B,N-Embedded Hetero[9]helicene Toward Highly Efficient Circularly Polarized Electroluminescence.

The intrinsic helical π-conjugated skeleton makes helicenes highly promising for circularly polarized electroluminescence (CPEL). Generally, carbon helicenes undergo low external quantum efficiency (EQE), while the incorporation of a multi-resonance thermally activated delayed fluorescence (MR-TADF) BN structure has led to an improvement. However, the reported B,N-embedded helicenes all show low electroluminescence dissymmetry factors (gEL), typically around 1×10-3. Therefore, the development of B,N-embedded helicenes with both a high EQE and gEL value is crucial for achieving highly efficient CPEL. Herein, a facile approach to synthesize B,N-embedded hetero[9]helicenes, BN[9]H, is presented. BN[9]H shows a bright photoluminescence with a maximum at 578 nm with a high luminescence dissymmetry factor (|glum|) up to 5.8×10-3, attributed to its inherited MR-TADF property and intrinsic helical skeleton. Furthermore, circularly polarized OLED devices incorporating BN[9]H as an emitter show a maximum EQE of 35.5 %, a small full width at half-maximum of 48 nm, and, more importantly, a high |gEL| value of 6.2×10-3. The Q-factor (|EQE×gEL|) of CP-OLEDs is determined to be 2.2×10-3, which is the highest among helicene analogues. This work provides a new approach for the synthesis of higher helicenes and paves a new way for the construction of highly efficient CPEL materials.

Synthesis of Highly Luminescent Chiral Nanographene.

Chiral nanographenes with both high fluorescence quantum yields (ΦF ) and large dissymmetry factors (glum ) are essential to the development of circularly polarized luminescence (CPL) materials. However, most studies have been focused on the improvement of glum , whereas how to design highly emissive chiral nanographenes is still unclear. In this work, we propose a new design strategy to achieve chiral nanographenes with high ΦF by helical π-extension of strongly luminescent chromophores while maintaining the frontier molecular orbital (FMO) distribution pattern. Chiral nanographene with perylene as the core and two dibenzo[6]helicene fragments as the wings has been synthesized, which exhibits a record high ΦF of 93 % among the reported chiral nanographenes and excellent CPL brightness (BCPL ) of 32 M-1 cm-1 .

[RNA m 6A Modification and Its Roles in Immune Function Regulation].

N 6-methyladenosine (m 6A) is the most prevalent post-transcriptional RNA modification in eukaryotic cells. m 6A methyltransferase complexes and demethylases are involved in the dynamic and reversible regulation of m 6A modification, while m 6A binding proteins could specifically identify m 6A modification and regulate RNA metabolism, including splicing, translocation, stability, and translation. m 6A is found to play a vital role in all the fundamental biological processes, including the regulation of the immune system, from normal development to diseases. The normal development and functioning of the immune system rely on the precise regulation of the relevant gene expression, and m 6A modification is crucial to the regulation. Herein, we reviewed the concept, the functions, and the mechanism of m 6A modification, concentrating on its role in immune system function modulation. Furthermore, we highlighted present obstacles and future research directions in the field, intending to provide a theoretical foundation and reference for future study on how m 6A modification is involved in immune regulation.

Anxiety and depression-like behaviours are more frequent in aged male mice conceived by ART compared with natural conception.

The number of children born after assisted reproductive technology (ART) is accumulating rapidly, and the health problems of the children are extensively concerned. This study aims to evaluate whether ART procedures alter behaviours in male offspring. Mouse models were utilized to establish three groups of offspring conceived by natural conception (NC), in vitro fertilization and embryo transfer (IVF-ET), and frozen-thawed embryo transfer (IVF-FET), respectively. A battery of behaviour experiments for evaluating anxiety and depression levels, including the open field test (OFT), elevated plus maze (EPM) test, light/dark transition test (L/DTT), tail suspension test (TST), forced swimming test (FST), and sucrose preference test (SPT) was carried out. Aged (18 months old), but not young (3 months old), male offspring in the IVF-ET and IVF-FET groups, compared with those in the NC group, exhibited increased anxiety and depression-like behaviours. The protein expression levels of three neurotrophins in PFC or hippocampus in aged male offspring from the IVF-ET and IVF-FET groups reduced at different extent, in comparison to NC group. RNA sequencing (RNA-Seq) was performed in the hippocampus of 18 months old offspring to further explore the gene expression profile changes in the three groups. KEGG analyses revealed the coexisted pathways, such as PI3K-Akt signalling pathway, which potentially reflected the similarity and divergence in anxiety and depression between the offspring conceived by IVF-ET and IVF-FET. Our research suggested the adverse effects of advanced age on the psychological health of children born after ART should be highlighted in the future.

