• 생명과학회지
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• 제32권4호
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• pp.318-324
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• 2022

PPARγ와 C/EBPα는 adipose tissue 발생에 필요한 핵심 adipogenic TFs이다. 두 TFs는 adipose tissue의 배아 발생에 있어 초기 adipogenesis와 adipocytes 유전자 발현을 조절한다. Adipose expansion은 adipose tissue가 태어난 뒤에도 계속 팽창이 지속되는 것을 말한다. 이러한 adipose expansion은 후기 adipogenesis의 과정인 lipogenesis가 요구된다. 특히 간과 adipose tissue은 탄수화물이 기본적으로 fatty acids으로 전환되는 de novo lipogenesis (DNL)의 주요 장기이다. Fatty acids는 이어서 glycerol-3-phosphate에 에스테르화되어 adipocytes의 lipid droplets 생성을 위해 triglycerides로 전환된다. 간의 DNL이 활발하게 연구가 된 반면, in vivo에서 adipocytes의 DNL은 아직 잘 알려져 있지 않다. 그러므로, adipose expansion과 DNL에 대한 이해는 비만, 2형 당뇨 그리고 대사성 질환을 위한 치료제 개발에 도움을 줄 수 있다. Adipocytes에서 DNL 유전자 발현은 ChREBP나 SREBP1a와 같은 lipogenic TFs 뿐 아니라, lipogenesis coactivator에 의해 전사 수준에서 조절된다. 최근 in vivo 연구에 의해 lipogenesis 유전자 발현과 adipose expansion의 새로운 측면이 밝혀졌다. 향후 구체적인 분자기전 연구는 어떻게 영양분이 DNL과 adipose expansion을 조절하는 지를 규명해 줄 것이다. 본 리뷰논문은 전사조절 관점에서 adipocytes와 adipose expansion에 있어 DNL에 대한 최신 연구결과를 요약정리 할 것이다.

• 생명과학회지
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• 제24권5호
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• pp.573-587
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• 2014

혈관신생은 모든 조직의 성장과 발달, 그리고 상처회복 등에 매우 중요하다. 지방조직은 우리 몸에서 가장 혈관이 발달된 조직으로서 각 지방세포들은 모세혈관에 둘러싸여 있으며 신생혈관들은 지방세포에 영양분과 산소를 공급한다. 혈관의 내피세포들은 파라크린 신호경로, 세포외 성분, 세포들 간의 직접적인 작용을 통해 지방세포와 교류한다. 활성화된 지방세포들은 VEGF, FGF-2, leptin, HGF와 같은 혈관신생인자들을 생성하며, 이들은 단독으로 혹은 협력하여 혈관신생을 증가시키고 지방조직의 성장과 대사를 촉진한다. 따라서 혈관신생 억제제들은 비만과 비만관련 질환을 치료하는데 유용할 것으로 생각된다.

• Archives of Plastic Surgery
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• 제39권6호
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• pp.585-592
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• 2012

During the past decade, many studies using platelet-rich plasma (PRP) or adipose-derived stem cells (ASCs) have been conducted in various medical fields, from cardiovascular research to applications for corneal diseases. Nonetheless, there are several limitations of practical applications of PRP and ASCs. Most reports of PRP are anecdotal and few include controls to determine the specific role of PRP. There is little consensus regarding PRP production and characterization. Some have reported the development of an antibody to bovine thrombin, which was the initiator of platelet activation. In the case of ASCs, good manufacturing practices are needed for the production of clinical-grade human stem cells, and in vitro expansion of ASCs requires approval of the Korea Food and Drug Administration, such that considerable expense and time are required. Additionally, some have reported that ASCs could have a potential risk of transformation to malignant cells. Therefore, the authors tried to investigate the latest research on the efficacy and safety of PRP and ASCs and report on the current state and regulation of these stem cell-based therapies.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.466-469
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• 2016

External volume expansion of the recipient site by suction has been proposed as a way of improving fat graft survival. The objective of this study was to present an innovative and simple intraoperative external expansion system to enhance small-volume autologous fat grafting (40-80 mL) and to discuss its background and its mechanism of action. In this system, expansion is performed using a complete vacuum delivery system known as the Kiwi VAC-6000M with a PalmPump (Clinical Innovations). The recipient site is rapidly expanded intraoperatively 10 times for 30 seconds each with a negative pressure of up to 550 mm Hg before autologous fat injection. During this repetitive stimulation, the tissues become grossly expanded, developing macroscopic swelling that regresses slowly over the course of hours following the cessation of the stimulus. The system sets various mechanisms in motion, including scar release, mechanical stimulation, edema, ischemia, and inflammation, which provide an environment conducive for cell proliferation and angiogenesis. In order to maintain the graft construct in its expansive state, all patients are encouraged postoperatively to use the Kiwi three times daily for one minute per session over the course of three days. The handling of this system is simple for both the patients and the surgeon. Satisfactory clinical outcomes have been achieved without significant complications.

