CD44 and RHAMM Are Microenvironmental Sensors with Dual Metastasis Promoter and Suppressor Functions

The progression of primary tumors to metastases remains a significant roadblock to the treatment of most cancers. Emerging evidence has identified genes that specifically affect metastasis and are potential therapeutic targets for managing tumor progression. However, these genes can have dual tumor promoter and suppressor functions that are contextual in manifestation, and that complicate their development as targeted therapies. CD44 and RHAMM/HMMR are examples of multifunctional proteins that can either promote or suppress metastases, as demonstrated in experimental models. These two proteins can be viewed as microenvironmental sensors and this minireview addresses the known mechanistic underpinnings that may determine their metastasis suppressor versus promoter functions. Leveraging this mechanistic knowledge for CD44, RHAMM, and other multifunctional proteins is predicted to improve the precision of therapeutic targeting to achieve more effective management of metastasis.

Redistribution of the glycocalyx exposes phagocytic determinants on apoptotic cells

Phagocytes remove dead and dying cells by engaging "eat-me" ligands such as phosphatidylserine (PtdSer) on the surface of apoptotic targets. However, PtdSer is obscured by the bulky exofacial glycocalyx, which also exposes ligands that activate "don't-eat-me" receptors such as Siglecs. Clearly, unshielding the juxtamembrane "eat-me" ligands is required for the successful engulfment of apoptotic cells, but the mechanisms underlying this process have not been described. Using human and murine cells, we find that apoptosis-induced retraction and weakening of the cytoskeleton that anchors transmembrane proteins cause an inhomogeneous redistribution of the glycocalyx: actin-depleted blebs emerge, lacking the glycocalyx, while the rest of the apoptotic cell body retains sufficient actin to tether the glycocalyx in place. Thus, apoptotic blebs can be engaged by phagocytes and are targeted for engulfment. Therefore, in cells with an elaborate glycocalyx, such as mucinous cancer cells, this "don't-come-close-to-me" barrier must be removed to enable clearance by phagocytosis.

Nanotechnological Research for Regenerative Medicine: The Role of Hyaluronic Acid

Hyaluronic acid (HA) is a linear, anionic, non-sulfated glycosaminoglycan occurring in almost all body tissues and fluids of vertebrates including humans. It is a main component of the extracellular matrix and, thanks to its high water-holding capacity, plays a major role in tissue hydration and osmotic pressure maintenance, but it is also involved in cell proliferation, differentiation and migration, inflammation, immunomodulation, and angiogenesis. Based on multiple physiological effects on tissue repair and reconstruction processes, HA has found extensive application in regenerative medicine. In recent years, nanotechnological research has been applied to HA in order to improve its regenerative potential, developing nanomedical formulations containing HA as the main component of multifunctional hydrogels systems, or as core component or coating/functionalizing element of nanoconstructs. This review offers an overview of the various uses of HA in regenerative medicine aimed at designing innovative nanostructured devices to be applied in various fields such as orthopedics, dermatology, and neurology.

Myofascial junction: Emerging insights into the connection between deep/muscular fascia and muscle

Muscles and fasciae are mutually connected and are influenced by force transmission. However, the anatomical connectivity and histological features of these structures remain unclear. The aim of this study was to assess the evidence for connection between muscles and deep/muscular fasciae. We assessed this relationship in different topographical regions of human cadavers and in mice. The results showed that myofascial junctions (MFJ) were made up of collagen I immune-positive structures occupying an average area of 5.11 ± 0.81 μm2 , distributed in discrete regions at the interface between muscle and fascia with an average density of 9.7 ± 2.51 MFJ/mm and an average inclination angle of 35.25 ± 1.52°. These specialized structures also showed collagen III and HA immunopositivity and the presence of elastic fibers. The human myofascial junction can be visualized, opening emerging insights into the connection between deep/muscular fascia and muscle.

Hyaluronan and chondroitin sulfate in chicken-vegetable bone broth delay osteoporosis progression

Bone broth has recently gained worldwide recognition as a superfood that supplements several nutrients lacking in modern human diets; however, little is known of its efficacy on osteoporosis. Therefore, we aimed to identify the components of chicken-vegetable bone broth (CVBB) that are associated with osteoporosis prevention and verified the efficacy of these components using in vivo studies. In biochemical and cell biological experiments, CVBB was fractionated using ion exchange chromatography (IEC), and the effect of each IEC fraction on osteoclast differentiation was evaluated based on tartrate-resistant acid phosphatase (TRAP) activity, TRAP staining, and quantitative polymerase chain reaction analysis using mouse macrophage-like cells (RAW264 cell). In animal experiments, an ovariectomized (OVX) rat model was generated, followed by whole bone broth (OVX/CVBB) or IEC fraction (OVX/CVBB-Ext) administration and bone structural parameter characterization of OVX rat tibia based on micro-CT. Four CVBB fractions were obtained using IEC, and the fraction containing both hyaluronan and chondroitin sulfate (CVBB-Ext) led to the maximum inhibition of RAW264 cell differentiation. CVBB-Ext downregulated the expression of osteoclast differentiation marker genes. In animal experiments, the OVX group showed a clear decrease in bone density compared to that in the Sham operation group. The OVX/CVBB and OVX/CVBB-Ext groups showed increased bone mineral density and bone volume/tissue volume values compared to those in the OVX/control group. These results suggested that CVBB and CVBB-Ext slowed osteoporosis progression. Therefore, we conclude that hyaluronan and chondroitin sulfate in CVBB are key substances that impede osteoporosis progression. PRACTICAL APPLICATION: This study provides practical information on the effects of bone broth ingredients on osteoporosis to expand the current knowledge on the efficacy of bone broth, which is a widely consumed food. These results may help in the future development of bone broth as a dietary supplement for managing osteoporosis.

Developmental patterns of extracellular matrix molecules in the embryonic and postnatal mouse hindbrain

Normal brain development requires continuous communication between developing neurons and their environment filled by a complex network referred to as extracellular matrix (ECM). The ECM is divided into distinct families of molecules including hyaluronic acid, proteoglycans, glycoproteins such as tenascins, and link proteins. In this study, we characterize the temporal and spatial distribution of the extracellular matrix molecules in the embryonic and postnatal mouse hindbrain by using antibodies and lectin histochemistry. In the embryo, hyaluronan and neurocan were found in high amounts until the time of birth whereas versican and tenascin-R were detected in lower intensities during the whole embryonic period. After birth, both hyaluronic acid and neurocan still produced intense staining in almost all areas of the hindbrain, while tenascin-R labeling showed a continuous increase during postnatal development. The reaction with WFA and aggrecan was revealed first 4th postnatal day (P4) with low staining intensities, while HAPLN was detected two weeks after birth (P14). The perineuronal net appeared first around the facial and vestibular neurons at P4 with hyaluronic acid cytochemistry. One week after birth aggrecan, neurocan, tenascin-R, and WFA were also accumulated around the neurons located in several hindbrain nuclei, but HAPLN1 was detected on the second postnatal week. Our results provide further evidence that many extracellular macromolecules that will be incorporated into the perineuronal net are already expressed at embryonic and early postnatal stages of development to control differentiation, migration, and synaptogenesis of neurons. In late postnatal period, the experience-driven neuronal activity induces formation of perineuronal net to stabilize synaptic connections.

Hyaluronan deposition during COVID-19 - helpful or harmful?

Hyaluronan (HA), an extracellular matrix polysaccharide, is increased in the lungs during COVID-19 and correlates with severity. HA acts as an immune mediator that aids cell trafficking and intracellular signaling, but its role in COVID-19 is debated. Although HA is implicated in pulmonary viral disease pathogenesis, some studies suggest a potential protective function in COVID-19.

Matrix-Bound Hyaluronan Molecular Weight as a Regulator of Dendritic Cell Immune Potency

Hyaluronic acid (HA) is a glycosaminoglycan in the extracellular matrix with immunoregulatory properties depending on its molecular weight (MW). However, the impact of matrix-bound HA on dendritic cells (DCs) remains unclear due to varying distribution of HA MW under different physiological conditions. To investigate DCs in defined biosystems, 3D collagen matrices modified with HA of specific MW with similar microstructure and HA levels are used. It is found that HA MW influences cytokine binding to matrix, suggesting modulation of cytokine availability by the different HA MWs. These studies on DC immune potency reveal that low MW HA (8-15 kDa) enhances immature DC differentiation and antigen uptake, while medium (MMW-HA; 500-750 kDa) and high MW HA (HMW-HA; 1250-1500 kDa) increase cytokine secretion in mature DCs. The effect on DC phenotype and cytokine secretion by different MWs of HA is independent of CD44. However, blocking the CD44 receptor reveals its potential role in regulating acute inflammation through increased secretion of CCL2, CXCL8, and IL-6. Additionally, MMW- and HMW-HA matrices reduce migratory capacity of DCs, dependent on CD44. Overall, these findings provide insights into MW-dependent effects of matrix-bound HA on DCs, opening avenues for the design of DC-modulating materials to enhance DC-based therapy.

