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The Mechanism of Action of Ghrelin and Motilin in the Pacemaker Potentials of Interstitial Cells of Cajal from the Murine Small Intestine

  • Kim, Jeong Nam;Kim, Byung Joo
    • Molecules and Cells
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    • v.42 no.6
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    • pp.470-479
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    • 2019
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that exhibit periodic spontaneous depolarization in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of ghrelin and motilin on the pacemaker potentials of ICCs isolated from the mouse small intestine. Using the whole-cell patch-clamp configuration, we demonstrated that ghrelin depolarized pacemaker potentials of cultured ICCs in a dose-dependent manner. The ghrelin receptor antagonist [D-Lys] GHRP-6 completely inhibited this ghrelin-induced depolarization. Intracellular guanosine 5'-diphosphate-${\beta}$-S and pre-treatment with $Ca^{2+}$-free solution or thapsigargin also blocked the ghrelin-induced depolarization. To investigate the involvement of inositol triphosphate ($IP_3$), Rho kinase, and protein kinase C (PKC) in ghrelin-mediated pacemaker potential depolarization of ICCs, we used the $IP_3$ receptor inhibitors 2-aminoethoxydiphenyl borate and xestospongin C, the Rho kinase inhibitor Y-27632, and the PKC inhibitors staurosporine, Go6976, and rottlerin. All inhibitors except rottlerin blocked the ghrelin-induced pacemaker potential depolarization of ICCs. In addition, motilin depolarized the pacemaker potentials of ICCs in a similar dose-dependent manner as ghrelin, and this was also completely inhibited by [D-Lys] GHRP-6. These results suggest that ghrelin induced the pacemaker potential depolarization through the ghrelin receptor in a G protein-, $IP_3$-, Rho kinase-, and PKC-dependent manner via intracellular and extracellular $Ca^{2+}$ regulation. In addition, motilin was able to depolarize the pacemaker potentials of ICCs through the ghrelin receptor. Therefore, ghrelin and its receptor may modulate GI motility by acting on ICCs in the murine small intestine.

Immunotherapy for Non-small Cell Lung Cancer: Current Landscape and Future Perspectives

  • Sun Min Lim;Min Hee Hong;Hye Ryun Kim
    • IMMUNE NETWORK
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    • v.20 no.1
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    • pp.10.1-10.14
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    • 2020
  • Immune checkpoint inhibitors (ICIs) have shown remarkable benefit in the treatment of patients with non-small-cell lung cancer (NSCLC) and have emerged as an effective treatment option even in the first-line setting. ICIs can block inhibitory pathways that restrain the immune response against cancer, restoring and sustaining antitumor immunity. Currently, there are 4 PD-1/PD-L1 blocking agents available in clinics, and immunotherapy-based regimen alone or in combination with chemotherapy is now preferred option. Combination trials assessing combination of ICIs with chemotherapy, targeted therapy and other immunotherapy are ongoing. Controversies remain regarding the use of ICIs in targetable oncogene-addicted subpopulations, but their initial treatment recommendations remained unchanged, with specific tyrosine kinase inhibitors as the choice. For the majority of patients without targetable driver oncogenes, deciding between therapeutic options can be difficult due to lack of direct cross-comparison studies. There are continuous efforts to find predictive biomarkers to find those who respond better to ICIs. PD-L1 protein expressions by immunohistochemistry and tumor mutational burden have emerged as most well-validated biomarkers in multiple clinical trials. However, there still is a need to improve patient selection, and to establish the most effective concurrent or sequential combination therapies in different NSCLC clinical settings. In this review, we will introduce currently used ICIs in NSCLC and analyze most recent trials, and finally discuss how, when and for whom ICIs can be used to provide promising avenues for lung cancer treatment.

Effects of Gintonin-enriched fraction on the gene expression of six lysophosphatidic receptor subtypes

