Assessing the contribution of thrombospondin-4 induction and ATF6α activation to endoplasmic reticulum expansion and phenotypic modulation in bladder outlet obstruction

Phenotypic modulation of smooth muscle cells is a hallmark of disease. The associated expansion of endoplasmic reticulum (ER) volume remains unexplained. Thrombospondin-4 was recently found to promote ATF6α activation leading to ER expansion. Using bladder outlet obstruction as a paradigm for phenotypic modulation, we tested if thrombospondin-4 is induced in association with ATF6α activation and ER expansion. Thrombospondin-4 was induced and ATF6α was activated after outlet obstruction in rodents. Increased abundance of spliced of Xbp1, another ER-stress sensor, and induction of Atf4 and Creb3l2 was also seen. Downstream of ATF6α, Calr, Manf, Sdf2l1 and Pdi increased as did ER size, whereas contractile markers were reduced. Overexpression of ATF6α, but not of thrombospondin-4, increased Calr, Manf, Sdf2l1 and Pdi and caused ER expansion, but the contractile markers were inert. Knockout of thrombospondin-4 neither affected bladder growth nor expression of ATF6α target genes, and repression of contractile markers was the same, even if ATF6α activation was curtailed. Increases of Xbp1s, Atf4 and Creb3l2 were similar. Our findings demonstrate reciprocal regulation of the unfolded protein response, including ATF6α activation and ER expansion, and reduced contractile differentiation in bladder outlet obstruction occurring independently of thrombospondin-4, which however is a sensitive indicator of obstruction.

Medienart:

E-Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:6

Enthalten in:

Scientific reports - 6(2016) vom: 01. Sept., Seite 32449

Sprache:

Englisch

Beteiligte Personen:

Krawczyk, Katarzyna K [VerfasserIn]
Ekman, Mari [VerfasserIn]
Rippe, Catarina [VerfasserIn]
Grossi, Mario [VerfasserIn]
Nilsson, Bengt-Olof [VerfasserIn]
Albinsson, Sebastian [VerfasserIn]
Uvelius, Bengt [VerfasserIn]
Swärd, Karl [VerfasserIn]

Links:

Volltext

Themen:

145891-90-3
Activating Transcription Factor 4
Activating Transcription Factor 6
Atf4 protein, rat
Atf6 protein, mouse
Basic-Leucine Zipper Transcription Factors
Calb2 protein, rat
Calbindin 2
Creb3l2 protein, mouse
Journal Article
MANF protein, rat
Membrane Proteins
Nerve Growth Factors
Research Support, Non-U.S. Gov't
Sdf2l1 protein, mouse
Thrombospondin 4
Thrombospondins
X-Box Binding Protein 1
Xbp1 protein, rat

Anmerkungen:

Date Completed 16.05.2018

Date Revised 13.11.2018

published: Electronic

Citation Status MEDLINE

doi:

10.1038/srep32449

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM263932761