Control Cell Adhesion Research Articles

Gradient Functionalization of Poly(lactic acid)-Based Materials with Polylysine for Spatially Controlled Cell Adhesion.

The development of biomaterials with gradient surface modification capable of spatially controlled cell adhesion and migration is of great importance for tissue engineering and regeneration. In this study, we proposed a method for the covalent modification of PLA-based materials with a cationic polypeptide (polylysine, PLys) via a thiol-ene click reaction carried out under a light gradient. With this aim, PLA-based films were fabricated and modified with 2-aminoethyl methacrylate (AEMA) as a double bond source. The latter was introduced by reacting pre-formed and activated surface carboxyl groups with the amino group of AEMA. The success of the modification was confirmed by 1H NMR, Raman and X-ray photoelectron spectroscopy data. A further photoinduced thiol-ene click reaction in the presence of a photosensitive initiator as a radical source was further optimized using cysteine. For grafting of PLys via the thiol-ene click reaction, PLys with a terminal thiol group was synthesized by ring-opening polymerization using Cys(Acm) as an amine initiator. Deprotection of the polypeptide resulted in the formation of free thiol groups of Cys-PLys. Successful gradient grafting of Cys-PLys was evidenced by covalent staining with the fluorescent dye Cy3-NHS. In addition, PLys gradient-dependent adhesion and migration of HEK 293 cells on PLys-PLA-based surfaces was confirmed.

Advances and Challenges of Bioassembly Strategies in Neurovascular In Vitro Modeling: An Overview of Current Technologies with a Focus on Three-Dimensional Bioprinting.

Bioassembly encompasses various techniques such as bioprinting, microfluidics, organoids, and self-assembly, enabling advances in tissue engineering and regenerative medicine. Advancements in bioassembly technologies have enabled the precise arrangement and integration of various cell types to more closely mimic the complexity functionality of the neurovascular unit (NVU) and that of other biodiverse multicellular tissue structures. In this context, bioprinting offers the ability to deposit cells in a spatially controlled manner, facilitating the construction of interconnected networks. Scaffold-based assembly strategies provide structural support and guidance cues for cell growth, enabling the formation of complex bio-constructs. Self-assembly approaches utilize the inherent properties of cells to drive the spontaneous organization and interaction of neuronal and vascular components. However, recreating the intricate microarchitecture and functional characteristics of a tissue/organ poses additional challenges. Advancements in bioassembly techniques and materials hold great promise for addressing these challenges. The further refinement of bioprinting technologies, such as improved resolution and the incorporation of multiple cell types, can enhance the accuracy and complexity of the biological constructs; however, developing bioinks that support the growth of cells, viability, and functionality while maintaining compatibility with the bioassembly process remains an unmet need in the field, and further advancements in the design of bioactive and biodegradable scaffolds will aid in controlling cell adhesion, differentiation, and vascularization within the engineered tissue. Additionally, integrating advanced imaging and analytical techniques can provide real-time monitoring and characterization of bioassembly, aiding in quality control and optimization. While challenges remain, ongoing research and technological advancements propel the field forward, paving the way for transformative developments in neurovascular research and tissue engineering. This work provides an overview of the advancements, challenges, and future perspectives in bioassembly for fabricating neurovascular constructs with an add-on focus on bioprinting technologies.

Paeoniflorin regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in oxidative stressed melanocytes.