Hyaluronan-Sphingosine Polymersomes for Treatment of Ocular Neovascularization: Synthesis and Evaluation

Ocular neovascularization is a hallmark of several sight-threatening diseases, including diabetic retinopathy and age-related macular degeneration. Currently, available treatments are limited and often associated with side effects. Therefore, we present a novel approach to ocular neovascularization treatment through utilization of polymersomes from self-assembled sphingosine-grafted hyaluronic acid (HA-Sph) amphiphilic polymers. The polymersomes are generated in spherical morphologies and sizes between 97.95 nm - 161.9 nm with homogenous size distributions. Our experiments revealed that HA-Sph polymersomes, with concentrations ≥150 μg/mL, significantly inhibit the proliferation of HUVECs, while concurrently promoting the proliferation of retinal pigment epithelial cells. The polymersomes demonstrated gradual disintegration in vitro, leading to a sustained release of sphingosine, which prolonged the inhibition of HUVEC proliferation (from 87.5% at 24 h to 35.2% viability at 96 h). The efficacy of HA-Sph polymersomes in inhibiting angiogenesis was confirmed through tube formation assay, revealing a substantial reduction in total tube length compared to the control group. Our findings also validated the ocular penetration capability of polymersomes through an ex vivo whole porcine eye ocular penetration study, indicating their suitability for topical administration. Potentially, HA-Sph polymersomes can be harnessed to develop intricate drug delivery systems that protect the retina and effectively treat ocular diseases. This article is protected by copyright. All rights reserved.

Evaluation of Extracellular Matrix Remodeling in Full-thickness Skin Grafts in Mice

Abdominal hernia is a protruding weakness in the abdominal wall. It affects abdominal strength and life quality and can lead to complications due to intestinal entrapment. Autologous full-thickness skin graft (FTSG) has recently become an alternative material for reinforcement in the surgical repair of large abdominal hernias instead of synthetic mesh. FTSG eventually integrates with the abdominal wall, but the long-term fate of the graft itself is not fully understood. This has implications as to how these grafts should be optimally used and handled intraoperatively. This study investigates the remodeling of FTSG in either the onlay or the intraperitoneal position 8 weeks after FTSG transplantation in an experimental mouse model. There was a significant presence of fibroblasts, indicated by vimentin and S100A4 staining, but there were significant variations among animals as to how much of the graft had been remodeled into dense connective tissue. This correlated significantly with the proportion of vimentin-positive cells in the dense connective tissue. We also found that collagen hybridizing peptide staining intensity, a marker of active remodeling, was significantly associated with the proportion of S100A4-positive cells in the dense connective tissue of the FTSG.

Role of lymphatic endothelium specific hyaluronan receptor 1 in virus infection and associated diseases

Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) serves as a prominent marker for lymphatic endothelial cells (LECs) and is pivotal in the process of lymphangiogenesis, a critical factor in cancer development and metastasis. Overexpression of LYVE-1 has been observed in various cancers, where it is recognized as an adverse prognostic indicator. Targeting LYVE-1 has demonstrated inhibitory effects on tumor cell proliferation, migration, and the formation of lymph node metastases both in vitro and in vivo. While extensive research has focused on the role of LYVE-1 in cancer cells, its involvement in virus infection and associated diseases remains largely unexplored. This review consolidates recent findings regarding the expression of LYVE-1 and its functions in lymphangiogenesis during various viral infections and the development of related diseases, with a particular emphasis on Kaposi's sarcoma herpesvirus. Despite the limited available data, it is evident that further studies are essential to comprehensively understand the contribution of LYVE-1 to viral pathogenesis and oncogenesis.

Oral sodium hyaluronate relieves knee discomfort: A 12‑week double‑blinded, placebo‑controlled study

Sodium hyaluronate (SH) is a high molecular-weight polysaccharide composed of repeating polymeric disaccharides of D-glucuronic acid and N-acetyl-D-glucosamine. SH is present in every connective tissue and organ, with synovial fluid having the highest concentration of SH in the body. The effectiveness of oral SH on gonarthrosis is known; although, its influence on the knees of healthy individuals is not. However, as severe diseases may require surgery, it is better to take care of healthy knees before the onset of gonarthrosis. Therefore, the present study investigated the functionality of SH on the knee of healthy individuals. The present study was a randomized double-blind, placebo-controlled trial in which healthy adults (mean age: Placebo group, 61.50±1.59; SH group, 58.50±1.81), rated as grade ≤1 based on the Kellgren-Lawrence classification, were administered 111 mg/day SH for 12 weeks. The evaluation of visual analog scales were performed to assess the discomfort in the knees of the participants and were conducted at baseline, and then 6 and 12 weeks after the start of SH ingestion. Additionally, a locomotive syndrome risk test quantifying the mobility of the participants, a one-leg standing time with eyes open test evaluating the strength of the leg muscle as well as the ability to balance by measuring the time to stand on one leg and a blood test (interleukin-10, aspartate aminotransferase, alanine transaminase, γ-glutamyl transferase, lactate dehydrogenase, creatine kinase and C-reactive protein) were performed at baseline and then 12 weeks after the start of SH ingestion. A significant suppression of knee symptoms were demonstrated in the SH group compared with the placebo group in terms of the total visual analog scale scores for pain, stiffness and discomfort for the 31 healthy adult subjects. Significant suppression of symptoms was also demonstrated in the placebo group in terms of discomfort in the knees when descending stairs and pain in the knees after walking for a longer distance or duration than normal. No significant differences between the two groups were demonstrated in the locomotive syndrome risk test, one-leg standing time with eyes open test and the blood test. The results of the present study suggest the possibility that oral SH may help to maintain a healthy condition of the knees. The study protocol was registered with the University Hospital Medical Information Network Clinical Trial Registry in advance (registration no. UMIN000045980, November 4, 2021).

Differential Proteoglycan Expression in Atherosclerosis Alters Platelet Adhesion and Activation

Proteoglycans are differentially expressed in different atherosclerotic plaque phenotypes, with biglycan and decorin characteristic of ruptured plaques and versican and hyaluronan more prominent in eroded plaques. Following plaque disruption, the exposure of extracellular matrix (ECM) proteins triggers platelet adhesion and thrombus formation. In this study, the impact of differential plaque composition on platelet function and thrombus formation was investigated. Platelet adhesion, activation and thrombus formation under different shear stress conditions were assessed in response to individual proteoglycans and composites representing different plaque phenotypes. The results demonstrated that all the proteoglycans tested mediated platelet adhesion but not platelet activation, and the extent of adhesion observed was significantly lower than that observed with type I and type III collagens. Thrombus formation upon the rupture and erosion ECM composites was significantly reduced (p < 0.05) compared to relevant collagen alone, indicating that proteoglycans negatively regulate platelet collagen responses. This was supported by results demonstrating that the addition of soluble biglycan or decorin to whole blood markedly reduced thrombus formation on type I collagen (p < 0.05). Interestingly, thrombus formation upon the erosion composite displayed aspirin sensitivity, whereas the rupture composite was intensive to aspirin, having implications for current antiplatelet therapy regimes. In conclusion, differential platelet responses and antiplatelet efficacy are observed on ECM composites phenotypic of plaque rupture and erosion. Proteoglycans inhibit thrombus formation and may offer a novel plaque-specific approach to limit arterial thrombosis.

