Effect of iron overload on endothelial cell calcification and its mechanism

Coadministration of PEGylated apohemoglobin and haptoglobin can limit vascular dysfunction in the microcirculation and prevent acute inflammation

Unfortunately, during pathological conditions resulting in chronic hemolysis cell-free hemoglobin (Hb) is released into the circulation that releases free heme, resulting in several complications. One approach to prevent these toxicities is the administration of supplemental scavenger proteins, haptoglobin (Hp) and hemopexin (Hpx). The goal of this body of work is to objectively measure the levels of vascular reactivity and inflammatory profiles after an infusion of acellular hemoglobin in animals that were given a coadministration of PEGylated human apohemoglobin (PEG-apoHb), a hemopexin (Hpx)-mimetic that can scavenge free heme from hemoglobin, together with human plasma-derived Hp that can scavenge dimerized Hb. Using intravital microscopy, Golden Syrian hamsters instrumented with a dorsal window chamber were used to evaluate the in vivo effects of four experimental groups that were then challenged with a hypovolemic injection (10% of the animal's blood volume) of human Hb (hHb, 5 g/dL). The four experimental groups consisted of: 1) lactated Ringer's solution (control), 2) PEG-apoHb only, 3) Hp only, and 4) PEG-apoHb + Hp. The microvascular hemodynamics (diameter and flow) in arterioles and venules were recorded at baseline, 20 min after treatment, and 20 min after hHb challenge. Systemic parameters (blood pressure and heart rate), blood gases (pH, Pco2, and Po2), blood parameters (Hb concentration and hematocrit), and multiorgan functionality/inflammation were also measured. Our results suggest that coadministration of PEG-apoHb + Hp as a booster before the infusion of acellular hemoglobin significantly prevented vasoconstriction in the microcirculation, significantly increased the number of functional capillaries, and significantly reduced inflammation.NEW & NOTEWORTHY Coadministration of PEGylated human apohemoglobin (PEG-apoHb)-a hemopexin (Hpx) mimetic that can scavenge free heme-and human plasma-derived haptoglobin (Hp) that can scavenge hemoglobin (Hb), reduces microcirculatory dysfunction and cardiac and kidney inflammation in a Hb-challenge model.

Vascular Calcification: Where is the Cure?

With the progress of aging, the incidence of vascular calcification (VC) gradually increases, which is correlated with cardiovascular events and all-cause death, aggravating global clinical burden. Over the past several decades, accumulating approaches targeting the underlying pathogenesis of VC have provided some possibilities for the treatment of VC. Unfortunately, none of the current interventions have achieved clinical effectiveness on reversing or curing VC. The purpose of this review is to make a summary of novel perspectives on the interventions of VC and provide reference for clinical decision-making.

Advances in the synthesis and applications of macrocyclic polyamines

Macrocyclic polyamines constitute a significant class of macrocyclic compounds that play a pivotal role in the realm of supramolecular chemistry. They find extensive applications across diverse domains including industrial and agricultural production, clinical diagnostics, environmental protection and other multidisciplinary fields. Macrocyclic polyamines possess a distinctive cavity structure with varying sizes, depths, electron-richness degrees and flexibilities. This unique feature enables them to form specific supramolecular structures through complexation with diverse objects, thereby attracting considerable attention from chemists, biologists and materials scientists alike. However, there is currently a lack of comprehensive summaries on the synthesis methods for macrocyclic polyamines. In this review article, we provide an in-depth introduction to the synthesis of macrocyclic polyamines while analysing their respective advantages and disadvantages. Furthermore, we also present an overview of the recent 5-year advancements in using macrocyclic polyamines as non-viral gene vectors, fluorescent probes, diagnostic and therapeutic reagents as well as catalysts. Looking ahead to future research directions on the synthesis and application of macrocyclic polyamines across various fields will hopefully inspire new ideas for their synthesis and use.

