Impairment of ovarian follicular development caused by titanium dioxide nanoparticles exposure involved in the TGF-β/BMP/Smad pathway

Titanium dioxide nanoparticles (TiO₂ NPs) have been shown to induce reproductive system damages in animals. To better underline how TiO₂ NPs act in reproductive system, female mice were exposed to 2.5, 5, or 10 mg/kg TiO₂ NPs by gavage administration for 60 days, the ovary injuries, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels as well as ovarian follicular development-related molecule expression were investigated. The results showed that TiO₂ NPs exposure resulted in reduction of ovary weight and inhibition of ovarian follicular development. Furthermore, the suppression of follicular development was demonstrated to be closely related to higher FSH and LH levels, and higher expression of activin, follistatin, BMP2, BMP4, TGF-β1, Smad2, Smad3, and Smad4 as well as decreased inhibin-α expression in mouse ovary in a dose-dependent manner. It implies that the impairment of ovarian follicular development caused by TiO₂ NPs exposure may be mediated by TGF-β signal pathway.

POS0541 PREDICTORS OF REMISSION IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH UPADACITINIB OR ADALIMUMAB IN THE SELECT-COMPARE PHASE 3 STUDY: CLINICAL STATUS AT WEEK 12, BUT NOT STANDARD LABORATORY MEASURES, PROVIDES THE BEST CURRENT PREDICTOR OF REMISSION AT WEEK 26

Background

Upadacitinib (UPA, 15 mg QD), an oral JAK1 selective inhibitor, showed greater efficacy compared to adalimumab (ADA, 40 mg EOW) at week 12 in patients with active rheumatoid arthritis (RA) on background methotrexate (MTX) in the SELECT-COMPARE phase 3 study1. Treatment with UPA compared to ADA resulted in a larger proportion of patients reaching CDAI Remission (REM) at week 26 (23% vs. 14%, p-value ≤ 0.001). Because remission is the goal in managing RA, it is of clinical relevance to identify early during the treatment course who might be able to achieve this state. It has been reported that early response to therapy with UPA was associated with achieving CDAI REM at week 262. In parallel, it has been reported that reduction in monocyte can predict DAS28-ESR REM in RA patients treated with anti-TNF therapy3. However, the relative predictive values of clinical and standard laboratory measures have not been compared side-by-side.

Objectives

To determine post-hoc the relative predictive values of selected clinical and standard laboratory measures collected at week 12 for identifying RA patients who will be in CDAI REM at week 26 upon treatment with UPA or ADA.

Methods

Clinical (CDAI, SDAI, and DAS28-CRP) and laboratory data (CRP, ESR, CBC with differential, and Lipids) for all available patients enrolled in the SELECT-COMPARE phase 3 study were included in this post-hoc analysis (UPA: n =623 [CDAI REM at wk26 = 23.8%]; ADA: n = 316 [CDAI REM at wk 26 = 14.2%]). Patients who switched treatment between weeks 14 and 22 due to not reaching at least 20% improvement in tender and swollen joints were classified as non-responders for CDAI REM at week 26. The predictive value of clinical and laboratory endpoints recorded at week 12 for determining CDAI REM status at week 26 was assessed by univariate logistic regression. We report the performance of each model as ROC AUC with a cutoff of 0.75 for meaningful predictive value.

Results

For both patients treated with UPA and those treated with ADA, clinical disease activity status measures (CDAI, SDAI, and DAS28-CRP) and relative change in disease activity measures (Percent Change [PCHG] in CDAI, PCHG in DAS28-CRP, and PCHG in SDAI) at week 12 resulted in the highest predictive performance for determining CDAI REM status at week 26 (Figure 1). In contrast, none of the selected standard laboratory measures (CRP, ESR, CBC with differential, and Lipids) reached a meaningful predictive value (ROC AUC < 0.75). Of note, cell numbers and changes in cell numbers (including Neutrophils Lymphocytes, Basophils, Eosinophils, and Monocytes) at week 12 had no meaningful predictive value for determining CDAI REM at week 26.

Figure 1.

Univariate Logistic Models to Predict CDAI REM at Week 26 in Active RA Patients who had an Inadequate Response to MTX: ROC Analysis AUC.

Legend: All evaluated parameters were recorded at Week 12; CHG = Change from Baseline to Week 12; PCHG = Percent Change from Baseline to Week 12

Conclusion

This analysis suggests that standard laboratory measures (CRP, ESR, CBC with differential, and Cholesterol) at week 12 do not represent useful predictors for REM at week 26 in csDMARD-IR RA patients. In particular, blood cell numbers and the changes in these measures at week 12 do not provide additional predictive value in our analyses, contrasting with the results from Amarnani and colleagues3. Hence, clinical disease activity levels and changes in these measures at week 12 remain adequate predictors of CDAI REM at week 26. Still, the absolute predictive performance of clinical measures remains suboptimal, highlighting the need to dedicate continued efforts to identify and validate improved predictors of long-term REM in RA.

References

[1]Fleischmann, R. et al. Arth Rheumatol71, 1788-1800 (2019).

[2]Kavanaugh, A. et al. J Clin Rheumatol27, S81-S81 (2021).

[3]Amarnani, R. et al. Ann Rheum Dis80, 448-449 (2021).

Acknowledgements

AbbVie, Inc was the study sponsor, contributed to the study design, data collection, analysis & interpretation, and writing, reviewing, and approval of the final version.

Disclosure of Interests

Thierry Sornasse Shareholder of: AbbVie, Employee of: AbbVie, Fang Cai Shareholder of: AbbVie, Employee of: AbbVie, Feng Hong Shareholder of: AbbVie, Employee of: AbbVie, Samuel Anyanwu Shareholder of: AbbVie, Employee of: AbbVie, In-Ho Song Shareholder of: AbbVie, Employee of: AbbVie, Marwan Bukhari Speakers bureau: Bristol-Myers Squib, UCB celltech, Roche/Chugai, Pfizer, Abbvie, Merck, Mennarini, Sanofi-aventis, Eli-Lilly, Janssen, Amgen, Novartis and Gilead, Paid instructor for: honoraria from educational groups revalidaid and TREG consultants.

Lipid accumulation product is a reliable indicator for identifying metabolic syndrome: the China Multi-Ethnic Cohort (CMEC) Study

BACKGROUND

Previous studies have shown that lipid accumulation product (LAP) was associated with the risk of cardiometabolic disease. It is not clear whether LAP could be used as a marker to identify metabolic syndrome (MetS) among Chinese ethnic groups.

AIM

To assess the reliability of LAP as a maker to identify MetS among Dong adults.

DESIGN

Population-based cross-sectional study.

METHOD

We included 6494 Dong individuals (1403 patients) aged 30-79 years from southwest China. MetS was established by Chinese Diabetes Society. Logistic regression model was utilized to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Receiver operating characteristic (ROC) curve was utilized to calculate area under the ROC curve (AUC) and 95% CIs to obtain the identification ability for MetS.

RESULTS

The risk of MetS was increased with per 5 units increase of LAP (OR 1.37 [95% CI, 1.34-1.39]). Similar results were found in subgroup analyses and sensitivity analyses. Clustered metabolic risk associated with per 5 units increase of LAP was observed for people with 1 (OR 1.59 [95% CI, 1.53-1.65]), 2 (2.15 [2.06-2.24]), 3 (2.59 [2.48-2.71]), 4 (2.81 [2.69-2.95]) and 5 (3.03 [2.87-3.21]) MetS components. LAP presented higher AUC (0.915 [95% CI, 0.907-0.923]) than other included obesity indices (P < 0.05).

CONCLUSION

These data support evidence that LAP was related to the risk of MetS, had a high AUC and could be a reliable index for identifying MetS patients among Dong adults in Chinese.

A dose-response meta-analysis to evaluate the relationship between high-density lipoprotein cholesterol and all-cause and cardiovascular disease mortality

PURPOSE

Previous studies have not fully described the relationship between high-density lipoprotein cholesterol (HDL-C) and death risks from all cause and cardiovascular disease (CVD). This study quantitatively evaluates HDL-C-mortality associations.

METHODS

Embase and PubMed databases were searched for relevant articles published up to 1 June 2019. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs). We used restricted cubic splines to model the dose-response association.

