[Exosome and prevention of Alzheimer's disease: based on theory of kidney storing essence].

The theory of kidney storing essence storage, an important part of the basic theory of traditional Chinese medicine(TCM), comes from the Chapter 9 Discussion on Six-Plus-Six System and the Manifestations of the Viscera in the Plain Questions, which says that "the kidney manages closure and is the root of storage and the house of Jing(Essence)". According to this theory, essence is the fundamental substance of human life activities and it is closely related to the growth and development of the human body. Alzheimer's disease(AD) is one of the common neurodegenerative diseases, with the main pathological features of Aß deposition and Tau phosphorylation, which activate neurotoxic reactions and eventually lead to neuronal dysfunction and cell death, severely impairing the patient's cognitive and memory functions. Although research results have been achieved in the TCM treatment of AD, the complex pathogenesis of AD makes it difficult to develop the drugs capable of curing AD. The stem cell therapy is an important method to promote self-repair and regeneration, and bone marrow mesenchymal stem cells(BMSCs) as adult stem cells have the ability of multi-directional differentiation. By reviewing the relevant literature, this paper discusses the association between BMSCs and the TCM theory of kidney storing essence, and expounds the material basis of this theory from the perspective of molecular biology. Studies have shown that TCM with the effect of tonifying the kidney in the treatment of AD are associated with BMSCs. Exosomes produced by such cells are one of the main substances affecting AD. Exosomes containing nucleic acids, proteins, and lipids can participate in intercellular communication, regulate cell function, and affect AD by reducing Aß deposition, inhibiting Tau protein phosphorylation and neuroinflammation, and promoting neuronal regeneration. Therefore, discussing the prevention and treatment of exosomes and AD based on the theory of kidney storing essence will provide a new research idea for the TCM treatment of AD.

IL-27-induced, MSC-derived Exosomes Promote MMP3 Expression Through the miR-206/L3MBTL4 Axis in Synovial Fibroblasts.

Context: In rheumatoid arthritis (RA), hyperproliferative fibroblast-like synoviocytes (FLS) can secrete a variety of tissue hydrolases, such as matrix metalloproteinases (MMPs), causing the destruction of chondrocytes. Mesenchymal stem cells (MSCs) can directly affect FLS through extracellular vesicles (EVs). Interleukin-27 (IL-27) is a pleiotropic immune regulator frequently overexpressed in RA. Objective: The study intended to examine the effects of IL-27-induced exosomes from bone-marrow mesenchymal stem cells (BM-MSCs) and to determine if they promote the secretion of MMP3 in synovial cells. Design: The research team performed a genetic study. Setting: The study took place at the First Affiliated Hospital of Hainan Medical University in Haikou City, Hainan, China. Outcome Measures: The research team: (1) determined if IL-27 expression had occurred in the synovial fluid; (2) co-cultured IL-27-induced MSCs with FLS to detect the expression of MMP3 in the FLS; (3) Under IL-27 induction, MSC-derived exosomes with IL-27R knockdown were collected to detect the expression of microRNAs(miRNAs) associated with RA; (4) screened the miRNAs to determine the most significant differences in expression; (5) determined the miRNA target genes in arthritis, using Western blot (WB) and qRT-PCR; and (6) Dual luciferase and ChIP experiments confirm regulation of MMP3 by L3MBTL4. Results: IL-27 was highly expressed in RA, and the IL-27-induced, MSC-derived exosomes promoted the expression of MMP3 in FLS. The IL-27-induced MSC-derived exosomes significantly upregulated the expression of miR-206-3p, and the miR-206-3p target, miR-206/ lethal(3) malignant brain tumor-like protein 4 (L3MBTL4), regulated the MMP3 transcription. The IL-27-induced, MSC-derived exosomes promoted MMP3 expression in the FLS through the miR-206-3p/L3MBTL4 axis, thereby promoting chondrocyte degradation and aggravating RA. Conclusions: IL-27 can induce the expression of miR-206 in MSCs, and miR-206 can be transported into FLS through MSC-EVs to promote FLS migration and MMP3 expression and aggravate articular cartilage damage. Patients with RA who have a high IL-27 expression may not be suitable to receive treatment with MSCs, and clinicians can use MSCs that knock down or delete IL-27R to treat RA patients who have a high IL-27 expression.

Targeting tumor-derived exosome-mediated premetastatic niche formation: The metastasis-preventive value of traditional Chinese medicine.

