Biomedical subjects

Jose Luis Royo

Publications and source records attributed to Jose Luis Royo.

7 recordsLinked to original sources

PubMed2026

APOE-stratified genome-wide association analyses provide insights into the genetic etiology of Alzheimers's disease.

Among the more than 90 identified genetic risk loci for late-onset Alzheimer's disease (AD) and related dementias, the apolipoprotein E (APOE) gene ɛ2/ɛ3/ɛ4 polymorphisms remain the longstanding benchmark for genetic disease risk with a consistently large effect across studies1-10. Despite this massive signal, the exact mechanisms by which ɛ4 increases and ɛ2 decreases dementia risk remain poorly understood. Notably, recent trials of anti-amyloid therapies suggest less efficacy and higher risks of severe side effects in ε4 carriers11-13, hampering the treatment of those with the highest unmet need. To improve our understanding of the genetic architecture of AD in the context of its main genetic driver, we performed genome-wide association studies (GWASs) stratified by ε4 and ε2 carrier status. HP1BP3, SLC50A1, PTPRC, NPAS3, DDHD1, CHST9, SMYD2, PRAMEF1 and GFRA1 emerged as new genomic signals for AD risk, appearing only when stratified by APOE carrier status. DDHD1 appeared especially promising, showing protective effects in ε4 carriers, being identified as an expression quantitative trait locus and being involved in rare neuronal diseases. Such APOE-stratified insights may help understand and overcome side effects, inform clinical trial enrollment strategies, and create the scientific basis for targeted, mechanism-driven therapies in neurodegenerative diseases.

Journal Article↗

PubMed2006

Lack of association between NOS3 Glu298Asp and breast cancer risk: a case-control study.

Nitric oxide (NO) plays a central role in the physiololgy and pathology of diverse tissues. Different studies provide data suggesting that the endothelial cell nitric oxide synthase (NOS3) expression in peritumoral microvessels might be a prognostic indicator in breast cancer patients. However, the putative contribution of common NOS3 germline variants to breast cancer risk remained unknown. A recent work comprising 269 breast cancer patients and 244 controls suggested that NOS3 Glu298Asp polymorphism is associated to breast cancer risk (OR=1.9). We performed an independent analysis of these results in 440 unrelated patients and 321 controls from Spanish population. Although our study was 90% powered to detect ORs >/=1.55, did not find any significant difference in the Glu298Asp allele distribution between cases and controls (P > 0.42). These putative reasons for this result are discussed.

Aspartic Acid↗

PubMed2006

Pyrosequencing protocol requiring a unique biotinylated primer.

BACKGROUND: DNA sequencing has markedly changed the nature of biomedical research. Large-scale sequencing projects have generated several millions of potential polymorphisms widespread in the human genome requiring validation and incorporation into screening panels. As a consequence, high-throughput analysis of these variants in different populations of interest is now the cornerstone of structural genomics. Pyrosequencing is a versatile technique allowing an easy 96-well typing format. However, every polymorphism requires a specific labeled primer to generate a single-stranded DNA fragment containing the region of interest. METHODS: We describe how with an adjusted primer stoichiometry we can standardize the labeling of every amplicon with a single biotinylated universal primer (BM13S). RESULTS: We circumvent the need for specific biotinylated primers for each single-nucleotide polymorphism (SNP) under study. As an example, we assessed this novel protocol by genotyping three SNPs mapping calpain-10, caveolin-1 and CYP19A1. CONCLUSION: The present approach represents an alternative to standard pyrosequencing protocols, since it requires a single biotinylated primer that is suitable for each SNP under study.

Biotinylation↗

PubMed2006

Genetic analysis of CAV1 gene in hypertension and metabolic syndrome.

