Abstract: Bardet-Biedl syndrome (BBS) is an autosomal recessive disorder associated with marked obesity. Research in rare forms of obesity has identified genes with significant roles in common obesity etiology. To date, 11 BBS genes have been cloned (BBS1-BBS11). However, the function of BBS genes in adipogenesis is unknown. Moreover, not all BBS genes have been shown to be expressed in adipose tissue. The aim of our study was to investigate the expression of BBS genes throughout adipogenesis. 3T3-F442A preadipocyte cells were harvested throughout the adipogenesis process (from day 1 to 8) at 1-day intervals. Levels of BBS genes transcripts were analyzed by quantitative real-time polymerase chain reaction (PCR). Additionally, transcript levels of BBS5-9 and BBS11 were studied in mouse (C57BL/6) adipose tissue. We have shown for the first time that BBS5-9 and BBS11 are expressed in adipose tissue. Significant variations in the transcript levels of the BBS genes were identified throughout adipogenesis. Compared to the their levels in non-differentiated preadipocytes, transcript levels of BBS1-4, 6-9 and 11 were significantly augmented through differentiation, reaching maximum values at day 3 (BBS1-4, 6-8) and 4 (BBS9 and 11) by 3.5, 4, 2.9, 3, 5, 1.9, 2, 2.9 and 2.6-fold, respectively. These findings show for the first time a unique, temporal and synchronized expression of BBS genes during adipogenesis. These findings highlight the importance of BBS genes functional studies in adipogenesis.

Abstract: Leptin, an adipokine, a major regulator of food intake, was recently suggested to play a role in immune response. We previously showed that weight reduction following IFNalpha therapy is due, at least in part, to direct induction of adipose tissue apoptosis. We now studied the effect of leptin on IFNalpha treated adipocytes in vitro and in vivo. Diet induced obese C57/B6 mice were treated continually with recombinant (r) IFNalphaA/D + leptin (100 U/g body weight + 10 microg/day, respectably) or leptin (10 microg/day) alone for 8 days. Co-administration of IFNalphaA/D + leptin significantly reduced plasma cholesterol (P<0.001), glucose (P<0.007) and pro-apoptotic protein levels (P<0.05). Additionally, co-administration prevented loss of body weight due to adipocyte apoptosis. Thus, leptin co-administration with IFNalphaA/D decreases some of the side effects of IFNalpha administration such as weight loss, cholesterol and glucose levels.

Abstract: Adipogenic and osteogenic cells share part of the early differentiation cascade of mesenchymal stem cells (MSCs). The choice of a mesenchymal precursor cell to differentiate into a particular cell type is dictated by many spatial and temporal cues, including growth factors, neighboring mature cells, and the extracellular matrix (ECM), which plays an important role in bone formation. Whether adipocytes that have initiated differentiation along one lineage can convert into osteogenic lineage by merely interacting with materials having specific surface parameters is unknown. Using crystalline three-dimensional (3D) biomatrices of marine origin (CaCO(3)), we explored whether preadipocytes can convert into osteoblasts. Cells (3T3F442A) were seeded on 3D biomatrices of marine origin (Porites lutea). Analyses were made at different time intervals-1, 2, 5, 7, 14, 21, and 28 days post-seeding. Cell characterizations were done using morphological (light microscopy and scanning electron microscopy), histological (Alizarin red, von Kossa and Oil red O staining), enzymatic (alkaline phosphatase activity, and quantitative PCR testing transcript levels of osteocalcin, alkaline phosphatase, core binding factor- 1 (Cbfa1), and fatty acid binding protein (aP2). We demonstrated 3T3F442A preadipocyte modulation and differentiation into bone-forming cells when grown on biomatrix of marine origin without addition of other bone morphogenesis inducers. We found an active ossification process typical of osteogenic phenotype as early as 2 days after seeding. It is suggested that this crystalline biomatrix having a particular 3D topology or surface parameters supports fast cellular adhesion, proliferation, and differentiation of preadipocytes to osteogenic phenotype.

Abstract: Chronic surplus of dietary consumption, typical to obesity, results in overflow of fat to non-adipose tissues. Intracellular accumulation of fat in non-adipose tissues is associated with cellular dysfunction and cell death and ultimately contributes to the pathogenesis of chronic diseases. The influence of fat overflow on the exocrine pancreas is not known. The purpose of this research was to study the lipotoxic and lipoapoptotic effect of prolonged (72 h) long chain saturated palmitic fatty acid (0.1 mM) on the survival of exocrine pancreas AR42J cells. We demonstrate that chronic exposure of AR42J cells to palmitic acid results in significant increase in triglycerides accumulation (up to 25% of cells area), compared to untreated cultures. Lipid accumulation prompted a typical apoptotic process, demonstrated by both DNA fragmentation and condensed chromatin appearance (DAPI staining). Quantitative real-time PCR studies demonstrated that prolonged palmitic acid supplementation induced down-regulation of the anti-apoptotic Bcl2 mRNA levels (22%) and up-regulation of the pro-apoptotic Bax mRNA levels (300%), leading to disruption of the pro/anti apoptotic balance (Bax/Bcl2=3). No major change was detected in iNOS mRNA expression.In conclusion, prolonged exposure to saturated palmitic acid induces lipoapoptosis in exocrine pancreatic AR42J cells, through disturbance of the Bax/Bcl-2 balance.

