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Zhang S, Wang X, Chen G, Tong L, Dai T, Wang L, Zhu L, Zhang H, Du D. CircRNA Galntl6 sponges miR-335 to ameliorate stress-induced hypertension through upregulating Lig3 in rostral ventrolateral medulla. Redox Biol 2023; 64:102782. [PMID: 37315345 PMCID: PMC10363431 DOI: 10.1016/j.redox.2023.102782] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023] Open
Abstract
Rostral ventrolateral medulla (RVLM) is thought to serve as a major vasomotor center that participates in controlling the progression of stress-induced hypertension (SIH). Circular RNAs (circRNAs) perform important functions in the regulation of diverse physiological and pathological processes. However, information concerning the functions of RVLM circRNAs on SIH remains limited. RNA sequencing was performed to profile circRNA expression in RVLMs from SIH rats, which were induced by electric foot shocks and noises. The functions of circRNA Galntl6 in reducing blood pressure (BP) and its potential molecular mechanisms on SIH were investigated via various experiments, such as Western blot and intra-RVLM microinjection. A total of 12,242 circRNA transcripts were identified, among which circRNA Galntl6 was dramatically downregulated in SIH rats. The upregulation of circRNA Galntl6 in RVLM effectively decreased the BP, sympathetic outflow, and neuronal excitability in SIH rats. Mechanistically, circRNA Galntl6 directly sponged microRNA-335 (miR-335) and restrained it to reduce oxidative stress. Reintroduction of miR-335 observably reversed the circRNA Galntl6-induced attenuation of oxidative stress. Furthermore, Lig3 can be a direct target of miR-335. MiR-335 inhibition substantially increased the expression of Lig3 and suppressed oxidative stress, and these favorable effects were blocked by Lig3 knockdown. CircRNA Galntl6 is a novel factor that impedes SIH development, and the circRNA Galntl6/miR-335/Lig3 axis represents one of the possible mechanisms. These findings demonstrated circRNA Galntl6 as a possibly useful target for the prevention of SIH.
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Affiliation(s)
- Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, 310053, China
| | - Xueping Wang
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Gaojun Chen
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Lei Tong
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Tengteng Dai
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Linping Wang
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Liucun Zhu
- College of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Haili Zhang
- College of Agriculture and Bioengineering, Heze University, Heze, Shandong, 274015, China
| | - Dongshu Du
- College of Life Sciences, Shanghai University, Shanghai, 200444, China; College of Agriculture and Bioengineering, Heze University, Heze, Shandong, 274015, China; Shaoxing Institute of Shanghai University, Shaoxing, Zhejiang, 312000, China.
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Tong L, Chen G, Liu T, Wang L, Zhang H, Chen F, Zhang S, Du D. IFN-γ deficiency in the rostral ventrolateral medulla contributes to stress-induced hypertension by impairing microglial synaptic engulfment. J Hypertens 2023; 41:1323-1332. [PMID: 37260264 DOI: 10.1097/hjh.0000000000003470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Dysfunctional neurons and microglia in the rostral ventrolateral medulla (RVLM) have been implicated in the pathogenesis of stress-induced hypertension (SIH). Functional perturbation of microglial synaptic engulfment can induce aberrant brain circuit activity. IFN-γ is a pleiotropic cytokine that plays a role in regulating neuronal activity. However, existing research on the exploration of the effects of microglia on synapses in the RVLM is lacking, particularly on the function of IFN-γ in microglial synaptic engulfment involved in SIH. METHODS A SIH rat model was established by electric foot shocks combined with noise stimulation. The underlying mechanism of IFN-γ on synaptic density and microglial synaptic engulfment was investigated through in-vivo and in-vitro experiments involving gain of function, immunofluorescence, quantitative real-time PCR, western blot, and morphometric analysis. Furthermore, the function of IFN-γ in neuronal activity, renal sympathetic nerve activity (RSNA), and blood pressure (BP) regulation was determined through in-vivo and in-vitro experiments involving Ca 2+ imaging, immunofluorescence, platinum-iridium electrode recording, ELISA, the femoral artery cannulation test, and the tail-cuff method. RESULTS The BP, heart rate, RSNA, plasma norepinephrine, and the number of c-Fos-positive neurons in SIH rats increased compared with those in control rats. Pre and postsynaptic densities in the RVLM also increased in SIH rats. IFN-γ and CCL2 expression levels were significantly reduced in the RVLM of the SIH group, whose microglia also exhibited an impaired capacity for synapse engulfment. IFN-γ elevation increased CCL2 expression and microglial synaptic engulfment and decreased synaptic density in vivo and in vitro . However, CCL2 inhibition reversed these effects. Moreover, the reduction of neuronal excitability, RSNA, plasma norepinephrine, and BP by IFN-γ was abrogated through CCL2 expression. CONCLUSION IFN-γ deficiency in the RVLM impaired the microglial engulfment of synapses by inhibiting CCL2 expression and increasing synaptic density and neuronal excitability, thereby contributing to SIH progression. Targeting IFN-γ may be considered a potential strategy to combat SIH.
