[Effect of polysaccharides from seeds of Vaccaria segetalis in alleviating urinary tract infection induced bladder injury by inhibiting NLRP3 inflammasome].

To study the mechanism of polysaccharides from seeds of Vaccaria segetalis( PSV) in the treatment of bacterial cystitis through the NLRP3 inflammasome pathway. The rat model of urinary tract infection was used and treated with PSV,and the urine and bladders were collected. The level of interleukin-10( IL-10) in rat urine was detected by enzyme linked immunosorbent assay( ELISA). Western blot and immunofluorescence staining were used to detect the expressions of sonic hedgehog( SHH) and NLRP3 inflammasome [NOD-like receptor thermoprotein domain 3( NLRP3),apoptosis associated speck like protein( ASC) and pro-caspase-1]. The expression of Toll-like receptor pathway was detected by RT-PCR. The death of 5637 cells induced by uropathogenic Escherichia coli( UPEC) and lactate dehydrogenase( LDH) release were evaluated using live/dead staining. The results showed that in the rat bladder,the expressions of SHH,NLRP3 inflammasomes and Toll-like receptors were significantly up-regulated,and NLRP3 inflammasomes were significantly activated by UPEC infection. The administration with PSV could significantly increase the concentration of IL-10 in urine,inhibit the expressions of SHH,NLRP3 inflammasomes and Toll-like receptors in bladder,and inhibit the activation of NLRP3 inflammasomes. A large number of 5637 cells were dead after UPEC infection and caused LDH production. PSV could significantly inhibit the death of 5637 cells and the release of LDH. In conclusion,PSV could inhibit the expression and activation of NLRP3 inflammasomes by inhibiting the Toll-like receptor pathway,thereby mitigating the bladder injury.