Tumor necrosis factor-α-accelerated degradation of type I collagen in human skin is associated with elevated matrix metalloproteinase (MMP)-1 and MMP-3 ex vivo

A lysyl oxidase-responsive collagen peptide illuminates collagen remodeling in wound healing

Tissue repair and fibrosis involve the dynamic remodeling of collagen, and accurate detection of these sites is of utmost importance. Here, we use a collagen peptide sensor (1) to visualize collagen formation and remodeling during wound healing in mice and humans. We show that the probe binds selectively to sites of collagen formation and remodeling at different stages of healing. Compared to conventional methods, the peptide sensor localizes preferentially to areas of collagen synthesis and remodeling at the wound edge and not in matured fibrillar collagen. We also demonstrate its applicability for in vivo wound imaging and for discerning differential remodeling in wounds of transgenic mice with altered collagen dynamics. Our findings show the value of 1 as a diagnostic tool to rapidly identify the sites of matrix remodeling in tissue sections, which will aid in the conception of new therapeutic strategies for fibrotic disorders and defective tissue repair.

Microplastic-induced inhibition of cell adhesion and toxicity evaluation using human dermal fibroblast-derived spheroids

Nanoplastics and microplastics (MPs) can significantly affect marine ecosystems and pose potential risks to human health. Although adverse effects stemming from direct exposure to MPs have been demonstrated at the cellular level in animal models, the potential toxicity of these materials in the human body remains uncertain. In this study, we investigated the three-dimensional (3D) behavior of dermal-derived cells exposed to MPs using artificially manufactured spherical primary polystyrene (PS) particles. To explore these effects, we used cellular spheroids as a 3D cell culture model, examined the size-dependent penetration of PS-MPs, and observed morphological alterations in the spheroids. Furthermore, we assessed changes in physiological activities, including reactive oxygen species, adenosine triphosphate, and lactate dehydrogenase, to elucidate the potential intra- and extracellular toxic reactions to PS-MPs. Additionally, our examination of cell-cell junctions and the extracellular matrix (ECM), along with analysis of the regulators involved in their decreased integrity, revealed negatively influenced changes in expression. This exposure study using spheroid models provides new insights into the potential toxicity of short-term exposure to MPs under conditions that closely resemble in vivo systems.

Inhibitory effects of bioactive compounds on UVB-induced photodamage in human keratinocytes: modulation of MMP1 and Wnt signaling pathways

UVB radiation significantly threatens skin health, contributing to wrinkle formation and an elevated risk of skin cancer. This study aimed to explore bioactive compounds with potential UVB-protective properties. Using in silico analysis, we chose compounds to reduce binding energy with matrix metalloproteinase-1 (MMP1). Piperitoside, procyanidin C1, and mulberrofuran E emerged as promising candidates through this computational screening process. We investigated the UVB-protective efficacy of the selected compounds and underlying mechanisms in human immortalized keratinocytes (HaCaT). We also investigated the molecular pathways implicated in their action, focusing on the transforming growth factor (TGF)-β and wingless-related integration site (Wnt)/β-catenin signaling pathways. In UVB-exposed HaCaT cells (100 mJ/cm2 for 30 min), piperitoside, procyanidin C1, and mulberrofuran E significantly reduced reactive oxygen species (ROS) and lipid peroxides, coupled with an augmentation of collagen expression. These compounds suppressed MMP1, tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS) expression, while they concurrently enhanced collagen-1 (COL1A1), β-catenin (CTNNB1), and superoxide dismutase type-1 (SOD1) expression. Furthermore, Wnt/β-catenin inhibitors, when administered subsequently, partially counteracted the reduction in MMP1 expression and alleviated inflammatory and oxidative stress markers induced by the bioactive compounds. In conclusion, piperitoside, procyanidin C1, and mulberrofuran E protected against UVB-induced damage in HaCaT cells by inhibiting MMP1 expression and elevating β-catenin expression. Consequently, these bioactive compounds emerge as promising preventive agents for UVB-induced skin damage, promoting skin health.

Role of collagen and immunostaining for TGF-β in the clinical and microscopic findings of pyogenic granuloma and peripheral ossifying fibroma

BACKGROUND

Collagen is a component of Pyogenic Granuloma (PG) and Peripheral Ossifying Fibroma (POF) and performs different functions in these lesions. The objective of this study is to evaluate the role of collagen and immunostaining for Transforming Growth Factor beta (TGF-β) in the clinical and microscopic findings of PG and POF.

MATERIAL AND METHODS

PG (n=20) and POF (n=20) were selected for clinical evaluation (sex, age, localization, size and evolution time) and microscopic analysis (picrosirius red staining for collagen analysis and immunohistochemistry for TGF-β) performed in the superficial and deep areas of the two lesions. ANOVA/Bonferroni and t-test, Pearson correlation and χ2 were used to compare the sites and parameters analyzed (p<0.05, GraphPad Prism 5.0).

RESULTS

The depth of PG presented the highest amount of collagen (p<0.001), and its surface showed the lowest amount of type 1 collagen (yellow-red strong birefringence). Type 1 collagen gradually increased in depth of PG, surface and depth of POF (p<0.001). The number of TGF-β+ cells was lower on the surface of PG compared with the depth of PG and the two areas of POF (p<0.001). Sex and localization did not affect these parameters, but the profile of collagen and immunostaining for TGF-β suffered from modifications by the time of evolution and the size of the lesion.

CONCLUSIONS

Although PG and POF are reactive gingival lesions, the expression of TGF-β and its role in collagen showed different biological behaviors in these lesions, suggesting different biological origins for its components.

Human Probiotic Lactobacillus paracasei-Derived Extracellular Vesicles Improve Tumor Necrosis Factor-α-Induced Inflammatory Phenotypes in Human Skin

Lactic acid bacteria (LAB), a probiotic, provide various health benefits. We recently isolated a new Lactobacillus paracasei strain with strong anti-inflammatory effects under lipopolysaccharide-induced conditions and proposed a new mode of action-augmenting the endoplasmic reticulum stress pathway for anti-inflammatory functions in host cells. The beneficial effects of the L. paracasei strains on the skin have been described; however, the effects of L. paracasei-derived extracellular vesicles (LpEVs) on the skin are poorly understood. Herein, we investigated whether LpEVs can improve inflammation-mediated skin phenotypes by determining their effects on primary human skin cells and a three-dimensional (3D) full-thickness human skin equivalent under tumor necrosis factor (TNF)-α-challenged inflammatory conditions. LpEVs were efficiently taken up by the human skin cells and were much less cytotoxic to host cells than bacterial lysates. Furthermore, low LpEV concentrations efficiently restored TNF-α-induced cellular phenotypes, resulting in increased cell proliferation and collagen synthesis, but decreased inflammatory factor levels (matrix metalloproteinase 1, interleukin 6, and interleukin 8) in the human dermal fibroblasts, which was comparable to that of retinoic acid, a representative antiaging compound. The beneficial effects of LpEVs were validated in a 3D full-thickness human skin equivalent model. LpEV treatment remarkably restored the TNF-α-induced epidermal malformation, abnormal proliferation of keratinocytes in the basal layer, and reduction in dermal collagen synthesis. Additionally, LpEVs penetrated and reached the deepest dermal layer within 24 h when overlaid on top of a 3D full-thickness human skin equivalent. Furthermore, they possessed superior antioxidant capacity compared with the human cell-derived EVs. Taken together, the anti-inflammatory probiotic LpEVs can be attractive antiaging and antioxidant substances for improving inflammation-induced skin phenotypes and disorders.

Emergence of New Concepts in Skin Physiopathology through the Use of in vitro Human Skin Explants Models

BACKGROUND

This review summarizes uses and new applications for dermatological research of in vitro culture models of human skin explants (HSEs). In the last decade, many innovations have appeared in the literature and an exponential number of studies have been recorded in various fields of application such as process culture engineering, stem cell extractions methodology, or cell-to-cell interaction studies under physiological and pathological conditions, wound-healing, and inflammation. Most studies also concerned pharmacology, cosmetology, and photobiology. However, these topics will not be considered in our review.

SUMMARY

A better understanding of the mechanisms driving intercellular relationships, at work in the maintenance of 3D tissue architectures has led to the improvement of cell culture techniques. Many papers have focused on the physiological ways that govern in vitro tissue maintenance of HSEs. The analysis of the necessary mechanical stress, intercellular and cell-matrix interactions, allows the maintenance and prolonged use of HSEs in culture for up to 15 days, regardless of the great variability of study protocols from one laboratory to another and in accordance with the objectives set. Because of their close similarities to fresh skin, HSEs are increasingly used to study skin barrier repair and wound healing physiology. Easy to use in co-culture, this model allows a better understanding of the connections and interactions between the peripheral nervous system, the skin and the immune system. The development of the concept of an integrated neuro-immuno-cutaneous system at work in skin physiology and pathology highlighted by this article represents one of the new technical challenges in the field of in vitro culture of HSE. This review of the literature also reveals the importance of using such models in pathology. As sources of stem cells, HSEs are the basis for the development of new tissue engineering models such as organoids or optical clearing tissues technology. This study identifies the main advances and cross-cutting issues in the use of HSE.

