20 research outputs found

    ApoA-I nanodiskoen prestakuntza eta karakterizazioa

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    Lan honetan, A-I apolipoproteinaren nanodiskoak eratu eta karakterizatu dira in vivo agertzen diren HDL jaio-berriak imitatzeko. Horrez gain, nanodiskoen aktibitatea aztertzeko lehen esperimentuak burutu dira. Horrela, etorkizuneko helburua, mikroRNAk, RNA txiki ez-kodetzaile batzuk, edo horien inhibitzaileak (antagomiR edo antimiR) daramatzaten HDL sintetikoak eratzea da. Hala, molekula horiek modu espezifikoan garraiatuak izan daitezke eta zelula apartsuak bezalako itu zeluletan, intereseko efektuak eduki dezakete, ateroma plakaren eraketaren inguruan zenbait aplikazio terapeutiko eskaintzen duena

    Validation of LDLr Activity as a Tool to Improve Genetic Diagnosis of Familial Hypercholesterolemia: A Retrospective on Functional Characterization of LDLr Variants

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    Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by high blood-cholesterol levels mostly caused by mutations in the low-density lipoprotein receptor (LDLr). With a prevalence as high as 1/200 in some populations, genetic screening for pathogenic LDLr mutations is a cost-effective approach in families classified as definite' or probable' FH and can help to early diagnosis. However, with over 2000 LDLr variants identified, distinguishing pathogenic mutations from benign mutations is a long-standing challenge in the field. In 1998, the World Health Organization (WHO) highlighted the importance of improving the diagnosis and prognosis of FH patients thus, identifying LDLr pathogenic variants is a longstanding challenge to provide an accurate genetic diagnosis and personalized treatments. In recent years, accessible methodologies have been developed to assess LDLr activity in vitro, providing experimental reproducibility between laboratories all over the world that ensures rigorous analysis of all functional studies. In this review we present a broad spectrum of functionally characterized missense LDLr variants identified in patients with FH, which is mandatory for a definite diagnosis of FH.This work was supported by ELKARTEK 2016 and and the Basque Government (Grupos Consolidados IT849-13). A.B.-V. and S.J. were supported by a grant PIF (2014-2015) and (2018-2021), Gobierno Vasco respectively

    Pathophysiology of Type 2 Diabetes Mellitus

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    Type 2 Diabetes Mellitus (T2DM), one of the most common metabolic disorders, is caused by a combination of two primary factors: defective insulin secretion by pancreatic ő≤-cells and the inability of insulin-sensitive tissues to respond appropriately to insulin. Because insulin release and activity are essential processes for glucose homeostasis, the molecular mechanisms involved in the synthesis and release of insulin, as well as in its detection are tightly regulated. Defects in any of the mechanisms involved in these processes can lead to a metabolic imbalance responsible for the development of the disease. This review analyzes the key aspects of T2DM, as well as the molecular mechanisms and pathways implicated in insulin metabolism leading to T2DM and insulin resistance. For that purpose, we summarize the data gathered up until now, focusing especially on insulin synthesis, insulin release, insulin sensing and on the downstream effects on individual insulin-sensitive organs. The review also covers the pathological conditions perpetuating T2DM such as nutritional factors, physical activity, gut dysbiosis and metabolic memory. Additionally, because T2DM is associated with accelerated atherosclerosis development, we review here some of the molecular mechanisms that link T2DM and insulin resistance (IR) as well as cardiovascular risk as one of the most important complications in T2DM.This work was supported by the Basque Government (Grupos Consolidados IT-1264-19). U.G-G. was supported by Fundaci√≥n Biof√≠sica Bizkaia. A.B.-V. was supported by Programa de especializaci.n de Personal Investigador Doctor en la UPV/EHU (2019) 2019‚Äď2020. S.J. and A.L-S. were supported by a grant PIF (2017‚Äď2018) and (2019‚Äď2020), Gobierno Vasco, respectively. A.L.-S. was partially supported by Fundaci√≥n Biof√≠sica Bizkaia

    Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights

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    Statins are the gold-standard treatment for the prevention of primary and secondary cardiovascular disease, which is the leading cause of mortality worldwide. Despite the safety and relative tolerability of statins, observational studies, clinical trials and meta-analyses indicate an increased risk of developing new-onset type 2 diabetes mellitus (T2DM) after long-term statin treatment. It has been shown that statins can impair insulin sensitivity and secretion by pancreatic ő≤-cells and increase insulin resistance in peripheral tissues. The mechanisms involved in these processes include, among others, impaired Ca2+ signaling in pancreatic ő≤-cells, down-regulation of GLUT-4 in adipocytes and compromised insulin signaling. In addition, it has also been described that statins‚Äô impact on epigenetics may also contribute to statin-induced T2DM via differential expression of microRNAs. This review focuses on the evidence and mechanisms by which statin therapy is associated with the development of T2DM. This review describes the multifactorial combination of effects that most likely contributes to the diabetogenic effects of statins. Clinically, these findings should encourage clinicians to consider diabetes monitoring in patients receiving statin therapy in order to ensure early diagnosis and appropriate management.This work was supported by the Basque Government (Grupos Consolidados IT-1264-19). U.G.-G. was supported by Fundaci√≥n Biof√≠sica Bizkaia. A.B.-V. was supported by Programa de especializaci√≥n de Personal Investigador Doctor en la UPV/EHU (2019) 2019‚Äď2020. S.J. and A.L.-S. were supported by a grant PIF (2017‚Äď2018) and (2019‚Äď2020), Gobierno Vasco, respectively. A.L.-S. was partially supported by Fundaci√≥n Biof√≠sica Bizkaia

    Pathophysiology of Atherosclerosis

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    Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.This work was supported by the Basque Government (Grupos Consolidados IT-1264-19). A.B.-V. was supported by Programa de especializaci√≥n de Personal Investigador Doctor en la UPV/EHU (2019) 2019/2020; U.G-G. was supported by Margarita Salas Grant; and S.J. and A.L-S were supported by a grant PIF (2017‚Äď2018) and PIF (2019‚Äď2020) Gobierno Vasco, respectively

    Cholesterol Efflux Efficiency of Reconstituted HDL Is Affected by Nanoparticle Lipid Composition

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    Cardiovascular disease (CVD), the leading cause of mortality worldwide is primarily caused by atherosclerosis, which is promoted by the accumulation of low-density lipoproteins into the intima of large arteries. Multiple nanoparticles mimicking natural HDL (rHDL) have been designed to remove cholesterol excess in CVD therapy. The goal of this investigation was to assess the cholesterol efflux efficiency of rHDLs with different lipid compositions, mimicking different maturation stages of high-density lipoproteins (HDLs) occurring in vivo. Methods: the cholesterol efflux activity of soybean PC (Soy-PC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), DPPC:Chol:1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (LysoPC) and DPPC:18:2 cholesteryl ester (CE):LysoPC rHDLs was determined in several cell models to investigate the contribution of lipid composition to the effectiveness of cholesterol removal. Results: DPPC rHDLs are the most efficient particles, inducing cholesterol efflux in all cellular models and in all conditions the effect was potentiated when the ABCA1 transporter was upregulated. Conclusions: DPPC rHDLs, which resemble nascent HDL, are the most effective particles in inducing cholesterol efflux due to the higher physical binding affinity of cholesterol to the saturated long-chain-length phospholipids and the favored cholesterol transfer from a highly positively curved bilayer, to an accepting planar bilayer such as DPPC rHDLs. The physicochemical characteristics of rHDLs should be taken into consideration to design more efficient nanoparticles to promote cholesterol efflux.This work was supported by the Basque Government (Grupos Consolidados IT-1264-19). U.G.-G. was supported by Fundaci√≥n Biof√≠sica Bizkaia. A.B.-V. was supported by Programa de especializaci√≥n de Personal Investigador Doctor en la UPV/EHU (2019) 2019‚Äď2020. S.J.-B. and A.L.-S. were supported by a grant PIF (2017‚Äď2018) and (2019‚Äď2020), Gobierno Vasco, respectively. A.L.-S. was partially supported by Fundaci√≥n Biof√≠sica Bizkaia

