Angiogenesis induced by degradation products of hyaluronic acid

Pro-inflammatory cytokines suppress HYBID (hyaluronan (HA) -binding protein involved in HA depolymerization/KIAA1199/CEMIP) -mediated HA metabolism in human skin fibroblasts

In the skin, the metabolism of hyaluronan (HA) is highly regulated. Aging leads to chronic low-grade inflammation, which is characterized by elevated levels of pro-inflammatory cytokines; however, the relationship between inflammation and HA metabolism is not clear. Herein, we investigated the effects of a mixture of pro-inflammatory cytokines containing TNF-α, IL-1β, and IL-6 on HA metabolism in human skin fibroblasts. Treatment with the cytokine mixture for 24 h suppressed HA depolymerization via downregulation of HYBID (HA-binding protein involved in HA depolymerization/KIAA1199/CEMIP) and promoted HA synthesis via upregulation of HAS2 in human skin fibroblasts. Moreover, HAS2-dependent HA synthesis was driven mainly by IL-1β with partial contribution from TNF-α. Transmembrane protein 2 (TMEM2/CEMIP2), which was previously reported as a candidate hyaluronidase, was upregulated by the cytokine mixture, suggesting that TMEM2 might not function as a hyaluronidase in human skin fibroblasts. Furthermore, the effects of the cytokine mixture on HA metabolism were observed in fibroblasts after 8 days of treatment with cytokines during three passages. Thus, we have shown that HYBID-mediated HA metabolism is negatively regulated by the pro-inflammatory cytokine mixture, providing novel insights into the relationship between inflammation and HA metabolism in the skin.

Hyaluronan Degradation by Cemip Regulates Host Defense against Staphylococcus aureus Skin Infection

Staphylococcus aureus is a major human bacterial pathogen responsible for deep tissue skin infections. Recent observations have suggested that rapid, localized digestion of hyaluronic acid in the extracellular matrix (ECM) of the dermis may influence bacterial invasion and tissue inflammation. In this study we find that cell migration-inducing protein (Cemip) is the major inducible gene responsible for hyaluronan catabolism in mice. Cemip^−/− mice failed to digest hyaluronan and had significantly less evidence of infection after intradermal bacterial challenge by S. aureus. Stabilization of large-molecular-weight hyaluronan enabled increased expression of cathelicidin antimicrobial peptide (Camp) that was due in part to enhanced differentiation of preadipocytes to adipocytes, as seen histologically and by increased expression of Pref1, PPARg, and Adipoq. Cemip^−/− mice challenged with S. aureus also had greater IL-6 expression and neutrophil infiltration. These observations describe a mechanism for hyaluronan in the dermal ECM to regulate tissue inflammation and host antimicrobial defense.

In this paper, Dokoshi et al. describe how the mammalian hyaluronidase Cemip is induced in the dermis during S. aureus infection. Cemip digests hyaluronan in the skin to regulate reactive adipogenesis and subsequent antimicrobial activity and skin inflammation.

Hyaluronan and Its Receptors as Regulatory Molecules of the Endothelial Interface

On the surface of endothelial cells (ECs) lies the glycocalyx, a barrier of polysaccharides that isolates the ECs from the blood. The role of the glycocalyx is dynamic and complex, thanks to not only its structure, but its vast number of components, one being hyaluronan (HA). HA is a critical component of the glycocalyx, having been found to have a wide variety of functions depending on its molecular weight, its modification, and receptor-ligand interactions. As HA and viscous blood are in constant contact, HA can transmit mechanosensory information directly to the cytoskeleton of the ECs. The degradation and synthesis of HA directly alters the permeability of the EC barrier; HA modulation not only alters the physical barrier but also can signal the initiation of other pathways. EC proliferation and angiogenesis are in part regulated by HA fragmentation, HA-dependent receptor binding, and downstream signals. The interaction between the CD44 receptor and HA is a driving force behind leukocyte recruitment, but each class of leukocyte still interacts with HA in unique ways during inflammation. HA regulates a diverse repertoire of EC functions.

Hyal2 Expression in Tumor-Associated Myeloid Cells Mediates Cancer-Related Inflammation in Bladder Cancer

The increased presence of myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) in tumor tissue has been extensively reported. However, their role in the regulation of hyaluronan (HA) metabolism in the tumor microenvironment has not been established. Here we describe a novel function of tumor-associated myeloid cells related to the enhanced breakdown of extracellular HA in human bladder cancer tissue, leading to the accumulation of small HA fragments with molecular weight (MW) <20 kDa. Increased fragmentation of extracellular HA and accumulation of low molecular weight HA (LMW-HA) in tumor tissue was associated with elevated production of multiple inflammatory cytokines, chemokines, and angiogenic factors. The fragmentation of HA by myeloid cells was mediated by the membrane-bound enzyme hyaluronidase 2 (Hyal2). Increased numbers of Hyal2⁺CD11b⁺ myeloid cells were detected in the tumor tissue as well as in the peripheral blood of patients with bladder cancer. Coexpression of CD33 suggested that these cells belong to monocytic myeloid-derived suppressor cells. The HA-degrading function of Hyal2-expressing MDSCs could be enhanced by exposure to tumor-conditioned medium, and IL1β was identified as one of the factors involved in the stimulation of Hyal2 activity. CD44-mediated signaling played an important role in the regulation of HA-degrading activity of Hyal2-expressing myeloid cells, as the engagement of CD44 receptor with specific mAb triggered translocation of Hyal2 enzyme to the cellular surface and stimulated secretion of IL1β. Taken together, this work identifies Hyal2-expressing tumor-associated myeloid cells as key players in the accumulation of LMW-HA in the tumor microenvironment and cancer-related inflammation and angiogenesis. SIGNIFICANCE: This study identifies Hyal2-expressing tumor-associated myeloid cells of monocyte-macrophage lineage as contributors to hyaluronan degradation in bladder cancer tissue, leading to accumulation of inflammatory and proangiogenic low molecular weight hyaluronan fragments.

Dose- and time-dependent effects of hyaluronidase on structural cells and the extracellular matrix of the skin

Introduction

Hyaluronic acid (hyaluronan; HA) is an essential component of the extracellular matrix (ECM) of the skin. The HA-degrading enzyme hyaluronidase (HYAL) is critically involved in the HA-metabolism. Yet, only little information is available regarding the skin’s HA–HYAL interactions on the molecular and cellular levels.

Objective

To analyze the dose- and time-dependent molecular and cellular effects of HYAL on structural cells and the HA-metabolism in the skin.

Materials and methods

Chip-based, genome-wide expression analyses (Affymetrix® GeneChip PrimeView™ Human Gene Expression Array), quantitative real-time PCR analyses, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (DAB), and in vitro wound healing assays were performed to assess dose-dependent and time-kinetic effects of HA and HYAL (bovine hyaluronidase, Hylase “Dessau”) on normal human dermal fibroblasts (NHDF), primary human keratinocytes in vitro and human skin samples ex vivo.