RESULTS

We identified 32 prospective cohort studies including 369,904 participants and 33,473 total deaths (9426 CVD deaths). Compared to the lowest HDL-C levels, all cause and CVD mortality risks were reduced by 18% (RR 0.82; 95% CI, 0.73-0.93) and 36% (0.64, 0.46-0.89), respectively, for the highest HDL-C levels. All cause and CVD mortality risks were reduced by 15% (0.85, 0.79-0.92) and 23% (0.77, 0.69-0.87), respectively, with each 1 mmol/L increment of HDL-C. We found evidence of nonlinear and negative dose-response associations of HDL-C with all cause and CVD mortality (P_nonlinearity < 0.001), and the lowest death risks from all cause and CVD were observed at approximately 1.34 and 1.55 mmol/L, respectively.

CONCLUSION

HDL-C is inversely associated with all cause and CVD mortality risks under approximately 2.05 and 2.33 mmol/L, respectively. Optimal doses require investigation via clinical practice or high-quality research.

[Establishment of human colon cancer transplantation tumor model in normal immune mice]

Objective: Establishment of a new model of human primary colon cancer transplantation tumor in normal immune mice and to provide a reliable experimental animal model for studying the pathogenesis of colon cancer under normal immunity. Methods: Human colon cancer cells come from colon cancer patients who underwent surgery in the Affiliated Hospital of Jining Medical College in 2017. The mice in the cell control group were inoculated with phosphate buffered solution (PBS) containing colon cancer cells, the microcarrier control group was inoculated with PBS containing microcarrier 6, and the cell-microcarrier complex group was inoculated with the PBS containing colon cancer cell-microcarrier complex. The cells of each group were inoculated under the skin of the right axilla of mice by subcutaneous injection, and the time, size, tumor formation rate and pathological changes under microscope were recorded. The transplanted tumor tissue was immunohistochemically stained with the EnVisiion two-step method, and the tumor formation rate of the transplanted tumor was judged according to the proportion of positive cells in the visual field. The polymerase chain reaction (PCR) method was used to detect the expression of human-specific Alu sequence in mice tumor tissue. Results: After inoculation with tumor cells, the mice in the cell control group and the microcarrier control group did not die and did not form tumors; the mice in the cell-microcarrier complex group had palpable subcutaneous tumors in the right axillary subcutaneously on the 5th to 7th days after inoculation, and tumor formation rate is 67% (10/15), and the tumor volume can reach about 500 mm(3) 2 to 3 weeks after vaccination. The immunohistochemistry results showed that CK20, CDX-2 and carcinoembryonic antigen were all positively expressed. The PCR results showed that the expression of human-specific Alu sequence can be detected in the transplanted tumor tissue of tumor-bearing mice. Conclusion: Human primary colon cancer cells used microcarrier 6 as a carrier to form tumors in normal immunized mice, and successfully established a new model of human colon cancer transplantation tumor in normal immune mice.

Damage to the Blood Brain Barrier Structure and Function from Nano Titanium Dioxide Exposure Involves the Destruction of Key Tight Junction Proteins in the Mouse Brain

Numerous studies have proven that nano titanium dioxide (nano TiO₂) can accumulate in animal brains, where it damages the blood brain barrier (BBB); however, whether this process involves destruction of tight junction proteins in the mouse brain has not been adequately investigated. In this study, mice were exposed to nano TiO₂ for 30 consecutive days, and then we used transmission electron microscopy to observe the BBB ultrastructure and the Evans blue assay to evaluate the permeability of the BBB. Our data suggested that nano TiO₂ damaged the BBB ultrastructure and increased BBB permeability. Furthermore, we used immunofluorescence and Western blotting to examine the expression of key tight junction proteins, including Occludin, ZO-1, and Claudin-5 in the mouse brain. Our data showed that nano TiO₂ reduced Occludin, ZO-1 and Claudin-5 expression. Taken together, nano TiO₂-induced damage to the BBB structure and function may involve the destruction of key tight junction proteins.

Nano-TiO₂ Reduces Testosterone Production in Primary Cultured Leydig Cells from Rat Testis Through the Cyclic Adenosine Phosphate/Cyclic Guanosine Phosphate/Epidermal Growth Factor Receptor/Matrix Metalloproteinase Signaling Pathway

Nano-titanium dioxide (nano-TiO₂) has been shown to inhibit testosterone synthesis in male mice or rats; however, the mechanisms underlying these effects have yet to be elucidated. In this study, we investigated whether the inhibition of testosterone synthesis by nano-TiO₂ on Leydig cells (LCs) was related to the dysfunction of the cAMP/CGMP/EGFR/MMP signaling pathway in primary cultures of LCs prepared from rat testis exposed to nano-TiO₂. We found that the early apoptotic rate of LCs increased by 4.34 and 4.94 times, respectively, after exposure to 20 g/mL and 40 g/mL nano-TiO₂ ; we also found that NO increased by 1.1 and 2.86 times, respectively. ROS increased by times of 0.71, 3.15 and 3.43; RNS increased by 0.62, 1.34 and 1.14 times; and SOD activity decreased by 18.3%, 28.16%, and 67.6%, respectively, when the concentration of nano-TiO₂ was 10, 20 and 40 g/mL. These results indicated that nano-TiO₂ treatment resulted caused damage to the LCs, including an imbalance of oxidation and antioxidation. Following nano-TiO₂ treatment, the cAMP content had decreased by 48%, 48% and 47.6%; cGMP content had decreased by 18.7%, 52.2% and 56.7%; the levels of ATP in the LCs had decreased by 15.15%, 45.75% and 66.67%; the expression of HCGR protein had decreased by 26.7%, 45.07% and 74.64%; the expression of LHR protein had decreased by 18.3%, 28.16% and 67.6%; and the levels of T had decreased by 34.48%, 46.62% and 44.12%. Collectively, our results indicated that the inhibition of testosterone production by nano-TiO₂ is related to the dysfunction of the cAMP/CGMP/EGFR/MMP signaling pathway.

Potential predictive biomarkers of adalimumab response in patients with hidradenitis suppurativa

BACKGROUND

Adalimumab provides significant efficacy for patients with hidradenitis suppurativa (HS), which was demonstrated by at least 50% of patients achieving a clinical response by week 12 that was maintained through to week 168 in the PIONEER trials.

OBJECTIVES

To identify whether there are biomarkers that could predict adalimumab response, as well as markers that differentially respond to adalimumab in patients with HS.

METHODS

Baseline and week-12 plasma samples from the PIONEER studies were used to assess the levels of circulating proteins by multiplex and enzyme-linked immunosorbent assays.

RESULTS

Analyses revealed significantly higher high-sensitivity C-reactive protein (hs-CRP) and chemokine (C-C motif) ligand (CCL) 16 (HCC-4) levels in nonresponders at baseline and identified a multivariate response signature of calprotectin, fractalkine and HCC-4, reaching an 86% predictive accuracy rate for adalimumab response. Additionally, post-treatment reduction of plasma C-X-C motif chemokine ligand (CXCL)9, CXCL8 (interleukin-8) and CCL19 (macrophage inflammatory protein 3β) were greater in adalimumab super-responders than in nonresponders (P = 0·026, P = 0·044 and P = 0·026, respectively). These cytokines are involved in the recruitment of innate and adaptive inflammatory cells, and/or stimulation of certain inflammatory responses, suggesting that these pathways could be disease drivers in adalimumab nonresponders.

CONCLUSIONS

These initial results suggest HCC-4, calprotectin and fractalkine could be potential predictive biomarkers of adalimumab response in HS and identified possible tumour necrosis factor-independent disease pathways.

Routine antiseptic baths and MRSA decolonization: diverse approaches across Singapore's acute-care hospitals

To determine the variation in practices on meticillin-resistant Staphylococcus aureus (MRSA) surveillance and management of MRSA-colonized patients amongst 17 acute healthcare facilities in Singapore, the Ministry of Health convened a sharing session with Infection Prevention and Control Leads. All hospitals practised close to universal MRSA entry swabbing in keeping with national policy. There were, however, major variations in the response to both positive and negative surveillance swabs across facilities including the role of routine antiseptic bathing and MRSA decolonization. Most undertaking decolonization considered its role to be in 'bioburden reduction' rather than longer-term clearance.

