Vinculin Expression Research Articles

Vinculin presents unfavorable prediction in ovarian cancer and prevents proliferation and migration of ovarian cancer cells.

The influences of Vinculin on many cancers were blurry, including ovarian cancer. Thus, we concentrated on the efficient role of Vinculin in ovarian cancer and explored the potential mechanism(s). Expression of Vinculin in ovarian cancer tissues and cell lines was investigated by real-time polymerase chain reaction, immunohistochemistry, and Western blot. The Kaplan-Meier manner with the logrank was performed to assess overall survival. We further evaluated the relations between Vinculin expression and clinicopathological features of ovarian cancer. Moreover, Vinculin was overexpressed or silenced by respectively transfection with pcDNA-Vinculin or small interfering (si-Vinculin) into human ovarian cancer cell line Caov3 or human ovarian epithelial cell line (HOEpiC). Thereafter, cell viability, cell apoptosis, and migration were checked by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, flow cytometer, and scratch assay, respectively. Likewise, the apoptosis- and migration-related proteins were distinguished by Western blot. Compared to the nontumor tissues or HOEpiC cells, Vinculin was significantly lower expressed in the ovarian cancer tissues and cells. Furthermore, we found out that Vinculin was primarily distributed at the cell membrane and cytoplasm. Moreover, Vinculin was negatively associated with International Federation of Gynecology and Obstetrics stage, grade, and distant metastasis. Overexpression of Vinculin dramatically weakened cell viability and migration and stimulated apoptosis. Conversely, suppression of Vinculin showed opposite results. Vinculin presents unfavorable prediction in ovarian cancer and inhibits ovarian cancer proliferation and migration.

Hypergravity Reduces Astrocyte Migration by Altering Cytoskeletal Dynamics

Glial scar formation through astrocytes impairs neural regeneration following spinal cord injury, head trauma, or stroke. Astrocyte migration towards the lesion and induction of a reactive astroglial phenotype require dynamic cytoskeletal protein rearrangements. In this glial cell model, hypergravity was used to alter cytoskeletal dynamics, i.e. stabilizing microtubules while destabilizing actin filaments. We hypothesize that increased gravitational (mechanical) loading by means of centrifugation (hypergravity) modulates in vitro astrocyte function in a way that could reduce their potential for scar formation.We exposed primary murine cortical astrocytes to 2g using two types of custom‐designed hypergravity platforms at DLR (Cologne, Germany) and assessed a variety of parameters important for glial scarring in vitro. The platforms unlike commercial laboratory centrifuges model physiological hypergravity and allow for cell cultivation and live‐cell imaging. Primary astrocytes were isolated from wildtype (C57BL/6J) as well as transgenic LifeAct‐GFP mice and subjected to increased gravitational load. We measured cell proliferation and survival, after 7 days of exposure to 2g, as well as spreading and migration rate online for 24h. We visualized morphological features, cytoskeletal actin filament dynamics, reactivity markers and investigated expression levels of focal adhesion‐related proteins.The exposure to 2g hypergravity induced a decrease in cell spreading (20%) coincidental with an inhibited migratory behavior (40%) and altered cytoskeletal dynamics. Astrocytic proliferation and survival were not affected. The expression of the focal adhesion marker vinculin was increased by 70–80%.We conclude that hypergravity attenuates astrocyte spreading and migration. These parameters are crucial for glial scar formation, while basic cellular processes, such as proliferation and apoptosis were unchanged. The response appears to be mediated through altered cytoskeletal dynamics and may provide targets for therapies promoting neuronal regeneration.

Size-Dependent Effects of Suspended Graphene Oxide Nanoparticles on the Cellular Fate of Mouse Neural Stem Cells.

