Differentiation Matrix Research Articles

Apigenin attenuates TGF-β1-stimulated cardiac fibroblast differentiation and extracellular matrix production by targeting miR-155-5p/c-Ski/Smad pathway

Ethnopharmacological relevanceApigenin is a natural flavonoid compound present in chamomile (Matricaia chamomilla L.) from the Asteraceae family, which is used in the treatment of cardiovascular diseases by traditional healers, but its effects on differentiation and extracellular matrix (ECM) production of cardiac fibroblasts (CFs) induced by transforming growth factor beta 1 (TGF-β1) are poorly understood. Aim of the studyThis study aimed to examine these effects and potential molecular mechanisms and to provide a new application of apigenin in the prevention and treatment of cardiac fibrosis. Materials and methodsThe TGF-β1-stimulated CFs or the combination of TGF-β1-stimulated and microRNA-155-5p (miR-155-5p) inhibitor- or mimic-transfected CFs were treated with or without apigenin. The expression levels of intracellular related mRNA and proteins were detected by real-time polymerase chain reaction and Western blot methods, respectively. The luciferase reporter gene containing cellular Sloan-Kettering Institute (c-Ski) wild or mutant type 3′-UTR was used and the luciferase activity was examined to verify the direct link of miR-155-5p and c-Ski. ResultsAfter treatment of TGF-β1-stimulated CFs with 6–24 μM apigenin, the expression of c-Ski was increased, while levels of miR-155-5p, α-smooth muscle actin, collagen Ⅰ/Ⅲ, Smad2/3, and p-Smad2/3 were decreased. After transfection of CFs with the miR-155-5p inhibitor or mimic, the similar or inverse results were respectively observed as well. The combination of TGF-β1 and miR-155-5p inhibitor or mimic might cause an antagonistical or synergistic effect, respectively, and apigenin addition could enhance the effects of the inhibitor and antagonize the effects of the mimic. Luciferase reporter gene assay demonstrated that c-Ski was a direct target of miR-155-5p. ConclusionThese findings suggested that apigenin could inhibit the differentiation and ECM production in TGF-β1-stimulated CFs, and its mechanisms might partly be attributable to the reduction of miR-155-5p expression and subsequent increment of c-Ski expression, which might result in the inhibition of Smad2/3 and p-Smad2/3 expressions.

Supramolecular Injectable Hyaluronate Hydrogels for Cartilage Tissue Regeneration

Mesenchymal stem cells (MSCs) have been widely investigated to repair injured cartilage tissues for the treatment of arthritis. Despite these great efforts, the difficulty in the spatiotemporal control of delivered cells has limited the further clinical development with rapid clearance. Here, we developed injectable hyaluronate (HA) hydrogels to encapsulate MSCs for controlled cartilage tissue regeneration based on the supramolecular chemistry between β-cyclodextrin-modified HA (HA-CD) and adamantane (Ad)-modified HA (HA-Ad). Supramolecular HA hydrogels exhibited remarkable mechanical characteristics such as shear thinning and self-healing with a high cell viability of encapsulated MSCs. The spatiotemporally controlled delivery of MSCs from the supramolecular HA hydrogels resulted in the statistically significant chondrogenic differentiation and extracellular matrix deposition in vitro and in vivo. We could confirm the notable cartilage tissue regeneration in cartilage defect model rats after treatment with supramolecular HA hydrogels encapsulating MSCs for 28 days. Taken together, supramolecular HA hydrogels would be successfully harnessed as an injectable delivery system of MSCs for cartilage tissue regeneration and other tissue engineering applications.

The Secretome Analysis of Activated Human Renal Fibroblasts Revealed Beneficial Effect of the Modulation of the Secreted Peptidyl-Prolyl Cis-Trans Isomerase A in Kidney Fibrosis.

