1
|
Li LH, Ling DD, Lin H, Wang ZC, Sun ZR, Zhang YQ, Yang L, Zhang J, Cao H. Ovariectomy induces hyperalgesia accompanied by upregulated estrogen receptor α and protein kinase B in the rat spinal cord. Physiol Behav 2023; 271:114342. [PMID: 37673233 DOI: 10.1016/j.physbeh.2023.114342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/20/2023] [Accepted: 09/03/2023] [Indexed: 09/08/2023]
Abstract
Hormone supplementation is one of the common therapies for menopause-related disorders. Among different tools, the ovariectomy (OVX) rodents are widely accepted as an appropriate menopausal pain model. Our previous study has showed that OVX produces a significant pain facilitation in both acute pain and tonic pain, however, the underlying mechanisms remain unclear. In this study, we examined the effects of OVX treatment and estradiol (E2) supplementation on formalin-induced nociceptive responses, and explored the associated spinal mechanisms. Female Sprague-Dawley rats underwent bilateral OVX, and E2 supplementation was given subcutaneously from the 5th week after surgery (30 μg/day for 7 days). Our results showed that formalin-induced nociceptive behaviors did not differ between diestrus and proestrus stages of the estrous in intact rats. However, OVX exacerbated formalin-evoked inflammatory pain, especially in the late phase at 4-5 weeks but not 2 weeks post-surgery. E2 supplementation significantly reversed the OVX-triggered hyperalgesia. Double immunofluorescence staining revealed that both ERα and ERβ in the spinal dorsal horn were co-labeled with the neuronal markers, but not with markers of astrocytes or microglia. The spinal ERα (but not ERβ) expression significantly increased in the OVX group, which was reversed by E2 supplementation. Moreover, the OVX individuals showed an increased protein kinase B (AKT) level in lumbar spinal cord, and E2 supplementation diminished the AKT expression in OVX rats. Finally, intrathecal injection Wortmannin, an inhibitor for AKT signaling, effectively reduced the nociceptive behaviors in the late phase and the number of c-fos positive cells. Together, our findings indicate that E2 supplementation alleviates the OVX-induced hyperalgesia, which might be involved in spinal ERα and AKT mechanisms.
Collapse
Affiliation(s)
- Li-Hong Li
- Department of Anesthesiology, Fudan University Shanghai Cancer Centre, Shanghai, China
| | - Dan-Dan Ling
- Department of Anesthesiology, Fudan University Shanghai Cancer Centre, Shanghai, China
| | - Hong Lin
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Zhe-Chen Wang
- Department of Psychology, School of Social Development and Public Policy, Fudan University, Shanghai 200032, China
| | - Zhi-Rong Sun
- Department of Anesthesiology, Fudan University Shanghai Cancer Centre, Shanghai, China
| | - Yu-Qiu Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Liu Yang
- Shanghai Dunlu Biomedical Technology Co. Ltd. Shanghai 201611, China
| | - Jun Zhang
- Department of Anesthesiology, Fudan University Shanghai Cancer Centre, Shanghai, China.
| | - Hong Cao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| |
Collapse
|
2
|
Song XX, Jin LY, Li Q, Li XF, Luo Y. Estrogen receptor β/substance P signaling in spinal cord mediates antinociceptive effect in a mouse model of discogenic low back pain. Front Cell Neurosci 2023; 16:1071012. [PMID: 36756381 PMCID: PMC9899865 DOI: 10.3389/fncel.2022.1071012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/29/2022] [Indexed: 01/24/2023] Open
Abstract
Introduction Discogenic low back pain (DLBP) is the most commonly described form of back pain. Our previous studies indicated that estrogen-dependent DLBP mechanism was mediated by estrogen receptors (ERs) in the intervertebral disc (IVD) tissue, and the IVD degeneration degree is accompanied by downregulation of ERs, particularly ERβ. However, the neuropathological mechanisms underlying ERs modulation of DLBP are still not well understood. In this study, we investigated the antinociceptive effects of selective ERβ agonists on DLBP-related behavior by regulating substance P in spinal cord and dorsal root ganglia. Methods Two weeks after ovariectomies, 18-week-old female mice were randomly separated into four groups: control group; DLBP sham surgery plus vehicle group; DLBP plus vehicle group; DLBP plus ERβ-specific agonist diarylpropionitrile (DPN) group. Behavioral data was collected including behavioral measures of axial back pain (grip force and tail suspension tests) and radiating hypersensitivity (mechanical sensitivity and cold sensitivity test). Dual label scanning confocal immunofluorescence microscopy was used to observe spatial colocalization of ERβ and substance P in spinal cord. Substance P changes in spinal cord and dorsal root ganglia were measured by immunohistochemistry and real-time PCR. Results ERβ activation could improve both axial and radiating behavioral disorders of DLBP. DPN facilitated the decrease of the amount of time in immobility 1 week after agonist administration. At the time point of 3 weeks, DPN group spent significantly less time in immobility than the vehicle group. In the grip strength tests, starting from postoperative week 1-week 3, DPN injection DLBP mice showed more resistance to stretch than the vehicle injection DLBP mice. Significant differences of cold withdrawal latency time were observed between the DLBP plus DPN injection and DLBP vehicle injection groups at 2- and 3-week injection time point. DPN significantly reversed the paw withdrawal threshold of DLBP mice at the time point of 1, 2, and 3 weeks. Substance P colocalized with ERβ in spinal dorsal horn, mainly in laminae I and II, a connection site of pain transmission. Substance P levels in dorsal horn and dorsal root ganglia of DLBP group were distinctly increased compared with that of control and DLBP sham group. DPN therapy could decrease substance P content in the dorsal horn and the dorsal root ganglia of DLBP mice compared with that of vehicle-treated DLBP mice. Discussion Activation of ERβ is antinociceptive in the DLBP model by controlling substance P in spinal cord and dorsal root ganglia, which might provide a therapeutic target to manage DLBP in the clinic.
Collapse
Affiliation(s)
- Xiao-Xing Song
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin-Yu Jin
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Li
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin-Feng Li
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,*Correspondence: Xin-Feng Li,
| | - Yan Luo
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Yan Luo,
| |
Collapse
|
3
|
Unveil the pain of endometriosis: from the perspective of the nervous system. Expert Rev Mol Med 2022; 24:e36. [PMID: 36059111 DOI: 10.1017/erm.2022.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Endometriosis is a chronic inflammatory disease with pelvic pain and uncharacteristic accompanying symptoms. Endometriosis-associated pain often persists despite treatment of the disease, thus it brings a deleterious impact on their personal lives as well as imposing a substantial economic burden on them. At present, mechanisms underlie endometriosis-associated pain including inflammatory reaction, injury, aberrant blood vessels and the morphological and functional anomaly of the peripheral and central nervous systems. The nerve endings are influenced by the physical and chemical factors surrounding the lesion, via afferent nerve to the posterior root of the spinal nerve, then to the specific cerebral cortex involved in nociception. However, our understanding of the aetiology and mechanism of this complex pain process caused by endometriosis remains incomplete. Identifying the pathogenesis of endometriosis is crucial to disease management, offering proper treatment, and helping patients to seek novel targets for the maintenance and contributors of chronic pain. The main aim of this review is to focus on every possible mechanism of pain related to endometriosis in both peripheral and central nervous systems, and to present related mechanisms of action from the interaction between peripheral lesions and nerves to the changes in transmission of pain, resulting in hyperalgesia and the corresponding alterations in cerebral cortex and brain metabolism.
Collapse
|
4
|
Panevin TS, Bobkova AO, Karateev AE, Zotkin EG. Endogenous estrogen deficiency and the development of chronic musculoskeletal pain: A review. TERAPEVT ARKH 2022; 94:683-688. [DOI: 10.26442/00403660.2022.05.201490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 06/17/2022] [Indexed: 11/22/2022]
Abstract
Sexual dimorphism of chronic diseases is a phenomenon determined by differences in the hormonal status of men and women. In this regard, estrogens, which have a complex effect on the body, are of great interest. In particular, estrogens play an important role in the natural control of pain and inflammation. A decrease in estrogen levels associated with menopause or iatrogenic effects (hysterectomy, use of aromotase inhibitors), as well as mutations of genes responsible for the synthesis of structural components of membrane estrogen receptors (ESR1 and ESR2), can significantly reduce the positive effects of these hormones. Deficiency of estrogen can become one of the reasons for the development of serious pathological changes in particular, the formation of chronic pain associated with the pathology of the musculoskeletal system.
