Tissue factor as a link between wounding and tissue repair

Epithelial-Cell-Derived Extracellular Vesicles in Pathophysiology of Epithelial Injury and Repair in Chronic Rhinosinusitis: Connecting Immunology in Research Lab to Biomarkers in Clinics

Epithelial barrier disruption and failure of epithelial repair by aberrant epithelial-mesenchymal transition (EMT)-induced basal cells observed in nasal mucosa of chronic rhinosinusitis (CRS) are speculated to play important roles in disease pathophysiology. Microparticles (MPs) are a type of extracellular vesicle (EV) released by budding or shedding from the plasma membrane of activated or apoptotic cells. MPs are detected in nasal lavage fluids (NLFs) and are now receiving attention as potential biomarkers to evaluate the degree of activation of immune cells and injury of structural cells in nasal mucosa of subjects with sinus disease. There are three types of epithelial-cell-derived MPs, which are defined by the expression of different epithelial specific markers on their surface: EpCAM, E-cadherin, and integrin β6 (ITGB6). When these markers are on MPs that are also carrying canonical EMT/mesenchymal markers (Snail (SNAI1); Slug (SNAI2); alpha-smooth muscle actin (αSMA, ACTA2)) or pro- and anti-coagulant molecules (tissue factor (TF); tissue plasminogen activator (tPA); plasminogen activator inhibitor-1 (PAI-1)), they provide insight as to the roles of epithelial activation for EMT or regulation of coagulation in the underlying disease. In this review, we discuss the potential of epithelial MPs as research tools to evaluate status of nasal mucosae of CRS patients in the lab, as well as biomarkers for management and treatment of CRS in the clinic.

Anti-inflammatory and wound healing potential of kirenol in diabetic rats through the suppression of inflammatory markers and matrix metalloproteinase expressions

Damaged lesion remedial is a devastating impediment of diabetes that escorts to noteworthy disease state, predominantly bottom end diseases. Herbal outputs have exposed to be effectual in managing skin abrasions. Kirenol is recognized to encourage angiogenesis, fibroblast propagation, and exposure of cytokines and development factors concerned in wound remedial. The current study is executed to appraise the wound curing action of kirenol in streptozotocin-persusded diabetic rats by macroscopic parameters, histopathological, enzymatic, and biomolecular methods. Proportion of injure disclosure and reduction was augmented in the kirenol managed group. Histopathological examination exposed declined inflammatory cell applicability and amplified production of fibroblasts, new blood vessels, and displacement of collagen subsequent to kirenol treatment. RT-PCR study displayed diminished concentration of NF-κB, COX-2, iNOS, MMP-2 and MMP-9 levels in reply to kirenol. In accordance with all above findings our present study indicates that kirenol upholds wound medicinal prospective in hyperglycemic circumstances and might be constructive as a dealing and management for unceasing lesions in diabetic patients.

Systematic review and meta-analysis of mouse models of diabetes-associated ulcers

Mouse models are frequently used to study diabetes-associated ulcers, however, whether these models accurately simulate impaired wound healing has not been thoroughly investigated. This systematic review aimed to determine whether wound healing is impaired in mouse models of diabetes and assess the quality of the past research. A systematic literature search was performed of publicly available databases to identify original articles examining wound healing in mouse models of diabetes. A meta-analysis was performed to examine the effect of diabetes on wound healing rate using random effect models. A meta-regression was performed to examine the effect of diabetes duration on wound healing impairment. The quality of the included studies was also assessed using two newly developed tools. 77 studies using eight different models of diabetes within 678 non-diabetic and 720 diabetic mice were included. Meta-analysis showed that wound healing was impaired in all eight models. Meta-regression suggested that longer duration of diabetes prior to wound induction was correlated with greater degree of wound healing impairment. Pairwise comparisons suggested that non-obese diabetic mice exhibited more severe wound healing impairment compared with db/db mice, streptozotocin-induced diabetic mice or high-fat fed mice at an intermediate stage of wound healing (p<0.01). Quality assessment suggested that the prior research frequently lacked incorporation of key clinically relevant characteristics. This systematic review suggested that impaired wound healing can be simulated in many different mouse models of diabetes but these require further refinement to become more clinically relevant.

Agents that Modulate Peritoneal Membrane Structure and Function

Extensive experience with chronic peritoneal dialysis has identified a series of functional and anatomical pathologic changes in the peritoneal membrane thought to be the result of repeated insults from bioincompatible solutions. Laboratory and clinical findings from recent investigations often conflict and are difficult to interpret due to variations in methodologies, animal models, study designs, and data analyses. The principal pathophysiologic mechanisms identified thus far are oxidative stress, inflammation, and their consequences. Many substances used to neutralize the action of these insults, prevent formation of toxic compounds, or directly alter solute and water transport to improve peritoneal membrane performance have been studied. We herein review the most promising of these substances or those that deserve attention because their use has contributed to better understanding of peritoneal pathophysiology. Most peritoneal solution additives have proved useless due to their toxicity and undesirable effects, ineffectiveness, or manufacturing limitations. A few substances deserve more attention, particularly those capable of restoring negatively charged membrane sites, those that somehow improve permselectivity, scavengers of oxidants, and advanced glycation end-product inhibitors and breakers. Recent publications on clinical experience with neutral pH, low glucose degradation product (GDP) peritoneal solutions, although few and preliminary, are most encouraging. The virtual elimination of GDPs in these novel solutions will probably preclude the need for GDP scavengers and inhibitors. Nonetheless, there is room for further significant improvement in solution biocompatibility and for compounds that may restore peritoneal function.

