Expression Levels Of Lipoprotein Lipase Research Articles

Association of the LPL gene polymorphisms with fatty acid composition in the longissimus dorsi muscle of Hu sheep

Lipoprotein lipase (LPL) is regarded as a candidate gene to regulate fatty acid (FA) composition. The study examined the mRNA expression levels of LPL in different tissues, and conducted a genetic association between the FA composition of the longissimus dorsi muscle of 1029 Hu sheep and the single nucleotide polymorphisms (SNPs) in the LPL gene, as well as the combined genotypes and haplotypes. The results showed that LPL had the highest expression levels in tail fat and subcutaneous fat. Eight SNPs were identified and successfully typed in the intronic region of the LPL gene. Correlation analysis showed that all eight SNPs were related to FA composition. Among them, the CC genotype of SNP1 (g.13879 T>C), the AA genotype of SNP2 (g.13971 A>G), and the TT genotype of SNP3 (g.13993 T>A) had the lowest levels of C8:0 and the highest levels of C18:3n3 content. The TT genotype of SNP6 (g.23413 T>C) and SNP7 (g.23469 T>C) and the AA genotype of SNP8 (g.23472 T>A) had the highest levels of C20:1 content. Linkage disequilibrium analysis showed that SNP1, SNP2, and SNP3 were located in block1, SNP4 (g.17118 A>G) and SNP5 (g.17188 A>G) were located in block2, and SNP6, SNP7, and SNP8 were located in block3. The C18:2n6c content of the TTAAAA combined genotypes in Block1 and the GGGG combined genotypes in Block2 was significantly higher than other combined genotypes. Haplotypes in both Block1 and Block2 significantly affected C18:0, C20:1, and C18:3n3. In conclusion, these genetic markers provide an important source of variation for the selection of FA composition of sheep muscle, which can accelerate the sheep breeding of high-quality meat with a balanced distribution of FA composition.

Adipogenic differentiation effect of human periodontal ligament stem cell initial cell density on autologous cells and human bone marrow stromal cells

AbstractStem cells demonstrate differentiation and regulatory functions. In this discussion, we will explore the impacts of cell culture density on stem cell proliferation, adipogenesis, and regulatory abilities. This study aimed to investigate the impact of the initial culture density of human periodontal ligament stem cells (hPDLSCs) on the adipogenic differentiation of autologous cells. Our findings indicate that the proliferation rate of hPDLSCs increased with increasing initial cell density (0.5–8 × 104 cells/cm2). After adipogenic differentiation induced by different initial cell densities of hPDLSC, we found that the mean adipose concentration and the expression levels of lipoprotein lipase (LPL), CCAAT/enhancer binding protein α (CEBPα), and peroxisome proliferator‐activated receptor γ (PPAR‐γ) genes all increased with increasing cell density. To investigate the regulatory role of hPDLSCs in the adipogenic differentiation of other cells, we used secreted exocrine vesicles derived from hPDLSCs cultivated at different initial cell densities of 50 μg/mL to induce the adipogenic differentiation of human bone marrow stromal cells. We also found that the mean adipose concentration and expression of LPL, CEBPα, and PPARγ genes increased with increasing cell density, with an optimal culture density of 8 × 104 cells/cm2. This study provides a foundation for the application of adipogenic differentiation in stem cells.

Differential Expression of FXR and Genes Involved in Inflammation and lipid Metabolism Indicate Adipose Tissue Dysfunction in Gestational Diabetes

Gestational diabetes mellitus (GDM) is the most frequent metabolic alteration in pregnancy. Several abnormalities in visceral adipose tissue (VAT) have been described as part of its pathophysiology including hypertrophy, inflammation and altered lipid metabolism. Farnesoid X receptor (FXR) is involved in adipocyte physiology and inflammation, so its expression may correlate with the expression of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), lipoprotein lipase (LPL), and two fatty acid transporters (SLC27A2, and SLC27A4). To compare the FXR, LPL, SLC27A2, SLC27A4, TNF-α, and IL-10 mRNA expression in VAT between women with GDM and healthy pregnant (HP) women. Secondarily, to evaluate the potential correlation between these expression levels. Cross-sectional study of 50 GDM and 50 HP women. Conventional biochemical tests were performed and relative mRNA expression in VAT was measured by RT-qPCR. Gene expression levels of FXR and IL-10 were lower, whereas those of LPL, as well as the TNF-α/IL-10 ratio, were higher in women with GDM compared to HP. Pre-pregnancy BMI was the main significant independent variable for FXR levels in VAT from women with GDM. In all women, LPL expression levels correlated positively with those of SLC27A2. Only in women with GDM, IL-10 expression levels correlated negatively with those of SLC27A2, and SLC27A4. GDM is associated with decreased expression of FXR and IL-10 and increased expression of LPL, as well as a higher TNF/IL-10 ratio in VAT. These results suggest increased lipid storage and pro-inflammatory state indicating VAT dysfunction in this metabolic disorder.

