1
|
Giraldo-Berrio D, Jimenez-Del-Rio M, Velez-Pardo C. Sildenafil Reverses the Neuropathological Alzheimer's Disease Phenotype in Cholinergic-Like Neurons Carrying the Presenilin 1 E280A Mutation. J Alzheimers Dis 2024; 99:639-656. [PMID: 38728184 DOI: 10.3233/jad-231169] [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] [Indexed: 05/12/2024]
Abstract
Background Familial Alzheimer's disease (FAD) presenilin 1 E280A (PSEN 1 E280A) is characterized by functional impairment and the death of cholinergic neurons as a consequence of amyloid-β (Aβ) accumulation and abnormal phosphorylation of the tau protein. Currently, there are no available therapies that can cure FAD. Therefore, new therapies are urgently needed for treating this disease. Objective To assess the effect of sildenafil (SIL) on cholinergic-like neurons (ChLNs) harboring the PSEN 1 E280A mutation. Methods Wild-type (WT) and PSEN 1 E280A ChLNs were cultured in the presence of SIL (25μM) for 24 h. Afterward, proteinopathy, cell signaling, and apoptosis markers were evaluated via flow cytometry and fluorescence microscopy. Results We found that SIL was innocuous toward WT PSEN 1 ChLNs but reduced the accumulation of intracellular Aβ fragments by 87%, decreased the non-physiological phosphorylation of the protein tau at residue Ser202/Thr205 by 35%, reduced the phosphorylation of the proapoptotic transcription factor c-JUN at residue Ser63/Ser73 by 63%, decreased oxidized DJ-1 at Cys106-SO3 by 32%, and downregulated transcription factor TP53 (tumor protein p53), BH-3-only protein PUMA (p53 upregulated modulator of apoptosis), and cleaved caspase 3 (CC3) expression by 20%, 32%, and 22%, respectively, compared with untreated mutant ChLNs. Interestingly, SIL also ameliorated the dysregulation of acetylcholine-induced calcium ion (Ca2+) influx in PSEN 1 E280A ChLNs. Conclusions Although SIL showed no antioxidant capacity in the oxygen radical absorbance capacity and ferric ion reducing antioxidant power assays, it might function as an anti-amyloid and antiapoptotic agent and functional neuronal enhancer in PSEN 1 E280A ChLNs. Therefore, the SIL has therapeutic potential for treating FAD.
Collapse
Affiliation(s)
- Daniela Giraldo-Berrio
- Neuroscience Research Group, Institute of Medical Investigations, Faculty of Medicine, University of Antioquia (UdeA), Medellín, Colombia
| | - Marlene Jimenez-Del-Rio
- Neuroscience Research Group, Institute of Medical Investigations, Faculty of Medicine, University of Antioquia (UdeA), Medellín, Colombia
| | - Carlos Velez-Pardo
- Neuroscience Research Group, Institute of Medical Investigations, Faculty of Medicine, University of Antioquia (UdeA), Medellín, Colombia
| |
Collapse
|
2
|
Pușcașu C, Zanfirescu A, Negreș S, Șeremet OC. Exploring the Multifaceted Potential of Sildenafil in Medicine. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:2190. [PMID: 38138293 PMCID: PMC10744870 DOI: 10.3390/medicina59122190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023]
Abstract
Phosphodiesterase type 5 (PDE5) is pivotal in cellular signalling, regulating cyclic guanosine monophosphate (cGMP) levels crucial for smooth muscle relaxation and vasodilation. By targeting cGMP for degradation, PDE5 inhibits sustained vasodilation. PDE5 operates in diverse anatomical regions, with its upregulation linked to various pathologies, including cancer and neurodegenerative diseases. Sildenafil, a selective PDE5 inhibitor, is prescribed for erectile dysfunction and pulmonary arterial hypertension. However, considering the extensive roles of PDE5, sildenafil might be useful in other pathologies. This review aims to comprehensively explore sildenafil's therapeutic potential across medicine, addressing a gap in the current literature. Recognising sildenafil's broader potential may unveil new treatment avenues, optimising existing approaches and broadening its clinical application.
