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Makley LN, Johnson OT, Ghanakota P, Rauch JN, Osborn D, Wu TS, Cierpicki T, Carlson HA, Gestwicki JE. Chemical validation of a druggable site on Hsp27/HSPB1 using in silico solvent mapping and biophysical methods. Bioorg Med Chem 2021; 34:115990. [PMID: 33549906 PMCID: PMC7968374 DOI: 10.1016/j.bmc.2020.115990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 11/26/2022]
Abstract
Destabilizing mutations in small heat shock proteins (sHsps) are linked to multiple diseases; however, sHsps are conformationally dynamic, lack enzymatic function and have no endogenous chemical ligands. These factors render sHsps as classically "undruggable" targets and make it particularly challenging to identify molecules that might bind and stabilize them. To explore potential solutions, we designed a multi-pronged screening workflow involving a combination of computational and biophysical ligand-discovery platforms. Using the core domain of the sHsp family member Hsp27/HSPB1 (Hsp27c) as a target, we applied mixed solvent molecular dynamics (MixMD) to predict three possible binding sites, which we confirmed using NMR-based solvent mapping. Using this knowledge, we then used NMR spectroscopy to carry out a fragment-based drug discovery (FBDD) screen, ultimately identifying two fragments that bind to one of these sites. A medicinal chemistry effort improved the affinity of one fragment by ~50-fold (16 µM), while maintaining good ligand efficiency (~0.32 kcal/mol/non-hydrogen atom). Finally, we found that binding to this site partially restored the stability of disease-associated Hsp27 variants, in a redox-dependent manner. Together, these experiments suggest a new and unexpected binding site on Hsp27, which might be exploited to build chemical probes.
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Affiliation(s)
- Leah N Makley
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States; Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Oleta T Johnson
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States
| | - Phani Ghanakota
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Jennifer N Rauch
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States
| | - Delaney Osborn
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States
| | - Taia S Wu
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States
| | - Tomasz Cierpicki
- Department of Pathology, University of Michigan, Ann Arbor, MI, 48109, United States
| | - Heather A Carlson
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, United States.
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Batulan Z, Pulakazhi Venu VK, Li Y, Koumbadinga G, Alvarez-Olmedo DG, Shi C, O'Brien ER. Extracellular Release and Signaling by Heat Shock Protein 27: Role in Modifying Vascular Inflammation. Front Immunol 2016; 7:285. [PMID: 27507972 PMCID: PMC4960997 DOI: 10.3389/fimmu.2016.00285] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 07/14/2016] [Indexed: 12/31/2022] Open
Abstract
Heat shock protein 27 (HSP27) is traditionally viewed as an intracellular chaperone protein with anti-apoptotic properties. However, recent data indicate that a number of heat shock proteins, including HSP27, are also found in the extracellular space where they may signal via membrane receptors to alter gene transcription and cellular function. Therefore, there is increasing interest in better understanding how HSP27 is released from cells, its levels and composition in the extracellular space, and the cognate cell membrane receptors involved in effecting cell signaling. In this paper, the knowledge to date, as well as some emerging paradigms about the extracellular function of HSP27 is presented. Of particular interest is the role of HSP27 in attenuating atherogenesis by modifying lipid uptake and inflammation in the plaque. Moreover, the abundance of HSP27 in serum is an emerging new biomarker for ischemic events. Finally, HSP27 replacement therapy may represent a novel therapeutic opportunity for chronic inflammatory disorders, such as atherosclerosis.
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Affiliation(s)
- Zarah Batulan
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
| | - Vivek Krishna Pulakazhi Venu
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
| | - Yumei Li
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
| | - Geremy Koumbadinga
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
| | - Daiana Gisela Alvarez-Olmedo
- Oncology Laboratory, Institute for Experimental Medicine and Biology of Cuyo (IMBECU), CCT CONICET , Mendoza , Argentina
| | - Chunhua Shi
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
| | - Edward R O'Brien
- Vascular Biology Laboratory, Health Research Innovation Centre, Libin Cardiovascular Institute of Alberta, University of Calgary Cumming School of Medicine , Calgary, AB , Canada
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Iqbal MK, Zargar MA, Mudassar S, Lone GN, Yaseen SB, Andrabi KI. Expression Profiling and Cellular Localization of Stress Responsive Proteins in Squamous Cell Carcinoma of Human Esophagus. Cancer Invest 2016; 34:237-45. [PMID: 27351523 DOI: 10.1080/07357907.2016.1178760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND The ambiguity in relating expression dynamics of stress response proteins with human esophageal squamous cell carcinoma (ESCC) has sidelined the potential of stress proteins as therapeutic targets. This study was an attempt to unequivocally relate the stress protein dynamics with stage and propensity of ESCC. METHODS Surgically resected tumor and adjacent histologically normal tissue from 46 patients with esophageal squamous cell carcinoma were investigated in the present study. Expression of HSPs was analyzed by Western blotting and immunohistochemistry. RESULTS HSP expression was observed in all 46 cases both in adjacent normal and tumor tissues. The expression and the localization of individual HSP showed no significant correlation with depth of invasion, tumor grade, and pathological stage of the tumor. HSP 27 was the most abundant protein followed by HSP 90 and HSP 70. The HSP 27 localized exclusively in the cytoplasm of adjacent normal and tumor cells. HSP 70 showed dispersed expression with predominating nuclear localization in both normal and tumor tissue cells and HSP 90 was localized in cytoplasm of adjacent normal and in nucleus of tumor cells in majority of the cases. CONCLUSION Our data advocate lack of relationship between stress protein expression and the progression of ESCC. The data renew the prospect of anti-HSP drugs as therapeutic resources in light of the possibility that their use would continue to sensitize cancer cells towards drug induced apoptosis for tumor regression.
