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Neuroinflammation is associated with many neurodegenerative diseases. Abnormal activation of microglial cells in the central nervous system (CNS) is a major characteristic of neuroinflammation. Nitric oxide (NO) free radicals are produced by activated microglia and prolonged presence of large quantities of NO in the CNS can lead to neuroinflammation and disease. Hispidin is a polyphenol derived from Phellinus linteus (a valuable medicinal mushroom) with strong antioxidant, anticancer and antidiabetic properties. A previous study demonstrated that hispidin significantly inhibited NO production via lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Therefore, the present study used MTT assay was used to detect the effect of hispdin on cell viability. Griess reagent analysis was used to measure NO production. Reverse transcription-semi quantitative PCR and western blotting were used to evaluate the effects of hispdin on iNOS mRNA and MAPK/ERK/JNK protein levels. Fluorescence microscopy and flow cytometry were used to detect the effects of hispdin on the production of ROS and phagocytosis of cells. The present results indicated that hispidin could significantly inhibit the increase of NO production and iNOS expression in BV-2 microglial cells stimulated by LPS. The inhibitory effect of hispidin on NO production was similar to that of S-methylisothiourea sulfate, an iNOS inhibitor. Signaling studies demonstrated that hispidin markedly suppresses LPS-induced mitogen activated protein kinases and JAK1/STAT3 activation, although not the NF-κB signaling pathway. The present observations in LPS-stimulated BV-2 microglial cells indicated that hispidin might serve as a therapeutic candidate for the treatment of NO-induced neuroinflammation and, potentially, as a novel iNOS inhibitor.

Hepatocellular carcinoma (HCC) is highly resistant to chemotherapy. Previously, we have shown that Aurora-A mRNA is upregulated in HCC cells or tissues and silencing of Aurora-A using small interfering RNA (siRNA) decreases growth and enhances apoptosis in HCC cells. However, the clinical significance of Aurora-A protein expression in HCC and association between Aurora-A expression and HCC chemoresistance is unclear. Here, we showed that Aurora-A protein is upregulated in HCC tissues and significantly correlated with recurrence-free and overall survival of patients and multivariate analysis indicated that immunostaining of Aurora-A will be an independent prognostic factor for patients. Silencing of Aurora-A significantly increased the chemosensitivity of HCC cells both in vitro and in vivo, while overexpression of Aurora-A induced the opposite effects. Furthermore, overexpression of Aurora-A reduces chemotherapy-induced apoptosis by promoting microRNA-21 expression, which negatively regulates PTEN and then inhibits caspase-3-mediated apoptosis induction. Mechanically, we demonstrated that Aurora-A promotes expression of nuclear Ikappaβ-alpha (Iκβα) protein and enhances NF-kappa B (NF-κB) activity, thus promotes the transcription of miR-21. This study first reported the involvement of Aurora-A/NF-κB/miR-21/PTEN/Akt signaling axis in chemoresistance of HCC cells, suggesting that targeting this signaling pathway would be helpful as a therapeutic strategy for the reversal of chemoresistance in HCC.

Epithelial-mesenchymal transition (EMT) has been reported to play a significant role in tumour metastasis as well as chemoresistance. However, the molecular mechanisms involved in chemotherapy-induced EMT are still unclear. MicroRNA (miRNA) expression and functions have been reported to contribute to phenotypic features of tumour cells. To investigate the roles of miRNAs in chemotherapy-induced EMT, we established two docetaxel-resistant lung adenocarcinoma (LAD) cell models (SPC-A1/DTX and H1299/DTX), which display EMT-like properties and gain increased invasion or migration activity. MiR-451 was found to be significantly downregulated in docetaxel-resistant LAD cells, and re-expression of miR-451 could reverse EMT to mesenchymal-epithelial transition (MET) and inhibit invasion and metastasis of docetaxel-resistant LAD cells both in vitro and in vivo. The proto-oncogene c-Myc was identified as a direct and functional target of miR-451, and further researches confirmed that overexpression of c-Myc which induced extracellular-signal-regulated kinase (ERK)-dependent glycogen synthase kinase-3 beta (GSK-3β) inactivation and subsequent snail activation is essential for acquisition of EMT phenotype induced by loss of miR-451. Furthermore, c-Myc was significantly upregulated in docetaxel-non-responding LAD tissues in comparison with docetaxel-responding tissues, and its expression was inversely correlated with miR-451 expression. This study first reported the involvement of miR-451/c-Myc/ERK/GSK-3β signalling axis in the acquisition of EMT phenotype in docetaxel-resistant LAD cells, suggesting that re-expression of miR-451 or targeting c-Myc will be a potential strategy for the treatment of chemoresistant LAD patients.

