Proteinases involved in matrix turnover during cartilage and bone breakdown

Investigating and Annotating the Human Peptidome Profile from Urine under Normal Physiological Conditions

Examining the composition of the typical urinary peptidome and identifying the enzymes responsible for its formation holds significant importance, as it mirrors the normal physiological state of the human body. Any deviation from this normal profile could serve as an indicator of pathological processes occurring in vivo. Consequently, this study focuses on characterizing the normal urinary peptidome and investigating the various catalytic enzymes that are involved in generating these native peptides in urine. Our findings reveal that 1503 endogenous peptides, corresponding to 436 precursor proteins, were consistently identified robustly in at least 10 samples out of a total of 19 samples. Notably, the liver and kidneys exhibited the highest number of tissue-enriched or enhanced genes in the analyzed urinary peptidome. Furthermore, among the catalytic types, CTSD (cathepsin D) and MMP2 (matrix metalloproteinase-2) emerged as the most prominent peptidases in the aspartic and metallopeptidases categories, respectively. A comparison of our dataset with two of the most comprehensive urine peptidome datasets to date indicates a consistent relative abundance of core endogenous peptides for different proteins across all three datasets. These findings can serve as a foundational reference for the discovery of biomarkers in various human diseases.

Link Protein 1 Is Involved in the Activity-Dependent Modulation of Perineuronal Nets in the Spinal Cord

One of the challenges of the mature nervous system is to maintain the stability of neural networks while providing a degree of plasticity to generate experience-dependent modifications. This plasticity-stability dynamism is regulated by perineuronal nets (PNNs) and is crucial for the proper functioning of the system. Previously, we found a relation between spinal PNNs reduction and maladaptive plasticity after spinal cord injury (SCI), which was attenuated by maintaining PNNs with activity-dependent therapies. Moreover, transgenic mice lacking the cartilage link protein 1 (Crtl1 KO mice) showed aberrant spinal PNNs and increased spinal plasticity. Therefore, the aim of this study is to evaluate the role of link protein 1 in the activity-dependent modulation of spinal PNNs surrounding motoneurons and its impact on the maladaptive plasticity observed following SCI. We first studied the activity-dependent modulation of spinal PNNs using a voluntary wheel-running protocol. This training protocol increased spinal PNNs in WT mice but did not modify PNN components in Crtl1 KO mice, suggesting that link protein 1 mediates the activity-dependent modulation of PNNs. Secondly, a thoracic SCI was performed, and functional outcomes were evaluated for 35 days. Interestingly, hyperreflexia and hyperalgesia found at the end of the experiment in WT-injured mice were already present at basal levels in Crtl1 KO mice and remained unchanged after the injury. These findings demonstrated that link protein 1 plays a dual role in the correct formation and in activity-dependent modulation of PNNs, turning it into an essential element for the proper function of PNN in spinal circuits.

Sivelestat ameliorates sepsis-induced myocardial dysfunction by activating the PI3K/AKT/mTOR signaling pathway

The cardioprotective role of sivelestat, a neutrophil elastase inhibitor, has already been demonstrated, but the underlying molecular mechanism remains unclear. This study aimed to explore the mechanism underlying the role of sivelestat in sepsis-induced myocardial dysfunction (SIMD). We found that sivelestat treatment remarkably improved the viability and suppressed the apoptosis of lipopolysaccharide (LPS)-stimulated H9c2 cells. In vivo, sivelestat treatment was associated with an improved survival rate; reduced serum cTnT, TNF-α, IL-1β levels and myocardial TNF-α and IL-1β levels; ameliorated cardiac function and structure; and reduced cardiomyocyte apoptosis. Moreover, sivelestat treatment substantially increased Bcl-2 expression and suppressed caspase-3 and Bax expression in LPS-induced H9c2 cells and in the heart tissues of septic rats. Furthermore, the phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) signaling pathway was activated both in vitro and in vivo. The protective effect of sivelestat against SIMD was reversed by the PI3K inhibitor LY294002. In summary, sivelestat can protect against SIMD by activating the PI3K/AKT/mTOR signaling pathway.

Extracellular Matrix Cues Regulate Mechanosensing and Mechanotransduction of Cancer Cells

Extracellular biophysical properties have particular implications for a wide spectrum of cellular behaviors and functions, including growth, motility, differentiation, apoptosis, gene expression, cell-matrix and cell-cell adhesion, and signal transduction including mechanotransduction. Cells not only react to unambiguously mechanical cues from the extracellular matrix (ECM), but can occasionally manipulate the mechanical features of the matrix in parallel with biological characteristics, thus interfering with downstream matrix-based cues in both physiological and pathological processes. Bidirectional interactions between cells and (bio)materials in vitro can alter cell phenotype and mechanotransduction, as well as ECM structure, intentionally or unintentionally. Interactions between cell and matrix mechanics in vivo are of particular importance in a variety of diseases, including primarily cancer. Stiffness values between normal and cancerous tissue can range between 500 Pa (soft) and 48 kPa (stiff), respectively. Even the shear flow can increase from 0.1-1 dyn/cm2 (normal tissue) to 1-10 dyn/cm2 (cancerous tissue). There are currently many new areas of activity in tumor research on various biological length scales, which are highlighted in this review. Moreover, the complexity of interactions between ECM and cancer cells is reduced to common features of different tumors and the characteristics are highlighted to identify the main pathways of interaction. This all contributes to the standardization of mechanotransduction models and approaches, which, ultimately, increases the understanding of the complex interaction. Finally, both the in vitro and in vivo effects of this mechanics-biology pairing have key insights and implications for clinical practice in tumor treatment and, consequently, clinical translation.

GPR56 signaling pathway network and its dynamics in the mesenchymal transition of glioblastoma

G protein-coupled receptor 56 (GPR56/ADGRG1) is a multifunctional adhesion GPCR involved in diverse biological processes ranging from development to cancer. In our earlier study, we reported that GPR56 is expressed heterogeneously in glioblastoma (GBM) and is involved in the mesenchymal transition, making it a promising therapeutic target (Ganesh et al., 2022). Despite its important role in cancer, its mechanism of action or signaling is not completely understood. Thus, based on transcriptomic, proteomic, and phosphoproteomic differential expression data of GPR56 knockdown U373-GBM cells included in our above study along with detailed literature mining of the molecular events plausibly associated with GPR56 activity, we have constructed a signaling pathway map of GPR56 as may be applicable in mesenchymal transition in GBM. The map incorporates more than 100 molecular entities including kinases, receptors, ion channels, and others associated with Wnt, integrin, calcium signaling, growth factors, and inflammation signaling pathways. We also considered intracellular and extracellular factors that may influence the activity of the pathway entities. Here we present a curated signaling map of GPR56 in the context of GBM and discuss the relevance and plausible cross-connectivity across different axes attributable to GPR56 function. GPR56 signaling and mesenchymal transition.

Basement membrane dynamics and mechanics in tissue morphogenesis

The basement membrane (BM) is a thin, planar-organized extracellular matrix that underlies epithelia and surrounds most organs. During development, the BM is highly dynamic and simultaneously provides mechanical properties that stabilize tissue structure and shape organs. Moreover, it is important for cell polarity, cell migration, and cell signaling. Thereby BM diverges regarding molecular composition, structure, and modes of assembly. Different BM organization leads to various physical features. The mechanisms that regulate BM composition and structure and how this affects mechanical properties are not fully understood. Recent studies show that precise control of BM deposition or degradation can result in BMs with locally different protein densities, compositions, thicknesses, or polarization. Such heterogeneous matrices can induce temporospatial force anisotropy and enable tissue sculpting. In this Review, I address recent findings that provide new perspectives on the role of the BM in morphogenesis.