  • Lee, Rami;Lee, Byung-Hwan;Choi, Sun-Hye;Cho, Yeon-Jin;Cho, Han-Sung;Kim, Hyoung-Chun;Rhim, Hyewhon;Cho, Ik-Hyun;Rhee, Man Hee;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.45 no.5
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    • pp.583-590
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    • 2021
  • Background: Gintonin, isolated from ginseng, acts as a ginseng-derived lysophosphatidic acid (LPA) receptor ligand and elicits the [Ca2+]i transient through six LPA receptor subtypes (LPARSs). However, the long-term effects of gintonin-enriched fraction (GEF) on the gene expression of six LPARSs remain unknown. We examined changes in the gene expression of six LPA receptors in the mouse whole brain, heart, lungs, liver, kidneys, spleen, small intestine, colon, and testis after long-term oral GEF administration. Methods: C57BL/6 mice were divided into two groups: control vehicle and GEF (100 mg/kg, p.o.). After 21-day saline or GEF treatment, total RNA was extracted from nine mouse organs. Quantitative-real-time PCR (qRT-PCR) and western blot were performed to quantify changes in the gene and protein expression of the six LPARSs, respectively. Results: qRT-PCR analysis before GEF treatment revealed that the LPA6 RS was predominant in all organs except the small intestine. The LPA2 RS was most abundant in the small intestine. Long-term GEF administration differentially regulated the six LPARSs. Upon GEF treatment, the LPA6 RS significantly increased in the liver, small intestine, colon, and testis but decreased in the whole brain, heart, lungs, and kidneys. Western blot analysis of the LPA6 RS confirmed the differential effects of GEF on LPA6 receptor protein levels in the whole brain, liver, small intestine, and testis. Conclusion: The LPA6 receptor was predominantly expressed in all nine organs examined; long-term oral GEF administration differentially regulated LPA3, LPA4, and LPA6 receptors in the whole brain, heart, lungs, liver, kidneys, small intestine, and testis.

The Effects of Seed Size on the Early Seedling Growth and Yield of Three Soybean(Glycine max. L.) Cultivars (대두종자(大豆種子)의 대소(大小)가 초기생육(初期生育) 및 수량(收量)에 미치는 영향(影響))

  • Park, Ki Sun;Choi, Chang Yeol;Kang, Jea Chul
    • Korean Journal of Agricultural Science
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    • v.16 no.2
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    • pp.138-151
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    • 1989
  • In order to find the effects of seed size on the early seedling growth and yield of soybean, three soybean cultivars in Korea were investigated. Seed size was classified into large and small according to the weight and planted in pots(1/5000a) and in the field. Three soybean cultivars respresenting large, medium and small grains were Hwangkeum-kong, Kwangkyo and Bangsa-kong respectively. These cultivars were planted on June 20, 1987. 1. The plant height, stem diameter, root length and leaf area index(LAI) of the seed with large size seemed larger than the seed with small size regardless of cultivars. 2. The fresh and dry weight were different depending upon the grain sizes. The large grain had heavier fresh and dry weight than the small grains. 3. The protein consumption rate of the cotyledon of Bangsa-kong with small grain size was faster than the Hwangkeum-kong with large grain size. 4. The stem length, stem diameter and number of main stem node of the seed with large size seemed larger than the seed with small size. Large grains of Hwangkeum-kong were the highest in the number of branch node and number of node. 5. The number of pods and grains per plant of Bangsa-kong with small grain size was larger than the Kwangkyo with large grain size. 6. The yield per 10a for Hwangkeum-kong, Hwangkyo and Bangsa-kong were 226.3kg, 193.0kg and 192.8kg, respectively and they were all statistically different. The yield increases of large grains over small grains in the Hwangkeum-kong, Kwangkyo, and Bangsa-kong were 7.4%, 8.0% and 9.2%, respectively.

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Effect of 5-aza-2'-deoxycytidine on Cell Proliferation of Non-small Cell Lung Cancer Cell Line A549 Cells and Expression of the TFPI-2 Gene

  • Dong, Yong-Qiang;Liang, Jiang-Shui;Zhu, Shui-Bo;Zhang, Xiao-Ming;Ji, Tao;Xu, Jia-Hang;Yin, Gui-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4421-4426
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    • 2013
  • Objective: The present study employed 5-aza-2'-deoxycytidine (5-Aza-CdR) to treat non-small cell lung cancer (NSCLC) cell line A549 to investigate the effects on proliferation and expression of the TFPI-2 gene. Methods: Proliferation was assessed by MTT assay after A549 cells were treated with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR, a specific demethylating agent, for 24, 48 and 72h. At the last time point cells were also analyzed by flow cytometry (FCM) to identify any change in their cell cycle profiles. Methylation-specific polymerase chain reaction (MSPCR), real time polymerase chain reaction(real-time PCR) and western blotting were carried out to determine TFPI-2 gene methylation status, mRNA expression and protein expression. Results: MTT assay showed that the growth of A549 cells which were treated with 5-Aza-CdR was significantly suppressed as compared with the control group (0 ${\mu}mol/L$ 5-Aza-CdR). After treatment with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h, FCM showed their proportion in G0/G1 was $69.7{\pm}0.99%$, $76.1{\pm}0.83%$, $83.8{\pm}0.35%$, $95.5{\pm}0.55%$ respectively (P<0.05), and the proportion in S was $29.8{\pm}0.43%$, $23.7{\pm}0.96%$, $15.7{\pm}0.75%$, $1.73{\pm}0.45%$, respectively (P<0.05), suggesting 5-Aza-CdR treatment induced G0/G1 phase arrest. MSPCR showed that hypermethylation in the promoter region of TFPI-2 gene was detected in control group (0 ${\mu}mol/L$ 5-Aza-CdR), and demethylation appeared after treatment with 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h. Real-time PCR showed that the expression levels of TFPI-2 gene mRNA were $1{\pm}0$, $1.49{\pm}0.14$, $1.86{\pm}0.09$ and $5.80{\pm}0.15$ (P<0.05) respectively. Western blotting analysis showed the relative expression levels of TFPI-2 protein were $0.12{\pm}0.01$, $0.23{\pm}0.02$, $0.31{\pm}0.02$, $0.62{\pm}0.03$ (P<0.05). TFPI-2 protein expression in A549 cells was gradually increased significantly with increase in the 5-Aza-CdR concentration. Conclusions: TFPI-2 gene promoter methylation results in the loss of TFPI-2 mRNA and protein expression in the non-small cell lung cancer cell line A549, and 5-Aza-CdR treatment could induce the demethylation of TFPI-2 gene promoter and restore TFPI-2 gene expression. These findings provide theoretic evidence for clinical treatment of advanced non-small cell lung cancer with the demethylation agent 5-Aza-CdR. TFPI-2 may be one molecular marker for effective treatment of advanced non-small cell lung cancer with 5-Aza-CdR.

