Mutación DGAT1 en dos hermanas con falla de medro: reporte de caso / DGAT1 mutation in two sisters with failure to thrive: a case report

Las diarreas y enteropatías congénitas (CODE por su sigla en inglés) son un grupo de trastornos monogénicos que se han descrito en los últimos años. Dentro de las CODE, la mutación del gen de la diacilglicerol o-aciltransferasa 1 (DGAT1) es un trastorno enzimático poco común asociado con diarrea crónica grave de aparición temprana. El objetivo es presentar a dos hermanas que consultaron por diarrea crónica, retraso en el crecimiento, vómitos e hipoalbuminemia en la primera infancia. En ambas pacientes se encontró un compuesto heterocigota de la mutación del DGAT1. Esta mutación se describió previamente en la población asiática; sin embargo, estas son las dos primeras pacientes en tener esta mutación en la población latinoamericana. Estos dos casos pueden ampliar nuestro conocimiento sobre las diarreas congénitas en general y las características clínicas de los pacientes con mutaciones en DGAT1 en particular.

Congenital diarrhea and enteropathies (CODEs) are a group of monogenic disorders that have been described in recent years. Within the CODEs, the mutation in the diacylglycerol O-acyltransferase 1 (DGAT1) gene is a rare enzyme disorder associated with severe, early-onset chronic diarrhea. Our objective is to describe the case of 2 sisters who consulted for chronic diarrhea, growth retardation, vomiting, and hypoalbuminemia in early childhood. A compound heterozygous DGAT1 mutation was found in both patients. This mutation was previously described in the Asian population; however, these are the first 2 patients to show this mutation in the Latin American population. These 2 cases may expand our knowledge about congenital diarrhea in general and the clinical characteristics of patients with DGAT1 mutations in particular.

Chrysin serves as a novel inhibitor of DGKα/FAK interaction to suppress the malignancy of esophageal squamous cell carcinoma (ESCC)

@#Among current novel druggable targets, protein–protein interactions (PPIs) are of considerable and growing interest. Diacylglycerol kinase α (DGKα) interacts with focal adhesion kinase (FAK) band 4.1-ezrin-radixin-moesin (FERM) domain to induce the phosphorylation of FAK Tyr397 site and promotes the malignant progression of esophageal squamous cell carcinoma (ESCC) cells. Chrysin is a multi-functional bioactive flavonoid, and possesses potential anticancer activity, whereas little is known about the anticancer activity and exact molecular mechanisms of chrysin in ESCC treatment. In this study, we found that chrysin significantly disrupted the DGKα/FAK signalosome to inhibit FAK-controlled signaling pathways and the malignant progression of ESCC cells both in vitro and in vivo, whereas produced no toxicity to the normal cells. Molecular validation specifically demonstrated that Asp435 site in the catalytic domain of DGKα contributed to chrysin-mediated inhibition of the assembly of DGKα/FAK complex. This study has illustrated DGKα/FAK complex as a target of chrysin for the first time, and provided a direction for the development of natural products-derived PPIs inhibitors in tumor treatment.

Construction of rat diacylglycerol kinase gamma lentivirus overexpression vector by homologous recombination / 中国组织工程研究

BACKGROUND: Lentiviral vectors have been widely used as exogenous transgenic vectors. However, a recombinant lentiviral vector containing rat diacylglycerol kinase y (DGKy) gene has not been reported. OBJECTIVE: To construct lentiviral overexpression vector of rat DGKy by homologous recombination. METHODS: Total RNA was extracted from the brain tissue of adult Sprague-Dawley rats, and the cDNA obtained by PCR was used as a template to amplify the 5'-end 1 029 bp and the 3'-end 1 362 bp of the rat DGKy gene CDS. Then, the two homologous recombination fragments were ligated into the plasmid vector. The positive clones were confirmed by PCR and DNA sequencing. The CMV-rat DGKy-GFP lentiviral vector and the lentiviral packaging system were co-transfected into 293T cells for virus packaging and lentivirus was collected to infect 293T cells. The expression of GFP in infected 293T cells was observed under fluorescence microscope. Real-time PCR and western blot assay were used to detect the relative expression of DGKy mRNA in infected 293T cells. RESULTS AND CONCLUSION: The results of PCR simplification and sequencing indicated that the CMV-rat DGKy-GFP lentiviral vector was successfully constructed. In 293T cells infected with CMV-rat DGKy-GFP lentivirus, the expression of GFP was observed under fluorescence microscope and the DGKy mRNA expression was increased significantly than that of the vector group by real-time PCR (P < 0.01). Western blot assay results showed that the DGKy protein expression of the selected GFP-positive 293T cells was increased very significantly (P < 0.001). To conclude, the rat DGKy lentiviral overexpression vector has been successfully constructed and maintains high expression in 293T cells.

