Association and mediation analyses among multiple metals exposure, plasma folate, and community-based impaired estimated glomerular filtration rate in central Taiwan.

BACKGROUND: Chronic kidney disease (CKD) is increasing, with heavy metal exposure an important risk factor. Additionally, the antioxidant folic acid has been studied for reducing blood arsenic levels and related tissue damage. Therefore, we explored the association and mediation effects among various heavy metal levels in blood, plasma folate, other CKD risk factors, and impaired estimated glomerular filtration rate (eGFR). METHODS: We constructed a community-based cross-sectional study from the Human Biomonitoring and Environmental Health Program in central Taiwan. A total of 1643 participants had lived locally for > 5 years, > 40 years old, and completely received health examinations and biospecimen collections. Impaired eGFR was defined as one single eGFR < 60 mL/min/1.73 m2. Plasma folate and metal levels in blood were determined, as well as urinary 8-hydroxy-2'-deoxyguanosine as an oxidative stress marker. Generalized weighted quantile sum (WQS) regression analysis was used to calculate a WQS score, reflecting overall body-burden of multiple metals (arsenic, cadmium, chromium, nickel, and lead) in blood. RESULTS: Impaired eGFR was identified in 225 participants. Participants with high WQS scores had increased risk of impaired eGFR (odds ratio = 1.67; 95% confidence interval [CI]: 1.34, 2.07). Of five metals, arsenic, lead, and cadmium were weighted highly in impaired eGFR. Participants with high WQS and folate insufficiency (< 6 ng/mL) had 2.38-fold risk of impaired eGFR compared to those with low WQS and high folate (≥6 ng/mL) (95% CI: 1.55, 5.17). Similar increased 4.16-fold risk of impaired eGFR was shown in participants with high WQS and uric acid levels (95% CI: 2.63, 6.58). However, there were no significant WQS-folate (p = 0.87) or WQS-uric acid (p = 0.38) interactions on impaired eGFR risk. As a mediator, uric acid contributed 24% of the association between WQS score and impaired eGFR risk (p < 0.0001). However, no mediation effect of plasma folate was observed. CONCLUSION: WQS analysis could be applied to evaluate the joint effects of multiple metals exposure. High WQS scores may influence impaired eGFR risk through increased uric acid levels. A large-scale and prospective cohort study is necessary to validate these results and demonstrate any causal relationship.

Quercetin induces tongue squamous cell carcinoma cell apoptosis via the JNK activation-regulated ERK/GSK-3α/ß-mediated mitochondria-dependent apoptotic signaling pathway.

Tongue squamous cell carcinoma (SCC) is a most common type of oral cancer. Due to its highly invasive nature and poor survival rate, the development of effective pharmacological therapeutic agents is urgently required. Quercetin (3,3',4',5,7-pentahydroxyflavone) is a polyphenolic flavonoid found in plants and is an active component of Chinese herbal medicine. The present study investigated the pharmacological effects and possible mechanisms of quercetin on apoptosis of the tongue SCC-derived SAS cell line. Following treatment with quercetin, cell viability was assessed via the MTT assay. Apoptotic and necrotic cells, mitochondrial transmembrane potential and caspase-3/7 activity were analyzed via flow cytometric analyses. A caspase-3 activity assay kit was used to detect the expression of caspase-3 activity. Western blot analysis was performed to examine the expression levels of proteins associated with the MAPKs, AMPKα, GSK3-α/ß and caspase-related signaling pathways. The results revealed that quercetin induced morphological alterations and decreased the viability of SAS cells. Quercetin also increased apoptosis-related Annexin V-FITC fluorescence and caspase-3 activity, and induced mitochondria-dependent apoptotic signals, including a decrease in mitochondrial transmembrane potential and Bcl-2 protein expression, and an increase in cytosolic cytochrome c, Bax, Bak, cleaved caspase-3, cleaved caspase-7 and cleaved poly (ADP-ribose) polymerase protein expression. Furthermore, quercetin significantly increased the protein expression levels of phosphorylated (p)-ERK, p-JNK1/2 and p-GSK3-α/ß, but not p-p38 or p-AMPKα in SAS cells. Pretreatment with the pharmacological JNK inhibitor SP600125 effectively reduced the quercetin-induced apoptosis-related signals, as well as p-ERK1/2 and p-GSK3-α/ß protein expression. Both ERK1/2 and GSK3-α/ß inhibitors, PD98059 and LiCl, respectively, could significantly prevent the quercetin-induced phosphorylation of ERK1/2 and GSK3-α/ß, but not JNK activation. Taken together, these results suggested that quercetin may induce tongue SCC cell apoptosis via the JNK-activation-regulated ERK1/2 and GSK3-α/ß-mediated mitochondria-dependent apoptotic signaling pathway.

