Kristin Hollung | Nofima - Academia.edu (original) (raw)

Papers by Kristin Hollung

Research paper thumbnail of Lipid degradation and sensory characteristics of M. biceps femoris in dry-cured hams from Duroc using three different processing methods

International Journal of Food Science & Technology, 2014

Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different ... more Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma-style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry-cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three drycuring processes were quite different, the hams 0 lipid profiles, lipid degradation patterns and lipid-associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.

Research paper thumbnail of Leptin – a fatty tissue hormone with many functions

Tidsskrift for Den norske legeforening

ABSTRACT

Research paper thumbnail of Molecular understanding of tenderness: a proteomics approach

Research paper thumbnail of Reduction of leptin gene expression by dietary polyunsaturated fatty acids. J Lipid Res

The Journal of Lipid Research

Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma lept... more Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma leptin concentrations in male smokers. Changes in dietary intake of saturated fatty acids (FA) correlated positively, whereas changes in the intake of PUFA correlated negatively to changes in plasma leptin levels. A 3-week n-3 PUFAenriched diet, as compared with a 3-week lard-enriched diet, induced lower plasma leptin concentration and reduced leptin mRNA expression in rat epididymal adipose tissue. In the human throphoblast cell line (BeWo), n-3 PUFA had a dose-and time-dependent effect on leptin expression. One mM of eicosapentaenoic acid or docosahexaenoic acid (DHA) reduced leptin expression by 71% and 78%, respectively, as compared with control, after 72 h. There was no effect on expression of the signal transducing form of the leptin receptor. In BeWo cells transfected with the human leptin promoter, we found that n-3 PUFA reduced leptin promoter activity; in contrast saturated and monounsaturated FA had no effect on leptin promoter activity. The transcription factors peroxysomal proliferator activated receptor ␥ and sterol regulatory element binding protein-1 mRNAs were reduced after incubation with n-3 PUFA, whereas the expression of CCAAT/enhancer binding protein ␣ was unchanged. DHA-reduced leptin expression was abolished in BeWo cells grown in cholesterol-free medium.

Research paper thumbnail of Genetic Parameters for Growth, Warner Bratzler Shear Force And The Calpain System in Beef

Research paper thumbnail of Effects of low voltage electrical stimulation on bovine longissimus and adductor muscles

... WEN HONG ZHANG,; ZENG QI PENG,; GUANG HONG ZHOU,; XING LIAN XU,; JU QING WU. ... Under rapid ... more ... WEN HONG ZHANG,; ZENG QI PENG,; GUANG HONG ZHOU,; XING LIAN XU,; JU QING WU. ... Under rapid chilling procedures, cold-toughening even occurs in pork (Gigiel and James 1984;Dransfield and Lockyer 1985; Møller and Vestergaard 1987; Taylor and Martoccia 1995). ...

Research paper thumbnail of Analysis of Megavariate Data in Functional Genomics

Comprehensive Chemometrics, 2009

Research paper thumbnail of Effect of Embryo Vitrification on Rabbit Foetal Placenta Proteome during Pregnancy

PLOS ONE, 2015

Very limited information on the post-implantatory effects of vitrification has been published til... more Very limited information on the post-implantatory effects of vitrification has been published till now. We observed in a previous study that the vitrification procedure for the cryopreservation of embryos introduced transcriptomic and proteomic modifications in the rabbit foetal placenta at the middle of gestation. Now, we have conducted a proteomic study to determine whether protein alterations in the foetal placenta induced by the vitrification procedure remain during pregnancy. In this study, we used 2D-DIGE and mass spectrometry (MALDI-TOF-TOF and LC-MS/MS analysis) to identify the protein changes during middle and late stages of gestation (Day 14 and Day 24, respectively) in rabbit foetal placenta. We identified 11 differentially expressed proteins at Day 14 and 13 proteins at Day 24. Data are available via ProteomeXchange with identifiers PXD001840 and PXD001836. In addition, we demonstrate the presence of three proteins, serum albumin, isocitrate dehydrogenase 1 [NADP+], and phosphoglycerate mutase 1, which were altered during pregnancy. We demonstrate the existence of changes in foetal placental protein during pregnancy induced by the vitrification procedure, which brings into question whether vitrification effects observed during foetal development could lead to physiological and metabolic disorders in adulthood. This effect, taken together with other effects reported in the literature, suggests that embryo cryopreservation is not neutral.

