Hyaluronidases: their genomics, structures, and mechanisms of action

Mesoporous silica–chondroitin sulphate hybrid nanoparticles for targeted and bio-responsive drug delivery

A polysaccharide based gatekeeper is attached to seal the nanopores of drug mesoporous silica nanoparticles, which facilitates uptake by cancer cells and undergoes intracellular degradation to initiate drug release.

Enzyme-sensitive magnetic core–shell nanocomposites for triggered drug release

Sodium hyaluronic acid cross-linked gel was employed to coat outside of Fe₃O₄@mSiO₂ nanopaticles to prevent drug pervasion by a novel approach.

Extracellular matrix components in the pathogenesis of type 1 diabetes

Type 1 diabetes (T1D) results from progressive immune cell-mediated destruction of pancreatic β cells. As immune cells migrate into the islets, they pass through the extracellular matrix (ECM). This ECM is composed of different macromolecules localized to different compartments within and surrounding islets; however, the involvement of this ECM in the development of human T1D is not well understood. Here, we summarize our recent findings from human and mouse studies illustrating how specific components of the islet ECM that constitute basement membranes and interstitial matrix of the islets, and surprisingly, the intracellular composition of islet β cells themselves, are significantly altered during the pathogenesis of T1D. Our focus is on the ECM molecules laminins, collagens, heparan sulfate/heparan sulfate proteoglycans, and hyaluronan, as well as on the enzymes that degrade these ECM components. We propose that islet and lymphoid tissue ECM composition and organization are critical to promoting immune cell activation, islet invasion, and destruction of islet β cells in T1D.

Hyaluronic acid oligosaccharide modified redox-responsive mesoporous silica nanoparticles for targeted drug delivery

A redox-responsive delivery system based on colloidal mesoporous silica (CMS) has been developed, in which 6-mercaptopurine (6-MP) was conjugated to vehicles by cleavable disulfide bonds. The oligosaccharide of hyaluronic acid (oHA) was modified on the surface of CMS by disulfide bonds as a targeting ligand and was able to increase the stability and biocompatibility of CMS under physiological conditions. In vitro release studies indicated that the cumulative release of 6-MP was less than 3% in the absence of glutathione (GSH), and reached nearly 80% within 2 h in the presence of 3 mM GSH. Confocal microscopy and fluorescence-activated cell sorter (FACS) methods were used to evaluate the cellular uptake performance of fluorescein isothiocyanate (FITC) labeled CMS, with and without oHA modification. The CMS-SS-oHA exhibited a higher cellular uptake performance via CD44 receptor-mediated endocytosis in HCT-116 (CD44 receptor-positive) cells than in NIH-3T3 (CD44 receptor-negative) cells. 6-MP loaded CMS-SS-oHA exhibited greater cytotoxicity against HCT-116 cells than NIH-3T3 cells due to the enhanced cell uptake behavior of CMS-SS-oHA. This study provides a novel strategy to covalently link bioactive drug and targeting ligand to the interiors and exteriors of mesoporous silica to construct a stimulus-responsive targeted drug delivery system.

Platelet hyaluronidase-2: an enzyme that translocates to the surface upon activation to function in extracellular matrix degradation

Following injury, platelets rapidly interact with the exposed extracellular matrix (ECM) of the vessel wall and the surrounding tissues. Hyaluronan (HA) is a major glycosaminoglycan component of the ECM and plays a significant role in regulating inflammation. We have recently reported that human platelets degrade HA from the surfaces of activated endothelial cells into fragments capable of inducing immune responses by monocytes. We also showed that human platelets contain the enzyme hyaluronidase-2 (HYAL2), one of two major hyaluronidases that digest HA in somatic tissues. The deposition of HA increases in inflamed tissues in several inflammatory diseases, including inflammatory bowel disease (IBD). We therefore wanted to define the mechanism by which platelets degrade HA in the inflamed tissues. In this study, we show that human platelets degrade the proinflammatory matrix HA through the activity of HYAL2 and that platelet activation causes the immediate translocation of HYAL2 from a distinct population of α-granules to platelet surfaces where it exerts its catalytic activity. Finally, we show that patients with IBD have lower platelet HYAL2 levels and activity than healthy controls.

The prophage-encoded hyaluronate lyase has broad substrate specificity and is regulated by the N-terminal domain

Streptococcus equi is the causative agent of the highly contagious disease "strangles" in equines and zoonotic meningitis in human. Spreading of infection in host tissues is thought to be facilitated by the bacterial gene encoded extracellular hyaluronate lyase (HL), which degrades hyaluronan (HA), chondroitin 6-sulfate, and dermatan sulfate of the extracellular matrix). The clinical strain S. equi 4047 however, lacks a functional extracellular HL. The prophages of S. equi and other streptococci encode intracellular HLs which are reported to partially degrade HA and do not cleave any other glycosaminoglycans. The phage HLs are thus thought to play a role limited to the penetration of streptococcal HA capsules, facilitating bacterial lysogenization and not in the bacterial pathogenesis. Here we systematically looked into the structure-function relationship of S. equi 4047 phage HL. Although HA is the preferred substrate, this HL has weak activity toward chondroitin 6-sulfate and dermatan sulfate and can completely degrade all of them. Even though the catalytic triple-stranded β-helix domain of phage HL is functionally independent, its catalytic efficiency and specificity is influenced by the N-terminal domain. The phage HL also interacts with human transmembrane glycoprotein CD44. The above results suggest that the streptococci can use phage HLs to degrade glycosaminoglycans of the extracellular matrix for spreading virulence factors and toxins while utilizing the disaccharides as a nutrient source for proliferation at the site of infection.

FRET based ratio-metric sensing of hyaluronidase in synthetic urine as a biomarker for bladder and prostate cancer

Elevated hyaluronidase levels are found in the urine of bladder and prostate cancer patients. Therefore, HA-ase is regarded as an important biomarker for the detection of these cancers. In this report, we use a FRET based ratiometric sensing approach to detect the level of HA-ase in synthetic urine. For this, we have used a HA-FRET probe (hyaluronan) labeled with fluorescein as a donor and rhodamine as an acceptor. We monitor the digestion of our HA-FRET probe with different concentrations of HA-ase in synthetic urine via fluorescence emission. The extent to which FRET is released depends on the concentration of HA-ase. Our fluorescence intensity results are also supported with time resolved fluorescence decay data. This assay can be used to develop a non-invasive technique for the detection of bladder and/or prostate cancer progression.

