Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures

BACKGROUND: Lycium barbarum (also called wolfberry), a famous Chinese traditional medicine and food ingredient, is well recognized for its significant role in preventing obesity; however, the molecular mechanisms underlying its preventive effects on fat accumulation are not well understood yet. The aim of this study was to determine the effects and mechanism of Lycium barbarum polysaccharides (LBP) on the proliferation and differentiation of 3T3-L1 preadipocytes. MTT was used to detect the proliferation of 3T3-Ll preadipocytes. Oil red O staining and colorimetric analysis were used to detect cytosolic lipid accumulation during 3T3-L1 preadipocyte differentiation. Real-time fluorescent quantitative PCR (qPCR) technology was used to detect peroxisome proliferator-activated receptor c (PPARc), CCAAT/enhancer-binding protein a (C/EBPa), adipocyte fatty-acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL) expression. RESULTS: The concentration of LBP from 25 to 200 lg/mL showed a tendency to inhibit the growth of preadipocytes at 24 h, and it inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. In the preadipocytes treated with 200 lg/mL LBP, there were reduced lipid droplets in the cytoplasm, and its effect was opposite to that of rosiglitazone (ROS), which significantly reduced the PPARc, C/EBPa, aP2, FAS, and LPL mRNA expression of adipocytes. CONCLUSIONS: LBP exerts inhibitive effects on the proliferation and differentiation of 3T3-L1 preadipocytes and decreases the cytoplasm accumulation of lipid droplets during induced differentiation of preadipocytes toward mature cells. Above phenomenon might link to lowered expression of PPARc, C/EBPa, aP2, FAS, and LPL after LBP treatment. Thus, LBP could serve as a potential plant extract to treat human obesity or improve farm animal carcass quality via adjusting lipid metabolism.

mRNA transcription and protein expression of PPARgamma, FAS, and HSL in different parts of the carcass between fat-tailed and thin-tailed sheep

Background The objective of this study was to compare the level differences of mRNA transcription and protein expression of PPARγ, FAS and HSL in different parts of the carcass in different tail-type sheep. Six Tan sheep and six Shaanbei fine-wool sheep aged 9 months were slaughtered and samples were collected from the tail adipose, subcutaneous adipose, and longissimus dorsi muscle. The levels of mRNA transcription and protein expression of the target genes in these tissues were determined by real-time quantitative PCR and western blot analyses. Results The results showed that PPARγ, FAS, and HSL were expressed with spatial differences in tail adipose, subcutaneous adipose and longissimus dorsi muscle of Tan sheep and Shaanbei fine-wool sheep. Differences were also observed between the two breeds. The mRNA transcription levels of these genes were somewhat consistent with their protein expression levels. Conclusion The present results indicated that PPARγ, FAS and HSL are correlated with fat deposition, especially for the regulating of adipose deposition in intramuscular fat, and that the mRNA expression patterns are similar to the protein expression patterns. The mechanism requires clarification in further studies.

PPARgamma FAS, HSL mRNA and protein expression during Tan sheep fat-tail development

Background The objective of this study was to investigate proliferator-activated receptor (PPARγ), fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) mRNA and protein expression in fat tails of Tan sheep. Rams from different developmental stages (aged 3, 6, 9, 12, 15 and 18 months) were selected, and their tail measurements including length (L), width (W) and girth (G) were recorded. The mRNA and protein expressions of PPARγ, FAS and HSL were examined by quantitative real-time polymerase chain reaction (PCR) and Western blot. Results The tail measurements increased with age. We observed no significant differences (P > 0.05) of PPARγ mRNA expression between ages 9 and 15 months, and between 12 and 15 months; FAS mRNA expression levels at each developmental stage were observed significantly in Tan sheep (P < 0.05); HSL mRNA expression with no significant differences were only observed between 6 and 15 months (P > 0.05). Significant differences (P < 0.05) of PPARγ, FAS and HSL protein expressions at each developmental stage were observed in Tan sheep. Conclusion We observed that the mRNA expression patterns of PPARγ and FAS decreased first before they increased again and then this process repeated. Conversely, the mRNA expression patterns of HSL increased first before they decreased and then this process repeated. The protein expression patterns of PPARγ and FAS decreased first before they increased again and then this process repeated. Conversely, the protein expression pattern of HSL increased first before it decreased again and then increased again.