1
|
Fujii C, Zorumski CF, Izumi Y. Endoplasmic reticulum stress, autophagy, neuroinflammation, and sigma 1 receptors as contributors to depression and its treatment. Neural Regen Res 2024; 19:2202-2211. [PMID: 38488553 PMCID: PMC11034583 DOI: 10.4103/1673-5374.391334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/02/2023] [Accepted: 11/24/2023] [Indexed: 04/24/2024] Open
Abstract
The etiological factors contributing to depression and other neuropsychiatric disorders are largely undefined. Endoplasmic reticulum stress pathways and autophagy are well-defined mechanisms that play critical functions in recognizing and resolving cellular stress and are possible targets for the pathophysiology and treatment of psychiatric and neurologic illnesses. An increasing number of studies indicate the involvement of endoplasmic reticulum stress and autophagy in the control of neuroinflammation, a contributing factor to multiple neuropsychiatric illnesses. Initial inflammatory triggers induce endoplasmic reticulum stress, leading to neuroinflammatory responses. Subsequently, induction of autophagy by neurosteroids and other signaling pathways that converge on autophagy induction are thought to participate in resolving neuroinflammation. The aim of this review is to summarize our current understanding of the molecular mechanisms governing the induction of endoplasmic reticulum stress, autophagy, and neuroinflammation in the central nervous system. Studies focused on innate immune factors, including neurosteroids with anti-inflammatory roles will be reviewed. In the context of depression, animal models that led to our current understanding of molecular mechanisms underlying depression will be highlighted, including the roles of sigma 1 receptors and pharmacological agents that dampen endoplasmic reticulum stress and associated neuroinflammation.
Collapse
Affiliation(s)
- Chika Fujii
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F. Zorumski
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
2
|
Izumi Y, O’Dell KA, Cashikar AG, Paul SM, Covey DF, Mennerick SJ, Zorumski CF. Neurosteroids mediate and modulate the effects of pro-inflammatory stimulation and toll-like receptors on hippocampal plasticity and learning. PLoS One 2024; 19:e0304481. [PMID: 38875235 PMCID: PMC11178232 DOI: 10.1371/journal.pone.0304481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 05/13/2024] [Indexed: 06/16/2024] Open
Abstract
Pro-inflammatory changes contribute to multiple neuropsychiatric illnesses. Understanding how these changes are involved in illnesses and identifying strategies to alter inflammatory responses offer paths to potentially novel treatments. We previously found that acute pro-inflammatory stimulation with high (μg/ml) lipopolysaccharide (LPS) for 10-15 min dampens long-term potentiation (LTP) in the hippocampus and impairs learning. Effects of LPS involved non-canonical inflammasome signaling but were independent of toll-like receptor 4 (TLR4), a known LPS receptor. Low (ng/ml) LPS also inhibits LTP when administered for 2-4 h, and here we report that this LPS exposure requires TLR4. We also found that effects of low LPS on LTP involve the oxysterol, 25-hydroxycholesterol, akin to high LPS. Effects of high LPS on LTP are blocked by inhibiting synthesis of 5α-reduced neurosteroids, indicating that neurosteroids mediate LTP inhibition. 5α-Neurosteroids also have anti-inflammatory effects, and we found that exogenous allopregnanolone (AlloP), a key 5α-reduced steroid, prevented effects of low but not high LPS on LTP. We also found that activation of TLR2, TLR3 and TLR7 inhibited LTP and that AlloP prevented the effects of TLR2 and TLR7, but not TLR3. The enantiomer of AlloP, a steroid that has anti-inflammatory actions but low activity at GABAA receptors, prevented LTP inhibition by TLR2, TLR3 and TLR7. In vivo, both AlloP enantiomers prevented LPS-induced learning defects. These studies indicate that neurosteroids play complex roles in network effects of acute neuroinflammation and have potential importance for development of AlloP analogues as therapeutic agents.
