Analysis of Toll-Like Receptors in Human Milk: Detection of Membrane-Bound and Soluble Forms

The bioactive and anti-inflammatory role of human milk components has been recognized; active milk components include soluble forms of Toll-like receptors (TLRs). Preterm babies are more susceptible to infections and may succumb to necrotizing enterocolitis (NEC), a gastrointestinal disease which is exacerbated by an excessive inflammatory response after TLR activation. Here, we investigated the presence of Toll-like receptors TLR1/2/4/6 in colostrum and mature milk of women who delivered before (preterm) or after (term) 37 weeks of gestational age, integrating classical immune-related techniques with proteomic LC-MS/MS analysis. We have detected immunoreactivity for TLRs mostly in preterm samples, even for TLR1 and TLR6, until now not described in human milk. We demonstrated the presence of only TLR2 in the milk fat globule membrane, while the immunoreactivity of TLR1/4/6 was ascribed to crossreaction with some interesting milk proteins sharing leucine-rich repeat domains. These results will provide new insights into the definition of the role of TLRs in intestinal immune regulation of the newborns.

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In Vitro Digestion of Human Milk: Influence of the Lactation Stage on the Micellar Carotenoids Content

Antioxidants ◽

10.3390/antiox8080291 ◽

2019 ◽

Vol 8 (8) ◽

pp. 291 ◽

Cited By ~ 2

Author(s):

Xavier ◽

Garrido-López ◽

Aguayo-Maldonado ◽

Garrido-Fernández ◽

Fontecha ◽

...

Keyword(s):

Human Milk ◽

Milk Fat ◽

In Vitro Digestion ◽

Lactation Period ◽

Mature Milk ◽

Lactation Stage ◽

Lactating Mothers ◽

External Standard Method ◽

Milk Fat Globule

Human milk is a complex fluid with nutritive and non-nutritive functions specifically structured to cover the needs of the newborn. The present study started with the study of carotenoid composition during progress of lactation (colostrum, collected at 3–5 d postpartum; mature milk, collected at 30 d postpartum) with samples donated from full-term lactating mothers (women with no chronic diseases, nonsmokers on a regular diet without supplements, n = 30). Subsequently, we applied an in vitro protocol to determine the micellarization efficiency of the carotenoids, which were separated by HPLC and quantified by the external standard method. That in vitro protocol is tailored for the biochemistry of the digestive tract of a newborn. To the best of our knowledge, the present study is the first report of carotenoids micellar contents, obtained in vitro. This study reveals, from the in vitro perspective, that colostrum and mature milk produce significant micellar contents of carotenoids despite lipids in milk are within highly complex structures. Indeed, the lactation period develops some influence on the micellarization efficiency, influence that might be attributed to the dynamics of the milk fat globule membrane (MFGM) during the progress of lactation.

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Lipids in Milk and the First Steps in Their Digestion

PEDIATRICS ◽

10.1542/peds.75.1.146 ◽

1985 ◽

Vol 75 (1) ◽

pp. 146-150

Author(s):

Margit Hamosh ◽

Joel Bitman ◽

D. Larry Wood ◽

P. Hamosh ◽

N. R. Mehta

Keyword(s):

Human Milk ◽

Milk Fat ◽

Partial Hydrolysis ◽

Mature Milk ◽

Fat Globules ◽

Total Milk ◽

Milk Fat Globules ◽

Milk Fat Globule ◽

Fat Globule ◽

Hydrolysis Of

Human milk contains 3.0% to 4.5% fat. The fat is contained within membrane-enclosed milk fat globules. The core of the globules consists of triglycerides (98% to 99% of total milk fat) whereas the globule membrane (which originates from the mammary secretory cell's Golgi and cell membranes) is composed mainly of phospholipids, cholesterol, and proteins. Milk fat content and composition change during lactation. Whereas the triglyceride level rises, the phospholipid and cholesterol concentrations decrease during the transition from colostrum to mature milk, resulting in an increase in the size of the milk fat globules. Digestion of milk fat depends on the consecutive action of several lipases. The first step is the partial hydrolysis of the milk fat globule core by lingual and gastric lipases in the stomach. Hydrolysis continues in the duodenum, where the bile salt-stimulated lipase of human milk and pancreatic lipase complete the process initiated in the stomach.

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Effect of pasteurization on the enzymatic cross-linking of milk proteins by microbial transglutaminase in view of milk fat globule membrane isolation

Food Bioscience ◽

10.1016/j.fbio.2021.101100 ◽

2021 ◽

pp. 101100

Author(s):

Fatma Ali ◽

Zheng-Xiang Wang

Keyword(s):

Milk Fat ◽

Milk Proteins ◽

Microbial Transglutaminase ◽

Cross Linking ◽

Milk Fat Globule Membrane ◽

Milk Fat Globule ◽

Fat Globule ◽

Membrane Isolation

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Structure of the human milk fat globule

Lipid Technology ◽

10.1002/lite.201300303 ◽

2013 ◽

Vol 25 (10) ◽

pp. 223-226 ◽

Cited By ~ 13

Author(s):