Asiaticoside nitric oxide gel accelerates diabetic cutaneous ulcers healing by activating Wnt/β-catenin signaling pathway

Diabetic ulcers, gangrene, local infections and other traumatic symptoms of wound healing are all directly related. Promoting the early healing of diabetic cutaneous ulcers (DCU) and reducing the disability and treatment costs is an important research project integrating traditional Chinese and Western medicine. Nitric oxide (NO) is a key component of wound healing, and endogenous NO secretion is insufficient during the development of DCU. It has been reported that exogenous NO can promote wound healing, but exogenous NO has a short half-life and is difficult to adhere to the skin. Asiaticoside (AC) is extracted from the traditional Chinese medicine Centella asiatica, and has angiogenic, anticancer, antioxidant, anti-inflammatory, and wound-healing effects. Therefore, our study is based on the hypothesis that the combination of AC and NO to treat DCU is possible. In this study we considered gels of AC and NO, and evaluated the effects of the gel on DCU healing. Based on our study, it was found that the combined effect of asiaticoside and NO could accelerate the healing rate of DCU wounds. The asiaticoside NO gel can inhibit the growth of bacteria in the wound surface, alleviate the inflammatory reaction of wound, and increase the expression of VEGF, iNOS, eNOS and CD34. Our research shows that asiaticoside NO gel may promote DCU wound healing by regulating Wnt/β-Catenin signaling pathway. It will provide new targets and strategies for the diagnosis and treatment of DCU.

Cutaneous Epithelial to Mesenchymal Transition Activator ZEB1 Regulates Wound Angiogenesis and Closure in a Glycemic Status-Dependent Manner

Epithelial to mesenchymal transition (EMT) and wound vascularization are two critical interrelated processes that enable cutaneous wound healing. Zinc finger E-box binding homeobox 1 (ZEB1), primarily studied in the context of tumor biology, is a potent EMT activator. ZEB1 is also known to contribute to endothelial cell survival as well as stimulate tumor angiogenesis. The role of ZEB1 in cutaneous wounds was assessed using Zeb1^+/- mice, as Zeb1^-/- mice are not viable. Quantitative stable isotope labeling by amino acids in cell culture (SILAC) proteomics was used to elucidate the effect of elevated ZEB1, as noted during hyperglycemia. Under different glycemic conditions, ZEB1 binding to E-cadherin promoter was investigated using chromatin immunoprecipitation. Cutaneous wounding resulted in loss of epithelial marker E-cadherin with concomitant gain of ZEB1. The dominant proteins downregulated after ZEB1 overexpression functionally represented adherens junction pathway. Zeb1^+/- mice exhibited compromised wound closure complicated by defective EMT and poor wound angiogenesis. Under hyperglycemic conditions, ZEB1 lost its ability to bind E-cadherin promoter. Keratinocyte E-cadherin, thus upregulated, resisted EMT required for wound healing. Diabetic wound healing was improved in ZEB^+/- as well as in db/db mice subjected to ZEB1 knockdown. This work recognizes ZEB1 as a key regulator of cutaneous wound healing that is of particular relevance to diabetic wound complication.

MicroRNA-411 and Its 5'-IsomiR Have Distinct Targets and Functions and Are Differentially Regulated in the Vasculature under Ischemia

MicroRNAs are posttranscriptional regulators of gene expression. As microRNAs can target many genes simultaneously, microRNAs can regulate complex multifactorial processes, including post-ischemic neovascularization, a major recovery pathway in cardiovascular disease. MicroRNAs select their target mRNAs via full complementary binding with their seed sequence, i.e., nucleotides 2-8 from the 5' end of a microRNA. The exact sequence of a mature microRNA, and thus of its 5' and 3' ends, is determined by two sequential cleavage steps of microRNA precursors, Drosha/DGCR8 and Dicer. When these cleavage steps result in nucleotide switches at the 5' end, forming a so-called 5'-isomiR, this results in a shift in the mature microRNA's seed sequence. The role of 5'-isomiRs in cardiovascular diseases is still unknown. Here, we characterize the expression and function of the 5'-isomiR of miR-411 (ISO-miR-411). ISO-miR-411 is abundantly expressed in human primary vascular cells. ISO-miR-411 has a different "targetome" from WT-miR-411, with only minor overlap. The ISO-miR-411/WT-miR-411 ratio is downregulated under acute ischemia, both in cells and a murine ischemia model, but is upregulated instead in chronically ischemic human blood vessels. ISO-miR-411 negatively influences vascular cell migration, whereas WT-miR-411 does not. Our data demonstrate that isomiR formation is a functional pathway that is actively regulated during ischemia.

Lupeol, a Dietary Triterpene, Enhances Wound Healing in Streptozotocin-Induced Hyperglycemic Rats with Modulatory Effects on Inflammation, Oxidative Stress, and Angiogenesis

Impaired wound healing is a debilitating complication of diabetes that leads to significant morbidity, particularly foot ulcers. Natural products have shown to be effective in treating skin wounds. Lupeol is known to stimulate angiogenesis, fibroblast proliferation, and expressions of cytokines and growth factors involved in wound healing. The study is performed to evaluate the wound healing activity of lupeol in streptozotocin-induced hyperglycemic rats by macroscopical, histological, immunohistochemical, immunoenzymatic, and molecular methods. Percentage of wound closure and contraction was increased in the lupeol-treated group when compared to the Lanette group. Histopathological observation revealed decreased inflammatory cell infiltration and increased proliferation of fibroblasts, vascularization, and deposition of collagen fibers after lupeol treatment. Immunohistochemical analyses showed decreased intensity of NF-κB and increased intensity of FGF-2, TGF-β1, and collagen III. ELISA results revealed downregulated IL-6 levels and upregulated IL-10 levels in response to lupeol. The mRNA expression levels of Hif-1α, Sod-2, and Ho-1 were significantly increased in response to lupeol as compared to Lanette whereas Nf-κb and Vegf-A levels were decreased in relation to insulin and lupeol treatment. These findings indicate that lupeol possesses wound healing potential in hyperglycemic conditions and may be useful as a treatment for chronic wounds in diabetic patients.

