Growth of Scenedesmus obliquus in anaerobically digested swine wastewater from different cleaning processes for pollutants removal and biomass production.

Anaerobically digested swine wastewater (ASW) purification by microalgae provides a promising strategy for nutrients recovery, biomass production and CO2 capture. However, the characteristics of ASW from different cleaning processes vary greatly. At present, the cultivation of microalgae in ASW from different manure cleaning processes is rarely investigated and compared. That may bring uncertainty for microalgae growth using different ASW in large-scale application. Thus, the ASW from three cleaning processes were tested for cultivating microalgae, including manure dry collection (I), water flushing (II) and water submerging processes (III). The characteristics of ASW from three manure cleaning processes varied greatly such as nutrient and heavy metals levels. High concentration of ammonia and copper in ASW significantly inhibited microalgae growth. Fortunately, the supply of high CO2 (10%) effectively alleviated negative influences, ensuring microalgal growth at low dilution ratio. The characteristics of three ASW resulted in significant differences in microalgae growth and biomass components. The maximal biomass production in optimal diluted ASW-I, II and III reached 1.46 g L-1, 2.19 g L-1 and 2.47 g L-1, respectively. The removal of organic compounds, ammonia and phosphorus by optimal microalgae growth in diluted ASW-I, II and III was 50.6%/94.2%/64.7%, 63.7%/82.3%/57.6% and 83.2%/91.7%/59.7%, respectively. The culture in diluted ASW-I, II and III obtained the highest lipids production of 12.1 mg L-1·d-1, 16.5 mg L-1·d-1 and 19.4 mg L-1·d-1, respectively. The analysis of lipids compositions revealed that the proportion of saturated fatty acids accounted for 36.4%, 32.4% and 27.9 % in optimal diluted ASW-I, II and III, as ideal raw materials for biodiesel production.

Indole Diterpenes from Mangrove Sediment-Derived Fungus Penicillium sp. UJNMF0740 Protect PC12 Cells against 6-OHDA-Induced Neurotoxicity via Regulating the PI3K/Akt Pathway.

In our chemical investigation into Penicillium sp. UJNMF0740 derived from mangrove sediment, fourteen indole diterpene analogs, including four new ones, are purified by multiple chromatographic separation methods, with their structures being elucidated by the analyses of NMR, HR-ESIMS, and ECD data. The antibacterial and neuroprotective effects of these isolates were examined, and only compounds 6 and 9 exhibited weak antibacterial activity, while compounds 5, 8, and 10 showed protective effects against the injury of PC12 cells induced by 6-hydroxydopamine (6-OHDA). Additionally, compound 5 could suppress the apoptosis and production of reactive oxygen species (ROS) in 6-OHDA-stimulated PC12 cells as well as trigger the phosphorylation of PI3K and Akt. Taken together, our work enriches the structural diversity of indole diterpenes and hints that compounds of this skeleton can repress the 6-OHDA-induced apoptosis of PC12 cells via regulating the PI3K/Akt signaling pathway, which provides evidence for the future utilization of this fascinating class of molecules as potential neuroprotective agents.

[Analysis of Microbial Interaction Law of Mud Membrane in IFAS Process for Treating Low Carbon Source Sewage in South China].

To assess the problem of sewage treatment under the condition of low carbon sources, we carried out a study of activated sludge and a biofilm symbiosis system (IFAS). The occurrence characteristics and interaction law of microorganisms in two phases of sludge membrane under low carbon source conditions were discussed, and their niche and influence on treatment efficiency were clarified. Through a pilot-scale experiment in actual water plants, the biofilm characteristics, sludge membrane activity, and succession law of flora were analyzed, and the microbial structure and interaction in sludge membrane in two phases under the control of different activated sludge ages were compared. The results showed that the sludge concentration in the reactor increased with the increase in SRT under variable SRT. Because the microbial concentration in SRT-H was much higher than that in SRT-L, the competition between mud films in SRT-H was more intense than that in SRT-L, and the pollutant removal efficiency in SRT-H was lower than that in SRT-L. Under the condition of low-carbon feed water, the sludge activity in the IFAS process decreased with the increase in SRT. Under the condition of low SRT(5 d), the nitrification, denitrification, phosphorus accumulation, and phosphorus absorption rate of activated sludge increased by 122%, 88%, 34%, and 44%, respectively, compared with that of high SRT (25 d). However, SRT had little effect on biofilm activity, and there was little difference in nitrification activity and denitrification activity between the two SRTs. Microbial sequencing analysis showed that the functional bacteria of the IFAS process were enriched and transferred with the change in SRT between the two phases of mud membrane. In SRT-L, the functional bacteria that were enriched and transferred between the two phases of mud film owing to the "seeding" effect were mainly unclassified_g__Enterobacteriaceae, whereas in SRT-H, Acinetobacter was mainly used. At the same time, by analyzing the distribution of dominant functional bacteria, it was found that there was some competition between denitrifying bacteria and phosphorus-accumulating bacteria in activated sludge. Under the condition of a lack of organic substrate in the influent, the relative abundance of denitrifying bacteria was obviously higher than that of phosphorus-accumulating bacteria, which indicated that denitrifying bacteria could better adapt to low-carbon source conditions. Thus, they could occupy a dominant competition position, which was mainly reflected in the increase in the relative abundance of aerobic denitrifying bacteria. In addition, the SRT change in the mud phase reacted in the membrane phase, making the residence time of biofilm change correspondingly, thus changing the flora structure, screening out different dominant bacteria genera, and further increasing the difference.

