• BMB Reports
• /
• 제33권6호
• /
• pp.525-530
• /
• 2000

The nerve growth factor (NGF) induces neuronal differentiation and neurite outgrowth of PC12 cells, whereas epidermal growth factors (EGF) stimulate growth and proliferation of the cells. In spite of this difference, NGF-or EGF-treated PC12 cells share various properties in cellular-signaling pathways. These include the activation of the phosphoinositide (PI)-3 kinase, 70 kDa S6 kinase, and in the mitogen-activated protein (MAP) kinase pathway, following the binding of these growth factors to intrinsic receptor tyrosine kinases (RTKs). Therefore, many studies have been attempted to access the critical signaling events in determining the differentiation and proliferation of PC12 cells. In this study, we investigated the cytosolic phospholipase $A_2$ ($cPLA_2$) in neurite behavior in order to identify the differences of signaling pathways between the NGF-induced differentiation and the EGF-induced proliferation of PC12 cells. We have showed here that the $cPLA_2$ was translocated from cytosol to membrane only in NGF-treated cells. We also demonstrated that this translocation is associated with NGF-induced activation of phospholipase $C-{\gamma}(PLC-{\gamma})$, which elevates intracellular $Ca^{2+}$ concentration. These results reveal that the translocation of $cPLA_2$ may be a requisite event in the neuronal differentiation of PC12 cells. Various phospholipase inhibitors were used to confirm the importance of these enzymes in the differentiation of PC12 cells. Neomycin B, a PLC inhibitor, dramatically inhibited the neurite outgrowth, and two distinct $PLA_2$ inhibitors, 4-bromophenacyl bromide (BPB) and arachidonyltrifluoro-methyl ketone ($AACOCF_3$) also suppressed the neurite outgrowth of the cells, as well Taken together, these data indicated that $cPLA_2$ is involved in NGF-induced neuronal differentiation and neurite outgrowth of PC12 cells.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권8호
• /
• pp.1183-1189
• /
• 2017

Objective: Owing to the public availability of complete genome sequences, including avian species, massive bioinformatics analyses may be conducted for computational gene prediction and the identification of gene regulatory networks through various informatics tools. However, to evaluate the biofunctional activity of a predicted target gene, in vivo and in vitro functional genomic analyses should be a prerequisite. Methods: Due to a lack of quail genomic sequence information, we first identified the partial genomic structure and sequences of the quail SH3 domain containing ring finger 2 (SH3RF2) gene. Subsequently, SH3RF2 was knocked out using clustered regularly interspaced short palindromic repeat/Cas9 technology and single cell-derived SH3RF2 mutant sublines were established to study the biofunctional activity of SH3RF2 in quail myoblast (QM7) cells during muscle differentiation. Results: Through a T7 endonuclease I assay and genotyping analysis, we established an SH3RF2 knockout (KO) QM7#4 subline with 61 and 155 nucleotide deletion mutations in SH3RF2. After the induction of myotube differentiation, the expression profiles were analyzed and compared between regular QM7 and SH3RF2 KO QM7#4 cells by global RNA sequencing and bioinformatics analysis. Conclusion: We did not detect any statistically significant role of SH3RF2 during myotube differentiation in QM7 myoblast cells. However, additional experiments are necessary to examine the biofunctional activity of SH3RF2 in cell proliferation and muscle growth.

• Macromolecular Research
• /
• 제13권4호
• /
• pp.285-292
• /
• 2005

We developed alginate beads loaded with transforming growth $factor-{\beta}_{1}(TGF-{\beta}_{1})$ to examine the possible application of the scaffold and cytokine carrier in tissue engineering. In this study, bone marrow stromal cells (BMSCs) and $TGF{\beta}_{1}$ were uniformly encapsulated in the alginate beads and then cultured in vitro. The cell morphology and shape of the alginate beads were observed using inverted microscope, scanning electron microscope (SEM), histological staining and RT-PCR to confirm chondrogenic differentiation. The amount of the $TGF{\beta}_{1}$ released from the $TGF-{\beta}_{1}$ loaded alginate beads was analyzed for 28 days in vitro in a phosphate buffered saline (pH 7.4) at $37^{\circ}C$. We observed the release profile of $TGF-{\beta}_{1}$ from $TGF-{\beta}_{1}$ loaded alginate beads with a sustained release pattern for 35 days. Microscopic observation showed the open cell pore structure and abundant cells with a round morphology in the alginate beads. In addition, histology and RT-PCR results revealed the evidence of chondrogenic differentiation in the beads. In conclusion, these results confirmed that $TGF-{\beta}_{1}$ loaded alginate beads provide excellent conditions for chondrogenic differentiation.

