Unveiling the contribution of the reproductive system of individual Caenorhabditis elegans on oxygen consumption by single-point scanning electrochemical microscopy measurements

Author(s)

Santos, Carla S. ^{[1, 2]} ; Macedo, Felipe ^[3] ; Kowaltowski, Alicia J. ^[4] ; Bertotti, Mauro ^[1] ; Unwin, Patrick R. ^{[5, 6]} ; da Cunha, Fernanda Marques ^[3] ; Meloni, Gabriel N. ^{[5, 6]}

Affiliation

^[1] Dept Quim Fundamental, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Ruhr Univ Bochum, Analyt Chem Ctr Electrochem Sci CES, Fac Chem & Biochem, Univ Str 150, D-44780 Bochum - Germany

^[3] Univ Fed Sao Paulo, Escola Paulista Med, Dept Bioquim, Rua Tres Maio 100, BR-04044020 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Quim, Dept Bioquim, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[5] Univ Warwick, Dept Chem, Coventry CV4 7AL, W Midlands - England

^[6] Univ Warwick, Bioelect Engn Innovat Hub, Coventry CV4 7AL, W Midlands - England

• Document type: Journal article
• Source: Analytica Chimica Acta; v. 1146, p. 88-97, FEB 15 2021.
• Web of Science Citations: 1

Abstract

Metabolic analysis in animals is usually either evaluated as whole-body measurements or in isolated tissue samples. To reveal tissue specificities in vivo, this study uses scanning electrochemical microscopy (SECM) to provide localized oxygen consumption rates (OCRs) in different regions of single adult Caenorhabditis elegans individuals. This is achieved by measuring the oxygen reduction current at the SECM tip electrode and using a finite element method model of the experiment that defines oxygen concentration and flux at the surface of the organism. SECM mapping measurements uncover a marked heterogeneity of OCR along the worm, with high respiration rates at the reproductive system region. To enable sensitive and quantitative measurements, a self-referencing approach is adopted, whereby the oxygen reduction current at the SECM tip is measured at a selected point on the worm and in bulk solution (calibration). Using genetic and pharmacological approaches, our SECM measurements indicate that viable eggs in the reproductive system are the main contributors in the total oxygen consumption of adult Caenorhabditis elegans. The finding that large regional differences in OCR exist within the animal provides a new understanding of oxygen consumption and metabolic measurements, paving the way for tissue-specific metabolic analyses and toxicity evaluation within single organisms. (C) 2020 The Author(s). Published by Elsevier B.V. (AU)

• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/22396-6 - Development of a microsensor coupled to scanning electrochemical microscopy to investigate the role of mitochondria on the respiration process
• Grantee: Carla Santana Santos
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/08782-1 - Miniaturized and integrated chemical sensors: new fabrication platforms for biological, clinical and environmental applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants