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ObjectiveThe aim of the current study was to investigate the contributing role of gene variation and transcription levels among the m6A methyltransferases METTL3, METTL14, and WTAP in pulmonary tuberculosis (PTB).MethodsA case-control study including 461 PTB patients and 467 normal controls was designed for genotyping. Three SNPs in METTL3 (rs1061027, rs1139130, rs1061026), three SNPs in METTL14 (rs62328061, rs4834698, rs1064034), and two SNPs in WTAP (rs1853259, rs11752345) were genotyped via the SNPscan™ technique. METTL3, METTL14, and WTAP transcription levels were determined in 78 PTB patients and 86 controls via quantitative real-time reverse-transcription PCR.ResultsFrequencies of the METTL14 rs62328061 GG genotype, WTAP rs11752345 CT genotype, and T allele were significantly increased in PTB patients compared to controls. An increased risk of rs62328061 was detected in a recessive model, and a decreased risk of rs11752345 was detected in a dominant model in the PTB group. METTL3 gene variation was not associated with PTB risk. The METTL3 rs1139130 GG genotype was significantly increased with drug resistance, and the G allele was significantly decreased with drug-induced liver injury in PTB patients. A reduced frequency of the METTL14 rs62328061 G allele was associated with leukopenia, a reduced frequency of the WTAP rs11752345 T allele was associated with sputum smear positivity, and a higher frequency of the METTL14 rs4834698 TC genotype was evident in PTB patients with hypoproteinemia. Compared to controls, METTL3, METTL14, and WTAP transcription levels in PTB patients were significantly decreased, and the level of WTAP was increased in PTB patients with drug resistance. METTL3 level was negatively associated with erythrocyte sedimentation rate and aspartate aminotransferase, and METTL14 level was negatively correlated with alanine aminotransferase and aspartate aminotransferase.ConclusionMETTL14 rs62328061 and WTAP rs11752345 variants were associated with the genetic background of PTB, and METTL3, METTL14, and WTAP levels were abnormally decreased, suggesting that these m6A methyltransferases may play important roles in PTB.

The aim of this study was to assess the association of vitamin B12 level and single nucleotide polymorphisms (SNPs) in vitamin B12 metabolic genes with pulmonary tuberculosis (PTB) in Chinese Han population. The plasma vitamin B12 expression level was detected using ELISA. Ten SNPs in six key genes (TCN1, TCN2, CUBN, MMACHC, FUT6, and MUT) of vitamin B12 metabolic pathway were included for genotyping by the SNPscan technique among 454 PTB patients and 467 controls. Our results found that vitamin B12 level was significantly reduced in PTB patients when compared with controls. There was no significant association between TCN1 rs526934, TCN2 rs1801198, CUBN rs7906242, rs10904861, rs1801222, MMACHC rs10789465, FUT6 rs3760776, rs3760775, MUT rs9473555, rs9381784 variants, and PTB susceptibility. TCN2 rs1801198 CC genotype, C allele was significantly associated with hypoproteinemia in PTB patients. In CUBN, rs7906242 GG genotype, G allele, rs10904861 TT genotype, and T allele were significantly related to the decreased frequency of sputum smear-positive, and rs10904861 variant affected the occurrence of drug resistance in PTB patients. In addition, the increased frequency of CUBN rs1801222 AA genotype was significantly associated with leukopenia. The decreased frequency of MUT rs9473555 CC genotype was found in the PTB patients with hypoproteinemia. However, vitamin B12 expression was not associated with the genotype distribution of above SNPs. In conclusion, vitamin B12 level was significantly decreased in PTB patients and genetic variants in vitamin B12 metabolic genes were not contributed to PTB susceptibility. Several SNPs in TCN2, CUBN, and MUT gene might associate with multiple clinical manifestations in PTB.

The aryl hydrocarbon receptor (AHR) signaling pathway participates in immune regulation of multiple autoimmune diseases, including rheumatoid arthritis (RA). We conducted this study to investigate the association of AHR signaling pathway genes (AHR, ARNT, AHRR) single nucleotide polymorphisms (SNPs), as well as their methylation levels, with RA susceptibility. Nine SNPs (AHR gene rs2066853, rs2158041, rs2282885, ARNT gene rs10847, rs1889740, rs11204735, AHRR gene rs2292596, rs2672725, rs349583) were genotyped via improved multiple ligase detection reaction (iMLDR) in 479 RA patients and 496 healthy controls. We used the Illumina Hiseq platform to detect methylation levels of these genes in 122 RA patients and 123 healthy controls. A significant increase in rs11204735 C allele frequency was observed in RA patients when compared to controls. Further, rs11204735 polymorphism was associated with a decreased risk of RA under the dominant model. ARNT CCC haplotype frequency was significantly increased in RA patients in comparison to controls. In the AHRR gene, rs2672725 GG genotype, G allele frequencies were significantly related to an increased risk of RA and rs2292596, rs2672725 polymorphism were significantly associated with an increased risk of RA under the dominant model, recessive model, respectively. However, no significant association was identified between AHR gene polymorphism and RA susceptibility. The AHR methylation level in RA patients was significantly higher than the controls, while AHRR methylation level was abnormally reduced in RA patients. In addition, AHRR rs2672725 genotype distribution was significantly associated with the AHRR methylation level among RA patients. In summary, ARNT rs11204735, AHRR rs2292596, and rs2672725 polymorphisms were associated with RA susceptibility and altered AHR, AHRR methylation levels were related to the risk of RA.

ObjectivesPeriodontitis (PD) has been linked to arthritis in previous epidemiological observational studies; however, the results are inconclusive. It remains unclear whether the association between PD and arthritis is causal. The purpose of this study was to investigate the causal association of PD with arthritis, including rheumatoid arthritis (RA) and osteoarthritis (OA).MethodsWe performed a two-sample bidirectional Mendelian randomization (MR) analysis using publicly released genome-wide association studies (GWAS) statistics. The inverse-variance weighted (IVW) method was used as the primary analysis. We applied four complementary methods, including weighted median, weighted mode, MR-Egger regression and MR pleiotropy residual sum and outlier (MR-PRESSO) to detect and correct for the effect of horizontal pleiotropy.ResultsGenetically determined PD did not have a causal effect on OA (OR = 1.06, 95% CI: 0.99-1.15, P = 0.09) and RA (OR = 0.99, 95% CI: 0.87-1.13, P = 0.89). Furthermore, we did not find a significant causal effect of arthritis on PD in the reverse MR analysis. The results of MR-Egger regression, Weighted Median, and Weighted Mode methods were consistent with those of the IVW method. Horizontal pleiotropy was unlikely to distort the causal estimates according to the sensitivity analysis.ConclusionsOur MR analysis reveals non-causal association of PD with arthritis, despite observational studies reporting an association between PD and arthritis.