The adhesive properties of vitiligo melanocytes have decreased under oxidative stress., cytoskeleton proteins can control cell adhesion. Paeoniflorin (PF) was proved to resist hydrogen peroxide (H2O2)-induced oxidative stress in melanocytes via nuclear factorE2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This study was to investigate whether PF exerts anti-oxidative effect through influencing cytoskeleton markers or potential signaling pathway. Human Oxidative Stress Plus array was used to identify the differentially expressed genes between H2O2 + PF group and H2O2 only group, in PIG1 and PIG3V melanocyte cell lines respectively. Western blotting was used to verify the PCR array results and to test the protein expression levels of cytoskeleton markers including Ras homolog family member A (RhoA), Rho-associated kinase 1 (ROCK1) and antioxidative marker Nrf2. Small interfering RNA was used to knock down PDZ and LIM domain 1 (PDLIM1). PF increased the expressions of PDLIM1, RhoA and ROCK1 in H2O2-induced PIG1, in contrast, decreased the expressions of PDLIM1 and ROCK1 in H2O2-induced PIG3V. Knockdown of PDLIM1 increased the expressions of RhoA and Nrf2 in PF-pretreated H2O2-induced PIG1, and ROCK1 and Nrf2 in PF-pretreated H2O2-induced PIG3V. PF regulates RhoA/ROCK1 and Nrf2 pathways in PDLIM1-dependent or independent manners in H2O2-induced melanocytes. In PIG1, PF promotes PDLIM1 to inhibit RhoA/ROCK1 pathway or activates Nrf2/HO-1 pathway, separately. In PIG3V, PF directly downregulates ROCK1 in PDLIM1-independent manner or upregulates Nrf2 dependent of PDLIM1.

Involvement of Matricellular Proteins in Cellular Senescence: Potential Therapeutic Targets for Age-Related Diseases.

Senescence is a physiological and pathological cellular program triggered by various types of cellular stress. Senescent cells exhibit multiple characteristic changes. Among them, the characteristic flattened and enlarged morphology exhibited in senescent cells is observed regardless of the stimuli causing the senescence. Several studies have provided important insights into pro-adhesive properties of cellular senescence, suggesting that cell adhesion to the extracellular matrix (ECM), which is involved in characteristic morphological changes, may play pivotal roles in cellular senescence. Matricellular proteins, a group of structurally unrelated ECM molecules that are secreted into the extracellular environment, have the unique ability to control cell adhesion to the ECM by binding to cell adhesion receptors, including integrins. Recent reports have certified that matricellular proteins are closely involved in cellular senescence. Through this biological function, matricellular proteins are thought to play important roles in the pathogenesis of age-related diseases, including fibrosis, osteoarthritis, intervertebral disc degeneration, atherosclerosis, and cancer. This review outlines recent studies on the role of matricellular proteins in inducing cellular senescence. We highlight the role of integrin-mediated signaling in inducing cellular senescence and provide new therapeutic options for age-related diseases targeting matricellular proteins and integrins.

Influence of DNA-methylation at multiple stages of limb chondrogenesis

Precise regulation of gene expression is of utmost importance during cell fate specification. DNA methylation is a key epigenetic mechanism that plays a significant role in the regulation of cell fate by recruiting repression proteins or inhibiting the binding of transcription factors to DNA to regulate gene expression. Limb development is a well-established model for understanding cell fate decisions, and the formation of skeletal elements is coordinated through a sequence of events that control chondrogenesis spatiotemporally. It has been established that epigenetic control participates in cartilage maturation. However, further investigation is required to determine its role in the earliest stages of chondrocyte differentiation. This study investigates how the DNA methylation environment affects cell fate divergence during the early chondrogenic events. Our research has shown for the first time that inhibiting DNA methylation in interdigital tissue with 5-azacytidine results in the formation of an ectopic digit. This discovery suggested that DNA methylation dynamics could regulate the fate of cells between chondrogenesis and cell death during autopod development. Our in vitro findings indicate that DNA methylation at the early stages of chondrogenesis is integral in regulating condensation by controlling cell adhesion and proapoptotic genes. As a result, the dynamics of methylation and demethylation are crucial in governing chondrogenesis and cell death during different stages of limb chondrogenesis.

Nuclear deformation and cell division of single cell on elongated micropatterned substrates fabricated by DMD lithography

