Abstract
Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca2+ entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-β1 (TGF-β1)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-β1 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 µM), a classical activator of store-operated Ca2+ channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-β1 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La3+; 5 µM) and GSK-7975A (10 µM), both of which are selective blockers of store-operated Ca2+ channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca2+ channels, significantly augmented TGF-β1-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-β1-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-β1/Smad3 signaling pathway.
| Original language | English |
|---|---|
| Pages (from-to) | F729-F739 |
| Journal | American Journal of Physiology - Renal Physiology |
| Volume | 313 |
| Issue number | 3 |
| DOIs | |
| State | Published - 11 Sep 2017 |
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Keywords
- Mesangial cells
- Orai1
- Smad3
- Store-operated Ca entry
- Transforming growth factor-β1
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}
Store-operated calcium entry suppressed the TGF-β1/Smad3 signaling pathway in glomerular mesangial cells. / Chaudhari, Sarika; Li, Weizu; Wang, Yanxia; Jiang, Hui; Ma, Yuhong; Davis, Mark E.; Zuckerman, Jonathan E.; Ma, Rong.
In: American Journal of Physiology - Renal Physiology, Vol. 313, No. 3, 11.09.2017, p. F729-F739.Research output: Contribution to journal › Article
TY - JOUR
T1 - Store-operated calcium entry suppressed the TGF-β1/Smad3 signaling pathway in glomerular mesangial cells
AU - Chaudhari, Sarika
AU - Li, Weizu
AU - Wang, Yanxia
AU - Jiang, Hui
AU - Ma, Yuhong
AU - Davis, Mark E.
AU - Zuckerman, Jonathan E.
AU - Ma, Rong
PY - 2017/9/11
Y1 - 2017/9/11
N2 - Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca2+ entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-β1 (TGF-β1)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-β1 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 µM), a classical activator of store-operated Ca2+ channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-β1 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La3+; 5 µM) and GSK-7975A (10 µM), both of which are selective blockers of store-operated Ca2+ channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca2+ channels, significantly augmented TGF-β1-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-β1-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-β1/Smad3 signaling pathway.
AB - Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca2+ entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-β1 (TGF-β1)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-β1 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 µM), a classical activator of store-operated Ca2+ channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-β1 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La3+; 5 µM) and GSK-7975A (10 µM), both of which are selective blockers of store-operated Ca2+ channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca2+ channels, significantly augmented TGF-β1-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-β1-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-β1/Smad3 signaling pathway.
KW - Mesangial cells
KW - Orai1
KW - Smad3
KW - Store-operated Ca entry
KW - Transforming growth factor-β1
UR - http://www.scopus.com/inward/record.url?scp=85029351234&partnerID=8YFLogxK
U2 - 10.1152/ajprenal.00483.2016
DO - 10.1152/ajprenal.00483.2016
M3 - Article
C2 - 28637791
AN - SCOPUS:85029351234
VL - 313
SP - F729-F739
JO - American Journal of Physiology - Renal Physiology
JF - American Journal of Physiology - Renal Physiology
SN - 0363-6127
IS - 3
ER -