Insights into the key roles of epigenetics in matrix macromolecules-associated wound healing

A Rheological Study on the Effect of Tethering Pro- and Anti-Inflammatory Cytokines into Hydrogels on Human Mesenchymal Stem Cell Migration, Degradation, and Morphology

Polymer-peptide hydrogels are being designed as implantable materials that deliver human mesenchymal stem cells (hMSCs) to treat wounds. Most wounds can progress through the healing process without intervention. During the normal healing process, cytokines are released from the wound to create a concentration gradient, which causes directed cell migration from the native niche to the wound site. Our work takes inspiration from this process and uniformly tethers cytokines into the scaffold to measure changes in cell-mediated degradation and motility. This is the first step in designing cytokine concentration gradients into the material to direct cell migration. We measure changes in rheological properties, encapsulated cell-mediated pericellular degradation and migration in a hydrogel scaffold with covalently tethered cytokines, either tumor necrosis factor-α (TNF-α) or transforming growth factor-β (TGF-β). TNF-α is expressed in early stages of wound healing causing an inflammatory response. TGF-β is released in later stages of wound healing causing an anti-inflammatory response in the surrounding tissue. Both cytokines cause directed cell migration. We measure no statistically significant difference in modulus or the critical relaxation exponent when tethering either cytokine in the polymeric network without encapsulated hMSCs. This indicates that the scaffold structure and rheology is unchanged by the addition of tethered cytokines. Increases in hMSC motility, morphology and cell-mediated degradation are measured using a combination of multiple particle tracking microrheology (MPT) and live-cell imaging in hydrogels with tethered cytokines. We measure that tethering TNF-α into the hydrogel increases cellular remodeling on earlier days postencapsulation and tethering TGF-β into the scaffold increases cellular remodeling on later days. We measure tethering either TGF-β or TNF-α enhances cell stretching and, subsequently, migration. This work provides rheological characterization that can be used to design new materials that present chemical cues in the pericellular region to direct cell migration.

An Immune-Regulating Polysaccharide Hybrid Hydrogel with Mild Photothermal Effect and Anti-Inflammatory for Accelerating Infected Wound Healing

Bacterial infections and excessive inflammation present substantial challenges for clinical wound healing. Hydrogels with mild photothermal (PTT) effects have emerged as promising agents owing to their dual actions: positive effects on cells and negative effects on bacteria. Here, an injectable self-healing hydrogel of oxidized konjac glucomannan/arginine-modified chitosan (OKGM/CS-Arg, OC) integrated with protocatechualdehyde-@Fe (PF) nanoparticles capable of effectively absorbing near-infrared radiation is synthesized successfully. The OC/PF hydrogels exhibit excellent mechanical properties, biocompatibility, and antioxidant activity. Moreover, in synergy with PTT, OC/PF demonstrates potent antibacterial effects while concurrently stimulating cell migration and new blood vessel formation. In methicillin-resistant Staphylococcus aureus-infected full-thickness mouse wounds, the OC/PF hydrogel displays remarkable antibacterial and anti-inflammatory activities, and accelerates wound healing by regulating the wound immune microenvironment and promoting M2 macrophage polarization. Consequently, the OC/PF hydrogel represents a novel therapeutic approach for treating multidrug-resistant bacterial infections and offers a technologically advanced solution for managing infectious wounds in clinical settings.

Epigenetic modification: A novel insight into diabetic wound healing

Wound healing is an intricate and fine regulatory process. In diabetic patients, advanced glycation end products (AGEs), excessive reactive oxygen species (ROS), biofilm formation, persistent inflammation, and angiogenesis regression contribute to delayed wound healing. Epigenetics, the fast-moving science in the 21st century, has been up to date and associated with diabetic wound repair. In this review, we go over the functions of epigenetics in diabetic wound repair in retrospect, covering transcriptional and posttranscriptional regulation. Among these, we found that histone modification is widely involved in inflammation and angiogenesis by affecting macrophages and endothelial cells. DNA methylation is involved in factors regulation in wound repair but also affects the differentiation phenotype of cells in hyperglycemia. In addition, noncodingRNA regulation and RNA modification in diabetic wound repair were also generalized. The future prospects for epigenetic applications are discussed in the end. In conclusion, the study suggests that epigenetics is an integral regulatory mechanism in diabetic wound healing.

Unraveling the Intricate Network of lncRNAs in Corneal Epithelial Wound Healing: Insights Into the Regulatory Role of linc17500

Purpose

Epigenetic mechanisms orchestrate a harmonious process of corneal epithelial wound healing (CEWH). However, the precise role of long non-coding RNAs (lncRNAs) as key epigenetic regulators in mediating CEWH remains elusive. Here, we aimed to elucidate the functional contribution of lncRNAs in regulating CEWH.

Methods

We used a microarray to characterize lncRNA expression profiling during mouse CEWH. Subsequently, the aberrant lncRNAs and their cis-associated genes were subjected to comprehensive Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blot analyses were performed to determine the expression profiles of key markers during CEWH. The in vivo effects of linc17500 on this process were investigated through targeted small interfering RNA (siRNA) injection. Post-siRNA treatment, corneal re-epithelialization was assessed, alongside the expression of cytokeratins 12 and 14 (Krt12 and Krt14) and Ki67. Effects of linc17500 on mouse corneal epithelial cell (TKE2) proliferation, cell cycle, and migration were assessed by multicellular tumor spheroids (MTS), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and scratch-wound assay, respectively.