Immunomodulatory Nanosystems: Advanced Delivery Tools for Treating Chronic Wounds

The increasingly aging society led to a rise in the prevalence of chronic wounds (CWs), posing a significant burden to public health on a global scale. One of the key features of CWs is the presence of a maladjusted immune microenvironment characterized by persistent and excessive (hyper)inflammation. A variety of immunomodulatory therapies have been proposed to address this condition. Yet, to date, current delivery systems for immunomodulatory therapy remain inadequate and lack efficiency. This highlights the need for new therapeutic delivery systems, such as nanosystems, to manage the pathological inflammatory imbalance and, ultimately, improve the treatment outcomes of CWs. While a plethora of immunomodulatory nanosystems modifying the immune microenvironment of CWs have shown promising therapeutic effects, the literature on the intersection of immunomodulatory nanosystems and CWs remains relatively scarce. Therefore, this review aims to provide a comprehensive overview of the pathogenesis and characteristics of the immune microenvironment in CWs, discuss important advancements in our understanding of CW healing, and delineate the versatility and applicability of immunomodulatory nanosystems-based therapies in the therapeutic management of CWs. In addition, we herein also shed light on the main challenges and future perspectives in this rapidly evolving research field.

Effects of Bacterial Lysates and Metabolites on Collagen Homeostasis in TNF-α-Challenged Human Dermal Fibroblasts

During skin aging, the production of extracellular matrix (ECM) proteins, such as type I collagen, decreases and the synthesis of ECM-degrading matrix metalloproteinases (MMPs) rises, leading to an imbalance in homeostasis and to wrinkle formation. In this study, we examined the effects of bacterial lysates and metabolites from three bifidobacteria and five lactobacilli on collagen homeostasis in human dermal fibroblasts during challenge with tumor necrosis factor alpha (TNF-α), modeling an inflammatory condition that damages the skin's structure. Antiaging properties were measured, based on fibroblast cell viability and confluence, amount of type I pro-collagen, ratio of MMP-1 to type I pro-collagen, cytokines, and growth factors. The TNF-α challenge increased the MMP-1/type I pro-collagen ratio and levels of proinflammatory cytokines, as expected. With the probiotics, differences were clearly dependent on bacterial species, strain, and form. In general, the lysates elicited less pronounced responses in the biomarkers. Of all strains, the Bifidobacterium animalis ssp. lactis strains Bl-04 and B420 best maintained type I pro-collagen production and the MMP-1/collagen type I ratio under no-challenge and challenge conditions. Metabolites that were produced by bifidobacteria, but not their lysates, reduced several proinflammatory cytokines (IL-6, IL-8, and TNF-α) during the challenge, whereas those from lactobacilli did not. These results indicate that B. animalis ssp. lactis-produced metabolites, especially those of strains Bl-04 and B420, could support collagen homeostasis in the skin.

Development on potential skin anti-aging agents of Cosmos caudatus Kunth via inhibition of collagenase, MMP-1 and MMP-3 activities

BACKGROUND

Skin aging is associated with degradation of collagen by matrix metalloproteinases (MMPs), which leads to loss of skin elasticity and formation of wrinkles. Cosmos caudatus Kunth (CC) has been traditionally claimed as an anti-aging agent in Malaysia. Despite its well-known antioxidant activity, the anti-aging properties of CC was not validated.

PURPOSE

This study aimed to investigate the anti-aging potential of CC extracts and fractions, particularly their inhibition of collagenase, MMP-1 and MMP-3 activities in human dermal fibroblasts CCD-966SK, followed by isolation, identification and analysis of their bioactive constituents.

STUDY DESIGN AND METHODS

DPPH assay was firstly used to evaluate the antioxidant activity throughout the bioactivity-guided fractionation. Cell viability was determined using MTS assay. Collagenase activity was examined, while MMP-1 and MMP-3 expression were measured using qRT-PCR and western blotting. Then, chemical identification of pure compounds isolated from CC fractions was done by using ESIMS, ¹H and ¹³C NMR spectroscopies. HPLC analyses were carried out for bioactive fractions to quantify the major components.

RESULTS

Throughout the antioxidant activity-guided fractionation, fractions CC-E2 and CC-E3 with antioxidant activity and no toxicity towards CCD-966SK cells were obtained from CC 75% ethanol partitioned layer (CC-E). Both fractions inhibited collagenase activity, MMP-1 and MMP-3 mRNA and protein expression, as well as NF-κB activation induced by TNF-α in CCD-966SK cells. 14 compounds, which mainly consists of flavonoids and their glycosides, were isolated. Quercitrin (14.79% w/w) and quercetin (11.20% w/w) were major compounds in CC-E2 and CC-E3, respectively, as quantified by HPLC. Interestingly, both fractions also inhibited the MMP-3 protein expression synergistically, compared with treatment alone.

CONCLUSION

The quantified CC fractions rich in flavonoid glycosides exhibited skin anti-aging effects via the inhibition of collagenase, MMP-1 and MMP-3 activities, probably through NF-κB pathway. This is the first study reported on MMP-1 and MMP-3 inhibitory activity of CC with its chemical profile, which revealed its potential to be developed as anti-aging products in the future.

Evaluating the Degradation Process of Collagen Sponge and Acellular Matrix Implants In Vivo Using the Standardized HPLC-MS/MS Method

The purpose of this study was to establish a collagen determination method based on an isotope-labeled collagen peptide as an internal reference via high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS), and using the established method to evaluate the degradation process of collagen-based implants in vivo. The specific peptide (GPAGPQGPR) of bovine type I collagen was identified with an Orbitrap mass spectrometer. Then, the quantification method based on the peptide detection with HPLC-MS/MS was established and validated, and then further used to analyze the degradation trend of the collagen sponge and acellular matrix (ACM) in vivo at 2, 4, 6, 8, 12, 16, and 18 weeks after implantation. The results indicate that the relative standard deviation (RSD) of the detection precision and repeatability of the peptide-based HPLC-MS/MS quantification method were 3.55% and 0.63%, respectively. The limitations of quantification and detection were 2.05 × 10−3 μg/mL and 1.12 × 10−3 μg/mL, respectively. The collagen sponge and ACM were completely degraded at 10 weeks and 18 weeks, respectively. Conclusion: A specific peptide (GPAGPQGPR) of bovine type I collagen was identified with an Orbitrap mass spectrometer, and a standardized HPLC-MS/MS-based internal reference method for the quantification of bovine type I collagen was established. The method can be used for the analysis of the degradation of collagen-based implants in vivo.

Gene Expression Linked to Reepithelialization of Human Skin Wounds

Our understanding of the regulatory processes of reepithelialization during wound healing is incomplete. In an attempt to map the genes involved in epidermal regeneration and differentiation, we measured gene expression in formalin-fixed, paraffin-embedded standardized epidermal wounds induced by the suction-blister technique with associated nonwounded skin using NanoString technology. The transcripts of 139 selected genes involved in clotting, immune response to tissue injury, signaling pathways, cell adhesion and proliferation, extracellular matrix remodeling, zinc transport and keratinocyte differentiation were evaluated. We identified 22 upregulated differentially expressed genes (DEGs) in descending order of fold change (MMP1, MMP3, IL6, CXCL8, SERPINE1, IL1B, PTGS2, HBEGF, CXCL5, CXCL2, TIMP1, CYR61, CXCL1, MMP12, MMP9, HGF, CTGF, ITGB3, MT2A, FGF7, COL4A1 and PLAUR). The expression of the most upregulated gene, MMP1, correlated strongly with MMP3 followed by IL6 and IL1B. rhIL-1β, but not rhIL-6, exposure of cultured normal human epidermal keratinocytes and normal human dermal fibroblasts increased both MMP1 mRNA and MMP-1 protein levels, as well as TIMP1 mRNA levels. The increased TIMP1 in wounds was validated by immunohistochemistry. The six downregulated DEGs (COL7A1, MMP28, SLC39A2, FLG1, KRT10 and FLG2) were associated with epidermal maturation. KLK8 showed the strongest correlation with MKI67 mRNA levels and is a potential biomarker for keratinocyte proliferation. The observed gene expression changes correlate well with the current knowledge of physiological reepithelialization. Thus, the gene expression panel described in this paper could be used in patients with impaired healing to identify possible therapeutic targets.

Downregulation of senescence-associated secretory phenotype by knockdown of secreted frizzled-related protein 4 contributes to the prevention of skin aging

There is growing evidence that the appearance and texture of the skin that is altered during the aging process are considerably enhanced by the accumulation of senescent dermal fibroblasts. These senescent cells magnify aging via an inflammatory, histolytic, and senescence-associated secretory phenotype (SASP). Secreted frizzled-related protein 4 (SFRP4) was previously determined to be expressed in dermal fibroblasts of aging skin, and its increased expression has been shown to promote cellular senescence. However, its role in the SASP remains unknown. We found that SFRP4 was significantly expressed in p16ink4a-positive human skin fibroblasts and that treatment with recombinant SFRP4 promoted SASP and senescence, whereas siRNA knockdown of SFRP4 suppressed SASP. Furthermore, we found that knockdown of SFRP4 in mouse skin ameliorates age-related reduction of subcutaneous adipose tissue, panniculus carnosus muscle layer, and thinning and dispersion of collagen fibers. These findings suggest a potential candidate for the development of new skin rejuvenation therapies that suppress SASP.

