SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Cell biology international

27

To examine cytokine production in response to RSV infection, we assessed the levels of 29 cytokines released from RSV-infected human foetal lung fibroblasts. We also examined the relationships between the effects of fluticasone propionate and various signalling pathways in the cells. Twenty-four hours after infection (1MOI), RSV-infected cells released cytokines, for example proinflammatory cytokines (IL-1β, IL-6 and TNF-α), anti-inflammatory (IL-1ra), Th1 (IFN-γ, IFN-λ1a, IL-2 and IL-12), Th2 (IL-4, IL-5, IL-10 and IL-13), granulopoiesis-inducing (G-CSF and GM-CSF), eosinophil recruitment-inducing (eotaxin and RANTES) and neutrophil recruitment-inducing cytokines (IL-8, IP-10, MCP-1 and MIP-1α). Aberrant release of most was significantly suppressed by fluticasone propionate. Twelve hours after RSV infection, increased phosphorylation of Akt, p38 MAPK, ERK1/2 and IκB-α was noted. Fluticasone propionate suppressed the phosphorylation of Akt, p38 MAPK, and ERK1/2, but not IκB-α, in virus-infected cells. TLR-4 expression was unchanged in control and RSV-infected cells, and TLR-3 and RIG-I expression was not detected. The results indicate that RSV infection induces aberrant production and release of certain cytokines through these signalling pathways in human lung fibroblasts. Overproduction and imbalance of these cytokines may be associated with the pathophysiology of RSV-induced excessive and allergic inflammation.

Concepts: Cytokines, Chemokine, Inflammation, Signal transduction, Interleukin, Immune system, Cytokine, Asthma

24

MicroRNA-455 (miRNA-455), which is downregulated in human cancer, potently mediates the multiple steps of carcinogenesis. However, the role of miR-455 in non-small cell lung cancer (NSCLC) carcinogenesis remains unclear. In present study, we determined the mature miRNA-455 expression in NSCLC tissues and cells by real-time PCR. Follow-up studies examined the effects of a miR-455 mimic (gain of function) on cell proliferation, migration and invasion. Our data indicate that miR-455 was significantly down-regulated in NSCLC cell lines and tissues. In functional assays, overexpression of miR-455 suppressed the proliferation, migration and invasion of NSCLC cell lines. Data from reporter assays showed that miR-455 directly binds to 3'UTR of ZEB1 and suppresses the endogenous level of ZEB1 protein expression. Furthermore, overexpression of ZEB1 reverses miR-455-suppressed malignant phenotype of NSCLC cells. Moreover, we found that upregulation of ZEB1 expression is inversely associated with miR-455 expression in NSCLC tissues. Taken together, miR-455 as an anti-oncogene in non-small cell lung cancer through up-regulation of ZEB1 and serve as a potential therapeutic target in NSCLC.

Concepts: DNA replication, Evolution, Gene, Gene expression, DNA, Non-small cell lung carcinoma, Lung cancer, Cancer

22

Parkinson’s disease (PD), the second-most prevalent neurodegenerative disease, is primarily characterized by neurodegeneration in the substantia nigra pars compacta, resulting in motor impairment. Loss-of-function mutations in parkin are the major cause of the early-onset familial form of the disease. Although rodents deficient in parkin (parkin(-/-)) have some dopaminergic system dysfunction associated with central oxidative stress and energy metabolism deficiencies, these animals only display nigrostriatal pathway degeneration under inflammatory conditions. This study investigated the impact of the inflammatory stimulus induced by lypopolisaccharide (LPS) on tetrahydrobiopterin (BH4) synthesizing enzymes (de novo and salvage pathways), since this cofactor is essential for dopamine synthesis. The mitochondrial content and architecture was investigated in the striatum of LPS-exposed parkin(-/-) mice. As expected, the LPS (0.33 mg / kg; i.p.) challenge compromised spontaneous locomotion and social interaction with juvenile parkin(-/-) and WT mice. Moreover, the genotype impacted the kinetics of the investigation of the juvenile. The inflammatory scenario did not induce apparent changes in mitochondrial ultrastructure; however, it increased the quantity of mitochondria, which were of smaller size, and provoked the perinuclear distribution of the organelle. Furthermore, the BH4 de novo biosynthetic pathway failed to be up-regulated in the LPS challenge, a well-known stimulus for its activation. The LPS treatment increased sepiapterin reductase (SPR) expression, suggesting compensation by the salvage pathway. This might indicate that dopamine synthesis is compromised in parkin(-/-) mice under inflammatory conditions. Finally, this scenario impaired the striatal expression of the transcription factor BDNF, possibly favoring cell death.

