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1.
Stem Cell Res ; 69: 103123, 2023 06.
Article in English | MEDLINE | ID: mdl-37210946

ABSTRACT

TBX5 is a transcription factor (TF) playing essential role during cardiogenesis. It is well known that TF mutations possibly result in non- or additional binding of the DNA due to conformational changes of the protein. We introduced a Holt-Oram Syndrome (HOS) patient-specific TBX5 mutation c.920_C > A heterozygously in a healthy induced pluripotent stell cell (iPSC) line. This TBX5 mutation results in conformational changes of the protein and displayed ventricular septal defects in the patient itself. Additionally we introduced a FLAG-tag on the TBX5 mutation-carrying allele. The resulting heterozygous TBX5-FLAG iPSC lines are a powerful tool to investigate altered TF activity bonding.


Subject(s)
Induced Pluripotent Stem Cells , Humans , Induced Pluripotent Stem Cells/metabolism , CRISPR-Cas Systems , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , Mutation/genetics , Transcription Factors/genetics , Transcription Factors/metabolism , Phenotype , Exons/genetics
2.
Stem Cell Res ; 66: 103011, 2023 02.
Article in English | MEDLINE | ID: mdl-36610218

ABSTRACT

Although TBX5 plays a major role during human cardiogenesis and initiates and controls limb development, many of its interactions with genomic DNA and the resulting biological consequences are not well known. Existing anti-TBX5-antibodies work very inefficiently in certain applications such as ChIP-Seq analysis. To circumvent this drawback, we introduced a FLAG-tag sequence into the TBX5 locus at the end of exon 9 prior to the stop codon by CRISPR/Cas9. The expressed TBX5-FLAG fusion protein can effectively be precipitated by anti-FLAG antibodies. Therefore, these gene-edited iPSC lines represent powerful cellular in vitro tools to unravel TBX5:DNA interactions in detail.


Subject(s)
CRISPR-Cas Systems , Induced Pluripotent Stem Cells , Humans , CRISPR-Cas Systems/genetics , Induced Pluripotent Stem Cells/metabolism , Exons/genetics
3.
Stem Cell Res ; 59: 102662, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35033855

ABSTRACT

We generated an induced pluripotent stem cell (iPSC) line from a healthy male 29-year-old proband. Adipose fibroblasts (AFs) were reprogrammed using Sendai virus. Generated iPSCs showed typical stem cell morphology. From passage 9 on, iPSCs were free of virus. Pluripotency in the iPSCs was verified and spontaneous differentiation showed expression of all three germ layers. Karyotyping indicated no anomalies for the generated iPSCs. Many patient-specific iPSCs are generated from subcutaneous fat fibroblasts obtained during surgical procedure. The described control iPSC line was generated equally and therefore serves as an ideal control for adipose-fibroblast-based patient-specific iPSC lines in disease modeling.

4.
Stem Cell Res ; 58: 102617, 2022 01.
Article in English | MEDLINE | ID: mdl-34894535

ABSTRACT

The Holt-Oram syndrome (HOS) is a rare autosomal dominant disorder, mostly based on mutations in the TBX5 gene. Patients show malformation of at least one upper limb along with congenital heart defects. The established induced pluripotent stem cell (iPSC) line was generated from a patient displaying pronounced and typical features of HOS and carrying a single-nucleotide change c.920_C>A leading to an amino acid change from proline to threonine at amino acid position 85, which appeared de novo. Adipose fibroblasts from the patient were reprogrammed using Sendai virus. Pluripotency of the iPSCs was fully demonstrated.


Subject(s)
Induced Pluripotent Stem Cells , T-Box Domain Proteins/genetics , Abnormalities, Multiple , Amino Acids/genetics , Heart Defects, Congenital , Heart Septal Defects, Atrial , Humans , Lower Extremity Deformities, Congenital , Male , Mutation/genetics , Upper Extremity Deformities, Congenital
5.
Int J Cosmet Sci ; 41(6): 563-578, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31429091