Draft Genome Sequence of a Deep-Sea Bacterium, Bacillus niacini Strain JAM F8, Involved in the Degradation of Glycosaminoglycans

Here, we report the draft genome sequence of Bacillus niacini JAM F8, which was newly isolated from deep-sea sediment at a depth of 2,759 m from the Izu-Ogasawara Trench. An array of genes related to degradation of glycosaminoglycans in this bacterium was identified by whole-genome analysis.

Prolonged exposure to hyaluronidase decreases the fertilization and development rates of fresh and cryopreserved mouse oocytes

Hyaluronidase is generally used to remove cumulus cells from mouse oocytes before oocyte cryopreservation, intracytoplasmic sperm injection or DNA injection. In general, use of cumulus-free mouse oocytes decreases in vitro fertilizing ability compared with cumulus-surrounded oocytes. The effect of hyaluronidase exposure on the quality of mouse oocytes is not fully understood. Here, we investigated the effect of hyaluronidase exposure time on the fertilization rate of fresh and vitrified mouse oocytes and their subsequent developmental ability in vitro. We found that the fertilization rate decreased with hyaluronidase treatments. This reduction in the fertilization rate following treatment with hyaluronidase was fully reversed by removal of the zona pellucida. In addition, oocytes treated with hyaluronidase for 5 min or longer had a reduced capacity to develop to the morula and blastocyst stage. The survival, fertilization, and developmental rates of vitrified-warmed oocytes were also reduced by longer exposure to hyaluronidase. In conclusion, these results suggest that prolonged exposure to hyaluronidase decreases the quality of mouse oocytes and shorter hyaluronidase treatment times may help achieve a stable and high fertilization rate in fresh and cryopreserved oocytes.

Upconverting nanoparticles with a mesoporous TiO₂ shell for near-infrared-triggered drug delivery and synergistic targeted cancer therapy

Malignant tumors remain a major health burden throughout the world and effective therapeutic strategies are urgently needed. Herein, we report the synthesis of upconverting nanoparticles with a mesoporous TiO2 (mTiO2) shell for near-infrared (NIR)-triggered drug delivery and synergistic targeted cancer therapy. The NaGdF4:Yb,Tm could convert NIR light to UV light, which activated the mTiO2 to produce reactive oxygen species for photodynamic therapy (PDT). Due to the large surface area and porous structure, the mTiO2 shell endowed the nanoplatform with another functionality of anticancer drug loading for chemotherapy. The hyaluronic acid modified on the surface not only promised controlled drug release but also conferred targeted ability of the system toward cluster determinant 44 overexpressed cancer cells. More importantly, cytotoxicity experiments demonstrated that combined therapy mediated the highest rate of death of breast carcinoma cells compared with that of single chemotherapy or PDT.

Cloning and expression of the enzymatic region of Streptococcal hyaluronidase

OBJECTIVES

Streptococcus pyogenes produces extracellular hyaluronidase enzyme. This enzyme is directly associated with the spread of the organism during infection. The objective of the present study was to clone and express the nucleotide sequence of the enzyme which is involved in hyaluronidase enzymatic activity.

MATERIALS AND METHODS

The enzymatic region of hyaluronidase gene was detected by bioinformatics method. The PCR method was used to amplify enzymatic region of hyaluronidase gene from chromosomal DNA of Streptococcus pyogenes. The eluted product was cloned into the prokaryotic expression vector pET32a which was digested by BamHI and HindIII restriction endonuclease enzymes. The target protein was expressed in the Escherichia coli. The bacteria including pET32a-hylA (hylA is abbreviation of Streptococcus pyogenes hyaluronidase gene and hylA is abbreviation of Streptococcus pyogenes hyaluronidase protein) plasmids were induced by IPTG and analyzed by SDS-PAGE. The enzymatic evaluation and antigenicity was finally studied.

RESULTS

Enzymes digestion analysis, sequencing results showed that the target gene (1296 base pair) was inserted correctly into the recombinant vector. The expressed protein (65 KDa) was purified successfully via affinity chromatography. Data also indicated that enzymatic region of hyaluronidase protein from Streptococcus pyogenes was recognized in all 5 patient's sera.

CONCLUSION

In general, it is possible to produce the enzymatic regions of the Streptococcus pyogenes hyaluronidase in E. coli. The antigenic property of the produced protein is well retained. Considering the product's domestic demand and also low efficiency of production and pathogenicity of Streptococcus species, it is possible to produce it as recombinant product.

Hyaluronan: towards novel anti-cancer therapeutics

The understanding of the role of hyaluronan in physiology and various pathological conditions has changed since the complex nature of its synthesis, degradation and interactions with diverse binding proteins was revealed. Initially perceived only as an inert component of connective tissue, it is now known to be involved in multiple signaling pathways, including those involved in cancer pathogenesis and progression. Hyaluronan presents a mixture of various length polymer molecules from finely fragmented oligosaccharides, polymers intermediate in size, to huge aggregates of high molecular weight hyaluronan. While large molecules promote tissue integrity and quiescence, the generation of breakdown products enhances signaling transduction, contributing to the pro-oncogenic behavior of cancer cells. Low molecular weight hyaluronan has well-established angiogenic properties, while the smallest hyaluronan oligomers may counteract tumor development. These equivocal properties make the role of hyaluronan in cancer biology very complex. This review surveys recent data on hyaluronan biosynthesis, metabolism, and interactions with its binding proteins called hyaladherins (CD44, RHAMM), providing themolecular background underlying its differentiated biological activity. In particular, the article critically presents current ideas on actual role of hyaluronan in cancer. The paper additionally maps a path towards promising novel anti-cancer therapeutics which target hyaluronan metabolic enzymes and hyaladherins, and constitute hyaluronan-based drug delivery systems.

