Differential regulation of galectin expression/reactivity during wound healing in porcine skin and in cultures of epidermal cells with functional impact on migration

Prevalence, Risk Factors, Pathophysiology, Potential Biomarkers and Management of Feline Idiopathic Cystitis: An Update Review

Feline idiopathic cystitis is a widespread disease in small animal clinics, which mainly presents with urinary signs like dysuria, stranguria, hematuria, pollakiuria, and periuria. The etiopathogenesis of the disease may involve interactions between the environmental stressors, neuroendocrine system and bladder of affected cats. Diagnostic biomarkers have not been tested in clinical studies though they are theoretically feasible, and since the clinical signs of the disease assemble those of other feline lower urinary diseases, its diagnosis is a procedure of exclusion. The primary treatment of the disease is long-term multimodal environmental modification (or enrichment) while anti-anxiety drugs and nutritional supplements are recommended for chronic recurrent cases. Still, many medicines need to be evaluated for their efficacy and safety. This review aims to provide readers with a comprehensive understanding of feline idiopathic cystitis by summarizing and updating studies concerning the prevalence, risk factors, etiological hypotheses, diagnostic procedures, possible treatments, and prognosis of the disease.

Expression Pattern and Immunoregulatory Roles of Galectin-1 and Galectin-3 in Atopic Dermatitis and Psoriasis

The pathogenesis of atopic dermatitis (AD) and psoriasis (Ps) overlaps, particularly the activation of the immune response and tissue damage. Here, we evaluated galectin (Gal)-1 and Gal-3 levels, which are beta-galactoside-binding proteins with immunomodulatory functions and examined their effects on human keratinocytes stimulated with either interleukin (IL)-4 or IL-17A. Skin biopsies from AD, Ps, and control patients were evaluated using histological and immunohistochemical analyses. Six studies containing publicly available transcriptome data were individually analyzed using the GEO2R tool to detect Gal-1 and Gal-3 mRNA levels. In vitro, IL-4- or IL-17A-stimulated keratinocytes were treated with or without Gal-1 or Gal-3 to evaluate cytokine release and migration. Our findings showed different patterns of expression for Gal-1 and Gal-3 in AD and Ps skins. Densitometric analysis in skin samples showed a marked increase in the protein Gal-1 levels in Ps epidermis and in both AD and Ps dermis compared to controls. Protein and mRNA Gal-3 levels were downregulated in AD and Ps lesional skin compared with the control samples. In vitro, both galectins addition abrogated the release of IL-8 and RANTES in IL-17-stimulated keratinocytes after 24 h, whereas IL-6 release was downregulated by Gal-3 and Gal-1 in IL-4- and IL-17-stimulated cells, respectively. Administration of both galectins also increased the rate of keratinocyte migration under IL-4 or IL-17 stimulation conditions compared with untreated cells. Altogether, the immunoregulatory and migration effects of Gal-1 and Gal-3 on keratinocytes under inflammatory microenvironment make them interesting targets for future therapies in cutaneous diseases.

Carboxylated-xyloglucan and peptide amphiphile co-assembly in wound healing

Hydrogel wound dressings can play critical roles in wound healing protecting the wound from trauma or contamination and providing an ideal environment to support the growth of endogenous cells and promote wound closure. This work presents a self-assembling hydrogel dressing that can assist the wound repair process mimicking the hierarchical structure of skin extracellular matrix. To this aim, the co-assembly behaviour of a carboxylated variant of xyloglucan (CXG) with a peptide amphiphile (PA-H3) has been investigated to generate hierarchical constructs with tuneable molecular composition, structure, and properties. Transmission electron microscopy and circular dichroism at a low concentration shows that CXG and PA-H3 co-assemble into nanofibres by hydrophobic and electrostatic interactions and further aggregate into nanofibre bundles and networks. At a higher concentration, CXG and PA-H3 yield hydrogels that have been characterized for their morphology by scanning electron microscopy and for the mechanical properties by small-amplitude oscillatory shear rheological measurements and compression tests at different CXG/PA-H3 ratios. A preliminary biological evaluation has been carried out both in vitro with HaCat cells and in vivo in a mouse model.