The secretome is an important mediator in the permanent process of reciprocity between cells and their environment. Components of secretome are involved in a large number of physiological mechanisms including differentiation, migration, and extracellular matrix modulation. Alteration in secretome composition may therefore trigger cell transformation, inflammation, and diseases. In the kidney, aberrant protein secretion plays a central role in cell activation and transition and in promoting renal fibrosis onset and progression. Using comparative proteomic analyses, we investigated in the present study the impact of cell transition on renal fibroblast cells secretome. Human renal cell lines were stimulated with profibrotic hormones and cytokines, and alterations in secretome were investigated using proteomic approaches. We identified protein signatures specific for the fibrotic phenotype and investigated the impact of modeling secretome proteins on extra cellular matrix accumulation. The secretion of peptidyl-prolyl cis-trans isomerase A (PPIA) was demonstrated to be associated with fibrosis phenotype. We showed that the in-vitro inhibition of PPIA with ciclosporin A (CsA) resulted in downregulation of PPIA and fibronectin (FN1) expression and significantly reduced their secretion. Knockdown studies of PPIA in a three-dimensional (3D) cell culture model significantly impaired the secretion and accumulation of the extracellular matrix (ECM), suggesting a positive therapeutic effect on renal fibrosis progression.

What Have In Vitro Co-Culture Models Taught Us about the Contribution of Epithelial-Mesenchymal Interactions to Airway Inflammation and Remodeling in Asthma?

As the lung develops, epithelial-mesenchymal crosstalk is essential for the developmental processes that drive cell proliferation, differentiation, and extracellular matrix (ECM) production within the lung epithelial-mesenchymal trophic unit (EMTU). In asthma, a number of the lung EMTU developmental signals have been associated with airway inflammation and remodeling, which has led to the hypothesis that aberrant activation of the asthmatic EMTU may lead to disease pathogenesis. Monoculture studies have aided in the understanding of the altered phenotype of airway epithelial and mesenchymal cells and their contribution to the pathogenesis of asthma. However, 3-dimensional (3D) co-culture models are needed to enable the study of epithelial-mesenchymal crosstalk in the setting of the in vivo environment. In this review, we summarize studies using 3D co-culture models to assess how defective epithelial-mesenchymal communication contributes to chronic airway inflammation and remodeling within the asthmatic EMTU.

An oriented-collagen scaffold including Wnt5a promotes osteochondral regeneration and cartilage interface integration in a rabbit model.

Articular cartilage regeneration remains a major challenge in orthopedics. Noncanonical Wnt5a is a particularly attractive growth factor in this context; Wnt5a inhibits chondrocyte hypertrophy but maintains chondrogenesis. We designed a novel, vertically oriented-collagen scaffold. The effect of Wnt5a on MSCs and chondrocytes and the therapeutic effects of the Wnt5a/oriented-collagen scaffold in terms of osteochondral repair and cartilage integration were evaluated. In vitro, the proliferation, migration, and differentiation of MSCs and chondrocytes treated with Wnt5a, and the mechanisms thereof, were assessed. mRNA microarray analysis was performed to compare the expression profiles of MSCs before and after Wnt5a treatment. In vivo, full-thickness cylindrical osteochondral defects (4mm in diameter, 3mm in depth) were created in the patellar grooves of 24 New Zealand white rabbits and implanted with oriented-collagen scaffolds (n=8), Wnt5a/oriented-collagen scaffolds (n=8), or nothing (n=8). After 6 and 12weeks, integration and tissue responses were evaluated. The proliferation, migration, chondrogenic differentiation, and extracellular matrix formation of/by MSCs and chondrocytes improved greatly after treatment with Wnt5a. Western blotting showed that the PI3K/AKT/JNK signaling pathway was activated. Microarray analysis revealed that the Wnt5a group exhibited a significant upregulation of the PI3K pathway. Reactome GSEA pathway interaction analysis revealed that such upregulation was associated with collagen and extracellular matrix formation. In vivo, the Wnt5a/oriented-collagen scaffold group exhibited optimal interface integration, cartilage regeneration, and collagenous fiber arrangement, accompanied by significantly increased glycosaminoglycan and collagen accumulations in the zones of regeneration and integration, compared to the other groups. Gene expression analysis showed that the levels of mRNAs encoding genes involved in cartilage formation were significantly increased in the Wnt5a/oriented, collagen scaffold group (all P<.05). Wnt5a promoted the proliferation, migration, and chondrogenic differentiation of MSCs and chondrocytes via the activation of the PI3K/AKT/JNK signaling pathway. The Wnt5a/oriented-collagen constructs enhanced the structure-specific regeneration of hyaline cartilage in a rabbit model and may be a promising treatment for the repair of human cartilage defects.

