Contractile phenotype

Shi-Wen X, Chen Y, Denton CP, Eastwood M, Renzoni EA, Bou-Gharios G, Pearson JD, Dashwood M, du Bois RM, Black CM, Leask A, Abraham DJ. 2004. Endothelin-1 promotes myofibroblast induction through the ETA receptor via a rac/phosphoinositide 3-kinase/Akt-dependent pathway and is essential for the enhanced contractile phenotype of fibrotic fibroblasts. Mol Biol Cell 15 2707-2719. 

Smooth muscle is unique among the three muscle types (cardiac, skeletal, and smooth) because it exists in two distinct phenotypes. The contractile phenotype of smooth muscle is responsible for generating tension the secretory or proliferative phenotype of smooth muscle undergoes cellular division and has only a limited capacity to undergo shortening. Proliferative smooth muscle is commonly derived, in vitro, by plac-... 

These two phenotypes of smooth muscle, in addition to having marked differences in contractile activity, express different isoforms of several contractile proteins and certain soluble enzymes. In particular, proliferative smooth muscle contains at least three PDPKs p34 i 2 p42 , and p44 PK the contractile phenotype of smooth muscle, only p42 P and p44 mark have been identified. The precise function and a complete description of the substrates for MAPK in the contractile phenotype of smooth muscle are unknown however, one substrate that has been idenhfied is the actin and myosin binding protein, caldesmon. Because of the phosphorylation of cal-desmon, MAPK may be involved in either smooth muscle contractile regulation or the structural organization of actin filaments within smooth muscle cells. 

IV. EVIDENCE FOR MITOGEN-ACTIVATED PROTEIN KINASE IN THE CONTRACTILE PHENOTYPE OF SMOOTH MUSCLE... 

The apparent homogeneity in the morphology of adult normal SM tissue is not confirmed when the distribution of some differentiation markers, particularly those inherent to contractility, is taken into account. The contractile activity of adult SM tissues is accomplished by means of specific sets of proteins whose qualitative and quantitative availability determines the final outcome of the functional performance. To fulfill the criterion of the integrated action in developing this function, social interactions among SMC, on the one hand, and between SMC and ECM, on the other, must be established [39]. The cell phenotype that confers the contractile activity to SMC is denominated the contractile phenotype ... 

Before discussing this point (see Sections 5 and 6), it is important to identify the basic molecules that are the hallmark of the contractile phenotype in the adult SMC. 

Fig. 13. Changes of some structural and functional characteristics in cultured SMC. Identity between in vivo and in vitro contractile phenotypes is still debated.

SMC are very plastic cells that are able to change their phenotype in vitro and in vivo between two SM-type cellular extremes the synthetic and the contractile phenotypes. In addition, SMC are developmentally... 

Fisher SA, Ikebe M, Brozovich F (1997) Endothelin-1 alters the contractile phenotype of cultured embryonic smooth muscle cells. Circ Res 80 885-893... 

Kolyada, A. Y., Riley, K. N., and Herman, 1. M. (2003). Rho GTPase signaling modulates cell shape and contractile phenotype in an isoactin-specific manner. Am. J. Physiol. Cell Physiol. 285, C1116-C1121. 

The atherosclerotic process changes the cellular responsiveness and function of the vessel as a result of changes in VSMCs (reviewed in ref. 234) This can be understood by knowing the phenotypic make-up of the VSMC. There are two major phenotypes of arterial VSMCs (224,225) (1) the contractile phenotype found in arterial media and made up of myofilaments it is responsible for contraction and relaxation of the vasculature and (2) the synthetic VSMC phenotype, which is found in the intima during the atherosclerotic process following the migration of contractile VSMC from the media. 

Vascular tissue engineering Modulated smooth muscle cells behavior to eiqiress contractile phenotype, attained spindle shape, oriented and directional migration Xuetal.(2004)... 

The patency of the grafts is also dependent on their abilities to withstand the high pulsatile stresses, which range from 80 to i20 mmHg in arteries and result in radial distensions up to 10%. The robust mechanical properties of the graft are imparted primarily by the tunica media and rely on the aUgn-ment of the smooth muscle cells (SMCs) and their maintenance of a contractile phenotype. The spatial... 

---