Specialized pericyte subtypes in the pulmonary capillaries

Area of Science:

• Vascular Biology
• Cell Biology
• Pulmonary Hypertension Research

Background:

• Pericytes are vital for capillary stability and homeostasis.
• Impaired pericyte function is linked to diseases such as pulmonary arterial hypertension.
• Identifying specific pericyte markers is challenging, hindering research.

Purpose of the Study:

• To identify a unique gene marker for pericytes.
• To develop tools for accurate pericyte labeling and study.
• To investigate pulmonary pericyte heterogeneity and function in disease.

Main Methods:

• Bioinformatic analysis and RNAscope to identify Higd1b as a pericyte marker.
• Generation of a Higd1b-CreERT2 knock-in mouse line for pericyte labeling.
• Single-cell RNA sequencing to characterize pericyte subtypes.
• In vitro studies on human lung pericytes.

Main Results:

• Higd1b was identified as a unique pericyte gene marker.
• The Higd1b-CreERT2 mouse line enables accurate lung and heart pericyte labeling.
• Two distinct pericyte subtypes were discovered: Type 1 (homeostasis) and Type 2 (arteriolar, vimentin-high, smooth muscle marker-expressing under hypoxia).
• Human lung pericytes with increased vimentin showed enhanced adhesion, migration, and SM22 expression.

Conclusions:

• Higd1b is a novel and specific marker for pulmonary pericytes.
• Pulmonary pericytes exhibit functional specialization.
• Type 2 pericytes may contribute to vascular remodeling in hypoxia-induced pulmonary hypertension.