Ferroptosis in age-related vascular diseases: Molecular mechanisms and innovative therapeutic strategies

Aging, an inevitable aspect of human existence, serves as one of the predominant risk factors for vascular diseases. Delving into the mystery of vascular disease's pathophysiology, the profound involvement of programmed cell death (PCD) has been extensively demonstrated. PCD is a fundamental biological process that plays a crucial role in both normal physiology and pathology, including a recently discovered form, ferroptosis. Ferroptosis is characterized by its reliance on iron and lipid peroxidation, and its significant involvement in vascular disease pathophysiology has been increasingly acknowledged. This phenomenon not only offers a promising therapeutic target but also deepens our understanding of the complex relationship between ferroptosis and age-related vascular diseases. Consequently, this article aims to thoroughly review the mechanisms that enable the effective control and inhibition of ferroptosis. It focuses on genetic and pharmacological interventions, with the goal of developing innovative therapeutic strategies to combat age-related vascular diseases.

Amyotrophic lateral sclerosis associated disturbance of iron metabolism is blunted by swim training-role of AKT signaling pathway

Swim training has increased the life span of the transgenic animal model of amyotrophic lateral sclerosis (ALS). Conversely, the progress of the disease is associated with the impairment of iron metabolism and insulin signaling. We used transgenic hmSOD1 G93A (ALS model) and non-transgenic mice in the present study. The study was performed on the muscles taken from trained (ONSET and TERMINAL) and untrained animals at three stages of the disease: BEFORE, ONSET, and TERMINAL. In order to study the molecular mechanism of changes in iron metabolism, we used SH-SY5Y and C2C12 cell lines expression vector pcDNA3.1 and transiently transfected with specific siRNAs. The progress of ALS resulted in decreased P-Akt/Akt ratio, which is associated with increased proteins responsible for iron storage ferritin L, ferritin H, PCBP1, and skeletal muscle iron at ONSET. Conversely, proteins responsible for iron export- TAU significantly decrease. The training partially reverses changes in proteins responsible for iron metabolism. AKT silencing in the SH-SY5Y cell line decreased PCBP2 and ferroportin and increased ferritin L, H, PCBP1, TAU, transferrin receptor 1, and APP. Moreover, silencing APP led to an increase in ferritin L and H. Our data suggest that swim training in the mice ALS model is associated with significant changes in iron metabolism related to AKT activity. Down-regulation of AKT mainly upregulates proteins involved in iron import and storage but decreases proteins involved in iron export.

The research progress of crosstalk mechanism of autophagy and apoptosis in diabetic vascular endothelial injury

In recent years, the widespread prevalence of diabetes has become a major killer that threatens the health of people worldwide. Of particular concern is hyperglycemia-induced vascular endothelial injury, which is one of the factors that aggravate diabetic vascular disease. During the process of diabetic vascular endothelial injury, apoptosis is an important pathological manifestation and autophagy is a key regulatory mechanism. Autophagy and apoptosis interact with each other. Hence, the crosstalk mechanism between the two processes is an important means of regulating diabetic vascular endothelial injury. This article reviews the research progress in apoptosis in the context of diabetic vascular endothelial injury and discusses the crosstalk mechanism of autophagy and apoptosis and its role in this injury. The purpose is to guide the prevention and treatment of diabetic vascular endothelial injury in the future.

New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death

Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.

The Complex Relationship between Hypoxia Signaling, Mitochondrial Dysfunction and Inflammation in Calcific Aortic Valve Disease: Insights from the Molecular Mechanisms to Therapeutic Approaches

Calcific aortic valve stenosis (CAVS) is among the most common causes of cardiovascular mortality in an aging population worldwide. The pathomechanisms of CAVS are such a complex and multifactorial process that researchers are still making progress to understand its physiopathology as well as the complex players involved in CAVS pathogenesis. Currently, there is no successful and effective treatment to prevent or slow down the disease. Surgical and transcatheter valve replacement represents the only option available for treating CAVS. Insufficient oxygen availability (hypoxia) has a critical role in the pathogenesis of almost all CVDs. This process is orchestrated by the hallmark transcription factor, hypoxia-inducible factor 1 alpha subunit (HIF-1α), which plays a pivotal role in regulating various target hypoxic genes and metabolic adaptations. Recent studies have shown a great deal of interest in understanding the contribution of HIF-1α in the pathogenesis of CAVS. However, it is deeply intertwined with other major contributors, including sustained inflammation and mitochondrial impairments, which are attributed primarily to CAVS. The present review aims to cover the latest understanding of the complex interplay effect of hypoxia signaling pathways, mitochondrial dysfunction, and inflammation in CAVS. We propose further hypotheses and interconnections on the complexity of these impacts in a perspective of better understanding the pathophysiology. These interplays will be examined considering recent studies that shall help us better dissect the molecular mechanism to enable the design and development of potential future therapeutic approaches that can prevent or slow down CAVS processes.

