Neuropeptide and steroid hormone mediators of neuroendocrine regulation

Differentiation of steroid isomers by steroid analogues adducted trapped ion mobility spectrometry-mass spectrometry

Steroids are one of the important indicators of health and disease. However, due to the high similarity of steroid structures, there are several potential obstacles in the differentiation of steroids, especially for their isomers. Herein, we described a trapped ion mobility spectrometry-mass spectrometry (TIMS-MS) approach based on the steroid analogue adduction for isomer-specific identification of steroids. The application of dexamethasone (DEX) to form heterodimers with steroids enhanced the separation of their isomers in TIMS. Two isomer pairs including 17-hydroxyprogesterone/11-deoxycorticosterone and androsterone/epiandrosterone were successfully separated as the heterodimers with DEX by TIMS. The stability of DEX-adducted heterodimers is comparable with steroid dimers. Owing to the high separation efficiency and stability, the relative quantification of steroid isomers was demonstrated with the proposed method.

Neuropeptides and hormones in hypothalamus-pituitary axis of Chinese sturgeon (Acipenser sinensis)

The hypothalamus and pituitary serve as important neuroendocrine center, which is able to secrete a variety of neuropeptides and hormones to participate in the regulation of reproduction, growth, stress and feeding in fish. Chinese sturgeon is a basal vertebrate lineage fish with a special evolutionary status, but the information on its neuroendocrine system is relatively scarce. Using the transcriptome data on the hypothalamus-pituitary axis of Chinese sturgeon as reference, we found out 46 hypothalamus neuropeptide genes, which were involved in regulation of reproduction, growth, stress and feeding. The results of sequence alignment showed that the neuroendocrine system of Chinese sturgeon evolves slowly, which confirms that Chinese sturgeon is a species with a slow phenotypic evolution rate. In addition, we also isolated six pituitary hormones genes from Chinese sturgeon, including reproductive hormones: follicle-stimulating homone (FSH) and luteinizing hormone (LH), growth-related hormones: growth hormone (GH)/prolactin (PRL)/somatolactin (SL), and stress-related hormone gene: proopiomelanocortin (POMC). Similar to teleost, immunostaining localization analysis in Chinese sturgeon pituitary showed that LH and FSH were located in the pituitary proximal pars distalis, SL was located in the pituitary rostral pars distalis, and POMC was located in the pituitary pars intermedia and pituitary rostral pars distalis. This study will give a contribution to enrich our information on the neuroendocrine system in Chinese sturgeon.

The exercise-induced inflammatory response in inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

This study investigated selected inflammatory responses to acute and chronic exercise in individuals with inflammatory bowel disease (IBD).

METHODS

A systematic review and meta-analysis was conducted on all relevant exercise-based intervention publications with IBD participants. The study included articles that utilised a broad range of acute and chronic exercise interventions, with inflammatory biomarkers measured and symptoms documented, both pre- and post-exercise for those with IBD. The search was limited to studies published in English, the use of human participants, and primary studies, with no restrictions on date of publication or participant's age. Articles were retrieved through the electronic databases: PubMed, SPORTDiscus, and Scopus. This study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

Six inflammatory markers were included in the meta-analysis which consisted of five studies. Exercise interventions resulted in no significant difference in IL-6 (SMD = -0.09; 95% CI = -0.49, 0.30; P = 0.64), TNF-α (SMD = 0.08; 95% CI = -0.31, 0.48; P = 0.68), CRP (SMD = -0.04; 95% CI = -0.58, 0.50; P = 0.89), IL-17 (SMD = 0.15; 95% CI = -0.45, 0.76; P = 0.62), leukocytes (SMD = 0.40; 95% CI = -0.53, 1.33; P = 0.40) or lymphocytes (SMD = 0.32; 95% CI = -0.33, 0.97; P = 0.33), thus, indicating exercise may have no effect on inflammatory markers in IBD. Bowel symptoms improved following regular moderate exercise that incorporated stress management.

CONCLUSION

Heterogeneity among the identified literature may have led to exercise interventions being ineffective in reducing inflammation. Although the limited number of eligible studies may reduce the reliability of results, it emphasises the need for additional research in this domain. Importantly, no adverse symptomatic responses to exercise indicate that exercise is safe for IBD patients.

