Transport Of Long-chain Fatty Acids Research Articles

Water intake increases mesenteric lymph flow and the total flux of albumin, long-chain fatty acids, and IL-22 in rats: new concept of absorption in jejunum.

The traditional Japanese health care custom recommends that a suitable volume of water is consumed. However, physiological and immunological mechanisms in support of this practice are unknown. Therefore, we conducted rat and rabbit in vivo experiments to investigate the effects of intragastric administration of distilled water on the jejunal-originated lymph flow and the concentrations and total flux of cells, albumin, long-chain fatty acids, and innate lymphoid cell 3 (ILC-3)-secreted interleukin-22 (IL-22) through mesenteric lymph vessels. The distribution and activity of ILC-3 in rat small intestine by water intake were evaluated using flow cytometry and RT-PCR. The intragastric administration of distilled water caused significant increases in rat mesenteric lymph flow and in the total flux of cells, albumin, long-chain fatty acids, and IL-22 through the lymph vessels. Intravenously injected Evans blue dye was rapidly transported into rabbit mesenteric lymph vessel and cisterna chyli. The distribution of ILC-3 and the expression of IL-22 mRNA were maximal in the lamina propria cells of the rat jejunum. No significant presence of ILC-3 in the lymph was observed in the control and under water intake conditions. In conclusion, the absorbed water in the jejunum is transported through mesenteric lymph vessels. The higher permeability of albumin in the jejunal microcirculation may play key roles in the transport of consumed water and the reservoir and transporter of long-chain fatty acids. Water intake also accelerates the transfer of IL-22 to the mesenteric lymph, which may contribute, in part, to maintaining and promoting the innate immunity in the body. NEW & NOTEWORTHY The higher permeability of albumin-mediated transport of water-soluble substances in mesenteric lymph vessels of the jejunum may have a large impact on the classic concept suggesting that water-soluble small molecules travel to the liver via the portal vein. ILC-3 is mainly housed in the lamina propria of the jejunum, especially its upper part. IL-22 released from the ILC-3 is also transported through mesenteric lymph in collaboration with the albumin-mediated movement of consumed water.

Chicken I-FABP as biomarker of chicken intestinal lesion caused by coccidiosis

Coccidiosis is an infection of the gastrointestinal tract caused by Eimeria spp, which causes morbidity, mortality, decreased body weight, and decreased production. Until now, difficulties for monitoring health status because no method for early detection has been found. Intestinal - Fatty Acid Binding Proteins (I-FABP) are intracellular proteins that play a role in the transport and metabolism of long-chain fatty acids. The FABP protein family can be used as a marker for specific tissue damage. I-FABP has never been done as a coccidiosis biomarker in poultry. This study aims to know the concentration of I-FABP in serum from chicken blood infected with various doses of Eimeria oocysts. A total of 400-day old chick were divided into four treatment groups: doses of 500 oocysts per ml (D1), 5,000 oocysts per ml (D2) and 50,000 oocysts per ml (D3), and Negative Controls (NC). The parameters used were the number of oocyst, lesion score in chicken intestine and measurement of I-FABP level. The results of this study obtained Eimeria oocyst production began out seven days after infection in the stool. The lesion score began to appear on day five after infection with a dose of 5,000 and 50,000 oocysts per chicken, while I-FABP concentrations were detectable on day 2 (48 hours) after infection. The conclusions of this study I-FABP can be used as biomarkers of early detection of gastrointestinal damage.

Intestinal Saturated Long-Chain Fatty Acid, Glucose and Fructose Transporters and Their Inhibition by Natural Plant Extracts in Caco-2 Cells.

The intestinal absorption of fatty acids, glucose and fructose is part of the basic requirements for the provision of energy in the body. High access of saturated long-chain fatty acids (LCFA), glucose and fructose can facilitate the development of metabolic diseases, particularly the metabolic syndrome and type-2 diabetes mellitus (T2DM). Research has been done to find substances which decelerate or inhibit intestinal resorption of these specific food components. Promising targets are the inhibition of intestinal long-chain fatty acid (FATP2, FATP4), glucose (SGLT1, GLUT2) and fructose (GLUT2, GLUT5) transporters by plant extracts and by pure substances. The largest part of active components in plant extracts belongs to the group of polyphenols. This review summarizes the knowledge about binding sites of named transporters and lists the plant extracts which were tested in Caco-2 cells regarding uptake inhibition.

