Oxygen, a Key Factor Regulating Cell Behavior during Neurogenesis and Cerebral Diseases

Abstract

Oxygen is vital to maintain the normal functions of almost all the organs, especially for brain which is one of the heaviest oxygen consumers in the body. The important roles of oxygen on the brain are not only reflected in the development, but also showed in the pathological processes of many cerebral diseases. In the current review, we summarized the oxygen levels in brain tissues tested by real-time measurements during the embryonic and adult neurogenesis, the cerebral diseases, or in the hyperbaric/hypobaric oxygen environment. Oxygen concentration is low in fetal brain (0.076–7.6 mmHg) and in adult brain (11.4–53.2 mmHg), decreased during stroke, and increased in hyperbaric oxygen environment. In addition, we reviewed the effects of oxygen tensions on the behaviors of neural stem cells (NSCs) in vitro cultures at different oxygen concentration (15.2–152 mmHg) and in vivo niche during different pathological states and in hyperbaric/hypobaric oxygen environment. Moderate hypoxia (22.8–76 mmHg) can promote the proliferation of NSCs and enhance the differentiation of NSCs into the TH-positive neurons. Next, we briefly presented the oxygen-sensitive molecular mechanisms regulating NSCs proliferation and differentiation recently found including the Notch, Bone morphogenetic protein and Wnt pathways. Finally, the future perspectives about the roles of oxygen on brain and NSCs were given.

Acute reduction in oxygen tension enhances the induction of neurons from human fibroblasts

“…These levels are finely tuned and if altered could lead to irreversible damages in brain functions (Masamoto and Tanishita, 2009). The in vitro beneficial effects of low O 2 tensions similar to physiological levels on cell survival, proliferation and differentiation in neural precursor cells has been previously reported ((Review Zhang et al, 2011)). Furthermore, mild hypoxic conditions can increase the generation efficiency of iPSCs from human somatic cells (Yoshida et al, 2009).…”

Hyperbaric Oxygen Therapy Alleviates Carbon Monoxide Poisoning–Induced Delayed Memory Impairment by Preserving Brain-Derived Neurotrophic Factor–Dependent Hippocampal Neurogenesis

“…In this regard, the SGZ contains a rich plexus of blood vessels (42), which are one of the important components of the neurogenesis niche (14). A decrease in oxygen concentration around the vessels due to CO poisoning might thus jeopardize tissue microenvironment for the maintenance of neural stem cell characteristics in the SGZ (43). The HBO has recently been demonstrated (44) to enhance hippocampal neurogenesis in late stage ischemic stroke, via activation of the redox-sensitive hypoxiainducible factor-1α (HIF-1α)/β-catenin pathway, signaling implicated in differentiation of embryonic and neural stem cells (45).…”

Repetitive Long-Term Hyperbaric Oxygen Treatment (HBOT) Administered after Experimental Traumatic Brain Injury in Rats Induces Significant Remyelination and a Recovery of Sensorimotor Function

“…Recent studies also reported an HBOT-mediated stimulation of angiogenesis and neurogenesis following TBI [30], [31].…”