Targeted delivery of triptolide by dendritic cell-derived exosomes for colitis and rheumatoid arthritis therapy in murine models

Extracellular vesicles as therapeutic agents in rheumatoid arthritis: a systematic review of current evidence

Rheumatoid arthritis (RA) is defined as a chronic autoimmune disease that severely influences a patient's quality of life. Extracellular vesicles (EVs) have gained much attention in recent years as one of the most potent therapeutic agents for the treatment of RA. A systematic review was performed with the purpose of assessing the current evidence relating to the therapeutic applications of EVs in RA. The systematic search was performed in the databases of PubMed, Scopus, and Web of Science, from inception times to September 2024. All studies investigating the use of EVs for the treatment of RA were included. The quality appraisal of selected articles and data extraction regarding EV characteristics, therapeutic applications, and associated outcomes were performed. Of the 1418 initially identified articles, 59 studies met inclusion criteria. Regarding their cellular origins, most EVs were derived from mesenchymal stem cells, followed by immune cells. The main therapeutic mechanisms included modulation of the immune response, reduction of inflammation, and repair of tissues. Recent trends are toward increasing interest in engineered EVs and combination therapies. Indeed, most studies reported positive outcomes with regard to lowered inflammation and improved joint function. On the other hand, standardization of the metrics of evaluation considerably varied between different studies. EVs are promising therapeutic agents in the treatment of RA by modulating immune responses. Standardization, delivery systems, and clinical translation are challenges yet to be overcome. Future studies will be directed to optimize EV engineering, targeted delivery systems, and large-scale clinical trials.

The potential of autologous patient-derived circulating extracellular vesicles to improve drug delivery in rheumatoid arthritis

Recognizing the need for innovative therapeutic approaches in the management of autoimmune diseases, our current investigation explores the potential of autologous extracellular vesicles (EVs), derived from the blood of rheumatoid arthritis patients, to serve as therapeutic vectors to improve drug delivery. We found that circulating EVs derived from arthritic mice (collagen-induced arthritis model) express the joint/synovia homing receptor, αVβ3 integrin. Importantly, both autologous labeled EVs, derived from the blood of arthritic mice (collagen antibody-induced arthritis model) and healthy mice-derived EVs, exhibit targeted migration toward inflamed synovia without infiltrating healthy joints, as demonstrated by an in vivo imaging system. Furthermore, EVs derived from plasma of rheumatoid arthritis patients show an overexpression of αV integrin and are effectively taken up by lipopolysaccharides/tumor necrosis factor alpha (TNFα)-induced activated human synovial cell line in vitro, although interestingly the uptake of healthy EVs was found to be significantly increased. Notably, arthritic mice-derived circulating EVs, strongly express murine glucose transporter 1, which in turn can facilitate their binding to glucose-coated gold nanoparticles (previously shown to be conjugated with drugs for improved drug delivery). The significance of our results, lies in the identification of autologous tissue homing EVs as promising vectors, offering a novel avenue to enhance targeted delivery of anti-inflammatory/rheumatic drugs in rheumatoid arthritis treatment.

The Role of Exosomes in Central Immune Tolerance and Myasthenia Gravis

BACKGROUND

Immune homeostasis plays a crucial role in immunology andis dependent on both central and peripheral tolerance. Centraltolerance and peripheral tolerance occur in the thymus and thesecondary lymphoid tissues, respectively. Tolerance breakdown andimmune regulation defects can lead to autoimmune disorders. In thisreview article, we aimed to describe the role of exosomes inregulating central tolerance and provide a summary of their effectson the pathogenesis, diagnosis, and therapeutic potential inmyasthenia gravis (MG).

METHODS

Articles for this review wereidentified using the PubMed database.

RESULTS

As the primarylymphoid organ, the thymus is responsible for building an immunecompetent, yet self-tolerant of T-cell population. Thymic statesinclude thymoma, thymic hyperplasia, and thymic atrophy, which canexert a significant influence on the central immune tolerance andrepresent specific characteristics of MG. Previous studies have foundthat exosomes derived from human thymic epithelial cells carryantigen-presenting molecules and a wide range of tissue restrictedantigens, which may indicate a vital role of thymic exosomes in MG.Besides, exosomal miRNAs and lncRNAs may also play a critical role inthe pathophysiology of MG.

