A rise in NAD precursor nicotinamide mononucleotide (NMN) after injury promotes axon degeneration.

NAD metabolism regulates diverse biological processes, including ageing, circadian rhythm and axon survival. Axons depend on the activity of the central enzyme in NAD biosynthesis, nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2), for their maintenance and degenerate rapidly when this activity is lost. However, whether axon survival is regulated by the supply of NAD or by another action of this enzyme remains unclear. Here we show that the nucleotide precursor of NAD, nicotinamide mononucleotide (NMN), accumulates after nerve injury and promotes axon degeneration. Inhibitors of NMN-synthesising enzyme NAMPT confer robust morphological and functional protection of injured axons and synapses despite lowering NAD. Exogenous NMN abolishes this protection, suggesting that NMN accumulation within axons after NMNAT2 degradation could promote degeneration. Ectopic expression of NMN deamidase, a bacterial NMN-scavenging enzyme, prolongs survival of injured axons, providing genetic evidence to support such a mechanism. NMN rises prior to degeneration and both the NAMPT inhibitor FK866 and the axon protective protein Wld(S) prevent this rise. These data indicate that the mechanism by which NMNAT and the related Wld(S) protein promote axon survival is by limiting NMN accumulation. They indicate a novel physiological function for NMN in mammals and reveal an unexpected link between new strategies for cancer chemotherapy and the treatment of axonopathies

HRM professionals and their perceptions of HRM and firm performance in the Philippines

This paper reports the findings of a study conducted in the Philippines that examines the extent of adoption of human capital-enhancing human resource (HR) and industrial relations (IR) practices. Differences between locally owned and other organizations in these practices and their relationship to firm performance were also investigated. Questionnaire responses were obtained from managers and union representatives from 128 organizations located in the Philippines. The results indicated that there was, on average, a fairly high level of adoption of practices consistent with a strategic approach to human resource management (HRM), with foreign-owned firms tending to show a slightly higher level of adoption of such practices. A scale representing the adoption of a more conciliatory and union-friendly IR approach was found to be a significant predictor of perceived firm performance. Surprisingly, the level of strategic integration between HRM and business planning and most human capital-enhancing HR practices were not significant predictors of perceived firm performance. Research and practical implications in relation to the role of HRM in enhancing firm performance are discussed