Collecting duct NCOR1 controls blood pressure by regulating mineralocorticoid receptor.

INTRODUCTION: Nuclear receptor corepressor 1(NCOR1) is reported to play crucial roles in cardiovascular diseases, but its function in the kidney has remained obscure. OBJECTIVE: We aim to elucidate the role of collecting duct NCOR1 in blood pressure (BP) regulation. METHODS AND RESULTS: Collecting duct NCOR1 knockout (KO) mice manifested increased BP and aggravated vascular and renal injury in an angiotensin II (Ang II)-induced hypertensive model. KO mice also showed significantly higher BP than littermate control (LC) mice in deoxycorticosterone acetate (DOCA)-salt model. Further study showed that collecting duct NCOR1 deficiency aggravated volume and sodium retention after saline challenge. Among the sodium transporter in the collecting duct, the expression of the three epithelial sodium channel (ENaC) subunits was markedly increased in the renal medulla of KO mice. Consistently, BP in Ang II-infused KO mice decreased significantly to the similar level as those in LC mice after amiloride treatment. ChIP analysis revealed that NCOR1 deficiency increased the enrichment of mineralocorticoid receptor (MR) on the promoters of the three ENaC genes in primary inner medulla collecting duct (IMCD) cells. Co-IP results showed interaction between NCOR1 and MR, and luciferase reporter results demonstrated that NCOR1 inhibited the transcriptional activity of MR. Knockdown of MR eliminated the increased ENaC expression in primary IMCD cells isolated from KO mice. Finally, BP was significantly decreased in Ang II-infused KO mice after treatment of MR antagonist spironolactone and the difference between LC and KO mice was abolished. CONCLUSIONS: NCOR1 interacts with MR to control ENaC activity in the collecting duct and to regulate sodium reabsorption and ultimately BP. Targeting NCOR1 might be a promising tactic to interrupt the volume and sodium retention of the collecting duct in hypertension.

Altered salivary microbiota profile in patients with abdominal aortic aneurysm.

Evidence suggests that the DNA of oral pathogens is detectable in the dilated aortic tissue of abdominal aortic aneurysm (AAA), one of the most fatal cardiovascular diseases. However, the association between oral microbial homeostasis and aneurysm formation remains largely unknown. In this study, a cohort of individuals, including 53 AAA patients and 30 control participants (CTL), was recruited for salivary microbiota investigation by 16S rRNA gene sequencing and bioinformatics analysis. Salivary microbial diversity was decreased in AAA compared with CTL, and the microbial structures were significantly separated between the two groups. Additionally, significant taxonomic and functional changes in the salivary microbiota of AAA participants were observed. The genera Streptococcus and Gemella were remarkably enriched, while Selenomonas, Leptotrichia, Lautropia and Corynebacterium were significantly depleted in AAA. Co-occurrence network analysis showed decreased potential interactions among the differentially abundant microbial genera in AAA. A machine-learning model predicted AAA using the combination of 5 genera and 14 differentially enriched functional pathways, which could distinguish AAA from CTL with an area under the receiver-operating curve of 90.3 %. Finally, 16 genera were found to be significantly positively correlated with the morphological parameters of AAA. Our study is the first to show that AAA patients exhibit oral microbial dysbiosis, which has high predictive power for AAA, and the over-representation of specific salivary bacteria may be associated with AAA disease progression. Further studies are needed to better understand the function of putative oral bacteria in the etiopathogenesis of AAA. Importance: Host microbial dysbiosis has recently been linked to AAA as a possible etiology. To our knowledge, studies of the oral microbiota and aneurysms remain scarce, although previous studies have indicated that the DNA of some oral pathogens is detectable in aneurysms by PCR method. We take this field one step further by investigating the oral microbiota composition of AAA patients against control participants via high-throughput sequencing technologies and unveiling the potential microbial biomarker associated with AAA formation. Our study will provide new insights into AAA etiology, treatment and prevention from a microecological perspective and highlight the effects of oral microbiota on vascular health.

Low-intensity pulsed ultrasound alleviates doxorubicin-induced cardiotoxicity via inhibition of S100a8/a9-mediated cardiac recruitment of neutrophils.

Doxorubicin (DOX)-induced cardiotoxicity limits its broad use as a chemotherapy agent. The development of effective and non-invasive strategies to prevent DOX-associated adverse cardiac events is urgently needed. We aimed to examine whether and how low-intensity pulsed ultrasound (LIPUS) plays a protective role in DOX-induced cardiotoxicity. Male C57BL/6J mice were used to establish models of both acute and chronic DOX-induced cardiomyopathy. Non-invasive LIPUS therapy was conducted for four consecutive days after DOX administration. Cardiac contractile function was evaluated by echocardiography. Myocardial apoptosis, oxidative stress, and fibrosis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining, dihydroethidium (DHE) staining, and picrosirius red staining assays. RNA-seq analysis was performed to unbiasedly explore the possible downstream regulatory mechanisms. Neutrophil recruitment and infiltration in the heart were analyzed by flow cytometry. The S100a8/a9 inhibitor ABR-238901 was utilized to identify the effect of S100a8/a9 signaling. We found that LIPUS therapy elicited a great benefit on DOX-induced heart contractile dysfunction in both acute and chronic DOX models. Chronic DOX administration increased serum creatine kinase and lactate dehydrogenase levels, as well as myocardial apoptosis, all of which were significantly mitigated by LIPUS. In addition, LIPUS treatment prevented chronic DOX-induced cardiac oxidative stress and fibrosis. RNA-seq analysis revealed that LIPUS treatment partially reversed alterations of gene expression induced by DOX. Gene ontology (GO) analysis of the downregulated genes between DOX-LIPUS and DOX-Sham groups indicated that inhibition of neutrophil chemotaxis might be involved in the protective effects of LIPUS therapy. Flow cytometry analysis illustrated the inhibitory effects of LIPUS on DOX-induced neutrophil recruitment and infiltration in the heart. Moreover, S100 calcium binding protein A8/A9 (S100a8/a9) was identified as a potential key target of LIPUS therapy. S100a8/a9 inhibition by ABR-238901 showed a similar heart protective effect against DOX-induced cardiomyopathy to LIPUS treatment. LIPUS therapy prevents DOX-induced cardiotoxicity through inhibition of S100a8/a9-mediated neutrophil recruitment to the heart, suggesting its potential application in cancer patients undergoing chemotherapy with DOX.

Oral pathogens exacerbate Parkinson's disease by promoting Th1 cell infiltration in mice.

BACKGROUND: Parkinson's disease (PD) is a common chronic neurological disorder with a high risk of disability and no cure. Periodontitis is an infectious bacterial disease occurring in periodontal supporting tissues. Studies have shown that periodontitis is closely related to PD. However, direct evidence of the effect of periodontitis on PD is lacking. Here, we demonstrated that ligature-induced periodontitis with application of subgingival plaque (LIP-SP) exacerbated motor dysfunction, microglial activation, and dopaminergic neuron loss in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice. RESULTS: The 16S rRNA gene sequencing revealed that LIP-SP induced oral and gut dysbiosis. Particularly, Veillonella parvula (V. parvula) and Streptococcus mutans (S. mutans) from oral ligatures were increased in the fecal samples of MPTP + LIP-SP treated mice. We further demonstrated that V. parvula and S. mutans played crucial roles in LIP-SP mediated exacerbation of motor dysfunction and neurodegeneration in PD mice. V. parvula and S. mutans caused microglial activation in the brain, as well as T helper 1 (Th1) cells infiltration in the brain, cervical lymph nodes, ileum and colon in PD mice. Moreover, we observed a protective effect of IFNγ neutralization on dopaminergic neurons in V. parvula- and S. mutans-treated PD mice. CONCLUSIONS: Our study demonstrates that oral pathogens V. parvula and S. mutans necessitate the existence of periodontitis to exacerbate motor dysfunction and neurodegeneration in MPTP-induced PD mice. The underlying mechanisms include alterations of oral and gut microbiota, along with immune activation in both brain and peripheral regions. Video Abstract.

Integrated Omic Analysis of Human Plasma Metabolites and Microbiota in a Hypertension Cohort.

