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This review aims to summarize existing approaches and their progress on the interpretation of gas-sensing mechanisms in semiconductor materials.

How to sensitively detect early biomarkers of Alzheimer's disease (AD) is nowadays, one of the major challenges. In this work, Aβ oligomers (AβO), one of the AD biomarkers, was analyzed using an electrochemical aptasensor, which was prepared based on thionine (Th) - functionalized three - dimensional carbon nanomaterials (reduced graphene oxide (rGO) and multi-wall carbon nanotubes (MWCNTs)) immobilized DNA-aptamer. Th, a positively charged planar aromatic molecule, form many π - π conjugated structures with rGO and MWCNTs, then improving the structural stability, electron transfer and the capacitive properties of Th-rGO-MWCNTs nanocomposites. Under the optimal conditions, differential pulse voltammetry (DPV) current responses decreased with the increase of AβO concentration. The obtained AβO aptasensor presented a wide linear range of 0.0443 pM–443.00 pM and limit of detection (LOD) was 10 fM. Meanwhile, AβO aptasensor displayed remarkable stability and selectivity. It has a great potential for early diagnosis of AD in human real serum samples.

International audience; The neurotoxicity of alpha-synuclein oligomers (alpha-syno) could cause Parkinson's disease (PD) which is an irreversible neurodegenerative disease. In order to diagnose and treat PD patients at an early stage and reduce the damage of sampling to humans, a non-invasive measure is used to analyze ultra-trace levels of alpha-syno. In this work, a new impedimetric aptasensor based polythionine (pTH)/Au nanostars (AuNSs) platform was designed for label-free detection of alpha-syno. The pTH and AuNSs demonstrated excellent electrical conductivity, fast electron transfer capability, and the synergistic amplification effect, which could enhance the sensitivity and improve the limit of detection (LOD). The ssDNA aptamers recognized and bound to alpha-syno via specific bases. Therefore, the ultra-sensitive alpha-syno aptasensor based on pTH and AuNSs presented a LOD of 0.07 aM and a dynamic range from 0.10 aM to 10.00 fM. The aptasensor also displayed good response range, high sensitivity, and low LOD in diluted human plasma samples to provide new methods for early diagnosis of PD.

Di (2-ethylhexyl) phthalate (DEHP) is a known environmental endocrine disruptor that impairs development of testis and spermatogenesis. This study aims to explore the effects of STAT3/p53 and PI3K-Akt-mTOR signaling pathway on DEHP-induced reproductive toxicity in pubertal male rat. 24 6-week-old male Sprague-Dawley rats were randomly divided into 4 groups (Control, low-dose, middle-dose and high-dose group) and were treated with increasing concentration of DEHP (0, 250, 500, 1000 mg/kg/day) respectively for 28 consecutive days by intragastric administration. Our results showed that DEHP exposure induced obvious morphological changes of testis, decreased organ coefficient of testis and sperm count, and increased testicular cell apoptosis in the 500 and 1000 mg/kg/day DEHP groups (p .05). The serum testosterone decreased in a dose-dependent manner after treatment with DEHP. Furthermore, the exposure of DEHP elevated the levels of oxidative stress accompanied by upregulated expression of p53 and reduced expression of STAT3. In addition, compared with the control group, the expression of PI3K, p-Akt and p-mTOR proteins significantly decreased, whereas the downstream autophagy-related proteins phosphorylated ULK1, Beclin-1, Atg7, LC3-II obviously increased in the 250 mg/kg/day DEHP group (p .05). The expression of p62 was reduced in DEHP-treated groups. Our data indicated that autophagy could be activated to protect testes from DEHP-induced reproductive damage by inhibiting PI3K-Akt-mTOR signaling pathway in the 250 mg/kg/day DEHP group. STAT3/p53-mediated mitochondrial apoptosis pathway might play a major role to cause testis injury and reproductive dysfunction in the 500 and 1000 mg/kg/day DEHP groups.

