Interference Morphology of Free-Growing Tendrils and Application of Self-Locking Structures.

Organisms can adapt to various complex environments by obtaining optimal morphologies. Plant tendrils evolve an extraordinary and stable spiral morphology in the free-growing stage. By combining apical and asymmetrical growth strategies, the tendrils can adjust their morphology to wrap around and grab different supports. This phenomenon of changing tendril morphology through the movement of growth inspires a thoughtful consideration of the laws of growth that underlie it. In this study, tendril growth is modeled based on the Kirchhoff rod theory to obtain the exact morphological equations. Based on this, the movement patterns of the tendrils are investigated under different growth strategies. It is shown that the self-interference phenomenon appears as the tendril grows, allowing it to hold onto its support more firmly. In addition, a finite element model is constructed using continuum media mechanics and following the finite growth theory to simulate tendril growth. The growth morphology and self-interference phenomenon of tendrils are observed visually. Furthermore, an innovative class of fluid elastic actuators is designed to verify the growth phenomena of tendrils, which can realize the wrapping and locking functions. Several experiments are conducted to measure the end output force and the smallest size that can be clamped, and the output efficiency of the elastic actuator and the optimal working pressure are verified. The results presented in this study could reveal the formation law of free tendril spiral morphology and provide an inspiring idea for the programmability and motion control of bionic soft robots, with promising applications in the fields of underwater rescue and underwater picking.

Rapid Detection of Hepatitis A Virus in Foods Using a Bioluminescent Assay in Real-Time (BART) and Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) Technology.

Foodborne hepatitis A infections have been considered as a major threat for public health worldwide. Increased incidences of hepatitis A virus (HAV) infection has been associated with growing global trade of food products. Rapid and sensitive detection of HAV in foods is very essential for investigating the outbreaks. Real-time RT-PCR has been most widely used for the detection of HAV by far. However, the technology relies on fluorescence determination of the amplicon and requires sophisticated, high-cost instruments and trained personnel, limiting its use in low resource settings. In this study, a robust, affordable, and simple assay, reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay in combination with a bioluminescence-based determination of amplification in real-time (BART), was developed for the detection of HAV in different food matrices, including green onion, strawberry, mussel, and milk. The efficiencies of a one-step RT-LAMP-BART and a two-step RT-LAMP-BART were investigated for the detection of HAV in different food matrices and was compared with that of real-time RT-PCR. The sensitivity of the RT-LAMP-BART assay was significantly affected by Mg2+ concentration (P < 0.05), in addition to primer quality. The optimal Mg2+ concentration was 2 mM for one-step RT-LAMP-BART and 4 mM for two-step RT-LAMP-BART. Compared with cartridge-purified primers, HPLC-purified primers could greatly improve the sensitivity of the RT-LAMP-BART assay (P < 0.05). For detecting HAV in different food matrices, the performance of two-step RT-LAMP-BART was comparable with that of real-time RT-PCR and was better than that of one-step RT-LAMP-BART. The detection limit of the two-step RT-LAMP-BART for HAV in green onion, strawberry, mussel, and milk was 8.3 × 100 PFU/15 g, 8.3 × 101 PFU/50 g, 8.3 × 100 PFU/5 g, and 8.3 × 100 PFU/40 mL, respectively. The developed RT-LAMP-BART was an effective, simple, sensitive, and robust method for foodborne HAV detection.

Active-chlorine-mediated oxidation of 5-fluorouracil on a hierarchically ordered macroporous RuO2 electrode.

A hierarchically ordered macroporous RuO2 electrode (HOM-RuO2) was fabricated to enhance in situ active chlorine production in an electrochemical system intended for treatment of pharmaceutical active compounds (PhACs). The unique structure of HOM-RuO2 resulted in a decrease of the chlorine evolution potential, a large electro-active area available for in situ conversion of Cl- to active chlorine, and hence improved the active chlorine production by 40%. 5-Fluorouracil (5-FU) was used as a target pollutant to explore the performance of the HOM-RuO2 for PhACs degradation based on the in situ generated active chlorine. The results showed that the reaction rate of active-chlorine-mediated oxidation of 5-FU produced using the HOM-RuO2 was 18.4 times higher than that in the case of hydroxyl radicals (OH)-initiated oxidation using a PbO2 electrode at 30 mA cm-2. The effects of current density and initial solution pH on the 5-FU removal were investigated. The mechanism of 5-FU degradation was proposed taking into accounts both active chlorine production, and change of the speciation of 5-FU caused by pH variations. The dominant degradation products observed for the degradation of 5-FU using the HOM-RuO2 were lactic acid, propanol, acetic acid, urea and other small molecules, but no chlorinated products were detected. These study demonstrates the promise of the HOM-RuO2-based electrochemical systems for the active-chlorine-mediated treatment of recalcitrant pharmaceuticals found in wastewater.

