Particulate Air Pollution Exposure and Expression of Viral and Human MicroRNAs in Blood: The Beijing Truck Driver Air Pollution Study.

BACKGROUND: MicroRNAs (miRNAs) are post-transcriptional gene suppressors and potential mediators of environmental effects. In addition to human miRNAs, viral miRNAs expressed from latent viral sequences are detectable in human cells. OBJECTIVE: In a highly exposed population in Beijing, China, we evaluated the associations of particulate air pollution exposure on blood miRNA profiles. METHODS: The Beijing Truck Driver Air Pollution Study (BTDAS) included 60 truck drivers and 60 office workers. We investigated associations of short-term air pollution exposure, using measures of personal PM2.5 (particulate matter ≤ 2.5 µm) and elemental carbon (EC), and ambient PM10 (≤ 10 µm), with blood NanoString nCounter miRNA profiles at two exams separated by 1-2 weeks. RESULTS: No miRNA was significantly associated with personal PM2.5 at a false discovery rate (FDR) of 20%. Short-term ambient PM10 was associated with the expression of 12 miRNAs in office workers only (FDR < 20%). Short-term EC was associated with differential expression of 46 human and 7 viral miRNAs, the latter including 3 and 4 viral miRNAs in office workers and truck drivers, respectively. EC-associated miRNAs differed between office workers and truck drivers with significant effect modification by occupational group. Functional interaction network analysis suggested enriched cellular proliferation/differentiation pathways in truck drivers and proinflammation pathways in office workers. CONCLUSIONS: Short-term EC exposure was associated with the expression of human and viral miRNAs that may influence immune responses and other biological pathways. Associations between EC exposure and viral miRNA expression suggest that latent viral miRNAs are potential mediators of air pollution-associated health effects. PM2.5/PM10 exposures showed no consistent relationships with miRNA expression.

Mutational analysis of telomere complex genes in Indian population with acquired aplastic anemia.

BACKGROUND: Acquired aplastic anemia (AAA) is rare disorders caused due to the profound or almost complete bone marrow failure. It is a life threatening hematopoietic stem cells disorder, which is characterized by pancytopenia or complete loss of blood-forming cells. The aim of the present study is to screen for the mutations in telomerase complex genes, and to establish a molecular and hematological profile of Indian sub population. METHODOLOGY: We have conducted a case control study of total 70 participants; 50 patients, who fulfilled the blood count and bone marrow criteria of the International agranulocytosis & AAA, and 20 healthy controls. These samples were selected from hematology clinics at Jaipur, India, during the period of two years (January 2012-December 2013). We screened four telomere complex genes; TERT, DKC1, NOP10 and NHP2 of mutations at single base pair in sampled blood and bone marrows. We have predicated the consequences of mutations on protein structure using 3D multilevel modeling protein structure software Phyre2, PolyPhen2 and YASARA. RESULTS: The hematological and molecular basis of acquired aplastic anemia was investigated in 50 anemia patients and 20 healthy controls. AAA patients showed hematologic abnormalities (macrocytic anemia, thrombocytopenia, & granulocytopenia) in peripheral blood and severe hypoplastic bone marrows. Screening of telomere complex genes TERT, DKC1, NOP10 and NHP2 in AAA patients and controls revealed; novel and reported mutations in TERT and DKC1, whereas, no pathogenic mutations were observed in NOP10 and NHP2 genes. In TERT gene, one non-synonymous mutation (Chr5: 1287,825 C→T; Arg979Trp) was identified in exon 12 and two heterozygous non-synonymous mutations (Chr X: 153,994,542 T→K; Val105Gly & Chr X: 153,994,591 T→K; Ser121Arg) were found in exon 5 of DKC1 gene. To determine and visualize the possible effect of TERT and DKC1 mutations on protein structure YASARA with FoldX functionality has been used and many structural consequences were found that might destabilize the protein. Predicated structural consequences may destabilize the TERT and DKC1 proteins ultimately causing blood disorders.. CONCLUSION: The present study indicates the mutation spectrum in the genes implicated in AAA, i.e. TERT, DKC1, NOP10 and NHP2 on small case-control group in an Indian sub population.

ExcellmiRDB for translational genomics: a curated online resource for extracellular microRNAs.

A large number of studies have suggested extracellular microRNAs (microRNAs in biofluids) as potential noninvasive biomarkers for pathophysiological conditions such as cancer. However, reported differentially expressed signatures of extracellular miRNAs in diseases are not uniformly consistent among studies. Here, we present "ExcellmiRDB", a curated online database that provides integrated information about miRNAs levels in biofluids in a user-friendly way. Although many miRNA databases, including disease-oriented databases, have been launched before, the ExcellmiRDB is so far the only one specialized for storing curated data on miRNA levels in biofluid samples. At present, ExcellmiRDB has 2773 disease-extracellular miRNAs and 1108 biofluid-extracellular miRNAs relationships curated from 108 articles selected from more than 600 surveyed PubMed abstracts. Information about 992 miRNAs, 82 diseases, 21 biofluids, 8 species, 63 normalization reference genes, 5 techniques, 14 GEO profiles accession numbers, 7 human ethnic groups, and 18 compared clinical biomarkers have been provided in the database. A user can query ExcellmiRDB by selecting a disease or a miRNA or a biofluid. Additionally, the database provides two online network graphs to visualize and interact with the content of the database. The first network shows disease-extracellular miRNAs relationships, along with expression patterns and number of articles for a relationship. The second network visualizes biofluid-extracellular miRNAs relationships showing miRNAs spectrum across different types of biofluids. In conclusion, ExcellmiRDB is a new innovative resource for both academic and industrial researchers in translational omics who are developing miRNA biomarkers for noninvasive diagnostic or prognostic technologies. ExcellmiRDB is publicly available on www.excellmirdb.brfjaisalmer.com/.

Effects of short-term exposure to inhalable particulate matter on DNA methylation of tandem repeats.

There is compelling evidence that particulate matter (PM) increases lung cancer risk by triggering systemic inflammation, and leukocyte DNA hypomethylation. However, previous investigations focused on repeated element sequences from LINE-1 and Alu families. Tandem repeats, which display a greater propensity to mutate, and are often hypomethylated in cancer patients, have never been investigated in individuals exposed to PM. We measured methylation of three tandem repeats (SATα, NBL2, and D4Z4) by polymerase chain reaction-pyrosequencing on blood samples from truck drivers and office workers (60 per group) in Beijing, China. We used lightweight monitors to measure personal PM2.5 (PM with aerodynamic diameter ≤2.5 µm) and elemental carbon (a tracer of PM from vehicular traffic). Ambient PM10 data were obtained from air quality measuring stations. Overall, an interquartile increase in personal PM2.5 and ambient PM10 levels was associated with a significant covariate-adjusted decrease in SATα methylation (-1.35% 5-methyl cytosine [5mC], P = 0.01; and -1.33%5mC; P = 0.01, respectively). Effects from personal PM2.5 and ambient PM10 on SATα methylation were stronger in truck drivers (-2.34%5mC, P = 0.02; -1.44%5mC, P = 0.06) than office workers (-0.95%5mC, P = 0.26; -1.25%5mC, P = 0.12, respectively). Ambient PM10 was negatively correlated with NBL2 methylation in truck drivers (-1.38%5mC, P = 0.03) but not in office workers (1.04%5mC, P = 0.13). Our result suggests that PM exposure is associated with hypomethylation of selected tandem repeats. Measuring tandem-repeat hypomethylation in easy-to-obtain blood specimens might identify individuals with biological effects and potential cancer risk from PM exposure.