Cellular Skeleton Research Articles

Mechanical evaluation of multi-continuous interpenetrating phase composites based on Schwarz Primitive cellular structure

Interpenetrating phase composites (IPCs) have been extensively promoted due to their robust mechanical properties. To further obtain the enhanced properties and elucidate the underlying mechanical mechanism, we designed and manufactured the tri-continuous IPCs by filling hyperelastic PDMS into a 3D-printed Schwarz Primitive (P) cellular skeleton based on the viscoplastic polymer. Subsequently, the compressive properties, cyclic properties, and relaxation properties of the IPCs were experimentally investigated. Results demonstrated that interpenetrating can improve the compressive properties, reduce the relaxation behavior, and weaken the cyclic softening effect. By incorporating a user material subroutine in simulations, we analyzed the deformation behaviors of P cellular material and IPCs. Through a combination of experimental observations and simulated outcomes, we refined our understanding of the deformation mechanism of IPCs. Our analysis revealed that filled PDMS played a positive role in enhancing the mechanical performance of TC-IPCs through three key mechanisms: Firstly, it shears part of the external load of TC-IPCs. Secondly, it astricts the bending deformation in the skeleton, thereby preventing the stress drop induced by buckling. Thirdly, the interaction between PDMS and P cellular skeleton puts them in compressive stress in tri-direction, enhancing the overall mechanical properties. These findings contribute to advancing the development and application of IPCs.

Identifying disulfidptosis subtypes in hepatocellular carcinoma through machine learning and preliminary exploration of its connection with immunotherapy

BackgroundHepatocellular carcinoma (HCC) is a highly prevalent and deadly cancer, with limited treatment options for advanced-stage patients. Disulfidptosis is a recently identified mechanism of programmed cell death that occurs in SLC7A11 high-expressing cells due to glucose starvation-induced disintegration of the cellular disulfide skeleton. We aimed to explore the potential of disulfidptosis, as a prognostic and therapeutic marker in HCC.MethodsWe classified HCC patients into two disulfidptosis subtypes (C1 and C2) based on the transcriptional profiles of 31 disulfrgs using a non-negative matrix factorization (NMF) algorithm. Further, five genes (NEIL3, MMP1, STC2, ADH4 and CFHR3) were screened by Cox regression analysis and machine learning algorithm to construct a disulfidptosis scoring system (disulfS). Cell proliferation assay, F-actin staining and PBMC co-culture model were used to validate that disulfidptosis occurs in HCC and correlates with immunotherapy response.ResultsOur results suggests that the low disulfidptosis subtype (C2) demonstrated better overall survival (OS) and progression-free survival (PFS) prognosis, along with lower levels of immunosuppressive cell infiltration and activation of the glycine/serine/threonine metabolic pathway. Additionally, the low disulfidptosis group showed better responses to immunotherapy and potential antagonism with sorafenib treatment. As a total survival risk factor, disulfS demonstrated high predictive efficacy in multiple validation cohorts. We demonstrated the presence of disulfidptosis in HCC cells and its possible relevance to immunotherapeutic sensitization.ConclusionThe present study indicates that novel biomarkers related to disulfidptosis may serve as useful clinical diagnostic indicators for liver cancer, enabling the prediction of prognosis and identification of potential treatment targets.Graphical

Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment.

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the β-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

Construction of macroporous MOF-derived single leaf-like cellular skeleton for boosting advanced oxidation processes

A single leaf-like cellular NiCoOv skeleton derived from macroporous–microporous ZIF-L crystal is synthesized, with enhanced mass transfer and rich active sites for boosting the catalytic activity towards advanced oxidation processes.

Synergistic Multilevel Sieving Membranes: Integrating Cellular Graphene Skeleton with Continuous MOFs Nanolayer for Superior Multiphase Water Separation

AbstractThe emergence of MOF–based separation membranes has transformed liquid contaminant filtration with impressive sieving properties. However, their use in multiphase water filtration is hindered by a limited sieving range and susceptibility to collapse in solution. To address this challenge, an innovative solution is presented: the Multilevel Cellular Graphene Skeleton (MCGK) induced by femtosecond laser, onto which a continuous MOF nanolayer (CMN), specifically ZIF–8, is grown. This forms a groundbreaking multistage micron/nanocomposite pore membrane. The MCGK/CMN membrane significantly expands the range of filterable contaminants and enhances stability. It utilizes a multilevel, multi–pore size sieving strategy for effective multiphase water filtration, achieving an impressive 90% efficiency in self–driven solar steam generation sieving. Additionally, it excels in removing organic pollutants and over 80% of volatile organic compounds (VOCs), while reducing metal ion concentrations. In liquid pressure–driven filtration, it achieves complete oil adsorption and reduces VOCs and metal ion concentrations. This innovative multistage micron/nanocomposite pore membrane holds great potential for diverse practical applications and provides insights for next–generation nanofiltration membranes, promising more efficient and resilient water purification technologies in the future.

