50 research outputs found
Application of anin silicoapproach identifies a genetic locus withinITGB2,and itsinteractions withHSPG2 and FGF9,to be associated with anterior cruciateligament rupture risk
We developed a Biomedical Knowledge Graph model that is phenotype and biological function-aware through integrating knowledge from multiple domains in a Neo4j, graph database. Allknown human genes were assessed through the model to identify potential new risk genes foranterior cruciate ligament (ACL) ruptures and Achilles tendinopathy (AT). Genes were prioritisedand explored in a case–control study comparing participants with ACL ruptures (ACL-R),including a sub-group with non-contact mechanism injuries (ACL-NON), to uninjured controlindividuals (CON). After genefiltering, 3376 genes, including 411 genes identified throughprevious whole exome sequencing, were found to be potentially linked to AT and ACL ruptures.Four variants were prioritised:HSPG2:rs2291826A/G,HSPG2:rs2291827G/A,ITGB2:rs2230528C/TandFGF9:rs2274296C/T. The rs2230528 CC genotype was over-represented in the CON groupcompared to ACL-R (p< 0.001) and ACL-NON (p< 0.001) and the TT genotype and T allele wereover-represented in the ACL-R group and ACL-NON compared to CON (p< 0.001) group. Severalsignificant differences in distributions were noted for the gene-gene interactions: (HSPG2:rs2291826, rs2291827 andITGB2:rs2230528) and (ITGB2:rs2230528 andFGF9:rs2297429)
Semantic interrogation of a multi knowledge domain ontological model of tendinopathy identifies four strong candidate risk genes
Tendinopathy is a multifactorial syndrome characterised by tendon pain and thickening, and impaired
performance during activity. Candidate gene association studies have identified genetic factors
that contribute to intrinsic risk of developing tendinopathy upon exposure to extrinsic factors.
Bioinformatics approaches that data-mine existing knowledge for biological relationships may assist
with the identification of candidate genes. The aim of this study was to data-mine functional annotation
of human genes and identify candidate genes by ontology-seeded queries capturing the features of
tendinopathy. Our BioOntological Relationship Graph database (BORG) integrates multiple sources of
genomic and biomedical knowledge into an on-disk semantic network where human genes and their
orthologs in mouse and rat are central concepts mapped to ontology terms. The BORG was used to
screen all human genes for potential links to tendinopathy. Following further prioritisation, four strong
candidate genes (COL11A2, ELN, ITGB3, LOX) were identified. These genes are differentially expressed
in tendinopathy, functionally linked to features of tendinopathy and previously implicated in other
connective tissue diseases. In conclusion, cross-domain semantic integration of multiple sources of
biomedical knowledge, and interrogation of phenotypes and gene functions associated with disease,
may significantly increase the probability of identifying strong and unobvious candidate genes in
genetic association studies
Defining the molecular signatures of Achilles tendinopathy and anterior cruciate ligament ruptures: A whole-exome sequencing approach
Musculoskeletal soft tissue injuries are complex phenotypes with genetics being one of
many proposed risk factors. Case-control association studies using the candidate gene
approach have predominately been used to identify risk loci for these injuries. However, the
ability to identify all risk conferring variants using this approach alone is unlikely. Therefore,
this study aimed to further define the genetic profile of these injuries using an integrated
omics approach involving whole exome sequencing and a customised analyses pipeline.
The exomes of ten exemplar asymptomatic controls and ten exemplar cases with Achilles
tendinopathy were individually sequenced using a platform that included the coverage of
the untranslated regions and miRBase miRNA genes. Approximately 200 000 variants were
identified in the sequenced samples. Previous research was used to guide a targeted analysis
of the genes encoding the tenascin-C (TNC) glycoprotein and the α1 chain of type XXVII
collagen (COL27A1) located on chromosome 9. Selection of variants within these genes
were; however, not predetermined but based on a tiered filtering strategy. Four variants in
TNC (rs1061494, rs1138545, rs2104772 and rs1061495) and three variants in the upstream
COL27A1 gene (rs2567706, rs2241671 and rs2567705) were genotyped in larger Achilles
tendinopathy and anterior cruciate ligament (ACL) rupture sample groups. The CC genotype
of TNC rs1061494 (C/T) was associated with the risk of Achilles tendinopathy (p = 0.018,
OR: 2.5 95% CI: 1.2–5.1). Furthermore, the AA genotype of the TNC rs2104772 (A/T) variant
was significantly associated with ACL ruptures in the female subgroup (p = 0.035, OR:
2.3 95% CI: 1.1–5.5). An inferred haplotype in the TNC gene was also associated with the
risk of Achilles tendinopathy. These results provide a proof of concept for the use of a customised
pipeline for the exploration of a larger genomic dataset. This approach, using previous
research to guide a targeted analysis of the data has generated new genetic signatures
in the biology of musculoskeletal soft tissue injuries.IS
A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading.