Water mimosa (Neptunia oleracea Lour.) can fix and transfer nitrogen to rice in their intercropping system.

BACKGROUND: Cereal-legume intercropping systems are an environmentally friendly practice in sustainable agriculture. However, research on the interspecific interaction of nitrogen (N) between rice and aquatic legumes has rarely been undertaken. To address this issue, a pot experiment was conducted to investigate N utilization and the N interaction between rice and water mimosa (Neptunia oleracea Lour.) in an intercropping system. The root barrier patterns consisted of solid barrier (SB), mesh barrier (MB), and no barrier (NB) treatments. The N fertilizer application rates were low, medium, and high N rates. RESULTS: The results showed that the NB treatment better facilitated rice growth compared with the MB and SB treatments. And the nitrate N content and urease activity of rice rhizospheric soil in the NB treatment were the highest of the three separated patterns. The ammonium N content in water mimosa rhizospheric soil and N2 fixation of water mimosa ranked as NB > MB > SB. CONCLUSIONS: The amount of N fixation by water mimosa was 4.38-13.64 mg/pot, and the N transfer from water mimosa to rice was 3.97-9.54 mg/pot. This can promote the growth of rice and reduce the application of N fertilizer. We suggest that the rice-water mimosa intercropping system is a sustainable ecological farming approach and can be applied in the field to facilitate rice production. © 2021 Society of Chemical Industry.

Efficient capturing and sensitive detection of hepatitis A virus from solid foods (green onion, strawberry, and mussel) using protamine-coated iron oxide (Fe3O4) magnetic nanoparticles and real-time RT-PCR.

Hepatitis A virus (HAV) continues to be a public health concern and has caused large foodborne outbreaks and economic losses worldwide. Rapid detection of HAV in foods can help to confirm the source of outbreaks in a timely manner and prevent more people getting infected. In order to efficiently detect HAV at low levels of contamination in foods, rapid and easy-to-use techniques are required to separate and concentrate viral particles to a small volume. In the current study, HAV particles were eluted from green onion, strawberry, and mussel using glycine buffer (0.05 M glycine, 0.14 M NaCl, 0.2% (v/v) Tween 20, pH 9.0) and suspended viral particles were captured using protamine-coated magnetic nanoparticles (PMNPs). This process caused a selective concentration of the viral particles, which could be followed by quantitative real-time RT-PCR analysis. Results showed that pH, NaCl concentration, and PMNP amount used for the capturing had significant effects on the recovery efficiency of HAV (P < 0.05). The highest recovery rate was obtained at pH 9.0, 0.14 M NaCl, and 50 µL of PMNPs. The optimized PMNP capturing method enabled the rapid capture and concentration of HAV. A sensitive real-time RT-PCR test was developed with detection limits of 8.3 × 100 PFU/15 g, 8.3 × 101 PFU/50 g, and 8.3 × 100 PFU/5 g of HAV in green onion, strawberry, and mussel, respectively. In conclusion, the PMNP method is rapid and convenient in capturing HAV from complex solid food samples and can generate concentrated HAV sample solutions suitable for high-sensitivity real time RT-PCR detection of the virus.

SENP1-mediated deSUMOylation of JAK2 regulates its kinase activity and platinum drug resistance.

The JAK2/STAT pathway is hyperactivated in many cancers, and such hyperactivation is associated with a poor clinical prognosis and drug resistance. The mechanism regulating JAK2 activity is complex. Although translocation of JAK2 between nucleus and cytoplasm is an important regulatory mechanism, how JAK2 translocation is regulated and what is the physiological function of this translocation remain largely unknown. Here, we found that protease SENP1 directly interacts with and deSUMOylates JAK2, and the deSUMOylation of JAK2 leads to its accumulation at cytoplasm, where JAK2 is activated. Significantly, this novel SENP1/JAK2 axis is activated in platinum-resistant ovarian cancer in a manner dependent on a transcription factor RUNX2 and activated RUNX2/SENP1/JAK2 is critical for platinum-resistance in ovarian cancer. To explore the application of anti-SENP1/JAK2 for treatment of platinum-resistant ovarian cancer, we found SENP1 deficiency or treatment by SENP1 inhibitor Momordin Ic significantly overcomes platinum-resistance of ovarian cancer. Thus, this study not only identifies a novel mechanism regulating JAK2 activity, but also provides with a potential approach to treat platinum-resistant ovarian cancer by targeting SENP1/JAK2 pathway.

