Bone morphogenetic protein 4 promotes the differentiation of Tbx18‑positive epicardial progenitor cells to pacemaker‑like cells

Abstract

Clarifying the mechanisms via which pacemaker- like cells are generated is critical for identifying novel targets for arrhythmia-associated disorders and constructing pacemakers with the ability to adapt to physiological requirements. T-box 18 (Tbx18)+ epicardial progenitor cells (EPCs) have the potential to differentiate into pacemaker cells. Although bone morphogenetic protein 4 (Bmp4) is likely to contribute, its role and regulatory mechanisms in the differentiation of Tbx18+ EPCs into pacemaker-like cells have remained to be fully elucidated. In the present study, the association between Bmp4, GATA binding protein 4 (Gata4) and hyperpolarization- activated cyclic nucleotide gated potassium channel 4 (Hcn4) to regulate NK2 homeobox 5 (Nkx2.5), which is known to be required for the differentiation of Tbx18+ EPCs into pacemaker-like cells, was assessed. Tbx18+ EPCs were isolated from Tbx18:Cre/Rosa26Renhanced yellow fluorescence protein (EYFP) murine embryos at embryonic day 11.5 and divided into the following four treatment groups: Control, Bmp4, Bmp4+LDN193189 (a Bmp inhibitor) and LDN193189. In vitro Bmp4 promoted the expression of Hcn4 in Tbx18+ EPCs via lineage tracing of Tbx18:Cre/Rosa26REYFP mice, which was likely due to upregulation of Gata4 expression. Gata4 knockdown experiments were then performed using the following five treatment groups: Control, control small interfering RNA (siRNA), Bmp4, Bmp4+siRNA targeting Gata4 (siGata4) and siGata4 group. Knockdown of Gata4 caused a downregulation of Hcn4 and an upregulation of Nkx2.5, but had no effect on Bmp4 expression. In conclusion, it was indicated that in Tbx18+ EPCs, the expression of Nkx2.5 was regulated by Bmp4 via Gata4. Taken together, these results provide important information on regulatory networks of pacemaker cell differentiation and may serve as a basis for further studies.

NRF-2/HO-1 Pathway-Mediated SHOX2 Activation Is a Key Switch for Heart Rate Acceleration by Yixin-Fumai Granules

“…Moreover, the RT-qPCR, Western blotting, and immunofluorescence staining results of HL-1 cells indicated that YXFMs could considerably promote SHOX2, BMP4, and CACNA1G expression in Shox2 -silenced HL-1 cells, while increasing GATA4 expression and reducing NKX2-5 expression. The activation of GATA4, the downstream regulatory target of BMP4, inhibits NKX2-5 expression and ultimately promotes the expression of pacing-related ion channels including T-type calcium channel expression and prevents P cell transformation into working cardiomyocytes [ 14 , 20 ].…”

“…Short stature homeobox 2 (SHOX2), a transcription regulator highly expressed in the SAN, inhibits NK2 homeobox 5 (NKX2-5) expression by regulating the downstream bone morphogenetic protein 4 (BMP4) and GATA binding protein 4 (GATA4) and plays a key role in SAN development and differentiation [13][14][15]. In a study, Shox2-knockout mice died during pregnancy due to cardiac conduction system defects, including SAN and valve sinus hypoplasia accompanied by the loss of Tbox transcription factor 3 and HCN4 expression and ectopic natriuretic peptide A, connexin 40, and NKX2-5 expression in the SAN; this suggested that in Shox2-knockout mice, SAN cells cannot differentiate into P cells but into working cardiomyocytes [15][16][17].…”

Genetic analyses of the QT interval and its components in over 250K individuals identifies new loci and pathways affecting ventricular depolarization and repolarization

“…5). These include candidate genes encoding transcription factors (or their regulators) with roles in cellular proliferation and cardiac conduction system development (ID2, PRDM6 and PALLD) [68][69][70][71] . Gene-sets were also enriched in connective tissues and cell-types.…”

Bioactive Lipid O-cyclic phytosphingosine-1-phosphate Promotes Differentiation of Human Embryonic Stem Cells into Cardiomyocytes via ALK3/BMPR Signaling

“…LDN-193189 is a BMP type I receptor kinase inhibitor that can effectively inhibit the BMP receptor-mediated downstream signaling [47,48]. LDN treatment during CM generation effectively blocked p-SMAD1/5/8 expression, resulting in the complete inhibition of CM differentiation, which could not be rescued even by the treatment with cP1P (Figure 4C-E, Supplementary Videos S7 and S8).…”