1
|
Horvat S, Kos J, Pišlar A. Multifunctional roles of γ-enolase in the central nervous system: more than a neuronal marker. Cell Biosci 2024; 14:61. [PMID: 38735971 PMCID: PMC11089681 DOI: 10.1186/s13578-024-01240-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 04/27/2024] [Indexed: 05/14/2024] Open
Abstract
Enolase, a multifunctional protein with diverse isoforms, has generally been recognized for its primary roles in glycolysis and gluconeogenesis. The shift in isoform expression from α-enolase to neuron-specific γ-enolase extends beyond its enzymatic role. Enolase is essential for neuronal survival, differentiation, and the maturation of neurons and glial cells in the central nervous system. Neuron-specific γ-enolase is a critical biomarker for neurodegenerative pathologies and neurological conditions, not only indicating disease but also participating in nerve cell formation and neuroprotection and exhibiting neurotrophic-like properties. These properties are precisely regulated by cysteine peptidase cathepsin X and scaffold protein γ1-syntrophin. Our findings suggest that γ-enolase, specifically its C-terminal part, may offer neuroprotective benefits against neurotoxicity seen in Alzheimer's and Parkinson's disease. Furthermore, although the therapeutic potential of γ-enolase seems promising, the effectiveness of enolase inhibitors is under debate. This paper reviews the research on the roles of γ-enolase in the central nervous system, especially in pathophysiological events and the regulation of neurodegenerative diseases.
Collapse
Affiliation(s)
- Selena Horvat
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Janko Kos
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia
- Department of Biotechnology, Jožef Stefan Institute, Jamova Cesta 39, 1000, Ljubljana, Slovenia
| | - Anja Pišlar
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia.
| |
Collapse
|
2
|
Abstract
A malignant schwannoma of the right acoustic nerve of a dog is described. The neoplasm was found during necropsy of a 12-year-old, spayed, female Labrador Retriever that experienced a sudden onset of severe pain in the neck and upon opening the mouth. Concurrent mild hind limb ataxia also was present. The tumor had infiltrative growth, and the spindle-shaped neoplastic cells were arranged in sheets and concentric whorls. Immunohistochemical staining of the neoplastic spindle cells was positive for S-100 antigen, neuron-specific enolase, and glial fibrillary acidic protein.
Collapse
Affiliation(s)
- Therese Ottinger
- Department of Biomedical Sciences and Veterinary Public Health, Division of Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | | | | |
Collapse
|
3
|
Pal-Bhowmick I, Mehta M, Coppens I, Sharma S, Jarori GK. Protective properties and surface localization of Plasmodium falciparum enolase. Infect Immun 2007; 75:5500-8. [PMID: 17785475 PMCID: PMC2168313 DOI: 10.1128/iai.00551-07] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Revised: 06/20/2007] [Accepted: 08/15/2007] [Indexed: 11/20/2022] Open
Abstract
The enolase protein of the human malarial parasite Plasmodium falciparum has recently been characterized. Apart from its glycolytic function, enolase has also been shown to possess antigenic properties and to be present on the cell wall of certain invasive organisms, such as Candida albicans. In order to assess whether enolase of P. falciparum is also antigenic, sera from residents of a region of Eastern India where malaria is endemic were tested against the recombinant P. falciparum enolase (r-Pfen) protein. About 96% of immune adult sera samples reacted with r-Pfen over and above the seronegative controls. Rabbit anti-r-Pfen antibodies inhibited the growth of in vitro cultures of P. falciparum. Mice immunized with r-Pfen showed protection against a challenge with the 17XL lethal strain of the mouse malarial parasite Plasmodium yoelii. The antibodies raised against r-Pfen were specific for Plasmodium and did not react to the host tissues. Immunofluorescence as well as electron microscopic examinations revealed localization of the enolase protein on the merozoite cell surface. These observations establish malaria enolase to be a potential protective antigen.
Collapse
Affiliation(s)
- Ipsita Pal-Bhowmick
- Department of Biological Sciences, TIFR, Homi Babha Road, Colaba, Mumbai 400 005, India
| | | | | | | | | |
Collapse
|
4
|
Abstract
Dr. Lucien Rubinstein is best remembered for his significant contributions to the field of neuropathology, particularly in the classification of nervous system tumors. His accomplishments in basic neuro-oncology and in the formulation of diagnostic principles reflected a unique talent for synthesizing fundamental clinicopathological concepts based on skillful diagnostic investigation and a thorough understanding of neurobiology. Dr. Rubinstein was the leader in the establishment of cell cultures from central nervous system (CNS) tumors. He meticulously analyzed both light and electron microscopic features of CNS tumors, recorded his findings, and patiently drew sketches to be shared generously with his colleagues and students. As a pioneer in neuropathology, in his work Dr. Rubinstein set the foundation for many enduring concepts in neurosurgery, neuro-oncology, neurology, and basic tumor biology.
