Nuestros investigadores

Elena Alonso Iglesias

Publicaciones científicas más recientes (desde 2010)

Autores: Razquin Burillo, Cristina; Ortega Cubero, Sara; Rojo-Bustamante, E.; et al.
ISSN 0197-4580  Vol. 66  2018  págs. 177.e7 - 177.e10
The main genetic risk factors for progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are located at chromosome 17q21.31. The identification of risk H1 subhaplotypes suggests that disease-specific variants can be identified by resequencing the 17q21.31 region (1.4 Mb) in carriers of risk H1 subhaplotypes. We hypothesized that PSP/CBD H1 subhaplotype carriers could have undergone a mutational event absent among unaffected carriers leading to the disease risk. We performed this strategy in definite PSP subjects, definite CBD subjects, and healthy controls and tried to replicate the findings in a larger PSP/CBD case-control series. In the resequencing process, 40 candidate variants were identified, but an association between PSP and rs76970862 was replicated only using an unadjusted model. Gene expression association analysis of this variant suggested no potential functional effect. Although our results failed to identify disease-associated variants, it is still possible that the risk of PSP/CBD at chromosome 17 is driven by rare variants, even in PSP/CBD H1 cases or variants located outside the capture regions. (C) 2018 Elsevier Inc. All rights reserved.
Autores: Fernández Robredo, Patricia; Sáenz de Viteri Vázquez, Manuel; Recalde Maestre, Sergio; et al.
ISSN 0146-0404  Vol. 57  Nº 12  2016  págs. 3363
Purpose : To evaluate intracellular accumulation and the effect of bevacizumab, ranibizumab and aflibercept on cellular migration and permeability in a human retinal pigmented epithelium (RPE) cell line. Methods : Experiments were performed on ARPE-19 cells and anti-VEGF drugs were diluted to a concentration equivalent to their clinical doses. Anti-VEGFs were labeled with Alexa 488 fluorochrome to detect intracellular accumulation by flow cytometry at 1 hour, 1 day and five days. Further, transepithelial electrical resistance (TEER) was measured in transwells at 2, 4, 6, 12 and 24 hours to assess the effect of anti-VEGFs on RPE permeability. Moreover, TEER was also measured at the same time points in the presence of different doses of H2O2 to replicate the oxidative environment observed in Age-related Macular Degeneration (AMD). Wound healing was assessed to determine the effect of the drugs on cellular migration during 72 hours to measured cell covered area by ImageJ software. Results : The three studied drugs were observed to accumulate inside the cells and they were still detectable five days after being added (p<0.001). A dose-dependent increased in cell permeability was observed in cells treated with H2O2 (p<0.05) that was reverted from the time point of 12 hours and became non-significant. Anti-VEGF drugs did not affect the permeability along time and they were able to reduce the effect of H2O2. Cells treated with anti-VEGF drugs at the beginning of the experiment showed a significant decrease in the damage produced by H2O2 at 4, 6 and 12 hours (p<0.05) with no significant difference between the treatments. On the contrary, when anti-VEGF treatment was used 6 hours after the beginning of the experiment, none of the 3 drugs decreased the deleterious effect of H2O2 in TEER. Anti-VEGF drugs did not affect cellular migration. Conclusions : Intracellular accumulation of bevacizumab, ranibizumab and aflibercept does not seem to be toxic or affect cell permeability and migration. Moreover, our study suggests that anti-VEGFs have a positive effect on the barrier function of the RPE.
Autores: Reiter, N.; Sáenz de Viteri Vázquez, Manuel; Recalde Maestre, Sergio; et al.
ISSN 0146-0404  Vol. 56  Nº 7  2015  págs. 2016
