Distinct immune subsets have been demonstrated to participate in hypertensive vascular remodeling. This study investigated whether the aryl hydrocarbon receptor (AHR) plays a regulatory role in Angiotensin II (Ang II)-induced vascular injury via the regulation of Th22/IL-22 signaling and ferroptosis. Using a mouse model of Ang II-induced hypertension and vascular remodeling, we observed that the AHR antagonist CH-223191 significantly alleviated hypertension, aortic media thickens, and fibrosis. Mechanistically, AHR inhibition downregulated Th22 cell differentiation and suppressed the activation of the IL-22/STAT3 pathway, which subsequently inhibited oxidative stress and ferritinophagy in vascular smooth muscle cells (VSMCs). Conversely, the adoptive transfer of Th22 cells aggravated vascular remodeling and VSMC phenotypic switching. Furthermore, pharmacological inhibition of ferroptosis with Ferrostatin-1 phenocopied the protective effects of the AHR antagonist and reversed IL-22-induced phenotypic switching. In conclusion, AHR activation aggravates Ang II-induced vascular remodeling by promoting Th22 cell differentiation and IL-22/STAT3-mediated ferroptosis in VSMCs.

Growing evidence positions Factor XI (FXI) as a promising anticoagulation target, where its role in pathological thrombus formation significantly outweighs its contribution to physiological hemostasis. This distinctive pathophysiological profile has propelled FXI inhibition as a transformative therapeutic paradigm, with multiple candidates in Phase I-III trials spanning venous thromboembolism prophylaxis to arterial thrombosis prevention. Building on emerging insights into FXI-mediated vascular inflammation and remodeling, we herein unveil the first preclinical evidence supporting KN060-a humanized dual-domain antibody simultaneously targeting FXI-A2/A3 epitopes-as a novel antihypertensive agent. In angiotensin II-challenged mice, 5-week KN060 monotherapy (10 mg/kg triweekly) elicited sustained systolic blood pressure (SBP) reduction of 27.8 mmHg (120.7 mmHg in KN060 group vs 148.5 mmHg in vehicle control group). Furthermore, in spontaneously hypertensive rats, 9-week KN060 monotherapy (15 mg/kg twice weekly) achieved sustained SBP reduction of 34.7 mmHg (172.2 mmHg in KN060 group vs 206.9 mmHg in vehicle control group), concomitantly reducing left ventricular mass (0.67 g vs 0.773 g) and aortic relative media thickness (28.74 vs 31.59). Notably, co-administration of KN060 (3 mg/kg) with losartan (5 mg/kg) in SHRs demonstrated synergistic efficacy, achieving greater SBP reduction than losartan monotherapy (ΔSBP: -23.7 mmHg vs -15.9 mmHg). These findings establish KN060 as a first-in-class therapeutic bridging anticoagulation and vascular protection. Its unique bispecific architecture enables near-complete FXI activity inhibition while preserving hemostatic capacity, addressing critical limitations of conventional RAAS blockers in resistant hypertension. With an ongoing Phase Ib trial in primary hypertension patients (NMPA approval No CXSL2400827), KN060 emerges as a transformative candidate for precision management of hypertension.

Metabolic reprogramming is a pivotal mechanism in the pathogenesis of pathological cardiac hypertrophy. Leucine-rich repeat-containing G protein-coupled receptor 6 (Lgr6) has emerged as a significant player in cardiovascular diseases. In this study, the potential of Lgr6 to counteract pressure overload (PO)-induced cardiac hypertrophy is investigated, and the underlying mechanisms involved are elucidated. Transverse aortic constriction (TAC) is induced to establish an in vivo cardiac hypertrophy model. Adeno-associated virus 9 and adenovirus vectors are utilized to knock down and overexpress Lgr6 in cardiomyocytes, respectively. The effects of Lgr6 and its downstream molecules are subsequently determined using RNA sequencing and chromatin immunoprecipitation. Significant downregulation of Lgr6 expression is observed in the heart after TAC and in cardiomyocytes treated with phenylephrine. Lgr6 deficiency accelerated and Lgr6 overexpression inhibits cardiac hypertrophy and dysfunction after TAC. Mechanistically, the in vivo and in vitro experiments suggest that Lgr6 regulates the expression of ubiquitin specific protease 4 (USP4) and peroxisome proliferator-activated receptor alpha (PPARα) by activating the cGMP/PKG/CREB1 signalling pathway, thereby regulating cardiomyocyte metabolic reprogramming after PO. Targeting Lgr6 can be a potential therapeutic strategy to treat pathological cardiac hypertrophy.

