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Miyajima R, Manaka H, Honda T, Hashii N, Suzuki M, Komeno M, Takao K, Ishii-Watabe A, Igarashi K, Toida T, Higashi K. Intracellular polyamine depletion induces N-linked galactosylation of the monoclonal antibody produced by CHO DP-12 cells. J Biotechnol 2023; 378:1-10. [PMID: 37922995 DOI: 10.1016/j.jbiotec.2023.10.008] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/20/2023] [Accepted: 10/30/2023] [Indexed: 11/07/2023]
Abstract
The heterogeneity of the N-linked glycan profile of therapeutic monoclonal antibodies (mAbs) derived from animal cells affects therapeutic efficacy and, therefore, needs to be appropriately controlled during the manufacturing process. In this study, we examined the effects of polyamines on the N-linked glycan profiles of mAbs produced by CHO DP-12 cells. Normal cell growth of CHO DP-12 cells and their growth arrest by α-difluoromethylornithine (DFMO), an inhibitor of the polyamine biosynthetic pathway, was observed when 0.5% fetal bovine serum was added to serum-free medium, despite the presence of cadaverine and aminopropylcadaverine, instead of putrescine and spermidine in cells. Polyamine depletion by DFMO increased IgG galactosylation, accompanied by β1,4-galactosyl transferase 1 (B4GAT1) mRNA elevation. Additionally, IgG production in polyamine-depleted cells was reduced by 30% compared to that in control cells. Therefore, we examined whether polyamine depletion induces an ER stress response. The results indicated increased expression levels of chaperones for glycoprotein folding in polyamine-depleted cells, suggesting that polyamine depletion causes ER stress related to glycoprotein folding. The effect of tunicamycin, an ER stress inducer that inhibits N-glycosylation, on the expression of B4GALT1 mRNA was examined. Tunicamycin treatment increased B4GALT1 mRNA expression. These results suggest that ER stress caused by polyamine depletion induces B4GALT1 mRNA expression, resulting in increased IgG galactosylation in CHO cells. Thus, introducing polyamines, particularly SPD, to serum-free CHO culture medium for CHO cells may contribute to consistent manufacturing and quality control of antibody production.
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Affiliation(s)
- Rin Miyajima
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hitomi Manaka
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Tatsuya Honda
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Noritaka Hashii
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-9501, Japan
| | - Masato Suzuki
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Masahiro Komeno
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Koichi Takao
- Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, Sakado, Saitama 350-0295, Japan
| | - Akiko Ishii-Watabe
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-9501, Japan
| | - Kazuei Igarashi
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan; Amine Pharma Research Institute, Innovation Plaza at Chiba University, 1-8-15 Inohana, Chuo-ku, Chiba 260-0856, Japan
| | - Toshihiko Toida
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Kyohei Higashi
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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Lee YR, Ko KS, Lee HE, Lee ES, Han K, Yoo JY, Vu BN, Choi HN, Lee YN, Hong JC, Lee KO, Kim DS. CRISPR/Cas9-Mediated HY5 Gene Editing Reduces Growth Inhibition in Chinese Cabbage ( Brassica rapa) under ER Stress. Int J Mol Sci 2023; 24:13105. [PMID: 37685921 PMCID: PMC10487758 DOI: 10.3390/ijms241713105] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Various stresses can affect the quality and yield of crops, including vegetables. In this study, CRISPR/Cas9 technology was employed to examine the role of the ELONGATED HYPOCOTYL 5 (HY5) gene in influencing the growth of Chinese cabbage (Brassica rapa). Single guide RNAs (sgRNAs) were designed to target the HY5 gene, and deep-sequencing analysis confirmed the induction of mutations in the bZIP domain of the gene. To investigate the response of Chinese cabbage to endoplasmic reticulum (ER) stress, plants were treated with tunicamycin (TM). Both wild-type and hy5 mutant plants showed increased growth inhibition with increasing TM concentration. However, the hy5 mutant plants displayed less severe growth inhibition compared to the wild type. Using nitroblue tetrazolium (NBT) and 3,3'-diaminobenzidine (DAB) staining methods, we determined the amount of reactive oxygen species (ROS) produced under ER stress conditions, and found that the hy5 mutant plants generated lower levels of ROS compared to the wild type. Under ER stress conditions, the hy5 mutant plants exhibited lower expression levels of UPR- and cell death-related genes than the wild type. These results indicate that CRISPR/Cas9-mediated editing of the HY5 gene can mitigate growth inhibition in Chinese cabbage under stresses, improving the quality and yield of crops.
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Affiliation(s)
- Ye Rin Lee
- Vegetable Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Wanju-gun 55365, Republic of Korea; (Y.R.L.); (H.E.L.); (E.S.L.); (K.H.)
| | - Ki Seong Ko
- Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (K.S.K.); (J.Y.Y.); (J.C.H.)
| | - Hye Eun Lee
- Vegetable Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Wanju-gun 55365, Republic of Korea; (Y.R.L.); (H.E.L.); (E.S.L.); (K.H.)
| | - Eun Su Lee
- Vegetable Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Wanju-gun 55365, Republic of Korea; (Y.R.L.); (H.E.L.); (E.S.L.); (K.H.)
| | - Koeun Han
- Vegetable Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Wanju-gun 55365, Republic of Korea; (Y.R.L.); (H.E.L.); (E.S.L.); (K.H.)
| | - Jae Yong Yoo
- Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (K.S.K.); (J.Y.Y.); (J.C.H.)
| | - Bich Ngoc Vu
- Division of Life Science, Division of Applied Life Sciences (BK4 Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (B.N.V.); (H.N.C.); (Y.N.L.)
| | - Ha Na Choi
- Division of Life Science, Division of Applied Life Sciences (BK4 Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (B.N.V.); (H.N.C.); (Y.N.L.)
| | - Yoo Na Lee
- Division of Life Science, Division of Applied Life Sciences (BK4 Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (B.N.V.); (H.N.C.); (Y.N.L.)
| | - Jong Chan Hong
- Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (K.S.K.); (J.Y.Y.); (J.C.H.)
- Division of Life Science, Division of Applied Life Sciences (BK4 Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (B.N.V.); (H.N.C.); (Y.N.L.)
| | - Kyun Oh Lee
- Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (K.S.K.); (J.Y.Y.); (J.C.H.)
- Division of Life Science, Division of Applied Life Sciences (BK4 Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea; (B.N.V.); (H.N.C.); (Y.N.L.)
| | - Do Sun Kim
- Vegetable Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Wanju-gun 55365, Republic of Korea; (Y.R.L.); (H.E.L.); (E.S.L.); (K.H.)
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Zhang IX, Herrmann A, Leon J, Jeyarajan S, Arunagiri A, Arvan P, Gilon P, Satin LS. ER stress increases expression of intracellular calcium channel RyR1 to modify Ca 2+ homeostasis in pancreatic beta cells. J Biol Chem 2023; 299:105065. [PMID: 37468098 PMCID: PMC10448220 DOI: 10.1016/j.jbc.2023.105065] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/21/2023] Open
Abstract
Pancreatic beta cells maintain glucose homeostasis by secreting pulses of insulin in response to a rise in plasma glucose. Pulsatile insulin secretion occurs as a result of glucose-induced oscillations in beta-cell cytosolic Ca2+. The endoplasmic reticulum (ER) helps regulate beta-cell cytosolic Ca2+, and ER stress can lead to ER Ca2+ reduction, beta-cell dysfunction, and an increased risk of type 2 diabetes. However, the mechanistic effects of ER stress on individual calcium channels are not well understood. To determine the effects of tunicamycin-induced ER stress on ER inositol 1,4,5-triphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) and their involvement in subsequent Ca2+ dysregulation, we treated INS-1 832/13 cells and primary mouse islets with ER stress inducer tunicamycin (TM). We showed TM treatment increased RyR1 mRNA without affecting RyR2 mRNA and decreased both IP3R1 and IP3R3 mRNA. Furthermore, we found stress reduced ER Ca2+ levels, triggered oscillations in cytosolic Ca2+ under subthreshold glucose conditions, and increased apoptosis and that these changes were prevented by cotreatment with the RyR1 inhibitor dantrolene. In addition, we demonstrated silencing RyR1-suppressed TM-induced subthreshold cytosolic Ca2+ oscillations, but silencing RyR2 did not affect these oscillations. In contrast, inhibiting IP3Rs with xestospongin-C failed to suppress the TM-induced cytosolic Ca2+ oscillations and did not protect beta cells from TM-induced apoptosis although xestospongin-C inclusion did prevent ER Ca2+ reduction. Taken together, these results show changes in RyR1 play a critical role in ER stress-induced Ca2+ dysfunction and beta-cell apoptosis.
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Affiliation(s)
- Irina X Zhang
- Department of Pharmacology and Brehm Diabetes Research Center, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Andrea Herrmann
- Department of Pharmacology and Brehm Diabetes Research Center, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Juan Leon
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Sivakumar Jeyarajan
- Department of Pharmacology and Brehm Diabetes Research Center, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Anoop Arunagiri
- Department of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Peter Arvan
- Department of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick Gilon
- Pole of Endocrinology, Diabetes and Nutrition (EDIN), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain, Brussels, Belgium
| | - Leslie S Satin
- Department of Pharmacology and Brehm Diabetes Research Center, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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Balasubramaniam A, Tedbury PR, Mwangi SM, Liu Y, Li G, Merlin D, Gracz AD, He P, Sarafianos SG, Srinivasan S. SARS-CoV-2 Induces Epithelial-Enteric Neuronal Crosstalk Stimulating VIP Release. Biomolecules 2023; 13:207. [PMID: 36830577 PMCID: PMC9953368 DOI: 10.3390/biom13020207] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Diarrhea is present in up to 30-50% of patients with COVID-19. The mechanism of SARS-CoV-2-induced diarrhea remains unclear. We hypothesized that enterocyte-enteric neuron interactions were important in SARS-CoV-2-induced diarrhea. SARS-CoV-2 induces endoplasmic reticulum (ER) stress in enterocytes causing the release of damage associated molecular patterns (DAMPs). The DAMPs then stimulate the release of enteric neurotransmitters that disrupt gut electrolyte homeostasis. METHODS Primary mouse enteric neurons (EN) were exposed to a conditioned medium from ACE2-expressing Caco-2 colonic epithelial cells infected with SARS-CoV-2 or treated with tunicamycin (ER stress inducer). Vasoactive intestinal peptides (VIP) expression and secretion by EN were assessed by RT-PCR and ELISA, respectively. Membrane expression of NHE3 was determined by surface biotinylation. RESULTS SARS-CoV-2 infection led to increased expression of BiP/GRP78, a marker and key regulator for ER stress in Caco-2 cells. Infected cells secreted the DAMP protein, heat shock protein 70 (HSP70), into the culture media, as revealed by proteomic and Western analyses. The expression of VIP mRNA in EN was up-regulated after treatment with a conditioned medium of SARS-CoV-2-infected Caco-2 cells. CD91, a receptor for HSP70, is abundantly expressed in the cultured mouse EN. Tunicamycin, an inducer of ER stress, also induced the release of HSP70 and Xbp1s, mimicking SARS-CoV-2 infection. Co-treatment of Caco-2 with tunicamycin (apical) and VIP (basolateral) induced a synergistic decrease in membrane expression of Na+/H+ exchanger (NHE3), an important transporter that mediates intestinal Na+/fluid absorption. CONCLUSIONS Our findings demonstrate that SARS-CoV-2 enterocyte infection leads to ER stress and the release of DAMPs that up-regulates the expression and release of VIP by EN. VIP in turn inhibits fluid absorption through the downregulation of brush-border membrane expression of NHE3 in enterocytes. These data highlight the role of epithelial-enteric neuronal crosstalk in COVID-19-related diarrhea.