Hypertension is closely related to metabolic dysregulation, which is associated with microbial dysbiosis and altered host-microbiota interactions. However, plasma metabolite profiles and their relationships to oral/gut microbiota in hypertension have not been evaluated in depth. Plasma, saliva, subgingival plaques, and feces were collected from 52 hypertensive participants and 24 healthy controls in a cross-sectional cohort. Untargeted metabolomic profiling of plasma was performed using high-performance liquid chromatography-mass spectrometry. Microbial profiling of oral and gut samples was determined via 16S rRNA and metagenomic sequencing. Correlations between metabolites and clinic parameters/microbiota were identified using Spearman's correlation analysis. Metabolomic evaluation showed distinct clusters of metabolites in plasma between hypertensive participants and control participants. Hypertensive participants had six significantly increased and thirty-seven significantly decreased plasma metabolites compared to controls. The plasma metabolic similarity significantly correlated with the community similarity of microbiota. Both oral and gut microbial community composition had significant correlations with metabolites such as Sphingosine 1-phosphate, a molecule involved in the regulation of blood pressure. Plasma metabolites had a larger number of significant correlations with bacterial genera than fungal genera. The shared oral/gut bacterial genera had more correlations with metabolites than unique genera but shared fungal genera and metabolites did not show clear clusters. The hypertension group had fewer correlations between plasma metabolites and bacteria/fungi than controls at species level. The integrative analysis of plasma metabolome and oral/gut microbiome identified unreported alterations of plasma metabolites in hypertension and revealed correlations between altered metabolites and oral/gut microbiota. These observations suggested metabolites and microbiota may become valuable targets for therapeutic and preventive interventions of hypertension.

An IL-6/STAT3/MR/FGF21 axis mediates heart-liver cross-talk after myocardial infarction.

The liver plays a protective role in myocardial infarction (MI). However, very little is known about the mechanisms. Here, we identify mineralocorticoid receptor (MR) as a pivotal nexus that conveys communications between the liver and the heart during MI. Hepatocyte MR deficiency and MR antagonist spironolactone both improve cardiac repair after MI through regulation on hepatic fibroblast growth factor 21 (FGF21), illustrating an MR/FGF21 axis that underlies the liver-to-heart protection against MI. In addition, an upstreaming acute interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) pathway transmits the heart-to-liver signal to suppress MR expression after MI. Hepatocyte Il6 receptor deficiency and Stat3 deficiency both aggravate cardiac injury through their regulation on the MR/FGF21 axis. Therefore, we have unveiled an IL-6/STAT3/MR/FGF21 signaling axis that mediates heart-liver cross-talk during MI. Targeting the signaling axis and the cross-talk could provide new strategies to treat MI and heart failure.

Alleviate Periodontitis and Its Comorbidity Hypertension using a Nanoparticle-Embedded Functional Hydrogel System.

Periodontitis and hypertension often occur as comorbidities, which need to be treated at the same time. To resolve this issue, a controlled-release composite hydrogel approach is proposed with dual antibacterial and anti-inflammatory activities as a resolution to achieve the goal of co-treatment of comorbidities. Specifically, chitosan (CS) with inherent antibacterial properties is cross-linked with antimicrobial peptide (AMP)-modified polyethylene glycol (PEG) to form a dual antibacterial hydrogel (CS-PA). Subsequently, curcumin loaded into biodegradable nanoparticles (CNP) are embedded in the hydrogel exhibiting high encapsulation efficiency and sustained release to achieve long-term anti-inflammatory activities. In a mouse model of periodontitis complicated with hypertension, CS-PA/CNP is applied to gingival sulcus and produced an optimal therapeutic effect on periodontitis and hypertension simultaneously. The therapeutic mechanisms are deeply studied and indicated that CS-PA/CNP exerted excellent immunoregulatory effects by suppressing the accumulation of lymphocytes and myeloid cells and enhanced the antioxidant capacity and thus the anti-inflammatory capacity of macrophages through the glutathione metabolism pathway. In conclusion, CS-PA/CNP has demonstrated its superior therapeutic effects and potential clinical translational value in the co-treatment of periodontitis and hypertension, and also serves as a drug delivery platform to provide combinatorial therapeutic options for periodontitis with complicated pathogenesis.

Periodontitis exacerbates atherosclerosis through Fusobacterium nucleatum-promoted hepatic glycolysis and lipogenesis.