Identification and characterization of aptameric inhibitors of human neutrophil elastase

Human neutrophil elastase (HNE) plays a pivotal role in innate immunity, inflammation, and tissue remodeling. Aberrant proteolytic activity of HNE contributes to organ destruction in various chronic inflammatory diseases including emphysema, asthma, and cystic fibrosis. Therefore, elastase inhibitors could alleviate the progression of these disorders. Here, we used the systematic evolution of ligands by exponential enrichment to develop ssDNA aptamers that specifically target HNE. We determined the specificity of the designed inhibitors and their inhibitory efficacy against HNE using biochemical and in vitro methods, including an assay of neutrophil activity. Our aptamers inhibit the elastinolytic activity of HNE with nanomolar potency and are highly specific for HNE and do not target other tested human proteases. As such, this study provides lead compounds suitable for the evaluation of their tissue-protective potential in animal models.

Berberine regulates bone metabolism in apical periodontitis by remodelling the extracellular matrix

OBJECTIVES

The objectives of this study were to explore the role and related mechanism of berberine in repairing bone destruction in apical periodontics (AP).

MATERIALS AND METHODS

AP was established in 14 of 21 male Wistar rats (four weeks of age; 70-80 g) for 3 weeks. The canals were cleaned and administered berberine (2 mg/ml; n = 7) or calcium hydroxide (100 mg/ml; control; n = 7), followed by glass ionomer cement sealing. After 3 weeks, specimen collection followed by micro-computed tomography (μ-CT) and histological staining was performed, including haematoxylin and eosin staining, Masson's trichrome staining, tartrate-resistant acid phosphatase staining, immunohistochemistry and immunofluorescence histochemistry.

RESULTS

μ-CT showed that AP lesion volume reduced in the berberine group. Histopathology showed that berberine decreased the activity and number of osteoclasts but increased the expression of proteins related to osteoblast differentiation, including alkaline phosphatase and osterix. The immune cell, T cell, dendritic cell and macrophage counts were significantly decreased in the berberine group. In the berberine group, the expression of extracellular matrix-degraded proteases, metalloproteinases, was decreased; however, that of extracellular matrix-stable proteases, lysyl oxidases, was increased.

CONCLUSIONS

Berberine controlled the inflammatory response and regulated bone metabolism in AP by reducing metalloproteinase expression and increasing lysyl oxidases expression.

Static and Dynamic: Evolving Biomaterial Mechanical Properties to Control Cellular Mechanotransduction

The extracellular matrix (ECM) is a highly dynamic system that constantly offers physical, biological, and chemical signals to embraced cells. Increasing evidence suggests that mechanical signals derived from the dynamic cellular microenvironment are essential controllers of cell behaviors. Conventional cell culture biomaterials, with static mechanical properties such as chemistry, topography, and stiffness, have offered a fundamental understanding of various vital biochemical and biophysical processes, such as cell adhesion, spreading, migration, growth, and differentiation. At present, novel biomaterials that can spatiotemporally impart biophysical cues to manipulate cell fate are emerging. The dynamic properties and adaptive traits of new materials endow them with the ability to adapt to cell requirements and enhance cell functions. In this review, an introductory overview of the key players essential to mechanobiology is provided. A biophysical perspective on the state-of-the-art manipulation techniques and novel materials in designing static and dynamic ECM-mimicking biomaterials is taken. In particular, different static and dynamic mechanical cues in regulating cellular mechanosensing and functions are compared. This review to benefit the development of engineering biomechanical systems regulating cell functions is expected.

A Biocompatible Probe for the Detection of Neutrophil Elastase Free from the Interference of Structural Changes and Its Application to Ratiometric Photoacoustic Imaging In Vivo

Neutrophil elastase (NE) plays a key role in chronic inflammation and acute responses to infection and injury. Effective disease interventions thus call for precise identification of NE to aid the clinical treatment of such diseases. However, the detection process suffers from the interference of structural changes of NE. Herein, we introduce a molecular probe with high biocompatibility to overcome the interference, which was achieved by combining theoretical calculations and experimental studies, that permits highly specific and sensitive detection of NE in cells and in vivo. The upregulated NE accumulation was specifically measured in inflammation by ratiometric photoacoustic and near-infrared fluorescence imaging, providing a new method for developing more specific fluorogenic probes for other enzymes.

Standardised Sonneratia apetala Buch.-Ham. fruit extract inhibits human neutrophil elastase and attenuates elastase-induced lung injury in mice

Chronic obstructive pulmonary disease (COPD) along with asthma is a major and increasing global health problem. Smoking contributes to about 80%-90% of total COPD cases in the world. COPD leads to the narrowing of small airways and destruction of lung tissue leading to emphysema primarily caused by neutrophil elastase. Neutrophil elastase plays an important role in disease progression in COPD patients and has emerged as an important target for drug discovery. Sonneratia apetala Buch.-Ham. is a mangrove plant belonging to family Sonneratiaceae. It is widely found in the Sundarban regions of India. While the fruits of this plant have antibacterial, antifungal, antioxidant and astringent activities, fruit and leaf extracts have been shown to reduce the symptoms of asthma and cough. The aim of this study is to find whether hydro alcoholic fruit extracts of S. apetala inhibit neutrophil elastase and thus prevent the progression of neutrophil elastase-driven lung emphysema. The hydroalcoholic extract, ethanol: water (90:10), of the S. apetala Buch.-Ham. fresh fruits (SAM) were used for neutrophil elastase enzyme kinetic assay and IC₅₀ of the extract was determined. The novel HPLC method has been developed and the extract was standardized with gallic acid and ellagic acid as standards. The extract was further subjected to LC-MS² profiling to identify key phytochemicals. The standardized SAM extract contains 53 μg/mg of gallic acid and 95 μg/mg of ellagic acid, based on the HPLC calibration curve. SAM also reversed the elastase-induced morphological change of human epithelial cells and prevented the release of ICAM-1 in vitro and an MTT assay was conducted to assess the viability. Further, 10 mg/kg SAM had reduced alveolar collapse induced by neutrophil elastase in the mice model. Thus, in this study, we reported for the first time that S. apetala fruit extract has the potential to inhibit human neutrophil elastase in vitro and in vivo.

Biochemical and biophysical analysis of the interaction of a recombinant form of Staphylococcus aureus enolase with plasminogen

Aim: Pathogenic invasion of Staphylococcus aureus is critically dependent on host plasminogen activation. Materials & methods: The pathophysiological implications of the interactions between S. aureus recombinant enolase and host plasminogen were investigated. The effects of mutation and small synthetic peptide inhibitors on interactions were assessed. Results: In vitro, the S. aureus recombinant enolase exists as a catalytically active fragile octamer and a robust dimer. The dimer interacts with the host plasminogen on the S. aureus surface. Conclusion: The interaction of host plasminogen and S. aureus enolase might mediate bacterial adherence to the host, activate the plasminogen with the help of plasminogen activators and prevent α2-antiplasmin-mediated inhibition of plasmin. Incorporating mutant and synthetic peptides inhibited the interactions and their associated pathophysiological consequences.

Novel benzoxazinone derivative as potent human neutrophil elastase inhibitor: Potential implications in lung injury

Neutrophil elastase, a powerful physiological defence tool, may serve as drug target for diverse diseases due to its bystander effect on host cells like chronic obstructive pulmonary disease (COPD). Here, we synthesised seven novel benzoxazinone derivatives and identified that these synthetic compounds are human neutrophil elastase inhibitor that was demonstrated by enzyme substrate kinetic assay. One such compound, PD05, emerged as the most potent inhibitor with lower IC₅₀ as compared to control drug sivelestat. While this inhibition is competitive based on substrate dilution assay, PD05 showed a high binding affinity for human neutrophil elastase (Kd = 1.63 nM) with faster association and dissociation rate compared to notable elastase inhibitors like ONO 6818 and AZD9668, and its interaction with human neutrophil elastase was fully reversible.Preclinical pharmacokinetic studies were performed in vitro where protein binding was found to be 72% with a high recovery rate, aqueous solubility of 194.7 μM, low permeability along with a favourable hERG. Experiments with cell line revealed that the molecule successfully prevented elastase induced rounding and retracted cell morphology and cell cytotoxicity. In mouse model PD05 is able to reduce the alveolar collapse induced by neutrophil elastase. In summary, we demonstrate the in situ, in vitro and in vivo anti-elastase potential of the newly synthesised benzoxazinone derivative PD05 and thus this could be promising candidate for further investigation as a drug for the treatment of COPD.

