ROS-Dependent Activation of Autophagy through the PI3K/Akt/mTOR Pathway Is Induced by Hydroxysafflor Yellow A-Sonodynamic Therapy in THP-1 Macrophages

Modulation of atherosclerosis-related signaling pathways by Chinese herbal extracts: Recent evidence and perspectives

Atherosclerotic cardiovascular disease remains a preeminent cause of morbidity and mortality globally. The onset of atherosclerosis underpins the emergence of ischemic cardiovascular diseases, including coronary heart disease (CHD). Its pathogenesis entails multiple factors such as inflammation, oxidative stress, apoptosis, vascular endothelial damage, foam cell formation, and platelet activation. Furthermore, it triggers the activation of diverse signaling pathways including Phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), NF-E2-related factor 2/antioxidant response element (Nrf2/ARE), the Notch signaling pathway, peroxisome proliferator-activated receptor (PPAR), nucleotide oligo-structural domain-like receptor thermoprotein structural domain-associated protein 3 (NLRP3), silencing information regulator 2-associated enzyme 1 (Sirt1), nuclear transcription factor-κB (NF-κB), Circular RNA (Circ RNA), MicroRNA (mi RNA), Transforming growth factor-β (TGF-β), and Janus kinase-signal transducer and activator of transcription (JAK/STAT). Over recent decades, therapeutic approaches for atherosclerosis have been dominated by the utilization of high-intensity statins to reduce lipid levels, despite significant adverse effects. Consequently, there is a growing interest in the development of safer and more efficacious drugs and therapeutic modalities. Traditional Chinese medicine (TCM) offers a vital strategy for the prevention and treatment of cardiovascular diseases. Numerous studies have detailed the mechanisms through which TCM active ingredients modulate signaling molecules and influence the atherosclerotic process. This article reviews the signaling pathways implicated in the pathogenesis of atherosclerosis and the advancements in research on TCM extracts for prevention and treatment, drawing on original articles from various databases including Google Scholar, Medline, CNKI, Scopus, and Pubmed. The objective is to furnish a reference for the clinical management of cardiovascular diseases.

Sonodynamic therapy for the treatment of atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease of large and medium-sized arteries that leads to ischemic heart disease, stroke, and peripheral vascular disease. Despite the current treatments, mortality and disability still remain high. Sonodynamic therapy (SDT), a non-invasive and localized methodology, has been developed as a promising new treatment for inhibiting atherosclerotic progression and stabilizing plaques. Promising progress has been made through cell and animal assays, as well as clinical trials. For example, the effect of SDT on apoptosis and autophagy of cells in AS, especially macrophages, and the concept of non-lethal SDT has also been proposed. In this review, we summarize the ultrasonic parameters and known sonosensitizers utilized in SDT for AS; we elaborate on SDT's therapeutic effects and mechanisms in terms of macrophages, T lymphocytes, neovascularization, smooth muscle cells, lipid, extracellular matrix and efferocytosis within plaques; additionally, we discuss the safety of SDT. A comprehensive summary of the confirmed effects of SDT on AS is conducted to establish a framework for future researchers.

An update on alternative therapy for Escherichia coli causing urinary tract infections; a narrative review

BACKGROUND

Urinary tract infections (UTIs) are the most common type of nosocomial infection and severe health issues because of the difficulties and frequent recurrence. Today, alternative methods such as sonodynamic therapy (SDT), photodynamic therapy (PDT) and herbal materials use for treating infections like UTI in many countries.

METHOD

We conducted searches of the biomedical databases (Google Scholar, Scopus, PubMed, and Web of sciences) to identify related studies from 2008 to 2023.

RESULT

SDT aims to use ultrasound to activate a sonosensitizer, which causes a biological effect by raising reactive oxygen species (ROS). When bacteria are exposed to ROS, several important effects occur: oxidative damage, DNA damage, protein dysfunction etc. SDT with herbal medicine significantly reduced the number of colony-forming units and bactericidal activity for Klebsiella pneumonia and E. coli. PDT is a promising treatment for cancer and microbial infections, combining a photosensitiser, light and tissue molecular oxygen. It involves a photosensitizer, light source, and oxygen, with variations affecting microbial binding and bactericidal activity. Factors affecting antibacterial properties include plant type, growing conditions, harvesting, and processing. This review highlights the recent advancements in sonodynamic, photodynamic, herbal, and bio-material-based approaches in the treatment of E. coli infections.

CONCLUSIONS

These alternative therapies offer exciting prospects for addressing UTIs, especially in cases where traditional antibiotic treatments may be less effective. Further research and clinical studies are warranted to fully explore the potential of these innovative treatment modalities in combating UTIs and improving patient outcomes.

The association and application of sonodynamic therapy and autophagy in diseases

Sonodynamic therapy (SDT) is a new non-invasive treatment method proposed based on photodynamic therapy (PDT). It has advantages such as high precision, strong tissue penetration, minimal side effects, and good patient compliance. With the maturation of nanomedicine, the application of nanosonosensitizers has further propelled the development of SDT. In recent years, people have developed many new types of sonosensitizers and explored the mechanisms of SDT. Among them, the studies about the relationship between autophagy and SDT have attracted increasing attention. After the SDT, cells usually undergo autophagy as a self-protective mechanism to resist external stimuli and reduce cell damage, which is beneficial for the treatment of atherosclerosis (AS), diabetes, and myocardial infarction but counterproductive in cancer treatment. However, under certain treatment conditions, excessive upregulation of autophagy can also promote cell death, which is beneficial for cancer treatment. This article reviews the latest research progress on the relationship between SDT and autophagy in cancers, AS, diabetes, and myocardial infarction. We also discuss and propose the challenges and prospects in enhancing SDT efficacy by regulating autophagy, with the hope of promoting the development of this promising therapeutic approach.

The role of cell death in SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), showing high infectiousness, resulted in an ongoing pandemic termed coronavirus disease 2019 (COVID-19). COVID-19 cases often experience acute respiratory distress syndrome, which has caused millions of deaths. Apart from triggering inflammatory and immune responses, many viral infections can cause programmed cell death in infected cells. Cell death mechanisms have a vital role in maintaining a suitable environment to achieve normal cell functionality. Nonetheless, these processes are dysregulated, potentially contributing to disease pathogenesis. Over the past decades, multiple cell death pathways are becoming better understood. Growing evidence suggests that the induction of cell death by the coronavirus may significantly contributes to viral infection and pathogenicity. However, the interaction of SARS-CoV-2 with cell death, together with its associated mechanisms, is yet to be elucidated. In this review, we summarize the existing evidence concerning the molecular modulation of cell death in SARS-CoV-2 infection as well as viral-host interactions, which may shed new light on antiviral therapy against SARS-CoV-2.

Sonocatalytic Optimization of Titanium-Based Therapeutic Nanomedicine

Recent considerable technological advances in ultrasound-based treatment modality provides a magnificent prospect for scientific communities to conquer the related diseases, which is featured with remarkable tissue penetration, non-invasive and non-thermal characteristics. As one of the critical elements that influences treatment outcomes, titanium (Ti)-based sonosensitizers with distinct physicochemical properties and exceptional sonodynamic efficiency have been applied extensively in the field of nanomedical applications. To date, a myriad of methodologies has been designed to manipulate the sonodynamic performance of titanium-involved nanomedicine and further enhance the productivity of reactive oxygen species for disease treatments. In this comprehensive review, the sonocatalytic optimization of diversified Ti-based nanoplatforms, including defect engineering, plasmon resonance modulation, heterojunction, modulating tumor microenvironment, as well as the development of synergistic therapeutic modalities is mainly focused. The state-of-the-art Ti-based nanoplatforms ranging from preparation process to the extensive medical applications are summarized and highlighted, with the goal of elaborating on future research prospects and providing a perspective on the bench-to-beside translation of these sonocatalytic optimization tactics. Furthermore, to spur further technological advancements in nanomedicine, the difficulties currently faced and the direction of sonocatalytic optimization of Ti-based therapeutic nanomedicine are proposed and outlooked.

Recent Advances for Dynamic-Based Therapy of Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease, which may lead to high morbidity and mortality. Currently, the clinical treatment strategy for AS is administering drugs and performing surgery. However, advanced therapy strategies are urgently required because of the deficient therapeutic effects of current managements. Increased number of energy conversion-based organic or inorganic materials has been used in cancer and other major disease treatments, bringing hope to patients with the development of nanomedicine and materials. These treatment strategies employ specific nanomaterials with specific own physiochemical properties (external stimuli: light or ultrasound) to promote foam cell apoptosis and cholesterol efflux. Based on the pathological characteristics of vulnerable plaques, energy conversion-based nano-therapy has attracted increasing attention in the field of anti-atherosclerosis. Therefore, this review focuses on recent advances in energy conversion-based treatments. In addition to summarizing the therapeutic effects of various techniques, the regulated pathological processes are highlighted. Finally, the challenges and prospects for further development of dynamic treatment for AS are discussed.

