Integrins are a large family of heterodimeric cell adhesion molecules composed of α and β subunits. Through interaction with their specific ligands, integrins mediate cell-cell and cell-extracellular matrix interactions. Via outside-in signaling, integrins can recruit cytoplasmic proteins to their intracellular domains and then cluster into supramolecular structures and trigger downstream signaling. Integrin activation is associated with a global conformation rearrangement from bent to extended in ectodomains and the separation of α and β subunit cytoplasmic domains. During cell migration, integrins regulate the focal adhesion dynamics and transmit forces between the extracellular matrix and the cell cytoskeleton. In tumor microenvironment, integrins on multiple kinds of cells could be activated, which modulates cell migration into tumor and contributes to angiogenesis and tumor metastasis. Here, we review the mechanism of integrin activation, dynamics of focal adhesions during cell migration and tumor metastasis.
Cell Adhesion ; Cell Adhesion Molecules ; Focal Adhesions ; Integrins ; Signal Transduction

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.
Actins ; Apoptosis Inducing Factor ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspases ; Cell Adhesion ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Death ; Cyclin A ; Cyclin D1 ; Cyclin E ; Cyclins ; Cytochromes c ; Cytoplasm ; DNA Fragmentation ; Down-Regulation ; Flow Cytometry ; Fluorescent Antibody Technique ; Focal Adhesions ; Melanoma ; Mitochondria ; Nanoparticles ; Phosphotransferases ; Receptor, Epidermal Growth Factor ; Up-Regulation

PURPOSE: Despite the well-known anti-inflammatory effects of vitamin D in periodontal health, its mechanism has not been fully elucidated. In the present study, the effect of vitamin D on strengthening E-cadherin junctions (ECJs) was explored in human gingival keratinocytes (HGKs). ECJs are the major type of intercellular junction within the junctional epithelium, where loose intercellular junctions develop and microbial invasion primarily occurs. METHODS: HOK-16B cells, an immortalized normal human gingival cell line, were used for the study. To mimic the inflammatory environment, cells were treated with tumor necrosis factor-alpha (TNF-α). Matrix metalloproteinases (MMPs) in the culture medium were assessed by an MMP antibody microarray and gelatin zymography. The expression of various molecules was investigated using western blotting. The extent of ECJ development was evaluated by comparing the average relative extent of the ECJs around the periphery of each cell after immunocytochemical E-cadherin staining. Vitamin D receptor (VDR) expression was examined via immunohistochemical analysis. RESULTS: TNF-α downregulated the development of the ECJs of the HGKs. Dissociation of the ECJs by TNF-α was accompanied by the upregulation of MMP-9 production and suppressed by a specific MMP-9 inhibitor, Bay 11-7082. Exogenous MMP-9 decreased the development of ECJs. Vitamin D reduced the production of MMP-9 and attenuated the breakdown of ECJs in the HGKs treated with TNF-α. In addition, vitamin D downregulated TNF-α-induced nuclear factor kappa B (NF-κB) signaling in the HGKs. VDR was expressed in the gingival epithelium, including the junctional epithelium. CONCLUSIONS: These results suggest that vitamin D may avert TNF-α-induced downregulation of the development of ECJs in HGKs by decreasing the production of MMP-9, which was upregulated by TNF-α. Vitamin D may reinforce ECJs by downregulating NF-κB signaling, which is upregulated by TNF-α. Strengthening the epithelial barrier may be a way for vitamin D to protect the periodontium from bacterial invasion.
Bays ; Blotting, Western ; Cadherins ; Cell Line ; Down-Regulation ; Epithelial Attachment ; Epithelium ; Gelatin ; Humans ; Intercellular Junctions ; Keratinocytes ; Matrix Metalloproteinase 9 ; Matrix Metalloproteinases ; NF-kappa B ; Periodontium ; Receptors, Calcitriol ; Tumor Necrosis Factor-alpha ; Up-Regulation ; Vitamin D ; Vitamins