Abstract: Interferon alpha (IFN-alpha) is produced in response to viral infections and used clinically in the therapy of a variety of cancers and viral infections. IFN-alpha treatment is often associated with severe weight reduction. To elucidate the mechanism of IFN-associated weight loss, we studied its effect on adipocytes in vitro and in vivo. Diet-induced obese (DIO) C57BL/6 mice were treated continuously for 8 days with human IFN-alpha A/D (100 U/g body weight) or with vehicle alone. The body weight and adipose cell size of IFN-alpha A/D-treated DIO mice were significantly lower (P<0.05 and P<0.001, respectively) as compared with those of control DIO mice. PI3K and Bcl-2 were down-regulated whereas Bax expression was elevated in adipose tissue following IFN treatment as compared to adipose tissue of control DIO mice. Treatment of differentiated 3T3-F442A adipocytes with IFN-alpha A/D (250 U/ml, 36 h) significantly increased the number of apoptotic cells from 15.8% in control cells to 56+/-6%. In conclusion, weight loss following IFN-alpha therapy is due at least in part to increased apoptosis of adipocytes.

Abstract: Leptin, a metabolic regulator of energy expenditure, exerts its peripheral effects primarily by altering lipid metabolism. The exocrine pancreas has a key role in the digestion of dietary lipids, but the role of leptin in regulating pancreatic lipases remains unknown. Using the exocrine pancreas in vitro AR42J cell model, we studied the direct effects of leptin on pancreatic lipase (PL) secretion and on the mRNA levels of PL and PL-related proteins 1 and 2 (PLRP1, PLRP2). Leptin directly, rapidly (within 30 min) and significantly inhibited both the secretion and intracellular activity of PL. Leptin downregulated mRNA levels of PL and PLRP1, and upregulated transcripts of PLRP2. This study provides the first evidence that leptin directly regulates exocrine lipases at the levels of synthesis, activity and secretion. This rapid regulation may be associated with a short-term control of energy balance.

Abstract: Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene-nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient-genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.

Abstract: Lactation alters maternal metabolism and increases food intake in rats to support milk production. Pancreatic lipase (PL) is primarily responsible for fat digestion in adults and is regulated by dietary fat. The present research determined the regulation of PL by lactation and dietary fat. In Expt 1, eighteen Sprague-Dawley dams and twelve age-matched virgins (controls) were fed a low-fat diet (LF; 11 % energy as safflower oil) for 7-63 d. At postpartum (day 0), peak lactation (day 15) and post-lactation (day 56) and after 7 d in virgins, the pancreas was removed for mRNA and enzyme analyses. In Expt 2, thirty-six Sprague-Dawley dams were fed LF until day 9 postpartum when dams were divided into three groups of twelve; one continued to be fed LF, one was fed a moderate-fat diet (MF; 40 % energy as safflower oil); and one was fed a high-fat diet (HF; 67 % energy as safflower oil) diet. At peak lactation (day 15) and post-lactation (day 56), the pancreas was removed for mRNA and enzyme analyses. Expt 1 revealed that lactation and post-lactation significantly (P<0.001) decreased PL mRNA (67 % and 76 %, respectively), but only post-lactation decreased PL activity. Increased dietary fat in Expt 2 significantly increased PL mRNA (LF<MF<HF, P<0.001) and PL activity (LF<MF=HF, P<0.02) in both lactation and post-lactation. In summary, lactation and post-lactation decreased PL mRNA significantly even though dietary fat still regulated PL activity and mRNA in lactation and post-lactation.

Abstract: OBJECTIVE: To study the expression of angiopoietin 1 (Ang1) and angiopoietin 2 (Ang2) in human placentas of dizygotic dichorionic twins in relation to fetal growth. STUDY DESIGN: Placentas from dizygotic-dichorionic twins (n=14) obtained from normal uncomplicated pregnancies were collected immediately after delivery. A quantitative assessment of the placental expression of Ang1 and Ang2 was done using quantitative PCR. Birth weight and anthropometric parameters were measured. Statistical analysis was preformed. RESULTS: Ang1 and Ang2 were expressed in the placentas. We found a significant positive correlation between birth weight and expression of both Ang1 and Ang2 (p<0.009, p<0.011, respectively). In addition, there was a significant positive correlation between skin fold, BMI and Ang1 expression (p<0.0001 and p<0.01, respectively). CONCLUSION: A positive correlation between twin birth weight and placental angiogenesis was found. We suggest that placental expression of Ang1 and Ang2 may have an important role in fetal growth in twin pregnancy.

