial reactivity in mice

We investigated whether linoleic acid (LA) supplementation could modulate emotional behavior and microglia-related neuroinflammation. For that, male mice of C57BL/6J genetic background fed either a high-fat diet (HFD) or a standard diet (STD) for 12 weeks, were treated with a vehicle or LA solution for 5 weeks before being evaluated for emotional behavior using a battery of behavioral tests. The animals were subsequently sacrificed and their brains collected and processed for immunofluorescence staining, targeting microglia-specific calcium-binding proteins (IBA-1). Neuroinflammation severity was assessed in multiple hypothalamic, cortical and subcortical brain regions. We show an anxio-depressive-like effect of sustained HFD feeding that was neither alleviated nor worsened with LA supplementation. However, increased IBA-1 expression and microgliosis in the HFD group were largely attenuated by LA supplementation. These observations demonstrate that the anti-neuroinflammatory properties of LA are not restricted to hypothalamic areas but are also evident at the cortical and subcortical levels. This study discloses that neuroinflammation plays a role in the genesis of neuropsychiatric disorders in the context of obesity, and that LA supplementation is a useful dietary strategy to alleviate the impact of obesity-related neuroinflammation.

The Effects of Conjugated Linoleic Acid Supplements on Biomarkers of Oxidative Stress in Human Studies: A Systematic Review and Meta-Analysis

Background: Oxidative stress is the leading cause of chronic disorders. The aim of the present study is to assess the effects of conjugated linoleic acid (CLA) supplements on oxidative stress biomarkers in adults.
 Methods: PubMed, Web of Science, Google Scholar, ProQuest, Scopus, and Embase were searched up to December 2020. All clinical trials that evaluated the effect of CLA on malondialdehyde (MDA), GSH-peroxidase (GPX), and 8-IsoprostanesF2α (8-iso-PGF2α) were included.
 Results: Twelve eligible studies were included in the meta-analysis. A significant increase was observed in 8-iso-PGF2α level (SMD=1.48 nmol/mmol of creatinine; 95% CI: 1.11 to 1.85) with low heterogeneity level (I2= 31.5%, and P=0.199). This effect was also significant in both subgroups of healthy and metabolic disorder individuals. Moreover, after Hartung-Knapp adjustment, the results remained significant. No significant changes were found in MDA (SMD=-0.34 µmol/l; 95% CI: -0.82 to 0.14) and GPX (SMD=0.31 U/gHb; 95% CI: -0.03 to 0.66) levels. However, after Hartung-Knapp adjustment, the results became significant for GPX level (SMD=0.31, 95% CI: 0.04 to 0.59).
 Conclusion: CLA supplementation could significantly increase some markers of oxidative stress such as 8-iso-PGF2α level and GPX level, without any significant effect on MDA level.

Conjugated linoleic acid and glucosamine supplements may prevent bone loss in aging by regulating the RANKL/RANK/OPG pathway.

The skeleton is a living organ that undergoes constant changes, including bone formation and resorption. It is affected by various diseases, such as osteoporosis, osteopenia, and osteomalacia. Nowadays, several methods are applied to protect bone health, including the use of hormonal and non-hormonal medications and supplements. However, certain drugs like glucocorticoids, thiazolidinediones, heparin, anticonvulsants, chemotherapy, and proton pump inhibitors can endanger bone health and cause bone loss. New studies are exploring the use of supplements, such as conjugated linoleic acid (CLA) and glucosamine, with fewer side effects during treatment. Various mechanisms have been proposed for the effects of CLA and glucosamine on bone structure, both direct and indirect. One mechanism that deserves special attention is the regulatory effect of RANKL/RANK/OPG on bone turnover. The RANKL/RANK/OPG pathway is considered a motive for osteoclast maturation and bone resorption. The cytokine system, consisting of the receptor activator of the nuclear factor (NF)-kB ligand (RANKL), its receptor RANK, and its decoy receptor, osteoprotegerin (OPG), plays a vital role in bone turnover. Over the past few years, researchers have observed the impact of CLA and glucosamine on the RANKL/RANK/OPG mechanism of bone turnover. However, no comprehensive study has been published on these supplements and their mechanism. To address this gap in knowledge, we have critically reviewed their potential effects. This review aims to assist in developing efficient treatment strategies and focusing future studies on these supplements.

