IL-6 coaxes cellular dedifferentiation as a pro-regenerative intermediate that contributes to pericardial ADSC-induced cardiac repair

Abstract

Background Cellular dedifferentiation is a regenerative prerequisite that warrants cell cycle reentry and appropriate mitotic division during de novo formation of cardiomyocytes. In the light of our previous finding that expression of injury-responsive element, Wilms Tumor factor 1 (WT1), in pericardial adipose stromal cells (ADSC) conferred a compelling reparative activity with concomitant IL-6 upregulation, we then aim to unravel the mechanistic network that governs the process of regenerative dedifferentiation after ADSC-based therapy. Methods and results WT1-expressing ADSC (eGFP:WT1) were irreversibly labeled in transgenic mice (WT1-iCre/Gt(ROSA)26Sor-eGFP) primed with myocardial infarction. EGFP:WT1 cells were enzymatically isolated from the pericardial adipose tissue and cytometrically purified (ADSCgfp+). Bulk RNA-seq revealed upregulation of cardiac-related genes and trophic factors in ADSCgfp+ subset, of which IL-6 was most abundant as compared to non-WT1 ADSC (ADSCgfp−). Injection of ADSCgfp+ subset into the infarcted hearts yielded striking structural repair and functional improvement in comparison to ADSCgfp− subset. Notably, ADSCgfp+ injection triggered significant quantity of dedifferentiated cardiomyocytes recognized as round-sharp, marginalization of sarcomeric proteins, expression of molecular signature of non-myogenic genes (Vimentin, RunX1), and proliferative markers (Ki-67, Aurora B and pH3). In the cultured neonatal cardiomyocytes, spontaneous dedifferentiation was accelerated by adding tissue extracts from the ADSC-treated hearts, which was neutralized by IL-6 antibody. Genetical lack of IL-6 in ADSC dampened cardiac dedifferentiation and reparative activity. Conclusions Taken collectively, our results revealed a previous unappreciated effect of IL-6 on cardiac dedifferentiation and regeneration. The finding, therefore, fulfills the promise of stem cell therapy and may represent an innovative strategy in the treatment of ischemic heart disease.

Cardiac commitment driven by MyoD expression in pericardial stem cells

“…In the present experiments, we showed that cardiac commitment occurred in an in vivo scenario in which the pericardial layer expanded in cell numbers and adhered to the heart surface after MI ( Figure 1A ). After isolation, pSCs were demonstrated to be phenotypically identical to mesenchymal stem cells with minimal contamination of hematopoietic and endothelial lineages ( Wang et al, 2014 ; Tang et al, 2018 ; Zhu et al, 2022 ). After myogenic induction in vitro , pSCs formed myoblast-like clusters and gave rise to cardiac lineage under low-serum cultivation.…”

“…We have previously demonstrated that pericardial tissue harbors a stem cell pool, known as pSCs, that, trained by inflammatory signaling, evolved into a specialized population with boosted reparative activity and myogenic potential ( Tang et al, 2018 ; Zhu et al, 2022 ; Zhu et al, 2023 ). However, we found that the cardiac benefits of the transplanted pSCs were solely mediated by paracrine factors released, whereas the pre-committed cells were poorly retained in the heart and negligibly converted into cardiomyocytes in vivo ( Tang et al, 2018 ; Zhu et al, 2022 ). To this end, it is of particular interest to determine whether pSCs after cardiac commitment are able to survive and stably engraft in the recipient heart as well as the differentiated CMs derived from pluripotent stem cells.…”

Ferroptosis and Autophagy-Related Genes in the Pathogenesis of Ischemic Cardiomyopathy

“…After validation using GEO datasets and MI mice model, the 10 hub genes, such as IL-6, PTGS2, JUN, NQO1, NOS3, LEPR, NAMPT, CDKN2A, CDKN1A, and Snai1, can be the diagnostic ferroptosis- and autophagy-related targets and biomarkers in MI deterioration and can be targets to prevent adverse cardiac events. IL-6, as a protective cytokine, promoted cellular dedifferentiation and led to pericardial ADSC-induced cardiac repair ( 32 ). Higher IL-6 levels were independently correlated to the risk of major adverse cardiovascular events (MACE), and elevated IL-6 level was associated with an increased risk of MACE at normal kidney function, mild chronic kidney disease (CKD), and moderate to severe CKD ( 33 ).…”

Comorbidity of Anxiety and Hypertension: Common Risk Factors and Potential Mechanisms

“…Interleukin-6 (IL-6) stimulates chronic inflammation and regulates the expression of C-reactive protein and cardiovascular disease risk biomarker [ 47 ]. IL-6 is related to angiotensin II (Ang-II)-mediated hypertension [ 48 ].…”