Post-transcriptional regulation of interleukin 1 alphain various strains of young and senescent human umbilical vein endothelialcells.

Abstract

Human umbilical vein endothelial cell (HU-VEC) senescence in vitro is characterized by the loss of proliferative potential and an increase in cell size. Because HUVEC senescence in one strain (HlOl) has been characterized by the increase in the steady-state mRNA level for the signal-peptideless cytokine, interleukin (IL) la, we have examined young and senescent populations of five additional HUVEC strains (13605, H103, H928, H929, and H930) to determine whether the elevated levels of IL-la mRNA could be observed in all HUVEC strains. Consistent with the data from strain H101, strains H3605 and 1930 also exhibited a low steady-state level of the IL-la mRNA in young populations compared to elevated levels of IL-la mRNA in the senescent populations. However, three strains (H103, H928, and H929) did not exhibit reduced levels of IL-la mRNA in the young populations, and interestingly, strain H928, at times, expressed relatively high IL-la mRNA levels in the young populations. In addition, expression of the steady-state level of plainogen activator inhibitor 1 and cyclooxygenase 2 was elevated in senescent populations of all HUVEC strains examined, whereas young populations exhibited a low level of expression for these genes regardless of the IL-la mRNA level. Further, the level of the IL-la polypeptide was elevated in senescent HUVEC populations relative to young populations that expressed either a high or low level of the IL-la mRNA. We have also demonstrated that the elevated level of IL-la mRNA in the senescent population of strain H3605 may be regulated by mRNA stability; however, this mechanism does not apply to all the HUVEC strains examined in this study. Thus, we suggest that while mRNA levels of the IL-1-response genes for plasminogen activator inhibitor 1 and cyclooxygenase 2 are appropriate markers for HUVEC senescence, HUVEC strain-specific post-transcriptional mechanisms may exist to regulate the function of IL-la as a modifier of HUVEC senescence in vitro.

MiR-146a as marker of senescence-associated pro-inflammatory status in cells involved in vascular remodelling

“…We cannot exclude that contrasting results on miR-146a expression in senescent HUVEC cells could depend on the different strains used in previous investigations. In fact, a HUVEC strain-specific expression of inflammatory cytokines during in vitro senescence was previously reported, suggesting that young HUVECs of different strains could be characterised by different pro-inflammatory status, blunting the acquisition of a pro-inflammatory phenotype during replicative senescence (Garfinkel et al 1994). Another possibility for discrepancies could be due to the choice of different normalisers.…”

Redox Control of the Senescence Regulator Interleukin-1α and the Secretory Phenotype

“…(3)(4)(5)(6), and this elevated expression coincides with an increase in oxidation of the redox-sensitive fluorophore H 2 DCFDA (Fig. 1, A E, Western blot analysis of intracellular catalase after overnight incubation with 500 units/ml recombinant catalase added to cell culture medium.…”

“…However, senescent cells accumulate with age (1) and adopt a secretory phenotype that is causally linked to tissue degeneration (2). The senescence-associated (SA) 2 secretory phenotype (SASP) is regulated in large part by high level expression of IL-1␣ (3)(4)(5)(6). Suppression of IL-1␣ expression or its biological function can extend cellular life span and restrict SA gene expression, but the mechanism of this age-dependent induction is unknown.…”

Regulation of replicative senescence by insulin‐like growth factor‐binding protein 3 in human umbilical vein endothelial cells

“…This process has been proposed to be a typical model for biological aging (Cristofalo et al ., 2004) as well as a safeguard against cancer development by suppressing the transformation to immortal cells (Smith & Pereira-Smith, 1996). Like other normal diploid cells, human umbilical vein endothelial cells (HUVEC) enter a state of irreversible growth arrest (Garfinkel et al ., 1994;Wagner et al ., 2001) following a finite number of cell divisions in vitro . Senescent cells were known to promote aging phenotypes or age-related pathology through not only accumulation of nondividing senescence cells but also secretion of long-range, pleiotropic factors such as degradative enzymes, growth factors and inflammatory cytokines, thereby altering the tissue microenvironment (Campisi, 1998(Campisi, , 2005.…”