Cells sense mechanical signals from the surrounding environment and transmit them to the nucleus through mechanotransduction to regulate cellular behavior. Microcontact printing, which utilizes elastomer stamps, is an effective method for simulating the cellular microenvironment and manipulating cell morphology. However, the conventional fabrication process of silicon masters and elastomer stamps requires complex procedures and specialized equipment, which restricts the widespread application of micropatterning in cell biology and hinders the investigation of the role of cell geometry in regulating cell behavior. In this study, we present an innovative method for convenient resin stamp microfabrication based on digital micromirror device planar lithography. Using this method, we generated a series of patterns ranging from millimeter to micrometer scales and validated their effectiveness in controlling adhesion at both collective and individual cell levels. Additionally, we investigated mechanotransduction and cell behavior on elongated micropatterned substrates. We then examined the effects of cell elongation on cytoskeleton organization, nuclear deformation, focal adhesion formation, traction force generation, nuclear mechanics, and the growth of HeLa cells. Our findings reveal a positive correlation between cell length and mechanotransduction. Interestingly, HeLa cells with moderate length exhibit the highest cell division and proliferation rates. These results highlight the regulatory role of cell elongation in mechanotransduction and its significant impact on cancer cell growth. Furthermore, our methodology for controlling cell adhesion holds the potential for addressing fundamental questions in both cell biology and biomedical engineering.

Differential Competitive Growth of Transgenic Subclones of Neuroblastoma Cells Expressing Different Levels of Cathepsin D Co-Cultured in 2D and 3D in Response to EGF: Implications in Tumor Heterogeneity and Metastasis.

Neuroblastoma (NB) is an embryonal tumor arising from the sympathetic central nervous system. The epidermal growth factor (EGF) plays a role in NB growth and metastatic behavior. Recently, we have demonstrated that cathepsin D (CD) contrasts EGF-induced NB cell growth in 2D by downregulating EGFR/MAPK signaling. Aggressive NB is highly metastatic to the bone and the brain. In the metastatic process, adherent cells detach to form clusters of suspended cells that adhere once they reach the metastatic site and form secondary colonies. Whether CD is involved in the survival of metastatic NB clones is not known. Therefore, in this study, we addressed how CD differentially affects cell growth in suspension versus the adherent condition. To mimic tumor heterogeneity, we co-cultured transgenic clones silenced for or overexpressing CD. We compared the growth kinetics of such mixed clones in 2D and 3D models in response to EGF, and we found that the Over CD clone had an advantage for growth in suspension, while the CD knocked-down clone was favored for the adherent growth in 2D. Interestingly, on switching from 3D to 2D culture conditions, the expression of E-cadherin and of N-cadherin increased in the KD-CD and Over CD clones, respectively. The fact that CD plays a dual role in cancer cell growth in 2D and 3D conditions indicates that during clonal evolution, subclones expressing different level of CD may arise, which confers survival and growth advantages depending on the metastatic step. By searching the TCGA database, we found up to 38 miRNAs capable of downregulating CD. Interestingly, these miRNAs are associated with biological processes controlling cell adhesion and cell migration. The present findings support the view that during NB growth on a substrate or when spreading as floating neurospheres, CD expression is epigenetically modulated to confer survival advantage. Thus, epigenetic targeting of CD could represent an additional strategy to prevent NB metastases.

Focal adhesions contain three specialized actin nanoscale layers

Focal adhesions (FAs) connect inner workings of cell to the extracellular matrix to control cell adhesion, migration and mechanosensing. Previous studies demonstrated that FAs contain three vertical layers, which connect extracellular matrix to the cytoskeleton. By using super-resolution iPALM microscopy, we identify two additional nanoscale layers within FAs, specified by actin filaments bound to tropomyosin isoforms Tpm1.6 and Tpm3.2. The Tpm1.6-actin filaments, beneath the previously identified α-actinin cross-linked actin filaments, appear critical for adhesion maturation and controlled cell motility, whereas the adjacent Tpm3.2-actin filament layer beneath seems to facilitate adhesion disassembly. Mechanistically, Tpm3.2 stabilizes ACF-7/MACF1 and KANK-family proteins at adhesions, and hence targets microtubule plus-ends to FAs to catalyse their disassembly. Tpm3.2 depletion leads to disorganized microtubule network, abnormally stable FAs, and defects in tail retraction during migration. Thus, FAs are composed of distinct actin filament layers, and each may have specific roles in coupling adhesions to the cytoskeleton, or in controlling adhesion dynamics.

Synthesis of Superabsorbent Hydrogels with Predefined Geometries and Controlled Swelling Properties for Versatile 3D Cell Culture Scaffolds.