The Role and Modulation of Spinal Perineuronal Nets in the Healthy and Injured Spinal Cord

Rather than being a stable scaffold, perineuronal nets (PNNs) are a dynamic and specialized extracellular matrix involved in plasticity modulation. They have been extensively studied in the brain and associated with neuroprotection, ionic buffering, and neural maturation. However, their biological function in the spinal cord and the effects of disrupting spinal PNNs remain elusive. The goal of this review is to summarize the current knowledge of spinal PNNs and their potential in pathological conditions such as traumatic spinal cord injury (SCI). We also highlighted interventions that have been used to modulate the extracellular matrix after SCI, targeting the glial scar and spinal PNNs, in an effort to promote regeneration and stabilization of the spinal circuits, respectively. These concepts are discussed in the framework of developmental and neuroplastic changes in PNNs, drawing similarities between immature and denervated neurons after an SCI, which may provide a useful context for future SCI research.

Fibroblasts orchestrate cellular crosstalk in the heart through the ECM

Cell communication is needed for organ function and stress responses, especially in the heart. Cardiac fibroblasts, cardiomyocytes, immune cells, and endothelial cells comprise the major cell types in ventricular myocardium that together coordinate all functional processes. Critical to this cellular network is the non-cellular extracellular matrix (ECM) that provides structure and harbors growth factors and other signaling proteins that affect cell behavior. The ECM is not only produced and modified by cells within the myocardium, largely cardiac fibroblasts, it also acts as an avenue for communication among all myocardial cells. In this Review, we discuss how the development of therapeutics to combat cardiac diseases, specifically fibrosis, relies on a deeper understanding of how the cardiac ECM is intertwined with signaling processes that underlie cellular activation and behavior.

Into the Tissues: Extracellular Matrix and Its Artificial Substitutes: Cell Signalling Mechanisms

The existence of orderly structures, such as tissues and organs is made possible by cell adhesion, i.e., the process by which cells attach to neighbouring cells and a supporting substance in the form of the extracellular matrix. The extracellular matrix is a three-dimensional structure composed of collagens, elastin, and various proteoglycans and glycoproteins. It is a storehouse for multiple signalling factors. Cells are informed of their correct connection to the matrix via receptors. Tissue disruption often prevents the natural reconstitution of the matrix. The use of appropriate implants is then required. This review is a compilation of crucial information on the structural and functional features of the extracellular matrix and the complex mechanisms of cell-cell connectivity. The possibilities of regenerating damaged tissues using an artificial matrix substitute are described, detailing the host response to the implant. An important issue is the surface properties of such an implant and the possibilities of their modification.

Methoxy-Monobenzoylmethane Protects Skin from UV-Induced Damages in a Randomized, Placebo Controlled, Double-Blinded Human In Vivo Study and Prevents Signs of Inflammation While Improving the Skin Barrier

INTRODUCTION

Sun protection is important in skin care and requires special attention as inefficient protection might trigger skin pathologies including polymorphic light eruption (PLE). The reduce-improve-protect (RIP) concept to avoid the onset of ultraviolet (UV) irradiation-induced diseases or damage to human skin is important. Methoxy-monobenzoylmethane (MeO-MBM), which is neither a UVB nor a UVA filter, converts to the UV filter avobenzone under UV irradiation and further acts as a photoantioxidant during its conversion process and initially as an antioxidant material. The aim of this study was to understand the mechanisms by which MeO-MBM improves the condition of UV-stressed skin through its photoantioxidant properties. The improvement of the skin condition by the activity of MeO-MBM as active ingredient was also investigated.

METHODS

Potential molecular targets were identified by in silico docking to numerous cellular membrane receptors on the cell surface or nuclear membrane, followed by microarray analysis of 164 genes after MeO-MBM treatment of normal human epidermal keratinocytes (NHEK). We conducted randomized, double-blinded, intra-individual comparison vs. placebo studies on ten volunteers, aged between 34 and 65 years, to assess the effect of MeO-MBM in vivo. The effect after UV-induced inflammation was assessed in a protective and curative set-up with 2% MeO-MBM vs. 1% hydrocortisone and placebo based on the change in blood flow. The barrier function of the skin was assessed by the change in transepidermal water loss (TEWL), skin scaling and skin thickness after the treatment with MeO-MBM. Additionally, the effect of MeO-MBM after UV-induced stress on the activation of ferritin in human explants was determined ex vivo.

RESULTS

A docking simulation of MeO-MBM showed a potential interaction with the retinoic acid receptor gamma and further revealed downregulation of proteins related to inflammation. In the protective treatment set-up, after 24 h MeO-MBM significantly reduced the delta blood flow compared to placebo, while this reduction was more prominent with hydrocortisone. In the curative treatment set-up, a greater reduction in delta blood flow was also observed with MeO-MBM compared to placebo and similar to hydrocortisone. Treatment with MeO-MBM revealed an improvement in skin barrier function as a result of decreased TEWL, reduced skin scaling and increased skin thickness. Immunohistochemistry staining of ferritin on human skin explants further showed that the treatment with MeO-MBM reduced the ferritin expression.

CONCLUSION

Based on these results, MeO-MBM is capable of exerting an anti-aging activity via the retinoic acid receptor gamma. Its anti-inflammatory and anti-oxidative activity manifested via the downregulation of multiple anti-inflammatory genes as well as the reduction of ferritin in skin tissue. This study shows that the multidimensional functionality of MeO-MBM offers an effective approach to combat acute and chronic deleterious effects of oxidative UV damage while simultaneously enhancing the skin barrier function.

Blood-Spinal Cord Barrier: Its Role in Spinal Disorders and Emerging Therapeutic Strategies

The blood-spinal cord barrier (BSCB) has been long thought of as a functional equivalent to the blood-brain barrier (BBB), restricting blood flow into the spinal cord. The spinal cord is supported by various disc tissues that provide agility and has different local immune responses compared to the brain. Though physiologically, structural components of the BSCB and BBB share many similarities, the clinical landscape significantly differs. Thus, it is crucial to understand the composition of BSCB and also to establish the cause–effect relationship with aberrations and spinal cord dysfunctions. Here, we provide a descriptive analysis of the anatomy, current techniques to assess the impairment of BSCB, associated risk factors and impact of spinal disorders such as spinal cord injury (SCI), amyotrophic lateral sclerosis (ALS), peripheral nerve injury (PNI), ischemia reperfusion injury (IRI), degenerative cervical myelopathy (DCM), multiple sclerosis (MS), spinal cavernous malformations (SCM) and cancer on BSCB dysfunction. Along with diagnostic and mechanistic analyses, we also provide an up-to-date account of available therapeutic options for BSCB repair. We emphasize the need to address BSCB as an individual entity and direct future research towards it.

