1
|
Kim M, Jeong M, Hur S, Cho Y, Park J, Jung H, Seo Y, Woo HA, Nam KT, Lee K, Lee H. Engineered ionizable lipid nanoparticles for targeted delivery of RNA therapeutics into different types of cells in the liver. Sci Adv 2021; 7:7/9/eabf4398. [PMID: 33637537 PMCID: PMC7909888 DOI: 10.1126/sciadv.abf4398] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 05/08/2023]
Abstract
Ionizable lipid nanoparticles (LNPs) have been widely used for in vivo delivery of RNA therapeutics into the liver. However, a main challenge remains to develop LNP formulations for selective delivery of RNA into certain types of liver cells, such as hepatocytes and liver sinusoidal endothelial cells (LSECs). Here, we report the engineered LNPs for the targeted delivery of RNA into hepatocytes and LSECs. The effects of particle size and polyethylene glycol-lipid content in the LNPs were evaluated for the hepatocyte-specific delivery of mRNA by ApoE-mediated cellular uptake through low-density lipoprotein receptors. Targeted delivery of RNA to LSECs was further investigated using active ligands. Incorporation of mannose allowed the selective delivery of RNA to LSECs, while minimizing the unwanted cellular uptake by hepatocytes. These results demonstrate that engineered LNPs have great potential for the cell type-specific delivery of RNA into the liver and other tissues.
Collapse
Affiliation(s)
- M Kim
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
| | - M Jeong
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
| | - S Hur
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - Y Cho
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - J Park
- Fluorescence Core Imaging Center, Ewha Womans University, Seoul 120-750, South Korea
| | - H Jung
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
| | - Y Seo
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
| | - H A Woo
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
| | - K T Nam
- Severance Biomedical Science Institute, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, South Korea
| | - K Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, South Korea
| | - H Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea.
| |
Collapse
|
2
|
Park JS, Kim JI, Lim HJ, Ryu SK, Kwon E, Han KM, Nam KT, Lee HW, Kang BC. Differential manifestation of ocular phenotypes in TALEN-mediated p19 arf knockout FVB/N and C57BL/6J mouse lines. Genes Genomics 2020; 42:1023-1033. [PMID: 32712838 DOI: 10.1007/s13258-020-00959-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 06/09/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND p19arf, primarily known as a tumor suppressor, has also been reported to play an essential role in normal development of mouse eyes. Consistently, lack of p19arf has been associated with ocular defects, but the mixed background of the knockout (KO) mouse strain used raised a concern on the accuracy of the phenotypes observed in association with the targeted gene due to genetic heterogeneity. OBJECT We carried out a study to investigate into the effect of genetic background on the manifestation of p19arf KO associated phenotypes. METHODS We characterized the phenotypes of novel p19arf KO mouse lines generated in FVB/N and C57BL/6J using a transcription activator-like effector nuclease (TALEN) system in comparison to the reported phenotypes of three other p19arf-deficient mouse lines generated using homologous recombination. RESULTS Ninety-five percent of FVB/N-p19arf KO mice showed ocular opacity from week 4 after birth which worsened rapidly until week 6, while such abnormality was absent in C57BL/6J-p19arf KO mice up to the age of 26 weeks. Histopathological analysis revealed retrolental masses and dysplasia in the retinal layer in FVB/N-p19arf KO mice from week 4. Besides these, both strains developed normally from birth to week 26 without increased tumorigenesis except for a subcutaneous tumor found in a C57BL/6J-p19arf KO mouse. CONCLUSION Our findings demonstrated surprisingly variable manifestation of p19arf-linked phenotypes between FVB/N and C57BL/6J mice, and furthermore between our mouse lines and the established lines, indicating a critical impact of genetic background on functional study of genes using gene targeting strategies in mice.
Collapse
Affiliation(s)
- Jin-Sung Park
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Joo-Il Kim
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyun-Jin Lim
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Soo-Kyung Ryu
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Euna Kwon
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kang-Min Han
- Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Pathology, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Ki-Taek Nam
- College of Medicine Severance Biomedical Science Institute, Yonsei University, Seoul, Republic of Korea
| | - Han-Woong Lee
- Department of Biochemistry, Yonsei University, Seoul, Republic of Korea
| | - Byeong-Cheol Kang
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea. .,Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Biomedical Center for Animal Resource and Development, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Designed Animal Resource Center, Institute of GreenBio Science and Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea.
| |
Collapse
|
3
|
Lee E, Nam KT, Lee KW, Lee SR. Pediococcus spp.-fermented chicken meat for dogs. J Anim Sci Technol 2020; 62:84-93. [PMID: 32082602 PMCID: PMC7008127 DOI: 10.5187/jast.2020.62.1.84] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/20/2019] [Accepted: 12/31/2019] [Indexed: 11/30/2022]
Abstract
An experiment was conducted to evaluate Pediococcus
spp.-fermented chicken meat as a snack for dogs. The fermented or non-fermented
snacks used in this study were prepared through the following process; meat
mixtures containing 52.8% MDCM, 35.2% chicken breast meat (CBM) and 9.7% corn
starch were inoculated with or without Pediococcus spp.,
incubated at 37°C for 24 h and then sterilized at 121°C for 20
min. During the 24-h fermentation, the pH of fermented chicken snack dropped
rapidly with concomitant increase in number of lactic acid bacteria. The
nutritional composition was not altered by fermentation. In
vitro pepsin nitrogen digestibility was higher (p
< 0.05) in the fermented snack compared with the non-fermented snack.
