Fat Cake Research Articles

Biotechnological Valorization of Cupuaçu By-Products: Solid-State Fermentation for Lipase Production by Yarrowia lipolytica

Lipases are enzymes that catalyze the hydrolysis of ester bonds of triacylglycerols at the oil–water interface, generating free fatty acids, glycerol, diacylglycerol, and monoacylglycerol, which can be produced from the fermentation of agro-industrial by-products rich in fatty acids, such as cupuaçu fat cake. In this study, Yarrowia lipolytica IMUFRJ50682 was used for lipase production from cupuaçu fat cake in solid-state fermentation (SSF) associated with soybean meal. The 2:1 ratio of cupuaçu fat cake/soybean meal increased the lipase activity of Y. lipolytica via SSF by approximately 30.3-fold compared to that in cupuaçu without supplementation. The optimal conditions for Y. lipolytica to produce lipase were obtained by supplementation with peptone, urea, and soybean oil (all at 1.5% w/v), reaching values of up to 70.6 U g−1. These results demonstrate that cupuaçu fat cake associated with soybean meal can be used for lipase production and adds value to cupuaçu by-products. Furthermore, the proper processing of by-products can contribute to improving the economic viability of the biotechnological processing industry and help prevent the accumulation of waste and environmental pollution.

Chia gel as fat substitute for producing low fat cake

The increased demands of healthy natural foods represent a challenge for food processors. This work aimed to study the effect of fat substituting with chia (Salvia hispanica L.) gel in producing low-fat cake. Fat was substituted with chia gel containing chia seed with the levels of 25, 50, 75 and 100% which named CG-25, CG-50, CG-75 and CG-100 respectively. The results reveal that chia seeds are a good source of nutrients since it contains 24.95 g/100 g protein, 36.27 g/100 g lipid and ash 5.11 g/100 g (on dry basis) as well as had high caloric value (563.91 kcal/100 g). Regarding the physiochemical properties, cake volume was decreased as substitution level increased (above 50%). Similarly, the cake's specific volume was decreased by increasing of fat substitution level with chia gel. Cake hardness was increased as the substitution level increased, since cake sample CG-25 was more firm than control sample but was less firm than cake sample CG-100. The crust and crumb color of cake samples containing chia gel became darker than that of control sample. The highest (P < 0.05) contents of moisture and protein were recorded for cake sample which formulated with fully substitution of shortening with chia gel (38.90 and 15.75%, respectively) while the lowest contents of the same parameters were observed in control sample (36.48 and 12.01%, respectively). As well as contents of carbohydrates, ash and fibers were increased (from 29.82 to 38.96; 2.06 to 2.41 and 1.58 to 1.72 g/100 g., respectively) as the substitution level of fat increased. On contrary, lipids content was significantly (P < 0.05) decreased as the level of substitution increased, so cake sample CG-100 exhibited a great reduction ratio (79.7%) in lipid content in relation to control sample. Also, the results indicated that the highest caloric value was recorded for control sample (343.99 kcal. /100g), while the cake sample CG-100 exhibited the lowest caloric value (254.66 kcal. /100g). Fatty acids profile was changed by substitution of shortening with chia gel, the decrement ratios of saturated and monounsaturated fatty acids for cake sample CG-100 were 84.17 and 82.46%., respectively, whereas the increment ratio of polyunsaturated fatty acids was 44.62%. Also, sensorial results indicated that no significant effects were observed between different cake samples and control sample in most qualities and they generally were acceptable. Finally, low fat cake can be produced by fat substitution by chia gel with keeping good physiochemical properties and nutritional quality, as well as consumer acceptability.

The effect of oat bran and psyllium husk fibre on oil reduction and some physicochemical properties of magwinya – a deep-fried dough

ABSTRACTOat bran (OB) and psyllium husk fibre (PF) were incorporated into magwinya (fat cake) – a cereal fried dough with the aim of reducing oil content and evaluating some of its physicochemical properties using one-factor of the response surface methodology. Two methods of magwinya processing were employed: traditional (TM) and modified (MM) methods. Addition of PF and OB significantly (p < 0.05) reduced oil in MM compared to TM. Lowest oil content for PF and OB magwinya were 3.10 and 4.35% using MM and 6.00 and 6.25% for TM. Addition of PF up to 3% and OB up to 2% significantly improved textural properties. Comparing the additives and the method of production, optimum conditions with highest desirability of 0.83 was obtained for OB modified magwinya with 35.08% moisture, 2.31% ash and 4.74% oil. Hence, the use of MM and OB reduced oil absorption.

