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Intestinal farnesoid X receptor (FXR) plays a critical role in alcohol-associated liver disease (ALD). We aimed to investigate whether alcohol-induced dysbiosis increased intestinal microRNA194 (miR194) that suppressed Fxr transcription and whether Lactobacillus rhamnosus GG-derived exosome-like nanoparticles (LDNPs) protected against ALD through regulation of intestinal miR194-FXR signaling in mice.Binge-on-chronic alcohol exposure mouse model was utilized. In addition to the decreased ligand-mediated FXR activation, alcohol feeding repressed intestinal Fxr transcription and increased miR194 expression. This transcriptional suppression of Fxr by miR194 was confirmed in intestinal epithelial Caco-2 cells and mouse enteriods. The alcohol feeding-reduced intestinal FXR activation was further demonstrated by the reduced FXR reporter activity in fecal samples and by the decreased fibroblast growth factor 15 (Fgf15) messenger RNA (mRNA) in intestine and protein levels in the serum, which caused an increased hepatic bile acid synthesis and lipogeneses. We further demonstrated that alcohol feeding increased-miR194 expression was mediated by taurine-upregulated gene 1 (Tug1) through gut microbiota regulation of taurine metabolism. Importantly, 3-day oral administration of LDNPs increased bile salt hydrolase (BSH)-harboring bacteria that decreased conjugated bile acids and increased gut taurine concentration, which upregulated Tug1, leading to a suppression of intestinal miR194 expression and recovery of FXR activation. Activated FXR upregulated FGF15 signaling and subsequently reduced hepatic bile acid synthesis and lipogenesis and attenuated ALD. These protective effects of LDNPs were eliminated in intestinal FxrOur results demonstrated that gut microbiota-mediated miR194 regulation contributes to ALD pathogenesis and to the protective effects of LDNPs through modulating intestinal FXR signaling.

PDF file - 27K, Figure S4. Activation of Mekk2/Erk5 pathway is required for tumor cells to escape NK cell-mediated immunosurveillance.

PDF file - 36K, Figure S1: Generation and characterization of monoclonal cell lines with different expression levels of miR-17~92 cluster miRNAs.

Aberrant microRNA (miRNA) expression has been identified in various human solid cancers. However, whether the levels of miRNA expression in tumor cells have any effect on tumor progression has not been determined. In this proof-of-concept study, the restoration of high-level expression of the miR17–92 cluster of miRNAs reveals its function as a tumor suppressor in murine solid cancer cells. Specifically, genetically engineered expression of higher levels of miR17/20a in the miR17–92 cluster in both murine breast cancer and colon cancer cells triggered natural killer (NK)–cell recognition by inhibiting the expression of MHC class I (H-2D) through the Mekk2–Mek5–Erk5 pathway. Results from the mouse tumor studies were recapitulated using samples of human solid tumors. Together, these data indicate that miR17/20a miRNAs function as tumor suppressors by reprogramming tumor cells for NK cell-mediated cytotoxicity. Cancer Immunol Res; 2(8); 789–99. ©2014 AACR.

PDF file - 27K, Figure S2. Reduction of MHC class I expression on tumor cells elicited by miR-17/20a.

PDF file - 23K, Figure S3. Map3k2 is a direct target of miR-17/20a as predicted by public algorithms.

PDF file - 194K

Prenatal ethanol exposure can impair neural crest cell (NCC) development, including NCC survival, differentiation and migration, contributing to the craniofacial dysmorphology in Fetal Alcohol Spectrum Disorders (FASD). Epithelial-mesenchymal transition (EMT) plays an important role in regulating the migration of NCCs. The objective of this study is to determine whether ethanol exposure can suppress NCC migration through inhibiting EMT and whether microRNA-34a (miR-34a) is involved in the ethanol-induced impairment of EMT in NCCs. We found that exposure to 100 mM ethanol significantly inhibited the migration of NCCs. qRT-PCR and Western Blot analysis revealed that exposure to ethanol robustly reduced the mRNA and protein expression of Snail1, a critical transcriptional factor that has a pivotal role in the regulation of EMT. Ethanol exposure also significantly increased the mRNA expression of the Snail1 target gene E-cadherin1 and inhibited EMT in NCCs. We also found that exposure to ethanol significantly elevated the expression of miR-34a that targets Snail1 in NCCs. In addition, down-regulation of miR-34a prevented ethanol-induced repression of Snail1 and diminished ethanol-induced upregulation of Snail1 target gene E-cadherin1 in NCCs. Inhibition of miR-34a restored EMT and prevented ethanol-induced inhibition of NCC migration in vitro and in zebrafish embryos in vivo. These results demonstrate that ethanol-induced upregulation of miR-34a contributes to the impairment of NCC migration through suppressing EMT by targeting Snail1.

Supplemental Methods and References. Description of additional methods and procedures used in the study. Also includes Supplemental References.

Supplemental Tables S1-S4. Characteristics of 20 colon cancer patients (S1); Characteristics of 21 breast cancer patients (S2); IHC scores of chemokines (CXCL1, CXCL10, CCL2 and CCL5) in human colon cancer tissues (S3); IHC scores of chemokines (CXCL1, CXCL10, CCL2 and CCL5) in human breast cancer tissues (S4).

Supplemental Figures S1-S9. Chemokine receptors expressed on PMA stimulated EL4 cells (S1); Uptake of GNVs membrane derived vesicles and stability of IGNVs (S2); Transmigration of GNVs and IGNVs (S3); Expression of integrins on EL4 cells and LFA-1 on IGNVs (S4); Purification of plasma membrane from leukocytes and chemokines in the culture medium of human SW620 cells (S5); Effects of IGNVs on cell proliferation in vitro and potential toxicity in vivo (S6); Therapeutic drug-loaded IGNVs and Characterization of DOX-NPTM and control liposomes from Avanti (S7); Biodistribution of DOX in 4T1 tumor tissues and therapeutic effect of IGNV-Cur on the inhibition of DSS-induced mouse colitis (S8); Determination of critical GNV miceller concentration (S9).