Melatonin inhibits atherosclerosis progression via galectin-3 downregulation to enhance autophagy and inhibit inflammation

Autophagy deficiency in macrophages exacerbates inflammation in atherosclerosis (AS), and recently, galectin-3 (Gal-3) has been implicated as a critical promoter of inflammation in AS. Further, melatonin (Mel) exerts an autophagy-promoting effect in many chronic inflammatory diseases. In this study, we aimed to investigate whether Mel inhibits AS progression by downregulating Gal-3 to enhance autophagy and inhibit inflammation. Thus, we performed in vivo and in vitro experiments using high-fat diet (HFD)-fed ApoE^-/-  mice and THP-1 macrophages, respectively. Smart-seq of AS plaque macrophages revealed that the differentially expressed genes (DEGs) downregulated by Mel were enriched in immune-related processes, and changes in inflammation status were confirmed based on lower levels of proinflammatory factors in Mel-treated HFD-fed ApoE^-/-  mice and THP-1 macrophages. Further, via transcriptome-based multiscale network pharmacology platform (TMNP), the upstream target genes of the smart-seq DEGs were identified, and Gal-3 showed a high score. Gal-3 was downregulated both in vivo and in vitro by Mel treatment. Besides, the enrichment of the target genes predicted via the TMNP method indicated that autophagy considerably affected the DEGs. Mel treatment as well as Gal-3 knockdown downregulated most inflammatory response-related proteins could attribute to enhancing autophagy. Mechanistically, Mel treatment inhibited Gal-3 leading to lowering the activity of the nuclear transcription factor-kappa B (NF-κB) pathway, and promoting the nuclear localization of transcription factor EB (TFEB). However, increased secretion of Gal-3 activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway and impaired autophagy via binding to CD98. Thus, Mel promoted autophagy and restrained inflammation by downregulating Gal-3, implying that it holds promise as a treatment for AS.

ETNPPL impairs autophagy through regulation of the ARG2-ROS signaling axis, contributing to palmitic acid-induced hepatic insulin resistance

Excessive free fatty acids (FFAs) accumulation is a leading risk factor for the pathogenesis of insulin resistance (IR) in metabolic tissues, including the liver. Ethanolamine-phosphate phospho-lyase (ETNPPL), a newly identified metabolic enzyme, catalyzes phosphoethanolamine (PEA) to ammonia, inorganic phosphate, and acetaldehyde and is highly expressed in hepatic tissue. Whether it plays a role in regulating FFA-induced IR in hepatocytes has yet to be understood. In this study, we established an in vitro palmitic acid (PA)-induced IR model in human HepG2 cells and mouse AML12 cells with chronic treatment of PA. Next, we overexpressed ETNPPL by using lentivirus-mediated ectopic to investigate the effects of ETNPPL per se on IR without PA stimulation. We show that ETNPPL expression is significantly elevated in PA-induced IR and that silencing ETNPPL ameliorates this IR in hepatocytes. Inversely, overexpressing ETNPPL under normal conditions without PA promotes IR, reactive oxygen species generation, and ARG2 activation in both HepG2 and AML12 cells. Moreover, ETNPPL depletion markedly down-regulates ARG2 expression in hepatocytes. Besides, silencing ARG2 prevents ETNPPL-induced ROS accumulation and inhibition of autophagic flux and IR in hepatocytes. Finally, we found that phytopharmaceutical disruption of ETNPPL by quercetin ameliorates PA-induced IR in hepatocytes. Our study discloses that ETNPPL inhibiting autophagic flux mediates insulin resistance triggered by PA in hepatocytes via ARG2/ROS signaling cascade. Our findings provide novel insights into elucidating the pathogenesis of obesity-associated hepatic IR, suggesting that targeting ETNPPL might represent a potential approach for T2DM therapy.

Natural compounds from botanical drugs targeting mTOR signaling pathway as promising therapeutics for atherosclerosis: A review

Atherosclerosis (AS) is a chronic inflammatory disease that is a major cause of cardiovascular diseases (CVDs), including coronary artery disease, hypertension, myocardial infarction, and heart failure. Hence, the mechanisms of AS are still being explored. A growing compendium of evidence supports that the activity of the mechanistic/mammalian target of rapamycin (mTOR) is highly correlated with the risk of AS. The mTOR signaling pathway contributes to AS progression by regulating autophagy, cell senescence, immune response, and lipid metabolism. Various botanical drugs and their functional compounds have been found to exert anti- AS effects by modulating the activity of the mTOR signaling pathway. In this review, we summarize the pathogenesis of AS based on the mTOR signaling pathway from the aspects of immune response, autophagy, cell senescence, and lipid metabolism, and comb the recent advances in natural compounds from botanical drugs to inhibit the mTOR signaling pathway and delay AS development. This review will provide a new perspective on the mechanisms and precision treatments of AS.

Tuning macrophages for atherosclerosis treatment

Atherosclerosis is a chronic inflammatory vascular disease and a leading cause of death worldwide. Macrophages play an important role in inflammatory responses, cell-cell communications, plaque growth and plaque rupture in atherosclerotic lesions. Here, we review the sources, functions and complex phenotypes of macrophages in the progression of atherosclerosis, and discuss the recent approaches in modulating macrophage phenotype and autophagy for atherosclerosis treatment. We then focus on the drug delivery strategies that target macrophages or use macrophage membrane-coated particles to deliver therapeutics to the lesion sites. These biomaterial-based approaches that target, modulate or engineer macrophages have broad applications for disease therapies and tissue regeneration.

A bibliometric analysis of autophagy in atherosclerosis from 2012 to 2021

Background: Regulation of autophagy affects the progression of atherosclerosis. In recent years, research on autophagy in atherosclerosis has been widely concerned. However, there is no bibliometric analysis in this field.

Objective: The purpose of this study was to explore the general situation, hot spots, and trends of the research in this field through bibliometric analysis.

Methods: Articles related to autophagy in atherosclerosis from 2012 to 2021 were retrieved from the Web of Science Core Collection. VOSviewer and CiteSpace were used for data analysis and visualization of countries, institutions, authors, keywords, journals, and citations.

Results: A total of 988 articles were obtained in the last 10 years. The number of publications and citations increased rapidly from 2012 to 2021, especially after 2019. The most productive countries, institutions, journals, and authors were the People’s Republic of China, Shandong University, Arteriosclerosis Thrombosis and Vascular Biology, and Wim Martinet, respectively. The primary keywords were “oxidative stress,” “apoptosis,” “activated protein kinase,” and “inflammation.” The burst detection analysis of keywords found that “SIRT1” and “long non-coding RNA” might be regarded as the focus of future research.

Conclusion: This is the first bibliometric analysis of autophagy in atherosclerosis, which reports the hot spots and emerging trends. The interaction between oxidative stress and autophagy, programmed cell death, and activated protein kinases are considered to be the current research priorities. Molecular mechanisms and therapeutic target for the intervention of atherosclerosis by regulating autophagy will become an emerging research direction.

Oncolytic Impediment/Promotion Balance Disruption by Sonosensitizer-Free Nanoplatforms Unfreezes Autophagy-Induced Resistance to Sonocatalytic Therapy

Autophagy as a double-edged sword features an oncolytic impediment/promotion balance, which manipulates tumor progression. From this perspective, a sonosensitizer-free targeting oncolytic nanoplatform (SFTON) consisting of chloroquine (CQ) and porphyrin-structured metal centers (PMCS) was engineered to break this balance for enhancing antitumor activity. Porphyrin structure retention in a ZIF-8-derived hydrophobic carbon skeleton retained high stability and high sonocatalytic activity, and the hydrophobic carbon skeleton capable of adsorbing air provided cavitation nuclei for further elevating sonocatalytic activity. More significantly, the encapsulated CQ as the autophagy inhibitor reprogrammed autophagy, terminated the autophagy-induced self-protection or self-detoxification, and unfroze the resistances to reactive oxygen species (ROS) therapy associated with ROS accumulation and ROS activity. Systematic experiments reveal the action principles and validate that the induced apoptosis and blockaded autophagosome escalation into the autolysosome were two activated pathways to magnify the antitumor sonocatalytic therapy. Contributed by these actions, the SFTON-unlocked oncolytic impediment/promotion balance disruption strategy acquired considerable antitumor outcomes in vivo and in vitro against liver tumor progression, especially after combining with AS1411-mediated active targeting. This impediment/promotion balance disruption enabled by the SFTON can serve as a general method to elevate ROS-based antitumor activity.

The crosstalk between sonodynamic therapy and autophagy in cancer

As a noninvasive treatment approach for cancer and other diseases, sonodynamic therapy (SDT) has attracted extensive attention due to the deep penetration of ultrasound, good focusing, and selective irradiation sites. However, intrinsic limitations of traditional sonosensitizers hinder the widespread application of SDT. With the development of nanotechnology, nanoparticles as sonosensitizers or as a vehicle to deliver sonosensitizers have been designed and used to target tissues or tumor cells with high specificity and accuracy. Autophagy is a common metabolic alteration in both normal cells and tumor cells. When autophagy happens, a double-membrane autophagosome with sequestrated intracellular components is delivered and fused with lysosomes for degradation. Recycling these cell materials can promote survival under a variety of stress conditions. Numerous studies have revealed that both apoptosis and autophagy occur after SDT. This review summarizes recent progress in autophagy activation by SDT through multiple mechanisms in tumor therapies, drug resistance, and lipid catabolism. A promising tumor therapy, which combines SDT with autophagy inhibition using a nanoparticle delivering system, is presented and investigated.

