Human ß-defensin-1 affects the mammalian target of rapamycin pathway and autophagy in colon cancer cells through long non-coding RNA TCONS_00014506.

BACKGROUND: Colorectal cancer has a low 5-year survival rate and high mortality. Human ß-defensin-1 (hBD-1) may play an integral function in the innate immune system, contributing to the recognition and destruction of cancer cells. Long non-coding RNAs (lncRNAs) are involved in the process of cell differentiation and growth. AIM: To investigate the effect of hBD-1 on the mammalian target of rapamycin (mTOR) pathway and autophagy in human colon cancer SW620 cells. METHODS: CCK8 assay was utilized for the detection of cell proliferation and determination of the optimal drug concentration. Colony formation assay was employed to assess the effect of hBD-1 on SW620 cell proliferation. Bioinformatics was used to screen potentially biologically significant lncRNAs related to the mTOR pathway. Additionally, p-mTOR (Ser2448), Beclin1, and LC3II/I expression levels in SW620 cells were assessed through Western blot analysis. RESULTS: hBD-1 inhibited the proliferative ability of SW620 cells, as evidenced by the reduction in the colony formation capacity of SW620 cells upon exposure to hBD-1. hBD-1 decreased the expression of p-mTOR (Ser2448) protein and increased the expression of Beclin1 and LC3II/I protein. Furthermore, bioinformatics analysis identified seven lncRNAs (2 upregulated and 5 downregulated) related to the mTOR pathway. The lncRNA TCONS_00014506 was ultimately selected. Following the inhibition of the lncRNA TCONS_00014506, exposure to hBD-1 inhibited p-mTOR (Ser2448) and promoted Beclin1 and LC3II/I protein expression. CONCLUSION: hBD-1 inhibits the mTOR pathway and promotes autophagy by upregulating the expression of the lncRNA TCONS_00014506 in SW620 cells.

Apoptotic Extracellular Vesicles Induced Endothelial Cell-Mediated Autologous Stem Cell Recruitment Dominates Allogeneic Stem Cell Therapeutic Mechanism for Bone Repair.

Although stem cell therapy is proved to be a promising strategy for bone repair and regeneration, transplanted allogeneic stem cells generally suffer from unfavorable apoptosis instead of differentiation into osteocytes. How the apoptotic stem cells promote bone regeneration still needs to be uncovered. In this work, we found that apoptotic extracellular vesicles released by allogeneic stem cells are critical mediators for promoting bone regeneration. Based on the results of in vivo experiments, a mechanism of apoptotic stem cells determined autologous stem cell recruitment and enhance osteogenesis was proposed. The nanoscaled apoptotic extracellular vesicles released from transplanted stem cells were endocytosed by vascular endothelial cells and preferentially distribute at endoplasmic reticular region. The oxidized phosphatidylcholine enriched in the vesicles activated the endoplasmic reticulum stress and triggered the reflective elevation of adhesion molecules, which induced the recruitment of autologous stem cells located in the blood vessels, transported them into the defect region, and promoted osteogenesis and bone repair. These findings not only reveal the mechanism of stem cell therapy of bone defects but also provide a cue for investigation of the biological process of stem cell therapy for other diseases and develop stem cell therapeutic strategies.

MUC1 promotes RIF by regulating macrophage ROS-SHP2 signaling pathway to up-regulate inflammatory response and inhibit angiogenesis.