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Affiliation(s)
| | | | - Syed Mudassar
- b Department of Biochemistry , Sher-i-Kashmir Institute of Medical Sciences , Srinagar , India
| | - Ghulam Nabi Lone
- c Department of Cardio Vascular Thoracic Surgery , Sher-i-Kashmir Institute of Medical Sciences , Srinagar , India
| | - Syed Besina Yaseen
- d Department of Pathology , Sher-i-Kashmir Institute of Medical Sciences , Srinagar , India
| | - Khurshid Iqbal Andrabi
- e Department of Biotechnology , Science Block , University of Kashmir , Srinagar , India
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Comparative proteomics in acute myeloid leukemia. Contemp Oncol (Pozn) 2012; 16:95-103. [PMID: 23788862 PMCID: PMC3687393 DOI: 10.5114/wo.2012.28787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/25/2011] [Accepted: 02/13/2012] [Indexed: 01/22/2023] Open
Abstract
The term proteomics was used for the first time in 1995 to describe large-scale protein analyses. At the same time proteomics was distinguished as a new domain of the life sciences. The major object of proteomic studies is the proteome, i.e. the set of all proteins accumulating in a given cell, tissue or organ. During the last years several new methods and techniques have been developed to increase the fidelity and efficacy of proteomic analyses. The most widely used are two-dimensional electrophoresis (2DE) and mass spectrometry (MS). In the past decade proteomic analyses have also been successfully applied in biomedical research. They allow one to determine how various diseases affect the pattern of protein accumulation. In this paper, we attempt to summarize the results of the proteomic analyses of acute myeloid leukemia (AML) cells. They have increased our knowledge on the mechanisms underlying AML development and contributed to progress in AML diagnostics and treatment.
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Richardson RB. Promotional etiology for common childhood acute lymphoblastic leukemia: the infective lymphoid recovery hypothesis. Leuk Res 2011; 35:1425-31. [PMID: 21903265 DOI: 10.1016/j.leukres.2011.07.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Revised: 07/12/2011] [Accepted: 07/18/2011] [Indexed: 11/28/2022]
Abstract
This paper speculates on the role of infection in modifying a young child's risk of promoting precursor B-cell acute lymphoblastic leukemia (ALL). It is suggested that the heat shock instigated by infections, particularly in infancy, stimulates Th1 pro-inflammatory cytokines and an apoptosis-inhibitory environment. This infective stress also increases the number of cooperating oncogenic mutations in pre-leukemic cells, especially if the primary adaptive immune response is delayed. The glucocorticoid release that follows leads to acute thymic involution, a decline in antitumor immunity, and maturation arrest of B-lymphocytes. The infective lymphoid recovery hypothesis addresses an apparent contradiction-that a non-hygienic environment primes the adaptive immune response and is protective against childhood ALL, while multiple infections occurring later increase the risk of childhood ALL. In affluent (compared to less-affluent) societies, the characteristic ALL incidence peak in early childhood, and the shortened time to diagnosis, arise from surviving recurrent infections and the accumulated loss and recovery of lymphoid tissue. Evidence supporting the hypothesis, such as the role of lymphoid tissue reconstitution cytokines that stimulate proliferation stress on B-cell progenitors, comes from the study of children with congenital syndromes that are susceptible to leukemia.
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Affiliation(s)
- Richard B Richardson
- Radiological Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited (AECL), Chalk River Laboratories, Chalk River, ON, Canada.
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Ferns G, Shams S, Shafi S. Heat shock protein 27: its potential role in vascular disease. Int J Exp Pathol 2006; 87:253-74. [PMID: 16875491 PMCID: PMC2517372 DOI: 10.1111/j.1365-2613.2006.00484.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 03/23/2006] [Indexed: 11/30/2022] Open
Abstract
Heat shock proteins are molecular chaperones that have an ability to protect proteins from damage induced by environmental factors such as free radicals, heat, ischaemia and toxins, allowing denatured proteins to adopt their native configuration. Heat shock protein-27 (Hsp27) is a member of the small Hsp (sHsp) family of proteins, and has a molecular weight of approximately 27 KDa. In addition to its role as a chaperone, it has also been reported to have many additional functions. These include effects on the apoptotic pathway, cell movement and embryogenesis. In this review, we have focused on its possible role in vascular disease.
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Affiliation(s)
- Gordon Ferns
- Centre for Clinical Science and Measurement, School of Biomedical Science, University of Surrey, Guildford Surrey, UK.
