Generation of three CRISPR/Cas9 edited human induced pluripotent stem cell lines (DHMi005-A-5, DHMi005-A-6 and DHMi005-A-7) carrying a Holt-Oram Syndrome patient-specific TBX5 mutation with known cardiac phenotype and a FLAG-tag after exon 9 of the TBX5 gene

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.

The importance of 12R-lipoxygenase and transglutaminase activities in the hydration-dependent ex vivo maturation of corneocyte envelopes

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.

A fundamental investigation into aspects of the physiology and biochemistry of the stratum corneum in subjects with sensitive skin

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.

Bladder cancer biomarker array to detect aberrant levels of proteins in urine

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.

Increased mass levels of certain serine proteases in the stratum corneum in acute eczematous atopic skin

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.

Increased stratum corneum serine protease activity in acute eczematous atopic skin

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.

Efficient and simple quantification of stratum corneum proteins on tape strippings by infrared densitometry

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.