Aim KCP has been demonstrated to be involved in cardiac remodeling and cardiac aging. This study aims to investigate whether KCP plays a regulatory role in doxorubicin (DOX)-induced cardiac injury by modulating immune and inflammatory responses. Result The expression of KCP in the left ventricle of a mouse model with doxorubicin-induced myocardial injury was detected using real-time quantitative PCR, Western blot, and immunofluorescence staining. The cardiac function of wild-type (WT) mice and KCP knockout (KO) mice was assessed via echocardiography, and histological analysis was further confirmed through immunofluorescence staining and HE staining. Bone marrow-derived macrophages (BMDM) were extracted from both wild-type (WT) mice and KCP knockout (KO) mice, and RNA sequencing was performed after doxorubicin treatment to identify differentially expressed genes and related signaling pathways. BMDM was utilized to validate the regulatory role and potential mechanisms of KCP in macrophage M1 polarization and the inflammatory response process. Studies have found that KCP expression is downregulated in the doxorubicin-induced myocardial injury model, and in vitro experiments revealed that doxorubicin treatment reduces KCP expression in BMDMs. KCP deficiency significantly exacerbates doxorubicin-induced cardiac dysfunction and myocardial injury, and promotes M1 polarization of macrophages. RNA sequencing results showed that KCP deficiency is associated with autophagy and the p38 MAPK signaling pathway after doxorubicin treatment. Further in vivo and in vitro studies suggest that KCP deficiency inhibits the autophagy process in BMDMs through the p38 MAPK/m-TOR pathway. Conslusion These results indicate that KCP deficiency exacerbates doxorubicin-induced myocardial injury in mice by promoting M1 polarization of BMDM through the p38 MAPK/m-TOR signaling pathway-mediated suppression of autophagy.

Hypertension is one of the leading causes of death due to target organ injury from cardiovascular disease. Although there are many treatments, only one-sixth of hypertensive patients effectively control their blood pressure. Therefore, further understanding the pathogenesis of hypertension is essential for the treatment of hypertension. Much research shows that immune cells play an important role in the pathogenesis of hypertension. Here, we discuss the roles of different immune cells in hypertension. Many immune cells participate in innate and adaptive immune responses, such as monocytes/macrophages, neutrophils, dendritic cells, NK cells, and B and T lymphocytes. Immune cells infiltrate the blood vessels, kidneys, and hearts and cause damage. The mechanism is that immune cells secrete cytokines such as interleukin, interferon, and tumor necrosis factor, which affect the inflammatory reaction, oxidative stress, and kidney sodium water retention, and finally aggravate or reduce the dysfunction, remodeling, and fibrosis of the blood vessel, kidney, and heart to participate in blood pressure regulation. This article reviews the research progress on immune cells and hypertension.

Hypertensive vascular remodeling is defined as the changes in vascular function and structure induced by persistent hypertension. Maresin-1 (MaR1), one of metabolites from Omega-3 fatty acids, has been reported to promote inflammation resolution in several inflammatory diseases. This study aims to investigate the effect of MaR1 on hypertensive vascular remodeling. Here, we found serum MaR1 levels were reduced in hypertensive patients and was negatively correlated with systolic blood pressure (SBP). The treatment of MaR1 reduced the elevation of blood pressure and alleviated vascular remodeling in the angiotensin II (AngII)-infused mouse model. In addition, MaR1-treated vascular smooth muscle cells (VSMCs) exhibited reduced excessive proliferation, migration, and phenotype switching, as well as impaired pyroptosis. However, the knockout of the receptor of MaR1, leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6), was seen to aggravate pathological vascular remodeling, which could not be reversed by additional MaR1 treatment. The mechanisms by which MaR1 regulates vascular remodeling through LGR6 involves the Ca2+/calmodulin-dependent protein kinase II/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway. Overall, supplementing MaR1 may be a novel therapeutic strategy for the prevention and treatment of hypertension.

Cardiovascular diseases have been identified as vital factors in global morbidity and mortality in recent years. The available evidence suggests that various cytokines and pathological proteins participate in these complicated and changeable diseases. The thrombospondin (TSP) family is a series of conserved, multidomain calcium-binding glycoproteins that cause cell-matrix and cell-cell effects via interactions with other extracellular matrix components and cell surface receptors. The TSP family has five members that can be divided into two groups (Group A and Group B) based on their different structures. TSP-1, TSP-2, and TSP-4 are the most studied proteins. Among recent studies and findings, we investigated the functions of several family members, especially TSP-5. We review the basic concepts of TSPs and summarize the relevant molecular mechanisms and cell interactions in the cardiovascular system. Targeting TSPs in CVD and other diseases has a remarkable therapeutic benefit.