Annual Herbaceous Plants Exhibit Altered Morphological Traits in Response to Altered Precipitation and Drought Patterns in Semiarid Sandy Grassland, Northern China.

The frequency and intensity of extreme precipitation events and severe drought are predicted to increase in semiarid areas due to global climate change. Plant morphological traits can reflect plant responses to a changing environment, such as altered precipitation or drought patterns. In this study, we examined the response of morphological traits of root, stem, leaf and reproduction meristems of annual herbaceous species to altered precipitation and drought patterns in a semiarid sandy grassland. The study involved a control treatment (100% of background precipitation) and the following six altered precipitation treatments: (1) P(+): precipitation increased by 30%, (2) P(++): precipitation increased by 60%, (3) P(-): precipitation decreased by 30%, (4) P(--): precipitation decreased by 60%, (5) drought 1 (D1): 46-day drought from May 1st to June 15th, and (6) drought 2 (D2): 46-day drought from July 1st to August 15th. P(++) significantly increased root length, flower length-to-width ratio, both P(+) and P(++) significantly increased stem length and flower number in the plant growing seasons, while all of them decreased under P(-) and P(--). The annual herbaceous plants marginally increased the number of second-level stem branches and stem diameter in order to better resist the severe drought stress under P(--). P(+) and P(++) increased the root, stem, leaf, and flower dry weight, with the flower dry weight accounting for a larger proportion than the other aboveground parts. Under D2, the plants used the limited water resources more efficiently by increasing the root-to-shoot ratio compared with P(-), P(--) and D1, which reflects biomass allocation to belowground increased. The linear mixed-effects models and redundancy analysis showed that the root-to-shoot ratio and the dry weight of various plant components were significantly affected by morphological traits and altered precipitation magnitude. Our results showed that the herbaceous species have evolved morphological trait responses that allow them to adapt to climate change. Such differences in morphological traits may ultimately affect the growing patterns of annual herbaceous species, enhancing their drought-tolerant capacity in semiarid sandy grassland during the ongoing climate change.

Real world effectiveness of PCSK-9 inhibitors combined with statins versus statins-based therapy among patients with very high risk of atherosclerotic cardiovascular disease in China (RWE-PCSK study).

BACKGROUND: The efficacy and safety of proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors were confirmed by several clinical trials, but its effectiveness in routine clinical practice in China has not been evaluated. This study aims to describe the real world effectiveness of PCSK-9 inhibitors combined with statins compared with statins-based therapy among patients with very high risk of atherosclerotic cardiovascular disease (ASCVD). METHODS: This is a multi-center observational study, enrolled patients from 32 hospitals who underwent percutaneous coronary intervention (PCI) from January to June in 2019. There are 453 patients treated with PCSK-9 inhibitors combined with statins in PCSK-9 inhibitor group and 2,610 patients treated with statins-based lipid lowering therapies in statins-based group. The lipid control rate and incidence of major adverse cardiovascular events (MACE) over six months were compared between two groups. A propensity score-matched (PSM) analysis was used to balance two groups on confounding factors. Survival analysis using Kaplan-Meier methods was applied for MACE. RESULTS: In a total of 3,063 patients, 89.91% of patients had received moderate or high-intensity statins-based therapy before PCI, but only 9.47% of patients had low-density lipoprotein cholesterol (LDL-C) levels below 1.4 mmol/L at baseline. In the PSM selected patients, LDL-C level was reduced by 42.57% in PCSK-9 inhibitor group and 30.81% (P < 0.001) in statins-based group after six months. The proportion of LDL-C ≤ 1.0 mmol/L increased from 5.29% to 29.26% in PCSK-9 inhibitor group and 0.23% to 6.11% in statins-based group, and the proportion of LDL-C ≤ 1.4 mmol/L increased from 10.36% to 47.69% in PCSK-9 inhibitor group and 2.99% to 18.43% in statins-based group ( P < 0.001 for both). There was no significant difference between PCSK-9 inhibitor and statins-based treatment in reducing the risk of MACE (hazard ratio = 2.52, 95% CI: 0.49-12.97, P = 0.250). CONCLUSIONS: In the real world, PCSK-9 inhibitors combined with statins could significantly reduce LDL-C levels among patients with very high risk of ASCVD in China. The long-term clinical benefits for patients received PCSK-9 inhibitor to reduce the risk of MACE is still unclear and requires further study.