Development of MRI-Detectable Boron-Containing Gold Nanoparticle-Encapsulated Biodegradable Polymeric Matrix for Boron Neutron Capture Therapy (BNCT).

This study aimed to develop a novel magnetic resonance imaging (MRI)-detectable boron (B)-containing nanoassemblies and evaluate their potential for boron neutron capture therapy (BNCT). Starting from the citrate-coated gold nanoparticles (AuNPs) (23.9 ± 10.2 nm), the diameter of poly (D, L-lactide-co-glycolide) AuNPs (PLGA-AuNPs) increased approximately 110 nm after the encapsulation of the PLGA polymer. Among various B drugs, the self-produced B cages had the highest loading efficiency. The average diameter of gadolinium (Gd)- and B-loaded NPs (PLGA-Gd/B-AuNPs) was 160.6 ± 50.6 nm with a B encapsulation efficiency of 28.7 ± 2.3%. In vitro MR images showed that the signal intensity of PLGA-Gd/B-AuNPs in T1-weighted images was proportional to its Gd concentration, and there exists a significantly positive relationship between Gd and B concentrations (R2 = 0.74, p < 0.005). The hyperintensity of either 250 ± 50 mm3 (larger) or 100 ± 50 mm3 (smaller) N87 xenograft was clearly visualized at 1 h after intravenous injection of PLGA-Gd/B-AuNPs. However, PLGA-Gd/B-AuNPs stayed at the periphery of the larger xenograft while located near the center of the smaller one. The tumor-to-muscle ratios of B content, determined by inductively coupled plasma mass spectrometry, in smaller- and larger-sized tumors were 4.17 ± 1.42 and 1.99 ± 0.55, respectively. In summary, we successfully developed theranostic B- and Gd-containing AuNPs for BNCT in this study.

Arsenic induces autophagy-dependent apoptosis via Akt inactivation and AMPK activation signaling pathways leading to neuronal cell death.

Inorganic arsenic (As3+), a well-known worldwide industrial and environmental pollutant, has been linked to neurodegenerative disorders (NDs). Autophagy plays an important role in controlling neuronal cell survival/death. However, limited information is available regarding the toxicological mechanism at the interplay between autophagy and As3+-induced neurotoxicity. The present study found that As3+ exposure induced a concomitant activation of apoptosis and autophagy in Neuro-2a cells, which was accompanied with the increase of phosphatidylserine exposure on outer membrane leaflets and apoptotic cell population, and the activation of caspase-3, -7, and PARP as well as the elevation of protein expressions of LC3-II, Atg-5, and Beclin-1, and the accumulation of autophagosome. Pretreatment of cells with autophagy inhibitor 3-MA, but not that of Z-VAD-FMK (a pan-caspase inhibitor), effectively prevented the As3+-induced autophagic and apoptotic responses, indicating that As3+-triggered autophagy was contributing to neuronal cell apoptosis. Furthermore, As3+ exposure evoked the dephosphorylation of Akt. Pretreatment with SC79, an Akt activator, could significantly attenuated As3+-induced Akt inactivation as well as autophagic and apoptotic events. Expectedly, inhibition of Akt signaling with LY294002 obviously enhanced As3+-triggered autophagy and apoptosis. Exposure to As3+ also dramatically increased the phosphorylation level of AMPKα. Pretreatment of AMPK inhibitor (Compound C) could markedly abrogate the As3+-induced phosphorylated AMPKα expression, and autophagy and apoptosis activation. Taken together, these results indicated that As3+ exerted its cytotoxicity in neuronal cells via the Akt inactivation/AMPK activation downstream-regulated autophagy-dependent apoptosis pathways, which ultimately lead to cell death. Our findings suggest that the regulation of Akt/AMPK signals may be a promising intervention to against As3+-induced neurotoxicity and NDs.

Adherence to Nutritional Supplementation Determines Postoperative Vitamin D Status, but Not Levels of Bone Resorption Marker, in Sleeve-Gastrectomy Patients.

