Calreticulin Regulates Neointima Formation and Collagen Deposition following Carotid Artery Ligation

Abstract

Background/Aims: The endoplasmic reticulum (ER) stress protein, calreticulin (CRT), is required for the production of TGF-β-stimulated extracellular matrix (ECM) by fibroblasts. Since TGF-β regulates vascular fibroproliferative responses and collagen deposition, we investigated the effects of CRT knockdown on vascular smooth-muscle cell (VSMC) fibroproliferative responses and collagen deposition. Methods: Using a carotid artery ligation model of vascular injury, Cre-recombinase-IRES-GFP plasmid was delivered with microbubbles (MB) to CRT-floxed mice using ultrasound (US) to specifically reduce CRT expression in the carotid artery. Results: In vitro, Cre-recombinase-mediated CRT knockdown in isolated, floxed VSMCs decreased the CRT transcript and protein, and attenuated the induction of collagen I protein in response to TGF-β. TGF-β stimulation of collagen I was partly blocked by the NFAT inhibitor 11R-VIVIT. Following carotid artery ligation, CRT staining was upregulated with enhanced expression in the neointima 14-21 days after injury. Furthermore, Cre-recombinase-IRES-GFP plasmid delivered by targeted US reduced CRT expression in the neointima of CRT-floxed mice and led to a significant reduction in neointima formation and collagen deposition. The neointimal cell number was also reduced in mice, with a local, tissue-specific knockdown of CRT. Conclusions: This work establishes a novel role for CRT in mediating VSMC responses to injury through the regulation of collagen deposition and neointima formation.

Disease-relevant single cell photonic signatures identify S100β stem cells and their myogenic progeny in vascular lesions

“…In a similar manner, photonic emissions from collagens are generally associated with hydroxylysyl-pyridinoline and lysyl-pyridinoline groups that are affected by agedependent polymerization of monomeric chains and cross links [62]. In the normal arterial wall, collagen type I and Coll 3A1 are the main collagens in the media and adventitia while arterial injury alters the balance between TGF-β1 and these two types of collagen [63][64][65].…”

“…Collagen is commonly described as extracellular, fibrous protein and its photonic emissions are generally associated with hydroxylysyl-pyridinoline and lysylpyridinoline groups that are affected by age-dependent polymerization of monomeric chains and cross links 99 . In the normal arterial wall, collagen type I and Coll 3A1 are the main collagens in the media and adventitia while arterial injury may alter the balance between these two types of collagen 106 . Indeed, enhanced Coll 3A1 expression has been specifically detected within human restenotic lesions 107 and stented coronary arteries and is accompanied by increased expression of TGF-β1 108 .…”

Thymoquinone inhibits epithelial-mesenchymal transition in prostate cancer cells by negatively regulating the TGF-β/Smad2/3 signaling pathway

“…It is reported that TGF-β may participate in the regulation of collagen (22), fibronectin (23), laminin (24) and MMP-9 (25), to affect migratory and invasive capacity. Accumulating evidence shows that Chinese herbal medicines, such as curcumin and anthocyanidins, reverse EMT and suppress metastasis via the downregulation of the TGF-β/Smad2/3 signaling pathway (26,27).…”

ADAM17 promotes epithelial-mesenchymal transition via TGF-β/Smad pathway in gastric carcinoma cells

“…It has been reported firmly that TGF-β signaling pathway plays crucial roles in regulating malignancy initiation, progression and metastasis, including gastric cancer (26). The effects of TGF-β on migration and invasion are associated with changes in ECM components, including collagen (27), fibronectin (28), laminin (29), MMP-2 and MMP-9 (30,31). ADAM17 is also involved in proteolytical digestion of collagen IV of the ECM and the release from the cell surface of several integral proteins, which suggest that ADAM17 affects the invasive activity of a variety of cancers (32,33).…”