• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.623-634
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• 2005

Human periodontal ligament fibroblast(hPDLF) is very important to cure periodontal tissue because it can be diverged into various cells. This study examined the expression of MMP-1, TIMP-1, periodontal ligament specific PDLs22, Type I collagen, Fibronectin, TIMP-2, telomerase mRNA in a replicative senescence of hPDLF. The periodontal ligament tissue was obtained from periodontally healthy and non-carious human teeth extracted for orthodontic reasons at the Chosun University Hospital of Dentistry with the donors' informed consent. The hPDLF cells were cultured in a medium containing Dulbecco's modified Eagle medium(DMEM, Gibco BRL, USA) supplemented with 10% fetal bovine serum(FBS, Gibco BRL, USA) at 37C in humidified air with 5% $CO_2$. For the reverse transcription-polymerase chain reaction(RT-PCR) analysis, the total RNA of the 2, 4, 8, 16, 18, and 21 passage cells was extracted using a Trizol Reagent(Invitrogen, USA) in replicative hPDL cells. Two passage cells, i.e. young cells, served as the control, and ${\beta}-actin$ served as the internal control for RT-PCR The results of this study about cell morphology and gene expression according to aging of hPDLF using RT-PCR method are as follows: 1. The size of hPDLF was increased with aging and it was showed that the hPDLF was dying in the final passage. 2. PDLs22 mRNA was expressed in young hPDLF of the two, four, and six passage. 3. TIMP-1 mRNA was expressed in young hPDLF of the two and four passage. 4. There was a tendency that MMP-1 mRNA was weakly expressed over eighteen. 5. Type 1 collagen mRNA was expressed in almost all passages, but it was not expressed in the final passage. 6. Fibronectin mRNA was observed in all passages and it was weakly expressed in the final passage. 7. TIMP-2 and telomerase mRNA were not expressed in this study. Based on above results, it was observed that PDLs22, Type 1 collagen, Fibronectin, MMP-1. and TIMP-1 mRNA in hPDLF were expressed differently with aging. The study using the hPDLF that is collected from healthy patients and periodontitis patients needs in further study.

• 생명과학회지
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• 제25권6호
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• pp.724-731
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• 2015

중간엽줄기세포는 성체줄기세포의 한 종류로, 자기재생산능력(self-renwal)과 다분화능(multipotency)을 가지고 있고, 다양한 자양인자(trophic factors)들을 분비한다. 뿐만 아니라, 중간엽줄기세포는 골수, 지방, 탯줄과 같은 조직에서 쉽게 얻을 수 있기 때문에 줄기세포치료에 좋은 도구로 이용되고 있다. 하지만, 줄기세포치료의 효율성을 높이기 위해 추출한 세포의 개체 수를 늘리는 과정에서 중간엽줄기세포는 점차적인 노화를 겪게 되고, 이는 줄기세포 자체의 기능적인 감소를 야기한다. 인체 내에서, 노화된 줄기세포는 조직 내의 항상성 유지에 부정적인 영향 을 미치게 되고, 이러한 상태가 지속되면 대표적인 노인성 질환인 퇴행성 질환의 원인이 된다. 최근 연구들에 의하면 중간엽줄기세포가 노화를 겪을 때, 노화 관련된 DNA 메틸화 패턴의 변화와 히스톤의 변형이 일어남을 확인하였다. 또한, 중간엽줄기세포의 노화에 있어서 DNA 메틸화효소(DNA methyltransferase) 억제제와 히스톤 아세틸화효소(histone deacetylase) 억제제가 부분적으로 노화를 개선하는 효과를 관찰한 연구사례들이 있다. 본 총설에서는, 노화에 따른 후생유전학적인 변화에 의해, 조절되는 노화 관련 유전자들과 중간엽줄기세포의 노화에 대한 연구사례들을 분석하여 서술하고자 한다.

• Nutrition Research and Practice
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• 제1권2호
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

• Biomolecules & Therapeutics
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• 제31권6호
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• pp.629-639
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• 2023

Cardiovascular diseases (CVDs) are the most common cardiovascular system disorders. Cellular senescence is a key mechanism associated with dysfunction of aged vascular endothelium. Hyaluronic acid and proteoglycan link protein 1 (HAPLN1) has been known to non-covalently link hyaluronic acid (HA) and proteoglycans (PGs), and forms and stabilizes HAPLN1-containing aggregates as a major component of extracellular matrix. Our previous study showed that serum levels of HAPLN1 decrease with aging. Here, we found that the HAPLN1 gene expression was reduced in senescent human umbilical vein endothelial cells (HUVECs). Moreover, a recombinant human HAPLN1 (rhHAPLN1) decreased the activity of senescence-associated β-gal and inhibited the production of senescence-associated secretory phenotypes, including IL-1β, CCL2, and IL-6. rhHAPLN1 also downregulated IL-17A levels, which is known to play a key role in vascular endothelial senescence. In addition, rhHAPLN1 protected senescent HUVECs from oxidative stress by reducing cellular reactive oxygen species levels, thus promoting the function and survival of HUVECs and leading to cellular proliferation, migration, and angiogenesis. We also found that rhHAPLN1 not only increases the sirtuin 1 (SIRT1) levels, but also reduces the cellular senescence markers levels, such as p53, p21, and p16. Taken together, our data indicate that rhHAPLN1 delays or inhibits the endothelial senescence induced by various aging factors, such as replicative, IL-17A, and oxidative stress-induced senescence, thus suggesting that rhHAPLN1 may be a promising therapeutic for CVD and atherosclerosis.

