Skin Thickness Research Articles

Camelina sativa (L.) Crantz straw and pomace as a green filler for integral skin polyurethane foam

The development of efficient methods for obtaining cellular materials with improved functional properties is a constant challenge for the plastics industry, including the polyurethane industry. In recent years, efforts have been made to obtain cheap and easily available raw materials that can be used as foam fillers. In addition to commercially used synthetic fillers, more and more attention is paid to materials of natural origin, in particular to agricultural and industrial waste. This solution not only meets the assumptions of the "Green Chemistry" concept but also creates the opportunity to improve the properties of plastics while reducing their production costs. This study focuses on the use of naturally derived materials as fillers in flexible integral polyurethane foams (Integral Skin Foams, ISFs) to produce economically advantageous and ecologically sustainable composite materials. Waste materials such as Camelina sativa (L.) Crantz straw and pomace were used as biofillers. The obtained samples were used to determine the processing parameters and functional properties of the foams: hardness, tensile strength, elongation at break and permanent deformation after compression. In the case of both straw and pomace, an increase in growth time and an increase in the free density of the foams were observed with an increase in the amount of added plant material. The analysis of morphology and chemical structure of the obtained composites led to the conclusion that the cellular structure, skin thickness, and functional groups present in biofillers had a direct impact on the functional properties of ISF. For most composites, a significant improvement in mechanical parameters was observed compared to the reference foam. The obtained results confirmed the utility potential of Camelina sativa (L.) Crantz straw and pomace. The main research assumption has been fully implemented that focused on obtaining innovative polyurethane composites with improved functional properties.

Compressive and Bending Properties of 3D-Printed Wood/PLA Composites with Re-Entrant Honeycomb Core

This study investigates the mechanical behavior of sandwich structures comprising a re-entrant honeycomb core structure created using wood/polylactic acid (PLA) filaments via fused deposition modeling (FDM) technology. The sandwich structures were manufactured with different face layer thicknesses (0 mm, 0.8 mm, and 1.6 mm) and various core topologies. Material characterizations included bending tests, compressive tests, and finite element analysis (FEA) to identify stress concentration areas. In-plane and out-of-plane re-entrant honeycomb core structure specimens were tested to examine the bending properties. In addition, flatwise and edgewise compressive tests were performed to investigate the structures' compressive properties. Furthermore, the modulus of elasticity for each specimen was determined using the finite element technique (FEM). The results reveal that increasing the thickness of the face layer significantly enhances the structure's resistance to bending forces. Furthermore, specimens with an in-plane orientation demonstrated better bending strength compared to those with an out-of-plane orientation due to increased material underloading. In flatwise compressive tests, specimens without a face layer exhibited the highest strength, attributed to their greater displacement. In contrast, edgewise compressive tests showed significant buckling behavior of the face sheet, the maximum stress increased proportionally with the thickness of the face layer, reaching its peak at a skin thickness of 1.6 mm. The findings are validated by ANSYS analysis, which closely mirrors the experimental results, providing insight into flexural modulus, modulus of elasticity, and stress concentration. These findings indicate that architected core structures could be efficiently utilized to improve bending/compressive characteristics and failure mechanisms, providing valuable insights into the mechanical response of sandwich structures for different industrial applications.

Enhancement of extraction efficiency and functional properties of chickpea protein isolate using pulsed electric field combined with ultrasound treatment

Chickpea protein isolate (CPI) is a promising dietary protein with the advantages of low allergenicity, easy digestion and balanced composition of essential amino acids. However, due to the thick skin of chickpeas, the extraction of CPI is challenging, resulting in lower efficiency of the alkaline extraction-isoelectric precipitation (AE-IEP) method. Therefore, the present study investigated the effect of pulsed electric field combined with ultrasound (PEF-US) treatment on the extraction efficiency of CPI and the functional properties was characterized. Parameter optimization was carried out using response surface methodology (RSM), with the following optimized conditions: pulse duration of 87 s, electric field intensity of 0.9 kV/cm, ultrasonic time of 15 min, and ultrasonic power of 325 W. Under the optimized conditions, the yield of CPI after combined (PEF-US) treatment was 13.52 ± 0.13 %, which was a 47.28 % improvement over the AE-IEP method. This yield was better than that obtained with either individual PEF or US treatment. Additionally, the functional properties (solubility, emulsification, and foaming) of CPI were significantly enhanced compared to AE-IEP. However, the stability of emulsification and foaming did not show significant differences among the four methods. The PEF-US method efficiently extracts CPI with excellent functional properties, enabling the production of proteins as desired functional additives in the food industry.