Research paper thumbnail of Comprehensive Chemometrics

Research paper thumbnail of Reduction of leptin gene expression by dietary polyunsaturated fatty acids

Journal of lipid research, 2001

Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma lept... more Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma leptin concentrations in male smokers. Changes in dietary intake of saturated fatty acids (FA) correlated positively, whereas changes in the intake of PUFA correlated negatively to changes in plasma leptin levels. A 3-week n-3 PUFA-enriched diet, as compared with a 3-week lard-enriched diet, induced lower plasma leptin concentration and reduced leptin mRNA expression in rat epididymal adipose tissue. In the human trophoblast cell line (BeWo), n-3 PUFA had a dose- and time-dependent effect on leptin expression. One mM of eicosapentaenoic acid or docosahexaenoic acid (DHA) reduced leptin expression by 71% and 78%, respectively, as compared with control, after 72 h. There was no effect on expression of the signal transducing form of the leptin receptor. In BeWo cells transfected with the human leptin promoter, we found that n-3 PUFA reduced leptin promoter activity; in contrast saturated and mo...

Research paper thumbnail of Serum-borne factors in cancer patients with advanced cachexia: influence on adipose cells

Adipobiology, 2009

... CANCER PATIENTS WITH ADVANCED CACHEXIA: INFLUENCE ON ADIPOSE CELLS Fred Haugen1, Kristin Holl... more ... CANCER PATIENTS WITH ADVANCED CACHEXIA: INFLUENCE ON ADIPOSE CELLS Fred Haugen1, Kristin Hollung1, Anne M. Ramsrud1, Andreas J. Wensaas1, Naeem Zahid1, Svein ... e. ell deat or ell s rv val, may depe do t e ala e of pro a da t ap ...

Research paper thumbnail of Lipid degradation and sensory characteristics of M. biceps femoris in dry-cured hams from Duroc using three different processing methods

International Journal of Food Science & Technology, 2014

Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different ... more Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma-style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry-cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three drycuring processes were quite different, the hams 0 lipid profiles, lipid degradation patterns and lipid-associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.

Research paper thumbnail of Enrichment of DNA-binding proteins from crude tissue for electrophoretic mobility shift assay using magnetic phospho cellulose particles

Nucleic Acids Research, 1994

Research paper thumbnail of Eicosapentaenoic acid-induced apoptosis depends on acyl CoA-synthetase

Lipids, 2003

Marine n-3 FA are known to inhibit proliferation or induce cell death in several cancer cell line... more Marine n-3 FA are known to inhibit proliferation or induce cell death in several cancer cell lines. We have previously reported that EPA promotes apoptosis in the lymphoma cell line Ramos, whereas the U-698 cell line is insensitive to EPA. Furthermore, acyl-CoA synthetase (ACS) is expressed to a higher extent in Ramos cells compared to U-698 cells. To investigate the importance of ACS in EPA-induced apoptosis, we incubated Ramos cells with triacsin C, an inhibitor of ACS. This caused a 70% reduction in the amount of cell-associated EPA and diminished activation of EPA. In addition, triacsin C caused a 90% reduction in EPA-induced apoptosis. Several different approaches were tried to overexpress ACS4 in EPA-insensitive lymphoma cell lines, but we did not obtain viable cells with high expression of acyl-CoA activation. However, we show that overexpression of ACS4 in the more robust COS-1 cells caused up to a fivefold increase in activation of EPA and a 67% increase in the amount of cell-associated radiolabeled EPA. Furthermore, we observed 28% elevated cellular level of TAG in EPA-incubated COS-1 cells overexpressing ACS4. The present study provides new information about ACS as an important enzyme for EPA-induced apoptosis in Ramos cells. Our data offer a potential mechanism that may explain the effect of dietary marine n-3 PUFA on growth of certain malignant cells.