A novel eliminase from a marine bacterium that degrades hyaluronan and chondroitin sulfate

Lyases cleave glycosaminoglycans (GAGs) in an eliminative mechanism and are important tools for the structural analysis and oligosaccharide preparation of GAGs. Various GAG lyases have been identified from terrestrial but not marine organisms even though marine animals are rich in GAGs with unique structures and functions. Herein we isolated a novel GAG lyase for the first time from the marine bacterium Vibrio sp. FC509 and then recombinantly expressed and characterized it. It showed strong lyase activity toward hyaluronan (HA) and chondroitin sulfate (CS) and was designated as HA and CS lyase (HCLase). It exhibited the highest activities to both substrates at pH 8.0 and 0.5 m NaCl at 30 °C. Its activity toward HA was less sensitive to pH than its CS lyase activity. As with most other marine enzymes, HCLase is a halophilic enzyme and very stable at temperatures from 0 to 40 °C for up to 24 h, but its activity is independent of divalent metal ions. The specific activity of HCLase against HA and CS reached a markedly high level of hundreds of thousands units/mg of protein under optimum conditions. The HCLase-resistant tetrasaccharide Δ(4,5)HexUAα1-3GalNAc(6-O-sulfate)β1-4GlcUA(2-O-sulfate)β1-3GalNAc(6-O-sulfate) was isolated from CS-D, the structure of which indicated that HCLase could not cleave the galactosaminidic linkage bound to 2-O-sulfated d-glucuronic acid (GlcUA) in CS chains. Site-directed mutagenesis indicated that HCLase may work via a catalytic mechanism in which Tyr-His acts as the Brønsted base and acid. Thus, the identification of HCLase provides a useful tool for HA- and CS-related research and applications.

Enzymatic properties and primary structures of hyaluronidases from two species of lionfish (Pterois antennata and Pterois volitans)

Lionfish are representative venomous fish, having venomous glandular tissues in dorsal, pelvic and anal spines. Some properties and primary structures of proteinaceous toxins from the venoms of three species of lionfish, Pterois antennata, Pterois lunulata and Pterois volitans, have so far been clarified. Our recent survey established the presence of hyaluronidase, presumably a toxin-spreading factor, in the venoms of P. antennata and P. volitans. This prompted us to examine enzymatic properties and primary structures of lionfish hyaluronidases. The hyaluronidases of P. antennata and P. volitans were shown to be optimally active at pH 6.6, 37°C and 0.1 M NaCl and specifically active against hyaluronan. These enzymatic properties are almost the same as those of stonefish hyaluronidases. The primary structures (483 amino acid residues) of the lionfish hyaluronidases were elucidated by a cDNA cloning strategy using degenerate primers designed from the reported amino acid sequences of the stonefish hyaluronidases. Both lionfish hyaluronidases share as high as 99.6% of sequence identity with each other and also considerably high identities (72-77%) with the stonefish hyaluronidases but rather low identities (25-40%) with other hyaluronidases from mammals and venomous animals. In consistent with this, phylogenetic tree analysis revealed that the lionfish hyaluronidases, together with the stonefish hyaluronidases, form a cluster independently of other hyaluronidases. Nevertheless, the lionfish hyaluronidases as well as the stonefish hyaluronidases almost maintain structural features (active site, glyco_hydro_56 domain and cysteine location) observed in other hyaluronidases.

A nanoparticle formula for delivering siRNA or miRNAs to tumor cells in cell culture and in vivo

To improve RNA delivery, we present a protocol to produce an RNA carrier based on a Zn(II)-dipicolylamine (Zn-DPA) analog, which is an artificial receptor for phosphate anion derivatives. We further functionalized this Zn-DPA analog to hyaluronic acid (HA)-based self-assembled nanoparticles (HA-NPs) with a hydrodynamic diameter of 100 nm by conjugating amine-functionalized Zn-DPA molecules onto the HA-NPs through amide formation, resulting in efficient tumor-targeted delivery of RNAs (siRNAs, miRNA or other short oligoribonucleotides) and small-molecule drugs. The functional group of Zn-DPA can be converted into other groups such as a carboxylic or thiol group, and the DPA analog can be covalently attached to a variety of existing and novel platforms or formulations for the development of multifunctional materials via standard bioconjugation techniques. Protocols for RNA formulation and delivery into tumor tissues and tumor cells are also described. Our design strategy offers a versatile and practical method for delivering both RNA and chemotherapeutics to tumor cells and expands existing nanomaterial capabilities to further the field of drug and gene delivery.

Collagen VI and hyaluronan: the common role in breast cancer

Collagen VI and hyaluronan are widely distributed extracellular matrix macromolecules that play a crucial role in tissue development and are highly expressed in cancers. Both hyaluronan and collagen VI are upregulated in breast cancer, generating a microenvironment that promotes tumour progression and metastasis. A growing number of studies show that these two molecules are involved in inflammation and angiogenesis by recruiting macrophages and endothelial cells, respectively. Additionally, collagen VI induces epithelial-mesenchymal transition that is correlated to increased synthesis of hyaluronan in mammary cells. Hyaluronan has also a specific role in cellular functions that depends mainly on the size of the polymer, whereas the effect of collagen VI in tumour progression may be the result of the intact molecule or the C5 peptide of α3(VI) chain, known as endotrophin. Collectively, these findings strongly support the parallel role of these molecules in tumour progression and suggest that they may be used as prognostic factors for the breast cancer treatment.

In vitro techniques to assess the proficiency of skin care cosmetic formulations

Cosmetics comprising either natural or synthetic components are used almost regularly and universally in different forms to enhance the beauty. The utmost disclosure of human membrane to sunlight and environmental pollution results in the exhibition of free radical, that react with deoxyribonucleic acid, proteins and fatty acids, causation oxidative destruction dysfunction of the antioxidant system. In skin, the formation of reactive oxygen species leads to skin diseases, predominantly cutaneous malignancies, immunosuppression, wrinkles, aging, etc., The human organism fosters a barrier practice against the destructive action of free radicals, comprising mostly of vitamins, carotenoids and enzymes. Cosmetic products are the best option to reduce skin disorders such as hyper pigmentation, skin aging, skin wrinkling and rough skin texture, etc., Hence in this review, we conferred various in vitro methods that are used for the development of novel cosmetic formulation. There is an expanding fascinate employing in vitro techniques because they are less time consuming, more cost-effective and lessen the participation of human volunteers.

