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Yao K, Mou Q, Lou X, Ye M, Zhao B, Hu Y, Luo J, Zhang H, Li X, Zhao Y. Microglial SIRT1 activation attenuates synapse loss in retinal inner plexiform layer via mTORC1 inhibition. J Neuroinflammation 2023; 20:202. [PMID: 37670386 PMCID: PMC10481494 DOI: 10.1186/s12974-023-02886-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/30/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND Optic nerve injury (ONI) is a key cause of irreversible blindness and triggers retinal ganglion cells (RGCs) change and synapse loss. Microglia is the resistant immune cell in brain and retina and has been demonstrated to be highly related with neuron and synapse injury. However, the function of Sirtuin 1 (SIRT1), a neuroprotective molecule, in mediating microglial activation, retinal synapse loss and subsequent retinal ganglion cells death in optic nerve injury model as well as the regulatory mechanism remain unclear. METHOD To this end, optic nerve crush (ONC) model was conducted to mimic optic nerve injury. Resveratrol and EX527, highly specific activator and inhibitor of SIRT1, respectively, were used to explore the function of SIRT1 in vivo and vitro. Cx3Cr1-CreERT2/RaptorF/F mice were used to delete Raptor for inhibiting mammalian target of rapamycin complex 1 (mTORC1) activity in microglia. HEK293 and BV2 cells were transfected with plasmids to explore the regulatory mechanism of SIRT1. RESULTS We discovered that microglial activation and synapse loss in retinal inner plexiform layer (IPL) occurred after optic nerve crush, with later-development retinal ganglion cells death. SIRT1 activation induced by resveratrol inhibited microglial activation and attenuated synapse loss and retinal ganglion cells injury. After injury, microglial phagocytosed synapse and SIRT1 inhibited this process to protect synapse and retinal ganglion cells. Moreover, SIRT1 exhibited neuron protective effects via activating tuberous sclerosis complex 2 (TSC2) through deacetylation, and enhancing the inhibition effect of tuberous sclerosis complex 2 on mammalian target of rapamycin complex 1 activity. CONCLUSION Our research provides novel insights into microglial SIRT1 in optic nerve injury and suggests a potential strategy for neuroprotective treatment of optic nerve injury disease.
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Affiliation(s)
- Ke Yao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qianxue Mou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaotong Lou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meng Ye
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Bowen Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuanyuan Hu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jing Luo
- Institute of Reproductive Health, Center for Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xing Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yin Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Hydrogen Sulfide Attenuates High-Fat Diet-Induced Obesity: Involvement of mTOR/IKK/NF-κB Signaling Pathway. Mol Neurobiol 2022; 59:6903-6917. [PMID: 36053437 DOI: 10.1007/s12035-022-03004-0] [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: 03/18/2022] [Accepted: 08/16/2022] [Indexed: 10/14/2022]
Abstract
Obesity has become a public health epidemic worldwide and is associated with many diseases with high mortality including hypertension, diabetes, and heart disease. High-fat diet (HFD)-induced energy imbalance is one of the primary causes of obesity, but the underlying mechanisms are not fully elucidated. Our study showed that HFD reduced the level of hydrogen sulfide (H2S) and its catalytic enzyme cystathionine β-synthase (CBS) in mouse hypothalamus and plasma. We found that HFD activated mTOR, IKK/NF-κB, the main pathway regulating inflammation. Activation of inflammatory pathway promoted the production of pro-inflammatory cytokines including IL-6, IL-1β, and TNF-α, which caused cell damage and loss in the hypothalamus. The disturbance of the hypothalamic neuron circuits resulted in body weight gain in HFD-induced mice. Importantly, we also showed that restoration of H2S level with NaHS or activation of CBS with SAMe attenuated HFD-induced activation of mTOR, IKK/NF-κB signaling, which reduced the inflammation and the neuronal cell loss in the hypothalamus, and also inhibited body weight gain in mice. The same effects were obtained by inhibiting mTOR or NF-κB, which suggested that mTOR and NF-κB were the critical molecular factors involved in hypothalamic inflammation. Taken together, this study identified that HFD-induced hypothalamus inflammation plays a critical role in the development of obesity. Moreover, the inhibition of hypothalamic inflammation by regaining H2S level could be a potential therapeutic to prevent the development of obesity.