Chitosan-G-Glycidyl Methacrylate/Au Nanocomposites Promote Accelerated Skin Wound Healing

Herein, we report the synthesis of Au nanoparticles (AuNPs) in chitosan (CTS) solution by chemically reducing HAuCl₄. CTS was further functionalized with glycidyl methacrylate (chitosan-g-glycidyl methacrylate/AuNP, CTS-g-GMA/AuNP) to improve the mechanical properties for cellular regeneration requirements of CTS-g-GMA/AuNP. Our nanocomposites promote excellent cellular viability and have a positive effect on cytokine regulation in the inflammatory and anti-inflammatory response of skin cells. After 40 days of nanocomposite exposure to a skin wound, we showed that our films have a greater skin wound healing capacity than a commercial film (TheraForm^®), and the presence of the collagen allows better cosmetic ave aspects in skin regeneration in comparison with a nanocomposite with an absence of this protein. Electrical percolation phenomena in such nanocomposites were used as guiding tools for the best nanocomposite performance. Our results suggest that chitosan-based Au nanocomposites show great potential for skin wound repair.

Effects of Collagen-Tripeptide and Galacto-oligosaccharide Mixture on Skin Photoaging Inhibition in UVB-exposed Hairless Mice

Collagen-tripeptide (CTP) and galacto-oligosaccharide (GOS), which improve collagen homeostasis and barrier function in the skin, are widely used in the food industry to improve wrinkle-related parameters and skin health. In this study, the photoprotective effect of CTP/GOS mixtures (3:1, 1:1, and 1:3) in ultraviolet (UV) B-irradiated hairless mice was examined. Skin parameter analysis, histological approaches, molecular biology techniques and HPLC analysis were applied to investigate the photoaging protective effect, signaling pathways and changes in the microbiota. Oral administration of CTP/GOS mixtures ameliorated photoaged physical parameters and serum levels of pro-inflammatory cytokines compared to UV-irradiated control group. Administration of the 1:3 mixture showed significant changes in the extracellular matrix-related gene expression compared to other mixture groups. The cecal short-chain fatty acid (SCFA) content showed a significant increase in the CTP/GOS mixed group with a higher GOS content than the control group. In the 16S rRNA-based analysis of cecal microbiota, the relative abundance ratio of the Akkermansia genus belonging to the Verrucomicrobia phylum was higher in CTP and GOS mixture-administered groups than in the UV-irradiated control group. Taken together, CTP/GOS mixtures showed a synergistic effect on photoprotective activity through changes in the gene expression, cytokine levels and intestinal microbiota composition.

Characterization of a Cutibacterium acnes Camp Factor 1-Related Peptide as a New TLR-2 Modulator in In Vitro and Ex Vivo Models of Inflammation

Cutibacterium acnes (C. acnes) has been implicated in inflammatory acne where highly mutated Christie-Atkins-Munch-Petersen factor (CAMP)1 displays strong toll like receptor (TLR)-2 binding activity. Using specific antibodies, we showed that CAMP1 production was independent of C. acnes phylotype and involved in the induction of inflammation. We confirmed that TLR-2 bound both mutated and non-mutated recombinant CAMP1, and peptide array analysis showed that seven peptides (A14, A15, B1, B2, B3, C1 and C3) were involved in TLR-2 binding, located on the same side of the three-dimensional structure of CAMP1. Both mutated and non-mutated recombinant CAMP1 proteins induced the production of C-X-C motif chemokine ligand interleukin (CXCL)8/(IL)-8 in vitro in keratinocytes and that of granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor (TNF)-α, IL-1β and IL-10 in ex vivo human skin explants. Only A14, B1 and B2 inhibited the production of CXCL8/IL-8 by keratinocytes and that of (GM-CSF), TNF-α, IL-1β and IL-10 in human skin explants stimulated with rCAMP1 and C. acnes. Following pretreatment with B2, RNA sequencing on skin explants identified the 10 genes displaying the strongest differential expression as IL6, TNF, CXCL1, CXCL2, CXCL3, CXCL8, IL-1β, chemokine ligand (CCL)2, CCL4 and colony stimulating factor (CSF)2. We, thus, identified a new CAMP1-derived peptide as a TLR-2 modulator likely to be a good candidate for clinical evaluation.

The role of extracellular matrix on unfavorable maternal–fetal interface: focusing on the function of collagen in human fertility

Extracellular matrix (ECM) is characterized as widespread, abundant, and pluripotent. Among ECM members, collagen is widely accepted as one of the most prominent components for its essential structural property that can provide a scaffold for other components of ECM and the rich biological functions, which has been extensively used in tissue engineering. Emerging evidence has shown that the balance of ECM degradation and remodeling is vital to regulations of maternal–fetal interface including menstrual cycling, decidualization, embryo implantation and pregnancy maintenance. Moreover, disorders in these events may eventually lead to failure of pregnancy. Although the improvement of assisted conception and embryo culture technologies bring hope to many infertile couples, some unfavorable outcomes, such as recurrent implantation failure (RIF), recurrent pregnancy loss (RPL) or recurrent miscarriage (RM), keep troubling the clinicians and patients. Recently, in vitro three-dimensional (3D) model mimicking the microenvironment of the maternal–fetal interface is developed to investigate the physiological and pathological conditions of conception and pregnancy. The progress of this technology is based on clarifying the role of ECM in the endometrium and the interaction between endometrium and conceptus. Focusing on collagen, the present review summarized the degradation and regulation of ECM and its role in normal menstruation, endometrium receptivity and unsatisfying events occurring in infertility treatments, as well as the application in therapeutic approaches to improve pregnancy outcomes. More investigations about ECM focusing on the maternal–fetal interface interaction with mesenchymal stem cells or local immunoregulation may inspire new thoughts and advancements in the clinical application of infertility treatments.

Graphical abstract

Improvement of Damage in Human Dermal Fibroblasts by 3,5,7-Trimethoxyflavone from Black Ginger (Kaempferia parviflora)

Reactive oxygen species (ROS) are generated during intrinsic (chronological aging) and extrinsic (photoaging) skin aging. Therefore, antioxidants that inhibit ROS production may be involved in delaying skin aging. In this study, we investigated the potential effects of compounds isolated from black ginger, Kaempferia parviflora, a traditional medicinal plant, on normal human dermal fibroblasts in the context of inflammation and oxidative stress. The isolated compounds were structurally characterized as 5-hydroxy-7-methoxyflavone (1), 3,7-dimethoxy-5-hydroxyflavone (2), 5-hydroxy-3,7,3,4-tetramethoxyflavone (3), 7,4-dimethylapigenin (4), 3,7,4-trimethylkaempferol (5), and 3,5,7-trimethoxyflavone (6), using nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography–mass spectrometry (LC/MS) analyses. These flavonoids were first evaluated for their ability to suppress extracellular matrix degradation in normal human dermal fibroblasts. Of these, 3,5,7-trimethoxyflavone (6) significantly inhibited the tumor necrosis factor (TNF)-α-induced high expression and secretion of matrix metalloproteinase (MMP)-1 by cells. We further found that 3,5,7-trimethoxyflavone suppressed the excessive increase in ROS, mitogen-activated protein kinases (MAPKs), Akt, and cyclooxygenase-2 (COX-2)and increased heme oxygenase (HO)-1 expression. The expression of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, and IL-8, was also suppressed by 3,5,7-trimethoxyflavone (6). Taken together, our results indicate that 3,5,7-trimethoxyflavone (6) isolated from K. parviflora is a potential candidate for ameliorating skin damage.

Immune Regulation of Mammary Fibroblasts and the Impact of Mammographic Density

Mammographic density is associated with a 4–6-fold increase in breast cancer risk independent of age and BMI. High mammographic density is characterized by breast tissue with high proportions of stroma comprised of fibroblasts, collagen, and immune cells. This study sought to investigate whether stromal fibroblasts from high mammographic density breast tissue contributes to increased extracellular matrix deposition and pro-tumorigenic signaling. Mammary fibroblasts were isolated from women with high and low mammographic density and exposed to immune factors myeloperoxidase (MPO), eosinophil peroxidase (EPO), transforming growth factor beta 1 (TGFB1) and tumour necrosis factor alpha (TNFA) for 72 h and profiled for expression of cancer-associated fibroblast and extracellular matrix regulation markers. No differences in gene expression profiles or collagen production were observed between fibroblasts with high or low mammographic density, and they did not have a differential response to immune mediators. MPO and EPO significantly increased the production of collagen 1. TGFB and TNFA induced variable changes in gene expression. Fibroblasts cultured in vitro from women with high mammographic density do not appear to be inherently different to those from women with low mammographic density. The function of fibroblasts in mammographic density-associated breast cancer risk is likely to be regulated by immune signals from surrounding cells in the microenvironment.

M1 Polarized Macrophages Persist in Skin of Post-Bariatric Patients after 2 Years

BACKGROUND

Obesity is considered a condition of systemic chronic inflammation. Under this condition, adipose tissue macrophages switch from an M2 (anti-inflammatory) activation pattern to an M1 (proinflammatory) activation pattern.