Concentration of hepatitis A virus in milk using protamine-coated iron oxide (Fe3O4) magnetic nanoparticles.

Hepatitis A virus (HAV) continues to be the leading cause of viral hepatitis. HAV outbreaks have been linked to the consumption of milk, but methods for HAV detection in milk are very limited. We developed a method to concentrate HAV in milk using protamine-coated iron oxide (Fe3O4) magnetic nanoparticles (PMNPs). In this study, protamine was covalently coated on the surface of the MNPs (20-30 nm) by a three-step chemical reaction. The successful linkage of protamine to the MNPs was confirmed by Fourier transform infrared spectroscopy (FTIR), zeta potential, and transmission electron microscopy (TEM). When used for concentrating HAV from 40 mL of milk, 50 µL of PMNPs were added to the sample and mixed for 20 min by gentle rotation, followed by a magnet capture for 30 min. The captured PMNPs were washed with glycine buffer (0.05 M glycine, 0.14 M NaCl, 0.2% (v/v) Tween 20, pH 9.0) and HAV RNA was extracted using the QIAamp MinElute Virus Spin Kit and quantified by real-time RT-PCR. The method showed a detection limit of 8.3 × 100 PFU of HAV in milk. The whole concentration procedure could be completed in approximately 50 min. The developed method was simple, inexpensive, and easy-to-perform.

Impairment of Mitochondrial Biogenesis and Dynamics Involved in Isoniazid-Induced Apoptosis of HepG2 Cells Was Alleviated by p38 MAPK Pathway.

Isoniazid (INH), a widely used first-line antitubercular drug, has been noted to be associated with hepatotoxicity. In spite of extensive researches over many decades, the mechanism of INH-induced hepatotoxicity still remains poorly understood. Recently, mitochondrial toxicity has been emerging as a new paradigm for INH-induced hepatotoxicity. In this study, we showed that INH impaired mitochondrial biogenesis and dynamics in human hepatocarcinoma HepG2 cells. INH reduced mitochondrial membrane potential (MMP) and induced mitochondria swelling. INH also inhibited the protein expressions of three major mitochondrial biogenesis regulators, SIRT1, PGC1α and NRF1, along with increased acetylation of PGC1α. Meanwhile, INH decreased the number of mitochondria, accompanied by decreased expression of mitochondrial protein COX IV. INH caused mitochondrial fragmentation involving decreased levels of the fusion protein MFN2 as well as the fission protein DRP1. INH-reduced DRP1 expression was associated with the increase of apoptosis, suggesting the existence of pro-survival fission and its involvement in mitochondrial quality control. INH activated p38 MAPK, whereas inhibition of p38 MAPK aggravated INH-induced decreases of SIRT1, PGC1α, NRF1, COX IV and DRP1 expressions. P38 MAPK inhibition also further up-regulated the acetylation of PGC1α and exacerbated INH-induced MMP loss, mitochondrial swelling and apoptosis. Taken together, INH-activated p38 MAPK induced mitochondrial biogenesis to alleviate apoptosis through partly recovering SIRT1-PGC1α pathway activation. In the meantime, p38 MAPK activation by INH promoted protective mitochondrial fission to alleviate apoptosis by partial recovery of DRP1 expression.

The key role of biogenic manganese oxides in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater.

