Autophagy as a main driver on Smith-Lemli-Opitz syndrome

Cardoso, Maria Luís

Publication

Autophagy as a main driver on Smith-Lemli-Opitz syndrome

2018-05-25Lecture

dc.contributor.author	Cardoso, Maria Luís
dc.date.accessioned	2019-02-08T10:43:39Z
dc.date.available	2019-02-08T10:43:39Z
dc.date.issued	2018-05-25
dc.description.abstract	Introduction: Cholesterol is an important structural component of cellular membranes and myelin and it was found to play an essential role on embryogenesis and development. In the past most of the scientific investigations concerning this lipid were focused on the consequences of high levels of cholesterol and only a few studies reported the dramatic consequences of low cholesterol levels for cells. In the present investigation we used fibroblasts from Smith-Lemli-Opitz syndrome patients (SLOS) - a metabolic genetic disease affecting the cholesterol biosynthesis pathway - to investigate the consequences of cholesterol deficiency on cell morphology and protein expression. Materials and methods: Morphological studies (MTT test, immunocytochemistry for LC3, MDC and acridine orange coloration as well as electron microscopy) and proteomic analysis (iTRAQ LC /MS-MS) were performed on fibroblasts from SLOS patients and human controls, simultaneously cultivated both on standard conditions and cholesterol depleted media. Results: Morphological studies showed that when endogenous synthesis of cholesterol is inadequate (SLOS) and there is no appropriate supply to overcome cellular needs (cholesterol depleted media), cell proliferation in vitro becomes impaired and autophagy is activated. Once, activation of autophagy, in the absence of cholesterol seems to be a self-rescue mechanism of the cell, we further investigated if there was also changes in protein expression which support surviving cell adaptive modifications. SLOS cells in cholesterol depleted medium show an overexpression of a set of proteins. Mainly, these cells seems to increase MnSOD expression to combat oxidative stress derived from the increased amount of 7-dehydrocholesterol and its derivatives, caused by the inherited enzymatic deficiency and thus control cell proliferation, whereas heat shock 70 kDa protein 4, an autophagic protein (Atg2) also presents a cytoprotective activity and inhibits apoptosis. Conclusion: We conclude that the mechanism by which SLOS fibroblasts handles their metabolic deficit, involves autophagy which plays an important role in cell survival. Furthermore this work provided powerful indications that may be useful to expand the knowledge about the mechanisms involved in cellular pathophysiology of SLOS.	pt_PT
dc.description.version	N/A	pt_PT
dc.identifier.uri	http://hdl.handle.net/10400.18/5729
dc.language.iso	eng	pt_PT
dc.publisher	Instituto Nacional de Saúde Doutor Ricardo Jorge, IP	pt_PT
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/	pt_PT
dc.subject	7-dehydrocholesterol Reductase Deficiency	pt_PT
dc.subject	Smith-Lemli-Opitz Syndrome	pt_PT
dc.subject	Autophagy	pt_PT
dc.subject	Cholesterol Deficiency	pt_PT
dc.subject	Inborn Errors of Cholesterol Biosynthesis	pt_PT
dc.subject	iTRAQ	pt_PT
dc.subject	HSPA4	pt_PT
dc.subject	CaMKII	pt_PT
dc.subject	MnSOD	pt_PT
dc.subject	Doenças Cardio e Cérebro-vasculares	pt_PT
dc.title	Autophagy as a main driver on Smith-Lemli-Opitz syndrome	pt_PT
dc.type	lecture
dspace.entity.type	Publication
oaire.citation.conferencePlace	Lisboa, Portugal	pt_PT
oaire.citation.title	Palestras do DPSPDNT, INSA, 25 maio 2018	pt_PT
rcaap.rights	openAccess	pt_PT
rcaap.type	lecture	pt_PT