Improved Secretory Production of the Sweet-Tasting Protein, Brazzein, in <i>Kluyveromyces lactis</i>

Yun, Cho-Rong,Kong, Ji-Na,Chung, Ju-Hee,Kim, Myung-Chul,Kong, Kwang-Hoon American Chemical Society 2016 Journal of agricultural and food chemistry Vol.64 No.32

<P>Brazzein is an intensely sweet protein with high stability over a wide range of pH values and temperatures, due to its four disulfide bridges. Recombinant brazzein production through secretory expression in Kluyveromyces lactis is reported, but is inefficient due to incorrect disulfide formation, which is crucial for achieving the final protein structure and stability. Protein disulfide bond formation requires protein disulfide isomerase (PDI) and Erolp. Here, we overexpressed KIPDI in K. lactis or treated the cells with dithiothreitol to overexpress KIEROI and improve brazzein secretion. KIPDI and KIERO1 overexpression independently increased brazzein secretion in K. lactis by 1.7-2.2- and 1.3-1.6-fold, respectively. Simultaneous overexpression of KlPDI and KlERO1 accelerated des-pE1M-brazzein secretion by approximately 2.6-fold compared to the previous system. Moreover, intracellular misfolded/unfolded recombinant des-pE1M-brazzein was significantly decreased. In conclusion, increased KlPDI and KIEROI expression favors brazzein secretion, suggesting that correct protein folding may be crucial to brazzein secretion in K. lactis.</P>

Aerosol Jet Deposition of CuInS2 Thin Films

Rong Fan,Seon Mi Kong,Dong Chan Kim,Chee Won Chung 한국진공학회 2011 한국진공학회 학술발표회초록집 Vol.40 No.0

In vivo Pharmacokinetics, Activation of MAPK Signaling and Induction of Phase II/III 911Drug Metabolizing Enzymes/Transporters by Cancer Chemopreventive CompoundBHA in the Mice

Rong Hu,Guoxiang Shen,Usha Rao Yerramilli,Wen Lin,Changjiang Xu,Sujit Nair,Ah-Ng Tony Kong 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.10

Phenolic antioxidant butylated hydroxyanisole (BHA) is a commonly used food preservative with broad biological activities, including protection against chemical-induced carcinogenesis, acute toxicity of chemicals, modulation of macromolecule synthesis and immune response, induction of phase II detoxifying enzymes, as well as its undesirable potential tumor-promoting activities. Understanding the molecular basis underlying these diverse biological actions of BHA is thus of great importance. Here we studied the pharmacokinetics, activation of signaling kinases and induction of phase II/III drug metabolizing enzymes/transporter gene expression by BHA in the mice. The peak plasma concentration of BHA achieved in our current study after oral administration of 200 mg/kg BHA was around 10 μM. This in vivo concentration might offer some insights for the many in vitro cell culture studies on signal transduction and induction of phase II genes using similar concentrations. The oral bioavailability (F) of BHA was about 43% in the mice. In the mouse liver, BHA induced the expression of phase II genes including NQO-1, HO-1, γ-GCS, GST-pi and UGT 1A6, as well as some of the phase III transporter genes, such as MRP1 and Slco1b2. In addition, BHA activated distinct mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), as well as p38, suggesting that the MAPK pathways may play an important role in early signaling events leading to the regulation of gene expression including phase II drug metabolizing and some phase III drug transporter genes. This is the first study to demonstrate the in vivo pharmacokinetics of BHA, the in vivo activation of MAPK signaling proteins, as well as the in vivo induction of Phase II/III drug metabolizing enzymes/transporters in the mouse livers.