Reprogramming of VEGF-mediated extracellular matrix changes through autocrine signaling

Vascular endothelial growth factor (VEGF) plays key roles in angiogenesis, vasculogenesis, and wound healing. In cancers, including triple negative breast cancer (TNBC), VEGF has been associated with increased invasion and metastasis, processes that require cancer cells to traverse through the extracellular matrix (ECM) and establish angiogenesis at distant sites. To further understand the role of VEGF in modifying the ECM, we characterized VEGF-mediated changes in the ECM of tumors derived from TNBC MDA-MB-231 cells engineered to overexpress VEGF. We established that increased VEGF expression by these cells resulted in tumors with reduced collagen 1 (Col1) fibers, fibronectin, and hyaluronan. Molecular characterization of tumors identified an increase of MMP1, uPAR, and LOX, and a decrease of MMP2, and ADAMTS1. α-SMA, a marker of cancer associated fibroblasts (CAFs), increased, and FAP-α, a marker of a subset of CAFs associated with immune suppression, decreased with VEGF overexpression. Analysis of human data from The Cancer Genome Atlas Program confirmed mRNA differences for several molecules when comparing TNBC with high and low VEGF expression. We additionally characterized enzymatic changes induced by VEGF overexpression in three different cancer cell lines that clearly identified autocrine-mediated changes, specifically uPAR, in these enzymes. Unlike the increase of Col1 fibers and fibronectin mediated by VEGF during wound healing, in the TNBC model, VEGF significantly reduced key protein components of the ECM. These results further expand our understanding of the role of VEGF in cancer progression and identify potential ECM-related targets to disrupt this progression.

Scale-Dependent Rheology of Synovial Fluid Lubricating Macromolecules

Synovial fluid (SF) is the complex biofluid that facilitates the exceptional lubrication of articular cartilage in joints. Its primary lubricating macromolecules, the linear polysaccharide hyaluronic acid (HA) and the mucin-like glycoprotein proteoglycan 4 (PRG4 or lubricin), interact synergistically to reduce boundary friction. However, the precise manner in which these molecules influence the rheological properties of SF remains unclear. This study aimed to elucidate this by employing confocal microscopy and multiscale rheometry to examine the microstructure and rheology of solutions containing recombinant human PRG4 (rhPRG4) and HA. Contrary to previous assumptions of an extensive HA-rhPRG4 network, it is discovered that rhPRG4 primarily forms stiff, gel-like aggregates. The properties of these aggregates, including their size and stiffness, are found to be influenced by the viscoelastic characteristics of the surrounding HA matrix. Consequently, the rheology of this system is not governed by a single length scale, but instead responds as a disordered, hierarchical network with solid-like rhPRG4 aggregates distributed throughout the continuous HA phase. These findings provide new insights into the biomechanical function of PRG4 in cartilage lubrication and may have implications in the development of HA-based therapies for joint diseases like osteoarthritis.

The Effect of Mechanical Stress on Hyaluronan Fragments' Inflammatory Cascade: Clinical Implications

It is a common experience, reported by patients who have undergone manual therapy that uses deep friction, to perceive soreness in treatment areas; however, it is still not clear what causes it and if it is therapeutically useful or a simple side effect. The purpose of this narrative review is to determine whether manual and physical therapies can catalyze an inflammatory process driven by HA fragments. The literature supports the hypothesis that mechanical stress can depolymerize into small pieces at low molecular weight and have a high inflammatory capacity. Many of these pieces are then further degraded into small oligosaccharides. Recently, it has been demonstrated that oligosaccharides are able to stop this inflammatory process. These data support the hypothesis that manual therapy that uses deep friction could metabolize self-aggregated HA chains responsible for increasing loose connective tissue viscosity, catalyzing a local HA fragment cascade that will generate soreness but, at the same time, facilitate the reconstitution of the physiological loose connective tissue properties. This information can help to explain the meaning of the inflammatory process as well as the requirement for it for the long-lasting resolution of these alterations.

Effects of Radiation-Induced Skin Injury on Hyaluronan Degradation and Its Underlying Mechanisms

Radiation-induced skin injury (RISI) is a frequent and severe complication with a complex pathogenesis that often occurs during radiation therapy, nuclear incidents, and nuclear war, for which there is no effective treatment. Hyaluronan (HA) plays an overwhelming role in the skin, and it has been shown that UVB irradiation induces increased HA expression. Nevertheless, to the best of our knowledge, there has been no study regarding the biological correlation between RISI and HA degradation and its underlying mechanisms. Therefore, in our study, we investigated low-molecular-weight HA content using an enzyme-linked immunosorbent assay and changes in the expression of HA-related metabolic enzymes using real-time quantitative polymerase chain reaction and a Western blotting assay. The oxidative stress level of the RISI model was assessed using sodium dismutase, malondialdehyde, and reactive oxygen species assays. We demonstrated that low-molecular-weight HA content was significantly upregulated in skin tissues during the late phase of irradiation exposure in the RISI model and that HA-related metabolic enzymes, oxidative stress levels, the MEK5/ERK5 pathway, and inflammatory factors were consistent with changes in low-molecular-weight HA content. These findings prove that HA degradation is biologically relevant to RISI development and that the HA degradation mechanisms are related to HA-related metabolic enzymes, oxidative stress, and inflammatory factors. The MEK5/ERK5 pathway represents a potential mechanism of HA degradation. In conclusion, we aimed to investigate changes in HA content and preliminarily investigate the HA degradation mechanism in a RISI model under γ-ray irradiation, to consider HA as a new target for RISI and provide ideas for novel drug development.

Oral administration of hyaluronic acid to improve skin conditions via a randomized double-blind clinical test

OBJECTIVE

To evaluate the impact of oral intake of Hyaluronic Acid (HA) on skin health.

BACKGROUND

HA, an endogenous substance in the human body, plays a key role in skin health. However, its concentration in the skin decreases significantly with age. Previous studies suggested that oral intake of HA can supplement the body's HA level, but did not reveal the effects on different age groups and skin types.

METHODS

A double-blind, randomized clinical trial with 129 female participants, covering young and elderly groups and differnet skin types, was conducted to assess the efficacy of orally administered HA on skin health.

RESULTS

Oral administration of HA significantly promoted skin hydration after 2-8 weeks among both young and elderly groups. Skin tone improvement was observed after 4-8 weeks, while an increase in epidermal thickness was noted after 12 weeks.

CONCLUSION

This study provides direct evidence supporting the clinical efficacy of oral intake of HA in promoting skin health.

Cell Microencapsulation Within Engineered Hyaluronan Elastin-Like Protein (HELP) Hydrogels

Three-dimensional cell encapsulation has rendered itself a staple in the tissue engineering field. Using recombinantly engineered, biopolymer-based hydrogels to encapsulate cells is especially promising due to the enhanced control and tunability it affords. Here, we describe in detail the synthesis of our hyaluronan (i.e., hyaluronic acid) and elastin-like protein (HELP) hydrogel system. In addition to validating the efficacy of our synthetic process, we also demonstrate the modularity of the HELP system. Finally, we show that cells can be encapsulated within HELP gels over a range of stiffnesses, exhibit strong viability, and respond to stiffness cues. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Elastin-like protein modification with hydrazine Basic Protocol 2: Nuclear magnetic resonance quantification of elastin-like protein modification with hydrazine Basic Protocol 3: Hyaluronic acid-benzaldehyde synthesis Basic Protocol 4: Nuclear magnetic resonance quantification of hyaluronic acid-benzaldehyde Basic Protocol 5: 3D cell encapsulation in hyaluronan elastin-like protein gels.

In Vitro Assessment of Cisplatin/Hyaluronan Complex for Loco-Regional Chemotherapy

Loco-regional chemotherapy is a strategy used to achieve more precise anticancer drug effect directly on tumor mass, while decreasing whole body exposure, which can lead to undesirable side effects. Thus, the loco-regional chemotherapy is conceptually similar to the targeted drug delivery systems for delivering chemotherapeutics to cancer cells in a certain location of the body. Recently, it has been demonstrated that a novel polymeric film containing the complex between cisplatin (cisPt) and hyaluronan (sodium salt of hyaluronic acid; NaHA) enhanced in vivo efficacy and safety of cisplatin (cisPt) by loco-regional delivery in pleural mesothelioma. Biologically, hyaluronic acid (HA) binds with the CD44 receptor, which is a transmembrane glycoprotein overexpressed by other cancer cells. Thus, administering both cisPt and hyaluronan together as a complex loco-regionally to the tumor site could target cancer cells locally and enhance treatment safety. A slight excess of hyaluronan was required to have more than 85% cisPt complexation. In cell monolayers (2D model) the cisPt/NaHA complex in solution demonstrated dose- and time-dependent cytotoxic effect by decreasing the viability of pancreatic, melanoma, and lung cell lines (they all express CD44). At the same concentration in solution, the complex was as effective as cisPt alone. However, when applied as film to melanoma spheroids (3D model), the complex was superior because it prevented the tumor spheroid growth and, more importantly, the formation of new cell colonies. Hence, cisPt/NaHA complex could work in preventing metastases loco-regionally and potentially avoiding systemic relapses.