Results

Genome-wide expression analyses revealed an upregulation of HA synthases (HAS) up to 1.8-fold change in HA- and HYAL-treated NHDF. HA and HYAL significantly accelerated wound closure in an in vitro model for cutaneous wound healing. HYAL induced HAS1 and HAS2 mRNA gene expression in NHDF. Interestingly, low concentrations of HYAL (0.015 U/ml) resulted in a significantly higher induction of HAS compared to moderate (0.15 and 1.5 U/ml) and high concentrations (15 U/ml) of HYAL. This observation corresponded to increased concentrations of HA measured by ELISA in conditioned supernatants of HYAL-treated NHDF with the highest concentrations observed for 0.015 U/ml of HYAL. Finally, immunohistochemical analysis of human skin samples incubated with HYAL for up to 48 h ex vivo demonstrated that low concentrations of HYAL (0.015 U/ml) led to a pronounced accumulation of HA, whereas high concentrations of HYAL (15 U/ml) reduced dermal HA-levels.

Conclusion

HYAL is a bioactive enzyme that exerts multiple effects on the HA-metabolism as well as on the structural cells of the skin. Our results indicate that HYAL promotes wound healing and exerts a dose-dependent induction of HA-synthesis in structural cells of the skin. Herein, interestingly the most significant induction of HAS and HA were observed for the lowest concentration of HYAL.

Immunomodulatory Role of the Extracellular Matrix Within the Liver Disease Microenvironment

Chronic liver disease when accompanied by underlying fibrosis, is characterized by an accumulation of extracellular matrix (ECM) proteins and chronic inflammation. Although traditionally considered as a passive and largely architectural structure, the ECM is now being recognized as a source of potent damage-associated molecular pattern (DAMP)s with immune-active peptides and domains. In parallel, the ECM anchors a range of cytokines, chemokines and growth factors, all of which are capable of modulating immune responses. A growing body of evidence shows that ECM proteins themselves are capable of modulating immunity either directly via ligation with immune cell receptors including integrins and TLRs, or indirectly through release of immunoactive molecules such as cytokines which are stored within the ECM structure. Notably, ECM deposition and remodeling during injury and fibrosis can result in release or formation of ECM-DAMPs within the tissue, which can promote local inflammatory immune response and chemotactic immune cell recruitment and inflammation. It is well described that the ECM and immune response are interlinked and mutually participate in driving fibrosis, although their precise interactions in the context of chronic liver disease are poorly understood. This review aims to describe the known pro-/anti-inflammatory and fibrogenic properties of ECM proteins and DAMPs, with particular reference to the immunomodulatory properties of the ECM in the context of chronic liver disease. Finally, we discuss the importance of developing novel biotechnological platforms based on decellularized ECM-scaffolds, which provide opportunities to directly explore liver ECM-immune cell interactions in greater detail.

The role of hyaluronic acid and amino acid against the aging of the human skin: A clinical and histological study

BACKGROUND

In esthetic medicine, different techniques have been used against the aging of the human skin especially in the facial area. Hyaluronic acid is used for improving the quantity of water and extracellular matrix molecule. The aim of this study is a clinical and histological evaluation of the effect of low-molecular-weight hyaluronic acid fragments mixed with amino acid (HAAM) on the rejuvenation the face skin treated with intradermal microinjections.

METHODS

Twenty women with mean age 45 range from 35 to 64 were studied, thereof 8 in menopause and 12 of childbearing age. The patients were treated with the HAAM products by mesotherapy technique; before and after 3 months of the therapeutic procedure, each patient underwent small biopsies with a circular punch biopsy.

RESULTS

The clinical results of the present study showed that the administration of the dermal filler containing fragments of hyaluronic acid between 20 and 38 monomers and amino acid via dermis injection technique produces an esthetic improvement in the faces of the treated patients, while the histological evaluation shows an increased fibroblast activity with the production of type III reticular collagen and increased number of vessels and epidermis thickness.

CONCLUSIONS

The clinical and histological assessment showed that subcutaneous HAAM infiltration has a significant impact on the dermis and clinical aspects of the face.

Angiogenic Potential in Biological Hydrogels

Hydrogels are three-dimensional (3D) materials able to absorb and retain water in large amounts while maintaining their structural stability. Due to their considerable biocompatibility and similarity with the body’s tissues, hydrogels are one of the most promising groups of biomaterials. The main application of these hydrogels is in regenerative medicine, in which they allow the formation of an environment suitable for cell differentiation and growth. Deriving from these hydrogels, it is, therefore, possible to obtain bioactive materials that can regenerate tissues. Because vessels guarantee the right amount of oxygen and nutrients but also assure the elimination of waste products, angiogenesis is one of the processes at the base of the regeneration of a tissue. On the other hand, it is a very complex mechanism and the parameters to consider are several. Indeed, the factors and the cells involved in this process are numerous and, for this reason, it has been a challenge to recreate a biomaterial able to adequately sustain the angiogenic process. However, in this review the focal point is the application of natural hydrogels in angiogenesis enhancing and their potential to guide this process.

Novel technique for the simultaneous isolation of cardiac fibroblasts and epicardial stromal cells from the infarcted murine heart

AIMS

Myocardial infarction (MI) leads to activation of cardiac fibroblasts (aCFs) and at the same time induces the formation of epicardium-derived cells at the heart surface. To discriminate between the two cell populations, we elaborated a fast and efficient protocol for the simultaneous isolation and characterization of aCFs and epicardial stromal cells (EpiSCs) from the infarcted mouse heart.

METHODS AND RESULTS

For the isolation of aCFs and EpiSCs, infarcted hearts (50 min ischaemia/reperfusion) were digested by perfusion with a collagenase-containing medium for only 8 min, while EpiSCs were enzymatically removed from the outside by applying mild shear forces via a motor driven device. Cardiac fibroblasts (CFs) isolated from unstressed hearts served as control. Viability of isolated cells was >90%. Purity of EpiSCs was confirmed by immunofluorescence staining and qPCR of various mesenchymal markers including Wilms-tumor-protein-1. Microarray analysis of CFs, aCFs, and EpiSCs on day 5 post-MI revealed a unique gene expression pattern in the EpiSC fraction, which was enriched for epithelial markers and epithelial to mesenchymal transition-related genes. Compared to aCFs, 336 significantly altered gene entities were identified in the EpiSC fraction. qPCR analysis showed high expression of Serpinb2, Cxcl13, Adora2b, and Il10 in EpiSCs relative to CFs and aCFs. Furthermore, microarray data identified Ddah1 and Cemip to be highly up-regulated in aCFs compared to CFs. Immunostaining of the infarcted heart revealed a unique distribution of Dermokine, Aquaporin-1, Cytokeratin, Lipocalin2, and Periostin within the epicardial cell layer.

CONCLUSIONS

We describe the simultaneous isolation of viable, purified fractions of aCFs and EpiSCs from the infarcted mouse heart. In this study, several differentially expressed markers for aCFs and EpiSCs were identified, underlining the importance of cell separation to study heterogeneity of stromal cells in the healing process after MI.

