The fasting-refeeding perturbation has been used extensively to reveal specific genes and metabolic pathways that control energy metabolism in the chicken. Most global transcriptional scans of the ...fasting-refeeding response in liver have focused on juvenile chickens that were 1, 2 or 4 weeks old. The present study was aimed at the immediate post-hatch period, in which newly-hatched chicks were subjected to fasting for 4, 24 or 48 h, then refed for 4, 24 or 48 h, and compared with a fully-fed control group at each age (D1-D4).
Visual analysis of hepatic gene expression profiles using hierarchical and K-means clustering showed two distinct patterns, genes with higher expression during fasting and depressed expression upon refeeding and those with an opposing pattern of expression, which exhibit very low expression during fasting and more abundant expression with refeeding. Differentially-expressed genes (DEGs), identified from five prominent pair-wise contrasts of fed, fasted and refed conditions, were subjected to Ingenuity Pathway Analysis. This enabled mapping of analysis-ready (AR)-DEGs to canonical and metabolic pathways controlled by distinct gene interaction networks. The largest number of hepatic DEGs was identified by two contrasts: D2FED48h/D2FAST48h (968 genes) and D2FAST48h/D3REFED24h (1198 genes). The major genes acutely depressed by fasting and elevated upon refeeding included ANGTPL, ATPCL, DIO2, FASN, ME1, SCD, PPARG, SREBP2 and THRSPA-a primary lipogenic transcription factor. In contrast, major lipolytic genes were up-regulated by fasting or down-regulated after refeeding, including ALDOB, IL-15, LDHB, LPIN2, NFE2L2, NR3C1, NR0B1, PANK1, PPARA, SERTAD2 and UPP2.
Transcriptional profiling of liver during fasting/re-feeding of newly-hatched chicks revealed several highly-expressed upstream regulators, which enable the metabolic switch from fasted (lipolytic/gluconeogenic) to fed or refed (lipogenic/thermogenic) states. This rapid homeorhetic shift of whole-body metabolism from a catabolic-fasting state to an anabolic-fed state appears precisely orchestrated by a small number of ligand-activated transcription factors that provide either a fasting-lipolytic state (PPARA, NR3C1, NFE2L2, SERTAD2, FOX01, NR0B1, RXR) or a fully-fed and refed lipogenic/thermogenic state (THRSPA, SREBF2, PPARG, PPARD, JUN, ATF3, CTNNB1). THRSPA has emerged as the key transcriptional regulator that drives lipogenesis and thermogenesis in hatchling chicks, as shown here in fed and re-fed states.
The thyroid hormone responsive spot 14α (THRSPα) gene plays important roles in chicken growth and fat deposition. The aim of this study was to identify new variations in the gene to determine their ...effects on growth and fat traits in chicken and to observe the effects of the THRSPα gene on chicken lipid profile and lipoprotein and glucose and triiodothyronine effects on the THRSPα expression in liver and fat cells. Two new variations, namely A197835978G and G197836086A, and a reported 9-bp insertion-deletion (indel) of the THRSPα gene were genotyped by single-stranded conformational polymorphism in a Xinghua x White Recessive Rock F₂ full-sib resource population. The results showed that the A197835978G was significantly associated with hatch weight and BW at 28 d of age and breast muscle weight at 90 d of age in chickens (P < 0.05). The G197836086A was significantly associated with cingular fat width (P = 0.0349) and breast muscle crude fat content (P = 0.0349). The indel was significantly associated with abdominal fat weight (P = 0.0445). The above new THRSPα polymorphisms were also significantly associated with the total cholesterol and low-density lipoprotein, in which the THRSPα GA/AG genotype was associated with lipid and lipoprotein and the THRSPα BB indel genotype was significantly associated with liver weight in chicken breeds. The mRNA expression analysis in vivo and in vitro culture studies suggested that the THRSPα gene is more responsive to glucose than triiodothyronine. In conclusion, the 3 variations of the chicken THRSPα gene were associated with both growth and fat traits in this study. Such effects of the THRSPα gene were further supported from the data of observations in association analysis of the gene with phenotypic records and plasma lipid profiles, in the THRSPα gene expression in chicken development, and in vivo and in vitro cell culture observation of liver and abdominal fat tissues.
Thyroid hormone responsive spot 14 alpha (THRSP) has been used to investigate the regulation of de novo lipogenesis because the variation of THRSP mRNA content in the tissue affects directly the ...ability of that tissue to synthetize lipids. Also, this gene responds to thyroid hormone stimulation and high level of carbohydrate feeding or insulin-injection. This study was carried out to investigate variations within THRSP and their effects on body and carcass weights in Korean native chicken (KNC).
A total of 585 chickens which represent the five lines of KNC (Black, Gray-Brown, Red-Brown, White, and Yellow-Brown) were reared and body weight data were recorded every two weeks from hatch until 20 weeks of age. PCR-RFLP, DNA chips for Agilent 2100 Bioanalyzer, and Fluidigm Genotyping Technology, were applied to genotype selected markers. A linear mixed-effect model was used to access association between these SNP markers and growth-related traits.
