Skip to main content
Log in

Crosstalk between adenine nucleotide transporter and mitochondrial swelling: experimental and computational approaches

  • Original Article
  • Published:
Cell Biology and Toxicology Aims and scope Submit manuscript

Abstract

Mitochondrial metabolism and function are modulated by changes in matrix Ca2+. Small increases in the matrix Ca2+ stimulate mitochondrial bioenergetics, whereas excessive Ca2+ leads to cell death by causing massive matrix swelling and impairing the structural and functional integrity of mitochondria. Sustained opening of the non-selective mitochondrial permeability transition pores (PTP) is the main mechanism responsible for mitochondrial Ca2+ overload that leads to mitochondrial dysfunction and cell death. Recent studies suggest the existence of two or more types of PTP, and adenine nucleotide translocator (ANT) and FOF1-ATP synthase were proposed to form the PTP independent of each other. Here, we elucidated the role of ANT in PTP opening by applying both experimental and computational approaches. We first developed and corroborated a detailed model of the ANT transport mechanism including the matrix (ANTM), cytosolic (ANTC), and pore (ANTP) states of the transporter. Then, the ANT model was incorporated into a simple, yet effective, empirical model of mitochondrial bioenergetics to ascertain the point when Ca2+ overload initiates PTP opening via an ANT switch-like mechanism activated by matrix Ca2+ and is inhibited by extra-mitochondrial ADP. We found that encoding a heterogeneous Ca2+ response of at least three types of PTPs, weakly, moderately, and strongly sensitive to Ca2+, enabled the model to simulate Ca2+ release dynamics observed after large boluses were administered to a population of energized cardiac mitochondria. Thus, this study demonstrates the potential role of ANT in PTP gating and proposes a novel mechanism governing the cryptic nature of the PTP phenomenon.

Graphical abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

Data availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. Modeling codes are available in Supplementary Information.

Abbreviations

ANT:

Adenine nucleotide translocator

ANTC :

C-state, ANT cytosolic state

ANTM :

M-state, ANT matrix state

ANTP :

P-state, ANT pore state

CRC:

Calcium retention capacity

ETC:

Electron transport chain

IMM:

Inner mitochondrial membrane;

MCU:

Mitochondrial Ca2+ uniporter

OPA1:

Optic atrophy 1

PTP:

Permeability transition pores

PTPm :

Moderately stimulated PTP

PTPs :

Strongly stimulated PTP

PTPw :

Weakly stimulated PTP

ΔΨ m :

Mitochondrial membrane potential

References

Download references

Funding

This study was supported by the National Science Foundation (Award 2006477 to S.J.) and the National Institutes of Health (Grants R25GM061838 and U54MD007600).

Author information

Authors and Affiliations

Authors

Contributions

SJ and JNB conceived and designed the study. XRC-D, JG-B, and JNB performed experiments and interpreted the results. Modeling analysis was performed by XRC-D and JNB. XRC-D and SJ wrote the first draft of the manuscript and all authors commented on the manuscript. SJ supervised the project and is responsible for its integrity. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Sabzali Javadov.

Ethics declarations

Ethics approval

The manuscript does not contain clinical studies or patient data.

Conflict of interest

The authors declare no competing interests.

Additional information

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Headlights

• We developed a detailed biophysical model of ANT kinetics that was verified using ATP/ADP exchange rates for parameter estimation.

• The model was successful in simulating ANT pore state transition and clarified a vital role of ANT in Ca2 + -induced PTP opening.

• The model provided insight into the nature of PTP gating in the presence of respiratory substrates and ADP.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (PDF 900 KB)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chapa-Dubocq, X.R., Garcia-Baez, J.F., Bazil, J.N. et al. Crosstalk between adenine nucleotide transporter and mitochondrial swelling: experimental and computational approaches. Cell Biol Toxicol 39, 435–450 (2023). https://doi.org/10.1007/s10565-022-09724-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10565-022-09724-2

Keywords

Navigation