QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cha, S. H. Articles by Kagawa, Y. Search for Related Content PubMed PubMed Citation Articles by Cha, S. H. Articles by Kagawa, Y.

---

Articles

Chronic Docosahexaenoic Acid Intake Enhances Expression of the Gene for Uncoupling Protein 3 and Affects Pleiotropic mRNA Levels in Skeletal Muscle of Aged C57BL/6NJcl Mice¹

Seung Hun Cha^*, Akiko Fukushima, Keiko Sakuma and Yasuo Kagawa^*,**2

Departments of ^* Medical Chemistry and Molecular Nutrition, Kagawa Nutrition University, 3–9-21 Chiyoda, Sakado, Saitama, 350-0288, Japan and ^** Department of Biochemistry, Jichi Medical School, Kawachi, Tochigi, 329-0498, Japan

²To whom correspondence should be addressed. E-mail: kagawa{at}eiyo.ac.jp.

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

 
Docosahexaenoic acid [DHA, 22:6(n-3)] prevents cardiovascular disease by decreasing obesity. It also prevents cancer and other geriatric diseases. We studied the chronic pleiotropic effects of DHA on transcription including that of mRNAs for uncoupling proteins (UCP). Male and female mice (9 mo old) were fed high (n-6) or high (n-3) fatty acid diets for 4 mo. Compared with controls fed high (n-6) fatty acid diets [high (n-6) group], the livers of male and female mice fed DHA [high (n-3) group] contained six- (P < 0.001) and fivefold (P < 0.001) more DHA, respectively. The high (n-3) group had less white adipose tissue [35.3% in males (P < 0.001) and 27.3% in females (P < 0.001)]. The high (n-3) group expressed more uncoupling protein 3 (UCP3) in the gastrocnemius, 108% higher (P < 0.001) and 104% higher (P < 0.001) in males and females, respectively, than those in the high (n-6) group. However, the prevention of many diseases by DHA is not explained by UCP3. Thus, the gene expression profiles of both high (n-3) and high (n-6) groups were analyzed in skeletal muscle using cDNA expression array. Of 588 genes surveyed in the array, the high (n-3) group showed 12 genes (2%) including those for glucose regulators (e.g., CD38) and tumor suppressors (e.g., CTCF) that were expressed 100–340% more than those of the high (n-6) group. Furthermore, 28 genes (4.8%), including growth factors (e.g., ErbB-2 receptor) and immune regulators (e.g., interleukin-1 ß precursor) were expressed 50–90% less in the high (n-3) group than in the high (n-6) group. These results explain in part the important pleiotropic effects of DHA, which are independent of obesity control by UCP3 suppression.

KEY WORDS: • DHA • uncoupling protein • array • adipose tissue • obesity • mice

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

 
Fish oil contains (n-3) polyunsaturated fatty acids [(n-3) PUFA]³ such as docosahexaenoic acid [DHA, 22:6(n-3)] and eicosapentaenoic acid [EPA, 20:5(n-3)], which have protective effects against many geriatric disorders (1) including thrombosis (1) and arrhythmias (2) . The cardiovascular diseases may be prevented in part by obesity control via thermogenesis caused by (n-3) PUFA consumption (3) . However, the effects of DHA in preventing senile dementia (4) , tumor growth (5) and allergy (6) are not explained by obesity control. These health benefits of DHA (1 –6) remain controversial, although mediators of both thrombosis (thromboxane A₂) and allergic reactions (leukotriene B₄ and prostaglandin E₂) are inhibited by DHA (6) . We hypothesize that DHA exerts these pleiotropic effects on geriatric diseases via changing expression of genes for many regulators, not only via the acute formation of the above-mentioned autacoids. To confirm our hypothesis, the complicated gene expression was studied by gene arrays as well as quantitative reverse transcription-polymerase chain reaction (RT-PCR) for uncoupling proteins (UCP).

Energy metabolism is the central factor in obesity control. Skeletal muscle plays the largest role in energy consumption. Thus, gene expression was studied in the mouse gastrocnemius muscle. On the other hand, liver is the major center of lipid metabolism and reflects DHA intake; thus, lipids were analyzed in liver. The electron transport chain generates a proton electrochemical potential gradient (µH⁺) (7) , which drives ATP synthase (8) . The µH⁺ is dissipated by proton leakage through UCP and the energy is released as heat (9 ,10) . The gene for UCP1 (called UCP until 1997) has been cloned (11) and it is exclusively expressed in brown adipose tissue (BAT). The deduced amino acid sequences of UCP2 and UCP3 are 55 and 57% identical, respectively, to that of UCP1 (9) . UCP2 is expressed in most tissues at various levels, whereas UCP3 is expressed in skeletal muscle and at low levels in BAT and heart. Two mRNA species of UCP3, UCP3L and its truncated form, UCP3S, have been identified in muscle (12) . The mitochondria of UCP3 knockout mice preserve µH⁺ better than the wild-type mitochondria because of the lack of proton leakage (13) . Two transcription factors, peroxisome proliferator-activated receptor (PPAR) - and PPAR-, are regulated by PUFA (14 ,15) . The PUFA ligands, benzafibrate (16) and BRL49653 (17) , increase the expression of UCP2 and UCP3. We reported increased levels of UCP2 mRNA in the white adipose tissue (WAT) of young diabetic mice fed DHA and EPA (18) .

