Titanium dioxide nanoparticles induce in vitro autophagy

Aim:

Concerns about the possible toxicity to environment and human health of titanium dioxide nanoparticles (TiO2 NPs) are increasing. The aim of this study was to investigate the relationship between toxicology and autophage in vitro.

Methods:

RAW 264.7 cells were exposed to five concentrations (50, 100, 200, 300, and 400 μg/mL) and two particle size of TiO2 NPs (30 and 100 nm) for 24 h.

Results:

The results showed that TiO2 NPs decreased cell viability, phagocytic rate, and phagocytic index in a concentration-dependent manner, thereby inducing autophagy. TiO2 NPs-induced autophagy was indicated by monodansyl cadaverine staining and transmission electron microscopy. TiO2 NPs-induced messenger RNA expression of autophagy-related proteins LC3 and Beclin-1 was also significantly increased compared with those of the unexposed control cells. LC3 and Beclin-1 protein expression levels were markedly increased with the increase of TiO2 NPs concentrations.

Conclusion:

These results suggest the possibility that TiO2 NPs-induced toxicology probably plays a key role in autophagy in RAW 264.7 cells, and further exhaustive research on the harmful effects of these NPs in relevant organisms is needed for their safe application.

Colorectal-Vaginal Fistulas: Imaging and Novel Interventional Treatment Modalities

Colovaginal and/or rectovaginal fistulas cause significant and distressing symptoms, including vaginitis, passage of flatus/feces through the vagina, and painful skin excoriation. These fistulas can be a challenging condition to treat. Although most fistulas can be treated with surgical repair, for those patients who are not operative candidates, limited options remain. As minimally-invasive interventional techniques have evolved, the possibility of fistula occlusion has enriched the therapeutic armamentarium for the treatment of these complex patients. In order to offer optimal treatment options to these patients, it is important to understand the imaging and anatomical features which may appropriately guide the surgeon and/or interventional radiologist during pre-procedural planning.

Estrous cycle-dependent modulation of in vivo microvascular dysfunction after nanomaterial inhalation

Preconceptive health encompasses male and female reproductive capability. In females, this takes into account each of the stages of the estrous cycle. Microvascular reactivity varies throughout the estrous cycle in response to hormonal changes and in preparation for pregnancy. Microvascular alterations in response to engineered nanomaterial (ENM) exposure have been described within 24-h of inhalation; however, the impact upon the uterine vasculature at differing estrous stages and at late-stage pregnancy is unclear. Female Sprague Dawley (SD) rats (virgin and late stage pregnancy [GD 19]) were exposed to nano-TiO aerosols (173.2 ± 6.4 nm, 10.2 ± 0.46 mg/m³, 5 h) 24-h prior to experimentation leading to a single calculated deposition of 42.2 ± 1.9 µg nano- TiO₂ (exposed) or 0µg (control). Animals were anesthetized, estrous status verified, and prepared for in situ assessment of leukocyte trafficking and vascular function by means of intravital microscopy, Uterine basal arteriolar reactivity was stimulated using iontophoretically applied chemicals: acetylcholine (ACh, 0.025 M; 20, 40, 100, 200 nA), sodium nitroprusside (SNP, 0.05 M; 20, 40, 100 nA), phenylephrine (PE, 0.05 M; 20, 40, 100 nA). Finally, adenosine (ADO, 10⁻⁴ M) was superfused over the tissue to identify maximum diameter. In situ vessel reactivity after exposure was significantly blunted based on estrous stage, but not at late-stage pregnancy. Local uterine venular leukocyte trafficking and systemic inflammatory markers were also significantly affected during preparatory (proestrus), fertile (estrus), and infertile (diestrus) periods after ENM inhalation. Overall, these deficits in reactivity and increased inflammatory activity may impair female fertility after ENM exposure.

Maternal engineered nanomaterial inhalation during gestation alters the fetal transcriptome

Background

The integration of engineered nanomaterials (ENM) is well-established and widespread in clinical, commercial, and domestic applications. Cardiovascular dysfunctions have been reported in adult populations after exposure to a variety of ENM. As the diversity of these exposures continues to increase, the fetal ramifications of maternal exposures have yet to be determined. We, and others, have explored the consequences of ENM inhalation during gestation and identified many cardiovascular and metabolic outcomes in the F1 generation. The purpose of these studies was to identify genetic alterations in the F1 generation of Sprague-Dawley rats that result from maternal ENM inhalation during gestation. Pregnant dams were exposed to nano-titanium dioxide (nano-TiO₂) aerosols (10 ± 0.5 mg/m³) for 7-8 days (calculated, cumulative lung deposition = 217 ± 1 μg) and on GD (gestational day) 20 fetal hearts were isolated. DNA was extracted and immunoprecipitated with modified chromatin marks histone 3 lysine 4 tri-methylation (H3K4me3) and histone 3 lysine 27 tri-methylation (H3K27me3). Following chromatin immunoprecipitation (ChIP), DNA fragments were sequenced. RNA from fetal hearts was purified and prepared for RNA sequencing and transcriptomic analysis. Ingenuity Pathway Analysis (IPA) was then used to identify pathways most modified by gestational ENM exposure.

