The association of T102C (rs6313) polymorphism in the 5-HT2A receptor gene with temporomandibular disorders and anxiety in a group of Turkish population.

OBJECTIVE: To investigate the relationship between T102C (rs6313) polymorphism in the 5-hydroxytryptamine receptor-2A (5HTR2A) gene and temporomandibular disorder (TMD) and anxiety. METHODS: This observational case-control study included 80 patients and 70 healthy controls. TMD was diagnosed using the criteria for TMD (DC/TMD). Anxiety was assessed with the Beck anxiety scale. A genotyping study of HTRR2A T102C (rs6313) gene polymorphism was performed from genomic DNA isolated from blood. RESULTS: The TMD group had higher anxiety scores than the control group (p < .05). The TMD group was similar to the control group regarding genotype and allele frequencies. However, the polymorphic CC genotype was more common in those with high anxiety (p < .05). CONCLUSION: There was no clear evidence of an association between TMD and the T102C polymorphism in HTR2A and TMD. However, anxiety is closely related to the T102C polymorphism in HTR2A.

The Association Between the 5-Hydroxytryptamine Receptor 2A Gene Variants rs6311 and rs6313 and Obstructive Sleep Apnea in the Iranian Kurdish Population.

Introduction: Sleep is one of the most significant parts of everyone's life. Most people sleep for about one-third of their lives. Sleep disorders negatively impact the quality of life. Obstructive sleep apnea (OSA) is a severe sleep disorder that significantly impacts the patient's life and their family members. This study aimed to investigate the relationship between rs6313 and rs6311 polymorphisms in the serotonin receptor type 2A gene and OSA in the Kurdish population. Materials and Methods: The study's population comprises 100 OSA sufferers and 100 healthy people. Polysomnography diagnostic tests were done on both the patient and control groups. The polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) was used to investigate the relationship between OSA and LEPR gene polymorphisms. Results: Statistical analysis showed a significant relationship between genotype frequencies of patient and control groups of rs6311 with OSA in dominant [odds ratio (OR) = 5.203, p < 0.001) and codominant models (OR = 9.7, p < 0.001). Also, there was a significant relationship between genotype frequencies of patient and control groups of rs6313 with OSA in dominant (OR = 10.565, p < 0.001) and codominant models (OR = 5.938, p < 0.001). Conclusions: Findings from the study demonstrated that the two polymorphisms rs6311 and rs6313 could be effective at causing OSA; however, there was no correlation between the severity of the disease and either of the two polymorphisms.

Neuronal and Molecular Mechanisms Underlying Chronic Pain and Depression Comorbidity in the Paraventricular Thalamus.

Patients with chronic pain often develop comorbid depressive symptoms, which makes the pain symptoms more complicated and refractory. However, the underlying mechanisms are poorly known. Here, in a repeated complete Freund's adjuvant (CFA) male mouse model, we reported a specific regulatory role of the paraventricular thalamic nucleus (PVT) glutamatergic neurons, particularly the anterior PVT (PVA) neurons, in mediating chronic pain and depression comorbidity (CDC). Our c-Fos protein staining observed increased PVA neuronal activity in CFA-CDC mice. In wild-type mice, chemogenetic activation of PVA glutamatergic neurons was sufficient to decrease the 50% paw withdrawal thresholds (50% PWTs), while depressive-like behaviors evaluated with immobile time in tail suspension test (TST) and forced swim test (FST) could only be achieved by repeated chemogenetic activation. Chemogenetic inhibition of PVA glutamatergic neurons reversed the decreased 50% PWTs in CFA mice without depressive-like symptoms and the increased TST and FST immobility in CFA-CDC mice. Surprisingly, in CFA-CDC mice, chemogenetically inhibiting PVA glutamatergic neurons failed to reverse the decrease of 50% PWTs, which could be restored by rapid-onset antidepressant S-ketamine. Further behavioral tests in chronic restraint stress mice and CFA pain mice indicated that PVA glutamatergic neuron inhibition and S-ketamine independently alleviate sensory and affective pain. Molecular profiling and pharmacological studies revealed the 5-hydroxytryptamine receptor 1D (Htr1d) in CFA pain-related PVT engram neurons as a potential target for treating CDC. These findings identified novel CDC neuronal and molecular mechanisms in the PVT and provided insight into the complicated pain neuropathology under a comorbid state with depression and related drug development.