Molecular mechanisms associated with oxidative damage in the mouse testis induced by LaCl3

China is the world's largest rare earth producer and exporter, previous studies have shown that rare earth elements can cause oxidative damage in animal testis. However, the molecular mechanisms underlying these observations have yet to be elucidated. In this paper, male mice were fed with different doses (10, 20, and 40 mg/kg BW) of LaCl₃ for 90 consecutive days, regulatory role of nuclear factor erythroid-2 related factor 2 (Nrf-2)/antioxidant response element (ARE) pathway in testicular oxidative stress induced by LaCl₃ were investigated. Analysis showed that LaCl₃ exposure could lead to severe testicular pathological changes and apoptosis in spermatogenic cells, it up-regulated the peroxidation of lipids, proteins and DNA, and induced the excessive levels of reactive oxygen species (ROS) production in mouse testis, reduced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione S epoxide transferase (GST) as well as the glutathione (GSH) content. Furthermore, exposure to LaCl₃ also downregulated the expression of Nrf2 and its target gene products, including heme oxygenase 1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H dehydrogenase [quinine] 1(NQO1), protein kinase C (PKC), and phosphatidylinositol 3-kinase (PI3K), but upregulated the expression of Kelch-like ECH-related protein 1 (Keap1) in damaged mouse testes. Collectively, our data imply that the oxidative damage induced by LaCl₃ in testis was related to inhibition of the Nrf-2/AREs pathway activation.

The critical role of hippocampal dopamine in the pathogenesis of hepatic encephalopathy

The pathogenesis of hepatic encephalopathy (HE) has been generally linked to blood ammonia, gamma-aminobutyric acid and serotonin. However, the exact mechanism remains unclear. In the present study, we aimed to explore the role of hippocampal dopamine (DA) and its receptors in the pathogenesis of HE through the use of behavioral testing, western blotting, and immunofluorescence staining in normal rats, HE model rats and rats treated with the DA precursor-levodopa (L-DOPA). HE model rats manifested fibrotic livers and showed serious behavioral disorders. They also had significantly lower hippocampal DA content and increased expression of both D1 and D2 receptors relative to normal rats. After treatment with L-DOPA, the HE model rats showed normal behavior and expression of D1 returned to normal levels. Furthermore, pretreatment with the D1 antagonist SCH23390 blocked the therapeutic effect of L-DOPA on behavior in HE model rats. Taken together, these results clarify that the decrease in hippocampal DA plays a role in the pathogenesis of HE and that this effect is mediated by D1. These findings provide new evidence for the pathogenesis of HE.

Molecular mechanism of mice gastric oxidative damage induced by nanoparticulate titanium dioxide

Background

Nanoparticulate titanium dioxide (Nano-TiO₂) has been widely used in food industry, and it has been demonstrated to have adverse effects on mice and human stomach, but its mechanism is rarely concerned. The aim of this study is to determine the effects of nano-TiO₂ on the stomach and confirm the role of oxidative stress and apoptosis in the mice gastric damage caused by nano-TiO₂, as well as its molecular mechanisms.

Methods

Mice were continuously exposed to nano-TiO₂ with 1.25, 2.5 and 5 mg/kg bw by intragastric administration for 9 months in the present study. The ultrastructure, levels of reactive oxygen species (ROS) and peroxides, activities of antioxidant enzymes and mitochondria-related enzymes, ATP contents as well as apoptosis-related factors expression in mice stomach were examined.

Results

Oxidative stress, apoptosis and nano-TiO₂ aggregation were found in gastric mucosal smooth muscle cells after nano-TiO₂ exposure. Nano-TiO₂ exposure also resulted in the over-production of ROS and peroxides, decrease of ATP production and activities of antioxidant enzymes and mitochondria-related ATPases, upregulation of apoptosis-related factors including γH2AX, Cyt c, caspase 3, and p-JNK expression, and down-regulation of Bcl-2 expression in mice stomach.

Conclusions

The gastric toxicity of mice induced by chronic exposure to low dose nano-TiO₂ may be associated with oxidative stress and mitochondria-mediated apoptosis in mice.

Titanium Dioxide Inhibits Hippocampal Neuronal Synapse Growth Through the Brain-Derived Neurotrophic Factor-Tyrosine Kinase Receptor B Signaling Pathway

Nanoparticulate titanium dioxide (nano-TiO₂) is a commonly used nanoparticle material and has been widely used in the fields of medicine, cosmetics, construction, and environmental protection. Numerous studies have demonstrated that nano-TiO₂ has toxic effects on neuronal development, which lead to defects in learning and memory functions. However, it is still unclear whether nano-TiO₂ inhibits the development of synapse and the underlying molecular mechanism is still unknown. In this study, nano-TiO₂ was administered to rat primary hippocampal neurons for 24 h to investigate the underlying molecular mechanisms behind the inhibition of neuronal synaptic development by nano-TiO₂. We used hippocampal neurons as a model to study the effect of nano-TiO₂ on synaptic development. Our results demonstrated that dendritic development that represented synaptic plasticity in hippocampal neurons was significantly inhibited in a concentration-dependent manner after exposure to nano-TiO₂ for 24 h. Experiments with varying concentrations of nano-TiO₂ (5, 15, and 30 g/mL) indicated that the apoptotic rate of hippocampal neurons increased, development of neuronal synapses were inhibited, and synaptic densities decreased by 24.29%, 54.29%, and 72.86%, respectively, in post-treatment with nano-TiO₂. Furthermore, the results indicated that the expressions of Synapsin I (SYN I) and postsynaptic density 95 (PSD95) in neuron synapse were also significantly inhibited, particularly SYN I decreased by 18.43%, 37.2%, and 51.6%, and PSD95 decreased by 16.02%, 24.06%, and 38.74% after treatment with varying concentrations of nano-TiO₂, respectively. In addition, experiments to assess the BDNF-TrkB signaling pathway indicated that nano-TiO₂ inhibited the expressions of key proteins in the downstream MEK/ERK and PI3K/Akt signaling pathways by inhibiting the expression of BDNF. With concentrations of nano-TiO₂ at 5, 15, and 30 μg/mL, the expression of BDNF decreased by 22.64%, 33.3%, and 53.58% compared with the control group. Further, the expression ratios of downstream key proteins p-CREB/CREB decreased by 3.03%, 18.11%, and 30.57%; p-ERK1/2/ERK1/2 ratios decreased by 19.11%, 28.82%, and 58.09%, and p-Akt1/Akt1 ratios decreased by 1.92%, 27.79%, and 41.33%, respectively. These results demonstrated that nano-TiO₂ inhibited the normal function of the BDNF-TrkB signaling pathway, which is closely related to neuronal synapse. Thus, it can be hypothesized that the inhibition of neuronal synaptic growth by nano-TiO₂ may be related to the inhibition of BDNF-TrkB signaling pathway.

Liver Inflammation and Fibrosis Induced by Long-Term Exposure to Nano Titanium Dioxide (TiO₂) Nanoparticles in Mice and Its Molecular Mechanism

Titanium dioxide (TiO₂) and nano-sized titanium dioxide (nano-TiO₂), which are used in food production, may be harmful to the body. Long-term exposure to nano-TiO₂ can lead to hepatic injury; however, the effect of nano-TiO₂ on liver fibrosis and the underlying mechanism remain unclear. The TGF-β/Smad/MAPK/Wnt signaling pathway is important for tissue fibrosis. In this study, mice were fed nano-TiO₂ (2.5, 5, and 10 mg/kg body weight) for nine consecutive months to investigate its effect on liver fibrosis. Nano-TiO₂ induced hepatic inflammatory cell infiltration and hepatic fibrosis and upregulated the expression of HIF-1α (+75-fold to +2.38-fold), Wnt3 (+12% to +135%), Wnt4 (1.33-fold to 6-fold), NF-κB (+3.13% to +34.38%), TGF-β1 (+1307-fold to +1.85-fold), TGF-β1R (+0.8-fold to 1.33-fold), Smad-2 (+0.58-fold to +1.58-fold), ILK (+0.43-fold to +1.19-fold), ECM (+1.82-fold to 2.36-fold), calpain 2 (+0.11-fold to +0.78-fold), α-SMA (+0.63-fold to +1.56-fold), c-Myc (+0.27-fold to +0.46-fold), and collagen I (+8% to +36%), and increased the phosphorylation level of p38MAPK (+66.67% to +153.33%) in inflammatory and fibrotic liver tissues, whereas it downregulated cyclin D (-6.25% to -43.75%) and decreased the phosphorylation levels of GSK-3β (-3.12% to -46.88%) and β-catenin (-19.57% to -45.65%). These results indicate that hepatic fibrosis induced by nano-TiO₂ is mediated by the TGF-β/Smads/MAPK/Wnt signaling pathway. This study provides insight into the mechanism underlying hepatic toxicity induced by nano-TiO₂ .

