Acta Pharmacologica Sinica (2009) 30: 1454–1461; doi: 10.1038/aps.2009.136

Acta Pharmacologica Sinica (2009) 30: 1454–1461; doi: 10.1038/aps.2009.136; published online 14 Sep 2009

Original Article

Increase in sphingolipid catabolic enzyme activity during aging

Santosh J SACKET¹, Hae-young CHUNG², Fumikazu OKAJIMA³, Dong-soon IM^1,*

Laboratories of ¹Pharmacology and ²Biochemistry, College of Pharmacy (BK21 Project) and Longevity Institute of Life Science and Technology, Pusan National University, Busan 609-735, Republic of Korea; ³Labotatory of Signal Transduction, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371, Japan

Aim: To understand the contribution of sphingolipid metabolism and its metabolites to development and aging.

Methods: A systemic analysis on the changes in activity of sphingolipid metabolic enzymes in kidney, liver and brain tissues during development and aging was conducted. The study was conducted using tissues from 1-day-old to 720-day-old rats.

Results: Catabolic enzyme activities as well as the level of sphingomyelinase (SMase) and ceramidase (CDase) were higher than that of anabolic enzyme activities, sphingomyelin synthase and ceramide synthase. This suggested an accumulation of ceramide and sphingosine during development and aging. The liver showed the highest neutral-SMase activity among the tested enzymes while the kidney and brain exhibited higher neutral-SMase and ceramidase activities, indicating a high production of ceramide in liver and ceramide/sphingosine in the kidney and brain. The activities of sphingolipid metabolic enzymes were significantly elevated in all tested tissues during development and aging, although the onset of significant increase in activity varied on the tissue and enzyme type. During aging, 18 out of 21 enzyme activities were further increased on day 720 compared to day 180.

Conclusion: Differential increases in sphingolipid metabolic enzyme activities suggest that sphingolipids including ceramide and sphingosine might play important and dynamic roles in proliferation, differentiation and apoptosis during development and aging.

Keywords: aging; sphingolipid; metabolism; sphingomyelinase; ceramidase; sphingomyelin synthase; ceramide synthase

This work was supported for two years by Pusan National University Research Grant.

* To whom correspondence should be addressed.
Email imds@pusan.ac.kr
Received 2009-05-27 Accepted 2009-08-07

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