Effects of glucose on lactose synthesis in mammary epithelial cells from dairy cow

Abstract

BackgroundLactose, as the primary osmotic component in milk, is the major determinant of milk volume. Glucose is the primary precursor of lactose. However, the effect of glucose on lactose synthesis in dairy cow mammary glands and the mechanism governing this process are poorly understood.ResultsHere we showed that glucose has the ability to induce lactose synthesis in dairy cow mammary epithelial cells, as well as increase cell viability and proliferation. A concentration of 12 mM glucose was the optimum concentration to induce cell growth and lactose synthesis in cultured dairy cow mammary epithelial cells. In vitro, 12 mM glucose enhanced lactose content, along with the expression of genes involved in glucose transportation and the lactose biosynthesis pathway, including GLUT1, SLC35A2, SLC35B1, HK2, β4GalT-I, and AKT1. In addition, we found that AKT1 knockdown inhibited cell growth and lactose synthesis as well as expression of GLUT1, SLC35A2, SLC35B1, HK2, and β4GalT-I.ConclusionsGlucose induces cell growth and lactose synthesis in dairy cow mammary epithelial cells. Protein kinase B alpha acts as a regulator of metabolism in dairy cow mammary gland to mediate the effects of glucose on lactose synthesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0704-x) contains supplementary material, which is available to authorized users.

Ameliorative Effect of Infused Watercress on Rat Galactopoiesis following Maternal Separation

“…Caseins and whey acidic protein synthesis are stimulated by hormonal regulation via Signal Transducer and Activator of Transcription 5 (STAT5) activation during gestation [8]. Milk lactose is synthetized from glucose and UDP-galac-tose at the Golgi apparatus [9]. Triglyceride is synthetized from glucose, glyceride, and fatty acids at the surface of rough endoplasmic reticulum.…”

Effects of Pre-milking Resting on Some Lactation Characteristics of Damascus (Shami) and Kilis Goats

“…As reported by Ollier et al (2007), lactose synthesis is mostly dependent on genetic factors rather than feeding. When compared with Kilis breed, Shami breed with high lactose content had a high milk yield since lactose synthesis could be resulted in an increase in milk volume (Lin et al, 2016). …”

Involução da glândula mamária durante o final da lactação e período seco de cabras Saanen: respostas de sobrevivência celular ao estresse agudo e relações com a temperatura por infravermelho

“…Assim, a sinalização da Akt1 ocorre de maneira dependente da PI3K (induzida por fatores de crescimento), onde a subunidade catalítica (PIP3) da PI3K fosforila a Akt1 (Figura 4) (SCHERTFEGER; RICHERT; ANDERSON, 2001;LIN et al, 2016).…”

“…Nas células epiteliais mamárias, a Akt1 auxilia na regulação da síntese de leite e de proteínas do leite . Seu mecanismo de ação está em estimular o transporte de glicose através da proteína transportadora de glicose 1 (GLUT1) e, consequentemente aumentar a captação de glicose pelas células epiteliais mamárias (BOXER et al, 2006;LIN et al, 2016 Atualmente os testes para monitoramento de mastites, especialmente as subclínicas, utilizam a técnica de CCS e cultivos bacterianos. Assim, concentrações mais elevadas de CCS são indicadores de infecções intramamárias clínicas e subclínicas (BERGONIER et al, 2003).…”

“…), enquanto que as proteínas κ-e βcaseína são menos expressas após 36 horas.Dentre as proteínas do leite, a LALBA é uma proteína chave da lactação, pois está intimamente ligada à produção de leite, participando da via de síntese da lactose através do complexo enzimático β-1,4-galactosiltransferase, o qual catalisa a formação da lactose a partir de uma molécula de glicose e galactose(LIN et al, 2016). Além disso, através do seu papel osmótico, a lactose auxilia na regulação do volume de leite e a atividade secretória das células epiteliais mamárias(SHI et al, 2015;RILEY et at., 2008a).…”