Experimental gerontology
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Experimental gerontology · Jan 2015
Plasminogen activator inhibitor 1, fibroblast apoptosis resistance, and aging-related susceptibility to lung fibrosis.
Idiopathic pulmonary fibrosis (IPF) is a fatal lung disorder with unknown cause and no effective treatment. The incidence of and mortality from IPF increase with age, suggesting that advanced age is a major risk factor for IPF. The mechanism underlying the increased susceptibility of the elderly to IPF, however, is unknown. ⋯ Inhibition of PAI-1 activity with a PAI-1 inhibitor, on the other hand, eliminated the aging-related apoptosis resistance and TGF-β1 sensitivity in isolated fibroblasts. Moreover, we show that knocking down PAI-1 in human lung fibroblasts with PAI-1 siRNA significantly increased their sensitivity to apoptosis and inhibited their responses to TGF-β1. Together, the results suggest that increased PAI-1 expression may underlie the aging-related sensitivity to lung fibrosis in part by protecting fibroblasts from apoptosis.
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Experimental gerontology · Jan 2015
Effects of short-term training combining strength and balance exercises on maximal strength and upright standing steadiness in elderly adults.
This study investigated the effects of two training programmes of 6 weeks combining strength and balance exercises in different proportions. One training programme [n=10; 71.4 (6.3) years] consisted mainly of strength exercises (ST) and the other programme [n=8; 71.4 (6.4) years] included a majority of balance exercises (BT). Maximal strength of lower leg muscles and centre of pressure (CoP) steadiness during upright stance in various sensory conditions were measured before and after training. ⋯ The electromyographic activity of the ankle plantar flexor muscles during upright standing decreased (p<0.05) after training but not for the tibialis anterior. Results obtained for H reflex and MEP input-output relations suggest an increased efficacy of Ia afferents to activate low-threshold motor neurones and a decrease in corticospinal excitability after training. This study indicates that short-term training combining strength and balance exercises increases maximal strength and induces change in the neural control of lower leg muscles during upright standing.