A fourth-order dissipation-preserving algorithm with fast implementation for space fractional nonlinear damped wave equations

In this paper, we numerically investigate the space fractional nonlinear damped wave equation. We construct a novel high-accuracy dissipation-preserving finite difference scheme by using the new fourth-order fractional central difference operator. Thanks to the toeplitz-like differentiation matrix, we further raise the computation efficiency of the proposed scheme by fast Fourier transform. Moreover, we obtain the error estimate of our proposed scheme in L2 and Hα/2 (1 < α ≤ 2) norm, respectively. Finally, we verify the discrete dissipation-preserving law and convergence of the proposed scheme by one- and two-dimensional numerical experiments in long-time observation.

Bioinspired mineral hydrogels as nanocomposite scaffolds for the promotion of osteogenic marker expression and the induction of bone regeneration in osteoporosis

Osteoporosis is one of the most prevalent age-related diseases worldwide and is characterized by a systemic deterioration of bone strength (bone mineral density and bone quality) with a resulting increase in fragility fractures. Due to the complex osteoporotic pathological environment, it is a huge challenge to induce bone regeneration under osteoporosis conditions. In this study, we successfully nanoengineer a bioinspired mineralized hydrogel from the supramolecular assembly of nano-hydroxyapatite, sodium carbonate, and polyacrylic acid, termed as CHAp-PAA. The resultant nanocomposite hydrogels can maintain their initial morphology and mechanical properties under physiological conditions, while exhibiting good primary stability, biocompatibility, bioactivity, and osteoconductivity. We demonstrate that this optimized hydrogel scaffold has shown superior performance for bone marrow stem cells (BMSCs) proliferation, differentiation, and extracellular matrix production in vitro. Remarkably, the mineralized CHAp-PAA hydrogels could be used as scaffolds for the critical-sized bone defect (6.0 mm diameter and 10.0 mm depth) in the osteoporotic rabbit model. Without the delivery of additional therapeutic agents or stem cells, these CHAp-PAA hydrogel scaffolds can improve bone ingrowth and accelerate new bone formation even in complex osteoporotic pathological environments. Therefore, this work presents a type of bioinspired multifunctional mineral hydrogel that offers an alternative strategy to manage osteoporosis. Statement of Significance•We successfully nanoengineer a bioinspired mineralized hydrogel from supramolecular assembly of nano-hydroxyapatite, sodium carbonate, and polyacrylic acid, termed as CHAp-PAA. The resultant nanocomposite hydrogels can maintain their initial morphology and mechanical properties under physiological conditions, while exhibiting good primary stability, biocompatibility, bioactivity, and osteoconductivity.•We demonstrate that this optimized hydrogel scaffold has shown superior performance for bone marrow stem cells (BMSCs) proliferation, differentiation, and extracellular matrix production in vitro.•Remarkably, the mineralized CHAp-PAA hydrogels could be used as scaffold for the critical-sized bone defect (6.0 mm diameter and 10.0 mm depth) in osteoporotic rabbit model. Without delivery of additional therapeutic agents or stem cells, these CHAp-PAA hydrogel scaffolds can improve bone ingrowth and accelerate new bone formation even in complex osteoporotic pathological environment.

A Chebyshev pseudo-spectral approach for simulating magnetotelluric TM-mode responses on 2D structures

