The Human Serotonin Type 3 Receptor Gene (HTR3A-E) Allelic Variant Database

A web-based dynamic predictive model for postoperative nausea and vomiting in patient receiving gynecological laparoscopic surgery

OBJECTIVE

The aim of this study was to develop a web-based dynamic prediction model for postoperative nausea and vomiting (PONV) in patients undergoing gynecologic laparoscopic surgery.

METHODS

The patients (N = 647) undergoing gynecologic laparoscopic surgery were included in this observational study. The candidate risk-factors related to PONV were included through literature search. Lasso regression was utilized to screen candidate risk-factors, and the variables with statistical significance were selected in multivariable logistic model building. The web-based dynamic Nomogram was used for model exhibition. Accuracy and validity of the experimental model (EM) were evaluated by generating receiver operating characteristic (ROC) curves and calibration curves. Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model. Decision curve analysis (DCA) was used to evaluate the clinical practicability of the risk prediction model.

RESULTS

Ultimately, a total of five predictors including patient-controlled analgesia (odds ratio [OR], 4.78; 95% confidence interval [CI], 1.98-12.44), motion sickness (OR, 4.80; 95% CI, 2.71-8.65), variation of blood pressure (OR, 4.30; 95% CI, 2.41-7.91), pregnancy vomiting history (OR, 2.21; 95% CI, 1.44-3.43), and pain response (OR, 1.64; 95% CI, 1.48-1.83) were selected in model building. Assessment of the model indicates the discriminating power of EM was adequate (ROC-areas under the curve, 93.0%; 95% CI, 90.7%-95.3%). EM showed better accuracy and goodness of fit based on the results of the calibration curve. The DCA curve of EM showed favorable clinical benefits.

CONCLUSIONS

This dynamic prediction model can determine the PONV risk in patients undergoing gynecologic laparoscopic surgery.

Pharmacogenetics in IBS: update and impact of GWAS studies in drug targets and metabolism

INTRODUCTION

Medications are frequently prescribed for patients with irritable bowel syndrome (IBS) or disorders of gut brain interaction. The level of drug metabolism and modifications in drug targets determine medication efficacy to modify motor or sensory function as well as patient response outcomes.

AREAS COVERED

The literature search included PubMed searches with the terms: pharmacokinetics, pharmacogenomics, epigenetics, clinical trials, irritable bowel syndrome, disorders of gut brain interaction, and genome-wide association studies. The main topics covered in relation to irritable bowel syndrome were precision medicine, pharmacogenomics related to drug metabolism, pharmacogenomics related to mechanistic targets, and epigenetics.

EXPERT OPINION

Pharmacogenomics impacting drug metabolism [CYP 2D6 (cytochrome P450 2D6) or 2C19 (cytochrome P450 2C19)] is the most practical approach to precision medicine in the treatment of IBS. Although there are proof of concept studies that have documented the importance of genetic modification of transmitters or receptors in altering responses to medications in IBS, these principles have rarely been applied in patient response outcomes. Genome-wide association (GWAS) studies have now documented the association of symptoms with genetic variation but not the evaluation of treatment responses. Considerably more research, particularly focused on patient response outcomes and epigenetics, is essential to impact this field in clinical medicine.

Serotonergic regulation of appetite and sodium appetite

Serotonin is a neurotransmitter that is synthesized and released from the brainstem raphe nuclei to affect many brain functions. It is well known that the activity of raphe serotonergic neurons is changed in response to the changes in feeding status to regulate appetite via the serotonin receptors. Likewise, changes in volume status are known to alter the activity of raphe serotonergic neurons and drugs targeting serotonin receptors were shown to affect sodium appetite. Therefore, the central serotonin system appears to regulate ingestion of both food and salt, although neural mechanisms that induce appetite in response to hunger and sodium appetite in response to volume depletion are largely distinct from each other. In this review, we discuss our current knowledge regarding the regulation of ingestion - appetite and sodium appetite - by the central serotonin system.

Serotonin system in the human placenta - the knowns and unknowns

The biogenic monoamine serotonin (5-hydroxytryptamine, 5-HT) is a chemical messenger widely distributed in the brain and various other organs. Its homeostasis is maintained by the coordinated activity of a variety of proteins, including enzymes of serotonin metabolism, transmembrane transporters of serotonin, and serotonin receptors. The serotonin system has been identified also in the placenta in rodent models as a key component of placental physiology. However, serotonin pathways in the human placenta are far from well understood. Their alterations may have long-lasting consequences for the fetus that can manifest later in life. In this review, we summarize information on the location of the components of the serotonin system in the human placenta, their regulation, function, and alterations in pathological pregnancies. We highlight current controversies and discuss important topics for future research.

