Enhanced Cardiomyocyte NLRP3 Inflammasome-Mediated Pyroptosis Promotes d-Galactose-Induced Cardiac Aging.

BACKGROUND: Cardiac aging represents an independent risk factor for aging-associated cardiovascular diseases. Although evidence suggests an association between NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome formation and numerous cardiovascular diseases, its role in cardiac aging remains largely unclear. METHODS AND RESULTS: The longevity of mice with wild-type and NLRP3 knockout (NLRP3-/-) genotypes was assessed, with or without d-galactose treatment. Cardiac function was evaluated using echocardiography, and cardiac histopathology was examined through hematoxylin and eosin and Masson's trichrome staining. Senescence-associated ß-galactosidase (SA-ß-gal) staining was employed to detect cardiac aging. Western blotting was used to assess aging-related proteins (p53, p21) and pyroptosis-related proteins. Additionally, dihydroethidium staining, lactate dehydrogenase release, and interleukin-1ß ELISA assays were performed, along with measurements of total superoxide dismutase and malondialdehyde levels. In vitro, H9c2 cells were exposed to d-galactose for 24 hours in the absence or presence of N-acetyl-l-cysteine (reactive oxygen species inhibitor), BAY-117082 (nuclear factor κ-light-chain enhancer of activated B cells inhibitor), MCC950 (NLRP3 inhibitor), and VX-765 (Caspase-1 inhibitor). Immunofluorescence staining was employed to detect p53, gasdermin D, and apoptosis-associated speck-like protein proteins. Intracellular reactive oxygen species levels were assessed using fluorescence microscopy and flow cytometry. Senescence-associated ß-galactosidase staining and Western blotting were also employed in vitro for the same purpose. The results showed that NLRP3 upregulation was implicated in aging and cardiovascular diseases. Inhibition of NLRP3 extended life span, mitigated the aging phenotype, improved cardiac function and blood pressure, ameliorated lipid metabolism abnormalities, inhibited pyroptosis in cardiomyocytes, and ultimately alleviated cardiac aging. In vitro, the inhibition of reactive oxygen species, nuclear factor κ-light-chain enhancer of activated B cells, NLRP3, or caspase-1 attenuated NLRP3 inflammasome-mediated pyroptosis. CONCLUSIONS: The reactive oxygen species/nuclear factor κ-light-chain enhancer of activated B cells/NLRP3 signaling pathway loop contributes to d-galactose-treated cardiomyocyte senescence and cardiac aging.

Berberine attenuates brain aging via stabilizing redox homeostasis and inflammation in an accelerated senescence model of Wistar rats.

Aging is a multifaceted and progressive physiological change of the organism categorized by the accumulation of deteriorating processes, which ultimately compromise the biological functions. The objective of this study was to investigate the anti-aging potential of berberine (BBR) in D-galactose (D-Gal) induced aging in rat models. In this study, male Wistar rats were divided into four groups: The control group was given only vehicle, the BBR group was treated with berberine orally, the D-Gal group was treated with D-galactose subcutaneously and the BBR + D-Gal group was treated with D-galactose and berberine simultaneously. D-galactose exposure elevated the pro-oxidants such as malondialdehyde (MDA) level, protein carbonyl and advanced oxidation protein products (AOPP) in the brain. It decreased the anti-oxidants such as reduced glutathione (GSH) and ferric reducing antioxidant potential (FRAP) in the brain. D-galactose treatment also reduced the mitochondrial complexes (I, II, III and IV) activities and elevated the inflammatory markers such as interleukine-6 (IL-6), tumor necrosis factor- α (TNF-α) and C-reactive protein (CRP). The mRNA expressions of IL-6 and TNF-α in the brain were upregulated following D-galactose exposure. Berberine co-treatment in D-galactose induced aging rat model prevented the alteration of pro-oxidant and anti-oxidant in the brain. Berberine treatment restored the mitochondrial complex activities in the brain and also normalized the inflammatory markers. Based on these findings we conclude that berberine treatment has the potential to mitigate brain aging in rats via stabilizing the redox equilibrium and neuroinflammation.

Geraniol attenuates oxidative stress and neuroinflammation-mediated cognitive impairment in D galactose-induced mouse aging model.

