Title : Nano modification of Antrodia cinnamomea exhibit anti-inflammatory action and improves the migratory potential of myogenic progenitors
Skeletal myogenesis involves the formation of new skeletal muscular tissue. During an injury, the skeletal muscle stem cells known as the satellite cells get activated and undergo proliferation, migration, and differentiation to complete the process of myogenesis. Muscle wasting is an extra-intestinal manifestation of inflammatory bowel diseases (IBD) caused by impaired myogenesis. In our study, we provide evidence that beta-cyclodextrin complexation of Antrodia cinnamomea (AC) extracts results in improved proliferation and migratory potential of murine C2C12 myoblast cells in-vitro.
The solid inclusion complex (IC) formed between AC and beta-cyclodextrin by co-evaporation method was characterized using SEM, TEM, TGA/DSC, and FT-IR analysis. The size, surface charge, and dispersity index of IC were studied using zeta potential and DLS analysis. In the solution state, the formation of IC was confirmed by water solubility analysis, UV-vis spectroscopy, and fluorescent spectrophotometry. Fluorescent IC (AO-IC) was synthesized to understand the cellular uptake time and mechanism of IC by complexing it with acridine orange. The drug uptake studies performed by flow cytometry and fluorescent microscopy on C2C12 myoblasts cells showed that 60% of the drug internalization occurred within 5 min of cellular interaction of AO-IC and maximum uptake occurred within 2 h. The internalized AO-IC concentrated majorly within the cytoplasmic region of the C2C12 myoblast cells. The cellular internalization studies performed using endocytosis inhibitors demonstrated that IC uptake occurred predominantly via the pinocytosis pathway. However, a small amount of IC has also been internalized via clathrin-dependent endocytosis. The proliferation assay indicated that lower concentrations of IC enhanced the proliferation of C2C12 myoblasts cells. The in-vitro migration studies revealed that the complexation of AC with beta-cyclodextrin improved the migration potential of C2C12 myoblasts compared to that of pure drug AC in 24 h. Further investigation on the migratory protein expression indicated that IC increased the expression of N-cadherin and beta-catenin compared to the pure drug AC. RT-PCR studies revealed that IC reversed the suppressive effect of LPS on the expression of long non-coding RNAs (lncRNAs) NEAT-1 and SYISL whereas it reduced the expression of lncRNA MEG-3. In addition, IC exhibited anti-inflammatory action by significantly reducing the IL-6 expression in LPS stimulated C2C12 myoblast cells.
In conclusion, our study provides evidence that the inclusion complex formed between beta-cyclodextrin, and AC enhanced their bioavailability and stability. The interaction of IC with C2C12 myoblast cells resulted in their uptake within 5 min via pinocytosis. Once in the cytoplasm, IC increased the expression of lncRNA NEAT-1 and SYISL and reduced the expression of lncRNA MEG-3. The lncRNA NEAT-1 enhanced the migration of C2C12 myoblasts by indirectly enhancing the expression of N-cadherin and beta-catenin. This results in improved proliferation and migration of C2C12 myoblasts cells possibly by activating Wnt/beta-catenin signaling pathway. The IC also retained the anti-inflammatory property of AC by reducing the expression of IL-6 in C2C12 myoblasts cells. Hence, IC exhibits promising properties to improve skeletal myogenesis by improving the proliferation and migration of skeletal muscle progenitor cells.