ABSTRACT

BACKGROUND: Terminally differentiated keratinocytes acquire corneocyte protein envelopes (CPE) complexed with corneocyte lipid envelopes (CLE). These two structural components of the corneocyte envelopes (CEs) undergo maturation by gaining in hydrophobicity, rigidity and surface area. Linoleoyl acylceramides are processed by 12R-lipoxygenase (12R-LOX) and other enzymes before transglutaminase (TG) attaches ω-hydroxyceramides to involucrin in the CPE. Concurrently, structural proteins are cross-linked by TG that has been activated by cathepsin D (CathD). OBJECTIVES: The primary aim of this work was to demonstrate the impact of relative humidity (RH) during ex vivo CE maturation. Low, optimal and high RH were selected to investigate the effect of protease inhibitors (PIs) on CE maturation and TG activity; in addition, 12R-LOX and CathD activity were measured at optimal RH. Finally, the effect of glycerol on ex vivo CE maturation was tested at low, optimal and high RH. METHODS: The first and ninth tape strip of photo-exposed (PE) cheek and photo-protected (PP) post-auricular sites of healthy volunteers were selected. Ex vivo CE maturation was assessed via the relative CE maturity (RCEM) approach based on CE rigidity and hydrophobicity. The second and eighth tapes were exposed to RH in the presence of inhibitors. RESULTS: Irrespective of tape stripping depth, CEs from PE samples attained CE rigidity to the same extent as mature CEs from the PP site, but such improvement was lacking for CE hydrophobicity. 70% RH was optimal for ex vivo CE maturation. The inhibition of 12R-LOX activity resulted in enhanced CE rigidity which was reduced by the TG inhibitor. CE hydrophobicity remained unchanged during ex vivo maturation in the presence of TG or 12R-LOX inhibition. CE hydrophobicity was enhanced in the presence of glycerol at 44% RH and 100% RH but not at 70% RH. Furthermore, TG activity was significantly diminished at 100% RH compared to the commercial inhibitor LDN-27219. However, a protease inhibitor mix reversed the negative effect of overhydration. CONCLUSION: The study adds to the understanding of the roles of 12R-LOX and TG activity in CE maturation and gives further insight into the effect of glycerol on the SC.


CONTEXTE: Les kératinocytes à différenciation terminale acquièrent les enveloppes protéiniques des cornéocytes (ECP) complexées aux enveloppes lipidiques des cornéocytes (ELC). Ces deux composants structurels des enveloppes cornéocytaires (EC) subissent un processus de maturation en gagnant en hydrophobicité, en rigidité et en surface. Les linoléoyl-acyle-céramides sont traités par 12R-lipoxygénase (12R-LOX) et d'autres enzymes avant que la transglutaminase (TG) ne fixe les x-hydroxy-céramides à l'involucrine dans les ECP. Les protéines structurelles sont simultanément réticulées par la TG qui a été activée par la cathepsine D (CathD). OBJECTIFS: L'objectif principal de ces travaux visait à démontrer l'impact de l'humidité relative (HR) pendant la maturation de l'EC ex vivo. Des humidités relatives faible, optimale et élevée ont été retenues pour étudier l'effet des inhibiteurs de la protéase (IP) sur la maturation de l'EC et l'activité de la TG ; l'activité de CathD et 12R-LOX a également été mesurée à une HR optimale. Finalement, l'effet du glycérol sur la maturation de l'EC ex vivo a été testé à des humidités relatives faible, optimale et élevée. MÉTHODES: La première et neuvième bandes adhésives sur un site à l'arrière de l'oreille protégé de la lumière (photo-protégé, PP) et sur une joue exposée à la lumière (photo-exposée, PE) de volontaires sains ont été sélectionnées. La maturation de l'EC ex vivo a été évaluée par l'approche de la maturité relative d'EC (RCEM) reposant sur l'hydrophobicité et la rigidité de l'EC. Les deuxième et huitième bandes ont été exposées à l'humidité relative en présence d'inhibiteurs. RÉSULTATS: Indépendamment de la profondeur de bande adhésive, les EC des échantillons EP ont atteint la rigidité d'EC de la même manière que les EC matures du site PP, mais ces améliorations faisaient défaut en ce qui concerne l'hydrophobicité des EC. Une HR à 70 % était optimale pour la maturation de l'EC ex vivo. L'inhibition de l'activité du 12R-LOX a entraîné une rigidité accrue de l'EC, laquelle était réduite par l'inhibiteur de la TG. L'hydrophobicité des EC est restée inchangée pendant la maturation ex vivo en présence de l'inhibition de la TG ou du 12R-LOX. L'hydrophobicité des EC a été améliorée en présence de glycérol à une HR de 44 % et à une HR de 100 %, mais non à une HR de 70 %. L'activité de la TG a par ailleurs significativement diminué à une HR de 100 % par rapport à l'inhibiteur commercial LDN-27219. Cependant, un mélange inhibiteur de la protéase a inversé l'effet négatif de la surhydratation. CONCLUSION: L'étude renforce la compréhension des rôles de l'activité de la TG et du 12R-LOX dans la maturation de l'EC et donne de plus amples détails sur l'effet du glycérol sur la couche cornée (stratum corneum, SC).


