Comparative study of various growth factors and cytokines on type I collagen and hyaluronan production in human dermal fibroblasts

Current application of tissue-engineered dermal scaffolds mimicking the extracellular matrix microenvironment in wound healing

With the continuous advancement of materials science, cell biology, and biotechnology, tissue engineering has introduced novel solutions to traditional wound healing approaches, particularly demonstrating significant potential in addressing complex or non-healing wounds. One of the key technologies in this field, dermal scaffolds, serve as wound coverage materials that mimic the structural framework of the dermis. They primarily assume the function of extracellular matrix, providing space for cell attachment, migration, and proliferation, thus supporting cellular growth and regulating multiple biological processes in healing. Tissue engineering utilizes combinations of natural or synthetic scaffolds, seeded cells, or growth factors to induce distinct effects in angiogenesis, extracellular matrix deposition, and functional recovery. Therefore, various bioengineered dermal scaffolds hold significant potential for clinical translation in wound healing. This review outlines various extracellular matrix molecules utilized in the development of dermal scaffolds, emphasizes recent progress in cell- and growth factor-modified scaffolds, and discusses the challenges and future perspectives in this evolving field.

Cadmium promotes hyaluronan synthesis by inducing hyaluronan synthase 3 expression in cultured vascular endothelial cells via the c-Jun N-terminal kinase-c-Jun pathway

Cadmium is a heavy metal risk factor for various cardiovascular diseases, such as atherosclerosis. In atherosclerotic lesions, hyaluronan, a glycosaminoglycan consisting of β4-glucuronic acid-β3-N-acetylglucosamine disaccharides repeats, is highly accumulated, regulating signal transduction, cell migration, and angiogenesis. Hyaluronan is synthesized by hyaluronan synthase (HAS)1-3 in the plasma membrane and secreted into the extracellular space. Hyaluronan derived from HAS3 promotes inflammatory responses. Recently, we found that cadmium elongates chondroitin/dermatan sulfate chains in vascular endothelial cells and that glycosaminoglycan sugar chains are potential targets for the vascular toxicity of cadmium. Therefore, hyaluronan, a glycosaminoglycan sugar chain, may also affected by cadmium; however, this has not yet been clarified. In this study, we aimed to analyze the effect of cadmium on hyaluronan synthesis using cultured aortic endothelial cells. Cadmium at a concentration of 2 µM upregulated hyaluronan synthesis in the medium and specifically induced HAS3 mRNA and protein expression. However, cadmium-mediated HAS3 induction was abolished by the inhibition of the c-Jun N-terminal kinase (JNK)-c-Jun pathway. Moreover, JNK inhibition prevented the increase in hyaluronan levels in the medium. These results revealed that the JNK-c-Jun pathway was involved in HAS3-mediated hyaluronan synthesis by cadmium in vascular endothelial cells, suggesting that endothelial HAS3 induction contributes to atherosclerotic lesion formation by promoting inflammatory responses.

Molecular farming expression of recombinant fusion proteins applied to skincare strategies

This review discusses the current research progress in molecular farming technology in the field of skincare, with an emphasis on molecular farming expression strategies. The strategies of transdermal drug delivery and their advantages are also highlighted. The expression of cosmetically relevant fused proteins has become an important way to enhance the efficacy of the proteins. Therefore, we also discuss the feasibility and strategies for expressing fusion proteins in A. thaliana, specifically the fusion of Epidermal growth factor (EGF) to a cell-penetrating peptide (CPP), in which the production can be greatly enhanced via plant expression systems since these systems offer higher biosecurity, flexibility, and expansibility than prokaryotic, animal and mammalian expression systems. While the fusion of EGF to CCP can enhance its transdermal ability, the effects of the fusion protein on skin repair, melasma, whitening, and anti-aging are poorly explored. Beyond this, fusing proteins with transdermal peptides presents multiple possibilities for the development of tissue repair and regeneration therapeutics, as well as cosmetics and beauty products. As certain plant extracts are known to contain proteins beneficial for skin health, the expression of these proteins in plant systems will better maintain their integrity and biological activities, thereby facilitating the development of more effective skincare products.

Bioinspired Collagen/Hyaluronic Acid/Fibrin-Based Hydrogels for Soft Tissue Engineering: Design, Synthesis, and In Vitro Characterization

A major challenge for future drug development comprises finding alternative models for drug screening. The use of animal models in research is highly controversial, with an ongoing debate on their ethical acceptability. Also, animal models are often poorly predictive of therapeutic outcomes due to the differences between animal and human physiological environments. In this study, we aimed to develop a biomimetic hydrogel that replicates the composition of skin for potential use in in vitro modeling within tissue engineering. The hydrogel was fabricated through the crosslinking of collagen type I, hyaluronic acid, four-arm PEG succinimidyl glutarate (4S-StarPEG), and fibrinogen. Various ratios of these components were systematically optimized to achieve a well-interconnected porosity and desirable rheological properties. To evaluate the hydrogel's cytocompatibility, fibroblasts were embedded within the matrix. The resulting hydrogel exhibited promising properties as a scaffold, also facilitating the growth of and proliferation of the cells. This biomimetic hydrogel holds great potential for tissue engineering applications, particularly in skin regeneration and cancer research. The study used melanoma spheroids fabricated using the 96-round bottom well plate method as a potential application. The results demonstrate that the developed hydrogels allowed the maintenance of spheroid integrity and viability, meaning it has a promising use as a three-dimensional in vitro model of melanoma for both tissue engineering and drug screening applications.

Pre-treatment of oncolytic reovirus improves tumor accumulation and intratumoral distribution of PEG-liposomes

PEGylated liposomes (PEG-liposomes) are a promising drug delivery vehicle for tumor targeting because of their efficient tumor disposition profiles via the enhanced permeability and retention (EPR) effect. However, tumor targeting of PEG-liposomes, particularly their delivery inside the tumors, is often disturbed by physical barriers in the tumor, including tumor cells themselves, extracellular matrices, and interstitial pressures. In this study, B16 melanoma tumor-bearing mice were injected intravenously with oncolytic reovirus before administration of PEG-liposomes to enhance PEG-liposomes' tumor disposition. Three days after reovirus administration, significant expression of reovirus sigma 3 protein, elevation of apoptosis-related gene expression, and activation of caspase 3 in the tumors were found. Apoptotic cells were found inside the tumors. These data indicated that reovirus efficiently replicated in the tumors and induced apoptosis of tumor cells. The tumor disposition levels of PEG-liposomes were approximately doubled by reovirus pre-administration, compared with a PBS-pretreated group. PEG-liposomes were widely distributed in the tumors of reovirus-pretreated mice, whereas in the PBS-pretreated group, PEG-liposomes were found mainly around or inside the blood vessels in the tumors. Pre-treatment with reovirus also improved the tumor accumulation of PEG-liposomes in human pancreatic BxPC-3 tumors. 3D imaging analysis of whole BxPC-3 tumors demonstrated that pretreatment with reovirus led to the enhancement of PEG-liposome accumulation inside the tumors. Combination treatment with reovirus and paclitaxel-loaded PEG-liposomes (PTX-PEG-liposomes) significantly suppressed B16 tumor growth. These results provide important information for clinical use of combination therapy of reovirus and nanoparticle-based drug delivery system (DDS).

