Variation in the activities of late stage filaggrin processing enzymes, calpain-1 and bleomycin hydrolase, together with pyrrolidone carboxylic acid levels, corneocyte phenotypes and plasmin activities in non-sun-exposed and sun-exposed facial stratum corneum of different ethnicities

BACKGROUND: Knowledge of the ethnic differences and effects of photodamage on the relative amounts of natural moisturizing factor (NMF) together with filaggrin processing enzymes in facial stratum corneum is limited. Our aim was to characterize the activities of calpain-1 (C-1), bleomycin hydrolase (BH) and the levels of pyrrolidone carboxylic acid (PCA) as a marker for total NMF levels and to relate them to plasmin activities and corneocyte maturation. METHODS: Enzyme activities, PCA levels and corneocyte maturation were determined from facial tape strippings of photoexposed cheek and photoprotected post-auricular areas (PA) of healthy Caucasian (C), Black African (BA) and albino African (AA) female subjects living in South Africa. RESULTS: PCA concentration levels were of the order AA > BA > C subjects, and the highest activities of BH were present in the AA subjects. BH activities were greater on the photoexposed sites for the BA and C subjects, but they were only numerically elevated in the AA subjects. Photoprotected sites had an increase in C-1 activity in pigmented groups (C and BA), whereas in the AA subjects, the opposite was measured. Plasmin activities were greater on the cheek compared with the PA site for the AA and C subjects, but the activity was low in the BA subjects. In both test sites, the AA, but not the BA and C subjects, had smaller, parakeratotic and less mature corneocytes. CONCLUSION: Variation in PCA levels has been found for different ethnic groups in this study (AA > BA > C subjects). The values in the AA subjects are surprising as one might expect that the lack of pigmentation, and thereby increased photodamage, might lead to lower levels. Increased BH, but not C-1 activity, was observed in the AA subjects indicating that BH is associated with PCA production to a greater extent. Surprisingly, corneocyte maturation is still impaired with elevated PCA levels in AA subjects. The higher levels of plasmin and BH activities on the cheeks, especially for AA and C subjects, suggest that they can be used as markers for epidermal photodamage

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 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: 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 ≤ 0.03). 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

The Presence of Essential and Non-Essential Stratum Corneum Proteases: The Vital Need for Protease Inhibitors

Dry skin is one of the most important concerns of consumers worldwide. Despite huge efforts over several decades, the personal care industry still does not offer complete solutions that satisfy the unmet needs of consumers for moisturizing treatments. The paucity of data for the underlying biochemical problems in and the effects of moisturizers on facial skin biology and physiology may partly explain this. Our recent color mapping studies based on bio-instrumental evaluations of skin capacitance and transepidermal water loss have revealed the complexity of facial skin. However, the biomolecular reasons for these subtle differences in the different zones of the face are unknown so far. As the maturation of the stratum corneum is vital for skin moisturization and optimal barrier function, we believe that the protease / proteaseinhibitor balance particularly of the plasminogen system may be key in these processes. Thus, our aim was to develop a specific dual plasmin and urokinase inhibitor for topical application to barrier-impaired skin and demonstrate its efficac

On the Deformation of a Hyperelastic Tube Due to Steady Viscous Flow Within

In this chapter, we analyze the steady-state microscale fluid--structure interaction (FSI) between a generalized Newtonian fluid and a hyperelastic tube. Physiological flows, especially in hemodynamics, serve as primary examples of such FSI phenomena. The small scale of the physical system renders the flow field, under the power-law rheological model, amenable to a closed-form solution using the lubrication approximation. On the other hand, negligible shear stresses on the walls of a long vessel allow the structure to be treated as a pressure vessel. The constitutive equation for the microtube is prescribed via the strain energy functional for an incompressible, isotropic Mooney--Rivlin material. We employ both the thin- and thick-walled formulations of the pressure vessel theory, and derive the static relation between the pressure load and the deformation of the structure. We harness the latter to determine the flow rate--pressure drop relationship for non-Newtonian flow in thin- and thick-walled soft hyperelastic microtubes. Through illustrative examples, we discuss how a hyperelastic tube supports the same pressure load as a linearly elastic tube with smaller deformation, thus requiring a higher pressure drop across itself to maintain a fixed flow rate.Comment: 19 pages, 3 figures, Springer book class; v2: minor revisions, final form of invited contribution to the Springer volume entitled "Dynamical Processes in Generalized Continua and Structures" (in honour of Academician D.I. Indeitsev), eds. H. Altenbach, A. Belyaev, V. A. Eremeyev, A. Krivtsov and A. V. Porubo

Mutually exclusive sense–antisense transcription at FLC facilitates environmentally induced gene repression

Antisense transcription through genic regions is pervasive in most genomes; however, its functional significance is still unclear. We are studying the role of antisense transcripts (COOLAIR) in the cold-induced, epigenetic silencing of Arabidopsis FLOWERING LOCUS C (FLC), a regulator of the transition to reproduction. Here we use single-molecule RNA FISH to address the mechanistic relationship of FLC and COOLAIR transcription at the cellular level. We demonstrate that while sense and antisense transcripts can co-occur in the same cell they are mutually exclusive at individual loci. Cold strongly upregulates COOLAIR transcription in an increased number of cells and through the mutually exclusive relationship facilitates shutdown of sense FLC transcription in cis. COOLAIR transcripts form dense clouds at each locus, acting to influence FLC transcription through changed H3K36me3 dynamics. These results may have general implications for other loci showing both sense and antisense transcription

