Induction of oxidative stress and apoptosis in the injured brain: potential relevance to brain regeneration in zebrafish

Abstract

In the recent years, zebra sh, owing to its tremendous adult neurogenic capacity, has emerged as a useful vertebrate model to study brain regeneration. Recent ndings suggest a signi cant role of the BDNF/TrkB signaling as a mediator of brain regeneration following a stab injury in the adult zebra sh brain. Since BDNF has been implicated in a plethora of physiological processes, we hypothesized that these processes are affected in the injured zebra sh brain. In this small study, we examined the indicators of oxidative stress and of apoptosis using biochemical assays, RT-PCR and IHC to re ect upon the impact of stab injury on oxidative stress levels and apoptosis in the injured adult zeba sh brain. Our results indicate induction of oxidative stress in the injured adult zebra sh brain. Also, apoptosis was induced in the injured brain as indicated by increased protein levels of cleaved caspase3 as well as enhanced mRNA levels of both proapoptotic and anti-apoptotic genes. This knowledge contributes to the overall understanding of adult neurogenesis in the zebra sh model and raises new questions pertaining to the compensatory physiological mechanisms in response to traumatic brain injury in the adult zebra sh brain.

Saffron Extract Attenuates Anxiogenic Effect and Improves Cognitive Behavior in an Adult Zebrafish Model of Traumatic Brain Injury

“…Accumulating evidence indicates that neurotrophins via TrK receptors could regulate regenerative processes [ 41 , 66 ]. BDNF mRNA is increased in neurons and in newborn neurons of the injured area after TBI in telencephalon of adult zebrafish, and this increase is maintained up to 15 dpi [ 39 ].…”

“…TBI induction in zebrafish results in a rapid proliferative response leading to neuronal regeneration [ 38 ]. This neurogenesis is preceded by an increase in the level of brain-derived neurotrophic factor (BDNF) expression [ 39 , 40 , 41 ]. Lesion of the dorsolateral telencephalon can completely recover 35 days after injury with Hu-positive newly generated neurons detected at the injury site [ 38 ].…”

Neurotrauma—From Injury to Repair: Clinical Perspectives, Cellular Mechanisms and Promoting Regeneration of the Injured Brain and Spinal Cord

“…Astrocyte activation and the ensuing astrogliosis are not observed. Some mechanisms, such as activation of apopotic pathways and oxidative stress, are also common to zebrafish [ 126 ]. Owing to the vastly differing cellular populations, genetic differences and differing neuronal responses, such work carries inherent limitations.…”

REDOX Balance in Oligodendrocytes Is Important for Zebrafish Visual System Regeneration

“…The role of ROS during regeneration has been shown in several scenarios [20,22]. To understand whether they are also involved during zebrafish visual system regeneration, we used the ON crush model [32].…”

“…In zebrafish, ROS are produced after tail injury and promote its regeneration [20] and the presence of antioxidants can be detrimental to an efficient regeneration [21]. CNS is no exception to the production of ROS after injury, but its impact is less well understood [22]. For example, in some contexts, such as demyelinating neurological diseases, excessive ROS are detrimental [23].…”