Glioblastoma is an aggressive tumor that is associated with distinctive infiltrating microglia/macrophages populations. Previous studies demonstrated that chlorogenic acid (5-caffeoylquinic acid, CHA), a phenolic compound with low molecular weight, has an anti-tumor effect in multiple malignant tumors. In the present study, we focused on the macrophage polarization to investigate the molecular mechanisms behind the anti-glioma response of CHA in vitro and in vivo. We found that CHA treatment increased the expression of M1 markers induced by LPS/IFNγ, including iNOS, MHC II (I-A/I-E subregions) and CD11c, and reduced the expression of M2 markers Arg and CD206 induced by IL-4, resulting in promoting the production of apoptotic-like cancer cells and inhibiting the growth of tumor cells by co-culture experiments. The activations of STAT1 and STAT6, which are two crucial signaling events in M1 and M2-polarization, were significantly promoted and suppressed by CHA in macrophages, respectively. Furthermore, In G422 xenograft mice, CHA increased the proportion of CD11c-positive M1 macrophages and decreased the distribution of CD206-positive M2 macrophages in tumor tissue, consistent with the reduction of tumor weight observed in CHA-treated mice. Overall these findings indicated CHA as a potential therapeutic approach to reduce glioma growth through promoting M1-polarized macrophage and inhibiting M2 phenotypic macrophage.
Precise gene editing is—or will soon be—in clinical use for several diseases, and more applications are under development. The programmable nuclease Cas9, directed by a single-guide RNA (sgRNA), can introduce double-strand breaks (DSBs) in target sites of genomic DNA, which constitutes the initial step of gene editing using this novel technology. In mammals, two pathways dominate the repair of the DSBs—nonhomologous end joining (NHEJ) and homology-directed repair (HDR)—and the outcome of gene editing mainly depends on the choice between these two repair pathways. Although HDR is attractive for its high fidelity, the choice of repair pathway is biased in a biological context. Mammalian cells preferentially employ NHEJ over HDR through several mechanisms: NHEJ is active throughout the cell cycle, whereas HDR is restricted to S/G2 phases; NHEJ is faster than HDR; and NHEJ suppresses the HDR process. This suggests that definitive control of outcome of the programmed DNA lesioning could be achieved through manipulating the choice of cellular repair pathway. In this review, we summarize the DSB repair pathways, the mechanisms involved in choice selection based on DNA resection, and make progress in the research investigating strategies that favor Cas9-mediated HDR based on the manipulation of repair pathway choice to increase the frequency of HDR in mammalian cells. The remaining problems in improving HDR efficiency are also discussed. This review should facilitate the development of CRISPR/Cas9 technology to achieve more precise gene editing.
The perception of herbivory by plants is known to be triggered by the deposition of insect-derived factors such as saliva and oral secretions, oviposition materials, and even feces. Such insect-derived materials harbor chemical cues that may elicit herbivore and/or pathogen-induced defenses in plants. Several insect-derived molecules that trigger herbivore-induced defenses in plants are known; however, insect-derived molecules suppressing them are largely unknown. In this study, we identified two plant chitinases from fall armyworm (Spodoptera frugiperda) larval frass that suppress herbivore defenses while simultaneously inducing pathogen defenses in maize (Zea mays). Fall armyworm larvae feed in enclosed whorls of maize plants, where frass accumulates over extended periods of time in close proximity to damaged leaf tissue. Our study shows that maize chitinases, Pr4 and Endochitinase A, are induced during herbivory and subsequently deposited on the host with the feces. These plant chitinases mediate the suppression of herbivore-induced defenses, thereby increasing the performance of the insect on the host. Pr4 and Endochitinase A also trigger the antagonistic pathogen defense pathway in maize and suppress fungal pathogen growth on maize leaves. Frass-induced suppression of herbivore defenses by deposition of the plant-derived chitinases Pr4 and Endochitinase A is a unique way an insect can co-opt the plant's defense proteins for its own benefit. It is also a phenomenon unlike the induction of herbivore defenses by insect oral secretions in most host-herbivore systems.
Vascular calcification is a risk predictor and common pathological change in cardiovascular diseases that are associated with elastin degradation and phenotypic transformation of vascular smooth muscle cells via gelatinase matrix metalloproteinase-2 (MMP2). However, the mechanisms involved in this process remain unclear. In this study, we investigated the relationships between miR-29b-3p and MMP2, to confirm miR-29b-3p-mediated MMP2 expression at the posttranscriptional level in arterial calcification. In male Sprague Dawley rats, arterial calcification was induced by subcutaneous injection of a toxic dose of cholecalciferol. In vivo, the quantitative real-time polymerase chain reaction (qRT-PCR) showed that MMP2 expression was upregulated in calcified arterial tissues, and miR-29b-3p expression was downregulated. There was a negative correlation between MMP2 mRNA expression and miR-29b-3p levels (P = 0.0014, R2 = 0.481). Western blotting showed that MMP2 expression was significantly increased in rats treated with cholecalciferol. In vitro, overexpression of miR-29b-3p led to decreased MMP2 expression in rat vascular smooth muscle cells, while downregulation of miR-29b-3p expression led to increased MMP2 expression. Moreover, the luciferase reporter assay confirmed that MMP2 is the direct target of miR-29b-3p. Together, our results demonstrated that a role of miR-29b-3p in vascular calcification involves targeting MMP2.