AIMS: Positive associations between periodontitis (PD) and atherosclerosis have been established, but the causality and mechanisms are not clear. We aimed to explore the causal roles of PD in atherosclerosis and dissect the underlying mechanisms. METHODS AND RESULTS: A mouse model of PD was established by ligation of molars in combination with application of subgingival plaques collected from PD patients and then combined with atherosclerosis model induced by treating atheroprone mice with a high-cholesterol diet (HCD). PD significantly aggravated atherosclerosis in HCD-fed atheroprone mice, including increased en face plaque areas in whole aortas and lesion size at aortic roots. PD also increased circulating levels of triglycerides and cholesterol, hepatic levels of cholesterol, and hepatic expression of rate-limiting enzymes for lipogenesis. Using 16S ribosomal RNA (rRNA) gene sequencing, Fusobacterium nucleatum was identified as the most enriched PD-associated pathobiont that is present in both the oral cavity and livers. Co-culture experiments demonstrated that F. nucleatum directly stimulated lipid biosynthesis in primary mouse hepatocytes. Moreover, oral inoculation of F. nucleatum markedly elevated plasma levels of triglycerides and cholesterol and promoted atherogenesis in HCD-fed ApoE-/- mice. Results of RNA-seq and Seahorse assay indicated that F. nucleatum activated glycolysis, inhibition of which by 2-deoxyglucose in turn suppressed F. nucleatum-induced lipogenesis in hepatocytes. Finally, interrogation of the molecular mechanisms revealed that F. nucleatum-induced glycolysis and lipogenesis by activating PI3K/Akt/mTOR signalling pathway in hepatocytes. CONCLUSIONS: PD exacerbates atherosclerosis and impairs lipid metabolism in mice, which may be mediated by F. nucleatum-promoted glycolysis and lipogenesis through PI3K/Akt/mTOR signalling in hepatocytes. Treatment of PD and specific targeting of F. nucleatum are promising strategies to improve therapeutic effectiveness of hyperlipidaemia and atherosclerosis.

T-Cell Mineralocorticoid Receptor Deficiency Attenuates Pathologic Ventricular Remodelling After Myocardial Infarction.

BACKGROUND: Mineralocorticoid receptor (MR) antagonists have been widely used to treat heart failure (HF). Studies have shown that MR in T cells plays important roles in hypertension and myocardial hypertrophy. However, the function of T-cell MR in myocardial infarction (MI) has not been elucidated. METHODS: In this study, we used T-cell MR knockout (TMRKO) mouse to investigate the effects of T-cell MR deficiency on MI and to explore the underlying mechanisms. Echocardiography and tissue staining were used to assess cardiac function, fibrosis, and myocardial apoptosis after MI. Flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect immune cell infiltration and inflammation. RESULTS: T-cell MR deficiency significantly improved cardiac function, promoted myocardial repair, and inhibited myocardial apoptosis, fibrosis, and inflammation after MI. Luminex assays revealed that TMRKO mice had significantly lower levels of interferon-gamma (IFN-γ) and interleukin-6 (IL-6) in serum and infarcted myocardium than littermate control mice. In cultured splenic T cells, MR deficiency suppressed IL-6 expression, whereas MR overexpression enhanced IL-6 expression. Chromatin immunoprecipitation (ChIP) assay demonstrated that MR bound to the MR response element on the promoter of IL-6 gene. Finally, T-cell MR deficiency significantly suppressed accumulation of macrophages in infarcted myocardium and differentiation of proinflammatory macrophages, thereby alleviating the consequences of MI. CONCLUSIONS: T-cell MR deficiency improved pathologic ventricular remodelling after MI, likely through inhibition of accumulation and differentiation of proinflammatory macrophages. At the molecular level, MR may work through IFN-γ and IL-6 in T cells to exert functions in MI.

Roles of oral microbiota and oral-gut microbial transmission in hypertension.

INTRODUCTION: Considerable evidence has linked periodontitis (PD) to hypertension (HTN), but the nature behind this connection is unclear. Dysbiosis of oral microbiota leading to PD is known to aggravate different systematic diseases, but the alteration of oral microbiota in HTN and their impacts on blood pressure (BP) remains to be discovered. OBJECTIVES: To characterize the alterations of oral and gut microbiota and their roles in HTN. METHODS: We performed a cross-sectional (95 HTN participants and 39 controls) and a 6-month follow-up study (52 HTN participants and 26 controls) to analyze the roles of oral and gut microbiota in HTN. Saliva, subgingival plaques, and feces were collected for 16S rRNA gene sequencing or metagenomic analysis. C57BL/6J mice were pretreated with antibiotics to deplete gut microbiota, and then transplanted with human saliva by gavage to test the impacts of abnormal oral-gut microbial transmission on HTN. RESULTS: BP in participants with PD was higher than no PD in both cross-sectional and follow-up cohort. Relative abundances of 14 salivary genera, 15 subgingival genera and 10 gut genera significantly altered in HTN and those of 7 salivary genera, 12 subgingival genera and 6 gut genera significantly correlated with BP. Sixteen species under 5 genera were identified as oral-gut transmitters, illustrating the presence of oral-gut microbial transmission in HTN. Veillonella was a frequent oral-gut transmitter stably enriched in HTN participants of both cross-sectional and follow-up cohorts. Saliva from HTN participants increased BP in hypertensive mice. Human saliva-derived Veillonella successfully colonized in mouse gut, more abundantly under HTN condition. CONCLUSIONS: PD and oral microbiota are strongly associated with HTN, likely through oral-gut transmission of microbes. Ectopic colonization of saliva-derived Veillonella in the gut may aggravate HTN. Therefore, precise manipulations of oral microbiota and/or oral-gut microbial transmission may be useful strategies for better prevention and treatment of HTN.