CONCLUSION

This review provides thetherapeutic and diagnostic potential of exosomes in MG patients.

Triptolide Causes Spermatogenic Disorders by Inducing Apoptosis in the Mitochondrial Pathway of Mouse Testicular Spermatocytes

Triptolide (TP) is a diterpenoid compound extracted from the traditional Chinese medicinal herb Tripterygium wilfordii. It has antitumor and anti-inflammatory effects and stimulates immunity. However, its serious side effects, especially reproductive toxicity, limit its clinical application. This study employed a testicular injury model established by intraperitoneally injecting TP (0.2 mg/kg) in C57BL/6J male mice (age = 7-8 weeks) for 14 days. The control and TP mice's testicular tissues were subjected to transcriptome sequencing to assess potential testicular damage mechanisms. Based on the transcriptome sequencing results and relevant literature reports, further experiments were performed. In addition, to alleviate triptolide-induced testicular damage, we treated the mice with N-acetyl-L-cysteine (NAC). The acquired data revealed that compared with the control mice, the TP-treated mice's testes indicated severe damage. Transcriptome sequencing identified differentially expressed genes that showed enrichment in cell differentiation, apoptotic process, cell cycle, glutathione (GSH) metabolism, and the p53 signaling pathway. Furthermore, TUNEL assays and Western blot analysis showed that in the TP mice's testicular tissues, the spermatocytes had mitochondrial pathway apoptosis as well as abnormal mitochondrial morphology and structure. Triptolide induces oxidative stress in testicular tissue by enhancing pro-oxidative systems and inhibiting antioxidant systems. NAC reduced testicular damage and apoptosis by alleviating TP-induced oxidative stress. This study also employed a GC2 cell line for in-vitro analyses, and the results were consistent with the in vivo experiments. This study provides evidence for alleviating TP's adverse effects on the male reproductive system for better clinical application.

Natural product pharmacology: the British Journal of Pharmacology perspective

Natural products (NPs) have long been used as a rich source of bioactive compounds for drug development. Recent technological advancements have revitalised natural products research as evidenced by increased publications in this field. In this editorial review, we highlight key points from the 2020 British Journal of Pharmacology (BJP) practical guide, which outlines standards for natural products research reports, and provide papers published in BJP between years 2020 to 2023 that demonstrate adherence to these guidelines. Looking ahead, we discuss the potential of chemical proteomics approaches to elucidate natural products mechanisms of action and identify therapeutic targets for future research. By fostering innovation, we aim to advance natural products research and contribute to the development of novel therapeutics that will have a significant impact on healthcare.

The role of cGAS-STING signaling in rheumatoid arthritis: from pathogenesis to therapeutic targets

Rheumatoid arthritis (RA) is a systemic autoimmune disease primarily characterized by erosive and symmetric polyarthritis. As a pivotal axis in the regulation of type I interferon (IFN-I) and innate immunity, the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway has been implicated in the pathogenesis of RA. This pathway mainly functions by regulating cell survival, pyroptosis, migration, and invasion. Therefore, understanding the sources of cell-free DNA and the mechanisms underlying the activation and regulation of cGAS-STING signaling in RA offers a promising avenue for targeted therapies. Early detection and interventions targeting the cGAS-STING signaling are important for reducing the medical burden on individuals and healthcare systems. Herein, we review the existing literature pertaining to the role of cGAS-STING signaling in RA, and discuss current applications and future directions for targeting the cGAS-STING signaling in RA treatments.

Extracellular vesicles for the treatment of ulcerative colitis: A systematic review and meta-analysis of animal studies

Background

Extracellular vesicles (EVs) are being considered as a potential therapeutic option for ulcerative colitis (UC), and numerous preclinical studies have been conducted on the use of EVs for UC.

Methods

A systematic review was conducted to compare the therapeutic effects of mammalian EVs and placebo on UC in animal models, along with a meta-analysis comparing naïve (unmodified) EVs and placebo. The search was performed in four databases (PubMed, Web of Science, Scopus, and EMBASE) up to September 13th, 2023. The primary outcomes included disease activity index (DAI), colonic mucosal damage index (CMDI), and adverse effects (PROSPERO ID: CRD42023458039).