Chiral TADF-Active Polymers for High-Efficiency Circularly Polarized Organic Light-Emitting Diodes.

A strategy of chiral donor-acceptor copolymerization is proposed to develop chiral nonconjugated polymers with thermally activated delayed fluorescence (TADF). Based on this strategy, two pairs of chiral polymers (R,R)-/(S,S)-pTpAcDPS and (R,R)-/(S,S)-pTpAcBP were synthesized. The alternating copolymerization of the chiral donors and acceptors could effectively separate the frontier molecular orbitals, which made the polymers show small ΔEST of 0.01-0.03 eV and efficient TADF properties. Moreover, the polymers also showed the quantum yield of up to 92 % and the circularly polarized luminescence. The solution-processed circularly polarized organic light-emitting diodes showed circularly polarized electroluminescence signals with high external quantum efficiencies of up to 22.1 % and maximum luminance of up to 34350 cd m-2 . This is the first report of CP-OLEDs based on chiral TADF polymer, which provides a useful and valuable guidance for the development of high-efficiency CPEL polymers.

[RHNO1: A novel noncoding RNA highly expressed in the testis and involved in DNA double-strand break repair].

OBJECTIVE: To investigate the role of a long noncoding RNA (lncRNA) transcribed from the RHNO1 gene we newly identified in DNA double-strand break (DSB) repair. METHODS: The transcription and translation of the RHNO1 gene were validated by Western blot, real-time PCR and liquid chromatography-tandem mass spectrometry (LC-MS/MS) based on the overexpressed RHNO1 plasmid. The transcription level of RHNO1 in the mouse tissue was detected by real-time PCR and its expression in the spermatogenic cycle determined by in situ hybridization. The role of RHNO1 in the DNA DSB repair was further verified using the DSB model established by exposing the germ cells to ultraviolent radiation. RESULTS: The full-length RHNO1 gene could be transcribed as a novel lncRNA in vitro, highly expressed in the mouse testis tissue, and mainly located in spermatocytes and round spermatids. RHNO1 was involved in DNA DSB repair in the spermatogenic cells. CONCLUSIONS: We identified a novel lncRNA, RHNO1, which is highly expressed in the mouse testis and participates in DNA damage repair in the germ cell line.

Comparative analysis of mammalian sperm ultrastructure reveals relationships between sperm morphology, mitochondrial functions and motility.

BACKGROUND: Sperm morphology mainly refers to the shape of the head, the length of the flagellar segments, including the midpiece, principal piece and end piece, and the size of the accessory structures, including axonemes, outer dense fibers (ODFs), mitochondrial sheath (MS) and fibrous sheath (FS). Across species, there is considerable diversity in morphology. An established theory posits that the length of the sperm flagellum, especially the length of the midpiece, is a critical factor influencing sperm metabolism and velocity. However, our understanding of the relationships between sperm ultrastructures and the sperm flagellar length is incomplete. METHODS: The morphologies of sperm from 10 mammalian species, human, mouse, rat, dog, rabbit, goat, pig, bull, guinea pig and golden hamster, were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the SEM and TME images, the length of sperm heads and flagellar segments, the cross-sectional areas of the accessory structures and flagella and the width of sperm heads were measured using Image J software. The variation tendencies (referred to as slope) of the accessory structures along flagella were calculated by the linear regression method. Mitochondrial functions were measured using commercial kits. The velocities of sperm were measured using CASA software. RESULTS: The three-dimensional morphologies of sperm from 10 species and the slopes of internal accessory structures along flagella were obtained. The width of the axoneme tapered slightly from the base to the tip of the sperm flagellum, and slopes of the axonemes correlated negatively with the variability in flagellar length across species. Additionally, the cross-sectional areas of the ODFs and/or the MS were positively correlated with the lengths of the midpiece, principal piece, and total flagellum, as well as with sperm velocities. Mitochondrial volumes were positively correlated with ATP content and sperm swimming velocities. CONCLUSIONS: Our results not only show the relationship between sperm internal structures, flagellar length and sperm physiology but also provide sizes of mitochondria and ODFs as new targets with which to study the regulation of sperm length and velocity.

