Mouse Model Of Aging Research Articles

Neuronal cell cycle reentry events in the aging brain are more prevalent in neurodegeneration and lead to cellular senescence.

Increasing evidence indicates that terminally differentiated neurons in the brain may recommit to a cell cycle-like process during neuronal aging and under disease conditions. Because of the rare existence and random localization of these cells in the brain, their molecular profiles and disease-specific heterogeneities remain unclear. Through a bioinformatics approach that allows integrated analyses of multiple single-nucleus transcriptome datasets from human brain samples, these rare cell populations were identified and selected for further characterization. Our analyses indicated that these cell cycle-related events occur predominantly in excitatory neurons and that cellular senescence is likely their immediate terminal fate. Quantitatively, the number of cell cycle re-engaging and senescent neurons decreased during the normal brain aging process, but in the context of late-onset Alzheimer's disease (AD), these cells accumulate instead. Transcriptomic profiling of these cells suggested that disease-specific differences were predominantly tied to the early stage of the senescence process, revealing that these cells presented more proinflammatory, metabolically deregulated, and pathology-associated signatures in disease-affected brains. Similarly, these general features of cell cycle re-engaging neurons were also observed in a subpopulation of dopaminergic neurons identified in the Parkinson's disease (PD)-Lewy body dementia (LBD) model. An extended analysis conducted in a mouse model of brain aging further validated the ability of this bioinformatics approach to determine the robust relationship between the cell cycle and senescence processes in neurons in this cross-species setting.

The impact of continuous and intermittent ketogenic diets on cognitive behavior, motor function, and blood lipids in TgF344-AD rats.

Studies suggest that ketogenic diets (KD) may improve memory in mouse models of aging and Alzheimer's disease (AD). This study determined whether a continuous or intermittent KD (IKD) enhanced cognitive behavior in the TgF344-AD rat model of AD. At 6 months-old, TgF344-AD and wild-type (WT) littermates were placed on a control (CD), KD, or IKD (morning CD and afternoon KD) provided as two meals per day for 2 or 6 months. Cognitive and motor behavior and circulating β-hydroxybutyrate (BHB), AD biomarkers and blood lipids were assessed. Animals on a KD diet had elevated circulating BHB, with IKD levels intermediate to CD and KD. TgF344-AD rats displayed impaired spatial learning memory in the Barnes maze at 8 and 12 months of age and impaired motor coordination at 12 months of age. Neither KD nor IKD improved performance compared to CD. At 12 months of age, TgF344-AD animals had elevated blood lipids. IKD reduced lipids to WT levels with KD further reducing cholesterol below WT levels. This study shows that at 8 or 12 months of age, KD or IKD intervention did not improve measures of cognitive or motor behavior in TgF344-AD rats; however, both IKD and KD positively impacted circulating lipids.

Mechanism Explanation on Improved Cognitive Ability of D-Gal Inducing Aged Mice Model by Lactiplantibacillus plantarum MWFLp-182 via the Microbiota-Gut-Brain Axis.

Gut microbiota can influence cognitive ability via the gut-brain axis. Lactiplantibacillus plantarum MWFLp-182 (L. plantarum MWFLp-182) was obtained from feces of long-living individuals and could exert marked antioxidant ability. Interestingly, this strain reduced the D-galactose-induced impaired cognitive ability in BALB/c mice. To comprehensively elucidate the underlying mechanism, we evaluated the colonization, antioxidant, and anti-inflammatory activities of L. plantarum MWFLp-182, along with the expression of potential genes associated with cognitive ability influenced and gut microbiota. L. plantarum MWFLp-182 enhanced the expression of anti-inflammatory cytokines, reduced the expression of proinflammatory cytokines, and increased tight junction protein expression in the colon. Moreover, L. plantarum MWFLp-182 could modify the gut microbiota. Notably, treatment with L. plantarum MWFLp-182 upregulated the expression of postsynaptic density protein-95, nuclear factor erythroid 2-related factor, nerve growth factor, superoxide dismutase, and brain-derived neurotrophic factor/neuronal nuclei, while downregulating the expression of bcl-2-associated X and malondialdehyde in the hippocampus and upregulating short-chain fatty acids against D-galactose-induced mouse brain deficits. Accordingly, L. plantarum MWFLp-182 could improve cognitive ability in a D-galactose-inducing mouse model.

