Biology subjects

Brierley, S. M.

Publications and source records attributed to Brierley, S. M..

9 recordsLinked to original sources

bioRxiv2026

A Neuroendocrine Circuit That Suppresses Excretion and Pelvic Pain During Activity

Mate-seeking during peak sexual receptivity is tightly coupled with exploratory movement, a process made more efficient by transient suppression of excretion. Here, we define a functional hypothalamic-hindbrain circuit in mice that promotes locomotion while eliminating urination and defecation for hours. Chemogenetic stimulation of excitatory estrogen-melanocortin-responsive MC4R+ neurons in the ventrolateral ventromedial hypothalamus (VMHvl) effectively silences bladder and colonic visceral reflexes, even at noxious distension pressures, underscoring the potency of this anti-excretion circuit. Pelvic sensations and excretion are restored only after ablating inhibitory GABAergic neurons in the Barringtons nucleus/locus coeruleus (BAR/LC) hindbrain region or after antagonizing endogenous endorphin signaling. Our study illustrates how a hormone-responsive brain node prioritizes movement over excretion and blunts pelvic discomfort, thereby optimizing an essential voluntary behavior for evolutionary fitness.

physiology↗

bioRxiv2025

Pro-endometriosis macrophage release of IL-33 is key for endometriosis pain and lesion formation

Endometriosis is a painful gynecological inflammatory disease affecting up to 10% of females. When released by sensory neurons, calcitonin gene-related peptide (CGRP) shapes immunity, a process known as neuroimmune communication. We previously showed that nociceptor-derived CGRP polarizes macrophages into pro-endometriosis macrophages (PEMs) that mediates endometrial epithelial (endo-epi) cell proliferation and pain. However, the key mediators involved in this PEM-induced cell proliferation were unknown. Using unbiased approaches, we discovered that nociceptor-derived CGRP induces PEMs to produce IL-33. IL-33 binding to its receptor ST2 is key for endometriotic lesion growth and pain during endometriosis in mice as anti-IL-33 antibody treatment reduced evoked and spontaneous pain as well as lesion size. Chemical or genetic ablation of nociceptors or macrophages also resulted in lower levels of lesion IL-33, demonstrating a neuroimmune-driven mechanism for IL-33 production during endometriosis. In humans, we found that IL-33 is correlated with increased number of glands and fibrosis in lesions and that IL-33 expression in macrophages is also associated with genetic risk of endometriosis. We also provided evidence that suggests a dual role for IL-33 in endometriosis, in which, it is initially required for lesion formation and later for lesion maintenance only, and associated pain. Therefore, targeting IL-33/ST2 signaling may effectively treat endometriosis pain.

neuroscience↗

bioRxiv2025

A Cellular Basis for Heightened Gut Sensitivity in Females

Visceral pain disorders, such as irritable bowel syndrome, exhibit a marked female prevalence. Enhanced signaling between enterochromaffin (EC) cells in the gut epithelium and mucosal sensory nerve fibers likely contributes to this sex bias. Here, we identify a novel estrogen-responsive paracrine pathway in which two enteroendocrine cell types, PYY-expressing L-cells and serotonergic EC cells, communicate to increase gut sensitivity in females. We demonstrate that ER estrogen signaling upregulates the bacterial metabolite SCFA receptor Olfr78 on colonic L-cells, increasing PYY release and their sensitivity to acetate. Elevated PYY acts on neighboring EC cells via NPY1R, thereby enhancing serotonin release and gut pain. We propose that hormonal fluctuations, in conjunction with internal (stress) or environmental (diet) factors, amplify this local estrogen-responsive colonic circuit, resulting in maladaptive gut sensitivity.

physiology↗

bioRxiv2025

Contribution of CaV2.2 and GIRK1/2 channels to membrane excitability of rodent and human dorsal root ganglion neurons

