TY - JOUR

T1 - The CaMKIIα hub ligand Ph-HTBA promotes neuroprotection after focal ischemic stroke by a distinct molecular interaction

AU - Griem-Krey, Nane

AU - Gauger, Stine J.

AU - Gowing, Emma K.

AU - Thiesen, Louise

AU - Frølund, Bente

AU - Clarkson, Andrew N.

AU - Wellendorph, Petrine

N1 - Funding Information: We would like to thank Dr. Geeske van Woerden for valuable input, and we appreciate fruitful discussions with Dr. Sara M. Solbak and chemistry assistance for the synthesis of Ph-HTBA from Dr. Yongsong Tian. This work was supported by the Lundbeck Foundation (grant R277-2018-260 ), the Novo Nordisk Foundation (grant NNF17OC0028664 ) and the Drug Research Academy .

PY - 2022

Y1 - 2022

N2 - Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIα) is a potential target for acute neuroprotection due to its key role in physiological and pathological glutamate signaling. The hub domain organizes the CaMKII holoenzyme into large oligomers, and additional functional effects on holoenzyme activation have lately emerged. We recently reported that compounds related to the proposed neuromodulator γ-hydroxybutyrate (GHB) selectively bind to the CaMKIIα hub domain and increase hub thermal stabilization, which is believed to have functional consequences and to mediate neuroprotection. However, the detailed molecular mechanism is unknown. In this study, we functionally characterize the novel and brain permeable GHB analog (E)-2-(5-hydroxy-2-phenyl-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-ylidene)acetic acid (Ph-HTBA). Administration of a single dose of Ph-HTBA at a clinically relevant time point (3–6 h after photothrombotic stroke) promotes neuroprotection with a superior effect at low doses compared to the smaller GHB analog 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA). In contrast to HOCPCA, Ph-HTBA reduces Ca2+-stimulated CaMKIIα Thr286 autophosphorylation in primary cortical neurons and substrate phosphorylation of recombinant CaMKIIα, potentially contributing to its neuroprotective effect. Supported by previous in silico docking studies, we suggest that Ph-HTBA makes distinct molecular interactions with the hub cavity, which may contribute to its differential functional profile and superior neuroprotective effect compared to HOCPCA. Together, this highlights Ph-HTBA as a promising tool to study hub functionality, but also as a good candidate for clinical development.

AB - Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIα) is a potential target for acute neuroprotection due to its key role in physiological and pathological glutamate signaling. The hub domain organizes the CaMKII holoenzyme into large oligomers, and additional functional effects on holoenzyme activation have lately emerged. We recently reported that compounds related to the proposed neuromodulator γ-hydroxybutyrate (GHB) selectively bind to the CaMKIIα hub domain and increase hub thermal stabilization, which is believed to have functional consequences and to mediate neuroprotection. However, the detailed molecular mechanism is unknown. In this study, we functionally characterize the novel and brain permeable GHB analog (E)-2-(5-hydroxy-2-phenyl-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-ylidene)acetic acid (Ph-HTBA). Administration of a single dose of Ph-HTBA at a clinically relevant time point (3–6 h after photothrombotic stroke) promotes neuroprotection with a superior effect at low doses compared to the smaller GHB analog 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA). In contrast to HOCPCA, Ph-HTBA reduces Ca2+-stimulated CaMKIIα Thr286 autophosphorylation in primary cortical neurons and substrate phosphorylation of recombinant CaMKIIα, potentially contributing to its neuroprotective effect. Supported by previous in silico docking studies, we suggest that Ph-HTBA makes distinct molecular interactions with the hub cavity, which may contribute to its differential functional profile and superior neuroprotective effect compared to HOCPCA. Together, this highlights Ph-HTBA as a promising tool to study hub functionality, but also as a good candidate for clinical development.

KW - Autophosphorylation

KW - Baclofen (PubChem CID: 44602), KN93 (PubChem CID: 5312122)

KW - CaMKII

KW - GHB (PubChem CID: 23663870)

KW - HOCPCA (PubChem CID: 21750168)

KW - Hub domain

KW - Motor behavior

KW - Photothrombotic stroke

U2 - 10.1016/j.biopha.2022.113895

DO - 10.1016/j.biopha.2022.113895

M3 - Journal article

C2 - 36274464

AN - SCOPUS:85140091176

VL - 156

JO - Biomedicine and Pharmacotherapy

JF - Biomedicine and Pharmacotherapy

SN - 0753-3322

M1 - 113895

ER -