scholarly journals Weaning-induced expression of a milk-fat globule protein, MFG-E8, in mouse mammary glands, as demonstrated by the analyses of its mRNA, protein and phosphatidylserine-binding activity

2006 ◽  
Vol 395 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Hajime Nakatani ◽  
Naohito Aoki ◽  
Yoshimi Nakagawa ◽  
Shinji Jin-No ◽  
Koji Aoyama ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Milk Fat ◽  
Mammary Glands ◽  
Binding Activity ◽  
Mammary Tissue ◽  
Double Positive ◽  
Fat Globules ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule

A milk membrane glycoprotein, MFG-E8 [milk fat globule-EGF (epidermal growth factor) factor 8], is expressed abundantly in lactating mammary glands in stage- and tissue-specific manners, and has been believed to be secreted in association with milk fat globules. In the present paper, we describe further up-regulation of MFG-E8 in involuting mammary glands, where the glands undergo a substantial increase in the rate of epithelial cell apoptosis, and a possible role of MFG-E8 in mediating recognition and engulfment of apoptotic cells through its specific binding to PS (phosphatidylserine). Immunoblotting and RNA blotting analyses revealed that both MFG-E8 protein and MFG-E8 mRNA were markedly increased in mammary tissue within 3 days of either natural or forced weaning (pup withdrawal) of lactating mice. Using immunohistochemical analysis of the mammary tissue cryosections, the MFG-E8 signal was detected around the epithelium of such involuting mammary glands, but was almost undetectable at early- and mid-lactation stages, although strong signals were obtained for milk fat globules stored in the alveolar lumen. Some signals double positive to a macrophage differentiation marker, CD68, and MFG-E8 were detected in the post-weaning mammary tissue, although such double-positive signals were much smaller in number than the MFG-E8 single-positive ones. Total MFG-E8 in milk was also increased in the post-weaning mammary glands and, furthermore, the free MFG-E8 content in the post-weaning milk, as measured by in vitro PS-binding and apoptotic HC11 cell-binding activities, was much higher than that of lactation. In addition, the post-weaning milk enhanced the binding of apoptotic HC11 cells to J774 macrophages. Sucrose density-gradient ultracentrifugation analyses revealed that such enhanced PS-binding activity of MFG-E8 was present in membrane vesicle fractions (density 1.05–1.13 g/ml), rather than milk fat globule fractions. The weaning-induced MFG-E8 might play an important role in the recognition and engulfment of apoptotic epithelial cells by the neighbouring phagocytic epithelial cells in involuting mammary glands.

scholarly journals Milk Fat Globule Membrane Proteome and Micronutrients in the Milk Lipid Fraction: Insights into Milk Bioactive Compounds

Dairy ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 202-217
Author(s):  
Michele Manoni ◽  
Donata Cattaneo ◽  
Sharon Mazzoleni ◽  
Carlotta Giromini ◽  
Antonella Baldi ◽  
...  
Keyword(s):  
Milk Fat ◽  
Lipid Fraction ◽  
Value Added ◽  
Milk Lipid ◽  
Milk Fat Globule Membrane ◽  
Fat Globules ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Value Added Products

Milk lipids are composed of milk fat globules (MFGs) surrounded by the milk fat globule membrane (MFGM). MFGM protects MFGs from coalescence and enzymatic degradation. The milk lipid fraction is a “natural solvent” for macronutrients such as phospholipids, proteins and cholesterol, and micronutrients such as minerals and vitamins. The research focused largely on the polar lipids of MFGM, given their wide bioactive properties. In this review we discussed (i) the composition of MFGM proteome and its variations among species and phases of lactation and (ii) the micronutrient content of human and cow’s milk lipid fraction. The major MFGM proteins are shared among species, but the molecular function and protein expression of MFGM proteins vary among species and phases of lactation. The main minerals in the milk lipid fraction are iron, zinc, copper and calcium, whereas the major vitamins are vitamin A, β-carotene, riboflavin and α-tocopherol. The update and the combination of this knowledge could lead to the exploitation of the MFGM proteome and the milk lipid fraction at nutritional, biological or technological levels. An example is the design of innovative and value-added products, such as MFGM-supplemented infant formulas.