Modified Sijunzi Granules Exhibit Hemostatic Effect by Activating Akt and Erk Signal Pathways via Regulating 5-HT and Its Receptors Levels.

OBJECTIVE: To investigate the hemostatic effect of modified Sijunzi Granules (MSG) in primary immune thrombocytopenia (ITP) zebrafish model and explore the potential mechanism. METHODS: AB strain wild type zebrafish were treated with simvastatin (6 µmol/L) for 24 h to establish the hemorrhage model (model control group). The zebrafish were treated with MSG at different doses (55.6, 167, and 500 µg/mL), respectively. The hemostatic effect was assessed by examining the intestinal bleeding and hemostatic rate. 5-Hydroxytryptamine (5-HT) content was determined using enzyme-linked immunosorbent assay (ELISA) assay. The expressions of 5-HT2aR, 5-HT2bR, and SERT genes were detected by quantitative real-time polymerase chain reaction(PCR). The protein expressions of protein kinase B (Akt), p-Akt, extracellular regulated protein kinases (Erk), and p-Erk were examined using Western blot analysis. RESULTS: The intestinal bleeding rate was 37%, 40%, and 80% in the 55.6, 167, and 500 µg/mL dose of MSG, respectively, in which 55.6 and 167 µg/mL MSG dose groups were associated with significantly decreased intestinal bleeding rate when compared with the model control group (70%, P<0.05). Significantly higher hemostatic rates were also observed in the 55.6 (54%) and 167 (52%) µg/mL MSG dose groups (P<0.05). MSG increased the 5-HT content and mRNA expression levels of 5-HT2aR, 5-HT2bR, and SERT (P<0.05). In addition, caspase3/7 activity was inhibited (P<0.05). Significant increase in p-Akt and p-Erk was also detected after treatment with MSG (P<0.05). CONCLUSIONS: MSG could reduce the incidence and severity of intestinal bleeding in zebrafish by activating MAPK/Erk and PI3K/Akt signal pathways through regulating the levels of 5-HT and its receptors, which may provide evidence for the treatment of ITP.

Dissecting the novel abilities of aripiprazole: The generation of anti-colorectal cancer effects by targeting Gαq via HTR2B.

Colorectal cancer (CRC) is a type of malignant tumor that seriously threatens human health and life, and its treatment has always been a difficulty and hotspot in research. Herein, this study for the first time reports that antipsychotic aripiprazole (Ari) against the proliferation of CRC cells both in vitro and in vivo, but with less damage in normal colon cells. Mechanistically, the results showed that 5-hydroxytryptamine 2B receptor (HTR2B) and its coupling protein G protein subunit alpha q (Gαq) were highly distributed in CRC cells. Ari had a strong affinity with HTR2B and inhibited HTR2B downstream signaling. Blockade of HTR2B signaling suppressed the growth of CRC cells, but HTR2B was not found to have independent anticancer activity. Interestingly, the binding of Gαq to HTR2B was decreased after Ari treatment. Knockdown of Gαq not only restricted CRC cell growth, but also directly affected the anti-CRC efficacy of Ari. Moreover, an interaction between Ari and Gαq was found in that the mutation at amino acid 190 of Gαq reduced the efficacy of Ari. Thus, these results confirm that Gαq coupled to HTR2B was a potential target of Ari in mediating CRC proliferation. Collectively, this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.

Neuroplastin 65 deficiency reduces amyloid plaque formation and cognitive deficits in an Alzheimer's disease mouse model.