The secondary effluent from biological treatment process in chemical industrial plant often contains refractory organic matter, which deserves to be further treated in order to meet the increasingly stringent environmental regulations. In this study, the key role of biogenic manganese oxides (BioMnOx) in enhanced removal of highly recalcitrant 1,2,4-triazole from bio-treated chemical industrial wastewater was investigated. BioMnOx production by acclimated manganese-oxidizing bacterium (MOB) consortium was confirmed through scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Pseudomonas and Bacillus were found to be the most predominant species in acclimated MOB consortium. Mn2+ could be oxidized optimally at neutral pH and initial Mn2+ concentration below 33 mg L-1. However, 1,2,4-triazole removal by BioMnOx produced occurred optimally at slightly acidic pH. High dosage of both Mn2+ and 1,2,4-triazole resulted in decreased 1,2,4-triazole removal. In a biological aerated filter (BAF) coupled with manganese oxidation, 1,2,4-triazole and total organic carbon removal could be significantly enhanced compared to the control system without the participation of manganese oxidation, confirming the key role of BioMnOx in the removal of highly recalcitrant 1,2,4-triazole. This study demonstrated that the biosystem coupled with manganese oxidation had a potential for the removal of various recalcitrant contaminants from bio-treated chemical industrial wastewater.

And-1 is required for homologous recombination repair by regulating DNA end resection.

Homologous recombination (HR) is a major mechanism to repair DNA double-strand breaks (DSBs). Although tumor suppressor CtIP is critical for DSB end resection, a key initial event of HR repair, the mechanism regulating the recruitment of CtIP to DSB sites remains largely unknown. Here, we show that acidic nucleoplasmic DNA-binding protein 1 (And-1) forms complexes with CtIP as well as other repair proteins, and is essential for HR repair by regulating DSB end resection. Furthermore, And-1 is recruited to DNA DSB sites in a manner dependent on MDC1, BRCA1 and ATM, down-regulation of And-1 impairs end resection by reducing the recruitment of CtIP to damage sites, and considerably reduces Chk1 activation and other damage response during HR repair. These findings collectively demonstrate a hitherto unknown role of MDC1→And-1→CtIP axis that regulates CtIP-mediated DNA end resection and cellular response to DSBs.

Biodegradation mechanism of 1H-1,2,4-triazole by a newly isolated strain Shinella sp. NJUST26.

The highly recalcitrant 1H-1,2,4-triazole (TZ) is widely used in the synthesis of agricultural pesticide and considered to be an environmental pollutant. In this study, a novel strain NJUST26 capable of utilizing TZ as the sole carbon and nitrogen source, was isolated from TZ-contaminated soil, and identified as Shinella sp. The biodegradation assays suggested that optimal temperature and pH for TZ degradation by NJUST26 were 30 °C and 6-7, respectively. With the increase of initial TZ concentration from 100 to 320 mg L(-1), the maximum volumetric degradation rate increased from 29.06 to 82.96 mg L(-1) d(-1), indicating high tolerance of NJUST26 towards TZ. TZ biodegradation could be accelerated through the addition of glucose, sucrose and yeast extract at relatively low dosage. The main metabolites, including 1,2-dihydro-3H-1,2,4-triazol-3-one (DHTO), semicarbazide and urea were identified. Based on these results, biodegradation pathway of TZ by NJUST26 was proposed, i.e., TZ was firstly oxidized to DHTO, and then the cleavage of DHTO ring occurred to generate N-hydrazonomethyl-formamide, which could be further degraded to biodegradable semicarbazide and urea.

MiR-592 inhibited cell proliferation of human colorectal cancer cells by suppressing of CCND3 expression.

Accumulating evidence shows that microRNA (miRNA) is frequently associated with multiple kinds of human cancers, including colorectal cancer (CRC). Previous studies have shown that miR-592 play critical roles in cancer cell biological processes. However, the function of miR-592 in CRC remains largely unknown. In the present study, we investigated the miR-592's role in cell proliferation of colorectal cancer. MiR-592 expression was markedly down-regulated in CRC tissues and CRC cells. Overexpression of miR-592 reduced the proliferation and anchorage-independent growth of CRC cells. Furthermore, bioinformatics analysis further revealed CCND3, a putative tumor promoter, was found to be a potential target of miR-592 in CRC. The dual-luciferase reporter gene assay results showed that CCND3 was a direct target of miR-592. Ectopic expression of miR-592 led to down-regulation of CCND3 protein, which resulted in the down-regulation of phosphorylated retinoblastoma (p-Rb). In functional assays, CCND3-silenced in miR-592-in-transfected SW48 cells have positive effect to suppress cell proliferation, suggesting that direct CCND3 suppression is required for miR-592-induced cell proliferation of CRC. We conclude that miR-592 can regulate CCND3 and function as a tumor suppressor in CRC. Therefore, miR-592 represents a potential anti-onco-miR and serves as a useful therapeutic agent for miRNA-based CRC therapy.