Danlou Tablet May Alleviate Vascular Injury Caused by Chronic Intermittent Hypoxia through Regulating FIH-1, HIF-1, and Angptl4.

Background Danlou tablet (DLT), the traditional Chinese medicine has been commonly used for dyslipidemia, atherosclerosis, and coronary heart disease. Whether it was effective against vascular injury caused by CIH has remained unknown. The aim of the current study was to observe the effects of DLT on chronic intermittent hypoxia (CIH)-induced vascular injury via regulation of blood lipids and to explore potential mechanisms. Methods Sixteen 12-week-old male ApoE−/− mice were randomly divided into four groups. The sham group was exposed to normal room air, whereas the other three groups were exposed to CIH. Mice in the CIH + normal saline (NS) group were gavaged with NS. Mice in the CIH + Angptl4-ab group were intraperitoneally injected with Angptl4-antibody. Mice in the CIH + DLT group were gavaged with DLT. After four weeks of intervention, serum lipid concentrations, and serum lipoprotein lipase (LPL) activity were detected. The changes in atherosclerosis in vascular tissue were detected by hematoxylin and eosin (H&E) staining. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis were applied to detect the expression levels of hypoxia-induciblefactor-1 (HIF-1), factor-inhibiting HIF-1 (FIH-1), angiopoietin-like 4 (Angptl4), and LPL in different tissues. Results CIH exposure increases serum lipid levels, decreases serum LPL activity, and exacerbates atherosclerosis. Both Angptl4-ab and DLT treatment reversed the changes in lipid concentration, LPL activity, and atherosclerosis caused by CIH. In the epididymal fat pad, CIH exposure decreased the expression of FIH-1 and increased the expression of HIF-1, whereas DLT treatment increased the expression of FIH-1 and LPL and inhibited the expression of HIF-1 and Angptl4. In heart tissue, the expression levels of LPL and Angptl4 were not affected by modeling or treatment. Conclusions DLT improved vascular damage by improving the increase in blood lipids induced by CIH, potentially by upregulating FIH-1 and downregulating HIF-1 and Angptl4 in adipose tissue. Therefore, DLT may be a promising agent for the prevention and treatment of CIH-induced vascular injury.

Lipid metabolism disorders of hybrid grouper (♀Epinephelus fuscointestinestatus × ♂E. lanceolatu) induced by high-lipid diet

