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

Modular preparation of biphenyl triazoles via click chemistry as non-competitive hyaluronidase inhibitors

Hyaluronidase is a promising target in drug discovery, given its overexpression in a range of physiological and pathological processes, including tumor migration, skin aging, sagging, and wrinkling, as well as inflammation and bacterial infections. In this study, to identify novel hyaluronidase inhibitors, we applied click chemistry for the modular synthesis of 370 triazoles in 96-well plates, starting with biphenyl azide. Utilizing an optimized turbidimetric screening assay in microplates, we identified Fmoc-containing triazoles 5 and 6, as well as quinoline-containing triazoles 15 and 16, as highly effective hyaluronidase inhibitors. Subsequent research indicated that these triazoles potentially interact with a novel binding site of hyaluronidase. Notably, these inhibitors displayed minimal cytotoxicity and showed promising anti-inflammatory effects in LPS-stimulated macrophages. Remarkably, compound 6 significantly reduced NO release by 74 % at a concentration of 20 μM.

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

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

Research on the biological mechanism and potential application of CEMIP

Cell migration-inducing protein (CEMIP), also known as KIAA1199 and hyaluronan-binding protein involved in hyaluronan depolymerization, is a new member of the hyaluronidase family that degrades hyaluronic acid (HA) and remodels the extracellular matrix. In recent years, some studies have reported that CEMIP can promote the proliferation, invasion, and adhesion of various tumor cells and can play an important role in bacterial infection and arthritis. This review focuses on the pathological mechanism of CEMIP in a variety of diseases and expounds the function of CEMIP from the aspects of inhibiting cell apoptosis, promoting HA degradation, inducing inflammatory responses and related phosphorylation, adjusting cellular microenvironment, and regulating tissue fibrosis. The diagnosis and treatment strategies targeting CEMIP are also summarized. The various functions of CEMIP show its great potential application value.

CEMIP (HYBID, KIAA1199): structure, function and expression in health and disease

CEMIP (cell migration-inducing protein), also known as KIAA1199 or HYBID, is a protein involved in the depolymerisation of hyaluronic acid (HA), a major glycosaminoglycan component of the extracellular matrix. CEMIP was originally described in patients affected by nonsyndromic hearing loss and has subsequently been shown to play a key role in tumour initiation and progression, as well as arthritis, atherosclerosis and idiopathic pulmonary fibrosis. Despite the vast literature associating CEMIP with these diseases, its biology remains elusive. The present review article summarises all the major scientific evidence regarding its structure, function, role and expression, and attempts to cast light on a protein that modulates EMT, fibrosis and tissue inflammation, an unmet key aspect in several inflammatory disease conditions.

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.

Expression and regulation of recently discovered hyaluronidases, HYBID and TMEM2, in chondrocytes from knee osteoarthritic cartilage

Destruction of articular cartilage in osteoarthritis (OA) is initiated by depletion of the hyaluronan (HA)-aggrecan network, followed by degradation of the collagen fibrils. Previously, we reported the implications of HA-binding protein involved in HA depolymerization (HYBID), alias cell migration-inducing protein (CEMIP) and KIAA1199, for HA degradation. However, transmembrane protein 2 (TMEM2), which is ~ 50% homologous to HYBID, was discovered as another hyaluronidase, but their expression and regulation by OA chondrocytes remain elusive. Here we report that the absolute mRNA copy numbers of HYBID are significantly (7.1-fold) higher in OA cartilage than normal cartilage, whereas TMEM2 levels are not different between the groups. HA-degrading activity of cultured OA chondrocytes disappeared by siRNA-mediated knockdown of HYBID, but not TMEM2. HYBID expression was significantly up-regulated by treatment with interleukin-6 (IL-6) or tumor necrosis factor-α (TNF-α) and additively increased by the combined treatment. No significant changes in the TMEM2 expression were seen by the factors examined. IL-1α remarkably enhanced IL-6 production and increased HYBID expression when soluble IL-6 receptor was supplemented. These results demonstrate that in stark contrast to the constitutive expression of TMEM2 and its negligible HA-degrading activity, HYBID is overexpressed in OA cartilage and up-regulated by IL-6 and TNF-α in OA chondrocytes.

