The prostacyclin receptor induces human vascular smooth muscle cell differentiation via the protein kinase A pathway

Fetalvero, Kristina M.; Shyu, Maureen; Nomikos, Athena P.; Chiu, Yuh-Fang; Wagner, Robert J.; Powell, Richard J.; Hwa, John; Martin, Kathleen A.

doi:10.1152/ajpheart.00936.2005

Cited by 68 publications

(75 citation statements)

References 38 publications

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“…Human VSMCs were cultured in M199 medium with 10% FBS, and supplements as described previously (22). Bovine or rat aortic SMCs were isolated and cultured as described before (7).…”

Section: Methodsmentioning

confidence: 99%

“…Twenty-four hours prior to drug treatment, cells were transferred to media containing 0% or 2.5% FBS for the duration of the experiment as indicated in the figure legends. VSMCs cultured in 2.5% FBS proliferate slowly and do not spontaneously differentiate (7,16,22). VSMCs were treated with vehicle (ethanol for rapamycin) or drug (rapamycin (Calbiochem) or IGF-I (Upstate, Charlottesville, VA)) as indicated in the figure legends.…”

Section: Methodsmentioning

confidence: 99%

“…Western Blotting-Whole cell lysates were prepared and quantitated by Bradford assay as previously described (7,16,22). Equal amounts of protein per lane were subjected to SDS-PAGE, transferred to a membrane, and immunoblotted using antibodies against SM2-MHC (Seikagaku America, Cape Cod, MA), h-caldesmon, SM␣-actin, calponin 1 (Sigma), GAPDH, anti-phosphotyrosine (PY20), ␤-tubulin (Santa Cruz Biotechnology, Santa Cruz, CA), Akt1, Akt2, total Akt, phospho-Ser-473 Akt, phospho-Ser-9 GSK-3␤, total GSK3-␤, S6K1, total S6, phospho-S6 (Ser-235/236), IRS-1 phospho-Ser-636, or phospho-Ser302 (Cell Signaling, Boston, MA), or total IRS-1 (Upstate), horseradish peroxidase-conjugated secondary antibodies, and chemiluminescent detection and autoradiography as described (7,16,22).…”

Section: Methodsmentioning

confidence: 99%

“…Semi-quantitative Reverse Transcription-PCR-Total RNA was isolated as described before (7,22), and 500 ng was reverse transcribed using an iScript cDNA synthesis kit (Bio-Rad). Titrations of the reverse-transcribed cDNA were performed to determine the linear range of the PCR for all primer sets.…”

Section: Methodsmentioning

confidence: 99%

“…Titrations of the reverse-transcribed cDNA were performed to determine the linear range of the PCR for all primer sets. PCR was performed using primers for SM-MHC, and pyruvate dehydrogenase, and products analyzed by agarose gel electrophoresis as described (22). Primers for Akt2 were 5Ј-ATGAAT-GAGGTGTCTGTCATCAAAGAAGGC and 3Ј-TGCTT-GAGGCTGTTGGCGACC.…”

Section: Methodsmentioning

confidence: 99%

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Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling

Martin

Merenick

Ding

et al. 2007

Journal of Biological Chemistry

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The phenotypic plasticity of mature vascular smooth muscle cells (VSMCs) facilitates angiogenesis and wound healing, but VSCM dedifferentiation also contributes to vascular pathologies such as intimal hyperplasia. Insulin/insulin-like growth factor I (IGF-I) is unique among growth factors in promoting VSMC differentiation via preferential activation of phosphatidylinositol 3-kinase (PI3K) and Akt. We have previously reported that rapamycin promotes VSMC differentiation by inhibiting the mammalian target of rapamycin (mTOR) target S6K1. Here, we show that rapamycin activates Akt and induces contractile protein expression in human VSMC in an insulin-like growth factor I-dependent manner, by relieving S6K1-dependent negative regulation of insulin receptor substrate-1 (IRS-1). In skeletal muscle and adipocytes, rapamycin relieves mTOR/S6K1-dependent inhibitory phosphorylation of IRS-1, thus preventing IRS-1 degradation and enhancing PI3K activation. We report that this mechanism is functional in VSMCs and crucial for rapamycin-induced differentiation. Rapamycin inhibits S6K1-dependent IRS-1 serine phosphorylation, increases IRS-1 protein levels, and promotes association of tyrosine-phosphorylated IRS-1 with PI3K. A rapamycin-resistant S6K1 mutant prevents rapamycin-induced Akt activation and VSMC differentiation. Notably, we find that rapamycin selectively activates only the Akt2 isoform and that Akt2, but not Akt1, is sufficient to induce contractile protein expression. Akt2 is required for rapamycin-induced VSMC differentiation, whereas Akt1 appears to oppose contractile protein expression. The anti-restenotic effect of rapamycin in patients may be attributable to this unique pattern of PI3K effector regulation wherein anti-differentiation signals from S6K1 are inhibited, but pro-differentiation Akt2 activity is promoted through an IRS-1 feedback signaling mechanism. Vascular smooth muscle cells (VSMCs)3 maintain a phenotypic plasticity that is important in physiological processes such as arteriogenesis, and in pathological responses, including atherosclerosis, intimal hyperplasia, and restenosis. Mature VSMCs are quiescent and exhibit a differentiated, contractile phenotype. Differentiation status in vitro can be measured by expression of smooth muscle-specific contractile proteins, including calponin, caldesmon, and smooth muscle myosin heavy chain (SM-MHC) (1). In response to injury, or upon in vitro culture, VSMCs re-enter the cell cycle, proliferate, migrate toward attractants, down-regulate expression of contractile proteins, and up-regulate protein synthesis, particularly of the extracellular matrix. This de-differentiated phenotype is referred to as "synthetic" because of this property (1).VSMC de-differentiation and resultant intimal hyperplasia in response to vessel injury are common problems following vascular interventions such as angioplasty, stent placement, and bypass grafts. Since receiving FDA approval in 2003, the use of the mTOR inhibitor rapamycin on drug-eluting stents has had a profound impac...

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“…Human VSMCs were cultured in M199 medium with 10% FBS, and supplements as described previously (22). Bovine or rat aortic SMCs were isolated and cultured as described before (7).…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling

Martin

Merenick

Ding

et al. 2007

Journal of Biological Chemistry

Self Cite

132

170

View full text Add to dashboard Cite

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Phenotypic switching of vascular smooth muscle cells in atherosclerosis, hypertension, and aortic dissection

Elmarasi,

Elmakaty,

Elsayed

et al. 2024

Journal Cellular Physiology

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Vascular smooth muscle cells (VSMCs) play a critical role in regulating vasotone, and their phenotypic plasticity is a key contributor to the pathogenesis of various vascular diseases. Two main VSMC phenotypes have been well described: contractile and synthetic. Contractile VSMCs are typically found in the tunica media of the vessel wall, and are responsible for regulating vascular tone and diameter. Synthetic VSMCs, on the other hand, are typically found in the tunica intima and adventitia, and are involved in vascular repair and remodeling. Switching between contractile and synthetic phenotypes occurs in response to various insults and stimuli, such as injury or inflammation, and this allows VSMCs to adapt to changing environmental cues and regulate vascular tone, growth, and repair. Furthermore, VSMCs can also switch to osteoblast‐like and chondrocyte‐like cell phenotypes, which may contribute to vascular calcification and other pathological processes like the formation of atherosclerotic plaques. This provides discusses the mechanisms that regulate VSMC phenotypic switching and its role in the development of vascular diseases. A better understanding of these processes is essential for the development of effective diagnostic and therapeutic strategies.

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Frostbite

Nguyen

Chandler

Ratanshi

et al. 2019

Handbook of Burns Volume 1

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The prostacyclin receptor induces human vascular smooth muscle cell differentiation via the protein kinase A pathway

Abstract: . The prostacyclin receptor induces human vascular smooth muscle cell differentiation via the protein kinase A pathway.

Cited by 68 publications

References 38 publications

Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling

Rapamycin Promotes Vascular Smooth Muscle Cell Differentiation through Insulin Receptor Substrate-1/Phosphatidylinositol 3-Kinase/Akt2 Feedback Signaling

Phenotypic switching of vascular smooth muscle cells in atherosclerosis, hypertension, and aortic dissection

Frostbite

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