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

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

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

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

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

0

Glycine receptors (GlyRs) belong to the family of ligand-gated cys-loop receptors and effectuate fast inhibitory neurotransmission in central nervous system. They are involved in numerous physiological processes, such as movement, respiration and processing of sensory information, as well as in regulation of neuronal excitability in different brain regions. GlyRs play important role in the maintenance of excitatory/inhibitory balance in the hippocampus and participate in the development of various brain pathologies. In the present study we have examined a surface expression of GlyRs by pyramidal neurons and astrocytes in control and after 30 min of oxygen-glucose deprivation (OGD) in the organotypic culture of hippocampal slices. Our investigation has demonstrated a decrease in GlyR-positive staining associated with pyramidal neurons and relative stability of GlyRs expression at the surface of astrocytes 4 hs after OGD. These data indicate that GlyRs dysfunction may represent a significant additional factor leading to enhanced neuronal damage induced by OGD. Pharmacological modulation of GlyRs is a promising venue of research for the correction of negative consequences of oxygen-glucose deficiency.

0

The effects of load-induced interstitial fluid shear stress (FSS) on instantaneous signaling response of osteocytes (e.g., calcium signaling) have been well documented. FSS can also initiate the release of many important messenger molecules of osteocytes (e.g., ATP and PGE2 ). However, the effects of FSS on cellular function and bone metabolism-modulating cytokine expression of osteocytes have not been fully identified (some inconsistent/conflicting results have been documented). Herein, osteocyte-like MLO-Y4 cells were stimulated with 1 Pa, 2-hour FSS, and the effects of FSS on cellular morphology, cytoskeletal microstructure, biological activity, and gene and protein expression of important cytokines were investigated. SEM and cytoskeleton staining revealed that FSS induced well-organized cytoskeleton and increased filopodia processes. The osteocytic viability was sustained and apoptosis was inhibited via flow cytometry. FSS promoted Wnt3a and β-catenin gene and protein expression in 0-hour, 3-hour and 6-hour (sample collection time post FSS) groups. The FSS-stimulated cells in the 3-hour group exhibited more significant effects on the promotion of OCN and Cx43 and inhibition of DKK1 and SOST expression than the 0-hour and 6-hour groups. The 3-hour group with FSS stimulation also showed the most prominent effects on suppressing RANKL and RANKL/OPG gene and protein expression. This study revealed a direct regulatory effect of FSS on osteocytic morphology and apoptotic characteristics, and showed that osteocyte-secreted bone metabolism-modulating molecule expression was regulated by FSS in a time-dependent manner. This study not only enriches our basic knowledge for understanding osteocytic mechanotransduction, but also provides important evidence for more scientific experimental design.

0

Integrin αv β3 is a transmembrane integrin which can initiate osteoclasts' attachment on bone, leading to downward signaling pathways and subsequent bone resorption. Different calcium concentrations have reported to have influence on the activation of integrin αv β3 . To elucidate the regulatory mechanism of extracellular calcium concentrations on osteoclasts, a controlled micro flow plate (M04S) was utilized in the ONIX flow control system to observe osteoclasts' adhesion and migration in different calcium concentration medium. Fluorescent staining is conducted to show the distribution of integrin αv β3 and cytoskeleton reorganization. In addition, western blots were performed to detect the expression of integrin αv β3 and its downstream signaling pathways related to bone resorption. Also, real-time RT-PCR data of transcription co-activator (YAP/TAZ) and hydrolytic enzymes (the matrix metalloproteinase 9 and cathepsin K) is evaluated. Our findings suggest that osteoclasts' migration and adhesion is better promoted at 0.5 mM than 1.2 mM, which can be partly explained by the induced cytoskeleton organization via integrin αv β3 /Rho GTPase. But the activation and nuclear localization of YAP/TAZ, and the secretion of hydrolytic enzymes were upregulated when calcium concentration is at a higher level (1.2 mM). According to our study, there is a highly possibility that the migration and attachment of osteoclasts and subsequent osteoclastic bone resorption are regulated by a specific range of extracellular calcium concentration.

0

We investigated the dynamic changes in chromatin and microtubules at the first cell cycle in goat somatic cell nuclear transfer (SCNT)-derived and in vitro fertilization (IVF) derived embryos. Stage-dependent and characteristic changes to chromatin and microtubules occurred in SCNT-derived embryos at different times after activation. About half donor nuclei underwent premature chromosome condensation (PCC) at 1 h post activation, and furtherly reached telophase at 2 h after activation. However, we discovered that the separated chromosomes reaggregated, not keeping two independent nuclei; and formed one pronucleus at 2.5 h after activation. One pronucleus was found in all reconstructed oocytes except other no nucleus oocytes from 3 to 22 h after activation. Reconstructed oocytes reached the first mitotic metaphase at 23h post activation, which was later than that of IVF-derived embryos at 16 h after insemination. SCNT-derived embryos showed significantly higher abnormalities in the first mitotic metaphase spindle, compared with IVF-derived embryos. Abnormal spindles included multi polar and half spindles. SCNT-derived embryos began to cleave at 24h after activation, which was later than that of IVF-derived embryos at 21 h after insemination. SCNT-derived embryos showed delayed conversion from telophase to interphase than IVF-derived embryos during cleavage. These might lead to poor development in SCNT-derived embryos.

0

Transforming growth factor (TGF)-β1 is a multifunctional cytokine, which can control certain functions of various kinds of cells. However, it is unclear whether TGF-β1 affects T-cell migration in periodontal lesions. The aim of this study was to examine the effects of TGF-β1 on the production of C-C chemokine ligand (CCL)11, which is a T-helper 2-type chemokine, in human periodontal ligament cells (HPDLC). Interleukin (IL)-4 induced CCL11 production, but TGF-β1 did not, in HPDLC. However, TGF-β1 enhanced CCL11 production in IL-4-stimulated HPDLC. Western blot analysis showed that the signal transducer and activator of transcription 6 (STAT6) pathway was highly activated in HPDLC that had been stimulated with both IL-4 and TGF-β1. Mitogen-activated protein kinase activation did not differ between the HPDLC treated with a combination of IL-4 and TGF-β1 and those treated with IL-4 or TGF-β1 alone. Moreover, a STAT6 inhibitor significantly inhibited CCL11 production in HPDLC that had been stimulated with IL-4 and TGF-β1. The current study clearly demonstrated that TGF-β1 enhanced IL-4-induced CCL11 production in HPDLC. The STAT6 pathway is important for CCL11 production in IL-4- and TGF-β1-treated HPDLC.