The polysaccharides from Balanophora polyandra enhanced neuronal autophagy to ameliorate brain function decline in natural aging mice through the PI3K/AKT/mTOR signaling pathway.

The decline of aging brain neurons is the main cause of various neurodegenerative disease. This study aimed to examine the impact of Balanophora polyandra polysaccharides (BPP) against aging related neuronal deterioration. C57BL/6 mice were fed with regular feed for 27 months to establish a natural aging mouse model. From 3 months of age, mice in the drug-treated group were respectively fed with feed containing 0.05 or 0.18% BPP until 27 months of age. The effects of BPP treatment on the pathological changes of neurons in mice brain were evaluated, as well as autophagy-related and signaling pathway proteins. BPP treatment had a notable positive impact on the pathological injury of cortical and hippocampal neurons, alleviated neuronal degeneration, and enhanced the staining of Nissl bodies in natural aging mice. Furthermore, BPP upregulated autophagy-related proteins LC3 II/I, Parkin, and PINK1 in the cortex and hippocampus of aging mice, and significantly decreased the expression of p62, PI3K, p-protein Kinase B (AKT), and p-mTOR. Immunofluorescence results showed a reduction in the brightness of LC3, which mainly coexpressed with NeuN in natural aging mice brain, and increased LC3-positive neurons were observed after BPP treatment. Collectively, BPP treatment enhanced neuronal autophagy to improve brain functional degradation through the PI3K/AKT/mTOR signaling in natural aging mice. These finding suggested that BPP has potential to mitigate or delay the neurodegeneration associated with aging and further investigation was needed to validate its efficacy in elderly populations.

Design and preparation of NMN nanoparticles based on protein-marine polysaccharide with increased NAD+ level in D-galactose induced aging mice model

Nicotinamide mononucleotide (NMN) is being investigated for its ability to address the decline in NAD+ level during aging. This study aimed to construct a delivery system based on ovalbumin and fucoidan nanoparticles to ameliorate the bioaccessibility of NMN by increasing NAD+ level in aging mouse model. The NMN-loaded ovalbumin and fucoidan nanoparticles (OFNPs) were about 177 nm formed by the interplay of hydrogen bonds between ovalbumin and fucoidan. Compared with free NMN, NMN-loaded OFNPs intervention could obviously improve the antioxidant enzyme activity of senescent cell induced by D-galactose. The NMN-loaded OFNPs treatment could ameliorate the loss of weight and organ index induced by senescence, and maintain the water content for the aging mice. The Morris maze test indicated that hitting blind side frequency and escape time of NMN-loaded OFNPs group decreased by 13% and 35% compared with that of free NMN group. Furthermore, the NMN-loaded OFNPs significantly alleviated the age-related oxidative stress and increased the generation of NAD+ 1.34 times by improving the bioaccessibility of NMN. Our data in this study supplied a strategy to enhance the bioavailability of NMN in senescence treatment.

Efficacy and safety of mesenchymal stem cell therapy for ovarian ageing in a mouse model

BackgroundOvarian ageing is one of the major issues that impacts female fertility. Mesenchymal stem cell (MSC)-based therapy has made impressive progress in recent years. However, the efficacy and safety of MSCs, as nonautologous components, remain to be further verified.MethodsTwo common sources of MSCs, umbilical cord-derived MSCs (UC-MSCs) and adipose tissue-derived MSCs (AD-MSCs), were orthotopically transplanted into a mouse model of ovarian ageing to evaluate their therapeutic effects. The safety of the treatment was further evaluated, and RNA sequencing was performed to explore the underlying mechanisms involved.ResultsAfter orthotopic transplantation of MSCs into the ovary, the oestrous cycle, ovarian weight, number and proportion of primary follicles, granulosa cell proliferation, and angiogenesis were improved. The effects of AD-MSCs were superior to those of UC-MSCs in several indices, such as post-transplant granulosa cell proliferation, ovarian weight and angiogenesis. Moreover, the tumorigenesis, acute toxicity, immunogenicity and biodistribution of MSCs were evaluated, and both AD-MSCs and UC-MSCs were found to possess high safety profiles. Through RNA sequencing analysis, enhancement of the MAPK cascade was observed, and long-term effects were mainly linked to the activation of immune function.ConclusionsOrthotopic transplantation of MSCs displays significant efficacy and high safety for the treatment of ovarian ageing in mice.

