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BioRxiv : the Preprint Server For... Oct 2023The central amygdala (CeA) and bed nucleus of the stria terminalis (BNST) are reciprocally connected nodes of the extended amygdala thought to play an important role in...
The central amygdala (CeA) and bed nucleus of the stria terminalis (BNST) are reciprocally connected nodes of the extended amygdala thought to play an important role in alcohol consumption. Studies of immediate-early genes indicate that BNST and CeA are acutely activated following alcohol drinking and may signal alcohol reward in nondependent drinkers, while increased stress signaling in the extended amygdala following chronic alcohol exposure drives increased drinking via negative reinforcement. However, the temporal dynamics of neuronal activation in these regions during drinking behavior are poorly understood. In this study, we used fiber photometry and the genetically encoded calcium sensor GCaMP6s to assess acute changes in neuronal activity during alcohol consumption in BNST and CeA before and after a chronic drinking paradigm. Activity was examined in the pan-neuronal population and separately in dynorphinergic neurons. BNST and CeA showed increased pan-neuronal activity during acute consumption of alcohol and other fluid tastants of positive and negative valence, as well as highly palatable chow. Responses were greatest during initial consummatory bouts and decreased in amplitude with repeated consumption of the same tastant, suggesting modulation by stimulus novelty. Dynorphin neurons showed similar consumption-associated calcium increases in both regions. Following three weeks of continuous alcohol access (CA), calcium increases in dynorphin neurons during drinking were maintained, but pan-neuronal activity and BNST-CeA coherence were altered in a sex-specific manner. These results indicate that BNST and CeA, and dynorphin neurons specifically, are engaged during drinking behavior, and activity dynamics are influenced by stimulus novelty and chronic alcohol.
PubMed: 37873188
DOI: 10.1101/2023.10.10.561741 -
Ageing Research Reviews Dec 2023The Kisspeptin1 (KISS1)/neurokinin B (NKB)/Dynorphin (Dyn) [KNDy] neurons in the hypothalamus regulate the reproduction stage in human beings and rodents. KNDy neurons... (Review)
Review
The Kisspeptin1 (KISS1)/neurokinin B (NKB)/Dynorphin (Dyn) [KNDy] neurons in the hypothalamus regulate the reproduction stage in human beings and rodents. KNDy neurons co-expressed all KISS1, NKB, and Dyn peptides, and hence commonly regarded as KISS1 neurons. KNDy neurons contribute to the "GnRH pulse generator" and are implicated in the regulation of pulsatile GnRH release. The estradiol (E2)-estrogen receptor (ER) interactions over GnRH neurons in the hypothalamus cause nitric oxide (NO) discharge, in addition to presynaptic GABA and glutamate discharge from respective neurons. The released GABA and glutamate facilitate the activity of GnRH neurons via GABAA-R and AMPA/kainate-R. The KISS1 stimulates MAPK/ERK1/2 signaling and cause the release of Ca from intracellular store, which contribute to neuroendocrine function, increase apoptosis and decrease cell proliferation and metastasis. The ageing in women deteriorates KISS1/KISS1R interaction in the hypothalamus which causes lower levels of GnRH. Because examining the human brain is so challenging, decades of clinical research have failed to find the causes of KNDy/GnRH dysfunction. The KISS1/KISS1R interactions in the brain have a neuroprotective effect against Alzheimer's disease (AD). These findings modulate the pathophysiological role of the KNDy/GnRH neural network in polycystic ovarian syndrome (PCOS) associated with ageing and, its protective role in cancer and AD. This review concludes with protecting effect of the steroid-derived acute regulatory enzyme (StAR) against neurotoxicity in the hippocampus, and hypothalamus, and these measures are fundamental for delaying ageing with PCOS. StAR could serve as novel diagnostic marker and therapeutic target for the most prevalent hormone-sensitive breast cancers (BCs).