Evaluating Factors Affecting Mean Glandular Dose in Mammography: Insights from a Retrospective Study in Dubai

Background/Objective: This study evaluates the mean glandular dose (MGD) in mammography screening for women aged 40–69 in Dubai, based on a retrospective analysis of a dose survey involving 2599 participants. Methods: MGD was calculated using the Dance formula. Results: The average MGD was 0.96 ± 0.39 mGy for mediolateral oblique (MLO) views and 0.81 ± 0.33 mGy for craniocaudal (CC) views. Weak inverse correlations were found between age and organ dose (OD) for both views, while a direct relationship was observed between breast thickness and entrance skin dose (ESD). In adjusted models, ESD was strongly associated with MGD (β = 1.04, 95% CI: 0.97, 1.09), while OD showed a moderate association (β = 0.44, 95% CI: 0.40, 0.49). Significant variations in ESD, OD, and MGD were noted across age groups and breast thicknesses. Conclusions: Lower MGD indicates reduced radiation exposure risk, while higher MGD in MLO views suggests improved imaging quality. Monitoring and optimizing MGD are essential for enhancing patient safety and screening efficacy.

Skin aging and dermatoporosis-the chronic skin fragility syndrome

Skin aging is divided into intrinsic and extrinsic aging, encompassing pigmentary, vascular, connective tissue, and fat tissue aspects that contribute to this complex process. Aging is genetically determined but is influenced by environmental factors such as ultraviolet radiation, air pollution, and smoking. Skin aging has not only cosmetic but also functional implications, as the loss of the extracellular matrix, especially hyaluronate, impairs the mechanical functions of the skin. Hyaluronate, which stabilizes skin structures, acts as acushion and reduces susceptibility to skin tears. Dermatoporosis, aterm coined by Saurat, describes the functional dimension of skin aging, manifesting in various stages from skin atrophy to severe complications like skin necrosis. It is increasingly observed in older patients, particularly from age70 onwards. Prevalence ranges from 22% in women to 38% in men, with higher rates in patients undergoing chronic steroid therapy and certain conditions. Diagnosis is made through clinical examination and skin thickness measurement via ultrasound. Prevention involves limiting exposure to harmful factors and using specific treatments such as hyaluronic acid and topical retinoids to improve skin health.

Surgical Considerations in the Management of Constriction Ring Syndrome.

Surgical management of constriction ring syndrome (CRS) is individualised due to the heterogenic presentation of the condition. CRS includes constriction rings, acrosyndactyly, nubbins and short digits. Involvement of more than one limb is common and children often need multiple surgeries. Each limb may need staged surgeries. If the child has vascular or lymphatic compromise secondary to a constriction ring, the ring needs to be excised and released in the first few days of life. The rings are released using multiple big Z-plasties in one or two stages. Nerve palsy associated with the rings need early intervention. Tendon transfers may be advised when nerve procedures like neurolysis and nerve reconstruction fail. Acrosyndactyly can be corrected with separation of the fused fingertips. At times, the web is more distal than usual and requires web deepening using partial syndactyly separation techniques and may need full thickness skin grafting. Complex type of acrosyndactyly is difficult to treat as it needs proper planning and staged surgical correction to achieve a five-digit hand. Separation of the syndactyly with web deepening gives more functional length and independence to the digits. The short fingers, especially the thumb, need reconstruction. Non-vascularised toe phalangeal transfer or a microvascular toe transfer can reconstruct a missing digit. Level of Evidence: Level V (Therapeutic).

Design, Synthesis, and Biological Evaluation of New Selective PDE4 Inhibitors for Topical Treatment of Psoriasis.

Psoriasis is a complex and chronic inflammatory disease. Current drugs help control the symptoms of psoriasis but make no cure, urging discovery of novel drugs. We report in this paper the discovery of new phosphodiesterase 4 (PDE4) inhibitors for treatment of psoriasis. We designed and synthesized 45 new compounds, among which 14h exhibited IC50 of 0.57 nM for PDE4D and >4100-fold selectivity over other PDE families. Compound 14h inhibited release of inflammatory cytokines of TNF-α (IC50 = 34.2 μM) and IL-6 (IC50 = 40.9 μM) in Raw264.7 cells and reduced the expression of IL-1β and IL-17A in the skin of psoriasis mice. In addition, 14h alleviated IMQ-induced psoriasis in the mouse model and reduced the erythema level, scales, and thickness of the back skin of the mice. In short, our results suggested that PDE4 inhibitor 14h is a strong candidate for the topical treatment of psoriasis.