Impact of hyaluronan size on localization and solubility of the extracellular matrix in the mouse brain

Hyaluronan (HA) is a central component of the extracellular matrix (ECM) in the brain and plays a pivotal role in neural development and plasticity. Brain HA exists in 2 distinct forms of the ECM: the diffuse ECM, which is soluble in saline and detergents, and the condensed ECM, which forms aggregates, such as perineuronal nets (PNNs). Although the physiological functions of HA significantly differ depending on its size, size differences in HA have not yet been examined in the 2 ECM types, which is partly because of the lack of methods to rapidly and accurately measure the molecular weight (MW) of HA. In this study, we established a simple method to simultaneously assess the MW of HA in multiple crude biological samples. HA was purified through single-step precipitation from tissue extracts using biotinylated HA-binding protein and streptavidin-coupled magnetic beads, followed by separation on gel electrophoresis. By applying this method to HA in the mouse brain, we revealed that the condensed ECM contained higher MW HA than the diffuse ECM. Higher MW HA and lower MW HA exhibited different spatial distributions: the former was confined to PNNs, whereas the latter was widely present throughout the brain. Furthermore, the limited degradation of HA showed that only higher MW HA was required to form an insoluble HA-aggrecan complex. The present study demonstrated that the MW of HA in the brain strongly correlates with the localization and solubility of the ECM it forms.

Endothelial cell activation and glycocalyx shedding - potential as biomarkers in patients with lupus nephritis

Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus and an important cause of acute and chronic kidney injury. Early diagnosis of LN and preventing relapses are key to preserving renal reserve. However, due to the complexity and heterogeneity of the disease, clinical management remains challenging. Kidney biopsy remains the gold standard for confirming the diagnosis of LN and subsequent assessment of kidney histopathology, but it is invasive and cannot be repeated frequently. Current clinical indicators of kidney function such as proteinuria and serum creatinine level are non-specific and do not accurately reflect histopathological changes, while anti-dsDNA antibody and C3 levels reflect immunological status but not kidney injury. Identification of novel and specific biomarkers for LN is prerequisite to improve management. Renal function deterioration is associated with changes in the endothelial glycocalyx, a delicate gel-like layer located at the interface between the endothelium and bloodstream. Inflammation induces endothelial cell activation and shedding of glycocalyx constituents into the circulation. This review discusses the potential role of soluble glycocalyx components as biomarkers of active LN, especially in patients in whom conventional serological and biochemical markers do not appear helpful.

Characterization of the Limbal Epithelial Stem Cell Niche

Purpose

Limbal epithelial stem cells (LESCs) reside within a LSC niche (LSCN). We recently identified that hyaluronan (HA) is a major constituent of the LSCN, and that HA is necessary for maintaining LESCs in the "stem cell" state, both in vitro and in vivo. Herein, we characterized the LSCN to identify key components of the HA-specific LSCN.

Methods

The cornea and limbal rim were dissected from mouse corneas, subjected to mRNA extraction, and sequenced using a NextSeq 500 (Illumina) and data processed using CLC Genomics Workbench 20 (Qiagen) and the STRING database to identify key components of the LSCN. Their expression was confirmed by real-time PCR, Western blotting, and immunohistochemistry. Furthermore, the differential expression of key compounds in different corneal cell types were determined with single-cell RNA sequencing.

Results

We identified that the hyaladherins inter-alpha-inhibitor (IαI), TSG-6 and versican are highly expressed in the limbus. Specifically, HA/HC complexes are present in the LSCN, in the stroma underlying the limbal epithelium, and surrounding the limbal vasculature. For IαI, heavy chains 5 and 2 (HC5 and HC2) were found to be the most highly expressed HCs in the mouse and human limbus and were associate with HA-forming HA/HC-specific matrices.

Conclusions

The LSCN contains HA/HC complexes, which have been previously correlated with stem cell niches. The identification of HA/HC complexes in the LSCN could serve as a new therapeutic avenue for treating corneal pathology. Additionally, HA/HC complexes could be used as a substrate for culturing LESCs before LESC transplantation.

The hyaluronan metabolism in the UV-irradiated human epidermis and the relevance of in vitro epidermal models

Exposure to the sun affects the skin and may eventually result in UV-induced skin damage. It is generally known that hyaluronan (HA) is one of the main structural and functional components of the skin. However, UV-related changes in the HA metabolism in the skin have not yet been elucidated. Using qRT-PCR, confocal microscopy and LC-MS/MS we compared the naturally sun-exposed (SE), sun-protected, experimentally repeatedly UVA + UVB-exposed and acutely (once) UVA + UVB irradiated skin of Caucasian women. The epidermis was harvested by means of suction blistering 24 h after the acute irradiation. In addition, the epidermis was compared with a UV-irradiated in vitro reconstituted 3D epidermis (EpiDerm) and an in vitro 2D culture of normal human keratinocytes (NHEK). The amount of HA was found to be statistically significantly enhanced in the acutely irradiated epidermis. The acute UV evinced the upregulation of HA synthases (HAS2 and HAS3), hyaluronidases (HYAL2 and HYAL3), Cluster of differentiation 44 (CD44), and Cell Migration Inducing Proteins (CEMIP and CEMIP2), while only certain changes were recapitulated in the 3D epidermis. For the first time, we demonstrated the enhanced gene and protein expression of CEMIP and CEMIP2 following UV irradiation in the human epidermis. The data suggest that the HA metabolism is affected by UV in the irradiated epidermis and that the response can be modulated by the underlying dermis.

Removal of the endothelial surface layer via hyaluronidase does not modulate monocyte and neutrophil interactions with the glomerular endothelium

OBJECTIVE

The endothelial surface layer (ESL), a layer of macromolecules on the surface of endothelial cells, can both impede and facilitate leukocyte recruitment. However, its role in monocyte and neutrophil recruitment in glomerular capillaries is unknown.

METHODS

We used multiphoton intravital microscopy to examine monocyte and neutrophil behavior in the glomerulus following ESL disruption with hyaluronidase.

RESULTS

Constitutive retention and migration of monocytes and neutrophils within the glomerular microvasculature was unaltered by hyaluronidase. Consistent with this, inhibition of the hyaluronan-binding molecule CD44 also failed to modulate glomerular trafficking of these immune cells. To investigate the contribution of the ESL during acute inflammation, we induced glomerulonephritis via in situ immune complex deposition. This resulted in increases in glomerular retention of monocytes and neutrophils but did not induce marked reduction in the glomerular ESL. Furthermore, hyaluronidase treatment did not modify the prolonged retention of monocytes and neutrophils in the acutely inflamed glomerular microvasculature.

CONCLUSIONS

These observations indicate that, despite evidence that the ESL has the capacity to inhibit leukocyte-endothelial cell interactions while also containing adhesive ligands for immune cells, neither of these functions modulate trafficking of monocytes and neutrophils in steady-state or acutely-inflamed glomeruli.

Development and Bioactivity of Zinc Sulfate Cross-Linked Polysaccharide Delivery System of Dexamethasone Phosphate

Improving the biopharmaceutical properties of glucocorticoids (increasing local bioavailability and reducing systemic toxicity) is an important challenge. The aim of this study was to develop a dexamethasone phosphate (DexP) delivery system based on hyaluronic acid (HA) and a water-soluble cationic chitosan derivative, diethylaminoethyl chitosan (DEAECS). The DexP delivery system was a polyelectrolyte complex (PEC) resulting from interpolymer interactions between the HA polyanion and the DEAECS polycation with simultaneous incorporation of zinc ions as a cross-linking agent into the complex. The developed PECs had a hydrodynamic diameter of 244 nm and a ζ-potential of +24.4 mV; the encapsulation efficiency and DexP content were 75.6% and 45.4 μg/mg, respectively. The designed DexP delivery systems were characterized by both excellent mucoadhesion and prolonged drug release (approximately 70% of DexP was released within 10 h). In vitro experiments showed that encapsulation of DexP in polysaccharide nanocarriers did not reduce its anti-inflammatory activity compared to free DexP.