Genome-wide analysis of hepatic DNA methylation reveals impact of epigenetic aging on xenobiotic metabolism and transport genes in an aged mouse model

Hepatic xenobiotic metabolism and transport decline with age, while intact xenobiotic metabolism is associated with longevity. However, few studies have examined the genome-wide impact of epigenetic aging on these processes. We used reduced representation bisulfite sequencing (RRBS) to map DNA methylation changes in liver DNA from mice ages 4 and 24 months. We identified several thousand age-associated differentially methylated sites (a-DMS), many of which overlapped genes encoding Phase I and Phase II drug metabolizing enzymes, in addition to ABC and SLC classes of transporters. Notable genes harboring a-DMS were Cyp1a2, Cyp2d9, and Abcc2 that encode orthologs of the human drug metabolizing enzymes CYP1A2 and CYP2D6, and the multidrug resistance protein 2 (MRP2) transporter. Cyp2d9 hypermethylation with age was significantly associated with reduced gene expression, while Abcc2 expression was unchanged with age. Cyp1a2 lost methylation with age while, counterintuitively, its expression also reduced with age. We hypothesized that age-related dysregulation of the hepatic transcriptional machinery caused down-regulation of genes despite age-related hypomethylation. Bioinformatic analysis of hypomethylated a-DMS in our sample found them to be highly enriched for hepatic nuclear factor 4 alpha (HNF4α) binding sites. HNF4α promotes Cyp1a2 expression and is downregulated with age, which could explain the reduction in Cyp1a2 expression. Overall, our study supports the broad impact of epigenetic aging on xenobiotic metabolism and transport. Future work should evaluate the interplay between hepatic nuclear receptor function and epigenetic aging. These results may have implications for studies of longevity and healthy aging.

Anti-aging effect and molecular mechanism of Xiyangshen Sanqi Danshen Granules based on metabolomics and bioinformatics

This study investigated the anti-aging mechanism of Xiyangshen Sanqi Danshen Granules based on metabonomics, network pharmacology, and molecular docking. The aging mice model was induced by intraperitoneal injection of D-galactose(D-gal). Mice were randomly divided into a control group, model group, melatonin group(MT group), and low, medium, and high dose groups of Xiyangshen Sanqi Danshen Granules(XSD-L, XSD-M, and XSD-H). An open-field experiment was conducted, and the expression of cell cycle arrest proteins(p16) and phosphorylated histone family 2A variant(γH2AX) in the brain tissue was detected by immunofluorescence. The expression of interleukin-1β(IL-1β) and interleukin-6(IL-6) in the brain tissue was detected by enzyme-linked immunosorbent assay(ELISA). Metabolomics analysis was performed on the serum of mice in control, model, and XSD-H groups to obtain metabolic processes and metabolites. The effective chemical components and potential targets of Xiyangshen Sanqi Danshen Granules were predicted through network pharmacology, and the network diagram of "drug-effective chemical components-key targets" was constructed. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) analysis were carried out, and a protein-protein interaction(PPI) network was constructed to clarify the anti-aging mechanism of Xiyangshen Sanqi Danshen Granules. The results showed that the Xiyangshen Sanqi Danshen Granules could significantly improve the aging degree of D-gal mice, significantly improve the total motion distance and the mean motion speed of D-gal mice, and reduce the rest time. In addition, Xiyangshen Sanqi Danshen Granules could significantly reduce the protein levels of IL-6 and IL-1β and the expression of p16 and γH2AX in D-gal mice. Compared with the model group, 66 differential metabolites(DMs) were significantly up-regulated, and 91 DMs were down-regulated in the XSD-H group. Moreover, four key metabolic pathways(tryptophan metabolism, glycerophospholipid metabolism, pyrimidine metabolism, and lysine degradation) and 16 biomarkers(lysine, tryptophan, indoleacetaldehyde, PCs, LysoPCs, 3-hydroxyanthranilic acid, melatonin, etc) were screened out. 58 main active components and 62 key targets of Xiyangshen Sanqi Danshen Granules were screened by network pharmacology. The GO functional enrichment analysis found the positive regulation of gene expression, drug response, etc. KEGG pathway enrichment screening involved diabetic complications-related AGE-RAGE signaling pathway, hypoxia inducible factor-1 signaling pathway, etc. Through the PPI network and molecular docking, six potential core targets of STAT3, MAPK1, MAPK14, EGFR, FOS, and STAT1 were screened.

