UiO-66-NH2 initiated cascade reaction: Constructing a ratiometric fluorescence sensor for ultrasensitive detection of nerve agent simulant.

BACKGROUND: Highly toxic organophosphorus nerve agents often exist in the form of gas in the environment and can damage human neuroregulatory system by inhibiting the activity of acetylcholinesterase (AChE). However, fluorescent probes based on small organic molecules bring a secondary burden to environment, and their sensitivity and specificity for sarin simulant diethyl chlorophosphate (DCP) detection are unsatisfactory. Nanozyme cascade systems with signal amplification can be used for highly sensitive identification of analytes, but are rarely used in ratiometric analysis of DCP. Combination of enzyme cascades and ratiometric fluorescence ensures the accuracy and sensitivity of the output signal. RESULTS: We prepared a self-assembled nanohybrid (Ag-AuNCs@UiO-66-NH2) by metal-organic framework material and gold nanoclusters. On the one hand, UiO-66-NH2 with enzyme-like activity was used to hydrolyze DCP into diethyl phosphate (DEP) and chloridion (Cl-). Cl- hindered aggregation-induced enhanced emission (AIEE) of AuNCs by binding with Ag+ and decreased the fluorescence of AuNCs. On the other hand, ligand metal charge transfer effect (LMCT) of UiO-66-NH2 was blocked by DCP to enhance the fluorescence of UiO-66-NH2. Combining ratiometric analysis and nanozyme cascade reaction, an ultra-sensitive fluorescence sensor for detecting DCP was constructed, and ensured the accuracy of experimental results. In addition, Ag-AuNCs@UiO-66-NH2 was embedded into the agarose hydrogel substrate, the resulting agarose hydrogel film allowed quantitative assessment of DCP vapor and high sensitivity was demonstrated (detection limit as low as 1.02 ppb). SIGNIFICANCE: A strategy combining enzyme cascade with ratiometric fluorescence was proposed, which improved the accuracy and sensitivity of the analysis results. The soft-solid platform based on agarose hydrogel film was constructed to realize the quantitative monitoring of sarin simulant gas. The LOD value obtained in this work is much lower than the immediately life-threatening or health threatening concentration of sarin.

Zirconium-based metal-organic framework loaded agarose hydrogels for fluorescence turn-on detection of nerve agent simulant vapor.

Developing reliable sensors that accurately detect deadly chemical gases is critical to global security. Nerve agents are one of the most dangerous chemicals in the world and are often found in gaseous forms in the environment, which remain a challenge to detect because of their low levels. In this paper, a fluorescent probe based on a Zr-based metal-organic framework UiO-66-NH2 was proposed. The specific binding between the Zr-O site of UiO-66-NH2 and diethyl chlorophosphate (DCP) blocked the ligand-to-metal charge transfer (LMCT) process in UiO-66-NH2, thereby enabling the fluorescence turn-on detection of DCP. More importantly, a simple and portable hydrogel soft-solid platform (UiO-66-NH2@Aga) was constructed by incorporating UiO-66-NH2 into the formation process of agarose (Aga) hydrogel for fast and sensitive detection of gaseous DCP. When the hydrogel was exposed to a low concentration of DCP vapor, its fluorescence changed from colorless to bright blue, allowing visualization of the DCP gas for analysis. The UiO-66-NH2@Aga integrated solid-state platform showed an excellent response to DCP vapor in the detection range of 1.98 to 9.90 ppm and with a detection limit of 1.16 ppm. This work opened up a unique way to design a convenient, low cost and practical gas physical examination platform.

Cholesterol crystals activate NLRP3 inflammasomes and promote gallstone formation by increasing mucin secretion.