The Dynamics of the Skin's Immune System

The skin is a complex organ that has devised numerous strategies, such as physical, chemical, and microbiological barriers, to protect the host from external insults. In addition, the skin contains an intricate network of immune cells resident to the tissue, crucial for host defense as well as tissue homeostasis. In the event of an insult, the skin-resident immune cells are crucial not only for prevention of infection but also for tissue reconstruction. Deregulation of immune responses often leads to impaired healing and poor tissue restoration and function. In this review, we will discuss the defensive components of the skin and focus on the function of skin-resident immune cells in homeostasis and their role in wound healing.

Proteomic analysis reveals procoagulant properties of cigarette smoke-induced extracellular vesicles

Airway epithelial cells secrete extracellular vesicles (EVs) under basal conditions and when exposed to cigarette smoke extract (CSE). Getting insights into the composition of these EVs will help unravel their functions in homeostasis and smoking-induced pathology. Here, we characterized the proteomic composition of basal and CSE-induced airway epithelial EVs. BEAS-2B cells were left unexposed or exposed to 1% CSE for 24 h, followed by EV isolation using ultrafiltration and size exclusion chromatography. Isolated EVs were labelled with tandem mass tags and their proteomic composition was determined using nano-LC-MS/MS. Tissue factor (TF) activity was determined by a factor Xa generation assay, phosphatidylserine (PS) content by prothrombinase assay and thrombin generation using calibrated automated thrombogram (CAT). Nano-LC-MS/MS identified 585 EV-associated proteins with high confidence. Of these, 201 were differentially expressed in the CSE-EVs according to the moderated t-test, followed by false discovery rate (FDR) adjustment with the FDR threshold set to 0.1. Functional enrichment analysis revealed that 24 proteins of the pathway haemostasis were significantly up-regulated in CSE-EVs, including TF. Increased TF expression on CSE-EVs was confirmed by bead-based flow cytometry and was associated with increased TF activity. CSE-EVs caused faster and more thrombin generation in normal human plasma than control-EVs, which was partly TF-, but also PS-dependent. In conclusion, proteomic analysis allowed us to predict procoagulant properties of CSE-EVs which were confirmed in vitro. Cigarette smoke-induced EVs may contribute to the increased cardiovascular and respiratory risk observed in smokers.

Platelet glycoprotein VI and C-type lectin-like receptor 2 deficiency accelerates wound healing by impairing vascular integrity in mice

Platelets promote wound healing by forming a vascular plug and by secreting growth factors and cytokines. Glycoprotein (GP)VI and C-type lectin-like receptor (CLEC)-2 signal through a (hem)-immunoreceptor tyrosine-based activation motif, which induces platelet activation. GPVI and CLEC-2 support vascular integrity during inflammation in the skin through regulation of leukocyte migration and function, and by sealing sites of vascular damage. In this study, we investigated the role of impaired vascular integrity due to GPVI and/or CLEC-2 deficiency in wound repair using a full-thickness excisional skin wound model in mice. Transgenic mice deficient in both GPVI and CLEC-2 exhibited accelerated skin wound healing, despite a marked impairment in vascular integrity. The local and temporal bleeding in the skin led to greater plasma protein entry, including fibrinogen and clotting factors, was associated with increased fibrin generation, reduction in wound neutrophils and M1 macrophages, decreased level of tumor necrosis factor (TNF)-α, and enhanced angiogenesis at day 3 after injury. Accelerated wound healing was not due to developmental defects in CLEC-2 and GPVI double-deficient mice as similar results were observed in GPVI-deficient mice treated with a podoplanin-blocking antibody. The rate of wound healing was not altered in mice deficient in either GPVI or CLEC-2. Our results show that, contrary to defects in coagulation, bleeding following a loss of vascular integrity caused by platelet CLEC-2 and GPVI deficiency facilitates wound repair by increasing fibrin(ogen) deposition, reducing inflammation, and promoting angiogenesis.

Mitochondrial dynamics (fission and fusion) and collagen production in a rat model of diabetic wound healing treated by photobiomodulation: comparison of 904 nm laser and 850 nm light-emitting diode (LED)

OBJECTIVE

Mitochondrial dysfunction has been associated with the development of diabetes mellitus which is characterized by disorders of collagen production and impaired wound healing. This study analyzed the effects of photobiomodulation (PBM) mediated by laser and light-emitting diode (LED) on the production and organization of collagen fibers in an excisional wound in an animal model of diabetes, and the correlation with inflammation and mitochondrial dynamics.

METHODS

Twenty Wistar rats were randomized into 4 groups of 5 animals. Groups: (SHAM) a control non-diabetic wounded group with no treatment; (DC) a diabetic wounded group with no treatment; (DLASER) a diabetic wounded group irradiated by 904 nm pulsed laser (40 mW, 9500 Hz, 1 min, 2.4 J); (DLED) a diabetic wounded group irradiated by continuous wave LED 850 nm (48 mW, 22 s, 1.0 J). Diabetes was induced by injection with streptozotocin (70 mg/kg). PBM was carried out daily for 5 days followed by sacrifice and tissue removal.

RESULTS

Collagen fibers in diabetic wounded skin were increased by DLASER but not by DLED. Both groups showed increased blood vessels by atomic force microscopy. Vascular endothelial growth factor (VEGF) was higher and cyclooxygenase (COX2) was lower in the DLED group. Mitochondrial fusion was higher and mitochondrial fusion was lower in DLED compared to DLASER.

CONCLUSION

Differences observed between DLASER and DLED may be due to the pulsed laser and CW LED, and to the higher dose of laser. Regulation of mitochondrial homeostasis may be an important mechanism for PBM effects in diabetes.

Hesperidin, a plant flavonoid accelerated the cutaneous wound healing in streptozotocin-induced diabetic rats: Role of TGF-ß/Smads and Ang-1/Tie-2 signaling pathways

Background: Delayed wound healing is a diverse, multifactorial, complex and inter-related complication of diabetes resulting in significant clinical morbidity. Hesperidin possesses potent antidiabetic and wound healing activity.

