Mitochondria and anesthetic-induced developmental neurotoxicity

PROJECT SUMMARY Millions of children receive general anesthetics (GAs) for surgical procedures. Emerging evidence from human epidemiologic and animal studies suggest that short acting general anesthetic drugs can cause acute brain injury, leading to long-term cognitive defects and behavioral problems. In 2016, the US Food and Drug Administration issued a warning about the potential neurotoxic effects of GA exposure in children under age three. As GA use is necessary for many surgeries, avoidance is often impossible. Thus, understanding how anesthetics induce neurotoxicity is of critical importance in public health, especially so that effective neuroprotective strategies can be developed. One promising area of investigation is mitochondria -- as neurons have high energy requirements, they are especially vulnerable to injury and death from dysfunctional mitochondria. However, despite the extensive research of anesthetic-induced developmental neurotoxicity (AIDN) done during the last decades, mechanisms by which mitochondrial impairment leads to neuronal signaling deregulation and cell death remain unclear. Causative relationship between mitochondrial injury and anesthetic-induced long-term behavioral abnormalities has not been explored. To address the aforementioned gap, in our preliminary studies we investigated and found that anesthetics were toxic to mitochondria in developing mouse and human brain cells. Our data also suggest the regulative function of dysregulated non- coding RNAs in anesthetic-induced impaired mitochondrial function. Thus, the overarching goal of this program is to continue to fill the gap of mitochondrial knowledge in anesthetic nontoxicity by investigating the functions and novel regulatory molecular mechanisms of mitochondria in AIDN as well as developing neuroprotective approaches targeting mitochondria. Extending upon our lab's recent research and preliminary findings, our proposed program will focus on the following three independent research areas: 1) Determine functions and brain cell type-specific mechanisms of mitochondrial signaling in anesthetic-induced cognitive dysfunction and abnormal behaviors. 2) Delineate novel posttranscriptional regulation mechanisms by which mitochondrial signaling and functions are regulated in AIDN. 3) Investigate neuroprotective effect of small molecules in AIDN. We will conduct these investigations using both transgenic mouse models and similar human induced pluripotent stem cell models obtained via CRISPR-Cas9 gene editing. Furthermore, this program will use innovative, cutting-edge experimental neuroscience tools, unbiased multi-omic approaches (e.g., gene gain- and loss-of function, multiphoton real time imaging, single-cell RNA sequencing, and high-throughput analysis of neuronal activities). The proposed studies will facilitate a better understanding of GA-driven mitochondrial dysfunction, which may lead to effective therapeutics for preventing AIDN in young children.