Interaction of galectin-7 with HMGCS1 in vitro may facilitate cholesterol deposition in cultured keratinocytes

Three-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase 1 (HMGCS1) was identified to interact with Gal-7, a pro-apoptotic β-galactoside binding protein, by yeast two-hybrid system. Their interaction was confirmed by in vitro β-galactosidase, BIA core and immunoprecipitation assays. Distinct interactive site of HMGCS1was found to reside at Phe-26. The expression of HMGCS1 in cultured keratinocytes was up-regulated by exogenous Gal-7 and down-regulated in Gal-7 siRNA transfected cells. HMGCS1-overexpressing cells were found to induce Gal-7 expression, which suggests that Gal-7 and HMGCS1 expressions are both stimulated by a positive feedback regulation. The amount of cholesterol, a final biosynthetic product of HMGCS1-involved pathway, was increased in Gal-7 treated cells, and was significantly reduced in Gal-7 siRNA transfected cells. The increase of cholesterol level in Gal-7 treated cells was inhibited by wild type HMGCS1 peptide but not by Phe-26 mutated peptide, suggesting that the interaction of Gal-7/HMGCS1 is related to cellular cholesterol level. Foam cells in granulomatous tissues of the specimens from normolipemic cutaneous xanthoma showed positive reactions with the antibodies for Gal-7 and HMGCS1 as well as lipid markers. These results are likely to indicate that Gal-7 induction in epidermal keratinocytes causes both apoptotic cell death and HMGCS1-mediated cholesterol accumulation which will be phagocytized by macrophages. This mechanism may explain the pathogenesis of normolipemic cutaneous xanthoma.

Human galectin‑3: Molecular switch of gene expression in dermal fibroblasts in vitro and of skin collagen organization in open wounds and tensile strength in incisions in vivo

Understanding the molecular and cellular processes in skin wound healing can pave the way for devising innovative concepts by turning the identified natural effectors into therapeutic tools. Based on the concept of broad-scale engagement of members of the family of galactoside-binding lectins (galectins) in pathophysiological processes, such as cancer or tissue repair/regeneration, the present study investigated the potential of galectins-1 (Gal-1) and −3 (Gal-3) in wound healing. Human dermal fibroblasts, which are key cells involved in skin wound healing, responded to galectin exposure (Gal-1 at 300 or Gal-3 at 600 ng/ml) with selective changes in gene expression among a panel of 84 wound-healing-related genes, as well as remodeling of the extracellular matrix. In the case of Gal-3, positive expression of Ki67 and cell number increased when using a decellularized matrix produced by Gal-3-treated fibroblasts as substrate for culture of interfollicular keratinocytes. In vivo wounds were topically treated with 20 μg/ml Gal-1 or −3, and collagen score was found to be elevated in excisional wound repair in rats treated with Gal-3. The tensile strength measured in incisions was significantly increased from 79.5±17.5 g/mm² in controls to 103.1±21.4 g/mm² after 21 days of healing. These data warrant further testing mixtures of galectins and other types of compounds, for example a combination of galectins and TGF-β1.

A Skin Rejection Grading System for Vascularized Composite Allotransplantation in a Preclinical Large Animal Model

BACKGROUND

The Banff Criteria have been accepted as a system for grading histological rejection in graft skin in human vascularized composite allotransplantation (VCA). Preclinical swine hindlimb transplantation models have an important role in translational studies in VCA. However, unified grading criteria for rejection in swine skin have not yet been established.

METHODS

Two hundred fourteen swine skin biopsy specimens were reviewed, including 88 native skin biopsies and 126 specimens from the skin component of heterotopic swine hindlimb transplants. Thorough review was performed in a blinded fashion by an expert veterinary pathologist with attention paid to the applicability of the Banff criteria as well as specific histologic characteristics and trends. Clinical and histopathologic rejection scores were then directly compared.

RESULTS

Two hundred fourteen specimens reviewed showed significant similarities between swine and human skin, as previously published. Notable swine-specific characteristics, including paucicellular infiltration with rare epidermal cell infiltration or necrosis, were accounted for in a proposed grading system that parallels the Banff Criteria.

CONCLUSIONS

This comprehensive grading system, based on the Banff Classification for skin rejection in VCA, provides a standardized system for more accurate comparison of rejection in preclinical swine VCA models.

The expression and function of galectins in skin physiology and pathology

The galectin family comprises β-galactoside-binding proteins widely expressed in many organisms. There are at least 16 family members, which can be classified into three groups based on their carbohydrate-recognition domains. Pleiotropic functions of different galectins in physiological and pathological processes through extracellular or intracellular actions have been revealed. In the skin, galectins are expressed in a variety of cells, including keratinocytes, melanocytes, fibroblasts, dendritic cells, lymphocytes, macrophages and endothelial cells. Expression of specific galectins is reported to affect cell status, such as activation or death, and regulate the interaction between different cell types or between cells and the extracellular matrix. In vitro cellular studies, in vivo animal studies and studies of human clinical material have revealed the pathophysiologic roles of galectins in the skin. The pathogenesis of diverse non-malignant skin disorders, such as atopic dermatitis, psoriasis, contact dermatitis and wound healing, as well as skin cancers, such as melanoma, squamous cell carcinoma, basal cell carcinoma and cutaneous haematologic malignancy can be regulated by different galectins. Revelation of biological roles of galectins in skin may pave the way to future development of galectin-based therapeutic strategies for skin diseases.