Systemic Administration of Recombinant Irisin Accelerates Fracture Healing in Mice

To date, pharmacological strategies designed to accelerate bone fracture healing are lacking. We subjected 8-week-old C57BL/6 male mice to closed, transverse, mid-diaphyseal tibial fractures and treated them with intraperitoneal injection of a vehicle or r-irisin (100 µg/kg/weekly) immediately following fracture for 10 days or 28 days. Histological analysis of the cartilaginous callus at 10 days showed a threefold increase in Collagen Type X (p = 0.0012) and a reduced content of proteoglycans (40%; p = 0.0018). Osteoclast count within the callus showed a 2.4-fold increase compared with untreated mice (p = 0.026), indicating a more advanced stage of endochondral ossification of the callus during the early stage of fracture repair. Further evidence that irisin induced the transition of cartilage callus into bony callus was provided by a twofold reduction in the expression of SOX9 (p = 0.0058) and a 2.2-fold increase in RUNX2 (p = 0.0137). Twenty-eight days post-fracture, microCT analyses showed that total callus volume and bone volume were increased by 68% (p = 0.0003) and 67% (p = 0.0093), respectively, and bone mineral content was 74% higher (p = 0.0012) in irisin-treated mice than in controls. Our findings suggest that irisin promotes bone formation in the bony callus and accelerates the fracture repair process, suggesting a possible use as a novel pharmacologic modulator of fracture healing.

The Role of miRNAs in Extracellular Matrix Repair and Chronic Fibrotic Lung Diseases

The lung extracellular matrix (ECM) plays a key role in the normal architecture of the lung, from embryonic lung development to mechanical stability and elastic recoil of the breathing adult lung. The lung ECM can modulate the biophysical environment of cells through ECM stiffness, porosity, topography and insolubility. In a reciprocal interaction, lung ECM dynamics result from the synthesis, degradation and organization of ECM components by the surrounding structural and immune cells. Repeated lung injury and repair can trigger a vicious cycle of aberrant ECM protein deposition, accompanied by elevated ECM stiffness, which has a lasting effect on cell and tissue function. The processes governing the resolution of injury repair are regulated by several pathways; however, in chronic lung diseases such as asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary disease (IPF) these processes are compromised, resulting in impaired cell function and ECM remodeling. Current estimates show that more than 60% of the human coding transcripts are regulated by miRNAs. miRNAs are small non-coding RNAs that regulate gene expressions and modulate cellular functions. This review is focused on the current knowledge of miRNAs in regulating ECM synthesis, degradation and topography by cells and their dysregulation in asthma, COPD and IPF.

Encapsulated Mesenchymal Stromal Cell Microbeads Promote Endogenous Regeneration of Osteoarthritic Cartilage Ex Vivo

The anti-inflammatory secretome of mesenchymal stromal cells (MSCs) is lucrative for the treatment of osteoarthritis (OA), a disease characterized by low-grade inflammation. However, the precise effects of the MSC secretome on patient-derived OA tissue is lacking. To investigate these effects, alginate encapsulated MSCs are co-cultured with patient-derived OA cartilage explants for 8 days. Proteoglycan distribution in OA cartilage explants examined by Safranin O staining is markedly improved when cultured with MSC microbeads as compared to control OA explants cultured alone. Total sulfated glycosaminoglycan (sGAG) content in OA explants is significantly increased upon co-culture with MSC microbeads on day 8. The sGAG released into the culture media is unchanged by the presence of MSC microbeads, suggesting de novo sGAG synthesis in OA explants. Co-culture with MSC microbeads increased the DNA content and Ki67+ cells in OA explants, indicating proliferation. An increase in secreted cytokines IL-10, HGF, and sFAS assessed by multiplex cytokine assay, increased TIMP1 levels, and reduction in percent apoptotic cells in OA explants is noted. Together, data demonstrates that paracrine factors secreted by alginate encapsulated MSCs microbeads in response to OA cartilage, create an anabolic, proliferative, and anti-apoptotic microenvironment inducing endogenous regeneration in clinically relevant, patient-derived OA cartilage.

Immunomodulatory biomaterials and their application in therapies for chronic inflammation-related diseases

The degree of tissue injuries such as the level of scarring or organ dysfunction, and the immune response against them primarily determine the outcome and speed of healing process. The successful regeneration of functional tissues requires proper modulation of inflammation-producing immune cells and bioactive factors existing in the damaged microenvironment. In the tissue repair and regeneration processes, different types of biomaterials are implanted either alone or by combined with other bioactive factors, which will interact with the immune systems including immune cells, cytokines and chemokines etc. to achieve different results highly depending on this interplay. In this review article, the influences of different types of biomaterials such as nanoparticles, hydrogels and scaffolds on the immune cells and the modification of immune-responsive factors such as reactive oxygen species (ROS), cytokines, chemokines, enzymes, and metalloproteinases in tissue microenvironment are summarized. In addition, the recent advances of immune-responsive biomaterials in therapy of inflammation-associated diseases such as myocardial infarction, spinal cord injury, osteoarthritis, inflammatory bowel disease and diabetic ulcer are discussed.

Modeling the effects of hyaluronic acid degradation on the regulation of human astrocyte phenotype using multicomponent interpenetrating polymer networks (mIPNs)

Hyaluronic acid (HA) is a highly abundant component in the extracellular matrix (ECM) and a fundamental element to the architecture and the physiology of the central nervous system (CNS). Often, HA degradation occurs when an overreactive inflammatory response, derived from tissue trauma or neurodegenerative diseases such as Alzheimer's, causes the ECM in the CNS to be remodeled. Herein, we studied the effects of HA content as a key regulator of human astrocyte (HAf) reactivity using multicomponent interpenetrating polymer networks (mIPNs) comprised of Collagen I, HA and poly(ethylene glycol) diacrylate. The selected platform facilities the modulation of HA levels independently of matrix rigidity. Total astrocytic processes length, number of endpoints, the expression of the quiescent markers: Aldehyde Dehydrogenase 1 Family Member L1 (ALDH1L1) and Glutamate Aspartate Transporter (GLAST); the reactive markers: Glial Fibrillary Acidic Protein (GFAP) and S100 Calcium-Binding Protein β (S100β); and the inflammatory markers: Inducible Nitric Oxide Synthase (iNOS), Interleukin 1β (IL-1β) and Tumor Necrosis Factor Alpha (TNFα), were assessed. Cumulatively, our results demonstrated that the decrease in HA concentration elicited a reduction in the total length of astrocytic processes and an increase in the expression of HAf reactive and inflammatory markers.

Adenovirus-Extracellular Protein Interactions and Their Impact on Innate Immune Responses by Human Mononuclear Phagocytes

The aim of this review is to highlight how, in a syngeneic system, human mononuclear phagocytes respond to environments containing human adenovirus (HAdV) and soluble extracellular proteins that influence their innate immune response. Soluble extracellular proteins, including immunoglobulins, blood clotting factors, proteins of the complement system, and/or antimicrobial peptides (AMPs) can exert direct effects by binding to a virus capsid that modifies interactions with pattern recognition receptors and downstream signaling. In addition, the presence, generation, or secretion of extracellular proteins can indirectly influence the response to HAdVs via the activation and recruitment of cells at the site of infection.

Receptor Activator of Nuclear Factor kappa-B Ligand is Not Regulated During Chronic Osteomyelitis in Pigs

Bone loss is a major complication of osteomyelitis and from numerous in-vitro studies, it has been concluded that the bone lysis is caused by elevated expression of the receptor activator of nuclear factor κB ligand (RANKL), leading to increased osteoclast activity. However, we failed to find any relationship between bone loss and osseous RANKL expression in a porcine model of acute and chronic implant-associated osteomyelitis (IAO) due to Staphylococcus aureus or in chronic osteomyelitis lesions in slaughter pigs. Surprisingly, we found that the expression of RANKL was reduced during chronic bone infections. This is in line with the few studies conducted on human samples. A significant bone loss was observed in IAO lesions and in lesions from slaughter pigs, but with no indication of osteoclast involvement using histochemistry, immunohistochemistry for RANKL, receptor activator of nuclear factor kappa-B, osteoprotegerin and cathepsin K, and high-throughput quantitative real-time polymerase chain reaction on bone tissue from osteomyelitic lesions. A strong inflammatory response was seen in the infected animals and, therefore, we propose proteolytic enzymes induced by inflammation to be a major component of the bone loss. Furthermore, we found a significant upregulation of the IL26 gene in infected animals, which can inhibit RANKL-induced osteoclastogenesis, but has no homologue in mice. This finding emphasises that neither murine models nor in-vitro studies can mirror human disease development completely. The present study emphasises that the interactions between microorganisms, the immune system and bone cells in osteomyelitis are too complex to be accurately represented by an in-vitro model.

