iloprost and Fibrosis

Raynaud phenomenon (RP) is the hallmark of Systemic Sclerosis (SSc). Visceral RP has also been proposed in SSc patients. Cardiac Raynaud's phenomenon (C-RP) was evaluated in a few clinical studies both as cold-induced transient myocardial ischaemia and as presence of advanced myocardial fibrosis and contraction band necrosis in autopsied patients. Until today numerous techniques, such as scintigraphy and myocardial contrast echocardiography, have been used to evaluate C-RP. In this case report for the first time we have used Cardiac Magnetic Resonance (CMR) after cold test to demonstrate the presence of the C-RP. In addition we have shown that therapy with Iloprost can be used to reduce episodes of C-RP.

Topics: Antibodies, Antinuclear; Female; Fibrosis; Heart; Humans; Iloprost; Ischemic Attack, Transient; Magnetic Resonance Imaging; Middle Aged; Myocardium; Platelet Aggregation Inhibitors; Raynaud Disease; Recovery of Function; Scleroderma, Systemic

The therapy of systemic sclerosis (SSc) remains a challenge for dermatology, rheumatology, internal medicine, and other disciplines. Organ involvement, above all kidney and lungs, is a key therapeutic issue. The current developments in organ-specific therapy are the main topic of the article. Finally, possibilities of disease-modifying drugs and value of HSCT are discussed.

Topics: Angiotensin-Converting Enzyme Inhibitors; Cardiovascular Diseases; Fibrosis; Fingers; Gastrointestinal Agents; Hematopoietic Stem Cell Transplantation; Humans; Hypertension, Pulmonary; Iloprost; Kidney Transplantation; Piperazines; Purines; PUVA Therapy; Raynaud Disease; Recurrence; Scleroderma, Systemic; Sildenafil Citrate; Skin Ulcer; Sulfones; Ultraviolet Therapy; Vasodilator Agents

Prostacyclin and its analogues improve cardiac output and functional capacity in patients with pulmonary arterial hypertension (PAH); however, the underlying mechanism is not fully understood. We hypothesised that prostanoids have load-independent beneficial effects on the right ventricle (RV). Angio-obliterative PAH and RV failure were induced in rats with a single injection of SU5416 followed by 4 weeks of exposure to hypoxia. Upon confirmation of RV dysfunction and PAH, rats were randomised to 0.1 μg·kg(-1) nebulised iloprost or drug-free vehicle, three times daily for 2 weeks. RV function and treadmill running time were evaluated pre- and post-iloprost/vehicle treatment. Pulmonary artery banded rats were treated 8 weeks after surgery to allow for significant RV hypertrophy. Inhaled iloprost significantly improved tricuspid annulus plane systolic excursion and increased exercise capacity, while mean pulmonary artery pressure and the percentage of occluded pulmonary vessels remained unchanged. Rats treated with iloprost had a striking reduction in RV collagen deposition, procollagen mRNA levels and connective tissue growth factor expression in both SU5416/hypoxia and pulmonary artery banded rats. In vitro, cardiac fibroblasts treated with iloprost showed a reduction in transforming growth factor (TGF)-β1-induced connective tissue growth factor expression, in a protein kinase A-dependent manner. Iloprost decreased TGF-β1-induced procollagen mRNA expression as well as cardiac fibroblast activation and migration. Iloprost significantly induced metalloproteinase-9 gene expression and activity and increased the expression of autophagy genes associated with collagen degradation. Inhaled iloprost improves RV function and reverses established RV fibrosis partially by preventing collagen synthesis and by increasing collagen turnover.

Topics: Animals; Collagen; Cyclic AMP-Dependent Protein Kinases; Echocardiography; Fibroblasts; Fibrosis; Heart Ventricles; Hemodynamics; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Hypoxia; Iloprost; Indoles; Male; Matrix Metalloproteinase 9; Microscopy, Phase-Contrast; Physical Conditioning, Animal; Procollagen; Pyrroles; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta1; Vasodilator Agents; Ventricular Function, Right

Enteroviruses, such as coxsackieviruses of group B (CVB), are able to induce a chronic inflammation of the myocardium, which may finally lead to the loss of functional tissue, remodeling processes and the development of fibrosis, thus affecting the proper contractile function of the heart. In other fibrotic diseases like scleroderma, the prostacyclin agonist iloprost was found to inhibit the extracellular signal-regulated kinase (ERK, p44/42 MAPK), a mitogen-activated protein kinase, and consecutively, the expression of the profibrotic cytokine connective tissue growth factor (CTGF), thereby preventing the development of fibrosis. As CTGF was found to mediate fibrosis in chronic CVB3 myocarditis as well, we evaluated whether the in vivo application of iloprost is capable to reduce the development of ERK/CTGF-mediated fibrosis in enteroviral myocarditis. Unexpectedly, the application of iloprost resulted in a prolonged myocardial inflammation and an aggravated fibrosis and failed to reduce activation of ERK and expression of CTGF at later stages of the disease. In addition, viral replication was found to be increased in iloprost-treated mice. Notably, the expression of cardiac inducible nitric oxide synthase (iNOS), which is known to aggravate myocardial damage in CVB3-infected mice, was strongly enhanced by iloprost. Using cultivated bone marrow macrophages (BMM), we confirmed these results, proving that iloprost potentiates the expression of iNOS mRNA and protein in CVB3-infected and IFN-gamma stimulated BMM. In conclusion, these results suggest a critical reflection of the clinical use of iloprost, especially in patients possibly suffering from an enteroviral myocarditis.

Topics: Animals; Collagen Type I; Collagen Type I, alpha 1 Chain; Connective Tissue Growth Factor; Enterovirus B, Human; Enterovirus Infections; Extracellular Signal-Regulated MAP Kinases; Fibrosis; Iloprost; MAP Kinase Signaling System; Mice; Myocarditis; Myocardium; Nitric Oxide Synthase Type II; Virus Replication

The SMAD-mediated induction of connective tissue growth factor (CTGF), a fibroproliferative cytokine, by transforming growth factor (TGF)beta is required for the development of sustained fibrosis in humans. Here, we show that in fibroblasts, activation of the Ras/MEK/ERK pathway is required for the SMAD-mediated induction of CTGF by TGFbeta2. We then show that activation of protein kinase A (PKA) in fibroblasts is able to block Ras/MEK/ERK signaling and abolish the fibrotic response. Previously, we found that prostacyclin agonists were able to prevent the induction of CTGF in fibroblasts, and in patients with the fibrotic disease scleroderma. Here, we confirm the in vitro and in vivo antifibrotic effects of prostacyclin derivatives and show that these effects are due to PKA-dependent inhibition of the Ras/MEK/ERK pathway. Ras/MEK/ERK does not directly affect SMAD signaling. The coordinate and varied biological responses to TGFbeta are in part due to the interactions of signaling pathways within target cells. Specific inhibition of fibroblast Ras/MEK/ERK signaling might prevent fibrosis while leaving other physiological effects of TGFbeta unaltered.

Topics: Animals; Connective Tissue Growth Factor; Cyclic AMP-Dependent Protein Kinases; DNA-Binding Proteins; Fibroblasts; Fibrosis; Iloprost; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Models, Biological; Proto-Oncogene Proteins p21(ras); Rats; RNA, Messenger; Smad Proteins; Trans-Activators; Transforming Growth Factor beta