Dynamics of fatty acid regulatory genes during ovarian development in Penaeus monodon.

The delay in ovarian maturation in farmed black tiger shrimp Penaeus monodon has resulted in the widespread practice of feeding broodstock with the polychaete Perinereis nuntia and their unilateral eyestalk ablation. Although this practice alters fatty acid content in shrimp ovaries and hepatopancreas, its effects on fatty acid regulatory genes are yet to be systematically examined. Here, microarray analysis was performed on hepatopancreas and ovary cDNA collected from P. monodon at different ovarian maturation stages, revealing that 72 and 58 genes in fatty acid regulatory pathways were differentially expressed in hepatopancreas and ovaries respectively. Quantitative real-time PCR analysis revealed that ovarian maturation was associated with higher expression levels of acetyl-CoA acetyltransferase, acyl-CoA dehydrogenase, acyl-CoA oxidase 3 and long-chain fatty acid transport protein 4 in hepatopancreas, whereas the expression levels of 15 fatty acid regulatory genes were increased in shrimp ovaries. To distinguish the effects of different treatments, transcriptional changes were examined in P. monodon with stage 1 ovaries before polychaete feeding, after 1 month of polychaete feeding and after eyestalk ablation. Polychaete feeding resulted in lower expression levels of enoyl-CoA hydratase and acyl-CoA synthetase medium-chain family member 4, while the expression level of phosphatidylinositide phosphatase SAC1 was higher in shrimp hepatopancreas and ovaries. Additionally, eyestalk ablation resulted in a higher expression level of long-chain fatty acid-CoA ligase 4 in both tissues. Together, our findings describe the dynamics of fatty acid regulatory pathways during crustacean ovarian development and provide potential target genes for alternatives to eyestalk ablation in the future.

Metabolic transition of milk triacylglycerol synthesis in response to varying levels of palmitate in porcine mammary epithelial cells

BackgroundMilk in mammals is a key source of lipids for offspring, providing both critical energy and essential fatty acids. For lactating sows, palmitic acid is one of the most abundant fatty acids in milk, providing 10~12% of the suckling pig total dietary energy supply. However, the effects of exogenous palmitic acid on milk fat synthesis in sow mammary glands are not well-known. In this study, we investigated the effects of palmitic acid on lipogenic genes in porcine mammary epithelial cells (pMECs) to explore the role of exogenous palmitic acid in mediating milk triacylglycerols (TAG) synthesis.MethodsPorcine mammary epithelial cells were cultured for 24 h in the presence of different concentrations of palmitate (0, 25, 50, 100, 200, 400, and 600 μM). The effect of palmitate on cell viability was tested via MTT assay. Intracellular lipid accumulation was measured through Oil Red O staining, and TAG levels were quantified by enzymatic colorimetric methods. Expression of genes and proteins involved in milk fat biosynthesis were assayed with quantitative real-time polymerase chain reaction (qPCR) and Western blotting, respectively.ResultsIncubation with palmitate promoted cellular lipid synthesis in a dose-dependent manner, as reflected by the increased TAG content and enhanced formation of cytosolic lipid droplets. The increased lipid synthesis by palmitate was probably attributable to the upregulated mRNA expression of genes associated with milk fat biosynthesis, including long-chain fatty acid uptake (LPL, CD36), intracellular activation and transport (ACSL3, FABP3), TAG synthesis (GPAM, AGPAT6, DGAT1), lipid droplet formation (PLIN2), and regulation of transcription (PPARγ). Western blot analysis of CD36 and DGAT1 proteins confirmed the increased lipid synthesis with increasing incubation of palmitate. However, the genes involved in fatty acid de novo synthesis (ACACA, FASN), fatty acid desaturation (SCD), and regulation of transcription (SREBP1, INSIG1) were inversely affected by incubation with increasing concentrations of palmitate. Western blot analysis of ACACA protein confirmed this decrease associated with increasing levels of palmitate.ConclusionsResults from this study suggest that palmitate stimulated the cytosolic TAG accumulation in pMECs, probably by promoting lipogenic genes and proteins that are involved in lipid synthesis. However, addition of palmitate decreased the fatty acid de novo synthesis in pMECs.

