MicroRNA-30 family members regulate calcium/calcineurin signaling in podocytes

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 β3 (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.

Calcineurin inhibitors cyclosporin A and tacrolimus protect against podocyte injury induced by puromycin aminonucleoside in rodent models

“…In the present study, we found CaN inhibitors (CsA and FK506) reduced the 24-h urinary protein and ameliorated the serum albumin, triglyceride, and cholesterol abnormalities in PAN-treated SD rats, as well as reducing the foot-process effacement and recovering the expression of podocyte cytoskeleton markers synaptopodin and podocin, implying that CsA and FK506 reduced proteinuria by protecting podocytes in PAN induced MCD model. Furthermore, in agreement with previous findings6262728, we also found that CsA and FK506 directly protect podocyte cytoskeleton and restore the expression of synaptopodin and podocin in cultured mouse podocytes. Moreover, podocyte functional assay also showed increased cell viability and decreased cell motility in CsA and FK506 preincubated podocytes.…”

Identification, Confirmation, and Replication of Novel Urinary MicroRNA Biomarkers in Lupus Nephritis and Diabetic Nephropathy

“…miR-30c-5p was associated with proteinuria and cellular crescents in LN. The members of the miR-30 family are important regulators of podocyte homeostasis and pathogenesis abundantly expressed in the kidney where their deregulation is associated with podocyte injury as described in patients with primary focal segmental glomerulosclerosis (35, 36). Members of this family have a similar sequence, but their genes are localized on different chromosomes, making a different gene-expression pattern possible, depending on different stimuli (37).…”

Primary focal segmental glomerulosclerosis: miRNAs and targeted therapies

“…It is elevated in patients with FSGS and results in proteinuria, podocyte flattening and loss of foot process architecture in a mouse model . In addition, the miRNA‐30 family seems to be of importance, as it was described to be upregulated in several independent cohorts . Moreover, miR‐10 , miR‐125b, miR‐186 , miR‐192, miR‐205 , miR‐196a and miR‐490 seem to be promising candidates as markers in FSGS (Table ).…”

“…Downstream cytoplasmic nuclear factor of activated T‐cell (NFATC) family members are dephosphorylated by activated calcineurin. In normal podocytes, the mRNA levels of TRPC6, PPP3CA, PPP3CB, PPP3R1 and NFATC3 are highly expressed but protein levels are low . In podocytes of PAN‐treated rats, the protein levels of these proteins were upregulated and this upregulation was prevented by exogenous miR‐30a or glucocorticoids .…”