Analyzing signaling activity and function in hematopoietic cells

Abstract

Cells constantly sense their environment, allowing the adaption of cell behavior to changing needs. Fine-tuned responses to complex inputs are computed by signaling pathways, which are wired in complex connected networks. Their activity is highly context-dependent, dynamic, and heterogeneous even between closely related individual cells. Despite lots of progress, our understanding of the precise implementation, relevance, and possible manipulation of cellular signaling in health and disease therefore remains limited. Here, we discuss the requirements, potential, and limitations of the different current technologies for the analysis of hematopoietic stem and progenitor cell signaling and its effect on cell fates.

Combining single-cell tracking and omics improves blood stem cell fate regulator identification

“…One example is signaling activity dynamics, which regulate cell fates and require continuous live single-cell tracking for their quantification. 58 Heterogeneous signaling activity dynamics exist in hematopoietic stem and progenitor cells. 59 We have already used trackSeq to identify signaling dynamics-specific hematopoietic stem and progenitor cell gene target programs, in this case only using dynamics history but no kinship or fate directionality information.…”

Single Living Cell Analysis Decodes Dynamical Signaling Patterns Triggering Different Phenotypes of Cell Migration

“…Continuous cell tracking and quantifying cellular and molecular dynamics can transform static cell properties into cellular and molecular dynamics. , Thus, continuous analysis of single cells over prolonged time scales (hours) is crucial in deciphering dynamic and heterogeneous cell responses, but this is a general problem that needs to be overcome by single-cell migration analysis techniques. Fluorescence time-lapse imaging is the most used technique for imaging signaling components in single cells. , Fluorescence-based live-cell analysis requires fluorescence labeling, mainly relying on fluorescent proteins and live-cell fluorescence imaging. However, the fluorescent protein labels may affect the native function of target proteins.…”

Embryonic stem cell ERK, AKT, plus STAT3 response dynamics combinatorics are heterogeneous but NANOG state independent

“…Signaling thus is at the apex of their fate control, and its effects are mediated through downstream effectors including transcription factors and their networks ( Filipczyk et al., 2015 ; Ng and Surani, 2011 ; Schulz et al., 2014 ). Signaling activity is heterogeneous between individual cells even upon identical stimulation of seemingly homogeneous populations ( Kull and Schroeder, 2021 ; Singh et al., 2010 ). In addition, signaling pathways can not only be switched on or off in a binary fashion but can display different activity patterns over time (i.e., dynamics).…”

“…In human hematopoietic stem cells, different ERK signaling dynamics correlate with different future fates ( Wang et al., 2021 ), and oscillatory NFKB dynamics bias granulocyte-monocyte progenitors to the monocyte lineage ( Kull et al., 2022 ). Signaling activity dynamics can only be recognized by continuous single-cell quantification ( Endele and Schroeder, 2012 ; Etzrodt et al., 2014 ; Hoppe et al., 2014 ; Kull and Schroeder, 2021 ; Schroeder, 2005 ). Given the crosstalk between different signaling pathways, they should be analyzed simultaneously.…”