Interactions between Hyaluronan and Its Receptors (CD44, RHAMM) Regulate the Activities of Inflammation and Cancer

Modification of Extracellular Matrix Enhances Oncolytic Adenovirus Immunotherapy in Glioblastoma

PURPOSE

Extracellular matrix (ECM) component hyaluronan (HA) facilitates malignant phenotypes of glioblastoma (GBM), however, whether HA impacts response to GBM immunotherapies is not known. Herein, we investigated whether degradation of HA enhances oncolytic virus immunotherapy for GBM.

EXPERIMENTAL DESIGN

Presence of HA was examined in patient and murine GBM. Hyaluronidase-expressing oncolytic adenovirus, ICOVIR17, and its parental virus, ICOVIR15, without transgene, were tested to determine if they increased animal survival and modulated the immune tumor microenvironment (TME) in orthotopic GBM. HA regulation of NF-κB signaling was examined in virus-infected murine macrophages. We combined ICOVIR17 with PD-1 checkpoint blockade and assessed efficacy and determined mechanistic contributions of tumor-infiltrating myeloid and T cells.

RESULTS

Treatment of murine orthotopic GBM with ICOVIR17 increased tumor-infiltrating CD8+ T cells and macrophages, and upregulated PD-L1 on GBM cells and macrophages, leading to prolonged animal survival, compared with control virus ICOVIR15. High molecular weight HA inhibits adenovirus-induced NF-κB signaling in macrophages in vitro, linking HA degradation to macrophage activation. Combining ICOVIR17 with anti-PD-1 antibody further extended the survival of GBM-bearing mice, achieving long-term remission in some animals. Mechanistically, CD4+ T cells, CD8+ T cells, and macrophages all contributed to the combination therapy that induced tumor-associated proinflammatory macrophages and tumor-specific T-cell cytotoxicity locally and systemically.

CONCLUSIONS

Our studies are the first to show that immune modulatory ICOVIR17 has a dual role of mediating degradation of HA within GBM ECM and subsequently modifying the immune landscape of the TME, and offers a mechanistic combination immunotherapy with PD-L1/PD-1 blockade that remodels innate and adaptive immune cells.

Hyaluronic Acid-Targeted Stimuli-Sensitive Nanomicelles Co-Encapsulating Paclitaxel and Ritonavir to Overcome Multi-Drug Resistance in Metastatic Breast Cancer and Triple-Negative Breast Cancer Cells

Active targeting and overcoming multi-drug resistance (MDR) can be some of the important attributes of targeted therapy for metastatic breast cancer (MBC) and triple-negative breast cancer (TNBC) treatment. In this study, we constructed a hyaluronic acid (HA)-decorated mixed nanomicelles-encapsulating chemotherapeutic agent paclitaxel (PTX) and P-glycoprotein inhibitor ritonavir (RTV). HA was conjugated to poly (lactide) co-(glycolide) (PLGA) polymer by disulfide bonds (HA-ss-PLGA). HA is a natural ligand for CD44 receptors overexpressed in breast cancer cells. Disulfide bonds undergo rapid reduction in the presence of glutathione, present in breast cancer cells. The addition of RTV can inhibit the P-gp and CYP3A4-mediated metabolism of PTX, thus aiding in reversing MDR and sensitizing the cells toward PTX. An in vitro uptake and cytotoxicity study in MBC MCF-7 and TNBC MDA-MB-231 cell lines demonstrated the effective uptake of the nanomicelles and drug PTX compared to non-neoplastic breast epithelium MCF-12A cells. Interestingly, in vitro potency determination showed a reduction in mitochondrial membrane potential and reactive oxygen species in breast cancer cell lines, indicating effective apoptosis of cancer cells. Thus, stimuli-sensitive nanomicelles along with HA targeting and RTV addition can effectively serve as a chemotherapeutic drug delivery agent for MBC and TNBC.

C1q-HA Matrix Regulates the Local Synthesis of Hyaluronan in Malignant Pleural Mesothelioma by Modulating HAS3 Expression

Simple Summary

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor characterized by poor prognosis due to late diagnosis and the absence of efficient first-line treatments. Hyaluronic acid (HA) and the complement protein C1q represent two pivotal players in the MPM tumor microenvironment by acting in association with effects on cancer cell adhesion, migration and proliferation. The aim of the current study is to prove HA production by MPM primary cells and to understand whether HA metabolism modulation could be considered a potential target for future therapeutic approaches in MPM.

Abstract

Increased hyaluronic acid (HA) production is often associated with cancer progression. In malignant pleural mesothelioma (MPM), HA is found at elevated levels in pleural effusions and sera of patients, and it has been widely debated whether MPM cells are able to produce HA by themselves or through the release of growth factors stimulating other cells. Another key component of the MPM microenvironment is C1q, which can act as a pro-tumorigenic factor favoring cell adhesion, migration and proliferation. The aim of the current study was to prove that MPM primary cells are able to synthesize HA and to inquire the stimulus given by C1q–HA matrix to HA synthesis. We confirmed the presence of a HA coat and cable-like structures around MPM primary cells, as well as an intracellular pool, mainly localized in the cytoplasmic and perinuclear region. After evaluating HA synthase (HAS) enzymes’ basal expression in MPM primary cells, we found that C1q bound to HA was able to impinge upon HA homeostasis by upregulating HAS3 both at the mRNA and the protein levels. High expression of HAS3 has been correlated with a shorter life expectancy in MPM by bioinformatical analysis. These data confirmed that C1q bound to HA may exert pro-tumorigenic activity and identified HAS3 as a potential target in MPM.

Proteolytic Processing of CD44 and Its Implications in Cancer

CD44 is a transmembrane glycoprotein expressed in several healthy and tumor tissues. Modifications in its structure contribute differently to the activity of this molecule. One modification that has provoked interest is the consecutive cleavage of the CD44 extracellular ectodomain by enzymes that belong mainly to the family of metalloproteases. This process releases biologically active substrates, via alternative splice forms of CD44, that generate CD44v3 or v6 isoforms which participate in the transcriptional regulation of genes and proteins associated to signaling pathways involved in the development of cancer. These include the protooncogene tyrosine-protein kinase Src (c-Src)/signal transducer and activator of transcription 3 (STAT3), the epithelial growth factor receptor, the estrogen receptor, Wnt/βcatenin, or Hippo signaling pathways all of which are associated to cell proliferation, differentiation, or cancer progression. Whereas CD44 still remains as a very useful prognostic cell marker in different pathologies, the main topic is that the generation of CD44 intracellular fragments assists the regulation of transcriptional proteins involved in the cell cycle, cell metabolism, and most importantly, the regulation of some stem cell-associated markers.

CD44 and RHAMM expression patterns in the human developing lung

BACKGROUND

The hyaluronan (HA) receptors CD44 and RHAMM (CD168) are involved in cellular proliferation, differentiation, and motility. As previously investigated, HA and RHAMM expression in human neonatal lungs correlates to gestational age (GA) and air content.

METHODS

CD44 immunofluorescence was analyzed in postmortem lung samples from infants (n = 93; 22-41 GA) by digital image analysis together with clinical data, including RHAMM expression, lung air, and HA content by hierarchical clustering.