Concepts: Oxidative phosphorylation, Striatum, Genetics, Adenosine triphosphate, Metabolism, Parkinson's disease, Dopamine, Substantia nigra

3

Colorectal cancer is one of the global causes of cancer deaths. Cancer stem cells (CSCs) inside the tumour niche responsible for metastasis and relapses, and hence need to be targeted for cancer therapeutics. Although dietary fibre and lifestyle changes have been recommended as measures for colorectal cancer prevention, no such recommendations are available for using water soluble vitamins as prophylaxis measure for colorectal cancers. High dose of Vitamin C has been proven to selectively kill colon cancer cells having BRAF and KRAS mutations by inducing oxidative stress. In this study, we show for the first time the opposing effects of the low and high dose of Vitamin C and vitamin B3 on colon CSCs isolated from HT- 29 and HCT-15 colorectal carcinoma cell lines. At small doses, both of these vitamins exerted a cell proliferative effect only on CSCs, while there was no change in the proliferation status of non-stem cancer cells and wild-type (WT) populations. On the other hand, the death effects induced by high doses of Vitamin C and B3 were of the order of 50-60% and ∼30% on CSCs from HT-29 and HCT15 respectively. Interestingly, the control fibroblast cell line (NIH3T3) was highly refractory all the tested concentrations of Vitamin C and B3, except for the highest dose- 10,000 µg of Vitamin C that induced only 15% of cell death. Hence, these results indicate the future scope of use of therapeutic doses of Vitamin C and B3 especially in patients with advanced colorectal cancer.

Concepts: Cell biology, Ulcerative colitis, Hereditary nonpolyposis colorectal cancer, Constipation, Colon, Vitamin, Cancer, Colorectal cancer

2

Sutherlandia frutescens is a medicinal plant, traditionally used to treat various types of human diseases, including cancer. Previous studies of several botanicals link suppression of prostate cancer growth with inhibition of the Gli/hedgehog (Gli/Hh) signaling pathway. Here we hypothesized the anti-cancer effect of S. frutescens was linked to its inhibition of the Gli/Hh signaling in prostate cancer. We found a dose- and time-dependent growth inhibition in human prostate cancer cells, PC3 and LNCaP, and mouse prostate cancer cell, TRAMP-C2, treated with S. frutescens methanol extract (SLE). We also observed a dose-dependent inhibition of the Gli-reporter activity in Shh Light II and TRAMP-C2QGli cells treated with SLE. In addition, SLE can inhibit Gli/Hh signaling by blocking Gli1 and Ptched1 gene expression in the presence of a Gli/Hh signaling agonist (SAG). A diet supplemented with S. frutescens suppressed the formation of poorly differentiated carcinoma in prostates of TRAMP mice. Finally, we found Sutherlandioside D was the most potent compound in the crude extract that could suppress Gli-reporter in Shh Light II cells. Together, this suggests that the S. frutescens extract may exert anti-cancer effect by targeting Gli/Hh signaling, and Sutherlandioside D is one of the active compounds.

Concepts: Radiation therapy, Gene, Metastasis, Obesity, Disease, Gene expression, Prostate cancer, Cancer

0

Trophoblast cells play a vital role in embryo implantation. Exploring cytokines secreted by trophoblast cells will be significant in revealing the molecular mechanism of embryo implantation. In vitro-cultured trophoblast cells treated with Lefty revealed that Lefty could downregulate the expression of Nodal while promoting the expression of MMP-2 and MMP-9. Thus, Lefty may promote the proliferation and invasion of trophoblast cells, thereby reducing the amount of apoptosis of these cells. Lefty siRNA knockdown or overexpression of Nodal showed opposite effects to treatment with Lefty. When trophoblast cells overexpressing Nodal were treated with Lefty, Nodal expression increased, and MMP-2 and MMP-9 expression was still promoted. Additionally, the proliferation and invasion of trophoblast cells were upregulated, and trophoblast apoptosis was reduced. Together, these data reveal that Lefty can promote the proliferation and invasion of trophoblast cells and inhibit their apoptosis by downregulating Nodal expression while promoting the expression of MMP-2 and MMP-9. This finding provides new proof for the mechanism of trophoblast cell invasion in decidua.

Concepts: Endometrium, DNA, Pregnancy, Embryo, Developmental biology, Cell, Implantation, Gene expression

0

This study aimed to investigate the effects of triggering receptor expressed on myeloid cell-2 (TREM2) on the production of pro-inflammatory mediators and cytokines induced by lipopolysaccharide (LPS) in BV2 microglia. TREM2 expression or TREM2-specific siRNA were used to induce TREM2 overexpression or silencing. The BV2 cells were pre-treated with the PI3K inhibitor of LY294002 for1 h and stimulated with LPS for 24 h. Then, the cell viability, apoptosis, phagocytosis, nitric oxide (NO), lactate dehydrogenase (LDH) and cytokine production, as well as the activation of AKT and NF-kB were determined, respectively. We found LPS stimulation significantly reduced BV2 cell viability, enhanced BV2 cell phagocytosis and apoptosis compared to the control groups. In addition, LPS stimulation significantly increased the production of NO, LDH, TNF-α, IL-1β, and the activation of AKT and NF-kB, while decreased the levels of IL-10 and TGF-β1. However, these pro-inflammatory effects were significantly attenuated by TREM2 overexpression or pre-treatment with LY294002, while enhanced by TREM2 silencing. Thus, we concluded that TREM2 inhibited neuroinflammation by down-regulating PI3K/AKT and NF-kB signaling in BV2 microglia. Above all, therapeutic enhanced TREM2 expression may be a new strategy for intervention of neuroinflammatory diseases.

