Anti-Thrombotic Effects of Artesunate through Regulation of cAMP and PI3K/MAPK Pathway on Human Platelets

Current research on mitochondria‑associated membranes in cardiovascular diseases (Review)

The present study aimed to explore the role of mitochondria‑associated membranes (MAMs) as a key interface between mitochondria and the endoplasmic reticulum (ER) and to evaluate their importance in maintaining the physiological functions of these two organelles. MAMs not only act as a structural bridge between mitochondria and the ER but also widely participate in the regulation of mitochondrial biosynthesis and function, Ca2+ signal transduction, lipid metabolism, oxidative stress response and autophagy. In addition, the specific protein composition of MAMs is increasingly being recognized as having a profound impact on their function, and these proteins play a central role in regulating intercellular communication. Recently, the scientific community has accumulated a large amount of evidence supporting MAMs as potential targets for cardiovascular disease treatment. The present review focuses on the fine structure and multifunctional properties of MAMs and their mechanisms in the occurrence and development of cardiovascular diseases. The goal is to explore the mechanism of MAMs, therapeutic intervention points directly related to cardiovascular diseases, and feasibility of incorporating MAMs into the diagnostic strategy and treatment plan of cardiovascular diseases to provide novel insights and theoretical support for clinical practice in this field. MAMs have great potential as therapeutic targets for various cardiovascular diseases. This finding not only deepens the understanding of the interaction between organelles but also opens up a promising research path for the development of new therapeutic strategies for cardiovascular diseases.

TRAP-Induced Platelet Reactivity Is Inhibited by Omega-3 Fatty Acid-Derived Prostaglandin E3 (PGE3)

Background: Prostaglandins are naturally occurring local mediators that can participate in the modulation of the cardiovascular system through their interaction with Gs/Gi-coupled receptors in different tissues and cells, including platelets. Thrombin is one of the most important factors that regulates platelet reactivity and coagulation. Clinical trials have consistently shown that omega-3 fatty acid supplementation lowers the risk for cardiovascular mortality and morbidity. Since omega-3 fatty acids are the main precursors of PGE3 in vivo, it would be relevant to investigate the effects of PGE3 on Thrombin Receptor Activating Peptide (TRAP-6)-induced platelet reactivity to determine the receptors and possible mechanisms of action of these compounds. Methods: We have measured platelet aggregation, P-selectin expression, and vasodilator-stimulated phosphoprotein (VASP) phosphorylation to evaluate platelet reactivity induced by TRAP-6 to determine the effects of PGE3 on platelet function. Results: We assessed the ability of DG-041, a selective prostanoid EP3 receptor antagonist, and of ONO-AE3-208, a selective prostanoid EP4 receptor antagonist, to modify the effects of PGE3. PGE3 inhibited TRAP-6-induced platelet aggregation and activation. This inhibition was enhanced in the presence of a Gi-coupled EP3 receptor antagonist and abolished in the presence of a Gs-coupled EP4 receptor antagonist. The effects of PGE3 were directly related to changes in cAMP, assessed by VASP phosphorylation. Conclusions: The general effects of PGE3 on human platelet reactivity are the consequence of a balance between activatory and inhibitory effects at receptors that have contrary effects on adenylate cyclase. These results indicate a potential mechanism by which omega-3 fatty acids underlie cardioprotective effects.

The multifaceted potential of TPT1 as biomarker and therapeutic target

Tumor Protein Translationally-Controlled 1 (TPT1) is a highly conserved gene found across eukaryotic species. The protein encoded by TPT1 is ubiquitously expressed both intracellularly and extracellularly across various tissues, and its levels are influenced by various external factors. TPT1 interacts with several key proteins, including p53, MCL1, and immunoglobulins, highlighting its crucial role in cellular processes. The dysregulation of TPT1 expression has been documented in a wide range of diseases, indicating its potential as a valuable biomarker. Additionally, targeting TPT1 presents a promising approach for treating and preventing various conditions. This review will assess the potential of TPT1 as a biomarker and evaluate the effectiveness of current strategies designed to inhibit TPT1 in disease contexts.

How Protein Depletion Balances Thrombosis and Bleeding Risk in the Context of Platelet's Activatory and Negative Signaling

Platelets are small cell fragments that play a crucial role in hemostasis, requiring fast response times and fine signaling pathway regulation. For this regulation, platelets require a balance between two pathway types: the activatory and negative signaling pathways. Activatory signaling mediators are positive responses that enhance stimuli initiated by a receptor in the platelet membrane. Negative signaling regulates and controls the responses downstream of the same receptors to roll back or even avoid spontaneous thrombotic events. Several blood-related pathologies can be observed when these processes are unregulated, such as massive bleeding in activatory signaling inhibition or thrombotic events for negative signaling inhibition. The study of each protein and metabolite in isolation does not help to understand the role of the protein or how it can be contrasted; however, understanding the balance between active and negative signaling could help develop effective therapies to prevent thrombotic events and bleeding disorders.