Lung inflammation is a hallmark of coronavirus disease 2019 (COVID-19). In this study, we show that mice develop inflamed lung tissue after being administered exosomes released from the lung epithelial cells exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Nsp12 and Nsp13 (exosomesNsp12Nsp13). Mechanistically, we show that exosomesNsp12Nsp13 are taken up by lung macrophages, leading to activation of nuclear factor κB (NF-κB) and the subsequent induction of an array of inflammatory cytokines. Induction of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β from exosomesNsp12Nsp13-activated lung macrophages contributes to inducing apoptosis in lung epithelial cells. Induction of exosomesNsp12Nsp13-mediated lung inflammation was abolished with ginger exosome-like nanoparticle (GELN) microRNA (miRNA aly-miR396a-5p. The role of GELNs in inhibition of the SARS-CoV-2-induced cytopathic effect (CPE) was further demonstrated via GELN aly-miR396a-5p- and rlcv-miR-rL1-28-3p-mediated inhibition of expression of Nsp12 and spike genes, respectively. Taken together, our results reveal exosomesNsp12Nsp13 as potentially important contributors to the development of lung inflammation, and GELNs are a potential therapeutic agent to treat COVID-19., Graphical Abstract, COVID-19 is a disease affecting the pulmonary system with devastating inflammation. Teng et al. have shown that exosomes released from SARS-CoV-2-infected lung epithelia cells are preferentially taken up by lung macrophages that subsequently induce lung inflammation. Ginger exosome-like nanoparticle miRNA inhibits SARS-CoV-2-induced lung inflammation and viral replication.

To effectively prevent and control the spontaneous combustion of residual coal at the bottom of a large fully mechanized gob space, we proposed a targeted inertization technology based on the injection of power plant flue gas. Based on the real onsite conditions of the gob, the three‐dimensional distributions of the overburden fractures, gas emission, and residual coal were added to the multiphysics coupled model of spontaneous coal combustion. The simulation method based on moving coordinates was used to complete the risk evaluation and the locating of the spontaneous combustion in the fully mechanized gob, and the key control factors of the inerted zone and the fire prevention effect of the flue gas injection were analyzed. The results showed that the mismatch between the inerted zone and the spontaneous combustion risk zone was the root cause of the poor fire prevention effect of the inert gas injection. Because the density of the flue gas was greater than that of the leaked air, the flue gas mainly migrated and diffused in the lower part of the gob. At a distance of 100 m from the working face, the flue gas with 3%‐9% oxygen content injected at a rate of 2000 m3/h completely covered the high‐temperature residual coal. This caused the maximum temperature (Tmax) to drop from 334.2 K upon nitrogen injection to below 310 K. Additionally, the effect of the oxygen content fluctuation on Tmax was controlled within 2.6 K. The methods and the results in this study can serve as a reference for efficiently preventing and controlling local spontaneous combustion hazards in large spaces for underground coal mining.

Macrophages have been linked to tumor initiation, progression, metastasis, and treatment resistance. However, the transcriptional regulation of macrophages driving the protumor function remains elusive. Here, we demonstrate that the transcription factor c-Maf is a critical controller for immunosuppressive macrophage polarization and function in cancer. c-Maf controls many M2-related genes and has direct binding sites within a conserved noncoding sequence of the Csf-1r gene and promotes M2-like macrophage–mediated T cell suppression and tumor progression. c-Maf also serves as a metabolic checkpoint regulating the TCA cycle and UDP-GlcNAc biosynthesis, thus promoting M2-like macrophage polarization and activation. Additionally, c-Maf is highly expressed in tumor-associated macrophages (TAMs) and regulates TAM immunosuppressive function. Deletion of c-Maf specifically in myeloid cells results in reduced tumor burden with enhanced antitumor T cell immunity. Inhibition of c-Maf partly overcomes resistance to anti–PD-1 therapy in a subcutaneous LLC tumor model. Similarly, c-Maf is expressed in human M2 and tumor-infiltrating macrophages/monocytes as well as circulating monocytes of human non–small cell lung carcinoma (NSCLC) patients and critically regulates their immunosuppressive activity. The natural compound β-glucan downregulates c-Maf expression on macrophages, leading to enhanced antitumor immunity in mice. These findings establish a paradigm for immunosuppressive macrophage polarization and transcriptional regulation by c-Maf and suggest that c-Maf is a potential target for effective tumor immunotherapy.

Metastasis is the leading cause of cancer-related deaths and myeloid cells are critical in the metastatic microenvironment. Here, we explore the implications of reprogramming pre-metastatic niche myeloid cells by inducing trained immunity with whole beta-glucan particle (WGP). WGP-trained macrophages had increased responsiveness not only to lipopolysaccharide but also to tumor-derived factors. WGP in vivo treatment led to a trained immunity phenotype in lung interstitial macrophages, resulting in inhibition of tumor metastasis and survival prolongation in multiple mouse models of metastasis. WGP-induced trained immunity is mediated by the metabolite sphingosine-1-phosphate. Adoptive transfer of WGP-trained bone marrow-derived macrophages reduced tumor lung metastasis. Blockade of sphingosine-1-phosphate synthesis and mitochondrial fission abrogated WGP-induced trained immunity and its inhibition of lung metastases. WGP also induced trained immunity in human monocytes, resulting in antitumor activity. Our study identifies the metabolic sphingolipid-mitochondrial fission pathway for WGP-induced trained immunity and control over metastasis.