OBJECTIVE

The study aimed to verify the profile of skin macrophage activation after bariatric surgery as well as the role of MMP-1 in extracellular tissue remodeling.

METHODS

This is a prospective, controlled and comparative study with 20 individuals split into two groups according to their skin condition: post-bariatric and eutrophic patients. Histological and morphometric analyses based on hematoxylin-eosin, picrosirius red (collagen), orcein (elastic fiber systems), and alcian blue (mast cells)-stained sections and immunohistochemical analysis (CD68, iNOS, and mannose receptor) for macrophages and metalloproteinase-1 were performed.

RESULTS

Post-bariatric skin showed an increase in inflammation, angiogenesis, CD68, M1 macrophages (P< 0.001), and mast cells (P< 0.01); a decrease in M2 macrophages (P< 0.01); and a significant decrease in the collagen fiber network (P< 0.001). MMP-1 was increased in the papillary dermis of post-bariatric skin and decreased in the epidermis compared to eutrophic skin (P< 0.05).

CONCLUSION

This study shows that post-bariatric skin maintains inflammatory characteristics for two years. Mast cells and M1 macrophages maintain and enhance the remodeling of the dermal extracellular matrix initiated during obesity in part due to the presence of MMP-1 in the papillary dermis.

EBM LEVEL IV

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 .

Interleukin-9 Facilitates Osteoclastogenesis in Rheumatoid Arthritis

In rheumatoid arthritis (RA), inflammatory cytokines play a pivotal role in triggering abnormal osteoclastogenesis leading to articular destruction. Recent studies have demonstrated enhanced levels of interleukin-9 (IL-9) in the serum and synovial fluid of patients with RA. In RA, strong correlation has been observed between tissue inflammation and IL-9 expression in synovial tissue. Therefore, we investigated whether IL-9 influences osteoclastogenesis in patients with RA. We conducted the study in active RA patients. For inducing osteoclast differentiation, mononuclear cells were stimulated with soluble receptor activator of NF-kB ligand (sRANKL) and macrophage-colony-stimulating factor (M-CSF) in the presence or absence of recombinant (r) IL-9. IL-9 stimulation significantly enhanced M-CSF/sRANKL-mediated osteoclast formation and function. Transcriptome analysis revealed differential gene expression induced with IL-9 stimulation in the process of osteoclast differentiation. IL-9 mainly modulates the expression of genes, which are involved in the metabolic pathway. Moreover, we observed that IL-9 modulates the expression of matrix metalloproteinases (MMPs), which are critical players in bone degradation. Our results indicate that IL-9 has the potential to influence the structural damage in the RA by promoting osteoclastogenesis and modulating the expression of MMPs. Thus, blocking IL-9 pathways might be an attractive immunotherapeutic target for preventing bone degradation in RA.

Prevention by the Natural Artocarpin of Morphological and Biochemical Alterations on UVB-Induced HaCaT Cells

Natural substances have gained considerable attention for skin protection against UV light reactions. Artocarpus altilis plant's heartwood extract is comprised of artocarpin as a major substance, already known for its interesting biological attributes as an antimicrobial, an anti-inflammatory, an antioxidant, and a melanogenesis inhibitor. The present work clarified the mechanism of natural artocarpin (NAR) with a purity of approximately 99% against the effects of UVB-induced HaCaT keratinocyte apoptosis. The indicated results showed that NAR suppresses free radical production (ROS and nitrite) and apoptosis-related molecule activation (caspase-3, p-p53, p-p38, and NF-κB p65) and secretion (TNF-α). Additionally, NAR prevented structural damages (nuclei condensation and fragmentation, apoptotic body formation, impaired cell adherence and round cell shape, disruption of F-actin filament, and clustering of cell death receptor CD95/Fas) and biophysical changes (plasma membrane rigidification). Thus, NAR acts directly from scavenging free radicals generated by UV and indirectly by suppressing morphological and biochemical UV-induced cell damages. Its biological effects are mainly attributed to antioxidant and antiapoptotic properties. Taken together, NAR could be considered as an effective natural product for photoprotective formulations.

Granulation tissue myofibroblasts during normal and pathological skin healing: The interaction between their secretome and the microenvironment

The first role that was proposed for the myofibroblasts located in skin granulation tissue was to contract the edges of the wound in order to reduce the surface to be repaired. This role, linked to the presence of alpha smooth muscle actin, was very quickly confirmed and is part of the definition of granulation tissue myofibroblasts. However, myofibroblasts are cells that also play a much more central role in wound healing. Indeed, it has been shown that these cells produce large quantities of matrix components, and that they stimulate angiogenesis and can recruit immune cells. These actions take place via the secretion of molecules into their environment or indirectly via the production of microvesicles containing pro-fibrotic and pro-angiogenic molecules. Pathologically, granulation tissue can develop into a hypertrophic scar that histologically looks like granulation tissue, but which can remain for months or even years. It has been hypothesized that the myofibroblasts in these tissues remained present instead of disappearing by apoptosis, causing the maintenance of granulation tissue rather than allowing its change into a mature scar. Understanding the roles of both pathological and healthy myofibroblasts in wound tissue is crucial in order to better intervene in the healing mechanism.

Phenotypic characterization of circulating endothelial cells induced by inflammation and oxidative stress in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic auto-immune disease, affecting the spine, sacroiliac, and sometimes peripheral joints. It is also involved with cardio-vascular risk factors due to accelerated atherosclerosis. Oxidative burst, systemic inflammation coupled with endothelial dysfunction (ED), resulting in reduced bioavailability of the vasodilator nitric oxide (NO) and an increased number of circulating endothelial cells (CECs) may correlate with disease activity and its sustenance. Hence, the study was aimed to detect and quantify CECs and assess the oxidative stress and inflammatory status in AS patients vis-à-vis healthy controls, as well as relate these parameters with AS disease activity and atherosclerotic markers in patients. Our study showed an increased frequency of endothelial cells in peripheral blood of AS patients in pro-inflammatory conditions. In AS patient population, they showed significant reduction of flow-mediated dilatation (%FMD) (p < 0.05), and increased soluble adhesion molecules such as sICAM-1 (p < 0.01) and sVCAM-1 (p < 0.05) compared to healthy controls. A marked increase in pro-inflammatory markers such as TNF-α (p < 0.01) and IL-1β (p < 0.001) and reactive free radicals (p < 0.05) along with reduced serum nitrite in AS, provided a strong pro-inflammatory milieu which positively correlated with Bath ankylosing spondylitis disease activity and functional indices (BASDAI and BASFI). The observed significant upregulation in CECs (CD45^-/CD31⁺/CD105⁺/CD144⁺) in patients compared to healthy controls positively correlated with disease activity and duration as well as with markers of oxidative stress. Thus, chronic inflammation and oxidative burst induce loss of NO bioavailability, leading to ED. This may cause the derangement of CECs that may be considered as a prognostic biomarker for ED.

Inhibition of lncRNA HOTTIP ameliorated myofibroblast activities and inflammatory cytokines in oral submucous fibrosis

BACKGROUND/PURPOSE

Long non-coding RNA HOXA transcript at the distal tip (HOTTIP) has been reported to contribute to multiple carcinomas, but whether it involves in the progression of precancerous conditions remains to be determined. Oral submucous fibrosis (OSF) has been known as an oral potentially malignant disorder and attributed to the persistent activation of the myofibroblast.

METHODS

The relative expression of HOTTIP in OSF tissues has been employed by RNA-sequencing and RT-PCR analysis. HOTTIP associated myofibroblasts activities and markers in fibrotic buccal mucosal fibroblast (fBMFs) through loss of function approaches have been evaluated.

RESULTS

In the present study, we found that the expression of HOTTIP was overexpressed in the OSF tissues and positively correlated with several fibrosis markers. To investigate its significance of myofibroblast activation, we first verified the expression level of HOTTIP in the patient-derived fibrotic buccal mucosal fibroblast (fBMFs) was upregulated and conducted the shRNA-mediated knockdown experiment to inhibit its expression followed by numerous examinations. We demonstrated that suppression of HOTTIP downregulated the expression of myofibroblast marker, α-SMA, and type I collagen along with the diminished myofibroblast activities (collagen gel contraction and migration capacities). Furthermore, we showed that silencing HOTTIP lessened the production of various pro-inflammatory cytokines (IL-6 and TNF-α).

CONCLUSION

Collectively, our results suggest that HOTTIP plays a crucial role in the persistent activation of myofibroblasts as well as the chronic inflammation and collagen deposition.