Signal Transduction Events Elicited by Natural Products: Role of MAPK and Caspase Pathways in Homeostatic Response and Induction of Apoptosis

Kong, Ah-Ng Tony,Yu, Rong,Chen, Chi,Mandlekar, Sandhya,Primiano, Thomas The Pharmaceutical Society of Korea 2000 Archives of Pharmacal Research Vol.23 No.1

Many natural products elicit diverse pharmacological effects. Using two classes of potential chemopreventive compounds, the phenolic compounds and the isothiocyanates, we review the potential utility of two signaling events, the mitogen-activated protein kinases (MAPKs) and the ICE/Ced-3 proteases (caspases) stimulated by these agents in mammalian cell lines. Studies with phenolic antioxidants (BHA, tBHQ), and natural products (flavonoids; EGCG, ECG, and isothiocyanates; PEITC, sulforaphane), provided important insights into the signaling pathways induced by these compounds. At low concentrations, these chemicals may activate the MAPK (ERK2, JNK1, p38) leading to gene expression of survival genes (c-Fos, c-Jun) and defensive genes (Phase II detoxifying enzymes; GST, QR) resulting in survival and protective mechanisms (homeostasis response). Increasing the concentrations of these compounds will additionally activate the caspase pathway, leading to apoptosis (potential cytotoxicity). Further increment to suprapharmacological concentrations will lead to nonspecific necrotic cell death. The wider and narrow concentration ranges between the activation of MAPK/gene induction and caspases/cell death exhibited by phenolic compounds and isothiocyanates, respectively, in mammalian cells, may reflect their respective therapeutic windows in vivo. Consequently, the studies of signaling pathways elicited by natural products will advance our understanding of their efficacy and safety, of which many man become important therapeuitc drugs of the future.

THE GAITS AND WALKING CONTROL OF HT-II QUADRUPED WALKING ROBOT

Rong, Hong Bing,Gang, Kong Fan,Biao, Chen Xiong,Yi, Wang Shu 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1

This paper proposes three kinds of gait for HT-II Quadruped Walking Robot. In order that HT-II Quadruped Walking Robot is able to walk stably on ground, a software is developed which consists of three parts; gait-table produce programe ; gait-table check programe and joint drive programe. These three kinds of gait form the basis for further studying of fusing of static and dynamic gaits.

An investigation on tribological properties of the chemically capped zinc borate(ZB)/MoS2 nanocomposites in oil

Pei-Rong Wu,Yu-Mei Feng,Ting Ge,Ying-Chao Kong,Zhan-Sheng Ma,Zan Liu,Zhi-Lin Cheng 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

The surface of self-made MoS2 nanosheets with five-layer structure was successively decorated by zinc borate (ZB) nanoparticles with coordination enhancement on the tribological performance and modified by three types of modifiers for improving dispersivity in oil. A series of characterizations determined the chemical modification and composite structure of the ZB/MoS2 nanocomposites. The tribological properties of the chemically capped ZB/MoS2 nanocomposites were extensively examined on a ball-on-ball wear tester. The average friction coefficient and average wear scar diameter of the OA-ZB/MoS2-based oil dropped by about 25.2% and 52.2%, and furthermore the extreme pressure performance increased by about 15.2% compared to oil.

Prognostic Significance of Beta-Catenin Expression in Patients with Esophageal Carcinoma: a Meta-analysis

Zeng, Rong,Duan, Lei,Kong, Yu-Ke,Wu, Xiao-Lu,Wang, Ya,Xin, Gang,Yang, Ke-Hu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Many studies have reported ${\beta}$-catenin involvement in the development of esophageal carcinoma (EC), but its prognostic significance for EC patients remains controversial. Therefore, we conducted this meta-analysis to explore the issue in detail. After searching PubMed, EMBASE, Web of Science, and Chinese Biomedical Literature Database, we included a total of ten relevant studies. We pooled the overall survival (OS) data using RevMan 5.2 software. The results showed that aberrant expression of ${\beta}$-catenin was associated with a significant increase of mortality risk (hazard ratio 1.71, 95%CI 1.46-2.01; p<0.00001). Subgroup analyses further suggested that aberrant expression of ${\beta}$-catenin resulted in poor OS of EC patients regardless of histological type of EC, study location or criteria for aberrant expression of ${\beta}$-catenin, and the sensitivity analyses revealed that the result was robust. The meta-analysis revealed that aberrant expression of ${\beta}$-catenin could be a predicative factor of poor prognosis for EC patients.