Comparative characterization of two galectins excreted-secreted from intestine-dwelling parasitic versus free-living females of the soil-transmitted nematode Strongyloides

Helminths are complex pathogens that ensure their long-term survival by influencing the immune responses of their host. Excretory/secretory products (ESP) can exert immunoregulatory effects which foster parasite survival. Galectins represent a widespread group of β-galactoside-binding proteins which are involved in a multitude of biological processes operative in parasite-host interaction. We had earlier identified seven galectins in Strongyloides ratti, four of them detected in the ESP of distinct developmental stages of the parasite. In the present report, we focused on the characterization of two of them, Sr-galectin-1 (Sr-Gal-1) and Sr-galectin-3 (Sr-Gal-3). While Sr-Gal-3 expression was strongest in parasitic females, Sr-Gal-1 was predominantly expressed in free-living females. Both proteins were cloned and recombinantly expressed in an E. coli expression system. Their glycan-binding activity was verified by haemagglutination and glycan array analysis. Furthermore, primary immunological activities of the Sr-galectins were initially investigated by the application of an in vitro mucosal 3D-culture model, comprising of mucosa-associated epithelial and dendritic cells. The Sr-galectins stimulated preferentially the release of the type 2 cytokines thymic stromal lymphopoietin and IL-22, a first indication for immunoregulatory activity. In addition, the Sr-galectins dose-dependently fostered cell migration. Our results confirm the importance of these carbohydrate-binding proteins in host-parasite-interaction by indicating possible interaction with the host mucosa-associated cells.

Galectin-7 in Epithelial Homeostasis and Carcinomas

Galectins are small unglycosylated soluble lectins distributed both inside and outside the cells. They share a conserved domain for the recognition of carbohydrates (CRD). Although galectins have a common affinity for β-galatosides, they exhibit different binding preferences for complex glycans. First described twenty years ago, galectin-7 is a prototypic galectin, with a single CRD, able to form divalent homodimers. This lectin, which is mainly expressed in stratified epithelia, has been described in epithelial tissues as being involved in apoptotic responses, in proliferation and differentiation but also in cell adhesion and migration. Most members of the galectins family have been associated with cancer biology. One of the main functions of galectins in cancer is their immunomodulating potential and anti-angiogenic activity. Indeed, galectin-1 and -3, are already targeted in clinical trials. Another relevant function of galectins in tumour progression is their ability to regulate cell migration and cell adhesion. Among these galectins, galectin-7 is abnormally expressed in various cancers, most prominently in carcinomas, and is involved in cancer progression and metastasis but its precise functions in tumour biology remain poorly understood. In this issue, we will focus on the physiological functions of galectin-7 in epithelia and present the alterations of galectin-7 expression in carcinomas with the aim to describe its possible functions in tumour progression.

How Signaling Molecules Regulate Tumor Microenvironment: Parallels to Wound Repair

It is now suggested that the inhibition of biological programs that are associated with the tumor microenvironment may be critical to the diagnostics, prevention and treatment of cancer. On the other hand, a suitable wound microenvironment would accelerate tissue repair and prevent extensive scar formation. In the present review paper, we define key signaling molecules (growth factors, cytokines, chemokines, and galectins) involved in the formation of the tumor microenvironment that decrease overall survival and increase drug resistance in cancer suffering patients. Additional attention will also be given to show whether targeted modulation of these regulators promote tissue regeneration and wound management. Whole-genome transcriptome profiling, in vitro and animal experiments revealed that interleukin 6, interleukin 8, chemokine (C-X-C motif) ligand 1, galectin-1, and selected proteins of the extracellular matrix (e.g., fibronectin) do have similar regulation during wound healing and tumor growth. Published data demonstrate remarkable similarities between the tumor and wound microenvironments. Therefore, tailor made manipulation of cancer stroma can have important therapeutic consequences. Moreover, better understanding of cancer cell-stroma interaction can help to improve wound healing by supporting granulation tissue formation and process of reepithelization of extensive and chronic wounds as well as prevention of hypertrophic scars and formation of keloids.

