Effect of autophagy inhibition on prognoses of rats with severe traumatic brain injury
10.3760/cma.j.cn115354-20240318-00169
- VernacularTitle:抑制自噬对重型创伤性颅脑损伤大鼠预后的影响
- Author:
Zhaomeng WEN
1
;
Yuwei SHI
;
Wenhu LIU
;
Shaobo MA
;
Jian ZHANG
;
Jianxiong LIU
;
Jin LIANG
Author Information
1. 甘肃中医药大学第一临床医学院，兰州 730000
- Keywords:
Traumatic brain injury;
Ubiquitin proteasome system;
Autophagy;
Apoptosis
- From:
Chinese Journal of Neuromedicine
2024;23(5):433-442
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the activation of ubiquitin proteasome system (UPS) and autophagy in brain tissues of rats after severe traumatic brain injury (sTBI) and the role of autophagy in secondary traumatic brain injury.Methods:(1) Twenty-five SD rats were randomly divided into sham-operated group, group of 3 h after sTBI, group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI ( n=5). Only bone window was opened in sham-operated group, and controlled cortical impact (CCI)-induced sTBI models were established in the other 4 groups. Western blotting was used to detect the expressions of free ubiquitin, ubiquitinated protein, vacuolar protein sorting 34 (VPS34), P62, microtubule-associated protein-light chain 3-II, and Mature-cathepsin D (CTSD). (2) One hundred SD rats were randomly divided into normal control group, sTBI group, lactacystin group and SAR405 group ( n=25). Ten μL lactacystin or SAR405 were stereotactically injected into the lateral ventricle of lactacystin group and SAR405 group, respectively; 30 min after that, CCI-induced sTBI models were established in the sTBI group, lactacystin group and SAR405 group. Three d after modeling, the expressions of ubiquitinated protein, LC3-II, P62, and Caspase-3 were detected by Western blotting; percentage of brain water content was determined by dry/wet weight ratio; neurological functions were assessed by modified neurological deficit scale (mNSS); degrees of brain tissue damage were detected by HE staining; and cerebral blood perfusion was detected by laser scattering hemodynamic imaging system. Results:(1) Compared with sham-operated group, group of 3 h after sTBI, group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly decreased free ubiquitin, and group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly increased ubiquitinated protein in the brain tissues surrounding the injury lesions ( P<0.05). Compared with sham-operated group, group of 3 d after sTBI and group of 7 d after sTBI had statistically increased VPS34 and Mature-CTSD and significantly decreased P62 and group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly increased LC3-II in the brain tissues surrounding the injury lesions ( P<0.05). (2) The ubiquitinated protein relative expressions in the brain tissues surrounding the injury lesions of normal control group, sTBI group, lactacystin group and SAR405 group were 4.78±2.63, 10.62±0.73, 13.45±1.22 and 8.50±0.83, respectively, with significant differences ( P<0.05). Compared with the normal control group, the sTBI group, lactacystin group and SAR405 group had significantly higher LC3-II, ubiquitinated protein and cleaved caspase-3/pro-caspase-3, and significantly lower P62 in the brain tissues surrounding the injury lesions ( P<0.05); compared with the the sTBI group, the lactacystin group had significantly higher LC3-II, ubiquitinated protein, and cleaved caspase-3/pro-caspase-3, and significantly lower P62 in the brain tissues surrounding the injury lesions ( P<0.05); compared with the the sTBI group, the SAR405 group had significantly lower LC3-II, ubiquitinated protein and cleaved caspase-3/pro-caspase-3, and significantly higher P62 in the brain tissues surrounding the injury lesions ( P<0.05). Compared with the normal control group([67.60±2.51]%、[0±0] scores、[333.41±46.86] PU), the sTBI group, lactacystin group and SAR405 group had statistically higher percentage of brain water content and mNSS scores ([80.2±1.30]%, [87.0±1.58]% and [71.60±1.81]%; 13.8±1.10, 16.4±0.55 and 10.40±1.14) and signficantly lower cerebral blood perfusion volume ([53.98±5.99] PU, [21.71±2.62] PU and [87.97±6.75] PU, P<0.05); compared with the sTBI group, the lactacystin group had significantly higher brain water content and mNSS scores, and significantly lower cerebral blood perfusion volume ( P<0.05); compared with the sTBI group, the SAR405 group had significantly lower brain water content and mNSS scores, and significantly higher cerebral blood perfusion volume ( P<0.05). HE staining showed that the cortical tissues were most severely damaged in the lactacystin group, followed by the sTBI group; the least damage was noted in the SAR405 group, and no significant damage in the normal control group was noted. Conclusion:After sTBI, UPS activation is earlier than autophagy; autophagy inhibition helps to alleviate UPS dysfunction, reduce Caspase-3-induced apoptosis, and is beneficial to the recovery of neurological function.
