Putative hyaluronan synthase mRNA are expressed in mouse skin and TGF-beta upregulates their expression in cultured human skin cells

Epidermal keratinocytes regulate hyaluronan metabolism via extracellularly secreted hyaluronidase 1 and hyaluronan synthase 3

Hyaluronan (HA) is a high-molecular-weight (HMW) glycosaminoglycan, which is a fundamental component of the extracellular matrix that is involved in a variety of biological processes. We previously showed that the HYBID/KIAA1199/CEMIP axis plays a key role in the depolymerization of HMW-HA in normal human dermal fibroblasts (NHDFs). However, its roles in normal human epidermal keratinocytes (NHEKs) remained unclear. HYBID mRNA expression in NHEKs was lower than that in NHDFs, and NHEKs showed no depolymerization of extracellular HMW-HA in culture, indicating that HYBID does not contribute to extracellular HA degradation. In this study, we found that the cell-free conditioned medium of NHEKs degraded HMW-HA under weakly acidic conditions (pH 4.8). This degrading activity was abolished by hyaluronidase 1 (HYAL1) knockdown but not by HYAL2 knockdown. Newly synthesized HYAL1 was mainly secreted extracellularly, and the secretion of HYAL1 was increased during differentiation, suggesting that epidermal interspace HA is physiologically degraded by HYAL1 according to pH decrease during stratum corneum formation. In HA synthesis, hyaluronan synthase 3 (HAS3) knockdown reduced HA production by NHEKs, and interferon-γ-dependent HA synthesis was correlated with increased HAS3 expression. Furthermore, HA production was increased by TMEM2 knockdown through enhanced HAS3 expression. These results indicate that NHEKs regulate HA metabolism via HYAL1 and HAS3, and TMEM2 is a regulator of HAS3-dependent HA production.

Rosemary extract and rosmarinic acid accelerate elastic fiber formation by increasing the expression of elastic fiber components in dermal fibroblasts

Ultraviolet (UV)-induced skin photoaging is caused by qualitative and quantitative degradation of dermal extracellular matrix components such as collagen and elastic fibers. Elastic fibers are important for maintaining cutaneous elasticity, despite their small amount in the skin. Previously, microfibril-associated protein 4 (MFAP-4), which is downregulated in photoaging dermis, has been found to be essential for elastic fiber formation by interaction with both fibrillin-1 and elastin, which are core components of elastic fiber. In addition, enhanced cutaneous MFAP-4 expression in a human skin-xenografted murine photoaging model protects against UV-induced photodamage accompanied by the prevention of elastic fiber degradation and aggravated elasticity. We therefore hypothesized that the upregulation of MFAP-4 in dermal fibroblasts may more efficiently accelerate elastic fiber formation. We screened botanical extracts for MFAP-4 expression-promoting activity in normal human dermal fibroblasts (NHDFs). We found that rosemary extract markedly promotes early microfibril formation and mature elastic fiber formation along with a significant upregulation of not only MFAP-4 but also fibrillin-1 and elastin in NHDFs. Furthermore, rosmarinic acid, which is abundant in rosemary extract, accelerated elastic fiber formation via upregulation of transforming growth factor β-1. This was achieved by the induction of cAMP response element-binding protein phosphorylation, demonstrating that rosmarinic acid represents one of the active ingredients in rosemary extract. Based on the findings in this study, we conclude that rosemary extract and rosmarinic acid represent promising materials that exert a preventive or ameliorative effect on skin photoaging by accelerating elastic fiber formation.

Carbon dioxide-induced decrease in extracellular pH enhances the production of extracellular matrix components by upregulating TGF-β1 expression via CREB activation in human dermal fibroblasts

Mild acidification caused by transcutaneous administration of carbon dioxide (CO2 ) has been reported to improve some epidermal skin impairments, such as desquamation and inflammation; however, its effects on dermal tissue remain unclear. Here, we examined the effect and mechanism of mild acidity on extracellular matrix (ECM) protein production in normal human dermal fibroblasts (NHDFs). To achieve this, the skin permeability of CO2 and its effect on intradermal pH were evaluated by treating reconstructed human skin equivalents (HSEs) with a CO2 -containing formulation. Additionally, NHDFs were cultured in a pH-adjusted medium (pH 6.5). CO2 successfully permeated HSEs and reduced the intradermal pH. Decreased extracellular pH activated CREB, upregulated TGF-β1 expression, promoted the production of elastic and collagen fibres, and increased hyaluronan concentration in NHDFs. Additionally, the low pH-induced increase in TGF-β1 expression was attenuated via the RNAi-mediated suppression of the expression of CREB1 and proton-sensing G protein-coupled receptors (GPCRs), including GPR4 and GPR65. Moreover, low pH-induced CREB activation was suppressed by the inhibition of the cAMP/PKA and PLC/PKC signalling pathways. Taken together, a CO2 -induced decrease in intradermal pH may promote ECM production in NHDFs via the upregulation of TGF-β1 expression, which was mediated by the activation of the GPCR signalling pathway and CREB, indicating that CO2 could be used to treat ultraviolet radiation-induced photoaging, intrinsic ageing and ECM deterioration.

Human TMEM2 is not a catalytic hyaluronidase, but a regulator of hyaluronan metabolism via HYBID (KIAA1199/CEMIP) and HAS2 expression

Cutaneous hyaluronan (HA) is depolymerized to intermediate sizes in the extracellular matrix, and further fragmented in the regional lymph nodes. Previously, we showed that the HA-binding protein involved in HA depolymerization (HYBID), also known as KIAA1199/CEMIP, is responsible for the first step of HA depolymerization. Recently, mouse transmembrane 2 (mTMEM2) with high structural similarity to HYBID was proposed to be a membrane-bound hyaluronidase. However, we showed that knockdown of human TMEM2 (hTMEM2) conversely promoted HA depolymerization in normal human dermal fibroblasts (NHDFs). Therefore, we examined the HA-degrading activity and function of hTMEM2 using HEK293T cells. We found that human HYBID and mTMEM2, but not hTMEM2, degraded extracellular HA, indicating that hTMEM2 does not function as a catalytic hyaluronidase. Analysis of the HA-degrading activity of chimeric TMEM2 in HEK293T cells suggested the importance of the mouse GG domain. Therefore, we focused on the amino acid residues that are conserved in active mouse and human HYBID and mTMEM2, but are substituted in hTMEM2. The HA-degrading activity of mTMEM2 was abolished when its His248 and Ala303 were simultaneously replaced by the corresponding residues of inactive hTMEM2 (Asn248 and Phe303). In NHDFs, enhancement of hTMEM2 expression by proinflammatory cytokines decreased HYBID expression and increased hyaluronan synthase 2 (HAS2)-dependent HA production. The effects of proinflammatory cytokines were abrogated by hTMEM2 knockdown. Moreover, a decreased HYBID expression by interleukin-1β and transforming growth factor-β was canceled by hTMEM2 knockdown. In conclusion, these results indicate that hTMEM2 is not a catalytic hyaluronidase, but a regulator of HA metabolism.