The biophysical properties of the extracellular matrix (ECM) dictate tissue-specific cell behaviour. In the skeleton system, bone shows the potential to adapt its architecture and contexture to environmental rigidity via the bone remodelling process, which involves chondrocytes, osteoblasts, osteoclasts, osteocytes and even peripheral bone marrow-derived stem/stromal cells (BMSCs). In the current study, we generated stiff (~1 014 ± 56) kPa, Young's modulus) and soft (~46 ± 11) kPa silicon-based elastomer polydimethylsiloxane (PDMS) substrates by mixing curing agent into oligomeric base at 1:5 and 1:45 ratios, respectively, and investigated the influence of substrate stiffness on the cell behaviours by characterizing cell spreading area, cell cytoskeleton and cell adhesion capacity. The results showed that the cell spreading areas of chondrocytes, osteoblasts, osteoclasts, osteocytes and BMSCs were all reduced in the soft substrate relative to those in the stiff substrate. F-actin staining confirmed that the cytoskeleton was also changed in the soft group compared to that in the stiff group. Vinculin in focal adhesion plaques was significantly decreased in response to soft substrate compared to stiff substrate. This study establishes the potential correlation between microenvironmental mechanics and the skeletal system, and the results regarding changes in cell spreading area, cytoskeleton and cell adhesion further indicate the important role of biomechanics in the cell-matrix interaction.
Actins ; Cell Adhesion ; Elastic Modulus ; Focal Adhesions ; physiology ; Humans ; Vinculin ; analysis ; metabolism

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.
Actins ; Animals ; Cell Movement* ; Extracellular Matrix ; Focal Adhesions ; Gene Expression ; Homeostasis ; Infrared Rays ; Integrins ; Microarray Analysis ; Muscle, Skeletal* ; Platelet-Derived Growth Factor* ; Rats ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Wound Healing

BACKGROUND: Actinic keratosis (AK) was an intraepidermal tumor which caused by ultraviolet irradiation-induced skin damage. OBJECTIVE: The aim was to screen biomarkers for development of skin disease by comparing the gene expression profiles between cutaneous squamous cell carcinoma (CSCC) and AK. METHODS: GSE45216 with 30 cutaneous squamous cell carcinoma patients and 10 actinic keratosis patients were downloaded and significance analysis of microarrays was processed to screen differently expressed genes (DEGs). Fisher's exact test was processed for DEGs enrichment. Pathway relationship network systematically reflected the signal conduction and synergism between enriched pathways based on Kyoto Encyclopedia of Genes and Genomes database. Gene co-expression network was constructed according to gene expression data. Quantitative real-time-PCR was used to verify screened biomarkers. RESULTS: Total 410 DEGs were screened and enriched into various functions, such as signal transduction and negative regulation of apoptotic process. They also participated into cytokine-cytokine receptor interaction and focal adhesion. The pathway relationship network was constructed with 27 nodes. Hub nodes with higher degree of this network were mitogen-activated protein kinase signaling pathway and apoptosis. The gene co-expression network was constructed with 39 nodes. Thereinto, hub node was ELOVL fatty acid elongase. The expression levels of ELOVL4 and HPGD were significantly higher in CSCC samples than that in AK samples, while the expression levels of INHBA and LAMC2 in CSCC samples were significantly lower than that in AK samples. CONCLUSION: These screened genes, including ELOVL4, HPGD, INHBA and LAMC2, played important roles in transformation from AK to CSCC.
Actins* ; Apoptosis ; Biomarkers* ; Carcinoma, Squamous Cell* ; Diagnosis* ; Epithelial Cells* ; Focal Adhesions ; Gene Expression* ; Genome ; Humans ; Keratosis, Actinic* ; Mass Screening* ; Protein Kinases ; Signal Transduction ; Skin Diseases* ; Skin* ; Transcriptome

Baicalein, a natural flavonoid obtained from the rhizome of Scutellaria baicalensis Georgi, has been reported to have anticancer activities in several human cancer cell lines. However, its antimetastatic effects and associated mechanisms in melanoma cells have not been extensively studied. The current study examined the effects of baicalein on cell motility and anti-invasive activity using mouse melanoma B16F10 cells. Within the noncytotoxic concentration range, baicalein significantly inhibited the cell motility and invasiveness of B16F10 cells in a concentration-dependent manner. Baicalein also reduced the activity and expression of matrix metalloproteinase (MMP)-2 and -9; however, the levels of tissue inhibitor of metalloproteinase-1 and -2 were concomitantly increased. The inhibitory effects of baicalein on cell motility and invasiveness were found to be associated with its tightening of tight junction (TJ), which was demonstrated by an increase in transepithelial electrical resistance and downregulation of the claudin family of proteins. Additionally, treatment with baicalein markedly reduced the expression levels of lipopolysaccharide-induced phosphorylated Akt and the invasive activity in B16F10 cells. Taken together, these results suggest that baicalein inhibits B16F10 melanoma cell migration and invasion by reducing the expression of MMPs and tightening TJ through the suppression of claudin expression, possibly in association with a suppression of the phosphoinositide 3-kinase/Akt signaling pathway.
Animals ; Cell Line ; Cell Movement ; Down-Regulation ; Electric Impedance ; Humans ; Matrix Metalloproteinases ; Melanoma* ; Mice* ; Rhizome ; Scutellaria baicalensis ; Tight Junctions ; Tissue Inhibitor of Metalloproteinase-1