Spermatogenic Apoptosis and the Involvement of the Nrf2 Pathway in Male Mice Following Exposure to Nano Titanium Dioxide

Titanium dioxide nanoparticles (TiO₂ NPs) are largely manufactured and extensively applied for the treatment of environmental pollution. Studies have proved that exposure to TiO₂ NPs leads to toxicity of the reproductive system. However, very few studies have highlighted the involvement of nuclear factor erythroid-2 related factor 2 (Nrf2) under TiO₂ NPinduced spermatogenic apoptosis. Our findings suggested that TiO₂ NPs could cross the blood-testis barrier and were aggregated or deposed in spermatogenic cells, which resulted in spermatogenic apoptosis. Furthermore, exposure to TiO₂ NPs caused an overproduction of reactive oxygen species and the peroxidation of lipids, proteins, and DNA. Such exposure also caused significant decreases in the activities of SOD, GSH-PX, GST, and GSH content in the testis. Importantly, exposure to TiO₂ NPs resulted in an up-regulation of Keap1 expression and a down-regulation of Nrf2 and its target gene products, NQO1, HO-1, GCLC, PKC, and PI3K. The present study implies that TiO₂ NPs could lead to spermatogenic apoptosis, and Nrf2 is the initial factor that responded to such reproductive toxicity by regulating the expression of antioxidative proteins.

Molecular mechanism of nanoparticulate TiO2 induction of axonal development inhibition in rat primary cultured hippocampal neurons

Numerous studies have demonstrated the in vitro and in vivo neurotoxicity of nanoparticulate titanium dioxide (nano-TiO₂ ), a mass-produced material for a large number of commercial and industrial applications. The mechanism of nano-TiO₂ -induced inhibition of axonal development, however, is still unclear. In our study, primary cultured hippocampal neurons of 24-hour-old fetal Sprague-Dawley rats were exposed to 5, 15, or 30 μg/mL nano-TiO₂ for 6, 12, and 24 hours, and the toxic effects of nano-TiO₂ exposure on the axons development were detected and its molecular mechanism investigated. Nano-TiO₂ accumulated in hippocampal neurons and inhibited the development of axons as nano-TiO₂ concentrations increased. Increasing time in culture resulted in decreasing axon length by 32.5%, 36.6%, and 53.8% at 6 hours, by 49.4%, 53.8%, and 69.5% at 12 hours, and by 44.5%, 58.2%, and 63.6% at 24 hours, for 5, 15, and 30 μg/mL nano-TiO₂ , respectively. Furthermore, nano-TiO₂ downregulated expression of Netrin-1, growth-associated protein-43, and Neuropilin-1, and promoted an increase of semaphorin type 3A and Nogo-A. These studies suggest that nano-TiO₂ inhibited axonal development in rat primary cultured hippocampal neurons and this phenomenon is related to changes in the expression of axon growth-related factors.

Nanostructured Titanium Dioxide (TiO2) Reduces Sperm Concentration Involving Disorder of Meiosis and Signal Pathway

Nano-titanium dioxide (nano-TiO2) has been widely used in food and cosmetic industries, and the medical sector. However, nano-TiO2 is potentially toxic to the reproductive system. Previous research has shown that nano-TiO2 can reduce sperm concentration but do not yet known whether this effect occurs because of dysfunctional meiosis in spermatogenic cells. In the present paper, we demonstrate that Nano-TiO2 can penetrate through the blood-testis barrier of a mouse model and enter the testicular tissue, thus causing damage to the testis and epididymis. This reduced the number of developing sperm; we demonstrated that the mechanism underlying this effect was the inhibition or destruction of meiosis in spermatogenic cells, particularly during meiosis I. We also found that the inhibition of meiosis I caused by nano-TiO2 exposure was related to dysfunctional meiosis and that the abnormal expression of meiosis-related factors. Therefore, our data demonstrate that nano-TiO2 reduces sperm concentration by disrupting meiosis and related signaling pathways.

[The effect of peroxiredoxin 2 on transforming growth factor-β1-induced fibroblast proliferation and collagen synthesis]

Objective: To investigate the effect of peroxiredoxin 2 (Prx2) overexpression on fibroblast proliferation and collagen synthesis induced by transforming growth factor-β1 (TGF-β1) . Methods: Fibroblasts were randomly divided into control group (DMEM medium) , TGF-β1 group (5 μg/L TGF-β1) , negative control group (treated with 5 μg/L TGF-β1 and transfected with empty lentiviral vector) , and Prx2 group (treated with 5 μg/L TGF-β1 and transfected with Prx2 overexpression lentiviral vector) . MTT assay was used to measure cell proliferation, immunofluorescence assay was used to measure the expression of 8-OHdG, and Western blot was used to measure the expression of p-JNK, p-P38, collagen type I, collagen type III, and Prx2. SPSS 18.0 was used for statistical analysis. The continuous data were expressed as mean±standard deviation; an analysis of variance was used for comparison between groups, and the least significant difference t-test was used for further comparison between two groups. Results: Lentiviral transfection was performed successfully, and the Prx2 group had a significant increase in the protein expression of Prx2 (P<0.05) . Compared with the control group, the TGF-β1 group had a significant increase in the proliferation ability (P<0.05) , and compared with the TGF-β1 group, the Prx2 group had a significant reduction in the proliferation ability (P<0.05) . Compared with the control group, the TGF-β1 group had significant increases in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P<0.05) ; compared with the TGF-β1 group, the negative control group had no significant changes in the expression of 8-OHdG, p-JNK, p-P38, collagen type I, and collagen type III (P>0.05) , while the Prx2 group had significant reductions in the above parameters (P<0.05) . Conclusion: Prx2 overexpression inhibits fibroblast proliferation and collagen synthesis induced by TGF-β1 through inhibiting reactive oxygen species and activating the JNK and P38 pathways.

Respiratory exposure to nano-TiO2 induces pulmonary toxicity in mice involving reactive free radical-activated TGF-β/Smad/p38MAPK/Wnt pathways

Numerous studies have shown that lung injury can be caused by respiratory exposure to nanoparticulate titanium dioxide (nano-TiO₂ ), but whether pulmonary inflammation and fibrosis are related to the activation of the TGF-β/Smad/p38MAPK/Wnt pathways remains unclear. In this study, mice were administrated nano-TiO₂ by nasal instillation for nine consecutive months, and the molecular mechanisms of nano-TiO₂ on the pulmonary toxicity of mice were examined. The findings suggested that nano-TiO₂ caused pneumonia and pulmonary fibrosis. Furthermore, the results also showed that an overproduction of reactive free radicals occurred in mouse lungs, and that the expression of TGF-β/p38MAPK/Wnt pathway-related factors, including hypoxia-inducible factor 1α (HIF-1α), transforming growth factor-β1 (TGF-β1), phosphorylated p38 mitogen activated protein kinases (p-p38MAPK), small mothers against decapentaplegic homolog 2 (Smad2), extracellular matrix (ECM), Wingless/Integrated 3 (Wnt3), Wingless/Integrated 4 (Wnt4), integrin-linked kinase (ILK), β-catenin, nuclear factor-κB (NF-κB), α-smooth muscle actin (α-SMA), c-Myc, Type I collage (collagen I), and Type collage III (collagen III) were remarkably elevated, while phosphorylated glycogen synthase kinase-3β (p-GSK-3β) expression was decreased. Those data implied that the pulmonary inflammation and fibrosis caused by nano-TiO₂ exposure may be involved in reactive free radical-mediated activation of the TGF-β/Smad/p38MAPK/Wnt pathways.