Research paper thumbnail of Eicosapentaenoic acid promotes apoptosis in Ramos cells via activation of caspase-3 and -9

Lipids, 2002

Eicosapentaenoic acid (EPA; 20:5n-3) may reduce the cell number in cultured leukemia/lymphoma cel... more Eicosapentaenoic acid (EPA; 20:5n-3) may reduce the cell number in cultured leukemia/lymphoma cells owing to reduced cell proliferation, induction of cell death, or a combination of these processes. EPA has been shown to promote apoptosis in Ramos cells, and our present study was focused on a possible cell cycle arrest and the pathways by which the apoptotic process is induced. Apoptosis may proceed along the intrinsic (mitochondrial) or the extrinsic (death receptor) pathway, which are mediated via different caspases. Caspases are a class of homologous cysteine proteases recognized as pivotal mediators of apoptosis. We investigated whether EPA affects progression of the cell cycle or promotes apoptosis directly. By incorporation of [3H]thymidine and [3H]valine, we showed that DNA, as well as protein synthesis, was reduced after incubation of Ramos cells with EPA for 6 h. We monitored cell cycle distribution by 5-bromo-2'-deoxyuridine staining and observed no cell cycle arrest in the EPA-incubated cells. Incubation of cells with EPA caused PS-flipping, as demonstrated by annexin V-binding (flow cytometry), and cleavage of poly(ADP-ribose) polymerase measured by Western blot analysis. Furthermore, we observed increased activity of caspase-3 and -9, but not of caspase-8. Whereas inhibitors of caspase-3 and -9 reduced EPA-induced apoptosis, inhibition of caspase-8 did not. This suggests that EPA may promote apoptosis via the intrinsic pathway in Ramos cells. Thus, the reduction in cell number can be explained by a direct apoptotic effect of EPA rather than via cell cycle arrest.

Research paper thumbnail of Differential proteomic analysis of drought stress response in leaves of common bean (Phaseolus vulgaris L.)

Journal of Proteomics, 2013

The majority of common bean plants are cultivated under drought conditions. Maintaining crop yiel... more The majority of common bean plants are cultivated under drought conditions. Maintaining crop yields under drought stress is thus one of the biggest challenges facing bean production. In order to improve our understanding of the complex mechanisms involved in the response of common bean (Phaseolus vulgaris) to drought stress, a proteomic approach was used to identify drought-responsive proteins in leaves of two cultivars differing in their response to drought, Tiber and more sensitive Starozagorski čern. 2D-DIGE was used to compare differences in protein abundance between control and stressed plants. Fifty-eight proteins whose abundance changed significantly were identified by LC-MS/MS in Tiber and 64 in Starozagorski čern. The majority of identified proteins were classified into functional categories that include energy metabolism, photosynthesis, ATP interconversion, protein synthesis and proteolysis, stress and defence related proteins. Details of the function of the identified proteins and their abundance profiles in Tiber and Starozagorski are discussed. Interactions between identified proteins were demonstrated by bioinformatics analysis, enabling a more complete insight into biological pathways and molecular functions affected by drought stress. The results form the basis for a further understanding of the biochemical mechanisms of drought response in common bean.

Research paper thumbnail of Retinoic acid dampens LPS-induced NF-κB activity: results from human monoblasts and in vivo imaging of NF-κB reporter mice

The Journal of Nutritional Biochemistry, 2009

Bacterial lipopolysaccharide (LPS) is a major inducer of systemic inflammatory reactions and oxid... more Bacterial lipopolysaccharide (LPS) is a major inducer of systemic inflammatory reactions and oxidative stress in response to microbial infections and may cause sepsis. In the present study, we demonstrate that retinoic acid inhibits LPS-induced activation in transgenic reporter mice and human monoblasts through inhibition of nuclear factor kappaB (NF-kappaB). By using noninvasive molecular imaging of NF-kappaB luciferase reporter mice, we showed that administration of retinoic acid repressed LPS-induced whole-body luminescence, demonstrating in vivo the dynamics of retinoic acid's ability to repress physiologic response to LPS. Retinoic acid also inhibited LPS-induced NF-kappaB activity in the human myeloblastic cell line U937. Retinoic-acid-receptor-selective agonists mimicked - while specific antagonists inhibited - the effects of retinoic acid, suggesting the involvement of nuclear retinoic acid receptors. Retinoic acid also repressed LPS-induced transcription of NF-kappaB target genes such as IL-6, MCP-1 and COX-2. The effect of retinoic acid was dependent on new protein synthesis, was obstructed by a deacetylase inhibitor and was partly eliminated by a signal transducer and activator of transcription-1 (STAT1)/methyltransferase inhibitor, indicating that retinoic acid induces a new protein, possibly STAT1, that is involved in inhibiting NF-kappaB. This provides more evidence for retinoic acid's anti-inflammatory potential, which may have clinical implications in terms of fighting microbial infections.