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Affiliation(s)
- Arun Balasubramaniam
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
- VA Medical Center Atlanta, Decatur, GA 30033, USA
| | | | - Simon M. Mwangi
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
- VA Medical Center Atlanta, Decatur, GA 30033, USA
| | - Yunshan Liu
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
- VA Medical Center Atlanta, Decatur, GA 30033, USA
| | - Ge Li
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
- VA Medical Center Atlanta, Decatur, GA 30033, USA
| | - Didier Merlin
- VA Medical Center Atlanta, Decatur, GA 30033, USA
- Institute for Biomedical Sciences, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, GA 30302, USA
| | - Adam D. Gracz
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Peijian He
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | | | - Shanthi Srinivasan
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, GA 30322, USA
- VA Medical Center Atlanta, Decatur, GA 30033, USA
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Jin W, Fan M, Zhang Y, Zhang Q, Jing C, Jiang R, Piao C, Sun L. Polydatin prevents lipotoxicity-induced dysfunction in pancreatic β-cells by inhibiting endoplasmic reticulum stress and excessive autophagy. Phytomedicine 2022; 106:154410. [PMID: 36030747 DOI: 10.1016/j.phymed.2022.154410] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/13/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Chronically elevated free fatty acid levels can adversely affect pancreatic β-cells, leading to insulin resistance and eventually type 2 diabetes mellitus (T2DM). Polydatin (PD) from Polygonum cuspidatum has been shown to regulate blood lipid content and lower cholesterol levels. However, there have been no reports on the potential therapeutic effects and actions of PD on lipotoxicity in β-cells. PURPOSE This study aimed to investigate the protective effects of PD on palmitate (PA)-treated INS-1 insulinoma cells and diabetic mice. METHODS Cells were incubated with PA and varying concentrations of PD for 24 h. Viability assays, morphological observations, flow cytometric analysis, western blotting, and reverse transcription-quantitative polymerase chain reaction were used to assess the effects of PD on PA-induced lipotoxicity. Western blotting was used to measure the endoplasmic reticulum stress (ERS) and the levels of autophagy-related factors after incubation with inducers and inhibitors of ERS and autophagy. Diabetic mice were treated with intragastric PD for 6 weeks followed by the measurement of their physiological and blood lipid indices and assessment of the results of histological and immunofluorescence analyses. RESULTS Treatment with PD after PA exposure enhanced insulin secretion and the expression of diabetes-associated genes. PD promoted β-cell function by reducing the levels of proteins associated with ERS and autophagy while also attenuating ERS triggered by tunicamycin. PD also reduced tunicamycin-induced autophagy, indicating that it regulated ERS-mediated autophagy and reduced PA-induced cellular dysfunction. In addition, treatment of db/db mice with PD substantially reduced body weight gain, alleviated dyslipidemia, improved β-cell function, and reduced insulin resistance. CONCLUSION These results suggest that PD protects β-cells from lipotoxicity-induced dysfunction and apoptosis by inhibiting ERS and preventing excessive autophagy. Our study provides a new basis for exploring the potential of PD against β-cell lipotoxicity and T2DM.
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Affiliation(s)
- Wenqi Jin
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China; College of pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Meiling Fan
- Department of Obstetrics and Gynecology, Changchun University of Chinese Medicine, Changchun, China
| | - Yuxin Zhang
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Qi Zhang
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Chenxu Jing
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Rui Jiang
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China
| | - Chunli Piao
- Shenzhen Hospital, Guangzhou University of Chinese Medicine (Futian), Shenzhen, China.
| | - Liwei Sun
- Research Center of Traditional Chinese Medicine, the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, China; Jilin Provincial Science and Technology Innovation Cross-regional Cooperation Center of Traditional Chinese Medicine Health Product Research and Development, Changchun, China.
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6
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Ellis JL, Evason KJ, Zhang C, Fourman MN, Liu J, Ninov N, Delous M, Vanhollebeke B, Fiddes I, Otis JP, Houvras Y, Farber SA, Xu X, Lin X, Stainier DYR, Yin C. A missense mutation in the proprotein convertase gene furinb causes hepatic cystogenesis during liver development in zebrafish. Hepatol Commun 2022; 6:3083-3097. [PMID: 36017776 PMCID: PMC9592797 DOI: 10.1002/hep4.2038] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/28/2022] [Accepted: 06/17/2022] [Indexed: 12/14/2022] Open
Abstract
Hepatic cysts are fluid-filled lesions in the liver that are estimated to occur in 5% of the population. They may cause hepatomegaly and abdominal pain. Progression to secondary fibrosis, cirrhosis, or cholangiocarcinoma can lead to morbidity and mortality. Previous studies of patients and rodent models have associated hepatic cyst formation with increased proliferation and fluid secretion in cholangiocytes, which are partially due to impaired primary cilia. Congenital hepatic cysts are thought to originate from faulty bile duct development, but the underlying mechanisms are not fully understood. In a forward genetic screen, we identified a zebrafish mutant that developed hepatic cysts during larval stages. The cyst formation was not due to changes in biliary cell proliferation, bile secretion, or impairment of primary cilia. Instead, time-lapse live imaging data showed that the mutant biliary cells failed to form interconnecting bile ducts because of defects in motility and protrusive activity. Accordingly, immunostaining revealed a disorganized actin and microtubule cytoskeleton in the mutant biliary cells. By whole-genome sequencing, we determined that the cystic phenotype in the mutant was caused by a missense mutation in the furinb gene, which encodes a proprotein convertase. The mutation altered Furinb localization and caused endoplasmic reticulum (ER) stress. The cystic phenotype could be suppressed by treatment with the ER stress inhibitor 4-phenylbutyric acid and exacerbated by treatment with the ER stress inducer tunicamycin. The mutant liver also exhibited increased mammalian target of rapamycin (mTOR) signaling. Treatment with mTOR inhibitors halted cyst formation at least partially through reducing ER stress. Conclusion: Our study has established a vertebrate model for studying hepatic cystogenesis and illustrated the contribution of ER stress in the disease pathogenesis.
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Affiliation(s)
- Jillian L. Ellis
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Kimberley J. Evason
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Huntsman Cancer Institute and Department of PathologyUniversity of UtahSalt Lake CityUtahUSA
| | - Changwen Zhang
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Makenzie N. Fourman
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Jiandong Liu
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- McAllister Heart InstituteDepartment of Pathology and Laboratory MedicineSchool of MedicineThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Nikolay Ninov
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Center for Regenerative Therapies TU DresdenDresdenGermany
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus of TU DresdenGerman Center for Diabetes ResearchDresdenGermany
| | - Marion Delous
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Equipe GENDEVCentre de Recherche en Neurosciences de LyonInserm U1028CNRS UMR5292Universite Lyon 1Universite St EtienneLyonFrance
| | - Benoit Vanhollebeke
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Laboratory of Neurovascular SignalingDepartment of Molecular BiologyULB Neuroscience InstituteUniversite Libre de BruxellesGosseliesBelgium
| | - Ian Fiddes
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
| | - Jessica P. Otis
- Department of EmbryologyCarnegie Institution for ScienceBaltimoreMarylandUSA
- Department of BiologyJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Molecular and Cellular Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Yariv Houvras
- Weill Cornell Medical College and New York Presbyterian HospitalNew YorkNew YorkUSA
| | - Steven A. Farber
- Department of EmbryologyCarnegie Institution for ScienceBaltimoreMarylandUSA
- Department of BiologyJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Xiaolei Xu
- Department of Biochemistry and Molecular BiologyDepartment of Cardiovascular MedicineMayo ClinicRochesterMinnesotaUSA
| | - Xueying Lin
- Department of Biochemistry and Molecular BiologyDepartment of Cardiovascular MedicineMayo ClinicRochesterMinnesotaUSA
| | - Didier Y. R. Stainier
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Department of Developmental GeneticsMax Planck Institute for Heart and Lung ResearchBad NauheimGermany
| | - Chunyue Yin
- Division of Gastroenterology, Hepatology, and NutritionCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
- Department of Biochemistry and BiophysicsProgram in Developmental and Stem Cell BiologyLiver Center and Diabetes CenterUniversity of California, San FranciscoSan FranciscoCaliforniaUSA
- Division of Developmental BiologyCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
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7
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Groeneweg S, van Geest FS, Chen Z, Farina S, van Heerebeek REA, Meima ME, Peeters RP, Heuer H, Medici M, Visser WE. Functional Characterization of the Novel and Specific Thyroid Hormone Transporter SLC17A4. Thyroid 2022; 32:326-335. [PMID: 34937426 DOI: 10.1089/thy.2021.0257] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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] [Indexed: 01/07/2023]
Abstract
Background: A recent genome-wide association study identified the SLC17A4 locus associated with circulating free thyroxine (T4) concentrations. Human SLC17A4, being widely expressed in the gastrointestinal tract, was characterized as a novel triiodothyronine (T3) and T4 transporter. However, apart from the cellular uptake of T3 and T4, transporter characteristics are currently unknown. In this study, we delineated basic transporter characteristics of this novel thyroid hormone (TH) transporter. Methods: We performed a broad range of well-established TH transport studies in COS-1 cells transiently overexpressing SLC17A4. We studied cellular TH uptake in various incubation buffers, TH efflux, and the inhibitory effects of different TH metabolites and known inhibitors of other TH transporters on SLC17A4-mediated TH transport. Finally, we determined the effect of tunicamycin, a pharmacological inhibitor of N-linked glycosylation, and targeted mutations in Asn residues on SLC17A4 function. Results: SLC17A4 induced the cellular uptake of T3 and T4 by ∼4 times, and of reverse (r)T3 by 1.5 times over control cells. The uptake of T4 by SLC17A4 was Na+ and Cl- independent, stimulated by low extracellular pH, and reduced by various iodothyronines and metabolites thereof, particularly those that contain at least three iodine moieties irrespective of the presence of modification at the alanine side chain. None of the classical TH transporter inhibitors studied attenuated SLC17A4-mediated TH transport. SLC17A4 also facilitates the efflux of T3 and T4, and to a lesser extent of 3,3'-diiodothyronine (T2). Immunoblot studies on lysates of transfected cells cultured in absence or presence of tunicamycin indicated that SLC17A4 is subject to N-linked glycosylation. Complementary mutational studies identified Asn66, Asn75, and Asn90, which are located in extracellular loop 1, as primary targets. Conclusions: Our studies show that SLC17A4 facilitates the transport of T3 and T4, and less efficiently rT3 and 3,3'-T2. Further studies should reveal the physiological role of SLC17A4 in TH regulation.
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Affiliation(s)
- Stefan Groeneweg
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ferdy S van Geest
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Zhongli Chen
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Stefania Farina
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ramona E A van Heerebeek
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marcel E Meima
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Heike Heuer
- Department of Endocrinology, Diabetes and Metabolism, University Duisburg-Essen, Essen, Germany
| | - Marco Medici
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - W Edward Visser
- Academic Center for Thyroid Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
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8
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Lima KRP, Cavalcante FLP, Paula-Marinho SDO, Pereira IMC, Lopes LDS, Nunes JVS, Coutinho ÍAC, Gomes-Filho E, Carvalho HHD. Metabolomic profiles exhibit the influence of endoplasmic reticulum stress on sorghum seedling growth over time. Plant Physiol Biochem 2022; 170:192-205. [PMID: 34902782 DOI: 10.1016/j.plaphy.2021.11.041] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 06/14/2023]
Abstract
Environmental stresses disturb the endoplasmic reticulum (ER) protein folding. However, primary metabolic responses induced by ER stress remain unclear. Thus, we investigated the morphophysiological and metabolomic changes under ER stress, induced by dithiothreitol (DTT) and tunicamycin (TM) treatments in sorghum seedlings from 24 to 96 h. The ER stress caused lipid peroxidation and increased the expression of SbBiP1, SbPDI, and SbIRE1. The development impairment was more pronounced in roots than in shoots as distinct metabolomic profiles were observed. DTT decreased root length, lateral roots, and root hair, while TM decreased mainly the root length. At 24 h, under ER stresses, the glutamic acid and o-acetyl-serine were biomarkers in the shoots. While homoserine, pyroglutamic acid, and phosphoric acid were candidates for roots. At the latest time (96 h), kestose and galactinol were key metabolites for shoots under DTT and TM, respectively. In roots, palatinose, trehalose, and alanine were common markers for DTT and TM late exposure. The accumulation of sugars such as arabinose and kestose occurred mainly in roots in the presence of DTT at a later time, which also inhibited glycolysis and the tricarboxylic acid cycle (TCA). Amino acid metabolism was induced, which also contributed TCA components decreasing, such as succinate in shoots and citrate in roots. Thus, our study may provide new insights into primary metabolism modulated by ER stress and seedling development.
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Affiliation(s)
- Karollyny Roger Pereira Lima
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP-60440-554, Fortaleza, CE, Brazil
| | | | | | - Isabelle Mary Costa Pereira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP-60440-554, Fortaleza, CE, Brazil
| | - Lineker de Sousa Lopes
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP-60440-554, Fortaleza, CE, Brazil
| | | | | | - Enéas Gomes-Filho
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP-60440-554, Fortaleza, CE, Brazil
| | - Humberto Henrique de Carvalho
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP-60440-554, Fortaleza, CE, Brazil.