RESULTS

Five groups were defined according to RHAMM/CD44 expression, GA, and postnatal age (PNA): extremely to very preterm (EVP; 22-31 GA; Groups 1-2), moderately preterm to term (MPT; 31-41 GA; Groups 3-4), and mixed preterm to term (27-40 GA; Group 5). CD44 correlated linearly with RHAMM in MPT (r = 0.600; p < 0.004). In EVP, high CD44 and low RHAMM corresponded with high PNA and lung air content independently of HA and GA (Group 1 vs 2; p < 0.05). In MPT, high and low CD44 corresponded with low and high RHAMM independently of GA, HA, and lung air content (Group 3 vs 4; p < 0.001). No correlation between CD44 and GA/PNA at death was observed.

CONCLUSIONS

A linear correlation between CD44 and RHAMM expression occurs during the late saccular phase of lung development at birth, whereas postnatal influences on CD44 and RHAMM expression in extremely to very preterm infants cannot be excluded.

IMPACT

The interplay between CD44 and RHAMM, two receptors of hyaluronic acid, can be dependent on the lung developmental stage at birth. This is the second study that analyzes the distribution pattern of CD44 in the human lung during development and the first study performed with quantitative analysis of CD44 expression together with RHAMM expression in the human lung. Our results suggest a relationship in a subset of infants between CD44 and RHAMM expression, which appears at birth during the late saccular stage but not during the earlier stages of lung development.

Hyaluronic acid-doxorubicin nanoparticles for targeted treatment of colorectal cancer

Colorectal cancer, common in both men and women, occurs when tumors form in the linings of the colon. Common treatments of colorectal cancer include surgery, chemotherapy, and radiation therapy; however, many colorectal cancer treatments often damage healthy tissues and cells, inducing severe side effects. Conventional chemotherapeutic agents such as doxorubicin (Dox) can be potentially used for the treatment of colorectal cancer; however, they suffer from limited targeting and lack of selectivity. Here, we report that doxorubicin complexed to hyaluronic acid (HA) (HA-Dox) exhibits an unusual behavior of high accumulation in the intestines for at least 24 hr when injected intravenously. Intravenous administrations of HA-Dox effectively preserved the mucosal epithelial intestinal integrity in a chemical induced colon cancer model in mice. Moreover, treatment with HA-Dox decreased the expression of intestinal apoptotic and inflammatory markers. The results suggest that HA-Dox could effectively inhibit the development of colorectal cancer in a safe manner, which potentially be used a promising therapeutic option.

Co-localization and crosstalk between CD44 and RHAMM depend on hyaluronan presentation

CD44 and the receptor for hyaluronic acid-mediated motility (RHAMM) are the main hyaluronan (HA) receptors. They are commonly overexpressed in different cancers activating signaling pathways related to tumor progression, metastasis and chemoresistance. Besides their involvement in signal transduction via interaction with HA, currently, there is a little information about the possible crosstalk between CD44 and RHAMM and the role of HA in this process. In the present work, we used immunocytochemistry combined with Förster resonance energy transfer (FRET) microscopy and co-immunoprecipitation to elucidate the involvement of HA in CD44 and RHAMM expression, co-localization and crosstalk. We studied breast cancer cells lines with different degrees of invasiveness and expression of these receptors in the absence of exogenous HA and compared the data with the results obtained for cultures supplemented with either soluble HA or seeded on substrates with end-on immobilized HA. Our results demonstrated that cells response depends on the HA presentation: CD44/RHAMM complexation was upregulated in all cell lines upon interaction with immobilized HA, but not with its soluble form. Moreover, the results showed that the expression of both CD44 and RHAMM is regulated via interactions with HA indicating cell-specific feedback loop(s) in the signaling cascade.

Hyaluronic acid is a negative regulator of mucosal fibroblast-mediated enhancement of HIV infection

The majority of HIV infections are established through the genital or rectal mucosa. Fibroblasts are abundant in these tissues, and although not susceptible to infection, can potently enhance HIV infection of CD4+ T cells. Hyaluronic acid (HA) is a major component of the extracellular matrix of fibroblasts, and its levels are influenced by the inflammatory state of the tissue. Since inflammation is known to facilitate HIV sexual transmission, we investigated the role of HA in genital mucosal fibroblast-mediated enhancement of HIV infection. Depletion of HA by CRISPR-Cas9 in primary foreskin fibroblasts augmented the ability of the fibroblasts to increase HIV infection of CD4+ T cells. This amplified enhancement required direct contact between the fibroblasts and CD4+ T cells, and could be attributed to both increased rates of trans-infection and the increased ability of HA-deficient fibroblasts to push CD4+ T cells into a state of higher permissivity to infection. This HIV-permissive state was characterized by differential expression of genes associated with regulation of cell metabolism and death. Our results suggest that conditions resulting in diminished cell-surface HA on fibroblasts, such as genital inflammation, can promote HIV transmission by conditioning CD4+ T cells toward a state more vulnerable to infection by HIV.

A modular, injectable, non-covalently assembled hydrogel system features widescale tunable degradability for controlled release and tissue integration

Biomaterials with attenuated adverse host tissue reactions, and meanwhile, combining biocompatibility with mimicry of mechanical and biochemical cues of native extracellular matrices (ECM) to promote integration and regeneration of tissues are important for many biomedical applications. Further, the materials should also be tailorable to feature desired application-related functions, like tunable degradability, injectability, or controlled release of bioactive molecules. Herein, a non-covalently assembled, injectable hydrogel system based on oligopeptides interacting with sulphated polysaccharides is reported, showing high tolerability and biocompatibility in immunocompetent hairless mice. Altering the peptide or polysaccharide component considerably varies the in vivo degradation rate of the hydrogels, ranging from a half-life of three weeks to no detectable degradation after three months. The hydrogel with sulphated low molecular weight hyaluronic acid exhibits sustained degradation-mediated release of heparin-binding molecules in vivo, as shown by small animal magnetic resonance imaging and fluorescence imaging, and enhances the expression of vascular endothelial growth factor in hydrogel surrounding. In vitro investigations indicate that M2-macrophages could be responsible for the moderate difference in pro-angiogenic effects. The ECM-mimetic and injectable hydrogels represent tunable bioactive scaffolds for tissue engineering, also enabling controlled release of heparin-binding signalling molecules including many growth factors.

Hold on or Cut? Integrin- and MMP-Mediated Cell-Matrix Interactions in the Tumor Microenvironment

The tumor microenvironment (TME) has become the focus of interest in cancer research and treatment. It includes the extracellular matrix (ECM) and ECM-modifying enzymes that are secreted by cancer and neighboring cells. The ECM serves both to anchor the tumor cells embedded in it and as a means of communication between the various cellular and non-cellular components of the TME. The cells of the TME modify their surrounding cancer-characteristic ECM. This in turn provides feedback to them via cellular receptors, thereby regulating, together with cytokines and exosomes, differentiation processes as well as tumor progression and spread. Matrix remodeling is accomplished by altering the repertoire of ECM components and by biophysical changes in stiffness and tension caused by ECM-crosslinking and ECM-degrading enzymes, in particular matrix metalloproteinases (MMPs). These can degrade ECM barriers or, by partial proteolysis, release soluble ECM fragments called matrikines, which influence cells inside and outside the TME. This review examines the changes in the ECM of the TME and the interaction between cells and the ECM, with a particular focus on MMPs.