Clathrate hydride \emph{Fm}\={3}\emph{m}-LaH$_{10}$ has been proven as the most extraordinary superconductor with the critical temperature $T_c$ above 250 K upon compression of hundreds of GPa in recent years. A general hope is to reduce the stabilization pressure and maintain the high $T_c$ value of the specific phase in LaH$_{10}$. However, strong structural instability distorts \emph{Fm}\={3}\emph{m} structure and leads to a rapid decrease of $T_c$ at low pressures. Here, we investigate the phase stability and superconducting behaviors of \emph{Fm}\={3}\emph{m}-LaH$_{10}$ with enhanced chemical pre-compression through partly replacing La by Ce atoms from both experiments and calculations. For explicitly characterizing the synthesized hydride, we choose lanthanum-cerium alloy with stoichiometry composition of 1:1. X-ray diffraction and Raman scattering measurements reveal the stabilization of \emph{Fm}\={3}\emph{m}-La$_{0.5}$Ce$_{0.5}$H$_{10}$ in the pressure range of 140-160 GPa. Superconductivity with $T_c$ of 175$\pm$2 K at 155 GPa is confirmed with the observation of the zero-resistivity state and supported by the theoretical calculations. These findings provide applicability in the future explorations for a large variety of hydrogen-rich hydrides., Comment: 6 pages, 5 figures

Inspired by the high critical temperature in yttrium superhydride and the low stabilized pressure in superconducting cerium superhydride, we carry out four independent runs to synthesize yttrium-cerium alloy hydrides. The phases examined by the Raman scattering and x-ray diffraction measurements. The superconductivity is detected with the zero-resistance state at the critical temperature in the range of 97-140 K at pressures ranging from 114 GPa to 120$\pm$4 GPa. The maximum critical temperature of the synthesized hydrides is larger than those reported for cerium hydrides, while the corresponding stabilized pressure is much lower than those for superconducting yttrium hydrides. The structural analysis and theoretical calculations suggest that the phase of Y$_{0.5}$Ce$_{0.5}$H$_9$ has the space group $P6_3/mmc$ with the calculated critical temperature of 119 K, in fair agreement with the experiments. These results indicate that alloying superhydrides indeed can maintain relatively high critical temperature at modest pressures accessible by many laboratories., Comment: 6 pages, 6 figures

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. Thus, our findings provide evidence that small molecules released from the gut microbiome can directly bind genomic DNA and act as transcriptional coregulators by recruiting transcription factors. These findings further unveil a molecular mechanism that connects gut metabolism to gene expression in the brain with implications for disease development.

Both host genetics and gut microbiome have important effects on human health, yet how host genetics regulates gut bacteria and further determines disease susceptibility remains unclear. Here, we find that gut microbiome pattern of active tuberculosis (TB) patients is characterized by a reduction of core species found across healthy controls, particularly Akkermansia muciniphila (A. muciniphila). Oral treatments of A. muciniphila or palmitoleic acid, an A. muciniphila-derived metabolite, strongly inhibit TB infection through epigenetically inhibiting TNF-α. We use three independent cohorts comprising 6512 individuals and identify that single-nucleotide polymorphism rs2257167 “G” allele of type I interferon (IFN-I) receptor 1 (Ifnar1) contributes to stronger IFN-I signaling, impaired colonization and abundance of A. muciniphila, reduced production of palmitoleic acid, higher TNF-α, and much severer TB disease in humans and transgenic mice. Thus, host genetics are critical in modulating structure and functions of gut microbiome and gut microbial metabolites, which further determines disease susceptibility.

The IL-1 signaling pathway has been shown to play a critical role in the pathogenesis of chronic, autoinflammatory skin diseases such as psoriasis. However, the exact cellular and molecular mechanisms have not been fully understood. Here, we show that IL-1β is significantly elevated in psoriatic lesional skin and imiquimod-treated mouse skin. In addition, IL-1R signaling appears to correlate with psoriasis disease progression and treatment response. IL-1 signaling in both dermal γδ T cells and other cells such as keratinocytes is essential to an IMQ-induced skin inflammation. IL-1β induces dermal γδ T cell proliferation and IL-17 production in mice. In addition, IL-1β stimulates keratinocytes to secrete chemokines that preferentially chemoattract peripheral CD27– CCR6+IL-17 capable of producing γδ T cells (γδT17). Further studies showed that endogenous IL-1β secretion is regulated by skin commensals to maintain dermal γδT17 homeostasis in mice. Mouse skin associated with Corynebacterium species, bacteria enriched in human psoriatic lesional skin, has increased IL-1β and dermal γδT17 cell expansion. Thus, the IL-1β–IL-1R signaling pathway may contribute to skin inflammation and psoriasis pathogenesis via the direct regulation of dermal IL-17–producing cells and stimulation of keratinocytes for amplifying inflammatory cascade.

The gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders, including obesity, diabetes, and metabolicdysfunction-associated fatty liver disease (MAFLD). However, its underlying mechanism involved in its well-known metabolic actions needs further evaluation. The present study explored the therapeutic effect and mechanism of A. muciniphila in intervening MAFLD by using a high-fat and high-cholesterol (HFC) diet induced obese mice model. Mice treated with A. muciniphila efficiently reversed MAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in the antibiotics-treated obese mice. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress-induced cell apoptosis in gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above and efficiently ameliorated MAFLD. Together, these data indicate that the anti-MAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut–liver interactions through regulating the metabolism of L-aspartate. A. muciniphila could be a potential agent for clinical intervention in MAFLD.

Despite the remarkable success of immunotherapy in many types of cancer, pancreatic ductal adenocarcinoma has yet to benefit. Innate immune cells are critical to anti-tumor immunosurveillance and recent studies have revealed that these populations possess a form of memory, termed trained innate immunity, which occurs through transcriptomic, epigenetic, and metabolic reprograming. Here we demonstrate that yeast-derived particulate β-glucan, an inducer of trained immunity, traffics to the pancreas, which causes a CCR2-dependent influx of monocytes/macrophages to the pancreas that display features of trained immunity. These cells can be activated upon exposure to tumor cells and tumor-derived factors, and show enhanced cytotoxicity against pancreatic tumor cells. In orthotopic models of pancreatic ductal adenocarcinoma, β-glucan treated mice show significantly reduced tumor burden and prolonged survival, which is further enhanced when combined with immunotherapy. These findings characterize the dynamic mechanisms and localization of peripheral trained immunity and identify an application of trained immunity to cancer.

High-fat diet (HFD) decreases insulin sensitivity. How high-fat diet causes insulin resistance is largely unknown. Here, we show that lean mice become insulin resistant after being administered exosomes isolated from the feces of obese mice fed a HFD or from patients with type II diabetes. HFD altered the lipid composition of exosomes from predominantly phosphatidylethanolamine (PE) in exosomes from lean animals (L-Exo) to phosphatidylcholine (PC) in exosomes from obese animals (H-Exo). Mechanistically, we show that intestinal H-Exo is taken up by macrophages and hepatocytes, leading to inhibition of the insulin signaling pathway. Moreover, exosome-derived PC binds to and activates AhR, leading to inhibition of the expression of genes essential for activation of the insulin signaling pathway, including IRS-2, and its downstream genes PI3K and Akt. Together, our results reveal HFD-induced exosomes as potential contributors to the development of insulin resistance. Intestinal exosomes thus have potential as broad therapeutic targets., High-fat diet plays a role in development of insulin resistance. Here, the authors report a mechanism that underlies the development of diet induced insulin resistance through the activation of an aryl hydrocarbon receptor mediated signalling pathway in the liver by faecal exosomes derived from intestinal cells.

