RATIONALE: Vascular smooth muscle (SM) cell phenotypic modulation plays an important role in arterial stiffening associated with aging. Serum response factor (SRF) is a major transcription factor regulating SM genes involved in maintenance of the contractile state of vascular SM cells. OBJECTIVE: We investigated whether SRF and its target genes regulate intrinsic SM tone and thereby arterial stiffness. METHODS AND RESULTS: The SRF gene was inactivated SM-specific knockout of SRF (SRF(SMKO)) specifically in vascular SM cells by injection of tamoxifen into adult transgenic mice. Fifteen days later, arterial pressure and carotid thickness were lower in SRF(SMKO) than in control mice. The carotid distensibility/pressure and elastic modulus/wall stress curves showed a greater arterial elasticity in SRF(SMKO) without modification in collagen/elastin ratio. In SRF(SMKO), vasodilation was decreased in aorta and carotid arteries, whereas a decrease in contractile response was found in mesenteric arteries. By contrast, in mice with inducible SRF overexpression, the in vitro contractile response was significantly increased in all arteries. Without endothelium, the contraction was reduced in SRF(SMKO) compared with control aortic rings owing to impairment of the NO pathway. Contractile components (SM-actin and myosin light chain), regulators of the contractile response (myosin light chain kinase, myosin phosphatase target subunit 1, and protein kinase C-potentiated myosin phosphatase inhibitor) and integrins were reduced in SRF(SMKO). CONCLUSIONS: SRF controls vasoconstriction in mesenteric arteries via vascular SM cell phenotypic modulation linked to changes in contractile protein gene expression. SRF-related decreases in vasomotor tone and cell-matrix attachment increase arterial elasticity in large arteries.
RATIONALE: Vascular smooth muscle (SM) cell phenotypic modulation plays an important role in arterial stiffening associated with aging. Serum response factor (SRF) is a major transcription factor regulating SM genes involved in maintenance of the contractile state of vascular SM cells. OBJECTIVE: We investigated whether SRF and its target genes regulate intrinsic SM tone and thereby arterial stiffness. METHODS AND RESULTS: The SRF gene was inactivated SM-specific knockout of SRF (SRF(SMKO)) specifically in vascular SM cells by injection of tamoxifen into adult transgenic mice. Fifteen days later, arterial pressure and carotid thickness were lower in SRF(SMKO) than in control mice. The carotid distensibility/pressure and elastic modulus/wall stress curves showed a greater arterial elasticity in SRF(SMKO) without modification in collagen/elastin ratio. In SRF(SMKO), vasodilation was decreased in aorta and carotid arteries, whereas a decrease in contractile response was found in mesenteric arteries. By contrast, in mice with inducible SRF overexpression, the in vitro contractile response was significantly increased in all arteries. Without endothelium, the contraction was reduced in SRF(SMKO) compared with control aortic rings owing to impairment of the NO pathway. Contractile components (SM-actin and myosin light chain), regulators of the contractile response (myosin light chain kinase, myosin phosphatase target subunit 1, and protein kinase C-potentiated myosin phosphatase inhibitor) and integrins were reduced in SRF(SMKO). CONCLUSIONS:SRF controls vasoconstriction in mesenteric arteries via vascular SM cell phenotypic modulation linked to changes in contractile protein gene expression. SRF-related decreases in vasomotor tone and cell-matrix attachment increase arterial elasticity in large arteries.
Authors: Joanna M S Davies; Josiane Cillard; Bertrand Friguet; Enrique Cadenas; Jean Cadet; Rachael Cayce; Andrew Fishmann; David Liao; Anne-Laure Bulteau; Frédéric Derbré; Amélie Rébillard; Steven Burstein; Etienne Hirsch; Robert A Kloner; Michael Jakowec; Giselle Petzinger; Delphine Sauce; Florian Sennlaub; Isabelle Limon; Fulvio Ursini; Matilde Maiorino; Christina Economides; Christian J Pike; Pinchas Cohen; Anne Negre Salvayre; Matthew R Halliday; Adam J Lundquist; Nicolaus A Jakowec; Fatima Mechta-Grigoriou; Mathias Mericskay; Jean Mariani; Zhenlin Li; David Huang; Ellsworth Grant; Henry J Forman; Caleb E Finch; Patrick Y Sun; Laura C D Pomatto; Onnik Agbulut; David Warburton; Christian Neri; Mustapha Rouis; Pierre Cillard; Jacqueline Capeau; Jean Rosenbaum; Kelvin J A Davies Journal: Geroscience Date: 2017-12-21 Impact factor: 7.713
Authors: Tamas Kiss; Ádám Nyúl-Tóth; Rafal Gulej; Stefano Tarantini; Tamas Csipo; Derek M Huffman; Anna Csiszar; Zoltan Ungvari; Peter Mukli; Anna Ungvari; Priya Balasubramanian; Andriy Yabluchanskiy; Zoltan Benyo; Shannon M Conley; Jonathan D Wren; Lori Garman Journal: Geroscience Date: 2022-02-05 Impact factor: 7.581
Authors: Anne Pizard; Alexandre Gueret; Guillaume Galmiche; Soumaya El Moghrabi; Antoine Ouvrard-Pascaud; Stefan Berger; Pascal Challande; Iris Z Jaffe; Carlos Labat; Patrick Lacolley; Frédéric Jaisser Journal: Hypertension Date: 2013-12-02 Impact factor: 10.190