Vascular permeability in cardiovascular disease and cancer. Curr Opin Hematol. 2008;15:243-249. [PMID: 18391792 DOI: 10.1097/moh.0b013e3282f97d86]

Cardiac-targeted and ROS-responsive liposomes containing puerarin for attenuating myocardial ischemia-reperfusion injury

Aim: This study aimed to construct an ischemic cardiomyocyte-targeted and ROS-responsive drug release system to reduce myocardial ischemia-reperfusion injury (MI/RI).Methods: We constructed thioketal (TK) and cardiac homing peptide (CHP) dual-modified liposomes loaded with puerarin (PUE@TK/CHP-L), which were expected to deliver drugs precisely into ischemic cardiomyocytes and release drugs in response to the presence of high intracellular ROS levels. The advantages of PUE@TK/CHP-L were assessed by cellular pharmacodynamics, in vivo fluorescence imaging and animal pharmacodynamics.Results: PUE@TK/CHP-L significantly inhibited apoptosis and ferroptosis in H/R-injured cardiomyocytes and also actively targeted ischemic myocardium. Based on these advantages, PUE@TK/CHP-L could significantly enhance the drug's ability to attenuate MI/RI.Conclusion: PUE@TK/CHP-L had potential clinical value in the precise treatment of MI/RI.

Pharmacogenomics-based systematic review of coronary artery disease based on personalized medicine procedure

Background

Coronary artery disease (CAD) is the most common reason for mortality and disability-adjusted life years (DALYs) lost globally. This study aimed to suggest a new gene list for the treatment of CAD by a systematic review of bioinformatics analyses of pharmacogenomics impacts of potential genes and variants.

Methods

PubMed search was filtered by the title including Coronary Artery Disease during 2020-2023. To find the genes with pharmacogenetic impact on the CAD, additional filtrations were considered according to the variant annotations. Protein-Protein Interactions (PPIs), Gene-miRNA Interactions (GMIs), Protein-Drug Interactions (PDIs), and variant annotation assessments (VAAs) performed by STRING-MODEL (ver. 12), Cytoscape (ver. 3.10), miRTargetLink.2., NetworkAnalyst (ver 0.3.0), and PharmGKB.

Results

Results revealed 5618 publications, 1290 papers were qualified, and finally, 650 papers were included. 4608 protein-coding genes were extracted, among them, 1432 unique genes were distinguished and 530 evidence-based repeated genes remained. 71 genes showed a pharmacogenetics-related variant annotation in at least (entirely 6331 annotations). Variant annotation assessment (VAA) showed 532 potential variants for the final report, and finally, the concluding PGs list represented 175 variants. Based on the function and MAF, 57 nonsynonymous variants of 29 Pharmacogenomics-related genes were associated with CAD.

Conclusion

Conclusively, evaluating circulating miR33a in individuals' plasma with CAD, and genotyping of rs2230806, rs2230808, rs2487032, rs12003906, rs2472507, rs2515629, and rs4149297 (ABCA1 variants) lead to precisely prescribing of well-known drugs. Also, the findings of this review can be used in both whole-genome sequencing (WGS) and whole-exome sequencing (WES) analysis in the prognosis and diagnosis of CAD.

Hydrogen sulfide improves endothelial barrier function by modulating the ubiquitination degradation of KLF4 through TRAF7 S-sulfhydration in diabetic aorta

Anomalous vascular endothelium significantly contributes to various cardiovascular diseases. VE-cadherin plays a vital role in governing the endothelial barrier. Krüppel-like factor 4(KLF4), as a transcription factor, which binds the VE-cadherin promoter and enhances its transcription. Tumor necrosis factor receptor-associated factor 7 (TRAF7) is an E3 ubiquitin ligase that has been shown to modulate the degradation of KLF4. H2S can covalently modify cysteine residues on proteins through S-sulfhydration, thereby influencing the structure and functionality of the target protein. However, the role of S-sulfhydration on endothelial barrier integrity remains to be comprehensively elucidated. This study aims to investigate whether protein S-sulfhydration in the endothelium regulates endothelial integrity and its underlying mechanism. In this study, we observed that protein S-sulfhydration was reduced in the endothelium during diabetes and TRAF7 was the main target. Overexpression of TRAF7-Cys327 mutant could mitigate the endothelial barrier damage by weakening TRAF7 interaction with KLF4 and reducing ubiquitination degradation of KLF4. In conclusion, our research demonstrates that H2S plays a pivotal role in regulating S-sulfhydration of TRAF7 at Cys327. This regulation effectively inhibits the ubiquitin-mediated degradation of KLF4, resulting in an upregulation of VE-cadherin levels. This molecular mechanism contributes to the prevention of endothelial barrier damage.

Evaluation of Vascular Permeability in Inflamed Vessels of the Cremaster Muscle in Live Mice

Inflammation in vascular structures due to external factors such as injury or infection inevitably leads to blood leakage. Therefore, measuring blood infiltrated into tissue may serve as an indication for the extent of an inflammatory reaction or injury. There are various methods of confirming vascular permeability in vivo and in vitro; for example, using a blood vessel permeable dye, the dye efflux can be quantitatively measured with a spectrophotometer. Although the aforementioned commonly used methods can measure leaked dye without difficulty, substantial limitations exist regarding the time points of blood leakage that can be measured. Here, we describe the details of a novel protocol to identify and analyze the real-time progression of blood leakage in vivo. This method, by combining existing methods with real-time imaging, is expected to immensely improve the visualization and evaluation of vascular permeability.

Vascular Endothelial Barrier Protection Prevents Atrial Fibrillation by Preserving Cardiac Nanostructure

BACKGROUND

Atrial fibrillation (AF), the most common cardiac arrhythmia, is widely associated with inflammation, vascular dysfunction, and elevated levels of the vascular leak-inducing cytokine, vascular endothelial growth factor (VEGF). Mechanisms underlying AF are poorly understood and current treatments only manage this progressive disease, rather than arresting the underlying pathology. The authors previously identified edema-induced disruption of sodium channel (NaV1.5)-rich intercalated disk nanodomains as a novel mechanism for AF initiation secondary to acute inflammation. Therefore, we hypothesized that protecting the vascular barrier can prevent vascular leak-induced atrial arrhythmias.

OBJECTIVES

In this study the authors tested the hypothesis that protecting the vascular barrier can prevent vascular leak-induced atrial arrhythmias. They identified 2 molecular targets for vascular barrier protection, connexin43 (Cx43) hemichannels and pannexin-1 (Panx1) channels, which have been implicated in cytokine-induced vascular leak.

METHODS

The authors undertook in vivo electrocardiography, electron microscopy, and super-resolution light microscopy studies in mice acutely treated with a clinically relevant level of VEGF.

RESULTS

AF incidence was increased in untreated mice exposed to VEGF relative to vehicle control subjects. VEGF also increased the average number of AF episodes. VEGF shifted NaV1.5 signal to longer distances from Cx43 gap junctions, measured by a distance transformation-based spatial analysis of 3-dimensional confocal images of intercalated disks. Similar effects were observed with NaV1.5 localized near mechanical junctions composed of neural cadherin. Blocking connexin43 hemichannels (αCT11 peptide) or Panx1 channels (PxIL2P peptide) significantly reduced the duration of AF episodes compared with VEGF alone with no treatment. Concurrently, both peptide therapies preserved NaV1.5 distance from gap junctions to control levels and reduced mechanical junction-adjacent intermembrane distance in these hearts. Notably, similar antiarrhythmic efficacy was also achieved with clinically-relevant small-molecule inhibitors of Cx43 and Panx1.

CONCLUSIONS

These results highlight vascular barrier protection as an antiarrhythmic strategy following inflammation-induced vascular leak.

High Serum VE-Cadherin and Vinculin Concentrations Are Markers of the Disruption of Vascular Integrity during Type B Acute Aortic Dissection

BACKGROUND

In the present study, we measured the serum vascular endothelial cadherin (VEC) and vinculin (Vcn) concentrations in patients with type B acute aortic dissection (TBAD) to evaluate their diagnostic value for this condition.

METHODS

A total of 100 patients with TBAD and 90 matched controls were included in the study. The serum concentrations of VEC and Vcn were measured using enzyme-linked immunosorbent assays.

RESULTS

The serum VEC and Vcn concentrations were significantly higher in participants with TBAD than in healthy controls. Compared with patients with acute myocardial infarction (AMI), the serum concentrations of VEC and Vcn in patients with TBAD were higher, and the Vcn showed significant difference, with statistical significance. Receiver operating characteristic analysis generated areas under the curves for VEC and Vcn that were diagnostic for TBAD (0.599 and 0.655, respectively). The optimal cut-off values were 3.975 ng/μL and 128.1 pg/mL, the sensitivities were 43.0% and 35.0%, and the specificities were 73.3% and 90.0%, respectively. In addition, the use of a combination of serum VEC and Vcn increased the AUC to 0.661, with a sensitivity of 33.0% and a specificity of 93.33%. A high serum Vcn concentration was associated with a higher risk of visceral malperfusion in participants with TBAD (odds ratio (OR) = 1.007, 95% confidence interval [CI]: 1.001-1.013, p = 0.014). In participants with refractory pain, the adjusted OR for the serum VEC concentration increased to 1.172 (95% CI: 1.010-1.361; p = 0.036), compared with participants without refractory pain.

