• Journal of Periodontal and Implant Science
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• 제47권6호
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• pp.402-415
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• 2017

Purpose: The aim of this study was to determine the effects of patterned human periodontal ligament stem cell (hPDLSC) sheets fabricated using a thermoresponsive substratum. Methods: In this study, we fabricated patterned hPDLSC sheets using nanotopographical cues to modulate the alignment of the cell sheet. Results: The hPDLSCs showed rapid monolayer formation on various surface pattern widths. Compared to cell sheets grown on flat surfaces, there were no significant differences in cell attachment and growth on the nanopatterned substratum. However, the patterned hPDLSC sheets showed higher periodontal ligamentogenesis-related gene expression in early stages than the unpatterned cell sheets. Conclusions: This experiment confirmed that patterned cell sheets provide flexibility in designing hPDLSC sheets, and that these stem cell sheets may be candidates for application in periodontal regenerative therapy.

• BMB Reports
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• 제44권5호
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• pp.347-351
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• 2011

The testis is major male gonad responsible for spermatogenesis and steroidogenesis. Much knowledge is still remained to be learned about the control of these events. In this study, we performed a comprehensive bioinformatics analysis on 1,196 mouse testis proteins screened from public protein database. Integrated function and pathway analysis were performed through Database for Annotation, Visualization and Integrated Discovery (DAVID) and ingenuity Pathway Analysis (IPA), and significant features were clustered. Protein membrane organization and gene density on chromosomes were analyzed and discussed. The enriched bioinformatics analysis could provide clues and basis to the development of diagnostic markers and therapeutic targets for infertility and male contraception.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3509-3515
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• 2015

Background: Diallyl disulfide (DADS) may exert potent anticancer action both in vitro and in vivo. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between DADS and pyruvate kinase (PKM2). Materials and Methods: $KG1{\alpha}$, a leukemia cell line highly expressing PKM2 was used with a cell counting kit (CCK)-8 and flow cytometry (FCM) to investigate the effects of DADS. Relationships between PKM2 and DADS associated with phosphorylation of EGFR, ERK1/2 and MEK, were assessed by western blot analysis. Results: In $KG1{\alpha}$ cells highly expressing PKM2, we found that DADS could affect proliferation, apoptosis and EGFR/ERK/PKM2 signaling pathways, abrogating EGF-induced nuclear accumulation of PKM2. Conclusions: These results suggested that DADS suppressed the proliferation of $KG1{\alpha}$ cells, providing evidence that its proapoptotic effects are mediated through the inhibition of EGFR/ERK/PKM2 signaling pathways.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.61-70
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• 2022

Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.

• Biomolecules & Therapeutics
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• 제26권5호
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• pp.464-473
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• 2018

Cripto is a small glycosylphosphatidylinositol-anchored signaling protein that can detach from the anchored membrane and stimulate proliferation, migration, differentiation, vascularization, and angiogenesis. In the present study, we demonstrated that Cripto positively affected proliferation and survival of mesenchymal stem cells (MSCs) without affecting multipotency. Cripto also increased expression of phosphorylated janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), 78 kDa glucose-regulated protein (GRP78), c-Myc, and cyclin D1. Notably, treatment with an anti-GRP78 antibody blocked these effects. In addition, pretreatment with STAT3 short interfering RNA (siRNA) inhibited the increase in p-JAK2, c-Myc, cyclin D1, and BCL3 levels caused by Cripto and attenuated the pro-survival action of Cripto on MSCs. We also found that incubation with Cripto protected MSCs from apoptosis caused by hypoxia or $H_2O_2$ exposure, and the level of caspase-3 decreased by the Cripto-induced expression of B-cell lymphoma 3-encoded protein (BCL3). These effects were sensitive to down-regulation of BCL3 expression by BCL3 siRNA. Finally, we showed that Cripto enhanced expression levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). In summary, our results demonstrated that Cripto activated a novel biochemical cascade that potentiated MSC proliferation and survival. This cascade relied on phosphorylation of JAK2 and STAT3 and was regulated by GRP78. Our findings may facilitate clinical applications of MSCs, as these cells may benefit from positive effects of Cripto on their survival and biological properties.

• 대한의생명과학회지
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• 제21권1호
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• pp.40-49
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• 2015

Mesenchymal stem cells (MSCs) have the ability to self-renew and differentiate into multi-lineage cells, thus highlighting the feasibility of using umbilical cord blood-derived MSCs (UCB-MSCs) for cell-therapy and tissueengineering. However, the low numbers of UCB-MSC derived from clinical samples requires that an ex vivo expansion step be implemented. As most stem cells reside in low oxygen tension environments (i.e., hypoxia), we cultured the UCBMSCs under 3% $O_2$ or 21% $O_2$ and the following parameters were examined: proliferation, senescence, differentiation and stem cell specific gene expression. UCB-MSCs cultured under hypoxic conditions expanded to significantly higher levels and showed less senescence compared to UCB-MSCs cultured under normoxic conditions. In regards to differentiation potential, UCB-MSCs cultured under hypoxic and normoxic conditions both underwent similar levels of osteogenesis as determined by ALP and von Kossa assay. Furthermore, UCB-MSCs cultured under hypoxic conditions exhibited higher expression of OCT4, NANOG and SOX2 genes. Moreover, cells expanded under hypoxia maintained a stem cell immnunophenotype as determined by flow cytometry. These results demonstrate that the expansion of human UCB-MSCs under a low oxygen tension microenvironment significantly improved cell proliferation and differentiation. These results demonstrate that hypoxic culture can be rapidly and easily implemented into the clinical-scale expansion process in order to maximize UCB-MSCs yield for application in clinical settings and at the same time reduce culture time while maintaining cell product quality.