Anti-inflammatory effect of galectin-1 in a murine model of atopic dermatitis

Atopic dermatitis (AD) is caused by both dysregulated immune responses and an impaired skin barrier. Although beta-galactoside-binding protein galectin-1 (Gal-1) has immunomodulatory effects in several inflammatory disorders, therapeutic strategies based on its anti-inflammatory properties have not been explored in AD. Thus, we evaluate pharmacological treatment with Gal-1 in the progression of an ovalbumin (OVA)-induced AD-like skin lesions. The skin of OVA-immunized male BALB/c mice was challenged with drops containing OVA on days 11, 14-18 and 21-24. Additionally, in the last week, a subset of animals was treated intraperitoneally with recombinant Gal-1 (rGal-1) or dexamethasone (Dex). Treatment with rGal-1 decreased the clinical signs of dermatitis in BALB/c mice and diminished local eotaxin and IFN-γ levels. The treatment also suppressed the infiltration of eosinophils and mast cells, which was verified by reduced expression of mouse mast cell protease 6 (mMCP6) and eosinophil peroxidase (EPX). These localized effects are associated with extracellular signal-regulated kinase (ERK) activation and downregulation of endogenous Gal-1. The inhibition of disease progression induced by rGal-1 was also correlated with reduced plasma IL-17 levels. Our results demonstrate that rGal-1 is an effective treatment for allergic skin inflammation in AD and may impact the development of novel strategies for skin inflammatory diseases.

KEY MESSAGES

Pharmacological treatment with rGal-1 reduces clinical signs of atopic dermatitis. Systemic treatment with rGal-1 inhibits eosinophil and mast cell influx in the skin of AD animals. rGal-1 reduced local eotaxin levels and systemic IL-17 levels. The inhibition of disease progression induced by rGal-1 was correlated with upregulation of phosphorylated ERK.

Galectin expression in healing wounded skin treated with low-temperature plasma: Comparison with treatment by electronical coagulation

Low-temperature plasma is useful for the care of wounded skin. It accelerates wound healing. However, the mechanism of this effect has not been fully elucidated yet. Galectin-1 is reported to accelerate wound healing via the Smad signaling pathway. In the present study to clarify whether or not galectins were expressed during the process of wound healing in the plasma-treated skin, we examined the effect of low-temperature plasma on galectin expression in the healing skin. We compared the effects of low-temperature plasma on the expression of galectin-1, -2, and -3 in the healing skin with those of electrocoagulation conducted with a high-frequency electrical coagulator. Immediately after the start of low-temperature plasma treatment following the incision made in the skin, a membrane-like structure was formed on the surface of the wound. Immunoelectron microscopy showed that these galectins were localized in the membrane-like structure of the plasma-treated skin. The expressions of these galectins were increased by the low-temperature plasma treatment, whereas they were inhibited by the electrocoagulation. These results suggest that galectins were involved in the wound healing of low-temperature plasma-treated skin. Galectins will thus be good markers for further examination of the effects of low-temperature plasma on the healing of wounded skin.

Airway epithelial repair in health and disease: Orchestrator or simply a player?

Epithelial cells represent the most important surface of contact in the body and form the first line of defence of the body to external environment. Consequently, epithelia have numerous roles in order to maintain a homeostatic defence barrier. Although the epithelium has been extensively studied over several decades, it remains the focus of new research, indicating a lack of understanding that continues to exist around these cells in specific disease settings. Importantly, evidence is emerging that airway epithelial cells in particular have varied complex functions rather than simple passive roles. One area of current interest is its role following injury. In particular, the epithelial-specific cellular mechanisms regulating their migration during wound repair remain poorly understood and remain an area that requires much needed investigation. A better understanding of the physiological, cellular and molecular wound repair mechanisms could assist in elucidating pathological processes that contribute to airway epithelial pathology. This review attempts to highlight migration-specific and cell-extracellular matrix (ECM) aspects of repair used by epithelial cells under normal and disease settings, in the context of human airways.

Pharmacological activation of estrogen receptors-α and -β differentially modulates keratinocyte differentiation with functional impact on wound healing

Estrogen deprivation is considered responsible for many age-related processes, including poor wound healing. Guided by previous observations that estradiol accelerates re‑epithelialization through estrogen receptor (ER)‑β, in the present study, we examined whether selective ER agonists [4,4',4''-(4-propyl [1H] pyrazole-1,3,5-triyl)‑trisphenol (PPT), ER‑α agonist; 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), ER‑β agonist] affect the expression of basic proliferation and differentiation markers (Ki‑67, keratin‑10, ‑14 and ‑19, galectin‑1 and Sox‑2) of keratinocytes using HaCaT cells. In parallel, ovariectomized rats were treated daily with an ER modulator, and wound tissue was removed 21 days after wounding and routinely processed for basic histological analysis. Our results revealed that the HaCaT keratinocytes expressed both ER‑α and ‑β, and thus are well-suited for studying the effects of ER agonists on epidermal regeneration. The activation of ER‑α produced a protein expression pattern similar to that observed in the control culture, with a moderate expression of Ki‑67 being observed. However, the activation of ER‑β led to an increase in cell proliferation and keratin‑19 expression, as well as a decrease in galectin‑1 expression. Fittingly, in rat wounds treated with the ER‑β agonist (DPN), epidermal regeneration was accelerated. In the present study, we provide information on the mechanisms through which estrogens affect the expression patterns of selected markers, thus modulating keratinocyte proliferation and differentiation; in addition, we demonstrate that the pharmacological activation of ER-α and -β has a direct impact on wound healing.