Research paper thumbnail of Tissue-specific regulation of leptin expression and secretion by all-trans retinoic acid

Journal of Cellular Biochemistry, 2004

In addition to hormones and the sympathetic nervous system, specific nutrients may regulate lepti... more In addition to hormones and the sympathetic nervous system, specific nutrients may regulate leptin mRNA expression and adipose tissue metabolism. However, little is known regarding the effect of nutrients on leptin mRNA expression. Retinoic acid (RA) is a ligand of some nuclear receptors and previous reports have demonstrated contradictory effects on plasma leptin levels. Thus, we examined the effect of RA on expression of leptin in adipocytes of murine and human origin. After 48 h incubation of murine 3T3-L1 adipocytes with 1 and 10 microM all-trans RA, the expression of leptin mRNA was reduced by 56% and 65%, respectively, whereas the secretion of leptin was reduced by 38% and 77%, respectively. In human adipose tissue explants, 1 microM all-trans RA reduced leptin mRNA expression levels by 55% and leptin secretion by 25% after 24 h incubation. We observed an increased mRNA expression level of the transcription factors peroxisomal proliferator activated receptor gamma (PPAR gamma), retinoid X receptor alpha (RXR alpha), and RA receptor alpha (RAR alpha) in 3T3-L1 cells, whereas the mRNA level of these transcription factors was unchanged in human adipose tissue explants after incubation with RA. In two other leptin-expressing cell systems, the human placental trophoblast cell line BeWo and normal human primary osteoblasts, there was no effect of RA on leptin mRNA expression, but leptin secretion was reduced by 64% after 24 h incubation with 10 microM all-trans RA in BeWo cells. In conclusion, all-trans RA reduced both expression and secretion of leptin in human and rodent adipose tissue. In human BeWo cells or primary osteoblasts, leptin mRNA expression levels was not changed by all-trans RA, indicating a tissue-specific regulation of leptin mRNA expression by all-trans RA.

Research paper thumbnail of Evaluation of Nonstarch Polysaccharides and Oligosaccharide Content of Different Soybean Varieties ( Glycine max ) by Near-Infrared Spectroscopy and Proteomics

Journal of Agricultural and Food Chemistry, 2005

A total of 832 samples of soybeans were screened by near-infrared (NIR) reflectance spectroscopy,... more A total of 832 samples of soybeans were screened by near-infrared (NIR) reflectance spectroscopy, to identify soybean samples with a lower content of oligosaccharides and nonstarch polysaccharides (NSP). Of these, 38 samples were identified on the basis of variation in protein content and agronomic value and submitted to high-resolution NIR spectroscopy. On the basis of the NIR data, 12 samples were further selected for chromatographic characterization of carbohydrate composition (mono-, di-, and oligosaccharides and NSP). Their soluble proteins were separated by two-dimensional gel electrophoresis (2DE). Using partial least-squares regression (PLSR), it was possible to predict the content of total NSP from the high-resolution NIR spectra, suggesting that NIR is a suitable and rapid nondestructive method to determine carbohydrate composition in soybeans. The 2DE analyses showed varying intensities of several proteins, including the glycinin G1 precursor. PLSR analysis showed a negative correlation between this protein and insoluble NSP and total uronic acid (UA).

Research paper thumbnail of The combination of glycosaminoglycans and fibrous proteins improves cell proliferation and early differentiation of bovine primary skeletal muscle cells

Differentiation, 2013

Primary muscle cell model systems from farm animals are widely used to acquire knowledge about mu... more Primary muscle cell model systems from farm animals are widely used to acquire knowledge about muscle development, muscle pathologies, overweight issues and tissue regeneration. The morphological properties of a bovine primary muscle cell model system, in addition to cell proliferation and differentiation features, were characterized using immunocytochemistry, western blotting and realtime PCR. We observed a reorganization of the Golgi complex in differentiated cells. The Golgi complex transformed to a highly fragmented network of small stacks of cisternae positioned throughout the myotubes as well as around the nucleus. Different extracellular matrix (ECM) components were used as surface coatings in order to improve cell culture conditions. Our experiments demonstrated improved proliferation and early differentiation for cells grown on surface coatings containing a mixture of both glycosaminoglycans (GAGs) and fibrous proteins. We suggest that GAGs and fibrous proteins mixed together into a composite biomaterial can mimic a natural ECM, and this could improve myogenesis for in vitro cell cultures.

