Abstract
Cyclic AMP promotes chronic expression of target genes mainly by protein kinase A-dependent activation of CREB transcription factor machineries in the metabolic tissues. Here, we wanted to elaborate whether CREB-regulated transcription factor (CRTC)2 and its negative regulator salt-inducible kinase (SIK)2 are involved in the transcriptional control of the metabolic pathway in adipocytes. SIK2 knockout (SIK2 KO) mice exhibited higher blood glucose levels that were associated with impaired glucose and insulin tolerance. Hypertriglyceridemia was apparent in SIK2 KO mice, mainly due to the increased lipolysis from white adipocytes and the decreased fatty acid uptake in the peripheral tissues. Investigation of white adipocytes revealed the increases in fat cell size and macrophage infiltration, which could be linked to the metabolic anomaly that is associated in these mice. Interestingly, SIK2 KO promoted the enhancement in the CRTC2-CREB transcriptional pathway in white adipocytes. SIK2 KO mice displayed increased expression of activating transcription factor (ATF)3 and subsequent downregulation of GLUT4 expression and reduction in high-molecular weight adiponectin levels in the plasma, leading to the reduced glucose uptake in the muscle and white adipocytes. The effect of SIK2-dependent regulation of adipocyte metabolism was further confirmed by in vitro cell cultures of 3T3 L1 adipocytes and the differentiated preadipocytes from the SIK2 or CRTC2 KO mice. Collectively, these data suggest that SIK2 is critical in regulating whole-body glucose metabolism primarily by controlling the CRTC2-CREB function of the white adipocytes.
| Original language | English |
|---|---|
| Pages (from-to) | 3659-3673 |
| Number of pages | 15 |
| Journal | Diabetes |
| Volume | 63 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - 2014 Jan 1 |
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SIK2 is critical in the regulation of lipid homeostasis and adipogenesis in vivo. / Park, Jinyoung; Yoon, Young Sil; Han, Hye Sook; Kim, Yong Hoon; Ogawa, Yoshihiro; Park, Keun Gyu; Lee, Chul Ho; Kim, Seong Tae; Koo, Seung-Hoi.
In: Diabetes, Vol. 63, No. 11, 01.01.2014, p. 3659-3673.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - SIK2 is critical in the regulation of lipid homeostasis and adipogenesis in vivo
AU - Park, Jinyoung
AU - Yoon, Young Sil
AU - Han, Hye Sook
AU - Kim, Yong Hoon
AU - Ogawa, Yoshihiro
AU - Park, Keun Gyu
AU - Lee, Chul Ho
AU - Kim, Seong Tae
AU - Koo, Seung-Hoi
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Cyclic AMP promotes chronic expression of target genes mainly by protein kinase A-dependent activation of CREB transcription factor machineries in the metabolic tissues. Here, we wanted to elaborate whether CREB-regulated transcription factor (CRTC)2 and its negative regulator salt-inducible kinase (SIK)2 are involved in the transcriptional control of the metabolic pathway in adipocytes. SIK2 knockout (SIK2 KO) mice exhibited higher blood glucose levels that were associated with impaired glucose and insulin tolerance. Hypertriglyceridemia was apparent in SIK2 KO mice, mainly due to the increased lipolysis from white adipocytes and the decreased fatty acid uptake in the peripheral tissues. Investigation of white adipocytes revealed the increases in fat cell size and macrophage infiltration, which could be linked to the metabolic anomaly that is associated in these mice. Interestingly, SIK2 KO promoted the enhancement in the CRTC2-CREB transcriptional pathway in white adipocytes. SIK2 KO mice displayed increased expression of activating transcription factor (ATF)3 and subsequent downregulation of GLUT4 expression and reduction in high-molecular weight adiponectin levels in the plasma, leading to the reduced glucose uptake in the muscle and white adipocytes. The effect of SIK2-dependent regulation of adipocyte metabolism was further confirmed by in vitro cell cultures of 3T3 L1 adipocytes and the differentiated preadipocytes from the SIK2 or CRTC2 KO mice. Collectively, these data suggest that SIK2 is critical in regulating whole-body glucose metabolism primarily by controlling the CRTC2-CREB function of the white adipocytes.
AB - Cyclic AMP promotes chronic expression of target genes mainly by protein kinase A-dependent activation of CREB transcription factor machineries in the metabolic tissues. Here, we wanted to elaborate whether CREB-regulated transcription factor (CRTC)2 and its negative regulator salt-inducible kinase (SIK)2 are involved in the transcriptional control of the metabolic pathway in adipocytes. SIK2 knockout (SIK2 KO) mice exhibited higher blood glucose levels that were associated with impaired glucose and insulin tolerance. Hypertriglyceridemia was apparent in SIK2 KO mice, mainly due to the increased lipolysis from white adipocytes and the decreased fatty acid uptake in the peripheral tissues. Investigation of white adipocytes revealed the increases in fat cell size and macrophage infiltration, which could be linked to the metabolic anomaly that is associated in these mice. Interestingly, SIK2 KO promoted the enhancement in the CRTC2-CREB transcriptional pathway in white adipocytes. SIK2 KO mice displayed increased expression of activating transcription factor (ATF)3 and subsequent downregulation of GLUT4 expression and reduction in high-molecular weight adiponectin levels in the plasma, leading to the reduced glucose uptake in the muscle and white adipocytes. The effect of SIK2-dependent regulation of adipocyte metabolism was further confirmed by in vitro cell cultures of 3T3 L1 adipocytes and the differentiated preadipocytes from the SIK2 or CRTC2 KO mice. Collectively, these data suggest that SIK2 is critical in regulating whole-body glucose metabolism primarily by controlling the CRTC2-CREB function of the white adipocytes.
UR - http://www.scopus.com/inward/record.url?scp=84908611789&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84908611789&partnerID=8YFLogxK
U2 - 10.2337/db13-1423
DO - 10.2337/db13-1423
M3 - Article
C2 - 24898145
AN - SCOPUS:84908611789
VL - 63
SP - 3659
EP - 3673
JO - Diabetes
JF - Diabetes
SN - 0012-1797
IS - 11
ER -