Differential Effects of Pancreatic Cancer-Derived Extracellular Vesicles Driving a Suppressive Environment

Pancreatic ductal adenocarcinoma (PDAC) cells display extensive crosstalk with their surrounding environment to regulate tumor growth, immune evasion, and metastasis. Recent advances have attributed many of these interactions to intercellular communication mediated by small extracellular vesicles (sEVs), involving cancer-associated fibroblasts (CAF). To explore the impact of sEVs on monocyte lineage transition as well as the expression of checkpoint receptors and activation markers, peripheral blood monocytes from healthy subjects were exposed to PDAC-derived sEVs. Additionally, to analyze the role of sEV-associated HA in immune regulation and tissue-resident fibroblasts, monocytes and pancreatic stellate cells were cultured in the presence of PDAC sEVs with or depleted of HA. Exposure of monocytes to sEVs resulted in unique phenotypic changes in HLA-DR, PD-L1, CD86 and CD64 expression, and cytokine secretion that was HA-independent except for IL-1β and MIP1β. In contrast, monocyte suppression of autologous T cell proliferation was reduced following exposure to HA-low sEVs. In addition, exposure of stellate cells to sEVs upregulated the secretion of various cytokines, including MMP-9, while removal of HA from PDAC-derived sEVs attenuated the secretion of MMP-9, demonstrating the role of sEV-associated HA in regulating expression of this pro-tumorigenic cytokine from stellate cells. This observation lends credence to the findings from the TCGA database that PDAC patients with high levels of enzymes in the HA synthesis pathway had worse survival rates compared with patients having low expression of these enzymes. PDAC-derived sEVs have an immune modulatory role affecting the activation state of monocyte subtypes. However, sEV-associated HA does not affect monocyte phenotype but alters cytokine secretion and suppression of autologous T cell proliferation and induces secretion of pro-tumorigenic factors by pancreatic stellate cells (PSC), as has been seen following the conversion of PSCs to cancer-associated fibroblasts (CAFs). Interruption of the hexosamine biosynthetic pathway, activated in PDAC producing the key substrate (UDP-GlcNAc) for HA synthesis, thus, represents a potential clinical interception strategy for PDAC patients. Findings warrant further investigations of underlying mechanisms involving larger sample cohorts.

Tumor Response to Stroma-Modifying Therapy: Magnetic Resonance Imaging Findings in Early-Phase Clinical Trials of Pegvorhyaluronidase alpha (PEGPH20)

Pre-clinical and clinical studies have shown that PEGPH20 depletes intratumoral hyaluronic acid (HA), which is linked to high interstitial fluid pressures and poor distribution of chemotherapies. 29 patients with metastatic advanced solid tumors received quantitative magnetic resonance imaging (qMRI) in 3 prospective clinical trials of PEGPH20, HALO-109-101 (NCT00834704), HALO-109-102 (NCT01170897), and HALO-109-201 (NCT01453153). Apparent Diffusion Coefficient of water (ADC), T1, ktrans, vp, ve, and iAUC maps were computed from qMRI acquired at baseline and ≥ 1 time point post-PEGPH20. Tumor ADC and T1 decreased, while iAUC, ktrans, vp, and ve increased, on day 1 post-PEGPH20 relative to baseline values. This is consistent with HA depletion leading to a decrease in tumor water content and an increase in perfusion, permeability, extracellular matrix space, and vascularity. Baseline parameter values that were predictive of pharmacodynamic responses were: ADC > 1.46×10-3 mm2/s (Balanced Accuracy (BA) = 72%, p < 0.01), T1 > 0.54s (BA = 82%, p < 0.01), iAUC < 9.2 mM-s (BA = 76%, p < 0.05), ktrans<0.07min-1 (BA = 72%, p = 0.2), ve<0.17 (BA = 68%, p < 0.01), and vp<0.02 (BA = 60%, p < 0.01). Further, ve<0.39 at baseline was moderately predictive of response in any parameter (BA = 65.6%, p < 0.01 averaged across patients). These qMRI biomarkers are potentially useful for guiding patient pre-selection and post-treatment follow-up in future clinical studies of PEGPH20 and other tumor stroma-modifying anti-cancer therapies.

CD44‑hyaluronan axis plays a role in the interactions between colon cancer‑derived extracellular vesicles and human monocytes

During tumor progression, monocytes circulating in the blood or infiltrating tissue may be exposed to tumor-derived extracellular vesicles (TEVs). The first stage of such interactions involves binding of TEVs to the surface of monocytes, followed by their internalization. The present study examines the role of CD44 molecules in the interactions between monocytes and EVs derived from colon cancer cell lines (HCT116 and SW1116). The efficiency of the attachment and engulfment of TEVs by monocytes is linked to the number of TEVs and time of exposure/interaction. The two investigated TEVs, TEVsHCT116 and TEVsSW1116, originating from HCT116 and SW1116 cells, respectively, differ in hyaluronan (HA) cargo, which reflects HA secretion by parental cancer cells. HA-rich TEVsHCT116 are internalized more effectively in comparison with HA-low TEVsSW1116. Blocking of CD44 molecules on monocytes by anti-CD44 monoclonal antibody significantly decreased the engulfment of TEVsHCT116 but not that of TEVsSW1116 after 30 min contact, suggesting the involvement of the HA-CD44 axis. The three subsets of monocytes, classical, intermediate and non-classical, characterized by gradual changes in the expression of CD14 and CD16 markers, also differ in the expression of CD44. The highest expression of CD44 molecules was observed in the intermediate monocyte subset. Blocking of CD44 molecules decreased the internalization of HA-rich TEVs in all three subsets, which is associated with CD44 expression level. It was hypothesized that HA carried by TEVs, potentially as a component of the 'corona' coating, may facilitate the interaction between subsets of monocytes and TEVs, which may influence the fate of TEVs (such as the rate of TEVs adhesion and engulfment) and change monocyte activity.

Hyaluronic acid: An overlooked extracellular vesicle contaminant

The variable presence of contaminants in extracellular vesicle (EV) samples is one of the major contributors to a lack of inter-study reproducibility in the field. Well-known contaminants include protein aggregates, RNA-protein complexes and lipoproteins, which resemble EVs in shape, size and/or density. On the contrary, polysaccharides, such as hyaluronic acid (HA), have been overlooked as EV contaminants. Here, it is shown that low and medium molecular weight HA polymers are unexpectedly retained to some extent in EV fractions using two common isolation methods known for high purity: size-exclusion chromatography and tangential flow filtration. Although these isolation techniques are capable of efficient removal of non-EV-associated proteins, this is not the case for HA polymers, which are partially retained in a molecular weight-dependent manner, especially with size-exclusion chromatography. The supramolecular structure and hydrodynamic size of HA are likely to contribute to isolation in EV fractions of filtration-based approaches. Conversely, HA polymers were not retained with ultracentrifugation and polymer-based precipitation methods, which are known for co-isolating other types of contaminants. HA has a broad range of immunomodulatory effects, similar to those ascribed to various sources of EVs. Therefore, HA contaminants should be considered in future studies to avoid potential inaccurate attributions of functional effects to EVs.

TMEM2 is a bona fide hyaluronidase possessing intrinsic catalytic activity

Transmembrane protein 2 (TMEM2) was originally identified as a membrane-anchored protein of unknown function. We previously demonstrated that TMEM2 can degrade hyaluronan (HA). Furthermore, we showed that induced global knockout of Tmem2 in adult mice results in rapid accumulation of incompletely degraded HA in bodily fluids and organs, supporting the identity of TMEM2 as a cell surface hyaluronidase. In spite of these advances, no direct evidence has been presented to demonstrate the intrinsic hyaluronidase activity of TMEM2. Here, we directly establish the catalytic activity of TMEM2. The ectodomain of TMEM2 (TMEM2ECD) was expressed as a His-tagged soluble protein and purified by affinity and size-exclusion chromatography. Both human and mouse TMEM2ECD robustly degrade fluorescein-labeled HA into 5 to 10 kDa fragments. TMEM2ECD exhibits this HA-degrading activity irrespective of the species of TMEM2 origin and the position of epitope tag insertion. The HA-degrading activity of TMEM2ECD is more potent than that of HYAL2, a hyaluronidase which, like TMEM2, has been implicated in cell surface HA degradation. Finally, we show that TMEM2ECD can degrade not only fluorescein-labeled HA but also native high-molecular weight HA. In addition to these core findings, our study reveals hitherto unrecognized confounding factors, such as the quality of reagents and the choice of assay systems, that could lead to erroneous conclusions regarding the catalytic activity of TMEM2. In conclusion, our results demonstrate that TMEM2 is a legitimate functional hyaluronidase. Our findings also raise cautions regarding the choice of reagents and methods for performing degradation assays for hyaluronidases.

Effects of Cross-linked Hyaluronic Acid in a Rat Model of Vestibular and Cochlear Toxicity

Objective

To investigate the effects of cross-linked hyaluronic acid (CLHA) in an experimental model of vestibulotoxicity and cochleotoxicity.

