Motility behavior and physiological response mechanisms of aerobic denitrifier, Enterobacter cloacae strain HNR under high salt stress: Insights from individual cells to populations.

The motility behaviors at the individual-cell level and the collective physiological responsive behaviors of aerobic denitrifier, Enterobacter cloacae strain HNR under high salt stress were investigated. The results revealed that as salinity increased, electron transport activity and adenosine triphosphate content decreased from 15.75 µg O2/g/min and 593.51 mM/L to 3.27 µg O2/g/min and 5.34 mM/L, respectively, at 40 g/L, leading to a reduction in the rotation velocity and vibration amplitude of strain HNR. High salinity stress (40 g/L) down-regulated genes involved in ABC transporters (amino acids, sugars, metal ions, and inorganic ions) and activated the biofilm-related motility regulation mechanism in strain HNR, resulting in a further decrease in flagellar motility capacity and an increase in extracellular polymeric substances secretion (4.08 mg/g cell of PS and 40.03 mg/g cell of PN at 40 g/L). These responses facilitated biofilm formation and proved effective in countering elevated salt stress in strain HNR. Moreover, the genetic diversity associated with biofilm-related motility regulation in strain HNR enhanced the adaptability and stability of the strain HNR populations to salinity stress. This study enables a deeper understanding of the response mechanism of aerobic denitrifiers to high salt stress.

Gastrodin inhibits prostate cancer proliferation by targeting canonical Wnt/ß-catenin signaling pathway.

Prostate cancer is an epithelial malignant tumor occurring in the prostate and is the most common malignant tumor in the male genitourinary system. In recent years, the incidence of prostate cancer in China has shown a trend of sudden increase. The search for new and effective drugs to treat prostate cancer is therefore extremely important.The canonical Wnt/ß-catenin signaling pathway has been shown to be involved in the regulation of tumor proliferation, migration and differentiation. Activation of the canonical Wnt/ß-Catenin signaling pathway in the prostate has oncogenic effects. Drugs targeting the canonical Wnt/ß-catenin signaling pathway have great potential in the treatment of prostate cancer. In this study, we found that Gastrodin could significantly inhibit the proliferation of prostate cancer cell line PC3 and DU145. Oral administration Gastrodin could significantly inhibit the tumor growth of PC3 cells subcutaneously injected. Gastrodin has an inhibitory effect on canonical Wnt/ß-Catenin signaling pathway in Prostate cancer, and this inhibitory effect can be abolished by Wnt/ß-Catenin agonist LiCl. These findings raise the possibility that Gastrodin can be used in the treatment of Prostate cancer by targeting canonical Wnt/ß-Catenin signaling pathway.

Salidroside suppresses proliferation and migration in prostate cancer via the PI3K/AKT pathway.

BACKGROUND: Prostate cancer (PCa) is one of the most common malignancies in men. PCa is difficult to detect in its early stages, and most patients are diagnosed in the middle to late stages. At present, drug therapy for advanced PCa is still insufficient. Some patients develop drug resistance in the later stage of therapy, which leads to tumor recurrence, metastasis and even treatment failure. Therefore, it is crucial to find new and effective drugs to treat prostate cancer. OBJECTIVE: The aim of this study was to investigate the anti-cancer effect of salidroside, an active ingredient in a traditional Chinese herbal medicine, on PCa. METHODS: Two human PCa cell lines, PC3 and DU145, were cultured and treated with salidroside. Cell viability and proliferation ability were analyzed through CCK-8 and colony assays, and cell migration ability was detected by Transwell and Scratch assays. RT-PCR and WB were used to detected the expression levels of moleculars related to cell proliferation, apoptosis, migration, and AKT signaling pathway. Forthmore, we performed rescue experiments with agonist to verify the affected signaling pathway. RESULTS: Salidroside inhibited the proliferation, colony formation, and migration of PCa cells. Meanwhile, apoptosis of PCa cells was enhanced. Moreover, salidroside inhibited PI3K/AKT pathway in PCa cells. The treatment of AKT agonist 740Y-P abrogated the inhibitory effect of salidroside on the PI3K/AKT signaling pathway. CONCLUSIONS: Our study demonstrated that in PCa cells, salidroside inhibites proliferation and migration and promots apoptosis via inhibiting PI3K/AKT pathway.