Collapse
|
5
|
Jiang Q, Li W, Zhu X, Yu L, Lu Z, Liu Y, Ma B, Cheng L. Estrogen receptor β alleviates inflammatory lesions in a rat model of inflammatory bowel disease via down-regulating P2X7R expression in macrophages. Int J Biochem Cell Biol 2021; 139:106068. [PMID: 34464722 DOI: 10.1016/j.biocel.2021.106068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 07/25/2021] [Accepted: 08/19/2021] [Indexed: 02/08/2023]
Abstract
Estrogen receptor beta (ERβ) agonists could inhibit inflammation in animal models of inflammatory bowel disease (IBD). However, the mechanism underlying such effect and the potential role of P2 × 7 receptor (P2X7R) remains unclear. In the present study, we examined whether the effect of ERβ activation in IBD rats was related to P2X7R. Overexpression of ERβ using a recombinant lentivirus in IBD rats improved the IBD-like symptoms, including weight loss, disease activity index (DAI) scores, and inflammatory responses. ERβ agonists DPN and ERB-041 attenuated P2X7R expression in macrophages from colitis rats and in a murine macrophage cell line (RAW264.7) in response to either lipopolysaccharide (LPS) or adenosine triphosphate (ATP). DPN and ERB-041 also blocked increased production of TNF-α, IL-6, and IL-1β in the rectocolon of colitis rats. The two ERβ agonists reversed LPS- and ATP-induced up-regulation of P2X7R and its downstream proteins, including NLRP3, ASC, caspase-1, and pro-IL-1β, in RAW264.7 cells. Also, in both the rectocolon of colitis rats and RAW264.7 cells, ERβ agonists reversed the up-regulation of extracellular regulated protein kinases (ERK), the Janus kinase 2 (JAK2), and signal transducer and activator of transcription 3 (STAT3), but not up-regulation of serine threonine kinase or cAMP-response element binding protein (CREB). Blockade of JAK2 or STAT3 phosphorylation significantly reduced the ability of DPN to down-regulate P2X7R expression and the ability of ERB-041 and DPN to inhibit IL-1β release from RAW264.7 cells. We found that ERβ and P2X7R co-localized in the macrophages of rat rectocolon and in RAW264.7 cells. Deletion of macrophages from colitis rats with clodronate abolished the inhibitory effect of DPN. These results suggest that ERβ plays an important anti-inflammatory role in IBD rats by down-regulating P2X7R expression and inhibiting IL-1β release from macrophages through the JAK2/STAT3 signaling pathway.
Collapse
Affiliation(s)
- Qian Jiang
- Department of Physiology, Second Military Medical University, Shanghai, 200433, People's Republic of China.
| | - Wenxin Li
- Department of Physiology, Second Military Medical University, Shanghai, 200433, People's Republic of China.
| | - Xu Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200065, People's Republic of China.
| | - Lihua Yu
- Department of Physiology, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Zhanying Lu
- Department of Physiology, Second Military Medical University, Shanghai, 200433, People's Republic of China
| | - Yuchen Liu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200065, People's Republic of China
| | - Bei Ma
- Department of Physiology, Second Military Medical University, Shanghai, 200433, People's Republic of China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200065, People's Republic of China.
| | - Liming Cheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Division of Spine Surgery, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200065, People's Republic of China.
| |
Collapse
|
6
|
Tramullas M, Collins JM, Fitzgerald P, Dinan TG, O' Mahony SM, Cryan JF. Estrous cycle and ovariectomy-induced changes in visceral pain are microbiota-dependent. iScience 2021; 24:102850. [PMID: 34381975 PMCID: PMC8333168 DOI: 10.1016/j.isci.2021.102850] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/07/2021] [Accepted: 07/09/2021] [Indexed: 12/11/2022] Open
Abstract
Visceral hypersensitivity (VH) is a hallmark of many functional gastrointestinal disorders including irritable bowel syndrome and is categorized by a dull, diffuse sensation of abdominal pain. Recently, the gut microbiota has been implicated in VH in male mice, but the effects in females have yet to be explored fully. To this end, we now show that somewhat surprisingly, female germ-free mice have similar visceral pain responses to colorectal distension (CRD) as their conventional controls. However, we show that although sensitivity to CRD is estrous cycle stage-dependent in conventional mice, it is not in germ-free mice. Further, ovariectomy (OVX) induced VH in conventional but not germ-free mice, and induced weight gain regardless of microbiota status. Finally, we show that estrogen-replacement ameliorated OVX-induced VH. Taken together, this study provides evidence for a major role of female sex hormones and the gut microbiota in sensation of visceral pain in females.
Collapse
Affiliation(s)
| | - James M Collins
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | | | - Timothy G Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Psychiatry and Behavioural Science, University College Cork, Cork, Ireland
| | - Siobhain M O' Mahony
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| |
Collapse
|
7
|
McHann MC, Blanton HL, Guindon J. Role of sex hormones in modulating breast and ovarian cancer associated pain. Mol Cell Endocrinol 2021; 533:111320. [PMID: 34033890 PMCID: PMC8263503 DOI: 10.1016/j.mce.2021.111320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 04/16/2021] [Accepted: 05/09/2021] [Indexed: 01/18/2023]
Abstract
According to the National Cancer Institute in 2020 there will be an estimated 21,750 new ovarian cancer cases and 276,480 new breast cancer cases. Both breast and ovarian cancer are hormone dependent cancers, meaning they cannot grow without the presence of hormones. The two most studied hormones in these two cancers are estrogen and progesterone, which are also involved in the modulation of pain. The incidence of pain in breast and ovarian cancer is very high. Research about mechanisms involved in modulation of pain by hormones are still being debated, as some studies find estrogen to be anti-nociceptive and others pro-nociceptive in pain studies. Moreover, analgesic treatments for breast and ovarian cancer-associated pain are limited and often ineffective. In this review, we will focus on estrogen and progesterone mechanisms of action in modulation of pain and cancer. We will also discuss new treatment options for these types of cancer and associated-pain.
Collapse
Affiliation(s)
- Melissa C McHann
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA
| | - Henry L Blanton
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA
| | - Josée Guindon
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA.
| |
Collapse
|
8
|
Arbiters of endogenous opioid analgesia: role of CNS estrogenic and glutamatergic systems. Transl Res 2021; 234:31-42. [PMID: 33567346 PMCID: PMC8217383 DOI: 10.1016/j.trsl.2021.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 11/24/2022]
Abstract
Nociception and opioid antinociception in females are pliable processes, varying qualitatively and quantitatively over the reproductive cycle. Spinal estrogenic signaling via membrane estrogen receptors (mERs), in combination with multiple other signaling molecules [spinal dynorphin, kappa-opioid receptors (KOR), glutamate and metabotropic glutamate receptor 1 (mGluR1)], appears to function as a master coordinator, parsing functionality between pronociception and antinociception. This provides a window into pharmacologically accessing intrinsic opioid analgesic/anti-allodynic systems. In diestrus, membrane estrogen receptor alpha (mERα) signals via mGluR1 to suppress spinal endomorphin 2 (EM2) analgesia. Strikingly, in the absence of exogenous opioids, interfering with this suppression in a chronic pain model elicits opioid anti-allodynia, revealing contributions of endogenous opioid(s). In proestrus, robust spinal EM2 analgesia is manifest but this requires spinal dynorphin/KOR and glutamate-activated mGluR1. Furthermore, spinal mGluR1 blockade in a proestrus chronic pain animal (eliminating spinal EM2 analgesia) exacerbates mechanical allodynia, revealing tempering by endogenous opioid(s). A complex containing mu-opioid receptor, KOR, aromatase, mGluRs, and mERα are foundational to eliciting endogenous opioid anti-allodynia. Aromatase-mERα oligomers are also plentiful, in a central nervous system region-specific fashion. These can be independently regulated and allow estrogens to act intracellularly within the same signaling complex in which they are synthesized, explaining asynchronous relationships between circulating estrogens and central nervous system estrogen functionalities. Observations with EM2 highlight the translational relevance of extensively characterizing exogenous responsiveness to endogenous opioids and the neuronal circuits that mediate them along with the multiplicity of estrogenic systems that concomitantly function in phase and out-of-phase with the reproductive cycle.
Collapse
|
9
|
Jurić M, Balog M, Ivić V, Bošković M, Benzon B, Racetin A, Vukojević K, Bočina I, Kević N, Restović I, Szűcs KF, Gáspár R, Heffer M, Vari SG, Filipović N. Increased expression of dendrin in the dorsal horn of the spinal cord during stress is regulated by sex hormones. Neuropeptides 2021; 86:102126. [PMID: 33524899 DOI: 10.1016/j.npep.2021.102126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 11/28/2022]
Abstract
Chronic stress has various effects on organisms and is sex-specific. The aim of the study was to describe the expression of synapse strengthening protein, dendrin, in the spinal cord (SC) and the dependence of its expression on chronic stress and sex hormones. Thirteen-month-old female and male rats were castrated (ovariectomy [F-OVX] or orchidectomy [M-ORX]) or sham-operated (F-SH or M-SH), respectively. At age 15 months, three 10-day-sessions of sham stress (control, C) or chronic stress (S) were conducted. Dendrin expression was present in the thoracic SC segments and the dorsal root ganglia (DRG). In the SC, dendrin expression was prominent in superficial laminae of the dorsal horn and lamina X (central canal). The M-ORX-S group had the highest dendrin expression in the dorsal horn, being significantly higher than the M-ORX-C or M-SH-S groups (P < 0.05). Dendrin expression was significantly higher in the F-SH-S group than the F-SH-C group (P < 0.05), as well as in the F-SH-S than the M-SH-S (P < 0.05). Co-localization with the α-d-galactosyl-specific isolectin B4 (IB4) in central projections of the DRG neurons in the dorsal horn of the SC was 7.43 ± 3.36%, while with the calcitonin gene-related peptide (CGRP) was 8.47 ± 4.45%. Localization of dendrin was observed in soma and nuclei of neurons in the dorsal horn. Dendrin expression in pain-processing areas of the SC, the DRG neurons and their peripheral projections suggest possible roles in pain perception and modulation. Stress-induced increase in dendrin expression and its dependence on sex hormones may partially explain sex-specific pain hypersensitivity induced by stress.
