Differential expression and secretion of α1-acid glycoprotein in bovine milk

2007 ◽  
Vol 74 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Fabrizio Ceciliani ◽  
Vanessa Pocacqua ◽  
Cristina Lecchi ◽  
Riccardo Fortin ◽  
Raffaella Rebucci ◽  
...  

α1-Acid glycoprotein (AGP) is a lipocalin that is produced mainly by the liver and secreted into plasma in response to infections and injuries. In this study, we evaluated AGP isoforms that can be detected in bovine milk. We found that milk-AGP content is made up of at least two isoform groups, a low MW group (44 kDa) that is produced in the mammary gland (MG-AGP), and a higher MW group (55–70 kDa), that is produced by somatic cells (SC-AGP). Identical SC-AGP isoforms can be found both in milk and blood PMN cells. Analysis of the mammary tissue cDNA showed that the sequence of the MG-AGP isoform is identical to that of plasma AGP. Each group contains several proteins with different MWs and different isoelectric points, as shown by 2D-electrophoresis. The glycosylation patterns of these isoforms were analysed by means of specific lectin binding, to evaluate the degree of sialylation, fucosylation and branching. The MG-AGP glycan pattern was identical to plasma AGP produced by the liver. Several differences were detected, however, between plasma and SC-AGP isoforms, the most evident being the strong degree of fucosylation and the elevated number of di-antennary glycans in SC-AGP. Immunohistochemistry showed that AGP is found in all tissues that make up the mammary gland, but that it is most likely produced for the main part by the alveoli.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masahiko Terajima ◽  
Yuki Taga ◽  
Becky K. Brisson ◽  
Amy C. Durham ◽  
Kotaro Sato ◽  
...  

AbstractIn spite of major advances over the past several decades in diagnosis and treatment, breast cancer remains a global cause of morbidity and premature death for both human and veterinary patients. Due to multiple shared clinicopathological features, dogs provide an excellent model of human breast cancer, thus, a comparative oncology approach may advance our understanding of breast cancer biology and improve patient outcomes. Despite an increasing awareness of the critical role of fibrillar collagens in breast cancer biology, tumor-permissive collagen features are still ill-defined. Here, we characterize the molecular and morphological phenotypes of type I collagen in canine mammary gland tumors. Canine mammary carcinoma samples contained longer collagen fibers as well as a greater population of wider fibers compared to non-neoplastic and adenoma samples. Furthermore, the total number of collagen cross-links enriched in the stable hydroxylysine-aldehyde derived cross-links was significantly increased in neoplastic mammary gland samples compared to non-neoplastic mammary gland tissue. The mass spectrometric analyses of type I collagen revealed that in malignant mammary tumor samples, lysine residues, in particular those in the telopeptides, were markedly over-hydroxylated in comparison to non-neoplastic mammary tissue. The extent of glycosylation of hydroxylysine residues was comparable among the groups. Consistent with these data, expression levels of genes encoding lysyl hydroxylase 2 (LH2) and its molecular chaperone FK506-binding protein 65 were both significantly increased in neoplastic samples. These alterations likely lead to an increase in the LH2-mediated stable collagen cross-links in mammary carcinoma that may promote tumor cell metastasis in these patients.


2015 ◽  
Vol 35 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Vânia F. Lemos ◽  
Eduardo L.S. Guaraná ◽  
José A.B. Afonso ◽  
José J. Fagliari ◽  
Paulo C. Silva ◽  
...  

