MYCT1 controls environmental sensing in human haematopoietic stem cells

Júlia Aguadé-Gorgorió; Yasaman Jami-Alahmadi; Vincenzo Calvanese; Maya Kardouh; Iman Fares; Haley Johnson; Valerie Rezek; Feiyang Ma; Mattias Magnusson; Yanling Wang; Juliana E Shin; Karina J Nance; Helen S Goodridge; Simone Liebscher; Katja Schenke-Layland; Gay M Crooks; James A Wohlschlegel; Hanna K A Mikkola

doi:10.1038/s41586-024-07478-x

MYCT1 controls environmental sensing in human haematopoietic stem cells

Nature. 2024 Jun;630(8016):412-420. doi: 10.1038/s41586-024-07478-x. Epub 2024 Jun 5.

Authors

Júlia Aguadé-Gorgorió^{1

2}, Yasaman Jami-Alahmadi^{3

4}, Vincenzo Calvanese^{5

6

7

8}, Maya Kardouh^{5

9}, Iman Fares^{5

10}, Haley Johnson^{5

11}, Valerie Rezek^{6

12

13}, Feiyang Ma^{5

14

15}, Mattias Magnusson^{5

6

16}, Yanling Wang⁵, Juliana E Shin^{17

12}, Karina J Nance¹⁷, Helen S Goodridge^{12

17}, Simone Liebscher¹⁸, Katja Schenke-Layland^{18

19}, Gay M Crooks^{6

20

21}, James A Wohlschlegel³, Hanna K A Mikkola^{22

23

24

25}

Affiliations

¹ Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA. julia.aguade@gmail.com.
² Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, CA, USA. julia.aguade@gmail.com.
³ Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA, USA.
⁴ Pfizer, Cambridge, MA, USA.
⁵ Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA.
⁶ Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, CA, USA.
⁷ Laboratory for Molecular Cell Biology, University College London, London, UK.
⁸ Josep Carreras Leukaemia Research Institute, Barcelona, Spain.
⁹ Oakland University William Beaumont School of Medicine, Rochester, MI, USA.
¹⁰ Kite Pharma, Santa Monica, CA, USA.
¹¹ Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA.
¹² David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
¹³ UCLA AIDS Institute, University of California Los Angeles, Los Angeles, CA, USA.
¹⁴ Institute for Genomics and Proteomics, University of California Los Angeles, Los Angeles, CA, USA.
¹⁵ Amgen, Thousand Oaks, CA, USA.
¹⁶ Division of Molecular Medicine and Gene Therapy, Lund Stem Cell Center, Lund University, Lund, Sweden.
¹⁷ Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
¹⁸ Institute of Biomedical Engineering, Department for Medical Technologies and Regenerative Medicine, Eberhard Karls University, Tübingen, Germany.
¹⁹ NMI Natural and Medical Sciences Institute at the University Tübingen, Reutlingen, Germany.
²⁰ Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA.
²¹ Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
²² Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA. hmikkola@mcdb.ucla.edu.
²³ Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, CA, USA. hmikkola@mcdb.ucla.edu.
²⁴ Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA. hmikkola@mcdb.ucla.edu.
²⁵ Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA. hmikkola@mcdb.ucla.edu.

Abstract

The processes that govern human haematopoietic stem cell (HSC) self-renewal and engraftment are poorly understood and challenging to recapitulate in culture to reliably expand functional HSCs^1-3. Here we identify MYC target 1 (MYCT1; also known as MTLC) as a crucial human HSC regulator that moderates endocytosis and environmental sensing in HSCs. MYCT1 is selectively expressed in undifferentiated human haematopoietic stem and progenitor cells (HSPCs) and endothelial cells but becomes markedly downregulated during HSC culture. Lentivirus-mediated knockdown of MYCT1 prevented human fetal liver and cord blood (CB) HSPC expansion and engraftment. By contrast, restoring MYCT1 expression improved the expansion and engraftment of cultured CB HSPCs. Single-cell RNA sequencing of human CB HSPCs in which MYCT1 was knocked down or overexpressed revealed that MYCT1 governs important regulatory programmes and cellular properties essential for HSC stemness, such as ETS factor expression and low mitochondrial activity. MYCT1 is localized in the endosomal membrane in HSPCs and interacts with vesicle trafficking regulators and signalling machinery. MYCT1 loss in HSPCs led to excessive endocytosis and hyperactive signalling responses, whereas restoring MYCT1 expression balanced culture-induced endocytosis and dysregulated signalling. Moreover, sorting cultured CB HSPCs on the basis of lowest endocytosis rate identified HSPCs with preserved MYCT1 expression and MYCT1-regulated HSC stemness programmes. Our work identifies MYCT1-moderated endocytosis and environmental sensing as essential regulatory mechanisms required to preserve human HSC stemness. Our data also pinpoint silencing of MYCT1 as a cell-culture-induced vulnerability that compromises human HSC expansion.

MeSH terms

Animals
Cell Self Renewal*
Cells, Cultured
Endocytosis
Endosomes / metabolism
Endothelial Cells / cytology
Endothelial Cells / metabolism
Female
Fetal Blood / cytology
Gene Knockdown Techniques
Hematopoietic Stem Cells* / cytology
Hematopoietic Stem Cells* / metabolism
Humans
Liver / cytology
Liver / embryology
Liver / metabolism
Male
Mice
Mitochondria / metabolism
Nuclear Proteins* / metabolism
Proto-Oncogene Proteins c-ets / genetics
Proto-Oncogene Proteins c-ets / metabolism
Signal Transduction
Single-Cell Gene Expression Analysis

Substances

MYCT1 protein, human
Nuclear Proteins
Proto-Oncogene Proteins c-ets

Abstract

MeSH terms

Substances

Grants and funding