Translational research : the journal of laboratory and clinical medicine
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MicroRNAs (miRNAs) are a family of small RNAs that are ∼20 nucleotides in length and are nontranslated. To date, more than 700 miRNAs have been identified, and their involvement in many essential cellular processes is now apparent. By binding with target messenger RNAs (mRNA), miRNAs are able to regulate both mRNA stability and mRNA translational efficiency. ⋯ As for the integrin β subunits, regulation by miRNAs has been reported for all but β5 and β6 to date. However, computational predictions suggest that numerous miRNAs potentially regulate a variety of target integrins. These predictions will undoubtedly guide future investigations of mechanisms underlying integrin expression mechanism and may ultimately yield new therapeutic tools.
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Different anatomic and physiological changes occur in the lung of aging people that can affect pulmonary functions, and different pulmonary diseases, including deadly diseases such as chronic obstructive pulmonary disease (COPD)/emphysema and idiopathic pulmonary fibrosis (IPF), can be related to an acceleration of the aging process. The individual genetic background, as well as exposure to a variety of toxic substances (cigarette smoke in primis) can contribute significantly to accelerating pulmonary senescence. ⋯ According to recently proposed pathogenic models in COPD and IPF, premature cellular senescence likely affects distinct progenitors cells (mesenchymal stem cells in COPD, alveolar epithelial precursors in IPF), leading to stem cell exhaustion. In this review, the large amount of data supporting this pathogenic view are discussed, with emphasis on the possible molecular and cellular mechanisms leading to the severe parenchymal remodeling that characterizes, in different ways, these deadly diseases.