Regulatory Impact of Amniotic Membrane Transplantation on Presence of Adhesion/Growth-Regulatory Galectins-1 and -7 in Corneal Explants from Acanthamoeba Keratitis Patients: Clinical Note

PURPOSE

To assess the impact of Acanthamoeba keratitis (AK) and amniotic membrane transplantation (AMT) in corneal explants on presence of two multifunctional endogenous lectins, i.e. galectins-1 and -7.

METHODS

Ten corneal explants from AK patients (five with previous AMT and five controls without this treatment) and seven specimens of disease-free control cornea were processed by indirect fluorescent immunohistochemistry.

RESULTS

Immunostaining for both galectins was obtained in the epithelium, stroma and the endothelial layer of all controls, with the strongest positivity in the epithelium. Significantly decreased intensity for galectin-1 was recorded in the epithelium of corneal explants from patients with AK and AMT. The signal for galectin-7 was significantly decreased in the epithelium of AK patients and normalized after AMT.

CONCLUSIONS

AMT has a marked impact on presence of the two galectins in opposite directions, encouraging complete profiling for this family of endogenous effectors.

Soy and breast cancer: focus on angiogenesis

Epidemiological studies have revealed that high consumption of soy products is associated with low incidences of hormone-dependent cancers, including breast and prostate cancer. Soybeans contain large amounts of isoflavones, such as the genistein and daidzain. Previously, it has been demonstrated that genistein, one of the predominant soy isoflavones, can inhibit several steps involved in carcinogenesis. It is suggested that genistein possesses pleiotropic molecular mechanisms of action including inhibition of tyrosine kinases, DNA topoisomerase II, 5α-reductase, galectin-induced G2/M arrest, protein histidine kinase, and cyclin-dependent kinases, modulation of different signaling pathways associated with the growth of cancer cells (e.g., NF-κB, Akt, MAPK), etc. Moreover, genistein is also a potent inhibitor of angiogenesis. Uncontrolled angiogenesis is considered as a key step in cancer growth, invasion, and metastasis. Genistein was found to inhibit angiogenesis through regulation of multiple pathways, such as regulation of VEGF, MMPs, EGFR expressions and NF-κB, PI3-K/Akt, ERK1/2 signaling pathways, thereby causing strong antiangiogenic effects. This review focuses on the antiangiogenic properties of soy isoflavonoids and examines their possible underlying mechanisms.

Galectin-1 accelerates wound healing by regulating the neuropilin-1/Smad3/NOX4 pathway and ROS production in myofibroblasts

Myofibroblasts have a key role in wound healing by secreting growth factors and chemoattractants to create new substrates and proteins in the extracellular matrix. We have found that galectin-1, a β-galactose-binding lectin involved in many physiological functions, induces myofibroblast activation; however, the mechanism remains unclear. Here, we reveal that galectin-1-null (Lgals1(-/-)) mice exhibited a delayed cutaneous wound healing response. Galectin-1 induced myofibroblast activation, migration, and proliferation by triggering intracellular reactive oxygen species (ROS) production. A ROS-producing protein, NADPH oxidase 4 (NOX4), was upregulated by galectin-1 through the neuropilin-1/Smad3 signaling pathway in myofibroblasts. Subcutaneous injection of galectin-1 into wound areas accelerated the healing of general and pathological (streptozotocin-induced diabetes mellitus) wounds and decreased the mortality of diabetic mice with skin wounds. These findings indicate that galectin-1 is a key regulator of wound repair that has therapeutic potential for pathological or imperfect wound healing.

Microarray analysis of serum mRNA in patients with head and neck squamous cell carcinoma at whole-genome scale

With the increasing demand for noninvasive approaches in monitoring head and neck cancer, circulating nucleic acids have been shown to be a promising tool. We focused on the global transcriptome of serum samples of head and neck squamous cell carcinoma (HNSCC) patients in comparison with healthy individuals. We compared gene expression patterns of 36 samples. Twenty-four participants including 16 HNSCC patients (from 12 patients we obtained blood samples 1 year posttreatment) and 8 control subjects were recruited. The Illumina HumanWG-6 v3 Expression BeadChip was used to profile and identify the differences in serum mRNA transcriptomes. We found 159 genes to be significantly changed (Storey's P value <0.05) between normal and cancer serum specimens regardless of factors including p53 and B-cell lymphoma family members (Bcl-2, Bcl-XL). In contrast, there was no difference in gene expression between samples obtained before and after surgery in cancer patients. We suggest that microarray analysis of serum cRNA in patients with HNSCC should be suitable for refinement of early stage diagnosis of disease that can be important for development of new personalized strategies in diagnosis and treatment of tumours but is not suitable for monitoring further development of disease.