Subject(s)
Arachidonate 12-Lipoxygenase/metabolism , Skin/metabolism , Transglutaminases/metabolism , Adult , Female , Humans , Male , Skin/cytology , Young Adult
6.
Australas Phys Eng Sci Med ; 42(2): 611-617, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30868479

ABSTRACT

Following cardiac surgical procedures, multiple drainage systems remain in place inside the patient's chest to prevent the development of pericardial effusion or pneumothorax. Therefore, postoperative bleeding must be diligently observed. Currently, observation of the exudate rate is performed through periodical visual inspection of the reservoir. To improve postoperative monitoring, a measurement system based on load cells was developed to automatically detect bleeding rates. A reservoir retaining bracket was instrumented with a load cell. The signal was digitized by a microcontroller and then processed and displayed on customized software written in LabView. In cases where bleeding rates reach critical levels, the device will automatically sound an alarm. Additionally, the bleeding rate is displayed on the screen with the status of the alarm, as well as the fluid level of the reservoir. These data are all logged to a file. The measurement system has been validated for gain stability and drift, as well as for sensor accuracy, with different in vitro examinations. Additionally, performance of the measurement device was tested in a clinical pilot study on patients recovering from cardiac surgical procedures. The in vitro investigation showed that the monitoring device had excellent gain and drift stability, as well as sensor accuracy, with a resolution of 2.6 mL/h for the bleeding rate. During the clinical examination, bleeding rates of all patients were correctly measured. Continuously recording drainage volume using the developed system was comparable to manual measurements performed every 30 min by a nurse. Implementation of continuous digital measurements could improve patient safety and reduce the workload of medical professionals working in intensive care units.


Subject(s)
Monitoring, Physiologic/methods , Vascular Access Devices , Blood Loss, Surgical , Humans , Postoperative Period , Reproducibility of Results
7.
Int J Cosmet Sci ; 39(1): 2-10, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27079667

ABSTRACT

BACKGROUND: Sensitive skin is a poorly understood skin condition. Defects in stratum corneum (SC) barrier function and/or extrasensory neuronal networks in the epidermis are believed to be involved in the problem. OBJECTIVES: This study aimed to unravel the relationships between bleomycin hydrolase (BH) and calpain-1 (C-1), pyrrolidone carboxylic acid (PCA) levels, corneocyte maturation, transglutaminase (TG) and plasmin activities on the cheeks of subjects with sensitive skin. METHODS: Forty-eight female Caucasian subjects, Fitzpatrick skin phototypes II-III, with self-perceived sensitive facial skin, were assessed and underwent a capsaicin reactivity test. Expert grading of skin condition was conducted as well as the measurement of transepidermal water loss (TEWL), skin capacitance, SC cohesion and SC integrity. BH, C-1 and plasmin activities were measured as well as PCA levels, plasmin and TG activity. Differential Nile red and involucrin immunostaining was performed to assess corneocyte maturation and size. RESULTS: About 52% of the subjects reacted to capsaicin. There were no significant differences between the capsaicin-sensitive and non-capsaicin-sensitive subjects with reference to skin grading, TEWL, skin capacitance and SC cohesion. PCA levels and BH activity were lowest in the capsaicin-sensitive panel (P < 0.05) and were correlated in non-capsaicin-sensitive subjects (r = 0.72). The activity of TG was significantly lower (48%) in the capsaicin-sensitive subjects (P < 0.001) and their corneocytes were less mature and smaller (P ≤ 0.05). SC was estimated to be thinner (6.87 ± 0.28 vs. 8.68 ± 0.26 µm; P = 0.001) in the capsaicin-sensitive subjects with a corresponding shorter SC path length (83.2 ± 4.4 µm and 113.1 ± 4.5 µm; P = 0.001). CONCLUSIONS: Despite the physiological similarities between the two groups of sensitive skin subjects, differences in their biochemistry were clearly evident. Lower levels of PCA, BH and TG activities together with a greater number of smaller and immature corneocytes indicate inferior SC maturation in the capsaicin-sensitive subjects. The reduced maturation of corneocytes and thinner SC likely contributes to a greater penetration of capsaicin and the associated increased skin sensitivity.