Chemoresistance is one of the most significant obstacles in lung adenocarcinoma (LAD) treatment, and this process involves genetic and epigenetic dysregulation of chemoresistance-related genes. Previously, we have shown that restoration of microRNA (miR)-200b significantly reverses chemoresistance of human LAD cells by targeting E2F3. However, the molecular mechanisms involved in the silencing of miR-200b are still unclear. Here we showed that histone deacetylase (HDAC) inhibitors could restore the expression of miR-200b and reverse chemoresistant phenotypes of docetaxel-resistant LAD cells. HDAC1/4 repression significantly increased miR-200b expression by upregulating histone-H3 acetylation level at the two miR-200b promoters partially via a Sp1-dependent pathway. Furthermore, silencing of HDAC1/4 suppressed cell proliferation, promoted cell apoptosis, induced G2/M cell cycle arrest and ultimately reversed in vitro and in vivo chemoresistance of docetaxel-resistant LAD cells, at least partially in a miR-200b-dependent manner. HDAC1/4 suppression-induced rescue of miR-200b contributed to downregulation of E2F3, survivin and Aurora-A, and upregulation of cleaved-caspase-3. HDAC1/4 levels in docetaxel-insensitive human LAD tissues, inversely correlated with miR-200b, were upregulated compared with docetaxel-sensitive tissues. Taken together, our findings suggest that the HDAC1/4/Sp1/miR-200b/E2F3 pathway is responsible for chemoresistance of docetaxel-resistant LAD cells.

Stamen development and microsporogenesis of four species from Magnoliaceae was investigated in order to provide additional data from this family. Stamen bases were found to be wide and short, without morphological differentiation in Magnolia moto, M. paenetalauma and Woonyoungia septentrionalis. In contrast, stamens are distinctly differentiated into anther and filament regions in Michelia crassipes. The orientation of dehiscence is introrse, introrse-latrorse and latrorse in M. moto, M. paenetalauma and M. crassipes, respectively. The vascular bundles range from three to five (M. moto, M. paenetalauma) to one (M. crassipes). The amount of the connective tissue has been reduced from three to two times of the sporogenous tissue in M. moto and M. paenetalauma. The two parts are nearly equal in M. crassipess. In W. septentrionalis, the orientation of dehiscence, the vascular bundles and the size of the connective tissue vary in different parts of the floral receptacle. The endothecium and endothecial-like cells form a ring that encloses the entire anther. The middle layer cells originate from both the outer and inner secondary parietal layers, and start to degenerate gradually at the microspore interphase stage or meiosis stage. The tapetum is of the secretory type, derived from the inner secondary parietal cells. The mature anther wall is composed of one epidermal, one endothecial, three to four middle layer(s) and one glandular tapetum. Only one epidermis, one endothecium, and the remnants of the middle layer and tapetum are left before anther dehiscence. Microspore tetrads appear as isobilateral, tetrahedral, decussate and T-shaped, produced by a modified simultaneous microsporogenesis, which have evolved from the common ancestor of all Magnoliaceae. Our results support an ancestral state with stamens with non-marginal sporangia and the amount of sterile tissue exceeding the amount of sporogenous tissue, and evolutionary trends toward equalization of the amount of fertile and sterile tissue on the stamen.

Calcium-calmodulin-dependent protein kinase II (CaMKII) is one of the main protein kinases mediating intracellular Ca changes. It is also involved in the process of cardiac diseases, such as cardiac hypertrophy, but its effects on myocardial fibrosis remain unclear. The present study investigates whether CaMKII is involved in cardiac fibroblast proliferation and extracellular matrix (ECM) secretion induced by angiotensin II (AngII) or electrical field stimulation (EFS) in cultured neonatal rat cardiac fibroblasts. Cardiac fibroblast proliferation was assessed by a cell survival assay (MTT) and manual cell enumeration. Cellular matrix production was demonstrated by matrix metalloproteinases (MMP) 1, 2, 9, and collagen I/III messenger RNA expression, MMP-2, 9 protein expression, and secretion of transforming growth factor beta1 and tumor necrosis factor alpha. Either AngII or EFS promoted cardiac fibroblast proliferation and ECM secretion, while also up-regulating expression of CaMKII deltaB and deltaC. More importantly, CaMKII inhibitors, autocamtide-2-related inhibitory peptide (AIP 5 microM) or KN93 (0.5 microM), suppressed cardiac fibroblast proliferation, inhibited the excretion of transforming growth factor beta1 and tumor necrosis factor alpha, decreased the messenger RNA expression of MMP-1, 2, 9 and collagen I/III, and decreased the protein expression of MMP-2, 9. These results suggest that CaMKII mediates cardiac fibroblast proliferation and ECM secretion induced by either AngII or EFS.