Carrot fibre enrichment of fat reduced cake

Cake is a broadly consumed product and its dietary profile can be improved by using dietary fibre to replace part of flour or fat. The replacement of flour (10-30%) by carrot fibre in full fat and reduced fat cakes was examined. Flour replacement in full fat cakes increased batter viscosity and decreased air incorporation, providing harder cakes with dense structure. Inulin was used to replace 65% of fat in the reduced fat cakes, which presented lower batter viscosity but not significantly different volume development compared to the full fat cake. The incorporation of 10% carrot fibre in the reduced fat formulation appeared to counteract the effect of inulin in terms of batter viscosity and bubble size distribution, but impaired the volume development and the textural properties. The quality characteristics of the enriched cake were improved by the use of emulsifiers (monoglycerides, sodium stearoyl lactylate, diacetyl tartaric acid esters of mono- and diglycerides), which also had a stabilising effect o...

Characterization and functionality of alcohol insoluble solids from tomato pomace as fat substitute in low fat cake

Alcohol insoluble solids from tomato pomace (TAIS) were physico-chemically evaluated to determine its ability to replace fat in low-fat sponge cake. Results showed that TAIS had a high amount of fat (15.8 %) and protein (27.8 %). Total carbohydrate accounts 53.2 % which resulted in the high swelling, water holding capacity and oil holding capacity (5.00, 4.12 and 2.92 mL/g, respectively). Three different blends of the ingredients with fat replacement ratio of 25, 50 and 75 % were formulated in order to examine their effects on quality parameters of low-fat sponge cakes. The incorporation of TAIS powders in cakes batter at all the substitution levels enhanced the specific volume and reduced the specific gravity of the cakes. With increasing TAIS replacement level, dough development, stability, mixing tolerance index and degree of softening increased. Formulations with 25, 50 and 75 % of TAIS had higher water absorption of the dough to be 62.3, 67.1 and 68.6 %, respectively. Arrival time increased to reach 1.5 min in formulations with 25 and 75 % TAIS. It was concluded that substitution of fat with 25 % TAIS might produced acceptable sponge cake with high nutritional value.

Minimizing fishmeal use in juvenile California yellowtail, Seriola lalandi, diets using non-GM soybeans selectively bred for aquafeeds

A study was undertaken to examine the potential of two non-genetically modified (non-GM) soy products, differentially processed, as fishmeal (FM) replacements. Dietary protein (DP) was replaced at 50, 60 and 70% using the 3011 meal or 40, 50 and 60% with the 3032 meal. Ingredient 3011 was a cooked and solvent-extracted meal from a high protein and low oligosaccharide soy cultivar; whereas, ingredient 3032 was a cold-pressed, low fat cake ground to a meal that originated from a medium protein, low oligosaccharide, low protease inhibitor soy cultivar. Experimental diets were isonitrogenous (45% crude protein, CP), isolipidic (13% lipid), isocaloric (12.6 kJ energy kg− 1 of diet) and were balanced for lysine (3.2%) and methionine + cysteine (2%). Taurine was supplemented at 1.5% in all diets. A commercial control diet (52% CP and 13% lipid) was included for a total of eight test diets. Twenty four round tanks (330 L) were each stocked with 20, 4 g yellowtail (Seriola lalandi). Tanks were supplied with recirculated seawater and each diet was randomly assigned to three replicate tanks. After a 10-week feeding trial, growth, survival, feed conversion ratio, protein efficiency ratio, protein retention, condition factor and carcass proximate composition were contrasted among dietary treatments. Results indicate that juvenile yellowtail fed diets in which the 3032 meal provided 50 and 60% of DP grew significantly (P < 0.001) better than those fed all other diets, including the FM-based (menhaden FM) and commercial control diets. Fish fed with the 3011 meal providing 50% of DP and those fed with the 3032 meal providing 40% of DP had similar growth performance which was slightly greater than the fish fed the FM reference diet. Minor intestinal histology differences were found among fish fed the 8 diets. Taken together these data indicates that the improved non-GM soybean meals supported better performance of juvenile yellowtail than fish fed the FM reference diet. No enteritis was detected even at high dietary inclusion levels.

