Angiogenesis is a complicated and sequential process that plays an important role in different physiological processes. Mesenchymal stem cells (MSCs), which are pluripotent stem cells, are widely used for the treatment of ischemic and traumatic diseases, and exosomes derived from these cells can also promote angiogenesis. Therefore, we aimed to uncover mechanisms to improve MSC exosome-mediated angiogenesis. For this study, we isolated human adipose-derived MSCs (hAD-MSCs) and assessed differentiation ability and markers. Cells were divided into hypoxia-treated MSCs (H-MSCs) and normoxia-treated MSCs (N-MSC), and exosomes were extracted by ultrafiltration. Exosomes (100 μg/mL) from H-MSCs and N-MSCs were added to human umbilical vein endothelial cells (HUVECs). Exosome uptake and the ability of endothelial cells to form tubes were detected in real time. Protein samples were collected at different time points to detect the expression of inhibitors (Vash1) and enhancers (Angpt1 and Flk1) of angiogenesis; we also assessed their related signaling pathways. We found that exosomes from the hypoxia group were more easily taken up by HUVECs; furthermore, their angiogenesis stimulatory activity was also significantly enhanced compared to that with exosomes from the normoxia group. HUVECs exposed to exosomes from H-MSCs significantly upregulated angiogenesis-stimulating genes and deregulated angiogenesis-inhibitory genes. The expression of vascular endothelial growth factor (VEGF) and activation of the protein kinase A (PKA) signaling pathway in HUVECs were significantly increased by hypoxia-exposed exosomes. Moreover, a PKA inhibitor was shown to significantly suppress angiogenesis. Finally, we concluded that hypoxia-exposed exosomes derived from hAD-MSCs can improve angiogenesis by activating the PKA signaling pathway and promoting the expression of VEGF. These results could be used to uncover safe and effective treatments for traumatic diseases.

AimsInsufficient sleep has been found to result in varying degrees of cognitive impairment and emotional changes. Sleep was reported probably responsible for cleaning metabolic wastes in brain by increasing extracellular bulk flow. Herein, we propose that chronic sleep insufficiency in young adult wild‐type mice is also linked with dysfunction of intracellular protein degradation pathways and microglia‐mediated neuroinflammation, which are potentially important mechanisms in the initiation of neurodegeneration.MethodsWe applied the chronic sleep fragmentation (CSF) model to induce chronic sleep insufficiency in wild‐type mice. After 2 months of CSF, cognitive function, amyloid‐β accumulation, dysfunction of endosome‐autophagosome‐lysosome pathway, and microglia activation were evaluated.ResultsFollowing CSF, impairment of spatial learning and memory, and aggravated anxiety‐like behavior in mice were identified by behavioral experiments. Increased intracellular amyloid‐β accumulation was observed in cortex and hippocampus. Mechanistically, CSF could significantly enhance the expression of Rab5 (early endosome marker), Rab7 (late endosome marker), as well as LC3B (autophagosome marker), and autophagy‐positive regulatory factors in brain detected by immunofluorescent staining and Western blot. In addition, activation of microglia was evident by enhanced CD68, CD16/32, and CD206 levels after CSF treatment.ConclusionsChronic sleep fragmentation could initiate pathogenetic processes similar to the early stage of neurodegeneration, including dysfunction of endosome‐autophagosome‐lysosome pathway and microglia‐mediated neuroinflammation. Our findings further strengthen the link between chronic sleep insufficiency and the initiation of neurodegeneration even if lack of genetic predisposition.

The Wnt/β-catenin pathway has important roles in chemoresistance and multidrug resistance 1 (MDR1) expression in some cancers, but its involvement in breast cancer and the underlying molecular mechanism are undefined. In this study, we demonstrated that the Wnt/β-catenin pathway is activated in chemoresistant breast cancer cells. Using a Wnt pathway-specific PCR array screening assay, we detected that Pygo2, a newly identified Wnt/β-catenin pathway component, was the most upregulated gene in the resistant cells. Additional experiments indicated that Pygo2 activated MDR1 expression in the resistant cells via the Wnt/β-catenin pathway. Moreover, the inhibition of Pygo2 expression restored the chemotherapeutic drug sensitivity of the resistant cells and reduced the breast cancer stem cell population in these cells in response to chemotherapy. Importantly, these activities induced by Pygo2 were mediated by MDR1. We also determined the effect of Pygo2 on the sensitivity of breast tumors resistant to doxorubicin in a mouse model. Finally, RNA samples from 64 paired patient tumors (before and after chemotherapy) highly and significantly overexpressed Pygo2 and/or MDR1 after treatment, thus underlining a pivotal role for the Pygo2-mediated Wnt/β-catenin pathway in the clinical chemoresistance of breast cancer. Our data represent the first implication of the Wnt/β-catenin pathway in breast cancer chemoresistance and identify potential new targets to treat the recurrence of breast cancer.