In vivo Pharmacokinetics, Activation of MAPK Signaling and Induction of Phase II/III Drug Metabolizing Enzymes/Transporters by Cancer Chemopreventive Compound BHA in the Mice

Hu, Rong,Shen, Guoxiang,Yerramilli, Usha Rao,Lin, Wen,Xu, Changjiang,Nair, Sujit,Kong, Ah-Ng Tony The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.10

Phenolic antioxidant butylated hydroxyanisole (BHA) is a commonly used food preservative with broad biological activities, including protection against chemical-induced carcinogenesis, acute toxicity of chemicals, modulation of macromolecule synthesis and immune response, induction of phase II detoxifying enzymes, as well as its undesirable potential tumor-promoting activities. Understanding the molecular basis underlying these diverse biological actions of BHA is thus of great importance. Here we studied the pharmacokinetics, activation of signaling kinases and induction of phase II/III drug metabolizing enzymes/transporter gene expression by BHA in the mice. The peak plasma concentration of BHA achieved in our current study after oral administration of 200 mg/kg BHA was around $10\;{\mu}M$. This in vivo concentration might offer some insights for the many in vitro cell culture studies on signal transduction and induction of phase II genes using similar concentrations. The oral bioavailability (F) of BHA was about 43% in the mice. In the mouse liver, BHA induced the expression of phase II genes including NQO-1, HO-1, ${\gamma}-GCS$, GST-pi and UGT 1A6, as well as some of the phase III transporter genes, such as MRP1 and Slco1b2. In addition, BHA activated distinct mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), as well as p38, suggesting that the MAPK pathways may play an important role in early signaling events leading to the regulation of gene expression including phase II drug metabolizing and some phase III drug transporter genes. This is the first study to demonstrate the in vivo pharmacokinetics of BHA, the in vivo activation of MAPK signaling proteins, as well as the in vivo induction of Phase II/III drug metabolizing enzymes/transporters in the mouse livers.

Hsa_circ_0003602 Contributes to the Progression of Colorectal Cancer by Mediating the miR-149-5p/SLC38A1 Axis

Wu Rong,Tang Shiyu,Wang Qiuxiao,Kong Pengfei,Liu Fang 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.2

Background/Aims: We aimed to investigate the role and working mechanism of Homo sapiens circular RNA_0003602 (hsa_circ_0003602) in colorectal cancer (CRC) development. Methods: The expression of circ_0003602, miR-149-5p, and solute carrier family 38 member 1 (SLC38A1) was detected by quantitative real-time polymerase chain reaction. RNase R assays were conducted to determine the characteristics of circ_0003602. CCK-8 assays, flow cytometry analysis, transwell invasion assays, wound healing assays and tube formation assays were employed to evaluate cell viability, apoptosis, invasion, migration, and angiogenesis. All protein levels were examined by Western blot or immunohistochemistry assay. The glutamine metabolism was monitored by corresponding glutamine, α-ketoglutarate and glutamate assay kits. Dualluciferase reporter assay was utilized to confirm the targeted combination between miR-149-5p and circ_0003602 or SLC38A1. A xenograft tumor model was established to analyze the role of circ_0003602 in CRC tumor growth in vivo. Results: Circ_0003602 was upregulated in CRC tissues and cell lines. Circ_0003602 silencing suppressed CRC cell viability, migration, invasion, angiogenesis, and glutaminolysis; induced cell apoptosis in vitro; and blocked tumor growth in vivo. Moreover, circ_0003602 directly interacted with miR-149-5p to negatively regulate its expression, and circ_0003602 knockdown suppressed the malignant behaviors of CRC cells largely by upregulating miR-149-5p. MiR-149-5p directly bound to the 3’ untranslated region of SLC38A1 to induce its degradation, and miR-149-5p overexpression reduced the malignant potential of CRC cells largely by downregulating SLC38A1. Circ_0003602 positively regulated SLC38A1 expression by sponging miR-149-5p in CRC cells. Conclusions: Circ_0003602 knockdown impedes CRC development by targeting the miR-149- 5p/SLC38A1 axis, which provides a novel theoretical basis and new insights for CRC treatment.

Structural and Optical Properties of Copper Indium Gallium Selenide Thin Films Prepared by RF Magnetron Sputtering

Seon Mi Kong,Rong Fan,Dong Chan Kim,Chee Won Chung 한국진공학회 2011 한국진공학회 학술발표회초록집 Vol.40 No.0