    Functional Characterization of p.(Arg160Gln) PCSK9 Variant Accidentally Found in a Hypercholesterolemic Subject

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    Familial hypercholesterolaemia (FH) is an autosomal dominant dyslipidaemia, characterised by elevated LDL cholesterol (LDL-C) levels in the blood. Three main genes are involved in FH diagnosis: LDL receptor (LDLr), Apolipoprotein B (APOB) and Protein convertase subtilisin/kexin type 9 (PCSK9) with genetic mutations that led to reduced plasma LDL-C clearance. To date, several PCSK9 gain-of-function (GOF) variants causing FH have been described based on their increased ability to degrade LDLr. On the other hand, mutations that reduce the activity of PCSK9 on LDLr degradation have been described as loss-of-function (LOF) variants. It is therefore important to functionally characterise PCSK9 variants in order to support the genetic diagnosis of FH. The aim of this work is to functionally characterise the p.(Arg160Gln) PCSK9 variant found in a subject suspected to have FH. Different techniques have been combined to determine efficiency of the autocatalytic cleavage, protein expression, effect of the variant on LDLr activity and affinity of the PCSK9 variant for the LDLr. Expression and processing of the p.(Arg160Gln) variant had a result similar to that of WT PCSK9. The effect of p.(Arg160Gln) PCSK9 on LDLr activity is lower than WT PCSK9, with higher values of LDL internalisation (13%) and p.(Arg160Gln) PCSK9 affinity for the LDLr is lower than WT, EC50 8.6 ¬Ī 0.8 and 25.9 ¬Ī 0.7, respectively. The p.(Arg160Gln) PCSK9 variant is a LOF PCSK9 whose loss of activity is caused by a displacement of the PCSK9 P‚Äô helix, which reduces the stability of the LDLr-PCSK9 complex.This research was funded by Grupos Consolidados Gobierno Vasco 2021, grant number IT1720-22. A.L.-S. was supported by a grant PIF (2019‚Äď2020), Gobierno Vasco and partially supported by Fundaci√≥n Biof√≠sica Bizkaia. S.J-B. was supported by a Margarita Salas Grant 2022 from the University of the Basque Country

    Age, Origin and Functional Study of the Prevalent LDLR Mutation Causing Familial Hypercholesterolaemia in Gran Canaria

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    The p.(Tyr400_Phe402del) mutation in the LDL receptor (LDLR) gene is the most frequent cause of familial hypercholesterolaemia (FH) in Gran Canaria. The aim of this study was to determine the age and origin of this prevalent founder mutation and to explore its functional consequences. For this purpose, we obtained the haplotypic information of 14 microsatellite loci surrounding the mutation in one homozygous individual and 11 unrelated heterozygous family trios. Eight different mutation carrier haplotypes were identified, which were estimated to originate from a common ancestral haplotype 387 (110‚Äď1572) years ago. This estimation suggests that this mutation happened after the Spanish colonisation of the Canary Islands, which took place during the fifteenth century. Comprehensive functional studies of this mutation showed that the expressed LDL receptor was retained in the endoplasmic reticulum, preventing its migration to the cell surface, thus allowing us to classify this LDLR mutation as a class 2a, defective, pathogenic variant.This work was supported by grants from the Instituto de Salud Carlos III (ISCIII): PI20/00846, INT21/00032 (RMS), CM19/00116 (AMGL) with the participation of the European Union through European Regional Development Funds (‚ÄúA way to make Europe‚ÄĚ), the Fundaci√≥n Canaria del Instituto de Investigaciones Sanitarias de Canarias (FCIISC): PIFIISC20/16 and the Fundaci√≥n Mapfre Guanarteme (Beca Investigaci√≥n 2020). NMS was supported by a Mar√≠a Zambrano Fellowship funded by the Spanish Ministry of Universities within the ‚ÄúNext Generation EU‚ÄĚ scheme