Tumor-derived exosome (TDE)-mediated premetastatic niche (PMN) formation is a potential mechanism underlying the organotropic metastasis of primary tumors. Traditional Chinese medicine (TCM) has shown considerable success in preventing and treating tumor metastasis. However, the underlying mechanisms remain elusive. In this review, we discussed PMN formation from the perspectives of TDE biogenesis, cargo sorting, and TDE recipient cell alterations, which are critical for metastatic outgrowth. We also reviewed the metastasis-preventive effects of TCM, which act by targeting the physicochemical materials and functional mediators of TDE biogenesis, regulating the cargo sorting machinery and secretory molecules in TDEs, and targeting the TDE-recipient cells involved in PMN formation.

Triptolide improves chondrocyte proliferation and secretion via down-regulation of miR-221 in synovial cell exosomes.

BACKGROUND: Rheumatoid arthritis (RA), the most common type of inflammatory arthritis, can cause bone damage and disability. Triptolide, a prominent treatment for RA, has satisfactory anti-inflammatory effects. However, the mechanism of action of triptolide in RA remains unknown. PURPOSE: This study aimed to explore the molecular mechanisms underlying triptolide-mediated improvements in RA and identify the miRNA pathway responsible for these effects. METHODS: We identified various dysregulated miRNAs associated with RA by mining previously described microarray data and verified and screened these candidates using RT-qPCR. Hematoxylin-eosin staining was then applied to identify pathological changes in the affected joints, and cell counting kit-8 analysis and flow cytometry were employed to examine cell proliferation and apoptosis, respectively. Extracted exosomes were verified using transmission electron microscopy. RESULTS: Our results revealed that the legs of rats with collagen-induced arthritis presented with obvious swelling and bone damage, a high degree of inflammatory cell infiltration into the synovium, and structural changes to the cartilage. Data mining identified 39 dysregulated miRNAs in these tissues, and RT-qPCR further refined these observations to highlight miR-221 as a potential RA biomarker. Subsequent evaluations revealed that fibroblast-like synovial (FLS) cells secrete Exs carrying dysregulated miR-221 in vitro. These Exs mediate miR-221 levels, inflammation, and TLR4/MyD88 signaling via their fusion with chondrocytes, leading to changes in chondrocyte growth and metabolic factor levels. Additionally, the addition of triptolide impaired miR-221 expression, cell proliferation, inflammatory factors, and the protein levels of TLR4/MyD88 in RA-FLS and promoted the apoptosis of FLS. The therapeutic effect of triptolide on miR-221 Exs was reversed by miR-221 inhibitor in both normal and RA FLS. CONCLUSION: Our research shows that effective treatment with triptolide is mediated by its regulation of growth and secretory functions of chondrocytes via the inhibition of miR-221 secretion by FLS, providing a new target and natural medicinal candidate for future RA treatments.

Effect of modified Jianpi Yangzheng on regulating content of PKM2 in gastric cancer cells-derived exosomes.

BACKGROUND: Modified Jianpi Yangzheng decoction (mJPYZ), as an empirical decoction of Traditional Chinese medicine has been shown significantly to prolong the survival of patients with advanced stage gastric cancer. Pyruvate kinase M2 (PKM2), has attracted attention for its important role on cellular aerobic glycolysis, however, few studies focus on PKM2 non-metabolic roles in tumor progression. PURPOSE: Our study aimed to investigate the potential role of gastric cancer exosomes containing PKM2 in regulating tumor-associated macrophages (TAM) and the mechanism of mJPYZ against gastric cancer. METHODS: Colony Formation Assay, flow cytometry and TUNEL staining were employed to estimate the effect of mJPYZ on gastric cancer in tumor-bearing mice and cells. Western blot analyzed apoptosis-related protein expression changes. Network pharmacology and bioinformatics predicted potential exosomes modulation of mJPYZ in gastric cancer. Exosomes were isolated and co-cultured with TAM. Diff-Quik Staining observed the TAM morphological changes when incubating with gastric cancer cells exosomes. Flow cytometry and immunofluorescence were performed to demonstrate whether exosomes PKM2 involved in TAM polarization. RESULTS: mJPYZ induced apoptosis of gastric cancer cells by targeting PKM2 and downregulating PI3K/Akt/mTOR axis in vivo and in vitro. Network pharmacology showed potential exosomes modulation of mJPYZ in gastric cancer. We extracted exosomes and found mJPYZ decreased the abundance of serum exosomes PKM2 in patients with advanced gastric cancer and xenograft tumor model. Additionally, we firstly detected and confirmed that PKM2 is a package protein of exosomes extracted from gastric cancer cells, and mJPYZ could diminish the content of exosomal PKM2 in gastric cancer cells. Importantly, mJPYZ reduced the delivery of exosomal PKM2 from tumor cells to macrophages, and alleviated exosomal PKM2-induced differentiation of M2-TAM in tumor microenvironment, eventually inhibited gastric cancer progression. CONCLUSION: Gastric cancer exosomes containing PKM2 could lead to M2 macrophages differentiation, thereby promoting gastric cancer progression. Our findings provide a rationale for potential application of mJPYZ in the treatment of gastric cancer via PKM2.

