Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

Co-activation of nAChR and mGluR induces γ oscillation in rat medial septum diagonal band of Broca slices.

AIM: To examine whether co-activation of nAChR and mGluR1 induced γ oscillation (20-60 Hz) in rat medial septum diagonal band of Broca (MSDB) slices. METHODS: Rat brain sagittal slices containing the MSDB were prepared. Extracellular field potentials were recorded with glass microelectrodes. The nAChR and mGluR1 agonists were applied to the slices to induce network activity. Data analysis was performed off-line using software Spike 2. RESULTS: Co-application of the nAChR agonist nicotine (1 µmol/L) and the mGluR1 agonist dihydroxyphenylglycine (DHPG, 25 µmol/L) was able to induce γ oscillation in MSDB slices. The intensity of nAChR and mGluR1 activation was critical for induction of network oscillation at a low (θ oscillation) or high frequency (γ oscillation): co-application of low concentrations of the two agonists only increased the power and frequency of oscillation within the range of θ, whereas γ oscillation mostly appeared when high concentrations of the two agonists were applied. CONCLUSION: Activation of mGluR1 and nAChR is able to program slow or fast network oscillation by altering the intensity of receptor activation, which may provide a mechanism for modulation of learning and memory.

MORC2 regulates RBM39-mediated CDK5RAP2 alternative splicing to promote EMT and metastasis in colon cancer.

Colorectal carcinogenesis and progression are associated with aberrant alternative splicing, yet its molecular mechanisms remain largely unexplored. Here, we find that Microrchidia family CW-type zinc finger 2 (MORC2) binds to RRM1 domain of RNA binding motif protein 39 (RBM39), and RBM39 interacts with site 1 of pre-CDK5RAP2 exon 32 via its UHM domain, resulting in a splicing switch of cyclin-dependent kinase 5 regulatory subunit associated protein 2 (CDK5RAP2) L to CDK5RAP2 S. CDK5RAP2 S promotes invasion of colorectal cancer cells in vitro and metastasis in vivo. Mechanistically, CDK5RAP2 S specifically recruits the PHD finger protein 8 to promote Slug transcription by removing repressive histone marks at the Slug promoter. Moreover, CDK5RAP2 S, but not CDK5RAP2 L, is essential for the promotion of epithelial-mesenchymal transition induced by MORC2 or RBM39. Importantly, high protein levels of MORC2, RBM39 and Slug are strongly associated with metastasis and poor clinical outcomes of colorectal cancer patients. Taken together, our findings uncover a novel mechanism by which MORC2 promotes colorectal cancer metastasis, through RBM39-mediated pre-CDK5RAP2 alternative splicing and highlight the MORC2/RBM39/CDK5RAP2 axis as a potential therapeutic target for colorectal cancer.

Effects of nicotine stimulation on spikes, theta frequency oscillations, and spike-theta oscillation relationship in rat medial septum diagonal band Broca slices.

AIM: Spiking activities and neuronal network oscillations in the theta frequency range have been found in many cortical areas during information processing. The aim of this study is to determine whether nicotinic acetylcholine receptors (nAChRs) mediate neuronal network activity in rat medial septum diagonal band Broca (MSDB) slices. METHODS: Extracellular field potentials were recorded in the slices using an Axoprobe 1A amplifier. Data analysis was performed off-line. Spike sorting and local field potential (LFP) analyses were performed using Spike2 software. The role of spiking activity in the generation of LFP oscillations in the slices was determined by analyzing the phase-time relationship between the spikes and LFP oscillations. Circular statistic analysis based on the Rayleigh test was used to determine the significance of phase relationships between the spikes and LFP oscillations. The timing relationship was examined by quantifying the spike-field coherence (SFC). RESULTS: Application of nicotine (250 nmol/L) induced prominent LFP oscillations in the theta frequency band and both small- and large-amplitude population spiking activity in the slices. These spikes were phase-locked to theta oscillations at specific phases. The Rayleigh test showed a statistically significant relationship in phase-locking between the spikes and theta oscillations. Larger changes in the SFC were observed for large-amplitude spikes, indicating an accurate timing relationship between this type of spike and LFP oscillations. The nicotine-induced spiking activity (large-amplitude population spikes) was suppressed by the nAChR antagonist dihydro-ß-erythroidine (0.3 µmol/L). CONCLUSION: The results demonstrate that large-amplitude spikes are phase-locked to theta oscillations and have a high spike-timing accuracy, which are likely a main contributor to the theta oscillations generated in MSDB during nicotine receptor activation.

