Guidelines for DC preparation and flow cytometry analysis of mouse nonlymphoid tissues.

This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs and various nonlymphoid tissues. DC are sentinels of the immune system present in almost every mammalian organ. Since they represent a rare cell population, DC need to be extracted from organs with protocols that are specifically developed for each tissue. This article provides detailed protocols for the preparation of single-cell suspensions from various mouse nonlymphoid tissues, including skin, intestine, lung, kidney, mammary glands, oral mucosa and transplantable tumors. Furthermore, our guidelines include comprehensive protocols for multiplex flow cytometry analysis of DC subsets and feature top tricks for their proper discrimination from other myeloid cells. With this collection, we provide guidelines for in-depth analysis of DC subsets that will advance our understanding of their respective roles in healthy and diseased tissues. While all protocols were written by experienced scientists who routinely use them in their work, this article was also peer-reviewed by leading experts and approved by all coauthors, making it an essential resource for basic and clinical DC immunologists.

π-Electron Fluctuation-Induced P+ /C- Ambiphilic Interaction for Intramolecular CAr -H Bond Activation.

Herein, we describe how computational mechanistic understanding has led directly to the discovery of new 2H-phosphindole for C-CAr bond activation and dearomatization reaction. We uncover an unexpected intramolecular C-H bond activation with a 2H-phosphindole derivative. This new intriguing experimental observation and further theoretical studies led to an extension of the reaction mechanism with 2H-phosphindole. Through DFT calculations, we confirm that within a five-membered ring, the polarizable PC3 unit orchestrates the formation of an electrophilic phosphorus atom (P+ ) and a nucleophilic carbon atom (C- ). This kinetically accessible ambiphilic phosphorus/carbon couple is spatially separated by geometric constraints, and their reactivity is modulated through structural resonance.

Endothelial cell death after ionizing radiation does not impair vascular structure in mouse tumor models.

The effect of radiation therapy on tumor vasculature has long been a subject of debate. Increased oxygenation and perfusion have been documented during radiation therapy. Conversely, apoptosis of endothelial cells in irradiated tumors has been proposed as a major contributor to tumor control. To examine these contradictions, we use multiphoton microscopy in two murine tumor models: MC38, a highly vascularized, and B16F10, a moderately vascularized model, grown in transgenic mice with tdTomato-labeled endothelium before and after a single (15 Gy) or fractionated (5 × 3 Gy) dose of radiation. Unexpectedly, even these high doses lead to little structural change of the perfused vasculature. Conversely, non-perfused vessels and blind ends are substantially impaired after radiation accompanied by apoptosis and reduced proliferation of their endothelium. RNAseq analysis of tumor endothelial cells confirms the modification of gene expression in apoptotic and cell cycle regulation pathways after irradiation. Therefore, we conclude that apoptosis of tumor endothelial cells after radiation does not impair vascular structure.

The neutrophil-to-apolipoprotein A1 ratio is associated with adverse outcomes in patients with acute decompensated heart failure at different glucose metabolic states: a retrospective cohort study.

BACKGROUND: The present study was performed to assess the association between the neutrophil-to-apolipoprotein A1 ratio (NAR) and outcomes in patients with acute decompensated heart failure (ADHF) at different glucose metabolism states. METHODS: We recruited 1233 patients with ADHF who were admitted to Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University from December 2014 to October 2019. The endpoints were defined as composites of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke and exacerbation of chronic heart failure. The restricted cubic spline was used to determine the best cutoff of NAR, and patients were divided into low and high NAR groups. Kaplan-Meier plots and multivariable Cox proportional hazard models were used to investigate the association between NAR and the risk of adverse outcomes. RESULTS: During the five-year follow-up period, the composite outcome occurred in 692 participants (56.1%). After adjusting for potential confounding factors, a higher NAR was associated with a higher incidence of composite outcomes in the total cohort (Model 1: HR = 1.42, 95% CI = 1.22-1.65, P<0.001; Model 2: HR = 1.29, 95% CI = 1.10-1.51, P = 0.002; Model 3: HR = 1.20, 95% CI = 1.01-1.42, P = 0.036). At different glucose metabolic states, a high NAR was associated with a high risk of composite outcomes in patients with diabetes mellitus (DM) (Model 1: HR = 1.54, 95% CI = 1.25-1.90, P<0.001; Model 2: HR = 1.40, 95% CI = 1.13-1.74, P = 0.002; Model 3: HR = 1.31, 95% CI = 1.04-1.66, P = 0.022), and the above association was not found in patients with prediabetes mellitus (Pre-DM) or normal glucose regulation (NGR) (both P>0.05). CONCLUSIONS: The NAR has predictive value for adverse outcomes of ADHF with DM, which implies that the NAR could be a potential indicator for the management of ADHF.