An Assay on the Possible Effect of Essential Oil Constituents on Receptors Involved in Women's Hormonal Health and Reproductive System Diseases

Aromatic herbal remedies, hydrosols, and essential oils are widely used for women's hormonal health. Scientific investigation of their major constituents may prevent unwanted infertility cases, fetal abnormalities, and drug-herb interactions. It also may lead to development of new medications. A list of 265 volatile molecules (mainly monoterpenes and sesquiterpenes) were prepared from a literature survey in Scopus and PubMed (2000-2019) on hydrosols and essential oils that are used for women's hormonal and reproductive health conditions. The PDB (protein data bank) files of the receptors (136 native PDB files) that involve with oxytocin, progesterone, estrogen, prolactin, acetyl choline, androgen, dopamine, human chorionic gonadotropin, luteinizing hormone, follicle-stimulating hormone, aromatase, and HER2 receptors were downloaded from Protein Data Bank. An in silico study using AutoDock 4.2 and Vina in parallel mode was performed to investigate possible interactions of the ligands with the receptors. Drug likeliness was investigated for the most active molecules using DruLiTo software. Aristola-1(10),8-diene, bergapten (5-methoxypsoralen), α-bergamotene, bicyclogermacrene, α-bisabolol oxide A, α-bisabolone oxide, p-cymen-8-ol, 10-epi elemol, α-elemol, β-eudesmol, 7-epi-β-eudesmol, ficusin, β-humulene, methyl jasmonate, nerolidol, pinocarvone, (+)-spathulenol, and thujone had better interactions with some androgen, aromatase, estrogen, progesterone, HER2, AChR, and/or dopamine receptors. Most of these molecules had an acceptable drug likeliness except for α-bergamotene, bicyclogermacrene, β-humulene, and aristola-1(10),8-diene. Some volatile natural molecules can be considered as lead compound for drug development to treat hormonal conditions.

Effect of early life social adversity on drug abuse vulnerability: Focus on corticotropin-releasing factor and oxytocin

Early life adversity can set the trajectory for later psychiatric disorders, including substance use disorders. There are a host of neurobiological factors that may play a role in the negative trajectory. The current review examines preclinical evidence suggesting that early life adversity specifically involving social factors (maternal separation, adolescent social isolation and adolescent social defeat) may influence drug abuse vulnerability by strengthening corticotropin-releasing factor (CRF) systems and weakening oxytocin (OT) systems. In adulthood, pharmacological and genetic evidence indicates that both CRF and OT systems are directly involved in drug reward processes. With early life adversity, numerous studies show an increase in drug abuse vulnerability measured in adulthood, along a concomitant strengthening of CRF systems and a weakening of OT systems. Mechanistic studies, while relatively few in number, are generally consistent with the theme that strengthened CRF systems and weakened OT systems mediate, at least in part, the link between early life adversity and drug abuse vulnerability. Establishing a direct role of CRF and OT in mediating the relation between early life social stressors and drug abuse vulnerability will inform clinical researchers and practitioners toward the development of intervention strategies to reduce risk among those suffering from early life adversities. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

Corticotropin-releasing factor neurotransmission in the lateral hypothalamus modulates the tachycardiac response during acute emotional stress in rats

The lateral hypothalamus (LH) is implicated in the physiological and behavioral responses during stressful events. However, the local neurochemical mechanisms related to control of stress responses by this hypothalamic area are not completely understood. Therefore, in this study we evaluated the involvement of CRFergic neurotransmission acting through the CRF₁ receptor within the LH in cardiovascular responses evoked by an acute session of restraint stress in rats. For this, we investigated the effect of bilateral microinjection of different doses (0.01, 0.1 and 1 nmol/100 nL) of the selective CRF₁ receptor antagonist CP376395 into the LH on arterial pressure and heart rate increases and decrease in tail skin temperature evoked by acute restraint stress. We found that all doses of the CRF₁ receptor antagonist microinjected into the LH decreased the restraint-evoked tachycardia, but without affecting the arterial pressure and tail skin temperature responses. Additionally, treatment of the LH with CP376395 at the doses of 0.1 and 1 nmol/100 nL increased the basal values of both heart rate and arterial pressure, whereas the dose of 0.1 nmol/100 nL decreased the skin temperature. Taken together, these findings indicate that CRFergic neurotransmission in the LH, acting through activation of local CRF₁ receptors, plays a facilitatory role in the tachycardia observed during aversive threats, but without affecting the pressor and tail skin temperature responses. Our results also provide evidence that LH CRFergic neurotransmission in involved in tonic maintenance of cardiovascular function.

Isolation and characterization of glycosylated neuropeptides

Glycosylation is one of the most ubiquitous and complex post-translational modifications (PTMs). It plays pivotal roles in various biological processes. Studies at the glycopeptide level are typically considered as a downstream work resulting from enzymatic digested glycoproteins. Less attention has been focused on glycosylated endogenous signaling peptides due to their low abundance, structural heterogeneity and the lack of enabling analytical tools. Here, protocols are presented to isolate and characterize glycosylated neuropeptides utilizing nanoflow liquid chromatography coupled with mass spectrometry (LC-MS). We first demonstrate how to extract neuropeptides from raw tissues and perform further separation/cleanup before MS analysis. Then we describe hybrid MS methods for glycosylated neuropeptide profiling and site-specific analysis. We also include recommendations for data analysis to identify glycosylated neuropeptides in crustaceans where a complete neuropeptide database is still lacking. Other strategies and future directions are discussed to provide readers with alternative approaches and further unravel biological complexity rendered by glycosylation.