Introduction: Alzheimer's disease (AD) is characterized by increasing cognitive dysfunction, progressive cerebral amyloid beta (Aß) deposition, and neurofibrillary tangle aggregation. However, the molecular mechanisms of AD pathologies have not been completely understood. As synaptic glycoprotein neuroplastin 65 (NP65) is related with synaptic plasticity and complex molecular events underlying learning and memory, we hypothesized that NP65 would be involved in cognitive dysfunction and Aß plaque formation of AD. For this purpose, we examined the role of NP65 in the transgenic amyloid precursor protein (APP)/presenilin 1 (PS1) mouse model of AD. Methods: Neuroplastin 65-knockout (NP65-/-) mice crossed with APP/PS1 mice to get the NP65-deficient APP/PS1 mice. In the present study, a separate cohort of NP65-deficient APP/PS1 mice were used. First, the cognitive behaviors of NP65-deficient APP/PS1 mice were assessed. Then, Aß plaque burden and Aß levels in NP65-deficient APP/PS1 mice were measured by immunostaining and western blot as well as ELISA. Thirdly, immunostaining and western blot were used to evaluate the glial response and neuroinflammation. Finally, protein levels of 5-hydroxytryptamin (serotonin) receptor 3A and synaptic proteins and neurons were measured. Results: We found that loss of NP65 alleviated the cognitive deficits of APP/PS1 mice. In addition, Aß plaque burden and Aß levels were significantly reduced in NP65-deficient APP/PS1 mice compared with control animals. NP65-loss in APP/PS1 mice resulted in a decrease in glial activation and the levels of pro- and anti-inflammatory cytokines (IL-1ß, TNF-α, and IL-4) as well as protective matrix YM-1 and Arg-1, but had no effect on microglial phenotype. Moreover, NP65 deficiency significantly reversed the increase in 5-hydroxytryptamine (serotonin) receptor 3A (Htr3A) expression levels in the hippocampus of APP/PS1 mice. Discussion: These findings identify a previously unrecognized role of NP65 in cognitive deficits and Aß formation of APP/PS1 mice, and suggest that NP65 may serve as a potential therapeutic target for AD.

Domesticated HERV-W env contributes to the activation of the small conductance Ca2+-activated K+ type 2 channels via decreased 5-HT4 receptor in recent-onset schizophrenia.

The human endogenous retroviruses type W family envelope (HERV-W env) gene is located on chromosome 7q21-22. Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase calcium influx. Additionally, the 5-HTergic system and particularly 5-hydroxytryptamine (5-HT) receptors play a prominent role in the pathogenesis and treatment of schizophrenia. 5-hydroxytryptamine receptor 4 (5-HT4R) agonist can block calcium channels. However, the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed. Here, we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia. Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca2+-activated K+ type 2 channels (SK2) expression levels. Further studies revealed that HERV-W env could interact with 5-HT4R. Additionally, luciferase assay showed that an essential region (-364 to -176 from the transcription start site) in the SK2 promoter was required for HERV-W env-induced SK2 expression. Importantly, 5-HT4R participated in the regulation of SK2 expression and promoter activity. Electrophysiological recordings suggested that HERV-W env could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R. In conclusion, HERV-W env could activate SK2 channels via decreased 5-HT4R, which might exhibit a novel mechanism for HERV-W env to influence neuronal activity in schizophrenia.

Effects of Banxia Shumi Decoction on 5-hydroxytryptamine receptor, 5-HT, and 5-HIAA of chronic insomnia rats with internal obstruction of phlegm-dampness / 国际中医中药杂志

