Neurodegeneration In Mouse Brain Research Articles

Alpha-Linolenic Acid Impedes Cadmium-Induced Oxidative Stress, Neuroinflammation, and Neurodegeneration in Mouse Brain.

Alpha-Linolenic acid (ALA), an omega-3 polyunsaturated fatty acid, is extracted from plant sources and has been shown to be one of the anti-inflammatory and antioxidant agents. Herein, we revealed the molecular mechanism underlying the anti-inflammatory and antioxidant potential of (ALA), against cadmium in the adult mouse brain. We evaluated the neuroprotective effect of ALA (60 mg/kg per oral for 6 weeks) against CdCl2 (5 mg/kg)-induced oxidative stress, neuroinflammation, and neuronal apoptosis. According to our findings, ALA markedly reduced ROS production and nitric oxide synthase 2 (NOS2) and enhanced the expression of nuclear factor-2 erythroid-2 (Nrf-2) and heme oxygenase-1 (HO-1) in mice treated with CdCl2. Most importantly, the molecular docking study revealed that ALA allosterically decreases the overexpression of c-Jun N-terminal kinase (JNK) activity and inhibited the detrimental effect against CdCl2. Moreover, ALA suppressed CdCl2-induced glial fibrillary acidic protein (GFAP), nuclear factor-kappa b (NF-κB), and interleukin-1β (IL-1β) in the mouse brain. Further, we also checked the pro- and anti-apoptotic proteins markers such as Bax, Bcl-2, and caspase-3, which were regulated in the cortex of ALA co-treated mouse brain. Overall, our study suggests that oral administration of ALA can impede oxidative stress, neuroinflammation, and increase neuronal apoptosis in the cortex of Cd-injected mouse brain.

Nicotinamide Ameliorates Amyloid Beta-Induced Oxidative Stress-Mediated Neuroinflammation and Neurodegeneration in Adult Mouse Brain.

Alzheimer’s disease (AD) is the most predominant age-related neurodegenerative disease, pathologically characterized by the accumulation of aggregates of amyloid beta Aβ1–42 and tau hyperphosphorylation in the brain. It is considered to be the primary cause of cognitive dysfunction. The aggregation of Aβ1–42 leads to neuronal inflammation and apoptosis. Since vitamins are basic dietary nutrients that organisms need for their growth, survival, and other metabolic functions, in this study, the underlying neuroprotective mechanism of nicotinamide (NAM) Vitamin B3 against Aβ1–42 -induced neurotoxicity was investigated in mouse brains. Intracerebroventricular (i.c.v.) Aβ1–42 injection elicited neuronal dysfunctions that led to memory impairment and neurodegeneration in mouse brains. After 24 h after Aβ1–42 injection, the mice were treated with NAM (250 mg/kg intraperitoneally) for 1 week. For biochemical and Western blot studies, the mice were directly sacrificed, while for confocal and “immunohistochemical staining”, mice were perfused transcardially with 4% paraformaldehyde. Our biochemical, immunofluorescence, and immunohistochemical results showed that NAM can ameliorate neuronal inflammation and apoptosis by reducing oxidative stress through lowering malondialdehyde and 2,7-dichlorofluorescein levels in an Aβ1–42-injected mouse brains, where the regulation of p-JNK further regulated inflammatory marker proteins (TNF-α, IL-1β, transcription factor NF-kB) and apoptotic marker proteins (Bax, caspase 3, PARP1). Furthermore, NAM + Aβ treatment for 1 week increased the amount of survival neurons and reduced neuronal cell death in Nissl staining. We also analyzed memory dysfunction via behavioral studies and the analysis showed that NAM could prevent Aβ1–42 -induced memory deficits. Collectively, the results of this study suggest that NAM may be a potential preventive and therapeutic candidate for Aβ1–42 -induced reactive oxygen species (ROS)-mediated neuroinflammation, neurodegeneration, and neurotoxicity in an adult mouse model.

Vanillic Acid, a Bioactive Phenolic Compound, Counteracts LPS-Induced Neurotoxicity by Regulating c-Jun N-Terminal Kinase in Mouse Brain.