Effects of the short-term fasting and refeeding on growth-related genes in Japanese eel (Anguilla japonica) larvae

The Japanese eel (Anguilla japonica) spends a long period as the leptocephalus larval form under current rearing conditions. The duration of the larval stage until metamorphosis is influenced by body size and growth; however, little knowledge exists of the regulatory mechanism of growth in eel larvae. The present study focused on growth hormone (GH), insulin-like growth factors (IGFs), and IGF binding protein (IGFBP) as the central regulators of growth in teleost fishes and transforming growth factor-beta 3 (TGF-β3) as a possible key modulator of muscle growth and body component synthesis. Japanese eel IGFBP-1a and TGF-β3, comprising 264 and 411 amino acids, respectively, were cloned. Short-term (5-day) fasting and refeeding experiments were performed to understand changes in growth-related genes affected by nutritional status. The relative expression of gh increased with fasting and subsequently decreased with refeeding to the basal levels of the fed control. Relative igf-1 and igf-2 expression levels were high in the fasted group. Relative igf-1 was reduced after 2-day refeeding, whereas igf-2 decreased to the basal level after 1-day refeeding, suggesting that IGF-1 and IGF-2 might be regulated independently and contribute to postnatal growth in eel larvae. Relative igfbp-1a expression was sharply increased by fasting, whereas tgf-β3 showed high and low values in the fed and fasted groups, respectively. Relative igfbp-1a and tgf-β3 levels were negatively and positively correlated with body size, respectively. These results suggest that igfbp-1a and tgf-β3 are potential indices of growth for exploring optimal rearing conditions to shorten the larval stage in Japanese eels.

UDP-glucose dehydrogenase (UGDH) activity is suppressed by peroxide and promoted by PDGF in fibroblast-like synoviocytes: Evidence of a redox control mechanism

UDP-glucose dehydrogenase (UGDH) generates essential precursors of hyaluronic acid (HA) synthesis, however mechanisms regulating its activity are unclear. We used enzyme histostaining and quantitative image analysis to test whether cytokines that stimulate HA synthesis upregulate UGDH activity. Fibroblast-like synoviocytes (FLS, from N = 6 human donors with knee pain) were cultured, freeze-thawed, and incubated for 1 hour with UDP-glucose, NAD+ and nitroblue tetrazolium (NBT) which allows UGDH to generate NADH, and NADH to reduce NBT to a blue stain. Compared to serum-free medium, FLS treated with PDGF showed 3-fold higher UGDH activity and 6-fold higher HA release, but IL-1beta/TGF-beta1 induced 27-fold higher HA release without enhancing UGDH activity. In selected proliferating cells, UGDH activity was lost in the cytosol, but preserved in the nucleus. Cell-free assays led us to discover that diaphorase, a cytosolic enzyme, or glutathione reductase, a nuclear enzyme, was necessary and sufficient for NADH to reduce NBT to a blue formazan dye in a 1-hour timeframe. Primary synovial fibroblasts and transformed A549 fibroblasts showed constitutive diaphorase/GR staining activity that varied according to supplied NADH levels, with relatively stronger UGDH and diaphorase activity in A549 cells. Unilateral knee injury in New Zealand White rabbits (N = 3) stimulated a coordinated increase in synovial membrane UGDH and diaphorase activity, but higher synovial fluid HA in only 2 out of 3 injured joints. UGDH activity (but not diaphorase) was abolished by N-ethyl maleimide, and inhibited by peroxide or UDP-xylose. Our results do not support the hypothesis that UGDH is a rate-liming enzyme for HA synthesis under catabolic inflammatory conditions that can oxidize and inactivate the UGDH active site cysteine. Our novel data suggest a model where UGDH activity is controlled by a redox switch, where intracellular peroxide inactivates, and high glutathione and diaphorase promote UGDH activity by maintaining the active site cysteine in a reduced state, and by recycling NAD+ from NADH.

Skin dryness induced in the KK-Ay/TaJcl type 2 diabetes mouse model deteriorates following dapagliflozin administration

Various diabetic drugs have been developed as the number of patients with type 2 diabetes has increased. Sodium-glucose cotransporter (SGLT)-2 inhibitors have been developed as novel therapeutic agents. However, SGLT-2 inhibitors cause skin dryness. The mechanism through which SGLT-2 inhibitors cause skin dryness is unknown. The purpose of this study was to investigate the mechanism through which dapagliflozin, a SGLT-2 inhibitor, induces skin dryness. Specific pathogen-free KK-Ay/TaJcl (type 2 diabetes model) mice were orally administered with SGLT-2 inhibitor (dapagliflozin) daily for 4 weeks at a dose of 1 mg/kg/day. Skin dryness induced in KK-Ay/TaJcl mice became severe after dapagliflozin administration. Dapagliflozin treatment decreased collagen type I and hyaluronic acid levels in mice; additionally, it affected the TGF-β/hyaluronan synthase pathway, further reducing hyaluronic acid levels. The results indicate that the reduction in hyaluronic acid levels plays an important role in the occurrence of dry skin in diabetes.

Hyaluronan: A key player or just a bystander in skin photoaging?

Photoaged skin exhibits signs of inflammation, DNA damage and changes in morphology that are visible at the macroscopic and microscopic levels. Photoaging also affects the extracellular matrix (ECM) including hyaluronan (HA), the main polysaccharide component thereof. HA is a structurally simple but biologically complex molecule that serves as a water-retaining component and provides both a scaffold for a number of the proteins of the ECM and the ligand for cellular receptors. The study provides an overview of the literature concerning the changes in HA amount, size and metabolism, and the potential role of HA in photoaging. We also suggest novel HA contributions to photoaging based on our knowledge of the role of HA in other pathological processes, including the senescence and inflammation-triggered ECM reorganization. Moreover, we discuss potential direct or indirect intervention to mitigate photoaging that targets the hyaluronan metabolism, as well as supplementation.

Hyaluronan Functions in Wound Repair That Are Captured to Fuel Breast Cancer Progression

Signaling from an actively remodeling extracellular matrix (ECM) has emerged as a critical factor in regulating both the repair of tissue injuries and the progression of diseases such as metastatic cancer. Hyaluronan (HA) is a major component of the ECM that normally functions in tissue injury to sequentially promote then suppress inflammation and fibrosis, a duality in which is featured, and regulated in, wound repair. These essential response-to-injury functions of HA in the microenvironment are hijacked by tumor cells for invasion and avoidance of immune detection. In this review, we first discuss the numerous size-dependent functions of HA and emphasize the multifunctional nature of two of its receptors (CD44 and RHAMM) in regulating the signaling duality of HA in excisional wound healing. This is followed by a discussion of how HA metabolism is de-regulated in malignant progression and how targeting HA might be used to better manage breast cancer progression.

Pharmacogenomics of hyaluronic acid

Abstract.Introduction: Hyaluronic acid (hyaluronan, HA) has become the most popular tool for improving the skin condition during aging, correcting wrinkles and other cosmetic defects. Objective: Analysis of the results of studies that reflect the pharmacogenomics of the synthesis, degradation, and reception of HA. Materials and methods: We searched for full-text publications in Russian and English in the E-Library, PubMed, Springer, Clinical keys, Google Scholar databases, using keywords and combined word searches (hyaluronic acid, hyaluronan, synthesis, degradation, reception, receptor, genetics), over the past decade. In addition, the review included earlier publications of historical interest. Despite our comprehensive searches of these commonly used databases and search terms, it cannot be excluded that some publications may have been missed. Results: The lecture examines: the role of ha in normal and aging human; genes involved in the synthesis (HAS1, HAS2, HAS3), degradation (HYAL1, HYAL2, HYAL3) and reception of ha (CD44, HARE, RHAMM); as well as the expression of their encoded proteins and enzymes in the skin. Conclusion: Expanding our knowledge of the pharmacogenomics of endogenous ha and increasing the exogenous HA drugs (used in anti-aging therapy and medical cosmetology) on the pharmaceutical market requires taking into account individual, including genetically determined, characteristics of the body of each individual patient to ensure an optimal balance of effectiveness/safety of exogenous HA from the point of view of personalized medicine

Matrix Remodeling and Hyaluronan Production by Myofibroblasts and Cancer-Associated Fibroblasts in 3D Collagen Matrices