Characteristics and Correlations of the Oral and Gut Fungal Microbiome with Hypertension.

The mycobiome is an essential constituent of the human microbiome and is associated with various diseases. However, the role of oral and gut fungi in hypertension (HTN) remains largely unexplored. In this study, saliva, subgingival plaques, and feces were collected from 36 participants with HTN and 24 healthy controls for metagenomic sequencing. The obtained sequences were analyzed using the Kraken2 taxonomic annotation pipeline to assess fungal composition and diversity. Correlations between oral and gut fungi and clinic parameters, between fungi within the same sample types, and between different sample types were identified by Spearman's correlation analysis. Overall, the subgingival fungal microbiome had substantially higher alpha diversity than the salivary and fecal fungal microbiomes. The fungal microbiomes of the three sample types displayed distinct beta diversity from each other. Oral fungi but not gut fungi in HTN had beta diversity significantly different from that of controls. Among the fungi shared in the oral cavity and gut, Exophiala was the genus with the most notable changes. Exophiala spinifera was the most abundant salivary species in HTN. Some fungal species directly correlated with blood pressure, including gut Exophiala xenobiotica and Exophiala mesophila. The markedly impaired ecological cocorrelation networks of oral and gut fungi in HTN suggested compromised association among fungal species. Most fungi were shared in the oral cavity and gut, and their correlations suggested the potential interplays between oral and gut fungi. In conclusion, the oral cavity and intestine have unique fungal ecological environments. The fungal enrichment and ecology in HTN, the correlations between oral and gut fungi, and the associations between oral and gut fungi and clinical parameters suggest an important role that the fungal microbiome may play in HTN. IMPORTANCE Our study fills the gap in human studies investigating the oral and gut fungal microbiota in association with blood pressure. It characterizes the diversity and composition of the oral and gut fungal microbiome in human subjects, elucidates the dysbiosis of fungal ecology in a hypertensive population, and establishes oral-gut fungal correlations and fungus-clinical parameter correlations. Targeting fungi in the oral cavity and/or gut may provide novel strategies for the prevention and treatment of hypertension.

NCOR1 maintains the homeostasis of vascular smooth muscle cells and protects against aortic aneurysm.

Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays critical roles in the pathogenesis of aortic aneurysm (AA). The function of nuclear receptor corepressor1 (NCOR1) in regulation of VSMC phenotype and AA is unclear. Herein, using smooth muscle NCOR1 knockout mice, we demonstrated that smooth muscle NCOR1 deficiency decreased both mRNA and protein levels of contractile genes, impaired stress fibers formation and RhoA pathway activation, reduced synthesis of elastin and collagens, and induced the expression and activity of MMPs, manifesting a switch from contractile to degradative phenotype of VSMCs. NCOR1 modulated VSMC phenotype through 3 different mechanisms. First, NCOR1 deficiency increased acetylated FOXO3a to inhibit the expression of Myocd, which downregulated contractile genes. Second, deletion of NCOR1 derepressed NFAT5 to induce the expression of Rgs1, thus impeding RhoA activation. Third, NCOR1 deficiency increased the expression of Mmp12 and Mmp13 by derepressing ATF3. Finally, a mouse model combined apoE knockout mice with angiotensin II was used to study the role of smooth muscle NCOR1 in the development of AA. The results showed that smooth muscle NCOR1 deficiency increased the incidence of aortic aneurysms and exacerbated medial degeneration in angiotensin II-induced AA mouse model. Collectively, our data illustrated that NCOR1 interacts with FOXO3a, NFAT5, and ATF3 to maintain contractile phenotype of VSMCs and suppress AA development. Manipulation of smooth muscle NCOR1 may be a potential approach for AA treatment.