Collapse
Affiliation(s)
| | - Anca Zanfirescu
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (O.C.Ș.)
| | | | | |
Collapse
|
3
|
Horvat A, Vlašić I, Štefulj J, Oršolić N, Jazvinšćak Jembrek M. Flavonols as a Potential Pharmacological Intervention for Alleviating Cognitive Decline in Diabetes: Evidence from Preclinical Studies. Life (Basel) 2023; 13:2291. [PMID: 38137892 PMCID: PMC10744738 DOI: 10.3390/life13122291] [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: 09/30/2023] [Revised: 11/15/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Diabetes mellitus is a complex metabolic disease associated with reduced synaptic plasticity, atrophy of the hippocampus, and cognitive decline. Cognitive impairment results from several pathological mechanisms, including increased levels of advanced glycation end products (AGEs) and their receptors, prolonged oxidative stress and impaired activity of endogenous mechanisms of antioxidant defense, neuroinflammation driven by the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), decreased expression of brain-derived neurotrophic factor (BDNF), and disturbance of signaling pathways involved in neuronal survival and cognitive functioning. There is increasing evidence that dietary interventions can reduce the risk of various diabetic complications. In this context, flavonols, a highly abundant class of flavonoids in the human diet, are appreciated as a potential pharmacological intervention against cognitive decline in diabetes. In preclinical studies, flavonols have shown neuroprotective, antioxidative, anti-inflammatory, and memory-enhancing properties based on their ability to regulate glucose levels, attenuate oxidative stress and inflammation, promote the expression of neurotrophic factors, and regulate signaling pathways. The present review gives an overview of the molecular mechanisms involved in diabetes-induced cognitive dysfunctions and the results of preclinical studies showing that flavonols have the ability to alleviate cognitive impairment. Although the results from animal studies are promising, clinical and epidemiological studies are still needed to advance our knowledge on the potential of flavonols to improve cognitive decline in diabetic patients.
Collapse
Affiliation(s)
- Anđela Horvat
- Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Ignacija Vlašić
- Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Jasminka Štefulj
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
- Department of Psychology, Catholic University of Croatia, Ilica 242, 10000 Zagreb, Croatia
| | - Nada Oršolić
- Division of Animal Physiology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Maja Jazvinšćak Jembrek
- Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
- Department of Psychology, Catholic University of Croatia, Ilica 242, 10000 Zagreb, Croatia
| |
Collapse
|
4
|
Yang YT, Yan B, Li YH, Guo LN, Wang WW, Liu LJ, Yu HG, Diao H. Phosphodiesterase 10A inhibitor PF-2545920 as a prospective agent for the clinical promotion of sperm motility. Asian J Androl 2023; 25:373415. [PMID: 37026191 PMCID: PMC10521960 DOI: 10.4103/aja2022117] [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: 08/19/2022] [Accepted: 02/07/2023] [Indexed: 04/08/2023] Open
Abstract
Phosphodiesterase (PDE) inhibitors can improve sperm motility in patients with asthenozoospermia. However, the most commonly reported nonselective PDE inhibitor pentoxifylline and PDE5 inhibitor sildenafil have the disadvantages of requiring a high concentration and destroying sperm integrity. We examined the PDE10A inhibitor PF-2545920 to compare its ability to promote sperm motility with that of pentoxifylline and sildenafil. After seminal plasma was discarded, several semen samples were subjected to four treatments (control, PF-2545920, pentoxifylline, and sildenafil) to evaluate their ability to affect motility, viability, and spontaneous acrosome reactions. Intracellular calcium and adenosine triphosphate (ATP), mitochondrial membrane potential, and penetration through viscous medium were assessed by flow cytometry, luciferase, and hyaluronic acid after treatment with PF-2545920. Statistical analyses were performed using the analysis of variance statistical test. PF-2545920 elevated the percentage of motile spermatozoa compared to the control, pentoxifylline, and sildenafil groups at 10 µmol l -1 ( P < 0.01). It is less toxic to GC-2spd mouse spermatocytes cells and spermatozoa and causes fewer spontaneous acrosomal reactions ( P < 0.05). PF-2545920 also increased mitochondrial membrane potential ( P < 0.001) and altered intracellular calcium ( P < 0.05) in a dose-dependent manner, including increasing sperm hyaluronic acid penetrating ability ( P < 0.05). Therefore, PF-2545920 might be an excellent choice for stimulating the sperm motility.
