Dajun Zhao1, Yang Sun2, Xufeng Wei1, Hongliang Liang1, Lin Zhao1, Xiaochao Dong1, Hao Chen1, Wenhao Chen1, Jian Yang1, Xiaowu Wang1, Feng Gao3, Wei Yi4. 1. Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China. 2. Department of Geriatrics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China. 3. Department of Physiology, The Fourth Military Medical University, Xi'an 710032, China. 4. Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China. Electronic address: yiwei@fmmu.edu.cn.
Abstract
AIMS: Shear stress-induced apoptosis is one of the leading problems in seeding cells of tissue-engineered blood vessels (TEBVs). We aim to determine the human bone mesenchymal stem cell (hBMSC) apoptosis under shear stress and its possible mechanism. MAIN METHODS: hBMSCs were subjected to 3-, 10-, and 30-dyn/cm(2) shear stress in vitro. Cell multiplication and apoptosis were analyzed by flow cytometry. Apoptosis-related genes were screened by a microarray and evidenced by real-time polymerase chain reaction (RT-PCR). hBMSCs were treated with the human recombinant cell inhibitor of apoptosis protein 1 (cIAP1) and its inhibitor, direct IAP-binding protein with low pl (DIABLO), and then cell apoptosis was analyzed. KEY FINDINGS: Exposure to shear stress (3dyn/cm(2) for >6h) activated apoptosis progress of hBMSCs. However, the same degree of shear stress (3dyn/cm(2) for 6h) did not induce apoptosis. Microarray screening and RT-PCR revealed that Bcl-2-related ovarian killer (BOK) and apoptotic protease-activating factor 1 (APAF1), key molecules of the mitochondrial apoptosis pathway, were markedly upregulated under 3-dyn/cm(2) shear stress. Then, we observed that cIAP1, a Caspase 9 inhibitor, was elevated under 3dyn/cm(2) at short-time exposure (2 or 6h), and it was reduced at long-time exposure (24h). When treated with human recombinant cIAP1, Caspase 3 activity and LDH release of hBMSCs were decreased, and vice versa when treated with DIABLO. SIGNIFICANCE: cIAP1 attenuates hBMSC apoptosis when cells were exposed to shear stress through the regulation of the BOK-APAF1-Caspase 9-Caspase 3 pathway. It may present a pharmacological target to enhance hBMSC biological function in the application of TEBVs.
AIMS: Shear stress-induced apoptosis is one of the leading problems in seeding cells of tissue-engineered blood vessels (TEBVs). We aim to determine the human bone mesenchymal stem cell (hBMSC) apoptosis under shear stress and its possible mechanism. MAIN METHODS: hBMSCs were subjected to 3-, 10-, and 30-dyn/cm(2) shear stress in vitro. Cell multiplication and apoptosis were analyzed by flow cytometry. Apoptosis-related genes were screened by a microarray and evidenced by real-time polymerase chain reaction (RT-PCR). hBMSCs were treated with the human recombinant cell inhibitor of apoptosis protein 1 (cIAP1) and its inhibitor, direct IAP-binding protein with low pl (DIABLO), and then cell apoptosis was analyzed. KEY FINDINGS: Exposure to shear stress (3dyn/cm(2) for >6h) activated apoptosis progress of hBMSCs. However, the same degree of shear stress (3dyn/cm(2) for 6h) did not induce apoptosis. Microarray screening and RT-PCR revealed that Bcl-2-related ovarian killer (BOK) and apoptotic protease-activating factor 1 (APAF1), key molecules of the mitochondrial apoptosis pathway, were markedly upregulated under 3-dyn/cm(2) shear stress. Then, we observed that cIAP1, a Caspase 9 inhibitor, was elevated under 3dyn/cm(2) at short-time exposure (2 or 6h), and it was reduced at long-time exposure (24h). When treated with human recombinant cIAP1, Caspase 3 activity and LDH release of hBMSCs were decreased, and vice versa when treated with DIABLO. SIGNIFICANCE: cIAP1 attenuates hBMSC apoptosis when cells were exposed to shear stress through the regulation of the BOK-APAF1-Caspase 9-Caspase 3 pathway. It may present a pharmacological target to enhance hBMSC biological function in the application of TEBVs.