Rapid communication: lipid metabolic gene expression and triacylglycerol accumulation in goat mammary epithelial cells are decreased by inhibition of SREBP-1

In mammals, sterol regulatory element binding protein-1 (SREBP-1) is the master regulator of fatty acid and triacylglycerol synthesis. Recent gene silencing studies in mammary cells indicate that SREBP-1 has a central role in milk fat synthesis. However, SREBP-1 knockdown studies in goat mammary cells have not been performed; hence, its direct role in controlling mRNA expression of lipid metabolism genes and triacylglycerol synthesis remains unknown. Inhibition of SREBP-1 in goat mammary epithelial cells (GMEC) by small interference RNA (siRNA) markedly reduced the content of cellular triacylglycerol (~50% decrease, P < 0.05) and was partly related to downregulation of AGPAT6, LPIN1, and DGAT2 (-23%, -28% and -19%, respectively. P < 0.05), which are key enzymes involved in triacylglycerol synthesis, cellular triacylglycerol content and lipid droplet accumulation all decreased by SREBP-1 inhibition. The expression of lipid droplet formation and secretion genes was not altered in response to treatment. Although the lack of effect on expression of ACACA and FASN (rate-limiting enzymes for de novo fatty acid synthesis) with SREBP-1 knockdown was unexpected (P > 0.05), the downregulation of genes related to synthesis of acetyl-CoA and acetate activation (ACLY, ACSS2, and IDH1, P < 0.05) suggests that lipogenesis was inhibited. SREBP-1 knockdown also resulted in decreased expression of genes associated with fatty acid desaturation and elongation (SCD1 and ELOVL6, P < 0.05), long-chain fatty acid (LCFA) activation and transport (ACSL1, FABP3, and SLC27A6, P < 0.05). The results underscored the essential role of SREBP-1 not only in fatty acid synthesis but also in desaturation, elongation, and esterification in GMEC. Clearly, the lack of effect on ACACA and FASN, both of which are considered the key lipogenic enzymes, implies that there may be different regulatory mechanisms in goat compared with bovine mammary cells.

Anesthetic Management of a Patient With Carnitine-Acylcarnitine Translocase Deficiency

Carnitine-acylcarnitine translocase (CACT) deficiency is a rare disorder of mitochondrial fatty acid metabolism that results in an acute encephalopathic and/or myopathic disorder. Carnitine and CACT play an essential role in the transport of fatty acids into the mitochondria. The deficiency leads to the reduced transport of long-chain fatty acids into the mitochondria, thereby limiting the use of fatty acids for energy production especially during prolonged fasting, febrile illnesses, increased muscular activity, and other periods of systemic stress. We present the anesthetic management of a 10-year-old girl, diagnosed with CACT deficiency at birth, who presented for multiple osteotomies. The preoperative evaluation of such patients is presented, previous reports of anesthetic care are reviewed, and options for intraoperative care are discussed. J Med Cases. 2018;9(5):127-130 doi: https://doi.org/10.14740/jmc3044w

Effects of the complete replacement of fish oil with linseed oil on growth, fatty acid composition, and protein expression in the Chinese mitten crab (Eriocheir sinensis)