Results

A total of 69 studies were included based on pre-determined criteria, involving 1271 animals. Of these studies, 51 measured DAI scores, with 98 % reporting that EVs could reduce DAI scores. Additionally, 5 studies reported CMDI and all showed that EVs could significantly reduce CMDI. However, only 3 studies assessed adverse effects and none reported any significant adverse effects. The meta-analysis of these studies (40 studies involving 1065 animals) revealed that naïve EVs could significantly decrease the DAI score (SMD = -3.00; 95 % CI: -3.52 to -2.48) and CMDI (SMD = -2.10; 95 % CI: -2.85 to -1.35).

Conclusion

The results indicate that mammalian EVs have demonstrated therapeutic benefits in animal models of UC; however, the safety profile of EVs remains inadequate which highlights the need for further research on safety outcomes.

Advancements in extracellular vesicle targeted therapies for rheumatoid arthritis: insights into cellular origins, current perspectives, and emerging challenges

Rheumatoid arthritis (RA) remains a challenging chronic autoimmune disorder characterized by persistent joint inflammation and damage. While modern regenerative strategies, encompassing cell/stem cell-based therapies, gene therapy, and tissue engineering, have advanced tissue repair efforts, a definitive cure for RA remains elusive. Consequently, there is growing interest in developing targeted therapies that directly address the underlying mechanisms driving RA pathogenesis, such as extracellular vesicles (EVs). These small membrane-bound particles can modulate immune responses within the inflammatory microenvironment of damaged cartilage. To launch the clinical potential of EVs, they can be isolated from various cell types through several techniques. EVs can carry various bioactive molecules and anti-inflammatory or pro-regenerative drugs, deliver them directly to the affected joints, and affect the behavior of injured cells, making them a compelling choice for targeted therapy and drug delivery in RA patients. However, there are still several challenges and limitations associated with EV-based therapy, including the absence of standardized protocols for EV isolation, characterization, and delivery. This review provides a comprehensive overview of the cellular sources of EVs in RA and delves into their therapeutic potential and the hurdles they must overcome.

Recent developments and new directions in the use of natural products for the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) represents a significant global health challenge, and there is an urgent need to explore novel therapeutic interventions. Natural products have demonstrated highly promising effectiveness in the treatment of IBD.

PURPOSE

This study systematically reviews the latest research advancements in leveraging natural products for IBD treatment.

METHODS

This manuscript strictly adheres to the PRISMA guidelines. Relevant literature on the effects of natural products on IBD was retrieved from the PubMed, Web of Science and Cochrane Library databases using the search terms "natural product," "inflammatory bowel disease," "colitis," "metagenomics", "target identification", "drug delivery systems", "polyphenols," "alkaloids," "terpenoids," and so on. The retrieved data were then systematically summarized and reviewed.

RESULTS

This review assessed the different effects of various natural products, such as polyphenols, alkaloids, terpenoids, quinones, and others, in the treatment of IBD. While these natural products offer promising avenues for IBD management, they also face challenges in terms of clinical translation and drug discovery. The advent of metagenomics, single-cell sequencing, target identification techniques, drug delivery systems, and other cutting-edge technologies heralds a new era in overcoming these challenges.

CONCLUSION

This paper provides an overview of current research progress in utilizing natural products for the treatment of IBD, exploring how contemporary technological innovations can aid in discovering and harnessing bioactive natural products for the treatment of IBD.

Updates on the Pathophysiology and Therapeutic Potential of Extracellular Vesicles with Focus on Exosomes in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an incurable autoimmune disease with high morbidity and socioeconomic burden. Advances in therapeutics have improved patients' quality of life, however due to the complex disease pathophysiology and heterogeneity, 30% of patients do not respond to treatment. Understanding how different genetic and environmental factors contribute to disease initiation and development as well as uncovering the interactions of immune components is key to the implementation of effective and safe therapies. Recently, the role of extracellular vesicles (EVs) in RA development and possible treatment has been an area of interest. EVs are small lipid-bound entities, often containing genetic material, proteins, lipids and amino acids, facilitating paracrine intercellular communication. They are secreted by all cells, and it is believed that they possess regulatory functions due to high complexity and functional diversity. Although it has been shown that EVs participate in RA pathophysiology, through immune modulation, their exact role remains elusive. Furthermore, EVs could be a promising therapeutic agent in various diseases including RA, due to their biocompatibility, low toxicity and possible manipulation, but further research is required in this area. This review provides a comprehensive discussion of disease pathophysiology and summarizes the latest knowledge regarding the role and therapeutic potential of EVs in RA.