Inflammation-Driven Secretion Potential Is Upregulated in Osteoarthritic Fibroblast-Like Synoviocytes

Osteoarthritis (OA) is one of the most common joint pathologies and a major cause of disability among the population of developed countries. It manifests as a gradual degeneration of the cartilage and subchondral part of the bone, leading to joint damage. Recent studies indicate that not only the cells that make up the articular cartilage but also the synoviocytes, which build the membrane surrounding the joint, contribute to the development of OA. Therefore, the aim of the study was to determine the response to inflammatory factors of osteoarthritic synoviocytes and to identify proteins secreted by them that may influence the progression of OA. This study demonstrated that fibroblast-like synoviocytes of OA patients (FLS-OA) respond more strongly to pro-inflammatory stimulation than cells obtained from control patients (FLS). These changes were observed at the transcriptome level and subsequently confirmed by protein analysis. FLS-OA stimulated by pro-inflammatory factors [such as lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFα) were shown to secrete significantly more chemokines (CXCL6, CXCL10, and CXCL16) and growth factors [angiopoietin-like protein 1 (ANGPTL1), fibroblast growth factor 5 (FGF5), and insulin-like growth factor 2 (IGF2)] than control cells. Moreover, the translation of proteolytic enzymes [matrix metalloprotease 3 (MMP3), cathepsin K (CTSK), and cathepsin S (CTSS)] by FLS-OA is increased under inflammatory conditions. Our data indicate that the FLS of OA patients are functionally altered, resulting in an enhanced response to the presence of pro-inflammatory factors in the environment, manifested by the increased production of the previously mentioned proteins, which may promote further disease progression.

Functional responses of dermal fibroblasts to low nutrition and pro-inflammatory stimuli mimicking a wound environment in vitro

Dermal fibroblasts (DF) constitute one of key cells involved in wound healing. However, the functions they perform in wound conditions remain poorly understood. This study involved exposing DF to low nutrition and to low nutrition + LPS for 5 d as conditions representing the wound. Although DF exhibited increasing metabolic activity in time under all conditions including control, the proliferation did not change in both low nutrition and low nutrition + LPS. Only the low nutrition + LPS was found to potentiate the migration and pro-inflammatory phenotype (IL6 release) of DF. The potential of DF to contract collagen hydrogel declined only under low nutrition as a consequence of low cell number. The expression of α-SMA was reduced under both conditions independently of the cell number. The remodeling capability of DF was affected under both conditions as documented by the enhanced MMP2 activity. Finally, the production of collagen type I was not affected by either condition. The study shows that low nutrition as the single factor is able to delay the healing process. Moreover, the addition of the mild pro-inflammatory stimulus represented by LPS may amplify the cell response in case of decreased α-SMA expression or excite DF to produce IL6 impairing the healing process.

The emerging therapeutic targets for scar management: genetic and epigenetic landscapes

Background

Wound healing is a complex process including hemostasis, inflammation, proliferation, and remodeling during which an orchestrated array of biological and molecular events occurs to promote skin regeneration. Abnormalities in each step of the wound healing process lead to reparative rather than regenerative responses, thereby driving the formation of cutaneous scar. Patients suffering from scars represent serious health problems such as contractures, functional and esthetic concerns as well as painful, thick, and itchy complications, which generally decrease the quality of life and impose high medical costs. Therefore, therapies reducing cutaneous scarring are necessary to improve patients' rehabilitation.

Summary

Current approaches to remove scars, including surgical and nonsurgical methods, are not efficient enough, which is in principle due to our limited knowledge about underlying mechanisms of pathological as well as the physiological wound healing process. Thus, therapeutic interventions focused on basic science including genetic and epigenetic knowledge are recently taken into consideration as promising approaches for scar management since they have the potential to provide targeted therapies and improve the conventional treatments as well as present opportunities for combination therapy. In this review, we highlight the recent advances in skin regenerative medicine through genetic and epigenetic approaches to achieve novel insights for the development of safe, efficient, and reproducible therapies and discuss promising approaches for scar management.

Key Message

Genetic and epigenetic regulatory switches are promising targets for scar management, provided the associated challenges are to be addressed.

M2 Macrophage-Derived Concentrated Conditioned Media Significantly Improves Skin Wound Healing

BACKGROUND

Macrophages, with many different phenotypes play a major role during wound healing process, secreting the cytokines crucial to angiogenesis, cell recruitment and ECM remodeling. Therefore, macrophage-derived cytokines may be attractive therapeutic resource for wound healing.

METHODS

To obtain a conditioned media (CM) from macrophages, human monocyte THP-1 cells were seeded on TCP or human fibroblast-derived matrix (hFDM) and they were differentiated into M1 or M2 phenotype using distinct protocols. A combination of different substrates and macrophage phenotypes produced M1- and M2-CM or M1-hFDM- and M2-hFDM-CM, respectively. Proteome microarray determines the cytokine contents in those CMs. CMs-treated human dermal fibroblast (hDFB) was analyzed using collagen synthesis and wound scratch assay. Concentrated form of the CM (CCM), obtained by high-speed centrifugation, was administered to a murine full-thickness wound model using alginate patch, where alginate patch was incubated in the M2-CCM overnight at 4 °C before transplantation. On 14 day post-treatment, examination was carried out through H&E and Herovici staining. Keratinocyte and M2 macrophages were also evaluated via immunofluorescence staining.

RESULTS

Cytokine analysis of CMs found CCL1, CCL5, and G-CSF, where CCL5 is more dominant. We found increased collagen synthesis and faster wound closure in hDFB treated with M2-CM. Full-thickness wounds treated by M2-hFDM-CCM containing alginate patch showed early wound closure, larger blood vessels, increased mature collagen deposition, enhanced keratinocyte maturation and more M2-macrophage population.

CONCLUSION

Our study demonstrated therapeutic potential of the CM derived from M2 macrophages, where the cytokines in the CM may have played an active role for enhanced wound healing.

Detection of genomic structure variants associated with wrinkled skin in Xiang pig by next generation sequencing

Wrinkling is prominent manifestation of aging skin. A mutant phenotype characterized by systemic wrinkles and thickened skin was discovered in Xiang pig populations with incidence about 1-3%. The feature in histological structure was epidermal hyperplasia and thickening, collagen fibers disorder. To uncover genetic mechanisms for the mutant phenotype of Xiang pigs with systemic wrinkle (WXP), a genome-wide of structural variations (SVs) in WXP was described by next generation resequencing, taking Xiang pigs (XP) and European pigs (EUP) as compares. Total of 32,308 SVs were detected from three pig groups and 965 SVs were identified specifically from WXP, involving 481 protein-coding genes. These genes were mainly enriched in nuclear structure, ECM components and immunomodulatory pathways. According to gene function and enrichment analysis, we found that 65 candidate SVs in 59 protein genes were probably related with the systemic wrinkle of WXP. Of these, several genes are reported to be associate with aging, such as EIF4G2, NOLC1, XYLT1, FUT8, MDM2 and so on. The insertion/deletion and duplication variations of SVs in these genes resulted in the loss of stop-codon or frameshift mutation, and aberrant alternative splicing of transcripts. These genes are involved in cell lamin filament, intermediate filament cytoskeleton, supramolecular complex, cell differentiation and regulation of macromolecule metabolic process etc. Our study suggested that the loss of function or aberrant expression of these genes lead to structural disorder of nuclear and the extracellular matrix (ECM) in skin cells, which probably was the genetic mechanisms for the mutant phenotype of systemic skin wrinkle of Xiang pig.

In vivo study of the effects of a portable cold plasma device and vitamin C for skin rejuvenation

Nowadays, cold atmospheric plasma shows interesting results in dermatology. In the present study, a new portable cold plasma was designed for plasma skin rejuvenation (PSR) purposes. This device is safe and easy to use at beauty salons and homes. The effects of this device were investigated on the rat skins. Also, as a new method to improve PSR results, vitamin C ointment was combined with plasma. In this study, there were four groups of 5 Wistar rats. The first group received vitamin C ointment, the second received 5 min of high-voltage plasma, and the third and the fourth groups received 5 min of high- and low-voltage plasma and vitamin C ointment. This process was done every other day (3 sessions per week) for 6 weeks. To evaluate the thermal effect of plasma, the skin temperature was monitored. Also, the presence of reactive species was demonstrated by the use of optical spectroscopy. In addition, mechanical assays were performed to assess the effect of plasma and vitamin C on the tissue's mechanical strength. The mechanical assays showed a positive impact of plasma on the treated tissue compared to the control group. Also, changes in the collagen level and thickness of the epidermal layer were examined in histological studies. The results indicated an increase in collagen levels after using plasma alone and an accelerated skin reaction after using vitamin C combined with plasma therapy. The epidermal layer's thickness increased after applying high-voltage plasma, which indicates an increase in skin elasticity. This study demonstrates the positive effect of using the portable plasma device with vitamin C ointment on effective parameters in skin rejuvenation.