Production and Evaluation of Low Fat Cake Containing Flaxseed and Okra gums as a Fat Replacer

Production and Evaluation of Low Fat Cake Containing Flaxseed and Okra gums as a Fat Replacer

Lipolytic signaling in response to acute exercise is altered in female mice following ovariectomy

Impaired ovarian function alters lipid metabolism, ultimately resulting in increased visceral fat mass. Currently, we have a poor understanding of alterations in signaling events regulating lipolysis after ovarian function declines. The purpose of this study was to determine if cellular mechanisms regulating lipolysis are altered in mice after ovariectomy (OVX) and if OVX mice exhibit impaired lipolytic signaling when stimulated by acute exercise. SHAM and OVX mice were divided into two groups: control (SHAM cont; OVX cont) or acute treadmill exercise (SHAM ex; OVX ex). The omental/mesenteric (O/M) fat mass of all OVX mice was significantly greater than the SHAM mice. Serum glycerol and blood glucose levels were significantly elevated in OVX cont compared to SHAM cont. Treadmill exercise increased serum glycerol levels only in SHAM mice, with no exercise-induced change detected in OVX mice. NEFA levels were significantly elevated by acute exercise in the SHAM and OVX groups. In O/M fat from both OVX groups there were significant increases in cytosolic ATGL and PLIN2 in the fat cake fraction with concurrent reductions in PLIN1 in the fat cake compared to SHAM. Further, exercise induced significant increases in HSL Ser660 phosphorylation in SHAM mice, but not OVX mice. This suggests that reduced ovarian function has significant effects on critical lipolytic cell signaling mechanisms in O/M adipose tissue.

BIOLOGICAL EVALUATION OF LOW – FAT CAKE

Low- fat cake prepared by partial replacement of shortening with Maltodextrin or Simplesse were organoleptically evaluated and subjected to analysis for gross composition and caloric value. A nutrition experiment on rats was conducted to determine the effect of low – fat cake diet on growth parameters and serum lipid profile. The sensory evaluation results indicated that no significant difference (P≤ 0.05) was found among replacement treatments up to 50% replacement level and the full fat cake, and the panelists considered that, all treatments were acceptable up to 75% replacement level. The results of gross chemical composition and caloric value showed a significant decreased (P≤ 0.05) in fat content and caloric value by increasing fat replacement level. The final body weight, weight gain, feed efficiency ratio and the organ weight (% of body weight) of rats were not significantly (P≤ 0.05) affected by fat replacement. Triglycerides (T.G), total cholesterol and low density lipoprotein cholesterol (LDL-C) of serum were significantly (P≤ 0.05) decreased by replacement 50% or 75% of shortening using both fat replacers. The calculated Atherogenic Index was significantly decreased (P≤ 0.05) by fat replacement at ratio of 25%, 50% and 75% by using maltodextrin or at ratio of 50% and 75% by simplesse. Low- fat cake prepared by partial replacement of shortening with Maltodextrin or Simplesse were organoleptically evaluated and subjected to analysis for gross composition and caloric value. A nutrition experiment on rats was conducted to determine the effect of low – fat cake diet on growth parameters and serum lipid profile. The sensory evaluation results indicated that no significant difference (P≤ 0.05) was found among replacement treatments up to 50% replacement level and the full fat cake, and the panelists considered that, all treatments were acceptable up to 75% replacement level. The results of gross chemical composition and caloric value showed a significant decreased (P≤ 0.05) in fat content and caloric value by increasing fat replacement level. The final body weight, weight gain, feed efficiency ratio and the organ weight (% of body weight) of rats were not significantly (P≤ 0.05) affected by fat replacement. Triglycerides (T.G), total cholesterol and low density lipoprotein cholesterol (LDL-C) of serum were significantly (P≤ 0.05) decreased by replacement 50% or 75% of shortening using both fat replacers. The calculated Atherogenic Index was significantly decreased (P≤ 0.05) by fat replacement at ratio of 25%, 50% and 75% by using maltodextrin or at ratio of 50% and 75% by simplesse.