Hyperthermia promotes exosome secretion by regulating Rab7b while increasing drug sensitivity in adriamycin-resistant breast cancer.

PURPOSE: To investigate the mechanism through which hyperthermia promotes exosome secretion and drug sensitivity in adriamycin-resistant breast cancer. MATERIALS AND METHODS: We first evaluated the effect of hyperthermia on adriamycin-resistant breast cancer viability and used transmission electron microscopy, nanoparticle tracking analysis, and a bicinchoninic acid kit to validate the effect of hyperthermia on exosome secretion. The effective targeting molecules and pathways changed by hyperthermia were explored by RNA microarray and verified in vitro. The adriamycin-resistant MCF-7/ADR cells co-incubated with the exosomes produced by MCF-7/ADR cells after hyperthermia were assessed. The uptake of exosomes by MCF-7/ADR cells after hyperthermia treatment was evaluated by confocal microscopy. Finally, the mechanism through which hyperthermia promotes exosome secretion by hyperthermia was determined. RESULTS: Hyperthermia significantly suppressed the growth of adriamycin-resistant breast cancer cells and increased drug sensitivity by upregulating FOS and CREB5, genes related to longer overall survival in breast cancer patients. Moreover, hyperthermia promoted exosome secretion through Rab7b, a small GTPase that controls endosome transport. The upregulated FOS and CREB5 antioncogenes can be transferred to MCF-7/ADR cells by hyperthermia-treated MCF-7/ADR cell-secreted exosomes. CONCLUSIONS: Our results demonstrated a novel function of hyperthermia in promoting exosome secretion in adriamycin-resistant breast cancer cells and revealed the effects of hyperthermia on tumor cell biology. These hyperthermia-triggered exosomes can carry antitumor genes to the residual tumor and tumor microenvironment, which may be more beneficial to the effects of hyperthermia. These results represent an exploration of the relationship between therapeutic strategies and exosome biology.

Hippo pathway: Regulation, deregulation and potential therapeutic targets in cancer.

Hippo pathway is a master regulator of development, cell proliferation, stem cell function, tissue regeneration, homeostasis, and organ size control. Hippo pathway relays signals from different extracellular and intracellular events to regulate cell behavior and functions. Hippo pathway is conserved from Protista to eukaryotes. Deregulation of the Hippo pathway is associated with numerous cancers. Alteration of the Hippo pathway results in cell invasion, migration, disease progression, and therapy resistance in cancers. However, the function of the various components of the mammalian Hippo pathway is yet to be elucidated in detail especially concerning tumor biology. In the present review, we focused on the Hippo pathway in different model organisms, its regulation and deregulation, and possible therapeutic targets for cancer treatment.

Lysyl Oxidase-Like 4 Fosters an Immunosuppressive Microenvironment During Hepatocarcinogenesis.