Engineering Bioactive Scaffolds for Skin Regeneration

Large skin wounds pose a major clinical challenge. Scarcity of donor site and postsurgical scarring contribute to the incomplete or partial loss of function and aesthetic concerns in skin wound patients. Currently, a wide variety of skin grafts are being applied in clinical settings. Scaffolds are used to overcome the issues related to the misaligned architecture of the repaired skin tissues. The current review summarizes the contribution of biomaterials to wound healing and skin regeneration and addresses the existing limitations in skin grafting. Then, the clinically approved biologic and synthetic skin substitutes are extensively reviewed. Next, the techniques for modification of skin grafts aiming for enhanced tissue regeneration are outlined, and a summary of different growth factor delivery systems using biomaterials is presented. Considering the significant progress in biomaterial science and manufacturing technologies, the idea of biomaterial-based skin grafts with the ability for scarless wound healing and reconstructing full skin organ is more achievable than ever.

Serum extracellular vesicles containing MIAT induces atrial fibrosis, inflammation and oxidative stress to promote atrial remodeling and atrial fibrillation via blockade of miR-485-5p-mediated CXCL10 inhibition

BACKGROUND

Atrial fibrillation (AF), a supraventricular arrhythmia that impairs cardiac function, is a main source of morbidity and mortality. Serum-derived extracellular vesicles (EVs) have been identified to carry potential biomarker or target for the diagnosis and treatment of AF. We intended to dissect out the role of lncRNA MIAT enriched in serum-derived EVs in AF.

METHODS

MIAT expression was quantified in EVs isolated from serum samples of AF patients. Mouse and cell models of AF were developed after angiotensin II (Ang II) induction. Relationship between MIAT, miR-485-5p, and CXCL10 was identified. Ectopic expression and depletion assays were implemented in Ang II-treated mice or HL-1 cells, or those co-cultured with serum-derived EVs to explore the roles of EV-carried MIAT.

RESULTS

MIAT was upregulated in EVs from serum samples of AF patients. Further analysis indicated that MIAT enriched in serum-derived EVs promoted atrial fibrosis, inflammation and oxidative stress, and aggravated the atrial remodeling and resultant AF. Mechanistically, MIAT bound to miR-485-5p and weakened its inhibitory role on the target CXCL10, which was responsible for the role of serum-derived EV containing MIAT in cellular fibrosis, oxidative stress and inflammation, and atrial remodeling in vivo.

CONCLUSIONS

In conclusion, serum-derived EV containing MIAT facilitates atrial remodeling and exacerbates the AF by abolishing the miR-485-5p-mediated CXCL10 inhibition. This finding aids in the deeper understanding about the pathophysiology of AF.

In vitro and in vivo Effect of Platelet-Rich Plasma-Based Autologous Topical Serum on Cutaneous Wound Healing

INTRODUCTION

Skin injury and wound healing is an inevitable event during lifetime. However, several complications may hamper the regeneration of the cutaneous tissue and lead to a chronic profile that prolongs patient recovery. Platelet-rich plasma is rising as an effective and safe alternative to the management of wounds. However, this technology presents some limitations such as the need for repeated blood extractions and health-care interventions.

OBJECTIVE

The aim of this study was to assess the use of an endogenous and storable topical serum (ES) derived from plasma rich in growth factors promoting wound healing, and to obtain preliminary data regarding its clinical and experimental effect over ulcerated skin models and patient care.

METHODS

Human dermal fibroblast and 3D organotypic ulcerated skin models were used to assess ES over the main mechanisms of wound healing including cell migration, edge contraction, collagen synthesis, tissue damage, extracellular matrix remodeling, cell death, metabolic activity, and histomorphometry analysis. Additionally, 4 patients suffering from skin wounds were treated and clinically assessed.

RESULTS

ES promoted dermal fibroblast migration, wound edge contraction, and collagen synthesis. When topically applied, ES increased collagen and elastin deposition and reduced tissue damage. The interstitial edema, structural integrity, and cell activity were also maintained, and apoptotic levels were reduced. Patients suffering from hard-to-heal wounds of different etiologies were treated with ES, and the ulcers healed completely within few weeks with no reported adverse events.

CONCLUSION

This preliminary study suggests that ES might promote cutaneous wound healing and may be useful for accelerating the re-epithelization of skin ulcers.

Dermal fibroblasts have different extracellular matrix profiles induced by TGF-β, PDGF and IL-6 in a model for skin fibrosis

Different stimulants might induce different extracellular matrix profiles. It is essential to gain an understanding and quantification of these changes to allow for focused anti-fibrotic drug development. This study investigated the expression of extracellular matrix by dermal fibroblast mimicking fibrotic skin diseases as SSc using clinically validated biomarkers. Primary healthy human dermal fibroblasts were grown in media containing FICOLL. The cells were stimulated with PDGF-AB, TGF-β1, or IL-6. Anti-fibrotic compounds (iALK-5, Nintedanib) were added together with growth factors. Biomarkers of collagen formation and degradation together with fibronectin were evaluated by ELISAs in the collected supernatant. Immunohistochemical staining was performed to visualize fibroblasts and proteins, while selected gene expression levels were examined through qPCR. TGF-β and PDGF, and to a lesser extent IL-6, increased the metabolic activity of the fibroblasts. TGF-β primarily increased type I collagen and fibronectin protein and gene expression together with αSMA. PDGF stimulation resulted in increased type III and VI collagen formation and gene expression. IL-6 decreased fibronectin levels. iALK5 could inhibit TGF-β induced fibrosis while nintedanib could halt fibrosis induced by TGF-β or PDGF. Tocilizumab could not inhibit fibrosis induced in this model. The extent and nature of fibrosis are dependent on the stimulant. The model has potential as a pre-clinical model as the fibroblasts fibrotic phenotype could be reversed by an ALK5 inhibitor and Nintedanib.

Silver Nanoparticles Alter Cell Viability Ex Vivo and in Vitro and Induce Proinflammatory Effects in Human Lung Fibroblasts

Silver nanoparticles (AgNPs) are commonly used in commercial and medical applications. However, AgNPs may induce toxicity, extracellular matrix (ECM) changes and inflammatory responses. Fibroblasts are key players in remodeling processes and major producers of the ECM. The aims of this study were to explore the effect of AgNPs on cell viability, both ex vivo in murine precision cut lung slices (PCLS) and in vitro in human lung fibroblasts (HFL-1), and immunomodulatory responses in fibroblasts. PCLS and HFL-1 were exposed to AgNPs with different sizes, 10 nm and 75 nm, at concentrations 2 µg/mL and 10 μg/mL. Changes in synthesis of ECM proteins, growth factors and cytokines were analyzed in HFL-1. Ag10 and Ag75 affected cell viability, with significantly reduced metabolic activities at 10 μg/mL in both PCLS and HFL-1 after 48 h. AgNPs significantly increased procollagen I synthesis and release of IL-8, prostaglandin E₂, RANTES and eotaxin, whereas reduced IL-6 release was observed in HFL-1 after 72 h. Our data indicate toxic effects of AgNP exposure on cell viability ex vivo and in vitro with altered procollagen and proinflammatory cytokine secretion in fibroblasts over time. Hence, careful characterizations of AgNPs are of importance, and future studies should include timepoints beyond 24 h.