The effects of conjugated linoleic acid supplementation on anthropometrics and body composition indices in adults: a systematic review and dose-response meta-analysis.

Prior meta-analytic investigations over a decade ago rather inconclusively indicated that conjugated linoleic acid (CLA) supplementation could improve anthropometric and body composition indices in the general adult population. More recent investigations have emerged, and an up-to-date systematic review and meta-analysis on this topic must be improved. Therefore, this investigation provides a comprehensive systematic review and meta-analysis of randomised controlled trials (RCT) on the impact of CLA supplementation on anthropometric and body composition (body mass (BM), BMI, waist circumference (WC), fat mass (FM), body fat percentage (BFP) and fat-free mass (FFM)) markers in adults. Online databases search, including PubMed, Scopus, the Cochrane Library and Web of Science up to March 2022, were utilised to retrieve RCT examining the effect of CLA supplementation on anthropometric and body composition markers in adults. Meta-analysis was carried out using a random-effects model. The I2 index was used as an index of statistical heterogeneity of RCT. Among the initial 8351 studies identified from electronic databases search, seventy RCT with ninety-six effect sizes involving 4159 participants were included for data analyses. The results of random-effects modelling demonstrated that CLA supplementation significantly reduced BM (weighted mean difference (WMD): -0·35, 95 % CI (-0·54, -0·15), P < 0·001), BMI (WMD: -0·15, 95 % CI (-0·24, -0·06), P = 0·001), WC (WMD: -0·62, 95% CI (-1·04, -0·20), P = 0·004), FM (WMD: -0·44, 95 % CI (-0·66, -0·23), P < 0·001), BFP (WMD: -0·77 %, 95 % CI (-1·09, -0·45), P < 0·001) and increased FFM (WMD: 0·27, 95 % CI (0·09, 0·45), P = 0·003). The high-quality subgroup showed that CLA supplementation fails to change FM and BFP. However, according to high-quality studies, CLA intake resulted in small but significant increases in FFM and decreases in BM and BMI. This meta-analysis study suggests that CLA supplementation may result in a small but significant improvement in anthropometric and body composition markers in an adult population. However, data from high-quality studies failed to show CLA's body fat-lowering properties. Moreover, it should be noted that the weight-loss properties of CLA were small and may not reach clinical importance.

Effects of Dietary Linoleic Acid on Blood Lipid Profiles: A Systematic Review and Meta-Analysis of 40 Randomized Controlled Trials.

Th aim of this meta-analysis was to elucidate whether dietary linoleic acid (LA) supplementation affected blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), compared with other fatty acids. Embase, PubMed, Web of Science and the Cochrane Library databases, updated to December 2022, were searched. The present study employed weighted mean difference (WMD) and a 95% confidence interval (CI) to examine the efficacy of the intervention. Out of the 3700 studies identified, a total of 40 randomized controlled trials (RCTs), comprising 2175 participants, met the eligibility criteria. Compared with the control group, the dietary intake of LA significantly decreased the concentrations of LDL-C (WMD: -3.26 mg/dL, 95% CI: -5.78, -0.74, I2 = 68.8%, p = 0.01), and HDL-C (WMD: -0.64 mg/dL, 95% CI: -1.23, -0.06, I2 = 30.3%, p = 0.03). There was no significant change in the TG and TC concentrations. Subgroup analysis showed that the LA intake was significantly reduced in blood lipid profiles compared with saturated fatty acids. The effect of LA on lipids was not found to be dependent on the timing of supplementation. LA supplementation in an excess of 20 g/d could be an effective dose for lowering lipid profiles. The research results provide further evidence that LA intake may play a role in reducing LDL-C and HDL-C, but not TG and TC.