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Affiliation(s)
- Lei Tong
- College of Life Sciences, Shanghai University, Shanghai
| | - Gaojun Chen
- College of Life Sciences, Shanghai University, Shanghai
| | - Tianfeng Liu
- College of Life Sciences, Shanghai University, Shanghai
| | - Linping Wang
- College of Life Sciences, Shanghai University, Shanghai
| | - Haili Zhang
- College of Agriculture and Bioengineering, Heze University, Heze
| | - Fuxue Chen
- College of Life Sciences, Shanghai University, Shanghai
| | - Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou
| | - Dongshu Du
- College of Life Sciences, Shanghai University, Shanghai
- College of Agriculture and Bioengineering, Heze University, Heze
- Shaoxing Institute of Shanghai University, Shaoxing, China
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Wang L, Liu T, Wang X, Tong L, Chen G, Zhou S, Zhang H, Liu H, Lu W, Wang G, Zhang S, Du D. Microglia-derived TNF-α contributes to RVLM neuronal mitochondrial dysfunction via blocking the AMPK-Sirt3 pathway in stress-induced hypertension. J Neuroinflammation 2023; 20:137. [PMID: 37264405 DOI: 10.1186/s12974-023-02818-6] [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: 04/12/2023] [Accepted: 05/26/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Neuroinflammation in the rostral ventrolateral medulla (RVLM) has been associated with the pathogenesis of stress-induced hypertension (SIH). Neuronal mitochondrial dysfunction is involved in many pathological and physiological processes. However, the impact of neuroinflammation on neuronal mitochondrial homeostasis and the involved signaling pathway in the RVLM during SIH are largely unknown. METHODS The morphology and phenotype of microglia and the neuronal mitochondrial injury in vivo were analyzed by immunofluorescence, Western blot, RT-qPCR, transmission electron microscopy, and kit detection. The underlying mechanisms of microglia-derived tumor necrosis factor-α (TNF-α) on neuronal mitochondrial function were investigated through in vitro and in vivo experiments such as immunofluorescence and Western blot. The effect of TNF-α on blood pressure (BP) regulation was determined in vivo via intra-RVLM microinjection of TNF-α receptor antagonist R7050. RESULTS The results demonstrated that BP, heart rate (HR), renal sympathetic nerve activity (RSNA), plasma norepinephrine (NE), and electroencephalogram (EEG) power increased in SIH rats. Furthermore, the branching complexity of microglia in the RVLM of SIH rats decreased and polarized into M1 phenotype, accompanied by upregulation of TNF-α. Increased neuronal mitochondria injury was observed in the RVLM of SIH rats. Mechanistically, Sirtuin 3 (Sirt3) and p-AMPK expression were markedly downregulated in both SIH rats and TNF-α-treated N2a cells. AMPK activator A769662 upregulated AMPK-Sirt3 signaling pathway and consequently reversed TNF-α-induced mitochondrial dysfunction. Microinjection of TNF-α receptor antagonist R7050 into the RVLM of SIH rats significantly inhibited the biological activities of TNF-α, increased p-AMPK and Sirt3 levels, and alleviated neuronal mitochondrial injury, thereby reducing c-FOS expression, RSNA, plasma NE, and BP. CONCLUSIONS This study revealed that microglia-derived TNF-α in the RVLM impairs neuronal mitochondrial function in SIH possibly through inhibiting the AMPK-Sirt3 pathway. Therefore, microglia-derived TNF-α in the RVLM may be a possible therapeutic target for the intervention of SIH.
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Affiliation(s)
- Linping Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Tianfeng Liu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Xueping Wang
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Lei Tong
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Gaojun Chen
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Shumin Zhou
- College of Life Sciences, Shanghai University, Shanghai, China
| | - Haili Zhang
- College of Agriculture and Bioengineering, Heze University, Heze, Shandong, China
| | - Haisheng Liu
- College of Agriculture and Bioengineering, Heze University, Heze, Shandong, China
| | - Wen Lu
- College of Agriculture and Bioengineering, Heze University, Heze, Shandong, China
| | - Guohua Wang
- Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226019, Jiangsu, China
| | - Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.
| | - Dongshu Du
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China.