Research paper thumbnail of Lipid degradation and sensory characteristics of M. biceps femoris in dry-cured hams from Duroc using three different processing methods

International Journal of Food Science & Technology, 2014

Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different ... more Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma-style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry-cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three drycuring processes were quite different, the hams 0 lipid profiles, lipid degradation patterns and lipid-associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.

Research paper thumbnail of Leptin – a fatty tissue hormone with many functions

Tidsskrift for Den norske legeforening

ABSTRACT

Research paper thumbnail of Molecular understanding of tenderness: a proteomics approach

Research paper thumbnail of Reduction of leptin gene expression by dietary polyunsaturated fatty acids. J Lipid Res

The Journal of Lipid Research

Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma lept... more Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma leptin concentrations in male smokers. Changes in dietary intake of saturated fatty acids (FA) correlated positively, whereas changes in the intake of PUFA correlated negatively to changes in plasma leptin levels. A 3-week n-3 PUFAenriched diet, as compared with a 3-week lard-enriched diet, induced lower plasma leptin concentration and reduced leptin mRNA expression in rat epididymal adipose tissue. In the human throphoblast cell line (BeWo), n-3 PUFA had a dose-and time-dependent effect on leptin expression. One mM of eicosapentaenoic acid or docosahexaenoic acid (DHA) reduced leptin expression by 71% and 78%, respectively, as compared with control, after 72 h. There was no effect on expression of the signal transducing form of the leptin receptor. In BeWo cells transfected with the human leptin promoter, we found that n-3 PUFA reduced leptin promoter activity; in contrast saturated and monounsaturated FA had no effect on leptin promoter activity. The transcription factors peroxysomal proliferator activated receptor ␥ and sterol regulatory element binding protein-1 mRNAs were reduced after incubation with n-3 PUFA, whereas the expression of CCAAT/enhancer binding protein ␣ was unchanged. DHA-reduced leptin expression was abolished in BeWo cells grown in cholesterol-free medium.

Research paper thumbnail of Genetic Parameters for Growth, Warner Bratzler Shear Force And The Calpain System in Beef

Research paper thumbnail of Effects of low voltage electrical stimulation on bovine longissimus and adductor muscles

... WEN HONG ZHANG,; ZENG QI PENG,; GUANG HONG ZHOU,; XING LIAN XU,; JU QING WU. ... Under rapid ... more ... WEN HONG ZHANG,; ZENG QI PENG,; GUANG HONG ZHOU,; XING LIAN XU,; JU QING WU. ... Under rapid chilling procedures, cold-toughening even occurs in pork (Gigiel and James 1984;Dransfield and Lockyer 1985; Møller and Vestergaard 1987; Taylor and Martoccia 1995). ...

Research paper thumbnail of Analysis of Megavariate Data in Functional Genomics

Comprehensive Chemometrics, 2009

Research paper thumbnail of Effect of Embryo Vitrification on Rabbit Foetal Placenta Proteome during Pregnancy

PLOS ONE, 2015

Very limited information on the post-implantatory effects of vitrification has been published til... more Very limited information on the post-implantatory effects of vitrification has been published till now. We observed in a previous study that the vitrification procedure for the cryopreservation of embryos introduced transcriptomic and proteomic modifications in the rabbit foetal placenta at the middle of gestation. Now, we have conducted a proteomic study to determine whether protein alterations in the foetal placenta induced by the vitrification procedure remain during pregnancy. In this study, we used 2D-DIGE and mass spectrometry (MALDI-TOF-TOF and LC-MS/MS analysis) to identify the protein changes during middle and late stages of gestation (Day 14 and Day 24, respectively) in rabbit foetal placenta. We identified 11 differentially expressed proteins at Day 14 and 13 proteins at Day 24. Data are available via ProteomeXchange with identifiers PXD001840 and PXD001836. In addition, we demonstrate the presence of three proteins, serum albumin, isocitrate dehydrogenase 1 [NADP+], and phosphoglycerate mutase 1, which were altered during pregnancy. We demonstrate the existence of changes in foetal placental protein during pregnancy induced by the vitrification procedure, which brings into question whether vitrification effects observed during foetal development could lead to physiological and metabolic disorders in adulthood. This effect, taken together with other effects reported in the literature, suggests that embryo cryopreservation is not neutral.