The tumor microenvironment is a key modulator in cancer progression and has become a novel target in cancer therapy. An increase in hyaluronan (HA) accumulation and metabolism can be found in advancing tumor progression and are often associated with aggressive malignancy, drug resistance and poor prognosis. Wound-healing related myofibroblasts or activated cancer-associated fibroblasts (CAF) are assumed to be the major sources of HA. Both cell types are capable to synthesize new matrix components as well as reorganize the extracellular matrix. However, to which extent myofibroblasts and CAF perform these actions are still unclear. In this work, we investigated the matrix remodeling and HA production potential in normal human dermal fibroblasts (NHFB) and CAF in the absence and presence of transforming growth factor beta -1 (TGF-β1), with TGF-β1 being a major factor of regulating fibroblast differentiation. Three-dimensional (3D) collagen matrix was utilized to mimic the extracellular matrix of the tumor microenvironment. We found that CAF appeared to response insensitively towards TGF-β1 in terms of cell proliferation and matrix remodeling when compared to NHFB. In regards of HA production, we found that both cell types were capable to produce matrix bound HA, rather than a soluble counterpart, in response to TGF-β1. However, activated CAF demonstrated higher HA production when compared to myofibroblasts. The average molecular weight of produced HA was found in the range of 480 kDa for both cells. By analyzing gene expression of HA metabolizing enzymes, namely hyaluronan synthase (HAS1-3) and hyaluronidase (HYAL1-3) isoforms, we found expression of specific isoforms in dependence of TGF-β1 present in both cells. In addition, HAS2 and HYAL1 are highly expressed in CAF, which might contribute to a higher production and degradation of HA in CAF matrix. Overall, our results suggested a distinct behavior of NHFB and CAF in 3D collagen matrices in the presence of TGF-β1 in terms of matrix remodeling and HA production pointing to a specific impact on tumor modulation.

Effects of pulsed electrical stimulation on growth factor gene expression and proliferation in human dermal fibroblasts

Human dermal fibroblast proliferation plays an important role in skin wound healing, and electrical stimulation (ES) promotes skin wound healing. Although the use of ES for skin wound healing has been investigated, the mechanism underlying the effects of ES on cells is still unclear. This study examined the effects of pulsed electrical stimulation (PES) on human dermal fibroblasts. Normal adult human dermal fibroblasts were exposed to a frequency of 4800 Hz, voltage of 1-5 V, and PES exposure time of 15, 30, and 60 min. Dermal fibroblast proliferation and growth factor gene expression were investigated for 6-48 h post PES. Dermal fibroblast proliferation significantly increased from 24 to 48 h post PES at a voltage of 5 V and PES exposure time of 60 min. Under the same conditions, post PES, platelet-derived growth factor subunit A (PDGFA), fibroblast growth factor 2 (FGF2), and transforming growth factor beta 1 (TGF-β1) expression significantly increased from 6 to 24 h, 12 to 48 h, and 24 to 48 h, respectively. Imatinib, a specific inhibitor of platelet-derived growth factor receptor, significantly inhibited the proliferation of dermal fibroblasts promoted by PES, suggesting that PDGFA expression, an early response of PES, was involved in promoting the cell proliferation. Therefore, PES at 4800 Hz may initially promote PDGFA expression and subsequently stimulate the expression of two other growth factors, resulting in dermal fibroblast proliferation after 24 h or later. In conclusion, PES may activate the cell growth phase of wound healing.

Chemo-Photothermal Combination Cancer Therapy with ROS Scavenging, Extracellular Matrix Depletion, and Tumor Immune Activation by Telmisartan and Diselenide-Paclitaxel Prodrug Loaded Nanoparticles

Extracellular matrix (ECM) accumulating in the tumor microenvironment (TME) is generated by tumor-associated fibroblasts. It can elevate interstitial fluid pressure and form dense barriers in tumor tissues. Consequently, nanocarriers are hindered from permeating into deeper tumor sites. Thus, the programmed drug-releasing nanoparticles, G(TM)PPSP, were developed for TME remodeling and breast cancer therapy. Gelatin nanoparticles were linked with platinum nanoparticles (PtNPs) to obtain G(TM)PPSP with a size of 214.0 ± 5.0 nm. Telmisartan (TM) was loaded in gelatin nanoparticles. Paclitaxel (PTX) was attached to PtNPs via a dual redox responsive diselenide bond. TM release was mediated by MMP-2 because of gelatin degradation in TME, and then intracellular PTX was released because of diselenide linkage fracture triggered by ROS or glutathione. ECM was depleted owing to TGF-β downregulation by TM and direct ablation by the photothermal effect of PtNPs. 4T1 tumor progression was inhibited by PTX chemotherapy, intracellular ROS scavenging of PtNPs, and photothermal therapy (PTT). The tumor spheroid penetration assay proved G(TM)PPSP could permeate into deep tumor regions when MMP-2 existed. In vivo antitumor experiments implied G(TM)PPSP with PTT could inhibit tumor growth effectively and remodel TME via ECM depletion and immunity activation, indicating the potential of G(TM)PPSP-based chemo-photothermal combination therapy for breast cancer treatment.

Tranexamic Acid Protects Ovary and Testis Functions and Ameliorates Osteoporosis in Mice

INTRODUCTION

In a rapidly aging society, the number of people suffering from osteoporosis keeps increasing. However, effective prevention strategies for osteoporosis are not yet currently available.

OBJECTIVE

In this study, we examined the ameliorative effects of tranexamic acid on osteoporosis in 24-month-old mice.

METHODS

During the study period, mice were orally administered tranexamic acid 3 times per week.

RESULTS

Bone mineral density, which is a parameter of osteoporosis, was improved following tranexamic acid administration. In addition, female mice evidenced a stronger phenotypic improvement than male mice. In female mice treated with tranexamic acid, ovary abnormalities were reduced. Furthermore, the levels of transforming growth factor-β, hyaluronic acid, CD44, reactive oxygen species, and apoptosis, as well as the number of infiltrated neutrophils and macrophages in the ovary were lower than those in the control or solvent-administered mice. In addition, 17β-estradiol levels in blood increased when compared with the control or solvent-treated mice. In addition, administration of tranexamic acid to 24-month-old male mice decreased the level of apoptosis in the testis. However, the levels of 17β-estradiol and testosterone in blood increased compared with the control or solvent-administered mice.

CONCLUSIONS

The use of tranexamic acid had an ameliorative effect on osteoporosis, possibly by protecting ovaries and testes.

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

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

A Triticum vulgare Extract Exhibits Regenerating Activity During the Wound Healing Process

Introduction

Chronic skin lesions represent a problem of increasing occurrence, mostly due to the global ageing of the world population. Research in skin care and dermatology is constantly looking for new non-invasive solutions, preferably those based on the use of natural certified products, able to accelerate the spontaneous skin repair mechanisms and without altering the skin normal appearance and functionality. The wound healing process in the skin is finely regulated by several factors and orchestrated mechanisms, which modulate the progression and the fitting of different consequent phases, including haemostasis, inflammation, cell proliferation and tissue remodelling. It was previously shown that a patented Triticum vulgare aqueous extract was able to trigger the skin repair process by stimulating new tissue growth and reducing the expression levels of inflammatory mediators, such as IL-6, TNFα, prostaglandin E2, and nitric oxide.

Methods

Scratch assay was performed in Human Dermal Fibroblasts (HDF). The production of fibronectin was measured by gene expression, protein quantification and localization using specific antibodies in HDF. The polymerization of actin was measured using rhodamin-phalloidin in HDF. The epidermal lipid content was estimated in HaCaT (human spontaneously immortalized keratinocytes) using Nile Red staining and the increasing GBA gene expression and activity was demonstrated by RT-PCR and enzymatic activity assay.