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Near-infrared light reduces glia activation and modulates neuroinflammation in the brains of diet-induced obese mice. Sci Rep 2022; 12:10848. [PMID: 35761012 PMCID: PMC9237037 DOI: 10.1038/s41598-022-14812-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 06/13/2022] [Indexed: 12/06/2022] Open
Abstract
Neuroinflammation is a key event in neurodegenerative conditions such as Alzheimer's disease (AD) and characterizes metabolic pathologies like obesity and type 2 diabetes (T2D). Growing evidence in humans shows that obesity increases the risk of developing AD by threefold. Hippocampal neuroinflammation in rodents correlates with poor memory performance, suggesting that it contributes to cognitive decline. Here we propose that reducing obesity/T2D-driven neuroinflammation may prevent the progression of cognitive decline associated with AD-like neurodegenerative states. Near-infrared light (NIR) has attracted increasing attention as it was shown to improve learning and memory in both humans and animal models. We previously reported that transcranial NIR delivery reduced amyloid beta and Tau pathology and improved memory function in mouse models of AD. Here, we report the effects of NIR in preventing obesity-induced neuroinflammation in a diet-induced obese mouse model. Five-week-old wild-type mice were fed a high-fat diet (HFD) for 13 weeks to induce obesity prior to transcranial delivery of NIR for 4 weeks during 90-s sessions given 5 days a week. After sacrifice, brain slices were subjected to free-floating immunofluorescence for microglia and astrocyte markers to evaluate glial activation and quantitative real-time polymerase chain reaction (PCR) to evaluate expression levels of inflammatory cytokines and brain-derived neurotrophic factor (BDNF). The hippocampal and cortical regions of the HFD group had increased expression of the activated microglial marker CD68 and the astrocytic marker glial fibrillary acidic protein. NIR-treated HFD groups showed decreased levels of these markers. PCR revealed that hippocampal tissue from the HFD group had increased levels of pro-inflammatory interleukin (IL)-1β and tumor necrosis factor-α. Interestingly, the same samples showed increased levels of the anti-inflammatory IL-10. All these changes were attenuated by NIR treatment. Lastly, hippocampal levels of the neurotrophic factor BDNF were increased in NIR-treated HFD mice, compared to untreated HFD mice. The marked reductions in glial activation and pro-inflammatory cytokines along with elevated BDNF provide insights into how NIR could reduce neuroinflammation. These results support the use of NIR as a potential non-invasive and preventive therapeutic approach against chronic obesity-induced deficits that are known to occur with AD neuropathology.
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Bhusal A, Rahman MH, Suk K. Hypothalamic inflammation in metabolic disorders and aging. Cell Mol Life Sci 2021; 79:32. [PMID: 34910246 PMCID: PMC11071926 DOI: 10.1007/s00018-021-04019-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/01/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022]
Abstract
The hypothalamus is a critical brain region for the regulation of energy homeostasis. Over the years, studies on energy metabolism primarily focused on the neuronal component of the hypothalamus. Studies have recently uncovered the vital role of glial cells as an additional player in energy balance regulation. However, their inflammatory activation under metabolic stress condition contributes to various metabolic diseases. The recruitment of monocytes and macrophages in the hypothalamus helps sustain such inflammation and worsens the disease state. Neurons were found to actively participate in hypothalamic inflammatory response by transmitting signals to the surrounding non-neuronal cells. This activation of different cell types in the hypothalamus leads to chronic, low-grade inflammation, impairing energy balance and contributing to defective feeding habits, thermogenesis, and insulin and leptin signaling, eventually leading to metabolic disorders (i.e., diabetes, obesity, and hypertension). The hypothalamus is also responsible for the causation of systemic aging under metabolic stress. A better understanding of the multiple factors contributing to hypothalamic inflammation, the role of the different hypothalamic cells, and their crosstalks may help identify new therapeutic targets. In this review, we focus on the role of glial cells in establishing a cause-effect relationship between hypothalamic inflammation and the development of metabolic diseases. We also cover the role of other cell types and discuss the possibilities and challenges of targeting hypothalamic inflammation as a valid therapeutic approach.