CONCLUSION

This study is the first to show the diagnostic value of serum VEC and Vcn for AAD and their relationships with the clinical characteristics of patients with TBAD. Thus, VEC and Vcn are potential serum markers of TBAD.

Role of G-protein coupled receptors in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death globally, with CVDs accounting for nearly 30% of deaths worldwide each year. G-protein-coupled receptors (GPCRs) are the most prominent family of receptors on the cell surface, and play an essential regulating cellular physiology and pathology. Some GPCR antagonists, such as β-blockers, are standard therapy for the treatment of CVDs. In addition, nearly one-third of the drugs used to treat CVDs target GPCRs. All the evidence demonstrates the crucial role of GPCRs in CVDs. Over the past decades, studies on the structure and function of GPCRs have identified many targets for the treatment of CVDs. In this review, we summarize and discuss the role of GPCRs in the function of the cardiovascular system from both vascular and heart perspectives, then analyze the complex ways in which multiple GPCRs exert regulatory functions in vascular and heart diseases. We hope to provide new ideas for the treatment of CVDs and the development of novel drugs.

Review on the protective mechanism of astragaloside IV against cardiovascular diseases

Cardiovascular disease is a global health problem. Astragaloside IV (AS-IV) is a saponin compound extracted from the roots of the Chinese herb Astragalus. Over the past few decades, AS-IV has been shown to possess various pharmacological properties. It can protect the myocardium through antioxidative stress, anti-inflammatory effects, regulation of calcium homeostasis, improvement of myocardial energy metabolism, anti-apoptosis, anti-cardiomyocyte hypertrophy, anti-myocardial fibrosis, regulation of myocardial autophagy, and improvement of myocardial microcirculation. AS-IV exerts protective effects on blood vessels. For example, it can protect vascular endothelial cells through antioxidative stress and anti-inflammatory pathways, relax blood vessels, stabilize atherosclerotic plaques, and inhibit the proliferation and migration of vascular smooth muscle cells. Thus, the bioavailability of AS-IV is low. Toxicology indicates that AS-IV is safe, but should be used cautiously in pregnant women. In this paper, we review the mechanisms of AS-IV prevention and treatment of cardiovascular diseases in recent years to provide a reference for future research and drug development.

Pro-inflammatory role of Wnt/β-catenin signaling in endothelial dysfunction

Background

Endothelial dysfunction is a critical component of both atherosclerotic plaque formation and saphenous vein graft failure. Crosstalk between the pro-inflammatory TNF-α-NFκB signaling axis and the canonical Wnt/β-catenin signaling pathway potentially plays an important role in regulating endothelial dysfunction, though the exact nature of this is not defined.

Results

In this study, cultured endothelial cells were challenged with TNF-α and the potential of a Wnt/β-catenin signaling inhibitor, iCRT-14, in reversing the adverse effects of TNF-α on endothelial physiology was evaluated. Treatment with iCRT-14 lowered nuclear and total NFκB protein levels, as well as expression of NFκB target genes, IL-8 and MCP-1. Inhibition of β-catenin activity with iCRT-14 suppressed TNF-α-induced monocyte adhesion and decreased VCAM-1 protein levels. Treatment with iCRT-14 also restored endothelial barrier function and increased levels of ZO-1 and focal adhesion-associated phospho-paxillin (Tyr118). Interestingly, inhibition of β-catenin with iCRT-14 enhanced platelet adhesion in cultured TNF-α-stimulated endothelial cells and in an ex vivo human saphenous vein model, most likely via elevating levels of membrane-tethered vWF. Wound healing was moderately retarded by iCRT-14; hence, inhibition of Wnt/β-catenin signaling may interfere with re-endothelialisation in grafted saphenous vein conduits.

Conclusion

Inhibition of the Wnt/β-catenin signaling pathway with iCRT-14 significantly recovered normal endothelial function by decreasing inflammatory cytokine production, monocyte adhesion and endothelial permeability. However, treatment of cultured endothelial cells with iCRT-14 also exerted a pro-coagulatory and moderate anti-wound healing effect: these factors may affect the suitability of Wnt/β-catenin inhibition as a therapy for atherosclerosis and vein graft failure.

Impact of the failure of initial insertion of a peripheral intravascular catheter on the development of adverse events in patients admitted to the intensive care unit from the emergency room: A post hoc analysis of the AMOR-VENUS study

Aim

To investigate an association between failure of initial peripheral intravascular catheter (PIVC) insertion and adverse events in patients admitted to the intensive care unit (ICU) from the emergency room (ER).

Methods

This study was a post hoc analysis of the AMOR-VENUS study, a multicenter cohort study that included 22 institutions and 23 ICUs in Japan between January and March of 2018. Study participants included consecutive adult patients admitted to the ICU with PIVCs inserted in ICU during the study period exclusively from the ER. The primary outcome was adverse events. Adverse events were composite of arterial puncture, hematoma, extravasation, nerve injury, tendon injury, compartment syndrome, pain, redness, bad location, and effusion. Multivariate logistic regression analyses were performed to assess the association between adverse events and the failure of initial PIVC insertion.

Results

In total, 363 patients and 1121 PIVCs were analyzed. Moreover, 199 catheters failed to insert properly, and 36 patients and 107 catheters experienced adverse events. After performing multivariate logistic regression analysis, there were statistically significant associations in the odds ratio (OR) and 95% confidence interval (CI) for the failure of initial insertion (OR, 1.66 [1.02-2.71]; p = 0.04).

Conclusion

Failure of initial insertion may be a risk factor for adverse events. We could potentially provide various interventions to avoid failure of initial PIVC insertion. For example, PIVC insertion could be performed by experienced practitioners.

Lack of adducin impairs the stability of endothelial adherens and tight junctions and may be required for cAMP-Rac1-mediated endothelial barrier stabilization

Adducin (Add) is an actin binding protein participating in the stabilization of actin/spectrin networks, epithelial junctional turnover and cardiovascular disorders such as hypertension. Recently, we demonstrated that Add is required for adherens junctions (AJ) integrity. Here we hypothesized that Add regulates tight junctions (TJ) as well and may play a role in cAMP-mediated barrier enhancement. We evaluated the role of Add in MyEnd cells isolated from WT and Add-Knock-Out (KO) mice. Our results indicate that the lack of Add drastically alters the junctional localization and protein levels of major AJ and TJ components, including VE-Cadherin and claudin-5. We also showed that cAMP signaling induced by treatment with forskolin and rolipram (F/R) enhances the barrier integrity of WT but not Add-KO cells. The latter showed no junctional reorganization upon cAMP increase. The absence of Add also led to higher protein levels of the small GTPases Rac1 and RhoA. In vehicle-treated cells the activation level of Rac1 did not differ significantly when WT and Add-KO cells were compared. However, the lack of Add led to increased activity of RhoA. Moreover, F/R treatment triggered Rac1 activation only in WT cells. The function of Rac1 and RhoA per se was unaffected by the total ablation of Add, since direct activation with CN04 was still possible in both cell lines and led to improved endothelial barrier function. In the current study, we demonstrate that Add is required for the maintenance of endothelial barrier by regulating both AJ and TJ. Our data show that Add may act upstream of Rac1 as it is necessary for its activation via cAMP.

Implication of IGF1R signaling in the protective effect of Astragaloside IV on ischemia and reperfusion-induced cardiac microvascular endothelial hyperpermeability

BACKGROUND

Myocardial ischemia-reperfusion (I/R) causes damage to coronary capillary endothelial barrier and microvascular leakage (MVL), aggravating tissue injury and heart dysfunction. However, the effective strategy for protecting endothelium barrier of cardiac vasculature remains limited.

PURPOSE

This study aimed to explore the effect of Astragaloside IV (ASIV) on coronary MVL after cardiac I/R and the underlying mechanism.

STUDY DESIGN

Sprague-Dawley (SD) rats were used for assessment of the efficacy of Astragaloside IV in protection of myocardial I/R injury, while human cardiac microvascular endothelial cells were applied to gain more insight into the underlying mechanism.

METHODS

Sprague-Dawley rats with or without pretreatment by ASIV at 10 mg/kg were subjected to occlusion of left coronary anterior descending artery followed by reperfusion. Endothelial cells were exposed to hypoxia and re-oxygenation (H/R). The distribution of junction proteins was detected by immunofluorescence staining and confocal microscope, the content of junction proteins was detected by Western blot, the level of adenosine triphosphate (ATP) was detected by ELISA, and the signal pathway related to permeability was detected by siRNA infection. The fluorescence intensity of FITC-albumin and FITC-Dextran was measured to evaluate the permeability of endothelial cells.

