Estudio de los procesos celulares implicados en la infección por VIH-1: HDAC6 como nuevo factor de restricción.

En la actualidad 37 millones de personas viven infectadas con el Virus de la Inmunodeficiencia Humana tipo 1 (VIH-1), siendo éste el causante de la muerte de 1,2 millones de personas al año. Esto significa que, a pesar de los avances en el tratamiento y la prevención, el sida continúa siendo una enfermedad con un gran impacto en la población a nivel mundial. El descubrimiento de los factores de restricción anti-retrovirales, que presentes en nuestras células, combaten la presencia del virus, además de la caracterización de las diversas proteínas del virus encargadas de contrarrestar la acción de estos factores, ha abierto un área de conocimiento de gran interés. El tándem más estudiado en este sentido es el conformado por APOBEC3G y Vif. La proteína viral Vif logra, mediante la inducción de poli-ubiquitinación, promover la degradación proteasómica de APOBEC3G, un factor de restricción que afecta gravemente a la capacidad infectiva del VIH. Además, la proteína estructural del VIH-1, Pr55-Gag, también hace uso de la ubiquitinación para llevar a cabo su función. Pr55-Gag requiere de ser ubiquitinada para lograr anclarse eficientemente a la membrana plasmática, agregarse en la zona de salida del virus y que se produzca la maduración correcta de la partícula viral. En este contexto, donde la ubiquitinación es un proceso relevante en el ciclo viral, este trabajo de tesis doctoral se centra en el estudio de la proteína celular HDAC6. HDAC6 presenta una gran capacidad de unir Ubiquitina y juega un papel esencial en los procesos de degradación de agregados ubiquitinados en la célula. En este trabajo describimos a HDAC6 como un factor de protección de APOBEC3G mediante dos acciones. Por un lado, evita su degradación protegiéndolo de manera competitiva frente a Vif, y por otro, provoca la degradación de Vif vía autofagia. También describimos que HDAC6 reconoce las proteínas Pr55-Gag ubiquitinadas en su región C terminal, provocando su degradación también vía autofagia, evitando una producción eficiente de partículas virales. En este escenario, y frente a la necesidad de continuar con la búsqueda de nuevos factores de lucha contra esta enfermedad, además de ampliar los conocimientos existentes sobre el VIH y los mecanismos existentes de la célula de lucha contra el virus, nosotros proponemos HDAC6 como un excelente candidato a estudio como un nuevo factor de restricción anti-VIH

Key molecules of triglycerides pathway metabolism are disturbed in patients with systemic lupus erythematosus

Background: Elevated triglycerides or triglyceride-rich lipoproteins are an additional cause of cardiovascular (CV) disease. Given that patients with systemic lupus erythematosus (SLE) have a high prevalence of premature CV disease and show an altered lipid profile, our objective was to study whether three molecules that play a central role in the triglyceride metabolism: apolipoprotein C-III (ApoC3), angiopoietin-like protein 4 (ANGPLT4), and lipoprotein lipase (LPL) differ between SLE patients and controls, and how they are related to disease characteristics, including disease damage. Methods: Cross-sectional study that included 347 women, 185 of them diagnosed with SLE and 162 age-matched controls. ANGPTL4, ApoC3 and LPL, and standard lipid profiles were analyzed in SLE patients and controls. A multivariable analysis was performed to assess whether ANGPTL4, ApoC3 and LPL molecules differ between patients and controls and to study their relationship with SLE disease damage. Results: After fully multivariable analysis that included classic CV risk factors, and the modifications that the disease itself produces over the lipid profile, it was found that ApoC3 was significantly lower (beta coef. -1.2 [95%CI -1.6- -0.8) mg/dl, <0.001), and ANGPTL4 (beta coef. 63 [95%CI 35-90] ng/ml, <0.001) and LPL (beta coef. 79 [95%CI 30-128] ng/ml, p=0.002) significantly higher in patients with SLE compared to controls. Disease damage score was significantly and independently associated with higher serum levels of LPL (beta coef. 23 [95%CI 10-35] ng/ml, p=0.001). Mediation analysis suggested that the relationship between disease damage and LPL was direct and not mediated by ApoC3 or ANGPLT4. Conclusion: The ApoC3, ANGPLT4 and LPL axis is disrupted in patients with SLE. Disease damage explains this disturbance.Funding: This work was supported by a grant to IF-A from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Cientı́fica y Técnica y de Innovación 2013-2016 and by Fondo Europeo de Desarrollo Regional - FEDER - (Fondo de Investigaciones Sanitarias, PI17/00083)