Clinical Management of Primary Biliary Cholangitis-Strategies and Evolving Trends.

PBC is a chronic progressive autoimmune disorder involving the destruction of intrahepatic small bile ducts, cholestasis, fibrosis, and ultimately cirrhosis if left untreated. It is largely driven by the autoimmune response, but bile acids and the intestinal microbiota are implicated in disease progression as well. The only drugs licensed for PBC are UDCA and OCA. UDCA as a first-line and OCA as a second-line therapy are safe and effective, but the lack of response in a significant portion of patients and inadequate control of symptoms such as fatigue and pruritus remain as concerns. Liver transplantation is an end-stage therapy for many patients refractory to UDCA, which gives excellent survival rates but also moderate to high recurrence rates. The limited options for FDA-approved PBC therapies necessitate the development of alternative approaches. Currently, a wide variety of experimental drugs exist targeting immunological and physiological aspects of PBC to suppress inflammation. Immunological therapies include drugs targeting immune molecules in the B cell and T cell response, and specific cytokines and chemokines implicated in inflammation. Drugs targeting bile acids are also noteworthy as bile acids can perpetuate hepatic inflammation and lead to fibrosis over time. These include FXR agonists, ASBT inhibitors, and PPAR agonists such as bezafibrate and fenofibrate. Nonetheless, many of these drugs can only delay disease progression and fail to enhance patients' quality of life. Nanomedicine shows great potential for treatment of autoimmune diseases, as it provides a new approach that focuses on tolerance induction rather than immunosuppression. Tolerogenic nanoparticles carrying immune-modifying agents can be engineered to safely and effectively target the antigen-specific immune response in autoimmune diseases. These may work well with PBC especially, given the anatomical features and immunological specificity of the disease. Nanobiological therapy is thus an area of highly promising research for future treatment of PBC.

Sulforaphane metabolites cause apoptosis via microtubule disruption in cancer.

Sulforaphane (SFN) inhibited growth in many cancers, but its half-life is 2 h in circulation. However, its metabolites, sulforaphane-cysteine (SFN-Cys) and sulforaphane-N-acetyl-cysteine (SFN-NAC) had longer half-lives and decreased the cell viability in both dose- and time-dependent manners in human prostate cancer. Flow cytometry assay revealed that these two SFN metabolites induced apoptosis with the features such as vacuolization, disappeared nuclear envelope, nuclear agglutination and fragmentation via transmission electron microscopy observation. Western blot showed that the sustained phosphorylation of ERK1/2 mediated by SFN metabolites caused activation and upregulation of cleaved Caspase 3 and downregulation of α-tubulin. High expression of α-tubulin was demonstrated to be positively correlated with cancer pathological grading. Both co-immunoprecipitation and immunofluorescence staining implicated the interaction between SFN metabolite-induced phosphorylated ERK1/2 and α-tubulin, and Caspase 3 cleavage assay showed that α-tubulin might be the substrate for cleaved Caspase 3. More, the SFN metabolite-mediated reduction of α-tubulin increased the depolymerization and instability of microtubules by microtubule polymerization assay. Reversely, microtubule-associated protein Stathmin-1 phosphorylation was increased via phosphorylated ERK1/2 and total Stathmin-1 was reduced, which might promote over-stability of microtubules. Immunofluorescence staining also showed that SFN metabolites induced the 'nest-like' structures of microtubule distribution resulting from the disrupted and aggregated microtubules, and abnormal nuclear division, suggesting that the disturbance of spindle formation and mitosis turned up. Thus, SFN-Cys and SFN-NAC triggered the dynamic imbalance of microtubules, microtubule disruption leading to cell apoptosis. These findings provided a novel insight into the chemotherapy of human prostate cancer.

Sulforaphane-N-Acetyl-Cysteine inhibited autophagy leading to apoptosis via Hsp70-mediated microtubule disruption.