This research presents a simple but general method to prepare water-soluble-polymer-based superabsorbent hydrogels with predefined microscale geometries and controlled swelling properties. Unlike conventional hydrogel preparation methods based on bulk solution-phase cross-linking, poly(vinyl alcohol) is homogeneously mixed with polymer-based cross-linkers in the solution phase and thermally cross-linked in the solid phase after drying; the degree of cross-linking is modulated by controlling the cross-linker concentration, pH, and/or thermal annealing conditions. After the shape definition process, cross-linked films or electrospun nanofibers are treated with sulfuric acid to weaken hydrogen bonds and introduce sulfate functionality in polymer crystallites. The resultant superabsorbent hydrogels exhibit an isotropic expansion of the predefined geometry and tunable swelling properties. Particularly, hydrogel microfibers exhibit excellent optical transparency, good biocompatibility, large porosity, and controlled cell adhesion, leading to versatile 3D cell culture scaffolds that not only support immortalized cell lines and primary neurons but also enable stiffness-modulated cell adhesion studies.

Modeling the evolution of membrane during cell adhesion on the nanostructured substrate

Using nanostructured substrates for enhancing cell adhesion is an important method. However, the physical mechanism of cell adhesion on nanostructured substrate is not well understood yet, particularly the evolution process of membrane during cell adhesion. Here, we propose an analytical model to study quantitatively the evolution of membrane during adhesion process on the nanostructured substrate. The effects of substrate surface topography, receptor-ligand binding, substrate property and membrane property were investigated. We found a small nanopillar radius, low nanopillar density, large binding rate, large receptor density, low non-specific energy, or large stretching modulus can result in a large adhesion rate and a large adhesion depth. Besides, the evolution of membrane on truncated nanocone arrays was also studied by the model. The theoretical results are in good agreement with the experimental observations, which implied that our studies can provide a useful guide to control cell adhesion process and cell motion on nanostructured substrates.

Modeling evolution of cell morphology under stretching.

The mechanical stimulation of cells from the surrounding environment is an important life activity. However, there has been a lack of dynamically quantitative analysis of cell morphology under mechanical stimulations. A theoretical model for the evolution of cell morphology under stretching is proposed by analyzing the transformation between cell deformation energy and adhesion energy. The images of the evolution show that detachment of the adhesion membrane or re-adhesion of the cell, causes a decrease or increase of the adhesion area, respectively. In addition to the stretching amplitude and velocity, we found that the duration of the stretching stage and the no stretching stage can affect the cell morphology during cyclic stretching. The theoretical model explains some counter-intuitive experimental results and provides many quantitative insights into understanding the physical mechanisms of cell adhesion under stretching. This study can provide a useful guide to control cell adhesion under mechanical stimulations.

Thy-1 (CD90)-regulated cell adhesion and migration of mesenchymal cells: insights into adhesomes, mechanical forces, and signaling pathways

Cell adhesion and migration depend on the assembly and disassembly of adhesive structures known as focal adhesions. Cells adhere to the extracellular matrix (ECM) and form these structures via receptors, such as integrins and syndecans, which initiate signal transduction pathways that bridge the ECM to the cytoskeleton, thus governing adhesion and migration processes. Integrins bind to the ECM and soluble or cell surface ligands to form integrin adhesion complexes (IAC), whose composition depends on the cellular context and cell type. Proteomic analyses of these IACs led to the curation of the term adhesome, which is a complex molecular network containing hundreds of proteins involved in signaling, adhesion, and cell movement. One of the hallmarks of these IACs is to sense mechanical cues that arise due to ECM rigidity, as well as the tension exerted by cell-cell interactions, and transduce this force by modifying the actin cytoskeleton to regulate cell migration. Among the integrin/syndecan cell surface ligands, we have described Thy-1 (CD90), a GPI-anchored protein that possesses binding domains for each of these receptors and, upon engaging them, stimulates cell adhesion and migration. In this review, we examine what is currently known about adhesomes, revise how mechanical forces have changed our view on the regulation of cell migration, and, in this context, discuss how we have contributed to the understanding of signaling mechanisms that control cell adhesion and migration.

