Faculty Bibliography

The purpose of this study was to evaluate whether patients with hip fractures receiving antiplatelet and direct oral anticoagulants treated within 48 hours of admission had worse surgical and clinical outcomes than those whose surgery was delayed more than 48 hours. Consecutive patients 55 years and older with an operatively treated hip fracture were analyzed. Patients receiving the following anticoagulants were included: antiplatelet drugs, factor Xa inhibitors, and direct thrombin inhibitors. Outcomes included surgical blood loss, procedure time, transfusion requirement, length of stay, complication rate, and need for intensive care unit or step-down unit level care. Patients who underwent surgery within 48 hours of presentation were compared with patients whose surgery was delayed more than 48 hours. Of 551 consecutive operative hip fracture patients, 78 (14.2%) were receiving the anticoagulant medications included in this study. Of these 78 patients, 58 had surgery within 48 hours and 20 had surgery after 48 hours. When comparing the early and delayed fixation cohorts, there was no difference in transfusion requirement, length of surgery, or blood loss. Type of anticoagulant made no difference in transfusion requirement, blood loss, or length of surgery. There was also no difference in the mean number of complications or in the need for intensive care unit or step-down unit level care. In this study, patients receiving antiplatelet therapy, factor Xa inhibitors, or direct thrombin inhibitors who underwent surgical fixation of their hip fracture within 48 hours of admission were at no higher risk for transfusion, increased surgical blood loss, longer operative time, or inpatient mortality. [Orthopedics. 201x; xx(x):xx-xx.].

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks.

Hox genes are evolutionarily conserved transcription factors that during embryonic development function as master regulators of positional identity. In postnatal life, the function of Hox proteins is less clear: Hox genes are expressed during tissue repair, but in this context their function(s) are largely unknown. Here we show that Hox genes are expressed in periosteal stem/progenitor cells in a distribution similar to that during embryonic development. Using unbiased sequencing, we established that periosteal stem/progenitor cells from distinct anatomic sites within the skeleton significantly differ in their transcriptome, and that Hox expression status best defines these differences. Lastly, we provide evidence that Hox gene expression is one potential mechanism that maintains periosteal stem/progenitor cells in a more primitive, tripotent state, while suppression of Hox genes leads to fate changes with loss of tripotency. Together, our data describe an adult role of Hox genes other than positional identity, and the modulatory role of Hox genes in fate decisions may offer potential druggable targets for the treatment of fractures, non-unions and bone defects.

BACKGROUND:in healthy Caucasian non-Hispanic individuals. METHODS:is achieved, additional HF-LED-RL phototherapy subjects and mock therapy subjects will be enrolled at that fluence (group 3) for a total number of up to 60 subjects. Each subject will receive a total of nine irradiation sessions, three times per week for three consecutive weeks. DISCUSSION/CONCLUSIONS:in Caucasian non-Hispanic subjects. The importance of this clinical trial is that it may establish new treatment paradigms and a safety profile for LED-RL based on race and ethnicity. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov Identifier: NCT03433222 . Registered on February 1, 2018 - Retrospectively registered. Protocol date and version: January 12, 2018; version 1.

Ionizing radiation (IR) and chemotherapy are standard-of-care treatments for glioblastoma (GBM) patients and both result in DNA damage, however, the clinical efficacy is limited due to therapeutic resistance. We identified a mechanism of such resistance mediated by phosphorylation of PTEN on tyrosine 240 (pY240-PTEN) by FGFR2. pY240-PTEN is rapidly elevated and bound to chromatin through interaction with Ki-67 in response to IR treatment and facilitates the recruitment of RAD51 to promote DNA repair. Blocking Y240 phosphorylation confers radiation sensitivity to tumors and extends survival in GBM preclinical models. Y240F-Pten knockin mice showed radiation sensitivity. These results suggest that FGFR-mediated pY240-PTEN is a key mechanism of radiation resistance and is an actionable target for improving radiotherapy efficacy.

RATIONALE/BACKGROUND:Inhibition of miR-33 reduces atherosclerotic plaque burden, but miR-33 deficient mice are predisposed to the development of obesity and metabolic dysfunction. The pro-atherogenic effects of miR-33 are thought to be in large part due to its repression of macrophage cholesterol efflux, through targeting of ATP Binding Cassette Subfamily A Member 1 ( Abca1). However, targeting of other factors may also be required for the beneficial effects of miR-33 and currently available approaches have not allowed researchers to determine the specific impact of individual miRNA target interactions in vivo. OBJECTIVE:In this work, we sought to determine how specific disruption of Abca1 targeting by miR-33 impacts macrophage cholesterol efflux and atherosclerotic plaque formation in vivo. METHODS AND RESULTS/RESULTS:mice had reduced atherosclerotic plaque formation, similar to mice transplanted with bone marrow from miR-33 knockout mice. CONCLUSIONS:Although the more pronounced phenotype of miR-33 deficient animals suggests that other targets may also play an important role, our data clearly demonstrate that repression of ABCA1 is primarily responsible for the pro-atherogenic effects of miR-33. This work shows for the first time that disruption of a single miRNA/target interaction can be sufficient to mimic the effects of miRNA deficiency on complex physiologic phenotypes in vivo and provides an approach by which to assess the impact of individual miRNA targets.

