Macrophage-derived FGFR1 drives atherosclerosis through PLCγ-mediated activation of NF-κB inflammatory signaling pathway.

BACKGROUND: Atherosclerosis is a leading cause of cardiovascular morbidity and mortality. Atherosclerotic lesions show increased levels of proteins associated with the fibroblast growth factor receptor (FGFR) pathway. However, the functional significance and mechanisms governed by FGFR signaling in atherosclerosis are not known. In the present study, we investigated FGFR1 signaling in atherosclerosis development and progression. METHODS AND RESULTS: Examination of human atherosclerotic lesions and aortas of Apoe-/- mice fed a high-fat diet (HFD) showed increased levels of FGFR1 in macrophages. We deleted myeloid-expressed Fgfr1 in Apoe-/- mice and showed that Fgfr1 deficiency reduces atherosclerotic lesions and lipid accumulations in both male and female mice upon HFD feeding. These protective effects of myeloid Fgfr1 deficiency were also observed when mice with intact FGFR1 were treated with FGFR inhibitor AZD4547. To understand the mechanistic basis of this protection, we harvested macrophages from mice and show that FGFR1 is required for macrophage inflammatory responses and uptake of oxidized LDL. RNA sequencing showed that FGFR1 activity is mediated through phospholipase-C-gamma (PLCγ) and the activation of nuclear factor-κB (NF-κB) but is independent of FGFR substrate 2. CONCLUSION: Our study provides evidence of a new FGFR1-PLCγ- NF-κB axis in macrophages in inflammatory atherosclerosis, supporting FGFR1 as a potentially therapeutic target for atherosclerosis-related diseases.

Patchouli Alcohol Protects the Heart against Diabetes-Related Cardiomyopathy through the JAK2/STAT3 Signaling Pathway.

Diabetic cardiomyopathy (DCM) represents a common pathological state brought about by diabetes mellitus (DM). Patchouli alcohol (PatA) is known for its diverse advantageous effects, notably its anti-inflammatory properties and protective role against metabolic disorders. Despite this, the influence of PatA on DCM remains relatively unexplored. To explore the effect of PatA on diabetes-induced cardiac injury and dysfunction in mice, streptozotocin (STZ) was used to mimic type 1 diabetes in mice. Serological markers and echocardiography show that PatA treatment protects the heart against cardiomyopathy by controlling myocardial fibrosis but not by reducing hyperglycemia in diabetic mice. Discovery Studio 2017 software was used to perform reverse target screening of PatA, and we found that JAK2 may be a potential target of PatA. RNA-seq analysis of heart tissues revealed that PatA activity in the myocardium was primarily associated with the inflammatory fibrosis through the Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of the transcription 3 (STAT3) pathway. In vitro, we also found that PatA alleviates high glucose (HG) + palmitic acid (PA)-induced fibrotic and inflammatory responses via inhibiting the JAK2/STAT3 signaling pathway in H9C2 cells. Our findings illustrate that PatA mitigates the effects of HG + PA- or STZ-induced cardiomyopathy by acting on the JAK2/STAT3 signaling pathway. These insights indicate that PatA could potentially serve as a therapeutic agent for DCM treatment.

Hyperglycemia activates FGFR1 via TLR4/c-Src pathway to induce inflammatory cardiomyopathy in diabetes.

Protein tyrosine kinases (RTKs) modulate a wide range of pathophysiological events in several non-malignant disorders, including diabetic complications. To find new targets driving the development of diabetic cardiomyopathy (DCM), we profiled an RTKs phosphorylation array in diabetic mouse hearts and identified increased phosphorylated fibroblast growth factor receptor 1 (p-FGFR1) levels in cardiomyocytes, indicating that FGFR1 may contribute to the pathogenesis of DCM. Using primary cardiomyocytes and H9C2 cell lines, we discovered that high-concentration glucose (HG) transactivates FGFR1 kinase domain through toll-like receptor 4 (TLR4) and c-Src, independent of FGF ligands. Knocking down the levels of either TLR4 or c-Src prevents HG-activated FGFR1 in cardiomyocytes. RNA-sequencing analysis indicates that the elevated FGFR1 activity induces pro-inflammatory responses via MAPKs-NFκB signaling pathway in HG-challenged cardiomyocytes, which further results in fibrosis and hypertrophy. We then generated cardiomyocyte-specific FGFR1 knockout mice and showed that a lack of FGFR1 in cardiomyocytes prevents diabetes-induced cardiac inflammation and preserves cardiac function in mice. Pharmacological inhibition of FGFR1 by a selective inhibitor, AZD4547, also prevents cardiac inflammation, fibrosis, and dysfunction in both type 1 and type 2 diabetic mice. These studies have identified FGFR1 as a new player in driving DCM and support further testing of FGFR1 inhibitors for possible cardioprotective benefits.