Tumor microenvironment targeting with dual stimuli-responsive nanoparticles based on small heat shock proteins for antitumor drug delivery

Tumour microenvironment (TME)-targeting nanoparticles (NPs) were developed based on Methanococcus jannaschii small heat shock proteins (Mj-sHSPs). Transactivator of transcription (TAT) were modified on the surface of Mj-sHSPs (T-HSPs) to enhance their cellular internalization ability (CIA), and a pH/enzyme dual sensitive PEG/N-(2-aminoethyl)piperidine-hyaluronic acid (PAHA) coat was combined with T-HSPs (PT-HSPs). PT-HSP NPs exhibited multi-layered morphologies and good stability against plasma protein adsorption. The release of paclitaxel (PTX) from PT-HSP NPs was negligible at physiological pH. Under conditions similar to the TME (acidic pH and overexpressed hyaluronidase (HAase)), the PAHA coat deshielded from PT-HSP NPs because of two factors: charge reversal and HAase degradation. Once the PAHA coat was shed, the size of the NPs decreased; its surface charge became positive; and remarkable drug release was triggered. Cellular experiments indicated that the CIA of PT-HSPs was shielded in the microenvironment of normal cells and recovered in that of tumour cells. In vivo imaging exhibited that the PT-HSP NPs had an impressive tumour targeting ability compared with the uncoated controls. The antitumor efficacy in vivo demonstrated that tumour-bearing mice treated with PTX-loaded PT-HSP NPs achieved better anti-tumour effects and safety than the Taxol formulation. In summary, this study provided Mj-sHSP NPs with coats that could be shed in response to the particular pH and enzymes in the TME, which improved the efficacy of tumour therapy. STATEMENT OF SIGNIFICANCE: This study reports on tumor microenvironment-targeting protein-based nanoparticles (PT-HSP NPs) for targeted tumor therapy. The NPs had a multilayered structure: a protein cage, a TAT cationic layer, and a dual-sensitive coat. PT-HSP NPs exhibited multilayered morphology, with good stability against plasma protein adsorption, and PTX release negligible at physiological pH. Under the tumor microenvironment (acidic pH and overexpressed HAase), PAHA coat deshielded from PT-HSP NPs due to two factors: the charge reversal induced by protonation of piperidines in PAHA and HAase degradation. The results of cellular uptake, cytotoxicity, in vivo imaging, and tumor inhibition experiments confirmed that PT-HSP NPs exhibited promising tumor targeting efficacy in vitro and in vivo.

Roles of Proteoglycans and Glycosaminoglycans in Cancer Development and Progression

The extracellular matrix (ECM) spatiotemporally controls cell fate; however, dysregulation of ECM remodeling can lead to tumorigenesis and cancer development by providing favorable conditions for tumor cells. Proteoglycans (PGs) and glycosaminoglycans (GAGs) are the major macromolecules composing ECM. They influence both cell behavior and matrix properties through direct and indirect interactions with various cytokines, growth factors, cell surface receptors, adhesion molecules, enzymes, and glycoproteins within the ECM. The classical features of PGs/GAGs play well-known roles in cancer angiogenesis, proliferation, invasion, and metastasis. Several lines of evidence suggest that PGs/GAGs critically affect broader aspects in cancer initiation and the progression process, including regulation of cell metabolism, serving as a sensor of ECM's mechanical properties, affecting immune supervision, and participating in therapeutic resistance to various forms of treatment. These functions may be implemented through the characteristics of PGs/GAGs as molecular bridges linking ECM and cells in cell-specific and context-specific manners within the tumor microenvironment (TME). In this review, we intend to present a comprehensive illustration of the ways in which PGs/GAGs participate in and regulate several aspects of tumorigenesis; we put forward a perspective regarding their effects as biomarkers or targets for diagnoses and therapeutic interventions.

Diverse Roles for Hyaluronan and Hyaluronan Receptors in the Developing and Adult Nervous System

Hyaluronic acid (HA) plays a vital role in the extracellular matrix of neural tissues. Originally thought to hydrate tissues and provide mechanical support, it is now clear that HA is also a complex signaling molecule that can regulate cell processes in the developing and adult nervous systems. Signaling properties are determined by molecular weight, bound proteins, and signal transduction through specific receptors. HA signaling regulates processes such as proliferation, differentiation, migration, and process extension in a variety of cell types including neural stem cells, neurons, astrocytes, microglia, and oligodendrocyte progenitors. The synthesis and catabolism of HA and the expression of HA receptors are altered in disease and influence neuroinflammation and disease pathogenesis. This review discusses the roles of HA, its synthesis and breakdown, as well as receptor expression in neurodevelopment, nervous system function and disease.

Why Chain Length of Hyaluronan in Eye Drops Matters

The chain length of hyaluronan (HA) determines its physical as well as its physiological properties. Results of clinical research on HA eye drops are not comparable without this parameter. In this article methods for the assessment of the average molecular weight of HA in eye drops and a terminology for molecular weight ranges are proposed. The classification of HA eye drops according to their zero shear viscosity and viscosity at 1000 s-1 shear rate is presented. Based on the gradient of mucin MUC5AC concentration within the mucoaqueous layer of the tear film a hypothesis on the consequences of this gradient on the rheological properties of the tear film is provided. The mucoadhesive properties of HA and their dependence on chain length are explained. The ability of HA to bind to receptors on the ocular epithelial cells, and in particular the potential consequences of the interaction between HA and the receptor HARE, responsible for HA endocytosis by corneal epithelial cells is discussed. The physiological function of HA in the framework of ocular surface homeostasis and wound healing are outlined, and the influence of the chain length of HA on the clinical performance of HA eye drops is illustrated. The use of very high molecular weight HA (hylan A) eye drops as drug vehicle for the next generation of ophthalmic drugs with minimized side effects is proposed and its advantages elucidated. Consequences of the diagnosis and treatment of ocular surface disease are discussed.

The effect of a nanofiber-hydrogel composite on neural tissue repair and regeneration in the contused spinal cord

An injury to the spinal cord causes long-lasting loss of nervous tissue because endogenous nervous tissue repair and regeneration at the site of injury is limited. We engineered an injectable nanofiber-hydrogel composite (NHC) with interfacial bonding to provide mechanical strength and porosity and examined its effect on repair and neural tissue regeneration in an adult rat model of spinal cord contusion. At 28 days after treatment with NHC, the width of the contused spinal cord segment was 2-fold larger than in controls. With NHC treatment, tissue in the injury had a 2-fold higher M2/M1 macrophage ratio, 5-fold higher blood vessel density, 2.6-fold higher immature neuron presence, 2.4-fold higher axon density, and a similar glial scar presence compared with controls. Spared nervous tissue volume in the contused segment and hind limb function was similar between groups. Our findings indicated that NHC provided mechanical support to the contused spinal cord and supported pro-regenerative macrophage polarization, angiogenesis, axon growth, and neurogenesis in the injured tissue without any exogenous factors or cells. These results motivate further optimization of the NHC and delivery protocol to fully translate the potential of the unique properties of the NHC for treating spinal cord injury.

Effect of phenolic compounds from the leaves of Psidium guajava on the activity of three metabolism-related enzymes

Enzyme activity modulation by synthetic compounds provide strategies combining the inhibitory and therapeutic mode of action of the confirmed inhibitors. However, natural modulators could offer a valuable alternative for synthetic ones for the treatment of different chronic diseases (diabetes, hypertension, cancer); due to the numerous side effects of the latter. In vitro screening assays were conducted for Psidium guajava leaf methanolic extract against three metabolism-related enzymes; α-amylase, tyrosinase, and hyaluronidase. The obtained results showed that the examined extract retained weak and moderate multitarget inhibition against α-amylase, tyrosinase, and hyaluronidase, respectively; however, the leaf fractions exhibited stronger inhibitions for the three investigated enzymes. Fractionation of P. guajava leaf extract revealed that anthraquinones and ellagic acid are of the major active compounds with inhibitory activities for α-amylase, tyrosinase, and hyaluronidase. Kinetic studies showed that quinalizarin inhibition is competitive for both α-amylase and hyaluronidase, and ellagic acid inhibition for tyrosinase and hyaluronidase is competitive and un-competitive, respectively. The molecular docking studies of quinalizarin and ellagic acid with α-amylase, tyrosinase, and hyaluronidase showed high binding energies with different bonds stabilizing the ligand-protein complex. Compiling all obtained results led to conclude that both P. guajava leaf fractions, quinalizarin and ellagic acid, have multitarget activities with potential therapeutic applications in many metabolic disorders.