Subject(s)
Sensory Thresholds , Skin Physiological Phenomena , Adult , Capsaicin/administration & dosage , Female , Humans , Middle Aged , Pyrrolidonecarboxylic Acid/metabolism
8.
Analyst ; 140(3): 724-35, 2015 Feb 07.
Article in English | MEDLINE | ID: mdl-25427191

ABSTRACT

Bladder cancer (BCa) is a serious malignancy of the urinary tract worldwide and also prominent for its high rate of recurrence incorporating 50% of all treated patients. To reduce relapse of BCa, lifelong surveillance of patients is essential leading to high treatment costs. The gold standard for the diagnosis of bladder cancer is cystoscopy. It is very sensitive, but due to high costs and its invasive nature this method for routine diagnosis of bladder cancer remains questionable. Because of this and the required surveillance of patients suffering from bladder cancer, urine based markers represent a new potential field of investigation. Literature at the National Center of Biological Information (NCBI) was retrieved for a potential marker panel offering specific protein signatures and used to develop a sensitive and accurate chip assay to monitor BCa. Discovery of possible bladder cancer protein markers is compiled by extensive literature search including 1077 recently (15.01.2008-20.03.2014) published research articles. Validation of this literature is done by selection based on prior defined inclusion and exclusion criteria. A set of six putative biomarkers (VEGF, IL-8, MMP-9, MMP-7, survivin and Cyfra 21.1) was identified and a non-invasive microarray developed to be used for further clinical validation. Investigation regarding optimized urine preparation and assay development, to enhance assay sensitivity for the marker panel, was carried out. This protein based BCa chip enables the fast (within 5 h), simultaneous, easy to operate, cheap, early and non-invasive determination of BCa and is ready for clinical evaluation.


Subject(s)
Biomarkers, Tumor/urine , Protein Array Analysis/methods , Urinalysis/methods , Urinary Bladder Neoplasms/diagnosis , Urinary Bladder Neoplasms/urine , Humans
9.
Int J Cosmet Sci ; 33(6): 560-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21699549

ABSTRACT

Acute eczematous atopic dermatitis (AD) is associated with increases in stratum corneum (SC) serine protease activity. The purpose of this study was to examine whether the increased SC protease activities in acute eczematous atopic dermatitis were associated with increased mass levels of SC proteases. Six subjects with healthy skin and six patients with AD each with non-lesional skin or lesional acute eczematous skin had the mass levels of their extractable SC kallikreins (KLK), plasmin and urokinase quantified using Luminex multiplex bead-based assays from SC tape strippings. The mass levels of KLK5 and KLK14 together with urokinase were not elevated in the SC in atopic skin. However, the mass levels of KLK7 and KLK11 together with plasmin were greatly elevated compared with the extracts from the non-lesional and the healthy skin and correlated with the corresponding enzymatic activities.


Subject(s)
Dermatitis, Atopic/enzymology , Fibrinolysin/metabolism , Kallikreins/metabolism , Urokinase-Type Plasminogen Activator/metabolism , Adult , Humans , Immunoenzyme Techniques , Young Adult
10.
Br J Dermatol ; 161(1): 70-7, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19416247

