MTH1 protects platelet mitochondria from oxidative damage and regulates platelet function and thrombosis

OGG1: An emerging multifunctional therapeutic target for the treatment of diseases caused by oxidative DNA damage

Oxidative DNA damage-related diseases, such as incurable inflammation, malignant tumors, and age-related disorders, present significant challenges in modern medicine due to their complex molecular mechanisms and limitations in identifying effective treatment targets. Recently, 8-oxoguanine DNA glycosylase 1 (OGG1) has emerged as a promising multifunctional therapeutic target for the treatment of these challenging diseases. In this review, we systematically summarize the multiple functions and mechanisms of OGG1, including pro-inflammatory, tumorigenic, and aging regulatory mechanisms. We also highlight the potential of OGG1 inhibitors and activators as potent therapeutic agents for the aforementioned life-limiting diseases. We conclude that OGG1 serves as a multifunctional hub; the inhibition of OGG1 may provide a novel approach for preventing and treating inflammation and cancer, and the activation of OGG1 could be a strategy for preventing age-related disorders. Furthermore, we provide an extensive overview of successful applications of OGG1 regulation in treating inflammatory, cancerous, and aging-related diseases. Finally, we discuss the current challenges and future directions of OGG1 as an emerging multifunctional therapeutic marker for the aforementioned challenging diseases. The aim of this review is to provide a robust reference for scientific researchers and clinical drug developers in the development of novel clinical targeted drugs for life-limiting diseases, especially for incurable inflammation, malignant tumors, and age-related disorders.

Polo-like kinase 2 promotes microglial activation via regulation of the HSP90α/IKKβ pathway

Polo-like kinase 2 (PLK2) is a serine/threonine protein kinase associated with the regulation of synaptic plasticity and centriole duplication. We identify PLK2 as a crucial early-response gene in lipopolysaccharide (LPS)-stimulated microglial cells. Knockdown or inhibition of PLK2 remarkably attenuates LPS-induced expression of proinflammatory factors in microglial cells by suppressing the inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ)-nuclear factor (NF)-κB signaling pathway. We identify heat shock protein 90 alpha (HSP90α), a regulator of IKKβ activity, as a novel PLK2 substrate. Knockdown or pharmacological inhibition of HSP90α abolishes PLK2-mediated activation of NF-κB transcriptional activity and microglial inflammatory activation. Furthermore, phosphoproteomic analysis pinpoints Ser252 and Ser263 on HSP90α as novel phosphorylation targets of PLK2. Lastly, conditional knockout of PLK2 in microglial cells dramatically ameliorates neuroinflammation and subsequent dopaminergic neuron loss in an intracranial LPS-induced mouse Parkinson's disease (PD) model. The present study reveals that PLK2 promotes microglial activation through the phosphorylation of HSP90α and subsequent activation of the IKKβ-NF-κB signaling pathway.

Recent advances of lipid droplet-targeted AIE-active materials for imaging, diagnosis and therapy

Lipid droplets (LDs) are cellular organelles specialized in the storage and regulating the release of lipids critical for energy metabolism. As investigation on LDs deepens, the complex biological functions of LDs are revealed and their relationships with various diseases such as atherosclerosis, fatty liver, obesity, and cancer are uncovered. Fluorescence-based techniques with simple operations, visible results and high non-invasiveness are ideal tools for investigating LD-related biological processes and diseases. Materials with aggregation-induced emission (AIE) characteristics have emerged as promising candidates for investigating LDs due to their high signal-to-noise ratio (S/N), strong photostability, and large Stokes shift. This review discusses the principles and advantages of LD-targeting AIE probes for imaging LDs, diagnosis of LD-associated diseases including atherosclerotic plaques, liver diseases, acute kidney diseases and cancer, therapies with LD-targeting AIE-active photosensitizers and other relevant fields in the past five years. Through typical examples, we illustrate the status of investigating LD-related imaging, diagnosis of diseases and therapy with AIE materials. This review is expected to attract attentions from scientists with different research backgrounds and contribute to the further development of LD-targeting AIE materials.

