Neutral amino acid transporter SLC38A2 protects renal medulla from hyperosmolarity-induced ferroptosis

Abstract

Hyperosmolarity of the renal medulla is essential for urine concentration and water homeostasis. However, how renal medullary collecting duct (MCD) cells survive and function under harsh hyperosmotic stress remains unclear. Using RNA-Seq, we identified SLC38A2 as a novel osmoresponsive neutral amino acid transporter in MCD cells. Hyperosmotic stress-induced cell death in MCD cells occurred mainly via ferroptosis, and it was significantly attenuated by SLC38A2 overexpression but worsened by Slc38a2-gene deletion or silencing. Mechanistic studies revealed that the osmoprotective effect of SLC38A2 is dependent on the activation of mTORC1. Moreover, an in vivo study demonstrated that Slc38a2-knockout mice exhibited significantly increased medullary ferroptosis following water restriction. Collectively, these findings reveal that Slc38a2 is an important osmoresponsive gene in the renal medulla and provide novel insights into the critical role of SLC38A2 in protecting MCD cells from hyperosmolarity-induced ferroptosis via the mTORC1 signalling pathway.

Data availability

Sequencing data have been deposited in GEO under accession codes GSE206476.All data analysed during this study are included in the manuscript and supporting file; Source Data files have been provided for Figures 1-10 and Figures S1-11.Figure 1 - Source Data 1 and Figure 2 - Source Data 1 contain the numerical data used to generate the figures.

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. Chunxiu Du

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    For correspondence
    chunxiu_du@163.com
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4152-4663
  2. Hu Xu

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1198-0932
  3. Cong Cao

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Jiahui Cao

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  5. Yufei Zhang

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  6. Cong Zhang

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  7. Rongfang Qiao

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  8. Wenhua Ming

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  9. Yaqing Li

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  10. Huiwen Ren

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6037-8561
  11. Xiaohui Cui

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  12. Zhilin Luan

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    Competing interests
    The authors declare that no competing interests exist.
  13. Youfei Guan

    Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
    For correspondence
    youfeiguan@163.com
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5231-0209
  14. Xiaoyan Zhang

    Health Science Center, East China Normal University, Shanghai, China
    For correspondence
    xyzhang@hsc.ecnu.edu.cn
    Competing interests
    The authors declare that no competing interests exist.

Funding

National Natural Science Foundation of China (82270703)

  • Xiaoyan Zhang

National Natural Science Foundation of China (81970606)

  • Xiaoyan Zhang

National Natural Science Foundation of China (81970595)

  • Youfei Guan

National Key Research and Development Program of China (2020YFC2005000)

  • Youfei Guan

East China Normal University (2022JKXYD03001)

  • Xiaoyan Zhang

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: The use of animals and the study protocols were reviewed and approved by the Animal Care and Use Review Committee of Dalian Medical University and the study conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health (in Guide for the Care and Use of Laboratory Animals, th, Editor. 2011: Washington )

Copyright

© 2023, Du et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,708
    views
  • 315
    downloads
  • 9
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Chunxiu Du
  2. Hu Xu
  3. Cong Cao
  4. Jiahui Cao
  5. Yufei Zhang
  6. Cong Zhang
  7. Rongfang Qiao
  8. Wenhua Ming
  9. Yaqing Li
  10. Huiwen Ren
  11. Xiaohui Cui
  12. Zhilin Luan
  13. Youfei Guan
  14. Xiaoyan Zhang
(2023)
Neutral amino acid transporter SLC38A2 protects renal medulla from hyperosmolarity-induced ferroptosis
eLife 12:e80647.
https://doi.org/10.7554/eLife.80647

Share this article

https://doi.org/10.7554/eLife.80647

Further reading

    1. Cell Biology
    Weihong Xiong, Maozhen Qin, Haining Zhong
    Short Report

    Protein kinase A (PKA) plays essential roles in diverse cellular functions. However, the spatiotemporal dynamics of endogenous PKA upon activation remain debated. The classical model predicts that PKA catalytic subunits dissociate from regulatory subunits in the presence of cAMP, whereas a second model proposes that catalytic subunits remain associated with regulatory subunits following physiological activation. Here, we report that different PKA subtypes, as defined by the regulatory subunit, exhibit distinct subcellular localization at rest in CA1 neurons of cultured hippocampal slices. Nevertheless, when all tested PKA subtypes are activated by norepinephrine, presumably via the β-adrenergic receptor, catalytic subunits translocate to dendritic spines but regulatory subunits remain unmoved. These differential spatial dynamics between the subunits indicate that at least a significant fraction of PKA dissociates. Furthermore, PKA-dependent regulation of synaptic plasticity and transmission can be supported only by wildtype, dissociable PKA, but not by inseparable PKA. These results indicate that endogenous PKA regulatory and catalytic subunits dissociate to achieve PKA function in neurons.

    1. Cell Biology
    Jeongsik Kim, Dahyun Kim ... Dae-Sik Lim
    Research Article

    Cell survival in metazoans depends on cell attachment to the extracellular matrix (ECM) or to neighboring cells. Loss of such attachment triggers a type of programmed cell death known as anoikis, the acquisition of resistance to which is a key step in cancer development. The mechanisms underlying anoikis resistance remain unclear, however. The intracellular F-actin cytoskeleton plays a key role in sensing the loss of cell–ECM attachment, but how its disruption affects cell fate during such stress is not well understood. Here, we reveal a cell survival strategy characterized by the formation of a giant unilocular vacuole (GUVac) in the cytoplasm of the cells whose actin cytoskeleton is disrupted during loss of matrix attachment. Time-lapse imaging and electron microscopy showed that large vacuoles with a diameter of >500 nm accumulated early after inhibition of actin polymerization in cells in suspension culture, and that these vacuoles subsequently coalesced to form a GUVac. GUVac formation was found to result from a variation of a macropinocytosis-like process, characterized by the presence of inwardly curved membrane invaginations. This phenomenon relies on both F-actin depolymerization and the recruitment of septin proteins for micron-sized plasma membrane invagination. The vacuole fusion step during GUVac formation requires PI(3)P produced by VPS34 and PI3K-C2α on the surface of vacuoles. Furthermore, its induction after loss of matrix attachment conferred anoikis resistance. Our results thus show that the formation of a previously unrecognized organelle promotes cell survival in the face of altered actin and matrix environments.