Annexins and cardiovascular diseases: Beyond membrane trafficking and repair

Intramural Administration of Translational Inhibitor Puromycin Upon Balloon Angioplasty Inhibits SMC Proliferation and Protein Synthesis-Vascular Proteome Profiling Analysis

INTRODUCTION

Percutaneous transluminal coronary angioplasty (PTCA) is an effective procedure to decrease the severity of stenotic coronary atherosclerotic lesions. However, its long-term success is limited by the formation of restenosis or neointima by increased proliferation of smooth muscle cells (SMCs) and synthesis of extracellular matrix. Polypeptide growth factors are potent SMC mitogens and are involved in SMC proliferation and extracellular matrix (ECM) synthesis. In this line, inhibition of de novo protein synthesis might be beneficial.

METHODS

We examined the effects of different concentrations of translational inhibitor puromycin on SMC proliferation and apoptosis, in vitro. Further, we examined the effects of local administration of puromycin in a rabbit balloon injury model of the iliac artery.

RESULTS

Injection of puromycin or its vehicle was performed with an infusion-balloon catheter directly into the vessel wall during angioplasty. PTA in the vehicle group resulted in neointima formation 3 weeks after the vascular intervention. In contrast, puromycin treatment resulted in a significant reduction of intima-media ratio. We observed decreased elastin and collagen III synthesis in puromycin-treated animals. With proteomics, we could demonstrate reduced protein expression of lamin, vimentin, alpha-1 antitrypsin, alpha-actin allowing puromycin treatment. In in vitro experiments, puromycin decreased SMCs proliferation (i.e., BrdU incorporation) following FCS stimulation.

PERSPECTIVE

Based on the data from our animal experiments, aministration of puromycin directly into the vessel wall during angioplasty may be effective in preventing or reducing restenosis in humans.

Annexin A5 knockdown inhibits cardiomyocyte apoptosis and alleviates cardiac hypertrophy via activating the PI3K/AKT/Bcl-2 signaling pathway

Annexin A5 (ANXA5) is a small calcium-dependent protein that binds specifically to negatively charged phosphatidylserine as a marker of apoptosis. Previous studies have shown that ANXA5 expression is elevated in hypertensive patients and is closely related to left ventricular systolic function in hypertensive patients, but its specific mechanism of action has not been clarified. GEO database analysis showed that ANXA5 expression was significantly upregulated in hypertensive myocardial hypertrophy. The expression of ANXA5 protein and mRNA was overexpressed, and knockdown of ANXA5 can effectively attenuate cardiomyocyte apoptosis and inflammatory response, ameliorate myocardial hypertrophy and cardiac dysfunction in ALD-induced hypertrophic cardiomyocytes and in SHR hypertrophic hearts. Mechanistically, ANXA5 has synergistic effect with intracellular calciumion level. In the meantime, ANXA5 knockdown inhibited cell apoptosis along with a decrease of Bax/Bcl-2 ratio, and induction of PI3K/AKT activation. It should be noted that LY290004 (PI3K/Akt signaling pathway inhibitor) can weaken the inhibitory effect of knockdown ANXA5 on cardiomyocyte apoptosis and myocardial protection. Therefore, ANXA5 knockdown improves hypertensive myocardial hypertrophy and cardiac function by inhibiting apoptosis and inflammatory response and activating PI3K/AKT/Bcl-2 pathway, ANXA5 may be a potential therapeutic direction for the treatment of hypertensive myocardial hypertrophy.

