• 생명과학회지
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• 제18권3호
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• pp.344-349
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• 2008

이 논문에서는 신생아와 노인 유래의 섬유아세포들의 노화의 특징들을 비교하여 사람의 나이와 세포의 수명 및 세포 형질의 관계에 대해 연구하였다. 본 연구의 결과는 비록 한가지의 노인세포에 대해 얻어진 것이기는 하지만 다음과 같은 세 가지 중요한 가능성을 제시한다. 첫째로, 노인에서 유래한 섬유아세포의 증식속도가 신생아 유래의 세포에 비해서 느릴 가능성이 있다. 이러한 결과는 실제로 노인 신체에 존재하는 세포가 신생아에 존재하는 세포에 비해 낮은 속도로 증식할 가능성을 시사하는 것으로서, 노인에서 관찰되는 조직실질의 감소 원인을 설명하는 자료가 될 수 있겠다. 둘째로, 노인 유래 섬유아세포의 early passage 세포가 신생아 유래의 세포의 early passage 세포와 동일하게 낮은 수준의 SA ${\beta}-Gal$ 활성, autofluorescence, lysosome 함량, 그리고 활성산소 수준을 갖고 있었다. 이 점은, early passage 때의 세포가 보이는 형질이 신체에 존재하는 세포의 상황과 크게 다르지 않다고 가정할 때, 노인 신체의 조직에 존재하는 세포들이 신생아의 세포와 유사한 상태로 존재할 가능성을 시사하는 것이다. 즉, 노인 신체에서는 in vitro 노화세포에서 나타나는 수준의 세포노화가 일어나 있지 않다는 것이다. 셋째, 노인세포가 노화했을 때는 신생아세포의 경우와 거의 동일한 수준의 활성산소, lysosome, SA ${\beta}-Gal$ activity 증가를 보이고 있었는데, 이는 노인 유래의 세포가 in vitro 배양 시 신생아 유래의 세포보다 더 심하거나 또는 빠른 산화적 손상이나 세포학적 변화를 겪지는 않는다는 것을 보여주는 것으로서, 세포가 보유한 항산화적 기능이 노인이 되면서 크게 약화되지는 않음을 시사하고 있다. 결론적으로 노인 유래의 세포는 세포증식 속도를 제외하면 대체로 신생아 때의 상태와 동일한 세포 내 상태를 갖고 있다고 결론 내릴 수 있겠다.

• Journal of Ginseng Research
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• 제43권4호
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• pp.580-588
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• 2019

Background: Ginsenoside Rg1 has been shown to clear senescence-associated beta-galactosidase (SA-${\beta}$-gal) in cultured cells. It remains unknown whether Rg1 can influence SA-${\beta}$-gal in exercising human skeletal muscle. Methods: To examine SA-${\beta}$-gal change, 12 young men (age $21{\pm}0.2years$) were enrolled in a randomized double-blind placebo controlled crossover study, under two occasions: placebo (PLA) and Rg1 (5 mg) supplementations 1 h prior to a high-intensity cycling (70% $VO_{2max}$). Muscle samples were collected by multiple biopsies before and after cycling exercise (0 h and 3 h). To avoid potential effect of muscle biopsy on performance assessment, cycling time to exhaustion test (80% $VO_{2max}$) was conducted on another 12 participants (age $23{\pm}0.5years$) with the same experimental design. Results: No changes of SA-${\beta}$-gal were observed after cycling in the PLA trial. On the contrary, nine of the 12 participants showed complete elimination of SA-${\beta}$-gal in exercised muscle after cycling in the Rg1 trial (p < 0.05). Increases in apoptotic DNA fragmentation (PLA: +87% vs. Rg1: +133%, p < 0.05) and $CD68^+$ (PLA:+78% vs. Rg1:+121%, p = 0.17) occurred immediately after cycling in both trials. During the 3-h recovery, reverses in apoptotic nuclei content (PLA:+5% vs. Rg1 -32%, p < 0.01) and increases in inducible nitrate oxide synthase and interleukin 6 mRNA levels of exercised muscle were observed only in the Rg1 trial (p < 0.01). Conclusion: Rg1 supplementation effectively eliminates senescent cells in exercising human skeletal muscle and improves high-intensity endurance performance.

