1
|
Wang Y, Zhang H, Ding F, Li J, Li L, Xu Z, Zhao Y. N-3 polyunsaturated fatty acids attenuate amyloid-beta-induced toxicity in AD transgenic Caenorhabditis elegans via promotion of proteasomal activity and activation of PPAR-gamma. J Nutr Biochem 2024; 127:109603. [PMID: 38373507 DOI: 10.1016/j.jnutbio.2024.109603] [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: 06/07/2023] [Revised: 01/31/2024] [Accepted: 02/15/2024] [Indexed: 02/21/2024]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disease that causes progressive cognitive decline. A major pathological characteristic of AD brain is the presence of senile plaques composed of β-amyloid (Aβ), the accumulation of which induces toxic cascades leading to synaptic dysfunction, neuronal apoptosis, and eventually cognitive decline. Dietary n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial for patients with early-stage AD; however, the mechanisms are not completely understood. In this study, we investigated the effects of n-3 PUFAs on Aβ-induced toxicity in a transgenic AD Caenorhabditis elegans (C. elegans) model. The results showed that EPA and DHA significantly inhibited Aβ-induced paralytic phenotype and decreased the production of reactive oxygen species while reducing the levels of Aβ in the AD worms. Further studies revealed that EPA and DHA might reduce the accumulation of Aβ by restoring the activity of proteasome. Moreover, treating worms with peroxisome proliferator-activated receptor (PPAR)-γ inhibitor GW9662 prevented the inhibitory effects of n-3 PUFAs on Aβ-induced paralytic phenotype and diminished the elevation of proteasomal activity by n-3 PUFAs, suggesting that PPARγ-mediated signals play important role in the protective effects of n-3 PUFAs against Aβ-induced toxicity.
Collapse
Affiliation(s)
- Yanqing Wang
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China
| | - Huanying Zhang
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China
| | - Feng Ding
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China
| | - Jianhua Li
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China
| | - Lianyu Li
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China
| | - Zhong Xu
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China.
| | - Yan Zhao
- Department of Bioengineering, Harbin Institute of Technology, Weihai 264209, Shandong, China.
| |
Collapse
|
2
|
Kulbacka J, Rembiałkowska N, Szewczyk A, Rossowska J, Drąg-Zalesińska M, Kulbacki M, Choromańska A. Nanosecond PEF Induces Oxidative Stress and Apoptosis via Proteasomal Activity Inhibition in Gastric Adenocarcinoma Cells with Drug Resistance. Int J Mol Sci 2022; 23:12943. [PMID: 36361727 PMCID: PMC9657809 DOI: 10.3390/ijms232112943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 07/30/2022] [Revised: 09/06/2022] [Accepted: 10/18/2022] [Indexed: 08/01/2023] Open
Abstract
Nanosecond (ns) pulsed electric field (PEF) is a technology in which the application of ultra-short electrical pulses can be used to disrupt the barrier function of cell plasma and internal membranes. Disruptions of the membrane integrity cause a substantial imbalance in cell homeostasis in which oxidative stress is a principal component. In the present study, nsPEF-induced oxidative stress was investigated in two gastric adenocarcinoma cell lines (EPG85-257P and EPG85-257RDB) which differ by their sensitivity to daunorubicin. Cells were exposed to 200 pulses of 10 ns duration, with the amplitude and pulse repetition frequency at 1 kHz, with electric field intensity varying from 12.5 to 50 kV/cm. The electroporation buffer contained either 1 mM or 2 mM calcium chloride. CellMask DeepRed visualized cell plasma permeabilization, Fluo-4 was used to visualize internal calcium ions content, and F-actin was labeled with AlexaFluor®488 for the cytoskeleton. The cellular viability was determined by MTT assay. An alkaline and neutral comet assay was employed to detect apoptotic and necrotic cell death. The luminescent method estimated the modifications in GSSG/GSH redox potential and the imbalance of proteasomal activity (chymotrypsin-, trypsin- and caspase-like). The reactive oxygen species (ROS) level was measured by flow cytometry using dihydroethidium (DHE) dye. Morphological visualization indicated cell shrinkage, affected cell membranes (characteristic bubbles and changed cell shape), and the reorganization of actin fibers with sites of its dense concentration; the effect was more intense with the increasing electric field strength. The most significant decrease in cell viability and GSSG/GSH redox potential was noted at the highest amplitude of 50 kV/cm, and calcium ions amplified this effect. nsPEF, particularly with calcium ions, inhibited proteasomal activities, resulting in increased protein degradation. nsPEF increased the percentage of apoptotic cells and ROS levels. The EPG85-257 RDB cell line, which is resistant to standard chemotherapy, was more sensitive to applied nsPEF protocols. The applied nsPEF method disrupted the metabolism of cancer cells and induced apoptotic cell death. The nsPEF ability to cause apoptosis, oxidative stress, and protein degradation make the nsPEF methodology a suitable alternative to current anticancer pharmacological methods.