BACKGROUND: Taking advantage of isomeric form of vitamin E in the supplement, adherence to supplement could be evaluated by changes in circulating α- and γ-tocopherol concentrations. Accordingly, effects of supplementation on postoperative nutrition and bone metabolism were studied in terms of adherence. METHODS: Thirty-eight SG patients were all prescribed a postoperative nutritional supplement containing a low dose of vitamin D (600 IU) and calcium (200 mg). Blood samples were collected prior to (M0) and 6 months after (M6) surgery and concentrations of nutrients and C-terminal telopeptide of type I collage (CTX), a marker of bone resorption, were measured. Adherence and non-adherence were stratified according to change (△, M6-M0) in serum α-tocopherol concentrations (> 0 vs. ≤ 0, respectively). RESULTS: When M0 and M6 were compared, there were significant increases in serum concentrations of 25(OH)D, α-tocopherol and selenium, whereas there were reductions in parathyroid hormone, ferritin, and γ-tocopherol. At M6, the prevalence of vitamin D insufficiency (25(OH)D < 30 ng/mL) and high CTX were 72 and 26%, respectively. When comparison was made between adherence and non-adherence, only △25(OH)D concentrations, but no other nutrients nor postoperative CTX differed. Multiple linear regression demonstrated that postoperative vitamin D status was independently associated with its preoperative concentrations (ß = 0.85, p < 0.001) and adherence (ß = 0.52, p < 0.05). CONCLUSION: SG patients' adherence to supplementation, even with a low dose of vitamin D and calcium, determined vitamin D status but not bone resorption marker concentrations, at least within 6 months after surgery.

Roles of ERK/Akt signals in mitochondria-dependent and endoplasmic reticulum stress-triggered neuronal cell apoptosis induced by 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene, a major active metabolite of bisphenol A.

Bisphenol A (BPA) is recognized as a harmful pollutant in the worldwide. Growing studies have reported that BPA can cause adverse effects and diseases in human, and link to a potential risk factor for development of neurodegenerative diseases (NDs). 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), which generated in the mammalian liver after BPA exposure, is a major active metabolite of BPA. MBP has been suggested to exert greater toxicity than BPA. However, the molecular mechanism of MBP on the neuronal cytotoxicity remains unclear. In this study, MBP exposure significantly reduced Neuro-2a cell viability and induced apoptotic events that MBP (5-15 µM) exhibited greater neuronal cytotoxicity than BPA (50-100 µM). The mitochondria-dependent apoptotic signals including the decrease in mitochondrial membrane potential (MMP) and the increase in cytosolic apoptosis-induced factor (AIF), cytochrome c release, and Bax protein expression were involved in MBP (10 µM)-induced Neuro-2a cell death. Exposure of Neuro-2a cells to MBP (10 µM) also triggered endoplasmic reticulum (ER) stress through the induction of several key molecules including glucose-regulated protein (GRP)78, C/EBP homologous protein (CHOP), X-box binding protein (XBP)-1, protein kinase R-like ER kinase (PERK), eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme(IRE)-1, activation transcription factor(AFT)4 and ATF6, and caspase-12. Pretreatment with 4-PBA (an ER stress inhibitor) and specific siRNAs for GRP78, CHOP, and XBP-1 significantly suppressed the expression of these ER stress-related proteins and the activation of caspase-12/-3/-7 in MBP-exposed Neuro-2a cells. Furthermore, MBP (10 µM) exposure dramatically increased the activation of extracellular regulated protein (ERK)1/2 and decreased Akt phosphorylation. Pretreatment with PD98059 (an ERK1/2 inhibitor) and transfection with the overexpression of activation of Akt1 (myr-Akt1) effectively suppressed MBP-induced apoptotic and ER stress-related signals. Collectively, these results demonstrate that MBP exposure exerts neuronal cytotoxicity via the interplay of ERK activation and Akt inactivation-regulated mitochondria-dependent and ER stress-triggered apoptotic pathway, which ultimately leads to neuronal cell death.

Lead poisoning due to incense burning: an outbreak in a family.

BACKGROUND: In Asia and some other regions of the world, incense burning is an important folk and cultural activity. However, this ritual can cause health impacts, such as chronic respiratory diseases and neoplasms. Herein, we describe a family with lead poisoning possibly related to the frequent use of incense sticks at home. CASE REPORT: A 65-year-old homemaker with severe anemia, pitting edema of the lower legs, bone pain, abdominal pain, and exertional dyspnea for several months presented to our clinic. Her blood workup indicated severe anemia with basophilic stippling in red blood cells and blood lead level (BLL) of 59.75 µg/dL. Her husband, three children, and four grandchildren who lived with her also had high BLLs. As a Daoist clergy person, she had been exposed to a large amount of smoke from every day use of incense for >30 years. In the field investigation, the chronic dust deposited in hidden corners of their home had considerably higher lead content and other toxic metals. DISCUSSION: Our observations indicated chronic, frequent exposure to smoke from incense burning may be a cause of lead poisoning. Strict avoidance of incense smoke is a significant step toward preventing lead poisoning in children in societies with the custom of incense burning.

Nutritional Status of Obese Taiwanese Before Bariatric-Metabolic Surgery and Their Serum 25-Hydroxyvitamin D Concentrations for Maximal Suppression of Parathyroid Hormone.

