Control of cytokinesis by β-adrenergic receptors indicates an approach for regulating cardiomyocyte endowment.
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ABSTRACT:
SUBMITTER: Liu H
PROVIDER: S-EPMC8132604 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:OBJECTIVES:Induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a promising source of cells for regenerative heart disease therapies, but progress towards their use has been limited by their low differentiation efficiency and high cellular heterogeneity. Previous studies have demonstrated expression of adrenergic receptors (ARs) in stem cells after differentiation; however, roles of ARs in fate specification of stem cells, particularly in cardiomyocyte differentiation and development, have not been characterized. MATERIALS AND METHODS:Murine-induced pluripotent stem cells (miPSCs) were cultured in hanging drops to form embryoid bodies, cells of which were then differentiated into cardiomyocytes. To determine whether ARs regulated miPSC differentiation into cardiac lineages, effects of the AR agonist, epinephrine (EPI), on miPSC differentiation and underlying signalling mechanisms, were evaluated. RESULTS:Treatment with EPI, robustly enhanced miPSC cardiac differentiation, as indicated by increased expression levels of cardiac-specific markers, GATA4, Nkx2.5 and Tnnt2. Although ?-AR signalling is the foremost signalling pathway in cardiomyocytes, EPI-enhanced cardiac differentiation depended more on ?-AR signalling than ?-AR signalling. In addition, selective activation of ?1 -AR signalling with specific agonists induced vigorous cardiomyocyte differentiation, whereas selective activation of ?2 - or ?-AR signalling induced no or less differentiation, respectively. EPI- and ?1 -AR-dependent cardiomyocyte differentiation from miPSCs occurred through specific promotion of CPC proliferation via the MEK-ERK1/2 pathway and regulation of miPS cell-cycle progression. CONCLUSIONS:These results demonstrate that activation of ARs, particularly of ?1 -ARs, promoted miPSC differentiation into cardiac lineages via MEK-ERK1/2 signalling.
| S-EPMC6529101 | biostudies-literature
Project description:Millions of patients suffer from asthma worldwide. However, the first-line drugs used to treat asthma, namely, the beta-adrenergic receptors agonists (β-agonists), are not recommended for use as monotherapy because of their severe dose-related side effects. This limitation has prompted the search for new therapies, which can be used in conjunction with β--agonists so that lower doses can be administered. Sinigrin is a major compound found in many antiasthmatic medicinal plants. In this study, we explored the antiasthmatic activity of sinigrin when used in combination with β-agonists and its underlying mechanism. Sinigrin enhanced the asthma-relieving effects of isoproterenol and reduced the effective isoproterenol dose in an acute-asthma model in guinea pigs. Mechanistically, sinigrin enhanced the cAMP levels induced by β-agonists by inhibiting PDE4. The resulting increase in cAMP levels stimulated the activity of the downstream effector protein kinase A, which would be expected to ultimately induce the relaxation of airway smooth muscle. In conclusion, sinigrin enhances the asthma-relieving effects of β-agonists by regulating the cAMP signaling pathway and represents a potential add-on drug to β-agonists for the treatment of asthma.
| S-EPMC7251054 | biostudies-literature
Project description:The mechanism that leads to a decrease in ?1-adrenergic receptor (?1AR) expression in the failing heart remains uncertain. This study shows that cardiomyocyte ?1AR expression and isoproterenol responsiveness decrease in response to oxidative stress. Studies of mechanisms show that the redox-dependent decrease in ?1AR expression is uniquely prevented by carvedilol and not other ?AR ligands. Carvedilol also promotes the accumulation of N-terminally truncated ?1ARs that confer protection against doxorubicin-induced apoptosis in association with activation of protein kinase B. The redox-induced molecular controls for cardiomyocyte ?1ARs and pharmacologic properties of carvedilol identified in this study have important clinical and therapeutic implications.