D-galactose (D-gal) administration was proven to induce cognitive impairment and aging in rodents' models. Geraniol (GNL) belongs to the acyclic isoprenoid monoterpenes. GNL reduces inflammation by changing important signaling pathways and cytokines, and thus it is plausible to be used as a medicine for treating disorders linked to inflammation. Herein, we examined the therapeutic effects of GNL on D-gal-induced oxidative stress and neuroinflammation-mediated memory loss in mice. The study was conducted using six groups of mice (6 mice per group). The first group received normal saline, then D-gal (150 mg/wt) dissolved in normal saline solution (0.9%, w/v) was given orally for 9 weeks to the second group. In the III group, from the second week until the 10th week, mice were treated orally (without anesthesia) with D-gal (150 mg/kg body wt) and GNL weekly twice (40 mg/kg body wt) four hours later. Mice in Group IV were treated with GNL from the second week up until the end of the experiment. For comparison of young versus elderly mice, 4 month old (Group V) and 16-month-old (Group VI) control mice were used. We evaluated the changes in antioxidant levels, PI3K/Akt levels, and Nrf2 levels. We also examined how D-gal and GNL treated pathological aging changes. Administration of GNL induced a significant increase in spatial learning and memory with spontaneously altered behavior. Enhancing anti-oxidant and anti-inflammatory effects and activating PI3K/Akt were the mechanisms that mediated this effect. Further, GNL treatment upregulated Nrf2 and HO-1 to reduce oxidative stress and apoptosis. This was confirmed using 99mTc-HMPAO brain flow gamma bioassays. Thus, our data suggested GNL as a promising agent for treating neuroinflammation-induced cognitive impairment.

Ningxin-Tongyu-Zishen formula alleviates the senescence of granulosa cells on D-galactose-induced premature ovarian insufficiency mice.

Ningxin-Tongyu-Zishen formula (NTZF) is a clinical experience formula for the treatment of premature ovarian insufficiency (POI) in traditional Chinese medicine (TCM), and the potential mechanism is unknown. For in vivo experiments, POI mouse models (C57BL/6 mice), were constructed by subcutaneous injection of D-galactose (D-gal, 200 mg/kg). After treatment of NTZF (10.14, 20.27, 40.54 g/kg;) or estradiol valerate (0.15 mg/kg), ovarian function, oxidative stress (OS) and protein expression of Sirt1/p53 were evaluated. For in vitro experiments, H2O2 (200 µM) was used to treat KGN to construct ovarian granulosa cells (OGCs) cell senescence model. Pretreatment with NTZF (1.06 mg/mL) or p53 inhibitor (Pifithrin-α, 1 µM) was performed before induction of senescence, and further evaluated the cell senescence, OS, mRNA and protein expression of Sirt1/p53. In vivo, NTZF improved ovarian function, alleviated OS and Sirt1/p53 signaling abnormalities in POI mice. In vitro experiments showed that NTZF reduced the level of OS and alleviated the senescence of H2O2-induced KGN. In addition, NTZF activated the protein expression of Sirt1, inhibited the mRNA transcription and protein expression of p53 and p21. Alleviating OGCs senescence and protecting ovarian function through Sirt1/p53 is one of the potential mechanisms of NTZF in the treatment of POI.

Coconut oil ameliorates behavioral and biochemical alterations induced by D-GAL/AlCl3 in rats.

Alzheimer's disease (AD) is a chronic, progressive neurodegenerative condition marked by cognitive impairment. Although coconut oil has been shown to be potentially beneficial in reducing AD-related cognitive deficits, information on its mechanism of action is limited. Thus, we investigated the effects of coconut oil on spatial cognitive ability and non-cognitive functions in a rat model of AD induced by G-galactose (D-GAL) and aluminum chloride (AlCl3), and examined the changes in synaptic transmission, cholinergic activity, neurotrophic factors and oxidative stress in this process. The AD model was established by administering D-GAL and AlCl3 for 90 days, while also supplementing with coconut oil during this time. Cognitive and non-cognitive abilities of the rats were evaluated at the end of the 90-day supplementation period. In addition, biochemical markers related to the pathogenesis of the AD were measures in the hippocampus tissue. Exposure to D-GAL/AlCl3 resulted in a reduction in locomotor activity, an elevation in anxiety-like behavior, and an impairment of spatial learning and memory (P < 0.05). The aforementioned behavioral disturbances were observed to coincide with increased oxidative stress and cholinergic impairment, as well as reduced synaptic transmission and levels of neurotrophins in the hippocampus (P < 0.05). Interestingly, treatment with coconut oil attenuated all the neuropathological changes mentioned above (P < 0.05). These findings suggest that coconut oil shows protective effects against cognitive and non-cognitive impairment, AD pathology markers, oxidative stress, synaptic transmission, and cholinergic function in a D-GAL/AlCl3-induced AD rat model.