Construction of TiO2-Eggshell for Efficient Degradation of Tetracycline Hydrochloride: Sunlight Induced In-Situ Formation of Carbonate Radical.

Photocatalytic degradation of an antibiotic by utilizing inexhaustible solar energy represents an ideal solution for tackling global environment issues. The target generation of active oxidative species is highly desirable for the photocatalytic pollutants degradation. Herein, aiming at the molecular structure of tetracycline hydrochloride (TC), we construct sunlight-activated high-efficient catalysts of TiO2-eggshell (TE). The composite ingeniously utilizes the photoactive function of TiO2 and the composition of eggshell, which can produce oxidative ·CO3- species that are especially active for the degradation of aromatic compounds containing phenol or aniline structures. Through the synergistic oxidation of the··CO3- with the traditional holes (h+), superoxide radicals (·O2-) and hydroxyl radicals (·OH) involved in the photocatalytic process, the optimal TE photocatalyst degrades 92.0% TC in 30 min under solar light, which is higher than TiO2 and eggshell. The photocatalytic degradation pathway of TC over TE has been proposed. The response surface methodology is processed by varying four independent parameters (TC concentration, pH, catalyst dosage and reaction time) on a Box-Behnken design (BBD) to optimize the experimental conditions. It is anticipated that the present work can facilitate the development of novel photocatalysts for selective oxidation based on ·CO3-.

Responses of annual herb plant community characteristics to increased precipitation and reduced wind velocity in semiarid sandy grassland.

Changes in precipitation regimes and wind velocity tend to alter structure and composition of the annual herb plant community, with consequent effects on ecological functioning and biodiversity maintenance. We examined the effects of increased precipitation and reduced wind velocity on annual herb plant community characteristics via a manipulative experiment from the middle of April to middle of August, 2016. There was significant increment in species richness with increased precipitation from June to August, and there were interactive effects between increased precipitation and reduced wind velocity especially in June and the end of July. From June to August, increased precipitation, reduced wind velocity as well as their interaction stimulated sandy plant community development. There was considerable elevation in plant coverage with increased precipitation, and also there was an interactive effect of increased precipitation with 20% reduced wind velocity. However, reduced wind velocity caused more significant stimulation (p < .01) in plant height. Moreover, dominant plants, Salsola collina, Bassia dasyphylla, and Setaria viridis, contributed equally to the elevated community coverage with increased precipitation, whereas S. collina occupied a much larger proportion on the augment of community height compared with the other two species under the increased precipitation and reduced wind velocity. Elevated Shannon-Wiener index was detected with increased precipitation in June and July. Furthermore, increased precipitation and reduced wind velocity enhanced aboveground and belowground biomass, respectively. These species traits-in structuring and composing plant community were suggested to be conducive to deep understanding the plant functioning and dynamics under global changing precipitation regimes and atmospheric wind velocity scenarios.

Neuroprotective effects of cordycepin inhibit Aß-induced apoptosis in hippocampal neurons.