Towards scarless wound healing: a comparison of protein expression between human, adult and foetal fibroblasts

Proteins from human adult and foetal fibroblast cell lines were compared, focusing on those involved in wound healing. Proteins were separated through two-dimensional gel electrophoresis (2DE). Differences in protein spot intensity between the lineages were quantified through 3D gel scanning densitometry. Selected protein spots were excised, subjected to tryptic digests, prior to separation using HPLC with a linear ion trap mass spectrometer, and identified. Protein maps representing the proteomes from adult and foetal fibroblasts showed similar distributions but revealed differences in expression levels. Heat shock cognate 71 kDA protein, Tubulin alpha-1A chain, actin cytoplasmic-1, and neuron cytoplasmic protein were all expressed in significantly higher concentrations by foetal fibroblasts, nearly double those observed for their adult counterparts. Fructose bisphosphate aldolase A, Cofilin-1, Peroxiredoxin-1, Lactotransferrin Galectin-1, Profilin-1, and Calreticulin were expressed at comparatively higher concentrations by the adult fibroblasts. Significant differences in the expression levels of some proteins in human adult and foetal fibroblasts correlated with known differences in wound healing behaviour. This data may assist in the development of technologies to promote scarless wound healing and better functional tissue repair and regeneration.

Cyclic chalcone analogue KRP6 as a potent modulator of cell proliferation: an in vitro study in HUVECs

In the present investigation a novel series of chalcone analogues were synthesized and evaluated for their anti-proliferative activity in human umbilical vein endothelial cells (HUVECs). Among 14 tested compounds, chalcone analogue (E)-3-(2'-methoxybenzylidene)-4-chromanone (KRP6) exhibited the most potent activity with IC50 19 μM. Moreover, HUVECs exhibited divergent, even opposing concentration-dependent responses to KRP6. This compound was the most potent inhibitor of cell proliferation and extracellular matrix formation (fibronectin and type IV collagen) at higher concentrations (20-50 μM). In contrast, KRP6 stimulated the compensatory increase in proliferative activity including extracellular matrix formation at low concentrations (1, 10 μM). KRP6 concentration-dependently modulated phosphorylation of Akt and mitogen-activated protein kinases such as extracellular signal-regulated kinase-1/-2 and p38 kinase, suggesting that these pathways play a role in the effect mediated by this compound. In addition, we found a selective effect on activated endothelial cells, in particular with resting endothelial cells. In conclusion, KRP6 is a potent modulator of selected steps of the angiogenic process in vitro. Accordingly, further in vivo research should be performed to facilitate its use in clinical practice.

Upregulation of IL-6, IL-8 and CXCL-1 production in dermal fibroblasts by normal/malignant epithelial cells in vitro: Immunohistochemical and transcriptomic analyses

BACKGROUND INFORMATION

Considering an analogy between wound healing and tumour progression, we studied chemokine and cytokine transcription and expression in normal fibroblasts by co-culture and in situ.

RESULTS

Whole-genome transcriptome profiling revealed strong upregulation for the interleukin (IL)-6, IL-8 and the chemokine CXCL-1 in in vitro co-cultures of normal fibroblasts with either normal or malignant epithelial cells compared to fibroblast cultures. The same ILs/chemokines were distinctly upregulated in clinical samples of squamous cell carcinoma when compared with paired normal mucosae. Analysis of culture supernatants showed that during the course of co-culture of the fibroblasts with the epithelial cells, IL-6, IL-8 and CXCL-1 were secreted to the culture medium. Experiments with addition of any of the proteins to the culture medium supported the notion that these ILs/chemokines strongly contributed to maintenance of a low-differentiation phenotype of epithelial cells, evaluated by the detection of keratin-8. Simultaneous addition of all factors increased the extent of the effect. These studies were extended by experiments with epithelial cells, either cultured in medium conditioned by preceding use for malignant keratinocytes without and in the presence of normal or cancer-associated fibroblasts or medium containing antibodies against IL-6, IL-8 and CXCL-1.

CONCLUSIONS

Our results indicate an analogy between wound healing and tumour growth, support the importance of epithelial-mesenchymal interaction in this model system and establish a potential bio-inspired anticancer therapy.