This study investigated the effect of lipid levels on growth, body composition, lipid metabolism enzymes activity and related genes expression in hybrid grouper (♀Epinephelus fuscointestinestatus× ♂E. lanceolatu). Three diets with different lipid levels of 6% (low-lipid feed, LF), 11% (medium-lipid feed, MF) and 16% (high-lipid feed, HF) were designed and each diet was fed to triplicate groups of 30 fish each (6.73 ± 0.00g) for eight weeks. The results revealed the following. 1) The maximum weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER) and the lowest feed conversion ratio (FCR) values were found in the HF group. There was no significant difference in the survival rate (SR) among the groups (P> 0.05). 2) Condition factor (CF), hepatosomatic index (HSI) and visceralsomatic index (VSI) increased with increasing dietary lipid. 3) Crude lipid content in the whole-body and muscle increased significantly as the dietary lipid level increased (P< 0.05). 4) Principal component analysis of fatty acids showed that sum n-3 polyunsaturated fatty acids (∑n-3PUFA)/sum n-6 polyunsaturated fatty acids (∑n-6PUFA) was significantly higher in the HF group than in the other two groups (P< 0.05). 5) Biochemical serum indexes showed higher triglycerides (TG), total cholesterol (TC), alkaline phosphatase (AKP) and low-density lipoprotein-cholesterol (LDL-C) levels but lower high-density lipoprotein-cholesterol (HDL-C) level in the HF group. 6) Liver lipid metabolism enzymes activity and biochemical indicators showed that fish fed the MF diet had higher lipoprotein lipase (LPL), hepatic lipase (HL) and triglyceride lipase (ATGL) activity but lower fatty acid synthase (FAS) activity and very-low density lipoprotein-cholesterol (VLDL-C) level. 7) The relative expression levels of lipoprotein lipase (lpl), adipocyte-type fatty acid-binding protein (a-fabp), liver-type fatty acid-binding protein (l-fabp), heart-type fatty acid-binding protein (h-fabp) and hormone-sensitive lipase (hsl) genes in the fish liver were higher in the MF group with increasing dietary lipid (P< 0.05), while the fatty acid synthase (fas) gene was expressed at lower relative level (P< 0.05). 8) Histological oil-red sections of the liver showed that fish in the HF group had larger and more hepatic lipid droplets than those fed the other diets. It was concluded that fish fed the HF diet had better growth performance but this diet was not conducive to the progress of lipid metabolism, resulting in lipid accumulation and affecting the quality of the fish. This study provides useful information for the formulation of environmentally friendly and cost-effective diets for hybrid grouper.

Expression of lipoprotein lipase and SORL1 genes in patients with chronic lymphocytic leukemia

Introduction. Leukemic cells of patients with chronic lymphocytic leukemia (CLL) are characterized by high expression of the lipoprotein lipase (LPL) gene in unmutated (UM) status of the variable region of the immunoglobulin heavy chain (IGHV) genes and low expression of the SORL1 gene. SORL1 protein promotes the degradation of LPL in nervous cells in vitro that has been previously shown. Objective: to study SORL1 gene expression in CLL patients depending on LPL gene expression and mutational status of IGHV genes. Materials and methods. Analysis was performed in the group of 61 CLL patients. The IGHV gene mutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and SORL1 expression was evaluated by Quantitative Real-time PCR. Results. Relative LPL expression levels in CLL samples ranged from 0.5 to 119.5 (mean 23.65 ± 5.19) and correlated with IGHV mutational status (p < 0.01). The average relative SORL1 expression level was 1.71 ± 0.55. No association between SORL1 expression and IGHV mutational status was found (p = 0.358). Among unmutated IGHV cases, negative correlation between LPL and SORL1 gene expression levels was identified (r = -0.764; p = 0.036). Conclusion. The obtained data support the involvement of SORL1 in the post-translational regulation of LPL levels in leukemic cells in CLL. Ketwords: chronic lymphocytic leukemia, lipoprotein lipase, SORL1.

Characterization of two lipid metabolism-associated genes and their expression profiles under different feeding conditions in Acipenser dabryanus

Acipenser dabryanus is an endemic species restricted to the upper reaches of the Yangtze River and is listed as a national first-class protected animal in China. In the present study, two lipid metabolism-associated genes, namely, lipoprotein lipase (LPL) and apolipoprotein E (apoE), were identified from the full-length transcriptome analysis of A. dabryanus. The full-length genes encoded polypeptides with typical conserved motifs and functional sites shared with their homologues in other fish. Gene expression profile analysis showed that the LPL and apoE genes were constitutively expressed in A. dabryanus. The highest expression level of LPL was found in the muscle, while apoE was predominantly expressed in the liver. In the fasting and refeeding experiment, one hundred twenty fish were randomly assigned to four groups (fasting 0, 3, 7 or 14 d and then refed for 14 d). Fasting and refeeding significantly regulated the expression level of LPL with various expression patterns in different tissues, whereas starvation showed little effect on apoE expression. In addition, the expression levels of LPL and apoE were significantly affected by feeding frequency. The fish were bred for eight weeks at six different feeding frequencies groups (once a day, two times a day, three times a day, four times a day, five times a day and six times a day). Both LPL and apoE expression levels were significantly upregulated in the liver in the highest feeding frequency group. Our study suggests potential roles for LPL and apoE in lipid metabolism in A. dabryanus and will be useful for further study of nutrition regulation in fish.

