Heparanase activation induces epidermal hyperplasia, angiogenesis, lymphangiogenesis and wrinkles

The Peripheral Lymphatic System Is Impaired by the Loss of Neuronal Control Associated with Chronic Spinal Cord Injury

Spinal cord injury (SCI) is associated with venous vascular dysfunction below the level of injury, resulting in dysregulation of tissue fluid homeostasis in afflicted skin. The purpose of this study was to determine whether loss of neuronal control in chronic SCI also affects the skin lymphatic system. Morphology of lymphatics was characterized by immunohistochemistry and lymphatic gene expression profiles determined by DNA microarray analysis. In SCI, skin lymphatic function appeared to be impaired, because the ratio of functionally dilated versus collapsed lymphatic vessels was decreased 10-fold compared with control. Consequently, the average lumen area of lymphatic vessels was almost halved, possibly due to the known impaired connective tissue integrity of SCI skin. In fact, collagenases were found to be overexpressed in SCI skin, and dermal collagen structure was impaired. Molecular profiling also suggested an SCI-specific phenotype of increased connective tissue turnover and decreased lymphatic contractility. The total number of lymphatic vessels in SCI skin, however, was doubled, pointing to enhanced lymphangiogenesis. In conclusion, these data show, for the first time, that lymphatic function and development in human skin are under neuronal control. Because peripheral venous and lymphatic vascular defects are associated with disturbed fluid homeostasis, inappropriate wound healing reactions, and impaired skin immunity, they might contribute to the predisposition of afflicted individuals to pressure ulcer formation and wound healing disorders.

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.

Reversing wrinkled skin and hair loss in mice by restoring mitochondrial function

Mitochondrial DNA (mtDNA) depletion is involved in mtDNA depletion syndromes, mitochondrial diseases, aging and aging-associated chronic diseases, and other human pathologies. To evaluate the consequences of depletion of mtDNA in the whole animal, we created an inducible mtDNA-depleter mouse expressing, in the polymerase domain of POLG1, a dominant-negative mutation to induce depletion of mtDNA in various tissues. These mice showed reduced mtDNA content, reduced mitochondrial gene expression, and instability of supercomplexes involved in oxidative phosphorylation (OXPHOS) resulting in reduced OXPHOS enzymatic activities. We demonstrate that ubiquitous depletion of mtDNA in mice leads to predominant and profound effects on the skin resulting in wrinkles and visual hair loss with an increased number of dysfunctional hair follicles and inflammatory responses. Development of skin wrinkle was associated with the significant epidermal hyperplasia, hyperkeratosis, increased expression of matrix metalloproteinases, and decreased expression of matrix metalloproteinase inhibitor TIMP1. We also discovered markedly increased skin inflammation that appears to be a contributing factor in skin pathology. Histopathologic analyses revealed dysfunctional hair follicles. mtDNA-depleter mice also show changes in expression of aging-associated markers including IGF1R, KLOTHO, VEGF, and MRPS5. mtDNA-repleter mice showed that, by turning off the mutant POLG1 transgene expression, mitochondrial function, as well as the skin and hair pathology, is reversed to wild-type level. To our knowledge that restoration of mitochondrial functions can reverse the skin and hair pathology is unprecedented.

Perlecan expression influences the keratin 15-positive cell population fate in the epidermis of aging skin

The epidermis is continuously renewed by stem cell proliferation and differentiation. Basal keratinocytes append the dermal‐epidermal junction, a cell surface‐associated, extracellular matrix that provides structural support and influences their behaviour. It consists of laminins, type IV collagen, nidogens, and perlecan, which are necessary for tissue organization and structural integrity. Perlecan is a heparan sulfate proteoglycan known to be involved in keratinocyte survival and differentiation. Aging affects the dermal epidermal junction resulting in decreased contact with keratinocytes, thus impacting epidermal renewal and homeostasis. We found that perlecan expression decreased during chronological skin aging. Our in vitro studies revealed reduced perlecan transcript levels in aged keratinocytes. The production of in vitro skin models revealed that aged keratinocytes formed a thin and poorly organized epidermis. Supplementing these models with purified perlecan reversed the phenomenon allowing restoration of a well‐differentiated multi‐layered epithelium. Perlecan down‐regulation in cultured keratinocytes caused depletion of the cell population that expressed keratin 15. This phenomenon depended on the perlecan heparan sulphate moieties, which suggested the involvement of a growth factor. Finally, we found defects in keratin 15 expression in the epidermis of aging skin. This study highlighted a new role for perlecan in maintaining the self‐renewal capacity of basal keratinocytes.

Heparanase: Potential roles in multiple sclerosis

Heparanase is a heparan sulfate degrading enzyme that cleaves heparan sulfate (HS) chains present on HS proteoglycans (HSPGs), and has been well characterized for its roles in tumor metastasis and inflammation. However, heparanase is emerging as a contributing factor in the genesis and severity of a variety of neurodegenerative diseases and conditions. This is in part due to the wide variety of HSPGs on which the presence or absence of HS moieties dictates protein function. This includes growth factors, chemokines, cytokines, as well as components of the extracellular matrix (ECM) which in turn regulate leukocyte infiltration into the CNS. Roles for heparanase in stroke, Alzheimer's disease, and glioma growth have been described; roles for heparanase in other disease such as multiple sclerosis (MS) are less well established. However, given its known roles in inflammation and leukocyte infiltration, it is likely that heparanase also contributes to MS pathology. In this review, we will briefly summarize what is known about heparanase roles in the CNS, and speculate as to its potential role in regulating disease progression in MS and its animal model EAE (experimental autoimmune encephalitis), which may justify testing of heparanase inhibitors for MS treatment.