Versatile RNA interference nanoplatform for systemic delivery of RNAs

Development of nontoxic, tumor-targetable, and potent in vivo RNA delivery systems remains an arduous challenge for clinical application of RNAi therapeutics. Herein, we report a versatile RNAi nanoplatform based on tumor-targeted and pH-responsive nanoformulas (NFs). The NF was engineered by combination of an artificial RNA receptor, Zn(II)-DPA, with a tumor-targetable and drug-loadable hyaluronic acid nanoparticle, which was further modified with a calcium phosphate (CaP) coating by in situ mineralization. The NF can encapsulate small-molecule drugs within its hydrophobic inner core and strongly secure various RNA molecules (siRNAs, miRNAs, and oligonucleotides) by utilizing Zn(II)-DPA and a robust CaP coating. We substantiated the versatility of the RNAi nanoplatform by demonstrating effective delivery of siRNA and miRNA for gene silencing or miRNA replacement into different human types of cancer cells in vitro and into tumor-bearing mice in vivo by intravenous administration. The therapeutic potential of NFs coloaded with an anticancer drug doxorubicin (Dox) and multidrug resistance 1 gene target siRNA (siMDR) was also demonstrated in this study. NFs loaded with Dox and siMDR could successfully sensitize drug-resistant OVCAR8/ADR cells to Dox and suppress OVCAR8/ADR tumor cell proliferation in vitro and tumor growth in vivo. This gene/drug delivery system appears to be a highly effective nonviral method to deliver chemo- and RNAi therapeutics into host cells.

Matrix hyaluronan-activated CD44 signaling promotes keratinocyte activities and improves abnormal epidermal functions

Hyaluronan (HA), a major component of the extracellular matrix, is enriched in skin tissues, particularly the epidermis. HA binds to a ubiquitous, abundant, and functionally important family of cell surface receptors, CD44. This article reviews the current evidence for HA/CD44-mediated activation of RhoGTPase signaling and calcium mobilization, leading to the regulation of keratinocyte activities and various epidermal functions. It further discusses the role of HA-mediated CD44 interactions with unique downstream effectors, such as RhoGTPases (RhoA and Rac1), Rho-kinase, protein kinase-Nγ, and phosphoinositide-specific phospholipases (phospholipases Cε and Cγ1) in coordinating certain intracellular signaling pathways, such as calcium mobilization, phosphatidylinositol 3-kinase-AKT activation, cortactin-actin binding, and actin-associated cytoskeleton reorganization; generating the onset of important keratinocyte activities, such as cell adhesion, proliferation, migration, and differentiation; and performing epidermal functions. Topical application of selective HA fragments (large versus small HA) to the skin of wild-type mice (but not CD44 knockout mice) improves keratinocyte-associated epidermal functions and accelerates permeability barrier recovery and skin wound healing. Consequently, specific HA fragment (large versus small HA)-mediated signaling events (through the CD44 receptor) are required for keratinocyte activities, which offer new HA-based therapeutic options for patients experiencing epidermal dysfunction and skin damage as well as aging-related skin diseases, such as epidermal thinning (atrophy), permeability barrier dysfunction, and chronic nonhealing wounds.

Tissue integrity signals communicated by high-molecular weight hyaluronan and the resolution of inflammation

The extracellular matrix polysaccharide hyaluronan (HA) exerts size-dependent effects on leukocyte behavior. Low-molecular weight HA is abundant at sites of active tissue catabolism and promotes inflammation via effects on Toll-like receptor signaling. Conversely, high-molecular weight HA is prevalent in uninjured tissues and is anti-inflammatory. We propose that the ability of high-molecular weight but not low-molecular weight HA to cross-link CD44 functions as a novel form of pattern recognition that recognizes intact tissues and communicates "tissue integrity signals" that promote resolution of local immune responses.

High-yield novel leech hyaluronidase to expedite the preparation of specific hyaluronan oligomers

Hyaluronidases (HAases), particularly leech HAases, have attracted intense attention due to their broad applications in medical treatments and great potential for the enzymatic production of hyaluronan oligosaccharides. However, little is known about this third interesting family of HAases. Here, we applied the random amplification of cDNA ends polymerase chain reaction (RACE-PCR) approach to identify the first leech HAase-encoding gene. By combining protein engineering and high-density culture, we achieved high-level production (8.42 × 10⁵ U ml⁻¹) in the yeast Pichia pastoris secretory expression system. Compared with the commercial bovine testicular HAase, the recombinant leech HAase exhibited superior enzymatic properties. Furthermore, analysis of the hydrolytic process suggested that this novel enzyme adopts a nonprocessive endolytic mode, yielding a narrow-spectrum of specific HA oligosaccharides with different incubation times. Large-scale production of this novel leech HAase will not only greatly promote medical applications but also facilitate the enzymatic production of specific HA oligosaccharides.

Expression of a functional recombinant oleosin-human hyaluronidase hPH-20 fusion in Arabidopsis thaliana

The use of plants as expression systems for the production of recombinant proteins has distinct advantages, such as safety, ease, low cost and high yields. A plant binary expression vector, pOTBar-hPH20, containing an oleosin-hPH20 fusion gene and a Basta selection marker gene was constructed and introduced into Arabidopsis thaliana via the floral dip method. Transformed A. thaliana seed lines were obtained and analyzed by PCR. The PCR results indicated that oleosin-hPH20 fusion gene was integrated into the A. thaliana genome. The oleosin-hPH20 fusion protein was detected by SDS-PAGE and Western blot analysis. The oleosin-hPH20 fusion protein was expressed and had good antigenicity in the transgenic A. thaliana seeds. An enzyme assay suggested that the recombinant oleosin-hPH20 fusion protein had hyaluronidase activity.

Subcellular trafficking and activity of Hyal-1 and its processed forms in murine macrophages

The hyaluronidase Hyal-1 is an acid hydrolase that degrades hyaluronic acid (HA), a component of the extracellular matrix. It is often designated as a lysosomal protein. Yet few data are available on its intracellular localization and trafficking. We demonstrate here that in RAW264.7 murine macrophages, Hyal-1 is synthesized as a glycosylated precursor that is only weakly mannose 6-phosphorylated. Nevertheless, this precursor traffics to endosomes, via a mannose 6-phosphate-independent secretion/recapture mechanism that involves the mannose receptor. Once in endosomes, it is processed into a lower molecular mass form that is transported to lysosomes, where its activity could be detected using native gel zymography. Indeed, this activity co-distributed with lysosomal hydrolases in the densest fraction of a self-forming Percoll(TM) density gradient. Moreover, it shifted toward the lower density region, in parallel with those hydrolases, when a decrease of lysosomal density was induced by the endocytosis of sucrose. Interestingly, the activity of the processed form of Hyal-1 was largely underestimated when assayed by zymography after SDS-PAGE and subsequent renaturation of the proteins, by contrast to the full-length protein that could efficiently degrade HA in those conditions. These results suggest that noncovalent associations support the lysosomal activity of Hyal-1.

