Biology subjects

Nakayama, K.

Publications and source records attributed to Nakayama, K..

17 recordsLinked to original sources

bioRxiv2026

dCBP-mediated histone lactylation contributes to meiotic chromosome maintenance.

Histone lactylation is a recently identified histone post-translational modification (PTM) that links energy metabolism to chromatin regulation. Although histone lactylation has been implicated in transcriptional activation, its function in meiotic chromatin remains unclear. Previously, we identified enrichment of multiple histone lactylation marks within the meiotic karyosome, a highly condensed and transcriptionally repressive chromatin structure formed in Drosophila oocytes. Here, through an RNAi-based screen, we identified the CBP family protein dCBP as a regulator of histone lactylation in the karyosome. Germline-specific knockdown of dCBP preferentially reduced histone lactylation, including H4K8 lactylation, and caused premature disruption of the synaptonemal complex, abnormal egg chamber development with excess nurse cells, reduced egg production, and decreased embryonic viability. Corresponding histone acetylation marks were comparatively less affected than histone lactylation by dCBP knockdown. Together, our findings provide evidence that dCBP-mediated histone lactylation contributes to meiotic chromosome maintenance and suggest a potential link between energy metabolism and meiotic chromatin regulation.

developmental biology↗

bioRxiv2025

Emergence of cell polarity by reciprocal interactions between Wnt and core PCP components

Planar cell polarity (PCP) is established by asymmetric localization of core PCP components in each cell. Since some Wnt proteins can induce PCP in vertebrates, it has been proposed that Wnt concentration gradients provide spatial cues for polarization. Here, however, we present evidence that Wnt11 can regulate PCP in a gradient-independent manner. In the neural plate of Xenopus embryos, endogenous Wnt11 does not form an obvious gradient in the direction of PCP, but is polarized at cell boundaries together with core PCP components. Wnt11 polarization is dependent on core PCP components, while polarization of core PCP components can also be induced by Wnt11, indicating a mutual amplification loop between Wnt11 and core PCP components in PCP formation. Furthermore, Wnt11 and core PCP components compose an intercellular loop to coordinate the direction of polarity. Thus, we propose that local and reciprocal interactions between Wnt11 and core PCP components can generate PCP.

developmental biology↗

bioRxiv2025

Neuronal activity induces aggrecan expression to drive perineuronal net formation in cortical neurons

Synaptic plasticity, driven by activity-dependent changes in neuronal connectivity, underlies learning and memory. However, the mechanisms that sustain long-term synaptic stabilization are not well understood. Perineuronal nets (PNNs), which are lattice-like extracellular matrix structures that enwrap neurons, are thought to stabilize synapses. However, the mechanisms regulating their formation remain unclear. Here, we found that neuronal activity induces transcription of aggrecan, a core PNN component, which in turn promotes PNN assembly. In primary cultured mouse cortical neurons, pharmacological stimulation of neuronal activity robustly increased aggrecan expression, whereas activity blockade suppressed it. Among the PNN-related genes examined, aggrecan alone exhibited strong activity-dependent transcriptional regulation. Analysis of published in vivo datasets revealed selective upregulation of aggrecan in parvalbumin-positive interneurons following sensory stimulation. This regulation required calcium influx through voltage-gated calcium channels and was dependent on cAMP response element binding protein (CREB) signaling and chromatin remodeling. These findings reveal a novel molecular link between neuronal activity and PNN formation, providing insights into the mechanisms underlying the long-term stabilization of neural circuits.

neuroscience↗

bioRxiv2025

Metabolic cell death of labile iron deficiency as a vulnerability of head and neck squamous cancer cells evaded by BACH1

Head and neck squamous cell carcinoma (HNSCC) remains difficult to treat due to the lack of molecularly targeted drugs with high anti-tumor efficacy and safety. To investigate the involvement of the transcription factor BACH1, which is known to promote the metastasis of various cancers, in the malignant properties of HNSCC cells, we examined the effects of BACH1 depletion with short interfering RNAs in human HNSCC cell lines. We found that knockdown of BACH1 induced cell death due to depletion of intracellular labile iron which is not tightly bound to protein. Mitochodrial electron transfer chain activity was severely reduced but efficiently resuced with supplementation of iron in the medium. By combining chromatin immunoprecipitation-sequence and RNA-sequence analyses, we found that BACH1 represses ferritin genes in HNSCC cells. BACH1 knockdown was found to enhance the effect of tipifarnib, a selective inhibitor of farnesyltransferase required for HRAS activation, resulting in efficient inhibition of proliferation of HNSCC cell lines in vitro. These results indicate that BACH1 is essential for maintaining the amount of labile iron in HNSCC cells to evade metabolic cell death of iron deficiency and to proliferate. BACH1 can be a target for conferring Tipifarnib sensitivity to HNSCC cells.