Stable Plating and Stripping of Lithium Metal Anodes through Space Confinement and Stress Regulation.

Lithium metal anodes suffer from enormous mechanical stress derived from volume changes during electrochemical plating and stripping. The utilization of derived stress has the potential for the dendrite-free deposition and electrochemical reversibility of lithium metal. Here, we investigated the plating and stripping process of lithium metal held within a cellular three-dimensional graphene skeleton decorated with homogeneous Ag nanoparticles. Owing to appropriate reduction-splitting and electrostatic interaction of nitrogen dopants, the cellular skeletons show micron-level pores and superior elastic property. As lithium hosts, the cellular skeletons can physically confine the metal deposition and provide continuous volume-derived stress between Li and collectors, thus meliorating the stress-regulated Li morphology and improving the reversibility of Li metal anodes. Consequently, the symmetrical batteries exhibit a stable cycling performance with a span life of more than 1900 h. Full batteries (NCM811 as cathodes) achieve a reversible capacity of 181 mA h g-1 at 0.5 C and a stable cycling performance of 300 cycles with a capacity retention of 83.5%. The meliorative behavior of lithium metal within the cellular skeletons suggests the advantage of a stress-regulating strategy, which could also be meaningful for other conversion electrodes with volume fluctuation.

The daf-7(e1372) mutation rescues dauer formation defects seen in C. elegans unc-33 mutants.

Collapsin response mediator protein-2 (CRMP2) in humans, UNC-33 in C. elegans, is a molecule that mediates axonal outgrowth and stability. UNC-33/CRMP2 has been hypothesized as a potential drug target for treating Alzheimer's and other neurodegenerative diseases, which can often be attributed in part to aging. In aging, CRMP2 becomes hyperphosphorylated, which decreases the protein's functionality, destabilizes the cellular skeleton, and contributes to neurodegeneration. In C. elegans, aging can be slowed by entering dauer diapause; a non-aging developmental stage turned on when the DAF-7/TGFβ signaling pathway is silenced in response to environmental stressors. In our laboratory, we discovered that unc-33 mutants are unable to form dauers in response to environmental stressors, but the mechanism behind this is still unknown. Here, we present a study that investigates whether a mutation in the daf-7 gene which leads to a temperature sensitive constitutive dauer phenotype can rescue phenotypes characteristic of unc-33 mutants. To this end, we created unc-33; daf-7 double mutants and quantified proper dauer formation after exposure to unfavorable environmental conditions. In addition, we tested how the introduction of the daf-7 mutation would affect the locomotion of the double mutants on an agar plate and a liquid medium. Furthermore, we examined axonal elongation of the double mutants using a transgene, juIs76, which expresses GFP in GABAergic motor neurons. Our analysis of unc-33; daf-7 double mutants showed that introducing the daf-7 mutation into an unc-33 mutant rescued dauer formation. However, further studies revealed that the unc-33; daf-7 double mutants had defects in axonal outgrowth of their D-type motor neuron which had been previously seen in unc-33 single mutants and impaired locomotion. Based on these results, we concluded that unc-33 mutants might have a problem suppressing DAF-7 signaling under unfavorable environmental conditions, leading to the activation of reproductive programs and the development of adults instead of dauers.

