Hybrid Simulations of Positively and Negatively Charged Pickup Ions and Cyclotron Wave Generation at Europa

In the vicinity of Europa, Galileo observed bursty Alfvén-cyclotron wave power at the gyrofrequencies of a number of species including K⁺, O 2+, Na⁺, and Cl⁺, indicating the localized pickup of these species. Additional evidence for the presence of chlorine was the occurrence of both left-hand (LH) and right-hand (RH) polarized transverse wave power near the Cl⁺ gyrofrequency, thought to be due to the pickup of both Cl⁺ and the easily formed chlorine anion, Cl^-. To test this hypothesis, we use one-dimensional hybrid (kinetic ion, massless fluid electron) simulations for both positive and negative pickup ions and self-consistently reproduce the growth of both LH and RH Alfvén-cyclotron waves in agreement with linear theory. We show how the simultaneous generation of LH and RH waves can result in nongyrotropic ion distributions and increased wave amplitudes, and how even trace quantities of negative pickup ions are able to generate an observable RH signal. Through comparing simulated and observed wave amplitudes, we are able to place the first constraints on the densities of Chlorine pickup ions in localized regions at Europa.

Identification of Osr2 Transcriptional Target Genes in Palate Development

Previous studies have identified the odd-skipped related 2 (Osr2) transcription factor as a key intrinsic regulator of palatal shelf growth and morphogenesis. However, little is known about the molecular program acting downstream of Osr2 in the regulation of palatogenesis. In this study, we isolated palatal mesenchyme cells from embryonic day 12.5 (E12.5) and E13.5 Osr2^RFP/+ and Osr2^RFP/- mutant mouse embryos and performed whole transcriptome RNA sequencing analyses. Differential expression analysis of the RNA sequencing datasets revealed that expression of 70 genes was upregulated and expression of 61 genes was downregulated by >1.5-fold at both E12.5 and E13.5 in the Osr2^RFP/- palatal mesenchyme cells, in comparison with Osr2^RFP/+ littermates. Gene ontology analysis revealed enrichment of signaling molecules and transcription factors crucial for skeletal development and osteoblast differentiation among those significantly upregulated in the Osr2 mutant palatal mesenchyme. Using quantitative real-time polymerase chain reaction (RT-PCR)and in situ hybridization assays, we validated that the Osr2^-/- embryos exhibit significantly increased and expanded expression of many osteogenic pathway genes, including Bmp3, Bmp5, Bmp7, Mef2c, Sox6, and Sp7 in the developing palatal mesenchyme. Furthermore, we demonstrate that expression of Sema3a, Sema3d, and Sema3e, is ectopically activated in the developing palatal mesenchyme in Osr2^-/- embryos. Through chromatin immunoprecipitation, followed by RT-PCR analysis, we demonstrate that endogenous Osr2 protein binds to the promoter regions of the Sema3a and Sema3d genes in the embryonic palatal mesenchyme. Moreover, Osr2 expression repressed the transcription from the Sema3a and Sema3d promoters in cotransfected cells. Since the Sema3 subfamily of signaling molecules plays diverse roles in the regulation of cell proliferation, migration, and differentiation, these data reveal a novel role for Osr2 in regulation of palatal morphogenesis through preventing aberrant activation of Sema3 signaling. Together, these data indicate that Osr2 controls multiple molecular pathways, including BMP and Sema3 signaling, in palate development.