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9
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Aslan M, Elpek Ö, Akkaya B, Balaban HT, Afşar E. Organ function, sphingolipid levels and inflammation in tunicamycin induced endoplasmic reticulum stress in male rats. Hum Exp Toxicol 2021; 40:259-273. [PMID: 33527851 DOI: 10.1177/0960327120949619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Disorders of the endoplasmic reticulum (ER) lead to cellular damage but can cause cell death if ER dysfunction is prolonged. We aimed to examine liver/kidney functions, neutral sphingomyelinase (N-SMase) activity, sphingolipid levels, cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2) protein expression in rats under ER stress. ER stress was induced by tunicamycin (TM) and the ER stress inhibitor taurodeoxycholic acid (TUDCA) was injected before induction of ER stress. ER stress was confirmed by increased tissue levels of GRP78. Hematological and biochemical profiles were measured by autoanalyzers while hepatic and renal injury was evaluated via microscopy and histopathological scoring. Tissue levels of C16-C24 sphingomyelins (SM), C16-C24 ceramides (CERs) and sphingosine-1-phosphate (S1P) were determined by LC-MS/MS. Tissue cPLA2 and COX-2 were measured by western blot and activity assays. Tunicamycin treatment caused kidney and liver function test abnormalities, increased hematocrit and hemoglobin levels but decreased white blood cell counts. Histopathological findings showed hepatic necroinflammation and renal tubular damage in rats treated with TM. TUDCA administration attenuated WBC abnormalities and TM- induced hepatic/renal functional impairment in ER stress, as evident by significantly restored serum ALT, AST, creatinine, and total bilirubin levels. A significant increase was observed in N-SMase activity, tissue levels of C16-C24 CERs, cPLA2 and COX-2 expression in liver and kidney tissue under ER stress. TUDCA administration decreased tissue CER levels, cPLA2 and COX-2 expression as well as prostaglandin E2 (PGE2) formation. These results signify that ER stress causes hepatic and renal toxicity as well as CER-induced PGE2 formation in liver and kidney.
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Affiliation(s)
- Mutay Aslan
- Department of Medical Biochemistry, 64032Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Özlem Elpek
- Department of Pathology, 64032Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Bahar Akkaya
- Department of Pathology, 64032Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Hazal Tuzcu Balaban
- Department of Pathology, 64032Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Ebru Afşar
- Department of Medical Biochemistry, 64032Akdeniz University Faculty of Medicine, Antalya, Turkey
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10
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Bae H, Lim W, Bazer FW, Whang KY, Song G. Mitigation of ER-stress and inflammation by chemokine (C-C motif) ligand 21 during early pregnancy. Dev Comp Immunol 2019; 94:73-84. [PMID: 30711450 DOI: 10.1016/j.dci.2019.01.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
The immune system plays an important role in pregnancy. Chemokines recruit leukocytes at the maternal-fetal interface during early pregnancy. However, the role of the chemokine, C-C motif chemokine ligand 21 (CCL21), is less known. The aim of this study was to identify the expression of CCL21 and its receptor, CCR7, in the endometrium during estrous cycle and early pregnancy, and to investigate the functional effects of CCL21 on porcine trophectoderm (pTr) and porcine uterine luminal epithelial (pLE) cells. Our results indicated that CCL21 and CCR7 are increased in the glandular (GE) and luminal epithelium (LE) of the endometrium during early pregnancy, compared to estrous pigs. Recombinant CCL21 improved pTr and pLE cell proliferation through activation of the PI3K and MAPK pathways and suppression of tunicamycin-induced endoplasmic reticulum (ER) stress or LPS-induced inflammation. Collectively, these results provide novel insights into CCL21-mediated signaling mechanisms at the maternal-fetal interface during early pregnancy.
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Affiliation(s)
- Hyocheol Bae
- Institute of Animal Molecular Biotechnology and Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Whasun Lim
- Department of Food and Nutrition, College of Science and Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Fuller W Bazer
- Center for Animal Biotechnology and Genomics and Department of Animal Science, Texas A&M University, College Station, 77843-2471, Texas, USA
| | - Kwang-Youn Whang
- Institute of Animal Molecular Biotechnology and Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
| | - Gwonhwa Song
- Institute of Animal Molecular Biotechnology and Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
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11
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Liang W, Li X, Hu L, Ding S, Kang J, Shen J, Zheng C, Li C, Ye H, Asakawa T. An in vitro validation of the therapeutic effects of Tougu Xiaotong capsule on tunicamycin-treated chondrocytes. J Ethnopharmacol 2019; 229:215-221. [PMID: 30342192 DOI: 10.1016/j.jep.2018.10.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 10/12/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tougu Xiaotong capsule (TXC) is a Chinese herbal compound that belongs to a range of Chinese herbs functioning as 'kidney invigorators and liver softeners' commonly used to treat osteoarthritis (OA) in China. AIMS OF THE STUDY The aims of the present study are to confirm the therapeutic effects of TXC in an OA cell model and to determine the mechanisms involved in such effects. MATERIALS AND METHODS A tunicamycin (Tm)-exposed OA cell model was employed, and the effects of TXC were confirmed by observing cell viability and apoptosis. The reduced cell viability and increased apoptosis caused by Tm were improved by TXC, confirming the cellular protection of TXC. We then investigated the expression of biomarkers related to the endoplasmic reticulum (ER) stress pathway, including microRNA-211 (miR-211), a regulator in the ER stress pathway. RESULTS Downregulation of X-box binding protein 1 (Xbp-1) and miR-211 expression following Tm administration was reversed by TXC. Moreover, the upregulation by Tm of the expression levels of binding immunoglobulin protein, Xbp-1, activating transcription factor 4, C/EBP-homologous protein, Caspase-9 and Caspase-3 was downregulated by TXC. These results indicated that the ER stress pathway-related mechanism may play a potential role in the therapeutic effects of TXC. CONCLUSIONS The present study provides evidence of the therapeutic effects of TXC at the cell level and describes a cellular model for establishing the mechanisms of the effects of TXC used in the treatment of OA.
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Affiliation(s)
- Wenna Liang
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Xihai Li
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, PR China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Liu Hu
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Shanshan Ding
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Jie Kang
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Jianying Shen
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Chunsong Zheng
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, PR China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Candong Li
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Hongzhi Ye
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, PR China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China
| | - Tetsuya Asakawa
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, PR China; Department of Neurosurgery, Hamamatsu University School of Medicine, Handayama, 1-20-1, Higashi-ku, Hamamatsu-city, Shizuoka 431-3192, Japan
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12
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Takahashi N, Harada M, Hirota Y, Zhao L, Azhary JMK, Yoshino O, Izumi G, Hirata T, Koga K, Wada-Hiraike O, Fujii T, Osuga Y. A Potential Role for Endoplasmic Reticulum Stress in Progesterone Deficiency in Obese Women. Endocrinology 2017; 158:84-97. [PMID: 27886513 DOI: 10.1210/en.2016-1511] [Citation(s) in RCA: 4] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/23/2016] [Indexed: 11/19/2022]
Abstract
Obesity in reproductive-aged women is associated with a shorter luteal phase and lower progesterone levels. Lipid accumulation in follicles of obese women compromises endoplasmic reticulum (ER) function, activating ER stress in granulosa cells. We hypothesized that ER stress activation in granulosa-lutein cells (GLCs) would modulate progesterone production and contribute to obesity-associated progesterone deficiency. Pretreatment with an ER stress inducer, tunicamycin or thapsigargin, inhibited human chorionic gonadotropin (hCG)-stimulated progesterone production in cultured human GLCs. Pretreatment of human GLCs with tunicamycin inhibited hCG-stimulated expression of steroidogenic acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) messenger RNAs (mRNAs) without affecting expression of cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), as determined by real-time quantitative polymerase chain reaction. Pretreatment with tunicamycin also inhibited hCG-stimulated expression of StAR protein and 3β-HSD enzyme activity in cultured human GLCs, as determined by Western blot analysis and an enzyme immunoassay, respectively, but did not affect hCG-induced intracellular 3',5'-cyclic adenosine monophosphate accumulation. Furthermore, tunicamycin attenuated hCG-induced protein kinase A and extracellular signal-regulated kinase activation, as determined by Western blot analysis. In vivo administration of tunicamycin to pregnant mare serum gonadotropin-treated immature mice prior to hCG treatment inhibited the hCG-stimulated increase in serum progesterone levels and hCG-induced expression of StAR and 3β-HSD mRNA in the ovary without affecting serum estradiol levels or the number of corpora lutea. Our findings indicate that ER stress in the follicles of obese women contributes to progesterone deficiency by inhibiting hCG-induced progesterone production in granulosa cells.
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Affiliation(s)
- Nozomi Takahashi
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Miyuki Harada
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Yasushi Hirota
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Lin Zhao
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Dalian Medical University, Liaoning, 116044, People's Republic of China; and
| | - Jerilee M K Azhary
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Osamu Yoshino
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Gentaro Izumi
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Tetsuya Hirata
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Kaori Koga
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Osamu Wada-Hiraike
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Tomoyuki Fujii
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
| | - Yutaka Osuga
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, 113-8655, Japan
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13
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Li JG, Hao Q, Liu YX, Li P, Li P, Shao XY, Tian H, Fang YQ, Yao ST. [Advanced glycated albumin induces macrophage apoptosis via activating caspase-12 pathway]. Sheng Li Xue Bao 2016; 68:733-739. [PMID: 28004067] [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] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The purpose of the present study was to investigate the effect of advanced glycated albumin (AGE-alb) on the activation of caspase-12, a key molecule in endoplasmic reticulum stress (ERS)-associated apoptotic pathway, and to elucidate the underlying molecular mechanisms of macrophage apoptosis. RAW264.7 macrophages were treated with AGE-alb (2, 4 and 6 g/L), control albumin (C-alb, 4 g/L), tunicamycin (TM, 4 mg/L), or pretreated with 4-phenylbutyric acid (PBA, 5 mmol/L) for 1 h and then treated with AGE-alb (4 g/L). After incubation for 24 h, the cell viability and apoptosis were determined by using MTT assay and TUNEL detection kit, respectively. Lactate dehydrogenase (LDH) activity in media was determined by using an assay kit. The protein levels of caspase-12 were examined by Western blot analysis. The results showed that like TM (an ERS inducer), incubation with AGE-alb led to significant decrease in viability and increase in LDH activity in media and apoptotic rate in a dose-dependent manner. In addition, AGE-alb induced activation of caspase-12 especially at the concentration of 4 and 6 g/L (P < 0.01), which was similar to TM. However, PBA (an ERS inhibitor) protected RAW264.7 macrophages from AGE-alb-induced decrease in viability and increases in LDH activity and apoptosis. Moreover, PBA also inhibited the caspase-12 activation induced by AGE-alb (P < 0.05). These results suggest that AGE-alb may induce apoptosis in RAW 264.7 macrophages, and the mechanism may be related to the activation of ERS-associated apoptotic pathway mediated by caspase-12.
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Affiliation(s)
- Jin-Guo Li
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China
| | - Qi Hao
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China
| | - Ying-Xue Liu
- College of Population and Family Planning, Taishan Medical University, Taian 271000, China
| | - Peng Li
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China
| | - Peng Li
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China
| | - Xia-Yan Shao
- College of Population and Family Planning, Taishan Medical University, Taian 271000, China
| | - Hua Tian
- Institute of Atherosclerosis, Taishan Medical University, Taian 271000, China
| | - Yong-Qi Fang
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China
| | - Shu-Tong Yao
- College of Basic Medical Sciences, Taishan Medical University, Taian 271000, China.