| S-EPMC6116783 | biostudies-literature
Project description:Keratinocyte migration into skin wounds is the step of the healing process that correlates with the wound closure rate. Keratinocyte migration, and wound epithelialization are decreased when beta 2-adrenergic receptors (B2AR) are activated by 1 μM epinephrine/adrenaline, resulting in delayed wound healing in human and mouse skin. In the present study, we found paradoxically, that in a subset of keratinocyte strains exposure to low concentrations of epinephrine (0.1 nM) increased, rather than decreased, their migratory rate. We find that both the alpha- and the beta-adrenergic receptors are expressed in human keratinocytes, and expression of alpha-2 AR subtypes demonstrated for the first time. Therefore, we tested if the alpha-AR could be modulating the increased migratory response observed in these cell strains. By using specific inhibitors to alpha-AR, we demonstrated that blocking A2B-AR could reverse the rapid cell migration induced by the 0.1 nM epinephrine. Phosphorylation of ERK was elevated after 1-10 minutes of the low epinephrine treatment and the A2B-AR inhibitor blocked the ERK phosphorylation. The results suggest that both the A2B-AR and B2AR mediate keratinocyte migration, in which with a low level of epinephrine treatment, A2B-AR could alter the B2AR signals and regulate the migration rate.
| S-EPMC8253387 | biostudies-literature
Project description:Beta-Adrenergic receptors from basal membranes of human placenta were purified from digitonin extracts by sequential rounds of affinity chromatography, hydrophobic chromatography, ion-exchange chromatography and steric-exclusion h.p.l.c. Basal membranes display both beta 1- and beta 2-adrenergic receptors, in the ratio 65:35. Affinity chromatography, hydrophobic chromatography on heptylamine-Sepharose and ion-exchange chromatography on DEAE-Sephacel removed most of the contaminating proteins, and final purification of the receptor to apparent homogeneity was achieved by steric-exclusion h.p.l.c. The purified receptors showed Mr 67000 on SDS/polyacrylamide-gel electrophoresis under reducing conditions. Specific binding of radioligand to the purified beta-adrenergic receptors displayed stereoselectivity, and the agonist competition profiles demonstrated the presence of both beta 1- and beta 2-receptors. By using the subtype-selective ligands CGP-20712A (beta 1-selective) and ICI-118,551 (beta 2-selective), the purified Mr-67000 species was shown to be composed of equivalent amounts of beta 1- and beta 2-adrenergic receptors. Affinity chromatography on Sepharose-alprenolol and sequential elution with 1 microM-CGP-20712A followed by 100 microM(-)-alprenolol permitted beta 1-adrenergic receptors to be resolved from the mixture of beta 1-/beta 2-adrenergic receptors. The pharmacologically distinct human beta 1 and beta 2-adrenergic receptors are shown to be structurally very similar peptides.
| S-EPMC1148578 | biostudies-other
Project description:Shortly after birth, muscle cells of the mammalian heart lose their ability to divide. Thus, they are unable to effectively replace dying cells in the injured heart. The recent discovery that the transcriptional coactivator Yes-associated protein (Yap) is necessary and sufficient for cardiomyocyte proliferation has gained considerable attention. However, the upstream regulators and signaling pathways that control Yap activity in the heart are poorly understood.To investigate the role of ?-catenins in the heart using cardiac-specific ?E- and ?T-catenin double knockout mice.We used 2 cardiac-specific Cre transgenes to delete both ?E-catenin (Ctnna1) and ?T-catenin (Ctnna3) genes either in the perinatal or in the adult heart. Perinatal depletion of ?-catenins increased cardiomyocyte number in the postnatal heart. Increased nuclear Yap and the cell cycle regulator cyclin D1 accompanied cardiomyocyte proliferation in the ?-catenin double knockout hearts. Fetal genes were increased in the ?-catenin double knockout hearts indicating a less mature cardiac gene expression profile. Knockdown of ?-catenins in neonatal rat cardiomyocytes also resulted in increased proliferation, which could be blocked by knockdown of Yap. Finally, inactivation of ?-catenins in the adult heart using an inducible Cre led to increased nuclear Yap and cardiomyocyte proliferation and improved contractility after myocardial infarction.These studies demonstrate that ?-catenins are critical regulators of Yap, a transcriptional coactivator essential for cardiomyocyte proliferation. Furthermore, we provide proof of concept that inhibiting ?-catenins might be a useful strategy to promote myocardial regeneration after injury.