Serotonin type 3 receptor subunit gene polymorphisms associated with psychosomatic symptoms in irritable bowel syndrome: A multicenter retrospective study

BACKGROUND

Single-nucleotide polymorphisms (SNPs) of the serotonin type 3 receptor subunit (HTR3) genes have been associated with psychosomatic symptoms, but it is not clear whether these associations exist in irritable bowel syndrome (IBS).

AIM

To assess the association of HTR3 polymorphisms with depressive, anxiety, and somatization symptoms in individuals with IBS.

METHODS

In this retrospective study, 623 participants with IBS were recruited from five specialty centers in Germany, Sweden, the United States, the United Kingdom, and Ireland. Depressive, anxiety, and somatization symptoms and sociodemographic characteristics were collected. Four functional SNPs - HTR3A c.-42C>T, HTR3B c.386A>C, HTR3C c.489C>A, and HTR3E c.*76G>A - were genotyped and analyzed using the dominant and recessive models. We also performed separate analyses for sex and IBS subtypes. SNP scores were calculated as the number of minor alleles of the SNPs above. The impact of HTR3C c.489C>A was tested by radioligand-binding and calcium influx assays.

RESULTS

Depressive and anxiety symptoms significantly worsened with increasing numbers of minor HTR3C c.489C>A alleles in the dominant model (F depressive = 7.475, P depressive = 0.006; F anxiety = 6.535, P anxiety = 0.011). A higher SNP score (range 0-6) was linked to a worsened depressive symptoms score (F = 7.710, P-linear trend = 0.006) in IBS. The potential relevance of the HTR3C SNP was corroborated, showing changes in the expression level of 5-HT3AC variant receptors.

CONCLUSION

We have provided the first evidence that HTR3C c.489C>A is involved in depressive and anxiety symptoms in individuals with IBS. The SNP score indicated that an increasing number of minor alleles is linked to the worsening of depressive symptoms in IBS.

The serotonin receptor 3E variant is a risk factor for female IBS-D

Irritable bowel syndrome (IBS) is a gut-brain disorder of multifactorial origin. Evidence of disturbed serotonergic function in IBS accumulated for the 5-HT₃ receptor family. 5-HT₃Rs are encoded by HTR3 genes and control GI function, and peristalsis and secretion, in particular. Moreover, 5-HT₃R antagonists are beneficial in the treatment of diarrhea predominant IBS (IBS-D). We previously reported on functionally relevant SNPs in HTR3A c.-42C > T (rs1062613), HTR3C p.N163K (rs6766410), and HTR3E c.*76G > A (rs56109847 = rs62625044) being associated with IBS-D, and the HTR3B variant p.Y129S (rs1176744) was also described within the context of IBS. We performed a multi-center study to validate previous results and provide further evidence for the relevance of HTR3 genes in IBS pathogenesis. Therefore, genotype data of 2682 IBS patients and 9650 controls from 14 cohorts (Chile, Germany (2), Greece, Ireland, Spain, Sweden (2), the UK (3), and the USA (3)) were taken into account. Subsequent meta-analysis confirmed HTR3E c.*76G > A (rs56109847 = rs62625044) to be associated with female IBS-D (OR = 1.58; 95% CI (1.18, 2.12)). Complementary expression studies of four GI regions (jejunum, ileum, colon, sigmoid colon) of 66 IBS patients and 42 controls revealed only HTR3E to be robustly expressed. On top, HTR3E transcript levels were significantly reduced in the sigma of IBS patients (p = 0.0187); more specifically, in those diagnosed with IBS-D (p = 0.0145). In conclusion, meta-analysis confirmed rs56109847 = rs62625044 as a risk factor for female IBS-D. Expression analysis revealed reduced HTR3E levels in the sigmoid colon of IBS-D patients, which underlines the relevance of HTR3E in the pathogenesis of IBS-D.

An Update in Our Understanding of the Relationships Between Gene Polymorphisms and Chemotherapy-Induced Nausea and Vomiting

The occurrence and severity of chemotherapy-induced nausea and vomiting (CINV) are influenced by many factors; this includes therapeutic factors, such as the dose, administration mode, and chemotherapeutic agent emetogenicity, as well as patient-related risk factors, such as the gender, age, alcohol consumption history, and anxiety level. However, these factors cannot fully explain the individual CINV differences. In recent years, the correlation between gene polymorphism and CINV has been a hot research topic; the present paper reviews current research on CINV-related gene polymorphisms, and the results indicate that the use of gene polymorphism for the optimization of CINV efficacy is of important clinical significance.