Anti-Cancer Effects of Emodin on HepG2 Cells as Revealed by 1H NMR Based Metabolic Profiling.

Hepatic carcinoma is one of the most common cancers in the world, with a high incidence. Emodin is an anthraquinone derived from Polygonum multiflorum Thunb, possessing anti-cancer activity. The purpose of this study is to investigate the anti-cancer effect of different dosages of emodin on HepG2 cells using a 1H NMR based metabolic approach complemented with qRT-PCR and flow cytometry to identify potential markers and discover the targets to explore the underlying mechanism. Emodin can dose-dependently inhibit the growth of HepG2 cells, perturb cell cycle progression, down-regulate the expression of genes and proteins related to glycolysis, and trigger intracellular ROS generation. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) and correlation network analysis of the 1H NMR data showed significant changes in many endogenous metabolites after emodin exposure concerning oxidative stress and disturbances in amino acid and energy metabolism. These findings are helpful to understand the anti-cancer mechanism of emodin and provide a theoretical basis for its future application and development.

[Production regionalization study of Isatidis Radix].

In this research, we collected information of eighty nine sampling points of Isatidis Radix nationwide through data query and field survey, and the medicinal component contents of samples were determined by HPLC. By using Maxent Model and ArcGIS, along with ecological factor data, the national habitat suitability distribution of Isatidis Radix was predicted. R-language was adopted to establish a model of the relationship between the medicinal component contents and ecological factors. The medicinal quality was divided by ArcGIS grid computing. The results indicated that the three main ecological factors affecting the distribution of Isatidis Radix were precipitation in the driest season, mean annual temperature and mean temperature in the wet season. The suitable cultivation region of Isatidis Radix is mainly distributed in the north of China, but the medicinal quality is quite different, Isatidis Radix in Xinjiang province has higher medicinal quality. This study provides a reference for rational selection of planting areas of Isatidis Radix.

Bergapten promotes bone marrow stromal cell differentiation into osteoblasts in vitro and in vivo.

Many recent studies have suggested that bergapten (BP), a class of native compound with numerous biological activities such as anti-resorptive properties, may exert protective effects against postmenopausal bone loss. However, it remains unknown whether BP regulates or improves the osteogenic function of bone marrow stromal cells (BMSCs) in the treatment and prevention of osteoporosis. In our study, BMSCs were cultured in osteogenic induction medium with the addition of BP for 2 weeks and an ovariectomized mouse model of osteoporosis was used to investigate the anti-resorptive effect of BP by gavage administration for 3 months. The concentrations of BP used were 0.1, 1, and 10 µmol/L in vitro and the gavage dose was 20 mg/kg/d. The result of our study indicated that BP promotes the expression of alkaline phosphatase (ALP) by BMSCs in vitro in a dose-dependent manner, as revealed by ALP staining. Runt-related transcription factor 2 and osteocalcin were up-regulated both in vitro and vivo, while osterix and collagen Iα1, assessed by immunofluorescence and immunohistochemistry, were correspondingly raised in the presence of BP in BMSCs in vitro. In addition, a protective effect of BP against ovariectomy-induced bone loss was found by distal femur micro-CT scanning, with improvements of bone metabolism parameters such as bone mineral density, trabecular number, and trabecular separation. Furthermore, WNT/ß-catenin signaling was activated in the presence of BP in BMSCs in osteogenic culture. Finally, BP promoted differentiation of BMSCs into osteoblasts by up-regulation of the WNT/ß-catenin pathway.

Relationship between Eimeria tenella development and host cell apoptosis in chickens.