Upon storage at room temperature for 14 days, bacteria grew slowly in fermented
vs. non-fermented snack samples. In a palatability trial, dogs preferred
non-fermented over fermented snack food. In 12-d-long feeding trial, fecal
ammonia content was lowered, but fecal lactic acid content was increased in dogs
fed the fermented vs. non-fermented snack food. Our study shows that the
fermented MDCM-based snack exhibited good preservability upon storage, and
improved in vitro nitrogen digestibility and fecal
characteristics in dogs.
Collapse
Affiliation(s)
- Eunchae Lee
- Department of Animal Science and Technology, Konkuk University, Seoul 05029, Korea
| | - Ki-Taek Nam
- Department of Animal Life and Environment Science, Hankyong National University, Anseong 17579, Korea
| | - Kyung-Woo Lee
- Department of Animal Science and Technology, Konkuk University, Seoul 05029, Korea
| | - Sang-Rak Lee
- Department of Animal Science and Technology, Konkuk University, Seoul 05029, Korea
| |
Collapse
|
4
|
Kim JI, Park JS, Kwak J, Lim HJ, Ryu SK, Kwon E, Han KM, Nam KT, Lee HW, Kang BC. CRISPR/Cas9-mediated knockout of CD47 causes hemolytic anemia with splenomegaly in C57BL/6 mice. Lab Anim Res 2018; 34:302-310. [PMID: 30671119 PMCID: PMC6333621 DOI: 10.5625/lar.2018.34.4.302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 11/29/2022] Open
Abstract
CD47 (integrin-associated protein), a multi-spanning transmembrane protein expressed in all cells including red blood cells (RBCs) and leukocytes, interacts with signal regulatory protein α (SIRPα) on macrophages and thereby inhibits phagocytosis of RBCs. Recently, we generated a novel C57BL/6J CD47 knockout (CD47 -/- hereafter) mouse line by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease, and here report their hematological phenotypes. On monitoring their birth and development, CD47 -/- mice were born viable with a natural male-to-female sex ratio and normally developed from birth through puberty to adulthood without noticeable changes in growth, food/water intake compared to their age and sex-matched wild-type littermates up to 26 weeks. Hematological analysis revealed a mild but significant reduction of RBC counts and hemoglobin in 16 week-old male CD47 -/- mice which were aggravated at the age of 26 weeks with increased reticulocyte counts and mean corpuscular volume (MCV), suggesting hemolytic anemia. Interestingly, anemia in female CD47 -/- mice became evident at 26 weeks, but splenomegaly was identified in both genders of CD47 -/- mice from the age of 16 weeks, consistent with development of hemolytic anemia. Additionally, helper and cytotoxic T cell populations were considerably reduced in the spleen, but not in thymus, of CD47 -/- mice, suggesting a crucial role of CD47 in proliferation of T cells. Collectively, these findings indicate that our CD47 -/- mice have progressive hemolytic anemia and splenic depletion of mature T cell populations and therefore may be useful as an in vivo model to study the function of CD47.
Collapse
Affiliation(s)
- Joo-Il Kim
- Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jin-Sung Park
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jina Kwak
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Hyun-Jin Lim
- Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Soo-Kyung Ryu
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Euna Kwon
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Kang-Min Han
- Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Pathology, Dongguk University Ilsan Hospital, Goyang, Korea
| | - Ki-Taek Nam
- College of Medicine Severance Biomedical Science Institute, Yonsei University, Seoul, Korea
| | - Han-Woong Lee
- Department of Biochemistry, Yonsei University, Seoul, Korea
| | - Byeong-Cheol Kang
- Graduate School of Translational Medicine, Seoul National University College of Medicine, Seoul, Korea
- Department of Experimental Animal Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Biomedical Center for Animal Resource and Development, Seoul National University, College of Medicine, Seoul, Korea
- Designed Animal and Transplantation Research Institute, Institute of Green Bio Science Technology, Seoul National University, Pyeongchang-gun, Korea
| |
Collapse
|
5
|
Lee JH, Cho S, Paik HD, Choi CW, Nam KT, Hwang SG, Kim SK. Investigation on antibacterial and antioxidant activities, phenolic and flavonoid contents of some thai edible plants as an alternative for antibiotics. Asian-Australas J Anim Sci 2014; 27:1461-8. [PMID: 25178298 PMCID: PMC4150179 DOI: 10.5713/ajas.2013.13629] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 01/24/2014] [Accepted: 05/01/2014] [Indexed: 11/27/2022]
Abstract
This study was aimed to examine the antibacterial and antioxidative properties of seven edible plants from Thailand to develop alternative antibiotics as feed additives. The plants include Citrus aurantifolia Swingle (Lime) fruits and its leaves, Sesbania grandiflora L. (Agati sesbania) leaves, Piper sarmentosum Roxb (Wild betal) leaves, Curcuma domestica Valeton (Turmeric) roots, Morinda citrifolia L. (Beach mulberry) leaves, Cassia siamea britt (Siamea cassia) leaves, and Cocos nucifera L. (Coconut) peels. The plants were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. Antibacterial activities with minimum inhibitory concentration (MIC) were determined by agar diffusion assay against Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, and Clostridium perfringens that were considered pathogenic strains in livestock infection. Methanol extracts of C. aurantifolia Swingle fruits and leaves showed the broadest spectrum of antibacterial activities except for C. perfringens. Butanol extract of S. grandiflora L. leaves showed the strongest activity against Burkholderia sp. with MIC, 135 μg/mL. P. sarmentosum Roxb leaves showed antibacterial activities against E. coli, Burkholderia sp. and H. parasuis. Ethyl acetate and water extracts from C. domesitca Valeton roots showed MIC of 306 μg/mL and 183 μg/mL, respectively against only C. perfringens. Antioxidative activity was determined by 2-diphenyl-2-picryl hydrazyl photometric assay. The methanol extracts of C. aurantifolia Swingle fruits and P. sarmentosum Roxb leaves showed the highest antioxidant activity among all the extracts with 3.46 mg/mL and 2.70 mg/mL effective concentration 50% (EC50) values, respectively. Total contents of phenolics and flavonoids were measured from the plant extracts. Methanol extracts of S. grandiflora L. and chloroform extracts of C. domestica Valeton were found to have the highest amount of total phenolics, 41.7 and 47.8 μg/mL, respectively. Flavonoid content of methanol extracts in S. grandiflora L. T was 22.5 μg/mL and the highest among plant extracts tested. These results indicated that C. aurantifolia Swingle, S. grandiflora L., P. sarmentosum Roxb, and C. domestica Valeton have antibacterial and antioxidant activities and can be used as alternative antibiotics or potential feed additives for the control of animal pathogenic bacteria.