Periodontitis Salivary Microbiota Aggravates Ischemic Stroke Through IL-17A.

Although epidemiological studies suggest that periodontitis is tightly associated with ischemic stroke, its impact on ischemic stroke and the underlysing mechanisms are poorly understood. Recent studies have shown that alteration in gut microbiota composition influences the outcomes of ischemic stroke. In the state of periodontitis, many oral pathogenic bacteria in the saliva are swallowed and transmitted to the gut. However, the role of periodontitis microbiota in the pathogenesis and progression of ischemic stroke is unclear. Therefore, we hypothesized that the periodontitis salivary microbiota influences the gut immune system and aggravates ischemic stroke. Mice receiving gavage of periodontitis salivary microbiota showed significantly worse stroke outcomes. And these mice also manifested more severe neuroinflammation, with higher infiltration of inflammatory cells and expression of inflammatory cytokines in the ischemic brain. More accumulation of Th17 cells and IL-17+ γδ T cells were observed in the ileum. And in Kaede transgenic mice after photoconversion. Migration of CD4+ T cells and γδ T cells from the ileum to the brain was observed after ischemic stroke in photoconverted Kaede transgenic mice. Furthermore, the worse stroke outcome was abolished in the IL-17A knockout mice. These findings suggest that periodontitis salivary microbiota increased IL-17A-producing immune cells in the gut, likely promoted the migration of these cells from the gut to the brain, and subsequently provoked neuroinflammation after ischemic stroke. These findings have revealed the role of periodontitis in ischemic stroke through the gut and provided new insights into the worse outcome of ischemic stroke coexisting with periodontitis in clinical trials.

Mineralocorticoid receptor deficiency in Treg cells ameliorates DSS-induced colitis in a gut microbiota-dependent manner.

Mineralocorticoid receptor (MR) is a classic nuclear receptor and an effective drug target in the cardiovascular system. The function of MR in immune cells such as macrophages and T cells has been increasingly appreciated. The aim of this study was to investigate the function of Treg MR in the process of inflammatory bowel disease (IBD). We treated Treg MR-deficient (MRflox/flox Foxp3YFP-Cre , KO) mice and control (Foxp3YFP-Cre , WT) mice with dextran sodium sulphate (DSS) to induce colitis and found that the severity of DSS-induced colitis was markedly alleviated in Treg MR-deficient mice, accompanied by reduced production of inflammatory cytokines, and relieved infiltration of monocytes, neutrophils and interferon γ+ T cells in colon lamina propria. Faecal microbiota of mice with colitis was analysed by 16S rRNA gene sequencing and the composition of gut microbiota was vastly changed in Treg MR-deficient mice. Furthermore, depletion of gut microbiota by antibiotics abolished the protective effects of Treg MR deficiency and resulted in similar severity of DSS-induced colitis in WT and KO mice. Faecal microbiota transplantation from KO mice attenuated DSS-induced colitis characterized by alleviated inflammatory infiltration compared to that from WT mice. Hence, our study demonstrates that Treg MR deficiency protects against DSS-induced colitis by attenuation of colonic inflammatory infiltration. Gut microbiota is both sufficient and necessary for Treg MR deficiency to exert the beneficial effects.

Osteoblast MR deficiency protects against adverse ventricular remodeling after myocardial infarction.

RATIONALE: Mineralocorticoid receptor (MR) antagonists have been clinically used to treat heart failure. However, the underlying cellular and molecular mechanisms remain incompletely understood. METHODS AND RESULTS: Using osteoblast MR knockout (MRobko) mouse in combination with myocardial infarction (MI) model, we demonstrated that MR deficiency in osteoblasts significantly improved cardiac function, promoted myocardial healing, as well as attenuated cardiac hypertrophy, fibrosis and inflammatory response after MI. Gene expression profiling using RNA sequencing revealed suppressed expression of osteocalcin (OCN) in calvaria from MRobko mice compared to littermate control (MRfl/fl) mice with or without MI. Plasma levels of undercarboxylated OCN (ucOCN) were also markedly decreased in MRobko mice compared to MRfl/fl mice. Administration of ucOCN abolished the protective effects of osteoblast MR deficiency on infarcted hearts. Mechanistically, ucOCN treatment promoted proliferation and inflammatory cytokine secretion in macrophages. Spironolactone, an MR antagonist, significantly inhibited the expression and secretion of OCN in post-MI mice. More importantly, spironolactone decreased plasma levels of ucOCN and inflammatory cytokines in heart failure patients. CONCLUSIONS: MR deficiency in osteoblasts alleviates pathological ventricular remodeling after MI, likely through its regulation on OCN. Spironolactone may work through osteoblast MR/OCN axis to exert its therapeutic effects on pathological ventricular remodeling and heart failure in mice and human patients.