Hyaluronan, a crucial regulator of inflammation

Hyaluronan (HA), a major component of the extracellular matrix (ECM), plays a key role in regulating inflammation. Inflammation is associated with accumulation and turnover of HA polymers by multiple cell types. Increasingly through the years, HA has become recognized as an active participant in inflammatory, angiogenic, fibrotic, and cancer promoting processes. HA and its binding proteins regulate the expression of inflammatory genes, the recruitment of inflammatory cells, the release of inflammatory cytokines, and can attenuate the course of inflammation, providing protection against tissue damage. A growing body of evidence suggests the cell responses are HA molecular weight dependent. HA fragments generated by multiple mechanisms throughout the course of inflammatory pathologies, elicit cellular responses distinct from intact HA. This review focuses on the role of HA in the promotion and resolution of inflammation.

ATP-triggered anticancer drug delivery

Stimuli-triggered drug delivery systems have been increasingly used to promote physiological specificity and on-demand therapeutic efficacy of anticancer drugs. Here we utilize adenosine-5'-triphosphate (ATP) as a trigger for the controlled release of anticancer drugs. We demonstrate that polymeric nanocarriers functionalized with an ATP-binding aptamer-incorporated DNA motif can selectively release the intercalating doxorubicin via a conformational switch when in an ATP-rich environment. The half-maximal inhibitory concentration of ATP-responsive nanovehicles is 0.24 μM in MDA-MB-231 cells, a 3.6-fold increase in the cytotoxicity compared with that of non-ATP-responsive nanovehicles. Equipped with an outer shell crosslinked by hyaluronic acid, a specific tumour-targeting ligand, the ATP-responsive nanocarriers present an improvement in the chemotherapeutic inhibition of tumour growth using xenograft MDA-MB-231 tumour-bearing mice. This ATP-triggered drug release system provides a more sophisticated drug delivery system, which can differentiate ATP levels to facilitate the selective release of drugs.

Knock-down of CD44 regulates endothelial cell differentiation via NFκB-mediated chemokine production

A striking feature of microvascular endothelial cells is their capacity to fuse and differentiate into tubular structures when grown in three-dimensional (3D) extracellular matrices, in collagen or Matrigel, mimicking the in vivo blood vessel formation. In this study we demonstrate that human telomerase-immortalised foreskin microvascular endothelial (TIME) cells express high levels of the hyaluronan receptor CD44 and the hyaluronidase HYAL2. Knock-down of CD44 or HYAL2 resulted in an inability of TIME cells to form a tubular network, suggesting a key regulatory role of hyaluronan in controlling TIME cell tubulogenesis in 3D matrices. Knock-down of CD44 resulted in an upregulation of mRNA expression of the chemokines CXCL9 and CXCL12, as well as their receptors CXCR3 and CXCR4. This was accompanied by a defect maturation of the tubular structure network and increased phosphorylation of the inhibitor of NFκB kinase (IKK) complex and thus translocation of NFκB into the nucleus and activation of chemokine targed genes. Furthermore, the interaction between CD44 and hyaluronan determines the adhesion of breast cancer cells. In summary, our observations support the notion that the interaction between CD44 and hyaluronan regulates microvascular endothelial cell tubulogenesis by affecting the expression of cytokines and their receptors, as well as breast cancer dissemination.

Hyaluronan-CD44 interaction promotes c-Jun signaling and miRNA21 expression leading to Bcl-2 expression and chemoresistance in breast cancer cells

MicroRNA-21 (miR-21) is associated with the development of solid tumors progression including breast cancer. In this study we investigated matrix hyaluronan (HA)-CD44 (a primary HA receptor) interaction with c-Jun N-Terminal Kinase (JNK)/c-Jun signaling in MDA-MB-468 breast cancer cells [a triple-negative (estrogen receptor-negative/progesterone receptor-negative/HER2-negative) breast cancer cell line]. Our results indicated that HA binding to CD44 promotes c-Jun nuclear translocation and transcriptional activation. Further analyses revealed that miR-21 is regulated by an upstream promoter containing AP1 binding site(s), and chromatin immunoprecipitation (CHIP) assays demonstrated that stimulation of miR-21 expression by HA/CD44 interaction is c-Jun-dependent in these breast cancer cells. This process results in an increase of the anti-apoptosis protein Bcl-2 and upregulation of inhibitors of the apoptosis family of proteins (IAPs) as well as chemoresistance in MDA-MB-468 cells. Treatment with c-Jun specific small interfering RNAs effectively blocks HA-mediated c-Jun signaling and abrogates miR-21 production as well as causes downregulation of survival proteins (Bcl-2 and IAPs) and enhancement of chemosensitivity. In addition, our results demonstrated that anti-miR-21 inhibitor not only downregulates Bcl-2/IAP expression but also increases chemosensitivity in HA-treated breast cancer cells. Together, these findings suggest that the HA/CD44-induced c-Jun signaling plays a pivotal role in miR-21 production leading to survival protein (Bcl-2/IAP) upregulation and chemoresistance in triple negative breast cancer cells such as MDA-MB-468 cell line. This novel HA/CD44-mediated c-Jun signaling pathway and miR-21 production provide a new drug target for the future intervention strategies to treat breast cancer.

How to kill the honey bee larva: genomic potential and virulence mechanisms of Paenibacillus larvae

Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity.

Comparative analysis of salivary gland transcriptomes of Phlebotomus orientalis sand flies from endemic and non-endemic foci of visceral leishmaniasis

Background

In East Africa, Phlebotomus orientalis serves as the main vector of Leishmania donovani, the causative agent of visceral leishmaniasis (VL). Phlebotomus orientalis is present at two distant localities in Ethiopia; Addis Zemen where VL is endemic and Melka Werer where transmission of VL does not occur. To find out whether the difference in epidemiology of VL is due to distant compositions of P. orientalis saliva we established colonies from Addis Zemen and Melka Werer, analyzed and compared the transcriptomes, proteomes and enzymatic activity of the salivary glands.

