Macrophage transition from an inflammatory to reparative phenotype after tissue injury is controlled by epigenetic enzymes that regulate inflammatory gene expression. We have previously identified that the histone methyltransferase SETDB2 in macrophages drives tissue repair by repressing NF-κB-mediated inflammation. Complementary ATAC-Seq and RNA-Seq of wound macrophages isolated from mice deficient in SETDB2 in myeloid cells revealed that SETDB2 suppresses the inflammatory gene program by inhibiting chromatin accessibility at NF-κB-dependent gene promoters.
View Article and Find Full Text PDFImmune cell-mediated inflammation is important in normal tissue regeneration but can be pathologic in diabetic wounds. Limited literature exists on the role of CD4+ T cells in normal or diabetic wound repair; however, the imbalance of CD4+ Th17/Tregs has been found to promote inflammation in other diabetic tissues. Here, using human tissue and murine transgenic models, we identified that the histone methyltransferase Mixed-lineage-leukemia-1 (MLL1) directly regulates the Th17 transcription factor RORγ via an H3K4me3 mechanism and increases expression of Notch receptors and downstream Notch signaling.
View Article and Find Full Text PDFPlasmacytoid dendritic cells (pDCs) are first responders to tissue injury, where they prime naive T cells. The role of pDCs in physiologic wound repair has been examined, but little is known about pDCs in diabetic wound tissue and their interactions with naive CD4+ T cells. Diabetic wounds are characterized by increased levels of inflammatory IL-17A cytokine, partly due to increased Th17 CD4+ cells.
View Article and Find Full Text PDFMacrophage (Mφ) plasticity is critical for normal wound repair; however, in type 2 diabetic wounds, Mφs persist in a low-grade inflammatory state that prevents the resolution of wound inflammation. Increased NLRP3 inflammasome activity has been shown in diabetic wound Mφs; however, the molecular mechanisms regulating NLRP3 expression and activity are unclear. Here, we identified that diabetic wound keratinocytes induce Nlrp3 gene expression in wound Mφs through IL-1 receptor-mediated signaling, resulting in enhanced inflammasome activation in the presence of pathogen-associated molecular patterns and damage-associated molecular patterns.
View Article and Find Full Text PDFObjective: To determine macrophage-specific alterations in epigenetic enzyme function contributing to the development of abdominal aortic aneurysms (AAAs).
Background: AAA is a life-threatening disease, characterized by pathologic vascular remodeling driven by an imbalance of matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). Identifying mechanisms regulating macrophage-mediated extracellular matrix degradation is of critical importance to developing novel therapies.
Coronavirus-associated coagulopathy (CAC) is a morbid and lethal sequela of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. CAC results from a perturbed balance between coagulation and fibrinolysis and occurs in conjunction with exaggerated activation of monocytes/macrophages (MO/Mφs), and the mechanisms that collectively govern this phenotype seen in CAC remain unclear. Here, using experimental models that use the murine betacoronavirus MHVA59, a well-established model of SARS-CoV-2 infection, we identify that the histone methyltransferase mixed lineage leukemia 1 (MLL1/KMT2A) is an important regulator of MO/Mφ expression of procoagulant and profibrinolytic factors such as tissue factor (F3; TF), urokinase (PLAU), and urokinase receptor (PLAUR) (herein, "coagulopathy-related factors") in noninfected and infected cells.
View Article and Find Full Text PDFMacrophage plasticity is critical for normal tissue repair following injury. In pathologic states such as diabetes, macrophage plasticity is impaired, and macrophages remain in a persistent proinflammatory state; however, the reasons for this are unknown. Here, using single-cell RNA sequencing of human diabetic wounds, we identified increased JMJD3 in diabetic wound macrophages, resulting in increased inflammatory gene expression.
View Article and Find Full Text PDFWound repair following acute injury requires a coordinated inflammatory response. Type I IFN signaling is important for regulating the inflammatory response after skin injury. IFN-κ, a type I IFN, has recently been found to drive skin inflammation in lupus and psoriasis; however, the role of IFN-κ in the context of normal or dysregulated wound healing is unclear.
View Article and Find Full Text PDFMacrophages are white blood cells with diverse functions contributing to a healthy immune response as well as the pathogenesis of cancer, osteoarthritis, atherosclerosis, and obesity. Due to their pleiotropic and dynamic nature, tools for imaging and tracking these cells at scales spanning the whole body down to microns could help to understand their role in disease states. Here we report fluorescent and radioisotopic quantum dots (QDs) for multimodal imaging of macrophage cells , , and .
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2021
COVID-19 induces a robust, extended inflammatory "cytokine storm" that contributes to an increased morbidity and mortality, particularly in patients with type 2 diabetes (T2D). Macrophages are a key innate immune cell population responsible for the cytokine storm that has been shown, in T2D, to promote excess inflammation in response to infection. Using peripheral monocytes and sera from human patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a murine hepatitis coronavirus (MHV-A59) (an established murine model of SARS), we identified that coronavirus induces an increased Mφ-mediated inflammatory response due to a coronavirus-induced decrease in the histone methyltransferase, SETDB2.
