Antonio Miranda-Duarte

Altered Expression of Circulating MicroRNA in Plasma of Patients with Primary Osteoarthritis and In Silico Analysis of Their Pathways

Objective To analyze a set of circulating microRNA (miRNA) in plasma from patients with primary Osteoarthritis (OA) and describe the biological significance of altered miRNA in OA based on an in silico analysis of their target genes. Methods miRNA expression was analyzed using TaqMan Low Density Arrays and independent assays. The search for potential messenger RNA (mRNA) targets of the differentially expressed miRNA was performed by means of the miRWalk and miRecords database; we conducted the biological relevance of the predicted miRNA targets by pathway analysis with the Reactome and DAVID databases. Results We measured the expression of 380 miRNA in OA; 12 miRNA were overexpressed under the OA condition (p value, ≤0.05; fold change, >2). These results were validated by the detection of some selected miRNA by quantitative PCR (qPCR). In silico analysis showed that target messenger RNA (mRNA) were potentially regulated by these miRNA, including genes such as SMAD1, IL-1B, COL3A, VEGFA, and FGFR1, important in chondrocyte maintenance and differentiation. Some metabolic pathways affected by the miRNA: mRNA ratio are signaling Bone morphogenetic proteins (BMP), Platelet-derived growth factor (PDGF), and Nerve growth factor (NGF), these latter two involved in the process of pain. Conclusions We identified 12 miRNA in the plasma of patients with primary OA. Specific miRNA that are altered in the disease could be released into plasma, either due to cartilage damage or to an inherent cellular mechanism. Several miRNA could regulate genes and pathways related with development of the disease; eight of these circulating miRNA are described, to our knowledge, for first time in OA.

Genome-wide mRNA analysis reveals a TUBD1 isoform profile as a potential biomarker for diabetic retinopathy development

Abstract Diabetic retinopathy (DR) affects approximately one third of all diabetic subjects and is the leading cause of blindness in young to middle‐aged adults in the developed world. While early diagnosis is crucial for preventing DR‐associated visual loss, the identification of accessible biomarkers that could lead to presymptomatic recognition of the disease is of great clinical importance. The aim of this work was to investigate the possible involvement of alternative splicing events in DR development by performing a genome‐wide transcriptional profiling comparing blood‐derived RNA from DR subjects and from diabetic‐non DR controls. A total of 95 RNA samples, 67 from patients with bilateral DR and 28 from diabetic patients without DR after a period of at least 10 years with type 2 DM, were compared in a genome‐wide transcriptome analysis using the GeneChip® Human Gene 2.0 ST Array which contains probe sets covering all exons of ˜33,500 coding transcripts of annotated genes. Microarray data analysis followed by RT‐PCR and cDNA sequencing identified important differential splicing events in TUBD1 (Tubulin, Delta‐1) isoforms between DR and DM samples. Specifically, the co‐expression of particular TUBD1 isoforms was significantly associated with NPDR risk (p = 0.039 by Pearsons chi‐squared test; OR (CI 95%): 8.1 (1.0–72.7)). Analysis of TUBD1 signal pathways and regulating networks using a MetaCore platform showed that HIF‐1, a molecule playing an important role in the pathogenesis of DR, is a direct regulator of TUBD1 expression. In conjunction, our data suggest that TUBD1 mRNA isoform expression profile in peripheral blood could be an accessible biomarker for predicting the risk for diabetic retinopathy development. HighlightsInvolvement of alternative splicing in diabetic retinopathy (DR) was investigated.Blood RNA samples from DR (n = 67) and from non‐DR patients (n = 28) were compared.GeneChip Human Gene 2.0 ST Arrays were used for genome‐wide transcriptome analysis.Co‐expression of particular TUBD1 isoforms were associated with DR occurrence risk.TUBD1 isoforms profile could be an accessible biomarker for predicting DR development.

D14 repeat polymorphism of the asporin gene is associated with primary osteoarthritis of the knee in a Mexican Mestizo population

Asporin is a novel extracellular matrix protein (ECM) with an important role in the development of osteoarthritis (OA), because it has been reported that functional polymorphisms in the aspartic acid repeat (D) of the asporin gene (ASPN) are associated with susceptibility to OA.