Because the effects of feeding DHA are not limited to UCP, we used cDNA expression arrays to evaluate gene expression. Because obesity, atherosclerosis, cancer, allergic states and dementia develop in aged animals after a prolonged dietary influence, we fed aged mice DHA for 4 mo [high (n-3) group]. It is essential to analyze such pleiotropic changes in regulators at the same time with a gene array. The gene expression profile of aged mice with and without energy restriction has been reported (19) . Aging causes stress responses and lowers the expression of metabolic and biosynthetic genes (19) . Here we compare the gene expression pattern of mice fed a high (n-3) fatty acid diet with that of those fed a high (n-6) fatty acid diet.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

 
Animal treatment.

Male and female C57BL/6N Jcl mice (48 wk old) purchased from Saitama Experimental Animals (Saitama, Japan) were fed a normal laboratory diet for 7 mo. The diet consisted of the following (g/kg): carbohydrate 54.0, crude fiber 3.2, protein 23.8, lipids 5.1 (palmitate 14.6%, oleate 21.7%, linoleate 45.4%), water 7.8 and minerals and vitamins sufficient to maintain growth. Mice were housed in cages alone or in groups of two. Thereafter, the mice were fed the synthetic diet AIN-76 (20) for 4 mo, containing the following (g/kg): sucrose 150, casein 195, D-glucose 50, DL-methionine 3, -cornstarch 100, ß-cornstarch 300, cellulose 50, lipid 100, mineral mixture 35 (AIN-76), vitamin mixture 10 (AIN-76) and choline bitartrate 7. The mice were exposed to a 12-h light:dark cycle at a constant room temperature and humidity of 25 ± 1°C, and 65 ± 5%, respectively. They were randomly assigned to two groups (n = 7) depending on the administered lipids [high (n-6) group, high (n-3) group]. The diet (5 g/d, kept frozen) was prepared daily to prevent lipid peroxidation; the remaining food was weighed every day, and the weekly diet consumption was calculated.

Four months later, the mice were killed under pentobarbital anesthesia (4 mg/kg body), according to the ethical treatment of animals, and plasma was separated by centrifugation (3000 x g for 15 min). Organs were removed immediately, weighed, frozen in liquid N₂ and stored at -80°C. The BAT was taken from the space between the linea scapularis from the neck height to the upper thoracic region. The WAT was taken from epididymal fat pad. The experimental design was based on our previous experiment (18)

Test lipids.

Both high (n-6) and high (n-3) groups were fed the AIN-76 diet containing 100 g/kg lipid. The high (n-6) group was given a safflower oil and lard diet composed of 323 g/kg oleic acid, 322 g/kg linoleic acid, 183 k/kg palmitic acid, 79 g/kg stearic acid and 15 g/kg linolenic acid (n-3). The (n-6)/(n-3) ratio was 7.04 (gas-liquid chromatography). The high (n-3) group was given a high DHA diet composed of DHA ethylester (DHA-EE) supplemented with soybean oil (500 g/kg) and olive oil (170 g/kg) containing 320 g/kg DHA, 279 g/kg linoleic acid, 225 g/kg oleic acid, 67 g/kg palmitic acid and 15 g/kg EPA. The (n-6)/(n-3) ratio was 0.76. DHA-EE was a gift from Maruha, Tokyo, Japan.

Chemical analyses.

Blood glucose, triacylglycerol (TG) and phospholipid were measured using the Glucose test (o-toluidine boric acid method), Triglycerides G test (GPO, P-chloroform method) and the Phospholipid B test (choline oxidase, phenol method), respectively, as reported previously (18) . All kits were purchased from Wako (Osaka, Japan).

Gas chromatography of liver lipids.

Livers were homogenized in chloroform/methanol (2:1). Lipids were extracted and methylated with HCl/methanol, and fatty acid groups were analyzed by chromatography using a Hitachi G-300 (Hitachi, Tokyo, Japan) essentially as reported (21) . The internal standard was the methylester of 21:0 (0.1 g/L).

Quantitative RT-PCR for mRNA determination.