Longitudinal Spinous-Splitting Laminoplasty with Coral Bone for the Treatment of Cervical Adjacent Segment Degenerative Disease: A 5-Year Follow-up Study.

This study was designed to analyze the causes of cervical adjacent segment degenerative disease (ASDis), evaluate the surgical outcomes of longitudinal spinous-splitting laminoplasty with coral bone (SLAC) during cervical reoperation, and accumulate data on reoperation with SLAC in a primary hospital. Based on the inclusion and exclusion criteria, we conducted a retrospective study involving 52 patients who underwent cervical reoperation for ASDis using SLAC at the spinal surgery department of the Beijing Jishuitan Hospital from 1998 to 2014. Among them, 39 were treated with anterior cervical fusion and internal fixation during the first operation (anterior cervical corpectomy with fusion [ACCF], n = 24; anterior cervical discectomy and fusion [ACDF], n = 11; and cervical disc arthroplasty [CDA], n = 4). Outcomes were the Japanese Orthopaedic Association (JOA) score, neck disability index (NDI) score, upper limb/neck and shoulder evaluated using a visual analogue scale (VAS), and rates of ASDis. In patients who underwent an anterior cervical approach in the first instance, the incidence of ASDis was significantly higher in the C3/4 gap than in the other gaps. In the ACCF group, the lateral radiograph of the cervical spine revealed that the distance between the anterior cervical plate and the adjacent segment disc was <5 mm in 15 (62.5%) cases and five (12.8%) cases, respectively, the internal fixation screws broke into the annulus of the adjacent segment. After the first SLAC, ASDis developed at C2/3 and C3/4 in four (30.8%) and eight (61.5%) cases, respectively. After reoperation, all cases were followed up for >5 (average, 6.2) years. The pre-reoperation and last follow-up values were as follows: mean Japanese Orthopaedic Association score, 10.2 ± 1.5 vs 15.5 ± 0.7 (P = 0.03); neck disability index, 26.2 vs 13.6 points (P = 0.01); upper-limb visual analog scale (VAS) score, 6.1 vs 2.6 points (P = 0.04); and neck and shoulder VAS score, 6.6 vs 2.1 points (P = 0.03). SLAC is a simple technique in which the local anatomy is clearly visible and satisfactory clinical outcomes are obtained.

Identification of valid reference genes for mRNA and microRNA normalisation in prostate cancer cell lines.

RT-qPCR offers high sensitivity, for accurate interpretations of qPCR results however, normalisation using suitable reference genes is fundamental. Androgens can regulate transcriptional expression including reference gene expression in prostate cancer. In this study, we evaluated ten mRNA and six non-protein coding RNA reference genes in five prostate cell lines under varied dihydrotestosterone (DHT) treatments. We validated the effects of DHT-treatments using media containing charcoal-stripped serum prior to DHT stimulation on the test samples by Western blot experiments. Reference gene expression stability was analysed using three programs (geNorm, NormFinder and BestKeeper), and the recommended comprehensive ranking is provided. Our results reveal that ACTB and GAPDH, and miR-16 and miR-1228-3p are the most suitable mRNA and miRNA reference genes across all cell lines, respectively. Considering prostate cancer cell types, ACTB/GAPDH and ACTB/HPRT1 are the most suitable reference gene combinations for mRNA analysis, and miR-16/miR-1228-3p and RNU6-2/RNU43 for miRNA analysis in AR+, and AR- and normal cell lines, respectively. Comparison of relative target gene (PCA3 and miR-141) expression reveals different patterns depending on reference genes used for normalisation. To our knowledge, this is the first report on validation of reference genes under different DHT treatments in prostate cancer cells. This study provides insights for discovery of reliable DHT-regulated genes in prostate cells.

Dexmedetomidine prevents post-ischemic LTP via presynaptic and postsynaptic mechanisms.

