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Stem Cells Translational Medicine Jun 2024As research on in vitro cardiotoxicity assessment and cardiac disease modeling becomes more important, the demand for human pluripotent stem cell-derived cardiomyocytes...
As research on in vitro cardiotoxicity assessment and cardiac disease modeling becomes more important, the demand for human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is increasing. However, it has been reported that differentiated hPSC-CMs are in a physiologically immature state compared to in vivo adult CMs. Since immaturity of hPSC-CMs can lead to poor drug response and loss of acquired heart disease modeling, various approaches have been attempted to promote maturation of CMs. Here, we confirm that peroxisome proliferator-activated receptor alpha (PPARα), one of the representative mechanisms of CM metabolism and cardioprotective effect also affects maturation of CMs. To upregulate PPARα expression, we treated hPSC-CMs with fenofibrate (Feno), a PPARα agonist used in clinical hyperlipidemia treatment, and demonstrated that the structure, mitochondria-mediated metabolism, and electrophysiology-based functions of hPSC-CMs were all mature. Furthermore, as a result of multi electrode array (MEA)-based cardiotoxicity evaluation between control and Feno groups according to treatment with arrhythmia-inducing drugs, drug response was similar in a dose-dependent manner. However, main parameters such as field potential duration, beat period, and spike amplitude were different between the 2 groups. Overall, these results emphasize that applying matured hPSC-CMs to the field of preclinical cardiotoxicity evaluation, which has become an essential procedure for new drug development, is necessary.
PubMed: 38946019
DOI: 10.1093/stcltm/szae029 -
Nihon Yakurigaku Zasshi. Folia... 2024Growing evidence has indicated that delta opioid receptor (DOP) agonists are potential psychotropic drugs such as for depression, anxiety, and PTSD. In rodent studies,...
Growing evidence has indicated that delta opioid receptor (DOP) agonists are potential psychotropic drugs such as for depression, anxiety, and PTSD. In rodent studies, we have also demonstrated that DOP agonists exhibit potent anxiolytic-like effects via the inhibition of the excitatory neuronal activity which projects to the amygdala from the prelimbic prefrontal cortex and facilitate extinction learning of contextual fear memory through PI3K-Akt signaling pathway in the infralimbic prefrontal cortex and MEK-ERK signaling pathway in the amygdala. In this article, we introduce the functional mechanisms underlying antidepressant-like effects and anti-stress effects of DOP agonists. Then, we employed a valid animal model of depression, chronic vicarious social defeat stress (cVSDS) mice, and investigated that the influence of DOP activation on pathopsychological factors in depression such as the adult hippocampal neurogenesis, hypothalamic-pituitary-adrenal (HPA) axis, and neuroinflammation. First, repeated administrations after the stress period to cVSDS mice with a selective DOP agonist, KNT-127, improved social interaction behaviors and reduced hyperactivation of the HPA axis without affecting hippocampal neurogenesis. Meanwhile, repeated KNT-127 administrations during the cVSDS period prevented the exacerbation of social interaction behaviors, dysregulation of the HPA axis, and excessive new-born neuronal cell death in the hippocampal dentate gyrus. Moreover, in both administration paradigms, KNT-127 suppressed microglial overactivation in the dentate gyrus of cVSDS mice. These results indicate that the underlying mechanism of DOP-induced antidepressant-like effects differ from those of conventional monoaminergic antidepressants. Furthermore, we propose that DOP agonists might have prophylactic effects as well as therapeutic effects on pathophysiological changes in depression.
Topics: Animals; Receptors, Opioid, delta; Psychotropic Drugs; Humans; Mice; Stress, Psychological
PubMed: 38945905
DOI: 10.1254/fpj.24011 -
Experimental Animals Jun 2024The complement active product, C3a, and the receptor C3aR comprise an axis that exerts various biological functions, such as protection against infection. C3a is highly...
The complement active product, C3a, and the receptor C3aR comprise an axis that exerts various biological functions, such as protection against infection. C3a is highly expressed in the inflamed skin and blood from patients with psoriasiform dermatitis. However, the role of the C3a/C3aR axis in psoriasiform dermatitis remains unclear because conflicting results using C3 mice have been published. In this study, to elucidate the contribution of commensal microbiota in C3 and wild-type (WT) mice were subjected to imiquimod-induced psoriasiform dermatitis under different housing conditions. C3 mice showed increased epidermal thickness and keratinocyte proliferation markers in the inflamed ear compared to WT mice upon treatment with IMQ. These inflamed phenotypes were observed in both cohoused and separately housed conditions, and antibiotic treatment did not abolish the aggravation of IMQ-induced psoriasiform dermatitis in C3 mice. These results suggested that the difference of commensal microbiota is not important for the C3-involved psoriasiform dermatitis. Keratinocyte hyperproliferation is a major feature of the inflamed skin in patients with psoriasiform dermatitis. In vitro experiments showed that C3a and C3aR agonists inhibited keratinocyte proliferation, which was abolished by introduction of a C3aR antagonist. Collectively, these results suggest that the C3a/C3aR axis plays a critical role in psoriasiform dermatitis development by inhibiting keratinocyte proliferation, regardless of the regulation of the commensal microbiota.