Collapse
Affiliation(s)
- J H Lee
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 143-701, Korea
| | - S Cho
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 143-701, Korea
| | - H D Paik
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 143-701, Korea
| | - C W Choi
- Department of Biology and Medicinal Science, Paichai University, Daejeon 302-735, Korea
| | - K T Nam
- Division of Animal Life and Environmental Science, Hankyong National University, Anseong 456-749, Korea
| | - S G Hwang
- Division of Animal Life and Environmental Science, Hankyong National University, Anseong 456-749, Korea
| | - S K Kim
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 143-701, Korea
| |
Collapse
|
6
|
Al-Youssef HM, Amina M, Hassan S, Amna T, Jeong JW, Nam KT, Kim HY. Herbal drug loaded poly(D,L-lactide-co-glycolide) ultrafine fibers: Interaction with pathogenic bacteria. Macromol Res 2013. [DOI: 10.1007/s13233-013-1062-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
7
|
Jee H, Lee SH, Park JW, Lee BR, Nam KT, Kim DY. Connexin32 inhibits gastric carcinogenesis through cell cycle arrest and altered expression of p21Cip1 and p27Kip1. BMB Rep 2013; 46:25-30. [PMID: 23351380 PMCID: PMC4133826 DOI: 10.5483/bmbrep.2013.46.1.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 06/04/2012] [Accepted: 08/10/2012] [Indexed: 01/22/2023] Open
Abstract
Gap junctions and their structural proteins, connexins (Cxs), have been implicated in carcinogenesis. To explore the involvement of Cx32 in gastric carcinogenesis, immunochemical analysis of Cx32 and proliferation marker Ki67 using tissue-microarrayed human gastric cancer and normal tissues was performed. In addition, after Cx32 overexpression in the human gastric cancer cell line AGS, cell proliferation, cell cycle analyses, and p21(Cip1) and p27(Kip1) expression levels were examined by bromodeoxyuridine assay, flow cytometry, real-time RT-PCR, and western blotting. Immunohistochemical study noted a strong inverse correlation between Cx32 and Ki67 expression pattern as well as their location. In vitro, overexpression of Cx32 in AGS cells inhibited cell proliferation significantly. G1 arrest, up-regulation of cell cycle-regulatory proteins p21(Cip1) and p27(Kip1) was also found at both mRNA and protein levels. Taken together, Cx32 plays some roles in gastric cancer development by inhibiting gastric cancer cell proliferation through cell cycle arrest and cell cycle regulatory proteins.
Collapse
Affiliation(s)
- Hyang Jee
- Department of Veterinary Pathology and Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
| | - Su-Hyung Lee
- Department of Veterinary Pathology and Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
| | - Jun-Won Park
- Department of Veterinary Pathology and Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
| | - Bo-Ram Lee
- Department of Veterinary Pathology and Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
| | - Ki-Taek Nam
- Nashville Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, Nashville, Tennessee, 37232-2733, USA
| | - Dae-Yong Kim
- Department of Veterinary Pathology and Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
| |
Collapse
|
8
|
Amna T, Hassan MS, Nam KT, Bing YY, Barakat NAM, Khil MS, Kim HY. Preparation, characterization, and cytotoxicity of CPT/Fe₂O₃-embedded PLGA ultrafine composite fibers: a synergistic approach to develop promising anticancer material. Int J Nanomedicine 2012; 7:1659-70. [PMID: 22615530 PMCID: PMC3357050 DOI: 10.2147/ijn.s24467] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to fabricate camptothecin/iron(III) oxide (CPT/Fe2O3)-loaded poly(D,L-lactide-co-glycolide) (PLGA) composite mats to modulate the CPT release and to improve the structural integrity and antitumor activity of the released drug. The CPT/Fe2O3-loaded PLGA ultrafine fibers were prepared for the first time by electrospinning a composite solution of CPT/Fe2O3 and neat PLGA (4 weight percent). The physicochemical characterization of the electrospun composite mat was carried out by scanning electron microscopy, energy dispersive X-ray spectroscopy, electron probe microanalysis, thermogravimetry, transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray diffraction pattern. The medicated composite fibers were evaluated for their cytotoxicity on C2C12 cells using Cell Counting Kit-8 assay (Sigma-Aldrich Corporation, St Louis, MO). The in vitro studies indicated a slow and prolonged release over a period of 96 hours with mild initial burst. Scanning electron microscopy, thermogravimetry, and X-ray diffraction studies confirmed the interaction of CPT/Fe2O3 with the PLGA matrix and showed that the crystallinity of CPT decreased after loading. Incorporation of CPT in the polymer media affected both the morphology and the size of the CPT/Fe2O3-loaded PLGA composite fibers. Electron probe microanalysis and energy dispersive X-ray spectroscopy results confirmed well-oriented composite ultrafine fibers with good incorporation of CPT/Fe2O3. The cytotoxicity results illustrate that the pristine PLGA did not exhibit noteworthy cytotoxicity; conversely, the CPT/Fe2O3 composite fibers inhibited C2C12 cells significantly. Thus, the current work demonstrates that the CPT/Fe2O3-loaded PLGA composite fibers represent a promising chemotherapeutic system for enhancing anticancer drug efficacy and selectively targeting cancer cells in order to treat diverse cancers.