Methodology/Principal Findings

Two cDNA libraries were constructed from the female salivary glands of P. orientalis from Addis Zemen and Melka Werer. Clones of each P. orientalis library were randomly selected, sequenced and analyzed. In P. orientalis transcriptomes, we identified members of 13 main protein families. Phylogenetic analysis and multiple sequence alignments were performed to evaluate differences between the P. orientalis colonies and to show the relationship with other sand fly species from the subgenus Larroussius. To further compare both colonies, we investigated the humoral antigenicity and cross-reactivity of the salivary proteins and the activity of salivary apyrase and hyaluronidase.

Conclusions

This is the first report of the salivary components of P. orientalis, an important vector sand fly. Our study expanded the knowledge of salivary gland compounds of sand fly species in the subgenus Larroussius. Based on the phylogenetic analysis, we showed that P. orientalis is closely related to Phlebotomus tobbi and Phlebotomus perniciosus, whereas Phlebotomus ariasi is evolutionarily more distinct species. We also demonstrated that there is no significant difference between the transcriptomes, proteomes or enzymatic properties of the salivary components of Addis Zemen (endemic area) and Melka Werer (non-endemic area) P. orientalis colonies. Thus, the different epidemiology of VL in these Ethiopian foci cannot be attributed to the salivary gland composition.

Phlebotomus orientalis is the vector of visceral leishmaniasis (VL) caused by Leishmania donovani in Northeast Africa. Immunization with sand fly saliva or with individual salivary proteins has been shown to protect against leishmaniasis in different hosts, warranting the intensive study of salivary proteins of sand fly vectors. In our study, we characterize the salivary compounds of P. orientalis, thereby broadening the repertoire of salivary proteins of sand fly species belonging to the subgenus Larroussius. In order to find out whether there is any connection between the composition of P. orientalis saliva and the epidemiology of VL in two distinct Ethiopian foci, Addis Zemen and Melka Werer, we studied the transcriptomes, proteomes, enzymatic activities, and the main salivary antigens in two P. orientalis colonies originating from these areas. We did not detect any significant difference between the saliva of female sand flies originating in Addis Zemen (endemic area) and Melka Werer (non-endemic area). Therefore, the different epidemiology of VL in these Ethiopian foci cannot be related to the distant salivary gland protein composition. Identifying the sand fly salivary gland compounds will be useful for future research focused on characterizing suitable salivary proteins as potential anti-Leishmania vaccine candidates.

Molecular, immunological, and biological characterization of Tityus serrulatus venom hyaluronidase: new insights into its role in envenomation

Background

Scorpionism is a public health problem in Brazil, and Tityus serrulatus (Ts) is primarily responsible for severe accidents. The main toxic components of Ts venom are low-molecular-weight neurotoxins; however, the venom also contains poorly characterized high-molecular-weight enzymes. Hyaluronidase is one such enzyme that has been poorly characterized.

Methods and principal findings

We examined clones from a cDNA library of the Ts venom gland and described two novel isoforms of hyaluronidase, TsHyal-1 and TsHyal-2. The isoforms are 83% identical, and alignment of their predicted amino acid sequences with other hyaluronidases showed conserved residues between evolutionarily distant organisms. We performed gel filtration followed by reversed-phase chromatography to purify native hyaluronidase from Ts venom. Purified native Ts hyaluronidase was used to produce anti-hyaluronidase serum in rabbits. As little as 0.94 µl of anti-hyaluronidase serum neutralized 1 LD₅₀ (13.2 µg) of Ts venom hyaluronidase activity in vitro. In vivo neutralization assays showed that 121.6 µl of anti-hyaluronidase serum inhibited mouse death 100%, whereas 60.8 µl and 15.2 µl of serum delayed mouse death. Inhibition of death was also achieved by using the hyaluronidase pharmacological inhibitor aristolochic acid. Addition of native Ts hyaluronidase (0.418 µg) to pre-neutralized Ts venom (13.2 µg venom+0.94 µl anti-hyaluronidase serum) reversed mouse survival. We used the SPOT method to map TsHyal-1 and TsHyal-2 epitopes. More peptides were recognized by anti-hyaluronidase serum in TsHyal-1 than in TsHyal-2. Epitopes common to both isoforms included active site residues.

Conclusions

Hyaluronidase inhibition and immunoneutralization reduced the toxic effects of Ts venom. Our results have implications in scorpionism therapy and challenge the notion that only neurotoxins are important to the envenoming process.

In Brazil, accidents with scorpion stings have been a serious public health problem, and Tityus serrulatus (Ts) is primarily responsible for severe accidents. Therefore, efforts have been made to understand the characteristics of the molecules present in scorpion venoms. These venoms are complex mixtures, in which neurotoxins are the main toxic components. Ts venom also contains enzymes, such as hyaluronidase, that have not been well characterized. In this study, we described for the first time two sequences of Ts hyaluronidase isoforms: TsHyal-1 and TsHyal-2. We purified native hyaluronidase from Ts venom and produced anti-hyaluronidase serum in rabbits. This serum neutralized hyaluronidase activity present in Ts venom. In vivo neutralization assays showed that anti-hyaluronidase serum inhibited and delayed mouse death after injection of a lethal dose (50% lethal dose, LD₅₀) of Ts venom. This work confirms the influence of hyaluronidase in Ts venom lethality and paves the way for the development of new strategies for scorpionism therapy.

Excellent postoperative analgesia with the addition of hyaluronidase to lignocaine for subcostal TAP block used in conjunction with systemic analgesia for laparoscopic cholecystectomy

Subcostal transversus abdominis plane (TAP) blocks provide good postoperative analgesia for laparoscopic cholecystectomies. We hypothesised that adding hyaluronidase may improve the efficacy of this technique by increasing spread of the local anaesthetic (LA). In this case, we performed a bilateral ultrasound-guided subcostal TAP block using lignocaine (40 mL 1%) with hyaluronidase (75 IU/mL) for postoperative analgesia following elective laparoscopic cholecystectomy. It was used in combination with intraoperative morphine, diclofenac and paracetamol. Regular paracetamol was administered postoperatively. We monitored serial serum lignocaine levels and recorded the patient's visual analogue scale (VAS) pain scores postoperatively. We found that the patient experienced excellent analgesia throughout the postoperative period and that the serum lignocaine levels did not exceed the therapeutic range.