Fat-specific Protein 27 Undergoes Ubiquitin-dependent Degradation Regulated by Triacylglycerol Synthesis and Lipid Droplet Formation

The fat-specific protein 27 (Fsp27), a protein localized to lipid droplets (LDs), plays an important role in controlling lipid storage and mitochondrial activity in adipocytes. Fsp27-null mice display increased energy expenditure and are resistant to high fat diet-induced obesity and diabetes. However, little is known about how the Fsp27 protein is regulated. Here, we show that Fsp27 stability is controlled by the ubiquitin-dependent proteasomal degradation pathway in adipocytes. The ubiquitination of Fsp27 is regulated by three lysine residues located in the C-terminal region. Substitution of these lysine residues with alanines greatly increased Fsp27 stability and enhanced lipid storage in adipocytes. Furthermore, Fsp27 was stabilized and rapidly accumulated following treatment with beta-agonists that induce lipolysis and fatty acid re-esterification in adipocytes. More importantly, Fsp27 stabilization was dependent on triacylglycerol synthesis and LD formation, because knockdown of diacylglycerol acyltransferase in adipocytes significantly reduced Fsp27 accumulation in adipocytes. Finally, we observed that increased Fsp27 during beta-agonist treatment preferentially associated with LDs. Taken together, our data revealed that Fsp27 can be stabilized by free fatty acid availability, triacylglycerol synthesis, and LD formation. The stabilization of Fsp27 when free fatty acids are abundant further enhances lipid storage, providing positive feedback to regulate lipid storage in adipocytes.

Transduction pathways regulating the trophic effects of Saccharomyces boulardii in rat intestinal mucosa

Saccharomyces boulardii is a probiotic yeast that is widely prescribed in lyophilized form; it determines several effects in human and rat small intestine including endoluminal secretion of enzymes and of polyamines, stimulation of microvillous enzymes, of sIgA, increased production of the receptor for polymeric immunoglobulins by crypt cells, and enhanced d-glucose uptake. Aim. The objective of this study was to determine the pathway(s) by which these effects generated by the yeast are transduced into mucosal cells. Methods. Litters of six growing Wistar rats each were treated with S. boulardii (50 μg/gram body weight) or with saline between days 30 and 34 postpartum. For each animal, the cytosol was prepared from the whole mucosa after the fat cake was discarded. Several known intestinal substrates were immunoprecipitated and immunoblotted using specific antibodies recognizing the non-, mono-, or diphosphorylated forms of these substrates. The signals were detected using Echochemiluminoscence (ECL) and were measured by optodensitometry. Results. Treatment with S. boulardii markedly enhanced the RAS-GAP-RAF-ERK1,2 pathway with participation of growth receptor bound 2 protein, SHC, SOS, and CRKII. Unit p85α of phosphatidylinositol 3 kinase, tested in its phosphorylated form, was also enhanced by the probiotic compared to control samples. In rats treated with an inhibitor of RAF-1 and of ERK1,2 (PD098059) the expression of mucosal disaccharidases was inhibited by about 50%. Conclusion. The probiotic S. boulardii generates in vivo mitogen and metabolic signals that are transduced into intestinal mucosal cells, downstream from the apical membrane to the nuclei, using recruitment substrates and serine, threonine, or tyrosine kinases.

Transduction Pathways Regulating The Trophic effects of Saccharomyces boulardii in Rat small intestinal mucosa

AbstractS . boulardii is a probiotic yeast widely prescribed in a lyophilized form that determines in human and rat small intestine several effects including endoluminal secretion of enzymes and of polyamines, stimulation of microvillous enzymes, of sIgA ,increased production of the receptor for polymeric immunoglobulins by crypt cells, and enhanced D-glucose uptake.Aim: The objective of this study was to determine the pathway(s) by which these effects generated by the yeast are transduced into the cell. Methods: Litters of 6 growing Wistar rats each (30 days post partum) were treated with S .boulardii (50[micro]g per g body wt) or with saline during 72 hours. For each animal, the cytosol was prepared from the whole mucosa after the fat cake was discarded. Several known intestinal substrates were immunoprecipitated and immunoblotted using specific antibodies recognizing the non-, mono- or diphosphorylated forms of these substrates. The signals were detected using ECL and were measured by optodensitometry. Results: treatement with S.boulardii enhanced markedly the RAS-GAP-RAF-ERK1,2 pathway with participation of GRB2, SHC, SOS, and CRKII. Unit p85a of Pi-3 kinase ,tested in its phosporylated form, was also enhanced by the probiotic compared to control samples. In rats treated with an inhibitor of RAF-1 and of ERK 1,2 (PD098059) the expression of mucosal disaccharidases was inhibited by about 50%. Conclusion: The probiotic S. boulardii generates in vivo mitogen and metabolic signals which are transduced into intestinal cells downstream from the apical membrane to the nuclei, using recruitment substrates and serine, threonine, or tyrosine kinases .