PurposeIn this study, we aim to explore the effects of graphene oxide (GO), a derivative of graphene, nanoparticles of four different sizes on the cellular fate of mouse neural stem cells (mNSCs).MethodsGO NPs were characterized with transmission electron microscopy (TEM), scanning electron micrography (SEM), atomic force microscopy (AFM) and Raman Spectra analysis. The cytotoxic effects of the GO NPs of different sizes on the mNSCs were determined using CCK-8 assay, Annexin V-APC/ 7-AAD staining and EdU staining assays. We investigated the biological and the mechanisms of GO NPs on cells using immunofluorescence analysis and quantitative real-time PCR (qPCR).ResultsThe average hydrodynamic sizes of the GO NPs were 417 nm, 663 nm, 1047 nm, and 4651 nm, with a thickness of approximately 22.5 nm, 17.7 nm, 22.4 nm, and 13.4 nm, respectively. GO NPs of all sizes showed low cytotoxicity at a concentration of 20 μg/mL on the mNSCs. Immunostaining demonstrated that treatment with GO NPs, especially the 663 nm ones, enhanced the self-renewal ability of mNSCs in the absence of EGF and bFGF. Under differentiation medium conditions that are free of mitogenic factors, all the GO NPs, particularly the 4651 nm ones, increased the expression level of Tuj1 and GFAP. With regards to the migration ability, we found that 417 nm GO-NP-treated mNSCs migrated over a longer distance than the control group obviously. In addition, higher expression of Rap1, Vinculin and Paxillin was observed in the GO NP-treated groups compared to the control group. mRNA-Sequence analysis and Western blotting results suggested that the 4651 nm GO NPs triggered positive neuronal differentiation through phosphorylation of ERK1/2 by the downregulating of TRPC2.ConclusionGO NPs play an important role in the applications of inducing self-renewal and differentiation of mNSC, and are promising in the future for further studies.

UHMWPE-MWCNT-nHA based hybrid trilayer nanobiocomposite: Processing approach, physical properties, stem/bone cell functionality, and blood compatibility.

The development of polymeric nanocomposites for biomedical applications remains a major challenge in terms of tailored addition of nanoparticles to realize the simultaneous enhancement of fracture resistance and cell/blood compatibility. To address this, the present work has been planned to determine whether small addition of surface functionalized multiwalled-carbon-nanotube, MWCNT (<1.5 wt%) and egg-shell derived nanosized hydroxyapatite, nHA (<10 wt%) to ultrahigh-molecular-weight-polyethylene (UHMWPE) can significantly improve the physical properties as well as biocompatibility. The difference in mouse osteoblast and human mesenchymal stem cell (hMSc) proliferation has been validated using both the monolithic composite and a trilayered composite with two different UHMWPE nanocomposites on either face with pure polymer at the middle. The combination of rheology and micro-CT with fractography reveals the homogeneous dispersion of nanofillers, leading to mechanical property enhancement. The quantitative analysis of cell viability and cell spreading by immunocytochemistry method, using vinculin and vimentin expression, establish significant cytocompatibility with hMSc and osteoblast cells onto the trilayer hybrid nanobiocomposite substrates. The hemocompatibility of the investigated composites under the controlled flow of rabbit blood in a microfluidic device reveals the signature of reduced thrombogenesis with reduction of platelet activation on UHMWPE nanocomposite w.r.t. unreinforced UHMWPE. An attempt has been made to discuss the blood compatibility results in the backdrop of the bovine serum albumin adsorption kinetics. Summarizing, the present study establishes that the twin requirement of mechanical property and cyto/hemo-compatibility can be potentially realized in developing trilayer composites in UHMWPE-nHA-MWCNT system.

Effect of focal adhesion kinase inhibition on osteoblastic cells grown on titanium with different topographies.

Objective The present study aimed to investigate the participation of focal adhesion kinases (FAK) in interactions between osteoblastic cells and titanium (Ti) surfaces with three different topographies, namely, untreated (US), microstructured (MS), and nanostructured (NS).Methodology Osteoblasts harvested from the calvarial bones of 3-day-old rats were cultured on US, MS and NS discs in the presence of PF-573228 (FAK inhibitor) to evaluate osteoblastic differentiation. After 24 h, we evaluated osteoblast morphology and vinculin expression, and on day 10, the following parameters: gene expression of osteoblastic markers and integrin signaling components, FAK protein expression and alkaline phosphatase (ALP) activity. A smooth surface, porosities at the microscale level, and nanocavities were observed in US, MS, and NS, respectively.ResultsFAK inhibition decreased the number of filopodia in cells grown on US and MS compared with that in NS. FAK inhibition decreased the gene expression of Alp, bone sialoprotein, osteocalcin, and ALP activity in cells grown on all evaluated surfaces. FAK inhibition did not affect the gene expression of Fak, integrin alpha 1 ( Itga1 ) and integrin beta 1 ( Itgb1 ) in cells grown on MS, increased the gene expression of Fak in cells grown on NS, and increased the gene expression of Itga1 and Itgb1 in cells grown on US and NS. Moreover, FAK protein expression decreased in cells cultured on US but increased in cells cultured on MS and NS after FAK inhibition; no difference in the expression of vinculin was observed among cells grown on all surfaces.Conclusions Our data demonstrate the relevance of FAK in the interactions between osteoblastic cells and Ti surfaces regardless of surface topography. Nanotopography positively regulated FAK expression and integrin signaling pathway components during osteoblast differentiation. In this context, the development of Ti surfaces with the ability to upregulate FAK activity could positively impact the process of implant osseointegration.