Identification of Disease-Relevant, Sex-Based Proteomic Differences in iPSC-Derived Vascular Smooth Muscle Cells

The prevalence of cardiovascular disease varies with sex, and the impact of intrinsic sex-based differences on vasculature is not well understood. Animal models can provide important insights into some aspects of human biology; however, not all discoveries in animal systems translate well to humans. To explore the impact of chromosomal sex on proteomic phenotypes, we used iPSC-derived vascular smooth muscle cells from healthy donors of both sexes to identify sex-based proteomic differences and their possible effects on cardiovascular pathophysiology. Our analysis confirmed that differentiated cells have a proteomic profile more similar to healthy primary aortic smooth muscle cells than iPSCs. We also identified sex-based differences in iPSC-derived vascular smooth muscle cells in pathways related to ATP binding, glycogen metabolic process, and cadherin binding as well as multiple proteins relevant to cardiovascular pathophysiology and disease. Additionally, we explored the role of autosomal and sex chromosomes in protein regulation, identifying that proteins on autosomal chromosomes also show sex-based regulation that may affect the protein expression of proteins from autosomal chromosomes. This work supports the biological relevance of iPSC-derived vascular smooth muscle cells as a model for disease, and further exploration of the pathways identified here can lead to the discovery of sex-specific pharmacological targets for cardiovascular disease.

Single chain fragment variable, a new theranostic approach for cardiovascular diseases

Cardiovascular diseases (CVDs) remain a significant global health challenge, leading to substantial morbidity and mortality. Despite recent advancements in CVD management, pharmaceutical treatments often suffer from poor pharmacokinetics and high toxicity. With the rapid progress of modern molecular biology and immunology, however, single-chain fragment variable (scFv) molecule engineering has emerged as a promising theranostic tool to offer specificity and versatility in targeting CVD-related antigens. To represent the latest development on the potential of scFv in the context of CVDs, this review summarized the new mechanism of action and applications as therapeutic, as well as diagnostic agents. Furthermore, the advantages of scFv, including its small size, ease of modification, and ability to be engineered for enhanced affinity and specificity, are also described. Finally, such challenges as immunogenicity, stability, and scalability, alongside strategies to overcome these hurdles, are deeply scrutinized to provide safer and more effective strategies for the diagnosis and treatment of the incurable CVDs.

The Potential Contribution of MyomiRs miR-133a-3p, -133b, and -206 Dysregulation in Cardiovascular Disease Risk

Cardiovascular disease (CVD) is a major global health concern. The number of people with CVD is expected to rise due to aging populations and increasing risk factors such as obesity and diabetes. Identifying new molecular markers is crucial for early diagnosis and treatment. Among these, plasma levels of some miRNAs, specifically expressed in cardiac and skeletal muscle, known as myomiRs, have gained attention for their roles in cardiovascular health. This study analyzed the plasma levels of miR-133a-3p, -133b, and -206 in the pathogenesis of cardiovascular diseases. Using a case-control study design with patients recruited from several nursing homes from Calabria (southern Italy) characterized by different types of CVD compared with non-CVD controls, we found downregulation of miR-133a-3p in heart failure and miR-133b in stroke, along with the overall decreased expression of miR-133b and miR-206 in CVD patients, although they showed low specificity as biomarkers of CVD (as based on ROC analysis). In silico functional characterization of their targets and signaling pathways revealed their involvement in critical cardiovascular processes. Although further research is necessary to fully elucidate their mechanisms and clinical utility, the findings reported here may provide insight into the potential contribution of myomiRs in the cardiovascular injury framework, also offering indications for new research directions.

A systematic review and in silico analysis of studies investigating the ischemic penumbra proteome in animal models of experimental stroke

Ischaemic stroke results in the formation of a cerebral infarction bordered by an ischaemic penumbra. Characterising the proteins within the ischaemic penumbra may identify neuro-protective targets and novel circulating markers to improve patient care. This review assessed data from studies using proteomic platforms to compare ischaemic penumbra tissues to controls following experimental stroke in animal models. Proteins reported to differ significantly between penumbra and control tissues were analysed in silico to identify protein-protein interactions and over-represented pathways. Sixteen studies using rat (n = 12), mouse (n = 2) or primate (n = 2) models were included. Heterogeneity in the design of the studies and definition of the penumbra were observed. Analyses showed high abundance of p53 in the penumbra within 24 hours of permanent ischaemic stroke and was implicated in driving apoptosis, cell cycle progression, and ATM- MAPK- and p53- signalling. Between 1 and 7 days after stroke there were changes in the abundance of proteins involved in the complement and coagulation pathways. Favourable recovery 1 month after stroke was associated with an increase in the abundance of proteins involved in wound healing. Poor recovery was associated with increases in prostaglandin signalling. Findings suggest that p53 may be a target for novel therapeutics for ischaemic stroke.