Maternal Exposure to Nanoparticulate Titanium Dioxide Causes Inhibition of Hippocampal Development Involving Dysfunction of the Rho/NMDAR Signaling Pathway in Offspring

Numerous studies have suggested that nano-TiO₂ can be translocated to the brain via the placental barrier and blood brain barrier, leading to brain damage and cognitive impairment in both mice and rat offspring. The mechanism of nanoTiO₂-induced neurotoxicity is still unclear, as is its role in the inhibition of hippocampal development. In this experiment, nano-TiO₂ was employed to investigate whether the inhibition of the hippocampal development of mice offspring involved the alterations in the Rho signaling pathway following consecutive gavage of female mice between 7-21 days postpartum. The results showed that nano-TiO₂ particles were concentrated in the hippocampus of offspring, resulting in reduced hippocampal indices and in inhibited axonal and dendritic growth. Furthermore, nano-TiO₂ downregulated expression of N-methyl-D-aspartate receptor (NR)1, NR2A, NR2B, RhoGTPase, Ras-related C1 botulinum toxin substrate (Rac1), cell division cycle42 (Cdc42), phosphorylated cAMP response element binding protein (p-CREB), p21-activated kinase (PAK) 3, and PAK1, LIMK (LIM kinase) 1, p-LIMK1, activated Cdc42 kinase (ACK), and myotonic dystrophic kinaseassociated Cdc42-binding kinase (MRCK) and increased expression of RhoA, Rho kinase (ROCK) 1 and cyclin dependent kinase (Cdk) 5 in offspring. In addition, nano-TiO₂ disrupted the balance of RhoA/Rac1, RhoA/Cdc42, and Rac1/Cdc42 ratios in the hippocampus of mice offspring. Taken together, these data imply that maternal exposure to nano-TiO₂ inhibited development of hippocampal axons and dendrites of offspring may be correlated with the dysfunction of the Rho pathway and that N-methyl-D-aspartate receptors (NMDAR) may also mediate nano-TiO₂-Rho pathway interactions.

Wnt Pathway-Mediated Nano TiO₂-Induced Toxic Effects on Rat Primary Cultured Sertoli Cells

Nanosized titanium dioxide (Nano TiO₂) has been widely used in daily lives, medicine, industry, and caused the potential reproduction toxicity for animals and human, however, the underlying molecular mechanisms for the reproductive toxicity of nano TiO₂ are still largely unclear. In the present study, when primary cultured rat Sertoli cells (SCs) were exposed to nano TiO₂, cell injury and alterations in wingless related MMTV integration site (Wnt) pathway-related factors including Wnt1, Wnt3a, Wnt5a, Wnt11, β-catenin, and p-GSK-3β expression were investigated. The results suggested that nano TiO₂ could be translocated to cytoplasm or nucleus, and decreased cell viability, and impaired morphological structures of SCs, induced apoptosis and dead of primary cultured rat SCs. Furthermore, nano TiO₂-induced the toxicity of primary cultured rat SCs was associated with increased expression of Wnt1, Wnt3a, Wnt5a, Wnt11, and β-catenin and involved with reduced p-GSK-3β expression. Therefore, this implies that nano TiO₂-induced toxic effects on SCs may be associated with Wnt signaling pathways.

Retardation of Axonal and Dendritic Outgrowth Is Associated with the MAPK Signaling Pathway in Offspring Mice Following Maternal Exposure to Nanosized Titanium Dioxide

Exposure to nanosized titanium oxide (nano-TiO₂) has been proven to suppress brain growth in mouse offspring; however, whether retardation of axonal or dendritic outgrowth is associated with activation of the mitogen-activated protein kinase (MAPK) pathway remains unclear. In the present study, pregnant mice were exposed to nano-TiO₂ at 1.25, 2.5, and 5 mg/kg body weight, and the molecular mechanism of axonal or dendritic outgrowth retardation was investigated. The results suggested that nano-TiO₂ crossed the blood-fetal barrier and blood-brain barrier and deposited in the brain of offspring, which retarded axonal and dendritic outgrowth, including the absence of axonal outgrowth, and decreased dendritic filament length, dendritic branching number, and dendritic spine density. Importantly, maternal exposure to nano-TiO₂ increased phosphorylated (p)-extracellular signal-regulated kinase1/2 (ERK1/2, +24.35% to +59.4%), p-p38 (+60.82% to 181.85%), and p-c-jun N-terminal kinase (JNK, +28.28% to 97.28%) expression in the hippocampus of the offspring. These findings suggested that retardation of axonal and dendritic outgrowth in mouse offspring caused by maternal exposure to nano-TiO₂ may be related to excessive activation of the ERK1/2/MAPK signaling pathway. Therefore, the potential toxicity of nano-TiO₂ is a concern, especially in pregnant woman or children who are exposed to nano-TiO₂.

Purple sweet potato color protects against high-fat diet-induced cognitive deficits through AMPK-mediated autophagy in mouse hippocampus

Prevention of obesity-induced cognitive decline is an important public health goal. Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, has beneficial potentials including antioxidant and neuroprotective activity. Evidence shows that anthocyanins can activate AMP-activated protein kinase (AMPK), a critical mediator of autophagy induction. This study investigated whether PSPC could improve cognitive function through regulating AMPK/autophagy signaling in HFD-fed obese mice. Our results showed that PSPC significantly ameliorated obesity, peripheral insulin resistance and memory impairment in HFD-fed mice. Moreover, enhanced autophagy was observed, along with the decreased levels of protein carbonyls, malondialdehyde and reactive oxygen species (ROS) in the hippocampus of HFD-fed mice due to PSPC administration. PSPC also promoted hippocampal brain-derived neurotrophic factor (BDNF) expression and neuron survival in HFD-fed mouse. These improvements were mediated, at least in part, by the activation of AMPK, which was confirmed by metformin treatment. It is concluded that PSPC has great potential to improve cognitive function in HFD-fed mice via AMPK activation that restores autophagy and protects against hippocampal apoptosis.

Nano-TiO2 Inhibits Development of the Central Nervous System and Its Mechanism in Offspring Mice

Nano titanium dioxide (Nano-TiO₂) has been applied in food packaging systems and food additives, but it may cause potential neurotoxicity for human and animals. In our study, the effects of nano-TiO₂ exposure during pregnancy/lactation on the development of the central nervous system in offspring mice were examined and its molecular mechanism involving Rho family was investigated. Our findings showed that pregnancy/lactation exposure to nano-TiO₂ resulted in thinning of cerebral and cerebellar cortex, decrease in number of neurons per unit area of cerebrum, edema and nuclear condensation, dysplasia of neurites in hippocampal pyramidal cells, thinning in pyramidal cell layer in hippocampus, and decrease in learning and memory of offspring mice. Furthermore, expressions of Rac1 and Cdc42 involved in axon and dendritic development were decreased, whereas RhoA expression and ratio of RhoA/Rac1 were increased in offspring brain. It implies that exposure to nano-TiO₂ during pregnancy/lactation could result in brain retardation and cognitive impairment in offspring mice, which was closely related to alterations in the expression of Rho protein family. Therefore, application of nano-TiO₂ in daily life should be performed with caution.

Pinopode score around the time of implantation is predictive of successful implantation following frozen embryo transfer in hormone replacement cycles

STUDY QUESTION

Is pinopode measurement of any prognostic value?

SUMMARY ANSWER

Pinopode expression was significantly associated with the occurrence of pregnancy after frozen embryo transfer.

WHAT IS KNOWN ALREADY

Pinopodes are expressed in the endometrium during the implantation period. Pinopode measurement has been proposed as a marker of endometrial receptivity.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was conducted at the Center of Reproductive Medicine, Sir Run Run Shaw Hospital, between 2014 and 2016, recruiting 172 women with infertility and undergoing frozen embryo transfer following IVF treatment. Among 172 participants, 46 women took part in the first study to quantify the daily changing pattern of pinopodes 3-7 days after the initiation of progesterone therapy in the hormone replacement cycles and the remaining 126 women with infertility participated in a study to examine the relationship between pinopode count and pregnancy outcome following frozen embryo transfer in hormone replacement cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The mean age of participants was 29 years old. All participants received an artificial hormone replacement protocol capable of supporting successful implantation. Endometrial biopsies from 46 women were obtained 3, 4, 5, 6 and 7 days after the initiation of progesterone therapy (P + 3, n = 6; P + 4, n = 6; P + 5, n = 11; P + 6, n = 13; P + 7, n = 10, respectively). Another 126 endometrial biopsies were obtained precisely 6 days after the initiation of progesterone. Scanning electron microscopy was used to capture the pinopode images, followed by use of the image J program to quantify the count and subtype of the pinopodes.

