13,500 research outputs found
Mechanotransduction of mitochondrial AMPK and its distinct role in flow-induced breast cancer cell migration
The biophysical microenvironment of the tumor site has significant impact on breast cancer progression and metastasis. The importance of altered mechanotransduction in cancerous tissue has been documented, yet its role in the regulation of cellular metabolism and the potential link between cellular energy and cell migration remain poorly understood. In this study, we investigated the role of mechanotransduction in AMP-activated protein kinase (AMPK) activation in breast cancer cells in response to interstitial fluid flow (IFF). Additionally, we explored the involvement of AMPK in breast cancer cell migration. IFF was applied to the 3D cell-matrix construct. The subcellular signaling activity of Src, FAK, and AMPK was visualized in real-time using fluorescent resonance energy transfer (FRET). We observed that breast cancer cells (MDA-MB-231) are more sensitive to IFF than normal epithelial cells (MCF-10A). AMPK was activated at the mitochondria of MDA-MB-231 cells by IFF, but not in other subcellular compartments (i.e., cytosol, plasma membrane, and nucleus). The inhibition of FAK or Src abolished flow-induced AMPK activation in the mitochondria of MDA-MB-231 cells. We also observed that global AMPK activation reduced MDA-MB-231 cell migration. Interestingly, specific AMPK inhibition in the mitochondria reduced cell migration and blocked flow-induced cell migration. Our results suggest the linkage of FAK/Src and mitochondria-specific AMPK in mechanotransduction and the differential role of AMPK in breast cancer cell migration depending on its subcellular compartment-specific activation
Correlation evolution and monogamy of two geometric quantum discords in multipartite systems
We explore two different geometric quantum discords defined respectively via
the trace norm (GQD-1) and Hilbert-Schmidt norm (GQD-2) in multipartite
systems. A rigorous hierarchy relation is revealed for the two GQDs in a class
of symmetric two-qubit -shape states. For multiqubit pure states, it is
found that both GQDs are related to the entanglement concurrence, with the
hierarchy relation being saturated. Furthermore, we look into a four-partite
dynamical system consisting of two cavities interacting with independent
reservoirs. It is found that the GQD-2 can exhibit various sudden change
behaviours, while the GQD-1 only evolves asymptotically, with the two GQDs
exhibiting different monogamous properties.Comment: 5 pages, 3 figure
Incentive effect of structural tax reduction policy on consumption upgrading and high-tech industry
China is implementing a structural tax reduction policy to
upgrade the structure of household consumption and promote
the development of high-tech industry. This article constructs a
heterogeneous NK-DSGE (New Keynesian - Dynamic Stochastic
General Equilibrium) model to study the effects of tax reduction
policies on consumption upgrading and the development of
high-tech industry. The tax categories involved in this model are
divided into demand-side tax and supply-side tax. We build two
indexes to measure the consumption structure and the development
of high-tech industry. It is found that reducing high-tech
enterprise income tax would upgrade the consumption structure
and promote the development of high-tech industries in the short
term. Reducing low-tech enterprise income tax would achieve
similar effects in the medium and long term. Moreover, tax such
as consumption tax, labour income tax and capital income tax
reduction policies can upgrade the consumption structure and
promote the development of high-tech industry in the long term.
Finally, this article finds that when the elasticity of labour substitution
is smaller, reducing high-tech enterprise income tax is
more effective
Influence of miR155 on allergic conjunctivitis in mice via regulation of NF-κB signal pathway
Purpose: To investigate the effect of miR-155 on allergic conjunctivitis (AC) in mice, and to elucidate the mechanism of action.
Methods: Sixty (60) Balb/c mice were randomly divided into three groups with 20 mice per group. Ovalbumin (OVA) was used to induce experimental model of AC in mice. Mice in the AC+miR-155 siRNA group were given miR-SiRNA once daily for 2 weeks before inducing AC. The expressions of miR-155 in conjunctival tissue of the control and AC groups were assayed with reverse transcriptionpolymerase chain reaction (RT-PCR). In addition, anti-OVA IgE antibody, eotaxin, IL-13 and IFN-γ levels were determined using ELISA (enzyme-linked immunosorbent assay). The regulatory effect of miR-155 on the NF-κB signal pathway in mice conjunctiva tissue with AC was determined using immunoblotting.
Results: Higher miR-155 expression was seen in serum of AC group than in that of control group (p < 0.05). Inhibition of miR-155 mitigated AC-induced pathological injury, reduced infiltration of eosinophils, lowered serum levels of anti-AVO IgE antibody eotaxin and Il-13, and increased IFN-γ level (p < 0.05). Phosphorylation of P65 of conjunctiva tissue of AC mice was blocked after inhibition of miR-155.
Conclusion: The inhibition of miR-155 ameliorates AC in mice most likely via a mechanism related to the inhibition of phosphorylation of P65. This provides a theoretical basis for new drug research and development
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