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14
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Shinde V, Pitale PM, Howse W, Gorbatyuk O, Gorbatyuk M. Neuronatin is a stress-responsive protein of rod photoreceptors. Neuroscience 2016; 328:1-8. [PMID: 27109921 DOI: 10.1016/j.neuroscience.2016.04.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/12/2016] [Accepted: 04/14/2016] [Indexed: 11/20/2022]
Abstract
Neuronatin (NNAT) is a small transmembrane proteolipid that is highly expressed in the embryonic developing brain and several other peripheral tissues. This study is the first to provide evidence that NNAT is detected in the adult retina of various adult rod-dominant mammals, including wild-type (WT) rodents, transgenic rodents expressing mutant S334ter, P23H, or T17M rhodopsin, non-human primates, humans, and cone-dominant tree shrews. Immunohistochemical and quantitative real time polymerase chain reaction (qRT-PCR) analyses were applied to detect NNAT. Confocal microscopy analysis revealed that NNAT immunofluorescence is restricted to the outer segments (OSs) of photoreceptors without evidence of staining in other retinal cell types across all mammalian species. Moreover, in tree shrew retinas, we found NNAT to be co-localized with rhodopsin, indicating its predominant expression in rods. The rod-derived expression of NNAT was further confirmed by qRT-PCR in isolated rod photoreceptor cells. We also used these cells to mimic cellular stress in transgenic retinas by treating them with the endoplasmic reticulum stress inducer, tunicamycin. Thus, our data revealed accumulation of NNAT around the nucleus as compared to dispersed localization of NNAT within control cells. This distribution coincided with the partial intracellular mislocalization of NNAT to the outer nuclear layer observed in transgenic retinas. In addition, stressed retinas demonstrated an increase of NNAT mRNA and protein levels. Therefore, our study demonstrated that NNAT is a novel stress-responsive protein with a potential structural and/or functional role in adult mammalian retinas.
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Affiliation(s)
- Vishal Shinde
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Priyamvada M Pitale
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Wayne Howse
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Oleg Gorbatyuk
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States
| | - Marina Gorbatyuk
- University of Alabama at Birmingham, Department of Optometry, United States; University of Alabama at Birmingham, Department of Vision Science, School of Optometry, United States.
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15
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Johnston BA, Hooks KB, McKinstry M, Snow JW. Divergent forms of endoplasmic reticulum stress trigger a robust unfolded protein response in honey bees. J Insect Physiol 2016; 86:1-10. [PMID: 26699660 DOI: 10.1016/j.jinsphys.2015.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/04/2015] [Accepted: 12/12/2015] [Indexed: 06/05/2023]
Abstract
Honey bee colonies in the United States have suffered from an increased rate of die-off in recent years, stemming from a complex set of interacting stresses that remain poorly described. While we have some understanding of the physiological stress responses in the honey bee, our molecular understanding of honey bee cellular stress responses is incomplete. Thus, we sought to identify and began functional characterization of the components of the UPR in honey bees. The IRE1-dependent splicing of the mRNA for the transcription factor Xbp1, leading to translation of an isoform with more transactivation potential, represents the most conserved of the UPR pathways. Honey bees and other Apoidea possess unique features in the Xbp1 mRNA splice site, which we reasoned could have functional consequences for the IRE1 pathway. However, we find robust induction of target genes upon UPR stimulation. In addition, the IRE1 pathway activation, as assessed by splicing of Xbp1 mRNA upon UPR, is conserved. By providing foundational knowledge about the UPR in the honey bee and the relative sensitivity of this species to divergent stresses, this work stands to improve our understanding of the mechanistic underpinnings of honey bee health and disease.
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Affiliation(s)
- Brittany A Johnston
- Biology Department, Barnard College, New York, NY 10027, USA; Biology Department, The City College of New York - CUNY, New York, NY 10031, USA
| | - Katarzyna B Hooks
- Faculty of Life Sciences, University of Manchester, Manchester, UK; U1053 INSERM, Université de Bordeaux, France
| | - Mia McKinstry
- Biology Department, Barnard College, New York, NY 10027, USA
| | - Jonathan W Snow
- Biology Department, Barnard College, New York, NY 10027, USA.
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16
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Zheng J, Peng C, Ai Y, Wang H, Xiao X, Li J. Docosahexaenoic Acid Ameliorates Fructose-Induced Hepatic Steatosis Involving ER Stress Response in Primary Mouse Hepatocytes. Nutrients 2016; 8:nu8010055. [PMID: 26805874 PMCID: PMC4728666 DOI: 10.3390/nu8010055] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [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: 12/05/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 12/11/2022] Open
Abstract
The increase in fructose consumption is considered to be a risk factor for developing nonalcoholic fatty liver disease (NAFLD). We investigated the effects of docosahexaenoic acid (DHA) on hepatic lipid metabolism in fructose-treated primary mouse hepatocytes, and the changes of Endoplasmic reticulum (ER) stress pathways in response to DHA treatment. The hepatocytes were treated with fructose, DHA, fructose plus DHA, tunicamycin (TM) or fructose plus 4-phenylbutyric acid (PBA) for 24 h. Intracellular triglyceride (TG) accumulation was assessed by Oil Red O staining. The mRNA expression levels and protein levels related to lipid metabolism and ER stress response were determined by real-time PCR and Western blot. Fructose treatment led to obvious TG accumulation in primary hepatocytes through increasing expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), two key enzymes in hepatic de novo lipogenesis. DHA ameliorates fructose-induced TG accumulation by upregulating the expression of carnitine palmitoyltransferase 1A (CPT-1α) and acyl-CoA oxidase 1 (ACOX1). DHA treatment or pretreatment with the ER stress inhibitor PBA significantly decreased TG accumulation and reduced the expression of glucose-regulated protein 78 (GRP78), total inositol-requiring kinase 1 (IRE1α) and p-IRE1α. The present results suggest that DHA protects against high fructose-induced hepatocellular lipid accumulation. The current findings also suggest that alleviating the ER stress response seems to play a role in the prevention of fructose-induced hepatic steatosis by DHA.
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Affiliation(s)
- Jinying Zheng
- School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Innovation Center for Social Risk Governance in Health, Chongqing 400016, China.
| | - Chuan Peng
- Laboratory of Lipid & Glucose Metabolism, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| | - Yanbiao Ai
- School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Innovation Center for Social Risk Governance in Health, Chongqing 400016, China.
| | - Heng Wang
- Laboratory of Lipid & Glucose Metabolism, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| | - Xiaoqiu Xiao
- Laboratory of Lipid & Glucose Metabolism, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| | - Jibin Li
- School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Innovation Center for Social Risk Governance in Health, Chongqing 400016, China.
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17
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Cho Y, Yu CY, Iwasa T, Kanehara K. Heterotrimeric G protein subunits differentially respond to endoplasmic reticulum stress in Arabidopsis. Plant Signal Behav 2015; 10:e1061162. [PMID: 26237103 PMCID: PMC4883907 DOI: 10.1080/15592324.2015.1061162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/06/2015] [Indexed: 05/23/2023]
Abstract
Canonical heterotrimeric G proteins in eukaryotes are major components that localize at plasma membrane and transmit extracellular stimuli into the cell. Genome of a seed plant Arabidopsis thaliana encodes at least one Gα (GPA1), one Gβ (AGB1), and 3 Gγ (AGG1, AGG2 and AGG3) subunits. The loss-of-function mutations of G protein subunit(s) cause multiple defects in development as well as biotic and abiotic stress responses. However, it remains elusive how these subunits differentially express these defects. Here, we report that Arabidopsis heterotrimeric G protein subunits differentially respond to the endoplasmic reticulum (ER) stress. An isolated homozygous mutant of AGB1, agb1-3, was more sensitive to the tunicamycin-induced ER stress compared to the wild type and the other loss-of-function mutants of G protein subunits. Moreover, ER stress responsive genes were highly expressed in the agb1-3 plant. Our results indicate that AGB1 positively contributes to ER stress tolerance in Arabidopsis.
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Affiliation(s)
- Yueh Cho
- Institute of Plant and Microbial Biology, Academia Sinica; Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica; Taipei, Taiwan
- Graduate Institute of Biotechnology and Department of Life Sciences; National Chung-Hsing University; Taichung, Taiwan
| | - Chao-Yuan Yu
- Institute of Plant and Microbial Biology, Academia Sinica; Taipei, Taiwan
| | | | - Kazue Kanehara
- Institute of Plant and Microbial Biology, Academia Sinica; Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica; Taipei, Taiwan
- Biotechnology Center, National Chung-Hsing University; Taichung, Taiwan
- Muroran Institute of Technology; Muroran, Japan
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Kim SJ, Kang HS, Lee JH, Park JH, Jung CH, Bae JH, Oh BC, Song DK, Baek WK, Im SS. Melatonin ameliorates ER stress-mediated hepatic steatosis through miR-23a in the liver. Biochem Biophys Res Commun 2015; 458:462-469. [PMID: 25660457 DOI: 10.1016/j.bbrc.2015.01.117] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 01/25/2015] [Indexed: 01/11/2023]
Abstract
The endoplasmic reticulum (ER) stress induces hepatic steatosis and inflammation in the liver. Although melatonin ameliorates ER stress-target genes, it remains unknown whether melatonin protects against hepatic steatosis as well as inflammation through regulation of miRNA. MicroRNAs have been identified as pivotal regulators in the field of gene regulation and their dysfunctions are a common feature in a variety of metabolic diseases. Especially, among miRNAs, miR-23a has been shown to regulate ER stress. Herein, we investigated the crucial roles of melatonin in hepatic steatosis and inflammation in vivo. Tunicamycin challenge caused increase of hepatic triglyceride and intracellular calcium levels through activation of ER stress, whereas these phenomena were partially disrupted by melatonin. We also demonstrated that expression of miR-23a stimulated with tunicamycin was rescued by melatonin treatment, resulting in reduced ER stress in primary hepatocytes. Overall, these results suggest a new function of melatonin that is involved in ameliorating ER stress-induced hepatic steatosis and inflammation by attenuating miR-23a. Melatonin may be useful as a pharmacological agent to protect against hepatic metabolic diseases due to its ability to regulate expression of miR-23a.
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Affiliation(s)
- Seung-Jae Kim
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Hye Suk Kang
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Jae-Ho Lee
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Jae-Hyung Park
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Chang Hwa Jung
- Metabolism and Nutrition Research Group, Korea Food Research Institute, Seongnam, South Korea
| | - Jae-Hoon Bae
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Byung-Chul Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon 406-840, South Korea
| | - Dae-Kyu Song
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Won-Ki Baek
- Dept of Microbiology, Keimyung University School of Medicine, Daegu 704-701, South Korea
| | - Seung-Soon Im
- Dept of Physiology, Keimyung University School of Medicine, Daegu 704-701, South Korea.
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Jin H, Mimura N, Kashio M, Koseki H, Aoe T. Late-onset of spinal neurodegeneration in knock-in mice expressing a mutant BiP. PLoS One 2014; 9:e112837. [PMID: 25405877 PMCID: PMC4236098 DOI: 10.1371/journal.pone.0112837] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 10/16/2014] [Indexed: 12/26/2022] Open
Abstract
Most human neurodegenerative diseases are sporadic, and appear later in life. While the underlying mechanisms of the progression of those diseases are still unclear, investigations into the familial forms of comparable diseases suggest that endoplasmic reticulum (ER) stress is involved in the pathogenesis. Binding immunoglobulin protein (BiP) is an ER chaperone that is central to ER function. We produced knock-in mice expressing a mutant BiP that lacked the retrieval sequence in order to evaluate the effect of a functional defect in an ER chaperone in multi-cellular organisms. Here we report that heterozygous mutant BiP mice revealed motor disabilities in aging. We found a degeneration of some motoneurons in the spinal cord accompanied by accumulations of ubiquitinated proteins. The defect in retrieval of BiP by the KDEL receptor leads to impaired activities in quality control and autophagy, suggesting that functional defects in the ER chaperones may contribute to the late onset of neurodegenerative diseases.