Proprotein convertase subtilisin/kexin type 9 is related to disease activity and damage in patients with systemic erythematosus lupus

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease that regulates cholesterol metabolism through low-density lipoprotein receptor degradation and that has been linked to cardiovascular (CV) disease. The purpose of the present study was to examine whether PCSK9 levels are disrupted compared with controls in patients with systemic lupus erythematosus (SLE). We additionally sought to establish whether PCSK9 is related to both the abnormalities in the lipid profile and to the disease activity or damage of patients with SLE. Methods: We performed a cross-sectional study that encompassed 366 individuals: 195 SLE patients and 171 age-, sex-, and statin intake-matched controls. PCSK9, lipoproteins serum concentrations, and lipid profiles were assessed in patients and controls. A multivariable analysis, adjusted for standard CV risk factors, was performed to evaluate the role of PCSK9 in SLE-related dyslipidemia. Results: Most lipid related-molecules were decreased in patients with SLE compared with controls. This downregulation included PCSK9, with PCSK9 levels being lower in patients than controls in the full multivariable analysis, including the modifications in lipid profiles that the disease itself produces {beta coefficient ?73 [95% confidence interval (CI) ?91 to ?54] ng/ml, p???0.001}. Both SLICC and SLEDAI scores were independently and positively related to PCSK9. Patients currently on hydroxychloroquine exhibited decreased levels of PCSK9 compared with those that were not taking hydroxychloroquine [beta coefficient ?30 (95% CI ?54 to ?6) ng/ml, p?=?0.015]. Conclusion: PCSK9 is downregulated in SLE compared with controls, but SLE patients with higher disease activity and damage exhibited higher PSCK9 serum levels.The authors disclosed receipt of the following financial support for the research, authorship, and/ or publication of this article: this work was supported by a grant to IF-A from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016 and by Fondo Europeo de Desarrollo Regional - FEDER - (Fondo de Investigaciones Sanitarias, FIS PI14/00394, PI17/00083). The research of MAG-G is supported by the Instituto de Salud Carlos III (ISCIII) (Fondo de Investigación Sanitaria grants PI06/0024, PI09/00748, PI12/00060, PI15/00525, PI18/00043) and the ISCIII RETICS program (RD12/0009 and RD16/0012)

Apolipoprotein C-III is linked to the insulin resistance and beta-cell dysfunction that are present in rheumatoid arthritis

Background: Insulin resistance and beta-cell dysfunction are manifestations of rheumatoid arthritis (RA). Apolipoprotein C-III (ApoC3) has been associated with such insulin resistance and beta-cell dysfunction in the general population. Our purpose was to study whether ApoC3 is also related to the insulin resistance and beta-cell dysfunction that are present in patients with RA. Methods: Three hundred thirty-eight non-diabetic patients with RA who had a glycemia lower than 110 mg/dl were recruited. Insulin, C-peptide, and ApoC3 were assessed. Insulin resistance and beta-cell function were calculated using the Homeostasis Model Assessment (HOMA2) indices. A multivariable regression analysis was performed to study the relationship of ApoC3 with those molecules and indices adjusting for classic factors associated with insulin resistance that included glucocorticoids. Results: ApoC3 was related to significant higher levels of circulating insulin (beta coef. 0.37 [95%CI 0.01–0.73] μU/ml, p = 0.044) and C-peptide (beta coef. 0.13 [95%CI 0.05–0.22] ng/ml, p = 0.003), and higher insulin resistance —HOMA2- IR— (beta coef. 0.05 [95%CI 0.00–0.09], p = 0.041) and beta-cell dysfunction —HOMA2-%B— (beta coef. 2.94 [95%CI0.07–5.80], p = 0.044) indices. This was found after a fully multivariable analysis that included, among others, prednisone intake and the classic factors associated with carbohydrate metabolism such as triglycerides, waist circumference, and obesity. Conclusion: ApoC3, insulin resistance, and beta-cell dysfunction are independently associated in patients RA.This work was supported by a grant to I.F-A. from the Spanish Ministry of Health, Subdireccion General de Evaluacion y Fomento de la Investigacion, Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion 2013–2016 and by Fondo Europeo de Desarrollo Regional—FEDER—(Fondo de Investigaciones Sanitarias, PI17/00083

Gelsolin activity controls efficient early HIV-1 infection

HIV-1 entry into target lymphocytes requires the activity of actin adaptors that stabilize and reorganize cortical F-actin, like moesin and filamin-A. These alterations are necessary for the redistribution of CD4-CXCR4/CCR5 to one pole of the cell, a process that increases the probability of HIV-1 Envelope (Env)-CD4/co-receptor interactions and that generates the tension at the plasma membrane necessary to potentiate fusion pore formation, thereby favouring early HIV-1 infection. However, it remains unclear whether the dynamic processing of F-actin and the amount of cortical actin available during the initial virus-cell contact are required to such events