Refractory ventricular tachycardia and heart failure due to anti-mitochondrial antibody-positive inflammatory myopathy.

BACKGROUND: Anti-mitochondrial antibody (AMA)-positive inflammatory myopathy, a rare type of idiopathic inflammatory myopathy which was frequently difficult to diagnose, can affect muscles and the structure and electrical conduction of the heart. Early identification and treatment of this myopathy can prevent serious cardiovascular adverse events and improve cardiac function. CASE PRESENTATION: We report a patient who experienced repeated syncope, ventricular tachycardia (VT) and heart failure accompanied by weakness and muscle atrophy. He was initially diagnosed with dilated cardiomyopathy and received implantable cardioverter-defibrillator therapy. He was subsequently misdiagnosed as muscular dystrophy due to progressive muscular atrophy. However, the patient developed repeated and refractory VT storms that were not alleviated by conventional therapy. Finally, he was diagnosed with AMA-positive inflammatory myopathy with cardiac injuries. The patient was markedly recovered by being treated with immunosuppressive and immunomodulatory therapy. CONCLUSION: AMA could be screened when discovering myopathies accompanied by unexplained cardiac symptoms. Our findings provide insights into the diagnosis and therapy of this rare and severe disease.

A reduction of Syndecan-4 in macrophages promotes atherosclerosis by aggravating the proinflammatory capacity of macrophages.

BACKGROUND: Cardiovascular diseases (CVDs) are a significant cause of mortality worldwide and are characterized by severe atherosclerosis (AS) in patients. However, the molecular mechanism of AS formation remains elusive. In the present study, we investigated the role of syndecan-4 (SDC4), a member of the syndecan family, in atherogenesis. METHODS AND RESULTS: The expression of SDC4 decreased in mouse severe AS models. Moreover, knockout of SDC4 accelerated high-cholesterol diets (HCD)-induced AS in ApoE-/- mice. Mechanistically, the decrease of SDC4 increased macrophage proinflammatory capacity may be through the PKCα-ABCA1/ABCG1 signaling pathway. CONCLUSION: These findings provide evidence that SDC4 reduction links macrophages and inflammation to AS and that SDC4 in macrophages provides a therapeutic target for preventing AS formation.

Prognostic value of triglyceride glucose (TyG) index in patients with acute decompensated heart failure.

BACKGROUND: The triglyceride glucose (TyG) index has been proposed as a reliable marker of insulin resistance (IR) and an independent predictor of cardiovascular disease risk. However, its prognostic value in patients with acute decompensated heart failure (ADHF) remains unclear. METHODS: A total of 932 hospitalized patients with ADHF from January 1st, 2018 to February 1st, 2021 were included in this retrospective study. The TyG index was calculated as ln [fasting triglyceride level (mg/dL) × fasting plasma glucose level (mg/dL)/2]. Patients were divided into tertiles according to TyG index values. The primary endpoints were all-cause death, cardiovascular (CV) death and major adverse cardiac and cerebral events (MACCEs) during follow-up. We used multivariate adjusted Cox proportional hazard models and restricted cubic spline analysis to investigate the associations of the TyG index with primary endpoints. RESULTS: During a median follow-up time of 478 days, all-cause death, CV death and MACCEs occurred in 140 (15.0%), 103 (11.1%) and 443 (47.9%) cases, respectively. In multivariate Cox proportional hazard models, the risk of incident primary endpoints was associated with the highest TyG tertile. After adjustment for confounding factors, hazard ratios (HRs) for the highest tertile (TyG index ≥ 9.32) versus the lowest tertile (TyG index < 8.83) were 2.09 (95% confidence interval [CI], 1.23-3.55; p = 0.006) for all-cause death, 2.31 (95% CI, 1.26-4.24; p = 0.007) for CV death and 1.83 (95% CI, 1.18-3.01; p = 0.006) for MACCEs. Restricted cubic spline analysis also showed that the cumulative risk of primary endpoints increased as TyG index increased. When the TyG index was used as a continuous variable, the hazard ratios of the three primary endpoints rapidly increased within the higher range of the TyG index (all cause death, TyG > 9.08; CV death, TyG > 9.46; MACCEs, TyG > 9.87). CONCLUSIONS: The elevated TyG index was independently associated with poor prognosis, and thus would be useful in the risk stratification in patients with ADHF.