Background Dilated cardiomyopathy (DCM) is the leading cause of heart failure with a poor prognosis. Recent studies suggest that endothelial to mesenchymal transition (EndMT) may be involved in the pathogenesis and cardiac remodeling during DCM development. EDIL3 (epidermal growth factor‐like repeats and discoidin I‐like domains 3) is an extracellular matrix glycoprotein that has been reported to promote EndMT in various diseases. However, the roles of EDIL3 in DCM still remain unclear. Methods and Results A mouse model of DCM and human umbilical vein endothelial cells were used to explore the roles and mechanisms of EDIL3 in DCM. The results indicated that EndMT and EDIL3 were activated in DCM mice. EDIL3 deficiency attenuated cardiac dysfunction and remodeling in DCM mice. EDIL3 knockdown alleviated EndMT by inhibiting USP10 (ubiquitin specific peptidase 10) dependent Smad4 deubiquitination in vivo and in vitro. Recombinant human EDIL3 promoted EndMT via reinforcing deubiquitination of Smad4 in human umbilical vein endothelial cells treated with IL‐1β (interleukin 1β) and TGF‐β (transforming growth factor beta). Inhibiting USP10 abolished EndMT exacerbated by EDIL3. In addition, recombinant EDIL3 also aggravates doxorubicin‐induced EndMT by promoting Smad4 deubiquitination in HUVECs. Conclusions Taken together, these results indicate that EDIL3 deficiency attenuated EndMT by inhibiting USP10 dependent Smad4 deubiquitination in DCM mice.

The resolution of inflammation, the other side of the inflammatory response, is defined as an active and highly coordinated process that promotes the restoration of immune microenvironment balance and tissue repair. Inflammation resolution involves several key processes, including dampening proinflammatory signaling, specialized proresolving lipid mediator (SPM) production, nonlipid proresolving mediator production, efferocytosis and regulatory T-cell (Treg) induction. In recent years, increasing attention has been given to the effects of inflammation resolution on hypertension. Furthermore, our previous studies reported the antihypertensive effects of SPMs. Therefore, in this review, we aim to summarize and discuss the detailed association between arterial hypertension and inflammation resolution. Additional, the association between gut microbe-mediated immune and hypertension is discussed. This findings suggested that accelerating the resolution of inflammation can have beneficial effects on hypertension and its related organ damage. Exploring novel drug targets by focusing on various pathways involved in accelerating inflammation resolution will contribute to the treatment and control of hypertensive diseases in the future.

BACKGROUND:The interleukin (IL) -12 p40 subunit is the common subunit of IL-12 and IL-23. It affects the immune inflammatory response, which may be closely related to cardiac remodeling. In this study, the regulatory effect of IL-12p40 knockout (KO) on cardiac remodeling was investigated, and the underlying mechanism was explored. METHODS AND RESULTS:Mice were subjected to transverse aortic constriction (TAC) to establish a model of cardiac remodeling. First, IL-12p40 was deleted to observe its effects on cardiac remodeling and cardiac inflammation, and the results showed that IL-12p40 deletion reduced both T helper 17 (Th17) and γδT17 cell differentiation, decreased proinflammatory macrophage differentiation, alleviated cardiac remodeling, and relieved cardiac dysfunction in TAC mice. Next, we explored whether IL-17 regulated TAC-induced cardiac remodeling, and the results showed that IL-17 neutralization alleviated proinflammatory macrophage differentiation and cardiac remodeling in IL-12p40 knockout mice and WT mice. Neutralization with cluster of differentiation 4 receptor (CD4) and γδ T-cell receptor (γδTCR) antibodies inhibited pro-inflammatory macrophage polarization and improved cardiac remodeling, and CD4 neutralizing antibody (NAb) had more significant effects. Finally, adoptive transfer of Th17 cells aggravated proinflammatory macrophage differentiation and cardiac remodeling in TAC-treated CD4 KO mice, while neutralization with the IL-12p40 antibody alleviated these pathological changes. CONCLUSION:Mainly Th17 cells but not γδT17 cells secrete IL-17, which mediates IL-12p40, promotes the polarization of proinflammatory macrophages, and exacerbates cardiac remodeling in TAC mice. IL-12p40 may be a potential target for the prevention and treatment of cardiac remodeling.