To discover the early stage Parkinson’s disease (PD) patients and provide treatment ideas, an ultrasensitive poly (D-glucosamine)/gold nanoparticles/ multi-walled carbon nanotubes/reduced graphene oxide (PDG/AuNPs/MWCNTs/rGO) modified immunosensor was proposed to detect alpha-synuclein oligomer (α-syno), which is the early biomarker in PD. As signal amplification materials, the PDG/AuNPs/ MWCNTs/rGO nanocomplex was immobilized on the glassy carbon electrode surface, and anti-α-syno antibody that specifically recognizes and binds α-syno is then grafted. The immunosensor revealed a linear response between 0.05 fM and 500.00 fM, using square wave voltammetry (SWV), and a detection limit of 0.03fM was found. The immunosensor with excellent sensitivity, selectivity and stability has been applied to the analysis of α-syno in human plasma samples., The authors gratefully acknowledge the financial supports from “ChuTian Scholar” Project Award of Hubei Province of China, the Open Foundation of Hubei Province Key Laboratory of Occupational Hazard Identification and Control (NO. OHIC2018G04) and the National Natural Science Foundation of China (No. 21676305 and No. 81973097).

Intraflagellar transport protein 20 (IFT20) is essential for spermatogenesis in mice. We discovered that COPS5 was a major binding partner of IFT20. COPS5 is the fifth component of the constitutive photomorphogenic-9 signalosome (COP9), which is involved in protein ubiquitination and degradation. COPS5 is highly abundant in mouse testis. Mice deficiency in COPS5 specifically in male germ cells showed dramatically reduced sperm numbers and were infertile. Testis weight was about one third compared to control adult mice, and germ cells underwent significant apoptosis at a pre-meiotic stage. Testicular poly (ADP-ribose) polymerase-1, a protein that helps cells to maintain viability, was dramatically decreased, and Caspase-3, a critical executioner of apoptosis, was increased in the mutant mice. Expression level of FANK1, a known COPS5 binding partner, and a key germ cell apoptosis regulator was also reduced. An acrosome marker, lectin peanut agglutinin (PNA), was nearly absent in the few surviving spermatids, and expression level of sperm acrosome associated 1 (SPACA1), another acrosomal component was significantly reduced. IFT20 expression level was significantly reduced in the Cops5 knockout mice, and it was no longer present in the acrosome, but remained in the Golgi apparatus of spermatocytes. In the conditional Ift20 mutant mice, COPS5 localization and testicular expression levels were not changed. COP9 has been shown to be involved in multiple signal pathways, particularly functioning as a co-factor for protein ubiquitination. COPS5 is believed to maintain normal spermatogenesis through multiple mechanisms, including maintaining male germ cell survival and acrosome biogenesis, possibly by modulating protein ubiquitination. Intraflagellar transport protein 20 (IFT20) is essential for spermatogenesis in mice. We discovered that COPS5 was a major binding partner of IFT20. COPS5 is the fifth component of the constitutive photomorphogenic-9 signalosome (COP9), which is involved in protein ubiquitination and degradation. COPS5 is highly abundant in mouse testis. Mice deficiency in COPS5 specifically in male germ cells showed dramatically reduced sperm numbers and were infertile. Testis weight was about one third compared to control adult mice, and germ cells underwent significant apoptosis at a premeiotic stage. Testicular poly (ADP-ribose) polymerase-1, a protein that helps cells to maintain viability, was dramatically decreased, and Caspase-3, a critical executioner of apoptosis, was increased in the mutant mice. Expression level of FANK1, a known COPS5 binding partner, and a key germ cell apoptosis regulator was also reduced. An acrosome marker, lectin PNA, was nearly absent in the few surviving spermatids, and expression level of sperm acrosome associated 1, another acrosomal component was significantly reduced. IFT20 expression level was significantly reduced in the Cops5 knockout mice, and it was no longer present in the acrosome, but remained in the Golgi apparatus of spermatocytes. In the conditional Ift20 mutant mice, COPS5 localization and testicular expression levels were not changed. COP9 has been shown to be involved in multiple signal pathways, particularly functioning as a co-factor for protein ubiquitination. COPS5 is believed to maintain normal spermatogenesis through multiple mechanisms, including maintaining male germ cell survival and acrosome biogenesis, possibly by modulating protein ubiquitination.