PubMed: 38945882
DOI: 10.1538/expanim.24-0043 -
Journal of Sleep Research Jun 2024Benzodiazepine receptor agonists are often used for insomnia in older adults contrary to current evidence. The harms outweigh the benefits, which are limited. Cognitive...
Sleep should not be this difficult: An interpretive descriptive study of older adults' perspectives on behaviour change elements in Sleepwell and experiences with benzodiazepine discontinuation.
Benzodiazepine receptor agonists are often used for insomnia in older adults contrary to current evidence. The harms outweigh the benefits, which are limited. Cognitive behavioural therapy for insomnia is the first-line recommended treatment. Sleepwell was created as a repository of evidence-based resources to promote cognitive behavioural therapy for insomnia and limit benzodiazepine receptor agonist use. This qualitative study uses an interpretive description design and reflexive thematic analysis to explore older adults' perspectives on behavioural change techniques used in Sleepwell resources. It also explores challenges and opportunities towards benzodiazepine receptor agonist discontinuation and cognitive behavioural therapy for insomnia use. Participants were recruited from the Sleepwell arm of a randomized controlled trial. Data were collected from 15 older adults using semi-structured interviews. Two main themes were developed: (1) sleep should not be this difficult; and (2) whether you know it, or learn it, drugs are bad. Two sub-themes were created within the first theme: (1) justification of benzodiazepine receptor agonist use to achieve sleep goals; (2) efforts of committing to cognitive behavioural therapy for insomnia. Several behavioural change techniques (e.g. information about consequences, anticipated regret, salience of consequences) were enablers of benzodiazepine receptor agonist-related behaviour change. For committing to cognitive behavioural therapy for insomnia, several behavioural change techniques (e.g. self-monitoring of behaviour, distraction, stimulus substitution) were beneficial, but social support, which was perceived as useful, was absent. Older adults experienced tension with benzodiazepine receptor agonist use and deprescribing, despite knowing or learning the potential consequences of benzodiazepine receptor agonists. Cognitive behavioural therapy for insomnia implementation was challenging. Embedded behavioural change techniques in the Sleepwell booklets were identified as helpful, but more (e.g. social support) are needed to optimize cognitive behavioural therapy for insomnia use.
PubMed: 38945830
DOI: 10.1111/jsr.14282 -
Chinese Medical Journal Jun 2024Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress...
Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress HBV replication and improve the prognosis. However, the persistence of covalently closed circular DNA (cccDNA), the integration of HBV-DNA into the host genome, and compromised immune responses impede the successful treatment of hepatitis B. While achieving a functional cure of HBV remains elusive with the current treatment methods, this is the goal of new therapeutic approaches. Therefore, developing novel antiviral drugs is necessary for achieving a functional or complete cure for chronic hepatitis B. In recent years, substantial progress has been made in drug discovery and development for HBV infection. Direct-acting antiviral agents such as entry inhibitors, capsid assembly modulators, subviral particle release inhibitors, cccDNA silencers, and RNA interference molecules have entered clinical trials. In addition, several immunomodulatory agents, including toll-like receptor agonists, therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also making their way toward clinical use. In this review, we summarize the recent progress and limitations of chronic hepatitis B treatment and discuss perspectives on approaches to achieving functional cure. Although it will take some time for these new antiviral drugs to be widely used in clinical practice, combination therapy may become a preferable treatment option in the future.
PubMed: 38945693
DOI: 10.1097/CM9.0000000000003178 -
Chinese Medical Journal Jun 2024Hepatic inflammatory cell accumulation and the subsequent systematic inflammation drive acute-on-chronic liver failure (ACLF) development. Previous studies showed that...
BACKGROUND
Hepatic inflammatory cell accumulation and the subsequent systematic inflammation drive acute-on-chronic liver failure (ACLF) development. Previous studies showed that the vagus nerve exerts anti-inflammatory activity in many inflammatory diseases. Here, we aimed to identify the key molecule mediating the inflammatory process in ACLF and reveal the neuroimmune communication arising from the vagus nerve and immunological disorders of ACLF.