We introduce a Chebyshev pseudo-spectral (CPS) approach for 2D TM-mode magnetotelluric modelling, which was the first applied on the magnetotellric data in 2D model. In this method, 2D partial differential equations are solved using the Chebyshev differentiation matrix over the Gauss-Chebysev-Lobatto points. In order to test computational efficiency and its accuracy, we compare the simulatation of this method to the analytical solution and finite element (FE) and finite difference (FD) methods. The comparison of CPS numerical solution and corresponding analytical solution on a homogeneous half-space model and a layered model show that the CPS approach can provide an accurate modelling result. The discrete nodes for modelling were also analyzed on two models, which suggest that a few nodes can produce modelling results with a high accuracy. Especially for 2D and 3D modelling problems, the reduction in the number of nodes can improve the computational efficiency significantly. However, the CPS approach will lead to an unsymmetrical and non-sparse matrix, which is not favored by the iterative solver. We further compare the numerical result of the CPS method to the FD method and the averaged numerical solutions of the COMMEMI on the COMMEMI 2D-1 model. We find the numerical result of CPS method is closer to the averaged numerical solutions of the COMMEMI than that of observed by the FD. Finally, a realistic smooth model is considered to compare the modelling results using the CPS method to the published data. All these comparison results suggest that the CPS method can not only give a high accuracy for modelling results and also provide more detail information. Especially, a few nodes can be required in this method relative to the FD and FE method, which can decrease the relative errors. We then deduce that CPS method might be an alternative approach to simulate the magnetotelluric responses in 2D structures.

Biomimetic bone regeneration using angle-ply collagen membrane-supported cell sheets subjected to mechanical conditioning

Bone injuries are common and new strategies are desired for achieving ideal bone regeneration for bone defect repair. Scaffolds with bone-mimicking characteristics may provide an appropriate microenvironment to promote bone regeneration. Meanwhile, mechanical stimulation effectively regulates a wide range of cellular behaviors such as cell proliferation and differentiation. In this study, biomimetic multi-layer cell-collagen constructs with angle-ply structural feature were prepared by assembling micropatterned collagen membranes on which aligned MC3T3-E1 cells were cultured. The anisotropic microgrooved collagen membranes effectively guided the alignment of cells and promoted the osteogenic differentiation of them. To further promote cell differentiation and extracellular matrix production, the multi-layer cell-collagen constructs were cultured under mechanical conditioning through cyclic stretching. It was found that the constructs with both cell alignment and mechanical conditioning resulted in better osteogenic potential than those with cell alignment or mechanical conditioning alone. Upon implantation into the critical-sized calvarial defects of mice, the constructs with both cell alignment and mechanical conditioning achieved best new bone formation efficacy. Together, findings from this study reveal that synergized use of microstructural and mechanical cues may provide an effective new approach toward bone regeneration. Statement of SignificanceBiomimicking is an effective strategy to promote bone regeneration for repairing bone defects. Although numerous studies which micro-structurally mimicked native bone using various scaffolds, far less studies have paid attention to the mechanical environment of bone. In this study, angle-ply collagen membrane-supported cell sheets were prepared and pre-conditioned using mechanical loading prior to implantation at bone defects. The constructs with cell alignment and subjected to mechanical conditioning resulted in better osteogenic differentiation of cells in vitro and new bone formation in vivo than those with cell alignment or mechanical conditioning alone. Therefore, recapitulation of both microstructural and mechanical features of native bone may result in a synergistic effect and provides an effective approach toward bone regeneration.

A Chebyshev pseudo spectral method for solving fractional differential equations

The Chebyshev pseudo-spectral method is generalized for solving fractional differential equations with initial conditions. For this purpose, an appropriate representation of the solution is presented and the Chebyshev pseudo-spectral differentiation matrix of fractional order is derived. Then, by using Chebyshev pseudo-spectral scheme, the problem is reduced to the solution of a system of algebraic equations.

Identification of Molecular Mechanisms Related to Pig Fatness at the Transcriptome and miRNAome Levels.

Fat deposition and growth rate are closely related to pork quality and fattening efficiency. The next-generation sequencing (NGS) approach for transcriptome and miRNAome massive parallel sequencing of adipocyte tissue was applied to search for a molecular network related to fat deposition in pigs. Pigs were represented by three breeds (Large White, Pietrain, and Hampshire) that varied in fat content within each breed. The obtained results allowed for the detection of significant enrichment of Gene Ontology (GO) terms and pathways associated directly and indirectly with fat deposition via regulation of fatty acid metabolism, fat cell differentiation, inflammatory response, and extracellular matrix (ECM) organization and disassembly. Moreover, the results showed that adipocyte tissue content strongly affected the expression of leptin and other genes related to a response to excessive feed intake. The findings indicated that modification of genes and miRNAs involved in ECM rearrangements can be essential during fat tissue growth and development in pigs. The identified molecular network within genes and miRNAs that were deregulated depending on the subcutaneous fat level are proposed as candidate factors determining adipogenesis, fatness, and selected fattening characteristics in pigs.