Resonance energy transfer (RET), as an efficient strategy, has been widely used for exploring a variety of biological processes and achieving sensitive bioanalysis. In this work, fluorescence and electrochemiluminescence (ECL) RET between graphitic carbon nitride (g-C3N4) and NIR CdTe/CdS QDs was reported firstly. Based on this novel RET system, a sensitive sandwich-type ECL immunosensor was constructed to detect cancer antigen 125 (CA125). In this strategy, the ECL of Au NPs-functionalized graphitic carbon nitride nanohybrids (Au-g-C3N4 NHs) was efficiently quenched by near-infrared CdTe/CdS quantum dots (NIR CdTe/CdS QDs), where NIR CdTe/CdS QDs acts as acceptors, and Au-g-C3N4 NHs acts as donors. Au NPs improved the intensity and stability of ECL and provided sites to immobilize the antibody. Silica nanospheres carried abundant NIR CdTe/CdS QDs (QDs-SiO2) labeling secondary antibodies, further enhancing the quenching effect. Under the optimum conditions, the constructed immunosensor showed excellent analytical performance with a linear concentration of CA125 from 0.0001 U mL−1 to 10 U mL−1 and the limit of detection reached 0.034 mU mL−1 (S/N = 3). Meanwhile, the immunosensor also revealed great stability, reproducibility, and selectivity and it could be applied in human serum samples successfully. This strategy provided a useful analytical method for the sensitive detection of biomarkers in the early stages of the disease and an innovative reference for developing more efficient and sensitive RET bioanalysis.

Di(2-ethylhexyl) phthalate (DEHP), a plasticizer of synthetic polymers, is a well-known endocrine disrupting chemical (EDC) and reproductive toxicant. Addressing the unclear mechanism of DEHP-induced reproductive dysfunction, this study used GC-2spd cells to investigate the molecular mechanism involved in the DEHP-induced toxicity in the male reproductive system. The results indicated that the apoptotic cell death was significantly induced by DEHP exposure over 100 μM. Furthermore, DEHP treatment could induce oxidative stress in GC-2spd cells involving in the decrease of superoxide dismutase (SOD) activity (200 μM) and glutathione peroxidase (GSH-Px) activity (50 and 100 μM). In addition, DEHP induction also caused the elevated ratios of Bax/Bcl-2, release of cytochrome c and decomposition of procaspase-3 and procaspase-9 in GC-2spd cells. Taken together, our work provided the evidence that DEHP exposure might induce apoptosis of GC-2spd cells via mitochondria pathway mediated by oxidative stress. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1055-1064, 2017.

Mammalian SPAG6, the orthologue of Chlamydomonas reinhardtii PF16, is a component of the central apparatus of the ‘9 + 2’ axoneme that controls ciliary/flagellar motility, including sperm motility. Recent studies revealed that SPAG6 has functions beyond its role in the central apparatus. Hence, we reexamined the role of SPAG6 in male fertility. In wild-type mice, SPAG6 was present in cytoplasmic vesicles in spermatocytes, the acrosome of round and elongating spermatids and the manchette of elongating spermatids. Spag6-deficient testes showed abnormal spermatogenesis, with abnormalities in male germ cell morphology consistent with the multi-compartment pattern of SPAG6 localization. The armadillo repeat domain of mouse SPAG6 was used as a bait in a yeast two-hybrid screen, and several proteins with diverse functions appeared multiple times, including Snapin, SPINK2 and COPS5. Snapin has a similar localization to SPAG6 in male germ cells, and SPINK2, a key protein in acrosome biogenesis, was dramatically reduced in Spag6-deficient mice which have defective acrosomes. SPAG16L, another SPAG6-binding partner, lost its localization to the manchette in Spag6-deficient mice. Our findings demonstrate that SPAG6 is a multi-functional protein that not only regulates sperm motility, but also plays roles in spermatogenesis in multiple cellular compartments involving multiple protein partners.