Aim: To evaluate the potential of hesperidin against experimentally induced diabetes foot ulcers.

Methods: Diabetes was induced experimentally by streptozotocin (STZ, 55 mg/kg, i.p.) in Sprague Dawley rats (180-220 g) and wounds were created on the dorsal surface of the hind paw of rats. Hesperidin (25, 50 and 100 mg/kg, p.o.) was administered for 21 days after wound stabilization. Various biochemical, molecular and histopathological parameters were evaluated in wound tissue.

Results: STZ-induced decrease in body weight and increase in blood glucose, food, and water intake was significantly (p < 0.05) inhibited by hesperidin (50 and 100 mg/kg) treatment. It showed a significant increase (p < 0.05) in percent wound closure and serum insulin level. The STZ-induced decrease in SOD and GSH level, as well as elevated MDA and NO levels, were significantly (p < 0.05) attenuated by hesperidin (50 and 100 mg/kg) treatment. Intraperitoneal administration of STZ caused significant down-regulation in VEGF-c, Ang-1, Tie-2, TGF-β and Smad 2/3 mRNA expression in wound tissues whereas hesperidin (50 and 100 mg/kg) treatment showed significant up-regulation in these mRNA expressions. STZ-induced alteration in would architecture was also attenuated by hesperidin (50 and 100 mg/kg) treatment.

Conclusion: Together, treatment with hesperidin accelerate angiogenesis and vasculogenesis via up-regulation of VEGF-c, Ang-1/Tie-2, TGF-β and Smad-2/3 mRNA expression to enhance wound healing in chronic diabetic foot ulcers.

Heterodimers of the transcriptional factors NFATc3 and FosB mediate tissue factor expression for 15(S)-hydroxyeicosatetraenoic acid-induced monocyte trafficking

Tissue factor (TF) is expressed in vascular and nonvascular tissues and functions in several pathways, including embryonic development, inflammation, and cell migration. Many risk factors for atherosclerosis, including hypertension, diabetes, obesity, and smoking, increase TF expression. To better understand the TF-related mechanisms in atherosclerosis, here we investigated the role of 12/15-lipoxygenase (12/15-LOX) in TF expression. 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), the major product of human 15-LOXs 1 and 2, induced TF expression and activity in a time-dependent manner in the human monocytic cell line THP1. Moreover, TF suppression with neutralizing antibodies blocked 15(S)-HETE-induced monocyte migration. We also found that NADPH- and xanthine oxidase-dependent reactive oxygen species (ROS) production, calcium/calmodulin-dependent protein kinase IV (CaMKIV) activation, and interactions between nuclear factor of activated T cells 3 (NFATc3) and FosB proto-oncogene, AP-1 transcription factor subunit (FosB) are involved in 15(S)-HETE-induced TF expression. Interestingly, NFATc3 first induced the expression of its interaction partner FosB before forming the heterodimeric NFATc3-FosB transcription factor complex, which bound the proximal AP-1 site in the TF gene promoter and activated TF expression. We also observed that macrophages from 12/15-LOX-/- mice exhibit diminished migratory response to monocyte chemotactic protein 1 (MCP-1) and lipopolysaccharide compared with WT mouse macrophages. Similarly, compared with WT macrophages, monocytes from 12/15-LOX-/- mice displayed diminished trafficking, which was rescued by prior treatment with 12(S)-HETE, in a peritonitis model. These observations indicate that 15(S)-HETE-induced monocyte/macrophage migration and trafficking require ROS-mediated CaMKIV activation leading to formation of NFATc3 and FosB heterodimer, which binds and activates the TF promoter.

Effects of hyaluronic acid on bleeding following third molar extraction

Objective

To explore the effects of hyaluronic acid (HA) on bleeding and associated outcomes after third molar extraction.

Methods

Forty patients who had undergone molar extraction were randomly divided into two groups; 0.8% (w/v) HA was applied to the HA group (n=20) whereas a control group (n=20) was not treated. Salivary and gingival tissue factor (TF) levels, bleeding time, maximum interincisal opening (MIO), pain scored on a visual analog scale (VAS), and the swelling extent were compared between the two groups.

Results

HA did not significantly affect gingival TF levels. Salivary TF levels increased significantly 1 week after HA application but not in the control group. Neither the VAS pain level nor MIO differed significantly between the two groups. The swelling extent on day 3 and the bleeding time were greater in the HA group than in the control group.

Conclusions

Local injection of HA at 0.8% prolonged the bleeding time, and increased hemorrhage and swelling in the early postoperative period after third molar extractions.

Tissue Factor and Tissue Factor Pathway Inhibitor in the Wound-Healing Process After Neurosurgery

Objectives:

The aim of the study was to assess the concentrations of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the blood of patients with a postoperative wound after neurosurgery.

Method:

Participants included 20 adult patients who underwent neurosurgery because of degenerative spine changes. The concentration of TF and TFPI in the patients’ blood serum was measured 3 times: before surgery, during the first 24 hr after surgery, and between the 5th and 7th days after surgery. The control group comprised 20 healthy volunteers similar to the patient group with respect to gender and age.

Results:

A statistically significant difference was observed between TF concentration at all three measurement time points in the research group and TF concentration in the control group ( p = .018, p = .010, p = .001). A statistically significant difference was found between TFPI concentration at the second time point in the research group and TFPI concentration in the control group ( p = .041). No statistically significant within-subject difference was found between TF concentrations before and after surgery. A statistically significant within-subject difference was found between TFPI concentrations within 24 hr after surgery and 5–7 days after surgery ( p = .004).

Conclusion:

High perioperative concentrations of TF indicate not only the presence of thrombophilia but also the importance of TF in the wound-healing process. Perioperative changes in TFPI concentrations are related to its compensatory influence on hemostasis in thrombophilic conditions.

