Opioid receptors and opioid peptides in the cardiomyogenesis of mouse embryonic stem cells

Abstract

The stimulation of myocardium repair is restricted due to the limited understanding of heart regeneration. Interestingly, endogenous opioid peptides such as dynorphins and enkephalins are suggested to support this process. However, the mechanism—whether through the stimulation of the regenerative capacity of cardiac stem cells or through effects on other cell types in the heart—is still not completely understood. Thus, a model of the spontaneous cardiomyogenic differentiation of mouse embryonic stem (mES) cells via the formation of embryoid bodies was used to describe changes in the expression and localization of opioid receptors within cells during the differentiation process and the potential of the selected opioid peptides, dynorphin A and B, and methionin‐enkephalins and leucin‐enkephalins, to modulate cardiomyogenic differentiation in vitro. The expressions of both κ‐ and δ‐opioid receptors significantly increased during mES cell differentiation. Moreover, their primary colocalization with the nucleus was followed by their growing presence on the cytoplasmic membrane with increasing mES cell differentiation status. Interestingly, dynorphin B enhanced the downregulation gene expression of Oct4 characteristic of the pluripotent phenotype. Further, dynorphin B also increased cardiomyocyte‐specific Nkx2.5 gene expression. However, neither dynorphin A nor methionin‐enkephalins and leucin‐enkephalins exhibited any significant effects on the course of mES cell differentiation. In conclusion, despite the increased expression of opioid receptors and some enhancement of mES cell differentiation by dynorphin B, the overall data do not support the notion that opioid peptides have a significant potential to promote the spontaneous cardiomyogenesis of mES cells in vitro.

Conventional Echocardiography and Two-Dimensional Speckle Tracking in Healthy Sevoflurane-Anesthetized Dogs Undergoing Continuous Rate Infusion of Nalbuphine

“…ese findings demonstrate clearly that nalbuphine at 0.4 mg/kg/h does not influence systolic function of healthy dogs anesthetized with sevoflurane. Previous studies showed that mammalian myocardium can be directly influenced by opioids, given the presence of opioid receptors μ, σ and κ [3][4][5]. Kappa receptors seem to be the main regulators of cardiac function.…”

“…Some studies have shown that mammalian myocardium has opioid receptors μ, σ, and κ [3][4][5]. One of the most important myocardium opioid receptors is the kappa.…”

Nitro-Oleic Acid Inhibits Stemness Maintenance and Enhances Neural Differentiation of Mouse Embryonic Stem Cells via STAT3 Signaling

“…The mESC line R1 (ATCC ® SCRC-1011™) was cultivated as described previously [15]. Cells were routinely tested for the presence of Mycoplasma contamination (RT-qPCR).…”

“…A total of 20 µg of protein lysates were loaded on SDSpolyacrylamide gel. Immunoblot analyses were performed as presented previously [15]. The following primary antibodies were used to detect particular proteins: rabbit anti-OCT-3/4 (#9081, 1:1000) from Santa Cruz Biotechnology (Dallas, TX, USA), rabbit anti-NANOG (#8822, 1:1000), rabbit anti-SOX2 (#23064, 1:1000), rabbit anti-phospho-STAT3 (#9145, Tyr705, 1:2000), mouse anti-STAT3 (#9139, 1:1000), anti-total/phospho-ERK1/2 (#4696, 1:2000/#4377, 1:1000), anti-total/phospho-AKT (#2920, 1:2000/#4056, 1:1000) (all from Cell Signaling Technology, Danvers, MA, USA), mouse anti-Vinculin (V9264, 1:10000; Sigma-Aldrich, St. Louis, MO, USA).…”

“…In recent years, there has been an increasing interest in deciphering the mechanisms responsible for the regulation of ESC pluripotency and differentiation, especially due to the possible use of stem cells in the therapy [13][14][15]. Many of these studies were focused on the direct or indirect regulation of STAT3 signaling pathway [9,10].…”