OBJECTIVE: To explore the effect of MUC1 on recurrent implantation failure (RIF) and its molecular mechanism. METHODS: Bioinformation analysis was used to find possible molecular mechanisms of specific genes in the pathogenesis of RIF. The number of M1 and M2 macrophages was measured by flow cytometry. Immunohistochemical staining and western blotting were used to detect the expression of related proteins. Angiogenesis capacity was measured by cell tube-formation assay. RESULTS: Bioinformatics analysis results suggest that MUC1 may play an important role in RIF. The results of flow cytometry showed that compared with NC group, M1 macrophages increased significantly and M2 macrophages decreased significantly in MUC1 OE group. The results of immunohistochemical staining showed that MUC1 could inhibit the expression of VEGF. Western blotting results showed that MUC1 could significantly increase the expression of P22, P47, gp91, p-TBK1, IFNγ and IL-1ß, and decrease the expression of p-SHP2, p-PI3K, p-mTOR, HIF1α and VEGF. After the addition of ROS inhibitor and PI3K inhibitor, the effect of MUC1 on the above proteins was eliminated. The results of tube formation experiments showed that MUC1 could inhibit vascular formation. CONCLUSION: As a promising biomarker for the diagnosis of RIF, MUC1 can promote RIF by regulating macrophage ROS-SHP2 signaling pathway to up-regulate inflammatory response and inhibit angiogenesis.

Stiffness promotes cell migration, invasion, and invadopodia in nasopharyngeal carcinoma by regulating the WT-CTTN level.

Matrix stiffness potently promotes the malignant phenotype in various biological contexts. Therefore, identification of gene expression to participate in mechanical force signals transduced into downstream biochemical signaling will contribute substantially to the advances in nasopharyngeal carcinoma (NPC) treatment. In the present study, we detected that cortactin (CTTN) played an indispensable role in matrix stiffness-induced cell migration, invasion, and invadopodia formation. Advances in cancer research have highlighted that dysregulated alternative splicing contributes to cancer progression as an oncogenic driver. However, whether WT-CTTN or splice variants (SV1-CTTN or SV2-CTTN) regulate matrix stiffness-induced malignant phenotype is largely unknown. We proved that alteration of WT-CTTN expression modulated matrix stiffness-induced cell migration, invasion, and invadopodia formation. Considering that splicing factors might drive cancer progression through positive feedback loops, we analyzed and showed how the splicing factor PTBP2 and TIA1 modulated the production of WT-CTTN. Moreover, we determined that high stiffness activated PTBP2 expression. Taken together, our findings showed that the PTBP2-WT-CTTN level increases upon stiffening and then promotes cell migration, invasion, and invadopodia formation in NPC.

Engineered Extracellular Vesicles Driven by Erythrocytes Ameliorate Bacterial Sepsis by Iron Recycling, Toxin Clearing and Inflammation Regulation.

Sepsis poses a significant challenge in clinical management. Effective strategies targeting iron restriction, toxin neutralization, and inflammation regulation are crucial in combating sepsis. However, a comprehensive approach simultaneously targeting these multiple processes has not been established. Here, an engineered apoptotic extracellular vesicles (apoEVs) derived from macrophages is developed and their potential as multifunctional agents for sepsis treatment is investigated. The extensive macrophage apoptosis in a Staphylococcus aureus-induced sepsis model is discovered, unexpectedly revealing a protective role for the host. Mechanistically, the protective effects are mediated by apoptotic macrophage-released apoEVs, which bound iron-containing proteins and neutralized α-toxin through interaction with membrane receptors (transferrin receptor and A disintegrin and metalloprotease 10). To further enhance therapeutic efficiency, apoEVs are engineered by incorporating mesoporous silica nanoparticles preloaded with anti-inflammatory agents (microRNA-146a). These engineered apoEVs can capture iron and neutralize α-toxin with their natural membrane while also regulating inflammation by releasing microRNA-146a in phagocytes. Moreover, to exploit the microcosmic movement and rotation capabilities, erythrocytes are utilized to drive the engineered apoEVs. The erythrocytes-driven engineered apoEVs demonstrate a high capacity for toxin and iron capture, ultimately providing protection against sepsis associated with high iron-loaded conditions. The findings establish a multifunctional agent that combines natural and engineered antibacterial strategies.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Chlorogenic acid enhances PPARγ-mediated lipogenesis through preventing Lipin 1 nuclear translocation in Staphylococcus aureus-exposed bovine mammary epithelial cells.