BACKGROUND AND AIMS: Lysyl oxidase-like 4 (LOXL4) is an amine oxidase that is primarily involved in extracellular matrix remodeling and is highly expressed in HCC tissues, but its functional role in mediating liver carcinogenesis is poorly understood. Therefore, we aimed to investigate the role of LOXL4 in hepatocarcinogenesis. APPROACH AND RESULTS: Here, we demonstrate that hepatic LOXL4 expression was increased during the liver carcinogenesis in mice concomitantly fed a choline-deficient, l-amino acid-defined diet. LOXL4 was secreted by the neoplastic cells and primarily localized within hepatic macrophages through exosome internalization. Supplementation of LOXL4 had minimal effect on neoplastic cells. In vitro exposure of macrophages to LOXL4 invoked an immunosuppressive phenotype and activated programmed death ligand 1 (PD-L1) expression, which further suppressed the function of CD8+ T cells. Injection of LOXL4 promoted macrophages infiltration into the liver and accelerated tumor growth, which was further abolished by adoptive T-cell transfer or PD-L1 neutralization. Label-free proteomics analysis revealed that the immunosuppressive function of LOXL4 on macrophages primarily relied on interferon (IFN)-mediated signal transducer and activator of transcription-dependent PD-L1 activation. Hydrogen peroxide scavenger or copper chelation on macrophages abolished the IFN-mediated PD-L1 presentation by LOXL4. In human HCC tissue, expression of LOXL4 in CD68+ cells was positively correlated with PD-L1 level. High expression of LOXL4 in CD68+ cells and low expression of CD8A in tumor tissue cooperatively predict poor survival of patients with HCC. CONCLUSIONS: LOXL4 facilitates immune evasion by tumor cells and leads to hepatocarcinogenesis. Our study unveils the role of LOXL4 in fostering an immunosuppressive microenvironment during hepatocarcinogenesis.

Ovatodiolide, isolated from Anisomeles indica, suppresses bladder carcinogenesis through suppression of mTOR/ß-catenin/CDK6 and exosomal miR-21 derived from M2 tumor-associated macrophages.

Bladder cancer (BCa) is the fourth leading cause of cancer deaths worldwide due to its aggressiveness and resistance against therapies. Intricate interactions between cancer cells and the tumor microenvironment (TME) are essential for both disease progression and regression. Thus, interrupting molecular communications within the TME could potentially provide improved therapeutic efficacies. M2-polarized tumor-associated macrophages (M2 TAMs) were shown to contribute to BCa progression and drug resistance. We attempted to provide evidence for ovatodiolide (OV) as a potential therapeutic agent that targets both TME and BCa cells. First, tumor-suppressing functions of OV were determined by cell viability, colony, and tumor-sphere formation assays using a coculture system composed of M2 TAMs/BCa cells. Subsequently, we demonstrated that extracellular vesicles (EVs) isolated from M2 TAMs containing oncomiR-21 and mRNAs, including Akt, STAT3, mTOR, and ß-catenin, promoted cisplatin (CDDP) resistance, migration, and tumor-sphere generation in BCa cells, through increasing CDK6, mTOR, STAT3, and ß-catenin expression. OV treatment also prevented M2 polarization and reduced EV cargos from M2 TAMs. Finally, in vivo data demonstrated that OV treatment overcame CDDP resistance. OV only and the OV + CDDP combination both resulted in significant reductions in mTOR, ß-catenin, CDK6, and miR-21 expression in tumor samples and EVs isolated from serum. Collectively, we demonstrated that M2 TAMs induced malignant properties in BCa cells, in part via oncogenic EVs. OV treatment prevented M2 TAM polarization, reduced EV cargos derived from M2 TAMs, and suppressed ß-catenin/mTOR/CDK6 signaling. These findings provide preclinical evidence for OV as a single or adjuvant agent for treating drug-resistant BCa.

Electrical stimulation enhances neuronal cell activity mediated by Schwann cell derived exosomes.

Electrical stimulation (ES) therapy has good effects in patients with nervous system injury-related diseases. ES promotes nerve cell regeneration and stimulates Schwann cells to express neurotrophic factors. The incidence of stress urinary incontinence (SUI) among elderly people is increasing. Some studies suggest that damage to the pudendal nerve is closely related to the pathogenesis of SUI. It has also been found that pelvic ES can reduce SUI symptoms in a rat model of SUI caused by pudendal nerve injury. Clinically, pelvic floor electrical stimulation is effective in patients with mild to moderate SUI. These studies indicate that ES may ameliorate damage to the pudendal nerve and thus achieve the goal of SUI treatment, although the mechanism of action of this treatment remains unclear. Therefore, the purpose of the present study was to clarify the relationships among ES, neural cells and Schwann cells at the cellular level. We applied ES to nerve cells at 100 mV/mm or 200 mV/mm for 0, 0.5, 1, or 2 h to investigate changes in nerve cell activity. We then co-cultured the nerve cells with Schwann cells to explore the influence of single-culture and co-culture conditions on the nerve cells. Compared to non-ES, ES of the nerve cells increased their activity. Compared to those in single culture, co-cultured nerve cells exhibited an additional increase in activity. We also found that Schwann cell derived exosomes could promote the activity of nerve cells, with glutamate and calcium ions playing a potential role in this process. These results suggest that the mutual regulation of neural cells and Schwann cells plays an important role in the process by which ES ameliorates neurological function, which may provide a basis for subsequent studies.