Collapse
Affiliation(s)
- Marija Jurić
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia
| | - Marta Balog
- Faculty of Medicine, Osijek Josip Juraj Strossmayer University of Osijek, Huttlerova 4, Osijek 31000, Croatia
| | - Vedrana Ivić
- Faculty of Medicine, Osijek Josip Juraj Strossmayer University of Osijek, Huttlerova 4, Osijek 31000, Croatia
| | - Maria Bošković
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia
| | - Benjamin Benzon
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia
| | - Anita Racetin
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia
| | - Katarina Vukojević
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia
| | - Ivana Bočina
- Faculty of Science, University of Split, Ruđera Boškovića 33, 21000 Split, Croatia
| | - Nives Kević
- Faculty of Science, University of Split, Ruđera Boškovića 33, 21000 Split, Croatia
| | - Ivana Restović
- Department of Teacher Education, University of Split Faculty of Humanities and Social Sciences, Poljička cesta 35, 21000 Split, Croatia
| | - Kálmán F Szűcs
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér. 12., H-6720 Szeged, Hungary
| | - Róbert Gáspár
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér. 12., H-6720 Szeged, Hungary
| | - Marija Heffer
- Faculty of Medicine, Osijek Josip Juraj Strossmayer University of Osijek, Huttlerova 4, Osijek 31000, Croatia
| | - Sandor G Vari
- International Research and Innovation in Medicine Program, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Natalija Filipović
- University of Split School of Medicine, Šoltanska 2, Split 21000, Croatia.
| |
Collapse
|
10
|
Lahat A, Falach-Malik A, Haj O, shatz Z, Ben- Horin S. Change in bowel habits during menstruation: are IBD patients different? Therap Adv Gastroenterol 2020; 13:1756284820929806. [PMID: 32577133 PMCID: PMC7290266 DOI: 10.1177/1756284820929806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/05/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND AND AIM Many female inflammatory bowel disease (IBD) patients report symptoms exacerbation before and during menses. Our aim was to characterize their symptoms and specific risk factors in comparison with healthy controls. METHODS Female IBD patients aged 18-50 years were asked to fill out a questionnaire recording their demographic and disease characteristics, menstruation history and symptoms. Disease activity was defined by Harvey-Bradshaw index (HBI) for Crohn's disease (CD) patients and modified mayo score for ulcerative colitis (UC) patients. Healthcare providers answering an internet survey assessing bowel symptoms during menstruation served as healthy controls. RESULTS A total of 139 IBD patients, of whom 100 were CD patients, filled the questionnaire. The mean age was 30.4 [±7.7 standard deviation (SD)], mean disease duration was 7.8 (±6 SD), mean HBI was 4.7 (±3.8 SD), and mean Mayo score was 2.1 (±2.5 SD). A change in bowel habits during menstruation was reported by 72% of CD patients compared with 56% of UC patients (p = 0.07). Out of 258 healthy controls, 93% reported a change in bowel habits during menstruation compared with 68% of IBD patients (p < 0.001). However, other abdominal and constitutional symptoms were significantly more prevalent among IBD patients compared with healthy controls (p < 0.01 for most parameters). Smoking status, biologic treatment, and previous abdominal operation were found to significantly aggravate symptoms during menses in IBD patients. CONCLUSION IBD patients experience various symptoms during menses significantly more commonly than healthy women. Smoking, biologic treatment, and previous abdominal operations are risk factors for higher symptomatic burden. Following future validation and research, these results can help in patients' risk stratification and possibly in risk reduction.
Collapse
Affiliation(s)
| | - Alona Falach-Malik
- Department of Gastroenterology, Sheba Medical Center, Tel Hashomer, Israel, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ola Haj
- Department of Gastroenterology, Sheba Medical Center, Tel Hashomer, Israel, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Zina shatz
- Department of Gastroenterology, Sheba Medical Center, Tel Hashomer, Israel, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shomron Ben- Horin
- Department of Gastroenterology, Sheba Medical Center, Tel Hashomer, Israel, affiliated with Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
11
|
Jiang M, Liu Y, Wu H, Ma Z, Gu X. High Estrogen Level Modifies Postoperative Hyperalgesia via GPR30 and MMP-9 in Dorsal Root Ganglia Neurons. Neurochem Res 2020; 45:1661-1673. [PMID: 32303987 DOI: 10.1007/s11064-020-03032-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/17/2020] [Accepted: 04/10/2020] [Indexed: 12/18/2022]
Abstract
The cycling of sex hormones is one of the factors affecting pain in females, and the mechanisms are not fully understood. G-protein coupled estrogen receptor 30 (GPR30) is the estrogen receptor known to be involved in mechanical hyperalgesia. Studies have demonstrated that matrix metalloproteinase-9 (MMP-9) is a critical component in peripheral/central nervous system hypersensitivity and neuroinflammation, both of which participate in hyperalgesia. Here, ovariectomized rats were treated with low or high dose estrogen replacement, and then plantar incisions were made. Subsequently, mechanical allodynia was evaluated by determining the paw withdrawal mechanical threshold before and after the incision. In rats with incisions, high estrogen levels induced postoperative hyperalgesia and upregulation of GPR30 and MMP-9 in dorsal root ganglia (DRGs). MMP-9 was expressed primarily in DRG neurons co-expressing GPR30, and led to the activation of IL-1β. After intrathecal injection of the GPR30 agonist G1, female rats with low estrogen and plantar incisions continued to exhibit significant hyperalgesia until 48 h post-incision. In high estrogen level rats with plantar incisions, intrathecal injection of GPR30 antagonist G15 significantly attenuated postoperative hyperalgesia. Intraperitoneal injection of N-acetyl-cysteine, a source of cysteine that prevents the oxidation of cysteine residues on MMP-9, significantly relieved high estrogen-induced postoperative hyperalgesia via suppression of MMP-9 and IL-1β activation in DRGs. These results demonstrate that high estrogen level in rats with incisions elicit GPR30 and MMP-9 upregulation in DRGs and subsequently activate IL-1β, leading to induced postoperative hyperalgesia.
Collapse
Affiliation(s)
- Ming Jiang
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Yue Liu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Hao Wu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Zhengliang Ma
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - Xiaoping Gu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu, China.
| |
Collapse
|
12
|
Xu S, Wang X, Zhao J, Yang S, Dong L, Qin B. GPER-mediated, oestrogen-dependent visceral hypersensitivity in stressed rats is associated with mast cell tryptase and histamine expression. Fundam Clin Pharmacol 2020; 34:433-443. [PMID: 31967341 DOI: 10.1111/fcp.12537] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 12/23/2019] [Accepted: 01/08/2020] [Indexed: 12/12/2022]
Abstract
Visceral hypersensitivity (VH) is common in irritable bowel syndrome (IBS), and female patients are more likely to seek healthcare services for IBS-related abdominal pain. Oestrogen has been reported to mediate pain modulation via its receptor, and mast cells are known to participate in the development of visceral hypersensitivity. Our previous studies showed that the G-protein-coupled oestrogen receptor (GPER, also known as GPR30) was expressed by mast cells in human colonic tissues and was associated with IBS type and severity of visceral pain. However, whether GPER is involved in oestrogen-dependent visceral hypersensitivity via mast cell degranulation is still unknown. Rats were subjected to wrap partial restraint stress to induce visceral hypersensitivity and were ovariectomized (OVX) to eliminate the effects of oestrogen on visceral hypersensitivity. OVX rats were treated with oestrogen, an oestrogen receptor α and β antagonist (ICI 182.780), a GPER antagonist (G15) or a GPER agonist (G1), to evaluate the effects of oestrogen via its receptor. The colorectal distention test was performed to assess visceral sensitivity. Immunofluorescence studies were performed to evaluate GPER and mast cell tryptase co-expression. Mast cell number with degranulation was detected by specific staining. Mast cell tryptase expression in rat colon was also investigated by Western blot and immunohistochemistry. Substance P and histamine expression were examined by ELISA. GPER was expressed by the majority of tryptase-positive mast cells in the colonic mucosa. Stressed rats showed increased visceral sensitivity, increased mast cell degranulation, mast cell tryptase expression, and increased colon histamine levels. Ovariectomy reduced stress-induced VH in female rats and decreased mast cell degranulation, mast cell tryptase expression, and histamine levels, whereas oestrogen replacement reversed these effects. In OVX rats, the GPER antagonist G15 counteracted the enhancing effects of oestrogen on stress-induced VH, mast cell degranulation, mast cell tryptase, and histamine expression, whereas VH was preserved after treatment with ICI 182.780. On the other hand, pretreatment with the selective GPER agonist G1 at doses between 1 and 20 μg/kg significantly increased VH, mast cell tryptase, and histamine expression in OVX-stressed rats, mimicking the effects of oestrogen. GPER plays a pivotal role in the regulation of mast cell degranulation, mast cell tryptase expression, and histamine levels and contributes to the development of colonic hypersensitivity in a female rat model of IBS.
Collapse
Affiliation(s)
- Shaoxian Xu
- Department of Gastroenterology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Xiaoyan Wang
- Department of Physical Examination, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Jing Zhao
- Department of Gastroenterology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Suzhen Yang
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, 730030, China
| | - Lei Dong
- Department of Gastroenterology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| | - Bin Qin
- Department of Gastroenterology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, China
| |
Collapse
|
13
|
Sun LH, Zhang WX, Xu Q, Wu H, Jiao CC, Chen XZ. Estrogen modulation of visceral pain. J Zhejiang Univ Sci B 2020; 20:628-636. [PMID: 31273960 DOI: 10.1631/jzus.b1800582] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.