LIFU-responsive nanomedicine enables acoustic droplet vaporization-induced apoptosis of macrophages for stabilizing vulnerable atherosclerotic plaques

Due to the high risk of tearing and rupture, vulnerable atherosclerotic plaques would induce serious cardiovascular and cerebrovascular diseases. Despite the available clinical methods can evaluate the vulnerability of plaques and specifically treat vulnerable plaques before a cardiovascular event, but the efficiency is still low and undesirable. Herein, we rationally design and engineer the low-intensity focused ultrasound (LIFU)-responsive FPD@CD nanomedicine for the highly efficient treatment of vulnerable plaques by facilely loading phase transition agent perfluorohexane (PFH) into biocompatible PLGA-PEG-PLGA nanoparticles (PPP NPs) and then attaching dextran sulphate (DS) onto the surface of PPP NPs for targeting delivery. DS, as a typical macrophages-targeted molecule, can achieve the precise vaporization of NPs and subsequently controllable apoptosis of RAW 264.7 macrophages as induced by acoustic droplet vaporization (ADV) effect. In addition, the introduction of DiR and Fe₃O₄ endows nanomedicine with near-infrared fluorescence (NIRF) and magnetic resonance (MR) imaging capabilities. The engineered FPD@CD nanomedicine that uses macrophages as therapeutic targets achieve the conspicuous therapeutic effect of shrinking vulnerable plaques based on in vivo and in vitro evaluation outcomes. A reduction of 49.4% of vascular stenosis degree in gross pathology specimens were achieved throughout the treatment period. This specific, efficient and biosafe treatment modality potentiates the biomedical application in patients with cardiovascular and cerebrovascular diseases based on the relief of the plaque rupture concerns.

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A new nanomedicine-enabled treatment strategy has been developed for treating vulnerable plaques by employing ADV.

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The optimal treatment conditions for ADV have been explored, including LIFU irradiation power intensity and plaque stability.

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The underlying mechanism of nanomedicine-enabled ADV in the treatment of vulnerable plaques has been studied systematically.

Inhibition of Connexin 43 reverses ox-LDL-mediated inhibition of autophagy in VSMC by inhibiting the PI3K/Akt/mTOR signaling pathway

Background

Oxidized low-density lipoproteins (ox-LDL) may induce foam cell formation from the vascular smooth muscle cell (VSMC) by inhibiting VSMC autophagy. This process accelerates the formation of atherosclerosis (AS). Connexin 43 (Cx43), which is the most widely distributed connexin in VSMC is associated with autophagy. However, the mechanism of action and the involvement of Cx43 in ox-LDL-inhibited VSMC autophagy remain unclear.

Methods

The primary VSMC were obtained and identified, before primary VSMC were pretreated with an inhibitor (Cx43-specific inhibitor Gap26 and PI3K inhibitor LY294002) and stimulated with ox-LDL.

Results

Ox-LDL not only inhibited autophagy in VSMC via downregulation of autophagy-related proteins (such as Beclin 1, LC3B, p62), but also increased Cx43 protein levels. Then we added Gap26 to VSMC in the ox-LDL+Gap26 group, in which autophagy-related proteins were increased and the accumulation of lipid droplets was reduced. These result suggested that an enhanced level of autophagy and an alleviation of lipid accumulation might be caused by inhibiting Cx43 in VSMC. The phosphorylation levels of PI3K, AKT, mTOR were increased by ox-LDL, thus down-regulating autophagy-related proteins. However, this situation was partially reversed by the Gap26. Moreover, Cx43 expression were decreased by LY294002 in ox-LDL-induced VSMCs.

Conclusion

Inhibiting Cx43 may activate VSMC autophagy to inhibit foam cell formation by inhibiting the PI3K/AKT/mTOR signaling pathway.

Berberine inhibited carotid atherosclerosis through PI3K/AKTmTOR signaling pathway

Atherosclerosis, a multifactorial vascular disease resulting from lipid metabolism disorders, features chronic inflammatory damage resulting from endothelial dysfunction, which usually affects multiple arteries. The carotid artery is a common site for clinical atherosclerosis evaluation. The aortic root is the standard site for quantifying atherosclerosis in mice. Due to the adverse reactions of first-line drugs, it is necessary to discover new drugs to prevent and treat atherosclerosis. Berberine (BBR) is one of the most promising natural products derived from herbal medicine Coptidis Rhizoma (Huanglian) that features significant anti-atherosclerosis properties. However, overall BBR mechanism against carotid atherosclerosis has not been clearly discovered. Our work aimed to investigate potential BBR mechanism in improving carotid atherosclerosis in ApoE knockout mice. Here, we proved that in ApoE -/- mice receiving high-fat diet for 12 weeks, BBR can reduce serum lipid levels, improve intimal hyperplasia, and antagonize carotid lipid accumulation, which may be achieved through regulating the PI3K/AKT/mTOR signaling pathway, regulating autophagy, promoting cell proliferation and inhibiting cell apoptosis. In summary, these data indicate that BBR can ameliorate carotid atherosclerosis. Therefore, it could be a promisingly therapeutic alternative for atherosclerosis.

mTOR pathway: A potential therapeutic target for spinal cord injury

Spinal cord injury (SCI) is the most common disabling spinal injury, and the complex pathological process can eventually lead to severe neurological dysfunction. Many studies have reported that the mammalian target of rapamycin (mTOR) signaling pathway plays an important role in synaptogenesis, neuron growth, differentiation, and survival after central nervous system injury. It is also involved in various traumatic and central nervous system diseases, including traumatic brain injury, neonatal hypoxic-ischemic brain injury, Alzheimer's disease, Parkinson's disease, and cerebral apoplexy. mTOR has also been reported to play an important regulatory role in various pathophysiological processes following SCI. Activation of mTOR signals after SCI can regulate physiological and pathological processes, such as proliferation and differentiation of neural stem cells, regeneration of nerve axons, neuroinflammation, and glial scar formation, through various pathways. Inhibition of mTOR activity has been confirmed to promote repair in SCI. At present, many studies have reported that Chinese herbal medicine can inhibit the SCI-activated mTOR pathway to improve the microenvironment and promote nerve repair after SCI. Due to the role of the mTOR pathway in SCI, it may be a potential therapeutic target for SCI. This review is focused on the pathophysiological process of SCI, characteristics of the mTOR pathway, role of the mTOR pathway in SCI, role of inhibition of mTOR on SCI, and role and significance of inhibition of mTOR by related Chinese herbal medicine inhibitors in SCI. In addition, the review discusses the deficiencies and solutions to mTOR and SCI research shortcomings. This study hopes to provide reference for mTOR and SCI research and a theoretical basis for SCI biotherapy.

Assessment of tantalum nanoparticle-induced MC3T3-E1 proliferation and underlying mechanisms

OBJECTIVE

In our previous study, tantalum nanoparticle (Ta-NPs) was demonstrated to promote osteoblast proliferation via autophagy induction, but the specific mechanism remains unclear. In the present study, we will explore the potential mechanism.

METHODS

Ta-NPs was characterized by transmission electron microscopy, scanning electron microscopy, dynamic light scattering, and BET specific surface area test. MC3T3-E1 were treated with 0 or 20 μg/mL Ta-NPs with or without pretreatment with 10 μM LY294002, Triciribine, Rapamycin (PI3K/Akt/mTOR pathway inhibitors) for 1 h respectively. Western blotting was used to detect the expressions of pathway proteins and LC3B. CCK-8 assay was used to assess cell viability. Flow cytometry was used to detect apoptosis and cell cycle.

RESULTS

After pretreatment with LY294002, Triciribine and Rapamycin, the p-Akt/Akt ratio of pathway protein in Triciribine and Rapamycin groups decreased (P < 0.05), while the autophagy protein LC3-II/LC3-I in the Rapamycin group was upregulated obviously (P < 0.001). In all pretreated groups, apoptosis was increased (LY294002 group was the most obvious), G1 phase cell cycle was arrested (Triciribine and Rapamycin groups were more obvious), and MC3T3-E1 cells were proliferated much more (P < 0.01, P < 0.001, P < 0.05).

CONCLUSION

Pretreatment with Triciribine or Rapamycin has a greater effect on pathway protein Akt, cell cycle arrest, autophagy protein, and cell proliferation but with inconsistent magnitude, which may be inferred that the Akt/mTOR pathway, as well as its feedback loop, were more likely involved in these processes.