Objective:To observe the effects of Banxia Shumi Decoction on 5-HT 1AR, 5-HT 2AR, 5-HT, and 5-HIAA of chronic insomnia (CI) rats with internal obstruction of phlegm-damp (IOPD) type, to investigate the mechanisms of Banxia Shumi Decoction on resolving and draining dampness, guiding yang into yin and tranquilizing mind. Methods:A total of 48 Wistar rats were divided into control group, model group, Banxia Shumi Decoction low-dosage group, medium-dosage group, high-dosage group, and diazepam group according to random number table method, with 8 rats in each group. Except the control group, the CI with IOPD rats model were prepared by the method of "high-fat diet + single-platform water environment" in other groups. The rats in the Banxia Shumi Decoction low-, medium-, high-dosage group were treated with Banxia Shumi Decoction by gavage at the dose of 4.69, 9.38 and 18.75 g/kg respectively, the rats in the diazepam group were given 0.52 mg/kg diazepam aqueous solution by gavage, and the rats in the control group and model group were given the equal volume normal saline, once a day for consecutive 2 weeks. The mRNA expressions of 5-HT 1AR, 5-HT 2AR in rat brain stem were detected by qPCR, the protein expressions of 5-HT 1AR, 5-HT 2AR in rat brain raphe nucleus were detected by Western blot, and the contents of 5-HT and 5-HIAA in rat brain stem were determined by HPLC-MS. Results:Compared with model group, the expression of 5-HT 1AR mRNA significantly increased in the Banxia Shumi Decoction low-, medium-, high-dosage group, and diazepam group ( P<0.01); the expression of 5-HT 2AR mRNA significantly decreased in the Banxia Shumi Decoction high-dosage group and diazepam group ( P<0.05), and the expression of 5-HT 1AR and 5-HT 2AR significantly increased in the Banxia Shumi Decoction high-dosage group and diazepam group ( P<0.05 or P<0.01); 5-HT content significantly increased in the Banxia Shumi Decoction medium-, high-dosage group and diazepam group ( P<0.05 or P<0.01); 5-HIAA content significantly increased in the Banxia Shumi Decoction low-, medium-, high-dosage group, and diazepam group ( P<0.05 or P<0.01). Conclusion:Banxia Shumi Decoction may intervene CI with IOPD type and perform the actions of resolving and draining dampness, guiding yang into yin and tranquilizing mind by regulating the expressions of 5-HT 1AR, 5-HT 2AR, 5-HT and 5-HIAA.

Dissecting the novel abilities of aripiprazole: The generation of anti-colorectal cancer effects by targeting Gαq via HTR2B

Colorectal cancer (CRC) is a type of malignant tumor that seriously threatens human health and life, and its treatment has always been a difficulty and hotspot in research. Herein, this study for the first time reports that antipsychotic aripiprazole (Ari) against the proliferation of CRC cells both in vitro and in vivo, but with less damage in normal colon cells. Mechanistically, the results showed that 5-hydroxytryptamine 2B receptor (HTR2B) and its coupling protein G protein subunit alpha q (Gαq) were highly distributed in CRC cells. Ari had a strong affinity with HTR2B and inhibited HTR2B downstream signaling. Blockade of HTR2B signaling suppressed the growth of CRC cells, but HTR2B was not found to have independent anticancer activity. Interestingly, the binding of Gαq to HTR2B was decreased after Ari treatment. Knockdown of Gαq not only restricted CRC cell growth, but also directly affected the anti-CRC efficacy of Ari. Moreover, an interaction between Ari and Gαq was found in that the mutation at amino acid 190 of Gαq reduced the efficacy of Ari. Thus, these results confirm that Gαq coupled to HTR2B was a potential target of Ari in mediating CRC proliferation. Collectively, this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.

Perceiving the Concealed and Unreported Pharmacophoric Features of the 5-Hydroxytryptamine Receptor Using Balanced QSAR Analysis.

The 5-hydroxytryptamine receptor 6 (5-HT6) has gained attention as a target for developing therapeutics for Alzheimer's disease, schizophrenia, cognitive dysfunctions, anxiety, and depression, to list a few. In the present analysis, a larger and diverse dataset of 1278 molecules covering a broad chemical and activity space was used to identify visual and concealed structural features associated with binding affinity for 5-HT6. For this, quantitative structure-activity relationships (QSAR) and molecular docking analyses were executed. This led to the development of a statistically robust QSAR model with a balance of excellent predictivity (R2tr = 0.78, R2ex = 0.77), the identification of unreported aspects of known features, and also novel mechanistic interpretations. Molecular docking and QSAR provided similar as well as complementary results. The present analysis indicates that the partial charges on ring carbons present within four bonds from a sulfur atom, the occurrence of sp3-hybridized carbon atoms bonded with donor atoms, and a conditional occurrence of lipophilic atoms/groups from nitrogen atoms, which are prominent but unreported pharmacophores that should be considered while optimizing a molecule for 5-HT6. Thus, the present analysis led to identification of some novel unreported structural features that govern the binding affinity of a molecule. The results could be beneficial in optimizing the molecules for 5-HT6.