• 대한화장품학회지
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• 제45권2호
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• pp.151-159
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• 2019

에르고티오네인은 생체 내에서 우수한 항산화제로서 산화스트레스로부터 세포 보호제로 알려져 있다. 본 연구에서는 에르고티오네인의 라디칼 소거 활성은 자외선에 조사된 사람 섬유아세포 생존율을 향상 시키는 것을 확인하였으며, 세포노화 지표물질인 senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) 활성을 사람 섬유아세포를 이용하여 확인한 결과, 에르고티오네인 $400{\mu}M$ 처리 농도에서 염색된 세포의 수가 약 45%의 SA-${\beta}$-gal의 레벨이 감소하여 세포 노화(senescence)를 억제하는 것을 확인할 수 있었다. 또한, 에르고티오네인은 글리세르알데하이드에 의해 유도된 최종당화산물(AGEs) 생성을 저해하였으며, 카르복시메칠라이신(CML) 발현을 농도의존적으로 저해하는 것으로 나타내었다. 글리옥살에 의해 최종당화산물의 수용체(RAGE)가 발현된 사람 섬유아세포에 에르고티오네인을 처리하였을 때 RAGE의 발현이 농도의존적으로 감소하는 것을 확인하였다. 따라서, 본 연구결과를 바탕으로 에르고티오네인의 항노화 효과와 최종당화산물의 세포 내 축적을 저해할 수 있는 화장품 소재로서 활용가치가 있음을 확인하였다.

• 대한화장품학회지
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• 제39권4호
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• pp.313-322
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• 2013

본 연구에서는 예로부터 민간에서 사용되어진 약초인 토인삼 추출물의 피부보호 효과를 측정하기위해 항산화, 자외선에 의해 유도된 matrix metalloproteinases-1 (MMP-1) 발현저해효과, 자외선에 대한 세포보호효과, 노화세포를 이용한 senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) 활성을 사람 섬유아세포(HDF)를 이용하여 확인하였다. 그 결과, 토인삼 추출물의 free radical과 superoxide radical 소거효과는 처리농도가 증가함에 따라 농도 의존적으로 나타났으며, 토인삼 잎, 줄기 추출물(LSE) 500 ${\mu}g/mL$에서 98.45%와 97.01%의 DPPH와 superoxide radical을 소거하여 우수한 항산화 효과를 나타내었다. 토인삼 잎, 줄기 추출물(LSE)의 MMP-1의 발현 저해효과는 섬유아세포에서 UVA조사 실험에서 우수하게 나타났으며, UVB 조사에 의한 세포보호 효과도 우수하게 나타났다. 또한 노화세포를 이용한 SA-${\beta}$-gal활성은 토인삼 잎, 줄기 추출물(LSE)을 처리하였을 시 염색된 세포의 수가 감소하여 세포내 senescence를 억제하는 것을 확인할 수 있었다. 이상의 결과들을 종합해 보면, 토인삼의 지상부분인 잎, 줄기 추출물(LSE)은 항노화 및 항산화제로서의 우수한 특성으로 피부손상에 의한 산화적 스트레스에 대응하는 새로운 기능성 소재로서의 가능성을 가지는 것으로 평가된다.

