cathepsin-g and Carotid-Artery-Diseases

Subendothelial interaction of LDL with extracellular matrix drives atherogenesis. This interaction can be strengthened by proteolytic modification of LDL. Mast cells (MCs) are present in atherosclerotic lesions, and upon activation, they degranulate and release a variety of neutral proteases. Here we studied the ability of MC proteases to cleave apoB-100 of LDL and affect the binding of LDL to proteoglycans.. Mature human MCs were differentiated from human peripheral blood-derived CD34. Activated human MCs released the neutral proteases tryptase, chymase, carboxypeptidase A3, cathepsin G, and granzyme B. Of these, cathepsin G degraded most efficiently apoB-100, induced LDL fusion, and enhanced binding of LDL to isolated human aortic proteoglycans and human atherosclerotic lesions ex vivo. Double immunofluoresence staining of human atherosclerotic coronary arteries for tryptase and cathepsin G indicated that lesional MCs contain cathepsin G. In the lesions, expression of cathepsin G correlated with the expression of tryptase and chymase, but not with that of neutrophil proteinase 3.. The present study suggests that cathepsin G in human atherosclerotic lesions is largely derived from MCs and that activated MCs may contribute to atherogenesis by enhancing LDL retention.

Topics: Apolipoprotein B-100; Atherosclerosis; Carotid Artery Diseases; Cathepsin G; Cell Degranulation; Cells, Cultured; Coronary Artery Disease; Enzyme Activation; Humans; Lipoproteins, LDL; Mast Cells; Plaque, Atherosclerotic; Protein Binding; Proteoglycans; Proteolysis

The aim was to investigate the expression of genes associated with carotid plaque instability and their protein products at a local and systemic level.. Carotid plaques from 24 patients undergoing carotid endarterectomy (CEA) were classified as stable or unstable using clinical, histological, ultrasound, and transcranial Doppler criteria, and compared using whole genome microarray chips. Initial results of differentially expressed genes were validated by quantitative reverse transcriptase polymerase chain reaction in an independent group of 96 patients undergoing CEA. The protein product of genes significantly differentially expressed between patients with stable and unstable plaques were analysed by plaque immunohistochemistry and serum protein quantification by enzyme-linked immunosorbent assay on a further independent cohort.. Expression of chemokine (c-c-motif) ligand 19 (CCL19) was significantly upregulated in plaques from patients with clinically unstable disease (p < .001). Cathepsin G expression was upregulated in histologically unstable plaques (p = .04). Serum concentration of CCL19 was significantly higher in patients with clinically unstable plaques (p = .02). Immunohistochemical staining for CCL19 demonstrated positive staining in histologically and clinically unstable plaques (p = .03). CCL19 also co-localised with CD3. CCL19 is significantly overexpressed in patients with unstable carotid atherosclerotic plaques and may be a possible novel biomarker for identifying high-risk patients in whom more urgent intervention may be indicated.

Topics: Carotid Arteries; Carotid Artery Diseases; Cathepsin G; Chemokine CCL19; Endarterectomy, Carotid; Gene Expression; Genetic Markers; Humans; Prognosis; Protein Array Analysis; Up-Regulation

Topics: Angiotensin II; Angiotensinogen; Carotid Artery Diseases; Carotid Artery, Common; Cathepsin D; Cathepsin G; Cathepsins; Humans; Peptidyl-Dipeptidase A; Receptor, Angiotensin, Type 1; RNA, Messenger; Serine Endopeptidases

To elucidate the organization of the tissue angiotensin system, we investigated the expression and cellular localization of angiotensin system components and cathepsins D and G, potentially involved in intraparietal angiotensin II formation and atheroma.. Total RNA was extracted from atheroma plaque, fatty streaks and macroscopically intact tissue obtained during carotid endarterectomy in 21 hypertensive patients. mRNA levels were compared between these tissues using a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In situ hybridization and immunohistochemistry were used to define the cellular localization of the transcripts and their respective proteins.. Apart from renin and angiotensin type 2 (AT2) receptors, which were never detected, the studied mRNAs could be measured in all patients. Angiotensin-converting enzyme (ACE) mRNA was increased five-fold in atheroma, and angiotensin type 1 receptor (AT1) mRNA decreased 2.5-fold in atheroma and 1.4-fold in fatty streaks compared to intact tissue. A two-fold increase in cathepsin G mRNA was observed in atheroma plaque. In atheroma and intact tissue, significant positive correlations were found between cathepsin G and angiotensinogen, AT1 receptor and ACE mRNAs. Angiotensinogen and cathepsin mRNAs and proteins were detected in both arterial layers. AT1 immunoreactivity was mainly associated with alpha-actin-positive cells.. All components required for angiotensin II formation are expressed locally in the arterial wall, where, in the absence of renin, cathepsin G could be a major angiotensin-generating enzyme. Overexpression of ACE and cathepsin G may lead to angiotensin II overproduction and contribute, with decreased number of differentiated smooth muscle cells, to the lower amount of AT1 receptor in atheroma.

Topics: Aged; Aged, 80 and over; Angiotensinogen; Carotid Artery Diseases; Carotid Artery, Common; Cathepsin D; Cathepsin G; Cathepsins; Endarterectomy, Carotid; Female; France; Gene Expression; Humans; Immunohistochemistry; Male; Middle Aged; Peptidyl-Dipeptidase A; Receptor, Angiotensin, Type 1; RNA, Messenger; Serine Endopeptidases; Severity of Illness Index; Statistics as Topic; Treatment Outcome; Tunica Intima