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Hu T, Wei JW, Zheng JY, Luo QY, Hu XR, Du Q, Cai YF, Zhang SJ. Metformin improves cognitive dysfunction through SIRT1/NLRP3 pathway-mediated neuroinflammation in db/db mice. J Mol Med (Berl) 2024:10.1007/s00109-024-02465-1. [PMID: 38953935 DOI: 10.1007/s00109-024-02465-1] [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: 10/24/2023] [Revised: 05/29/2024] [Accepted: 06/23/2024] [Indexed: 07/04/2024]
Abstract
Diabetes mellitus (DM), an important public health problem, aggravates the global economic burden. Diabetic encephalopathy (DE) is a serious complication of DM in the central nervous system. Metformin has been proven to improve DE. However, the mechanism is still unclear. In this study, the db/db mice, a common model used for DE, were employed to explore and study the neuroprotective effect of metformin and related mechanisms. Behavioral tests indicated that metformin (100 or 200 mg/kg/day) could significantly improve the learning and memory abilities of db/db mice. The outcomes from the oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) demonstrate that metformin effectively modulates glucose and insulin signaling pathways in db/db mice. The results of body weight and blood lipid panel (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) show that metformin promotes the level of lipid metabolism in db/db mice. Furthermore, data from oxidative stress assays, which measured levels of malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase, suggest that metformin suppresses oxidative stress-induced brain damage in db/db mice. In addition, western blot, Nissl staining, and immunofluorescence results showed that metformin increased the expressions of nerve growth factor and postsynaptic density 95 and repaired neuronal structural damage. For the mechanism study, metformin activated SIRT1 and inhibited the expression of NLRP3 inflammasome (NLRP3, ASC, caspase-1, IL-1β, and IL-18) and inflammatory cytokines (TNFα and IL-6). In conclusion, metformin could ameliorate cognitive dysfunction through the SIRT1/NLRP3 pathway, which might be a promising mechanism for DE treatment.
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Affiliation(s)
- Tian Hu
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Jun-Wen Wei
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Jia-Yi Zheng
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China
| | - Qing-Yi Luo
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Xin-Rui Hu
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, 999077, China
| | - Qun Du
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
| | - Ye-Feng Cai
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China.
| | - Shi-Jie Zhang
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
- Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China.
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Arthur R, Jamwal S, Kumar P. A review on polyamines as promising next-generation neuroprotective and anti-aging therapy. Eur J Pharmacol 2024; 978:176804. [PMID: 38950837 DOI: 10.1016/j.ejphar.2024.176804] [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: 03/25/2024] [Revised: 06/28/2024] [Accepted: 06/28/2024] [Indexed: 07/03/2024]
Abstract
Neurodegenerative disorders are diseases characterized by progressive degeneration of neurons and associated structures and are a major global issue growing more widespread as the global population's average age increases. Despite several investigations on their etiology, the specific cause of these disorders remains unknown. However, there are few symptomatic therapies to treat these disorders. Polyamines (PAs) (putrescine, spermidine, and spermine) are being studied for their role in neuroprotection, aging and cognitive impairment. They are ubiquitous polycations which have relatively higher concentrations in the brain and possess pleiotropic biochemical activities, including regulation of gene expression, ion channels, mitochondria Ca2+ transport, autophagy induction, programmed cell death, and many more. Their cellular content is tightly regulated, and substantial evidence indicates that their altered levels and metabolism are strongly implicated in aging, stress, cognitive dysfunction, and neurodegenerative disorders. In addition, dietary polyamine supplementation has been reported to induce anti-aging effects, anti-oxidant effects, and improve locomotor abnormalities, and cognitive dysfunction. Thus, restoring the polyamine level is considered a promising pharmacological strategy to counteract neurodegeneration. This review highlights PAs' physiological role and the molecular mechanism underpinning their proposed neuroprotective effect in aging and neurodegenerative disorders.
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Affiliation(s)
- Richmond Arthur
- Department of Pharmacology, Central University of Punjab, Bathinda, India
| | - Sumit Jamwal
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Puneet Kumar
- Department of Pharmacology, Central University of Punjab, Bathinda, India.
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Isop LM, Neculau AE, Necula RD, Kakucs C, Moga MA, Dima L. Metformin: The Winding Path from Understanding Its Molecular Mechanisms to Proving Therapeutic Benefits in Neurodegenerative Disorders. Pharmaceuticals (Basel) 2023; 16:1714. [PMID: 38139841 PMCID: PMC10748332 DOI: 10.3390/ph16121714] [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: 09/12/2023] [Revised: 11/25/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Metformin, a widely prescribed medication for type 2 diabetes, has garnered increasing attention for its potential neuroprotective properties due to the growing demand for treatments for Alzheimer's, Parkinson's, and motor neuron diseases. This review synthesizes experimental and clinical studies on metformin's mechanisms of action and potential therapeutic benefits for neurodegenerative disorders. A comprehensive search of electronic databases, including PubMed, MEDLINE, Embase, and Cochrane library, focused on key phrases such as "metformin", "neuroprotection", and "neurodegenerative diseases", with data up to September 2023. Recent research on metformin's glucoregulatory mechanisms reveals new molecular targets, including the activation of the LKB1-AMPK signaling pathway, which is crucial for chronic administration of metformin. The pleiotropic impact may involve other stress kinases that are acutely activated. The precise role of respiratory chain complexes (I and IV), of the mitochondrial targets, or of the lysosomes in metformin effects remains to be established by further research. Research on extrahepatic targets like the gut and microbiota, as well as its antioxidant and immunomodulatory properties, is crucial for understanding neurodegenerative disorders. Experimental data on animal models shows promising results, but clinical studies are inconclusive. Understanding the molecular targets and mechanisms of its effects could help design clinical trials to explore and, hopefully, prove its therapeutic effects in neurodegenerative conditions.