BackgroundThe finite marine resources make it difficult for us to obtain enough fish oil (FO) used in aquatic feeds. Another sustainable ingredients should be found to substitute FO. The effects of replacing FO with vegetable oil have been studied in a variety of crustaceans, but most studies have focused on the phenotypic effects. Little is known about the mechanisms of the effects.MethodsTo understand the molecular responses during the replacement of FO in Eriocheir sinensis, we investigated the effects of feeding FO or linseed oil (LO) on growth performance, digestive enzyme activity, fatty acid composition and protein expression in E. sinensis. Twenty-four juvenile crabs were fed diets containing FO or LO for 112 days. Weight, carapace length and width were recorded. Fatty acid composition of the diets and the hepatopancreas and protein expression in the hepatopancreas were analyzed.ResultsGrowth performance and molting interval were unchanged by diet. Crabs fed FO and LO had same activity of lipase and amylase, but comparing with crabs fed LO, crabs fed FO had higher trypsin activity and lower pepsin activity. Hepatopancreas fatty acid composition changed to reflect the fatty acid composition of the diets. In total, 194 proteins were differentially expressed in the hepatopancreas between the diets. Expression of heat shock proteins was higher in crabs fed LO. Expression of fatty acid synthase, long-chain fatty acid transport protein 4, acyl-CoA delta-9 desaturase, and fatty acid-binding protein 1, was higher in crabs fed FO.ConclusionsThe substitution of FO with LO didn’t have any effects on the growth and molting of mitten crab, but could significantly decrease the ability of mitten crab to cope with stress. The high content of HUFAs in the hepatopancreas of mitten crab fed FO is due to the high abundance of the proteins relative to the transport of the HUFAs. These findings provide a reason of the high content of EPA and DHA in crabs fed with FO, and provide new information for the replacement of FO in diets of mitten crab.

The ABC transporter Rv1272c of Mycobacterium tuberculosis enhances the import of long-chain fatty acids in Escherichia coli

Mycobacterium tuberculosis (Mtb), which causes tuberculosis, is capable of accumulating triacylglycerol (TAG) by utilizing fatty acids from host cells. ATP-binding cassette (ABC) transporters are involved in transport processes in all organisms. Among the classical ABC transporters in Mtb none have been implicated in fatty acid import. Since the transport of fatty acids from the host cell is important for dormancy-associated TAG synthesis in the pathogen, mycobacterial ABC transporter(s) could potentially be involved in this process. Based on sequence identities with a bacterial ABC transporter that mediates fatty acid import for TAG synthesis, we identified Rv1272c, a hitherto uncharacterized ABC-transporter in Mtb that also shows sequence identities with a plant ABC transporter involved in fatty acid transport. We expressed Rv1272c in E. coli and show that it enhances the import of radiolabeled fatty acids. We also show that Rv1272c causes a significant increase in the metabolic incorporation of radiolabeled long-chain fatty acids into cardiolipin, a tetra-acylated phospholipid, and phosphatidylglycerol in E. coli. This is the first report on the function of Rv1272c showing that it displays a long-chain fatty acid transport function.

Inhibition of Endothelial Notch Signaling Impairs Fatty Acid Transport and Leads to Metabolic and Vascular Remodeling of the Adult Heart.

Nutrients are transported through endothelial cells before being metabolized in muscle cells. However, little is known about the regulation of endothelial transport processes. Notch signaling is a critical regulator of metabolism and angiogenesis during development. Here, we studied how genetic and pharmacological manipulation of endothelial Notch signaling in adult mice affects endothelial fatty acid transport, cardiac angiogenesis, and heart function. Endothelial-specific Notch inhibition was achieved by conditional genetic inactivation of Rbp-jκ in adult mice to analyze fatty acid metabolism and heart function. Wild-type mice were treated with neutralizing antibodies against the Notch ligand Delta-like 4. Fatty acid transport was studied in cultured endothelial cells and transgenic mice. Treatment of wild-type mice with Delta-like 4 neutralizing antibodies for 8 weeks impaired fractional shortening and ejection fraction in the majority of mice. Inhibition of Notch signaling specifically in the endothelium of adult mice by genetic ablation of Rbp-jκ caused heart hypertrophy and failure. Impaired heart function was preceded by alterations in fatty acid metabolism and an increase in cardiac blood vessel density. Endothelial Notch signaling controlled the expression of endothelial lipase, Angptl4, CD36, and Fabp4, which are all needed for fatty acid transport across the vessel wall. In endothelial-specific Rbp-jκ-mutant mice, lipase activity and transendothelial transport of long-chain fatty acids to muscle cells were impaired. In turn, lipids accumulated in the plasma and liver. The attenuated supply of cardiomyocytes with long-chain fatty acids was accompanied by higher glucose uptake, increased concentration of glycolysis intermediates, and mTOR-S6K signaling. Treatment with the mTOR inhibitor rapamycin or displacing glucose as cardiac substrate by feeding a ketogenic diet prolonged the survival of endothelial-specific Rbp-jκ-deficient mice. This study identifies Notch signaling as a novel regulator of fatty acid transport across the endothelium and as an essential repressor of angiogenesis in the adult heart. The data imply that the endothelium controls cardiomyocyte metabolism and function.

