Gayle M. Gordillo

Mixed-Species Biofilm Compromises Wound Healing by Disrupting Epidermal Barrier Function

In chronic wounds, biofilm infects host tissue for extended periods of time. This work establishes the first chronic preclinical model of wound biofilm infection aimed at addressing the long‐term host response. Although biofilm‐infected wounds did not show marked differences in wound closure, the repaired skin demonstrated compromised barrier function. This observation is clinically significant, because it leads to the notion that even if a biofilm infected wound is closed, as observed visually, it may be complicated by the presence of failed skin, which is likely to be infected and/or further complicated postclosure. Study of the underlying mechanisms recognized for the first time biofilm‐inducible miR‐146a and miR‐106b in the host skin wound‐edge tissue. These miRs silenced ZO‐1 and ZO‐2 to compromise tight junction function, resulting in leaky skin as measured by transepidermal water loss (TEWL). Intervention strategies aimed at inhibiting biofilm‐inducible miRNAs may be productive in restoring the barrier function of host skin. Copyright

Prostaglandin E2 Induces Oncostatin M Expression in Human Chronic Wound Macrophages through Axl Receptor Tyrosine Kinase Pathway

Monocytes and macrophages (mϕ) are plastic cells whose functions are governed by microenvironmental cues. Wound fluid bathing the wound tissue reflects the wound microenvironment. Current literature on wound inflammation is primarily based on the study of blood monocyte-derived macrophages, cells that have never been exposed to the wound microenvironment. We sought to compare pair-matched monocyte-derived macrophages with mϕ isolated from chronic wounds of patients. Oncostatin M (OSM) was differentially overexpressed in pair-matched wound mϕ. Both PGE2 and its metabolite 13,14-dihydro-15-keto-PGE2 (PGE-M) were abundant in wound fluid and induced OSM in wound-site mϕ. Consistently, induction of OSM mRNA was observed in mϕ isolated from PGE2-enriched polyvinyl alcohol sponges implanted in murine wounds. Treatment of human THP-1 cell-derived mϕ with PGE2 or PGE-M caused dose-dependent induction of OSM. Characterization of the signal transduction pathways demonstrated the involvement of EP4 receptor and cAMP signaling. In human mϕ, PGE2 phosphorylated Axl, a receptor tyrosine kinase (RTK). Axl phosphorylation was also induced by a cAMP analogue demonstrating interplay between the cAMP and RTK pathways. PGE2-dependent Axl phosphorylation led to AP-1 transactivation, which is directly implicated in inducible expression of OSM. Treatment of human mϕ or mice excisional wounds with recombinant OSM resulted in an anti-inflammatory response as manifested by attenuated expression of endotoxin-induced TNF-α and IL-1β. OSM treatment also improved wound closure during the early inflammatory phase of healing. In summary, this work recognizes PGE2 in the wound fluid as a potent inducer of mϕ OSM, a cytokine with an anti-inflammatory role in cutaneous wound healing.

Patient-Reported Outcomes 1 Year After Immediate Breast Reconstruction: Results of the Mastectomy Reconstruction Outcomes Consortium Study

Purpose The goals of immediate postmastectomy breast reconstruction are to minimize deformity and optimize quality of life as perceived by patients. We prospectively evaluated patient-reported outcomes (PROs) in women undergoing immediate implant-based or autologous reconstruction. Methods Women undergoing immediate postmastectomy reconstruction for invasive cancer and/or carcinoma in situ were enrolled at 11 sites. Women underwent implant-based or autologous tissue reconstruction. Patients completed the BREAST-Q, a condition-specific PRO measure for breast surgery patients, and Patient-Reported Outcomes Measurement Information System-29, a generic PRO measure, before and 1 year after surgery. Mean changes in PRO scores were summarized. Mixed-effects regression models were used to compare PRO scores across procedure types. Results In total, 1,632 patients (n = 1,139 implant, n = 493 autologous) were included; 1,183 (72.5%) responded to 1-year questionnaires. After analysis was controlled for baseline values, patients who underwent autologous reconstruction had greater satisfaction with their breasts than those who underwent implant-based reconstruction (difference, 6.3; P < .001), greater sexual well-being (difference, 4.5; P = .003), and greater psychosocial well-being (difference, 3.7; P = .02) at 1 year. Patients in the autologous reconstruction group had improved satisfaction with breasts (difference, 8.0; P = .002) and psychosocial well-being (difference, 4.6; P = .047) compared with preoperative baseline. Physical well-being of the chest was not fully restored in either the implant group (difference, -3.8; P = .001) or autologous group (-2.2; P = .04), nor was physical well-being of the abdomen in patients who underwent autologous reconstruction (-13.4; P < .001). Anxiety and depression were mitigated at 1 year in both groups. Compared with their baseline reports, patients who underwent implant reconstruction had decreased fatigue (difference, -1.4; P = .035), whereas patients who underwent autologous reconstruction had increased pain interference (difference, 2.0; P = .006). Conclusion At 1 year after mastectomy, patients who underwent autologous reconstruction were more satisfied with their breasts and had greater psychosocial and sexual well-being than those who underwent implant reconstruction. Although satisfaction with breasts was equal to or greater than baseline levels, physical well-being was not fully restored. This information can help patients better understand expected outcomes and may guide innovations to improve outcomes.