Insights into the source, mechanism and biotechnological applications of hyaluronidases

It has long been found that hyaluronidases exist in a variety of organisms, playing their roles in various biological processes including infection, envenomation and metabolic regulation through degrading hyaluronan. However, exploiting them as a bioresource for specific applications had not been extensively studied until the latest decades. In recent years, new application scenarios have been developed, which extended the field of application, and emphasized the research value of hyaluronidase. This critical review comprehensively summarizes existing studies on hyaluronidase from different source, particularly in their structures, action patterns, and biological functions in human and mammals. Furthermore, we give in-depth insight into the resource mining and protein engineering process of hyaluronidase, as well as strategies for their high-level production, indicating that mixed strategies should be adopted to obtain well-performing hyaluronidase with efficiency. In addition, advances in application of hyaluronidase were summarized and discussed. Finally, prospects for future researches are proposed, highlighting the importance of further investigation into the characteristics of hyaluronidases, and the necessity of investigating their products for the development of their application value.

Human organ rejuvenation by VEGF-A: Lessons from the skin

Transplanting aged human skin onto young SCID/beige mice morphologically rejuvenates the xenotransplants. This is accompanied by angiogenesis, epidermal repigmentation, and substantial improvements in key aging-associated biomarkers, including ß-galactosidase, p16^ink4a, SIRT1, PGC1α, collagen 17A, and MMP1. Angiogenesis- and hypoxia-related pathways, namely, vascular endothelial growth factor A (VEGF-A) and HIF1A, are most up-regulated in rejuvenated human skin. This rejuvenation cascade, which can be prevented by VEGF-A-neutralizing antibodies, appears to be initiated by murine VEGF-A, which then up-regulates VEGF-A expression/secretion within aged human skin. While intradermally injected VEGF-loaded nanoparticles suffice to induce a molecular rejuvenation signature in aged human skin on old mice, VEGF-A treatment improves key aging parameters also in isolated, organ-cultured aged human skin, i.e., in the absence of functional skin vasculature, neural, or murine host inputs. This identifies VEGF-A as the first pharmacologically pliable master pathway for human organ rejuvenation in vivo and demonstrates the potential of our humanized mouse model for clinically relevant aging research.

Hyaluronan network: a driving force in cancer progression

Hyaluronan is one of the most abundant macromolecules of the extracellular matrix and regulates several physiological cell and tissue properties. However, hyaluronan has been shown to accumulate together with its receptors in various cancers. In tumors, accumulation of hyaluronan system components (hyaluronan synthesizing/degrading enzymes and interacting proteins) associates with poor outcomes of the patients. In this article, we review the main roles of hyaluronan in normal physiology and cancer, and further discuss the targeting of hyaluronan system as an applicable therapeutic strategy.

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.

Antiwrinkle efficacy of 1-ethyl-β-N-acetylglucosaminide, an inducer of epidermal hyaluronan production

BACKGROUND

Hyaluronan (HA) has a unique hydration capacity that contributes to firmness and bounciness of the skin. Epidermal HA declines with skin aging, which may lead to clinical signs of aging including skin wrinkles and loss of hydration and elasticity. Recently, we developed a new cosmetic agent 1-ethyl-β-N-acetylglucosaminide (β-NAG2), which enhances HA production in cultured human keratinocytes. The aim of this study was to explore antiaging potential of β-NAG2 in reconstructed human epidermal models and human clinical trial.

MATERIALS AND METHODS

The amount of HA in β-NAG2-treated epidermal models by topical application was analyzed by enzyme-linked immunosorbent assay (ELISA)-like assay. A randomized, double-blind and placebo-controlled study was conducted in Japanese females (n = 33) by topically treating each side of the face with a lotion formulated with β-NAG2 or placebo for 8 weeks.

RESULTS

Topically applied β-NAG2 dose dependently increased HA production in epidermal models. Treatment with β-NAG2-formulated lotion significantly improved skin hydration and elasticity and reduced skin wrinkling in crow's foot areas when compared to the placebo formulation.

CONCLUSION

Topically applied β-NAG2 promoted epidermal HA production in vitro and showed antiwrinkle activity in vivo accompanying the improvement in skin hydration and elasticity. Our study provides a novel strategy for antiwrinkle care through β-NAG2-induced epidermal HA production.

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

Basement Membrane Helps Maintain Epidermal Hyaluronan Content

Hyaluronan (HA) is the major glycosaminoglycan in the extracellular matrix of most mammalian tissues, including the epidermis. It is synthesized in epidermis, and mainly metabolized after transfer to the liver via lymphatic vessels in the dermis following its passage through the basement membrane (BM) at the dermal-epidermal junction. The aim of the present study was to investigate the influence of BM integrity on the level of HA in the epidermis. Epidermal HA content was decreased in sun-exposed skin of older subjects, whose BM structure was impaired, compared with sun-exposed young skin and sun-protected skin, in which BM integrity was well maintained. In an organotypic culture model of sun-exposed facial skin, epidermal HA was increased in the presence of inhibitors of BM-degrading matrix metalloproteinases and heparanase. In a skin equivalent model treated with these inhibitors, HA content was increased in the epidermis, but decreased in conditioned medium. These findings suggest that the BM at the dermal-epidermal junction plays an important role in maintaining epidermal HA levels.