Pathobiology of Fungal Endophthalmitis: A Major Review

Fungal endophthalmitis is a chronic inflammatory condition of the eye's posterior segment that can lead to irreversible vision loss. While relatively rare in western countries, its incidence is notably higher in Asia, particularly India. The condition's prevalence is exacerbated by factors such as intravenous drug use, antibiotics, and ocular surgeries. Fungal endophthalmitis can be categorized as endogenous, arising from systemic infection, or exogenous, linked to external sources such as trauma or surgery. The fungal agents responsible vary by region, with Candida species common in the West and Aspergillus and Fusarium species more prevalent in India. Management typically involves vitrectomy and intravitreal antifungal drugs such as amphotericin B and voriconazole, though treatment is often complicated by multidrug resistance and culture-negative cases. Recent proteomic and transcriptomic analyses have highlighted the early and sustained activation of the host immune response during infection involving key inflammatory and oxidative stress-related proteins. Given the potential for excessive inflammation to cause retinal damage, targeted immunotherapies are crucial. Immunomodulation, which aims to balance the immune response, shows promise in preserving vision while effectively combating the infection. Key targets for immunomodulation include pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-17), chemokines (CCL2, CXCL8), Toll-like receptors (TLR2, TLR4), and the complement system. Additionally, modulating the activity of macrophages, neutrophils, regulatory T cells, and Th17 cells, as well as targeting inflammasomes, can help control inflammation. Biologic agents and small molecule inhibitors offer further avenues for precise immune response modulation. This review underscores the importance of a comprehensive understanding of host-pathogen interactions in the development of effective therapies for fungal endophthalmitis.

Identification of Disease-relevant, Sex-based Proteomic Differences in iPSC-derived Vascular Smooth Muscle

The prevalence of cardiovascular disease varies with sex, and the impact of intrinsic sex-based differences on vasculature is not well understood. Animal models can provide important insight into some aspects of human biology, however not all discoveries in animal systems translate well to humans. To explore the impact of chromosomal sex on proteomic phenotypes, we used iPSC-derived vascular smooth muscle cells from healthy donors of both sexes to identify sex-based proteomic differences and their possible effects on cardiovascular pathophysiology. Our analysis confirmed that differentiated cells have a proteomic profile more similar to healthy primary aortic smooth muscle than iPSCs. We also identified sex-based differences in iPSC- derived vascular smooth muscle in pathways related to ATP binding, glycogen metabolic process, and cadherin binding as well as multiple proteins relevant to cardiovascular pathophysiology and disease. Additionally, we explored the role of autosomal and sex chromosomes in protein regulation, identifying that proteins on autosomal chromosomes also show sex-based regulation that may affect the protein expression of proteins from autosomal chromosomes. This work supports the biological relevance of iPSC-derived vascular smooth muscle cells as a model for disease, and further exploration of the pathways identified here can lead to the discovery of sex-specific pharmacological targets for cardiovascular disease.

Significance

In this work, we have differentiated 4 male and 4 female iPSC lines into vascular smooth muscle cells, giving us the ability to identify statistically-significant sex-specific proteomic markers that are relevant to cardiovascular disease risk (such as PCK2, MTOR, IGFBP2, PTGR2, and SULTE1).