RESULTS

ASIV exhibited protective effects on capillary damage, myocardium edema, albumin leakage, leucocyte infiltration, and the downregulated expression of endothelial junction proteins after I/R. Moreover, ASIV displayed ability to protect ATP from depletion after I/R or H/R, and the effect of ASIV on regulating vascular permeability and junction proteins was abolished once ATP synthase was inhibited. Notably, ASIV activated the insulin-like growth factor 1 receptor (IGF1R) and downstream signaling after reoxygenation. Knocking IGF1R down abolished the effect of ASIV on restoration of ATP, junction proteins and endothelial barrier after H/R.

CONCLUSION

ASIV was potential to prevent MVL after I/R in heart. Moreover, the study for the first time demonstrated that the beneficial role of ASIV depended on promoting production of ATP through activating IGF1R signaling pathway. This result provided novel insight for better understanding the mechanism underlying the potential of ASIV to cope with cardiac I/R injury.

Pathogenesis of Multiple Organ Failure: The Impact of Systemic Damage to Plasma Membranes

Multiple organ failure (MOF) is the major cause of morbidity and mortality in intensive care patients, but the mechanisms causing this severe syndrome are still poorly understood. Inflammatory response, tissue hypoxia, immune and cellular metabolic dysregulations, and endothelial and microvascular dysfunction are the main features of MOF, but the exact mechanisms leading to MOF are still unclear. Recent progress in the membrane research suggests that cellular plasma membranes play an important role in key functions of diverse organs. Exploration of mechanisms contributing to plasma membrane damage and repair suggest that these processes can be the missing link in the development of MOF. Elevated levels of extracellular phospholipases, reactive oxygen and nitrogen species, pore-forming proteins (PFPs), and dysregulation of osmotic homeostasis occurring upon systemic inflammatory response are the major extracellular inducers of plasma membrane damage, which may simultaneously operate in different organs causing their profound dysfunction. Hypoxia activates similar processes, but they predominantly occur within the cells targeting intracellular membrane compartments and ultimately causing cell death. To combat the plasma membrane damage cells have developed several repair mechanisms, such as exocytosis, shedding, and protein-driven membrane remodeling. Analysis of knowledge on these mechanisms reveals that systemic damage to plasma membranes may be associated with potentially reversible MOF, which can be quickly recovered, if pathological stimuli are eliminated. Alternatively, it can be transformed in a non-resolving phase, if repair mechanisms are not sufficient to deal with a large damage or if the damage is extended to intracellular compartments essential for vital cellular functions.

Multiple subregions within the caveolin-1 scaffolding domain inhibit fibrosis, microvascular leakage, and monocyte migration

The caveolin-1 scaffolding domain (CSD, amino acids 82-101 of caveolin-1) has been shown to suppress bleomycin-induced lung and skin fibrosis and angiotensin II (AngII)-induced myocardial fibrosis. To identify active subregions within CSD, we split its sequence into three slightly overlapping 8-amino acid subregions (82-89, 88-95, and 94-101). Interestingly, all three peptides showed activity. In bleomycin-treated mice, all three subregions suppressed the pathological effects on lung and skin tissue morphology. In addition, while bone marrow monocytes isolated from bleomycin-treated mice showed greatly enhanced migration in vitro toward CXCL12, treatment in vivo with CSD and its subregions almost completely suppressed this enhanced migration. In AngII-induced heart failure, both 82-89 and 88-95 significantly suppressed fibrosis (both Col I and HSP47 levels), microvascular leakage, and heart weight/ body weight ratio (HW/BW) while improving ventricular function. In contrast, while 94-101 suppressed the increase in Col I, it did not improve the other parameters. The idea that all three subregions can be active depending on the assay was further supported by experiments studying the in vitro migration of human monocytes in which all three subregions were extremely active. These studies are very novel in that it has been suggested that there is only one active region within CSD that is centered on amino acids 90-92. In contrast, we demonstrate here the presence of other active regions within CSD.

Anti-Septic Functions of Cornuside against HMGB1-Mediated Severe Inflammatory Responses

High mobility group box 1 (HMGB1) is acknowledged to have critical functions; therefore, targeting this protein may have therapeutic effects. One example is potential antiseptic activity obtained by suppressing HMGB1 secretion, leading to the recovery of vascular barrier integrity. Cornuside (CN), which is a product extracted from the fruit of Cornusofficinalis Seib, is a natural bis-iridoid glycoside with the therapeutic effects of suppressing inflammation and regulating immune responses. However, the mechanism of action of CN and impact on sepsis is still unclear. We examined if CN could suppress HMGB1-induced excessive permeability and if the reduction of HMGB1 in response to LPS treatment increased the survival rate in a mouse model of sepsis. In human endothelial cells stimulated by LPS and mice with septic symptoms of cecal ligation and puncture (CLP), we examined levels of proinflammatory proteins and biomarkers as an index of tissue damage, along with decreased vascular permeability. In both LPS-treated human umbilical vein endothelial cells (HUVECs) and the CLP-treated mouse model of sepsis, we applied CN after the induction processes were over. CN suppressed excessive permeability and inhibited HMGB1 release, leading to the amelioration of vascular instability, reduced mortality, and improved histological conditions in the CLP-induced septic mouse model. Overall, we conclude that the suppressed release of HMGB1 and the increased survival rate of mice with CLP-induced sepsis caused by CN may be an effective pharmaceutical treatment for sepsis.

Recent Developments in Nanomaterials-Based Drug Delivery and Upgrading Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the leading causes of morbidity and mortality worldwide. However, despite the recent developments in the management of CVDs, the early and long outcomes vary considerably in patients, especially with the current challenges facing the detection and treatment of CVDs. This disparity is due to a lack of advanced diagnostic tools and targeted therapies, requiring innovative and alternative methods. Nanotechnology offers the opportunity to use nanomaterials in improving health and controlling diseases. Notably, nanotechnologies have recognized potential applicability in managing chronic diseases in the past few years, especially cancer and CVDs. Of particular interest is the use of nanoparticles as drug carriers to increase the pharmaco-efficacy and safety of conventional therapies. Different strategies have been proposed to use nanoparticles as drug carriers in CVDs; however, controversies regarding the selection of nanomaterials and nanoformulation are slowing their clinical translation. Therefore, this review focuses on nanotechnology for drug delivery and the application of nanomedicine in CVDs.

QiShenYiQi Pills Attenuates Ischemia/Reperfusion-Induced Cardiac Microvascular Hyperpermeability Implicating Src/Caveolin-1 and RhoA/ROCK/MLC Signaling

Aims: Coronary microvascular hyperpermeability is an important contributor to ischemia or reperfusion (I/R) injury. However, the effective strategy for this insult remains limited. This study aimed to explore the protective effect of the compound Chinese medicine QiShenYiQi Pills (QSYQ) against coronary microvascular hyperpermeability after cardiac I/R with focusing on the underlying mechanism.

Methods and Results: Male Sprague-Dawley rats under anesthesia were subjected to occlusion of left coronary anterior descending artery followed by reperfusion. QSYQ was administrated 90 min before ischemia initiation. Human cardiac microvascular endothelial cells (HCMECs) underwent hypoxia or reoxygenation (H/R) challenge with QSYQ administrated 1 h prior to hypoxia. QSYQ exhibited effects on attenuating microvascular damage and albumin leakage after I/R injury, showing a role in maintaining endothelial junctions, caveolae, and collagen in basement membrane (BM) of microvessels. Study using HCMECs disclosed that QSYQ protected endothelial barrier from impairment by H/R, attenuating the decline of respiratory chain complex I and ATP synthase, activation of Src/caveolin-1 and increase of RhoA/ROCK/p-MLC, MMP-9, and CTSS. PP2, a Src inhibitor, partially imitated the effect of QSYQ.

Conclusions: The QSYQ was able to prevent I/R-induced cardiac microvascular hyperpermeability via a mechanism involving Src/caveolin-1 and RhoA/ROCK/MLC signaling.

