Biology:Senescence-associated beta-galactosidase

From HandWiki
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. 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.[citation needed] Reversal of senescence of human chondrocytes taken from patients undergoing total knee arthroplasty in in vitro conditions through tissue engineering reported along with correlating evidence of P16 and P21 biomarkers reiterates this phenomenon.[8]

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. 
  8. ↑ "Reversal of senescence-associated beta-galactosidase expression during in vitro three-dimensional tissue-engineering of human chondrocytes in a polymer scaffold | Scientific Reports". https://doi.org/10.1038/s41598-021-93607-9. 

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. 




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