Up-regulation of IGF-1, RANTES and VEGF in patients with anti-centromere antibody-positive early/mild systemic sclerosis

OBJECTIVE

Multiple cytokine network may control the pathogenesis of vasculopathy in patients with systemic sclerosis (SSc). We aimed at comparing angiogenic cytokine profile among SSc patients at various clinical stage.

METHODS

We divided nine patients with anti-centromere antibody (ACA) who were suspected of SSc and diagnosed as having SSc into three groups (group1: pre-clinical stage of SSc, group2: mild/early SSc and group3: typical lcSSc) according to the ACR/EULAR2013 classification criteria or ACR1980 preliminary classification, and serum sample were obtained from them. We evaluated the expression levels of 20 cytokines by membrane array.

RESULTS

Average values of EGF, ENA-78, bFGF, IGF-I, IL-8, MCP-1, TGF-β1, thrombopoietin, VEGF and VEGF-D in group2 were increased compared as those of group1 more than twofold. Statistically significant difference was found in serum levels of IGF-1, RANTES and VEGF between group1 and group2. There was also significant difference in the value of VEGF between group1 and group3. There were mild and significant correlations between serum IGF-1 and RANTES levels (r = 0.721, p = .028).

CONCLUSION

IGF-1, RANTES and VEGF are thought to be involved in the disease development from pre-clinical stage of SSc to early/mild SSc. Thus, these cytokines may be utilized as a biomarker for early diagnosis.

A Potato Peel Extract Stimulates Type I Collagen Synthesis via Akt and ERK Signaling in Normal Human Dermal Fibroblasts

The ability of dermal fibroblasts to synthesize collagen decreases with ages. The integrity of collagen fibers severely decreases in aged skin, causing its characteristic morphological changes such as wrinkles and sagging. To prevent and improve skin aging, the stimulation of collagen synthesis in dermal fibroblasts is important. Potato peels contain many biofunctional compounds, but not much is known about their effects on human skin physiology. To characterize the potential effects of a potato peel extract (PPE) against skin aging, we examined its effects on the synthesis of type I collagen by normal human dermal fibroblasts (NHDFs). Treatment with the PPE significantly increased the expression of type I collagen mRNA in NHDFs and their secretion of type I collagen. To elucidate the mechanism involved, we examined the signaling pathway controlled by transforming growth factor-β (TGF-β), which regulates the synthesis of type I collagen. Treatment of NHDFs with the PPE significantly increased the expression of TGF-β receptor mRNA. TGF-β signaling involves Smad-dependent and Smad-independent pathways, like phosphatidylinositol-3 kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK). The PPE did not activate Smad, but significantly activated Akt and ERK. These results demonstrate that the PPE activates PI3K/Akt and MAPK/ERK signals via TGF-β receptors, which stimulate the synthesis of type I collagen in NHDFs. These results suggest that the PPE could be a novel and effective antiaging material.

The effect of nitrogen plasma on the skin and hair follicles: a possible promising future for the treatment of alopecia

Nowadays, there is a great attention to the plasma applications in medicine. Not only does cold atmospheric pressure plasma provide a therapeutic opportunity to control redox-based processes, it is also an innovative method in rejuvenation. Given the current interest in new methods of rejuvenation, we aimed to introduce a novel pulsed nitrogen plasma torch with potential use in rejuvenation. We investigated production of reactive species at different pulse energy by spectroscopy and also measured nitric oxide and O₂ concentration and evaluated the flame temperature. Fifteen Wistar rats were divided into three groups based on the applied energy settings; the skin of the animals was processed with plasma. For quantitative evaluation of dermis, epidermis and hair follicles (to confirm the effects of this technique on rejuvenation), skin biopsies were taken from both unexposed and treated areas. The spectroscopy results showed the presence of nitric oxide in plasma and the concentration was suitable for dermatological applications. A significant increase was observed in epidermal thickness, fibroblast cell proliferation and collagenesis (P < 0.05). Interestingly, plasma led to a temporary increase in the diameter of primary and secondary hair follicles compared to the controls. The results confirmed the positive effects of this pulsed nitrogen plasma torch on rejuvenation and also revealed a new possible aspect of cold plasma; its effect on hair follicles as a promising area in the treatment of alopecia that requires further clinical and molecular studies.

Anti‑photoaging and anti‑oxidative activities of natural killer cell conditioned medium following UV‑B irradiation of human dermal fibroblasts and a reconstructed skin model

Conditioned media from various sources comprise numerous growth factors and cytokines and are known to promote the regeneration of damaged tissues. Among these, natural killer cell conditioned medium (NK‑CdM) has been shown to stimulate collagen synthesis and the migration of fibroblasts during the wound healing process. With a long‑term aim of developing a treatment for skin photoaging, the ability of NK‑CdM to prevent ultraviolet‑B (UV‑B) damage was assessed in neonatal human dermal fibroblasts (NHDFs) and an in vitro reconstructed skin model. The factors present in NK‑CdM were profiled using an antibody array analysis. Protein and mRNA levels in UV‑B exposed NHDFs treated with NK‑CdM were measured by western blotting and quantitative reverse transcription‑PCR, respectively. The total antioxidant capacity of NK‑CdM was determined to assess its ability to suppress reactive oxygen species. The anti‑photoaging effect of NK‑CdM was also assessed in a 3D reconstituted human full skin model. NK‑CdM induced proliferation of UV‑B‑treated NHDFs, increased procollagen expression, and decreased matrix metalloproteinase (MMP)‑1 expression. NK‑CdM also exhibited a potent antioxidant activity as measured by the total antioxidant capacity. NK‑CdM inhibited UV‑B‑induced collagen degradation by inactivating MAPK signaling. NK‑CdM also elicited potential anti‑wrinkle effects by inhibiting the UV‑B‑induced increase in MMP‑1 expression levels in a 3D reconstituted human full skin model. Taken together, the suppression of both UV‑B‑induced MMP‑1 expression and JNK activation by NK‑CdM suggests NK‑CdM as a possible candidate anti‑skin aging agent.

Adipose-derived stem cell-conditioned medium protects fibroblasts at different senescent degrees from UVB irradiation damages

Adipose-derived stem cells (ADSCs) and their derivatives have aroused intense interest in fields of dermatological and aesthetic medicine. As a major component detected in ADSCs secretome, platelet-derived growth factor AA (PDGF-AA) has been reported mediating extracellular matrix deposition and remodeling, thus might contribute to its anti-aging effect. On the basis of establishing an experimental model that simulate actual skin aging by exposing HDFs to both intrinsic and extrinsic aging factors, we pretreated human dermal fibroblasts (HDFs) with ADSC-conditioned medium (ADSC-CM) before being irradiated, aiming at exploring preventive effects of ADSCs secretome against aging damages. 48 h after irradiation, we detected cellular proliferation; β-galactosidase stain; mRNA expressions of MMP-1, MMP-9, and TIMP-1; and protein expressions of collagen I, collagen III, and elastin. Moreover, we detected related protein expression of PI3K/Akt signal pathway, which can be activated by PDGF-AA and was newly found to promote extracellular matrix protein synthesis. Concentration of PDGF-AA in the prepared ADSC-CM decreased over time and maintained excellent bioactivity at low temperature until the 11th week. ADSC-CM pretreatment can slightly or significantly improve cellular proliferative activity and reduce cellular senescence in irradiated HDFs. Besides, ADSC-CM pretreatment increased collagen I, collagen III, elastin, and TIMP-1 expressions but decreased MMP-1 and MMP-9 expressions both in irradiated and nonirradiated HDFs. ADSC-CM pretreatment significantly increased pAkt protein expression, and ECM protein expression greatly decreased in case of LY294002 application. The results were similar in three generations of HDFs, yet varied with different degrees. Generally, ADSC-CM we prepared demonstrates a certain degree of positive role in preventing HDFs from intrinsic and extrinsic aging damages and that PDGF-AA may contribute to making it become effective with some other components in ADSC-CM.