Collapse
Affiliation(s)
- Julita Kulbacka
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland
| | - Nina Rembiałkowska
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland
| | - Anna Szewczyk
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland
- Department of Animal Developmental Biology, Faculty of Biological Sciences, University of Wroclaw, 50-335 Wroclaw, Poland
| | - Joanna Rossowska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 50-422 Wroclaw, Poland
| | - Małgorzata Drąg-Zalesińska
- Division of Histology and Embryology, Division of Human Morpholog and Embryology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | - Marek Kulbacki
- Polish-Japanese Academy of Information Technology, 02-008 Warsaw, Poland
- DIVE IN AI, 53-307 Wroclaw, Poland
| | - Anna Choromańska
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland
| |
Collapse
|
3
|
Sunjic SB, Gasparovic AC, Jaganjac M, Rechberger G, Meinitzer A, Grune T, Kohlwein SD, Mihaljevic B, Zarkovic N. Sensitivity of Osteosarcoma Cells to Concentration-Dependent Bioactivities of Lipid Peroxidation Product 4-Hydroxynonenal Depend on Their Level of Differentiation. Cells 2021; 10:cells10020269. [PMID: 33572933 PMCID: PMC7912392 DOI: 10.3390/cells10020269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 12/20/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 12/24/2022] Open
Abstract
4-Hydroxynonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological effects. Normal and malignant cells of the same origin express different sensitivity to HNE. We used human osteosarcoma cells (HOS) in different stages of differentiation in vitro, showing differences in mitosis, DNA synthesis, and alkaline phosphatase (ALP) staining. Differentiated HOS cells showed decreased proliferation (3H-thymidine incorporation), decreased viability (thiazolyl blue tetrazolium bromide-MTT), and increased apoptosis and necrosis (nuclear morphology by staining with 4′,6-diamidino-2-phenylindole-DAPI). Differentiated HOS also had less expressed c-MYC, but the same amount of c-FOS (immunocytochemistry). When exposed to HNE, differentiated HOS produced more reactive oxygen species (ROS) in comparison with undifferentiated HOS. To clarify this, we measured HNE metabolism by an HPLC method, total glutathione (GSH), oxidized GSH (ox GSH), glutathione transferase activity (GST), proteasomal activity by enzymatic methods, HNE-protein adducts by genuine ELISA and fatty acid composition by GC-MS in these cell cultures. Differentiated HOS cells had less GSH, lower HNE metabolism, increased formation of HNE-protein adducts, and lower proteasomal activity, in comparison to undifferentiated counterpart cells, while GST and oxGSH were the same. Fatty acids analyzed by GC-MS showed that there is an increase in C20:3 in differentiated HOS while the amount of C20:4 remained the same. The results showed that the cellular machinery responsible for protection against toxicity of HNE was less efficient in differentiated HOS cells. Moreover, differentiated HOS cells contained more C20:3 fatty acid, which might make them more sensitive to free radical-initiated oxidative chain reactions and more vulnerable to the effects of reactive aldehydes such as HNE. We propose that HNE might act as natural promotor of decay of malignant (osteosarcoma) cells in case of their differentiation associated with alteration of the lipid metabolism.