Liver fat as a dietary target by Chinese Medical Nutrition Therapy (CMNT) diet for treating type 2 diabetes with non-alcoholic fatty liver disease: study protocol for a randomised controlled trial.

INTRODUCTION: Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) often coexist and increase risk for developing liver fibrosis and diabetes complications if no effective measures are taken. Dietary intervention is known to be able to achieve diabetes remission, while evidence regarding the long-term effect on liver fat is limited for comorbidity management of type 2 diabetes and NAFLD. This study aims to investigate the long-term effect of a Chinese Medical Nutrition Therapy (CMNT) diet accompanied by intermittent energy restriction on reducing liver fat and glycated haemoglobin (HbA1c) in patients with type 2 diabetes and NAFLD. METHODS AND ANALYSIS: This is a multicentre two-armed parallel randomised controlled trial study. 120 participants with type 2 diabetes and NAFLD will be recruited from the physical examination centres of multiple hospitals in China. Participants will be randomly allocated 1:1 to either the CMNT group or the usual care group. The CMNT group will be instructed to consume the provided specific meal replacement Chinese medicinal foods consisting of 6 cycles of 5 consecutive days followed by 10 days of regular food intake. The usual care group will be given standard dietary advice. Primary outcomes are changes in the controlled attenuation parameter value by transient elastography and HbA1c level. Secondary outcomes include differences in anthropometrics, clinical blood markers, questionnaires, gut microbiota and metabolomics. Further follow-up will be performed at 6 months, 1 year and 2 years. ETHICS AND DISSEMINATION: The study protocol was approved by the Biomedical Research Ethics Committee of Hunan Agricultural University (BRECHAU20200235).The results will be disseminated via relevant peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT05439226.

Compound SJ-12 attenuates streptozocin-induced diabetic cardiomyopathy by stabilizing SERCA2a.

Heart failure (HF) is one of the major causes of death among diabetic patients. Although studies have shown that curcumin analog C66 can remarkably relieve diabetes-associated cardiovascular and kidney complications, the role of SJ-12, SJ-12, a novel curcumin analog, in diabetic cardiomyopathy and its molecular targets are unknown. 7-week-old male C57BL/6 mice were intraperitoneally injected with single streptozotocin (STZ) (160 mg/kg) to develop diabetic cardiomyopathy (DCM). The diabetic mice were then treated with SJ-12 via gavage for two months. Body weight, fast blood glucose, cardiac utrasonography, myocardial injury markers, pathological morphology of the heart, hypertrophic and fibrotic markers were assessed. The potential target of SJ-12 was evaluated via RNA-sequencing analysis. The O-GlcNAcylation levels of SP1 were detected via immunoprecipitation. SJ-12 effectively suppressed myocardial hypertrophy and fibrosis, thereby preventing heart dysfunction in mice with STZ-induced heart failure. RNA-sequencing analysis revealed that SJ-12 exerted its therapeutic effects through the modulation of the calcium signaling pathway. Furthermore, SJ-12 reduced the O-GlcNAcylation levels of SP1 by inhibiting O-linked N-acetylglucosamine transferase (OGT). Also, SJ-12 stabilized Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 2a (SERCA2a), a crucial regulator of calcium homeostasis, thus reducing hypertrophy and fibrosis in mouse hearts and cultured cardiomyocytes. However, the anti-fibrotic effects of SJ-12 were not detected in SERCA2a or OGT-silenced cardiomyocytes, indicating that SJ-12 can prevent DCM by targeting OGT-dependent O-GlcNAcylation of SP1.These findings indicate that SJ-12 can exert cardioprotective effects in STZ-induced mice by reducing the O-GlcNAcylation levels of SP1, thus stabilizing SERCA2a and reducing myocardial fibrosis and hypertrophy. Therefore, SJ-12 can be used for the treatment of diabetic cardiomyopathy.