Exosomes in cancer development and clinical applications.

Exosomes participate in cancer progression and metastasis by transferring bioactive molecules between cancer and various cells in the local and distant microenvironments. Such intercellular cross-talk results in changes in multiple cellular and biological functions in recipient cells. Several hallmarks of cancer have reportedly been impacted by this exosome-mediated cell-to-cell communication, including modulating immune responses, reprogramming stromal cells, remodeling the architecture of the extracellular matrix, or even endowing cancer cells with characteristics of drug resistance. Selectively, loading specific oncogenic molecules into exosomes highlights exosomes as potential diagnostic biomarkers as well as therapeutic targets. In addition, exosome-based drug delivery strategies in preclinical and clinical trials have been shown to dramatically decrease cancer development. In the present review, we summarize the significant aspects of exosomes in cancer development that can provide novel strategies for potential clinical applications.

Exosomes from heat-stressed tumour cells inhibit tumour growth by converting regulatory T cells to Th17 cells via IL-6.

Exosomes derived from heat-stressed tumour cells (HS-TEXs), which contain abundant heat shock protein (HSP) 70, strongly induce antitumour immune responses. HSP70-induced interleukin (IL)-6 promotes IL-17 expression and causes rejection of established prostate tumours. However, it remains unclear whether HS-TEXs exhibit antitumour effects by converting regulatory T cells (Tregs ) into T helper type 17 (Th17) cells. In this study, we found that compared with TEXs, HS-TEXs were more potent in stimulating secretion of IL-6 from dendritic cells. In vitro, IL-6 blocked tumour cell-derived transforming growth factor beta 1-induced Treg differentiation and promoted Th17 cell differentiation. HS-TEXs exerted strong antitumour effects, converting Tregs into Th17 cells with high efficiency, a process that was entirely dependent upon IL-6. Neutralization of IL-17 completely abolished the antitumour effect of TEXs, but only partially inhibited that of HS-TEXs. In addition, we found higher levels of IL-6 and IL-17 in serum from tumour patients treated with hyperthermia, and an increase in Th17 cells and a decrease in Tregs was detected in peripheral blood mononuclear cells isolated from these patients after hyperthermia. Therefore, our results demonstrate that HS-TEXs possess a powerful capacity to convert immunosuppressive Tregs into Th17 cells via IL-6, which contributes to their potent antitumour effect.

Generation of Infectious Prions and Detection with the Prion-Infected Cell Assay.

Cell lines propagating prions are an efficient and useful means for studying the cellular and molecular mechanisms implicated in prion disease. Utilization of cell-based models has led to the finding that PrPC and PrPSc are released from cells in association with extracellular vesicles known as exosomes. Exosomes have been shown to act as vehicles for infectivity, transferring infectivity between cell lines and providing a mechanism for prion spread between tissues. Here, we describe the methods for generating a prion-propagating cell line with prion-infected brain homogenate, cell lysate, conditioned media, and exosomes and also detection of protease-resistant PrP with the prion-infected cell assay.

Mutant copper-zinc superoxide dismutase (SOD1) induces protein secretion pathway alterations and exosome release in astrocytes: implications for disease spreading and motor neuron pathology in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is the most common motor neuron disease and is still incurable. The mechanisms leading to the selective motor neuron vulnerability are still not known. The interplay between motor neurons and astrocytes is crucial in the outcome of the disease. We show that mutant copper-zinc superoxide dismutase (SOD1) overexpression in primary astrocyte cultures is associated with decreased levels of proteins involved in secretory pathways. This is linked to a general reduction of total secreted proteins, except for specific enrichment in a number of proteins in the media, such as mutant SOD1 and valosin-containing protein (VCP)/p97. Because there was also an increase in exosome release, we can deduce that astrocytes expressing mutant SOD1 activate unconventional secretory pathways, possibly as a protective mechanism. This may help limit the formation of intracellular aggregates and overcome mutant SOD1 toxicity. We also found that astrocyte-derived exosomes efficiently transfer mutant SOD1 to spinal neurons and induce selective motor neuron death. We conclude that the expression of mutant SOD1 has a substantial impact on astrocyte protein secretion pathways, contributing to motor neuron pathology and disease spread.