Dracohodin Perochlorate Stimulates Fibroblast Proliferation via EGFR Activation and Downstream ERK/CREB and PI3K/Akt/mTOR Pathways In Vitro

In recent years, an increasing number of natural plant extracts have been determined to be potential drugs for various illnesses. In this study, we investigated the effects of dracorhodin perchlorate (DP) on fibroblast proliferation, which is crucial for wound healing. Cell proliferation assays were performed by different concentrations of DP, and the cell viability was detected by CCK-8 kits. After DP treatment for 24 h, the cell cycle was checked by flow cytometer. EGFR and downstream signaling pathways ERK1/2 and PI3K were examined with DP treatment by western blot. We further determined the effects of the related inhibitors on DP-induced relative protein phosphorylation and cell proliferation. The results showed that 3 μg/mL of DP promoted cell proliferation most significantly at treatment lengths of 24 h, and the percentage of cells in the S + G2 phase increased compared to those of the control group. In western blot detection, we found that DP significantly upregulated EGFR phosphorylation and activated the downstream ERK/CREB and PI3K/Akt/mTOR signaling pathway. Moreover, the results also showed that AG1478 abolished DP-induced relative protein activation and cell proliferation. When U0126 or LY294002 pretreated cells alone, DP-induced p-ERK or p-PI3K downstream proteins and cell proliferation were suppressed compared to those of the control group, but EGFR was not affected. In addition, ICG001 and BEZ235 collectively eliminated DP-induced fibroblast proliferation. Our findings suggest that DP-promoted fibroblast proliferation is stimulated by p-EGFR-induced activation of the ERK1/2-CREB and PI3K/Akt/mTOR pathways. Our present study explored the mechanism of DP-promoted fibroblast proliferation and provided a new basis for wound healing.

Immunotherapy: breaching the barriers for cancer treatment

The great ambition to treat cancer through harnessing a patient's own immune responses has started to become reality. Clinical trials have shown impressive results and some patients reaching the end of existing treatment options have achieved full remission. Yet the response rate even within the most promising trials remain at just 30-40% of patients. To date, the focus of immunotherapy research has been to identify tumour antigens, and to enhance activation of effector lymphocytes. Yet this is only the first step to effective immunotherapy for a broader range of patients. Activated cytotoxic T cells can only act on their tumour cell targets if they have free and easy access to all tumour regions. Solid tumours are complex, heterogeneous environments which vary greatly in their physical properties. We must now focus our efforts on understanding how factors such as the composition, density and geometry of tumour extracellular matrix acts to impede or promote immune cell infiltration and activation, and work to design novel pharmacological interventions which restore and enhance leucocyte trafficking within solid tumours. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.

Age related changes in the dermal mast cells and the associated changes in the dermal collagen and cells: A histological and electron microscopy study

Mast cells are widely distributed bone marrow cells. They have a crucial role in the dermal aging process. The aim of the present study was to describe the biochemical and the histological changes that occur in the aged dermal mast cells and to demonstrate the associated changes in the dermal cells and fibers as well. Sixteen male albino rats were used and divided into two groups; the control group (8-10 weeks) and the aged group (20-22 weeks). The rats were decapitated then processed for further biochemical and histological studies. The mean area fraction for collagen fibers was measured. In the aged group, there was a significant increase in the skin histamine and heparin levels if compared with the control one. Furthermore, there was an apparent increase in intact and degranulated dermal mast cells if compared with the control one. The dermal collagen bundles were apparently decreased and appeared distorted with wide spacing. Additionally, there were apparently large sized eosinophils with more cytoplasmic granules. Direct contact between mast, fibroblast, and macrophage cells was noticed. The average area fraction of collagen fibers was significantly increased in the aged group if compared with the control one. It could be concluded that the secretory activity of dermal mast cells was significantly increased in the aged skin group. Also, this study demonstrated the implicated role of mast cell in aged skin changes. Further long-term studies are needed to validate the prophylactic or therapeutic potential by intentional hindering of mast cell degranulation in aged skin.

Normal and keloid fibroblasts are differentially influenced by IFN-γ and triamcinolone as well as by their combination

Impaired wound healing as well as imbalanced cell proliferation and extracellular matrix synthesis and degeneration can cause aberrant scarring. The most severe impacts of such scarring on patients' lives are stigmatization and physical restriction. Although, a broad variety of combinatorial approaches with, e.g., glucocorticoids, chemotherapeutics, and immunomodulators are used, there is still a high recurrence rate of keloids. The aim of this study was to investigate which influence interferon γ (IFN-γ, 1.000-10.000 IU/mL) and/or triamcinolone acetonide (TA, 1 μg/mL) have on proliferation, cell viability, collagen type I synthesis, and cytokine secretion in healthy and keloid fibroblasts. It was shown that mono-treatment with IFN-γ or TA for 2 days induced a severe reduction of the proliferative potential in both cell species. The combinatory treatment (IFN-γ plus TA) of keloid fibroblasts enhanced the anti-proliferative effect of the mono-treatments, whereas no additional anti-proliferative effect was observed in normal fibroblasts. Furthermore, we observed that the combinatory treatment regimen reduced the expression of α-smooth muscle actin (α-SMA), an actin isotype contributing to cell-generated mechanical tension, in keloid fibroblasts. In normal fibroblasts, α-SMA was reduced by the mono-treatment with IFN-γ as well as by the combinatory treatment. The analysis of collagen-type I synthesis revealed that TA did not reduce collagen type I synthesis in normal fibroblasts but in keloid fibroblasts. IFN-γ reduced in both cell species the collagen type I synthesis. The combination of TA and IFN-γ intensified the previously observed collagen type I synthesis reduction in keloid fibroblasts. The herein presented data suggest the combinatory application of IFN-γ and TA as a promising therapy concept for keloids.

Effect of Optimized Concentrations of Basic Fibroblast Growth Factor and Epidermal Growth Factor on Proliferation of Fibroblasts and Expression of Collagen: Related to Pelvic Floor Tissue Regeneration

Background:

Fibroblasts were the main seed cells in the studies of tissue engineering of the pelvic floor ligament. Basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) were widely studied but at various concentrations. This study aimed to optimize the concentrations of combined bFGF and EGF by evaluating their effects on proliferation and collagen secretion of fibroblasts.

Methods:

Fibroblasts were differentiated from rat adipose mesenchymal stem cells (ADSCs). Flow cytometry and immunohistochemistry were used for cell identification. The growth factors were applied at concentrations of 0, 1, 10, and 100 ng/ml as three groups: (1) bFGF alone, (2) EGF alone, and (3) bFGF mixed with EGF. Cell proliferation was evaluated by Cell Counting Kit-8 assays. Expression of Type I and III collagen (Col-I and Col-III) mRNAs was evaluated by real-time quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed with SPSS software and GraphPad Prism using one-way analysis of variance and multiple t-test.

Results:

ADSCs were successfully isolated from rat adipose tissue as identified by expression of typical surface markers CD29, CD44, CD90, and CD45 in flow cytometry. Fibroblasts induced from ADSC, compared with ADSCs, were with higher mRNA expression levels of Col I and Col III (F = 1.29, P = 0.0390). bFGF, EGF, and the mixture of bFGF with EGF can enhanced fibroblasts proliferation, and the concentration of 10 ng/ml of the mixture of bFGF with EGF displayed most effectively (all P < 0.05). The expression levels of Col-I and Col-III mRNAs in fibroblasts displayed significant increases in the 10 ng/ml bFGF combined with EGF group (all P < 0.05).