Integrated Transcriptomic and Proteomic Study of the Mechanism of Action of the Novel Small-Molecule Positive Allosteric Modulator 1 in Targeting PAC1-R for the Treatment of D-Gal-Induced Aging Mice.

Small-molecule positive allosteric modulator 1 (SPAM1), which targets pituitary adenylate cyclase-activating polypeptide receptor 1 (PAC1-R), has been found to have a neuroprotective effect, and the underlying mechanism was explored in this study. First, using a D-galactose (D-gal)-induced aging mouse model, we confirmed that SPAM1 improves the structure of the hippocampal dentate gyrus and restores the number of neurons. Compared with D-gal model mice, SPAM1-treated mice showed up-regulated expression of Sirtuin 6 (SIRT6) and Lamin B1 and down-regulated expression of YinYang 1 (YY1) and p16. A similar tendency was observed in senescent RGC-5 cells induced by long-term culture, indicating that SPAM1 exhibits significant in vitro and in vivo anti-senescence activity in neurons. Then, using whole-transcriptome sequencing and proteomic analysis, we further explored the mechanism behind SPAM1's neuroprotective effects and found that SPAM is involved in the longevity-regulating pathway. Finally, the up-regulation of neurofilament light and medium polypeptides indicated by the proteomics results was further confirmed by Western blotting. These results help to lay a pharmacological network foundation for the use of SPAM1 as a potent anti-aging therapeutic drug to combat neurodegeneration with anti-senescence, neuroprotective, and nerve regeneration activity.

Characterization and anti-aging activities of polysaccharide from Rana dybowskii Guenther.

Introduction: Rana dybowskii Guenther (RDG), as a traditional Chinese medicine, has been shown to have antioxidant effects. However, studies on the anti-aging effect of RDG are still limited. Methods: In this study, we prepared polysaccharides from the skin of RDG (RDGP) by hot water extraction, alcohol precipitation, ion-exchange chromatography and gel chromatography. The proteins were removed using the Sevage method in combination with an enzymatic method. The structural features were analyzed using high-performance gel permeation chromatography, β-elimination reaction and Fourier transform infrared spectra. The anti-aging effect of RDGP was investigated by using D-Gal to establish an aging model in mice, and pathological changes in the hippocampus were observed under a microscope. Results: We obtained the crude polysaccharide DGP from the skin of RDG, with a yield of 61.8%. The free protein was then removed by the Sevage method to obtain DGPI and deproteinated by enzymatic hydrolysis combined with the Sevage method to further remove the bound protein to obtain the high-purity polysaccharide DGPII. Then, DGPIa (1.03 × 105Da) and DGPIIa (8.42 × 104Da) were obtained by gel chromatography, monosaccharide composition analysis showed that they were composed of Man, GlcA, GalNAc, Glc, Gal, Fuc with molar ratios of 1: 4.22 : 1.55: 0.18 : 8.05: 0.83 and 0.74 : 1.78: 1: 0.28: 5.37 : 0.36, respectively. The results of the β-elimination reaction indicated the presence of O-glycopeptide bonds in DGPIa. The Morris water maze test indicated that mice treated with DGPIIa exhibited a significantly shorter escape latency and increased time spent in the target quadrant as well as an increase in the number of times they traversed the platform. Pathologic damage to the hippocampus was alleviated in brain tissue stained with hematoxylin-eosin. In addition, DGPIIa enhanced the activities of SOD, CAT, and GSH-Px and inhibited the level of MDA in the serum and brain tissues of aging mice. Discussion: These results suggest that RDGP has potential as a natural antioxidant and provide useful scientific information for anti-aging research.

Effects of saponins Rb1 and Re in American ginseng combined intervention on immune system of aging model.

