IL-27-induced, MSC-derived Exosomes Promote MMP3 Expression Through the miR-206/L3MBTL4 Axis in Synovial Fibroblasts.

Context: In rheumatoid arthritis (RA), hyperproliferative fibroblast-like synoviocytes (FLS) can secrete a variety of tissue hydrolases, such as matrix metalloproteinases (MMPs), causing the destruction of chondrocytes. Mesenchymal stem cells (MSCs) can directly affect FLS through extracellular vesicles (EVs). Interleukin-27 (IL-27) is a pleiotropic immune regulator frequently overexpressed in RA. Objective: The study intended to examine the effects of IL-27-induced exosomes from bone-marrow mesenchymal stem cells (BM-MSCs) and to determine if they promote the secretion of MMP3 in synovial cells. Design: The research team performed a genetic study. Setting: The study took place at the First Affiliated Hospital of Hainan Medical University in Haikou City, Hainan, China. Outcome Measures: The research team: (1) determined if IL-27 expression had occurred in the synovial fluid; (2) co-cultured IL-27-induced MSCs with FLS to detect the expression of MMP3 in the FLS; (3) Under IL-27 induction, MSC-derived exosomes with IL-27R knockdown were collected to detect the expression of microRNAs(miRNAs) associated with RA; (4) screened the miRNAs to determine the most significant differences in expression; (5) determined the miRNA target genes in arthritis, using Western blot (WB) and qRT-PCR; and (6) Dual luciferase and ChIP experiments confirm regulation of MMP3 by L3MBTL4. Results: IL-27 was highly expressed in RA, and the IL-27-induced, MSC-derived exosomes promoted the expression of MMP3 in FLS. The IL-27-induced MSC-derived exosomes significantly upregulated the expression of miR-206-3p, and the miR-206-3p target, miR-206/ lethal(3) malignant brain tumor-like protein 4 (L3MBTL4), regulated the MMP3 transcription. The IL-27-induced, MSC-derived exosomes promoted MMP3 expression in the FLS through the miR-206-3p/L3MBTL4 axis, thereby promoting chondrocyte degradation and aggravating RA. Conclusions: IL-27 can induce the expression of miR-206 in MSCs, and miR-206 can be transported into FLS through MSC-EVs to promote FLS migration and MMP3 expression and aggravate articular cartilage damage. Patients with RA who have a high IL-27 expression may not be suitable to receive treatment with MSCs, and clinicians can use MSCs that knock down or delete IL-27R to treat RA patients who have a high IL-27 expression.

Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China.

Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. We used long-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L. principis-rupprechtii Mayr. plantation from 2012-2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type and sampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P and N:P throughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:N and C:P but lower N and N:P, and the roots had greater P and C:N but lower N, C:P and N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes a valuable contribution to the global data pool on leaf nutrition and stoichiometry.