Collapse
Affiliation(s)
- Touseef Amna
- Center for Healthcare Technology Development, Chonbuk National University, Jeonju, Korea
| | | | | | | | | | | | | |
Collapse
|
9
|
Baek WI, Pant HR, Nirmala R, Nam KT, Oh HJ, Kim HY. Mechanical property enhancement of non-bonding electrospun mats via adhesive. POLYM INT 2012. [DOI: 10.1002/pi.4153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
10
|
Kwon HJ, Won YS, Nam KT, Yoon YD, Jee H, Yoon WK, Nam KH, Kang JS, Han SU, Choi IP, Kim DY, Kim HC. Vitamin D₃ upregulated protein 1 deficiency promotes N-methyl-N-nitrosourea and Helicobacter pylori-induced gastric carcinogenesis in mice. Gut 2012; 61:53-63. [PMID: 21917648 DOI: 10.1136/gutjnl-2011-300361] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Vitamin D(3) upregulated protein 1 (VDUP1) is a potent tumour suppressor whose expression is dramatically reduced in various types of human cancers, including gastric cancer. However, the precise mechanisms underlying tumour development remain unclear. In the present study, the authors examined the effect of VDUP1 on Helicobacter pylori-induced gastric carcinogenesis in mice. DESIGN Gastric cancer was generated in VDUP1 knockout (KO) and wild-type mice using a combination of N-methyl-N-nitrosourea treatment and H pylori infection. Fifty weeks after treatment, gastric tissues from both types of mice were examined by histopathology, immunohistochemistry and immunoblotting. In vitro tests on the human gastric cancer cell line, AGS, were also performed to identify the underlying mechanisms of cancer development. RESULTS The overall incidence of gastric cancer was significantly higher in VDUP1 KO mice than in wild-type mice. Similarly, VDUP1 KO mice showed more severe chronic gastritis, glandular atrophy, foveolar hyperplasia, metaplasia and dysplasia. Although no differences in the apoptotic index were apparent, lack of VDUP1 increased the rate of gastric epithelial cell proliferation in non-cancerous stomachs, with corresponding increases in tumour necrosis factor alpha (TNFα) level, nuclear transcription factor kappa B (NF-κB) activation and cyclooxygenase-2 (COX-2) expression. An in vitro study showed that H pylori-associated cell proliferation and induction of TNFα, NF-κB and COX-2 were inhibited in cells transfected with VDUP1. In addition, overexpression of VDUP1 in AGS cells suppressed TNFα-induced NF-κB activation and COX-2 expression. CONCLUSION Our data show that VDUP1 negatively regulates H pylori-associated gastric carcinogenesis, in part by disrupting cell growth and inhibiting the induction of TNFα, NF-κB and COX-2. These findings provide important insights into the role of VDUP1 in H pylori-associated tumourigenesis.