The association between fibrinogen-to-albumin ratio (FAR) and adverse prognosis in patients with acute decompensated heart failure at different glucose metabolic states.

BACKGROUND: Circulating fibrinogen-to-albumin ratio (FAR) has been proposed as a novel inflammatory biomarker and a cardiovascular disease risk predictor. However, its prognostic value in patients with acute decompensated heart failure (ADHF) and different glycemic metabolic states remains ambiguous. METHODS: A total of 1031 hospitalized patients with ADHF from January 2018 to May 2021 were included in the study. The primary endpoints were the major adverse cardiac and cerebral events (MACCEs). Patients were categorized into high-level FAR (FAR-H) and low-level FAR (FAR-L) groups based on the optimal cut-off value of FAR obtained from restricted cubic spline function analysis. The Kaplan-Meier plots and three multivariate-adjusted Cox proportional hazard models were used to determine the association between FAR and the risk of developing MACCEs in patients with ADHF at different glycemic metabolic states. RESULTS: MACCEs occurred in 483 (46.8%) patients during a median follow-up time of 520 days. The optimal FAR cut-off value was 0.079. Upon analyzing the Kaplan-Meier plots, the incidence of MACCEs was significantly different between the FAR groups in all patients and patients with diabetes mellitus (p < 0.05). After adjusting for the confounding factors, the hazard ratio (HR) for MACCEs in the FAR-H group was 1.29 compared with the FAR-L group in all patients (Model 3: 95% CI 1.07-1.56, p = 0.007). Additionally, high FAR was associated with MACCEs in three multivariate Cox models (Model 1, HR = 1.52, 95% CI 1.17-1.96, p = 0.002; Model 2, HR = 1.46, 95% CI 1.13-1.89, p = 0.004; Model 3, HR = 1.48, 95% CI 1.14-1.92, p = 0.003) in DM patients. But no significant differences were found between the FAR groups for prediabetes mellitus (Pre-DM) and normal glucose regulation (NGR) using the three Cox models (all p-values were > 0.05). CONCLUSIONS: Elevated FAR was independently associated with poor prognosis in patients with ADHF and DM and thus could be used as a risk stratification tool and a potential therapeutic target in the future.

Major vault protein attenuates cardiomyocyte injury in doxorubicin-induced cardiomyopathy through activating AKT.

BACKGROUND: Doxorubicin (DOX) has limited chemotherapy application for malignancies due to cardiotoxicity. The pathogenesis of DOX-induced cardiomyopathy (DiCM) is yet to be elucidated. Increasing studies proved that activation of AKT prevented cardiomyocyte apoptosis and cardiac dysfunction in response to DOX insult. Our previous studies indicated that major vault protein (MVP) deficiency was accompanied by suppressed phosphorylation of AKT in metabolic diseases. This study aimed to investigate the role and underlying mechanism of MVP on cardiomyocyte apoptosis in DiCM. METHODS: Mice were intraperitoneally injected with DOX 5 mg/kg, once a week for 5 weeks, the total cumulative dose was 25 mg/kg. Cardiomyocyte-specific MVP overexpression was achieved using an adeno-associated virus system under the cTnT promoter after the fourth DOX injection. Cardiac function was examined by echocardiography followed by euthanasia. Tissue and serum were collected for morphology analysis and biochemical examination. RESULTS: Herein, we found that MVP expression was upregulated in DOX-treated murine hearts. Cardiac-specific MVP overexpression alleviated DOX-induced cardiac dysfunction, oxidative stress and fibrosis. Mechanistically, MVP overexpression activated AKT signaling and decreased cardiomyocyte apoptosis in DiCM. CONCLUSIONS: Based on these findings, we supposed that MVP was a potential therapeutic agent against DiCM.