A guide to the composition and functions of the extracellular matrix

Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.

The Attenuated Secretion of Hyaluronan by UVA-Exposed Human Fibroblasts Is Associated with Up- and Downregulation of HYBID and HAS2 Expression via Activated and Inactivated Signaling of the p38/ATF2 and JAK2/STAT3 Cascades

Little is known about the effects on hyaluronan (HA) metabolism of UVA radiation. This study demonstrates that the secretion of HA by human dermal fibroblasts (HDFs) is downregulated by UVA, accompanied by the down- and upregulation of mRNA and protein levels of the HA-synthesizing enzyme (HAS2) and the HA-degrading protein, HYaluronan Binding protein Involved in HA Depolymerization(HYBID), respectively. Signaling analysis revealed that the exposure distinctly elicits activation of the p38/MSK1/CREB/c-Fos/AP-1 axis, the JNK/c-Jun axis, and the p38/ATF-2 axis, but downregulates the phosphorylation of NF-kB and JAK/STAT3. A signal inhibition study demonstrated that the inhibition of p38 significantly abrogates the UVA-accentuated mRNA level of HYBID. Furthermore, the inhibition of STAT3 significantly downregulates the level of HAS2 mRNA in non-UVA exposed HDFs. Analysis using siRNAs demonstrated that transfection of ATF-2 siRNA but not c-Fos siRNA abrogates the increased protein level of HYBID in UVA-exposed HDFs. An inhibitor of protein tyrosine phosphatase but not of protein serine/threonine phosphatase restored the diminished phosphorylation level of STAT3 at Tyr 705, accompanied by a significant abolishing effect on the decreased mRNA expression level of HAS2. Silencing with a protein tyrosine phosphatase PTP-Meg2 siRNA revealed that it abrogates the decreased phosphorylation of STAT3 at Tyr 705 in UVA-exposed HDFs. These findings suggest that the UVA-induced decrease in HA secretion by HDFs is attributable to the down- and upregulation of HAS2 and HYBID expression, respectively, changes that are mainly ascribed to the inactivated signaling of the STAT3 axis due to the activated tyrosine protein phosphatase PTP-Meg2 and the activated signaling of the p38/ATF2 axis, respectively.

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

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

Depth-resolved investigation of multiple optical properties and wrinkle morphology in eye-corner areas with multi-contrast Jones matrix optical coherence tomography

BACKGROUND

Multi-contrast Jones matrix optical coherence tomography (JM-OCT) can provide quantitative depth-resolved local optical properties by improving the measurement algorithm.

MATERIALS AND METHODS

We examined the relationship between depth-resolved local optical properties of eye-corner skin measured by JM-OCT and corresponding wrinkle morphology of aged women (n = 21; age range, 71.7 ± 1.7 years). Wrinkle morphology was analyzed by measuring the surface topography of three-dimensional replicas. The same regions were measured three-dimensionally by JM-OCT, and the local optical properties at each depth were computed.

RESULTS

Birefringence (BR) and mean wrinkle depth correlated significantly at a depth of 88.2-138.6 µm from the skin surface, and attenuation coefficient (AC) and mean wrinkle depth correlated significantly at a depth of 12.6-18.9 µm and 189-459.9 μm from the skin surface, although a degree of polarization uniformity (DOPU) did not. Stepwise multiple regression analysis demonstrated that a significant regression equation (R²  = 0.649, P < .001) for predicting mean wrinkle depth was determined by BR at 107.1 µm depth (BR _{107.1 µm} ), DOPU at 170.1 µm (DOPU _170.1µm ), and AC at 252 µm (AC _{252 µm} ) as independent variables and that these standardized beta regression coefficients were -0.860, -0.593, and -0.440, respectively, suggesting that BR, DOPU, and AC sufficiently explained mean wrinkle depth.

CONCLUSION

These results suggest that BR _{107.1 µm} , DOPU _{170.1 µm,} and AC _{252 µm} may indicate collagen-related structure in the papillary, upper-reticular dermis, and microstructure or tissue density in reticular dermis, respectively, and may be involved in wrinkle formation.