Antitumor Effects of Oncolytic Adenovirus-Carrying siRNA Targeting Potential Oncogene EphA3.

Conditionally replicating adenoviruses (CRAds) armed with antitumor transgenes hold promise for cancer treatment. In previous studies, we showed that the 1504-siRNA targeting potential oncogene EphA3 was an efficient therapeutic transgene and that the telomerase reverse transcriptase promoter (TERTp) driving the CRAd was a more advanced generation of CRAd. Therefore, we combined Ad-TERTp-E1A-1504 by inserting 1504-siRNA into the CRAd to study its antitumor effects and mechanism of action, using Ad-TERTp-E1A-NC and nonreplicating adenovirus carrying 1504-siRNA as controls. Cell viability assays and ED50 studies of growth inhibition confirmed that Ad-TERTp-E1A-1504 has 3.5- and 1,400-fold greater ability to kill EphA3- and TERT-expressing tumor cells compared to Ad-TERTp-E1A-NC and Ad-ΔE1A-1504, respectively. Also, Ad-TERTp-E1A-1504 had little effect on cells that modestly expressed EphA3 and TERT such as 2BS. The antitumor efficacy of Ad-TERTp-E1A-1504 was also validated in vivo. Furthermore, the virus yield of Ad-TERTp-E1A-1504 in C4-2B was ~1,000 times greater than that in 2BS. No obvious differences were observed between Ad-TERTp-E1A-1504 and Ad-TERTp-E1A-NC. Both acridine orange staining and Beclin1 protein measurements indicated that autophagy with Ad-TERTp-E1A-1504 at 5 and 10 MOI was higher than that of Ad-TERTp-E1A-NC. Finally, the classical negatively regulated autophagy signaling pathway, PI3K/AKT/mTOR, was suppressed (reduced phosphorylated form) in contrast to NC, and that this was mediated by 1504-siRNA. Thus, Ad- TERTp-E1A-1504 does not harm normal cells but has dual inhibiting and killing effects on TERT- and EphA3-positive tumor cells, and this effect is mediated by the AKT/mTOR signaling pathway via induction of autophagy. These data may offer a foundation for novel antitumor therapies targeting this mechanism.

Effects of low dose T-2 toxin on secretion of gonadotropin-releasing hormone in the immortalized hypothalamic GT1-7 cell line.

T-2 toxin is one form of trichothecenes, which contaminate crops and feedstuff commonly, and has a wide variety of toxic effects in human and animals, but little is known regarding its role on reproductive function and puberty development. Previous studies have reported that reproductive capacity is attained at puberty triggered by gonadotropin-releasing hormone (GnRH) pulse secretion, and kisspeptins/GPR54 signaling pathway play a central role in the activation of GnRH neurons. For our study, T-2 toxin was tested for its effects on the secretion of GnRH in GT1-7 cells, an immortalized hypothalamic neuron cell line, which could synthesize and secrete GnRH. GT1-7 cells were treated with low doses of T-2 toxin in dose-response assays, with and without kisspeptins, and the levels of GnRH were quantified in each treatment. Furthermore, western blot analysis was used to detect the proteins expression in kisspeptins/GPR54 signaling pathway. The present study demonstrated that low dose T-2 toxin stimulate GnRH secretion and alter the expression of associated proteins in GT1-7 cells in vitro, and the activation of GT1-7 cells response to T- 2 toxin was increased after pretreatment with kisspeptins.

Distribution of DNA adducts and corresponding tissue damage of Sprague-Dawley rats with percutaneous exposure to sulfur mustard.