An Oxidative Stress Nano-Amplifier for Improved Tumor Elimination and Combined Immunotherapy

Amplifying oxidative stress to disrupt intracellular redox homeostasis can accelerate tumor cell death. In this work, an oxidative stress amplifier (PP@T) is prepared for enhanced tumor oxidation therapy to reduce tumor growth and metastases. The nano-amplifier has been successfully constructed by embedding MTH1 inhibitor (TH588) in the PDA-coated porphyrin metal-organic framework PCN-224. The controllable-released TH588 is demonstrated from pores can hinder MTH1-mediated damage-repairing process by preventing the hydrolysis of 8-oxo-dG, thereby amplifying oxidative stress and exacerbating the oxidative DNA damage induced by the sonodynamic therapy of PP@T under ultrasound irradiation. Furthermore, PP@T can effectively induce immunogenic cell death to trigger systemic anti-tumor immune response. When administered in combination with immune checkpoint blockade, PP@T not only impedes the progression of the primary tumor but also achieves obvious antimetastasis in breast cancer murine models, including orthotopic and artificial whole-body metastasis models. Furthermore, the nanoplatform also provides photoacoustic imaging for in vivo treatment guidance. In conclusion, by amplifying oxidative stress and reactive oxygen species sensitized immunotherapy, this image-guided nanosystem shows potential for highly specific, effective combined therapy against tumor cells with negligible side-effects to normal cells which will provide a new insight for precise tumor treatment.

8-OxodG: A Potential Biomarker for Chronic Oxidative Stress Induced by High-LET Radiation

Oxidative stress-mediated biomolecular damage is a characteristic feature of ionizing radiation (IR) injury, leading to genomic instability and chronic health implications. Specifically, a dose- and linear energy transfer (LET)-dependent persistent increase in oxidative DNA damage has been reported in many tissues and biofluids months after IR exposure. Contrary to low-LET photon radiation, high-LET IR exposure is known to cause significantly higher accumulations of DNA damage, even at sublethal doses, compared to low-LET IR. High-LET IR is prevalent in the deep space environment (i.e., beyond Earth's magnetosphere), and its exposure could potentially impair astronauts' health. Therefore, the development of biomarkers to assess and monitor the levels of oxidative DNA damage can aid in the early detection of health risks and would also allow timely intervention. Among the recognized biomarkers of oxidative DNA damage, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OxodG) has emerged as a promising candidate, indicative of chronic oxidative stress. It has been reported to exhibit differing levels following equivalent doses of low- and high-LET IR. This review discusses 8-OxodG as a potential biomarker of high-LET radiation-induced chronic stress, with special emphasis on its potential sources, formation, repair mechanisms, and detection methods. Furthermore, this review addresses the pathobiological implications of high-LET IR exposure and its association with 8-OxodG. Understanding the association between high-LET IR exposure-induced chronic oxidative stress, systemic levels of 8-OxodG, and their potential health risks can provide a framework for developing a comprehensive health monitoring biomarker system to safeguard the well-being of astronauts during space missions and optimize long-term health outcomes.

Nervonic acid triggered ovarian inflammation by inducing mitochondrial oxidative stress to activate NLRP3/ IL-1β pathway

INTRODUCTION

Metabolic syndrome is a serious public health concern across the globe. However, the typical metabolites and mechanisms underlying the decreased fertility related to metabolic syndrome is still elusive.

OBJECTIVES

The aim of the present study was to explore the typical metabolites and mechanisms underlying the decreased fertility related with metabolic syndrome.

METHODS

Utilizing metabolomics, a comparative analysis was conducted on fatty acid compositions in various tissues of sows with high and low reproductive performance. Additionally, serum fatty acid compositions in a metabolic syndrome model (obese mice) induced by a high-fat diet (HFD) were investigated to elucidate the lipid metabolites associated with metabolic syndrome. Furthermore, the impact of nervonic acid (NA) on ovarian function was examined using rodent animal models (rats and mice). Through biological techniques such as transcriptomics, CUT&Tag, and analysis of post-translational protein modifications, the molecular mechanisms underlying NA mediated ovarian inflammation were further elucidated based on models utilizing ovarian granulosa cells from pigs, humans, and mice. Finally, validation was performed on ovaries from patients diagnosed with polycystic ovary syndrome.