Collapse
Affiliation(s)
- Yukitoshi Izumi
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Kazuko A. O’Dell
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Anil G. Cashikar
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Steven M. Paul
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Douglas F. Covey
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
- Developmental Biology and Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States of America
- Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Steven J. Mennerick
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Charles F. Zorumski
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States of America
| |
Collapse
|
3
|
Izumi Y, Reiersen AM, Lenze EJ, Mennerick SJ, Zorumski CF. Sertraline modulates hippocampal plasticity and learning via sigma 1 receptors, cellular stress and neurosteroids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576911. [PMID: 38328198 PMCID: PMC10849579 DOI: 10.1101/2024.01.23.576911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
In addition to modulating serotonin transport, selective serotonin reuptake inhibitors (SSRIs) have multiple other effects that may contribute to clinical effects, and some of these latter actions prompt repurposing of SSRIs for non-psychiatric indications. We recently observed that the SSRIs fluvoxamine and fluoxetine prevent the acute adverse effects of pro-inflammatory stimulation on long-term potentiation (LTP) in the CA1 hippocampal region. Sertraline showed markedly different effects, acutely inhibiting LTP at a low micromolar concentration through inverse agonism of sigma 1 receptors (S1Rs). In the present studies, we pursued mechanisms contributing to sertraline modulation of LTP in rat hippocampal slices. We found that sertraline partially inhibits synaptic responses mediated by N-methyl-D-aspartate receptors (NMDARs) via effects on NMDARs that express GluN2B subunits. A selective S1R antagonist (NE-100), but not an S1R agonist (PRE-084) blocked effects on NMDARs, despite the fact that both S1R ligands were previously shown to prevent LTP inhibition. Both NE-100 and PRE-084, however, prevented adverse effects of sertraline on one-trial learning. Because of the important role that S1Rs play in modulating endoplasmic reticulum stress, we examined whether inhibitors of cellular stress alter effects of sertraline. We found that two stress inhibitors, ISRIB and quercetin, prevented LTP inhibition, as did inhibitors of the synthesis of endogenous neurosteroids, which are homeostatic regulators of cellular stress. These studies highlight complex effects of sertraline, S1Rs and neurosteroids on hippocampal function and have relevance for understanding therapeutic and adverse drug actions.
Collapse
|
4
|
Salvatore SV, Ilagan MXG, Shu H, Lambert PM, Benz A, Qian M, Covey DF, Zorumski CF, Mennerick S. Neuroactive steroid effects on autophagy in a human embryonic kidney 293 (HEK) cell model. Sci Rep 2024; 14:1042. [PMID: 38200205 PMCID: PMC10781668 DOI: 10.1038/s41598-024-51582-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/07/2024] [Indexed: 01/12/2024] Open
Abstract
Neuropsychiatric and neurodegenerative disorders are correlated with cellular stress. Macroautophagy (autophagy) may represent an important protective pathway to maintain cellular homeostasis and functionality, as it targets cytoplasmic components to lysosomes for degradation and recycling. Given recent evidence that some novel psychiatric treatments, such as the neuroactive steroid (NAS) allopregnanolone (AlloP, brexanolone), may induce autophagy, we stably transfected human embryonic kidney 293 (HEK) cells with a ratiometric fluorescent probe to assay NAS effects on autophagy. We hypothesized that NAS may modulate autophagy in part by the ability of uncharged NAS to readily permeate membranes. Microscopy revealed a weak effect of AlloP on autophagic flux compared with the positive control treatment of Torin1. In high-throughput microplate experiments, we found that autophagy induction was more robust in early passages of HEK cells. Despite limiting studies to early passages for maximum sensitivity, a range of NAS structures failed to reliably induce autophagy or interact with Torin1 or starvation effects. To probe NAS in a system where AlloP effects have been shown previously, we surveyed astrocytes and again saw minimal autophagy induction by AlloP. Combined with other published results, our results suggest that NAS may modulate autophagy in a cell-specific or context-specific manner. Although there is merit to cell lines as a screening tool, future studies may require assaying NAS in cells from brain regions involved in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Sofia V Salvatore
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Ma Xenia G Ilagan
- High-Throughput Screening Core, Center for Drug Discovery, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Hongjin Shu
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Peter M Lambert
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
- Medical Scientist Training Program, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Ann Benz
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Mingxing Qian
- Developmental Biology, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Douglas F Covey
- Developmental Biology, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Charles F Zorumski
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Steven Mennerick
- Departments of Psychiatry, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660 S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.
| |
Collapse
|
5
|
Zorumski CF, Mennerick SJ. The Taylor Family Institute at Washington University: Novel Treatments in Psychiatry. MISSOURI MEDICINE 2023; 120:299-305. [PMID: 37609459 PMCID: PMC10441266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Efforts to develop more effective treatments for psychiatric illnesses will require innovative approaches that address changes in brain networks underlying cognition, emotion and motivation, cardinal symptoms that cut across all psychiatric disorders. This effort will include new molecular entities that modulate neuronal excitability, synapses, cellular stress and inflammation. Other opportunities will come from repurposing existing treatments. This overview highlights current and future goals in treatment development in the Taylor Family Institute for Innovative Psychiatric Research at Washington University.