Diet influences brain function via inflammatory pathways. However, the molecular mechanisms by which diet intake modulates neuroinflammation are poorly understood. Here we show that garlic exosome-like nanoparticles (GaELNs) inhibited systemic as well as brain inflammatory activity and reverses the insulin resistance in a high-fat diet (HFD) induced mouse obesity model. Oral administration of GaELNs and outer membrane vesicles (OMVs) released from GaELNs manipulated Akkermansia muciniphila are selectively taken up by microglial cells and inhibits its activation. Mechanistically, GaELNphosphatidic acid (PA) (36:4) is required for the uptake of GaELNs via binding microglial brain acid‐soluble protein 1 (BASP1). Formation of the GaELNs/BASP1 complex is required for inhibition of c-Myc mediated expression of STING. Inhibition of STING activity leads to reducing the expression of an array of inflammatory cytokines including IFN-g. IFN-g induces the expression of IDO-1, which in turn IDO-1 mediated metabolites activate the AhR pathway that contributes to insulin resistance. Oral administration of GaELNs decreases the level of IDO-1 metabolites, kynurenine (KYN) which promotes insulin resistance via the AhR pathway in HFD mice. The significance in increased fecal KYN was further demonstrated in the fecal samples of type 2 diabetes patients. Our results further show that the OMVs released from GaELNs treated Akkermansia muciniphila inhibits the expression of microglial IFN-g and prevents KYN mediated IRS-1 and 2 expression in microglial cells. Collectively, these results demonstrate how nanoparticles from a healthy diet can reverse high-fat diet induced brain inflammation and reveal a link between brain microglia/gut microbiota to brain inflammatory disease outcomes via diet-derived exosome-like nanoparticles.

Feedforward CNN models have proven themselves in recent years as state-of-the-art models for predicting single-neuron responses to natural images in early visual cortical neurons. In this paper, we extend these models with recurrent convolutional layers, reflecting the well-known massive recurrence in the cortex, and show robust increases in predictive performance over feedforward models across thousands of hyperparameter combinations in three datasets of macaque V1 and V2 single-neuron responses. We propose the recurrent circuit can be conceptualized as a form of ensemble computing, with each iteration generating more effective feedforward paths of various path lengths to allow a combination of solutions in the final approximation. The statistics of the paths in the ensemble provide insights to the differential performance increases among our recurrent models. We also assess whether the recurrent circuits learned for neural response prediction can be related to cortical circuits. We find that the hidden units in the recurrent circuits of the appropriate models, when trained on long-duration wide-field image presentations, exhibit similar temporal response dynamics and classical contextual modulations as observed in V1 neurons. This work provides insights to the computational rationale of recurrent circuits and suggests that neural response prediction could be useful for characterizing the recurrent neural circuits in the visual cortex.

Background and Purpose The human gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders. However, its efficacy in preventing non-alcoholic fatty liver disease (NAFLD) and the mechanism involved in its well-known metabolic actions are unknown. The present study explored the therapeutic effect and novel mechanism of A. muciniphila in intervening NAFLD. Experimental Approach The anti-NAFLD activity of A. muciniphila was evaluated in an obese mouse model induced by high-fat and cholesterol (HFC) diets using three different interventions. The gut microbiota composition, beneficial metabolic effects in the gut-liver axis were explored. The level and beneficial metabolic effects of L-aspartate in vitro and in vivo were further determined. Key Results Mice treated with A. muciniphila efficiently reversed NAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in a germ-free mouse model. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress- induced cell apoptosis in the gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above. Conclusion and Implications The anti-NAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut-liver interactions through regulating L-aspartate metabolism. A. muciniphila would be a potent agent for clinical intervention in NAFLD.

Background: Diet manipulation is the basis for prevention of obesity and diabetes. The molecular mechanisms that mediate the diet-based prevention of insulin resistance are not well understood. Here, as proof-of-concept, ginger-derived nanoparticles (GDNP) were used for studying molecular mechanisms underlying GDNP mediated prevention of high-fat diet induced insulin resistance. Methods: Ginger-derived nanoparticles (GDNP) were isolated from ginger roots and administered orally to C57BL/6 high-fat diet mice. Fecal exosomes released from intestinal epithelial cells (IECs) of PBS or GDNP treated high-fat diet (HFD) fed mice were isolated by differential centrifugation. A micro-RNA (miRNA) polymerase chain reaction (PCR) array was used to profile the exosomal miRs and miRs of interest were further analyzed by quantitative real time (RT) PCR. miR-375 or antisense-miR375 was packed into nanoparticles made from the lipids extracted from GDNP. Nanoparticles was fluorescent labeled for monitoring their in vivo trafficking route after oral administration. The effect of these nanoparticles on glucose and insulin response of mice was determined by glucose and insulin tolerance tests. Results: We report that HFD feeding increased the expression of AhR and inhibited the expression of miR-375 and VAMP7. Treatment with orally administered ginger-derived nanoparticles (GDNP) resulted in reversing HFD mediated inhibition of the expression of miR-375 and VAMP7. miR-375 knockout mice exhibited impaired glucose homeostasis and insulin resistance. Induction of intracellular miR-375 led to inhibition of the expression of AhR and VAMP7 mediated exporting of miR-375 into intestinal epithelial exosomes where they were taken up by gut bacteria and inhibited the production of the AhR ligand indole. Intestinal exosomes can also traffic to the liver and be taken up by hepatocytes, leading to miR-375 mediated inhibition of hepatic AhR over-expression and inducing the expression of genes associated with the hepatic insulin response. Altogether, GDNP prevents high-fat diet-induced insulin resistance by miR-375 mediated inhibition of the aryl hydrocarbon receptor mediated pathways over activated by HFD feeding. Conclusion: Collectively our findings reveal that oral administration of GDNP to HFD mice improves host glucose tolerance and insulin response via regulating AhR expression by GDNP induced miR-375 and VAMP7.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel viral pathogen that causes a clinical disease called coronavirus disease 2019 (COVID-19). Approximately 20% of infected patients experience a severe manifestation of the disease, causing bilateral pneumonia and acute respiratory distress syndrome. Severe COVID-19 patients also have a pronounced coagulopathy with approximately 30% of patients experiencing thromboembolic complications. However, the etiology driving the coagulopathy remains unknown. Here, we explore whether the prominent neutrophilia seen in severe COVID-19 patients contributes to inflammation-associated coagulation. We found in severe patients the emergence of a CD16IntCD44lowCD11bInt low-density inflammatory band (LDIB) neutrophil population that trends over time with changes in disease status. These cells demonstrated spontaneous neutrophil extracellular trap (NET) formation, phagocytic capacity, enhanced cytokine production, and associated clinically with D-dimer and systemic IL-6 and TNF-α levels, particularly for CD40+ LDIBs. We conclude that the LDIB subset contributes to COVID-19-associated coagulopathy (CAC) and could be used as an adjunct clinical marker to monitor disease status and progression. Identifying patients who are trending towards LDIB crisis and implementing early, appropriate treatment could improve all-cause mortality rates for severe COVID-19 patients. One Sentence Summary In this study, we discover that low-density neutrophils significantly contribute to COVID-19-associated coagulopathy and inflammation