Increasing evidence indicates that dexmedetomidine (DEX), a selective α2-adrenergic receptor agonist, has a neuroprotective effect against cerebral injury. However, it remains unknown whether and how DEX functionally prevents the pathological form of synaptic plasticity caused by ischemia in the hippocampal CA1 neurons. To address this issue, we analyzed the role of DEX using a model of brain ischemia (oxygen and glucose deprivation, OGD) referred to as post-ischemic LTP (i-LTP). We found that DEX could reduce i-LTP by selectively activating α2 receptors. To clarify its detailed mechanisms, the presynaptic and postsynaptic roles of DEX were investigated. The activation of the α2 receptors of DEX decreased the frequency spontaneous mEPSCs, which exerted its presynaptic mechanisms. In addition, DEX also decreased the amplitude of mEPSCs and prevented the depolarization of postsynaptic membranes during OGD treatment, which exerted its postsynaptic mechanisms. More importantly, our results indicate that postsynaptic ß receptors, not α1 receptors, participated in i-LTP. Therefore, these results demonstrated that decreasing ß receptors activation by DEX-medicated pre- and post-synaptic α2 receptors activation is responsible for i-LTP. Because of the NMDARs required for i-LTP, we further examined the critical roles of postsynaptic ß receptors downstream PKA regulation of NMDA receptor-mediated EPSCs (NMDA EPSC). We clarified that it is attributable to the direct effect of DEX on NMDA EPSC as mediated by PKA inactivation. These findings suggest that DEX can protect neurons from functional damage caused by a relatively mild degree of transient cerebral ischemia, and this effect is mediated by both presynaptic reduction of NE and glutamate release and postsynaptic suppression of NMDAR activation by ß receptors and downstream PKA regulation.

Role of miR-155 in drug resistance of breast cancer.

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expressions at posttranscriptional level. Growing evidence points to their significant role in the acquisition of drug resistance in cancers. Studies show that miRNAs are often aberrantly expressed in human cancer cells which are associated with tumorigenesis, metastasis, invasiveness, and drug resistance. Breast cancer is the leading cause of cancer-induced death in women. Over the last decades, increasing attention has been paid to the effects of miRNAs on the development of breast cancer drug resistance. Among them, miR-155 takes part in a sequence of bioprocesses that contribute to the development of such drug resistance, including repression of FOXO3a, enhancement of epithelial-to-mesenchymal transition (EMT) and mitogen-activated protein kinase (MAPK) signaling, reduction of RhoA, and affecting the length of telomeres. In this review, we discuss the role of miR-155 in the acquisition of breast cancer drug resistance. This will provide a new way in antiresistance treatment of drug-resistant breast cancer.

Identification of valid reference genes for the normalization of RT-qPCR expression studies in human breast cancer cell lines treated with and without transient transfection.

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is a powerful technique for examining gene expression changes during tumorigenesis. Target gene expression is generally normalized by a stably expressed endogenous reference gene; however, reference gene expression may differ among tissues under various circumstances. Because no valid reference genes have been documented for human breast cancer cell lines containing different cancer subtypes treated with transient transfection, we identified appropriate and reliable reference genes from thirteen candidates in a panel of 10 normal and cancerous human breast cell lines under experimental conditions with/without transfection treatments with two transfection reagents. Reference gene expression stability was calculated using four algorithms (geNorm, NormFinder, BestKeeper and comparative delta Ct), and the recommended comprehensive ranking was provided using geometric means of the ranking values using the RefFinder tool. GeNorm analysis revealed that two reference genes should be sufficient for all cases in this study. A stability analysis suggests that 18S rRNA-ACTB is the best reference gene combination across all cell lines; ACTB-GAPDH is best for basal breast cancer cell lines; and HSPCB-ACTB is best for ER+ breast cancer cells. After transfection, the stability ranking of the reference gene fluctuated, especially with Lipofectamine 2000 transfection reagent in two subtypes of basal and ER+ breast cell lines. Comparisons of relative target gene (HER2) expression revealed different expressional patterns depending on the reference genes used for normalization. We suggest that identifying the most stable and suitable reference genes is critical for studying specific cell lines under certain circumstances.