Various Cultivars of Citrus Fruits: Effects of Construction on Gas Diffusion Resistance and Internal Gas Concentration of Oxygen and Carbon Dioxide

Various cultivars of citrus fruits have unique constructions, such as thick outer skin. These constructions generate gas diffusion resistance between the atmosphere and the fruit, which can limit the gas exchange of O2 and CO2.This has not been sufficiently investigated. This study on seven cultivars of citrus fruit firstly aimed to investigate gas diffusion resistance utilizing the ethane efflux method; secondly, this study aimed to investigate the internal gas concentration of O2 and CO2. As a result, a cultivar of citrus fruit with slimmer outer skin thickness had lower resistance. For the internal gas, a high CO2 concentration in comparison with the atmosphere was observed even in the fruits with the minimum resistance, and no considerable difference was observed among all cultivars, regardless of the gas diffusion resistance value. However, when the fruits were stored at 25 °C for 2 weeks, CO2 gas concentration tended to increase and O2 gas concentration tended to decrease, with an increase in the resistance value. Therefore, when the respiration of citrus fruits is activated at ambient temperature, the self-control system of internal gas concentration can be driven to suppress the respiration which was induced by gas diffusion resistance generated from their construction.

A leadless power transfer and wireless telemetry solutions for an endovascular electrocorticography

Objective. Endovascular brain-computer interfaces (eBCIs) offer a minimally invasive way to connect the brain to external devices, merging neuroscience, engineering, and medical technology. Currently, solutions for endovascular electrocorticography (ECoG) include a stent in the brain with sensing electrodes, a chest implant to accommodate electronic components to provide power and data telemetry, and a long (tens of centimeters) cable travel through vessels with a set of wires in between. Removing this long cable is the key to the clinical viability of eBCIS as it carries risks and limitations, especially for patients with fragile vasculature.Approach. This work introduces a wireless and leadless telemetry and power transfer solution for ECoG. The proposed solution includes an optical telemetry module and a focused ultrasound (FUS) power transfer system. The proposed system can be miniaturised to fit in an endovascular stent, removing the need for long, intrusive cables.Main results. The optical telemetry achieves data transmission speeds of over 2 Mbit/s, capable of supporting 41 ECoG channels at a 2 kHz sampling rate with 24-bit resolution. The FUS power transfer system delivers up to 10 mW of power to the implant through the scalp(6 mm), skull(10 mm), and subdural space(5 mm), adhering to safety limits. Testing on bovine tissue (10 mm thick bone, 7 mm thick skin) confirmed the system's efficacy.Significance. This leadless and wireless solution eliminates the need for long cables and auxiliary implants, potentially reducing complications and enhancing the clinical applicability of eBCIs. The proposed system represents a step forward in enabling safer and more effective ECoG for a broader range of patients.

Dual blockade of IL-17A and IL-36 pathways via a bispecific antibody exhibits enhanced anti-inflammatory potency

Antibody drugs targeting single inflammatory cytokines have revolutionized the treatment of immune-mediated inflammatory diseases. To investigate whether dual targeting interleukin-17 (IL-17) and IL-36 enhances anti-inflammatory activity, bispecific Ab HB0043 was generated by linking the single chain fragment variables (scFvs) from humanized anti-IL-36R antibody (HB0034) to the C-terminus of the heavy chain of anti-IL-17A IgG1 (HB0017) Fc using a flexible peptide linker. HB0043 largely maintained the binding affinities and biological activities of the two parent monoclonal antibodies (mAbs) in vitro. IL-17 and IL-36 cooperated to amplify the expression of pro-inflammatory and pro-fibrotic genes in normal human dermal fibroblasts (NHDF). However, HB0043 more effectively blocked IL-6 and IL-8 production in NHDF stimulated by IL-17A and IL-36 compared to two monoclonal antibodies. In a mouse model of Oxazolone (OXA)-induced atopic dermatitis and Imiquimod (IMQ)-induced skin inflammation, administration of both anti-IL17A mAb HB0017 and anti-mouse IL-36R surrogate antibody HB0034SA showed improved effectiveness in alleviating skin thickening and inflammation based on histological assessment. Further, in cynomolgus monkeys, HB0043 showed no enhanced target-related toxicity compared with the two parental mAbs in vivo and with a moderate increase in production of anti-drug antibodies. Together, dual blockade of IL-17A and IL-36R in the form of a bispecific antibody may have advantages in blocking the overlapping and non-overlapping functions of these two cytokines in skin inflammation that could not optimally be curtailed with single mAbs. In conclusion, as monotherapy may reach therapeutic celling for certain difficult-to-treat inflammatory and fibrotic diseases, dual targeting could potentially pave a way to combat these diseases.