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7
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Verrills NM. Clinical proteomics: present and future prospects. Clin Biochem Rev 2006; 27:99-116. [PMID: 17077880 PMCID: PMC1579414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Advances in proteomics technology offer great promise in the understanding and treatment of the molecular basis of disease. The past decade of proteomics research, the study of dynamic protein expression, post-translational modifications, cellular and sub-cellular protein distribution, and protein-protein interactions, has culminated in the identification of many disease-related biomarkers and potential new drug targets. While proteomics remains the tool of choice for discovery research, new innovations in proteomic technology now offer the potential for proteomic profiling to become standard practice in the clinical laboratory. Indeed, protein profiles can serve as powerful diagnostic markers, and can predict treatment outcome in many diseases, in particular cancer. A number of technical obstacles remain before routine proteomic analysis can be achieved in the clinic; however the standardisation of methodologies and dissemination of proteomic data into publicly available databases is starting to overcome these hurdles. At present the most promising application for proteomics is in the screening of specific subsets of protein biomarkers for certain diseases, rather than large scale full protein profiling. Armed with these technologies the impending era of individualised patient-tailored therapy is imminent. This review summarises the advances in proteomics that has propelled us to this exciting age of clinical proteomics, and highlights the future work that is required for this to become a reality.
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Affiliation(s)
- Nicole M Verrills
- Faculty of Health, University of Newcastle, Callaghan, NSW, Australia.
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Abstract
Understanding haematological malignancies at the protein level is important as the development of targeted treatments must be based on knowledge regarding the molecular pathogenesis of the tumour, inherited genetic variation and the mode of action of drugs. 'Proteomics' describes the analysis of the entire proteome of a cell or tissue and incorporates multiple technologies including Western blotting, two-dimensional gel electrophoresis, mass spectrometry, and ProteinChip-based technology. Although there are a limited number of studies to date in haematology those performed highlight the potential future impact of these technologies in the discovery of novel markers, proteins associated with drug resistance and the identification of tumour biomarkers which may facilitate the development of a rapid diagnostic test easily applicable in the clinical setting. Rapid large-scale analysis of the proteome in normal pathways and disease offers the opportunity of identification of potential diagnostic/prognostic markers and proteins associated with the malignant phenotype. This review discusses the current situation regarding the use of these technologies and the potential opportunities their future use may offer in the field of haematology.
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Affiliation(s)
- K S Rees-Unwin
- Academic Unit of Haematology and Oncology, University of Leeds, Leeds, UK
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Hanash SM, Madoz-Gurpide J, Misek DE. Identification of novel targets for cancer therapy using expression proteomics. Leukemia 2002; 16:478-85. [PMID: 11960325 DOI: 10.1038/sj.leu.2402412] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2001] [Accepted: 11/30/2001] [Indexed: 11/09/2022]
Abstract
Although most drugs target proteins, the proteome has remained largely untapped for the discovery of drug targets. The sequencing of the human genome has had a tremendous impact on proteomics and has provided a framework for protein identification. There is currently substantial interest in implementing proteomics platforms for drug target discovery. Although the field is still in the early stages, current proteomic tools include a variety of technologies that could be implemented for large-scale protein expression analysis of cells and tissues, leading to discovery of novel drug targets. Proteomics uniquely allows delineation of global changes in protein expression patterns resulting from transcriptional and post-transcriptional control, post-translational modifications and shifts in proteins between different cellular compartments. Some of the current technologies for proteome profiling and the application of proteomics to the analysis of leukemias by our group are reviewed.
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Affiliation(s)
- S M Hanash
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
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10
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Abstract
The identification of coding sequences in a number of species, including human in the near future, has ushered in the post-genome era. In this era, technologies are becoming available that allow the profiling of tissues and cell populations at the genomic, transcriptomic and proteomic levels. The molecular analysis of tissues at all three levels has been referred to as operomics. This review covers some basic technologies for operomics and their application to some lymphoid disorders. It is proposed that no one type of analysis is fully informative and that information that can be derived from the different compartments encompassed in operomics is complementary. Prospects for introducing such profiling technologies into the clinical laboratory will depend on their robustness, their user friendliness and the clinical relevance of the added information they provide, which cannot be captured through other technologies in use in the clinical laboratory.
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Affiliation(s)
- S M Hanash
- University of Michigan, Department of Pediatrics, Ann Arbor 48109, USA.
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11
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Abstract
Apoptosis is a genetically programmed, physiological method of cell destruction. A variety of genes are now recognised as positive or negative regulators of this process. Expression of inducible heat shock proteins (hsp) is known to correlate with increased resistance to apoptosis induced by a range of diverse cytotoxic agents and has been implicated in chemotherapeutic resistance of tumours and carcinogenesis. Intensive research on apoptosis over the past number of years has provided significant insights into the mechanisms and molecular events that occur during this process. The modulatory effects of hsps on apoptosis are well documented, however, the mechanisms of hsp-mediated protection against apoptosis remain to be fully defined, although several hypotheses have been proposed. Elucidation of these mechanisms should reveal novel targets for manipulating the sensitivity of leukaemic cells to therapy. This review aims to explain the currently understood process of apoptosis and the effects of hsps on this process. Several proposed mechanisms for hsp protection against apoptosis and the therapeutic implications of hsps in leukaemia are also discussed.