Functional Expression of Sodium-Dependent Glucose Transporter in Amelogenesis

Glucose is an essential source of energy for mammalian cells and is transported into the cells by glucose transporters. There are 2 types of glucose transporters: one is a passive glucose transporter, GLUT (SLC2A), and the other is a sodium-dependent active glucose transporter, SGLT (SLC5A). We previously reported that the expression of GLUTs during tooth development is precisely and spatiotemporally controlled and that the glucose uptake mediated by GLUT1 plays a crucial role in early tooth morphogenesis and tooth size determination. This study aimed to clarify the localization and roles of SGLT1 and SGLT2 in murine ameloblast differentiation by using immunohistochemistry, immunoelectron microscopy, an in vitro tooth organ culture experiment, and in vivo administration of an inhibitor of SGLT1/2, phloridzin. SGLT1, which has high affinity with glucose, was immunolocalized in the early secretory ameloblasts and the ruffle-ended ameloblasts in the maturation stage. However, SGLT2, which has high glucose transport capacity, was observed in the stratum intermedium, papillary layer, and ameloblasts at the maturation stage and colocalized with Na+-K+-ATPase. The inhibition of SGLT1/2 by phloridzin in the tooth germs induced the disturbance of ameloblast differentiation and enamel matrix formation both in vitro (organ culture) and in vivo (mouse model). The expression of SGLT1 and SGLT2 was significantly upregulated in hypoxic conditions in the ameloblast-lineage cells. These findings suggest that the active glucose uptake mediated by SGLT1 and SGLT2 is strictly regulated and dependent on the intra- and extracellular microenvironments during tooth morphogenesis and that the appropriate passive and active glucose transport is an essential event in amelogenesis.

Role of N-Cadherin in a Niche-Mimicking Microenvironment for Chondrogenesis of Mesenchymal Stem Cells In Vitro.

During the development of natural cartilage, mesenchymal condensation is the starting event of chondrogenesis, and mesenchymal stem cells (MSCs) experienced a microenvironment transition from primarily cell-cell interactions to a later stage, where cell-extracellular matrix (ECM) interactions dominate. Although micromass pellet culture has been developed to mimic mesenchymal condensation in vitro, the molecular mechanism remains elusive, and the transition from cell-cell to cell-ECM interactions has been poorly recapitulated. In this study, we first constructed MSC microspheres (MMs) and investigated their chondrogenic differentiation with functional blocking of N-cadherin. The results showed that early cartilage differentiation and cartilage-specific matrix deposition of MSCs in the group with the N-cadherin antibody were significantly postponed. Next, poly(l-lysine) treatment was transiently applied to promote the expression of N-cadherin gene, CDH2, and the treatment-promoted MSC chondrogenesis. Upon one-day culture in MMs with established cell-cell adhesions, collagen hydrogel-encapsulated MMs (CMMs) were constructed to simulate the cell-ECM interactions, and the collagen microenvironment compensated the inhibitory effects from N-cadherin blocking. Surprisingly, chondrogenic-differentiated cell migration, which has important implications in cartilage repair and integration, was found in the CMMs without N-cadherin blocking. In conclusion, our study demonstrated that N-cadherin plays the critical role in early mesenchymal condensation, and the collagen hydrogel provides a supportive microenvironment for late chondrogenic differentiation. Therefore, sequential presentations of cell-cell adhesion and cell-ECM interaction in an engineered microenvironment seem to be a promising strategy to facilitate MSC chondrogenic differentiation.

