Tumor suppressor candidate 5 (TUSC5) is expressed in brown adipocytes.
Rat brain endothelial cell derived gene-1 (BEC-1) had considerable homology with tumor suppressor candidate 5 (TUSC5). TUSC5 was expressed abundantly, and its mRNA was inhibited by cold exposure in rat brown adipose tissue (BAT). In the present study, we investigated its regulatory mechanism using primary cultured rat brown preadipocytes (RBPA) and Zucker lean rats (ZL). We found that: (1) TUSC5 mRNA began to increase in a manner similar to C/EBP-alpha, PPAR-gamma, and adiponectin during differentiation in RBPA; (2) neither beta3-adrenoceptor agonist BRL 37344 nor dexamethasone affected TUSC5 mRNA in RBPA; (3) propranolol did not block the decrease of TUSC5 mRNA by cold exposure in ZL; (4) BRL 37344 did not influence TUSC5 mRNA in ZL; and (5) dexamethasone inhibited TUSC5 mRNA in a dose-dependent manner similar to UCP-1 in ZL. These data suggested that TUSC5 is involved in the differentiation, and its expression is regulated independently of the beta-adrenergic pathway in BAT.
Koide
Hisashi
H
Department of Clinical Cell Biology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Shibata
Takahisa
T
Yamada
Nobuko
N
Asaki
Toshiyuki
T
Nagao
Toshitaka
T
Yoshida
Tomohiko
T
Noguchi
Yoshihiko
Y
Tanaka
Tomoaki
T
Saito
Yasushi
Y
Tatsuno
Ichiro
I
D052437:Adipocytes, Brown / Q000166:cytology* / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000502:physiology; D007473:Ion Channels / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D051381:Rats; D011924:Rats, Zucker; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D000071256:Uncoupling Protein 1
D007473:Ion Channels; D024101:Mitochondrial Proteins; C517385:Trarg1 protein, rat; D025521:Tumor Suppressor Proteins; C000604373:Ucp1 protein, rat; D000071256:Uncoupling Protein 1