Collapse
Affiliation(s)
- Li-Hong Sun
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Wen-Xin Zhang
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Qi Xu
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Hui Wu
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Cui-Cui Jiao
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Xin-Zhong Chen
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| |
Collapse
|
14
|
Zhang W, Wu H, Xu Q, Chen S, Sun L, Jiao C, Wang L, Fu F, Feng Y, Qian X, Chen X. Estrogen modulation of pain perception with a novel 17β-estradiol pretreatment regime in ovariectomized rats. Biol Sex Differ 2020; 11:2. [PMID: 31918752 PMCID: PMC6953313 DOI: 10.1186/s13293-019-0271-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/21/2019] [Indexed: 11/10/2022] Open
Abstract
Estrogen plays substantial roles in pain modulation; however, studies concerning sex hormones and nociception often yield confusing results. The discrepancy could be a result of lack of consensus to regard estrogen as a variable when working with animal models; thus, the influence of hormones’ fluctuations on nociception has continually been neglected. In the present study, we designed a novel hormone substitution model to aid us to evaluate the effects of estrogen’s long-term alterations on ovariectomy (OVX)-induced mechanical hyperalgesia and the expression of estrogen receptors(ERs). OVX rats were implanted with slow-release estrogen pellets at differently arranged time points and doses, such that a gradual elevation or decrease of serum estrogen levels following a relatively stable period of estrogen replacement was achieved in rats. Our results demonstrated that gradual estrogen depletion rather than elevation following the stable period of estrogen substitution in OVX rats alleviated OVX-induced mechanical hyperalgesia in a dose-independent manner, and the opposite estrogen increase or decrease paradigms differently regulate the expression of spinal ERs. Specifically, in rats rendered to continuously increased serum estrogen, the early phase estrogen-induced anti-nociception effect in OVX rats was eliminated, which was accompanied by an over-activation of ERα and a strong depression of ERβ, while in the OVX rats subject to gradual decrease of estrogen replacement, both ERα and ERβ increased modestly compared with the OVX group. Thus, the present study demonstrated that estrogen increase or decrease modulate nociception differently through change of spinal ERs.
Collapse
Affiliation(s)
- Wenxin Zhang
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Hui Wu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Qi Xu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Sheng Chen
- Zhejiang University School of Medicine, 866th Yuhangtang Road, Hangzhou, 310058, China
| | - Lihong Sun
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Cuicui Jiao
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Luyang Wang
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Feng Fu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Ying Feng
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Xiaowei Qian
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China
| | - Xinzhong Chen
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Xueshi Road 1, Hangzhou, 310006, China.
| |
Collapse
|
15
|
Chen C, Gong X, Yang X, Shang X, Du Q, Liao Q, Xie R, Chen Y, Xu J. The roles of estrogen and estrogen receptors in gastrointestinal disease. Oncol Lett 2019; 18:5673-5680. [PMID: 31788039 PMCID: PMC6865762 DOI: 10.3892/ol.2019.10983] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 08/13/2019] [Indexed: 12/12/2022] Open
Abstract
Estrogen is an important sex steroid hormone which serves an important role in the regulation of a number of biological functions, including regulating bone density, brain function, cholesterol mobilization, electrolyte balance, skin physiology, the cardiovascular system, the central nervous system and female reproductive organs. Estrogen exhibits various functions through binding to its specific receptors, estrogen receptor α, estrogen receptor β and G protein-coupled estrogen receptor 1. In recent years, researchers have demonstrated that estrogen and its receptors serve an important role in the gastrointestinal (GI) tract and contribute to the progression of a number of GI diseases, including gastroesophageal reflux, esophageal cancer, peptic ulcers, gastric cancer, inflammatory bowel disease, irritable bowel syndrome and colon cancer. The aim of this review is to provide an overview of estrogen and its receptors in GI disease, and highlight potential avenues for the prevention and treatment of GI diseases.
Collapse
Affiliation(s)
- Changmei Chen
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
- Department of Physiology, Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Xiang Gong
- Institute of Burns, Tongren Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Xiaoxu Yang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Xianhui Shang
- Department of Pediatric Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Qian Du
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Qiushi Liao
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Rui Xie
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Yuanshou Chen
- Department of Physiology, Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
- Professor Yuanshou Chen, Department of Physiology, Zunyi Medical University, 6 Xuefu West Road, Zunyi, Guizhou 563003, P.R. China, E-mail:
| | - Jingyu Xu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
- Department of Physiology, Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
- Correspondence to: Professor Jingyu Xu, Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Zunyi, Guizhou 563003, P.R. China, E-mail:
| |
Collapse
|
16
|
Gintzler AR, Storman EM, Liu NJ. Estrogens as arbiters of sex-specific and reproductive cycle-dependent opioid analgesic mechanisms. VITAMINS AND HORMONES 2019; 111:227-246. [PMID: 31421702 PMCID: PMC7136895 DOI: 10.1016/bs.vh.2019.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The organization of estrogenic signaling in the CNS is exceedingly complex. It is comprised of peripherally and centrally synthesized estrogens, and a plethora of types of estrogen receptor that can localize to both the nucleus and the plasma membrane. Moreover, CNS estrogen receptors can exist independent of aromatase (aka estrogen synthase) as well as oligomerize with it, along with a host of other membrane signaling proteins. This ability of CNS estrogen receptors to either to physically pair or exist separately enables locally produced estrogens to act on multiple spatial levels, with a high degree of gradated regulation and plasticity, signaling either in-phase or out-of phase with circulating estrogens. This complexity explains the numerous contradictory findings regarding sex-dependent pain processing and sexually dimorphic opioid antinociception. This review highlights the increasing awareness that estrogens are major endogenous arbiters of both opioid analgesic actions and the mechanisms used to achieve them. This behooves us to understand, and possibly intercede at, the points of intersection of estrogenic signaling and opioid functionality. Factors that integrate estrogenic actions at subcellular, synaptic, and CNS regional levels are likely to be prime drug targets for novel pharmacotherapies designed to modulate CNS estrogen-dependent opioid functionalities and possibly circumvent the current opioid epidemic.
Collapse
MESH Headings
- Analgesia
- Analgesics, Opioid/pharmacology
- Animals
- Aromatase
- Brain/physiology
- Dynorphins/physiology
- Estrogens/physiology
- Female
- Humans
- Male
- Neurosecretory Systems/physiology
- Nociception/drug effects
- Nociception/physiology
- Receptors, Estrogen/physiology
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Reproduction/physiology
- Sex Characteristics
- Signal Transduction/physiology
Collapse
Affiliation(s)
- Alan R Gintzler
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States.
| | - Emiliya M Storman
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
| | - Nai-Jiang Liu
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
| |
Collapse
|
17
|
Liu JYH, Lin G, Fang M, Rudd JA. Localization of estrogen receptor ERα, ERβ and GPR30 on myenteric neurons of the gastrointestinal tract and their role in motility. Gen Comp Endocrinol 2019; 272:63-75. [PMID: 30502347 DOI: 10.1016/j.ygcen.2018.11.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/19/2018] [Accepted: 11/27/2018] [Indexed: 12/19/2022]
Abstract
Estrogen is well known to have a modulatory role on gastrointestinal tract, particularly through its interaction with nuclear estrogen receptors (ERs), alpha and beta (ERα/β). Recent functional studies also indicate that estrogen can activate a G-protein coupled estrogen receptor, GPR30, or GPER1. The present study was designed to identify either the presence or absence of nuclear ERs and GPR30 in the myenteric plexus of the stomach, duodenum, jejunum, ileum and colon of female and male mice. Immunofluorescence staining revealed a high expression of GPR30 in the cytoplasm but not within the nucleus of enteric neurons in female and male mice. ERβ localization was similar to GPR30, where it was expressed in cytoplasm of enteric neurons, but was absent from nuclei, opening up the possibility that ERβ and GPR30 might work together to manifest estrogenic effects. Comparatively, ERα was mainly located in the nuclei of enteric neurons. ERα, ERβ and GPR30 were also expressed in the cytoplasm of glial cells in the stomach and small intestine, but levels were lower in the colon. The expression nuclear:cytoplasm ratio of ERα was higher in male than female mice, which might relate to sex-dependent translocation of ERα from cytoplasm to nucleus in response to known plasma levels of estrogen. A functional study using isolated ileal segments showed that ERα, ERβ and GPR30 are involved in the neuronal-mediated contractions in female tissues, but only ERα was involved in male tissues. This may indicate although expression level was similar between males and females, the downstream mechanisms of ERβ and GPR30 could be different between sexes. The present study provides a rationale for the action of estrogen to modulate gastrointestinal function in health and disease in different sexes.
Collapse
Affiliation(s)
- Julia Y H Liu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region.
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region.
| | - Marong Fang
- Institute of Neurosciences, Zhejiang University School of Medicine, Hangzhou, PR China.
| | - John A Rudd
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region; Brain and Mind Institute, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region.
| |
Collapse
|
18
|
Liu NJ, Storman EM, Gintzler AR. Pharmacological Modulation of Endogenous Opioid Activity to Attenuate Neuropathic Pain in Rats. THE JOURNAL OF PAIN 2018; 20:235-243. [PMID: 30366152 DOI: 10.1016/j.jpain.2018.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/12/2018] [Accepted: 10/17/2018] [Indexed: 12/23/2022]
Abstract
We showed previously that spinal metabotropic glutamate receptor 1 (mGluR1) signaling suppresses or facilitates (depending on the stage of estrous cycle) analgesic responsiveness to intrathecal endomorphin 2, a highly mu-opioid receptor-selective endogenous opioid. Spinal endomorphin 2 antinociception is suppressed during diestrus by mGluR1 when it is activated by membrane estrogen receptor alpha (mERα) and is facilitated during proestrus when mGluR1 is activated by glutamate. In the current study, we tested the hypothesis that in female rats subjected to spinal nerve ligation (SNL), the inhibition of spinal estrogen synthesis or blockade of spinal mERα/mGluR1 would be antiallodynic during diestrus, whereas during proestrus, mGluR1 blockade would worsen the mechanical allodynia. As postulated, following SNL, aromatase inhibition or mERα/mGluR1 blockade during diestrus markedly lessened the mechanical allodynia. This was observed only on the paw ipsilateral to SNL and was eliminated by naloxone, implicating endogenous opioid mediation. In contrast, during proestrus, mGluR1 blockade worsened the SNL-induced mechanical allodynia of the ipsilateral paw. Findings suggest menstrual cycle stage-specific drug targets for and the putative clinical utility of harnessing endogenous opioids for chronic pain management in women, as well as the value of, if not the necessity for, considering menstrual cycle stage in clinical trials thereof. PERSPECTIVE: Intrathecal treatments that enhance spinal endomorphin 2 analgesic responsiveness under basal conditions lessen mechanical allodynia in a chronic pain model. Findings provide a foundation for developing drugs that harness endogenous opioid antinociception for chronic pain relief, lessening the need for exogenous opioids and thus prescription opioid abuse.