Human-Derived Scaffold Components and Stem Cells Creating Immunocompatible Dermal Tissue Ensuing Regulated Nonfibrotic Cellular Phenotypes

Regeneration of large-sized acute and chronic wounds provoked by severe burns and diabetes is a major concern worldwide. The availability of immunocompatible matrix with a wide range of regenerative medical applications, more specifically, for nonhealing chronic wounds is an unmet clinical need. Extrapolating the in vitro tissue engineering knowledge for in vivo guided wound regeneration could be a meaningful approach. This study aimed to develop a completely human-derived and minimally immune-responsive scaffold comprising of acellular amniotic membrane (AM), fibrin (FIB) and hyaluronic acid (HA), termed AMFIBHA. The potential for in vivo guidance of skin regeneration was validated through in vitro dermal tissue assembly on the combination scaffold by growing human fibroblasts, differentiated from human adipose tissue-derived mesenchymal stem cells (hADMSCs). An effective method was standardized for obtaining decellularized amnion (dAM) for assuring better immuno-compatibility. The biochemical stability of dAM upon plasma sterilization (pdAM) confirms its suitability for both in vitro and in vivo tissue engineering. The problem of poor handling characteristics was solved by combining the dried dAM with fibrin derived from a clinically used fibrin sealant kit. An additional constituent HA, derived from human umbilical cord tissue, imparts the required water absorption and retention property for better cell migration and growth. Post sterilization, the combination scaffold AMFIBHA demonstrated hemo-/cytocompatibility, confirming the absence of detergent residuals. Upon long-term (20 days/40 days) culture of hADMSC-derived fibroblasts, the suppleness of generated tissue was established by demonstrating regulated deposition of collagen, elastin, and glycosaminoglycans using both qualitative and quantitative measurements. Regulated expressions of transforming growth factors-beta 1 (TGF-β1) & TGF-β3, alpha smooth muscle actin (α-SMA), fibrillin-1, collagen subtypes, and elastin suggest non-fibrotic fibroblast phenotype, which could be an effect of microenvironment endowed by the AM, FIB, and HA. In burn wound model experiments, immune response to cellular AM was prominent as compared to untreated/sham control wounds and decellularized AM-treated and AMFIBHA-treated wounds, ensuring biocompatibility. Wound regeneration with complete epithelialization, angiogenesis, development of rete pegs, and other skin appendages were clearly visualized in 28 days after treating large-sized (4 × 4 cm²), debrided, full-thickness third-degree burn wounds, indicating guided wound regeneration potential of AMFIBHA dermal substitute.

Implication of HYBID (Hyaluronan-Binding Protein Involved in Hyaluronan Depolymerization) in Hyaluronan Degradation by Synovial Fibroblasts in Patients with Knee Osteoarthritis

Cell migration-inducing hyaluronidase 1 (CEMIP), also known as hyaluronan (HA)-binding protein involved in HA depolymerization (HYBID), plays a role in HA degradation. CEMIP2, also known as transmembrane protein 2 (TMEM2), possessing a sequence similarity with HYBID, is reported as a hyaluronidase in mice. However, the expression of these molecules in osteoarthritic synovium and their involvement in HA degradation in synovial fluid (SF) from patients with knee osteoarthritis remain elusive. This study examined their expression in synovial tissue and the relationship with molecular weight of HA in SF in knee osteoarthritis patients. Quantification of mRNA demonstrated that HYBID expression is significantly (5.5-fold) higher in osteoarthritic synovium than in normal control synovium, whereas TMEM2 expression level is similar between the two groups. By immunohistochemistry, HYBID was localized mainly to CD68-negative and fibroblast-specific protein 1-positive synovial lining cells and sublining fibroblasts in osteoarthritic synovium. The mRNA expression levels of HYBID, but not TMEM2, in osteoarthritic synovium positively correlated with distribution of lower-molecular-weight HA with below 1000 kDa in SF. HA-degrading activity in osteoarthritic synovial fibroblasts was abrogated by siRNA-mediated knockdown of HYBID. Among the 12 factors examined, IL-6 significantly up-regulated the HYBID expression and HA-degrading activity in osteoarthritic synovial fibroblasts. These data suggest that HYBID overexpressed by IL-6-stimulated synovial fibroblasts is implicated in HA degradation in osteoarthritic synovium.

Canine umbilical cord perivascular tissue: A source of stem cells for therapy and research

There are numerous sources of multipotent mesenchymal stromal cells (MSC) with therapeutic potential, and bone marrow is the main one. However, pain, lack of donors and comorbidities associated with harvesting stimulate the search for new sources of MSCs. The aim of this work is to obtain cells from umbilical cord (UC) perivascular tissue of dogs and characterize them as MSCs. For this, the UC was obtained from therapeutic cesarean sections and submitted to enzymatic digestion. The obtained cells were subjected to growth and proliferation tests, as well as the analysis of surface markers, differentiation test in three mesenchymal lineages and analysis of differentiation markers expression. From all the UC used in this study an adherent with fibroblastoid shape cell was obtained, with an initial number of 4.8 × 10⁵ of cells. The growth curves showed a lag phase from 0 to 24 h, followed by a phase of growth of 24 to 168 h, and then phase of cell decay. The doubling time was kept around 15 h until the sixth passage, from which there were signs of cellular senescence. The differentiation assays demonstrated the ability of cells to differentiate into osteoblasts, adipocytes and chondrocytes when subjected to the induction mediums. The study of surface markers was positive for adhesion markers and negative for hematopoietic markers. Thus, cells obtained from canine UC perivascular tissue by enzymatic digestion are multipotent MSC and the protocol developed ensures the perivascular origin of these cells.

Endothelial Glycocalyx Impairment in Disease: Focus on Hyaluronan Shedding

Hyaluronan (HA) is a ubiquitous glycosaminoglycan of the extracellular matrix. It is present in the endothelial glycocalyx covering the apical surface of endothelial cells. The endothelial glycocalyx regulates blood vessel permeability and homeostasis. HA plays a central role in numerous functions of the endothelial surface layer, protecting the endothelial cells, regulating the barrier permeability, and ensuring mechanosensing, which is essential to nitric oxide production and flow-induced vasodilation. During acute injury, inflammatory conditions, or many other pathologic conditions, the endothelial glycocalyx is damaged, and its degradation is accompanied by shedding of one or more glycocalyx components into the blood. Syndecan-1, heparan sulfate, and HA are the main components whose shedding has been claimed to represent the endothelial glycocalyx state of health. This review focuses on endothelial glycocalyx HA and highlights its key roles in the functions of the endothelial glycocalyx, its shedding in several pathologic conditions such as sepsis, diabetes, chronic and acute kidney injury, ischemia/reperfusion, atherosclerosis, and inflammation, which are all accompanied by increased circulating HA levels. Plasma/serum HA level is becoming recognized as a biomarker of endothelial glycocalyx damage in select pathologies. Hyaluronidase, the main HA-degrading enzyme, and its involvement in the impairment of endothelial glycocalyx are also addressed.