• 대한화장품학회지
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• 제43권3호
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• pp.239-245
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• 2017

노화는 생리학적으로 비가역적으로 일어나는 과정으로 노화가 진행됨에 따라 단백질의 산화화학반응 등으로 노화징후가 축적된다. 활성산소와 당화된 최종 당화산물(advanced glycation endproducts, AGEs 최종 당화산물)은 생체 조직과 세포를 공격하여 노화를 촉진한다고 알려져 있다. 본 연구에서는 항산화 물질로 알려진 aminoguanidine을 양성 대조군으로 anti-glycation 효과를 확인하였으며, methoxy PEG-45 thioctate(LA-PEG)를 농도별로 처리하여 anti-glycation 효과를 평가하였다. 실험결과 LA-PEG는 매우 우수한 anti-glycation 효과로 최종 당화산물(AGEs) 생성억제 활성이 매우 우수하게 나타났으며, 항산화 효과와 밀접한 연관을 나타냈다. 또, 세포노화 지표물질인 senescence-associated ${\beta}$-galactosidase ($SA-{\beta}-gal$) 활성을 사람 섬유아세포(HDF)를 이용하여 확인한 결과, LA-PEG를 처리하였을 때 염색된 세포의 수가 감소하여 세포의 senescence를 억제하는 것을 확인할 수 있었다. 본 연구결과, LA-PEG의 anti-glycation 효과 및 산화로 인한 단백질 손상에 대한 보호 효과가 우수하게 나타났으며, 항노화 화장품에 적용 시 효과적으로 적용할 수 있을 것으로 사료된다.

• 대한약침학회지
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• 제21권1호
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• pp.18-25
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• 2018

Objective: D-galactose (D-gal) is well-known agent to induce aging process. In the present study, we selected crocin, the main constituent of Crocus sativus L. (saffron), against D-gal- induced cytotoxicity in human neuroblastoma SH-SY5Y cells. Methods: Pretreated cells with crocin ($25-500{\mu}M$, 24 h) were exposed to D-gal (25-400 mM, 48 h). The MTT assay was used for determination cell viability. Dichlorofluorescin diacetate assay (DCF-DA) and senescence associated ${\beta}$-galactosidase staining assay (SA-${\beta}$-gal) were used to evaluate the generation of reactive oxygen species and beta-galactosidase as an aging marker, respectively. Also advanced glycation end products (AGEs) expression which is known as the main mechanism of age-related diseases was measured by western blot analysis. Results: The findings of our study showed that treatment of cells with D-gal (25-400 mM) for 48h decreased cell viability concentration dependency. Reactive oxygen species (ROS) levels which are known as main factors in age-related diseases increased from $100{\pm}8%$ in control group to $132{\pm}22%$ in D-gal (200 mM) treated cells for 48h. The cytotoxic effects of D-gal decreased with 24h crocin pretreatment of cells. The cell viability at concentrations of $100{\mu}M$, $200{\mu}M$ and $500{\mu}M$ increased and ROS production decreased at concentrations of 200 and $500{\mu}M$ to $111.5{\pm}6%$ and $108{\pm}5%$, respectively. Also lysosomal biomarker of aging and carboxymethyl lysine (CML) expression as an AGE protein, significantly increased in D-gal 200 mM group after 48h incubation compare to control group. Pre-treatment of SHSY-5Y cells with crocin ($500{\mu}M$) before adding D-gal significantly reduced aging marker and CML formation. Conclusion: Treatment of SH-SY5Y cells with crocin before adding of D-gal restored aging effects of D-gal concentration dependency. These findings indicate that crocin has potent anti- aging effects through inhibition of AGEs and ROS production.

• Biomolecules & Therapeutics
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• 제27권3호
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• pp.283-289
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• 2019