ABSTRACT

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory disease associated with changes in stratum corneum (SC) structure and function. The breakdown of epidermal barrier function in AD is associated with changes in corneocyte size and maturation, desquamation, lipid profiles, and some protease activities. OBJECTIVES: The purpose of this study was: (i) to examine physiological changes in lesional (L) skin of acute eczematous AD, compared with nonlesional (NL) AD skin and healthy (H) skin, using sequential tewametry and SC protein analysis to estimate SC thickness; and (ii) to assess which serine proteases might be involved in pathogenesis. METHODS: Six subjects with H skin, six AD patients with NL skin and six AD patients with mild to moderate eczema (L skin) were enrolled. Skin was assessed using several noninvasive techniques but SC thickness was estimated using tewametry and SC protein content of D-Squame strippings. SC integrity was determined by sequential tape stripping (D-Squame) and infrared densitometry. Kallikreins, plasmin, urokinase and leucocyte elastase protease activities together with a novel SC tryptase-like enzyme activity were quantified. RESULTS: Transepidermal water loss (TEWL) levels after D-Squame stripping were elevated in L compared with NL and H skin at all sampling points (P < 0.05). Conversely, the amount of SC removed by sequential tape stripping was decreased in L skin, indicating increased intracorneocyte cohesion (P < 0.05). By correlating 1/TEWL values and SC removed as an estimate of SC thickness, a significantly thinner SC was observed in L compared with NL and H skin (P < 0.05). Elevated extractable serine protease activity was measured in AD skin in the order: SC tryptase-like enzyme (45x), plasmin (30x), urokinase (7.1x), trypsin-like kallikreins (5.8x) and chymotrypsin-like kallikreins (3.9x). Leucocyte elastase activity was not detected in H and NL skin but was observed in AD SC samples (L skin). All enzymes were elevated in the deeper layers of L SC compared with NL and H SC samples. All consistently elevated SC protease activities were significantly correlated with the bioinstrumental data. CONCLUSIONS: We report increased serine protease activities in acute eczematous AD, especially in deeper layers of the SC, including SC tryptase-like enzyme, plasmin, urokinase and leucocyte elastase activities. These elevations in protease activities were associated with impaired barrier function, irritation, and reduced skin capacitance. Increased SC cohesion was apparent despite elevated TEWL during tape stripping, which would indicate reduced SC thickness in acute eczematous lesions of AD. Indeed, this was observed using an estimate of SC thickness.


Subject(s)
Dermatitis, Atopic/enzymology , Serine Endopeptidases/metabolism , Skin/enzymology , Acute Disease , Adult , Dermatitis, Atopic/physiopathology , Female , Humans , Kallikreins/metabolism , Male , Middle Aged , RNA, Messenger/analysis , Skin/pathology , Water Loss, Insensible/physiology , Young Adult
11.
Int J Cosmet Sci ; 30(6): 435-42, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19099544

ABSTRACT

There are indications of elevation of some inflammatory serine proteases in barrier damaged skin (e.g. plasmin and urokinase). Moreover, many other serine protease activities are present such as desquamatory enzymes as well as a newly detected tryptase-like serine protease. However, the activities of these proteases have never been correlated with stratum corneum (SC) barrier function. The activity of extractable key serine proteases (SC trypsin-like kallikreins, SC chymotrypsin-like kallikreins, SC tryptase-like serine protease, urokinase and plasmin) was measured from the outermost layers of SC obtained from facial tape strippings in clinically normal subjects. The protein content of the tape strippings was quantified by absorption measurements with the novel infrared densitometer SquameScan 850A and the protease activities by the use of fluorogenic peptide substrates. SC barrier function, SC hydration and skin surface pH were measured using AquaFlux, NOVA dermal phase meter and Skin-pH-Meter, respectively. As expected, SC hydration was reduced with increased transepidermal water loss (TEWL) values indicative of barrier impairment. Surprisingly, SC chymotrypsin-like activity showed no correlation with hydration or TEWL, whereas all other enzymes positively correlated with impaired barrier function and some were statistically significant: SC trypsin-like kallikreins (R(2 )=0.66, P < 0.01), SC tryptase-like enzyme (R(2 )=0.95, P < 0.001), plasmin (R(2 )=0.86, P < 0.001) and urokinase (R(2 )=0.50, P < 0.05). All enzymes except urokinase also negatively correlated with SC hydration. Elevated levels of SC serine proteases have been associated with some dermatological disorders, such as atopic dermatitis, psoriasis and rosacea but these results indicate that these enzymes are also elevated with milder forms of barrier disruption, which is not clinically evident as irritated skin. As these proteases are elevated in the SC, they will also be elevated in the epidermis where they can be involved in neurogenic inflammation and epidermal barrier impairment via activation of the protease-activated receptors. These results highlight the need for using serine protease inhibitors especially for urokinase and plasmin, SC tryptase-like serine protease and possibly SC trypsin-like kallikreins even in milder forms of barrier damage.