A total of 30 polymorphisms were investigated in THRSP. Of these, nine SNPs for loci were selected to perform association analyses. Significant associations were detected between g.-49G>T SNP with BW20, g.451T>C SNP with GR10-12 trait, and g.1432A>C SNP with GR14-16 trait and BW18. Moreover, diplotype of the THRSP gene significantly affected BW12 and GR10-12 traits. Diplotype of ht1/ht2 was favorable for BW12 and GR10-12 traits.
These results suggest that THRSP can be regarded as a candidate gene for growth traits in Korean native chicken.
Spot 14 (S14) is a protein involved in fatty acid synthesis and was shown to be induced by thyroid hormone in rat liver. However, the presence of S14 in human serum and its relations with thyroid ...function status have not been investigated.The objectives of this study were to compare serum S14 concentrations in patients with hyperthyroidism or euthyroidism and to evaluate the associations between serum S14 and free thyroxine (fT4) or thyroid-stimulating hormone (TSH) levels.We set up an immunoassay for human serum S14 concentrations and compared its levels between hyperthyroid and euthyroid subjects. Twenty-six hyperthyroid patients and 29 euthyroid individuals were recruited. Data of all patients were pooled for the analysis of the associations between the levels of S14 and fT4, TSH, or quartile of TSH.The hyperthyroid patients had significantly higher serum S14 levels than the euthyroid subjects (median Q1, Q3: 975 669, 1612 ng/mL vs 436 347, 638 ng/mL, P < 0.001). In univariate linear regression, the log-transformed S14 level (logS14) was positively associated with fT4 but negatively associated with creatinine (Cre), total cholesterol (T-C), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and TSH. The positive associations between logS14 and fT4 and the negative associations between logS14 and Cre, TG, T-C, or TSH remained significant after adjustment with sex and age. These associations were prominent in females but not in males. The logS14 levels were negatively associated with the TSH levels grouped by quartile (ß = -0.3020, P < 0.001). The association between logS14 and TSH quartile persisted after adjustment with sex and age (ß = -0.2828, P = 0.001). In stepwise multivariate regression analysis, only TSH grouped by quartile remained significantly associated with logS14 level.We developed an ELISA to measure serum S14 levels in human. Female patients with hyperthyroidism had higher serum S14 levels than the female subjects with euthyroidism. The serum logS14 concentrations were negatively associated with TSH levels. Changes of serum S14 level in the whole thyroid function spectrum deserve further investigation.
We created a
Thrsp (
Spot 14 or
S14) null mouse (Thrsp
tm1cnm
) to study the role of
Thrsp in
de novo lipid synthesis. The
Thrsp null mouse exhibits marked deficiencies in
de novo lipogenesis in the ...lactating mammary gland. We now report the
Thrsp gene deletion affects body weight and glucose tolerance associated with increased insulin sensitivity. By post-natal day 150 the rate of first generation C57BL/6J backcross
Thrsp null mouse weight gain slowed compared to wild type animals. This was due to changes in body fat mass. We studied mice backcrossed for 5 and 11 generations. The weight difference between the null and wild type adult mice diminished with progressive backcross generations. In conclusion the
Thrsp gene is involved in the regulation of diet-induced obesity and deletion of
Thrsp leads to an improvement in age associated glucose tolerance.
In mammals, thyroid hormone responsive Spot 14 (THRSP) is a small acidic protein that is predominately expressed in lipogenic tissue (i.e., liver, abdominal fat and the mammary gland). This gene has ...been postulated to play a role in lipogenesis, since it responds to thyroid hormone stimulation, high glucose levels and it is localized to a chromosomal region implicated in obesity. In this paper, we report the identification and characterization of duplicated polymorphic paralogs of Spot 14 in the chicken,
THRSPα and
THRSPβ. Despite low similarity in amino acid (aa) sequence between chickens and mammals, other properties of Spot 14 (i.e., pI, subcellular localization, transcriptional control and functional domains) appear to be highly conserved. Furthermore, a synteny group of
THRSP and its flanking genes NADH dehydrogenase (
NDUFC2) and glucosyltransferase (
ALG8) appears to be conserved among chickens, humans, mice and rats. Polymorphic alleles, involving a variable number of tandem repeats (VNTR), were discovered in the putative protein coding region of the duplicated chicken
THRSPα (9 bp) and
THRSPβ (6 or 12 bp) genes. Our study shows that the
THRSPα locus is associated with abdominal fat traits in a broiler×Leghorn resource population.