Organic Sonosensitizers for Sonodynamic Therapy: From Small Molecules and Nanoparticles toward Clinical Development

Sonodynamic therapy (SDT) is a novel noninvasive therapeutic modality that combines low-intensity ultrasound and sonosensitizers. Versus photo-mediated therapy, SDT has the advantages of deeper tissue penetration, high accuracy, and less side effects. Sonosensitizers are critical for therapeutic efficacy during SDT and organic sonosensitizers are important because of their clear structure, easy monitoring, evaluation of drug metabolism, and clinical transformation. Notably, nanotechnology can be used in the field of sonosensitizers and SDT to overcome the inherent obstacles and achieve sustainable innovation. This review introduces organic small molecule sonosensitizers, nano organic sonosensitizers, and their clinical translation by providing ideas and references for the design of sonosensitizers and SDT so as to promote its transformation to clinical applications in the future.

Molecular Imaging-Guided Sonodynamic Therapy

Low-intensity ultrasound-triggered sonodynamic therapy (SDT) is a promising noninvasive therapeutic modality due to its strong tissue penetration ability. In recent years, with the development of nanotechnology, nanoparticle-based sonosensitizer-mediated SDT has been widely investigated. With the increasing demand for precise and personalized treatment, abundant novel sonosensitizers with imaging capabilities have been developed for determining the optimal therapeutic window, thus significantly enhancing treatment efficacy. In this review, we focus on the molecular imaging-guided SDT. The prevalent mechanisms of SDT are discussed, including ultrasonic cavitation, sonoluminescence, reactive oxygen species, and mechanical damage. In addition, we introduce the major molecular imaging techniques and the design principles based on nanoparticles to achieve efficient imaging. Furthermore, the imaging-guided SDT for the treatment of cancer, bacterial infections, and vascular diseases is summarized. The ultimate goal is to design more effective imaging-guided SDT modalities and provide novel ideas for clinical translation of SDT.

Hydroxysafflor yellow A, a natural compound from Carthamus tinctorius L with good effect of alleviating atherosclerosis

BACKGROUND

Atherosclerosis is a chronic vascular inflammatory disease with complex pathogenesis. Its serious consequence is insufficient blood supply to heart and brain, which eventually leads to myocardial ischemia, infarction and stroke. Hydroxysafflor yellow A (HSYA), a single chalcone glycoside compound with a variety of pharmacological effects, which has shown a potential biological activity for prevention and treatment of atherosclerosis.

PURPOSE

The main purpose of this review is to comprehensively elucidate the mechanism of HSYA on atherosclerosis and its risk factors (hyperlipidemia, hypertension and diabetes mellitus).

METHOD

The literatures on HSYA in the treatment of atherosclerosis and its risk factors were searched in PubMed, Google Scholar, China National Knowledge Infrastructure, including in vitro (cell), in vivo (animal) and clinical (human) studies, and summarized reasonably.

RESULTS

HSYA is a promising natural product for treating atherosclerosis. It can suppress foam cell formation, vascular endothelial cell dysfunction, vascular smooth muscle cell proliferation and migration, and platelet activation. The mechanisms are achieved by regulating the reverse cholesterol transport process, fatty acid synthesis, oxidative stress, PI3K/Akt/mTOR, NLRP3 inflammasome, TNFR1/NF-κB, NO-cGMP, Bax/Bcl-2, MAPKs, CDK/CyclinD and TLR4/Rac1/Akt signaling pathways. Besides, HSYA is devoted to lowering blood lipids, regulating ion channels, reducing vascular inflammation, and protecting pancreatic beta cells, which is conducive to reducing the harm of independent risk factors of atherosclerosis.

CONCLUSIONS

HSYA exhibits the preventive and therapeutic effects on atherosclerosis and its risk factors in vivo and in vitro, which is relevant to multiple mechanisms. The clinical trials of HSYA need to be further investigated to provide a solid foundation for its clinical application.

Role of Herbal Teas in Regulating Cellular Homeostasis and Autophagy and Their Implications in Regulating Overall Health

Tea is one of the most popular and widely consumed beverages worldwide, and possesses numerous potential health benefits. Herbal teas are well-known to contain an abundance of polyphenol antioxidants and other ingredients, thereby implicating protection and treatment against various ailments, and maintaining overall health in humans, although their mechanisms of action have not yet been fully identified. Autophagy is a conserved mechanism present in organisms that maintains basal cellular homeostasis and is essential in mediating the pathogenesis of several diseases, including cancer, type II diabetes, obesity, and Alzheimer’s disease. The increasing prevalence of these diseases, which could be attributed to the imbalance in the level of autophagy, presents a considerable challenge in the healthcare industry. Natural medicine stands as an effective, safe, and economical alternative in balancing autophagy and maintaining homeostasis. Tea is a part of the diet for many people, and it could mediate autophagy as well. Here, we aim to provide an updated overview of popular herbal teas’ health-promoting and disease healing properties and in-depth information on their relation to autophagy and its related signaling molecules. The present review sheds more light on the significance of herbal teas in regulating autophagy, thereby improving overall health.

Mg(OH)2 nanoparticles enhance the antibacterial activities of macrophages by activating the reactive oxygen species

Infection often causes disastrous consequences in all fields of clinical medicine, especially orthopedics. Hence, critical efforts are being made to engineer novel nanomaterials for the treatment of orthopedic infections due to the high biocompatibility and antibacterial properties they possess. The purpose of this study was to investigate the antibacterial effects of magnesium hydroxide (Mg(OH)₂ ) nanoparticles (NPs) in vitro and determine their possible mechanisms of action. In this study, Escherichia coli was selected as the pathogenic bacteria and it was found that Mg(OH)₂ NPs significantly inhibited the growth of E. coli by promoting nucleic acid leakage, inhibiting protein synthesis, and suppressing the metabolic activity. The minimum inhibitory concentration for these bacteria was determined to be 4.4 μg/ml. In vitro flow cytometry and immunofluorescence tests indicated that Mg(OH)₂ NPs induced the macrophages to generate reactive oxygen species to kill the bacteria. To understand the mechanisms involved in this process, western blotting was performed and it was found that Mg(OH)₂ NPs activated the phosphatidylinositol-3-kinase/serine-threonine kinase (PI3K/Akt) signaling pathway of macrophages to enhance their phagocytosis with no obvious cytotoxicity. Thus, Mg(OH)₂ NPs are a suitable choice to develop promising agents or coating materials for the treatment of clinically widespread infections in view of their safety, biocompatibility, and powerful antibacterial properties.

Oleic Acid and Eicosapentaenoic Acid Reverse Palmitic Acid-induced Insulin Resistance in Human HepG2 Cells via the Reactive Oxygen Species / JUN Pathway

Oleic acid (OA), a monounsaturated fatty acid (MUFA), has previously been shown to reverse saturated fatty acid palmitic acid (PA)-induced hepatic insulin resistance (IR). However, its underlying molecular mechanism is unclear. In addition, previous studies have shown that eicosapentaenoic acid (EPA), a ω-3 polyunsaturated fatty acid (PUFA), reverses PA-induced muscle IR, but whether EPA plays the same role in hepatic IR and its possible mechanism involved need to be further clarified. Here, we confirmed that EPA reversed PA-induced IR in HepG2 cells and compared the proteomic changes in HepG2 cells after treatment with different free fatty acids (FFAs). A total of 234 proteins were determined to be differentially expressed after PA+OA treatment. Their functions were mainly related to responses to stress and endogenous stimuli, lipid metabolic process, and protein binding. For PA+EPA treatment, the PA-induced expression changes of 1326 proteins could be reversed by EPA, 415 of which were mitochondrial proteins, with most of the functional proteins involved in oxidative phosphorylation (OXPHOS) and tricarboxylic acid (TCA) cycle. Mechanistic studies revealed that the protein encoded by JUN and reactive oxygen species (ROS) play a role in OA- and EPA-reversed PA-induced IR, respectively. EPA and OA alleviated PA-induced abnormal adenosine triphosphate (ATP) production, ROS generation, and calcium (Ca²⁺) content. Importantly, H₂O₂-activated production of ROS increased the protein expression of JUN, further resulting in IR in HepG2 cells. Taken together, we demonstrate that ROS/JUN is a common response pathway employed by HepG2 cells toward FFA-regulated IR.

Rosuvastatin exerts anti-atherosclerotic effects by improving macrophage-related foam cell formation and polarization conversion via mediating autophagic activities

BACKGROUND

Atherosclerosis is a chronic vascular disease posing a great threat to public health. We investigated whether rosuvastatin (RVS) enhanced autophagic activities to inhibit lipid accumulation and polarization conversion of macrophages and then attenuate atherosclerotic lesions.

METHODS

All male Apolipoprotein E-deficient (ApoE-/-) mice were fed high-fat diet supplemented with RVS (10 mg/kg/day) or the same volume of normal saline gavage for 20 weeks. The burden of plaques in mice were determined by histopathological staining. Biochemical kits were used to examine the levels of lipid profiles and inflammatory cytokines. The potential mechanisms by which RVS mediated atherosclerosis were explored by western blot, real-time PCR assay, and immunofluorescence staining in mice and RAW264.7 macrophages.