Collapse
Affiliation(s)
- Melike Mut
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
| | | | | |
Collapse
|
5
|
Nonclercq D, Liénard V, Zanen J, Laurent G, Toubeau G. Phenotypic variations and dynamic topography of transformed cells in an experimental model of diethylstilbestrol-induced renal tumour in male Syrian hamster. THE HISTOCHEMICAL JOURNAL 2002; 34:487-97. [PMID: 12945731 DOI: 10.1023/a:1024757806464] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This work explores the phenotypic changes affecting transformed cells in an experimental model of diethylstilbestrol (DES)-induced renal tumours in male Syrian hamster. This estrogen-induced neoplasm presents an important cytological pleomorphism and its origin remains largely controversial. In order to characterize phenotypic variations during tumour progression, the occurrence of seven lineage markers was analysed by a morphometric approach in kidney sections of DES-exposed hamsters (6-11 months). S100 protein, neuron-specific enolase (NSE) and vimentin are expressed by a large percentage of malignant cells during tumour development. Glial fibrillary acidic protein (GFAP), protein gene product 9.5 (PGP 9.5) and desmin are mostly evidenced in advanced neoplasm whereas Leu 7 always presents a focal expression. As evidenced by double-label immunofluorescence, the coexpression of three important neuroectodermal lineage markers (S100, NSE and PGP 9.5) in earliest tumour buds points to a peripheral nerve sheath origin for this neoplasm thus confirming previously published data. For each marker, the fluctuations of expression levels during tumour progression as well as the spatial heterogeneity of distribution suggest variable phenotypic differentiation of transformed cell populations. This observation is largely corroborated by double-label immunofluorescence showing coexpression modification of several markers during tumour progression. This points to a complex dynamic and spatial self-organization of different phenotypes within neoplasms. Altogether, these results support the concept that DES-induced kidney tumours are not made of unstructured cell populations but represent adaptive complex dynamic biosystems.
Collapse
Affiliation(s)
- Denis Nonclercq
- Service d'Histologie, Faculté de Médecine et de Pharmacie, Université de Mons-Hainaut, Avenue du Champ de Mars, B-7000 Mons, Belgium
| | | | | | | | | |
Collapse
|
6
|
Deloulme JC, Helies A, Ledig M, Lucas M, Sensenbrenner M. A comparative study of the distribution of alpha- and gamma-enolase subunits in cultured rat neural cells and fibroblasts. Int J Dev Neurosci 1997; 15:183-94. [PMID: 9178037 DOI: 10.1016/s0736-5748(96)00090-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We report the presence and distribution of alpha (ubiquitous) and gamma (neuron-specific) subunits of the dimeric glycolytic enzyme enolase (2-phospho-D-glycerate hydrolase) in cultured neural cells. The gamma gamma enolase is found in vivo at high levels only in neurons and neuroendocrine cells. Neuronal cells in culture also contain relatively high levels of alpha gamma and gamma gamma enolase. Here we show, by enzymatic and immunological techniques, that the gamma subunit also is expressed in cultured rat astrocytes and meningeal fibroblasts and, as we previously reported, in oligodendrocytes. Both neuron-specific isoforms alpha gamma and gamma gamma are expressed in all these cells, but the alpha alpha isoform accounts for the major part of total enolase activity. The sum of alpha gamma and gamma gamma enolase activities increases with time in culture. i.e. maturation processes, reaching the highest level in oligodendrocytes (40% of total enolase activity) and 15 and 10% of total enzymatic activity in astrocytes and fibroblasts, respectively. The gamma enolase transcripts were found not only in cultured neuronal cells but also in cultured oligodendrocytes astrocytes, and meningeal fibroblasts. Our data indicate that neuron-specific enolase should be used with caution as a specific marker for neuronal cell differentiation.
Collapse
Affiliation(s)
- J C Deloulme
- Laboratoire de Neurobiologie Ontogénique, Centre de Neurochimie du CNRS, Strasbourg, France
| | | | | | | | | |
Collapse
|
7
|
Vinores SA, Derevjanik NL, Mahlow J, Hackett SF, Haller JA, deJuan E, Frankfurter A, Campochiaro PA. Class III beta-tubulin in human retinal pigment epithelial cells in culture and in epiretinal membranes. Exp Eye Res 1995; 60:385-400. [PMID: 7789418 DOI: 10.1016/s0014-4835(05)80095-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The class III beta-tubulin isotype (beta III) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in 1 day-old primary cultures; however, beta III is present in RPE cells in 5-day primary cultures and in passaged RPE cells grown in monolayer cultures as determined by immunohistochemistry and Western blotting. beta III-positivity in cultured RPE cells is not affected by cell density or hydroxyurea- or retinoic-acid-mediated growth inhibition, but only a few cells weakly express beta III in cyclohexamide-treated cultures and RPE cells maintained in serum-free medium fail to produce beta III. When monolayer-cultured RPE cells grown in normal, serum-containing medium, are transferred to irradiated bovine vitreous, beta III is undetectable in most cells. Cultured RPE cells coexpress beta III with keratin and cellular retinaldehyde-binding protein (both RPE cell markers), but not with glial fibrillary acidic protein. Some cultured RPE cells also express neuron-specific (gamma) enolase, which is neuron-associated but not neuron-specific, and occasional cells in confluent or super-confluent cultures contain the 200-kDa neurofilament protein. Retinal glia, fibroblasts, endothelial cells, and smooth muscle cells do not express beta III under the same culture conditions. We have detected beta III in 45 of 56 epiretinal membranes, frequently in cells with a bipolar or dedifferentiated morphology, where its expression coincides with other RPE cell-associated antigens. Cells with morphological features resembling normal RPE cells in epiretinal membranes are usually negative for beta III, but RPE cells appearing to be in the early stages of dedifferentiation express the isotype weakly. Electron microscopic immunocytochemistry localizes beta III to microtubules, ribosomes and cytoplasm. beta III may be a useful marker for recognizing the fraction of RPE cells in epiretinal membranes that are no longer identifiable by morphological criteria or other RPE cell markers. These findings demonstrate that mature human RPE cells have the capacity to express a neuron-associated gene in response to conditions that promote dedifferentiation.