Collapse
Affiliation(s)
- Nai-Jiang Liu
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York
| | - Emiliya M Storman
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York
| | - Alan R Gintzler
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York..
| |
Collapse
|
19
|
Nourbakhsh F, Atabaki R, Roohbakhsh A. The role of orphan G protein-coupled receptors in the modulation of pain: A review. Life Sci 2018; 212:59-69. [PMID: 30236869 DOI: 10.1016/j.lfs.2018.09.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/04/2018] [Accepted: 09/14/2018] [Indexed: 12/16/2022]
Abstract
G protein-coupled receptors (GPCRs) comprise a large number of receptors. Orphan GPCRs are divided into six families. These groups contain orphan receptors for which the endogenous ligands are unclear. They have various physiological effects in the body and have the potential to be used in the treatment of different diseases. Considering their important role in the central and peripheral nervous system, their role in the treatment of pain has been the subject of some recent studies. At present, there are effective therapeutics for the treatment of pain including opioid medications and non-steroidal anti-inflammatory drugs. However, the side effects of these drugs and the risks of tolerance and dependence remain a major problem. In addition, neuropathic pain is a condition that does not respond to currently available analgesic medications well. In the present review article, we aimed to review the most recent findings regarding the role of orphan GPCRs in the treatment of pain. Accordingly, based on the preclinical findings, the role of GPR3, GPR7, GPR8, GPR18, GPR30, GPR35, GPR40, GPR55, GPR74, and GPR147 in the treatment of pain was discussed. The present study highlights the role of orphan GPCRs in the modulation of pain and implies that these receptors are potential new targets for finding better and more efficient therapeutics for the management of pain particularly neuropathic pain.
Collapse
Affiliation(s)
- Fahimeh Nourbakhsh
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Rabi Atabaki
- Rayan Center for Neuroscience & Behavior, Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
20
|
Guo SW, Groothuis PG. Is it time for a paradigm shift in drug research and development in endometriosis/adenomyosis? Hum Reprod Update 2018; 24:577-598. [DOI: 10.1093/humupd/dmy020] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/21/2018] [Indexed: 12/19/2022] Open
Affiliation(s)
- Sun-Wei Guo
- Shanghai OB/GYN Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Fudan University, Shanghai, China
| | - Patrick G Groothuis
- Principal Scientist Pharmacology, Preclinical Department, Synthon Biopharmaceuticals bv, Nijmegen, The Netherlands
| |
Collapse
|
21
|
Estrogens synthesized and acting within a spinal oligomer suppress spinal endomorphin 2 antinociception: ebb and flow over the rat reproductive cycle. Pain 2018; 158:1903-1914. [PMID: 28902684 DOI: 10.1097/j.pain.0000000000000991] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The magnitude of antinociception elicited by intrathecal endomorphin 2 (EM2), an endogenous mu-opioid receptor (MOR) ligand, varies across the rat estrous cycle. We now report that phasic changes in analgesic responsiveness to spinal EM2 result from plastic interactions within a novel membrane-bound oligomer containing estrogen receptors (mERs), aromatase (aka estrogen synthase), metabotropic glutamate receptor 1 (mGluR1), and MOR. During diestrus, spinal mERs, activated by locally synthesized estrogens, act with mGluR1 to suppress spinal EM2/MOR antinociception. The emergence of robust spinal EM2 antinociception during proestrus results from the loss of mER-mGluR1 suppression, a consequence of altered interactions within the oligomer. The chemical pairing of aromatase with mERs within the oligomer containing MOR and mGluR1 allows estrogens to function as intracellular messengers whose synthesis and actions are confined to the same signaling oligomer. This form of estrogenic signaling, which we term "oligocrine," enables discrete, highly compartmentalized estrogen/mER-mGluR1 signaling to regulate MOR-mediated antinociception induced by EM2. Finally, spinal neurons were observed not only to coexpress MOR, mERα, aromatase, and mGluR1 but also be apposed by EM2 varicosities. This suggests that modulation of spinal analgesic responsiveness to exogenous EM2 likely reflects changes in its endogenous analgesic activity. Analogous suppression of spinal EM2 antinociception in women (eg, around menses, comparable with diestrus in rats) as well as the (pathological) inability to transition out of that suppressed state at other menstrual cycle stages could underlie, at least in part, the much greater prevalence and severity of chronic pain in women than men.
Collapse
|
22
|
Opposing Roles of Estradiol and Testosterone on Stress-Induced Visceral Hypersensitivity in Rats. THE JOURNAL OF PAIN 2018; 19:764-776. [PMID: 29496640 DOI: 10.1016/j.jpain.2018.02.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/30/2018] [Accepted: 02/14/2018] [Indexed: 12/19/2022]
Abstract
Chronic stress produces maladaptive pain responses, manifested as alterations in pain processing and exacerbation of chronic pain conditions including irritable bowel syndrome. Female predominance, especially during reproductive years, strongly suggests a role of gonadal hormones. However, gonadal hormone modulation of stress-induced pain hypersensitivity is not well understood. In the present study, we tested the hypothesis that estradiol is pronociceptive and testosterone is antinociceptive in a model of stress-induced visceral hypersensitivity (SIVH) in rats by recording the visceromotor response to colorectal distention after a 3-day forced swim (FS) stress paradigm. FS induced visceral hypersensitivity that persisted at least 2 weeks in female, but only 2 days in male rats. Ovariectomy blocked and orchiectomy facilitated SIVH. Furthermore, estradiol injection in intact male rats increased SIVH and testosterone in intact female rats attenuated SIVH. Western blot analyses indicated estradiol increased excitatory glutamate ionotropic receptor NMDA type subunit 1 expression and decreased inhibitory metabotropic glutamate receptor 2 expression after FS in male thoracolumbar spinal cord. In addition, the presence of estradiol during stress increased spinal brain-derived neurotrophic factor (BDNF) expression independent of sex. In contrast, testosterone blocked the stress-induced increase in BDNF expression in female rats. These data suggest that estradiol facilitates and testosterone attenuates SIVH by modulating spinal excitatory and inhibitory glutamatergic receptor expression. PERSPECTIVE SIVH is more robust in female rats. Estradiol facilitates whereas testosterone dampens the development of SIVH. This could partially explain the greater prevalence of certain chronic visceral pain conditions in women. An increase in spinal BDNF is concomitant with increased stress-induced pain. Pharmaceutical interventions targeting this molecule could provide promising alleviation of SIVH in women.
Collapse
|
23
|
Wang L, Xu H, Ge Y, Zhu H, Yu D, Yu W, Lu Z. Establishment of a murine pancreatic cancer pain model and microarray analysis of pain‑associated genes in the spinal cord dorsal horn. Mol Med Rep 2017; 16:4429-4436. [PMID: 28791352 PMCID: PMC5647002 DOI: 10.3892/mmr.2017.7173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 03/10/2017] [Indexed: 11/13/2022] Open
Abstract
There is emerging evidence on the mechanisms of pancreatic cancer pain. Following the establishment of an orthotropic transplantation model of pancreatic cancer, microarray analysis was performed to identify changes in the expression levels of pain-associated genes in the spinal cord. A mouse model of pancreatic cancer-induced pain was established by implanting SW 1990 cells into the pancreases of female BALB/c-nu mice. The survival rate and body weight were measured following orthotropic transplantation. Gross anatomical techniques and hematoxylin and eosin staining were used to analyze the pancreatic tumor tissue. Multiple behavioral tests were also performed to assess pain-associated responses. Additionally, using samples from mice with or without observable pain, microarray analysis was performed to determine the gene expression profiles in the spinal cord dorsal horn. The survival rate of mice with pancreatic cancer was high during the initial 3 weeks post-surgery, although the body weight decreased progressively. Gross anatomical techniques demonstrated that the tumor size increased significantly following the surgery, and this result was confirmed by solid tumor masses in the pancreatic tissues of the mouse model. Observable pain behavioral responses were also examined in the pancreatic cancer model by measuring the mechanical threshold of the abdominal skin, hunching behavior and visceromotor responses. The profiles of 10 pain specific-associated genes in the spinal cord dorsal horn that accurately reflect the molecular pathological progression of disease were also identified. In conclusion, the present study has developed a novel animal model of pancreatic cancer pain in BALB/c-nu mice that resembles human pancreatic cancer pain, and the expression of pain-associated genes in the spinal cord dorsal horn has been profiled. The results of the present study may further the understanding of the molecular mechanisms that mediate pancreatic cancer pain.