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Affiliation(s)
- Hisayo Jin
- Department of Anesthesiology, Chiba University Graduate School of Medicine, Chiba City, Chiba, Japan
| | - Naoya Mimura
- Department of Medicine and Clinical Oncology, Chiba University Graduate School of Medicine, Chiba City, Chiba, Japan
| | - Makiko Kashio
- Department of Anesthesiology, Chiba University Graduate School of Medicine, Chiba City, Chiba, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
| | - Tomohiko Aoe
- Department of Anesthesiology, Chiba University Graduate School of Medicine, Chiba City, Chiba, Japan
- Department of Anesthesiology, Tokyo Women's Medical University, Yachiyo Medical, Center, Yachiyo, Chiba, Japan
- * E-mail:
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Ono Y, Shimazawa M, Ishisaka M, Oyagi A, Tsuruma K, Hara H. Imipramine protects mouse hippocampus against tunicamycin-induced cell death. Eur J Pharmacol 2012; 696:83-8. [PMID: 23041155 DOI: 10.1016/j.ejphar.2012.09.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 09/11/2012] [Accepted: 09/22/2012] [Indexed: 11/22/2022]
Abstract
Endoplasmic reticulum (ER) stress is implicated in various diseases. Recently, some reports have suggested that the sigma-1 receptor may play a role in ER stress, and many antidepressants have a high affinity for the sigma-1 receptor. In the present study, we focused on imipramine, a widely used antidepressant, and investigated whether it might protect against the neuronal cell death induced by tunicamycin, an ER stress inducer. In mouse cultured hippocampal HT22 cells, imipramine inhibited cell death and caspase-3 activation induced by tunicamycin, although it did not alter the elevated expressions of 78 kDa glucose-regulated protein (GRP78) and C/EBP-homologous protein (CHOP). Interestingly, in such cells application of imipramine normalized the expression of the sigma-1 receptor, which was decreased by treatment with tunicamycin alone. Additionally, NE-100, a selective sigma-1 receptor antagonist, abolished the protective effect of imipramine against such tunicamycin-induced cell death. Imipramine inhibited the reduction of mitochondrial membrane potential induced by tunicamycin, and NE-100 blocked this modulating effect of imipramine. Furthermore, in anesthetized mice intracerebroventricular administration of tunicamycin decreased the number of neuronal cells in the hippocampus, particularly in the CA1 and dentate gyrus (DG) areas, and 7 days' imipramine treatment (10mg/kg/day; i.p.) significantly suppressed these reductions in CA1 and DG. These findings suggest that imipramine protects against ER stress-induced hippocampal neuronal cell death both in vitro and in vivo. Such protection may be partly due to the sigma-1 receptor.
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Affiliation(s)
- Yoko Ono
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
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Arrojo E Drigo R, Fonseca TL, Castillo M, Salathe M, Simovic G, Mohácsik P, Gereben B, Bianco AC. Endoplasmic reticulum stress decreases intracellular thyroid hormone activation via an eIF2a-mediated decrease in type 2 deiodinase synthesis. Mol Endocrinol 2011; 25:2065-75. [PMID: 22053000 PMCID: PMC3231828 DOI: 10.1210/me.2011-1061] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [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] [Received: 04/25/2011] [Accepted: 09/20/2011] [Indexed: 12/15/2022] Open
Abstract
Cells respond rapidly to endoplasmic reticulum (ER) stress by blocking protein translation, increasing protein folding capacity, and accelerating degradation of unfolded proteins via ubiquitination and ER-associated degradation pathways. The ER resident type 2 deiodinase (D2) is normally ubiquitinated and degraded in the proteasome, a pathway that is accelerated by enzyme catalysis of T(4) to T(3). To test whether D2 is normally processed through ER-associated degradation, ER stress was induced in cells that endogenously express D2 by exposure to thapsigargin or tunicamycin. In all cell models, D2 activity was rapidly lost, to as low as of 30% of control activity, without affecting D2 mRNA levels; loss of about 40% of D2 activity and protein was also seen in human embryonic kidney 293 cells transiently expressing D2. In primary human airway cells with ER stress resulting from cystic fibrosis, D2 activity was absent. The rapid ER stress-induced loss of D2 resulted in decreased intracellular D2-mediated T(3) production. ER stress-induced loss of D2 was prevented in the absence of T(4), by blocking the proteasome with MG-132 or by treatment with chemical chaperones. Notably, ER stress did not alter D2 activity half-life but rather decreased D2 synthesis as assessed by induction of D2 mRNA and by [(35)S]methionine labeling. Remarkably, ER-stress-induced loss in D2 activity is prevented in cells transiently expressing an inactive eukaryotic initiation factor 2, indicating that this pathway mediates the loss of D2 activity. In conclusion, D2 is selectively lost during ER stress due to an eukaryotic initiation factor 2-mediated decrease in D2 synthesis and sustained proteasomal degradation. This explains the lack of D2 activity in primary human airway cells with ER stress resulting from cystic fibrosis.
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Affiliation(s)
- Rafael Arrojo E Drigo
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine Miami, Florida 33136, USA
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Abstract
Many biological processes are regulated through the selective dephosphorylation of proteins. Protein serine-threonine phosphatases are assembled from catalytic subunits bound to diverse regulatory subunits that provide substrate specificity and subcellular localization. We describe a small molecule, guanabenz, that bound to a regulatory subunit of protein phosphatase 1, PPP1R15A/GADD34, selectively disrupting the stress-induced dephosphorylation of the α subunit of translation initiation factor 2 (eIF2α). Without affecting the related PPP1R15B-phosphatase complex and constitutive protein synthesis, guanabenz prolonged eIF2α phosphorylation in human stressed cells, adjusting the protein production rates to levels manageable by available chaperones. This favored protein folding and thereby rescued cells from protein misfolding stress. Thus, regulatory subunits of phosphatases are drug targets, a property used here to restore proteostasis in stressed cells.
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Affiliation(s)
- Pavel Tsaytler
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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Zou JF, Jiang H, Hou J. [Mechanism study on low dose tunicamycin inducing myeloma cells differentiation via unfolded protein response]. Zhonghua Xue Ye Xue Za Zhi 2010; 31:675-679. [PMID: 21223718] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To explore the molecular mechanism of myeloma cell differentiation induced by low dose tunicamycin. METHOD U266 and RPMI8226 cells were incubated with low dose tunicamycin for 72h. Surface CD49e expression was assayed by flow cytometer (FCM), light chain protein in the cell culture supernatant by ELISA, the unfolded protein response (UPR) related gene GRP78 and GRP94 by real time PCR, and XBP1u and XBP1s transcription and translation changes by real time PCR and Western blot. After XBP1u gene was interfered with small RNA, and constructed plasmid was transfected into myeloma cells to up-regulated gene XBP-1u and XBP-1s reseparately, the differentiation of myeloma cells was observed again. RESULTS Small dose tunicamycin could induce both U266 and RPMI8226 myeloma cells differentiation. Compared with the control group, cell morphology changed to mature feature, the nucleo- cytoplasm ratio decreased and nucleolus reduced or disappearance, CD49e expression increased the light chain protein concentration of cell culture supernatant was up-regulated and UPR related gene GRP78 and GRP94 were up-regulated during the differentiation. XBP-1u was up-regulated at both transcription and translation level, while XBP-1s down-regulated. After XBP1u gene expression interfered with small RNA, cell differentiation was disturbed. Cell differentiation was induced while XBP-1u gene was up-regulated by plasmid transfection. CONCLUSION Low dosage of tunicamycin could induce myeloma cell UPR and differentiation, while XBP-1u a key role during the process.
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Affiliation(s)
- Jian-Feng Zou
- Department of Hematology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China
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Yusa A, Kitajima K, Habuchi O. N-linked oligosaccharides are required to produce and stabilize the active form of chondroitin 4-sulphotransferase-1. Biochem J 2009; 388:115-21. [PMID: 15628971 PMCID: PMC1186699 DOI: 10.1042/bj20041573] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [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: 11/17/2022]
Abstract
C4ST-1 (chondroitin 4-sulphotransferase-1) transfers sulphate to position 4 of N-acetylgalactosamine in chondroitin. We showed previously that purified C4ST-1 from the culture medium of rat chondrosarcoma cells was a glycoprotein containing approx. 35% N-linked oligosaccharides. In the present paper, we investigated the functional role of the N-linked oligosaccharides attached to C4ST-1. We found that (i) treatment of recombinant C4ST-1 with peptide N-glycosidase F caused a marked decrease in activity, (ii) production of the active form of C4ST-1 by COS-7 cells transfected with cDNA of C4ST-1 was inhibited by tunicamycin, (iii) deletion of the N-glycosylation site located at the C-terminal region of C4ST-1 abolished activity, (iv) attachment of a single N-glycan at the C-terminal region supported production of the active form of C4ST-1, but the resulting recombinant enzyme was much more unstable at 37 degrees C than the control recombinant protein, and (v) truncation of C-terminal region up to the N-glycosylation site at the C-terminal region resulted in total loss of activity. These observations strongly suggest that N-linked oligosaccharides attached to C4ST-1 contribute to the production and stability of the active form of C4ST-1. In addition, the N-linked oligosaccharide at the C-terminal region appears to affect the glycosylation pattern of recombinant C4ST; a broad protein band of the wildtype protein resulting from microheterogeneity of N-linked oligosaccharides disappeared and four discrete protein bands with different numbers of N-linked oligosaccharides appeared when the N-linked oligosaccharide at the C-terminal region was deleted.
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Affiliation(s)
- Akiko Yusa
- *Department of Chemistry, Aichi University of Education, Igaya-cho, Kariya, Aichi 448-8542, Japan
- †Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Ken Kitajima
- †Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
- ‡Bioscience and Biotechnology Center, Nagoya University, Nagoya 464-8601, Japan
- §Institute for Advanced Research, Nagoya University, Nagoya 464-8601, Japan
| | - Osami Habuchi
- *Department of Chemistry, Aichi University of Education, Igaya-cho, Kariya, Aichi 448-8542, Japan
- To whom correspondence should be addressed (email )
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Park YJ, Jang YM, Kwon YH. Isoflavones prevent endoplasmic reticulum stress-mediated neuronal degeneration by inhibiting tau hyperphosphorylation in SH-SY5Y cells. J Med Food 2009; 12:528-35. [PMID: 19627200 DOI: 10.1089/jmf.2008.1069] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [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: 01/19/2023] Open
Abstract
Several studies have demonstrated a protective effect of estrogen against the risk of developing neurodegenerative diseases; however, the molecular mechanisms involved have not been fully addressed. Isoflavones have been proposed as potential alternatives to estrogen replacement therapy. Therefore, in the present study, we investigated effects of isoflavones on cell death and tau phosphorylation in SH-SY5Y human neuroblastoma cells. Cells were treated with tunicamycin (TM) to induce endoplasmic reticulum (ER) stress-mediated toxicity, which is involved in development of neurodegenerative diseases. Treatment of cells with either 17beta-estradiol or isoflavones (either genistein or daidzein) significantly protected cells against cell death. The protective effect against cell death was blocked by a specific estrogen receptor blocker, ICI 182,780, suggesting that isoflavones protect against cell death via estrogen receptor-dependent pathways. Isoflavones also suppressed ER stress as determined by decreased expressions of the immunoglobulin binding protein (BiP) mRNA, spliced X-box binding protein-1 (Xbp-1) mRNAs, and C/EBP homologous protein (CHOP). TM activated glycogen synthase kinase 3beta (GSK3beta), a kinase involved in tau phosphorylation; in contrast, isoflavones inactivated GSK3beta and decreased tau hyperphosphorylation. In conclusion, our results clearly demonstrate that isoflavones prevent ER stress-mediated neurotoxicity by inhibiting tau hyperphosphorylation in SH-SY5Y cells.
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Affiliation(s)
- Youn-Jin Park
- Department of Food and Nutrition, Seoul National University, Seoul, Republic of Korea
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Klein EM, Mascheroni L, Pompa A, Ragni L, Weimar T, Lilley KS, Dupree P, Vitale A. Plant endoplasmin supports the protein secretory pathway and has a role in proliferating tissues. Plant J 2006; 48:657-73. [PMID: 17059403 DOI: 10.1111/j.1365-313x.2006.02904.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Endoplasmin is a molecular chaperone of the heat-shock protein 90 class located in the endoplasmic reticulum and its activity is poorly characterized in plants. We assessed the ability of endoplasmin to alleviate stress via its transient overexpression in tobacco protoplasts treated with tunicamycin, an inhibitor of glycosylation and inducer of the unfolded protein response (UPR). Endoplasmin supported the secretion of a model secretory protein but was less effective than BiP, the endoplasmic reticulum member of the heat-shock protein 70 family. Consistently, immunoprecipitation experiments with in vivo radioactively labelled proteins using an antiserum prepared against Arabidopsis endoplasmin showed that a much smaller number of newly synthesized polypeptides associated with endoplasmin than with BiP. Synthesis of endoplasmin was enhanced by UPR inducers in tobacco seedlings but not protoplasts. As BiP synthesis was induced in both systems, we conclude that the UPR acts differently, at least in part, on the expression of the two chaperones. Endoplasmin was not detectable in extracts of leaves and stems of the Arabidopsis endoplasmin T-DNA insertion mutant shepherd. However, the chaperone is present, albeit at low levels, in shepherd mutant callus, mature roots and tunicamycin-treated seedlings, demonstrating that the mutation is leaky. Reduced endoplasmin in the shepherd mutant has no effect on BiP protein levels in callus or mature roots, leaves and stems, but is compensated by increased BiP in seedlings. This increase occurs in proliferating rather than expanding leaf cells, indicating an important role for endoplasmin in proliferating plant tissues.