In Alzheimer's disease (AD), ß-amyloid (Aß) protein toxicity increases the formation of reactive oxygen species (ROS) and intracellular calcium levels, resulting in neuronal dysfunction, neurodegenerative disorders, and cell death. Cordycepin is a derivative of the nucleoside adenosine; also, it is speculated to exert neuroprotective effects against Aß-induced oxidative toxicity in hippocampal neurons. In the present study, the fluorescence detection method and whole-cell patch-clamp recordings were used to study the neuroprotective effects against Aß-induced toxicity in the primary hippocampal cultured neurons. The results revealed that Aß25-35 toxicity causes increased cellular ROS production and abnormal calcium homeostasis in hippocampal neurons. Moreover, Aß25-35-induced cytotoxicity led to a series of downstream events, including the activation of acetylcholinesterase, increased p-Tau expression, and increased apoptosis. Cordycepin inhibits ROS production, elevated levels of Ca2+ induced by Aß25-35, and the activation of acetylcholinesterase; all these are involved in oxidative-induced apoptosis. In addition, it decreases the increased p-Tau expression that plays a key role in the initiation of the AD. Results showed that the anti-apoptotic effects of cordycepin are partially dependent on the activation of adenosine A1 receptor, whereas an antagonist selectively attenuated the neuroprotective effects of cordycepin. Collectively, these results suggest that cordycepin could be a potential future therapeutic agent for neuronal disorders, such as AD.

Increased pollinator service and reduced pollen limitation in the fixed dune populations of a desert shrub.

Evaluations of restoration success usually focus on the structural aspects of ecosystems. Pollination, as an important functional aspect, is often overlooked. Here, the shifts in pollinator assemblage and pollen limitation in the desert shrub Caragana microphylla were examined along a restoration gradient in Horqin Sand Land, northern China. We identified seven species of bees; however, only four bee species were found to be effective pollinators, with Xanthosaurus remota dominating in the fixed dunes, and with no bee species or only a single species, X. remota, being observed in the semi-fixed and mobile dunes. Flower visitation rate was nearly ten times higher in the fixed dunes than in the mobile and semi-fixed dunes. Experimental floral manipulations revealed that the fixed dune populations experienced less pollen limitation, along with the increase in pollinator availability. Between the mobile and semi-fixed dune populations, pollen limitation was severe and at similar levels. The intensity of pollen limitation was negatively related to pollinator abundance and richness. Overall, the dependence on pollinators for reproduction may be an important constraint that limits persistence in this system. Increased pollinator service during the restoration process may ameliorate pollen limitation, benefiting the restoration of vegetation in this semiarid sandy area.

Anti-effects of cordycepin to hypoxia-induced membrane depolarization on hippocampal CA1 pyramidal neuron.

Cordycepin has important neuroprotective effects in hypoxic or ischemic insult. However, the direct electrophysiological evidence of cordycepin's neuroprotection from hypoxic or ischemic insult remains unknown. Hence, in this study, the electrophysiological mechanism by which cordycepin protects against ischemic and hypoxic damages has been studied using an energy-deprivation injury model through whole-cell patch clamp techniques. Results revealed that cordycepin (80µM) significantly delayed hypoxia-induced membrane depolarization, including cordycepin reduced slope, and extended the duration of slow depolarization, prolonged the ability to generate spontaneous action potential (AP) firing, delayed the onset of rapid depolarization, and maintained the more hyperpolarized membrane potential after rapid depolarization. Additionally, cordycepin also delayed the hypoxia-induced decrease in the evoked AP amplitude. Furthermore, cordycepin can rescue the neuronal electrophysiological function after the 5min hypoxia pretreatment insult as seen the recovery on the evoked spike amplitude, membrane potential, and evoked AP latency during reoxygenation of hippocampal slices with cordycepin. Collectively, the results in this study provide direct evidence demonstrating the important neuroprotective effects of cordycepin against the hypoxic insult via improvement of the neuronal electrophysiological function, and the mechanism underlying the anti hypoxia-induced membrane depolarization is strongly recommended.

Cordycepin Decreases Compound Action Potential Conduction of Frog Sciatic Nerve In Vitro Involving Ca (2+) -Dependent Mechanisms.

Cordycepin has been widely used in oriental countries to maintain health and improve physical performance. Compound nerve action potential (CNAP), which is critical in signal conduction in the peripheral nervous system, is necessary to regulate physical performance, including motor system physiological and pathological processes. Therefore, regulatory effects of cordycepin on CNAP conduction should be elucidated. In this study, the conduction ability of CNAP in isolated frog sciatic nerves was investigated. Results revealed that cordycepin significantly decreased CNAP amplitude and conductive velocity in a reversible and concentration-dependent manner. At 50 mg/L cordycepin, CNAP amplitude and conductive velocity decreased by 62.18 ± 8.06% and 57.34% ± 6.14% compared with the control amplitude and conductive velocity, respectively. However, the depressive action of cordycepin on amplitude and conductive velocity was not observed in Ca(2+)-free medium or in the presence of Ca(2+) channel blockers (CdCl2/LaCl3). Pretreatment with L-type Ca(2+) channel antagonist (nifedipine/deltiazem) also blocked cordycepin-induced responses; by contrast, T-type and P-type Ca(2+) channel antagonists (Ni(2+)) failed to block such responses. Therefore, cordycepin decreased the conduction ability of CNAP in isolated frog sciatic nerves via L-type Ca(2+) channel-dependent mechanism.

