Browsing by Author "Santander Grez, Nicolás Guillermo"

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    Deficient Vitamin E Uptake During Development Impairs Neural Tube Closure in Mice Lacking Lipoprotein Receptor SR-BI
    (2017) Santander Grez, Nicolás Guillermo; Lizama, Carlos; Parga Ponce, María José; Quiroz Vallverdu, Alonso Ingmar; Pérez Pons, Druso Diego; Echeverría Errázuriz, Guadalupe; Ulloa, Lorena; Palma, Verónica; Rigotti Rivera, Attilio; Busso, Dolores
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    High density lipoprotein cholesterol and proteome in SR-B1 KO mice: lost in precipitation
    (2018) Contreras Duarte, Susana de las Mercedes; Santander Grez, Nicolás Guillermo; Rigotti Rivera, Attilio; Busso, Dolores; Birner-Gruenberger, Ruth.; Wadsack, Christian.
    Abstract Scavenger receptor class B type 1 (SR-B1) plays an essential role in high density lipoprotein (HDL) metabolism. SR-B1 deficient (SR-B1 KO) mice are prone to atherosclerosis and exhibit abnormally large, cholesterol-rich, dysfunctional HDL. In a recent issue of J Transl Med, Cao et al. described results of proteomics analyses of HDL isolated from wild-type (WT) and SR-B1 KO mice using precipitation of large lipoproteins with polyethylene glycol (PEG). They report abnormalities in SR-B1 KO HDL protein components that correlate with HDL function. In this commentary, we describe and discuss the differences in the results published by Cao et al. and those obtained in a recent study from our laboratory using shotgun proteomics of HDL of SR-B1 KO mice isolated by ultracentrifugation. We propose that different HDL purification procedures used may account for the discrepancies observed. We show that SR-B1 KO HDL purification using either PEG or dextran sulfate precipitation results in enrichment of small HDL subclasses, and may therefore underestimate alterations in lipoprotein composition or function. Compared to HDL obtained by ultracentrifugation, HDL isolated by PEG precipitation show a lower ApoE/ApoA-I proportion and reduced cholesterol content. HDL protein components described by Cao et al. or our laboratory are mostly inconsistent: only 33 HDL proteins were detected in both datasets, whereas a significant number of proteins were only identified by Cao et al. (n = 43) or Contreras-Duarte et al. (n = 26) datasets. The relative abundance of HDL-associated peptide and protein levels in WT vs SR-B1 HDL were also highly different in both datasets. This study indicates that caution must be taken when interpreting results from HDL isolated by chemical precipitation.
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    Nutrients and Gene Expression in Development
    (ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD, 2020) Busso, Dolores; Santander Grez, Nicolás Guillermo; Salas Pérez, Francisca Lorena; Santos Martín, José Luis; De Caterina, Raffaele; Martinez, J. Alfredo; Kohlmeier, Martín
    Development encompasses the formation of a complex organism starting from a unicellular zygote. This process requires finely tuned changes in gene expression across several cells and tissues, which may be regulated by a combination of stable and dynamic epigenetic modifications that make the DNA more or less accessible to transcriptional regulators. Diverse interdependent epigenetic mechanisms have been described, including DNA and histone methylation, histone acetylation, and silencing by micro RNAs. In the developing embryo or fetus, the epigenetic status is influenced by diverse environmental conditions, including maternal nutrition. Depending on the stage of pregnancy, gestational nutritional inadequacies may lead to congenital embryonic defects, suboptimal fetal growth, and/or reprogramming of tissues, which may determine different phenotypes or predispose individuals to chronic diseases later in life. During early pregnancy, abnormal methylation of certain genes resulting from nutritional inadequacies has been shown to increase the risk for congenital malformations that lead to perinatal death or postnatal disabilities. During mid to late pregnancy, maternal malnutrition, both undernutrition and overnutrition, has been shown to promote adaptive epigenetic changes in different organs that allow the embryo or fetus to cope with the intrauterine environment but that persist throughout life and may increase susceptibility to chronic diseases. Preconceptional nutrition in the mother, and paternal nutrition, also influence the epigenetic marks in the embryo. Nutrition seems to use epigenetics to tailor diversity and susceptibility to disease in animals and humans. Understanding nutrigenomics may be useful to understand evolution and promote health in future generations.
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    Ovarian cholesterol efflux : ATP-binding cassette transporters and follicular fluid HDL regulate cholesterol content in mouse oocytes
    (2020) Quiroz Vallverdu, Alonso Ingmar; Molina, P.; Santander Grez, Nicolás Guillermo; Gallardo, D.; Rigotti Rivera, Attilio; Busso, Dolores