Tissue responses to postoperative laser therapy in diabetic rats submitted to excisional wounds

In a previous study about low-level laser therapy biomodulation on a full-thickness burn model we showed that single and fractionated dose regimens increased wound healing and leukocyte influx similarly when compared with untreated control. In order to verify if this finding would be similar in an impaired wound model, we investigated the effect of single and multiple irradiations on wound closure rate, type of inflammatory infiltrate, myofibroblasts, collagen deposition, and optical retardation of collagen in diabetic rats. Female Wistar rats in the same estrous cycle had diabetes induced with streptozotocin and an 8-mm excisional wound performed with a punch. The experimental groups were: control group--untreated ulcer; single-dose group--ulcer submitted to single dose of diode laser therapy (λ = 660 ± 2 nm; P = 30 mW; energy density: 4 J/cm2) and fractionated-dose group--ulcer submitted to 1 J/cm2 laser therapy on Days 1, 3, 8, and 10. The ulcers were photographed on the experimental days and after euthanasia tissue samples were routinely processed for histological and immunohistochemistry analyses. Independently of the energy density, laser therapy accelerated wound closure by approximately 40% in the first three days in comparison to the control group. Laser therapy increased acute inflammatory infiltrate until Day 3. Both laser groups exhibited more myofibroblasts and better collagen organization than the control group. The findings demonstrate that low-level laser therapy in the immediate postoperative period can enhance the tissue repair process in a diabetes model. Similar effects were achieved with laser therapy applied a single time with an energy density of 4 J/cm2 and applied four times with an energy density of 1 J/cm2. The application of laser therapy in the inflammatory phase was the most important factor to the enhancement of the tissue repair process.

Role of the protein C receptor in cancer progression

The hemostatic system plays pleiotropic roles in cancer progression by shaping the tumor microenvironment and metastatic niches through thrombin-dependent fibrin deposition and platelet activation. Expanding experimental evidence implicates coagulation protease receptors expressed by tumor cells as additional players that directly influence tumor biology. Pro-angiogenic G protein-coupled signaling of TF through protease activated receptor 2 and regulation of tumor cell and vascular integrins through ligation by alternative spliced TF are established pathways driving tumor progression. Our recent work shows that the endothelial protein C receptor (EPCR), a stem cell marker in hematopoietic, neuronal and epithelial cells, is also crucial for breast cancer growth in the orthotopic microenvironment of the mammary gland. In aggressive triple-negative breast cancer cells, EPCR expression is a characteristic of cancer stem cell-like populations that have tumor initiating properties in vivo. Blocking antibodies to EPCR attenuate in vivo tumor growth and proliferation specifically of EPCR(+) cells on defined integrin matrices in vitro. We also showed that tumor-associated macrophages are a source for upstream coagulation proteases that can activate TF- and EPCR-dependent cellular responses, suggesting that tumor cells utilize the tumor microenvironment for tumor promoting coagulation protease signaling.

Identification of a transcriptional signature for the wound healing continuum

There is a spectrum/continuum of adult human wound healing outcomes ranging from the enhanced (nearly scarless) healing observed in oral mucosa to scarring within skin and the nonhealing of chronic skin wounds. Central to these outcomes is the role of the fibroblast. Global gene expression profiling utilizing microarrays is starting to give insight into the role of such cells during the healing process, but no studies to date have produced a gene signature for this wound healing continuum. Microarray analysis of adult oral mucosal fibroblast (OMF), normal skin fibroblast (NF), and chronic wound fibroblast (CWF) at 0 and 6 hours post-serum stimulation was performed. Genes whose expression increases following serum exposure in the order OMF < NF < CWF are candidates for a negative/impaired healing phenotype (the dysfunctional healing group), whereas genes with the converse pattern are potentially associated with a positive/preferential healing phenotype (the enhanced healing group). Sixty-six genes in the enhanced healing group and 38 genes in the dysfunctional healing group were identified. Overrepresentation analysis revealed pathways directly and indirectly associated with wound healing and aging and additional categories associated with differentiation, development, and morphogenesis. Knowledge of this wound healing continuum gene signature may in turn assist in the therapeutic assessment/treatment of a patient's wounds.

Shedding light on a new treatment for diabetic wound healing: a review on phototherapy

Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI) or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP). In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing.

Aging-dependent reduction in glyoxalase 1 delays wound healing

Methylglyoxal (MG), the major dicarbonyl substrate of the enzyme glyoxalase 1 (GLO1), is a reactive metabolite formed via glycolytic flux. Decreased GLO1 activity in situ has been shown to result in an accumulation of MG and increased formation of advanced glycation endproducts, both of which can accumulate during physiological aging and at an accelerated rate in diabetes and other chronic degenerative diseases. To determine the physiological consequences which result from elevated MG levels and the role of MG and GLO1 in aging, wound healing in young (≤12 weeks) and old (≥52 weeks) wild-type mice was studied. Old mice were found to have a significantly slower rate of wound healing compared to young mice (74.9 ± 2.2 vs. 55.4 ± 1.5% wound closure at day 6; 26% decrease; p < 0.0001). This was associated with decreases in GLO1 transcription, expression and activity. The importance of GLO1 was confirmed in mice by inhibition of GLO1. Direct application of MG to the wounds of young mice, decreased wound healing by 24% compared to untreated mice, whereas application of BSA modified minimally by MG had no effect. Treatment of either young or old mice with aminoguanidine, a scavenger of free MG, significantly increased wound closure by 16% (66.8 ± 1.6 vs. 77.2 ± 3.1%; p < 0.05) and 64% (40.4 ± 7.9 vs. 66.4 ± 5.2%; p < 0.05), respectively, by day 6. As a result of the aminoguanidine treatment, the overall rate of wound healing in the old mice was restored to the level observed in the young mice. These findings were confirmed in vitro, as MG reduced migration and proliferation of fibroblasts derived from young and old, wild-type mice. The data demonstrate that the balance between MG and age-dependent GLO1 downregulation contributes to delayed wound healing in old mice.

