• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.425-433
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• 2023

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

• International Journal of Oral Biology
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• v.34 no.1
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• pp.21-28
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• 2009

Mutations in DLX3 are associated with both autosomal dominant hypoplastic hypomaturation amelogenesis imperfecta (ADHHAI) and tricho-dento-osseous (TDO) syndrome. ADHHAI is caused by a c.561_562delCT (2bp-del DLX3) mutation whereas TDO syndrome is associated with a c.571_574delGGGG (4bp-del DLX3) mutation. However, although the causal relationships between DLX3 and an enamel phenotype have been established, the pathophysiological role of DLX3 mutations in enamel development has not yet been clarified. In our current study, we prepared expression vectors for wild type and deletion mutant DLX3 products (4bp-del DLX3, 2bp-del DLX3) and examined the effects of their overexpression on the expression of the enamel matrix proteins and proteases. Wild type DLX3 enhanced the expression of matrix metalloprotease 20 (MMP20) mRNA and protein in murine ameloblast-like cells. However, neither a 4bp-del nor 2bp-del DLX3 increased MMP20 expression. Wild type DLX3, but not the above DLX3 mutants, also increased the activity of reporters containing 1.5 kb or 0.5 kb of the MMP20 promoter. An examination of protein stability showed that the half-life of wild type DLX3 protein was less than 12 h whilst that of both deletion mutants was longer than 24 h. Endogenous Dlx3 was also found to be continuously expressed during ameloblast differentiation. Since inactivating mutations in the gene encoding MMP20 are associated with amelogenesis imperfecta, the inability of 4bp-del or 2bp-del DLX3 to induce MMP20 expression suggests a possible involvement of such mutations in the enamel phenotype associated with TDO syndrome or ADHHAI.

• BMB Reports
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• v.53 no.10
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• pp.491-499
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• 2020

The extracellular matrix is a critical component of every human tissue. ECM not only functions as a structural component but also regulates a variety of cellular processes such as cell migration, differentiation, proliferation, and cell death. In addition, current studies suggest that ECM is critical for the pathophysiology of various human diseases. ECM is composed of diverse components including several proteins and polysaccharide chains such as chondroitin sulfate, heparan sulfate, and hyaluronic acid. Each component of ECM exerts its own functions in cellular and pathophysiological processes. One of the interesting recent findings is that ECM is involved in inflammatory responses in various human tissues. In this review, we summarized the known functions of ECM in neuroinflammation after acute injury and chronic inflammatory diseases of the central nerve systems.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.608-619
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• 2018

As distributed generation (DG) is connected to grid, there is new node-type occurring in distribution network. An efficient algorithm is proposed in this paper to calculate power flow for weakly meshed distribution network with DGs in different load models. The algorithm respectively establishes mathematical models focusing on the wind power, photovoltaic cell, fuel cell, and gas turbine, wherein the different DGs are respectively equivalent to PQ, PI, PQ (V) and PV node-type. When dealing with PV node, the algorithm adopts reactive power compensation device to correct power, and the reactive power allocation principle is proposed to determine reactive power initial value to improve convergence of the algorithm. In addition, when dealing with the weakly meshed network, the proposed algorithm, which builds path matrix based on loop-analysis and establishes incident matrix of node voltage and injection current, possesses good convergence and strong ability to process the loops. The simulation results in IEEE33 and PG&G69 node distribution networks show that with increase of the number of loops, the algorithm's iteration times will decrease, and its convergence performance is stronger. Clearly, it can be effectively used to solve the problem of power flow calculation for weakly meshed distribution network containing different DGs.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.214-219
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• 2010

This paper deals with a nonlinear fuzzy $H_{\infty}$ filter design for SOC(state of charge) estimation in Lithium polymer battery. The dynamic equation of the battery cell is modeled as a T-S fuzzy system and the filter is designed via solutions of linear matrix inequalities. In order to illustrate the performance of the designed filter, a computer simulation is performed using the experimental data with the UDDS(urban dynamometer driving schedule) current profile.