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Affiliation(s)
- E M Creagh
- Department of Biochemistry, University College Cork, Lee Maltings, Prospect Row, Ireland
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Vegh GL, Fulop V, Liu Y, Ng SW, Tuncer ZS, Genest DR, Paldi-Haris P, Foldi J, Mok SC, Berkowitz RS. Differential gene expression pattern between normal human trophoblast and choriocarcinoma cell lines: downregulation of heat shock protein-27 in choriocarcinoma in vitro and in vivo. Gynecol Oncol 1999; 75:391-6. [PMID: 10600295 DOI: 10.1006/gyno.1999.5599] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Our purpose was to identify potential differences in gene expression between normal trophoblast and choriocarcinoma cells. METHODS The Atlas human cDNA expression array hybridization technique was used to study the gene expression pattern in normal trophoblast and choriocarcinoma cell lines. Furthermore, to confirm heat shock protein-27 (Hsp-27) expression data, reverse transcriptase-PCR (RT-PCR), Western blot, and immunohistochemical analyses were used in vitro with cell lines and in vivo with paraffin sections. RESULTS The expression of nine genes was strongly different comparing a normal trophoblast cell line with choriocarcinoma cells on the Atlas membranes. Compared to normal trophoblast cells, six genes were upregulated and three were downregulated in choriocarcinoma cells. Furthermore, the downregulation of Hsp-27 in choriocarcinoma cells was confirmed both in vitro with cell lines and in vivo with paraffin sections using RT-PCR, Western blot, and immunohistochemical techniques. CONCLUSION cDNA expression array is a useful technique for identifying differentially expressed gene patterns in normal trophoblast and choriocarcinoma cells. The strong expression of Hsp-27 in placental villous trophoblast cells may play a role in trophoblast differentiation. The downregulation of Hsp-27 in choriocarcinoma may contribute to the extreme sensitivity of trophoblastic tumors to chemotherapy.
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Affiliation(s)
- G L Vegh
- Division of Gynecologic Oncology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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Soldes OS, Kuick RD, Thompson IA, Hughes SJ, Orringer MB, Iannettoni MD, Hanash SM, Beer DG. Differential expression of Hsp27 in normal oesophagus, Barrett's metaplasia and oesophageal adenocarcinomas. Br J Cancer 1999; 79:595-603. [PMID: 10027336 PMCID: PMC2362445 DOI: 10.1038/sj.bjc.6690094] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The protein expression patterns of normal, metaplastic and malignant oesophageal tissues were analysed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) to identify changes associated with Barrett's metaplasia and transformation to oesophageal adenocarcinoma. Heat-shock protein 27 (Hsp27), a small heat-shock protein which is protective against cytotoxic stresses, was abundant in normal oesophagus. However, Hsp27 expression was markedly lower in Barrett's metaplasia and oesophageal adenocarcinomas. This was confirmed by immunohistochemical analysis. Hsp27 protein was most highly expressed in the upper layers of squamous epithelium and exhibited a pattern of expression that corresponded with the degree of squamous maturation. Northern and Southern analysis demonstrated Hsp27 to be regulated at the level of mRNA transcription or abundance. Normal oesophageal tissues were examined for gender differences in Hsp27 expression. Women expressed fourfold higher levels of Hsp27 mRNA, however, this difference was not appreciable in protein expression. Hsp27 protein was inducible by heat shock in Barrett's adenocarcinoma cell lines and an immortalized oesophageal epithelial cell line (HET-1A), but not by oestradiol. These results demonstrate abundant constitutive expression of the stress-response protein Hsp27 in the normal oesophagus, and suggest that low-level expression in Barrett's metaplasia may be one factor which may influence susceptibility to oesophageal adenocarcinoma development.
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Affiliation(s)
- O S Soldes
- Department of Surgery, University of Michigan Medical Center, Ann Arbor 48109, USA
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Mizzen L. Immune responses to stress proteins: applications to infectious disease and cancer. BIOTHERAPY (DORDRECHT, NETHERLANDS) 1998; 10:173-89. [PMID: 9559972 DOI: 10.1007/bf02678295] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Heat shock proteins, or stress proteins have been identified as part of a highly conserved cellular defence mechanism mediated by multiple, distinct gene families and corresponding gene products. As intracellular chaperones, stress proteins participate in many essential biochemical pathways of protein maturation and function active during times of stress and during normal cellular homeostasis. In addition to their well-characterized role as protein chaperones, stress proteins are now realized to possess another important biological property: immunogenicity. Stress proteins are now understood to play a fundamental role in immune surveillance of infection and malignancy and this body of basic research has provided a framework for their clinical application. As key targets of both humoral and cellular immunity during infection, stress proteins have accordingly received considerable research interest as prophylactic vaccines for infectious disease applications. The unique and potent immunostimulatory properties of stress proteins have similarly been applied to the development of new approaches to cancer therapy, including both protein and gene-based modalities.
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Affiliation(s)
- L Mizzen
- StressGen Biotechnologies Corporation, Victoria, British Columbia, Canada
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Eskenazi AE, Powers J, Pinkas J, Oesterreich S, Fuqua SA, Frantz CN. Induction of heat shock protein 27 by hydroxyurea and its relationship to experimental metastasis. Clin Exp Metastasis 1998; 16:283-90. [PMID: 9568646 DOI: 10.1023/a:1006553127695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Treatment of tumor cells with hydroxyurea (HU) has been shown to increase the experimental metastatic potential of these cells. We have previously described the induction of stress proteins (antioxidants) by HU in B16 murine melanoma cells and their relationship to the metastatic process. We have now investigated the induction by HU of another set of stress proteins, the heat shock proteins, and their role in experimental metastasis. HU markedly increased the cellular content of heat shock protein (hsp) 27 but not of hsp 90, 72/73, or 60 as measured by immunoblotting. The induction of hsp27 protein was preceded by a specific increase in hsp27 mRNA. Furthermore, HU-treated cells were more thermotolerant. To investigate the functional role of hsp27, human hsp27 cDNA was constitutively overexpressed in B16 cells at levels seen in HU-treated cells. In separate experiments, we induced a global increase in hsps by heat shock. Neither the hsp27 transfectants nor the heat-shocked cells demonstrated an increase in their experimental metastatic capacity. We conclude that hsp27 protein is increased by HU by the specific induction of hsp27 mRNA in B16 melanoma cells but increased hsp27 protein is not responsible for the increase in experimental metastasis. Since high levels of hsp27 are associated with metastatic disease in breast and ovarian cancers, but not in our experimental system, the functional role of hsp27 in metastasis requires further study.