The study aimed to identify potential biomarkers of mammary gland infection in Santa Inês sheep. Commercial flocks of sheep provided the same hygiene, sanitary, and nutritional management under semi-intensive production systems were monitored during the lactation stage-and assessed 15, 30, 60, and 90 days after delivery (through the end of lactation and weaning). The California Mastitis Test (CMT) was performed on the mammary glands. Milk was collected for bacterial examination and protein analysis. Bacterial culture and biochemical characterization of the samples were performed. Forty-two milk samples from healthy glands (negative CMT and bacterial testing) and 43 milk samples from infected glands (positive CMT and bacterial testing) taken at the predefined time points were assessed. A rennin solution was used to obtain the whey. The proteins analysis was performed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), which allowed for the quantification of nine whey proteins produced in healthy glands: serum albumin, lactoferrin, IgA, IgG heavy-chain (IgG HC), IgG light-chain (IgG LC), total IgG (IgG HC + IgG LC), α-lactalbumin, β-lactoglobulin, protein with MW 15.000 Da, protein with MW 29.000 Da and eleven whey proteins secreted by infected glands, including haptoglobin and α-1-acid glycoprotein. A comparison of whey proteins between healthy and infected glands showed increases (P<0.05) in the secreted and total contents of all proteins, except for IgG LC and α-lactoalbumin. The most significant changes were observed in α-1-acid glycoprotein, lactoferrin and haptoglobin, which showed three-, five-, and seven-fold increases in secretion, respectively. This study showed that haptoglobin, α-1-acid glycoprotein, lactoferrin, albumin, and the IgA and IgG immunoglobulins may serve as potential biomarkers for mammary gland infection in sheep.


2005 ◽  
Vol 45 (8) ◽  
pp. 757 ◽  
Author(s):  
C. Gray ◽  
Y. Strandberg ◽  
L. Donaldson ◽  
R. L. Tellam

Innate immunity plays a vital role in the protection of the bovine mammary gland against mastitis. Until recently, the migration of effector cells such as neutrophils and monocytes into the mammary gland was thought to provide the only defence against invading pathogens. However, mammary epithelial cells may also play an important role in the immune response, contributing to the innate defence of the mammary tissue through secretion of antimicrobial peptides and attraction of circulating immune effector cells. This paper reviews the innate immune pathways in mammary epithelial cells and examines their role in the initiation of an innate immune response to Gram-positive and Gram-negative bacteria.


2004 ◽  
Vol 71 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Paul A Sheehy ◽  
James J Della-Vedova ◽  
Kevin R Nicholas ◽  
Peter C Wynn

A method for the collection of mammary biopsies developed previously was refined and used to study the endocrine regulation of bovine milk protein gene expression. Our surgical biopsy method used real-time ultrasound imaging and epidural analgesia to enable recovery of a sufficient quantity of mammary tissue from late-pregnant dairy cows for explant culture in vitro. The time of biopsy was critical for prolactin-dependent induction of milk protein gene expression in mammary explants, as only mammary tissue from cows nearing 30 d prepartum was hormone-responsive. This suggests that during the later stages of pregnancy a change in the responsiveness of milk protein gene expression to endocrine stimuli occurred in preparation for lactation. This may relate to the diminution of a putative population of undifferentiated cells that were still responsive to prolactin. Alternatively, the metabolic activity of the tissue had increased to the level whereby the response of the tissue was no longer assessable using this model in vitro.


1982 ◽  
Vol 203 (1) ◽  
pp. 45-50 ◽  
Author(s):  
P M Ahmad ◽  
D S Feltman ◽  
F Ahmad

A simple procedure was devised which allows purification of rat lactating-mammary-gland fatty acid synthase to a high degree of purity, with recoveries of activity exceeding 50%. Over 50 mg of enzyme was isolated from 60 g of mammary tissue. The specific activity of the purified enzyme was about 2.5 mumol of NADPH oxidized/min per mg of protein at 37 degrees. The enzyme appeared homogeneous by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and by immunodiffusion analysis. Each mol (Mr 480 000) of the enzyme bound 3 mol of acetyl and 3-4 mol of malonyl groups when the binding experiments were performed at 0 degrees for 30 s. The presence of NADPH did not influence the binding stoicheiometry for these acyl-CoA derivatives. Approx. 2 mol of taurine was found per mol of the performic acid-oxidized enzyme, suggesting that there were 2 mol of 4′-phosphopantetheine in the native enzyme. Rat mammary-gland fatty acid synthase required free CoA for activity.


