Vascular biomarkers and correlation with peripheral vasculopathy in systemic sclerosis.

Vascular disease is a hallmark of systemic sclerosis (SSc). It is present in every patient, being responsible both for the earliest clinical manifestations and the major life-threatening complications of the disease, and thus determining important morbidity and mortality. In SSc, progressive vascular injury leads to vascular tone dysfunction and reduced capillary blood flow, with consequent tissue ischemia and chronic hypoxia. These phenomena are often accompanied by abnormal levels of vascular factors. Microangiopathy in SSc may be easily assessed by nailfold videocapillaroscopy. The variety of derangements detected in the nailfold capillaries is accompanied by abnormal levels of different vascular mediators and appears to be the best evaluable predictor of the development of peripheral vascular complications, such as digital ulcers. The purpose of this review is to summarize in SSc the most relevant vascular biomarkers and the main associations between vascular biomarkers and capillaroscopic parameters and/or the presence of digital ulcers. Vascular biomarkers could become useful predictive factors of vascular damage in SSc, allowing an earlier management of vascular complications.

Antitumor and angiostatic peptides from frog skin secretions.

The discovery of new molecules with potential antitumor activity continues to be of great importance in cancer research. In this respect, natural antimicrobial peptides isolated from various animal species including humans and amphibians have been found to be of particular interest. Here, we report the presence of two anti-proliferative peptides active against cancer cells in the skin secretions of the South American tree frog, Phyllomedusa bicolor. The crude skin exudate was fractioned by size exclusion gel followed by reverse-phase HPLC chromatography. After these two purification steps, we identified two fractions that exhibited anti-proliferative activity. Sequence analysis indicated that this activity was due to two antimicrobial α-helical cationic peptides of the dermaseptin family (dermaseptins B2 and B3). This result was confirmed using synthetic dermaseptins. When tested in vitro, synthetic B2 and B3 dermaseptins inhibited the proliferation of the human prostatic adenocarcinoma PC-3 cell line by more than 90%, with an EC(50) of around 2-3 µM. No effect was observed on the growth of the NIH-3T3 non-tumor mouse cell line with Drs B2, whereas a slight inhibiting effect was observed with Drs B3 at high dose. In addition, the two fractions obtained after size exclusion chromatography also inhibited PC-3 cell colony formation in soft agar. Interestingly, inhibition of the proliferation and differentiation of activated adult bovine aortic endothelial cells was observed in cells treated with these two fractions. Dermaseptins B2 and B3 could, therefore, represent interesting new pharmacological molecules with antitumor and angiostatic properties for the development of a new class of anticancer drugs.

Different angiogenic activity in pulmonary sarcoidosis and idiopathic pulmonary fibrosis.

BACKGROUND: Recent evidence has shown that several chemokines--including those involved in angiogenesis--have been implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and sarcoidosis. We speculated that these differences could be attributed to distinct angiogenic and angiostatic profiles. This hypothesis was investigated by estimating the levels of three angiogenic chemokines (growth-related gene [GRO]-alpha, epithelial neutrophil-activating protein [ENA]-78, and interleukin [IL]-8), and three angiostatic chemokines (monokine induced by interferon (IFN)-gamma [MIG], IFN-gamma-inducible protein [IP]-10, and IFN-gamma-inducible T-cell alpha chemoattractant) in serum and BAL fluid (BALF). METHODS: We studied prospectively 20 patients with sarcoidosis (median age, 46 years; range, 25 to 65 years), 20 patients with IPF (median age, 68 years; range, 40 to 75 years), and 10 normal subjects (median age, 39 years; range, 26 to 60 years). RESULTS: The GRO-a serum and BALF levels of IPF patients were found significantly increased in comparison with healthy subjects (799 pg/mL vs 294 pg/mL [p = 0.022] and 1,827 pg/mL vs 94 pg/mL [p < 0.001], respectively) and sarcoidosis patients (799 pg/mL vs 44 pg/mL [p < 0.001] and 1,827 pg/mL vs 214 pg/mL [p < 0.001], respectively). Moreover, ENA-78 and IL-8 BALF levels in IPF patients were significantly higher compared with sarcoidosis patients (191 pg/mL vs 30 pg/mL [p < 0.001] and 640 pg/mL vs 94 pg/mL [p = 0.03], respectively). MIG serum levels in IPF patients were found significantly upregulated in comparison with sarcoidosis patients and healthy control subjects. However, MIG and IP-10 BALF levels (1,136 pg/mL vs 66 pg/mL [p < 0.001] and 112 pg/mL vs 56 pg/mL [p = 0.037], respectively) were significantly higher in sarcoidosis patients compared with IPF patients. CONCLUSIONS: Our data suggest distinct angiogenic profiles between IPF and sarcoidosis, indicating a potential different role of CXC chemokines in the local immunologic response in IPF and pulmonary sarcoidosis.