Evaluation of Nootropic Potential of Aerva persica Roots against D-galactose-induced Memory Impairment.

BACKGROUND: The primary phytoconstituents reported to have neuroprotective effects are flavonoids and phenolic compounds. Aerva persica roots are reported to be rich in flavonoids and phenolic compounds. Therefore, this study aimed to explore the nootropic potential of Aerva persica roots. OBJECTIVE: The objective of this study was to evaluate the nootropic potential of Aerva persica roots against D-galactose-induced memory impairment. METHODS: In this study, the roots of Aerva persica were extracted with 70% ethanol. The obtained extract was evaluated for total phenolic content using the Folin-Ciocalteu method and total flavonoid content using the aluminium chloride colorimetric assay. Afterward, the acute oral toxicity of the extract was determined following the Organisation for Economic Co-operation and Development (OECD) guideline 423. Additionally, two doses of Aerva persica (100 and 200 mg/kg body weight (BW)) were evaluated for their nootropic potential against D-galactose-induced memory impairment. The nootropic potential of the crude extract was assessed through a behavioural study and brain neurochemical analysis. Behavioural studies involved the evaluation of spatial reference- working memory using the radial arm maze test and the Y-maze test. Neurochemical analysis was performed to determine the brain's acetylcholine, acetylcholinesterase, glutathione (GSH), and malondialdehyde (MDA) levels. RESULTS: The total phenolic content and total flavonoid content were found to be 179.14 ± 2.08 µg GAE/mg and 273.72 ± 3.94 µg QE/mg, respectively. The Aerva persica extract was found to be safe up to 2000 mg/kg BW. Following the safety assessment, the experimental mice received various treatments for 14 days. The behavioural analysis using the radial maze test showed that the extract at both doses significantly improved spatial reference-working memory and reduced the number of total errors compared to disease control groups. Similarly, in the Y-maze test, both doses significantly increased the alteration percentage and the percentage of novel arm entry (both indicative of intact spatial memory) compared to disease control. In neurochemical analysis, Aerva persica at 200 mg/kg significantly normalised the acetylcholine level (p<0.0001) and GSH level (p<0.01) compared to disease control. However, the same effect was not observed with Aerva persica at 100 mg/kg. Additionally, Aerva persica at 200mg/kg BW significantly decreased the acetylcholinesterase level (p<0.0001) and decreased the brain's MDA level (p<0.01) compared to the disease control, whereas the effect of Aerva persica at 100 mg/kg BW in reducing acetylcholinesterase was non-significant. CONCLUSION: Based on the results, it can be concluded that the nootropic potential of Aerva persica was comparable to that of the standard drug, Donepezil, and the effect might be attributed to the higher content of flavonoids and phenolic compounds.

Purpurin ameliorates D-galactose-induced aging phenotypes in mouse hippocampus by reducing inflammatory responses.

Purpurin, an anthraquinone, has potent anti-oxidant and anti-inflammatory effects in various types of brain damage. In a previous study, we showed that purpurin exerts neuroprotective effects against oxidative and ischemic damage by reducing pro-inflammatory cytokines. In the present study, we investigated the effects of purpurin against D-galactose-induced aging phenotypes in mice. Exposure to 100 mM D-galactose significantly decreased cell viability in HT22 cells, and purpurin treatment significantly ameliorated the reduction of cell viability, formation of reactive oxygen species, and lipid peroxidation in a concentration-dependent manner. Treatment with 6 mg/kg purpurin significantly improved D-galactose-induced memory impairment in the Morris water maze test in C57BL/6 mice and alleviated the reduction of proliferating cells and neuroblasts in the subgranular zone of the dentate gyrus. In addition, purpurin treatment significantly mitigated D-galactose-induced changes of microglial morphology in the mouse hippocampus and the release of pro-inflammatory cytokines such as interleukin-1ß, interleukin-6, and tumor necrosis factor-α. In addition, purpurin treatment significantly ameliorated D-galactose-induced phosphorylation of c-Jun N-terminal kinase and cleavage of caspase-3 in HT22 cells. These results suggest that purpurin can delay aging by reducing the inflammatory cascade and phosphorylation of the c-Jun N-terminal in the hippocampus.

miRNA-124 alleviated memory impairment induced by d-galactose rapidly in male rats via microglia polarization.