Resveratrol inhibits matrix metalloproteinase-1 and -3 expression by suppressing of p300/NFκB acetylation in TNF-α-treated human dermal fibroblasts

The aim of this study was to explore the signaling pathways associated with the effects of tumor necrosis factor alpha (TNF-α) on matrix metalloproteinase-1 (MMP-1) and MMP-3 expression in the human dermal fibroblast cell line CCD-966SK. TNF-α upregulated MMP-1 and MMP-3 mRNA and protein expression, and NFκB/p65 activation was found to be involved in TNF-α-induced MMP-1 and MMP-3 upregulation. TNF-α induced p65 phosphorylation at Ser536 and acetylation at Lys310. p300 knockdown suppressed TNF-α-induced p65 acetylation and reduced MMP-1 and MMP-3 expression in TNF-α-treated cells, but did not greatly restore MMP-1 and MMP-3 expression when p65 phosphorylation was inhibited by Bay11-7082 (IκBα inhibitor). NF-κB/luciferase reporter assay revealed that p300-mediated p65 acetylation was crucial for TNF-α-induced nuclear factor-kappa B (NF-κB) transcriptional activity. The chromatin immunoprecipitation (ChIP) assay indicated that TNF-α increased p300 recruitment to the MMP-1 and MMP-3 promoter regions surrounding the NFκB-binding site. Resveratrol notably inhibited TNF-α-induced MMP-1 and MMP-3 upregulation and abrogated TNF-α-induced p65 acetylation, leading to the downregulation of MMP-1 and MMP-3 expression in TNF-α-treated cells. Our data indicate that TNF-α-induced p300-mediated p65 acetylation leads to the upregulation of MMP-1 and MMP-3 expression in dermal fibroblasts, whereas resveratrol reduces this TNF-α-induced upregulation by downregulating p300 expression.

Dermal fibroblasts cultured from donors with type 2 diabetes mellitus retain an epigenetic memory associated with poor wound healing responses

The prevalence of Type 2 diabetes mellitus (T2DM) is escalating globally. Patients suffer from multiple complications including the development of chronic wounds that can lead to amputation. These wounds are characterised by an inflammatory environment including elevated tumour necrosis factor alpha (TNF-α). Dermal fibroblasts (DF) are critical for effective wound healing, so we sought to establish whether there were any differences in DF cultured from T2DM donors or those without diabetes (ND-DF). ND- and T2DM-DF when cultured similarly in vitro secreted comparable concentrations of TNF-α. Functionally, pre-treatment with TNF-α reduced the proliferation of ND-DF and transiently altered ND-DF morphology; however, T2DM-DF were resistant to these TNF-α induced changes. In contrast, TNF-α inhibited ND- and T2DM-DF migration and matrix metalloprotease expression to the same degree, although T2DM-DF expressed significantly higher levels of tissue inhibitor of metalloproteases (TIMP)-2. Finally, TNF-α significantly increased the secretion of pro-inflammatory cytokines (including CCL2, CXCL1 and SERPINE1) in ND-DF, whilst this effect in T2DM-DF was blunted, presumably due to the tendency to higher baseline pro-inflammatory cytokine expression observed in this cell type. Collectively, these data demonstrate that T2DM-DF exhibit a selective loss of responsiveness to TNF-α, particularly regarding proliferative and secretory functions. This highlights important phenotypic changes in T2DM-DF that may explain the susceptibility to chronic wounds in these patients.

Chemical Composition of a Novel Distillate from Fermented Mixture of Nine Anti-Inflammatory Herbs and Its UVB-Protective Efficacy in Mouse Dorsal Skin via Attenuating Collagen Disruption and Inflammation

Since ancient times, various herbs have been used in Asia, including Korea, China, and Japan, for wound healing and antiaging of the skin. In this study, we manufactured and chemically analyzed a novel distillate obtained from a fermented mixture of nine anti-inflammatory herbs (Angelica gigas, Lonicera japonica, Dictamnus dasycarpus Turcz., D. opposita Thunb., Ulmus davidiana var. japonica, Hordeum vulgare var. hexastichon Aschers., Xanthium strumarium L., Cnidium officinale, and Houttuynia cordata Thunb.). The fermentation of natural plants possesses beneficial effects in living systems. These activities are attributed to the chemical conversion of the parent plants to functional constituents which show more potent biological activities. In our current study, the distillate has been manufactured after fermenting the nine oriental medical plants with Lactobacillus fermentum, followed by distilling. We analyzed the chemical ingredients involved in the distillate and evaluated the effects of topical application of the distillate on ultraviolet B (UVB)-induced skin damage in Institute of Cancer Research (ICR) mice. Topical application of the distillate significantly ameliorated the macroscopic and microscopic morphology of the dorsal skin against photodamage induced by UVB radiation. Additionally, our current results showed that topical application of the distillate alleviated collagen disruption and reduced levels of proinflammatory cytokines (tumor necrosis factor alpha and interleukin 1 β expressions) in the dorsal skin against UVB radiation. Taken together, our current findings suggest that the distillate has a potential to be used as a material to develop a photoprotective adjuvant.

Spatial expression of metallothionein, matrix metalloproteinase-1 and Ki-67 in human epidermal wounds treated with zinc and determined by quantitative immunohistochemistry: A randomised double-blind trial

Reepithelialisation is fundamental to wound healing, but our current understanding largely relies on cellular and animal studies. The aim of the present randomised double-blind three-arm controlled trial was to correlate genuine epidermal wound healing with key proteins and topical zinc treatment in humans. Sixty wounds were produced using deroofed suction blisters in 30 healthy volunteers and randomised to topical zinc sulphate (n = 20), placebo (n = 20), or control (n = 20) treatment for 4 days. All wounds with perilesional skin were processed for automatic immunostaining of paraffin tissue sections with monoclonal antibodies against Ki-67, metallothionein (MT) and matrix metalloproteinase (MMP)-1. Protein expression was quantified by automated digital image analysis. Epidermal Ki-67 and MT labelling indices were increased in keratinocytes in the neoepidermis (∼1.1 mm) and at the wound edge (0.5 mm) compared to normal skin. Increased MMP-1 immunostaining was restricted to the neoepidermis. MT was robustly upregulated in the upper dermis of the wounds. Zinc treatment enhanced MMP-1 expression beneath the neoepidermis via paracrine mechanisms and MT under the neoepidermis and in the nonepithelialised wound bed via direct actions of zinc as indicated by the induction of MT2A mRNA but not MMP-1 mRNA in cultured normal human dermal fibroblasts by zinc sulphate. The present human study demonstrates that quantitative immunohistochemistry can identify proteins involved in reepithelialisation and actions of external compounds. Increased dermal MT expression may contribute to the anti-inflammatory activities of zinc and increased MMP-1 levels to promote keratinocyte migration.

Unravelling the Network of Nuclear Matrix Metalloproteinases for Targeted Drug Design

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that are responsible for the degradation of a wide range of extracellular matrix proteins, which are involved in many cellular processes to ensure the normal development of tissues and organs. Overexpression of MMPs has been observed to facilitate cellular growth, migration, and metastasis of tumor cells during cancer progression. A growing number of these proteins are being found to exist in the nuclei of both healthy and tumor cells, thus highlighting their localization as having a genuine purpose in cellular homeostasis. The mechanism underlying nuclear transport and the effects of MMP nuclear translocation have not yet been fully elucidated. To date, nuclear MMPs appear to have a unique impact on cellular apoptosis and gene regulation, which can have effects on immune response and tumor progression, and thus present themselves as potential therapeutic targets in certain types of cancer or disease. Herein, we highlight and evaluate what progress has been made in this area of research, which clearly has some value as a specific and unique way of targeting the activity of nuclear matrix metalloproteinases within various cell types.

Effect of TNFα blockade on UVB-induced inflammatory cell migration and collagen loss in mice

UVB irradiation induces pro-inflammatory cytokines including interleukin-1 (IL-1) and tumor necrosis factor-α (TNFα) in the skin. TNFα stimulates the chemotaxis of inflammatory cells to the skin. These cells secrete metalloproteinases (MMPs) and other enzymes that damage the cutaneous matrix. Therefore, blocking TNFα activity could be effective in preventing the influx of inflammatory cells and subsequent collagen degradation in the skin. In addition, TNFα downregulates procollagen mRNA, and thus blockade may be beneficial to production of type I collagen. Female C57BL/6 J mice were treated with etanercept (TNFα blocker, 4 mg/kg/day) for 4 days 1 h prior to UVB irradiation (100 mJ/cm²/day for 5 days). On the 5th day mice were sacrificed 3 h after UVB exposure. Blocking TNFα significantly inhibited UVB-induced recruitment of macrophages, mast cells, and neutrophils. UVB-irradiated mice skin contained more mature collagen compared to etanercept and UVB + etanercept-treated mice. Skin from UVB + etanercept-treated mice had more collagen fragments relative to UVB-irradiated mice. Procollagen protein was lower in UVB-irradiated and UVB + etanercept-treated mice. TNFα blockade decreased decorin and TGF-β1 in UVB-irradiated mice compared to UVB alone. MMP13 was inhibited by etanercept in UVB-irradiated mice (p < 0.01). In conclusion, blockade of TNFα significantly decreased mature collagen in UVB-irradiated mice, while increasing collagen fragmentation and decreasing procollagen.