Blood-Brain Barrier, Cell Junctions, and Tumor Microenvironment in Brain Metastases, the Biological Prospects and Dilemma in Therapies

Brain metastasis is the most commonly seen brain malignancy, frequently originating from lung cancer, breast cancer, and melanoma. Brain tumor has its unique cell types, anatomical structures, metabolic constraints, and immune environment, which namely the tumor microenvironment (TME). It has been discovered that the tumor microenvironment can regulate the progression, metastasis of primary tumors, and response to the treatment through the particular cellular and non-cellular components. Brain metastasis tumor cells that penetrate the brain–blood barrier and blood–cerebrospinal fluid barrier to alter the function of cell junctions would lead to different tumor microenvironments. Emerging evidence implies that these tumor microenvironment components would be involved in mechanisms of immune activation, tumor hypoxia, antiangiogenesis, etc. Researchers have applied various therapeutic strategies to inhibit brain metastasis, such as the combination of brain radiotherapy, immune checkpoint inhibitors, and monoclonal antibodies. Unfortunately, they hardly access effective treatment. Meanwhile, most clinical trials of target therapy patients with brain metastasis are always excluded. In this review, we summarized the clinical treatment of brain metastasis in recent years, as well as their influence and mechanisms underlying the differences between the composition of tumor microenvironments in the primary tumor and brain metastasis. We also look forward into the feasibility and superiority of tumor microenvironment-targeted therapies in the future, which may help to improve the strategy of brain metastasis treatment.

Variable fluid flow regimes alter human brain microvascular endothelial cell-cell junctions and cytoskeletal structure

The human brain microvasculature is constantly exposed to variable fluid flow regimes and their influence on the endothelium depends in part on the synchronous cooperative behavior between cell-cell junctions and the cytoskeleton. In this study, we exposed human cerebral microvascular endothelial cells to a low laminar flow (1 dyne⋅cm^-2 ), high laminar flow (10 dyne⋅cm^-2 ), low oscillatory flow (±1 dyne⋅cm^-2 ), or high oscillatory flow (±10 dyne⋅cm^-2 ) for 24 hr. After this time, endothelial cell-cell junction and cytoskeletal structural response was characterized through observation of zonula occludens-1 (ZO-1), claudin-5, junctional adhesion molecule-A (JAM-A), vascular endothelial cadherin (VE-Cad), and F-actin. In addition, we also characterized cell morphology through measurement of cell area and cell eccentricity. Our results revealed the greatest change in junctional structure reorganization for ZO-1 and JAM-A to be observed under low laminar flow conditions while claudin-5 exhibited the greatest change in structural reorganization under both low and high laminar flow conditions. However, VE-Cad displayed the greatest structural response under a high laminar flow, reflecting the unique responses each cell-cell junction protein had to each fluid flow regime. In addition, cell area and cell eccentricity displayed most significant changes under the high laminar flow and low oscillatory flow, respectively. We believe this study will be useful to the field of cell mechanics and mechanobiology.

The role of anti-inflammatory drugs and nanoparticle-based drug delivery models in the management of ischemia-induced heart failure

Ongoing advancements in the treatment of acute myocardial infarction (MI) have significantly decreased MI related mortality. Consequently, the number of patients experiencing post-MI heart failure (HF) has continued to rise. Infarction size and the extent of left ventricular (LV) remodeling are largely determined by the extent of ischemia at the time of myocardial injury. In the setting of MI or acute phase of post-MI LV remodeling, anti-inflammatory drugs including intravenous immunoglobulin (IVIG) and Pentoxifylline have shown potential efficacy in preventing post-MI remodeling in-vitro and in some clinical trials. However, systemic administration of anti-inflammatory drugs are not without their off-target side effects. Herein, we explore the clinical feasibility of targeted myocardial delivery of anti-inflammatory drugs via biodegradable polymers, liposomes, hydrogels, and nano-particle based drug delivery models (NDDM) based on existing pre-clinical and clinical models. We summarize the barriers to clinical application of targeted anti-inflammatory delivery post-MI, including challenges in achieving sufficient retention and distribution, as well as the potential need for multiple dosing. Collectively, we suggest that localized delivery of anti-inflammatory agents to the myocardium using NDDM is a promising approach for successful treatment of ischemic HF. Future studies will be instrumental in determining the most effective target and delivery modalities for orchestrating NDDM-mediated treatment of HF.

Investigating the Multi-Faceted Nature of Radiation-Induced Coagulopathies in a Göttingen Minipig Model of Hematopoietic Acute Radiation Syndrome

Coagulopathies are well documented after acute radiation exposure at hematopoietic doses, and radiation-induced bleeding is notably one of the two main causes of mortality in the hematopoietic acute radiation syndrome. Despite this, understanding of the mechanisms by which radiation alters hemostasis and induces bleeding is still lacking. Here, male Göttingen minipigs received hematopoietic doses of 60Co gamma irradiation (total body) and coagulopathies were characterized by assessing bleeding, blood cytopenia, fibrin deposition, changes in hemostatic properties, coagulant/anticoagulant enzyme levels, and markers of inflammation, endothelial dysfunction, and barrier integrity to understand if a relationship exists between bleeding, hemostatic defects, bone marrow aplasia, inflammation, endothelial dysfunction and loss of barrier integrity. Acute radiation exposure induced coagulopathies in the Göttingen minipig model of hematopoietic acute radiation syndrome; instances of bleeding were not dependent upon thrombocytopenia. Neutropenia, alterations in hemostatic parameters and damage to the glycocalyx occurred in all animals irrespective of occurrence of bleeding. Radiation-induced bleeding was concurrent with simultaneous thrombocytopenia, anemia, neutropenia, inflammation, increased heart rate, decreased nitric oxide bioavailability and endothelial dysfunction; bleeding was not observed with the sole occurrence of a single aforementioned parameter in the absence of the others. Alteration of barrier function or clotting proteins was not observed in all cases of bleeding. Additionally, fibrin deposition was observed in the heart and lungs of decedent animals but no evidence of DIC was noted, suggesting a unique pathophysiology of radiation-induced coagulopathies. These findings suggest radiation-induced coagulopathies are the result of simultaneous damage to several key organs and biological functions, including the immune system, the inflammatory response, the bone marrow and the cardiovasculature.

The Caveolin-1 Scaffolding Domain Peptide Reverses Aging-Associated Deleterious Changes in Multiple Organs

Aging is a progressive, multifactorial, degenerative process in which deleterious changes occur in the biochemistry and function of organs. We showed that angiotensin II (AngII)-induced pathologies in the heart and kidney of young (3-month-old) mice are suppressed by the caveolin-1 scaffolding domain (CSD) peptide. Because AngII mediates many aging-associated changes, we explored whether CSD could reverse pre-existing pathologies and improve organ function in aged mice. Using 18-month-old mice (similar to 60-year-old humans), we found that >5-fold increases in leakage of serum proteins and >2-fold increases in fibrosis are associated with aging in the heart, kidney, and brain. Because tyrosine phosphorylation of cell junction proteins leads to the loss of microvascular barrier function, we analyzed the activation of the receptor tyrosine kinase PDGFR and the nonreceptor tyrosine kinases c-Src and Pyk2. We observed 5-fold activation of PDGFR and 2- to 3-fold activation of c-Src and Pyk2 in aged mice. Treatment with CSD for 4 weeks reversed these pathologic changes (microvascular leakage, fibrosis, kinase activation) in all organs almost down to the levels in healthy, young mice. In studies of heart function, CSD reduced the aging-associated increase in cardiomyocyte cross-sectional area and enhanced ventricular compliance in that echocardiographic studies demonstrated improved ejection fraction and fractional shortening and reduced isovolumic relation time. These results suggest that versions of CSD may be developed as treatments for aging-associated diseases in human patients based on the concept that CSD inhibits tyrosine kinases, leading to the inhibition of microvascular leakage and associated fibrosis, thereby improving organ function. SIGNIFICANCE STATEMENT: The caveolin-1 scaffolding domain (CSD) peptide reverses aging-associated fibrosis, microvascular leakage, and organ dysfunction in the heart, kidneys, and brain via a mechanism that involves the suppression of the activity of multiple tyrosine kinases, suggesting that CSD can be developed as a treatment for a wide range of diseases found primarily in the aged.

Barrier protective functions of hederacolchiside-E against HMGB1-mediated septic responses

The role of high mobility group box 1 (HMGB1) has been recognized as important, and suppression of HMGB1 release and restoration of vascular barrier integrity are regarded as potentially promising therapeutic strategies against sepsis. Hederacolchiside-E (HCE), namely 3-O-{α-L-rhamnopyranosyl (1→2)-[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranosyl}-28-O-[α-L-rhamnopyranosyl (1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranosyl ester, is a bidesmosidic oleanane saponin first isolated in 1970 from the leaves of Hedera colchica. We tested our hypothesis that HCE inhibits HMGB1-induced vascular hyperpermeability and thereby increases the survival of septic mouse model from suppression of HMGB1 release upon lipopolysaccharide (LPS)-stimulation. In LPS-activated human endothelial cells and a sepsis mouse model by cecal ligation and puncture (CLP), antiseptic activity of HCE was investigated from suppression of vascular permeability, pro-inflammatory proteins, and tissue injury markers. Post-treatment of HCE significantly suppressed HMGB1 release both in LPS-activated human endothelial cells and the CLP-induced sepsis mouse model. HCE inhibited hyperpermeability and alleviated HMGB1-mediated vascular disruptions, and reduced sepsis-related mortality and tissue injury in mice. Our results suggest that reduction of HMGB1 release and septic mortality by HCE may be useful for the drug candidate of sepsis, indicating a possibility of successful repositioning of HCE.

