Gelatinase expression at positive patch test reactions

Disclosing the involvement of proteases in an eczema murine animal model: Perspectives for protease inhibitor-based therapies

Eczema is a skin condition characterized by itchy and inflammatory patches. The accumulation of neutrophils and the imbalance between enzymes and their inhibitors appears to be related to this condition. We proposed a neutrophil elastase (NE)-based eczema model in mice in order to verify histopathological features as well as the expression and activity of proteases and inhibitors. Mice skins were topically administered with human NE (0-2 pmol/cm²) for 24-168 h. It was observed thickening of epidermis, parakeratosis, spongiosis and leukocyte infiltration. Also, NE-treated skins presented high activity of epidermal kallikreins 5 and 7, and cathepsin B on synthetic substrates, and expression evaluated by RT-qPCR. The proteolytic activity was inhibited by soybean trypsin inhibitor, CA074 and Caesalpinia echinata kallikrein inhibitor (CeKI). The topic application of CeKI reversed eczema phenotype in NE-treated skins. Elafin expression was shown to be increased in NE-treated skins. These results suggest that the NE may trigger morphological and biochemical changes in skin similar to those observed in eczematous diseases. In addition to the establishment of this in vivo model, this work opens perspectives for the use of protease inhibitor-based drugs for the management of this skin condition.

Effects of metal nanoparticles on tight junction-associated proteins via HIF-1α/miR-29b/MMPs pathway in human epidermal keratinocytes

Background

The increasing use of metal nanoparticles in industry and biomedicine raises the risk for unintentional exposure. The ability of metal nanoparticles to penetrate the skin ranges from stopping at the stratum corneum to passing below the dermis and entering the systemic circulation. Despite the potential health risks associated with skin exposure to metal nanoparticles, the mechanisms underlying the toxicity of metal nanoparticles on skin keratinocytes remain unclear. In this study, we proposed that exposure of human epidermal keratinocytes (HaCaT) to metal nanoparticles, such as nickel nanoparticles, dysregulates tight-junction associated proteins by interacting with the HIF-1α/miR-29b/MMPs axis.

Methods

We performed dose-response and time-response studies in HaCaT cells to observe the effects of Nano-Ni or Nano-TiO₂ on the expression and activity of MMP-2 and MMP-9, and on the expression of tight junction-associated proteins, TIMP-1, TIMP-2, miR-29b, and HIF-1α. In the dose-response studies, cells were exposed to 0, 10, or 20 μg/mL of Nano-Ni or Nano-TiO₂ for 24 h. In the time-response studies, cells were exposed to 20 μg/mL of Nano-Ni for 12, 24, 48, or 72 h. After treatment, cells were collected to either assess the expression of mRNAs and miR-29b by real-time PCR or to determine the expression of tight junction-associated proteins and HIF-1α nuclear accumulation by Western blot and/or immunofluorescent staining; the conditioned media were collected to evaluate the MMP-2 and MMP-9 activities by gelatin zymography assay. To further investigate the mechanisms underlying Nano-Ni-induced dysregulation of tight junction-associated proteins, we employed a HIF-1α inhibitor, CAY10585, to perturb HIF-1α accumulation in one experiment, and transfected a miR-29b-3p mimic into the HaCaT cells before Nano-Ni exposure in another experiment. Cells and conditioned media were collected, and the expression and activities of MMPs and the expression of tight junction-associated proteins were determined as described above.

Results

Exposure of HaCaT cells to Nano-Ni resulted in a dose-dependent increase in the expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 and the activities of MMP-2 and MMP-9. However, exposure of cells to Nano-TiO₂ did not cause these effects. Nano-Ni caused a dose-dependent decrease in the expression of miR-29b and tight junction-associated proteins, such as ZO-1, occludin, and claudin-1, while Nano-TiO₂ did not. Nano-Ni also caused a dose-dependent increase in HIF-1α nuclear accumulation. The time-response studies showed that Nano-Ni caused significantly increased expressions of MMP-2 at 24 h, MMP-9 at 12, 24, and 48 h, TIMP-1 from 24 to 72 h, and TIMP-2 from 12 to 72 h post-exposure. The expression of miR-29b and tight junction-associated proteins such as ZO-1, occludin, and claudin-1 decreased as early as 12 h post-exposure, and their levels declined gradually over time. Pretreatment of cells with a HIF-1α inhibitor, CAY10585, abolished Nano-Ni-induced miR-29b down-regulation and MMP-2/9 up-regulation. Introduction of a miR-29b-3p mimic into HaCaT cells by transfection before Nano-Ni exposure ameliorated Nano-Ni-induced increased expression and activity of MMP-2 and MMP-9 and restored Nano-Ni-induced down-regulation of tight junction-associated proteins.