RESULTS

In vitro, targeted serum lipidomic analysis revealed that sows with low embryo survival rates exhibited abnormal lipid metabolism characterized by abnormal accumulation of NA in the liver, ovary, and adipose tissue. Additionally, elevated NA levels trigger ovarian inflammation to cause ovarian dysfunction in both sows and rats. Mechanistically, NA induce mitochondrial oxidative stress through inhibiting respiratory chain proteins CYTB and NDFUB8 to activate NLRP3 inflammasome, which triggers procaspase-1 into active caspase-1, and convert the cytokine precursors pro-IL-1β into biologically active IL-1β in ovarian granulosa cells. Notably, we evidenced that NA promotes IL-1β activities by increasing H3K9ac modification level of IL-1β promoter regions and regulating the expression of the transcription factor AP-1. Finally, we found that the decreased expression of CerS2 in ovaries and the increased level of chemokine CXCL14 may be the cause of abnormal NA accumulation. Surprisingly, individuals with polycystic ovary syndrome, obesity, non-alcoholic fatty liver or gestational diabetes mellitus exhibit a high level of serum NA.

CONCLUSION

Collectively, our current study suggests that NA is a typical metabolite of metabolic syndrome, which strongly influences the ovarian function and embryo survival and also provides that interfering with mitochondrial ROS production is a potential strong strategy for target solving abnormal NA accumulation.

Altered dynamics of calcium fluxes and mitochondrial metabolism in platelet activation-related disease and aging

Understanding the mechanisms controlling platelet function is crucial for exploring potential therapeutic targets related to atherothrombotic pathologies and primary hemostasis disorders. Our research, which focuses on the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis, has significant implications for the development of new therapeutic strategies. Traditionally, Ca2+-dependent cellular signaling has been recognized as a determinant process throughout the platelet activation, controlled primarily by store-operated Ca2+ entry and the PLC-PKC signaling pathway. However, despite the accumulated knowledge of these regulatory mechanisms, the effectiveness of therapy based on various commonly used antiplatelet drugs (such as acetylsalicylic acid and clopidogrel, among others) has faced challenges due to bleeding risks and reduced efficacy associated with the phenomenon of high platelet reactivity. Recent evidence suggests that platelet mitochondria could play a fundamental role in these aspects through Ca2+-dependent mechanisms linked to apoptosis and forming a procoagulant phenotype. In this context, the present review describes the latest advances regarding the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis.

Platelet-Derived TGF-β1 Promotes Deep Vein Thrombosis

BACKGROUND

 Transforming growth factor-β1 (TGF-β1) modulates multiple cellular functions during development and tissue homeostasis. A large amount of TGF-β1 is stored in platelet α-granules and released upon platelet activation. Whether platelet-derived TGF-β1 plays a role in venous thrombosis remains unclear. This study intends to assess the role of platelet-derived TGF-β1 in the development of venous thrombosis in mice.

MATERIAL AND METHODS

 TGF-β1flox/flox and platelet-specific TGF-β1-/- mice were utilized to assess platelet function in vitro, arterial thrombosis induced by FeCl3, tail bleeding time, prothrombin time (PT), activated partial thromboplastin time (APTT), and deep vein thrombosis induced through ligation of the inferior vena cava (IVC). The IVC sample was collected to measure accumulation of neutrophils, monocytes, and the formation of neutrophil extracellular traps (NETs) by immunofluorescence staining.

RESULTS

 TGF-β1 deficiency in platelets did not affect the number of circulating platelets, platelet aggregation, adenosine triphosphate release, and integrin αIIbβ3 activation. Meanwhile, TGF-β1 deficiency did not alter the arterial thrombus formation, hemostasis, and coagulation time (PT and APTT), but significantly impaired venous thrombus formation, inhibited the recruitment and accumulation of neutrophils and monocytes in thrombi, as well as reduced formation of NETs and platelet-neutrophil complex. In addition, adoptive transfer of TGF-β1flox/flox platelets to TGF-β1-/- mice rescued the impaired venous thrombus formation, recruitment of leukocytes and monocytes, as well as the NETs formation.