Functions of nuclear receptor HR3 during larval-pupal molting in Leptinotarsa decemlineata (Say) revealed by in vivo RNA interference.

Our previous results revealed that RNA interference-aided knockdown of Leptinotarsa decemlineata FTZ-F1 (LdFTZ-F1) reduced 20E titer, and impaired pupation. In this study, we characterized a putative LdHR3 gene, an early-late 20E-response gene upstream of LdFTZ-F1. Within the first, second and third larval instars, three expression peaks of LdHR3 occurred just before the molt. In the fourth (final) larval instar 80 h after ecdysis and prepupal stage 3 days after burying into soil, two LdHR3 peaks occurred. The LdHR3 expression peaks coincide with the peaks of circulating 20E level. In vitro midgut culture and in vivo bioassay revealed that 20E and an ecdysteroid agonist halofenozide (Hal) enhanced LdHR3 expression in the final larval instars. Conversely, a decrease in 20E by feeding a double-stranded RNA (dsRNA) against an ecdysteroidogenesis gene Ldshd repressed the expression. Moreover, Hal rescued the transcript levels in the Ldshd-silenced larvae. Thus, 20E peaks activate the expression of LdHR3. Furthermore, ingesting dsRNA against LdHR3 successfully knocked down the target gene, and impaired pupation. Finally, knockdown of LdHR3 upregulated the transcription of three ecdysteroidogenesis genes (Ldphm, Lddib and Ldshd), increased 20E titer, and activated the expression of two 20E-response genes (LdEcR and LdFTZ-F1). Thus, LdHR3 functions in regulation of pupation in the Colorado potato beetle.

Involvement of a putative allatostatin in regulation of juvenile hormone titer and the larval development in Leptinotarsa decemlineata (Say).

Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis.

Involvement of FTZ-F1 in the regulation of pupation in Leptinotarsa decemlineata (Say).

During the final instar larvae of holometabolous insects, a pulse of 20-hydroxyecdysone (20E) and a drop in juvenile hormone (JH) trigger larval-pupal metamorphosis. In this study, two LdFTZ-F1 cDNAs (LdFTZ-F1-1 and LdFTZ-F1-2) were cloned in Leptinotarsa decemlineata. Both LdFTZ-F1-1 and LdFTZ-F1-2 were highly expressed just before or right after each molt, similar to the expression pattern of an ecdysteroidogenesis gene LdSHD. Ingestion of an ecdysteroid agonist halofenozide (Hal) enhanced LdFTZ-F1-1 and LdFTZ-F1-2 expression in the final larval instar. Conversely, a decrease in 20E by feeding a double-stranded RNA (dsRNA) against LdSHD repressed the expression. Moreover, Hal rescued the expression levels in LdSHD-silenced larvae. Thus, 20E peaks seem to induce the transcription of LdFTZ-F1s. Furthermore, ingesting dsLdFTZ-F1 from a common fragment of LdFTZ-F1-1 and LdFTZ-F1-2 successfully knocked down both LdFTZ-F1s, and impaired pupation. Finally, knocking down LdFTZ-F1s significantly repressed the transcription of three ecdysteroidogenesis genes, lowered 20E titer, and reduced the expression of two 20E receptor genes. Silencing LdFTZ-F1s also induced the expression of a JH biosynthesis gene, increased JH titer, but decreased the mRNA level of a JH early-inducible gene. Thus, LdFTZ-F1s are involved in the regulation of pupation by modulating 20E and JH titers and mediating their signaling pathways.

Response of the vacuolar ATPase subunit E to RNA interference and four chemical pesticides in Leptinotarsa decemlineata (Say).