Total RNA from BAT and gastrocnemius muscle was isolated with the commercial kits, Wako ISOGEN (Wako). The mRNA level was determined using the ABI PRISM 7700 System (PE Applied Biosystems, Foster City, CA) as reported (21) . Oligonucleotide primers and TaqMan probes (Table 1 ) were designed using Primer Express, version 1.0 (PE Applied Biosystems) and the GenBank databases as follows: UCP1 (U63419) (22) , UCP2 (U69135) (23) , UCP3 (AB008216) (14) and 18S rRNA (X00686) (24) . The TaqMan probe consisted of oligonucleotides labeled with a 5'-reporter dye and a downstream, 3'-quencher dye (Table 1) . The RT-PCR reaction was conducted with TaqMan EZ RT-PCR Core Reagents System (PE Applied Biosystems). The RT reaction condition was 55°C for 50 min; the PCR cycle was 95°C for 15s and 58°C for 90s, repeated for 40 cycles. mRNA levels were normalized to the 18S rRNA level in each sample.

Poly (A)⁺ RNA purification and cDNA labeling were conducted with Atlas Pure Total RNA Labeling System (CLONTECH Laboratories, Palo Alto, CA). The Atlas mouse cDNA expression array (CLONTECH Laboratories) was hybridized with ³²P-labeled cDNA probes derived from total RNA from gastrocnemius muscle, as described in the manufacture’s instructions. After hybridization, the array filters were then exposed to phosphor screens overnight and scanned with BAS-2000 PhosphorImager (FUJI film, Tokyo, Japan). Quantitation of expression levels was determined by utilizing ImageQuant analysis program (Array Gauge Ver1.12, FUJI film). Each blot also contained nine housekeeping genes for normalizing the hybridization signals.

Statistical analysis.

Data are expressed as means ± SD. The significance of differences between the high (n-3) and the high (n-6) group was determined using Student’s t test. Males and females were analyzed separately. Statistical significance of difference was defined at a P level < 0.05.

	RESULTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

 
Anthropometric data.

In males and females, body weight was greater (P < 0.001) in the high (n-6) group than in the high (n-3) group (Table 2 ). The WAT of the male high (n-6) group was 54.5% higher (P < 0.001) than that of the high (n-3) group. The livers of the male high (n-3) group weighed 43.0% less (P < 0.001) than those of the high (n-6) group. In the female mice, the WAT weighed 27.3% less (P < 0.001) and liver weighed 34.4% less (P < 0.001) in the high (n-3) group compared with the high (n-6) group (Table 2) .

Plasma glucose concentrations did not differ between the two groups (Table 3 ). Compared with mice fed DHA, the plasma phospholipid concentration in the high (n-6) group was 109% higher in the males (P < 0.001) and 81.7% higher in the females (P < 0.001). Plasma triacylglycerol concentration was greater in females fed the high (n-6) diet than in those fed the high (n-3) diet but males did not differ.

Levels of palmitic (16:0) and stearic acids (18:0) were significantly greater in the high (n-3) groups (P < 0.001) compared with those of the high (n-6) groups (Table 4 ). The (n-3) PUFA levels in the high (n-3) groups were considerably higher than those in the high (n-6) groups; 20:5 (EPA) was 29-fold greater in males (P < 0.001) and 18-fold greater in females (P < 0.001); 22:6 (DHA) was sixfold greater in males (P < 0.001) and fivefold greater in females (P < 0.001). Conversely, monounsaturated fatty acid (MUFA) and (n-6) PUFA levels in the high (n-3) group were lower than those in the high (n-6) group (P < 0.001). Total (n-6) PUFA levels in the high (n-6) groups were threefold those of the high (n-3) groups (P < 0.001). Total MUFA including the oleic acid [18:1 (n-9)] levels were 50% greater (P < 0.001) in the high (n-6) groups compared with those in the high (n-3) groups. Thus, DHA feeding lowered the total (n-6)/total (n-3) ratio (P < 0.001) and increased total (n-6) plus total (n-3) fatty acids (P < 0.001) (Table 4) .

The effects of feeding DHA on mRNA levels of UCP were examined by quantitative RT-PCR. Gastrocnemius UCP-3 mRNA levels were greater (108% in males and 104% in females; P < 0.001) in the high (n-3) groups compared with the high (n-6) groups (Fig. 1C and F). UCP-1 mRNA expression in BAT of the high (n-3) groups compared with the high (n-6) groups was decreased to 70.3% (P < 0.001) in males and to 71.8% (P = 0.06) in females (Fig. 1 A and D). UCP-1 expression was undetectable in the gastrocnemius muscle. Compared with the high (n-6) group, UCP2 data were inconsistent in males and females (Fig. 1 B and E), and WAT UCP-2 mRNA levels were lower in the high (n-3) group (data not shown). BAT UCP-3 mRNA levels were not affected.

View larger version (27K): [in this window] [in a new window]   Figure 1. mRNA of UCP1 (A, D), UCP2 (B, E) and UCP3 (C, F) from BAT and gastrocnemius (Muscle) of aged male and female mice fed high (n-6) or high (n-3) diets for 4 mo. Quantitative RT-PCR was used for the mRNA determination. The results of male (A, B, C) and female mice (D, E, F) are shown separately. Levels of mRNA were calculated as a percentage of the values of the high (n-3) group [mRNA of the high (n-6) group = 100%] and expressed as means ± SD, n = 7. An asterisk indicates that the difference between the groups is significant (P < 0.05, Student’s t test).