BACKGROUND: This is the first report from Taiwan using laboratory tests to assess nutritional status of patients with obesity before bariatric-metabolic surgery. Moreover, the 25(OH)D threshold for maximal suppression of parathyroid hormone (PTH) was evaluated to offer a reference value for preoperative nutritional care. METHODS: Inclusion criteria were Taiwanese, 18-65 years old, and with BMI ≥ 27.5 kg/m2 awaiting bariatric-metabolic surgery. Anthropometric data and blood samples were collected before surgery. Serum concentrations of protein; vitamins B1, B12, folate, A, D, and E; calcium; iron; zinc; copper; selenium; PTH; and erythrocyte glutathione reductase activity coefficient (vitamin B2 status) were measured. RESULTS: For 52 participants with a mean BMI 37.6 ± 6.4 kg/m2, vitamin D deficiency (25(OH)D < 20 ng/mL) and insufficiency (20 < 25(OH)D < 30 ng/mL) were at 73 and 22% prevalence, respectively. Secondary hyperparathyroidism (PTH â‰§ 65 pg/mL) was 24% and hypocalcemia was 50% (ionized Ca < 4.5 mg/dL). Deficiency of other nutrients was sporadic (< 10%) or nil. When participants were stratified according to 25(OH)D concentrations (< 10, 10-15, 15-20, and ≥ 20 ng/mL), PTH increased at 25(OH)D < 10 ng/mL (ß = 48.34, p = 0.001) after adjusting for age, gender, and BMI. CONCLUSION: For patients with obesity before bariatric-metabolic surgery, vitamin D/calcium deficiency was the only nutritional issue that needs to be addressed in Taiwan. However, a lower cutoff point of 25(OH)D, i.e., 10 ng/mL, for vitamin D deficiency may be considered for patients before surgery. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03915158.

Ultrafine silicon dioxide nanoparticles cause lung epithelial cells apoptosis via oxidative stress-activated PI3K/Akt-mediated mitochondria- and endoplasmic reticulum stress-dependent signaling pathways.

Silicon dioxide nanoparticles (SiO2NPs) are widely applied in industry, chemical, and cosmetics. SiO2NPs is known to induce pulmonary toxicity. In this study, we investigated the molecular mechanisms of SiO2NPs on pulmonary toxicity using a lung alveolar epithelial cell (L2) model. SiO2NPs, which primary particle size was 12 nm, caused the accumulation of intracellular Si, the decrease in cell viability, and the decrease in mRNAs expression of surfactant, including surfactant protein (SP)-A, SP-B, SP-C, and SP-D. SiO2NPs induced the L2 cell apoptosis. The increases in annexin V fluorescence, caspase-3 activity, and protein expression of cleaved-poly (ADP-ribose) polymerase (PARP), cleaved-caspase-9, and cleaved-caspase-7 were observed. The SiO2NPs induced caspase-3 activity was reversed by pretreatment of caspase-3 inhibitor Z-DEVD-FMK. SiO2NPs exposure increased reactive oxygen species (ROS) production, decreased mitochondrial transmembrane potential, and decreased protein and mRNA expression of Bcl-2 in L2 cells. SiO2NPs increased protein expression of cytosolic cytochrome c and Bax, and mRNAs expression of Bid, Bak, and Bax. SiO2NPs could induce the endoplasmic reticulum (ER) stress-related signals, including the increase in CHOP, XBP-1, and phospho-eIF2α protein expressions, and the decrease in pro-caspase-12 protein expression. SiO2NPs increased phosphoinositide 3-kinase (PI3K) activity and AKT phosphorylation. Both ROS inhibitor N-acetyl-l-cysteine (NAC) and PI3K inhibitor LY294002 reversed SiO2NPs-induced signals described above. However, the LY294002 could not inhibit SiO2NPs-induced ROS generation. These findings demonstrated first time that SiO2NPs induced L2 cell apoptosis through ROS-regulated PI3K/AKT signaling and its downstream mitochondria- and ER stress-dependent signaling pathways.

Ecosystem metabolism regulates seasonal bioaccumulation of metals in atyid shrimp (Neocaridina denticulata) in a tropical brackish wetland.