Coccidiosis causes considerable economic losses in the poultry industry. At present, the pathology of coccidiosis is preventable with anticoccidials and vaccination, although at considerable cost to the international poultry industry. The purpose of the present study was to elucidate the relationship between Eimeria tenella development and host cell apoptosis in chickens, which provides a theoretical basis for further study of the injury mechanism of E. tenella and the prevention and treatment of coccidiosis. Cecal epithelial cells from chick embryo were used as host cells in vitro. In addition, flow cytometry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end labeling, and histopathological assays were used to detect the dynamic changes in E. tenella infection rates, DNA injury rates, and apoptosis rates in groups treated with and without the caspase-9 inhibitor Z-LEHD-FMK. Following E. tenella infection, we demonstrated that untreated cells had less apoptosis at 4 h and, inversely, more apoptosis at 24 to 120 h compared with control cells. Furthermore, after the application of Z-LEHD-FMK, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, and translation of phosphatidyl serines to the host cell plasma membrane surface, the treated group chick embryo cecal epithelial cells exhibited decreased apoptosis and DNA injuries (P<0.01) at 24 to 120 h. However, light microscopy showed that E. tenella infection rates of treated cells were higher (P<0.01) than untreated cells during the whole experimental period. Together, these observations suggest that E. tenella can protect host cells from apoptosis at early stages of development but can promote apoptosis during the middle to late stages. In addition, the inhibition of host cell apoptosis can be beneficial to the intracellular growth and development of E. tenella.

Acceptor Copolymerized Axially Chiral Conjugated Polymers with TADF Properties for Efficient Circularly Polarized Electroluminescence.

Chiral conjugated polymer has promoted the development of the efficient circularly polarized electroluminescence (CPEL) device, nevertheless, it remains a challenge to develop chiral polymers with high electroluminescence performance. Herein, by the acceptor copolymerization of axially chiral biphenyl emitting skeleton and benzophenone, a pair of axially chiral conjugated polymers namely R-PAC and S-PAC are synthesized. The target polymers exhibit obvious thermally activated delayed fluorescence (TADF) activities with high photoluminescence quantum yields of 81%. Moreover, the chiral polymers display significant circularly polarized luminescence features, with luminescence dissymmetry factor (|glum|) of nearly 3 × 10-3. By using the chiral polymers as emitters, the corresponding circularly polarized organic light-emitting diodes (CP-OLEDs) exhibit efficient CPEL signals with electroluminescence dissymmetry factor |gEL| of 3.4 × 10-3 and high maximum external quantum efficiency (EQEmax) of 17.8%. Notably, considering both EQEmax and |gEL| comprehensively, the device performance of R-PAC and S-PAC is the best among all the reported CP-OLEDs with chiral conjugated polymers as emitters. This work provides a facile approach to constructing chiral conjugated TADF polymers and discloses the potential of axially chiral conjugated luminescent skeletons in architecting high-performance CP-OLEDs.

Detection of pTDP-43 via routine muscle biopsy: A promising diagnostic biomarker for amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease, pathologically characterized by TDP-43 aggregates. Recent evidence has been indicated that phosphorylated TDP-43 (pTDP-43) is present not only in motor neurons but also in muscle tissues. However, it is unclear whether testing pTDP-43 aggregation in muscle tissue would assist in the diagnosis of ALS. We propose three key questions: (i) Is aggregation of pTDP-43 detectable in routine biopsied muscles? (ii) Can detection of pTDP-43 aggregation discriminate between ALS and non-ALS patients? (iii) Can pTDP-43 aggregation be observed in the early stages of ALS? We conducted a diagnostic study comprising 2 groups: an ALS group in which 18 cases underwent muscle biopsy screened from a registered ALS cohort consisting of 802 patients and a non-ALS control group, in which we randomly selected 54 muscle samples from a biospecimen bank of 684 patients. Among the 18 ALS patients, 3 patients carried pathological GGGGCC repeats in the C9ORF72 gene, 2 patients carried SOD1 mutations, and 7 patients were at an early stage with only one body region clinically affected. The pTDP-43 accumulation could be detected in routine biopsied muscles, including biceps brachii, deltoid, tibialis anterior, and quadriceps. Abnormal aggregation of pTDP-43 was present in 94.4% of ALS patients (17/18) compared to 29.6% of non-ALS controls (16/54; p < 0.001). The pTDP-43 aggregates were mainly close to the sarcolemma. Using a semi-quantified pTDP-43 aggregates score, we applied a cut-off value of 3 as a diagnostic biomarker, resulting in a sensitivity of 94.4% and a specificity of 83.3%. Moreover, we observed that accumulation of pTDP-43 occurred in muscle tissues prior to clinical symptoms and electromyographic lesions. Our study provides proof-of-concept for the detection of pTDP-43 accumulation via routine muscle biopsy which may serve as a novel biomarker for diagnosis of ALS.

Bis{1-[(1H-benzimidazol-1-yl)meth-yl]-1H-imidazole-κN (3)}bis-(3,5-dicarb-oxy-benzoato-κ(2) O (1),O (1'))nickel(II) octa-hydrate.