Abstract: The developmental gene expression of pancreatic lipase (PL) and its related proteins (PLRP1 and PLRP2) is anticoordinate. It is unknown whether dietary fat regulates the expression of these proteins in the preweanling stage. For determining the regulation of development and diet on PL, PLRP1, and PLRP2 as early as the suckling period, pregnant (Sprague-Dawley) rats consumed from day 15 (d15) of pregnancy through d9 of lactation a purified low (11% of energy) safflower oil diet [low-fat (LF)]. From d9 of lactation, dams and their respective pups were fed LF, medium-fat (MF; 40% of energy), or high-fat (HF; 67% of energy) safflower oil diets to d56. Milk fatty acid content had 15- to 100-fold less C:10 and 2.6- to 3.3-fold more C18:2 in MF and HF groups. Diet (LF < MF = HF; P < 0.002), postnatal development (d15 < d21 < d28 = d56; P < 0.001), and interaction of diet x development significantly affected PL activity starting as early as d15. PL mRNA levels showed a parallel effect of diet (LF < HF = MF; P < 0.013) and development (P < 0.001). Both PLRP1 and PLRP2 mRNA levels were significantly affected by development (P < 0.001) and had an anticoordinate pattern compared with PL expression (d15 > d21 > d28). Reported for the first time is the significant down-regulation of PLRP2 mRNA levels by high polyunsaturated fat in suckling (d15) rats. In conclusion, PL and PLRP2 gene expression is regulated anticoordinately by the amount of dietary polyunsaturated fat starting as early as the preweanling phase of development.

Abstract: Pancreatic lipase (PL) and its related protein 1 (PLRP1) are regulated by the amount of dietary fat through an apparent transcriptional mechanism. Regulation of PL and PLRP1 by type of fat (chain length and degree of saturation) is less well understood. The aim of this study was to determine whether medium-chain triglycerides regulate PL and PLRP1. For 7 d, weanling (21-d-old) Sprague Dawley male rats were fed diets low (11% of energy), moderate (40% of energy), or high (67% of energy) in trioctanoate/tridecanoate (MCT) or safflower (low fat only) oils. Food consumption decreased as dietary MCT increased, and the consumption of MCT diets was lower than that of the low-safflower (control) diet. Final body weight was similar among rats fed the low- or moderate-MCT or control diets, but was significantly reduced (17%) in those fed the high-MCT diets. PL activity was significantly elevated 53-60% (p < 0.002) in rats fed low and moderate MCT diets, respectively, compared with that of rats fed high-MCT or control diets. PL and PLRP1 mRNA levels were not significantly different among diets, suggesting that chain length regulates PL and PLRP1 translationally or posttranslationally. The beta-hydroxybutyrate plasma concentration was significantly (p < 0.02) higher (85%) in rats consuming low-MCT diet compared with those of rats fed the control diet. MCT at low levels, but not high levels, increase PL activity without changing its mRNA levels.

Abstract: Leptin expression exhibits developmental and dietary regulation, but it is unknown whether there is an interaction of the regulation by dietary fat and postnatal development. The purpose of this study was to test the effect of different levels of dietary polyunsaturated fat on circulating leptin levels at different post-natal developmental stages. Pregnant (Sprague-Dawley) rats consumed from day 15 of pregnancy through day 9 of lactation a low fat, (11% of energy; LF) polyunsaturated safflower oil diet. From day 9 of lactation, dams and their respective pups were fed low, moderate (40% of energy; MF) or high (67% of energy; HF) polyunsaturated safflower oil diets to full maturation (56 days). Diets were iso-energetic and iso-nitrogenous. Milk fatty acid content reflected the mothers and pups diet, with 15 to 100 fold less C10:0 and 2.6 to 3.3 fold more C18:2 in MF and HF groups compared to LF diet. In newborn rats through post-natal day 56, levels of polyunsaturated fat in mothers' milk and mothers/pups diet had no effect on the levels of circulating leptin. The post-natal development period significantly affected circulating leptin levels (p < 0.001, 15 days = 56 days > 21 days > 28 days). In summary, the developmental postnatal stage regulates leptin levels, independently of the polyunsaturated fat levels in the diet.

Abstract: Production of beta-glucosidase in Aspergillus niger B1 is subjected to catabolic repression by glucose. Aspergillus niger B1 grown on bran as a carbon source secreted beta-glucosidase. The maximum level of the enzyme was reached after 7 d of fermentation. Addition of 1% glucose to the medium suppressed beta-glucosidase production to undetectable levels. In this study, the organic synthesis of a potential inducer of beta-glucosidase production by A. niger B1's reported. Isopropyl-1-thio-beta-D-glucopyranoside (IPTGlc) was synthesized using a two-step organic synthesis protocol. The H-NMR data agreed with those reported previously for the galactoside analog. When IPTGlc was added 24 h after inoculation at a final concentration of 0.4 mM, similar levels of beta-glucosidase were reached 3 to 4 d earlier as compared to fermentation without IPTGlc induction. In practice, this may translate to a more efficient method of producing beta-glucosidase from this fungus.

Abstract: