• Molecules and Cells
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• v.40 no.2
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• pp.90-99
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• 2017

Caenorhabditis elegans is an important model organism with many useful features, including rapid development and aging, easy cultivation, and genetic tractability. Survival assays using C. elegans are powerful methods for studying physiological processes. In this review, we describe diverse types of C. elegans survival assays and discuss the aims, uses, and advantages of specific assays. C. elegans survival assays have played key roles in identifying novel genetic factors that regulate many aspects of animal physiology, such as aging and lifespan, stress response, and immunity against pathogens. Because many genetic factors discovered using C. elegans are evolutionarily conserved, survival assays can provide insights into mechanisms underlying physiological processes in mammals, including humans.

• BMB Reports
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• v.49 no.2
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• pp.81-92
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• 2016

Insulin/insulin-like growth factor (IGF)-1 signaling (IIS) pathway regulates aging in many organisms, ranging from simple invertebrates to mammals, including humans. Many seminal discoveries regarding the roles of IIS in aging and longevity have been made by using the roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster. In this review, we describe the mechanisms by which various IIS components regulate aging in C. elegans and D. melanogaster. We also cover systemic and tissue-specific effects of the IIS components on the regulation of lifespan. We further discuss IIS-mediated physiological processes other than aging and their effects on human disease models focusing on C. elegans studies. As both C. elegans and D. melanogaster have been essential for key findings regarding the effects of IIS on organismal aging in general, these invertebrate models will continue to serve as workhorses to help our understanding of mammalian aging.

• BMB Reports
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• v.44 no.5
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• pp.291-297
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• 2011

Aging is one of the most complicated biological processes in all species. A number of different model organisms from yeast to monkeys have been studied to understand the aging process. Until recently, many different age-related genes and age-regulating cellular pathways, such as insulin/IGF-1-like signal, mitochondrial dysfunction, Sir2 pathway, have been identified through classical genetic studies. Parallel to genetic approaches, genome-wide approaches have provided valuable insights for the understanding of molecular mechanisms occurring during aging. Gene expression profiling analysis can measure the transcriptional alteration of multiple genes in a genome simultaneously and is widely used to elucidate the mechanisms of complex biological pathways. Here, current global gene expression profiling studies on normal aging and age-related genetic/environmental interventions in widely-used model organisms are briefly reviewed.

• BMB Reports
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• v.52 no.1
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• pp.64-69
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• 2019

The loss of skeletal muscle, called sarcopenia, is an inevitable event during the aging process, and significantly impacts quality of life. Autophagy is known to reduce muscle atrophy caused by dysfunctional organelles, even though the molecular mechanism remains unclear. Here, we have discuss the current understanding of exercise-induced autophagy activation in skeletal muscle regeneration and remodeling, leading to sarcopenia intervention. With aging, dysregulation of autophagy flux inhibits lysosomal storage processes involved in muscle biogenesis. AMPK-ULK1 and the $FoxO/PGC-1{\alpha}$ signaling pathways play a critical role in the induction of autophagy machinery in skeletal muscle, thus these pathways could be targets for therapeutics development. Autophagy has been also shown to be a critical regulator of stem cell fate, which determines satellite cell differentiation into muscle fiber, thereby increasing muscle mass. This review aims to provide a comprehensive understanding of the physiological role of autophagy in skeletal muscle aging and sarcopenia.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.680-686
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• 2023

Aging is a complex series of multi-organ processes that occur in various organisms. As such, an in vivo study using an animal model of aging is necessary to define its exact mechanisms and identify anti-aging substances. Using Drosophila as an in vivo model system, we identified Crataegus pinnatifida extract (CPE) as a novel anti-aging substance. Regardless of sex, Drosophila treated with CPE showed a significantly increased lifespan compared to those without CPE. In this study, we also evaluated the involvement of CPE in aging-related biochemical pathways, including TOR, stem cell generation, and antioxidative effects, and found that the representative genes of each pathway were induced by CPE administration. CPE administration did not result in significant differences in fecundity, locomotion, feeding amount, or TAG level. These conclusions suggest that CPE is a good candidate as an anti-aging food substance capable of promoting a healthy lifespan.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.5
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• pp.212-223
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• 2019

