Impaired ATP6V0A2 expression contributes to Golgi dispersion and glycosylation changes in senescent cells

Abstract

Many genes and signaling pathways have been found to be involved in cellular senescence program. In the present study, we have identified 16 senescence-associated genes by differential proteomic analysis of the normal human diploid fibroblast cell line, TIG-1, and focused on ATP6V0A2. The aim of this study is to clarify the role of ATP6V0A2, the causal gene for ARCL2, a syndrome of abnormal glycosylation and impaired Golgi trafficking, in cellular senescence program. Here we showed that ATP6V0A2 is critical for cellular senescence; impaired expression of ATP6V0A2 disperses the Golgi structure and triggers senescence, suggesting that ATP6V0A2 mediates these processes. FITC-lectin staining and glycoblotting revealed significantly different glycosylation structures in presenescent (young) and senescent (old) TIG-1 cells; reducing ATP6V0A2 expression in young TIG-1 cells yielded structures similar to those in old TIG-1 cells. Our results suggest that senescence-associated impaired expression of ATP6V0A2 triggers changes in Golgi structure and glycosylation in old TIG-1 cells, which demonstrates a role of ATP6V0A2 in cellular senescence program.

Mammary epithelium‐specific inactivation of V‐ATPase reduces stiffness of extracellular matrix and enhances metastasis of breast cancer

“…Loss of Oglycosylation in epithelial cells reduces the secretion of basement membrane collagen protein that affects ECM composition in submandibular gland in mice (Tian et al, 2012). Further, upon inhibition of V-ATPase function, Golgi pH and structure are disrupted and glycosyltransferases are relocated from Golgi to early endosomes or plasma membranes, resulting in glycosylation changes (Hucthagowder et al, 2009;Kellokumpu et al, 2002;Udono et al, 2015). Our results are consistent with these studies as we found a similar glycosylation and compositional defects in ECM and dispersed Golgi morphology in mammary epithelial cells of a2V fl/fl MMTV Cre mice breast tissues.…”

“…Golgi morphology and defective glycosylation in mammary epithelial cells Next, we examined how the deletion of a2V leads to a low production of ECM proteins. a2V is present on Golgi membrane and disruption of a2V functions leads to deformation in Golgi structure (Axelsson et al, 2001;Udono et al, 2015). We evaluated Golgi morphology in mammary epithelial cells of breast tissues from a2V fl/fl MMTV Cre mice by staining for giantin, which is a Golgi membrane protein.…”

“…Neutralization of Golgi pH causes relocation of glycosyltransferase enzymes from Golgi to endosomes or plasma membrane causing protein glycosylationrelated changes in cells (Axelsson et al, 2001;Udono et al, 2015). Therefore, we evaluated any change in the distribution of GL25D2, a galactosyltransferase that glycosylates collagen IV in Golgi, as a possible factor for glycosylation irregularities in a2V fl/ fl MMTV Cre mice.…”

Replicative senescence of human dermal fibroblasts affects structural and functional aspects of the Golgi apparatus

“…Alterations of this important post‐translational event are also described in some progeroid syndromes and age‐associated pathologies . Moreover, secretion and glycosylation modifications have also been reported in senescent skin cells . Changes in protein secretion have been observed during skin ageing resulting in a specific secretome, named skin ageing–associated secreted proteins (SAASP), which are produced by dermal fibroblasts obtained from old donors .…”

“…The structure of the Golgi apparatus undergoes changes during biological processes, including secretion, mitosis, apoptosis and age‐related diseases, including cancer or Alzheimer pathologies . Alterations of the Golgi morphology have been reported in the mouse brain during ageing and in senescent human cell lines …”