Collapse
Affiliation(s)
- Charles F Zorumski
- Professor, Department of Psychiatry, and the Taylor Family Institute for Innovative Psychiatric Research and Silvio O. Conte Neuroscience Center at Washington University School of Medicine, St. Louis, Missouri
| | - Steven J Mennerick
- Professor, Department of Psychiatry, and the Taylor Family Institute for Innovative Psychiatric Research and Silvio O. Conte Neuroscience Center at Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
6
|
Covey DF, Evers AS, Izumi Y, Maguire JL, Mennerick SJ, Zorumski CF. Neurosteroid enantiomers as potentially novel neurotherapeutics. Neurosci Biobehav Rev 2023; 149:105191. [PMID: 37085023 PMCID: PMC10750765 DOI: 10.1016/j.neubiorev.2023.105191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/23/2023]
Abstract
Endogenous neurosteroids and synthetic neuroactive steroids (NAS) are important targets for therapeutic development in neuropsychiatric disorders. These steroids modulate major signaling systems in the brain and intracellular processes including inflammation, cellular stress and autophagy. In this review, we describe studies performed using unnatural enantiomers of key neurosteroids, which are physiochemically identical to their natural counterparts except for rotation of polarized light. These studies led to insights in how NAS interact with receptors, ion channels and intracellular sites of action. Certain effects of NAS show high enantioselectivity, consistent with actions in chiral environments and likely direct interactions with signaling proteins. Other effects show no enantioselectivity and even reverse enantioselectivity. The spectrum of effects of NAS enantiomers raises the possibility that these agents, once considered only as tools for preclinical studies, have therapeutic potential that complements and in some cases may exceed their natural counterparts. Here we review studies of NAS enantiomers from the perspective of their potential development as novel neurotherapeutics.
Collapse
Affiliation(s)
- Douglas F Covey
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA; Anesthesiology Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Alex S Evers
- Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA; Anesthesiology Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Yukitoshi Izumi
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Jamie L Maguire
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Steven J Mennerick
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F Zorumski
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
7
|
Izumi Y, Ishikawa M, Nakazawa T, Kunikata H, Sato K, Covey DF, Zorumski CF. Neurosteroids as stress modulators and neurotherapeutics: lessons from the retina. Neural Regen Res 2023; 18:1004-1008. [PMID: 36254981 PMCID: PMC9827771 DOI: 10.4103/1673-5374.355752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Neurosteroids are rapidly emerging as important new therapies in neuropsychiatry, with one such agent, brexanolone, already approved for treatment of postpartum depression, and others on the horizon. These steroids have unique properties, including neuroprotective effects that could benefit a wide range of brain illnesses including depression, anxiety, epilepsy, and neurodegeneration. Over the past 25 years, our group has developed ex vivo rodent models to examine factors contributing to several forms of neurodegeneration in the retina. In the course of this work, we have developed a model of acute closed angle glaucoma that involves incubation of ex vivo retinas under hyperbaric conditions and results in neuronal and axonal changes that mimic glaucoma. We have used this model to determine neuroprotective mechanisms that could have therapeutic implications. In particular, we have focused on the role of both endogenous and exogenous neurosteroids in modulating the effects of acute high pressure. Endogenous allopregnanolone, a major stress-activated neurosteroid in the brain and retina, helps to prevent severe pressure-induced retinal excitotoxicity but is unable to protect against degenerative changes in ganglion cells and their axons under hyperbaric conditions. However, exogenous allopregnanolone, at a pharmacological concentration, completely preserves retinal structure and does so by combined effects on gamma-aminobutyric acid type A receptors and stimulation of the cellular process of macroautophagy. Surprisingly, the enantiomer of allopregnanolone, which is inactive at gamma-aminobutyric acid type A receptors, is equally retinoprotective and acts primarily via autophagy. Both enantiomers are also equally effective in preserving retinal structure and function in an in vivo glaucoma model. These studies in the retina have important implications for the ongoing development of allopregnanolone and other neurosteroids as therapeutics for neuropsychiatric illnesses.
Collapse
Affiliation(s)
- Yukitoshi Izumi
- Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Makoto Ishikawa
- Department of Ophthalmic Imaging and Information Analytics; Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmic Imaging and Information Analytics; Department of Ophthalmology; Department of Retinal Disease Control; Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroshi Kunikata
- Department of Ophthalmology; Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kota Sato
- Department of Ophthalmic Imaging and Information Analytics; Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Douglas F Covey
- Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research; Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F Zorumski
- Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
8
|
Ishikawa M, Izumi Y, Sato K, Sato T, Zorumski CF, Kunikata H, Nakazawa T. Glaucoma and microglia-induced neuroinflammation. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1132011. [PMID: 38983051 PMCID: PMC11182182 DOI: 10.3389/fopht.2023.1132011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 02/15/2023] [Indexed: 07/11/2024]
Abstract
Glaucoma is a multifactorial neurodegenerative disease characterized by a progressive optic neuropathy resulting in visual field defects. Elevated intraocular pressure (IOP) is the greatest risk factor for the development of glaucoma, and IOP reduction therapy is the only treatment currently available. However, there are many cases in which retinal degeneration progresses despite sufficient control of IOP. Therefore, it is important to elucidate the pathophysiology of glaucoma that is resistant to current IOP lowering therapies. Experiments using animal glaucoma models show the relationships between microglial neuroinflammatory responses and damage of retinal ganglion cells (RGCs). Inhibition of neuroinflammatory pathways associated with microglial activation appears to be neuroprotective, indicating that microglia may be an important therapeutic target for RGC protection. In this review, we will focus on microglia-induced neuroinflammation in the pathogenesis of glaucoma to offer new insights into the possibility of developing novel neuroprotective therapies targeting microglia.