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Affiliation(s)
- A E Eskenazi
- Department of Pediatrics and the Marlene and Stuart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore 21201, USA.
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Xiao K, Liu W, Qu S, Sun H, Tang J. Study of heat shock protein HSP90 alpha, HSP70, HSP27 mRNA expression in human acute leukemia cells. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1997; 16:212-6. [PMID: 9389084 DOI: 10.1007/bf02888109] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The expression of three heat shock proteins (HSPs)-HSP90 alpha, HSP70, HSP27 in cells obtained from 22 patients with leukemia, K562 erythroleukemia cell line, and normal blood cells was observed by means of RNA dot blot analysis. The results showed that the expression of the HSP27 gene was enhanced in 4 cases of acute lymphoid leukemia (ALL), 7 cases of acute nonlymphoid leukemia (ANLL) and 2 cases of myelodysplastic syndrome (MDS) as compared with that of the normal blood cells, yet there was no significant difference in the HSP27 expression between the ALL and ANLL cells. The expression of HSP70 in all the 5 ALL and ANLL patients was much lower than that of the normal subjects, except 1 case of ALL and 1 case of MDS, in which the expression was obviously enhanced. All the cases including 11 ANLL, 5 ALL and 1 MDS had higher HSP90 alpha expression than the normal subjects. The enhanced expression of HSP90 alpha in leukemia cells may be associated with the active and indefinite proliferation of leukemia cells. Our results also suggest that the high expression of the HSP27 gene may not be confined to a specific type of acute leukemia.
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Affiliation(s)
- K Xiao
- Department of Hematology, Tongji Hospital, Tongji Medical University, Wuhan
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Eckerskorn C, Grimm R. Enhanced in situ gel digestion of electrophoretically separated proteins with automated peptide elution onto mini reversed-phase columns. Electrophoresis 1996; 17:899-906. [PMID: 8783015 DOI: 10.1002/elps.1150170511] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An improved method for the generation and automated isolation of internal peptides by in situ gel digestion of electrophoretically separated proteins is described. To enhance the sensitivity of the method, and to reduce the amount of sample handling steps, we have automated the extraction procedure of peptides after protein cleavage in a sodium dodecyl sulfate (SDS) gel matrix. The excised protein-containing polyacrylamide bands or spots are first minced to defined particles of about 30 microns. After in situ gel digestion, the gel slurry is transferred into a mini reversed-phase column-funnel assembly in the sample loading station of the Hewlett-Packard protein sequencer. Applying nitrogen pressure elutes peptides from the gel slurry onto the reversed-phase material. The mini reversed-phase column is then placed in an in-line column adapter and connected to a micropreparative high performance liquid chromatography (HPLC) column, where separation of the peptides under standard conditions is achieved. In the work described here complete digestions and excellent peptide recoveries allowed the generation of extensive internal sequence information from low picomole amounts of proteins. The method has been routinely applied in both laboratories for two years.
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Affiliation(s)
- C Eckerskorn
- Max-Planck-Institute of Biochemistry, Protein Chemistry Group, Martinsried, Germany
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Hitotsumatsu T, Iwaki T, Fukui M, Tateishi J. Distinctive immunohistochemical profiles of small heat shock proteins (heat shock protein 27 and alpha B-crystallin) in human brain tumors. Cancer 1996; 77:352-61. [PMID: 8625245 DOI: 10.1002/(sici)1097-0142(19960115)77:2<352::aid-cncr19>3.0.co;2-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Recent studies have described alpha B-crystallin as a member of the small heat shock protein (HSP) family, and the expressions of alpha-crystallin-related small heat shock proteins, namely HSP27 and alpha B-crystallin, in the brain appear to be regulated in a similar way by various stress conditions. METHODS A comparative immunohistochemical analysis was performed on 198 human brain tumors to examine the expressions of HSP27 and alpha B-crystallin. RESULTS Positive staining with HSP27 was frequently observed in schwannomas, craniopharyngiomas, epidermoid cysts, and metastatic tumors to the brain. The immunopositivity of HSP27 was relatively low in tumors originating from neuroepithelium as well as in meningiomas; however, a statistically significantly higher percentage of HSP27-positive cells was noted in their anaplastic counterparts, such as glioblastomas, anaplastic oligodendrogliomas, anaplastic ependymomas, and anaplastic meningiomas (P < 0.005). Conversely, a positive immunoexpression of alpha B-crystallin was frequently observed among astrocytic tumors, schwannomas, hemangioblastomas, and chordomas. CONCLUSIONS The immunohistochemical expression of HSP27 and alpha B-crystallin differed among histologic types of tumors. Furthermore, the immunopositivity of HSP27, which was considered to play a role not only in drug resistance but also in the regulation of cell proliferation, increased in proportion to the anaplasia of the tumors.
