Lipid and Fatty Acid Compositions of Cod (Gadus morhua),Haddock (Melanogrammus aeglefinus) and Halibut (Hippoglossus hippoglossus)

This study was conducted to compare lipid and fatty acid composition of cod,haddock and halibut.Three groups of cod（276 g±61 g）,haddock（538 g±83 g）and halibut（3704 g±221 g）were maintained with commercial feeds mainly based on fish meal and marine fish oil for 12 weeks prior to sampling.The fatty acid compositions of muscle and liver were determined by GC/FID after derivatization of extracted lipids into fatty acid methyl esters（FAME）.Lipids were also fractionated into neutral and polar lipids using Waters silica Sep-Pak（R）.The phospholipid fraction was further separated by high-performance thin-layer chromatography（HPTLC）and the FAME profile was obtained.Results of the present study showed that cod and haddock were lean fish and their total muscle lipid contents were 0.8% and 0.7%,respectively,with phospholipid constituting 83.6% and 87.5% of the total muscle lipid,respectively.Halibut was a medium-fat fish and its muscle lipid content was 8%,with 84% of the total muscle lipid being neutral lipid.Total liver lipid contents of cod,haddock and halibut were 36.9%,67.2% and 30.7%,respectively,of which the neutral lipids accounted for the major fraction（88.1%-97.1%）.Polyunsaturated fatty acids were the most abundant in cod and haddock muscle neutral lipid.Monounsaturated fatty acid level was the highest in halibut muscle neutral lipid.Fatty acid compositions of phospholipid were relatively constant.In summary,the liver of cod and haddock as lean fish was the main lipid reserve organ,and structural phospholipid is the major lipid form in flesh.However,as a medium-fat fish,halibut stored lipid in both their liver and muscle.

Lipid accumulation and CO_2 utilization of two marine oil-rich microalgal strains in response to CO_2 aeration

Biological CO2 sequestration by microalgae is a promising and environmentally friendly technology applied to sequester CO2. The characteristics of neutral lipid accumulation by two marine oil-rich microalgal strains,namely, Isochrysis galbana and Nannochloropsis sp., through CO2 enrichment cultivation were investigated in this study. The optimum culture conditions of the two microalgal strains are 10% CO2 and f medium. The maximum biomass productivity, total lipid content, maximum lipid productivity, carbon content, and CO2 fixation ability of the two microalgal strains were obtained. The corresponding parameters of the two strains were as follows：（（142.42±4.58） g/（m^2·d）,（149.92±1.80） g/（m^2·d））,（（39.95±0.77）%,（37.91±0.58）%）,（（84.47±1.56） g/（m^2·d）,（89.90±1.98） g/（m^2·d））,（（45.98±1.75）%,（46.88±2.01）%）, and（（33.74±1.65） g/（m^2·d）,（34.08±1.32） g/（m^2·d））. Results indicated that the two marine microalgal strains with high CO2 fixation ability are potential strains for marine biodiesel development coupled with CO2 emission reduction.

Regulation of Neutral Lipid Retention by Rab GTPases and Mono-ADP-Ribosylation of CtBP1/BARS

Aberration of lipid storage in lipid droplets (LD) has been linked with the development and progression of several common metabolic diseases including obesity, type II diabetes,

Liver regeneration is associated with lipid reorganization in membranes of the endoplasmic reticulum

BACKGROUND： In recent years, an adaptive endoplasmic reticulum （ER） stress response has been actively investigated. The ER membrane, isolated from the intact and regenerating liver, may be an appropriate model for investigating the association between structural and functional characteristics of ER in vivo and their corresponding behavioral characteristics in vitro. The rate of lipid synthesis and that of intracellular lipid exchange between the ER and cytosol were investigated in the intact and regenerating liver （13 h after partial hepatectomy）. Particularly, membrane characteristics, surface potential, and glucose 6- phosphatase （G6Pase） activity were investigated, along with the degradation rate of G6Pase in vitro, which was estimated by the loss of G6Pase activity, formation of lipid peroxides, and size of excreted membrane vesicles. METHODS： The rate of lipid synthesis was determined by measuring the intensity of radioactive precursor （C^14-sodium acetate） in different fractions of lipids （phospholipids, non-esterified fatty acids, and triacylglycerides） after 30 min exposure. The rate of lipid metabolism was assessed by measuring the quantity oflipids with radioactive labels emerging in the cytosol of hepatocytes （CPM）. Viscosity and surface potential were determined by fluorescent probes. RESULTS： It was observed that after 13 h of partial hepatectomy, the rate of lipid synthesis in the ER of hepatocytes in the regenerating liver was 3 times lower than that in ER ofhepatocytes in the intact liver, wherein the rate of incorporation of newly synthesized lipids in cytosol was several times higher in the regenerating liver. Increase in the rate of exchange of neutral lipids in cells of the regenerating liver was accompanied by lipid reconstruction in the ER, changing the structural and functional characteristics of the membrane. Such membrane rebuilding also contributed to the rate of degradation of the ER in vitro, which that must be taken into account during development of systems for in vitro assessment of xenobiotic metabolism. CONCLUSIONS： An increase in the rate of direct （microsomes→cytosol） and reverse transport of lipids （cytosol→microsomes） was observed in the regenerating liver. Microsomes, isolated from the regenerating liver, were degraded in the in vitro system at a higher rate.

Membrane-bound O-acyltransferases(MBOATs)

The MBOATenzyme family,identified in 2000,comprises 11 genes in the human genome that participate in a variety of biological processes.MBOAT enzymes contain multiple transmembrane domains and share two active site residues,histidine and asparagine.Several MBOAT members are drug targets for major human diseases,including atherosclerosis,obesity,Alzheimer disease,and viral infections.Here we review the historical aspects of MBOAT enzymes,classify them biochemically into 3 subgroups,and describe the essential features of each member.

A novel PNPLA2 mutation causing total loss of RNA and protein expression in two NLSDM siblings with early onset but slowly progressive severe myopathy

Neutral lipid storage disease with myopathy(NLSDM)is a rare autosomal recessive disorder,due to an enzymatic error of lipid metabolism.Patients present always with skeletal muscle myopathy and variable cardiac and hepatic involvement.NLSDM is caused by mutations in the PNPLA2 gene,which encodes the adipose triglyceride lipase(ATGL).Here we report the molecular characterization and clinical findings of two NLSDM siblings carrying the novel c.187t1G>C homozygous PNPLA2 mutation,localized in the splice site of intron 2.Molecular analyses revealed that neither aberrant PNPLA2 mRNA isoforms,nor ATGL mutated protein were detectable in patient’s cells.Clinically,both patients presented early onset muscle weakness,in particular of proximal upper limb muscles.In almost 15 years,muscle damage affected also distal upper limbs.This is a NLSDM family,displaying a severe PNPLA2 mutation in two siblings with clinical presentation characterized by an early onset,but a slowly evolution of severe myopathy.