Encapsulating ultrafine Fe3O4 nanoparticles into interconnected 3D multiporous carbon for superior Li-ion energy storage

Although Fe3O4 has low cost and high theoretical capacity, its low electrical conductivity and significant volume changes during the reaction process result in poor electrochemical performance, particularly cycling performance, which limit its application as anode materials. To overcome these limitations, this study created Fe3O4@3D cellular carbon composites (Fe3O4@3D cellular carbon: Fe3O4@3D-CC) by homogeneously embedding ultrafine Fe3O4 nanoparticles of size around 10 nm in a three-dimensional cellular carbon skeleton using a template-assisted method. The porous structure enables for large volumes of electrolyte to be stored and features a dual continuous transport channel for ions and electrons, which can considerably improve the conductivity of the Fe3O4. Furthermore, 3D cellular carbon locks Fe3O4 nanoparticles, allowing them to adapt to volume changes during charge-discharge process and preventing structural degradation. Due to the aforementioned structural properties, this material has a first discharge-specific capacity of 2534 mA h g−1 at a rate of 0.1 C and can still reach 1011 mA h g−1 after 400 cycles at a high rate of 2 C. This keeps the theoretical capacity at 109 % and distinctly enhances the electrochemical performance of Fe3O4, particularly the cycling performance.

Interfacial bonding mechanism and mechanical properties of adding CuZn alloy fibre for Cu/Al composite

The heterogeneous interface constituted by Cu and Al were diffusion-bonded with CuZn alloy fibre interlayer under different bonding parameters, which was compared with directly bonded Cu/Al interface to analyze the effects of the different intermetallic compounds (IMCs) occurred at the joining interface on the interface mechanical properties. The interface microstructure was analyzed by scanning electron microscope (SEM), the compositions profiles across the joining interface were measured by energy dispersive spectroscopy (EDS), the phase and grain in the bonding interface of a Cu/Al bond were carefully investigated via electron backscatter diffraction technique (EBSD), the results show that the interface phase of Cu/Al composites grows irregularly, which leads to the low uniformity of interface properties. By adding CuZn alloy fibre, the interface of Cu/Al shows cellular skeleton and promotes the uniform diffusion of interface. When the bonding time was 570 °C for 60 min, the average shear strength of Cu/CuZn/Al interface reached 60.7 MPa. Compared with Cu/Al interface, the standard deviation of shear strength decreased from 18.7 to 1.6, and the variance decreased from 3.7 to 1.1. • The diffusion of Cu and Al was promoted by the introduction of Zn. • CuZn alloy can improve the interface homogeneity of large area Cu/Al composites. • When CuZn alloy fibre was added, the fracture mode changed to mixed fracture. • The bonding time has a great effect on the uniformity of the interface.

Magneto-inductive open-cell cellular carbon composites with activated carbon as guest phase: Guefoams for energy-efficient VOCs management

Guefoams (guest-containing foams) are a new-class of open-cell cellular materials that extend the properties of conventional foams by incorporating guest phases that convert them into multifunctional materials. This manuscript describes the development of pitch-derived composite guefoams that contain two types of inclusions: iron nanoparticles embedded in the cellular skeleton and activated carbon particles as guest phases. The activated carbon particles significantly increase the specific surface area and gas adsorption capacity. When these materials are exposed to low-intensity magnetic fields, the iron nanoparticles confer a high magneto-inductive capacity that enables ultrafast heating and rapid desorption of adsorbed species. The ability of these materials to act as preconcentrators for volatile organic compounds (VOCs) is demonstrated in this work using toluene as a proof of concept. The Guefoams developed here have greater preconcentration capabilities than current state-of-the-art systems while also being significantly more energy efficient due to the magnetic induction controlled desorption process. This unparalleled blend of properties makes these guefoams a valuable tool for energy-efficient VOCs management.

Integrated Transcriptome Analysis Reveals the Impact of Photodynamic Therapy on Cerebrovascular Endothelial Cells.

Blood vessels in the brain tissue form a compact vessel structure and play an essential role in maintaining the homeostasis of the neurovascular system. The low dosage of photodynamic intervention (PDT) significantly affects the expression of cellular biomarkers. To understand the impact of photodynamic interventions on cerebrovascular endothelial cells, we evaluated the dosage-dependent impact of porfimer sodium-mediated PDT on B.END3 cells using flow cytometer, comet assay, RNA sequencing, and bioinformatics analysis. To examine whether PDT can induce disorder of intracellular organelles, we did not observe any significance damage of DNA and cellular skeleton. Moreover, expression levels of cellular transporters-related genes were significantly altered, implying the drawbacks of PDT on cerebrovascular functions. To address the potential molecular mechanisms of these phenotypes, RNA sequencing and bioinformatics analysis were employed to identify critical genes and pathways among these processes. The gene ontology (GO) analysis and protein-protein interaction (PPI) identified 15 hub genes, highly associated with cellular mitosis process (CDK1, CDC20, MCM5, MCM7, MCM4, CCNA2, AURKB, KIF2C, ESPL1, BUB1B) and DNA replication (POLE2, PLOE, CDC45, CDC6). Gene set enrichment analysis (GSEA) reveals that TNF-α/NF-κB and KRAS pathways may play a critical role in regulating expression levels of transporter-related genes. To further perform qRT-PCR assays, we find that TNF-α/NF-κB and KRAS pathways were substantially up-regulated, consistent with GSEA analysis. The current findings suggested that a low dosage of PDT intervention may be detrimental to the homeostasis of blood-brain barrier (BBB) by inducing the inflammatory response and affecting the expression of surface biomarkers.