Conclusions:

The optimal concentration of both bFGF and EGF to promote cell proliferation and collagen expression in fibroblasts was 10 ng/ml at which fibroblasts grew faster and secreted more Type I and III collagens into the extracellular matrix, which might contribute to the stability of the pelvic floor microenvironment.

Crude protein from spirulina increases the viability of CCD‑986sk cells via the EGFR/MAPK signaling pathway

Spirulina, an edible blue-green alga, has great potential for various applications in human health, possibly including reduced skin aging. The mechanisms by which spirulina crude protein (SPCP) may influence human skin fibroblast viability are not yet understood; therefore, a human dermal fibroblast cell line (CCD-986sk) was used as a cell model system to study the influence of SPCP on human skin fibroblast viability. An enzyme-linked immunosorbent assay showed that collagen formation improved in SPCP-treated cells in a dose-dependent manner, while elastase activity was decreased. In addition, western blot analysis showed a dose-dependent decrease in the expression of the aging-associated gene matrix metalloproteinase-8, a collagen-degradative enzyme. It was also shown that SPCP upregulated epidermal growth factor receptor (EGFR) activity, leading to activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. Together, these results demonstrated that SPCP increases human fibroblast viability by activation of the EGFR/MAPK signaling pathway. This contribution sheds light on the molecular mechanism for SPCP increasing the viability of human skin cell and provides a potential efficient cosmeceutical for protecting human skin.

Utility of the Teslar Facial Massager for Skin Elasticity and the Mechanism of its Effects

The Teslar is a facial massager that emits a weak electric current, where users have reported a beneficial effect on skin elasticity with continued use. Accordingly, we conducted a clinical utility study and a comprehensive gene analysis, with cultured human fibroblasts to investigate the utility and mechanism of this treatment. In this clinical utility study, we found significant improvement in skin elasticity in Teslar treatments, compared to controls after two weeks of treatment. In cell experiments, we found that adenosine triphosphate synthesis and collagen contraction were promoted in fibroblasts cultured in type I collagen gel, following Teslar treatment. We considered that Teslar treatment exerted a structurally regenerative effect on the dermal matrix, based on the results of GeneChip® Expression Analysis. In particular, we demonstrated that Teslar treatment promotes type I collagen mRNA expression and fibulin-5/DANCE (Developmental arteries and neural crest EGF (epidermal growth factor)-like) mRNA expression and protein levels, which are reduced with aging. We also found increases in LTBP-3 (Latent TGF-β binding protein-3) and CSPG4 (Chondroitin sulfate proteoglycan 4) mRNA expression levels. Based on these results, we considered that Teslar treatment promoted dermal regeneration and recovery of skin elasticity.

Topical TWEAK Accelerates Healing of Experimental Burn Wounds in Mice

The interaction of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor inducible 14 (Fn14) participates in inflammatory responses, fibrosis, and tissue remodeling, which are central in the repair processes of wounds. Fn14 is expressed in main skin cells including dermal fibroblasts. This study was designed to explore the therapeutic effect of TWEAK on experimental burn wounds and the relevant mechanism underlying such function. Third-degree burns were introduced in two BALB/c mouse strains. Recombinant TWEAK was administrated topically, followed by the evaluation of wound areas and histologic changes. Accordingly, the downstream cytokines, inflammatory cell infiltration, and extracellular matrix synthesis were examined in lesional tissue. Moreover, the differentiation markers were analyzed in cultured human dermal fibroblasts upon TWEAK stimulation. The results showed that topical TWEAK accelerated the healing of burn wounds in wild-type mice but not in Fn14-deficient mice. TWEAK strengthened inflammatory cell infiltration, and exaggerated the production of growth factor and extracellular matrix components in wound areas of wild-type mice. Moreover, TWEAK/Fn14 activation elevated the expression of myofibroblastic differentiation markers, including alpha-smooth muscle actin and palladin, in cultured dermal fibroblasts. Therefore, topical TWEAK exhibits therapeutic effect on experimental burn wounds through favoring regional inflammation, cytokine production, and extracellular matrix synthesis. TWEAK/Fn14 activation induces the myofibroblastic differentiation of dermal fibroblasts, partially contributing to the healing of burn wounds.

CXCL10 is upregulated in synovium and cartilage following articular fracture

The objective of this study was to investigate the expression of the chemokine CXCL10 and its role in joint tissues following articular fracture. We hypothesized that CXCL10 is upregulated following articular fracture and contributes to cartilage degradation associated with post-traumatic arthritis (PTA). To evaluate CXCL10 expression following articular fracture, gene expression was quantified in synovial tissue from knee joints of C57BL/6 mice that develop PTA following articular fracture, and MRL/MpJ mice that are protected from PTA. CXCL10 protein expression was assessed in human cartilage in normal, osteoarthritic (OA), and post-traumatic tissue using immunohistochemistry. The effects of exogenous CXCL10, alone and in combination with IL-1, on porcine cartilage explants were assessed by quantifying the release of catabolic mediators. Synovial tissue gene expression of CXCL10 was upregulated by joint trauma, peaking one day in C57BL/6 mice (25-fold) versus 3 days post-fracture in MRL/MpJ mice (15-fold). CXCL10 protein in articular cartilage was most highly expressed following trauma compared with normal and OA tissue. In a dose dependent manner, exogenous CXCL10 significantly reduced total matrix metalloproteinase (MMP) and aggrecanase activity of culture media from cartilage explants. CXCL10 also trended toward a reduction in IL-1α-stimulated total MMP activity (p = 0.09) and S-GAG (p = 0.09), but not NO release. In conclusion, CXCL10 was upregulated in synovium and chondrocytes following trauma. However, exogenous CXCL10 did not induce a catabolic response in cartilage. CXCL10 may play a role in modulating the chondrocyte response to inflammatory stimuli associated with joint injury and the progression of PTA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1220-1227, 2018.

Tissue Engineered Skin Substitutes

The fundamental skin role is to supply a supportive barrier to protect body against harmful agents and injuries. Three layers of skin including epidermis, dermis and hypodermis form a sophisticated tissue composed of extracellular matrix (ECM) mainly made of collagens and glycosaminoglycans (GAGs) as a scaffold, different cell types such as keratinocytes, fibroblasts and functional cells embedded in the ECM. When the skin is injured, depends on its severity, the majority of mentioned components are recruited to wound regeneration. Additionally, different growth factors like fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) are needed to orchestrated wound healing process. In case of large surface area wounds, natural wound repair seems inefficient. Inspired by nature, scientists in tissue engineering field attempt to engineered constructs mimicking natural healing process to promote skin restoration in untreatable injuries. There are three main types of commercially available engineered skin substitutes including epidermal, dermal, and dermoepidermal. Each of them could be composed of scaffold, desired cell types or growth factors. These substitutes could have autologous, allogeneic, or xenogeneic origin. Moreover, they may be cellular or acellular. They are used to accelerate wound healing and recover normal skin functions with pain relief. Although there are a wide variety of commercially available skin substitutes, almost none of them considered as an ideal equivalents required for proper wound healing.