Expression and localization of diacylglycerol kinase zeta and protein kinase C beta II in mouse back skin with different coat colors / 中国组织工程研究

BACKGROUND: In the skin and hair pigmentation mechanism, diacylglycerol kinase ζ (DGKζ) has not been reported to participate in pigmentation. OBJECTIVE: To investigate the expression and localization of DGKζ and protein kinase C βII (PKCβII) in the mouse back skin with different coat colors and their correlation with the formation of coat color. METHODS: The back skin of 2-month-old mice with different coat colors (white, gray, and black, 6 mice for each color) was taken to detect DGKζ and PKCβII mRNAs by real-time PCR, DGKζ, PKCβII and p-PKCβII proteins by western blot, and DGKζ and p-PKCβII expression by immunohistochemistry. The study protocol was approved by the Animal Ethics Committee of the Animal Experimental Center of Shanxi Medical University. RESULTS AND CONCLUSION: DGKζ and PKCβII mRNAs were both expressed in the back skin of mice with three kinds of coat colors, with its relative expression amount being: gray group > white group; black group > white group (P white group; black group > white group (P < 0.05). Immunohistochemistry staining showed that DGKζ and p-PKCβII were positively expressed in the outer root sheath of hair follicle, hair matrix cells and melanocytes in the hair matrix in the back skin of gray and black mice, while were negative in the hair follicles of white mice. According to the expression and localization of DGKζ, PKCβII in white, gray and black mouse back skin, we can speculate that DGKζ and PKCβII may participate in the formation of the coat color.

The polymorphisms of genes associated with the profile of fatty acids of sheep / Os polimorfismos de genes associados ao perfil de ácidos graxos de ovinos

The present study aimed to evaluate the occurrence of polymorphisms in Diacylglycerol acyltransferase (DGTA-1 and 2), Fatty acid synthase (FASN), Stearoyl-CoA desaturase (SCD) genes and the Thioesterase domain of FASN (TE-FASN) gene that may be related to the lipid profile. In the experiment, a total of 84 sheep from different genetic groups were used. For the evaluation of the polymorphism of the genes, PCR-Single Strand Conformation Polymorphism (SSCP) technique and subsequent sequencing were used. In DGAT-2 gene, four genotypes were identified with the presence of 6 polymorphisms, with two (c.229T> C; c.255T> C) that resulted into the exchange of phenylalanine by leucine. In FASN gene, two genotypes were identified. In TE-FASN gene, three genotypes and 17 polymorphisms were identified. DGAT-1 and SCD genes did not reveal the occurrence of polymorphism. There was difference in relation to C14: 0, C18: 0 fatty acids and Δ9-desaturase C18 for DGAT-2 gene and of C18: 2ω6t for TE-FASN. There were differences among the genetic groups for C10: 0, C12: 0, C17: 0, C18: 2ω6t, C18: 3ω3, C20: 2, total of ω3, ω3/ω6 and atherogenicity index. There is occurrence of polymorphism of DGAT-2 and TE-FASN genes and these should be further studied in sheep since they revealed influence of the genotypes on the fatty acid profile.(AU)