Aging is a major risk factor for the development of many pathological processes, such as reduced immunity, cancer, cardiovascular diseases or neurodegenerative diseases, while age-related chronic diseases are the most common causes of death. This paper studies the effects of American ginseng saponin Rb1 and Re alone and combined intervention on the immune system of aging mouse models, by using 30mg/kg Rb1, 15mg/kg Re, and Rb1 + Re (30mg/kg Rb1 and 15mg/kg Re (co-intervention) was used to intervene in the aging model, and immune indicators such as thymus index, spleen index, interleukin and interferon were detected to evaluate the impact of Rb1 and Re on immune function. The results show that Rb1 and Re intervention alone can increase the spleen index by 7%-12% and the thymus index by 12%-19% in the aging model. After Rb1 or Re alone intervened, the apoptotic cells in the thymus were slightly reduced, and the proportion of apoptotic cells was reduced. The combination of Rb1 + Re can promote the thymus index and spleen index to increase by 23.40% and 25.5% respectively, which is more advantageous than Rb1 or Re alone. In addition, Rb1 and Re intervention can reduce the level of interferon INF to a level comparable to that of young mice. Rb1 + Re can not only reduce the INF content, but also reduce the TNF content. The above results show that American ginseng saponin Rb1 and Re can delay the decline of the immune system in the aging model, and the combined intervention of the two is significantly better than individual intervention in the recovery of the immune system. This paper can provide theoretical basis and data support for the development of American ginseng nutritional supplements and its application in aging groups products to improve immunity.

TREM1 disrupts myeloid bioenergetics and cognitive function in aging and Alzheimer disease mouse models.

Human genetics implicate defective myeloid responses in the development of late-onset Alzheimer disease. A decline in peripheral and brain myeloid metabolism, triggering maladaptive immune responses, is a feature of aging. The role of TREM1, a pro-inflammatory factor, in neurodegenerative diseases is unclear. Here we show that Trem1 deficiency prevents age-dependent changes in myeloid metabolism, inflammation and hippocampal memory function in mice. Trem1 deficiency rescues age-associated declines in ribose 5-phosphate. In vitro, Trem1-deficient microglia are resistant to amyloid-β42 oligomer-induced bioenergetic changes, suggesting that amyloid-β42 oligomer stimulation disrupts homeostatic microglial metabolism and immune function via TREM1. In the 5XFAD mouse model, Trem1 haploinsufficiency prevents spatial memory loss, preserves homeostatic microglial morphology, and reduces neuritic dystrophy and changes in the disease-associated microglial transcriptomic signature. In aging APPSwe mice, Trem1 deficiency prevents hippocampal memory decline while restoring synaptic mitochondrial function and cerebral glucose uptake. In postmortem Alzheimer disease brain, TREM1 colocalizes with Iba1+ cells around amyloid plaques and its expression is associated with Alzheimer disease clinical and neuropathological severity. Our results suggest that TREM1 promotes cognitive decline in aging and in the context of amyloid pathology.

Mode of administration influences plasma levels of active Centella asiatica compounds in 5xFAD mice while markers of neuroinflammation remain unaltered.

A water extract of Centella asiatica (L.) Urban [Apiaceae] (CAW) has demonstrated cognitive-enhancing effects in mouse models of Alzheimer's disease and aging, the magnitude of which is influenced by whether CAW is delivered in the drinking water or the diet. These cognitive benefits are accompanied by improvements in oxidative stress and mitochondrial function in the brain, two pathways related to the neuroinflammatory response. The effect of CAW on neuroinflammation, however, has not been directly studied. Here, we investigated the effect of CAW on neuroinflammation in 5xFAD mice and compared plasma levels of CAW's active compounds following two modes of CAW administration. Eight-to-nine-month-old male and female 5xFAD mice and their wild-type littermates were administered CAW in their diet or drinking water (0 or 1,000 mg/kg/day) for five weeks. Immunohistochemistry was performed for β-amyloid (Aβ), glial fibrillary acidic protein (GFAP), and Griffonia simplicifolia lectin I (GSL I) in the cortex and hippocampus. Gene expression of inflammatory mediators (IL-6, TNFα, IL-1β, TREM2, AIF1, CX3CR1, CX3CL1, CD36, C3AR1, RAGE, CCR6, CD3E) was measured in the deep grey matter. CAW decreased cortical Aβ plaque burden in female 5xFAD mice administered CAW in the drinking water but had no effect on Aβ plaques in other treatment groups. CAW did not impact elevated levels of GFAP or GSL I in 5xFAD mice, regardless of sex, brain region, or mode of CAW administration. In the deep grey matter, CAW increased C3AR1 expression in 5xFAD females administered CAW in the drinking water and decreased IL-1β expression in 5xFAD males administered CAW in the diet. CAW had no effect, however, on gene expression levels of any other inflammatory mediator in the deep grey, for either sex or mode of CAW administration. Mice administered CAW in the drinking water versus the diet had significantly higher plasma levels of CAW compounds. CAW had little impact on the neuroinflammatory markers selected for evaluation in the present study, suggesting that the cognitive benefits of CAW may not be mediated by an anti-inflammatory effect or that additional molecular markers are needed to fully characterize the effect of CAW on neuroinflammation.

