Expression and suppressive effects of interleukin-19 on vascular smooth muscle cell pathophysiology and development of intimal hyperplasia

Study of vascular injuries using endothelial denudation model and the therapeutic application of shock wave: a review

As death toll from cardiovascular diseases has reached historic heights in the developed world, research efforts have been focused on both the understanding of disease progression and also the choice of appropriate treatment strategies. Moreover, to facilitate research, an appropriate animal model is needed to mimic the pathological changes and follow treatment results. This article reviewed the disease mechanisms underlying vascular injuries and also the animal model of endothelial denudation using balloon catheter. On the other hand, the biological effects of shock wave including angiogenesis and the suppression of inflammation were reviewed. Its therapeutic impact on the cardiovascular system and its potential clinical application as well as limitations were also discussed.

Interleukin-19: multiple roles in immune regulation and disease

First reported in 1999, IL-19 remains a mystery in many ways. Despite appearing in many genome scans and candidate gene studies, and having been searched for specifically as part of the IL-10 family, its function is still to be defined. Nonetheless, a pattern of Th2 promotion is coalescing from this nebulous body of work, supported by increasing evidence for a role in asthma. Similarly, a clear but less intuitive role as a subtle immunomodulator is emerging in psoriasis and chronic inflammatory disorders in general. Indeed, several human diseases and their animal models have highlighted a role for IL-19. Key questions remain, relating to the nature of its receptor, its function (if any) on leukocytes and how its effects are distinguished by the cell from those of IL-20 and IL-24. In this review, I shall attempt to bring together a summary of the known work - disparate as it may be - as well as presenting a picture of these two important clinical disorders and the potential involvement of this somewhat enigmatic cytokine.

Anti-inflammatory cytokine interleukin-19 inhibits smooth muscle cell migration and activation of cytoskeletal regulators of VSMC motility

Vascular smooth muscle cell (VSMC) migration is an important cellular event in multiple vascular diseases, including atherosclerosis, restenosis, and transplant vasculopathy. Little is known regarding the effects of anti-inflammatory interleukins on VSMC migration. This study tested the hypothesis that an anti-inflammatory Th2 interleukin, interleukin-19 (IL-19), could decrease VSMC motility. IL-19 significantly decreased platelet-derived growth factor (PDGF)-stimulated VSMC chemotaxis in Boyden chambers and migration in scratch wound assays. IL-19 significantly decreased VSMC spreading in response to PDGF. To determine the molecular mechanism(s) for these cellular effects, we examined the effect of IL-19 on activation of proteins that regulate VSMC cytoskeletal dynamics and locomotion. IL-19 decreased PDGF-driven activation of several cytoskeletal regulatory proteins that play an important role in smooth muscle cell motility, including heat shock protein-27 (HSP27), myosin light chain (MLC), and cofilin. IL-19 decreased PDGF activation of the Rac1 and RhoA GTPases, important integrators of migratory signals. IL-19 was unable to inhibit VSMC migration nor was able to inhibit activation of cytoskeletal regulatory proteins in VSMC transduced with a constitutively active Rac1 mutant (RacV14), suggesting that IL-19 inhibits events proximal to Rac1 activation. Together, these data are the first to indicate that IL-19 can have important inhibitory effects on VSMC motility and activation of cytoskeletal regulatory proteins. This has important implications for the use of anti-inflammatory cytokines in the treatment of vascular occlusive disease.

Vascular smooth-muscle-cell activation: proteomics point of view

Vascular smooth-muscle cells (VSMCs) are the main component of the artery medial layer. Thanks to their great plasticity, when stimulated by external inputs, VSMCs react by changing morphology and functions and activating new signaling pathways while switching others off. In this way, they are able to increase the cell proliferation, migration, and synthetic capacity significantly in response to vascular injury assuming a more dedifferentiated state. In different states of differentiation, VSMCs are characterized by various repertories of activated pathways and differentially expressed proteins. In this context, great interest is addressed to proteomics technology, in particular to differential proteomics. In recent years, many authors have investigated proteomics in order to identify the molecular factors putatively involved in VSMC phenotypic modulation, focusing on metabolic networks linking the differentially expressed proteins. Some of the identified proteins may be markers of pathology and become useful tools of diagnosis. These proteins could also represent appropriately validated targets and be useful either for prevention, if related to early events of atherosclerosis, or for treatment, if specific of the acute, mid, and late phases of the pathology. RNA-dependent gene silencing, obtained against the putative targets with high selective and specific molecular tools, might be able to reverse a pathological drift and be suitable candidates for innovative therapeutic approaches.

