Inflammatory proteins and neutrophil extracellular traps increase in burn blister fluid 24h after burn.

Burn wound blister fluid is a valuable matrix for understanding the biological pathways associated with burn injury. In this study, 152 blister fluid samples collected from paediatric burn wounds at three different hospitals were analysed using mass spectrometry proteomic techniques. The protein abundance profile at different days after burn indicated more proteins were associated with cellular damage/repair in the first 24 h, whereas after this point more proteins were associated with antimicrobial defence. The inflammatory proteins persisted at a high level in the blister fluid for more than 7 days. This may indicate that removal of burn blisters prior to two days after burn is optimal to prevent excessive or prolonged inflammation in the wound environment. Additionally, many proteins associated with the neutrophil extracellular trap (NET) pathway were increased after burn, further implicating NETs in the post-burn inflammatory response. NET inhibitors may therefore be a potential treatment to reduce post-burn inflammation and coagulation pathology and enhance burn wound healing outcomes.

Clinical correlates of pain in adults with hard-to-heal leg ulcers: a cross-sectional study.

OBJECTIVE: Pain is a complex symptom associated with hard-to-heal (chronic) leg ulcers that is often poorly managed. The objective of this study was to gain greater understanding by investigating relationships between physical and psychosocial factors, and pain severity in adults with hard-to-heal leg ulcers. METHOD: A secondary analysis of data collected for a longitudinal, observational study of adults with hard-to-heal leg ulcers was undertaken. Data were collected over a 24-week period, including variables relating to sociodemographics, clinical variables, medical status, health, ulcer and vascular histories, and psychosocial measures. Multiple linear regression modelling was used to determine the independent influences of these variables on pain severity, as measured with a Numerical Rating Scale (NRS). RESULTS: Of 142 participants who were recruited, 109 met the inclusion criteria for this study, of whom: 43.1% had venous ulcers; 41.3% had mixed ulcers; 7.3% had arterial ulcers; and 8.3% had ulcers from some other cause. The final model explained 37% (adjusted r2=0.370) of the variation in the pain NRS scores. Controlling for analgesic use, salbutamol use (p=0.005), clinical signs of infection (p=0.027) and ulcer severity (p=0.001) were significantly associated with increased pain, while the presence of diabetes (p=0.007) was significantly associated with a decrease in pain. CONCLUSION: Pain is a highly complex and pervasive symptom associated with hard-to-heal leg ulcers. Novel variables were identified as being associated with pain in this population. The model also included wound type as a variable; however, despite being significantly correlated to pain at the bivariate level of analysis, in the final model, the variable did not reach significance. Of the variables included in the model, salbutamol use was the second most significant. This is a unique finding that, to the authors' knowledge, has not been previously reported or studied. Further research is required to better understand these findings and pain in general.

An Exploratory Study Demonstrating That Salivary Cytokine Profiles Are Altered in Children With Small Area Thermal Injury.

Serum can be used to investigate changes in cytokine concentration following burn injury in children; however, for children receiving treatment in an outpatient setting, blood is not routinely collected and therefore cannot be used for monitoring. The aim of this study was to investigate the use of saliva as a noninvasive tool for predicting burn outcomes by measuring the concentration of salivary cytokines in children with small area burns. A multiplex cytokine assay was used to measure 17 cytokines in the saliva of pediatric patients with burns (n = 20) and healthy controls (n = 20). After the removal of cytokines that had >30% of samples below the assay lower detection limit, six cytokines including IL-1ß, IL-4, IL-7, IL-8, MCP-1, and TNFα were analyzed for association with burns. IL-1ß and IL-4 were found to be significantly elevated in the pediatric burn patients compared to healthy controls. Interestingly, IL-1ß was also significantly elevated in scald burns, compared to contact burns. In addition, biologically meaningful differences in cytokine concentration were identified in patients with different burn characteristics, which warrant further investigation. This exploratory study provides evidence that cytokines can be detected in the saliva of children and that salivary cytokine profiles differ between healthy controls and children with burns. Overall, this study demonstrates the value of saliva for the investigation of cytokines and its potential application in pediatric diagnostics, specifically in situations where blood collection is not appropriate.

Local burn wound environment versus systemic response: Comparison of proteins and metabolites.