CONCLUSION

In conclusion, platelet-derived TGF-β1 positively modulates venous thrombus formation in mice, indicating that targeting TGF-β1 might be a novel approach for treating venous thrombosis without increasing the risk of bleeding.

Notch1 regulates hepatic thrombopoietin production

ABSTRACT

Notch signaling regulates cell-fate decisions in several developmental processes and cell functions. However, the role of Notch in hepatic thrombopoietin (TPO) production remains unclear. We noted thrombocytopenia in mice with hepatic Notch1 deficiency and so investigated TPO production and other features of platelets in these mice. We found that the liver ultrastructure and hepatocyte function were comparable between control and Notch1-deficient mice. However, the Notch1-deficient mice had significantly lower plasma TPO and hepatic TPO messenger RNA levels, concomitant with lower numbers of platelets and impaired megakaryocyte differentiation and maturation, which were rescued by addition of exogenous TPO. Additionally, JAK2/STAT3 phosphorylation was significantly inhibited in Notch1-deficient hepatocytes, consistent with the RNA-sequencing analysis. JAK2/STAT3 phosphorylation and TPO production was also impaired in cultured Notch1-deficient hepatocytes after treatment with desialylated platelets. Consistently, hepatocyte-specific Notch1 deletion inhibited JAK2/STAT3 phosphorylation and hepatic TPO production induced by administration of desialylated platelets in vivo. Interestingly, Notch1 deficiency downregulated the expression of HES5 but not HES1. Moreover, desialylated platelets promoted the binding of HES5 to JAK2/STAT3, leading to JAK2/STAT3 phosphorylation and pathway activation in hepatocytes. Hepatocyte Ashwell-Morell receptor (AMR), a heterodimer of asialoglycoprotein receptor 1 [ASGR1] and ASGR2, physically associates with Notch1, and inhibition of AMR impaired Notch1 signaling activation and hepatic TPO production. Furthermore, blockage of Delta-like 4 on desialylated platelets inhibited hepatocyte Notch1 activation and HES5 expression, JAK2/STAT3 phosphorylation, and subsequent TPO production. In conclusion, our study identifies a novel regulatory role of Notch1 in hepatic TPO production, indicating that it might be a target for modulating TPO level.

Photoactivated full-API nanodrug (FAND): harnessing transition metal complexes and MTH1 inhibitor for enhanced DNA damage in cancer cells

The effectiveness of photodynamic therapy (PDT) has been greatly restricted by the hypoxic tumor microenvironment and the susceptible resistance of monotherapy. Although nanodrugs based on transition metal complexes capable of integrating PDT with photoactivated chemotherapy (PACT) have garnered tremendous attention as promising candidates for overcoming the above limitations, the therapeutic efficacy of these nanodrugs is still hampered by inadequate loading of active pharmaceutical ingredients (APIs) and the inherent ability of cancer cells to repair damaged DNA. Herein, we developed a photoactivated full-API nanodrug, Ru-T FAND, by one-step self-assembly of RuDPB and TH287. By virtue of its 100 wt% API content and favorable stability in water, the Ru-T FAND exhibited improved cellular uptake behavior and intracellular 1O2 generation. Attractively, the Ru-T FAND with triple anti-cancer modalities can photogenerate 1O2, photo-release DPB ligand and inhibit the repair of DNA damage, ultimately enhancing its phototherapeutic effect on cancer cells. Importantly, the uncaged DPB ligand from RuDPB emits red fluorescence, enabling real-time monitoring of the drug's absorption, distribution and efficacy. Collectively, the presented photoactivated Ru-T FANDs with multiple anti-cancer mechanisms will expand new horizons for the development of safe, efficient and synergistic tumor phototherapy strategies.