O presente estudo teve o objetivo de avaliar a ocorrência de polimorfismos nos genes Diacilglicerol aciltransferase (DGTA1 e 2), Ácido graxo sintase (FASN), Estearoil-CoA dessaturase (SCD) e o Domínio da tioesterase do gene FASN (TE-FASN), que possam estar relacionados ao perfil lipídico. No experimento, foram utilizados um total de 84 ovinos de diferentes grupos genéticos. Para avaliação do polimorfismo dos genes, foi utilizada a técnica de polimorfismo de conformação de cadeia simples (PCR-SSCP) e posterior sequenciamento. No gene DGAT-2, foram identificados quatro genótipos com a presença de seis polimorfismos, com dois (c.229T>C; c.255T>C) que resultaram na troca da fenilalanina por leucina. No gene FASN, foram identificados dois genótipos. No gene TE-FASN, foram identificados três genótipos e 17 polimorfismos. Os genes DGAT-1 e SCD não revelaram a ocorrência de polimorfismo. Houve diferença em relação aos ácidos graxos C14:0, C18:0 e ∆9-desaturaseC18 para o gene DGAT-2 e de C18:2ω6t para TE-FASN. Houve diferença entre os grupos genéticos para C10:0, C12:0, C17:0, C18:2ω6t, C18:3ω3, C20:2, total de ω3, ω3/ω6 e índice de aterogenicidade. Há ocorrência de polimorfismo dos genes DGAT-2 e TE-FASN, e estes devem ser mais estudados em ovinos, pois revelaram influência dos genótipos sobre o perfil de ácidos graxos.(AU)

PF-04620110, a Potent Antidiabetic Agent, Suppresses Fatty Acid-Induced NLRP3 Inflammasome Activation in Macrophages

BACKGROUND: Chronic inflammation has been linked to insulin resistance and type 2 diabetes mellitus (T2DM). High-fat diet (HFD)-derived fatty acid is associated with the activation of chronic inflammation in T2DM. PF-04620110, which is currently in phase 1 clinical trials as a selective acyl-CoA:diacylglycerol acyltransferase-1 (DGAT1) inhibitor, is a potent anti-diabetic agent that may be important for the regulation of chronic inflammation in T2DM. However, the mechanisms by which PF-04620110 regulates fatty acid-induced chronic inflammation remain unclear. METHODS: PF-04620110 was used in vitro and in vivo. DGAT1-targeting gRNAs were used for deletion of mouse DGAT1 via CRISPR ribonucleoprotein (RNP) system. The activation of NLRP3 inflammasome was measured by immunoblot or cytokine analysis in vitro and in vivo. RESULTS: Here we show that PF-04620110 suppressed fatty acid-induced nucleotide-binding domain, leucine-rich-repeat-containing receptor (NLR), pyrin-domain-containing 3 (NLRP3) inflammasome activation in macrophages. In contrast, PF-04620110 did not change the activation of the NLR family, CARD-domain-containing 4 (NLRC4), or the absent in melanoma 2 (AIM2) inflammasomes. Moreover, PF-04620110 inhibited K⁺ efflux and the NLRP3 inflammasome complex formation, which are required for NLRP3 inflammasome activation. PF-04620110 reduced the production of interleukin 1β (IL-1β) and IL-18 and blood glucose levels in the plasma of mice fed HFD. Furthermore, genetic inhibition of DGAT1 suppressed fatty acid-induced NLRP3 inflammasome activation. CONCLUSION: Our results suggest that PF-04620110 suppresses fatty acid-induced NLRP3 inflammasome activation.

Association between diacylglycerol kinase kappa variants and hypospadias susceptibility in a Han Chinese population / 亚洲男科学杂志(英文版)