ROS constitute a convergence nexus in the development of IGF1 resistance and impaired wound healing in a rat model of type 2 diabetes

An indolent non-healing wound and insulin and/or insulin-like growth factor (IGF1) resistance are cardinal features of diabetes, inflammation and hypercortisolemia. Little is known about why these phenomena occur in so many contexts. Do the various triggers that induce insulin and/or IGF1 resistance and retard wound healing act through a common mechanism? Cultured dermal fibroblasts from rats and full-thickness excisional wounds were used as models to test the premise that reactive oxygen species (ROS) play a causal role in the development of IGF1 resistance and impaired wound healing under different but pathophysiologically relevant clinical settings, including diabetes, dexamethasone-induced hypercortisolemia and TNFα-induced inflammation. In normal fibroblasts, IGF1 initiated a strong degree of phosphorylation of insulin receptor substrate 1 (IRS1) (Tyr612) and Akt (Ser473), concomitantly with increased PI3K activity. This phenomenon seemed to be attenuated in fibroblasts that had phenotypic features of diabetes, inflammation or hypercortisolemia. Notably, these cells also exhibited an increase in the activity of the ROS–phospho-JNK (p-JNK)–p-IRS1 (Ser307) axis. The above-mentioned defects were reflected functionally by attenuation in IGF1-dependent stimulation of key fibroblast functions, including collagen synthesis and cell proliferation, migration and contraction. The effects of IGF1 on glucose disposal and cutaneous wound healing were also impaired in diabetic or hypercortisolemic rats. The ROS suppressors EUK-134 and α-lipoic acid, or small interfering RNA (siRNA)-mediated silencing of JNK expression, restored IGF1 sensitivity both in vitro and in vivo, and also ameliorated the impairment in IGF1-mediated wound responses during diabetes, inflammation and hypercortisolemia. Our data advance the notion that ROS constitute a convergence nexus for the development of IGF1 resistance and impaired wound healing under different but pathophysiologically relevant clinical settings, with a proof of concept for the beneficial effect of ROS suppressors.

Tissue factor, blood coagulation, and beyond: an overview

Emerging evidence shows a broad spectrum of biological functions of tissue factor (TF). TF classical role in initiating the extrinsic blood coagulation and its direct thrombotic action in close relation to cardiovascular risks have long been established. TF overexpression/hypercoagulability often observed in many clinical conditions certainly expands its role in proinflammation, diabetes, obesity, cardiovascular diseases, angiogenesis, tumor metastasis, wound repairs, embryonic development, cell adhesion/migration, innate immunity, infection, pregnancy loss, and many others. This paper broadly covers seminal observations to discuss TF pathogenic roles in relation to diverse disease development or manifestation. Biochemically, extracellular TF signaling interfaced through protease-activated receptors (PARs) elicits cellular activation and inflammatory responses. TF diverse biological roles are associated with either coagulation-dependent or noncoagulation-mediated actions. Apparently, TF hypercoagulability refuels a coagulation-inflammation-thrombosis circuit in “autocrine” or “paracrine” fashions, which triggers a wide spectrum of pathophysiology. Accordingly, TF suppression, anticoagulation, PAR blockade, or general anti-inflammation offers an array of therapeutical benefits for easing diverse pathological conditions.

Lumican expression in diaphragm induced by mechanical ventilation

Background

Diaphragmatic dysfunction found in the patients with acute lung injury required prolonged mechanical ventilation. Mechanical ventilation can induce production of inflammatory cytokines and excess deposition of extracellular matrix proteins via up-regulation of transforming growth factor (TGF)-β1. Lumican is known to participate in TGF-β1 signaling during wound healing. The mechanisms regulating interactions between mechanical ventilation and diaphragmatic injury are unclear. We hypothesized that diaphragmatic damage by short duration of mechanical stretch caused up-regulation of lumican that modulated TGF-β1 signaling.

Methods

Male C57BL/6 mice, either wild-type or lumican-null, aged 3 months, weighing between 25 and 30 g, were exposed to normal tidal volume (10 ml/kg) or high tidal volume (30 ml/kg) mechanical ventilation with room air for 2 to 8 hours. Nonventilated mice served as control groups.

Results

High tidal volume mechanical ventilation induced interfibrillar disassembly of diaphragmatic collagen fiber, lumican activation, type I and III procollagen, fibronectin, and α-smooth muscle actin (α-SMA) mRNA, production of free radical and TGF-β1 protein, and positive staining of lumican in diaphragmatic fiber. Mechanical ventilation of lumican deficient mice attenuated diaphragmatic injury, type I and III procollagen, fibronectin, and α-SMA mRNA, and production of free radical and TGF-β1 protein. No significant diaphragmatic injury was found in mice subjected to normal tidal volume mechanical ventilation.

Conclusion

Our data showed that high tidal volume mechanical ventilation induced TGF-β1 production, TGF-β1-inducible genes, e.g., collagen, and diaphragmatic dysfunction through activation of the lumican.

Characterization of canine coagulation factor VII and its complex formation with tissue factor: canine-human cross-species compatibility

BACKGROUND

Canine models have been good predictors of efficacy of hemophilia treatments, including recombinant human coagulation factor (F)VIIa (hFVIIa). However, canine FVIIa and tissue factor (TF) have remained incompletely characterized.

OBJECTIVE

 To explore canine-human cross-species FVIIa-TF compatibility in order to strengthen the predictive value of canine models in research on FVIIa and TF.

METHODS

Canine FVIIa (cFVIIa) and canine TF((1-217)) [cTF((1-217))] were produced by recombinant techniques, and canine-human cross-species FVIIa-TF interactions were characterized in vitro.