• International Journal of Stem Cells
• /
• 제16권1호
• /
• pp.44-51
• /
• 2023

Background and Objectives: DNA methyltransferases (Dnmts) play an important role in regulating DNA methylation during early developmental processes and cellular differentiation. In this study, we aimed to investigate the role of Dnmts in neural differentiation of embryonic stem cells (ESCs) and in maintenance of the resulting neural stem cells (NSCs). Methods and Results: We used three types of Dnmt knockout (KO) ESCs, including Dnmt1 KO, Dnmt3a/3b double KO (Dnmt3 DKO), and Dnmt1/3a/3b triple KO (Dnmt TKO), to investigate the role of Dnmts in neural differentiation of ESCs. All three types of Dnmt KO ESCs could form neural rosette and differentiate into NSCs in vitro. Interestingly, however, after passage three, Dnmt KO ESC-derived NSCs could not maintain their self-renewal and differentiated into neurons and glial cells. Conclusions: Taken together, the data suggested that, although deficiency of Dnmts had no effect on the differentiation of ESCs into NSCs, the latter had defective maintenance, thereby indicating that Dnmts are crucial for self-renewal of NSCs.

• 기술혁신학회지
• /
• 제1권2호
• /
• pp.192-207
• /
• 1998

This paper focuses on the relationship between innovation and export performance of technology-based firms in Korea. This study analyses the relationship between innovative activity and firm's performances using a sample of 760 technology-based firms in Korea. As for the firm's performance indicators, export is employed. The empirical results support that innovation has a positive effect on firm's export performance. However, for small and medium firms, the relationship between innovative activity and export performance is an U-shape quadratic form, which shows that small firms takes a minimum innovative expenditure in order to access the abroad market. Also, with product differentiation, innovative firms tends to devot more to domestic market than to abroad market. Therefore, it can be concluded that innovative activity builds market power and accelerates export performance. And product differentiation through advertising expenditure make innovative firms less exporting.

• Animal Bioscience
• /
• 제34권6호
• /
• pp.1078-1087
• /
• 2021

Objective: Skeletal muscle satellite cells (SMSCs) are significant for the growth, regeneration, and maintenance of skeletal muscle after birth. However, currently, few studies have been performed on the isolation, culture and inducing differentiation of goose muscle satellite cells. Previous studies have shown that C1q and tumor necrosis factor-related protein 3 (CTRP3) participated in the process of muscle growth and development, but its role in the goose skeletal muscle development is not yet clear. This study aimed to isolate, culture, and identify the goose SMSCs in vitro. Additionally, to explore the function of CTRP3 in goose SMSCs. Methods: Goose SMSCs were isolated using 0.25% trypsin from leg muscle (LM) of 15 to 20 day fertilized goose eggs. Cell differentiation was induced by transferring the cells to differentiation medium with 2% horse serum and 1% penicillin streptomycin. Immunofluorescence staining of Desmin and Pax7 was used to identify goose SMSCs. Quantitative realtime polymerase chain reaction and western blot were applied to explore developmental expression profile of CTRP3 in LM and the regulation of CTRP3 on myosin heavy chains (MyHC), myogenin (MyoG) expression and Notch signaling pathway related genes expression. Results: The goose SMSCs were successfully isolated and cultured. The expression of Pax7 and Desmin were observed in the isolated cells. The expression of CTRP3 decreased significantly during leg muscle development. Overexpression of CTRP3 could enhance the expression of two myogenic differentiation marker genes, MyHC and MyoG. But knockdown of CTRP3 suppressed their expression. Furthermore, CTRP3 could repress the mRNA level of Notch signaling pathway-related genes, notch receptor 1, notch receptor 2 and hairy/enhancer-of-split related with YRPW motif 1, which previously showed a negative regulation in myoblast differentiation. Conclusion: These findings provide a useful cell model for the future research on goose muscle development and suggest that CTRP3 may play an essential role in skeletal muscle growth of goose.