Effect of phenolic compounds from the rind of Punica granatum on the activity of three metabolism-related enzymes

Enzyme activity modulation by synthetic compounds provide strategies combining the inhibitory and therapeutic mode of action of the confirmed inhibitors. However, natural modulators could offer a valuable alternative for synthetic ones for the treatment of different chronic diseases (diabetes, hypertension, cancer) due to the numerous side effects of the latter. In vitro screening assays were conducted for Punica granatum rind methanolic extract against three metabolism-related enzymes: α-amylase, tyrosinase, and hyaluronidase. The obtained results showed that the examined extract retained high multitarget inhibition with inhibition percentages 31.5 ± 1.3%, 75.9 ± 4.7%, and 68.5 ± 5.3% against α-amylase, tyrosinase, and hyaluronidase, respectively. Bioguided fractionation of P. granatum rind extract revealed that quercetin is the major active compound with inhibitory activities: 54.3 ± 2.7%, 94.2 ± 3.5%, and 90.9 ± 2.7% against α-amylase, tyrosinase, and hyaluronidase, respectively. Kinetic studies of enzymes showed that quercetin inhibition was noncompetitive, uncompetitive, and competitive for α-amylase, tyrosinase, and hyaluronidase, respectively. The molecular docking of quercetin with α-amylase and hyaluronidase showed high binding energy with different bonds stabilizing the ligand-protein complex. Compiling all obtained results led to conclude that both P. granatum rind extract and quercetin have multitarget activities with potential therapeutic applications in many metabolic disorders.

HYBID (alias KIAA1199/CEMIP) and hyaluronan synthase coordinately regulate hyaluronan metabolism in histamine-stimulated skin fibroblasts

The immune-regulatory compound histamine is involved in the metabolism of the essential skin component hyaluronan (HA). We previously reported that histamine up-regulates the expression of HYBID (hyaluronan-binding protein involved in hyaluronan depolymerization, also called CEMIP or KIAA1199), which plays a key role in HA degradation. However, no information is available about histamine's effects on HA synthase (HAS) expression, the molecular sizes of HA species produced, and histamine receptors and their signaling pathways in skin fibroblasts. Moreover, histamine's effects on photoaged skin remain elusive. Here, we show that histamine increases HA degradation by up-regulating HYBID and down-regulating HAS2 in human skin fibroblasts in a dose- and time-dependent manner and thereby decreases the total amounts and sizes of newly produced HA. Histamine H1 blocker abrogated the histamine effects on HYBID up-regulation, HAS2 suppression, and HA degradation. Histamine H1 agonist exhibited effects on HA levels, composition, and breakdown similar to those of histamine. Of note, blockade of protein kinase Cδ or PI3K-Akt signaling abolished histamine-mediated HYBID stimulation and HAS2 suppression, respectively. Immunohistochemical experiments revealed a significant ∼2-fold increase in tryptase-positive mast cells in photoaged skin, where HYBID and HAS2 expression levels were increased and decreased, respectively, compared with photoprotected skin. These results indicate that histamine controls HA metabolism by up-regulating HYBID and down-regulating HAS2 via distinct signaling pathways downstream of histamine receptor H1. They further suggest that histamine may contribute to photoaged skin damage by skewing HA metabolism toward degradation.

Hyaluronic acid, Manuka honey and Acemannan gel: Wound-specific applications for skin lesions

Healing of open wounds is of great medical importance. Wound healing is a complex process that aims to restore the function and structure of damaged tissue. This study was conducted to compare secondary intention healing of wounds treated daily with a topical application of commercially available hyaluronic acid (HA), Manuka honey (MH), Acemannan gel (AG), or a placebo. Bilateral wounds were surgically created on the backs of six sheep. At two and six weeks post-wound creation, biopsies were obtained to perform histological, immunohistochemical, and molecular analyses of the wound site. Daily clinical evaluations were performed and weekly photographs were taken of the wounds. HA treatment promoted a physiological progression of the healing process in all wound healing phases, while stimulating an abundant cutaneous adnexa and promoting rapid healing, representing the most compelling treatment. MH-treated wounds were slightly dry. However, the main effect of MH was to promote cell proliferation and neovascularization, with an overall pro-inflammatory effect. Results suggest that MH treatment enhances the healing process. AG treatment dehydrated the wounds and stimulated late granulation tissue and cell proliferation. Moreover, AG-treated wounds produced a mild late pro-inflammatory and neovascularization effect. Our data indicate that AG treatment can have a positive influence on moist wounds with abundant granulation tissue and exudate.

The matrix of SDS integrated with linear hydrophilic polymer for resolution of high- and low-molecular weight hyaluronic acids in MEKC

Hyaluronic acid (HA), a multi-functional material, has a high dispersion in molecular weight, and the functions of HA are determined through the size. Nevertheless, hyaluronic acid mixtures are not easily separated due to their polydispersity. In this study, a capillary electrophoresis strategy was developed for resolution of different molecular-weight HA without enzymatic digestion. Here, hyaluronic acid mixtures with low molecular weight (380 kD; LHA) and high molecular weight (2180 kD; HHA) were successfully resolved by the SDS integrated with low molecular-weight polymer in capillary electrophoresis. By optimizing experimental conditions, the separation of LHA and HHA was completed within 14 min. The optimal conditions were as follows: the running buffer was 25 mM borate buffer (pH 9.75) containing 30 mM SDS and 10% polyethylene glycol (MW: 8000); applied voltage was 20 kV (detector at cathode side) and separation temperature was set at 25 °C. The data of method validation showed that calibration plots were linear (r ≥ 0.9977) over a range of 10-50 μg/mL for LHA, and 40-200 μg/mL for HHA. In the evaluation of precision and accuracy for this method, the RSD and RE values were all less than 4.2%. This fascinating technique was successfully applied to the quality control of cosmetic and pharmaceutical containing different ratios of LHA and HHA, and it was feasible for serving as a tool to quantitatively analyze different sizes of HA for clinical survey.

Roles of hyaluronan in cardiovascular and nervous system disorders

Hyaluronan is a widely occurring extracellular matrix molecule, which is not only a supporting structural component, but also an active regulator of cellular functions. The chemophysical and biological properties of hyaluronan are greatly affected by its molecular size and several hyaluronan-binding proteins, making hyaluronan a fascinating molecule with great functional diversity. This review summarizes our current understanding of the roles of hyaluronan in cardiovascular and nervous system disorders, such as atherosclerosis, myocardial infarction, and stroke, with the aim to provide a foundation for future research and clinical trials.

Expression and activity of hyaluronidases HYAL-1, HYAL-2 and HYAL-3 in the human intervertebral disc

PURPOSE

Hyaluronic acid plays an essential role in water retention of the intervertebral disc (IVD) and thus provides flexibility and shock absorbance in the spine. Hyaluronic acid gets degraded by hyaluronidases (HYALs), and some of the resulting fragments were previously shown to induce an inflammatory and catabolic response in human IVD cells. However, no data currently exist on the expression and activity of HYALs in IVD health and disease.