Results

In the present study, it was demonstrated that the T. vulgare extract enhanced cell migration inducing the synthesis of fibronectin, new actin polymerization and stimulating the expression of the Hyaluronan Synthase 2. Furthermore it improved the restoration of the epidermal barrier stimulating lipid synthesis.

Conclusion

In conclusion, we demonstrated that the T. vulgare extract possessed promising potential to be developed as a wound healing promoting agent in skin care and dermatology.

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

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

Ameliorative effect of tranexamic acid on physiological skin aging and its sex difference in mice

An effective method to protect the skin from natural aging is unknown. Therefore, in this study, we examined the ameliorative effects of tranexamic acid on natural skin aging. In addition, we examined the sex difference in the effect exhibited by tranexamic acid. We bred hairless mice without ultraviolet ray irradiation and physical stress for 2 years. During the study period, mice were orally administered tranexamic acid (12 mg/kg/day) three times per week. Development of signs of skin aging was found to be ameliorated by tranexamic acid. Furthermore, synthetic inhibition of plasmin was observed following tranexamic acid treatment. The synthetic reinforcement of hyaluronic acid by an increase in the number of epidermal cells and the degradative inhibition of extracellular matrix (ECM) by matrix metalloproteinase (MMP) suppression were observed. These results indicate that natural skin aging was ameliorated by tranexamic acid via the regulation of the plasmin/TGF-β/epidermal cells/hyaluronic acid and plasmin/MMPs/ECM signal transmission pathways. Taken together, sex difference was observed for the ameliorative effect of tranexamic acid on skin aging, with a stronger effect observed in females than in males. More importantly, we found that the synthesis of hyaluronic acid was stronger in female mice than in male mice.

TGF-β1 upregulates the expression of hyaluronan synthase 2 and hyaluronan synthesis in culture models of equine articular chondrocytes

We investigated the effect of transforming growth factor beta 1 (TGF-β1) on equine hyaluronan synthase 2 (HAS2) gene expression and hyaluronan (HA) synthesis in culture models of articular chondrocytes. Equine chondrocytes were treated with TGF-β1 at different concentrations and times in monolayer cultures. In three-dimensional cultures, chondrocyte-seeded gelatin scaffolds were cultured in chondrogenic media containing 10 ng/mL of TGF-β1. The amounts of HA in conditioned media and in scaffolds were determined by enzyme-linked immunosorbent assays. HAS2 mRNA expression was analyzed by semi-quantitative reverse transcription polymerase chain reaction. The uronic acid content and DNA content of the scaffolds were measured by using colorimetric and Hoechst 33258 assays, respectively. Cell proliferation was evaluated by using the alamarBlue assay. Scanning electron microscopy (SEM), histology, and immunohistochemistry were used for microscopic analysis of the samples. The upregulation of HAS2 mRNA levels by TGF-β1 stimulation was dose and time dependent. TGF-β1 was shown to enhance HA and uronic acid content in the scaffolds. Cell proliferation and DNA content were significantly lower in TGF-β1 treatments. SEM and histological results revealed the formation of a cartilaginous-like extracellular matrix in the TGF-β1-treated scaffolds. Together, our results suggest that TGF-β1 has a stimulatory effect on equine chondrocytes, enhancing HA synthesis and promoting cartilage matrix generation.

Inhibition of HYBID (KIAA1199)-mediated hyaluronan degradation and anti-wrinkle effect of Geranium thunbergii extract

BACKGROUND

Hyaluronan (HA) is an essential constituent of extracellular matrix in the skin. HA reduction in the dermis and overexpression of HYBID (KIAA1199), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling.

AIMS

We aimed to obtain anti-wrinkle agent(s) by screening for inhibition of HYBID-mediated HA degradation.

METHODS

Various plant extracts were screened for inhibition of HA degradation in HYBID-stable transfectants in HEK293 (HYBID/HEK293). Inhibition of HA-degrading activity and HYBID mRNA and protein expression by Geranium thunbergii extract was studied in skin fibroblasts and HYBID/HEK293 cells. Size distribution of newly produced HA was evaluated by preparing metabolically radiolabeled HA in skin fibroblasts. A double-blind, randomized, and placebo-controlled study was performed in healthy Japanese women (n = 21) by topically treating each side of the face with a lotion formulated with G. thunbergii extract or placebo for 8 weeks.

RESULTS

Among the plant extracts tested, only G. thunbergii extract abolished HA depolymerization in skin fibroblasts and HYBID/HEK293 cells by down-regulating HYBID mRNA and protein expression and by inhibiting HYBID-mediated HA-degrading activity. Although untreated skin fibroblasts produced polydispersed HA, G. thunbergii extract-treated cells produced high-molecular-weight HA. Treatment with G. thunbergii extract-formulated lotion significantly improved skin elasticity and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation.

CONCLUSIONS

Geranium thunbergii extract inhibited HYBID-mediated HA degradation in vitro and showed anti-wrinkle activity in vivo accompanying the improvement in skin elasticity. Our study provides a possible strategy for anti-wrinkle care through inhibition of HYBID-mediated HA degradation.

Reduction of hyaluronan and increased expression of HYBID (alias CEMIP and KIAA1199) correlate with clinical symptoms in photoaged skin

BACKGROUND

Hyaluronan (HA) metabolism in skin fibroblasts is mediated by HYBID (hyaluronan binding protein involved in hyaluronan depolymerization, alias CEMIP and KIAA1199) and the HA synthases HAS1 and HAS2. However, photoageing-dependent changes in HA and their molecular mechanisms, and the relationship between HA metabolism and clinical symptoms in photoaged skin remain elusive.

OBJECTIVES

We examined the amount, size and tissue distribution of HA and expression levels of HYBID, HAS1 and HAS2 in photoaged skin, and analysed their relationship with the degree of photoageing.

METHODS

Photoageing-dependent changes of HA were investigated by studying skin biopsies isolated from photoprotected and photoexposed areas of the same donors, and the relationships between HA and photoageing symptoms such as skin wrinkling and sagging were examined.

RESULTS

Skin biopsy specimens showed that the amount and size of HA are decreased in photoexposed skin compared with photoprotected skin, and this was accompanied by increased expression of HYBID and decreased expression of HAS1 and HAS2. Histologically, HA staining in the papillary dermis was decreased in photoexposed skin, showing reverse correlation with HYBID expression. HYBID expression in the photoexposed skin directly correlated with skin roughness and sagging parameters, and the reduced HA staining in the papillary dermis in the photoexposed skin positively correlated with these symptoms.

CONCLUSIONS

These data demonstrate that imbalance between HYBID-mediated HA degradation and HAS-mediated HA synthesis may contribute to enhanced HA catabolism in photoaged skin, and suggest that HYBID-mediated HA reduction in the papillary dermis is related to skin wrinkling and sagging of photoaged skin.

Relationship of hyaluronan and HYBID (KIAA1199) expression with roughness parameters of photoaged skin in Caucasian women

BACKGROUND

Hyaluronan (HA) is an important constituent of extracellular matrix (ECM) in the skin, and HA degradation mediated by HYBID (KIAA1199) is suggested to be implicated in facial skin wrinkling in Japanese women. Ethnic difference in skin wrinkle formation is known between Caucasian and Japanese women, but no information is available for the relations of HA and HYBID expression levels with skin wrinkling in Caucasian women.

METHODS

The skin surface roughness at the eye corner of the Caucasian female subjects was measured, and the skin specimens biopsied from the same areas were subjected to microarray gene analysis, HA staining, and immunohistochemistry for HYBID.