Research paper thumbnail of Comprehensive Chemometrics

Research paper thumbnail of Reduction of leptin gene expression by dietary polyunsaturated fatty acids

Journal of lipid research, 2001

Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma lept... more Supplementation with n-3 polyunsaturated fatty acids (PUFA) for 6 weeks did not alter plasma leptin concentrations in male smokers. Changes in dietary intake of saturated fatty acids (FA) correlated positively, whereas changes in the intake of PUFA correlated negatively to changes in plasma leptin levels. A 3-week n-3 PUFA-enriched diet, as compared with a 3-week lard-enriched diet, induced lower plasma leptin concentration and reduced leptin mRNA expression in rat epididymal adipose tissue. In the human trophoblast cell line (BeWo), n-3 PUFA had a dose- and time-dependent effect on leptin expression. One mM of eicosapentaenoic acid or docosahexaenoic acid (DHA) reduced leptin expression by 71% and 78%, respectively, as compared with control, after 72 h. There was no effect on expression of the signal transducing form of the leptin receptor. In BeWo cells transfected with the human leptin promoter, we found that n-3 PUFA reduced leptin promoter activity; in contrast saturated and mo...

Research paper thumbnail of Serum-borne factors in cancer patients with advanced cachexia: influence on adipose cells

Adipobiology, 2009

... CANCER PATIENTS WITH ADVANCED CACHEXIA: INFLUENCE ON ADIPOSE CELLS Fred Haugen1, Kristin Holl... more ... CANCER PATIENTS WITH ADVANCED CACHEXIA: INFLUENCE ON ADIPOSE CELLS Fred Haugen1, Kristin Hollung1, Anne M. Ramsrud1, Andreas J. Wensaas1, Naeem Zahid1, Svein ... e. ell deat or ell s rv val, may depe do t e ala e of pro a da t ap ...

Research paper thumbnail of Lipid degradation and sensory characteristics of M. biceps femoris in dry-cured hams from Duroc using three different processing methods

International Journal of Food Science & Technology, 2014

Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different ... more Hams from Norwegian Duroc pigs, reared and fed identically, were dry-cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma-style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry-cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three drycuring processes were quite different, the hams 0 lipid profiles, lipid degradation patterns and lipid-associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.

Research paper thumbnail of Enrichment of DNA-binding proteins from crude tissue for electrophoretic mobility shift assay using magnetic phospho cellulose particles

Nucleic Acids Research, 1994

Research paper thumbnail of Eicosapentaenoic acid-induced apoptosis depends on acyl CoA-synthetase

Lipids, 2003

Marine n-3 FA are known to inhibit proliferation or induce cell death in several cancer cell line... more Marine n-3 FA are known to inhibit proliferation or induce cell death in several cancer cell lines. We have previously reported that EPA promotes apoptosis in the lymphoma cell line Ramos, whereas the U-698 cell line is insensitive to EPA. Furthermore, acyl-CoA synthetase (ACS) is expressed to a higher extent in Ramos cells compared to U-698 cells. To investigate the importance of ACS in EPA-induced apoptosis, we incubated Ramos cells with triacsin C, an inhibitor of ACS. This caused a 70% reduction in the amount of cell-associated EPA and diminished activation of EPA. In addition, triacsin C caused a 90% reduction in EPA-induced apoptosis. Several different approaches were tried to overexpress ACS4 in EPA-insensitive lymphoma cell lines, but we did not obtain viable cells with high expression of acyl-CoA activation. However, we show that overexpression of ACS4 in the more robust COS-1 cells caused up to a fivefold increase in activation of EPA and a 67% increase in the amount of cell-associated radiolabeled EPA. Furthermore, we observed 28% elevated cellular level of TAG in EPA-incubated COS-1 cells overexpressing ACS4. The present study provides new information about ACS as an important enzyme for EPA-induced apoptosis in Ramos cells. Our data offer a potential mechanism that may explain the effect of dietary marine n-3 PUFA on growth of certain malignant cells.