1. G-Protein-coupled receptors (GPCR) and electrical field stimulation (EFS) regulate cardiac function and pathological remodelling, including cardiac hypertrophy. Cardiac Ca(2+)/calmodulin-dependent protein kinase (CaMK) IIdelta expression and activity are altered in cardiac hypertrophy and heart failure. The aim of the present study was to determine the effects of CaMKIIdelta isoforms on neonatal rat cardiomyocyte hypertrophy induced by GPCR and EFS. 2. Cardiac hypertrophy was induced by angiotensin II, phenylephrine or EFS and was confirmed by increases in cell volume, [(3)H]-leucine incorporation, sarcomere assembly and mRNA expression of atrial natriuretic factor and beta-myosin heavy chain. The effects of the CaMKII inhibitors KN93 and autocamtide 2-related inhibitory peptide (AIP) on cardiomyocyte hypertrophy were investigated, as was the effect of overexpression of dominate negative CaMKIIdelta. 3. Cardiomyocyte hypertrophy was inhibited by the CaMKII inhibitors KN93 and AIP and by overexpression of dominate negative CaMKIIdelta, but was potentiated by overexpression of wild-type CaMKIIdeltaB or CaMKIIdeltaC. Activation of CaMKII by GPCR agonists or EFS was inhibited by the CaMKII inhibitors. 4. The GPCR agonists and EFS synergistically activated CaMKII and upregulated CaMKIIdeltaB and CaMKIIdeltaC mRNA expression and protein synthesis. All these effects were abolished by the CaMKII inhibitors. 5. The findings of the present study indicate that CaMKII orchestrates additive prohypertrophic factors between GPCR agonists and EFS. Thus, CaMKII may be a useful target in the clinical treatment of hypertrophy and cardiac remodelling.

The presence of cancer stem-like cells (CSCs) is one of the mechanisms responsible for chemoresistance that has been a major hindrance towards lung adenocarcinoma (LAD) treatment. Recently, we have identified microRNA (miR)-200b as a key regulator of chemoresistance in human docetaxel-resistant LAD cells. However, whether miR-200b has effects on regulating CSCs remains largely unclear and needs to be further elucidated. Here, we showed that miR-200b was significantly downregulated in CD133+/CD326+ cells that exhibited properties of CSCs derived from docetaxel-resistant LAD cells. Also, restoration of miR-200b could inhibit maintenance and reverse chemoresistance of CSCs. Furthermore, suppressor of zeste-12 (Suz-12) was identified as a direct and functional target of miR-200b, and silencing of Suz-12 phenocopied the effects of miR-200b on CSCs. Additionally, overexpression of histone deacetylase (HDAC) 1 was identified as a pivotal mechanism responsible for miR-200b repression in CSCs through a specificity protein (Sp) 1-dependent mechanism, and restoration of miR-200b by HDAC1 repression significantly suppressed CSCs formation and reversed chemoresistance of CSCs by regulating Suz-12-E-cadherin signaling. Also, downregulation of HDAC1 or upregulation of miR-200b reduced the in vivo tumorigenicity of CSCs. Finally, Suz-12 was inversely correlated with miR-200b, positively correlated with HDAC1 and up-regulated in docetaxel-resistant LAD tissues compared with docetaxel-sensitive tissues. Taken together, the HDAC1/miR-200b/Suz-12-E-cadherin signaling might account for maintenance of CSCs and formation of chemoresistant phenotype in docetaxel-resistant LAD cells.

Background Docetaxel resistance remains a major obstacle in the treatment of non-small cell lung cancer (NSCLC). High-mobility group box 1 (HMGB1) has been shown to promote autophagy protection in response to antitumor therapy, but the exact molecular mechanism underlying HMGB1-mediated autophagy has not been clearly defined. Methods Lung adenocarcinoma (LAD) cells were transfected with pcDNA3.1-HMGB1 or HMGB1 shRNA, followed by docetaxel treatment. Cell viability and proliferation were tested by MTT assay and colony formation assay, respectively. Annexin V flow cytometric analysis and western blot analysis of activated caspase3 and cleaved PARP were used to evaluate apoptosis, while immunofluorescence microscopy and transmission electron microscopy were applied to assess autophagy activity. The formation of the Beclin-1-PI3K-III complex was examined by immunoprecipitation analysis. NOD/SCID mice were inoculated with docetaxel-resistant SPC-A1/DTX cells transfected with control or HMGB1 shRNA. Results HMGB1 translocated from the nucleus to the cytoplasm in LAD cells exposed to docetaxel and acted as a positive regulator of autophagy, which inhibited apoptosis and increased drug resistance. Suppression of HMGB1 restored the sensitivity of LAD cells to docetaxel both in vivo and in vitro. Mechanistic investigation revealed that HMGB1 promoted the formation of the Beclin-1-PI3K-III complex through activating the mitogen-activated protein kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling pathway, thereby regulating autophagosome formation. Conclusions Our results demonstrated that HMGB1-regulated autophagy is a significant contributor to docetaxel resistance in LAD cells. Suppression of HMGB1 or limiting HMGB1 cytosolic translocation diminished autophagic protection in response to docetaxel in LAD cells.