Results

Microarray analysis revealed dysregulation of numerous lncRNA candidates during CEWH. Bioinformatic analysis provided valuable annotations regarding the cis-associated genes of these lncRNAs. In vivo experiments demonstrated that knockdown of linc17500 resulted in delayed CEWH. Furthermore, the knockdown of linc17500 and its cis-associated gene, CDC28 protein kinase regulatory subunit 2 (Cks2), was found to impede TKE2 cell proliferation and migration. Notably, downregulation of linc17500 in TKE2 cells led to suppression of the activation status of Akt and Rb.

Conclusions

This study sheds light on the significant involvement of lncRNAs in mediating CEWH and highlights the regulatory role of linc17500 on TKE2 cell behavior.

Translational Relevance

These findings provide valuable insights for future therapeutic research aimed at addressing corneal wound complications.

Preparation of Multi-Functional Quaternary Ammonium Chitosan/Surfactin Hydrogel and its Application in Wound Management

Hydrogel with a 3D network structure can cover the wound to stop the bleeding and support the host tissue infiltration and integration. In this study, an antibacterial hydrogel with hemostasis and the ability to promote wound healing is proposed. This hydrogel comprised surfactin, polyvinylpyrrolidone, and methacrylic anhydride (MA) grafted quaternary ammonium chitosan (CS-MA). The hydrogel formation is triggered by the ultraviolet-initiated polymerization of CS-MA, while the surfactin is complexed with the hydrogel through hydrogen bonding interaction. The results showed that this hydrogel is an adhesive hydrogel with shape adaptability, which can cover the wound surface and promote contact between the hydrogel and the wound surface. More importantly, this hydrogel can simulate the microenvironment of the primary extracellular matrix and increase collagen deposition, and inflammatory factor transformation. The designing of such a multi-functional hydrogel is expected to provide a novel approach to promoting the healing of wounds.

Stimuli-responsive probes for amplification-based imaging of miRNAs in living cells

MicroRNAs (miRNAs) have emerged as important biomarkers in biomedicine and bioimaging due to their roles in various physiological and pathological processes. Real-time and in situ monitoring of dynamic fluctuation of miRNAs in living cells is crucial for understanding these processes. However, current miRNA imaging probes still have some limitations, including the lack of effective amplification methods for low abundance miRNAs bioanalysis and uncontrollable activation, leading to background signals and potential false-positive results. Therefore, researchers have been integrating activatable devices with miRNA amplification techniques to design stimuli-responsive nanoprobes for "on-demand" and precise imaging of miRNAs in living cells. In this review, we summarize recent advances of stimuli-responsive probes for the amplification-based imaging of miRNAs in living cells and discuss the future challenges and opportunities in this field, aiming to provide valuable insights for accurate disease diagnosis and monitoring.

The role of matrix stiffness in breast cancer progression: a review

The significance of matrix stiffness in cancer development has been investigated in recent years. The gradual elastic force the extracellular matrix imparts to cells, known as matrix stiffness, is one of the most important types of mechanical stimulation. Increased matrix stiffness alters the biological activity of cells, which promotes the growth of numerous malignancies, including breast cancer. Comprehensive studies have demonstrated that increasing matrix stiffness activates molecular signaling pathways that are closely linked to breast cancer progression. There are many articles exploring the relationship between mechanism hardness and breast cancer, so we wanted to provide a systematic summary of recent research advances. In this review, we briefly introduce the mechanism of matrix stiffness in breast cancer, elaborate on the effect of extracellular matrix stiffness on breast cancer biological behavior and signaling pathways, and finally, we will talk about breast cancer treatment that focuses on matrix stiffness.

Manganese-Iron Dual Single-Atom Catalyst with Enhanced Nanozyme Activity for Wound and Pustule Disinfection

Even though great progress has been achieved in mimicking natural enzyme engineering, few artificial enzymes with efficient catalytic performance and multifunction have been reported. In this study, novel manganese-iron dual single-atom catalysts (Mn/Fe SACs) were synthesized via a hydrothermal/pyrolysis recipe. Iron atoms inside the Mn/Fe SACs adequately exerted the peroxidase (POD)-like activity, its Michaelis-Menten constant, and maximum initial velocity superior to the horseradish peroxidase. Manganese atoms sufficiently catalyzed the H2O2 to generate oxygen (O2), which alleviated the challenge of the continued lack of O2 in the infected wound. In addition, Mn/Fe SACs possess a glutathione oxidase-like activity that further enhanced POD-like activity in the therapeutic process. The antibacterial rates of Mn/Fe SACs were 95 and 94.5% for Escherichia coli and Staphylococcus aureus, respectively. In vitro anti-inflammatory experiments demonstrated that Mn/Fe SACs could regulate the polarization of macrophages into the anti-inflammatory M2 subtype. In vivo wound healing experiments suggested that the combination therapy of Mn/Fe SACs and chemodynamic therapy presented a great promotion of the recovery rate. Moreover, the O2 generated by the catalase-like process contributed to the catalysts permeating the interior of the infected wounds and achieved preferable abscess elimination ability. This work revealed the potential of Mn/Fe SACs as broad-spectrum antimicrobial materials, which provided a novel strategy for treating infected and abscess wounds.