Retinal and Lens Degeneration in New Zealand White Rabbits Administered Intravitreal TSG-6 Link Domain-Rabbit FAb Fusion Proteins

Fusion of biologic therapeutics to hyaluronic acid binding proteins, such as the link domain (LD) of Tumor necrosis factor (TNF)-Stimulated Gene-6 (TSG-6), is expected to increase vitreous residence time following intravitreal injection and provide for long-acting delivery. The toxicity of a single intravitreal dose of free TSG-6-LD and fusion proteins of TSG-6-LD and a nonbinding rabbit antibody fragment (RabFab) were assessed in New Zealand White rabbits. Animals administered free TSG-6-LD exhibited extensive lens opacities and variable retinal vascular attenuation, correlated with microscopic findings of lens and retinal degeneration. Similar but less severe findings were present in animals dosed with the RabFab-TSG-6-LD fusion proteins. In-life ocular inflammation was noted in all animals from 7-days postdose and was associated with high anti-RabFab antibody titers in animals administered fusion proteins. Inflammation and retinal degeneration were multifocally associated with evidence of retinal detachment, and hypertrophy and migration of vimentin, glial fibrillary acidic protein, and glutamine synthetase positive Müller cells to the outer nuclear layer. Further assessment of alternative hyaluronic acid binding protein fusions should consider the potential for retinal degeneration and enhanced immune responses early in development.

Effects of the Molecular Weight of Hyaluronic Acid in a Carbon Nanotube Drug Delivery Conjugate

Hyaluronic acid (HA) is a ubiquitous biopolymer involved in many pathophysiological roles. One HA receptor, the cluster of differentiation CD44 protein, is often overexpressed in tumor cells. As such, HA has attracted considerable interest in the development of drug delivery formulations, given its intrinsic targetability toward CD44 overexpressing cells. The present study is focused on examining the correlation of HA molecular weight with its targetability properties. A library of conjugates obtained by linking the amino group of the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) to the carboxylic residues of HA of different molecular weight (6.4, 17, 51, 200, and 1,500 kDa) were synthesized and fully characterized. The HA-DMPE conjugates were then used to non-covalently functionalize the highly hydrophobic single-walled carbon nanotubes (CNT), and further encapsulate the anticancer drug doxorubicin (DOX). Our results show that the complexes DOX/CNT/HA-DMPE maintain very good and stable dispersibility. Drug release studies indicated a pH-responsive release of the drug from the nanocarrier. Cell viability tests demonstrated that all HA modified CNTs have good biocompatibility, and specific targeting toward cells overexpressing the CD44 receptor. Among all the molecular weights tested, the 200 kDa HA showed the highest increase in cellular uptake and cytotoxic activity. All these promising attributes make CNT/HA₂₀₀-DMPE a “smart” platform for tumor-targeted delivery of anticancer agents.

A bird's eye view of the advanced approaches and strategies for overshadowing triple negative breast cancer

Triple negative breast cancer (TNBC) is one of the most aggressive form of breast cancer. It is characterized by the absence of estrogen, progesterone and human epidermal growth factor receptors. The main issue with TNBC is that it exhibits poor prognosis, high risk of relapse, short progression-free survival and low overall survival in patients. This is because the conventional therapy used for managing TNBC has issues pertaining to poor bioavailability, lower cellular uptake, increased off-target effects and development of resistance. To overcome such pitfalls, several other approaches are explored. In this context, the present manuscript showcases three of the most widely used approaches which are (i) nanotechnology-based approach; (ii) gene therapy approach and (iii) Phytochemical-based approach. The ultimate focus is to present and explain the insightful reports based on these approaches. Further, the review also expounds on the identified molecular targets and novel targeting ligands which are explored for managing TNBC effectively. Thus, in a nutshell, the review tries to highlight these existing treatment approaches which might inspire for future development of novel therapies with a potential of overshadowing TNBC.

Natural Polysaccharide Carriers in Brain Delivery: Challenge and Perspective

Targeted drug delivery systems represent valuable tools to enhance the accumulation of therapeutics in the brain. Here, the presence of the blood brain barrier strongly hinders the passage of foreign substances, often limiting the effectiveness of pharmacological therapies. Among the plethora of materials used for the development of these systems, natural polysaccharides are attracting growing interest because of their biocompatibility, muco-adhesion, and chemical versatility which allow a wide range of carriers with tailored physico-chemical features to be synthetized. This review describes the state of the art in the field of targeted carriers based on natural polysaccharides over the last five years, focusing on the main targeting strategies, namely passive and active transport, stimuli-responsive materials and the administration route. In addition, in the last section, the efficacy of the reviewed carriers in each specific brain diseases is summarized and commented on in terms of enhancement of either blood brain barrier (BBB) permeation ability or drug bioavailability in the brain.

Repurposing of Fluvastatin as an Anticancer Agent against Breast Cancer Stem Cells via Encapsulation in a Hyaluronan-Conjugated Liposome

Fluvastatin (FLUVA), which is a common anti-hypercholesterolemia drug, exhibits potential anticancer activity as it suppresses the proliferation, angiogenesis, and metastasis of breast cancer cells via inhibiting 3-hydroxy-methyl glutaryl-coenzyme A (HMG-CoA) reductase. In this study, hyaluronan-conjugated FLUVA-encapsulating liposomes (HA-L-FLUVA) were evaluated for their anticancer efficacy in vitro and in vivo. The particle size, zeta potential, and encapsulation efficiency of HA-L-FLUVA were 158.36 ± 1.78 nm, −24.85 ± 6.26 mV, and 35%, respectively. Growth inhibition of breast cancer stem cells (BCSCs) by HA-L-FLUVA was more effective than that by free FLUVA. The half maximal inhibitory concentration (IC₅₀) values of FLUVA, L-FLVUA, and HA-L-FLUVA were 0.16, 0.17, and 0.09 μM, respectively. The in vivo anticancer effect of HA-L-FLUVA in combination with doxorubicin (DOX) was more effective than that of free FLUVA, free DOX, and HA-L-FLUVA. The longest survival of mice was achieved by treatment with FLUVA (15 mg/kg) and HA-L-FLUVA (15 mg/kg) + DOX (3 mg/kg), followed by HA-L-FLUVA (15 mg/kg), Dulbecco’s phosphate buffered saline, and DOX (3 mg/kg). No more than 10% body weight loss was observed in the mice injected with FLUVA, indicating that the drug was not toxic. Taken together, these results indicate that HA-L-FLUVA could serve as an effective anticancer drug by inhibiting the growth of both breast cancer cells and cancer stem cells.

Layer-by-layer pH-sensitive nanoparticles for drug delivery and controlled release with improved therapeutic efficacy in vivo

In this work, a pH-sensitive liposome-polymer nanoparticle (NP) composed of lipid, hyaluronic acid (HA) and poly(β-amino ester) (PBAE) was prepared using layer-by-layer (LbL) method for doxorubicin (DOX) targeted delivery and controlled release to enhance the cancer treatment efficacy. The NP with pH-sensitivity and targeting effect was successfully prepared by validation of charge reversal and increase of hydrodynamic diameter after each deposition of functional layer. We further showed the DOX-loaded NP had higher drug loading capacity, suitable particle size, spherical morphology, good uniformity, and high serum stability for drug delivery. We confirmed that the drug release profile was triggered by low pH with sustained release manner in vitro. Confocal microscopy research demonstrated that the NP was able to effectively target and deliver DOX into human non-small cell lung carcinoma (A549) cells in comparison to free DOX. Moreover, the blank NP showed negligible cytotoxicity, and the DOX-loaded NP could efficiently induce the apoptosis of A549 cells as well as free DOX. Notably, in vivo experiment results showed that the DOX-loaded NPs effectively inhibited the growth of tumor, enhanced the survival of tumor-bearing mice and improved the therapeutic efficacy with reduced side-effect comparing with free drug. Therefore, the NP could be a potential intelligent anticancer drug delivery carrier for cancer chemotherapy, and the LbL method might be a useful strategy to prepare multi-functional platform for drug delivery.