Collapse
Affiliation(s)
- Liqin Wang
- Department of Anesthesiology and Intensive Care Unit, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Huihong Xu
- Department of Anesthesiology and Intensive Care Unit, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Yanhu Ge
- Department of Anesthesiology, 309th hospital of CPLA, Beijing 100091, P.R. China
| | - Hai Zhu
- Department of Anesthesiology, Maternal and Child Health Hospital of Putuo, Shanghai 200061, P.R. China
| | - Dawei Yu
- Department of Anesthesiology, 101th hospital of CPLA, Wuxi, Jiangsu 214044, P.R. China
| | - Weifeng Yu
- Department of Anesthesiology and Intensive Care Unit, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| | - Zhijie Lu
- Department of Anesthesiology and Intensive Care Unit, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China
| |
Collapse
|
24
|
Zielińska M, Fichna J, Bashashati M, Habibi S, Sibaev A, Timmermans JP, Storr M. G protein-coupled estrogen receptor and estrogen receptor ligands regulate colonic motility and visceral pain. Neurogastroenterol Motil 2017; 29. [PMID: 28191706 DOI: 10.1111/nmo.13025] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/21/2016] [Accepted: 12/08/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Diarrhea-predominant irritable bowel syndrome (IBS-D) is a functional gastrointestinal (GI) disorder, which occurs more frequently in women than men. The aim of our study was to determine the role of activation of classical estrogen receptors (ER) and novel membrane receptor, G protein-coupled estrogen receptor (GPER) in human and mouse tissue and to assess the possible cross talk between these receptors in the GI tract. METHODS Immunohistochemistry was used to determine the expression of GPER in human and mouse intestines. The effect of G-1, a GPER selective agonist, and estradiol, a non-selective ER agonist, on muscle contractility was characterized in isolated preparations of the human and mouse colon. To characterize the effect of G-1 and estradiol in vivo, colonic bead expulsion test was performed. G-1 and estradiol activity on the visceral pain signaling was assessed in the mustard oil-induced abdominal pain model. KEY RESULTS GPER is expressed in the human colon and in the mouse colon and ileum. G-1 and estradiol inhibited muscle contractility in vitro in human and mouse colon. G-1 or estradiol administered intravenously at the dose of 20 mg/kg significantly prolonged the time to bead expulsion in females. Moreover, G-1 prolonged the time to bead expulsion and inhibited GI hypermotility in both genders. The injection of G-1 or estradiol resulted in a significant reduction in the number of pain-induced behaviors in mice. CONCLUSIONS AND INFERENCES GPER and ER receptors are involved in the regulation of GI motility and visceral pain. Both may thus constitute an important pharmacological target in the IBS-D therapy.
Collapse
Affiliation(s)
- M Zielińska
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - J Fichna
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - M Bashashati
- Division of Gastroenterology, Department of Internal Medicine, Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine, El Paso, TX, USA.,Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S Habibi
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - A Sibaev
- Division of Gastroenterology, Department of Medicine, Ludwig Maximilians University of Munich, Munich, Germany
| | - J-P Timmermans
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - M Storr
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Division of Gastroenterology, Department of Medicine, Ludwig Maximilians University of Munich, Munich, Germany.,Walter Brendel Center of Experimental Medicine, University of Munich, Munich, Germany
| |
Collapse
|
25
|
Danilov AB, Ilyasov RR. Sex hormones and pain. Zh Nevrol Psikhiatr Im S S Korsakova 2017. [DOI: 10.17116/jnevro201711721149-154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
26
|
Inhibitory effect of estrogen receptor beta on P2X3 receptors during inflammation in rats. Purinergic Signal 2016; 13:105-117. [PMID: 27817132 DOI: 10.1007/s11302-016-9540-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 09/21/2016] [Indexed: 10/20/2022] Open
Abstract
Estrogen receptor beta (ERβ) has been shown to play a therapeutic role in inflammatory bowel disease (IBD). However, the mechanism underlying how ERβ exerts therapeutic effects and its relationship with P2X3 receptors (P2X3R) in rats with inflammation is not known. In our study, animal behavior tests, visceromotor reflex recording, and Western blotting were used to determine whether the therapeutic effect of ERβ in rats with inflammation was related with P2X3R. In complete Freund adjuvant (CFA)-induced chronic inflammation in rats, paw withdrawal threshold was significantly decreased which were then reversed by systemic injection of ERβ agonists, DPN or ERB-041. In 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats, weight loss, higher DAI scores, increased visceromotor responses, and inflammatory responses were reversed by application of DPN or ERB-041. The higher expressions of P2X3R in dorsal root ganglia (DRG) of CFA-treated rats and those in rectocolon and DRG of TNBS-treated rats were all decreased by injection of DPN or ERB-041. DPN application also inhibited P2X3R-evoked inward currents in DRG neurons from TNBS rats. Mechanical hyperalgesia and increased P2X3 expression in ovariectomized (OVX) CFA-treated rats were reversed by estrogen replacements. Furthermore, the expressions of extracellular signal-regulated kinase (ERK) in DRG and spinal cord dorsal horn (SCDH) and c-fos in SCDH were significantly decreased after estrogen replacement compared with those of OVX rats. The ERK antagonist U0126 significantly reversed mechanical hyperalgesia in the OVX rats. These results suggest that estrogen may play an important therapeutic role in inflammation through down-regulation of P2X3R in peripheral tissues and the nervous system, probably via ERβ, suggesting a novel therapeutic strategy for clinical treatment of inflammation.
Collapse
|
27
|
Sajjad J, Felice VD, Golubeva AV, Cryan JF, O’Mahony SM. Sex-dependent activity of the spinal excitatory amino acid transporter: Role of estrous cycle. Neuroscience 2016; 333:311-9. [DOI: 10.1016/j.neuroscience.2016.07.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/28/2016] [Accepted: 07/20/2016] [Indexed: 02/07/2023]
|
28
|
Hubbard CS, Karpowicz JM, Furman AJ, da Silva JT, Seminowicz DA, Traub RJ. Estrogen-dependent visceral hypersensitivity following stress in rats: An fMRI study. Mol Pain 2016; 12:12/0/1744806916654145. [PMID: 27317579 PMCID: PMC4956385 DOI: 10.1177/1744806916654145] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/11/2016] [Indexed: 12/17/2022] Open
Abstract
We used functional MRI and a longitudinal design to investigate the brain mechanisms in a previously reported estrogen-dependent visceral hypersensitivity model. We hypothesized that noxious visceral stimulation would be associated with activation of the insula, anterior cingulate cortex, and amygdala, and that estrogen-dependent, stress-induced visceral hypersensitivity would both enhance activation of these regions and recruit activation of other brain areas mediating affect and reward processing. Ovariectomized rats were treated with estrogen (17 β-estradiol, E2) or vehicle (n = 5 per group) and scanned in a 7T MRI at three different time points: pre-stress (baseline), 2 days post-stress, and 18 days post-stress. Stress was induced via a forced-swim paradigm. In a separate group of ovariectomized rats, E2 treatment induced visceral hypersensitivity at the 2 days post-stress time point, and this hypersensitivity returned to baseline at the 18 days post-stress time point. Vehicle-treated rats show no hypersensitivity following stress. During the MRI scans, rats were exposed to noxious colorectal distention. Across groups and time points, noxious visceral stimulation led to activations in the insula, anterior cingulate, and left amygdala, parabrachial nuclei, and cerebellum. A group-by-time interaction was seen in the right amygdala, ventral striatum-pallidum, cerebellum, hippocampus, mediodorsal thalamus, and pontine nuclei. Closer inspection of the data revealed that vehicle-treated rats showed consistent activations and deactivations across time, whereas estrogen-treated animals showed minimal deactivation with noxious visceral stimulation. This unexpected finding suggests that E2 may dramatically alter visceral nociceptive processing in the brain following an acute stressor. This study is the first to examine estrogen-stress dependent interactions in response to noxious visceral stimulation using functional MRI. Future studies that include other control groups and larger sample sizes are needed to fully understand the interactions between sex hormones, stress, and noxious stimulation on brain activity.
Collapse
Affiliation(s)
- Catherine S Hubbard
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA Center for Pain and the Brain, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, USA Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Jane M Karpowicz
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Andrew J Furman
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA
| | - Joyce Teixeira da Silva
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA Department of Anaesthesia, Harvard Medical School, Boston, MA, USA Department of Anatomy, Institute of Biomedical Science-III, University of Sao Paulo, Sao Paulo, Brazil
| | - David A Seminowicz
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD, USA
| | - Richard J Traub
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD, USA
| |
Collapse
|
29
|
Abstract
PURPOSE OF REVIEW The aim is to systematically and critically review the relationship between migraine and estrogen, the predominant female sex hormone, with a focus on studies published in the last 18 months. RECENT FINDINGS Recent functional MRI (fMRI) studies of the brain support the existence of anatomical and functional differences between men and women, as well as between participants with migraine and healthy controls. In addition to the naturally occurring changes in endogenous sex hormones over the lifespan (e.g. puberty and menopause), exogenous sex hormones (e.g. hormonal contraception or hormone therapy) also may modulate migraine. Recent data support the historical view of an elevated risk of migraine with significant drops in estrogen levels. In addition, several lines of research support that reducing the magnitude of decline in estrogen concentrations prevents menstrually related migraine (MRM) and migraine aura frequency. SUMMARY Current literature has consistently demonstrated that headache, in particular migraine, is more prevalent in women as compared with men, specifically during reproductive years. Recent studies have found differences in headache characteristics, central nervous system anatomy, as well as functional activation by fMRI between the sexes in migraine patients. Although the cause underlying these differences is likely multifactorial, considerable evidence supports an important role for sex hormones. Recent studies continue to support that MRM is precipitated by drops in estrogen concentrations, and minimizing this decline may prevent these headaches. Limited data also suggest that specific regimens of combined hormone contraceptive use in MRM and migraine with aura may decrease both headache frequency and aura.
