Investigating causal associations among gut microbiota, metabolites, and psoriatic arthritis: a Mendelian randomization study.

Background: Currently, there has been observed a significant alteration in the composition of the gut microbiome (GM) and serum metabolites in patients with psoriatic arthritis (PsA) compared to healthy individuals. However, previous observational studies have shown inconsistent results regarding the alteration of gut microbiota/metabolites. In order to shed light on this matter, we utilized Mendelian randomization to determine the causal effect of GM/metabolites on PsA. Methods: We retrieved summary-level data of GM taxa/metabolites and PsA from publicly available GWAS statistics. Causal relationships between GM/metabolites and PsA were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the robustness of our findings, we conducted sensitivity analyses, multivariable MR analysis (MVMR), and additional analysis including replication verification analysis, LDSC regression, and Steiger test analysis. Furthermore, we investigated reverse causality through a reverse MR analysis. Finally, we conducted an analysis of expression quantitative trait loci (eQTLs) involved in the metabolic pathway to explore potential molecular mechanisms of metabolism. Results: Our findings reveal that eight GM taxa and twenty-three serum metabolites are causally related to PsA (P < 0.05). Notably, a higher relative abundance of Family Rikenellaceae (ORIVW: 0.622, 95% CI: 0.438-0.883, FDR = 0.045) and elevated serum levels of X-11538 (ORIVW: 0.442, 95% CI: 0.250-0.781, FDR = 0.046) maintain significant causal associations with a reduced risk of PsA, even after adjusting for multiple testing correction and conducting MVMR analysis. These findings suggest that Family Rikenellaceae and X-11538 may have protective effects against PsA. Our sensitivity analysis and additional analysis revealed no significant horizontal pleiotropy, reverse causality, or heterogeneity. The functional enrichment analysis revealed that the eQTLs examined were primarily associated with glycerolipid metabolism and the expression of key metabolic factors influenced by bacterial infections (Vibrio cholerae and Helicobacter pylori) as well as the mTOR signaling pathway. Conclusion: In conclusion, our study demonstrates that Family Rikenellaceae and X-11538 exhibit a strong and negative causal relationship with PsA. These particular GM taxa and metabolites have the potential to serve as innovative biomarkers, offering valuable insights into the treatment and prevention of PsA. Moreover, bacterial infections and mTOR-mediated activation of metabolic factors may play an important role in this process.

The complete chloroplast genome of Kolkwitzia amabilis (Caprifoliaceae), an endangered horticultural plant in China.

The complete chloroplast genome of Kolkwitzia amabilis (Caprifoliaceae) is first presented in the current study. The cp genome of K. amabilis was 156 875 bp in length and composed of two short inverted repeat (IRa and IRb) regions of 23 946 bp which were separated by a small single copy (SSC) region of 18 846 bp and a large single copy (LSC) region of 90 137 bp. The genome encoded 130 genes contained 81 coding genes, 39 tRNA genes, and 8 rRNA genes. The overall AT content of K. amabilis is 61.6% and the corresponding values of the SSC, LSC and IR regions are 66.8%, 64.1%, and 57.3%, respectively. The phylogenetic analysis based on the maximum parsimony tree revealed that K. amabilis was closely related to Lonicera japonica.

The complete chloroplast genome of Dipteronia sinensis (Aceraceae), an endangered endemic species to China.

The complete chloroplast sequence of D. sinensis was reported in this study. The total length was 157 080 bp containing a pair of 26 766 bp inverted repeat regions (IRa and IRb), which were separated by a small single copy regions and a large single copy regions (SSC and LSC) of 18 093 and 85 455 bp, respectively. A total of 138 functional genes were annotated, which included 90 protein-coding genes, 40 tRNAs, and eight rRNA genes. The overall GC content of the complete chloroplast genome is 37.8% and in LSC, SSC and IR regions were 35.9%, 32.1%, and 42.7%, respectively. The maximum likelihood (ML) phylogenetic analysis revealed that D. sinensis was closely related to A. buergerianum subsp. Ningpoense in Sapindales order.