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Showing 6 results for Astrocytes
Azadeh Sajadian, Maryam Jafarian, Babak Khodaie, Shahin Mohammad Sadeghi, Amir Ghaemi, Volume 2, Issue 2 (6-2014)
Abstract
Introduction: The ability to induce pluripotency in somatic cells by reprogramming factors offers new opportunities for drug discovery and cell therapy. Induced pluripotent stem cells have the potential to differentiate to various cell types, such as neural and glial cells. Astrocytes, the major glial cells of the central nervous system, play an important role in the function of the brain by regulating of extracellular ions and neurotransmitters, feeding and protection of neurons as well as modulating the activity of microglia. Microglia over-activation can be resulted in brain inflammation with subsequent susceptibility to epileptic seizures. Hypothesis: For many years, embryonic Stem cell transplantation has been examined to prevent seizure attacks in epilepsy. These studies have indicated that adult cells from patient have the ability to be transformed to embryonic stage and convert to a pluripotent stem cell by using some Transcription factors (such as Oct4, Sox2, Nanog, Rex1, Klf, c-Myc and LIN28). Accordingly, fibroblasts from an epileptic have also been reprogrammed to embryonic stage. The resulting iPS cells are isogenic to patient and are able to transform to neurons or glia in a suitable culture condition. Previous studies on ES cell therapy have focused more on neurons than astrocytes. Astrocytes, by secretion of glial cell-derived neurotrophic factor, not only regulate the different microglial activities, such as proliferation, migration and cell adhesion, but can also reduce destructive effects of microglia. Conclusion: In this hypothesis, we suggest a reprogramming system for generating functional astrocyte from human pluripotent stem cell in the presence of neural growth factors. We hypothesize that these cells might reduce neuroinflammation induced by microglia and subsequent susceptibility to seizure. The reprogrammed cells could be used in cell replacement therapy of epilepsy.
Mahmoud Lotfinia, Ahmad Ali Lotfinia, Babak Khodaie, Milad Ahmadi, Sina Asaadi, Maryam Jafarian, Volume 2, Issue 3 (9-2014)
Abstract
Introduction: Spreading depression is a transient and self-propagating wave of neuronal and glial depolarization, followed by a temporary loss of brain activities. Spreading depression is known by a huge redistribution of ions between extra- and intracellular spaces and spreads at the velocity of 2-3 mm/min in all directions. Investigations indicate the role of spreading depression in several neurological disorders, including migraine with aura, epilepsy, traumatic brain injuries, transient global amnesia, stroke, and spinal cord diseases. Conclusion: Despite decades of research and hundreds of reports on the mechanism of spreading depression propagation, the exact mechanism of propagation still need to be elucidated. The present study reviews a group of these observations, in order to give some new insights into the complex mechanism of the propagation of spreading depression.
Ali Jahanbazi Jahan-Abad, Parastu Morteza Zadeh, Elham Mohammadzadeh, Zabihollah Khaksar, Shahin Mohammad Sadeghi, Sajad Sahab Negah, Volume 4, Issue 4 (12-2016)
Abstract
Introduction: Astrocytes are the most abundant cells in the mammalian brain and play important roles in regulating neuronal signaling, protecting neurons, and determining the fate of neural precursors. Astrocytes are one of the best candidates for cell therapy. Three-dimensional (3D) scaffolds are a synthetic matrix which provided a biocompatible, biodegradable, and non-toxic 3D environment for a variety of cells. In the present study, we isolated astrocytes from rat neocortex and assessed the proliferation rate of astrocytes in 3D dimensional environment. Materials and Methods: Astrocytes isolated from adult rat neocortex. The isolated cells was cultured in DMEM/F12 medium supplement with 10% FBS. Astrocytes were confirmed by expression of GFAP (glial fibrillary acidic protein), assessed by immunocytochemistry. After the 3th passage, the astrocytes were cultured in 3D and two - dimensional (2D) cultures and MTS assay was used to determined cell proliferation. Results: The expression of GFAP marker was confirmed by immunocytochemistry assay. Our results showed that surface plating of astrocytes with 0.15% Pura Matrix showed significantly greater cell proliferation in comparison with 2D culture. Conclusion: These findings indicate the potential of the astrocytes which was cultured in 3D for using in cell transplantation.