Alginate/polyvinyl alcohol films for wound healing: Advantages and challenges

The skin is the largest organ in the human body and its physical integrity must be maintained for body homeostasis and to prevent the entry of pathogenic microorganisms. Sodium alginate (SA) and polyvinyl alcohol (PVA) are two polymers widely used in films for wound dressing applications. Furthermore, blends between SA and PVA improve physical, mechanical and biological properties of the final wound healing material when compared to the individual polymers. Different drugs have been incorporated into SA/PVA-based films to improve wound healing activity. It is noteworthy that SA/PVA films can be crosslinked with Ca²⁺ or other agents, which improves physicochemical and biological properties. Thus, SA/PVA associations are promising for the biomedical field, as a potential alternative for wound treatment. This review focuses on the main techniques for obtaining SA/PVA films, their physical-chemical characterization, drug incorporation, and the advantages and challenges of these films for wound healing.

Proteoglycan Expression Studied by MicroRNAs

MicroRNAs are small noncoding RNAs that regulate gene expression at the posttranscriptional level. Proteoglycans are glycoproteins characterized by covalent attachment of a glycosaminoglycan chain, which have been identified as regulatory targets of microRNAs in a physiological and pathophysiological context. We present a strategy and detailed methods for the functional analysis of microRNA regulation of proteoglycans using human cancer cells as an application example. The experimental setup includes in silico microRNA target prediction, transfection of cancer cells with microRNA precursors, validation of target regulation by qPCR, flow cytometry and luciferase reporter assays, and an example for functional analysis and phenotype confirmation by complementation analysis.

Evaluating the Effects of MicroRNAs on Proteoglycans and Matrix Constituents' Expression and Functional Properties

Circulating microRNAs (miRNAs) possess significant roles in normal homeostasis and disease conditions, including cardiovascular diseases, fibrosis, inflammatory response, and cancer. Secreted miRNAs, via the membrane vesicles, actively communicate with extracellular matrix (ECM) components to affect cell-cell and cell-matrix interactions, thereby affecting matrix remodeling and metabolic pathways in the recipient cells. Matrix macromolecules regulate the expression of miRNAs, and in turn miRNAs have been identified as emerging mediators of matrix constituents, serving as appealing biomarkers for many pathophysiological processes. Therefore, the expression profile of certain miRNAs highlights the importance of their targeting in several aspects of human pathologies. In this chapter, we report molecular biology protocols to determine the effects of selected miRNAs on the expression and activity of matrix biomolecules.

Landscape of the epigenetic regulation in wound healing

Wound healing after skin injury is a dynamic and highly coordinated process involving a well-orchestrated series of phases, including hemostasis, inflammation, proliferation, and tissue remodeling. Epigenetic regulation refers to genome-wide molecular events, including DNA methylation, histone modification, and non-coding RNA regulation, represented by microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA). Epigenetic regulation is pervasively occurred in the genome and emerges as a new role in gene expression at the post-transcriptional level. Currently, it is well-recognized that epigenetic factors are determinants in regulating gene expression patterns, and may provide evolutionary mechanisms that influence the wound microenvironments and the entire healing course. Therefore, this review aims to comprehensively summarize the emerging roles and mechanisms of epigenetic remodeling in wound healing. Moreover, we also pose the challenges and future perspectives related to epigenetic modifications in wound healing, which would bring novel insights to accelerated wound healing.

Efficiency of Multifunctional Antibacterial Hydrogels for Chronic Wound Healing in Diabetes: A Comprehensive Review

Diabetic chronic wounds or amputation, which are complications of diabetes mellitus (DM), are a cause of great suffering for diabetics. In addition to the lack of oxygen, elevated reactive oxygen species (ROS) and reduced vascularization, microbial invasion is also a critical factor that induces non-healing chronic diabetic wounds, ie, wounds still remaining in the stage of inflammation, after which the wound tissue begins to age and becomes necrotic. To clear up the infection, alleviate the inflammation in the wound and prevent necrosis, many kinds of hydrogel have been fabricated to eliminate infections with pathogens. The unique properties of hydrogels make them ideally suited to wound dressings because they provide a moist environment for wound healing and act as a barrier against bacteria. This review article will mainly cover the recent developments and innovations of antibacterial hydrogels for diabetic chronic wound healing.

3D Biofabrication of a Cardiac Tissue Construct for Sustained Longevity and Function

In this study, we developed three-dimensional (3D) printed annular ring-like scaffolds of hydrogel (gelatin-alginate) constructs encapsulated with a mixture of human cardiac AC16 cardiomyocytes (CMs), fibroblasts (CFs), and microvascular endothelial cells (ECs) as cardiac organoid models in preparation for investigating the role of microgravity in cardiovascular disease initiation and development. We studied the mechanical properties of the acellular scaffolds and confirmed their cell compatibility as well as heterocellular coupling for cardiac tissue engineering. Rheological analysis performed on the acellular scaffolds showed the scaffolds to be elastogenic with elastic modulus within the range of a native in vivo heart tissue. The microstructural and physicochemical properties of the scaffolds analyzed through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (ATR-FTIR) confirmed the mechanical and functional stability of the scaffolds for long-term use in in vitro cell culture studies. HL-1 cardiomyocytes bioprinted in these hydrogel scaffolds exhibited contractile functions over a sustained period of culture. Cell mixtures containing CMs, CFs, and ECs encapsulated within the 3D printed hydrogel scaffolds exhibited a significant increase in viability and proliferation over 21 days, as shown by flow cytometry analysis. Moreover, via the expression of specific cardiac biomarkers, cardiac-specific cell functionality was confirmed. Our study depicted the heterocellular cardiac cell interactions, which is extremely important for the maintenance of normal physiology of the cardiac wall in vivo and significantly increased over a period of 21 days in in vitro. This 3D bioprinted "cardiac organoid" model can be adopted to simulate cardiac environments in which cellular crosstalk in diseased pathologies like cardiac atrophy can be studied in vitro and can further be used for drug cytotoxicity screening or underlying disease mechanisms.