In this study, paired blood plasma (BP) and blister fluid (BF) samples from five paediatric burn patients were analysed using mass spectrometry to compare their protein and metabolite composition. The relative quantification of proteins was achieved through a label-free data independent acquisition mode. The relative quantification of metabolites was achieved using a Shimadzu Smart Metabolite Database gas chromatography mass spectrometry (GCMS) targeted assay. In total, 562 proteins and 141 individual metabolites were identified in the samples. There was 81% similarity in the proteins present in the BP and BF, with 50 and 54 unique proteins found in each sample type respectively. BF contained keratinocyte proliferation-related proteins and blood plasma contained abundant blood clotting proteins and apolipoproteins. BF contained more carbohydrates and less alpha-hydroxy acid metabolites than the BP. In this study, there were unique proteins and metabolites in BF and BP which were reflective of the local wound environment and systemic environments respectively. The results from this study demonstrate that the biomolecule content of BF is mostly the same as blood, but it also contains information specific to the local wound environment.

A review of potential biomarkers for assessing physical and psychological trauma in paediatric burns.

Biological markers that evaluate physical healing as well as psychological impact of a burn are essential for effective treatment of paediatric burns. The objective of this review is to summarize the evidence supporting the use of biomarkers in children with burns. An extensive review of the literature was performed using PubMed. A total of 59 biomarkers were identified relating to burn presence, specifically relating to processes involved in inflammation, wound healing, growth and metabolism. In addition, biomarkers involved in the stress response cascade following a burn trauma were also identified. Although many biomarkers have been identified that are potentially associated with burn-related physical and psychological trauma, an understanding of burn biology is still lacking in children. We propose that future research in the field of children's burns should be conducted using broad screening methods for identifying potential biomarkers, examine the biological interactions of different biomarkers, utilize child-appropriate biological fluids such as urine or saliva, and include a range of different severity burns. Through further research, the biological response to burn injury may be fully realized and clinically relevant diagnostic tests and treatment therapies utilizing these biomarkers could be developed, for the improvement of healing outcomes in paediatric burn patients.

Effect of fibronectin, FGF-2, and BMP4 in the stemness maintenance of BMSCs and the metabolic and proteomic cues involved.

BACKGROUND: Growing evidence suggests that the pluripotent state of mesenchymal stem cells (MSCs) relies on specific local microenvironmental cues such as adhesion molecules and growth factors. Fibronectin (FN), fibroblast growth factor 2 (FGF2), and bone morphogenetic protein 4 (BMP4) are the key players in the regulation of stemness and lineage commitment of MSCs. Therefore, this study was designed to investigate the pluripotency and multilineage differentiation of bone marrow-derived MSCs (BMSCs) with the introduction of FN, FGF-2, and BMP4 and to identify the metabolic and proteomic cues involved in stemness maintenance. METHODS: To elucidate the stemness of BMSCs when treated with FN, FGF-2, and BMP4, the pluripotency markers of OCT4, SOX2, and c-MYC in BMSCs were monitored by real-time PCR and/or western blot. The nuclear translocation of OCT4, SOX2, and c-MYC was investigated by immunofluorescence staining. Multilineage differentiation of the treated BMSCs was determined by relevant differentiation markers. To identify the molecular signatures of BMSC stemness, gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and bioinformatics analysis were utilized to determine the metabolite and protein profiles associated with stem cell maintenance. RESULTS: Our results demonstrated that the expression of stemness markers decreased with BMSC passaging, and the manipulation of the microenvironment with fibronectin and growth factors (FGF2 and BMP4) can significantly improve BMSC stemness. Of note, we revealed 7 differentially expressed metabolites, the target genes of these metabolites may have important implications in the maintenance of BMSCs through their effects on metabolic activity, energy production, and potentially protein production. We also identified 21 differentially abundant proteins, which involved in multiple pathways, including metabolic, autophagy-related, and signaling pathways regulating the pluripotency of stem cells. Additionally, bioinformatics analysis comfirned the correlation between metabolic and proteomic profiling, suggesting that the importance of metabolism and proteome networks and their reciprocal communication in the preservation of stemness. CONCLUSIONS: These results indicate that the culture environment supplemented with the culture cocktail (FN, FGF2, and BMP4) plays an essential role in shaping the pluripotent state of BMSCs. Both the metabolism and proteome networks are involved in this process and the modulation of cell-fate decision making. All these findings may contribute to the application of MSCs for regenerative medicine.