Previous genome-wide association studies have identified variants in the diacylglycerol kinase kappa (DGKK) gene associated with hypospadias in populations of European descent. However, no variants of DGKK were confirmed to be associated with hypospadias in a recent Han Chinese study population, likely due to the limited number of single-nucleotide polymorphisms (SNPs) included in the analysis. In this study, we aimed to address the inconsistent results and evaluate the association between DGKK and hypospadias in the Han Chinese population through a more comprehensive analysis of DGKK variants. We conducted association analyses for 17 SNPs in or downstream of DGKK with hypospadias among 322 cases (58 mild, 113 moderate, 128 severe, and 23 unknown) and 1008 controls. Five SNPs (rs2211122, rs4554617, rs7058226, rs7063116, and rs5915254) in DGKK were significantly associated with hypospadias (P < 0.05), with odds ratios (ORs) of 1.64-1.76. When only mild and moderate cases were compared to controls, 10 SNPs in DGKK were significant (P < 0.05), with ORs of 1.56-2.13. No significant SNP was observed when only severe cases were compared to controls. This study successfully implicated DGKK variants in hypospadias risk among a Han Chinese population, especially for mild/moderate cases. Severe forms of hypospadias are likely due to other genetic factors.

Seed-specific expression of heterologous gene DGAT1 increase soybean seed oil content and nutritional quality / 生物工程学报

Enhancing soybean (Glycine max) oil production is crucial to meet the market demand of vegetable oil. Diacylglycerol acyltransferase (DGAT) catalyzes the final acylation reaction of triacylglycerol (TAG) synthesis, acting as one of the rate-limiting enzymes for oil biosynthesis in plant seeds. Here, a cDNA clone VgDGAT1A encoding the DGAT1 protein was isolated from the high oil plant Vernonia galamensis. VgDGAT1A was specifically overexpressed in soybean seeds, and several high-generation transgenic lines (T7) were obtained by continuous selection. qPCR analysis showed that VgDGAT1A was highly expressed in the mid-development stage (30-45 DAF) of the transgenic seeds. Accordingly, the DGAT enzyme activity in the transgenic seeds was increased by 7.8 folds in comparison with the wild-type controls. Seed oil and starch contents were, respectively, increased by 5.1% (Dry weight) and reduced by 2%-3% in the transgenic soybeans. Importantly, protein content was not significantly different between transgenic and control seeds. Seed weight and germination rate of the transgenic lines exhibited no negative effect. Fatty acid profiling demonstrated that antioxidant oleic acid (C18:1Δ9) content in the transgenic seed oil was elevated by 8.2% compared to the control, and correspondingly, easily-oxidized linoleic acid (C18:2Δ9,12) and linolenic acid (C18:3Δ9,12,15) were decreased by 6% and 2% respectively. Taken together, seed-specific overexpression of an exogenous VgDGAT1A gene can break the negative linkage of oil and protein contents in soybean seeds, indicating that engineering of this highly-active DGAT enzyme is an effective strategy to improve oil yield and nutritional value in oilseeds.

R59022 promotes ET-1-induced cardiac hypertrophy in neonatal rat cardiomyocytes via regulating autophagy / 中国药理学通报

Aim To investigate the effects of DGK in-hibitor R59022 on ET-1-induced myocardial hypertro-phy and autophagy, and explore the possible mecha-nisms. Methods Myocardial hypertrophy was in-duced by ET-1 in cultured rat neonatal cardiomyo-cytes. Western blot was used to detect the expression of microtubule-associate protein 1 light chain 3 ( LC3 ) , beclin-1, p62, p-Akt and Akt. mRNA expression of brain natriuretic peptide ( BNP) and beta mysion heav-y chain (β-MHC) and the cell size of cardiomyocytes were detected by RT-PCR and immunofluorescence, respectively. Results Treatment cardiomyocytes with ET-1(10 -7 mol·L-1 ) for 24 h induced the myocardi-al hypertrophy in cultured neonatal rat cardiomyocytes with the activation of autophagy as evidenced by the in-creased expression of autophagy-related proteins LC3-II/I and beclin-1 , as well as the increased p62 degra-dation. While, myocardial hypertrophy induced by ET-1 , including the increased myocardial cell size and the mRNA expression of fetal gene BNP and β-MHC, could be reversed by autophagy inhibitor 3-methyl ade-nine (3-MA) and chloroquine ( CQ) ,but promoted by autophagy agonist rapamycin ( RAPA ) . Pretreatment cardiomyocytes with R59022, an inhibitor of DGK, en-hanced ET-1-induced myocardial hypertrophy by en-hancing autophagy in cardiomyocytes. Furthermore,ET-1 treatment inhibited the activation of Akt by the down-regulation of the Akt phosphorylation, and R59022 en-hanced the effect of ET-1 on the activation of Akt. Conclusions Enhanced autophagy contributes to car-diomyocyte hypertrophy. R59022 deteriorate ET-1-in-duced myocardial hypertrophy by activating autophagy. The possible mechanism may be related to the inhibi-tion of activation of mTOR signaling pathway by inhibi-ting the activation of Akt.

