Milk-derived growth factors as serum supplements for the growth of fibroblast and epithelial cells

Abstract

We have investigated the response of several epithelial and fibroblastic cells to a mitogenic extract of bovine milk. Cation exchange chromatography was used to produce a mitogen-rich fraction from an industrial whey source that, although comprising only 0.5% of total whey protein, contained the bulk of the growth factor activity. This fraction was a source of potent growth promoting activity for all mesodermal-derived cells tested, including human skin and embryonic lung fibroblasts, Balb/c 3T3 fibroblasts, and rat L6 myoblasts. Maximal growth of all these cell types exceeded that observed in 10% fetal bovine serum. Feline kidney and baby hamster fibroblasts and Chinese hamster ovary cells were less responsive, achieving a maximal growth response of 50-75% that observed in 10% fetal bovine serum. Maximal growth achieved in whey-extract-supplemented cultures of Balb/c 3T3 and human skin fibroblasts, and L6 myoblast cultures exceeded that seen in response to recombinant acidic or basic fibroblast growth factor, platelet-derived growth factor, insulin-like growth factor, or epidermal growth factor. Importantly, addition of low concentrations of fetal bovine serum to the whey-derived mitogenic fraction produced an additive response. However, concentrated milk-derived factors were found to be inhibitory to the growth of all epithelial lines tested, including rat intestinal epithelial cells, canine kidney epithelial cells, and mink lung cells. It is concluded that industrial whey extracted in this form constitutes an important source of potent growth-promoting agents for the supplementation of mesodermal-derived cell cultures.

Propriedades fisiológicas-funcionais das proteínas do soro de leite

“…No conjunto, essas substâncias têm sido chamadas de fatores de crescimento celular, incluindo neste grupo, além da lactoferrina 18 , uma série de polipeptídios, incluindo os fatores de crescimento semelhantes à insulina I e II (IGF-I e IGF-II), fatores ácidos e básicos de estímulo ao crescimento de fibroblastos (aFGF, bFGF), fatores de transformação de tecidos (TGF-β 1 e TGF-β 2 ), além de vários outros não identificados 69 . No conjunto, essas substâncias estimulam a proliferação (mitogênese) de variados tipos de células, podendo substituir, em boa parte, o soro fetal bovino comercializado com esta finalidade.…”

“…No conjunto, essas substâncias estimulam a proliferação (mitogênese) de variados tipos de células, podendo substituir, em boa parte, o soro fetal bovino comercializado com esta finalidade. Pesquisadores australianos 69 estabeleceram metodologias em nível piloto, para o isolamento desses fatores do soro de leite, como um concentrado, estudando sua ação não somente como estimulador do crescimento celular, mas também, como agente reparador de feridas crônicas 70 . Um extrato total desses fatores de crescimento estimulou o crescimento de fibroblastos com potência várias vezes maior que o observado para o soro fetal bovino.…”

Effect of Milk Renewal on Cell Viability In Vitro at Different Time Frames

“…Besides having low bacterial content (3,4), physiologic osmolality (230-270 mOsm/kg) and neutral pH (6.5-6.8), it provides the cells with nutrients (3) and growth factors (12,13). Although there has been some controversy (6,8), it has been suggested that milk with a lower fat content might be more appropriate to maintain PDLF viability than milk with a higher fat content (14).…”

Identification of betacellulin as a major peptide growth factor in milk: purification, characterization and molecular cloning of bovine betacellulin

“…This whey growth factor extract (WGFE) has been shown to be remarkably potent in stimulating the growth in itro of cells of mesodermal origin, including rat L6 myoblasts and Balb\c 3T3 fibroblasts [31]. Several growth factors have been identified in this extract, including fibroblast growth factors 1 and 2 (FGF-1 and FGF-2) [32], IGF-I and IGF-II, PDGF and TGF-β [33].…”