ABSTRACT
Osteoporosis is a bone disease characterized by low bone mass and deteriorated bone microstructure, which could be related to the disorders of energy metabolism and bone senescence. Silent mating-type information regulator 2 homolog 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that regulates cell senescence, energy metabolism and bone remodeling. SIRT1 could be activated not only by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), c-Jun N-terminal kinase 1 (JNK1) and casein kinase 2 (CK2), but also by small-molecular drugs such as resveratrol. All these kinases and drugs can affect bone metabolism. Recent findings indicate that SIRT1 signaling pathway plays a direct role in bone metabolism, but the underlying mechanism remains unclear. This paper reviews the structure and function of SIRT1, and the role of SIRT1 in bone metabolism, and discusses the potential of SIRT1 signaling pathway as a new therapeutic target in osteoporosis.
ABSTRACT
Alzheimer ’ s disease ( AD ) is characterized by pro-gressive loss of memory and other cognitive functions .With re-cent discoveries , activation of silent mating-type information reg-ulator 2 homolog 1 ( SIRT1 ) could attenuate the cognitive dys-function of AD via reducing amyloid-βaggregation and tau pro-tein phosphorylation , inhibiting inflammatory reaction , and regu-lating synaptic plasticity .This review aims to highlight the in-volvement of these new discoveries of SIRT 1, and Akt/protein kinase B(PKB) signaling pathways, for their potential therapeu-tic effect against AD .