METHODS

Gene expression, protein expression and activity of HYALs were determined in human IVD biopsies with different degrees of degeneration (n = 50 total). Furthermore, freshly isolated human IVD cells (n = 23 total) were stimulated with IL-1β, TNF-α or H₂O₂, followed by analysis of HYAL-1, HYAL-2 and HYAL-3 gene expression.

RESULTS

Gene expression of HYAL-1 and protein expression of HYAL-2 significantly increased in moderate/severe disc samples when compared to samples with no or low IVD degeneration. HYAL activity was not significantly increased due to high donor-donor variation, but seemed overall higher in the moderate/severe group. An inflammatory environment, as seen during IVD disease, did not affect HYAL-1, HYAL-2 or HYAL-3 expression, whereas exposure to oxidative stress (100 µM H₂O₂) upregulated HYAL-2 expression relative to untreated controls.

CONCLUSION

Although HYAL-1, HYAL-2 and HYAL-3 are all expressed in the IVD, HYAL-2 seems to have the highest pathophysiological relevance. Nonetheless, further studies will be needed to comprehensively elucidate its significance and to determine its potential as a therapeutic target. These slides can be retrieved under Electronic Supplementary Material.

Role of HYBID (Hyaluronan Binding Protein Involved in Hyaluronan Depolymerization), Alias KIAA1199/CEMIP, in Hyaluronan Degradation in Normal and Photoaged Skin

Photoaged skin is characterized clinically by apparent manifestations such as wrinkles and sagging, and histologically by an accumulation of abnormal elastin and a severe loss of collagen fibers in the dermis. Quantitative and qualitative alterations in elastin and collagens are considered to be responsible for the formation of wrinkles and sagging. However, since the integrity of elastin and collagen fibers in the dermis is maintained by their interactions with hyaluronan (HA) and a proteoglycan network structure, HA degradation may be the initial process, prior to the breakdown of the fibrillary components, leading to wrinkles and sagging in photoaged skin. We have recently discovered a new HA-degrading mechanism mediated by HYBID (hyaluronan binding protein involved in hyaluronan depolymerization), alias KIAA1199/CEMIP, in human skin fibroblasts, and examined the implication of HYBID for skin photoaging. In this review, we give an overview of the characteristics of HYBID and its prospective roles in HA turnover in normal skin and excessive HA degradation in photoaged skin. In addition, we describe our data on the inhibition of HYBID activity and expression by plant extracts in skin fibroblasts; and propose novel strategies to prevent or improve photoaging symptoms, such as skin wrinkling, by inhibition of HYBID-mediated HA degradation.

Involvement of hyaluronan and CD44 in cancer and viral infections

Hyaluronan and its major receptor CD44 are ubiquitously distributed. They have important structural as well as signaling roles, regulating tissue homeostasis, and their expression levels are tightly regulated. In addition to signaling initiated by the interaction of the intracellular domain of CD44 with cytoplasmic signaling molecules, CD44 has important roles as a co-receptor for different types of receptors of growth factors and cytokines. Dysregulation of hyaluronan-CD44 interactions is seen in diseases, such as inflammation and cancer. In the present communication, we discuss the mechanism of hyaluronan-induced signaling via CD44, as well as the involvement of hyaluronan-engaged CD44 in malignancies and in viral infections.

Using cross-linked hyaluronic acid gel to prevent postoperative lumbar epidural space adhesion: in vitro and in vivo studies

PURPOSE

Hyaluronic acid prevents tissue adhesion after different surgeries. Physical barriers and inflammatory regulation have been suggested to be involved in the mechanism of these clinical effects. However, the molecular mechanism by which hyaluronic acid prevents epidural adhesion has not yet been reported.

METHODS

In the current in vivo studies, we investigated cross-linked hyaluronic acid gel in the regulation of scar gene expression, the accumulation of fibroblasts in scar tissue, and the prevention of epidural adhesion. The effect of cross-linked hyaluronic acid gel on the secretion of inflammatory factors was observed in vitro. In addition, to ensure the accuracy and reliability of the in vivo gene expression results, we used a cell model to detect the target genes in vitro.

RESULTS

The expression levels of TGFβ1 and COL1A1 mRNA were decreased in the cross-linked hyaluronic acid gel-treated group, and the protein expression of levels TGFβ1 and COL1A1 were also reduced, as detected by Western blotting in vitro and in vivo (P < 0.05). Histomorphometry results demonstrated that the number of fibroblasts in the experimental group was significantly lower than that in the control group 2 weeks postoperatively. Micro-CT scans showed that the cross-linked hyaluronic acid gel could reduce adhesion in the epidural space after laminectomy. Additionally, the cross-linked hyaluronic acid gel could inhibit IL-6 secretion.

CONCLUSIONS

These results indicate that cross-linked hyaluronic acid gel can prevent epidural adhesion by inhibiting inflammatory factors, such as IL-6, and downregulating TGFβ1 and COL1A1 mRNA expression. These slides can be retrieved under Electronic Supplementary Material.

Topical hyaluronan alone promotes corneal epithelial cell migration whereas combination with benzalkonium chloride impairs epithelial wound healing

Purpose: To evaluate the effects of topical hyaluronan (HA) on corneal epithelial wound healing when administered with or without benzalkonium chloride (BAC).Methods: A cultured human corneal epithelial cell line (HCE-T) was subjected to in vitro scratch assays and in situ epithelial migration was evaluated in organ-cultured rabbit corneas. The corneal epithelium of C57BL/6J mice was also evaluated to determine in vivo wound healing. An in vivo imaging system was also used to evaluate the effects of HA on eye drop retention on the ocular surface.Results: The findings revealed the promotion of HCE-T migration, in situ rabbit corneal epithelial migration, and in vivo wound healing in mouse corneal epithelium by HA. Pre-treatment with HA also protected against delayed epithelial wound healing in BAC in vitro. However, pre-treatment with 3 mg/mL HA did not show a protective effect against BAC in vivo, but instead delayed epithelial wound healing and increased detection of cleaved caspase-3. This suggested that HA promotes the retention of BAC on the ocular surface. The instilled HA was retained after 15 min, at a significantly higher rate than for phosphate-buffered saline.Conclusions: The combination of HA and BAC impaired wound healing in the corneal epithelium.

High levels of serum hyaluronan is an early predictor of dengue warning signs and perturbs vascular integrity

BACKGROUND

A main pathological feature of severe dengue virus infection is endothelial hyper-permeability. The dengue virus nonstructural protein 1 (NS1) has been implicated in the vascular leakage that characterizes severe dengue virus infection, however, the molecular mechanisms involved are not known.

METHODS

A cohort of 250 dengue patients has been followed from the onset of symptoms to the recovery phase. Serum hyaluronan levels and several other clinical parameters were recorded. The effect of NS1 treatment of cultured fibroblasts and endothelial cells on the expressions of hyaluronan synthetic and catabolic enzymes and the hyaluronan receptor CD44, were determined, as have the effects on the formation of hyaluronan-rich matrices and endothelial permeability.