Function-Blocking RHAMM Peptides Attenuate Fibrosis and Promote Antifibrotic Adipokines in a Bleomycin-Induced Murine Model of Systemic Sclerosis

Systemic sclerosis a chronic, fibrotic disorder associated with high disease-specific mortality and morbidity. Cutaneous manifestations include dermal thickening and obliteration of dermal adipose tissue. Accumulation of low-molecular-weight hyaluronan, which signals through the receptor for hyaluronan-mediated motility, RHAMM, leads to progressive fibrosis and is correlated with increased severity of systemic sclerosis. The purpose of this study is to test the efficacy of two function-blocking RHAMM peptides, NPI-110 and NPI-106, in reducing skin fibrosis in a bleomycin-induced mouse model of systemic sclerosis. NPI-110 reduced visible measures of fibrosis (dermal thickness and collagen production, deposition, and organization) and profibrotic gene expression (Tgfb1, c-Myc, Col1a1, Col3a1). NPI-110 treatment also increased the expression of the antifibrotic adipokines perilipin and adiponectin. Both RHAMM peptides strongly reduced dermal RHAMM expression, predicting that dermal fibroblasts are peptide targets. Transcriptome and cell culture analyses using Rhamm-/- and Rhamm-rescued dermal fibroblasts reveal a TGFβ1/RHAMM/MYC signaling axis that promotes fibrogenic gene expression and myofibroblast differentiation. RHAMM function‒blocking peptides suppress this signaling and prevent TGFβ1-induced myofibroblast differentiation. These results suggest that inhibiting RHAMM signaling will offer a treatment method for cutaneous fibrosis in systemic sclerosis.

Bovine seminal plasma osteopontin: Structural modelling, recombinant expression and its relationship with semen quality

Osteopontin (OPN) is a multifunctional phosphoprotein that has been linked to fertility in bulls. However, the exact mechanism by which OPN contributes to fertilisation is yet unknown. The biotechnological use of OPN in bovine reproduction is promising but some gaps remain unfilled. The present work aimed: (a) to verify whether the seminal plasma OPN is associated with seminal traits and a standard breeding soundness exam; (b) to predict OPN interactions with integrins, CD44 and glycosaminoglycans through molecular docking; and (c) to develop a protocol for recombinant expression of OPN from vesicular gland cDNA. Ejaculates from top ranked bulls had higher amounts of seminal plasma OPN in comparison with bulls classified as questionable (p < .01). The structural modelling and molecular docking predictions indicated that bovine OPN binds to heparin disaccharide, hyaluronic acid and hyaluronan. In addition, docking studies described the binding complexes of OPN with CD44 and the integrin heterodimers α5β1 and αVβ3. Finally, expression of rOPN-6His was successfully obtained after 3 hr of induction with 0.5 mM IPTG at 37°C and a denaturing purification protocol resulted in efficiently purified recombinant OPN. The present results contribute to the development of biotechnological uses of OPN as a biomarker in bovine reproduction.

Eradicating the Roots: Advanced Therapeutic Approaches Targeting Breast Cancer Stem Cells

Accumulating evidences have demonstrated that the existence of breast cancer-initiating cells, which drives the original tumorigenicity, local invasion and migration propensity of breast cancer. These cells, termed as breast cancer stem cells (BCSCs), possess properties including self-renewal, multidirectional differentiation and proliferative potential, and are believed to play important roles in the intrinsic drug resistance of breast cancer. One of the reasons why BCBCs cause difficulties in breast cancer treating is that BCBCs can control both genetic and non-genetic elements to keep their niches safe and sound, which allows BCSCs for constant self-renewal and differentiation. Therapeutic strategies designed to target BCSCs may ultimately result in effective interventions for the treatment of breast cancer. Novel strategies including nanomedicine, oncolytic virus therapy, immunotherapy and induced differentiation therapy are emerging and proved to be efficient in anti-BCSCs therapy. In this review, we summarized breast tumor biology and the current challenges of breast cancer therapies, focused on breast cancer stem cells, and introduced promising therapeutic strategies targeting BCSCs.

pH-responsive hyaluronic acid-based nanoparticles for targeted curcumin delivery and enhanced cancer therapy

Curcumin (CUR) display promising antitumor effects, however, the poor water solubility severely limited its clinical application. To overcome this problem, polymeric nanocarriers have been adopted for targeted CUR delivery and enhanced cancer therapy. In this paper, utilizing an acid-labile hydrazone linkage, hydrophobic CUR was conjugated with hydrophilic hyaluronic acid (HA) to form amphiphilic HA-ADH-CUR conjugates, which could subsequently self-assemble to form nanoparticles (HA@CUR NPs) in aqueous. The in vitro drug release experiments showed that HA@CUR NPs exhibited a pH-responsive CUR release behavior, and the release rate of CUR was 73.5 % in pH 5.0. Further, in vitro cell experiments showed HA@CUR NPs could be efficiently internalized by 4T1 and MCF-7 cancer cells through CD44 receptor mediated endocytosis and successfully release CUR in acidic lysosome environment for chemotherapy. In vivo antitumor experiments showed that, compared to free CUR, HA@CUR NPs could efficiently cumulate in tumor site via EPR effect and CD44 mediated endocytosis, achieve superior therapeutic effect for tumor growth suppression. Therefore, HA@CUR NPs were a highly promising nanocarrier for hydrophobic CUR to realize enhanced cancer therapy with good biosafety.

Cancer Extracellular Matrix Proteins Regulate Tumour Immunity

The extracellular matrix (ECM) plays an increasingly recognised role in the development and progression of cancer. Whilst significant progress has been made in targeting aspects of the tumour microenvironment such as tumour immunity and angiogenesis, there are no therapies that address the cancer ECM. Importantly, immune function relies heavily on the structure, physics and composition of the ECM, indicating that cancer ECM and immunity are mechanistically inseparable. In this review we highlight mechanisms by which the ECM shapes tumour immunity, identifying potential therapeutic targets within the ECM. These data indicate that to fully realise the potential of cancer immunotherapy, the cancer ECM requires simultaneous consideration.

Current advances in the nano-delivery of celastrol for treating inflammation-associated diseases

Inflammation is ubiquitous in the body, and uncontrolled inflammation often contributes to various diseases. Celastrol, a compound isolated from a Chinese medicinal herb, holds great potential in treating multiple inflammation-associated diseases. However, its further clinical use is limited by its poor solubility, bioavailability, and high organ toxicity. With the advancement of nanotechnology, the nano-delivery of celastrol can effectively improve its oral bioavailability, maximize its efficacy and minimize its side effects. Here, we summarize the roles of celastrol in the treatment of various inflammation-associated diseases, with a special emphasis on its role in modulating immune cell signaling or non-immune cell signaling within the inflammatory microenvironment, and we highlight the latest advances in nano-delivery strategies for celastrol to treat diseases associated with inflammation.