Sulforaphane-N-acetyl-cysteine (SFN-NAC) is a potential drug to inhibit human non-small cell lung cancer (NSCLC), but the underlying mechanisms are elusive. Here, we uncovered that SFN-NAC induced apoptosis via flow cytometer assay and transmission electron microscopy. Further, SFN-NAC increased LC3 II/LC3 I and the number of LC3 punctas, but Western blot showed that SFN-NAC inhibited cell autophagy in response to a co-treatment of Bafilomycin A1 and SFN-NAC. Furthermore, immunofluorescence staining and Western blot showed that SFN-NAC triggered microtubule disruption causing apoptosis via downregulating α-tubulin and phosphorylated ERK1/2-mediated Stathmin-1. Besides, SFN-NAC upregulated Hsp70 via phosphorylating ERK1/2. Confocal microscopy and immunoprecipitation assay showed that SFN-NAC promoted the colocalization and interaction of Hsp70 and α-tubulin; knockdown of Hsp70 enhanced SFN-NAC-induced microtubule disruption, lowered LC3 II/LC3 I and promoted apoptosis. Interestingly, tissue microarray analysis showed that the increased expression of either α-tubulin or Hsp70 correlated to NSCLC malignant grading, indicating that microtubule and Hsp70 are two key targets for SFN-NAC. These results will give us a new insight into SFN-NAC-induced apoptosis so that we develop more efficient therapeutics to treat NSCLC.

Sulforaphane-cysteine induces apoptosis by sustained activation of ERK1/2 and caspase 3 in human glioblastoma U373MG and U87MG cells.

We previously demonstrated that sulforaphane (SFN) inhibited invasion via sustained activation of ERK1/2 in human glioblastoma cells. However, sulforaphane-cysteine (SFN-Cys), an analog of SFN, enriched in plasma with longer half-life, had more potentiality to induce apoptosis. Here we investigated the molecular mechanisms of SFN-Cys-induced apoptosis in human glioblastoma U373MG and U87MG cells. Cell viability assay showed that SFN-Cys inhibited cell viability in a dose-dependent manner. Cell morphology observation also showed SFN-Cys increased the phenotype of cell death in a dose-dependent manner. Furthermore, flow cytometry assay showed that SFN-Cys induced apoptosis significantly in a dose-dependent manner in both cell lines. Furthermore, western blot analysis demonstrated that SFN-Cys induced activation of ERK1/2 in a sustained manner and the activation contributed to upregulation of Bax/Bcl-2 ratio and cleaved caspase 3, and these results can be reversed by the ERK1/2 blocker PD98059. Our results showed that SFN-Cys induced cell apoptosis via sustained activation of ERK1/2 and the ERK1/2 mediated signaling pathways such as activation of caspase 3 and apoptosis-related proteins, thus indicating that SFN-Cys might be a more promising therapeutic agent versus SFN to resist glioblastoma cells, especially in Taxol-resistant cancer cells.

Sulforaphane-cysteine suppresses invasion via downregulation of galectin-1 in human prostate cancer DU145 and PC3 cells.

Our previous study showed that sulforaphane (SFN) inhibits invasion in human prostate cancer DU145 cells; however, the underlying mechanisms were not profoundly investigated. In the present study, we found that sulforaphane-cysteine (SFN-Cys), as a metabolite of SFN, inhibits invasion and possesses a novel mechanism in prostate cancer DU145 and PC3 cells. The scratch and Transwell assays showed that SFN-Cys (15 µM) inhibited both migration and invasion, with cell morphological changes, such as cell shrinkage and pseudopodia shortening. The cell proliferation (MTS) assay indicated that cell viability was markedly suppressed with increasing concentrations of SFN­Cys. Furthermore, the Transwell assay showed that inhibition of SFN­Cys­triggered invasion was tightly linked to the sustained extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. Western blot analysis revealed that SFN-Cys downregulated galectin-1 protein, an invasion­related protein, and that the galectin­1 reduction could be blocked by ERK1/2 inhibitor PD98059 (25 µM). Moreover, immunofluorescence staining showed that the expression level of galectin-1 protein was significantly reduced in the cells treated with SFN­Cys. Hence, SFN­Cys­inhibited invasion resulted from the sustained ERK1/2 phosphorylation and ERK1/2­triggered galectin-1 downregulation, suggesting that galectin-1 is a new SFN-Cys target inhibiting invasion apart from ERK1/2, in the treatment of prostate cancer.