PURPOSE: To evaluate the postoperative outcome of the multiple slit on plaque plication technique for the treatment of Peyronie's disease. MATERIALS AND METHODS: We retrospectively evaluated 22 patients who underwent plaque incision with penile plication for the surgical treatment of Peyronie's disease, who had failed medical treatment between 2009 and 2014. Patients were grouped by preoperative degree of penile curvature into Group I: mild (n=5, 22.7%), Group II: moderate (n=11, 50.0%), and Group III: severe (n=6, 27.3%). After a thorough review of the medical records, we evaluated (a) the correction of the curvature; (b) sexual function; and (c) any penile shortening or other complications. RESULTS: The mean postoperative follow-up period was 39 months. Complete correction of the curvature was attained in 21 patients (95.5%). As an inevitable complication, minimal penile shortening (<1.5 cm) was reported by 14 patients (82.4%) but did not adversely affect sexual intercourse (0%), and all patients found the extent of penile shortening to be acceptable. Nineteen patients had good erectile function (International Index of Erectile Function >21). The most frequent complication was subcutaneous penile edema in three patients (13.6%), which was resolved within about 3 months following surgery. CONCLUSIONS: As a modified technique, multiple slit on plaque with plication is a simple, minimally-invasive and effective technique for correcting penile curvature regardless of curvature severity. The degree of penile curvature does not significantly predict the amount of penile length loss.
Coitus ; Edema ; Focal Adhesions ; Follow-Up Studies ; Humans ; Male ; Medical Records ; Penile Induration* ; Retrospective Studies

PURPOSE: To analyze the structural and morphological characteristics of retinal astrocytic hamartomas in tuberous sclerosis patients using fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography. CASE SUMMARY: Fundus examination, fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography were performed in three patients with tuberous sclerosis and the morphological and structural characteristics of retinal astrocytic hamartomas were analyzed. In the fundus autofluorescence, type 1 retinal astrocytic hamartoma showed hypofluorescence and type 3 showed central hyperfluorescence and surrounding hypofluorescence. Spectral domain optical coherence tomography showed dome-shaped hyper-reflectivity within the nerve fiber layer and focal adhesion of the vitreous cortex in the type 1 retinal astrocytic hamartoma. No abnormalities were observed in the outer retinal layer and retinal pigment epithelium. In the type 3 retinal astrocytic hamartoma, optical coherence tomography showed disorganization of retinal tissue and posterior shadowing. Intratumoral cavitation and moth-eaten appearance caused by intratumoral calcification were observed and the vitreous cortex adhered to the top of the tumor and showed traction. Retinal arterial sheathing was observed in all cases and hyper- reflectivity of the arterial wall was noted on optical coherence tomography. CONCLUSIONS: Fundus autofluorescence, fluorescein angiography and spectral-domain optical coherence tomography are helpful for the classification and diagnosis of retinal astrocytic hamartomas found in tuberous sclerosis patients as well as for differentiation from other lesions.
Classification ; Diagnosis ; Fluorescein Angiography* ; Fluorescein* ; Focal Adhesions ; Hamartoma* ; Humans ; Nerve Fibers ; Retinal Pigment Epithelium ; Retinaldehyde* ; Shadowing (Histology) ; Tomography, Optical Coherence* ; Traction ; Tuberous Sclerosis*

Epidermolysis bullosa (EB) comprises a collection of clinically diverse inherited blistering diseases that affect the skin and, in some subtypes, mucous membranes and other organs. Currently classified into four main subtypes (EB simplex, junctional EB, dystrophic EB, and Kindler syndrome, mainly based on the level of skin cleavage), the spectrum of EB extends to more than 30 clinical subtypes with pathogenic mutations in at least 18 distinct genes. This review focuses on three recent additions to variants of EB: all are autosomal recessive, and result from mutations in either DST-e (coding for epidermal dystonin, also known as the 230 kDa bullous pemphigoid antigen, BP230), EXPH5 (coding for exophilin-5, also known as Slac2-b), or ITGA3 (coding for the integrin alpha-3 subunit). Each of these new forms of EB is reviewed with respect to the initial gene discovery, clinical features, the current mutation database, and skin pathology. Awareness of these recently described forms of EB is helpful in the clinical evaluation of patients with EB and in defining genotype-phenotype correlation for inherited blistering skin diseases.
Basement Membrane ; Blister ; Epidermolysis Bullosa* ; Genetic Association Studies ; Hemidesmosomes ; Humans ; Mucous Membrane ; Pathology ; Pemphigoid, Bullous ; Skin ; Skin Diseases ; Transport Vesicles