NKX2-1-AS1 promotes the lymphangiogenesis of lung adenocarcinoma through regulation of ERG-mediated FABP4.

Lymphatic metastasis is a common metastasis of lung adenocarcinoma (LUAD). The current study illustrated the action of lncRNA NKX2-1-AS1 in lymphangiogenesis in LUAD and the underlying mechanisms. Clinical tissue samples were collected for determining NKX2-1-AS1 expression. Then, H441 and H661 cells were selected to perform gain- and loss-of-function assays for dissecting the roles of NKX2-1-AS1 in LUAD cell proliferation and migration. Besides, H441 and H661 cell supernatant was harvested to stimulate HLECs for assessing tube formation ability. Interaction among NKX2-1-AS1, ERG, and fatty acid binding protein 4 (FABP4) was validated through luciferase and RIP assays. NKX2-1-AS1 was highly-expressed in LUAD tissues. Silencing NKX2-1-AS1 suppressed H441 and H661 cell proliferation and migration, reduced expression levels of lymphangiogenesis-related factors (LYVE-1, VEGF-C, VEGFR3, VEGF-A, VEGFR2, and CCR7), and inhibited HLEC tube formation. Interaction validation demonstrated that NKX2-1-AS1 regulated FABP4 transcription by binding to ERG. Overexpression of FABP4 could effectively block the inhibition role of NKX2-1-AS1 silencing in lymphangiogenesis in H441 and H661 cells. This study provided evidence that NKX2-1-AS1 regulated FABP4 transcription by binding to ERG to facilitate the proliferation and migration of LUAD cells and tube formation of HLECs, thus participating in lymphangiogenesis.

Discovery of a doublecortin-like kinase 1 inhibitor to prevent inflammatory responses in acute lung injury.

Doublecortin-like kinase 1 (DCLK1) is a microtubule-associated protein kinase involved in neurogenesis and human cancer. Recent studies have revealed a novel functional role for DCLK1 in inflammatory signaling, thus positioning it as a novel target kinase for respiratory inflammatory disease treatment. In this study, we designed and synthesized a series of NVP-TAE684-based derivatives as novel anti-inflammatory agents targeting DCLK1. Bio-layer interferometry binding screening and kinase assays of the NVP-TAE684 derivatives led to the discovery of an effective DCLK1 inhibitor (a24), with an IC50 of 179.7 nM. Compound a24 effectively inhibited lipopolysaccharide (LPS)-induced inflammation in macrophages with higher potency than the lead compound. Mechanistically, compound a24 inhibited LPS-induced inflammation by inhibiting DCLK1-mediated IKKß phosphorylation. Furthermore, compound a24 showed in vivo anti-inflammatory activity in an LPS-challenged acute lung injury model. These findings suggest that compound a24 may serve as a novel candidate for the development of DCLK1 inhibitors and a potential therapeutic agent for the treatment of inflammatory diseases.

Initial Upper Palaeolithic material culture by 45,000 years ago at Shiyu in northern China.

The geographic expansion of Homo sapiens populations into southeastern Europe occurred by ∼47,000 years ago (∼47 ka), marked by Initial Upper Palaeolithic (IUP) technology. H. sapiens was present in western Siberia by ∼45 ka, and IUP industries indicate early entries by ∼50 ka in the Russian Altai and 46-45 ka in northern Mongolia. H. sapiens was in northeastern Asia by ∼40 ka, with a single IUP site in China dating to 43-41 ka. Here we describe an IUP assemblage from Shiyu in northern China, dating to ∼45 ka. Shiyu contains a stone tool assemblage produced by Levallois and Volumetric Blade Reduction methods, the long-distance transfer of obsidian from sources in China and the Russian Far East (800-1,000 km away), increased hunting skills denoted by the selective culling of adult equids and the recovery of tanged and hafted projectile points with evidence of impact fractures, and the presence of a worked bone tool and a shaped graphite disc. Shiyu exhibits a set of advanced cultural behaviours, and together with the recovery of a now-lost human cranial bone, the record supports an expansion of H. sapiens into eastern Asia by about 45 ka.

OTUD1 promotes isoprenaline- and myocardial infarction-induced heart failure by targeting PDE5A in cardiomyocytes.