RESULTS

Our data showed that RVS treatment reduced plaque areas in the aorta inner surface and the aortic sinus of ApoE-/- mice with high-fat diet. RVS markedly improved lipid profiles and reduced contents of inflammatory cytokines in the circulation. Then, results of Western blot showed that RVS increased the ratio LC3II/I and level of Beclin 1 and decreased the expression of p62 in aortic tissues, which might be attributed to suppression of PI3K/Akt/mTOR pathway, hinting that autophagy cascades were activated by RVS. Moreover, RVS raised the contents of ABCA1, ABCG1, Arg-1, CD206 and reduced iNOS expression of arterial wall, indicating that RVS promoted cholesterol efflux and M2 macrophage polarization. Similarly, we observed that RVS decreased lipids contents and inflammatory factors expressions in RAW264.7 cells stimulated by ox-LDL, accompanied by levels elevation of ABCA1, ABCG1, Arg-1, CD206 and content reduction of iNOS. These anti-atherosclerotic effects of RVS were abolished by 3-methyladenine intervention. Moreover, RVS could reverse the impaired autophagy flux in macrophages insulted by chloroquine. We further found that PI3K inhibitor LY294002 enhanced and agonist 740 Y-P weakened the autophagy-promoting roles of RVS, respectively.

CONCLUSIONS

Our study indicated that RVS exhibits atheroprotective effects involving regulation lipid accumulation and polarization conversion by improving autophagy initiation and development via suppressing PI3K/Akt/mTOR axis and enhancing autophagic flux in macrophages.

Atmospheric fine particulate matter exposure exacerbates atherosclerosis in apolipoprotein E knockout mice by inhibiting autophagy in macrophages via the PI3K/Akt/mTOR signaling pathway

Fine particulate matter (PM_2.5) exposure is intimately linked to atherosclerosis. Defective macrophages autophagy plays an accelerated role in advanced atherosclerosis, however, whether macrophages autophagy has been implicated in the development of PM_2.5-induced atherosclerosis has not been analyzed in full detail. Here we aimed to investigate the association between macrophages autophagy and PM_2.5-induced atherosclerosis, as well as the underlying mechanisms. ApoE^-/- mice were randomly exposed to PM_2.5 or filtered air for 3 months, macrophage RAW264.7 cells were isolated and were stimulated with PM_2.5 sample, selective inhibitors of PI3K/Akt/mTOR pathway LY294002, triciribine, and rapamycin were used in vitro and in vivo to detect the potential mechanisms. We found that PM_2.5 could significantly accelerate atherosclerotic plaque formation in ApoE^-/- mice, increase serum levels of TC and LDL-C, accelerate lipid accumulation in RAW264.7 cells, elevate serum and supernatant levels of IL-6, TNF-α and hs-CRP, decrease the number of autophagosomes in aortic plaque and RAW264.7 cells, reduce the expressions of autophagy-related genes LC3-I, LC3-II and Beclin1 in aortic tissues and RAW264.7 cells but increase the expression of autophagy regulator p62, elevate PI3K, Akt and mTOR distributions in aorta, and increase p-PI3K, p-Akt and p-mTOR protein expressions in aorta and RAW264.7 cells. However, these effects of PM_2.5 were aggravated with the administration of LY294002, triciribine, or rapamycin. This study indicated that the PI3K/Akt/mTOR pathway is involved in the suppression of autophagy induced by PM_2.5 in macrophages, the accelerated effect of PM_2.5 on atherosclerosis was mediated by down-regulation of macrophages autophagy via activating the PI3K/Akt/mTOR signaling pathway.

Therapeutic Potential of Hydroxysafflor Yellow A on Cardio-Cerebrovascular Diseases

The incidence rate of cardio-cerebrovascular diseases (CCVDs) is increasing worldwide, causing an increasingly serious public health burden. The pursuit of new promising treatment options is thus becoming a pressing issue. Hydroxysafflor yellow A (HSYA) is one of the main active quinochalcone C-glycosides in the florets of Carthamus tinctorius L., a medical and edible dual-purpose plant. HSYA has attracted much interest for its pharmacological actions in treating and/or managing CCVDs, such as myocardial and cerebral ischemia, hypertension, atherosclerosis, vascular dementia, and traumatic brain injury, in massive preclinical studies. In this review, we briefly summarized the mode and mechanism of action of HSYA on CCVDs based on these preclinical studies. The therapeutic effects of HSYA against CCVDs were presumed to reside mostly in its antioxidant, anti-inflammatory, and neuroprotective roles by acting on complex signaling pathways.

IMMUNEPOTENT CRP induces DAMPS release and ROS-dependent autophagosome formation in HeLa and MCF-7 cells

Background

IMMUNEPOTENT CRP (ICRP) can be cytotoxic to cancer cell lines. However, its widespread use in cancer patients has been limited by the absence of conclusive data on the molecular mechanism of its action. Here, we evaluated the mechanism of cell death induced by ICRP in HeLa and MCF-7 cells.

Methods

Cell death, cell cycle, mitochondrial membrane potential and ROS production were evaluated in HeLa and MCF-7 cell lines after ICRP treatment. Caspase-dependence and ROS-dependence were evaluated using QVD.oph and NAC pre-treatment in cell death analysis. DAMPs release, ER stress (eIF2-α phosphorylation) and autophagosome formation were analyzed as well. Additionally, the role of autophagosomes in cell death induced by ICRP was evaluated using SP-1 pre-treatment in cell death in HeLa and MCF-7 cells.

Results

ICRP induces cell death, reaching CC₅₀ at 1.25 U/mL and 1.5 U/mL in HeLa and MCF-7 cells, respectively. Loss of mitochondrial membrane potential, ROS production and cell cycle arrest were observed after ICRP CC₅₀ treatment in both cell lines, inducing the same mechanism, a type of cell death independent of caspases, relying on ROS production. Additionally, ICRP-induced cell death involves features of immunogenic cell death such as P-eIF2α and CRT exposure, as well as, ATP and HMGB1 release. Furthermore, ICRP induces ROS-dependent autophagosome formation that acts as a pro-survival mechanism.

Conclusions

ICRP induces a non-apoptotic cell death that requires an oxidative stress to take place, involving mitochondrial damage, ROS-dependent autophagosome formation, ER stress and DAMPs’ release. These data indicate that ICRP could work together with classic apoptotic inductors to attack cancer cells from different mechanisms, and that ICRP-induced cell death might activate an immune response against cancer cells.

Increased PIP3 activity blocks nanoparticle mRNA delivery

The biological pathways that affect drug delivery in vivo remain poorly understood. We hypothesized that altering cell metabolism with phosphatidylinositol (3,4,5)-triphosphate (PIP3), a bioactive lipid upstream of the metabolic pathway PI3K (phosphatidylinositol 3-kinase)/AKT/ mTOR (mammalian target of rapamycin) would transiently increase protein translated by nanoparticle-delivered messenger RNA (mRNA) since these pathways increase growth and proliferation. Instead, we found that PIP3 blocked delivery of clinically-relevant lipid nanoparticles (LNPs) across multiple cell types in vitro and in vivo. PIP3-driven reductions in LNP delivery were not caused by toxicity, cell uptake, or endosomal escape. Interestingly, RNA sequencing and metabolomics analyses suggested an increase in basal metabolic rate. Higher transcriptional activity and mitochondrial expansion led us to formulate two competing hypotheses that explain the reductions in LNP-mediated mRNA delivery. First, PIP3 induced consumption of limited cellular resources, "drowning out" exogenously-delivered mRNA. Second, PIP3 triggers a catabolic response that leads to protein degradation and decreased translation.

ROS-dependent inhibition of the PI3K/Akt/mTOR signaling is required for Oroxylin A to exert anti-inflammatory activity in liver fibrosis

More and more evidence showed that autophagy is an inflammation-related defense mechanism against a variety of diseases including liver fibrosis. However, the essential mechanisms remain poorly understood. In this study, we sought to elucidate the impact of Oroxylin A on autophagy and further to identify the potential mechanism of its anti-inflammatory activity. We found that Oroxylin A played a critical role in controlling inflammation in murine liver fibrosis. Moreover, Oroxylin A could inhibit the secretion of pro-inflammatory cytokines in activated hepatic stellate cell (HSCs). We previously reported that Oroxylin A can induce autophagy to alleviate the pathological changes of liver fibrosis and the activation of HSC. Here we further revealed that the inhibition of the PI3K/Akt/mTOR signaling was required for Oroxylin A to induce autophagy activation, which may be the underlying mechanism of the anti-inflammatory activity of Oroxylin A. Interestingly, mTOR overexpression completely impaired the Oroxylin A-mediated autophagy activation, and in turn, damaged the anti-inflammatory activity. Importantly, Oroxylin A inhibited PI3K/Akt/mTOR signaling by scavenging reactive oxygen species (ROS). ROS accumulation by buthionine sulfoximine (BSO) could abrogate the Oroxylin A-mediated ROS elimination, the inhibition of PI3K/Akt/mTOR signaling, and anti-inflammatory activities. Overall, our results provided reliable evidence for the molecular mechanism of Oroxylin A-mediated anti-fibrosis activity, and also identified a new target for drug therapy of liver fibrosis.

