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Kandasamy M, Anusuyadevi M, Aigner KM, Unger MS, Kniewallner KM, de Sousa DMB, Altendorfer B, Mrowetz H, Bogdahn U, Aigner L. TGF-β Signaling: A Therapeutic Target to Reinstate Regenerative Plasticity in Vascular Dementia? Aging Dis 2020; 11:828-850. [PMID: 32765949 PMCID: PMC7390515 DOI: 10.14336/ad.2020.0222] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/22/2020] [Indexed: 12/11/2022] Open
Abstract
Vascular dementia (VaD) is the second leading form of memory loss after Alzheimer's disease (AD). Currently, there is no cure available. The etiology, pathophysiology and clinical manifestations of VaD are extremely heterogeneous, but the impaired cerebral blood flow (CBF) represents a common denominator of VaD. The latter might be the result of atherosclerosis, amyloid angiopathy, microbleeding and micro-strokes, together causing blood-brain barrier (BBB) dysfunction and vessel leakage, collectively originating from the consequence of hypertension, one of the main risk factors for VaD. At the histopathological level, VaD displays abnormal vascular remodeling, endothelial cell death, string vessel formation, pericyte responses, fibrosis, astrogliosis, sclerosis, microglia activation, neuroinflammation, demyelination, white matter lesions, deprivation of synapses and neuronal loss. The transforming growth factor (TGF) β has been identified as one of the key molecular factors involved in the aforementioned various pathological aspects. Thus, targeting TGF-β signaling in the brain might be a promising therapeutic strategy to mitigate vascular pathology and improve cognitive functions in patients with VaD. This review revisits the recent understanding of the role of TGF-β in VaD and associated pathological hallmarks. It further explores the potential to modulate certain aspects of VaD pathology by targeting TGF-β signaling.
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Affiliation(s)
- Mahesh Kandasamy
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
- Faculty Recharge Programme, University Grants Commission (UGC-FRP), New Delhi, India.
| | - Muthuswamy Anusuyadevi
- Molecular Gerontology Group, Department of Biochemistry, School of Life Sciences, Bharathidhasan University, Tiruchirappalli, Tamil Nadu, India.
| | - Kiera M Aigner
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Michael S Unger
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Kathrin M Kniewallner
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Diana M Bessa de Sousa
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Barbara Altendorfer
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Heike Mrowetz
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
| | - Ulrich Bogdahn
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
- Velvio GmbH, Regensburg, Germany.
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University.
- Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria.
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
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Selvaraj K, Manickam N, Kumaran E, Thangadurai K, Elumalai G, Sekar A, Radhakrishnan RK, Kandasamy M. Deterioration of neuroregenerative plasticity in association with testicular atrophy and dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis in Huntington's disease: A putative role of the huntingtin gene in steroidogenesis. J Steroid Biochem Mol Biol 2020; 197:105526. [PMID: 31715317 DOI: 10.1016/j.jsbmb.2019.105526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 12/22/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder mainly affecting the structure and functions of the striatum, cerebral cortex and hippocampus leading to movement disorders, cognitive dysfunctions and emotional disturbances. The onset of HD has been linked to a pathogenic CAG repeat expansion in the huntingtin (HTT) gene that encodes for the polyglutamine (polyQ) stretches in the huntingtin (Htt) protein. Notably, the neuropathogenic events of the mutant HTT gene appear to be primed during adulthood and magnified along the ageing process. While the normal Htt protein is vital for the neuronal differentiation and neuroprotection, experimental HD models and postmortem human HD brains have been characterized by neurodegeneration and defects in neuroregenerative plasticity in the basal ganglia and limbic system including the hippocampus. Besides gonadal dysfunctions, reduced androgen levels and abnormal hypothalamic-pituitary-gonadal (HPG) axis have increasingly been evident in HD. Recently, ageing-related changes in levels of steroid sex hormones have been proposed to play a detrimental effect on the regulation of hippocampal neurogenesis in the adult brain. Considering its adult-onset nature, a potential relationship between dysregulation in the synthesis of sex steroid hormones and the pathogenesis of the mutant HTT gene appears to be an important clinical issue in HD. While the hippocampus and testis are the major sites of steroidogenesis, the presence of Htt in both areas is conclusively evident. Hence, the expression of the normal HTT gene may take part in the steroidogenic events in aforementioned organs in the physiological state, whereas the mutant HTT gene may cause defects in steroidogenesis in HD. Therefore, this review article comprehends the potential relationship between the gonadal dysfunctions and abnormal hippocampal plasticity in HD and represents a hypothesis for the putative role of the HTT gene in the regulation of steroidogenesis in gonads and in the brain.
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Affiliation(s)
- Kaviya Selvaraj
- School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Nivethitha Manickam
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Elamathi Kumaran
- School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Kayalvizhi Thangadurai
- Department of Bio-Medical Science, Bharathidasan University, Tiruchirappalli, 620024, Tamil Nadu, India
| | - Gokul Elumalai
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Aravinthan Sekar
- Department of Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Risna Kanjirassery Radhakrishnan
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Mahesh Kandasamy
- School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India; Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India; Faculty Recharge Programme, University Grants Commission (UGC-FRP), New Delhi, India.
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