scholarly journals Comparative Proteomics of Milk Fat Globule Membrane (MFGM) Proteome across Species and Lactation Stages and the Potentials of MFGM Fractions in Infant Formula Preparation

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1251 ◽  
Author(s):  
Michele Manoni ◽  
Chiara Di Lorenzo ◽  
Matteo Ottoboni ◽  
Marco Tretola ◽  
Luciano Pinotti
Keyword(s):  
Milk Fat ◽  
Human Breast Milk ◽  
Primary Role ◽  
Water Emulsion ◽  
Milk Fat Globule Membrane ◽  
Fat Globules ◽  
Lipid Fractions ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule

Milk is a lipid-in-water emulsion with a primary role in the nutrition of newborns. Milk fat globules (MFGs) are a mixture of proteins and lipids with nutraceutical properties related to the milk fat globule membrane (MFGM), which protects them, thus preventing their coalescence. Human and bovine MFGM proteomes have been extensively characterized in terms of their formation, maturation, and composition. Here, we review the most recent comparative proteomic analyses of MFGM proteome, above all from humans and bovines, but also from other species. The major MFGM proteins are found in all the MFGM proteomes of the different species, although there are variations in protein expression levels and molecular functions across species and lactation stages. Given the similarities between the human and bovine MFGM and the bioactive properties of MFGM components, several attempts have been made to supplement infant formulas (IFs), mainly with polar lipid fractions of bovine MFGM and to a lesser extent with protein fractions. The aim is thus to narrow the gap between human breast milk and cow-based IFs. Despite the few attempts made to date, supplementation with MFGM proteins seems promising as MFGM lipid supplementation. A deeper understanding of MFGM proteomes should lead to better results.

Glycoprotein Filament Removal From Human Milk Fat Globules by Heat Treatment

PEDIATRICS ◽  
1988 ◽  
Vol 81 (1) ◽  
pp. 141-146
Author(s):  
Wolfgang Buchheim ◽  
Ulrich Welsch ◽  
Gail E. Huston ◽  
Stuart Patton
Keyword(s):  
Milk Fat ◽  
Electrophoretic Analysis ◽  
Fat Absorption ◽  
Fat Globules ◽  
Heated Milk ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Human Milk Fat ◽  
Additional Explanation

Freeze-etch electron microscopy was applied to milk fat globules to observe surface details. A remarkable array of filaments, approximately 0.5 µm in length, was seen on human, but not bovine, globules. Heating human globules removed the filaments that were identified as high molecular weight glycoproteins by freezeetch and gel electrophoretic analysis of the heating medium. Extraction of these globule glycoproteins was slight at 60°C for one minute but substantial and tending to plateau at 80°C for one minute. Such heat-induced alterations of the milk fat globule surface provide an alternative or additional explanation to milk lipase inactivation as the cause of reduced milk fat absorption from heated milk by the preterm infant.

Glycosphingolipids from bovine milk and milk fat globule membranes: a comparative study. Adhesion to enterotoxigenic Escherichia coli strains

2009 ◽  
Vol 390 (1) ◽  
Author(s):  
Fernando Sánchez-Juanes ◽  
Josefa M. Alonso ◽  
Lorena Zancada ◽  
Pablo Hueso
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Milk Fat ◽  
Fatty Acid Content ◽  
Fat Globules ◽  
Whole Milk ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Milk Fat Globule Membranes

AbstractSeveral components of milk fat globule membranes (MFGMs) have been reported to display beneficial health properties and some of them have been implicated in the defense of newborns against pathogens. These observations prompted us to determine the glycosphingolipid content of MFGMs and their interaction with pathogens. A comparative study with whole milk components was also carried out. Milk fat globules and MFGMs were isolated from milk. Gangliosides and neutral glycosphingolipids were obtained from MFGMs and whole milk and their fatty acid contents were determined by gas chromatography-mass spectrometry (GC-MS). MFGMs and whole milk showed similar ganglioside and neutral glycosphingolipid contents, with whole milk having more GM3 and glucosylceramide and less GD3,O-acetyl GD3,O-acetyl GT3, and lactosylceramide. The fatty acid content of gangliosides from both sources showed a similar composition. However, the neutral glycosphingolipid fatty acid content seemed to be quite different. Whole milk had fewer very-long-chain fatty acids (18.1% vs. 46.4% in MFGMs) and more medium-chain and unsaturated C18:1 and C18:2 fatty acids. Milk fat globules, MFGMs, lactosylceramide, and gangliosides GM3 and GD3 were observed to bind enterotoxigenicEscherichia colistrains. Furthermore, bacterial hemagglutination was inhibited by MFGMs and glycosphingolipids.

scholarly journals Characterization of an apically derived epithelial membrane glycoprotein from bovine milk, which is expressed in capillary endothelia in diverse tissues.