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Affiliation(s)
- Eva M Klein
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Bassini 15, 20133 Milan, Italy
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Abstract
Mutations of parkin, a protein-ubiquitin E3 ligase, are linked to Parkinson's disease (PD). Although a variety of parkin substrates have been identified, none of these is selectively expressed in dopaminergic neurons, whose degeneration plays a critical role in PD. Here we show that parkin significantly increased dopamine uptake in the human dopaminergic neuroblastoma cell line SH-SY5Y. This effect was accompanied by increased V(max) of dopamine uptake and unchanged K(m). Consistent with this, increased binding sites for dopamine transporter (DAT) ligand were observed in SH-SY5Y cells overexpressing parkin. The results were confirmed when parkin was transfected in HEK293 cells stably expressing DAT. In these cells, parkin enhanced the ubiquitination and degradation of DAT, increased its cell surface expression, and augmented dopamine uptake. The effects of parkin were significantly abrogated by its PD-causing mutations. Because the cell surface expression of functional DAT requires its oligomerization, misfolded DAT, induced either by the protein glycosylation inhibitor tunicamycin or by its C-terminal truncation, significantly attenuated cell surface expression of native DAT and reduced dopamine uptake. Expression of parkin, but not its T240R mutant, significantly alleviated these detrimental effects of misfolded DAT. Thus, our studies suggest that parkin increases dopamine uptake by enhancing the ubiquitination and degradation of misfolded DAT, so as to prevent it from interfering with the oligomerization and cell surface expression of native DAT. This function of parkin would enhance the precision of dopaminergic transmission, increase the efficiency of dopamine utilization, and reduce dopamine toxicity on neighboring cells.
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Affiliation(s)
- Houbo Jiang
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214, USA
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28
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Belcarz A, Ginalska G, Lobarzewski J, Penel C. The novel non-glycosylated invertase from Candida utilis (the properties and the conditions of production and purification). Biochim Biophys Acta 2002; 1594:40-53. [PMID: 11825607 DOI: 10.1016/s0167-4838(01)00279-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Candida utilis yeast, which is cultivated in liquid media enriched with saccharose, synthesizes the well-known invertase of 300 kDa (EC 3.2.1.26). This enzyme is present both intracellularly in the periplasmic space and extracellularly in the culture broth. However, it was determined that the same C. utilis strain cultured in certain conditions is simultaneously capable of producing another, still unknown form of invertase with a molecular mass of 60 kDa. The presence of the latter enzymatic form was detected in cells as well as in the liquid culture medium. Both invertase forms were purified using a three-step process (ion-exchange chromatography, affinity chromatography, and preparative column electrophoresis) and named, due to their different migration ratio in polyacrylamide gel electrophoresis, F-form (Fast; 60 kDa) and S-form (Slow; 300 kDa). The F-form of invertase was found to be nonglycosylated as opposed to the well-known S-form of invertase from the same source. The physicochemical properties of the F-form of invertase (isoelectric point, substrate specificity, pH, and temperature optima) were determined and compared with those of the S-form of the enzyme.
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Affiliation(s)
- A Belcarz
- Department of Biochemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
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Villanueva S, Steward O. Glycoprotein synthesis at the synapse: fractionation of polypeptides synthesized within isolated dendritic fragments by concanavalin A affinity chromatography. Brain Res Mol Brain Res 2001; 91:137-47. [PMID: 11457501 DOI: 10.1016/s0169-328x(01)00132-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The synthesis of glycosylated proteins at postsynaptic sites was evaluated by combining metabolic labeling of isolated pinched-off dendritic fragments (synaptodendrosomes) with glycoprotein isolation by Con A affinity chromatography. Three major labeled proteins were detected (apparent molecular weights of 128, 42 and 19 kDa) along with seven minor polypeptides. Treatment of the glycoprotein fraction with N-glycosidase F led to shift in the apparent molecular weight of the bands. Also, label incorporation into glycoprotein species was blocked by tunicamycin. Thus, the three prominent polypeptides and most of the minor components of this fraction corresponded to bona fide N-glycoproteins. Incubation of synaptodendrosomes with cycloheximide also inhibited label incorporation into the isolated glycoproteins, indicating that the labeling resulted from local de novo synthesis. Subcellular fractionation revealed that the labeled glycoproteins were present in soluble and particulate fractions, mainly microsomes and synaptic membranes, and one of the species (42 kDa) appeared in the incubation medium, indicating secretion. In addition, these glycoproteins were dissimilarly distributed in several brain regions, and were expressed differentially during development, reaching their highest level of synthesis during the period of synaptogenesis. These results provide evidence for local dendritic synthesis of particular glycoprotein components of the synapse.
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Affiliation(s)
- S Villanueva
- Facultad de Medicina, Instituto de Ciencias Biomedicas, Universidad de Chile, Casilla 70005-7, 6530499, Santiago, Chile
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Hattori N, Nukada T, Oda M, Tanaka S, Ogawa T, Shiota K. Evaluation of the role of N-linked oligosaccharides in rat placental lactogen action by site-directed mutagenesis. Endocr J 1998; 45:659-74. [PMID: 10395247 DOI: 10.1507/endocrj.45.659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 11/23/2022] Open
Abstract
To evaluate the role of N-linked oligosaccharides in the molecular action of rat placental lactogen (PL), recombinant PL-Im (recPL-Im) and three recPL-Im mutants were produced in COS-7 cells. The mutants, carrying Gln substitutions of Asn at putative N-glycosylation sites, were generated via site-directed mutagenesis, i.e. two single mutants (N79Q, N128Q) and one double mutant (N79Q/N128Q). Western blot analysis revealed that wild type recPL-Im had a molecular mass of 34 kDa , which was reduced to 29 kDa by tunicamycin present during expression. N79Q and N128Q had a lower molecular mass than the wild type, and a further decrease was observed for N79Q/N128Q. PL-Im was therefore N-glycosylated at both Asn79 and Asn128. Treatment of the wild type with neuraminidase caused a reduction in molecular mass, indicating that the N-linked oligosaccharides contained N-acetylneuraminic acids. In the Nb2 cell bioassay for lactogenic hormones, recPL-Im and its mutants all had growth-promoting activity but there was a decline in the growth-stimulating potency following decreases in N-glycosylation, i.e. the order of relative potencies was the wild type>N128Q> N79Q>N79Q/N128Q, suggesting that the N-linked oligosaccharides are important in the mitogenic action of the PL-Im. Wild type and all mutants had rat PRL receptor (PRL-R)-binding activity in radioreceptor assays and stimulated JAK2 phosphorylation in Nb2 cells. Interestingly however, the binding activity to PRL-R and phosphorylation of JAK2 was similar in the wild type and mutants, and these results are not in accord with the biological activity. In conclusion, the study suggested that PL-Im has two N-linked oligosaccharides which are involved in its biological activity. The ability of PL-Im to bind PRL-R and activate JAK2 appears to be independent of the N-glycosylation.
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Affiliation(s)
- N Hattori
- Department of Veterinary Medical Sciences/Animal Resource Sciences, University of Tokyo, Japan
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Zhu A, Wang ZK, Beavis R. Structural studies of alpha-N-acetylgalactosaminidase: effect of glycosylation on the level of expression, secretion efficiency, and enzyme activity. Arch Biochem Biophys 1998; 352:1-8. [PMID: 9521804 DOI: 10.1006/abbi.1998.0575] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [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: 11/22/2022]
Abstract
alpha-N-Acetylgalactosaminidase (alphaNAGAL, EC 3.2.1.49) is an exoglycosidase specific for the hydrolysis of terminal alpha-linked N-acetylgalactosamine from oligosaccharide chains. After cloning of its cDNA, the recombinant alphaNAGAL (ralphaNAGAL) was produced in Pichia pastoris, a methylotrophic yeast strain. The enzyme was hyperglycosylated by the host cells, resulting in a protein with a molecular mass of approximately 50 kDa, which was 7 kDa larger than that of its native counterpart. When deglycosylated with endoglycosidase H under nondenaturing conditions, ralphaNAGAL remained fully active, suggesting that the glycosylation is not required for enzyme activity. Data derived from mass spectrometry indicated that all three putative N-glycosylation sites [Asn residues at positions 161 (N1), 185 (N2), and 369 (N3)] in the enzyme were glycosylated, and a high-mannose structure, which was possibly phosphorylated, was attached to the sites N1 and N2. In order to examine the effect of individual N-linked oligosaccharide chains on the expression of ralphaNAGAL in P. pastoris, we mutated each of the N-glycosylation sites, as well as all three sites in the same protein molecule, by substituting the Asn with a Gln residue. The results indicate that ralphaNAGAL mutations in any of the three glycosylation sites, N2 being the most profound, impaired the expression level, altered subcellular distribution, and decreased the efficiency of secretion. Our data suggest that the N-glycosylation of ralphaNAGAL expressed in P. pastoris may be important in protein folding and resistance to protease degradation during protein synthesis, although it is apparently not required for enzyme activity.
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Affiliation(s)
- A Zhu
- Lindsley F. Kimball Research Institute, The New York Blood Center, New York, New York 10021, USA
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Abstract
Subgroup B adenoviruses (Ad3, -7, -11, -35) contain two open reading frames (ORFs) in the early E3 transcription unit that are not present in subgroup C adenoviruses (Ad2, Ad5). The product of one of these ORFs, a 20,500-kDa (20.5K) protein, was shown previously to be expressed as two diffuse 22K and 36K bands on SDS-PAGE; the 22K appeared to be the precursor to the 36K species. As judged by its predicted sequence, 20.5K is a type I membrane glycoprotein with two potential sites for N-glycosylation and a transmembrane domain near its COOH-terminus. Here we show that when Ad3- or Ad7-infected cells were radiolabeled in the presence of tunicamycin, which prevents the addition of N-linked oligosaccharides, both the 22K and the 36K forms of 20.5K showed increased mobility in SDS-PAGE, indicating that both forms contain N-linked sugars. Both the 22K and the 36K forms were sensitive to digestion by endoglycosidase F and N-glycanase, again indicating that they both contain N-linked sugars. Only the 22K species was sensitive to endoglycosidase H, indicating that it contains high-mannose-type oligosaccharides and that the 36K species contains complex-type carbohydrates. The 36K form was sensitive to neuraminidase, indicating that its sugars contain terminal sialic acid. When digested with N-glycanase and neuraminidase, the 36K form was sensitive to O-glycanase, indicating that the 36K form has O-linked oligosaccharides. The 22K form was labeled with [3H]mannose and the 36K form was labeled with [3H]glucosamine and to a much lesser extent by [3H]mannose. Altogether these results indicate that the 20.5K protein is cotranslationally modified with N-linked high-mannose oligosaccharides, then the protein moves into the Golgi and trans-Golgi network where it acquires O-linked and complex N-linked oligosaccharides.
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Affiliation(s)
- L K Hawkins
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, Missouri 63104, USA
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Abstract
Membrane cofactor protein (MCP) has been shown to act as a cellular receptor for measles virus. In previous binding studies we demonstrated a direct interaction between the measles virus H protein and MCP. The binding was shown to be independent of the O-glycans but dependent on the N-glycans of MCP. To elucidate the role of N-glycans for the receptor function of MCP, the effect of the glycosylation inhibitors tunicamycin (TM) and 1-deoxymannojirimycin (DMJ) was analyzed. TM which prevents N-glycosylation has been reported to inhibit the expression of functional measles virus receptors. Here we show that MCP lacking all N-glycans was detectable on the surface of Vero cells, although in a reduced amount. Therefore, the lack of receptor activity cannot be explained by intracellular degradation or defective transport. In the presence of DMJ, a mannosidase I inhibitor, MCP is synthesized with N-glycans of the high-mannose type in contrast to the complex oligosaccharides present on MCP of untreated cells. Both MCP with mannose-rich and MCP with complex N-glycans were recognized by measles virus H protein in an in vitro binding assay. They both could also serve as receptors for the infection of cultured Vero cells, arguing against a direct binding of virus to a carbohydrate moiety within the N-glycans of MCP. We propose that N-linked oligosaccharides are required to maintain a conformation-dependent receptor determinant of MCP.
