ICOS-Ligand Triggering Impairs Osteoclast Differentiation and Function In Vitro and In Vivo.

Osteoblasts, osteocytes, and osteoclasts (OCs) are involved in the bone production and resorption, which are crucial in bone homeostasis. OC hyperactivation plays a role in the exaggerated bone resorption of diseases such as osteoporosis, rheumatoid arthritis, and osteolytic tumor metastases. This work stems from the finding that OCs can express B7h (ICOS-Ligand), which is the ligand of the ICOS T cell costimulatory molecule. Because recent reports have shown that, in endothelial, dendritic, and tumor cells, B7h triggering modulates several activities of these cells, we analyzed the effect of B7h triggering by recombinant ICOS-Fc on OC differentiation and function. The results showed that ICOS-Fc inhibits RANKL-mediated differentiation of human monocyte-derived OC-like cells (MDOCs) by inhibiting the acquirement of the OC morphology, the CD14- cathepsin K+ phenotype, and the expression of tartrate-resistant acid phosphatase, OSCAR, NFATc1, and DC-STAMP. Moreover, ICOS-Fc induces a reversible decrease in the sizes of cells and nuclei and cathepsin K expression in mature MDOCs. Finally, ICOS-Fc inhibits the osteolytic activities of MDOCs in vitro and the development of bone loss in ovariectomized or soluble RANKL-treated mice. These findings open a novel field in the pharmacological use of agonists and antagonists of the ICOS-B7h system.

Iloprost modulates the immune response in systemic sclerosis.

BACKGROUND: Iloprost has been suggested to possess anti-inflammatory and immunomodulating actions and it is widely use as a vasodilatator in systemic sclerosis (SSc). In this study we evaluate the effect of iloprost on immune response in SSc patients. To this extend we enrolled 15 women affected by SSc and infused iloprost for 5 days. The effect of iloprost on T cells and monocytes was measured by flow cytometry, Real time PCR and measuring cytokines production in vivo and in vitro by ELISA. RESULTS: Our results demonstrate that Iloprost reduces T cell and TNF alpha production both in vivo and in vitro. It reduces T regulatory cells number, but increases their activity after immune stimulation. It increases serum IL-2 and this increase persists 28 days after the last infusion, also RANKL was increased both in vivo and in vitro. We observed no effect on IFN gamma production. CONCLUSIONS: These results suggest that iloprost has anti-inflammatory and immunomodulating effects, reducing TNF alpha production by T cells and the number of T regulatory cells and increasing IL-2 and RANKL.

From mitochondria to healthy aging: The role of branched-chain amino acids treatment: MATeR a randomized study.

RATIONALE: Malnutrition often affects elderly patients and significantly contributes to the reduction in healthy life expectancy, causing high morbidity and mortality. In particular, protein malnutrition is one of the determinants of frailty and sarcopenia in elderly people. METHODS: To investigate the role of amino acid supplementation in senior patients we performed an open-label randomized trial and administered a particular branched-chain amino acid enriched mixture (BCAAem) or provided diet advice in 155 elderly malnourished patients. They were followed for 2 months, assessing cognitive performance by Mini Mental State Examination (MMSE), muscle mass measured by anthropometry, strength measure by hand grip and performance measured by the Timed Up and Go (TUG) test, the 30 s Chair Sit to Stand (30-s CST) test and the 4 m gait speed test. Moreover we measured oxidative stress in plasma and mitochondrial production of ATP and electron flux in peripheral blood mononuclear cells. RESULTS: Both groups improved in nutritional status, general health and muscle mass, strength and performance; treatment with BCAAem supplementation was more effective than simple diet advice in increasing MMSE (1.2 increase versus 0.2, p = 0.0171), ATP production (0.43 increase versus -0.1, p = 0.0001), electron flux (0.50 increase versus 0.01, p < 0.0001) and in maintaining low oxidative stress. The amelioration of clinical parameters as MMSE, balance, four meter walking test were associated to increased mitochondrial function. CONCLUSIONS: Overall, our findings show that sustaining nutritional support might be clinically relevant in increasing physical performance in elderly malnourished patients and that the use of specific BCAAem might ameliorate also cognitive performance thanks to an amelioration of mitochondria bioenergetics.