Identification of Common Differentially Expressed Genes and Potential Therapeutic Targets in Ulcerative Colitis and Rheumatoid Arthritis

Ulcerative colitis (UC) and rheumatoid arthritis (RA) are immune-mediated inflammatory diseases (IMIDs) with similar symptoms and common genomics. However, the relationship between UC and RA has not been investigated thoroughly. Therefore, this study aimed to establish the differentially expressed genes (DEGs) and potential therapeutic targets in UC and RA. Three microarray datasets (GSE38713, GSE1919, and GSE12251) were selected from the Gene Expression Omnibus (GEO) database for analysis. We used R software to identify the DEGs and performed enrichment analyses. Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape software were used to construct the protein-protein interaction (PPI) network and identify the hub genes. A regulatory network based on the constructed PPI was generated using StarBase and PROMO databases. We identified a total of 1542 and 261 DEGs in UC and RA. There were 169 common DEGs identified in both UC and RA, including 63 upregulated genes (DEGs1) and nine downregulated genes (DEGs2). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of DEGs1 and DEGs2 in the PPI network revealed that the genes enriched were involved in immunity. A total of 45 hub genes were selected based on high scores of correlation; three hub genes (SRGN, PLEK, and FCGR3B) were found to be upregulated in UC and RA, and downregulated in UC patients with response to infliximab treatment. The identification of novel DEGs and hub genes in the current study contributes to a novel perception for latent functional mechanisms and presents potential prognostic indicators and therapeutic targets in UC and RA.

Hyaluronan: Metabolism and Function

As a major polysaccharide component of the extracellular matrix, hyaluronan plays essential roles in the organization of tissue architecture and the regulation of cellular functions, such as cell proliferation and migration, through interactions with cell-surface receptors and binding molecules. Metabolic pathways for biosynthesis and degradation tightly control the turnover rate, concentration, and molecular size of hyaluronan in tissues. Despite the relatively simple chemical composition of this polysaccharide, its wide range of molecular weights mediate diverse functions that depend on molecular size and tissue concentration. Genetic engineering and pharmacological approaches have demonstrated close associations between hyaluronan metabolism and functions in many physiological and pathological events, including morphogenesis, wound healing, and inflammation. Moreover, emerging evidence has suggested that the accumulation of hyaluronan extracellular matrix and fragments due to the altered expression of hyaluronan synthases and hyaluronidases potentiates cancer development and progression by remodeling the tumor microenvironment. In addition to the well-known functions exerted by extracellular hyaluronan, recent metabolomic approaches have also revealed that its synthesis can regulate cellular functions via the reprogramming of cellular metabolism. This review highlights the current advances in knowledge on the biosynthesis and catabolism of hyaluronan and describes the diverse functions associated with hyaluronan metabolism.

The Labeling, Visualization, and Quantification of Hyaluronan Distribution in Tumor-Bearing Mouse Using PET and MR Imaging

PURPOSE

Hyaluronan (HA) based biomaterials are widely used as tissue scaffolds, drug formulations, as well as targeting ligands and imaging probes for diagnosis and drug delivery. However, because of the presence of abundant endogenous HA presented in various tissues in vivo, the pharmacokinetic behavior and biodistribution patterns of exogenously administered HAs have not been well characterized.

METHODS

The HA backbone was modified with Diethylenetriamine (DTPA) to enable the chelation of gadolinium (Gd) and aluminum (Al) ions. Series of PET and MR imaging were taken after the injection of HA-DTPA-Gd and HA-DTPA-Al¹⁸F while using¹⁸F-FDG and Magnevist(DTPA-Gd) as controls. The Tomographic images were analyzed and quantified to reveal the distribution and locations of HA in tumor-bearing mice.

RESULTS

The labeled HAs had good stability in plasma. They retained binding affinity towards CD44s on tumor cell surface. The injected HAs distributed widely in various organs, but were found to be cleared quickly except inside tumor tissues where the signals were higher and persisted longer.

CONCLUSION

Medical imaging tools, including MR and PET, can be highly valuable for examining biomaterial distribution non-invasively. The HA tumor accumulation properties may be explored for the development of active targeting drug carriers and molecular probes.

Beyond just a tight fortress: contribution of stroma to epithelial-mesenchymal transition in pancreatic cancer

Novel effective treatment is direly needed for patients with pancreatic ductal adenocarcinoma (PDAC). Therapeutics that target the driver mutations, especially the KRAS oncoprotein and its effector cascades, have been ineffective. It is increasing clear that the extensive fibro-inflammatory stroma (or desmoplasia) of PDAC plays an active role in the progression and therapeutic resistance of PDAC. The desmoplastic stroma is composed of dense extracellular matrix (ECM) deposited mainly by the cancer-associated-fibroblasts (CAFs) and infiltrated with various types of immune cells. The dense ECM functions as a physical barrier that limits tumor vasculatures and distribution of therapeutics to PDAC cells. In addition, mounting evidence have demonstrated that both CAFs and ECM promote PDAC cells aggressiveness through multiple mechanisms, particularly engagement of the epithelial-mesenchymal transition (EMT) program. Acquisition of a mesenchymal-like phenotype renders PDAC cells more invasive and resistant to therapy-induced apoptosis. Here, we critically review seminal and recent articles on the signaling mechanisms by which each stromal element promotes EMT in PDAC. We discussed the experimental models that are currently employed and best suited to study EMT in PDAC, which are instrumental in increasing the chance of successful clinical translation.

Natural and Synthetic Biomaterials for Engineering Multicellular Tumor Spheroids

The lack of in vitro models that represent the native tumor microenvironment is a significant challenge for cancer research. Two-dimensional (2D) monolayer culture has long been the standard for in vitro cell-based studies. However, differences between 2D culture and the in vivo environment have led to poor translation of cancer research from in vitro to in vivo models, slowing the progress of the field. Recent advances in three-dimensional (3D) culture have improved the ability of in vitro culture to replicate in vivo conditions. Although 3D cultures still cannot achieve the complexity of the in vivo environment, they can still better replicate the cell-cell and cell-matrix interactions of solid tumors. Multicellular tumor spheroids (MCTS) are three-dimensional (3D) clusters of cells with tumor-like features such as oxygen gradients and drug resistance, and represent an important translational tool for cancer research. Accordingly, natural and synthetic polymers, including collagen, hyaluronic acid, Matrigel^®, polyethylene glycol (PEG), alginate and chitosan, have been used to form and study MCTS for improved clinical translatability. This review evaluates the current state of biomaterial-based MCTS formation, including advantages and disadvantages of the different biomaterials and their recent applications to the field of cancer research, with a focus on the past five years.