Conclusion

Our study herein demonstrated that exposure of human epidermal keratinocytes to Nano-Ni caused increased HIF-1α nuclear accumulation and increased transcription and activity of MMP-2 and MMP-9 and down-regulation of miR-29b and tight junction-associated proteins. Nano-Ni-induced miR-29b down-regulation was through Nano-Ni-induced HIF-1α nuclear accumulation. Restoration of miR-29b level by miR-29b-3p mimic transfection abolished Nano-Ni-induced MMP-2 and MMP-9 activation and down-regulation of tight junction-associated proteins. In summary, our results demonstrated that Nano-Ni-induced dysregulation of tight junction-associated proteins in skin keratinocytes was via HIF-1α/miR-29b/MMPs pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00405-2.

House Dust Mites Induce Production of Endothelin-1 and Matrix Metalloproteinase-9 in Keratinocytes via Proteinase-Activated Receptor-2 Activation

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin barrier dysfunction and abnormal immune response. House dust mites (HDM) are a major source of allergens, some of which have cysteine and serine protease activities. Keratinocytes stimulated by HDM-derived proteases have been suggested to contribute to the pathogenesis of AD by producing various cytokines. However, whether keratinocytes contribute to the induction of pruritus in AD, especially by producing pruritus-related mediators upon stimulation with HDM-derived proteases, has not been fully elucidated.

METHODS

We examined whether the production of endothelin-1 (ET-1), matrix metalloproteinase (MMP)-2, and MMP-9 in keratinocytes can be induced by stimulation with Dermatophagoides farinae extracts, and if so, whether pretreatment with a protease inhibitor or proteinase-activated receptor-2 (PAR-2) antagonist affects the production of these mediators in keratinocytes.

RESULTS

Although MMP-2 levels were undetectable in the culture supernatants, the production of ET-1 and MMP-9 was increased upon stimulation with HDM extracts in a concentration- and time-dependent manner and suppressed by pretreatment of HDM extracts with serine protease inhibitor, but not with cysteine protease inhibitor. Mite-derived serine proteases also induced ET-1 and MMP-9 production in a concentration- and time-dependent manner. Moreover, pretreatment with a PAR-2 antagonist inhibited the production of ET-1 and MMP-9 in keratinocytes.

CONCLUSION

These results suggest that the activation of PAR-2 on keratinocytes by HDM-derived serine proteases induces the production of ET-1 and MMP-9, and may contribute to the induction of pruritus in AD.

Analysis of skin patch test results and metalloproteinase-2 levels in a patient with contact dermatitis

Introduction

The complex course of skin reactions that contact eczema involves is due in part to abnormalities of the extracellular matrix function. Proteins that degrade extracellular matrix components include metalloproteinases (MMP), which are divided into subcategories depending on the chemical structure and substrate specificity.

Aim

To analyse patch test results in contact dermatitis patients and to assess MMP-2 levels during skin lesion exacerbation and remission.

Material and methods

Fifty patients suffering from contact eczema were qualified to the study and 20 healthy volunteers as a control group. The study group patients had epidermal skin tests performed with the “European Standard” set. To assess the MMP-2 level in serum, venous blood was drawn, twice from study group patients – during contact dermatitis exacerbation and remission periods – and once from control group patients. Assessment of MMP-2 in serum was done with ELISA immunoassay. To verify the proposed hypotheses, parametric and nonparametric significance tests were used.

Results

Hands were the most frequent location of contact dermatitis. Nickel (II) sulphate was the most frequent sensitizing substance. Mean MMP-2 levels were statistically higher in the study group both in contact dermatitis exacerbation and remission periods than in the control group. There was no statistically significant difference between MMP-2 levels and skin patch test results.