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Affiliation(s)
- T Hitotsumatsu
- Department of Neuropathology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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19
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Abstract
Recent research suggests that cells respond to electromagnetic fields in the same ways as they do to other environmental stresses.
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20
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Minowada G, Welch W. Variation in the expression and/or phosphorylation of the human low molecular weight stress protein during in vitro cell differentiation. J Biol Chem 1995; 270:7047-54. [PMID: 7706242 DOI: 10.1074/jbc.270.13.7047] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Members of the low molecular weight heat shock protein (hsp) family show regulated expression in both Drosophila and mice during development and differentiation. Here we have examined whether similar regulation of the single low molecular weight hsp (hsp 28) of humans exhibits differences in either its expression and/or phosphorylation during the course of in vitro differentiation of hematopoietic cells. In the promyelocytic leukemic cell line, HL-60, we show that early after commitment of the cells to a macrophage-like phenotype (via exposure to phorbol ester myristate, PMA) there occurs an accompanying increased phosphorylation of hsp 28. Over time and as the cells become terminally differentiated the levels of hsp 28 increase significantly. In contrast, cells stimulated to adopt a granulocyte-like phenotype (e.g. exposed to either dimethyl sulfoxide or retinoic acid) show no changes in either the phosphorylation or expression of hsp 28. Moreover, once differentiated the granulocyte-like cells no longer appear capable of phosphorylating hsp 28. Human K562 cells, in response to hemin, rapidly increase their expression and phosphorylation of hsp 28 during the course of their differentiation into erythroid-like cells. Addition of PMA to the K562 cells induces differentiation into a megakaryocyte-like phenotype but is not accompanied by changes in hsp 28 phosphorylation/expression. In the case of the HL-60 cells, differentiation toward the macrophage like lineage is accompanied by an increased adherence of the cells to their substratum and an apparent association of hsp 28 with the actin cytoskeleton.
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Affiliation(s)
- G Minowada
- Department of Medicine, University of California, San Francisco 94143, USA
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21
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Kato S, Hirano A, Kato M, Herz F, Ohama E. Comparative study on the expression of stress-response protein (srp) 72, srp 27, alpha B-crystallin and ubiquitin in brain tumours. An immunohistochemical investigation. Neuropathol Appl Neurobiol 1993; 19:436-42. [PMID: 8278027 DOI: 10.1111/j.1365-2990.1993.tb00466.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This immunohistochemical study compares the expression of stress-response (heat-shock) protein (srp) 72, srp 27, alpha B-crystallin and ubiquitin in 86 primary human brain tumours and 21 carcinoma metastases to the central nervous system. Normal brain tissues were included for control purposes. Serial sections of formalin-fixed, paraffin-embedded tissues were used. Most meningiomas (17/23), glioblastomas (11/12) and breast carcinoma metastases (9/10) and some astrocytomas (7/13), pituitary tumours (4/9) and lung cancer metastases (5/11) had tumour cells that reacted with one or more of the antibodies used. Around 43% of the meningiomas and 25% of the glioblastomas expressed srp 72 only. Sole expression of srp 27, alpha B-crystallin or ubiquitin was seen in several tumours. Some meningiomas (3/23) and breast cancer metastases (4/10) co-expressed srp 72 and srp 27, and 1/3 of the glioblastomas co-expressed srp 27 and alpha B-crystallin. We conclude that primary and metastatic tumours of the brain produce stress-related proteins and that certain tumours concurrently express two or more srp's.
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Affiliation(s)
- S Kato
- Division of Neuropathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
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22
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Hanash SM, Strahler JR, Chan Y, Kuick R, Teichroew D, Neel JV, Hailat N, Keim DR, Gratiot-Deans J, Ungar D. Data base analysis of protein expression patterns during T-cell ontogeny and activation. Proc Natl Acad Sci U S A 1993; 90:3314-8. [PMID: 8475073 PMCID: PMC46290 DOI: 10.1073/pnas.90.8.3314] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have developed a data base of lymphoid proteins detectable by two-dimensional polyacrylamide gel electrophoresis. The data base contains two-dimensional patterns and derived information pertaining to polypeptide constituents of unstimulated and stimulated mature T cells and immature thymocytes, single-cell-derived T- and B-cell clones, leukemia cells, and lymphoid cell lines. Using this data base, we have compared the protein constituents of mature T cells and immature thymocytes before and after mitotic stimulation. A subset of polypeptides that are induced in mature T cells following mitotic stimulation were found to be constitutively expressed in immature thymocytes. Other polypeptides exhibited differences in their expression between mature and immature thymocytes in a manner unrelated to proliferation. The identity of several constitutively expressed or mitotically induced proteins in lymphoid cells was established by microsequencing. These initial findings point to significant differences in the molecular pathways leading to proliferation between mature and immature T cells. The construction of this database should facilitate further studies of lymphoid differentiation and function.