Collapse
Affiliation(s)
- Yi-Ting Yang
- NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Bin Yan
- Reproductive Medicine Centre, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Yu-Hua Li
- NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Li-Na Guo
- NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Wei-Wei Wang
- School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Li-Jie Liu
- Department of Urology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - He-Guo Yu
- NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Hua Diao
- NHC Key Laboratory of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| |
Collapse
|
5
|
Wang S, Zeng X, Yang Y, Li S, Wang Y, Ye Q, Fan X. Hypothermic oxygenated perfusion ameliorates ischemia-reperfusion injury of fatty liver in mice via Brg1/Nrf2/HO-1 axis. Artif Organs 2022; 46:229-238. [PMID: 34570898 DOI: 10.1111/aor.14076] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/05/2021] [Accepted: 09/14/2021] [Indexed: 12/18/2022]
Abstract
BACKGROUND After cold storage (CS) and subsequent transplantation, fatty liver is more inclined to develop liver dysfunction and serious postoperative complications in contrast to healthy liver. Hypothermic oxygenated perfusion (HOPE) is a safe and efficacious system, which can repair fatty liver and reduce ischemia-reperfusion injury. The aim of this research is to investigate the function of Brg1/Nrf2/HO-1 signaling pathway in the protective effect of HOPE on ischemia-reperfusion injury of fatty liver. METHODS The mouse fatty liver model was successfully established and verified by hematoxylin-eosin (HE) staining and oil red O staining. The animals were divided into Control group, CS group and HOPE group. The levels of liver enzyme and lactate in the perfusate were used to measure liver function and cellular metabolism. HE staining and TUNEL staining were utilized to assess the tissue structure and apoptosis, respectively. The levels of superoxide dismutase, malondialdehyde and reactive oxygen species in liver tissue were measured to quantitatively analyze the degree of oxidative stress, and the expressions of protein Brg1, Nrf2 and HO-1 were detected by means of the western blot. Double-labeling immunofluorescence was to explore the colocalization of Brg1 and Nrf2. RESULTS The injury of the liver in the CS group was more serious than that in the control group. However, HOPE could significantly reduce the injury, which was manifested by the improvement of liver function and cellular metabolism, and the lower degrees of apoptosis, necrosis and oxidative stress. Furthermore, the expressions of Brg1, Nrf2 and HO-1 in the HOPE group were significantly increased than those in the CS group. CONCLUSIONS One-hour HOPE treatment before reperfusion can obviously improve the injury of fatty liver in mice. The underlying mechanism may be that the interaction of Brg1 and Nrf2 can selectively activate the transcription of HO-1.
Collapse
Affiliation(s)
- Shengjie Wang
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
| | - Xianpeng Zeng
- Department of Urology, Union Hospital, Affiliated TongJi Medical College, Huazhong University of Science & Technology, Wuhan, China
| | - Yunying Yang
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
| | - Shiyi Li
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
| | - Yanfeng Wang
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
| | - Qifa Ye
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
- Research Center of National Health Ministry on Transplantation Medicine Engineering and Technology, The 3rd Xiangya Hospital of Central South University, Changsha, China
| | - Xiaoli Fan
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China
| |
Collapse
|
6
|
Abstract
Substantial evidence, composed of drug mechanisms of action, in vivo testing, and epidemiological data, exists to support clinical testing of FDA-approved drugs for repurposing to the treatment of Alzheimer’s disease (AD). Licensed compound investigation can often proceed at a faster and more cost-effective manner than un-approved compounds moving through the drug pipeline. As the prevalence of AD increases with life expectancy, the current rise in life expectancy amalgamated with the lack of an effective drug for the treatment of AD unnecessarily burdens our medical system and is an urgent public health concern. The unfounded reluctance to examine repurposing existing drugs for possible AD therapy further impedes the possibility of improving the quality of patient lives with a terminal disease. This review summarizes some evidence which exists to suggest certain already-approved drugs may be considered for the treatment of AD and will perhaps encourage physicians to off-label prescribe these safe therapeutics.
