Collectively, these results suggest that intrathecal injection of hUMSCs overexpressing HO-1 can significantly promote functional outcomes in cystitis rats by reducing neuroinflammation, at least, partly through downregulating TLR4/p65/NLRP3 pathway in the SDH region of CYP-induced cystitis rats. Here, NLRP3 is linked to chronic cystitis.