Collapse
Affiliation(s)
- S A Vinores
- Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287-9289, USA
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Geyer C, Hafner A, Pfleghaar S, Hermanns W. Immunohistochemical and ultrastructural investigation of granular cell tumours in dog, cat, and horse. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1992; 39:485-94. [PMID: 1455940 DOI: 10.1111/j.1439-0450.1992.tb01197.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Six canine, one feline and one equine granular cell tumours (GCTs) were investigated electron microscopically and immunohistochemically. The tumours were tested for reactivity with monoclonal antibodies against vimentin and desmin and with polyclonal antibodies against cytokeratin, S-100 protein, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE). All GCTs were characterized by their PAS positive cytoplasmic granules in light microscopy, which in electron microscopy appeared as lysosome-like granules. In each case two canine GCTs were stained by the antibody against cytokeratin, vimentin and S-100 protein. Cells of the equine GCT showed reactivity with the antiserum against S-100 protein. In the feline GCT no reactivity with any of the antibodies tested was observed. These differences of the immunohistochemical reactions of GCTs suggest a nonuniform histogenesis of GCTs in domestic animals. The reactivity of the tumour cells with the antiserum against NSE is discussed.
Collapse
Affiliation(s)
- C Geyer
- Institut für Tierpathologie, Ludwig-Maximilians-Universität München
| | | | | | | |
Collapse
|
9
|
Zieske JD, Bukusoglu G, Yankauckas MA, Wasson ME, Keutmann HT. Alpha-enolase is restricted to basal cells of stratified squamous epithelium. Dev Biol 1992; 151:18-26. [PMID: 1577187 DOI: 10.1016/0012-1606(92)90209-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have developed a monoclonal antibody against a 50-kDa protein that binds preferentially to basal cells in the limbus of rat, rabbit, and human corneas (J. D. Zieske, G. Bukusoglu, and M. A. Yankauckas, Invest. Ophthalmol. Visual Sci. 33, 143-152, 1992). Here we report on the purification and identification of the antigen. The 50-kDa antigen was purified from rabbit limbal and corneal epithelium using HPLC methodology including anion exchange (DEAE) followed by reverse-phase (C18) chromatography. The purified 50-kDa protein was then digested with endoproteinase Lys-C, and a reproducible profile comprising approximately 20 peptides was observed by reverse-phase HPLC of the digest. Sequence analysis of five peptides ranging in length from 4 to 20 residues revealed that the 50-kDa protein was alpha-enolase, a glycolytic enzyme. Overall, 57 amino acids were identified with a 95% sequence homology. Localization of alpha-enolase in rat epithelium by immunofluorescence microscopy demonstrated that simple epithelium contained low or undetectable levels of the enzyme. Stratified squamous epithelium, however, showed high levels of alpha-enolase, which was localized specifically to cells of the basal layer. Epidermal, corneal limbal, oral mucosal, vaginal, and laryngeal epithelium all showed cytoplasmic binding specific to the basal cells. These data indicate that the glycolytic enzyme alpha-enolase is preferentially localized in the basal cell layer of stratified squamous epithelium and suggest that glycolytic activity is concentrated in these cells. The localization pattern suggests that a major change in metabolism occurs as cells leave the mitotically active basal cell layer and migrate toward terminal differentiation in the suprabasal cell layers.
Collapse
Affiliation(s)
- J D Zieske
- Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114
| | | | | | | | | |
Collapse
|
10
|
Abstract
In this progress report, some of the most commonly used antibodies are discussed in regard to their immunohistochemical application to human neurooncology. The importance of determining the spectrum of antibody immunoreactivity in a wide panel of normal, reactive, and neoplastic tissues is stressed. in atypical and aberrant cases, immunopositivity needs to be interpreted with caution and in the context of all other available data. The demonstration of a well-characterized, cell type-specific marker in a tumor reflects not so much its cytogenesis as its differentiation potential and its capacity for metaplasia. The relation of an abnormal or aberrant expression of antigenic determinants to the process of neoplasia raises a number of intriguing questions to which research in the next few years will likely provide answers.
Collapse
Affiliation(s)
- L J Rubinstein
- Department of Pathology, University of Virginia School of Medicine, Charlottesville 22908
| |
Collapse
|