Collapse
|
30
|
Meleine M, Matricon J. Gender-related differences in irritable bowel syndrome: Potential mechanisms of sex hormones. World J Gastroenterol 2014; 20:6725-6743. [PMID: 24944465 PMCID: PMC4051914 DOI: 10.3748/wjg.v20.i22.6725] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/08/2014] [Accepted: 03/19/2014] [Indexed: 02/06/2023] Open
Abstract
According to epidemiological studies, twice as many women as men are affected by irritable bowel syndrome (IBS) in western countries, suggesting a role for sex hormones in IBS pathophysiology. Despite growing evidence about the implications of sex hormones in IBS symptom modulation, data on mechanisms by which they influence disease development are sparse. This review aims to determine the state of knowledge about the role of sex hormones in sensorimotor dysfunctions and to address the possible interplay of sex hormones with common risk factors associated with IBS. The scientific bibliography was searched using the following keywords: irritable bowel syndrome, sex, gender, ovarian hormone, estradiol, progesterone, testosterone, symptoms, pain, sensitivity, motility, permeability, stress, immune system, brain activity, spinal, supraspinal, imaging. Ovarian hormones variations along the menstrual cycle affect sensorimotor gastrointestinal function in both healthy and IBS populations. They can modulate pain processing by interacting with neuromodulator systems and the emotional system responsible for visceral pain perception. These hormones can also modulate the susceptibility to stress, which is a pivotal factor in IBS occurrence and symptom severity. For instance, estrogen-dependent hyper-responsiveness to stress can promote immune activation or impairments of gut barrier function. In conclusion, whereas it is important to keep in mind that ovarian hormones cannot be considered as a causal factor of IBS, they arguably modulate IBS onset and symptomatology. However, our understanding of the underlying mechanisms remains limited and studies assessing the link between IBS symptoms and ovarian hormone levels are needed to improve our knowledge of the disease evolution with regard to gender. Further studies assessing the role of male hormones are also needed to understand fully the role of sex hormones in IBS. Finally, investigation of brain-gut interactions is critical to decipher how stress, ovarian hormones, and female brain processing of pain can translate into gut dysfunctions.
Collapse
|
31
|
Qin B, Dong L, Guo X, Jiang J, He Y, Wang X, Li L, Zhao J. Expression of G protein-coupled estrogen receptor in irritable bowel syndrome and its clinical significance. Asian Pac J Cancer Prev 2014; 15:4733-8. [PMID: 24966932 DOI: 10.7314/apjcp.2014.15.11.4733] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Estrogen is suggested to participate in pathogenesis of irritable bowel syndrome (IBS), but expression of G protein-coupled estrogen receptor (GPER) in the colon of IBS patients has never been investigated. The aim of this study was to investigate the expression of GPER and classical estrogen receptors in the colon of IBS patients and healthy controls. METHODS Colonic biopsies were obtained by endoscopy from patients with IBS (n=46) and healthy subjects (n=13). Expression of GPER, estrogen receptor α (ERα) and estrogen receptor β (ERβ) in mast cells were measured by double-labelling immunofluorescence. Quantification of mRNA expression was performed for GPER, ERα and ERβ by real-time polymerase chain reaction. RESULTS Differential distribution of GPER, ERα and ERβ were detected in human colonic mucosa. The expression of GPER in the cytoplasm of mast cells and GPER-positive cells was significantly higher in diarrhea-predominant IBS (D-IBS) patients than that in constipation-predominant IBS (C-IBS, P<0.001) patients and healthy subjects (P=0.005). ERα and ERβ were not detected in majority of mast cells in colonic mucosa and no difference of immunostaining results for ERα and ERβ was found among these three groups. A positive correlation (r=0.451, P=0.011) between GPER-positive cell counts and abdominal pain severity was observed in D-IBS group. Relative mRNA expression of GPER in D-IBS was also higher than that in C-IBS (P=0.018) and healthy subjects (P=0.011). CONCLUSIONS The present study, for the first time, demonstrated the expression of GPER in human colonic mucosa and its correlation with abdominal pain severity.
Collapse
Affiliation(s)
- Bin Qin
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Lei Dong
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Xiaoyan Guo
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Jiong Jiang
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Yangxin He
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Xiaoyan Wang
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Lu Li
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| | - Juhui Zhao
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China
| |
Collapse
|
32
|
Nag S, Mokha SS. Activation of a Gq-coupled membrane estrogen receptor rapidly attenuates α2-adrenoceptor-induced antinociception via an ERK I/II-dependent, non-genomic mechanism in the female rat. Neuroscience 2014; 267:122-34. [PMID: 24613724 DOI: 10.1016/j.neuroscience.2014.02.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/24/2014] [Accepted: 02/24/2014] [Indexed: 01/04/2023]
Abstract
Though sex differences in pain and analgesia are known, underlying mechanisms remain elusive. This study addresses the selective contribution of membrane estrogen receptors (mERs) and mER-initiated non-genomic signaling mechanisms in our previously reported estrogen-induced attenuation of α2-adrenoceptor-mediated antinociception. By selectively targeting spinal mERs in ovariectomized female rats using β-estradiol 6-(O-carboxy-methyl)oxime bovine serum albumin (E2BSA) (membrane impermeant estradiol analog), and ERα selective agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT), ERβ selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), G-protein-coupled estrogen receptor 30 (GPR30) agonist G1 and Gq-coupled mER (Gq-mER) agonist STX, we provide strong evidence that Gq-mER activation may solely contribute to suppressing clonidine (an α2-adrenoceptor agonist)-induced antinociception, using the nociceptive tail-flick test. Increased tail-flick latencies (TFLs) by intrathecal (i.t.) clonidine were not significantly altered by i.t. PPT, DPN, or G1. In contrast, E2BSA or STX rapidly and dose-dependently attenuated clonidine-induced increase in TFL. ICI 182,780, the ER antagonist, blocked this effect. Consistent with findings with the lack of effect of ERα and ERβ agonists that modulate receptor-regulated transcription, inhibition of de novo protein synthesis using anisomycin also failed to alter the effect of E2BSA or STX, arguing against a contribution of genomic mechanisms. Immunoblotting of spinal tissue revealed that mER activation increased levels of phosphorylated extracellular signal-regulated kinase (ERK) but not of protein kinase A (PKA) or C (PKC). In vivo inhibition of ERK with U0126 blocked the effect of STX and restored clonidine antinociception. Although estrogen-induced delayed genomic mechanisms may still exist, data presented here indicate that Gq-mER may solely mediate estradiol-induced attenuation of clonidine antinociception via a rapid, reversible, and ERK-dependent, non-genomic mechanism, suggesting that Gq-mER blockade might provide improved analgesia in females.
Collapse
Affiliation(s)
- S Nag
- Department of Neuroscience and Pharmacology, Meharry Medical College, Nashville, TN 37208, United States.
| | - S S Mokha
- Department of Neuroscience and Pharmacology, Meharry Medical College, Nashville, TN 37208, United States
| |
Collapse
|
33
|
Yan XJ, Feng CC, Liu Q, Zhang LY, Dong X, Liu ZL, Cao ZJ, Mo JZ, Li Y, Fang JY, Chen SL. Vagal Afferents Mediate Antinociception of Estrogen in a Rat Model of Visceral Pain: The Involvement of Intestinal Mucosal Mast Cells and 5-Hydroxytryptamine 3 Signaling. THE JOURNAL OF PAIN 2014; 15:204-17. [DOI: 10.1016/j.jpain.2013.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 09/14/2013] [Accepted: 10/31/2013] [Indexed: 12/19/2022]
|
34
|
Cheng CL, de Groat WC. Effects of agonists for estrogen receptor α and β on ovariectomy-induced lower urinary tract dysfunction in the rat. Am J Physiol Renal Physiol 2013; 306:F181-7. [PMID: 24259512 DOI: 10.1152/ajprenal.00298.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The postmenopausal hypoestrogen status induces various lower urinary tract dysfunctions. Ovariectomized (OVX) rats exhibit voiding abnormalities, including increased postvoiding residual urine (PVR), decreased voiding efficiency (VE), and altered coordination between the detrusor and external urethral sphincter (EUS). Estradiol replacement partially normalizes voiding function in OVX rats. We determined if selective agonists for estrogen receptor (ER)α and/or ERβ can reverse lower urinary tract dysfunction in OVX rats. Cystometry and EUS electromyograms (EMGs) were recorded 6 wk after bilateral OVX in urethane-anesthetized female Sprague-Dawley rats. Animals received daily subcutaneous injections of selective ERα [propylpyrazole triol (PPT)] or ERβ [diarylpropionitrile (DPN)] agonists or vehicle for 1 wk starting on the fifth week after OVX. PPT (1 mg·kg(-1)·day(-1)) decreased PVR, improved VE, and shortened the EUS EMG active period (AP) during voiding. DPN (2 or 5 mg·kg(-1)·day(-1)) did not alter cystometric parameters or EUS EMG activity. Combined PPT + DPN treatment elicited changes in PVR, VE, and AP, similar to those induced by PPT alone, but also increased the EUS EMG silent period and volume threshold for triggering micturition. PPT increased uterine weight fourfold and decreased body weight by 11%. DPN increased uterine weight 30-45% but decreased body weight by 3-5%. Reduced voiding efficiency in OVX rats can be reversed by 1-wk drug treatment that selectively targets ERα and reduces AP during EUS bursting. Combined pharmacological activation of ERα and ERβ further enhanced EUS bursting by increasing the EUS EMG silent period and also facilitated bladder storage mechanisms by increasing the volume threshold.