miR9 inhibits 6-mer HA-induced cytokine production and apoptosis in human chondrocytes by reducing NF-kB activation

The present study aimed to investigate the expression of miR9 and its correlation with cytokines, proteolytic enzymes and apoptosis in an experimental model of 6-mer HA induced inflammation in human chondrocytes. Human articular chondrocytes, transfected with a miR-9 mimic and miR-9 inhibitor, were stimulated with 6-mer HA in presence/absence of a specific NF-kB inhibitor. 6-mer HA induced a significant increase of TLR-4, CD44, IL-8, IL-18, MMP-9, ADAMTS-5, BAX and BCL-2 mRNAs expression and the related proteins, as well as NF-kB activation, associated with a significant up regulation of miR-9. In chondrocytes transfected with the miR-9 mimic before 6-mer HA treatment we found a decrease of such inflammatory cytokines, metalloproteases and pro-apoptotic molecules, while we found them increased in chondrocytes transfected with the miR9 inhibitor before 6-mer HA stimulation. The activities of TLR-4 and CD44, up regulated by 6-mer HA, were not modified by miR9 mimic/inhibitor, while the NF-kB activation was significantly affected. We suggested that the up regulation of miR9, induced by 6-mer HA, could be a cellular attempt to limit cell damage during inflammation.

A pH-responsiveness injectable hyaluronic acid hydrogel towards regulation of inflammation and remodeling of extracellular matrix for diabetic wound

Diabetes is a universal disease in the world. A critical mediator of proper wound healing is the production, assembly, and remodeling of the ECM by fibroblasts, but in the wound...

EGFR is a pivotal player of the E2/ERβ - mediated functional properties, aggressiveness, and stemness in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is defined by aggressive behavior, limited response to chemotherapy and lower overall survival rates. The increased metastatic potential of TNBC is a combined result of extensive extracellular matrix (ECM) remodeling that leads to cytoskeleton rearrangement and activation of epithelial-to-mesenchymal transition (EMT). The overexpression of epidermal growth factor receptor (EGFR) in TNBC tumors has been linked to induced expression of EMT-related molecules. EMT activation has often been associated with increased metastasis and stemness. Recently, we described the crucial role of EGFR/estrogen receptor beta (ERβ) interplay in the regulation of invasion and cell-matrix interactions. In this study, we report on the EGFR-ERβ functional relationship in connection to the aggressiveness and cancer stem cell (CSC)-like characteristics of TNBC cells. ERβ-suppressed and MDA-MB-231 cells were subjected to downstream EGFR inhibition and/or estradiol stimulation to assess alterations in functional parameters as well as in morphological characteristics, studied by scanning electron, atomic force, and immunofluorescence microscopies. Moreover, the expression and localization of key EMT and CSC-related markers were also evaluated by real-time qPCR, immunofluorescence microscopy, and flow cytometry. EGFR inhibition resulted in an overall suppression of aggressive functional characteristics, which occurred in an ERβ-mediated manner. These changes could be attributed to a reduction, at the molecular level, of EMT and stemness-linked markers, most notably reduced expression of Notch signaling constituents and the cell surface proteoglycan, syndecan-1. Collectively, our study highlights the importance of EGFR signaling as a key effector of aggressiveness, EMT, and stemness in an ERβ-dependent way in TNBC.

Dealing with MDR bacteria and biofilm in the post-antibiotic era: Application of antimicrobial peptides-based nano-formulation

The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.

Deciphering the role of cartilage protein 1 in human dermal fibroblasts: a transcriptomic approach

Cartilage acidic protein 1A (hCRTAC1-A) is an extracellular matrix protein (ECM) of human hard and soft tissue that is associated with matrix disorders. The central role of fibroblasts in tissue integrity and ECM health made primary human dermal fibroblasts (NHDF) the model for the present study, which aimed to provide new insight into the molecular function of hCRTAC1-A. Specifically, we explored the differential expression patterns of specific genes associated with the presence of hCRTAC1-A by RNA-seq and RT-qPCR analysis. Functional enrichment analysis demonstrated, for the very first time, that hCRTAC1-A is involved in extracellular matrix organization and development, through its regulatory effect on asporin, decorin, and complement activity, in cell proliferation, regeneration, wound healing, and collagen degradation. This work provides a better understanding of putative hCRTAC1-A actions in human fibroblasts and a fundamental insight into its function in tissue biology.