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Affiliation(s)
- A Maisner
- Institut für Virologie, Philipps-Universität Marburg, Germany
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Abstract
We investigated the transmembrane topology of the glutamate receptor GluR1 by introducing N-glycosylation sites as reporter sites for an extracellular location of the respective site. Our data show that the N-terminus is extracellular, whereas the C-terminus is intracellular. Most importantly, we found only three transmembrane domains (designated TMD A, TMD B, and TMD C), which correspond to the previously proposed TMDs I, III, and IV, respectively. Contrary to earlier models, the putative channel-lining hydrophobic domain TMD II does not span the membrane, but either lies in close proximity to the intracellular face of the plasma membrane or loops into the membrane without transversing it. Furthermore, the region between TMDs III and IV, in previous models believed to be intracellular, is an entirely extracellular domain.
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Affiliation(s)
- M Hollmann
- Molecular Neurobiology Laboratory, Salk Institute, La Jolla, California 92037
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Abstract
Varicella-zoster virus (VZV)-seropositive human sera were shown to be reactive with the truncated VZV gpI(gE) candidate subunit vaccine (TgpI-511). To identify the location of antibody-binding sites (epitopes) on TgpI-511, three truncated forms of TgpI-511 glycoprotein (TgpI-124, TgpI-160, TgpI-316) DNA encoding the N-terminal region of this glycoprotein with amino acid residues of 124, 160 and 360, respectively, were inserted into the vaccinia virus genome. Infection of cells with recombinant vaccinia viruses resulted in the secretion of all three truncated gpI(gE) as well as TgpI-511 from the infected cells. Immunoprecipitation of these truncated glycoproteins with VZV-seropositive human sera and gpI(gE)-specific monoclonal antibodies identified the location of four new antibody-binding sites on the VZV TgpI-511 glycoprotein. In addition, tunicamycin treatment and O-glycanase digestion revealed the presence of both N-linked and O-linked oligosaccharides on TgpI-511. These results revealed the location of new epitopes on VZV TgpI-511 and demonstrated that the epitopes on TgpI-511 were recognized by human sera from VZV-seropositive individuals.
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Affiliation(s)
- A Vafai
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford 61107-1897
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Kodama H, Asai K, Adachi T, Mori Y, Hayashi K, Hirano K, Stigbrand T. Expression of a heterodimeric (placental-intestinal) hybrid alkaline phosphatase in KB cells. Biochim Biophys Acta 1994; 1218:163-72. [PMID: 8018716 DOI: 10.1016/0167-4781(94)90006-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A hybrid heterodimeric alkaline phosphatase expressed in KB cells, consisting of placental and intestinal (fetal) subunits, was purified by use of two different immunoaffinity columns using the monoclonal antibodies 2HIMS-1 and HPMS-1. The closely related subunits were found to yield a dimeric active enzyme glycosylated as the mature heterodimeric forms. This enzyme displays intermediate properties to the placental and intestinal (fetal) isozymes with regard to heat stability, inhibition patterns with amino acids and amino acid derivatives, as well as reactivity with monoclonal antibodies specific for human alkaline phosphatase isozymes. Peptide fragments obtained from the hybrid enzyme after cyanogen bromide cleavage belong to either the placental or intestinal (meconial) isozyme as evaluated by SDS polyacrylamid gel electrophoresis, and the N-terminal amino acid sequences, corresponding to the placental and intestinal subunits, can be identified in the peptide fragments. By N-glycanase digestion or tunicamycin treatment, the molecular mass of the subunits was reduced to 62 kDa compared to 69 kDa for the native ones. The results confirm that some cell lines can synthesize hybrid alkaline phosphatases.
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Affiliation(s)
- H Kodama
- Gifu Pharmaceutical University, Japan
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37
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Klein C, Pauly PC, DaSilva AM. Biogenesis of gp80, the GPI-anchored cohesion protein in D. discoideum. Braz J Med Biol Res 1994; 27:421-6. [PMID: 8081259] [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: 01/28/2023] Open
Abstract
We have begun to assess the contributions made by co- and post-translational modifications to the physical properties of the D. discoideum protein gp80, and its sensitivity to hydrolysis by an endogenous GPI-PLC like activity. Two-dimensional gel electrophoresis indicates that the presence of various gp80 isoforms reflects the differential processing of its N-linked oligosaccharides. The presence or absence of this modification does not, however, appear to alter the sensitivity of the protein to the endogenous GPI-PIPLC activity. gp80 synthesized in cells defective in O-glycosylation is found predominantly in the medium as proteolytic products. The relationship of the O-linked modifications to the endogenous GPI-PIPLC activity is not yet clear. However, their absence does not alter the sensitivity of gp80 to exogenous GPI-PIPLC. We attempted to inhibit the GPI anchoring of gp80 using mannoseamine. Although cells displayed a reversible block in the onset of aggregation and gp80 synthesis, this did not appear to reflect changes in anchoring. The contribution is now being examined in chimeric proteins.
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Affiliation(s)
- C Klein
- E.A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, MO 63104
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38
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Braisted JE, Raymond PA. Continued search for the cellular signals that regulate regeneration of dopaminergic neurons in goldfish retina. Brain Res Dev Brain Res 1993; 76:221-32. [PMID: 8149588 DOI: 10.1016/0165-3806(93)90210-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Intraocular injections of low doses (0.7-1.4 mM estimated intraocular concentration) of 6-hydroxydopamine (6OHDA) selectively destroy dopaminergic neurons in the inner nuclear layer (INL) of goldfish retina, and they never regenerate. However, injection of a higher dose of 6OHDA (2.9 mM) destroys > 30% (but not all) of the cells in both the INL and the outer nuclear layer (ONL), but within 3 weeks, neurons in both the INL (including dopaminergic neurons) and the ONL regenerate. We hypothesize that the regenerated neurons derive from mitotic rod precursors in the ONL and that damage to the surrounding micro-environment (i.e. destruction of photoreceptors) triggers the regenerative response. To directly test this hypothesis, we selectively ablated > 99% of dopaminergic neurons (with low doses of 6OHDA) and up to 55% of rod photoreceptors (with tunicamycin), and asked whether the dopaminergic neurons regenerated, as evidenced by double immunolabeling with anti-tyrosine hydroxylase and anti-bromodeoxyuridine. After 38 days, the number of bromodeoxyuridine-immunoreactive rod nuclei was increased 2.4-fold compared to controls, but no regenerated dopaminergic neurons were found. These data suggest that although the rate of rod production increases, rod precursors do not alter their normal pathway of development to replace dopaminergic neurons in the INL when damage to the ONL is limited to destruction of rods.
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Affiliation(s)
- J E Braisted
- Department of Anatomy and Cell Biology, University of Michigan, Ann Arbor 48109-0616
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Culley D, Waldron-Edward D, Manjunath P, Mamer OA, Abikar K, Rode H, Gordon J. Clones of T cells discriminate between native and deglycosylated forms of MHC class II antigen in allostimulation. Cell Immunol 1993; 149:279-90. [PMID: 8330311 DOI: 10.1006/cimm.1993.1155] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The aim of this study was to clarify the role of the oligosaccharide side chains of MHC Class II antigens in allostimulation. The approach was to cleave the oligosaccharides from protein by subjecting plasma membranes (PM) of the Daudi cell line to chemical deglycosylation yielding deglycosylated (dgl) proteins and a supernatant fraction containing plasma membrane oligosaccharides (dgl sup). MHC Class II antigens affinity purified from the native and the dgl PM were inserted into the plasma membrane of peripheral blood leukocytes (PBL) used as stimulators in a mixed leukocyte reaction (MLR). Cells used as stimulators and as responders were from the same donor. Both native and to a lesser extent the dgl antigen could elicit a proliferative as well as a cytolytic (CML) response. A comparable reduction in the CML reaction was also obtained when native antigen was used to elicit effector cells, but the target was stripped of N-linked oligosaccharides by pretreatment with tunicamycin (TM). Five clones of responding cells raised against the native antigen were studied. Two gave proliferative reactions of equal magnitude to native and to dgl antigen alike, while three responded only to the native form. These three clones did not lyse TM-treated target cells. Inhibition experiments of CML were performed with either the dgl sup containing Daudi PM oligosaccharides or with an anti MHC-Class II MoAb. CML reactivity of the three clones which responded to native antigen was blocked by the dgl sup but not by the anti-MHC antibody. Conversely, the reaction of the two clones reactive to both forms of antigen was only inhibited by the anti-MHC antibody using intact or TM-treated targets. Accordingly, in terms of the latter set of clones oligosaccharide side chains of MHC may not be required for allostimulation. Data obtained with the set of three clones suggest that oligosaccharides could act as target of cytotoxic T cells.
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Affiliation(s)
- D Culley
- Department of Surgery, McGill University, Montreal, Quebec, Canada
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Abstract
A T-cell growth factor (TCGF) is produced by antigen- or mitogen-stimulated T lymphocytes from the South African clawed frog Xenopus laevis. This study further defines the physical and biological properties of this cytokine and demonstrates that TCGF is biochemically similar to mammalian interleukin-2 (IL-2). Biologically active TCGF eluted from SDS-PAGE displays a M(r) of 16 kD and lectin-affinity chromatography indicates that the three-dimensional configuration of carbohydrates on TCGF and human IL-2 is similar. Secretion of TCGF is detectable 1 day after stimulation of splenocytes with the T-cell mitogen phytohemagglutinin (PHA) and peaks following 2 to 3 days of stimulation. Finally, despite the biological and physical similarities between Xenopus TCGF and mammalian IL-2, anti-human IL-2 monoclonal antibodies do not recognize Xenopus TCGF.
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Affiliation(s)
- L Haynes
- Department of Microbiology and Immunology, University of Rochester Medical Center, New York 14642
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41
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Rettig WJ, Hoffman S, Su SL, Garin-Chesa P. Species diversity of neuronectin and cytotactin expression patterns in the vertebrate central nervous system. Brain Res 1992; 590:219-28. [PMID: 1384932 DOI: 10.1016/0006-8993(92)91099-z] [Citation(s) in RCA: 24] [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] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two extracellular matrix proteins of brain tissue, neuronectin (NEC1) and cytotactin (CT), are disulfide-bonded multimers of M(r) 180,000-250,000 subunits. The previously known distribution of these molecules is, however, very different. Human NEC1 is found throughout the white matter of rostral segments of the adult central nervous system (CNS) but not in rostral gray matter or in caudal CNS segments, including the cerebellum. In contrast, CT is absent or expressed at a low level in the adult chicken cerebrum but highly expressed in the cerebellum. Despite these differences in distribution, results obtained with antibodies that recognize NEC1 and CT in several vertebrate species indicate that these molecules are identical or at least closely related: (1) alpha NEC1 antibodies recognize proteins affinity-purified with CT-binding proteoglycan; (2) proteins recognized by alpha NEC1 and alpha CT antibodies in cells constitutively expressing the molecules, cells in which expression is induced by growth factors and phorbol ester and cells treated with tunicamycin (to block glycosylation) are identical in subunit composition and mobility on SDS gels; (3) the removal of NEC1 from culture supernatants by immunoprecipitation removes all molecules reactive with alpha CT antibodies and vice versa; (4) immunoblots of brain extracts with alpha NEC1 and alpha CT antibodies yield identical results. Having demonstrated the structural similarity between NEC1 and CT, we reexamined their distribution in the CNS. Surprisingly, the temporal and spatial distribution pattern of NEC1/CT varied greatly among species. Immunohistochemical and immunoblot experiments with adult human CNS tissues revealed significant levels of NEC1/CT in rostral but not caudal segments. In contrast, in cows and pigs the molecule is found throughout the CNS. Adult rat and mouse brains show regionally restricted expression of NEC1/CT in several areas of the cerebrum--distinct from those showing NEC1/CT in the human--and in the molecular layer of the cerebellum. Tests with fetal and newborn tissues revealed that CNS development in humans, cows and pigs is not accompanied by the marked decline in NEC1/CT levels or the changes in subunit composition found in the chicken CNS. The marked species diversity in temporospatial expression patterns suggests that intrinsic and/or extrinsic elements controlling the expression of NEC1/CT have diverged during vertebrate evolution.