• Molecules and Cells
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• 제39권3호
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• pp.266-279
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• 2016

The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) ${\alpha}$ and $PKC{\beta}1$ exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. $PKC{\alpha}$ accompanied pErk1/2 to the nucleus after freeing it from $PEA-15pS^{104}$ via $PKC{\beta}1$ and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of $PKC{\alpha}$ were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated $PKC{\alpha}$ expression and increased epidermal and hair follicle cell proliferation. Thus, $PKC{\alpha}$ downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear $PKC{\alpha}$ degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of $PKC{\alpha}$ expression following TPA treatment reduces pErk1/2-activated SP1 biding to the $p21^{WAF1}$ gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.

• Childhood Kidney Diseases
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• 제12권1호
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• pp.11-22
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• 2008

Telomeres consist of tandem guanine-thymine(G-T) repeats in most eukaryotic chromosomes. Human telomeres are predominantly linear, double stranded DNA as they ended in 30-200 nucleotides(bases,b) 3'-overhangs. In DNA replication, removal of the terminal RNA primer from the lagging strand results in a 3'-overhang of uncopied DNA. This is because of bidirectional DNA replication and specificity of unidirectional DNA polymerase. After the replication, parental and daughter DNA strands have unequal lengths due to a combination of the end-replication problem and end-processing events. The gradual chromosome shortening is observed in most somatic cells and eventually leads to cellular senescence. Telomere shortening could be a molecular clock that signals the replicative senescence. The shortening of telomeric ends of human chromosomes, leading to sudden growth arrest, triggers DNA instability as biological switches. In addition, telomere dysfunction may cause chronic allograft nephropathy or kidney cancers. The renal cell carcinoma(RCC) in women may be less aggressive and have less genomic instability than in man. Younger patients with telomere dysfunction are at a higher risk for RCC than older patients. Thus, telomeres maintain the integrity of the genome and are involved in cellular aging and cancer. By studying the telomeric DNA, we may characterize the genetic determinants in diseases and discover the tools in molecular medicine.

• Molecules and Cells
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• 제46권8호
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• pp.486-495
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• 2023

Lipofuscins are oxidized lipid and protein complexes that accumulate during cellular senescence and tissue aging, regarded as markers for cellular oxidative damage, tissue aging, and certain aging-associated diseases. Therefore, understanding their cellular biological properties is crucial for effective treatment development. Through traditional microscopy, lipofuscins are readily observed as fluorescent granules thought to accumulate in lysosomes. However, lipofuscin granule formation and accumulation in senescent cells are poorly understood. Thus, this study examined lipofuscin accumulation in human fibroblasts exposed to various stressors. Our results substantiate that in glucose-starved or replicative senescence cells, where elevated oxidative stress levels activate autophagy, lipofuscins predominately appear as granules that co-localize with autolysosomes due to lysosomal acidity or impairment. Meanwhile, autophagosome formation is attenuated in cells experiencing oxidative stress induced by a doxorubicin pulse and chase, and lipofuscin fluorescence granules seldom manifest in the cytoplasm. As Torin-1 treatment activates autophagy, granular lipofuscins intensify and dominate, indicating that autophagy activation triggers their accumulation. Our results suggest that high oxidative stress activates autophagy but fails in lipofuscin removal, leaving an abundance of lipofuscin-filled impaired autolysosomes, referred to as residual bodies. Therefore, future endeavors in treating lipofuscin pathology-associated diseases and dysfunctions through autophagy activation demand meticulous consideration.