The reliability of the data is high, although the processing ability was inferior to that of the high density cDNA macroarray. Of the surveyed genes, 12 (2.0%) were up-regulated in the high (n-3) group by more than twofold [100–300% of the high (n-6) group, n = 6](Table 5 ), whereas 28 (4.8%) genes were down-regulated >50% [10%–50% of the high (n-6) group, n = 6](Table 6 ) in the mice fed DHA. The mRNA for BST-1 (glucose regulator: CD38), transcription factor CTCF (a tumor suppressor gene product), clusterin (antimyocarditis apolipoprotein J), adrenergic receptor 1 and others were up-regulated (Table 5) . Genes related to allergy [e.g., leukemia inhibitory factor (LIF) receptor, monocyte chemoattractant protein 3, gelatinase B, interferon- receptor] and cell growth (FGF4 and ErbB-2 receptor) were down-regulated (Table 6) .

	DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

DHA significantly increased liver saturated fatty acid (SFA) and (n-3) PUFA, and significantly decreased MUFA and (n-6) PUFA. Endogenous (n-3) PUFA are derived from 18:3(n-3), whereas (n-6) PUFA are derived from 18:2(n-6) by elongation and desaturation (25 ,26) . The metabolic pathways for these two families use the same elongation and desaturation enzymes. The elongation and desaturation of 18:2(n-6) were significantly inhibited by DHA, whereas ß-oxidation was activated. As a result, 18:2(n-6) and 20:4(n-6) levels were significantly lower and SFA were significantly greater in the high (n-3) group (Table 4 ).

The concentration of DHA in the livers of aged control rats was significantly lower than that in young control rats (27) . The synthesis of DHA and EPA from 18:3(n-3) was decreased by age to a greater extent than that of 20:4(n-6) from 18:2(n-6) and thus, exogenous DHA supplementation should help to prevent many pathological conditions.

One of the authors previously reported that dietary (n-3) PUFA more effectively reduced liver TG concentrations than linoleic acid or -linolenic acid in diabetic mice (18) . The concentration of serum phospholipid was lower in the high (n-3) group (Table 3) . Serum phospholipid is distributed mainly in the HDL fraction. Because HDL cholesterol levels were lower in the (n-3) groups (data not shown), it is conceivable that serum phospholipid was decreased concomitantly with the reduction of HDL. The decreases in the body weight and WAT weight in the high (n-3) group (Table 2) are attributable to the lower activities of cytosolic fatty acid synthase and its related enzymes in mice fed DHA than in those fed linoleic acid (28) . Fish oil enhanced the increased fatty acid oxidation rate by 150% in mitochondria and by 300% in peroxisomes (29) . In the livers of rats fed fish oil, mRNA levels of the fatty acid catabolizing enzymes are increased, whereas those of the fatty acid anabolizing enzymes are decreased (29) .

Regulation of UCP gene expression by DHA in aged mice.

The increase in the fatty acid oxidation and mRNA levels of the responsible enzymes, such as acyl-CoA oxidase (28 ,29) must be accompanied by an increase in the mRNA levels of the UCP that consume energy via thermogenesis (9 ,10 ,30 ,31) . UCP1 is characterized as the key uncoupling protein in BAT mitochondria (10) , whereas details concerning UCP2 and UCP3 are unknown (9) . Tissues that express UCP3 abundantly are skeletal muscle and brown fat, and the relative lack of expression in the other sites is consistent with the role of UCP3 as a mediator of thermogenesis (32) . The UCP3 knockout mice contain tightly coupled mitochondria that leak fewer protons (13) . Mice overexpressing UCP3 in skeletal muscle are hyperphagic and lean (33) . Despite this direct evidence, the role of UCP3 remains controversial and requires further elucidation (34) .

The present study found that DHA alters the expression of UCP in various tissues (Fig. 1) . Compared with the high (n-6) group, skeletal muscle UCP2, UCP3 and BAT UCP2 mRNA levels generally were up-regulated in the high (n-3) group, whereas WAT UCP2 (data not shown) and BAT UCP1 mRNA were down-regulated. Skeletal muscle represents up to 40% of the total body weight and it is endowed with substantial mitochondrial capacity. Therefore, the 100% increase in muscle UCP3 mRNA (Fig. 1) may be important in the maintenance of normal energy metabolism and blood glucose levels.

The expression of UCP will prevent diabetes and obesity (34) , and these conditions are in fact prevented by respiratory uncoupling in the skeletal muscle of transgenic mice (35) . As fuels are combusted in the mitochondria, electron flow in the electron transport chain drives outward proton pumping, thus forming a proton motive force (µH⁺) with concomitant O₂ consumption (8) . The µH⁺ then drives proton flux inward through F₁F₀ ATP synthase during ATP formation (9 ,34) .

