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Milk bioactive components
No full textL’importanza del colostro e del latte nella nutrizione dei mammiferi è ampiamente riconosciuta. Essi sono in grado di fornire non solo composti con un elevato valore nutrizionale per la crescita del neonato, ma anche molecole bioattive con valenza extra-nutrizionale. Le proteine del latte sono la fonte principale di peptidi bioattivi, latenti nella proteina nativa e rilasciati in seguito a proteolisi durante il transito gastrointestinale. Tra le molecole bioattive del latte con rilevanti funzioni fisiologiche si possono annoverare anche gli oligosaccaridi e i lipidi, quali i coniugati dell’acido linoleico, presenti in particolare nel latte dei ruminanti. La lattoferrina esemplifica la complessità delle componenti biologicamente attive del latte ed esplica numerose funzioni fisiologiche. Ha attività immunomodulatoria e anti-infiammatoria, è coinvolta nella regolazione dell’omeostasi del ferro, modula la crescita cellulare ed esercita un’azione prebiotica. In questa presentazione si fornirà un panorama del significato funzionale delle componenti bioattive del latte con particolare riferimento alla lattoferrina
La lattoferrina come molecola bioattiva : valutazione dell'attività biologica mediante modelli in vitro e potenzialità legate all'espressione in sistemi eterologhi
No full texteveral compounds secreted by the mammary gland in colostrum and milk have been identified as biologically active substances. Among these, there is lactoferrin (LF), an 80 KDa non-haem iron binding glycoprotein. Physiological roles of LF include regulation of iron absorption, immune response modulation, antimicrobial, antiviral and anticarcinogenic activities, prebiotic support to intestinal microflora and trophic effect on intestinal mucosa. The aim of this PhD thesis was the study of lactoferrin s functional properties using several in vitro models of mammary and intestinal epithelium. Moreover, the possibility to express porcine lactoferrin in heterologous expression systems, such as yeasts and plants, was investigated. Our results showed that LF could be involved as regulatory factor in the modulation of mammary and intestinal cell lines growth and that this effect may be exerted by cellular internalization of the protein. Moreover, pregnant and lactating mammary tissue incubated with drugs that block protein synthesis showed that LF localization appeared to differ somewhat from that of other milk proteins, suggesting a role in modulating mammary development. Finally, porcine LF expressed in Pichia pastoris yeast retained his antibacterial and prebiotic activities and the creation of a chimeric construct to express porcine LF in rice will give the opportunity to obtain transgenic plants as nutraceutical
Three dimensional acinar cultures of mammary epithelium as an in vitro model for studying hormonal mechanisms in the mammary gland
No full textBackground: Three dimensional (3D) acinar cultures from primary mammary epithelial cells have been used as in vitro strategies to study mammary growth and differentiation. Primary epithelial cells cultured on a reconstituted basement membrane matrix are able to form functional alveolar-like multicellular structures with a luminal compartment and to secrete milk proteins in a vectorial manner. However, the validation of 3D acinar cultures for elucidating functional mammary development requires the study of the hormone dependence of growth and differentiation of acini in vitro. Aim: The aim of this study was to characterize the hormone dependence of growth and functional differentiation of acinar cultures derived from the pregnant gland, with emphasis on insulin. Methods: Acini are dissociated by collagenase digestion of #4 and 5 mammary glands from 14 day pregnant CD1 mice. In some experiments organoids were treated with trypsin and filtered through a 70 um cell strainer to obtain single cells. Organoids or single cells are grown embedded in 100% Matrigel in the following growth medium: DMEM-F12 with insulin (concentrations tested: 870 nM, 100 nM, 50 nM), EGF (5 ng/ml), Prolactin (PRL; 3 ug/ml), hydrocortisone (HC; 1 ug/ml) and fetal bovine serum (FBS; 5%). After one week in culture, the EGF and serum are removed to obtain differentiation medium. After another week, acini are fixed, embedded in paraffin and sectioned. Immunohistochemistry is carried out using primary antibodies for casein and ADPH. Results: In standard culture in differentiation medium, staining for ADPH and casein revealed CLD formation and movement of casein from the cytoplasm to the lumen. Removal of PRL from the differentiation medium resulted in smaller CLD and reduced casein, while removal of HC resulted in casein remaining in the cytoplasm. Insulin was required to support the organization of functional acini from mammary organoids so the omission of insulin resulted in more disordered assemblies showing incomplete lumen formation. Also, the multicellular structures formed from organoids were smaller and fewer in number. Moreover, insulin was required to promote acinar formation starting with single cells. Many acini in good shape were detected with insulin at 870 nM (supraphysiological concentration used in in vitro mammary cultures). A good response was obtained with insulin at 100 and 50 nM as well. Conclusions: Taken together these data demonstrate that 3D acinar cultures respond to hormones as observed in other mammary preparations. They also suggest that this in vitro model will be useful to elucidate signaling pathways utilized by hormones to regulate mammary growth and differentiation in pregnancy. In addition, these results provide evidence that insulin is a critical hormone that supports the organization of mammary epithelial cells in alveolar-like structures, capable of functional differentiation
La lattoferrina come componente bioattiva del latte : valutazione dell’attività biologica mediante l’impiego di cellule epiteliali di ghiandola mammaria bovina in vitro
No full textNutrition in mammary gland health and lactation : advances over eight Biology of Lactation in Farm Animals meetings.
No full textOver the years, numerous studies have investigated the mechanisms controlling nutrient availability and metabolism in the mammary gland and how dietary interventions can influence these processes. The development of in vivo and in vitro systems made it possible to explore the trafficking and metabolic fate of nutrients and how these are influenced by hormones. To improve the quality and safety of milk products, attention has focused on improving animal health in general and mammary gland health in particular and also on enhancing the milk content of natural bioactive milk components that promote the health of human neonates and adults. In the past, attempts to probe the relationship among nutrition, animal health, and animal products were limited to administering single dietary components and investigating their biochemical and metabolic effects. Today, we have genomics, proteomics, and related technologies that allow us to pursue more holistic investigational strategies. These new technologies are providing new insights into interactions among nutrition, lactation, and product quality. The aim of this paper is to review advances in nutritional support of mammary gland function and health as presented in 14 yr of Biology of Lactation in Farm Animals (BOLFA) meetings
La lactoferrine est localisée dans les regions apicales et basales de l'épithélium mammaire de souris
No full textTests in vitro per la valutazione dell'attività biologica di lattoferrina suina ricombinante
No full textAdministration of biogenic amines to Saanen kids : effects on growth performance and meat quality
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