Natural dissolved organic matter (DOM) forms the base of aquatic food webs and is a key environmental factor that affects the bioavailability of metals for aquatic organisms. Aquatic communities are naturally exposed simultaneously to environments containing a mixture of metals and varying DOM levels and compositions. However, the exact effect of DOM on metal bioaccumulation is difficult to predict due to temporal and spatial variations in sources, production, and consumption of DOM, and to interactions between DOM and metals. Ecosystem metabolism describes the process of organic carbon production and consumption and, therefore, the trophic status of ecosystems. However, whether and how ecosystem metabolism determines the seasonality of metal bioaccumulation remains unclear. The present study used in-situ water quality sondes and discrete field samplings to establish the relationship between the seasonality of ecosystem metabolism; related environmental and limnological regulators; the metal speciation and concentration in bulk water and sediments; and their metal bioaccumulation. The target population consisted of atyid shrimp (Neocaridina denticulata) in a brackish constructed wetland in tropical Taiwan was sampled between August 2014 and November 2015. Metal bioaccumulation displayed distinct seasonal patterns that peaked in summer (Cu, Cd, Cr, Zn, Mn, and Se) or winter (Pb and Ni). The in situ production (gross primary production) and heterotrophic consumption (ecosystem respiration) of organic matter significantly decreased with increasing waterborne DOM levels in this heterotrophic wetland. Both dissolved free metals bioavailable for respiratory surfaces (As, Zn, Cu, and Cr) and insoluble metals available for dietary intake (Mn and Ni) decreased with increasing DOM, as well as with decreasing gross primary production and ecosystem respiration. Seasonal variations of metal bioaccumulation also paralleled the transition in wetland trophic status, which reflected the effect of potential qualitative changes in the wetland DOM pool. Bioaccumulation of most metals displayed strong correlations with gross primary production, ecosystem respiration, and wetland trophic status. Our findings demonstrated that ecosystem metabolism can play a key mediating role in the seasonality of metal bioaccumulation in atyid shrimp, as it links the variation and interaction between DOM level/source, the speciation/bioavailability, and the uptake efficiency for metals by aquatic organisms. This study contributes to the temporal-specific risk assessment of aquatic metal exposure in regional environmental settings. It also reveals ecosystem-specific spectra in the context of changes in climate and environment.

Effects of ambient PM2.5 and particle-bound metals on the healthy residents living near an electric arc furnace: A community- based study.

Fine particulate matter (PM2.5) emitted from electric arc furnaces (EAFs) poses health concerns. However, little research has been done on the impact of EAF on the health of community residents. This cross-sectional study conducted a PM2.5 exposure assessment and health examination of community residents living near an EAF. A total of 965 residents aged 40-90 years were recruited. The residents' exposure to PM2.5 was categorized according to the distance of their residence from the EAFs (<500, 500-1000, 1000-1500, 1500-2000, and > 2000 m). Average ambient PM2.5 concentrations were estimated using a hybrid kriging/land-use regression (LUR) model. In addition, we selected two air-sampling sites to monitor the 2-year levels of PM2.5 and particle-bound metals. A spot urine sample and blood samples were collected and ten heavy metal concentrations in the blood were analyzed. Inflammation- and oxidative stress-related biomarkers were measured. The associations between environmental factors and a biochemical examination were estimated using a generalized linear model. Active air sampling and hybrid kriging/LUR model simulation indicated increased levels of PM2.5 near the EAF. The metal concentrations in PM2.5 included Fe, Pb, Mn, Ni, As, Cu, Ni, Zn, and Al, which also significantly increased near the EAF. PM2.5 levels were significantly associated with an increased total cholesterol-high-density lipoprotein (TC/HDL) ratio. High levels of PM2.5 and malondialdehyde were associated with a 1.72-fold increased risk of TC/HDL ratio ≥ 4 (95% CI: 1.12-2.65) after adjusting for potential confounding factors. Blood Pb levels were significantly associated with increased systolic and diastolic blood pressure and decreased estimated glomerular filtration rate but negatively associated with distance from the EAF. The results show that people living near EAFs should pay more attention to adverse health problems, including atherogenic dyslipidemia, hypertension, and chronic kidney disease associated with exposure to PM2.5 and particle-bound metals.

Silica nanoparticles induce caspase-dependent apoptosis through reactive oxygen species-activated endoplasmic reticulum stress pathway in neuronal cells.

Human exposure to silica nanoparticles (SiNPs) has been widely applied as vehicles for drug delivery and cellular manipulations in nanoneuromedicine. SiNPs may cause adverse effects in the brain, but potential mechanisms underlying SiNPs-induced neurotoxicity are remained unclear. Here, we examined cytotoxic effects and the cellular mechanisms of SiNPs-induced neuronal cell death. In this study, the results showed that SiNPs significantly decreased cell viability and induced apoptosis in Neuro-2a cells as evidenced by the increase caspase-3 activity and the activation of caspase cascades and poly (ADP-ribose) polymerase (PARP). In addition, endoplasmic reticulum (ER) stress was triggered as indicated by several key molecules including glucose-regulated protein (GRP)78 and 94, C/EBP homologous protein (CHOP), activation transcription factor (ATF)-4, and caspase-12. Pretreatment of Neuro-2a cells with specific pharmacological inhibitor of ER stress (4-phenylbutyric acid (4-PBA)) effectively alleviated the SiNPs-induced ER stress and apoptotic related signals. Furthermore, 2',7'-Dichlorofluorescein fluorescence as an indicator of reactive oxygen species (ROS) formation after exposure of Neuro-2a cells to SiNPs significantly increased ROS levels. Antioxidant N-acetylcyseine (NAC) effectively reversed SiNPs-induced cellular responses. Taken together, these results suggest that SiNPs exposure exerts its neurotoxicity in cultured neuronal cells by inducing apoptosis via a ROS generation-activated downstream ER stress signaling pathway.