Brain aging induces neuropsychological changes, such as decreased memory capacity, language ability, and attention; and is also associated with neurodegenerative diseases. However, most of the studies on brain aging are focused on neurons, while senescence in astrocytes has received less attention. Astrocytes constitute the majority of cell types in the brain and perform various functions in the brain such as supporting brain structures, regulating blood-brain barrier permeability, transmitter uptake and regulation, and immunity modulation. Recent studies have shown that SIRT1 and SIRT2 play certain roles in cellular senescence in peripheral systems. Both SIRT1 and SIRT2 inhibitors delay tumor growth in vivo without significant general toxicity. In this study, we investigated the role of tenovin-1, an inhibitor of SIRT1 and SIRT2, on rat primary astrocytes where we observed senescence and other functional changes. Cellular senescence usually is characterized by irreversible cell cycle arrest and induces senescence- associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity. Tenovin-1-treated astrocytes showed increased SA-${\beta}$-gal-positive cell number, senescence-associated secretory phenotypes, including IL-6 and IL-$1{\beta}$, and cell cycle-related proteins like phospho-histone H3 and CDK2. Along with the molecular changes, tenovin-1 impaired the wound-healing activity of cultured primary astrocytes. These data suggest that tenovin-1 can induce cellular senescence in astrocytes possibly by inhibiting SIRT1 and SIRT2, which may play particular roles in brain aging and neurodegenerative conditions.

• International Journal of Oral Biology
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• 제42권3호
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• pp.91-97
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• 2017

Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide ($H_2O_2$), including the increase in senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated $H_2O_2$-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated $H_2O_2$-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.

• BMB Reports
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• 제50권10호
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• pp.528-533
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• 2017

Peroxiredoxin I (Prx I) plays an important role as a reactive oxygen species (ROS) scavenger in protecting and maintaining cellular homeostasis; however, the underlying mechanisms are not well understood. Here, we identified a critical role of Prx I in protecting cells against ROS-mediated cellular senescence by suppression of $p16^{INK4a}$ expression. Compared to wild-type mouse embryonic fibroblasts (WT-MEFs), Prx $I^{-/-}$ MEFs exhibited senescence-associated phenotypes. Moreover, the aged Prx $I^{-/-}$ mice showed an increased number of cells with senescence associated-${\beta}$-galactosidase (SA-${\beta}$-gal) activity in a variety of tissues. Increased ROS levels and SA-${\beta}$-gal activity, and reduction of chemical antioxidant in Prx $I^{-/-}$ MEF further supported an essential role of Prx I peroxidase activity in cellular senescence that is mediated by oxidative stress. The up-regulation of $p16^{INK4a}$ expression in Prx $I^{-/-}$ and suppression by overexpression of Prx I indicate that Prx I possibly modulate cellular senescence through $ROS/p16^{INK4a}$ pathway.

• Journal of Radiation Protection and Research
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• 제36권3호
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• pp.119-126
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• 2011

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging, and contributes to harmful effects in cultured cells and animal tissues. mtDNA biogenesis genes (NRF-1, TFAM) are essential for the maintenance of mtDNA, as well as the transcription and replication of mitochondrial genomes. Considering that oxidative stress is known to affect mitochondrial biogenesis, we hypothesized that ionizing radiation (IR)-induced reactive oxygen species (ROS) causes mtDNA deletion by modulating the mitochondrial biogenesis, thereby leading to cellular senescence. Therefore, we examined the effects of IR on ROS levels, cellular senescence, mitochondrial biogenesis, and mtDNA deletion in IMR-90 human lung fibroblast cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated at 4 or 8 Gy. Old cells at PD55, and H2O2-treated young cells at PD 39, were compared as a positive control. The IR increased the intracellular ROS level, senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity, and mtDNA common deletion (4977 bp), and it decreased the mRNA expression of NRF-1 and TFAM in IMR-90 cells. Similar results were also observed in old cells (PD 55) and $H_2O_2$-treated young cells. To confirm that a increase in ROS level is essential for mtDNA deletion and changes of mitochondrial biogenesis in irradiated cells, the effects of N-acetylcysteine (NAC) were examined. In irradiated and $H_2O_2$-treated cells, 5 mM NAC significantly attenuated the increases of ROS, mtDNA deletion, and SA-${\beta}$-gal activity, and recovered from decreased expressions of NRF-1 and TFAM mRNA. These results suggest that ROS is a key cause of IR-induced mtDNA deletion, and the suppression of the mitochondrial biogenesis gene may mediate this process.