The Effects of Lentivirus-mediated shRNA Interference Targeting Mcl-1 on Growth of NK/T-cell Lymphoma

Myeloid leukemia-1 (Mcl-1) gene has been reported as an important factor in various types of cancer, but little research was processed on natural killer (NK)/T-cell lymphoma, a kind of a highly aggressive disease with a poor prognosis. Here we investigated the expression of Mcl-1 in seven lymphoma cell lines and its potential role as a molecular drug target for NK/T-cell lymphoma therapy by using lentivirus-mediated shRNA interference targeting Mcl-1 (lenti-shMcl-1). In our study, the expression of Mcl-1 in different lymphoma cell lines were evaluated firstly, after that lenti-shMcl-1 was constructed and transduced into NK/T-cell lymphoma cell line SNK-6 which had a high level expression of Mcl-1. Methylthiazolete-Trazolium (MTT) assay and flow cytometry (FCA) were employed to detect the status of proliferation and apoptosis after infection. Lastly we investigated the effects of chemotherapy agent vincristine (VCR) combination with lenti-shMcl-1 by MTT and FCA assay. The results showed that Mcl-1 gene expressed in all seven lymphoma cell lines at different levels. Recombinant lentiviruses could infect SNK-6 cells effectively. Mcl-1 expression level was remarkably down-regulated after infection with lenti-shMcl-1. The growth of SNK-6 cells was inhibited significantly through apoptosis pathway. Otherwise, lenti-shMcl-1 also revealed a significant chemosensitizing effect in combination with vincristine. In a word, we demonstrated that lenti-shMcl-1 had a significant anti-NK/T cell lymphoma effect and targeting Mcl-1 therapy could be a promising novel approach in treatment of lymphoma.

Tissue-specific effects of estrogen on glycerol channel aquaporin 7 expression in an ovariectomized mouse model of menopause

OBJECTIVE

Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7.

METHODS

We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol.

RESULTS

Removal of the ovaries resulted in a significant decrease in AQP7 expression and an increase in GK expression in visceral adipocyte tissue; expression of AQP7 and GK in subcutaneous adipose tissue remained unaltered. Supplementation with estrogen significantly restored the visceral, but not subcutaneous, fat depot mass and adipocyte size to those of sham-operated mice. A marked increase in the expression of AQP7 and a reduction of GK were observed selectively in the visceral fat depots in estrogen-treated mice.

CONCLUSIONS

Our results suggest that estrogen has tissue-specific effects on AQP7 expression, and modulation of AQP7 by estrogen alters the balance of adipocyte metabolism between adipose tissue depots.

In Depth Spatially Inhomogeneous Phase Transition in Epitaxial MnAs Film on GaAs(001)

Most studies on MnAs material in its bulk form have been focused on its temperature-dependent structural phase transition accompanied by a magnetic one. Magnetostructural phase transition parameters in thin MnAs films grown on substrates present however some differences from the bulk behavior, and local studies become mandatory for a deeper understanding of the mechanisms involved within the transition. Up to now, only surface techniques have been carried out, while the transition is a three-dimensional phenomenon. We therefore developed an original nanometer scale methodology using electron holography to investigate the phase transition in an epitaxial MnAs thin film on GaAs(001) from the cross-section view. Using quantitative magnetic maps recorded at the nanometer scale as a function of the temperature, our work provides a direct in situ observation of the inhomogeneous spatial distribution of the transition in the layer depth and brings new insights on the fundamental transition mechanisms.

Abstract PD2-04: FOXA1 induces a pro-metastatic secretome through ER-dependent and independent transcriptional reprogramming in endocrine-resistant breast cancer

