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No induced apoptosis accompanying the change of oncoprotein expression and the activation of CPP32 protease
1Department of Pharmacology, National Defense Medical College, Tokorozawa, Saitama, Japan.
Abstract:
Previously we have shown that nitric oxide (NO) donors induced apoptosis in vascular smooth muscle cells (VSMCs). However, the mechanisms by which NO induced apoptosis in VSMCs are entirely unknown. In the present study, we intended to identify the mechanism by which NO donors induce apoptosis in VSMCs. First, we evaluated the expression of c-Myc, P53, and Bcl-2 proteins in VSMCs treated by NO donors. c-Myc and P53 protein expression increased after VSMCs were incubated with NO donors for 6 hr and reached a maximum level at 24 hr, while Bcl-2 protein decreased after 12 hr incubation. Next we investigated to see whether the CPP32 protease activation was involved in NO donors-induced apoptosis. In VSMCs treated by NO donors, the increase of CPP32 protease activity was observed and specific inhibition of CPP32 activity significantly prevented apoptosis induced by NO donors in a dose-dependent manner. These results suggest that NO donors induced apoptosis through proto-oncoprotein expression and CPP32-like protease activation.
Insights
Nitric oxide (NO) donors trigger vascular smooth muscle cell (VSMC) apoptosis by increasing proto-oncoprotein expression and activating CPP32-like proteases. This research uncovers key mechanisms in NO-induced cell death.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Nitric oxide (NO) is known to induce apoptosis in vascular smooth muscle cells (VSMCs).
- The precise molecular mechanisms underlying NO-induced apoptosis in VSMCs remain largely unelucidated.
Purpose of the Study:
- To identify the specific molecular pathways through which NO donors induce apoptosis in VSMCs.
- To investigate the roles of c-Myc, P53, Bcl-2 proteins, and CPP32 protease activity in this process.
Main Methods:
- VSMCs were treated with NO donors.
- Expression levels of c-Myc, P53, and Bcl-2 proteins were evaluated using Western blotting or similar techniques.
- CPP32 protease activity was measured, and its inhibition was assessed for its effect on apoptosis.
Main Results:
- NO donors significantly increased the expression of c-Myc and P53 proteins in VSMCs.
- Bcl-2 protein expression decreased following NO donor treatment.
- CPP32 protease activity increased in VSMCs treated with NO donors, and its inhibition dose-dependently prevented apoptosis.
Conclusions:
- NO donors induce apoptosis in VSMCs via the upregulation of proto-oncoproteins (c-Myc, P53) and activation of CPP32-like proteases.
- These findings elucidate critical molecular events in NO-mediated VSMC apoptosis.