MiRNA-124 has been considered to play a significant role in the formation of memory and a variety of neurodegenerative diseases. In this study, the aim is to verify whether miRNA-124 is involved in memory impairment induced by d-galactose, and explore the underlying neuroprotective mechanism. The results revealed that rapid administration of d-galactose (1000 mg/kg subcutaneously) in mice caused memory impairments, as determined by Novel Object Recognition test, Morris Water Maze test, and histological assessments. MiRNA-124 agomir is stereotactic injected into hippocampus, thus alleviated memory impairment induced by d-galactose and reversed the neural damage and neuroinflammation. Furthermore, the results of molecular biological analysis and immunohistochemistry revealed that miRNA-124 markedly reduced neuroinflammation induced by d-galactose through polarization of microglia as determined by detection of ionized calcium binding adapter molecule 1 (Iba-1), inducible nitric oxide synthase (iNOS) and arginase-1(Arg-1), which also downregulated inflammatory mediators, including interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), and upregulated IL-4 and IL-10. Hence, taken together, the results of the present study suggested that miRNA-124 showed a significant negative correlation with memory impairment and neuroinflammation induced by d-galactose rapidly, possibly via polarization of microglia from M1 to M2. It is possible that miRNA-124 can be used as a new target for the pathogenesis of memory impairment, including age-associated neurodegenerative diseases such as Alzheimer's disease.

5-Methyltetrahydrofolate Alleviates Memory Impairment in a Rat Model of Alzheimer's Disease Induced by D-Galactose and Aluminum Chloride.

The effects of 5-methyltetrahydrofolate (5-MTHF) on a rat model of Alzheimer's disease (AD) induced by D-galactose (D-gal) and aluminum chloride (AlCl3) were investigated. Wistar rats were given an i.p. injection of 60 mg/kg D-gal and 10 mg/kg AlCl3 to induce AD and three doses of 1 mg/kg, 5 mg/kg or 10 mg/kg 5-MTHF by oral gavage. A positive control group was treated with 1 mg/kg donepezil by gavage. Morris water maze performance showed that 5 and 10 mg/kg 5-MTHF significantly decreased escape latency and increased the number of platform crossings and time spent in the target quadrant for AD rats. The administration of 10 mg/kg 5-MTHF decreased the brain content of amyloid ß-protein 1-42 (Aß1-42) and phosphorylated Tau protein (p-Tau) and decreased acetylcholinesterase and nitric oxide synthase activities. Superoxide dismutase activity, vascular endothelial growth factor level and glutamate concentration were increased, and malondialdehyde, endothelin-1, interleukin-6, tumor necrosis factor-alpha and nitric oxide decreased. The administration of 10 mg/kg 5-MTHF also increased the expression of disintegrin and metallopeptidase domain 10 mRNA and decreased the expression of ß-site amyloid precursor protein cleavage enzyme 1 mRNA. In summary, 5-MTHF alleviates memory impairment in a D-gal- and AlCl3-exposed rat model of AD. The inhibition of Aß1-42 and p-Tau release, reduced oxidative stress, the regulation of amyloid precursor protein processing and the release of excitatory amino acids and cytokines may be responsible.

Adenosine protects D-galactose induced alterations in rat model of aging via attenuating neurochemical profile and redox status.

Aging is the process that every organism faces. The aging model of brain has been developed by the use of d-galactose (d-Gal). Adenosine (Ad) being a neuroprotective agent that has been utilized in treatment of various neurological disorders. The aim of current study is to evaluate the outcome of Ad on d-Gal induced neurotoxicity which caused behavioral deficits, memory impairment and oxidative stress. Rats were treated with d-Gal at a dose of 300 mg/ml/kg and Ad 1 mg/ml/kg; intraperitoneally for 28 days. Behavioral assessment was performed after the treatment period. Animals were sacrificed after behavioral tests and their brains were collected, hippocampus were removed for biochemical and neurochemical analysis. The results showed that administration of Ad ameliorates the negative effects of d-Gal induced aging in various behavioral tests and increased the time spent in the open arm and light box in elevated plus maze (EPM) and light dark activity (LDA) tests respectively indicate anxiolytic effect; increased the mobility time in tail suspension test (TST) shows antidepressant effect; decreased escape latencies in Morris water maze (MWM) acquisition trials, increase entries and time spent in the target quadrant suggests improvement in learning ability of animals. Administration of Ad also decreased malondialdehyde (MDA) levels, increased antioxidant enzymes activity; decreased acetylcholinesterase (AChE) activity, increased 5-hydroxytryptamine (5-HT, serotonin) metabolism and normalized histopathological alteration in the hippocampus. It is concluded that anxiety, depression and memory impairment induced by d-Gal were protected by Ad through its antioxidant and neuro-modulatory effects.

