Sex- and age-related differences in the inflammatory properties of cardiac fibroblasts: impact on the cardiosplenic axis and cardiac fibrosis

Kathleen Pappritz; Sarah-Lena Puhl; Isabel Matz; Erik Brauer; Yi Xuan Shia; Muhammad El-Shafeey; Suzanne E Koch; Kapka Miteva; Christin Mucha; Georg N Duda; Ansgar Petersen; Sabine Steffens; Carsten Tschöpe; Sophie Van Linthout

doi:10.3389/fcvm.2023.1117419

Sex- and age-related differences in the inflammatory properties of cardiac fibroblasts: impact on the cardiosplenic axis and cardiac fibrosis

Front Cardiovasc Med. 2023 Nov 20:10:1117419. doi: 10.3389/fcvm.2023.1117419. eCollection 2023.

Authors

Kathleen Pappritz^{1

2

3}, Sarah-Lena Puhl^{4

5}, Isabel Matz^{1

2

3}, Erik Brauer⁶, Yi Xuan Shia⁵, Muhammad El-Shafeey^{1

2

3

7}, Suzanne E Koch^{2

8}, Kapka Miteva^{2

9}, Christin Mucha², Georg N Duda^{1

2

6}, Ansgar Petersen^{1

2

6}, Sabine Steffens^{5

10}, Carsten Tschöpe^{1

2

3

11

12}, Sophie Van Linthout^{1

2

3}

Affiliations

¹ Berlin Institute of Health at Charité-Universitätsmedizin Berlin, BIH Center for Regenerative Therapies (BCRT), Berlin, Germany.
² Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Campus Virchow Klinikum (CVK), Berlin, Germany.
³ German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany.
⁴ Comprehensive Heart Failure Center, Universitätsklinikum Würzburg, Würzburg, Germany.
⁵ Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany.
⁶ Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany.
⁷ Medical Biotechnology Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications, Alexandria, Egypt.
⁸ Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands.
⁹ Division of Cardiology, Foundation for Medical Research, Department of Medicine Specialized Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
¹⁰ German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance (MHA), Munich, Germany.
¹¹ Department Cardiology, Angiology, and Intensive Medicine (CVK) at the German Heart Center of the Charite (DHZC), Charité-Universitätsmedizin Berlin, Berlin, Germany.
¹² Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland.

Abstract

Background: Age and sex are prominent risk factors for heart failure and determinants of structural and functional changes of the heart. Cardiac fibroblasts (cFB) are beyond their task as extracellular matrix-producing cells further recognized as inflammation-supporting cells. The present study aimed to evaluate the impact of sex and age on the inflammatory potential of cFB and its impact on the cardiosplenic axis and cardiac fibrosis.

Materials: Left ventricles (LV) of 3- and 12-months old male and female C57BL/6J mice were harvested for immunohistochemistry, immunofluorescence and cFB outgrowth culture and the spleen for flow cytometry. LV-derived cFB and respective supernatants were characterized.

Results: LV-derived cFB from 3-months old male mice exhibited a higher inflammatory capacity, as indicated by a higher gene expression of CC-chemokine ligand (CCL) 2, and CCL7 compared to cFB derived from 3-months old female mice. The resulting higher CCL2/chemokine C-X3-C motif ligand (Cx3CL1) and CCL7/Cx3CL1 protein ratio in cell culture supernatants of 3-months old male vs. female cFB was reflected by a higher migration of Ly6C^high monocytes towards supernatant from 3-months old male vs. female cFB. In vivo a lower ratio of splenic pro-inflammatory Ly6C^high to anti-inflammatory Ly6C^low monocytes was found in 3-months old male vs. female mice, suggesting a higher attraction of Ly6C^high compared to Ly6C^low monocytes towards the heart in male vs. female mice. In agreement, the percentage of pro-inflammatory CD68⁺ CD206^- macrophages was higher in the LV of male vs. female mice at this age, whereas the percentage of anti-inflammatory CD68⁺ CD206⁺ macrophages was higher in the LV of 3-months old female mice compared to age-matched male animals. In parallel, the percentage of splenic TGF-β⁺ cells was higher in both 3- and 12-months old female vs. male mice, as further reflected by the higher pro-fibrotic potential of female vs. male splenocytes at both ages. In addition, female mice displayed a higher total LV collagen content compared to age-matched male mice, whereby collagen content of female cFB was higher compared to male cFB at the age of 12-months.

Conclusion: Age- and sex-dependent differences in cardiac fibrosis and inflammation are related to age- and sex-dependent variations in the inflammatory properties of cardiac fibroblasts.

Keywords: aging; cardiac fibroblasts; cardiosplenic axis; fibrosis; monocytes; sex.

Grants and funding

This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—SFB-1470 to C.T. (SFB-1470-B02), and S.V.L (SFB-1470-A07), the SFB 1123 and DFG STE 1053/8-1 to S.S., and the CRC1444 to E.B., G.N.D., and A.P (427826188-SFB/CRC1444). S.S. was further supported by the German Ministry of Research and Education (DZHK FKZ 81Z0600205). Open Access funding was enabled and organized by Projekt DEAL.