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Affiliation(s)
- Laura Mihaela Isop
- Department of Fundamental, Prophylactic and Clinical Sciences, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania; (L.M.I.)
| | - Andrea Elena Neculau
- Department of Fundamental, Prophylactic and Clinical Sciences, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania; (L.M.I.)
| | - Radu Dan Necula
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania
| | - Cristian Kakucs
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania
| | - Marius Alexandru Moga
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania
| | - Lorena Dima
- Department of Fundamental, Prophylactic and Clinical Sciences, Faculty of Medicine, Transilvania University of Brasov, 500036 Brașov, Romania; (L.M.I.)
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Yonamine CY, Michalani MLE, Moreira RJ, Machado UF. Glucose Transport and Utilization in the Hippocampus: From Neurophysiology to Diabetes-Related Development of Dementia. Int J Mol Sci 2023; 24:16480. [PMID: 38003671 PMCID: PMC10671460 DOI: 10.3390/ijms242216480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
The association of diabetes with cognitive dysfunction has at least 60 years of history, which started with the observation that children with type 1 diabetes mellitus (T1D), who had recurrent episodes of hypoglycemia and consequently low glucose supply to the brain, showed a deficit of cognitive capacity. Later, the growing incidence of type 2 diabetes mellitus (T2D) and dementia in aged populations revealed their high association, in which a reduced neuronal glucose supply has also been considered as a key mechanism, despite hyperglycemia. Here, we discuss the role of glucose in neuronal functioning/preservation, and how peripheral blood glucose accesses the neuronal intracellular compartment, including the exquisite glucose flux across the blood-brain barrier (BBB) and the complex network of glucose transporters, in dementia-related areas such as the hippocampus. In addition, insulin resistance-induced abnormalities in the hippocampus of obese/T2D patients, such as inflammatory stress, oxidative stress, and mitochondrial stress, increased generation of advanced glycated end products and BBB dysfunction, as well as their association with dementia/Alzheimer's disease, are addressed. Finally, we discuss how these abnormalities are accompained by the reduction in the expression and translocation of the high capacity insulin-sensitive glucose transporter GLUT4 in hippocampal neurons, which leads to neurocytoglycopenia and eventually to cognitive dysfunction. This knowledge should further encourage investigations into the beneficial effects of promising therapeutic approaches which could improve central insulin sensitivity and GLUT4 expression, to fight diabetes-related cognitive dysfunctions.
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Affiliation(s)
- Caio Yogi Yonamine
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark;
| | - Maria Luiza Estimo Michalani
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
| | - Rafael Junges Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
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Patil R, Aswar U, Vyas N. Pterostilbene ameliorates type-2 diabetes mellitus - Induced depressive-like behavior by mitigating insulin resistance, inflammation and ameliorating HPA axis dysfunction in rat brain. Brain Res 2023; 1817:148494. [PMID: 37478963 DOI: 10.1016/j.brainres.2023.148494] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 07/13/2023] [Accepted: 07/17/2023] [Indexed: 07/23/2023]
Abstract
One of the most serious mental health comorbidities associated with diabetes mellitus is depression. The occurrence is almost double in type 2 diabetes mellitus (T2DM) compared with the general population. Pterostilbene (PTE), a dimethylated analog of resveratrol, has been reported for significant neuroprotective, anti-inflammatory, hypolipidemic, hypoglycaemic and antioxidant effects. However, its effect on diabetes-induced depression-like behavior (DID) has not been studied. The current study aimed at studying the effects of PTE on depressive-like behavior in male Wistar rats with T2DM. It was induced by single dose administration of nicotinamide (NA) and streptozotocin (STZ). On day 21, forced swim test (FST) was conducted for the confirmation of DID. Rats demonstrating depressive-like behavior were treated with PTE (10, 20 and 40 mg/kg), metformin (MET; 500 mg/kg) and fluoxetine (FLX; 10 mg/kg) for 28 days, orally. At the end of the treatment, behavioral assessment for depression, blood glucose (BG) and lipid profile, oxidative stress markers, gene expression of Sirtuin 1 (SIRT1) and histopathological parameters were investigated. PTE significantly reduced weight loss and mitigated depressive-like behavior paradigms such as sucrose preference test (SPT), resident intruder test (RIT) and open field test (OFT). It significantly restored BG, lipid and liver profile, creatinine and antioxidant level. It Improved glucose tolerance, insulin resistance (IR) and reduced cortisol level as well as inflammatory markers. It showed improved morphology of the pancreas, brain, liver and kidney. Gene expression studies revealed that, PTE significantly increased SIRT1 expression. PTE by its virtue to maintain BG, reduced IR, amelioration of the HPA axis, anti-inflammatory, antioxidant activity and improvement of SIRT1 gene expression proved to be effective in the treatment of DID-like behavior in rats.
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Affiliation(s)
- Rashmi Patil
- Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Erandwane, Pune 411038, India
| | - Urmila Aswar
- Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Erandwane, Pune 411038, India.
| | - Nishant Vyas
- Logical Life Sciences Private Limited, Pune, India
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