METHODS
Proteomic analysis was performed and validated in ACLF model mice or patients, and intervention animal experiments were conducted using neutralizing antibodies. PNU-282987 (acetylcholine receptor agonist) and vagotomy were applied for perturbing vagus nerve activity. Single-cell RNA sequencing (scRNA-seq), flow cytometry, immunohistochemical and immunofluorescence staining, and CRISPR/Cas9 technology were used for in vivo or in vitro mechanistic studies.
RESULTS
The unbiased proteomics identified C-X-C motif chemokine ligand 9 (CXCL9) as the greatest differential protein in the livers of mice with ACLF and its relation to the systematic inflammation and mortality were confirmed in patients with ACLF. Interventions on CXCL9 and its receptor C-X-C chemokine receptor 3 (CXCR3) improved liver injury and decreased mortality of ACLF mice, which were related to the suppressing of hepatic immune cells' accumulation and activation. Vagus nerve stimulation attenuated while vagotomy aggravated the expression of CXCL9 and the severity of ACLF. Blocking CXCL9 and CXCR3 ameliorated liver inflammation and increased ACLF-associated mortality in ACLF mice with vagotomy. scRNA-seq revealed that hepatic macrophages served as the major source of CXCL9 in ACLF and were validated by immunofluorescence staining and flow cytometry analysis. Notably, the expression of CXCL9 in macrophages was modulated by vagus nerve-mediated cholinergic signaling.
CONCLUSIONS
Our novel findings highlighted that the neuroimmune communication of the vagus nerve-macrophage-CXCL9 axis contributed to ACLF development. These results provided evidence for neuromodulation as a promising approach for preventing and treating ACLF.
PubMed: 38945689
DOI: 10.1097/CM9.0000000000003104 -
Food Research International (Ottawa,... Aug 2024Yeast extracts (YEs) are used in foods because of their flavour properties and ability to reduce bitterness. The adenosine 5'-monophosphate (AMP) found in YEs is known...
Yeast extracts (YEs) are used in foods because of their flavour properties and ability to reduce bitterness. The adenosine 5'-monophosphate (AMP) found in YEs is known to decrease the bitterness of some compounds. This study aimed to investigate the ability of YEs to inhibit bitter taste receptors (TAS2Rs) using in vitro cell-based assays. A screen of TAS2Rs activated by AMP and YEs revealed that AMP and the AMP-rich YE activated more TAS2Rs. The inhibitory effect of the AMP-rich YE on seven TAS2Rs activated by bitter agonists was studied. YE reduced TAS2R activation, increased the EC value and decreased the maximum amplitude, demonstrating competitive and non-competitive inhibitions. Amongst the nineteen TAS2Rs tested, seven showed 40 % or greater inhibition after treatment of AMP-rich YE. Our data provide a better understanding of the TAS2R inhibition mechanism of AMP-rich YEs and promote their use as a strategy to reduce bitterness in foods and medicines.
Topics: Receptors, G-Protein-Coupled; Humans; Taste; Adenosine Monophosphate; HEK293 Cells; Yeasts
PubMed: 38945612
DOI: 10.1016/j.foodres.2024.114596 -
The Journal of Biological Chemistry Jun 2024Opioid use disorders (OUD) and overdoses are ever-evolving public health threats that continue to grow in incidence and prevalence in the United States and abroad....
Opioid use disorders (OUD) and overdoses are ever-evolving public health threats that continue to grow in incidence and prevalence in the United States and abroad. Current treatments consist of opioid receptor agonists and antagonists, which are safe and effective but still suffer from some limitations. Murine and humanized monoclonal antibodies (mAb) have emerged as an alternative and complementary strategy to reverse and prevent opioid-induced respiratory depression. To explore antibody applications beyond traditional heavy-light chain mAbs, we identified and biophysically characterized a novel single-domain antibody specific for fentanyl from a camelid variable-heavy-heavy (VHH) domain phage display library. Structural data suggested that VHH binding to fentanyl was facilitated by a unique domain-swapped dimerization mechanism, which accompanied a rearrangement of complementarity-determining region (CDR) loops leading to the formation of a fentanyl-binding pocket. Structure-guided mutagenesis further identified an amino acid substitution that improved the affinity and relaxed the requirement for dimerization of the VHH in fentanyl binding. Our studies demonstrate VHH engagement of an opioid and inform on how to further engineer a VHH for enhanced stability and efficacy, laying the groundwork for exploring the in vivo applications of VHH-based biologics against OUD and overdose.