Cannabidiol alleviates hemorrhagic shock-induced neural apoptosis in rats by inducing autophagy through activation of the PI3K/AKT pathway

Recently, several studies have reported that the pharmacological effects exerted by cannabidiol (CBD) are partially related to the regulation of autophagy. Increasing evidence indicates that autophagy provides protection against ischemia-induced brain injury. However, the protective effect of CBD against mitochondrial-dependent apoptosis in hemorrhagic shock (HS)-induced brain injury has not been studied. In the present study, we observed the protective effects of CBD against neural mitochondrial-dependent apoptosis in a rat model of HS. In addition, CBD increased Beclin-1 and LC3II expression and reduced P62 expression, which were indicative of autophagy. CBD treatment attenuated the neural apoptosis induced by HS, as reflected by restoring mitochondrial dysfunction, downregulation of BAX, neuro-apoptosis ratio and NF-κB signaling activation, and upregulation of BCL2 in the cerebral cortex. Such protective effects were reversed by 3-Methyladenine, a specific autophagy inhibitor, indicating that the protective effects of CBD treatment involved autophagy. LY294002, a PI3K inhibitor, significantly inhibited CBD-induced autophagy, demonstrating that PI3K/AKT signaling is involved in the CBD's regulation of autophagy. Furthermore, we found that CBD treatment upregulated PI3K/AKT signaling via cannabinoid receptor 1. Therefore, these findings suggested that CBD treatment protects against cerebral injury induced by HS-mediated mitochondrial-dependent apoptosis by activating the PI3K/AKT signaling pathway to reinforce autophagy.

Plumbagin Enhances the Anticancer Efficacy of Cisplatin by Increasing Intracellular ROS in Human Tongue Squamous Cell Carcinoma

Cisplatin is widely used in the treatment of tongue squamous cell carcinoma (TSCC), but its clinical efficacy is limited by drug resistance and toxic side effects. Hence, a novel compound capable of enhancing the anticancer effect of cisplatin while reducing the side effects is urgently needed. We have previously shown that plumbagin (PLB), an anticancer phytochemical, is able to inhibit the growth of TSCC in vitro and in vivo. The objective of this study was to investigate the effect of PLB in reversing the resistance of TSCC to cisplatin as well as its molecular mechanisms. Here, we found that PLB enhances cisplatin-induced cytotoxicity, apoptosis, and autophagy in CAL27 and cisplatin-resistant CAL27/CDDP cells. PLB could inhibit the viability and growth of TSCC cells by increasing the production of intracellular reactive oxygen species (ROS). In addition, the combination treatment of PLB and cisplatin resulted in a synergistic inhibition of TSCC viability, apoptosis, and autophagy by increasing intracellular ROS, which may be achieved by activating JNK and inhibiting AKT/mTOR signaling pathways. Finally, the synergistic treatment was also demonstrated in vivo. Therefore, PLB combined with cisplatin is a potential therapeutic strategy against therapy TSCC cisplatin resistance.

Role of autophagy in the periodontal ligament reconstruction during orthodontic tooth movement in rats

Background/purpose

Autophagy, a lysosome-based degradation pathway that is reportedly activated by mechanical stress and nutrient deprivation, plays an important role in various physiological and pathological events. The present study investigated the level of autophagy and tumor necrosis factor-α(TNF-α) expression in the periodontal ligaments (PDLs) of Sprague-Dawley (SD) rats to analyze the involvement of autophagy and inflammatory cytokines in orthodontic tooth movement (OTM) and maintaining periodontal tissue homeostasis.

Materials and methods

SD rats (n = 100) were randomly divided into a control group (n = 10) and an experimental group (n = 90). An orthodontic appliance was placed in each rat in the experimental group, and 10 rats were randomly euthanized 15 min, 30 min, 1 h, 2 h, 4 h, 12 h, 1 d, 3 d and 7 d after mechanical loading. The OTM distance was then measured. Hematoxylin and eosin (HE) staining was used to analyze the morphology of the PDL. Immunohistochemical (IHC) staining and tartrate-resistant acid phosphatase (TRAP) staining were also performed.

Results

After the application of orthodontic force and under the dual effects of mechanical force and starvation caused by compressed vessels, the level of autophagy and TNF-α expression in the PDL fluctuated and exhibited a similar trend.

Conclusion

Our data suggest a significant correlation between the initiation of autophagy and TNF-α expression, which both exerted positive effects on PDL remodeling during OTM in rats.

Non-lethal sonodynamic therapy facilitates the M1-to-M2 transition in advanced atherosclerotic plaques via activating the ROS-AMPK-mTORC1-autophagy pathway

Emerging evidence indicates that macrophage functional polarization is critically involved in the development of atherosclerosis (AS). Here, we examined the role of 5-aminolaevulinic acid (ALA)-mediated non-lethal sonodynamic therapy (NL-SDT) in macrophage-subset polarization and atherosclerotic lesion stability and explored the potential underlying mechanisms. Using Western diet-fed apolipoprotein E (apoE)^−/− and green fluorescent protein (GFP)-positive bone marrow (BM) chimeric mouse models, we demonstrated that NL-SDT promoted phenotypic switching of both BM-derived and resident macrophages from M1 to M2 and significantly inhibited AS progression. Further mechanistic studies indicated that NL-SDT enhanced macrophage differentiation toward the M2 phenotype by activating the reactive oxygen species (ROS)–5′ AMP-activated protein kinase (AMPK)–mammalian target of rapamycin complex 1 (mTORC1)–autophagy signaling pathway in murine BM-derived M1 macrophages (BMDM1s). Moreover, NL-SDT drastically reduced lipid droplets, mainly by promoting apoAI-mediated cholesterol efflux in vitro. Specifically, administration of pharmacological inhibitors to the animal model showed a reciprocal effect on NL-SDT-induced macrophage polarization. These findings indicate that NL-SDT engages a virtuous cycle that enhances M1-to-M2 polarization, cholesterol efflux, and anti-inflammatory reactions in advanced plaque in vivo and in BMDM1s in vitro by activating the ROS–AMPK–mTORC1–autophagy pathway. This discovery might help elucidate the mechanism underlying NL-SDT as a potential treatment to prevent atherothrombotic events.

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NL-SDT enhances M1-to-M2 shift and significantly inhibits atherosclerosis progression in a mouse model.

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NL-SDT induces autophagy by activating the AMPK signaling pathway.

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M2-like macrophages promoted by NL-SDT facilitate cholesterol efflux and attenuate intracellular cholesterol deposition.

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The ROS–AMPK–mTORC1–autophagy pathway is critical for NL-SDT-mediated effects on M2 macrophage polarization.

Fe3O4 Nanoparticles Attenuated Salmonella Infection in Chicken Liver Through Reactive Oxygen and Autophagy via PI3K/Akt/mTOR Signaling

Recently nanomaterials have received substantial attention in biotechnology areas for their innovative properties in physical and chemical function. One of the most arrestive properties of nanomaterials that has been reported is their bacteriostatic activity. Our previous research found that Fe3O4 magnetic nanoparticles (Fe3O4-NPs) could effectively reduce the viability of intracellular Salmonella Enteritidis in chicken cells. There is an essential need to explore whether the bacteriostatic activity of Fe3O4-NPs is available in vivo. As an extension of this research, we conducted the present study to investigate the potential effect of Fe3O4-NPs used for S. Enteritidis control in chickens and to extensively investigate the underlying mechanisms in the process. The overall study included the evaluation of pathological sections, antioxidant status, inflammation, and the autophagy status of chicken liver, including the signaling pathway involved in the process. Results indicated that Fe3O4-NPs pretreatment can effectively inhibit the invasion of S. Enteritidis in chicken liver. Fe3O4-NPs pretreatment significantly increased reactive oxygen species (ROS) generation in chickens, including antioxidant enzyme activities. S. Enteritidis infection significantly increased the protein expression of the autophagy marker LC3. Additionally, the inflammation response and pathological changes caused by S. Enteritidis infection were alleviated by Fe3O4-NPs pretreatment. Phosphorylated mTOR was significantly increased in S. Enteritidis infected chickens, but showed no difference in chickens pretreated with Fe3O4-NPs. In summary, the results demonstrated that ROS and autophagy were involved in the inhibition of S. Enteritidis in chickens by Fe3O4-NPs pretreatment. The redox balance and inflammation response appeared normal in the process, as did the expression of the PI3K/Akt/mTOR signaling pathways. Taken together, our research demonstrate that the bacteriostatic activity of Fe3O4-NPs in chickens is avaliable and safe, which can be an alternative to antibiotics for bacterial inhibition in poultry industry.