Subject(s)
Serine Endopeptidases/metabolism , Skin Physiological Phenomena , Skin/enzymology , Water Loss, Insensible/physiology , Adult , Female , Humans , Male , Middle Aged , Skin/metabolism , Spectrophotometry, Infrared
12.
Skin Res Technol ; 13(3): 242-51, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17610645

ABSTRACT

BACKGROUND: The analysis of stratum corneum (SC) components is a widely accepted method to determine 'skin health' status or to follow the effects of topical treatments. These analytes are normally corrected to the amount of SC removed which can be determined gravimetrically or by extraction of SC proteins and their subsequent analysis. Unfortunately, this is a time consuming procedure and usually requires a laboratory. As a result there is a need for equipment that can be used in a clinical setting. Equally, a concurrent determination of total SC protein content and enzyme activity or any other analyte on the same tape stripping is difficult and also time consuming. Therefore a compact infrared densitometer was developed allowing a convenient and user friendly indirect measurement of SC protein content on tape strippings by optical absorption. As this is a non-destructive technique, the tape strippings can subsequently be utilized for any other bioassay. METHODS: Using tape strippings from human subjects the SC optical absorption was determined densitometrically and after extraction of the tape strippings, their protein content was measured. A comparison between SC optical absorption and protein content was made between samples from different body sites, differing hydration and pH levels, different age groups and between the genders. RESULTS: The progression of absorption and protein curves was similar irrespective of tape strip number. The overall coefficient of determination (n=238) between absorption and protein content of forearm measurements was R(2)=0.852 and the corresponding overall linear regression 0.623x+2.703. Although the data distribution in the different subject groups varied, the regression was always quite similar and independent of gender, age, skin hydration rate, skin pH and varying skin areas. The correlations reached were statistically significant. CONCLUSION: Infrared densitometry is an easy to use and non-destructive technique for the convenient measurement of the optical absorption of SC tape strippings which was shown to be linearly proportional to their protein content. Thus the corresponding SC densitometric-protein content calibration curves can be used for a fast indirect protein evaluation of tape strippings. As this is a non-destructive method, the unmodified tapes can be used for further investigations.


Subject(s)
Densitometry/instrumentation , Epidermis/chemistry , Proteins/analysis , Spectrophotometry, Infrared/instrumentation , Adult , Densitometry/methods , Densitometry/standards , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Regression Analysis , Reproducibility of Results , Specimen Handling , Spectrophotometry, Infrared/methods , Spectrophotometry, Infrared/standards , Water/metabolism
13.
Int J Cosmet Sci ; 29(3): 191-200, 2007 Jun.
Article in English | MEDLINE | ID: mdl-18489349

ABSTRACT

Seasonal variation in stratum corneum (SC) biophysical and biological characteristics has been described previously. In particular, the winter season has been shown to affect more severely the properties of facial skin compared with forearm skin. Moreover, when compromised, such as in dry skin conditions, facial SC has been shown to contain increased inflammatory cytokines and proteases. Nevertheless, there have been no comparative studies of the activities and depth activity of several proteases in the SC on different body sites and at different times of the year. In this study, we examined the distribution of key serine protease activities (kallikrein 5, kallikrein 7, urokinase, plasmin and a tryptase-like enzyme) in different layers of the SC on the cheek and the forearm by analysis of consecutive tape strippings of healthy Caucasian subjects during winter and summer. The protein content of the tape strippings was quantified by absorption measurements with a recently developed and novel infrared densitometer SquameScan 850A while the SC enzyme activities were determined using fluorogenic peptide substrates. Transepidermal water loss (TEWL), skin pH and skin hydration were higher on the cheek than on the forearm. In the same way, the activity of the inflammatory-related proteases plasmin, urokinase and tryptase was approximately five to eight times and the activity of the desquamatory-related proteases kallikrein 5 and kallikrein 7 approximately two to four times higher on the cheek than on the forearm. There were no gender-related differences in these enzyme activities except for the increased kallikrein 7 in the forearm skin of the female subjects in winter. Reduced kallikrein 5 was associated with increased SC cohesion, as judged by increased protein removal, in forearm skin in the winter months of the year although the skin was clinically normal. It can be concluded that (i) protected skin areas show lower TEWL, skin pH and skin hydration and less protease activities than skin areas that are exposed to the environment, possibly indicating subclinical inflammation on these body sites, (ii) in normal healthy forearm skin, the outer SC exhibits greater serine protease activity than its deeper layers, (iii) compared with the forearm, urokinase- and plasmin-like activities are elevated on SC strippings from the cheek, confirming activation of the plasminogen cascade, and (iv) tryptase-like activity in the SC is also elevated in samples from the cheek, possibly indicating involvement of mast cells in these barrier-compromised body sites or the synthesis of a novel tryptase-like enzyme by keratinocytes. Although elevation of the activities of urokinase, plasmin, kallikrein 5, kallikrein 7 and now a tryptase-like enzyme was observed on SC derived from skin of clinically normal cheeks, we anticipate even higher activities in skin conditions where the epidermal barrier is further impaired.

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