Purpose: Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. Controversy exists regarding the safety of agents that inhibit vascular endothelial growth factor (VEGF). In this study we performed different assays to compare in vitro cytotoxicity of bevacizumab (B), ranibizumab (R), and aflibercept (A) at clinical doses on retinal pigment epithelia (RPE) cell line (ARPE19). Methods: Cellular toxicity was assessed through MTT cell viability and BrdU proliferation assays after single or repeated doses of the anti-VEGF drugs. Immunofluorescence (IF) for zonula ocludens (ZO-1) was performed. Intracellular accumulation was determined by IF (antihuman Cy3) one and five days after treatment with B, R and A. IF was also used to determine the activity of caspase-3 after single or repeated doses of B, R and A. The effect of anti-VEGF agents on cell phagocytosis of fluorescent latex beads was also assessed. Finally, RPE permeability 24, 48 and 72 hours after anti-VEGF treatments was studied using a FITC permeability assay on transwell inserts. Statistical analysis was performed (SPSS 20). Results: There were no statistically significant differences in cell viability or cell proliferation after single or repeated doses of B, R and A. The tight junction labeled with ZO-1 was not altered with treatments. On the contrary, intracellular accumulation of R was significantly lower compared to the other anti-VEGF agents up to 5 days after initial treatment. Phagocytosis was significantly lower in cells treated with R and A (34% and 28.8%, p<0.001) compared to the control group, but not statistically significant in cells treated with B (75%, p=0.104). We found no significant differences in caspase-3 activity between the 3 drugs neither 24 hours nor one week after treatment. The anti-VEGF agents did not affect FITC permeability when compared to the control group at any time points. Conclusions: Our results suggest that ranibizumab is the anti-VEGF agent that accumulates intracellularly to a lesser extent. However this finding does not affect in vitro cell viability and proliferation in the short time. Furthermore, we did not find a significant effect in cell death, cellular permeability or phagocytosis after single or repeated doses of the treatments. These results imply that anti-VEGF agents at clinical doses are safe in ARPE19 cells.
Autores: Ortega Cubero, Sara; Lorenzo-Betancor, O.; Lorenzo Ramos, María Elena; et al.
ISSN 0197-4580  Vol. 34  Nº 10  2013  págs. 2441.e9 - 2441.e11
FUS/TLS (denoting fused in sarcoma/translocated in liposarcoma [MIM 137070]) codifies an RNA binding protein. Mutations in this gene cause amyotrophic lateral sclerosis (ALS; MIM 608030). Essential tremor (ET [MIM 190300]) is the most frequent movement disorder. Despite its strong familiar aggregation, recently a whole exome sequencing study has identified FUS mutations as a cause of familial ET. To determine whether mutations in FUS are also common in other populations, we sequenced FUS gene in 178 unrelated Spanish subjects with ET. We detected only an intronic single-pair nucleotide deletion (c.1293-37delC), which was predicted to affect mRNA splicing. However, leukocyte mRNA analysis showed no changes in FUS expression. In conclusion, coding or splicing FUS mutations are not a frequent cause of ET in the Spanish population.
Autores: Cervantes Ibáñez, Sebastián; Samaranch Gusi, Lluís; Vidal Taboada, José Manuel; et al.
Revista: Neurobiology of Aging
ISSN 0197-4580  Vol. 32  Nº 11  2011  págs.  2107. e7- 17
We report the fine mapping/sequencing results of promoter and regulatory regions of APOE cluster genes (APOE, APOC1, APOC4, APOC2, and TOMM40) in Alzheimer's disease (AD) risk as well as in the progression from mild cognitive impairment (MCI) to AD. Long-range sequencing in 29 MCI subjects who progressed to dementia revealed 7 novel variants. Two potentially relevant novel variants and 34 single nucleotide polymorphisms (SNPs) were genotyped in a large sample of AD, MCI, and control subjects (n = 1453). Globally, very little association signal was observed in our sample in the absence of APOE ¿4. Rs5158 (APOC4 intron 1) and rs10413089 (3' to APOC2) showed a trend toward an increase in AD risk independently from APOE ¿4 associated risk though it did not survive multiple test correction (uncorrected p = 0.0099 and 0.01, respectively). Interestingly, rs10413089 showed a similar effect in an independent series. The analysis of the discovery sample showed an association of TOMM40 single nucleotide polymorphisms with progression from MCI stage to AD (rs59007384 and rs11556510), as well as with a shorter time to progression from MCI status to AD (rs10119), though these results could not be replicated in independent series. Further studies are needed to investigate the role of APOE cluster variants in AD risk.