• 한국발생생물학회지:발생과생식
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• 제11권2호
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• pp.85-96
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• 2007

중간엽 줄기세포(MSC)를 체외배양할 때 사용하는 소태아혈청 (FBS)의 생물학적 불안전성은 이를 임상적으로 사용하는데 있어 제한점으로 작용한다. 본 연구에서는 소태아혈청 및 인간의 제대혈청을 사용하여 인간의 양막유래 중간엽 줄기세포 (HAM)를 각각 배양한 후, 세포의 성장속도와 유전자 및 단백질의 발현 양상을 비교하였다. 제왕절개 후 얻은 양막으로부터 HAM을 분리하여 10% FBS, 5% HCS 혹은 10% HCS가 각각 첨가된 DMEM 배양액에서 배양하였으며, 초기와 후기 계대의 세포를 얻어 이들의 생물학적 특성을 비교 분석하였다. 역전자 중합효소반응 결과, 혈청의 종류에 상관없이 배양된 세포들은 모두 OCT-4, Rex-1, SCF, FGF-5, BMP-4, nestin, NCAM, GATA-4, HLA-ABC 유전자를 발현하였으며, 이러한 발현은 초기 및 후기 계대의 세포에서도 마찬가지로 나타났다. 세포면역화학 반응 결과, FBS 혹은 HCS를 첨가한 배양액에서 배양된 HAM은 4번째 계대에서 collagen I, II, III, XII, fibronectin, $\alpha$-smooth muscle actin, vimentin, CK18, CD54, FSP, TRA-1-60, SSEA-3, -4, HLA ABC 단백질을 뚜렷하게 발현하였다. 그러나 desmin 단백질은 FBS가 첨가된 배양액에서 배양된 HAM에서만 발현되었고 vWF 단백질은 HCS가 첨가된 배양액에서 배양된 HAM에서만 발현되었다. 결론적으로 유전자와 단백질의 발현양상을 살펴본 결과, HCS가 첨가된 배양액에서 배양된 HAM은 전형적인 인간성체줄기세포의 특징을 나타내고 있으며, FBS가 첨가된 배양액과 비교하여 동등한 성장 촉진 효과를 가지는 것으로 보인다.

• Applied Microscopy
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• 제33권2호
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• pp.131-143
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• 2003

메뚜기 체내와 체외에서 혈구 분화경로를 광학현미경과 전자현미경으로 관찰하였다. 조혈기관에서 혈구의 형성은 망상세포에 둘러싸인 줄기세포에서부터 유래되었으며, 줄기세포에서부터 원시혈구, 무정형혈구, I형 과립혈구, II형 과립혈구, 소구혈구 및 편도혈구가 각각 분화되는 것을 확인하였다. 곤충배지에 배양된 조혈조직에서 각각 다른 형태의 혈구들이 분화되어 방출되었다. 그러나, 이들 혈구들의 유사분열상은 관찰되지 않았다. 배지의 조혈기관에서 분화된 세포들의 형태학적 특징들은 메뚜기 체내의 조혈기관에서 분화된 세포들과 같았다. 이와 같은 결과는 줄기세포가 각각의 서로 다른 혈구들로 직접 분화하는 것을 의미한다. 본 연구 결과 조혈기관의 줄기세포는 각각의 혈구로 직접 분화할 수 있는 기능을 가지고 있었으며, 체내와 체외에서 한번 형성된 순환 혈구는 다른 혈구의 형태로 변형되지 않았다. 메뚜기에서 순환혈구의 유지는 복부 등쪽 첫 번째 마디에서 여덟 번째 마디 사이의 익상근 위에 광범위하게 존재하고 있는 조혈기관에 전적으로 의존하였다.