Model-driven discovery of long-chain fatty acid metabolic reprogramming in heterogeneous prostate cancer cells.

Epithelial-mesenchymal-transition promotes intra-tumoral heterogeneity, by enhancing tumor cell invasiveness and promoting drug resistance. We integrated transcriptomic data for two clonal subpopulations from a prostate cancer cell line (PC-3) into a genome-scale metabolic network model to explore their metabolic differences and potential vulnerabilities. In this dual cell model, PC-3/S cells express Epithelial-mesenchymal-transition markers and display high invasiveness and low metastatic potential, while PC-3/M cells present the opposite phenotype and higher proliferative rate. Model-driven analysis and experimental validations unveiled a marked metabolic reprogramming in long-chain fatty acids metabolism. While PC-3/M cells showed an enhanced entry of long-chain fatty acids into the mitochondria, PC-3/S cells used long-chain fatty acids as precursors of eicosanoid metabolism. We suggest that this metabolic reprogramming endows PC-3/M cells with augmented energy metabolism for fast proliferation and PC-3/S cells with increased eicosanoid production impacting angiogenesis, cell adhesion and invasion. PC-3/S metabolism also promotes the accumulation of docosahexaenoic acid, a long-chain fatty acid with antiproliferative effects. The potential therapeutic significance of our model was supported by a differential sensitivity of PC-3/M cells to etomoxir, an inhibitor of long-chain fatty acid transport to the mitochondria.

Development of a Genetic and Clinical Data-Based (GC) Risk Score for Predicting Survival of Hepatocellular Carcinoma Patients After Tumor Resection

Background/Aims: Carnitine palmitoyltransferase 1A (CPT1A) is a rate-limiting enzyme in the transport of long-chain fatty acids for β-oxidation. Increasing evidence has indicated that CPT1A plays an important role in carcinogenesis. However, the expression and prognostic value of CPT1A in hepatocellular carcinoma (HCC) have not been extensively studied. Methods: Here, we collected 66 post-operative liver cancer tissue samples. Gene profile expression was tested by RT-PCR. Receiver operating characteristic (ROC) analysis was performed and multivariate analysis with Cox’s Proportional Hazard Model was used for confirming the selected markers’ predictive efficiency for HCC patients’ survival. A simple risk scoring system was created based on Cox’s regression modeling and bootstrap internal validation. Results: Cox multivariate regression analysis demonstrated that CPT1A, tumor size, intrahepatic metastasis, TNM stage and histological grade were independent risk factors for the prognosis of HCC patients after surgery. Our genetic and clinical data-based (GC) risk scoring system revealed that HCC patients whose total score≥3 are more likely to relapse and die than patients whose total score < 3. Finally, the good discriminatory power of our risk scoring model was validated by bootstrap internal validation. Conclusions: The genetic and clinical data-based risk scoring model can be a promising predictive tool for liver cancer patients’ prognosis after operation.