Chronic visceral pain is a key symptom of irritable bowel syndrome (IBS). Modulation of voltage-dependent calcium and potassium channels by G protein-coupled receptors (GPCRs) plays a key role in dampening nociceptive transmission. Baclofen and the analgesic peptide -conotoxin Vc1.1 both activate GABAB receptors (GABABR), resulting in the inhibition of CaV2.2 and CaV2.3 calcium channels to reduce colonic nociception. Recent studies have also shown that GABABR activation potentiates GIRK1/2 potassium channels in mammalian sensory afferent neurons. In this study, we investigated the expression of these ion channel targets in rodent and human dorsal root ganglion (DRG) neurons, including those innervating the colon. We also examined how CaV2.2 and GIRK channel antagonists, as well as a GIRK channel activator, affect the passive and active electrical properties of adult mouse DRG neurons. Additionally, we assessed the effects of -conotoxin Vc1.1 on neuronal excitability in the presence of the selective CaV2.2 antagonist {omega}-conotoxin CVIE and the GIRK channel activator ML297. We further evaluated the impact of the GIRK channel antagonist Tertiapin-Q on excitability in mouse colonic DRGs and colonic afferents and explored the role of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in regulating membrane excitability of colonic DRGs. Our findings demonstrate that both CaV2.2 inhibition and GIRK channel potentiation reduce excitability in mouse DRGs, likely mediating the analgesic effects of Vc1.1 and baclofen observed in vivo. However, our findings indicate that GIRK channel potentiation appears to play a limited role in modulating excitability in colon-innervating DRGs and colonic afferents. These findings suggest that neurons innervating different regions of the body employ distinct mechanisms to regulate neuronal excitability and nociceptive signaling. KEY POINTS SUMMARYO_LIGABABR1, CaV2.2, and GIRK1 are highly expressed in the thoracolumbar dorsal root ganglia (DRGs) of both mice and humans. C_LIO_LIIn mouse DRGs, CaV2.2 inhibition and GIRK channel potentiation contribute to reduced neuronal excitability. C_LIO_LIThe analgesic peptide, -conotoxin Vc1.1 reduces neuronal excitability by inhibiting CaV2.2 and potentiating GIRK channels. C_LIO_LIHowever, potentiation of GIRK channels does not significantly affect the excitability in colon-innervating DRG neurons or colonic afferents. C_LIO_LISensory neurons innervating different body regions utilize distinct mechanisms to regulate their excitability. C_LI

neuroscience↗

bioRxiv2025

Splanchnic and pelvic spinal afferent pathways relay sensory information from the mouse colorectum into distinct brainstem circuits.

This study aimed to identify where the sensory information relayed by the two spinal afferent pathways innervating the distal colon and rectum (colorectum), the splanchnic and pelvic spinal afferent pathways, integrates within the brainstem. Localised injections of transneuronal viral tracer (herpes simplex virus H129 strain expressing EGFP (H129-EGFP)) into the distal colon was used to assess the brainstem structures receiving ascending input from the colorectum. H129-EGFP+ cells were distributed in structures involved in ascending sensory relay, descending pain modulation and autonomic regulation in the medulla from 96 hours and in pontine and caudal midbrain 120 hours after inoculation. In a separate cohort of mice, in vivo noxious colorectal distension (CRD) followed by brainstem immunolabelling for phosphorylated MAP kinase ERK 1/2 (pERK) showed that many of the structures in which H129-EGFP+ labelling was observed were relevant to colorectal sensory processing. Surgical removal of dorsal root ganglia (DRG) containing cell bodies of splanchnic colorectal afferent neurons, significantly reduced CRD evoked neuronal activation within the caudal ventrolateral medulla, rostral ventromedial medulla and the lateral parabrachial nuclei. Whilst, removal of DRG containing cell bodies of pelvic colorectal afferent neurons significantly reduced CRD evoked neuronal activation within the rostral ventromedial medulla, lateral parabrachial nuclei, the locus coeruleus, Barringtons nucleus and periaqueductal gray. Collectively, this study showed that the two spinal afferent pathways innervating the colorectum differentially shape colorectal processing within the brainstem and provides new insight into their unique roles to mediating visceromotor responses and defecation associated with colorectal nociception.

neuroscience↗

bioRxiv2024

Sequence-specific targeting of intrinsically disordered protein regions

Intrinsically disordered proteins and peptides play key roles in biology, but the lack of defined structures and the high variability in sequence and conformational preferences has made targeting such systems challenging. We describe a general approach for designing proteins that bind intrinsically disordered protein regions in diverse extended conformations with side chains fitting into complementary binding pockets. We used the approach to design binders for 39 highly diverse unstructured targets and obtain designs with pM to 100 nM affinities in 34 cases, testing [~]22 designs per target (including polar targets). The designs function in cells and as detection reagents, and are specific for their intended targets in all-by-all binding experiments. Our approach is a major step towards a general solution to the intrinsically disordered protein and peptide recognition problem.

biochemistry↗

bioRxiv2022

The voltage-gated sodium channel NaV1.7 underlies endometriosis-associated chronic pelvic pain