Chlorogenic acid (CGA) as one of the most ubiquitously dietary polyphenolic compounds, has been reported to have various antimicrobial effects and exhibit strong anti-inflammatory ability. Staphylococcus aureus is a gram-positive bacterium that can induce mastitis. However, the mechanism through which S. aureus infection affects lipid synthesis and whether CGA have protective effect on S. aureus reduced lipid synthesis is not fully understood. In this study, the internalization of S. aureus reduced intracellular lipid droplet formation, decreased the levels of intracellular triacylglycerol, total cholesterol and 7 types of fatty acid and downregulated the expression of lipogenic genes FAS, ACC, and DGAT1 in bovine mammary epithelial cells (BMECs). In addition, we found that S. aureus intracellular infection attenuated mTORC1 activation resulting in Lipin 1 nuclear localization. Remarkablely, S. aureus infection-mediated repression of lipid synthesis related to the mTORC1 signaling and Lipin 1 nuclear localization can be alleviated by CGA. Thus, our findings provide a novel mechanism by which lipid synthesis is regulated under S. aureus infection and the protective effects of CGA on lipid synthesis in BMECs.

SCARB1 in extracellular vesicles promotes NPC metastasis by co-regulating M1 and M2 macrophage function.

Distant metastasis is currently the main factor affecting the prognosis of nasopharyngeal carcinoma (NPC), and understanding the mechanisms of metastasis and identifying reliable therapeutic targets are critical for improving prognosis and achieving clinical translation. Macrophages, as important immune cells in the tumor microenvironment (TME), have been shown to regulate metastasis. And extracellular vesicles (EVs) secreted by stromal cells and tumor cells play the important role in intercellular communication in the tumor microenvironment. However, the role of NPC-EVs on macrophages and their function in regulating macrophages to affect metastasis has not been fully clarified. In this study, we report that NPC-EVs can be uptake by macrophages and alter macrophage polarization, for the first time, we identified the genes implicated in these regulatory functions: SCARB1, HAAO, and CYP1B1. Moreover, we found that SCARB1 was positively associated with metastasis and poor prognosis of NPC. Interestingly, we found that SCARB1-rich EVs promoted M1 macrophages ferroptosis to decrease M1 macrophages infiltration by upregulating the HAAO level while decreasing phagocytosis of M2 macrophages by upregulating the CYP1B1 level. Finally, we identified the SCARB1-binding gene KLF9, which is involved in the transcription of HAAO and CYP1B1. Our findings showed that SCARB1-EVs promoted metastasis by co-regulating M1 and M2 macrophage function. The related mechanism will provide a new therapeutic strategy to help patients with NPC improve their prognosis.

Humoral regulation of iron metabolism by extracellular vesicles drives antibacterial response.

Immediate restriction of iron initiated by the host is a critical process to protect against bacterial infections and has been described in the liver and spleen, but it remains unclear whether this response also entails a humoral mechanism that would enable systemic sequestering of iron upon infection. Here we show that upon bacterial invasion, host macrophages immediately release extracellular vesicles (EVs) that capture circulating iron-containing proteins. Mechanistically, in a sepsis model in female mice, Salmonella enterica subsp. enterica serovar Typhimurium induces endoplasmic reticulum stress in macrophages and activates inositol-requiring enzyme 1α signaling, triggering lysosomal dysfunction and thereby promoting the release of EVs, which bear multiple receptors required for iron uptake. By binding to circulating iron-containing proteins, these EVs prevent bacteria from iron acquisition, which inhibits their growth and ultimately protects against infection and related tissue damage. Our findings reveal a humoral mechanism that can promptly regulate systemic iron metabolism during bacterial infection.

SEVs-mediated miR-6750 transfer inhibits pre-metastatic niche formation in nasopharyngeal carcinoma by targeting M6PR.