FINDINGS

Elevated serum hyaluronan levels (≥70 ng/ml) during early infection was found to be an independent predictor for occurrence of warning signs, and thus severe dengue fever. High circulating levels of the viral protein NS1, indicative of disease severity, correlated with high concentrations of serum hyaluronan. NS1 exposure decreased the expression of CD44 in differentiating endothelial cells impairing the integrity of vessel-like structures, and promoted the synthesis of hyaluronan in dermal fibroblasts and endothelial cells in synergy with dengue-induced pro-inflammatory mediators. Deposited hyaluronan-rich matrices around cells cultured in vitro recruited CD44-expressing macrophage-like cells, suggesting a mechanism for enhancement of inflammation. In cultured endothelial cells, perturbed hyaluronan-CD44 interactions enhanced endothelial permeability through modulation of VE-cadherin and cytoskeleton re-organization, and exacerbated the NS1-induced disruption of endothelial integrity.

INTERPRETATION

Pharmacological targeting of hyaluronan biosynthesis and/or its CD44-mediated signaling may limit the life-threatening vascular leakiness during moderate-to-severe dengue virus infection. FUND: This work was supported in part by grants from the Swedish Cancer Society (2018/337; 2016/445), the Swedish Research Council (2015-02757), the Ludwig Institute for Cancer Research, Uppsala University, the Ministry of Science and Technology, Taiwan (106-2314-B-037-088- and 106-2915-I-037-501-), Kaohsiung Medical University Hospital (KMUH103-3 T05) and Academy of Finland. The funders played no role in the design, interpretation or writing of the manuscript.

3D Bioprinting of the Sustained Drug Release Wound Dressing with Double-Crosslinked Hyaluronic-Acid-Based Hydrogels

Hyaluronic acid (HA)-based hydrogels are widely used in biomedical applications due to their excellent biocompatibility. HA can be Ultraviolet (UV)-crosslinked by modification with methacrylic anhydride (HA-MA) and crosslinked by modification with 3,3'-dithiobis(propionylhydrazide) (DTP) (HA-SH) via click reaction. In the study presented in this paper, a 3D-bioprinted, double-crosslinked, hyaluronic-acid-based hydrogel for wound dressing was proposed. The hydrogel was produced by mixing HA-MA and HA-SH at different weight ratios. The rheological test showed that the storage modulus (G') of the HA-SH/HA-MA hydrogel increased with the increase in the HA-MA content. The hydrogel had a high swelling ratio and a high controlled degradation rate. The in vitro degradation test showed that the hydrogel at the HA-SH/HA-MA ratio of 9:1 (S9M1) degraded by 89.91% ± 2.26% at 11 days. The rheological performance, drug release profile and the cytocompatibility of HA-SH/HA-MA hydrogels with loaded Nafcillin, which is an antibacterial drug, were evaluated. The wound dressing function of this hydrogel was evaluated by Live/Dead staining and CCK-8 assays. The foregoing results imply that the proposed HA-SH/HA-MA hydrogel has promise in wound repair applications.

Proteomic Analysis of Vocal Fold Fibroblasts Exposed to Cigarette Smoke Extract: Exploring the Pathophysiology of Reinke's Edema

Reinke's edema is a smoking-associated, benign, mostly bilateral lesion of the vocal folds leading to difficulties in breathing and voice problems. Pronounced histological changes such as damaged microvessels or immune cell infiltration have been described in the vocal fold connective tissue, the lamina propria Thus, vocal fold fibroblasts, the main cell type of the lamina propria, have been postulated to play a critical role in disease mediation. Yet information about the pathophysiology is still scarce and treatment is only surgical, i.e. symptomatic. To explore the pathophysiology of Reinke's edema, we exposed near-primary human vocal fold fibroblasts to medium conditioned with cigarette smoke extract for 24 h as well as 4 days followed by quantitative mass spectrometry.Proteomic analyses after 24 h revealed that cigarette smoke increased proteins previously described to be involved in oxidative stress responses in other contexts. Correspondingly, gene sets linked to metabolism of xenobiotics and reactive oxygen species were significantly enriched among cigarette smoke-induced proteins. Among the proteins most downregulated by cigarette smoke, we identified fibrillar collagens COL1A1 and COL1A2; this reduction was validated by complementary methods. Further, we found a significant increase of UDP-glucose 6-dehydrogenase, generating a building block for biosynthesis of hyaluronan, another crucial component of the vocal fold lamina propria In line with this result, hyaluronan levels were significantly increased because of cigarette smoke exposure. Long term treatment of 4 days did not lead to significant changes.The current findings corroborate previous studies but also reveal new insights in possible disease mechanisms of Reinke's edema. We postulate that changes in the composition of the vocal folds' extracellular matrix -reduction of collagen fibrils, increase of hyaluronan- may lead to the clinical findings. This might ease the identification of better, disease-specific treatment options.

Improving in vitro biocompatibility on biomimetic mineralized collagen bone materials modified with hyaluronic acid oligosaccharide

Hyaluronic acid (HA) has great potential in bone tissue engineering due to its favorable bioactivity and biocompatibility, especially hyaluronic acid oligosaccharides (oHAs) shows a promising result in endothelialization of blood vessel. To improve endothelialized effect and osteogenic performance of bone scaffold, we have created a biomimetic nanofiber network based on collagen modified with hyaluronic acid oligosaccharides (Col/oHAs) and its mineralized product. Biomimetically mineralized Col/oHAs based composite (Col/oHAs/HAP) was prepared via self-assembly at room temperature. The resultant composites were characterized by fourier transform infrared spectroscopy (FT-IR), X-Ray diffractometry (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). They show some characteristics of natural bone both in composition and microstructure. The nanofiber was fabricated as a hybrid network which bionics extracellular matrix (ECM) and was prepared to culture artery endothelial cell (PIEC) and the mouse parietal bone cell (MC3T3-E1). Cells attached tightly to the nanofibers and infiltrated into the materials, forming an interconnected cell community. Moreover, the as-prepared nanofiber was found to noticeably enhance cells adhesion and proliferation and upregulate alkaline phosphatase activity (ALP) and osteocalcin (OCN) expression suggesting positive cellular responses. These results indicated that the Col/oHAs/HAP composite has a promising capacity to direct the osteogenic differentiation by providing an adaptable environment and can be expected as an excellent candidate for bone tissue engineering approaches with improved performance of promoting PIEC proliferation.

Induction of Hyalurosome by Topical Hyaluronate Fragments Results in Superficial Filling of the Skin Complementary to Hyaluronate Filler Injections

Hyaluronate (HA) plays a major role in the process of skin aging. The main use of HA has been for hydration and dermal fillers. Another approach, based on the discovery of the signaling effects of topically applied hyaluronate fragments (HAF), has subsequently been developed. It has been thoroughly demonstrated that topical applications of HAF of a very specific size induce HA filling of the epidermis and the upper dermis. These effects are particularly visible in dermatoporotic patients. Moreover, the combination of HA-based filler injections with topical applications of HAFs/retinoids showed an optimization of the effects of HA. Thus, a new classification of the different effects of HA is proposed here.

