Direkt zum Inhalt

Eisinger, Kristina ; Girke, Philipp ; Buechler, Christa ; Krautbauer, Sabrina

Adipose tissue depot specific expression and regulation of fibrosis-related genes and proteins in experimental obesity

Eisinger, Kristina, Girke, Philipp, Buechler, Christa and Krautbauer, Sabrina (2023) Adipose tissue depot specific expression and regulation of fibrosis-related genes and proteins in experimental obesity. Mammalian Genome 35, pp. 13-30.

Date of publication of this fulltext: 31 Oct 2023 05:21
Article
DOI to cite this document: 10.5283/epub.54936


Abstract

Transforming growth factor beta (Tgfb) is a well-studied pro-fibrotic cytokine, which upregulates cellular communication network factor 2 (Ccn2), collagen, and actin alpha 2, smooth muscle (Acta2) expression. Obesity induces adipose tissue fibrosis, which contributes to metabolic diseases. This work aimed to analyze the expression of Tgfb, Ccn2, collagen1a1 (Col1a1), Acta2 and BMP and activin ...

Transforming growth factor beta (Tgfb) is a well-studied pro-fibrotic cytokine, which upregulates cellular communication network factor 2 (Ccn2), collagen, and actin alpha 2, smooth muscle (Acta2) expression. Obesity induces adipose tissue fibrosis, which contributes to metabolic diseases. This work aimed to analyze the expression of Tgfb, Ccn2, collagen1a1 (Col1a1), Acta2 and BMP and activin membrane-bound inhibitor (Bambi), which is a negative regulator of Tgfb signaling, in different adipose tissue depots of mice fed a standard chow, mice fed a high fat diet (HFD) and ob/ob mice. Principally, these genes were low expressed in brown adipose tissues and this difference was less evident for the ob/ob mice. Ccn2 and Bambi protein as well as mRNA expression, and collagen1a1 mRNA were not induced in the adipose tissues upon HFD feeding whereas Tgfb and Acta2 mRNA increased in the white fat depots. Immunoblot analysis showed that Acta2 protein was higher in subcutaneous and perirenal fat of these mice. In the ob/ob mice, Ccn2 mRNA and Ccn2 protein were upregulated in the fat depots. Here, Tgfb, Acta2 and Col1a1 mRNA levels and serum Tgfb protein were increased. Acta2 protein was, however, not higher in subcutaneous and perirenal fat of these mice. Col6a1 mRNA was shown before to be higher in obese fat tissues. Current analysis proved the Col6a1 protein was induced in subcutaneous fat of HFD fed mice. Notably, Col6a1 was reduced in perirenal fat of ob/ob mice in comparison to the respective controls. 3T3-L1 cells express Ccn2 and Bambi protein, whose levels were not changed by fatty acids, leptin, lipopolysaccharide, tumor necrosis factor and interleukin-6. All of these factors led to higher Tgfb in 3T3-L1 adipocyte media but did not increase its mRNA levels. Free fatty acids induced necrosis whereas apoptosis did not occur in any of the in vitro incubations excluding cell death as a main reason for higher Tgfb in cell media. In summary, Tgfb mRNA is consistently induced in white fat tissues in obesity but this is not paralleled by a clear increase of its target genes. Moreover, discrepancies between mRNA and protein expression of Acta2 were observed. Adipocytes seemingly do not contribute to higher Tgfb mRNA levels in obesity. These cells release more Tgfb protein when challenged with obesity-related metabolites connecting metabolic dysfunction and fibrosis.



Involved Institutions


Details

Item typeArticle
Journal or Publication TitleMammalian Genome
Publisher:SPRINGER
Place of Publication:NEW YORK
Volume:35
Page Range:pp. 13-30
Date26 October 2023
InstitutionsMedicine > Lehrstuhl für Innere Medizin I
Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Cell Cycle Control > Prof. Dr. Wolfgang Seufert
Identification Number
ValueType
10.1007/s00335-023-10022-3DOI
KeywordsBOUND INHIBITOR BAMBI; TGF-BETA; INSULIN-RESISTANCE; LEPTIN; CELLS; WHITE; LIPOPOLYSACCHARIDE; ADIPOGENESIS; INFLAMMATION; ACTIVATION; Bambi; Actin alpha 2 smooth muscle; Collagen; White fat; Brown fat; Lipopolysaccharide
Dewey Decimal Classification500 Science > 570 Life sciences
600 Technology > 610 Medical sciences Medicine
StatusPublished
RefereedYes, this version has been refereed
Created at the University of RegensburgYes
URN of the UB Regensburgurn:nbn:de:bvb:355-epub-549367
Item ID54936

Export bibliographical data

Owner only: item control page

nach oben