Diacylglycerol Compounds from Barks of Betula platyphylla with Inhibitory Activity against Acyltransferase / 中草药·英文版

Objective: To identify the active compounds from the barks of Betula platyphylla for inhibitory on diacylglycerol acyltransferase (DGAT1). Methods: Bioassay-guided fractionation resulted in the isolation of DGAT1 inhibitory activity of lupane triterpenes. Results: Ten compounds were identified as lupenone (1), lupeol (2), betulinic acid (3), betulinaldehyde (4), betulin (5), 3-deoxybetulonic acid (6), glochidonol (7), lup-20/29-ene-1β/3β-diol (8), 3α-hydroxy-lup-20(29)-en-23,28-dioic acid (9), and 3α,11α-dihydroxy-23-oxo-lup-20(29)-en-28-oic acid (10). Compounds 3-6, 9, and 10 inhibited DGAT1 with IC50 values ranging from (11.2 ± 0.3) to (38.6 ± 1.2) μmol/L. Conclusion: Compounds 6, 9, and 10 are first isolated from the barks of B. platyphylla., and compounds 3-6, 9, and 10 from the barks of B. platyphylla are responsible for the inhibition on DGAT1. © 2014 Tianjin Press of Chinese Herbal Medicines.

The Effects of a High Fat Diet Containing Diacylglycerol on Bone in C57BL/6J Mice

PURPOSE: In epidemiologic and animal studies, a high fat diet (HFD) has been shown to be associated with lower bone mineral density (BMD) and a higher risk of osteoporotic fractures. Meanwhile, consuming a HFD containing diacylglycerol (DAG) instead of triacylglycerol (TAG) is known to offer metabolically beneficial effects of reductions in body weight and abdominal fat. The purpose of this study was to investigate the effects of a HFD containing DAG (HFD-DAG) on bone in mice. MATERIALS AND METHODS: Four-week-old male C57BL/6J mice (n=39) were divided into three weight-matched groups based on diet type: a chow diet group, a HFD containing TAG (HFD-TAG) group, and a HFD-DAG group. After 20 weeks, body composition and bone microstructure were analyzed using dual energy X-ray absorptiometry and micro-computed tomography. Reverse transcription-polymerase chain reaction (PCR) and real-time PCR of bone marrow cells were performed to investigate the expressions of transcription factors for osteogenesis or adipogenesis. RESULTS: The HFD-DAG group exhibited lower body weight, higher BMD, and superior microstructural bone parameters, compared to the HFD-TAG group. The HFD-DAG group showed increased expression of Runx2 and decreased expression of PPARgamma in bone marrow cells, compared to the HFD-TAG group. The HFD-DAG group also had lower levels of plasma glucose, insulin, total cholesterol, and triglyceride than the HFD-TAG group. CONCLUSION: Compared to HFD-TAG, HFD-DAG showed beneficial effects on bone and bone metabolism in C57BL/6J mice.