Abstract 6870: Immunological aging in triple negative breast cancer leads to a chronic interferon phenotype and immune cell exhaustion that impedes response to therapy

Abstract Age is the biggest risk factor for developing most forms of cancer, and understanding how age impacts cancer progression is critical to improving responses to therapy. As we age immune function declines suggesting that therapeutic responses, particularly to immunotherapies, will also change with age. Early clinical trial data suggests that there are age-associated responses to immunotherapies. Clinical trials, however, are not designed to reflect patient chronological and immunological ages - over 50% of breast cancer patients are over the age of 60, yet less than 25% of patients in clinical trials are in this age range. Here, we utilize a preclinical mouse model of immunological aging to understand how aging impacts immune responses to triple-negative breast cancer (TNBC). Immunologically young (8 weeks old) and aged (~12 months old) FVB mice were orthotopically injected with syngeneic Met1 TNBC cells. We previously established that this preclinical model mimics human immunological aging and enables us to better understand how age impacts disease progression and therapeutic responses. Once tumors became palpable, mice were treated with paclitaxel or vehicle control and/or anti-PDL1 to mimic first-line therapeutic strategies. Tumors grew significantly faster in young control mice compared to aged, but young mice had a more robust response to therapy. Notably, only young mice had a significant benefit of combo therapy (paclitaxel + anti-PDL1) over monotherapy alone. Tumors in aged mice had significantly more infiltration of CD8+ cytotoxic T cells and FOXP3+ inhibitory T-regulatory cells compared to young control mice, yet only tumors in young mice exhibited an increase in T cell infiltration with chemo or immunotherapy. Depletion of either CD8+ or CD4+ T cells in immune-competent FVB mice both led to a complete loss of age-associated differences in tumor growth. RNA sequencing analysis indicated that the infiltrating T cells in aged mice may be exhausted due to a chronic interferon phenotype, as indicated by enrichments of interferon alpha, interferon gamma, and IL2 signaling pathways, as well as expression of RIPK1, TNFa, and the immune exhaustion markers PD1, CTLA4, TIM3, and LAG3. Analysis of published single cell RNAseq data indicated the same interferon response pathways enriched with age in human TNBC, particularly in the T cell compartment. Our findings show that the aging immune microenvironment significantly impacts tumor progression and that a chronic interferon phenotype with age may lead to T cell exhaustion and impaired therapeutic responses. This work suggests that targeting interferon signaling may lead to improved therapeutic responses. Together these findings demonstrate how immunological aging can impact disease progression and response to therapy and highlight the importance of developing age-stratified treatment strategies. Citation Format: Milos Spasic, Adrienne Parsons, Gregory Goreczny, Qiuchen Guo, Abigail Recko, Elizabeth Mittendorf, Peter van Galen, Sandra McAllister. Immunological aging in triple negative breast cancer leads to a chronic interferon phenotype and immune cell exhaustion that impedes response to therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6870.

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.

MicroRNA-7 deficiency ameliorates d-galactose-induced aging in mice by regulating senescence of Kupffer cells.