Aspiration-assisted bioprinting of the osteochondral interface

Osteochondral defects contain damage to both the articular cartilage and underlying subchon- dral bone, which remains a significant challenge in orthopedic surgery. Layered structure of bone, cartilage and the bone-cartilage interface must be taken into account in the case of biofabrication of the osteochondral (OC) interface. In this study, a dual layered OC interface was bioprinted using a newly developed aspiration-assisted bioprinting (AAB) technique, which has been the first time that scaffold-free bioprinting was applied to OC interface engineering. Tissue spheroids, made of human adipose-derived stem cells (ADSCs), were differentiated in three dimensions (3D) into chondrogenic and osteogenic spheroids, which were confirmed by immunostaining and histology qualitatively, and biochemistry assays and gene expression, quantitatively. Remarkably, the OC interface was bioprinted by accurate positioning of a layer of osteogenic spheroids onto a sacrificial alginate support followed by another layer of chondrogenic spheroids overlaid by the same support. Spheroids in individual zones fused and the maintenance of phenotypes in both zones confirmed the successful biofabrication of the histomorphologically-relevant OC interface. The biofabrication of OC tissue model without the use of polymeric scaffolds unveils great potential not only in regenerative medicine but also in drug testing and disease modeling for osteoarthritis.

Decellularized Extracellular Matrix-based Bioinks for Engineering Tissue- and Organ-specific Microenvironments

Biomaterials-based biofabrication methods have gained much attention in recent years. Among them, 3D cell printing is a pioneering technology to facilitate the recapitulation of unique features of complex human tissues and organs with high process flexibility and versatility. Bioinks, combinations of printable hydrogel and cells, can be utilized to create 3D cell-printed constructs. The bioactive cues of bioinks directly trigger cells to induce tissue morphogenesis. Among the various printable hydrogels, the tissue- and organ-specific decellularized extracellular matrix (dECM) can exert synergistic effects in supporting various cells at any component by facilitating specific physiological properties. In this review, we aim to discuss a new paradigm of dECM-based bioinks able to recapitulate the inherent microenvironmental niche in 3D cell-printed constructs. This review can serve as a toolbox for biomedical engineers who want to understand the beneficial characteristics of the dECM-based bioinks and a basic set of fundamental criteria for printing functional human tissues and organs.

Alterations in extracellular matrix composition during aging and photoaging of the skin

Human skin is composed of the cell-rich epidermis, the extracellular matrix (ECM) rich dermis, and the hypodermis. Within the dermis, a dense network of ECM proteins provides structural support to the skin and regulates a wide variety of signaling pathways which govern cell proliferation and other critical processes. Both intrinsic aging, which occurs steadily over time, and extrinsic aging (photoaging), which occurs as a result of external insults such as solar radiation, cause alterations to the dermal ECM. In this study, we utilized both quantitative and global proteomics, alongside single harmonic generation (SHG) and two-photon autofluorescence (TPAF) imaging, to assess changes in dermal composition during intrinsic and extrinsic aging. We find that both intrinsic and extrinsic aging result in significant decreases in ECM-supporting proteoglycans and structural ECM integrity, evidenced by decreasing collagen abundance and increasing fibril fragmentation. Intrinsic aging also produces changes distinct from those produced by photoaging, including reductions in elastic fiber and crosslinking enzyme abundance. In contrast, photoaging is primarily defined by increases in elastic fiber-associated protein and pro-inflammatory proteases. Changes associated with photoaging are evident even in young (mid 20s) sun-exposed forearm skin, indicating that proteomic evidence of photoaging is present decades prior to clinical signs of photoaging. GO term enrichment revealed that both intrinsic aging and photoaging share common features of chronic inflammation. The proteomic data has been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifier PXD015982.

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Intrinsic aging and photoaging both decrease ECM-supporting proteoglycans and structural ECM.

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Intrinsic aging produces reductions in elastic fiber and crosslinking enzyme abundance.

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Photoaging results in increases in pro-inflammatory proteases and elastic fiber abundance.

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Intrinsic aging and photoaging share common features associated with chronic inflammation.

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Proteomic changes associated with photoaging are evident decades prior to clinical aging signs.

The effect of kaempferol and apigenin on allogenic synovial membrane-derived stem cells therapy in knee osteoarthritic male rats

BACKGROUND

Based on the anti-inflammatory and anti-oxidant properties of kaempferol and apigenin, we hypothesized that co-injection of these phytochemicals would increase the effectiveness of cell therapy in knee osteoarthritic rats.

METHODS

Anterior cruciate ligament transection (ACLT) was used to induce osteoarthritis (OA). Animals were treated by weekly intra-articular injections of kaempferol (10 or 20 μM) and/or isolated MSCs from synovial membrane (SMMSCs) (3 × 106 cells), a mixture of apigenin (0.1 μM) and kaempferol alone or SMMSCs, hyaluronic acid or PBS (group size n = 6), for three weeks. After three months, the levels of IL-1β, tumor necrosis factor alpha (TNF-α), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the cartilage homogenate. Furthermore, relative expressions of collagen II2a1, aggrecan, IL-1β, TNF-α, inducible nitric oxide synthase (iNOS), SOX-9, MMP-3 and MMP-13 were assessed using real-time PCR. Radiological evaluation, before/after treatments, and histopathological assessments were carried out to evaluate the knees.

RESULTS

Non-toxic concentrations of kaempferol and apigenin determined to be 10, 20 μM and 0.1, 0.3 μM, respectively. In comparison with the OA group, the levels of TNF-α, IL-1β and MDA significantly decreased in OA + MSCs + kaempferol + apigenin group and a significant increase in SOD level was observed. The levels of MMP-13, MMP-3, TNF-α, IL-1β, iNOS were significantly decreased in the groups of OA + MSCs + A0.1 μM + K10 μM and OA + MSCs + K20 μM. Co-treatment of kaempferol and apigenin increased the gene expression levels of collagen IIa1, aggrecan and SOX-9 genes.

CONCLUSION

We showed that kaempferol and apigenin potentially increase the efficiency of OA cell therapy in the rat model of ACLT-induced OA.

Extracellular matrix-derived peptides in tissue remodeling and fibrosis

Alterations in the composition of the extracellular matrix (ECM) critically regulate the cellular responses in tissue repair, remodeling, and fibrosis. After injury, proteolytic degradation of ECM generates bioactive ECM fragments, named matricryptins, exposing cryptic sites with actions distinct from the parent molecule. Matricryptins contribute to the regulation of inflammatory, reparative, and fibrogenic cascades through effects on several different cell types both in acute and chronic settings. Fibroblasts play a major role in matricryptin generation not only as the main cellular source of ECM proteins, but also as producers of matrix-degrading proteases. Moreover, several matricryptins exert fibrogenic or reparative actions by modulating fibroblast phenotype and function. This review manuscript focuses on the mechanisms of matricyptin generation in injured and remodeling tissues with an emphasis on fibroblast-matricryptin interactions.

Ahp-Cyclodepsipeptide Inhibitors of Elastase: Lyngbyastatin 7 Stability, Scalable Synthesis, and Focused Library Analysis

Due to the potency and selectivity of lyngbyastatin 7 in inhibiting neutrophil elastase, a serine protease involved in numerous diseases, this cyclodepsipeptide was considered as a promising lead and subjected to further developmental studies. Lyngbyastatin 7 displayed a favorable serum and microsomal stability profile. The large-scale synthesis of key building blocks was performed on gram scale with improved yields and simplified purification procedures. To tailor the complex structure, define the minimal pharmacophore, and modulate the physicochemical properties of the lead scaffold, the first pilot library of analogues was designed and synthesized for structure-activity relationship studies. We uncovered the essential role of the side chain, indicating that the minimal structural requirements for elastase inhibition extended beyond the 3-amino-6-hydroxy-2-piperidone (Ahp) and 2-aminobutenoic acid (Abu) moieties conventionally known to convey antiprotease activity and elastase selectivity, respectively. Our studies will facilitate the design and development of this class of elastase inhibitors.