Expression and clinical significance of diacylglycerol kinase a and protein kinase C in hepatocarcinoma / 肿瘤研究与临床

ObjectiveTo investigate the expression and the clinical significance of diacylglycerol kinase α (DGKα) and protein kinase C (PKC) in human hepatocellular carcinoma (HCC).MethodsDGKα and PKC expressions in the samples from 60 pathologically confirmed HCC patients were analyzed by immunohistochemistry. The relationship between DGKo expression and clinical pathology factors was analyzed.ResultsThe expression positive rates of DGKo and PKC were highest in normal liver tissues [90.0％ (9/10) and 100.0％ (10/10)].The positive rates were 81.7 ％ (49/60) and 71.7 ％ (43/60) in HCC tissues,respectively,and were 58.3 ％ (35/60) and 61.7 ％ (37/60) in carcinoma adjacent tissues,respectively.In three liver tissues,the positive rates of DGKα and PKC were significantly different (P ＜0.05).The location of both kinases in hepatocytes translocated from cytoplasm/nucleus to membrane.The expressions of DGKα and PKC were positively correlation(r =0.495, P ＜ 0.05), The DGKα expression was correlated to differentiation type,portal venous tumor thrombus and TNM staging(all P ＜ 0.05).ConclusionDGKa is expressed with high activity in advanced stage and poorly differentiated HCC. It may be promote the pathological process of HCC.

Expression of diacylglycerol kinase α mRNA in human hepatocellular carcinoma / 肿瘤研究与临床

Objective To investigate the expression and distribution of Diacylglycerol Kinase α (DGKα) mRNA in human hepatocellular carcinoma (HCC),and to explore the function of DGKα in the metastasis of hepatocellular carcinoma.Methods Tissues from 30 cases of HCC and 5 normal liver tissues were collected immediately after surgical resection.Semi-quantitative RT-PCR and in situ hybridization were used to detect the expression levels and distribution of DGKα mRNA,respectively.Results Semi-quantitative RT-PCR showed that the expression level of DGKα mRNA in HCC (0.798±0.317) and normal tissues (0.908±0.425) was significantly higher than those in carcinoma adjacent tissue with cirrhosis (0.205±0.102,P<0.05).In situ hybridization demonstrated that the number of DGKα mRNA positive hepatocytes in HCC [(57.6±6.3)/mm2] and normal tissues [69.8±8.7)/mm2] was significantly higher than those in carcinoma adjacent tissue with cirrhosis [(26.3±4.9)/mm2,P<0.05]; DGKα mRNA was expressed in the cytoplasm of hepatocytes in HCC and carcinoma adjacent tissue with cirrhosis,and in the nuclear of hepatocytes in normal tissues.Conclusion The present study suggests that DGKa may play important roles in carcinogenesis and progressing of HCC.

Examination of Several FOSHU Used in Hyperlipidemia / 日本補完代替医療学会誌

Among “food for specified health use” (FOSHU) useful in treating life-style related diseases related to arterial sclerosis are those which create a condition in which postprandial serum triglyceride levels fail to rise or are difficult to pass into the body mass. Approximately 70 such FOSHU are recognized as useful in treating hyperlipidemia; in the present review we describe the safety and effectiveness of several of these foods.<br>

Characterization of the DGAT1 gene in the Indian buffalo (Bubalus bubalis)

The positional candidate diacylglycerol O-acyltransferase (DGAT1) gene affecting milk fat percentage is reported in Indian buffaloes (Bubalus bubalis). A comparison with Chinese buffalo (Bubalus bubalis) revealed eight exonic single nucleotide polymorphisms (SNPs), five of which were non-synonymous. A total of 19 SNPs were observed among diverse buffalo breeds in India. A Unique 22 base insertion has been reported in the intron between exon ten and eleven.

Aspectos moleculares del daño tisular inducido por la hiperglucemia crónica / Molecular Aspects of Chronic Hyperglycemia-Induced Tissue Damage

El propósito de este trabajo es dar a conocer las bases moleculares de la fisiopatología de la diabetes mellitus, con el fin de prevenir la enfermedad o mejorar el tratamiento. La diabetes mellitus es una enfermedad compleja, donde la hiperglucemia crónica provoca complicaciones en distintos órganos. En esta condición aumentan las especies reactivas de oxígeno como resultado de su autooxidacción, por lo que su metabolismo propicia la acumulación de metabolitos como la fructosa, el sorbitol y las triosas fosfato. Éstos últimos generan α-oxoaldehídos reactivos con alta capacidad de unirse a proteínas y generar estrés oxidativo. Además, hay aumento de la síntesis de diacilgliceroles a partir de las triosas fosfato, las cuales activan a la pro teína cinasa C. Por otra parte, la alteración de la proporción normal entre los nucleótidos de niacinamida reducidos con respecto a los oxidados conduce a una baja eficiencia de los sistemas antioxidantes. Finalmente, estas desregulaciones metabólicas causan alteración en la transducción de la señal, en la expresión anormal de genes, además de daño tisular, lo que propicia complicaciones en los pacientes con diabetes.