Conjugated linoleic acid supplementation changes prostaglandin concentration ratio and alters the expression of genes involved in maternal-fetal recognition from bovine trophoblast cells in vitro

Early embryonic mortality caused by maternal-fetal recognition failure in the three weeks after fertilization represents a major cause of reproductive inefficiency in the cattle industry. Modifying the amounts and ratios of prostaglandin (PG) F2α and PGE2 can benefit the establishment of pregnancy in cattle. Adding conjugated linoleic acid (CLA) to endometrial and fetal cells culture affects PG synthesis, but its effect on bovine trophoblast cells (CT-1) is unknown. The aim of this study was to determine the effects of CLA (a mixture of cis- and trans-9, 11- and −10,12-octadecadienoic acids) on PGE2 and PGF2α synthesis and the expression of transcripts involved with maternal-fetal recognition of bovine trophectoderm. Cultures of CT-1 were exposed to CLA for 24, 48 and 72 h. Transcript abundance was determined by qRT-PCR and hormone profiles were quantified by ELISA. The PGE2 and PGF2α concentrations were reduced in the culture medium of CLA-exposed CT-1 compared to that of unexposed cells. Furthermore, CLA supplementation increased the PGE2:PGF2α ratio in CT-1 and had a quadratic effect (P < 0.05) on the relative expression of MMP9, PTGES2, and PTGER4. The relative expression levels of PTGER4 were reduced (P < 0.05) in CT-1 cultured with 100 μM CLA than in the unsupplemented and 10 μM-CLA groups. Treatment of CT-1 with CLA decreased PGE2 and PGF2α synthesis but a biphasic effect of CLA was observed on the PGE2:PGF2α ratio and relative abundance of transcripts with 10 μM CLA providing maximal improvements in each endpoint. Our data suggest that CLA may influence eicosanoid metabolic process and extracellular matrix remodeling.

Linoleic acid improves PIEZO2 dysfunction in a mouse model of Angelman Syndrome

Angelman syndrome (AS) is a neurogenetic disorder characterized by intellectual disability and atypical behaviors. AS results from loss of expression of the E3 ubiquitin-protein ligase UBE3A from the maternal allele in neurons. Individuals with AS display impaired coordination, poor balance, and gait ataxia. PIEZO2 is a mechanosensitive ion channel essential for coordination and balance. Here, we report that PIEZO2 activity is reduced in Ube3a deficient male and female mouse sensory neurons, a human Merkel cell carcinoma cell line and female human iPSC-derived sensory neurons with UBE3A knock-down, and de-identified stem cell-derived neurons from individuals with AS. We find that loss of UBE3A decreases actin filaments and reduces PIEZO2 expression and function. A linoleic acid (LA)-enriched diet increases PIEZO2 activity, mechano-excitability, and improves gait in male AS mice. Finally, LA supplementation increases PIEZO2 function in stem cell-derived neurons from individuals with AS. We propose a mechanism whereby loss of UBE3A expression reduces PIEZO2 function and identified a fatty acid that enhances channel activity and ameliorates AS-associated mechano-sensory deficits.