Development of theranostic active-targeting boron-containing gold nanoparticles for boron neutron capture therapy (BNCT).

Successful boron neutron capture therapy (BNCT) requires sufficient and specific delivery of boron atoms to malignant cells. Gold nanoparticles (AuNPs) have been used as a useful delivery system for selectively releasing cytotoxic payloads in the tumor. However, studies demonstrating the in vivo distribution or pharmacokinetics of boron-containing AuNPs via noninvasive imaging are lacking. This study aims to develop theranostic AuNP-boron cage assemblies (B-AuNPs) and evaluate its feasibility for BNCT. The commercial citrate-coated AuNPs were subjected to PEGylation, azide addition, and carborane modification on the surface. To further arm the AuNPs, we conjugated anti-HER2 antibody (61 IgG) with boron-containing PEGylated AuNPs to form 61-B-AuNPs. The diameter and radiolabeling efficiency of boron-containing AuNPs were determined by dynamic light scattering (DLS) and radio thin-layer chromatography (radio TLC), respectively. Noninvasive single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging was performed to determine the pharmacokinetics of radioiodinated AuNPs in N87 gastric cancer xenografts, and the content of boron in tumor and muscle was assessed by inductively coupled plasma mass spectrometry (ICP-MS). After the 3-step modification, the diameter of B-AuNPs increased by ˜25 nm, and antibody conjugation did not affect the diameter of AuNPs. Radioactive iodine (I-123) was introduced in AuNPs by Click chemistry under copper catalysis. The radiolabeling efficiency of 123I-B-AuNPs and 123I-61-B-AuNPs was approximately 60 ± 5%. After purification, the radiochemical purity (RCP) of these NPs was greater than 90%. MicroSPECT/CT imaging showed that the tumor-to-muscle (T/M) ratio of 123I-B-AuNP-injected mice reached 1.91 ± 0.17 at 12 h post-injection, while that of 123I-61-B-AuNP-injected mice was 12.02 ± 0.94. However, the increased uptake of AuNPs by the thyroid was observed at 36 h after the administration of 123I-61-B-AuNPs, indicating antibody-mediated phagocytosis. The T/M ratio, assessed by ICP-MS, of B-AuNP- and 61-B-AuNP-injected mice was 4.91 ± 2.75 and 41.05 ± 11.15, respectively. We successfully developed detectable HER2-targeting boron-containing AuNPs with high RCP and an acceptable yield. Noninvasive imaging could be a valuable tool for the noninvasive determination of the pharmacokinetics of AuNPs and measurement of boron concentration in the tumor.

Methylmercury exposure induces ROS/Akt inactivation-triggered endoplasmic reticulum stress-regulated neuronal cell apoptosis.

Epidemiological studies have positively linked mercury exposure and neurodegenerative diseases (ND). Methylmercury (MeHg), an organic form of mercury, is a ubiquitous and potent environmental neurotoxicant that easily crosses the blood-brain barrier and causes irreversible injury to the central nervous system (CNS). However, the molecular mechanisms underlying MeHg-induced neurotoxicity remain unclear. Here, the present study found that Neuro-2a cells underwent apoptosis in response to MeHg (1-5 µM), which was accompanied by increased phosphatidylserine (PS) exposure on the outer cellular membrane leaflets, caspase-3 activity, and the activation of caspase cascades and poly (ADP-ribose) polymerase (PARP). Exposure of Neuro-2a cells to MeHg also triggered endoplasmic reticulum (ER) stress, which was identified via several key molecules (including: glucose-regulated protein (GRP)78, GRP94, C/EBP homologous protein (CHOP) X-box binding protein(XBP)-1, protein kinase R-like ER kinase (PERK), eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme(IRE)-1, activation transcription factor(AFT)4, and ATF6. Transfection with GRP78-, GRP94-, CHOP-, and XBP-1-specific small interfering (si)RNA significantly suppressed the expression of these proteins, and attenuated cytotoxicity and caspase-12, -7, and -3 activation in MeHg-exposed cells. Furthermore, MeHg dramatically decreased Akt phosphorylation, and the overexpression of activation of Akt1 (myr-Akt1) could significantly prevent MeHg-induced Akt inactivation, as well as apoptotic and ER stress-related signals. Pretreatment with the antioxidant N-acetylcysteine (NAC) effectively prevented MeHg-induced neuronal cell reactive oxygen species (ROS) generation, apoptotic and ER stress-related signals, and Akt inactivation. Collectively, these results indicate that MeHg exerts its cytotoxicity in neurons by inducing ROS-mediated Akt inactivation up-regulated ER stress, which induces apoptosis and ultimately leads to cell death.

