Crucial role of alkaline sphingomyelinase in sphingomyelin digestion: A study on the enzyme knockout mice.
(2010) In Journal of Lipid Research 52(4). p.771-781- Abstract
- Alkaline sphingomyelinase (alk-SMase) hydrolyses sphingomyelin (SM) to ceramide in the gut. To evaluate physiological importance of the enzyme, we generated alk-SMase knockout (KO) mice by Cre-LoxP system and studied SM digestion. Both wild type (WT) and the KO mice were fed 3H-palmitic acid labeled SM together with milk SM by gavage. The lipids in intestinal content, intestinal tissues, serum and liver were analysed by TLC. In KO mice, non-digested 3H-SM in the intestinal content increased by 6 fold and the formation of 3H-ceramide decreased markedly, resulting in 98% reduction of 3H-ceramide/3H-SM ratio 1 h after gavage. The absorbed 3H-palmitic acid portion was decreased by 95%. After three hours, a small increase in 3H-ceramide was... (More)
- Alkaline sphingomyelinase (alk-SMase) hydrolyses sphingomyelin (SM) to ceramide in the gut. To evaluate physiological importance of the enzyme, we generated alk-SMase knockout (KO) mice by Cre-LoxP system and studied SM digestion. Both wild type (WT) and the KO mice were fed 3H-palmitic acid labeled SM together with milk SM by gavage. The lipids in intestinal content, intestinal tissues, serum and liver were analysed by TLC. In KO mice, non-digested 3H-SM in the intestinal content increased by 6 fold and the formation of 3H-ceramide decreased markedly, resulting in 98% reduction of 3H-ceramide/3H-SM ratio 1 h after gavage. The absorbed 3H-palmitic acid portion was decreased by 95%. After three hours, a small increase in 3H-ceramide was identified in distal intestine in KO mice. In feces 3H-SM was increased by 243% and ceramide decreased by 74% in the KO mice. The KO mice also showed significantly decreased radioactivity in liver and serum. Furthermore alkaline phosphatase activity in the mucosa was reduced by 50%, and histological comparison of two female littermates preliminarily suggested mucosal hypertrophy in KO mice. The study provides definite proofs for crucial roles of alk-SMase in SM digestion and points to possible roles in regulating mucosal growth and alkaline phosphatase function. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1755883
- author
- Zhang, Yao LU ; Cheng, Yajun LU ; Hansen, Gert H ; Niels-Christiansen, Lise-Lotte ; Koentgen, Frank ; Ohlsson, Lena LU ; Nilsson, Åke LU and Duan, Rui-Dong LU
- organization
- publishing date
- 2010
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- NPP7, alkaline phosphatase, hypertrophy
- in
- Journal of Lipid Research
- volume
- 52
- issue
- 4
- pages
- 771 - 781
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:21177474
- wos:000288239300016
- scopus:79953322390
- pmid:21177474
- ISSN
- 1539-7262
- DOI
- 10.1194/jlr.M012880
- language
- English
- LU publication?
- yes
- id
- 26923b62-ebe5-4229-b1dd-3851dd24dd37 (old id 1755883)
- alternative location
- http://www.ncbi.nlm.nih.gov/pubmed/21177474?dopt=Abstract
- date added to LUP
- 2016-04-01 11:02:20
- date last changed
- 2024-01-07 06:56:47
@article{26923b62-ebe5-4229-b1dd-3851dd24dd37, abstract = {{Alkaline sphingomyelinase (alk-SMase) hydrolyses sphingomyelin (SM) to ceramide in the gut. To evaluate physiological importance of the enzyme, we generated alk-SMase knockout (KO) mice by Cre-LoxP system and studied SM digestion. Both wild type (WT) and the KO mice were fed 3H-palmitic acid labeled SM together with milk SM by gavage. The lipids in intestinal content, intestinal tissues, serum and liver were analysed by TLC. In KO mice, non-digested 3H-SM in the intestinal content increased by 6 fold and the formation of 3H-ceramide decreased markedly, resulting in 98% reduction of 3H-ceramide/3H-SM ratio 1 h after gavage. The absorbed 3H-palmitic acid portion was decreased by 95%. After three hours, a small increase in 3H-ceramide was identified in distal intestine in KO mice. In feces 3H-SM was increased by 243% and ceramide decreased by 74% in the KO mice. The KO mice also showed significantly decreased radioactivity in liver and serum. Furthermore alkaline phosphatase activity in the mucosa was reduced by 50%, and histological comparison of two female littermates preliminarily suggested mucosal hypertrophy in KO mice. The study provides definite proofs for crucial roles of alk-SMase in SM digestion and points to possible roles in regulating mucosal growth and alkaline phosphatase function.}}, author = {{Zhang, Yao and Cheng, Yajun and Hansen, Gert H and Niels-Christiansen, Lise-Lotte and Koentgen, Frank and Ohlsson, Lena and Nilsson, Åke and Duan, Rui-Dong}}, issn = {{1539-7262}}, keywords = {{NPP7; alkaline phosphatase; hypertrophy}}, language = {{eng}}, number = {{4}}, pages = {{771--781}}, publisher = {{American Society for Biochemistry and Molecular Biology}}, series = {{Journal of Lipid Research}}, title = {{Crucial role of alkaline sphingomyelinase in sphingomyelin digestion: A study on the enzyme knockout mice.}}, url = {{https://lup.lub.lu.se/search/files/2331004/1766780.pdf}}, doi = {{10.1194/jlr.M012880}}, volume = {{52}}, year = {{2010}}, }