Senescent human hepatocytes express a unique secretory phenotype and promote macrophage migration.
World J Gastroenterol
; 20(47): 17851-62, 2014 Dec 21.
Article
en En
| MEDLINE
| ID: mdl-25548483
ABSTRACT
AIM:
To develop a model of stress-induced senescence to study the hepatocyte senescence associated secretory phenotype (SASP).METHODS:
Hydrogen peroxide treatment was used to induce senescence in the human HepG2 hepatocyte cell line. Senescence was confirmed by cytochemical staining for a panel of markers including Ki67, p21, heterochromatin protein 1ß, and senescence-associated-ß-galactosidase activity. Senescent hepatocytes were characterised by gene expression arrays and quantitative polymerase chain reaction (qPCR), and conditioned media was used in proteomic analyses, a human chemokine protein array, and cell migration assays to characterise the composition and function of the hepatocyte SASP.RESULTS:
Senescent hepatocytes induced classical markers of senescence (p21, heterochromatin protein 1ß, and senescence-associated-ß-galactosidase activity); and downregulated the proliferation marker, Ki67. Hepatocyte senescence induced a 4.6-fold increase in total secreted protein (P = 0.06) without major alterations in the protein profile. Senescence-induced genes were identified by microarray (Benjamini Hochberg-corrected P < 0.05); and, consistent with the increase in secreted protein, gene ontology analysis revealed a significant enrichment of secreted proteins among inducible genes. The hepatocyte SASP included characteristic factors such as interleukin (IL)-8 and IL-6, as well as novel components such as SAA4, IL-32 and Fibrinogen, which were validated by qPCR and/or chemokine protein array. Senescent hepatocyte-conditioned medium elicited migration of inflammatory (granulocyte-macrophage colony stimulating factor, GM-CSF-derived), but not non-inflammatory (CSF-1-derived) human macrophages (P = 0.022), which could contribute to a pro-inflammatory microenvironment in vivo, or facilitate the clearance of senescent cells.CONCLUSION:
Our novel model of hepatocyte senescence provides insights into mechanisms by which senescent hepatocytes may promote chronic liver disease pathogenesis.Palabras clave
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Quimiotaxis
/
Senescencia Celular
/
Comunicación Paracrina
/
Hepatocitos
/
Macrófagos
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
World J Gastroenterol
Asunto de la revista:
GASTROENTEROLOGIA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Australia