Serum oxidized low-density lipoprotein is inversely correlated to telomerase activity in peripheral blood mononuclear cells of haemodialysis patients.
BACKGROUND
Telomerase preserves telomeres' function and structure preventing cellular senescence. Its activity is reduced in peripheral blood mononuclear cells (PBMC) of haemodialysis (HD) patients. The purpose of this study is to investigate the potential correlation between increased oxidative stress/inflammation and telomerase activity in PBMC of HD patients.


METHODS
Telomerase activity was measured by PCR-ELISA in PBMC isolated from a group of 42 HD patients and 39 subjects with estimated glomerular filtration rate >or=80 mL/min (control group). Serum oxidized low-density lipoprotein (ox-LDL), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were also measured in both groups by ELISA.


RESULTS
Ox-LDL was negatively correlated to percentage telomerase activity in PBMC (r = -0.506, P = 0.000 in the whole group of 81 HD and normal subjects and r = -0.559, P < 0.001 in HD patients). TNF was also inversely associated with percentage telomerase activity in the whole group studied (r = -0.492, P = 0.000) while IL-10 was not. In stepwise multiple linear regression, taking into consideration the most important characteristics of the HD patients and control group, the only significant predictors for percentage telomerase activity in PBMC were ox-LDL and TNF (beta = -0.421, t = -4.083, P = 0.000 and beta = -0.381, t = -3.691, P = 0.000, respectively) while examining separately HD patients, the predictors for the same parameter were ox-LDL and HD duration (beta = -0.671, t = -4.709, P = 0.000 and beta = -0.349, t = -2.447, P = 0.023, respectively).


CONCLUSIONS
Ox-LDL serum level is inversely correlated to telomerase activity in PBMC of HD patients. Our study proposes a new consequence of increased oxidative stress in HD patients: the premature cellular senescence potentially related to atherosclerosis through LDL oxidation.
Tsirpanlis
George
G
Department of Nephrology, General Hospital of Athens, Greece. tsipg@ath.forthnet.gr
Chatzipanagiotou
Stylianos
S
Boufidou
Fotini
F
Kordinas
Vasileios
V
Zoga
Margarita
M
Alevyzaki
Fotini
F
Stamatelou
Kyriaki
K
Frangou
Eleni
E
Savva
Lefkothea
L
Nicolaou
Chrysoula
C
D000328:Adult; D050197:Atherosclerosis / Q000276:immunology / Q000378:metabolism; D016922:Cellular Senescence; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D016753:Interleukin-10 / Q000097:blood; D007676:Kidney Failure, Chronic / Q000276:immunology* / Q000378:metabolism* / Q000628:therapy; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D006435:Renal Dialysis; D019098:Telomerase / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D008077:Lipoproteins, LDL; D014409:Tumor Necrosis Factor-alpha; C099252:oxidized low density lipoprotein; D016753:Interleukin-10; D019098:Telomerase