Concepts: Vesicle, Apoptosis, Lactate dehydrogenase, Hormone, Signal transduction, Cytokine, Phosphoinositide 3-kinase, Gene expression

0

Growing evidences have demonstrated alternative splicing makes great contribution to tumor metastasis since multiple protein isoforms from a single gene that often display different functions in the cell. Human manganese superoxide dismutase (hMnSOD) was revealed dysregulation in progress of tumor metastasis, while the effect of hMnSOD isoforms on metastasis remained unclear. In this study, we showed a novel truncated hMnSOD isoform hMnSOD183, which lacked 39 amino acids compared with hMnSOD222. We expressed two hMnSOD protein isoforms in E.coli respectively and found that the MnSOD activity of truncated hMnSOD isoform was especially weaker. In 95-D cells, mRNA levels of hMnSOD variants and MnSOD activity were significantly increased than that in A549 cells. Furthermore, the hMnSODc exhibited lower mRNA level than hMnSODa/b in A549 and 95-D cells. Additionally, the effects of two isoforms were assessed about cell invasion, overexpression of hMnSOD222 but not hMnSOD183 promoted 95-D cells metastasis, and hMnSOD knockdown significantly reduced cells metastatic behavior. Overexpression of hMnSOD isoforms also caused changes of metastasis associated proteins, such as up-regulation of MMPs, VEGF and Vimentin and down-regulation of E-cadherin. Moreover, overexpression of hMnSOD183 had weaker effect on metastasis related signaling proteins, such as Akt, JNK and IKKβ, compared to hMnSOD222. In conclusion, our study identified that hMnSOD isoforms induce tumor metastasis through Akt-JNK-IKKβ signaling pathways and the hMnSOD183 isoform played a weaker role than hMnSOD222 in tumor metastasis. Characterization of hMnSOD isoforms is useful for future investigation on metastasis of lung cancer cells.

Concepts: Proteins, Alternative splicing, Metastasis, Gene expression, Protein, Superoxide dismutase, Lung cancer, Cancer

0

The aim of this study was to investigate the underlying mechanisms of hypoxia-induced apoptosis of GC-2spd (GC-2) cells. The GC-2 cells were treated with or without hypoxia for 12, 24, 48 and 72 h. Apoptosis of GC-2 cells was detected using TUNEL and flow cytometry. Fluorescence microscopic was used to observe the autophagy of GC-2 cells. Hypoxia-inducible factor-1alpha (HIF-1α), apoptosis-related protein and marker protein of autophagy levels were measured by Western blotting. Hypoxia induced apoptosis and autophagy of GC-2 cells, and increased expression of HIF-1α, LC3-II, Beclin-1 and pro-apoptotic protein, but reduced p62 and anti-apoptotic protein level. Meanwhile, hypoxia-induced HIF-1α mediated expression of apoptosis and autophagy- related protein in GC-2 cell. Furthermore, autophagy regulated hypoxia-induced apoptosis of GC-2 cell. Our data suggest that hypoxia induces apoptosis of GC-2 cell by activation of autophagy involving activation of the apoptosis signaling pathway under the hypoxic condition.

Concepts: Programmed cell death, Enzyme, Laboratory techniques, Protein, DNA, Gene, Molecular biology, Cell biology

0

MicroRNAs (miRNAs ) play key roles in cervical cancer metastasis progression. Accumulated evidences have revealed that miRNAs are related to the pathophysiological process. However, the role of miR-340 in cervical cancer and how it works is still not fully interpreted. Using qRT-PCR to examine the expression of miR-340 in cervical cancer tissues. Transwell migration and invasion experiments were used to detect the role of miR-340 in migration and invasion. Luciferase reporter assay, qRT-PCR and Western blot were used to detect the relationship between miR-340 and EphA3. Using Transwell migration and invasion experiments to investigate the role of EphA3 on migration and invasion. Restoration expriments were also performed. Western blot was used to assay the influence of miR-340 and EphA3 on EMT. We found that miR-340 was downregulated in cervical cancer tissues compared with the normal tissues. Transwell migration and invasion experiments indicated that overexpression of miR-340 frequently inhibited the migration and invasion of cervical cancer cells. EphA3 is a target of miR-340, and ectopic expression of EphA3 can promote the migration and invasion of cervical cancer cells, whereas restoration of EphA3 in miR-340-overexpressing cervical cancer cells reversed the suppressive effects of miR-340. What’s more, the process of migration and invasion which regulated by miR-340/EphA3 was depended on adjusting the EMT way. These findings indicate that miR-340 may act as an anti-tumor factor during the process of tumor metastasis through targeting EphA3, suggesting that miR-340 might be a potential new diagnostic and therapeutic molecule for the treatment of cervical cancer.

Concepts: Prostate cancer, Lung cancer, Breast cancer, Gene expression, Cancer, Oncology, Cervical cancer, Metastasis