scholarly journals STAT5 binding contributes to lactational stimulation of promoter III expressing the bovine acetyl-CoA carboxylase alpha-encoding gene in the mammary gland

2002 ◽  
Vol 29 (1) ◽  
pp. 73-88 ◽  
Author(s):  
J Mao ◽  
AJ Molenaar ◽  
TT Wheeler ◽  
HM Seyfert
Keyword(s):  
Mammary Gland ◽  
De Novo ◽  
Point Mutations ◽  
Luciferase Reporter ◽  
Acetyl Coa Carboxylase ◽  
Luciferase Reporter Gene ◽  
Acetyl Coa ◽  
Rnase Protection ◽  
Lactating Mammary Gland ◽  
Encoding Gene

Activity of acetyl-CoA carboxylase (ACC)-alpha is rate limiting for de novo synthesis of fatty acids. The encoding gene is expressed by three different promoters. We characterized promoter III (PIII) from cow, previously only known from sheep. Quantitation of transcripts by RNAse protection assays and real time PCR revealed that PIII is primarily expressed and strongly induced ( approximately 28-fold) in the lactating mammary gland. PIII transcripts are expressed in mammary epithelial cells (MEC) as shown by in situ hybridization. A 2999 bp segment of the PIII promoter conferred prolactin and dexamethasone inducibility to a luciferase reporter gene in stably transfected mouse MEC cells. Lactogenic induction was abolished if a unique signal transducer and activator of transcription (STAT)-binding site at position -797 was inactivated by two point mutations. An oligonucleotide probe harboring this STAT-site specifically bound nuclear proteins from the lactating mammary gland. Binding was abolished by those two point mutations and super-shift analyses showed that STAT5A factors are present in this complex. Hence, prolactin, acting through STAT5, contributes to the activation of ACC expression in the milk producing cells of the lactating mammary gland. We discuss that STAT5 might be important in determining the milk composition by coordinating fatty acid and protein synthesis during lactation.

scholarly journals Induction of transcripts derived from promoter III of the acetyl-CoA carboxylase-α gene in mammary gland is associated with recruitment of SREBP-1 to a region of the proximal promoter defined by a DNase I hypersensitive site

2003 ◽  
Vol 375 (2) ◽  
pp. 489-501 ◽  
Author(s):  
Michael C. BARBER ◽  
Amanda J. VALLANCE ◽  
Helen T. KENNEDY ◽  
Maureen T. TRAVERS
Keyword(s):  
Mammary Gland ◽  
De Novo ◽  
Dnase I ◽  
Proximal Region ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Proximal Site

ACC-α (acetyl-CoA carboxylase-α), a key regulator of fatty-acid metabolism, is encoded by mRNAs transcribed from three promoters, PI, PII and PIII, in the ovine genome. Enhanced expression of transcripts encoded by PIII in mammary gland during lactation is associated with alterations in chromatin structure that result in the detection of two DNase I hypersensitive sites, upstream of the start site. The most proximal site, located between −190 and −10, is characterized by the presence of an inverted-CCAAT box, C2 at −167, and E-boxes, E1 and E2, at −151 and −46. Deletion of these motifs, which bind nuclear factor-Y and upstream stimulatory factors respectively in gel-shift assays, attenuates the activity of luciferase reporter constructs in transfected cells. Chromatin immunoprecipitation demonstrated that these transcription factors were associated with PIII in vivo in both lactating and non-lactating mammary tissues. The basic helix–loop–helix-leucine zipper transcription factor, SREBP-1 (sterol-regulated-element-binding protein-1), transactivated PIII reporter constructs in transfected HC11 mammary cells, and this was dependent on the presence of E1, but not on C2 or E2. SREBP-1 was only associated with PIII in chromatin from lactating animals, which was coincident with a 4-fold increase in the precursor (125 kDa) form of SREBP-1 in microsomes and the appearance of the mature form (68 kDa) in the nucleus. SREBP-1 motifs are also present in the proximal region of PII, which is also induced in lactation. This indicates that SREBP-1 is a major developmental regulator of the programme of lipid synthesis de novo in the lactating mammary gland.