Methods

Twenty-eight female Wistar albino rats (200-250 g) were divided into four groups. Group A received 0.06 mL of 13.33 mg/mL gentamicin, Group B received 0.06 mL of CLHA, Group C received 0.03 mL of 26.66 mg/mL gentamicin and 0.03 mL CLHA, and Group D received 0.06 mL of 0.09% saline. All groups underwent auditory brainstem response testing at 4-32 kHz, signal-to-noise ratio of distortion product otoacoustic emission measurements at 1.5-8 kHz and vestibular tests on days 0,1,7,10. The rats were sacrificed, and their labyrinths were histologically assessed and scored.

Results

The hearing thresholds of Groups A and C were similar and significantly higher than those of the other groups at all frequencies, beginning from day 1. The vestibular and histological scores of Groups A and C were similar and significantly higher than those of the other groups from day 1. The audiological results, vestibular scores, and histological scores of Groups B and D were similar, except for a temporary middle ear effusion and hearing threshold shift in Group B. No significant deterioration was observed in the audiological, vestibular, and histological analyses of Groups B and D.

Conclusion

That both Group A and Group C similarly showed worsening audiological, vestibular, and histological tests suggests that CLHA did not alter the pharmacokinetics and histologic results of gentamicin.

Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

Development of Therapeutic Agent for Osteoarthritis via Inhibition of KIAA1199 Activity: Effect of Ipriflavone In Vivo

This study aimed to clarify the effects of ipriflavone, which effectively reduces KIAA1199 activity, on osteoarthritis (OA) development and progression in an in vivo OA mouse model. The OA model mice were divided into the ipriflavone (200 mg/kg/day) group and the control group. OA onset and progression were evaluated with the Mankin score, and KIAA1199 expression and hyaluronan (HA) accumulation were analyzed by immunostaining. The molecular weight of HA in the cartilage tissue and serum HA concentration were analyzed by chromatography and competitive HA enzyme-linked immunoassay. The effects of ipriflavone on the bovine cartilage explant culture under the influence of IL-1β were also investigated. In the ipriflavone group, Safranin-O stainability was well-preserved, resulting in significant reduction of the Mankin score (p = 0.027). KIAA1199 staining positivity decreased and HA stainability was preserved in the ipriflavone group. The serum HA concentration decreased, and the molecular weight of HA in the cartilage tissue increased in the ipriflavone group. The results of the cartilage explant culture indicated that ipriflavone could reduce GAG losses and increase the molecular weight of HA. Thus, ipriflavone may have an inhibitory effect on OA development/progression. Ipriflavone could be a therapeutic drug for OA by targeting KIAA1199 activity.

Octenidine with hyaluronan dressing versus a silver dressing in hard-to-heal wounds: a post-marketing study

OBJECTIVE

This study was conducted to provide comparative data on the clinical efficacy and safety of a novel hard-to-heal wound dressing (Sorelex; Contipro a.s., Czech Republic) that combines octenidine and hyaluronan, compared with a silver-based dressing.

METHOD

This multicentre, open-label, randomised, post-market, clinical follow-up study provides a comparison of a octenidine and hyaluronan combination with a standard-of-care (SoC) silver-containing dressing. The investigators evaluated the management of infection in the hard-to-heal wounds based on recorded changes in the appearance of the wound bed tissue and the presence of clinical signs of infection after three weeks of treatment. Other relevant assessed parameters of wound healing were: wound size; exudation level; wound pain level; and surrounding skin appearance.

RESULTS

The study cohort included 48 patients in the Sorelex arm and 39 patients in the SoC arm. Both products evinced numerous parameters of wound infection management: reductions in the wound bed slough; marked decreases in wound size; the formation of re-epithelialisation and granulation tissue; and improved pain management. Sorelex significantly improved the condition of surrounding skin after three weeks of treatment, unlike SoC. Sorelex reduced wound area significantly more than SoC (p=0.04). No statistically significant differences were detected in other assessed parameters between the two study arms. All the participating investigators expressed their satisfaction with both products. No adverse reactions to Sorelex were recorded over the mean treatment period of 53 days.

CONCLUSION

The octenidine and hyaluronan combination provides a new alternative choice of dressing for the treatment of infected hard-to-heal wounds when compared with a silver-based product.

Hyaluronan hydrates and compartmentalises the CNS/PNS extracellular matrix and provides niche environments conducive to the optimisation of neuronal activity

The central nervous system/peripheral nervous system (CNS/PNS) extracellular matrix is a dynamic and highly interactive space-filling, cell-supportive, matrix-stabilising, hydrating entity that creates and maintains tissue compartments to facilitate regional ionic micro-environments and micro-gradients that promote optimal neural cellular activity. The CNS/PNS does not contain large supportive collagenous and elastic fibrillar networks but is dominated by a high glycosaminoglycan content, predominantly hyaluronan (HA) and collagen is restricted to the brain microvasculature, blood-brain barrier, neuromuscular junction and meninges dura, arachnoid and pia mater. Chondroitin sulphate-rich proteoglycans (lecticans) interactive with HA have stabilising roles in perineuronal nets and contribute to neural plasticity, memory and cognitive processes. Hyaluronan also interacts with sialoproteoglycan associated with cones and rods (SPACRCAN) to stabilise the interphotoreceptor matrix and has protective properties that ensure photoreceptor viability and function is maintained. HA also regulates myelination/re-myelination in neural networks. HA fragmentation has been observed in white matter injury, multiple sclerosis, and traumatic brain injury. HA fragments (2 × 105  Da) regulate oligodendrocyte precursor cell maturation, myelination/remyelination, and interact with TLR4 to initiate signalling cascades that mediate myelin basic protein transcription. HA and its fragments have regulatory roles over myelination which ensure high axonal neurotransduction rates are maintained in neural networks. Glioma is a particularly invasive brain tumour with extremely high mortality rates. HA, CD44 and RHAMM (receptor for HA-mediated motility) HA receptors are highly expressed in this tumour. Conventional anti-glioma drug treatments have been largely ineffective and surgical removal is normally not an option. CD44 and RHAMM glioma HA receptors can potentially be used to target gliomas with PEP-1, a cell-penetrating HA-binding peptide. PEP-1 can be conjugated to a therapeutic drug; such drug conjugates have successfully treated dense non-operative tumours in other tissues, therefore similar applications warrant exploration as potential anti-glioma treatments.

V3: an enigmatic isoform of the proteoglycan versican

V3 is an isoform of the extracellular matrix (ECM) proteoglycan (PG) versican generated through alternative splicing of the versican gene such that the two major exons coding for sequences in the protein core that support chondroitin sulfate (CS) glycosaminoglycan (GAG) chain attachment are excluded. Thus, versican V3 isoform carries no GAGs. A survey of PubMed reveals only 50 publications specifically on V3 versican, so it is a very understudied member of the versican family, partly because to date there are no antibodies that can distinguish V3 from the CS-carrying isoforms of versican, that is, to facilitate functional and mechanistic studies. However, a number of in vitro and in vivo studies have identified the expression of the V3 transcript during different phases of development and in disease, and selective overexpression of V3 has shown dramatic phenotypic effects in "gain and loss of function" studies in experimental models. Thus, we thought it would be useful and instructive to discuss the discovery, characterization, and the putative biological importance of the enigmatic V3 isoform of versican.

Commentary on a Classic JHC Article on Intracellular Hyaluronan Associated With the Mitotic Spindle

The authors of the accompanying classic paper from the Journal of Histochemistry and Cytochemistry (Evanko SP, Wight TN. Intracellular Localization of Hyaluronan in Proliferating Cells. Journal of Histochemistry & Cytochemistry. 1999;47[10]:1331-1341) comment on the impact and significance of their findings on the intracellular localization of hyaluronan in arterial smooth muscle cells using immunohistochemical techniques. These seminal findings signaled the potential for a role of hyaluronan in the functions of microtubules and mitosis.