Golgi ELMO1 binds QUA1, QUA2, GAUT9, and ELMO4 and is required for pectin accumulation in Arabidopsis.

Pectin and its modification influence the plasticity and strength of the plant cell wall controlling cell adhesion, size, shape, and pathogen resistance. The Golgi membrane anchored QUA1, QUA2, and GAUT9 Golgi enzymes synthesize and esterify pectin, which is then secreted and selectively de-esterified to potentiate structure influencing crosslinks in the cell wall. Mutations in members of the family of non-enzymatic ELMO Golgi membrane proteins lead to a reduction of pectin levels, cell adhesion, and hypocotyl tensile strength. Results from immunoprecipitation of Golgi protein complexes reveal that ELMO1-GFP is associated with pectin biosynthesis and modifying enzymes QUA1, QUA2, and GAUT9. In a yeast two and three hybrid assay, ELMO1 can bind directly to QUA1, GAUT9 or ELMO4, but QUA1, QUA2 or GAUT9 do not bind to each other. A yeast 3 hybrid assay provides evidence that ELMO1 can mediate the binding of QUA1 and QUA2. Taken together, these results indicate that the 20 kDa ELMO1 serves to facilitate some aspect of pectin synthesis and modification that leads to sufficient accumulation to allow cell adhesion, and we speculate that ELMOs help to scaffold key enzymes in this process.

Upregulation of circ_0080968 in diabetic foot ulcer inhibits wound healing via repressing the migration and promoting proliferation of keratinocytes

BackgroundDiabetic foot ulcer (DFU) is a serious chronic complication of diabetes mellitus whose pathogenesis remains unclear. Circular RNA (circRNA) refers to a group of covalently closed non-coding RNAs that are reported to be dysregulated in patients with DFU. However, the mechanism whereby dysregulation in circRNAs contributes to DFU remains unclear. In this study, we investigated the role of dysregulated circRNAs in DFU. Materials and methodsA gene expression dataset was downloaded from the Gene Expression Omnibus portal and analyzed by the limma package of R. The levels of 24 upregulated circRNAs were detected in two independent cohorts by RT-qPCR. Interactions between miRNAs and circRNAs were predicted through bioinformatics and confirmed using a dual luciferase assay. The circularity and subcellular localization of circRNA-080968 was examined by northern blotting after digestion with RNase-R and in situ hybridization. Cell migration and proliferation were examined using Transwell and MTT assays. The apoptotic cells were detected by flow cytometry. ResultsThe level of circRNA-080968 was upregulated in DFU tissues compared to that of non-DFU samples and normal human wounds. CircRNA-080968 was mainly localized in the cytoplasm and its overexpression inhibited the migration and promoted the proliferation of keratinocytes. MiR-326 and miR-766-3p were identified to interact with and be negatively correlated with circRNA-080968 levels. Increased glucose upregulated circRNA-080968, and its overexpression accelerated the degradation of both miR-326 and miR-766-3p. Reduced levels of miR-326 and miR-766-3p upregulated the expression of several genes controlling cell adhesion and proliferation which are related to the pathogenesis of DFU. ConclusionsThe upregulation of circRNA-080968 in DFU induced the degradation of miR-326 and miR-766-3p, which further repressed the migration and increased the proliferation of keratinocytes.