Ganoderma tsugae prevents cognitive impairment and attenuates oxidative damage in d-galactose-induced aging in the rat brain.

Lingzhi has long been regarded as having life-prolonging effects. Research in recent years has also reported that Lingzhi possesses anti-tumor, anti-inflammatory, immunomodulatory, hepatoprotective, and anti-lipogenic effects. The D-galactose (D-gal, 100 mg/kg/day)-induced aging Long-Evans rats were simultaneously orally administered a DMSO extract of Ganoderma tsugae (GTDE, 200 µg/kg/day) for 25 weeks to investigate the effects of GTDE on oxidative stress and memory deficits in the D-galactose-induced aging rats. We found that GTDE significantly improved the locomotion and spatial memory and learning in the aging rats. GTDE alleviated the aging-induced reduction of dendritic branching in neurons of the hippocampus and cerebral cortex. Immunoblotting revealed a significant increase in the protein expression levels of the superoxide dismutase-1 (SOD-1) and catalase, and the brain-derived neurotrophic factor (BDNF) in rats that received GTDE. D-gal-induced increase in the lipid peroxidation product 4-hydroxynonenal (4-HNE) was significantly attenuated after the administration of GTDE, and pyrin domain-containing 3 protein (NLRP3) revealed a significant decrease in NLRP3 expression after GTDE administration. Lastly, GTDE significantly reduced the advanced glycosylation end products (AGEs). In conclusion, GTDE increases antioxidant capacity and BDNF expression of the brain, protects the dendritic structure of neurons, and reduces aging-induced neuronal damage, thereby attenuating cognitive impairment caused by aging.

Mechanistic Insights into Ameliorating Effect of Geraniol on D-Galactose Induced Memory Impairment in Rats.

Geraniol (GE), an important ingredient in several essential oils, displayed pleiotropic biological activities through targeting multiple signaling cascades. In the current study, we aimed to examine the protective effect of GE on D-galactose (D-gal) induced cognitive impairment and explore the underlying mechanisms. Forty male Wistar rats (8 weeks old) were randomly categorized into 4 groups; Group I (saline + vehicle [edible oil]), group II (saline + geraniol) (100 mg/kg/day orally), group III (D-galactose) (100 mg/kg/day subcutaneously injected), and group IV (D-galactose + geraniol). Behavioral impairments were evaluated. Brain levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD) and acetylcholinesterase (AchE) activities were estimated. The levels of inflammatory markers [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, IL-6, and nuclear factor kappa beta (NF-kß)], endoplasmic reticulum stress sensors [inositol requiring protein 1(IRE1) and protein kinase RNA-like endoplasmic reticulum kinase (PERK)], brain-derived neurotrophic factor (BDNF), and mitogen-activated protein kinases (MAPK) pathway were measured by ELISA. Also, hippocampal histopathological assessment and immunohistochemical analysis of glial fibrillary acidic protein (GFAP) and caspase-3 were performed. Glucose regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) mRNA expression and protein levels were assessed. GE effectively ameliorated aging-related memory impairment through increasing GSH, BDNF, Ach levels, and SOD activity. Additionally, GE treatment caused a decrease in the levels of MDA, inflammatory mediators, and ER stress sensors as well as the AchE activity together with concomitant down-regulation of GRP78 and CHOP mRNA expression. Moreover, GE improved neuronal architecture and rat's spatial memory; this is evidenced by the shortened escape latency and increased platform crossing number. Therefore, GE offers a unique pharmacological approach for aging-associated neurodegenerative disorders.

Sodium arsenite accelerates D-galactose-induced aging in the testis of the rat: Evidence for mitochondrial oxidative damage, NF-kB, JNK, and apoptosis pathways.