Collapse
Affiliation(s)
- Hyo-Jung Kwon
- Biomedical Mouse Resource Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Pant HR, Nam KT, Oh HJ, Panthi G, Kim HD, Kim BI, Kim HY. Effect of polymer molecular weight on the fiber morphology of electrospun mats. J Colloid Interface Sci 2011; 364:107-11. [DOI: 10.1016/j.jcis.2011.07.094] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/28/2011] [Accepted: 07/30/2011] [Indexed: 10/17/2022]
|
12
|
|
13
|
Cho JK, Jung SJ, Joo EJ, Choi JY, Kim BS, Youn BS, Nam KT, Hwang SG. The Effects of Dietary Enzyme Mixture Fortified with β-Glucanase Activity on the Growth Performance, Serum Components, and Meat Quality of Broiler Chicks. Korean J Food Sci Anim Resour 2007. [DOI: 10.5851/kosfa.2007.27.4.409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
14
|
Que J, Okubo T, Goldenring JR, Nam KT, Kurotani R, Morrisey EE, Taranova O, Pevny LH, Hogan BLM. Multiple dose-dependent roles for Sox2 in the patterning and differentiation of anterior foregut endoderm. Development 2007; 134:2521-31. [PMID: 17522155 PMCID: PMC3625644 DOI: 10.1242/dev.003855] [Citation(s) in RCA: 381] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sox2 is expressed in developing foregut endoderm, with highest levels in the future esophagus and anterior stomach. By contrast, Nkx2.1 (Titf1) is expressed ventrally, in the future trachea. In humans, heterozygosity for SOX2 is associated with anopthalmia-esophageal-genital syndrome (OMIM 600992), a condition including esophageal atresia (EA) and tracheoesophageal fistula (TEF), in which the trachea and esophagus fail to separate. Mouse embryos heterozygous for the null allele, Sox2(EGFP), appear normal. However, further reductions in Sox2, using Sox2(LP) and Sox2(COND) hypomorphic alleles, result in multiple abnormalities. Approximately 60% of Sox2(EGFP/COND) embryos have EA with distal TEF in which Sox2 is undetectable by immunohistochemistry or western blot. The mutant esophagus morphologically resembles the trachea, with ectopic expression of Nkx2.1, a columnar, ciliated epithelium, and very few p63(+) basal cells. By contrast, the abnormal foregut of Nkx2.1-null embryos expresses elevated Sox2 and p63, suggesting reciprocal regulation of Sox2 and Nkx2.1 during early dorsal/ventral foregut patterning. Organ culture experiments further suggest that FGF signaling from the ventral mesenchyme regulates Sox2 expression in the endoderm. In the 40% Sox2(EGFP/COND) embryos in which Sox2 levels are approximately 18% of wild type there is no TEF. However, the esophagus is still abnormal, with luminal mucus-producing cells, fewer p63(+) cells, and ectopic expression of genes normally expressed in glandular stomach and intestine. In all hypomorphic embryos the forestomach has an abnormal phenotype, with reduced keratinization, ectopic mucus cells and columnar epithelium. These findings suggest that Sox2 plays a second role in establishing the boundary between the keratinized, squamous esophagus/forestomach and glandular hindstomach.
Collapse
Affiliation(s)
- Jianwen Que
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tadashi Okubo
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - James R. Goldenring
- Nashville VA Medical Center and the Departments of Surgery and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ki-Taek Nam
- Nashville VA Medical Center and the Departments of Surgery and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Reiko Kurotani
- Laboratory of Metabolism, NCI, NIH, Bethesda, MD 20892, USA
| | - Edward E. Morrisey
- Departments of Medicine and Cell and Developmental Biology, University of Pennsylvania, PA 19104, USA
| | - Olena Taranova
- Department of Genetics, University of North Carolina Neuroscience Center, University North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Larysa H. Pevny
- Department of Genetics, University of North Carolina Neuroscience Center, University North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brigid L. M. Hogan
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Author for correspondence ()
| |
Collapse
|
15
|
Nam KT, Kim DY, Park MS, Jang DD, Yang KH, Han JH, Yoon BI. Suppression of Cholangiocarcinoma Development by Aminoguanidine in the Liver Fluke-infested Hamster. J Toxicol Pathol 2005. [DOI: 10.1293/tox.18.65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Ki-Taek Nam
- National Institute of Toxicological Research, KFDA
| | - Dae-Yong Kim
- Department of Veterinary Pathology, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Mi-Sun Park
- Department of Veterinary Pathology, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | | | - Ki-Hwa Yang
- National Institute of Toxicological Research, KFDA
| | - Jeong-Hee Han
- Department of Veterinary Medicine, Kangwon National University
| | - Byung-Il Yoon
- Department of Veterinary Medicine, Kangwon National University
| |
Collapse
|
16
|
Nam KT, Oh SY, Ahn B, Kim YB, Jang DD, Yang KH, Hahm KB, Kim DY. Decreased Helicobacter pylori associated gastric carcinogenesis in mice lacking inducible nitric oxide synthase. Gut 2004; 53:1250-5. [PMID: 15306579 PMCID: PMC1774181 DOI: 10.1136/gut.2003.030684] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 01/26/2004] [Accepted: 02/19/2004] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS Overproduction of nitric oxide via inducible nitric oxide synthase (iNOS) is suggested to be a significant pathogenic factor in Helicobacter pylori induced gastritis. The purpose of this study was to examine the role of iNOS in H pylori associated gastric carcinogenesis. METHODS Two types of mice were used in this study: iNOS deficient mice (iNOS-/-) and wild-type littermates. Gastric cancer was generated in mice using a combination treatment comprising N-methyl-N-nitrosourea administration and H pylori infection. Fifty weeks after treatment, tumours in gastric tissues from both types of mice were examined using histopathology, immunohistochemistry, and immunoblotting for iNOS and 3-nitrotyrosine. RESULTS The overall incidence of gastric cancer at week 50 was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). When analysed according to tumour pathology, the incidence of gastric adenocarcinoma was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). Immunostaining for iNOS was clearly observed in adenocarcinoma cells of iNOS wild-type mice, and was characterised by a strong cytoplasmic expression pattern. 3-Nitrotyrosine was expressed mostly in the area of the lamina propria of gastritis and adenoma lesions in iNOS wild-type mice. Immunoblotting analyses showed that iNOS and 3-nitrotyrosine were also expressed in both adenoma and adenocarcinoma tissues from iNOS wild-type mice. iNOS and 3-nitrotyrosine expression was greater in tumour tissues than in non-tumour tissues. CONCLUSIONS These findings suggest that iNOS contributes to H pylori associated gastric carcinogenesis in mice.