Uncovering the pathophysiology of irritable bowel syndrome by exploring the gut-brain axis: a narrative review

Objective

To improve the pathophysiological understanding of irritable bowel syndrome (IBS) by exploring the gut-brain axis.

Background

Disorders of gut-brain interaction (DGBIs) are gastrointestinal (GI) disorders in which alterations in bowel functions occur. IBS, which is one of the most studied DGBIs, is linked with abdominal distress or pain without obvious structural or biochemical anomalies.

Methods

The etiology of IBS has not been clearly described but is known to be multifactorial, involving GI motility changes, post-infectious reactivity, visceral hypersensitivity, gut-brain interactions, microbiota dysbiosis, small intestinal bacterial overgrowth, food sensitivity, carbohydrate malabsorption, and intestinal inflammation.

Conclusions

One of the main features of IBS is the occurrence of structural and functional disruptions in the gut-brain axis, which alter reflective and perceptual nervous system reactions. Herein, we provide a brief summary of this topic. Furthermore, we discuss animal models, which are important in the study of IBS, especially as it is linked with stressors. These animal models cannot fully represent the human disease but serve as important tools for understanding this complicated disorder. In the future, technologies, such as organ-on-a-chip models and metabolomics, will provide novel information regarding the pathophysiology of IBS, which will play an important role in treatment development. Finally, we take a brief glance at how acupuncture treatments may hold potential for patients with IBS.

Cerebral Organoids Derived from a Parkinson's Patient Exhibit Unique Pathogenesis from Chikungunya Virus Infection When Compared to a Non-Parkinson's Patient

(1) Background: Arboviruses of medical and veterinary significance have been identified on all seven continents, with every human and animal population at risk for exposure. Like arboviruses, chronic neurodegenerative diseases, like Alzheimer’s and Parkinson’s disease, are found wherever there are humans. Significant differences in baseline gene and protein expression have been determined between human-induced pluripotent stem cell lines derived from non-Parkinson’s disease individuals and from individuals with Parkinson’s disease. It was hypothesized that these inherent differences could impact cerebral organoid responses to viral infection. (2) Methods: In this study, cerebral organoids from a non-Parkinson’s and Parkinson’s patient were infected with Chikungunya virus and observed for two weeks. (3) Results: Parkinson’s organoids lost mass and exhibited a differential antiviral response different from non-Parkinson’s organoids. Neurotransmission data from both infected non-Parkinson’s and Parkinson’s organoids had dysregulation of IL-1, IL-10, and IL-6. These cytokines are associated with mood and could be contributing to persistent depression seen in patients following CHIKV infection. Both organoid types had increased expression of CXCL10, which is linked to demyelination. (4) Conclusions: The differential antiviral response of Parkinson’s organoids compared with non-Parkinson’s organoids highlights the need for more research in neurotropic infections in a neurologically compromised host.

Delineation of the functional properties exhibited by the Zinc-Activated Channel (ZAC) and its high-frequency Thr128Ala variant (rs2257020) in Xenopus oocytes

The signalling characteristics of the Zinc-Activated Channel (ZAC), a member of the Cys-loop receptor (CLR) superfamily, are presently poorly elucidated. The ZACN polymorphism c.454G>A encoding for the Thr¹²⁸Ala variation in ZAC is found in extremely high allele frequencies across ethnicities. In this, the first study of ZAC in Xenopus oocytes by TEVC electrophysiology, ZAC^Thr128 and ZAC^Ala128 exhibited largely comparable pharmacological and signalling characteristics, but interestingly the Zn²⁺- and H⁺-evoked current amplitudes in ZAC^Ala128-oocytes were dramatically smaller than those in ZAC^Thr128-oocytes. While the variation thus appeared to impact cell surface expression and/or channel properties of ZAC, the similar expression properties exhibited by ZAC^Thr128 and ZAC^Ala128 in transfected mammalian cells indicated that their distinct functionalities could arise from the latter. In co-expression experiments, wild-type and variant ZAC subunits assembled efficiently into "heteromeric" complexes in HEK293 cells, while the concomitant presence of ZAC^Ala128 in ZAC^Thr128:ZAC^Ala128-oocytes did not exert a dominant negative effect on agonist-evoked current amplitudes compared to those in ZAC^Thr128-oocytes. Finally, the structural determinants of the functional importance of the 1-hydroxyethyl side-chain of Thr¹²⁸ appeared to be subtle, as agonist-evoked current amplitudes in ZAC^Ser128-, ZAC^Val128- and ZAC^Ile128-oocytes also were substantially lower than those in ZAC^Thr128-oocytes. In conclusion, the functional properties exhibited by ZAC in this work substantiate the notion of it being an atypical CLR. While the impact of the Thr¹²⁸Ala variation on ZAC functionality in oocytes is striking, it remains to be investigated whether and to which extent this translates into an in vivo setting and thus could constitute a source of inter-individual variation in ZAC physiology.