Obstruction of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice

BACKGROUND

Delayed wound healing remains a common but challenging problem in patients with acute or chronic wound following accidental scald burn injury. However, the systematic and detailed evaluation of the scald burn injury, including second-degree deep scald (SDDS) and third-degree scald (TDS), is still unclear. The present study aims to analyze the wound-healing speed, the formation of granulation tissue, and the healing quality after cutaneous damage.

METHODS

In order to assess SDDS and TDS, the models of SDDS and TDS were established using a scald instrument in C57BL/6 mice. Furthermore, an excisional wound was administered on the dorsal surface in mice (Cut group). The wound-healing rate was first analyzed at days 0, 3, 5, 7, 15 and 27, with the Cut group as a control. Then, on the full-thickness wounds, hematoxylin and eosin (H&E) staining, Masson staining, Sirius red staining, Victoria blue staining and immunohistochemistry were performed to examine re-epithelialization, the formation of granulation tissue, vascularization, inflammatory infiltration and the healing quality at different time points in the Cut, SDDS and TDS groups.

RESULTS

The presented data revealed that the wound-healing rate was higher in the Cut group, when compared with the SDDS and TDS groups. H&E staining showed that re-epithelialization, formation of granulation tissue and inflammatory infiltration were greater in the Cut group, when compared with the SDDS and TDS groups. Immunohistochemistry revealed that the number of CD31, vascular endothelial growth factor A, transforming growth factor-β and α-smooth muscle actin reached preferential peak in the Cut group, when compared with other groups. In addition, Masson staining, Sirius red staining, Victoria blue staining, Gordon-Sweets staining and stress analysis indicated that the ratio of collagen I to III, reticular fibers, failure stress, Young's modulus and failure length in the SDDS group were similar to those in the normal group, suggesting that healing quality was better in the SDDS group, when compared with the Cut and TDS groups.

CONCLUSION

Overall, the investigators first administered a comprehensive analysis in the Cut, SDDS and TDS groups through in vivo experiments, which further proved that the obstacle of the formation of granulation tissue leads to delayed wound healing after scald burn injury in mice.

Key Matrix Remodeling Enzymes: Functions and Targeting in Cancer

Tissue functionality and integrity demand continuous changes in distribution of major components in the extracellular matrices (ECMs) under normal conditions aiming tissue homeostasis. Major matrix degrading proteolytic enzymes are matrix metalloproteinases (MMPs), plasminogen activators, atypical proteases such as intracellular cathepsins and glycolytic enzymes including heparanase and hyaluronidases. Matrix proteases evoke epithelial-to-mesenchymal transition (EMT) and regulate ECM turnover under normal procedures as well as cancer cell phenotype, motility, invasion, autophagy, angiogenesis and exosome formation through vital signaling cascades. ECM remodeling is also achieved by glycolytic enzymes that are essential for cancer cell survival, proliferation and tumor progression. In this article, the types of major matrix remodeling enzymes, their effects in cancer initiation, propagation and progression as well as their pharmacological targeting and ongoing clinical trials are presented and critically discussed.

Epigenetic Alterations in Triple-Negative Breast Cancer-The Critical Role of Extracellular Matrix

Triple-negative breast cancer (TNBC) is an aggressive subgroup of breast cancer characterized by genomic complexity and therapeutic options limited to only standard chemotherapy. Although it has been suggested that stratifying TNBC patients by pathway-specific molecular alterations may predict benefit from specific therapeutic agents, application in routine clinical practice has not yet been established. There is a growing body of the literature supporting that epigenetic modifications comprised by DNA methylation, chromatin remodeling and non-coding RNAs play a fundamental role in TNBC pathogenesis. Extracellular matrix (ECM) is a highly dynamic 3D network of macromolecules with structural and cellular regulatory roles. Alterations in the expression of ECM components result in uncontrolled matrix remodeling, thus affecting its ability to regulate vital functions of cancer cells, including proliferation, migration, adhesion, invasion and epithelial-to-mesenchymal transition (EMT). Recent molecular data highlight the major role of tumor microenvironment and ECM alterations in TNBC and approaches for targeting tumor microenvironment have recently been recognized as potential therapeutic strategies. Notably, many of the ECM/EMT modifications in cancer are largely driven by epigenetic events, highlighting the pleiotropic effects of the epigenetic network in TNBC. This article presents and critically discusses the current knowledge on the epigenetic alterations correlated with TNBC pathogenesis, with emphasis on those associated with ECM/EMT modifications, their prognostic and predictive value and their use as therapeutic targets.

In Silico Identification of Contradictory Role of ADAMTS5 in Hepatocellular Carcinoma

Background:

ADAMTS5 has different roles in multiple types of cancers and participates in various molecular mechanisms. However, the prognostic value of ADAMTS5 in patients with hepatocellular carcinoma (HCC) still remains unclear. We carried the study to evaluate the prognostic value and identified underlying molecular mechanisms in HCC.

Methods:

Firstly, the association of ADAMTS5 expression and clinicopathological parameters was evaluated by in GSE14520. Next, ADAMTS5 expression in HCC was performed using GSE14520, GSE36376, GSE76427 and The Cancer Genome Atlas (TCGA) profile. Furthermore, Kaplan-Meier analysis, Univariate and Multivariate Cox regression analysis, subgroup analysis was performed to evaluate the prognostic value of ADAMTS5 in HCC. Finally, GO enrichment analysis, gene set enrichment analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) were performed to revealed underlying molecular mechanisms.