Enhanced cognitive flexibility in reversal learning induced by removal of the extracellular matrix in auditory cortex

During brain maturation, the occurrence of the extracellular matrix (ECM) terminates juvenile plasticity by mediating structural stability. Interestingly, enzymatic removal of the ECM restores juvenile forms of plasticity, as for instance demonstrated by topographical reconnectivity in sensory pathways. However, to which degree the mature ECM is a compromise between stability and flexibility in the adult brain impacting synaptic plasticity as a fundamental basis for learning, lifelong memory formation, and higher cognitive functions is largely unknown. In this study, we removed the ECM in the auditory cortex of adult Mongolian gerbils during specific phases of cortex-dependent auditory relearning, which was induced by the contingency reversal of a frequency-modulated tone discrimination, a task requiring high behavioral flexibility. We found that ECM removal promoted a significant increase in relearning performance, without erasing already established-that is, learned-capacities when continuing discrimination training. The cognitive flexibility required for reversal learning of previously acquired behavioral habits, commonly understood to mainly rely on frontostriatal circuits, was enhanced by promoting synaptic plasticity via ECM removal within the sensory cortex. Our findings further suggest experimental modulation of the cortical ECM as a tool to open short-term windows of enhanced activity-dependent reorganization allowing for guided neuroplasticity.

HAS2 and CD44 in breast tumorigenesis

Metastatic spread of breast cancer cells, facilitated by the epithelial-mesenchymal transition (EMT) process, is responsible for the majority of breast cancer mortality. Increased levels of hyaluronan due to deregulation of hyaluronan-synthesizing enzymes, like HAS2, and expression of CD44, the key receptor for hyaluronan, are correlated to poor outcome of patients with basal-like breast cancer. TGFβ induces HAS2 and CD44, both of which are required in the course of efficient TGFβ-induced EMT processes by mammary epithelial cells. Elucidation of the molecular mechanisms underlying tumor-stroma interactions in breast cancer including the regulation of HAS2 and CD44 expression may contribute to the development of better strategies to treat breast cancer patients.

Intramuscular DNA vaccination protocols mediated by electric fields

Vaccination is historically one of the most important methods for preventing infectious diseases in humans and animals. New insights in the biology of the immune system allow a more rational design of vaccines, and new vaccination strategies are emerging. DNA vaccines have been proposed as a promising approach for introducing foreign antigens into the host for inducing protective immunity against infectious and cancer diseases. Nevertheless, because of their poor immunogenicity, plasmid DNA vaccination strategies need further implementations. Recent data suggest electrotransfer as a useful tool to improve DNA-based vaccination protocols, being able to stimulate both the humoral and cellular immune responses. In preclinical trials, gene electrotransfer is successfully used in prime-boost combination protocols and its tolerability and safety has been demonstrated also in Phase I clinical trials. In this chapter, we report a short comment supporting electrotransfer as an effective strategy to improve DNA-based vaccination protocols and describe the vaccination procedures by plasmid DNA in combination with electrotransfer and hyaluronidase pretreatment in use in our laboratory.

Hyaluronic Acid: from biochemical characteristics to its clinical translation in assessment of liver fibrosis

CONTEXT

Hyaluronic acid (HA) is a high molecular weight polysaccharide that is distributed in all bodily tissues and fluids. The liver is the most important organ involved in the synthesis and degradation of HA. Research has shown that liver cell injury can affect serum HA levels. In this review, authors aimed to describe the biochemical and physiological roles of this glycosaminoglycan and its changes in various liver diseases.

EVIDENCE ACQUISITION

Liver fibrosis and in more severe form, cirrhosis are results of an imbalance between fibrogenesis and fibrinolysis. Liver biopsy is the gold standard to assess liver necro inflammatory injuries. This method is invasive and has some major side effects; therefore it is an unfavorable method for both physicians and patients. Now, a wide variety of noninvasive methods have been introduced based on evaluating serum level of different markers. They are safe, readily available, and more favorable. Serum HA levels are used by some researchers to assess stages of liver fibrosis.

RESULTS

There are several scientific studies indicating HA as a biomarker for high score fibrosis and cirrhosis in various liver diseases alone or in algorithm models. It seems from various algorithm models that the use of HA as a major constituent has more diagnostic reliability and accuracy than the use of HA alone.

CONCLUSIONS

Use of HA in an algorithm model, is an extra and valuable tool for assessing liver necro inflammatory injuries- in parallel with liver biopsy- but more comprehensive studies are needed to approve the use of HA as an appropriate clinical tool.

A polysaccharide lyase from Stenotrophomonas maltophilia with a unique, pH-regulated substrate specificity

Polysaccharide lyases (PLs) catalyze the depolymerization of anionic polysaccharides via a β-elimination mechanism. PLs also play important roles in microbial pathogenesis, participating in bacterial invasion and toxin spread into the host tissue via degradation of the host extracellular matrix, or in microbial biofilm formation often associated with enhanced drug resistance. Stenotrophomonas maltophilia is a Gram-negative bacterium that is among the emerging multidrug-resistant organisms associated with chronic lung infections as well as with cystic fibrosis patients. A putative alginate lyase (Smlt1473) from S. maltophilia was heterologously expressed in Escherichia coli, purified in a one-step fashion via affinity chromatography, and activity as well as specificity determined for a range of polysaccharides. Interestingly, Smlt1473 catalyzed the degradation of not only alginate, but poly-β-D-glucuronic acid and hyaluronic acid as well. Furthermore, the pH optimum for enzymatic activity is substrate-dependent, with optimal hyaluronic acid degradation at pH 5, poly-β-D-glucuronic acid degradation at pH 7, and alginate degradation at pH 9. Analysis of the degradation products revealed that each substrate was cleaved endolytically into oligomers comprised predominantly of even numbers of sugar groups, with lower accumulation of trimers and pentamers. Collectively, these results imply that Smlt1473 is a multifunctional PL that exhibits broad substrate specificity, but utilizes pH as a mechanism to achieve selectivity.

