Unified Probability Distribution and Dynamics of Lead Contents in Human Erythrocytes Revealed by Single-Cell Analysis

Understanding
the presence and dynamics of chemical pollutants
in individual cells is fundamentally important for their trafficking,
fate, and toxicity in humans. The presence of molecular components
(i.e., proteins and mRNA) in individual cells of higher organisms
is considered a stochastic event. The characteristics of chemical
pollutants, as extrinsic compounds, in subpopulation of human cells
on single-cell basis have not been explored yet. Here, we demonstrated
the lead (Pb) content in individual mature erythrocytes (m-erythrocytes)
of Pb-intoxicated patients, and healthy subjects exhibited a unified
pattern in probability distribution (gamma distribution) and dynamics,
despite being highly heterogeneous. The Pb content in individual m-erythrocytes
decreased with the lifetime of m-erythrocytes. Meanwhile, the distribution
and dynamics were found to be highly related to the Pb content in
m-erythrocytes and was independent of patients and their status. This
is the first study to analyze the distribution pattern of chemical
pollutants at a single-cell level in higher organisms. This study
sheds light on the molecular mechanism of Pb trafficking and fate
in humans and the search for an efficient strategy to improve Pb excretion
during Pb treatment.