Collapse
Affiliation(s)
- K T Nam
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Korea
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Kim BH, Won YS, Kim EY, Yoon M, Nam KT, Oh GT, Kim DY. Phenotype of peroxisome proliferator-activated receptor-alpha(PPARalpha)deficient mice on mixed background fed high fat diet. J Vet Sci 2003; 4:239-44. [PMID: 14685029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
Considerable controversy exists in determining the role of peroxisome proliferator-activated receptor-alpha PPARalpha) on obesity. Previous reports demonstrated that PPARalpha is a critical modulator of lipid homeostasis, but the overt, obese phenotypic characterization in the strain of PPAR deficient (PPARalpha-/-) mice is influenced by other factors, including diet and genetics. Therefore, it is necessary to establish the phenotypic characterization of PPARalpha-/- mice prior to the obesity-related study. In this study, we observed phenotype of PPARalpha-/- mice on mixed genetic background (C57BL/6Nx129/Sv) fed a high fat diet for 16 weeks. PPARalpha-/- mice, regardless of sex, raised body growth rate significantly comparing with wild type and showed male-specific fatty change in the liver. They were shown to lack hepatic induction of PPARalpha target genes encoding enzymes for fatty acid beta-oxidation.
Collapse
Affiliation(s)
- Bang Hyun Kim
- Department of Toxicology, National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul 122-704, Korea
| | | | | | | | | | | | | |
Collapse
|
18
|
Hahm KB, Kim DH, Lee KM, Lee JS, Surh YJ, Kim YB, Yoo BM, Kim JH, Joo HJ, Cho YK, Nam KT, Cho SW. Effect of long-term administration of rebamipide on Helicobacter pylori infection in mice. Aliment Pharmacol Ther 2003; 18 Suppl 1:24-38. [PMID: 12925138 DOI: 10.1046/j.1365-2036.18.s1.3.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND It has been suggested that chronic, persistent, uncontrolled inflammations in the stomach could provide the basic step for the beginning of carcinogenesis. One of the potential clinical applications of rebamipide is the inhibition of the immunoinflammatory response in gastric mucosa imposed by Helicobacter pylori. AIM To determine the implications of long-term rebamipide treatment in H. pylori infection, we studied the underlying moleculo-pathological changes in gastric lesions in mice infected with H. pylori (SS1 strain), following this treatment. METHODS C57BL/6 mice were sacrificed 24 and 50 weeks after H. pylori infection, respectively. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels of IL-1beta, TNF-alpha, IFN-gamma and IL-10, mRNA transcripts of various mouse cytokines and chemokines, and NF-kappaB binding activities, and finally the presence of gastric adenocarcinoma were compared between an H. pylori infected group (HP), and an H. pylori infected group administered with long-term rebamipide-containing pellet diets (HPR). RESULTS Serum levels of IL-1beta, IFN-gamma and TNF-alpha, the gastric mucosal expression of ICAM-1, HCAM and MMP, and transcriptional regulation of NF-kappaB-DNA binding were all significantly decreased in the HPR group compared with the HP group. An RNase protection assay showed, in the rebamipide administered group, significantly decreased mRNA levels of apoptosis-related genes such as caspase-8, FasL, Fas, TRAIL and various cytokines genes such as IFN-gamma, RANTES, TNF-alpha, TNFR p75, IL-1beta. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not different in either group. However, long-term administration of rebamipide showed the advantage of decreasing precancerous lesions like chronic atrophic gastritis and showed molecular evidence of attenuation of proliferation. CONCLUSION The long-term administration of rebamipide should be considered in the treatment of H. pylori since it demonstrated molecular and biological advantages like a lessening of gastric inflammation and a possible chemopreventive effect.
Collapse
Affiliation(s)
- K B Hahm
- Genomic Research Center for Gastroenterology, Ajou Helicobacter Research Group, Ajou University School of Medicine, Suwon, Korea.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Park KS, Kim HJ, Kim EJ, Nam KT, Oh JH, Song CW, Jung HK, Kim DJ, Yun YW, Kim HS, Chung SY, Cho DH, Kim BY, Hong JT. Effect of glycolic acid on UVB-induced skin damage and inflammation in guinea pigs. Skin Pharmacol Physiol 2002; 15:236-45. [PMID: 12218285 DOI: 10.1159/000065970] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Recently the use of glycolic-acid-containing cosmetics has received increased public interest in their supposed ability to reduce wrinkles, roughness, age spots and other skin damage. However, the safety of such products when used excessively or chronically, especially by photosensitive people, is being questioned. The purpose of this study was to examine the effects of glycolic acid alone or in combination with UVB on skin damage and inflammatory response. METHOD Guinea pigs were treated with glycolic acid (from 1 to 7 mg/cm(2)) alone or in combination with UVB (0.4 or 3 J/cm(2)) for 14 days. Skin damage was evaluated by scoring the skin irritation value by the method of Draize and by histopathological observations. Cyclooxygenase 2 (COX-2) expression and prostaglandin E(2) (PGE(2)) production were also assessed. RESULTS Glycolic acid caused an increase in the level of skin damage in a dose- and time-dependent manner. Lower doses (1 and 3 mg/cm(2)) of glycolic acid mostly caused erythema and eschar, and these consequently formed scales, whereas higher doses (5 and 7 mg/cm(2)) of glycolic acid caused redness, edema and necrotic ulceration. Glycolic acid also increased the thickness of the epidermal layer, reduced the organization of the stratum corneum and eventually destroyed some parts of the epidermal layer at 7 mg/cm(2). UVB (0.4 and 3 J/cm(2)) caused redness and edema as well as reduced the integrity of the stratum corneum. Glycolic acid enhanced the UVB-induced skin damage. The magnitude of the damage caused by combined UVB and glycolic acid treatment was much greater than that caused by glycolic acid or UVB alone. Moreover, partial destruction of the epidermal layer was observed in skin treated with 3 J/cm(2) UVB and 3 mg/cm(2) glycolic acid. However, glycolic acid did not change the basal and UVB-induced PGE(2) production and COX-2 protein expression. CONCLUSION These results show that glycolic acid causes skin damage in a dose- and time-dependent manner and that it enhances UVB-induced skin damage without accompanying PGE(2) production or COX-2 protein expression. Therefore, caution should be exercised by those using glycolic acid on a chronic basis or excessively. Moreover, those with photosensitive skins and those more exposed to the sun should be particularly careful.
Collapse
Affiliation(s)
- K S Park
- Department of General Toxicology, National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
The consumption of a cholesterol-enriched diet increases the degree of lipid peroxidation, which is one of the early processes of atherosclerosis. The aim of this trial was to determine the antioxidative effects of the citrus bioflavonoid, naringin, a potent cholesterol-lowering agent, compared to the cholesterol-lowering drug, lovastatin, in rabbits fed a high cholesterol diet. Male rabbits were served a high-cholesterol (0.5%, w/w) diet or high-cholesterol diet supplemented with either naringin (0.5% cholesterol, 0.05% naringin, w/w) or lovastatin (0.5% cholesterol, 0.03% lovastatin, w/w) for 8 weeks to determine the plasma and hepatic lipid peroxide, plasma vitamin A and E levels, and hepatic hydrogen peroxide levels, along with the hepatic antioxidant enzyme activities and gene expressions. Only the lovastatin group showed significantly lower plasma and hepatic lipid peroxide levels compared to the control group. The naringin supplementation significantly increased the activities of both hepatic SOD and catalase by 33% and 20%, respectively, whereas the lovastatin supplementation only increased the catalase activity by 23% compared to control group. There was no difference in the GSH-Px activities between the various groups. Content of H2O2 in hepatic mitochondria was significantly lower in groups supplemented with lovastatin and naringin than in control group. However, there was no difference in cytosolic H2O2 content in liver between groups. The concentration of plasma vitamin E was significantly increased by the naringin supplementation. When comparing the antioxidant enzyme gene expression, the mRNA expression of SOD, catalase and GSH-Px was significantly up-regulated in the naringin-supplemented group. Accordingly, these results would appear to indicate that naringin, a citrus bioflavonoid, plays an important role in regulating antioxidative capacities by increasing the SOD and catalase activities, up-regulating the gene expressions of SOD, catalase, and GSH-Px, and protecting the plasma vitamin E. In contrast, lovastatin exhibited an inhibitory effect on the plasma and hepatic lipid peroxidation and increased the hepatic catalase activity in high-cholesterol fed rabbits.
Collapse
Affiliation(s)
- S M Jeon
- Korea Institute of Bioscience and Biotechnology, KIST, Yusong, Taejon
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Kang JS, Kim DJ, Ahn B, Nam KT, Kim KS, Choi M, Jang DD. Post-initiation treatment of Indole-3-carbinol did not suppress N-methyl-N-nitrosourea induced mammary carcinogenesis in rats. Cancer Lett 2001; 169:147-54. [PMID: 11431103 DOI: 10.1016/s0304-3835(01)00551-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The consumption of cruciferous vegetables (the Family of Cruciferae) such as cabbage, broccoli and Brussels sprouts has been shown to have cancer chemopreventive effects in humans and experimental animals. Indole-3-carbinol (I3C), one component of cruciferous vegetables, has been shown to exert cancer chemopreventive influence in liver, colon, and mammary tissue when given before or concurrent with exposure to a carcinogen. However in some reports, there has been evidence that consumption of I3C after carcinogen treatment might be associated with tumor promotion in some tissues. There have been no reports, to our knowledge, of post-initiation effects of I3C in the N-methyl-N-nitrosourea (MNU)-induced mammary tumor model in rats. Our studies were performed to examine this question. Ninety-six, 4-week-old female Sprague-Dawley rats were randomly divided into five groups. The animals of groups 1, 2 and 3 received an intraperitoneal injection of MNU at the age of 50 days. The animals of groups 4 and 5 were injected with saline only at the same time. Animals of groups 1 and 2 were given diet containing 100 ppm and 300 ppm I3C from week 1 until week 25 after MNU treatment. The animals of group 4 were given basal diet containing 300 ppm I3C without MNU treatment. All animals were killed at week 25. The incidences of mammary tumors in the groups 1, 2 and 3 were 95.8% (23/24), 83.3% (20/24) and 82.4% (28/34), respectively. The average number of tumors in the tumor bearing rats of the MNU and I3C 300 ppm group (group 2; 3.85+/-0.63) was higher than that in the MNU alone group (group 3; 2.46+/-0.31). These results represented that exposure to I3C after carcinogen treatment did not suppress development of mammary tumors.