RESULTS

 Recombinant cFVIIa and soluble cTF((1-217)) were produced and purified to homogeneity. hFVIIa and cFVIIa bound with comparably high affinities to cTF((1-217)) (K(D)=6.0±0.7 nm and K(D)=6.0±0.3 nm, respectively) and to cell surface-expressed cTF (K(D)=8.4±0.4 nm and K(D)=7.2±1.2 nm, for (125) I-labeled hFVIIa and cFVII, respectively). In contrast, cFVIIa bound to human TF (hTF) with decreased affinity, both in solution and on cell surfaces. The decreased binding resulted in reduced activity of cFVIIa in functional assays with hTF((1-209)) . In direct comparison, cFVIIa was more active than hFVIIa, both in the absence and the presence of cognate TF.

CONCLUSION

The present finding that hFVIIa binds to cTF essentially as it does to hTF substantiates the hypothesis that human FVIIa-TF biology can be reliably recapitulated in canine models on administration of hFVIIa to dogs.

Novel therapeutic strategies for acute lung injury induced by lung damaging agents: the potential role of growth factors as treatment options

The increasing threat from terrorism has brought attention to the possible use of toxic industrial compounds (TICs) and other lung-damaging agents as weapons against civilian populations. The way in which these agents could be used favours the development of generic countermeasures. Improved medical countermeasures would increase survivability and improve the quality of recovery of lung damaged casualties. It is evident that there is a dearth of therapeutic regimes available to treat those forms of lung damage that currently require intensive care management. It is quite possible that mass casualties from a terrorist incident or major industrial accident involving the release of large quantities of inhaled TICs would place a severe burden on already scarce intensive care facilities. The development of effective pharmacological approaches to assist the recovery of casualties suffering from acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) may improve the prognosis of such patients (which is currently poor) and would ideally be used as a means of preventing subjects from developing the pulmonary oedema characteristic of ALI/ARDS. Many promising candidate pharmacological treatments have been evaluated for the treatment of ALI/ARDS, but their clinical value is often debatable. Thus, despite improvements in ventilation strategies, pharmacological intervention for ALI/ARDS remains problematical. A new approach is clearly required for the treatment of patients with severely compromised lungs. Whilst the pathology of ALI/ARDS associated with exposure to a variety of agents is complex, numerous experimental studies suggest that generic therapeutic intervention directed at approaches that aim to upregulate repair of the damaged alveolar blood/air barrier of the lung may be of value, particularly with respect to chemical-induced injury. To this end, keratinocyte growth factor (KGF), epithelial growth factor (EGF) and basic fibroblast growth factor (bFGF) are emerging as the most important candidates. Hepatocyte growth factor (HGF) does not have epithelial specificity for lung tissue. However, the enhanced effects of combinations of growth factors, such as the synergistic effect of HGF upon vascular endothelial growth factor (VEGF)-mediated endothelial cell activity, and the combined effect of HGF and KGF in tissue repair should be investigated, particularly as the latter pair of growth factors are frequently implicated in processes associated with the repair of lung damage. Synergistic interactions also occur between trefoil factor family (TFF) peptides and growth factors such as EGF. TFF peptides are most likely to be of value as a short term therapeutic intervention strategy in stimulating epithelial spreading activities which allow damaged mucosal surfaces to be rapidly covered by epithelial cells.

Factor VII deficiency impairs cutaneous wound healing in mice

Skin keratinocytes express tissue factor (TF) and are highly associated with skin wound healing. Although it has been demonstrated that perivascular TF expression in granulation tissue formed after dermal injury is downregulated during healing, studies of the mechanism of factor (F) VII, a TF ligand, in skin wound healing are lacking. We reported the use of a dermal punch model to demonstrate that low-expressing FVII mice (approximately 1% of wild type [WT]) exhibited impaired skin wound healing compared with WT controls. These low-FVII mice showed defective reepithelialization and reduced inflammatory cell infiltration at wound sites. This attenuated reepithelialization was associated with diminished expression of the transcription factor early growth response 1 (Egr-1). In vitro, Egr-1 was shown to be essential for the FVIIa-induced regulation of keratinocyte migration and inflammation. Both Egr-1 upregulation and downstream inflammatory cytokine appearance in keratinocytes depended on FVIIa/TF/protease-activated receptor 2 (PAR-2)-induced signaling and did not require subsequent generation of FXa and thrombin. The participation of Egr-1 in FVIIa-mediated regulation of keratinocyte function was confirmed by use of Egr-1-deficient mice, wherein a significant delay in skin wound healing after injury was observed, relative to WT mice. The results from these studies demonstrate an in vivo mechanistic relationship between FVIIa, Egr-1 and the inflammatory response in keratinocyte function during the wound healing process.

Wound healing in hemophilia B mice and low tissue factor mice

Wound healing involves a number of physiologic mechanisms including coagulation, inflammation, formation of granulation tissue, and tissue remodeling. Coagulation with robust thrombin generation leading to fibrin formation is necessary for wound healing. It is less clear if there is a requirement for ongoing coagulation to support tissue remodeling. We have studied wound healing in mice with defects in both the initiation (low tissue factor) and propagation (hemophilia B) phases. In hemophilia B mice, dermal wound healing is delayed; this delay is associated with bleeding into the granulation tissue. Mice can be treated with replacement therapy (factor IX) or bypassing agents (factor VIIa) to restore thrombin generation. If treated just prior to wound placement, mice will have normal hemostasis in the first day of wound healing. As the therapeutic agents clear, the mice will revert to hemophilic state. If the primary role of coagulation in wound healing is to provide a stable platelet/fibrin plug that is loaded with thrombin, then treating hemophilic animals just prior to wound placement should restore normal wound healing. The results from this study did not support that hypothesis. Instead the results show that restoring thrombin generation only at the time of wound placement did not improve the delayed wound healing. In preliminary studies on low tissue factor mice, there also appears to be a delay in wound healing with evidence of bleeding into the granulation tissue. The current data suggests that ongoing coagulation function needs to be maintained to support a normal wound healing process.