Aging is intricately linked to immune system dysfunction. Recent studies have highlighted the biological function of microRNA-7 (miR-7) as a novel regulator of immune cell function and related diseases. However, the potential role of miR-7 in aging remains unexplored. Here, we investigated the contribution of miR-7 to d-gal-induced aging in mice, focusing on its regulation of senescent Kupffer cells. Our findings revealed that miR-7 deficiency significantly ameliorated the aging process, characterized by enhanced CD4+ T-cell activation. However, the adoptive transfer of miR-7-deficient CD4+T cells failed to improve the age-related phenotype. Further analysis showed that miR-7 deficiency significantly reduced IL-1β production in liver tissue, and inhibiting IL-1β invivo slowed down the aging process in mice. Notably, IL-1β is mainly produced by senescent Kupffer cells in the liver tissue of aging mice, and miR-7 expression was significantly up-regulated in these cells. Mechanistically, KLF4, a target of miR-7, was down-regulated in senescent Kupffer cells in aging mouse model. Furthermore, miR-7 deficiency also modulated the NF-κB activation and IL-1β production in senescent Kupffer cells through KLF4. In conclusion, our findings unveil the role of miR-7 in d-gal-induced aging in mice, highlighting its regulation of KLF4/NF-κB/IL-1β pathways in senescent Kupffer cells. This research may enhance our understanding of miRNA-based aging immune cells and offer new avenues for new intervention strategies in aging process.

A study on the anti-senescent effects of flavones derived from Prinsepia utilis Royle seed residue

Ethnopharmacological relevancePrinsepia utilis Royle, also known as the Anas fruit, is a unique perennial woody oil plant from Yunnan Province, China. In the ancient texts of Dongba sutras and Yunnan Southern Materia Medica, it has been documented that the local Naxi, Tibetan, and Mosuo communities extensively utilize the root and leaf fruits of green thorns for various purposes. These include treating mild-to-moderate specific dermatitis, moisturising the skin, providing protection against UV damage, aiding childbirth in pregnant women, safeguarding stomach health, reducing the risk of arteriosclerosis, and delaying aging. Aim of the studyIn this study, leftover residues from oil extraction were efficiently reused, and flavonoids were identified during subsequent extraction and separation processes. The anti-senescent effects of flavonoids in P. utilis Royle have not been systematically studied. Therefore, the objective of this study was to explore the anti-senescent properties of the flavonoids obtained from P. utilis Royle. MethodsFirst, HPLC and other analytical techniques were used to identify the components of the P. utilis Royle flavonoid (PURF). Next, DPPH, hydroxyl radicals, superoxide anion O2−, collagenase, and elastase were initially detected using in vitro biochemical assays. To examine its antioxidant properties, a zebrafish model was used, and to confirm its anti-senescent effects, a d-galactose-induced mouse aging model was employed. The anti-senescent mechanism of PURF was examined using a natural senescence HFF model. Furthermore, the anti-senescent target was confirmed using a 3D full T-Skin™ model. ResultsIn vitro biochemical assays demonstrated that flavones exhibited potent antioxidant activity and anti-senescent potential by inhibiting DPPH, hydroxyl radicals, superoxide anion O2−, collagenase, and elastase. It significantly enhanced the antioxidant effect on zebrafish while suppressing ROS and inflammatory injury, up-regulating COL1A1, COL3A1, AMPK, and mTOR gene expression and down-regulating MMP-9, TGF-β, p21, and p16 gene expression suggesting its potential anti-senescent ability. Findings from the D-galactose-induced aging mouse model showed that PURF greatly increased SOD levels, while simultaneously decreasing HYP and MDA levels. In addition, when PURF was given to the HFF cell and 3D full T-Skin™ model, consistent trends were observed in gene and protein expression, with up-regulation of COL1A1, COL3A1, AMPK, and mTOR genes and down-regulation of TGF-β, MMP-1, MMP-9, p21, and p16 genes. Therefore, these preliminary findings indicate that flavones can modulate AMPK/mTOR/TGF-β signalling pathways to exert its influence. ConclusionThe kernel residue of natural P. utilis Royle oil extracted from Yunnan province was previously considered agricultural waste, but we successfully extracted and isolated its flavonoid components. Our preliminary studies demonstrated its potential as an environmentally friendly anti-senescent raw material.