Impact of Iron overload and Iron Chelation with deferasirox on outcomes of patients with severe aplastic anemia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Patients suffering from severe aplastic anemia (SAA) need frequent blood transfusions during allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, these transfusions can result in an excess of iron in the body tissues, which can negatively impact the success of the transplant.

OBJECTIVES

This study aimed to examine the impact of pre-transplant iron overload (IO) on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with severe aplastic anemia (SAA). It also investigated whether iron chelation (IC) therapy was necessary to enhance transplantation outcomes in SAA patients by providing guidelines for determining when excess iron should be chelated.

STUDY DESIGN

The study consisted of two parts: Cohort 1, which was retrospective and conducted from April 2012 to December 2018, divided SAA patients receiving their first allo-HSCT into two groups based on their pre-transplant serum ferritin (SF) levels: the iron overload (IO) group (SF >1000 ng/ml, n=17) and the non-IO group (SF ≤ 1000 ng/ml, n=48). Cohort 2 was a prospective clinical trial conducted from January 2019 to July 2020. It involved SAA patients diagnosed with IO who were treated with iron chelation (IC) therapy using deferasirox (DFX) at a dose of 10-30 mg/kg. Patients were separated into two groups based on their pre-transplant SF levels: the IC success (IC^success) group (SF ≤ 1000 ng/ml, n=18) and the IC failure (IC^failure) group (SF >1000 ng/ml, n=28) groups. All participants were evaluated for the correlation between pre-transplant SF levels and transplantation outcomes. A P-value of less than 0.05 was considered statistically significant.

RESULTS

There was no significant difference in the speed of engraftment for the three lineages or in the incidence of 100-day grade II-IV acute graft-versus-host disease (aGVHD), grade III-IV aGVHD, or 3-year chronic GVHD between the two groups in both cohorts. However, in cohort 1, it was noteworthy that 1-year OS (83.3% vs. 41.2%, p < 0.001) and 3-year OS (83.3% vs. 35.3%, p < 0.001) were significantly worse in the IO group. Furthermore, 180-day TRM (14.6% vs. 47.1%, p = 0.005) and 1-year TRM (16.7% vs. 52.9%, p = 0.002) were significantly higher in the IO group. The IO group was significantly associated with inferior 3-year OS in both univariate and multivariate analyses. In cohort 2, it was found that 1-year OS (42.9% vs. 88.9%, p = 0.003) and 3-year OS (42.9% vs. 83.3%, p = 0.007) were significantly better in the IC^success group, while 180-day TRM (11.1% vs. 39.3%, p = 0.040) and 1-year TRM (11.1% vs. 57.1%, p = 0.003) were significantly lower in the IC^success group. These differences were confirmed in both univariate and multivariate analyses.

CONCLUSIONS

The study involving two cohorts showed that pre-HSCT iron overload has a negative impact on transplantation outcomes in SAA patients. Chelating excess iron with a serum ferritin level below 1000 ng/ml was found to be necessary and could potentially improve the outcomes.

Vascular calcification: Molecular mechanisms and therapeutic interventions

Vascular calcification (VC) is recognized as a pathological vascular disorder associated with various diseases, such as atherosclerosis, hypertension, aortic valve stenosis, coronary artery disease, diabetes mellitus, as well as chronic kidney disease. Therefore, it is a life-threatening state for human health. There were several studies targeting mechanisms of VC that revealed the importance of vascular smooth muscle cells transdifferentiating, phosphorous and calcium milieu, as well as matrix vesicles on the progress of VC. However, the underlying molecular mechanisms of VC need to be elucidated. Though there is no acknowledged effective therapeutic strategy to reverse or cure VC clinically, recent evidence has proved that VC is not a passive irreversible comorbidity but an active process regulated by many factors. Some available approaches targeting the underlying molecular mechanism provide promising prospects for the therapy of VC. This review aims to summarize the novel findings on molecular mechanisms and therapeutic interventions of VC, including the role of inflammatory responses, endoplasmic reticulum stress, mitochondrial dysfunction, iron homeostasis, metabolic imbalance, and some related signaling pathways on VC progression. We also conclude some recent studies on controversial interventions in the clinical practice of VC, such as calcium channel blockers, renin-angiotensin system inhibitions, statins, bisphosphonates, denosumab, vitamins, and ion conditioning agents.