Characteristics of Molecularly Engineered Anticancer Drug Conjugated Organic Nanomicelles for Site-Selective Cancer Cell Rupture and Growth Inhibition of Tumor Spheroids

Site-selective uptake and specific biodistribution of chemotherapeutic drugs are essential prerequisites for targeted cancer therapy. Especially, antibody and peptide conjugated drugs have been attempted as localized therapeutic agents. However, the characteristics of drug conjugated nanosystems are less explored, which are limited with their toxicity, low therapeutic efficacy, complicated synthesis, and high costs. Herein, we report a biocompatible (about 95%) molecularly engineered anticancer drug conjugated nanomicelles (∼200 nm in size) for site-selective CD44 overexpressed cancer cell rupture and tumor growth inhibition. Microscopic analysis demonstrates the distinct visualization of organic-organic interfaces (∼5 nm), which are corroborated with spectroscopic measurements confirmed the conjugation of niclosamide drug with hyaluronic acid (NIC-HA). Uniformly distributed hemocompatible (about 99%) organic nanomicelles exhibit the cellular membrane and cytoplasmic targeting with significant cellular rupture (IC₅₀ of 4 μM for MDA MB 231 cells) indicating their inherent targeting ability for cancer cells and cancer stem cells. An inclusive in vitro and in vivo analysis for targeted antitumor activity (HT1080 tumor xenograft model) of NIC-HA nanoconjugates (∼24.6% loading) exhibited promising cancer cell death and tumor growth inhibition (60%, p < 0.05) due to STAT-3 signaling pathway inhibition and induction of apoptosis in CD44-positive triple negative breast cancer cells.

Multilayer platform to model the bioactivity of hyaluronic acid in gastric cancer

Hyaluronic acid (HA) has a key role in cancer progression. The HA's molecular weight (M_w) is altered in this pathological state: increased concentration of shorter fragments due to the overexpressed hyaluronidases and ROS. Aiming to mimic this microenvironment, we developed a Layer-by-Layer (LbL) platform presenting HA of different M_ws, namely 6.4, 752 and 1500 kDa, to study the influence of HA M_w on the formation of focal adhesion sites (FAs), and the involvement of paxillin and CD44 in this process. High paxillin expression and formation of FAs, via CD44, is observed for MKN45 cells seeded on LbLs presenting HA 6.4 kDa, with the activation of the ERK1/2 pathway, responsible for cell motility and tumour progression. In contrast, activation of p38 pathway, usually related with cancer latency, is observed for cells seeded on LbLs with high M_w HA, i.e. 1500 kDa. Overall, we demonstrate the suitability of the developed platform to study cancer invasiveness.

Hyaluronic Acid of Low Molecular Weight Triggers the Invasive "Hummingbird" Phenotype on Gastric Cancer Cells

The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layer-by-layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HA-rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the "hummingbird" morphology, promote high cellular motility, and activate signaling pathways with increased expression of p-ERK1/2 and p-AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.

Zika Virus Nonstructural Protein 1 Disrupts Glycosaminoglycans and Causes Permeability in Developing Human Placentas

BACKGROUND

During pregnancy, the Zika flavivirus (ZIKV) infects human placentas, inducing defects in the developing fetus. The flavivirus nonstructural protein 1 (NS1) alters glycosaminoglycans on the endothelium, causing hyperpermeability in vitro and vascular leakage in vivo in a tissue-dependent manner. The contribution of ZIKV NS1 to placental dysfunction during ZIKV infection remains unknown.

METHODS

We examined the effect of ZIKV NS1 on expression and release of heparan sulfate (HS), hyaluronic acid (HA), and sialic acid on human trophoblast cell lines and anchoring villous explants from first-trimester placentas infected with ZIKV ex vivo. We measured changes in permeability in trophoblasts and stromal cores using a dextran-based fluorescence assay and changes in HA receptor expression using immunofluorescent microscopy.

RESULTS

ZIKV NS1 in the presence and absence of ZIKV increased the permeability of anchoring villous explants. ZIKV NS1 induced shedding of HA and HS and altered expression of CD44 and lymphatic endothelial cell HA receptor-1, HA receptors on stromal fibroblasts and Hofbauer macrophages in villous cores. Hyaluronidase was also stimulated in NS1-treated trophoblasts.

CONCLUSIONS

These findings suggest that ZIKV NS1 contributes to placental dysfunction via modulation of glycosaminoglycans on trophoblasts and chorionic villi, resulting in increased permeability of human placentas.

Precision Therapy of Pancreatic Cancer: From Bench to Bedside

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), with a mortality rate of 94% and a 5-year-survival rate of only 8%, is one of the deadliest cancer entities worldwide, and early diagnostic methods as well as effective therapies are urgently needed.

SUMMARY

This review summarizes current clinical procedure and recent developments of oncological therapy in the palliative setting of metastatic PDAC. It further gives examples of successful, as well as failed, targeted therapy approaches and finally discusses promising ongoing research into the decade-old question of the "undruggability" of KRAS.

KEY MESSAGES

Bench-driven concepts change the clinical landscape from "one size fits all" towards precision medicine. With growing insight into the molecular mechanisms of pancreatic cancer the era of targeted therapy in PDAC is gaining a new momentum.

Developmental role of hyaluronic acid and its application in salivary gland tissue engineering

Dry mouth, or xerostomia, caused by salivary gland dysfunction significantly impacts oral/systemic health and quality of life. Although in vitro-generated artificial salivary glands have been considered as the fundamental solution, its structural complexity is difficult to reproduce using current biomaterials. Therefore, understanding and recapitulating the roles of biomacromolecules in salivary gland organogenesis is needed to solve these problems. Hyaluronic acid (HA) is a macromolecule abundant during salivary gland organogenesis, but its role remains unknown. Here, we verify the effects of HA on salivary gland organogenesis and artificial organ germ formation in solubilized and substrate-immobilized forms. In embryonic submandibular glands (eSMG), we found dense HA layers encapsulating proliferative c-Kit+ progenitor cells that were expressing CD44, an HA receptor. The blockage of HA synthesis, or degradation of HA, impaired eSMG growth by ablating the c-Kit+ progenitor cell population. We also found that high-molecular-weight (HMW) HA has a significant role in eSMG growth. Based on these findings, we discovered that HA is also crucial for in vitro formation of salivary gland organ germs, one of the most promising candidates for salivary gland tissue regeneration. We significantly enhanced salivary gland organ germ formation by supplementing HMW HA in solution; this effect was further increased when the HMW HA was immobilized on the substrate by polydopamine/HA co-immobilization. Our study suggests that the current use of HA in salivary gland tissue engineering can be further optimized.

The microvascular extracellular matrix in brains with Alzheimer's disease neuropathologic change (ADNC) and cerebral amyloid angiopathy (CAA)

BACKGROUND

The microvasculature (MV) of brains with Alzheimer's disease neuropathologic change (ADNC) and cerebral amyloid angiopathy (CAA), in the absence of concurrent pathologies (e.g., infarctions, Lewy bodies), is incompletely understood.

OBJECTIVE

To analyze microvascular density, diameter and extracellular matrix (ECM) content in association with ADNC and CAA.

METHODS

We examined samples of cerebral cortex and isolated brain microvasculature (MV) from subjects with the National Institute on Aging-Alzheimer's Association (NIA-AA) designations of not-, intermediate-, or high ADNC and from subjects with no CAA and moderate-severe CAA. Cases for all groups were selected with no major (territorial) strokes, ≤ 1 microinfarct in screening sections, and no Lewy body pathology. MV density and diameter were measured from cortical brain sections. Levels of basement membrane (BM) ECM components, the protein product of TNF-stimulated gene-6 (TSG-6), and the ubiquitous glycosaminoglycan hyaluronan (HA) were assayed by western blots or HA ELISA of MV lysates.