Limb connective tissue is organized in a continuum of promiscuous fibroblast identities during development

Connective tissue (CT), which includes tendon and muscle CT, plays critical roles in development, in particular as positional cue provider. Nonetheless, our understanding of fibroblast developmental programs is hampered because fibroblasts are highly heterogeneous and poorly characterized. Combining single-cell RNA-sequencing-based strategies including trajectory inference and in situ hybridization analyses, we address the diversity of fibroblasts and their developmental trajectories during chicken limb fetal development. We show that fibroblasts switch from a positional information to a lineage diversification program at the fetal period onset. Muscle CT and tendon are composed of several fibroblast populations that emerge asynchronously. Once the final muscle pattern is set, transcriptionally close populations are found in neighboring locations in limbs, prefiguring the adult fibroblast layers. We propose that the limb CT is organized in a continuum of promiscuous fibroblast identities, allowing for the robust and efficient connection of muscle to bone and skin.

Mechanisms of Endothelial Cell Membrane Repair: Progress and Perspectives

Endothelial cells are the crucial inner lining of blood vessels, which are pivotal in vascular homeostasis and integrity. However, these cells are perpetually subjected to a myriad of mechanical, chemical, and biological stresses that can compromise their plasma membranes. A sophisticated repair system involving key molecules, such as calcium, annexins, dysferlin, and MG53, is essential for maintaining endothelial viability. These components orchestrate complex mechanisms, including exocytosis and endocytosis, to repair membrane disruptions. Dysfunctions in this repair machinery, often exacerbated by aging, are linked to endothelial cell death, subsequently contributing to the onset of atherosclerosis and the progression of cardiovascular diseases (CVD) and stroke, major causes of mortality in the United States. Thus, identifying the core machinery for endothelial cell membrane repair is critically important for understanding the pathogenesis of CVD and stroke and developing novel therapeutic strategies for combating CVD and stroke. This review summarizes the recent advances in understanding the mechanisms of endothelial cell membrane repair. The future directions of this research area are also highlighted.

Catch Bond-Mediated Adhesion Drives Staphylococcus aureus Host Cell Invasion

Various viruses and pathogenic bacteria interact with annexin A2 to invade mammalian cells. Here, we show that Staphylococcus aureus engages in extremely strong catch bonds for host cell invasion. By means of single-molecule atomic force microscopy, we find that bacterial surface-located clumping factors bind annexin A2 with extraordinary strength, indicating that these bonds are extremely resilient to mechanical tension. By determining the lifetimes of the complexes under increasing mechanical stress, we demonstrate that the adhesins form catch bonds with their ligand that are capable to sustain forces of 1500-1700 pN. The force-dependent adhesion mechanism identified here provides a molecular framework to explain how S. aureus pathogens tightly attach to host cells during invasion and shows promise for the design of new therapeutics against intracellular S. aureus.

Entrectinib for NTRK Fusion-Positive Metastatic Melanoma Progressing on Combined PD-1 and CTLA-4 Inhibition: A Case Report

Introduction

The burden of melanoma is increasing globally. Despite the use of immunotherapy and targeted therapy, the prognosis of metastatic melanoma remains relatively poor. The integration of comprehensive molecular profiling can lead to the detection of actionable biomarkers and the expansion of treatment options, thereby prolonging cancer patient survival.

Case Presentation

We herein present the case of a female 54-year-old patient diagnosed with melanoma of the right knee, for which she underwent surgery. Patient showed progression of disease after 10 cycles of adjuvant nivolumab. Ipilimumab (1 mg/kg every 3 weeks) was added to the treatment regimen but no clinical improvement was observed. Molecular profiling was conducted based on patient tissue, and an ANXA2-NTRK3 fusion was detected in the tumor. This specific fusion has not been previously reported; however, it is in-frame and similar to other known oncogenic NTRK fusions. At the time of entrectinib initiation, the patient had clear disease progression on the right leg on standard of care immunotherapy. She was commenced on entrectinib 200 mg once daily for 2 weeks. Dose escalation was attempted, and treatment intensity was managed based on drug tolerability. Good treatment response was observed on laboratory and radiologic parameters. As of September 2023, i.e., 2.5 years after treatment initiation, patient disease continues to be controlled with entrectinib.

Conclusion

Profiling of advanced tumors is important to determine the presence of agnostic markers that can be targeted and ultimately improve the prognostic outcome of patients after the failure of standard of care.