Collapse
Affiliation(s)
- Suzana Borovic Sunjic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Ana Cipak Gasparovic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Morana Jaganjac
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Gerald Rechberger
- Institute of Molecular Biosciences, Bio TechMed-Graz, University of Graz, 8010 Graz, Austria; (G.R.); (S.D.K.)
| | - Andreas Meinitzer
- University Clinic of Traumatology, University of Graz, 8010 Graz, Austria;
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany;
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, A-1090 Vienna, Austria
| | - Sepp D. Kohlwein
- Institute of Molecular Biosciences, Bio TechMed-Graz, University of Graz, 8010 Graz, Austria; (G.R.); (S.D.K.)
| | - Branka Mihaljevic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
| | - Neven Zarkovic
- Laboratory for Oxidative Stress (LabOS), Division of Molecular Medicine, Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia; (S.B.S.); (A.C.G.); (M.J.); (B.M.)
- Correspondence:
| |
Collapse
|
4
|
Karabowicz P, Wroński A, Ostrowska H, Waeg G, Zarkovic N, Skrzydlewska E. Reduced Proteasome Activity and Enhanced Autophagy in Blood Cells of Psoriatic Patients. Int J Mol Sci 2020; 21:E7608. [PMID: 33066703 DOI: 10.3390/ijms21207608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of cell components, including proteins. Therefore, we investigated the relationship between the intensity of oxidative stress and the expression and activity of the proteasomal system as well as autophagy, responsible for the degradation of oxidatively modified proteins in the blood cells of patients with psoriasis. Our results showed that the caspase-like, trypsin-like, and chymotrypsin-like activity of the 20S proteasome in lymphocytes, erythrocytes, and granulocytes was lower, while the expression of constitutive proteasome and immunoproteasome subunits in lymphocytes was increased cells of psoriatic patients compared to healthy subjects. Conversely, the expression of constitutive subunits in erythrocytes, and both constitutive and immunoproteasomal subunits in granulocytes were reduced. However, a significant increase in the autophagy flux (assessed using LC3BII/LC3BI ratio) independent of the AKT pathway was observed. The levels of 4-HNE, 4-HNE-protein adducts, and proteins carbonyl groups were significantly higher in the blood cells of psoriatic patients. The decreased activity of the 20S proteasome together with the increased autophagy and the significantly increased level of proteins carbonyl groups and 4-HNE-protein adducts indicate a proteostatic imbalance in the blood cells of patients with psoriasis.
Collapse
|
5
|
Cagala M, Pavlikova L, Seres M, Kadlecikova K, Breier A, Sulova Z. Development of Resistance to Endoplasmic Reticulum Stress-Inducing Agents in Mouse Leukemic L1210 Cells. Molecules 2020; 25:molecules25112517. [PMID: 32481618 PMCID: PMC7321222 DOI: 10.3390/molecules25112517] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 02/06/2023] Open
Abstract
Four new variants of L1210 cells resistant to endoplasmic reticulum (ER) stressors, tunicamycin (STun), thapsigargin (SThap), bortezomib (SBor), and MG-132 (SMG-132), were developed via an 18-month periodic cultivation in culture medium with a gradual increase in substance concentration. Multidrug resistance was generated for STun (to tunicamycin, bortezomib and MG-132), SThap (to tunicamycin, thapsigargin and MG-132), SBor (to bortezomib and MG-132), and SMG-132 (to bortezomib and MG-132). These cells were compared to the original L1210 cells and another two variants, which expressed P-gp due to induction with vincristine or transfection with the gene encoding P-gp, in terms of the following properties: sensitivity to either vincristine or the ER stressors listed above, proliferative activity, expression of resistance markers and proteins involved in the ER stress response, and proteasome activity. The resistance of the new cell variants to ER stressors was accompanied by a decreased proliferation rate and increased proteasome activity. The most consistent change in protein expression was the elevation of GRP78/BiP at the mRNA and protein levels in all resistant variants of L1210 cells. In conclusion, the mechanisms of resistance to these stressors have certain common features, but there are also specific differences.