The modulation of the burn wound environment by negative pressure wound therapy: Insights from the proteome.

Negative pressure wound therapy has been used to promote wound healing in a variety of settings, including as an adjunct to silver-impregnated dressings in the acute management of paediatric burns. Fluid aspirated by the negative pressure wound therapy system represents a potentially insightful research matrix for understanding the burn wound microenvironment and the intervention's biochemical mechanisms of action. The aim of this study was to characterize the proteome of wound fluid collected using negative pressure wound therapy from children with small-area thermal burns. Samples were obtained as part of a randomized controlled trial investigating the clinical efficacy of adjunctive negative pressure wound therapy. They were compared with blister fluid specimens from paediatric burn patients matched according to demographic and injury characteristics. Protein identification and quantification were performed via liquid chromatography tandem mass spectrometry and sequential window acquisition of all theoretical mass spectra data-independent acquisition. Proteins and biological pathways that were unique to or enriched in negative pressure wound therapy fluid samples were evaluated using principal components, partial least squares-discriminant, and gene ontology enrichment analyses. Eight viable samples of negative pressure wound therapy fluid were collected and analyzed with eight matched blister fluid samples. A total of 502 proteins were quantitatively profiled in the negative pressure wound therapy fluid, of which 444 (88.4%) were shared with blister fluid. Several proteins exhibited significant abundance differences between fluid types, with negative pressure wound therapy fluid showing a higher abundance of matrix metalloproteinase-9, arginase-1, low affinity immunoglobulin gamma Fc region receptor III-A, filamin-A, alpha-2-macroglobulin, and hemoglobin subunit alpha. The results lend support to the hypothesis that negative pressure wound therapy augments wound healing through the modulation of factors involved in the inflammatory response, granulation tissue synthesis, and extracellular matrix maintenance. Data are available via ProteomeXchange with identifier PXD023168.

An in vitro Reconstructed Human Skin Equivalent Model to Study the Role of Skin Integration Around Percutaneous Devices Against Bacterial Infection.

Percutaneous devices are a key technology in clinical practice, used to connect internal organs to external medical devices. Examples include prosthesis, catheters and electrical drivelines. Percutaneous devices breach the skin's natural barrier and create an entry point for pathogens, making device infections a widespread problem. Modification of the percutaneous implant surface to increase skin integration with the aim to reduce subsequent infection is attracting a great deal of attention. While novel surfaces have been tested in various in vitro models used to study skin integration around percutaneous devices, no skin model has been reported, for the study of bacterial infection around percutaneous devices. Here, we report the establishment of an in vitro human skin equivalent model for driveline infections caused by Staphylococcus aureus, the most common cause of driveline-related infections. Three types of mock drivelines manufactured using melt electrowriting (smooth or porous un-seeded and porous pre-seeded with human fibroblasts) were implanted in human skin constructs and challenged with S. aureus. Our results show a high and stable load of S. aureus in association with the skin surface and no signs of S. aureus-induced tissue damage. Furthermore, our results demonstrate that bacterial migration along the driveline surface occurs in micro-gaps caused by insufficient skin integration between the driveline and the surrounding skin consistent with clinical reports from explanted patient drivelines. Thus, the human skin-driveline infection model presented here provides a clinically-relevant and versatile experimental platform for testing novel device surfaces and infection therapeutics.

Comparative label-free mass spectrometric analysis of temporal changes in the skeletal muscle proteome after impact trauma in rats.

Proteomics offers the opportunity to identify and quantify many proteins and to explore how they correlate and interact with each other in biological networks. This study aimed to characterize changes in the muscle proteome during the destruction, repair, and early-remodeling phases after impact trauma in male Wistar rats. Muscle tissue was collected from uninjured control rats and rats that were euthanized between 6 h and 14 days after impact injury. Muscle tissue was analyzed using unbiased, data-independent acquisition LC-MS/MS. We identified 770 reviewed proteins in the muscle tissue, 296 of which were differentially abundant between the control and injury groups (P ≤ 0.05). Around 50 proteins showed large differences (≥10-fold) or a distinct pattern of abundance after injury. These included proteins that have not been identified previously in injured muscle, such as ferritin light chain 1, fibrinogen γ-chain, fibrinogen ß-chain, osteolectin, murinoglobulin-1, T-kininogen 2, calcium-regulated heat-stable protein 1, macrophage-capping protein, retinoid-inducible serine carboxypeptidase, ADP-ribosylation factor 4, Thy-1 membrane glycoprotein, and ADP-ribosylation factor-like protein 1. Some proteins increased between 6 h and 14 days, whereas other proteins increased in a more delayed pattern at 7 days after injury. Bioinformatic analysis revealed that various biological processes, including regulation of blood coagulation, fibrinolysis, regulation of wound healing, tissue regeneration, acute inflammatory response, and negative regulation of the immune effector process, were enriched in injured muscle tissue. This study advances the understanding of early muscle healing after muscle injury and lays a foundation for future mechanistic studies on interventions to treat muscle injury.