Cholesterol crystals participate in cholesterol nucleation; however, the role of cholesterol crystals in gallstone development is unknown. Mucin secretion contributes to increased size of gallstones. Cholesterol crystals activate inflammasomes and participate in many sterile inflammation related human diseases. We investigated the role of cholesterol crystals and mucins in sterile inflammation and gallstone enlargement. We found that expression of mucin 5AC (MUC5AC), NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and interleukin-1b (IL-1b) was increased significantly in tissues adjacent to gallstones. Experiments in vitro showed that cholesterol crystals promote MUC5AC secretion; they also increase expression of NLRP3, NLR family CARD domain-containing 4 (NLRC4), apoptosis-associated speck-like protein containing caspase recruitment domain (ASC), and cleaved caspase-1 in biliary epithelial cells. Inhibition of Inflammasomes by NLRP3, ASC or caspase-1 small interfering RNAs reduced MUC5AC secretion. Also, the IL-1 receptor antagonist, IL1RA, and caspase-1 inhibitor, Ac-YVAD, both inhibited MUC5AC secretion induced by cholesterol crystals. We found that inflammasome activation participates in cholesterol crystal induced mucin secretion and gallstone development.

Stable dual-emissive fluorescin@UiO-67 metal-organic frameworks for visual and ratiometric sensing of Al3+ and ascorbic acid.

Encapsulation of fluorophore in metal organic framework (MOF) is an effective method to construct multi-emissive composites. Unfortunately, the small molecules loaded in MOF pores are easy to leak. To overcome this difficulty, fluorescin (FL) is proposed to be encapsulated tightly in the cage of the small tetrahedron of UiO-67, as one of the organic ligands coordinated with the central ion Zr. Finally, stable multi-emission fluorescence was successfully achieved, and Förster resonance energy transfer (FRET) occurred between FL and UiO-67. Ascorbic acid (AA) can dynamically quench the fluorescence of FL@UiO-67 nanoclusters (NCs) through internal filtering effect, photoinduced electron transfer (PET). The detection limit of the probe for AA was as low as 0.20 µM, and the detection range was 0.67 µM-0.36 mM. The probe was further employed to detect Al3+ due to the coordination between Al3+ and the carboxyl group in the FL@UiO-67 NCs. The detection limit for Al3+ was 3.3 nM, and the linear range was 11 nM-5 µM agarose film and test paper were both prepared successfully for visual detection of AA and Al3+. This work provides new ideas for low-cost and convenient real-time detection method.

Primary hepatoid adenocarcinoma of the lung in Yungui Plateau, China: A case report.

BACKGROUND: Hepatoid adenocarcinoma (HAC) occurs in extrahepatic organs such as the gastrointestinal tract, testes, ovaries, lungs, mediastinum and pancreas, and frequently produces α-fetoprotein (AFP). HAC of the lung (HAL) is rare, characterized by difficult treatment and poor prognosis. There are no reports of HAL in Yunnan-Guizhou Plateau, China. CASE SUMMARY: A 60-year-old male patient was clinically diagnosed with HAL pT3N0M0, stage IIB. Chest computed tomography revealed a 7.5 cm × 7.2 cm soft tissue mass located in the right lung upper lobe and the adjacent superior mediastinum. Right upper lobectomy was performed. The diagnosis of HAL was confirmed by pathological examination, and the patient received paclitaxel and carboplatin as adjuvant chemotherapy after surgery. CONCLUSION: Clinical manifestations, pathological features, imaging findings, auxiliary examination, and treatment planning of HAL are presented to help clinicians improve their diagnosis and treatment.

[Development of Tianma HPLC fingerprint and discriminant analysis].