Anesthetic Management of a Patient With Carnitine-Acylcarnitine Translocase Deficiency

Carnitine-acylcarnitine translocase (CACT) deficiency is a rare disorder of mitochondrial fatty acid metabolism that results in an acute encephalopathic and/or myopathic disorder. Carnitine and CACT play an essential role in the transport of fatty acids into the mitochondria. The deficiency leads to the reduced transport of long-chain fatty acids into the mitochondria, thereby limiting the use of fatty acids for energy production especially during prolonged fasting, febrile illnesses, increased muscular activity, and other periods of systemic stress. We present the anesthetic management of a 10-year-old girl, diagnosed with CACT deficiency at birth, who presented for multiple osteotomies. The preoperative evaluation of such patients is presented, previous reports of anesthetic care are reviewed, and options for intraoperative care are discussed. J Med Cases. 2018;9(5):127-130 doi: https://doi.org/10.14740/jmc3044w

Assessment of AMPK-Stimulated Cellular Long-Chain Fatty Acid and Glucose Uptake.

Here we describe an assay for simultaneous measurement of cellular uptake rates of long-chain fatty acids (LCFA) and glucose that can be applied to cells in suspension. The uptake assay includes the use of radiolabeled substrates at such concentrations and incubation periods that exact information is provided about unidirectional uptakes rates. Cellular uptake of both substrates is under regulation of AMPK. The underlying mechanism includes the translocation of LCFA and glucose transporters from intracellular membrane compartments to the cell surface, leading to an increase in substrate uptake. In this chapter, we explain the principles of the uptake assay before detailing the exact procedure. We also provide information of the specific LCFA and glucose transporters subject to AMPK-mediated subcellular translocation. Finally, we discuss the application of AMPK inhibitors and activators in combination with cellular substrate uptake assays.

Transport of long-chain polyunsaturated fatty acids in preterm infant plasma is dominated by phosphatidylcholine.

Docosahexaenoic (C22:6) and arachidonic (C20:4) acids are long-chain polyunsaturated fatty acids (LC-PUFA) essential to neonatal development, being present in the glycerophospholipids of all organs, particularly the brain. In plasma, LC-PUFAs are mainly present in lipoprotein lipids, which are neutral lipids (triglycerides and cholesterol esters) and glycerophospholipids, like choline containing phosphatidylcholine (PC). To guide future supplementation strategies of C22:6 and C20:4 in combination with choline, we determined the distribution of C20:4 and C22:6 between PC and neutral lipid. Preterm infant plasma (N=59, postmenstrual age [PMA] 33.9wk (32.4-36.0)) and cord plasma (N=34, PMA 34.0wk (30.86-38.4)) were investigated. PC and neutral lipids were extracted and analyzed using tandem mass spectrometry and gas chromatography, respectively. Data are reported as medians and 25th/75th percentiles. In cord blood, C20:4-PC and C22:6-PC comprised 36.1% (34.2-38.6) and 10.2% (8.8-12.8) of total PC, respectively. In preterm infant plasma, values were only 20.8% (19.2-23.1) and 5.7% (5.2-6.0), respectively (p<0.001 each). Nevertheless, in preterm infant plasma, 80.6% (77.6-83.0) of C20:4 and 86.0% (83.0-88.9) of C22:6 were found in PC. These values exceeded the proportions of C20:4 and C22:6 in PC of cord plasma [71.3% (67.8-72.9) and 79.2% (75.2-85.4), respectively] (p<0.0001 each). Irrespective of the low proportions of C20:4-PC and C22:6-PC in preterm infant plasma lipids, PC is the major transporter for C20:4 and C22:6. Our data support the hypotheses that choline deficiency may impair end-organ availability of these LC-PUFA in preterm infants. Therefore, supplementation of C20:4 and C22:6 might better be accompanied by choline supplementation.

Examination of carnitine palmitoyltransferase 1 abundance in white adipose tissue: implications in obesity research.