An evaluation on betaine and trimethylammonium hydrochloride in the diet of Carassius auratus: Growth, immunity, and fat metabolism gene expression

A 6-week feeding trial was conducted to evaluate the effects of betaine power (B-30) and trimethylammonium hydrochloride (T-98) in practical diet on growth performance, immunity, and fat metabolism gene expression of Carassius auratus (initial body weight: 3.37 ± 0.03 g). Control group was fed the basal diet, while four other groups were fed the basal diet supplemented with 1.4 g/kg B-30 (L-B group), 2.8 g/kg B-30 (H-B group), 0.5 g/kg T-98 (L-T group), and 1.0 g/kg T-98 (H-T group). The results revealed a significant improvement in specific growth rates, feed conversion ratio, and weight gain rate with L-B and L-T groups compared to control group, as well as digestive enzyme activity (lipase, amylase and protease) and immunoenzyme activity (acid phosphatase, alkaline phosphatase, lysozyme, catalase from micrococcus lysodeikticu, total antioxidant capacity, and superoxide dismutase) (P < 0.05). Futhermore, the gene expression levels of lipoprotein lipase and liver lipase in L-B and L-T groups were significantly increased compared with the control group, while the gene expression levels of fatty acid synthase were significantly decreased (P < 0.05). These data suggested that supplementation of 1.4 g/kg betaine or 0.5 g/kg trimethylammonium hydrochloride can improve the growth performence, digestive capacity, immunity, and fat metabolism gene expression of C. auratus.

EXPRESSION OF LIPOPROTEIN LIPASE AND c-MYC ONCOGENE IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AFFECTED BY THE CHORNOBYL ACCIDENT.

to determine the association between the expression of lipoprotein lipase (LPL) and c-MYC genes inperipheral blood cells of chronic lymphocytic leukemia (CLL) patients affected by the Chornobyl catastrophedepending on the mutational status of IGHV genes. Analysis was performed in the group of 69 CLL patients irradiated due to the Chornobyl NPP accident (58clean-up workers of 1986 year, 6 inhabitants of radionuclide contaminated areas, and 5 evacuees). The IGHV genemutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and c-MYCexpression was evaluated by Quantitative Real-time PCR. Data were analyzed with the SPSS software package, version 20.0. Relative LPL expression levels in CLL samples ranged from 0 to 1663.5 (mean 138.47 ± 30.69, median 26.1).A strong correlation between individual LPL expression levels and IGHV mutational status was found (r = 0.684;p < 0.0001). The average relative c-MYC expression level was 5.7 ± 0.87 (median 2.86; range 0-48.5). No association between c-MYC expression and IGHV mutational status was found. Among unmutated IGHV cases, a correlationbetween LPL and c-MYC gene expression levels was identified: r = 0.351; p = 0.013. Our data confirm the dominant concept that unmutated IGHV CLL cases are more sensitive to the actionof proliferative stimuli compared to mutated IGHV CLL cases. This is manifested by an increase in the expression ofa functionally significant LPL gene, is one for the strongest negative prognostic markers in CLL.

Anti-Obesity Effects of Lactobacillus fermentum CQPC05 Isolated from Sichuan Pickle in High-Fat Diet-Induced Obese Mice through PPAR-α Signaling Pathway.

Sichuan pickle is a traditional fermented food in China which is produced by the spontaneous fermentation of Chinese cabbage. In this study, the anti-obesity effects of a new lactic acid bacterium (Lactobacillus fermentum CQPC05, LF-CQPC05) isolated from Sichuan pickles were assessed in vivo. An obese animal model was established in mice by inducing obesity with high-fat diet. Both serum and tissues were collected from the mice, and then subjected to qPCR and Western blot analyses. The results showed that LF-CQPC05 could decrease the values of hepatosomatic, epididymal fat, and perirenal fat indices that were induced by a high-fat diet in mice. Moreover, LF-CQPC05 reduced the levels of alanine aminotransferase (ALT), aspartate aminotransaminase (AST), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), and increased the level of high-density lipoprotein cholesterol (HDL-C) in both serum samples and liver tissues of obese mice fed with a high-fat diet. Pathological observations demonstrated that LF-CQPC05 could alleviate the obesity-induced pathological changes in the liver tissue of mice, and reduce the degree of adipocyte enlargement. The results of qPCR and Western blot analyses further indicated that LF-CQPC05 upregulated the mRNA and protein expression levels of lipoprotein lipase (LPL), PPAR-α: peroxisome proliferator-activated receptor-alpha (PPAR-α), (cholesterol 7 alpha-hydroxylase) CYP7A1, and carnitine palmitoyltransferase 1 (CPT1A), and downregulated the expression levels of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and CCAAT enhancer-binding protein alpha (C/EBP-α) in both liver tissue and epididymal adipose tissue. Taken altogether, this study reveals that LF-CQPC05 can effectively inhibit high-fat diet-induced obesity. Its anti-obesity effect is comparable to that of l-carnitine, and is superior to that of Lactobacillus delbrueckii subsp. bulgaricus, a common strain used in the dairy industry. Therefore, LF-CQPC05 is a high-quality microbial strain with probiotic potential.