Promoter I of the ovine acetyl-CoA carboxylase-α gene: an E-box motif at −114 in the proximal promoter binds upstream stimulatory factor (USF)-1 and USF-2 and acts as an insulin-response sequence in differentiating adipocytes

2001 ◽  
Vol 359 (2) ◽  
pp. 273-284 ◽  
Author(s):  
Maureen T. TRAVERS ◽  
Amanda J. VALLANCE ◽  
Helen T. GOURLAY ◽  
Clare A. GILL ◽  
Izabella KLEIN ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Binding Protein ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Acetyl Coa Carboxylase ◽  
Upstream Stimulatory Factor ◽  
Acetyl Coa ◽  
Rnase Protection ◽  
E Box ◽  
Stimulatory Factor

Acetyl-CoA carboxylase-α (ACC-α) plays a central role in co-ordinating de novo fatty acid synthesis in animal tissues. We have characterized the regulatory region of the ovine ACC-α gene. Three promoters, PI, PII and PIII, are dispersed throughout 50kb of genomic DNA. Expression from PI is limited to adipose tissue and liver. Sequence comparison of the proximal promoters of ovine and mouse PIs demonstrates high nucleotide identity and that they are characterized by a TATA box at −29, C/EBP (CCAAT enhancer-binding protein)-binding motifs and multiple E-box motifs. A 4.3kb ovine PI-luciferase reporter construct is insulin-responsive when transfected into differentiated ovine adipocytes, whereas when this construct is transfected into ovine preadipocytes and HepG2 cells the construct is inactive and is not inducible by insulin. By contrast, transfection of a construct corresponding to 132bp of the proximal promoter linked to a luciferase reporter is active and inducible by insulin in all three cell systems. Insulin signalling to the −132bp construct in differentiated ovine adipocytes involves, in part, an E-box motif at −114. Upstream stimulatory factor (USF)-1 and USF-2, but not sterol regulatory element-binding protein 1 (SREBP-1), are major components of protein complexes that bind this E-box motif. Activation of the 4.3kb PI construct in differentiated ovine adipocytes is associated with endogenous expression of PI transcripts throughout differentiation; PI transcripts are not detectable by RNase-protection assay in ovine preadipocytes, HepG2 cells or 3T3-F442A adipocytes. These data indicate the presence of repressor motifs in PI that are required to be de-repressed during adipocyte differentiation to allow induction of the promoter by insulin.

Malonyl coenzyme A decarboxylase deficiency with a novel mutation

2021 ◽  
pp. 1-3
Author(s):  
Cigdem S. Kasapkara ◽  
Burcu Civelek Ürey ◽  
Ahmet C. Ceylan ◽  
Özlem Ünal Uzun ◽  
Ibrahim İ. Çetin
Keyword(s):  
De Novo ◽  
Novel Mutation ◽  
Point Mutations ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Metabolic Intermediate ◽  
Malonyl Coa ◽  
Novel Variant ◽  
Malonic Aciduria

Abstract Malonyl-CoA, a product of acetyl-CoA carboxylase is a metabolic intermediate in lipogenic tissues that include liver and adipose tissue, where it is involved in the de novo fatty acid synthesis and elongation. Malonyl-CoA decarboxylase (MLYCD, E.C.4.1.1.9), a 55-kDa enzyme catalyses the conversion of malonyl-CoA to acetyl-CoA and carbon dioxide, thus providing a route for disposal of malonyl-CoA from mitochondria and peroxisomes, whereas in the cytosol, the malonyl-CoA pool is regulated by the balance of MLYCD and acetyl-CoA carboxylase activities. So far, 34 cases with different MLYCD gene defects comprising point mutations, stop codons, and frameshift mutations have been reported in the literature. Here, we describe the follow-up of a patient affected by malonic aciduria upon neonatal onset. Molecular analysis showed novel homozygous mutations in the MLYCD gene. Our findings expand the number of reported cases and add a novel variant to the repertoire of MLYCD mutations.

scholarly journals Growth-hormone-prolactin interactions in the regulation of mammary and adipose-tissue acetyl-CoA carboxylase activity and gene expression in lactating rats

1992 ◽  
Vol 285 (2) ◽  
pp. 469-475 ◽  
Author(s):  
M C Barber ◽  
M T Travers ◽  
E Finley ◽  
D J Flint ◽  
R G Vernon
Keyword(s):  
Adipose Tissue ◽  
Mammary Gland ◽  
Serum Prolactin ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Total Enzyme Activity ◽  
Mrna Concentration ◽  
Total Enzyme ◽  
Activation Status