In the WAT of diabetic mice (12 wk old) fed fish oil, UCP2 mRNA expression was enhanced (18) . However, BAT UCP1 (Fig. 1) and WAT UCP2 of aged mice (98 wk old; data not shown) were significantly decreased by DHA. Because total energy consumption decreases with age, more thermogenesis is required in muscle of aged mice.

The effects of DHA appear to be mediated by PPAR. PPAR and PPAR play key roles in the catabolism and storage of fatty acids, respectively (36 ,37) . The PPAR subtype appears to play a primary role in the storage of lipids in WAT, BAT and skeletal muscle (36) . Moreover, the PPAR-specific thiazolidinedione ligand up-regulates UCP3 gene expression in WAT (37) . More importantly, the induction of UCP3 with fish oil is associated with the induction of peroxisomal acyl-CoA oxidase and a 25% reduction in body fat (38) . The reduction of energy coupling was confirmed by in vivo nuclear magnetic resonance (39) . In conclusion, the increased expression of UCP3 mRNA (Fig. 1) may explain the lower WAT weight of the high (n-3) group compared with the high (n-6) group (Table 2 ) because of the increased energy consumption.

Pleiotropic gene expression induced by DHA analyzed using the array.

DHA suppresses allergies (7) , cancer (6) and thrombosis. These effects are not explained by the energy expenditure enhanced by the increased mRNA levels for UCP3 (Fig. 1) and of increased levels of enzymes involved in lipid catabolism (37 ,39 ,40) .

Thromboxane A₂, leukotriene B₄ and prostaglandin E₂ are decreased by DHA (6) but the duration of these effects is short. Although complicated effects of dietary restriction on gene expression (6346 genes) in aged mice have been reported (19) , the effects of DHA on the expression of genes related to allergies and cancer in aged mice are reported here for the first time. The mRNAs causing these effects were surveyed using the cDNA expression array (Tables 5 , 6) . If the 100% increase in expression of UCP3 is important, then the 100–300% increases and 10–50% decreases of gene expression in the high (n-3) group compared with the high (n-6) group on array should also be taken into consideration. The increased expression of BST-1 in the high (n-3) group is of interest because DHA prevents hyperglycemia (18) and BST-1 (CD38: ADP-ribosyl cyclase) is important in glucose metabolism (41) . In fact, CD38 is lost in obese mice (41) . The increased expression of the CTCF gene may be related to the antitumor effect of DHA because CTCF is a multifunctional transcription factor encoded by a tumor suppressor gene (42) that is one of the p53 response genes (43) . Clusterin (or apolipoprotein J) is one factor that limits the severity of autoimmune myocarditis; thus its increase may prevent immune reactions (44) .

The decreased expression of genes for LIF receptor, monotype chemoattractant protein 3 and interferon- receptor may be related to the antiallergic effects of DHA. For example, proinflammatory cytokines are important factors in the regulation of skeletal muscle function (45) . A decrease in ErbB2 (a protein tyrosine kinase) expression may reduce cell proliferation. In addition, lowered ErbB2 expression may be due to the overexpression of UCP3, which enhances thermogenesis and thus lowers myofibril ErbB2 expression via acetylcholine receptor–dependent muscle activity to compensate for thermogenesis (46) . Gelatinase B is secreted during the migratory phase of human and murine muscle cells (47) . LIF is also a member of the cytokine family of growth factors that promote myoblast proliferation (48) .

These pleiotropic effects of DHA might be mediated by large changes in hepatic lipid composition (Table 4) and an increase in UCP3 (Fig. 1) via activation of the PPAR- system with resulting changes in plasma phospholipids (Table 3) and WAT weight reduction (Table 2) . However, the biological roles of most of the 588 genes in the array are not firmly established. This report is the first step; detailed analyses constitute the next step required to elucidate the pleiotropic effects of DHA.

	ACKNOWLEDGMENTS

 
We are grateful to Maruha (Tokyo, Japan) for the gift of DHA-EE.

	FOOTNOTES

 
¹ Supported by grants in Aid for High Technology Research Center from the Ministry of Education, Science and Culture of Japan.

³ Abbreviations used: BAT, brown adipose tissue; µH⁺, electrochemical potential difference of proton across the inner mitochondrial membrane; DHA, docosahexaenoic acid [22:6(n-3)]; DHA-EE, docosahexaenoic acid ethyl ester; EPA, eicosapentaenoic acid [20:5(n-3)]; LIF, leukemia inhibitory factor; MUFA; monounsaturated fatty acid; PPAR, peroxisome proliferator-activated receptor; PUFA, polyunsaturated fatty acid; RT-PCR, reverse transcription-polymerase chain reaction; SFA, saturated fatty acid; TG, triacylglycerol; UCP, uncoupling protein; WAT, white adipose tissue.

Manuscript received March 29, 2001. Initial review completed May 14, 2001. Revision accepted July 9, 2001.