Effects of WNT5A signaling-mediated inflammation of macrophages upon cartilage homeostasis

Purpose: To construct and comparehumanbone marrow-derived mesenchymal stem cells (MSCs) two dimension (2D)and bone marrow aspirates in vitrtranswell separated co-cultural models with recombinant adeno-associated virus (rAAV)-Wnt5a-modified activated macrophages and investigate the effect of Wnt5a signaling upon cartilage homeostasis through the regulation of macrophage pro-inflammatory responses. Methods: Macrophages, MSCs,and bone marrow aspirates specimens were extracted from 6 patients with severe knee deformities undergoing total knee arthroplasty (2 males, 4 females, 58-71 years old). The synovial tissues of knee joints were exposed to type II collagenase and obtained single cell suspensions, and the purity of macrophages was determined by Ficoll gradient centrifugation and anti-CD14 antibody flow cytometry. The macrophages were transduced with rAAV-lacZ or Wnt5a respectively for 48 hours prior to the stimulation of IFN-γ combined TNF-α for 24 hours, and subsequently transferred to the upper compartment of the 96-well transwell plate, with hMSCs 2D monolayer, and bone marrow aspirates at the lower compartment, respectively (Figure 1 & 2). Cell morphology and proliferation (cellularity), viral transfection efficiency and secretion of proinflammatory cytokine were estimated by Haemotoxylin and Eosin (H&E) staining, toluidine blue staining, X-gal staining, anti-Wnt5a, anti-II and X collagen immunohistochemical staining and enzyme-linked immunosorbent assay (ELISA) assay, respectively. Results: The isolated synovial macrophages were positive against anti-CD14 primary antibody, with a percentage of 90.31%, indicating that the cells were macrophages. The level of monocyte chemotactic protein-1 in supernatants was significantly increased after stimulation with IFN-γ and TNF-α, indicating that the macrophages were activated and at proinflammatory condition (Figure 3). After transduction with rAAV-lacZ for 3 days, X-gal staining indicated that lacZ gene transfer could efficiently transducethe activated macrophages, with the efficiency over 97.50% for at least 21 days. rAAV-Wnt5a-modified macrophages enhanced the intrinsic expression of Wnt5a, stimulated the extrinsic expression of Wnt5a in the above two models and inhibited the secretion of MCP-1. The expression of MCP-1 in Wnt5a group was 14.76 and 61.51 pg/ml, respectively (F = 6.78 and F = 4.67, p<0.05 or 0.01). In addition, rAAV-Wnt5a gene transfer could promote cell proliferation (F = 42.15 and F = 99.38, p<0.05 or 0.01) and chondrogenic differentiation and cartilage matrix synthesis,with a statistical significance in toluidine blue (F = 5.05, p<0.05 or 0.01) and immunohistochemical staining against type II and type X collagen (F = 20.65 and 26.47, p<0.05 or 0.01). In the 2D single-layer transwell co-culture model, the cell density of the Wnt5a group was 37.75 / μm2, with 2.40, 2.19 and 2.16 times comparing the remaining 3 groups respectively (Figure 4), while the cell proliferation capacity of the bone marrow aspirates transwell co-culture model in Wnt5a group was significantly enhanced to 99.28/ μm2, with 1.59, 1.73 and 1.91 times comparing the remaining 3 groups respectively. Moreover, Wnt5a transfection also promotes the expression of type II and Type X collagen in the bone marrow aspirates transwell co-culture model, with semi-quantitative analysis of 93.50 and 61.50, respectively, with 1.45, 1.56, 1.41 and 3.24, 3.08, 2.80 times comparing to lacZ and lacZ + KN93 and Wnt5a + KN93 group respectively (Figure 5). Conclusions: Under the condition of macrophage and MSCs 2D monolayer or aspirates transwell co-culture, rAAV-mediated overexpression of Wnt5a can promote the maintenance of cartilage homeostasis and chondrogenic differentiation of MSCs via macrophage inflammatory response,macrophages may affect cartilage homeostasis and MSCs chondrogenesis through Wnt5a signaling pathway.Fig. 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig. 3View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig. 4View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig. 5View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Chebyshev spectral variational integrator and applications

