Man, X. | Search bioRxiv

bioRxiv2023

Berberine reduce inflammation in RA rats through MCP1/CCR2 pathway

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent synovitis and systemic inflammation, leading to joint damage and functional disability. Current treatment modalities, although effective, may pose significant side effects. In this study, we investigated the anti-inflammatory properties of berberine, a natural isoquinoline alkaloid, and its potential role in ameliorating RA-associated inflammation in rats through modulation of the monocyte chemoattractant protein-1 (MCP1)/chemokine receptor 2 (CCR2) pathway. A collagen-induced arthritis (CIA) rat model was employed to mimic RA pathophysiology. Rats were treated with berberine or RS504393 for 30 days. Joint swelling, arthritis score, histopathology used to evaluate disease progression and the extent of inflammation. Immunohistochemistry and WB were used to detect the mechanism of action of berberine. Our results demonstrated that berberine treatment significantly reduced joint swelling, and inflammatory factors in CIA rats. Furthermore, berberine downregulated MCP1 and CCR2 expression, implicating the involvement of the MCP1/CCR2 signaling pathway in attenuating RA-associated inflammation. Taken together, our findings suggest that berberine may represent a promising therapeutic candidate for the management of RA and highlight the potential of targeting the MCP1/CCR2 pathway to mitigate inflammation in autoimmune diseases.

cell biology↗

bioRxiv2023

Dominant Role of Stochastic Processes in Soil Fungal Communities in Pioneer Forests at a Regional Scale

Soil fungal community assembly is driven by deterministic and stochastic processes. However, the contribution of these mechanisms to structure the composition of fungal communities of forest soils at the regional scale is poorly known. Here, we investigate the relative importance of deterministic and stochastic processes on fungal community composition by rDNA ITS metabarcoding in a Populus davidiana pioneer forests along spatial-temporal gradients. We also assessed the impact of elevation and seasonality. The soil fungal richness of P. davidiana pioneer forests was significantly affected by elevation and less affected by season. Similarly, the variation in the fungal community composition according to the elevation was greater than the effect of seasonality. The fungal community composition showed a significant distance-decay relationship. Variation partitioning analysis showed that plant variables explained the soil fungal community variation. Through null model analysis, we found that stochastic processes were dominant in the soil fungal community assembly. However, the relative importance of ecological processes, including dispersal, selection, and drift, was not consistent across the four soil fungal community assemblies. In addition, the undominated fraction (including weak selection, weak dispersal, diversification and drift) had a high relative contribution to the soil fungal community assembly process in the P. davidiana pioneer forest. In summary, our results demonstrated that plant variables and the undominated fraction dominate the deterministic and stochastic processes driving soil fungal community assemblies in a P. davidiana pioneer forest at the regional scale, which provides new perspectives for the regional scale studies of soil fungi. IMPORTANCEElevation and seasonality are important factors driving the composition of soil microbiota. Due to the tight interactions of soil fungi with their host trees in forest ecosystems, the spatial variation of soil fungal community is often linked to the variation in the composition of dominant tree species. We compared the responses of soil fungal communities to seasonal and spatial changes at four levels in a temperate poplar forest dominated by a single tree species under elevation changes. Elevation had a higher impact than seasonality on the soil fungal beta diversity. Even when the shift in dominant tree species was limited, vegetation factors still impact soil fungal community variations. The dominant role of homogeneous selection and drift in fungal community assemblies, except for ectomycorrhizal fungi, was further discovered.

microbiology↗