Recently, we reported that the polymorphism 1132T>C (GenBank: AF519768.1) of the NOS3 gene was associated with susceptibility to metabolic syndrome (MS) in hypertensive patients. This suggests that other genes such as CAV1, whose product (CAV1) regulates eNOS activity, could also be related to this phenotype. In this work we investigated the following: i) whether CAV1 is a quantitative trait locus of clustering of atherothrombotic traits associated with MS; ii) whether CVA1 is associated with hypertension or MS in hypertensive patients; and iii) whether genetic interaction between NOS3 and CAV1 is involved in the susceptibility or protection to hypertension associated with MS. To carry out the study, we genotyped 285 randomly selected individuals and 175 hypertensive patients, all of them < or = 60 years old, with two polymorphisms of the CAV1 gene: the 22285 C>T and the 22375-22375 del AC (GenBank AF125348), and the 1132T>C polymorphism of the NOS3 gene. To perform sample genotyping, we used pyrosequencing and FRET techniques. The 22285 C-22375-22375 del (Cd) haplotype of CAV1 gene was associated with low levels of blood pressure in the general population. Moreover, it was a genetic protection factor against MS in hypertensive patients. In addition, we found no evidence of gene-gene interaction between NOS3 and CAV1 genes with regard to that phenotype.

Case-Control Studies↗

PubMed2006

Genetic analysis of caveolin-1 and eNOS genes in colorectal cancer.

Caveolae are involved in physical compartmentalization between different groups of signaling events. Its main component, CAV1, modulates different pathways in cellular physiology. The emerging evidence pointing to the role of CAV1 in cancer led us to study whether different alleles of this gene are associated with colorectal cancer (CRC). Since one of the most characterized enzymes regulated by CAV1 is eNOS, we decided to include both genes in this study. We analyzed five SNPs in 360 unrelated CRC patients and 550 controls from the general population. Two of these SNPs were located within eNOS and three within the CAV1 gene. Although haplotype distribution was not associated with CRC, haplotype TiA (CAV1) was associated with familiar forms of CRC (p<0.05). This was especially evident in CRC antecedents and nuclear forms of CRC. If both CG (eNOS) and TiA (CAV1) haplotypes were taken together, this association increased in significance. Thus, we propose that CAV1, either alone or together with eNOS alleles, might modify CRC heritability.

Aged↗

PubMed2005

A new generation of vectors with increased induction ratios by overimposing a second regulatory level by attenuation.

A major drawback of regulated gene expression from vectors bearing strong promoters is the associated high basal expression level. Simple regulatory systems have an intrinsic limitation in the range of induction, and attempts to mutate promoters to reduce basal expression usually result in concomitant reduction of induced levels. We have explored the possibility of reducing basal levels of gene expression while keeping induced levels intact by incorporating an additional regulatory circuit controlling a different step of the expression process. We have integrated the nasFEDCBA transcriptional attenuation system of Klebsiella oxytoca into a cascade expression circuit based on different regulatory elements of Pseudomonas putida, and also into a system based on the tac promoter, to expand their regulatory capacity. Basal expression from the promoters of these circuits was reduced by more than 10-fold by the nasF attenuator sequence while keeping the induced levels intact in the presence of the antiterminator protein, thus increasing the induction ratio by up to 1700-fold. In addition, using different combinations of regulatory elements and inducing conditions, we were able to obtain a broad range of expression levels. These vectors and the concept of their design will be very useful in regulating overproduction of heterologous proteins both at laboratory and industrial scales.

Bacterial Proteins↗

PubMed2004

Stable long-term indigo production by overexpression of dioxygenase genes using a chromosomal integrated cascade expression circuit.

In our laboratory we have analyzed different factors to maximize the yield in heterologous protein expression for long-term cultivation, by combination of an efficient cascade expression system and stable integration in the bacterial chromosome. In this work, we have explored this system for the production of indigo dye as a model for biotechnological production, by expressing in Escherichia coli the thnA1A2A3A4 genes from Sphingomonas macrogolitabida strain TFA, which encode the components of a tetralin dioxygenase activity. We compared Ptac, and the Pm-based cascade expression circuit in a multicopy plasmid and stably integrated into the bacterial chromosome. Plasmid-based expression systems resulted in instability of indigo production when serially diluted batch experiments were performed without a selective pressure. This problem was solved by integrating the expression module in the chromosome. Despite the gene dosage reduction, the synergic effect of the cascade expression system produced comparable expression to the dioxygenase activity in the plasmid configuration but could be stably maintained for at least 5 days. Here, we show that the cascade amplification circuit integrated in the chromosome could be an excellent system for tight control and stable production of recombinant products.

Chromosomes, Bacterial↗