Signaling the Signal, Cyclic AMP-dependent Protein Kinase Inhibition by Insulin-formed H2O2 and Reactivation by Thioredoxin

Catecholamines in adipose tissue promote lipolysis via cAMP, whereas insulin stimulates lipogenesis. Here we show that H(2)O(2) generated by insulin in rat adipocytes impaired cAMP-mediated amplification cascade of lipolysis. These micromolar concentrations of H(2)O(2) added before cAMP suppressed cAMP activation of type IIbeta cyclic AMP-dependent protein kinase (PKA) holoenzyme, prevented hormone-sensitive lipase translocation from cytosol to storage droplets, and inhibited lipolysis. Similarly, H(2)O(2) impaired activation of type IIalpha PKA holoenzyme from bovine heart and from that reconstituted with regulatory IIalpha and catalytic alpha subunits. H(2)O(2) was ineffective (a) if these PKA holoenzymes were preincubated with cAMP, (b) if added to the catalytic alpha subunit, which is active independently of cAMP activation, and (c) if the catalytic alpha subunit was substituted by its C199A mutant in the reconstituted holoenzyme. H(2)O(2) inhibition of PKA activation remained after H(2)O(2) elimination by gel filtration but was reverted with dithiothreitol or with thioredoxin reductase plus thioredoxin. Electrophoresis of holoenzyme in SDS gels showed separation of catalytic and regulatory subunits after cAMP incubation but a single band after H(2)O(2) incubation. These data strongly suggest that H(2)O(2) promotes the formation of an intersubunit disulfide bond, impairing cAMP-dependent PKA activation. Phylogenetic analysis showed that Cys-97 is conserved only in type II regulatory subunits and not in type I regulatory subunits; hence, the redox regulation mechanism described is restricted to type II PKA-expressing tissues. In conclusion, phylogenetic analysis results, selective chemical behavior, and the privileged position in holoenzyme lead us to suggest that Cys-97 in regulatory IIalpha or IIbeta subunits is the residue forming the disulfide bond with Cys-199 in the PKA catalytic alpha subunit. A new molecular point for cross-talk among heterologous signal transduction pathways is demonstrated.

Role of adipose differentiation-related protein in lung surfactant production: a reassessment

Based on data developed with the use of isolated lipid droplets from neonatal rat lung lipofibroblasts, we speculated previously that the droplet coat protein, adipose differentiation-related protein (ADFP), mediated the transfer of lipids into type 2 lung epithelial cells for the production of surfactant phospholipids. The present studies were designed to test the role of ADFP in this transfer with the use of ADFP-coated lipid droplets from CHO fibroblast cells and a cultured human lung epithelial cell line. We found no role for ADFP in the lipid transfer and conclude that a lipase associated with the lipid droplets hydrolyzes their core triacylglycerols, releasing fatty acids that are taken up by the epithelial cells.

Dual Roles of P2 Purinergic Receptors in Insulin-stimulated Leptin Production and Lipolysis in Differentiated Rat White Adipocytes

ATP is co-localized with norepinephrine at the sympathetic nerve terminals and may be released simultaneously upon neuronal stimulation, which results in activation of purinergic receptors. To examine whether leptin synthesis and lipolysis are influenced by P2 purinergic receptor activation, the effects of ATP and other nucleotides on leptin secretion and glycerol release have been investigated in differentiated rat white adipocytes. Firstly, insulin-induced leptin secretion was inhibited by nucleotide treatment with the following efficacy order: 3'-O-(4-benzoyl)benzoyl ATP (BzATP) > ATP >> UTP. Secondly, treatment of adipocytes with ATP increased both intracellular Ca(2+) concentration and cAMP content. Intracellular calcium concentration was increased by ATP and UTP, but not BzATP, an effect attributed to phospholipase C-coupled P2Y(2). On the other hand, cAMP was generated by treatment with BzATP and ATPgammaS, but not UTP, indicating functional expression of adenylyl cyclase-coupled P2Y(11) receptors in white adipocytes. Thirdly, lipolysis was significantly activated by BzATP and ATP, which correlated with the characteristics of the P2Y(11) subtype. Taken together, the data presented here suggest that white adipocytes express at least two different types of P2Y receptors and that activation of P2Y(11) receptor might be involved in inhibition of leptin production and stimulation of lipolysis, suggesting that purinergic transmission can play an important role in white adipocyte physiology.