Mobilizing serum factors and immune cells through exercise to counteract age-related changes in cancer risk.

An increasing body of evidence suggests that age-related immune changes and chronic inflammation contribute to cancer development. Recognizing that exercise has protective effects against cancer, promotes immune function, and beneficially modulates inflammation with ageing, this review outlines the current evidence indicating an emerging role for exercise immunology in preventing and treating cancer in older adults. A specific focus is on data suggesting that muscle- derived cytokines (myokines) mediate anti-cancer effects through promoting immunosurveillance against tumourigenesis or inhibiting cancer cell viability. Previous studies suggested that the exercise-induced release of myokines and other endocrine factors into the blood increases the capacity of blood serum to inhibit cancer cell growth in vitro. However, little is known about whether this effect is influenced by ageing. Prostate cancer is the second most common cancer in men. We therefore examined the effects of serum collected before and after exercise from healthy young and older men on the metabolic activity of androgen-responsive LNCaP and androgen-unresponsive PC3 prostate cancer cells. Exercise-conditioned serum collected from the young group did not alter cell metabolic activity, whereas post-exercise serum (compared with pre-exercise serum) from the older men inhibited the metabolic activity of LNCaP cancer cells. Serum levels of candidate cancer-inhibitory myokines oncostatin M and osteonectin increased in both age groups following exercise. Serum testosterone increased only in the younger men postexercise, potentially attenuating inhibitory effects of myokines on the LNCaP cell viability. The data from our study and the evidence in this review suggest that mobilizing serum factors and immune cells may be a key mechanism of how exercise counteracts cancer in the older population.

Deep Sequencing MicroRNAs from Extracellular Membrane Vesicles Revealed the Association of the Vesicle Cargo with Cellular Origin.

Extracellular membrane vesicles (EVs) have emerged as potential candidates for diagnostics and therapeutics. We have previously reported that keratinocytes release three types of EVs into the extracellular environment. Importantly, those EVs contain a large number of microRNAs (miRNAs) as cargo. In this study, we examined the expression level of keratinocyte-derived EV miRNAs, their target genes and potential functions. Next generation sequencing results showed that over one hundred miRNAs in each EV subtype exhibited greater than 100 reads per million (RPM), indicating a relatively high abundance. Analysis of the miRNAs with the highest abundance revealed associations with different keratinocyte cell sources. For instance, hsa-miR-205 was associated with the HaCaT cells whereas hsa-miR-21, hsa-miR-203, hsa-miR-22 and hsa-miR-143 were associated with human primary dermal keratinocytes (PKCs). Additionally, functional annotation analysis of genes regulated by those miRNAs, especially with regard to biological processes, also revealed cell-type-specific associations with either HaCaTs or PKCs. Indeed, EV functional effects were related to their parental cellular origin; specifically, PKC-derived EVs influenced fibroblast migration whereas HaCaT-derived EVs did not. In addition, the data in this current study indicates that keratinocyte-derived EVs and/or their cargoes have potential applications for wound healing.

Improving skin integration around long-term percutaneous devices using fibrous scaffolds in a reconstructed human skin equivalent model.