Larger than life: A case of a bleeding giant phyllodes tumor in a COVID-19 positive patient

Introduction: Phyllodes tumor of the breast, also known as cystosarcoma phyllodes, is a rare fibroepithelial tumor that accounts for about 0.3–1% of all breast tumors. Unlike most breast tumors that start from the ducts and gland, phyllodes tumor originates from the stroma. The classification of phyllodes tumor is less important on assessing the risk of recurrence as compared to the presence of tumor-free margins after surgical treatment. Case Report: A 54-year-old female presented at the emergency room with a large, bleeding, left breast mass. The patient tested positive for COVID-19 and was admitted previously at the isolation ward. After medical management of her current condition, the patient underwent wide excision (total mastectomy), left with en bloc resection of pectoralis major with delayed reconstruction via split thickness skin graft. This case is one of the few reported giant phyllodes tumor in the English literature, measuring 30 cm widest dimension. Conclusion: Malignant phyllodes tumor is a rare form of breast malignancy behaving like a sarcoma. A diagnostic dilemma may be encountered in patients with such tumors due to the rarity of these cases and the different presentation of the tumor. High suspicion shall be entertained for patients with breast masses which tend to appear like benign lesions but with sudden enlargement. Adequate surgical intervention shall be done ensuring tumor-free margins. Adjuvant therapy for malignant phyllodes tumor is still controversial but shall be entertained according to the patient’s actual case needs.

Niosomal gel improves dermal delivery of nimbolide: a promising approach for treatment of psoriasis.

Aim: Psoriasis is a chronic inflammatory skin disorder characterized by the excessive proliferation of keratinocytes, forming thickened skin plaques due to immune-mediated cytokine responses. Delivering drugs through this barrier to target inflamed tissues remains challenging. Nimbolide (NIM), known for its anti-inflammatory and anticancer properties, shows promise in managing psoriasis. However, its efficacy is limited by its inability to penetrate the thickened horny layer of the skin. To overcome this obstacle, we have developed Nim-loaded niosomal (Nio) formulations (NIM Nio) aimed at improving dermal delivery and achieving localized sustained release at psoriasis-affected sites.Methods: The formulation characteristics were assessed using Zeta sizer, Transmission Electron Microscopy (TEM), and High-performance liquid chromatography (HPLC). The optimized formulation was evaluated for anti-psoriatic potential compared to Nim alone by using molecular techniques such as Confocal Microscopy, Flow cytometry, enzyme-linked immunosorbent assay (ELISA), and Western blotting.Results: NIM Nio showed effective penetration into psoriatic skin, resulting in reductions in keratinocyte hyperproliferation, oxidative stress, splenomegaly, inflammatory cytokines, Psoriasis Area and Severity Index (PASI), and rete ridges compared to NIM alone.Conclusion: Our findings underscore the significant anti-proliferative, antioxidant, and anti-inflammatory properties of NIM Nio in psoriasis, demonstrating its potential as a promising therapeutic option for this challenging condition.

A classification system of Asian noses for rhinoplasty.

While Asian noses are generalised as having smaller bones and softer cartilages, thicker skin and soft tissue envelop (SSTE), there exists a diversity of morphology amongst Asian noses. The over-simplification of Asian noses diminishes the validity or generalizability of rhinoplasty research findings and makes comparison of outcomes challenging. A classification system is proposed that reflects the different structures and SSTEs of the nasal subtypes, the techniques required in the management of each of the subtypes, the challenges the surgeon will face intra- and post-operatively, allows for pre-operative counselling of expected outcomes and facilitate valid and fair comparison of study outcomes by comparing like for like. The classification system stratifies noses into four subtypes based on i. the size and strength of the nasal bone and cartilages, and ii. the thickness of the SSTE. Type I noses have thinner SSTE and stronger structure. Type II noses have thinner SSTE and weaker structure. Type III noses have thicker SSTE and stronger structure. Type IV noses have thicker SSTE and weaker structure. Inter-rater variability in classifying noses amongst rhinoplasty surgeons was found to be very high with a kappa coefficient of 0.933 (95% confidence interval 0.852 to 1.014; variance 0.013).