Mammalian spermatogenesis is a well-organized process of cell development and differentiation. Meiosis expressed gene 1 (MEIG1) plays an essential role in the regulation of spermiogenesis. To explore potential mechanisms of MEIG1's action, a yeast two-hybrid screen was conducted, and several potential binding partners were identified; one of them was membrane occupation and recognition nexus repeat containing 3 (MORN3). MORN3 mRNA is only abundant in mouse testis. In the testis, Morn3 mRNA is highly expressed in the spermiogenesis stage. Specific anti-MORN3 polyclonal antibody was generated against N-terminus of the full-length MORN3 protein, and MORN3 expression and localization was examined in vitro and in vivo. In transfected Chinese hamster ovary cells, the antibody specifically crossed-reacted the full-length MORN3 protein, and immunofluorescence staining revealed that MORN3 was localized throughout the cytoplasm. Among multiple mouse tissues, about 25 kDa protein, was identified only in the testis. The protein was highly expressed after day 20 of birth. Immunofluorescence staining on mixed testicular cells isolated from adult wild-type mice demonstrated that MORN3 was expressed in the acrosome in germ cells throughout spermiogenesis. The protein was also present in the manchette of elongating spermatids. The total MORN3 expression and acrosome localization were not changed in the Meig 1-deficient mice. However, its expression in manchette was dramatically reduced in the mutant mice. Our studies suggest that MORN3 is another regulator for spermatogenesis, probably together with MEIG1.

The work aimed to study the potential correlation between the high-level benzene exposure and its urinary metabolites S-phenylmercapturic acid (SPMA) and trans, trans-muconic acid (t,t-MA) in Chinese shoe-making workers.Individual benzene-exposed levels were determined by gas chromatography analysis, urinary t,t-MA, and urinary SPMA were determined by high performance liquid chromatography-an ultraviolet detector and liquid chromatography/electrospray tandem mass spectrometry method, respectively.The concentration of benzene ranged from 2.57 to 146.11 mg/m³. And the correlation between benzene and t,t-MA was significantly higher than that of SPMA at the postshift, for example, the correlation coefficient was 0.905 and 0.537 for t,t-MA and SPMA, respectively. Moreover, The relative internal exposure index of t,t-MA (0.28 mg/g Cr: mg/m³) was more similar to the data supplied by American Conference of Governmental Industrial Hygienists compared to the index of SPMA (0.025 mg/g Cr:mg/m³).t,t-MA appeared to be a more specific biomarker than SPMA at high-level benzene exposure.

OBJECTIVE This study analyzed the level of urinary S-phenylmercapturic acid (U-SPMA) for low benzene exposure in a group of Chinese shoe-making workers. METHODS Urinary samples from 55 workers exposed to benzene at levels lower than 10 parts per million (ppm) were collected at postshift. U-SPMA level was determined using high-performance liquid chromatography/mass spectrography (HPLC/MS) method. RESULTS Good linearity of U-SPMA was observed within the range from 10 to 320 μg/L (r = 0.9994). Concentration of airborne benzene ranged from 0.71 to 32.17 mg/m³, and three segments were divided with different levels of exposure (≤6.0, 6.0 to 10.0, 10 to 32.5 mg/m³), the median U-SPMA concentrations were 49.55, 102.15, and 335.69 μg/g Cr, respectively. CONCLUSION A good linear correlation was found between U-SPMA levels and airborne benzene concentrations. The selected method could be applied for detecting other working conditions in China.