Novel potential interacting partners of fibronectin in spontaneous animal model of interstitial cystitis

Feline idiopathic cystitis (FIC) is the only spontaneous animal model for human interstitial cystitis (IC), as both possess a distinctive chronical and relapsing character. Underlying pathomechanisms of both diseases are not clearly established yet. We recently detected increased urine fibronectin levels in FIC cases. The purpose of this study was to gain further insight into the pathogenesis by assessing interacting partners of fibronectin in urine of FIC affected cats. Several candidate proteins were identified via immunoprecipitation and mass spectrometry. Considerable changes in FIC conditions compared to physiological expression of co-purified proteins were detected by Western blot and immunohistochemistry. Compared to controls, complement C4a and thioredoxin were present in higher levels in urine of FIC patients whereas loss of signal intensity was detected in FIC affected tissue. Galectin-7 was exclusively detected in urine of FIC cats, pointing to an important role of this molecule in FIC pathogenesis. Moderate physiological signal intensity of galectin-7 in transitional epithelium shifted to distinct expression in transitional epithelium under pathophysiological conditions. I-FABP expression was reduced in urine and urinary bladder tissue of FIC cats. Additionally, transduction molecules of thioredoxin, NF-κB p65 and p38 MAPK, were examined. In FIC affected tissue, colocalization of thioredoxin and NF-κB p65 could be demonstrated compared to absent coexpression of thioredoxin and p38 MAPK. These considerable changes in expression level and pattern point to an important role for co-purified proteins of fibronectin and thioredoxin-regulated signal transduction pathways in FIC pathogenesis. These results could provide a promising starting point for novel therapeutic approaches in the future.

Atropa Belladonna L. Water Extract: Modulator of Extracellular Matrix Formation in Vitro and in Vivo

Previously, we found that treatment of cutaneous wounds with Atropa belladonna L. (AB) revealed shortened process of acute inflammation as well as increased tensile strength and collagen deposition in healing skin wounds (Gál et al. 2009). To better understand AB effect on skin wound healing male Sprague-Dawley rats were submitted to one round full thickness skin wound on the back. In two experimental groups two different concentrations of AB extract were daily applied whereas the control group remained untreated. For histological evaluation samples were removed on day 21 after surgery and stained for wide spectrum cytokeratin, collagen III, fibronectin, galectin-1, and vimentin. In addition, in the in vitro study different concentration of AB extract were used to evaluate differences in HaCaT keratinocytes proliferation and differentiation by detection of Ki67 and keratin-19 expressions. Furthermore, to assess ECM formation of human dermal fibroblasts on the in vitro level fibronectin and galectin-1 were visualized. Our study showed that AB induces fibronectin and galectin-1 rich ECM formation in vitro and in vivo. In addition, the proliferation of keratinocytes was also increased. In conclusion, AB is an effective modulator of skin wound healing. Nevertheless, further research is needed to find optimal therapeutic concentration and exact underlying mechanism of action.

Psoriasis in humans is associated with down-regulation of galectins in dendritic cells

We have investigated the expression and role of galectin-1 and other galectins in psoriasis and in the Th1/Th17 effector and dendritic cell responses associated with this chronic inflammatory skin condition. To determine differences between psoriasis patients and healthy donors, expression of galectins was analysed by RT-PCR in skin samples and on epidermal and peripheral blood dendritic cells by immunofluorescence and flow cytometry. In the skin of healthy donors, galectin-1, -3 and -9 were expressed in a high proportion of Langerhans cells. Also, galectins were differentially expressed in peripheral blood dendritic cell subsets; galectin-1 and galectin-9 were highly expressed in peripheral myeloid dendritic cells compared with plasmacytoid dendritic cells. We found that non-lesional as well as lesional skin samples from psoriasis patients had low levels of galectin-1 at the mRNA and protein levels, in parallel with low levels of IL-10 mRNA compared with skin from healthy patients. However, only lesional skin samples expressed high levels of Th1/Th17 cytokines. The analysis of galectin-1 expression showed that this protein was down-regulated in Langerhans cells and dermal dendritic cells as well as in peripheral blood CD11c(+) DCs from psoriasis patients. Expression of galectin-1 correlated with IL-17 and IL-10 expression and with the psoriasis area and index activity. Addition of galectin-1 to co-cultures of human monocyte-derived dendritic cells with autologous T lymphocytes from psoriasis patients attenuated the Th1 response. Conversely, blockade of galectin binding increased IFNγ production and inhibited IL-10 secretion in co-cultures of monocyte-derived dendritic cells with CD4(+) T cells. Our results suggest a model in which galectin-1 down-regulation contributes to the exacerbation of the Th1/Th17 effector response in psoriasis patients.