Topics: Animals; Female; Humans; Alzheimer Disease; Arcuate Nucleus of Hypothalamus; Dynorphins; gamma-Aminobutyric Acid; Glutamates; Gonadotropin-Releasing Hormone; Kisspeptins; Neurokinin B; Polycystic Ovary Syndrome; Receptors, Kisspeptin-1; Rodentia
PubMed: 37821047
DOI: 10.1016/j.arr.2023.102086 -
BioRxiv : the Preprint Server For... Sep 2023Binding events to elements of the cell membrane act as receptors which regulate cellular function and communication and are the targets of many small molecule drug...
Binding events to elements of the cell membrane act as receptors which regulate cellular function and communication and are the targets of many small molecule drug discovery efforts for agonists and antagonists. Conventional techniques to probe these interactions generally require labels and large amounts of receptor to achieve satisfactory sensitivity. Whispering gallery mode microtoroid optical resonators have demonstrated sensitivity to detect single-molecule binding events. Here, we demonstrate the use of frequency-locked optical microtoroids for characterization of membrane interactions at zeptomolar concentrations using a supported biomimetic membrane. Arrays of microtoroids were produced using photolithography and subsequently modified with a biomimetic membrane, providing high quality (Q) factors () in aqueous environments. Fluorescent recovery after photobleaching (FRAP) experiments confirmed the retained fluidity of the microtoroid supported-lipid membrane with a diffusion coefficient of . Utilizing this frequency-locked membrane-on-a-chip model combined with auto-balanced detection and non-linear post-processing techniques, we demonstrate zeptomolar detection levels The binding of Cholera Toxin B- monosialotetrahexosyl ganglioside (GM1) was monitored in real-time, with an apparent equilibrium dissociation constant . The measured affiny of the agonist dynorphin A 1-13 to the -opioid receptor revealed a using the same approach. Radioligand binding competition with dynorphin A 1-13 revealed a in agreement (1.1 nM) with the unlabeled method. The biosensing platform reported herein provides a highly sensitive real-time characterization of membrane embedded protein binding kinetics, that is rapid and label-free, for toxin screening and drug discovery, among other applications.
PubMed: 37786702
DOI: 10.1101/2023.09.20.558657 -
Brain Research Dec 2023Levels of the opioid peptide dynorphin, an endogenous ligand selective for kappa-opioid receptors (KORs), its mRNA and pro-peptide precursors are differentially...
Levels of the opioid peptide dynorphin, an endogenous ligand selective for kappa-opioid receptors (KORs), its mRNA and pro-peptide precursors are differentially dysregulated in Parkinson's disease (PD) and following the development of l-DOPA-induced dyskinesia (LID). It remains unclear whether these alterations contribute to the pathophysiological mechanisms underlying PD motor impairment and the subsequent development of LID, or whether they are part of compensatory mechanisms. We sought to investigate nor-BNI, a KOR antagonist, 1) in the dopamine (DA)-depleted PD state, 2) during the development phase of LID, and 3) via measuring of tonic levels of striatal DA. While nor-BNI (3 mg/kg; s.c.) did not lead to functional restoration in the DA-depleted state, it affected the dose-dependent development of abnormal voluntary movements (AIMs) in response to escalating doses of l-DOPA in a rat PD model with a moderate striatal 6-hydroxdopamine (6-OHDA) lesion. We tested five escalating doses of l-DOPA (6, 12, 24, 48, 72 mg/kg; i.p.), and nor-BNI significantly increased the development of AIMs at the 12 and 24 mg/kg l-DOPA doses. However, after reaching the 72 mg/kg l-DOPA, AIMs were not significantly different between control and nor-BNI groups. In summary, while blocking KORs significantly increased the rate of development of LID induced by chronic, escalating doses of l-DOPA in a moderate-lesioned rat PD model, it did not contribute further once the overall severity of LID was established. While we observed an increase of tonic DA levels in the moderately lesioned dorsolateral striatum, there was no tonic DA change following administration of nor-BNI.