Comprehensive mapping of the cell response to E. coli infection in porcine intestinal epithelial cells pretreated with exopolysaccharide derived from Lactobacillus reuteri

Bacterial exopolysaccharides (EPSs) are known to modulate immunity. To date, a plethora of studies have reported the effect of EPSs on intestinal cells; however few works have revealed a complete picture of the signalling events in intestinal epithelial cells induced by bacterial EPSs. Here, using transcriptomics, we comprehensively mapped the biological processes in porcine intestinal epithelial cells challenged with EPS derived from Lactobacillus reuteri alone, enterotoxigenic Escherichia coli (ETEC) or ETEC after pretreatment with EPS. The Gene Ontology analysis of differentially expressed genes (DEGs) showed that ETEC is able to evoke biological processes specifically involved in cell junction reorganization, extracellular matrix degradation, and activation of the innate immune response through the activation of pattern recognition receptors, such as TLRs and CTRs. A total of 495 DEGs were induced in ETEC-challenged cells. On the other hand, EPS pretreatment was able to attenuate overexpression of the genes induced by ETEC infection. The most relevant finding of this study is that EPS has a suppressive effect on the inflammatory response evoked by ETEC infection. On the basis of high-throughput RNA-seq, this report is the first to describe the effects of EPSs derived from L. reuteri used as a pretreatment of global gene expression in porcine epithelial cells.

Connective tissue growth factor mediates mouse spermatogonial migration associated with differentiation

Spermatogonia migrate to the microenvironment during the establishment from gonocytes and leave it when they differentiate. However, the mechanisms underlying the regulation of spermatogonial differentiation-associated migration remain mostly unknown. In this study, we show that spermatogonial differentiation induced by retinoic acid (RA) was accompanied with increased migration ability and elevated expression of connective tissue growth factor (CTGF), a member of the CCN family. CTGF was mainly expressed in the testicular somatic cells and committed spermatogonial progenitors. Recombinant CTGF (rCTGF) promoted the spermatogonial migration and silencing of endogenous CTGF suppressed the migration of homogenous spermatogonial cell lines. Moreover, depletion of CTGF by neutralizing antibody inhibited the elevated migration ability induced by RA, suggesting both the paracrine and autocrine roles of CTGF in spermatogonial migration associated with differentiation. Finally, CTGF interacted with β1-integrin and regulated its level in spermatogonial cell lines. Together, our study provides novel insights into the regulation of spermatogonial migration by CTGF, which may shed light on the diagnosis and treatment of male infertility.

Protecting the Normal Physiological Functions of Articular and Periarticular Structures by Aurum Nanoparticle-Based Formulations: an Up-to-Date Insight

Taking the articular and periarticular structures as a litmus test for gold-based nanoformulations, the potential of gold nanoparticles in protecting the normal physiological functions of these structures particularly in geriatric patients is one of the research areas of current interest. Aside from its use to make the traditional and fashionable ornaments for human usage, the gold metal is also known for its rich therapeutic activity. This is especially true when the gold is converted from its bulk form into nanosized form before its administering into the human body. Since it is the age of nanocomponents in medical and pharmaceutical research areas, this review is therefore mainly focused on nanoparticulate systems consisting of aurum. Accumulating research reports nevertheless show concrete evidence indicating the potential of gold-based nanoformulations to manage joint syndromes such as osteoarthritis and rheumatoid arthritis. This review embarks from preparation techniques and characterization methods to therapeutical application potentials of gold-based nanoformulations.

Extracellular matrix-cell interactions: Focus on therapeutic applications

Extracellular matrix (ECM) macromolecules together with a multitude of different molecules residing in the extracellular space play a vital role in the regulation of cellular phenotype and behavior. This is achieved via constant reciprocal interactions between the molecules of the ECM and the cells. The ECM-cell interactions are mediated via cell surface receptors either directly or indirectly with co-operative molecules. The ECM is also under perpetual remodeling process influencing cell-signaling pathways on its part. The fragmentation of ECM macromolecules provides even further complexity for the intricate environment of the cells. However, as long as the interactions between the ECM and the cells are in balance, the health of the body is retained. Alternatively, any dysregulation in these interactions can lead to pathological processes and finally to various diseases. Thus, therapeutic applications that are based on retaining normal ECM-cell interactions are highly rationale. Moreover, in the light of the current knowledge, also concurrent multi-targeting of the complex ECM-cell interactions is required for potent pharmacotherapies to be developed in the future.

MicroRNA Mediate Visfatin and Resistin Induction of Oxidative Stress in Human Osteoarthritic Synovial Fibroblasts Via NF-κB Pathway

Synovial membrane inflammation actively participate to structural damage during osteoarthritis (OA). Adipokines, miRNA, and oxidative stress contribute to synovitis and cartilage destruction in OA. We investigated the relationship between visfatin, resistin and miRNA in oxidative stress regulation, in human OA synovial fibroblasts. Cultured cells were treated with visfatin and resistin. After 24 h, we evaluated various pro-inflammatory cytokines, metalloproteinases (MMPs), type II collagen (Col2a1), miR-34a, miR-146a, miR-181a, antioxidant enzymes, and B-cell lymphoma (BCL)2 by qRT-PCR, apoptosis and mitochondrial superoxide production by cytometry, p50 nuclear factor (NF)-κB by immunofluorescence. Synoviocytes were transfected with miRNA inhibitors and oxidative stress evaluation after adipokines stimulus was performed. The implication of NF-κB pathway was assessed by the use of a NF-κB inhibitor (BAY-11-7082). Visfatin and resistin significantly up-regulated gene expression of interleukin (IL)-1β, IL-6, IL-17, tumor necrosis factor (TNF)-α,MMP-1, MMP-13 and reduced Col2a1. Furthermore, adipokines induced apoptosis and superoxide production, the transcriptional levels of BCL2, superoxide dismutase (SOD)-2, catalase (CAT), nuclear factor erythroid 2 like 2 (NRF2), miR-34a, miR-146a, and miR-181a. MiRNA inhibitors counteracted adipokines modulation of oxidative stress. Visfatin and resistin effects were suppressed by BAY-11-7082. Our data suggest that miRNA may represent possible mediators of oxidative stress induced by visfatin and resistin via NF-κB pathway in human OA synoviocytes.

Duchesnea indica extract attenuates oral cancer cells metastatic potential through the inhibition of the matrix metalloproteinase-2 activity by down-regulating the MEK/ERK pathway

BACKGROUND

Duchesnea indica (Andr.) Focke, an herb in folk medicine used extensively in traditional Chinese medicine, has cytostatic properties as well as antioxidant and antimetastasis activities in various cancer cells. However, the effects and underlying mechanisms of Duchesnea indica extracts (DIEs) on human oral squamous cell carcinoma (OSCC) metastases remain unclear.

PURPOSE

In this study, we posit the hypothesis that DIE possesses antimetastatic effects on human OSCC cells.

METHODS

The effects of DIE on cell viability, motility, migration, and invasion were investigated. Gelatin zymography, Western blotting, migration and invasion assays were used to further study the underlying mechanisms involved in the antimetastatic effects of DIE in OSCC cells.

RESULTS

The results from MTT assay revealed that DIE did not affect the cell viability of OSCC cells. Moreover, DIE significantly attenuated OSCC cells' motility, migration, and invasion by reducing the MMP-2 protein expression and MMP-2 activity in a dose-dependent manner. In addition, DIE reduced the phosphorylation of both ERK1/2 and its upstream kinase but had no effect on the phosphorylation of p38 and JNK.