Carnitine palmitoyltransferase 1 (CPT1) is essential for the transport of long-chain fatty acids into the mitochondria for oxidation. Recently, it was reported that decreased CPT1b mRNA in adipose tissue was a contributing factor for obesity in rats. We therefore closely examined the expression level of Cpt1 in adipose tissue from mice, rats, and humans. Cpt1a is the predominate isoform in adipose tissue from all three species. Rat white adipose tissue has a moderate amount of Cpt1b mRNA, but it is very minor compared with Cpt1b expression in muscle. Total CPT1 activity in adipose tissue is also minor relative to other tissues. Both Cpt1a and Cpt1b mRNA were increased in gonadal fat but not inguinal fat by diet-induced obesity in mice. We also measured CPT1a and CPT1b expression in subcutaneous adipose tissue from human subjects with a wide range of body mass indexes (BMIs). Interestingly, CPT1a expression positively correlated with BMI (R = 0.46), but there was no correlation with CPT1b (R = 0.04). Our findings indicate that white adipose tissue fatty acid oxidation capacity is minor compared with that of metabolically active tissues. Furthermore, given the already low abundance of Cpt1b in white adipose tissue, it is unlikely that decreases in its expression can quantitatively decrease whole body energy expenditure enough to contribute to an obese phenotype.

Carnitine palmitoyltransferase 1A P479L and infant death: policy implications of emerging data.

Carnitine palmitoyltransferase 1 isoform A (CPT1A) is a crucial enzyme for the transport of long-chain fatty acids into the mitochondria. The CPT1A p.P479L variant is found in high frequencies among indigenous populations residing on the west and north coasts of Alaska and Canada and in northeast Siberia and Greenland. Epidemiological studies have reported a statistical association between P479L homozygosity and infant death in Alaska Native and Canadian Inuit populations. Here, we review the available evidence about the P479L variant and apply to these data the epidemiological criteria for assessing causal associations. We found insufficient evidence to support a causal association with infant death and, further, that if a causal association is present, then the genotype is likely to be only one of a complex set of factors contributing to an increased risk of infant death. We conclude that additional research is needed to clarify the observed association and to inform effective preventative measures for infant death. In light of these findings, we discuss the policy implications for public health efforts because policies based on the observed association between P479L homozygosity and infant death data are premature.Genet Med advance online publication 26 January 2017.

Molecular cloning and gene/protein expression of FAT/CD36 from grass carp (Ctenopharyngodon idella) and the regulation of its expression by dietary energy.

Fatty acid translocase/cluster of differentiation 36 (FAT/CD36) functions as a membrane long-chain fatty acid transporter in various tissues in land animals. Not much is known about the CD36 molecule in teleost fish. Therefore, we studied CD36 in grass carp (Ctenopharyngodon idella, ciCD36). The full-length complementary DNA sequence of ciCD36 was 1976bp, with an ORF of 468 amino acids, which had high sequence similarity to the CD36 of common carp. The messenger RNA (mRNA) expression of ciCD36 was high in the intestine, heart, liver, visceral tissue, and brain, but absent in the kidney. The protein expression of ciCD36 was high in the brain, intestine, liver, heart, muscle, eye, visceral tissue, gonad, and gill, but not in the kidney. Four groups of grass carp (16 tanks) were fed three times daily to satiation with 17.2kJ gross energy/g diet (control, CON), 19.4kJ gross energy/g diet (more energy supplied by proteins, HP), 19.9kJ gross energy/g diet (more energy supplied by fat, HF), and 19.1kJ gross energy/g diet (more energy supplied by carbohydrate, HC) for 11weeks, respectively. At the end of the feeding experiment, the fish were fasted for 48h, and the brain, heart, intestine, and liver were sampled and designated as the 0-h samples. The fish were then fed a single meal of the above four diets, and these tissues were collected at 8- and 24-h intervals after refeeding to analyze ciCD36 mRNA and protein expression levels. The results showed that at the transcriptional and translational levels, ciCD36 expression was significantly affected by refeeding time and the different diets (P<0.05), and the regulation of its transcription in different tissues varied. At the translational level, the protein expression levels decreased in the CON and HC groups, and increased in the HP and HF groups after refeeding. The results indicated that ciCD36 has a modulatory role in the adaptation to dietary high energy in grass carp. Translational regulation might be responsible for the observed variations in ciCD36 expression.