Exosomes mediate drug resistance transfer in MCF-7 breast cancer cells and a probable mechanism is delivery of P-glycoprotein.

Acquired drug resistance is a major obstacle to chemotherapy of cancers. In this study, we aim to investigate the role of exosomes in drug-resistance transfer between breast cancer cells and detect the probable mechanism. A docetaxel-resistant variant of MCF-7 cell line (MCF-7/DOC) was established and then compared with the drug-sensitive variant (MCF-7/S). Exosomes were expelled from the cell supernatant using ultracentrifugation. Drug resistance was assessed by apoptosis assay and MTT examination. Expressions of P-glycoprotein (P-gp) were analyzed by flow cytometry. Stained exosomes were absorbed by receipt cells. MCF-7/S in the presence of exosomes extracted from the supernatant of MCF-7/DOC (DOC/exo) acquired drug resistance, while MCF-7/S exposed to their own exosomes (S/exo) did not. P-gp expression patterns of exosomes were similar as the originated cells. P-gp expression of MCF-7/S increased after incubation with DOC/exo and was affected by the amount of exosomes. Exosomes are effective in transferring drug resistance as well as P-gp from drug-resistant breast cancer cells to sensitive ones. The delivery of P-gp via exosomes may be a mechanism of exosome-mediated drug resistance transfer.

Down-regulation of miRNA-452 is associated with adriamycin-resistance in breast cancer cells.

Adriamycin (ADR) is an important chemotherapeutic agent frequently used in treatment of breast cancer. However, resistance to ADR results in treatment failure in many patients. Recent studies have indicated that microRNAs (miRNAs) may play an important role in such drug-resistance. In the present study, microRNA-452 (miR-452) was found to be significantly down-regulated in adriamycin-resistant MCF-7 cells (MCF-7/ADR) compared with the parental MCF-7 cells by miRNA microarray and real-time quantitative PCR (RT-qPCR). MiR-452 mimics and inhibitors partially changed the adriamycin-resistance of breast cancer cells, as also confirmed by apoptosis assay. In exploring the potential mechanisms of miR-452 in the adriamycin-resistance of breast cancer cells, bioinformatics analysis, RT-qPCR and Western blotting showed that dysregulation of miR-452 played an important role in the acquired adriamycin-resistance of breast cancer, maybe at least in part via targeting insulin-like growth factor-1 receptor (IGF-1R).

Exosomes from docetaxel-resistant breast cancer cells alter chemosensitivity by delivering microRNAs.

Breast cancer (BCa) remains chemo-unresponsive by inevitable progression of resistance to first-line treatment with docetaxel (doc). Emerging studies indicate that exosomes act as mediators of intercellular communication between heterogeneous populations of tumor cells, engendering a transmitted drug resistance for cancer development. Such modulatory effects have been related to the constant shuttle of biologically active molecules including microRNAs (miRNAs). Here, we aimed to investigate the relevance of exosome-mediated miRNA delivery in resistance transmission of BCa subpopulations. Using microarray and polymerase chain reaction, we found that exosomes from doc-resistant BCa cells (D/exo) loaded cellular miRNAs. Following D/exo transfer to the fluorescent sensitive cells (GFP-S), some miRNAs were significantly increased in recipient GFP-S. Target gene prediction and pathway analysis revealed the involvement of the top 20 most abundant miRNAs of D/exo in pathways implicated in therapy failure. Coculture assays showed that miRNA-containing D/exo increased the overall resistance of GFP-S to doc exposure. Moreover, D/exo was able to alter gene expression in GFP-S. Our results open up an intriguing possibility that drug-resistant BCa cells may spread chemoresistance to sensitive ones by releasing exosomes and that the effects could be partly attributed to the intercellular transfer of specific miRNAs.

C1420T polymorphism of cytosolic serine hydroxymethyltransferase and risk of cancer: a meta-analysis.

