Attenuation of proliferation and migration of retinal pericytes in the absence of thrombospondin-1

Abstract

Scheef EA, Sorenson CM, Sheibani N. Attenuation of proliferation and migration of retinal pericytes in the absence of thrombospondin-1. Am J Physiol Cell Physiol 296: C724 -C734, 2009. First published February 4, 2009 doi:10.1152/ajpcell.00409.2008.-Perivascular supporting cells, including vascular smooth muscle cells (VSMCs) and pericytes (PCs), provide instructive signals to adjacent endothelial cells helping to maintain vascular homeostasis. These signals are provided through direct contact and by the release of soluble factors by these cells. Thrombospondin (TSP)1 is a matricellular protein and an autocrine factor for VSMCs. TSP1 activity, along with that of PDGF, regulates VSMC proliferation and migration. However, the manner in which TSP1 and PDGF impact retinal PC function requires further investigation. In the present study, we describe, for the first time, the isolation and culture of retinal PCs from wild-type (TSP1 ϩ/ϩ ) and TSP1-deficient (TSP1 Ϫ/Ϫ ) immortomice. We showed that these cells express early and mature markers of PCs, including NG2, PDGF receptor-␤, and smooth muscle actin as well as desmin, calbindin, and mesenchymal stem cell markers. These cells were successfully passaged and maintained in culture for several months without significant loss of expression of these markers. TSP1 ϩ/ϩ PCs proliferated at a faster rate compared with TSP1PCs. In addition, TSP1 ϩ/ϩ PCs, like VSMCs, responded to PDGF-BB with enhanced migration and proliferation. In contrast, TSP1Ϫ/Ϫ PCs failed to respond to the promigratory and proliferative activity of PDGF-BB. This may be attributed, at least in part, to the limited interaction of PDGF-BB with TSP1 in null cells, which is essential for PDGF proliferative and migratory action. We observed no significant differences in the rates of apoptosis in these cells. TSP1Ϫ/Ϫ PCs were also less adherent, expressed increased levels of TSP2 and fibronectin, and had decreased amounts of N-cadherin and ␣ v␤3-integrin on their surface. Thus, TSP1 plays a significant role in retinal PC proliferation and migration impacting retinal vascular development and homeostasis. retinal vasculature; platelet-derived growth factor; platelet-derived growth factor receptor-␤; mesenchymal stem cells; perivascular cells; cell adhesion ANGIOGENESIS, the formation of new blood vessels from preexisting capillaries, is a complex and multistep process. Pathological growth of new blood vessels contributes to a large number of eye diseases, including retinopathy of prematurity, proliferative diabetic retinopathy, and age-related macular degeneration (4, 6, 13). However, the molecular and cellular events that contribute to the initiation of angiogenic events require further delineation. Specific alterations in vascular cells, including endothelial cells (ECs) and perivascular support cells [vascular smooth muscle cells (VSMCs) and pericytes (PCs)], may play an important role in these processes.The mouse retinal vasculature develops postnatally, providing a unique opportunity to study all aspects of ...

Polarized expression of integrin β1 in diencephalic roof plate during chick development, a possible receptor for SCO‐spondin

“…In this context, CCN1, a protein associated with the extracellular matrix that regulates migration, adhesion, and differentiation, contains one TSR domain that binds by an autocrine/paracrine mechanism to several members of the integrin family present in the same cell or in the cells of the vicinity (Chen and Du, 2007). In the same way, thrombospondin 1, a matricellular protein, binds integrins by an autocrine mechanism, regulating cell proliferation and migration (Forslöw et al, 2007;Scheef et al, 2009).…”

Pharmacological Inhibition of Mitochondrial Carbonic Anhydrases Protects Mouse Cerebral Pericytes from High Glucose-Induced Oxidative Stress and Apoptosis

“…IPCs were isolated from Immortomice back-crossed to C57BL/6 mice (Scheef et al, 2009) according to the method of Hayashi et al (2004) with modification. Briefly, brains from 5 to 10 mice (both female and male), ubiquitously expressing a thermolabile strain of tsA58 of the SV40 large T antigen (tsA58 Tag), were removed and placed in Dulbecco's modified Eagle's medium (DMEM) (low glucose; Sigma-Aldrich, St. Louis, MO) on ice.…”

“…The purpose of this study was to investigate the mechanism by which high glucose-induced OxSt causes PC death and to determine whether inhibition of mCA protects PCs from OxSt-induced apoptosis. To address these questions, we established conditionally immortalized cerebral pericytes (IPCs) from the Immortomouse (Scheef et al, 2009). The IPCs can be rapidly expanded under permissive conditions [33°C in the presence of interferon-g (IFN-g)] and can be readily passaged, frozen, and thawed.…”

NG2/CSPG4 Proteoglycan as a Novel Prognostic Indicator and Therapeutic Target in Malignant Cancer

“…PDGF as a mitogen is another contributor to the expansion of the cell matrix in cancer progression because of NG2/CSPG4 binding potential of collagen types to PDGF [71,72]. During cancer progression, regulation of NG2/CSPG4-expressing PC' responds to PDGF and the need of NG2/CSPG4-expressing PCs to receive PDGF signal correlates positively to cancer cell proliferation [73]. In other works, the cancer cell-expressing NG2/CSPG4 generates a supportive "niche" by producing matrix-modulating growth factors.…”