fairfolio
Saved Projects

Different Caspases Mediate Age-Related Apoptosis in Neurons Compared with Astrocytes

CSEF · 2003 Biochemistry/ Molecular Biology

Yibo Yang · Palo Alto High School, Palo Alto

Overview

Objectives/Goals Apoptosis is a cell suicide program; however, effects of age and cell type on apoptosis in the brain are poorly understood. The age at which different brain cells are most susceptible to apoptosis is unclear. Methods/Materials Neuron and astrocyte cultures were deprived of serum. To characterize DNA fragmentation, Terminal deoxynucleotidyl transferase-mediated dUTP labeling (TUNEL) staining was performed. To identify apoptotic or necrotic cells in cultured cell population, Hoechst and Propidium Iodide (PI) staining were performed. Cell injury was quantified through lactate dehydrogenase (LDH) assay. Caspase and MAP kinase phosphorylation were measured using immuno-blotting. Caspase 3, 8 and 9 were also inhibited in both cultures to determine its role in determining age-related differences. All data were analyzed by one-way analysis of variance (ANOVA), followed by two-tailed Student's t-test. Results Young neurons showed more apoptosis and greater caspase (essential protease for apoptosis) expressions compared to mature neurons. Mature neurons and astrocytes were found to be less vulnerable to serum deprivation and to undergo necrosis rather than apoptosis, which correlates with a lack of caspase activity and TUNEL-positive cells. Astrocytes showed condensed but non-fragmented nuclei and a different caspase expression. Conclusions/Discussion Caspase 3, 8, and 9 contribute to neuronal apoptosis while caspase 11 seems important to astrocytes. Our findings suggest that neurons and astrocytes utilize different apoptotic pathways as they develop and anti-apoptotic interventions against brain injury should be developmentally targeted and specific to cell type

Summary statement

Caspases differentiate neurons and astrocytes; they contribute to the different apoptotic pathways.

Help received

This study was supported by grants (NIH GM49831) to Dr. R.G. Giffard at the Department of Anesthesia, Stanford University School of Medicine. I wholeheartedly thank Drs. Giffard, Xu, and Chock for help on the supervision for all methodology, discussions of the experiment designs and results, and critical

Awards (1)

  • Category Award

Competition history

  • CSEF 2003 Biochemistry/ Molecular Biology · Entry S0423

Resources

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

Source: California Science & Engineering Fair public projects

Save projects to your library

Sign in with Google to keep track of projects you find interesting, organized into folders. An account also raises your daily allowance for “Has this been done?”, and lets you create a key for the MCP server with a much higher limit than anonymous use. Browsing stays public.

Continue with Google