Distinct differences in hypoxic responses between human oral mucosa and skin fibroblasts in a 3D collagen matrix

The differences between oral mucosa and skin wound healing involving hypoxic responses of fibroblasts are poorly elucidated. In this study, we aimed to study the different hypoxic responses between oral and skin fibroblasts embedded in a three-dimensional (3D) collagen matrix to address the early stage of wound healing. Primary oral mucosa fibroblasts (OMFs) obtained from the retromolar area and skin fibroblasts (SFs) obtained from the abdomen were cultured in the 3D 'floating model' under either 21%, 5% or 1% O₂ for 2 days. Cell viability under hypoxia was higher in the OMFs than in the SFs. Collagen gel contraction was suppressed under hypoxic conditions in both fibroblasts, consistent with the reduction of alpha smooth muscle actin expression, except for SFs under 1% O₂. Subsequently, their gene expression profiles between 21 and 1% O₂ concentrations were compared via microarray technology, and the expression profiles of the extracellular matrix (ECM)-associated proteins, including matrix metalloproteinases and collagens, were evaluated. The OMFs were more susceptible to 1% O₂, and more of their genes were downregulated than the SFs'. Although the production and expression levels of ECM-associated proteins in both fibroblasts diminished under hypoxia, those levels in OMFs were significantly higher than those in SFs. In the case of single origin OMFs and SFs, our findings suggest that OMFs possess a higher baseline production capacity of several ECM-associated proteins than SFs, except type III collagen. The intrinsic hypoxic responses of OMFs may be attributed to a more favourable wound healing in oral mucosa.

Comprehensive histological investigation of age-related changes in dermal extracellular matrix and muscle fibers in the upper lip vermilion

OBJECTIVE

Few histological studies have directly examined age-related changes within the lips, although non-invasive investigations of such changes are increasing. Therefore, this study aimed to provide histological and molecular data on age-dependent alterations in the vermilion.

METHODS

Upper vermilion specimens from 15 female Caucasian cadavers (age range, 27-78 years) were investigated histologically or immunohistochemically.

RESULTS

Histologically, age-dependent decreases in areas occupied by hyaluronan and collagenous fibres in the dermis of upper vermilion were demonstrated. Elastic fibre content varied widely between individuals. The area occupied by muscle fibres in the orbicularis oris muscle region within the vermilion also correlated negatively with age. Immunohistochemically, signals of four proteins were attenuated in vermilion from older individuals compared with young individuals: procollagen type I, hyaluronan synthase (HAS)1, myosin heavy chain (MYH)2 (a component of fast-twitch oxidative muscle fibres) and MYH7 (a component of slow-twitch muscle fibres). In contrast, signals of cell migration inducing hyaluronidase 1 (CEMIP) were intensified in vermilion from older individuals. No marked differences between young and older individuals were seen in procollagen type III, HAS2, HAS3, hyaluronidase (HYAL)1, HYAL2, MYH1 or MYH4.

CONCLUSION

Age-dependent decreases of hyaluronan in the dermis of vermilion were prominent, possibly due to both the decrease in synthesis (HAS1) and the increase in degradation (CEMIP). Furthermore, age-dependent decreases in collagenous fibres and two types of muscle fibre in the vermilion were also identified histologically. Type I collagen, MYH2 and MYH7 appear to represent the molecules responsible for these respective decrements.

Mycosporine-like amino acids stimulate hyaluronan secretion by up-regulating hyaluronan synthase 2 via activation of the p38/MSK1/CREB/c-Fos/AP-1 axis