MAIN RESULTS AND THE ROLE OF CHANCE

We found that at least 60 microscopic fields were necessary to achieve a reproducible result. An intra-observer variability study showed good agreement between two measurements regarding the developing pinopode (DP) subtype (r = 0.95) and the fully developed pinopode (FDP) subtype (r = 0.86) but not for the regressing (RP) pinopode subtype (r = 0.39). The proportion of DP/total pinopodes (TP) declined rapidly form day P + 4 to a minimum on day P + 6. The percentage of FDP/TP increased rapidly from day P + 4 to reach a peak on day P + 6. On the other hand, the percentage of RP/TP reached a peak on day P + 7. Participants who conceived had a significantly (P = 0.011) higher percentage of FDP/TP on day P + 6 and significantly (P = 0.005) lower percentage of DP/TP on the same day compared with participants who did not become pregnant. Using a scoring system incorporating the percentages of DP and FDP, it was found that the pregnancy rate and the embryo implantation rate of women with a high pinopode score (82.3%; 63.0%) was significantly (P = 0.001; P = 0.046) higher than that of women with a low pinopode score (53.3%; 46.7%), respectively. There remains a possibility that the observations could have arisen due to chance.

LIMITATIONS, REASONS FOR CAUTION

This study examined pinopode count and subtype in the HRT cycles, and it is uncertain whether the same observations apply to in natural cycles.

WIDER IMPLICATIONS OF THE FNDINGS

Pinopodes have been questioned as a potential marker of endometrial receptivity for many years. Our results suggested that pinopode measurement may be of value in predicting pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the grants from the general project of medicine and health in Zhejiang Province of China (2015KYA142; 2018KY106), the Key Research and Development Program of Zhejiang Province (2017C03022) and the National Natural Science Foundation of China (81701514).The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. We have no competing interests to declare.

TRIAL REGISTRATION NUMBER

ISRCTN26300668.

Retracted: Pulmonary fibrosis of mice and its molecular mechanism following chronic inhaled exposure to TiO2 nanoparticles

Nanoparticulate titanium dioxide (nano-TiO2 ) has been widely used in industry, medicine and daily life. However, assessment of nano-TiO2 toxicity on health is an important occupational safety issue. Numerous studies have demonstrated that nano-TiO2 can induced sustained pulmonary inflammation, but whether chronic exposure to nano-TiO2 results in pulmonary fibrosis is unclear. In this study, therefore, nano-TiO2 was administered to the male mice by nasal administration for six consecutive months, the inflammatory and/or fibrogenic responses induced by nano-TiO2 were investigated. The results showed that chronic inhaled nano-TiO2 induced pulmonary inflammation and firosis, increased expression of inflammatory cytokines and fibrotic cytokines including nuclear factor-κB, interleukin-1β, tumor necrosis factor-α, monocyte chemotactic protein 1, macrophage inflammatory protein-2, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, transform growth factor -β1, osteopontin, matrix metalloproteinase-1, -2, -3, and -9, tissue inhibitors of metalloproteinase-1, collagen, platelet derived growth factor, and connective tissue growth factor in mouse lung. Taken together, nano-TiO2 -induced pulmonary inflammation and fibrosis are closely associated with increased expression of inflammatory and/or fibrotic cytokines, an imbalanced production of MMPs and TIMP-1 that favors fibrosis in mice, implying that nano-TiO2 may lead to potential health effects.

Suppression of testosterone production by nanoparticulate TiO2 is associated with ERK1/2-PKA-PKC signaling pathways in rat primary cultured Leydig cells

Background

Nanoparticulate titanium dioxide (nano-TiO₂) enters the body through various routes and causes organ damage. Exposure to nano-TiO₂ is reported to cause testicular injury in mice or rats and decrease testosterone synthesis, sperm number, and motility. Importantly, nano-TiO₂ suppresses testosterone production by Leydig cells (LCs) and impairs the reproductive capacity of animals.

Methods

In an attempt to establish the molecular mechanisms underlying the inhibitory effect of nano-TiO₂ on testosterone synthesis, primary cultured rat LCs were exposed to varying concentrations of nano-TiO₂ (0, 10, 20, and 40 µg/mL) for 24 hours, and alterations in cell viability, cell injury, testosterone production, testosterone-related factors (StAR, 3βHSD, P450scc, SR-BI, and DAX1), and signaling molecules (ERK1/2, PKA, and PKC) were investigated.

Results

The data show that nano-TiO₂ crosses the membrane into the cytoplasm or nucleus, triggering cellular vacuolization and nuclear condensation. LC viability decreased in a time-dependent manner at the same nano-TiO₂ concentration, nano-TiO₂ treatment (10, 20, and 40 µg/mL) decreased MMP (36.13%, 45.26%, and 79.63%), testosterone levels (11.40% and 44.93%), StAR (14.7%, 44.11%, and 72.05%), 3βHSD (26.56%, 50%, and 79.69%), pERK1/2 (27.83%, 63.61%, and 78.89%), PKA (47.26%, 70.54%, and 85.61%), PKC (30%, 50%, and 71%), SR-BI (16.41%, 41.79%, and 67.16%), and P450scc (39.41%, 55.26%, and 86.84%), and upregulated DAX1 (1.31-, 1.63-, and 3.18-fold) in primary cultured rat LCs.

Conclusion

Our collective findings indicated that nano-TiO₂-mediated suppression of testosterone in LCs was associated with regulation of ERK1/2–PKA–PKC signaling pathways.

[Spatial-temporal analysis on pulmonary tuberculosis in Beijing during 2005-2015]

Objective: To analyze the spatial distribution and identify the high risk areas of pulmonary tuberculosis at the township level in Beijing during 2005-2015. Methods: Data on pulmonary tuberculosis cases was collected from the tuberculosis information management system. Global autocorrelation analysis, local indicators of spatial association and Kulldorff's Scan Statistics were applied to map the spatial distribution and detect the space-time clusters of the pulmonary tuberculosis cases during 2005-2015. Results: Spatial analysis on the incidence of pulmonary tuberculosis at the township level demonstrated that the spatial autocorrelation was positive during the study period. The values of Moran's I ranged from 0.224 3 to 0.291 8 with all the P values less than 0.05. Hotspots were primarily distributed in 8 towns/streets as follows: Junzhuang, Wangping, Yongding and Tanzhesi in Mentougou district, Yancun in Fangshan district, Wangzuo town in Fengtai district, Tianqiao street in Xicheng district and Tianzhu town in Shunyi district. Spatiotemporal clusters across the entire study period were identified by using Kulldorff's spatiotemporal scan statistic. The primary cluster was located in Chaoyang and Shunyi districts, including 17 towns/streets, as follows: Cuigezhuang, Maizidian, Dongfeng, Taiyanggong, Zuojiazhuang, Hepingjie, Xiaoguan, Xiangheyuan, Dongba, Jiangtai, Wangjing, Jinzhan, Jiuxianqiao, Laiguangying, Sunhe towns/streets in Chaoyang district, Houshayu and Tianzhu town in Shunyi district, during January to December 2005. Conclusion: Incidence rates of pulmonary tuberculosis displayed spatial and temporal clusterings at the township level in Beijing during 2005-2015, with high risk areas relatively concentrated in the central and southern parts of Beijing.

Nanosized titanium dioxide-induced premature ovarian failure is associated with abnormalities in serum parameters in female mice

Background

Exposure to titanium dioxide nanoparticles (TiO₂ NPs) that are widely used in food, medicine, sunscreen products and cosmetics is reported to cause ovarian damage and lower fertility in animals. However, the potential effects of TiO₂ NPs application on premature ovarian failure (POF) have rarely been evaluated to date.

Methods

In this study, female mice were continuously exposed to TiO₂ NPs at doses of 2.5, 5 or 10 mg/kg via gavage instillation for 30 days, and investigated the serum hormones and autoimmunity markers associated with POF.

Results

Exposure to TiO₂ NPs resulted in POF, reductions in the levels of estradiol, progesterone and inhibin B and increases in luteinizing hormone, follicle-stimulating hormone, follicle-stimulating hormone/luteinizing hormone ratio, anti-Müllerian hormone, thyroid-stimulating hormone, free triiodothyronine, free tetraiodothyronine, anti-nuclear antibody and anti-thyroid peroxidase antibody levels in serum.