BPC 157 Promotes Skeletal Muscle Cells Migration in Association with Up-regulation of Paxillin and Vinculin Expression

BPC 157 Promotes Skeletal Muscle Cells Migration in Association with Up-regulation of Paxillin and Vinculin Expression

Tunable Adhesion of Different Cell Types Modulated by Thermoresponsive Polymer Brush Thickness.

Tunable adhesion of different cell types on well-defined surfaces has attracted common interests in the field of biomaterial science and surface engineering. Herein, we demonstrate a new strategy for the regulation of cell adhesion by simply controlling the thickness of thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) brushes via surface-initiated atom transfer radical polymerization (ATRP). The adhesion of different cell types (4T1, HEK293, H9C2, HUVEC, and L929) can be easily modulated by varying the thickness of PNIPAAm brushes from 5.9 ± 1.0 nm (PN1) to 69.0 ± 5.0 nm (PN6). The fluorescent staining of different cell types on a variety of surfaces reveals that the thickness of PNIPAAm brushes would regulate the assembly of F-actin and the expression of vinculin and fibronectin, which are essential in regulating the adherent status of cells. Moreover, the cellular morphologies revealed that the adherent cells are well-spread, and multiple pseudopod extensions and protrusions can be observed at the margin of cells. This work provides a facile strategy for regulating tunable adhesion of different cell types, which may find applications in tissue engineering and regenerative medicine.

Effects of cyclic fluid stress at different frequencies on behaviors of cells incubated on titanium alloy

The orthopedic external fixation is always in dynamic mechanical environment with the somatic movement. We used a self-designed mini oscillator to simulate this condition by providing the reciprocating cyclic fluid stress, and observed the behavioral responses of fibroblasts implanted on titanium alloy plane to the stress at different frequencies, including 0.2 Hz, 0.6 Hz, and 1.0 Hz. We found that the cell angle, shape index and expression of vinculin were mostly biphasic-dependent with the increase of frequency, with peaks at 0.6 Hz. Whereas the cell area, expression of Col-I and α-SMA were mainly affected by the 1.0 Hz stress. Interestingly, 1.0 Hz stress also promoted Col-I expression of bone marrow mesenchymal stem cells (BMSCs), although it did not increase α-SMA. These results reveal that 0.6 Hz stress improves the alignment, polarity and adherence of fibroblasts on titanium alloy substrates, thus improving the sealing of implants; the 1.0 Hz force activates the differentiation of fibroblasts into myofibroblasts and increases collagen produced by stem cells, which probably cause the formation of fibrous capsules around implants.

The Effect of PEGDE Concentration and Temperature on Physicochemical and Biological Properties of Chitosan.

Chitosan (CHT) is a polysaccharide with multiple claimed properties and outstanding biocompatibility, generally attributed to the presence of protonable amino groups rendering a cationic natural polymer. However, the effect of changes in CHT structure due to hydration is not considered in its performance. This study compares the effects on biocompatibility after drying at 25 °C and 150 °C scaffolds of chitosan, polyethylene glycol diglycidyl ether (PEGDE) crosslinked CHT (low, medium and high concentration) and glutaraldehyde (GA) crosslinked CHT. PEGDE crosslinked CHT showed a reduction in free amino groups and the amide I/II ratio, which exhaustive drying reduced further. In X-ray diffraction (DRX) analysis, PEGDE crosslinked CHT showed multiple peaks, whereas the crystallinity percentage was reduced with an increase in PEGDE concentration and thermal treatments at 150 °C. In a direct contact cell assay, high osteoblast viability was achieved at low and medium PEDGE concentrations, which was improved when the crosslinked scaffolds were thermally treated at 150 °C. This was attributed to its partial hydrophilicity, low crystallinity and low surface roughness; this in spite of the small reduction in the amount of free amino groups on the surface induced during drying at 150 °C. Furthermore, PEGDE crosslinked CHT scaffolds showed strong vinculin and integrin 1β expression, which render them suitable for bone contact applications.