Macrophage Nuclear Receptor Corepressor 1 Deficiency Protects Against Ischemic Stroke in Mice.

Microglia/macrophage activation plays an essential role in Ischemic stroke (IS). Nuclear receptor corepressor 1 (NCoR1) has been identified as a vital regulator in macrophages. The present study aims to explore the functions of macrophage NCoR1 in IS. Macrophage NCoR1 knockout (MNKO) mice and littermate control mice were subjected to middle cerebral artery occlusion (MCAO). Our data showed that macrophage NCoR1 deficiency significantly reduced the infarct size and infarct volume as well as brain edema after MCAO. Additionally, MNKO induced less microglia/macrophage infiltration and activation, neuroinflammation, apoptosis of neuronal cells, and BBB disruption in brains after IS. Mechanistic studies revealed that NCoR1 interacted with LXRß in microglia and MNKO impaired the activation of the Nuclear factor-κB signaling pathway in brains after IS. Our data demonstrated that macrophage NCoR1 deficiency inhibited microglia/macrophage activation and protected against IS. Targeting NCoR1 in microglia/macrophage may be a potential approach for IS treatment.

Biomimetic Hydroxyapatite Nanorods Promote Bone Regeneration via Accelerating Osteogenesis of BMSCs through T Cell-Derived IL-22.

Manipulations of morphological properties of nanobiomaterials have been demonstrated to modulate the outcome of osteoimmunomodulation and eventually osteogenesis through innate immune response. However, the functions and mechanisms of adaptive immune cells in the process of nanobiomaterials-mediated bone regeneration have remained unknown. Herein, we developed bone-mimicking hydroxyapatite (HAp) nanorods with different aspect ratios as model materials to investigate the impacts of the nanoshape features on osteogenesis and to explore the underlying mechanisms focusing on the functions of T cells and T cell-derived cytokines. HAp nanorods with different aspect ratios (HAp-0, HAp-30, and HAp-100) were implanted into mouse mandibular defect models. Micro-CT and hematoxylin and eosin staining demonstrated that HAp-100 had the best osteogenic effects. Flow cytometry analysis revealed that HAp-100 increased the percentage of T cells in injured mandibles. The osteogenic effects of HAp-100 were significantly blunted in injured mandibles of TCRß-/- mice. The Luminex xMAP assay and ELISA showed that HAp-100 induced a marked increase of interleukin (IL)-22 in injured mandibles. In cultured T cells, HAp-100 manifested the best capacity to induce the production of IL-22. Conditioned media from HAp-100-primed T cells promoted osteogenesis and JAK1/STAT3 activation in bone marrow stromal cells, all of which were abolished by neutralizing antibodies against IL-22. In summary, bone-mimicking HAp nanorods with different aspect ratios could regulate osteogenesis through modulation of T cells and IL-22 in the bone regeneration process. These findings provided insights for mediation of the immune response of T cells by nanomaterials on osteogenesis and strategies for designing biomaterials with osteoimmunomodulative functions.

[Expression of fibroblast growth factor receptor like 1 protein in oral squamous cell carcinoma and its influence on tumor cell proliferation and migration].