Research paper thumbnail of Eicosapentaenoic acid promotes apoptosis in Ramos cells via activation of caspase-3 and -9

Lipids, 2002

Eicosapentaenoic acid (EPA; 20:5n-3) may reduce the cell number in cultured leukemia/lymphoma cel... more Eicosapentaenoic acid (EPA; 20:5n-3) may reduce the cell number in cultured leukemia/lymphoma cells owing to reduced cell proliferation, induction of cell death, or a combination of these processes. EPA has been shown to promote apoptosis in Ramos cells, and our present study was focused on a possible cell cycle arrest and the pathways by which the apoptotic process is induced. Apoptosis may proceed along the intrinsic (mitochondrial) or the extrinsic (death receptor) pathway, which are mediated via different caspases. Caspases are a class of homologous cysteine proteases recognized as pivotal mediators of apoptosis. We investigated whether EPA affects progression of the cell cycle or promotes apoptosis directly. By incorporation of [3H]thymidine and [3H]valine, we showed that DNA, as well as protein synthesis, was reduced after incubation of Ramos cells with EPA for 6 h. We monitored cell cycle distribution by 5-bromo-2'-deoxyuridine staining and observed no cell cycle arrest in the EPA-incubated cells. Incubation of cells with EPA caused PS-flipping, as demonstrated by annexin V-binding (flow cytometry), and cleavage of poly(ADP-ribose) polymerase measured by Western blot analysis. Furthermore, we observed increased activity of caspase-3 and -9, but not of caspase-8. Whereas inhibitors of caspase-3 and -9 reduced EPA-induced apoptosis, inhibition of caspase-8 did not. This suggests that EPA may promote apoptosis via the intrinsic pathway in Ramos cells. Thus, the reduction in cell number can be explained by a direct apoptotic effect of EPA rather than via cell cycle arrest.

Research paper thumbnail of Differential proteomic analysis of drought stress response in leaves of common bean (Phaseolus vulgaris L.)

Journal of Proteomics, 2013

The majority of common bean plants are cultivated under drought conditions. Maintaining crop yiel... more The majority of common bean plants are cultivated under drought conditions. Maintaining crop yields under drought stress is thus one of the biggest challenges facing bean production. In order to improve our understanding of the complex mechanisms involved in the response of common bean (Phaseolus vulgaris) to drought stress, a proteomic approach was used to identify drought-responsive proteins in leaves of two cultivars differing in their response to drought, Tiber and more sensitive Starozagorski čern. 2D-DIGE was used to compare differences in protein abundance between control and stressed plants. Fifty-eight proteins whose abundance changed significantly were identified by LC-MS/MS in Tiber and 64 in Starozagorski čern. The majority of identified proteins were classified into functional categories that include energy metabolism, photosynthesis, ATP interconversion, protein synthesis and proteolysis, stress and defence related proteins. Details of the function of the identified proteins and their abundance profiles in Tiber and Starozagorski are discussed. Interactions between identified proteins were demonstrated by bioinformatics analysis, enabling a more complete insight into biological pathways and molecular functions affected by drought stress. The results form the basis for a further understanding of the biochemical mechanisms of drought response in common bean.

Research paper thumbnail of Retinoic acid dampens LPS-induced NF-κB activity: results from human monoblasts and in vivo imaging of NF-κB reporter mice

The Journal of Nutritional Biochemistry, 2009

Bacterial lipopolysaccharide (LPS) is a major inducer of systemic inflammatory reactions and oxid... more Bacterial lipopolysaccharide (LPS) is a major inducer of systemic inflammatory reactions and oxidative stress in response to microbial infections and may cause sepsis. In the present study, we demonstrate that retinoic acid inhibits LPS-induced activation in transgenic reporter mice and human monoblasts through inhibition of nuclear factor kappaB (NF-kappaB). By using noninvasive molecular imaging of NF-kappaB luciferase reporter mice, we showed that administration of retinoic acid repressed LPS-induced whole-body luminescence, demonstrating in vivo the dynamics of retinoic acid's ability to repress physiologic response to LPS. Retinoic acid also inhibited LPS-induced NF-kappaB activity in the human myeloblastic cell line U937. Retinoic-acid-receptor-selective agonists mimicked - while specific antagonists inhibited - the effects of retinoic acid, suggesting the involvement of nuclear retinoic acid receptors. Retinoic acid also repressed LPS-induced transcription of NF-kappaB target genes such as IL-6, MCP-1 and COX-2. The effect of retinoic acid was dependent on new protein synthesis, was obstructed by a deacetylase inhibitor and was partly eliminated by a signal transducer and activator of transcription-1 (STAT1)/methyltransferase inhibitor, indicating that retinoic acid induces a new protein, possibly STAT1, that is involved in inhibiting NF-kappaB. This provides more evidence for retinoic acid's anti-inflammatory potential, which may have clinical implications in terms of fighting microbial infections.