Background: Metastasis in ER-positive (+) breast cancer (BC) occurring years to decades after initial diagnosis presents a daunting challenge for clinical care and preclinical research due to limited known key players and experimental models. FOXA1 is a pioneer factor for ER-chromatin binding and function, and is highly expressed in ER+ BC metastases, yet the underlying mechanism is unclear. Tumor-secreted proteins play a crucial role in the reciprocal interplay between cancer cells and host microenvironmental factors at both primary and secondary sites. We hypothesized that high FOXA1 provokes an ER-dependent transcriptional program that includes a unique pro-tumorigenic secretome essential for promoting ER+ BC metastasis. Methods: A lentiviral doxycycline (Dox)-inducible FOXA1 overexpression vector and a dual luciferase/GFP (LG) tracking vector were integrated to construct a stable MCF7-LG/FOXA1 cell model. Ovariectomized nude mice bearing MCF7-LG/FOXA1 xenografts in the presence of exogenous estrogen (E2) were randomized to ± Dox, each with continued E2, E2 deprivation (ED), or tamoxifen (Tam). Survival surgery removing the therapy-naïve (E2 arm) and relapsed (ED/Tam arms) tumors was performed when tumors reached ∼1000 mm3. All mice then received ED/Tam 'adjuvant' therapy, with longitudinal luminescence imaging to monitor local/distant recurrences. Mice were or will be euthanized at the ethical end-point. Integrative bioinformatics was performed using RNA-seq and FOXA1/ER ChIP-seq data from our preclinical models to identify secretome targets for functional intervention. Times to tumor regression (TTR) and progression (TTP) were defined by when the tumor reached half or twice the volume at randomization. Results: Median (m) TTR was achieved in ED (31/34 days, -/+Dox, P = 0.184) but not in Tam groups — Tam delayed tumor growth but failed to prevent progression in all mice with mTTP of 94/93 days (-/+Dox, P = 0.517). Despite no difference in mTTP at Tam-/+Dox, a quarter of +Dox tumors (3/12) had volume doubled by day 11. No metastases were observed by imaging in any of the mice before surgery ('neoadjuvant' setting). Local relapse and lymph-node/lung metastases were detected after surgery ('adjuvant' setting). At day 90 in the adjuvant Tam group with previously relapsed tumors, +Dox mice succumbed to metastasis more often than -Dox mice (7/8 vs. 3/10, P = 0.023). Compared to the adjuvant Tam+Dox mice with previous therapy-naïve tumors, the Tam+Dox with previously relapsed tumors showed higher distant metastasis rate (7/8 vs. 5/14, P = 0.026). Analysis of the ED setting is pending due to late recurrence. Data integration and functional study revealed a set of cytokines, growth factors, and extracellular matrix components (including IL-8, CTGF, and LOX), regulated by FOXA1 often in conjunction with ER, that are highly involved in FOXA1-induced metastasis. Global secretome profiling by mass spectrometry and target validation are ongoing. Conclusions: FOXA1 overexpression increases metastatic potential in ER+ BC. We established a pertinent metastatic xenograft mouse model to characterize a pro-metastatic secretome with diagnostic and therapeutic potential for treating metastatic ER+ BC.

Citation Format: Fu X, Pereira R, Zhao D, Jung SY, Jeselsohn R, Creighton CJ, Shea M, Nardone A, Angelis CD, Tsimelzon A, Wang T, Gutierrez C, Huang S, Edwards DP, Rimawi MF, Hilsenbeck SG, Brown M, Chen K, Osborne CK, Schiff R. FOXA1 induces a pro-metastatic secretome through ER-dependent and independent transcriptional reprogramming in endocrine-resistant breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD2-04.

Abstract P3-04-07: The new oral SERD AZD9496 is efficacious in antagonizing ER and circumventing resistance to endocrine therapy

Background: The selective estrogen receptor (ER) degrader (SERD) fulvestrant (Ful) is a potent ER antagonist that upon binding to ER induces its degradation. Ful has shown clinical efficacy in metastatic disease upon progression on previous endocrine therapies and superior activitycompared to an aromatase inhibitor as first line therapy when given at a high dose, 500mg. However, major clinical limitations of Ful are its low bioavailability and its route of administration. Here, we assess the efficacy and the mechanism of action of the new oral SERD AZD9496 compared to Ful in our panel of endocrine-sensitive and -resistant (EndoR) in vitro and in vivo models.