cancer biology↗

bioRxiv2024

Lipid flippases ATP9A and ATP9B form a complex and contribute to the secretory pathway from the Golgi apparatus

Type IV P-type ATPases (P4-ATPases) serve as lipid flippases, translocating membrane lipids from the exoplasmic (or luminal) leaflet to the cytoplasmic leaflet of lipid bilayers. In mammals, these P4-ATPases are localized to distinct subcellular compartments. ATP8A1 and ATP9A, both members of the P4-ATPase family, are involved in endosome-mediated membrane trafficking, although the roles of P4-ATPases in the secretory pathway remain to be clarified. ATP9A and ATP9B are located in the trans-Golgi network, with ATP9A also present in endosomal compartments. This study unveiled the overlapping roles of ATP9A and ATP9B in transporting VSVG from the Golgi to the plasma membrane within the secretory pathway. Furthermore, we demonstrated that the flippase activities of ATP9A and ATP9B were crucial for transport process. Notably, we discovered the formation of homomeric and/or heteromeric complexes between ATP9A and ATP9B. The existence of the heteromeric complex notably contributed to the retention of ATP9A in the Golgi. Therefore, ATP9A and ATP9B play a role in the secretory pathway from the Golgi to the plasma membrane, forming either homomeric or heteromeric complexes.

cell biology↗

bioRxiv2024

ALS-associated RNA binding proteins converge on UNC13A transcription through regulation of REST

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons. Although multiple pathophysiological mechanisms have been identified, a unified molecular basis for ALS has remained elusive. The ALS-associated RNA binding protein (RBP) TDP-43 has previously been shown to stabilize UNC13A mRNA by preventing cryptic exon inclusion. We here show that three ALS-associated RBPs--MATR3, FUS, and hnRNPA1--regulate UNC13A expression by targeting the silencing transcription factor REST. These three RBPs bind to and downregulate REST mRNA and thereby promote UNC13A transcription. REST overexpression was detected not only in response to the loss of each of these three RBPs in cultured cells but also in motor neurons of individuals with familial or sporadic ALS. The functional convergence of four RBPs on the regulation of UNC13A, a gene essential for synaptic transmission, highlights a pivotal contribution of these proteins to maitainance of synaptic integrity. Our findings thus provide key insight into ALS pathogenesis and a basis for the development of new therapeutic agents.

neuroscience↗

bioRxiv2024

The braking force to Control the Abnormal Tibial Translation Affects the Spontaneous Healing Response for Complete Ruptured Anterior Cruciate Ligament in Mice Model

Purpose of this studyThe anterior cruciate ligament (ACL) has been believed to have a low spontaneous healing capacity; growing evidence has suggested that ACL could heal spontaneously. While the healed ACL has reduced mechanical properties and incomplete tissue maturation, the mechanisms underlying these problems remain unknown. We aimed to elucidate the effect of mechanical stresses during the early phase of spontaneous ACL healing. Materials and MethodsMale and female C57BL/6 mice were subjected to ACL rupture and randomly classified into three groups: Tight-CATT; tightly controlled anterior tibial translation (ATT), Loose-CATT; loosely controlled ATT and mild increasing mechanical stress compared to Tight-CATT, and ACL-Rupture (ACL-R) group; not controlled ATT. Mice were sacrificed and analyzed immediately after injury and at 4 and 8 weeks. We evaluated the effect of controlling the braking force of the ATT of each knee, the success rate of the ACL healing, collagen maturation, COL1A1 expression in the healed ACL, and the mechanical properties of the healed ACL. ResultsThe Tight-CATT group showed a higher success rate of ACL healing than the Loose-CATT group at 4 and 8 weeks. However, collagen maturation and the mechanical properties of healed ACL did not differ between the Tight-CATT and Loose-CATT groups. ConclusionOur results suggested that loose ATT braking immediately after injury is a negative factor for the healing of the completely ruptured ACL, and that it may be necessary to apply higher mechanical stress in the later stages to achieve greater healing.