Dicer Knockdown Inhibits Endothelial Cell Tumor Growth via MicroRNA 21a-3p Targeting of Nox-4

Background: Endothelial cell tumors are the most common soft tissue tumor in infants. Results: Dicer knockdown up-regulated miR-21a-3p that targeted nox-4 mRNA preventing endothelial cell tumor formation in vivo. Conclusion: Nox-4 silencing inhibits endothelial cell tumor formation. Dicer knockdown up-regulates miR 21a-3p, which targets the Nox-4 3′-UTR. Significance: Novel drivers of endothelial cell tumor formation are reported. MicroRNAs (miR) are emerging as biomarkers and potential therapeutic targets in tumor management. Endothelial cell tumors are the most common soft tissue tumors in infants, yet little is known about the significance of miR in regulating their growth. A validated mouse endothelial cell (EOMA) tumor model was used to demonstrate that post-transcriptional gene silencing of dicer, the enzyme that converts pre-miR to mature miR, can prevent tumor formation in vivo. Tumors were formed in eight of eight mice injected with EOMA cells transfected with control shRNA but formed in only four of ten mice injected with EOMA cells transfected with dicer shRNA. Tumors that formed in the dicer shRNA group were significantly smaller than tumors in the control group. This response to dicer knockdown was mediated by up-regulated miR 21a-3p activity targeting the nox-4 3′-UTR. EOMA cells were transfected with miR 21a-3p mimic and luciferase reporter plasmids containing either intact nox-4 3′-UTR or with mutation of the proposed 3′-UTR miR21a-3p binding sites. Mean luciferase activity was decreased by 85% in the intact compared with the site mutated vectors (p < 0.01). Attenuated Nox-4 activity resulted in decreased cellular hydrogen peroxide production and decreased production of oxidant-inducible monocyte chemoattractant protein-1, which we have previously shown to be critically required for endothelial cell tumor formation. These findings provide the first evidence establishing the significance of dicer and microRNA in promoting endothelial cell tumor growth in vivo.

Computerized segmentation and measurement of chronic wound images

An estimated 6.5 million patients in the United States are affected by chronic wounds, with more than US

Multimodal imaging of cutaneous wound tissue

25 billion and countless hours spent annually for all aspects of chronic wound care. There is a need for an intelligent software tool to analyze wound images, characterize wound tissue composition, measure wound size, and monitor changes in wound in between visits. Performed manually, this process is very time-consuming and subject to intra- and inter-reader variability. In this work, our objective is to develop methods to segment, measure and characterize clinically presented chronic wounds from photographic images. The first step of our method is to generate a Red-Yellow-Black-White (RYKW) probability map, which then guides the segmentation process using either optimal thresholding or region growing. The red, yellow and black probability maps are designed to handle the granulation, slough and eschar tissues, respectively; while the white probability map is to detect the white label card for measurement calibration purposes. The innovative aspects of this work include defining a four-dimensional probability map specific to wound characteristics, a computationally efficient method to segment wound images utilizing the probability map, and auto-calibration of wound measurements using the content of the image. These methods were applied to 80 wound images, captured in a clinical setting at the Ohio State University Comprehensive Wound Center, with the ground truth independently generated by the consensus of at least two clinicians. While the mean inter-reader agreement between the readers varied between 67.4% and 84.3%, the computer achieved an average accuracy of 75.1%.

