Abstract 1374 The heart failure-induced long non-coding RNA Heat4 increases the amount of CD16+ monocytes and promotes vascular regeneration

Background and Purpose: Activation of the immune system correlates with the severity and the prognosis of patients with heart failure (HF). Here, we aim to identify and characterize long non-coding RNAs (lncRNAs) as a potential mechanistic link between the activation of the immune system and the pathophysiology of HF.

Methods and Results: Using next-generation sequencing we identified the lncRNA Heat4 which is significantly upregulated in patients with ischemic cardiomyopathy compared to controls (+2.05-fold-increase; N=4; p<0.05). Heat4 is located in the cytoplasm of non-classical monocytes where it is stabilized by its poly-A-tail (+5.30-fold-enrichment in poly(A+)-fraction; p<0.05). Single-cell sequencing of PBMCs of HF patients and controls revealed a higher percentage of monocytes and a reduced percentage of T cells in HF patients compared to controls (Monocyte/ T Cell Ratio: Control: 0.68 (N=3); HF: 1.93 (N=8); p<0.05). The increased Heat4 expression in the HF patients was not only a consequence of having more monocytes but a combination of more monocytes with a higher Heat4 expression.

Interestingly, a single cell sequencing analysis of monocytes after overexpression of Heat4 resulted in an increase of intermediate and non-classical monocytes, as determined by increased expression of CD16 in monocytes compared to transfection with the control-plasmid (pcDNA: 58.08% classical, 30.03% intermediate, 3.40% non-classical monocytes; Heat4 overexpression: 35.51% classical, 51.32% intermediate, 4.09% non-classical monocytes). Matching the known anti-inflammatory properties of non-classical monocytes, Heat4 mediates anti-inflammatory functions in vitro (Heat4 overexpression: -38.6% TNFα-RNA-reduction; Heat4 knockdown: +4.14-fold TNFα-RNA-enrichment; p<0.05) and promotes vascular regeneration in vivo (carotid arteries of NOD-SCID mice regenerated faster (% regenerated area: +1.85-fold enrichment; N=6; p<0.05) after injection of human monocytes with overexpression of Heat4 compared to injection of control monocytes).

Conclusion: The anti-inflammatory lncRNA Heat4 is elevated in the blood of patients with HF. Heat4 is located in the cytoplasm of non-classical monocytes. Heat4 overexpression results in higher number of intermediate and non-classical monocytes and leads to a faster regeneration after vascular injury in vivo. Therefore, modulating Heat4 levels may represent a novel strategy for the treatment of cardiovascular diseases with impaired vascular functions.

Clin Res Cardiol (2023). https://doi.org/10.1007/s00392-023-02180-w
The heart failure-induced long non-coding RNA Heat4 increases the amount of CD16+ monocytes and promotes vascular regeneration
J. M. Kneuer¹, M. Winkler¹, T. Meinecke¹, M. Möbius-Winkler¹, R. Weiß², J. Haas³, A. Kogel¹, K.-P. Kresoja⁴, S. Rosch⁴, S. Erbe¹, K. E. Kokot¹, P. Stürzebecher¹, T. Garfias-Veitl⁵, S. von Haehling⁵, T. Keller⁶, H. Thiele⁴, P. Lurz⁴, T. Speer⁷, U. Laufs¹, J.-N. Boeckel¹
¹Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Leipzig; ²Institute of Clinical Immunology, University of Leipzig, Leipzig; ³Klinik für Innere Med. III, Kardiologie, Angiologie u. Pneumologie, Universitätsklinikum Heidelberg, Heidelberg; ⁴Klinik für Innere Medizin/Kardiologie, Herzzentrum Leipzig - Universität Leipzig, Leipzig; ⁵Herzzentrum, Klinik für Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen; ⁶Franz-Groedel-Institut (FGI), Justus-Liebig-Universität Giessen, Bad Nauheim; ⁷Medizinische Klinik IV: Nephrologie, Universitätsklinikum Frankfurt, Frankfurt am Main;
Background and Purpose: Activation of the immune system correlates with the severity and the prognosis of patients with heart failure (HF). Here, we aim to identify and characterize long non-coding RNAs (lncRNAs) as a potential mechanistic link between the activation of the immune system and the pathophysiology of HF. Methods and Results: Using next-generation sequencing we identified the lncRNA Heat4 which is significantly upregulated in patients with ischemic cardiomyopathy compared to controls (+2.05-fold-increase; N=4; p<0.05). Heat4 is located in the cytoplasm of non-classical monocytes where it is stabilized by its poly-A-tail (+5.30-fold-enrichment in poly(A+)-fraction; p<0.05). Single-cell sequencing of PBMCs of HF patients and controls revealed a higher percentage of monocytes and a reduced percentage of T cells in HF patients compared to controls (Monocyte/ T Cell Ratio: Control: 0.68 (N=3); HF: 1.93 (N=8); p<0.05). The increased Heat4 expression in the HF patients was not only a consequence of having more monocytes but a combination of more monocytes with a higher Heat4 expression. Interestingly, a single cell sequencing analysis of monocytes after overexpression of Heat4 resulted in an increase of intermediate and non-classical monocytes, as determined by increased expression of CD16 in monocytes compared to transfection with the control-plasmid (pcDNA: 58.08% classical, 30.03% intermediate, 3.40% non-classical monocytes; Heat4 overexpression: 35.51% classical, 51.32% intermediate, 4.09% non-classical monocytes). Matching the known anti-inflammatory properties of non-classical monocytes, Heat4 mediates anti-inflammatory functions in vitro (Heat4 overexpression: -38.6% TNFα-RNA-reduction; Heat4 knockdown: +4.14-fold TNFα-RNA-enrichment; p<0.05) and promotes vascular regeneration in vivo (carotid arteries of NOD-SCID mice regenerated faster (% regenerated area: +1.85-fold enrichment; N=6; p<0.05) after injection of human monocytes with overexpression of Heat4 compared to injection of control monocytes). Conclusion: The anti-inflammatory lncRNA Heat4 is elevated in the blood of patients with HF. Heat4 is located in the cytoplasm of non-classical monocytes. Heat4 overexpression results in higher number of intermediate and non-classical monocytes and leads to a faster regeneration after vascular injury in vivo. Therefore, modulating Heat4 levels may represent a novel strategy for the treatment of cardiovascular diseases with impaired vascular functions.
https://dgk.org/kongress_programme/jt2023/aV458.html