The Chebyshev spectral variational integrator (CSVI) is presented in this paper. Spectral methods have aroused great interest in approximating numerically a smooth problem for their attractive geometric convergence rates. The geometric numerical methods are praised for their excellent long-time geometric structure-preserving properties. According to the generalized Galerkin framework, we combine two methods together to construct a variational integrator, which captures the merits of both methods. Since the interpolating points of the variational integrator are chosen as the Chebyshev points, the integration of Lagrangian can be approximated by the Clenshaw-Curtis quadrature rule, and the barycentric Lagrange interpolation is presented to substitute for the classic Lagrange interpolation in the approximation of configuration variables and the corresponding derivatives. The numerical float errors of the first-order spectral differentiation matrix can be alleviated by using a trigonometric identity especially when the number of Chebyshev points is large. Furthermore, the spectral variational integrator (SVI) constructed by the Gauss-Legendre quadrature rule and the multi-interval spectral method are carried out to compare with the CSVI, and the interesting kink phenomena for the Clenshaw-Curtis quadrature rule are discovered. The numerical results reveal that the CSVI has an advantage on the computing time over the whole progress and a higher accuracy than the SVI before the kink position. The effectiveness of the proposed method is demonstrated and verified perfectly through the numerical simulations for several classical mechanics examples and the orbital propagation for the planet systems and the Solar system.

A conservative sine pseudo-spectral-difference method for multi-dimensional coupled Gross–Pitaevskii equations

In this paper, a sine pseudo-spectral-difference scheme that preserves the discrete mass and energy is presented and analyzed for the coupled Gross–Pitaevskii equations with Dirichlet boundary conditions in several spatial dimensions. The Crank–Nicolson finite difference method is employed for approximating the time derivative, and the second-order sine spectral differentiation matrix is deduced and applied in spatial discretization. Without any restrictions on the grid ratios, optimal error estimates are established by utilizing the discrete energy method and the equivalence of (semi-)norms. An accelerated algorithm is developed to speed up the numerical implementation with the help of fast sine transform. Numerical examples are tested to confirm the effectiveness and high accuracy of the method.

PHF19 mediated regulation of proliferation and invasiveness in prostate cancer cells.

The Polycomb-like protein PHF19/PCL3 associates with PRC2 and mediates its recruitment to chromatin in embryonic stem cells. PHF19 is also overexpressed in many cancers. However, neither PHF19 targets nor misregulated pathways involving PHF19 are known. Here, we investigate the role of PHF19 in prostate cancer cells. We find that PHF19 interacts with PRC2 and binds to PRC2 targets on chromatin. PHF19 target genes are involved in proliferation, differentiation, angiogenesis, and extracellular matrix organization. Depletion of PHF19 triggers an increase in MTF2/PCL2 chromatin recruitment, with a genome-wide gain in PRC2 occupancy and H3K27me3 deposition. Transcriptome analysis shows that PHF19 loss promotes deregulation of key genes involved in growth, metastasis, invasion, and of factors that stimulate blood vessels formation. Consistent with this, PHF19 silencing reduces cell proliferation, while promotes invasive growth and angiogenesis. Our findings reveal a role for PHF19 in controlling the balance between cell proliferation and invasiveness in prostate cancer.

The synergistic effect of 3D-printed microscale roughness surface and nanoscale feature on enhancing osteogenic differentiation and rapid osseointegration

Personalized precision therapy and rapid osseointegration are the main development directions of dental implants. 3D printing is a vital advanced manufacturing technology for personalized precision therapy. However, the osteogenesis of the 3D printed Ti6Al4V implants is unsatisfactory. From the bionic perspective, the hierarchical micro/nano-topography can mimic the microenvironment of the multilevel structure of natural bone tissue and may endow the implant surface with superior bioactivity. In the present study, the hierarchical micro/nano-topography was successfully fabricated by construction the nanoscale feature on 3D printed microscale roughness surface of 3D-printed Ti6Al4V implants by alkali-heat treatment and hydrothermal treatment. Then the cell biological responses in vitro and osseointegration performance in vivo were systematically evaluated. The hierarchical micro/nano-topography evidently increased the roughness, improved the hydrophilicity and accelerated the hydroxyapatite deposition and mineralization, which significantly enhanced the adhesion, differentiation and extracellular matrix mineralization of bone marrow derived mesenchymal stromal cells (BMSCs). Most importantly, the hierarchical micro/nano-topography on 3D-printed implants facilitated the new bone formation and rapid osseointegration in vivo. Our study suggested that 3D-printed implant with micro/nano-topography may be a promising candidate to be applied in orthopedic field to meet the need of customized therapy and rapid osseointegration.