Interplay between genetics and lifestyle on pain susceptibility in women with fibromyalgia: the al-Ándalus project.

OBJECTIVES: It is widely acknowledged that the experience of pain is promoted by both genetic susceptibility and environmental factors such as engaging in physical activity (PA), and that pain-related cognitions are also important. Thus, the purpose of the present study was to test the association of 64 polymorphisms (34 candidate genes) and the gene-gene, gene-PA and gene-sedentary behaviour interactions with pain and pain-related cognitions in women with FM. METHODS: Saliva samples from 274 women with FM [mean (s.d.) age 51.7 (7.7) years] were collected for extracting DNA. We measured PA and sedentary behaviour by accelerometers for a week, pain with algometry and questionnaires, and pain-related cognitions with questionnaires. To assess the robustness of the results, a meta-analysis was also performed. RESULTS: The rs6311 and rs6313 polymorphisms (5-hydroxytryptamine receptor 2A, HTR2A) were individually related to algometer scores. The interaction of rs4818 (catechol-O-methyltransferase, COMT) and rs1799971 (opioid receptor µ gene, OPRM1) was related to pain catastrophizing. Five gene-behaviour interactions were significant: the interactions of sedentary behaviour with rs1383914 (adrenoceptor alpha 1A, ADRA1A), rs6860 (charged multivesicular body protein 1A, CHMP1A), rs4680 (COMT), rs165599 (COMT) and rs12994338 (SCN9A) on bodily pain subscale of the Short Form 36. Furthermore, the meta-analysis showed an association between rs4680 (COMT) and severity of FM symptoms (codominant model, P-value 0.032). CONCLUSION: The HTR2A gene (individually), COMT and OPRM1 gene-gene interaction, and the interactions of sedentary behaviour with ADRA1A, CHMP1A, COMT and SCN9A genes were associated with pain-related outcomes. Collectively, findings from the present study indicate a modest contribution of genetics and gene-sedentary behaviour interaction to pain and pain catastrophizing in women with FM. Future research should examine whether reducing sedentary behaviour is particularly beneficial for reducing pain in women with genetic susceptibility to pain.

Identification and Pharmacological Characterization of Two Serotonin Type 7 Receptor Isoforms from Mythimna separata.

Serotonin (5-hydroxytryptamine, 5-HT) is an important neuroactive molecule, as neurotransmitters regulate various biological functions in vertebrates and invertebrates by binding and activating specific 5-HT receptors. The pharmacology and tissue distribution of 5-HT receptors have been investigated in several model insects, and these receptors are recognized as potential insecticide targets. However, little is known about the pharmacological characterization of the 5-HT receptors in important agricultural pests. In this study, we investigated the sequence, pharmacology, and tissue distribution of 5-HT7 receptors from oriental armyworm Mythimna separata (Walker) (Lepidoptera: Noctuidae), an important migratory and polyphagous pest species. We found that the 5-HT7 receptor gene encodes two molecularly distinct transcripts, Msep5-HT7L and Msep5-HT7S, by the mechanism of alternative splicing in M. separata. Msep5-HT7S differs from Msep5-HT7L based on the deletion of 95 amino acids within the third intracellular loop. Two Msep5-HT7 receptor isoforms were activated by 5-HT and synthetic agonists α-methylserotonin, 8-hydroxy-DPAT, and 5-methoxytryptamine, resulting in increased intracellular cAMP levels in a dose-dependent manner, although these agonists showed much poorer potency and efficacy than 5-HT. The maximum efficacy of 5-HT compared to the two 5-HT isoforms was equivalent, but 5-HT exhibited 2.63-fold higher potency against the Msep5-HT7S than the Msep5-HT7L receptor. These two isoforms were also blocked by the non-selective antagonist methiothepin and the selective antagonists WAY-100635, ketanserin, SB-258719, and SB-269970. Moreover, two distinct mRNA transcripts were expressed preferentially in the brain and chemosensory organs of M. separata adults, as determined by qPCR assay. This study is the first comprehensive characterization of two splicing isoforms of 5-HT7 receptors in M. separata, and the first to demonstrate that alternative splicing is also the mechanism for producing multiple 5-HT7 isoforms in insects. Pharmacological and gene expression profiles offer important information that could facilitate further exploration of their function in the central nervous system and peripheral chemosensory organs, and may even contribute to the development of new selective pesticides.