Objective— Osteoprotegerin (OPG) is a decoy receptor for the osteoclast differentiation factor receptor activator of NF-κB ligand. OPG regulates bone homeostasis, and its inactivation in mice results in severe osteoporosis. OPG deficiency in apolipoprotein E (ApoE) −/− mice results in increased atherosclerotic lesion size and calcification. Furthermore, receptor activator of NF-κB ligand enhances macrophage-dependent smooth muscle cell calcification in vitro. Here, we hypothesized that reconstitution of ApoE −/− OPG −/− mice with ApoE −/− OPG +/+ bone marrow (BM) would be sufficient to rescue lesion progression and vascular calcification. Conversely, reconstitution of ApoE −/− OPG +/+ mice with ApoE −/− OPG −/− BM may accelerate lesion progression and vascular calcification. Approach and Results— ApoE −/− OPG −/− mice transplanted with ApoE −/− OPG +/+ BM developed smaller atherosclerotic lesions and deposited less calcium in the innominate artery than that of ApoE −/− OPG −/− mice transplanted with ApoE −/− OPG −/− BM. There were no differences in lesion size and calcification in ApoE −/− OPG +/+ mice transplanted with BM from ApoE −/− OPG −/− or ApoE −/− OPG +/+ mice. The large lesions observed in the ApoE −/− OPG −/− mice transplanted with OPG −/− BM were rich in chondrocyte-like cells, collagen, and proteoglycans. Importantly, the ApoE −/− OPG −/− mice transplanted with OPG +/+ BM remained osteoporotic, and the ApoE −/− OPG +/+ mice did not show signs of bone loss regardless of the type of BM received. In coculture experiments, macrophages and mesenchymal stem cells derived from ApoE −/− OPG −/− BM induced more vascular smooth muscle cell calcification than cells derived from ApoE −/− OPG +/+ mice. Conclusions— These results indicate that OPG derived either from the BM or from the vessel wall is sufficient to slow down lesion progression and vascular calcification independent of bone turnover.
Protein delivery with cell-penetrating peptide is opening up the possibility of using targets inside cells for therapeutic or biological applications; however, cell-penetrating peptide-mediated protein delivery commonly suffers from ineffective endosomal escape and low tolerance in serum, thereby limiting in vivo efficacy. Here, we present an intracellular protein delivery system consisting of four modules in series: cell-penetrating peptide, pH-dependent membrane active peptide, endosome-specific protease sites and a leucine zipper. This system exhibits enhanced delivery efficiency and serum tolerance, depending on proteolytic cleavage-facilitated endosomal escape and leucine zipper-based dimerisation. Intravenous injection of protein phosphatase 1B fused with this system successfully suppresses the tumour necrosis factor-α-induced systemic inflammatory response and acetaminophen-induced acute liver failure in a mouse model. We believe that the strategy of using multifunctional chimaeric peptides is valuable for the development of cell-penetrating peptide-based protein delivery systems, and facilitate the development of biological macromolecular drugs for use against intracellular targets.
Ammonium transporters (AMTs) are plasma membrane proteins that exclusively transport ammonium/ammonia. These proteins are encoded by an ancient gene family with many members. The molecular characteristics and evolutionary history of AMTs in woody plants are still poorly understood. We comprehensively evaluated the AMT gene family in the latest release of the Populus trichocarpa genome (version 3.0; Phytozome 9.0), and identified 16 AMT genes. These genes formed four clusters; AMT1 (7 genes), AMT2 (2 genes), AMT3 (2 genes), and AMT4 (5 genes). Evolutionary analyses suggested that the Populus AMT gene family has expanded via whole-genome duplication events. Among the 16 AMT genes, 15 genes are located on 11 chromosomes of Populus. Expression analyses showed that 14 AMT genes were vegetative organs expressed; AMT1;1/1;3/1;6/3;2 and AMT1;1/1;2/2;2/3;1 had high transcript accumulation level in the leaves and roots, respectively and strongly changes under the nitrogen-dependent experiments. The results imply the functional roles of AMT genes in ammonium absorption in poplar.
Background:We have previously demonstrated that overexpression of ankyrin repeat-rich membrane spanning (ARMS) protein facilitates melanoma formation via conferring apoptotic resistance. This study aims to investigate whether ARMS contributes to melanoma progression.Method:Using immunohistochemistry, we graded the expression level of ARMS in 54 cases of primary melanoma and 46 cases of metastatic melanoma. The immunointensity of ARMS was statistically correlated with individual clinicopathological characteristics. By RNA interference, stable melanoma cell clones with ARMS-knockdown were constructed, and were used for in vitro scratch wound, transwell invasion assays, and in vivo lung metastasis experiment.Results:Stronger immunointensity of ARMS was observed mostly in melanomas with Breslow tumour thickness >1.0 mm (Fisher's exact test, P=0.002) or with nodal metastasis (Fisher's exact test, P=0.026), and was correlated with a worse overall survival in melanoma patients (log-rank test, P=0.04). Depletion of ARMS inhibited migration, invasion, and metastatic potential of melanoma cells in vitro and in vivo. Moreover, ARMS mediated melanoma cell migration and invasion through activation of the extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signalling pathway.Conclusion:Ankyrin repeat-rich membrane spanning expression, conjunctly with tumour thickness or ulceration, may serve as a prognostic factor in patients with cutaneous melanoma.
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