PubMed: 38945452
DOI: 10.1016/j.jbc.2024.107502 -
Comparative Biochemistry and... Jun 2024Environmental endocrine disrupting chemical 4-tert-butylphenol (4-tBP), a widely-utilized surfactant in various industries, poses potential risks to aquatic organisms....
Environmental endocrine disrupting chemical 4-tert-butylphenol induced calcium overload and subsequent autophagy impairment via miRNA-363/CACNA1D Axis in epithelioma papulosum cyprini cells.
Environmental endocrine disrupting chemical 4-tert-butylphenol (4-tBP), a widely-utilized surfactant in various industries, poses potential risks to aquatic organisms. Our previous sequencing results suggested that 4-tBP-induced common carp liver injury might be associated with Ca signaling and autophagy. However, the intricate involvement of these pathways in 4-tBP-induced cytotoxic mechanisms remained unexplored. To bridge these knowledge gaps, this study focused on epithelioma papulosum cyprini (EPC) cells, a significant cell type in fish biology. Initial observations showed that 4-tBP induced a dose-dependent perturbation in Ca levels. Further investigations, with siRNA and L-type Ca channel agonist (BAYK8644), identified L-type calcium channel gene CACNA1D as a critical regulator of 4-tBP-induced Ca overload. Predictive analysis using miRanda platform suggested a potential interaction between miR-363 and CACNA1D, which was subsequently verified through dual-luciferase reporter gene assays. We then established miR-363 mimic/inhibitor models, along with miR-363 and CACNA1D co-suppression models in EPC cells. Through TEM observation, immunofluorescence assay, Ca staining, and qRT-PCR analysis, we evaluated the role of miR-363/CACNA1D axis in modulating the effects of 4-tBP on Ca signaling and autophagy. Results showed that miR-363 inhibitor exacerbated 4-tBP-induced increase in CALM2, CAMKII, Calpain2, and p62 expression and also led to decrease in ATG5, ATG7, and LC3b expression. In contrast, miR-363 mimic notably alleviated these changes. Notably, siRNA CACNA1D effectively modulating miR-363 inhibitor's effect. Our study revealed that 4-tBP induced Ca overload and subsequent autophagy impairment via miR-363/CACNA1D axis. These findings illuminated a profound understanding of molecular mechanisms underlying 4-tBP-induced cytotoxicity and spotlighted a potential therapeutic target.
PubMed: 38945384
DOI: 10.1016/j.cbpc.2024.109968 -
European Journal of Pharmacology Jun 2024Bitter taste receptors (TAS2Rs) and their downstream signaling pathways are expressed not only in the oral tissues but also in extraoral tissues. Emerging data has...
AIMS
Bitter taste receptors (TAS2Rs) and their downstream signaling pathways are expressed not only in the oral tissues but also in extraoral tissues. Emerging data has demonstrated the beneficial effect of ghrelin in neurodegenerative diseases. Gaining more insight into the interaction between TAS2Rs and gut hormones may expand their therapeutic applications. Herein, we aimed to assess the possible effect of TAS2R activation by denatonium benzoate (DB) in modulating functional and neurobiochemical alterations in a model of Parkinson's disease (PD).
MAIN METHODS
PD model was induced by daily injection of rotenone (2 mg/kg). Rats received DB (5 mg/kg), atenolol (10 mg/kg), or both concomitantly with rotenone, daily for 28 days. Evaluation of the motor abnormalities and histological examination of brain tissues were conducted. In addition, striatal dopamine contents, immunohistochemical expression of tyrosine hydroxylase, plasma ghrelin level, and biochemical analysis of markers of inflammation and oxidative stress were assessed.
KEY FINDINGS
Treatment with DB increased serum levels of ghrelin and striatal dopamine contents with consequent amelioration of oxidative stress and attenuation of inflammatory cytokines. Moreover, DB treatment significantly ameliorated motor disturbance and histological abnormalities compared to untreated rats. Atenolol inhibited ghrelin release and abolished the positive effect of DB suggesting the involvement of ghrelin on such effects.
SIGNIFICANCE
The current study suggests that TAS2Rs agonists are promising candidates for ameliorating rotenone-induced PD pathology in rats, an action that could be linked to the enhancement of ghrelin release with consequent antioxidant and anti-inflammatory activities.
PubMed: 38945288
DOI: 10.1016/j.ejphar.2024.176802