Genomic instability, telomere attrition, epigenetic alterations, mitochondrial dysfunction, loss of proteostasis, deregulated nutrient-sensing, cellular senescence, stem cell exhaustion, and altered intercellular communication were the original nine hallmarks of ageing proposed by López-Otín and colleagues in 2013. The proposal of these hallmarks of ageing has been instrumental in guiding and pushing forward research on the biology of ageing. In the nearly past 10 years, our in-depth exploration on ageing research has enabled us to formulate new hallmarks of ageing which are compromised autophagy, microbiome disturbance, altered mechanical properties, splicing dysregulation, and inflammation, among other emerging ones. Amalgamation of the ‘old’ and ‘new’ hallmarks of ageing may provide a more comprehensive explanation of ageing and age-related diseases, shedding light on interventional and therapeutic studies to achieve healthy, happy, and productive lives in the elderly.
BACKGROUND: Compromised autophagy, including impaired mitophagy and lysosomal function, plays pivotal roles in Alzheimer's disease (AD). Urolithin A (UA) is a gut microbial metabolite of ellagic acid that stimulates mitophagy. The effects of UA's long‐term treatment of AD and mechanisms of action are unknown.METHODS: We addressed these questions in three mouse models of AD with behavioral, electrophysiological, biochemical, and bioinformatic approaches.RESULTS: Long‐term UA treatment significantly improved learning, memory, and olfactory function in different AD transgenic mice. UA also reduced amyloid beta (Aβ) and tau pathologies and enhanced long‐term potentiation. UA induced mitophagy via increasing lysosomal functions. UA improved cellular lysosomal function and normalized lysosomal cathepsins, primarily cathepsin Z, to restore lysosomal function in AD, indicating the critical role of cathepsins in UA‐induced therapeutic effects on AD.CONCLUSIONS: Our study highlights the importance of lysosomal dysfunction in AD etiology and points to the high translational potential of UA.Highlights: Long‐term urolithin A (UA) treatment improved learning, memory, and olfactory function in Alzheimer's disease (AD) mice. UA restored lysosomal functions in part by regulating cathepsin Z (Ctsz) protein. UA modulates immune responses and AD‐specific pathophysiological pathways.
Polyphenols, a class of bioactive compounds with phenolic structures, are abundant in human diets. They have gained attention in biomedical fields due to their beneficial properties, including antioxidant, antibacterial, and anti-inflammatory activities. Therefore, polyphenols can prevent multiple chronic or infectious diseases and may help in the prevention of oral diseases. Oral health is crucial to our well-being, and maintaining a healthy oral microbiome is essential for preventing various dental and systemic diseases. However, the mechanisms by which polyphenols modulate the oral microbiota and contribute to oral health are still not fully understood, and the application of polyphenol products lies in different stages. This review provides a comprehensive overview of the advancements in understanding polyphenols’ effects on oral health: dental caries, periodontal diseases, halitosis, and oral cancer. The mechanisms underlying the preventive and therapeutic effects of polyphenols derived from dietary sources are discussed, and new findings from animal models and clinical trials are included, highlighting the latest achievements. Given the great application potential of these natural compounds, novel approaches to dietary interventions and oral disease treatments may emerge. Moreover, investigating polyphenols combined with different materials presents promising opportunities for developing innovative therapeutic strategies in the treatment of oral diseases.
Current research on human aging has largely been guided by the milestone paper “hallmarks of aging,” which were first proposed in the seminal 2013 paper by Lopez‐Otin et al. Most studies have focused on one aging hallmark at a time, asking whether the underlying molecular perturbations are sufficient to drive the aging process and its associated phenotypes. More recently, researchers have begun to investigate whether aging phenotypes are driven by concurrent perturbations in molecular pathways linked to not one but to multiple hallmarks of aging and whether they present different patterns in organs and systems over time. Indeed, preliminary results suggest that more complex interactions between aging hallmarks must be considered and addressed, if we are to develop interventions that successfully promote healthy aging and/or delay aging‐associated dysfunction and diseases. Here, we summarize some of the latest work and views on the interplay between hallmarks of aging, with a specific focus on mitochondrial dysfunction. Indeed, this represents a significant example of the complex crosstalk between hallmarks of aging and of the effects that an intervention targeted to a specific hallmark may have on the others. A better knowledge of these interconnections, of their cause‐effect relationships, of their spatial and temporal sequence, will be very beneficial for the whole aging research field and for the identification of effective interventions in promoting healthy old age.
FOXO transcription factors modulate aging-related pathways and influence longevity in multiple species, but the transcriptional targets that mediate these effects remain largely unknown. Here, we identify an evolutionarily conserved FOXO target gene, Oxidative stress-responsive serine-rich protein 1 (OSER1), whose overexpression extends lifespan in silkworms, nematodes, and flies, while its depletion correspondingly shortens lifespan. In flies, overexpression of OSER1 increases resistance to oxidative stress, starvation, and heat shock, while OSER1-depleted flies are more vulnerable to these stressors. In silkworms, hydrogen peroxide both induces and is scavenged by OSER1 in vitro and in vivo. Knockdown of OSER1 in Caenorhabditis elegans leads to increased ROS production and shorter lifespan, mitochondrial fragmentation, decreased ATP production, and altered transcription of mitochondrial genes. Human proteomic analysis suggests that OSER1 plays roles in oxidative stress response, cellular senescence, and reproduction, which is consistent with the data and suggests that OSER1 could play a role in fertility in silkworms and nematodes. Human studies demonstrate that polymorphic variants in OSER1 are associated with human longevity. In summary, OSER1 is an evolutionarily conserved FOXO-regulated protein that improves resistance to oxidative stress, maintains mitochondrial functional integrity, and increases lifespan in multiple species. Additional studies will clarify the role of OSER1 as a critical effector of healthy aging.
Background: Parkinson’s disease (PD) is the second most common neurodegenerative disease in middle-aged and elderly populations, whereas there is no cure for PD so far. Novel animal models and medications await development to elucidate the aetiology of PD and attenuate the symptoms, respectively. Methods: A neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), was used in the current study to establish a PD pathologic model in silkworms. The time required to complete specific behaviours was recorded. Dopamine content was detected by ultra-performance liquid chromatography (UPLC). The activity of insect tyrosine hydroxylase (TH) was determined using a double-antibody sandwich method. Oxidative stress was assessed by changes in antioxidant enzyme activity and the content of oxidative products. Results: MPTP-treated silkworms were characterized by impaired motor ability, reduced dopamine content, and elevated oxidative stress level. The expression of TH, a dopamine biosynthetic enzyme within dopaminergic neurons in the brain, was significantly reduced, indicating that dopaminergic neurons were damaged. Moreover, MPTP-induced motility impairment and reduced dopamine level in the silkworm PD model could be rescued after feeding a combination of levodopa (L-dopa [LD]) and carbidopa (CD). MPTP-induced oxidative damage was also alleviated, in ways consistent with other PD animal models. Interestingly, administration of Lycium barbarum polysaccharide (LBP) improved the motor ability, dopamine level, and TH activity, and the oxidative damage was concomitantly reduced in the silkworm PD model. Conclusions: This study provides a promising animal model for elucidating the pathogenesis of PD, as well as a relevant preliminary drug screening (e.g., LBP) and evaluation.