Methods: The effects of AZD9496 and Ful were studied in vitro in various ER+ MCF7, ZR75-1, T47D, 600MPE, and MDAMB415 parental lines and in MCF7 and T47D derivatives made resistant (R) to estrogen deprivation (ED), tamoxifen (Tam), or Ful. Cell growth, Western blot, Q-RT-PCR, and ERE-reporter assays were conducted to assess treatment efficacy as well as ER levels and activity. Xenografts of parental MCF7 cells were established in ovariectomized nude mice with exogenous estrogen (E2). Mice were then randomized to continued E2 or ED, with and without AZD9496 or Ful. Mice bearing transplantable MCF7 EDR and TamR xenografts were randomized to continue original treatment or to switch to Ful or AZD9496, and tumor size was followed. Expression of classic and nonclassic/indirect ER-regulated genes was evaluated in RNA extracts of short-term-treated xenografts using the BioMark FLUIDIGM platform.

Results: AZD9496 inhibited cell growth (50-100%) of all ER+ parental cells and greatly, though not fully, degraded ER protein levels. AZD9496 also potently reduced ER-dependent exogenous and endogenous gene/protein expression in presence and absence of E2. In parental MCF7 xenograft-bearing mice, 10 days of AZD9496 resulted in a greater inhibition of tumor growth and in a greater reduction of levels of ER-dependent targets in comparison to Ful in the presence of E2. The effects of the 2 SERDs were similar in the absence of E2. In EndoR models that retain ER, AZD9496 inhibited cell growth in vitro by degrading ER, similar to Ful. Both SERDs also delayed tumor growth of EDR and TamR xenografts and effectively reduced levels of ER and ER-induced proteins, though no tumor regression was observed in the TamR model. Notably, AZD9496 failed to inhibit growth of FulR cells and xenografts. Expression analysis showed that the 2 SERDs potently inhibited classic ER activity, while simultaneously increasing expression of some genes known to be regulated by the nonclassic/indirect ER activity, including genes involved in escape pathways of endocrine resistance.

Conclusions: The oral SERD AZD9496 is a potent antiestrogen that antagonizes and degrades ER. AZD9496, like Ful, inhibits ER-dependent transcription and tumor growth in both naïve and resistant EDR and TamR models, but shows cross-resistance in FulR models. Both AZD9496 and Ful failed to completely reduce ER protein expression and to induce TamR tumor regression, suggesting that additional strategies to reduce ER levels and to enhance the inhibition of ER signaling and/or of co-operating survival mechanisms may be needed to improve treatment outcome.

Citation Format: Nardone A, Weir H, De Angelis C, Cataldo ML, Fu X, Shea MJ, Mitchell T, Trivedi M, Chamness GC, Osborne CK, Schiff R. The new oral SERD AZD9496 is efficacious in antagonizing ER and circumventing resistance to endocrine therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-07.

The synergistic antiviral effects of GSH in combination with acyclovir against BoHV-1 infection in vitro

We have recently reported that bovine herpesvirus 1 (BoHV-1)-induced overproduction of reactive oxygen species (ROS) partially depends on NADPH oxidases (Noxs). In this study, we found that the decreased levels of main intracellular non-enzymatic antioxidant glutathione (GSH) during BoHV-1 infection also contributed to ROS production. Exogenous GSH administration dramatically inhibited BoHV-1 replication, indicating the critical role of decreased GSH for BoHV-1 replication. Interestingly, GSH synergistically enhanced the antiviral effects of acyclovir (ACV) against BoHV-1 infection in vitro. This study not only illuminates the effect of GSH on BoHV-1 infection but also provides evidence that pharmacological modulation of GSH-mediated ROS production in combination with specific antiviral drugs is a viable therapeutic approach to fighting virus infection.

The effect of glycaemic control in type 2 diabetic patients with subclinical hypothyroidism

OBJECTIVE

The purpose of this study was to investigate the effect of glycaemic control on subclinical hypothyroidism (SCH) in Chinese type 2 diabetic patients.