Tianma(the tuber of Gastrodia eleta) is a widely used and pricy Chinese herb. Its counterfeits are often found in herbal markets, which are the plant materials with similar macroscopic characteristics of Tianma. Moreover, the prices of Winter Tianma(cultivated Tianma) and Spring Tianma(mostly wild Tianma) have significant difference. However, it is difficult to identify the true or false, good or bad quality of Tianma samples. Thus, a total of 48 Tianma samples with different characteristics(including Winter Tianma, Spring Tianma, slice, powder, etc.) and 9 plant species 10 samples of Tianma counterfeits were collected and analyzed by HPLC-DAD-MS techniques. After optimizing the procedure of sample preparation, chromatographic and mass-spectral conditions, the HPLC chromatograms of all those samples were collected and compared. The similarities and Fisher discriminant analysis were further conducted between the HPLC chromatograms of Tianma and counterfeit, Winter Tianma and Spring Tianma. The results showed the HPLC chromatograms of 48 Tianma samples were similar at the correlation coefficient more than 0.848(n=48). Their mean chromatogram was simulated and used as Tianma HPLC fingerprint. There were 11 common peaks on the HPLC chromatograms of Tianma, in which 6 main peaks were chosen as characteristic peaks and identified as gastrodin, p-hydroxybenzyl alcohol, parishin A, parishin B, parishin C, parishin E, respectively by comparison of the retention time, UV and MS data with those of standard chemical compounds. All the six chemical compounds are bioactive in Tianma. However, the HPLC chromatograms of the 10 counterfeit samples were significantly different from Tianma fingerprint. The correlation coefficients between HPLC fingerprints of Tianma with the HPLC chromatograms of counterfeits were less than 0.042 and the characteristic peaks were not observed on the HPLC chromatograms of these counterfeit samples. It indicated the true or false Tianma can be identified by either the similarity or characteristic peaks on HPLC fingerprint. Comparing the Winter Tianma with Spring Tianma showed that the HPLC chromatograms of 15 winter Tianma samples and 11 spring Tianma samples were similar at the mean correlation coefficient of 0.908. But the intensity of the characteristic peaks were different between the two groups of Tianma samples, i.e. the intensity of gastrodin, paishin A and C in winter Tianma was lower than those in spring Tianma. The Winter Tianma and Spring Tianma could be discriminated by either the Fisher unstandardized discrimination function or Linear discriminant function, based on the peak areas of 11 common peaks on HPLC chromatograms as variate.

Interleukin-1ß-mediated suppression of microRNA-101 and upregulation of enhancer of zeste homolog 2 is involved in particle-induced lung cancer.

Lung cancer may be a result of complex factors. Small mineral particle is the well-known inducer of lung cancer. Previous study revealed the high morbidity of lung cancer in Xuan Wei in China, and the main cause of lung cancer is the use of smoky coal there. And it is generally accepted that chronic inflammation induced by small mineral particle may be a cause of lung cancer. But the relationship between chronic lung inflammation and lung cancer is largely unknown. In the present study, we found that silica particle was able to induce the secretion of interleukin-1ß from a Xuan Wei lung cancer cell line, XWLC-05. At the same time, microRNA-101 (mir-101) was found to be downregulated by the treatment of silica particle. Interestingly, the interleukin 1 receptor antagonist and interleukin-1ß antibody can reduce silica particle-induced downregulation of mir-101. Twenty-four Xuan Wei lung tumor tissues were collected to detect the expression level of mir-101 and enhancer of zeste homolog 2 (EZH2), which is the potential target of mir-101. The results showed that mir-101 was down-regulated and EZH2 were upregulated. Subsequently, the roles of mir-101 and EZH2 in tumor growth and progression in vitro were tested. Overexpression of mir-101 mimics was able to suppress the expression of EZH2 in XWLC-05 cells. And this resulted in the inhibited tumor cell growth and attenuated cell migration. The results in the present study showed that particle can induce the secretion of interleukin-1ß. Interleukin-1ß subsequently induces the downregulation of mir-101, which may result in the upregulated level of EZH2, and occurrence of lung cancer. We for the first time proposed the role interleukin-1ß-mir-101-EZH2 axes in the particle-induced lung cancer. Further study may be needed to decipher the detailed mechanism involved.

Prenatal caffeine ingestion induces aberrant DNA methylation and histone acetylation of steroidogenic factor 1 and inhibits fetal adrenal steroidogenesis.