Heart failure represents a major cause of death worldwide. Recent research has emphasized the potential role of protein ubiquitination/deubiquitination protein modification in cardiac pathology. Here, we investigate the role of the ovarian tumor deubiquitinase 1 (OTUD1) in isoprenaline (ISO)- and myocardial infarction (MI)-induced heart failure and its molecular mechanism. OTUD1 protein levels were raised markedly in murine cardiomyocytes after MI and ISO treatment. OTUD1 deficiency attenuated myocardial hypertrophy and cardiac dysfunction induced by ISO infusion or MI operation. In vitro, OTUD1 knockdown in neonatal rat ventricular myocytes (NRVMs) attenuated ISO-induced injuries, while OTUD1 overexpression aggravated the pathological changes. Mechanistically, LC-MS/MS and Co-IP studies showed that OTUD1 bound directly to the GAF1 and PDEase domains of PDE5A. OTUD1 was found to reverse K48 ubiquitin chain in PDE5A through cysteine at position 320 of OTUD1, preventing its proteasomal degradation. PDE5A could inactivates the cGMP-PKG-SERCA2a signaling axis which dysregulate the calcium handling in cardiomyocytes, and leading to the cardiomyocyte injuries. In conclusion, OTUD1 promotes heart failure by deubiquitinating and stabilizing PDE5A in cardiomyocytes. These findings have identified PDE5A as a new target of OTUD1 and emphasize the potential of OTUD1 as a target for treating heart failure.

JOSD2 mediates isoprenaline-induced heart failure by deubiquitinating CaMKIIδ in cardiomyocytes.

Prolonged stimulation of ß-adrenergic receptor (ß-AR) can lead to sympathetic overactivity that causes pathologic cardiac hypertrophy and fibrosis, ultimately resulting in heart failure. Recent studies suggest that abnormal protein ubiquitylation may contribute to the pathogenesis of cardiac hypertrophy and remodeling. In this study, we demonstrated that deficiency of a deubiquitinase, Josephin domain-containing protein 2 (JOSD2), ameliorated isoprenaline (ISO)- and myocardial infarction (MI)-induced cardiac hypertrophy, fibrosis, and dysfunction both in vitro and in vivo. Conversely, JOSD2 overexpression aggravated ISO-induced cardiac pathology. Through comprehensive mass spectrometry analysis, we identified that JOSD2 interacts with Calcium-calmodulin-dependent protein kinase II (CaMKIIδ). JOSD2 directly hydrolyzes the K63-linked polyubiquitin chains on CaMKIIδ, thereby increasing the phosphorylation of CaMKIIδ and resulting in calcium mishandling, hypertrophy, and fibrosis in cardiomyocytes. In vivo experiments showed that the cardiac remodeling induced by JOSD2 overexpression could be reversed by the CaMKIIδ inhibitor KN-93. In conclusion, our study highlights the role of JOSD2 in mediating ISO-induced cardiac remodeling through the regulation of CaMKIIδ ubiquitination, and suggests its potential as a therapeutic target for combating the disease. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. All have been checked.

Isoproterenol induces MD2 activation by ß-AR-cAMP-PKA-ROS signalling axis in cardiomyocytes and macrophages drives inflammatory heart failure.

Cardiac inflammation contributes to heart failure (HF) induced by isoproterenol (ISO) through activating ß-adrenergic receptors (ß-AR). Recent evidence shows that myeloid differentiation factor 2 (MD2), a key protein in endotoxin-induced inflammation, mediates inflammatory heart diseases. In this study, we investigated the role of MD2 in ISO-ß-AR-induced heart injuries and HF. Mice were infused with ISO (30 mg·kg-1·d-1) via osmotic mini-pumps for 2 weeks. We showed that MD2 in cardiomyocytes and cardiac macrophages was significantly increased and activated in the heart tissues of ISO-challenged mice. Either MD2 knockout or administration of MD2 inhibitor L6H21 (10 mg/kg every 2 days, i.g.) could prevent mouse hearts from ISO-induced inflammation, remodelling and dysfunction. Bone marrow transplantation study revealed that both cardiomyocyte MD2 and bone marrow-derived macrophage MD2 contributed to ISO-induced cardiac inflammation and injuries. In ISO-treated H9c2 cardiomyocyte-like cells, neonatal rat primary cardiomyocytes and primary mouse peritoneal macrophages, MD2 knockout or pre-treatment with L6H21 (10 µM) alleviated ISO-induced inflammatory responses, and the conditioned medium from ISO-challenged macrophages promoted the hypertrophy and fibrosis in cardiomyocytes and fibroblasts. We demonstrated that ISO induced MD2 activation in cardiomyocytes via ß1-AR-cAMP-PKA-ROS signalling axis, and induced inflammatory responses in macrophages via ß2-AR-cAMP-PKA-ROS axis. This study identifies MD2 as a key inflammatory mediator and a promising therapeutic target for ISO-induced heart failure.

