MicroRNA-148a-3p is a candidate mediator of increased bone marrow adiposity and bone loss following spinal cord injury

Complanatuside A improves functional recovery after spinal cord injury through inhibiting JNK signaling-mediated microglial activation

BACKGROUND AND AIMS

Complanatuside A (ComA) is a flavonoid-rich compound in Astragalus membranaceus that has anti-inflammatory and neuroprotective effects. In this study, we focused on the effect of ComA on spinal cord injury (SCI) in mice and explored its possible mechanisms.

METHODS

The SCI model was constructed using C57BL/6J mice, and the effect of ComA on motor function recovery in SCI mice was evaluated through the BMS (Basso Mouse Scale) and footprint test. The histological effects of ComA on SCI mice were evaluated by hematoxylin-eosin (H&E) staining, Luxol-fast blue (LFB) staining, and Nissl staining. In both in vivo and in vitro experiments, we detected the activation of microglia and the release of inflammatory factors through molecular experiments. Immunofluorescence and Western blotting confirmed that ComA can prevent neuronal apoptosis caused by activated microglia through the c-Jun N-terminal kinase (JNK) pathway.

RESULTS

Our research results confirm that ComA can improve motor function in mice after SCI. Our in vitro results indicate that ComA can inhibit the activation of BV2 cells and the release of proinflammatory mediators. In addition, ComA can prevent neuronal cell apoptosis caused by activated BV2 cells. Finally, we found that ComA works through the JNK signaling pathway.

CONCLUSIONS

ComA can accelerate the restoration of motor function in mice after SCI, possibly by reducing neuronal apoptosis via inhibition of JNK-related signaling pathways, a reduction in microglial activation, and inhibition of inflammatory factor release. Our data indicate that ComA is a promising drug candidate for improving functional recovery in patients with SCI.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.