Linking triphenylphosphonium cation to a bicyclic hydroquinone improves their antiplatelet effect via the regulation of mitochondrial function

Platelets are the critical target for preventing and treating pathological thrombus formation. However, despite current antiplatelet therapy, cardiovascular mortality remains high, and cardiovascular events continue in prescribed patients. In this study, first results were obtained with ortho-carbonyl hydroquinones as antiplatelet agents; we found that linking triphenylphosphonium cation to a bicyclic ortho-carbonyl hydroquinone moiety by a short alkyl chain significantly improved their antiplatelet effect by affecting the mitochondrial functioning. The mechanism of action involves uncoupling OXPHOS, which leads to an increase in mitochondrial ROS production and a decrease in the mitochondrial membrane potential and OCR. This alteration disrupts the energy production by mitochondrial function necessary for the platelet activation process. These effects are responsive to the complete structure of the compounds and not to isolated parts of the compounds tested. The results obtained in this research can be used as the basis for developing new antiplatelet agents that target mitochondria.

Redox regulation of platelet function and thrombosis

Platelets are well-known players in several cardiovascular diseases such as atherosclerosis and venous thrombosis. There is increasing evidence demonstrating that reactive oxygen species (ROS) are generated within activated platelets. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a major source of ROS generation in platelets. Ligand binding to platelet receptor glycoprotein (GP) VI stimulates intracellular ROS generation consisting of a spleen tyrosine kinase-independent production involving NOX activation and a following spleen tyrosine kinase-dependent generation. In addition to GPVI, stimulation of platelet thrombin receptors (protease-activated receptors [PARs]) can also trigger NOX-derived ROS production. Our recent study found that mitochondria-derived ROS production can be induced by engagement of thrombin receptors but not by GPVI, indicating that mitochondria are another source of PAR-dependent ROS generation apart from NOX. However, mitochondria are not involved in GPVI-dependent ROS generation. Once generated, the intracellular ROS are also involved in modulating platelet function and thrombus formation; therefore, the site-specific targeting of ROS production or clearance of excess ROS within platelets is a potential intervention and treatment option for thrombotic events. In this review, we will summarize the signaling pathways involving regulation of platelet ROS production and their role in platelet function and thrombosis, with a focus on GPVI- and PAR-dependent platelet responses.

Lactate facilitated mitochondrial fission-derived ROS to promote pulmonary fibrosis via ERK/DRP-1 signaling

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung diseases, which mainly existed in middle-aged and elderly people. The accumulation of reactive oxygen species (ROS) is a common characteristic of IPF. Previous research also shown that lactate levels can be abnormally elevated in IPF patients. Emerging evidence suggested a relationship between lactate and ROS in IPF which needs further elucidation. In this article, we utilized a mouse model of BLM-induced pulmonary fibrosis to detect alterations in ROS levels and other indicators associated with fibrosis. Lactate could induce mitochondrial fragmentation by modulating expression and activity of DRP1 and ERK. Moreover, Increased ROS promoted P65 translocation into nucleus, leading to expression of lung fibrotic markers. Finally, Ulixertinib, Mdivi-1 and Mito-TEMPO, which were inhibitor activity of ERK, DRP1 and mtROS, respectively, could effectively prevented mitochondrial damage and production of ROS and eventually alleviate pulmonary fibrosis. Taken together, these findings suggested that lactate could promote lung fibrosis by increasing mitochondrial fission-derived ROS via ERK/DRP1 signaling, which may provide novel therapeutic solutions for IPF.

When DNA-damage responses meet innate and adaptive immunity

When cells proliferate, stress on DNA replication or exposure to endogenous or external insults frequently results in DNA damage. DNA-Damage Response (DDR) networks are complex signaling pathways used by multicellular organisms to prevent DNA damage. Depending on the type of broken DNA, the various pathways, Base-Excision Repair (BER), Nucleotide Excision Repair (NER), Mismatch Repair (MMR), Homologous Recombination (HR), Non-Homologous End-Joining (NHEJ), Interstrand Crosslink (ICL) repair, and other direct repair pathways, can be activated separately or in combination to repair DNA damage. To preserve homeostasis, innate and adaptive immune responses are effective defenses against endogenous mutation or invasion by external pathogens. It is interesting to note that new research keeps showing how closely DDR components and the immune system are related. DDR and immunological response are linked by immune effectors such as the cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway. These effectors act as sensors of DNA damage-caused immune response. Furthermore, DDR components themselves function in immune responses to trigger the generation of inflammatory cytokines in a cascade or even trigger programmed cell death. Defective DDR components are known to disrupt genomic stability and compromise immunological responses, aggravating immune imbalance and leading to serious diseases such as cancer and autoimmune disorders. This study examines the most recent developments in the interaction between DDR elements and immunological responses. The DDR network's immune modulators' dual roles may offer new perspectives on treating infectious disorders linked to DNA damage, including cancer, and on the development of target immunotherapy.