Bnip3 regulates airway smooth muscle cell focal adhesion and proliferation.

Increased airway smooth muscle (ASM) mass is a key contributor to airway narrowing and airway hyperresponsiveness in asthma. Besides conventional pathways and regulators of ASM proliferation, recent studies suggest that changes in mitochondrial morphology and function play a role in airway remodeling in asthma. In this study, we aimed at determining the role of mitochondrial Bcl-2 adenovirus E1B 19 kDa-interacting protein, Bnip3, in the regulation of ASM proliferation. Bnip3 is a member of the Bcl-2 family of proteins critical for mitochondrial health, mitophagy, and cell survival/death. We found that Bnip3 expression is upregulated in ASM cells from asthmatic donors compared with that in ASM cells from healthy donors and transient downregulation of Bnip3 expression in primary human ASM cells using an siRNA approach decreased cell adhesion, migration, and proliferation. Furthermore, Bnip3 downregulation altered the structure (electron density) and function (cellular ATP levels, membrane potential, and reacitve oxygen species generation) of mitochondria and decreased expression of cytoskeleton proteins vinculin, paxillin, and actinin. These findings suggest that Bnip3 via regulation of mitochondria functions and expression of adhesion proteins regulates ASM adhesion, migration, and proliferation. This study reveals a novel role for Bnip3 in ASM functions and establishes Bnip3 as a potential target in mitigating ASM remodeling in asthma.

Argon plasma modification promotes adipose derived stem cells osteogenic and chondrogenic differentiation on nanocomposite polyurethane scaffolds; implications for skeletal tissue engineering.

Bone and cartilage craniofacial defects due to trauma or congenital deformities pose a difficult problem for reconstructive surgeons. Human adipose stem cells (ADSCs) can differentiate into bone and cartilage and together with suitable scaffolds could provide a promising system for skeletal tissue engineering. It has been suggested that nanomaterials can direct cell behavior depending on their surface nanotopographies. Thus, this study examined whether by altering a nanoscaffold surface using radiofrequency to excite gases, argon (Ar), nitrogen (N2) and oxygen (O2) with a single step technique, we could enhance the osteogenic and chondrogenic potential of ADSCs. At 24 h, Ar modification promoted the highest increase in ADSCs adhesion as indicated by upregulation of vinculin and focal adhesion kinase (FAK) expression compared to O2 and N2 scaffolds. Furthermore, ADSCs on Ar-modified nanocomposite polymer POSS-PCU scaffolds upregulated expression of bone markers, alkaline phosphatase, collagen I and osteocalcin after 3 weeks. Cartilage markers, aggrecan and collagen II, were also upregulated on Ar-modified scaffolds at the mRNA and protein level. Finally, all plasma treated scaffolds supported tissue ingrowth and angiogenesis after grafting onto the chick chorioallantoic membrane. Ar promoted greater expression of vascular endothelial growth factor and laminin in ovo compared to O2 and N2 scaffolds as shown by immunohistochemistry. This study provides an important understanding into which surface chemistries best support the osteogenic and chondrogenic differentiation of ADSCs that could be harnessed for regenerative skeletal applications. Argon surface modification is a simple tool that can promote ADSC skeletal differentiation that is easily amenable to translation into clinical practice.