Human Chorionic Plate-Derived Mesenchymal Stem Cells Restore Hepatic Lipid Metabolism in a Rat Model of Bile Duct Ligation.

In cholestatic liver diseases, impaired bile excretion disrupts lipid homeostasis. We investigated changes of lipid metabolism, including mitochondrial β-oxidation, in a rat model of bile duct ligation (BDL) in which chorionic plate-derived mesenchymal stem cells (CP-MSCs) were transplanted. Serum cholesterol level, which was elevated after BDL, was significantly decreased following CP-MSC transplantation. The expression levels of genes involved in intracellular lipid uptake, including long-chain fatty acyl-CoA synthetases and fatty acid transport proteins, were decreased in rats after BDL; however, they were not significantly changed by subsequent CP-MSC transplantation. Carnitine palmitoyltransferase 1A (CPT1A), a rate-limiting enzyme in mitochondrial β-oxidation, was upregulated after BDL and then was downregulated after CP-MSC transplantation. CPT1A expression was changed via microRNA-33—a posttranscriptional regulator of CPT1A—in a peroxisome proliferator-activated receptor α-independent manner. Cellular adenosine triphosphate production—an indicator of mitochondrial function—was reduced after BDL and was restored by CP-MSC transplantation. Expression levels of heme oxygenases also were significantly affected following BDL and CP-MSC transplantation. Lipid metabolism is altered in response to chronic cholestatic liver injury and can be restored by CP-MSC transplantation. Our study findings support the therapeutic potential of CP-MSCs in cholestatic liver diseases and help in understanding the fundamental mechanisms by which CP-MSCs affect energy metabolism.

Regulation of Hepatocellular Fatty Acid Uptake in Mouse Models of Fatty Liver Disease with and without Functional Leptin Signaling: Roles of NfKB and SREBP-1C and the Effects of Spexin.

The processes causing increased hepatic triglycerides (TGs) in mouse models of hepatic steatosis (HS) due to high fat diet (HFD)-induced obesity (DIO), EtOH consumption, or obesity mutations (ob/ob, db/db) are uncertain. This report summarizes two studies. Study 1 focused on regulation by five transcription factors (TFs) (NfKb, Srebp-lc, AMPK, PPARα, PPARγ) of seven, much-studied hepatic long-chain fatty acid (LCFA) transporters (FABPpm, CD36, FATPl, FATP2, FATP4, FATP5, & Caveolin-1 [CAV-1]), and expression of genes for enzymes of LCFA synthesis (SCD-1, FASN) in mice with HS from various causes. Study 2 examined the effects of spexin, a novel adipokine, on obesity, type 2 diabetes mellitus (T2DM), and HS in these mice. Study 1 showed that: (1) processes underlying HS differed in mice with normal leptin signaling (DIO, EtoH-fed) versus those without it (ob/ob, db/db). Increased hepatocellular LCFA uptake was the principal cause of HS in the former, but increased hepatocellular LCFA synthesis predominated in the latter. (2) Expression of individual transporters was variable in the HS models studied, but strong correlations between TF expression and mean expression of four transporter genes across multiple HS models suggested regulatory interaction, and support the postulate that complexes of several different transporters mediate hepatic LCFA uptake. Study 2 indicated (1) that obese DIO mice often also have T2DM and/or nonalcoholic fatty liver disease (NAFLD); (2) confirmed that spexin treatment caused weight loss in DIO mice; (3) in DIO mice with T2DM, spexin also improved glucose tolerance, decreasing insulin resistance and HbAlc. Incubation with spexin directly inhibited LCFA uptake by hepatocytes isolated from DIO mice with HS/NAFLD by ≤70%. Spexin treatment in vivo for 4 weeks reduced hepatic lipids by 60%, and reduced serum alanine and aspartate aminotransferases. These studies in mice with DIO, T2DM, and HS/NAFLD suggest spexin may be an effective treatment for all three conditions.