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Shimozawa, N.

Publications and source records attributed to Shimozawa, N..

2 recordsLinked to original sources

Zebrafish model of human Zellweger syndrome reveals organ specific accumulation of distinct fatty acid species and widespread gene expression changes

In Zellweger syndrome (ZS), lack of peroxisome function causes physiological and developmental abnormalities in many organs such as the brain, liver, muscles, and kidneys, but little is known about the exact pathogenic mechanism. By disrupting the zebrafish pex2 gene, we established a disease model for ZS and found that it exhibits a pathological condition and metabolic failures similar to that of human patients. By comprehensive analysis of fatty acid profile, we found organ specific accumulation and reduction of distinct fatty acid species such as an accumulation of ultra-very-long-chain polyunsturated fatty acids (ultra-VLCPUFAs) in the brain of pex2 mutant fish. Transcriptome analysis using microarray also revealed mutant-specific gene expression changes that might lead to the symptom, which include reduction of crystallin, troponin, parvalbumin, and fatty acid metabolic genes. Our data indicated that the loss of peroxisome results in widespread metabolic and gene expression changes beyond the causative peroxisomal function. These results suggest the genetic and metabolic basis of the pathology of this devastating human disease.

developmental biology↗

A method to determine the double bond position in unsaturated fatty acids by solvent plasmatization using liquid chromatography-mass spectrometry

Fatty acids (FAs) are the central components of life: they constitute biological membranes in the form of lipid, act as signaling molecules, and are used as energy sources. FAs are classified according to their chain lengths and the number and position of carbon-carbon double bond, and their physiological character is largely defined by these structural properties. Determination of the precise structural properties is crucial for characterizing FAs, but pinpointing the exact position of carbon-carbon double bond in FA molecules is challenging. Herein, a new analytical method is reported for determining the double bond position of mono- and poly-unsaturated FAs using liquid chromatography-mass spectrometry (LC-MS) coupled with solvent plasmatization. With the aid of plasma on ESI capirally, epoxidation or peroxidation of carbon-carbon double bond in FAs is facilitated. Subsequently, molecular fragmentation occurs at or beside the epoxidized or peroxidized double bond via collision-induced dissociation (CID), and the position of the double bond is elucidated. In this method, FAs are separated by LC, modified by plasma, fragmented via CID, and detected using a time-of-flight mass spectrometer in a seamless manner such that the FA composition in a mixture can be determined. Our method enables thorough characterization of FA species with distinguishing multiple isomers, and therefore can uncover the true diversity of FAs for their application in food, health, and medical sciences.

biochemistry↗