Optimal cell traction forces in a generalized motor-clutch model

Cells exert forces on mechanically compliant environments to sense stiffness, migrate, and remodel tissue. Cells can sense environmental stiffness via myosin-generated pulling forces acting on F-actin, which is in turn mechanically coupled to the environment via adhesive proteins, akin to a clutch in a drivetrain. In this “motor-clutch” framework, the force transmitted depends on the complex interplay of motor, clutch, and environmental properties. Previous mean-field analysis of the motor-clutch model identified the conditions for optimal stiffness for maximal force transmission via a dimensionless number that combines motor-clutch parameters. However, in this and other previous mean-field analyses, the motor-clutch system is assumed to have balanced motors and clutches and did not consider force-dependent clutch reinforcement and catch bond behavior. Here, we generalize the motor-clutch analytical framework to include imbalanced motor-clutch regimes, with clutch reinforcement and catch bonding, and investigate optimality with respect to all parameters. We found that traction force is strongly influenced by clutch stiffness, and we discovered an optimal clutch stiffness that maximizes traction force, suggesting that cells could tune their clutch mechanical properties to perform a specific function. The results provide guidance for maximizing the accuracy of cell-generated force measurements via molecular tension sensors by designing their mechanosensitive linker peptide to be as stiff as possible. In addition, we found that, on rigid substrates, the mean-field analysis identifies optimal motor properties, suggesting that cells could regulate their myosin repertoire and activity to maximize force transmission. Finally, we found that clutch reinforcement shifts the optimum substrate stiffness to larger values, whereas the optimum substrate stiffness is insensitive to clutch catch bond properties. Overall, our work reveals novel features of the motor-clutch model that can affect the design of molecular tension sensors and provide a generalized analytical framework for predicting and controlling cell adhesion and migration in immunotherapy and cancer.

Polysaccharides and Structural Proteins as Components in Three-Dimensional Scaffolds for Breast Cancer Tissue Models: A Review

Breast cancer is the most common cancer among women, and even though treatments are available, efficiency varies with the patients. In vitro 2D models are commonly used to develop new treatments. However, 2D models overestimate drug efficiency, which increases the failure rate in later phase III clinical trials. New model systems that allow extensive and efficient drug screening are thus required. Three-dimensional printed hydrogels containing active components for cancer cell growth are interesting candidates for the preparation of next generation cancer cell models. Macromolecules, obtained from marine- and land-based resources, can form biopolymers (polysaccharides such as alginate, chitosan, hyaluronic acid, and cellulose) and bioactive components (structural proteins such as collagen, gelatin, and silk fibroin) in hydrogels with adequate physical properties in terms of porosity, rheology, and mechanical strength. Hence, in this study attention is given to biofabrication methods and to the modification with biological macromolecules to become bioactive and, thus, optimize 3D printed structures that better mimic the cancer cell microenvironment. Ink formulations combining polysaccharides for tuning the mechanical properties and bioactive polymers for controlling cell adhesion is key to optimizing the growth of the cancer cells.

LRP12 is an endogenous transmembrane inactivator of α4 integrins

Dynamic regulation of integrin activation and inactivation is critical for precisely controlled cell adhesion and migration in physiological and pathological processes. The molecular basis for integrin activation has been intensively studied; however, the understanding of integrin inactivation is still limited. Here, we identify LRP12 as an endogenous transmembrane inhibitor for α4 integrin activation. The LRP12 cytoplasmic domain directly binds to the integrin α4 cytoplasmic tail and inhibits talin binding to the β subunit, thus keeping integrin inactive. In migrating cells, LRP12-α4 interaction induces nascent adhesion (NA) turnover at the leading-edge protrusion. Knockdown of LRP12 leads to increased NAs and enhanced cell migration. Consistently, LRP12-deficient Tcells show an enhanced homing capability in mice and lead to aggravated chronic colitis in a Tcell-transfer colitis model. Altogether, LRP12 is a transmembrane inactivator for integrins that inhibits α4 integrin activation and controls cell migration by maintaining balanced NA dynamics.

All-Trans Retinoic Acid Reduces Matrix Metalloproteinase-2 and Increases E-Cadherin Levels in BeWo Choriocarcinoma Cells