Human MTH1, an oxidized purine nucleoside triphosphatase, hydrolyzes 8-oxo-dGTP thereby preventing its misincorporation into DNA. The present study was designed to investigate a possible link between the MTH1 Ile45Thr polymorphism and the development of sporadic Parkinson disease (PD). This case-control study consisted of 106 PD patients and 135 unrelated controls. MTH1 polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that Ile45/Thr45 heterozygote and Thr45 allele tended to be more frequent in sporadic PD, although statistically not significant (0.085 vs. 0.044, corrected p = 0.591 and 0.052 vs. 0.022, p = 0.080, respectively). Stratification analysis by gender showed that Ile45/Thr45 heterozygote tended to be more frequent in male PD patients than in male controls (0.113 vs. 0.038, corrected p = 0.480). The male PD patients exhibited a borderline statistically significant higher frequency of the Thr45 allele than the controls (0.073 vs. 0.019, corrected p = 0.050). These results suggested to us that the Thr45 allele of MTH1 might be associated with sporadic PD in the Chinese male population.

To establish the method to determine S-phenylmercapturic acid (S-PMA) in human urine, and the method was actually applied to determine S-PMA concentrations in the human urine from subjects occupationally exposed to benzene.After the urine samples are hydrolyzed by acidification, and modulated to suitable pH value. S-PMA is obtained by liquid-liquid extraction and separated by HPLC. Use negative ion mode electric spray ion source MS to measure, and select the molecular ion peak m/z 238 and quantitative analysis is performed by peak area.This method has good linear in the range of 5-320 microg/L, and r = 0.9994 +/- 0.0003, and the detection limit is 1.2 microg/L (S/N = 3), recovery percentage is 86.8%-94.2%. Both the intra- and inter-day precisions are less than 7%. Use this method to measure the S-PMA in the end-of-shift urine of 55 workers occupationally exposed to benzene and perform the regression analysis for the S-PMA concentration and the benzene concentration in air (r = 0.8035, P0.05).The method established by this research is rapid, sensitive and selective, and the results are accurate and reliable.

Survivin, expressed in almost all types of human malignancies, functions as a key factor in radioresistance primarily by inhibiting apoptosis. This study was conducted to investigate whether survivin plays a role in the DNA repair process in the KB human squamous cell carcinoma cell line.A stable KB cell line overexpressing survivin was established through the use of pIRES2-EGFP vector containing the coding region of survivin. Cells were then irradiated with X-rays and evaluated for DNA double-strand breaks (DSBs) by comet assay and flow cytometry for phospho-histone gammaH2AX. The protein levels of some DSB repair genes were detected by Western blotting analysis.Comet assay and flow cytometry for phospho-histone gammaH2AX showed that overexpression of survivin resulted in significantly fewer DSBs in irradiated cells. Among the DSB repair genes detected, the protein level of Ku70 was up-regulated in survivin-overexpressing KB cells.This finding suggests that survivin may enhance DSB repair capability in KB cells by up-regulating Ku70.

Hormesis, a biphasic dose–response phenomenon, is characterized by a low-dose stimulation and a high-dose inhibition. However, the mechanisms underlying hormesis induced by environmental agents are not well elucidated. The present study was to investigate the relationship between the hormesis effect of cadmium (Cd) and activation of ERK1/2, JNK and p38 pathways in human embryo lung fibroblast cells. Results showed that Cd induced significant cell proliferation at low concentrations, but markedly inhibited cell growth at high concentrations. Our data indicated that cell proliferation promoted by low concentrations of Cd was blocked obviously by ERK1/2 inhibitor PD98059 and partly by JNK inhibitor SP600125; while the decreases of cell proliferation induced by high concentrations of Cd were significantly restored by p38 inhibitor SB203580. Further analysis showed that phospho-ERK1/2 and phospho-JNK activities were increased with different concentrations of Cd, whereas phospho-p38 activity was markedly increased at high concentrations. Our findings suggested that low concentration of Cd induces the ERK and JNK pathways and promotes cell proliferation; while high concentration of Cd induces p38 pathway and inhibits cell proliferation. Activation of the ERK1/2 pathways seems to play a more important role than the JNK pathway in the biphasic effect of Cd on cell proliferation.

