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Results for “multifunction cell”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Y-box-binding protein-1 (YB-1) promotes cell proliferation, adhesion and drug resistance in diffuse large B-cell lymphoma

YB-1 is a multifunctional protein, which has been shown to correlate with resistance to treatment of various tumor types. This study investigated the expression and biologic function of YB-1 in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical analysis showed that the expression statuses of YB-1 and pYB-1{sup S102} were reversely correlated with the clinical outcomes of DLBCL patients. In addition, we found that YB-1 could promote the proliferation of DLBCL cells by accelerating the G1/S transition. Ectopic expression of YB-1 could markedly increase the expression of cell cycle regulators cyclin D1 and cyclin E. Furthermore, we found that adhesion of DLBCL cells to fibronectin (FN) could increase YB-1 phosphorylation at Ser102 and pYB-1{sup S102} nuclear translocation. In addition, overexpression of YB-1 could increase the adhesion of DLBCL cells to FN. Intriguingly, we found that YB-1 overexpression could confer drug resistance through cell-adhesion dependent and independent mechanisms in DLBCL. Silencing of YB-1 could sensitize DLBCL cells to mitoxantrone and overcome cell adhesion-mediated drug resistance (CAM-DR) phenotype in an AKT-dependent manner. - Highlights: • The expression statuses of YB-1 and pYB-1{sup S102} are reversely correlated with outcomes of DLBCL patients. • YB-1 promotes cell proliferation by accelerating G1/S transition in DLBCL. • YB-1 confers drug resistance to mitoxantrone in DLBCL.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Hyperglycemia-induced Bcl-2/Bax-mediated apoptosis of Schwann cells via mTORC1/S6K1 inhibition in diabetic peripheral neuropathy

Highlights: • Activation of mTOR prevents high glucose-induced apoptosis in Schwann cells. • The mTORC1 regulates high glucose-induced mitochondria-controlled apoptosis in Schwann cells. • Phosphorylation of S6K1 as mTORC1 downstream target affects high glucose-induced cell apoptosis in Schwann cells. Schwann cell apoptosis is one of the characteristics of diabetic peripheral neuropathy (DPN). The mammalian target of rapamycin (mTOR) is a multifunctional signaling pathway that regulates cell apoptosis in various types of tissues and cells. To investigate whether the mTOR pathway is involved in cell apoptosis in the Schwann cells of DPN, diabetic mice and rat Schwann cells (RSC96) were chosen to detect phospho-mTOR (Ser 2448), phospho-S6K1 (Thr 389), phospho-4EBP1 (Thr 37/46), Bcl-2, Bax and cleaved caspase-3 by diverse pathological and biological techniques. The results showed that phospho-mTOR (Ser 2448) was decreased in the sciatic nerves of diabetic mice, concomitant with decreased Bcl-2, increased Bax, cleaved caspase-3 and cell apoptosis. In addition, high glucose treatment for 72 h caused a 35.95% decrease in the phospho-mTOR (Ser 2448)/mTOR ratio, a 65.50% decrease in the phospho-S6K1 (Thr 389)/S6K1 ratio, a 3.67-fold increase in the Bax/Bcl-2 ratio and a 1.47-fold increase in the cleaved caspase-3/caspase-3 ratio. Furthermore, mTORC1 inhibition, rather than mTORC2 inhibition, resulted in mitochondrial controlled apoptosis in RSC96 cells by silencing RAPTOR or RICTOR. Again, suppression of the mTORC1 pathway by a chemical inhibitor led to mitochondrial controlled apoptosis in cultured RSC96 cells in vitro. By contrast, activation of the mTORC1 pathway with MHY1485 prevented decreased phospho-S6K1 (Thr 389) levels caused by high glucose and cell apoptosis. Additionally, constitutive activation of S6K1 avoided high glucose-induced cell apoptosis in RSC96 cells. In summary, our findings suggest that activating mTORC1/S6K1 signaling in Schwann cells may be a promising strategy for the prevention and treatment of DPN.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Exploring the Promise of Multifunctional “Zintl-Phase-Forming” Electrolytes for Si-Based Full Cells