Result:

The expression of ADAMTS5 was positively correlated with the development of HCC. Next, high ADAMTS5 expression was significantly associated with poorer survival (all P < 0.05) and the impact of ADAMTS5 on all overall survival (OS), disease-free survival (DFS), relapse-free survival (RFS), disease specific survival (DSS) and progression free interval (PFI) was specific for HCC among other 29 cancer types. Subgroup analysis showed that ADAMTS5 overexpression was significantly associated with poorer OS in patients with HCC. Finally, ADAMTS5 might participate in the status conversion from metabolic-dominant to extracellular matrix-dominant, and the activation of ECM-related biological process might contribute to high higher mortality risk for patients with HCC.

Conclusion:

ADAMTS5 may play an important role in the progression of HCC, and may be considered as a novel and effective biomarker for predicting prognosis for patients with HCC.

MicroRNA-489-3p Represses Hepatic Stellate Cells Activation by Negatively Regulating the JAG1/Notch3 Signaling Pathway

BACKGROUND

The transformation of hepatic stellate cells (HSCs) into collagen-producing myofibroblasts is a key event in hepatic fibrogenesis. Recent studies have shown that microRNAs (miRNAs) play a critical role in the transformation of HSCs. However, the function of miR-489-3p in liver fibrosis remains unclear.

METHODS

Here, we detected the levels of miR-489-3p and jagged canonical Notch ligand 1 (JAG1) in liver fibrosis by using CCl4-treated rats as an in vivo model and transforming growth factor-beta 1 (TGF-β1)-treated HSC cell lines LX-2 and HSC-T6 as in vitro models. The expression of profibrotic markers was affected by transfecting LX-2 cells with either miR-489-3p mimic or si-JAG1. A dual-luciferase reporter assay was carried out to study the interaction of JAG1 with miR-489-3p.

RESULTS

We found that miR-489-3p was remarkably decreased while JAG1 was increased in liver fibrosis models both in vivo and in vitro. Overexpression of miR-489-3p reduced the expression of profibrotic markers and the activation of LX-2 cells induced by TGF-β1. Moreover, miR-489-3p decreased the expression of jagged canonical Notch ligand 1 (JAG1) in LX-2 cells by interacting with its 3'-UTR. As JAG1 is a Notch ligand, decreased JAG1 by miR-489-3p inhibited the Notch signaling pathway. Moreover, the downregulation of JAG1 inhibited the expression of fibrotic markers.

CONCLUSION

Our results indicate that miR-489-3p can inhibit HSC activation by inhibiting the JAG1/Notch3 signaling pathway.

MicroRNA-184 negatively regulates corneal epithelial wound healing via targeting CDC25A, CARM1, and LASP1

Background

MicroRNAs (miRNAs) play critical roles in corneal development and functional homeostasis. Our previous study identified miR-184 as one of the most highly expressed miRNAs in the corneal epithelium. Even though its expression level plummeted dramatically during corneal epithelial wound healing (CEWH), its precise role in mediating corneal epithelial renewal was unresolved. The present study aimed to reveal the function and mechanism of miR-184 in regulating CEWH.

Methods

Quantitative RT-PCR analysis characterized the miR-184 expression pattern during CEWH in mice. Ectopic miR-184 injection determined its effect on this process in vivo. We evaluated the effects of miR-184 and its target genes on the proliferation, cell cycle, and migration of human corneal epithelial cells (HCECs) using MTS, flow cytometry, and wound-healing assay, respectively. Bioinformatic analysis, in conjunction with gene microarray analysis and cell-based luciferase assays, pinpointed gene targets of miR-184 contributing to CEWH.

Results

MiR-184 underwent marked downregulation during mouse CEWH. Ectopic miR-184 overexpression delayed this process in mice. Furthermore, miR-184 transfection into HCECs significantly inhibited cell proliferation, cell cycle progression, and cell migration. MiR-184 directly targeted CDC25A, CARM1, and LASP1, and downregulated their expression in HCECs. CARM1 downregulation inhibited both HCEC proliferation and migration, whereas a decrease in LASP1 gene expression only inhibited migration.

Conclusions

Our results demonstrate that miR-184 inhibits corneal epithelial cell proliferation and migration via targeting CDC25A, CARM1, and LASP1, suggesting it acts as a negative modulator during CEWH. Therefore, identifying strategies to suppress miR-184 expression levels has the potential to promote CEWH.

Extracellular matrix: key structural and functional meshwork in health and disease

The extracellular matrix (ECM) is a multifunctional 3D network of interconnected macromolecules that mediate cellular responses in normal and pathological conditions, including wound healing, tissue homeostasis, skeletal and cardiovascular disease, cancer and drug resistance. The potential of targeting ECM components, such as proteoglycans and glycosaminoglycans, matrix-degrading enzymes and miRNAs will serve as a novel tool for innovative diagnostic methods and therapeutic strategies. With this Special Issue on Extracellular Matrix in Health and Disease, The FEBS Journal offers an updated overview of the functional properties and biological roles of several ECM components, highlighting the significance of ECM targeting in disease management.