Cellular and extracellular vaginal changes following murine ovarian removal

Loss of estrogen as a result of aging, pelvic cancer therapy, genetics, or eating disorders affects numerous body systems including the reproductive tract. Specifically, a chronic hypoestrogenic state fosters debilitating vaginal symptoms like atrophy, dryness, and dyspareunia. Current treatment options, including vaginal estrogen and hyaluronan (HA), anecdotally improve symptoms, but rectifying mechanisms are largely understudied. In order to study the hypoestrogenic vaginal environment, in particular the extracellular matrix (ECM), as well as understand the mechanisms behind current treatments and develop new therapies, we characterized a reliable and reproducible animal model. Bilateral ovariectomies (OVX) were performed on 9-week-old CD1 mice. After 1 month of estrogen loss due to ovarian removal, a phenotype that is similar to human vaginal tissue in an estrogen reduced state was noted in mice compared to sham-operated controls. The uterine to body weight ratio decreased by 80% and vaginal epithelium was significantly thinner in OVX compared to sham mice. Estrogen signaling was altered in OVX, but submucosal ERα localization did not reach statistical differences. HA localization in the submucosal area was altered and CD44 expression decreased in OVX mice. Collagen turn-over was altered following OVX. The inflammation profile was also disrupted, and submucosal vaginal CD45+ and F4/80+ cell populations were significantly reduced in the OVX mice. These results show altered cellular and molecular changes due to reduced estrogen levels. Developing new treatments for hypoestrogenic vaginal symptoms rely on better understanding of not only the cellular changes, but also the altered vaginal ECM environment. Further studies using this mouse model has the potential to advance women's vaginal health treatments and aid in understanding the interplay between organ systems in both healthy, aged, and diseased states.

Hyaluronan synthesis inhibition normalizes ethanol-enhanced hepatic stellate cell activation

BACKGROUND

Chronic ethanol overconsumption promotes alcohol-associated liver disease (ALD), characterized by hepatocyte injury, inflammation, hepatic stellate cell (HSC) activation, and fibrosis. Hyaluronan (HA) concentration is greater in livers and blood from advanced ALD patients than patients with advanced non-ALD. In the liver, HSCs are the major HA producers. The relationship between ethanol, HA, and HSC activation is incompletely understood. Thus, here, we tested the hypothesis that ethanol enhances HSC activation in a HA-dependent manner.

METHODS

Liver tissue microarrays (TMAs) containing steatotic livers from donors with or without a history of alcohol consumption were used to measure HA and collagen content. Mice were fed a moderate (2%, v/v) ethanol-containing diet or pair-fed control diet for 2 days, after which they were given a single carbon tetrachloride (CCl4 ) injection. To inhibit HA synthesis, we provided 4-methylumbelliferone (4MU) daily. We used LX2 cells, a human HSC cell line, to determine the impact ethanol had on LPS responses, with or without concurrent 4MU exposure.

RESULTS

CCl4 induced liver injury, but it did not differ between ethanol or control diet fed mice with or without 4MU treatment. Ethanol feeding enhanced CCl4 -induced hepatic HA content, which was paralleled by HA synthase (Has)2 transcript abundance; 4MU treatment normalized both. Consistently, HSC activation, assessed by measuring αSMA mRNA and protein, was induced by CCl4 exposure, enhanced by ethanol feeding, and normalized by 4MU. Hepatic transcripts, but not protein, for Ccl2 were enhanced by ethanol feeding and normalized by 4MU exposure. Finally, ethanol-exposed LX2 cells made more LPS-stimulated CCL2 mRNA and protein than cells not exposed to ethanol; 4MU prevented this.

CONCLUSION

These data show that ethanol augments HSC activation through HA synthesis and enhances hepatic profibrogenic features. Therefore, targeting HSC HA production could potentially attenuate liver disease in ALD patients.

Hyaluronic Acid-Based Bioconjugate Systems, Scaffolds, and Their Therapeutic Potential

In recent years, the development of hyaluronic acid or hyaluronan (HA) based scaffolds, medical devices, bioconjugate systems have expanded into a broad range of research and clinical applications. Research findings over the last two decades suggest that the abundance of HA in most mammalian tissues with distinctive biological roles and chemical simplicity for modifications have made it an attractive material with a rapidly growing global market. Besides its use as native forms, HA has received much interest on so-called "HA-bioconjugates" and "modified-HA systems". In this review, the importance of chemical modifications of HA, underlying rationale approaches, and various advancements of bioconjugate derivatives with their potential physicochemical, and pharmacological advantages are summarized. This review also highlights the current and emerging HA-based conjugates of small molecules, macromolecules, crosslinked systems, and surface coating strategies with their biological implications, including their potentials and key challenges discussed in detail.

The Intraoperative Use of Defensive Antibacterial Coating (DAC®) in the Form of a Gel to Prevent Peri-Implant Infections in Orthopaedic Surgery: A Clinical Narrative Review

Periprosthetic joint infections (PJIs) in arthroplasty and osteosynthesis-associated infections (OAIs) in reconstructive surgery still represent a challenging complication in orthopaedics and traumatology causing a burden worsening the patient's quality of life, for caregiver and treating physicians, and for healthcare systems. PJIs and OAIs are the result of bacterial adhesion over an implant surface with subsequent biofilm formation. Therefore, the clinical pathological outcome is a difficult-to-eradicate persistent infection. Strategies to treat PJIs and OAIs involve debridement, the replacement of internal fixators or articular prostheses, and intravenous antibiotics. However, long treatments and surgical revision cause discomfort for patients; hence, the prevention of PJIs and OAIs represents a higher priority than treatment. Local antibiotic treatments through coating-release systems are becoming a smart approach to prevent this complication. Hydrophilic coatings, loaded with antibiotics, simultaneously provide a barrier effect against bacterial adhesion and allow for the local delivery of an antibiotic. The intraoperative use of a hyaluronan (HY)-derivative coating in the form of a gel, loaded with antibiotics to prevent PJI, has recently raised interest in orthopaedics. Current evidence supports the use of this coating in the prophylaxis of PJI and IRIs in terms of clinical outcomes and infection reduction. Thus, the purpose of this narrative review is to assess the use of a commercially available HY derivative in the form of a gel, highlighting the characteristics of this biomaterial, which makes it attractive for the management of PJIs and IRIs in orthopaedics and traumatology.

Effects of Hyaluronan on Breast Cancer Aggressiveness

The expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in breast cancer cells is critical for determining tumor aggressiveness and targeting therapies. The presence of such receptors allows for the use of antagonists that effectively reduce breast cancer growth and dissemination. However, the absence of such receptors in triple-negative breast cancer (TNBC) reduces the possibility of targeted therapy, making these tumors very aggressive with a poor outcome. Cancers are not solely composed of tumor cells, but also include several types of infiltrating cells, such as fibroblasts, macrophages, and other immune cells that have critical functions in regulating cancer cell behaviors. In addition to these cells, the extracellular matrix (ECM) has become an important player in many aspects of breast cancer biology, including cell growth, motility, metabolism, and chemoresistance. Hyaluronan (HA) is a key ECM component that promotes cell proliferation and migration in several malignancies. Notably, HA accumulation in the tumor stroma is a negative prognostic factor in breast cancer. HA metabolism depends on the fine balance between HA synthesis by HA synthases and degradation yielded by hyaluronidases. All the different cell types present in the tumor can release HA in the ECM, and in this review, we will describe the role of HA and HA metabolism in different breast cancer subtypes.

Marine Biomaterials: Hyaluronan

The marine-derived hyaluronic acid and other natural biopolymers offer exciting possibilities in the field of biomaterials, providing sustainable and biocompatible alternatives to synthetic materials. Their unique properties and abundance in marine sources make them valuable resources for various biomedical and industrial applications. Due to high biocompatible features and participation in biological processes related to tissue healing, hyaluronic acid has become widely used in tissue engineering applications, especially in the wound healing process. The present review enlightens marine hyaluronan biomaterial providing its sources, extraction process, structures, chemical modifications, biological properties, and biocidal applications, especially for wound healing/dressing purposes. Meanwhile, we point out the future development of wound healing/dressing based on hyaluronan and its composites and potential challenges.