FKBPL is associated with metabolic parameters and is a novel determinant of cardiovascular disease

Type 2 diabetes (T2D) is associated with increased risk of cardiovascular disease (CVD). As disturbed angiogenesis and endothelial dysfunction are strongly implicated in T2D and CVD, we aimed to investigate the association between a novel anti-angiogenic protein, FK506-binding protein like (FKBPL), and these diseases. Plasma FKBPL was quantified by ELISA cross-sectionally in 353 adults, consisting of 234 T2D and 119 non-diabetic subjects with/without CVD, matched for age, BMI and gender. FKBPL levels were higher in T2D (adjusted mean: 2.03 ng/ml ± 0.90 SD) vs. non-diabetic subjects (adjusted mean: 1.79 ng/ml ± 0.89 SD, p = 0.02), but only after adjustment for CVD status. In T2D, FKBPL was negatively correlated with fasting blood glucose, HbA1c and diastolic blood pressure (DBP), and positively correlated with age, known diabetes duration, waist/hip ratio, urinary albumin/creatinine ratio (ACR) and fasting C-peptide. FKBPL plasma concentrations were increased in the presence of CVD, but only in the non-diabetic group (CVD: 2.02 ng/ml ± 0.75 SD vs. no CVD: 1.68 ng/ml ± 0.79 SD, p = 0.02). In non-diabetic subjects, FKBPL was positively correlated with an established biomarker for CVD, B-type Natriuretic Peptide (BNP), and echocardiographic parameters of diastolic dysfunction. FKBPL was a determinant of CVD in the non-diabetic group in addition to age, gender, total-cholesterol and systolic blood pressure (SBP). FKBPL may be a useful anti-angiogenic biomarker in CVD in the absence of diabetes and could represent a novel CVD mechanism.

Vascular endothelial growth factor promotes atrial arrhythmias by inducing acute intercalated disk remodeling

Atrial fibrillation (AF) is the most common arrhythmia and is associated with inflammation. AF patients have elevated levels of inflammatory cytokines known to promote vascular leak, such as vascular endothelial growth factor A (VEGF). However, the contribution of vascular leak and consequent cardiac edema to the genesis of atrial arrhythmias remains unknown. Previous work suggests that interstitial edema in the heart can acutely promote ventricular arrhythmias by disrupting ventricular myocyte intercalated disk (ID) nanodomains rich in cardiac sodium channels (Na_V1.5) and slowing cardiac conduction. Interestingly, similar disruption of ID nanodomains has been identified in atrial samples from AF patients. Therefore, we tested the hypothesis that VEGF-induced vascular leak can acutely increase atrial arrhythmia susceptibility by disrupting ID nanodomains and slowing atrial conduction. Treatment of murine hearts with VEGF (30–60 min, at clinically relevant levels) prolonged the electrocardiographic P wave and increased susceptibility to burst pacing-induced atrial arrhythmias. Optical voltage mapping revealed slower atrial conduction following VEGF treatment (10 ± 0.4 cm/s vs. 21 ± 1 cm/s at baseline, p < 0.05). Transmission electron microscopy revealed increased intermembrane spacing at ID sites adjacent to gap junctions (GJs; 64 ± 9 nm versus 17 ± 1 nm in controls, p < 0.05), as well as sites next to mechanical junctions (MJs; 63 ± 4 nm versus 27 ± 2 nm in controls, p < 0.05) in VEGF–treated hearts relative to controls. Importantly, super-resolution microscopy and quantitative image analysis revealed reorganization of Na_V1.5 away from dense clusters localized near GJs and MJs to a more diffuse distribution throughout the ID. Taken together, these data suggest that VEGF can acutely predispose otherwise normal hearts to atrial arrhythmias by dynamically disrupting Na_V1.5-rich ID nanodomains and slowing atrial conduction. These data highlight inflammation-induced vascular leak as a potential factor in the development and progression of AF.

The long noncoding RNA HCG18 participates in PM2.5-mediated vascular endothelial barrier dysfunction

Increased vascular endothelial permeability can disrupt vascular barrier function and further lead to multiple human diseases. Our previous reports indicated that particulate matter 2.5 (PM2.5) can enhance the permeability of vascular endothelial cells. However, the regulatory mechanism was not comprehensively demonstrated. Therefore, this work elucidated this mechanism by demonstrating that PM2.5 can increase the permeability of HUVECs by inhibiting the expression of Hickson compact group 18 (HCG18). Moreover, we demonstrated that lncRNA HCG18 functioned as a ceRNA for miR-21-5p and led to the derepression of its target SOX7, which could further transcriptionally activate the expression of VE-cadherin to regulate the permeability of HUVECs. In this study, we provide evidence that HCG18/miR-21-5p/SOX7/VE-cadherin signaling is involved in PM2.5-induced vascular endothelial barrier dysfunction.

Long non-coding RNA LASSIE regulates shear stress sensing and endothelial barrier function

Blood vessels are constantly exposed to shear stress, a biomechanical force generated by blood flow. Normal shear stress sensing and barrier function are crucial for vascular homeostasis and are controlled by adherens junctions (AJs). Here we show that AJs are stabilized by the shear stress-induced long non-coding RNA LASSIE (linc00520). Silencing of LASSIE in endothelial cells impairs cell survival, cell-cell contacts and cell alignment in the direction of flow. LASSIE associates with junction proteins (e.g. PECAM-1) and the intermediate filament protein nestin, as identified by RNA affinity purification. The AJs component VE-cadherin showed decreased stabilization, due to reduced interaction with nestin and the microtubule cytoskeleton in the absence of LASSIE. This study identifies LASSIE as link between nestin and VE-cadherin, and describes nestin as crucial component in the endothelial response to shear stress. Furthermore, this study indicates that LASSIE regulates barrier function by connecting AJs to the cytoskeleton.

Stanicek et al identify a shear stress-induced long non-coding RNA they name LASSIE, which stabilises junctions between endothelial cells through interactions with junctional and cytoskeletal proteins. This study provides insights into how a transcript that does not encode a protein controls endothelial response to forces associated with blood flow and endothelial barrier function.

Combining Nanomaterials and Developmental Pathways to Design New Treatments for Cardiac Regeneration: The Pulsing Heart of Advanced Therapies

The research for heart therapies is challenged by the limited intrinsic regenerative capacity of the adult heart. Moreover, it has been hampered by the poor results obtained by tissue engineering and regenerative medicine attempts at generating functional beating constructs able to integrate with the host tissue. For this reason, organ transplantation remains the elective treatment for end-stage heart failure, while novel strategies aiming to promote cardiac regeneration or repair lag behind. The recent discovery that adult cardiomyocytes can be ectopically induced to enter the cell cycle and proliferate by a combination of microRNAs and cardioprotective drugs, like anti-oxidant, anti-inflammatory, anti-coagulants and anti-platelets agents, fueled the quest for new strategies suited to foster cardiac repair. While proposing a revolutionary approach for heart regeneration, these studies raised serious issues regarding the efficient controlled delivery of the therapeutic cargo, as well as its timely removal or metabolic inactivation from the site of action. Especially, there is need for innovative treatment because of evidence of severe side effects caused by pleiotropic drugs. Biocompatible nanoparticles possess unique physico-chemical properties that have been extensively exploited for overcoming the limitations of standard medical therapies. Researchers have put great efforts into the optimization of the nanoparticles synthesis and functionalization, to control their interactions with the biological milieu and use as a viable alternative to traditional approaches. Nanoparticles can be used for diagnosis and deliver therapies in a personalized and targeted fashion. Regarding the treatment of cardiovascular diseases, nanoparticles-based strategies have provided very promising outcomes, in preclinical studies, during the last years. Efficient encapsulation of a large variety of cargos, specific release at the desired site and improvement of cardiac function are some of the main achievements reached so far by nanoparticle-based treatments in animal models. This work offers an overview on the recent nanomedical applications for cardiac regeneration and highlights how the versatility of nanomaterials can be combined with the newest molecular biology discoveries to advance cardiac regeneration therapies.

Dual peptide-dendrimer conjugate inhibits acetylation of transforming growth factor β-induced protein and improves survival in sepsis

Sepsis is a potentially fatal complication of infections and there are currently no effective therapeutic options for severe sepsis. In this study, we revealed the secretion mechanism of transforming growth factor β-induced protein (TGFBIp) that was recently identified as a therapeutic target for sepsis, and designed TGFBIp acetylation inhibitory peptide (TAIP) that suppresses acetylation of lysine 676 in TGFBIp. To improve bioavailability and biodegradation of the peptide, TAIP was conjugated to polyamidoamine (PAMAM) dendrimers. Additionally, the cell-penetrating peptide (CPP) was conjugated to the TAIP-modified PAMAM dendrimers for the intracellular delivery of TGFBIp. The resulting nanostructures, decorated with TAIP and CPP via poly(ethylene glycol) linkage, improved the mortality and organ damage in the septic mouse model and suppressed lipopolysaccharide-activated severe vascular inflammatory responses in endothelial cells. Thus, the dendrimer-based nanostructures for delivery of TAIP using CPP show great promise in practical applications in sepsis therapy.

