The Pivotal Role of Airway Smooth Muscle in Asthma Pathophysiology

Table 3

Excitation/contraction coupling in ASM cells.

MLCK/MLCP balance	Extracellular factors	Intracellular factors	Actions	Consequences	References
Dependent		CaMKII	I: MLCK	R	[84]
	β-adrenergic agonist	PKA	I: MLCK	R	[85]
	β-adrenergic agonist	PDE4D increase	I: PKA	C	[86]
		PKG	A: MLCP	R	[87]
	TNF-α (TNFSF2), IL-13	Rho-kinase	I: MLCP	C	[87]
	TNF-α (TNFSF2)	Arachidonic acid	A: Rho kinase	C	[88, 89]
	TNF-α (TNFSF2)	Arachidonic acid	I: MLCP	C	[88, 90]
		CPI-17	I: MLCP	C	[87]
		C/EBP-α decrease	I: MLCK	C	[72]
Independent		Caldesmon	I: Myosin ATPase activity	R	[91]
		Calponin	I: Myosin ATPase activity	R	[92]
		PKCε	I: Caldesmon	C	[75]
		PKCε	I: Calponin	C	[75]
	Derp1, LPS	MAPK	I: Caldesmon	C	[75, 93, 94]
	TNF-α (TNFSF2), IL-13	Rho-kinase	I: Calponin	C	[95]
		CaMKII	I: Calponin	C	[95]
		HSP phosphorylated	I: Contraction	R	[96, 97]

A: active; C: contracting; CaMKII: calcium/calmodulin-dependent protein kinase; CPI-17: 17-kDa PKC-potentiated inhibitory protein of PP1; C/EBPα: CCAAT/enhancer binding protein α; Derp1: house dust mite allergen; HSP: heat shock protein; I: inhibit; IL-13: interleukin-13; LPS: lipopolysaccharide; MAPK: mitogen-activated protein kinase; MLCK: myosin light chain kinase; MLCP: myosin light chain phosphatase; PDE4D: phosphodiesterase 4D, cAMP-specific; PKA: cAMP-dependent protein kinase A; PKCε: protein kinase C ε; PKG: cGMP-dependent protein kinase G; R: relaxing; PP1: protein phosphatase 1; TNF-α: tumor necrosis factor α.