Background: Choriocarcinoma is a malignant trophoblastic tumor that can degrade the uterine basement membrane to facilitate local and distant metastasis. Matrix metalloproteinase-2 (MMP-2) is a vital proteinase produced by trophoblasts and can cleave type IV collagen in the basement membrane of the uterine epithelium. In addition, E-cadherin controls cell adhesion, which is associated with tumorprogression, and loss of E-cadherin function is associated with metastasis. Vitamin A analogues, including all-trans retinoic acid (ATRA), exhibit anticancer properties, including metastasis inhibition.This study aimed to investigate the ability of ATRA to prevent trophoblast invasion and metastasis in choriocarcinoma by assessing MMP-2 and E-cadherin activity. Methods: This study administered various doses of ATRA to the BeWo (American Type Culture Collection CCL-98) choriocarcinoma cell line and assessed MMP-2 and E-cadherin activity through flow cytometry. The research was performed at the Biomedical Laboratory of the Faculty of Medicine of Universitas Brawijaya Malang, East Java, Indonesia. Results: BeWo cells were exposed to 0, 50, 100, 200, 400, or 800 μg/mL ATRA. MMP-2 was downregulated after ATRA treatment. The greatest reduction in MMP-2 level was observed after 200 μg/mL ATRA treatment, but this result was not statistically significant (P = 0.550). However, ATRA treatment significantly reduced the number of BeWo cells with low E-cadherin levels (P = 0.012). Conclusion: ATRA downregulates MMP-2 and upregulates E-cadherin. Further in vitro and animal studies are required to evaluate the ability of ATRA to inhibit metastasis. Bangladesh Journal of Medical Science Vol. 22 No. 02 April’23 Page : 336-340

Proteomic landscape of the extracellular matrix in the fibrotic kidney

The extracellular matrix (ECM) is a complex three-dimensional network of proteins surrounding cells, forming a niche that controls cell adhesion, proliferation, migration and differentiation. The ECM network provides an architectural scaffold for surrounding cells and undergoes dynamic changes in composition and contents during the evolution of chronic kidney disease (CKD). Here, we unveiled the proteomic landscape of the ECM by delineating proteome-wide and ECM-specific alterations in normal and fibrotic kidneys. Decellularized kidney tissue scaffolds were made and subjected to proteomic profiling by liquid chromatography with tandem mass spectrometry. A total of 172 differentially expressed proteins were identified in these scaffolds from mice with CKD. Through bioinformatics analysis and experimental validation, we identified a core set of nine signature proteins, which could play a role in establishing an oxidatively stressed, profibrotic, proinflammatory and antiangiogenetic microenvironment. Among these nine proteins, glutathione peroxidase 3 (GPX3) was the only protein with downregulated expression during CKD. Knockdown of GPX3 invivo augmented ECM expression and aggravated kidney fibrotic lesions after obstructive injury. Transcriptomic profiling revealed that GPX3 depletion resulted in an altered expression of the genes enriched in hypoxia pathway. Knockdown of GPX3 induced NADPH oxidase 2 expression, promoted kidney generation of reactive oxygen species and activated p38 mitogen-activated protein kinase. Conversely, overexpression of exogenous GPX3 alleviated kidney fibrosis, inhibited NADPH oxidase 2 and p38 mitogen-activated protein kinase. These findings suggest that oxidative stress is a pivotal element of the fibrogenic microenvironment. Thus, our studies represent a comprehensive proteomic characterization of the ECM in the fibrotic kidney and provide novel insights into molecular composition of the fibrogenic microenvironment.

THE ROLE AND IMPORTANCE OF GALECTIN-3 IN COLON CARCINOMA METASTASIS

Objective: Galectin-3 is an endogenous β-galactoside binding protein which is an S-type lectin family member with intracellular and extracellular localization and has certain tasks for controlling cell adhesion, growth, proliferation, differentiation, migration, and apoptosis. In this study we aimed to elucidate the role of galectin-3 expression in metastasis biology and its role in predicting tumor metastasis in colon carcinomas.
 Materials and Method: In this research, 80 cases with colon adenocarcinoma containing the transition of the normal mucosa-tumor tissue were included. The expression of galectin-3 in these cases was investigated immuno-histochemically.
 Results: There was no significant relationship between Galectin-3 expression and age, gender, histological type, and histological grade, but there was a significant increase in the amount of galectin-3 expression while the histological grade increased. Galectin-3 expression of the adjacent normal mucosa and tumor was found to be significantly higher in patients with metastases than patients without metastases. There was also a correlation between the presence of vascular invasion and the increase of galectin-3 expression. The mean galectin-3 expression in metastatic foci was higher than that of the tumor area. These findings suggest that the cells with metastatic phenotype express a higher amount of galectin-3 and also galectin-3 has an indirect role in the pathogenesis of metastasis even if its place could not be determined currently.
 Conclusion: In our study, it was concluded that the expression of galectin-3 may play a role in the metastatic process of colon carcinomas.