Percutaneous intravenous catheter forceps biopsy in right atrial mass: two case reports and literature review.

BACKGROUND: Primary malignant tumors of the heart are rare. Although preoperative histological diagnosis is difficult, it has paramount value in therapeutic strategy development and prognostic estimation. Herein, we reported 2 cases of intracardiac tumors. CASES PRESENTATION: Both patients presented to the hospital with heart-related symptoms. Echocardiography showed massive masses in the atrium and positron emission tomography-computed tomography (PET/CT) revealed hypermetabolism and invasiveness. One patient cannot take surgery due to extensive metastasis and poor condition. The other patient was primarily diagnosed with lymphoma, and surgery was not recommended. They successfully underwent intravenous atrial biopsy, and histological samples confirmed intimal sarcoma and diffuse large B cell lymphoma. Based on immunohistochemical and molecular assessments, targeted chemotherapy was administered, resulting in clinical and imaging remission at discharge. CONCLUSIONS: Percutaneous intravenous catheter biopsy as a safe invasive test provides an accurate pathological diagnosis after imaging evaluation, and offers a therapeutic direction. Nonmalignant masses and some chemo-radiosensitive malignant tumors in the atrium could have good prognosis after targeted therapy.

Effect of different free-range systems on the growth performance, carcass traits, and meat quality of Yangzhou geese.

This study was conducted to investigate the effects of different free-range systems on the growth performance, carcass traits, and meat quality of geese. Grass pasture zones in the study area were selected, and 28 d-old male Yangzhou geese with similar body weights (1.57 ± 0.12 kg) were randomly allocated to one of three conditions: (A) free-range conditions in the apron area during 9:00 a.m.-4:00 p.m. (10-20 m from shed with grass pasture); (B) free-range conditions in the outer range from 9:00 a.m. to 4:00 p.m. (beyond 50 m from shed with grass pasture); and (C) barn system. Free range-reared geese had higher weight gain after 42 days of age than barn-reared geese, regardless of the range area. A lower feed conversion ratio was found in outer range-reared and apron area-reared geese from 28 to 63 days of age. In addition, the highest percentages of leg and breast muscle weights were observed in outer range-reared and apron area-reared geese, respectively. Finally, outer-range rearing resulted in a lower pH and lower moisture content. Therefore, these data suggest that the outer range system benefits growth performance and feed conversion ratio of geese and results in a higher percentage of leg muscle weight, lower pH, and lower moisture content.

Deletion of the deISGylating enzyme USP18 enhances tumour cell antigenicity and radiosensitivity.

BACKGROUND: Interferon (IFN) signalling pathways, a key element of the innate immune response, contribute to resistance to conventional chemotherapy, radiotherapy, and immunotherapy, and are often deregulated in cancer. The deubiquitylating enzyme USP18 is a major negative regulator of the IFN signalling cascade and is the predominant human protease that cleaves ISG15, a ubiquitin-like protein tightly regulated in the context of innate immunity, from its modified substrate proteins in vivo. METHODS: In this study, using advanced proteomic techniques, we have significantly expanded the USP18-dependent ISGylome and proteome in a chronic myeloid leukaemia (CML)-derived cell line. USP18-dependent effects were explored further in CML and colorectal carcinoma cellular models. RESULTS: Novel ISGylation targets were characterised that modulate the sensing of innate ligands, antigen presentation and secretion of cytokines. Consequently, CML USP18-deficient cells are more antigenic, driving increased activation of cytotoxic T lymphocytes (CTLs) and are more susceptible to irradiation. CONCLUSIONS: Our results provide strong evidence for USP18 in regulating antigenicity and radiosensitivity, highlighting its potential as a cancer target.

Index of microcirculatory resistance predicts long term cardiac systolic function in patients with STEMI undergoing primary PCI.