Regulatory roles of adiponectin receptor 1 and 2 in sheep preadipocytes during adipocyte differentiation

Adipose tissue has long been considered as an energy storage organ. Adipokines, produced by and secreted from adipose tissues, play an important role in regulating fat accumulation, energy balance, and glucose metabolism. Adiponectin receptors (AdipoR1 and AdipoR2) are expressed in various sheep tissues, including adipose tissue. However, the role of adiponectin receptor-mediated signalling has never been investigated in sheep adipose tissue. In this study, sheep preadipocytes were ultimately differentiated into typical adipocytes in vitro 7 days after differentiation. The expression levels of LPL (lipoprotein lipase), HSL (Hormone-sensitive lipase), FAS (fatty acid synthase), and PPARα/PPARγ (peroxisome proliferator-activated receptor alpha/gamma) were significantly changed in the sheep preadipocytes during differentiation for 7 days. After induction of preadipocyte differentiation, lipid accumulation increased significantly in the transfected preadipocytes of AdipoR1-siRNA1 but decreased in the AdipoR1-overexpression (AdipoR1-GFP) preadipocytes. In addition, the expression of HSL and PPARγ was significantly changed in preadipocytes by transfected with AdipoR1-siRNA1 or AdipoR1-GFP. However, the lipid accumulation and adipogenic gene expression were not significantly changed in preadipocytes by transfected with AdipoR2-siRNA2 and AdipoR2-GFP. Taken together, these results indicate that AdipoR1 could regulate sheep adipose metabolism via regulating HSL and PPARγ expression during adipocyte differentiation.HighlightsWe first established an in vitro culture system for sheep preadipocytes derived from the paraspinal muscle adipose.Sheep preadipocytes were ultimately differentiated into typical adipocytes after induction and differentiation.Both suppression and overexpression of adiponectin receptor 1 expression affect lipid accumulation and adipocyte metabolism during adipocyte differentiation.

Effects of fasting on the activities and mRNA expression levels of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS) in spotted seabass Lateolabrax maculatus.

To investigate the effects of fasting on lipid metabolism in spotted seabass muscle and liver tissues, we analyzed mRNA levels and enzyme activities of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS), and the relationship among fat content, mRNA level, and enzyme activity during fasting of 35days. The results showed that expressions of all the three genes were ubiquitous. During the fasting experiment, the hepatosomatic index (HSI) and fat content of muscle and liver tissues significantly decreased before 5days of fasting (P < 0.05). mRNA levels of LPL increased significantly after 5days of fasting in liver and 7days in muscle. Abundance of HSL transcripts increased significantly after 14days of fasting in both muscle and liver. The activities of LPL and HSL presented a trend that increased firstly, decreased subsequently, and then raised again with the prolonged fasting experiment (P < 0.05). However, activities and mRNA levels of FAS decreased significantly after 1day of fasting in both muscle and liver. Moreover, activities and mRNA levels of FAS showed a moderate correlation in muscle. These results suggested that FAS had a sooner response to fasting than LPL and HSL in both muscle and liver tissues. LPL and HSL played important roles in lipolysis mainly by increasing enzyme activities in the early stage of fasting and mRNA levels in the later stage of fasting in both muscle and liver. Our results also provided useful information on regulating muscle fat content by fasting.

Dietary Lipid Sources Influence Fatty Acid Composition in Tissue of Large Yellow Croaker (Larmichthys crocea) by Regulating Triacylglycerol Synthesis and Catabolism at the Transcriptional Level.