Thoracic aortic dissection (TAD) is a severe disease, characterized by numerous apoptotic vascular smooth muscle cells (VSMCs). EDIL3/Del-1 is a secreted protein involved in macrophage efferocytosis in acute inflammation. Here, we aimed to investigate whether EDIL3 promoted the internalization and degradation of apoptotic VSMCs during TAD. The levels of EDIL3 were decreased in the serum and aortic tissue from TAD mice. Global edil3 knockout (edil3-/-) mice and edil3-/- bone marrow chimeric mice exhibited a considerable exacerbation in beta-aminopropionitrile monofumarate (BAPN)-induced TAD, accompanied with increased apoptotic VSMCs accumulating in the damaged aortic tissue. Two types of phagocytes, RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were used for in vitro efferocytosis assay. edil3-deficient phagocytes exhibited inefficient internalization and degradation of apoptotic VSMCs. Instead, EDIL3 promoted the internalization phase through interacting with phosphatidylserine (PtdSer) on apoptotic VSMCs and binding to the macrophage ITGAV/alpha v-ITGB3/beta 3 integrin. In addition, EDIL3 accelerated the degradation phase through activating LC3-associated phagocytosis (LAP). Mechanically, following the engulfment, EDIL3 enhanced the activity of SMPD1/acid sphingomyelinase in the phagosome through blocking ITGAV-ITGB3 integrin, which facilitates phagosomal reactive oxygen species (ROS) production by NAPDH oxidase CYBB/NOX2. Furthermore, exogenous EDIL3 supplementation alleviated BAPN-induced TAD and promoted apoptotic cell clearance. EDIL3 may be a novel factor for the prevention and treatment of TAD.Abbreviations: BAPN: beta-aminopropionitrile monofumarate; BMDM: bone marrow-derived macrophage; C12FDG: 5-dodecanoylaminofluorescein-di-beta-D-galactopyranoside; CTRL: control; CYBB/NOX2: cytochrome b-245, beta polypeptide; DCFH-DA: 2',7'-dichlorofluorescin diacetate; EDIL3/Del-1: EGF-like repeats and discoidin I-like domains 3; EdU: 5-ethynyl-2'-deoxyuridine; EVG: elastic van Gieson; H&E: hematoxylin and eosin; IL: interleukin; LAP: LC3-associated phagocytosis; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; NAC: N-acetylcysteine; PtdSer: phosphatidylserine; rEDIL3: recombinant EDIL3; ROS: reactive oxygen species; SMPD1: sphingomyelin phosphodiesterase 1; TAD: thoracic aortic dissection; TEM: transmission electron microscopy; VSMC: vascular smooth muscle cell; WT: wild-type

BackgroundInterleukin-23p19 (IL-23p19) has been demonstrated to be involved in the occurrence and development of cardiovascular diseases such as myocardial infarction and atherosclerosis. This study aimed to examine whether IL-23p19 regulates cardiac remodeling processes and explore its possible mechanisms.Methods and resultsTransverse aortic constriction was performed to construct a mouse cardiac remodeling model, and sham surgery was used as a control. The results showed that IL-23p19 expression was increased in the heart after surgery and may be mainly produced by cardiac macrophages. Knockout of IL-23p19 attenuated M1 macrophage polarization, reduced ferroptosis, improved the process of cardiac remodeling and alleviated cardiac dysfunction in TAC mice. Cell culture experiments found that macrophages were the main cause of ferroptosis when phenylephrine (PE) was added, and blocking ferroptosis with ferrostatin-1 (Fer-1), a ferroptosis inhibitor, significantly inhibited M1 macrophage polarization. Treatment with Fer-1 also improved cardiac remodeling and alleviated cardiac dysfunction in IL-23p19-/- mice subjected to TAC surgery. Finally, TAC IL-23p19-/- mice that were administered macrophages isolated from WT mice exhibited an increased proportion of M1 macrophages and aggravated cardiac remodeling, and these effects were reversed when Fer-1 was administered.ConclusionKnockout of IL-23p19 may attenuate M1 macrophage polarization to improve the cardiac remodeling process by reducing macrophage ferroptosis, and IL-23p19 may be a potential target for the prevention and treatment of cardiac remodeling.