- College of Life Sciences, Shanghai University, Shanghai, China.
- College of Agriculture and Bioengineering, Heze University, Heze, Shandong, China.
- Shaoxing Institute of Shanghai University, Shaoxing, Zhejiang, China.
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Liu T, Wang L, Chen G, Tong L, Ye X, Yang H, Liu H, Zhang H, Lu W, Zhang S, Du D. PDZD8-mediated endoplasmic reticulum-mitochondria associations regulate sympathetic drive and blood pressure through the intervention of neuronal mitochondrial homeostasis in stress-induced hypertension. Neurobiol Dis 2023:106173. [PMID: 37247681 DOI: 10.1016/j.nbd.2023.106173] [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: 04/10/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 05/31/2023] Open
Abstract
Neuronal hyperexcitation in the rostral ventrolateral medulla (RVLM) drives heightened sympathetic nerve activity and contributes to the etiology of stress-induced hypertension (SIH). Maintenance of mitochondrial functions is central to neuronal homeostasis. PDZD8, an endoplasmic reticulum (ER) transmembrane protein, tethers ER to mitochondria. However, the mechanisms of PDZD8-mediated ER-mitochondria associations regulating neuronal mitochondrial functions and thereby mediating blood pressure (BP) in the RVLM of SIH were largely unknown. SIH rats were subjected to intermittent electric foot shocks plus noise for 2 h twice daily for 15 consecutive days. The underlying mechanisms of PDZD8 were investigated through in vitro experiments by using small interfering RNA and through in vivo experiments, such as intra-RVLM microinjection and Western blot analysis. The function of PDZD8 on BP regulation in the RVLM was determined in vivo via the intra-RVLM microinjection of adeno-associated virus (AAV)2-r-Pdzd8. We found that the c-Fos-positive RVLM tyrosine hydroxylase (TH) neurons, renal sympathetic nerve activity (RSNA), plasma norepinephrine (NE) level, BP, and heart rate (HR) were elevated in SIH rats. ER-mitochondria associations in RVLM neurons were significantly reduced in SIH rats. PDZD8 was mainly expressed in RVLM neurons, and mRNA and protein levels were markedly decreased in SIH rats. In N2a cells, PDZD8 knockdown disrupted ER-mitochondria associations and mitochondrial structure, decreased mitochondrial membrane potential (MMP) and respiratory metabolism, enhanced ROS levels, and reduced catalase (CAT) activity. These effects suggested that PDZD8 dysregulation induced mitochondrial malfunction. By contrast, PDZD8 upregulation in the RVLM of SIH rats could rescue neuronal mitochondrial function, thereby suppressing c-Fos expression in TH neurons and decreasing RSNA, plasma NE, BP, and HR. Our results indicated that the dysregulation of PDZD8-mediated ER-mitochondria associations led to the loss of the activity homeostasis of RVLM neurons by disrupting mitochondrial functions, thereby participating in the regulation of SIH pathology.
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Affiliation(s)
- Tianfeng Liu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Linping Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Gaojun Chen
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Lei Tong
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Xuanxuan Ye
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Hui Yang
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Haisheng Liu
- College of Agriculture and Bioengineering, Heze University, Heze 274000, China
| | - Haili Zhang
- College of Agriculture and Bioengineering, Heze University, Heze 274000, China
| | - Wen Lu
- College of Agriculture and Bioengineering, Heze University, Heze 274000, China
| | - Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, China.
| | - Dongshu Du
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; College of Life Sciences, Shanghai University, Shanghai 200444, China; Shaoxing Institute of Shanghai University, Shaoxing, Zhejiang 312000, China; College of Agriculture and Bioengineering, Heze University, Heze 274000, China.