RESULTS

Among the ECM genes and those related to ECM metabolism, only HYBID expression levels positively correlated with the skin roughness parameters. When the skin sample groups with high expression of HYBID or low expression of HYBID were compared, the HA staining intensity and the ratio of HYBID-immunoreactive cells to total cells in the superficial dermis were significantly reduced and increased in the high-HYBID-expression group compared with the low-HYBID-expression group, respectively.

CONCLUSION

Our data suggest that like Japanese women, HYBID-mediated reduction of HA in the superficial dermis is involved in the formation of wrinkles in Caucasian women.

TGF-β1 Is Present at High Levels in Wound Fluid from Breast Cancer Patients Immediately Post-Surgery, and Is Not Increased by Intraoperative Radiation Therapy (IORT)

In patients with low-risk breast cancer, intraoperative radiotherapy (IORT) during breast-conserving surgery is a novel and convenient treatment option for delivering a single high dose of irradiation directly to the tumour bed. However, edema and fibrosis can develop after surgery and radiotherapy, which can subsequently impair quality of life. TGF- β is a strong inducer of the extracellular matrix component hyaluronan (HA). TGF-β expression and HA metabolism can be modulated by irradiation experimentally, and are involved in edema and fibrosis. We therefore hypothesized that IORT may regulate these factors.Wound fluid (WF) draining from breast lumpectomy sites was collected and levels of TGF-β1 and HA were determined by ELISA. Proliferation and marker expression was analyzed in primary lymphatic endothelial cells (LECs) treated with recombinant TGF-β or WF. Our results show that IORT does not change TGF-β1 or HA levels in wound fluid draining from breast lumpectomy sites, and does not lead to accumulation of sHA oligosaccharides. Nevertheless, concentrations of TGF-β1 were high in WF from patients regardless of IORT, at concentrations well above those associated with fibrosis and the suppression of LEC identity. Consistently, we found that TGF-β in WF is active and inhibits LEC proliferation. Furthermore, all three TGF-β isoforms inhibited LEC proliferation and suppressed LEC marker expression at pathophysiologically relevant concentrations.

Given that TGF-β contributes to edema and plays a role in the regulation of LEC identity, we suggest that inhibition of TGF-β directly after surgery might prevent the development of side effects such as edema and fibrosis.

Cartilage Oligomeric Matrix Protein Increases in Photodamaged Skin

Cartilage oligomeric matrix protein (COMP) is a structural component of cartilage. Recent studies have described COMP as a pathogenic factor that promotes collagen deposition in fibrotic skin disorders such as scleroderma and keloid skin. Although collagen, a major dermis component, is thought to decrease in photoaged skin, recent reports have demonstrated the presence of tightly packed collagen fibrils with a structural resemblance to fibrosis in the papillary dermis of photoaged skin. Here we examined how photoaging damage relates to COMP expression and localization in photoaged skin. In situ hybridization revealed an increase in COMP-mRNA-positive cells with the progress of photoaging in preauricular skin (sun-exposed skin). The signal intensity of immunostaining for COMP increased with photoaging in not only the papillary dermis but also the reticular dermis affected by advancing solar elastosis. Immunoelectron microscopy detected the colocalization of COMP with both elastotic materials and collagen fibrils in photoaged skin. Ultraviolet light A irradiation of human dermal fibroblasts induced COMP expression at both the mRNA and protein levels. Ultraviolet light A-induced COMP expression was inhibited by an anti-transforming growth factor-β antibody or SB431542, an activin receptor-like kinase 5 inhibitor. These results suggest that the transforming growth factor-β-mediated upregulation of COMP expression may contribute to the modulation of dermal extracellular matrix in the photoaging process.

PP2B and ERK1/2 regulate hyaluronan synthesis of HT168 and WM35 human melanoma cell lines

Hyaluronan (HA) is the major glycosaminoglycan component of the extracellular matrix in either normal or malignant tissues and it may affect proliferation, motility and differentiation of various cell types. Three isoforms of plasma membrane-bound hyaluronan synthases (HAS 1, 2 and 3) secrete and simultaneously bind pericellular HA. HAS enzymes are subjects of post-translational protein phosphorylation which is believed to regulate their enzymatic activity. In this study, we investigated the HA homeostasis of normal human epidermal melanocytes, HT168 and WM35 human melanoma cell lines and melanoma metastases. HAS2 and HAS3 were detected in all the samples, while the expression of HAS1 was not detectable in any case. Malignant tissue samples and melanoma cell lines contained extra- and intracellular HA abundantly but not normal melanocytes. Applying HA as a chemoattractant facilitated the migration of melanoma cells in Boyden chamber. The amount of HA was reduced upon the inhibition of calcineurin with cyclosporine A (CsA), while the inhibition of ERK1/2 with PD098059 elevated it in both cell lines. The signals of Ser/Thr phosphoproteins at 57 kD were stronger after CsA treatment, while a markedly weaker signal was detected upon inhibition of the MAPK pathway. Our results suggest opposing effects of the two investigated enzymes on the HA homeostasis of melanoma cells. We propose that the dephosphorylation of HAS enzymes targeted by PP2B augments HA production, while their phosphorylation by the activity of MAPK pathway reduces HA synthesis. As the expression of the HA receptor RHAMM was also significantly enhanced by PD098059, the MAPK pathway exerted a complex attenuating effect on HA signalling in the investigated melanoma cells. This observation suggests that the application of MAPK-ERK pathway inhibitors requires a careful therapeutic design in melanoma treatment.

Regulation of Hyaluronan (HA) Metabolism Mediated by HYBID (Hyaluronan-binding Protein Involved in HA Depolymerization, KIAA1199) and HA Synthases in Growth Factor-stimulated Fibroblasts

Regulation of hyaluronan (HA) synthesis and degradation is essential to maintenance of extracellular matrix homeostasis. We recently reported that HYBID (HYaluronan-Binding protein Involved in hyaluronan Depolymerization), also called KIAA1199, plays a key role in HA depolymerization in skin and arthritic synovial fibroblasts. However, regulation of HA metabolism mediated by HYBID and HA synthases (HASs) under stimulation with growth factors remains obscure. Here we report that TGF-β1, basic FGF, EGF, and PDGF-BB commonly enhance total amount of HA in skin fibroblasts through up-regulation of HAS expression, but molecular size of newly produced HA is dependent on HYBID expression levels. Stimulation of HAS1/2 expression and suppression of HYBID expression by TGF-β1 were abrogated by blockade of the MAPK and/or Smad signaling and the PI3K-Akt signaling, respectively. In normal human skin, expression of the TGF-β1 receptors correlated positively with HAS2 expression and inversely with HYBID expression. On the other hand, TGF-β1 up-regulated HAS1/2 expression but exerted only a slight suppressive effect on HYBID expression in synovial fibroblasts from the patients with osteoarthritis or rheumatoid arthritis, resulting in the production of lower molecular weight HA compared with normal skin and synovial fibroblasts. These data demonstrate that although TGF-β1, basic FGF, EGF, and PDGF-BB enhance HA production in skin fibroblasts, TGF-β1 most efficiently contributes to production of high molecular weight HA by HAS up-regulation and HYBID down-regulation and suggests that inefficient down-regulation of HYBID by TGF-β1 in arthritic synovial fibroblasts may be linked to accumulation of depolymerized HA in synovial fluids in arthritis patients.

Hyaluronan's Role in Fibrosis: A Pathogenic Factor or a Passive Player?