Cadmium exposure induces pancreatic ß-cell death via a Ca2+-triggered JNK/CHOP-related apoptotic signaling pathway.

Cadmium (Cd) is known to be ranked the 7th hazardous substance in the Substance Priority List by Agency for Toxic Substances and Disease Registry. The experimental and epidemiological data have suggested that Cd is linked to the development of diabetes mellitus (DM). The molecular mechanism of Cd on the pancreatic ß-cell cytotoxicity still remains unclear. Evidence has pointed toward that Ca2+ is an important regulator of toxic insult-induced ß-cell cytotoxicity. The role of Ca2+ in the Cd-induced ß-cell cytotoxicity is still unknown. In this study, we found that Cd exposure significantly inhibited insulin secretion and cell viability in the pancreatic ß-cell-derived RIN-m5F cells. Cd exposure induced apoptotic events, including the increased populations of apoptotic cells and sub-G1 hypodiploid cells, and caspase-3/-7/-9 and poly (ADP-ribose) polymerase (PARP) activation, which largely depended on the activation of c-Jun N-terminal kinase (JNK) and C/EBP homologous protein (CHOP). Transfection with siRNAs for JNK and CHOP or pretreatment with specific pharmacological inhibitor of JNK (SP600125) in ß-cells effectively prevented the Cd-induced insulin secretion dysfunction and apoptosis. JNK-specific siRNA dramatically suppressed Cd-induced JNK phosphorylation and CHOP protein expression, but JNK phosphorylation could not be inhibited by CHOP-specific siRNA. Furthermore, Cd exposure significantly increased the intracellular calcium ([Ca2+]i) levels. Buffering the Ca2+ response with BAPTA/AM effectively abrogated the Cd-induced [Ca2+]i elevation, insulin secretion dysfunction, apoptosis, and protein expression of JNK phosphorylation and CHOP activation. Taken together, these findings demonstrated that Cd exposure exerts ß-cell death via a [Ca2+]i-dependent JNK activation-activated downstream CHOP-related apoptotic signaling pathway.

Therapeutic mechanism of combined oral chelation therapy to maximize efficacy of iron removal in transfusion-dependent thalassemia major - a pilot study.

OBJECTIVES: Three iron chelators are used to treat transfusion-dependent beta-thalassemia: desferrioxamine (DFO), deferasirox (DFX), and deferiprone (DFP). Compliance is low for DFO as it cannot be administered orally. Combined administration of DFP and DFX is orally available, however, the therapeutic mechanism is unknown. This pilot study investigated the iron removal mechanisms of DFX and DFP treatment in patients with transfusion-dependent thalassemia major. METHODS: Each patient received three treatments sequentially: (1) DFX monotherapy, (2) DFP monotherapy, and (3) DFX/DFP combination therapy with a four-day washout period between each treatment. Urine and stool specimens were collected to determine the primary outcome of iron excretion volumes. RESULTS: The mean iron excretion was seven times higher after combination therapy with DFX and DFP. Monotherapies also increased excretions volumes, though to a significantly lesser degree. Combined administration of DFX and DFP achieves maximum iron removal in transfusion-dependent thalassemia major compared to monotherapy with either drug. CONCLUSIONS: We suggest combination therapy in chronic severe iron overload cases, especially for patients in poor compliance with DFO/DFP combination therapy or those exhibiting poor iron removal from DFX or DFP monotherapy.

Arsenic, Cadmium and Lead Exposure and Immunologic Function in Workers in Taiwan.

There has been growing concern over the impact of environmental exposure to heavy metals and other trace elements on immunologic functions. This study investigated men's arsenic (As), cadmium (Cd) and lead (Pb) contents in hair samples and their associations with immunological indicators, including white blood cell (WBC), lymphocyte and monocyte counts, and the immunoglobulin (Ig) levels including IgA, IgG and IgE. We recruited 133 men from one antimony trioxide manufacturing plant, two glass manufacturing plants and two plastics manufacturing plants. The mean concentration of Cd [0.16 (SD = 0.03) ug/g] was lower than means of As [0.86 (SD = 0.16) ug/g] and Pb [0.91 (SD = 0.22) ug/g] in hair samples, exerting no relationship with immunologic functions for Cd. The Spearman's correlation analysis showed a positive relationship between monocyte counts and hair Pb levels, but negative relations between As and IgG and between As and IgE. In conclusion, findings from these industry workers suggest that As levels in hair may have a stronger relation with immunologic function than Cd and PB have. Further research is needed to confirm the negative relationship.