Brownian dynamics simulation of protofilament relaxation during rapid freezing.

Electron cryo-microscopy (Cryo-EM) is a powerful method for visualizing biological objects with up to near-angstrom resolution. Instead of chemical fixation, the method relies on very rapid freezing to immobilize the sample. Under these conditions, crystalline ice does not have time to form and distort structure. For many practical applications, the rate of cooling is fast enough to consider sample immobilization instantaneous, but in some cases, a more rigorous analysis of structure relaxation during freezing could be essential. This difficult yet important problem has been significantly under-reported in the literature, despite spectacular recent developments in Cryo-EM. Here we use Brownian dynamics modeling to examine theoretically the possible effects of cryo-immobilization on the apparent shapes of biological polymers. The main focus of our study is on tubulin protofilaments. These structures are integral parts of microtubules, which in turn are key elements of the cellular skeleton, essential for intracellular transport, maintenance of cell shape, cell division and migration. We theoretically examine the extent of protofilament relaxation within the freezing time as a function of the cooling rate, the filament's flexural rigidity, and the effect of cooling on water's viscosity. Our modeling suggests that practically achievable cooling rates are not rapid enough to capture tubulin protofilaments in conformations that are incompletely relaxed, suggesting that structures seen by cryo-EM are good approximations to physiological shapes. This prediction is confirmed by our analysis of curvatures of tubulin protofilaments, using samples, prepared and visualized with a variety of methods. We find, however, that cryofixation may capture incompletely relaxed shapes of more flexible polymers, and it may affect Cryo-EM-based measurements of their persistence lengths. This analysis will be valuable for understanding of structures of different types of biopolymers, observed with Cryo-EM.

Why Cytoskeletal Associated Proteins are Important in Colorectal Cancer Patients: Molecular & Bioinformatic Analysis

Introduction: It has been aimed to analyze the role of pathogenic effects of mutation and expression anomalies occurring on diaphanous-related formin 1 (DIAPH1), WASP actin nucleation-promoting factor (WASP), myosin heavy chain 9 (MYH9), actinin alpha 1 (ACNT1), filamin A (FLNA), and tubulin beta 1 class VI (TUBB1), which are known as fundamental cellular skeleton proteins, on the development and progression of cancer via bioinformatic tools. Methods: The genome sequence and expression profiles of 594 Colorectal Cancer (CRC) patients were obtained via bioinformatic tools, which provide data for The Cancer Genome Atlas. The mutation patterns of six genes were determined in detail, and for the prediction of pathogenic properties of identified changes for CRC, Polymorphism Phenotyping v2, Screening for Non-Acceptable Polymorphisms, and the Catalogue Of Somatic Mutations In Can- cer were utilized. Apart from the mutation profile, the effects of existing mutations on messenger ribonucleic acid (mRNA) expression and survival were also identified. Moreover, the Search Tool for the Retrieval of Interacting Genes/Proteins network analysis was realized to further comprehend the functional relations of proteins in cellu- lar processes. Results: There have been 142 distinct point mutations, gene amplification, and deep deletions identified on DIAPH1, WAS, MYH9, ACNT1, FLNA, and TUBB1 genes. ACTN1 and FLNA low mRNA expression levels for DIAPH1 increased, and the mRNA expression level was statistically significant (p<0.05). Prognosis-wise, the effect of mRNA expression on survival in the absence of disease was meaningful for FLNA (p=0.011). Discussion and Conclusion: Bioinformatic analysis data in DIAPH1, WASP, MYH9, ACNT1, FLNA, and TUBB1 genes, which are important in CRC pathogenesis revealed in this study, will be a guide for future laboratory studies.

Extracorporeal shock wave therapy: an update.