CONCLUSION

DIE triggers the antimetastatic activity in OSCC cells by suppressing the MMP-2 activity via the MEK/ERK signaling pathways. Therefore, these findings are promising for the use of DIE antimetastatic activity in oral cancer metastasis treatment.

Cellular Invasion and Matrix Degradation, a Different Type of Matrix-Degrading Cells in the Cartilage of Catfish (Clarias gariepinus) and Japanese Quail Embryos (Coturnix coturnix japonica)

We previously studied the phenomena of the mesenchymal cell-dependent mode of cartilage growth in quail and catfish. Thus, we selected the two cartilage models in which mesenchymal cells participate in their growth. In such models, cartilage degradation occurred to facilitate cellular invasion. The studies do not explain the nature of the cartilage degrading cells. The current study aims to explore the nature of the cartilage-degrading cells using transmission electron microscopy (TEM) and immunohistochemistry. Samples of cartilage have been isolated from the air-breathing organ of catfish and the cartilage of the prospective occipital bone of quail embryos. Samples have been processed for TEM and immunohistochemistry. We found that two different cell types are involved in cartilage degradation; the macrophage in the cartilage of catfish and mesenchymal cells in the cartilage of the quail. Areas of cellular invasion in both catfish cartilage and quail embryo cartilage had an immunological affinity for MMP-9. In catfish, cartilage-degrading cells had identical morphological features of macrophages, whereas in quail embryos, cartilage-degrading cells were mesenchymal-like cells which had cell processes rich in vesicles and expressed CD117. Further study should consider the role of macrophage and mesenchymal cells during cartilage degradation. This could be valuable to be applied to remove the defective cartilage matrix formed in osteoarthritic patients to improve cartilage repair strategies.

Bone marrow concentrate-induced mesenchymal stem cell conditioned medium facilitates wound healing and prevents hypertrophic scar formation in a rabbit ear model

Background

Hypertrophic scars (HSs) are formed via an aberrant response to the wound healing process. HSs can be cosmetic or can result in functional problems. Prolonged proliferation and remodeling phases disrupt wound healing, leading to excessive collagen production and HS formation. However, there are currently no satisfactory drugs to prevent HS formation. Mesenchymal stem cell (MSC) conditioned medium (CM) has therapeutic effects on wound healing and preventing HS formation. Bone marrow concentrate (BMC) contains various growth factors and cytokines that are crucial for regeneration and has been applied in the clinical setting. In this study, we evaluated the effects of BMC-induced MSC CM on HS formation in a rabbit ear model.

Methods

We established a rabbit ear wound model by generating full-thickness wounds in the ears of rabbits (n = 12) and treated wounds with MSC CM, BMC CM, or BMC-induced MSC CM. Dermal fibroblasts from human hypertrophic scar were stimulated with transforming growth factor beta 1 (TGF-β1) for 24 h and cultured in each culture medium for 72 h. We measured the hypertrophic scar (HS) formation during the skin regeneration by measuring the expression of several remodeling molecules and the effect of these conditioned media on active human HS fibroblasts.

Results

Our results showed that BMC-induced MSC CM had greater antifibrotic effects than MSC CM and BMC CM significantly attenuated HS formation in rabbits. BMC-induced MSC CM accelerated wound re-epithelization by increasing cell proliferation. Additionally, BMC-induced MSC CM also inhibited fibrosis by decreasing profibrotic gene and protein expression, promoting extracellular matrix turnover, inhibiting fibroblast contraction, and reversing myofibroblast activation.

Conclusions

BMC-induced MSC CM modulated the proliferation and remodeling phases of wound healing, representing a potential wound healing agent and approach for preventing HS formation.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1383-x) contains supplementary material, which is available to authorized users.

The Bone Extracellular Matrix as an Ideal Milieu for Cancer Cell Metastases

Bone is a preferential site for cancer metastases, including multiple myeloma, prostate, and breast cancers.The composition of bone, especially the extracellular matrix (ECM), make it an attractive site for cancer cell colonization and survival. The bone ECM is composed of living cells embedded within a matrix composed of both organic and inorganic components. Among the organic components, type I collagen provides the tensile strength of bone. Inorganic components, including hydroxyapatite crystals, are an integral component of bone and provide bone with its rigidity. Under normal circumstances, two of the main cell types in bone, the osteoblasts and osteoclasts, help to maintain bone homeostasis and remodeling through cellular communication and response to biophysical signals from the ECM. However, under pathological conditions, including osteoporosis and cancer, bone remodeling is dysregulated. Once in the bone matrix, disseminated tumor cells utilize normal products of bone remodeling, such as collagen type I, to fuel cancer cell proliferation and lesion outgrowth. Models to study the complex interactions between the bone matrix and metastatic cancer cells are limited. Advances in understanding the interactions between the bone ECM and bone metastatic cancer cells are necessary in order to both regulate and prevent metastatic cancer cell growth in bone.

Rosa canina - Rose hip pharmacological ingredients and molecular mechanics counteracting osteoarthritis - A systematic review

BACKGROUND

The successful use of rose hip for the treatment of osteoarthritis is well documented. Several randomized placebo controlled double-blind studies, as mono or combination therapy, have demonstrated treatment efficacy as well as excellent tolerability.

PURPOSE

This review focuses on the molecular mechanism underlying the clinical effects of rose hip in osteoarthritis (OA).

METHODS

The database Medline was screened - using the search term "Rosa canina" or "rose hip" - for publications on pharmacological or mechanistic studies with relevance to OA; in addition for findings on pharmacologically active constituents as well as clinical studies. The screening results were complemented by following-up on cited literature.

RESULTS

In particular, 24 pharmacological studies on Rosa canina or preparations thereof were considered relevant. Potent antioxidant radical scavenging effects are well documented for numerous rose hip constituents besides Vitamin C. Furthermore, anti-inflammatory activities include the reduction of pro-inflammatory cytokines and chemokines, reduction of NF-kB signaling, inhibition of pro-inflammatory enzymes, including COX1/2, 5-LOX and iNOS, reduction of C-reactive protein levels, reduction of chemotaxis and chemoluminescence of PMNs, and an inhibition of pro-inflammatory metalloproteases.

CONCLUSION

The antioxidant and anti-inflammatory effects of Rosa canina match its clinical action - especially considering new findings on the pharmacological disease pattern of OA. The entirety of several compounds including phenolics, terpenoids, galactolipids, carotenoids, fruit acids and fatty oils can be considered responsible for the observed pharmacological and clinical effects. Further research is needed to eludicate how and in which manner single rose hip compounds interact with their molecular pharmacological targets.

Histochemical and Ultrastructural Study of Developing Gonial Bone With Reference to Initial Ossification of the Malleus and Reduction of Meckel's Cartilage in Mice

Development of mouse gonial bone and initial ossification process of malleus were investigated. Before the formation of the gonial bone, the osteogenic area expressing alkaline phosphatase and Runx2 mRNA was widely recognized inferior to Meckel's cartilage. The gonial bone was first formed within the perichondrium at E16.0 via intramembranous ossification, surrounded the lower part of Meckel's cartilage, and then continued to extend anteriorly and medially until postnatal day (P) 3.0. At P0, multinucleated chondroclasts started to resorb the mineralized cartilage matrix with ruffled borders at the initial ossification site of the malleus (most posterior part of Meckel's cartilage). Almost all CD31-positive capillaries did not run through the gonial bone but entered the cartilage through the site where the gonial bone was not attached, indicating the forms of the initial ossification site of the malleus are similar to those at the secondary ossification center rather than the primary ossification center in the long bone. Then, the reducing process of the posterior part of Meckel's cartilage with extending gonial bone was investigated. Numerous tartrate-resistant acid phosphatase-positive mononuclear cells invaded the reducing Meckel's cartilage, and the continuity between the malleus and Meckel's cartilage was completely lost by P3.5. Both the cartilage matrix and the perichondrium were degraded, and they seemed to be incorporated into the periosteum of the gonial bone. The tensor tympani and tensor veli palatini muscles were attached to the ligament extending from the gonial bone. These findings indicated that the gonial bone has multiple functions and plays important roles in cranial formation. Anat Rec, 302:1916-1933, 2019. © 2019 American Association for Anatomy.

