RT info:eu-repo/semantics/doctoralThesis
T1 Remodelado del calcio intracelular en el envejecimiento neuronal y los tumores cerebrales
A1 Hernando Pérez, María Elena
A2 Universidad de Valladolid. Escuela de Doctorado
K1 Cancer
K1 Aging
K1 Envejecimiento
K1 Intracellular calcium
K1 Calcio intracelular
K1 Alzheimer
K1 Alzheimer
K1 Glioblastoma
K1 Glioblastoma
K1 2411 Fisiología Humana
AB In this thesis we have investigated intracellular Ca2+ homeostasis, both at the functional and molecular level, in an in vitro model of neuronal aging and a series of brain tumors. First, changes in intracellular Ca2+ homeostasis have been investigated in neonatal rat hippocampal neurons cultured at short (young cells) and long term (aged in vitro), cultured in the presence and absence of oligomers of amyloid peptide (Aβo), the main toxin of Alzheimer's disease. The results show that store-operated Ca2+ entry (SOCE) decreases with aging, especially in the presence of Aβo. Furthermore, the SOCE agonist, MDEB, increases SOCE in young, but not in aged neurons. Neuronal aging decreases mitochondrial potential and increases reactive oxygen species (ROS), effects enhanced by Aβo, and which could explain the loss of SOCE and the lack of effect of MDEB. We also studied the role of the ER. We found that aging increases ER-mitochondria colocalization and IP3 receptor expression, but decreases the % of neurons releasing Ca2+ in response to caged IP3. Paradoxically, Aβo increases the % neurons releasing Ca2+ in response to caged IP3.  At the molecular level, transcriptomic analysis of neuronal cultures indicates that aging increases the expression of P2X4 and 5, the acetylcholine receptors mAChR1,2, the kainate receptor Gluk4, TRPM2 and 3 channels, the SOCE-involved proteins Stim1, Orai2, Saraf, Mbp, Septin4, and the intracellular receptors IP3R1,2 and RyR3. In parallel, aging decreases the expression of the T-type channel Cav2.2, the purinergic receptor P2Y1, the acetylcholine receptors mAChR3 and nAChRα7, the TRPML3 channel, Septin2,7,9,10 and 11, RyR2, and the mitochondrial systems Mcu, Micu2 and Vdac1,2 and 3. Treatment with Aβo did not produce significant changes in the transcriptome of aged hippocampal neurons.Second, intracellular Ca2+ homeostasis has been studied in primary cultures of benign human brain tumors (meningiomas and neurinomas), gliomas (oligodendrogliomas, astrocytomas and glioblastomas) and brain metastases. The results show that ATP increases [Ca2+]cit in malignant human brain tumors and metastases, but less so in benign tumors and oligodendrogliomas. Depolarization induces Ca2+ entry in glioblastomas, but not in all other tumors. SOCE is high in benign tumors, intermediate in gliomas and small in brain metastases. However, in gliomas, there is a positive correlation between malignancy and SOCE. Mitochondrial depolarization inhibits SOCE in gliomas, but not in oligodendrogliomas. SOCE inhibition inhibits glioblastoma cell proliferation. We subsequently performed transcriptomic analysis in glioblastomas. These tumors express high levels of Cav1.2, Cav1.3, Cav2.1, Cav3.1, Cav3. 2, P2X4,7, P2Y1,12 receptors, TRPC1, TRPV1, TRPM2,4,7, TRPML1 and TRPP1,2 channels, PMCA1,2,4 pumps, SERCA2, SPCA1, NCX1,3 exchangers, proteins responsible for SOCE ORAI1, 2,3, Stim1,2, STIMATE, ORMDL3, SARAF, Septin2,3,4,5,6,7,8,9,10,11, ER channels IP3R1,2 and RyR3 and all mitochondrial transport systems. Functional and molecular studies in paired samples from glioblastomas and peritumoral areas revealed differences in Ca2+ stores and ATP response, but not SOCE in paired samples. Differential expression analysis revealed that glioblastomas overexpress 3 channels, Cav3.2, TRPC6 and TRPV4 channels, and infraexpress Cav1.4 channels, P2X7 and P2Y2 receptors,12,13 TRPV3,5,6 and TRPM6 channels, and the modulators SEPTIN4 and MICU3. Global transcriptomic analysis of gene clusters indicates a strong transcriptomic resemblance between glioblastomas, lung, breast and cervical cancer tumors. These results could provide new opportunities for their treatment.
YR 2024
FD 2024
LK https://uvadoc.uva.es/handle/10324/67245
UL https://uvadoc.uva.es/handle/10324/67245
LA spa
NO Escuela de Doctorado
DS UVaDOC
RD 28-nov-2024