The knowledge of the molecular basis of diabetes mellitus physiopathology will allow improvements in treatment or prevention of the disease. Diabetes mellitus is a complex disease in which hyperglycemia leads to complications in several organs. In this condition, there is increase in reactive oxygen species (ROS) as a result of glucose autooxidation; its metabolism produces accumulation of metabolites such as fructose, sorbitol, and triose phosphate. The latter generates α oxoaldehydes with high capacity to produce protein glycation and oxidative stress. Moreover, there is an increase in synthesis of diacylglycerol from triose phosphate, which activates protein kinase C. On the other hand, alteration of normal ratio between reduced and oxidized niacinamide nucleotides leads to low efficiency of antioxidative systems. Finally, this metabolic dysregulation causes altered signal transduction, abnormal gene expression, and tissue damage, resulting in development of diabetic complications.

EFFECT OF 1, 3-DIAGYLGLYCEROL ON OBESITY AND BLOOD LIPID / 营养学报

Objective: To investigate the effect of 1,3-diacylglycerol(DAG) on reducing blood lipid and obesity. Methods: Fifty SD rats were divided into five groups: triacylglycerol (TAG) low-fat diet, TAG high-fat diet, DAG high-dose , medium-dose and low-dose diet. The rats were fed for 6 w, and body weight was recorded every week. At the end of the experiment, the ratio of visceral fat to body weight was calculated, and blood lipid was analyzed. Results: The body weight of rats in TAG high-fat group was significantly higher than that in TAG low-fat group from the 2nd week (P

ANTIOBESITY ROLES OF DIACYLGLYCEROL AND ITS POSSIBLE METABOLIC MECHANISM / 营养学报

Objective To study the effects of diacylglycerol(DG)on body weight of rats and its possible metabolic mechanism. Method (1) SD rats (n=30) were randomly divided into 3 groups. They were given free access to diets containing 7% (wt) triacylglycerol (TG, control group), 20% (wt) TG or 20% (wt) DG diets, respectively for 8 w. The changes of body weight, height, food intake, and feces were recorded. At the end of experiment, abdominal fat weight (including perirenal fat and epididymal fat), blood lipids were detected. (2) 13 w male Wistar rats (n=50) were divided into 2 groups(administrated with 10% TG or DG emulsion, respectively)in postprandial blood fat profile experiment. Blood lipids of 5 rats were analyzed at desired interval. (3) 6 w male Wistar rats (n=30) were randomly divided into 3 group, control group, DG group and TG group, administrated with glucose solution, 20%DG emulsion and 20%TG emulsion respectively for 6 d. Urine in 144 hr was collected continuously and analyzed for total ketone bodies. Results High DG diet resulted in a significant reduction in both body weight gain, ratio of abdominal fat to body weight and serum TG levels compared with the high TG diet. DG group have higher FFA level in portal vein and lower TG level in jugular vein than those of high TG group. But urine ketone body level of high DG group was higher than high TG group. Conclusion Dietary DG reduced fat accumulation inabdominal region, body and blood, and these effects may be involved with different metabolic ways of DG compared with TG.