Receptor for hyaluronan-mediated motility (RHAMM) defines an invasive niche associated with tumor progression and predicts poor outcomes in breast cancer patients

Breast cancer invasion and metastasis result from a complex interplay between tumor cells and the tumor microenvironment (TME). Key oncogenic changes in the TME include aberrant synthesis, processing, and signaling of hyaluronan (HA). Hyaluronan-mediated motility receptor (RHAMM, CD168; HMMR) is an HA receptor enabling tumor cells to sense and respond to this aberrant TME during breast cancer progression. Previous studies have associated RHAMM expression with breast tumor progression; however, cause and effect mechanisms are incompletely established. Focused gene expression analysis of an internal breast cancer patient cohort confirmed that increased RHAMM expression correlates with aggressive clinicopathological features. To probe mechanisms, we developed a novel 27-gene RHAMM-related signature (RRS) by intersecting differentially expressed genes in lymph node (LN)-positive patient cases with the transcriptome of a RHAMM-dependent model of cell transformation, which we validated in an independent cohort. We demonstrate that the RRS predicts for poor survival and is enriched for cell cycle and TME-interaction pathways. Further analyses using CRISPR/Cas9-generated RHAMM-/- breast cancer cells provided direct evidence that RHAMM promotes invasion in vitro and in vivo. Immunohistochemistry studies highlighted heterogeneous RHAMM protein expression, and spatial transcriptomics associated the RRS with RHAMM-high microanatomic foci. We conclude that RHAMM upregulation leads to the formation of 'invasive niches', which are enriched in RRS-related pathways that drive invasion and could be targeted to limit invasive progression and improve patient outcomes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Glycocalyx-Sodium Interaction in Vascular Endothelium

The glycocalyx generally covers almost all cellular surfaces, where it participates in mediating cell-surface interactions with the extracellular matrix as well as with intracellular signaling molecules. The endothelial glycocalyx that covers the luminal surface mediates the interactions of endothelial cells with materials flowing in the circulating blood, including blood cells. Cardiovascular diseases (CVD) remain a major cause of morbidity and mortality around the world. The cardiovascular risk factors start by causing endothelial cell dysfunction associated with destruction or irregular maintenance of the glycocalyx, which may culminate into a full-blown cardiovascular disease. The endothelial glycocalyx plays a crucial role in shielding the cell from excessive exposure and absorption of excessive salt, which can potentially cause damage to the endothelial cells and underlying tissues of the blood vessels. So, in this mini review/commentary, we delineate and provide a concise summary of the various components of the glycocalyx, their interaction with salt, and subsequent involvement in the cardiovascular disease process. We also highlight the major components of the glycocalyx that could be used as disease biomarkers or as drug targets in the management of cardiovascular diseases.

Super Enhancer Driven Hyaluronan Synthase 3 Promotes Malignant Progression of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor of the head and neck with high metastatic and invasive nature. Super enhancers (SEs) control the expression of cell identity genes and oncogenes during tumorigenesis. As a glycosaminoglycan in the tumor microenvironment, hyaluronan (HA) is associated with cancer development. High expression of hyaluronan synthase 3 (HAS3) resulted in HA deposition, which promoted the growth of cancer cell. However, its role in NPC development remains elusive. We demonstrated that the levels of HAS3 mRNA or protein were increased in NPC cell lines. Transcription of HAS3 is associated with SE. Disruption of SE by bromodomain containing 4 (BRD4) inhibitor JQ1 resulted in downregulation of HAS3 and inhibition of cell proliferation and invasiveness in NPC cells. Inhibition of HA synthesis by HAS inhibitor 4-MU suppressed cell growth and invasion of NPC cells, whereas HA treatment exerted opposite effects. Genetically silencing HAS3 in HK1 and FaDu NPC cells attenuated cell proliferation and mobility, while re-expression of HAS3 enhanced malignant potential of CNE1 and CNE2 NPC cells. Furthermore, loss of HAS3 impaired metastatic potential of HK1 cells in nude mice. Mechanistically, inhibition of HA synthesis by chemical inhibitor or silencing HAS3 led to reduction of the levels of phosphorylation of EGFR, AKT, and ERK proteins. In contrast, exogenous HA treatment or forced expression of HAS3 activated EGFR/AKT/ERK signaling cascade. This study suggested that HAS3 is driven by SE and overexpressed in NPC. High expression of HAS3 promotes the malignant features of NPC via activation of EGFR/AKT/ERK signaling pathway.

Exploring the Impact of Alginate-PVA Ratio and the Addition of Bioactive Substances on the Performance of Hybrid Hydrogel Membranes as Potential Wound Dressings

Healthcare professionals face an ongoing challenge in managing both acute and chronic wounds, given the potential impact on patients' quality of life and the limited availability of expensive treatment options. Hydrogel wound dressings offer a promising solution for effective wound care due to their affordability, ease of use, and ability to incorporate bioactive substances that enhance the wound healing process. Our study aimed to develop and evaluate hybrid hydrogel membranes enriched with bioactive components such as collagen and hyaluronic acid. We utilized both natural and synthetic polymers and employed a scalable, non-toxic, and environmentally friendly production process. We conducted extensive testing, including an in vitro assessment of moisture content, moisture uptake, swelling rate, gel fraction, biodegradation, water vapor transmission rate, protein denaturation, and protein adsorption. We evaluated the biocompatibility of the hydrogel membranes through cellular assays and performed instrumental tests using scanning electron microscopy and rheological analysis. Our findings demonstrate that the biohybrid hydrogel membranes exhibit cumulative properties with a favorable swelling ratio, optimal permeation properties, and good biocompatibility, all achieved with minimal concentrations of bioactive agents.

Hyaluronan with Different Molecular Weights Can Affect the Gut Microbiota and Pathogenetic Progression of Post-Intensive Care Syndrome Mice in Different Ways

Post-intensive care syndrome (PICS) poses a serious threat to the health of intensive care unit (ICU) survivors, and effective treatment options are currently lacking. With increasing survival rates of ICU patients worldwide, there is a rising interest in developing methods to alleviate PICS symptoms. This study aimed to explore the potential of using Hyaluronan (HA) with different molecular weights as potential drugs for treating PICS in mice. Cecal ligation and puncture (CLP) were used to establish a PICS mice model, and high molecular weight HA (HMW-HA) or oligo-HA were used as therapeutic agents. Pathological and physiological changes of PICS mice in each group were monitored. 16S rRNA sequencing was performed to dissect gut microbiota discrepancies. The results showed that both molecular weights of HA could increase the survival rate of PICS mice at the experimental endpoint. Specifically, 1600 kDa-HA can alleviate PICS in a short time. In contrast, 3 kDa-HA treatment decreased PICS model survivability in the early stages of the experiment. Further, via 16S rRNA sequence analysis, we observed the changes in the gut microbiota in PICS mice, thereby impairing intestinal structure and increasing inflammation. Additionally, both types of HA can reverse this change. Moreover, compared to 1600 kDa-HA, 3 kDa-HA can significantly elevate the proportion of probiotics and reduce the abundance of pathogenic bacteria (Desulfovibrionaceae and Enterobacteriaceae). In conclusion, HA holds the advantage of being a potential therapeutic drug for PICS, but different molecular weights can lead to varying effects. Moreover, 1600 kDa-HA showed promise as a protective agent in PICS mice, and caution should be taken to its timing when considering using 3 kDa-HA.

Atezolizumab Plus PEGPH20 Versus Chemotherapy in Advanced Pancreatic Ductal Adenocarcinoma and Gastric Cancer: MORPHEUS Phase Ib/II Umbrella Randomized Study Platform

BACKGROUND

The MORPHEUS platform comprises multiple open-label, randomized, phase Ib/II trials designed to identify early efficacy and safety signals of treatment combinations across cancers. Atezolizumab (anti-programmed cell death 1 ligand 1 [PD-L1]) was evaluated in combination with PEGylated recombinant human hyaluronidase (PEGPH20).

METHODS

In 2 randomized MORPHEUS trials, eligible patients with advanced, previously treated pancreatic ductal adenocarcinoma (PDAC) or gastric cancer (GC) received atezolizumab plus PEGPH20, or control treatment (mFOLFOX6 or gemcitabine plus nab-paclitaxel [MORPHEUS-PDAC]; ramucirumab plus paclitaxel [MORPHEUS-GC]). Primary endpoints were objective response rates (ORR) per RECIST 1.1 and safety.

RESULTS

In MORPHEUS-PDAC, ORRs with atezolizumab plus PEGPH20 (n = 66) were 6.1% (95% CI, 1.68%-14.80%) vs. 2.4% (95% CI, 0.06%-12.57%) with chemotherapy (n = 42). In the respective arms, 65.2% and 61.9% had grade 3/4 adverse events (AEs); 4.5% and 2.4% had grade 5 AEs. In MORPHEUS-GC, confirmed ORRs with atezolizumab plus PEGPH20 (n = 13) were 0% (95% CI, 0%-24.7%) vs. 16.7% (95% CI, 2.1%-48.4%) with control (n = 12). Grade 3/4 AEs occurred in 30.8% and 75.0% of patients, respectively; no grade 5 AEs occurred.

CONCLUSION

Atezolizumab plus PEGPH20 showed limited clinical activity in patients with PDAC and none in patients with GC. The safety of atezolizumab plus PEGPH20 was consistent with each agent's known safety profile. (ClinicalTrials.gov Identifier: NCT03193190 and NCT03281369).