The science of exosomes: Understanding their formation, capture, and role in cellular communication

Extracellular vesicles (EVs) serve as a crucial method for transferring information among cells, which is vital in multicellular organisms. Among these vesicles, exosomes are notable for their small size, ranging from 20 to 150 nm, and their role in cell-to-cell communication. They carry lipids, proteins, and nucleic acids between cells. The creation of exosomes begins with the inward budding of the cell membrane, which then encapsulates various macromolecules as cargo. Once filled, exosomes are released into the extracellular space and taken up by target cells via endocytosis and similar processes. The composition of exosomal cargo varies, encompassing diverse macromolecules with specific functions. Because of their significant roles, exosomes have been isolated from various cell types, including cancer cells, endothelial cells, macrophages, and mesenchymal cells, with the aim of harnessing them for therapeutic applications. Exosomes influence cellular metabolism, and regulate lipid, glucose, and glutamine pathways. Their role in pathogenesis is determined by their cargo, which can manipulate processes such as apoptosis, proliferation, inflammation, migration, and other molecular pathways in recipient cells. Non-coding RNA transcripts, a common type of cargo, play a pivotal role in regulating disease progression. Exosomes are implicated in numerous biological and pathological processes, including inflammation, cancer, cardiovascular diseases, diabetes, wound healing, and ischemic-reperfusion injury. As a result, they hold significant potential in the treatment of both cancerous and non-cancerous conditions.

Different origin-derived exosomes and their clinical advantages in cancer therapy

Exosomes, as a class of small extracellular vesicles closely related to the biological behavior of various types of tumors, are currently attracting research attention in cancer diagnosis and treatment. Regarding cancer diagnosis, the stability of their membrane structure and their wide distribution in body fluids render exosomes promising biomarkers. It is expected that exosome-based liquid biopsy will become an important tool for tumor diagnosis in the future. For cancer treatment, exosomes, as the "golden communicators" between cells, can be designed to deliver different drugs, aiming to achieve low-toxicity and low-immunogenicity targeted delivery. Signaling pathways related to exosome contents can also be used for safer and more effective immunotherapy against tumors. Exosomes are derived from a wide range of sources, and exhibit different biological characteristics as well as clinical application advantages in different cancer therapies. In this review, we analyzed the main sources of exosomes that have great potential and broad prospects in cancer diagnosis and therapy. Moreover, we compared their therapeutic advantages, providing new ideas for the clinical application of exosomes.

Bergenin attenuates triptolide-caused premature ovarian failure in mice based on the antioxidant activity

Tripterygium wilfordii (TW) preparations have been utilized in China for treating rheumatoid arthritis and autoimmune diseases. However, their clinical use is limited due to reproductive toxicity, notably premature ovarian failure (POF). Our study aimed to investigate the effect and mechanism of bergenin in attenuating POF induced by triptolide in mice. POF was induced in female ICR mice via oral triptolide administration (50 μg/kg) for 60 days. Mice received bergenin (25, 50, 100 mg/kg, i.g.) or estradiol valerate (EV) (0.1 mg/kg, i.g.) daily, 1 h before triptolide treatment. In vitro, ovarian granulosa cells (OGCs) were exposed to triptolide (100 nM) and bergenin (1, 3, 10 μM). Antioxidant enzyme activity, protein expression, apoptosis rate, and reactive oxygen species (ROS) levels were assessed. The results showed that triptolide-treated mice exhibited evident atrophy, along with an increase in atretic follicles. Bergenin (50, 100 mg/kg) and EV (0.1 mg/kg), orally administered, exerted significant anti-POF effect. Bergenin and EV also decreased apoptosis in mouse ovaries. In vitro, bergenin (1, 3, 10 μM) attenuated triptolide-induced OGCs apoptosis by reducing levels of apoptosis-related proteins. Additionally, bergenin reduced oxidative stress through downregulation of antioxidant enzymes activity and overall ROS levels. Moreover, the combined use with Sh-Nrf2 resulted in a reduced protection of bergenin against triptolide-induced apoptosis of OGCs. Together, bergenin counteracts triptolide-caused POF in mice by inhibiting Nrf2-mediated oxidative stress and preventing OGC apoptosis. Combining bergenin with TW preparations may effectively reduce the risk of POF.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Collision of herbal medicine and nanotechnology: a bibliometric analysis of herbal nanoparticles from 2004 to 2023