	LITERATURE CITED

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION LITERATURE CITED

 

1. Horrocks L. A. & Yeo Y. K. (1999) Health benefits of docosahexaenoic acid (DHA). Pharmacol. Res. 40:211-225.[Medline]

2. Siscovick D. S., Raghunathan T., King I., Weinmann S., Bovbjerg V. E., Kushi L., Cobb L. A., Copass M. K., Psaty B. M., Lemaitre R., Retzlaff B. & Knopp R. H. (2000) Dietary intake of long chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Am. J. Clin. Nutr. 71((suppl. 1)):208S-212S.[Abstract/Free Full Text]

3. Oudart H., Groscolas R., Calgari C., Nibbelink M., Leray C., Maho Y. L. & Malan A. (1997) Brown fat thermogenesis in rats fed high-fat diets enriched with n-3 polyunsaturated fatty acids. Int. J. Obes. Relat. Metab. Disord. 21:955-962.[Medline]

4. Kalmijn S. (2000) Fatty acid intake and the risk of dementia and cognitive decline: a review of clinical and epidemiological studies. J. Nutr. Health Aging 4:202-207.[Medline]

5. Rose D. P., Connolly J. M., Rayburn J. & Coleman M. (1995) Influence of diets containing eicosapentaenoic or docosahexaenoic acid on growth and metastasis of breast cancer cells in nude mice. J. Natl. Cancer Inst. 87:587-592.[Abstract/Free Full Text]

6. Kelley D. S., Taylor P. C., Nelson G. J., Schmidt P. C., Ferretti A., Erickson K. L., Yu R., Chandra P. K. & Mackey B. E. (1999) Docosahexaenoic acid ingestion inhibits natural killer cell activity and production of inflammatory mediators in young healthy men. Lipids 34:317-324.[Medline]

7. Mitchell P. (1979) Keilin’s respiratory chain concept and its chemiosmotic consequences. Science (Washington DC) 206:1148-1159.[Free Full Text]

8. Boyer P. D. (1997) The ATP synthase—a splendid molecular machine. Annu. Rev. Biochem. 66:717-749.[Medline]

9. Boss O., Hagen T. & Lowell B. B. (2000) Uncoupling proteins 2 and 3: potential regulators of mitochondrial energy metabolism. Diabetes 49:143-156.[Abstract]

10. Klingenberg M. & Huang S. G. (1999) Structure and function of the uncoupling protein from brown adipose tissue. Biochim. Biophys. Acta 1415:271-296.[Medline]

11. Bouillaud F., Weissenbach J. & Ricquier D. (1986) Complete cDNA-derived amino acid sequence of rat brown fat uncoupling protein. J. Biol. Chem. 261:1487-1490.[Abstract/Free Full Text]

12. Solanes G., Vidal-Puig A., Grujic D., Flier J. S. & Lowell B. B. (1997) The human uncoupling protein-3 gene. Genomic structure, chromosomal localization, and genetic basis for short and long form transcripts. J. Biol. Chem. 272:25433-25436.[Abstract/Free Full Text]

13. Vidal-Puig A., Grujic D., Zhang C. Y., Hagen T., Boss O., Ido Y., Szczepanik A., Wade J., Mootha V., Cortright R., Muoio D. M. & Lowell B. B. (2000) Energy metabolism in uncoupling protein 3 gene knockout mice. J. Biol. Chem. 275:16258-16266.[Abstract/Free Full Text]

14. Boss O., Bobbioni-Harsch E., Assimacopoulos-Jeannet F., Muzzin P., Munger R., Giacobino J. P. & Golay A. (1998) Uncoupling protein-3 expression in skeletal muscle and free fatty acids in obesity. Lancet 351:1933.[Medline]

15. Kliewer S. A., Sundseth S. S., Jones S. A., Brown P. J., Wisely G. B., Koble C. S., Devchand P., Wahli W., Willson T. M., Lenhard J. M. & Lehmann J. M. (1997) Fatty acids and eicosanoids regulate gene expression through direct interactions with peroxisome proliferator-activated receptors and . Proc. Natl. Acad. Sci. U.S.A. 94:4318-4323.[Abstract/Free Full Text]

16. Cabrero A., Llaverias G., Roglans N., Alegret M., Sanchez R., Adzet T., Laguna J. C. & Vazquez M. (1999) Uncoupling protein-3 mRNA levels are increased in white adipose tissue and skeletal muscle of benzafibrate-treated rats. Biochem. Biophys. Res. Commun. 260:547-556.[Medline]

17. Viguerie-Bascands N., Saulnier-Blache J. S., Dandine M., Dauzats M., Daviaud D. & Langin D. (1999) Increase in uncoupling protein-2 mRNA expression by BRL49653 and bromopalmitate in human adipocytes. Biochem. Biophys. Res. Commun. 256:138-141.[Medline]

18. Cha S. H., Hasegawa K., Kawabata T., Kato M., Shimokawa T. & Kagawa Y. (1999) Increased uncoupling protein2 mRNA in white adipose tissue, and decrease in leptin, visceral fat, blood glucose, and cholesterol in KK-A^y mice fed with eicosapentaenoic and docosahexaenoic acids in addition to linolenic acid. Biochem. Biophys. Res. Commun. 259:85-90.[Medline]

19. Lee C. K., Klopp R. G., Weindruch R. & Prolla T. A. (1999) Gene expression profile of aging and its retardation by caloric restriction. Science (Washington DC) 285:1390-1393.[Abstract/Free Full Text]

20. American Institute of Nutrition (1977) Report of the American Institute of Nutrition ad hoc committee on standards for nutritional studies. J. Nutr. 107:1340-1348.