Deregulation of hyaluronan synthesis, degradation and binding promotes breast cancer

Clinical and experimental data indicate that hyaluronan accumulates in breast cancer compared with normal breast epithelium, which correlates to poor prognosis. In this review, we discuss the expression of genes encoding enzymes that synthesize or degrade hyaluronan, i.e. hyaluronan synthases and hyaluronidases or bind hyaluronan, i.e. CD44 and receptor for hyaluronan-mediated motility (RHAMM, also designated as HMMR or CD168), in relation to breast cancer progression. Hyaluronan and hyaluronan receptors have multi-faceted roles in signalling events in breast cancer. A better understanding of the molecular mechanisms underlying these signalling pathways is highly warranted and may lead to improvement of cancer treatment.

High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat

The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years^1–3. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years^4,5. In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer^2,6. Here we identify a mechanism responsible for the naked mole-rat’s cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high molecular weight hyaluronan (HA), which is over five times larger than human or mouse HA. This high molecular weight HA accumulates abundantly in naked mole rat tissues due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signaling, as the naked mole rat cells have a higher affinity to HA than the mouse or human cells. Perturbation of the signaling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high molecular weight HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, Hyal2, naked mole-rat cells become susceptible to malignant transformation and readily form tumors in mice. We speculate that naked mole-rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

Glycosaminoglycan regulation by VEGFA and VEGFC of the glomerular microvascular endothelial cell glycocalyx in vitro

Damage to endothelial glycocalyx impairs vascular barrier function and may contribute to progression of chronic vascular disease. An early indicator is microalbuminuria resulting from glomerular filtration barrier damage. We investigated the contributions of hyaluronic acid (HA) and chondroitin sulfate (CS) to glomerular microvascular endothelial cell (GEnC) glycocalyx and examined whether these are modified by vascular endothelial growth factors A and C (VEGFA and VEGFC). HA and CS were imaged on GEnCs and their resynthesis was examined. The effect of HA and CS on transendothelial electrical resistance (TEER) and labeled albumin flux across monolayers was assessed. Effects of VEGFA and VEGFC on production and charge characteristics of glycosaminoglycan (GAG) were examined via metabolic labeling and liquid chromatography. GAG shedding was quantified using Alcian Blue. NDST2 expression was examined using real-time PCR. GEnCs expressed HA and CS in the glycocalyx. CS contributed to the barrier to both ion (TEER) and protein flux across the monolayer; HA had only a limited effect. VEGFC promoted HA synthesis and increased the charge density of synthesized GAGs. In contrast, VEGFA induced shedding of charged GAGs. CS plays a role in restriction of macromolecular flux across GEnC monolayers, and VEGFA and VEGFC differentially regulate synthesis, charge, and shedding of GAGs in GEnCs. These observations have important implications for endothelial barrier regulation in glomerular and other microvascular beds.

Selective matrix (hyaluronan) interaction with CD44 and RhoGTPase signaling promotes keratinocyte functions and overcomes age-related epidermal dysfunction

BACKGROUND

Mouse epidermal chronologic aging is closely associated with aberrant matrix (hyaluronan, HA)-size distribution/production and impaired keratinocyte proliferation/differentiation, leading to a marked thinning of the epidermis with functional consequence that causes a slower recovery of permeability barrier function.

OBJECTIVE

The goal of this study is to demonstrate mechanism-based, corrective therapeutic strategies using topical applications of small HA (HAS) and/or large HA (HAL) [or a sequential small HA (HAS) and large HA(HAL) (HAs→HAL) treatment] as well as RhoGTPase signaling perturbation agents to regulate HA/CD44-mediated signaling, thereby restoring normal epidermal function, and permeability barrier homeostasis in aged mouse skin.

METHODS

A number of biochemical, cell biological/molecular, pharmacological and physiological approaches were used to investigate matrix HA-CD44-mediated RhoGTPase signaling in regulating epidermal functions and skin aging.

RESULTS

In this study we demonstrated that topical application of small HA (HAS) promotes keratinocyte proliferation and increases skin thickness, while it fails to upregulate keratinocyte differentiation or permeability barrier repair in aged mouse skin. In contrast, large HA (HAL) induces only minimal changes in keratinocyte proliferation and skin thickness, but restores keratinocyte differentiation and improves permeability barrier function in aged epidermis. Since neither HAS nor HAL corrects these epidermal defects in aged CD44 knock-out mice, CD44 likely mediates HA-associated epidermal functions in aged mouse skin. Finally, blockade of Rho-kinase activity with Y27632 or protein kinase-Nγ activity with Ro31-8220 significantly decreased the HA (HAS or HAL)-mediated changes in epidermal function in aged mouse skin.

CONCLUSION

The results of our study show first that HA application of different sizes regulates epidermal proliferation, differentiation and barrier function in aged mouse skin. Second, manipulation of matrix (HA) interaction with CD44 and RhoGTPase signaling could provide further novel therapeutic approaches that could be targeted for the treatment of various aging-related skin disorders.

Hyaluronidases and their inhibitors in the serum of colorectal carcinoma patients

Colorectal cancer is the third most commonly diagnosed type of cancer. Hyaluronan is involved in this malignancy. Moreover, hyaluronidases - its degrading enzymes - display controversial roles regarding their involvement in tumor development. HYAL-1 is the major tumor derived hyaluronidase. The aim of the study was the determination and evaluation of hyaluronidase levels in serum of colorectal cancer patients, before and after surgery, with a view to assessing its potential role as a tumor marker for recurrence. By zymography and Western blotting, it was confirmed that HYAL-1 was the only hyaluronidase present in samples. Quantification of its activity indicated a statistically significant decrease in samples seven days postoperatively, compared with the respective ones before surgery. HYAL-1 levels before surgery were significantly reduced in comparison with healthy samples and samples one year postoperatively. Hyaluronidase inhibitor activity was demonstrated under mild alkaline conditions via reverse zymography. A statistically significant increase was observed in samples seven days postoperatively, when compared with samples before surgery. HYAL-1 levels in sera of colorectal cancer patients were lower than those of healthy population, possibly because of the local accumulation of the enzyme in tumor microenvironment. A gradual elevation up to one year postoperatively to reach healthy levels might indicate a role of HYAL-1 levels in cancer.