Li-M-Si ternary Zintl phases have gained attention recently due to their high structural stability, which can improve the cycling stability compared to a bulk Si electrode. Adding multivalent cation salts (such as Mg 2+ and Ca 2+ ) in the electrolyte was proven to be a simple way to form Li-M-Si ternary phases in situ in Si-based Li-ion cells. To explore the promise of Zintl-phaseforming electrolytes, we systematically investigated their application in pouch cells via electrochemical and multiscale postmortem analysis. The introduction of multivalent cations, such as Mg 2+ , during charging can form Li x M y Si ternary phases. They can stabilize Si anions and reduce side reactions with electrolyte, improving the bulk stability. More importantly, Mg 2+ and Ca 2+ incorporate into interfacial side reactions and generate inorganic-rich solid- electrolyte interphase, thus enhancing the interfacial stability. Therefore, the full cells with Zintl-phase-forming electrolytes achieve higher capacity retentions at the C/3 rate after 100 cycles, compared to a baseline electrolyte. Additionally, strategies for mitigating the electrode-level fractures of Si were evaluated to make the best use of Zintl-phase-forming electrolytes. In conclusion, this work highlights the significance of synergistic impact of multifunctional additives to stabilize both bulk and interface chemistry in high-energy Si anode materials for Li-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2018

The core-shell-structured NaYF4:Er3+,Yb3+@NaYF4:Eu3+ nanocrystals as dual-mode and multifunctional luminescent mechanism for high-performance dye-sensitized solar cells

Highlights: • NaYF{sub 4}:Er{sup 3+},Yb{sup 3+}@NaYF{sub 4}:Eu{sup 3+} nanocrystals have been successfully prepared. • Higher quality NYFEY@NYFE with dual-mode emission was demonstrated. • The conversion efficiency of the DSSCs with NYFEY@NYFE reaches 7.37%. • Up-conversion luminescence was completed by Er{sup 3+} ions from infrared to visible light. • Down-conversion luminescence was fulfilled by Eu{sup 3+} ions from ultraviolet to visible light. - Abstract: The core-shell-structured NaYF{sub 4}:Er{sup 3+},Yb{sup 3+}@NaYF{sub 4}:Eu{sup 3+} (NYFEY@NYFE) nanocrystals with dual-mode emission have been satisfactorily prepared through a solvothermal method utilizing oleic acid and octadecene. From the emission spectra of dual-mode luminescent nanocrystals, it could be seen that nanocrystals consisted of two disparate units, one supplying up-converting luminescence excited with the 980 nm laser and the other providing down-converting luminescence by means of ultraviolet excitation, which are assigned to {sup 4}S{sub (3/2)} → {sup 4}I{sub (15/2)} transitions of Er{sup 3+} and {sup 5}D{sub 0} → {sup 7}F{sub 2} transitions of Eu{sup 3+}, separately. And then, a novel photoelectrode structure via introducing dual-mode luminescent materials was proposed. The photoelectric conversion efficiency of DSSCs with NYFEY@NYFE photoelectrode attains 7.37%, raised by a factor of 1.37 in comparison to that of the DSSCs without Eu{sup 3+} and Er{sup 3+} doping. The preparation of dual-mode NYFEY@NYFE not only has great significance to the study of material itself but its application in DSSCs, and can be also applied to other types of solar cells.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2025

Minimizing Energy Loss by Designing Multifunctional Solid Additives to Independent Regulation of Donor and Acceptor Layers for Efficient LBL Polymer Solar Cells

Solid additives are crucial in layer-by-layer (LBL) polymer solar cells (PSCs). Despite its importance, the simultaneous application of solid additives into both donor and acceptor layers has been largely overlooked. In this work, two multifunctional solid additives are actively designed, and investigated the synergistic effect on both donor and acceptor layers. Incorporating the multifunctional solid additives into the donor layer could effectively enhance the aggregation and molecular stacking of the donor polymer, leading to reduced energy disorder and minimizing ΔE 2 . When the multifunctional solid additives are introduced into the acceptor layer, they just play a role in optimizing the morphology, thereby reducing the ΔE 3 . Excitedly, the simultaneous addition of the multifunctional solid additives into both donor and acceptor layers produced a synergistic effect for decreasing ΔE 2 and ΔE 3 simultaneously, especially adding SA2, thus enabling an excellent power conversion efficiency (PCE) of 19.95% (certified as 19.68%) with an open-circuit voltage (V oc ) of 0.921 V, a short circuit current density (J sc ) of 27.08 mA cm -2 and a fill factor (FF) of 79.98%. The work highlights the potential of multifunctional solid additives in independently regulating the properties of donor and acceptor layers, which is expected as a promising approach for further developing higher performance PSCs.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Identification and functional characterization of three type III polyketide synthases from Aquilaria sinensis calli