The anti-inflammatory cytokine interleukin 19 is expressed by and angiogenic for human endothelial cells

OBJECTIVE

To characterize the expression and function of interleukin (IL) 19, a recently described T-helper 2 anti-inflammatory IL, on endothelial cell (EC) pathophysiological features.

METHODS AND RESULTS

The expression and effects of anti-inflammatory ILs on EC activation and development of angiogenesis are uncharacterized. We demonstrate by immunohistochemistry and immunoblot that IL-19 is expressed in inflamed, but not normal, human coronary endothelium and can be induced in cultured human ECs by serum and basic fibroblast growth factor. IL-19 is mitogenic and chemotactic, and it promotes EC spreading. IL-19 activates the signaling proteins STAT3, p44/42, and Rac1. In functional ex vivo studies, IL-19 promotes cordlike structure formation of cultured ECs and enhances microvessel sprouting in the mouse aortic ring assay. IL-19 induces tube formation in gelatinous protein (Matrigel) plugs in vivo.

CONCLUSIONS

To our knowledge, these data are the first to report expression of the anti-inflammatory agent, IL-19, in ECs; and the first to indicate that IL-19 is mitogenic and chemotactic for ECs and can induce the angiogenic potential of ECs.

IL-10 family of cytokines

In 2001, six immune mediators (IL-10, IL-19, IL-20, IL-22, IL-24, and IL-26) were grouped into the so-called IL-10 family of cytokines based on their similarities with respect to the structure and location of their encoding genes, their primary and secondary protein structures, and the receptor complexes used. Surprisingly, despite all these similarities, IL-10 family members possess different biological functions. The currently known facts regarding the biological effects of these six immune mediators give the impression that at least IL-10, IL-20, and IL-22 play an important role in the pathogenesis of some chronic inflammatory diseases. This review provides an overview of the most important and common aspects of the IL-10 family members.

Structure and function of interleukin-22 and other members of the interleukin-10 family

The IL-10 family of cytokines is comprised of IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and IFN-lambdas (IL-28A, IL-28B, and IL-29). The IL-10 family members bind to shared class II cytokine receptor chains that associate in various combinations in heterodimeric complexes. Upon interleukin/receptor complex formation, these proteins switch on the Jak/STAT pathway and elicit pleiotropic biological responses whose variety sharply contrasts with their structural similarities. IL-10 family members are involved in several human diseases and health conditions and hence their structural analyses may provide valuable information to design specific therapeutic strategies. In this review, we describe the human interleukin-10 family of cytokines, focusing on their structures and functions, with particular attention given to IL-22 and IL-10. We report on the recently published structures of IL-10 cytokine family members and their complexes with cognate transmembrane and soluble receptors as well as on interleukin physiology and physiopathology.

Il-19 reduces VSMC activation by regulation of mRNA regulatory factor HuR and reduction of mRNA stability

While much is known about the deleterious effects of pro-inflammatory cytokines on development of vascular disease, little is reported on the direct effects of anti-inflammatory cytokines on the vascular smooth muscle cell (VSMC) response to injury. Interleukin-19 (IL-19) is a recently described Th2, anti-inflammatory interleukin. We have previously reported that IL-19 is absent in normal VSMC, but induced in VSMC by inflammatory cytokines and in arteries by injury. IL-19 is anti-proliferative for VSMC. The purpose of this study is to determine the molecular mechanism of these effects. In cultured, primary human VSMC, IL-19 reduces abundance of proliferative and inflammatory gene proteins and mRNA, including Cyclin D1, IL-1beta, IL-8, and COX2. IL-19 does not inhibit NF-kappaB, but does transiently reduce cytoplasmic abundance of the mRNA stability factor HuR. The mRNA stabilizing function of HuR is linked to its phosphorylation and cytoplasmic translocation. IL-19 reduces serine phosphorylation of HuR, and activation of PKCalpha, a known regulator of HuR translocation. Actinomycin D transcription blockade demonstrates that IL-19 treatment significantly reduces stability of proliferative and inflammatory mRNAs. Knock down of HuR with siRNA also reduces stability of these inflammatory mRNA transcripts. These data indicate that IL-19 has direct effects on VSMC mRNA stability. One potential mechanism whereby IL-19 reduces the VSMC response to injury is by regulation of HuR abundance and cytoplasmic translocation, with a subsequent decrease in mRNA half-life of proliferative and inflammatory mRNA transcripts.