Biology:Senescence-associated beta-galactosidase

From HandWiki
Short description: Hypothetical hydrolase enzyme
galactosidase, beta 1
Identifiers
SymbolGLB1
Alt. symbolsSA-β-Gal
NCBI gene2720
HGNC4298
OMIM611458
RefSeqNM_000404
UniProtP16278
Other data
EC number3.2.1.23
LocusChr. 3 p22.3

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides only in senescent cells. Senescence-associated beta-galactosidase, along with p16Ink4A, is regarded to be a biomarker of cellular senescence.[1][2]

Its existence was proposed in 1995 by Dimri et al.[3] following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining. They proposed a cytochemical assay based on production of a blue-dyed precipitate that results from the cleavage of the chromogenic substrate X-Gal, which stains blue when cleaved by galactosidase. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.[4][5][6]

Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidase specifically in senescent cells.[7] Its expression is not required for senescence.[7] However, it remains as the most widely used biomarker for senescent and aging cells, because it is easy to detect and reliable both in situ and in vitro.

References

  1. ↑ "Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells". Aging 8 (7): 1294–1315. 2016. doi:10.18632/aging.100991. PMID 27391570. PMC 4993332. http://www.aging-us.com/article/XFECL8coa6th4i87b/text. 
  2. ↑ "p16(Ink4a) and senescence-associated β-galactosidase can be induced in macrophages as part of a reversible response to physiological stimuli". Aging (Albany NY) 9 (8): 1867–1884. 2017. doi:10.18632/aging.101268. PMID 28768895. PMC 5611982. http://www.aging-us.com/article/101268/text. 
  3. ↑ "A biomarker that identifies senescent human cells in culture and in aging skin in vivo". Proc. Natl. Acad. Sci. U.S.A. 92 (20): 9363–7. September 1995. doi:10.1073/pnas.92.20.9363. PMID 7568133. Bibcode: 1995PNAS...92.9363D. 
  4. ↑ "A quantitative chemiluminescent method for studying replicative and stress-induced premature senescence in cell cultures". Anal. Biochem. 372 (2): 198–203. January 2008. doi:10.1016/j.ab.2007.08.016. PMID 17920029. 
  5. ↑ "Quantitative assay of senescence-associated beta-galactosidase activity in mammalian cell extracts". Anal. Biochem. 343 (2): 329–34. August 2005. doi:10.1016/j.ab.2005.06.003. PMID 16004951. 
  6. ↑ "Methods to Detect Biomarkers of Cellular Senescence". Biological Aging. Methods in Molecular Biology. 371. Humana Press. 2007. pp. 21–31. doi:10.1007/978-1-59745-361-5_3. ISBN 978-1-58829-658-0. https://archive.org/details/biologicalagingm00toll/page/21. 
  7. ↑ 7.0 7.1 "Senescence-associated beta-galactosidase is lysosomal beta-galactosidase". Aging Cell 5 (2): 187–95. April 2006. doi:10.1111/j.1474-9726.2006.00199.x. PMID 16626397. 

Further reading

  • "The limitations and validities of senescence associated-beta-galactosidase activity as an aging marker for human foreskin fibroblast Hs68 cells". Exp. Gerontol. 40 (10): 813–9. October 2005. doi:10.1016/j.exger.2005.07.011. PMID 16154306. 


ar:هرم (فيزيولوجيا) ko:노화 ja:老化 pt:SA-beta-gal qu:Machuyay vi:Lão hoá zh:衰老



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