Within the past decades, extracellular vesicles (EVs) have emerged as important mediators of intercellular communication in both prokaryotes and higher eukaryotes to regulate a diverse range of biological processes. Besides EVs, exosome-like nanoparticles (ELNs) derived from plants were also emerging. Comparing to EVs, ELNs are source-widespread, cost-effective and easy to obtain. Their definite activities can be utilized for potential prevention/treatment of an abundance of diseases, including metabolic syndrome, cancer, colitis, alcoholic hepatitis and infectious diseases, which highlights ELNs as promising biotherapeutics. In addition, the potential of ELNs as natural or engineered drug carriers is also attractive. In this review, we tease out the timeline of plant EVs and ELNs, introduce the arising separation, purification and characterization techniques, state the stability and transport manner, discuss the therapeutic opportunities as well as the potential as novel drug carriers. Finally, the challenges and the direction of efforts to realize the clinical transformation of ELNs are also discussed.

Microglia modulate pro-inflammatory and neurotoxic activities. Edible plant-derived factors improve brain function. Current knowledge of the molecular interactions between edible plant-derived factors and the microglial cell is limited. Here an alcohol-induced chronic brain inflammation model is used to identify that the microglial cell is the novel target of oat nanoparticles (oatN). Oral administration of oatN inhibits brain inflammation and improves brain memory function of mice that are fed alcohol. Mechanistically, ethanol activates dectin-1 mediated inflammatory pathway. OatN is taken up by microglial cells via β-glucan mediated binding to microglial hippocalcin (HPCA) whereas oatN digalactosyldiacylglycerol (DGDG) prevents assess of oatN β-glucan to dectin-1. Subsequently endocytosed β-glucan/HPCA is recruited in an endosomal recycling compartment (ERC) via interaction with Rab11a. This complex then sequesters the dectin-1 in the ERC in an oatN β-glucan dependent manner and alters the location of dectin-1 from Golgi to early endosomes and lysosomes and increases exportation of dectin-1 into exosomes in an Rab11a dependent manner. Collectively, these cascading actions lead to preventing the activation of the alcoholic induced brain inflammation signing pathway(s). This coordinated assembling of the HPCA/Rab11a/dectin-1 complex by oral administration of oatN may contribute to the prevention of brain inflammation.

One of the defining characteristics of a pre-metastatic niche, a fundamental requirement for primary tumor metastasis, is infiltration of immunosuppressive macrophages. How these macrophages acquire their phenotype remains largely unexplored. Here, we demonstrate that tumor-derived exosomes (TDEs) polarize macrophages toward an immunosuppressive phenotype characterized by increased PD-L1 expression through NF-kB-dependent, glycolytic-dominant metabolic reprogramming. TDE signaling through TLR2 and NF-κB leads to increased glucose uptake. TDEs also stimulate elevated NOS2, which inhibits mitochondrial oxidative phosphorylation resulting in increased conversion of pyruvate to lactate. Lactate feeds back on NF-κB, further increasing PD-L1. Analysis of metastasis-negative lymph nodes of non-small-cell lung cancer patients revealed that macrophage PD-L1 positively correlates with levels of GLUT-1 and vesicle release gene YKT6 from primary tumors. Collectively, our study provides a novel mechanism by which macrophages within a pre-metastatic niche acquire their immunosuppressive phenotype and identifies an important link among exosomes, metabolism, and metastasis.

Circulating tumor cells (CTCs) represent the most common way of tumor metastasis and has been considered as a significant index for tumor diagnosis, staging and prognosis. However, CTC detection and analysis are always limited by the scarcity of CTC in the peripheral blood and the interference of blood cells. Therefore, here we presented with a hydrogen peroxide (H

Legionella pneumophila, an environmental bacterium that parasitizes protozoa, is the causative pathogen of Legionnaires' disease. L. pneumophila adopts a distinct biphasic life cycle that allows it to adapt to environmental conditions for survival, replication, and transmission. This cycle consists of a non-virulent replicative phase (RP) and a virulent transmissive phase (TP). Timely and fine-tuned expression of growth and virulence factors in a life cycle-dependent manner is crucial. Herein, we report evidence that CsrA, a key regulator of the switch between the RP and the TP, is dually regulated in a ClpP-dependent manner during the biphasic life cycle of L. pneumophila. First, we show that the protein level of CsrA is temporal during the life cycle and is degraded by ClpP during the TP. The ectopic expression of CsrA in a ΔclpP mutant, but not in the wild type, inhibits both the initiation of the RP in vitro and the invasiveness to Acanthamoeba castellanii, indicating that the ClpP-mediated proteolytic pathway regulates the CsrA protein level. We further show that the temporally expressed IHFB is the transcriptional inhibitor of csrA and is degraded via a ClpP-dependent manner during the RP. During the RP, the level of CsrA is increased by promoting the degradation of IHFB and reducing the degradation of the accumulated CsrA via a ClpP-dependent manner. During the TP, the level of CsrA is decreased by inhibiting the degradation of IHFB and promoting the degradation of the accumulated CsrA via a ClpP-dependent manner as well. In conclusion, our results show that the growth-stage-specific expression level of CsrA is dually regulated by ClpP-dependent proteolysis at both the transcription and protein levels during the biphasic life cycle of L. pneumophila.