Cepharanthine synergizes with photodynamic therapy for boosting ROS-driven DNA damage and suppressing MTH1 as a potential anti-cancer strategy

OBJECTIVE

Photodynamic therapy (PDT) primarily treats skin diseases or cancer by generating reactive oxygen species (ROS) to damage cellular DNA, yet drug resistance limits its application. To tackle this problem, the present study was carried out to improve the efficacy of chlorin e6 (Ce6)-PDT using Cepharanthine (CEP) as well as to reveal the potential molecular mechanism.

MATERIALS AND METHODS

Lewis lung cancer cell line (LLC) was utilized as the cancer cell model. chlorin e6 (Ce6) acted as the photosensitizer to induce PDT. The in vitro anti-cancer efficacy was measured by CCK-8, Annexin-V/PI staining, and migration assay. The Ce6 uptake was observed using flow cytometry and confocal microscopy. The ROS generation was detected by the DCFH-DA probe. The analysis of MutT Homolog 1 (MTH1) expression, correlation, and prognosis in databases was conducted by bioinformatic. The MTH1 expression was detected through western blots (WB). DNA damage was assayed by WB, immunofluorescent staining, and comet assay.

RESULTS

Ce6-PDT showed robust resistance in lung cancer cells under certain conditions, as evidenced by the unchanged cell viability and apoptosis. The subsequent findings confirmed that the uptake of Ce6 and MTH1 expression was enhanced, but ROS generation with laser irradiation was not increased in LLC, which indicated that the ROS scavenge may be the critical reason for resistance. Surprisingly, bioinformatic and in vitro experiments identified that MTH1, which could prevent the DNA from damage of ROS, was highly expressed in lung cancer and thereby led to the poor prognosis and could be further up-regulated by Ce6 PDT. CEP exhibited a dose-dependent suppressive effect on the lung cancer cells. Further investigations presented that CEP treatment boosted ROS production, thereby resulting in DNA double-strand breakage (DDSB) with activation of MTH1, indicating that CEP facilitated Ce6-PDT-mediated DNA damage. Finally, the combination of CEP and Ce6-PDT exhibited prominent ROS accumulation, MTH1 inhibition, and anti-lung cancer efficacy, which had synergistic pro-DNA damage properties.

CONCLUSION

Collectively, highly expressed MTH1 and the failure of ROS generation lead to PDT resistance in lung cancer cells. CEP facilitates ROS generation of PDT, thereby promoting vigorous DNA damage, inactivating MTH1, alleviating PDT resistance, and ameliorating the anti-cancer efficacy of Ce6-PDT, provides a novel approach for augmented PDT.

Characterization of active peptides derived from three leeches and comparison of their anti-thrombotic mechanisms using the tail vein thrombosis model in mice and metabonomics