Recent insights into the role of ChREBP in intestinal fructose absorption and metabolism

  • Lee, Ho-Jae;Cha, Ji-Young
    • BMB Reports
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    • v.51 no.9
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    • pp.429-436
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    • 2018
  • Fructose in the form of sucrose and high fructose corn syrup is absorbed by the intestinal transporter and mainly metabolized in the small intestine. However, excess intake of fructose overwhelms the absorptive capacity of the small intestine, leading to fructose malabsorption. Carbohydrate response element-binding protein (ChREBP) is a basic helix-loop-helix leucine zipper transcription factor that plays a key role in glycolytic and lipogenic gene expression in response to carbohydrate consumption. While ChREBP was initially identified as a glucose-responsive factor in the liver, recent evidence suggests that ChREBP is essential for fructose-induced lipogenesis and gluconeogenesis in the small intestine as well as in the liver. We recently identified that the loss of ChREBP leads to fructose intolerance via insufficient induction of genes involved in fructose transport and metabolism in the intestine. As fructose consumption is increasing and closely associated with metabolic and gastrointestinal diseases, a comprehensive understanding of cellular fructose sensing and metabolism via ChREBP may uncover new therapeutic opportunities. In this mini review, we briefly summarize recent progress in intestinal fructose metabolism, regulation and function of ChREBP by fructose, and delineate the potential mechanisms by which excessive fructose consumption may lead to irritable bowel syndrome.

Cloning, Expression, and Characterization of a Thermostable GH51 ${\alpha}-\small{L}$-Arabinofuranosidase from Paenibacillus sp. DG-22

  • Lee, Sun Hwa;Lee, Yong-Eok
    • Journal of Microbiology and Biotechnology
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    • v.24 no.2
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    • pp.236-244
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    • 2014
  • The gene encoding ${\alpha}-\small{L}$-arabinofuranosidase (AFase) from Paenibacillus sp. DG-22 was cloned, sequenced, and expressed in Escherichia coli. The AFase gene (abfA) comprises a 1,509 bp open reading frame encoding 502 amino acids with a molecular mass of 56,520 daltons. The deduced amino acid sequence of the gene shows that AbfA is an enzyme consisting of only a catalytic domain, and that the enzyme has significant similarity to AFases classified into the family 51 of the glycosyl hydrolases. abfA was subcloned into the pQE60 expression vector to fuse it with a six-histidine tag and the recombinant AFase (rAbfA) was purified to homogeneity. The specific activity of the recombinant enzyme was 96.7 U/mg protein. Determination of the apparent molecular mass by gel-filtration chromatography indicated that AbfA has a tetrameric structure. The optimal pH and temperature of the enzyme were 6.0 and $60^{\circ}C$, respectively. The enzyme activity was completely inhibited by 1 mM $HgCl_2$. rAbfA was active only towards p-nitrophephenyl ${\alpha}-\small{L}$-arabinofuranoside and exhibited $K_m$ and $V_{max}$ values of 3.5 mM and 306.1 U/mg, respectively. rAbfA showed a synergistic effect in combination with endoxylanase on the degradation of oat spelt xylan and wheat arabinoxylan.