Epidemiological and Molecular Characterization of a Mexican Population Isolate with High Prevalence of Limb-Girdle Muscular Dystrophy Type 2A Due to a Novel Calpain-3 Mutation

Limb-Girdle Muscular Dystrophy type 2 (LGMD2) is a group of autosomally recessive inherited disorders defined by weakness and wasting of the shoulder and pelvic girdle muscles. In the past, several population isolates with high incidence of LGMD2 arising from founder mutation effects have been identified. The aim of this work is to describe the results of clinical, epidemiologic, and molecular studies performed in a Mexican village segregating numerous cases of LGMD2. A population census was conducted in the village to identify all LGMD affected patients. Molecular analysis included genome wide homozygosity mapping using a 250K SNP Affymetrix microarray followed by PCR amplification and direct nucleotide sequencing of the candidate gene. In addition, DNA from 401 randomly selected unaffected villagers was analyzed to establish the carrier frequency of the LGMD2 causal mutation. A total of 32 LGMD2 patients were identified in the village, rendering a disease prevalence of 4.3 (CI: 2.9–5.9) cases per 1,000 habitants (1 in 232). Genome wide homozygosity mapping revealed that affected individuals shared a 6.6 Mb region of homozygosity at chromosome 15q15. The identified homozygous interval contained CAPN3, the gene responsible for LGMD2 type A (LGMD2A). Direct sequencing of this gene revealed homozygosity for a novel c.348C>A mutation (p.Ala116Asp) in DNA from all 20 affected subjects available for genetic screening, except one which was heterozygous for the mutation. In such patient, a heterozygous c.2362AG>TCATCT deletion/insertion was recognized as the second CAPN3 mutation. Western blot and autocatalytic activity analyses in protein lysates from skeletal muscle biopsy obtained from a p.Ala116Asp homozygous patient suggested that this particular mutation increased the autocatalytic activity of CAPN3. Thirty eigth heterozygotes of the p.Ala116Asp mutation were identified among 401 genotyped unaffected villagers, yielding a population carrier frequency of 1 in 11. This study demonstrates that a cluster of patients with LGMD2A in a small Mexican village arises from a novel CAPN3 founder mutation. Evidence of allelic heterogeneity is demonstrated by the recognition of an additional CAPN3 mutation in a single affected. Our study provides an additional example of genetic isolation causing a high prevalence of LGMD and of successful molecular characterization of the disease by means of homozygosity mapping. The identification of a very high carrier frequency of the LGMD2-causing mutation has implications for more rational genetic counseling in this community.

ASSOCIATION STUDY BETWEEN POLYMORPHISMS OF THE p53 AND LYMPHOTOXIN ALPHA (LTA) GENES AND THE RISK OF PROLIFERATIVE VITREORETINOPATHY/RETINAL DETACHMENT IN A MEXICAN POPULATION.

Purpose: To report the results of an association study between single-nucleotide polymorphisms of the p53 and LTA genes and the risk of proliferative vitreoretinopathy (PVR)/retinal detachment (RD) in a Mexican cohort. Methods: A total of 380 unrelated subjects were studied, including 98 patients with primary rhegmatogenous RD without PVR, 82 patients with PVR after RD surgery, and 200 healthy, ethnically matched subjects. Genotyping of single-nucleotide polymorphisms rs1042522 (p53 gene) and rs2229094 (LTA gene) was performed by direct nucleotide sequencing. Allele frequencies, genotype frequencies, and Hardy–Weinberg equilibrium were assessed with HaploView software. Results: No significant differences in the allelic distributions of the previously identified risk C allele for LTA rs2229094 were observed between RD subjects and controls (odds ratio [95% confidence interval] = 0.8 [0.5–1.2]; P = 0.3). Conversely, the C allele for rs1042522 in p53 was positively associated with an increased risk for RD (odds ratio [95% confidence interval] = 1.4 [1.01–1.9]; P = 0.04). No significant differences were observed when the subgroup of 82 RD + PVR subjects was compared with the subgroup of 98 patients with RD. Conclusion: The C allele for rs1042522 in p53 was genetically associated with a higher risk for RD but not for PVR in this cohort. This is the first association study attempting replication of PVR-associated risk alleles in a nonwhite population.

Genetic association analysis of Osteopontin and Matrix Gla Protein genes polymorphisms with primary knee osteoarthritis in Mexican population

Primary osteoarthritis (OA) is a complex entity in which several loci related to different molecular pathways or classes of molecules are associated with its development as demonstrated through genetic association studies. Genes involved in bone formation and mineralization, such as osteopontin (OPN) and Matrix Gla protein (MGP), could also be related with OA. The aim of this study was to evaluate the association between the genetic variants of OPN and MGP with primary knee osteoarthritis in a Mexican population. A case-control study was conducted in 296 patients with primary knee osteoarthritis and in 354 control subjects. Study groups were assessed radiologically. The rs11730582 of OPN and rs1800802, rs1800801, and rs4236 of MGP were determined by TaqMan allele discrimination assays. The haplotypes of the polymorphisms of MGP were constructed. The association was tested through univariate and multivariate non-conditional logistic regression analyses. The polymorphisms of MGP complied with Hardy-Weinberg (HW) equilibrium. The polymorphisms of OPN and MGP were not significantly associated with primary knee osteoarthritis in the codominant, dominant, and recessive models (p > 0.05). Our study suggests that there are no associations between OPN and MGP polymorphisms with primary knee osteoarthritis in Mexican population.