Culture strategies for lipid production using acetic acid as sole carbon source by Rhodosporidium toruloides.

Rhodosporidium toruloides AS 2.1389 was tested using different concentrations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20 g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions. At acetic acid concentrations as high as 20 g/L and the optimal carbon-to-nitrogen ratio (C/N) of 200 in a batch culture, the highest biomass production was 4.35 g/L, with a lipid content of 48.2%. At acetic acid concentrations as low as 4 g/L, a sequencing batch culture (SBC) with a C/N of 100 increased biomass production to 4.21 g/L, with a lipid content of 38.6%. These results provide usable culture strategies for lipid production by R. toruloides AS 2.1389 when using diverse waste-derived volatile fatty acids.

Sulforaphane inhibits invasion by phosphorylating ERK1/2 to regulate E-cadherin and CD44v6 in human prostate cancer DU145 cells.

Advanced prostate cancer has highly invasive potential, which may lead to metastasis associated with poor prognosis. Sulforaphane (SFN), abundant in cruciferous vegetables, exhibited effective resistance to carcinogenesis in a variety of tumors. The aim of the present study was to investigate whether SFN inhibited invasion in human prostate cancer cells via sustained activation of ERK1/2 and downstream signaling by an invasion assay, gelatin zymography and western blot analysis. The results showed that SFN inhibited invasion and we characterized the underlying mechanisms in human DU145 prostate cancer cells. SFN (15 µM) changed cell morphology leading to short­cell pseudopodia which may suppress tumor migration and invasion. The Transwell assay showed that SFN phosphorylated ERK1/2 in a dose- and time-dependent manner and significantly inhibited cell invasion, while the effect was reduced by the ERK1/2 blocker PD98059 (25 µM). Furthermore, these effects contributed to the upregulation of E-cadherin and the downregulation of CD44v6 and were eradicated by PD98059. Western blot analysis and gelatin zymography showed that SFN decreased the expression and activity of MMP-2. Thus, SFN inhibited invasion by activating ERK1/2 to upregulate E-cadherin and downregulate CD44v6, thereby reducing MMP-2 expression and activity. E-cadherin is an invasion inhibitor, while CD44v6 and MMP-2 are invasion promoters. Therefore, SFN is a prospective therapeutic agent that may be used to prevent invasion in prostate cancer.

Sulforaphane inhibits invasion via activating ERK1/2 signaling in human glioblastoma U87MG and U373MG cells.

BACKGROUND: Glioblastoma has highly invasive potential, which might result in poor prognosis and therapeutic failure. Hence, the key we study is to find effective therapies to repress migration and invasion. Sulforaphane (SFN) was demonstrated to inhibit cell growth in a variety of tumors. Here, we will further investigate whether SFN inhibits migration and invasion and find the possible mechanisms in human glioblastoma U87MG and U373MG cells. METHODS: First, the optimal time and dose of SFN for migration and invasion study were determined via cell viability and cell morphological assay. Further, scratch assay and transwell invasion assay were employed to investigate the effect of SFN on migration and invasion. Meanwhile, Western blots were used to detect the molecular linkage among invasion related proteins phosphorylated ERK1/2, matrix metalloproteinase-2 (MMP-2) and CD44v6. Furthermore, Gelatin zymography was performed to detect the inhibition of MMP-2 activation. In addition, ERK1/2 blocker PD98059 (25 µM) was integrated to find the link between activated ERK1/2 and invasion, MMP-2 and CD44v6. RESULTS: The results showed that SFN (20 µM) remarkably reduced the formation of cell pseudopodia, indicating that SFN might inhibit cell motility. As expected, scratch assay and transwell invasion assay showed that SFN inhibited glioblastoma cell migration and invasion. Western blot and Gelatin zymography showed that SFN phosphorylated ERK1/2 in a sustained way, which contributed to the downregulated MMP-2 expression and activity, and the upregulated CD44v6 expression. These molecular interactions resulted in the inhibition of cell invasion. CONCLUSIONS: SFN inhibited migration and invasion processes. Furthermore, SFN inhibited invasion via activating ERK1/2 in a sustained way. The accumulated ERK1/2 activation downregulated MMP-2 expression and decreased its activity and upregulated CD44v6. SFN might be a potential therapeutic agent by activating ERK1/2 signaling against human glioblastoma.