physiology↗

bioRxiv2024

cGMP-dependent pathway and a GPCR kinase are required for photoresponse in the nematode Pristionchus pacificus

Light sensing is a critical function in most organisms and is mediated by photoreceptor proteins and phototransduction. Although most nematodes lack eyes, some species exhibit phototaxis. In the nematode Caenorhabditis elegans, the unique photoreceptor protein Cel-LITE-1, its downstream G proteins, and cyclic GMP (cGMP)-dependent pathways are required for phototransduction. However, the mechanism of light-sensing in other nematodes remains unknown. To address this question, we used the nematode Pristionchus pacificus, which was established as a satellite model organism for comparison with C. elegans. Similar to C. elegans, illumination with short-wavelength light induces avoidance behavior in P. pacificus. Opsin, cryptochrome/photolyase, and lite-1 were not detected in the P. pacificus genome using orthology and domain prediction-based analyses. To identify the genes related to phototransduction in P. pacificus, we conducted forward genetic screening for light-avoidance behavior and isolated four light-unresponsive mutants. Whole-genome sequencing and genetic mapping revealed that the cGMP-dependent pathway and Ppa-grk-2, which encodes a G protein-coupled receptor kinase (GRK) are required for light avoidance. Although the cGMP-dependent pathway is conserved in C. elegans phototransduction, GRK is not necessary for light avoidance in C. elegans. This suggests similarities and differences in light-sensing mechanisms between the two species. Using a reverse genetics approach, we showed that GABA and glutamate were involved in light avoidance. Through reporter analysis and suppression of synapse transmission, we identified candidate photosensory neurons. These findings advance our understanding of the diversity of phototransduction in nematodes even in the absence of eyes. Author summaryNematodes are a highly diverse group of animals found in a wide variety of habitats and sensory systems. In particular, light-induced behavior has been found to differ among species. The photoreceptor and its downstream pathways in Caenorhabditis elegans have been identified, revealing unique and distinct characteristics compared to those in other animals. However, the mechanisms of photoreception in other nematodes remain largely unknown. This study focused on the analysis of the photoreception mechanisms in Pristionchus pacificus, a species for which many genetic and molecular tools are available. Similar to C. elegans, P. pacificus also exhibits light avoidance behavior towards short-wavelength light; however, known animal photoreceptor genes could not be identified in the P. pacificus genome using bioinformatic approaches. Using forward and reverse genetic approaches, we found that certain genes and neurons are required for light avoidance, some of which are conserved in C. elegans photoreception. These results suggest that the light-sensing mechanisms of C. elegans and P. pacificus are similar, yet there are differences between the two species. These findings highlight the various light-sensing mechanisms in nematodes.

genetics↗

bioRxiv2024

ANKRD55 interacts with an IFT-B-like complex in microglia

IntroductionSNPs associated with genome-wide risk for multiple sclerosis (MS) modulate expression of ankyrin repeat domain protein 55 (ANKRD55). The function of ANKRD55 is not well understood. A role for ANKRD55 in ciliar transport in multiciliated cells has been reported. To gain deeper insight in how ANKRD55 may modulate neuro-inflammatory parameters, we identified the ANKRD55 interactomes from human neuroblastoma, astrocytic, microglial and monocytic cell lines. MethodsCell lines were transfected with synthetic ANKRD55 RNA in conjunction with nanoparticles. ANKRD55 interactomes were determined by affinity purification coupled to mass spectrometry (AP-MS) and analyzed bioinformatically. Results were validated and interpreted using confocal immunofluorescence microscopy, RNAseq transcriptomics, and a visible immunoprecipitation assay (VIP). ResultsShared among the interactomes were the 14-3-3 isoforms 14-3-3{eta} and 14-3-3{beta}{eta}. Unique to the microglial interactome were eight proteins belonging to the intraflagellar transport complex B (IFT-B). The IFT-B complex is known to mediate anterograde protein trafficking from the base to the tip of cilia. The dimer IFT46-IFT56 was identified as the minimum entity of IFT-B needed to support interaction with ANKRD55. To verify whether ANKRD55 is a ciliar transport protein, we induced ciliogenesis by serum starvation. Primary ARL13B+ cilia could be induced in the astrocytic and neuroblastoma, but not microglial, cell lines. By confocal microscopy, ANKRD55 was not detectable in these cilia but was enriched at the basal body. In the microglial cell line, ANKRD55 and IFT-B components were enriched at the centrosome. In two human primary myeloid cell models, monocyte-derived microglia (MoMG) and monocyte-derived dendritic cells (MoDC), we were able to recapitulate the co-localization of ANKRD55 and IFT81 at the centrosome. DiscussionOur work shows that an ANKRD55 - IFT-B-like complex is assembled in microglial cells. Together with the finding that ANKRD55 was not detected in primary cilia, the results suggest that ANKRD55 is associated with an IFT-B pathway that can operate independent of ciliogenesis.