BMP2-ERK-ATF4 Axis-Based 6-methoxybenzofuran Compound I-9 Acts as Candidate Drug for Bone Formation and Anti-Osteoporosis.

As the global population ages, the number of patients with osteoporosis is rapidly rising. The existing first-line clinical drugs are bone resorption inhibitors that have difficulty restoring the bone mass of elderly patients to the safe range. The range and period of use of existing peptides and monoclonal antibodies are limited, and small-molecule bone formation-promoting drugs are urgently required. We established an I-9 synthesis route with high yield, simple operation, and low cost that was suitable for future large-scale production. I-9 administration promoted bone formation and increased bone mass in mice with low bone mass in an aged C57 mouse model. Our findings revealed a hitherto undescribed pathway involving the BMP2-ERK-ATF4 axis that promotes osteoblast differentiation; I-9 has favorable biosafety in mice. This study systematically investigated the efficacy, safety, and mechanism of I-9 for treating osteoporosis and positions this drug for preclinical research in the future. Thus, this study has promoted the development of small-molecule bone-promoting drugs.

An Aloe-Based Composition Constituting Polysaccharides and Polyphenols Protected Mice against D-Galactose-Induced Immunosenescence.

A decline in immune response, exhibited in the form of immunosenescence and inflammaging, is an age-associated disturbance of the immune system known to predispose the elderly to a greater susceptibility to infection and poor vaccine response. Polysaccharides and polyphenols from botanicals are known for their immune modulation effects. Here we evaluated a standardized mushroom-based composition, UP360, from Aloe barbadensis, Poria cocos, and Rosmarinus officinalis, as a natural nutritional supplement for a balanced immune response in an accelerated aging mouse model. Immunosenescence was induced by continual subcutaneous injection of D-galactose (D-gal) at a dose of 500 mg/kg/day to CD-1 mice. UP360 was administered at oral doses of 200 and 400 mg/kg to the mice starting on the 5th week of D-gal injection. The study lasted for a total of 9 weeks. All mice were given a quadrivalent influenza vaccine at 3 µg/animal via intramuscular injection 14 days before the end of the study. A group of D-gal-treated mice treated at 400 mg/kg/day UP360 was kept without vaccination. Whole blood, serum, spleen homogenate, and thymus tissues were used for analysis. UP360 was found to improve the immune response as evidenced by stimulation of innate and adaptive immune responses, increase antioxidant capacity as reflected by augmented SOD and Nrf2, and preserve vital immune organs, such as the thymus, from aging-associated damage. The findings depicted in this report show the effect of the composition in activating and maintaining homeostasis of the immune system both during active infections and as a preventive measure to help prime the immune system. These data warrant further clinical study to explore the potential application of the mushroom-based composition as an adjunct nutritional supplement for a balanced immune response.

Tetramethylpyrazine Nitrone alleviates D-galactose-induced murine skeletal muscle aging and motor deficits by activating the AMPK signaling pathway

Tetramethylpyrazine nitrone (TBN), a novel derivative of tetramethylpyrazine (TMP) designed and synthesized by our group, possesses multi-functional mechanisms of action and displays broad protective effects in vitro and in animal models of age-related brain disorders such as stroke, Alzheimer’s disease (AD), Amyotrophic Lateral Sclerosis (ALS) and Parkinson’s disease (PD). In the present report, we investigated the effects of TBN on aging, specifically on muscle aging and the associated decline of motor functions. Using a D-galactose-induced aging mouse model, we found that TBN could reverse the levels of several senescence and aging markers including p16, p21, ceramides, and telomere length and increase the wet-weight ratio of gastrocnemius muscle tissue, demonstrating its efficacy in ameliorating muscle aging. Additionally, the pharmacological effects of TBN on motor deficits (gait analysis, pole-climbing test and grip strength test), muscle fibrosis (hematoxylin & eosin (HE), Masson staining, and αSMA staining), inflammatory response (IL-1β, IL-6, and TNF-α), and mitochondrial function (ATP, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were also confirmed in the D-galactose-induced aging models. Further experiments demonstrated that TBN alleviated muscle aging and improved the decline of age-related motor deficits through an AMPK-dependent mechanism. These findings highlight the significance of TBN as a potential anti-aging agent to combat the occurrence and development of aging and age-related diseases.