21. Shimokawa T., Kato M., Ezaki O. & Hashimoto S. (1998) Transcriptional regulation of muscle-specific genes during myoblast differentiation. Biochem. Biophys. Res. Commun. 246:287-292.[Medline]

22. Palmieri F. (1994) Mitochondrial carrier proteins. FEBS Lett 346:48-54.[Medline]

23. Fleury C., Neverova M., Collins S., Raimbault S., Champigny O., Levi-Meyrueis C., Bouillaud F., Seldin M. F., Surwit R. S., Ricquier D. & Warden C. H. (1997) Uncoupling protein-2: a novel gene linked to obesity and hyperinsulinemia. Nat. Genet. 15:269-272.[Medline]

24. Raynal F., Michot B. & Bachellerie J. P. (1984) Complete nucleotide sequence of mouse 18S rRNA gene: comparison with other available homologs. FEBS Lett 167:263-268.[Medline]

25. Simopoulos A. P. (1991) Omega-3 fatty acids in health and disease and in growth and development. Am. J. Clin. Nutr. 54:438-463.[Abstract/Free Full Text]

26. Spector A. A. (1999) Essentiality of fatty acids. Lipids 34:S1-S3.

27. Youdim K. A. & Deans S. G. (1999) Beneficial effects of thyme oil on age-related changes in the phospholipid C20 and C22 polyunsaturated fatty acid composition of various rat tissues. Biochim. Biophys. Acta 1438:140-146.[Medline]

28. Ikeda I., Cha J. Y., Yanagita T., Nakatani N., Oogami K., Imaizumi K. & Yazawa K. (1998) Effects of dietary -linolenic, eicosapentaenoic and docosahexaenoic acids on hepatic lipogenesis and ß-oxidation in rats. Biosci. Biotechnol. Biochem. 62:675-680.[Medline]

29. Ide T., Kobayashi H., Ashakumary L., Rouyer I. A., Takahashi Y., Aoyama T., Hashimoto T. & Mizugaki M. (2000) Comparative effects of perilla and fish oils on the activity and gene expression of fatty acid oxidation enzymes in rat liver. Biochim. Biophys. Acta 1485:23-35.[Medline]

30. Bao S., Kennedy A., Wojciechowski B., Wallance P., Ganaway E. & Garvey W. T. (1998) Expression of mRNAs encoding uncoupling proteins in human skeletal muscle: effects of obesity and diabetes. Diabetes 47:1935-1940.[Abstract]

31. Adams S. H. (2000) Uncoupling protein homologs: emerging views of physiological function. J. Nutr. 130:711-714.[Abstract/Free Full Text]

32. Gong D. W., He Y., Karas M. & Reitman M. (1997) Uncoupling protein-3 is a mediator of thermogenesis regulated by thyroid hormone, ß 3-adrenergic agonists, and leptin. J. Biol. Chem. 272:24129-24132.[Abstract/Free Full Text]

33. Clapham J. C., Arch J. R., Clapman H., Haynes A., Lister C., Moore G. B., Piercy V., Carter S. A., Lehner I., Smith S. A., Beeley L. J., Godden R. J., Herrity N., Skehel M., Changani K. K., Hockings P. D., Reid D. G., Squires S .M., Hatcher J., Trail B., Latcham J., Rastan S., Harper A. J., Cadenas S., Buckingham J. A., Brand M. D. & Abuin A. (2000) Mice overexpressing human uncoupling protein-3 in skeletal muscle are hyperphagic and lean. Nature (Lond.) 406:415-418.[Medline]

34. Kagawa Y., Cha S. H., Hasegawa K., Hamamoto T. & Endo H. (1999) Regulation of energy metabolism in human cells in aging and diabetes: F₀F₁, mtDNA, UCP, and ROS. Biochem. Biophys Res. Commun. 266:662-676.[Medline]

35. Li B., Nolte L. A., Ju J. S., Han D. H., Coleman T., Holloszy J. O. & Semenkovich C. F. (2000) Skeletal muscle respiratory uncoupling prevents diet-induced obesity and insulin resistance in mice. Nat. Med. 6:1115-1120.[Medline]