Regulation of differentiation of annulus fibrosus-derived stem cells using heterogeneous electrospun fibrous scaffolds.

BackgroundTissue engineering of the annulus fibrosus (AF) shows promise as a treatment for patients with degenerative disc disease (DDD). However, it remains challenging due to the intrinsic heterogeneity of AF tissue. Fabrication of scaffolds recapitulating the specific cellular, componential, and microstructural features of AF, therefore, is critical to successful AF tissue regeneration.MethodsPoly-L-lactic acid (PLLA) fibrous scaffolds with various fiber diameters and orientation were prepared to mimic the microstructural characteristics of AF tissue using electrospinning technique. AF-derived stem cells (AFSCs) were cultured on the PLLA fibrous scaffolds for 7 days.ResultsThe morphology of AFSCs significantly varied when cultured on the scaffolds with various fiber diameters and orientation. AFSCs were nearly round on scaffolds with small fibers. However, they became spindle-shaped on scaffolds with large fibers. Meanwhile, upregulated expression of collagen-I gene happened in cells cultured on scaffolds with large fibers, while enhanced expression of collagen-II and aggrecan genes was seen on scaffolds with small fibers. The production of related proteins also showed similar trends. Further, culturing AFSCs on a heterogeneous scaffold by overlaying membranes with different fiber sizes led to the formation of a hierarchical structure approximating native AF tissue.ConclusionFindings from this study demonstrate that fibrous scaffolds with different fiber sizes effectively promoted the differentiation of AFSCs into specific cells similar to the types of cells at various AF zones. It also provides a valuable reference for regulation of cell differentiation and fabrication of engineered tissues with complex hierarchical structures using the physical cues of scaffolds.The translational potential of this articleEffective AF repair is an essential need for treating degenerative disc disease. Tissue engineering is a promising approach to achieving tissue regeneration and restoring normal functions of tissues. By mimicking the key structural features of native AF tissue, including fiber size and alignment, this study deciphered the effect of scaffold materials on the cell differentiation and extracellular matrix deposition, which provides a solid basis for designing new strategies toward more effective AF repair and regeneration.

Microenvironmental Alterations in Carbon Nanotube-Induced Lung Inflammation and Fibrosis.

Carbon nanotube (CNT)-induced pulmonary inflammation and fibrosis have been intensively observed and characterized in numerous animal studies in the past decade. Remarkably, CNT-induced fibrotic lesions highly resemble some human fibrotic lung diseases, such as IPF and pneumoconiosis, regarding disease development and pathological features. This notion leads to a serious concern over the health impact of CNTs in exposed human populations, considering the rapidly expanding production of CNT materials for diverse industrial and commercial applications, and meanwhile provides the rationale for exploring CNT-induced pathologic effects in the lung. Accumulating mechanistic understanding of CNT lung pathology at the systemic, cellular, and molecular levels has demonstrated the potential of using CNT-exposed animals as a new disease model for the studies on inflammation, fibrosis, and the interactions between these two disease states. Tissue microenvironment plays critical roles in maintaining homeostasis and physiological functions of organ systems. When aberrant microenvironment forms under intrinsic or extrinsic stimulation, tissue abnormality, organ dysfunction, and pathological outcomes are induced, resulting in disease development. In this article, the cellular and molecular alterations that are induced in tissue microenvironment and implicated in the initiation and progression of inflammation and fibrosis in CNT-exposed lungs, including effector cells, soluble mediators, and functional events exemplified by cell differentiation and extracellular matrix (ECM) modification, are summarized and discussed. This analysis would provide new insights into the mechanistic understanding of lung inflammation and fibrosis induced by CNTs, as well as the development of CNT-exposed animals as a new model for human lung diseases.