Can artemisinin and its derivatives treat malaria in a host-directed manner?

Malaria is caused by an apicomplexan protozoan parasite, Plasmodium, and is transmitted through vectors. It remains a substantial health burden, especially in developing countries, leading to significant socioeconomic losses. Although the World Health Organization (WHO) has approved various antimalarial medications in the past two decades, the increasing resistance to these medications has worsened the situation. The development of drug resistance stems from genetic diversity among Plasmodium strains, impeding eradication efforts. Consequently, exploring innovative technologies and strategies for developing effective medications based on the host is crucial. Artemisinin and its derivatives (artemisinins) have been recommended by the WHO for treating malaria owing to their known effectiveness in killing the parasite. However, their potential to target the host for malaria treatment has not been investigated. This article concisely reviews the application of host-directed therapeutics, potential drug candidates targeting the host for treating malaria, and usage of artemisinins in numerous diseases. It underscores the importance of host-directed interventions for individuals susceptible to malaria, suggests the potential utility of artemisinins in host-directed malaria treatments, and posits that the modulation of host proteins with artemisinins may offer a means of intervening in host-parasite interactions. Further studies focusing on the host-targeting perspective of artemisinins can provide new insights into the mechanisms of artemisinin resistance and offer a unique opportunity for new antimalarial drug discovery.

Molecular Insights into the Relationship Between Platelet Activation and Endothelial Dysfunction: Molecular Approaches and Clinical Practice

Platelets are one of the coagulation cells. When platelet activation occurs, many mediators are released and affect endothelial cells (ECs) and lead to endothelial dysfunction (ED). ED plays an important role in the pathogenesis of many diseases, including cardiovascular disease (CVD). Platelet are of important factors in ED. The release of mediators by platelets causes the stimulation of inflammatory pathways, oxidative stress, and apoptosis, which ultimately result in ED.On the other hand, platelet activation in CVD patients can be associated with a bad prognosis. Platelet activation can increase the level of markers such as p-selectin in the serum. Also, in this study, we have discussed the role of platelet as a diagnostic factor, as well as its use as a treatment option. In addition, we discussed some of the molecular pathways that are used to target platelet activation.

Carbonized Platycladus orientalis Derived Carbon Dots Accelerate Hemostasis through Activation of Platelets and Coagulation Pathways

Achieving rapid and effective hemostasis remains a multidisciplinary challenge. Here, distinctive functional carbon dots derived from carbonized Platycladus orientalis (CPO-CDs) are developed using one-step hydrothermal method. The negatively charged surface of CPO-CDs retains partial functional groups from CPO precursor, exhibiting excellent water solubility and high biocompatibility. Both rat liver injury model and tail amputation model have confirmed the rapid and effective hemostatic performance of CPO-CDs on exogenous hemorrhage. Further, on endogenous blood-heat hemorrhage syndrome rat model, CPO-CDs could inhibit hemorrhage and alleviate inflammation response. Interestingly, the excellent hemostasis performance of CPO-CDs is ascribed to activate exogenous coagulation pathway and common coagulation pathway. More importantly, metabolomics of rat plasma suggests that the hemostasis effect of CPO-CDs is closely related to platelet functions. Therefore, the designed in vitro experiments are performed and it is discovered that CPO-CDs significantly promote platelets adhesion, activation, and aggregation. Further, the underlying mechanism investigation suggests that Src/Syk signal pathway plays a key role in platelets activation triggered by CPO-CDs. Overall, CPO-CDs with rapid and excellent hemostatic performance are discovered for the first time, which could be an excellent candidate for the treatment of hemorrhagic diseases.

Daidzein Inhibits Human Platelet Activation by Downregulating Thromboxane A2 Production and Granule Release, Regardless of COX-1 Activity