Collapse
Affiliation(s)
- J S Kang
- Department of Pathology, National Institute of Toxicology Research, Korea Food and Drug Administration, Nokbeon-dong, Eunpyung-gu, 122-704, Seoul, South Korea.
| | | | | | | | | | | | | |
Collapse
|
22
|
Matsunaga N, Arakawa NT, Goka T, Nam KT, Ohneda A, Sasaki Y, Katoh K. Effects of ruminal infusion of volatile fatty acids on plasma concentration of growth hormone and insulin in sheep. Domest Anim Endocrinol 1999; 17:17-27. [PMID: 10484127 DOI: 10.1016/s0739-7240(99)00021-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In an initial experiment we observed postprandial changes in plasma concentrations of growth hormone (GH), insulin, glucagon, and somatostatin (SRIF) in sheep. We then examined whether increasing the rumen concentration of volatile fatty acids (VFA) by infusing a VFA mixture at three rates (53.5, 107, and 214 micromol/kg/min for 4 hr) mimicked the postprandial changes in hormone secretion. Feeding significantly (P < 0.05) suppressed the plasma GH concentration for 6 hr, whereas it significantly (P < 0.05) increased plasma concentrations of insulin, glucagon, and SRIF. Plasma glucose levels tended to decrease after feeding but then gradually increased over the prefeeding level (P < 0.05). Intraruminal infusion of the VFA mixture at 107 micromol/kg/min caused similar changes in ruminal VFA concentrations to those seen after feeding. The infusion significantly (P < 0.05) suppressed GH secretion in a dose-dependent manner, whereas it caused a significant (P < 0.05) increase in insulin and glucose concentrations without changing glucagon concentrations. From these results, we conclude that the postprandial change in ruminal VFA concentration may be a physiological signal which modifies GH and insulin secretion in sheep.
Collapse
Affiliation(s)
- N Matsunaga
- Department of Animal Physiology, Faculty of Agriculture, Tohoku University, Sendai, Japan.
| | | | | | | | | | | | | |
Collapse
|
23
|
Matsunaga N, Goka T, Nam KT, Oda S, Ohneda A, Sasaki Y. Inhibition of GH releasing factor (GRF)-induced GH secretion by intraruminal infusion of volatile fatty acids (VFA) in sheep. Endocr J 1997; 44:133-40. [PMID: 9152626 DOI: 10.1507/endocrj.44.133] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A VFA mixture solution containing acetate, propionate and butyrate (the molar ratio of acetate, propionate and n-butyrate = 61.7:24.3:14.0) was infused into the rumen at various rates (53.5, 107 and 214 mumol kg-1 min-1) over 6 h to examine the effects on basal and growth hormone-releasing factor (GRF, 0.25 micrograms kg-1)-induced increase in secretion of GH, insulin, glucagon and somatostatin (SRIF) in five castrated male sheep. Intraruminal infusion of the VFA mixture into the 18-h-fasted animals at the rates of 53.5, 107 and 214 mumol kg-1 min-1 finally raised the total intraruminal VFA concentration from 91.4 to 100.2 (P > 0.05), 175.9 (P < 0.05) and 234.5 (P < 0.05) mmol l-1, respectively. A preliminary experiment showed that an infusion rate of 107 mumol kg-1 min-1 mimics the postprandial increase in ruminal VFA. The basal plasma GH concentrations (2 to 4 h after the start of VFA infusion) and the area under the profiles for GH release in response to the intravenous GRF injection, which was done 4 h after the start of VFA infusion, were significantly decreased by the VFA infusion rates of 107 and 214 mumol kg-1 min-1. Furthermore, the VFA infusion noticeably increased basal plasma concentrations of insulin, but it scarcely changed the basal levels of glucagon, SRIF and glucose. From these results we conclude that an increase in the ruminal VFA concentration, even within the physiological range, would suppress GH secretion from the ovine anterior pituitary, and that the postprandial rise in the ruminal VFA concentration may be one of the factors normally suppressing GH secretion in sheep.
Collapse
Affiliation(s)
- N Matsunaga
- Department of Animal Physiology, Faculty of Agriculture, Tohoku University, Sendai, Japan
| | | | | | | | | | | |
Collapse
|
24
|
Abstract
The effect of intravenous infusion of acetate, propionate and butyrate (0, 3, 10, 30 mumol kg-1 min-1 over 40 min) on the secretion of growth hormone (GH), insulin and glucagon in response to growth hormone-releasing factor (GRF) injection (0.25 micrograms/kg, 10 min after the onset of acid infusion) was determined in six sheep. The intravenous injection of GRF caused a marked increase in plasma GH at every dose of each acid. The GH response to GRF was unaffected by an intravenous infusion of acetate. The basal plasma levels of insulin, glucagon and glucose were unchanged by acetate infusion. The infusion of propionate markedly suppressed the GH response to GRF in a dose-dependent manner. Propionate produced increases in plasma insulin, glucagon and glucose concentrations. Butyrate infusion also caused a significant attenuation of GRF-induced GH secretion. Butyrate infusion stimulated the secretion of both insulin and glucagon and caused hyperglycemia. After cessation of the infusion of propionate or butyrate plasma GH tended to increase again. Plasma somatostatin concentrations, which were measured only for the highest dose of butyrate, were unchanged during acid infusion, but increased on discontinuing the infusion. It is concluded that propionate and butyrate suppress GH secretion, while stimulating the secretion of insulin and glucagon in sheep.
Collapse
Affiliation(s)
- N Matsunaga
- Department of Animal Physiology, Faculty of Agriculture, Tohoku University, Sandai, Japan
| | | | | | | | | | | |
Collapse
|