• Korean Journal of Materials Research
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• v.18 no.5
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• pp.259-265
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• 2008

The corrosion and degradation factors of a current collector in a molten carbonate fuel cell (MCFC) were investigated to determine the optimized coating thickness of nickel on STS316L. The results show that the surface morphology and electrical properties depended on the nickel coating thickness. The surface morphology gradually changed from a flat to a porous structure along as the nickel coating thickness decreased, and the electrical resistance of the nickel-coated STS316L increased as the nickel coating thickness decreased. This can be attributed to the diffusion of elements of Fe and Cr from the substrate through the nickel grain boundaries. Additionally, carburization in the metal grains or grain boundaries in an anodic environment was found to influence the electrical properties due to matrix distortion. The resistance of Cr-oxide layers formed in an anodic environment causes a drop in the potential, resulting in a decrease in the system efficiency.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.1
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• pp.1-12
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• 2024

Silk sericin, a natural protein from silkworm cocoons, is emerging as a multifunctional biomaterial in biomedicine, particularly in tissue engineering and wound healing. Recent studies have highlighted its biocompatibility, biodegradability, and potential for chemical modification, which allows it to be incorporated into various scaffold architectures. This review article synthesizes current research, including the development of sericin-based hydrogel scaffolds for tissue engineering and sericin's role in enhancing wound healing. Key findings demonstrate sericin's ability to refine scaffold porosity and mechanical strength, expedite tissue healing, and reduce bacterial load in wounds. The integration of sericin into novel bioactive dressings and its use in peripheral nerve injury repair are also discussed, showcasing its adaptability and efficacy. The convergence of these studies illustrates the broad applications of sericin, from scaffold design to clinical interventions, making it a promising material in regenerative medicine and tissue engineering, with the potential to improve patient outcomes significantly.

• Environmental Engineering Research
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• v.15 no.2
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• pp.71-78
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• 2010

To understand the effects of acclimation schemes on the formation of anode biofilms, different electrical performances are characterized in this study, with the roles of suspended and attached bacteria in single-chamber microbial fuel cells (MFCs). The results show that the generation of current in single-chamber MFCs is significantly affected by the development of a biofilm matrix on the anode surface containing abundant immobilized microorganisms. The long-term operation with suspended microorganisms was demonstrated to form a dense biofilm matrix that was able to reduce the activation loss in MFCs. Also, a Pt-coated anode was not favorable for the initial or long-term bacterial attachment due to its high hydrophobicity (contact angle = $124^{\circ}$), which promotes easy detachment of the biofilm from the anode surface. Maximum power ($655.0\;mW/m^2$) was obtained at a current density of $3,358.8\;mA/m^2$ in the MFCs with longer acclimation periods. It was found that a dense biofilm was able to enhance the charge transfer rates due to the complex development of a biofilm matrix anchoring the electrochemically active microorganisms together on the anode surface. Among the major components of the extracellular polymeric substance, carbohydrates ($85.7\;mg/m^2_{anode}$) and proteins ($81.0\;mg/m^2_{anode}$) in the dense anode biofilm accounted for 17 and 19%, respectively, which are greater than those in the sparse anode biofilm.

• Biomolecules & Therapeutics
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• v.31 no.5
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• pp.550-558
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• 2023

Hair loss is a common condition that can have a negative impact on an individual's quality of life. The severe side effects and the low efficacy of current hair loss medications create unmet needs in the field of hair loss treatment. Hyaluronan and Proteoglycan Link Protein 1 (HAPLN1), one of the components of the extracellular matrix, has been shown to play a role in maintaining its integrity. HAPLN1 was examined for its ability to impact hair growth with less side effects than existing hair loss treatments. HAPLN1 was predominantly expressed in the anagen phase in three stages of the hair growth cycle in mice and promotes the proliferation of human hair matrix cells. Also, recombinant human HAPLN1 (rhHAPLN1) was shown to selectively increase the levels of transforming growth factor-β receptor II in human hair matrix cells. Furthermore, we observed concomitant activation of the ERK1/2 signaling pathway following treatment with rhHAPLN1. Our results indicate that rhHAPLN1 elicits its cell proliferation effect via the TGF-β2-induced ERK1/2 pathway. The prompt entering of the hair follicles into the anagen phase was observed in the rhHAPLN1-treated group, compared to the vehicle-treated group. Insights into the mechanism underlying such hair growth effects of HAPLN1 will provide a novel potential strategy for treating hair loss with much lower side effects than the current treatments.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.6
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• pp.28-36
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• 1997

In this work, a highly linear video-speed CMOS current-mode digital-to-analog converter (DAC) is proposed. A newswitching scheme for the current cell matrix of the DAC simultaneously reduces graded and symmetrical errors to improve integral nonlinearities (INL). The proposed DAC is designed to operate at any supply voltage between 3V and 5V, and minimizes the glitch energy of analog outputs with degliching circuits developed in this work. The prototype dAC was implemented in a LG 0.8um n-well single-poly double-metal CMOS technology. Experimental results show that the differential and integral nonlinearities are less than .+-. LSB and .+-.0.8LSB respectively. The DAC dissipates 75mW at a 3V single power supply and occupies a chip area of 2.4 mm * 2.9mm.