Open Wound Healing In Vivo: Monitoring Binding and Presence of Adhesion/Growth-Regulatory Galectins in Rat Skin during the Course of Complete Re-Epithelialization

Galectins are a family of carbohydrate-binding proteins that modulate inflammation and immunity. This functional versatility prompted us to perform a histochemical study of their occurrence during wound healing using rat skin as an in vivo model. Wound healing is a dynamic process that exhibits three basic phases: inflammation, proliferation, and maturation. In this study antibodies against keratins-10 and -14, wide-spectrum cytokeratin, vimentin, and fibronectin, and non-cross-reactive antibodies to galectins-1, -2, and -3 were applied to frozen sections of skin specimens two days (inflammatory phase), seven days (proliferation phase), and twenty-one days (maturation phase) after wounding. The presence of binding sites for galectins-1, -2, -3, and -7 as a measure for assessing changes in reactivity was determined using labeled proteins as probes. Our study detected a series of alterations in galectin parameters during the different phases of wound healing. Presence of galectin-1, for example, increased during the early phase of healing, whereas galectin-3 rapidly decreased in newly formed granulation tissue. In addition, nuclear reactivity of epidermal cells for galectin-2 occurred seven days post-trauma. The dynamic regulation of galectins during re-epithelialization intimates a role of these proteins in skin wound healing, most notably for galectin-1 increasing during the early phases and galectin-3 then slightly increasing during later phases of healing. Such changes may identify a potential target for the development of novel drugs to aid in wound repair and patients’ care.

Secreted proteome of the murine multipotent hematopoietic progenitor cell line DKmix

Administration of the multipotent hematopoietic progenitor cell (HPC) line DKmix improved cardiac function after myocardial infarction and accelerated dermal wound healing due to paracrine mechanisms. The aim of this study was to analyse the secreted proteins of DKmix cells in order to identify the responsible paracrine factors and assess their relevance to the wide spectrum of therapeutic effects. A mass spectrometry (MS)-based approach was used to identify secreted proteins of DKmix cells. Serum free culture supernatants of DKmix-conditioned medium were collected and the proteins present were separated, digested by trypsin and the resulting peptides were then analyzed by matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) MS. Overall 95 different proteins were identified. Among them, secretory proteins galectin-3 and gelsolin were identified. These proteins are known to stimulate cell migration and influence wound healing and cardiac remodelling. The remaining proteins originate from intracellular compartments like cytoplasm (69%), nucleus (12%), mitochondria (4%), and cytoplasmic membrane (3%) indicating permeable or leaky DKmix cells in the conditioned medium. Additionally, a sandwich immunoassay was used to detect and quantify cytokines and chemokines. Interleukin-6 (IL-6), interleukin-13 (IL-13), monocyte-chemoattractant protein-1 (MCP-1), monocyte-chemoattractant protein-3 (MCP-3), monocyte-chemoattractant protein-1alpha (MIP-1alpha) and monocyte-chemoattractant protein-1beta (MIP-1beta) were detected in low concentrations. This study identified a subset of proteins present in the DKmix-conditioned medium that act as paracrine modulators of tissue repair. Moreover, it suggests that DKmix-derived conditioned medium might have therapeutic potency by promoting tissue regeneration.

Head and neck squamous cancer stromal fibroblasts produce growth factors influencing phenotype of normal human keratinocytes

Epithelial-mesenchymal interaction between stromal fibroblasts and cancer cells influences the functional properties of tumor epithelium, including the tumor progression and spread. We compared fibroblasts prepared from stroma of squamous cell carcinoma and normal dermal fibroblasts concerning their biological activity toward normal keratinocytes assessed by immunocytochemistry and profiling of gene activation for growth factors/cytokines by microarray chip technology. IGF-2 and BMP-4 were determined as candidate factors responsible for tumor-associated fibroblast activity that influences normal epithelia. This effect was confirmed by addition of recombinant IGF-2 and BMP4, respectively, to the culture medium. This hypothesis was also verified by inhibition experiments where blocking antibodies were employed in the medium conditioned by cancer-associated fibroblast. Presence of these growth factors was also detected in tumor samples.

Mechanisms mediating the vesicant actions of sulfur mustard after cutaneous exposure

Sulfur mustard (SM), a chemical weapon first employed during World War I, targets the skin, eyes, and lung. It remains a significant military and civilian threat. The characteristic response of human skin to SM involves erythema of delayed onset, followed by edema with inflammatory cell infiltration, the appearance of large blisters in the affected area, and a prolonged healing period. Several in vivo and in vitro models have been established to understand the pathology and investigate the mechanism of action of this vesicating agent in the skin. SM is a bifunctional alkylating agent which reacts with many targets including lipids, proteins, and DNA, forming both intra- and intermolecular cross-links. Despite the relatively nonselective chemical reactivity of this agent, basal keratinocytes are more sensitive, and blistering involves detachment of these cells from their basement membrane adherence zones. The sequence and manner in which these cells die and detach is still unresolved. Much has been discovered over the past two decades with respect to the mechanisms of SM-induced cytotoxicity and the intracellular and extracellular targets of this vesicant. In this review, the effects of SM exposure on the skin are described, as well as potential mechanisms mediating its actions. Successful therapy for SM poisoning will depend on following new mechanistic leads to develop drugs that target one or more of its sites of action.