Loss of the serine protease HTRA1 impairs smooth muscle cells maturation

• Published in: Scientific reports Vol. 9; no. 1; pp. 18224 - 10
• Main Authors: Klose, Ralph, Prinz, Alexander, Tetzlaff, Fabian, Weis, Eva-Maria, Moll, Iris, Rodriguez-Vita, Juan, Oka, Chio, Korff, Thomas, Fischer, Andreas
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.12.2019; Nature Publishing Group
• Subjects: 13/89; 14; 14/1; 38; 38/77; 64/60; 692/4017; 692/699/75; 82/80; 96/106; 96/63; 96/95; Animals; Blotting, Western; Dementia disorders; Fluorescent Antibody Technique; Genotype & phenotype; High-Temperature Requirement A Serine Peptidase 1 - metabolism; High-Temperature Requirement A Serine Peptidase 1 - physiology; Homeostasis; Humanities and Social Sciences; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; multidisciplinary; Muscle Contraction; Muscle, Smooth, Vascular - growth & development; Muscle, Smooth, Vascular - metabolism; Phenotypes; Real-Time Polymerase Chain Reaction; Receptor, Notch3 - metabolism; Receptor, Notch3 - physiology; Repressors; Science; Science (multidisciplinary); Serine; Serine proteinase; Signal Transduction; Smad2 protein; Smooth muscle; Transcription factors; Transforming Growth Factor beta - metabolism; Transforming Growth Factor beta - physiology; Vasoconstriction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-54807-6

Vascular smooth muscle cell (VSMC) dysfunction is a hallmark of small vessel disease, a common cause of stroke and dementia. Two of the most frequently mutated genes in familial small vessel disease are HTRA1 and NOTCH3 . The protease HTRA1 cleaves the NOTCH3 ligand JAG1 implying a mechanistic link between HTRA1 and Notch signaling. Here we report that HTRA1 is essential for VSMC differentiation into the contractile phenotype. Mechanistically, loss of HTRA1 increased JAG1 protein levels and NOTCH3 signaling activity in VSMC. In addition, the loss of HTRA1 enhanced TGFβ-SMAD2/3 signaling activity. Activation of either NOTCH3 or TGFβ signaling resulted in increased transcription of the HES and HEY transcriptional repressors and promoted the contractile VSMC phenotype. However, their combined over-activation led to an additive accumulation of HES and HEY proteins, which repressed the expression of contractile VSMC marker genes. As a result, VSMC adopted an immature phenotype with impaired arterial vasoconstriction in Htra1-deficient mice. These data demonstrate an essential role of HTRA1 in vascular maturation and homeostasis by controlling Notch and TGFβ signaling.