Fibrosis is a debilitating condition that can lead to impairment of the affected organ's function. Excessive deposition of extracellular matrix (ECM) molecules is characteristic of most fibrotic tissues. Fibroblasts activated by cytokines or growth factors differentiate into myofibroblasts that drive fibrosis by depositing ECM molecules, such as collagen, fibronectin, and connective tissue growth factor. Transforming growth factor-β (TGF-β) is one of the major profibrotic cytokines which promotes fibrosis by signaling abnormal ECM regulation. Hyaluronan (HA) is a major ECM glycosaminoglycan that is regulated by TGF-β and whose role in fibrosis is emerging. Aside from its role as a hydrating, space filling polymer, HA regulates different cellular functions and is known to have a role in wound healing and inflammation. Importantly, HA deposition is increased in multiple fibrotic diseases. In this review we highlight studies that link HA to fibrosis and discuss what is known about the role of HA, its receptors, and its anabolic and catabolic enzymes in different fibrotic diseases.

Hyaluronan synthase 1: a mysterious enzyme with unexpected functions

Hyaluronan synthase 1 (HAS1) is one of three isoenzymes responsible for cellular hyaluronan synthesis. Interest in HAS1 has been limited because its role in hyaluronan production seems to be insignificant compared to the two other isoenzymes, HAS2 and HAS3, which have higher enzymatic activity. Furthermore, in most cell types studied so far, the expression of its gene is low and the enzyme requires high concentrations of sugar precursors for hyaluronan synthesis, even when overexpressed in cell cultures. Both expression and activity of HAS1 are induced by pro-inflammatory factors like interleukins and cytokines, suggesting its involvement in inflammatory conditions. Has1 is upregulated in states associated with inflammation, like atherosclerosis, osteoarthritis, and infectious lung disease. In addition, both full length and splice variants of HAS1 are expressed in malignancies like bladder and prostate cancers, multiple myeloma, and malignant mesothelioma. Interestingly, immunostainings of tissue sections have demonstrated the role of HAS1 as a poor predictor in breast cancer, and is correlated with high relapse rate and short overall survival. Utilization of fluorescently tagged proteins has revealed the intracellular distribution pattern of HAS1, distinct from other isoenzymes. In all cell types studied so far, a high proportion of HAS1 is accumulated intracellularly, with a faint signal detected on the plasma membrane and its protrusions. Furthermore, the pericellular hyaluronan coat produced by HAS1 is usually thin without induction by inflammatory agents or glycemic stress and depends on CD44–HA interactions. These specific interactions regulate the organization of hyaluronan into a leukocyte recruiting matrix during inflammatory responses. Despite the apparently minor enzymatic activity of HAS1 under normal conditions, it may be an important factor under conditions associated with glycemic stress like metabolic syndrome, inflammation, and cancer.

Analysis of aquaporin 9 expression in human epidermis and cultured keratinocytes

Aquaporin 9 (AQP9) is a member of the aquaglyceroporin family that transports glycerol, urea and other small solutes as well as water. Compared to the expression and function in epidermal keratinocytes of AQP3, another aquaglyceroporin, our knowledge of epidermal AQP9 remains elusive. In this study, we investigated the expression of AQP9 in the human epidermis and cultured keratinocytes. Immunofluorescence studies revealed that AQP9 expression is highly restricted to the stratum granulosum of the human epidermis, where occludin is also expressed at the tight junctions. Interestingly, the AQP3 staining decreased sharply below the cell layers in which AQP9 is expressed. In cultured normal human epidermal keratinocytes (NHEK), knock-down of AQP9 expression in the differentiated cells induced by RNA interference reduced glycerol uptake, which was not as pronounced as was the case with AQP3 knock-down cells. In contrast, similar reduction of urea uptake was detected in AQP9 and AQP3 knock-down cells. These findings suggested that AQP9 expression in NHEK facilitates at least the transport of glycerol and urea. Finally, we analyzed the effect of retinoic acid (RA), a potent stimulator of keratinocyte proliferation, on AQP3 and AQP9 mRNA expression in differentiated NHEK. Stimulation with RA at 1 μM for 24 h augmented AQP3 expression and down-regulated AQP9 expression. Collectively, these results indicate that AQP9 expression in epidermal keratinocytes is regulated in a different manner from that of AQP3.

The decreased secretion of hyaluronan by older human fibroblasts under physiological conditions is mainly associated with the down-regulated expression of hyaluronan synthases but not with the expression levels of hyaluronidases

Although it has been reported that levels of hyaluronan are decreased in the dermis of aged skin, little is known about the cellular mechanism(s) underlying that hyaluronan deficiency. Since hyaluronan is produced by dermal fibroblasts and is secreted into the surrounding dermal tissues, we examined the secretion of hyaluronan by dermal fibroblasts and characterized its cellular mechanism using real-time RT-PCR and western blotting for its synthesizing and degrading enzymes, hyaluronan synthase and hyaluronidase, respectively. The secretion of hyaluronan by dermal fibroblasts derived from differently aged human donors, was higher in the younger human fibroblasts tested (0 and 19 years old) compared to the older human fibroblasts tested (39, 56 and 77 years old). The relative secretion levels of hyaluronan by the different human fibroblasts tested were attributable to the relative expression of hyaluronan synthases 1, 2, 3 but not hyaluronidases 1, 2 enzymes at the gene and protein levels among those fibroblasts. These findings indicate that the deficiency of hyaluronan in the aged dermis might result from the down-regulation in the potential of older human fibroblasts to secrete hyaluronan and that decrease in secretory potential is mainly associated with the down-regulated expression of hyaluronan synthases, especially hyaluronan synthase 2, but not with the expression levels of hyaluronidases.

KIAA1199, a deafness gene of unknown function, is a new hyaluronan binding protein involved in hyaluronan depolymerization

Hyaluronan (HA) has an extraordinarily high turnover in physiological tissues, and HA degradation is accelerated in inflammatory and neoplastic diseases. CD44 (a cell surface receptor) and two hyaluronidases (HYAL1 and HYAL2) are thought to be responsible for HA binding and degradation; however, the role of these molecules in HA catabolism remains controversial. Here we show that KIAA1199, a deafness gene of unknown function, plays a central role in HA binding and depolymerization that is independent of CD44 and HYAL enzymes. The specific binding of KIAA1199 to HA was demonstrated in glycosaminoglycan-binding assays. We found that knockdown of KIAA1199 abolished HA degradation by human skin fibroblasts and that transfection of KIAA1199 cDNA into cells conferred the ability to catabolize HA in an endo-β-N-acetylglucosaminidase-dependent manner via the clathrin-coated pit pathway. Enhanced degradation of HA in synovial fibroblasts from patients with osteoarthritis or rheumatoid arthritis was correlated with increased levels of KIAA1199 expression and was abrogated by knockdown of KIAA1199. The level of KIAA1199 expression in uninflamed synovium was less than in osteoarthritic or rheumatoid synovium. These data suggest that KIAA1199 is a unique hyaladherin with a key role in HA catabolism in the dermis of the skin and arthritic synovium.

The control and importance of hyaluronan synthase expression in palatogenesis

Development of the lip and palate involves a complex series of events that requires the close co-ordination of cell migration, growth, differentiation, and apoptosis. Palatal shelf elevation is considered to be driven by regional accumulation and hydration of glycosoaminoglycans, principally hyaluronan (HA), which provides an intrinsic shelf force, directed by components of the extracellular matrix (ECM). During embryogenesis, the extracellular and pericellular matrix surrounding migrating and proliferating cells is rich in HA. This would suggest that HA may be important in both shelf growth and fusion. TGFβ3 plays an important role in palatogenesis and the corresponding homozygous null (TGFβ3^−/−) mouse, exhibits a defect in the fusion of the palatal shelves resulting in clefting of the secondary palate. TGFβ3 is expressed at the future medial edge epithelium (MEE) and at the actual edge epithelium during E14.5, suggesting a role for TGFβ3 in fusion. This is substantiated by experiments showing that addition of exogenous TGFβ3 can “rescue” the cleft palate phenotype in the null mouse. In addition, TGFβ1 and TGFβ2 can rescue the null mouse palate (in vitro) to near normal fusion. In vivo a TGFβ1 knock-in mouse, where the coding region of the TGFβ3 gene was replaced with the full-length TGFβ1 cDNA, displayed complete fusion at the mid portion of the secondary palate, whereas the anterior and posterior regions failed to fuse appropriately. We present experimental data indicating that the three HA synthase (Has) enzymes are differentially expressed during palatogenesis. Using immunohistochemistry (IHC) and embryo sections from the TGFβ3 null mouse at days E13.5 and E14.5, it was established that there was a decrease in expression of Has2 in the mesenchyme and an increase in expression of Has3 in comparison to the wild-type mouse. In vitro data indicate that HA synthesis is affected by addition of exogenous TGFβ3. Preliminary data suggests that this increase in HA synthesis, in response to TGFβ3, is under the control of the PI3kinase/Akt pathway.