Type III polyketide synthases (PKSs) play an important role in biosynthesis of various plant secondary metabolites and plant adaptation to environmental stresses. Aquilaria sinensis (A. sinensis) is the main plant species for production of agarwood, little is known about its PKS family. In this study, AsCHS1 and two new type III PKSs, AsPKS1 and AsPKS2, were isolated and characterized in A. sinensis calli. The comparative sequence and phylogenetic analysis indicated that AsPKS1 and AsPKS2 belonged to non-CHS group different from AsCHS1. The recombinant AsPKS1 and AsPKS2 produced the lactone-type products, suggesting their different enzyme activities from AsCHS1. Three PKS genes had a tissues-specific pattern in A. sinensis. Moreover, we examined the expression profiles of three PKS genes in calli under different abiotic stresses and hormone treatments. AsCHS1 transcript was most significantly induced by salt stress, AsPKS1 abundance was most remarkably enhanced by CdCl{sub 2} treatment, while AsPKS2 expression was most significantly induced by mannitol treatment. Furthermore, AsCHS1, AsPKS1 and AsPKS2 expression was enhanced upon gibberellins (GA3), methyl jasmonate (MeJA), or salicylic acid (SA) treatment, while three PKS genes displayed low transcript levels at the early stage under abscisic acid (ABA) treatment. In addition, three GFP:PKSs fusion proteins were localized in the cytoplasm and cell wall in Nicotiana benthamiana cells. These results indicated the multifunctional role of three type III PKSs in polyketide biosynthesis, plant resistance to abiotic stresses and signal transduction. - Highlights: • Two new PKS genes (AsPKS1 and AsPKS2) were isolated and characterized from A. sinensis. • The recombinant AsPKS1 and AsPKS2 catalyzed lactone-type products in vitro. • AsCHS1, AsPKS1 and AsPKS2 were involved in plant responses to abiotic stresses and hormone stimuli. • Our results also indicated that AsCHS1, AsPKS1 and AsPKS2 were predominantly localized in the cytoplasm and cell wall.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Multifunctional entinostat enhances the mechanical robustness and efficiency of flexible perovskite solar cells and minimodules

Flexible perovskite solar cells (F-PSCs), prized for their nature of soft and high power-weight compatibility, have attracted intensive attention. However, inferior buried perovskite-substrate interfaces due to low interfacial adhesion between perovskites and substrates and large deformation of flexible substrates have greatly limited the performance of F-PSCs. Here, we add organic molecule Entinostat (ET) into hole extraction material Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) to enhance the adhesion at the perovskite/substrate interface using the interactions of ET with perovskites, PTAA and indium tin oxide (ITO) through its multiple function groups. Meanwhile, ET added into perovskites reduces the voids at the bottom perovskite film, due to its capability to tune the crystallization of perovskites by forming adduct with lead. Consequently, the inverted small area F-PSCs achieved an efficiency of 23.4%. The flexible perovskite minimodule with an area of 9 cm 2 achieved an aperture efficiency of ~19.0% certified by National Renewable Energy Laboratory. Furthermore, the optimized unencapsulated flexible minimodule retained 84% of the initial efficiency after 5000 bending cycles and retained 90% of the initial PCE (T90) after light soaking for >750 hours.

14 SOLAR ENERGY↗
DOE OSTI2024

Multifunctional Nanofiber Reinforcement for Improved Thermomechanical and Chemical Stability of Perovskite Solar Cells

This project focused on the development of metal halide perovskite-polymeric nanofiber nanocomposites for robust and efficient solar cells. Metal halide perovskite solar cells are a potentially disruptive technology with high efficiencies and low-cost solution processability amenable with roll-to-roll fabrication of flexible devices. However, perovskites exhibit extreme brittleness, high internal film stresses, and chemical instabilities that significantly limit service lifetimes under normal operating conditions. To date, most work addressing these shortcomings has been focused on encapsulating devices between thick layers of rigid materials such as glass, which increases the total weight and cost of devices. Furthermore, these rigid and heavy encapsulants do not translate well to emerging solar markets vital for national security, including integrated mobile power, emergency deployments for disaster relief and military engagement, and lightweight power for space. It is therefore critical to improve the thermomechanical and chemical stability of perovskite devices in a way that is compatible with flexible and lightweight substrates. In this project, we integrated nylon-6,6 nanofibers into MAPbI3 to mechanically reinforce the perovskite, demonstrating films that exhibited fracture energies 5-fold greater than pristine MAPbI3 while also maintaining similar power conversion efficiencies due to beneficial light scattering effects from the polymeric nanofibers. These results required successful development of approaches to control the deposition thickness of nanofiber mats down to 100s of nanometers, and to ensure the polymer nanofibers did not inhibit charge transport to the at the perovskite-transport layer interface.