The Effects of Tryptamine Psychedelics in the Brain: A meta-Analysis of Functional and Review of Molecular Imaging Studies.

There is an increasing interest in the neural effects of psychoactive drugs, in particular tryptamine psychedelics, which has been incremented by the proposal that they have potential therapeutic benefits, based on their molecular mimicry of serotonin. It is widely believed that they act mainly through 5HT2A receptors but their effects on neural activation of distinct brain systems are not fully understood. We performed a quantitative meta-analysis of brain imaging studies to investigate the effects of substances within this class (e.g., LSD, Psilocybin, DMT, Ayahuasca) in the brain from a molecular and functional point of view. We investigated the question whether the changes in activation patterns and connectivity map into regions with larger 5HT1A/5HT2A receptor binding, as expected from indolaemine hallucinogens (in spite of the often reported emphasis only on 5HT2AR). We did indeed find that regions with changed connectivity and/or activation patterns match regions with high density of 5HT2A receptors, namely visual BA19, visual fusiform regions in BA37, dorsal anterior and posterior cingulate cortex, medial prefrontal cortex, and regions involved in theory of mind such as the surpramarginal gyrus, and temporal cortex (rich in 5HT1A receptors). However, we also found relevant patterns in other brain regions such as dorsolateral prefrontal cortex. Moreover, many of the above-mentioned regions also have a significant density of both 5HT1A/5HT2A receptors, and available PET studies on the effects of psychedelics on receptor occupancy are still quite scarce, precluding a metanalytic approach. Finally, we found a robust neuromodulatory effect in the right amygdala. In sum, the available evidence points towards strong neuromodulatory effects of tryptamine psychedelics in key brain regions involved in mental imagery, theory of mind and affective regulation, pointing to potential therapeutic applications of this class of substances.

The Association between 5-Hydroxytryptamine Receptor 1B rs13212041 Polymorphism and Trait Anxiety in Chinese Han College Subjects.

Trait anxiety is a vulnerable personality factor for anxiety and depression. High levels of trait anxiety confer an elevated risk for the development of anxiety and other psychiatric disorders. There is evidence that 5-hydroxytryptamine receptor 1B (5-HT1B) gene polymorphisms play an important role in emotional disorders. Genotyping for four single-nucleotide polymorphisms (SNP) (rs11568817, rs130058, rs6297, and rs13212041) was conducted for 388 high trait anxious (HTA) individuals and 463 low traitanxious (LTA) individuals in Chinese Han college subjects. The results showed that the frequencies of the C-allele and TC + CC genotype of rs13212041 in the LTA individuals were higher than that in the HTA individuals (p = 0.025 and p = 0.014, respectively). Both the C-allele and TC + CC genotype were associated with trait anxiety decreasing (OR = 0.771 and OR = 0.71, respectively). Furthermore, different gene model analysis also showed that the C allele was a protective factor for trait anxiety in Chinese Han college subjects. These findings suggest that 5-HT1B rs13212014 may play a role in trait anxiety among China Han college subjects. The rs13212014 polymorphism may be involved in decreasing the risk of trait anxiety. These results also provide a novel insight into the molecular mechanism underlying trait anxiety.

The roles of DNA methylation and hydroxymethylation at short interspersed nuclear elements in the hypothalamic arcuate nucleus during puberty.