Hyaluronic Acid: Molecular Mechanisms and Therapeutic Trajectory

Hyaluronic acid (also known as hyaluronan or hyaluronate) is naturally found in many tissues and fluids, but more abundantly in articular cartilage and synovial fluid (SF). Hyaluronic acid (HA) content varies widely in different joints and species. HA is a non-sulfated, naturally occurring non-protein glycosaminoglycan (GAG), with distinct physico-chemical properties, produced by synoviocytes, fibroblasts, and chondrocytes. HA has an important role in the biomechanics of normal SF, where it is partially responsible for lubrication and viscoelasticity of the SF. The concentration of HA and its molecular weight (MW) decline as osteoarthritis (OA) progresses with aging. For that reason, HA has been used for more than four decades in the treatment of OA in dogs, horses and humans. HA produces anti-arthritic effects via multiple mechanisms involving receptors, enzymes and other metabolic pathways. HA is also used in the treatment of ophthalmic, dermal, burns, wound repair, and other health conditions. The MW of HA appears to play a critical role in the formulation of the products used in the treatment of diseases. This review provides a mechanism-based rationale for the use of HA in some disease conditions with special reference to OA.

pH-responsive calcium alginate hydrogel laden with protamine nanoparticles and hyaluronan oligosaccharide promotes diabetic wound healing by enhancing angiogenesis and antibacterial activity

Diabetic wounds as chronic wounds represent a severe, persistent complication of diabetes and, in the most extreme cases, can lead to amputation. Two critical and unfavorable factors affecting diabetic wound healing are sustained bacterial-induced chronic inflammation and disrupted vascularization. In this paper, we presented a novel, pH-responsive calcium alginate hydrogel laden with protamine nanoparticles and hyaluronan oligosaccharides, and explored its potential for accelerating diabetic wound healing. A thorough investigation indicated that the drug- and nanoparticle-loaded hydrogel demonstrated strong bactericidal behavior mediated by protamine nanoparticles and reduced bacterial-induced chronic inflammation at the wound site. Furthermore, it accelerated the wound-healing process by promoting angiogenesis in skin wounds with the hyaluronan oligosaccharide-mediated enhanced expression of vascular endothelial growth factor.

Re-epithelialization of adult skin wounds: Cellular mechanisms and therapeutic strategies

Cutaneous wound healing in adult mammals is a complex multi-step process involving overlapping stages of blood clot formation, inflammation, re-epithelialization, granulation tissue formation, neovascularization, and remodelling. Re-epithelialization describes the resurfacing of a wound with new epithelium. The cellular and molecular processes involved in the initiation, maintenance, and completion of epithelialization are essential for successful wound closure. A variety of modulators are involved, including growth factors, cytokines, matrix metalloproteinases, cellular receptors, and extracellular matrix components. Here, we focus on cellular mechanisms underlying keratinocyte migration and proliferation during epidermal closure. Inability to re-epithelialize is a clear indicator of chronic non-healing wounds, which fail to proceed through the normal phases of wound healing in an orderly and timely manner. This review summarizes the current knowledge regarding the management and treatment of acute and chronic wounds, with a focus on re-epithelialization, offering some insights into novel future therapies.

Colorectal cancer-associated ~ 6 kDa hyaluronan serves as a novel biomarker for cancer progression and metastasis

Low molecular weight hyaluronan (LMW-HA) is believed to accumulate in tumors and to exert protumor effects. This study aimed to identify colorectal cancer (CRC)-associated LMW-HA, precisely determine its MW, and elucidate its role in predicting tumor progression. The MW distribution of HA extracted from CRC and paired noncancerous tissues was evaluated. We found that the level of HA with a MW below 30 kDa was markedly elevated in CRC tissues, and we defined HA with a MW of ~ 6 kDa as CRC-associated LMW-HA. In line with this finding, ~ 6 kDa HA was significantly accumulated in cancer tissues relative to total HA, and this LMW-HA played a critical role in tumor metastasis. Moreover, serum ~ 6 kDa HA levels in CRC patients were significantly increased and positively correlated with the levels in matched cancer tissues. Elevated serum ~ 6 kDa HA levels could be used to discriminate patients with or without CRC and was associated with early relapse, advanced tumor-node-metastasis stage, lymphovascular invasion, and lymph node (LN) metastasis. Notably, serum ~ 6 kDa HA levels were significantly reduced after tumor resection. Our study suggests that ~ 6 kDa HA may serve as a new biomarker for estimating tumor progression, predicting LN metastasis, and monitoring tumor recurrence.

Structural Modifications and Solution Behavior of Hyaluronic Acid Degraded with High pH and Temperature

Hyaluronic acid (HA) is a macromolecule with valuable benefits over its range of molar masses (MM). Degradation studies are relevant to maintain the same purity level in biomedical studies when using HA of different MM. We degraded HA via high pH and temperature and evaluated its MM, solution behavior, and structure over time. After 24 h, low MM HA was predominant, and the MM decreased from 753 to 36.2 kDa. Dynamic light scattering (DLS) showed a decrease in the number of HA populations, and the solution tended to be less polydispersed. The zeta potential varied from - 10 to - 30 mV, close to the stable range. FTIR showed that the primary structure of HA was affected after only 48 h of reaction. These results are relevant for the production of low MM HA to be used or mixed with high MM HA, generating structured biomaterials for biomedical applications.

Combination of D-dimer and carcinoembryonic antigen levels as a predictive and prognostic biomarker in advanced colorectal cancer patients

In view of the controversial findings on the utility of D-dimer and carcinoembryonic antigen (CEA) as biomarkers in advanced colorectal cancer (CRC), we evaluated the predictive and prognostic value of the D-dimer and CEA levels in unresectable advanced CRC patients treated with first-line chemotherapy. A total of 57 previously untreated patients with advanced CRC were enrolled. We assessed both plasma D-dimer and CEA levels at the start (D1 and CEA1) and after two cycles (D2 and CEA2) of chemotherapy. Based on the respective optimal cut-off values of 0.8 and 5.0 ng/mL for D1 and CEA1, respectively, patients were divided into low and high D-dimer or CEA groups. The results show that D1 and CEA1 levels were correlated (r = 0.392, P = 0.003). Mean CEA2 was reduced by 26.24 ng/mL in patients with partial response and stable disease and increased by 165.95 ng/mL in patients with progressive disease relative to the CEA1 level (P < 0.001). However, no correlation was evident between changes in the D-dimer levels and chemotherapy response (P = 0.441). The overall survival (OS) of patients with high D1 was shorter than that of patients with low D1 (median OS, 16 vs 29 months, P = 0.009). Multivariate analyses further demonstrated that D1 (P = 0.042) and chemotherapy response (P = 0.016), but not CEA, were independent prognostic factors for OS in advanced CRC. Taken together, our result found that changes in CEA levels may serve as a predictive biomarker of the chemotherapy response and baseline D-dimer levels as a prognostic biomarker of OS in patients with advanced CRC.

Neodermis Formation in Full Thickness Wounds Using an Esterified Hyaluronic Acid Matrix

The role of the dermis is essential for the proper orchestration of all phases of the normal wound healing process. Wounds with seriously damaged or even absent dermis consistently show seriously impaired wound healing and/or long-term complications such as hypertrophic scarring. Replacing a damaged dermis requires a dermal matrix that is compatible with, or even stimulates, the process of wound healing. Hyaluronic acid (HA), in an esterified form, is among the many matrices that are available. HA has been used in a number of indications, such as ulcers (ie, diabetic foot ulcers and venous leg ulcers), trauma, including burns, and for the repair of contractures and hypertrophic scars. The shorter healing time and the decrease of recurring hypertrophy demonstrate the efficiency of HA-derived matrices. Biopsies, taken up to 12 months post-reconstruction show a neodermis that histologically is largely comparable to normal skin, which probably is a function of HA playing such a pivotal role in normal, unwounded skin, as well as in the process of healing.