Table 1.

Comparison of phenotypes between klotho deficient and klotho overexpression mice

Parameters	Klotho deficient mice	Klotho overexpression mice
Body weight	Showing growth retardation and becoming inactive and marantic at 3 to 4 weeks of age (Kuro-o et al., 1997).	Normal (Kurosu et al., 2005)
Average lifespan	About 2 months (vs 2.5 to 3 years for wild-type mice) (Kuro-o et al., 1997).	About 20–30% longer than wild-type mice (Kurosu et al., 2005).
Maximal lifespan	Less than 100 days (Kuro-o et al., 1997).	More than 936 days (Kurosu et al., 2005).
Insulin	Decreased insulin secretion and enhanced insulin sensitivity (Kuro-o et al., 1997).	Increased resistance to insulin and IGF-1 signaling (Kurosu et al., 2005).
Phosphorus homeostasis	Hyperphosphatemia (Kuro-o et al., 1997).	Normal (Kurosu et al., 2005).
Calcium homeostasis	Ectopic calcification in various organs (Kuro-o et al., 1997).	Normal (Kurosu et al., 2005).
Diseases	Hypogonadism, infertility, premature thymic involution, ectopic calcification, decreased bone mineral density, skin and muscle atrophy, ataxia, emphysema, cognitive impairment, hearing loss, vascular calcification (Kuro-o et al., 1997). Reduction of NO synthesis in vascular endothelial cells (Saito et al., 1998).	Protection of the angiotensin II-induced renal damage (Mitani et al., 2002). Suppression of H2O2-induced apoptosis and cellular senescence in vascular cells (Ikushima et al., and 2006). Reduction of risk factors for atherosclerosis. Enhanced hearing ability (Bektas et al., 2004)