An 8-week feeding trial was conducted to evaluate the effects of dietary lipid sources on growth performance, fatty acid composition, rate-limiting enzyme activities and gene expression related to lipid metabolism in large yellow croaker (Larmichthys crocea). Five iso-nitrogenous and iso-lipidic experimental diets were formulated to contain different lipid sources, such as fish oil (FO), soybean oil (SO), linseed oil (LO), rapeseed oil (RO) and peanut oil (PO), respectively. Triplicate groups of 50 fish (initial weight 13.77±0.07g) were stocked in 15 floating net cages (1.5m×1.5m×2.0m). Fish fed the diets containing RO and LO had lower weight gain and specific growth rates than those fed the FO, SO and PO diets. Survival, feed efficiency, protein efficiency ratio, hepatosomatic index, viscerasomatic index and condition factor were not significantly affected by different dietary lipid sources. Fish fed the diet containing FO had higher lipid content in whole body compared with the other groups, whereas fish fed the SO diet had the lowest muscle lipid content. Fatty acid profiles of muscle and liver reflected the fatty acid composition of the diets. Plasma glucose, triglyceride, and the enzymatic activity of aspartate aminotransferase and alanine aminotransferase were significantly influenced by different dietary lipid sources, while total protein, cholesterol, superoxide dismutase or malondialdehyde in plasma were not affected by the different dietary lipid sources. Fish fed the LO diet had lower adipose triglyceride lipase and fatty acid synthase activities in liver than those fed the diets containing FO and RO, while the LO diet resulted in the highest hepatic carnitine palmitoultransferase-1 activity. Hepatic gene relative expression of adipose triglyceride lipase and carnitine palmitoyltransferase-1 in fish fed PO diet was significantly higher than all other groups, whereas fish fed the SO and LO diets had lower relative expression levels of lipoprotein lipase than the other groups. The highest relative expression levels of fatty acid synthase and acyl-CoA diacylglycerol acyltransferase-2 were observed in the FO group, while the highest relative expression of glucose 6-phosphate dehydrogenase occurred in fish fed the FO and RO diets. In summary, based on the growth performance, FO and SO appear to be suitable lipid sources for large yellow croaker, with the findings of this study also providing a molecular insight into the role of lipid metabolic mechanism in response to different dietary lipid sources.

Maternal undernutrition leads to elevated hepatic triglycerides in male rat offspring due to increased expression of lipoprotein lipase.

Small for gestational age (SGA) at birth increases the risk of developing metabolic syndrome, which encompasses various symptoms including hypertriglyceridemia. The aim of the present study was to determine whether maternal undernutrition during pregnancy may lead to alterations in hepatic triglyceride content and the gene expression levels of hepatic lipoprotein lipase (LPL) in SGAmale offspring. The present study focused on the male offspring in order to prevent confounding factors, such as estrus cycle and hormone profile. FemaleSprague Dawley rats were arbitrarily assigned to receive an adlibitum chow diet or 50%food restricted diet from pregnancy day1 until parturition. Reverse transcription quantitative polymerase chain reaction and western blot analysis were used to measure the gene expression levels of hepatic LPL at day1 and upon completion of the third week of age. Chromatin immunoprecipitation quantified the binding activity of liverX receptor‑α (LXR‑α) gene to the LXR response elements (LXRE) on LPL promoter and LPL epigenetic characteristics. At 3weeks of age, SGA male offspring exhibited significantly elevated levels of hepatic triglycerides, which was concomitant with increased expression levels of LPL. Since LPL is regulated by LXR‑α, the expression levels of LXR‑α were detected in appropriate for gestational age and SGA male offspring. Maternal undernutrition during pregnancy led to an increase in the hepatic expression levels of LXR‑α, and enriched binding to the putative LXR response elements in the LPL promoter regions in 3‑week‑old male offspring. In addition, enhanced acetylation of histoneH3 [H3lysine (K)9 and H3K14] was detected surrounding the LPL promoter. The results of the present study indicated that maternal undernutrition during pregnancy may lead to an increase in hepatic triglycerides, via alterations in the transcriptional and epigenetic regulation of the LPL gene.

Gene expression and enzyme activity of lipoprotein lipase correlate with intramuscular fat content in Guangxi san-huang and Arbor Acres chickens.