Conclusion

Exposure to TiO₂ NPs induced POF triggered by alterations in hormones and autoimmunity markers. Our findings highlight the necessity for significant caution in handling and usage of TiO₂ NPs by female consumers.

Nanoparticulate titanium dioxide-inhibited dendritic development is involved in apoptosis and autophagy of hippocampal neurons in offspring mice

Background: Numerous studies have demonstrated that, upon maternal exposure, nano-TiO2 can cross the placental barrier, accumulate in offspring animals, and cause neurotoxicity. However, the neurotoxic mechanisms are not fully understood. The aim of this study is to determine the effects of nano-TiO2 on the dendritic outgrowth of hippocampal neurons and confirm the role of apoptosis and excessive autophagy in the neurotoxicity of offspring mice caused by nano-TiO2, as well as its molecular mechanisms. Methods: Pregnant mice were intragastrically administered 1, 2, or 3 mg per kg body weight nano-TiO2 consecutively from prenatal day 7 to postpartum day 21. The ultrastructure, mitochondrial membrane potential (MMP), levels of reactive oxygen species (ROS) and peroxides, and ATP contents, along with the expression of apoptosis- and autophagy-related factors, were investigated. Results: The dendritic length of hippocampal neurons was lower in the group treated with nano-TiO2 than in the control group. Apoptosis, excessive autophagy, and nano-TiO2 aggregation in hippocampal neurons resulted from maternal exposure to nano-TiO2. Maternal exposure to nano-TiO2 also resulted in the over-production of ROS, increases in malondialdehyde and protein carbonylation, reductions in MMP and ATP contents, up-regulation of apoptosis- or autophagy-related factors including histone H2AX at serine 139 (γH2AX), cytochrome C (Cyt C), caspase 3, phosphoinositide 3-kinase (PI3K3C), Beclin 1, c-Jun, LC3I, LC3II, JNK and p-JNK expression, and an increase of LC3II/LC3I, as well as down-regulation of Bcl-2 expression in hippocampal neurons of offspring mice. Conclusions: Maternal exposure to nano-TiO2 inhibited the dendritic outgrowth of hippocampal neurons. This effect is closely associated with excessive autophagy, which is related to severe oxidative stress and alterations in the expressions of apoptosis- and autophagy-related factors in the hippocampal neurons of offspring mice, due to maternal exposure to nano-TiO2.

Cerium Improves Growth of Maize Seedlings via Alleviating Morphological Structure and Oxidative Damages of Leaf under Different Stresses

It had been indicated that cerium (Ce) could promote maize growth involving photosynthetic improvement under potassium (K) deficiency, salt stress, and combined stress of K⁺ deficiency and salt stress. However, whether the improved growth is related to leaf morphological structure, oxidative stress in maize leaves is not well understood. The present study showed that K⁺ deficiency, salt stress, and their combined stress inhibited growth of maize seedlings, affecting the formation of appendages of leaf epidermal cells, and stomatal opening, which may be due to increases in H₂O₂ and malondialdehyde levels, and reductions in Ca²⁺ content, ratios of glutathione/oxidized glutathione, ascorbic acid/dehydroascorbic acid, and the activities of superoxide dismutase, catalase, ascorbic acid peroxidase, guaiacol peroxidase, and glutathione reductase in leaves under different stresses. The adverse effects caused by combined stress were higher than those of single stress. Furthermore, our findings demonstrated that adding Ce³⁺ could significantly promote seedling growth, and alleviate morphological and structural damage of leaf, decrease oxidative stress and increase antioxidative capacity in maize leaves caused by different stresses.

Maternal exposure to nanosized titanium dioxide suppresses embryonic development in mice

Although nanoscale titanium dioxide (nano-TiO2) has been extensively used in industrial food applications and daily products for pregnant women, infants, and children, its potential toxicity on fetal development has been rarely studied. The main objective of this investigation was to establish the effects of maternal exposure of nano-TiO2 on developing embryos. Female imprinting control region mice were orally administered nano-TiO2 from gestational day 0 to 17. Our findings showed that Ti concentrations in maternal serum, placenta, and fetus were increased in nano-TiO2-exposed mice when compared to controls, which resulted in reductions in the contents of calcium and zinc in maternal serum, placenta, and fetus, maternal weight gain, placental weight, fetal weight, number of live fetuses, and fetal crown-rump length as well as cauda length, and caused an increase in the number of both dead fetuses and resorptions. Furthermore, maternal nano-TiO2 exposure inhibited development of the fetal skeleton, suggesting a significant absence of cartilage, reduced or absent ossification, and an increase in the number of fetuses with dysplasia, including exencephaly, spina bifida, coiled tail, scoliosis, rib absence, and sternum absence. These findings indicated that nano-TiO2 can cross the blood-fetal barrier and placental barrier, thereby delaying the development of fetal mice and inducing skeletal malformation. These factors may be associated with reductions in both calcium and zinc in maternal serum and the fetus, and both the placenta and embryos may be major targets of developmental toxicity following maternal exposure to nano-TiO2 during the prenatal period. Therefore, the application of nano-TiO2 should be carried out with caution.

Chronic nasal exposure to nanoparticulate TiO2 causes pulmonary tumorigenesis in male mice

Chronic inhalation bioassays in rodents are used to assess pulmonary carcinogenicity for purposes of hazard identification and potentially for risk characterization. Numerous studies have been confirmed that exposure to titanium dioxide nanoparticles (TiO₂ NPs) may result in chronic pulmonary inflammation in both mice and rats. However, very few studies have focused on the pulmonary tumorigenesis. In this study, to examine whether chronic TiO₂ NP exposure induce tumorigenesis in the lung, forty mice (each group) were nasally exposed to 1.25, 2.5, and 5 mg/kg body weight TiO₂ NPs for nine consecutive months, lung pathology was then evaluated, and the biochemical function parameters in bronchoalveolar lavage (BAL) and tumor markers in the serum were investigated using an ELISA method. We observed that nasal exposure to TiO₂ NPs caused infiltration of inflammatory cells, tumorigenesis in the lung, and accompanied by significant increases of lactate dehydrogenase, alkaline phosphatase, and total protein levels in BLAF, significant increases in tumor markers including cytokeratin 19, neuron-specific enolase, carcinoembryonic antigen, squamous cell carcinoma antigen, and cancer antigen-125 in the serum. It implies that chronic inhaled TiO₂ NPs may increase possibility of pulmonary tumor formation for human. Therefore, the production and application of TiO₂ NPs should be paid more attention. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1651-1657, 2017.

Dopamine enhances duodenal epithelial permeability via the dopamine D5 receptor in rodent

AIM

The intestinal barrier is made up of epithelial cells and intercellular junctional complexes to regulate epithelial ion transport and permeability. Dopamine (DA) is able to promote duodenal epithelial ion transport through D1-like receptors, which includes subtypes of D₁ (D₁ R) and D₅ (D₅ R), but whether D1-like receptors influence the duodenal permeability is unclear.

METHODS

FITC-dextran permeability, short-circuit current (I_SC ), Western blot, immunohistochemistry and ELISA were used in human D₅ R transgenic mice and hyperendogenous enteric DA (HEnD) rats in this study.

RESULTS

Dopamine induced a downward deflection in I_SC and an increase in FITC-dextran permeability of control rat duodenum, which were inhibited by the D1-like receptor antagonist, SCH-23390. However, DA decreased duodenal transepithelial resistance (TER), an effect also reversed by SCH-23390. A strong immunofluorescence signal for D₅ R, but not D₁ R, was observed in the duodenum of control rat. In human D₅ R knock-in transgenic mice, duodenal mucosa displayed an increased basal I_SC with high FITC-dextran permeability and decreased TER with a lowered expression of tight junction proteins, suggesting attenuated duodenal barrier function in these transgenic mice. D₅ R knock-down transgenic mice manifested a decreased basal I_SC with lowered FITC-dextran permeability. Moreover, an increased FITC-dextran permeability combined with decreased TER and tight junction protein expression in duodenal mucosa were also observed in HEnD rats.

CONCLUSION

This study demonstrates, for the first time, that DA enhances duodenal permeability of control rat via D₅ R, which provides new experimental and theoretical evidence for the influence of DA on duodenal epithelial barrier function.