Reliable detection of circulating small extracellular vesicles (SEVs) and their miRNA cargo has been needed to develop potential specific non-invasive diagnostic and therapeutic marker for cancer metastasis. Here, we detected miR-6750, the precise molecular function of which was largely unknown, was significantly enriched in serum-SEVs from normal volunteers vs. patients with nasopharyngeal carcinoma (NPC). And we determined that miR-6750-SEVs attenuated NPC metastasis. Subsequently, miR-6750-SEVs was proven to inhibit angiogenesis and activate macrophage toward to M1 phenotype to inhibit pre-metastatic niche formation. After analyzing the expression level of miR-6750 in NPC cells, HUVECs and macrophage, we found that once miR-6750 level in NPC cells was close to or higher than normal nasopharyngeal epithelial cells (NP69), miR-6750-SEVs would be transferred from NPC cells to macrophage and then to HUVECs to modulate metastatic niche. Moreover, in vitro assays and BALB/c mouse tumor models revealed that miR-6750 directly targeted mannose 6-phosphate receptor (M6PR). Taken together, our findings revealed that miR-6750-M6PR axis can mediate NPC metastasis by remodeling tumor microenvironment (TME) via SEVs, which give novel sights to pathogenesis of NPC.

Intercellular Communication Reveals Therapeutic Potential of Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer.

(1) Background: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with high intra-tumoral heterogeneity. The epithelial-mesenchymal transition (EMT) is one of the inducers of cancer metastasis and migration. However, the description of the EMT process in TNBC using single-cell RNA sequencing (scRNA-seq) remains unclear. (2) Methods: In this study, we analyzed 8938 cellular gene expression profiles from five TNBC patients. We first scored each malignant cell based on functional pathways to determine its EMT characteristics. Then, a pseudo-time trajectory analysis was employed to characterize the cell trajectories. Furthermore, CellChat was used to identify the cellular communications. (3) Results: We identified 888 epithelium-like and 846 mesenchyme-like malignant cells, respectively. A further pseudo-time trajectory analysis indicated the transition trends from epithelium-like to mesenchyme-like in malignant cells. To characterize the potential regulators of the EMT process, we identified 10 dysregulated transcription factors (TFs) between epithelium-like and mesenchyme-like malignant cells, in which overexpressed forkhead box protein A1 (FOXA1) was recognized as a poor prognosis marker of TNBC. Furthermore, we dissected the cell-cell communications via ligand-receptor (L-R) interactions. We observed that tumor-associated macrophages (TAMs) may support the invasion of malignant epithelial cells, based on CXCL-CXCR2 signaling. The tumor necrosis factor (TNF) signaling pathway secreted by TAMs was identified as an outgoing communication pattern, mediating the communications between monocytes/TAMs and malignant epithelial cells. Alternatively, the TNF-related ligand-receptor (L-R) pairs showed promising clinical implications. Some immunotherapy and anti-neoplastic drugs could interact with the L-R pairs as a potential strategy for the treatment of TNBC. In summary, this study enhances the understanding of the EMT process in the TNBC microenvironment, and dissections of EMT-related cell communications also provided us with potential treatment targets.

Protective effects of chlorogenic acid on inflammatory responses induced by Staphylococcus aureus and milk protein synthesis in bovine mammary epithelial cells.

Staphylococcus aureus (S. aureus) is a major mastitis-causing pathogen in dairy cows. Dairy cows with mastitis suffer from a decrease in milk yield and protein content. Chlorogenic acid (CGA) is a natural product with anti-inflammatory effects. In this study, we examined the function and mechanism of CGA with regard to its anti-inflammatory effects and evaluated its protective function in milk protein synthesis in bovine mammary epithelial cells (BMECs). BMECs were cultured with and without infection by S. aureus and CGA, and extracellular inflammatory cytokines and amino acids in the medium and milk proteins were determined by ELISA. The function of IL-10RA in anti-inflammatory processes and of SF-1 in milk protein synthesis was assessed by gene silencing. The activity of mTORC1, NF-κB, and STAT5 was examined by western blot. S. aureus caused intracellular infection and upregulated TNF-α, IL-1ß, IL-6, and IL-8, whereas uptake of amino acids and milk protein synthesis were suppressed. CGA mitigated the S. aureus-induced inflammatory response and milk protein synthesis in vitro and in vivo. CGA alleviated S. aureus-induced inhibition of mTORC1 and STAT5 and upregulated IL-10 and IL-10RA. In addition, SF-1 was predicted to be a transcription factor of the milk protein-encoding genes α-LA, ß-LG, and CSN2. S. aureus downregulated SF-1 and CGA reversed the decline in milk protein synthesis due to SF-1 knockdown. Thus, CGA mitigates the inflammatory response that is induced by S. aureus and protects the uptake of amino acids and milk protein synthesis in BMECs.

