The Na+/HCO3- co-transporter is protective during ischemia in astrocytes

Autor: Alysson R. Muotri, Juan Wang, Gabriel G. Haddad, Priti Azad, Huiwen W. Zhao, Orit Poulsen, Beatriz C.G. Freitas, Hang Yao
Rok vydání: 2016
Předmět:
0301 basic medicine
NBC
Messenger
Stimulation
Membrane Potentials
0302 clinical medicine
Psychology
Induced pluripotent stem cell
Cells
Cultured
Sulfonamides
Cultured
Cell Death
General Neuroscience
Human brain
Hydrogen-Ion Concentration
Cell Hypoxia
Neuroprotection
Cell biology
Stroke
medicine.anatomical_structure
Neuroprotective Agents
Benzamides
Neurological
Cognitive Sciences
Astrocyte
Programmed cell death
Cells
1.1 Normal biological development and functioning
Induced Pluripotent Stem Cells
Ischemia
iPSCs
ischemia
Neurotransmission
Article
03 medical and health sciences
Underpinning research
medicine
Humans
RNA
Messenger
Neurology & Neurosurgery
business.industry
Sodium-Bicarbonate Symporters
astrocytes
Neurosciences
penumbra
Fibroblasts
medicine.disease
Stem Cell Research
Brain Disorders
030104 developmental biology
Gene Expression Regulation
Astrocytes
RNA
business
Neuroscience
030217 neurology & neurosurgery
Popis: The sodium bicarbonate co-transporter (NBC) is the major bicarbonate-dependent acid-base transporter in mammalian astrocytes and has been implicated in ischemic brain injury. A malfunction of astrocytes could have great impact on the outcome of stroke due to their participation in the formation of blood brain barrier, synaptic transmission, and electrolyte balance in the human brain. Nevertheless, the role of NBC in the ischemic astrocyte death has not been well understood. In this work, we obtained skin biopsies from healthy human subjects and had their fibroblasts grown in culture and reprogrammed into human induced pluripotent stem cells (hiPSCs). These hiPSCs were further differentiated into neuroprogenitor cells (NPCs) and then into human astrocytes. These astrocytes express GFAP and S100β and readily propagate calcium waves upon mechanical stimulation. Using pH sensitive dye BCECF [2',7'-bis-(carboxyethyl)-5-(and-6)-carboxyfluorescein] and qPCR technique, we have confirmed that these astrocytes express functional NBC including electrogenic NBC (NBCe). In addition, astrocytes exposed to an ischemic solution (IS) that mimics the ischemic penumbral environment enhanced both mRNA and protein expression level of NBCe1 in astrocytes. Using IS and a generic NBC blocker S0859, we have studied the involvement of NBC in IS-induced human astrocytes death. Our results show that a 30 µM S0859 induced a 97.5±1.6% (n=10) cell death in IS- treated astrocytes, which is significantly higher than 43.6 ± 4.5%, (n=10) in the control group treated with IS alone. In summary, a NBC blocker exaggerates IS-induced cell death, suggesting that NBC activity is essential for astrocyte survival when exposed to ischemic penumbral environment.
Databáze: OpenAIRE
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