BACKGROUND: To evaluate the predictive value of the index of microcirculatory resistance (IMR) for long-term cardiac systolic function after primary percutaneous coronary intervention (pPCI) in patients with acute anterior wall ST-segment elevation myocardial infarction (STEMI). METHODS: A total of 53 acute anterior wall STEMI patients were included and followed up within 1-year. IMR was measured to evaluate the immediate intraoperative reperfusion. IMR > 40 U was defined as the high IMR group and ≤ 40 U was defined as the low IMR group. Left ventricular ejection fraction (LVEF) was measured by echocardiography at 24 h, 1 month, 3 months, and 1 year after PCI to analyze the correlation between IMR and cardiac systolic function. Heart failure was estimated according to classification within one year. RESULTS: The ratio of TMPG (TIMI myocardial perfusion grade) 3 (85.7% vs. 52%, p = 0.015) and STR (ST-segment resolution) > 70% (82.1% vs. 48%, p = 0.019) were significantly higher in the low IMR group. The LVEF in the low IMR group was significantly higher than that in the high IMR group at 3 months (43.06 ± 2.63% vs. 40.20 ± 2.67%, p < 0.001) and 1 year (44.16 ± 2.40% vs. 40.13 ± 3.48%, p < 0.001). IMR was negatively correlated with LVEF at 3 months (r = - 0.1014, p = 0.0040) and 1 year (r = - 0.1754, p < 0.0001). CONCLUSIONS: The IMR showed significant negative correlation with the LVEF value after primary PCI. The high IMR is a strong predictor of heart failure within 1 year after anterior myocardial infarction.

The diagnostic capability of electrocardiography on the cardiogenic shock in the patients with acute myocarditis.

BACKGROUND: The study was performed to assess the diagnostic capability of ECG on the cardiogenic shock (CS) in acute myocarditis. A new score was derived from the combination of the ECG parameters and the diagnostic value was also evaluated. METHODS: Total 103 consecutive patients with acute myocarditis admitted in Nanjing Drum Hospital were enrolled in the current study. The cohort was divided into fulminant myocarditis group (FM, n = 20) and non fulminant myocarditis group (NFM, n = 83). The demographic features, results of electrocardiography (ECG) and ultracardiography were compared. Logistic regression analysis was conducted to identify the relevant factors in ECG parameters. We created a new variable called "ECG score" by certain combination of ECG parameters. The diagnostic capability of ECG score for CS was compared with the existing diagnostic indices using regression model and receiver-operating characteristics (ROC) analysis. RESULTS: There were several changes on ECG significantly different between the two groups. Multivariate regression analysis demonstrated PR + QRS interval (P = 0.008), ventricular arrhythmia (P = 0.001) and pathological Q wave (P = 0.003) were the independent relevant factors of CS. The derived variable "ECG score" was identified as a significant relevant factor of CS by multivariate regression model. ROC analysis showed PR + QRS interval, ventricular arrhythmia and pathological Q wave all had equivalent diagnostic capability to left ventricular ejection fraction (LVEF) and shock index (SI). ECG score was equivalent to LVEF but superior to SI in diagnosing CS CONCLUSIONS: ECG was valuable in diagnosing CS due to acute myocarditis. The ECG score was superior to the traditional diagnostic indices and could be used for an rapid recognition of CS.

High Mobility Group B-1 (HMGB-1) Promotes Apoptosis of Macrophage-Derived Foam Cells by Inducing Endoplasmic Reticulum Stress.

BACKGROUND/AIMS: High mobility group B-1 (HMGB-1)-induced endoplasmic reticulum stress (ERS) has been implicated in inflammation and dendritic cell maturation. C/EBP-homologous protein (CHOP) is a vital component of ERS and apoptosis and plays a critical role in atherosclerosis. However, only a little information is available about the role of HMGB-1 in foam cell formation. Thus, the role of HMGB-1-induced ERS/CHOP pathway in apoptosis and formation of macrophage-derived foam cells is investigated. METHODS: RAW264.7 cells were treated with oxidized low-density lipoprotein (oxLDL) in the absence and/or presence of HMGB-1, N-acetylcysteine (NAC, an antioxidant), glycyrrhizin (Gly, an HMGB-1 inhibitor), tunicamycin (TM, an ERS inducer), and 4-phenylbutyrate (4-PBA, an ERS inhibitor). Reactive oxygen species (ROS) production was examined by dihydroethidium (DHE) staining. Oil Red O staining, intracellular total cholesterol assay, and Dil-oxLDL uptake assay evaluated the accumulation of lipids in macrophages. Cell apoptosis was measured by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Western blot detected the expression of HMGB-1/ERS/CHOP pathway. RESULTS: oxLDL induced HMGB-1 translocation and secretion in a dose- and time-dependent manner, which was inhibited by NAC. oxLDL-induced lipid accumulation in macrophages was promoted synergistically by HMGB-1 that was attenuated by Gly. Moreover, TM synergized with oxLDL induced lipid accumulation and apoptosis of macrophages; however, 4-PBA alleviated the oxLDL-induced apoptotic foam cells. Additionally, the inhibition of ERS with 4-PBA suppressed the expression of HMGB-1-induced CHOP. CONCLUSIONS: OxLDL triggered HMGB-1 secretion in macrophages via oxidative stress. Furthermore, HMGB-1 promoted the formation and apoptosis of macrophage-derived foam cells via activation of ERS/CHOP pathway.