Lysophosphatidic Acid Inhibits Adipocyte Differentiation via Lysophosphatidic Acid 1 Receptor-dependent Down-regulation of Peroxisome Proliferator-activated Receptor γ2

Lysophosphatidic acid (LPA) is a bioactive phospholipid acting via specific G protein-coupled receptors that is synthesized at the extracellular face of adipocytes by a secreted lysophospholipase D (autotaxin). Preadipocytes mainly express the LPA(1) receptor subtype, and LPA increases their proliferation. In monocytes and CV1 cells LPA was recently reported to bind and activate peroxisome proliferator-activated receptor gamma (PPARgamma), a transcription factor also known to play a pivotal role in adipogenesis. Here we show that, unlike the PPARgamma agonist rosiglitazone, LPA was unable to increase transcription of PPARgamma-sensitive genes (PEPCK and ALBP) in the mouse preadipose cell line 3T3F442A. In contrast, treatment with LPA decreased PPARgamma2 expression, impaired the response of PPARgamma-sensitive genes to rosiglitazone, reduced triglyceride accumulation, and reduced the expression of adipocyte mRNA markers. The anti-adipogenic activity of LPA was also observed in the human SGBS (Simpson-Golabi-Behmel syndrome) preadipocyte cell line, as well as in primary preadipocytes isolated from wild type mice. Conversely, the anti-adipogenic activity of LPA was not observed in primary preadipocytes from LPA(1) receptor knock-out mice, which, in parallel, exhibited a higher adiposity than wild type mice. In conclusion, LPA does not behave as a potent PPARgamma agonist in adipocytes but, conversely, inhibits PPARgamma expression and adipogenesis via LPA(1) receptor activation. The local production of LPA may exert a tonic inhibitory effect on the development of adipose tissue.

Abca7 Null Mice Retain Normal Macrophage Phosphatidylcholine and Cholesterol Efflux Activity despite Alterations in Adipose Mass and Serum Cholesterol Levels

Mutations in the A class of ATP-binding cassette transporters (ABCA) are causally implicated in three human diseases: Tangier disease (ABCA1), Stargadt's macular degeneration (ABCA4), and neonatal respiratory failure (ABCA3). Both ABCA1 and ABCA4 have been shown to transport lipids across cellular membranes, and ABCA3 may play a similar role in transporting pulmonary surfactant. Although the functions of the other 10 ABCA class transporters identified in the human genome remain obscure, ABCA7-transfected cells have been shown to efflux lipids in response to stimulation by apolipoprotein A-I. In an effort to elucidate the physiologic role of ABCA7, we generated mice lacking this transporter (Abca7-/- mice). Homozygous null mice were produced from intercrosses of heterozygous null mice at the expected Mendelian frequency and developed normally without any obvious phenotypic abnormalities. Cholesterol and phospholipid efflux stimulated by apolipoprotein A-I from macrophages isolated from wild type and Abca7-/- mice did not differ, suggesting that these activities may not be central to the physiological role of the transporter in vivo. Abca7-/- females, but not males, had significantly less visceral fat and lower total serum and high density lipoprotein cholesterol levels than wild type, gender-matched littermates. ABCA7 expression was detected in hippocampal and cortical neurons by in situ hybridization and in brain and white adipose tissue by Western blotting. Induction of adipocyte differentiation from 3T3 fibroblasts in culture led to a marked increase in ABCA7 expression. These studies suggest that ABCA7 plays a novel role in lipid and fat metabolism that Abca7-/- mice can be used to elucidate.

Carboxylesterase 3 (EC 3.1.1.1) Is a Major Adipocyte Lipase

Hydrolysis of triglycerides is central to energy homeostasis in white adipose tissue (WAT). Hormone-sensitive lipase (HSL) was previously felt to mediate all lipolysis in WAT. Surprisingly, HSL-deficient mice show active HSL-independent lipolysis, suggesting that other lipase(s) also mediate triglyceride hydrolysis. To clarify this, we used functional proteomics to detect non-HSL lipase(s) in mouse WAT. After cell fractionation of intraabdominal WAT, most non-HSL neutral lipase activity is localized in the 100,000 x g infranatant and fat cake fractions. By oleic acid-linked agarose chromatography of infranatant followed by elution in a 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid gradient, we identified two peaks of esterase activity using p-nitrophenyl butyrate as a substrate. One of the peaks contained most of the lipase activity. In the corresponding fractions, gel permeation chromatography and SDS-PAGE, followed by tandem mass spectrometric analysis of excised Coomassie Blue-stained peptides, revealed carboxylesterase 3 (triacylglycerol hydrolase (TGH); EC 3.1.1.1). TGH is also the principle lipase of WAT fat cake extracts. Partially purified WAT TGH had lipase activity as well as lesser but detectable neutral cholesteryl ester hydrolase activity. Western blotting of subcellular fractions of WAT and confocal microscopy of fibroblasts following in vitro adipocytic differentiation are consistent with a distribution of TGH to endoplasmic reticulum, cytosol, and the lipid droplet. TGH is responsible for a major part of non-HSL lipase activity in WAT in vitro and may mediate some or all HSL-independent lipolysis in adipocytes.