Continuous Compressive Force Induces Differentiation of Osteoclasts with High Levels of Inorganic Dissolution

Background

Osteoclast precursor cells are constitutively differentiated into mature osteoclasts on bone tissues. We previously reported that the continuous stimulation of RAW264.7 precursor cells with compressive force induces the formation of multinucleated giant cells via receptor activator of nuclear factor κB (RANK)-RANK ligand (RANKL) signaling. Here, we examined the bone resorptive function of multinucleated osteoclasts induced by continuous compressive force.

Material/Methods

Cells were continuously stimulated with 0.3, 0.6, and 1.1 g/cm² compressive force created by increasing the amount of the culture solution in the presence of RANKL. Actin ring organization was evaluated by fluorescence microscopy. mRNA expression of genes encoding osteoclastic bone resorption-related enzymes was examined by quantitative real-time reverse transcription-polymerase chain reaction. Mineral resorption was evaluated using calcium phosphate-coated plates.

Results

Multinucleated osteoclast-like cells with actin rings were observed for all three magnitudes of compressive force, and the area of actin rings increased as a function of the applied force. Carbonic anhydrase II expression as well as calcium elution from the calcium phosphate plate was markedly higher after stimulation with 0.6 and 1.1 g/cm² force than 0.3 g/cm². Matrix metalloproteinase-9 expression decreased and cathepsin K expression increased slightly by the continuous application of compressive force.

Conclusions

Our study demonstrated that multinucleated osteoclast-like cells induced by the stimulation of RAW264.7 cells with continuous compressive force exhibit high dissolution of the inorganic phase of bone by upregulating carbonic anhydrase II expression and actin ring formation. These findings improve our understanding of the role of mechanical load in bone remodeling.

Discerning the spatio-temporal disease patterns of surgically induced OA mouse models

Osteoarthritis (OA) is the most common cause of disability in ageing societies, with no effective therapies available to date. Two preclinical models are widely used to validate novel OA interventions (MCL-MM and DMM). Our aim is to discern disease dynamics in these models to provide a clear timeline in which various pathological changes occur. OA was surgically induced in mice by destabilisation of the medial meniscus. Analysis of OA progression revealed that the intensity and duration of chondrocyte loss and cartilage lesion formation were significantly different in MCL-MM vs DMM. Firstly, apoptosis was seen prior to week two and was narrowly restricted to the weight bearing area. Four weeks post injury the magnitude of apoptosis led to a 40-60% reduction of chondrocytes in the non-calcified zone. Secondly, the progression of cell loss preceded the structural changes of the cartilage spatio-temporally. Lastly, while proteoglycan loss was similar in both models, collagen type II degradation only occurred more prominently in MCL-MM. Dynamics of chondrocyte loss and lesion formation in preclinical models has important implications for validating new therapeutic strategies. Our work could be helpful in assessing the feasibility and expected response of the DMM- and the MCL-MM models to chondrocyte mediated therapies.

Cell-Cell Mechanical Communication in Cancer

Communication between cancer cells enables cancer progression and metastasis. While cell-cell communication in cancer has primarily been examined through chemical mechanisms, recent evidence suggests that mechanical communication through cell-cell junctions and cell-ECM linkages is also an important mediator of cancer progression. Cancer and stromal cells remodel the ECM through a variety of mechanisms, including matrix degradation, cross-linking, deposition, and physical remodeling. Cancer cells sense these mechanical environmental changes through cell-matrix adhesion complexes and subsequently alter their tension between both neighboring cells and the surrounding matrix, thereby altering the force landscape within the microenvironment. This communication not only allows cancer cells to communicate with each other, but allows stromal cells to communicate with cancer cells through matrix remodeling. Here, we review the mechanisms of intercellular force transmission, the subsequent matrix remodeling, and the implications of this mechanical communication on cancer progression.

A Complex Relationship between Visfatin and Resistin and microRNA: An In Vitro Study on Human Chondrocyte Cultures

Growing evidence indicates the important role of adipokines and microRNA (miRNA) in osteoarthritis (OA) pathogenesis. The purpose of the present study was to investigate the effect of visfatin and resistin on some miRNA (34a, 140, 146a, 155, 181a, let-7e), metalloproteinases (MMPs), and collagen type II alpha 1 chain (Col2a1) in human OA chondrocytes and in the T/C-28a2 cell line. The implication of nuclear factor (NF)-κB in response to adipokines was also assessed. Chondrocytes were stimulated with visfatin (5 or 10 μg/mL) and resistin (50 or 100 ng/mL) with or without NF-κB inhibitor (BAY-11-7082, 1 μM) for 24 h. Viability and apoptosis were detected by MMT and cytometry, miRNA, MMP-1, MMP-13, and Col2a1 by qRT-PCR and NF-κB activation by immunofluorescence. Visfatin and resistin significantly reduced viability, induced apoptosis, increased miR-34a, miR-155, miR-181a, and miR-let7e, and reduced miR-140 and miR-146a gene expression in OA chondrocytes. MMP-1, MMP-13, and Col2a1 were significantly modulated by treatment of OA chondrocytes with adipokines. Visfatin and resistin significantly increased NF-κB activation, while the co-treatment with BAY11-7082 did not change MMPs or Col2a1 levels beyond that caused by single treatment. Visfatin and resistin regulate the expression levels of some miRNA involved in OA pathogenesis and exert catabolic functions in chondrocytes via the NF-κB pathway. These data confirm the complex relationship between adipokines and miRNA.

Methylsulfonylmethane and mobilee prevent negative effect of IL-1β in human chondrocyte cultures via NF-κB signaling pathway

Nutraceuticals are compounds that serve as nutrition with an easy accessibility and favourable safety profile. Recent studies showed their potential activity on osteoarthritis (OA) inflammation and cartilage metabolism. We investigated the effect of methylsulfonylmethane (MSM) and mobilee in human OA chondrocyte cultures exposed to interleukin (IL)-1β. OA cartilage was obtained from femoral heads of five patients undergoing total replacement surgery. Chondrocytes were incubated with mobilee (200 and 500 μM) and MSM (2000 and 6000 μM) in presence of IL-1β (10 ng/mL) and nuclear factor (NF)-κB inhibitor (BAY 11-7082, 1 μM), for 24 and 48 h. Viability and apoptosis were performed by MMT and flow cytometry. The metalloproteinase (MMP)-1,-3,-13 and type II collagen (Col2a1) were analyzed by qRT-PCR and ELISA, and NF-κB activation by immunofluorescence. IL-1β stimulus determined a significant regulation of survival, apoptotic ratio, as well as of gene expression and serum levels of MMP-1,-3,-13 and Col2a1 in OA chondrocytes compared to baseline. Mobilee and MSM incubation significantly reversed the effect of IL-1β. IL-1β significantly induced NF-κB p50 nuclear translocation, which was significantly counteracted by the pre-treatment of OA chodrocytes with the tested compounds. BAY11-7082 significantly modulated MMPs and Col2a1 expression respectively to basal state. Co-treatment of IL-1β with mobilee, MSM and BAY11-7082 didn't cause changes of MMPs or Col2a1 beyond that caused by each single treatment. We demonstrated that MSM and mobilee have a beneficial effect on OA chondrocytes metabolism, probably due to the modulation of NF-κB pathway, providing a powerful rationale for the use of these substances in OA treatment.