Advanced Glycation Endproducts Impair Endothelial Progenitor Cell Migration and Homing via Syndecan 4 Shedding.

Endothelial progenitor cells (EPCs) are a subtype of bone marrow-derived progenitor cells. Stromal cell-derived factor 1 (SDF-1)-mediated EPC mobilization from bone marrow to areas of ischemia plays an important role in angiogenesis. Previous studies have reported that advanced glycation endproducts (AGEs), which are important mediators of diabetes-related vascular pathology, may impair EPC migration and homing, but the mechanism is unclear. Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan receptor on the cell surface, involved in SDF-1-dependent cell migration. The extracellular domain of synd4 (ext-synd4) is shed in the context of acute inflammation, but the shedding of ext-synd4 in response to AGEs is undefined. Here we investigated changes in ext-synd4 on EPCs in response to AGEs, focusing on the influence of impaired synd4 signaling on EPC migration and homing. We found decreased full length and increased residue of synd4 in cells incubated with AGEs, with concomitant increase in the soluble fragment of ext-synd4 in the cell medium. EPCs from patients with type 2 diabetes expressed less ext-synd4 as assessed by Western blotting. Flow cytometry analysis showed less ext-synd4 on circulating CD34+ peripheral blood mononuclear cells, of which EPCs form a subgroup. We then explored the role of synd4 in EPC migration and homing. Impaired migration of synd4-deficient EPCs was observed by a 2D-chemotaxis slide. Furthermore, poor homing of synd4-/- EPCs was observed in a mouse model of lower limb ischemia. This study demonstrates that the shedding of synd4 from EPCs plays a key role in AGE-mediated dysfunction of EPC migration and homing. Stem Cells 2017;35:522-531.

Synthesis of magnetic cytosine-imprinted chitosan nanoparticles.

Molecularly imprinted polymer nanoparticles incorporating magnetic nanoparticles (MNPs) have been investigated for their selective adsorption properties. Here we describe the synthesis and characterization of magnetic cytosine-imprinted chitosan nanoparticles (CIPs) for gene delivery. In particular, CIPs carrying the mammalian expression plasmid of enhanced green fluorescent protein were prepared by the co-precipitation of MNPs, chitosan and a template nucleobase (cytosine). The results show that the selective reabsorption of cytosine to magnetic CIPs was at least double that of non-imprinted polymers and other nucleobases (such as adenine and thymine). The gene carrier CIPs were used for the transfection of human embryonic kidney 293 cells showing dramatic increase their efficiency with that of conventional chitosan nanoparticles. Furthermore, the gene carrier magnetic CIPs also exhibit low toxicity compared to that of commercially available cationic lipids.

Syndecan-4 Signaling Is Required for Exercise-Induced Cardiac Hypertrophy.

Cardiac hypertrophy can be broadly classified as either physiological or pathological. Physiological stimuli such as exercise cause adaptive cardiac hypertrophy and normal heart function. Pathological stimuli including hypertension and aortic valvular stenosis cause maladaptive cardiac remodeling and ultimately heart failure. Syndecan-4 (synd4) is a transmembrane proteoglycan identified as being involved in cardiac adaptation after injury, but whether it takes part in physiological cardiac hypertrophy is unclear. We observed upregulation of synd4 in exercise-induced hypertrophic myocardium. To evaluate the role of synd4 in the physiological form of cardiac hypertrophy, mice lacking synd4 (synd4-/-) were exercised by swimming for 4 wks. Ultrasonic cardiogram (UCG) and histological analysis revealed that swimming induced the hypertrophic phenotype but was blunted in synd4-/- compared with wild-type (WT) mice. The swimming-induced activation of Akt, a key molecule in physiological hypertrophy was also more decreased than in WT controls. In cultured cardiomyocytes, synd4 overexpression could induce cell enlargement, protein synthesis and distinct physiological molecular alternation. Akt activation also was observed in synd4-overexpressed cardiomyocytes. Furthermore, inhibition of protein kinase C (PKC) prevented the synd4-induced hypertrophic phenotype and Akt phosphorylation. This study identified an essential role of synd4 in mediation of physiological cardiac hypertrophy.