Atena Adel Rastkhiz, Volume 5, Issue 2 (4-2017)
Abstract
Epilepsy is neurological disorders that afflict many people around the world with a higher prevalence rate in children and in low income countries. Temporal lobe epilepsy (TLE) is result from hippocampal sclerosis is a neurological disorder with difficult treatment. Stem cells can transform into any type of cells such as glial cells, consequently stem cells can use for medical treatment. Stem cell therapy in epilepsy result in prophylaxis against epilepsy and improve cognitive function after seizures. Astrocytes have many roles in the brain such as protection of neurons and endothelial cells, feeding, inhibiting over activation of microglia, modulate k changes, managing of extracellular ions, regulating density of y-amino butyric acid, glutamate and adenosine. Excessive activation of microglia cause brain inflammation that lead to epileptic seizures. Adult cell from patient have the capability to alter to embryonic cell and become stem cell by using transcription factors. Astrocytes by secretion of glial cell derived neurotrophic factor (GDNF), controlling the proliferation, adheration and movement of microglial cells .also astrocytes reduce generation of lipopolysaccharide (LPS), IL1B, TNF .astrocytes are as a source of protection mediators that decreased neuroinflammation. In this hypothesis I suggest using stem cell therapy in epilepsy to reduce neuroinflammation induced by microglia and reduce occurrence of seizures.
Noushin Gashmardi, Mohammad Amin Edalatmanesh, Volume 7, Issue 4 (10-2019)
Abstract
Introduction: Spinal cord injury (SCI) following traumatic events is associated with the limited therapeutic options and sever complications, which can be partly due to inflammatory response. Therefore, this study aims to explore the role of inflammation in spinal cord injury. The findings showed that the pathological conditions of nervous system lead to activation of microglia, astrocyte, neutrophil, and macrophages. It is also may be mediated by glial and lead to neuronal injury and death through production of proinflammatory factors, such as cytokines (key factors in the onset, progression and suppression of inflammation) and chemokines. Inflammation is a major component of spinal cord injury; although it is possible that inflammation has beneficial effects, such as phagocytosis of apoptotic cells and pathogens clearance. However, this could contribute to spreading, amplifying, and chronicity of tissue damage, via production of neurotoxic factors. Conclusion: It seems that inflammation has a major role in the injured spinal cord. Identifying effective cells in the inflammatory responses as well as their numbers, nature of their actions, and types of released inflammatory factors, along with the discovery of appropriate coping strategies against them, will increase the hope to repair spinal cord injuries in future.
Samira Ramazi, Fatemeh Arani, Atlasi Safaei, Zeinab Abbasi, Zahra Heidari, Hanieh Ghasemian Nafchi, Homa Mohammadsadeghi, Fariba Karimzadeh, Volume 9, Issue 2 (3-2021)
Abstract
Introduction: Astrocytes are cells with distinct morphological and functional properties in certain areas of the brain and play regulatory roles, such as neurogenesis, synaptogenesis, control of the blood-brain barrier permeability, and maintaining extracellular homeostasis. Moreover, astrocytes play a key role in the development and modulation of neural circuits through communicating with axons, dendrites, and synapses according to the needs of the surrounding cells. Furthermore, astrocytes play an essential role in synaptic plasticity, and memory formation via the modulation of neural function. Mature astrocytes are activated following central nervous system damage and changed to reactive astrocytes type A1 and A2. Supporting roles of reactive astrocytes may shift to toxic functions and finally cause the progression of neurological diseases. Neurotransmitter disorder, abnormal brain development, and regeneration of synaptic structures are observed in the brains of patients with neuropsychological diseases. Extensive studies have pointed to the role of astrocytes in depression, schizophrenia, and drug dependence. On the other hand, astrocytes are an important factor in neuronal damage in neurodegenerative diseases. Neurological and radiological studies have shown that these diseases are associated with severe inflammation and astrocytes are among the most important cells that cause inflammation. Reactive astrocytes play a role in the pathology of various neurological diseases, such as Alzheimer's disease, Parkinson's disease, lateral amyotrophic sclerosis, multiple sclerosis, and Huntington's. Alterations in neurotransmitters, cellular connections, receptors, signaling pathways (especially in the field of inflammation), secretion of inflammatory factors, aqueous channels, secretion of growth factors, protein deposition, ionic homeostasis, and finally, changes in the size and number of astrocytes have been considered as the most important pathogenic mechanisms in astrocytes. Conclusion: Regulation of reactive astrocytes could be an effective clinical strategy for the treatment of neurological and psychological diseases.
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