Prenatal caffeine ingestion is one of the risk factors for intrauterine growth retardation (IUGR). Adrenal plays a pivotal role, mainly through steroidogenesis, in the regulation of intrauterine homeostasis and in fetal development and maturation. We have shown that prenatal caffeine ingestion can inhibit fetal adrenal corticosterone production, but the underlying mechanism is unknown. This study investigated the effects of prenatal caffeine ingestion on corticosterone and its associated synthesized enzymes (steroidogenic acute regulatory protein, StAR; 3ß-hydroxysteroid dehydrogenase, 3ß-HSD; cytochrome P450 cholesterol side chain cleavage, P450scc; P450c21; and P450c11) in the fetal adrenal in rats and further explored the underlying mechanism by analyzing the epigenetic modification and expression of the key transcription factor steroidogenic factor-1 (SF-1). The pregnant rats were intragastrically treated with 120 mg/kg.d caffeine from gestational day 11-20. The results showed that the IUGR rate was 51.2% after caffeine treatment. The contents of corticosterone and the mRNA levels of StAR, P450scc, P450c21, and P450c11 were decreased significantly in the fetal adrenal. Furthermore, caffeine reduced both the protein and the mRNA expression of SF-1 in the fetal adrenal. The epigenetic analysis showed that caffeine treatment can significantly enhance the mRNA expression of DNA methyltransferase (Dnmt) 1, Dnmt3a, histone deacetylases (Hdac) 1, and Hdac2. The detection of DNA methylation by bisulfite-sequencing PCR uncovered a notably increased total methylation rate in the SF-1 promoter. The ChIP assay showed decreased acetylation levels of H3K9 and H3K14 in the SF-1 promoter. In conclusion, prenatal caffeine ingestion is able to induce aberrant DNA methylation and histone acetylation of the SF-1 promoter in the rat fetal adrenal. These effects may contribute to the inhibition of the expression of SF-1 and its associated steroidogenic enzymes and the production of corticosterone during fetal development.

Prenatal nicotine exposure enhances the susceptibility to metabolic syndrome in adult offspring rats fed high-fat diet via alteration of HPA axis-associated neuroendocrine metabolic programming.

AIM: Prenatal nicotine exposure (PNE) alters the hypothalamic-pituitary-adrenocortical (HPA) axis-associated neuroendocrine metabolic programming in intrauterine growth retardation offspring rats. In this study we aimed to clarify the susceptibility to metabolic diseases of PNE offspring rats fed a high-fat diet. METHODS: Maternal Wistar rats were injected with nicotine (1.0 mg/kg, sc) twice per day from gestational day 11 until full-term delivery, and all pups were fed a high-fat diet after weaning and exposed to unpredictable chronic stress (UCS) during postnatal weeks 18-20. Blood samples were collected before and after chronic stress, and serum ACTH, corticosterone, glucose, insulin, total cholesterol, triglyceride and free fatty acids levels were measured. The hypothalamus, pituitary gland and liver were dissected for histological studies. RESULTS: UCS significantly increased the serum ACTH, corticosterone and insulin levels as well as the insulin resistant index without changing the serum glucose, total cholesterol, triglyceride and free fatty acids levels in adult offspring rats without PNE. The body weight of PNE offspring rats presented a typical "catch-up" growth pattern. PNE not only aggravated the UCS-induced changes in the HPA axis programmed alteration (caused further increases in the serum ACTH and corticosterone levels), but also significantly changed the glucose and lipid metabolism after UCS (caused further increases in the serum glucose level and insulin resistant index, and decrease in the serum free fatty acids). The effects of PNE on the above indexes after UCS showed gender differences. Pathological studies revealed that PNE led to plenty of lipid droplets in multiple organs. CONCLUSION: PNE enhances not only the HPA axis, but also the susceptibility to metabolic diseases in adult offspring rats fed a high-fat diet after UCS in a gender-specific manner and enhances the susceptibility to metabolic diseases in adult offspring rats fed a high-fat diet.

Inheritable stimulatory effects of caffeine on steroidogenic acute regulatory protein expression and cortisol production in human adrenocortical cells.