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5
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Zhang S, Xing M, Chen G, Tong L, Zhang H, Du D. Upregulation of miR‐335 and miR‐674‐3p in the rostral ventrolateral medulla contributes to stress‐induced hypertension. J Neurochem 2022; 161:387-404. [DOI: 10.1111/jnc.15589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences Zhejiang Chinese Medical University Hangzhou Zhejiang China
| | - Mengyu Xing
- Shanghai Key Laboratory of Bio‐Energy Crops, School of Life Sciences Shanghai University Shanghai China
- School of Life Scicences Shanghai University Shanghai China
| | - Gaojun Chen
- Shanghai Key Laboratory of Bio‐Energy Crops, School of Life Sciences Shanghai University Shanghai China
- School of Life Scicences Shanghai University Shanghai China
| | - Lei Tong
- Shanghai Key Laboratory of Bio‐Energy Crops, School of Life Sciences Shanghai University Shanghai China
- School of Life Scicences Shanghai University Shanghai China
| | - Haili Zhang
- School of Life Sciences Heze University Heze Shandong China
| | - Dongshu Du
- Shanghai Key Laboratory of Bio‐Energy Crops, School of Life Sciences Shanghai University Shanghai China
- School of Life Scicences Shanghai University Shanghai China
- Shaoxing institute of technology Zhejiang China
- School of Life Sciences Heze University Heze Shandong China
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6
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Tong L, Xing M, Wu J, Zhang S, Chu D, Zhang H, Chen F, Du D. Overexpression of NaV1.6 in the rostral ventrolateral medulla in rats mediates stress-induced hypertension via glutamate regulation. Clin Exp Hypertens 2022; 44:134-145. [PMID: 34994674 DOI: 10.1080/10641963.2021.2007942] [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: 11/03/2022]
Abstract
BACKGROUND The rostral ventrolateral medulla (RVLM) plays a key role in mediating the development of stress-induced hypertension (SIH). Furthermore, enhanced glutamate transport within glutamatergic neurons in the RVLM mediates pressor responses. Data from our previous studies suggest that the voltage-gated sodium channel NaV1.6 is overexpressed in neurons in the RVLM in SIH model rats and participates in the resulting elevation of blood pressure. However, previous studies have not investigated the relationship between NaV1.6 expression and glutamatergic neurons. METHODS Here, we constructed an SIH rat model by knocking down NaV1.6 via microinjection of clustered regularly interspaced short palindromic repeats (CRISPR) guide RNA into the RVLM. Glutamate-related markers were quantified by Western blotting and immunofluorescence, and blood pressure was measured in the rats. RESULTS Our findings showed that vesicular glutamate transporter 1 (VGluT1) protein expression in the RVLM was higher in SIH rats than in Control rats, and GAD67 protein expression in SIH rats was lower than that in Control rats. Therefore, the number of VGluT1-positive neurons increased, while the number of GAD67-labeled neurons decreased after stress. After knocking down NaV1.6 expression in the RVLM, VGluT1 expression and the number of VGluT1-positive neurons decreased relative to those in SIH rats, while GAD67 protein expression and the number of GAD67-labeled neurons increased relative to those in SIH rats. CONCLUSIONS These results indicate that overexpression of NaV1.6 in the RVLM may mediate the transport and transformation of glutamate in neurons, and NaV1.6 may participate in SIH.
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Affiliation(s)
- Lei Tong
- College of Life Science, Shanghai University, Shanghai, China
| | - Mengyu Xing
- College of Life Science, Shanghai University, Shanghai, China
| | - Jiaxiang Wu
- College of Life Science, Shanghai University, Shanghai, China
| | - Shuai Zhang
- International Cooperation Laboratory of Molecular Medicine, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Dechang Chu
- College of Agriculture and Bioengineering, Heze University, Heze, China
| | - Haili Zhang
- College of Agriculture and Bioengineering, Heze University, Heze, China
| | - Fuxue Chen
- College of Life Science, Shanghai University, Shanghai, China
| | - Dongshu Du
- College of Life Science, Shanghai University, Shanghai, China.,College of Agriculture and Bioengineering, Heze University, Heze, China
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Zybura A, Hudmon A, Cummins TR. Distinctive Properties and Powerful Neuromodulation of Na v1.6 Sodium Channels Regulates Neuronal Excitability. Cells 2021; 10:cells10071595. [PMID: 34202119 PMCID: PMC8307729 DOI: 10.3390/cells10071595] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (Navs) are critical determinants of cellular excitability. These ion channels exist as large heteromultimeric structures and their activity is tightly controlled. In neurons, the isoform Nav1.6 is highly enriched at the axon initial segment and nodes, making it critical for the initiation and propagation of neuronal impulses. Changes in Nav1.6 expression and function profoundly impact the input-output properties of neurons in normal and pathological conditions. While mutations in Nav1.6 may cause channel dysfunction, aberrant changes may also be the result of complex modes of regulation, including various protein-protein interactions and post-translational modifications, which can alter membrane excitability and neuronal firing properties. Despite decades of research, the complexities of Nav1.6 modulation in health and disease are still being determined. While some modulatory mechanisms have similar effects on other Nav isoforms, others are isoform-specific. Additionally, considerable progress has been made toward understanding how individual protein interactions and/or modifications affect Nav1.6 function. However, there is still more to be learned about how these different modes of modulation interact. Here, we examine the role of Nav1.6 in neuronal function and provide a thorough review of this channel’s complex regulatory mechanisms and how they may contribute to neuromodulation.