Conclusions

Nickel is one of the most allergenic contact allergens in patients with contact dermatitis. Metalloproteinase-2 is a good marker of contact dermatitis in various stages of the disease.

Serum concentrations of metalloproteinase 2, metalloproteinase 9 and granzyme B in contact eczema patients

Introduction

Contact eczema is a common skin condition with complex etiology, variable clinical presentation and lengthy therapy duration. The mechanism of contact eczema is complex, since it is affected by multiple inflammatory mediators.

Aim

To assess concentrations of metalloproteinase 2 (MMP-2), metalloproteinase 9 (MMP-9) and granzyme B (GzmB) in patients with contact eczema.

Material and methods

Seventy patients with contact eczema and 30 healthy persons as controls were included in the study. In all subjects, MMP-2, MMP-9 and GzmB were determined using ELISA immunoassay. In study group patients, concentrations were assayed in periods of disease exacerbation and remission. Obtained results were analyzed statistically.

Results

Mean MMP-2 and GzmB concentrations were found to be significantly higher in the study group than in the control group. Mean MMP-2, MMP-9 and GzmB levels were also statistically significantly higher during skin lesion relapse compared to contact eczema remission periods.

Conclusions

The presented paper demonstrates that MMP-2, MMP-9 and GzmB are good markers of contact eczema exacerbations.

The effect of passive smoking on the levels of matrix metalloproteinase 9 in nasal secretions of children

BACKGROUND

Matrix metalloproteinase (MMP) 9 is a gelatinase associated with tissue remodeling. It is thought to play a part in the pathogenesis of allergy. Increased levels of MMP-9 have been shown to increase in the acute allergic response in the nose, lungs, and skin. Exposure to passive tobacco smoke is associated with an increase in sneezing, nasal blockage, and a decreased sense of smell. The aim of this study was to study the effect of passive smoking on the levels of MMP-9 in nasal secretions of children.

METHODS

A prospective descriptive study was performed. Thirty-nine children aged between 7 and 16 years were enrolled in the study. They were selected based on attendance at the Otorhinolaryngology Outpatients Clinic with a primary complaint unrelated to the nose or paranasal sinuses. Children with allergic rhinitis, sinusitis, or a recent cold were excluded. The study was performed at a tertiary pediatric referral center. Exposure to passive smoking was determined by measuring the urinary cotinine to creatinine ratio. Nasal fluid was obtained by using a Rhino-Probe curette (Arlington Scientific, Inc., Springville, UT). The concentration of MMP-9 was determined by ELISA. MMP-9 activity was determined by gelatin zymography. Data were tabulated on Microsoft Excel (Microsoft Corp., Redmond, WA) and analyzed using SPSS (SPSS Inc., Chicago, IL).

RESULTS

Using a cutoff urinary cotinine/creatinine ratio of 0.025 ng/mg, 15 children were found to be exposed to passive smoking. Both the MMP-9 concentration and the activity were significantly higher in nasal secretions of children exposed to passive smoking. There was a distinct difference between the two cohorts with regard to the level of enzyme activity per weight of protein. The lowest level of enzyme activity recorded in the "exposed" cohort was over twice that of the level in the "not exposed" cohort.

CONCLUSION

MMP-9 activity and concentration is higher in nasal secretions of children exposed to passive smoking. This suggests that passive smoking might alter the inflammatory response within the nasal mucosa in a similar way to allergy.

Development of atopic dermatitis-like skin disease from the chronic loss of epidermal caspase-8

Atopic dermatitis is an inflammatory skin disease that affects approximately 20% of children worldwide. Left untreated, the barrier function of the skin is compromised, increasing susceptibility to dehydration and infection. Despite its prevalence, its multifactorial nature has complicated the unraveling of its etiology. We found that chronic loss of epidermal caspase-8 recapitulates many aspects of atopic dermatitis, including a spongiotic phenotype whereby intercellular adhesion between epidermal keratinocytes is disrupted, adversely affecting tissue architecture and function. Although spongiosis is generally thought to be secondary to edema, we found that suppression of matrix metalloproteinase-2 activity is sufficient to abrogate this defect. p38 MAPK induces matrix metalloproteinase-2 expression to cleave E-cadherin, which mediates keratinocyte cohesion in the epidermis. Thus, the conditional loss of caspase-8, which we previously found to mimic a wound response, can be used to gain insights into how these same wound-healing processes are commandeered in inflammatory skin diseases.