The pathogenesis of Staphylococcus aureus is thought to depend on the production of pore-forming leukocidins that kill leukocytes and lyse erythrocytes. Two leukocidins, Leukocidin ED (LukED) and γ-Hemolysin AB (HlgAB), are necessary and sufficient to kill mice upon infection and toxin challenge. We demonstrate that LukED and HlgAB cause vascular congestion and derangements in vascular fluid distribution that rapidly cause death in mice. The Duffy antigen receptor for chemokines (DARC) on endothelial cells, rather than leukocytes or erythrocytes, is the critical target for lethality. Consistent with this, LukED and HlgAB injure primary human endothelial cells in a DARC-dependent manner, and mice with DARC-deficient endothelial cells are resistant to toxin-mediated lethality. During bloodstream infection in mice, DARC targeting by S. aureus causes increased tissue damage, organ dysfunction, and host death. The potential for S. aureus leukocidins to manipulate vascular integrity highlights the importance of these virulence factors.

Background: The mechanisms for increased cardiovascular risk in patients with Psoriasis (PsO) are unknown. Activated platelets adhere to damaged endothelium and secrete pro-inflammatory cytokines thus promoting atherosclerosis. The contribution of platelets to promote endothelial activation in PsO has not been established. Method(s): Patients with active PsO (n = 6, mean age 46 years, 50% male) were compared to age- and sex- matched controls. Result(s): Platelets were present in PsO lesional skin compared to non-lesional skin, and controls (Figure 1A). To investigate the clinical significance, isolated platelets from PsO and matched-controls demonstrated increased platelet adhesion to human aortic endothelial cells (HAECs) in both basal and activated (thrombin stimulated) states (Figure 1B). Platelets isolated from PsO subjects enhanced HAEC expression of pro-inflammatory transcripts IL-1B, IL-8 and COX-2 (Figure 1C) compared to controls. Next generation RNA sequencing of isolated platelets from PsO and controls revealed upregulation of transcripts indicative of platelet - endothelial interactions such as the pro-atherogenic mediators s100A8/A9 (p < 0.05). Conclusion(s): We describe for the first time platelet-endothelial interactions as a potential mechanism of early cardiovascular risk in patients with PsO. These findings have important clinical implications suggesting that targeting platelet specific pathways in PsO may reduce cardiovascular risk. [Figure presented]2019 American College of Cardiology Foundation. All rights reserved

Genomic instability is widespread during early embryo development. Aneuploidy, mosaicism, and copy number variants (CNVs) commonly appear in human preimplantation embryos. Both age-dependent meiotic aneuploidy and age-independent mitotic aneuploidy and CNVs occur In human embryos. Telomere attrition, which contributes to genomic instability in somatic cells, also may promote genomic instability in preimplantation embryos. Telomere dynamics during gametogenesis are strikingly dimorphic between females and males. Sperm telomeres lengthen with advancing paternal age, while oocyte telomeres are among the shortest in the body. Spermatogonia express telomerase activity throughout the life of the male, while oocytes and cleavage stage embryos express low or un-measureable levels of telomerase activity. Telomere attrition in oocytes contributes to meiotic dysfunction, including spindle dysmorphologies, reduced synapsis and chiasmata, as well as delayed, arrested and fragmented embryos. Cleavage stage embryos, with such inefficient telomere reconstitution, likely undergo NHEJ, which produces anaphase lag, chromosome bridges, micronuclei, and genomic instability, including mosaicism and CNVs. Cleavage stage embryos reconstitute the short telomeres inherited from their mothers by Alternative Lengthening of Telomeres (ALT), a DNA recombination based method involving RAD 50, MRE 11, Werner and Bloom proteins, as well as telomere sister chromatid exchange. ALT robustly reconstitutes telomeres, but also predisposes to genomic instability.

Targeting stemness promises new therapeutic strategies against highly invasive tumors. While a number of approaches are being tested, inhibiting the core transcription regulatory network of cancer stem cells is an attractive yet challenging possibility. Here we have aimed to provide the proof of principle for a strategy, previously used in developmental studies, to directly repress the targets of a salient stemness and pluripotency factor: NANOG. In doing so we expected to inhibit the expression of so far unknown mediators of pro-tumorigenic NANOG function. We chose NANOG since previous work showed the essential requirement for NANOG activity for human glioblastoma (GBM) growth in orthotopic xenografts, and it is apparently absent from many adult human tissues thus likely minimizing unwanted effects on normal cells. NANOG repressor chimeras, which we name NANEPs, bear the DNA-binding specificity of NANOG through its homeodomain (HD), and this is linked to transposable human repressor domains. We show that in vitro and in vivo, NANEP5, our most active NANEP with a HES1 repressor domain, mimics knock-down (kd) of NANOG function in GBM cells. Competition orthotopic xenografts also reveal the effectiveness of NANEP5 in a brain tumor context, as well as the specificity of NANEP activity through the abrogation of its function via the introduction of specific mutations in the HD. The transcriptomes of cells expressing NANEP5 reveal multiple potential mediators of pro-tumorigenic NANEP/NANOG action including intercellular signaling components. The present results encourage further studies on the regulation of context-dependent NANEP abundance and function, and the development of NANEP-based anti-cancer therapies.