The factors and mechanisms responsible for the reciprocal changes in lipogenesis in rat mammary gland and adipose tissue during the lactation cycle have been investigated. Lactation decreased the activation status and mRNA concentration of acetyl-CoA carboxylase in adipose tissue. Litter removal decreased the mRNA concentration of acetyl-CoA carboxylase in the mammary gland and increased the enzyme's mRNA concentration and activation status in adipose tissue. Lowering serum prolactin concentration in lactating rats decreased the amount of mammary acetyl-CoA carboxylase mRNA and increased that of adipose tissue, and increased the activation status of the enzyme in adipose tissue. Decreasing serum growth hormone (GH) alone had little effect on acetyl-CoA carboxylase in lactating rats, although it did lower pup growth rate and serum concentration of insulin-like growth factor-I. Lowering serum GH concentration exacerbated the effects of decreasing serum prolactin on mammary-gland (but not adipose-tissue) acetyl-CoA carboxylase mRNA and further increased the rise in activation status of the adipose-tissue enzyme induced by decreasing serum prolactin. Changes in acetyl-CoA carboxylase mRNA in both mammary and adipose tissue were paralleled by changes in total enzyme activity except after litter removal, when there was a disproportionately large decrease in total enzyme activity of the mammary gland. Thus prolactin has a major and GH a minor role in the regulation of acetyl-CoA carboxylase activity during lactation. Changes in mammary activity in response to prolactin and GH are primarily due to alterations in gene transcription, whereas adaptation in adipose tissue involves both changes in gene transcription and activation status.

scholarly journals Regulation of acetyl-CoA carboxylase in rat mammary gland. Effects of starvation and of insulin and prolactin deficiency on the fraction of the enzyme in the active form in vivo

1982 ◽  
Vol 204 (1) ◽  
pp. 273-280 ◽  
Author(s):  
Elizabeth M. McNeillie ◽  
Victor A. Zammit
Keyword(s):  
Mammary Gland ◽  
Enzyme Activities ◽  
Enzyme Concentration ◽  
Acetyl Coa Carboxylase ◽  
Initial Activity ◽  
Acetyl Coa ◽  
Activity Ratios ◽  
Rat Mammary Gland ◽  
Rate Limiting

The ‘initial’ (I), endogenous phosphatase-activated (A) and citrate-activated (C) activities of acetyl-CoA carboxylase were measured in mammary-gland extracts of pregnant and lactating rats. There was a 10-fold increase in the A and C enzyme activities in the transition from early to peak lactation [cf. data of Mackall & Lane (1977) Biochem. J.162, 635–642], but there was no significant increase in the ratio of the initial activity to the A and C activities of the enzyme. Starvation (24h) or short-term (3h) streptozotocin-induced diabetes both resulted in a 40% decrease in I/A and I/C activity ratios. In starvation this was accompanied by a decrease in the absolute values of the A and C activities such that the initial activity in mammary glands of starved animals was 45% that in glands from fed animals. Insulin treatment of starved or diabetic animals 60min before killing increased the I activity without affecting the A or C enzyme activities. Removal of the pups for 24h from animals in peak lactation (weaning) resulted in a marked but similar decrease in all three activities such that, although the initial activity was only 10% of that in suckled animals, the I/A and I/C activity ratios remained high and unaltered. Inhibition of prolactin secretion by injection of 2-bromo-α-ergocryptine gave qualitatively similar results to those during weaning. Simultaneous administration of ovine prolactin completely prevented the effects of bromoergocryptine. It is suggested that the initial activity of acetyl-CoA carboxylase in rat mammary gland is regulated by at least two parallel mechanisms: (i) an acute regulation of the proportion of the enzyme in the active state and (ii) a longer-term modulation of enzyme concentration in the gland. Insulin appeared to mediate its acute effects through mechanism (i), whereas prolactin had longer-term effects on enzyme concentration in the gland. A comparison of initial enzyme activities (I) obtained in the present study with rates of lipogenesis measured in vivo [Agius & Williamson (1980) Biochem. J.192, 361–364; Munday & Williamson (1981) Biochem. J.196, 831–837] gave good agreement between the two sets of data for all conditions studied except for 24h-starved and streptozotocin-diabetic animals. It is suggested that acetyl-CoA carboxylase activity is rate-limiting for lipogenesis in the mammary gland in normal, fed, suckled or weaned animals but that in starved and short-term diabetic animals changes in the activity of the enzyme by covalent modification alone may not be sufficient to maintain the enzyme in its rate-limiting role.