The angiopoietin-like protein 4, apolipoprotein C3, and lipoprotein lipase axis is disrupted in patients with rheumatoid arthritis

Background: Modulators of triglyceride metabolism include lipoprotein lipase (LPL), angiopoietin-like protein 4 (ANGPTL4), and apolipoprotein C-3 (ApoC3). There is evidence on the influence of this triangle of molecules on an increased risk of atherosclerotic cardiovascular disease (CV) in the general population. Patients with rheumatoid arthritis (RA) present changes in lipid profiles and accelerated CV disease. In the present study, we set out to study whether the ANGPTL4, ApoC3, and LPL axis differs in subjects with RA compared to controls. In a further step, we investigated the relationship of this axis with subclinical atherosclerosis in patients with RA. Methods: Cross-sectional study that included 569 individuals, 323 patients with RA and 246 age-matched controls. ANGPTL4, ApoC3 and LPL, and standard lipid profiles were analyzed in patients and controls. Carotid intima-media thickness (cIMT) and carotid plaques were assessed in RA patients. A multivariable analysis was performed to assess whether the ANGPTL4, ApoC3, and LPL axis was altered in RA and to study its relationship with RA dyslipidemia and subclinical carotid atherosclerosis. Results: Most lipid profile molecules did not differ between patients and controls. Despite this, and after fully multivariable analysis including CV risk factors, use of statins, and changes in the lipid profile caused by the disease itself, patients with RA showed higher serum levels of ANGPTL4 (beta coef. 295 [95% CI 213-376] ng/ml, p<0.001) and ApoC3 (beta coef. 2.9 [95% CI 1.7-4.0] mg/dl, p<0.001), but lower circulating LPL (beta coef. -174 [95% CI -213 to - 135] ng/ml, p<0.001). ANGPTL4 serum levels were positively and independently associated with a higher cIMT in patients with RA after fully multivariable adjustment. Conclusion: The axis consisting in ANGPTL4, ApoC3, and LPL is disrupted in patients with RA. ANGPTL4 serum levels are positively and independently associated with a higher cIMT in RA patients.Funding: This work was supported by a grant to IFA from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016 and by Fondo Europeo de Desarrollo Regional - FEDER - (Fondo de Investigaciones Sanitarias, PI17/00083)

The Number of Traditional Cardiovascular Risk Factors Is Independently Correlated with Disease Activity in Patients with Psoriatic Arthritis

Background and objectives: Psoriatic arthritis (PsA) is associated with several comorbidities, including among others an increased risk of cardiovascular (CV) disease, atherosclerosis, metabolic syndrome, hypertension dyslipidemia, and diabetes. The purpose of the present study was to determine how the number of CV risk factors correlates with disease related data such as disease activity. Materials and Methods: Cross-sectional study that encompassed 305 patients who fulfilled the CASPAR criteria for PsA were assessed for lipid profile, disease activity measurements, and the presence of six traditional CV risk factors (diabetes mellitus, dyslipidemia, hypertension, obesity, chronic kidney disease, and smoking status). A multivariable regression analysis, adjusted for age, sex, and disease duration, was performed to evaluate if the number of classic CV risk factors was independently related with specific features of the disease, including disease activity. Results: Disease duration was found to be higher, after adjustment for age and sex, in patients with 1 or 2, and 3 or higher CV factors, compared to those patients without CV risk factors. Similarly, DAPSA (Disease Activity in PSoriatic Arthritis score) was found to be independently upregulated in patients with a higher number of CV risk factors. In this sense, as DAPSA score increases the odds ratio (OR) of having 1 or 2 (OR 1.12 (95% confidence interval (CI) 1.03?1.21), p = 0.010), and 3 or higher (OR 1.15 (95% CI 1.04?1.26), p = 0.004) CV factors was significantly higher compared to no CV risk factors category. This was independently found after adjustment for age, sex, and disease duration. Conclusions: PsA patients with a higher number of CV risk factors exhibit an upregulated disease activity compared to those without them. This is independent of disease duration and other demographics factorsThis research was funded by the Instituto de Salud Carlos III (ISCIII) (Fondo de Investigación Sanitaria grants PI06/0024, PI09/00748, PI12/00060, PI15/00525, PI18/00043) and the ISCIII RETICS programs (RD12/0009 and RD16/0012)

