Neutrophil Responses to Sterile Implant Materials

In vivo implantation of sterile materials and devices results in a foreign body immune response leading to fibrosis of implanted material. Neutrophils, one of the first immune cells to be recruited to implantation sites, have been suggested to contribute to the establishment of the inflammatory microenvironment that initiates the fibrotic response. However, the precise numbers and roles of neutrophils in response to implanted devices remains unclear. Using a mouse model of peritoneal microcapsule implantation, we show 30–500 fold increased neutrophil presence in the peritoneal exudates in response to implants. We demonstrate that these neutrophils secrete increased amounts of a variety of inflammatory cytokines and chemokines. Further, we observe that they participate in the foreign body response through the formation of neutrophil extracellular traps (NETs) on implant surfaces. Our results provide new insight into neutrophil function during a foreign body response to peritoneal implants which has implications for the development of biologically compatible medical devices

In-Person Clinic-Based versus Smartphone Application-Based Plans for Weight Loss among the Overweight and Obese

Background: The prevalence of obesity in the United States (US) among adult men and women continues to rise. Obesity is a major health problem among the US population commonly increasing the risk of significant comorbidities such as type 2 diabetes mellitus, dyslipidemia, and cardiovascular diseases. While in-person interventions that address the dietary, exercise, and behavioral aspects of obesity are common, a new wave of weight loss strategies has emerged with a greater emphasis on technology and internet-based approaches._x000D_ Methods: This study compared the efficacy of a traditional in-person weight loss approach utilized by the Johns Hopkins Weight Management Center to a weight loss treatment via the smartphone application (app), LoseIt!. It was hypothesized that the comparison between the Johns Hopkins Weight Management Center protocol and the LoseIt! App program over a 12-week period would show no difference in the percent of actual weight loss compared to theoretical weight loss i.e., compliance. Using a case-control analysis, 92 Johns Hopkins patients were matched to 3,380 LoseIt! App participants based on gender, age, starting weight, starting BMI, caloric restriction level, and estimated total daily energy expenditure with light activity._x000D_ Results: Clinic patients achieved 94.1% of their theoretical weight loss compared to LoseIt! users who achieved 62.8% after matching. In addition, clinic patients achieved 10.5% total weight loss compared to LoseIt! users who lost 6.1% after matching. Overall, clinic patients showed a significantly greater percent of realized theoretical weight loss or compliance (mean = 28.6, SD = 9.6, p \u3e 0.003) compared to LoseIt! users. Moreover, clinic patients showed a significantly greater percent of total weight loss (mean = 3.2, SD = 0.9, p \u3e 0.001) compared to LoseIt! users._x000D_ Discussion: While weight loss programs are ubiquitous, historically, long-term compliance to these programs is often limited. We found that both clinic-based and technology-based weight loss programs provided a degree of weight loss success when participants are matched for demographic and biologic characteristics. These findings suggest that application-based weight loss programs may have a place in weight control. However, as shown here, they may not be as efficacious as a clinic-based intervention. Nonetheless, this technology may be particularly helpful as a cost-effective means for influencing patient dietary and exercise behaviors. Future studies should examine whether smartphone applications like LoseIt! would produce an additive benefit when used in combination with more traditional approaches to weight control

Failure of High-Dose Daptomycin for Bacteremia Caused by Daptomycin-Susceptible Enterococcus faecium Harboring LiaSR Substitutions

High-dose daptomycin (DAP) therapy failed in a neutropenic patient with bloodstream infection caused by a DAP-susceptible Enterococcus faecium (minimum inhibitory concentration, 3 µg/mL) harboring genetic changes associated with DAP resistance, with persistent bacteremia and selection of additional resistances. Daptomycin monotherapy should be used cautiously against DAP-susceptible E. faecium strains with minimum inhibitory concentrations >2 µg/mL

IL6/STAT3 Signaling Hijacks Estrogen Receptor α Enhancers to Drive Breast Cancer Metastasis.

The cytokine interleukin-6 (IL6) and its downstream effector STAT3 constitute a key oncogenic pathway, which has been thought to be functionally connected to estrogen receptor α (ER) in breast cancer. We demonstrate that IL6/STAT3 signaling drives metastasis in ER+ breast cancer independent of ER. STAT3 hijacks a subset of ER enhancers to drive a distinct transcriptional program. Although these enhancers are shared by both STAT3 and ER, IL6/STAT3 activity is refractory to standard ER-targeted therapies. Instead, inhibition of STAT3 activity using the JAK inhibitor ruxolitinib decreases breast cancer invasion in vivo. Therefore, IL6/STAT3 and ER oncogenic pathways are functionally decoupled, highlighting the potential of IL6/STAT3-targeted therapies in ER+ breast cancer

IL6/STAT3 Signaling Hijacks Estrogen Receptor α Enhancers to Drive Breast Cancer Metastasis.