Role of CD44 in tumour progression and strategies for targeting

CD44 or hyaluronan receptor is a transmembrane receptor associated with aggressive tumour growth, proliferation, and metastasis. In normal physiology, this receptor has a crucial role in cell adhesion, inflammation, and repair processes. However, many tumour cells over-express this receptor and abuse it to become progressive and perpetual units. The article comments from common functioning of the CD44 receptor, to its diabolic multi-dimensional effects in promotion of malignant cells. It also illuminates the relations of CD44 endorsed processes with other biomolecular events in cancer progression. In an end, the review focuses comprehensively at ongoing researches to exploit the CD44 over-expression as a probable target in treatment, management, and diagnosis of malignancy.

Transdermal administration of lactoferrin with sophorolipid1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal's usual peer review process

Lactoferrin (Lf), a multifunctional glycoprotein, is known to activate dermal fibroblasts. Enhancing percutaneous absorption without decreasing the activity of Lf is critical in making the dermal administration of Lf beneficial. Sophorolipid (SL), a glycolipid-type biosurfactant, is known to form assemblies that may elevate the efficiency of the transdermal delivery of active ingredients. Here, we investigated the role of SL in the transdermal absorption of bovine Lf (bLf) and the effect of SL on the bLf activity on dermal fibroblasts. Transdermal absorption of bLf through a model skin was enhanced by 1.3-fold to 1.7-fold when SL was added. The effects of SL on the bLf activities on dermal fibroblasts were examined by cell proliferation activities and by gene expression levels of elastic fiber components, collagen IV, and hyaluronan synthases, revealing that SL did not depress the effect of bLf to any extent. Instead, the tropoelastin gene expression was upregulated ∼60-fold by bLf alone, which was further increased to ∼160-fold by bLf and SL together, suggesting a significant synergism between bLf and SL. Protein levels of elastin, assessed by immunohistochemistry, correlated well with the results of gene expressions. These results indicate the feasibility of the transdermal administration of bLf with SL.

Enhanced inflammation and accelerated wound closure following tetraphorbol ester application or full-thickness wounding in mice lacking hyaluronan synthases Has1 and Has3

Hyaluronan (HA) is an abundant matrix molecule, the function of which in the skin remains to be fully defined. To explore the roles of HA in cutaneous injury responses, double-knockout mice (abbreviated as Has1/3 null) that lack two HA synthase enzymes (Has1 and Has3), but still express functional Has2, were used in two types of experiments: (i) application of 12-O-tetradecanoylphorbol-13-acetate (TPA) and (ii) full-thickness wounding of the skin. Uninjured Has1/3-null mice were phenotypically normal. However, after TPA, the accumulation of HA that normally occurs in wild-type epidermis was blunted in Has1/3-null epidermis. In excisional wound-healing experiments, wound closure was significantly faster in Has1/3 null than in wild-type mice. Coincident with this abnormal wound healing, a marked decrease in epidermal and dermal HA and a marked increase in neutrophil efflux from cutaneous blood vessels were observed in Has1/3-null skin relative to wild-type skin. Has1/3-null wounds displayed an earlier onset of myofibroblast differentiation. In summary, selective loss of Has1 and Has3 leads to a proinflammatory milieu that favors recruitment of neutrophils and other inflammation-related changes in the dermis.

Cloning and characterization of human vitreous tissue-derived cells

PURPOSE

Previously, we established a porcine vitreous tissue-derived hyalocyte cell line (PH5) and investigated the regulation of hyaluronan synthesis in these cells by cytokines. The objective of the current study was to establish human vitreous tissue-derived cells and to compare their characteristics with those of PH5 cells.

METHODS

Human vitreous specimens from two patients were cultured in the presence of 10% foetal bovine serum and immortalized by infection with human papilloma virus 16 genes E6 and E7. We used reverse transcription polymerase chain reaction (RT-PCR) to analyse and compare the expression profiles for several genes in the human vitreous tissue-derived cells and PH5 cells. To investigate the regulation of hyaluronan production in response to cytokine stimulation, the expression of hyaluronan synthase isoforms was examined using RT-PCR, and hyaluronan production was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Two types of cells, HV64 and HV65, were derived from human vitreous tissue. The HV64 and HV65 cell-doubling times were 58 r and 76 hr, respectively. The cells expressed messenger RNA (mRNAs) encoding collagen type I α1 (COL1A1), collagen type II α1 (COL2A1), CD11b, CD14, CD68, CD204 and CD206 but did not express mRNA for glial fibrillary acidic protein (GFAP). Cytokine stimulation did not induce the expression of hyaluronan synthase mRNA or the production of hyaluronan. In contrast, mRNAs for GFAP and hyaluronan synthase-2 were expressed in the porcine PH5 cells, and treatment with transforming growth factor-β1 and/or platelet-derived growth factor-BB induced the production of hyaluronan in PH5 cells.

CONCLUSION

The new human vitreous tissue-derived cells have macrophage-like characteristics and are different from our previously developed porcine hyalocyte cells. These human vitreous tissue-derived cells might be useful for studies of human intraocular diseases.

Adiponectin resides in mouse skin and upregulates hyaluronan synthesis in dermal fibroblasts

Adipose tissue is a hormonally active tissue that produces adipokines that influence the activity of other tissues. Adiponectin is an adipocyte-specific adipokine involved in systemic metabolism. We detected the expression of adiponectin receptors (AdipoR1 and AdipoR2) mRNA in cultured dermal fibroblasts. The full-length adiponectin (fAd), but not the globular adiponectin (gAd), increased hyaluronan (HA) production and upregulated HA synthase (HAS) 2 mRNA expression. AdipoR1 and AdipoR2 mRNAs were also expressed in keratinocytes, though neither fAd nor gAd had any effect on HA synthesis. In mouse skin, we found that adiponectin was present and decreased markedly with aging. The age-dependent pattern of adiponectin decrease in skin, correlated well with that of HA in skin. Our experiments were also the first to identify adiponectin production in cultured mouse sebocytes, a finding that suggests that skin adiponectin may derive not only from plasma and/or subcutaneous adipose tissue, but also from the sebaceous gland. These results indicated that adiponectin plays an important role in the HA metabolism of skin.

High-fat diet reduces levels of type I tropocollagen and hyaluronan in rat skin

Although it is known that nutritional conditions affect the skin function, little information is available on the effect of a high-fat (HF) diet on skin. In this study, Sprague-Dawley rats were fed HF diets for 28 days, and we investigated the effect of this diet on type I tropocollagen and hyaluronan in rat skin. The HF diets reduced the levels of type I tropocollagen, COL1A1 mRNA, hyaluronan, and rat hyaluronan synthase (rhas)2 mRNA, which play a primary role in hyaluronan synthase in the dermis. However, rhas3 mRNA level in the skin was increased. The HF diets also decreased the skin mRNA expression of transforming growth factor (TGF)-beta1, which enhances the expression of COL1A1 and rhas2 mRNA and decreases rhas3 mRNA expression, and decreased the hepatic mRNA expression of insulin-like growth factor (IGF)-I, which enhances COL1A1, rhas2, and TGF-beta1 mRNA expression. The serum level of adiponectin, which promotes the syntheses of type I collagen and hyaluronan, was decreased in the HF diet groups. These findings suggest that an HF diet reduces the levels of type I tropocollagen and hyaluronan in the skin by suppressing the action of TGF-beta1, IGF-I and adiponectin, and these effects are deleterious for skin function.