Caffeine is the most widely consumed psychoactive substance in the world. It can elevate the level of glucocorticoid which is involved in metabolism regulation, stress response, and immune function. However, the specific mechanism has yet to be elucidated. Glucocorticoid is steroid hormone synthesized in adrenal cortex and the key rate-limiting step in its biosynthesis is mediated by steroidogenic acute regulatory protein (StAR). This study was designed to investigate the direct effects and inheritable epigenetic mechanisms of caffeine on cortisol production and StAR expression in human adrenocortical cells. The human adrenocortical cell line NCI-H295A was cultured with 0.4-40µM caffeine. There was a significant increase of the cortisol production in cells. In both acutely and chronically caffeine-treated cell groups, mRNA and protein expressions of StAR were stimulated in a dose-dependent manner. DNA methylation detection via bisulfite-sequencing PCR (BSP) uncovered a single site CpG demethylation at nt -682 within the StAR promoter region. Then we investigated how long the increased StAR expression and the single CpG demethylation could last. The caffeine was withdrawn after 48h of treatment and then the cells were continually subcultured for up to 5 and 10 passages, respectively. The results showed that the StAR expression at post-caffeine passage 10 still increased, as compared with that in the control. The caffeine-induced demethylation at nt -682 in StAR promoter underwent a similar time course as StAR expression does. The present study reveals the direct effect and possible inheritable epigenetic mechanism of caffeine on steroidogenesis in human adrenocortical cells and has implications for our understanding of the consumption of caffeine.

[Effects of hydrodynamics-mediated RNAi on Mfn2 expression, blood sugar and fat levels in mice].

OBJECTIVE: To investigate the effects of hydrodynamics-mediated RNAi for Mfn2 gene expression in liver and the levels of blood sugar and fat in mice. METHODS: Fifty-six male BALB/c mice were randomly divided into normal control group (NC, n = 8), negative control group (HK, n = 24) and transfection group (Mfn2, n = 24) according to random digits table. 1.5 ml plasmid (negative control or Mfn2 shRNA, 75mug for each mouse) diluted into phosphate buffered solution (PBS) was injected into the HK and Mfn2 groups mice via hydrodynamic intravascular injection. Mfn2 mRNA and protein expression in hepatic tissue was detected by RT-PCR and Western-blot 24 hours, 72 hours and 120 hours respectively after injection. At the same time, the levels of fasted blood sugar (FBS) and triglyceride (TG) were measured. RESULTS: Compared with HK mice, the expressions of Mfn2 mRNA (1.00+/-0.03 vs 1.14+/-0.07, t = 4.027, P = 0.007; 1.01+/-0.053 vs 1.18+/-0.07, t = 4.234, P = 0.006) and protein (7.81+/-0.80 vs 8.01+/-0.08, t = 2.941, P = 0.042; 8.05+/-0.15 vs 8.56+/-0.014, t = 4.883, P = 0.039) decreased markedly in Mfn2 mice in 72 and 120 hours after injection. In the fasting state, in 24 hours after injection, FBS in Mfn2 group was significantly lower than that in HK group [(2.65+/-0.70 vs 5.28+/-0.82) mmol/L, t = 6.879, P value less than 0.01] and TG was also significantly higher than that in HK group [(1.96+/-0.32 vs 1.12+/-0.16) mmol/L, t = -6.711, P value less than 0.01]. No statistical differences found between the NC and HK groups for FBS and TG (F = 1.412, P = 0.26; F = 2.711, P = 0.14). The plasma glucose level in Mfn2 mice was significantly higher than that in HK mice [(7.23+/-0.82 vs 5.18+/-0.69) mmol/L, t = 2.050, P value less than 0.01; (7.00+/-0.67 vs 6.05+/-0.76) mmol/L, t = 3.57, P = 0.023] in 72 and 120 hours after injection. However, no differences found between the two groups for blood TG [(1.53+/-0.27 vs 1.37+/-0.18) mmol/L, t = 0.160, P = 0.23; (1.84+/-0.30 vs 1.52+/-0.37) mmol/L, t = 0.330, P = 0.503]. CONCLUSION: The data indicate that hydrodynamics- mediated RNAi for Mfn2 gene can effectively inhibit the expression of target gene in mice liver in 72 and 120 hours after shRNA administration, and the inhibition of hepatic Mfn2 can induce glycometabolic and fat metabolic disorder.