Puberty is the gateway to adult reproductive competence, encompassing a suite of complex, integrative, and coordinated changes in neuroendocrine functions. However, the regulatory mechanisms of transcriptional reprogramming in the arcuate nucleus (ARC) during onset of puberty are still not fully understood. To understand the role of epigenetics in regulating gene expression, mouse hypothalamic ARCs were isolated at 4 and 8 weeks, and the transcriptome, DNA hydroxymethylation, DNA methylation, and chromatin accessibility were assessed via RNA sequencing (RNA-seq), reduced representation bisulfite sequencing (RRBS-seq), reduced representation hydroxymethylation profiling (RRHP)-seq, and assay for transposase-accessible chromatin (ATAC-seq), respectively. The overall DNA hydroxymethylation and DNA methylation changes in retroelements (REs) were associated with gene expression modeling for puberty in the ARC. We focused on analyzing DNA hydroxymethylation and DNA methylation at two short interspersed nuclear elements (SINEs) located on the promoter of the 5-hydroxytryptamine receptor 6 (Htr6) gene and the enhancer of the KISS-1 metastasis suppressor (Kiss1) gene and investigated their regulatory roles in gene expression. Our data uncovered a novel epigenetic mechanism by which SINEs regulate gene expression during puberty.

HTR7 promotes laryngeal cancer growth through PI3K/AKT pathway activation.

BACKGROUND: Laryngeal cancer is a common malignancy of the head and neck, it's important to find novel targets for its therapy. The 5-hydroxytryptamine receptor 7 (HTR7) belongs to the G protein-coupled receptors (GPCRs) family which are easily druggable in diseases; however, its role in laryngeal cancer remains unknown. METHODS: Colony formation assay, Soft agar growth assay, BrdU incorporation assay and MTT assay were used to analyze the effect of HTR7 on laryngeal cancer cell proliferation. Xenograft tumors in nude mice was used to analyze the effect of HTR7 on laryngeal cancer growth. Luciferase reporter assay was used to analyze the effect of HTR7 on phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) pathway activity. RESULTS: We found that HTR7 was significantly upregulated in laryngeal cancer tissues and cells, and patients with high HTR7 expression had shorter survival time than those with low HTR7 expression. Univariate and multivariate Cox regression models showed that HTR7 was an independent predictive factor for the prognosis of patients with laryngeal cancer. Cell proliferation assays and an animal model showed that HTR7 overexpression promoted laryngeal cancer proliferation and growth, while HTR7 knockdown inhibited laryngeal cancer proliferation and growth. Further analysis showed HTR7 activated the PI3K/AKT pathway, characterized by increased phosphorylation of AKT, luciferase reporter activity of forkhead box O (FOXO) factors, and target expression. Inhibition of the PI3K/AKT pathway in HTR7-overexpressing cells suppressed proliferation and growth, suggesting that HTR7 promotes laryngeal cancer proliferation and growth by activating the PI3K/AKT pathway. CONCLUSIONS: HTR7 is not only a target for laryngeal cancer therapy but also a prognostic factor for the prognosis of patients with laryngeal cancer.

Transactivation of G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs): Recent insights using luminescence and fluorescence technologies.

Alterations in signalling due to bidirectional transactivation of G protein-coupled receptor (GPCRs) and receptor tyrosine kinases (RTKs) are well established. Transactivation significantly diversifies signalling networks within a cell and has been implicated in promoting both advantageous and disadvantageous physiological and pathophysiological outcomes, making the GPCR/RTK interactions attractive new targets for drug discovery programmes. Transactivation has been observed for a plethora of receptor pairings in multiple cell types; however, the precise molecular mechanisms and signalling effectors involved can vary with receptor pairings and cell type. This short review will discuss the recent applications of proximity-based assays, such as resonance energy transfer and fluorescence-based imaging in investigating the dynamics of GPCR/RTK complex formation, subsequent effector protein recruitment and the cellular locations of complexes in living cells.

Involvement of 5-Hydroxytryptamine Receptor 2A in the Pathophysiology of Medication-Overuse Headache.