The Application of High-Frequency Ultrasonography in Post-Therapeutic Assessment of Actinic Keratosis After Photodynamic Therapy

Objectives: Actinic keratoses (AKs) are one of the most common reasons for consultation in the elderly population. This study aimed to assess the efficacy of 5-ALA PDT in AK treatment using high-frequency ultrasonography (HFUS) to evaluate skin layer changes during therapy. Methods: In our study, we included 44 AK patients aged 53 to 89 years. All patients had lesions clinically evaluated with the Olsen and AKASI scale. HFUS imaging was performed on seemingly healthy skin and lesions before and at 4, 8, and 12 weeks of therapy. Ultrasound markers such as skin thickness, echogenicity, and pixel intensity were measured. 5-ALA was applied under occlusion for 3 h. After removing the occlusive dressing, 5-ALA was removed with a saline solution and a directed therapy with a BF-200 lamp. Full follow-ups of 56 markers of suitable quality were selected. Results: The thickness of SLEB significantly decreased in the following weeks compared to the pre-therapy results, reaching its lowest values after 12 weeks. The average pixel intensity significantly increased in each skin layer after therapy (p < 0.01). For SLEB, there were statistically significant differences in LEP, MEP and contrast. The AKASI score before and after treatment was determined for the 39 patients who underwent follow-up at week 12. The median AKASI score was 3.2 (1.2–8.6) before treatment and 0.6 (0–2.8) after. Conclusions: According to the literature data, this is the first study describing the ALA-PDT treatment efficacy in different AK severities evaluated in HFUS. HFUS provides a valuable non-invasive tool for monitoring the efficacy of PDT in AK treatment, showing significant improvements in skin texture and structure.

Ethnic Rhinoplasty in the Brazilian Population: Current Concepts.

The large mixture of races in Brazil gives the nose its distinctive composition, which makes rhinoplasty difficult for these patients. Every patient should have their anatomy thoroughly examined on an individual basis, as there is no unique strategy that works for all situations. This is a narrative overview of the last 10 years' worth of literature that describes the ethnic traits of each nose, with a particular emphasis on the Brazilian nose, and talks about the major surgical approaches that can be applied in these situations. The low dorsum, broad nasal bones, thick skin, and bulbous tip are the primary features of the Brazilian nose. Many times, lateral osteotomies, root grafting, isotretinoin treatment for skin thickness, and neodomus formation are required. The Brazilian nose presents a surgical challenge that calls for the mastery of multiple procedures, not simply structured rhinoplasty. In certain cases, preservation rhinoplasty may even be used. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Systematic researches on the ground state properties of the medium-mass neutron-rich nuclei

Abstract The recently developed relativistic-mean-field in complex momentum representation with the functional NL3* was used to explore the exotic properties of neutron-rich Pd, Cd, Te, and Xe isotopes. The results were compared with those obtained using the relativistic Hartree-Bogoliubov (RHB) calculations, and available experimental data. The single-particle levels were obtained for the bound and resonant states. The two neutron separation energies S2n and root mean square (rms) radii, agree with the experimental data. It is shown that a halo structure in the extremely neutron-rich 164-180Te and 164-182Xe, as well as a thick neutron skin in the extremely neutron-rich Pd and Cd isotopes. From the numbers of neutrons (Nλ) and (N0 ) occupying the levels above the Fermi surface and the zero-potential energy level, it was found that pairing correlations play an important role in the formation of halo phenomena. These findings are further supported by investigating S2n, rms radii, occupation probabilities, contributions of single-particle levels to the neutron rms radii, and density distributions. The neutron rms radii increased sharply, obviously deviating from the traditional rule r ∝A1/3, and the density distributions were very diffuse. Finally, the contributions of different single-particle levels to the total neutron density and wavefunction were discussed. It was found that the sudden increase in the neutron rms radii and diffuse density distributions mainly come from the resonant levels with a lower orbital angular momentum near the continuum threshold.