Superficial Ulcerating Rheumatoid Necrobiosis Associated with Methotrexate Use in a Patient with Rheumatoid Arthritis

Methotrexate, a disease-modifying antirheumatic drug, is fundamental to limiting progression in several rheumatic diseases such as rheumatoid arthritis (RA). However, methotrexate is also associated with various significant adverse effects. Of note, there are several dermatologic manifestations attributed to methotrexate therapy. In particular, accelerated nodulosis and panniculitis are linked to methotrexate therapy in the current literature. The authors present the case of a 55-year-old Caucasian female with seropositive erosive RA who developed superficial ulcerating rheumatoid necrobiosis (SURN), secondary to methotrexate therapy. The patient’s treatment consisted of methotrexate discontinuation, topical clobetasol, and initiation of leflunomide as a replacement of methotrexate. Follow-up evaluation confirmed resolution of SURN over time and maintained low disease RA activity with leflunomide.Few cases describe SURN in the setting of RA and there are currently no cases published that suggest methotrexate’s possible role in SURN. Methotrexate-induced SURN is plausible in this case because of the correlation with therapy initiation and remission after therapy discontinuation. SURN has significant histological overlap with other methotrexate-induced dermatologic manifestations, allowing for a possible correlation. Most dermatological side effects of methotrexate are linked to a genetic predisposition of the HLA-DRB1 gene. Additionally, methotrexate’s mechanism of action for rheumatologic disease paradoxically stimulates adenosine-1 receptors and activates neutrophil chemotaxis and phagocytosis. Adenosine-1 receptor stimulation is hypothesised to be the source of rheumatoid-accelerated nodulosis and possibly SURN. Furthermore, the location of manifestation, genetic predisposition, and comorbid features in the patient all possibly have a role in this unique dermatological side effect.

[Suitability of biological acellular dermal matrices as a skin replacement]

INTRODUCTION

 Tissue defects are associated with loss of epidermal and dermal components of the skin. For full-thickness tissue defects, dermal equivalents are useful to enable rapid wound closure. Split-thickness skin grafts are associated with loss of tissue elasticity resulting in scar contractures that can impair joint mobility. Synthetic collagen matrices and allogeneic acellular dermal matrices (ADM) are commercially available and could serve as skin tissue replacement. The aim of this study was to investigate whether ADM of different dermal layers or bioartificial matrices can serve as cutaneous replacement. For this purpose, cellular migration, differentiation and the inflammatory reaction were studied in an established ex vivo skin organ model.

MATERIALS AND METHODS

 Human split-thickness skin grafts were transplanted onto ADM (Epiflex, DIZG, Berlin, Germany), de-epidermized dermis (DED) or an artificial collagen-elastin matrix (Matriderm, Dr. Suwelack, Billerbeck, Germany). Epithelial migration was studied using an established skin culture model at the air-liquid interface. In addition, the effect of tissue from different dermal compartments, e. g. papillar and reticular dermis, on epithelial migration was compared. Epithelial resurfacing and differentiation of matrices as well as the inflammatory reaction were studied using histological, immunohistochemical and biochemical analyses.

RESULTS AND CONCLUSION

 Significantly more epithelial outgrowth area was found on DED (2.54 mm ± 0.43 mm, mean ± SEM) compared to papillary ADM (1.32 mm ± 0.44 mm, p = 0.039), to reticular ADM (no horizontal growth, p < 0.0001) and collagen-elastin matrix (0.78 mm ± 0.11 mm, p = 0.0056) measured by fluorescence microscopy over 10 days presumably due to the presence of pro-migratory basement membrane residues on DED. Reepithelialization was significantly higher (p < 0.002) on papillary dermis compared to ADM of reticular origin. In contrast to the biological matrices, a complete horizontal penetration was found in the macroporous collagen-elastin matrix. Pro-inflammatory mediators varied depending on the human skin donor and matrix. In summary, the biochemical structure of the matrix' surface and its origin influenced the epithelial behaviour with regard to migration, differentiation and inflammatory response.

Development of a novel in vitro insulin resistance model in primary human tenocytes for diabetic tendinopathy research

Background

Type 2 diabetes mellitus (T2DM) had been reported to be associated with tendinopathy. However, the underlying mechanisms of diabetic tendinopathy still remain largely to be discovered. The purpose of this study was to develop insulin resistance (IR) model on primary human tenocytes (hTeno) culture with tumour necrosis factor-alpha (TNF-α) treatment to study tenocytes homeostasis as an implication for diabetic tendinopathy.

Methods

hTenowere isolated from human hamstring tendon. Presence of insulin receptor beta (INSR-β) on normal tendon tissues and the hTeno monolayer culture were analyzed by immunofluorescence staining. The presence of Glucose Transporter Type 1 (GLUT1) and Glucose Transporter Type 4 (GLUT4) on the hTeno monolayer culture were also analyzed by immunofluorescence staining. Primary hTeno were treated with 0.008, 0.08, 0.8 and 8.0 µM of TNF-α, with and without insulin supplement. Outcome measures include 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) assay to determine the glucose uptake activity; colourimetric total collagen assay to quantify the total collagen expression levels; COL-I ELISA assay to measure the COL-I expression levels and real-time qPCR to analyze the mRNA gene expressions levels of Scleraxis (SCX), Mohawk (MKX), type I collagen (COL1A1), type III collagen (COL3A1), matrix metalloproteinases (MMP)-9 and MMP-13 in hTeno when treated with TNF-α. Apoptosis assay for hTeno induced with TNF-α was conducted using Annexin-V FITC flow cytometry analysis.

Results

Immunofluorescence imaging showed the presence of INSR-β on the hTeno in the human Achilles tendon tissues and in the hTeno in monolayer culture. GLUT1 and GLUT4 were both positively expressed in the hTeno. TNF-α significantly reduced the insulin-mediated 2-NBDG uptake in all the tested concentrations, especially at 0.008 µM. Total collagen expression levels and COL-I expression levels in hTeno were also significantly reduced in hTeno treated with 0.008 µM of TNF-α. The SCX, MKX and COL1A1 mRNA expression levels were significantly downregulated in all TNF-α treated hTeno, whereas the COL3A1, MMP-9 and MMP-13 were significantly upregulated in the TNF–α treated cells. TNF-α progressively increased the apoptotic cells at 48 and 72 h.

Conclusion

At 0.008 µM of TNF-α, an IR condition was induced in hTeno, supported with the significant reduction in glucose uptake, as well as significantly reduced total collagen, specifically COL-I expression levels, downregulation of candidate tenogenic markers genes (SCX and MKX), and upregulation of ECM catabolic genes (MMP-9 and MMP-13). Development of novel IR model in hTeno provides an insight on how tendon homeostasis could be affected and can be used as a tool for further discovering the effects on downstream molecular pathways, as the implication for diabetic tendinopathy.

The Combination of Sulforaphane and Fernblock® XP Improves Individual Beneficial Effects in Normal and Neoplastic Human Skin Cell Lines

Plenty of evidence supports the health effects exerted by dietary supplements containing phytochemicals, but the actual efficacy and safety of their combinations have been seldom experimentally evaluated. On this basis, we investigated in vitro the antioxidant/antineoplastic efficacy and anti-aging activity of a dietary supplement containing sulforaphane (SFN), a sulfur-isothiocyanate present in broccoli, combined with the patented extract Fernblock^® XP (FB), obtained from the tropical fern Polypodium leucotomos. We evaluated the effect of SFN and FB, alone or in combination, on migration ability, matrix metalloproteinases (MMP) production, neoangiogenic potential and inflammasome activation in human WM115 and WM266-4 melanoma cells. Moreover, the effects on MMPs and reactive oxygen species production, and IL-1β secretion were studied in human normal keratinocytes. The SFN/FB combination inhibited melanoma cell migration in vitro, MMP-1, -2, -3, and -9 production, inflammasome activation and IL-1β secretion more efficiently than each individual compound did. In normal keratinocytes, SFN/FB was more efficient than SFN or FB alone in inhibiting MMP-1 and -3 production and IL-1β secretion in the presence of a pro-inflammatory stimulus such as TNF-α. The potential use of SFN/FB based supplements for the prevention of skin aging and as adjuvants in the treatment of advanced melanoma is suggested.

Metalloproteinases and Their Inhibitors: Potential for the Development of New Therapeutics

The metalloproteinase (MP) family of zinc-dependent proteases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteases (ADAMs), and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) plays a crucial role in the extracellular matrix (ECM) remodeling and degradation activities. A wide range of substrates of the MP family includes ECM components, chemokines, cell receptors, and growth factors. Metalloproteinases activities are tightly regulated by proteolytic activation and inhibition via their natural inhibitors, tissue inhibitors of metalloproteinases (TIMPs), and the imbalance of the activation and inhibition is responsible in progression or inhibition of several diseases, e.g., cancer, neurological disorders, and cardiovascular diseases. We provide an overview of the structure, function, and the multifaceted role of MMPs, ADAMs, and TIMPs in several diseases via their cellular functions such as proteolysis of other cell signaling factors, degradation and remodeling of the ECM, and other essential protease-independent interactions in the ECM. The significance of MP inhibitors targeting specific MMP or ADAMs with high selectivity is also discussed. Recent advances and techniques used in developing novel MP inhibitors and MP responsive drug delivery tools are also reviewed.

Matrix Metalloproteinases: How Much Can They Do?