Neuroprotective Effects of Gabapentin Against Cerebral Ischemia Reperfusion-Induced Neuronal Autophagic Injury via Regulation of the PI3K/Akt/mTOR Signaling Pathways

Gabapentin (GBP), an analgesic, adjunct antiepileptic, and migraine prophylactic drug, reduces neuronal injury induced by cerebral ischemia reperfusion (IR). However, the underlying biological molecular mechanism of GBP neuroprotection is not clear. In this study, we confirmed that dose-dependent (75 and 150 mg/kg) GBP treatment could significantly reduce IR-induced neuronal death. IR-induced neuronal death was inhibited by pretreatment with 150 mg/kg GBP in a middle cerebral artery occlusion rat model. In addition, 150 mg/kg GBP treatment remarkably promoted the levels of antioxidants and reduced the autophagy of neurons in the infarct penumbra. Moreover, the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway was activated by pretreatment with 150 mg/kg GBP, as detected by Western blot analyses. In vitro, pretreatment of PC12 cells with 450 µM GBP significantly reduced cell death induced by oxygen-glucose deprivation, increased antioxidant function, and reduced the levels of autophagy and reactive oxygen species via activation of the PI3K/Akt/mTOR pathway. This neuroprotection by GBP was inhibited significantly by 10 µM LY294002. In summary, dose-dependent pretreatment with GBP protected against cerebral IR injury via activation of the PI3K/Akt/mTOR pathway, which provided a neuroprotective function to inhibit oxidative stress-related neuronal autophagy.

MicroRNAs play an essential role in autophagy regulation in various disease phenotypes

Autophagy is a highly conserved catabolic process and fundamental biological process in eukaryotic cells. It recycles intracellular components to provide nutrients during starvation and maintains quality control of organelles and proteins. In addition, autophagy is a well-organized homeostatic cellular process that is responsible for the removal of damaged organelles and intracellular pathogens. Moreover, it also modulates the innate and adaptive immune systems. Micro ribonucleic acids (microRNAs) are a mature class of post-transcriptional modulators that are widely expressed in tissues and organs. And, it can suppress gene expression by targeting messenger RNAs for translational repression or, at a lesser extent, degradation. Research indicates that microRNAs regulate autophagy through different pathways, playing an essential role in the treatment of various diseases. It is an important regulator of fundamental cellular processes such as proliferation, autophagy, and cell apoptosis. In this review article, we first review the current knowledge of autophagy and the function of microRNAs. Then, we summarize the mechanism of autophagy and the signaling pathways related to autophagy by citing at least the main proteins involved in the different phases of the process. Second, we introduce other members of RNA and report some examples in various pathologies. Finally, we review the current literature regarding microRNA-based therapies for cancer, atherosclerosis, cardiac disease, tuberculosis, and viral diseases. MicroRNAs can cause autophagy upregulation or downregulation by targeting genes or affecting autophagy-related signaling pathways. Therefore, the microRNAs have a huge potential in autophagy regulation, and it is the function as diagnostic and prognostic markers.

Sirt3-dependent deacetylation of COX-1 counteracts oxidative stress-induced cell apoptosis

The mitochondrial complexes are prone to sirtuin (Sirt)3-mediated deacetylation modification, which may determine cellular response to stimuli, such as oxidative stress. In this study, we show that the cytochrome c oxidase (COX)-1, a core catalytic subunit of mitochondrial complex IV, was acetylated and deactivated both in 2,2'-azobis(2-amidinopropane) dihydrochloride-treated NIH/3T3 cells and hydrogen peroxide-treated primary neuronal cells, correlating with apoptotic cell death induction by oxidative stress. Inhibition of Sirt3 by small interfering RNA or the inhibitor nicotinamide induced accumulation of acetylation of COX-1, reduced mitochondrial membrane potential, and increased cell apoptosis. In contrast, overexpression of Sirt3 enhanced deacetylation of COX-1 and inhibited oxidative stress-induced apoptotic cell death. Significantly, rats treated with ischemia/reperfusion injury, a typical oxidative stress-related disease, presented an inhibition of Sirt3-induced hyperacetylation of COX-1 in the brain tissues. Furthermore, K13, K264, K319, and K481 were identified as the acetylation sits of COX-1 in response to oxidative stress. In conclusion, COX-1 was discovered as a new deacetylation target of Sirt3, indicating that the Sirt3/COX-1 axis is a promising therapy target of stress-related diseases.-Tu, L.-F., Cao, L.-F., Zhang, Y.-H., Guo, Y.-L., Zhou, Y.-F., Lu, W.-Q., Zhang, T.-Z., Zhang, T., Zhang, G.-X., Kurihara, H., Li, Y.-F., He, R.-R. Sirt3-dependent deacetylation of COX-1 counteracts oxidative stress-induced cell apoptosis.

Liensinine inhibited gastric cancer cell growth through ROS generation and the PI3K/AKT pathway

Liensinine, an isoquinoline alkaloid extracted from the seed embryo of Nelumbo nucifera Gaertn, has been shown to exhibit various phrenological effects, including anti‑cancer activity. The aim of this study is to investigate the effects and mechanisms of liensinine in human gastric cancer cells. In this study, we found liensinine can significantly inhibit gastric cancer cell proliferation in vitro and in vivo. Liensinine inducedgastric cancer cell apoptosis by increasing cleaved PARP, caspased 3 and caspased 9. Moreover, liensinine induced cycle arrest by downregulatingcyclinD1/cyclin‑dependent kinase4 and phosphorylated protein kinase B. Furthermore, we found liensinine increases ROS levels and inhibits the PI3K/AKT pathway. These data suggested that liensinine might represent a novel and effective agent against gastric cancer.

Sonodynamic therapy inhibits palmitate-induced beta cell dysfunction via PINK1/Parkin-dependent mitophagy

In type 2 diabetes mellitus (T2DM), the overload of glucose and lipids can promote oxidative stress and inflammatory responses and contribute to the failure of beta cells. However, therapies that can modulate the function of beta cells and thus prevent their failure have not been well explored. In this study, beta cell injury model was established with palmitic acid (PA) to simulate the lipotoxicity (high-fat diet) found in T2DM. Sonodynamic therapy (SDT), a novel physicochemical treatment, was applied to treat injured beta cells. We found that SDT had specific effects on mitochondria and induced transient large amount of mitochondrial reactive oxygen species (ROS) production in beta cells. SDT also improved the morphology and function of abnormal mitochondria, inhibited inflammatory response and reduced beta cell dysfunction. The improvement of mitochondria was mediated by PINK1/Parkin-dependent mitophagy. Additionally, SDT rescued the transcription of PINK1 mRNA which was blocked by PA treatment, thus providing abundant PINK1 for mitophagy. Moreover, SDT also increased insulin secretion from beta cells. The protective effects of SDT were abrogated when mitophagy was inhibited by cyclosporin A (CsA). In summary, SDT potently inhibits lipotoxicity-induced beta cell failure via PINK1/Parkin-dependent mitophagy, providing theoretical guidance for T2DM treatment in aspects of islet protection.

Shen-Yuan-Dan Capsule Attenuates Atherosclerosis and Foam Cell Formation by Enhancing Autophagy and Inhibiting the PI3K/Akt/mTORC1 Signaling Pathway

Background and Aim: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling pathway plays a crucial role in autophagy and inflammation. Our previous studies demonstrated that Shen-Yuan-Dan Capsule (SYDC), a Chinese medicine used for treating angina pectoris, has anti-atherosclerotic and anti-inflammatory effects in mice. However, its effects on autophagy and the PI3K/Akt/mTORC1 signaling pathway remain unclear. This study aimed to explore the effects of SYDC on autophagy and PI3K/Akt/mTORC1 signaling in the apolipoprotein E knockout (ApoE^−/−) mouse model and in macrophage-derived foam cells to delineate the underlying mechanism.

Methods: After 6 weeks of high-fat diet, ApoE^–/– mice were randomly grouped into control, Lipitor, low-SYDC (SYDC-L), middle-SYDC (SYDC-M), and high-SYDC (SYDC-H) groups (n = 10). The mice were intragastrically administered the respective treatment for 6 weeks. Murine RAW264.7 cells were stimulated with oxidized low-density lipoprotein (ox-LDL) (80 µg/ml) for 24 h and then pretreated with SYDC freeze-dried powder for another 24 h. Cells treated with SYDC were co-cultured for 24 h with LY294002, tricirbine, and rapamycin to investigate the effects on the PI3K/Akt/mTORC1 signaling pathway.

Results: SYDC ameliorated blood lipid levels, reduced the atherosclerotic index and plaque areas in the aortic root in mice, and inhibited total cholesterol (TC) levels and cholinesterase (ChE)/TC ratios in ox-LDL stimulated macrophages. Moreover, SYDC up-regulated Beclin1 and LC3II/I proteins in mice and in the ox-LDL–stimulated macrophages. Moreover, SYDC inhibited AKT phosphorylation at Ser473 and mTOR phosphorylation at Ser2448 in mice and in ox-LDL–stimulated macrophages. Furthermore, SYDC’s inhibitory of ChE/TC ratios in ox-LDL–stimulated macrophages was not changed by selective inhibition of the PI3K/Akt/mTORC1 pathway.