36. Kelly L. J., Vicario P. P., Thompson G. M., Candelore M. R., Doebber T. W., Ventre J., Wu M. S., Meurer R., Forrest M. J., Conner M. W., Cascieri M. A. & Moller D. E. (1998) Peroxisome proliferator-activated receptors gamma and alpha mediate in vivo regulation of uncoupling protein (UCP-1, UCP-2, UCP-3) gene expression. Endocrinology 139:4920-4927.[Abstract/Free Full Text]

37. Matsuda J., Hosoda K., Ito H., Son C., Doi K., Hanaoka I., Inoue G., Nishimura H., Yoshimasa Y., Yamori Y., Odaka H. & Nakao K. (1998) Increased adipose expression of the uncoupling protein-3 gene by thiazolidinediones in Wistar fatty rats and in cultured adipocytes. Diabetes 47:1809-1814.[Abstract]

38. Baillie R. A., Takada R., Nakamura M. & Clarke S. D. (1999) Coordinate induction of peroxisomal acyl-CoA oxidase and UCP-3 by dietary fish oil: a mechanism for decreased body fat deposition. Prostaglandins Leukot. Essent. Fatty Acids 60:351-356.[Medline]

39. Jucker B. M., Dufour S., Ren J., Cao X., Previs S. F., Underhill B., Cadman K. S. & Shulman G. I. (2000) Assessment of mitochondrial energy coupling in vivo by. ¹³C/³¹P NMR. Proc. Natl. Acad. Sci. U.S.A. 97:6880-6884.[Abstract/Free Full Text]

40. Clarke S. D. (2000) Polyunsaturated fatty acid regulation of gene transcription: a mechanism to improve energy balance and insulin resistance. Br. J. Nutr. 83:S59-S66.

41. Takasawa S., Akiyama T., Nata K., Kuroki M., Tohgo A., Noguchi N., Kobayashi S., Kato I., Katada T. & Okamoto H. (1998) Cyclic ADP-ribose and inositol 1,4,5-trisphosphate as alternate second messengers for intracellular Ca²⁺ mobilization in normal and diabetic ß-cells. J. Biol. Chem. 273:2497-2500.[Abstract/Free Full Text]

42. Klenova E. M., Fagerlie S., Filippova G. N., Kretzner L., Goodwin G. H., Loring G., Neiman P. E. & Lobanenkov V. V. (1998) Characterization of the chicken CTCF genomic locus, and initial study of the cell cycle-regulated promoter of the gene. J. Biol. Chem. 273:26571-26579.[Abstract/Free Full Text]

43. Kostic C. & Shaw P. H. (2000) Isolation and characterization of sixteen novel p53 response genes. Oncogene 19:3978-3987.[Medline]

44. McLaughlin L., Zhu G., Mistry M., Ley-Ebert C., Stuart W. D., Florio C. J., Groen P. A., Witt S. A., Kimball T. R., Witte D. P., Harmony J. A. & Aronow B. J. (2000) Apolipoprotein J/clusterin limits the severity of murine autoimmune myocarditis. J. Clin. Investig. 106:1105-1113.[Medline]

45. Zhang Y., Pilon G., Marette A. & Baracos V. E. (2000) Cytokines and endotoxin induce cytokine receptors in skeletal muscle. Am. J. Physiol. Endocrinol. Metab. 279:E196-E205.[Abstract/Free Full Text]

46. Altiok N., Bessereau J. L. & Changeux J. P. (1995) ErbB3 and ErbB2/neu mediate the effect of heregulin on acetylcholine receptor gene expression in muscle: differential expression at the endplate. EMBO J 14:4258-4266.[Medline]

47. Lewis M. P., Tippett H. L., Sinanan A. C., Morgan M. J. & Hunt N. P. (2000) Gelatinase-B (matrix metalloproteinase-9; MMP-9) secretion is involved in the migratory phase of human and murine muscle cell cultures. J. Muscle Res. Cell Motil. 2 1:223-233.

48. Bower J., Vakakis N., Nicola N. A. & Austin L. (1995) Specific binding of leukemia inhibitory factor to murine myoblasts in culture. J. Cell Physiol. 164:93-98.[Medline]

This article has been cited by other articles:

				D. R Jacobs Jr, D. Sluik, M. H Rokling-Andersen, S. A Anderssen, and C. A Drevon Association of 1-y changes in diet pattern with cardiovascular disease risk factors and adipokines: results from the 1-y randomized Oslo Diet and Exercise Study Am. J. Clinical Nutrition, February 1, 2009; 89(2): 509 - 517. [Abstract] [Full Text] [PDF]

				L. Belayev, V. L. Marcheselli, L. Khoutorova, E. B. Rodriguez de Turco, R. Busto, M. D. Ginsberg, and N. G. Bazan Docosahexaenoic Acid Complexed to Albumin Elicits High-Grade Ischemic Neuroprotection Stroke, January 1, 2005; 36(1): 118 - 123. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cha, S. H. Articles by Kagawa, Y. Search for Related Content PubMed PubMed Citation Articles by Cha, S. H. Articles by Kagawa, Y.