Extracorporeal shock wave therapy (ESWT) is a safe therapy and there are only a few side effects known (such as pain during ESWT and minor haematomata), but no severe complications are to be expected if it is performed as recommended.Contraindications are severe coagulopathy for high-energy ESWT, and ESWT with focus on the foetus or embryo and focus on severe infection.The effect mechanism of ESWT is still a component of diverse studies, but as far as we can summarize today, it is a similar process to a cascade triggered by mechano-transduction: mechanical energy causes changes in the cellular skeleton, which provokes a reaction of the cell core (for example release of mRNA) to influence diverse cell structures such as mitochondria, endoplasmic reticulum, intracellular vesicles, etc., so the enzymatic response leads to the improvement of the healing process.The usage of ESWT should be taught, to improve the outcome. Courses should be organized by national societies, since the legal framework conditions are different from one country to another.In this update the musculoskeletal indications are addressed (mainly bone and tendons): pseudoarthrosis, delayed fracture healing, bone marrow oedema and osteonecrosis in its early stages, insertional tendinopathies such as plantar fasciitis and Achilles tendon fasciitis, calcifying tendonitis of the rotator cuff, tennis elbow, and wound healing problems.Cite this article: EFORT Open Rev 2020;5:584-592. DOI: 10.1302/2058-5241.5.190067

Easily route to control density of polyimide foams and impact on mechanical and combustion behaviors

Polyimide foams (PIFs) with different density are rapidly formed basing on water foaming technology of multi-anhydride and multi-isocyanate system in airtight mold. Density of PIFs is controlled by easily route that regulate the ratio of main components total mass and mold cavity volume. Polyimide proportion of PIFs of different series is adjusted by refilled multi-anhydride method. Analyses curves show that density exerts minimal effect on molecular structure of PIFs in the same series. In all series, cellular shapes gradually change from polyhedral to spherical and cellular skeletons become thicker and thicker with the increasing of PIFs density, and the increase in density leads to an obviously enhancement in mechanical properties, including a nearly 300% increase in compression strength, and compression modulus shows an approximately linear growth trend with an increase rate of 6–8 Pa/g. Moreover, the Fourier transform infrared (FT-IR) spectra and thermal gravimetric analysis (TGA) curves show that the density of foams makes slight effect on the molecular structure of the matrix resin in the same series. In all series, flame retardance is also improved with increase in foam density because of the thicker char layer, especially inflected by obviously decrease in peak of heat release rate (PHRR) curves and peak of smoke production rate (PSPR), but increase in limiting oxygen index (LOI) value is only 1–4%. Meanwhile, the effect of density on combustion behavior decrease with the increase in polyimide proportion.

Enhanced bi-layer mosaic armor: experiments and simulation

Three different alumina/aluminum bi-layer armors having different striking faces, i.e., monolithic alumina, mosaic alumina, and mosaic alumina enhanced by aluminum honeycomb, were fabricated and tested under the impact of the flat projectile. The ballistic performance of each armor type was also investigated using three-dimensional (3D) finite element (FE) simulations. Upon validating the FE simulation results with experimental measurements, the ballistic limit velocity and failure mechanisms for each type of armor, as well as the influence of ceramic tile size, impact position, border effect, and inter tile gap width were quantified. For the enhanced mosaic armor, the metallic honeycomb lattice performed as a cellular skeleton to confine the ceramic tiles and fragments, leading to enhanced ballistic resistance. Besides, the honeycomb enhanced mosaic armor was also found to have much improved multi-hit ballistic resistance in comparison with monolithic and mosaic alumina. The honeycomb preserved the structural integrity of the mosaic armor so that a high level of residual ballistic resistance remained even after impact. With the extended reliability calculation method, single shot ballistic data were used to estimate the performance of the honeycomb enhanced mosaic armor under multiple projectile impacts.

Chiral CuxCoyS Nanoparticles under Magnetic Field and NIR Light to Eliminate Senescent Cells

In the present study, chiral Cux Coy S nanoparticles (NPs) were developed to selectively induce apoptosis of senescent cells using both an alternating magnetic field (AMF) and near infrared (NIR) photon illumination. The chiral effects on living cells were investigated, and d-Cux Coy S NPs showed about 2.5 times higher of internalized ability than l-NPs. By modifying beta 2 macroglobulin (MG), senescent cells were effectively eliminated by d-Cux Coy S NPs without damaging the activities of normal cells under AMF and photon illumination. Compared to the individual application of NIR illumination and AMF, their synergistic effect induced the production of caspase-3 with a much shorter treatment time and higher efficiency due to the more serious photon-induced cellular redox and mechanical damage of cellular skeleton. Moreover, the developed strategy was successfully used to remove senescent cells in vivo. This study developed a controllable way of regulating cell activities using chiral NPs, which will provide a valuable way for treating diseases and promoting health.