The interface between synthetic percutaneous devices and skin is a common area for bacterial infection, which may ultimately result in failure of the device. Better integration of percutaneous devices with skin may help reduce infection rates due to the creation of a dermal seal. However, the mismatch in material and chemical properties of devices and skin presents a challenge for closing the dermal gap at the skin-device interface. Here, we have used a tissue engineering approach to tissue integration by creating a highly fibrous poly(ε-caprolactone) scaffold using melt electrowriting and seeding this with dermal fibroblasts, followed by maturation and insertion into a full-thickness defect made in an ex vivo skin model. The integration of seeded scaffolds was compared with controls including a non-seeded scaffold and a polymer tube with a smooth surface. Dermal fibroblast inclusion in the scaffold and epidermal upgrowth versus downgrowth/marsupialization around the device were used as measures of integration. Based on these measures, almost all pre-seeded scaffolds performed better than both the non-seeded scaffolds and smooth tubes. The hypothesis is that the fibroblasts act as a barrier to epithelial downward migration, and provide healthy tissue for nascent epidermal development.

Soluble adenylyl cyclase links Ca2+ entry to Ca2+/cAMP-response element binding protein (CREB) activation in vascular smooth muscle.

Ca2+-transcription coupling controls gene expression patterns that define vascular smooth muscle cell (VSMC) phenotype. Although not well understood this allows normally contractile VSMCs to become proliferative following vessel injury, a process essential for repair but which also contributes to vascular remodelling, atherogenesis and restenosis. Here we show that the Ca2+/HCO3--sensitive enzyme, soluble adenylyl cyclase (sAC), links Ca2+ influx in human coronary artery smooth muscle cells (hCASMCs) to 3',5'-cyclic adenosine monophosphate (cAMP) generation and phosphorylation of the transcription factor Ca2+/cAMP response element binding protein (CREB). Store-operated Ca2+ entry (SOCE) into hCASMCs expressing the FRET-based cAMP biosensor H187 induced a rise in cAMP that mirrored cytosolic [Ca2+]. SOCE also activated the cAMP effector, protein kinase A (PKA), as determined by the PKA reporter, AKAR4-NES, and induced phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and CREB. Transmembrane adenylyl cyclase inhibition had no effect on the SOCE-induced rise in cAMP, while sAC inhibition abolished SOCE-generated cAMP and significantly reduced SOCE-induced VASP and CREB phosphorylation. This suggests that SOCE in hCASMCs activates sAC which in turn activates the cAMP/PKA/CREB axis. sAC, which is insensitive to G-protein modulation but responsive to Ca2+, pH and ATP, may therefore act as an overlooked regulatory node in vascular Ca2+-transcription coupling.

Differences between national and international guidelines for the management of diabetic foot disease.

AIM: No studies have investigated if national guidelines to manage diabetic foot disease differ from international guidelines. This study aimed to compare guidelines of Western Pacific nations with the International Working Group on the Diabetic Foot (IWGDF) guidance documents. METHODS: The 77 recommendations in five chapters of the 2015 IWGDF guidance documents were used as the international gold standard reference. The IWGDF national representative(s) from 12 Western Pacific nations were invited to submit their nation's diabetic foot guideline(s). Four investigators rated information in the national guidelines as "similar," "partially similar," "not similar," or "different" when compared with IWGDF recommendations. National representative(s) reviewed findings. Disagreements in ratings were discussed until consensus agreement achieved. RESULTS: Eight of 12 nations (67%) responded: Australia, China, New Zealand, Taiwan, and Thailand provided national guidelines; Singapore provided the Association of Southeast Asian Nations guidelines; and Hong Kong and the Philippines advised no formal national diabetic foot guidelines existed. The six national guidelines included were 39% similar/partially similar, 58% not similar, and 2% different compared with the IWGDF recommendations. Within individual IWGDF chapters, the six national guidelines were similar/partially similar with 53% of recommendations for the IWGDF prevention chapter, 42% for wound healing, 40% for infection, 40% for peripheral artery disease, and 20% for offloading. CONCLUSIONS: National diabetic foot disease guidelines from a large and diverse region of the world showed limited similarity to recommendations made by international guidelines. Differences between recommendations may contribute to differences in national diabetic foot disease outcomes and burdens.

Characterization of the Blister Fluid Proteome for Pediatric Burn Classification.