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Affiliation(s)
- Anup Bhusal
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
| | - Md Habibur Rahman
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- Division of Endocrinology, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Kyoungho Suk
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41944, Republic of Korea.
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Inhibition of mTOR signaling by genetic removal of p70 S6 kinase 1 increases anxiety-like behavior in mice. Transl Psychiatry 2021; 11:165. [PMID: 33723223 PMCID: PMC7960700 DOI: 10.1038/s41398-020-01187-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/31/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a ubiquitously expressed kinase that acts through two complexes, mTORC1 and mTORC2, to regulate protein homeostasis, as well as long lasting forms of synaptic and behavioral plasticity. Alteration of the mTOR pathway is classically involved in neurodegenerative disorders, and it has been linked to dysregulation of cognitive functions and affective states. However, information concerning the specific involvement of the p70 S6 kinase 1 (S6K1), a downstream target of the mTORC1 pathway, in learning and memory processes and in the regulation of affective states remains scant. To fill this gap, we exposed adult male mice lacking S6K1 to a battery of behavioral tests aimed at measuring their learning and memory capabilities by evaluating reference memory and flexibility with the Morris water maze, and associative memory using the contextual fear conditioning task. We also studied their anxiety-like and depression-like behaviors by, respectively, performing elevated plus maze, open field, light-dark emergence tests, and sucrose preference and forced swim tests. We found that deleting S6K1 leads to a robust anxious phenotype concomitant with associative learning deficits; these symptoms are associated with a reduction of adult neurogenesis and neuronal atrophy in the hippocampus. Collectively, these results provide grounds for the understanding of anxiety reports after treatments with mTOR inhibitors and will be critical for developing novel compounds targeting anxiety.
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Tavares RL, de Vasconcelos MHA, Dutra MLDV, D’Oliveira AB, Lima MDS, Salvadori MGDSS, Pereira RDA, Alves AF, do Nascimento YM, Tavares JF, Guzman-Quevedo O, Aquino JDS. Mucuna pruriens Administration Minimizes Neuroinflammation and Shows Anxiolytic, Antidepressant and Slimming Effects in Obese Rats. Molecules 2020; 25:molecules25235559. [PMID: 33256223 PMCID: PMC7730813 DOI: 10.3390/molecules25235559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/08/2020] [Accepted: 11/14/2020] [Indexed: 12/11/2022] Open
Abstract
This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract.
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Affiliation(s)
- Renata leite Tavares
- Experimental Nutrition Laboratory, Department of Nutrition, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (R.l.T.); (M.H.A.d.V.); (M.L.d.V.D.); (A.B.D.)
| | - Maria Helena Araújo de Vasconcelos
- Experimental Nutrition Laboratory, Department of Nutrition, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (R.l.T.); (M.H.A.d.V.); (M.L.d.V.D.); (A.B.D.)
| | - Maria Letícia da Veiga Dutra
- Experimental Nutrition Laboratory, Department of Nutrition, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (R.l.T.); (M.H.A.d.V.); (M.L.d.V.D.); (A.B.D.)
| | - Aline Barbosa D’Oliveira
- Experimental Nutrition Laboratory, Department of Nutrition, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (R.l.T.); (M.H.A.d.V.); (M.L.d.V.D.); (A.B.D.)
| | - Marcos dos Santos Lima
- Department of Food Technology, Federal Institute of Sertão Pernambucano, Rod. BR 407 km 08, s/n-Jardim São Paulo, Petrolina 56314-522, Brazil;
| | | | - Ramon de Alencar Pereira
- Pathology Laboratory, Department of Pathology, Federal University of Minas Gerais, Av. Pres. Antônio Carlos, n.6627-Pampulha, Belo Horizonte 31270-901, Brazil;
| | - Adriano Francisco Alves
- Department of Physiology and Pathology, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil;
| | - Yuri Mangueira do Nascimento
- Pharmaceutical Technology Laboratory, Department of Pharmaceutical Sciences, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (Y.M.d.N.); (J.F.T.)
| | - Josean Fechine Tavares
- Pharmaceutical Technology Laboratory, Department of Pharmaceutical Sciences, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (Y.M.d.N.); (J.F.T.)
| | - Omar Guzman-Quevedo
- Laboratory Neuronutrition and Metabolic Disorders, Higher Technological Institute of Tacámbaro, Av. Tecnológico 201, Tecario, Tacámbaro 61651, Mexico;
| | - Jailane de Souza Aquino
- Experimental Nutrition Laboratory, Department of Nutrition, Federal University of Paraíba, Cidade Universitária, s/n-Castelo Branco III, João Pessoa 58051-085, Brazil; (R.l.T.); (M.H.A.d.V.); (M.L.d.V.D.); (A.B.D.)