Topics: Rats; Animals; Levodopa; Dopamine; Receptors, Opioid, kappa; Rats, Sprague-Dawley; Dyskinesia, Drug-Induced; Parkinson Disease; Corpus Striatum; Oxidopamine; Disease Models, Animal
PubMed: 37783263
DOI: 10.1016/j.brainres.2023.148613 -
Endocrinology Sep 2023The current model for the synchronization of GnRH neural activity driving GnRH and LH pulses proposes that a set of arcuate (ARC) neurons that contain kisspeptin,...
The current model for the synchronization of GnRH neural activity driving GnRH and LH pulses proposes that a set of arcuate (ARC) neurons that contain kisspeptin, neurokinin B, and dynorphin (KNDy neurons) is the GnRH pulse generator. This study tested the functional role of ovine KNDy neurons in pulse generation and explored the roles of nearby Kiss1 receptor (Kiss1R)-containing cells using lesions produced with saporin (SAP) conjugates. Injection of NK3-SAP ablated over 90% of the KNDy cells, while Kiss-SAP (saporin conjugated to kisspeptin-54) lesioned about two-thirds of the Kiss1R population without affecting KNDy or GnRH cell number. Both lesions produced a dramatic decrease in LH pulse amplitude but had different effects on LH pulse patterns. NK3-SAP increased interpulse interval, but Kiss-SAP did not. In contrast, Kiss-SAP disrupted the regular hourly occurrence of LH pulses, but NK3-SAP did not. Because Kiss1R is not expressed in KNDy cells, HiPlex RNAScope was used to assess the colocalization of 8 neurotransmitters and 3 receptors in ARC Kiss1R-containing cells. Kiss1R cells primarily contained transcript markers for GABA (68%), glutamate (28%), ESR1 (estrogen receptor-α) mRNA, and OPRK1 (kappa opioid receptor) mRNA. These data support the conclusion that KNDy neurons are essential for GnRH pulses in ewes, whereas ARC Kiss1R cells are not but do maintain the amplitude and regularity of GnRH pulses. We thus propose that in sheep, ARC Kiss1R neurons form part of a positive feedback circuit that reinforces the activity of the KNDy neural network, with GABA or glutamate likely being involved.
Topics: Animals; Female; Arcuate Nucleus of Hypothalamus; Dynorphins; gamma-Aminobutyric Acid; Glutamates; Gonadotropin-Releasing Hormone; Kisspeptins; Neurokinin B; Neurons; Receptors, Kisspeptin-1; RNA, Messenger; Saporins; Sheep; Luteinizing Hormone
PubMed: 37776515
DOI: 10.1210/endocr/bqad148 -
American Journal of Translational... 2023To analyze the effects of transcutaneous electrical nerve stimulation (TENS) combined with levofloxacin (0.1 g, twice daily) and tamsulosin (0.2 mg, once daily) on...
Transcutaneous electrical nerve stimulation combined with levofloxacin and tamsulosin for patients with chronic prostatitis: clinical efficacy and changes in serum factors.
OBJECTIVE
To analyze the effects of transcutaneous electrical nerve stimulation (TENS) combined with levofloxacin (0.1 g, twice daily) and tamsulosin (0.2 mg, once daily) on clinical efficacy and serum factors in patients with chronic prostatitis (CP).
METHODS
A retrospective analysis was conducted on 105 patients with CP who received treatment at Hangzhou Lin'an District Hospital of Traditional Chinese Medicine from February 2020 to December 2022. Among them, 47 patients received levofloxacin and tamsulosin were included in a drug group (DG), and 58 patients received additional TENS therapy (frequency: 1/4/1 Hz+80/120/80 Hz; pulse width: 270/230/270 μs+120/80/120 μs; waveform: square and continuous waveforms) were included in a joint group (JG). The changes in the National Institutes of Health chronic prostatitis symptom index (NIH-CPSI), international prostate symptom score (IPSS), and the levels of inflammatory and pain-causing factors were compared between the two groups before and after treatment. The clinical efficacy was compared between the two groups after treatment. Moreover, the incidence of adverse reactions was compared between the two groups.