RESULTS

We found no significant changes in MV density or diameter among any of the groups. Levels of BM laminin and collagen IV (col IV) were lower in MV isolated from the high ADNC vs. not-ADNC groups. In contrast, BM laminin was significantly higher in MV from the moderate-severe CAA vs. the no CAA groups. TSG-6 and HA content were higher in the presence of both high ADNC and CAA, whereas levels of BM fibronectin and perlecan were similar among all groups.

CONCLUSIONS

Cortical MV density and diameter are not appreciably altered by ADNC or CAA. TSG-6 and HA are increased in both ADNC and CAA, with laminin and col IV decreased in the BM of high ADNC, but laminin increased in moderate-severe CAA. These results show that changes in the ECM occur in AD and CAA, but independently of one another, and likely reflect on the regional functioning of the brain microvasculature.

The Glycocalyx and Its Role in Vascular Physiology and Vascular Related Diseases

Purpose

In 2007 the two senior authors wrote a review on the structure and function of the endothelial glycocalyx layer (Weinbaum in Annu Rev Biomed Eng 9:121–167, 2007). Since then there has been an explosion of interest in this hydrated gel-like structure that coats the luminal surface of endothelial cells that line our vasculature due to its important functions in (A) basic vascular physiology and (B) vascular related diseases. This review will highlight the major advances that have occurred since our 2007 paper.

Methods

A literature search mainly focusing on the role of the glycocalyx in the two major areas described above was performed using electronic databases.

Results

In part (A) of this review, the new formulation of the century old Starling principle, now referred to as the Michel–Weinbaum glycoclayx model or revised Starling hypothesis, is described including new subtleties and physiological ramifications. New insights into mechanotransduction and release of nitric oxide due to fluid shear stress sensed by the glycocalyx are elaborated. Major advances in understanding the organization and function of glycocalyx components, and new techniques for measuring both its thickness and spatio-chemical organization based on super resolution, stochastic optical reconstruction microscopy (STORM) are presented. As discussed in part (B) of this review, it is now recognized that artery wall stiffness associated with hypertension and aging induces glycocalyx degradation, endothelial dysfunction and vascular disease. In addition to atherosclerosis and cardiovascular diseases, the glycocalyx plays an important role in lifestyle related diseases (e.g., diabetes) and cancer. Infectious diseases including sepsis, Dengue, Zika and Corona viruses, and malaria also involve the glycocalyx. Because of increasing recognition of the role of the glycocalyx in a wide range of diseases, there has been a vigorous search for methods to protect the glycocalyx from degradation or to enhance its synthesis in disease environments.

Conclusion

As we have seen in this review, many important developments in our basic understanding of GCX structure, function and role in diseases have been described since the 2007 paper. The future is wide open for continued GCX research.

Hyaluronic acid containing scaffolds ameliorate stem cell function for tissue repair and regeneration

Recent evidence based studies have proposed hyaluronic acid (HA) as an emerging biopolymer for various tissue engineering application. Meanwhile, stem cells (SCs) have also gained immense popularity for their tissue regenerative capacity. Thus, combining HA and stem cells for tissue engineering application have shown to foster tissue repair and regeneration process. HA possesses the ability to interact with SCs via cellular surface receptors along with the capacity to elicit the process of differentiation. The influence of HA on stem cells has been widely investigated in cartilage and bone repair but their properties of reducing inflammation has also been explored in various other tissue repair processes. In this review, we have provided an insight to the effect of crosslinked and non-crosslinked HA on various stem cells. Further, HA based scaffolds combined with stem cells have shown to have a synergistic effect in the regeneration capacity. Also, various chemically modified HA and biomolecules conjugated HA as a suitable carrier or matrix for stem cells delivery and the effect of HA in fine tuning the stem cells function is discussed.

High molecular weight form of hyaluronic acid reduces neuroinflammatory response in injured sciatic nerve via the intracellular domain of CD44

Inflammatory response after peripheral nerve injury is required for clearance of tissue debris and effective regeneration. Studies have revealed that hyaluronic acid (HA) may exert different properties depending on their molecular size. High molecular weight HA (>>1,000 kDa; HMW-HA) displays immunosuppressive properties, whereas low molecular weight HA (<800 kDa; LMW-HA) induces proinflammatory responses. The role of HMW-HA interaction with CD44, a major HA receptor, in neuroinflammatory responses has not been fully elucidated. The purpose of this experimental study was to investigate the effects of topical applications of HMW-HA on the sciatic nerve injury in an adult rat model. At the crush site on the sciatic nerve, the recordings of compound muscle action potential (CMAP) and the levels of several proteins related to inflammatory response were assessed at time intervals of 2, 4, and 6 weeks postsurgery. Here, we show that the recovery effect of HMW-HA treatment had significantly shortened latency and increased amplitude of CMAP compared with crushed alone, crushed plus γ-secretase inhibitor with or without HA treatment at 6 weeks after surgery. Our data reveal that HMW-HA could downregulate the expression of IL1-β, TLR4, and MMP-9, whereas these proteins expression were increased when the CD44-ICD activity was inhibited using γ-secretase inhibitor. Our findings demonstrated a novel role of CD44-ICD in HA-mediated recovery of peripheral nerve injury. Clinical relevance: an alternative for the regeneration of peripheral nerve injury.

Restorative oncodermatology: Diagnosis and management of dermatologic sequelae from cancer therapies

The long-term survival of patients with cancer has risen dramatically during the last few decades. Despite this remarkable success, the same treatments that have enabled cure or remission often secondarily affect the skin, hair, and nails. Conditions including scarring, striae distensae, persistent alopecia, pigmentary changes, nail alterations, chronic radiation dermatitis, and radiation fibrosis have been associated with anxiety, depression, decreased quality of life, and impaired function. These dermatologic changes are cosmetically disfiguring, may limit activities, and are a visual reminder of past illness. Interventions toward improving these untoward sequelae and restoring the appearance and function of skin and appendages are critical for normalization and may contribute to improved quality of life in cancer survivors. Here, we outline dermatologic sequelae of cancer therapies with a review of medical and procedural treatment strategies to restore dermatologic health in the survivorship population.

"Caught in the net": the extracellular matrix of the bone marrow in normal hematopoiesis and leukemia

The influence of the bone marrow microenvironment on normal hematopoiesis, but also leukemia, has largely been accepted. However, the focus has been predominantly on the role of various cell types or cytokines maintaining hematopoietic stem cells or protecting leukemia stem cells from different therapies. A frequently overlooked component of the bone marrow microenvironment is the extracellular matrix, which not only provides a mechanical scaffold, but also serves as a source of growth factors. We discuss here how extracellular matrix proteins directly or indirectly modulate hematopoietic stem cell physiology and influence leukemia progression. It is hoped that existing and future studies on this topic may propel forward the possibility of augmenting normal hematopoiesis and improving therapies for leukemia, for instance, by targeting of the extracellular matrix in the bone marrow.

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.