Acquired resistance to chemotherapy remains a major stumbling block in cancer treatment. Chronic inflammation has a crucial role in induction of chemoresistance and results, in part, from the induction and expansion of inflammatory cells that include myeloid-derived suppressor cells (MDSCs) and IL-13+ Th2 cells. The mechanisms that lead to induction of activated MDSCs and IL-13+ Th2 cells have not yet been identified. Here we demonstrated that doxorubicin (DOX) treatment of 4T1 breast tumor-bearing mice led to the induction of IL-13R+miR-126a+ MDSCs (DOX-MDSC). DOX-MDSC promote breast tumor lung metastasis through MDSC miR-126a+ exosomal-mediated induction of IL-13+ Th2 cells and tumor angiogenesis. The induction of DOX-MDSC is regulated in a paracrine manner. DOX treatment not only increases interleukin (IL)-33 released from breast tumor cells, which is crucial for the induction of IL-13+ Th2 cells, but it also participates in the induction of IL-13 receptors and miR-126a expressed on/in the MDSCs. IL-13 released from IL-13+Th2 cells then promotes the production of DOX-MDSC and MDSC miR-126a+ exosomes via MDSC IL-13R. MDSC miR-126a+ exosomes further induce IL13+ Th2 cells in a positive feed-back loop manner. We also showed that MDSC miR-126a rescues DOX-induced MDSC death in a S100A8/A9-dependent manner and promotes tumor angiogenesis. Our findings provide insight into the MDSC exosomal-mediated chemoresistance mechanism, which will be useful for the design of inhibitors targeting the blocking of induction of miR-126a+ MDSCs.

Antibody maturation as well as memory B and plasma cell differentiation occur primarily in the germinal centers (GC). Systemic lupus erythemotosus (SLE) may develop as a result of enhanced GC activity. Previous studies have shown that the dysregulated signal transducer and activator of transcription 3 (STAT3) pathway is linked to lupus pathogenesis. However, the exact role of STAT3 in regulating SLE disease progression has not been fully understood. Here, we demonstrated that the STAT3 signaling in B cells is essential for the GC formation and maintenance as well as antibody response. Increased cell apoptosis and down-regulated Bcl-xL and Mcl-1 anti-apoptotic gene expression were found in the STAT3 deficient GC B cells. The Tfh cell response positively correlated with the GC B cells and was significantly decreased in immunized B cell STAT3-deficient mice. STAT3 deficiency also led to the defect of plasma cell differentiation. Furthermore, STAT3 deficiency in autoreactive B cells resulted in decreased autoantibody production. Results obtained from B-cell STAT3 deficient B6.MRL/lpr mice suggest that STAT3 signaling significantly contributes to the SLE pathogenesis by regulation of the GC reactivity, autoantibody production, and kidney pathology. Our findings provide new insights into the role of STAT3 signaling in the maintenance of the GC formation and GC B cell differentiation and identify STAT3 as a novel target for the treatment of SLE.

// Huang-Ge Zhang 1, 2 , Pengxiao Cao 2 , Yun Teng 2 , Xin Hu 4, 5 , Qilong Wang 2, 8 , Ashish S. Yeri 6 , Xiaoying Zhuang 2 , Abhilash Samykutty 2 , Jingyao Mu 2 , Zhong-Bin Deng 3 , Lifeng Zhang 2 , James A. Mobley 7 , Jun Yan 3 , Kendall Van Keuren-Jensen 6 , Donald Miller 3 1 Louisville Veterans Administration Medical Center, Louisville, KY 40206, USA 2 James Brown Cancer Center, Department of Microbiology and Immunology, University of Louisville, KY 40202, USA 3 Department of Medicine, University of Louisville, KY 40202, USA 4 Program in Biostatistics, Bioinformatics and Systems Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, TX 77030, USA 5 Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA 6 Translational Genomics Research Institute, Phoenix, AZ 85004, USA 7 Mass Spectrometry/Proteomics Shared Facility, University of Alabama at Birmingham, Birmingham, AL 35294, USA 8 Department of Clinical Oncology, Huai’an First People’s Hospital, Nanjing Medical University, Huai’an, 223300, China Correspondence to: Huang-Ge Zhang, email: H0Zhan17@louisville.edu Keywords: isolation and identification extracellular microvesicles, in vivo predominately population, HG-NV, exosomes Received: November 12, 2015 Accepted: April 16, 2016 Published: May 12, 2016 ABSTRACT Extracellular microvesicles (EVs) have been recognized for many potential clinical applications including biomarkers for disease diagnosis. In this study, we identified a major population of EVs by simply screening fluid samples with a nanosizer. Unlike other EVs, this extracellular nanovesicle (named HG-NV, HG-NV stands for HomoGenous nanovesicle as well as for Huang-Ge- nanovesicle) can be detected with a nanosizer with minimal in vitro manipulation and are much more homogenous in size (8–12 nm) than other EVs. A simple filtration platform is capable of separating HG-NVs from peripheral blood or cell culture supernatants. In comparison with corresponding exosome profiles, HG-NVs released from both mouse and human breast tumor cells are enriched with RNAs. Tumor derived HG-NVs are more potent in promoting tumor progression than exosomes. In summary, we identified a major subset of EVs as a previously unrecognized nanovesicle. Tumor cell derived HG-NVs promote tumor progression. Molecules predominantly present in breast tumor HG-NVs have been identified and characterized. This discovery may have implications in advancing both microvesicle biology research and clinical management including potential used as a biomarker.