    Replacement of Cysteine at Position 46 in the First Cysteine-Rich Repeat of the LDL Receptor

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    Background and aims Pathogenic mutations in the Low Density Lipoprotein Receptor gene (LDLR) cause Familial Hypercholesterolemia (FH), one of the most common genetic disorders with a prevalence as high as 1 in 200 in some populations. FH is an autosomal dominant disorder of lipoprotein metabolism characterized by high blood cholesterol levels, deposits of cholesterol in peripheral tissues such as tendon xanthomas and accelerated atherosclerosis. To date, 2500 LDLRvariants have been identified in the LDLR gene; however, only a minority of them have been experimentally characterized and proven to be pathogenic. Here we investigated the role of Cys46 located in the first repeat of the LDL receptor binding domain in recognition of apolipoproteins. Methods Activity of the p.(Cys46Gly) LDLR variant was assessed by immunoblotting and flow cytometry in CHO-/d/A7 expressing the receptor variant. Affinity of p.(Cys46Gly) for LDL and VLDL was determined by solid-phase immunoassays and in silico analysis was used to predict mutation effects. Results and conclusion Functional characterization of p.(Cys46Gly) LDLRvariant showed impaired LDL and VLDL binding and uptake activity. Consistent with this, solid-phase immunoassays showed the p. (Cys46Gly) LDLR variant has decreased binding affinity for apolipoproteins. These results indicate the important role of Cys46 in LDL receptor activity and highlight the role of LR1 in LDLr activity modulation. This study reinforces the significance of in vitro functional characterization of LDL receptor activity in developing an accurate approach to FH genetic diagnosis. This is of particular importance because it enables clinicians to tailor personalized treatments for patients' mutation profile.Progenika Biopharma SA, is an Spanish biotech company founded in 2000 with headquarters in Derio, Bizkaia (SPAIN). Progenika Biopharma SA did not play a role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript and only provided financial support in the form of authors' salaries to M.S. and L.P. This work was supported by Gobernio Vasco, ELKARTEK BIOGUNE 2015 (Codigo KK-2015/0000089) and Basque Government (Grupos Consolidados IT849-13). A. B-V. was supported by a grant (PIF 2014/2015) Eusko Jaurlaritza and S.J. was supported by grant (PIF 2018/2019) Eusko Jaurlaritza. The funders did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Design and Validation of a Process Based on Cationic Niosomes for Gene Delivery into Novel Urine-Derived Mesenchymal Stem Cells

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    Background: Mesenchymal stem cells (MSCs) are stem cells present in adult tissues. They can be cultured, have great growth capacity, and can differentiate into several cell types. The isolation of urine-derived mesenchymal stem cells (hUSCs) was recently described. hUSCs present additional benefits in the fact that they can be easily obtained noninvasively. Regarding gene delivery, nonviral vectors based on cationic niosomes have been used and are more stable and have lower immunogenicity than viral vectors. However, their transfection efficiency is low and in need of improvement. Methods: We isolated hUSCs from urine, and the cell culture was tested and characterized. Different cationic niosomes were elaborated using reverse-phase evaporation, and they were physicochemically characterized. Then, they were screened into hUSCs for transfection efficiency, and their internalization was evaluated. Results: GPxT-CQ at a lipid/DNA ratio of 5:1 (w/w) had the best transfection efficiency. Intracellular localization studies confirmed that nioplexes entered mainly via caveolae-mediated endocytosis. Conclusions: In conclusion, we established a protocol for hUSC isolation and their transfection with cationic niosomes, which could have relevant clinical applications such as in gene therapy. This methodology could also be used for creating cellular models for studying and validating pathogenic genetic variants, and even for performing functional studies. Our study increases knowledge about the internalization of tested cationic niosomes in these previously unexplored cellsThis research was funded by a grant from the EITB Maratoia to G.P.d.N., C.M., and J.L.P. (BIO16/ER/005), from the University of the Basque Country UPV/EHU to Y.V. (PIF17/29), and from the Basque Government to S.J.-B. (PRE_2017-1-0365)
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