This study is to investigate the relationship between microstructural factors and tensile properties after aging heat treatment of the 15-5PH stainless steel at the temperature range of $450^{\circ}C$, $500^{\circ}C$ and $550^{\circ}C$ for various time. For the aging time of 2 hours, hardness showed maximum at $450^{\circ}C$ and then decreased with increasing aging temperature. While, hardness decreased gradually during aging $450^{\circ}C$, $500^{\circ}C$ and $550^{\circ}C$ from 1 hour to 5 hours but the hardness nearly unchanged until the 100 hours after 5 hours aging. When aging at $450^{\circ}C$, Cu atoms preferentially aggregated at the prior austenite grain boundaries and martensite lath boundaries, and Cu concentration at those boundaries was nearly unchanged even after aging for 100 hours. Therefore it was suggested that the coherency is still maintained after 100 hours aging at $450^{\circ}C$. Aging at $500^{\circ}C$ and $550^{\circ}C$ results in an increase in the concentration of Ni at the martensite lath boundaries and prior austenite grain boundaries, resulting in the formation of reversed austenite. Especially, when aged at $550^{\circ}C$ for 100 hours, the concentration of Ni remarkably increased at those boundaries, and thus the microstructure of herring bone shape was appeared. Considering the migration of Ni atom to the lath boundaries and prior austenite grain boundaries, Ni atoms contributed greatly to the formation of reversed austenite. On the other hand, it was found that Cu atoms hardly moving to those boundaries may not be contributed to the formation of reversed austenite. When aging at $450^{\circ}C$, the coarsening of the precipitated Cu atoms proceeded very slowly with increasing aging time, therefore the decrease in strengths were small but the reduction area was considerably increased due to the softening of the matrix. At the aging temperature of $500^{\circ}C$ and $550^{\circ}C$, the strengths decreased and the elongation and reduction area increased due to the appearance of the reversed austenite. Especially, the increase of reduction area was remarkable.

• IMMUNE NETWORK
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• v.9 no.1
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• pp.8-11
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• 2009

There is mounting evidence that autophagy is involved in diverse physiological and pathological processes that have immense relevance in human development, diseases and aging. Immunity and inflammation are not exceptions. Here, the role of autophagy in the control of immune processes particularly that related to cell death and inflammation is discussed.

• Journal of Families and Better Life
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• v.21 no.2
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• pp.145-154
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• 2003

As the life-expectancy is ever-increasing, and the proportion of the elderly population is growing steadily in every society of the world, it is ever more important to establish what factors allow certain elderly people to age successfully and remain relatively independent while others grow old less successfully and require extensive intervention. However, there is no consensus yet as to what successful aging means. Researchers have defined successful aging in a variety of ways. This study attempted to define the concept of successful aging and to clarify some dimensions of it through literature review. Previous approaches of studying successful aging and related themes were examined. Early perspectives including activity, disengagement, and continuity theories, Selective Optimization with Compensation (SOC) model by Baltes and Baltes, three different conceptions of successful aging, that is, psychological well-being, physical health, and wisdom, and MacArthur research on successful aging have been reviewed for this study. The definition derived from the review is: Keeping up continuous developmental processes to achieve wisdom or ego-integrity, without suffering any major disabilities in either physical or mental functioning, while maintaining psychological well-being and employing SOC strategies, and participating in positive relationships with significant others. The dimensions of successful aging are 1) personal resources, including physical health, cognitive competences, self esteem, and social support 2) adaptation process of SOC, and 3) psychological aspects, including psychological well-being and wisdom.

• Biomolecules & Therapeutics
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• v.21 no.3
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• pp.241-245
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• 2013

Aging is the single most important risk factor that increases susceptibility to many forms of diseases. As such, much effort has been put forward to elucidate the mechanisms behind the processes of aging and to discover novel compounds that retain anti-aging activities. Korean red ginseng has been used for a variety of medical purposes in eastern countries for several thousands of years. It has been shown that Korean red ginseng affects a number of biological activities including, but not limited to, anti-inflammatory, anti-oxidative and anti-diabetic pathways. However, few studies have been performed to evaluate its anti-aging effects with an in vivo system. Here Drosophila melanogaster as an in vivo model organism demonstrates that Korean red ginseng tonic extends lifespan, increases resistance to starvation stress and prevents weight gain. This data suggest that Korean red ginseng may regulate organisms' metabolism in favor of extending lifespan.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.73-80
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• 2011

The experimental investigation focuses on an influence of artificial aging time in longitudinal butt welded Al 6013-T4 aluminum alloy on the fatigue crack growth resistance. The preferred welding processes for this alloy are frequently tungsten inert gas welding (TIG) process due to its comparatively easier applicability and better weldability than other gas metal arc welding. Fatigue crack growth tests were carried out on compact tension specimens (CT) in longitudinal butt TIG welded after T82 heat treatment was varied in three artificial aging times of 6 hours, 18 hours and 24 hours. Of the three artificial aging times, 24 hours of artificial aging time are offering better resistance against the growing fatigue cracks. The superior fatigue crack growth resistance preferred spatial variation of materials within each specimen in the Paris equation based on reliability theory and fatigue crack growth rate by crack length are found to be the reasons for superior fatigue resistance of 24 hours of artificial aging time was compared to other joints. The highest of crack propagation resistance occurs in artificial aging times of 24 hours due to the increase in grain size (fine grained microstructures).