Role of cathepsin B in mechanical ventilator-induced lung injury in rats: relationship with NLRP3 inflammasomes
10.3760/cma.j.cn131073.20220218.00421
- VernacularTitle:组织蛋白酶B在大鼠呼吸机相关性肺损伤中的作用：与NLRP3炎症小体的关系
- Author:
Jiangxiao CAI
1
;
Li CONG
;
Boxi LIU
;
Weiwei QIN
;
Fuguo MA
;
Lixin SUN
;
Wei HAN
Author Information
1. 青岛大学附属青岛市市立医院麻醉科 266071
- Keywords:
Cathepsin B;
Ventilator-induced lung injury;
NLR Family, pyrin domain-containing 3 protein
- From:
Chinese Journal of Anesthesiology
2022;42(4):475-480
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the role of cathepsin B (CTSB) in mechanical ventilator-induced lung injury (VILI) in rats and the relationship with NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome.Methods:Thirty-six SPF-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 220-300 g, were divided into 3 groups ( n=12 each) by the random number table method: control group (group C), VILI group (group V) and VILI + CA074-me group (group Me). CA074-me 5 mg/kg was intraperitoneally injected in group Me, while the equal volume of normal saline was given instead in group C and group V. Group C kept spontaneous breathing for 4 h, and the animals were mechanically ventilated (tidal volume 20 ml/kg, respiratory rate 80 breaths/min, fraction of inspired oxygen 21%, PEEP 0 cmH 2O). Blood samples from femoral artery were collected for arterial blood gas analysis before tracheal intubation and after spontaneous breathing or ventilation, and PaO 2 was recorded.Rats were sacrificed, and bronchoalveolar lavage fluid (BALF) was collected and lung tissues were collected for determination of the wet/dry lung weight ratio (W/D ratio), serum interleukin-1beta (IL-1β) and IL-18 concentrations in BALF (by enzyme-linked immunosorbent assay), expression of CTSB, NLRP3, apoptosis-associated speck-like protein containing a caspase-1 recruitment domain (ASC) and caspase-1 mRNA in lung tissues (quantitative real-time polymerase chain reaction), and expression of CTSB, NLRP3, ASC and caspase-1 in lung tissues (by Western blot) and for microscopic examination of the pathological changes (using HE staining). Lung injury was assessed and scored. Results:Compared with group C, PaO 2 was significantly decreased after the end of ventilation, the lung injury score, W/D ratio and concentrations of IL-1β and IL-18 in serum and BALF were increased, and the expression of CTSB, NLRP3, ASC and caspase-1 protein and mRNA in lung tissues was up-regulated in group V and group Me ( P<0.01). Compared with group V, PaO 2 was significantly increased after the end of ventilation, the lung injury score, W/D ratio and concentrations of IL-1β and IL-18 in serum and BALF were decreased, and the expression of CTSB, NLRP3, ASC and caspase-1 protein and mRNA in lung tissues was down-regulated in group Me ( P<0.01). Conclusions:CTSB is involved in VILI in the rats, and the mechanism may be related to activation of NLRP3 inflammasomes.