Chiral CuxCoyS Nanoparticles under Magnetic Field and NIR Light to Eliminate Senescent Cells

AbstractIn the present study, chiral CuxCoyS nanoparticles (NPs) were developed to selectively induce apoptosis of senescent cells using both an alternating magnetic field (AMF) and near infrared (NIR) photon illumination. The chiral effects on living cells were investigated, and d‐CuxCoyS NPs showed about 2.5 times higher of internalized ability than l‐NPs. By modifying beta 2 macroglobulin (MG), senescent cells were effectively eliminated by d‐CuxCoyS NPs without damaging the activities of normal cells under AMF and photon illumination. Compared to the individual application of NIR illumination and AMF, their synergistic effect induced the production of caspase‐3 with a much shorter treatment time and higher efficiency due to the more serious photon‐induced cellular redox and mechanical damage of cellular skeleton. Moreover, the developed strategy was successfully used to remove senescent cells in vivo. This study developed a controllable way of regulating cell activities using chiral NPs, which will provide a valuable way for treating diseases and promoting health.

Vimentin Intermediate Filaments as Potential Target for Cancer Treatment.

Intermediate filaments constitute the third component of the cellular skeleton. Unlike actin and microtubule cytoskeletons, the intermediate filaments are composed of a wide variety of structurally related proteins showing distinct expression patterns in tissues and cell types. Changes in the expression patterns of intermediate filaments are often associated with cancer progression; in particular with phenotypes leading to increased cellular migration and invasion. In this review we will describe the role of vimentin intermediate filaments in cancer cell migration, cell adhesion structures, and metastasis formation. The potential for targeting vimentin in cancer treatment and the development of drugs targeting vimentin will be reviewed.

Identification and characterization of the TCA cycle genes in maize

BackgroundThe tricarboxylic acid (TCA) cycle is crucial for cellular energy metabolism and carbon skeleton supply. However, the detailed functions of the maize TCA cycle genes remain unclear.ResultsIn this study, 91 TCA genes were identified in maize by a homology search, and they were distributed on 10 chromosomes and 1 contig. Phylogenetic results showed that almost all maize TCA genes could be classified into eight major clades according to their enzyme families. Sequence alignment revealed that several genes in the same subunit shared high protein sequence similarity. The results of cis-acting element analysis suggested that several TCA genes might be involved in signal transduction and plant growth. Expression profile analysis showed that many maize TCA cycle genes were expressed in specific tissues, and replicate genes always shared similar expression patterns. Moreover, qPCR analysis revealed that some TCA genes were highly expressed in the anthers at the microspore meiosis phase. In addition, we predicted the potential interaction networks among the maize TCA genes. Next, we cloned five TCA genes located on different TCA enzyme complexes, Zm00001d008244 (isocitrate dehydrogenase, IDH), Zm00001d017258 (succinyl-CoA synthetase, SCoAL), Zm00001d025258 (α-ketoglutarate dehydrogenase, αKGDH), Zm00001d027558 (aconitase, ACO) and Zm00001d044042 (malate dehydrogenase, MDH). Confocal observation showed that their protein products were mainly localized to the mitochondria; however, Zm00001d025258 and Zm00001d027558 were also distributed in the nucleus, and Zm00001d017258 and Zm00001d044042 were also located in other unknown positions in the cytoplasm. Through the bimolecular fluorescent complimentary (BiFC) method, it was determined that Zm00001d027558 and Zm00001d044042 could form homologous dimers, and both homologous dimers were mainly distributed in the mitochondria. However, no heterodimers were detected between these five genes. Finally, Arabidopsis lines overexpressing the above five genes were constructed, and those transgenic lines exhibited altered primary root length, salt tolerance, and fertility.ConclusionSequence compositions, duplication patterns, phylogenetic relationships, cis-elements, expression patterns, and interaction networks were investigated for all maize TCA cycle genes. Five maize TCA genes were overexpressed in Arabidopsis, and they could alter primary root length, salt tolerance, and fertility. In conclusion, our findings may help to reveal the molecular function of the TCA genes in maize.