Lactoferrin promotes hyaluronan synthesis in human dermal fibroblasts

Bovine lactoferrin (BLF) enhanced production of hyaluronan in normal human dermal fibroblasts. The elevation of hyaluronan was accompanied by elevation of HAS2 (hyaluronan synthase 2) mRNA transcription and HAS2 protein expression. The promoting effect of BLF was not observed for HAS1. In addition, COL1A1 transcription and collagen synthesis were enhanced by BLF. These observations suggest that BLF promotes wound healing by increasing hyaluronan and type-I collagen synthesis.

Hyaluronic acid metabolism is increased in unstable plaques

BACKGROUND

Hyaluronic acid is expressed in atherosclerotic lesions, but its exact role in atherosclerotic disease remains unknown. As degradation of hyaluronic acid by hyaluronidase into low molecular weight hyaluronic acid (LMW-HA) is associated with inflammation and Matrix Metalloproteinase (MMP)-9 activity, we hypothesized that hyaluronic acid metabolism is increased in plaques with unstable characteristics like large lipid core, high number of macrophages, MMP-9 activity, low collagen and smooth muscle cell content.

MATERIALS AND METHODS

Protein was isolated from 68 carotid artery specimens. The adjacent plaque segment was characterized for the histological parameters: lipid core, macrophage, collagen, smooth muscle cell (SMC) content and the amount of intra-plaque thrombus. Hyaluronidase activity, total hyaluronic acid and LMW-HA expression, the standard hayaluronic acid receptor CD44s and the VEGF-A binding isoform CD44v3, MMP-9 activity and the plaque instability associated growth factor Vascular Endothial Growth Factor (VEGF)-A were analysed and correlated with histological characteristics.

RESULTS

Hyaluronidase activity, LMW-HA and CD44 expression (CD44s, CD44v3) levels were increased in atheromatous plaques compared with fibrous plaques. Total hyaluronic acid did not correlate with plaque instability. MMP-9 activity correlated with CD44s, hyaluronidase and LMW-HA expression. CD44v3 correlated with the angiogenic factor VEGF-A. In vitro stimulation of macrophages with LMW-HA increased MMP-9 activity.

CONCLUSIONS

We show for the first time that increased hyaluronic acid metabolism and elevated CD44 levels are associated with plaque destabilization potentially by increased MMP-9 activity and stimulation of angiogenesis.

Interaction of wingless protein (Wnt), transforming growth factor-beta1, and hyaluronan production in fetal and postnatal fibroblasts

BACKGROUND

Mammalian fetal skin injury heals scarlessly. The intrinsic differences between embryonic and adult fibroblasts that underlie this observation are poorly understood. Several studies have linked Wnt proteins with skin morphogenesis. The authors' study aimed to establish a correlation between beta-catenin-dependent (canonical) Wnt protein, transforming growth factor (TGF)-beta1, and the expression of hyaluronan synthesis enzymes during scarless versus scarring wound healing.

METHODS

Wnt signaling was quantified after 1.5-mm skin wounds were created in BAT-gal fetal (e16.5) and postnatal (p1) mice. Canonical Wnt signals were localized by X-gal staining and quantified with quantitative real-time polymerase chain reaction. Primary embryonic and postnatal mouse dermal fibroblasts were treated with recombinant Wnt3a or TGF-beta1. Proliferation was assayed by bromodeoxyuridine incorporation. Gene expression of enzymes that regulate hyaluronan production and turnover was examined by quantitative real-time polymerase chain reaction (hyaluronan synthases or HAS1-3, hyaluronadase-2), as well as other target genes for Wnt and TGF-beta (Axin2, TGF-beta1, TGF-beta3, type 1 collagen, proliferating cell nuclear antigen).

RESULTS

Canonical Wnt signaling increased following wounding in postnatal, but not fetal, mice. In vitro, rmWnt3a increased postnatal fibroblast proliferation but not in embryonic cells. Both Wnt3a and TGF-beta1 induced HAS2 and HAS3 gene expression in embryonic fibroblasts, while HAS1 and Hyal2 were induced in postnatal fibroblasts. Finally, rmWnt3a significantly increased type I collagen expression, particularly in postnatal fibroblasts, and influenced expression of TGF-beta isoforms.

CONCLUSIONS

Increased canonical Wnt signaling occurs during postnatal but not fetal cutaneous wound repair. Fetal and postnatal fibroblasts have a disparate response to rmWnt3a in vitro. rmWnt3a affects postnatal fibroblasts in a similar fashion to rhTGF-beta1, a known profibrotic cytokine.

Cloning and characterization of cell strains derived from human corneal stroma and sclera

PURPOSE

To establish human corneal stroma- and sclera-derived cells as models for studying diseases of the anterior segment of the eye.

METHODS

Using a recombinant retrovirus system, we transfected human papilloma virus 16 E6 and E7 (HPV16 E6/E7) into human corneal stroma- and sclera-derived cells. The primary cells and established cell strains were characterized by assessing the mRNA expression of collagen, matrix metalloproteinase, and tissue inhibitor of metalloproteinase by reverse transcription-polymerase chain reaction. We also examined the effects of inflammatory cytokines on hyaluronan synthase expression and hyaluronan products.

RESULTS

Both a corneal stroma-derived cell strain, Cs3, and a sclera-derived cell strain, Sc1, were obtained, and both cell strains could be passaged up to 25 times. The mRNA expression pattern observed in the primary cells was identical to that observed in the cell strains. Hyaluronan synthase 1 and 2 mRNAs were increased by transforming growth factor beta and platelet-derived growth factor BB. Significant differences were observed between the hyaluronan products with and without cytokine treatment.

CONCLUSION

Cell strains derived from corneal stroma and sclera fibroblast cells can be established using HPV16 E6/E7 immortalized genes of the same origin. The phenotypic cell characteristics did not change after transfection, immortalization, or successive passages in culture.

Dermal hyaluronan is rapidly reduced by topical treatment with glucocorticoids

Skin atrophy is part of the normal ageing process, but is accelerated by topical glucocorticoid (GC) treatments that are widely used in dermatology. Hyaluronan (HA) is one of the most abundant components of the cutaneous extracellular matrix and is involved in tissue homeostasis, hydration, and repair processes, but little is known about the effects of GCs on HA synthesis and stability. Here we examined the regulation of HA metabolism in human skin during GC therapy. Expression of the HA synthesizing enzymes hyaluronan synthase (HAS)-2 and HAS-3 and the HA degrading enzymes HYAL-1, HYAL-2, and HYAL-3 in response to GC treatment was evaluated. HAS-2 expression was markedly suppressed by dexamethasone treatment of cultured fibroblasts and HaCaT keratinocyte cells, and in human skin biopsies taken from volunteers treated with dexamethasone ointment. Consistently, the HA content of cell culture supernatants and in human skin was reduced after dexamethasone treatment. Hyaluronidase expression and activity, on the other hand, was not altered by dexamethasone treatment. These data show that the levels of skin HA rapidly decrease after short-term GC treatment due to a reduction in HA synthesis, while HA degradation is not changed. This may reflect an initiation of skin atrophy in response to topically applied GCs.