Blister fluid (BF) is a novel and viable research matrix for burn injury study, which can reflect both systemic and local microenvironmental responses. The protein abundance in BF from different burn severities were initially observed using a 2D SDS-PAGE approach. Subsequently, a quantitative data independent acquisition (DIA) method, SWATH, was employed to characterize the proteome of pediatric burn blister fluid. More than 600 proteins were quantitatively profiled in 87 BF samples from different pediatric burn patients. These data were correlated with clinically assessed burn depth and time until complete wound re-epithelialization through several different statistical analyses. Several proteins from these analyses exhibited significant abundance change between different burn depth or re-epithelialization groups, and can be considered as potential biomarker candidates. Further gene ontology (GO) enrichment analysis of the significant proteins revealed the most significant burn related biological processes (BP) that are altered with burn depth, including homeostasis and oxygen transport. However, for wounds with re-epithelialization times more or less than 21 days, the significant GO annotations were related to enzyme activity. This quantitative proteomics investigation of burn BF may enable objective classification of burn wound severity and assist with clinical decision-making. Data are available via ProteomeXchange with identifier PXD011102.

Differential Expression of Keratinocyte-Derived Extracellular Vesicle Mirnas Discriminate Exosomes From Apoptotic Bodies and Microvesicles.

Extracellular vesicles (EVs) are mammalian cell-derived nano-scale structures enclosed by a lipid bilayer that were previously considered to be cell debris with little biological value. However, EVs are now recognized to possess biological function, acting as a packaging, transport and delivery mechanisms by which functional molecules (i.e., miRNAs) can be transferred to target cells over some distance. To examine the miRNA from keratinocyte-derived EVs, we isolated three distinct populations of EVs from both HaCaT and primary human keratinocytes (PKCs) and characterized their biophysical, biochemical and functional features by using microscopy, immunoblotting, nanoparticle tracking, and next generation sequencing. We identified 1,048; 906; and 704 miRNAs, respectively, in apoptotic bodies (APs), microvesicles (MVs) and exosomes (EXs) released from HaCaT, and 608; 506; and 622 miRNAs in APs, MVs and EXs released from PKCs. In which, there were 623 and 437 identified miRNAs common to three HaCaT-derived EVs and PKC-derived EVs, respectively. In addition, we found hundreds of exosomal miRNAs that were previously un-reported. Differences in the abundance levels of the identified EV miRNAs could discriminate between the three EV populations. These data contribute substantially to knowledge within the EV-identified miRNA database, especially with regard to keratinocyte-derived EV miRNA content.

Acute Effects of Nitrate-Rich Beetroot Juice on Blood Pressure, Hemostasis and Vascular Inflammation Markers in Healthy Older Adults: A Randomized, Placebo-Controlled Crossover Study.

Aging is associated with a vasoconstrictive, pro-coagulant, and pro-inflammatory profile of arteries and a decline in the bioavailability of the endothelium-derived molecule nitric oxide. Dietary nitrate elicits vasodilatory, anti-coagulant and anti-inflammatory effects in younger individuals, but little is known about whether these benefits are evident in older adults. We investigated the effects of 140 mL of nitrate-rich (HI-NI; containing 12.9 mmol nitrate) versus nitrate-depleted beetroot juice (LO-NI; containing ≤0.04 mmol nitrate) on blood pressure, blood coagulation, vascular inflammation markers, plasma nitrate and nitrite before, and 3 h and 6 h after ingestion in healthy older adults (five males, seven females, mean age: 64 years, age range: 57-71 years) in a randomized, placebo-controlled, crossover study. Plasma nitrate and nitrite increased 3 and 6 h after HI-NI ingestion (p < 0.05). Systolic, diastolic and mean arterial blood pressure decreased 3 h relative to baseline after HI-NI ingestion only (p < 0.05). The number of blood monocyte-platelet aggregates decreased 3 h after HI-NI intake (p < 0.05), indicating reduced platelet activation. The number of blood CD11b-expressing granulocytes decreased 3 h following HI-NI beetroot juice intake (p < 0.05), suggesting a shift toward an anti-adhesive granulocyte phenotype. Numbers of blood CD14++CD16⁺ intermediate monocyte subtypes slightly increased 6 h after HI-NI beetroot juice ingestion (p < 0.05), but the clinical implications of this response are currently unclear. These findings provide new evidence for the acute effects of nitrate-rich beetroot juice on circulating immune cells and platelets. Further long-term research is warranted to determine if these effects reduce the risk of developing hypertension and vascular inflammation with aging.

Molecular Aspects of Wound Healing and the Rise of Venous Leg Ulceration: Omics Approaches to Enhance Knowledge and Aid Diagnostic Discovery.