A series of studies have explored the role of cytosolic serine hydroxymethyltransferase (SHMT1) C1420T polymorphism in cancer risk, but their results were conflicting rather than conclusive. To derive a more precise estimation of the association between C1420T and cancer risk, the present meta-analysis of 28 available studies with 15,121 cases and 18,023 controls was conducted. The results revealed that there was no significant association between the polymorphism and cancer risk overall. In stratified analysis by cancer type (breast cancer, gastrointestinal cancer, leukemia, lymphoma, and others), the results showed that 1420T allele was associated with decreased risk in leukemia (CT vs. CC: OR= 0.825, 95% CI =0.704-0.966; and CT+TT vs. CC: OR= 0.838, 95% CI = 0.722-0.973), but the same results were not present for other cancer types. When subgroup analysis was performed by source of control (population-based [PB] and hospital-based [HB]), a borderline inverse association was observed for the HB subgroup (CT vs. CC: OR= 0.917, 95% CI = 0.857-0.982) but not for the PB subgroup. Stratifying by geographic area (America, Asia and Europe), significant inverse association was only found in Asia subgroup (CT vs. CC: OR= 0.674, 95% CI = 0.522-0.870). In summary, the findings suggest that SHMT1 C1420T polymorphism is not associated with overall cancer development, but might decrease cancer susceptibility of Asians as well as reduce leukemia risk. Large well-designed epidemiological studies will be necessary to validate the risk identified in the current meta-analysis.

MicroRNA-452 contributes to the docetaxel resistance of breast cancer cells.

MicroRNA-452 (miRNA-452) was overexpressed in docetaxel-resistant human breast cancer MCF-7 cells (MCF-7/DOC). However, its role in modulating the sensitivity of breast cancer cells to docetaxel (DOC) remains unclear. The aim of this study is to investigate the role of miRNA-452 in the sensitivity of breast cancer cells to DOC.Real-time quantitative PCR (RT-qPCR) were used to identify the differential expression of miRNA-452 between MCF-7/DOC and MCF-7 cells. MiRNA-452 mimic was transfected into MCF-7 cells and miRNA-452 inhibitor was transfected into MCF-7/DOC cells. The role of miRNA-452 in these transfected cells was evaluated using RT-qPCR, MTT assay, and flow cytometry assay. The relationship of miRNA-452 and its predictive target gene "anaphase-promoting complex 4" (APC4) was analyzed by RT-qPCR and Western blot.MiRNA-452 showed significantly higher expression (78.9-folds) in MCF-7/DOC cells compared to parental MCF-7 cells. The expression of miRNA-452 in the mimic transfected MCF-7 cells was upregulated 212.2-folds (P < 0.05) compared to its negative control (NC), and the half maximal inhibitory concentration (IC50) value of DOC (1.98 ± 0.15 µM) was significantly higher than that in its NC (0.85 ± 0.08 µM, P < 0.05) or blank control (1.01 ± 0.19 µM, P < 0.05). Furthermore, its apoptotic rate (6.3 ± 1.3 %) was distinctly decreased compared with that in its NC (23.8 ± 6.6 %, P < 0.05) or blank control (18.6 ± 4.7 %, P < 0.05). In contrast, the expression of miRNA-452 in the inhibitor-transfected MCF-7/DOC cells was downregulated 0.58-fold (P < 0.05) compared to its NC, the IC50 value of DOC (44.5 ± 3.2 µM) was significantly lower than that in its NC (107.3 ± 6.63 µM, P < 0.05) or blank control (102.22 ± 11.34 µM, P < 0.05), and the apoptotic rate (45.5 ± 10.8 %) was distinctly increased compared with its NC (9.9 ± 2.2 %, P < 0.05) and blank control (9.4 ± 2.5 %, P < 0.05). Further, there was an inverse association between miRNA-452 and APC4 expression in breast cancer cells in vitro.Dysregulation of miRNA-452 involved in the DOC resistance formation of breast cancer cells may be, in part, via targeting APC4.

Salusin-ß not salusin-α promotes vascular inflammation in ApoE-deficient mice via the I-κBα/NF-κB pathway.