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Affiliation(s)
- Agnes Zybura
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Biology Department, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Andy Hudmon
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47907, USA;
| | - Theodore R. Cummins
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- Biology Department, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
- Correspondence:
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8
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Peroxisome proliferator-activated receptor-γ mediates the antihypertensive effects of acupuncture in spontaneously hypertensive rats. Neuroreport 2020; 31:952-958. [PMID: 32568773 DOI: 10.1097/wnr.0000000000001496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated a central antihypertensive effect of acupuncture in rostral ventrolateral medulla (RVLM) in spontaneously hypertensive rats (SHRs). In total, 56 rats were randomly divided into seven groups as follows: the SHR group, SHR+acupuncture (SHR+Acu) group, SHR+nonacupuncture (SHR+Non-acu) group, GW9662+acupuncture (GW9662+Acu) group, GW9662+GW1929 group, GW9662 group, and 2% DMSO group (n = 8 per group). The whole eight Wistar-Kyoto rats were assigned to the WKY group. The acupuncture treatment lasting for 14 days was performed at the Taichong acupoint (LR3) or at a nonacupoint (non-acu) once daily. The peroxisome proliferator-activated receptor (PPAR)-γ agonist GW1929 and the PPAR-γ inhibitor GW9662 were microinjected by the brain stereotactic technique. Blood pressure was measured by the tail-cuff method. Sympathetic vasomotor activity was determined by implanting in a telemetry electrocardiogram radio transmitter. The expression of PPARs in the RVLM of the rats was detected using Western blot. We demonstrated that acupuncture attenuated blood pressure, heart rate, and sympathetic vasomotor activity in SHRs. The protein expression of PPAR-γ was significantly increased in SHRs treated with acupuncture. The antihypertensive effects of acupuncture in SHRs were abrogated by microinjection bilaterally into RVLM of GW9662. Microinjection of GW1929 mimicked the antihypertensive effect of acupuncture. PPAR-γ expression was negatively correlated with blood pressure and sympathetic vasomotor activity in SHRs treated with acupuncture. These results suggested that acupuncture promoted a central antihypertensive effect by increasing the expression of PPAR-γ in RVLM of SHRs.
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Zybura AS, Baucum AJ, Rush AM, Cummins TR, Hudmon A. CaMKII enhances voltage-gated sodium channel Nav1.6 activity and neuronal excitability. J Biol Chem 2020; 295:11845-11865. [PMID: 32611770 DOI: 10.1074/jbc.ra120.014062] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/30/2020] [Indexed: 11/06/2022] Open
Abstract
Nav1.6 is the primary voltage-gated sodium channel isoform expressed in mature axon initial segments and nodes, making it critical for initiation and propagation of neuronal impulses. Thus, Nav1.6 modulation and dysfunction may have profound effects on input-output properties of neurons in normal and pathological conditions. Phosphorylation is a powerful and reversible mechanism regulating ion channel function. Because Nav1.6 and the multifunctional Ca2+/CaM-dependent protein kinase II (CaMKII) are independently linked to excitability disorders, we sought to investigate modulation of Nav1.6 function by CaMKII signaling. We show that inhibition of CaMKII, a Ser/Thr protein kinase associated with excitability, synaptic plasticity, and excitability disorders, with the CaMKII-specific peptide inhibitor CN21 reduces transient and persistent currents in Nav1.6-expressing Purkinje neurons by 87%. Using whole-cell voltage clamp of Nav1.6, we show that CaMKII inhibition in ND7/23 and HEK293 cells significantly reduces transient and persistent currents by 72% and produces a 5.8-mV depolarizing shift in the voltage dependence of activation. Immobilized peptide arrays and nanoflow LC-electrospray ionization/MS of Nav1.6 reveal potential sites of CaMKII phosphorylation, specifically Ser-561 and Ser-641/Thr-642 within the first intracellular loop of the channel. Using site-directed mutagenesis to test multiple potential sites of phosphorylation, we show that Ala substitutions of Ser-561 and Ser-641/Thr-642 recapitulate the depolarizing shift in activation and reduction in current density. Computational simulations to model effects of CaMKII inhibition on Nav1.6 function demonstrate dramatic reductions in spontaneous and evoked action potentials in a Purkinje cell model, suggesting that CaMKII modulation of Nav1.6 may be a powerful mechanism to regulate neuronal excitability.