Results

The results of the sequencing experiments provide initial evidence that significant epigenetic and transcriptomic changes occur in the cardiac tissue of maternal nano-TiO₂ exposed progeny. The most notable alterations in major biologic systems included immune adaptation and organismal growth. Changes in normal physiology were linked with other tissues, including liver and kidneys.

Conclusions

These results are the first evidence that maternal ENM inhalation impacts the fetal epigenome.

Electronic supplementary material

The online version of this article (10.1186/s12989-017-0239-8) contains supplementary material, which is available to authorized users.

Hemispheric asymmetry of the frontolimbic cortex in young adults with borderline personality disorder

OBJECTIVE

Although the frontolimbic cortex has been implicated in borderline personality disorder (BPD), information about possible asymmetries in this region in patients with BPD is limited. This study aimed to examine whether frontolimbic cortex asymmetries differ between patients with BPD and healthy individuals.

METHODS

The brains of 30 young adult patients with BPD and 32 healthy control subjects were scanned with magnetic resonance imaging (MRI). The participants completed self-report scales assessing impulsivity, affect intensity and other psychological variables. Gray matter volume, surface area, and cortical thickness in regions of interest (ROIs), namely anterior insula (AI) and anterior cingulate cortex (ACC) were determined and the data were probed for hemisphere-group interactions.

RESULTS

Relative to controls, patients with BPD had reduced cortical thickness in left ACC and less surface area and gray matter volume in left AI. Significant group-hemisphere interactions were observed for gray matter volume and surface area of AI and for cortical thickness of ACC. Post hoc analysis showed that the BPD patients had greater frontolimbic cortex asymmetry than healthy controls; furthermore, greater asymmetry of AI&ACC correlated with a higher score in attention subscale of Barratt Impulsiveness Scale.

CONCLUSION

Patients with BPD have greater frontolimbic asymmetry than healthy individuals.

Stress-induced suppression of neuropeptide Y-induced hunger in anorexic chicks involves corticotrophin-releasing factor signalling and the paraventricular nucleus of the hypothalamus

The Virginia lines of chickens have been selected for low (LWS) or high (HWS) juvenile body weight and have different severities of anorexia and obesity, respectively. The LWS that are exposed to stressors at hatch are refractory to neuropeptide Y (NPY)-induced food intake and the objective of the present study was to determine the underlying mechanisms. Chicks were exposed to a stressor (-20°C for 6 minutes and 22°C and delayed access to food for 24 hours) after hatching and the hypothalamic nuclei, including the lateral hypothalamus (LH), paraventricular nucleus (PVN), ventromedial hypothalamus (VMH) and arcuate nucleus (ARC), were collected 5 days later. In LWS but not HWS, stress exposure up-regulated corticotrophin-releasing factor (CRF), CRF receptor subtypes 1 and 2 (CRFR1 and CRFR2, respectively), melanocortin receptor 4 and urocortin 3 in the PVN, as well as CRFR2 mRNA in the VMH and ARC. In LWS, stress exposure was also associated with greater NPY and NPY receptor subtype 5 mRNA in the ARC and PVN, respectively, as well as decreased agouti-related peptide mRNA in the ARC. In HWS, stress exposure was associated with increased CRFR1 and decreased cocaine- and amphetamine-regulated transcript in the ARC and PVN, respectively. Refractoriness of the food intake response to NPY in LWS may thus result from the over-riding anorexigenic tone in the PVN associated with CRF signalling. Indeed, the orexigenic effect of NPY was restored when LWS were injected with a CRF receptor antagonist, astressin, before stress exposure. The results of the present study provide insights into the molecular basis of eating disorders and suggest that CRF signalling in the PVN may exacerbate the anorexic phenotype in the presence of environmental stressors.

A new dispersion interferometer on HL-2A

In order to avoid a fringe jump caused by high plasma density and pellet injection [Y. Zhou et al., Rev. Sci. Instrum. 87, 11E107 (2016)], a new CO₂ dispersion interferometer is designed and commissioned on HL-2A for average line-density measurement and density feedback control. The second harmonic technology in this system eliminates the phase shift caused by mechanical vibration. Signals are processed by a digital phase comparator and can be monitored in real time. A series of experiments are conducted to study the characteristics of the system such as a second harmonic coefficient and long-term stability. The resolution of density measurement is less than 8 × 10¹⁷/m³, and the experiment result on HL-2A demonstrates the interferometer's capability to track plasma density evolution with rapid change. The system also shows good stability against mechanical vibrations.

