Correlative light and X-ray tomography jointly unveil the critical role of connexin43 channels on inflammation-induced cellular ultrastructural alterations

DOI: 10.1016/j.heliyon.2024.e27888

Authors: Chidinma A. Okolo (Diamond Light Source) , Jack J. Maran (University of Auckland) , Amy Watts (Diamond Light Source) , Jaime Maripillan (Universidad de Valparaíso) , Maria Harkiolaki (Diamond Light Source) , Agustín D. Martínez (Universidad de Valparaíso) , Colin R. Green (University of Auckland) , Odunayo O. Mugisho (University of Auckland)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Heliyon , VOL 105

State: Published (Approved)
Published: March 2024
Diamond Proposal Number(s): 30710 , 32140

Abstract: Non-junctional connexin43 (Cx43) plasma membrane hemichannels have been implicated in several inflammatory diseases, particularly playing a role in ATP release that triggers activation of the inflammasome. Therapies targeting the blocking of the hemichannels to prevent the pathological release or uptake of ions and signalling molecules through its pores are of therapeutic interest. To date, there is no close-to-native, high-definition documentation of the impact of Cx43 hemichannel-mediated inflammation on cellular ultrastructure, neither is there a robust account of the ultrastructural changes that occur following treatment with selective Cx43 hemichannel blockers such as Xentry-Gap19 (XG19). A combination of same-sample correlative high-resolution three-dimensional fluorescence microscopy and soft X-ray tomography at cryogenic temperatures, enabled in the identification of novel 3D molecular interactions within the cellular milieu when comparing behaviour in healthy states and during the early onset or late stages under inflammatory conditions. Notably, our findings suggest that XG19 blockage of connexin hemichannels under pro-inflammatory conditions may be crucial in preventing the direct degradation of connexosomes by lysosomes, without affecting connexin protein translation and trafficking. We also delineated fine and gross cellular phenotypes, characteristic of inflammatory insult or road-to-recovery from inflammation, where XG19 could indirectly prevent and reverse inflammatory cytokine-induced mitochondrial swelling and cellular hypertrophy through its action on Cx43 hemichannels. Our findings suggest that XG19 might have prophylactic and therapeutic effects on the inflammatory response, in line with functional studies.

Journal Keywords: Connexin43; Hemichannels; Inflammasome; Inflammation; Correlative imaging; Structured illumination microscopy; Soft X-ray tomography; Correlative light and X-ray tomography

Subject Areas: Biology and Bio-materials, Medicine


Instruments: B24-Cryo Soft X-ray Tomography

Added On: 22/03/2024 20:03

Documents:
PIIS2405844024039197.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Imaging Tomography Cryo-soft X-ray Tomography (Cryo-SXT)