Viral Characteristics Associated with the Clinical Nonprogressor Phenotype Are Inherited by Viruses from a Cluster of HIV-1 Elite Controllers

A small group of HIV-1-infected individuals, called long-term nonprogressors (LTNPs), and in particular a subgroup of LTNPs, elite controllers (LTNP-ECs), display permanent control of viral replication and lack of clinical progression. This control is the result of a complex interaction of host, immune, and viral factors. We identified, by phylogenetic analysis, a cluster of LTNP-ECs infected with very similar low-replication HIV-1 viruses, suggesting the contribution of common viral features to the clinical LTNP-EC phenotype. HIV-1 envelope (Env) glycoprotein mediates signaling and promotes HIV-1 fusion, entry, and infection, being a key factor of viral fitness in vitro, cytopathicity, and infection progression in vivo Therefore, we isolated full-length env genes from viruses of these patients and from chronically infected control individuals. Functional characterization of the initial events of the viral infection showed that Envs from the LTNP-ECs were ineffective in the binding to CD4 and in the key triggering of actin/tubulin-cytoskeleton modifications compared to Envs from chronic patients. The viral properties of the cluster viruses result in a defective viral fusion, entry, and infection, and these properties were inherited by every virus of the cluster. Therefore, inefficient HIV-1 Env functions and signaling defects may contribute to the low viral replication capacity and transmissibility of the cluster viruses, suggesting a direct role in the LTNP-EC phenotype of these individuals. These results highlight the important role of viral characteristics in the LTNP-EC clinical phenotype. These Env viral properties were common to all the cluster viruses and thus support the heritability of the viral characteristics.IMPORTANCE HIV-1 long-term nonprogressor elite controller patients, due to their permanent control of viral replication, have been the object of numerous studies to identify the factors responsible for this clinical phenotype. In this work, we analyzed the viral characteristics of the envelopes of viruses from a phylogenetic cluster of LTNP-EC patients. These envelopes showed ineffective binding to CD4 and the subsequent signaling activity to modify actin/tubulin cytoskeletons, which result in low fusion and deficient entry and infection capacities. These Env viral characteristics could explain the nonprogressor clinical phenotype of these patients. In addition, these inefficient env viral properties were present in all viruses of the cluster, supporting the heritability of the viral phenotype.A.V.-F.’s lab is supported by the European regional development fund (ERDF), SAF2015-64118-R (Ministerio de Economia y Competitividad, MINECO, Spain) Fundación CajaCanarias BIO29, UNLL10-3E-783 (ERDF and Fundación CajaCanarias), and by the Spanish AIDS Research Network RIS-RETIC grants RD16/0025/0011 and RD12/0017/0034 and cofunded by ISCIII and ERDF (RIS-RETIC) grants. R.C.-R., M.-S.V., L.A.-R., S.M.-H., and D.M.-A. are funded by RD16/0025/0011, RD12/0017/0034-(RIS-RETIC), SAF2011-24671-FPI, TESIS2015-010038- and TESIS2017010116-Programa Predoctoral de Formación del Personal Investigador, Agencia Canaria de Investigación, Innovación y Sociedad de la Información de la Consejería de Economía, Industria, Comercio y Conocimiento y por el Fondo Social Europeo (FSE) Programa Operativo Integrado de Canarias 2014-2020, Eje 3 Tema Prioritario 74 (85%), and European Social Fund and Fundación CajaCanarias BIO29-fellowships. Work in J.B.’s lab is supported by grants PI14/01307 and PI17/01518 from the Fondo de Investigaciones Sanitarias (FIS, Instituto de Salud Carlos III, ISCIII) and RIS-RETIC grants RD12/0017/0002 and RD16/0025/0041, cofunded by ISCIII and FEDER (EU). J.B. is a researcher from Fundació Institut de Recerca en Ciències de la Salut Germans Trias i Pujol supported by the Health Department of the Catalan Government (Generalitat de Catalunya). IrsiCaixa and IGTP are part of CERCA Programme/Generalitat de Catalunya. Work in C.L.-G.’s lab was supported by grants SAF (2010-17226) and (2016-77894-R) from MINECO (Spain) and FIS (PI 13/02269, ISCIII) and in part by the RIS-RETIC grants RD06/006/0036 and RD12/0017/0028 funded by the ISC III-FEDER. M.P. has support from RIS-RETIC contract RD12/0017/0036. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Work in P.L.’s lab is supported by Bijzonder Onderzoeksfonds KU Leuven (BOF)' no. OT/14/115 and the Fonds voor Wetenschappelijk Onderzoek Vlaanderen (FWO) (G066215N).S