MiR-9-enriched mesenchymal stem cells derived exosomes prevent cystitis-induced bladder pain via suppressing TLR4/NLRP3 pathway in interstitial cystitis mice.

BACKGROUND: Inflammatory response of central nervous system is an important component mechanism in the bladder pain of interstitial cystitis/bladder pain syndrome (IC/BPS). Exosomes transfer with microRNAs (miRNA) from mesenchymal stem cell (MSCs) might inhibit inflammatory injury of the central nervous system. Herein, the purpose of our study was to explore the therapeutic effects by which extracellular vesicles （EVs） derived from miR-9-edreched MSCs in IC/BPS and further investigate the potential mechanism to attenuate neuroinflammation.

METHODS: On the basis of IC/BPS model, we used various techniques including bioinformatics, cell and molecular biology, and experimental zoology, to elucidate the role and molecular mechanism of TLR4 in regulating the activation of NLRP3 inflammasome in bladder pain of IC/BPS, and investigate the mechanism and feasibility of MSC-EVs enriched with miR-9 in the treatment of bladder pain of IC/BPS.

RESULTS: The inflammatory responses in systemic and central derived by TLR4 activation were closely related to the cystitis-induced pelvic/bladder nociception in IC/BPS model. Intrathecal injection of miR-9-enreched MSCs derived exosomes were effective in the treatment of cystitis-induced pelvic/bladder nociception by inhibiting TLR4/NF-κb/NLRP3 signal pathway in central nervous system of IC/BPS mice.

CONCLUSIONS: This study demonstrated that miR-9-enreched MSCs derived exosomes alleviate neuroinflammaiton and cystitis-induced bladder pain by inhibiting TLR4/NF-κb/NLRP3 signal pathway in interstitial cystitis mice, which is a promising strategy against cystitis-induced bladder pain.