Enrichment of endogenous fractalkine and anti-inflammatory cells via aptamer-functionalized hydrogels

Early recruitment of non-classical monocytes and their macrophage derivatives is associated with augmented tissue repair and improved integration of biomaterial constructs. A promising therapeutic approach to recruit these subpopulations is by elevating local concentrations of chemoattractants such as fractalkine (FKN, CX3CL1). However, delivering recombinant or purified proteins is not ideal due to their short half-lives, suboptimal efficacy, immunogenic potential, batch variabilities, and cost. Here we report an approach to enrich endogenous FKN, obviating the need for delivery of exogenous proteins. In this study, modified FKN-binding-aptamers are integrated with poly(ethylene glycol) diacrylate to form aptamer-functionalized hydrogels ("aptagels") that localize, dramatically enrich and passively release FKN in vitro for at least one week. Implantation in a mouse model of excisional skin injury demonstrates that aptagels enrich endogenous FKN and stimulate significant local increases in Ly6C^loCX3CR1^hi non-classical monocytes and CD206⁺ M2-like macrophages. The results demonstrate that orchestrators of inflammation can be manipulated without delivery of foreign proteins or cells and FKN-aptamer functionalized biomaterials may be a promising approach to recruit anti-inflammatory subpopulations to sites of injury. Aptagels are readily synthesized, highly customizable and could combine different aptamers to treat complex diseases in which regulation or enrichment of multiple proteins may be therapeutic.

Mechanistic understanding of nanoparticles' interactions with extracellular matrix: the cell and immune system

Extracellular matrix (ECM) is an extraordinarily complex and unique meshwork composed of structural proteins and glycosaminoglycans. The ECM provides essential physical scaffolding for the cellular constituents, as well as contributes to crucial biochemical signaling. Importantly, ECM is an indispensable part of all biological barriers and substantially modulates the interchange of the nanotechnology products through these barriers. The interactions of the ECM with nanoparticles (NPs) depend on the morphological characteristics of intercellular matrix and on the physical characteristics of the NPs and may be either deleterious or beneficial. Importantly, an altered expression of ECM molecules ultimately affects all biological processes including inflammation. This review critically discusses the specific behavior of NPs that are within the ECM domain, and passing through the biological barriers. Furthermore, regenerative and toxicological aspects of nanomaterials are debated in terms of the immune cells-NPs interactions.

[Mechanism of lipolytic and smooth effects of D980-nm laser treatment on skin tissue in rats]

Objective

To determine the efficacy of D980-nm laser in dissolving fat and renewing skin, and to explore the clinical application of D980-nm laser in reconstruction of photodamaged skin.

Methods

Eighteen 12-14 month-old male Sprague-Dawley rats, weighing 400-450 g, were randomly divided into 3 groups ( n=6). The rat skin at the left side was exposed to D980-nm laser irradiation at a density of 20 J/cm ², a power of 8 W, a pulse width of 20 ms, and a pulse frequency of 40 Hz for 1 time (group A), 2 times of 5-minute interval (group B), and 3 times of 5-minute interval (group C) as a treatment course, for 4 treatment courses with an interval of 1 week; the other side of the skin was not treated as the control groups (groups A1, B1, and C1, respectively). After 8 weeks, the skin was harvested for HE staining and immunohistochemical staining to observe the structure changes of skin, to measure the dermal thickness, to count the number of fibroblasts, and detect the expressions of transforming growth factor β ₁ (TGF-β ₁) and basic fibroblast growth factor (bFGF).

Results

Compared with groups A1, B1, and C1, the skin structure was significantly improved in groups A, B, and C. After D980-nm laser irradiation, the number of fat cells decreased; local angiogenesis was observed; the total number of fibroblasts and fibers increased; the collagen fiber had large diameter, and arranged closely and regularly; the dermal thickness and the number of the fibroblasts increased; and the expressions of TGF-β ₁ and bFGF were significantly enhanced, showing significant differences ( P<0.05). With increased D980-nm laser irradiation times, the above indexes increased, showing significant differences between group C and groups A, B ( P<0.05).

Conclusion

D980-nm laser treatment has lipolytic and tender effect on the skin, and the frequency of the treatment is an important factor in skin renewal.

Mesenchymal Stem Cells from Adipose Tissue in Clinical Applications for Dermatological Indications and Skin Aging

Operating at multiple levels of control, mesenchymal stem cells from adipose tissue (ADSCs) communicate with organ systems to adjust immune response, provide signals for differentiation, migration, enzymatic reactions, and to equilibrate the regenerative demands of balanced tissue homeostasis. The identification of the mechanisms by which ADSCs accomplish these functions for dermatological rejuvenation and wound healing has great potential to identify novel targets for the treatment of disorders and combat aging. Herein, we review new insights into the role of adipose-derived stem cells in the maintenance of dermal and epidermal homeostasis, and recent advances in clinical applications of ADSCs related to dermatology.

Site-specific fibroblasts regulate site-specific inflammatory niche formation in gastric cancer

BACKGROUND

Fibroblasts are the commonest type of cancer stromal cells. Inflammation occurs in cancer tissue, and the inflammatory process has been suggested to be caused by interactions between immune cells and cancer cells. In this study, we clarified that site-specific fibroblasts regulate the formation of a site-specific inflammatory niche according to the depth of gastric cancer cell invasion.

METHODS

Immunohistochemistry was performed with paraffin-embedded tissues. The numbers of immune cells and the fibroblast area were calculated according to the cancer depth. The gene expression patterns of submucosal fibroblasts and subperitoneal fibroblasts stimulated with HSC44PE-conditioned medium were analyzed with a microarray. To examine the effects on the cancer microenvironment of differences in gene expressions between HSC44PE-stimulated submucosal fibroblasts and subperitoneal fibroblasts, assays of HSC44PE proliferation, T cell migration, and M2-like macrophage differentiation were performed.

RESULTS

The distributions of immune cells differed between the submucosal layer and the subserosal layer. The number of M2 macrophages was significantly higher and the fibroblast area was significantly larger in the subserosal layer compared with the submucosal layer. High expression levels of IL1B, TNFSF15, and CCL13 were observed in HSC44PE-stimulated submucosal fibroblasts, and higher expression levels of TGFB2, CSF1, CCL8, and CXCL5 were found in HSC44PE-stimulated subperitoneal fibroblasts. HSC44PE-stimulated subperitoneal fibroblast medium promoted the differentiation of monocytes into M2-like macrophages, whereas HSC44PE-stimulated submucosal fibroblasts significantly induced the migration of Jurkat cells and the growth of HSC44PE cells.

CONCLUSION

The dynamic states of immune cells differ between the submucosal and subserosal layers in cancer tissues. Site-specific fibroblasts regulate site-specific inflammatory niche formation according to the depth of cancer cell invasion.

Methodologies in creating skin substitutes

The creation of skin substitutes has significantly decreased morbidity and mortality of skin wounds. Although there are still a number of disadvantages of currently available skin substitutes, there has been a significant decline in research advances over the past several years in improving these skin substitutes. Clinically most skin substitutes used are acellular and do not use growth factors to assist wound healing, key areas of potential in this field of research. This article discusses the five necessary attributes of an ideal skin substitute. It comprehensively discusses the three major basic components of currently available skin substitutes: scaffold materials, growth factors, and cells, comparing and contrasting what has been used so far. It then examines a variety of techniques in how to incorporate these basic components together to act as a guide for further research in the field to create cellular skin substitutes with better clinical results.

Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts

To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

mTOR inhibition by rapamycin increases ceramide synthesis by promoting transforming growth factor-β1/Smad signaling in the skin

Although mammalian target of rapamycin (mTOR) mediates a wide variety of biological functions, little information is available on the effect of mTOR on the functions of skin cells. In this study, we investigated effects of mTOR inhibition by rapamycin on ceramide synthesis in the skin of rats and human keratinocytes and its regulatory mechanisms. The phosphorylation of p70 S6 kinase, which indicates mTOR activation, was induced in the skin of rats fed a high-fat diet, but this abnormality was reversed by supplementation with rapamycin. Ceramide levels and the mRNA levels of serine palmitoyltransferase (SPT) and transforming growth factor (TGF)-β1 were suppressed in the skin of rats fed high-fat diets, but this abnormality was reversed by supplementation with rapamycin. TGF-β1-induced SPT mRNA expression was blocked by SB525334, an inhibitor of TGF-β1-induced Smad2/3 nuclear localization, in human keratinocytes. Rapamycin-induced SPT mRNA expression was blocked by an anti-TGF-β1 antibody or SB525334 in human keratinocytes. These results show that mTOR inhibition by rapamycin increases ceramide synthesis by promoting TGF-β1/Smad signaling in the skin.