View Article and Find Full Text PDFNon-healing wounds in Type 2 Diabetes (T2D) patients represent the most common cause of amputation in the US, with an associated 5-year mortality of nearly 50%. Our lab has examined tissue from both T2D murine models and human wounds in order to explore mechanisms contributing to impaired wound healing. Current published data in the field point to macrophage function serving a pivotal role in orchestrating appropriate wound healing.
View Article and Find Full Text PDFAbdominal aortic aneurysms (AAAs) are a life-threatening disease for which there is a lack of effective therapy preventing aortic rupture. During AAA formation, pathological vascular remodeling is driven by macrophage infiltration, and the mechanisms regulating macrophage-mediated inflammation remain undefined. Recent evidence suggests that an epigenetic enzyme, JMJD3, plays a critical role in establishing macrophage phenotype.
View Article and Find Full Text PDFObjective: The aim of this work is to formulate recommendations based on global expert consensus to guide the surgical community on the safe resumption of surgical and endoscopic activities.
Background: The COVID-19 pandemic has caused marked disruptions in the delivery of surgical care worldwide. A thoughtful, structured approach to resuming surgical services is necessary as the impact of COVID-19 becomes better controlled.
Macrophages are a primary immune cell involved in inflammation, and their cell plasticity allows for transition from an inflammatory to a reparative phenotype and is critical for normal tissue repair following injury. Evidence suggests that epigenetic alterations play a critical role in establishing macrophage phenotype and function during normal and pathologic wound repair. Here, we find in human and murine wound macrophages that cyclooxygenase 2/prostaglandin E2 (COX-2/PGE2) is elevated in diabetes and regulates downstream macrophage-mediated inflammation and host defense.
View Article and Find Full Text PDFChronic macrophage inflammation is a hallmark of type 2 diabetes (T2D) and linked to the development of secondary diabetic complications. T2D is characterized by excess concentrations of saturated fatty acids (SFA) that activate innate immune inflammatory responses, however, mechanism(s) by which SFAs control inflammation is unknown. Using monocyte-macrophages isolated from human blood and murine models, we demonstrate that palmitate (C16:0), the most abundant circulating SFA in T2D, increases expression of the histone demethylase, Jmjd3.
View Article and Find Full Text PDFMacrophages are critical for the initiation and resolution of the inflammatory phase of wound healing. In diabetes, macrophages display a prolonged inflammatory phenotype preventing tissue repair. TLRs, particularly TLR4, have been shown to regulate myeloid-mediated inflammation in wounds.
View Article and Find Full Text PDFObjective: Sepsis represents an acute life-threatening disorder resulting from a dysregulated host response. For patients who survive sepsis, there remains long-term consequences, including impaired inflammation, as a result of profound immunosuppression. The mechanisms involved in this long-lasting deficient immune response are poorly defined.
View Article and Find Full Text PDFInterferon induced transmembrane proteins (IFITMs) found in vertebrates restrict infections by specific viruses. IFITM3 is known to be essential for restriction of influenza virus infections in both mice and humans. Vertebrate IFITMs are hypothesized to have derived from a horizontal gene transfer from bacteria to a primitive unicellular eukaryote.
View Article and Find Full Text PDFBackground & Aims: Transoral esophagogastric fundoplication (TF) can decrease or eliminate features of gastroesophageal reflux disease (GERD) in some patients whose symptoms persist despite proton pump inhibitor (PPI) therapy. We performed a prospective, sham-controlled trial to determine if TF reduced troublesome regurgitation to a greater extent than PPIs in patients with GERD.
Methods: We screened 696 patients with troublesome regurgitation despite daily PPI use with 3 validated GERD-specific symptom scales, on and off PPIs.
Surg Laparosc Endosc Percutan Tech
October 2012
Esophageal cancer remains one of the most deadly cancers with a low overall 5-year survival rate of 17%. Surgical options for esophageal cancer are varied, and debate exists on the best option. The literature was searched for articles discussing minimally invasive esophagectomy (MIE) compared with open esophagectomy (OE), and articles were chosen at the discretion of the authors.
View Article and Find Full Text PDFPurpose: Studies of endoscopic application of radiofrequency energy to the lower esophageal sphincter for gastroesophageal reflux control have produced conflicting reports of its effectiveness. This study aimed to conduct a meta-analysis of randomized controlled trials and cohort studies to assess the impact of this treatment.
Methods: Twenty studies were included.
Background: It remains important to determine the risk of bacterial contamination and infectious complications of the peritoneal cavity as it pertains to transgastric natural orifice translumenal endoscopic surgery (NOTES) procedures. The infectious implications of such procedures have been quantified in animal models. This report discusses the infectious risks of transgastric endoscopic peritoneoscopy (TEP) in a human clinical trial.
View Article and Find Full Text PDFThe Stretta procedure (radiofrequency energy application to the lower esophageal sphincter) is a unique endoluminal technique for the management of gastroesophageal reflux. This article reports on the long-term effectiveness of the Stretta procedure in patients with significant gastroesophageal reflux disease (GERD) referred to a surgical practice. Patients who underwent Stretta with a minimum of 36 months follow-up were included.
View Article and Find Full Text PDFBackground: Human and animal laboratory studies have shown that stress delays healing of standardized punch biopsy wounds.
Purpose: This 5-week prospective study of 17 women who underwent elective gastric bypass surgery addressed the association between postsurgical pain intensity and subsequent healing of a standard 2.0-mm punch biopsy wound.