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Cuevas E, Guzman A, Burks SM, Ramirez-Lee A, Ali SF, Imam SZ. Autophagy and protein aggregation as a mechanism of dopaminergic degeneration in a primary human dopaminergic neuronal model. Toxicol Rep 2022; 9:806-813. [DOI: 10.1016/j.toxrep.2022.03.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/16/2022] [Accepted: 03/29/2022] [Indexed: 11/25/2022] Open
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Ryskamp D, Wu J, Geva M, Kusko R, Grossman I, Hayden M, Bezprozvanny I. The sigma-1 receptor mediates the beneficial effects of pridopidine in a mouse model of Huntington disease. Neurobiol Dis 2017; 97:46-59. [PMID: 27818324 PMCID: PMC5214572 DOI: 10.1016/j.nbd.2016.10.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 09/13/2016] [Accepted: 10/30/2016] [Indexed: 11/25/2022] Open
Abstract
The tri-nucleotide repeat expansion underlying Huntington disease (HD) results in corticostriatal synaptic dysfunction and subsequent neurodegeneration of striatal medium spiny neurons (MSNs). HD is a devastating autosomal dominant disease with no disease-modifying treatments. Pridopidine, a postulated "dopamine stabilizer", has been shown to improve motor symptoms in clinical trials of HD. However, the target(s) and mechanism of action of pridopidine remain to be fully elucidated. As binding studies identified sigma-1 receptor (S1R) as a high-affinity receptor for pridopidine, we evaluated the relevance of S1R as a therapeutic target of pridopidine in HD. S1R is an endoplasmic reticulum - (ER) resident transmembrane protein and is regulated by ER calcium homeostasis, which is perturbed in HD. Consistent with ER calcium dysregulation, we observed striatal upregulation of S1R in aged YAC128 transgenic HD mice and HD patients. We previously demonstrated that dendritic MSN spines are lost in aged corticostriatal co-cultures from YAC128 mice. We report here that pridopidine and the chemically similar S1R agonist 3-PPP prevent MSN spine loss in aging YAC128 co-cultures. Spine protection was blocked by neuronal deletion of S1R. Pridopidine treatment suppressed supranormal ER Ca2+ release, restored ER calcium levels and reduced excessive store-operated calcium (SOC) entry in spines, which may account for its synaptoprotective effects. Normalization of ER Ca2+ levels by pridopidine was prevented by S1R deletion. To evaluate long-term effects of pridopidine, we analyzed expression profiles of calcium signaling genes. Pridopidine elevated striatal expression of calbindin and homer1a, whereas their striatal expression was reduced in aged Q175KI and YAC128 HD mouse models compared to WT. Pridopidine and 3-PPP are proposed to prevent calcium dysregulation and synaptic loss in a YAC128 corticostriatal co-culture model of HD. The actions of pridopidine were mediated by S1R and led to normalization of ER Ca2+ release, ER Ca2+ levels and spine SOC entry in YAC128 MSNs. This is a new potential mechanism of action for pridopidine, highlighting S1R as a potential target for HD therapy. Upregulation of striatal proteins that regulate calcium, including calbindin and homer1a, upon chronic therapy with pridopidine, may further contribute to long-term beneficial effects of pridopidine in HD.
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Affiliation(s)
- Daniel Ryskamp
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Jun Wu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Michal Geva
- Teva Pharmaceutical Industries, 5 Basel St., Petach Tikva 49131, Israel.
| | | | - Iris Grossman
- Teva Pharmaceutical Industries, 5 Basel St., Petach Tikva 49131, Israel.
| | - Michael Hayden
- Teva Pharmaceutical Industries, 5 Basel St., Petach Tikva 49131, Israel.
| | - Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Tang J, Zhou H, Wang C, Fei X, Zhu L, Huang Y, He Y, Liu J, Miao X, Wu Y, Wang Y. Cell adhesion downregulates the expression of Homer1b/c and contributes to drug resistance in multiple myeloma cells. Oncol Rep 2015; 35:1875-83. [PMID: 26718835 DOI: 10.3892/or.2015.4532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/08/2015] [Indexed: 11/06/2022] Open
Abstract
Previous studies have demonstrated that Homer1b/c plays an important pro-apoptotic role through classical mitochondrial apoptotic pathway. The present study was undertaken to determine the expression and functional significance of Homer1b/c in multiple myeloma (MM). We found that Homer1b/c was lowly expressed in MM cell apoptotic model induced by doxorubicin. The positive role of Homer1b/c in cell apoptosis was further confirmed by knocking down Homer1b/c. Further study confirmed that Homer1b/c was able to affect the CAM-DR via pro-apoptotic activity regulating the ability of cell adhesion. Collectively, these data indicate that Homer1b/c may represent a good candidate for pursuing clinical trial in MM.