2007 ◽  
Vol 87 (2) ◽  
pp. 281-284 ◽  
Author(s):  
R. N. Kirkwood ◽  
J. Pérez Laspiur ◽  
N. K. Ames ◽  
J. B. Moore ◽  
A. Cegielski ◽  
...  

To determine morphological and molecular characteristics of porcine mammary tissue in vivo, mammary tissue was collected from 18 sows at 3 to 6 d of lactation and 17 to 19 d of lactation using a biopsy technique. The success of the technique was determined by monitoring lactation performance, as evidenced by sow rectal temperature, voluntary feed intake, milk somatic cell count, and piglet average daily gain. Up to 1.7 g of mammary tissue was collected at each biopsy without decreasing sow feed intake or piglet growth. Key words: Biopsy, mammary gland, lactation, sow


Development ◽  
2000 ◽  
Vol 127 (14) ◽  
pp. 3107-3118 ◽  
Author(s):  
A.V. Nguyen ◽  
J.W. Pollard

Involution of the mammary gland following weaning is divided into two distinct phases. Initially, milk stasis results in the induction of local factors that cause apoptosis in the alveolar epithelium. Secondly after a prolonged absence of suckling, the consequent decline in circulating lactogenic hormone concentrations initiates remodeling of the mammary gland to the virgin-like state. We have shown that immediately following weaning TGFbeta3 mRNA and protein is rapidly induced in the mammary epithelium and that this precedes the onset of apoptosis. Unilateral inhibition of suckling and hormonal reconstitution experiments showed that TGFbeta3 induction is regulated by milk stasis and not by the circulating hormonal concentration. Directed expression of TGFbeta3 in the alveolar epithelium of lactating mice using a beta-lactoglobulin promoter mobilized SMAD4 translocation to the nucleus and caused apoptosis of these cells, but not tissue remodeling. Transplantation of neonatal mammary tissue derived from TGFbeta3 null mutant mice into syngenic hosts resulted in a significant inhibition of cell death compared to wild-type mice upon milk stasis. These results provide direct evidence that TGFbeta3 is a local mammary factor induced by milk stasis that causes apoptosis in the mammary gland epithelium during involution.


2019 ◽  
Author(s):  
◽  
Ricardo Oliveira Rodrigues

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Disruptive effects of climate change, such as increasing environmental temperature, have direct impacts on economic viability and efficiency of food production. In lactating dairy cows, heat stress reduces milk production and alters function of mammary secretory cells, at least partly by disturbing local protein metabolism. We hypothesized that hyperthermia would not only reduce mammary blood flow but would also reduce mammary extraction of nutrients from blood. In addition, we hypothesized that transcriptional profiling of mammary tissue would reveal disruption of cellular homeostasis. Our objective was to determine the effects of hyperthermia on mammary function. More specifically, we aimed to profile mammary blood flow and the changes in mammary transcriptome of heat-stressed lactating dairy cows. We investigated the effects of early and prolonged exposure of lactating dairy cows to hyperthermia by exposing cows to programmed constantly elevated temperature and humidity to induce and maintain body temperature approximately 1[degree]C above normal. Experiments were conducted to evaluate the production responses of hyperthermic lactating dairy cows, to characterize total and nutritive mammary blood flow, and to elucidate the regulation of mammary function during early and prolonged exposure to hyperthermia. Results from these studies established that 1) hyperthermia reduces total and nutritive mammary blood flow, limiting nutrient disappearance across the mammary gland; 2) hyperthermia does not induce shunting of blood away from the gland; 3) hyperthermia affects mammary tissue transcriptome, mainly altering processes associated with ECM and cell adhesion; 4) the effects of exposure to prolonged heat stress on mammary gene expression are distinct from the effects of feed restriction, in lactating dairy cows; and 5) mammary function is reestablished within 8 days after cessation of heat stress.


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