METHODS

The study included 476 diabetic patients with SCH admitted for treatment of type 2 diabetes. The controls were selected euthyroid patients with similar characteristics regarding [age, body mass index (BMI), gender, previous hypertension or duration of diabetes, and smoke]. Total cholesterol (TC), LDL cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), the homeostatic model assessment of insulin resistance ratio (HOMA-IR), fasting plasma glucose, hemoglobin A_1c (HbA_1c), as well as plasma levels of thyrotrophin, and free thyroxine (FT4) were assessed at baseline and after 6 months of glycaemic control treatment.

RESULTS

The LDL-C level and HOMA-IR value were significantly higher in the SCH group. Glycaemic control reduced HOMA-IR, HbA_1c, LDL-C, and TG level in patients with SCH. Furthermore, glycaemic control plays a negative effect on thyrotrophin in the SCH group, while this effect was not observed in euthyroid subjects. HbA_1c plays a positive correlation with HOMA-IR (r = 0.048, p < 0.001), fasting plasma glucose (r = 0.086, p < 0.001), LDL-C (r = 0.062, p < 0.001) and TG (r = 0.021, p = 0.009).

CONCLUSION

Our study shows that glycaemic control may bring some benefits to type 2 diabetic patients with SCH.

Intraosseous Injection of Simvastatin in Poloxamer 407 Hydrogel Improves Pedicle-Screw Fixation in Ovariectomized Minipigs

BACKGROUND

Osteoporosis leads to poor osseointegration and reduces implant stability. Statins have been found to stimulate bone formation, but the bioavailability from oral administration is low. Local application may be more effective at augmenting bone formation and enhancing implant stability. This study was performed to evaluate the efficacy of an intraosseous injection of simvastatin in thermosensitive poloxamer 407 hydrogel to enhance pedicle-screw fixation in calcium-restricted ovariectomized minipigs.

METHODS

Nine mature female Guangxi Bama minipigs underwent bilateral ovariectomy and were fed a calcium-restricted diet for 18 months. Simvastatin (0, 0.5, or 1 mg) in thermosensitive poloxamer 407 hydrogel was injected into the lumbar vertebrae (L4-L6), and titanium alloy pedicle screws were implanted. Bone mineral density (BMD) measurements of the lumbar vertebrae were determined by dual x-ray absorptiometry (DXA) before and 3 months after treatment. The lumbar vertebrae were harvested and analyzed with use of microcomputed tomography, biomechanical pull-out testing, histological analysis, and Western blot analysis for bone morphogenetic protein (BMP)-2 and vascular endothelial growth factor (VEGF) expression.

RESULTS

Evaluation over a 3-month study period demonstrated that the BMD of the vertebrae injected with 0.5 and 1.0 mg of simvastatin had increased by 31.25% and 31.09%, respectively, compared with vehicle-only injection (p ≤ 0.00014 for both) and increased by 32.12% and 28.16%, respectively, compared with the pre-treatment levels (p < 0.0001 for both). A single injection of simvastatin in poloxamer 407 increased trabecular volume fraction, thickness, and number and decreased trabecular separation (p ≤ 0.002). The bone formation and mineral apposition rates significantly increased (p ≤ 0.023). The percentage of osseointegration in the simvastatin 0.5 and 1-mg groups was 46.54% and 42.63% greater, respectively, than that in the vehicle-only group (p ≤ 0.006), and the maximum pull-out strength was 45.75% and 51.53% greater, respectively, than in the vehicle-only group (p ≤ 0.0005). BMP-2 and VEGF expressions were higher than for the vehicle-only injection.

CONCLUSIONS

A single intraosseous injection of simvastatin in thermosensitive poloxamer 407 hydrogel stimulated bone formation, increased BMD, improved bone microstructure, promoted osseointegration, and significantly enhanced the stability of pedicle screws in calcium-restricted ovariectomized minipigs.

CLINICAL RELEVANCE

These results provide rationale for evaluating intraosseous injection of simvastatin in poloxamer 407 to enhance implant fixation in patients with osteoporosis.