Aging inhibits male reproductive function and can have an impact on fertility. This study elucidated the accelerating role of sodium arsenite (As3+) on D-galactose-induced reproductive aging in male rats. The rats in the study are divided into nine groups. Group I is young control. Group II is naturally aged 24-month-old rats, other animal groups received As3+ (0.5, 1, and 2 mg/kg/day, i.p.) and/or D-galactose (DG) (50 mg/kg/day, i.p.) for 8 weeks. Then, sperm parameters, histopathological manifestations, oxidative stress markers, and gene expression of inflammatory factors (TNF-α, IL-6, and NF-ƙB), apoptosis-related genes (Bcl-2 and Bax), and C-Jun N-terminal kinase (JNK) were evaluated in testis tissue. As3+ (1 and 2 mg/kg) induced significant changes in evaluated factors compared to control group. Co-treatment with DG and As3+ caused morphological changes as well as a significant decrease in sperm motility and count. In DG + As3+ group, histopathological changes were also more obvious. Moreover, as compared to the DG group, co-treated animals exhibited a significant increase in oxidant markers and a decrease in antioxidant levels. Accordingly, DG co-exposure with As3+ markedly enhances the expressions of TNF-α, IL-6, and NF-ƙB compared to DG alone. Likewise, in the testis of rats treated with As3 + plus DG compared to DG alone, there was up-regulation of Bax (pro-apoptotic), down-regulation of Bcl-2 (anti-apoptotic), and elevation of JNK expression. These findings suggest sodium arsenite as an accelerating cause for D-galactose-induced aging process in testis tissue.

Candesartan protects against d-galactose induced - Neurotoxicity and memory deficit via modulation of autophagy and oxidative stress.

PURPOSE: d-galactose induces neuroinflammation and memory deficit via oxidative stress. Candesartan is an angiotensin II-receptor blocker and has proved neuroprotective properties. This study aimed to investigate the neuroprotective effect of candesartan against d-galactose induced neuroinflammation and memory deficit via autophagy. METHODS: Twenty-eight male Wistar rats aged 3 months were divided into four equal groups: control (vehicle), d-gal (100 mg/kg d-galactose), cand (1 mg/kg candesartan), and cand+d-gal (100 mg/kg d-galactose & 1 mg/kg candesartan). All treatments were given orally and daily for 4 weeks. Assessment of memory was done using Morris water maze (MWM) test. Brain tissue was assessed for malondialdehyde (MDA), total thiol, catalase activity, glial fibrillary acidic protein (GFAP) and gene expression of TNF-α, GDNF-1 as well as autophagy genes (Beclin 1 and ATG 5). RESULTS: Prophylactic treatment of candesartan in d-galactose-treated rats significantly (p < 0.001) reduced oxidative stress via reduction of MDA as well as elevation of catalase activity and total thiol levels. Additionally, candesartan prophylactic treatment significantly increased gene expression of GDNF-1 and decreased gene expression of TNF-α. Furthermore, candesartan significantly increased the expression of autophagy related gene (Beclin 1 and ATG 5) in cand+d-gal treated rats. These results were supported by the histopathological findings which showed that candesartan prevented the neuronal injury in the cerebral cortex and hippocampus and decreased GFAP positive cells of the d-galactose-treated rats. Moreover, MWM test showed that candesartan significantly improved memory deficit in cand+d-gal treated rats. CONCLUSION: Candesartan prevents d-galactose-induced neurotoxicity and memory deficit via activating autophagy and decreasing oxidative stress. Therefore, candesartan was a good candidate for age-related neurodegenerative disorders and memory deficit.

Inhibition of mitochondrial pyruvate carrier 1 by lapatinib ditosylate mitigates Alzheimer's-like disease in D-galactose/ovariectomized rats.

Mitochondrial, autophagic impairment, excitotoxicity, and also neuroinflammation are implicated in Alzheimer's disease (AD) pathophysiology. We postulated that inhibiting the mitochondrial pyruvate carrier-1 (MPC-1), which inhibits the activation of the mammalian target of rapamycin (mTOR), may ameliorate the neurodegeneration of hippocampal neurons in the rat AD model. To assess this, we used lapatinib ditosylate (LAP), an anti-cancer drug that inhibits MPC-1 through suppression of estrogen-related receptor-alpha (ERR-α), in D-galactose/ovariectomized rats. AD characteristics were developed in ovariectomized (OVX) rats following an 8-week injection of D-galactose (D-gal) (150 mg/kg, i.p.). The human epidermal growth factor receptor-2 (HER-2) inhibitor, LAP (100 mg/kg, p.o.) was daily administered for 3 weeks. LAP protected against D-gal/OVX-induced changes in cortical and hippocampal neurons along with improvement in learning and memory, as affirmed using Morris water maze (MWM) and novel object recognition (NOR) tests. Furthermore, LAP suppressed the hippocampal expression of Aß1-42, p-tau, HER-2, p-mTOR, GluR-II, TNF-α, P38-MAPK, NOX-1, ERR-α, and MPC-1. Also, LAP treatment leads to activation of the pro-survival PI3K/Akt pathway. As an epilogue, targeting MPC-1 in the D-gal-induced AD in OVX rats resulted in the enhancement of autophagy, and suppression of neuroinflammation and excitotoxicity. Our work proves that alterations in metabolic signaling as a result of inhibiting MPC-1 were anti-inflammatory and neuroprotective in the AD model, revealing that HER-2, MPC-1, and ERR-α may be promising therapeutic targets for AD.