immunology↗

bioRxiv2024

TANK binding kinase 1 promotes BACH1 degradation through both phosphorylation-dependent and -independent mechanisms without relying on heme and FBXO22

BTB and CNC homology 1 (BACH1) represses the expression of genes involved in the metabolism of iron, heme and reactive oxygen species. While BACH1 is rapidly degraded when it is bound to heme, it remains unclear how BACH1 degradation is regulated under other conditions. We found that FBXO22, a ubiquitin ligase previously reported to promote BACH1 degradation, polyubiquitinated BACH1 only in the presence of heme in a highly purified reconstitution assay. In parallel to this regulatory mechanism, TANK binding kinase 1 (TBK1), a protein kinase that activates innate immune response and regulates iron metabolism via ferritinophagy, was found to promote BACH1 degradation when overexpressed in 293T cells. While TBK1 phosphorylated BACH1 at multiple serine and threonine residues, BACH1 degradation was observed with not only the wild-type TBK1 but also catalytically impaired TBK1. The BACH1 degradation in response to catalytically impaired TBK1 was not dependent on FBXO22 but involved both autophagy-lysosome and ubiquitin-proteasome pathways judging from its suppression by using inhibitors of lysosome and proteasome. Chemical inhibition of TBK1 in hepatoma Hepa1 cells showed that TBK1 was not required for the heme-induced BACH1 degradation. Its inhibition in Namalwa B lymphoma cells increased endogenous BACH1 protein. These results suggest that TBK1 promotes BACH1 degradation in parallel to the FBXO22- and heme-dependent pathway, placing BACH1 as a downstream effector of TBK1 in iron metabolism or innate immune response.

biochemistry↗

bioRxiv2023

Novel phosphatidylinositol flippases contribute to phosphoinositide homeostasis in the plasma membrane

Phosphatidylinositol is a precursor of various phosphoinositides, which play crucial roles in intracellular signaling and membrane dynamics and have impact on diverse aspects of cell physiology. Phosphoinositide synthesis and turnover occur in the cytoplasmic leaflet of the organellar and plasma membranes. P4-ATPases (lipid flippases) are responsible for translocating membrane lipids from the exoplasmic (luminal) to the cytoplasmic leaflet, thereby regulating membrane asymmetry. However, the mechanism underlying phosphatidylinositol translocation across cellular membranes remains elusive. Here, we discovered that the phosphatidylcholine flippases ATP8B1, ATP8B2, and ATP10A can also translocate phosphatidylinositol at the plasma membrane. To explore the function of these phosphatidylinositol flippases, we used cells depleted of CDC50A, a protein necessary for P4-ATPase function. Upon activation of the Gq-coupled receptor, depletion of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] was accelerated in CDC50A knockout cells compared with control cells, suggesting a decrease in PtdIns4,5P2 levels within the plasma membrane of the knockout cells. These findings highlight the pivotal role of P4-ATPases in maintaining phosphoinositide homeostasis and suggest a mechanism for enrichment of phosphatidylinositol in the cytoplasmic leaflet of the plasma membrane.

cell biology↗

bioRxiv2023

Predictors of sensorimotor adaption: insights from over 100,000 reaches

Sensorimotor adaptation is essential for keeping our movements well-calibrated in response to changes in the body and environment. For over a century, we have studied sensorimotor adaptation in highly controlled laboratory settings that typically involve small sample sizes. While this approach has proven useful to characterize different learning processes, laboratory studies are typically very underpowered to generate data suited for exploring the myriad of factors that may modulate motor performance. Here, using a citizen science website (testmybrain.org), we collected over 2000 sessions on a visuomotor rotation task. This unique dataset has allowed us to replicate classic motor findings, reconcile controversial findings in the learning and memory literature, and discover novel constraints underlying dissociable implicit and explicit learning processes supporting sensorimotor adaptation. Taken together, this study suggests that large-scale motor learning studies hold enormous potential to advance sensorimotor neuroscience.

neuroscience↗

bioRxiv2022

Detection of adaptation to light environment in myopia-associated loci: Diversity of the myopia genetic background