• 대한화장품학회지
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• 제39권3호
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• pp.177-186
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• 2013

피부 섬유아세포는 인간 피부의 주요 콜라겐 생산 세포이다. 노화가 진행되면, 섬유아세포에서의 콜라겐 생산이 감소되고, matrix metalloproteinase-1 (MMP-1)에 의해 시작되는 콜라겐 조각화가 증가된다. 즉 섬유아세포의 콜라겐 항상성의 불균형으로 인해 피부 collagenous, 세포외기질(ECM)의 구조와 기능이 변형되어, 피부노화가 촉진되는 것이다. Cysteine rich protein 61 (CCN1)는 CCN family의 일부이며, 인간피부의 섬유아세포에서 콜라겐 항상성을 조절하는 단백질이다. 노화된 인간 피부 섬유아세포에서의 CCN1 과 발현은 실질적으로 유형 I procollagen 생성을 감소시킴과 동시에 MMP-1의 발현을 증가시켜 섬유의 콜라겐 저하를 일으킨다. 그리고 노화된 섬유아세포는 노화 전 섬유아세포에 비해 증식률이 감소한다. 본 연구에서 만들어 사용한 복제 노화 피부 섬유아세포는 유형 I procollagen의 생성량이 감소하였고, MMP-1의 발현 수준이 증가하는 특징을 나타냈다. 또한 CCN1 단백질의 발현이 증가되고, 증식률이 감소하는 특징을 나타냈다. 가수분해 구멍갈파래 추출물은 노화 전 섬유아세포에서 새로운 콜라겐의 합성을 촉진하고 자외선에 의해 증가된 MP-1의 발현을 감소시켜 광노화를 개선하는 물질로 알려져 있다. 본 연구에서는 이러한 활성을 나타내는 가수분해 구멍갈파래 추출물을 사용하여, 복제 노화 피부 섬유아세포에서 가수분해 구멍갈파래 추출물에 의한 CN1 단백질의 발현 억제 여부를 조사하였으며, 이들 추출물은 배양된 복제 노화 피부 섬유아세포에서 유형 I procollagen의 생성을 증가시켰으며, MMP-1 발현을 억제시키는 것을 확인하였다. 또한, 콜라겐 항상성을 조절하는 단백질인 CN1 발현을 크게 감소시켰으며, 노화세포의 증식률을 증가시켰다. 이 결과는 복제 노화 섬유아세포가 in vitro 자연 노화모델로 화장품 원료 활성 연구에 사용될 수 있음을 말한다. 그리고 가수분해 구멍갈파래 추출물은 광노화 뿐 아니라 자연노화를 개선하는 피부미용제로 주름개선 기능성 화장품에 사용가능 하다는 것을 의미한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8019-8026
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• 2014

The promyelocytic leukemia (PML) gene is a gene known to be a tumor suppressor, although recent data suggest that it has a dual function in tumorigenesis. It was initially discovered in acute promyelocytic leukemia (APL) in which a t(15; 17) chromosomal translocation fused it to the retinoic acid receptor alpha ($RAR{\alpha}$). It has been shown to be involved in various types of cancer. It has at least 6 nuclear isoforms and a cytoplasmic type with different characteristics. Its multiple functions in growth inhibition, apoptosis induction, replicative senescence, inhibition of oncogenic transformation, and suppression of migration and angiogenesis have made it a therapeutic target for cancer therapy. However, its dual role in the process of tumorigenesis has made this field challenging. In this review, we discuss PML structure, functions and expression in tumors.

• 생명과학회지
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• 제28권9호
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• pp.1042-1047
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• 2018

홍조류인 꼬물꼬시래기(Gracilaria vermiculophylla)는 전 세계의 해변 지역에 널리 퍼져 있으며 아시아 국가에서 식량 자원으로 이용되어왔다. 이전 연구에 따르면, Gracilaria 속 홍조류 추출물에서 항산화 및 항염증 효과가 보고 되었다. 본 연구에서는 노화된 인간의 골수 유래 중간엽 줄기세포(hBM-MSCs)를 이용하여 Gracilaria vermiculophylla 추출물(GV-Ex)의 항노화 효과를 조사하였다. MTT 분석와 immunoblot 분석(apoptotic protein p53과 cleaved caspase-3)을 이용하여, GV-Ex 전처리는 산화적 스트레스에 의해 손상된 hBM-MSCs의 세포생존력을 향상시킴을 확인하였다. 또, 세포내 생성된 ROS는 장기간 배양 된 MSCs (Passages 17; P-17)와 P-7 MSC에서 측정하여 서로 비교하였는데, P-17 MSC에서 증가되었고, GV-Ex 처리하면(GV-Ex treated P-17 MSCs) 유의하게 감소되었다. 또한, 항산화 효소인 SOD1와 SOD2, CAT의 발현 역시 GV-Ex 처리함에 따라 복원됨을 관찰하였다. 노화 표지단백질인 p53와 p21, p16 등의 발현 또한 GV-Ex를 처리한 P-17 MSC에서 감소되었다. 줄기세포의 골세포(osteocytes) 혹은 지방세포(adipocytes)로 분화하는 능력 역시 GV-Ex를 처리한 P-17 MSCs에서 개선되었다. 이상과 같은 결과를 통해, GV 추출물은 노화된 줄기세포의 기능을 개선함을 시사한다.