Research paper thumbnail of Tissue-specific regulation of leptin expression and secretion by all-trans retinoic acid

Journal of Cellular Biochemistry, 2004

In addition to hormones and the sympathetic nervous system, specific nutrients may regulate lepti... more In addition to hormones and the sympathetic nervous system, specific nutrients may regulate leptin mRNA expression and adipose tissue metabolism. However, little is known regarding the effect of nutrients on leptin mRNA expression. Retinoic acid (RA) is a ligand of some nuclear receptors and previous reports have demonstrated contradictory effects on plasma leptin levels. Thus, we examined the effect of RA on expression of leptin in adipocytes of murine and human origin. After 48 h incubation of murine 3T3-L1 adipocytes with 1 and 10 microM all-trans RA, the expression of leptin mRNA was reduced by 56% and 65%, respectively, whereas the secretion of leptin was reduced by 38% and 77%, respectively. In human adipose tissue explants, 1 microM all-trans RA reduced leptin mRNA expression levels by 55% and leptin secretion by 25% after 24 h incubation. We observed an increased mRNA expression level of the transcription factors peroxisomal proliferator activated receptor gamma (PPAR gamma), retinoid X receptor alpha (RXR alpha), and RA receptor alpha (RAR alpha) in 3T3-L1 cells, whereas the mRNA level of these transcription factors was unchanged in human adipose tissue explants after incubation with RA. In two other leptin-expressing cell systems, the human placental trophoblast cell line BeWo and normal human primary osteoblasts, there was no effect of RA on leptin mRNA expression, but leptin secretion was reduced by 64% after 24 h incubation with 10 microM all-trans RA in BeWo cells. In conclusion, all-trans RA reduced both expression and secretion of leptin in human and rodent adipose tissue. In human BeWo cells or primary osteoblasts, leptin mRNA expression levels was not changed by all-trans RA, indicating a tissue-specific regulation of leptin mRNA expression by all-trans RA.

Research paper thumbnail of Evaluation of Nonstarch Polysaccharides and Oligosaccharide Content of Different Soybean Varieties ( Glycine max ) by Near-Infrared Spectroscopy and Proteomics

Journal of Agricultural and Food Chemistry, 2005

A total of 832 samples of soybeans were screened by near-infrared (NIR) reflectance spectroscopy,... more A total of 832 samples of soybeans were screened by near-infrared (NIR) reflectance spectroscopy, to identify soybean samples with a lower content of oligosaccharides and nonstarch polysaccharides (NSP). Of these, 38 samples were identified on the basis of variation in protein content and agronomic value and submitted to high-resolution NIR spectroscopy. On the basis of the NIR data, 12 samples were further selected for chromatographic characterization of carbohydrate composition (mono-, di-, and oligosaccharides and NSP). Their soluble proteins were separated by two-dimensional gel electrophoresis (2DE). Using partial least-squares regression (PLSR), it was possible to predict the content of total NSP from the high-resolution NIR spectra, suggesting that NIR is a suitable and rapid nondestructive method to determine carbohydrate composition in soybeans. The 2DE analyses showed varying intensities of several proteins, including the glycinin G1 precursor. PLSR analysis showed a negative correlation between this protein and insoluble NSP and total uronic acid (UA).

Research paper thumbnail of The combination of glycosaminoglycans and fibrous proteins improves cell proliferation and early differentiation of bovine primary skeletal muscle cells

Differentiation, 2013

Primary muscle cell model systems from farm animals are widely used to acquire knowledge about mu... more Primary muscle cell model systems from farm animals are widely used to acquire knowledge about muscle development, muscle pathologies, overweight issues and tissue regeneration. The morphological properties of a bovine primary muscle cell model system, in addition to cell proliferation and differentiation features, were characterized using immunocytochemistry, western blotting and realtime PCR. We observed a reorganization of the Golgi complex in differentiated cells. The Golgi complex transformed to a highly fragmented network of small stacks of cisternae positioned throughout the myotubes as well as around the nucleus. Different extracellular matrix (ECM) components were used as surface coatings in order to improve cell culture conditions. Our experiments demonstrated improved proliferation and early differentiation for cells grown on surface coatings containing a mixture of both glycosaminoglycans (GAGs) and fibrous proteins. We suggest that GAGs and fibrous proteins mixed together into a composite biomaterial can mimic a natural ECM, and this could improve myogenesis for in vitro cell cultures.