Some Aspects of Neonatal Essential Fatty Acid Status are Altered by Linoleic Acid Supplementation of Women during Pregnancy

To study the effect of maternal linoleic acid [18:2(n-6), LA] supplementation during pregnancy on neonatal essential fatty acid status, pregnant women with relatively low plasma linoleic acid concentrations before 16 wk of gestation (n = 21) were supplied with foods rich in linoleic acid, resulting in an additional intake of 10 g/d of linoleic acid from the 20th week of gestation until delivery. One of the two control groups consisted of pregnant women with comparably low plasma linoleic acid concentrations at the start of the study (LL-control group, n = 22); the other consisted of women with habitually high plasma linoleic acid concentrations (HL-control group, n = 21). The neonatal essential fatty acid status was assessed by determining the fatty acid composition of phospholipids (PL) isolated from umbilical plasma and umbilical vessel walls. The maternal linoleic acid status in the LA-supplemented group increased to a level comparable to that of the HL-control group, but the neonatal linoleic acid status did not differ from that of either control group. Linoleic acid supplementation did result in slightly, but significantly, higher total amounts of (n-6) long-chain polyenes in umbilical plasma and vein vessel wall phospholipids compared with the LL-control group. This increase was associated with significantly lower total amounts of (n-3) long-chain polyenes. In the HL-control group, the concentration of (n-3) long-chain polyenes in umbilical plasma and vessel walls was significantly lower than in the LA-supplemented and the LL-control group. The results of this study indicate that maternal linoleic acid supplementation can affect some aspects of neonatal essential fatty acid status.

The effects of conjugated linoleic acid supplementation on inflammatory cytokines and adipokines in adults: A GRADE-assessed systematic review and dose-response meta-analysis.

Many studies have investigated the effect of conjugated linoleic acid (CLA) supplementation on inflammatory cytokines and adipokines. However, the results of these studies are not consistent. Therefore, this systematic review and meta-analysis were designed to comprehensively evaluate the effect of CLA supplementation on inflammatory cytokines and adipokines. Randomized controlled trials (RCTs) examining the effects of CLA supplementation on C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), adiponectin, and leptin, published up to March 2022, were identified through PubMed, SCOPUS, and ISI Web of Science databases. A random-effects model was used to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI) for 42 studies that included 1,109 participants. Findings from 42 studies with 58 arms indicated that CLA supplementation significantly decreased IL-6 and TNF-α levels and also slightly increased CRP levels. However, adiponectin and leptin levels did not change after CLA supplementation. A subgroup analysis found that CLA supplementation reduced adiponectin and leptin in women. Our results demonstrated that CLA supplementation increased CRP levels and decreased TNF-α and IL-6 levels. Therefore, it seems that CLA can have both proinflammatory and anti-inflammatory roles. https://www.crd.york.ac.uk/prospero/, identifier (CRD42022331110).

Heterologous Production of Calendic Acid Naturally Found in Calendula officinalis by Recombinant Fission Yeast.

Calendic acid (CA) is a conjugated fatty acid with anti-cancer properties that is widely present in seed oil of Calendula officinalis. Using the co-expression of C. officinalis fatty acid conjugases (CoFADX-1 or CoFADX-2) and Punica granatum fatty acid desaturase (PgFAD2), we metabolically engineered the synthesis of CA in the yeast Schizosaccharomyces pombe without the need for linoleic acid (LA) supplementation. The highest CA titer and achieved accumulation were 4.4 mg/L and 3.7 mg/g of DCW in PgFAD2 + CoFADX-2 recombinant strain cultivated at 16 °C for 72 h, respectively. Further analyses revealed the accumulation of CA in free fatty acids (FFA) and downregulation of the lcf1 gene encoding long-chain fatty acyl-CoA synthetase. The developed recombinant yeast system represents an important tool for the future identification of the essential components of the channeling machinery to produce CA as a high-value conjugated fatty acid at an industrial level.

Linoleic acid ameliorates intestinal mucosal barrier injury in early weaned pigeon squabs (Columba livia).

The study aimed to investigate whether linoleic acid could improve the intestinal barrier function of squabs under weaning stress conditions. Totally 320 7-d-old weaned squabs were randomly divided into four treatment groups, including control group (CON), 0.7% linoleic acid addition group (LA007), 1.4% linoleic acid addition group (LA014) and 2.1% linoleic acid addition group (LA021). At 21 d, eight squabs were randomly selected from each treatment group for sampling and determination. The results showed that adding linoleic acid could improve (P < 0.05) the body weight of weaned squabs, and LA014 had the best effect. With the increase of linoleic acid dosage, villi height and villi area increased linearly or quadratically (P < 0.05), and reached the maximum in LA021 or LA014, respectively. The linoleic acid supplementation could improve the intestinal tight junction of weaned squabs, and the LA014 was the most significant (P < 0.05). With the linoleic acid increasing, the levels of intestinal IL-6 and TNF-α decreased linearly (P < 0.05), while intestinal IL-10 increased quadratically (P < 0.05) and reached the maximum in LA014. Serum endotoxin and diamine oxidase levels decreased linearly (P < 0.05) and reached the lowest level in LA014. The ultrastructure of villi revealed that the length of ileal microvilli in LA014 was significantly increased (P < 0.05) and the microvilli became dense, and the mitochondria in epithelial cells returned to normal state. Further exploring the mechanism of linoleic acid alleviating intestinal injury caused by weaning stress in squabs, it was found that linoleic acid down-regulated (P < 0.05) the relative protein expression of TLR4, MyD88, phosphorylated JNK, and phosphorylated p38, reducing secretion of pro-inflammatory factors IL-6 and TNF-α. This study indicated that linoleic acid could alleviate intestinal barrier injury of early weaned squabs by down-regulating TLR4-MyD88-JNK/p38-IL6/TNF-α pathway.

Effect of conjugated linoleic acid (CLA) supplementation on dry matter intake, metabolisable energy intake and changes in bodyweight of crossbred cows during transition period

Effect of conjugated linoleic acid (CLA) supplementation on dry matter intake, metabolisable energy intake and changes in bodyweight of crossbred cows during transition period

Effects of dietary n-6 polyunsaturated fatty acids (PUFA) composition on growth performances and non-specific immunity in pacific white shrimp (Litopenaeus vannamei)

This study was aimed to investigate the effects of dietary arachidonic acid (ARA) and linoleic acid (LA) on growth, fatty acid composition, antioxidant capacity and immunity of Litopenaeus vannamei. Eight diets were prepared with different LA or ARA content and approximately equal amounts of α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), including a control diet (CK0) without ARA and LA supplementation. 720 shrimp were fed above diets in triplicate for 56 days. The results showed that, the specific growth rate (SGR) and weight gain (WG) of shrimp fed the experimental diets were significantly enhanced compared to the control group. In general, the content of LA or ARA in the experimental shrimp tissues closely mirrored their respective dietary fatty acid levels. The expressions of delta 6 fatty acid desaturase (Δ6FAD) and fatty acid elongase 5 (Elovl5) genes in the intestine and hepatopancreas increased significantly with increasing dietary LA from 5.3 to 9.5, or ARA from 0.2 to 11.1 g kg−1. The activities of superoxide dismutase (SOD) and catalase (CAT), and content of malondialdehyde (MDA) decreased with increasing dietary LA from 5.3 to 9.5, or ARA from 0.2 to 3.8 g kg−1, then increased as dietary LA increased to 16.2, or ARA increased to 11.1 g kg−1. The activities of lysozyme (LZM), acid phosphatase (ACP) and alkine phosphatase (AKP) increased accordingly with the increase of dietary LA from 5.3 to 9.5 or ARA from 0.2 to 1.9 g kg−1. SOD and CAT gene expressions were opposite to the enzyme activity in ARA groups. The results suggested that appropriate dietary LA (9.5 g kg−1) or ARA (3.8 g kg−1) had positively effects on growth, EPA biosynthesis, antioxidant ability and immunity of L. vannamei.

Lipolysis-derived linoleic acid drives beige fat progenitor cell proliferation.

De novo beige adipocyte biogenesis involves the proliferation of progenitor cells in white adipose tissue (WAT); however, what regulates this process remains unclear. Here, we report that in mouse models but also in human tissues, WAT lipolysis-derived linoleic acid triggers beige progenitor cell proliferation following cold acclimation, β3-adrenoceptor activation, and burn injury. A subset of adipocyte progenitors, as marked by cell surface markers PDGFRα or Sca1 and CD81, harbored cristae-rich mitochondria and actively imported linoleic acid via a fatty acid transporter CD36. Linoleic acid not only was oxidized as fuel in the mitochondria but also was utilized for the synthesis of arachidonic acid-derived signaling entities such as prostaglandin D2. Oral supplementation of linoleic acid was sufficient to stimulate beige progenitor cell proliferation, even under thermoneutral conditions, in a CD36-dependent manner. Together, this study provides mechanistic insights into how diverse pathophysiological stimuli, such as cold and burn injury, promote de novo beige fat biogenesis.

Size, numberand phospholipid composition of milk fat globules are affected by dietary conjugated linoleic acid.

Milk fat globules (MFGs) surround the triacylglycerol core that composes milk fat. The aim of this study isto induce milk fat depression via dietary conjugated linoleic acid (CLA) supplementation to study MFG size parameters, numberand glycerophospholipid composition. Eighteen Holstein dairy cows (136 ± 28 days in milk, 571 ± 37.9 kg body weight, 27.6 ± 2.1 kg milk/day) were selected and randomly assigned to a control or CLA group for a 14-dayperiod. Cows were fed a basal diet (control, n = 8) or the control plus 400 g/day CLA (C18:2 cis-9, trans-11 38.1% and C18:2 trans-10, cis-12 36.8%) (n = 10) for 7 days after which the CLA group was switched to the basal diet for another 7 days along with the control group. Cow performance, milk composition, MFG size and numbers were measured daily. On the seventh day after the start of the experiment, milk samples were identified and the quantification of glycerophospholipid compounds, and RNA were isolated from milk fat samples for a real-time polymerase chain reaction. Compared with control, at Day 7 from the start of feeding, supplemental CLA did not affect milk production (28.09vs. 28.50 kg/day), dry matter intake (14.9vs. 15.4 kg/day), or milk protein (3.55/100vs. 3.70 g/100 ml) and lactose contents (5.11/100vs. 5.17 g/100 ml). However, although the specific surface area of MFG (2138vs. 1815 m²/kg) was greater, CLA reduced milk fat content (1.95/100vs 3.64 g/100 ml on Day 7) and particle size parameters of MFG. The number of MFG gradually decreased until Day 7 of feeding, and then increased by Day 14 (2.96 × 109 on Day 1, 1.63 × 109 on Day 7 and 2.28 × 109 on Day 14) in the CLA group. Compared with control, glycerophospholipid analysis revealed that concentrations of phosphatidylcholine (PC) (e.g., PC [16:0/18:1] 20322vs. 29793 nmol/L), lysophosphatidylethanolamine (LPE) (e.g., LPE [18:1] 956vs. 4610 nmol/L)and phosphatidylethanolamine (PE) (e.g., PE [16:0/18:1] 7000 vs. 9769 nmol/L) in milk lipids decreased during CLA feeding. In contrast, concentrations of phosphatidylinositol (PI) (e.g., PI [18:0/18:1] 4052vs. 1799 nmol/L) and phosphatidylserine (PS) (e.g., PS [18:1/18:2] 9500 vs. 6843 nmol/L) increased. The messenger RNA abundance of fatty acid synthase, diacylglycerol O-acyltransferase 1, glycerol-3-phosphate acyltransferase 4and phosphate cytidylyltransferase 1, choline, alpha (PCYT1A) were downregulated in the CLA group, confirming published data demonstrating a negative effect of CLA on lipogenesis in the mammary gland. Overall, these results provided evidence for the important role of lipogenic gene expression in the regulation of MFG size, number and glycerophospholipid composition.