MicroRNA‐23a‐5p Is Involved in the Regulation of Lipopolysaccharide‐Induced Acute Lung Injury by Targeting HSP20/ASK1

Abstract

Inflammation and oxidative stress contribute to the progression of acute lung injury (ALI). MicroRNA-23a-5p (miR-23a-5p) has been reported to regulate inflammation and oxidative stress; however, its role in ALI is still poorly elucidated. Mice were intravenously treated with the miR-23a-5p antagomir, agomir, or the negative controls for 3 consecutive days and then received a single intratracheal injection of lipopolysaccharide (LPS, 5 mg/kg) to induce ALI. Pulmonary function, bronchoalveolar lavage fluids (BALFs), arterial blood gas, and molecular biomarkers associated with inflammation and oxidative stress were analyzed. In addition, murine peritoneal macrophages were isolated and treated with LPS to verify the role of miR-23a-5p in vitro. We detected an elevation of miR-23a-5p expression in the lungs from ALI mice. The miR-23a-5p antagomir was prevented, whereas the miR-23a-5p agomir aggravated inflammation, oxidative stress, lung tissue injury, and pulmonary dysfunction in LPS-treated mice. Besides, the miR-23a-5p antagomir also reduced the productions of proinflammatory cytokines and free radicals in LPS-treated primary macrophages, which were further augmented in cells following the miR-23a-5p agomir treatment. Additional findings demonstrated that the miR-23a-5p agomir exacerbated LPS-induced ALI via activating apoptosis signal-regulating kinase 1 (ASK1), and that pharmacological or genetic inhibition of ASK1 significantly repressed the deleterious effects of the miR-23a-5p agomir. Moreover, we proved that the miR-23a-5p agomir activated ASK1 via directly reducing heat shock protein 20 (HSP20) expression. miR-23a-5p is involved in the regulation of LPS-induced inflammation, oxidative stress, lung tissue injury, and pulmonary dysfunction by targeting HSP20/ASK1, and it is a valuable therapeutic candidate for the treatment of ALI.

MicroRNA-1224-5p Aggravates Sepsis-Related Acute Lung Injury in Mice

“…Bacterial pneumonia is a common cause of sepsis-related ALI, and LPS is the major virulence factor in the outer membrane of Gram-negative bacteria and is well-accepted to generate sepsis-related organ injury in mice. In the present study, one hundred and two male C57BL/6 mice aged 10-12-weeks old received a single intratracheal injection of LPS (5 mg/kg) and then maintained for 12 h to establish sepsis-related ALI as we previously described, while mice with saline injection were used as the control [ 19 , 26 ]. To manipulate miR-1224-5p level, mice were intravenously injected with the agomir (30 mg/kg/day), antagomir (80 mg/kg/day), or matched controls for 3 consecutive days before LPS injection [ 19 , 26 ].…”

“…In the present study, one hundred and two male C57BL/6 mice aged 10-12-weeks old received a single intratracheal injection of LPS (5 mg/kg) and then maintained for 12 h to establish sepsis-related ALI as we previously described, while mice with saline injection were used as the control [ 19 , 26 ]. To manipulate miR-1224-5p level, mice were intravenously injected with the agomir (30 mg/kg/day), antagomir (80 mg/kg/day), or matched controls for 3 consecutive days before LPS injection [ 19 , 26 ]. To investigate the role of miR-1224-5p in mortality rate, mice were injected from the trachea with a lethal dose of LPS (25 mg/kg) and monitored every 12 h [ 19 ].…”

“…Pulmonary function was determined using the Buxco pulmonary function testing system (Connecticut, CT, USA) as previously described [ 26 , 29 ]. Airway resistance, pulmonary ventilation, lung compliance, tidal volume, and respiratory rate (RR) were recorded from the anesthetized mice.…”

“…Lung wet to dry ratio was calculated to evaluate pulmonary edema as we previously described [ 19 , 26 ]. In brief, fresh lungs were excised and weighed to obtain the wet weight, which were then placed at 80°C for 96 h to get the constant dry weight.…”

HDAC3 promotes macrophage pyroptosis via regulating histone deacetylation in acute lung injury

“…To induce pyroptosis in macrophages, the cells were stimulated with LPS (1 μg/mL) for 4 hours, followed with the incubation with nigericin (10 µM) for 0.5 hour [25]. The THP-1 cells were transfected with miR-4767 antagomir (50 nmol/L), agomir (50 nmol/L), or the negative controls synthesized by Ribobio Inc. (Guangzhou, China) using Lipofectamine™ 3000 Transfection Reagent as described [26].…”