The receptor for advanced glycation end products (RAGE), a pattern recognition receptor signaling event, has been associated with several human illnesses, including neurodegenerative diseases, particularly in Alzheimer’s disease (AD). Vanillic acid (V.A), a flavoring agent, is a benzoic acid derivative having a broad range of biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. However, the underlying molecular mechanisms of V.A in exerting neuroprotection are not well investigated. The present study aims to explore the neuroprotective effects of V.A against lipopolysaccharides (LPS)-induced neuroinflammation, amyloidogenesis, synaptic/memory dysfunction, and neurodegeneration in mice brain. Behavioral tests and biochemical and immunofluorescence assays were applied. Our results indicated increased expression of RAGE and its downstream phospho-c-Jun n-terminal kinase (p-JNK) in the LPS-alone treated group, which was significantly reduced in the V.A + LPS co-treated group. We also found that systemic administration of LPS-injection induced glial cells (microglia and astrocytes) activation and significantly increased expression level of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-KB) and secretion of proinflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1 β (IL1-β), and cyclooxygenase (COX-2). However, V.A + LPS co-treatment significantly inhibited the LPS-induced activation of glial cells and neuroinflammatory mediators. Moreover, we also noted that V.A treatment significantly attenuated LPS-induced increases in the expression of AD markers, such as β-site amyloid precursor protein (APP)–cleaving enzyme 1 (BACE1) and amyloid-β (Aβ). Furthermore, V.A treatment significantly reversed LPS-induced synaptic loss via enhancing the expression level of pre- and post-synaptic markers (PSD-95 and SYP), and improved memory performance in LPS-alone treated group. Taken together; we suggest that neuroprotective effects of V.A against LPS-induced neurotoxicity might be via inhibition of LPS/RAGE mediated JNK signaling pathway; and encourage future studies that V.A would be a potential neuroprotective and neurotherapeutic candidate in various neurological disorders.

Isolation and identification of flavonoids from anticancer and neuroprotective extracts of <i>Trigonella foenum</i> graecum

Purpose: To evaluate the protective effects of Trigonella foenum graecum methanol and ethyl acetate extracts, against cancer cell lines and NaNO 2 -induced neurodegeneration in mice brain. Methods: Adult male albino mice ( n = 20) were administered NaNO 2 orally at a dose of 300 mg/kg for 15 days. The control group received distilled water and normal mice feed. Experimental groups were given T. foenum graecum methanol and ethyl acetate extracts in two different doses of 100 and 200 mg/kg orally for 15 days. Histopathological examination of the brain was carried out with the aid of cresyl violet and H&E staining. In addition, the cytotoxicity of the extracts was evaluated by 3-(4,5- dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay against HCEC, MCF-7 and Hep2 cell lines. Nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) were used to determine the structures of the bioactive compounds. Results: Methanol and ethyl acetate extracts of T. foenum graecum seeds inhibited neurodegeneration in the hippocampus and cortex regions of the brain when compared to control group. Moreover, the extracts exhibited anticancer activity against Hep2 and MCF-7cells and low cytotoxicity against HCEC, sparing healthy cells in-vitro . In addition, two flavonoids amurensin and cosmosiin were isolated from T. foenum graecum extracts. Conclusion: Amurensin and cosmosiin from T. foenum extracts are reported here for the first time agents that possess significant anticancer and neuroprotective properties. Keywords: Trigonella foenum-graecum , Anticancer, Neurodegeneration, Flavonoids, Amurensin, Cosmosiin

A β-synuclein mutation linked to dementia produces neurodegeneration when expressed in mouse brain

The discovery of α-synuclein (αS) mutations has made a major contribution to the understanding of the pathogenesis of α-synucleinopathies such as Parkinson's disease and dementia with Lewy bodies (DLB). In contrast, less attention has been paid to β-synuclein (βS) mutations. In this paper, we show that transgenic (tg) mice expressing DLB-linked P123H βS develop progressive neurodegeneration, as characterized by axonal swelling, astrogliosis and behavioural abnormalities, with memory disorder being more prominent than motor deficits. Furthermore, cross-breeding of P123H βS tg mice with αS tg mice, but not with αS knockout mice, greatly enhanced neurodegeneration phenotypes. These results suggest that P123H βS is pathogenic and cooperates with pathogenic αS to stimulate neurodegeneration in mouse brain, indicating a causative role of P123H βS in familial DLB. Given the neuritic pathology of βS in sporadic α-synucleinopathies, it appears that alteration of βS can contribute to the pathogenesis of a broad range of α-synucleinopathies.

Coexpression of Human cdk5 and Its Activator p35 with Human Protein Tau in Neurons in Brain of Triple Transgenic Mice

The potential contribution of cyclin-dependent protein kinase 5 (cdk5) to hyperphosphorylate protein tau, as claimed in Alzheimer's disease, was investigated in vivo. We generated single, double, and triple transgenic mice that coexpress human cdk5 and its activator p35 as well as human protein tau in cerebral neurons. Whereas expression and increased cdk5-kinase activity was obtained, as measured in vitro and demonstrated in vivo, neither murine nor human protein tau was appreciably phosphorylated in the brain of double and triple transgenic mice. These mice behaved and reproduced normally. Silver impregnation and immunohistochemistry of brain sections demonstrated that neurofilament proteins became redistributed in apical dendrites of cortical neurons. This suggested a cytoskeletal effect, but no other relevant brain pathology became apparent. These observations indicate that cdk5/p35 is not a major protein tau kinase and that cdk5/p35 did not cause neurodegeneration in mouse brain, as opposed to cdk5/p25.