RESULTS
After treatment, the scores of NIH-CPSI and IPSS, and the levels of IL-6, CRP, TNF-α, IL-1β, 5-hydroxytryptamine, substance P, and dynorphin in the JG were obviously lower than those in the DG (P<0.001). The clinical response rate in the DG was obviously lower than that in the JG (P=0.006, Table 2). There was no difference in total incidence of adverse reactions between the two groups (P=0.801).
CONCLUSION
Compared to medication alone (levofloxacin and tamsulosin), the combination of TENS with levofloxacin and tamsulosin can reduce the levels of inflammatory and pain-causing factors in patients, and improve the efficacy. Importantly, it has been observed that this combination therapy does not lead to an increase in adverse reactions and is considered to be safe for patients.
PubMed: 37692965
DOI: No ID Found -
Biology of Reproduction Nov 2023Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal...
Maternal cafeteria diet influences kisspeptin (Kiss1), kisspeptin receptor(Gpr54), and sirtuin (Sirt1) genes, hormonal and metabolic profiles, and reproductive functions in rat offspring in a sex-specific manner†.
Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal axis. KP acts together with dynorphin A (encoded by Pdyn) and neurokinin B (encoded by Tac2) to regulate reproduction. KP is crucial for the onset of puberty and is under the control of sirtuin (encoded by Sirt1). We hypothesize that the maternal cafeteria (CAF) diet has adverse effects on the offspring's hormonal, metabolic, and reproductive functions due to sex-specific alterations in the expression of Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 in the hypothalamus, and Kiss1, Gpr54, and Sirt1 in the liver. Rats were fed a CAF diet before pregnancy, during pregnancy, and during lactation. The vaginal opening was monitored. Offspring were sacrificed in three age points: PND 30, PND 35, and PND 60 (females) and PND 40, PND 45, and PND 60 (males). Their metabolic and hormonal status was assessed. mRNA for Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 were measured by real-time PCR in the hypothalamus and/or livers. We found that CAF offspring had lower weight and altered body composition; increased cholesterol and triglyceride levels, sex-specific changes in glucose and insulin levels; sex-dependent changes in Sirt1/Kiss1 mRNA ratio in the hypothalamus; sex-specific alterations in Kiss1 and Sirt1 mRNA in the liver with more diversity in males; and a delayed puberty onset in females. We concluded that the mother's CAF diet leads to sex-specific alterations in metabolic and reproductive outcomes via Kiss1/Gpr54 and Sirt1 systems in offspring.
Topics: Pregnancy; Female; Male; Rats; Animals; Kisspeptins; Sirtuin 1; Sexual Maturation; Receptors, Kisspeptin-1; Diet; Metabolome; RNA, Messenger
PubMed: 37665248
DOI: 10.1093/biolre/ioad101 -
Addiction Biology Sep 2023Chronic exposure to methamphetamine (METH) causes severe and persistent cognitive impairment. The present study aimed to investigate the role of dynorphin/κ opioid...
Chronic exposure to methamphetamine (METH) causes severe and persistent cognitive impairment. The present study aimed to investigate the role of dynorphin/κ opioid receptor (KOR) system in the development of METH-induced cognitive impairment. We found that mice showed significant cognitive impairment in the novel object recognition test (NOR) following daily injections of METH (10 mg/kg) for seven consecutive days. Systemic blockade of KOR prevented METH-induced cognitive impairment by pretreatment of the selective KOR antagonist norBNI (10 mg/kg, i.p.) or KOR deletion. Then, significant increased dynorphin and KOR mRNA were observed exclusively in prelimbic cortex (PL) other than infralimbic cortex. Finally, microinjection with norBNI into PL also improved cognitive memory in METH-treated mice using NOR and spontaneous alternation behaviour test. Our results demonstrated that dynorphin/KOR system activation in PL may be a possible mechanism for METH-induced cognitive impairment and shed light on KOR antagonists as a potential neuroprotective agent against the cognitive deficits induced by drug abuse.