• The Korean Journal of Physiology and Pharmacology
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• 제20권5호
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.699-709
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• 2018

BACKGROUND: Diabetes mellitus is a major health concern in current scenario which has been found to affect people of almost all ages. The disease has huge impact on global health; therefore, alternate methods apart from insulin injection are being explored to cure diabetes. Therefore, this review mainly focuses on the current status and therapeutic potential of stem cells mainly mesenchymal stem cells (MSCs) for Type 1 diabetes mellitus in preclinical animal models as well as humans. METHODS: Current treatment for Type 1 diabetes mellitus mainly includes use of insulin which has its own limitations and also the underlying mechanism of diseases is still not explored. Therefore, alternate methods to cure diabetes are being explored. Stem cells are being investigated as an alternative therapy for treatment of various diseases including diabetes. Few preclinical studies have also been conducted using undifferentiated MSCs as well as in vitro MSCs differentiated into ${\beta}$ islet cells. RESULTS: These stem cell transplant studies have highlighted the benefits of MSCs, which have shown promising results. Few human trials using stem cells have also affirmed the potential of these cells in alleviating the symptoms. CONCLUSION: Stem cell transplantation may prove to be a safe and effective treatment for patients with Type 1 diabetes mellitus.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.268-268
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• 2006

Due to their multipotency, stem cells can differentiate into a variety of specialized cell types, such as chondrocytes, osteoblasts, myoblasts, and nerve cells. As an alternative to mature tissue cells, stem cells are of importance in tissue engineering and regenerative medicine. Since interactions between scaffold and cells play an important role in the tissue development in vitro, synthetic oligopeptides have been immobilized onto polymeric scaffolds to improve specific cell attachment and even to stimulate cell differentiation. In this study, chondrogenic differentiation of stem cells was evaluated using surface-modified PLLA scaffolds, i.e., either hydrophilic acrylic acid (AA)-grafted PLLA or RGD-immobilized one. Porous PLLA scaffolds were prepared using a gas foaming method, followed by plasma treatment and subsequent grafting of AA to introduce a hydrophilicity (PLLA-PAA). This was further processed to fix RGD peptide to make an RGD-immobilized scaffold (PLLA-PAA-RGD). Stem cells were seeded at $1{\times}10^{6}$ cells per scaffold and the cell-PLLA constructs were cultured for up to 4 weeks in the chondrogenic medium. Using these surface-modified scaffolds, adhesion, proliferation, and chondrogenic differentiation of stem cells were evaluated. The surface of PLLA scaffolds turned hydrophilic (water contact angle, 45 degrees) with both plasma treatment and AA grafting. The hydrophilicity of RGD-immobilized surface was not significantly altered. Cell proliferation rate on the either PLLA-PAA or PLLA-PAA-RGD surface was obviously improved, especially with the RGD-immobilized one as compared to the control PLLA one. Chondrogenic differentiation was clearly identified with Safranin O staining of GAG in the AA- or RGD-grafted PLLA substrates. This study demonstrated that modified polymer surfaces may provide better environment for chondrogenesis of stem cells.

• Korean Chemical Engineering Research
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• 제50권4호
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• pp.610-613
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• 2012

본 연구에서는 삼백초 추출물 25%, 뽕나무 줄기추출물 20%, 닥나무 줄기추출물 20% 등을 함유한 복합수목추출물의 화장품소재로서의 이용가능성을 검토하였다. 소재 시험으로는 세포독성시험, 엘라스타제 억제효과시험, 티로시나제 억제효과시험, 항산화효과시험 및 온도 안정성시험이 실시되었다. 복합수목추출물은 세포독성이 낮았으며, 우수한 엘라스타제 억제효과와 항산화효과를 보여주었으나 티로시나제 억제효과는 다소 낮았다. 추출물을 함유한 스킨, 로션 및 에센스 제형을 제조하여 온도 안정성시험 결과 스킨과 에센스 제형은 우수한 안정성을 보여주었으나 로션은 상분리가 관찰되고, 점도의 변화가 심하여 제형의 변경이 필요한 것으로 나타났다. 따라서 삼백초 추출물, 뽕나무 추출물 및 닥나무 추출물을 함유한 복합수목추출물은 화장품소재로서 응용 가능성이 높음을 알 수 있었다.