Zinc-dependent matrix metalloproteinases (MMPs) belong to metzincins that comprise not only 23 human MMPs but also other metalloproteinases, such as 21 human ADAMs (a disintegrin and metalloproteinase domain) and 19 secreted ADAMTSs (a disintegrin and metalloproteinase thrombospondin domain). The many setbacks from the clinical trials of broad-spectrum MMP inhibitors for cancer indications in the late 1990s emphasized the extreme complexity of the participation of these proteolytic enzymes in biology. This editorial mini-review summarizes the Special Issue, which includes four review articles and 10 original articles that highlight the versatile roles of MMPs, ADAMs, and ADAMTSs, in normal physiology as well as in neoplastic and destructive processes in tissue. In addition, we briefly discuss the unambiguous involvement of MMPs in wound healing.

Matrix Metalloproteinase-3 is Key Effector of TNF-α-Induced Collagen Degradation in Skin

Inflammatory processes in the skin augment collagen degradation due to the up-regulation of matrix metalloproteinases (MMPs). The aim of the present project was to study the specific impact of MMP-3 on collagen loss in skin and its interplay with the collagenase MMP-13 under inflammatory conditions mimicked by the addition of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Skin explants from MMP-3 knock-out (KO) mice or from transgenic (TG) mice overexpressing MMP-3 in the skin and their respective wild-type counterparts (WT and WTT) were incubated ex vivo for eight days. The rate of collagen degradation, measured by released hydroxyproline, was reduced (p < 0.001) in KO skin explants compared to WT control skin but did not differ (p = 0.47) between TG and WTT skin. Treatment with the MMP inhibitor GM6001 reduced hydroxyproline media levels from WT, WTT and TG but not from KO skin explants. TNF-α increased collagen degradation in the WT group (p = 0.0001) only. More of the active form of MMP-13 was observed in the three MMP-3 expressing groups (co-incubation with receptor-associated protein stabilized MMP-13 subforms and enhanced detection in the media). In summary, the innate level of MMP-3 seems responsible for the accelerated loss of cutaneous collagen under inflammatory conditions, possibly via MMP-13 in mice.

Uncontrolled gelatin degradation in non-healing chronic wounds

OBJECTIVE

To compare matrix metalloproteinase (MMP)-9 and the antiproteinase tissue inhibitor of metalloproteinases (TIMP)-1 in wound fluids and sera from patients with chronic non-healing or acute healing wounds. In addition, the functional consequences on MMP-9 activity and general gelatinase activity were assessed.

METHOD

In this observational study, samples were collected from patients with venous leg ulcers (VLUs), patients with type 2 diabetes with neuropathic foot ulcers (DFUs), and from another cohort of VLU patients with sterile split-thickness skin graft donor sites after autologous skin grafting, serving as healing control wounds. MMP-9 and TIMP-1 concentrations were determined by enzyme-linked immunosorbent assays. MMP-9 and gelatinase activities were determined in wound fluids in subsets of the patients.

RESULTS

A total of 24 patients took part in the study. No significant differences in MMP-9 wound fluid levels were found among the three groups. TIMP-1 levels were markedly and significantly lower in the two chronic wound groups resulting in a severely unbalanced MMP-9/TIMP-1 ratio, especially notable in the VLU group and possibly in the elevated endogenous MMP-9 activity (p<0.01) compared with the acute wound fluids. At least 20% of the chronic wound fluids displayed atypical patterns on gelatin zymography and showed high general gelatinase activity that was not inhibited by either TIMP-1 or by a gelatinase inhibitor (AG3340). MMP-9 levels were higher in the sera of the patients with type 2 diabetes.

CONCLUSION

We hypothesise that non-MMP proteinases contribute to matrix destruction in a significant number of chronic wounds. Blocking the excessive MMP-9 activity may be insufficient to normalise wound healing. The reasons and effects of the very low TIMP-1 levels in chronic wounds need further clarification.

ERK1/ATF-2 signaling axis contributes to interleukin-1β-induced MMP-3 expression in dermal fibroblasts

Matrix metalloproteinases (MMPs) play a pivotal role in tissue remodeling by degrading the extracellular matrix (ECM) components. This mechanism is implicated in a variety of physiological and pathological cellular processes including wound healing. One of the key proteins involved in this process is the proinflammatory cytokine interleukin-1β (IL-1β, which induces the expression of MMP-3 mRNA and the secretion of MMP-3 protein by dermal fibroblasts. In this study, we first investigated the contribution of activating transcription factor 2 (ATF-2) to IL-1β-induced MMP-3 expression in dermal fibroblasts. Our results showed that in cells transfected with ATF-2 siRNA or treated with the ATF-2 inhibitor SBI-0087702, IL-1β-induced MMP-3 mRNA expression was reduced. We also demonstrated that IL-1β stimulates the phosphorylation of ATF-2. These observations suggest that ATF-2 plays an important role in IL-1β-induced MMP-3 expression. Next, we investigated the role of MAPK signaling in ATF-2 activation. In cells treated with the extracellular signal-regulated kinase (ERK) inhibitor FR180240, as well as in cells transfected with ERK1 and ERK2 siRNAs, IL-1β-induced MMP-3 mRNA expression was reduced. In addition, we showed that IL-1β induced the phosphorylation of ERK1/2. These observations suggest that ERK1 and ERK2 are involved in IL-1β-induced MMP-3 expression. However, ERK1 and ERK2 do seem to play different roles. While the ERK inhibitor FR180204 inhibited IL-1β-induced ATF-2 phosphorylation, only in cells transfected with ERK1 siRNA, but not ERK2 siRNA, IL-1β-induced ATF-2 phosphorylation was reduced. These findings suggest that the ERK1/ATF-2 signaling axis contributes to IL-1β-induced MMP-3 expression in dermal fibroblasts.

Scarless wound healing: From development to senescence

An essential element of tissue homeostasis is the response to injuries, cutaneous wound healing being the most studied example. In the adults, wound healing aims at quickly restoring the barrier function of the skin, leading however to scar, a dysfunctional fibrotic tissue. On the other hand, in fetuses a scarless tissue regeneration takes place. During ageing, the wound healing capacity declines; however, in the absence of comorbidities a higher quality in tissue repair is observed. Senescent cells have been found to accumulate in chronic unhealed wounds, but more recent reports indicate that their transient presence may be beneficial for tissue repair. In this review data on skin wound healing and scarring are presented, covering the whole spectrum from early embryonic development to adulthood, and furthermore until ageing of the organism.

Novel specific human and mouse stromelysin-1 (MMP-3) and stromelysin-2 (MMP-10) antibodies for biochemical and immunohistochemical analyses

Matrix metalloproteinases (MMP) are a family of more than 25 zinc-dependent enzymes that are centrally involved in cellular migration, tissue remodeling, cancer invasion and metastasis. Besides degrading extracellular matrix proteins, MMPs are crucial for growth factor and cytokine release and activation. At the same time, they can inactivate inflammatory mediators and enzymes themselves through protein degradation. Subclasses of MMPs include collagenases, gelatinases, stromelysins, membrane-bound MMPs, and others. With regard to the stromelysin subfamily, three members exist, e.g., stromelysin-1 (MMP-3), stromelysin-2 (MMP-10), and stromelysin-3 (MMP-11). MMP-3, and MMP-10 share extensive similarities at the amino acid level that made it difficult to develop specific antibodies distinguishing between MMP-3 and MMP-10. Scrutinizing published data on and performing different analyses with detection of both stromelysins with commercially available or lab-made antibodies showed ambiguous results with regard to specificity of antibodies used to date. We developed new specific antibodies against the most divergent parts of the active forms of both proteins. We assessed the specificity of our novel specific anti-human and anti-mouse MMP-3 and MMP-10 antibodies in cell lysates and different human and murine skin tissues. Tests analyzing specificity of the novel antibodies included Western immunoblotting, immunofluorescence, and immunohistochemistry on paraffin sections. Analyses demonstrated specific detection of respective protein for human or mouse samples except for the anti-human MMP-3 antibody. The aim of this summary was to call attention the MMP research community to distinguish clearly between both enzymes. Our new specific anti-mouse MMP-3 and both MMP-10 antibodies allow us to address this detection problem and to enable comparative studies between both stromelysins with regard to their respective location and function in the tissue.

Oxidative stress induced by self-adhesive resin cements affects gene expression, cellular proliferation and mineralization potential of the MDPC-23 odontoblast-like cells

OBJECTIVE

Clinical issues have been raised about problems related to cytotoxic effects caused when applying self-adhesive cement. It was hypothesized that byproducts eluted from self-adhesive cements modulate oxidative stress response, the gene expression of signaling pathways of inflammatory process/transcriptional activators, and the expression and activity of interstitial collagenases, and modify the phenotypic characteristics of cellular proliferation and mineral deposition in odontoblastic-like cells.

METHODS

Cements (MaxCem Elite [MAX] and RelyX U200 [U200)]) were mixed, dispensed into moulds, and photoactivated according to the manufacturers' instructions. Immortalized rat odontoblast-like cells (MDPC-23) were cultured and exposed to polymerized specimens of cements for 4 h. Reactive oxidative specimen production and quantification of gene expression were evaluated. Cell proliferation assay and alizarin red staining were also performed to evaluate the disturbance induced by the cements on cellular proliferation and mineralization.

