MicroRNA-30 family members regulate calcium/calcineurin signaling in podocytes
JOURNAL OF CLINICAL INVESTIGATION
Authors: Wu, Junnan; Zheng, Chunxia; Wang, Xiao; Yun, Shifeng; Zhao, Yue; Liu, Lin; Lu, Yuqiu; Ye, Yuting; Zhu, Xiaodong; Zhang, Changming; Shi, Shaolin; Liu, Zhihong
Abstract
Calcium/calcineurin signaling is critical for normal cellular physiology. Abnormalities in this pathway cause many diseases, including podocytopathy; therefore, understanding the mechanisms that underlie the regulation of calcium/calcineurin signaling is essential. Here, we showed that critical components of calcium/calcineurin signaling, including TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3, are the targets of the microRNA-30 family (miR-30s). We found that these 5 genes are highly expressed as mRNA, but the level of the proteins is low in normal podocytes. Conversely, protein levels were markedly elevated in podocytes from rats treated with puromycin aminonucleoside (PAN) and from patients with focal segmental glomerulosclerosis (FSGS). In both FSGS patients and PAN-treated rats, miR-30s were downregulated in podocytes. In cultured podocytes, PAN or a miR-30 sponge increased TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3 expression; calcium influx; intracellular Ca2+ concentration; and calcineurin activity. Moreover, NFATC3 nuclear translocation, synaptopodin degradation, integrin beta 3 (ITGB3) activation, and actin fiber loss, which are downstream of calcium/calcineurin signaling, were induced by miR-30 reduction but blocked by the calcineurin inhibitor FK506. Podocyte-specific expression of the miR-30 sponge in mice increased calcium/calcineurin pathway component protein expression and calcineurin activity. The mice developed podocyte foot process effacement and proteinuria, which were prevented by FK506. miR-30s also regulated calcium/calcineurin signaling in cardiomyocytes. Together, our results identify miR-30s as essential regulators of calcium/calcineurin signaling.
Heat shock transcription factor 1-associated expression of slow myosin heavy chain in mouse soleus muscle in response to unloading with or without reloading
ACTA PHYSIOLOGICA
Authors: Yokoyama, S.; Ohno, Y.; Egawa, T.; Yasuhara, K.; Nakai, A.; Sugiura, T.; Ohira, Y.; Yoshioka, T.; Okita, M.; Origuchi, T.; Goto, K.
Abstract
AimThe effects of heat shock transcription factor 1 (HSF1) deficiency on the fibre type composition and the expression level of nuclear factor of activated T cells (NFAT) family members (NFATc1, NFATc2, NFATc3 and NFATc4), phosphorylated glycogen synthase kinase 3 (p-GSK3) and p-GSK3, microRNA-208b (miR-208b), miR-499 and slow myosin heavy chain (MyHC) mRNAs (Myh7 and Myh7b) of antigravitational soleus muscle in response to unloading with or without reloading were investigated. MethodsHSF1-null and wild-type mice were subjected to continuous 2-week hindlimb suspension followed by 2- or 4-week ambulation recovery. ResultsIn wild-type mice, the relative population of slow type I fibres, the expression level of NFATc2, p-GSK3 ( and ), miR-208b, miR-499 and slow MyHC mRNAs (Myh7 and Myh7b) were all decreased with hindlimb suspension, but recovered after it. Significant interactions between train and time (the relative population of slow type I fibres; P=0.01, the expression level of NFATc2; P=0.001, p-GSK; P=0.009, miR-208b; P=0.002, miR-499; P=0.04) suggested that these responses were suppressed in HSF1-null mice. ConclusionHSF1 may be a molecule in the regulation of the expression of slow MyHC as well as miR-208b, miR-499, NFATc2 and p-GSK3 ( and ) in mouse soleus muscle.