Collapse
Affiliation(s)
- Martin Cagala
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia; (M.C.); (M.S.)
| | - Lucia Pavlikova
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia; (M.C.); (M.S.)
- Correspondence: (L.P.); (A.B.); (Z.S.); Tel.: +421-2-593-25-514 (A.B.); +421-2-32295510 (Z.S.)
| | - Mario Seres
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia; (M.C.); (M.S.)
| | - Karolina Kadlecikova
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovakia;
| | - Albert Breier
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia; (M.C.); (M.S.)
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovakia;
- Correspondence: (L.P.); (A.B.); (Z.S.); Tel.: +421-2-593-25-514 (A.B.); +421-2-32295510 (Z.S.)
| | - Zdena Sulova
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia; (M.C.); (M.S.)
- Correspondence: (L.P.); (A.B.); (Z.S.); Tel.: +421-2-593-25-514 (A.B.); +421-2-32295510 (Z.S.)
| |
Collapse
|
6
|
Bayram B, Nikolai S, Huebbe P, Ozcelik B, Grimm S, Grune T, Frank J, Rimbach G. Biomarkers of oxidative stress, antioxidant defence and inflammation are altered in the senescence-accelerated mouse prone 8. Age (Dordr) 2013; 35:1205-1217. [PMID: 22767392 PMCID: PMC3705129 DOI: 10.1007/s11357-012-9448-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [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: 12/28/2011] [Accepted: 06/20/2012] [Indexed: 06/01/2023]
Abstract
In this study we compared biomarkers of oxidative stress, stress response, antioxidant defence and inflammation between mice (n = 10 per group, female, 7 months old) with an accelerated (SAMP8) and a normal ageing phenotype (SAMR1). As compared to SAMR1 mice, SAMP8 mice exhibited higher levels of lipid peroxides and protein carbonyls as well as a lower activity of the proteasomal subunit β-5. Furthermore, heme oxygenase-1 and paraoxonase-1 (PON-1) status was lower in SAMP8 mice indicating impaired stress response. Biomarkers of inflammation such as C-reactive protein and serum amyloid P were elevated in SAMP8 mice. Interestingly, impaired stress response and increased inflammation in SAMP8 mice were associated with elevated concentrations of ascorbic acid and α-tocopherol in the liver. An age-dependent increase in hepatic vitamin E and a decline in PON-1 gene expression were also observed in aged compared to young C57BL/6 mice.
Collapse
Affiliation(s)
- Banu Bayram
- />Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Hermann Rodewald Strasse 6, 24098 Kiel, Germany
- />Department of Food Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey
| | - Sibylle Nikolai
- />Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Hermann Rodewald Strasse 6, 24098 Kiel, Germany
| | - Patricia Huebbe
- />Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Hermann Rodewald Strasse 6, 24098 Kiel, Germany
| | - Beraat Ozcelik
- />Department of Food Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey
| | - Stefanie Grimm
- />Institute of Nutrition, Department of Nutritional Toxicology, Friedrich Schiller University, Dornburger Strasse 24, 07743 Jena, Germany
| | - Tilman Grune
- />Institute of Nutrition, Department of Nutritional Toxicology, Friedrich Schiller University, Dornburger Strasse 24, 07743 Jena, Germany
| | - Jan Frank
- />Institute of Biological Chemistry and Nutrition, University of Hohenheim, Garbenstrasse 30, 70599 Stuttgart, Germany
| | - Gerald Rimbach
- />Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Hermann Rodewald Strasse 6, 24098 Kiel, Germany
| |
Collapse
|
7
|
Singla A, Moons DS, Snider NT, Wagenmaker ER, Jayasundera VB, Omary MB. Oxidative stress, Nrf2 and keratin up-regulation associate with Mallory-Denk body formation in mouse erythropoietic protoporphyria. Hepatology 2012; 56:322-31. [PMID: 22334478 PMCID: PMC3389581 DOI: 10.1002/hep.25664] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 01/27/2012] [Indexed: 01/02/2023]
Abstract