Effects and Mechanisms of Synaptotagmin-7 in the Hippocampus on Cognitive Impairment in Aging Mice.

Aging is an irreversible biological process that involves oxidative stress, neuroinflammation, and apoptosis, and eventually leads to cognitive dysfunction. However, the underlying mechanisms are not fully understood. In this study, we investigated the role and potential mechanisms of Synaptotagmin-7, a calcium membrane transporter in cognitive impairment in aging mice. Our results indicated that Synaptotagmin-7 expression significantly decreased in the hippocampus of D-galactose-induced or naturally aging mice when compared with healthy controls, as detected by western blot and quantitative reverse transcriptase-polymerase chain reaction analysis. Synaptotagmin-7 overexpression in the dorsal CA1 of the hippocampus reversed long-term potentiation and improved hippocampus-dependent spatial learning in D-galactose-induced aging mice. Synaptotagmin-7 overexpression also led to fully preserved learning and memory in 6-month-old mice. Mechanistically, we demonstrated that Synaptotagmin-7 improved learning and memory by elevating the level of fEPSP and downregulating the expression of aging-related genes such as p53 and p16. The results of our study provide new insights into the role of Synaptotagmin-7 in improving neuronal function and overcoming memory impairment caused by aging, suggesting that Synaptotagmin-7 overexpression may be an innovative therapeutic strategy for treating cognitive impairment.

Astilbin ameliorates oxidative stress and apoptosis in D-galactose-induced senescence by regulating the PI3K/Akt/m-TOR signaling pathway in the brains of mice.

An increasing amount of evidence has shown that injection of D-galactose (D-gal) can mimic natural aging that typically is associated with brain injury. Oxidative stress and apoptosis has been shown to play an essential role in aging process. The purpose of this study was to investigate the protective effectsof astilbin (ASB) on D-Gal-induced agingin miceand to further explore the underlying mechanisms. We randomly divided 50 mice into 5 groups.To establish this model of aging, 40micewere intraperitoneally administered D-Gal (500 mg/kg). The mice in the treatmentgroupswere intragastricaly administratedASB at doses of 40 and 80 mg/kg. H&E and TUNEL staining were used to determine the effect of ASB on the number of apoptotic cells in the brain. Furthermore, biochemical indices of serum, oxidative stress factors, and apoptosis factors were determined to clarify the underlying mechanism using reagent test kits and western blotting. The results showed that varying doses of ASB could improve D-Gal-induced histopathological damageand significantly alleviatedthe aging induced by D-Galin mice. ASB remarkably decreased the activities of malondialdehyde (MDA)(p < 0.01)and Acetyl cholinesterase (AChE)(p < 0.05) and markedlyincreased the content of catalase (CAT)(p < 0.01)and superoxide dismutase (SOD)(p < 0.01), respectively. In addition, Western blotting revealed thatASB treatment (40 mg/kg)attenuated the D-gal-induced Bax and Caspase 3 protein expression(p < 0.01) and reversed the increase in Bcl-2protein expressionin brain. Moreover, ASB treatment significantly upregulated the protein expression ofp-PI3K/PI3K and altered the p-Akt/Akt ratio (p < 0.05), while inhibiting the expression of p-m-TOR relative to m-TOR(p < 0.05). Moreover, the expression of P53 tended to decreasein the low ASB treatmentgroup (40 mg/kg), whereas no change was observed in the high ASB treatmentgroup (80 mg/kg). In the intestinal flora, the richness of the normal group and the ASB group was higher than that of the D-Gal group. Heat map analysis also showed that ASB promoted Lactobacillus and other probiotics and also confirmed the advantages of ASB. The observed changes in intestinal flora further verified the efficacy of ASB.

Resveratrol, a novel inhibitor of GLUT9, ameliorates liver and kidney injuries in a D-galactose-induced ageing mouse model via the regulation of uric acid metabolism.