OTUD1 promotes hypertensive kidney fibrosis and injury by deubiquitinating CDK9 in renal epithelial cells.

Hypertensive renal disease (HRD) contributes to the progression of kidney dysfunction and ultimately leads to end-stage renal disease. Understanding the mechanisms underlying HRD is critical for the development of therapeutic strategies. Deubiquitinating enzymes (DUBs) have been recently highlighted in renal pathophysiology. In this study, we investigated the role of a DUB, OTU Domain-Containing Protein 1 (OTUD1), in HRD models. HRD was induced in wild-type or Otud1 knockout mice by chronic infusion of angiotensin II (Ang II, 1 µg/kg per min) through a micro-osmotic pump for 4 weeks. We found that OTUD1 expression levels were significantly elevated in the kidney tissues of Ang II-treated mice. Otud1 knockout significantly ameliorated Ang II-induced HRD, whereas OTUD1 overexpression exacerbated Ang II-induced kidney damage and fibrosis. Similar results were observed in TCMK-1 cells but not in SV40 MES-13 cells following Ang II (1 µM) treatment. In Ang II-challenged TCMK-1 cells, we demonstrated that OTUD1 bound to CDK9 and induced CDK9 deubiquitination: OTUD1 catalyzed K63 deubiquitination on CDK9 with its Cys320 playing a critical role, promoting CDK9 phosphorylation and activation to induce inflammatory responses and fibrosis in kidney epithelial cells. Administration of a CDK9 inhibitor NVP-2 significantly ameliorated Ang II-induced HRD in mice. This study demonstrates that OTUD1 mediates HRD by targeting CDK9 in kidney epithelial cells, suggesting OTUD1 is a potential target in treating this disease.

OTUD6A in tubular epithelial cells mediates angiotensin II-induced kidney injury by targeting STAT3.

Kidney fibrosis is a prominent pathological feature of hypertensive kidney diseases (HKD). Recent studies have highlighted the role of ubiquitinating/deubiquitinating protein modification in kidney pathophysiology. Ovarian tumor domain-containing protein 6 A (OTUD6A) is a deubiquitinating enzyme involved in tumor progression. However, its role in kidney pathophysiology remains elusive. We aimed to investigate the role and underlying mechanism of OTUD6A during kidney fibrosis in HKD. The results revealed higher OTUD6A expression in kidney tissues of nephropathy patients and mice with chronic angiotensin II (Ang II) administration than that from the control ones. OTUD6A was mainly located in tubular epithelial cells. Moreover, OTUD6A deficiency significantly protected mice against Ang II-induced kidney dysfunction and fibrosis. Also, knocking OTUD6A down suppressed Ang II-induced fibrosis in cultured tubular epithelial cells, whereas overexpression of OTUD6A enhanced fibrogenic responses. Mechanistically, OTUD6A bounded to signal transducer and activator of transcription 3 (STAT3) and removed K63-linked-ubiquitin chains to promote STAT3 phosphorylation at tyrosine 705 position and nuclear translocation, which then induced profibrotic gene transcription in epithelial cells. These studies identified STAT3 as a direct substrate of OTUD6A and highlighted the pivotal role of OTUD6A in Ang II-induced kidney injury, indicating OTUD6A as a potential therapeutic target for HKD.NEW & NOTEWORTHY Ovarian tumor domain-containing protein 6 A (OTUD6A) knockout mice are protected against angiotensin II-induced kidney dysfunction and fibrosis. OTUD6A promotes pathological kidney remodeling and dysfunction by deubiquitinating signal transducer and activator of transcription 3 (STAT3). OTUD6A binds to and removes K63-linked-ubiquitin chains of STAT3 to promote its phosphorylation and activation, and subsequently enhances kidney fibrosis.