Elevated levels of plasma matrix metalloproteinase-9 in patients with atopic dermatitis: a pilot study

Matrix metalloproteinase (MMP)-9 has been shown to play a role in the infiltration of inflammatory cells in various tissues. It is thus part of the pathogenesis of many inflammatory diseases, including asthma and allergic rhinitis/conjunctivitis. We compared plasma MMP-9 levels of 20 patients with atopic dermatitis (AD) with that of 17 control subjects. Additional outcome parameters consisted of the modified objective SCORing Atopic Dermatitis and the Three Item Severity score in patients, and peripheral blood leucocytes and eosinophils in both groups. Plasma MMP-9 levels were found to be significantly higher in patients compared with controls, supporting a role for MMP-9 in the pathogenesis of AD.

Tissue inhibitors of matrix metalloproteinase-1 levels are increased in serum of patients with allergic contact dermatitis

Allergic contact dermatitis (ACD) is an antigen-specific, T-cell-mediated skin inflammatory disease. Matrix metalloproteinases (MMPs) and their tissue inhibitors of matrix metalloproteinases (TIMPs) play a role in degradation of extracellular matrix and subsequent tissue remodelling during inflammatory process. The objective of this study was to examine a possible role of TIMP-1 and MMP-9 in the pathogenesis of ACD. The serum levels of MMP-9 and TIMP-1 have been measured using enzyme-linked immunosorbent assay in patients with disseminated ACD during exacerbation of skin lesions and the remission stage (n= 20) and were compared with healthy subjects (n= 20). The mean serum levels of TIMP-1 were significantly higher in patients with ACD than in control group (42.8 +/- 4.9 ng/ml). This difference was more prominent in patients with ACD during remission (69.01 +/- 6.99 ng/ml, P < 0.0001) than in patients with exacerbation of disease (46.8 +/- 3.6 ng/ml, P= 0.0054). Mean values of serum MMP-9 did not differ significantly between patients with ACD, both in the acute and in the remission stage, compared with healthy persons (P= 0.76 and P= 0.29, respectively). TIMP-1 might be involved in pathogenesis of ACD. It seems that moderately increased levels of TIMP-1 could reflect degree of activity of skin inflammation, whereas markedly increased levels could contribute to the maintenance of the remission of disease.

Analysis of the signal transduction pathway of nickel-induced matrix metalloproteinase-2 expression in the human keratinocytes in vitro: preliminary findings

BACKGROUND

Nickel can induce cellular and nuclear damages responsible for chronic diseases, like allergic contact dermatitis (ACD). We previously showed that matrix metalloproteinase-2 (MMP-2) gene expression was induced by nickel in nontumorigenic human keratinocytes cell line (HaCat).

OBJECTIVE

To investigate the signal transduction pathways involved in gelatinolytic activity induced in HaCat under nickel stimulation.

METHODS

We analyzed the involvement of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (PTK), nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) using specific inhibitors (H89, calphostin C, genistein, carpain and curcumin) by electrophoretic mobility shift assay, reverse transcription-polymerase chain reaction and gelatin zymography.

RESULTS

Our results indicate that nickel-induced MMP-2 production was inhibited with PTK, PKC and AP-1 specific inhibitors. Moreover, both PKA and NF-kB were not involved in nickel pathway.

CONCLUSIONS

Using HaCat, we showed that curcumin and genistein can revert nickel-induced MMP-2 upregulation. Whether the use of PTK and AP-1 inhibitors has therapeutic ramifications in the management of ACD remains to be investigated.