The time spent outdoors and exposure to bright sunlight have been reported to play important roles in preventing myopia progression. Myopia prevalence is generally low in Europe, and we hypothesized that local adaptation of ancestors in insufficient sunlight regions might underlie this low prevalence in Europeans. To verify this conjecture and understand how ancestry adaptation influenced on the diversity of myopia genetic background, polygenic risk scores (PRS) was calculated and revealed that the genetic risk of myopia increased as latitude decreased in the 1000 genome projects (1KGP) EUR, and we further determined selection signatures near the rhodopsin (RHO) coding region in 1KGP Finnish. The derived allele frequencies of identified loci correlated with sunshine duration worldwide, and the allele age was estimated to be [~]20,000 years, coincidently after the divergence of Europeans and East Asians. TSPAN10 (rs9747347) is significantly associated with both myopia and pigmentation in Europeans, and we found selection favored the myopia risk allele in EUR. Haplotype comparison highlighted the divergence between EAS and EUR in RHO and pigmentation-associated loci, and the frequency diversity in Admixed American (AMR) of these loci was found to originate from recent admixture and local adaptation. We concluded that local adaptation played a role in myopia prevalence deviation, and selective pressure in the myopia-associated loci may originate from adaptation to sunlight environments rather than myopia itself. These findings reveal traces of evolution history of myopias genetic background, providing a new aspect of understanding the patterns and diversity of myopia prevalence. Author SummaryThe explanation for the distinct bias of myopia prevalence among ethnicities remains controversial, we took an evolutionary approach to understanding the history and diversity of the genetic background of myopia. We detected selection signatures of myopia-associated loci near the rhodopsin gene (RHO) in the 1000 Genome Project Europeans. Ambient light exposure is crucial for myopia; RHO is mainly expressed in rod cells and is extremely sensitive to light, indicating that local adaptation might contribute to myopia prevalence bias. Parallel geographical disposition of allele frequencies of myopia-associated loci in RHO and pigmentation-associated markers was observed, implying that selective pressure in myopia-associated loci may originate from adaptation events involved in sunlight exposure rather than myopia itself.

genetics↗

bioRxiv2022

Clinical mutations in WDR34 lead to diverse impacts on the assembly and function of dynein-2

The primary cilium is a sensory organelle, receiving signals from the external environment and relaying them into the cell. Mutations in proteins required for transport in the primary cilium result in ciliopathies, a group of genetic disorders that commonly lead to the malformation of organs such as the kidney, liver and eyes and skeletal dysplasias. Motor proteins dynein-2 and kinesin-2 mediate retrograde and anterograde transport respectively in the cilium. WDR34, a dynein-2 intermediate chain, is required for the maintenance of cilia function. Here, we investigated WDR34 mutations identified in Jeune syndrome, short-rib polydactyly syndrome or asphyxiating thoracic dysplasia patients. There is a poor correlation between genotype and phenotype in these cases making diagnosis and treatment highly complex. We set out to define the biological impacts on cilia formation and function of WDR34 mutations by stably expressing the mutant proteins in WDR34 knockout cells. WDR34 mutations led to different spectrums of phenotypes. Quantitative proteomics demonstrated changes in dynein-2 assembly, whereas initiation and extension of the axoneme, IFT-B protein localization, transition zone (TZ) integrity, and Hedgehog signalling were also affected. Summary statementDisease-associated mutations in WDR34 are found to have diverse impacts on ciliogenesis and cilia function following stable expression in a WDR34 knockout cell model.

cell biology↗

bioRxiv2022

Molecular mechanisms of Plasmodium development in male and female Anopheles mosquitoes