• Journal of Animal Science and Technology
• /
• 제50권3호
• /
• pp.315-320
• /
• 2008

• BMB Reports
• /
• 제42권6호
• /
• pp.338-343
• /
• 2009

The Wnt/$\beta$-catenin signaling pathway alters adipocyte differentiation by inhibiting adipogenic gene expression. $\beta$-catenin plays a central role in the Wnt/$\beta$-catenin signaling pathway. In this study, we revealed that tumour necrosis factor-$\alpha$ (TNF-$\alpha$), a potential negative regulator of adipocyte differentiation, inhibits porcine adipogenesis through activation of the Wnt/$\beta$-catenin signaling pathway. Under the optimal concentration of TNF-$\alpha$, the intracellular $\beta$-catenin protein was stabilized. Thus, the intracellular lipid accumulation of porcine preadipocyte was suppressed and the expression of important adipocyte marker genes, including peroxisome proliferator-activated receptor-$\gamma$ (PPAR$\gamma$) and CCAAT/enhancer binding protein-$\alpha$ (C/EBP$\alpha$), were inhibited. However, a loss of $\beta$-catenin in porcine preadipocytes enhanced the adipogenic differentiation and attenuated TNF-$\alpha$ induced anti-adipogenesis. Taken together, this study indicated that TNF-$\alpha$ inhibits adipogenesis through stabilization of $\beta$-catenin protein in porcine preadipocytes.

• Journal of Animal Science and Technology
• /
• 제66권1호
• /
• pp.204-218
• /
• 2024

Elsholtzia fruticosa (EF) is present in tropical regions throughout South Asian countries as well as the Himalayas. Although it has been used as a traditional medicine to treat digestive, respiratory, and inflammatory issues, its effect on preadipocyte differentiation is unknown. In this study, we examined the effects of a methanol extract prepared from EF on the differentiation of 3T3-L1 preadipocytes. Cell differentiation was assessed by microscopic observation and oil-red O staining. The expression of adipogenic and lipogenic genes, including PPARγ and C/EBPα, was measured by western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR), to provide insight into adipogenesis and lipogenesis mechanisms. The results indicated that EF promotes the differentiation of 3T3-L1 preadipocytes, with elevated lipid accumulation occurring in a concentration-dependent manner without apparent cytotoxicity. EF enhances the expression of adipogenic and lipogenic genes, including PPARγ, FABP4, adiponectin, and FAS, at the mRNA and protein levels. The effect of EF was more pronounced during the early and middle stages of 3T3-L1 cell differentiation. Treatment with EF decreased C/EBP homologous protein (CHOP) mRNA and protein levels, while increasing C/EBPα and PPARγ expression. Treatment with EF resulted in the upregulation of cyclin E and CDK2 gene expression within 24 h, followed by a decrease at 48 h, demonstrating the early-stage impact of EF. A concomitant increase in cyclin-D1 levels was observed compared with untreated cells, indicating that EF modulates lipogenic and adipogenic genes through intricate mechanisms involving CHOP and cell cycle pathways. In summary, EF induces the differentiation of 3T3-L1 preadipocytes by increasing the expression of adipogenic and lipogenic genes, possibly through CHOP and cell cycle-dependent mechanisms.

• Molecules and Cells
• /
• 제42권3호
• /
• pp.200-209
• /
• 2019

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have been used as promising tools for regenerative medicine, disease modeling, and drug screening. Traditional and common strategies for pluripotent stem cell (PSC) differentiation toward disease-relevant cell types depend on sequential treatment of signaling molecules identified based on knowledge of developmental biology. However, these strategies suffer from low purity, inefficiency, and time-consuming culture conditions. A growing body of recent research has shown efficient cell fate reprogramming by forced expression of single or multiple transcription factors. Here, we review transcription factor-directed differentiation methods of PSCs toward neural, muscle, liver, and pancreatic endocrine cells. Potential applications and limitations are also discussed in order to establish future directions of this technique for therapeutic purposes.