• 생명과학회지
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• 제17권5호
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• pp.678-686
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• 2007

인간중간엽줄기세포는(Human mesenchymal stem cells, hMSC) 골수, 지방, 피부, 근육, 혈액에 존재하며, 뼈, 연골, 지방, 근육, 신경세포로 분화가능성이 보고되어 손상조직의 재생을 위한 재료로서뿐만 아니라 유전자치료의 매개체로 이용될 수 있는 가능성이 제안되고 있다. 인간중간엽줄기세포의 적절한 배양조건에는 소 태아혈청(fetal bovine serum, FBS)이 요구되어지므로 세포치료에는 소 태아혈청이 다수 포함되어 있을 것이며 세포배양 배지 유래 소 태아혈청의 단백질에 의한 면역거부반응이 우려된다. 이미 앞선 연구에서 자가혈청 하에서 인체지방줄기세포 분리와 계속적인 세포배양을 실시하였을 때 인체지방줄기세포의 증식능력과 다 분화 능이 유지되며 면역결핍 생쥐에 골수의 말초혈액에서 유래된 CD34세포 이식 시 안착 능을 촉진함을 보였다. 본 연구에서 인체지방줄기세포가 인체혈청 하에서 배양되었을 때 소 태아혈청 하에서 배양할 때 발현하는 표면항원을 유지함을 확인했으며 microarray를 사용하여 유전자 발현을 비교했다. 유 세포 분석을 통하여 인체혈청 하에서 계속적으로 배양된 인체유래지방줄기세포에서 HLA-DR, CD117, CD29 와 CD44 의 발현이 소 태아혈청 하에서 배양했을 때와 비슷함을 밝혔다. 그러나 인체혈청 하에서 배양된 인체지방줄기세포의 유전자 발현형태와 소 태아혈청 하에서 배양된 세포의 유전자 발현형태 간에는 상당한 차이를 보였다. 그러므로 본 연구는 인체혈청 하에서 배양된 인체지방기질줄기세포가 임상적용을 위한 선행 데이터로써 직접적인 추정을 하기 위해서는 인체지방기질줄기세포 이식연구에 in vivo 동물실험연구가 수행되어져야 함을 제시하고 있다.

• BMB Reports
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• 제50권11호
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• pp.572-577
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• 2017

In most clinical applications, human mesenchymal stem cells (hMSCs) are expanded in large scale before their administration. Prolonged culture in vitro results in cellular senescence-associated phenotypes, including accumulation of reactive oxygen species (ROS) and decreased cell viabilities. Profiling of stem cell-related genes during in vitro expansion revealed that numerous canonical pathways were significantly changed. To determine the effect of selenocysteine (Sec), a rare amino acid found in several antioxidant enzymes, on the replicative senescence in hMSCs, we treated senescent hMSCs with Sec. Supplementation of Sec in the culture medium in late-passage hMSCs reduced ROS levels and improved the survival of hMSCs. In addition, a subset of key antioxidant genes and Sec-containing selenoproteins showed increased mRNA levels after Sec treatment. Furthermore, ROS metabolism and inflammation pathways were predicted to be downregulated. Taken together, our results suggest that Sec has antioxidant effects on the replicative senescence of hMSCs.

• 한국발생생물학회지:발생과생식
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• 제23권3호
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• pp.213-221
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• 2019

The epididymal fat of mouse is a part of visceral fat deposit and is divided into the distal or proximal part based on its histochemical characteristics. Even though the formation of the epididymal fat pad begins before the birth, a detailed adipogenic procedure of the epididymal fat has not been revealed. The epididymal fat pad becomes enlarged and expended with age, and expressional changes of numerous genes are associated with the maturation of fat tissues. In the present research, expressional patterns of adipose tissue-related genes in the distal epididymal fat of mouse at 2, 5, 8, and 12 months of postnatal age were determined by a quantitative real-time polymerase chain reaction (PCR) analysis. The lowest transcript levels of fatty acid binding protein 4 (Fabp4), lipoprotein lipase (Lpl), delta like non-canonical Notch ligand 1 (Dlk1), peroxisome proliferator-activated receptor gamma (Pparg), leptin (Lep), adiponectin (Adipoq), and resistin (Retn) were detected at 2 months of age, except fatty acid synthase (Fasn) showing the lowest level at 5 months of age. Even though expression of Lep and Fabp4 were gradually increased until 12 months of age, significant increases of Pparg and Adipoq transcript levels were continued until 8 months of age. The transcript levels of Lpl, Rent, Dlk1, and Fasn were significantly increased at 8 months of age, compared with those at 2 months of age. The current findings suggest that the expansion of the distal epididymal fat of mouse during postnatal period would be companied with differential expression of various adipocyte-associated molecules.