UNLABELLED Mallory-Denk bodies (MDBs) are hepatocyte inclusions commonly seen in steatohepatitis. They are induced in mice by feeding 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) for 12 weeks, which also causes porphyrin accumulation. Erythropoietic protoporphyria (EPP) is caused by mutations in ferrochelatase (fch), and a fraction of EPP patients develop liver disease that is phenocopied in Fech(m1Pas) mutant (fch/fch) mice, which have an inactivating fch mutation. fch/fch mice develop spontaneous MDBs, but the molecular factors involved in their formation and whether they relate to DDC-induced MDBs are unknown. We tested the hypothesis that fch mutation creates a molecular milieu that mimics experimental drug-induced MDBs. In 13- and 20-week-old fch/fch mice, serum alkaline phosphatase, alanine aminotransferase, and bile acids were increased. The 13-week-old fch/fch mice did not develop histologically evident MDBs but manifested biochemical alterations required for MDB formation, including increased transglutaminase-2 and keratin overexpression, with a greater keratin 8 (K8)-to-keratin 18 (K18) ratio, which are critical for drug-induced MDB formation. In 20-week-old fch/fch mice, spontaneous MDBs were readily detected histologically and biochemically. Short-term (3-week) DDC feeding markedly induced MDB formation in 20-week-old fch/fch mice. Under basal conditions, old fch/fch mice had significant alterations in mitochondrial oxidative-stress markers, including increased protein oxidation, decreased proteasomal activity, reduced adenosine triphosphate content, and Nrf2 (redox sensitive transcription factor) up-regulation. Nrf2 knockdown in HepG2 cells down-regulated K8, but not K18. CONCLUSION Fch/fch mice develop age-associated spontaneous MDBs, with a marked propensity for rapid MDB formation upon exposure to DDC, and therefore provide a genetic model for MDB formation. Inclusion formation in the fch/fch mice involves oxidative stress which, together with Nrf2-mediated increase in K8, promotes MDB formation.
Collapse
Affiliation(s)
- Amika Singla
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109-5622
| | - David S. Moons
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-5622
| | - Natasha T. Snider
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109-5622
| | - Elizabeth R. Wagenmaker
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109-5622
| | - V. Bernadene Jayasundera
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109-5622
| | - M. Bishr Omary
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109-5622,Department of Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-5622,To whom correspondence should be addressed: Bishr Omary, University of Michigan Medical School, Department of Molecular & Integrative Physiology, 7744 Medical Science Building II, 1137 Catherine St., Ann Arbor, MI 48109, Phone: 734-764-4376, Fax: 734-936-8813,
| |
Collapse
|
8
|
Zhong G, Liu L, Fan T, Fan P, Ji H. Degradation of transcription factor RFX5 during the inhibition of both constitutive and interferon gamma-inducible major histocompatibility complex class I expression in chlamydia-infected cells. J Exp Med 2000; 191:1525-34. [PMID: 10790427 PMCID: PMC2213440 DOI: 10.1084/jem.191.9.1525] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.7] [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] [Indexed: 11/25/2022] Open
Abstract
We have previously shown that the obligate intracellular pathogen chlamydia can suppress interferon (IFN)-gamma-inducible major histocompatibility complex (MHC) class II expression in infected cells by degrading upstream stimulation factor (USF)-1. We now report that chlamydia can also inhibit both constitutive and IFN-gamma-inducible MHC class I expression in the infected cells. The inhibition of MHC class I molecule expression correlates well with degradation of RFX5, an essential downstream transcription factor required for both the constitutive and IFN-gamma-inducible MHC class I expression. We further demonstrate that a lactacystin-sensitive proteasome-like activity identified in chlamydia-infected cell cytosolic fraction can degrade both USF-1 and RFX5. This proteasome-like activity is dependent on chlamydial but not host protein synthesis. Host preexisting proteasomes may not be required for the unique proteasome-like activity. These observations suggest that chlamydia-secreted factors may directly participate in the proteasome-like activity. Efforts to identify the chlamydial factors are underway. These findings provide novel information on the molecular mechanisms of chlamydial evasion of host immune recognition.
Collapse
Affiliation(s)
- G Zhong
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3E OW3, Canada.
| | | | | | | | | |
Collapse
|