Aims Interleukin (IL)-12p40 is a common subunit of the bioactive cytokines IL-12 and IL-23, and it also has its own intrinsic functional activity. However, its role in doxorubicin-induced chronic cardiomyopathy (DICCM) as well as the underlying mechanisms are still unknown.Methods and results In this study, we used IL-12p40-knockout mice, IL-23p19-knockout mice, Rag1-knockout mice, a ferroptosis inhibitor, recombinant IL-12 (rIL-12), rIL-23, rIL-12p40, rIL-12p80, and anti-IL17A to investigate the effects of IL-12p40 on DICCM and elucidate the underlying mechanisms. We found that myocardial ferroptosis were increased in DICCM and that the inhibition of ferroptosis protected against DICCM. The expression of IL-12p40 was upregulated, and IL-12p40 was predominantly expressed by CD4+ T cells in the hearts of mice with DICCM. IL-12p40 knockout attenuated cardiac dysfunction, fibrosis and ferroptosis in DICCM, and similar results were observed in the context of CD4+ T cell IL-12p40 deficiency in Rag1-/- mice. Treatment with rIL-23, but not rIL-12, rIL-12p40 monomer or rIL-12p80, abolished the protective effects of IL-12p40 knockout. Moreover, rIL-23 treatment and IL-23p19 knockout exacerbated and ameliorated DICCM, respectively. IL-12p40 knockout might protect against DICCM by inhibiting Th17 differentiation and IL-17A production but not Th1, Th2 and Treg differentiation. Neutralizing IL-17A with an antibody also attenuated cardiac dysfunction, fibrosis, and ferroptosis. The IL-12p40/Th17/IL-17A axis might promote cardiomyocyte ferroptosis by activating TNF receptor-associated factor 6 (TRAF6)/mitogen-activated protein kinase (MAPK)/P53 signalling in DICCM.Conclusion Interleukin-12p40 deficiency protects against DICCM by inhibiting Th17 differentiation and the production of IL-17A, which plays critical roles in cardiomyocyte ferroptosis in DICCM via activating TRAF6/MAPK/P53 signalling. Our study may provide novel insights for the identification of therapeutic targets for treating DICCM in the clinic. Graphical Abstract

Abstract Immunomodulatory agents represent an important recent advance in cancer therapy, but utility is often limited by tumor immune evasion mechanisms. Strategic therapeutic activation of intracellular antiviral immune responses offers an opportunity to reverse immune evasion mechanisms and improve treatment outcomes. Anti-cancer agents such as, DNA methyltransferase inhibitors (DNMTis) induce re-expression of endogenous retroviral elements (ERVs), leading to cytosolic double-stranded RNA (dsRNA) accumulation that activates interferon/inflammasome signaling. Moreover, poly (ADP ribose) polymerase inhibitors (PARPi) increase cytosolic dsDNA leading to activation of stimulator of interferon genes (STING). We previously reported in triple negative breast cancer (TNBC) and ovarian cancer (OC) that DNMTis in combination with PARPi induce STING-dependent interferon/inflammasome signaling in a process termed pathogen mimicry response (PMR). Mitochondria (mt) are an important gateway for antiviral inflammasome signaling, but upstream activating events in cancer are not understood. We now show NFX1-type zinc finger–containing 1 (ZNFX1), a little-studied innate immune gene, acts as a master nucleic acid (dsRNA/DNA) sensor for this mt gateway function. Importantly, in primary ovarian tumors from TCGA and clinical trial RNAseq datasets, increased ZNFX1 expression tracks with tumor stage and grade but inversely correlates with a mt dysfunction signature. In studies of high grade serous (TYK-nu, OVCAR4) as well as endometrial ovarian (A2780) cancer cells, transfection of dsRNA/DNA mimics or DNMTi azacytidine (AZA) and PARPi (talazoparib) treatments induce increased ZNFX1 expression and binding to mt antiviral protein (MAVs) localized on the mt outer membrane, using immunofluorescence-based proximity ligation assays. In studies of mt dysfunction, we further show that dsRNA/DNA as well as above-described anti-cancer drugs increase mt reactive oxygen species (ROS), using flow cytometry of ROS dye mitoSOX. DNMTi and PARPi treatments also increase fragmented mtDNA and oxidative mtDNA base damage, as measured long range PCR and 8-oxoguanine (8-oxoG) ELISA assays, respectively. Importantly, these drug treatment increase release of mtDNA into the cytosol, resulting in STING-dependent inflammasome signaling and cytokine release. ZNFX1 knockout robustly attenuates these dynamics, thus defining this immune gene as essential for interferon/inflammasome signaling induced by mtDNA damage. Our data indicates a master role for the little-studied dsRNA/DNA sensor ZNFX1 in initiating a pathogen mimicry response to DNMTi and PARPi combination treatment, and further highlights the critical role of the mt in cellular antiviral signaling mechanisms. Importantly, this work suggests a novel avenue for manipulation of inflammasome signaling to improve cancer therapy responses and disease outcomes. Citation Format: Lora Stojanovic, Rachel Abbotts, Kaushlendra Tripathi, Collin M. Coon, Sheng Liu, Jun Wan, Michael J. Topper, Kenneth P. Nephew, Stephen B. Baylin, Feyruz V. Rassool. ZNFX1 is a master regulator for epigenetic reprograming of mitochondrial inflammasome signaling and pathogen mimicry in cancer cells [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr PR-005.