In the title complex, [Ni(C9H5O6)2(C11H10N4)2]·8H2O, the Ni(II) ion exhibits site symmetry 2. It has a distorted octa-hedral coordination defined by two N atoms from two symmetry-related 1-[(1H-benzimidazol-1-yl)meth-yl]-1H-imidazole ligands and four O atoms from two symmetry-related 3,5-dicarb-oxy-benzoate anions. In the crystal, the complex mol-ecules and solvent water mol-ecules are linked via O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds, forming a three-dimensional structure. There are also a number of C-H⋯O inter-actions present.

[Verification of processing theory of "reducing ketone and dryness, and increasing ester and effect" for bran-fried atractylodes].

We previously proposed the processing theory of "reducing ketone and dryness, and increasing ester and effect" for bran-fried atractylodes, and made a preliminary study. To further verify the science and rationality of the theory, we determined the changes in the content of atractylenolide I, II, III and atractylon in atractylodes after and before being fried with bran, in order to compare the effect of raw and bran-fried atractylodes on the water intake and urination in rats in this study. The effect of raw and bran-fried atractylodes on the content of four gastrointestinal hormones and two neurotransmitters in serum was observed in an attempt to verify the science and rationality the processing theory of "reducing ketone and dryness, and increasing ester and effect" for bran-fried atractylodes.

Torachrysone-8-O-ß-d-glucoside mediates anti-inflammatory effects by blocking aldose reductase-catalyzed metabolism of lipid peroxidation products.

Aldose reductase (AR) is an important enzyme involved in the reduction of various aldehyde and carbonyl compounds, including the highly reactive and toxic 4-hydroxynonenal (4-HNE), which has been linked to the progression of various pathologies such as atherosclerosis, hyperglycemia, inflammation, and tumors. AR inhibitors have potential therapeutic benefits for these diseases by reducing lipid peroxidation and mitigating the harmful effects of reactive aldehydes. In this study, we found that torachrysone-8-O-ß-d-glucoside (TG), a natural product isolated from Polygonum multiflorum Thunb., functions as an effective inhibitor of AR, exhibiting potent effects in clearing reactive aldehydes and reducing inflammation. TG up-regulated the mRNA levels of several antioxidant factors downstream of NRF2, especially glutathione S-transferase (GST), which is significantly increased, thus detoxifying 4-HNE by facilitating the conjugation of 4-HNE to glutathione, forming glutathione-4-hydroxynonenal (GS-HNE). By employing a combination of molecular docking, cellular thermal shift assay, and enzyme activity experiments, we demonstrated that TG exhibited strong binding affinity with AR and inhibited its activity and blocked the conversion of GS-HNE to glutathionyl-1,4-dihydroxynonene (GS-DHN), thereby preventing the formation of protein adducts and inducing severe cellular damage. This study provides novel insights into the anti-inflammatory mechanisms of AR inhibitors and offers potential avenues for developing therapeutic strategies for AR-related pathologies. Our findings suggest that TG, as an AR inhibitor, may hold promise as a therapeutic agent for treating conditions characterized by excessive lipid peroxidation and inflammation. Further investigations are needed to fully explore the clinical potential of TG and evaluate its efficacy in the treatment and management of these complex diseases.

Collateral circulation status-guided mechanical thrombectomy in pediatric stroke with an extended ghost infarct core: illustrative case.

BACKGROUND: Mechanical thrombectomy (MT) has been proved to be a highly effective therapy to treat acute ischemic stroke due to large vessel occlusion. Often, the ischemic core extent on baseline imaging is an important determinant for endovascular treatment eligibility. However, computed tomography (CT) perfusion (CTP) or diffusion-weighted imaging may overestimate the infarct core on admission and, consequently, smaller infarct lesions called "ghost infarct cores." OBSERVATIONS: A 4-year-old, previously healthy boy presented with acute-onset, right-sided weakness and aphasia. Fourteen hours after the onset of symptoms, the patient presented with a National Institutes of Health Stroke Scale (NIHSS) score of 22, and magnetic resonance angiography demonstrated a left middle cerebral artery occlusion. MT was not considered because of a large infarct core (infarct core volume: 52 mL; mismatch ratio 1.6 on CTP). However, multiphase CT angiography indicated good collateral circulation, which encouraged MT. Complete recanalization was achieved via MT at 16 hours after the onset of symptoms. The child's hemiparesis improved. Follow-up magnetic resonance imaging was nearly normal and showed that the baseline infarct lesion was reversible, in agreement with neurological improvement (NIHSS score 1). LESSONS: The selection of pediatric stroke with a delayed time window guided by good collateral circulation at baseline seems safe and efficacious, which suggests a promising value of vascular window.