• 식물조직배양학회지
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• 제27권6호
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.657-667
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• 2016

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at $10^6$ or $10^5$ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

• Clinical and Experimental Reproductive Medicine
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• 제29권2호
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• pp.139-147
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• 2002

Objective : This study was to establish a reproducible differentiation system from the parthenogenetic mouse embryonic stem (P-mES02) cells into functional cardiomyocytes like as in vitro fertilization mouse embryonic stem (mES01) cells. Materials and Methods: To induce differentiation, P-mES02 cells were dissociated and aggregated in suspension culture environment for embryoid body (EB) formation. For differentiation into cardiomyocytes, day 4 EBs were treated with 0.75% dimethyl sulfoxide (DMSO) for another 4 days (4-/4+) and then were plated onto gelatin-coated dish. Cultured cells were observed daily using an inverted light microscope to determine the day of contraction onset and total duration of continuous contractile activity for each contracting focus. This frequency was compared with the results of DMSO not treated P-mES02 group (4-/4-) and mES01 groups (4-/4+ or 4-/4-). For confirm the generation of cardiomyocytes, beating cell masses were treated with trypsin-EDTA, dispersed cells were plated onto glass coverslips and incubated for 48 h. Attached cells were fixed using 4% paraformaldehyde and incubated with specific antibodies (Abs) to detect cardiomyocytes (anti-sarcomeric ? -actinin Ab, 1 : 100; anti-cardiac troponin I Ab, 1 : 2000) for 1 h. And the cells were finally treated with FITC or TRITC labelled 2nd Abs, respectively, then they were examined under fluorescence microscopy. Results: Rhythmically contracting areas in mES01 or P-mES02 cells were firstly appeared at 9 or 10 days after EBs plating, respectively. The highest cumulative frequency of beating EBs was not different in both treatment groups (mES01 and P-mES02, 4-/4+) with the results of 61.3 % at 13 days and 69.8% at 15 days, respectively. Also, the contracting duration of individual beating EBs was different from minimal 7 days to maximal 53 days. However, DMSO not treated groups (mES01 and P-mES02, 4-/4-) also had contracting characteristics although their frequency was a few compared to those of DMSO treated groups (6.0% and 4.0%). Cells recovered from the spontaneously contracting areas within EBs in both treated groups were stained positively with muscle specific anti-sarcomeric ? -actinin Ab and cardiac specific anti-cardiac troponin I Ab. Conclusion: This study demonstrated that the P-mES02 cell-derived cardiomyocytes displayed similarly structural properties to mES01 cell-derived cardiomyocytes and that the DMSO treatment enhanced the cardiomyocytes differentiation in vitro.

• 폴리머
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• 제30권1호
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• pp.14-21
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• 2006

조직공학 기술은 in vitro와 in vivo에서 초기 세포 부착과 차후의 조직형성을 위해 3차원적인 지지체로서 다공성의 생분해성 담체의 사용이 필수적이다. 소장점막하조직(small intestinal submucosa, SIS)은 고유의 인장력과 생체적합성 때문에 생체물질로서 사용될 잠재력을 가지고 있는 콜라겐 조직이다. 근육유래 줄기세포는 배양조건에 따라 골세포, 연골세포, 및 근육세포 등으로 분화가 가능하다고 알려져 있다. 본 연구에서는 SIS를 함유한 락타이드-글리콜라이드 공중합체(PLGA) 다공성 지지체를 용매캐스팅/염추출법으로 제조하였고, 전자주사현미경 및 수은다공측정계를 이용하여 특성을 결정하였다 세포의 생존율과 성장률은 MTT(3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide) 분석 방법을 이용하였고 골로 분화된 세포를 알칼라인 포스파테이즈(ALP) 활성을 측정하여 확인하였다. SIS가 함유된 지지체와 SIS가 함유되지 않은 지지체를 면역결핍 쥐의 피하에 삽입하여 이들의 골형성 정도를 비교하여 보았다. 조직을 파라핀으로 고정시켜 슬라이드를 제조한 후 hematoxylin과 eosin, 트라이크롬 및 본쿠사 염색을 실시하였다. 천연/합성 하이브리드 담체로서의 SIS/PLGA 담체가 PLGA 단독으로 사용하였을 때와 비교하여 볼 때 골형성이 우수하였는데 이는 SIS 내에 함유하고 있는 여러 생체활성분자에 기인한 것으로 추측되었다.