Chronic pelvic pain (CPP) is the primary symptom of endometriosis patients, but adequate treatments are lacking. Modulation of ion channels expressed by sensory nerves innervating the viscera have shown promise for the treatment of irritable bowel syndrome and overactive bladder. However, similar therapies have not been explored for endometriosis-associated CPP. Here we examined the role of the voltage-gated sodium (NaV) channel NaV1.7 in the sensitivity of vagina-innervating sensory afferents and investigated whether NaV1.7 inhibition reduces nociceptive signals from the vagina and ameliorates endometriosis-associated CPP. The mechanical responsiveness of vagina-innervating sensory afferents was assessed with ex vivo single unit recording preparations. Pain evoked by vaginal distension (VD) was quantified by the visceromotor response (VMR) in vivo. In control mice, pharmacological activation of NaV1.7 with OD1 sensitised vagina-innervating pelvic afferents to mechanical stimuli. Using a syngeneic mouse model of endometriosis, we established that endometriosis sensitized vagina-innervating pelvic afferents to mechanical stimuli. The highly selective NaV1.7 inhibitor Tsp1a revealed that this afferent hypersensitivity occurred in a NaV1.7-dependent manner. Moreover, in vivo intra-vaginal treatment with Tsp1a reduced the exaggerated VMRs to VD that is characteristic of mice with endometriosis. Conversely, Tsp1a did not alter ex vivo afferent mechanosensitivity or in vivo VMRs to VD in Sham control mice. Collectively, these findings suggest that NaV1.7 plays a crucial role in endometriosis-induced vaginal hyperalgesia. Importantly, NaV1.7 inhibition selectively alleviated endometriosis-associated CPP without the loss of normal sensation, suggesting that selective targeting of NaV1.7 could improve the quality of life of women with endometriosis.

cell biology↗

bioRxiv2022

Gut Enterochromaffin Cells are Critical Drivers of Visceral Pain and Anxiety

Gastrointestinal (GI) discomfort is a hallmark of most gut disorders and represents a significant component of chronic visceral pain 1. For the growing population afflicted by irritable bowel syndrome (IBS), GI hypersensitivity and pain persist long after signs of tissue injury have resolved 2. IBS also exhibits a strong sex bias afflicting women three-fold more than men 1. Identifying the molecules, cells, and circuits that mediate both the acute and persistent phases of visceral pain is a critical first step in understanding how environmental and endogenous factors produce long-term changes in the nervous system or associated tissues to engender chronic pain syndromes 3,4. Enterochromaffin (EC) cells within the gut epithelium are exceedingly rare sensory neuroendocrine cells that detect and transduce noxious stimuli to nearby nerve endings via serotonin. Here, we manipulate murine EC cell activity using genetic strategies to ascertain their contributions to visceral pain. We show that acute EC cell activation is sufficient to elicit hypersensitivity to gut distension and necessary for the sensitizing actions of isovalerate, a bacterially derived short-chain fatty acid irritant associated with inflammatory GI disorders. Remarkably, prolonged EC cell activation by itself is sufficient to produce persistent visceral hypersensitivity, even in the absence of an instigating inflammatory episode. Perturbing the activity of these rare EC cells led to a marked increase in anxiety-like behaviors that normalized after blocking serotonergic signaling. Sex differences were also observed accross a range of assays indicating that females have a higher baseline visceral sensitivity. Our findings validate a critical role for EC cell-mucosal afferent signaling in acute and persistent GI pain while highlighting mechanistically defined genetic models for studying visceral hypersensitivity, sex differences, and associated behaviors.

physiology↗

bioRxiv2020

Orai1- and Orai2-, but not Orai3-mediated ICRAC is regulated by intracellular pH

Three Orai (Orai1, Orai2 and Orai3) and two STIM (STIM1 and STIM2; stromal interaction molecule) mammalian protein homologues constitute major components of the store-operated Ca2+ entry mechanism. When co-expressed with STIM1, Orai1, Orai2 and Orai3 form highly selective Ca2+ channels with properties of Ca2+ release activated Ca2+ (CRAC) channels. Despite the high level of homology between Orai proteins, CRAC channels formed by different Orai isoforms have distinctive properties, particularly with regards to Ca2+ dependent inactivation, inhibition/potentiation by 2-APB and sensitivity to reactive oxygen species. This study characterises and compares the regulation of Orai1, Orai2- and Orai3-mediated CRAC current (ICRAC) by intracellular pH. Using whole-cell patch clamping of HEK293T cells heterologously expressing Orai and STIM1 we show that ICRAC formed by each Orai homologue has a unique sensitivity to changes in intracellular pH (pHi). Orai1-mediated ICRAC exhibits a strong dependence on pHi of both current amplitude and the kinetics of Ca2+ dependent inactivation. In contrast, Orai2 amplitude, but not kinetics, depends on pHi, whereas Orai3 shows no dependence on pHi at all. Investigation of different Orai1-Orai3 chimeras suggests that pHi dependence of Orai1 resides in both, the N-terminus and intracellular loop 2, and may also involve pH-dependent interactions with STIM1.

physiology↗