Chen Meng1, Silu Wang2, Xue Wang3, Jing Lv4, Wenjing Zeng5, Ruijie Chang6, Qing Li7, Xianyu Wang8. 1. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: 27739865@qq.com. 2. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: 514977213@qq.com. 3. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: 754337370@qq.com. 4. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: roylvjing@163.com. 5. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: 99220532@qq.com. 6. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: 1297432533@qq.com. 7. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: Liqing8801@163.com. 8. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Institute of Anesthesiology, Hubei University of Medicine, Shiyan, 442000, Hubei, China. Electronic address: wxytj@126.com.
Abstract
BACKGROUND: We previously observed that amphiregulin (Areg), a ligand of epithelial growth factor receptor (EGFR), was highly expressed in lipopolysaccharide (LPS)-induced acute lung injury (ALI) lung tissues mainly by the classically activated (M1) alveolar macrophages (AMs). Areg also plays a protective role in LPS-induced injury in lung tissues and alveolar epithelial cells (AECs). However, whether Areg is co-expressed with tumor necrosis factor (TNF)-α in ALI lung tissues, and can directly inhibit TNF-α-induced AEC injury remains unclear. METHODS: We first detected the kinetic expressions of Areg and TNF-α in LPS-stimulated lung tissues and M1 AMs and then identified the role of exogenous recombinant Areg (rmAreg) in the injured lung tissues. The effect of Areg on TNF-α-induced apoptosis in MLE-12 cells, a kind of AECs, was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The activation of the EGFR-AKT pathway and caspase-3, -8, and -9 were detected by Western blotting. The EGFR knockdown by small interfering RNA was used to assess the role of EGFR in Areg functions. RESULTS: Areg production occurred in close parallel with TNF-α expression in M1 AMs and ALI lung tissues, and rmAreg attenuated LPS-induced ALI in mice. TNF-α stimulation induced significant apoptosis in MLE-12 cells, but this apoptosis was inhibited under rmAreg treatment. Moreover, rmAreg enhanced the activation of EGFR and AKT, and reduced the expressions of cleaved caspase-3, -8, and -9 in ALI lung tissues and TNF-α-challenged MLE-12 cells. However, the EGFR knockdown significantly inhibited the Areg-induced improvement in apoptosis, enhancement of EGFR and AKT activation, and reduction of cleaved caspase-3, -8, and -9 expressions. CONCLUSIONS: Areg and TNF-α were synchronously produced by ALI lung tissues and M1 AMs, and Areg directly inhibited the TNF-induced apoptosis and transduction of caspase death signals in AECs via the EGFR pathway.
BACKGROUND: We previously observed that amphiregulin (Areg), a ligand of epithelial growth factor receptor (EGFR), was highly expressed in lipopolysaccharide (LPS)-induced acute lung injury (ALI) lung tissues mainly by the classically activated (M1) alveolar macrophages (AMs). Areg also plays a protective role in LPS-induced injury in lung tissues and alveolar epithelial cells (AECs). However, whether Areg is co-expressed with tumor necrosis factor (TNF)-α in ALI lung tissues, and can directly inhibit TNF-α-induced AEC injury remains unclear. METHODS: We first detected the kinetic expressions of Areg and TNF-α in LPS-stimulated lung tissues and M1 AMs and then identified the role of exogenous recombinant Areg (rmAreg) in the injured lung tissues. The effect of Areg on TNF-α-induced apoptosis in MLE-12 cells, a kind of AECs, was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The activation of the EGFR-AKT pathway and caspase-3, -8, and -9 were detected by Western blotting. The EGFR knockdown by small interfering RNA was used to assess the role of EGFR in Areg functions. RESULTS:Areg production occurred in close parallel with TNF-α expression in M1 AMs and ALI lung tissues, and rmAreg attenuated LPS-induced ALI in mice. TNF-α stimulation induced significant apoptosis in MLE-12 cells, but this apoptosis was inhibited under rmAreg treatment. Moreover, rmAreg enhanced the activation of EGFR and AKT, and reduced the expressions of cleaved caspase-3, -8, and -9 in ALI lung tissues and TNF-α-challenged MLE-12 cells. However, the EGFR knockdown significantly inhibited the Areg-induced improvement in apoptosis, enhancement of EGFR and AKT activation, and reduction of cleaved caspase-3, -8, and -9 expressions. CONCLUSIONS:Areg and TNF-α were synchronously produced by ALI lung tissues and M1 AMs, and Areg directly inhibited the TNF-induced apoptosis and transduction of caspase death signals in AECs via the EGFR pathway.
Authors: Jonathan Florentin; Jingsi Zhao; Yi-Yin Tai; Wei Sun; Lee L Ohayon; Scott P O'Neil; Anagha Arunkumar; Xinyi Zhang; Jianhui Zhu; Yassmin Al Aaraj; Annie Watson; John Sembrat; Mauricio Rojas; Stephen Y Chan; Partha Dutta Journal: Life Sci Alliance Date: 2022-06-22