Cancer Testis Antigen Promotes Triple Negative Breast Cancer Metastasis and is Traceable in the Circulating Extracellular Vesicles

Triple negative breast cancer (TNBC) has poor survival, exhibits rapid metastases, lacks targeted therapies and reliable prognostic markers. Here, we examined metastasis promoting role of cancer testis antigen SPANXB1 in TNBC and its utility as a therapeutic target and prognostic biomarker. Expression pattern of SPANXB1 was determined using matched primary cancer, lymph node metastatic tissues and circulating small extracellular vesicles (sEVs). cDNA microarray analysis of TNBC cells stably integrated with a metastasis suppressor SH3GL2 identified SPANXB1 as a potential target gene. TNBC cells overexpressing SH3GL2 exhibited decreased levels of both SPANXB1 mRNA and protein. Silencing of SPANXB1 reduced migration, invasion and reactive oxygen species production of TNBC cells. SPANXB1 depletion augmented SH3GL2 expression and decreased RAC-1, FAK, A-Actinin and Vinculin expression. Phenotypic and molecular changes were reversed upon SPANXB1 re-expression. SPANXB1 overexpressing breast cancer cells with an enhanced SPANXB1:SH3GL2 ratio achieved pulmonary metastasis within 5 weeks, whereas controls cells failed to do so. Altered expression of SPANXB1 was detected in the sEVs of SPANXB1 transduced cells. Exclusive expression of SPANXB1 was traceable in circulating sEVs, which was associated with TNBC progression. SPANXB1 represents a novel and ideal therapeutic target for blocking TNBC metastases due to its unique expression pattern and may function as an EV based prognostic marker to improve TNBC survival. Uniquely restricted expression of SPANXB1 in TNBCs, makes it an ideal candidate for targeted therapeutics and prognostication.

Senescence as a main mechanism of Ritonavir and Ritonavir-NO action against melanoma.

The main focus of this study is exploring the effect and mechanism of two HIV-protease inhibitors: Ritonavir and Ritonavir-nitric oxide (Ritonavir-NO) on in vitro growth of melanoma cell lines. NO modification significantly improved the antitumor potential of Ritonavir, as the IC50 values of Ritonavir-NO were approximately two times lower than IC50 values of the parental compound. Our results showed for the first time, that both compounds induced senescence in primary and metastatic melanoma cell lines. This transformation was manifested as a change in cell morphology, enlargement of nuclei, increased cellular granulation, upregulation of β-galactosidase activity, lipofuscin granules appearance, higher production of reactive oxygen species and persistent inhibition of proliferation. The expression of p53, as one of the key regulators of senescence, was upregulated after 48 hours of Ritonavir-NO treatment only in metastatic B16F10 cells, ranking it as a late-response event. The development of senescent phenotype was consistent with the alteration of the cytoskeleton-as we observed diminished expression of vinculin, α-actin, and β-tubulin. Permanent inhibition of S6 protein by Ritonavir-NO, but not Ritonavir, could be responsible for a stronger antiproliferative potential of the NO-modified compound. Taken together, induction of senescent phenotype may provide an excellent platform for developing therapeutic approaches based on selective killing of senescent cells.

Vinculin promotes gastric cancer proliferation and migration and predicts poor prognosis in patients with gastric cancer.

Vinculin is a highly conserved protein involved in cell proliferation, migration, and adhesion. However, the effects of vinculin on gastric cancer (GC) remain unclear. Therefore, we aimed to explore the functional role of vinculin in GC, as well as its underlying mechanism. Expression of vinculin in patients with GC was analyzed by real-time polymerase chain reaction, Western blot analysis, and immunohistochemistry. Overall survival was evaluated by the Kaplan-Meier method with the log-rank test. The relationship between vinculin and clinicopathological characteristics of patients with GC was further identified. In addition, we assessed the expression of vinculin in GC cell lines. Besides, vinculin was suppressed or overexpressed by transfection with small interfering (si-vinculin) or pcDNA-vinculin and then cell viability, cell apoptosis, and/or migration was respectively examined by the 3-(4, 5-dimethylthiazole-2-yl)-2, 5-biphenyl tetrazolium bromide assay, flow cytometer, and scratch assay, respectively. Moreover, the cell cycle- and apoptosis-related proteins were detected by Western blot analysis. The expression of vinculin was significantly increased in the GC tissues and cells compared with the nontumor tissues or cells. Vinculin protein positive staining was mainly located in the cell membrane and cytoplasm. Moreover, vinculin was significantly associated with Tumor Node Metastasis (TNM) and poor differentiation. Patients with high vinculin levels had significantly worse overall survival than those with low levels. Suppression of vinculin significantly decreased cell viability and migration and promoted cell apoptosis. However, overexpression of vinculin statistically increased cell viability but had no effects on cell apoptosis. Vinculin promotes GC proliferation and migration and predicts poor prognosis in patients with GC.