14 SOLAR ENERGY↗
DOE OSTI2019

Performance improvement of proton exchange membrane electrolyzer cells by introducing in-plane transport enhancement layers

Thin/tunable liquid/gas diffusion layers (TT-LGDLs) or porous transport layers (TT-PTLs), have exhibited superior multifunctional performance in proton exchange membrane electrolyzer cells (PEMECs), which can be attributed to their unique structures, such as planar surface, straight-through pores, thin thickness, etc. For achieving better PEMEC performance, TT-LGDLs with smaller pore size are desired. However, in this case, mass diffusion issues are brought in when some of the pores are covered by the flow field lands or shoulders. The coverage of the pores can lead to very high transport resistance, which may reduce the number of active oxygen evolution reaction sites, and therefore lower down the PEMEC performance. The in-plane transport enhancement layer for TT-LGDLs/PTLs are proposed to develop a dual-layer LGDL/PTL structure for improving the mass diffusion and the PEMEC performance. The results of this research reveal that the dual-layer LGDL/PTL structure exhibits smaller ohmic resistance and mass transport resistance, and therefore improve the PEMEC performance, without obvious changes in kinetic losses. The total ohmic resistance and mass transport resistance can be reduced by about 23% and 41%, respectively, with an ~830 um pore TT-LGDL/PTL stacking on a ~100 um pore TT-LGDL/PTL. The results indicate the feasibility of stacking the in-plane transport enhancement layer with large pore sizes onto a small pore TT-LGDLs/PTLs for high efficiency and low cost PEMEC practical applications.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2018

DDX1 regulates alternative splicing and insulin secretion in pancreatic β cells

DEAD-box helicase 1 (DDX1) is a multifunction protein involved in diverse cellular processes including transcription, viral replication, mRNA/miRNA processing, and tRNA splicing. Here, we report a novel function of DDX1 in mRNA alternative splicing in pancreatic β cells. By performing integrated data analysis of high-throughput RNA sequencing (RNA-Seq), and cross-linking and immunoprecipitation coupled with deep sequencing (CLIP-Seq), we identify hundreds of alternative splicing genes that are targeted by DDX1. These DDX1-targeted alternative splicing genes are mainly associated with calcium ion binding, high voltage-gated calcium channel, and transmembrane transporter. Functionally, silencing DDX1 impairs calcium influx and insulin secretion in the pancreatic β cells. These results reveal an important role for DDX1 in the regulation of gene alternative splicing and insulin secretion in pancreatic β cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2011

Extraribosomal Functions Associated with the C Terminus of the 37/67 kDa Laminin Receptor are Required for Maintaining Cell Viability

The 37/67 kDa laminin receptor (LAMR) is a multifunctional protein, acting as an extracellular receptor, localizing to the nucleus, and playing roles in rRNA processing and ribosome assembly. LAMR is important for cell viability; however, it is unclear which of its functions are essential. We developed a silent mutant LAMR construct, resistant to siRNA, to rescue the phenotypic effects of knocking down endogenous LAMR, which include inhibition of protein synthesis, cell cycle arrest, and apoptosis. In addition, we generated a C-terminal-truncated silent mutant LAMR construct structurally homologous to the Archaeoglobus fulgidus S2 ribosomal protein and missing the C-terminal 75 residues of LAMR, which displays more sequence divergence. We found that HT1080 cells stably expressing either silent mutant LAMR construct still undergo arrest in the G{sub 1} phase of the cell cycle when treated with siRNA. However, the expression of full-length silent mutant LAMR rescues cell viability, whereas the expression of the C-terminal-truncated LAMR does not. Interestingly, we also found that both silent mutant constructs restore protein translation and localize to the nucleus. Our findings indicate that the ability of LAMR to regulate viability is associated with its C-terminal 75 residues. Furthermore, this function is distinct from its role in cell proliferation, independent of its ribosomal functions, and may be regulated by a nonnuclear localization.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2011

Testin, a novel binding partner of the calcium-sensing receptor, enhances receptor-mediated Rho-kinase signalling

