Ilona Concha Grabinger

Academic Training

  • Scientific Baccalauréat, Universidad Austral de Chile, Chile,1981;
  • Masters degree, Molecular Biology, Universidad Austral de Chile, Chile, 1981;
  • Ph.D., Cell and Molecular Biology, Universidad Austral de Chile, Chile, 1994;
  • Postdoctorate, Memorial Sloan Kettering Cancer Center, USA; 1995.

Scientific Interests

For years our group has been interested in the fascinating model of cell differentiation in the seminiferous tubule. In this environment, male germ cells proliferate and differentiate in close relation with Sertoli cells. We have been interested in the metabolic aspects of transport systems, facilitative hexose transporters (GLUTs) and sodium-ascorbic acid co-transporters (SVCTs) and cytokine receptor expression that detects increased uptake of hexose and vitamin C and thus influences proliferation, differentiation and survival of these cells. Recently, we have studied the relation between the capacity for vitamin C transport through the hemato-testicular barrier and oxidative stress in the seminiferous tubule. We are also interested in studying the physiological context of vitamin C transporters in other cell types, particularly in nervous tissue.

Our more recent attention is focused on glycogen content in the seminiferous tubule. For many years glycogen stores have been considered only as a source of energy for different metabolic processes. However, the presence of glycogen (or glucose polymers) in different cell types may have a devastating effect on cells, even provoking cell death. In mammals, during spermatogenesis, much apoptotic activity occurs in germ cells as well as large fluctuations in the levels of testicular glycogen. This would suggest that regulation of glycogen during the first waves of spermatogenesis is a delicate process. To date, there is no evidence to directly link both events nor is it clear which mechanisms may regulate them. We wish to establish the mechanism that regulates testicular glycogen content, if it is similar to that already proposed for brain tissue and whether an imbalance in glycogen homeostasis may be responsible for male infertility in mammals.

Proyects:

  • Study of the regulatory mechanism of testicular glycogen content: Participation of Malin and Laforin FONDECYT 1110508 Investigadora Responsable
  • Impaired homeostasis of Ascorbic Acid in Huntington Disease: From the animal model to the clinic FONDECYT 1110571 Co-Investigadora
  • Fructose-1,6-bisphosphatase a key protein in cell physiology: studies of changes of its structure and activity mechanisms which may originate aberrations in thecarbohydrate metabolism as observed in diabetes and autism FONDECYT  1141033 Co-Investigadora
  • La localización subcelular de Fructosa 1,6-Bisfosfatasa y su interacción con Fructosa 1,6-Bisfosfato Aldolasa y Glicógeno Sintasa regulan la síntesis de glucosa y glicógeno en células hepáticas, musculares y astrocitos FONDECYT 1090740 Co-Investigadora

 

Relevant Publications

  • Asenjo JL, Ludwig HC, Droppelmann CA, Cárcamo JG, Concha II, Yáñez AJ, Cárdenas ML, Cornish-Bowden A, Slebe JC. “Subunit interactions in pig-kidney fructose-1,6-bisphosphatase: binding of substrate induces a second class of site with lowered affinity and catalytic activity”. Biochim Biophys Acta. 2014 Jun;1840(6):1798-807. doi: 10.1016/j.bbagen.2013.12.027. Epub 2014 Jan 18.
  • Acuña AI; Esparza M; Kramm C; Beltrán FA; Parra, AV; Cepeda C; Toro CA; Vidal RL, Hetz C; Concha II, Brauchi S, Levine MS; Castro MA “ A failure in energy metabolismo and antioxidante uptake precede symptoms of Huntington’s disease in mice”. Nat Commun. Dec 13;4:2917. doi: 10.1038/ncomms3917. (2013).
  • Villarroel-Espíndola  F; Maldonado  R; Mancilla  H; vander Stelt  K, Acuña A; Covarrubias A; López C; Angulo C; Castro M A; Slebe, JC; Durán J; García-Rocha M; Guinovart J J and Concha II. “Muscle glycogen synthase isoform is responsible for testicular glycogen synthesis: glycogen overproduction induces apoptosis in male germ cells” JCell Biochem Jul;114(7):1653-64. doi: 10.1002/jcb.24507 (2013).
  • Mardones L, Zúñiga FA, Villagrán M, Sotomayor K, Mendoza P, Escobar D, González M, Ormazabal V, Maldonado M, Oñate G, Angulo C, Concha II, Reyes AM, Cárcamo JG, Barra V, Vera JC, Rivas CI “Essential role of intracellular glutathione in controlling ascorbic acid transporter expression and function in rat hepatocytes and hepatoma cellsFree Radic Biol Med. 52(9): 1874-1887 (2012).
  • Zambrano, A, Jara, E, Murgas, P, Jara, C, Castro, Angulo, Concha, II  “Cytokine stimulation promotes increased glucose uptake via intracellular trafficking of GLUT1 in HEK293 cells” J Cell Biochem 110: 1471-1480 (2010). 
  • Ramírez, A., Castro, M.A., Angulo, C., Ramió, L., Rivera, M., Torres, M., Rigau, T., Rodríguez-Gil, J.E., Concha, II “The presence and function of dopamine type-2 receptors in boar sperm: a possible role for dopamine in viability, capacitation and modulation of sperm motility” Biol Reprod 80: 753-761 (2009).
  • Angulo, C., Castro, M. A., Rivas, C., Segretain, D., Maldonado, R., Yañez, A.J., Slebe, J.C., Vera, J.C., and Concha, II, "Molecular Identification and Functional Characterization of the Vitamin C transporters expressed by Sertoli cells" J Cell Physiol 217: 708-716 (2008).
  • Castro, M.A., Angulo, C., Brauchi, S., Nualart, F. and Concha, II "Ascorbic acid participates in a general mechanism for concerted glucose transport inhibition and lactate transport stimulation". Pflügers Arch. 457(2):519-28 (2008).
  • Rauch, M.C., Ocampo, M.E., Bohle,J., Amthauer, R., Yáñez, A., Rodriguez-Gil, J.E., Slebe, J.C., Reyes, J.G. and Concha, II "Hexose transporters GLUT1 and GLUT3 are colocalized with hexokinase I in caveolae microdomains of rat spermatogenic cells" J Cell Physiol 207, 397-406 (2006).
  • Rauch, M.C., Brito, M., Zambrano, A., Espinoza, M., Pérez, M., Yañez, A., Rivas, C.I., Slebe, J.C. and Concha, II "Differential signaling for enhanced hexose uptake by IL-3 and IL-5 in male germ cells" Biochem J 381, 495-501. (2004).
  • Angulo, C., Rauch, M.C., Droppelmann, A., Reyes, A.M., Slebe, J.C., Delgado-López, F., Guaiquil, V.H., Vera, J.C., and Concha, II "Hexose transporter expression and function in mammalian spermatozoa: Cellular localization and transport of hexoses and vitamin C" J Cell Biochem 71, 189-203. (1998).
  • Vera, J.C., Rivas, C.I., Velázquez, F.V., Zhang, R.H., Concha, II and Golde, D.W. "Resolution of the facilitated transport of dehydroascorbic acid from its reduction-dependent intracellular accumulation". J Biol Chem 270, 23706-23712. (1995).