Accumulating evidence has shown that chronic injection of D-galactose (D-gal) can mimic natural ageing and induce liver and kidney injury. Previous studies showed that D-gal increased uric acid (UA) levels in mice. The increase in UA levels caused inflammation, accelerated oxidative stress, and aggravated liver and kidney injury. Oxidative stress and inflammation play vital roles in the ageing process. Therefore, reducing the levels of UA in ageing mice improved liver and kidney injury. Glucose transporter 9 (GLUT9) is responsible for the reabsorption of UA in the body, and its inhibition helps downregulate UA levels. The present study investigated the UA-lowering activity of the GLUT9 inhibitor resveratrol (RSV) using the patch clamping technique established in our laboratory in vitro. This research is the first study to demonstrate that RSV effectively inhibits UA uptake via GLUT9 (IC50 = 68.77 µM) in vitro. An in vivo study was also performed to investigate the possible protective effect of RSV on D-gal-induced liver and kidney injury. RSV significantly reduced serum UA levels via the downregulation of GLUT9 mRNA and protein expression and promoted the excretion of excess UA through urine. Biochemical analysis showed that RSV significantly downregulated abnormal increases in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine (CRE) caused by long-term D-gal treatment, which effectively improved pathological damage, increased superoxide dismutase (SOD) activity and decreased the content of malondialdehyde (MDA) in the liver and kidneys. RSV also downregulated the expression of the inflammatory cytokines, interleukin IL-6, IL-1ß and tumor necrosis factor (TNF)-α in the liver and kidneys of ageing mice. Our findings provide new insights into the treatment strategies for ageing-induced liver and kidney injury and reveal a new mechanism of RSV-induced reduction in UA levels in ageing individuals.

Chitotriosidase attenuates brain inflammation via HDAC3/NF-κB pathway in D-galactose and aluminum-induced rat model with cognitive impairments.

Chitotriosidase (CHIT1, chitinase 1) is increased in the cerebrospinal fluid and peripheral blood of Alzheimer's disease (AD) patients. Our previous study has shown that CHIT1 provides potential protection through microglial polarization and reduction of ß-amyloid (Aß) oligomers on rat models of AD. Histone deacetylase 3 (HDAC3) plays a significant role in the expression and regulation of proteins related to the pathophysiology of AD. In addition, nuclear factor-kappa B (NF-κB) signaling pathway activation in neurons is associated with the progression of AD. NF-κB activation is regulated by HDAC3 deacetylation. In the present study, we researched the role of CHIT1 in HDAC3/NF-κB signaling in D-galactose (D-gal) and aluminum-exposed rat model with cognitive impairments. Following CHIT1 treatment, we found that the protein and mRNA levels of HDAC3 and NF-κB were reduced, the expression level of IκBα increased, anti-inflammatory factors (Arg-1, IL-10, and CD206) were elevated while pro-inflammatory factors (TNF-a, iNOS, and IL-1ß) were decreased in D-gal/aluminum-induced AD rats. These results indicate that CHIT1 can regulate brain inflammation via HDAC3/NF-κB p65 pathway, contributing to improvement of cognitive impairment.

Protective effect against d-gal-induced aging mice and components of polypeptides and polyphenols in defatted walnut kernel during simulated gastrointestinal digestion.

Defatted walnut kernel with pellicle (WKP) is an industrial byproduct during walnut oil extraction, which is rich in protein and polyphenols. WKP was hydrolyzed by simulated gastrointestinal digestion to obtain WKP hydrolysates (WKPHs). Results showed the protein recovery and hydrolysis degree of WKPH were 82.15 and 10.36%. The total phenol contents in WKP and WKPH were 4.90 and 40.70 mg gallic acid equivalent/g, respectively. The antiaging activity of WKPH was evaluated using a d-gal-induced aging mouse model. Results showed that WKPHs could recover the activities of SOD and T-AOC and the content of MDA in tissues and serum of the aging mice. The histological morphology of liver and kidney sections and the immunohistochemistry of TNF-α, IL-1ß, and IL-6 in liver were observed. WKPH could effectively protect the tissue structure of the liver and kidney and reduce the inflammatory expression of liver in aging mice. The polypeptides and polyphenols in WKPH were further analyzed. Fifty polypeptides were identified and 12 of these peptides had Leu-Arg at the C-terminal. Forty-two polyphenols were detected, and most phenolic compounds belonged to ellagitannins. This study provided a theoretical basis for the improved processing and high-value utilization of walnut byproducts. PRACTICAL APPLICATION: Defatted walnut kernel with pellicle was hydrolyzed by simulated gastrointestinal digestion to obtain its hydrolysates. The hydrolysates have good antiaging activity in vivo. Fifty polypeptides were identified and 12 of these peptides had Leu-Arg at the C-terminal. Forty-two polyphenols were detected, and most phenolic compounds belonged to ellagitannins. This study could provide a theoretical basis for high-value utilization of walnut byproducts.