Hyaluronan (HA) is an extracellular matrix glycosaminoglycan that critically supports the physicochemical and mechanical properties of the skin. Here, we demonstrate that mycosporine-like amino acids (MAAs), which typically function as UV-absorbing compounds, can stimulate HA secretion from normal human fibroblasts. MAA-stimulated HA secretion was associated with significantly increased and decreased levels of mRNAs encoding HA synthase 2 (HAS2) and the HA-binding protein involved in HA depolymerization (designated HYBID), respectively. Using immunoblotting, we found that MAAs at 10 and at 25 μg/ml stimulate the phosphorylation of the mitogen-activated protein kinase (MAPK) p38, extracellular signal-regulated kinase (ERK)/c-Jun, and mitogen- and stress-activated protein kinase 1 (MSK1) (at Thr-581, Ser-360, and Ser-376, respectively) and activation of cAMP-responsive element-binding protein (CREB) and activating transcription factor 2 (ATF2), but not phosphorylation of JUN N-terminal kinase (JNK) or NF-κB (at Ser-276 or Ser-536, respectively), and increased c-Fos protein levels. Moreover, a p38-specific inhibitor, but not inhibitors of MAPK/ERK kinase (MEK), JNK, or NF-κB, significantly abrogated the increased expression of HAS2 mRNA, accompanied by significantly decreased MAA-stimulated HA secretion. These results suggested that the p38-MSK1-CREB-c-Fos-transcription factor AP-1 (AP-1) or the p38-ATF2 signaling cascade is responsible for the MAA-induced stimulation of HAS2 gene expression. Of note, siRNA-mediated ATF2 silencing failed to abrogate MAA-stimulated HAS2 expression, and c-Fos silencing abolished the increased expression of HAS2 mRNA. Our findings suggest that MAAs stimulate HA secretion by up-regulating HAS2 mRNA levels through activation of an intracellular signaling cascade consisting of p38, MSK1, CREB, c-Fos, and AP-1.

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.

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.

Hyaluronan as tunable drug delivery system

The hyaluronan (HA) polymer is an important macromolecule of extracellular matrix with remarkable structure and functions: it is a linear and unbranched polymer without sulphate or phosphate groups and has key role in several biological processes in mammals. It is ubiquitous in mammalian tissues with several and specific functions, influencing cell proliferation and migration as well as angiogenesis and inflammation. To exert these important functions in tissues HA modifies the concentration and size. Considering this HA content in tissues is carefully controlled by different mechanisms including covalent modification of the synthetic enzymes and epigenetic control of their gene expression. The function of HA is also critical in several pathologies including cancer, diabetes and chronic inflammation. Among these biological roles, the structural properties of HA allow to use this polymer in regenerative medicine including cosmetics and drug delivery. HA takes advantage from its capacity to form gels even at concentration of 1% producing scaffolds with very intriguing mechanical properties. These hydrogels are useful in regenerative medicine as biocompatible material for advanced therapeutic uses. In this review we highlight the biological aspects of HA addressing the mechanisms controlling the HA content in tissues and its role as drug delivery system.

Inhibitory effects of Sanguisorba officinalis root extract on HYBID (KIAA1199)-mediated hyaluronan degradation and skin wrinkling

OBJECTIVES

Hyaluronan (HA), an important constituent of extracellular matrix in the skin, has many biological activities such as hydration that contributes to firmness and bounciness of the skin. We have reported that reduction in HA in the papillary dermis and over-expression of HYBID (HYaluronan Binding protein Involved in hyaluronan Depolymerization, alias KIAA1199 or CEMIP), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling in Japanese and Caucasian women. However, little or no information is available for substances which inhibit the HYBID-mediated HA degradation.

METHODS

Inhibition of Sanguisorba officinalis root extract and ziyuglycoside I, one of the components of Sanguisorba officinalis root extract, to the HYBID-mediated HA degradation was assessed by size-exclusion chromatography of HA depolymerized by stable transfectants of HYBID in HEK293 cells (HYBID/HEK293 cells) or normal human skin fibroblasts (Detroit 551 cells and NHDF-Ad cells). The HYBID mRNA and protein expression was examined by quantitative real-time PCR and immunoblotting in the skin fibroblasts treated with Sanguisorba officinalis root extract, and size distribution of newly produced HA was evaluated by preparing metabolically radiolabelled HA. A double-blind, randomized and placebo-controlled study was carried out in the 21 healthy Japanese women, who were topically treated with the formulation containing Sanguisorba officinalis root extract or the placebo on each side of the face including crow's foot area.

RESULTS

Sanguisorba officinalis root extract, but not ziyuglycoside I, abolished HYBID-mediated HA degradation by HYBID/HEK293 cells. Sanguisorba officinalis root extract also inhibited HYBID-mediated HA degradation in skin fibroblasts by down-regulating HYBID mRNA and protein expression. Although control untreated skin fibroblasts produced polydispersed HA, the cells treated with Sanguisorba officinalis root extract produced only high-molecular-weight HA. Treatment with Sanguisorba officinalis root extract-formulated lotion significantly improved skin elasticity, and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation.

CONCLUSION

Sanguisorba officinalis root extract showed an anti-HYBID-mediated HA degradation activity and anti-wrinkle activity on human facial skin, which is accompanied by the improvement in elasticity. Our study provides the possibility of a new strategy to inhibit HYBID-mediated HA degradation for anti-wrinkle care.

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.

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.