Cyrielle Garcia ◽

Sheila Innis

Keyword(s):

Human Milk ◽

Milk Fat ◽

Milk Fat Globule ◽

Fat Globule ◽

Human Milk Fat

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Isolation and characterization of two individual glycoprotein components from human milk-fat-globule membranes

Biochemical Journal ◽

10.1042/bj2070037 ◽

1982 ◽

Vol 207 (1) ◽

pp. 37-41 ◽

Cited By ~ 14

Author(s):

A Imam ◽

D J Laurence ◽

A M Neville

Keyword(s):

Human Milk ◽

Milk Fat ◽

Sodium Dodecyl ◽

Membrane Glycoproteins ◽

Lectin Affinity Chromatography ◽

Isolation And Characterization ◽

Milk Fat Globule ◽

Fat Globule ◽

Milk Fat Globule Membranes ◽

Human Milk Fat

Two individual glycoprotein components from human milk-fat-globule membranes (MFGM) has been purified by selectively extracting the membrane glycoproteins followed by lectin affinity chromatography and gel filtration on Sephadex G-200 in the presence of protein-disaggregating agents. The purified glycoprotein components, termed ‘epithelial-membrane glycoprotein’ (EMGP-155 and EMGP-39) have estimated molecular weights of 155 000 and 39 000 respectively, and yield a single band under reducing conditions on sodium dodecyl sulphate/polyacrylamide gel. EMGP-155 and EMGP-39 contain 21.0% and 7.0% carbohydrate by weight, with fucose (13.5%, 12.4%), mannose (3.7%, 6.2%), galactose (28.5%, 22.6%), N-acetylglucosamine (17.8%, 7.4%) and sialic acid (36.4%, 51.4%) of the carbohydrate moiety respectively. For both the glycoprotein components, aspartic and glutamic acid and serine are the major amino acid residues.

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Radiation doses obtained from 99mTc-labelled human milk fat globule monoclonal antibodies

Nuclear Medicine and Biology ◽

10.1016/0969-8051(93)90106-5 ◽

1993 ◽

Vol 20 (2) ◽

pp. 145-148

Author(s):

M.M. Calitz ◽

A. Van Aswegen ◽

M.M.J. Van Der Merwe ◽

M.G. Lötter

Keyword(s):

Monoclonal Antibodies ◽

Human Milk ◽

Milk Fat ◽

Radiation Doses ◽

Milk Fat Globule ◽

Fat Globule ◽

Human Milk Fat

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A novel FADS2 isoform identified in human milk fat globule suppresses FADS2 mediated Δ6-desaturation of omega-3 fatty acids

Prostaglandins Leukotrienes and Essential Fatty Acids ◽

10.1016/j.plefa.2018.06.004 ◽

2018 ◽

Vol 138 ◽

pp. 52-59 ◽

Cited By ~ 2

Author(s):

Kumar S.D. Kothapalli ◽

Hui Gyu Park ◽

Xiaoxian Guo ◽

Xuepeng Sun ◽

James Zou ◽

...

Keyword(s):

Fatty Acids ◽

Human Milk ◽

Milk Fat ◽

Omega 3 Fatty Acids ◽

Omega 3 ◽

Milk Fat Globule ◽

Fat Globule ◽

Human Milk Fat

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Glycoproteins of the Human Milk Fat Globule Membrane: Ultrastructure and Relation to Fat Absorption

Human Lactation 3 ◽

10.1007/978-1-4899-0837-7_43 ◽

1987 ◽

pp. 373-373

Author(s):

Stuart Patton ◽

Wolfgang Buchheim ◽

Ulrich Welsch

Keyword(s):

Human Milk ◽

Milk Fat ◽

Fat Absorption ◽

Milk Fat Globule Membrane ◽

Milk Fat Globule ◽

Fat Globule ◽

Membrane Ultrastructure ◽

Human Milk Fat

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336. Surface activity and proteins of milk

Journal of Dairy Research ◽

10.1017/s0022029900004775 ◽

1946 ◽

Vol 14 (3) ◽

pp. 316-329 ◽

Cited By ~ 34

Author(s):

R. Aschaffenburg

Keyword(s):

Milk Fat ◽

Chemical Nature ◽

Active Material ◽

Milk Proteins ◽

Residual Fraction ◽

Total Milk ◽

Surface Active ◽

Surface Active Material ◽

Dilution Curves

As moderate dilution causes little change in the surface tension of milk, it is shown to be advantageous to use σ-dilution curves in place of the σ-values of the undiluted fluid as a characteristic of the surface properties of milk. The complications arising from the presence of the milk fat are described, and it is suggested that the influence of the fat is of a physical rather than of a chemical nature. A study of the role of the various milk proteins shows the casein to be of great importance, whilst the heat-coagulable proteins have little influence. The serum obtained after removal of the casein and heat-coagulable proteins contains a residual fraction of protein-like material which is markedly surface active though constituting only about 3% of the total milk proteins. The surface-active material (σ-proteose) has been concentrated and isolated, and its properties are described in some detail.

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