Adolescent Health Risk and Behavior Survey: A School Based Survey in Central Nepal

Background A comprehensive study of adolescent health risk specific to the Dhulikhel catchment area has not been performed. Objective This survey assesses trends in demographics, nutrition, hygiene and related infrastructure, causes of injury, violence, mental health, substance abuse, and menstrual hygiene. Method A 40 question survey was adapted from the Center for Disease Control (CDC) Youth Risk Behavior Surveillance System, translated into the Nepali language, and administered to 1200 students in eight different schools in central Nepal. Descriptive statistics were used to summarize the data. Result The data has identified nutrition, infrastructure, mental health, and menstrual hygiene as areas for improvement. The number of adolescents who reported going hungry some, most, or all of the time (30.5%, 25.8%, 13.9%) reveals a need for better food access. Approximately 44.5 % of students had no access to soap and water at school. Students who endorse dissatisfaction with themselves was 6.5% and those with suicidal ideation or attempt was 11.8% of the surveyed population. A significantly greater percentage of students who reported suicidal ideation also reported engaging in behaviors related to physical violence, substance abuse, being dissatisfaction with themselves, insomnia due to anxiety, and loneliness. Of the female students, 40.1% reported missing school at least once in the last three months due to their period. Conclusion This data shows a need for better food access, improved infrastructure in schools in central Nepal, and the need to address the prevalence of mental health issues through program interventions.

MiR-146a inhibits proliferation and induces apoptosis in murine osteoblastic MC3T3-E1 by regulating Bcl2

OBJECTIVE

The dysregulation of proliferation and apoptosis plays a significant role in the pathogenesis of hormone-induced osteonecrosis of femoral head (ONFH). The research aimed to explore the regulatory role of miR-146a in dexamethasone (DEX)-induced proliferation and apoptosis change in MC3T3-E1 cells from murine osteoblastic.

MATERIAL AND METHODS

In this study, MC3T3-E1 was co-cultured with 10-7 DEX for 6 h, then RT-PCR was employed to test the expression level of miR-146a and Bcl2. CCK8 assay and flow cytometry were adopted to verify miR-146a could regulate proliferation and apoptosis. After transfected MC3T3-E1 with mimics and inhibitor, RT-PCR and Western blot was used to detect Bcl2 expression level.

RESULTS

In DEX treated MC3T3-E1 cells showed higher MiR-146a expression level and lower Bcl2 expression level. MiR-146a could inhibit proliferation and promotes apoptosis in murine osteoblastic MC3T3-E1 cells. Additionally, Bcl2 gene is regulated by MiR-146a.

CONCLUSIONS

The MiR-146a expression level increased, while Bcl2 has low expression level in dexamethasone treated MC3T3-E1 cells. MiR-146a regulates proliferation and apoptosis of mouse bone cells. The low expression level of Bcl2 in DEX treated MC3T3-E1 cells is caused by increased MiR-146a level.

A new high sensitivity far-infrared laser interferometer for the HL-2A tokamak

A new four-chord Michelson-type formic acid (HCOOH, λ = 432.5 μm) laser interferometer has been successfully commissioned on the HL-2A tokamak to measure the electron density and density fluctuations. Due to the employment of the two-laser heterodyne technique, the time resolution of the interferometer reached 1.0 microseconds (μs). Four chords of line electron densities with a line-averaged density resolution 2 × 10¹⁶/m³ were obtained in a recent HL-2A experimental campaign, and detailed electron density fluctuations, caused by events such as edge localized mode, sawtooth precursor-oscillations, and energetic particle driven instabilities, were distinctly measured. In particular, the high-frequency electron density fluctuations (up to 500 kHz) caused by the reversed shear Alfvénic eigenmode were observed by the internal two interferometry channels, and their fluctuation location could be approximately identified from the spectra characteristics of multi-chord line electron densities.