Modulation of keratinocyte-derived MMP-9 by IL-13: a possible role for the pathogenesis of epidermal inflammation

Skin inflammation and remodeling are important pathophysiological features of chronic eczematous skin diseases. Matrix metalloproteinases (MMP) have been described to influence tissue remodeling and to facilitate cell migration through their ability to proteolyse the extracellular matrix. The aim of this study was to investigate the influence of IL-13 on the modulation of MMPs in human primary keratinocytes (KCs). IL-13 stimulation of KCs induced the expression of MMP-9 but not of MMP-3 or MMP-2 at mRNA level. A major substrate of MMP-9 is the type IV collagen of the basement membrane. IL-13 induced the release of active MMP-9 in KCs as detected by an ELISA-based assay. Moreover, migration of lymphocytes cultured with IL-13-activated KC showed increased migration through a basement membrane equivalent. The MMP-9 expression was prominent near the basement membrane of IL-13-treated skin biopsies. Collagen type IV staining pointed to a loss of this major basement membrane constituent in IL-13-treated skin. Finally, we demonstrated the concomitant mRNA expression of MMP-9 and IL-13 in biopsies from lesional, acutely inflamed eczematous skin. Our results suggest that release of active MMP-9 by IL-13-stimulated KCs may play a crucial role in skin inflammation by facilitating migration of leukocytes into the epidermis.

Beneficial effects of tissue inhibitor of metalloproteinases-2 (TIMP-2) on chronic dermatitis

Chronic dermatitis, such as contact dermatitis (CD) or atopic dermatitis (AD), is a longstanding inflammatory skin disease with cutaneous damage such as erosion, ulceration, and lichenification due to itch-induced scratching. The resultant lesion can be considered to be a kind of wound. The tissue inhibitor metalloproteases-2 (TIMP-2) accelerates wound healing by enhancing the proliferation and migration of epidermal keratinocytes and dermal fibroblasts; it is also a physiologic inhibitor of matrix metalloproteinases. The aim of this study was to test the effect of TIMP-2 on chronic dermatitis. NC/Kuj mice were sensitized with Dermatophagoides farinae (Df) extract. Eczema was induced by repeated applications of this mite allergen to the skin of 20 sensitized mice that were maintained under specific pathogen-free conditions. One group of 10 mice was then treated with topical TIMP-2 solution (0.1 ml, 0.5%) for 28 days, and the other with vehicle alone and the effects of TIMP-2 were evaluated macro- and microscopically. The effect on skin barrier function was estimated by measuring transepidermal water loss (TEWL). Scoring of gross skin findings showed that TIMP-2 significantly reduced the severity of eczema (P<0.05) on days 12-28. Histological examination revealed that TIMP-2 treated mice manifested lower degrees of hyperkeratosis, acanthosis, and spongiosis in the epidermis and fewer inflammatory cells in the dermis than vehicle-treated mice. There were significant reductions in the epidermal thickness and dermal inflammatory cells in the TIMP-2 treated animals (P<0.01); their TEWL was significantly decreased on day 28 (P<0.05). Our results suggest that NC/Kuj mice with Df extract-induced chronic eczema may be a useful model for investigating chronic dermatitis, and that TIMP-2 may be a good agent for treating chronic dermatitis as well as chronic ulcers.

In vitro evaluation of matrix metalloproteinases as predictive testing for nickel, a model sensitizing agent

The identification of potential damage due to chemical exposure in the workplace is a major health and regulatory concern. Traditional tests that measure both sensitization and elicitation responses require the use of animals. An alternative to this widespread use of experimental animals could have a crucial impact on risk assessment, especially for the preliminary screening of new molecules. We developed an in vitro model for the screening of potential toxic compounds. Human keratinocytes (HaCat) were used as target cells while matrix metalloproteinases (MMP) were selected as responders because they are key enzymes involved in extracellular matrix (ECM) degradation in physiological and pathological conditions. Chemical exposure was performed using nickel sulphate as a positive tester. Nickel contact induced upregulation of MMP-2 and IL-8 mRNA production. Molecular activation occurred even at very low nickel concentrations even though no phenotypic changes were observed. MMP-9 accumulation was found in the medium of treated cells with respect to controls. These observations led to the hypothesis that even minimal exposure can accumulate transcriptional activity resulting in long-term clinical signs after contact. Our simple in vitro model can be applied as a useful preliminary complement to the animal studies to screen the effects of new potential toxic compounds.