Background and aims: The increasing incidence of cardiovascular diseases has created an urgent need for safe and effective anti-thrombotic agents. Leech, as a traditional Chinese medicine, has the effect of promoting blood circulation and removing blood stasis, but its real material basis and mechanism of action for the treatment of diseases such as blood stasis and thrombosis have not been reported. Methods: In this study, Whitmania Pigra Whitman (WPW), Hirudo nipponica Whitman (HNW) and Whitmania acranutata Whitman (WAW) were hydrolyzed by biomimetic enzymatic hydrolysis to obtain the active peptides of WPW (APP), the active peptides of HNW (APH) and the active peptides of WAW (APA), respectively. Then their structures were characterized by sykam amino acid analyzer, fourier transform infrared spectrometer (FT-IR), circular dichroism (CD) spectrometer and LC-MS. Next, the anti-thrombotic activities of APP, APH and APA were determined by carrageenan-induced tail vein thrombosis model in mice, and the anti-thrombotic mechanisms of high-dose APP group (HAPP), high-dose APH group (HAPH) and high-dose APA group (HAPA) were explored based on UHPLC-Q-Exactive Orbitrap mass spectrometry. Results: The results showed that the amino acid composition of APP, APH and APA was consistent, and the proportion of each amino acid was few different. The results of FT-IR and CD showed that there were no significant differences in the proportion of secondary structures (such as β-sheet and random coil) and infrared absorption peaks between APP, APH and APA. Mass spectrometry data showed that there were 43 common peptides in APP, APH and APA, indicating that the three have common material basis. APP, APH and APA could significantly inhibit platelet aggregation, reduce black-tail length, whole blood viscosity (WBV), plasma viscosity (PV), and Fibrinogen (FIB), and prolong coagulation time, including activated partial thrombin time (APTT), prothrombin time (PT) and thrombin time (TT). In addition, 24 metabolites were identified as potential biomarkers associated with thrombosis development. Among these, 19, 23, and 20 metabolites were significantly normalized after administration of HAPP, HAPH, and HAPA in the mice, respectively. Furthermore, the intervention mechanism of HAPP, HAPH and HAPA on tail vein thrombosis mainly involved in linoleic acid metabolism, primary bile acid biosynthesis and ether lipid metabolism. Conclusion: Our findings suggest that APP, APH and APA can exert their anti-blood stasis and anti-thrombotic activities by interfering with disordered metabolic pathways in vivo, and there is no significant difference in their efficacies.

Celastrol inhibits platelet function and thrombus formation

INTRODUCTION

Celastrol is an active pentacyclic triterpenoid extracted from Tripterygium wilfordii and has anti-inflammatory and anti-tumor properties. Whether Celastrol modulates platelet function remains unknown. Our study investigated its role in platelet function and thrombosis.

METHODS

Human platelets were isolated and incubated with Celastrol (0, 1, 3 and 5 μM) at 37 °C for 1 h to measure platelet aggregation, granules release, spreading, thrombin-induced clot retraction and intracellular calcium mobilization. Additionally, Celastrol (2 mg/kg) was intraperitoneally administrated into mice to evaluate hemostasis and thrombosis in vivo.

RESULTS

Celastrol treatment significantly decreased platelet aggregation and secretion of dense or alpha granules induced by collagen-related peptide (CRP) or thrombin in a dose-dependent manner. Additionally, Celastrol-treated platelets showed a dramatically reduced spreading activity and decreased clot retraction. Moreover, Celastrol administration prolonged tail bleeding time and inhibited formation of arterial/venous thrombosis. Furthermore, Celastrol significantly reduced calcium mobilization.

CONCLUSION

Celastrol inhibits platelet function and venous/arterial thrombosis, implying that it might be utilized for treating thrombotic diseases.

Reactive Oxygen Species-Responsive Sequentially Targeted AIE Fluorescent Probe for Precisely Identifying the Atherosclerotic Plaques

The formation of atherosclerosis is the root cause of various cardiovascular diseases (CVDs). Therefore, effective CVD interventions call for precise identification of the plaques to aid in clinical treatment of such diseases. Herein, a reactive oxygen species (ROS)-responsive sequentially targeted fluorescent probe is developed for atherosclerotic plaque recognition. An aggregation-induced emission active fluorophore is linked to maleimide (polyethylene glycol) hydroxyl with a ROS-responsive cleavable bond, which is further functionalized with CLIKKPF peptide (TPAMCF) for specifically binding to phosphatidylserine of the foam cells. After being assembled in aqueous medium, TPAMCF nanoparticles can efficiently accumulate in the plaques through the high affinity of CLIKKPF to the externalized phosphatidylserine of the foam cells. Activated by the locally accumulated ROS in foam cells, the nanoparticles are interrupted, and then TPA can be released and subsequently identify the lipid droplets inside the foam cells to achieve fluorescence imaging of the plaques. Such nanoprobes have the favorable ROS response performance and exhibit a special target binding to the foam cells in vitro. In addition, nanoprobe-based fluorescence imaging permitted the high-contrast and precise detection of atherosclerosis specimens ex vivo. Therefore, as a promising fluorescent probe, TPAMCF is capable of being a potential candidate for the detection of atherosclerotic plaque.