A history of severe nausea and vomiting during pregnancy predicts a higher incidence of postoperative nausea and vomiting after breast cancer surgery without breast reconstruction

BACKGROUND

Postoperative nausea and vomiting (PONV) occur in up to 30 percent of patients after breast cancer surgery despite routine administration of antiemetic prophylaxis. A history of nausea and vomiting during pregnancy (NVP) has been reported as a risk factor of intraoperative nausea and vomiting in caesarean delivery. Nevertheless, whether a history of severe nausea and vomiting during pregnancy (SNVP) is associated with a higher occurrence of PONV remains unclear.

METHODS

In this study, 121 sequential female patients who were scheduled to undergo breast cancer surgery were assigned to study group (30 cases, with SNVP) or control group (91 cases, with mild NVP (MNVP)). The incidence of PONV and the need for rescue antiemetic were recorded in post-anesthesia care unit (PACU), at 6 h, 12 h, 24 h, and 36 h after operation. Moreover, postoperative pain, level of satisfaction, and the relationship of ER/PR status in breast cancer tissue with SNVP and PONV were also investigated.

RESULTS

Data from 115 patients were analyzed. The incidence of PONV in the SNVP group was significantly higher than that in the MNVP group at 6 h (P < 0.005), 12 h (P < 0.05), and 24 h after the operation (P < 0.05). The incidence of PONV in the MNVP group was approximately 30% lower than in the SNVP group. Besides, more severe PONV, a larger number of demands for rescue antiemetic, fewer patient satisfaction scores, and more dizziness were observed in the SNVP group. Yet, no relationship was found between ER/PR status of breast cancer tissue and SNVP or PONV.

CONCLUSIONS

Compared to patients with MNVP, those with a history of SNVP experienced a higher incidence of PONV and severe PONV, presented with a larger number of requirements for postoperative antiemetic and a lower level of satisfaction.

Discrimination of alcohol dependence based on the convolutional neural network

In this paper, a total of 20 sites of single nucleotide polymorphisms (SNPs) on the serotonin 3 receptor A gene (HTR3A) and B gene (HTR3B) are used for feature fusion with age, education and marital status information, and the grid search-support vector machine (GS-SVM), the convolutional neural network (CNN) and the convolutional neural network combined with long and short-term memory (CNN-LSTM) are used to classify and discriminate between alcohol-dependent patients (AD) and the non-alcohol-dependent control group. The results show that 19 SNPs combined with academic qualifications have the best discrimination effect. In the GS-SVM, the area under the receiver operating characteristic (ROC) curve (AUC) is 0.87, the AUC of CNN-LSTM is 0.88, and the performance of the CNN model is the best, with an AUC of 0.92. This study shows that the CNN model can more accurately discriminate AD than the SVM to treat patients in time.

Pharmacogenetics and the treatment of functional gastrointestinal disorders

The diagnosis and management of functional gastrointestinal disorders (FGIDs) remain very challenging. In the era of precision medicine, it is important to individualize the treatment of these conditions by providing targeted and effective therapies while minimizing the risk of medication side effects. By using genetic information that predicts and affects the responses to specific medications, it is anticipated that the science of pharmacogenetics in FGIDs will advance the practice of precision medicine. The pathophysiology of FGIDs is complex, involving the interaction between predisposing genetic and environmental factors. Studies have shown that genetic polymorphisms may contribute to the variable responses to specific medications among individuals with FGIDs. Genetic variations in the CYP450 system can affect the metabolism and, hence, the pharmacokinetics of drugs used to treat FGIDs. Polymorphisms in the genes controlling proteins that are involved in the direct action of medications targeting the serotonergic, cannabinoid, adrenergic and bile acid pathways can affect the pharmacologic effects of the medications. In this review, we summarize the published literature on the pharmacogenetics of FGIDs and address the potential clinical utility and future challenges in this field. Since it was the dominant topic in the majority of the articles relevant to FGIDs, our review will focus on irritable bowel syndrome.