RESULTS

Despite their cytotoxic effects, both self-adhesive cements influenced the metabolism in the odontoblast cells on different scales. MAX induced significantly higher oxidative stress in odontoblast cells than U200. Gene expression varied as a function of exposure to self-adhesive cements; MAX induced the expression of pro-inflammatory cytokines such as TNF-α, whereas U200 downregulated, virtually depleted TNF-α expression, also inducing overexpression of the transcriptional factor Runx2. Overexpression of heme oxygenase-1 (HO-1) and thioredoxin reductase 1 (TRXR1) occurred after exposure to both cements, antioxidant genes that are downstream of Keap1-Nrf2-ARE system. MAX significantly induced the overexpression of collagenase MMP-1, and U200 induced the expression of gelatinase MMP-2. MAX significantly inhibited cell proliferation whereas U200 significantly activated cell proliferation. Alizarin red staining revealed significantly decreased mineral deposition especially when exposed to MAX.

SIGNIFICANCE

These results support the hypothesis that byproducts of different self-adhesive cements play important roles in the highly orchestrated process which ultimately affect the cellular proliferation and the mineral deposition in odontoblastic-like cells, possibly delaying the reparative dentin formation after cementation of indirect restorations, especially on recently exposed dentin preparations.

Subendothelial matrix components influence endothelial cell apoptosis in vitro

The programmed form of cell death (apoptosis) is essential for normal development of multicellular organisms. Dysregulation of apoptosis has been linked with embryonal death and is involved in the pathophysiology of various diseases. Specifically, endothelial apoptosis plays pivotal roles in atherosclerosis whereas prevention of endothelial apoptosis is a prerequisite for neovascularization in tumors and metastasis. Endothelial biology is intertwined with the composition of subendothelial basement membrane proteins. Apoptosis was induced by addition of tumor necrosis factor-α to cycloheximide-sensitized endothelial cells. Cells were either grown on polystyrene culture plates or on plates precoated with healthy basement membrane proteins (collagen IV, fibronectin, or laminin) or collagen I. Our results reveal that proteins of healthy basement membrane alleviate cytokine-induced apoptosis whereas precoating with collagen type I had no significant effect on apoptosis by addition of tumor necrosis factor-α to cycloheximide-sensitized endothelial cells compared with cells cultured on uncoated plates. Yet, treatment with transforming growth factor-β1 significantly reduced the rate of apoptosis endothelial cells grown on collagen I. Detailed analysis reveals differences in intracellular signaling pathways for each of the basement membrane proteins studied. We provide additional insights into the importance of basement membrane proteins and the respective cytokine milieu on endothelial biology. Exploring outside-in signaling by basement membrane proteins may constitute an interesting target to restore vascular function and prevent complications in the atherosclerotic cascade.

Protective effect of pre- and post-vitamin C treatments on UVB-irradiation-induced skin damage

Several studies have reported the effects of vitamin C (L-ascorbic acid, AA) on ultraviolet B (UVB)-induced cell damage using cultured keratinocytes. However, the epidermis consists of multiple cell layers, and the effect of AA on UVB-induced damage to the human epidermis remains unclear. Therefore, we investigated the effect of AA on UVB-induced skin damage using reconstituted human epidermis. The reconstituted human epidermal surface was treated with 100 and 500 mM AA and cultured for 3 h before (pre-AA treatment) or after (post-AA treatment) 120 mJ/cm² UVB irradiation. Pre- and post-AA treatments of the epidermal surface suppressed UVB-induced cell death, apoptosis, DNA damage, reactive oxygen species (ROS) production, and the inflammatory response by downregulating tumour necrosis factor-α (TNF-α) expression and release. Moreover, the pre-AA treatment was more effective at preventing UVB-induced skin damage than the post-AA treatment. In summary, pre- and post-AA treatments of the epidermis prevent UVB-induced damage.

The Impact of Human Papilloma Viruses, Matrix Metallo-Proteinases and HIV Protease Inhibitors on the Onset and Progression of Uterine Cervix Epithelial Tumors: A Review of Preclinical and Clinical Studies

Infection of uterine cervix epithelial cells by the Human Papilloma Viruses (HPV) is associated with the development of dysplastic/hyperplastic lesions, termed cervical intraepithelial neoplasia (CIN). CIN lesions may regress, persist or progress to invasive cervical carcinoma (CC), a leading cause of death worldwide. CIN is particularly frequent and aggressive in women infected by both HPV and the Human Immunodeficiency Virus (HIV), as compared to the general female population. In these individuals, however, therapeutic regimens employing HIV protease inhibitors (HIV-PI) have reduced CIN incidence and/or clinical progression, shedding light on the mechanism(s) of its development. This article reviews published work concerning: (i) the role of HPV proteins (including HPV-E5, E6 and E7) and of matrix-metalloproteinases (MMPs) in CIN evolution into invasive CC; and (ii) the effect of HIV-PI on events leading to CIN progression such as basement membrane and extracellular matrix invasion by HPV-positive CIN cells and the formation of new blood vessels. Results from the reviewed literature indicate that CIN clinical progression can be monitored by evaluating the expression of MMPs and HPV proteins and they suggest the use of HIV-PI or their derivatives for the block of CIN evolution into CC in both HIV-infected and uninfected women.

Serum levels of matrix metalloproteinase-3 and autoantibodies related to rheumatoid arthritis in the general Japanese population and their association with osteoporosis and osteoarthritis: the ROAD study

To purpose of this study was to reveal the mean levels and positive proportion of serological markers related to rheumatoid arthritis, and clarify their relationship with osteoporosis and hand osteoarthritis (OA). A total of 1546 participants from the third survey of the research on osteoarthritis/osteoporosis against disability study were enrolled in the current study. Using participant blood samples, the levels of anti-cyclic citrullinated protein (CCP) antibody, rheumatoid factor (RF), matrix metalloproteinase-3 (MMP-3), C-reactive protein (CRP), and high-sensitivity CRP (hsCRP) were measured. Subjects with higher than normal levels were defined as being positive. Osteoporosis was defined according to the recommendations set by World Health Organization criteria in 1994. Radiographic hand OA was evaluated using the modified Kellgren-Lawrence (KL) scale. The positive proportion of anti-CCP antibody, RF, MMP-3, CRP, and hsCRP was 1.8, 7.1, 15.0, 6.7, and 6.4%, respectively. MMP-3 was associated with age, and was significantly higher in men than in women. Positive MMP-3 was not significantly related to osteoporosis or severe hand OA (KL grade ≥3) after adjustment for other factors including age, sex, and body mass index. The results from this study clarified the values and positive proportion of RA-related markers and revealed their relationship with osteoporosis and hand OA.

Influence of MMP inhibitor GM6001 loading of fibre coated polypropylene meshes on wound healing: Implications for hernia repair

Polypropylene meshes are standard for hernia repair. Matrix metalloproteinases play a central role in inflammation. To reduce the inflammatory response and improve remodelling with an associated reduction of hernia recurrence, we modified polypropylene meshes by nanofibre coating and saturation with the broad-spectrum matrix metalloproteinase inhibitor GM6001. The aim was to modulate the inflammatory reaction, increase collagen deposition and improve mesh biointegration. Polypropylene meshes were surface-modified with star-configured NCO-sP(EO -stat-PO) and covered with electrospun nanofibres (polypropylene-nano) and GM6001 (polypropylene-nano-GM). In a hernia model, defects were reconstructed with one of the meshes. Inflammation, neovascularization, bio-integration, proliferation and apoptosis were assessed histologically, collagen content and gelatinases biochemically. Mesh surface modification resulted in higher inflammatory response compared to polypropylene. Pro-inflammatory matrix metalloproteinase-9 paralleled findings while GM6001 reduced matrix metalloproteinase-9 significantly. Significantly increased matrix metalloproteinase-2 beneficial for remodelling was noted with polypropylene-nano-meshes. Increased vascular endothelial growth factor, neo-vascularization and collagen content were measured in polypropylene-nano-meshes compared to polypropylene. GM6001 significantly reduced myofibroblasts. This effect ended after d14 due to engineering limitations with release of maximal GM6001 loading. Nanofibre-coating of polypropylene-meshes confers better tissue vascularization to the cost of increased inflammation. This phenomenon can be only partially compensated by GM6001. Future research will enable higher GM6001 uptake in nano-coated meshes and may alter mesh biointegration in a more pronounced way.

Extracellular matrix regulation of fibroblast function: redefining our perspective on skin aging

The dermal extracellular matrix (ECM) comprises the bulk of skin and confers strength and resiliency. In young skin, fibroblasts produce and adhere to the dermal ECM, which is composed primarily of type I collagen fibrils. Adherence allows fibroblasts to spread and exert mechanical force on the surrounding ECM. In this state, fibroblasts display a "youthful" phenotype characterized by maintenance of the composition and structural organization of the dermal ECM. During aging, fibroblast-ECM interactions become disrupted due to fragmentation of collagen fibrils. This disruption causes loss of fibroblast spreading and mechanical force, which inextricably lead to an "aged" phenotype; fibroblasts synthesize less ECM proteins and more matrix-degrading metalloproteinases. This imbalance of ECM homeostasis further drives collagen fibril fragmentation in a self-perpetuating cycle. This article summarizes age-related changes in the dermal ECM and the mechanisms by which these changes alter the interplay between fibroblasts and their extracellular matrix microenvironment that drive the aging process in human skin.