1985 ◽  
Vol 100 (2) ◽  
pp. 397-408 ◽  
Author(s):  
D E Greenwalt ◽  
I H Mather
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Milk Fat ◽  
Bovine Milk ◽  
Mammary Tissue ◽  
Specific Marker ◽  
Total Carbohydrate ◽  
Milk Fat Globule Membrane ◽  
Milk Fat Globule ◽  
Fat Globule

A glycoprotein (PAS IV) of apparent Mr 76,000 was purified from bovine milk-fat-globule membrane and partially characterized. PAS IV contained mannose, galactose, and sialic acid as principal sugars (approximately 5.3% total carbohydrate [wt/wt]) and existed in milk in at least four isoelectric variants. The glycoprotein appeared to be an integral membrane protein by several criteria. PAS IV was recovered in the detergent phase of Triton X-114 extracts of milk-fat-globule membrane at room temperature. When bound to membrane, PAS IV was resistant to digestion by a number of proteinases, although after solubilization with non-ionic detergents, the protein was readily degraded. Amino acid analysis of the purified protein revealed a high percentage of amino acids with nonpolar residues. The location of PAS IV was determined in bovine tissues by using immunofluorescence techniques. In mammary tissue, PAS IV was located on both the apical surfaces of secretory epithelial cells and endothelial cells of capillaries. This glycoprotein was also detected in endothelial cells of heart, liver, spleen, pancreas, salivary gland, and small intestine. In addition to mammary epithelial cells, PAS IV was also located in certain other epithelial cells, most notably the bronchiolar epithelial cells of lung. The potential usefulness of this protein as a specific marker of capillary endothelial cells in certain tissues is discussed.

scholarly journals The endoplasmic reticulum and casein-containing vesicles contribute to milk fat globule membrane

2016 ◽  
Vol 27 (19) ◽  
pp. 2946-2964 ◽  
Author(s):  
Edith Honvo-Houéto ◽  
Céline Henry ◽  
Sophie Chat ◽  
Sarah Layani ◽  
Sandrine Truchet
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Milk Fat ◽  
Milk Secretion ◽  
Milk Fat Globule Membrane ◽  
Fat Globules ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
Milk Fat Globule Membranes

During lactation, mammary epithelial cells secrete huge amounts of milk from their apical side. The current view is that caseins are secreted by exocytosis, whereas milk fat globules are released by budding, enwrapped by the plasma membrane. Owing to the number and large size of milk fat globules, the membrane surface needed for their release might exceed that of the apical plasma membrane. A large-scale proteomics analysis of both cytoplasmic lipid droplets and secreted milk fat globule membranes was used to decipher the cellular origins of the milk fat globule membrane. Surprisingly, differential analysis of protein profiles of these two organelles strongly suggest that, in addition to the plasma membrane, the endoplasmic reticulum and the secretory vesicles contribute to the milk fat globule membrane. Analysis of membrane-associated and raft microdomain proteins reinforces this possibility and also points to a role for lipid rafts in milk product secretion. Our results provide evidence for a significant contribution of the endoplasmic reticulum to the milk fat globule membrane and a role for SNAREs in membrane dynamics during milk secretion. These novel aspects point to a more complex model for milk secretion than currently envisioned.

Origin of Milk Fat Globules and the Nature of the Milk Fat Globule Membrane

1983 ◽  
pp. 83-118 ◽  
Author(s):  
T. W. Keenan ◽  
Daniel P. Dylewski ◽  
Terry A. Woodford ◽  
Rosemary H. Ford
Keyword(s):  
Milk Fat ◽  
Milk Fat Globule Membrane ◽  
Fat Globules ◽  
Milk Fat Globules ◽  
Milk Fat Globule ◽  
Fat Globule
Sign in / Sign up

Export Citation Format

Share Document