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Affiliation(s)
- Jie Tang
- Liyang People's Hospital, Liyang, Jiangsu 213300, P.R. China
| | - Hongxuan Zhou
- Liyang People's Hospital, Liyang, Jiangsu 213300, P.R. China
| | - Chun Wang
- Liyang People's Hospital, Liyang, Jiangsu 213300, P.R. China
| | - Xiaodong Fei
- Liyang People's Hospital, Liyang, Jiangsu 213300, P.R. China
| | - Liqun Zhu
- Liyang People's Hospital, Liyang, Jiangsu 213300, P.R. China
| | - Yuejiao Huang
- Nantong University Cancer Hospital, Nantong, Jiangsu 226001, P.R. China
| | - Yunhua He
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Jing Liu
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Xiaobing Miao
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yaxun Wu
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yuchan Wang
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, Jiangsu 226001, P.R. China
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Cui Z, Zhou L, Liu C, Zhu G, Wu X, Yan Y, Xia X, Ben Z, Song Y, Zhou Y, Zhang H, Zhang D. The role of Homer1b/c in neuronal apoptosis following LPS-induced neuroinflammation. Neurochem Res 2014; 40:204-15. [PMID: 25503822 DOI: 10.1007/s11064-014-1460-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 10/16/2014] [Accepted: 10/18/2014] [Indexed: 02/07/2023]
Abstract
Homer, also designated Vesl, is one member of the newly found postsynaptic density scaffold proteins, playing a vital role in maintaining synaptic integrity, regulating intracellular calcium mobilization, and being critical for the regulation of cellular apoptosis. However, its function in the inflamed central nervous system (CNS) is not fully elucidated. Here, we investigated the role of Homer1b/c, a long form of Homer1, in lipopolysaccharide (LPS) induced neuroinflammation in CNS. Western blot analysis indicated that LPS administration significantly increased the expression of Homer1b/c in rat brain. Moreover, double immunofluorescent staining suggested Homer1b/c was mainly distributed in the cytoplasm of neurons and had a close association with cleaved caspase-3 level in neurons in rat brain after LPS injection. In vitro studies indicated that up-regulation of Homer1b/c might be related to the subsequent apoptosis in neurons treated by conditioned media (CM), collected from LPS-stimulated mixed glial cultures (MGC). We also found down-regulation of Homer1b/c partly blocked the increase of cleaved caspase-3 and the proportion of Bax/Bcl-2 in neurons induced by MGC-CM. Taken together, these findings suggested that Homer1b/c might promote neuronal apoptosis via the Bax/Bcl-2 dependent pathway during neuroinflammation in CNS, and inhibiting Homer1b/c expression might provide a novel neuroprotective strategy against the inflammation-related neuronal apoptosis.
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Affiliation(s)
- Zhiming Cui
- Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong, 226002, Jiangsu, People's Republic of China
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Physiological Function and Characterization of TRPCs in Neurons. Cells 2014; 3:455-75. [PMID: 24852263 PMCID: PMC4092863 DOI: 10.3390/cells3020455] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/22/2014] [Accepted: 05/13/2014] [Indexed: 12/14/2022] Open
Abstract
Ca2+ entry is essential for regulating vital physiological functions in all neuronal cells. Although neurons are engaged in multiple modes of Ca2+ entry that regulates variety of neuronal functions, we will only discuss a subset of specialized Ca2+-permeable non-selective Transient Receptor Potential Canonical (TRPC) channels and summarize their physiological and pathological role in these excitable cells. Depletion of endoplasmic reticulum (ER) Ca2+ stores, due to G-protein coupled receptor activation, has been shown to activate TRPC channels in both excitable and non-excitable cells. While all seven members of TRPC channels are predominately expressed in neuronal cells, the ion channel properties, mode of activation, and their physiological responses are quite distinct. Moreover, many of these TRPC channels have also been suggested to be associated with neuronal development, proliferation and differentiation. In addition, TRPCs also regulate neurosecretion, long-term potentiation and synaptic plasticity. Similarly, perturbations in Ca2+ entry via the TRPC channels have been also suggested in a spectrum of neuropathological conditions. Hence, understanding the precise involvement of TRPCs in neuronal function and in neurodegenerative conditions would presumably unveil avenues for plausible therapeutic interventions for these devastating neuronal diseases.
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Inhibition of store-operated calcium entry attenuates MPP(+)-induced oxidative stress via preservation of mitochondrial function in PC12 cells: involvement of Homer1a. PLoS One 2013; 8:e83638. [PMID: 24358303 PMCID: PMC3866123 DOI: 10.1371/journal.pone.0083638] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 11/05/2013] [Indexed: 12/15/2022] Open
Abstract
The process of store-operated calcium entry (SOCE), whereby the release of intracellular Ca2+ from endoplasmic reticulum (ER) activates Ca2+ influx channels in the plasma membrane, has been demonstrated to impact a diverse range of cell functions. In the present study, we investigated the potential protective effect of SOCE inhibition against 1-methyl-4-phenylpyridinium (MPP+) injury by using pharmacological antagonists or specific small interfering RNA (siRNA) in PC12 cells. The results showed that both antagonists (15 μM MRS-1845 and 50 μM ML-9) and stromal interacting molecule-1 (STIM1) targeted siRNA (Si-STIM1) significantly increased cell viability, decreased apoptotic cell death and reduced intracellular reactive oxygen species (ROS) production and lipid peroxidation in MPP+ injured PC12 cells. SOCE inhibition also prevented MPP+ induced mitochondrial dysfunction and activation of mitochondrial related apoptotic factors, while had no effect on mitochondrial biogenesis. Moreover, inhibition of SOCE by antagonists and siRNA increased the expression levels of Homer1a mRNA and protein, and knockdown of Homer1a expression by specific siRNA partly reversed the protective effects induced by SOCE inhibition in PC12 cells. All these results indicated that SOCE inhibition protected PC12 cells against MPP+ insult through upregulation of Homer1a expression, and SOCE might be an ideal target for investigating therapeutic strategy against neuronal injury in PD patients.
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