Collapse
Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yukitoshi Izumi
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States
- Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States
| | - Kota Sato
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Taimu Sato
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Charles F. Zorumski
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, United States
- Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, United States
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States
| | - Hiroshi Kunikata
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
| |
Collapse
|
9
|
Izumi Y, Reiersen AM, Lenze EJ, Mennerick SJ, Zorumski CF. SSRIs differentially modulate the effects of pro-inflammatory stimulation on hippocampal plasticity and memory via sigma 1 receptors and neurosteroids. Transl Psychiatry 2023; 13:39. [PMID: 36737431 PMCID: PMC9897619 DOI: 10.1038/s41398-023-02343-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Certain selective serotonin reuptake inhibitors (SSRIs) have anti-inflammatory effects in preclinical models, and recent clinical studies suggest that fluvoxamine can prevent deterioration in patients with COVID-19, possibly through activating sigma 1 receptors (S1Rs). Here we examined potential mechanisms contributing to these effects of fluvoxamine and other SSRIs using a well-characterized model of pro-inflammatory stress in rat hippocampal slices. When hippocampal slices are exposed acutely to lipopolysaccharide (LPS), a strong pro-inflammatory stimulus, basal synaptic transmission in the CA1 region remains intact, but induction of long-term potentiation (LTP), a form of synaptic plasticity thought to contribute to learning and memory, is completely disrupted. Administration of low micromolar concentrations of fluvoxamine and fluoxetine prior to and during LPS administration overcame this LTP inhibition. Effects of fluvoxamine required both activation of S1Rs and local synthesis of 5-alpha reduced neurosteroids. In contrast, the effects of fluoxetine did not involve S1Rs but required neurosteroid production. The ability of fluvoxamine to modulate LTP and neurosteroid production was mimicked by a selective S1R agonist. Additionally, fluvoxamine and fluoxetine prevented learning impairments induced by LPS in vivo. Sertraline differed from the other SSRIs in blocking LTP in control slices likely via S1R inverse agonism. These results provide strong support for the hypothesis that S1Rs and neurosteroids play key roles in the anti-inflammatory effects of certain SSRIs and that these SSRIs could be beneficial in disorders involving inflammatory stress including psychiatric and neurodegenerative illnesses.
Collapse
Affiliation(s)
- Yukitoshi Izumi
- Department of Psychiatry & Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Angela M Reiersen
- Department of Psychiatry & Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Eric J Lenze
- Department of Psychiatry & Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Steven J Mennerick
- Department of Psychiatry & Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F Zorumski
- Department of Psychiatry & Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA. .,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
10
|
Hydroxysafflor Yellow A (HSYA) Protects Endplate Chondrocytes Against IL-1 β-Induced Injury Through Promoting Autophagy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:6326677. [PMID: 35832517 PMCID: PMC9273358 DOI: 10.1155/2022/6326677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 12/04/2022]
Abstract
Background Intervertebral disc degeneration (IDD) refers to intractable pain in patients' waist and legs, which is caused by internal structural disorder and degeneration of intervertebral. This disease severely affects the quality-of-life of people. It has been reported that hydroxysafflor yellow A (HSYA), the active ingredient in safflower extract, could inhibit IL-1β-induced apoptosis of endplate chondrocytes. However, the mechanism by which HSYA regulates the occurrence and progression of IDD remains unclear. Methods Rat endplate chondrocytes were isolated from the intervertebral disc. Next, toluidine blue staining and collagen II immunofluorescence staining were used to identify endplate chondrocytes. Then, MDC staining was used to detect the autophagy of endplate chondrocytes. In addition, Western blot was used to measure the expression of cleaved caspase 3, LC-3I/II and ATG7 in endplate chondrocytes. Results IL-1β obviously inhibited the viability and proliferation of endplate chondrocytes, while these phenomena were notably reversed by HSYA. Additionally, HSYA was able to inhibit IL-1β-induced apoptosis of endplate chondrocytes. Moreover, HSYA protected endplate chondrocytes against IL-1β-induced inflammation via inducing autophagy. Conclusion HSYA protected rat endplate chondrocytes against IL-1β-induced injury via promoting autophagy. Therefore, the present study might provide some theoretical basis for exploring novel and effective methods for patients with IDD.
Collapse
|