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Mounting evidences indicated that long non-coding RNA is dysregulated and involved in the pathology of tumors. However, the role of lncRNAs in colorectal cancer (CRC) progression is not fully determined. Differentially expressed lncRNA profile in CRC was conducted by lncRNA microarray in 15 pairs of CRC tissues and adjacent normal tissues, and validated by real-time PCR analysis in another 106 pairs of tissues. The biological effect of lncRNA ZNFX1-AS1 was evaluated by in vitro and in vivo assays. The regulation between lncRNA ZNFX1-AS1 and miR-144 was evaluated by a series of experiments. We found that lncRNA ZNFX1-AS1 expression was significantly upregulated in CRC tissues and cell lines, and the expression of lncRNA ZNFX1-AS1 was associated with aggressive tumor phenotype and poor prognosis in CRC. Functionally, knockdown of lncRNA ZNFX1-AS1 inhibited cell proliferation, invasion, in vitro and tumorigenesis and metastasis in vivo. Further investigation demonstrated that lncRNA ZNFX1-AS1 functioned as a competing endogenous RNA (ceRNA) for miR-144, thereby leading to the depression of its endogenous target gene Polycomb group protein enhancer of zeste homolog 2 (EZH2). We found that lncRNA ZNFX1-AS1 is significantly upregulated in CRC, and the newly identified lncRNA ZNFX1-AS1-miR-144-EZH2 axis is involved in the regulation of CRC progression, which might be used as potential therapeutic targets for CRC patients.

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Immune checkpoint blockade (ICB) therapy has attracted widespread attention in cancer treatment. Due to the low immunogenicity and immune suppression state in the tumor microenvironment (TME), the therapeutic effects are only moderate. Herein, a TME-activable manganese-boosted catalytic immunotherapy is designed for synergism with ICB therapy to kill tumors efficiently. The tumor cell membrane (CM)-wrapping multienzyme-mimic manganese oxide (MnO x ) nanozyme termed CM@Mn showed intrinsic peroxidase and oxidase-like activities in an acidic TME. These activities can generate toxic hydroxyl (•OH) and superoxide radicals (•O2 –) for tumor cell killing and evoking immunogenic cell death (ICD). Furthermore, the TME-responsive release of Mn2+ directly promotes dendritic cell maturation and macrophage M1 repolarization, resulting in the reversal of an immunosuppressive TME into an immune-activating environment. Additionally, tumor hypoxia relief caused by catalase-like activity also contributes to the process of TME reversal. Finally, a robust tumor-specific T cell-mediated antitumor response occurs with the support of the PD-1 checkpoint blockade. The proliferation of primary and metastatic tumors was inhibited, and a long-term immune memory effect was induced. The therapeutic strategy outlined here may serve as a promising candidate for tumor-integrated treatment.

BackgroundIncreased production of matrix metalloproteinases (MMPs) is closely related to the progression of osteoarthritis (OA). The present study was performed to investigate the potential value of biochanin A in inhibition of MMP expression in both rabbit chondrocytes and an animal model of OA.MethodsMTT assay was performed to assess chondrocyte survival in monolayers. The mRNA and protein expression of MMPs (including MMP-1, MMP-3, and MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in interleukin-1 < beta > (IL-1β)-induced rabbit chondrocytes were determined by quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The involvement of the NF-kappaB (NF-κB) pathway activated by IL-1β was determined by western blotting. The in vivo effects of biochanin A were evaluated by intra-articular injection in an experimental OA rabbit model induced by anterior cruciate ligament transection (ACLT).ResultsBiochanin A downregulated the expression of MMPs and upregulated TIMP-1 at both the mRNA and protein levels in IL-1β-induced chondrocytes in a dose-dependent manner. In addition, IL-1β-induced activation of NF-κB was attenuated by biochanin A, as determined by western blotting. Moreover, biochanin A decreased cartilage degradation as determined by both morphological and histological analyses in vivo.ConclusionsTaken together, these findings suggest that biochanin A may be a useful agent in the treatment and prevention of OA.