Chronic wounds, in particular venous leg ulcers (VLU), represent a substantial burden for economies, healthcare systems and societies worldwide. This burden is exacerbated by the recalcitrant nature of these wounds, despite best practice, evidence-based care, which substantially reduces the quality of life of patients. Furthermore, co-morbidities such as diabetes and cardiovascular disease within ageing populations further contribute to the increasing prevalence in developed countries. This review provides an overview of the literature concerning the cellular and molecular mechanisms of wound healing and aspects where this process fails, resulting in a chronic wound. VLU may arise from chronic venous disease, which presents with many clinical manifestations and can lead to a highly complex disease state. Efforts to comprehend this state using various omics based approaches have delivered some insight into the underlying biology of chronic wounds and revealed markers of differentiation at the genomic, transcriptomic, proteomic and metabolomic levels. Furthermore, this review outlines the array of analytical tools and approaches that have been utilised for capturing multivariate data at each of these molecular levels. Future developments in spatiotemporal analysis of wounds along with the integration of multiple omics datasets may provide much needed information on the key molecules that drive wound chronicity. Such biomarkers have the potential to be developed into clinically relevant diagnostic tools to aid in personalised wound management.

Association of Extracellular Membrane Vesicles with Cutaneous Wound Healing.

Extracellular vesicles (EVs) are membrane-enclosed vesicles that are released into the extracellular environment by various cell types, which can be classified as apoptotic bodies, microvesicles and exosomes. EVs have been shown to carry DNA, small RNAs, proteins and membrane lipids which are derived from the parental cells. Recently, several studies have demonstrated that EVs can regulate many biological processes, such as cancer progression, the immune response, cell proliferation, cell migration and blood vessel tube formation. This regulation is achieved through the release and transport of EVs and the transfer of their parental cell-derived molecular cargo to recipient cells. This thereby influences various physiological and sometimes pathological functions within the target cells. While intensive investigation of EVs has focused on pathological processes, the involvement of EVs in normal wound healing is less clear; however, recent preliminarily investigations have produced some initial insights. This review will provide an overview of EVs and discuss the current literature regarding the role of EVs in wound healing, especially, their influence on coagulation, cell proliferation, migration, angiogenesis, collagen production and extracellular matrix remodelling.

Incidence and risk factors for developing infection in patients presenting with uninfected diabetic foot ulcers.

OBJECTIVE: There is a paucity of research on patients presenting with uninfected diabetic foot ulcers (DFU) that go on to develop infection. We aimed to investigate the incidence and risk factors for developing infection in a large regional cohort of patients presenting with uninfected DFUs. METHODS: We performed a secondary analysis of data collected from a validated prospective state-wide clinical diabetic foot database in Queensland (Australia). Patients presenting for their first visit with an uninfected DFU to a Diabetic Foot Service in one of thirteen Queensland regions between January 2012 and December 2013 were included. Socio-demographic, medical history, foot disease history, DFU characteristics and treatment variables were captured at the first visit. Patients were followed until their DFU healed, or if their DFU did not heal for 12-months, to determine if they developed a foot infection in that period. RESULTS: Overall, 853 patients were included; mean(standard deviation) age 62.9(12.8) years, 68.0% male, 90.9% type 2 diabetes, 13.6% indigenous Australians. Foot infection developed in 342 patients for an overall incidence of 40.1%; 32.4% incidence in DFUs healed <3 months, 55.9% in DFUs healed between 3-12 months (p<0.05). Independent risk factors (Odds Ratio (95% confidence interval)) for developing infection were: DFUs healed between 3-12 months (2.3 (1.6-3.3)), deep DFUs (2.2 (1.2-3.9)), peripheral neuropathy (1.8 (1.1-2.9)), previous DFU history (1.7 (1.2-2.4)), foot deformity (1.4 (1.0-2.0)), female gender (1.5 (1.1-2.1)) and years of age (0.98 (0.97-0.99)) (all p<0.05). CONCLUSIONS: A considerable proportion of patients presenting with an uninfected DFU will develop an infection prior to healing. To prevent infection clinicians treating patients with uninfected DFUs should be particularly vigilant with those presenting with deep DFUs, previous DFU history, peripheral neuropathy, foot deformity, younger age, female gender and DFUs that have not healed by 3 months after presentation.