Targeting cardiac remodeling is regarded as a key therapeutic strategy for heart failure. Kielin/chordin-like protein (KCP) is a secretory protein with 18 cysteine-rich domains and associated with kidney and liver fibrosis. However, the relationship between KCP and cardiac remodeling remains unclear. Here, we aimed to investigate the role of KCP in cardiac remodeling induced by pressure overload and explore its potential mechanisms. Left ventricular (LV) KCP expression was measured with real-time quantitative PCR, western blotting, and immunofluorescence staining in pressure overload-induced cardiac remodeling in mice. Cardiac function and remodeling were evaluated in wide-type (WT) mice and KCP knockout (KO) mice by echocardiography, which were further confirmed by histological analysis with hematoxylin and eosin and Masson staining. RNA sequence was performed with LV tissue from WT and KO mice to identify differentially expressed genes and related signaling pathways. Primary cardiac fibroblasts (CFs) were used to validate the regulatory role and potential mechanisms of KCP during fibrosis. KCP was down-regulated in the progression of cardiac remodeling induced by pressure overload, and was mainly expressed in fibroblasts. KCP deficiency significantly aggravated pressure overload-induced cardiac dysfunction and remodeling. RNA sequence revealed that the role of KCP deficiency in cardiac remodeling was associated with cell division, cell cycle, and P53 signaling pathway, while cyclin B1 (CCNB1) was the most significantly up-regulated gene. Further investigation in vivo and in vitro suggested that KCP deficiency promoted the proliferation of CFs via P53/P21/CCNB1 pathway. Taken together, these results suggested that KCP deficiency aggravates cardiac dysfunction and remodeling induced by pressure overload via P53/P21/CCNB1 signaling in mice.

Aims The majority of people with diabetes are susceptible to cardiac dysfunction and heart failure, and conventional drug therapy cannot correct the progression of diabetic cardiomyopathy. We assessed the potential role and therapeutic value of LGR6 (G protein-coupled receptor containing leucine-rich repeats 6) in diabetic cardiomyopathy. Methods and results Type 2 diabetes models were established using high-fat diet/streptozotocin-induced diabetes in mice. LGR6 knockout mice were generated. Recombinant adeno-associated virus serotype 9 carrying LGR6 under the cardiac troponin T promoter was injected into diabetic mice. Cardiomyocytes incubated with high glucose (HG) were used to imitate diabetic cardiomyopathy in vitro. The molecular mechanism was explored through RNA sequencing and a chromatin immunoprecipitation assay. We found that LGR6 expression was upregulated in diabetic hearts and HL1 cardiomyocytes treated with HG. The LGR6 knockout aggravated, but cardiomyocyte-specific LGR6 overexpression ameliorated, cardiac dysfunction and remodeling in diabetic mice. Mechanistically, in vivo and in vitro experiments revealed that LGR6 deletion aggravated, whereas LGR6 overexpression alleviated, ferroptosis and disrupted mitochondrial biogenesis by regulating STAT3/Pgc1a signaling. STAT3 inhibition and Pgc1a activation abrogated LGR6 knockout-induced mitochondrial dysfunction and ferroptosis in diabetic mice. In addition, LGR6 activation by recombinant RSPO3 treatment ameliorated cardiac dysfunction, ferroptosis and mitochondrial dysfunction in diabetic mice. Conclusions We identified a previously undescribed signaling pathway of the LGR6-STAT3-Pgc1a axis that plays a critical role in ferroptosis and mitochondrial disorders during diabetic cardiomyopathy and provides an option for treatment of diabetic hearts.