Sulfur mustard (SM) is a highly reactive alkylation vesicant and cytotoxic agent that has been recognized as an animal and human carcinogen. Although the exact mechanism of toxicology is vague, DNA alkylation seems to be responsible for the triggering of apoptosis. In this study, after male adult Sprague-Dawley rats were cutaneous exposed to a low concentration of SM at parts-per-million levels, their lungs, livers, pancreases, spleens, marrow, and brains were collected at 11 different time points and analyzed. N7-[2-[(2-hydroxyethyl)thio]-ethyl]guanine (N7-HETEG), N3-[2-[(2-hydroxyethyl)thio]-ethyl]adenine (N3-HETEA), and bis[2-(guanin-7-yl)ethyl]sulfide (Bis-G) as the biomarkers for DNA damage were measured in the vital tissues by isotope dilution ultraperformance liquid chromatography tandem mass spectrometry (ID-UPLC-MS/MS). At the same time, general variations and pathological changes were monitored and detected to evaluate the tissue damage. Time- and dose-dependent data showed that SM had strong permeability and reactivity and that three SM-DNA adducts were detected in all investigated tissues only after 10 min after exposure. Obvious dose-dependency was observed except in the brain and pancreas. Most times to peak (tmax) of all three adducts were less than 3 h, while half-lifetimes (t1/2) were less than 24 h. We also suggested that the lipophilic SM can easily pass through the blood-brain barrier and can be stored in the fatty organs. To the best of our knowledge, the abundant adducts in marrow were found and reported for the first time. The surveillance of N7-HETEG in vivo, which was the most abundant adduct, may be the most efficient indicator to validate SM exposure even without any symptoms. Bis-G can be regarded as a biomarker of effect, which is directly related to the extent of damage. The most abundant Bis-G was found in the most sensitive tissues, marrow, spleen, and lung, which is in good accordance with histopathologic results. General variations and pathological changes were evaluated as well. After cutaneous exposure to SM, the body weights of rats heavily decreased in the first 4 days and were inversely proportional to the applied doses, and then recovered at the last experimental day except for those of the rats at the highest dosing level, in which the relative weights of rat spleens were obviously lost. Moreover, we found remarkable histological changes of the lung and skin, such as encephalemia, at the very beginning of the sampling procedure, and plentiful mononuclear cells in marrow appeared 6 h after exposure. The micronucleus test of marrow cells showed that the micronucleus rate had a positively dose-dependent effect.

EphA3, induced by PC-1/PrLZ, contributes to the malignant progression of prostate cancer.

Our previous study revealed the potential linkage of PC-1/PrLZ, a novel isolated prostate-specific gene, to the progression of prostate cancer (PCa) in vitro and in vivo. To gain more insight into the mechanism of PC-1-induced promotion of PCa, expression analysis of differential genes induced by PC-1 was scanned by microarray. Among all the differentially expressed genes, EphA3 was altered to the greatest extent. EphA3 has been identified to be associated with multiple tumor progression. However, little is known concerning the function of EphA3 in PCa. In the present study, we aimed to ascertain whether EphA3 is induced by PC-1 and the functional significance of EphA3 expression in PCa. We found that overexpression of PC-1 increased the amount of EphA3 and that knockdown of PC-1 led to a decrease in EphA3 in PCa cells. The functional significance and mechanisms by which EphA3 contributes to PCa was investigated in vitro using cell lines, and in vivo using a mouse model and clinical specimens. The results showed that EphA3 enhanced the proliferation and survival of LNCaP cells and suppression of EphA3 inhibited the survival of C4-2B cells. EphA3 enhanced the tumor development of LNCaP cells in null mice. A positive correlation between the levels of EphA3 and the Gleason grade of PCa was identified in clinical PCa specimens. In addition, cellular localization changed with Gleason grade. We further detected that EphA3 increased phosphorylation of Akt (Ser473 and Thr308), indicating that EphA3 activated the Akt pathway. Taken together, EphA3 was induced by PC-1 and contributed to the malignant progression of prostate cancer. Our results provide the first demonstration that EphA3 is a novel promoter of human prostate cancer development and progression.

SUMO-specific protease 1 modulates cadmium-augmented transcriptional activity of androgen receptor (AR) by reversing AR SUMOylation.

Cadmium is a potential prostate carcinogen and can mimic the effects of androgen by a mechanism that involves the hormone-binding domain of the androgen receptor (AR), which is a key transcriptional factor in prostate carcinogenesis. We focused on transcriptional activity of AR to investigate the toxicity of cadmium exposure on human prostate cell lines. Cadmium increased the proliferative index of LNCaP and the proliferative effect was obstructed significantly by AR blocking agent. In luciferase assay, cadmium activated the transcriptional activity of AR in 293T cells co-transfected with wild-type AR and an ARE (AR response elements)-luciferase reporter gene. Cadmium also increased expression of PSA, a downstream gene of AR, whereas the metal had no significant effect on AR amount. AR is regulated by multiple posttranslational modifications including SUMOylation. SUMOylated AR shows a lower transcriptional activity. SUMO-specific protease 1 (SENP1) decreases AR SUMOylation by deconjugating AR-SUMO covalent bond. We detected that cadmium increased the amount of SENP1 in a dose and time dependent manner. Knocking down of SENP1 by RNAi led to decrease of PSA expression and transcriptional activity of AR in luciferase assay. Furthermore, co-immunoprecipitation (Co-IP) results showed that SUMOylation level of AR was decreased after cadmium treatment. In conclusion, our results indicated that cadmium-induced SENP1 enhanced AR transcriptional activity by decreasing AR SUMOylation.