Topics: Animals; Mice; Dynorphins; Receptors, Opioid, kappa; Cognitive Dysfunction; Cognition Disorders; Methamphetamine; Narcotic Antagonists
PubMed: 37644896
DOI: 10.1111/adb.13323 -
Molecular Psychiatry Nov 2023The medial prefrontal cortex (mPFC) controls behavior via connections with limbic excitatory afferents that engage various inhibitory motifs to shape mPFC circuit...
The medial prefrontal cortex (mPFC) controls behavior via connections with limbic excitatory afferents that engage various inhibitory motifs to shape mPFC circuit function. The dynorphin (Dyn) / kappa-opioid receptor (KOR) system is highly enriched in the mPFC, and its dysregulation is implicated in neuropsychiatric disorders. However, it is unclear how the Dyn / KOR system modulates excitatory and inhibitory circuits that are integral for mPFC information processing and behavioral control. Here, we provide a circuit-based framework wherein mPFC Dyn / KOR signaling regulates excitation-inhibition balance by toggling which afferents drive mPFC neurons. Dyn / KOR regulation of afferent inputs is pathway-specific. Dyn acting on presynaptic KORs inhibits glutamate release from afferent inputs to the mPFC, including the basolateral amygdala (BLA), paraventricular nucleus of the thalamus, and contralateral cortex. The majority of excitatory synapses to mPFC neurons, including those from the ventral hippocampus (VH), do not express presynaptic KOR, rendering them insensitive to Dyn / KOR modulation. Dyn / KOR signaling also suppresses afferent-driven recruitment of specific inhibitory sub-networks, providing a basis for Dyn to disinhibit mPFC circuits. Specifically, Dyn / KOR signaling preferentially suppresses SST interneuron- relative to PV interneuron-mediated inhibition. Selective KOR action on afferents or within mPFC microcircuits gates how distinct limbic inputs drive spiking in mPFC neurons. Presynaptic Dyn / KOR signaling decreases KOR-positive input-driven (e.g. BLA) spiking of mPFC neurons. In contrast, KOR-negative input recruitment of mPFC neurons is enhanced by Dyn / KOR signaling via suppression of mPFC inhibitory microcircuits. Thus, by acting on distinct circuit elements, Dyn / KOR signaling shifts KOR-positive and negative afferent control of mPFC circuits, providing mechanistic insights into the role of neuropeptides in shaping mPFC function. Together, these findings highlight the utility of targeting the mPFC Dyn / KOR system as a means to treat neuropsychiatric disorders characterized by dysregulation in mPFC integration of long-range afferents with local inhibitory microcircuits.
Topics: Dynorphins; Receptors, Opioid, kappa; Prefrontal Cortex; Neurons; Basolateral Nuclear Complex
PubMed: 37644172
DOI: 10.1038/s41380-023-02226-5 -
Journal of Medicinal Chemistry Sep 2023The κ-opioid receptor (KOR) is an attractive target for the development of novel drugs. KOR agonists are potentially safer pain medications, whereas KOR antagonists are...
The κ-opioid receptor (KOR) is an attractive target for the development of novel drugs. KOR agonists are potentially safer pain medications, whereas KOR antagonists are promising drug candidates for the treatment of neuropsychiatric disorders. Hitherto, the vast majority of selective drug leads that have been developed for KOR are small molecules. In this study, novel peptide probes were designed by using an endogenous dynorphin A sequence as a template for peptide stapling via late-stage cysteine functionalization. Leveraging this strategy, we developed a stable and potent KOR antagonist, CSD-CH-NH, with approximately 1000-fold improved selectivity for KOR over μ- and δ-opioid receptors. Its potent competitive KOR antagonism was verified in KOR-expressing cells, peripheral dorsal root ganglion neurons, and using the tail-flick and rotarod tests in mice. This work highlights the value of cysteine stapling to develop selective peptide probes to modulate central KOR function, as innovative peptide drug candidates for the treatment of KOR-related illnesses.
Topics: Animals; Mice; Narcotic Antagonists; Cysteine; Peptides; Dynorphins; Ganglia, Spinal; Receptors, Opioid, kappa
PubMed: 37632447
DOI: 10.1021/acs.jmedchem.3c00426