Vinculin expression in non-small cell lung cancer.

ObjectiveThis study aimed to explore the expression of vinculin in non-small cell lung cancer (NSCLC) and to analyze its correlation with clinical features and prognosis of NSCLC.MethodsThe expression of vinculin in cancer tissues and paracancer tissues was detected by real-time PCR, western blotting, and immunohistochemistry. Correlations between vinculin-positive expression and clinical features were analyzed by Pearson correlation analysis, and those between vinculin expression and prognosis were analyzed by Cox multivariate analysis.ResultsVinculin expression was significantly lower in cancer tissues than in paracancer tissues. Pearson correlation analysis showed that vinculin expression was significantly correlated with tumor–node–metastasis (TNM) stage and lymph node metastasis in NSCLC. Cox multivariate analysis showed that vinculin-negative expression and TNM stage were independent risk factors for NSCLC prognosis. Kaplan–Meier analysis showed that the 5-year overall survival (OS) rate was 20.51% for all NSCLC patients, and was significantly higher for vinculin-positive patients with NSCLC than vinculin-negative patients.ConclusionsVinculin gene transcription is inhibited in NSCLC, and low vinculin expression promotes malignancy in NSCLC. Therefore, vinculin could be used as a prognostic marker for NSCLC and a potential target for its treatment.

Surface Immobilization of TiO2 Nanotubes with Bone Morphogenetic Protein-2 Synergistically Enhances Initial Preosteoblast Adhesion and Osseointegration.

Although titanium (Ti) alloys have been widely used as implant materials, the bioinertness of pristine Ti impairs their bioactivity and early osseointegration. In the present work, we prepared TiO2 nanotubes (TNT) layer on the titanium (Ti) surface by anodic oxidation. The anodized surface was functionalized with human bone morphogenetic protein-2 coating to form the hBMP-2/TNT surface. The release behavior of hBMP-2 on the hBMP-2/TNT surface displayed a controlled and sustained pattern, compared to that on the hBMP-2/Ti surface, which showed a rapid release. In vitro cellular activity tests demonstrated that both TNT and hBMP-2/Ti surfaces, particularly the hBMP-2/TNT surface, enhanced adhesion, proliferation, and differentiation of osteoblast cells. Increased cell adhesion, improved cytoskeleton organization, and immunofluorescence staining of vinculin were observed on the modified surfaces. The TNT, hBMP-2/Ti, and hBMP-2/TNT surfaces, especially the hBMP-2/TNT surface, further displayed an upregulated gene expression of adhesion and osteogenic markers vinculin, collagen type 1, osteopontin, and osteocalcin, compared to the pristine Ti surface. In vivo experiments using a rat model demonstrated that the TNT and hBMP-2/Ti surfaces, in particular the hBMP-2/TNT surface, improved osseointegration and showed a superior bone bonding ability compared to Ti. Our study revealed a synergistic role played by TiO2 nanotubes nanotopography and hBMP-2 in promoting initial osteoblast adhesion, proliferation, differentiation, and osseointegration, thus suggesting a promising method for better modifying the implant surface.

Morphological and mechanical stability of bladder cancer cells in response to substrate rigidity

BackgroundMorphology of cells can be considered as an interplay between the accessibility of substrate anchoring sites, cytoskeleton properties and cellular deformability. To withstand tension induced by cell's environment, cells tend to spread out and, simultaneously, to remodel actin filament organization. MethodsIn this context, the use of polyacrylamide hydrogel substrates with a surface coated with laminin allows to trace remodeling of actin cytoskeleton during the interaction of cells with laminin-rich basement membrane. Reorganization of actin cortex can be quantified by a surface spreading area and deformability of single cells. ResultsIn our study, we demonstrated that morphological and mechanical alterations of bladder cancer cells in response to altered microenvironment stiffness are of biphasic nature. Threshold-dependent relations are induced by mechanical properties of cell microenvironment. Initially, fast alterations in cellular capability to spread and to deform are followed by slow-rate changes. A switch provided by cellular deformability threshold, in the case of non-malignant cells, triggers the formation of thick actin bundles accompanied by matured focal adhesions. For cancer cells, cell spreading and deformability thresholds switch between slow and fast rate of changes with weak reorganization of actin filaments and focal adhesions formation. ConclusionsThe presence of transition region enables the cells to achieve a morphological and mechanical stability, which together with altered expression of vinculin and integrins, can contribute to invasiveness of bladder cancers. General significanceOur findings show that morphological and mechanical stability is directly related to actin filament organization used by cancer cells to adapt to altered laminin-rich microenvironment.