BACKGROUND

Herbal nanoparticles are made from natural herbs/medicinal plants, their extracts, or a combination with other nanoparticle carriers. Compared to traditional herbs, herbal nanoparticles lead to improved bioavailability, enhanced stability, and reduced toxicity. Previous research indicates that herbal medicine nanomaterials are rapidly advancing and making significant progress; however, bibliometric analysis and knowledge mapping for herbal nanoparticles are currently lacking. We performed a bibliometric analysis by retrieving publications related to herbal nanoparticles from the Web of Science Core Collection (WoSCC) database spanning from 2004 to 2023. Data processing was performed using the R package Bibliometrix, VOSviewers, and CiteSpace.

RESULTS

In total, 1876 articles related to herbal nanoparticles were identified, originating from various countries, with China being the primary contributing country. The number of publications in this field increases annually. Beijing University of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, and Saveetha University in India are prominent research institutions in this domain. The Journal "International Journal of Nanomedicine" has the highest number of publications. The number of authors of these publications reached 8234, with Yan Zhao, Yue Zhang, and Huihua Qu being the most prolific authors and Yan Zhao being the most frequently cited author. "Traditional Chinese medicine," "drug delivery," and "green synthesis" are the main research focal points. Themes such as "green synthesis," "curcumin," "wound healing," "drug delivery," and "carbon dots" may represent emerging research areas.

CONCLUSIONS

Our study findings assist in identifying the latest research frontiers and hot topics, providing valuable references for scholars investigating the role of nanotechnology in herbal medicine.

Emerging role of exosomes in ulcerative colitis: Targeting NOD-like receptor family pyrin domain containing 3 inflammasome

Ulcerative colitis (UC) is a chronic recurrent inflammatory bowel disease. Despite ongoing advances in our understanding of UC, its pathogenesis is yet unelucidated, underscoring the urgent need for novel treatment strategies for patients with UC. Exosomes are nanoscale membrane particles that mediate intercellular communication by carrying various bioactive molecules, such as proteins, RNAs, DNA, and metabolites. The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a cytosolic tripartite protein complex whose activation induces the maturation and secretion of proinflammatory cytokines interleukin-1β (IL-1β) and IL-18, triggering the inflammatory response to a pathogenic agent or injury. Growing evidence suggests that exosomes are new modulators of the NLRP3 inflammasome, with vital roles in the pathological process of UC. Here, recent evidence is reviewed on the role of exosomes and NLRP3 inflammasome in UC. First, the dual role of exosomes on NLRP3 inflammasome and the effect of NLRP3 inflammasome on exosome secretion are summarized. Finally, an outlook on the directions of exosome-NLRP3 inflammasome crosstalk research in the context of UC is proposed and areas of further research on this topic are highlighted.

Recent advances in extracellular vesicle engineering and its applications to regenerative medicine

Extracellular vesicles (EVs) are nanosized particles that are released from cells and reflect the characteristics of the mother cell. Recently, the EVs have been used in several types of studies across many different fields. In the field of EV research, multiple cell culture and EV isolation techniques have been highlighted in importance. Various strategies, including exclusive component culture media, three-dimensional (3D) cultures, and hypoxic conditions, have been proposed for the cell culture to control function of the EVs. Ultracentrifugation, ultrafiltration, precipitation, and tangential flow filtration (TFF) have been utilized for EV isolation. Although isolated EVs have their own functionalities, several researchers are trying to functionalize EVs by applying various engineering approaches. Gene editing, exogenous, endogenous, and hybridization methods are the four well-known types of EV functionalization strategies. EV engineered through these processes has been applied in the field of regenerative medicine, including kidney diseases, osteoarthritis, rheumatoid arthritis, nervous system-related diseases, and others. In this review, it was focused on engineering approaches for EV functionalization and their applications in regenerative medicine.

