Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Characterization of Calpain and Caspase-6 Generated Glial Fibrillary Acidic Protein Breakdown Products Following Traumatic Brain Injury and Astroglial Cell Injury

Version 1 : Received: 20 June 2022 / Approved: 22 June 2022 / Online: 22 June 2022 (08:28:02 CEST)

A peer-reviewed article of this Preprint also exists.

Yang, Z.; Arja, R.D.; Zhu, T.; Sarkis, G.A.; Patterson, R.L.; Romo, P.; Rathore, D.S.; Moghieb, A.; Abbatiello, S.; Robertson, C.S.; Haskins, W.E.; Kobeissy, F.; Wang, K.K.W. Characterization of Calpain and Caspase-6-Generated Glial Fibrillary Acidic Protein Breakdown Products Following Traumatic Brain Injury and Astroglial Cell Injury. Int. J. Mol. Sci. 2022, 23, 8960. Yang, Z.; Arja, R.D.; Zhu, T.; Sarkis, G.A.; Patterson, R.L.; Romo, P.; Rathore, D.S.; Moghieb, A.; Abbatiello, S.; Robertson, C.S.; Haskins, W.E.; Kobeissy, F.; Wang, K.K.W. Characterization of Calpain and Caspase-6-Generated Glial Fibrillary Acidic Protein Breakdown Products Following Traumatic Brain Injury and Astroglial Cell Injury. Int. J. Mol. Sci. 2022, 23, 8960.

Journal reference: Int. J. Mol. Sci. 2022, 23, 8960
DOI: 10.3390/ijms23168960

Abstract

Glial fibrillary acidic protein (GFAP) is the major intermediate filament III protein of astroglia cells which is upregulated in traumatic brain injury (TBI). Here we reported that GFAP is truncated at both the C- and N-terminals by cytosolic protease calpain to GFAP breakdown products (GBDP) of 46-40K then 38K following pro-necrotic (A23187) and pro-apoptotic (staurosporine) challenges to primary cultured astroglia or neuron-glia mixed cells. In addition, with another pro-apoptotic challenge (EDTA) where caspases are activated but not calpain, GFAP was fragmented internally, generating a C-terminal GBDP of 20 kDa. Following controlled cortical impact in mice, GBDP of 46-40K and 38K were formed from day 3 to 28 post-injury. Purified GFAP protein treated with calpain-1 and -2 generates (i) major N-terminal cleavage sites between A-56 and A-75, and (ii) major C-terminal cleavage sites between T-383 and Q-388, producing a limit fragment of 38K. Caspase-6 treated GFAP was cleaved at D-78, R-79, D-266 and A-267, where GFAP was relatively resistant to caspase-3. We also derived a GBDP-38K N-terminal-specific antibody which only labels injured astroglia cell body in both cultured astroglia and mouse cortex and hippocampus after TBI. As a clinical translation, we observed that CSF samples collected from severe human TBI have elevated levels of GBDP-38K as well as two C-terminally released GFAP peptides (DGEVIKES and DGEVIKE). Thus, in addition to intact GFAP, both the GBDP-38K as well as unique GFAP released C-terminal proteolytic peptides species might have the potential in tracking brain injury progression.

Keywords

astroglial injury; GFAP; calpain; caspase; biomarkers; traumatic brain injury

Subject

LIFE SCIENCES, Molecular Biology

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.

We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.