Nanoparticulate TiO2 -mediated inhibition of the Wnt signaling pathway causes dendritic development disorder in cultured rat hippocampal neurons

Titanium dioxide nanoparticles (TiO₂ NPs) are increasingly used in daily life, in industry, and in environmental clearing, but their potential neurodevelopmental toxicity has been highly debated. In this study, we explored whether TiO₂ NPs inhibited development of dendritic morphology and identified possible molecular mechanisms associated with this inhibition in primary cultured rat hippocampal neurons. Results showed that TiO₂ NPs decreased neurite length, the number of branches and the spine density, and impaired mitochondrial function in the developing neurons. Furthermore, TiO₂ NPs significantly reduced the expression of several proteins involved in canonical Wnt3a/β-catenin signaling including Wnt3a, β-catenin, p-GSK-3β, and CyclinD1 and conversely, elevated GSK-3β expression. In addition to altering expression of proteins involved in canonical Wnt3a/β-catenin signaling, TiO₂ NPs decreased expression of proteins invovled in non-canonical Wnt signaling, including, MKLP1, CRMP3, ErbB4, and KIF17. Taken together, these results indicate that suppression of dendritic development caused by TiO₂ NPs is associated with inhibition of activation of the Wnt/β-catenin pathway or non-canonical Wnt pathway-induced expression of microtubule cytoskeletal components in the developing neurons. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2139-2149, 2017.

Progress of in vivo studies on the systemic toxicities induced by titanium dioxide nanoparticles

Titanium dioxide nanoparticles (TiO2 NPs) are inorganic materials with a diameter of 1-100 nm. In recent years, TiO2 NPs have been used in a wide range of products, including food, toothpaste, cosmetics, medicine, paints and printing materials, due to their unique properties (high stability, anti-corrosion, and efficient photocatalysis). Following exposure via various routes including inhalation, injection, dermal deposition and gastrointestinal tract absorption, NPs can be found in various organs in the body potentially inducing toxic effects. Thus more attention to the safety of TiO2 NPs is necessary. Therefore, the present review aims to provide a comprehensive evaluation of the toxic effects induced by TiO2 NPs in the lung, liver, stomach, intestine, kidney, spleen, brain, hippocampus, heart, blood vessels, ovary and testis of mice and rats in in vivo experiments, and evaluate their potential toxic mechanisms. The findings will provide an important reference for human risk evaluation and management following TiO2 NP exposure.

Toxic effects of TiO2 nanoparticles in primary cultured rat sertoli cells are mediated via a dysregulated Ca2+ /PKC/p38 MAPK/NF-κB cascade

Although numerous studies have demonstrated that titanium dioxide nanoparticles (TiO₂ NPs) can be accumulated in various animal organs and can cause toxicity, there is currently only limited data regarding reproductive toxicity especially on the toxic mechanisms of TiO₂ NPs in Sertoli cells. In order to investigate the mechanism of reproductive toxicity, primary cultured rat Sertoli cells were exposed to 5, 15, or 30 μg/mL TiO₂ NPs for 24 h, and TiO₂ NPs internalization, expression of PKC (p-PKC) and p38 MAPK (p-p38 MAPK) as well as calcium homeostasis were examined. Our findings demonstrated that TiO₂ NPs crossed the membrane into the cytoplasm or nucleus, and significantly suppressed cell viability of primary cultured rat Sertoli cells in a concentration-dependent manner. Furthermore, immunological dysfunction caused by TiO₂ NPs was involved in the increased expression of NF-κB, TNF-α, and IL-1β, and decreased IκB expression. TiO₂ NPs significantly decreased Ca²⁺ -ATPase and Ca²⁺ /Mg²⁺ -ATPase activity and enhanced intracellular Ca²⁺ levels, and up-regulated the expression of p-PKC and p-p38 MAPK in a dose-dependent manner in primary cultured rat Sertoli cells. Taken together, these findings indicate that TiO₂ NPs may induce immunological dysfunction of primary cultured rat Sertoli cells by stimulating the Ca²⁺ /PKC/p38 MAPK cascade, which triggers NF-κB activation and ultimately induces the expression of inflammatory cytokines in primary cultured rat Sertoli cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1374-1382, 2017.

[Analysis of newborn screening for galactosemia and genotype-phenotype of confirmed galatosemia cases]

Objective: To investigate the prevalence of galactosemia(GAL), and the characteristics of genotype and phenotype of newborns who were confirmed with GAL in newborn screening in Zhejiang province. Method: The number of all live births, newborn screened infants and all clinical data of confirmed newborns with GAL from October 2013 to March 2015 were retrospectively analyzed by reviewing the data of Zhejiang Province screening center database. And the characteristics of genes and the clinical data of GAL cases who were confirmed by correlative gene test and enzyme activity measurement were analyzed. Result: The prevalence of GAL in Zhejiang province was 1/189 857. Among them, there was 1 case confirmed with GAL typeⅠ (prevalence, 1/759 428), with mutations of c. 904+ 1G>T and c. 687G>A, the enzyme activity of galactose-1-phosphate uridyltransferase (GALT) was 56.4% of controls. And there was 1 case of GAL typeⅡ(prevalence, 1/759 428), with mutations of c. 85G>T and c. 502G>A. There were 2 cases confirmed with GAL type Ⅲ(prevalence, 1/379 714), with mutations of c. 505C>T, c. 452G>A, c. 280G>A and c. 925G>A, the enzyme activity of UDP-galactose-4'-epimerase (GALE) were 42% and 38% of controls, respectively. All cases had different abnormal biochemical marks of liver function, and 1 case had combined hyperlactacidemia or hyperammonemia or increase of multiple kinds of amino acids, respectively. The newborn of GAL type Ⅱ had phacoscotasmus before treatment. All the cases were fed with lactose free milk powder, and all the abnormal parameters were improved during following up. Conclusion: The disease of GAL is rare in Zhejiang province, and its genotype distribution is scattered with comparatively mind clinical manifestations, and the cases with early treatment with lactose free milk powder have good prognosis. All cases needed to be treated and followed up for a life-long time. It is recommended that the high risk cases with GAL should be screened as soon as possible.

[Clinical, biochemical and gene mutation characteristics of short chain acyl-coenzyme A dehydrogenase deficiency by neonatal screening]

Objective: To investigate the incidence, clinical, biochemical and gene mutation characteristics of short chain acyl-coenzyme A dehydrogenase deficiency (SCADD). Method: From January, 2009 to October, 2015, a retrospective analysis of the urine organic acids and acyl-coenzyme A dehydrogenase (ACADS) gene mutation characteristics of patients diagnosed as SCADD by newborn screening using tandem mass spectrometry in Department of Genetics and Metabolism (Newborn screening Center of Zhejiang Province), Children's Hospital, Zhejiang University School of Medicine. Dietary guidance, life management and supplementation of L-carnitine were conducted, and growth and intelligence development were observed during follow-up among the SCADD patients. Result: A total of 1 430 024 neonates, seventeen cases were diagnosed with SCADD with an incidence of 1/84 117. All patients had no clinical symptoms, and intelligence and physical development were normal. Blood butylacyl-carnitine (C4) levels and the ratios increased, C4 0.713.14 μmol/L(reference value 0.03-0.48 μmol/L), C4/C2 0.07-0.23(reference value 0.01-0.04), C4/C3 0.65-2.04(reference value 0.05-0.39). Thirteen with increased urinary ethyl malonic acid (9.30-90.99 mg/g creatinine (reference value 0-6.20 mg/g creatinine )), one patient was accompanied by increased methyl succinic acid (12.33 mg/g creatinine(reference value 0-6.40 mg/g creatinine)), one subject with increased acetylglycine (3.52 mg/g creatinine(reference value 0-0.70 mg/g creatinine)). A total of 13 known mutations were detected in the ACADS gene, 1 homozygous mutation (c.1031A>G), the others are compound heterozygous mutations. One frameshift mutation (c.508_509delGC) and 12 missense mutations were detected. Common mutation were c. 1031A>G(35.3%), c. 164C>T(20.6%) and c. 991G>A(11.8%). SCADD in newborn screening program had no clinical symptoms and normal growth development after 8-42 months follow-up. Conclusion: Cases with SCADD had no clinical symptoms with an incidence of 1/84117. The c. 164C>T and c. 1031A>G may be the common mutations.