Differential expression of appetite-regulating genes in avian models of anorexia and obesity

Chickens from lines that have been selected for low (LWS) or high (HWS) juvenile body weight for more than 57 generations provide a unique model by which to research appetite regulation. The LWS display different severities of anorexia, whereas all HWS become obese. In the present study, we measured mRNA abundance of various factors in appetite-associated nuclei in the hypothalamus. The lateral hypothalamus (LHA), paraventricular nucleus (PVN), ventromedial hypothalamus (VMH), dorsomedial nucleus (DMN) and arcuate nucleus (ARC) were collected from 5 day-old chicks that were fasted for 180 minutes or provided with continuous access to food. Fasting increased neuropeptide Y receptor subtype 1 (NPYR1) mRNA in the LHA and c-Fos in the VMH, at the same time as decreasing c-Fos in the LHA, neuropeptide Y receptor subtype 5 and ghrelin in the PVN, and neuropeptide Y receptor subtype 2 in the ARC. Fasting increased melanocortin receptor subtype 3 (MC3R) expression in the DMN and NPY in the ARC of LWS but not HWS chicks. Expression of NPY was greater in LWS than HWS in the DMN. neuropeptide Y receptor subtype 5 mRNA was greater in LWS than HWS in the LHA, PVN and ARC. Expression of orexin was greater in LWS than HWS in the LHA. There was greater expression of NPYR1, melanocortin receptor subtype 4 and cocaine- and amphetamine-regulated transcript in HWS than LWS and mesotocin in LWS than HWS in the PVN. In the ARC, agouti-related peptide and MC3R were greater in LWS than HWS and, in the VMH, orexin receptor 2 and leptin receptor were greater in LWS than HWS. Greater mesotocin in the PVN, orexin in the LHA and ORXR2 in the VMH of LWS may contribute to their increased sympathetic tone and anorexic phenotype. The results of the present study also suggest that an increased hypothalamic anorexigenic tone in the LWS over-rides orexigenic factors such as NPY and AgRP that were more highly expressed in LWS than HWS in several nuclei.

Research on the A549 cell apoptosis mechanism of the nude mouse model using MenSC-sTRAIL

OBJECTIVE

To investigate the inhibitory effect of MenSC-sTRAIL on the apoptosis of A549 cells of lung cancer in a nude mouse model and the relevant molecular mechanism.

MATERIALS AND METHODS

The tumorigenesis curve of A549 cells in the nude mouse model was assayed using the growth curve plotted by the growth rate of tumor of the A549 cell nude mouse model. Cellular apoptosis was assayed using flow cytometer and Annexin V-FITC, and the effect of MenSC-sTRAIL on the expression of Bax was measured using Western blot.

RESULTS

MenSC-sTRAIL promoted the apoptosis of A549 cells. Results of the quantitative assay using Annexin V-FITC further confirmed the effect of MenSC-sTRAIL on inducing the cellular apoptosis. Western-blot results showed that MenSC-sTRAIL increased the expression of Bax.

CONCLUSIONS

MenSC-sTRAIL may vary the balance of regulation of heterodimer of Bcl-2 and Bax, which can induce the apoptosis of A549 cells.

Abnormal white matter structural connectivity in treatment-naïve young adults with borderline personality disorder

OBJECTIVE

The pathogenesis of borderline personality disorder (BPD) is not well understood. We examined the microstructure of white matter in patients with BPD.

METHOD

Treatment-naïve young adult with BPD (N = 30) and young-adult healthy controls (HCs; N = 31) were subjected diffusion tensor imaging (DTI). Microstructural parameters were analyzed via tract-based spatial statistics (TBSS) and post hoc tractography.

RESULTS

TBSS analysis revealed that, relative to the HC group, the BPD group had significantly lower fractional anisotropy (FA) values in the genu and body of the corpus callosum (CC), right superior corona radiate, right anterior corona radiate, as well as higher radial diffusivity (RD) in the left anterior thalamic radiation. Tractography showed that FA values of fiber bundles passing through the fornix were significantly reduced in BPD group relative to HCs. No significant correlations were observed between clinical symptom and DTI indices in BPD group (FDR corrected).

CONCLUSION

Focal microstructural alterations were found in BPD group, mainly in the limbic system and CC. The present findings support the fronto-limbic disconnectivity hypothesis and suggest that abnormal maturation of white matter structures may play an important role in mechanism of BPD.

The conceptual design of interferometer/polarimeter system on HL-2M

HL-2M is a new medium-sized tokamak with major radius of 1.78 m, minor radius of 0.65 m, and aspect ratio of 2.8 and will be finished soon. In the conceptual design, a double-pass, horizontal view, multi-channel far-infrared (FIR) laser interferometer/polarimeter system (at 432 μm) is proposed to simultaneously measure the phase change and the Faraday rotation for density and current profile reconstruction. A vertical CO₂ dispersion interferometer system (with wavelength of 10.6 μm and 5.3 μm) is designed to measure the line density, which will mainly be used for density feedback. The performance of the system is expected to meet the requirement of the measurements on HL-2M, with phase accuracy ∼0.1°, time resolution ∼1 μs, spatial resolution ∼7.2 cm, and density measurement range of 1 × 10 ¹⁸-1 ×10²¹ m^-3.