Liver metastasis accounts for many of the cancer deaths in patients. Effective treatment for metastatic liver tumors is not available. Here, we provide evidence for the role of miR-18a in the induction of liver M1 (F4/80+interferon gamma (IFNγ)+IL-12+) macrophages. We found that miR-18a encapsulated in grapefruit-derived nanovector (GNV) mediated inhibition of liver metastasis that is dependent upon the induction of M1 (F4/80+IFNγ+IL-12+) macrophages; depletion of macrophages eliminated its anti-metastasis effect. Furthermore, the miR-18a mediated induction of macrophage IFNγ by targeting IRF2 is required for subsequent induction of IL-12. IL-12 then activates natural killer (NK) and natural killer T (NKT) cells for inhibition of liver metastasis of colon cancer. This conclusion is supported by the fact that knockout of IFNγ eliminates miR-18a mediated induction of IL-12, miR-18a treatment has an anti-metastatic effects in T cell deficient mice but there is no anti-metastatic effect on NK and NKT deficient mice. Co-delivery of miR-18a and siRNA IL-12 to macrophages did not result in activation of co-cultured NK and NKT cells. Taken together our results indicate that miR-18a can act as an inhibitor for liver metastasis through induction of M1 macrophages.

Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that promote tumor progression. In this study, we demonstrated that activation of a C-type lectin receptor, dectin-1, in MDSC differentially modulates the function of different MDSC subsets. Yeast-derived whole β-glucan particles (WGP; a ligand to engage and activate dectin-1, oral treatment in vivo) significantly decreased tumor weight and splenomegaly in tumor-bearing mice with reduced accumulation of polymorphonuclear MDSC but not monocytic MDSC (M-MDSC), and decreased polymorphonuclear MDSC suppression in vitro through the induction of respiratory burst and apoptosis. On a different axis, WGP-treated M-MDSC differentiated into F4/80+CD11c+ cells in vitro that served as potent APC to induce Ag-specific CD4+ and CD8+ T cell responses in a dectin-1–dependent manner. Additionally, Erk1/2 phosphorylation was required for the acquisition of APC properties in M-MDSC. Moreover, WGP-treated M-MDSC differentiated into CD11c+ cells in vivo with high MHC class II expression and induced decreased tumor burden when inoculated s.c. with Lewis lung carcinoma cells. This effect was dependent on the dectin-1 receptor. Strikingly, patients with non–small cell lung carcinoma that had received WGP treatment for 10–14 d prior to any other treatment had a decreased frequency of CD14−HLA-DR−CD11b+CD33+ MDSC in the peripheral blood. Overall, these data indicate that WGP may be a potent immune modulator of MDSC suppressive function and differentiation in cancer.

The lack of access to the brain is a major obstacle for central nervous system drug development. In this study, we demonstrate the capability of a grapefruit-derived nanovector (GNV) to carry miR17 for therapeutic treatment of mouse brain tumor. We show that GNVs coated with folic acid (FA-GNVs) are enhanced for targeting the GNVs to a folate receptor-positive GL-26 brain tumor. Additionally, FA-GNV-coated polyethylenimine (FA-pGNVs) not only enhance the capacity to carry RNA, but the toxicity of the polyethylenimine is eliminated by the GNVs. Intranasal administration of miR17 carried by FA-pGNVs led to rapid delivery of miR17 to the brain that was selectively taken up by GL-26 tumor cells. Mice treated intranasally with FA-pGNV/miR17 had delayed brain tumor growth. Our results demonstrate that this strategy may provide a noninvasive therapeutic approach for treating brain-related disease through intranasal delivery.

Circulating tumor cells (CTCs) represent the most common way of tumor metastasis and has been considered as a significant index for tumor diagnosis, staging and prognosis. However, CTC detection and analysis are always limited by the scarcity of CTC in the peripheral blood and the interference of blood cells. Therefore, here we presented with a hydrogen peroxide (H2O2)-response nanoprobes with CD44-targeted ability to reduce the interference of blood cells and improve the detection efficiency and accuracy and the pancreatic cancer cell was used to evaluate the feasibility of our probe. Shortly, hydrophobic H2O2-response naphthalimide-borate fluorophore was introduced onto the hydrophilic hyaluronic acid to form an amphiphilic complex, which could self-assemble into fluorescent nanoprobes in water. Our studies demonstrated that the nanoprobes were not only able to specifically recognize the pancreatic cancer cells with overexpressed CD44 proteins and reduce the influence of white blood cells in the peripheral blood, but also capable of semi-quantifying H2O2 content in CTCs, Which could be further used as a significant index for tumor clinical evaluation and therapy.

Tuberculosis (TB) is caused by bacterial pathogen Mycobacterium tuberculosis (Mtb) and remains a major health problem worldwide. The increasing prevalence of drug-resistant Mtb strains and the extended duration of anti-TB regimens have created an urgent need for new anti-tuberculosis antibiotics with novel targets or inhibitory strategies. Anthracenedione compound bostrycin has been shown to inhibit the growth of Mtb in vitro and inhibit the activity of the effector protein tyrosine phosphatase (MptpB) secreted by Mtb. In this study, we characterized the proteomic profile of the Mtb strain H37Ra exposed to 1 mg/L and 25 mg/L of bostrycin for 24 h. Bioinformatic analysis of the differential abundant proteins indicated that bostrycin treatment may induce oxidative stress and interfere with essential processes such as synthesis of NAD(+) and the tricarboxylic acid cycle in mycobacteria. Then, the molecular docking of bostrycin and 15 candidates of targeted proteins showed that Rv3684 and Rv1908c got higher scores compared to MptpB, suggesting the direct interaction of bostrycin and these two proteins. Further docking of potential targeted proteins with the functional group-removal derivatives of bostrycin revealed possible key functional groups of bostrycin and provides direction for the modification of bostrycin in future. Biological significance It is a challenging work to determine the potential target(s) of an antibiotic accurately and quickly. In this study, we conducted a proteomic analysis of Mtb responding to the treatment of bostrycin, and provided insight into the inhibiting mechanism of this anti-Mtb compound. The proper interaction of bostrycin and targeted proteins, as well as the interacting residues of targets, and functional groups of bostrycin were also identified within the docking surface, providing a direction for further modification of bostrycin. Our study also suggests a reference for the interaction analysis between mycobacteria and antibiotics, and provides potential targets information for other active anthraquinones.