Study on the acute toxicity of trichlorfon and its breakdown product dichlorvos to goldfish (Carassius auratus) based on 1H NMR metabonomics.

Trichlorfon, one of the most widely used organophosphate insecticides, is commonly employed in aquaculture and agriculture to combat parasitic infestations. However, its inherent instability leads to rapid decomposition into dichlorvos (DDVP), increasing its toxicity by eightfold. Therefore, the environmental effects of trichlorfon in real-world scenarios involve the combined effects of trichlorfon and its degradation product, DDVP. In this study, we systematically investigated the degradation of trichlorfon in tap water over time using HPLC and LC-MS/MS analysis. Subsequently, an experiment was conducted to assess the acute toxicity of trichlorfon and DDVP on goldfish (Carassius auratus), employing a 1H NMR-based metabolic approach in conjunction with serum biochemistry, histopathological inspection, and correlation network analysis. Exposure to trichlorfon and its degradation product DDVP leads to increased lipid peroxidation, reduced antioxidant activity, and severe hepatotoxicity and nephrotoxicity in goldfish. Based on the observed pathological changes and metabolite alterations, short-term exposure to trichlorfon significantly affected the liver and kidney functions of goldfish, while exerting minimal influence on the brain, potentially due to the presence of the blood-brain barrier. The changes in the metabolic profile indicated that trichlorfon and DDVP influenced several pathways, including oxidative stress, protein synthesis, energy metabolism, and nucleic acid metabolism. This study demonstrated the applicability and potential of 1H NMR-based metabonomics in pesticide environmental risk assessment, providing a feasible method for the comprehensive study of pesticide toxicity in water environments.

Activatable Near-Infrared Fluorescent and Photoacoustic Dual-Modal Probe for Highly Sensitive Imaging of Sulfatase In Vivo.

Sulfatase is an important biomarker closely associated with various diseases. However, the state-of-the-art sulfatase probes are plagued with a short absorption/emission wavelength and limited sensitivity. Developing highly sensitive fluorescent probes for in vivo imaging of sulfatase remains a grand challenge. Herein, for the first time, an activatable near-infrared fluorescence/photoacoustic (NIRF/PA) dual-modal probe (Hcy-SA) for visualizing sulfatase activity in living cells and animals is developed. Hcy-SA is composed of a sulfate ester moiety as the recognition unit and a NIR fluorophore hemicyanine (Hcy-OH) as the NIRF/PA reporter. The designed probe exhibits a rapid response, excellent sensitivity, and high specificity for sulfatase detection in vitro. More importantly, cells and in vivo experiments confirm that Hcy-SA can be successfully applied for PA/NIRF dual-modal imaging of sulfatase activity in living sulfatase-overexpressed tumor cells and tumor-bearing animals. This probe can serve as a promising tool for sulfatase-related pathological research and cancer diagnosis.

Cellular internalization of exosomes occurs through phagocytosis.

Exosomes play important roles in many physiological and pathological processes. However, the exosome-cell interaction mode and the intracellular trafficking pathway of exosomes in their recipient cells remain unclear. Here, we report that exosomes derived from K562 or MT4 cells are internalized more efficiently by phagocytes than by non-phagocytic cells. Most exosomes were observed attached to the plasma membrane of non-phagocytic cells, while in phagocytic cells these exosomes were found to enter via phagocytosis. Specifically, they moved to phagosomes together with phagocytic polystyrene carboxylate-modified latex beads (biospheres) and were further sorted into phagolysosomes. Moreover, exosome internalization was dependent on the actin cytoskeleton and phosphatidylinositol 3-kinase, and could be inhibited by the knockdown of dynamin2 or overexpression of a dominant-negative form of dynamin2. Further, antibody pretreatment assays demonstrated that tim4 but not tim1 was involved in exosomes uptake. We also found that exosomes did not enter the internalization pathway involving caveolae, macropinocytosis and clathrin-coated vesicles. Our observation that the cellular uptake of exosomes occurs through phagocytosis has important implications for exosome-cell interactions and the exosome intracellular trafficking pathway.