Heparanase Inhibitors Facilitate the Assembly of the Basement Membrane in Artificial Skin

Recent research suggests that the basement membrane at the dermal-epidermal junction of the skin plays an important role in maintaining a healthy epidermis and dermis, and repeated damage to the skin can destabilize the skin and accelerate the aging process. Skin-equivalent models are suitable for studying the reconstruction of the basement membrane and its contribution to epidermal homeostasis because they lack the basement membrane and show abnormal expression of epidermal differentiation markers. By using these models, it has been shown that reconstruction of the basement membrane is enhanced not only by supplying basement membrane components, but also by inhibiting proteinases such as urokinase and matrix metalloproteinase. Although matrix metalloproteinase inhibitors assist in the reconstruction of the basement membrane structure, their action is not sufficient to promote its functional recovery. However, heparanase inhibitors stabilize the heparan sulfate chains of perlecan (a heparan sulfate proteoglycan) and promote the regulation of heparan sulfate binding growth factors in the basement membrane. Heparan sulfate promotes effective protein-protein interactions, thereby facilitating the assembly of type VII collagen anchoring fibrils and elastin-associated microfibrils. Using both matrix metalloproteinase inhibitors and heparanase inhibitors, the basement membrane in a skin-equivalent model comes close to recapitulating the structure and function of an in vivo basement membrane. Therefore, by using an appropriate dermis model and suitable protease inhibitors, it may be possible to produce skin-equivalent models that are more similar to natural skin

Evaluation of heparanase and matrix metalloproteinase-9 in patients with cutaneous malignant melanoma

Elevated heparanase and matrix metalloproteinase (MMP)-9, frequently found in human cancer, is a major cause of degradation of the extracellular matrix (ECM) and basement membrane (BM), thus facilitating tumor cell migration and invasion. Although a lot of work has been done, the role of heparanase and MMP-9 has not been delineated in skin cancer progression. The purpose of this study was to do such an exploration. To investigate the role of heparanase and MMP-9 in cutaneous malignant melanoma (CMM) development, we performed immunohistochemical analysis to detect the alternation of these two factors in paraffin-embedded biopsy specimens of normal skin, junctional nevi and CMM. It is interesting to note that the expression profile of heparanase and MMP-9 was similar. Contrary to negative staining in normal skin, overexpression of heparanase and cytoplasmic MMP-9 was observed in as many as 70% of CMM, whereas only 10% of the junctional nevi exhibited faint staining (P = 0.0005, P = 0.0000). Considering the lymph node (LN) metastasis, the expression of the two factors is significantly higher in LN-positive lesions than that in LN-negative lesions (P = 0.0295, P = 0.0013). Meanwhile, there was positive correlation between the expression of MMP-9 and heparanase (r = 0.689, P = 0.003). The first expression of MMP-9 and heparanase occurs at benign lesions. However, the significantly increased expression in advanced CMM stages, particularly in LN-positive metastasis lesions, might synergistically contribute to degradation of ECM and BM, therefore promoting carcinogenesis and metastasis.

Ultraviolet-B irradiation induces epidermal up-regulation of heparanase expression and activity

Heparan sulfate (HS) glycosaminoglycans are abundant components of basement membranes and cell surfaces where they are present associated with specific core-proteins to form proteoglycans, mainly perlecan, glypicans and syndecans. They play many roles such as modulation of cell proliferation and differentiation, cell-matrix adhesion and assembly. It was previously shown that HS content decreases during skin aging. This decrease could be explained either by a decrease of HS synthesis or by an increased activity of its degrading enzyme, heparanase (Hpse-1). Since UV-B irradiation is one of the most important factor for skin photo-damage, we decided to study the effects of UV-B irradiation on heparanase expression and activity in human epidermal keratinocytes. Normal human keratinocytes and reconstructed epidermis were submitted to increasing doses of UV-B. HPSE1 mRNA levels were measured using real time PCR and heparanase enzymatic activity was quantified in human keratinocyte cultures using a microtiter-based assay. Expression and distribution of Hpse-1 were also studied in reconstructed epidermis by immunofluorescence. Both HPSE1 mRNA level and heparanase enzymatic activity were increased after UV-B irradiation of keratinocyte cultures in a time and dose-dependent manner. Protein expression of Hpse-1 was also up-regulated with increasing doses of UV-B in reconstructed epidermis. Increase of Hpse-1 expression and activity in the epidermis after UV-B irradiation could contribute to skin photo-aging.

Activation of heparanase by ultraviolet B irradiation leads to functional loss of basement membrane at the dermal-epidermal junction in human skin

Recently, we reported that heparanase plays important roles in barrier-disrupted skin, leading to increased interaction of growth factors between epidermis and dermis and facilitating various cutaneous changes, including epidermal hyperplasia and wrinkle formation. However, the role of heparanase in sun-exposed skin remains unknown. Here, we show that heparanase in human keratinocytes is activated by ultraviolet B (UVB) exposure and that heparan sulfate of perlecan is markedly degraded in UVB-irradiated human skin. The degradation of heparan sulfate resulted in a marked reduction of binding activity of the basement membrane for vascular endothelial growth factor, fibroblast growth factor-2 and -7 at the dermal-epidermal junction. Degradation of heparan sulfate was observed not only in acutely UVB-irradiated skin, but also in skin chronically exposed to sun. Interestingly, heparan sulfate was found to be degraded in sun-exposed skin, but not in sun-protected skin. These findings suggest that chronic UVB exposure activates heparanase, leading to degradation of heparan sulfate in the basement membrane and increased growth factor interaction between epidermis and dermis. These changes may facilitate photo-aging.