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Affiliation(s)
- W J Rettig
- Department of Immunology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021
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42
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Abstract
Two monoclonal antibodies (MoAbs), F10.2 and F10.3, were selected for their ability to interfere in homotypic adhesion of human B cells. Precipitation studies and binding to intercellular adhesion molecule 1 (ICAM-1, CD54) cDNA transfected COS cells revealed that both MoAbs are directed against ICAM-1. The binding of MoAb F10.2 was inhibited by LB-2, a MoAb recognizing the NH2-terminal immunoglobulin-like domain of ICAM-1. This suggests that the epitope recognized by F10.2 is located on the first domain of the ICAM-1 molecule. Binding of the other MoAb, F10.3, was not inhibited by F10.2 nor by two other MoAbs mapping to the first domain of the ICAM-1 molecule. The ability of F10.3 to bind to ICAM-1 is influenced by glycosylation, suggesting that this epitope is located on one of the domains carrying possible glycosylation sites, i.e. domain 2, 3 or 4. The ICAM-1 epitopes recognized by F10.3 and LB-2 or F10.2 co-operated in homotypic adhesion of cells from the EBV cell line ML1. These results suggest that in addition to an epitope located on domain 1 of the ICAM-1 molecule, another epitope whose exposure can be regulated by glycosylation is involved in homotypic B-cell adhesion of cell line ML1.
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Affiliation(s)
- P Bloemen
- Department of Clinical Immunology, University Hospital, Utrecht, The Netherlands
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43
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Ehara A. [Electrophoretic variants of rat alpha-fetoprotein]. Hokkaido Igaku Zasshi 1991; 66:721-8. [PMID: 1720412] [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] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It has been well documented that rat AFP is separated into two discrete fractions electrophoretically and by ion exchange chromatography and it is generally accepted that the two forms of AFP, "Slow" and "Fast" variants, have different charges and molecular sizes. In this paper, the molecular basis of electrophoretic variants of rat alpha-fetoprotein (AFP) was studied. Carbohydrate-free rat AFP was electrophoretically homogeneous. Stepwise conversion of molecular sizes by deglycosylation with glycopeptidase F and the specific activities of the variants of which sugar chains were radiolabelled suggest that "Slow" and "Fast" variants have two and one sugar chains per molecule, respectively.
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Affiliation(s)
- A Ehara
- Department of Biochemistry, Hokkaido University School of Medicine, Sapporo, Japan
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44
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Abstract
The relationship between protein glycosylation and fatty acylation of glycoproteins was studied in the wild-type and asparagine-linked glycosylation-deficient mutants (alg1 and alg2) of Saccharomyces cerevisiae. At the non-permissive temperature (37 degrees C), both mutant cells exhibited increased incorporation of [3H]palmitate into five polypeptides based on SDS-PAGE. In contrast, the wild-type yeast cells contained [3H]palmitate-labeled polypeptides of higher molecular weights, which were converted to the bands seen in the mutant cells upon treatment of the cell extract with endoglycosidase H prior to SDS-PAGE. In addition, labeling of the wild-type yeast cells with [3H]palmitate in the presence of tunicamycin revealed the incorporation of [3H]palmitate into the same five bands as found in the alg1 and alg2 mutants at the non-permissive temperature without tunicamycin. These results indicate that fatty acylation of glycoproteins proceeds independently of protein N-glycosylation in yeast cells.
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Affiliation(s)
- P S Appukuttan
- Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799
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45
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Hunt RC, Riegler R, Davis AA. Changes in glycosylation alter the affinity of the human transferrin receptor for its ligand. J Biol Chem 1989; 264:9643-8. [PMID: 2722854] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
When transferrin receptors of human erythroleukemic cells were pulse-labeled with [35S]methionine and then chased in the absence of radioactive precursor, the first detectable immunoprecipitable form of the receptor had a molecular mass of 85 kDa. This form of the receptor was converted to the mature form of 93 kDa with a half-time of about 40-60 min. Both the immature (85 kDa) and mature (93 kDa) receptors associated as dimers, the native form of the receptor. The 85-kDa, as well as the 93-kDa, receptors bound to a monoclonal antibody raised against the transferrin receptor or to transferrin-Sepharose. In order to determine whether glycosylation was necessary for ligand binding, purified receptors were isolated from cells grown in the presence of tunicamycin. When K562 cells were grown in the presence of tunicamycin, an 80-kDa nonglycosylated form of the receptor was synthesized. This nonglycosylated receptor was also capable of dimer formation; however, much less of it reached the cell surface than the fully glycosylated form, although both untreated and tunicamycin-grown cells appeared to synthesize transferrin receptors at similar rates. Although the number of receptor molecules/cell was similar in control and tunicamycin-treated cells, the nonglycosylated receptors exhibited a much lower affinity for transferrin than those of untreated cells; in contrast, when receptors were purified by immunoprecipitation and digested with bacterial alkaline phosphatase, no difference was observed between the affinity of these receptors and undigested immunoprecipitated receptors. These results suggest that glycosylation is not necessary for specific binding of transferrin to its receptor, but the affinity of this binding can be influenced greatly by the presence or absence of carbohydrate residues.
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Affiliation(s)
- R C Hunt
- Department of Microbiology and Immunology, University of South Carolina Medical School, Columbia 29208
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46
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Walker MR, Lund J, Thompson KM, Jefferis R. Aglycosylation of human IgG1 and IgG3 monoclonal antibodies can eliminate recognition by human cells expressing Fc gamma RI and/or Fc gamma RII receptors. Biochem J 1989; 259:347-53. [PMID: 2524188 PMCID: PMC1138517 DOI: 10.1042/bj2590347] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.9] [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: 01/01/2023]
Abstract
Aglycosylated human IgG1 and IgG3 monoclonal anti-D (Rh) and human IgG1 and IgG3 chimaeric anti-5-iodo-4-hydroxy-3-nitrophenacetyl (anti-NIP) monoclonal antibodies produced in the presence of tunicamycin have been compared with the native glycosylated proteins with respect to recognition by human Fc gamma RI and/or Fc gamma RII receptors on U937, Daudi or K562 cells. Human red cells sensitized with glycosylated IgG3 form rosettes via Fc gamma RI with 60% of U937 cells. Inhibition of rosette formation required greater than 35-fold concentrated more aglycosylated than glycosylated human monoclonal anti-D (Rh) antibody. Unlabelled polyclonal human IgG and glycosylated monoclonal IgG1 and anti-D (Rh) antibody inhibited the binding of 125I-labelled monomeric human IgG binding by U937 Fc gamma RI at concentrations greater than 50-fold lower than the aglycosylated monoclonal IgG1 anti-D (Rh) (K50 approximately 3 x 10(-9) M and approximately 6 x 10(-7) M respectively). Similar results were obtained using glycosylated and aglycosylated monoclonal human IgG1 or IgG3 chimaeric anti-NIP antibody-sensitized red cells rosetting with Fc gamma RI-/Fc gamma RII+ Daudi and K562 cells. Rosette formation could be inhibited by the glycosylated form (at greater than 10(-6) M) but not by the aglycosylated form. Haemagglutination analysis using a panel of murine monoclonal antibodies specific for epitopes located on C gamma 2, C gamma 3 or C gamma 2/C gamma 3 interface regions did not demonstrate differences in Fc conformation between the glycosylated or aglycosylated human monoclonal antibodies. These data suggest that the Fc gamma RI and Fc gamma RII sites on human IgG are highly conformation-dependent and that the carbohydrate moiety serves to stabilize the Fc structure rather than interacting directly with Fc receptors.
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Affiliation(s)
- M R Walker
- Department of Immunology, Medical School, Edgbaston, Birmingham, U.K
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47
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Abstract
Pulse labeling of cells with [35S]methionine or [3H]glucosamine at different times after infection, followed by SDS-PAGE and Western immunoblotting analysis using rabbit anti-TCV hyperimmune serum, was used to resolve and identify TCV-induced intracellular proteins. The viral structural proteins (gp 200, gp 140/gp 66, gp 100/gp 120, p 52, and gp 24/p 20) were detected in radiolabeled cell extracts by 9 to 12 hours post-infection, as well as two possible non-structural proteins with apparent mol.wts. of 36,000 and 32,000. The predominant 52,000 nucleocapsid protein could be detected in cell lysates as soon as 6 to 8 hours after infection; it was initially resolved as a complex of 3 closely migrating species with mol.wts. ranging from 46,000 to 52,000. Pulse-chase and immunoprecipitation experiments indicated that gp 200 arose from a putative precursor with mol.wt. of 150,000 to 170,000, that underwent glycosylation. Proteolytic cleavage of gp 200, in turn, probably yielded the gp 100 and gp 120 species. The unique TCV hemagglutinin protein originated from a primary precursor with mol.wt. of 60,000, which underwent rapid dimerization by disulfide bond formation and glycosylation to yield gp 140. The peplomeric and matrix proteins were both shown to be N-glycosylated, as indicated by their sensitivity to tunicamycin (TM) and their resistance to sodium monensin (SM). In the presence of TM, proteins with mol.wts. of 90,000, 120-130,000, and 150,000 accumulated in TCV-infected cells rather than peplomeric glycoproteins, and the matrix protein E1 was only detected in its unglycosylated form. The addition of TM to the culture medium interfered with the maturation of progeny viral particles, as suggested by the absence of peplomers at the surface of the intravacuolar and extracellular virions, and the accumulation of amorphous material not found in the absence of the glycosylation inhibitor. High yields of virus replication were obtained, in the presence of SM, even at concentrations which greatly affected the cellular functions.
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Affiliation(s)
- S Dea
- Centre de Recherche en Médecine Comparée Université du Québec, Institut Armand-Frappier, Laval-des-Rapides, Canada
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48
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Davidson I, Malkinson M, Becker Y. Marek's disease virus serotype-1 antigens A and B and their unglycosylated precursors detected by Western blot analysis of infected cells. Virus Genes 1988; 2:5-18. [PMID: 2852416 DOI: 10.1007/bf00569733] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [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: 01/02/2023]
Abstract
The antigenic profile of cell cultures infected with Marek's disease virus (MDV) was determined by the immunoblotting method using convalescent immune serum obtained from chickens that survived infection with MDV strain GA5. The MDV antigen profile in infected cell lysates could be accurately determined since this method has advantages over the immunoprecipitation method used in other studies. We studied six very virulent MDV isolates and the prototype of serotype 1 MDV, the GA5 strain. Immunoblots of NaDodSO4-polyacrylamide gel electrophoresis (PAGE) performed under reducing conditions revealed a main viral antigen (B) of 120-130 kD, which was present in all cell lysates infected with MDV isolates. Analysis of infected cell proteins by NaDodSO4-PAGE performed under nonreducing conditions, revealed a 205 kD major MDV antigen, which, under reducing conditions, was identical to the 130 kD major antigen. The unglycosylated precursors of the major MDV antigens were elucidated. Two polypeptides of 43 and 45 kD were found to be the unglycosylated precursors of MDV antigen A (the glycosylated form of which appears in 4 distinct bands). The unglycosylated precursors of the MDV major antigen B were found to be three polypeptides of 80, 110, and 125 kD.
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Affiliation(s)
- I Davidson
- Kimron Veterinary Institute, Bet Dagan, Israel
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49
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Giuffré L, Isler P, Mach JP, Carrel S. A novel IFN-gamma regulated human melanoma associated antigen gp33-38 defined by monoclonal antibody Me14/D12. I. Identification and immunochemical characterization. J Immunol 1988; 141:2072-8. [PMID: 3139751] [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] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A novel melanoma-associated differentiation Ag whose surface expression can be enhanced or induced by IFN-gamma was identified by mAb Me14/D12. Testing of numerous tumor cell lines and tumor tissue sections showed that Me14/D12-defined Ag was present not only on melanoma but also on other tumor lines of neuroectodermal origin such as gliomas and neuroblastomas and on some lymphoblastic B cell lines, on monocytes and macrophages. Immunoprecipitation by mAb Me14/D12 of lysates from [35S]methionine-labeled melanoma cells analyzed by SDS-PAGE revealed two polypeptide chains of 33 and 38 KDa, both under reducing and nonreducing conditions. Cross-linking experiments indicated that the two chains were present at the cell surface as a dimeric structure. Two-dimensional gel electrophoresis showed that the two chains of 33 and 38 KDa had isoelectric points of 6.2 and 5.7, respectively. Treatment of the melanoma cells with tunicamycin, an inhibitor of N-linked glycosylation, resulted in a reduction of the Mr from 33 to 24 KDa and from 38 to 26 KDa. Peptide maps obtained after Staphylococcus aureus V8 protease digestion showed no shared peptides between the two chains. Although biochemical data indicate that Me14/D12 molecules do not correspond to any known MHC class II Ag, their dimeric structure, tissue distribution, and regulation of IFN-gamma suggest that they could represent a new member of the MHC class II family.
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Affiliation(s)
- L Giuffré
- Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland
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50
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Zhuang S. [ Tunicamycin retinal degeneration in animal experimentation]. Zhonghua Yan Ke Za Zhi 1988; 24:164-7. [PMID: 3147868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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