• BMB Reports
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• 제57권2호
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• pp.116-121
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• 2024

We investigated the therapeutic potential of bone marrow-derived mesenchymal stem cell-conditioned medium (BMSC-CM) on immortalized renal proximal tubule epithelial cells (RPTEC/TERT1) in a fibrotic environment. To replicate the increased stiffness characteristic of kidneys in chronic kidney disease, we utilized polyacrylamide gel platforms. A stiff matrix was shown to increase α-smooth muscle actin (α-SMA) levels, indicating fibrogenic activation in RPTEC/TERT1 cells. Interestingly, treatment with BMSC-CM resulted in significant reductions in the levels of fibrotic markers (α-SMA and vimentin) and increases in the levels of the epithelial marker E-cadherin and aquaporin 7, particularly under stiff conditions. Furthermore, BMSC-CM modified microRNA (miRNA) expression and reduced oxidative stress levels in these cells. Our findings suggest that BMSC-CM can modulate cellular morphology, miRNA expression, and oxidative stress in RPTEC/TERT1 cells, highlighting its therapeutic potential in fibrotic kidney disease.

• Journal of Ginseng Research
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• 제48권1호
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• pp.12-19
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• 2024

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

• Archives of Plastic Surgery
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• 제35권1호
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• pp.13-19
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• 2008

Purpose: Human adipose tissue-derived mesenchymal stem cells(hATSCs) can be differentiated into multiple mesenchymal lineages, including bone, cartilage, and muscle. And growth hormone play important roles in the normal growth and development of the CNS. In this study, we explored whether the transplanted hATSCs and growth hormones could improve functional recoveries from rats with contusive spinal cord injury. Methods: We divided 30 female rats, which were subjected to a weight driven implant spinal cord injury, into 3 groups with 10 rats each; Group A as a control group, group B with hATSCs transplantation on injured region, and group C with hATSCs transplantation and GH administration for 7 days. Then, we researched their neurologic functional recoveries before and 2, 4, and 8 weeks after transplantation using Basso-Beattie-Bresnahan (BBB) locomotor rating scale. And we checked Y-chromosome positive cells by FISH(Fluorescent in situ hybridization) to identify the survival of transplanted mesenchymal stem cells. Results: After 4 weeks of transplantation, the group B and group C showed significant improvement of neurologic function on BBB locomotor rating scale in comparison with the group A(Group A: $13.1{\pm}0.58$, Group B: $14.6{\pm}0.69$, Group C: $14.9{\pm}0.56$). Moreover, the group C displayed meaningful recovery of neurologic function after 8 weeks in comparison with group B (Group B: $15.7{\pm}0.63$, Group C: $16.5{\pm}1.14$). The group A, the control one, improved for 5 weeks after injury, and had no more recovery. On the other hand, Group B and C showed the improvement of neurologic function continuously for 9 weeks after injury. Conclusion: In this study, we found out that hATSCs transplantation have an effect on neurologic functional recovery of spinal cord injured rat and GH injection seems to bring the synergistic results on this good tendency.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.16-31
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• 2023

Cultured meat is a potential sustainable food generated by the in vitro myogenesis of muscle satellite (stem) cells (MSCs). The self-renewal and differentiation properties of MSCs are of primary interest for cultured meat production. MSC proliferation and differentiation are influenced by a variety of growth factors such as insulin-like growth factors (IGF-1 and IGF-2), transforming growth factor beta (TGF-β), fibroblast growth factors (FGF-2 and FGF-21), platelet-derived growth factor (PDGF) and hepatocyte growth factor (HGF) and by hormones like insulin, testosterone, glucocorticoids, and thyroid hormones. In this review, we investigated the roles of growth factors and hormones during cultured meat production because these factors provide signals for MSC growth and structural stability. The aim of this article is to provide the important idea about different growth factors such as FGF (enhance the cell proliferation and differentiation), IGF-1 (increase the number of myoblasts), PDGF (myoblast proliferation), TGF-β1 (muscle repair) and hormones such as insulin (cell survival and growth), testosterone (muscle fiber size), dexamethasone (myoblast proliferation and differentiation), and thyroid hormones (amount and diameter of muscle fibers and determine the usual pattern of fiber distributions) as media components during myogenesis for cultured meat production.