The cytokine interleukin-6 (IL6) and its downstream effector STAT3 constitute a key oncogenic pathway, which has been thought to be functionally connected to estrogen receptor α (ER) in breast cancer. We demonstrate that IL6/STAT3 signaling drives metastasis in ER+ breast cancer independent of ER. STAT3 hijacks a subset of ER enhancers to drive a distinct transcriptional program. Although these enhancers are shared by both STAT3 and ER, IL6/STAT3 activity is refractory to standard ER-targeted therapies. Instead, inhibition of STAT3 activity using the JAK inhibitor ruxolitinib decreases breast cancer invasion in vivo. Therefore, IL6/STAT3 and ER oncogenic pathways are functionally decoupled, highlighting the potential of IL6/STAT3-targeted therapies in ER+ breast cancer

Neutrophil extracellular traps.

<p>Representative z-stacked immunofluorescence images showing neutrophil elastase and DNA/histone-H1 on the surface of microcapsules. Alginate microcapsules were retrieved 1–2 weeks following implantation, while Polystyrene and PMMA microcapsules were retrieved 3 days following implantation. Images are representative of at least 2 independent experiments with total n ≥ 5 mice, and imaging of multiple retrieved microcapsules from each mouse. Scale bar = 100 μm.</p

Neutrophil Function.

<p>(A)–Confirmation of neutrophil phagocytic capacity. Fluorescent nanoparticles (~190 nm polystyrene nanoparticles) were injected intraperitoneally, 1 week following alginate microcapsule implantation. <i>Left</i>–Representative flow cytometry histograms generated following gating on Ly6G⁺ cells showing nanoparticles (NP) associated with neutrophils. Grey histograms are fluorescence intensities in control mice that have not been injected with nanoparticles. <i>Right</i>–Quantification of the NP uptake histograms, showing a large increase in NP MFI 3 hours post NP injection that drops over time. Data are representative of at least 1 independent experiment with total n ≥ 4. (B)–Multiplex luminex assay to measure chemokines and cytokines secreted by neutrophils. Neutrophils were isolated using a magnetic bead based negative selection technique, followed by <i>ex vivo</i> overnight culture. Higher amounts of key inflammatory cytokines and chemokines are secreted by peritoneal cavity but not bone marrow neutrophils. B.D.L. = below detectable levels. ** and *** indicate p<0.01 and p<0.001, respectively, using a two-tailed Student's t test with Welch's correction (for samples where the levels of cytokine/chemokine are above detectable levels). # indicates p<0.01 using a two-tailed Fisher's exact test, for samples where the levels of cytokine/chemokine were below detectable levels. Data presented are based on n = 6.</p

Flow cytometry schematics.

<p>Representative flow cytometry contour plots describing the gating scheme used to identify different immune cell subsets (isolated 2 weeks followed alginate microcapsule implantation) in the peritoneal cavity. All single cells retrieved from the peritoneal cavity were run through flow cytometry.</p

Increased neutrophil presence is due to biomaterial implants.

<p>(A)–Comparison of neutrophil counts in mice implanted with alginate in its solution or cross-linked hydrogel microcapsule form (measured 2 weeks following implantation). Mock and alginate microcapsule datasets are the same as presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137550#pone.0137550.g002" target="_blank">Fig 2</a>. (B)–Comparison of neutrophil counts in mice implanted with PLGA that will or will not degrade in 2 weeks (measured 2 weeks following implantation). Datasets on PLGA microcapsules that do not degrade are the same as presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137550#pone.0137550.g002" target="_blank">Fig 2</a>. Data are based on at least 2 independent experiments with n ≥ 5 for A and B. *** indicates p<0.001, using one-way ANOVA followed by Bonferroni post-test. (C)–Comparison of neutrophil counts in mice implanted with glass microcapsules that did or did not undergo pyrolysis treatment. Data are based on at least 1 independent experiment with n ≥ 4. 'ns' indicates not significant. Datasets on glass microcapsules that were not pyrolysis treated are the same as presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137550#pone.0137550.g002" target="_blank">Fig 2</a>. (D)–Dependence of number of neutrophils observed in the peritoneal exduate on the number of microcapsules implanted, and less to absence of dependence on surface area of microcapsules. Black dots represent ~500μm, green dot represents ~300μm, red dot represents ~800μm and blue dot represents ~2000μm alginate microcapsules. Data are based on at least 1 independent experiment with n ≥ 5 mice for each microcapsule count. (E)–Curve fitting for data presented in 'D'. A non-linear 3-parameter dose response curve (mean of Log[neutrophil counts] vs Log[microcapsule count] or Log[microcapsule surface area]) was fitted assuming that microcapsules act as a stimulant for neutrophils. R² value was 0.96 for the fit using the microcapsule counts, suggesting a direct correlation between neutrophil counts and microcapsule counts.</p