Exercise-stimulated interleukin-15 is controlled by AMPK and regulates skin metabolism and aging

Aging is commonly associated with a structural deterioration of skin that compromises its barrier function, healing, and susceptibility to disease. Several lines of evidence show that these changes are driven largely by impaired tissue mitochondrial metabolism. While exercise is associated with numerous health benefits, there is no evidence that it affects skin tissue or that endocrine muscle-to-skin signaling occurs. We demonstrate that endurance exercise attenuates age-associated changes to skin in humans and mice and identify exercise-induced IL-15 as a novel regulator of mitochondrial function in aging skin. We show that exercise controls IL-15 expression in part through skeletal muscle AMP-activated protein kinase (AMPK), a central regulator of metabolism, and that the elimination of muscle AMPK causes a deterioration of skin structure. Finally, we establish that daily IL-15 therapy mimics some of the anti-aging effects of exercise on muscle and skin in mice. Thus, we elucidate a mechanism by which exercise confers health benefits to skin and suggest that low-dose IL-15 therapy may prove to be a beneficial strategy to attenuate skin aging.

The anti-fibrotic effect of inhibition of TGFβ-ALK5 signalling in experimental pulmonary fibrosis in mice is attenuated in the presence of concurrent γ-herpesvirus infection

TGFβ-ALK5 pro-fibrotic signalling and herpesvirus infections have been implicated in the pathogenesis and exacerbation of pulmonary fibrosis. In this study we addressed the role of TGFβ-ALK5 signalling during the progression of fibrosis in a two-hit mouse model of murine γ-herpesvirus 68 (MHV-68) infection on the background of pre-existing bleomycin-induced pulmonary fibrosis. Assessment of total lung collagen levels in combination with ex vivo micro-computed tomography (µCT) analysis of whole lungs demonstrated that MHV-68 infection did not enhance lung collagen deposition in this two-hit model but led to a persistent and exacerbated inflammatory response. Moreover, µCT reconstruction and analysis of the two-hit model revealed distinguishing features of diffuse ground-glass opacities and consolidation superimposed on pre-existing fibrosis that were reminiscent of those observed in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF). Virally-infected murine fibrotic lungs further displayed evidence of extensive inflammatory cell infiltration and increased levels of CCL2, TNFα, IL-1β and IL-10. Blockade of TGFβ-ALK5 signalling attenuated lung collagen accumulation in bleomycin-alone injured mice, but this anti-fibrotic effect was reduced in the presence of concomitant viral infection. In contrast, inhibition of TGFβ-ALK5 signalling in virally-infected fibrotic lungs was associated with reduced inflammatory cell aggregates and increased levels of the antiviral cytokine IFNγ. These data reveal newly identified intricacies for the TGFβ-ALK5 signalling axis in experimental lung fibrosis, with different outcomes in response to ALK5 inhibition depending on the presence of viral infection. These findings raise important considerations for the targeting of TGFβ signalling responses in the context of pulmonary fibrosis.

The Dishevelled-binding protein CXXC5 negatively regulates cutaneous wound healing

In human melanoma biopsies and a murine cutaneous wound model, Lee et al. identify the Dishevelled-binding protein CXXC5 as a negative modulator of skin wound healing. CXXC5-deficient mice present accelerated wound healing as well as keratin and collagen synthesis. CXXC5, interacting with Dvl, operates as a negative feedback regulator of Wnt/β-catenin signaling and may represent a potential target for wound treatment.

Wnt/β-catenin signaling plays important roles in cutaneous wound healing and dermal fibrosis. However, its regulatory mechanism has not been fully elucidated, and a commercially available wound-healing agent targeting this pathway is desirable but currently unavailable. We found that CXXC-type zinc finger protein 5 (CXXC5) serves as a negative feedback regulator of the Wnt/β-catenin pathway by interacting with the Dishevelled (Dvl) protein. In humans, CXXC5 protein levels were reduced in epidermal keratinocytes and dermal fibroblasts of acute wounds. A differential regulation of β-catenin, α-smooth muscle actin (α-SMA), and collagen I by overexpression and silencing of CXXC5 in vitro indicated a critical role for this factor in myofibroblast differentiation and collagen production. In addition, CXXC5^−/− mice exhibited accelerated cutaneous wound healing, as well as enhanced keratin 14 and collagen synthesis. Protein transduction domain (PTD)–Dvl-binding motif (DBM), a competitor peptide blocking CXXC5-Dvl interactions, disrupted this negative feedback loop and activated β-catenin and collagen production in vitro. Co-treatment of skin wounds with PTD-DBM and valproic acid (VPA), a glycogen synthase kinase 3β (GSK3β) inhibitor which activates the Wnt/β-catenin pathway, synergistically accelerated cutaneous wound healing in mice. Together, these data suggest that CXXC5 would represent a potential target for future therapies aimed at improving wound healing.

Age-dependent variation in cytokines, chemokines, and biologic analytes rinsed from the surface of healthy human skin

In the skin, aging is associated with overall epidermal thinning, decreased barrier function, and gradual deterioration of the epidermal immune response. However, the presence and role of cytokines, chemokines, and biologic analytes (CCBAs) in immunosenescence are not known. Here we identified age-related changes in skin properties and CCBAs from stratum corneum of healthy human subjects, providing a means to utilize CCBAs as benchmarks for aging skin health. Transepidermal water loss and a(*) (skin redness) decreased in an age-dependent manner, and were significantly lower (p < 0.05) in Groups 2 (56.6 ± 4.6 years) and 3 (72.9 ± 3.0 years) vs. Group 1 (24.3 ± 2.8 years). In skin wash fluid, 48 CCBAs were detected; seven were significantly lower (p < 0.05) in Groups 2 and 3: EGF, FGF-2, IFNα2, IL-1RA, HSA, keratin-6, and involucrin; cortisol was significantly higher (p < 0.05) in Groups 2 and 3. Our results correspond with the pro-inflammatory shift that occurs with immunosenescence and also provides basis for understanding the inflammatory changes in normal aging skin.

Response of endothelial cells and pericytes to hypoxia and erythropoietin in a co-culture assay dedicated to soft tissue repair

The increasing mean life expectancy of the citizens of the western world countries leads to an increase of the age-related diseases, among them soft tissue defects exhibiting inadequate healing. In order to develop new therapeutic strategies to support disturbed soft tissue repair, there is a strong need of sophisticated in vitro assays. A new assay combining scratch wounding with co-cultures of primary human microvascular endothelial cells (HDMEC) and pericytes (HPC) focuses on basic characteristics of cell interaction against the background of soft tissue repair. The cell parameters proliferation, migration and differentiation, and the release of monocyte chemoattractant protein-1 (MCP-1) were analysed in response to hypoxia (pO2 < 5 mmHg) and to erythropoietin (EPO; 50 IU/ml), a glycoprotein hormone having shown promising effects in soft tissue repair. As basic characteristics of the assay, direct cell contact in co-culture led to a weakened proliferation of both cell types, an increase of the percentage of myofibroblast-like pericytes and to a higher release of MCP-1. Hypoxia caused a proliferation decrease of HPC in co-culture, which was slightly attenuated by EPO. Hypoxia also reduced the MCP-1 release of co-cultured cells, when EPO had been added. In addition, EPO had a rather positive effect on HPC migration under hypoxia. These in vitro results allow new insights into the interaction of pericytes with endothelial cells in the context of soft tissue repair.