SMYD2 targets RIPK1 and restricts TNF-induced apoptosis and necroptosis to support colon tumor growth.

SMYD2 is a histone methyltransferase, which methylates both histone H3K4 as well as a number of non-histone proteins. Dysregulation of SMYD2 has been associated with several diseases including cancer. In the present study, we investigated whether and how SMYD2 might contribute to colorectal cancer. Increased expression levels of SMYD2 were detected in human and murine colon tumor tissues compared to tumor-free tissues. SMYD2 deficiency in colonic tumor cells strongly decreased tumor growth in two independent experimental cancer models. On a molecular level, SMYD2 deficiency sensitized colonic tumor cells to TNF-induced apoptosis and necroptosis without affecting cell proliferation. Moreover, we found that SMYD2 targeted RIPK1 and inhibited the phosphorylation of RIPK1. Finally, in a translational approach, pharmacological inhibition of SMYD2 attenuated colonic tumor growth. Collectively, our data show that SMYD2 is crucial for colon tumor growth and inhibits TNF-induced apoptosis and necroptosis.

Multi-Source Transfer Learning Via Multi-Kernel Support Vector Machine Plus for B-Mode Ultrasound-Based Computer-Aided Diagnosis of Liver Cancers.

B-mode ultrasound (BUS) imaging is a routine tool for diagnosis of liver cancers, while contrast-enhanced ultrasound (CEUS) provides additional information to BUS on the local tissue vascularization and perfusion to promote diagnostic accuracy. In this work, we propose to improve the BUS-based computer aided diagnosis for liver cancers by transferring knowledge from the multi-view CEUS images, including the arterial phase, portal venous phase, and delayed phase, respectively. To make full use of the shared labels of paired of BUS and CEUS images to guide knowledge transfer, support vector machine plus (SVM+), a specifically designed transfer learning (TL) classifier for paired data with shared labels, is adopted for this supervised TL. A nonparallel hyperplane based SVM+ (NHSVM+) is first proposed to improve the TL performance by transferring the per-class knowledge from source domain to the corresponding target domain. Moreover, to handle the issue of multi-source TL, a multi-kernel learning based NHSVM+ (MKL-NHSVM+) algorithm is further developed to effectively transfer multi-source knowledge from multi-view CEUS images. The experimental results indicate that the proposed MKL-NHSVM+ outperforms all the compared algorithms for diagnosis of liver cancers, whose mean classification accuracy, sensitivity, and specificity are 88.18 ± 3.16 %, 86.98 ± 4.77 %, and 89.42±3.77%, respectively.

Exosomal MIF Derived From Nasopharyngeal Carcinoma Promotes Metastasis by Repressing Ferroptosis of Macrophages.

Nasopharyngeal carcinoma (NPC) is the most common malignant tumor of the head and neck cancer (HNC). Metastasis is the main cause of treatment failure. However, the molecular mechanism for NPC metastasis is still unclear. As one of the most common host immune cells in the tumor microenvironment, macrophages have been proven to regulate metastasis. Besides, exosomes are the important bridge connecting various cells in TME. Currently, the role of NPC-exos on macrophages and their impact on metastasis remains to be unexplored. In this study, we found that MIF was highly expressed in NPC cells, and the exosomes secreted by NPC cells could be taken up by macrophages, thereby, inhibiting the ferroptosis of macrophages and then promoting the metastasis of NPC. Targeting MIF may be a potential treatment to reduce the rate of metastasis.