Highlights: {yields} A yeast two-hybrid screen revealed testin bound to the calcium-sensing receptor. {yields} The second zinc finger of LIM domain 1 of testin is critical for interaction. {yields} Testin bound to a region of the receptor tail important for cell signalling. {yields} Testin and receptor interaction was confirmed in mammalian (HEK293) cells. {yields} Overexpression of testin enhanced receptor-mediated Rho signalling in HEK293 cells. -- Abstract: The calcium-sensing receptor (CaR) plays an integral role in calcium homeostasis and the regulation of other cellular functions including cell proliferation and cytoskeletal organisation. The multifunctional nature of the CaR is manifested through ligand-dependent stimulation of different signalling pathways that are also regulated by partner binding proteins. Following a yeast two-hybrid library screen using the intracellular tail of the CaR as bait, we identified several novel binding partners including the focal adhesion protein, testin. Testin has not previously been shown to interact with cell surface receptors. The sites of interaction between the CaR and testin were mapped to the membrane proximal region of the receptor tail and the second zinc-finger of LIM domain 1 of testin, the integrity of which was found to be critical for the CaR-testin interaction. The CaR-testin association was confirmed in HEK293 cells by coimmunoprecipitation and confocal microscopy studies. Ectopic expression of testin in HEK293 cells stably expressing the CaR enhanced CaR-stimulated Rho activity but had no effect on CaR-stimulated ERK signalling. These results suggest an interplay between the CaR and testin in the regulation of CaR-mediated Rho signalling with possible effects on the cytoskeleton.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

CD147-induced cell proliferation is associated with Smad4 signal inhibition

CD147 is a multifunctional trans-membrane glycoprotein, which is highly expressed in many cancers. However, the mechanism by which CD147 modulates cell proliferation is not fully understood. The aim of this study is to investigate the role of CD147 in cell proliferation associated with the TGF-β/Smad4 signaling pathway. Here, we used cell viability and clone formation assays in LNCaP prostate cancer cells to demonstrate that CD147 promotes cell proliferation. The luciferase assay and western blotting show that silencing CD147 using shRNA enhances transcription and expression of p21{sup WAF1}. Using immunofluorescence and nuclear-cytoplasmic separation, we show that this is primarily attributed to transport of Smad4 from the cytoplasm to nucleus. Other assays (GST pull-down, co-immunoprecipitation and immunofluorescence) demonstrate that Smad4 is a new interaction partner of CD147, with the Smad4 MH2 domain and CD147 intracellular domain (CD147-ICD) being involved in the interaction. Furthermore, we report that a phosphoserine (pSer) in CD147 (pSer252) is responsible for this interaction and inhibition of the Smad4/p21{sup WAF1} signal that promotes cell proliferation. Our results provide a novel molecular mechanism for CD147-induced cell proliferation associated with Smad4 signal inhibition. - Highlights: • Smad4 interacts with CD147 via the MH2 domain. • CD147 prevents Smad4 translocation into the nuclear to regulate p21 transcription. • CD147 inhibits p21 transcription and expression independent on p53. • pCD147-S252 is responsible for interaction with Smad4 and p21 down-regulation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Small interfering RNA targeting ILK inhibits metastasis in human tongue cancer cells through repression of epithelial-to-mesenchymal transition

Integrin-linked kinase (ILK) is a multifunctional serine/threonine kinase. Accumulating evidences suggest that ILK are involved in cell–matrix interactions, cell proliferation, invasion, migration, angiogenesis and Epithelial–mesenchymal transition (EMT). However, the underlying mechanisms remain largely unknown. EMT has been postulated as a prerequisite for metastasis. The reports have demonstrated that EMT was implicated in metastasis of oral squamous cell carcinomas. Therefore, here we further postulate that ILK might participate in EMT of tongue cancer. We showed that ILK siRNA inhibited EMT with low N-cadherin, Vimentin, Snail, Slug and Twist as well as high E-cadherin expression in vivo and in vitro. We found that knockdown of ILK inhibited cell proliferation, migration and invasion as well as changed cell morphology. We also demonstrated that ILK siRNA inhibited phosphorylation of downstream signaling targets Akt and GSK3β as well as reduced expression of MMP2 and MMP9. Furthermore, we found that the tongue tumor with high metastasis capability showed higher ILK, Vimentin, Snail, Slug and Twist as well as lower E-cadherin expression in clinical specimens. Finally, ILK siRNA led to the suppression for tumorigenesis and metastasis in vivo. Our findings suggest that ILK could be a novel diagnostic and therapeutic target for tongue cancer. Highlights: • ILK siRNA influences cell morphology, cell cycle, migration and invasion. • ILK siRNA affects the expression of proteins associated with EMT. • ILK expression is related to EMT in clinical human tongue tumors. • ILK siRNA inhibits metastasis of the tongue cancer cells through suppressing EMT.

60 APPLIED LIFE SCIENCES↗