OBJECTIVE: Vascular inflammation plays an important role in the development and progression of atherosclerosis. Recently, salusins (salusin-α and salusin-ß) have been reported to be associated wtih atherosclerosis. However, its underlying mechanism remains incompletely known. In this study, we observed the effects of salusins on vascular inflammation in apoE-deficient (apoE-/-) mice. METHODS AND RESULTS: Six-week old male apoE-/- mice were infused with salusin-α, salusin-ß or vehicle for 8 weeks via osmotic mini-pumps. Our results showed that apoE-/- mice receiving vehicle alone developed severe atherosclerotic lesions and dyslipidemia, with significantly up-regulated levels of IL-6, TNF-α, VCAM-1 and MCP-1. For apoE-/- mice receiving 8 weeks of salusin-ß infusion, the atherosclerotic lesions were markedly aggravated, and the levels of IL-6, TNF-α, VCAM-1 and MCP-1 were substantially increased, despite a similar plasma lipid concentration with that of apoE-/- mice. However, after 8 week-infusion of salusin-α, apoE-/- mice presented significant amelioration in atherosclerotic lesions, along with remarkably up-regulated level of high-density lipoprotein-cholesterol (HDL-C) and down-regulated levels of IL-6 and TNF-α, but without any effect on the expressions of VCAM-1 and MCP-1. Furthermore, the activation of nuclear factor-κB (NF-κB), an important transcription factor essential for inflammatory molecules, and the degradation of I-κBα, an inhibitor of NF-κB, were markedly increased in apoE-/- mice receiving vehicle alone. Treatment with salusin-ß not salusin-α could remarkably accelerate the process of NF-κB nuclear translocation and I-κBα degradation. CONCLUSION: Salusin-ß, but not salusin-α, promotes vascular inflammation in apoE-deficient mice via the I-κBα/NF-κB pathway. These findings provide further insight into the mechanism of salusins in atherosclerosis and potential targets for the prevention and treatment of atherosclerosis.

Ghrelin alleviates neuropathic pain through GHSR-1a-mediated suppression of the p38 MAPK/NF-κB pathway in a rat chronic constriction injury model.

BACKGROUND AND OBJECTIVES: Neuropathic pain is related to the sustained activation of neuroglial cells and the production of proinflammatory cytokines in the spinal dorsal horn. Ghrelin, the endogenous ligand for growth hormone secretagogue receptor 1a (GHSR-1a), has been shown to inhibit the activation of microglia and the release of proinflammatory cytokines. The purpose of this study was to investigate the role of ghrelin/GHSR-1a signaling in neuropathic pain and to understand the associated mechanisms. METHODS: A rat model of neuropathic pain was established by chronic constriction injury (CCI) of the sciatic nerve. Hyperalgesia and allodynia were evaluated by observing the mechanical withdrawal threshold and the thermal withdrawal latency. The expression levels of ghrelin and GHSR-1a were detected by semiquantitative reverse transcriptase-polymerase chain reaction and Western blot analysis. The levels of interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α were detected using an enzyme-linked immunosorbent assay. The expression levels of p-p38 mitogen-activated protein kinases (p38 MAPK) and nuclear factor-κB (NF-κB) p65 were determined by Western blot and immunohistochemistry analysis. RESULTS: Both ghrelin and GHSR-1a were expressed in the spinal dorsal horns of normal rats and were not significantly different from that of sham rats. However, rats in the CCI model group developed severe hyperalgesia and allodynia, as well as significantly downregulated expression of ghrelin and GHSR-1a. Compared with CCI model rats, intrathecal injection of ghrelin clearly delayed thermal hyperalgesia and mechanical allodynia at 3, 5, and 7 days after CCI; reduced the levels of IL-1ß, IL-6, and tumor necrosis factor-α; and inhibited the phosphorylation of p38 MAPK and the activation of NF-κBp65 in the spinal dorsal horn. In addition, the effect of ghrelin could be blocked by [D-Lys]-GHRP-6, a GHSR-1a antagonist. CONCLUSIONS: Our present study demonstrated that ghrelin alleviated neuropathic pain through a GHSR-1a-mediated suppression of the p38 MAPK/NF-κB pathway.