Endothelial cell tumor growth is Ape/ref-1 dependent

Abstract. Quantitative assessment of wound tissue ischemia, perfusion, and inflammation provides critical information for appropriate detection, staging, and treatment of chronic wounds. However, few methods are available for simultaneous assessment of these tissue parameters in a noninvasive and quantitative fashion. We integrated hyperspectral, laser speckle, and thermographic imaging modalities in a single-experimental setup for multimodal assessment of tissue oxygenation, perfusion, and inflammation characteristics. Algorithms were developed for appropriate coregistration between wound images acquired by different imaging modalities at different times. The multimodal wound imaging system was validated in an occlusion experiment, where oxygenation and perfusion maps of a healthy subject’s upper extremity were continuously monitored during a postocclusive reactive hyperemia procedure and compared with standard measurements. The system was also tested in a clinical trial where a wound of three millimeters in diameter was introduced on a healthy subject’s lower extremity and the healing process was continuously monitored. Our in vivo experiments demonstrated the clinical feasibility of multimodal cutaneous wound imaging.

Knowledge Management and Informatics Considerations for Comparative Effectiveness Research: A Case-driven Exploration

Tumor-forming endothelial cells have highly elevated levels of Nox-4 that release H2O2 into the nucleus, which is generally not compatible with cell survival. We sought to identify compensatory mechanisms that enable tumor-forming endothelial cells to survive and proliferate under these conditions. Ape-1/ref-1 (Apex-1) is a multifunctional protein that promotes DNA binding of redox-sensitive transcription factors, such as AP-1, and repairs oxidative DNA damage. A validated mouse endothelial cell (EOMA) tumor model was used to demonstrate that Nox-4-derived H2O2 causes DNA oxidation that induces Apex-1 expression. Apex-1 functions as a chaperone to keep transcription factors in a reduced state. In EOMA cells Apex-1 enables AP-1 binding to the monocyte chemoattractant protein-1 (mcp-1) promoter and expression of that protein is required for endothelial cell tumor formation. Intraperitoneal injection of the small molecule inhibitor E3330, which specifically targets Apex-1 redox-sensitive functions, resulted in a 50% decrease in tumor volume compared with mice injected with vehicle control (n = 6 per group), indicating that endothelial cell tumor proliferation is dependent on Apex-1 expression. These are the first reported results to establish Nox-4 induction of Apex-1 as a mechanism promoting endothelial cell tumor formation.

Cutaneous Imaging Technologies in Acute Burn and Chronic Wound Care.

Background: As clinical data are increasingly collected and stored electronically, their potential use for comparative effectiveness research (CER) grows. Despite this promise, challenges face those wishing to leverage such data. In this paper we aim to enumerate some of the knowledge management and informatics issues common to such data reuse. Design: After reviewing the current state of knowledge regarding biomedical informatics challenges and best practices related to CER, we then present 2 research projects at our institution. We analyze these and highlight several common themes and challenges related to the conduct of CER studies. Finally, we represent these emergent themes. Results: The informatics challenges commonly encountered by those conducting CER studies include issues related to data information and knowledge management (eg, data reuse, data preparation) as well as those related to people and organizational issues (eg, sociotechnical factors and organizational factors). Examples of these are described in further detail and a formal framework for describing these findings is presented. Conclusions: Significant challenges face researchers attempting to use often diverse and heterogeneous datasets for CER. These challenges must be understood in order to be dealt with successfully and can often be overcome with the appropriate use of informatics best practices. Many research and policy questions remain to be answered in order to realize the full potential of the increasingly electronic clinical data available for such research.

A clinician's guide to the treatment of foot burns occurring in diabetic patients

Background: Wound assessment relies on visual evaluation by physicians. Such assessment is largely subjective and presents the opportunity to explore the use of emergent technologies. Methods: Emergent and powerful noninvasive imaging technologies applicable to assess burn and chronic wounds are reviewed. Results: The need to estimate wound depth is critical in both chronic wound and burn injury settings. Harmonic ultrasound technology is powerful to study wound depth. It addresses the limitations of optical imaging with limited depth of penetration. What if a wound appears epithelialized by visual inspection, which shows no discharge yet is covered by repaired skin that lacks barrier function? In this case although the wound is closed as defined by current standards, it remains functionally open, presenting the risk of infection and other postclosure complications. Thus, assessment of skin barrier function is valuable in the context of assessing wound closure. Options for the study of tissue vascularization are many. If noncontact and noninvasive criteria are of importance, laser speckle imaging is powerful. Fluorescence imaging is standard in several clinical settings and is likely to serve the wound clinics well as long as indocyanine green injection is not of concern. A major advantage of harmonic ultrasound imaging of wound depth is that the same system is capable of providing information on blood flow dynamics in arterial perforators. Conclusion: With many productive imaging platforms to choose from, wound care is about to be transformed by technology that would help assess wound severity.