Vector competence influences the ability of Anopheles mosquitoes to transmit Plasmodium parasites. The aim of this study was to determine the competence of male and female Anopheles mosquitoes to support the development of Plasmodium parasites. Male and female A. stephensi (STE2 strain) were infected with in vitro-cultured P. berghei (ANKA strain) ookinetes. We found that the number of oocysts produced was higher in males than in females. RNA-seq analysis of male and female mosquitoes injected with P. berghei ookinetes showed that predominantly genes of unknown function changed in expression levels in response to ookinete infection; however, further studies are required to elucidate their functions. Moreover, male mosquitoes were injected with in vitro-cultured P. falciparum (3D7 strain) gametocytes or zygotes. The development of P. falciparum in males was detected using nested polymerase chain reaction. We found the DNA content was higher on day 15 than on day 0, indicating that P. falciparum developed in the mosquito hemocoel. This study revealed promising new mechanisms underlying the interactions between Plasmodium and mosquitoes. Author SummaryAnopheles mosquitoes transmit Plasmodium parasites that cause malaria disease. Vector competence is the ability of vectors to support pathogen development. The aim of this study was to determine the competence of male and female mosquitoes for Plasmodium parasites. Oocysts were formed in both male and female mosquitoes injected with ookinetes from in vitro-cultured Plasmodium berghei, which causes malaria in mice. The number of oocysts was higher in males, indicating that the competence in males was higher than that in females. RNA-seq analysis showed that the expression of genes of unknown function was highly variable in males and females. The genes defining the competence factors need further study, but the results indicate novel genes may be discovered. Furthermore, the development of Plasmodium falciparum, which causes the most severe malaria in humans, in male mosquitoes injected with in vitro-cultured gametocytes or zygotes was detected. As male mosquitoes do not suck blood, this method may allow us to experiment with Plasmodium more safely.

microbiology↗

bioRxiv2021

Large-scale mapping of positional changes of hypoxia-responsive genes upon activation

Chromosome structure and nuclear organization are important factors in the regulation of gene expression. Transcription of a gene is influenced by local and global chromosome features such as condensation status and histone modifications. The relationship between the position of a gene in the cell nucleus and its activity is less clear. Here, we used high-throughput imaging to perform a large-scale analysis of the spatial location of a set of nearly 100 hypoxia-inducible genes to determine whether their location within the nucleus is correlated with their activity state upon stimulation. Radial distance analysis demonstrated that the majority of HIF- and CREB-inducible hypoxia responsive genes are located in the intermediate region of the nucleus. Radial position of numerous responsive genes changed upon hypoxic treatment. Analysis of the relative distances amongst a subset of HIF target gene groups revealed that some gene pairs also altered their relative location to each other upon hypoxic treatment, suggesting higher order chromatin rearrangements. While these changes in location occurred in response to hypoxic activation of the target genes, they did not correlate with the extent of their activation. These results suggest that induction of the hypoxia-responsive gene expression program is accompanied by spatial alterations of the genome, but that radial and relative gene positions are not directly related to gene activity.

cell biology↗

bioRxiv2019

2-Cl-C.OXT-A Stimulates Contraction through the Suppression of Phosphodiesterase Activity in Human Induced Pluripotent Stem Cell-derived Cardiac Organoids

Background2-Cl-C.OXT-A (COA-Cl) is a novel synthesized adenosine analog that activates S1P1 receptor (S1P1R) and combines with adenosine A1 receptor (A1R) in G proteins and was shown to enhance angiogenesis and improve the brain function in rat stroke models. However, the role of COA-Cl in hearts remains unclear. COA-Cl, which has a similar structure to xanthine derivatives, has the potential to suppress phosphodiesterase (PDE), which is an important factor involved in the beating of heart muscle. Methods and resultsCardiac organoids with fibroblasts, human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs), and hiPSC-derived endothelial cells (hiPSC-ECs) were cultured until they started beating. The beating and contraction of organoids were observed before and after the application of COA-Cl. COA-Cl significantly increased the beating rate and fractional area change in organoids. To elucidate the mechanism underlying these effects of COA-Cl on cardiac myocytes, pure hiPSC-CM spheroids were evaluated in the presence/absence of Suramin (antagonist of A1R). The effects of COA-Cl, SEW2871 (direct stimulator of S1P1R), two positive inotropes (Isoproterenol [ISO] and Forskolin [FSK]), and negative inotrope (Propranolol [PRP]) on spheroids were assessed based on the beating rates and cAMP levels. COA-Cl stimulated the beating rates about 1.5-fold compared with ISO and FSK, while PRP suppressed the beating rate. However, no marked changes were observed with SEW2871. COA-Cl, ISO, and FSK increased the cAMP level. In contrast, the level of cAMP did not change with PRP or SEW2871 treatment. The results were the same in the presence of Suramin as absence. Furthermore, an enzyme analysis showed that COA-Cl suppressed the PDE activity by half. ConclusionsCOA-Cl, which has neovascularization effects, suppressed PDE and increased the contraction of cardiac organoids, independent of S1P1R and A1R. These findings suggest that COA-Cl may be useful as an inotropic agent for promoting angiogenesis in the future.

pharmacology and toxicology↗