Liposarcomas (LS) are mesenchymal tumors that can recur after surgical resection and often do not respond to presently available medical therapies. This study demonstrates the dependence of LS on de ...novo long-chain fatty acid synthesis for growth. Lipogenesis can be impaired by inhibiting the activities of lipogenic enzymes, including acetyl CoA-carboxylase (ACC) and fatty acid synthase (FASN), or by suppressing the expression of key genes involved in the pathway and its regulation. The FASN inhibitors cerulenin and orlistat reduced the growth of two LS cell lines (LiSa2, SW872), as did inhibition of ACC with soraphen A. CDDO-Me, a synthetic triterpenoid, suppressed expression of Spot 14 and FASN genes and likewise inhibited LS cell growth. Importantly, the anti-proliferative effect of each agent was prevented by the co-administration of palmitate, the major product of cellular long-chain fatty acid synthesis. In stark contrast to LS cells, these compounds had no effect on the growth of fibroblasts. Four biochemically distinct agents that target critical points in the fatty acid synthetic pathway exert anti-proliferative effects on LS cells, and rescue of cell growth by palmitic acid suggests that reduced tumor cell lipogenesis mediates the growth inhibition. These findings warrant further studies aimed at the clinical exploitation of the dependence of LS cell growth on fatty acids.
Context: Very limited information is available regarding the function of human thyroid hormone responsive Spot 14 (human S14, hS14) in adipogenesis and human adiposity. Objective: To evaluate hS14 ...levels during differentiation of human pre-adipocytes, in human fat depots and isolated fat cells. Design: This was a cross-sectional study. Subjects: A total of 161 omental (OM) and 87 subcutaneous (SC) adipose tissue samples obtained during elective surgical procedures from a population who varied widely in terms of obesity.Measurements: hS14 gene expression and protein levels during adipogenesis were assessed by RT–PCR, western blot, and using an automated confocal imaging approach. Results: hS14 gene expression levels were decreased in OM adipose tissue from overweight (−42.0%) and obese subjects (−56.5%) compared with lean subjects (P<0.05 and P<0.0001, respectively). hS14 mRNA (but not hS14-related) was inversely associated with obesity measures such as body mass index (P=0.001), percent fat mass (P=0.001), waist-to-hip ratio (P=0.020), and systolic blood pressure (P=0.031). hS14 gene expression and protein levels were up-regulated at the early stages of differentiation of human pre-adipocytes as well as for 3T3-L1 cells. That observation was most prominent in those individual cells exhibiting the more marked differentiation features. hS14 gene expression levels increased by approximately 45 000-fold in mature adipocytes. Increased hS14 levels were also found in stromal-vascular cells/pre-adipocytes (3.8-fold, P<0.05) and in adipose tissue samples (1.9-fold, P<0.0001) from SC compared with OM fat depots. Conclusions: These results suggest that hS14 is involved in human adipogenesis, but inversely related to obesity and OM fat accumulation.
Spot 14 (S14) is a small acidic protein with no sequence similarity to other mammalian gene products. Its biochemical function is elusive. Recent studies have shown that, in some cancers, human S14 ...(hS14) localizes to the nucleus and is amplified, suggesting that it plays a role in the regulation of lipogenic enzymes during tumorigenesis. In this study, we purified untagged hS14 protein and then demonstrated, using various biochemical methods, including analytic ultracentrifugation, that hS14 might form a homodimer. We also found several lines of evidence to suggest physical and functional interactions between hS14 and the thyroid hormone receptor (TR). The ubiquitous expression of hS14 in various cell lines and its cell-type-dependent functions demonstrated in this study suggest that it acts as a positive or negative cofactor of the TR to regulate malic enzyme gene expression. These findings provide a molecular rationale for the role of hS14 in TR-dependent transcriptional activation of the expression of specific genes.
Most breast cancers exhibit brisk lipogenesis, and require it for growth. S14 is a lipogenesis-related nuclear protein that is overexpressed in most breast cancers. Sterol response element-binding ...protein-1c (SREBP-1c) is required for induction of lipogenesis-related genes, including S14 and fatty acid synthase (FAS), in hepatocytes, and correlation of SREBP-1c and FAS expression suggested that SREBP-1c drives lipogenesis in tumors as well. We directly tested the hypothesis that SREBP-1c drives S14 expression and mediates lipogenic effects of progestin in T47D breast cancer cells. Dominant-negative SREBP-1c inhibited induction of S14 and FAS mRNAs by progestin, while active SREBP-1c induced without hormone and superinduced in its presence. Changes in S14 mRNA were reflected in protein levels. A lag time and lack of progestin response elements indicated that S14 and FAS gene activation by progestin is indirect. Knockdown of S14 reduced, whereas overexpression stimulated, T47D cell growth, while nonlipogenic MCF10a mammary epithelial cells were not growth-inhibited. These data directly demonstrate that SREBP-1c drives S14 gene expression in breast cancer cells, and progestin magnifies that effect via an indirect mechanism. This supports the prediction, based on S14 gene amplification and overexpression in breast tumors, that S14 augments breast cancer cell growth and survival.
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