Oncogenic State and Cell Identity Combinatorially Dictate the Susceptibility of Cells within Glioma Development Hierarchy to IGF1R Targeting.

Glioblastoma is the most malignant cancer in the brain and currently incurable. It is urgent to identify effective targets for this lethal disease. Inhibition of such targets should suppress the growth of cancer cells and, ideally also precancerous cells for early prevention, but minimally affect their normal counterparts. Using genetic mouse models with neural stem cells (NSCs) or oligodendrocyte precursor cells (OPCs) as the cells-of-origin/mutation, it is shown that the susceptibility of cells within the development hierarchy of glioma to the knockout of insulin-like growth factor I receptor (IGF1R) is determined not only by their oncogenic states, but also by their cell identities/states. Knockout of IGF1R selectively disrupts the growth of mutant and transformed, but not normal OPCs, or NSCs. The desirable outcome of IGF1R knockout on cell growth requires the mutant cells to commit to the OPC identity regardless of its development hierarchical status. At the molecular level, oncogenic mutations reprogram the cellular network of OPCs and force them to depend more on IGF1R for their growth. A new-generation brain-penetrable, orally available IGF1R inhibitor harnessing tumor OPCs in the brain is also developed. The findings reveal the cellular window of IGF1R targeting and establish IGF1R as an effective target for the prevention and treatment of glioblastoma.

Exosomes released from educated mesenchymal stem cells accelerate cutaneous wound healing via promoting angiogenesis.

OBJECTIVES: Skin serves as the major interface between the external environment and body which is liable to many kinds of injuries. Mesenchymal stem cell (MSC) therapy has been widely used and became a promising strategy. Pre-treatment with chemical agents, hypoxia or gene modifications can partially protect MSCs against injury, and the pre-treated MSCs show the improved differentiation, homing capacity, survival and paracrine effects regard to attenuating injury. The aim of this study was to investigate whether the exosomes from the educated MSCs contribute to accelerate wound healing process. MATERIALS AND METHODS: We extracted the exosomes from the two educated MSCs and utilized them in the cutaneous wound healing model. The pro-angiogenetic effect of exosomes on endothelial cells was also investigated. RESULTS: We firstly found that MSCs pre-treated by exosomes from neonatal serum significantly improved their biological functions and the effect of therapy. Moreover, we extracted the exosomes from the educated MSCs and utilized them to treat the cutaneous wound model directly. We found that the released exosomes from MSCs which educated by neonatal serum before had the more outstanding performance in therapeutic effect. Mechanistically, we revealed that the recipient endothelial cells (ECs) were targeted and the exosomes promoted their functions to enhance angiogenesis via regulating AKT/eNOS pathway. CONCLUSIONS: Our findings unravelled the positive effect of the upgraded exosomes from the educated MSCs as a promising cell-free therapeutic strategy for cutaneous wound healing.

Epithelial-mesenchymal transition and metastasis of colon cancer cells induced by the FAK pathway in cancer-associated fibroblasts.

OBJECTIVE: The role and mechanism of tetrathiomolybdate (TM) in cancer-associated fibroblasts (CAFs) in colon cancer using three-dimensional (3D) culture were investigated, and the associations between the focal adhesion kinase (FAK) pathway and epithelial-mesenchymal transition (EMT) in CAFs were explored. METHODS: A 3D co-culture model of colon cancer LOVO cells with CAFs and normal fibroblasts (NFs) was established using Matrigel as a scaffold material. The differential expression of LOXL2 (lysyl oxidase-like 2) in the supernatant of CAFs and NFs was determined using ELISA, and expression levels of EMT-related proteins and FAK signaling pathway-related proteins were determined using western blot. RESULTS: LOXL2 levels secreted by CAFs were higher compared with that secreted by NFs. In the CAF + LOVO group, compared with the LOVO group, E-cadherin expression decreased significantly, while N-cadherin and F-PAK expression increased significantly. TM results were opposite compared with the above results. CONCLUSIONS: CAFs stimulate EMT in human colon cancer LOVO cells by secreting LOXL2 to activate the FAK signaling pathway, thereby promoting tumor metastasis. TM inhibited the occurrence of EMT in the CAF-induced colon cancer LOVO cell line, thereby reducing the invasion and metastasis of colon cancer cells.