| S-EPMC4282606 | biostudies-literature
Project description:Stimulation of cardiac ?1A-adrenergic receptors (?1A-AR) has been proposed for treatment of heart failure, since it increases myocardial contractility. We investigated a different mechanism, induction of angiogenesis.Four to 6 weeks after permanent coronary artery occlusion, transgenic rats with cardiomyocyte-specific ?1A-adrenergic receptor overexpression had less remodeling than their nontransgenic littermates, with less fibrosis, hypertrophy and lung weight, and preserved left ventricular ejection fraction and wall stress (all P<0.05). Coronary blood flow, measured with microspheres, increased in the infarct zone in transgenic rats compared with nontransgenic littermates (1.4±0.2 versus 0.5±0.08 mL min(-1) g(-1); P<0.05), which is consistent with angiogenesis, as reflected by a 20% increase in capillary density in the zone adjacent to the infarct. The question arose, how does transgenic overexpression of a gene in cardiomyocytes induce angiogenesis? We identified a paracrine mechanism, whereby vascular endothelial growth factor-A mRNA and protein were increased in isolated transgenic cardiomyocytes and also by nontransgenic littermate cardiomyocytes treated with an ?1A-agonist, resulting in angiogenesis. Conditioned medium from cultured cardiomyocytes treated with an ?1A agonist enhanced human umbilical vein endothelial cell tubule formation, which was blocked by an anti-vascular endothelial growth factor-A antibody. Moreover, improved cardiac function, blood flow, and increased capillary density after chronic coronary artery occlusion in transgenic rats were blocked by either a mitogen ERK kinase (MEK) or a vascular endothelial growth factor-A inhibitor.Cardiomyocyte-specific overexpression of the ?1A-adrenergic receptors resulted in enhanced MEK-dependent cardiomyocyte vascular endothelial growth factor-A expression, which stimulates angiogenesis via a paracrine mechanism involving heterocellular cardiomyocyte/endothelial cell signaling, protecting against remodeling and heart failure after chronic coronary artery occlusion.
| S-EPMC4618777 | biostudies-literature
Project description:In order to determine the role of the adrenergic system in bupivacaine-induced cardiotoxicity, a series of experiments were performed. In an animal experiment, male Sprague-Dawley (SD) rats under chloral hydrate anesthesia received intravenous bupivacaine, followed by an intravenous injection of adrenalin or isoprenalin, and the electrocardiogram (ECG), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of rise of left ventricular pressure (+dP/dtmax) and the maximum rate of pressure decrease (-dP/dtmax) were continually monitored. In a cellular experiment, freshly isolated adult SD rat ventricular myocytes were perfused with bupivacaine at different concentrations in the presence or absence of isoprenalin, with or without esmolol. The percentage of the sarcomere shortening (bl% peak h), departure velocity (dep v) of sarcomere shortening and time to 50% of the peak speed of myocyte contraction (Tp50) was assessed by a video-based edge-detection system. In an additional experiment, Swiss mice pretreated with saline, isoprenalin, esmolol or dexmedetomidine received bupivacaine to determine the 50% lethal dose (LD50) of bupivacaine. Electron microscopy of myocardial mitochondria was performed to assess damage of these structures. To test mitochondrial reactive oxygen species (ROS) production, freshly isolated SD rat ventricular myocytes were incubated with bupivacaine in the presence of isoprenalin, with or without esmolol. First, our results showed that bupivacaine significantly reduced the LVSP and +dP/dtmax, as well as enhanced the LVEDP and -dP/dtmax (P < 0.05, vs. control, and vs. baseline). Adrenalin and isoprenalin induced a further reduction of LVSP and +dP/dtmax (P < 0.05, vs. before adrenalin or isoprenalin delivery, and vs. control). Second, bupivacaine induced a dose-dependent cardiomyocyte contractile depression. While 5.9 μmol/L or 8.9 μmol/L of bupivacaine resulted in no change, 30.0 μmol/L of bupivacaine prolonged the Tp50 and reduced the bl% peak h and dep v (P < 0.05, vs. control and vs. baseline). Isoprenalin aggravated the bupivacaine-induced cardiomyocyte contractile depression, significantly prolonging the Tp50 (P < 0.05, vs. bupivacaine alone) and reducing the dep v (P < 0.05, vs. bupivacaine alone). Third, esmolol and dexmedetomidine significantly enhanced, while isoprenalin significantly reduced, the LD50 of bupivacaine in mice. Fourth, bupivacaine led to significant mitochondrial swelling, and the extent of myocardial mitochondrial swelling in isoprenalin-pretreated mice was significantly higher than that compared with mice pretreated with saline, as reflected by the higher mitochondrial damage score (P < 0.01). Meanwhile, esmolol pretreatment significantly reduced the mitochondrial damage score (P < 0.01). Fifth, bupivacaine significantly increased the ROS in freshly isolated cardiomyocytes, and added isoprenalin induced a further enhancement of ROS production (P < 0.05, vs. bupivacaine alone). Added esmolol significantly decreased ROS production (P < 0.05, vs. bupivacaine + isoprenalin). Our results suggest that bupivacaine depressed cardiac automaticity, conductivity and contractility, but the predominant effect was contractile dysfunction which resulted from the disruption of mitochondrial energy metabolism. β-adrenergic activation aggravated the cellular metabolism disorder and therefore contractile dysfunction.