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Affiliation(s)
- S M Hanash
- Department of Pediatrics, University of Michigan School of Medicine, Ann Arbor
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23
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Delhaye M, Gulbis B, Galand P, Mairesse N. Expression of 27-kD heat-shock protein isoforms in human neoplastic and nonneoplastic liver tissues. Hepatology 1992; 16:382-9. [PMID: 1639347 DOI: 10.1002/hep.1840160216] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previous study of rat liver during chemically induced hepatocarcinogenesis has shown that expression of isoforms of the 27-kD heat-shock protein was greater in neoplastic nodules and in hepatocellular carcinoma than in control livers. In this study, various human neoplastic and nonneoplastic liver tissues were investigated with electrophoresis after amino acid labeling to evaluate the expression of 27-kD heat-shock protein isoforms. This revealed that human liver contains 27-kD proteins that are recognized by a polyclonal antibody raised against human 27-kD heat-shock protein. Basal levels of fluorographical and immunostaining intensity of the 27-kD heat-shock protein spots (respectively, after [3H]leucine or 32P incorporation or as checked with a specific human 27-kD heat-shock protein antibody) were higher in hepatomas than in non-tumorous liver. Phosphorylation patterns of the 27-kD heat-shock protein isoforms were, however, similar in hepatocellular carcinoma and in uninvolved surrounding liver. Heat inducibility of the 27-kD heat-shock protein, tested in one case of liver cell adenoma and in the surrounding liver, was also preserved in both tissues. The role of the overexpression of 27-kD heat-shock protein in neoplastic liver tissues remains unknown. We propose, as a working hypothesis, that it is related to the resistant phenotype acquired by some tumors during malignant progression.
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Affiliation(s)
- M Delhaye
- Department of Medicosurgical Gastroenterology, Erasme Hospital, Brussels, Belgium
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24
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Yufu Y, Nishimura J, Nawata H. High constitutive expression of heat shock protein 90 alpha in human acute leukemia cells. Leuk Res 1992; 16:597-605. [PMID: 1635378 DOI: 10.1016/0145-2126(92)90008-u] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The constitutive expression of the genes for four heat shock proteins (hsps) was studied in leukemia cell lines, cells obtained from patients with acute leukemia, and normal blood cells by means of Northern-blot analysis. Western-blot analysis with hsp90 antibody showed that the leukemia cells contained larger amounts of hsp90 than the normal peripheral mononuclear cells. The expression of the hsp90 alpha gene was enhanced in the leukemia cell lines and the acute leukemia cells from patients as compared with the normal blood cells. In contrast, the expression of the hsp90 beta gene could hardly be recognized in either the acute leukemia cells or the normal blood cells. An increased expression of hsp70 gene was observed in only one patient. The expression of the hsp27 gene was enhanced in one-half the patients with common acute lymphoblastic leukemia. Thus, exclusively the hsp90 alpha gene was expressed highly in the leukemia cells, indicating its association with cellular proliferation.
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MESH Headings
- Acute Disease
- Adult
- Aged
- Blotting, Northern
- Blotting, Western
- Cell Division
- Female
- Gene Expression
- Heat-Shock Proteins/blood
- Heat-Shock Proteins/genetics
- Heat-Shock Proteins/metabolism
- Humans
- Leukemia/genetics
- Leukemia/metabolism
- Leukemia/pathology
- Leukemia, Megakaryoblastic, Acute/metabolism
- Leukemia, Monocytic, Acute/metabolism
- Leukemia, Myeloid, Acute/metabolism
- Leukocytes, Mononuclear/metabolism
- Male
- Middle Aged
- Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/pathology
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Affiliation(s)
- Y Yufu
- Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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25
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Kato M, Herz F, Kato S, Hirano A. Expression of stress-response (heat-shock) protein 27 in human brain tumors: an immunohistochemical study. Acta Neuropathol 1992; 83:420-2. [PMID: 1575019 DOI: 10.1007/bf00713535] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This report concerns the expression of the low molecular weight stress-response (heat-shock) protein 27 (srp 27) in a variety of human brain tumors. Immunohistochemical techniques were used; cells of the breast cancer line MCF7 served as positive controls. The reaction product was found exclusively in the cytoplasm. Srp 27 was detected in 5/5 breast tumor metastases to the brain and in 5/21 meningiomas. The protein was also detected in 5/11 glioblastomas and 2/5 pituitary adenomas. By comparison, positive staining was observed in only 1/15 astrocytomas and 1/7 medulloblastoma and no reaction was seen with the oligodendrogliomas, schwannomas and gangliogliomas tested. These observations demonstrate that srp 27 is expressed by certain primary intracranial tumors.
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Affiliation(s)
- M Kato
- Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10467
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26
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Bitar KN, Kaminski MS, Hailat N, Cease KB, Strahler JR. Hsp27 is a mediator of sustained smooth muscle contraction in response to bombesin. Biochem Biophys Res Commun 1991; 181:1192-200. [PMID: 1722399 DOI: 10.1016/0006-291x(91)92065-r] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have identified the low MW 27 kD heat shock protein as a major phosphoprotein constituent of smooth muscle and have investigated its potential role in agonist induced smooth muscle contraction. The neuropeptides bombesin and substance P, which are present in neurons of the anorectal region, induce contraction of isolated smooth muscle cells from this region by activating different intracellular pathways. Substance P-induced contraction is 1,4,5-inositol trisphosphate (IP3)/calmodulin dependent, while contraction induced by bombesin is mediated by a protein kinase C (PKC)-dependent pathway. The sustained contraction induced by bombesin or exogenous PKC was blocked by preincubation of cells with monoclonal antibodies to hsp27, while the transient contraction induced by substance P or IP3 was unaffected by the antibodies. Preincubation with isotype matched control antibodies had no inhibitory effect on contraction induced in response to the agents used. These data support a novel role for hsp27 in the non calmodulin mediated sustained contraction induced by bombesin or PKC.