Utilization of Sunflower Crop Residues as Feed in Small Ruminants

  • Rasool, Ejaz;Khan, M.F.;Nawaz, M.;Rafiq, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.3
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    • pp.272-276
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    • 1998
  • Sheep and goats in Pakistan have not been able to produce to the best of their potential. This may primarily be attributed to under feeding and malnutrition. Ranges have been depleted due to overgrazing and mismanagement and are not in position to feed the existing small ruminant population. To overcome the shortage of good quality fodder and balanced feed supply, the alternate means like cereal straws and other crop residues are being commonly used. Sunflower crop residues like stalks and heads provide a good quality forage for livestock. These crop byproducts are rich in crude protein and lower in crude fibre. Their inclusion in the diet of small ruminants at 20, 30 and 40 percent levels in ration has shown significantly (p < 0.05) increased feed intake and weight gain. Daily feed intake was 1,130, 1,180 and 1,750 g for sunflower crop residue, soybean crop residue and wheat straw, respectively, when added at the rate of 20 percent in the ration. The drymatter digestibility of sunflower, soybean crop residues and wheat straw was also comparable. The maximum performance of the animals was observed at the 20 percent level of inclusion of sunflower crop residue in the diet.

EFFECT OF SUPPLEMENTATION AND PARASITIC INFECTION ON PRODUCTIVITY OF THAI NATIVE AND CROSS-BRED FEMALE WEANER GOATS I. GROWTH, PARASITE INFESTATION AND BLOOD CONSTITUENTS

  • Pralomkarn, W.;Kochapakdee, S.;Choldumrongkul, S.;Saithanoo, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.4
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    • pp.547-554
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    • 1994
  • This paper presents the effects of supplementary feeding and internal parasites on the growth rates of female weaner goats raised under improved management. A completely randomized $3{\times}3{\times}2$ factorial design was used. Factors were genotype (Thai native: TN, 75% TN $\times$ 25% Anglo-Nubian: An and 50% TN $\times$ 50% AN), feeding grazing only, low (1.0% BW/d) and high (1.5% BW/d) supplementation and parasite control (undrenched and drenched). It was shown that native goats had significantly (p<0.05) higher growth rates than did the cross-bred goats from 12-24 weeks of the trial. The growth rate of goats grazing improved pasture depended on the amount of concentrate offered as a supplement. There was no significant difference in growth rates between undrenched and drenched goats. There was no interaction effect on growth rates between the treatments. Drenched goats had significantly (p<0.01) lower egg counts per gram of gastro-intestinal nematode than did undrenched goats. There was no significant difference between the treatments for blood constituents (total protein, haemoglobin, packed cell volume, eosinophils, lymphocytes, monocytes and basophils).

Soluble Expression of a Human MnSOD and Hirudin Fusion Protein in Escherichia coli, and Its Effects on Metastasis and Invasion of 95-D Cells

  • Yi, Shanze;Niu, Dewei;Bai, Fang;Li, Shuaiguang;Huang, Luyuan;He, Wenyan;Prasad, Anand;Czachor, Alexander;Tan, Lee Charles;Kolliputi, Narasaiah;Wang, Feng
    • Journal of Microbiology and Biotechnology
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    • v.26 no.11
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    • pp.1881-1890
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    • 2016
  • Manganese superoxide dismutase (MnSOD) is a vital enzyme that protects cells from free radicals through eliminating superoxide radicals ($O^{2-}$). Hirudin, a kind of small active peptide molecule, is one of the strongest anticoagulants that can effectively cure thrombus diseases. In this study, we fused Hirudin to the C terminus of human MnSOD with the GGGGS linker to generate a novel dual-feature fusion protein, denoted as hMnSOD-Hirudin. The hMnSOD-Hirudin gene fragment was cloned into the pET15b (SmaI, CIAP) vector, forming a recombinant pET15b-hMnSOD-Hirudin plasmid, and then was transferred into Escherichia coli strain Rosetta-gami for expression. SDS-PAGE was used to detect the fusion protein, which was expected to be about 30 kDa upon IPTG induction. Furthermore, the hMnSOD-Hirudin protein was heavily detected as a soluble form in the supernatant. The purification rate observed after Ni NTA affinity chromatography was above 95%. The hMnSOD-Hirudin protein yield reached 67.25 mg per liter of bacterial culture. The identity of the purified protein was confirmed by western blotting. The hMnSOD-Hirudin protein activity assay evinced that the antioxidation activity of the hMnSOD-Hirudin protein obtained was $2,444.0{\pm}96.0U/mg$, and the anticoagulant activity of the hMnSOD-Hirudin protein was $599.0{\pm}35.0ATU/mg$. In addition, in vitro bioactivity assay showed that the hMnSOD-Hirudin protein had no or little cytotoxicity in H9c2, HK-2, and H9 (human $CD_4{^+}$, T cell) cell lines. Transwell migration assay and invasion assay showed that the hMnSOD-Hirudin protein could suppress human lung cancer 95-D cell metastasis and invasion in vitro.