Complexity of matrix phenotypes

The extracellular matrix is engaged in an ever-evolving and elegant ballet of dynamic reciprocity that directly and bi-directionally regulates cell behavior. Homeostatic and pathophysiological changes in cell-matrix signaling cascades manifest as complex matrix phenotypes. Indeed, the extracellular matrix can be implicated in virtually every known human disease, thus, making it the most critical and dynamic "organ" in the human body. The overall goal of this Special Issue is to provide an accurate and inclusive functional definition that addresses the inherent complexity of matrix phenotypes. This goal is summarily achieved via a corpus of expertly written articles, reviews and original research, focused at answering this question empirically and fundamentally via state-of-the-art methods and research strategies.

miR-200b restrains EMT and aggressiveness and regulates matrix composition depending on ER status and signaling in mammary cancer

Secreted microRNAs (miRNAs) reside in a complex regulatory network with extracellular matrix (ECM) macromolecules, which affect cell-cell communication, therefore miRNA expression highlights its significance in several aspects of human diseases, including cancer. miRNA-mediated regulation of breast cancer has received considerable attention due to evidence that shows miRNAs to mediate estrogen receptor (ER) status, metastasis, chemoresistance and epithelial-to-mesenchymal transition (EMT). miR-200b is a pluripotent miRNA, which is inversely regulated by ERα and ERβ in mammary cancer. It has been identified as tumor suppressor and EMT inhibitor serving as a critical biomarker, as its expression in breast tumor determines the disease-free survival, thus highlighting its roles in breast cancer invasion and metastasis. The main goal of this study was to investigate the role of miR-200b in modulating the behavior of breast cancer cells with different ER status. We demonstrate that estrogen signaling through ERs reduces miR-200b expression levels in ERα-positive breast cancer cells. Moreover, miR-200b upregulation reduces the aggressive phenotype of ERβ-positive breast cancer cells by inhibiting cell invasiveness and motility, followed by ECM reorganization as well as cytoskeletal and morphological changes concluded from deep inspection of cell topography. Future investigation towards the mechanistic perspective of miR-200b effects in the behavior of aggressive mammary cancer cells appears rewarding in order to expand our understanding of miR-200b as a novel mediator beyond breast cancer diagnosis and pharmaceutical targeting.

Towards extracellular matrix normalization for improved treatment of solid tumors

It is currently challenging to eradicate cancer. In the case of solid tumors, the dense and aberrant extracellular matrix (ECM) is a major contributor to the heterogeneous distribution of small molecule drugs and nano-formulations, which makes certain areas of the tumor difficult to treat. As such, much research is devoted to characterizing this matrix and devising strategies to modify its properties as a means to facilitate the improved penetration of drugs and their nano-formulations. This contribution presents the current state of knowledge on the composition of normal ECM and changes to ECM that occur during the pathological progression of cancer. It also includes discussion of strategies designed to modify the composition/properties of the ECM as a means to enhance the penetration and transport of drugs and nano-formulations within solid tumors. Moreover, a discussion of approaches to image the ECM, as well as ways to monitor changes in the ECM as a function of time are presented, as these are important for the implementation of ECM-modifying strategies within therapeutic interventions. Overall, considering the complexity of the ECM, its variability within different tissues, and the multiple pathways by which homeostasis is maintained (both in normal and malignant tissues), the available literature - while promising - suggests that improved monitoring of ECM remodeling in vivo is needed to harness the described strategies to their full potential, and match them with an appropriate chemotherapy regimen.

Leucine-activated nanohybrid biofilm for skin regeneration via improving cell affinity and neovascularization capacity

Nanohybrids containing amino acid are doped into biodegradable nanofibrous membranes, which improves the cell affinity, the migration and growth of fibroblasts, and the neovascularization capacity, comprehensively accelerating a rapid wound healing.

Insights into myofibroblasts and their activation in scleroderma: opportunities for therapy?

PURPOSE OF REVIEW

The persistence of myofibroblasts is a key feature of fibrosis and in fibrotic diseases including scleroderma. This review evaluates the emerging concepts of the origins and cell populations that contribute to myofibroblasts and the molecular mechanisms that govern phenotypic conversion and that highlight opportunities for new interventional treatments in scleroderma.

RECENT FINDINGS

Studies have defined heterogeneity in fibroblast-like cells that can develop into myofibroblast in normal wound healing, scarring and fibrosis. Characterizing these distinct cell populations and their behaviour has been a key focus. In addition, the overarching impact of epigenetic regulation of genes associated with inflammatory responses, cell signalling and cell communication and the extracellular matrix (ECM) has provided important insights into the formation of myofibroblast and their function. Important new studies include investigations into the relationship between inflammation and myofibroblast production and further evidence has been gathered that reveal the importance of ECM microenvironment, biomechanical sensing and mechanotransduction.

SUMMARY

This review highlights our current understanding and outlines the increasing complexity of the biological processes that leads to the appearance of the myofibroblast in normal functions and in diseased tissues. We also focus on areas of special interest in particular, studies that have therapeutic potential in fibrosis and scleroderma.