20(S)-ginsenoside Rh2 inhibits angiotensin-2 mediated cardiac remodeling and inflammation associated with suppression of the JNK/AP-1 pathway.

BACKGROUND: Enhanced levels of angiotensin-2 (Ang-II) causes hypertensive heart failure (HHF) through non-hemodynamical and hemodynamical alterations. 20(S)-ginsenoside Rh2 (20(S)-Rh2) is a natural ginseng compound with numerous cardiovascular benefits. This investigation elucidates the influence of 20(S)-Rh2 on Ang-II-induced heart failure and cardiac alterations. METHODS: Ang-II was administered in C57BL/6 mice for 4 weeks to induce HHF. In the last 2 weeks of treatment, 20(S)-Rh2 was orally administered in mice to assess the potential 20(S)-Rh2 mechanism. Subsequently, RNA sequencing was carried out. RESULTS: It was indicated that 20(S)-Rh2 suppresses myocardial fibrosis, hypertrophy, and inflammation, thereby inhibiting cardiac disruption in Ang-II-challenged mice without affecting blood pressure. According to the RNA sequencing data, this cardio-protective effect was linked with the (JNK)/AP 1 pathway. 20(S)-Rh2 alleviated heart tissue and cardiomyocytes inflammation by inhibiting the Ang-II-mediated JNK/AP-1 pathway. Within cardiomyocytes, JNK or AP-1 absence abolished the anti-inflammatory effects of 20(S)-Rh2. CONCLUSION: This study investigation indicated that 20(S)-Rh2 prevents cardiovascular dysfunction induced by Ang-II induced by decreasing JNK-regulated inflammatory responses, providing evidence for its use as an efficient regimen for HHF.

Inhibition of MD2 by natural product-drived JM-9 attenuates renal inflammation and diabetic nephropathy in mice.

Diabetic kidney disease (DKD) is one of the severe complications of diabetes mellitus-related microvascular lesions, which remains the leading cause of end-stage kidney disease. The genesis and development of DKD is closely related to inflammation. Myeloid differentiation 2 (MD2) mediates hyperlyciemia-induced renal inflammation and DKD development and is considered as a potential therapeutic target of DKD. Here, we identified a new small-molecule MD2 inhibitor, JM-9. In vitro, JM-9 suppressed high glucose (HG) and palmitic acid (PA)-induced inflammation in MPMs, accompanied by inhibition of MD2 activation and the downstream TLR4/MyD88-MAPKs/NFκB pro-inflammatory signaling pathway. Macrophage-derived factors increased the fibrotic and inflammatory responses in renal tubular epithelial cells, which were inhibited by treating macrophages with JM-9. Then, we investigated the therapeutic effects against DKD in streptozotocin-induced type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) mouse models. Treatment with JM-9 prevented renal inflammation, fibrosis, and dysfunction by targeting MD2 in both T1DM and T2DM models. Our results show that JM-9, a new small-molecule MD2 inhibitor, protects against DKD by targeting MD2 and inhibiting MD2-mediated inflammation. In summary, JM-9 is a potential therapeutic agent for DKD.

Compound c17 alleviates inflammatory cardiomyopathy in streptozotocin-induced diabetic mice by targeting MyD88.

BACKGROUND: Diabetic cardiomyopathy (DCM) is a common complication of diabetes mellitus and is associated with increased morbidity and mortality due to cardiac dysfunction. Chronic inflammation plays a significant role in the development of DCM, making it a promising target for novel pharmacological strategies. Our previous study has synthesized a novel compound, c17, which exhibited strong anti-inflammatory activity by specifically targeting to myeloid differentiation primary response 88 (MyD88). In this study, we evaluated the therapeutic effect of c17 in DCM. METHODS: The small molecular selective MyD88 inhibitor, c17, was used to evaluate the effect of MyD88 on DCM in both high concentration of glucose- and palmitic acid-stimulated macrophages and streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) mice. RESULTS: The treatment of c17 in T1DM mice resulted in improved heart function and reduced cardiac hypertrophy, inflammation and fibrogenesis. RNA sequencing analysis of the heart tissues revealed that c17 effectively suppressed the inflammatory response by regulating the MyD88-dependent pathway. Co-immunoprecipitation experiments further confirmed that c17 disrupted the interaction between MyD88 and Toll-like receptor 4 (TLR4), consequently inhibiting downstream NF-κB activation. In vitro studies demonstrated that c17 exhibited similar anti-inflammatory activity by targeting MyD88 in macrophages, which are the primary regulators of cardiac inflammation. Furthermore, conditioned medium derived from c17-treated macrophages showed reduced capacity to induce hypertrophy, pro-fibrotic reactions, and secondary inflammation in cardiomyocytes. CONCLUSIONS: In conclusion, the small-molecule MyD88 inhibitor, c17, effectively combated the inflammatory DCM, therefore could be a potential candidate for the treatment of this disease.