The inhibitory mechanism of aloe glycoprotein (NY945) on the mediator release in the guinea pig lung mast cell activated with antigen-antibody complexes

It has been reported that the glycoprotein extracted from Aloe has strong anti-inflammatory response. However, there has been no research report yet about the effect of Aloe on allergic hypersensitivity reactivity. By using guinea pig lung mast cells, this study aimed to examine the effects of Aloe glycoprotein (NY945) on the mediator releases caused by mast cell activation, and also aimed to assess the effects of NY945 on the mechanism of mediator releases in the mast cell activation. We partially purified mast cell from guinea pig lung tissues by using the enzyme digestion, the rough and the discontinuous density percoll gradient method. Mast cells were sensitized with IgG, (anti-OA) and challenged with ovalbumin. Histamine was assayed by fluorometric analyzer, leukotrienes by radioimmunoassay. The phospholipase D activity was assessed by the production of labeled phosphatidylalcohol. The amount of mass 1, 2-diacylglycerol (DAG) was measured by the (3H)-DAG produced when prelabeled with (3H)myristic acid. The phospholipid methylation was assessed by measuring the incorporation of the (3H)methyl moiety into phospholipids of cellular membranes. Pretreatment of NY945 (10 microgram) significantly decreased histamine and leukotrienes releases during mast cell activation. The decrease of histamine release was stronger than that of leukotriene during mast cell activation. The phospholipase D activity increased by the mast cell activation was decreased by the dose-dependent manner in the pretreatment of NY945. The amount of DAG produced by PLC activity was decreased by NY945 pretreatment. The amount of -mass 1, 2-diacylglycerol produced by activation of mast cells was decreased in the pretreatment of NY945. NY945 pretreatment strongly inhibited the incorporation of the (3H)-methyl moiety into phospholipids. The data suggest that NY945 purified from Aloe inhibits in part an increase of 1, 2-diacylglycerol which is produced by activating mast cells with antigen-antibody reactions, which is mediated via phosphatidylcholine-phospholipase D and phosphatidylinositol-phospholipase C systems, and then followed by the inhibition of histamine release. Furthermore, NY945 reduces the production of phosphatidylcholine by inhibiting the methyltransferase I and II, which decreases the conversion of phosphatidylcholine into arachidonic acid and inhibits the production of leukotrienes.

Effects of ginsenosides on the mechanism of histamine release in the guinea pig lung mast cells activated by specific antigen-antibody reactions

We previously reported that some components of ginsenosides decreased mediator releases evoked by the activation of mast cells with specific antigen-antibody reactions. This study aimed to assess the effects of ginsenosides (Rb2, Re) on the mechanism of histamine release in the mast cell activation. We partially purified guinea pig lung mast cells by using enzyme digestion, the rough and the discontinuous percoll density gradient method. Mast cells were sensitized with IgG1 and challenged with ovalbumin (OA). Histamine was assayed by fluorometric analyzer, leukotrienes by radioimmunoassay. Phospholipase D (PLD) activity was assessed more directly by the production of (3H)phosphatidylbutanol (PBut) which was produced by PLD-mediated transphosphatidylation in the presence of butanol. The amount of 1,2-diacylglycerol (DAG) were measured by the (3H)DAG labeled with (3H)palmitic acid or (3H)myristic acid. Pretreatment of Rb2 (300 microgram) significantly decreased histamine release by 60%, but Re (300 gg) increased histamine release by 34%. Leukotrienes release in Rb2 was decreased by 40%, Re was not affected in the leukotrienes release during mast cell activations. An increasing PLD activity during mast cell activation was decreased by the dose-dependent manner in the pretreatment of Rb2, but Re pretreatment facilitated the increased PLD activity during mast cell activation. The amount of DAG produced by phospholipase C (PLC) activity was decreased by Rb2 pretreatment, but Re pretreatment was not affected. The amount of mass DAG was decreased by Rb2 and Re pretreatment during mast cell activation. The data suggest that Rb2 purified from Korean Red Ginseng Radix inhibits the DAG which is produced by the activation of mast cells with antigen-antibody reactions via both phosphatidylinositide-PLC and phosphatidylcholine-PLD systems, and then followed by the inhibition of histamine release. However, Re increases histamine release by stimulation of DAG production, which is mediated by phosphatidylcholine-PLD system rather than by phosphatidylinositide-PLC system, but inhibits the mass DAG production. Thus, it could be inferred that other mechanisms play a role in the increase of histamine release during mast cell activation.