Spo0A∼P Imposes a Temporal Gate for the Bimodal Expression of Competence in Bacillus subtilis

ComK transcriptionally controls competence for the uptake of transforming DNA in Bacillus subtilis. Only 10%–20% of the cells in a clonal population are randomly selected for competence. Because ComK activates its own promoter, cells exceeding a threshold amount of ComK trigger a positive feedback loop, transitioning to the competence ON state. The transition rate increases to a maximum during the approach to stationary phase and then decreases, with most cells remaining OFF. The average basal rate of comK transcription increases transiently, defining a window of opportunity for transitions and accounting for the heterogeneity of competent populations. We show that as the concentration of the response regulator Spo0A∼P increases during the entry to stationary phase it first induces comK promoter activity and then represses it by direct binding. Spo0A∼P activates by antagonizing the repressor, Rok. This amplifies an inherent increase in basal level comK promoter activity that takes place during the approach to stationary phase and is a general feature of core promoters, serving to couple the probability of competence transitions to growth rate. Competence transitions are thus regulated by growth rate and temporally controlled by the complex mechanisms that govern the formation of Spo0A∼P. On the level of individual cells, the fate-determining noise for competence is intrinsic to the comK promoter. This overall mechanism has been stochastically simulated and shown to be plausible. Thus, a deterministic mechanism modulates an inherently stochastic process

Heat shock proteins in chronic kidney disease

Heat shock proteins (HSP) form a heterogenous, evolutionarily conserved group of molecules with high sequence homology. They mainly act as intracellular chaperones, protecting the protein structure and folding under stress conditions. The extracellular HSP, released in the course of damage or necrosis, play a pivotal role in the innate and adaptive immune responses. They also take part in many pathological processes. The aim of this review is to update the recent developments in the field of HSP in chronic kidney disease (CKD), in regard to three different aspects. The first is the assessment of the role of HSP, either positive or deleterious, in the pathogenesis of CKD and the possibilities to influence its progression. The second is the impact of dialysis, being a potentially modifiable stressor, on HSP and the attempt to assess the value of these proteins as the biocompatibility markers. The last area is that of kidney transplantation and the potential role of HSP in the induction of the immune tolerance in kidney recipients

E. coli metabolic protein aldehydealcohol dehydrogenase-E binds to the ribosome: a unique moonlighting action revealed

It is becoming increasingly evident that a high degree of regulation is involved in the protein synthesis machinery entailing more interacting regulatory factors. A multitude of proteins have been identified recently which show regulatory function upon binding to the ribosome. Here, we identify tight association of a metabolic protein aldehyde-alcohol dehydrogenase E (AdhE) with the E. coli 70S ribosome isolated from cell extract under low salt wash conditions. Cryo-EM reconstruction of the ribosome sample allows us to localize its position on the head of the small subunit, near the mRNA entrance. Our study demonstrates substantial RNA unwinding activity of AdhE which can account for the ability of ribosome to translate through downstream of at least certain mRNA helices. Thus far, in E. coli, no ribosome-associated factor has been identified that shows downstream mRNA helicase activity. Additionally, the cryo-EM map reveals interaction of another extracellular protein, outer membrane protein C (OmpC), with the ribosome at the peripheral solvent side of the 50S subunit. Our result also provides important insight into plausible functional role of OmpC upon ribosome binding. Visualization of the ribosome purified directly from the cell lysate unveils for the first time interactions of additional regulatory proteins with the ribosom

Decrease in thyroid adenoma associated (THADA) expression is a marker of dedifferentiation of thyroid tissue

<p>Abstract</p> <p>Background</p> <p><it>Thyroid adenoma associated (THADA) </it>has been identified as the target gene affected by chromosome 2p21 translocations in thyroid adenomas, but the role of THADA in the thyroid is still elusive. The aim of this study was to quantify <it>THADA </it>gene expression in normal tissues and in thyroid hyper- and neoplasias, using real-time PCR.</p> <p>Methods</p> <p>For the analysis <it>THADA </it>and 18S rRNA gene expression assays were performed on 34 normal tissue samples, including thyroid, salivary gland, heart, endometrium, myometrium, lung, blood, and adipose tissue as well as on 85 thyroid hyper- and neoplasias, including three adenomas with a 2p21 translocation. In addition, <it>NIS </it>(<it>sodium-iodide symporter</it>) gene expression was measured on 34 of the pathological thyroid samples.</p> <p>Results</p> <p>Results illustrated that <it>THADA </it>expression in normal thyroid tissue was significantly higher (<it>p </it>< 0.0001, exact Wilcoxon test) than in the other tissues. Significant differences were also found between non-malignant pathological thyroid samples (goiters and adenomas) and malignant tumors (<it>p </it>< 0.001, Wilcoxon test, t approximation), anaplastic carcinomas (ATCs) and all other samples and also between ATCs and all other malignant tumors (<it>p </it>< 0.05, Wilcoxon test, t approximation). Furthermore, in thyroid tumors <it>THADA </it>mRNA expression was found to be inversely correlated with <it>HMGA2 </it>mRNA. <it>HMGA2 </it>expression was recently identified as a marker revealing malignant transformation of thyroid follicular tumors. A correlation between <it>THADA </it>and <it>NIS </it>has also been found in thyroid normal tissue and malignant tumors.</p> <p>Conclusions</p> <p>The results suggest <it>THADA </it>being a marker of dedifferentiation of thyroid tissue.</p