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. This study investigated LPL gene expression, LPL enzyme activity, and the correlation of each with intramuscular fat (IMF) in Chinese Guangxi san-huang (GXSH) and Arbor Acres (AA) chickens. The results showed that age and breed had significant effects on LPL expression and enzyme activity. Correlation analyses showed significant positive correlations between LPL expression levels and IMF contents in the breast and thigh tissues of both GXSH (r = 0.712, P = 0.001; r = 0.792, P < 0.001, respectively) and AA (r = 0.644, P < 0.001; r = 0.545, P < 0.001, respectively) chickens. The results also indicated a significant positive correlation between LPL enzyme activity and IMF contents in the breast and thigh tissues of both GXSH (r = 0.615, P = 0.001; r = 0.685, P < 0.001, respectively) and AA (r = 0.600, P = 0.001; r = 0.528, P = 0.003, respectively) chickens. The results indicated that the LPL gene was significantly correlated with IMF in these two breeds. The results presented here could contribute to knowledge of LPL mRNA developmental expression patterns and enzyme activity, and it could facilitate further research on the molecular mechanisms underlying IMF deposition in chickens.

Lipoprotein lipase gene polymorphism rs1059611 functionally influences serum lipid concentrations

ObjectiveDozens of single nucleotide polymorphisms (SNPs) in the lipoprotein lipase (LPL) gene have been reported to be associated with lipid concentrations. The aim of this study was to validate the association between rs1059611 in the LPL gene and serum lipid concentrations in the Chinese Han population and explore the biological relevance. MethodsA total of 5664 participants were recruited and genotyped for the SNP. Gene expression levels of LPL in blood cells were evaluated by real-time PCR and western blotting analysis. The functional potential of the SNP was examined by luciferase reporter assay and electrophoretic mobility-shift assay (EMSA). ResultsWe observed significant associations between rs1059611 and increased HDL-C (P = 5.65 × 10−5) and decreased TG concentrations (P = 2.68 × 10−7). We also found that participants with the C allele had higher mRNA expression level (P = 0.0334) and protein expression level (P = 0.0641) of LPL. The luciferase activity of the rs1059611 T construct was 0.69-fold of the rs1059611 C construct (P = 0.0009). The EMSA showed that the binding of the transcription factor(s) differed for the alleles of the SNP. ConclusionThe results of our study demonstrated that rs1059611 was associated with HDL-C and TG concentrations in Chinese Han population and might have a functional effect on the transcription of LPL by differential binding of transcription factors.

Changes in the activities and mRNA expression levels of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS) of Nile tilapia (Oreochromis niloticus) during fasting and re-feeding

This study aimed to characterize the dynamic changes in the growth and proximate composition of liver and muscle tissue in the Nile tilapia (Oreochromis niloticus) during feed restriction followed by re-feeding. In addition, we measured triacylglycerol (TAG), high density lipoprotein-cholesterol (HDL-C) and glucose (GLU) levels in serum and the mRNA levels and the activity levels of lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and fatty acid synthetase (FAS) in liver. Nile tilapia with an initial body weight of 62.50±3.44g were starved for 28days and then fed for 21days under a controlled indoor environment. Fish were sampled at days 0, 7, 14, 21 and 28 of fasting (F0, F7, F14, F21 and F28, respectively) and days 14 and 21 of re-feeding (RF14 and RF21, respectively). The results indicate that body weight decreased significantly by F14, and significantly increased at RF21 (P<0.05). The hepatosomatic index was significantly decreased throughout the experiment (P<0.05). The fat content in liver and muscle decreased significantly by F7 and F14 (P<0.05), and the protein content decreased significantly by F7 and F28 (P<0.05), respectively. Significant reductions were observed in the serum content of TAG and GLU during fasting. Following re-feeding, values for these indices recovered to varying degrees. There was no change in serum HDL-C levels during the experiment (P>0.05). The activity and relative mRNA expression of FAS in the liver both significantly decreased under fasting conditions, but were significantly increased at RF21 (P<0.05). LPL and HSL mRNA hepatic levels were significantly upregulated during fasting, and LPL activity increased in response to fasting, whereas HSL activity increased by F14, and decreased to basal levels at F28. Following re-feeding, the activity and mRNA expression of LPL decreased. The hepatic expression of HSL mRNA decreased, but hepatic HSL activity increased (P<0.05).