Macrophage DCLK1 promotes obesity-induced cardiomyopathy via activating RIP2/TAK1 signaling pathway.

Obesity increases the risk for cardiovascular diseases and induces cardiomyopathy. Chronic inflammation plays a significant role in obesity-induced cardiomyopathy and may provide new therapeutic targets for this disease. Doublecortin-like kinase 1 (DCLK1) is an important target for cancer therapy and the role of DCLK1 in obesity and cardiovascular diseases is unclear. Herein, we showed that DCLK1 was overexpressed in the cardiac tissue of obese mice and investigated the role of DCLK1 in obesity-induced cardiomyopathy. We generated DCLK1-deleted mice and showed that macrophage-specific DCLK1 knockout, rather than cardiomyocyte-specific DCLK1 knockout, prevented high-fat diet (HFD)-induced heart dysfunction, cardiac hypertrophy, and fibrosis. RNA sequencing analysis showed that DCLK1 deficiency exerted cardioprotective effects by suppressing RIP2/TAK1 activation and inflammatory responses in macrophages. Upon HFD/palmitate (PA) challenge, macrophage DCLK1 mediates RIP2/TAK1 phosphorylation and subsequent inflammatory cytokine release, which further promotes hypertrophy in cardiomyocytes and fibrogenesis in fibroblasts. Finally, a pharmacological inhibitor of DCLK1 significantly protects hearts in HFD-fed mice. Our study demonstrates a novel role and a pro-inflammatory mechanism of macrophage DCLK1 in obesity-induced cardiomyopathy and identifies DCLK1 as a new therapeutic target for the treatment of this disease. Upon HFD/PA challenge, DCLK1 induces RIP2/TAK1-mediated inflammatory response in macrophages, which subsequently promotes cardiac hypertrophy and fibrosis. Macrophage-specific DCLK1 deletion or pharmacological inhibition of DCLK1 protects hearts in HFD-fed mice.

Macrophage Dectin-1 mediates Ang II renal injury through neutrophil migration and TGF-ß1 secretion.

Macrophage activation has been shown to play an essential role in renal fibrosis and dysfunction in hypertensive chronic kidney disease. Dectin-1 is a pattern recognition receptor that is also involved in chronic noninfectious diseases through immune activation. However, the role of Dectin-1 in Ang II-induced renal failure is still unknown. In this study, we found that Dectin-1 expression on CD68 + macrophages was significantly elevated in the kidney after Ang II infusion. We assessed the effect of Dectin-1 on hypertensive renal injury using Dectin-1-deficient mice infused by Angiotensin II (Ang II) at 1000 ng/kg/min for 4 weeks. Ang II-induced renal dysfunction, interstitial fibrosis, and immune activation were significantly attenuated in Dectin-1-deficient mice. A Dectin-1 neutralizing antibody and Syk inhibitor (R406) were used to examine the effect and mechanism of Dectin-1/Syk signaling axle on cytokine secretion and renal fibrosis in culturing cells. Blocking Dectin-1 or inhibiting Syk significantly reduced the expression and secretion of chemokines in RAW264.7 macrophages. The in vitro data showed that the increase in TGF-ß1 in macrophages enhanced the binding of P65 and its target promotor via the Ang II-induced Dectin-1/Syk pathway. Secreted TGF-ß1 caused renal fibrosis in kidney cells through Smad3 activation. Thus, macrophage Dectin-1 may be involved in the activation of neutrophil migration and TGF-ß1 secretion, thereby promoting kidney fibrosis and dysfunction.