Conclusions: Our results highlight that SYDC treatment attenuates foam cell formation by promoting autophagy via inhibiting activation of the PI3K/Akt/mTORC1 signaling pathway. This study provides new insights into the molecular mechanism underlying SYDC’s therapeutic potential for treating atherosclerosis.

Exogenous Hydrogen Sulfide Regulates the Growth of Human Thyroid Carcinoma Cells

Hydrogen sulfide (H₂S) is involved in the development and progression of many types of cancer. However, the effect and mechanism of H₂S on the growth of human thyroid carcinoma cells remain unknown. In the present study, we found that the proliferation, viability, migration, and invasion of human thyroid carcinoma cells were enhanced by 25–50 μM NaHS (an H₂S donor) and inhibited by 200 μM NaHS. However, H₂S showed no obvious effects on the proliferation, viability, and migration of human normal thyroid cells. Administration of 50 μM NaHS increased the expression levels of CBS, SQR, and TST, while 200 μM NaHS showed reverse effects in human thyroid carcinoma cells. After treatment with 25-50 μM NaHS, the ROS levels were decreased and the protein levels of p-PI3K, p-AKT, p-mTOR, H-RAS, p-RAF, p-MEK1/2, and p-ERK1/2 were increased, whereas 200 μM NaHS exerted opposite effects in human thyroid carcinoma cells. Furthermore, 1.4-2.8 mg/kg/day NaHS promoted the tumor growth and blood vessel formation in human thyroid carcinoma xenograft tumors, while 11.2 mg/kg/day NaHS inhibited the tumor growth and angiogenesis. In conclusion, our results demonstrate that exogenous H₂S regulates the growth of human thyroid carcinoma cells through ROS/PI3K/Akt/mTOR and RAS/RAF/MEK/ERK signaling pathways. Novel H₂S-releasing donors/drugs can be designed and applied for the treatment of thyroid cancer.

Hydroxysafflor yellow A (HSYA) alleviates apoptosis and autophagy of neural stem cells induced by heat stress via p38 MAPK/MK2/Hsp27-78 signaling pathway

This study aimed to explore mechanisms of the effects of hydroxysafflor yellow A (HSYA) on neural stem cells (NSCs) after heat stress (HS). Rat NSCs cells were cultured at 42 °C to impose heat stress. Cell counting kit-8 and Edu assay were used to analyze NSC proliferation. Annexin V/PI apoptosis kit was used to detect NSC apoptosis. Expression and phosphorylation of autophagy and apoptosis-associated proteins were determined by western blotting. We showed that HSYA significantly promoted proliferation and attenuated apoptosis of NSCs after heat stress. HSYA also increased Bcl-2 expression but decreased the expression of Bax and cleaved caspase-3 in NSCs induced by heat stress. In addition, HSYA decreased p38 and Hsp27-78 phosphorylation and MK-2 expression after heat stress, which was consistent with NSCs treated with SB203850 treatment or p38 knockdown. Furthermore, we demonstrated that heat stress increased LC3-II expression and mTOR phosphorylation, and decreased the expression of p62 in NSCs, while HSYA, SB203850 treatment or p38 knockdown reversed these alterations. In conclusion, HSYA significantly reversed the apoptosis and autophagy of NSCs induced by heat stress (P < 0.05), via downregulating MK2 expression and p38 and Hsp27-78 phosphorylation.

Pyropheophorbide-α methyl ester-mediated photodynamic therapy induces apoptosis and inhibits LPS-induced inflammation in RAW264.7 macrophages

BACKGROUND

This study aimed to determine the effect of pyropheophorbide-α methyl ester (MPPa)-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and inflammation of murine macrophage RAW264.7 cells.

METHODS

Uptake and subcellular localization of MPPa was detected by flow cytometry and confocal fluorescence microscope. Cell viability was assessed by CCK-8; ROS levels were assessed by DCFH-DA. Cell apoptosis was measured by flow cytometry and Hoechst 33342 staining, whereas mitochondrial membrane potential was detected by JC-1 staining. Secretion of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) was determined using ELISA kits. Caspase-3, cleaved caspase-3, procaspase-9, cleaved caspase-9, PARP, cleaved PARP, Bcl-2, Bax, NF-κB p-p65, p-IKKα/β, and p-IκBα were measured by western blotting. Nuclear factor κB (NF-κB)-p65 nuclear translocation was observed by immunofluorescence.

RESULTS

MPPa -PDT influenced cell viability in a light dose-dependent manner. It induced ROS formation and RAW264.7 cell apoptosis. It also increased the expression of cleaved caspase-3, cleaved caspase-9, cleaved PARP and Bax, decreased the expression of Bcl-2. While TNF-α, IL-1β, and IL-6 increased in LPS group (model of inflammation), it deceased in LPS-MPPa-PDT group. NF-κB p-p65, p-IKKα/β, and p-IκBα had higher expression in LPS group while that reduced in LPS-MPPa-PDT group. Simultaneously, MPPa-PDT inhibited nuclear translocation of NF-κB-p65 caused by LPS.

CONCLUSIONS

MPPa-PDT can induce apoptosis and attenuate inflammation in mouse RAW264.7 macrophages, thereby suggesting a promising therapy for atherosclerosis.

Hydroxysafflor Yellow A: A Promising Therapeutic Agent for a Broad Spectrum of Diseases

Hydroxysafflor yellow A (HSYA) is one of the major bioactive and water-soluble compounds isolated from Carthami Flos, the flower of safflower (Carthamus tinctorius L.). As a natural pigment with favorable medical use, HSYA has gained extensive attention due to broad and effective pharmacological activities since first isolation in 1993. In clinic, the safflor yellow injection which mainly contains about 80% HSYA was approved by the China State Food and Drug Administration and used to treat cardiac diseases such as angina pectoris. In basic pharmacology, HSYA has been proved to exhibit a broad spectrum of biological effects that include, but not limited to, cardiovascular effect, neuroprotection, liver and lung protection, antitumor activity, metabolism regulation, and endothelium cell protection. Although a great number of studies have been carried out to prove the pharmacological effects and corresponding mechanisms of HYSA, a systemic review of HYSA has not yet been seen. Here, we provide a comprehensive summarization of the pharmacological effects of HYSA. Together with special attention to mechanisms of actions, this review can serve as the basis for further researches and developments of this medicinal compound.

Atheroprotective effects and molecular targets of bioactive compounds from traditional Chinese medicine

Traditional Chinese medicine (TCM) has served the Chinese people since antiquity, and is playing an important role in today's healthcare. However, there has been controversy in the use of these traditional herbs due to unclear components and absence of scientific proof. As China plans to modernize traditional medicine, successful attempts to better understand the molecular mechanisms of TCM have been made by focusing on isolating active ingredients from these remedies. In this review, we critically examined the current evidence on atheroprotective effects of bioactive compounds from TCM using in vitro or in vivo models in the past two decades. A total of 47 active compounds were included in our review, which were introduced in the order of chemical structures, source, model, efficacy and mechanism. Notablely, this review highlighted the cellular and molecular mechanisms of these active compounds in prevention and treatment of atherosclerosis. Two compounds were also involved in double-blind, randomized, placebo-controlled clinical trials (RCTs). Besides, we introduced the legislations of the People's Republic of China ensuring quality and safety of products used in TCM. In summary, studies on bioactive compounds from TCM will provide a new approach for better management of atherosclerosis.

Studies on the non-invasive anticancer remedy of the triple combination of epigallocatechin gallate, pulsed electric field, and ultrasound

Cancer is one of the most troublesome diseases and a leading cause of death worldwide. Recently, novel treatments have been continuously developed to improve the disadvantages of conventional therapies, such as prodigious expenses, unwanted side effects, and tumor recurrence. Here, we provide the first non-invasive treatment that has combined epigallocatechin gallate (EGCG), the most abundant catechin in green tea, with a low strength pulsed electric field (PEF) and a low energy ultrasound (US). It has been observed that the cell viability of human pancreatic cancer PANC-1 was decreased approximately to 20% of the control after this combination treatment for 72 h. Besides, the combined triple treatment significantly reduced the high tolerance of HepG2 cells to the EGCG-induced cytotoxicity and similarly exhibited compelling proliferation-inhibitory effects. We also found the combined triple treatment increased the intracellular reactive oxygen species (ROS) and acidic vesicles, and the EGCG-induced inhibition of Akt phosphorylation was dramatically intensified. In this study, the apoptosis inhibitor Z-VAD-FMK and the autophagy inhibitor 3-MA were, respectively, shown to attenuate the anticancer effects of the triple treatment. This indicates that the triple treatment-induced autophagy was switched from cytoprotective to cytotoxic, and hence, cooperatively caused cell death with the apoptosis. Since the EGCG is easily accessible from the green tea and mild for a long-term treatment, and the non-invasive physical stimulations could be modified to focus on a specific location, this combined triple treatment may serve as a promising strategy for anticancer therapy.