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Affiliation(s)
- K N Bitar
- Division of Pediatric Gastroenterology, University of Michigan Medical Center, Ann Arbor 48109-0658
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27
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Hanash SM, Strahler JR, Neel JV, Hailat N, Melhem R, Keim D, Zhu XX, Wagner D, Gage DA, Watson JT. Highly resolving two-dimensional gels for protein sequencing. Proc Natl Acad Sci U S A 1991; 88:5709-13. [PMID: 2062849 PMCID: PMC51947 DOI: 10.1073/pnas.88.13.5709] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Two-dimensional (2D) PAGE, using carrier ampholytes for the first-dimension separation, has provided a tool for the simultaneous analysis of cellular proteins. To extend the utility of 2D PAGE to the preparative level, we have investigated the use of immobilized pH gradients (IPG) for the first-dimension separation. The results we have obtained indicate that as much as 1 mg of cellular protein can be loaded onto a single IPG gel without loss of resolution. Mutant polypeptides previously detected in carrier ampholyte-based 2D gels were equally detectable in IPG-based 2D gels. With IPG gels several hundred cellular polypeptides can be isolated, from as few as 10 gels, in sufficient amount for sequencing with current sequencing technology. We therefore conclude that IPG greatly enhances the prospects for the large-scale sequencing of cellular proteins for the development of 2D gel-related protein data bases and for the identification of new polypeptide gene products, with the attendant implications for a genome sequencing effort.
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Affiliation(s)
- S M Hanash
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor 48109-0510
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28
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Affiliation(s)
- J Winfield
- Division of Rheumatology and Immunology, University of North Carolina, Chapel Hill 27599
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29
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Strahler JR, Kuick R, Hanash SM. Diminished phosphorylation of a heat shock protein (HSP 27) in infant acute lymphoblastic leukemia. Biochem Biophys Res Commun 1991; 175:134-42. [PMID: 1998499 DOI: 10.1016/s0006-291x(05)81211-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have previously reported lack of expression of a polypeptide designated L3 in infant acute lymphoblastic leukemia (ALL). Expression of L3 occurred predominantly in older children with pre-B ALL. We have recently reported the expression during B cell ontogeny of two other polypeptides, designated L2 and L4 with a similar Mr as L3, which were identified as phosphorylated and non-phosphorylated forms respectively of the low Mr heat shock protein. hsp27. In this study we have characterized L3 and identified it as another phosphorylated form of hsp27. The two phosphorylated forms appear to be differentially expressed in acute leukemia. L3 levels in infants who expressed hsp27 isoforms L2 and L4 were significantly diminished compared to levels in older children with an equivalent amount of hsp27. We conclude that leukemic cells in infant ALL exhibit a unique pattern of phosphorylation of hsp27 expressed at a pre-B cell stage of differentiation.
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Affiliation(s)
- J R Strahler
- Department of Pediatrics, University of Michigan, Ann Arbor 48109
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30
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Abstract
At birth, the immune system is biased toward recognition of microbial antigens in order to protect the host from infection. Recent data suggest that an important initial line of defense in this regard involves autologous stress proteins, especially conserved peptides of hsp60, which are presented to T cells bearing gamma delta receptors by relatively nonpolymorphic class lb molecules. Natural antibodies may represent a parallel B cell mechanism. Through an evolving process of "physiological" autoreactivity and selection by immunodominant stress proteins common to all prokaryotes, B and T cell repertoires expand during life to meet the continuing challenge of infection. Because stress proteins of bacteria are homologous with stress proteins of the host, there exists in genetically susceptible individuals a constant risk of autoimmune disease due to failure of mechanisms for self-nonself discrimination. That stress proteins actually play a role in autoimmune processes is supported by a growing body of evidence which, collectively, suggests that autoreactivity in chronic inflammatory arthritis involves, at least initially, gamma delta cells which recognize epitopes of the stress protein hsp60. Alternate mechanisms for T cell stimulation by stress proteins undoubtedly also exist, e.g., molecular mimicry of the DR beta third hypervariable region susceptibility locus for rheumatoid arthritis by a DnaJ stress protein epitope in gram-negative bacteria. While there still is confusion with respect to the most relevant stress protein epitopes, a central role for stress proteins in the etiology of arthritis appears likely. Furthermore, insight derived from the work thus far in adjuvant-induced arthritis already is stimulating analyses of related phenomena in autoimmune diseases other than those involving joints. Only limited data are available in the area of humoral autoimmunity to stress proteins. Autoantibodies to a number of stress proteins have been identified in SLE and rheumatoid arthritis, but their pathogenetic significance remains to be established. Nevertheless, the capacity of certain stress proteins to bind to multiple proteins in the nucleus and cytoplasm both physiologically and during stress or injury to cells, suggests that stress proteins may be important elements in the "immunogenic particle" concept of the origin of antinuclear and other autoantibodies. In short, this fascinating group of proteins, so mysterious only a few years ago, has impelled truly extraordinary new lines of investigation into the nature of autoimmunity and autoimmune disease.
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Affiliation(s)
- J B Winfield
- Thurston Arthritis Research Center, Division of Rheumatology and Immunology, University of North Carolina, Chapel Hill 27599
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