Venous thromboembolism in malignant gliomas

Malignant gliomas are associated with a very high risk of venous thromboembolism (VTE). While many clinical risk factors have previously been described in brain tumor patients, the risk of VTE associated with newer anti-angiogenic therapies such as bevacizumab in these patients remains unclear. When VTE occurs in this patient population, concern regarding the potential for intracranial hemorrhage complicates management decisions regarding anticoagulation, and these patients have a worse prognosis than their VTE-free counterparts. Risk stratification models identifying patients at high risk of developing VTE along with predictive plasma biomarkers may guide the selection of eligible patients for primary prevention with pharmacologic thromboprophylaxis. Recent studies exploring disordered coagulation, such as increased expression of tissue factor (TF), and tumorigenic molecular signaling may help to explain the increased risk of VTE in patients with malignant gliomas.

Advanced glycoxidation products and impaired diabetic wound healing

Impaired wound healing is an important diabetic complication associated with increased morbidity and mortality. It appears to be the net result of micro- and macrovascular disease. Diabetic neuropathy and the resulting loss of protective sensation (LOPS) has been recognized as one of the major causes for delayed healing in diabetic foot ulcer patients. In addition, hyperglycemia and a number of hyperglycemia-related factors have been linked to impaired diabetic wound healing, including advanced glycation end products (AGE). A large body of evidence from in vitro and in vivo studies and also data from studies using anti-AGE agents, indicate that AGE may play a role in the pathogenesis of impaired diabetic wound healing. AGE affect the wound healing process either directly by their interference with a variety of components involved or indirectly through their association with diabetic neuropathy and/or angiopathy. However, further studies need to be performed, mostly clinical studies, to evaluate the exact role of AGE in the impaired diabetic wound healing, suggesting new therapeutic approaches.

Perivascular tissue factor is down-regulated following cutaneous wounding: implications for bleeding in hemophilia

Healing of skin wounds is delayed in hemophilia B (HB) mice. HB mice do not bleed excessively at wounding, yet rebleed hours to days later. Tissue factor (TF) expression is up-regulated by inflammatory cytokines and has been linked to angiogenesis. We hypothesized that impaired thrombin generation in HB leads to impaired TF expression following injury. Punch biopsies were placed on wild-type (WT) and HB mice. Tissues from wound sites were immunostained for TF. Blood vessels are normally surrounded by a coat of pericytes expressing TF. Surprisingly, within a day after wounding TF disappeared from around nearby vessels; returning after 8 days in WT and 10 days in HB mice. The granulation tissue filling the wound during healing also lacked TF around angiogenic vessels. Thus, perivascular TF expression is down-regulated during wound healing. This may prevent thrombosis of neovessels during angiogenesis but renders hemophiliacs vulnerable to hemorrhage during healing.

Impaired integration of endothelial progenitor cells in capillaries of diabetic wounds is reversible with vascular endothelial growth factor infusion

To understand impaired angiogenesis in diabetic wounds, polyvinyl tubes were implanted subcutaneously in rats to form a granulation tissue for 2 weeks and the granulation tissue was studied after inducing diabetes with streptozotocin. By 1 week of diabetes, the granulation tissue was bloody and thinner than controls, its medial layer was depleted of microvessels, and the surviving vessels appeared dehisced. Vascular endothelial growth factor (VEGF) in the diabetic granulation tissue was reduced by 50% compared with control granulation tissue. After 3 days of diabetes, the diabetic tissue showed a greater degree of apoptosis in the microvessels. Chemotactic factors [stromal cell-derived factor-1alpha and chemokine receptor-4 (CXCR-4)], responsible for attracting bone marrow cells, showed equal intensity in control and diabetic tissues. As expected, progenitor endothelial CD-34 cells were observed in abundance in both the control and the diabetic granulation tissues. However, although the CD-34-positive cells appeared mostly to be integrated in the blood vessels of the control tissue, fewer such cells were present in the blood vessels of the diabetic tissues, suggesting that CD-34 failed to integrate into new blood vessels. Infusion of VEGF in the granulation tissue of diabetic rats for 1 week resulted in complete prevention of the microvascular defect compared with the contralateral granulation tissue that showed the typical diabetic changes. It was concluded that diabetes causes reduction of VEGF in the wound, resulting in loss of blood vessels by apoptosis and possible failure of CD-34 cells to integrate into the vessel structure.

Posttranslationally modified proteins as mediators of sustained intestinal inflammation

Oxidative and carbonyl stress leads to generation of N(epsilon)-carboxymethyllysine-modified proteins (CML-mps), which are known to bind the receptor for advanced glycation end products (RAGE) and induce nuclear factor (NF)-kappaB-dependent proinflammatory gene expression. To determine the impact of CML-mps in vivo, RAGE-dependent sustained NF-kappaB activation was studied in resection gut specimens from patients with inflammatory bowel disease. Inflamed gut biopsy tissue demonstrated a significant up-regulation of RAGE and increased NF-kappaB activation. Protein extracts from the inflamed zones, but not from noninflamed resection borders, caused perpetuated NF-kappaB activation in cultured endothelial cells, which was mediated by CML-mps including CML-modified S100 proteins. The resulting NF-kappaB activation, lasting 5 days, was primarily inhibited by either depletion of CML-mps or by the addition of sRAGE, p44/42 and p38 MAPKinase-specific inhibitors. Consistently, CML-mps isolated from inflamed gut areas and rectally applied into mice caused NF-kappaB activation, increased proinflammatory gene expression, and histologically detectable inflammation in wild-type mice, but not in RAGE-/- mice. A comparable up-regulation of NF-kappaB and inflammation on rectal application of CML-mps was observed in IL-10-/- mice. Thus, CML-mps generated in inflammatory lesions have the capacity to elicit a RAGE-dependent intestinal inflammatory response.