Phosphoproteomic analysis of protease-activated receptor-1 biased signaling reveals unique modulators of endothelial barrier function

Thrombin, a procoagulant protease, cleaves and activates protease-activated receptor-1 (PAR1) to promote inflammatory responses and endothelial dysfunction. In contrast, activated protein C (APC), an anticoagulant protease, activates PAR1 through a distinct cleavage site and promotes anti-inflammatory responses, prosurvival, and endothelial barrier stabilization. The distinct tethered ligands formed through cleavage of PAR1 by thrombin versus APC result in unique active receptor conformations that bias PAR1 signaling. Despite progress in understanding PAR1 biased signaling, the proteins and pathways utilized by thrombin versus APC signaling to induce opposing cellular functions are largely unknown. Here, we report the global phosphoproteome induced by thrombin and APC signaling in endothelial cells with the quantification of 11,266 unique phosphopeptides using multiplexed quantitative mass spectrometry. Our results reveal unique dynamic phosphoproteome profiles of thrombin and APC signaling, an enrichment of associated biological functions, including key modulators of endothelial barrier function, regulators of gene transcription, and specific kinases predicted to mediate PAR1 biased signaling. Using small interfering RNA to deplete a subset of phosphorylated proteins not previously linked to thrombin or APC signaling, a function for afadin and adducin-1 actin binding proteins in thrombin-induced endothelial barrier disruption is unveiled. Afadin depletion resulted in enhanced thrombin-promoted barrier permeability, whereas adducin-1 depletion completely ablated thrombin-induced barrier disruption without compromising p38 signaling. However, loss of adducin-1 blocked APC-induced Akt signaling. These studies define distinct thrombin and APC dynamic signaling profiles and a rich array of proteins and biological pathways that engender PAR1 biased signaling in endothelial cells.

Organic Isothiocyanates as Hydrogen Sulfide Donors

Significance: Hydrogen sulfide (H₂S), the "new entry" in the series of endogenous gasotransmitters, plays a fundamental role in regulating the biological functions of various organs and systems. Consequently, the lack of adequate levels of H₂S may represent the etiopathogenetic factor of multiple pathological alterations. In these diseases, the use of H₂S donors represents a precious and innovative opportunity. Recent Advances: Natural isothiocyanates (ITCs), sulfur compounds typical of some botanical species, have long been investigated because of their intriguing pharmacological profile. Recently, the ITC moiety has been proposed as a new H₂S-donor chemotype (with a l-cysteine-mediated reaction). Based on this recent discovery, we can clearly observe that almost all the effects of natural ITCs can be explained by the H₂S release. Consistently, the ITC function was also used as an original H₂S-releasing moiety for the design of synthetic H₂S donors and original "pharmacological hybrids." Very recently, the chemical mechanism of H₂S release, resulting from the reaction between l-cysteine and some ITCs, has been elucidated. Critical Issues: Available literature gives convincing demonstration that H₂S is the real player in ITC pharmacology. Further, countless studies have been carried out on natural ITCs, but this versatile moiety has been used only rarely for the design of synthetic H₂S donors with optimal drug-like properties. Future Directions: The development of more ITC-based synthetic H₂S donors with optimal drug-like properties and selectivity toward specific tissues/pathologies seem to represent a stimulating and indispensable prospect of future experimental activities.

Fibronectin in Cancer: Friend or Foe

The role of fibronectin (FN) in tumorigenesis and malignant progression has been highly controversial. Cancerous FN plays a tumor-suppressive role, whereas it is pro-metastatic and associated with poor prognosis. Interestingly, FN matrix deposited in the tumor microenvironments (TMEs) promotes tumor progression but is paradoxically related to a better prognosis. Here, we justify how FN impacts tumor transformation and subsequently metastatic progression. Next, we try to reconcile and rationalize the seemingly conflicting roles of FN in cancer and TMEs. Finally, we propose future perspectives for potential FN-based therapeutic strategies.

Albumin nanocomposites with MnO2/Gd2O3 motifs for precise MR imaging of acute myocardial infarction in rabbit models

The severe mortality and morbidity of myocardial infarction requests appropriate and accurate detection. Considering pathological profile of the acidic myocardial infarction microenvironments, herein, the low pH-sensitive albumin nanocomposites with MnO₂ motifs (MnO₂@BSA) have been engineered for T₁-weighted MR imaging of myocardial infarction, while using non-pH-responsive Gd₂O₃@BSA nanocomposites as control. The nanocomposites were 20-30 nm in diameter with spheroid morphology. Besides, the MnO₂@BSA have exhibited pH-triggered releasing of Mn²⁺, demonstrating approximately 38-fold and 55-fold increased molecular relaxivity at acute myocardial infarction-mimicking pH 6.5 (13.08 mM^-1s^-1) and macrophage intracellular pH 5.0 (18.76 mM^-1s^-1) compared to the extremely low relaxivity (0.34 mM^-1s^-1) at normal physiological conditions (pH 7.4). However, the Gd₂O₃@BSA with molecular relaxivity approximately 10 mM^-1s^-1 were without pH-sensitive properties. Furthermore, the MnO₂@BSA have demonstrated high accumulation in the acute myocardial infarction regions and fast metabolism from the body after systemic injection, accounting high contrast enhancement for accurate MR imaging of acute myocardial infarction in rabbit models, demonstrating better diagnostic performance over the controls.

Nanoparticle-mediated delivery of siRNA into zebrafish heart: a cell-level investigation on the biodistribution and gene silencing effects

Nanomaterials hold promise for the delivery of nucleic acids to facilitate gene therapy in cardiac diseases. However, as much of the in vivo study of nanomaterials was conducted via the "trial and error" method, the understanding of the nanomaterial-mediated delivery in cardiac tissue was limited to the gross efficiency in manipulating the gene expression while little was known about the delivery process and mechanism in particular at the cell level. In this study, small interfering RNA (siRNA) nanoparticles formulated with a polyamidoamine (PAMAM) nanomaterial were applied to the injured heart of zebrafish. The distribution of nanoparticles in cardiomyocytes, endothelial cells, macrophages and leukocytes was quantitatively analyzed with precision at the cell level by using transgenic models. Based on the distribution characteristics, gene silencing effects in a specific group of cells were analyzed to illustrate how siRNA nanoparticles could get potent gene silencing in different cells in vivo. The results elucidated the heterogeneous distribution of siRNA nanoparticles and how nanoparticles could be efficient despite the significant difference in cellular uptake efficiency in different cells. It demonstrated a paradigm and the need to decouple cellular processes to understand nanoparticle-mediated delivery in complex tissue and the investigation/methodology may lead to important information to guide the design of advanced targeted drug-delivery systems in heart.

Nanoscale systems for local drug delivery

Many diseases and conditions affect a relatively localized area of the body. They can be treated either by direct deposition of drug in the target area, or by giving the drug systemically. Here we review nanoparticle-based approaches to achieving both. We highlight advantages and disadvantages that nanoscale solutions have for locally administered therapies, with emphasis on the former. We discuss strategies to enable systemically delivered nanoparticles to deliver their payloads at specific locations in the body, including triggering (local and remote) and targeting.

Targeted Myocardial Hypoxia Imaging Using a Nitroreductase-Activatable Near-Infrared Fluorescent Nanoprobe

Development of a highly selective and sensitive imaging probe for accurate detection of myocardial hypoxia will be helpful to estimate the degree of ischemia and subsequently guide personalized treatment. However, an efficient optical approach for hypoxia monitoring in myocardial ischemia is still lacking. In this work, a cardiomyocyte-specific and nitroreductase-activatable near-infrared nanoprobe has been developed for selective and sensitive imaging of myocardial hypoxia. The nanoprobe is a liposome-based nanoarchitecture which is functionalized with a peptide (GGGGDRVYIHPF) for targeting heart cells and encapsulating a nitrobenzene-substituted BODIPY for nitroreductase imaging. The nanoprobe can specifically recognize and bind to angiotensin II type 1 receptor that is overexpressed on the ischemic heart cells by the peptide and is subsequently uptaken into heart cells, in which the probe is released and activated by hypoxia-related nitroreductase to produce fluorescence emission at 713 nm. The in vitro response of the nanoprobe toward nitroreductase resulted in 55-fold fluorescence enhancement with the limit of detection as low as 7.08 ng/mL. Confocal fluorescence imaging confirmed the successful uptake of nanoprobe by hypoxic heart cells and intracellular detection of nitroreductase. More significantly, in vivo imaging of hypoxia in a murine model of myocardial ischemia was achieved by the nanoprobe with high sensitivity and good biocompatibility. Therefore, this work presents a new tool for targeted detection of myocardial hypoxia and will promote the investigation of the hypoxia-related physiological and pathological process of ischemic heart disease.