Collapse
Affiliation(s)
- Chen-Li Cheng
- Div. of Urology, Dept. of Surgery, Taichung Veterans General Hospital, 1650, Taiwan Blvd. Section 4, Taichung, Taiwan 40705, Republic of China.
| | | |
Collapse
|
35
|
Traub RJ, Ji Y. Sex differences and hormonal modulation of deep tissue pain. Front Neuroendocrinol 2013; 34:350-66. [PMID: 23872333 PMCID: PMC3830473 DOI: 10.1016/j.yfrne.2013.07.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 12/11/2022]
Abstract
Women disproportionately suffer from many deep tissue pain conditions. Experimental studies show that women have lower pain thresholds, higher pain ratings and less tolerance to a range of painful stimuli. Most clinical and epidemiological reports suggest female gonadal hormones modulate pain for some, but not all, conditions. Similarly, animal studies support greater nociceptive sensitivity in females in many deep tissue pain models. Gonadal hormones modulate responses in primary afferents, dorsal horn neurons and supraspinal sites, but the direction of modulation is variable. This review will examine sex differences in deep tissue pain in humans and animals focusing on the role of gonadal hormones (mainly estradiol) as an underlying component of the modulation of pain sensitivity.
Collapse
Affiliation(s)
- Richard J Traub
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland Baltimore, 650 W. Baltimore St., 8 South, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland Baltimore, Baltimore, MD 21201, USA; Center for Pain Studies, University of Maryland Baltimore, Baltimore, MD 21201, USA.
| | | |
Collapse
|
36
|
Amandusson Å, Blomqvist A. Estrogenic influences in pain processing. Front Neuroendocrinol 2013; 34:329-49. [PMID: 23817054 DOI: 10.1016/j.yfrne.2013.06.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/19/2013] [Accepted: 06/20/2013] [Indexed: 12/24/2022]
Abstract
Gonadal hormones not only play a pivotal role in reproductive behavior and sexual differentiation, they also contribute to thermoregulation, feeding, memory, neuronal survival, and the perception of somatosensory stimuli. Numerous studies on both animals and human subjects have also demonstrated the potential effects of gonadal hormones, such as estrogens, on pain transmission. These effects most likely involve multiple neuroanatomical circuits as well as diverse neurochemical systems and they therefore need to be evaluated specifically to determine the localization and intrinsic characteristics of the neurons engaged. The aim of this review is to summarize the morphological as well as biochemical evidence in support for gonadal hormone modulation of nociceptive processing, with particular focus on estrogens and spinal cord mechanisms.
Collapse
Affiliation(s)
- Åsa Amandusson
- Department of Clinical Neurophysiology, Uppsala University, 751 85 Uppsala, Sweden.
| | | |
Collapse
|
37
|
Lu Y, Jiang Q, Yu L, Lu ZY, Meng SP, Su D, Burnstock G, Ma B. 17β-estradiol rapidly attenuates P2X3 receptor-mediated peripheral pain signal transduction via ERα and GPR30. Endocrinology 2013; 154:2421-33. [PMID: 23610132 DOI: 10.1210/en.2012-2119] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estrogen has been reported to affect pain perception, although the underlying mechanisms remain unclear. In this investigation, pain behavior testing, patch clamp recording, and immunohistochemistry were used on rats and transgenic mice to determine which estrogen receptors (ERs) and the related signaling pathway are involved in the rapid modulation of estrogen on P2X3 receptor-mediated events. The results showed that 17β-estradiol (E2) rapidly inhibited pain induced by α,β-methylene ATP (α,β-me-ATP), a P2X1 and P2X3 receptor agonist in ovariectomized rats and normal rats in diestrus. The ERα agonist 4,49,499-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) and G protein-coupled receptor 30 (GPR30) agonist G-1 mimicked the estrogen effect, whereas the ERβ agonist diarylpropionitrile (DPN) had no effect. In cultured rat dorsal root ganglion (DRG) neurons, PPT and G-1 but not DPN significantly attenuated α,β-me-ATP-mediated currents, with the dose-response curve of these currents shifted to the right. The inhibitory effect of E2 on P2X3 currents was blocked by G-15, a selective antagonist to the GPR30 estrogen receptor. E2 lacked this effect in DRG neurons from ERα-knockout mice but partly remained in those from ERβ-knockout mice. The P2X3 and GPR30 receptors were coexpressed in the rat DRG neurons. Furthermore, the ERK1/2 inhibitor U0126 reversed the inhibitory effect of E2 on α,β-me-ATP-induced pain and of PPT or G-1 on P2X3 receptor-mediated currents. The cAMP-protein kinase A (PKA) agonist forskolin, but not the PKC agonist phorbol-12-myristate-13-acetate (PMA), mimicked the estrogen-inhibitory effect on P2X3 receptor currents, which was blocked by another ERK1/2 inhibitor, PD98059. These results suggest that estrogen regulates P2X3-mediated peripheral pain by acting on ERα and GPR30 receptors expressed in primary afferent neurons, which probably involves the intracellular cAMP-PKA-ERK1/2 pathway.
Collapse
Affiliation(s)
- Yi Lu
- Department of Physiology, School of Pharmacy, Second Military Medical University, Shanghai 200433, People’s Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Sexually Dimorphic Effects of Unpredictable Early Life Adversity on Visceral Pain Behavior in a Rodent Model. THE JOURNAL OF PAIN 2013; 14:270-80. [DOI: 10.1016/j.jpain.2012.11.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/06/2012] [Accepted: 11/15/2012] [Indexed: 12/14/2022]
|
39
|
Zhang Y, Lü N, Zhao ZQ, Zhang YQ. Involvement of estrogen in rapid pain modulation in the rat spinal cord. Neurochem Res 2012; 37:2697-705. [PMID: 22903468 DOI: 10.1007/s11064-012-0859-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/17/2012] [Accepted: 07/28/2012] [Indexed: 12/16/2022]
Abstract
The pivotal role of estrogens in the pain sensitivity has been investigated in many ways. Traditionally, it is ascribed to the slow genomic changes mediated by classical nuclear estrogen receptors (ER), ERα and ERβ, depending on peripheral estrogens. Recently, it has become clear that estrogens can also signal through membrane ERs (mERs), such as G-protein-coupled ER1 (GPER1), mediating the non-genomic effects. However, the spinal specific role played by ERs and the underlying cellular mechanisms remain elusive. The present study investigated the rapid estrogenic regulation of nociception at the spinal level. Spinal administration of 17β-estradiol (E2), the most potent natural estrogen, acutely produced a remarkable mechanical allodynia and thermal hyperalgesia without significant differences among male, female and ovariectomized (Ovx) rats. E2-induced the pro-nociceptive effects were partially abrogated by ICI 182,780 (ERs antagonist), and mimicked by E2-BSA (a mER agonist). Inhibition of local E2 synthesis by 1,4,6-Androstatrien-3,17-dione (ATD, a potent irreversible aromatase inhibitor), or blockade of ERs by ICI 182,780 produced an inhibitory effect on the late phase of formalin nociceptive responses. Notably, lumbar puncture injection of G15 (a selective GPER1 antagonist) resulted in similar but more efficient inhibition of formalin nociceptive responses as compared with ICI 182,780. At the cellular level, the amplitude and decay time of spontaneous inhibitory postsynaptic currents were attenuated by short E2 or E2-BSA treatment in spinal slices. These results indicate that estrogen acutely facilitates nociceptive transmission in the spinal cord via activation of membrane-bound estrogen receptors.
Collapse
Affiliation(s)
- Yan Zhang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | | | | | | |
Collapse
|
40
|
Ji Y, Tang B, Cao DY, Wang G, Traub RJ. Sex differences in spinal processing of transient and inflammatory colorectal stimuli in the rat. Pain 2012; 153:1965-1973. [PMID: 22819535 DOI: 10.1016/j.pain.2012.06.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 06/14/2012] [Accepted: 06/19/2012] [Indexed: 02/06/2023]
Abstract
Sex differences in the spinal processing of somatic and visceral stimuli contribute to greater female sensitivity in many pain disorders. The present study examined spinal mechanisms that contribute to sex differences in visceral sensitivity. The visceromotor response to colorectal distention (CRD) was more robust in normal female rats and after intracolonic mustard oil compared with that in male rats. No sex difference was observed in the CRD-evoked response of lumbosacral (LS) and thoracolumbar (TL) colonic afferents in normal and mustard oil-treated rats, but there was a sex difference in spontaneous activity that was exacerbated by intracolonic mustard oil. The response of visceroceptive dorsal horn neurons to CRD was greater in normal female rats in the LS and TL spinal segments. The effect of intracolonic mustard oil on the CRD-evoked response of different phenotypes of visceroceptive dorsal horn neurons was dependent on sex and segment. The NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (APV) dose-dependently attenuated the visceromotor response in normal rats with greater effect in male rats. Correspondingly, there was greater cell membrane expression of the GluN1 subunit in dorsal horn extracts in female rats. After intracolonic mustard oil, there was no longer a sex difference in the effect of APV nor GluN1 expression in LS segments, but greater female expression in TL segments. These data document a sex difference in spinal processing of nociceptive visceral stimuli from the normal and inflamed colon. Differences in dorsal horn neuronal activity and NMDA receptor expression contribute to the sex differences in the visceral sensitivity observed in awake rats.
Collapse
Affiliation(s)
- Yaping Ji
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, USA Center for Pain Studies, University of Maryland, Baltimore, MD, USA Program in Neuroscience, University of Maryland, Baltimore, MD, USA
| | | | | | | | | |
Collapse
|