Comparison of freely-moving telemetry Chinese Miniature Experiment Pigs (CMEPs) to beagle dogs in cardiovascular safety pharmacology studies.

INTRODUCTION: Telemetry beagle dogs are the most frequently used species in cardiovascular telemetry assessments. However, beagle dogs may not be always suitable for all of the tests. Recently minipigs have received increased attention for these studies. Differences between the two species regarding the response of their cardiovascular systems to environmental stimuli are unclear. This study investigates how the telemetry minipig compares to beagle dog as a test subject and also refines the experimental protocols necessary to obtain accurate data. METHODS: Beagle dogs and Chinese Miniature Experiment Pigs (CMEPs) were implanted with telemetry transmitters and the influences of gavage, feeding and the circadian cycle on various cardiovascular parameters were investigated. RESULTS: ECG signal quality from CMEPs was superior to that of the beagle dogs. Poor ECG signal quality, elevated HR, BP and locomotor activity associated with gavage and feeding were observed in both species. ECG signal quality, BP and locomotor activity recovered more quickly in the CMEPs than in the beagle dogs. Residual elevation of HR found in CMEPs lasted approximately 4h post-feeding, which has a profound influence on the circadian cycle. A diurnal rhythm in CMEP with a significant increase of body temperature during the dark period and a clear circadian rhythm of locomotor activity in both species were observed. DISCUSSION: The present data demonstrated that gavage, feeding and circadian cycle were having an enormous influence on BP, HR and locomotor activity in both species. If drug-induced effects are expected rapidly after oral administration and feeding, CMEP seems to be a favorable choice. Also, due to the effects of feeding on HR, CMEPs should fast at least 5h before the start of recording or should not be fed during the study where the Tmax of a given compound might occur very late. It also should be taken into consideration when the test article has a potential effect on body temperature by using CMEPs. In summary, the telemetry CMEP is a valuable alternative to the beagle dog for cardiovascular telemetry studies.

SGEF enhances EGFR stability through delayed EGFR trafficking from early to late endosomes.

Previously, we demonstrated an elevated SH3-containing guanine nucleotide exchange factor (SGEF) expression in clinical specimens with prostate cancer and implicated the role of SGEF in prostate tumorigenesis. However, the molecular mechanism behind the SGEF regulation of prostate cancer development is not known. In this study, we show that SGEF expression delays epidermal growth factor receptor (EGFR) degradation in prostate cancer cells and is independent from its guanine nucleotide exchange factor (GEF) function. We further show that the delayed degradation is due to a delay in EGFR trafficking from early to late endosomes and not to a decrease in EGFR ubiquitination. Finally, we show that depletion of SGEF significantly inhibits epidermal growth factor-induced EGFR signaling cascade and cell migration in the prostate cancer cells. We report for the first time an SGEF function for RhoG that excludes GEF and the ability of SGEF to enhance EGFR stability and signaling by delaying its lysosomal sorting and degradation. This could be one mechanism by which SGEF contributes to prostate cancer progression.

SGEF is overexpressed in prostate cancer and contributes to prostate cancer progression.

The purpose of this study was to investigate the potential roles of the SH3-containing guanine nucleotide exchange factor (SGEF) in human prostate cancer. Experimental data showed that SGEF was overexpressed in human prostate cancer cells and specimens. The reduction of SGEF expression through an SGEF-targeting siRNA in androgen-independent C4-2 and C4-2B cells suppressed both anchorage-dependent and anchorage-independent growth. In addition, the androgen receptor (AR) antagonist bicalutamide further strengthened this inhibitory effect due to the suppression of the elevated AR transactivation after knockdown of SGEF. Collectively, our results provide the first demonstration that SGEF is a novel promoter of human prostate cancer progression and development.