Characterizing the dynamic rheology in the pericellular region by human mesenchymal stem cell re-engineering in PEG-peptide hydrogel scaffolds

During wound healing, human mesenchymal stem cells (hMSCs) migrate to injuries to regulate inflammation and coordinate tissue regeneration. To enable migration, hMSCs re-engineer the extracellular matrix rheology. Our work determines the correlation between cell engineered rheology and motility. We encapsulate hMSCs in a cell-degradable peptide-polymeric hydrogel and characterize the change in rheological properties in the pericellular region using multiple particle tracking microrheology. Previous studies determined that pericellular rheology is correlated with motility. Additionally, hMSCs re-engineer their microenvironment by regulating cell-secreted enzyme, matrix metallopro-teinases (MMPs), activity by also secreting their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). We independently inhibit TIMPs and measure two different degradation profiles, reaction-diffusion and reverse reaction-diffusion. These profiles are correlated with cell spreading, speed and motility type. We model scaffold degradation using Michaelis-Menten kinetics, finding a decrease in kinetics between joint and independent TIMP inhibition. hMSCs ability to regulate microenvironmental remodeling and motility could be exploited in design of new materials that deliver hMSCs to wounds to enhance healing.

The extracellular matrix as a multitasking player in disease

Extracellular matrices (ECMs) are highly specialized and dynamic three-dimensional (3D) scaffolds into which cells reside in tissues. ECM is composed of a variety of fibrillar components, such as collagens, fibronectin, and elastin, and non-fibrillar molecules as proteoglycans, hyaluronan, and glycoproteins including matricellular proteins. These macromolecular components are interconnected forming complex networks that actively communicate with cells through binding to cell surface receptors and/or matrix effectors. ECMs exert diverse roles, either providing tissues with structural integrity and mechanical properties essential for tissue functions or regulating cell phenotype and functions to maintain tissue homeostasis. ECM molecular composition and structure vary among tissues, and is markedly modified during normal tissue repair as well as during the progression of various diseases. Actually, abnormal ECM remodeling occurring in pathologic circumstances drives disease progression by regulating cell-matrix interactions. The importance of matrix molecules to normal tissue functions is also highlighted by mutations in matrix genes that give rise to genetic disorders with diverse clinical phenotypes. In this review, we present critical and emerging issues related to matrix assembly in tissues and the multitasking roles for ECM in diseases such as osteoarthritis, fibrosis, cancer, and genetic diseases. The mechanisms underlying the various matrix-based diseases are also discussed. Research focused on the highly dynamic 3D ECM networks will help to discover matrix-related causative abnormalities of diseases as well as novel diagnostic tools and therapeutic targets.

Hyaluronan: molecular size-dependent signaling and biological functions in inflammation and cancer

Hyaluronan (HA) is a linear nonsulfated glycosaminoglycan of the extracellular matrix that plays a pivotal role in a variety of biological processes. High-molecular weight HA exhibits different biological properties than oligomers and low-molecular weight HA. Depending on their molecular size, HA fragments can influence cellular behavior in a different mode of action. This phenomenon is attributed to the different manner of interaction with the HA receptors, especially CD44 and RHAMM. Both receptors can trigger signaling cascades that regulate cell functional properties, such as proliferation migration, angiogenesis, and wound healing. HA fragments are able to enhance or attenuate the HA receptor-mediated signaling pathways, as they compete with the endogenous HA for binding to the receptors. The modulation of these pathways could be crucial for the development of pathological conditions, such as inflammation and cancer. The primary goal of this review is to critically present the importance of HA molecular size on cellular signaling, functional cell properties, and morphology in normal and pathological conditions, including inflammation and cancer. A deeper understanding of these mechanisms could contribute to the development of novel therapeutic strategies.

Matrix modeling and remodeling: A biological interplay regulating tissue homeostasis and diseases

The overall structure and architecture of the extracellular matrix undergo dramatic alterations in composition, form, and functionality over time. The stochasticity begins during development, essential for maintaining organismal homeostasis and is heavily implicated in many pathobiological states including fibrosis and cancer. Modeling and remodeling of the matrix is driven by the local cellular milieu and secreted and cell-associated components in a framework of dynamic reciprocity. This collection of expertly-written reviews aims to relay state-of-the-art information concerning the mechanisms of matrix modeling and remodeling in physiological development and disease.

Advances in targeting epidermal growth factor receptor signaling pathway in mammary cancer

Breast cancer is the most common malignancy among women worldwide. The role of epidermal growth factor receptor (EGFR) in many epithelial malignancies has been established, since it is dysregulated, overexpressed or mutated. Its overexpression has been associated with increased aggressiveness and metastatic potential in breast cancer. The well-established interplay between EGFR signaling pathway and estrogen receptors (ERs) as well as major extracellular matrix (ECM) mediators is crucial for regulating basic functional properties of breast cancer cells, including migration, proliferation, adhesion and invasion. EGFR activation leads to endocytosis of the receptor with implications in the regulation of downstream signaling effectors, the modulation of autophagy and cell survival. Therefore, EGFR is considered as a promising therapeutic target in breast cancer. Several anti-EGFR therapies (i.e. monoclonal antibodies and tyrosine kinase inhibitors) have been evaluated both in vitro and in vivo, making their way to clinical trials. However, the response rates of anti-EGFR therapies in the clinical trials is low mainly due to chemoresistance. Novel drug design, phytochemicals and microRNAs (miRNAs) are assessed as new therapeutic approaches against EGFR. The main goal of this review is to highlight the importance of targeting EGFR signaling pathway in terms of its crosstalk with ERs, the involvement of ECM effectors and epigenetics. Moreover, recent insights into the design of specialized delivery systems contributing in the development of novel diagnostic and therapeutic approaches in breast cancer are addressed.