OBJECTIVE: This study aims to investigate the expression of fibroblast growth factor receptor like 1 (FGFRL1) in oral squamous cell carcinoma (OSCC) and reveals its association with tumor cell proliferation and migration. METHODS: Western blot was performed to detect the expression of FGFRL1 protein in OSCC tissues, adjacent normal tissues, OSCC cell lines and normal epithelial cells. After knocking down of FGFRL1 in HN4 cells, CCK-8 and Ki67 assays were performed to detect cell proliferation, wounding healing assay and transwell were performed to detect cell-migration. Western blot was used to detect the expression of protein related to epithelial-mesenchymal transition (EMT). RESULTS: The expression of FGFRL1 in OSCC tissues was higher than that in adjacent nontumor tissues, respectively (t=2.820, P=0.047 8). Moreover, the expression of FGFRL1 in OSCC cells was higher than that in HOK cells. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that FGFRL1 expression of FGFRL1 RNA in HOK cells was lower than that in OSCC cells. HN4 cells transfected with FGFRL1 siRNA were included in the experimental group, whereas HN4 cells treated with NC siRNA were included in the control group. CCK-8 experiment showed no significant difference between the experimental and control groups with regard to proliferation ability at 48 h (P=0.478 1) and 72 h (P=0.334 2). Migration experiment showed that the wound healing areas in the experimental group after 12 h (P=0.022 8), 24 h (P=0.005 1), and 36 h (P=0.009 5）were smaller than that in the control group. Transwell invasion assay showed that the number of invaded cells in the experimental group after 16 h (P=0.008 7) and 24 h (P=0.008 6) were lower than that in the control group. Knocking-down FGFRL1 up-regulated the expression of E-cadherin and down-regulated the expression of N-cadherin and Vimentin in HN4 cells. CONCLUSIONS: FGFRL1 expression in the OSCC tissues was significantly higher than that in the adjacent nontumor tissues. FGFRL1 expression in the OSCC cells was significantly higher than that in the HOK cells, and FGFRL1 had no effect on cell proliferation but promoted tumor cell migration and EMT.

Macrophage NCOR1 Deficiency Ameliorates Myocardial Infarction and Neointimal Hyperplasia in Mice.

Background NCOR1 (nuclear receptor corepressor 1) is an essential coregulator of gene transcription. It has been shown that NCOR1 in macrophages plays important roles in metabolic regulation. However, the function of macrophage NCOR1 in response to myocardial infarction (MI) or vascular wire injury has not been elucidated. Methods and Results Here, using macrophage Ncor1 knockout mouse in combination with a mouse model of MI, we demonstrated that macrophage NCOR1 deficiency significantly reduced infarct size and improved cardiac function after MI. In addition, macrophage NCOR1 deficiency markedly inhibited neointimal hyperplasia and vascular remodeling in a mouse model of arterial wire injury. Inflammation and macrophage proliferation were substantially attenuated in hearts and arteries of macrophage Ncor1 knockout mice after MI and arterial wire injury, respectively. Cultured primary macrophages from macrophage Ncor1 knockout mice manifested lower expression of inflammatory genes upon stimulation by interleukin-1ß, interleukin-6, or lipopolysaccharide, together with much less activation of inflammatory signaling cascades including signal transducer and activator of transcription 1 and nuclear factor-κB. Furthermore, macrophage Ncor1 knockout macrophages were much less proliferative in culture, with inhibited cell cycle progression compared with control cells. Conclusions Collectively, our data have demonstrated that NCOR1 is a critical regulator of macrophage inflammation and proliferation and that deficiency of NCOR1 in macrophages attenuates MI and neointimal hyperplasia. Therefore, macrophage NCOR1 may serve as a potential therapeutic target for MI and restenosis.

Nuclear receptor corepressor 1 represses cardiac hypertrophy.

The function of nuclear receptor corepressor 1 (NCoR1) in cardiomyocytes is unclear, and its physiological and pathological implications are unknown. Here, we found that cardiomyocyte-specific NCoR1 knockout (CMNKO) mice manifested cardiac hypertrophy at baseline and had more severe cardiac hypertrophy and dysfunction after pressure overload. Knockdown of NCoR1 exacerbated whereas overexpression mitigated phenylephrine-induced cardiomyocyte hypertrophy. Mechanistic studies revealed that myocyte enhancer factor 2a (MEF2a) and MEF2d mediated the effects of NCoR1 on cardiomyocyte hypertrophy. The receptor interaction domains (RIDs) of NCoR1 interacted with MEF2a to repress its transcriptional activity. Furthermore, NCoR1 formed a complex with MEF2a and class IIa histone deacetylases (HDACs) to suppress hypertrophy-related genes. Finally, overexpression of RIDs of NCoR1 in the heart attenuated cardiac hypertrophy and dysfunction induced by pressure overload. In conclusion, NCoR1 cooperates with MEF2 and HDACs to repress cardiac hypertrophy. Targeting NCoR1 and the MEF2/HDACs complex may be an attractive therapeutic strategy to tackle pathological cardiac hypertrophy.