Biochemical determinants of the IGFBP-3-hyaluronan interaction

IGFBP‐3, the most abundant IGFBP and the main carrier of insulin‐like growth factor I (IGF‐I) in the circulation, can bind IGF‐1 with high affinity, which attenuates IGF/IGF‐IR interactions, thereby resulting in antiproliferative effects. The C‐terminal domain of insulin‐like growth factor‐binding protein‐3 (IGFBP‐3) is known to contain an 18‐basic amino acid motif capable of interacting with either humanin (HN) or hyaluronan (HA). We previously showed that the 18‐amino acid IGFBP‐3 peptide is capable of binding either HA or HN with comparable affinities to the full‐length IGFBP‐3 protein and that IGFBP‐3 can compete with the HA receptor, CD44, for binding HA. Blocking the interaction between HA and CD44 reduced viability of A549 human lung cancer cells. In this study, we set out to better characterize IGFBP‐3‐HA interactions. We show that both stereochemistry and amino acid identity are important determinants of the interaction between the IGFBP‐3 peptide and HA and for the peptide's ability to exert its cytotoxic effects. Binding of IGFBP‐3 to either HA or HN was unaffected by glycosylation or reduction of IGFBP‐3, suggesting that the basic 18‐amino acid residue sequence of IGFBP‐3 remains accessible for interaction with either HN or HA upon glycosylation or reduction of the full‐length protein. Removing N‐linked oligosaccharides from CD44 increased its ability to compete with IGFBP‐3 for binding HA, while reduction of CD44 rendered the protein relatively ineffective at blocking IGFBP‐3‐HA interactions. We conclude that both deglycosylation and disulfide bond formation are important for CD44 to compete with IGFBP‐3 for binding HA.

Hyaluronic Acid: Redefining Its Role

The discovery of several unexpected complex biological roles of hyaluronic acid (HA) has promoted new research impetus for biologists and, the clinical interest in several fields of medicine, such as ophthalmology, articular pathologies, cutaneous repair, skin remodeling, vascular prosthesis, adipose tissue engineering, nerve reconstruction and cancer therapy. In addition, the great potential of HA in medicine has stimulated the interest of pharmaceutical companies which, by means of new technologies can produce HA and several new derivatives in order to increase both the residence time in a variety of human tissues and the anti-inflammatory properties. Minor chemical modifications of the molecule, such as the esterification with benzyl alcohol (Hyaff-11® biomaterials), have made possible the production of water-insoluble polymers that have been manufactured in various forms: membranes, gauzes, nonwoven meshes, gels, tubes. All these biomaterials are used as wound-covering, anti-adhesive devices and as scaffolds for tissue engineering, such as epidermis, dermis, micro-vascularized skin, cartilage and bone. In this review, the essential biological functions of HA and the applications of its derivatives for pharmaceutical and tissue regeneration purposes are reviewed.

Expression of Chitotriosidase in Macrophages Modulates Atherosclerotic Plaque Formation in Hyperlipidemic Mice

Objective

To determine whether overexpression of the chitin degrading enzyme, chitotriosidase (CHIT1), modulates macrophage function and ameliorates atherosclerosis.

Approach and Results

Using a mouse model that conditionally overexpresses CHIT1 in macrophages (CHIT1-Tg) crossbred with the Ldlr ^-/- mouse provided us with a means to investigate the effects of CHIT1 overexpression in the context of atherosclerosis. In vitro, CHIT1 overexpression by murine macrophages enhanced protein expression of IL-4, IL-8, and G-CSF by BMDM upon stimulation with a combination of lipopolysaccharide (LPS) and interferon-γ (IFN-γ). Phosphorylation of ERK1/2 and Akt was also down regulated when exposed to the same inflammatory stimuli. Hyperlipidemic, Ldlr ^-/--CHIT1-Tg (CHIT1-OE) mice were fed a high-fat diet for 12 weeks in order to study CHIT1 overexpression in atherosclerosis. Although plaque size and lesion area were not affected by CHIT1 overexpression in vivo, the content of hyaluronic acid (HA) and collagen within atherosclerotic plaques of CHIT1-OE mice was significantly greater. Localization of both ECM components was markedly different between groups.

Conclusions

These data demonstrate that CHIT1 alters cytokine expression and signaling pathways of classically activated macrophages. In vivo, CHIT1 modifies ECM distribution and content in atherosclerotic plaques, both of which are important therapeutic targets.

Effects of DSPP and MMP20 Silencing on Adhesion, Metastasis, Angiogenesis, and Epithelial-Mesenchymal Transition Proteins in Oral Squamous Cell Carcinoma Cells

Recent reports highlight the potential tumorigenic role of Dentin Sialophosphoprotein (DSPP) and its cognate partner Matrix Metalloproteinase 20 (MMP-20) in Oral Squamous Cell Carcinomas (OSCCs). However, the function/mechanism of these roles is yet to be fully established. The present study aimed to investigate the effects of DSPP and MMP20 silencing on specific proteins involved in oral cancer cell adhesion, angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). Stable lines of DSPP/MMP20 silenced OSCC cell line (OSC2), previously established via lentiviral-mediated shRNA transduction, were analyzed for the effects of DSPP, MMP20, and combined DSPP–MMP20 silencing on MMP2, MMP9, integrins αvβ3 and αvβ6, VEGF, Kallikerin- 4,-5,-8,-10, E-cadherin, N-cadherin, Vimentin, met, src, snail, and Twist by Western blot. Results show a significant decrease (p < 0.05) in the expression of MMP2, MMP9, integrin αvβ3, αvβ6, VEGF, Kallikerins -4, -5, -8, -10, N-cadherin, vimentin met, src, snail and twist following DSPP and MMP20 silencing, individually and in combination. On the other hand, the expression of E-cadherin was found to be significantly increased (p < 0.05). These results suggest that the tumorigenic effect of DSPP and MMP20 on OSC2 cells is mediated via the upregulation of the genes involved in invasion, metastasis, angiogenesis, and epithelial-mesenchymal transition (EMT).

Modulating Alginate Hydrogels for Improved Biological Performance as Cellular 3D Microenvironments

The rational choice and design of biomaterials for biomedical applications is crucial for successful in vitro and in vivo strategies, ultimately dictating their performance and potential clinical applications. Alginate, a marine-derived polysaccharide obtained from seaweeds, is one of the most widely used polymers in the biomedical field, particularly to build three dimensional (3D) systems for in vitro culture and in vivo delivery of cells. Despite their biocompatibility, alginate hydrogels often require modifications to improve their biological activity, namely via inclusion of mammalian cell-interactive domains and fine-tuning of mechanical properties. These modifications enable the addition of new features for greater versatility and control over alginate-based systems, extending the plethora of applications and procedures where they can be used. Additionally, hybrid systems based on alginate combination with other components can also be explored to improve the mimicry of extracellular microenvironments and their dynamics. This review provides an overview on alginate properties and current clinical applications, along with different strategies that have been reported to improve alginate hydrogels performance as 3D matrices and 4D dynamic systems.

Regenerative Scar-Free Skin Wound Healing

IMPACT STATEMENT

Millions of people every year develop scars in response to skin injuries after surgery, trauma, or burns with significant undesired physical and psychological effects. This review provides an update on engineering strategies for scar-free wound healing and discusses the role of different cell types, growth factors, cytokines, and extracellular components in regenerative wound healing. The use of pro-regenerative matrices combined with engineered cells with less intrinsic potential for fibrogenesis is a promising strategy for achieving scar-free skin tissue regeneration.