Effect of skin thickness on electromagnetic dosimetry analysis of a human body model up to 100 GHz

Abstract The accuracy of electromagnetic (EM) exposure assessments depends mainly on the resolution of a voxel human body model. The resolution of the conventional human body model is limited to a few millimeters. In the millimeter wave (mmWave) frequency range, EM waves are absorbed by the superficial tissues in the human body. Therefore, resolution and skin thickness of the human body model are important for accuracy of the EM wave exposure metrics recommended by international human safety guidelines. Realistic thickness modeling of the skin tissue on the human body may provide greater accuracy in the EM exposure assessment, especially at mmWave frequency range. In this paper, effects of the skin thickness on the EM exposure metrics in one-dimensional multi-layered models obtained from different regions of the body model are investigated using the dispersive algorithm based on the finite-difference time-domain method over the frequency range from 1 to 100 GHz. Furthermore, effects of eyelid tissue in a human eye on the EM exposure metrics are studied over the frequency range. The EM exposure metrics such as absorbed power density, heating factor, and power transmission coefficient are calculated up to 100 GHz to evaluate the limits of EM wave exposure.

The Influence of Skin Microbial Ecology on γδ T Cell Immune Pathways in Allergic Dermatitis Models in Mice.

Atopic dermatitis (AD) is a complex disease influenced by alterations in the skin microbiome and immune dysregulation. Despite the recognized role of these factors, the specific pathways by which distinct microbial populations affect skin immunity remain insufficiently understood. On a molecular level, the pathogenesis of AD involves critical cytokines such as IL-4, IL-17, interferon-γ (IFN-γ), and IL-10, which contribute to the imbalance in T helper (Th) cell responses. Importantly, gamma-delta (γδ) T cells, which produce these cytokines and infiltrate affected epithelial cells in AD, have been underexplored. This study seeks to alleviate AD symptoms in mice by adjusting both peripheral and local immune environments through the transplantation of skin microbiota. By employing 16S rRNA sequencing, we characterized the skin microbiome of the mouse model. Our results demonstrate that microbiota intervention significantly reduces skin thickening and serum IgE levels in DNFB-induced AD mice. Additionally, changes in skin microbiota modulated immune cell dynamics, restoring the Th1/Th2 balance and leading to clinical improvement. These findings highlight the critical role of skin microbiota in shaping immune responses, positioning microbiota-based therapies as a potential treatment for AD.

Comparison of Supra-Alar Crease Deepening Following Septorhinoplasty in Two Techniques: Lateral Crura Steal Versus Lateral Crura Overlay.

Nasal tip correction is one of the most challenging parts of rhinoplasty. The objective of the study was to compare the prevalence of supra-alar crease deepening in lateral crura steal (LCS) and lateral crura overlay (LCO) techniques. In this prospective study, eligible patients referred to a university hospital for septorhinoplasty during 2022 were included. The study was conducted on 200 patients in two groups (100 patients in each group), 162 were women and 38 men with a mean age of 31.12±0.60 years. In the third month of follow-up, 36.5% of all studied patients had supra-alar crease deepening, of whom 13% were in the interrupt group and 23.5% were in the steal group (P=0.002); however, only 4% in the LCO and 9% in the LCS group had aesthetic or breathing disorders (P=0.25). Deepening of the alar crease was not significantly related to the skin thickness in the two techniques. According to the results, both LCO and LCS techniques are effective in achieving successful outcomes, although the problematic supra-alar crease deepening is less common in the LCO group; therefore, it seems to be a more suitable option in cases where there is a greater need to tip rotation, although this finding was not statistically significant. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The pivotal role of osteopontin in UV-induced skin inflammation in a mouse model.

Osteopontin (OPN) is a pro-inflammatory protein that influences bone remodelling, wound healing, angiogenesis, allergic inflammation, and skin diseases such as psoriasis, contact dermatitis and skin cancer. However, the role of OPN in the skin remains unclear. Therefore, this study aimed to investigate the role of OPN in the skin, particularly in the context of ultraviolet (UV) irradiation-induced inflammation. OPN expression and its effects on inflammatory modulators were assessed in human skin, in a mouse model and in vitro, using a UV source emitting both UVB and UVA radiation, which collectively contribute to UV-induced skin inflammation. OPN expression increased in human and mouse skin after UV irradiation. Compared with wild-type mice, UV irradiation-induced skin phenotypes, such as erythema and skin thickening, were alleviated in OPN-/- mice. In addition, the number of immune cells recruited to the skin after UV irradiation and the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) were observed to be decreased in the skin of OPN-/- mice compared with that of wild-type mice. By contrast, the degree of skin inflammation was higher in the hOPN KI mice than in wild-type mice. Treatment with recombinant OPN increased the expression of MMP-1 and inflammatory cytokines in human dermal fibroblasts and epidermal keratinocytes in vitro. Our results suggest that OPN may play a regulatory role in UV-induced skin inflammation.