• BMB Reports
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• 제52권3호
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• pp.220-225
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• 2019

We have identified a mechanism to diminish the proliferative capacity of cells during cell expansion using human adipose-derived stromal cells (hAD-SCs) as a model of replicative senescence. hAD-SCs of high-passage numbers exhibited a reduced proliferative capacity with accelerated cellular senescence. Levels of key bioactive sphingolipids were significantly increased in these senescent hAD-SCs. Notably, the transcription of sphingosine kinase 1 (SPHK1) was down-regulated in hAD-SCs at high-passage numbers. SPHK1 knockdown as well as inhibition of its enzymatic activity impeded the proliferation of hAD-SCs, with concomitant induction of cellular senescence and accumulation of sphingolipids, as seen in high-passage cells. SPHK1 knockdown-accelerated cellular senescence was attenuated by co-treatment with sphingosine-1-phosphate and an inhibitor of ceramide synthesis, fumonisin $B_1$, but not by treatment with either one alone. Together, these results suggest that transcriptional down-regulation of SPHK1 is a critical inducer of altered sphingolipid profiles and enhances replicative senescence during multiple rounds of cell division.

• Korean Journal of Radiology
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• 제24권10호
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• pp.974-982
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• 2023

Objective: Recent studies have highlighted the active and potential role of perivascular adipose tissue (PVAT) in atherosclerosis and aneurysm progression, respectively. This study explored the link between PVAT attenuation and abdominal aortic aneurysm (AAA) progression using computed tomography angiography (CTA). Materials and Methods: This multicenter retrospective study analyzed patients with AAA who underwent CTA at baseline and follow-up between March 2015 and July 2022. The following parameters were obtained: maximum diameter and total volume of the AAA, presence or absence of intraluminal thrombus (ILT), maximum diameter and volume of the ILT, and PVAT attenuation of the aortic aneurysm at baseline CTA. PVAT attenuation was divided into high (> -73.4 Hounsfield units [HU]) and low (≤ -73.4 HU). Patients who had or did not have AAA progression during the follow-up, defined as an increase in the aneurysm volume > 10 mL from baseline, were identified. Kaplan-Meier and multivariable Cox regression analyses were used to investigate the association between PVAT attenuation and AAA progression. Results: Our study included 167 participants (148 males; median age: 70.0 years; interquartile range: 63.0-76.0 years), of which 145 (86.8%) were diagnosed with AAA accompanied by ILT. Over a median period of 11.3 months (range: 6.0-85.0 months), AAA progression was observed in 67 patients (40.1%). Multivariable Cox regression analysis indicated that high baseline PVAT attenuation (adjusted hazard ratio [aHR] = 2.23; 95% confidence interval [CI], 1.16-4.32; P = 0.017) was independently associated with AAA progression. This association was demonstrated within the patients of AAA with ILT subcohort, where a high baseline PVAT attenuation (aHR = 2.23; 95% CI, 1.08-4.60; P = 0.030) was consistently independently associated with AAA progression. Conclusion: Elevated PVAT attenuation is independently associated with AAA progression, including patients of AAA with ILT, suggesting the potential of PVAT attenuation as a predictive imaging marker for AAA expansion.

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.111-118
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• 2017

Objective: Adipose tissue plays a key role in the development of obesity and diabetes. We previously reported that lignosulfonic acid suppresses the rise in blood glucose levels through the inhibition of ${\alpha}$-glucosidase activity and intestinal glucose absorption. The purpose of this study is to examine further biological activities of lignosulfonic acid. Methods: In this study, we examined the effect of lignosulfonic acid on differentiation of 3T3-L1 cells. Results: While lignosulfonic acid inhibited proliferation (mitotic clonal expansion) after induction of differentiation, lignosulfonic acid significantly increased the size of accumulated lipid droplets in the cells. Semi-quantitative reverse transcription polymerase chain reaction analysis showed that lignosulfonic acid increased the expression of the adipogenic transcription factor, peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), leading to increased glucose transporter 4 (Glut-4) expression and 2-deoxyglucose uptake in differentiated 3T3-L1 cells. Additionally, feeding lignosulfonic acid to diabetic KK-Ay mice suppressed increase of blood glucose level. Conclusion: Lignosulfonic acid may be useful as a functional anti-diabetic component of food.