It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3 km.h-1 with loads of 0, 3, 6, 9, 12, 15 and 20 kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p = 0.483), despite differences in the change in trunk forward lean (p = 0.001) and trunk angle excursion (p = 0.021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements
Inflammatory Cytokine Profiles of Semen Influence Cytokine Responses of Cervicovaginal Epithelial Cells
Genital inflammatory cytokine responses increase HIV risk. Since male partner semen is a complex mixture of immune-modulatory prostaglandins and cytokines, we hypothesized that exposure to semen may influence genital inflammation in women. Here, we investigated cytokine response kinetics of cervical cells following stimulation with seminal plasma from HIV-negative and HIV-positive men characterized as having low or high concentrations of inflammatory cytokines. Irrespective of the HIV status or semen cytokine profile, in vitro stimulation of cervical cells with seminal plasma resulted in significantly elevated concentrations of secreted IL-6, IL-8, TNF-β, MCP-1, GM-CSF, and VEGF within 8 h of stimulation, which tended to decline by 24 h, although this was only significant for TNF-β. Consistent with this, cervical cells responded to seminal plasma with increases in IL-8 and IL-1β mRNA expression of 10-fold. These findings suggest that the impact of semen on local female genital cytokines is likely transient. Although these findings suggest that the impact of semen on local female genital cytokines may not be sustained long-term, this heightened genital inflammation may have implications for HIV risk in women
The development of computational biology in South Africa: successes achieved and lessons learnt
Bioinformatics is now a critical skill in many research and commercial environments as biological data are increasing in both size and complexity. South African researchers recognized this need in the mid-1990s and responded by working with the government as well as international bodies to develop initiatives to build bioinformatics capacity in the country. Significant injections of support from these bodies provided a springboard for the establishment of computational biology units at multiple universities throughout the country, which took on teaching, basic research and support roles. Several challenges were encountered, for example with unreliability of funding, lack of skills, and lack of infrastructure. However, the bioinformatics community worked together to overcome these, and South Africa is now arguably the leading country in bioinformatics on the African continent. Here we discuss how the discipline developed in the country, highlighting the challenges, successes, and lessons learnt
First Description of Natural and Experimental Conjugation between Mycobacteria Mediated by a Linear Plasmid
Background: in a previous study, we detected the presence of a Mycobacterium avium species-specific insertion sequence, IS1245, in Mycobacterium kansasii. Both species were isolated from a mixed M. avium-M. kansasii bone marrow culture from an HIV-positive patient. the transfer mechanism of this insertion sequence to M. kansasii was investigated here.Methodology/Principal Findings: A linear plasmid (pMA100) was identified in all colonies isolated from the M. avium-M. kansasii mixed culture carrying the IS1245 element. the linearity of pMA100 was confirmed. Other analyses suggested that pMA100 contained a covalently bound protein in the terminal regions, a characteristic of invertron linear replicons. Partial sequencing of pMA100 showed that it bears one intact copy of IS1245 inserted in a region rich in transposase-related sequences. These types of sequences have been described in other linear mycobacterial plasmids. Mating experiments were performed to confirm that pMA100 could be transferred in vitro from M. avium to M. kansasii. pMA100 was transferred by in vitro conjugation not only to the M. kansasii strain from the mixed culture, but also to two other unrelated M. kansasii clinical isolates, as well as to Mycobacterium bovis BCG Moreau.Conclusions/Significance: Horizontal gene transfer (HGT) is one of most important mechanisms leading to the evolution and diversity of bacteria. This work provides evidence for the first time on the natural occurrence of HGT between different species of mycobacteria. Gene transfer, mediated by a novel conjugative plasmid, was detected and experimentally reproduced.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Cooperacion Interuniversitaria UAM-Banco Santander con America Latina (CEAL), UAM, SpainConselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, Escola Paulista Med, São Paulo, BrazilLab Nacl Comp Cient, Petropolis, BrazilUniv Autonoma Madrid, Fac Med, Dept Prevent Med, Madrid, SpainInst Adolfo Lutz Registro, Nucleo TB & Micobacterioses, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, Escola Paulista Med, São Paulo, BrazilFAPESP: FAPESP - 06/01533-9Web of Scienc
p16 Mutation Spectrum in the Premalignant Condition Barrett's Esophagus
Background: Mutation, promoter hypermethylation and loss of heterozygosity involving the tumor suppressor gene p16 (CDKN2a/INK4a) have been detected in a wide variety of human cancers, but much less is known concerning the frequency and spectrum of p16 mutations in premalignant conditions. Methods and Findings: We have determined the p16 mutation spectrum for a cohort of 304 patients with Barrett’s esophagus, a premalignant condition that predisposes to the development of esophageal adenocarcinoma. Forty seven mutations were detected by sequencing of p16 exon 2 in 44 BE patients (14.5%) with a mutation spectrum consistent with that caused by oxidative damage and chronic inflammation. The percentage of patients with p16 mutations increased with increasing histologic grade. In addition, samples from 3 out of 19 patients (15.8%) who underwent esophagectomy were found to have mutations. Conclusions: The results of this study suggest the environment of the esophagus in BE patients can both generate an