Summary Plant exosomes protect plants against infection; however, whether edible plant exosomes can protect mammalian hosts against infection is not known. In this study, we show that ginger exosome-like nanoparticles (GELNs) are selectively taken up by the periodontal pathogen Porphyromonas gingivalis in a GELN phosphatidic acid (PA) dependent manner via interactions with hemin-binding protein 35 (HBP35) on the surface of P. gingivalis. Compared with PA (34:2), PA (34:1) did not interact with HBP35, indicating that the degree of unsaturation of PA plays a critical role in GELN-mediated interaction with HBP35. On binding to HBP35, pathogenic mechanisms of P. gingivalis were significantly reduced following interaction with GELN cargo molecules, including PA and miRs. These cargo molecules interacted with multiple pathogenic factors in the recipient bacteria simultaneously. Using edible plant exosome-like nanoparticles as a potential therapeutic agent to prevent/treat chronic periodontitis was further demonstrated in a mouse model., Graphical Abstract, Highlights • Plant exosomes-like nanoparticles (ELNs) are selectively taken up by P. gingivalis • The degree of unsaturation of ELNs phosphatidic acid determines uptake specificity • ELN PA and miRs target multiple pathogenic factors of P. gingivalis • Orally taking ginger ELNs ameliorates bone loss induced by P. gingivalis, Bacteriology; Biochemistry; Biological Sciences; Immunology; Microbiology; Molecular Biology; Oral Microbiology

A mutation in STAT3 has been linked to the incidence of autosomal dominant hyper IgE syndrome, a disease characterized by elevated serum IgE Ab. However, how this genetic mutation leads to the phenotype has not been fully understood. We investigated the specific role of STAT3 in the germinal center (GC) B cells and plasma cells for IgE class switching. Through the use of STAT3 conditional knockout (cKO) mice in a Th2-type immunization model, we demonstrated that CD2-Cre–driven STAT3 cKO mice showed elevated IgE and decreased IgG1 in the serum and a reduction in GC formation. Within the GC, IgG1+ GC B cells were decreased, whereas IgE+ GC B cells were more prevalent. Additionally, these mice exhibited reduced IgG1 and elevated IgE populations of Ab-producing plasma cells. Subsequent experiments using a CD19-Cre cKO mouse established this effect to be B cell–intrinsic. Transcription factors critical for GC and plasma cell differentiation, including Bcl-6 and Aicda, were shown to function as downstream signals of STAT3 regulation. Chromatin immunoprecipitation sequencing analysis revealed that many genes, including Bcl3 and Crtc2, were among the direct STAT3 regulated targets. Mice with STAT3 deficiency in B cells also demonstrated an increase in lung inflammation when used in an asthma-like disease model. This model suggests a negative role for STAT3 in regulating class switching of the GC B cells from the IgG1 to the IgE producing state, which may serve as a therapeutic target for treatment of autosomal dominant hyper IgE syndrome and other immune disorders.

Exosomes have shown increasing potential as delivery vesicles for therapy, but challenges like cost/yield, drug payload, and targeting specificity still exist. Plant derived exosome-like nanoparticles have been reported as a promising substitution and exhibit biocompatibility through oral, intranasal administration; however, systemic delivery of siRNA by exosome-like nanoparticles directly isolated from plants has not been reported. Recently, we reported the control of RNA orientation to decorate human derived exosome with cell targeting ligands for specific delivery of siRNA to tumors. Here, we expand to the application of arrowtail RNA nanoparticles for displaying ligands on ginger derived exosome-like nanovesicles (GDENs) for siRNA delivery and tumor inhibition through IV administration. Cushion ultracentrifugation coupled with equilibrium density gradient ultracentrifugation were used for purifying GDENs that displayed size, density, and morphology similar to human derived exosomes. Folic acid (FA), as a ligand, was displayed on the surface of GDENs for targeted delivery of survivin siRNA to KB cancer models. In vitro gene knockdown efficacy by FA-3WJ/GDENs/siRNA complex was comparable to transfection. We observed inhibition of tumor growth on a xenograft model by intravenous administration, which reveals the potential of GDENs as an economic delivery system for siRNA.

Tumor-specific delivery of therapeutics is challenging. One of the major hurdles for successfully delivering targeted agents by nanovectors is the filtering role of the liver in rapidly sequestering nanovectors from the circulation. Exosomes, a type of endogenous nanoparticle, circulate continuously in the peripheral blood and play a role in intercellular communication. The aim of this study was to determine whether the level of endogenous exosomes has an effect on nanovector delivery efficiency of targeted agents. Methods: Exosomes were isolated from peripheral blood and intravenously (I.V.) injected into tumor-bearing mice. Subsequently, 1,1-dioctadecyl-3,3,3'3'-tetramethylindotricarbocyanine-iodide (DiR) fluorescent dye-labeled nanoparticles, including grapefruit nanovectors (GNV) and standard liposomes, were I.V. injected in the mice. The efficiency of redirecting GNVs from liver to other organs of injected mice was further analyzed with in vivo imaging. The concentration of chemo drugs delivered by GNV was measured by HPLC and the anti-lung metastasis therapeutic effects of chemo drugs delivered by GNVs in mouse breast cancer and melanoma cancer models were evaluated. Results: We show that tail vein-injected exosomes isolated from mouse peripheral blood were predominately taken up by liver Kupffer cells. Injection of peripheral blood-derived exosomes before I.V. injection of grapefruit-derived nanovector (GNV) decreased the deposition of GNV in the liver and redirected the GNV to the lung and to the tumor in breast and melanoma tumor-bearing mouse models. Enhanced therapeutic efficiency of doxorubicin (Dox) or paclitaxel (PTX) carried by GNVs for lung metastases was demonstrated when there was an I.V. injection of exosomes before therapeutic treatment. Furthermore, we found that CD36 and IGFR1 receptor-mediated pathways played a critical role in the exosome-mediated inhibitory effect of GNV entry into liver macrophages. Conclusions: Collectively, our findings provide a foundation for using autologous exosomes to enhance therapeutic vector targeted delivery to the lung.