Mechanical strain promotes osteogenic differentiation of mesenchymal stem cells on TiO2 nanotubes substrate

Previous studies demonstrated cycle mechanical strain induced osteogenic differentiation of MSCs. But in general, MSCs are typically seeded on a flexible membrane or within a soft matrix. TiO2 nanotubes substrate topography plays a critical role in promoting the MSCs response and affects MSCs fate. Titanium implants surface modified by TiO2 nanotubes topography provides the opportunity to improve osseointegration by additionally regulating the MSCs fate. Titanium is one of most commonly used materials in the orthopedics and can undergo elastic deformation under certain mechanical stress. Therefore, for clinic trails, it is necessary to investigate the effect of mechanical strain on osteogenesis of MSCs on TiO2 nanotubes modified titanium substrate. But until now, there has been no research focused on the relationship between mechanical strain and osteogenesis of MSCs on the TiO2 nanotubes topography substrate. Here, we firstly applied the mechanical stress to the TiO2 nanotubes modified titanium specimen to investigate the effects of mechanical strain on the biological behaviors of MSCs. Our present study showed that mechanical strain promoted cell proliferation, spreading and increased vinculin expression of MSCs on the TiO2 nanotubes substrate. Additionally, mechanical strain enhanced the ALP activity and osteogenesis genes expression such as Runx2, BSP, ALP, OPN and OCN. Our results preliminarily demonstrated that mechanical strain enhanced the osteogenic differentiation of MSCs through the FAK-Erk1/2-Runx2 pathway on the TiO2 nanotubes substrate.

MicroRNA 210 Mediates VEGF Upregulation in Human Periodontal Ligament Stem Cells Cultured on 3DHydroxyapatite Ceramic Scaffold.

The aim of the present research was the evaluation of the behavior of human periodontal ligament stem cells (hPDLSCs), cultured in presence of Endobon® Xenograft Granules (G), a fully deproteinated hydroxyapatite ceramic scaffold derived from cancellous bovine bone. hPDLSCs were seeded with and without G for 24 h to 1 week. The cell growth, morphological features, adhesiveness, differentiation ability, modulation of miR-210 and Vascular Endothelial Growth Factor (VEGF) secretion were analyzed by means of MTT assay, Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscopy (CLSM), Alizarin Red S assay, RT-PCR and ELISA test, respectively. hPDLSCs grown on the biomaterial showed the ability to form focal adhesion on the substrate, as demonstrated by vinculin expression. These data were supported by SEM analysis showing that an adhesiveness process associated to cell growth occurs between cells and biomaterials. The osteogenic differentiation, evaluated by morphological, biochemical, and RT-PCR analysis, was pronounced in the hPDLSCs grown in the three-dimensional inorganic bovine bone substitute in the presence of osteoinductive conditions. In addition, an upregulation of miR-210 and VEGF was evident in cells cultured in presence of the biomaterial. Our results inspire us to consider granules not only an adequate biocompatible three-dimensional biomaterial, but also an effective inductor of miR-210 and VEGF; in fact, the involvement of miR-210 in VEGF secretion could offer a novel regulatory system in the early steps of the bone-regeneration process.

Vinculin and the mechanical response of adherent fibroblasts to matrix deformation

Cells respond to the mechanics of their environment. Mechanical cues include extracellular matrix (ECM) stiffness and deformation, which are primarily sensed through integrin-mediated adhesions. We investigated the impact of ECM deformation on cellular forces, measuring the time-evolution of traction forces of isolated mouse fibroblasts in response to stretch and release. Stretch triggered a marked increase of traction stresses and apparent stiffness. Expression of the focal adhesion protein vinculin not only increased baseline traction forces, but also increased dissipation of mechanical energy, which was correlated with the cells’ failure to recover baseline traction forces after release of stretch.