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Affiliation(s)
- Agnes S Zybura
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Anthony J Baucum
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Biology Department, Indiana University-Purdue University Indianapolis, School of Science, Indianapolis, Indiana, USA
| | | | - Theodore R Cummins
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Biology Department, Indiana University-Purdue University Indianapolis, School of Science, Indianapolis, Indiana, USA
| | - Andy Hudmon
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA .,Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
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10
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Hu L, Zhang S, Ooi K, Wu X, Wu J, Cai J, Sun Y, Wang J, Zhu D, Chen F, Xia C. Microglia-Derived NLRP3 Activation Mediates the Pressor Effect of Prorenin in the Rostral Ventrolateral Medulla of Stress-Induced Hypertensive Rats. Neurosci Bull 2020; 36:475-492. [PMID: 32242284 PMCID: PMC7186257 DOI: 10.1007/s12264-020-00484-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 12/14/2019] [Indexed: 02/07/2023] Open
Abstract
Increased microglial activation and neuroinflammation within autonomic brain regions such as the rostral ventrolateral medulla (RVLM) have been implicated in stress-induced hypertension (SIH). Prorenin, a member of the brain renin-angiotensin system (RAS), can directly activate microglia. The present study aimed to investigate the effects of prorenin on microglial activation in the RVLM of SIH rats. Rats were subjected to intermittent electric foot-shocks plus noise, this stress was administered for 2 h twice daily for 15 consecutive days, and mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) were monitored. The results showed that MAP and RSNA were augmented, and this paralleled increased pro-inflammatory phenotype (M1) switching. Prorenin and its receptor (PRR) expression and the NLR family pyrin domain containing 3 (NLRP3) activation were increased in RVLM of SIH rats. In addition, PLX5622 (a microglial depletion agent), MCC950 (a NLRP3 inhibitor), and/or PRO20 (a (Pro)renin receptor antagonist) had antihypertensive effects in the rats. The NLRP3 expression in the RVLM was decreased in SIH rats treated with PLX5622. Mito-tracker staining showed translocation of NLRP3 from mitochondria to the cytoplasm in prorenin-stimulated microglia. Prorenin increased the ROS-triggering M1 phenotype-switching and NLRP3 activation, while MCC950 decreased the M1 polarization. In conclusion, upregulated prorenin in the RVLM may be involved in the pathogenesis of SIH, mediated by activation of the microglia-derived NLRP3 inflammasome. The link between prorenin and NLRP3 in microglia provides insights for the treatment of stress-related hypertension.
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Affiliation(s)
- Li Hu
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai Key Laboratory of Bio-Energy Crops, College of Life Science, Shanghai University, Shanghai, 200444, China
| | - Shutian Zhang
- Department of Physiology and Pathophysiology, Basic Medicine College, Fudan University, Shanghai, 200032, China
| | - Kokwin Ooi
- Department of Physiology and Pathophysiology, Basic Medicine College, Fudan University, Shanghai, 200032, China
| | - Xuehai Wu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Jiaxiang Wu
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai Key Laboratory of Bio-Energy Crops, College of Life Science, Shanghai University, Shanghai, 200444, China
| | - Jian Cai
- Department of Neurology, Renji Hospital, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Yinggang Sun
- Department of Cardiovascular Diseases, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jijiang Wang
- Department of Physiology and Pathophysiology, Basic Medicine College, Fudan University, Shanghai, 200032, China
| | - Danian Zhu
- Department of Physiology and Pathophysiology, Basic Medicine College, Fudan University, Shanghai, 200032, China
| | - Fuxue Chen
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai Key Laboratory of Bio-Energy Crops, College of Life Science, Shanghai University, Shanghai, 200444, China.
| | - Chunmei Xia
- Department of Physiology and Pathophysiology, Basic Medicine College, Fudan University, Shanghai, 200032, China.
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Nav1.6 in the vasomotor center is a promising key molecule in the pathophysiology of stress-induced hypertension. Hypertens Res 2019; 42:143-144. [DOI: 10.1038/s41440-018-0141-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/19/2018] [Accepted: 10/19/2018] [Indexed: 11/08/2022]
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