The interaction of endothelin-1 and TGF-ß1 mediates vascular cell remodeling.

BACKGROUND: Pulmonary arterial hypertension is characterized by increased thickness of pulmonary vessel walls due to both increased proliferation of pulmonary arterial smooth muscle cell (PASMC) and deposition of extracellular matrix. In patients suffering from pulmonary arterial hypertension, endothelin-1 (ET-1) synthesis is up-regulated and may increase PASMC activity and vessel wall remodeling through transforming growth factor beta-1 (TGF-ß1) and connective tissue growth factor. OBJECTIVE: To assess the signaling pathway leading to ET-1 induced proliferation and extracellular matrix deposition by human PASMC. METHODS: PASMC were serum starved for 24 hours before stimulation with either ET-1 and/or TGF-ß1. ET-1 was inhibited by Bosentan, ERK1/2 mitogen activated protein kinase (MAPK) was inhibited by U0126 and p38 MAPK was inhibited by SB203580. RESULTS: ET-1 increased PASMC proliferation when combined with serum. This effect involved the mitogen activated protein kinases (MAPK) ERK1/2 MAPK and was abrogated by Bosentan which caused a G1- arrest through activation of p27((Kip)). Regarding the contribution of extracellular matrix deposition in vessel wall remodeling, TGF-ß1 increased the deposition of collagen type-I and fibronectin, which was further increased when ET-1 was added mainly through ERK1/2 MAPK. In contrast, collagen type-IV was not affected by ET-1. Bosentan dose-dependently reduced the stimulatory effect of ET-1 on collagen type-I and fibronectin, but had no effect on TGF-ß1. CONCLUSION AND CLINICAL RELEVANCE: ET-1 alone does not induce PASMC proliferation and extracellular matrix deposition. However, ET-1 significantly up-regulates serum induced proliferation and TGF-ß1 induced extracellular matrix deposition, specifically of collagen type-I and fibronectin. The synergistic effects of ET-1 on serum and TGF-ß1 involve ERK1/2 MAPK and may thus present a novel mode of action in the pathogenesis of pulmonary arterial hypertension.

Neurocognitive training in patients with high-grade glioma: a pilot study.

Although their neurocognitive performance is one of the major concerns of patients with high-grade gliomas (HGG) and although neurocognitive deficits have been described to be associated with negative outcome, neurocognitive rehabilitation is usually not integrated into the routine care of patients with malignant gliomas. In this pilot trial, a weekly group training session for attention, verbal, and memory skills was offered to patients with HGG with pre and post-training evaluation. Eleven patients, six with glioblastoma multiforme and five with WHO grade III gliomas, median age 50 years, with a Karnofsky performance score of 80-100 participated in ten group training sessions of 90 min. For evaluation at baseline and after the training by a neuropsychologist not involved in care or training of the patients, Trail Making Tests A and B (TMTA and TMTB), Hopkins Verbal Learning Test (HVLT), and the Controlled Oral Word Association Test (COWA) were used. Comparison of mean group differences between baseline and at post-training evaluation after 12 weeks revealed improvement across all neurocognitive variables. The patients showed a great diversity in their performances, with worsening, improvement, and stabilization. However, a significant group difference was detected only for the HVLT (score 19.6 +/- 8.9 at baseline, 23.6 +/- 8.8 after 12 weeks, P = 0.04). This pilot study shows that neurocognitive training in patients with HGG is feasible as group training with weekly sessions and might be able to induce improvements in attention and memory skills.