Platelets play crucial roles in cardiovascular diseases (CVDs) by regulating hemostasis and blood coagulation at sites of blood vessel damage. Accumulating evidence indicates daidzein inhibits platelet activation, but the mechanism involved has not been elucidated. Thus, in this study, we investigated the mechanism responsible for the inhibition of collagen-induced platelet aggregation by daidzein. We found that in collagen-induced platelets, daidzein suppressed the production of thromboxane A2 (TXA2), a molecule involved in platelet activation and aggregation, by inhibiting the cytosolic phospholipase A2 (cPLA2) signaling pathway. However, daidzein did not affect cyclooxygenase-1 (COX-1). Furthermore, daidzein attenuated the PI3K/PDK1/Akt/GSK3αβ and MAPK (p38, ERK) signaling pathways, increased the phosphorylation of inositol trisphosphate receptor1 (IP3R1) and vasodilator-stimulated phosphoprotein (VASP), and increased the level of cyclic adenosine monophosphate (cAMP). These results suggest that daidzein inhibits granule release (ATP, serotonin, P-selectin), integrin αIIbβ3 activation, and clot retraction. Taken together, our study demonstrates that daidzein inhibits collagen-induced platelet aggregation and suggests that daidzein has therapeutic potential for the treatment of platelet aggregation-related diseases such as atherosclerosis and thrombosis.

Molecular insights into artemisinin resistance in Plasmodium falciparum: An updated review

Malaria still poses a major burden on human health around the world, especially in endemic areas. Plasmodium resistance to several antimalarial drugs has been one of the major hindrances in control of malaria. Thus, the World Health Organization recommended artemisinin-based combination therapy (ACT) as a front-line treatment for malaria. The emergence of parasites resistant to artemisinin, along with resistant to ACT partner drugs, has led to ACT treatment failure. The artemisinin resistance is mostly related to the mutations in the propeller domain of the kelch13 (k13) gene that encodes protein Kelch13 (K13). The K13 protein has an important role in parasite reaction to oxidative stress. The most widely spread mutation in K13, with the highest degree of resistance, is a C580Y mutation. Other mutations, which are already identified as markers of artemisinin resistance, are R539T, I543T, and Y493H. The objective of this review is to provide current molecular insights into artemisinin resistance in Plasmodium falciparum. The trending use of artemisinin beyond its antimalarial effect is described. Immediate challenges and future research directions are discussed. Better understanding of the molecular mechanisms underlying artemisinin resistance will accelerate implementation of scientific findings to solve problems with malarial infection.

Artesunate inhibits PDE4 leading to intracellular cAMP accumulation, reduced ERK/MAPK signaling, and blockade of influenza A virus vRNP nuclear export

Influenza A viruses (IAV) have been a major cause of mortality. Given the potential for future deadly pandemics, effective drugs are needed for the treatment of severe influenzas, such as those caused by H5N1 IAV. The anti-malaria drugs artemisinin and its derivates, including artesunate (AS), have been reported to have broad antiviral activities. Here, we showed AS's antiviral activity against H5N1, H1N1, H3N2 and oseltamivir-resistant influenza A(H1N1)virus in vitro. Moreover, we showed that AS treatment significantly protected mice from lethal challenges with H1N1 and H5N1 IAV. Strikingly, the combination of AS and peramivir treatment significantly improved survival outcomes compared to their monotherapy with either AS or peramivir. Furthermore, we demonstrated mechanistically that AS affected the later stages of IAV replication and limited nuclear export of viral ribonucleoprotein (vRNP) complexes. In A549 cells, we demonstrated for the first time that AS treatment induced cAMP accumulation via inhibiting PDE4, and consequently reduced ERK phosphorylation and blocked IAV vRNP export, and thus suppressed IAV replication. These AS's effects were reversed by the pre-treatment with a cAMP inhibitor SQ22536. Our findings suggest that AS could serve as a novel IAV inhibitor by interfering vRNP nuclear export to prevent and treat IAV infection.

Chemical Constituents and Bioactive Principles from the Mexican Truffle and Fermented Products of the Derived Fungus Ustilago maydis MZ496986

To look in-depth into the traditional Mexican truffle, this study investigated the phytochemical and pharmacological properties of field-collected corn galls and the fermentate of its pathogen Ustilago maydis MZ496986. Here, we established the chemical profiles of both materials via the gradient HPLC-UV method and successfully identified six previously unreported chemical entities, ustilagols A-F (1-6), and 17 known components. Compounds 3, 5, and 9 exhibited potent nitric oxide production inhibitory activities in murine brain microglial BV-2 cells (IC₅₀ = 6.7 ± 0.5, 5.8 ± 0.9, and 3.9 ± 0.1 μM) without cytotoxic effects. DIMBOA (9) also attenuates lipopolysaccharide (LPS)-stimulated NF-κB activation in RAW 264.7 macrophages (IC₅₀ = 58.1 ± 7.2 μM). Ustilagol G (7) showed potent antiplatelet aggregation in U46619-stimulated human platelets (IC₅₀ = 16.5 ± 5.3 μM). These findings highlighted the potential of corn galls and U. maydis MZ496986 fermentate as functional foods for improving inflammation-related discomforts and vascular obstruction.