Donor MSCs release apoptotic bodies to improve myocardial infarction via autophagy regulation in recipient cells.

Mesenchymal stem cell (MSC) transplantation has been widely applied as a potential therapeutic for multiple diseases. However, the underlying therapeutic mechanisms are not fully understood, especially the paradox between the low survival rate of transplanted cells and the beneficial therapeutic effects generated by these cells. Herein, in a myocardial infarction (MI) model, we found that transplanted MSCs released apoptotic bodies (ABs) to enhance angiogenesis and improve cardiac functional reclovery via regulating macroautophagy/autophagy in the recipient endothelial cells (ECs). Mechanistically, after local transplantation, MSCs underwent extensive apoptosis in the short term and released ABs, which were engulfed by the recipient ECs. Then, in the ECs, ABs activated lysosome functions and promoted the expression of TFEB (transcription factor EB), which is a master gene in lysosomal biogenesis and autophagy. Finally, the increase in TFEB enhanced autophagy-related gene expression in ECs and promoted angiogenesis and cardiac functional recovery after MI. Collectively, we found that apoptotic donor MSCs promote angiogenesis via regulating autophagy in the recipient ECs, unveiling the role of donor cell apoptosis in the therapeutic effects generated by cell transplantation. Abbreviations: 3-MA: 3-methyladenine; ABs: apoptotic bodies; BECN1: beclin 1; CASP3: caspase 3; CQ: chloroquine; ECs: endothelial cells; EVs: extracellular vesicles; LAMP1: lysosomal-associated membrane protein 1; LVEF: left ventricular ejection fraction; LVFS: left ventricular fractional shortening; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MI: myocardial infarction; MSC: mesenchymal stem cell; NO: nitric oxide; TFEB: transcription factor EB; TUNEL: TdT-mediated dUTP Nick-End Labeling.

Exosomal miR-17-5p promotes angiogenesis in nasopharyngeal carcinoma via targeting BAMBI.

Objective: The purpose of our study is to investigate the role of miR-17-5p in angiogenesis of nasopharyngeal carcinoma and the crosstalk between HUVECs and CNE-2 via exosomes. Methods: Firstly, flow cytometry, cell viability assay, transwell assay, and tube formation were used to explore the role of miR-17-5p in angiogenesis. Then zebrafish model was used to confirm effects of miR-17-5p on angiogenesis. qRT-PCR analysis and Immunofluorescence assay were used to explore the expression of miR-17-5p in NPC tissues and cells compared to the normal control. Besides, in vitro assays were used to analyze the biological functions of miR-17-5p in NPC. What's more, in vitro and in vivo assays were used to detect the function of exosomal miR-17-5p in angiogenesis. Finally, luciferase reporter assay and western bolt were used to determine the relationship between miR-17-5p and BAMBI. Results: We observed that high expression of miR-17-5p promoted angiogenesis in NPC. Also, high expression of miR-17-5p promoted the NPC cells proliferation and migration. To know whether there's any communication between HUVECs and NPC cells, exosomes derived from CNE-2 cells were collected. Further results showed that exosomal miR-17-5p secreted from NPC promoted the angiogenesis. What's more, in vitro assays revealed that miR-17-5p targets BAMBI and regulates AKT/VEGF-A signaling. Conclusions: Our study showed that exosomal miR-17-5p derived from NPC cells promotes angiogenesis via targeting BAMBI and regulates AKT/VEGF-A signaling.