Ferroptosis of Endothelial Cells in Vascular Diseases

Endothelial cells (ECs) line the inner surface of blood vessels and play a substantial role in vascular biology. Endothelial dysfunction (ED) is strongly correlated with the initiation and progression of many vascular diseases. Regulated cell death, such as ferroptosis, is one of the multiple mechanisms that lead to ED. Ferroptosis is an iron-dependent programmed cell death associated with various vascular diseases, such as cardiovascular, cerebrovascular, and pulmonary vascular diseases. This review summarized ferroptosis of ECs in vascular diseases and discussed potential therapeutic strategies for treating ferroptosis of ECs. In addition to lipid peroxidation inhibitors and iron chelators, a growing body of evidence showed that clinical drugs, natural products, and intervention of noncoding RNAs may also inhibit ferroptosis of ECs.

Eucommia ulmoides Oliver-Tribulus terrestris L. Drug Pair Regulates Ferroptosis by Mediating the Neurovascular-Related Ligand-Receptor Interaction Pathway- A Potential Drug Pair for Treatment Hypertension and Prevention Ischemic Stroke

Background

In this study, we used the network pharmacology approach to explore the potential disease targets of the Eucommia ulmoides Oliver (EUO)-Tribulus terrestris L. (TT) drug pair in the treatment of hypertension-associated neurovascular lesions and IS via the ferroptosis pathway.

Methods

We used the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform to search for the key active compounds and targets of the drug pair. Based on the GeneCards database, the relevant targets for the drug pair were obtained. Then, we performed the molecular docking of the screened core active ingredients and proteins using the DAVID database and the R AutoDock Vina software. Based on the GSE22255 dataset, these screened target proteins were used to build random forest (RF) and support vector machine (SVM) models. Finally, a new IS nomogram prediction model was constructed and evaluated.

Results

There were 36 active compounds in the EUO-TT drug pair. CHRM1, NR3C1, ADRB2, and OPRD1 proteins of the neuroactive ligand-receptor interaction pathway interacted with the proteins related to the ferroptosis pathway. Molecular docking experiments identified 12 active ingredients of the drug pair that may tightly bind to those target proteins. We constructed a visual IS nomogram prediction model using four genes (CHRM1, NR3C1, ADRB2, and OPRD1). The calibration curve, DCA, and clinical impact curves all indicated that the nomogram model is clinically applicable and diagnostically capable. CHRM1, NR3C1, ADRB2, and OPRD1, the target genes of the four effective components of the EUO-TT drug pair, were considered as risk markers for IS.

Conclusions

The active ingredients of EUO-TT drug pair may act on proteins associated with the neuroactive ligand-receptor interaction pathway to regulate ferroptosis in vascular neurons cells, ultimately affecting the onset and progression of hypertension.

Ferroptosis in Cardiovascular Diseases: Current Status, Challenges, and Future Perspectives

Cardiovascular diseases (CVDs) are still a major cause of global mortality and disability, seriously affecting people’s lives. Due to the severity and complexity of these diseases, it is important to find new regulatory mechanisms to treat CVDs. Ferroptosis is a new kind of regulatory cell death currently being investigated. Increasing evidence showed that ferroptosis plays an important role in CVDs, such as in ischemia/reperfusion injury, heart failure, cardiomyopathy, and atherosclerosis. Protecting against CVDs by targeting ferroptosis is a promising approach; therefore, in this review, we summarized the latest regulatory mechanism of ferroptosis and the current studies related to each CVD, followed by critical perspectives on the ferroptotic treatment of CVDs and the future direction of this intriguing biology.