The receptor TREML4 amplifies TLR7-mediated signaling during antiviral responses and autoimmunity.

The molecules and pathways that fine-tune innate inflammatory responses mediated by Toll-like receptor 7 (TLR7) remain to be fully elucidated. Using an unbiased genome-scale screen with short hairpin RNA (shRNA), we identified the receptor TREML4 as an essential positive regulator of TLR7 signaling. Macrophages from Treml4(-/-) mice were hyporesponsive to TLR7 agonists and failed to produce type I interferons due to impaired phosphorylation of the transcription factor STAT1 by the mitogen-activated protein kinase p38 and decreased recruitment of the adaptor MyD88 to TLR7. TREML4 deficiency reduced the production of inflammatory cytokines and autoantibodies in MRL/lpr mice, which are prone to systemic lupus erythematosus (SLE), and inhibited the antiviral immune response to influenza virus. Our data identify TREML4 as a positive regulator of TLR7 signaling and provide insight into the molecular mechanisms that control antiviral immunity and the development of autoimmunity.

A Multicenter Study Evaluating the Effect of Ulipristal Acetate during Myomectomy.

STUDY OBJECTIVE: To compare surgical experience at myomectomy between patients with myomas pretreated with ulipristal acetate versus no pretreatment. DESIGN: A prospective, observational, multicenter study of myomectomy procedures by any route (hysteroscopic, laparoscopic, or laparotomy) (Canadian Task Force classification II-2). SETTING: Five university-affiliated hospitals including tertiary care and community sites. PATIENTS: Any patient who underwent hysteroscopic, laparotomic, or laparoscopic myomectomy regardless of medical pretreatment. INTERVENTIONS: Surgeons completed a Web-based questionnaire after each myomectomy procedure. Surgeons evaluated visualization, the myoma-myometrium relationship, extrusion, fluid deficit, blood loss, and overall ease of hysteroscopic myomectomies. For laparotomic/laparoscopic myomectomies, plane delineation, myoma separation, blood loss, and overall ease were assessed. The total surgical experience score was calculated by summing the values for each subscale. MEASUREMENTS AND MAIN RESULTS: A total of 309 myomectomies were evaluated by 52 surgeons (response rate = 83%) at 5 institutions. Of 140 hysteroscopic myomectomies, 84 (60%) were performed without pretreatment, 29 (21%) after ulipristal acetate pretreatment, and 27 (19%) after pretreatment with gonadotropin-releasing hormone agonist/other. Of 169 laparotomic/laparoscopic myomectomies, 104 (62%) were performed without pretreatment, 46 (27%) after ulipristal acetate, and 19 (11%) after gonadotropin-releasing hormone agonist/other. The mean surgical experience score (±standard deviation) was comparable between the no pretreatment and ulipristal acetate groups for hysteroscopic myomectomies (13.8 ± 2.2 vs 13.3 ± 2.2, p = .35) and laparotomic/laparoscopic myomectomies (12.9 ± 4.1 vs 12.1 ± 4.2, p = .30). Compared with no pretreatment, more laparotomic/laparoscopic myomectomies after ulipristal acetate pretreatment were associated with difficult delineation of surgical planes (22 [47.8%] vs 23 [22.1%], p = .002) and difficult myoma separation (20 [43.5%] vs 21 [20.2%], p = .003). More myomas were described as soft with ulipristal acetate pretreatment (14 [30.4%] vs 17 [16.4%], p = .049). The rates of profuse/abundant endometrium during hysteroscopy were similar between the no pretreatment (21 [25.0%]) and ulipristal acetate (7 [24.1%], p = .93) groups. CONCLUSION: Despite differences in surgical nuances, the overall myomectomy experience was not negatively affected by ulipristal acetate pretreatment.

A Role for Low Density Lipoprotein Receptor-Related Protein 1 in the Cellular Uptake of Tissue Plasminogen Activator in the Lungs.

PURPOSE: To gain knowledge of lung clearance mechanisms of inhaled tissue plasminogen activator (tPA). METHODS: Using an in vivo mouse model and ex vivo murine whole organ cell suspensions, we examined the capability of the lungs to utilize LRP1 receptor-mediated endocytosis (RME) for the uptake of exogenous tPA with and without an LRP1 inhibitor, receptor associated protein (RAP), and quantitatively compared it to the liver. We also used a novel imaging technique to assess the amount LRP1 in sections of mouse liver and lung. RESULTS: Following intratracheal administration, tPA concentrations in the bronchoalveolar lavage fluid (BALF) declined over time following two-compartment pharmacokinetics suggestive of a RME clearance mechanism. Ex vivo studies showed that lung and liver cells are similarly capable of tPA uptake via LRP1 RME which was reduced by ~50% by RAP. The comparable lung and liver uptake of tPA is likely due to equivalent amounts of LRP1 of which there was an abundance in the alveolar epithelium. CONCLUSIONS: Our findings indicate that LRP1 RME is a candidate clearance mechanism for inhaled tPA which has implications for the development of safe and effective dosing regimens of inhaled tPA for the treatment of plastic bronchitis and other fibrin-inflammatory airway diseases in which inhaled tPA may have utility.

Evolutionarily conserved recognition and innate immunity to fungal pathogens by the scavenger receptors SCARF1 and CD36.

Receptors involved in innate immunity to fungal pathogens have not been fully elucidated. We show that the Caenorhabditis elegans receptors CED-1 and C03F11.3, and their mammalian orthologues, the scavenger receptors SCARF1 and CD36, mediate host defense against two prototypic fungal pathogens, Cryptococcus neoformans and Candida albicans. CED-1 and C03F11.1 mediated antimicrobial peptide production and were necessary for nematode survival after C. neoformans infection. SCARF1 and CD36 mediated cytokine production and were required for macrophage binding to C. neoformans, and control of the infection in mice. Binding of these pathogens to SCARF1 and CD36 was beta-glucan dependent. Thus, CED-1/SCARF1 and C03F11.3/CD36 are beta-glucan binding receptors and define an evolutionarily conserved pathway for the innate sensing of fungal pathogens.

Gastroschisis: what is the average gestational age of spontaneous delivery?

BACKGROUND/PURPOSE: To consolidate what is known about pregnancies complicated by fetal gastroschisis through analysis of one of the largest series yet reported and to define the average gestational age of spontaneous delivery. METHODS: From 1980 to 2001, 159 pregnancies complicated by fetal gastroschisis were identified at a tertiary care center. Gestational age at delivery, birth weight, preterm delivery rate, and maternal age were compared to the 2001 general population statistics. Patients with pregnancies complicated by gastroschisis who went into spontaneous labor (n = 86) were subdivided into 2 groups based on gestational age (< 37 weeks and > or = 37 weeks). Operative delivery rates for nonreassuring fetal status and Apgar scores were assessed. RESULTS: Gastroschisis occurred more often in younger mothers (< 21 years) (42% vs 7.3%), was more frequently associated with preterm labor and delivery (28% vs 6%), and was associated with more low-birth-weight babies (36% vs 10%). The mean gestational age at spontaneous labor was 36.6 weeks. In those patients who labored spontaneously, there were no significant differences in the operative delivery rates for fetal distress; however, there was a trend to lower Apgar scores in babies born at 37 weeks or more. CONCLUSION: Our data provide a framework for further studies to determine the optimal timing and mode of delivery for fetuses with gastroschisis.