Aortic dissection is one of the most devastating cardiovascular diseases. One of the most important pathological features of aortic dissection is local inflammatory response, including the infiltration of inflammatory cells, extracellular matrix degradation, and smooth muscle cell phenotype switch. Macrophages which are the core of the inflammatory response play an extremely pivotal role in the progression of inflammation and tissue remodeling. Macrophages can be artificially divided into M1 and M2 types, of which the M1-type promotes inflammation while the M2-type is associated with the regression of inflammation and tissue healing. Mastering the switch of phenotypic transformation of macrophages may be of great help in inhibiting the inflammation of aortic tissue and facilitating tissue healing, as well as the treatment of aortic dissection. In this paper, we focus on the polarization of macrophages and discuss the role of macrophages in aortic dissection, the polarization pathway and the effect of related polarizing agents on the treatment of aortic dissection.
Abdominal aortic aneurysm (AAA) is a common lethal aortic disease in clinical practice. At present, the imaging diagnostic methods used for AAA mainly include Doppler ultrasound, computed tomography and magnetic resonance imaging (MRI), but these methods can only observe the morphological changes of the aorta. These techniques used for the risk assessment of aneurysms, such as aneurysm rupture have some certain limitations. With the continuous development of molecular imaging technology and the further understanding of the pathogenesis of AAA, positron emission tomography (PET), molecular MRI and single photon emission computed tomography (SPECT) techniques can be used to observe the pathological changes of the AAA and assess the risk of rupture from cell and molecular level. In this paper, the latest application of PET, molecular MRI, SPECT in the risk assessment was discussed.
Objective To study the inhibitory effect of RNA interference (RNAi) on bcl-2 expression of vascular smooth muscle cells （VSMCs) in rabbit. Methods The expression vector of bcl-2 gene-targeting small interference RNA (pshRNA-bcl-2) was constructed and was transfected into VSMCs by lipofectamine, and the unloaded vector was used as control. The expression of bcl-2 mRNA was identified by RT-PCR and Western blot, respectively. The growth of the transfected VSMCs was examined by MTT. Results The pshRNA-bcl-2 may inhibit the expression of bcl-2 gene at the levels of transcription and translation. There were significant differences (P＜0.01) of the expressions of bcl-2 mRNA between the VSMCs that were transfected with pshRNA-bcl-2 and the ones in plasmid transfected group and control group, respectively. There was a significant difference (P＜0.01) in the growth of VSMCs between the plasmid transfected and the control groups. Conclusion The plasmid containing the small interference RNA of bcl-2 may have an inhibitory effect on the cell growth and endogenous expression of bcl-2 gene at the levels of transcription and translation in VSMCs.
Objective To investigate the effect of TIMP-2 gene that was transfected by adenovirus on extracellular matrix of abdominal aortic through assessing the changes of morphology and histopathology of the rat models with abdominal aortic aneurysm. Methods The rat models with abdominal aortic aneurysm were constructed by intraluminally perfusing porcine pancreatic elastase. Twenty-four SD rats with aneurysm were then randomly divided into 3 groups: AdTIMP-2 group (perfused locally with solution of TIMP-2 gene transfected by adenovirus vector to abdominal aorta), AdCMV group (transfected by non-viral vector), and PBS group. After 14 days, the concentrations of elastin and collagen that were collected from the samples of aortic wall were measured by image analysis system and the fixed aortic tissues were examined by light microscopy and some other specific staining methods. Results None of abdominal aortic aneurysm developed in TIMP-2 gene transfected group, with significantly higher rates of developed aneurysm in the other groups (P＜0.01). The diameters of arteries on day 14 in the AdTIMP-2 group were (2.33±0.06) mm, which were significantly smaller than those in the AdCMV group 〔（3.52±0.11） mm〕 and PBS group 〔（3.43±0.09） mm〕. The elastic fibers and collagenous fibers were preserved with more integrity in AdTIMP-2 group and inflammation cells that were observed in adventitia of artery were also less than those of the other groups. Conclusion TIMP-2 gene transfected by adenovirus vector could restore the degradation of extracellular matrix that was aroused by elastase and could block the formation of abdominal aortic aneurysm, which may provide a new strategy for the treatment of abdominal aortic aneurysm.