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Komai M, Noda Y, Ikeda A, Kaneshiro N, Kamikubo Y, Sakurai T, Uehara T, Takasugi N. Nuclear SphK2/S1P signaling is a key regulator of ApoE production and Aβ uptake in astrocytes. J Lipid Res 2024; 65:100510. [PMID: 38280459 PMCID: PMC10907773 DOI: 10.1016/j.jlr.2024.100510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/29/2024] Open
Abstract
The link between changes in astrocyte function and the pathological progression of Alzheimer's disease (AD) has attracted considerable attention. Interestingly, activated astrocytes in AD show abnormalities in their lipid content and metabolism. In particular, the expression of apolipoprotein E (ApoE), a lipid transporter, is decreased. Because ApoE has anti-inflammatory and amyloid β (Aβ)-metabolizing effects, the nuclear receptors, retinoid X receptor (RXR) and LXR, which are involved in ApoE expression, are considered promising therapeutic targets for AD. However, the therapeutic effects of agents targeting these receptors are limited or vary considerably among groups, indicating the involvement of an unknown pathological factor that modifies astrocyte and ApoE function. Here, we focused on the signaling lipid, sphingosine-1-phosphate (S1P), which is mainly produced by sphingosine kinase 2 (SphK2) in the brain. Using astrocyte models, we found that upregulation of SphK2/S1P signaling suppressed ApoE induction by both RXR and LXR agonists. We also found that SphK2 activation reduced RXR binding to the APOE promoter region in the nucleus, suggesting the nuclear function of SphK2/S1P. Intriguingly, suppression of SphK2 activity by RNA knockdown or specific inhibitors upregulated lipidated ApoE induction. Furthermore, the induced ApoE facilitates Aβ uptake in astrocytes. Together with our previous findings that SphK2 activity is upregulated in AD brain and promotes Aβ production in neurons, these results indicate that SphK2/S1P signaling is a promising multifunctional therapeutic target for AD that can modulate astrocyte function by stabilizing the effects of RXR and LXR agonists, and simultaneously regulate neuronal pathogenesis.
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Affiliation(s)
- Masato Komai
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan; Research Fellow of Japan Society for the Promotion of Science, Chiyoda, Tokyo, Japan
| | - Yuka Noda
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan
| | - Atsuya Ikeda
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan
| | - Nanaka Kaneshiro
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan
| | - Yuji Kamikubo
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Bunkyo, Tokyo, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Bunkyo, Tokyo, Japan
| | - Takashi Uehara
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan
| | - Nobumasa Takasugi
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita, Okayama, Japan; Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Bunkyo, Tokyo, Japan.
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Mi X, Ni C, Zhao J, Amin N, Jiao D, Fang M, Ye X. P2Y12 receptor mediates apoptosis and demyelination to affect functional recovery in mice with spinal cord injury. Neurochem Int 2023; 171:105641. [PMID: 37952830 DOI: 10.1016/j.neuint.2023.105641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 09/28/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023]
Abstract
Among diseases of the central nervous system (CNS), spinal cord injury (SCI) has a high fatality rate. It has been proven that P2Y G protein-coupled purinergic receptors have a neuroprotective role in apoptosis and regeneration inside the damaged spinal cord. The P2Y12 receptor (P2Y12R) has recently been linked to peripheral neuropathy and stroke. However, the role of P2Y12R after SCI remains unclear. Our study randomly divided C57BL/6J female mice into 3 groups: Sham+DMSO, SCI+DMSO, and SCI+MRS2395. MRS2395 as a P2Y12R inhibitor was intraperitoneally injected at a dose of 1.5 mg/kg once daily for 7 days. We showed that the P2Y12R was markedly activated after injury, and it was double labeled with the microglial and neuron. Behavioral tests were employed to assess motor function recovery. By using immunofluorescence staining, the NeuN expression level was detected. The morphology of neurons was observed by hematoxylin-eosin and Nissl staining. P2Y12R, Bax, GFAP, PCNA and calbindin expression levels were detected using Western blot. Meanwhile, mitochondria and myelin sheath were observed by transmission electron microscopy (TEM). Our findings demonstrated that MRS2395 significantly enhanced motor function induced by SCI and that was used to alleviate apoptosis and astrocyte scarring. NeuN positive cells in the SCI group were lower than in the therapy group, although Bax, GFAP, PCNA and calbindin expression levels were considerably higher. Moreover, following MRS2395 therapy, the histological damage was reversed. A notable improvement in myelin sheath and mitochondrial morphology was seen in the therapy group. Together, our findings indicate that activation of P2Y12R in damaged spinal cord may be a critical event and suggest that inhibition of P2Y12R might be a feasible therapeutic strategy for treating SCI.
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Affiliation(s)
- Xiaodan Mi
- Center for Rehabilitation Medicine, Rehabilitation & Sports Medicine Research Institute of Zhejiang Province, Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, 310014, China
| | - Chengtao Ni
- Graduate School, Bengbu Medical College, Bengbu, Anhui, China
| | - Jingting Zhao
- Center for Rehabilitation Medicine, Rehabilitation & Sports Medicine Research Institute of Zhejiang Province, Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, 310014, China
| | - Nashwa Amin
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, 310014, China; Institute of System Medicine, Zhejiang University School of Medicine, Hangzhou, China; Department of Zoology, Faculty of Science, Aswan University, Egypt
| | - Dian Jiao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Marong Fang
- Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.
| | - Xiangming Ye
- Center for Rehabilitation Medicine, Rehabilitation & Sports Medicine Research Institute of Zhejiang Province, Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, 310014, China.
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