- Correspondence: ; Tel.: +55-83-3209-8715
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Reduced plasma Fetuin-A is a promising biomarker of depression in the elderly. Eur Arch Psychiatry Clin Neurosci 2020; 270:901-910. [PMID: 31863164 DOI: 10.1007/s00406-019-01090-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 12/11/2019] [Indexed: 12/20/2022]
Abstract
Depression affects 7% of the elderly population, and it often remains misdiagnosed or untreated. Peripheral biomarkers might aid clinicians by allowing more accurate and well-timed recognition of the disease. We sought to determine if plasma protein levels predict the severity of depressive symptomatology or distinguish patients from healthy individuals. The severity of depressive symptoms and global cognitive functioning were assessed by the Geriatric Depression Scale (GDS) and Mini-Mental State Examination (MMSE) in 152 elderly subjects, 76 of which with major depressive disorder (MDD). Plasma levels of 24 proteins were measured by multiplexing and analyzed as continuous predictors or dichotomized using the median value. The association between individual plasma proteins and MDD risk or depressive symptoms severity was investigated using multiple logistic and linear regressions including relevant covariates. Sensitivity analyses were performed excluding cognitively impaired individuals or non-acute patients with MDD. After adjusting for possible confounders and false discovery rate (FDR) correction, we found lower Fetuin-A levels in MDD patients vs. controls (pFDR = 1.95 × 10-6). This result was confirmed by the sensitivity and dichotomized analyses. Lower prolactin (PRL) levels predicted more severe depressive symptoms in acute MDD patients (pFDR = 0.024). Fetuin-A is a promising biomarker of MDD in the elderly as this protein was negatively associated with the disorder in our sample, regardless of the global cognitive functioning. Lower PRL levels may be a peripheral signature of impaired neuroprotective processes and serotoninergic neurotransmission in more severely depressed patients.
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Psychological Climacteric Symptoms and Attitudes toward Menopause among Emirati Women. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17145028. [PMID: 32668726 PMCID: PMC7400692 DOI: 10.3390/ijerph17145028] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022]
Abstract
Menopause is an inevitable developmental event that women encounter at an age of 42–54 years. The drop of estrogen levels that accompanies cessation of menstruation is associated with multiple vasomotor, physical, neuropsychological, and sexual symptoms, which may hamper quality of life. This study aimed to examine the severity of psychological symptoms and their correlates among peri- and postmenopausal Emirati women (N = 60, mean age = 54.88 ± 6 years). Participants were interviewed using the Menopause-Specific Quality of Life (MENQOL) and attitudes toward menopause scale (ATMS). In four path analysis models, vasomotor symptoms, weight gain, and fatigue had significant direct effects on symptoms of anxiety, depression (only weight gain and fatigue), and psychological distress. Fatigue significantly mediated the effects of vasomotor symptoms and weight gain on symptoms of anxiety, depression (only vasomotor symptoms), psychological distress, and memory problems. These models explained 47.6%, 44.5%, 56.6%, and 29.1% of the variances in anxiety, depression, psychological distress, and memory problems, respectively. Participants with more severe menopausal symptoms expressed more negative attitudes toward menopause though regression analysis revealed that only vasomotor symptoms could significantly contribute to ATMS scores. In conclusion, psychological distress is widespread among menopausal women, and it is associated with vasomotor symptoms, fatigue, and change of body composition (obesity). Psychological symptoms, along with vasomotor symptoms, express a key link to negative attitudes toward menopause. Therefore, interventional strategies that target psychological distress may promote coping with midlife transition and improve mental health among menopausal women.
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