Current Immunotherapy Strategies for Rheumatoid Arthritis: The Immunoengineering and Delivery Systems

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease accompanied by persistent multiarticular synovitis and cartilage degradation. The present clinical treatments are limited to disease-modifying anti-rheumatic drugs (DMARDs) and aims to relieve pain and control the inflammation of RA. Despite considerable advances in the research of RA, the employment of current clinical procedure is enormous, hindered by systemic side effect, frequent administration, tolerance from long-lasting administration, and high costs. Emerging immunoengineering-based strategies, such as multiple immune-active nanotechnologies via mechanism-based immunology approaches, have been developed to improve specific targeting and to reduce adverse reactions for RA treatments. Here, we review recent studies in immunoengineering for the treatment of RA. The prospect of future immunoengineering treatment for RA has also been discussed.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment

BACKGROUND

Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy.

MAIN BODY

Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges.

CONCLUSION

This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

The impact of exosomes derived from distinct sources on rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that can induce joint deformities and functional impairment, significantly impacting the overall well-being of individuals. Exosomes, which are cellularly secreted vesicles, possess favorable biological traits such as biocompatibility, stability, and minimal toxicity. Additionally, they contain nucleic acids, lipids, proteins, amino acids, and metabolites, serving as mediators in cellular communication and information exchange. Recent studies have demonstrated the association between exosomes and the pathogenesis of RA. Exosomes derived from mesenchymal stem cells, dendritic cells, and neutrophils exert influence on the biological functions of immune cells and joint cells, however, the precise mechanism remains largely unclarified. This comprehensive review systematically analyzes and summarizes the biological characteristics and functionalities of exosomes derived from diverse cellular sources, thus establishing a scientific foundation for the utilization of exosomes as diagnostic targets and therapeutic modalities in the context of RA.

Research progress of exosomes as drug carriers in cancer and inflammation

Extracellular vesicles (EVs) could be produced by most cells and play an important role in disease development. As a subtype of EVs, exosomes exhibit suitable size, rich surface markers and diverse contents, making them more appealing as potential drug carriers. Compared with traditional synthetic nanoparticles, exosomes possess superior biocompatibility and much lower immunogenicity. This work reviewed the most up-to-date research progress of exosomes as carriers for nucleic acids, proteins and small molecule drugs for cancer and inflammation management. The drug loading strategies and potential cellular uptake behaviour of exosomes are highlighted, trying to provide reference for future exosome design and application.

The Negative Impact of Triptolide on the Immune Function of Human Natural Killer Cells

Triptolide (TP), a bioactive compound extracted the from traditional Chinese medicine Tripterygium wilfordii Hook F (TwHF), has been shown to be effective in treating several autoimmune diseases, and has suppressive effects in several key immune cells such as dendritic cells, T cells, and macrophages. However, it is unknown whether TP has an impact on natural killer (NK) cells. Here, we report that TP has suppressive effects on human NK cell activity and effector functions. The suppressive effects were observed in human peripheral blood mononuclear cell cultures and purified NK cells from healthy donors, as well as in purified NK cells from patients with rheumatoid arthritis. TP treatment induced downregulation of NK-activating receptor (CD54, CD69) expression and IFN-gamma secretion, in a dose-dependent manner. When exposed to K562 target cells, TP treatment induced inhibition of surface expression of CD107a and IFN-gamma synthesis in NK cells. Furthermore, TP treatment induced activation of inhibitory signaling (SHIP, JNK) and inhibition of MAPK signaling (p38). Thus, our findings demonstrate a previously unknown role for TP in NK cell functional suppression and reveal several key intracellular signaling that can be regulated by TP. Our findings also offer new insight into mechanisms of TP therapeutic treatment in autoimmune disease.