Characterization of actions of octanoate on porcine preadipocytes and adipocytes differentiated in vitro

Octanoate is used to induce adipogenic differentiation and/or lipid accumulation in preadipocytes of domestic animals. However, information on detailed actions of octanoate and the characteristics of octanoate-induced adipocytes is limited. The aim of this study was to examine these issues by comparing the outcomes of the effects of octanoate with those of rosiglitazone, which is a well-defined activator of peroxisome proliferator-activated receptor (PPAR)-γ. The adipocytes that were differentiated with 5mM of octanoate had dispersed and diversely sized lipid droplets compared to those that were differentiated with 1μM of rosiglitazone. The gene expression levels of adiponectin, glycerol-3-phosphate dehydrogenase, perilipin 1, and perilipin 4 were much higher in the adipocytes that were differentiated with rosiglitazone than in those differentiated with octanoate, while the gene expression levels of lipoprotein lipase and perilipin 2 were decreased in rosiglitazone-differentiated adipocytes compared to octanoate-differentiated adipocytes. However, the expressions of aP2 and CD36 genes were comparably induced. Luciferase reporter assays revealed that PPAR and liver-X-receptor activities were upregulated by octanoate more effectively than by rosiglitazone. Overall, these results suggested that the action of octanoate was complicated and may be dependent on the targeted genes and cellular status.

Association of lipoprotein lipase polymorphism rs2197089 with serum lipid concentrations and LPL gene expression

Many single-nucleotide polymorphisms (SNPs) have been reported to be associated with lipid concentrations in recent genome-wide association studies. The aim of this study was to validate the associations of rs2197089 in the lipoprotein lipase (LPL) gene with serum lipid concentrations and gene expression levels in the Chinese Han population and examine the potential interactions. A total of 9339 participants were recruited and genotyped for rs2197089. Gene expression levels of LPL in blood cells of 309 participants were evaluated by real-time PCR. We observed significant associations between rs2197089 and decreased triglycerides (TG) (P=0.0006), but not high-density lipoprotein cholesterol (HDL-C) concentration (P=0.0881). However, weak evidence of interaction between cigarette smoking and rs2197089 was detected (P=0.0362). In smokers, significant association between rs2197089 and increased HDL-C concentration was found (P=0.0068). Participants with the minor allele A had higher expression levels of LPL (P=0.0243). The results of our study indicated that rs2197089 was significantly associated with TG but it was associated with HDL-C only in smokers. This SNP seemed to have influence on the expression level of LPL.

N-acetyl-L-cysteine enhances the osteogenic differentiation and inhibits the adipogenic differentiation through up regulation of Wnt 5a and down regulation of PPARG in bone marrow stromal cells

Nowadays, the treatment of osteoporosis is still a great challenge in the medical field. The combination of enhancement of osteogenesis and the inhibition of adipogenesis of bone marrow stromal cells (BMSCs) is considered an efficient therapeutic strategy for the treatment of osteoporosis. In the present study, we investigated the effects of N-acetyl-L-cysteine (NAC) on the proliferation, osteogenesis and adipogenesis of BMSCs. NAC treatment enhanced the alkaline phosphatase activity, mineral deposition and mRNA expression levels of osteogenesis markers collagen I, osteopontin, and signal pathway related protein Wingless-type family member 5a in addition to Wingless-type family member 3a during osteogenic induction, and inhibited the accumulation of lipid droplets and the expression levels of lipoprotein lipase, fatty acid binding protein 4 and peroxisome proliferator-activated receptor gamma mRNA during adipogenic induction. Meanwhile, NAC had the same effects as enhancing mineral deposition in regular culture condition. In addition, cell proliferation was also promoted by NAC treatment in regular culture condition. These results suggested that NAC may enhance osteogenic differentiation and inhibit adipogenic differentiation of BMSCs, which is at least partially mediated by up regulating Wnt 5a and down regulating PPARG. Taking into account the extensive protective effects of NAC and that the maintenance of BMSCs number is an important factor in osteoporosis prevention and treatment, these observations suggested that NAC is a promising potential drug for the prevention and treatment of osteoporosis and its associated diseases.