Asthma is associated with endometriosis: A retrospective population-based cohort study.

BACKGROUND: Evidence regarding the association between asthma and endometriosis is limited and inconsistent. The goal of the study was to investigate whether women diagnosed as having asthma were at a greater risk of endometriosis than age-matched unaffected women. METHODS: We conducted a nationwide population-based retrospective study by using data retrieved from the Taiwan National Health Insurance Research Database during the period of 2000-2005 with follow-up through 2013. The current analysis included 7337 women aged 12-50 years with newly diagnosed asthma and using asthma-related medications and 29,348 age-matched women without asthma. A Cox proportional hazards regression model was used to estimate the risks of endometriosis in women with asthma as compared with those without asthma. RESULTS: The overall risk of endometriosis in the asthma group was 1.50-fold higher (95% confidence interval = 1.33-1.70) than that in the nonasthma group. A stratified analysis by age further revealed that patients with asthma were associated with a higher risk of endometriosis in age groups of 21-50 years. CONCLUSION: Compared with women without asthma, women with asthma of reproductive age are at a higher risk of endometriosis. Additional studies are warranted to elucidate the mechanism(s) underlying the association between asthma and a higher risk of endometriosis.

Personal, Psychosocial and Environmental Factors Related to Sick Building Syndrome in Official Employees of Taiwan.

Sick building syndrome (SBS) is a combination of symptoms that can be attributed to exposure to specific building conditions. The present study recruited 389 participants aged 20-65 years from 87 offices of 16 institutions to examine if personal factors, work-related psychosocial stress, and work environments, were associated with five groups of SBS symptoms, including symptoms for eyes, upper respiratory tract, lower respiratory tract, skin, and non-specific systems. Indoor environmental conditions were monitored. Data were analyzed using multivariate logistic regression (MLR) analyses and were reported as adjusted Odds Ratios (aOR). SBS symptoms for eyes were associated with older age, sensitivity to tobacco, and low indoor air flow. Upper respiratory symptoms were related to smoking, low social support, longer work days, and dry air. High indoor air flow was associated with reduced upper respiratory symptoms (aOR = 0.29; 95% confidence interval (CI) = 0.13-0.67). Lower respiratory symptoms were associated with high work pressure, longer work hours, chemical exposure, migraine, and exposure to new interior painting. Recent interior painting exposure was associated with a high estimated relative risk of low respiratory symptoms (aOR = 20.6; 95% CI = 2.96-143). Smoking, longer work days, low indoor air flow, indoor dryness, and volatile organics exposure, were associated with other non-specified symptoms including headache, tiredness, difficulty concentrating, anger, and dizziness. In conclusion, there are various SBS symptoms associated with different personal characteristics, psychosocial, and environmental factors. Psychosocial factors had stronger relationships with lower respiratory symptoms than with other types of SBS symptoms. Good ventilation could reduce risk factors and may relieve SBS symptoms.

Assessment of Industrial Antimony Exposure and Immunologic Function for Workers in Taiwan.

This study investigated antimony exposure among employees in industries in Taiwan and evaluated whether their immunologic markers were associated with antimony exposure. We recruited 91 male workers and 42 male office administrators from 2 glass manufacturing plants, 1 antimony trioxide manufacturing plants, and 2 engineering plastic manufacturing plants. Air samples were collected at worksites and administrative offices, and each participant provided specimens of urine, blood, and hair to assay antimony levels. We also determined white blood cells, lymphocyte, and monocyte, IgA, IgE, and IgG in blood specimens. The mean antimony concentration in the air measured at worksites was much higher in the antimony trioxide plant (2.51 ± 0.57 mg/m³) than in plastic plants (0.21 ± 0.06 mg/m³) and glass plants (0.14 ± 0.01 mg/m³). Antimony levels in blood, urine, and hair measured for participants were correlated with worksites and were higher in workers than in administrators. The mean serum IgG, IgA, and IgE levels were lower in workers than in administrators (p < 0.001). Serum IgA and IgE levels in participants were negatively associated with antimony levels in air samples of workplaces, and in blood, urine, and hairs of participants. Serum IgG and IgE of all participants were also negatively associated with antimony levels in their hairs. In conclusion, the antimony exposure is greater for workers employed in the five industrial plants than for administrators. This study suggests serum IgG, IgA, and IgE levels are negatively associated with antimony exposure.