Collapse
|
7
|
Gan WJ, Gao CL, Zhang WQ, Gu JL, Zhao TT, Guo HL, Zhou H, Xu Y, Yu LL, Li LF, Gui DK, Xu YH. Kuwanon G protects HT22 cells from advanced glycation end product-induced damage. Exp Ther Med 2021; 21:425. [PMID: 33747164 PMCID: PMC7967837 DOI: 10.3892/etm.2021.9869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/11/2020] [Indexed: 12/25/2022] Open
Abstract
The incidence of diabetic encephalopathy is increasing as the population ages. Evidence suggests that formation and accumulation of advanced glycation end products (AGEs) plays a pivotal role in disease progression, but limited research has been carried out in this area. A previous study demonstrated that Kuwanon G (KWG) had significant anti-oxidative stress and anti-inflammatory properties. As AGEs are oxidative products and inflammation is involved in their generation it is hypothesized that KWG may have effects against AGE-induced neuronal damage. In the present study, mouse hippocampal neuronal cell line HT22 was used. KWG was shown to significantly inhibit AGE-induced cell apoptosis in comparison with a control treatment, as determined by both MTT and flow cytometry. Compared with the AGEs group, expression of pro-apoptotic protein Bax was reduced and expression of anti-apoptotic protein Bcl-2 was increased in the AGEs + KWG group. Both intracellular and extracellular levels of acetylcholine and choline acetyltransferase were significantly elevated after KWG administration in comparison with controls whilethe level of acetylcholinesterase decreased. These changes in protein expression were accompanied by increased levels of superoxide dismutase and glutathione peroxidase synthesis and reduced production of malondialdehyde and reactive oxygen species. Intracellular signaling pathway protein levels were determined by western blot and immunocytochemistry. KWG administration was found to prevent AGE-induced changes to the phosphorylation levels of Akt, IκB-α, glycogen synthase kinase 3 (GSK3)-α and β, p38 MAPK and NF-κB p65 suggesting a potential neuroprotective effect of KWG against AGE-induced damage was via the PI3K/Akt/GSK3αβ signaling pathway. The findings of the present study suggest that KWG may be a potential treatment for diabetic encephalopathy.
Collapse
Affiliation(s)
- Wen-Jun Gan
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Chen-Lin Gao
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China.,Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 510500, P.R. China
| | - Wen-Qian Zhang
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Jun-Ling Gu
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Ting-Ting Zhao
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Heng-Li Guo
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Hua Zhou
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Yong Xu
- Department of Endocrinology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 510500, P.R. China
| | - Li-Li Yu
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Li-Fang Li
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| | - Ding-Kun Gui
- Department of Nephrology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - You-Hua Xu
- Faculty of Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR 999078, P.R. China
| |
Collapse
|
8
|
Ibrahim MA, Haleem M, AbdelWahab SA, Abdel-Aziz AM. Sildenafil ameliorates Alzheimer disease via the modulation of vascular endothelial growth factor and vascular cell adhesion molecule-1 in rats. Hum Exp Toxicol 2020; 40:596-607. [PMID: 32959702 DOI: 10.1177/0960327120960775] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Alzheimer disease (AD) is a chronic neurodegenerative disease with multi-pathways pathogenesis. Sildenafil is a selective phosphodiesterase-5 inhibitor with a potential benefit in the treatment of AD. This study investigated the possible mechanisms underlying the effect of sildenafil in AD with emphasis on vascular endothelial growth factor (VEGF), and vascular cell adhesion molecule-1 (VCAM-1). Twenty-four adult male rats were classified into four groups; control group: received vehicles, sildenafil-control: received sildenafil (15 mg/kg/day, p.o.), AD group received Aluminum (25 mg/kg/day, p.o.), AD-treated group: received sildenafil (15 mg/kg/day, p.o.) for 6 weeks. AD was assessed by memory performance test and confirmed by histopathological examination and immunostaining of, neurogenesis marker nestin and α-synuclein. The levels of VEGF-A, VCAM-1, oxidative stress markers and TNF-α in brain tissue were evaluated. AD rats showed histopathological evidences of AD; along with increased latency time in the memory test. There was a decrease in VEGF-A, and an increase in VCAM-1, TNF-α, and oxidative stress markers. Immunohistochemical study showed a significant increase in α-synuclein and a significant decrease in nestin expressions in brain tissues. Sildenafil administration ameliorated the histopathological changes and decreased latency time. Such effect was associated with a decrease in VCAM-1, TNF-α and oxidative stress as well as an increase in VEGF-A. Sildenafil caused a significant increase in nestin and a decrease in α-synuclein immunostaining. These findings suggested a protective effect of sildenafil via modulation of VEGF-A, and VCAM-1.