Lipolysis in the absence of hormone-sensitive lipase: evidence for a common mechanism regulating distinct lipases.

Hormone-sensitive lipase (HSL) is presumed to be essential for lipolysis, which is defined as the mobilization of free fatty acids from adipocytes. In the present study, we investigated the effects of various lipolytic hormones on the lipolysis in adipocytes derived from mouse embryonic fibroblasts (MEF adipocytes) prepared from HSL-deficient mice (HSL-/-). HSL-/- MEF differentiated into mature adipocytes in a manner indistinguishable from that of wild-type mice. Both isoproterenol (ISO) and tumor necrosis factor (TNF)-alpha stimulated the rate of lipolysis in HSL-/- MEF adipocytes, although to a lesser extent than in wild-type cells, and these lipolytic activities were inhibited by H-89, a cAMP-dependent protein kinase inhibitor, and troglitazone, respectively. Thus, the responses of the residual lipolytic activity to lipolytic hormones and TNF-alpha were well conserved in the absence of HSL. Extracts from HSL-/- MEF adipocytes hydrolyzed triacylglycerol (TG) but not cholesterol ester, indicating that the residual lipolytic activity was mediated by another TG-specific lipase. The TG lipase activity, which was decreased in cytosolic fraction in response to ISO, was increased in fat cake fraction. Therefore, translocation of the TG lipase may explain, at least partially, the ISO-stimulated lipolysis in HSL-/- adipocytes. In conclusion, lipolysis is mediated not only by HSL but also by the non-HSL TG lipase, whose responses to lipolytic hormones are similar to those of HSL. We propose that both lipases are regulated by common mechanism of lipolysis.

Infliximab (Remicade) maintenance treatment strategy is superior to episodic treatment in patients with Crohn’s disease

A study was undertaken to examine the potential of two non-genetically modified (non-GM) soy products, differentially processed, as fishmeal (FM) replacements. Dietary protein (DP) was replaced at 50, 60 and 70% using the 3011 meal or 40, 50 and 60% with the 3032 meal. Ingredient 3011 was a cooked and solvent-extracted meal from a high protein and low oligosaccharide soy cultivar; whereas, ingredient 3032 was a cold-pressed, low fat cake ground to a meal that originated from a medium protein, low oligosaccharide, low protease inhibitor soy cultivar. Experimental diets were isonitrogenous (45% crude protein, CP), isolipidic (13% lipid), isocaloric (12.6 kJ energy kg− 1 of diet) and were balanced for lysine (3.2%) and methionine + cysteine (2%). Taurine was supplemented at 1.5% in all diets. A commercial control diet (52% CP and 13% lipid) was included for a total of eight test diets. Twenty four round tanks (330 L) were each stocked with 20, 4 g yellowtail (Seriola lalandi). Tanks were supplied with recirculated seawater and each diet was randomly assigned to three replicate tanks. After a 10-week feeding trial, growth, survival, feed conversion ratio, protein efficiency ratio, protein retention, condition factor and carcass proximate composition were contrasted among dietary treatments. Results indicate that juvenile yellowtail fed diets in which the 3032 meal provided 50 and 60% of DP grew significantly (P < 0.001) better than those fed all other diets, including the FM-based (menhaden FM) and commercial control diets. Fish fed with the 3011 meal providing 50% of DP and those fed with the 3032 meal providing 40% of DP had similar growth performance which was slightly greater than the fish fed the FM reference diet. Minor intestinal histology differences were found among fish fed the 8 diets. Taken together these data indicates that the improved non-GM soybean meals supported better performance of juvenile yellowtail than fish fed the FM reference diet. No enteritis was detected even at high dietary inclusion levels.