G protein-coupled receptors activate p38 MAPK via a non-canonical TAB1-TAB2- and TAB1-TAB3-dependent pathway in endothelial cells

Endothelial dysfunction is induced by inflammatory mediators including multiple G protein-coupled receptor (GPCR) agonists. However, the GPCR signaling pathways that promote endothelial dysfunction are incompletely understood. We previously showed that thrombin promotes endothelial barrier disruption through autophosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) via a non-canonical transforming growth factor-β-activated protein kinase-1-binding protein-1 (TAB1) and TAB2-dependent pathway rather than the canonical three-tiered kinase cascade. Here, we sought to determine whether other GPCR agonists stimulate p38 MAPK activation via this non-canonical pathway in human endothelial cells derived from different vascular beds. Using primary human umbilical vein endothelial cells (HUVECs), HUVEC-derived EA.hy926 cells, and human dermal microvascular endothelial cells (HDMECs), we found that both non-canonical and canonical p38 activation pathways components are expressed in these various endothelial cell types, including TAB3, a structurally-related TAB2 homolog. Moreover, multiple GPCRs agonists, including thrombin, histamine, prostaglandin E₂, and ADP, stimulated robust p38 autophosphorylation, whereas phosphorylation of the upstream MAPKs MAP kinase kinase 3 (MKK3) and MKK6, was virtually undetectable, indicating that non-canonical p38 activation may exist for other GPCRs. Indeed, in EA.hy926 cells, thrombin- and histamine-stimulated p38 activation depended on TAB1-TAB2, whereas in primary HUVECs, both TAB1-TAB2 and TAB1-TAB3 were required for p38 activation. In HDMECs, thrombin-induced p38 activation depended on TAB1-TAB3, but histamine-induced p38 activation required TAB1-TAB2. Moreover, thrombin- and histamine-stimulated interleukin-6 production required both TAB1-TAB2 and TAB1-TAB3 in HUVEC. We conclude that multiple GPCR agonists utilize non-canonical TAB1-TAB2 and TAB1-TAB3-dependent p38 activation to promote endothelial inflammatory responses.

Nano-carriers for drug routeing - towards a new era

The objective of this article is to propose a re-visiting of the paradigms of nano-carriers based drug routeing from an industrial viewpoint. The accumulation of drugs in specific body compartments after intravenous administration and the improvement of the oral bioavailability of peptides were taken as examples to propose an update of the translational framework preceding industrialisation. In addition to the recent advances on the biopharmacy of nano-carriers, the evolution of adjacent disciplines such as the biology of diseases, the chemistry of polymers, lipids and conjugates, the physico-chemistry of colloids and the assembling of materials at the nanoscale (referred to as microfluidics) are taken into account to consider new avenues in the applications of drug nano-carriers. The deeper integration of the properties of the drug and of the nano-carrier, in the specific context of the disease, advocates for product oriented programmes. At the same time, the advent of powerful collaborative digital tools makes possible the extension of the expertise spectrum. In this open-innovation framework, the Technology Readiness Levels (TRLs) of nano-carriers are proposed as a roadmap for the translational process from the Research stage to the Proof-of-Concept in human.

MnO nanoparticles with potential application in magnetic resonance imaging and drug delivery for myocardial infarction

Background

Myocardial infarction (MI) is a leading cause of death worldwide. Therefore, nanoparticles that applied for specific diagnosis of the infarcted area and/or local myocardial delivery of therapeutic agents, are highly desired.

Materials and methods

Herein, we developed the MnO-based nanoparticles, with magnetic resonance (MR) and near-infrared fluorescence imaging modalities as an MR imaging contrast agent and potential drug vehicle for the detection and treatment of MI. The chemophysical characteristics, targeting ability toward infarcted myocardium, biodistribution, and biocompatibility of the MnO-based nanoparticles were studied.

Results

It was found that the MnO-based dual-modal nanoparticles possess high r₁ relaxivity and induced no notable in vitro or in vivo toxicity. In a rat model of MI, these nanoparticles represent a very promising MR imaging contrast agent for sensitive and specific detection of the infarcted area, more importantly, without cardiotoxicity, the major defect of conventional Mn-based contrasts. Moreover, ex vivo near-infrared fluorescence imaging indicated that the MnO nanoparticles preferentially accumulate in the infarcted myocardium, which makes them an ideal drug vehicle for MI treatment.

Conclusion

In summary, the use of these MnO nanoparticles as a T₁-weighted MR imaging contrast agent and potential drug vehicle to target the infarcted myocardium may provide new opportunities for accurate detection of myocardial infarct and treatment of ischemic heart diseases.

RSPO3 impairs barrier function of human vascular endothelial monolayers and synergizes with pro-inflammatory IL-1

BACKGROUND

Endothelial barrier dysfunction characterized by hyperpermeability of the vascular endothelium is a key factor in the pathogenesis of chronic inflammatory diseases and affects clinical outcomes. In states of chronic inflammation, mediators secreted by activated immune cells or vascular endothelium may affect the barrier function and permeability of the vascular endothelium. The matricellular R-spondin family member RSPO3 is produced by inflammatory-activated human monocytes and vascular endothelial cells, but its effects in the regulation of vascular endothelial barrier function remains elusive.

METHODS

The present study investigates the effects of RSPO3 on the barrier function of adult human primary macro- and micro- vascular endothelial monolayers. Tight monolayers of primary endothelial cells from human coronary and pulmonary arteries, and cardiac, brain, and dermal microvascular beds were treated with RSPO3 either alone or in combination with pro-inflammatory mediator IL-1β. Endothelial barrier function was assessed non-invasively in real-time using Electric Cell-substrate Impedance Sensing.

RESULTS

RSPO3 treatment critically affected barrier function by enhancing the permeability of all vascular endothelial monolayers investigated. To confer hyperpermeable phenotype in vascular endothelial monolayers, RSPO3 induced inter-endothelial gap formation by disrupting the β-catenin and VE-cadherin alignment at adherens junctions. RSPO3 synergistically enhanced the barrier impairing properties of the pro-inflammatory mediator IL-1β.

CONCLUSION

Here, we show that the matricellular protein RSPO3 is a mediator of endothelial hyperpermeability that can act in synergy with the inflammatory mediator IL-1β. This finding stimulates further studies to delineate the endothelial barrier impairing properties of RSPO3 and its synergistic interaction with IL-1β in chronic inflammatory diseases.

MRI with gadofosveset: A potential marker for permeability in myocardial infarction

BACKGROUND AND AIMS

Acute ischemia is associated with myocardial endothelial damage and microvessel formation, resulting in leakage of plasma albumin into the myocardial extravascular space. In this study, we tested whether an albumin-binding intravascular contrast agent (gadofosveset) allows for improved quantification of myocardial permeability compared to the conventional extracellular contrast agent Gd-DTPA using late gadolinium enhancement (LGE) and T1 mapping in vivo.

METHODS

MI was induced in C57BL/6 mice (n = 6) and cardiac magnetic resonance imaging (CMR) was performed at 3, 10 and 21 days post-MI using Gd-DTPA and 24 h later using gadofosveset. Functional, LGE and T1 mapping protocols were performed 45 min post-injection of the contrast agent.

RESULTS

LGE images showed that both contrast agents provided similar measurements of infarct area at all time points following MI. Importantly, the myocardial R1 measurements after administration of gadofosveset were higher in the acute phase-day 3 (R1 [s-1] = 6.29 ± 0.29) compared to the maturation phase-days 10 and 21 (R1 [s-1] = 4.76 ± 0.30 and 4.48 ± 0.14), suggesting that the uptake of this agent could be used to stage myocardial remodeling. No differences in myocardial R1 were observed after administration of Gd-DTPA at different time points post-MI (R1 [s-1] = 3d: 3.77 ± 0.37; 10d: 2.74 ± 0.06; 21d: 3.35 ± 0.26). The MRI results were validated by ex vivo histology that showed albumin leakage in the myocardium in the acute phase and microvessel formation at later stages.

CONCLUSIONS

We demonstrate the merits of an albumin-binding contrast agent for monitoring changes in myocardial permeability between acute ischemia and chronic post-MI myocardial remodeling.

Water extract of Clinacanthus nutans leaves exhibits in vitro, ex vivo and in vivo anti-angiogenic activities in endothelial cell via suppression of cell proliferation

BACKGROUND

Clinacanthus nutans (Burm. f.) Lindau. has traditionally been using in South East Asia countries to manage cancer. However, scientific evidence is generally lacking to support this traditional claim. This study aims to investigate the in vitro, ex-vivo and in vivo effects of C. nutans extracts on angiogenesis.