Collapse
Affiliation(s)
- M A Ibrahim
- Department of Pharmacology, 68877Faculty of Medicine, Minia University, Minia, Egypt
| | - Masa Haleem
- Department of Anatomy, 68877Faculty of Medicine, Minia University, Minia, Egypt
| | - S A AbdelWahab
- Department of Histology, 68877Faculty of Medicine, Minia University, Minia, Egypt.,Department of Basic Medical Science, Deraya University, New Minia, Egypt
| | - A M Abdel-Aziz
- Department of Pharmacology, 68877Faculty of Medicine, Minia University, Minia, Egypt
| |
Collapse
|
9
|
Abstract
Nitric oxide/cyclic guanosine monophosphate (cGMP) signaling is compromised in Alzheimer’s disease (AD), and phosphodiesterase 5 (PDE5), which degrades cGMP, is upregulated. Sildenafil inhibits PDE5 and increases cGMP levels. Integrating previous findings, we determine that most doses of sildenafil (especially low doses) likely activate peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) via protein kinase G-mediated cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) phosphorylation and/or Sirtuin-1 activation and PGC1α deacetylation. Via PGC1α signaling, low-dose sildenafil likely suppresses β-secretase 1 expression and amyloid-β (Aβ) generation, upregulates antioxidant enzymes, and induces mitochondrial biogenesis. Plus, sildenafil should increase brain perfusion, insulin sensitivity, long-term potentiation, and neurogenesis while suppressing neural apoptosis and inflammation. A systematic review of sildenafil in AD was undertaken. In vitro, sildenafil protected neural mitochondria from Aβ and advanced glycation end products. In transgenic AD mice, sildenafil was found to rescue deficits in CREB phosphorylation and memory, upregulate brain-derived neurotrophic factor, reduce reactive astrocytes and microglia, decrease interleukin-1β, interleukin-6, and tumor necrosis factor-α, decrease neural apoptosis, increase neurogenesis, and reduce tau hyperphosphorylation. All studies that tested Aβ levels reported significant improvements except the two that used the highest dosage, consistent with the dose-limiting effect of cGMP-induced phosphodiesterase 2 (PDE2) activation and cAMP depletion on PGC1α signaling. In AD patients, a single dose of sildenafil decreased spontaneous neural activity, increased cerebral blood flow, and increased the cerebral metabolic rate of oxygen. A randomized control trial of sildenafil (ideally with a PDE2 inhibitor) in AD patients is warranted.
Collapse
|
10
|
Jiang L, Wang J, Wang Z, Huang W, Yang Y, Cai Z, Li K. Role of the Glyoxalase System in Alzheimer's Disease. J Alzheimers Dis 2019; 66:887-899. [PMID: 30400091 DOI: 10.3233/jad-180413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease (AD) is an insidious and progressive neurodegenerative disease. The main pathological features of AD are the formation of amyloid-β deposits in the anterior cerebral cortex and hippocampus as well as the formation of intracellular neurofibrillary tangles. Thus far, accumulating evidence shows that glycation is closely related to AD. As a final product resulting from the crosslinking of a reducing sugar or other reactive carbonyls and a protein, the advanced glycation end products have been found to be associated with the formation of amyloid-β and neurofibrillary tangles in AD. As a saccharification inhibitor, the glyoxalase system and its substrate methylglyoxal (MG) were certified to be associated with AD onset and development. As an active substance of AGEs, MG could cause direct or indirect damage to nerve cells and tissues. MG is converted to D-lactic acid after decomposition by the glyoxalase system. Under normal circumstances, MG metabolism is in a dynamic equilibrium, whereas MG accumulates in cells in the case of aging or pathological states. Studies have shown that increasing glyoxalase activity and reducing the MG level can inhibit the generation of oxidative stress and AGEs, thereby alleviating the symptoms and signs of AD to some extent. This paper focuses on the relevant mechanisms of action of the glyoxalase system and MG in the pathogenesis of AD, as well as the potential of inhibiting the production of advanced glycation end products in the treatment of AD.
Collapse
Affiliation(s)
- Lianying Jiang
- Department of Neurology, Stem Cell Research and Clinical Translation Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Jiafeng Wang
- Department of Neurology, Stem Cell Research and Clinical Translation Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Zhigang Wang
- Department of Neurosurgery, Jiangxi Medical College of Nanchang University, Nanchang, Jiangxi, China
| | - Wenhui Huang
- Department of Neurology and Stroke Center, the First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Yixia Yang
- Department of Neurology, Stem Cell Research and Clinical Translation Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Zhiyou Cai
- Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, People's Republic of China
| | - Keshen Li
- Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China; Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| |
Collapse
|