| S-EPMC6166930 | biostudies-literature
Project description:Critical functions of immune cells require them to rapidly change their shape and generate forces in response to cues from their surrounding environment. However, little is known about how soluble factors that may be present in the microenvironment modulate key aspects of cellular mechanobiology-such as immune cell deformability and force generation-to impact functions such as phagocytosis and migration. Here we show that signaling by soluble stress hormones through β-adrenoceptors (β-AR) reduces the deformability of macrophages; this is dependent on changes in the organization of the actin cytoskeleton and is associated with functional changes in phagocytosis and migration. Pharmacologic interventions reveal that the impact of β-AR signaling on macrophage deformability is dependent on actin-related proteins 2/3, indicating that stress hormone signaling through β-AR shifts actin organization to favor branched structures rather than linear unbranched actin filaments. These findings show that through remodeling of the actin cytoskeleton, β-AR-mediated stress hormone signaling modulates macrophage mechanotype to impact functions that play a critical role in immune response.-Kim, T.-H., Ly, C., Christodoulides, A., Nowell, C. J., Gunning, P. W., Sloan, E. K., Rowat, A. C. Stress hormone signaling through β-adrenergic receptors regulates macrophage mechanotype and function.
| S-EPMC6404566 | biostudies-literature
Project description:Chinese hamster ovary cell constructs expressing either the β 1-, β 2- or β 3-adrenergic receptor (AR) were used to determine whether a novel β-AR modulator, lubabegron fumarate (LUB; Experior, Elanco Animal Health) might exert greater potency for a specific β-AR subtype. EC50 values calculated based on cAMP accumulation in dose response curves indicate that LUB is highly selective for the β 3-AR subtype, with an EC50 of 6 × 10-9 M, with no detectible agonistic activity at the β 2-AR. We hypothesized that the accumulation of lipolytic markers would reflect the agonist activity at each of the β-receptor subtypes of the specific ligand; additionally, there would be differences in receptor subtype expression in subcutaneous (s.c.) and intrmuscular (i.m.) adipose tissues. Total RNA was extracted from adipose tissue samples and relative mRNA levels for β 1-, β2-, and β 3-AR were measured using real-time quantitative polymerase chain reaction. Fresh s.c. and i.m. adipose tissue explants were incubated with isoproterenol hydrochloride (ISO; β-AR pan-agonist), dobutamine hydrochloride (DOB; specific β 1-AA), salbutamol sulfate (SAL; specific β 2-AA), ractopamine hydrochloride (RAC), zilpaterol hydrochloride (ZIL), BRL-37344 (specific β 3-agonist), or LUB for 30 min following preincubation with theophylline (inhibitor of phosphodiesterase). Relative mRNA amounts for β 1-, β 2-, and β 3-AR were greater (P < 0.05) in s.c. than in i.m. adipose tissue. The most abundant β-AR mRNA in both adipose tissues was the β 2-AR (P < 0.05), with the β 1- and β 3-AR subtypes being minimally expressed in i.m. adipose tissue. ISO, RH, and ZH stimulated the release of glycerol and nonesterified fatty acid (NEFA) from s.c. adipose tissue, but these β-AR ligands did not alter concentrations of these lipolytic markers in i.m. adipose tissue. LUB did not affect glycerol or NEFA concentrations in s.c. or i.m. adipose tissue, but attenuated (P < 0.05) the accumulation of cAMP mediated by the β 1- and β 2-AR ligands DOB and SAL in s.c. adipose tissue. Collectively, these data indicate that bovine i.m. adipose tissue is less responsive than s.c. adipose tissue to β-adrenergic ligands, especially those that are agonists at the β 1- and β3-receptor subtypes. The minimal mRNA expression of the β 1- and β 3 subtypes in i.m. adipose tissue likely limits the response potential to agonists for these β-AR subtypes.
| S-EPMC8326056 | biostudies-literature