Effects of intra- and extracellular factors on anti-aging klotho gene expression

Abstract

ABSTRACT. Inactivation of the klotho gene in mice causes serious systemic disorders, resembling human aging. However, at the molecular level, its action mechanisms are not well understood. The stimulatory or inhibitory effects of cis-and trans-regulatory factors on the klotho gene expression are also still unclear. We studied the effects of intra-and extracellular factors on human klotho gene expression. For this purpose, pHKP-Luc and pHKP-GFP reporter vectors were constructed with the 2.1-kbp upstream region of human klotho, covering its promoter region, using luciferase and GFP genes as the reporter. A series of vectors that have deletions in the upstream region of the klotho gene were constructed to assay cisacting factors. Deletion of some parts of the klotho gene upstream region significantly affected reporter gene expression in HEK293 cells. p16 and p53 proteins inhibited reporter luciferase expression under the control of human klotho promoter in a dose-dependent manner. Calcium and phosphate ions stimulated klotho expression. K. Turan and P. Ata p21, PTH, IGF-1, and angiotensin-II had no significant effect on klotho expression in HEK293 cells.

Complement Modulation of Anti-Aging Factor Klotho in Ischemia/Reperfusion Injury and Delayed Graft Function

“…Interestingly, NF-kB inhibition abrogated C5a-induced Klotho reduction in TEC as indicated by cytofluorimetric analysis ( Figure 3J). The observed bimodal expression of Klotho was related to apoptotic rates occurring in the different experimental conditions (Figure S2), since apoptosis inhibits Klotho expression (19).…”

The effects of DNA methyl transferases on antiaging klotho gene expression

“…The nucleotide sequence of each plasmid was confirmed by DNA sequencing. Reporter plasmid vectors pHKP-Luc, pHKPDII-Luc, and pHKPDVII-Luc, encoding luciferase under the control of human klotho promoters, were generated as previously reported (Turan and Ata, 2011).…”

“…The effects of overexpression of DNMT enzymes were analyzed by quantitation of luciferase expression from a reporter plasmid carrying the luciferase gene under the control of human klotho gene promoter. In the experiments, three different reporter vectors (pHK-luc, pHKPDVII-luc, and pHKPDVIII-luc) with different sized upstream regions of human klotho gene promoter (Turan and Ata, 2011) were used. The relative luciferase activities, as a ratio of Firefly luciferase to Renilla luciferase in lysates prepared from cells co-transfected with DNMT expression vectors and reporter vectors, are given in Figure 3.…”

Infection and smoking are associated with decreased plasma concentration of the anti-aging protein, α-klothoa

“…The extracellular domain of the klotho protein is cleaved on the surface by membrane-anchored protease, such as A Disintegrin and Metalloproteinase Domain-containing protein 10 (ADAM10), ADAM17, and Beta-secretase 1(BACE1). This leads to the release of the secreted form of klotho (soluble α-klotho) into blood, urine, and cerebrospinal fluid[18, 32, 83, 191]. Soluble α-klotho is thought to play an important role in protecting cells and tissues from oxidative stress[51, 196, 201, 214].…”

“…Prior studies have focused on the roles of Klotho in chronic renal disorders[37, 74-76, 142, 178, 184, 214], disorders of calcium metabolism[2, 5, 8, 73, 82, 84, 190], hypertension,[33, 123, 132, 175, 197] and aging[49, 93, 96, 109, 187, 191]. Kuro-o et al demonstrated that klotho is also expressed in the placenta; however, of pregnancy complications has not been investigated [96].…”