Syndecan-4 shedding impairs macrovascular angiogenesis in diabetes mellitus.

PURPOSE: Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan cell surface receptor that modulates cell proliferation, migration, mechanotransduction, and endocytosis. The extracellular domain of synd4 sheds heavily in acute inflammation, but the shedding of synd4 in chronic inflammation, such as diabetes mellitus (DM), is still undefined. We investigated the alterations of synd4 endothelial expression in DM and the influence of impaired synd4 signaling on angiogenesis in human umbilical vein endothelial cells (HUVECs), diabetic rats, synd4 null mice, and db/db mice. MATERIAL AND METHODS: HUVECs were incubated with advanced glycation end products (AGEs). Western blot analysis was used to determine synd4 protein expression and ELISA was used to detect soluble synd4 fragments. The concentration of synd4 in the aortic endothelia of diabetic rats was detected by immunohistochemical staining. Aortic ring assays were performed to study the process of angiogenesis in the diabetic rats and in synd4 null and db/db mice. Recombinant adenoviruses containing the synd4 gene or null were constructed to enhance synd4 aortic expression in db/db mice. RESULTS: Western blot analysis showed decreased expression of the synd4 extracellular domain in HUVECs, and ELISA detected increased soluble fragments of synd4 in the media. Synd4 endothelial expression in the aortas of diabetic rats was decreased. Aortic ring assay indicated impaired angiogenesis in synd4 null and db/db mice, which was partially reversed by synd4 overexpression in db/db mice. CONCLUSION: Synd4 shedding from vascular endothelial cells played an important role in the diabetes-related impairment of angiogenesis.

Resveratrol ameliorates myocardial fibrosis by inhibiting ROS/ERK/TGF-ß/periostin pathway in STZ-induced diabetic mice.

BACKGROUND: Myocardial fibrosis is an essential hallmark of diabetic cardiomyopathy (DCM) contributing to cardiac dysfunctions. Resveratrol, an antioxidant, exerts its anti-fibrotic effect via inhibition of oxidative stress, while the underlying molecular mechanism remains largely elusive. Periostin, a fibrogenesis matricellular protein, has been shown to be associated with oxidative stress. In the present study, we investigated the role of periostin in anti-fibrotic effect of resveratrol in streptozocin (STZ)-induced diabetic heart and the underlying mechanisms. METHODS: Diabetic mice were induced by STZ injection. After treatment with resveratrol (5 or 25 mg/kg/day i.g) or Saline containing 0.5% carboxymethyl cellulose (CMC) for 2 months, the hearts were detected for oxidative stress and cardiac fibrosis using western blot, Masson's trichrome staining and Dihydroethidium (DHE) staining. In in vitro experiments, proliferation and differentiation of fibroblasts under different conditions were investigated through western blot, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay and immunofluorescence staining. RESULTS: Administration of resveratrol significantly mitigated oxidative level, interstitial fibrosis and expressions of related proteins in STZ-induced diabetic hearts. In in vitro experiments, resveratrol exhibited anti-proliferative effect on primary mouse cardiac fibroblasts via inhibiting reactive oxygen species (ROS)/extracellular regulated kinase (ERK) pathway and ameliorated myofibroblast differentiation via suppressing ROS/ERK/ transforming growth factor ß (TGF-ß)/periostin pathway. CONCLUSION: Increased ROS production, activation of ERK/TGF-ß/periostin pathway and myocardial fibrosis are important events in DCM. Alleviated ROS genesis by resveratrol prevents myocardial fibrosis by regulating periostin related signaling pathway. Thus, inhibition of ROS/periostin may represent a novel approach for resveratrol to reverse fibrosis in DCM.