Since urinary S-phenylmercapturic acid concentration could be well related to benzene exposure, it could be a sensitive and specific biomarker of low-level benzene exposure. SPMA may be determined by HPLC, LC/MS, GC/MS and ELISA methods. The abroad methods of determination of urinary SPMA were reviewed in detail in recently years and the validation and application of urinary SPMA as a biomarker for occupation benzene exposure were evaluated.

Cadmium is a toxic transition metal of continuing occupational and environmental concern. As a well-recognized human carcinogen, its carcinogenic mechanisms are still poorly understood. Cadmium has long been considered a non-genotoxic carcinogen and thought to act through epigenetic mechanisms. In the present study, we tested the effects of long-term low-dose cadmium exposure on DNA methylation in human embryo lung fibroblast (HLF) cells. After 2 months of exposure to 0-1.5 micromol/L cadmium, both the level of genomic DNA methylation and the enzyme activity of DNA methyltransferases (DNMTs) were increased in a concentration-related manner. Moreover, our results showed that cadmium exposure up-regulated the mRNA levels of DNMT1, DNMT3a and DNMT3b at higher concentrations. We further tested the growth dynamics of HLF cells, and observed significantly elevated growth rates, decreased cell population of G0/G1-phase and increased cell population of S-phase at 0.9, 1.2, and 1.5 micromol/L concentrations. Our study indicated that long-term low-dose cadmium exposure could disrupt DNA methylation, which may be one of the possible underlying carcinogenic mechanisms of cadmium.

A method for the determination of urinary trans, trans-muconic acid (tt-MA) (benzene metabolite) by high performance liquid chromatography (HPLC) was developed. The separation was carried out on a C18 column (Spherisorb C18, 150 mm x 4.6 mm i. d. , 5 microm) at 25 degrees C with glacial acetic acid-tetrahydrofuran-methanol-water (1 : 2 : 10: 87, v/v) as mobile phase. Urinary sample was acidified by 2 mol/L hydrochloric acid and pretreated by liquid-liquid extraction using diethyl ether. After removal of diethyl ether with a stream of nitrogen, the residue was re-dissolved in 1 mL of mobile phase for HPLC injection. Good linearity was observed within the range from 0.10 mg/L to 10.00 mg/L (r =0.9999) and the detection limit was 0.10 mg/L. The average recoveries for tt-MA were 95.1%-100.5%. Relative standard deviations (RSD) for intra-day and inter-day determinations were 4.0%-9.0% and 6.2%-8.8%, respectively. The method was applied to 56 benzene-exposed workers and 24 controll workers. Urinary tt-MA in benzen-exposed workers were significantly higher than that in the control group. They can be correlated with benzene exposure concentrations (P0.01). This analytical method for tt-MA is sensitive, rapid, and convenient. It is suitable for monitoring of occupational exposure to benzene and toxic kinetics studies.

Human MTH1, an oxidized purine nucleoside triphosphatase, hydrolyzes 8-oxo-dGTP thereby preventing its misincorporation into DNA. The present study was designed to investigate a possible link between the MTH1 Ile45Thr polymorphism and the development of sporadic Parkinson disease (PD). This case-control study consisted of 106 PD patients and 135 unrelated controls. MTH1 polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that Ile45/Thr45 heterozygote and Thr45 allele tended to be more frequent in sporadic PD, although statistically not significant (0.085 vs. 0.044, corrected p = 0.591 and 0.052 vs. 0.022, p = 0.080, respectively). Stratification analysis by gender showed that Ile45/Thr45 heterozygote tended to be more frequent in male PD patients than in male controls (0.113 vs. 0.038, corrected p = 0.480). The male PD patients exhibited a borderline statistically significant higher frequency of the Thr45 allele than the controls (0.073 vs. 0.019, corrected p = 0.050). These results suggested to us that the Thr45 allele of MTH1 might be associated with sporadic PD in the Chinese male population.