METHODS

C. nutans leaves was extracted with 50-100% ethanol or deionised water at 1% (w/v). Human umbilical veins endothelial cell (HUVEC) proliferation was examined using MTT assay. The in vitro anti-angiogenic effects of C. nutans were assessed using wound scratch, tube formation and transwell migration assays. The VEGF levels secreted by human oral squamous cell carcinoma (HSC-4) cell and HUVEC permeability were also measured. Besides, the rat aortic ring and chick embryo chorioallantoic membrane (CAM) assays, representing ex vivo and in vivo models, respectively, were performed.

RESULTS

The MTT assay revealed that water extract of C. nutans leaves exhibited the highest activity, compared to the ethanol extracts. Therefore, the water extract was chosen for subsequent experiments. C. nutans leaf extract significantly suppressed endothelial cell proliferation and migration in both absence and presence of VEGF. However, the water extract failed to suppress HUVEC transmigration, differentiation and permeability. C. nutans water extract also did not suppress HSC-4 cell-induced VEGF production. Importantly, C. nutans water extract significantly abolished the sprouting of vessels in aortic rings as well as in chick embryo CAM.

CONCLUSION

In conclusion, these findings reveal potential anti-angiogenic effects of C. nutans, providing new evidence for its potential application as an anti-angiogenic agent.

Peptide and protein nanoparticle conjugates: versatile platforms for biomedical applications

Peptide- and protein-nanoparticle conjugates have emerged as powerful tools for biomedical applications, enabling the treatment, diagnosis, and prevention of disease. In this review, we focus on the key roles played by peptides and proteins in improving, controlling, and defining the performance of nanotechnologies. Within this framework, we provide a comprehensive overview of the key sequences and structures utilised to provide biological and physical stability to nano-constructs, direct particles to their target and influence their cellular and tissue distribution, induce and control biological responses, and form polypeptide self-assembled nanoparticles. In doing so, we highlight the great advances made by the field, as well as the challenges still faced in achieving the clinical translation of peptide- and protein-functionalised nano-drug delivery vehicles, imaging species, and active therapeutics.

Targeting regenerative exosomes to myocardial infarction using cardiac homing peptide

Rationale: Cardiac stem cell-derived exosomes have been demonstrated to promote cardiac regeneration following myocardial infarction in preclinical studies. Recent studies have used intramyocardial injection in order to concentrate exosomes in the infarct. Though effective in a research setting, this method is not clinically appealing due to its invasive nature. We propose the use of a targeting peptide, cardiac homing peptide (CHP), to target intravenously-infused exosomes to the infarcted heart. Methods: Exosomes were conjugated with CHP through a DOPE-NHS linker. Ex vivo targeting was analyzed by incubating organ sections with the CHP exosomes and analyzing with fluorescence microscopy. In vitro assays were performed on neonatal rat cardiomyocytes and H9C2 cells. For the animal study, we utilized an ischemia/reperfusion rat model. Animals were treated with either saline, scramble peptide exosomes, or CHP exosomes 24 h after surgery. Echocardiography was performed 4 h after surgery and 21 d after surgery. At 21 d, animals were sacrificed, and organs were collected for analysis. Results: By conjugating the exosomes with CHP, we demonstrate increased retention of the exosomes within heart sections ex vivo and in vitro with neonatal rat cardiomyocytes. In vitro studies showed improved viability, reduced apoptosis and increased exosome uptake when using CHP-XOs. Using an animal model of ischemia/reperfusion injury, we measured the heart function, infarct size, cellular proliferation, and angiogenesis, with improved outcomes with the CHP exosomes. Conclusions: Our results demonstrate a novel method for increasing delivery of for treatment of myocardial infarction. By targeting exosomes to the infarcted heart, there was a significant improvement in outcomes with reduced fibrosis and scar size, and increased cellular proliferation and angiogenesis.

Statins Promote Cardiac Infarct Healing by Modulating Endothelial Barrier Function Revealed by Contrast-Enhanced Magnetic Resonance Imaging

OBJECTIVE

The endothelium has a crucial role in wound healing, acting as a barrier to control transit of leukocytes. Endothelial barrier function is impaired in atherosclerosis preceding myocardial infarction (MI). Besides lowering lipids, statins modulate endothelial function. Here, we noninvasively tested whether statins affect permeability at the inflammatory (day 3) and the reparative (day 7) phase of infarct healing post-MI using contrast-enhanced cardiac magnetic resonance imaging (MRI).

APPROACH AND RESULTS

Noninvasive permeability mapping by MRI after MI in C57BL/6, atherosclerotic ApoE^-/-, and statin-treated ApoE^-/- mice was correlated to subsequent left ventricular outcome by structural and functional cardiac MRI. Ex vivo histology, flow cytometry, and quantitative polymerase chain reaction were performed on infarct regions. Increased vascular permeability at ApoE^-/- infarcts was observed compared with C57BL/6 infarcts, predicting enhanced left ventricular dilation at day 21 post-MI by MRI volumetry. Statin treatment improved vascular barrier function at ApoE^-/- infarcts, indicated by reduced permeability. The infarcted tissue of ApoE^-/- mice 3 days post-MI displayed an unbalanced Vegfa(vascular endothelial growth factor A)/Angpt1 (angiopoetin-1) expression ratio (explaining leakage-prone vessels), associated with higher amounts of CD45⁺ leukocytes and inflammatory LY6C^hi monocytes. Statins reversed the unbalanced Vegfa/Angpt1 expression, normalizing endothelial barrier function at the infarct and blocking the augmented recruitment of inflammatory leukocytes in statin-treated ApoE^-/- mice.

CONCLUSIONS

Statins lowered permeability and reduced the transit of unfavorable inflammatory leukocytes into the infarcted tissue, consequently improving left ventricular outcome.

Enzyme-Targeted Nanoparticles for Delivery to Ischemic Skeletal Muscle

The targeted delivery of enzyme-responsive nanoparticles to specific tissues can be a valuable, minimally invasive approach for imaging or drug delivery applications. In this study, we show for the first time enzyme-directed assembly of intravenously (IV) delivered nanoparticles in ischemic skeletal muscle, which has applications for drug delivery to damaged muscle of the type prevalent in peripheral artery disease (PAD). Specifically, micellar nanoparticles are cleavable by matrix metalloproteinases (MMPs), causing them to undergo a morphological switch and thus aggregate in tissues where these enzymes are upregulated, like ischemic muscle. Here, we demonstrated noninvasive in vivo imaging of these IV-injected nanoparticles through near-infrared dye labeling and in vivo imaging (IVIS) particle tracking in a rat hindlimb ischemia model. Polymer peptide amphiphilic nanoparticles were synthesized and optimized for both MMP cleavage efficiency and near-IR fluorescence. Nanoparticles were injected 4 days after unilateral hindlimb ischemia and were monitored over 28 days using IVIS imaging. Nanoparticles targeted to ischemic muscle over healthy muscle, and ex vivo biodistribution analysis at 7 and 28 days post-injection confirmed targeting to the ischemic muscle as well as off target accumulation in the liver and spleen. Ex vivo histology confirmed particle localization in ischemic but not healthy muscle. Altering the surface charge of the nanoparticles through addition of zwitterionic dye species resulted in improved targeting to the ischemic muscle. To our knowledge, this is the first study to demonstrate the targeted delivery and long term retention of nanoparticles using an enzyme-directed morphology switch. This has implications for noninvasive drug delivery vehicles for treating ischemic muscle, as no minimally invasive, non-surgical options currently exist.

Drug-Loaded Multifunctional Nanoparticles Targeted to the Endocardial Layer of the Injured Heart Modulate Hypertrophic Signaling

Ischemic heart disease is the leading cause of death globally. Severe myocardial ischemia results in a massive loss of myocytes and acute myocardial infarction, the endocardium being the most vulnerable region. At present, current therapeutic lines only ameliorate modestly the quality of life of these patients. Here, an engineered nanocarrier is reported for targeted drug delivery into the endocardial layer of the left ventricle for cardiac repair. Biodegradable porous silicon (PSi) nanoparticles are functionalized with atrial natriuretic peptide (ANP), which is known to be expressed predominantly in the endocardium of the failing heart. The ANP-PSi nanoparticles exhibit improved colloidal stability and enhanced cellular interactions with cardiomyocytes and non-myocytes with minimal toxicity. After confirmation of good retention of the radioisotope 111-Indium in relevant physiological buffers over 4 h, in vivo single-photon emission computed tomography (SPECT/CT) imaging and autoradiography demonstrate increased accumulation of ANP-PSi nanoparticles in the ischemic heart, particularly in the endocardial layer of the left ventricle. Moreover, ANP-PSi nanoparticles loaded with a novel cardioprotective small molecule attenuate hypertrophic signaling in the endocardium, demonstrating cardioprotective potential. These results provide unique insights into the development of nanotherapies targeted to the injured region of the myocardium.