BACKGROUND: Recent studies indicated that analgesic overuse upregulated 5-hydroxytryptamine receptor 2A (5-HT2AR) and subsequently activated nitric oxide synthase (NOS) and thus induced latent sensitization, which provided a mechanistic basis for medication-overuse headache (MOH). Moreover, glycogen synthase kinase-3ß (GSK-3ß) was regulated by serotonin receptors and the phosphorylation of GSK-3ß affected NOS activity, indicating that GSK-3ß could be involved in the regulation of NOS activity by 5-HT2AR in MOH pathophysiology. Herein, we performed this study to investigate the role of 5-HT2AR in MOH pathophysiology and the role of GSK-3ß in the regulation of NOS activity by 5-HT2AR. MATERIALS AND METHODS: Wistar rats were daily administered with paracetamol (200 mg/kg) for 30 days to set animal models for pre-clinical MOH research. After the rat MOH models were successfully established, the expression of 5-HT2AR and NOS, GSK-3ß activity in trigeminal nucleus caudalis (TNC) were assayed. Then, 5-HT2AR antagonist ketanserin and agonist DOI were applied to investigate the effect of 5-HT2AR on NOS activity in TNC of MOH rats, and GSK-3ß antagonist LiCl and agonist perifosine were applied to explore the role of GSK-3ß in the activation of NOS by 5-HT2AR. RESULTS: We found that the expression of 5-HT2AR and NOS, GSK-3ß activity were enhanced in TNC of MOH rats. 5-HT2AR modulator regulated the activity of NOS and GSK-3ß in TNC of MOH rats, and drugs acting on GSK-3ß affected NOS activity. CONCLUSION: These data suggest that GSK-3ß may mediate the activation of NOS by 5-HT2AR and underline the role of 5-HT2AR in MOH pathophysiology.

Prophylactic antiemetic effects of dexamethasone versus 5-HT3 receptor antagonists in ear surgery: a systematic review and meta-analysis.

Background The optimal strategy for reducing the high incidence of postoperative nausea and vomiting (PONV) after otologic surgical procedures remains inconclusive. Aim of the review This study compared the prophylactic antiemetic effects of dexamethasone with 5-hydroxytryptamine 3 receptor antagonists (5-HT3-RAs) in ear surgery. Method PubMed, Embase, and Cochrane Library were searched up to October 31, 2020 for randomized controlled trials that used dexamethasone either singly or in combination with 5-HT3-RAs for PONV prophylaxis in adults undergoing ear surgery. Studies in languages other than English and those without a control group of 5-HT3-RAs were excluded. Random effects meta-analyses were performed, and risk of bias was assessed using the version 2 of the Cochrane risk-of-bias tool. Main outcome measures include incidences of early (< 6 h) and overall (0-48 h) PONV, the overall requirement for rescue antiemetics, and the occurrence of adverse events. Results Eight trials of 733 adults were included, and the overall risks of bias were generally low. Pooled risk ratios (RRs) of early and overall PONV of dexamethasone versus 5-HT3-RAs were 2.0 (95% CI 0.8-5.1, I2 = 82%), and 1.3 (95% CI 0.6-2.6, I2 = 86%). In studies comparing dexamethasone plus 5-HT3-RAs with 5-HT3-RAs alone, pooled RRs of early and overall PONV were 0.8 (95% CI 0.4-1.4, I2 = 30%), and 0.5 (95% CI 0.3-0.6, I2 = 0%), respectively. Pooled RRs of the overall need for rescue antiemetics comparing 5-HT3-RAs with dexamethasone alone and in combination with 5-HT3-RAs were 1.2 (95% CI 0.4-3.9, I2 = 73%) and 0.4 (95% CI 0.1-1.4, I2 = 61%), respectively. Common adverse events reported were headache and dizziness, and the incidences range from 0 to 10% without significant differences between the groups. Conclusion The prophylactic antiemetic effects of dexamethasone versus 5-HT3-RAs in ear surgery did not significantly differ in the early and overall postoperative phases. The combination of dexamethasone with 5-HT3-RAs showed superior overall PONV prophylactic effects to 5-HT3-RAs alone in ear surgery, but their differences in the need for rescue antiemetics remained non-significant.