scholarly journals LncRNA-42060 Regulates Tamoxifen Sensitivity and Tumor Development via Regulating the miR-204-5p/SOX4 Axis in Canine Mammary Gland Tumor Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Enshuang Xu ◽  
Mengxin Hu ◽  
Reidong Ge ◽  
Danning Tong ◽  
Yuying Fan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mammary Gland ◽  
Tumor Cells ◽  
Luciferase Reporter ◽  
Drug Resistant ◽  
Mammary Gland Tumor ◽  
Luciferase Reporter Gene ◽  
Gland Tumor ◽  
Canine Mammary Gland ◽  
Resistant Cells

Tamoxifen is the drug of choice for endocrine therapy of breast cancer. Its clinical use is limited by the development of drug resistance. There is increasing evidence that long non-coding RNAs (lncRNAs) are associated with tumor drug resistance. Therefore, we established two TAM-resistant cell lines, CHMpTAM and CHMmTAM. The different expression levels of lncRNA and miRNA in CHMmTAM and CHMm were screened by RNA sequencing, and the lncRNA-miRNA interactions were analyzed. LncRNA ENSCAFG42060 (lnc-42060) was found to be significantly upregulated in drug-resistant cells and tumor tissues. Further functional validation revealed that the knockdown of lnc-42060 inhibited proliferation, migration, clone formation, restoration of TAM sensitivity, and reduction of stem cell formation in drug-resistant cells, whereas overexpression of lnc-4206 showed opposite results. Bioinformatics and dual-luciferase reporter gene assays confirmed that lnc-42060 could act as a sponge for miR-204-5p, further regulating SOX4 expression activity and thus influencing tumor cell progression. In conclusion, we screened lncRNAs and miRNAs associated with TAM resistance in canine mammary gland tumor cells for the first time. lnc-42060 served as a novel marker that may be used as an important biomarker for future diagnosis and treatment.

scholarly journals Acetyl-CoA Carboxylase 2−/− Mutant Mice are Protected against Fatty Liver under High-fat, High-carbohydrate Dietary and de Novo Lipogenic Conditions

2012 ◽  
Vol 287 (15) ◽  
pp. 12578-12588 ◽  
Author(s):  
Lutfi Abu-Elheiga ◽  
Hongmei Wu ◽  
Ziwei Gu ◽  
Rubin Bressler ◽  
Salih J. Wakil
Keyword(s):  
Fatty Liver ◽  
De Novo ◽  
Mutant Mice ◽  
Acetyl Coa Carboxylase ◽  
Wild Type ◽  
High Fat ◽  
Acetyl Coa ◽  
High Carbohydrate ◽  
Ppar Γ ◽  
Hepatic Fat

Hepatic fat accumulation resulting from increased de novo fatty acid synthesis leads to hepatic steatosis and hepatic insulin resistance. We have shown previously that acetyl-CoA carboxylase 2 (Acc2−/−) mutant mice, when fed a high-fat (HF) or high-fat, high-carbohydrate (HFHC) diet, are protected against diet-induced obesity and maintained whole body and hepatic insulin sensitivity. To determine the effect of an ACC2 deletion on hepatic fat metabolism, we studied the regulation of the enzymes involved in the lipogenic pathway under Western HFHC dietary and de novo lipogenic conditions. After completing the HFHC regimen, Acc2−/− mutant mice were found to have lower body weight, smaller epididymal fat pads, lower blood levels of nonesterified fatty acids and triglycerides, and higher hepatic cholesterol than wild-type mice. Significant up-regulation of lipogenic enzymes and an elevation in hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) protein were found in Acc2−/− mutant mice under de novo lipogenic conditions. The increase in lipogenic enzyme levels was accompanied by up-regulation of the transcription factors, sterol regulatory element-binding proteins 1 and 2, and carbohydrate response element-binding protein. In contrast, hepatic levels of the PPAR-γ and PPAR-α proteins were significantly lower in the Acc2−/− mutant mice fed an HFHC diet. When compared with wild-type mice fed the same diet, Acc2−/− mutant mice exhibited a similar level of AKT but with a significant increase in pAKT. Hence, deleting ACC2 ameliorates the metabolic syndrome and protects against fatty liver despite increased de novo lipogenesis and dietary conditions known to induce obesity and diabetes.

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