Vacuolar-type H(+)-ATPases (vATPases) are localized in the apical membranes of nearly all epithelial tissues of insects, energize the membranes to absorb and/or secrete ions and fluids, and play essential roles in many physiological functions. Here we cloned and characterized a 1041-bp full-length vATPase subunit E cDNA (named as LdATPaseE) that encoded a 226-amino acid protein in Leptinotarsa decemlineata. LdATPaseE mRNA levels were constantly increased from egg to the third- and fourth-instar stages, dropped in wandering and pupal stages and were elevated again in the adult stage. It was highly expressed in ileum and rectum, moderately expressed in Malpighian tubules, midgut and foregut, and lowly expressed in fat body, ventral ganglion, epidermis and haemocytes in the fourth instars. After continuously ingested double-stranded RNAs originated from two LdATPaseE fragments LdATPaseE1 and LdATPaseE2, the target mRNA levels in the larvae were reduced by 85% and 55%, the larval growth and survival were significantly affected. Furthermore, topical application of fipronil, butane-fipronil, endosulfan and cypermethrin significantly upregulated LdATPaseE expression up to 8.3, 4.2, 2.8 and 6.2-fold 1 day after experiment, and up to 15.8, 3.4, 3.6 and 4.5-fold 2 days after treatment. It seems that depletion of vATPase subunit E is lethal, indicating that targeting vATPases by dsRNA appears a promising means of combating L. decemlineata. Moreover, vATPase subunit E is a pesticide inducible gene and may play a role in pesticide toxicity.

3-(9H-Fluoren-9-yl)-1,3-diphenyl-propan-1-one.

In the title compound, C(28)H(22)O, the fluorene ring system is approximately planar [maximum deviation = 0.044 (2) Å] and forms dihedral angles of 69.88 (6) and 89.46 (6)° with the phenyl rings. The crystal packing is stabilized by weak π-π stacking inter-actions, with centroid-centroid distances of 3.7172 (13) and 3.7827 (11) Å.

3-(9H-Fluoren-9-yl)-3-(4-methyl-phen-yl)-1-phenyl-propan-1-one.

In the title compound, C(29)H(24)O, the phenyl and methyl-phenyl rings are approximately perpendicular to each other, making a dihedral angle of 87.67 (10)°, and are oriented at dihedral angles of 62.49 (9) and 84.77 (7)°, respectively, to the nearly planar fluorene ring system [maximum deviation = 0.077 (2) Å] In the crystal, weak C-H⋯π inter-actions are observed.

Up-regulation of NDRG2 through nuclear factor-kappa B is required for Leydig cell apoptosis in both human and murine infertile testes.

Many pro-apoptotic factors, such as nuclear factor-kappa B (NF-κB) and Fas, play crucial roles in the process of Leydig cell apoptosis, ultimately leading to male sterility, such as in Sertoli cell only syndrome (SCO) and hypospermatogenesis. However, the molecular mechanism of such apoptosis is unclear. Recent reports on N-myc downstream-regulated gene 2 (ndrg2) have suggested that it is involved in cellular differentiation, development, and apoptosis. The unique expression of NDRG2 in SCO and hypospermatogenic testis suggests its pivotal role in those diseases. In this study, we analyzed NDRG2 expression profiles in the testes of normal spermatogenesis patients, hypospermatogenesis patients, and SCO patients, as well as in vivo and in vitro models, which were Sprague-Dawley rats and the Leydig cell line TM3 treated with the Leydig cell-specific toxicant ethane-dimethanesulfonate (EDS). Our data confirm that NDRG2 is normally exclusively located in the cytoplasm of Leydig cells and is up-regulated and translocates into the nucleus under apoptotic stimulations in human and murine testis. Meanwhile, transcription factor NF-κB was activated by EDS administration, bound to the ndrg2 promoter, and further increased in expression, effects that were abolished by NF-κB inhibitor Pyrrolidine dithiocarbamate (PDTC). Furthermore, siRNA knock-down of ndrg2 led to increased proliferative or decreased apoptotic TM3 cells, while over-expression of ndrg2 had the reverse effect. This study reveals that ndrg2 is a novel gene that participates in Leydig cell apoptosis, with essential functions in testicular cells, and suggests its possible role in apoptotic Leydig cells and male fertility.

Up-regulation of NDRG2 in senescent lens epithelial cells contributes to age-related cataract in human.

BACKGROUND: Human N-Myc downstream regulated gene2 (NDRG2), a novel gene has been cloned and shown to be related to a number of cellular processes, including proliferation, differentiation, stress, and apoptosis. NDRG2 has also been linked to age-related Alzheimer's disease. Since the role of this gene in senescence is limited, we have investigated the potential role of NDRG2 in human lens epithelial cells (HLECs), a paradigm implicated in age-related cataract. METHODOLOGY/PRINCIPAL FINDINGS: Cultured HLECs (SRA01/04) were subjected to prolonged exposure to low dose of H(2)O(2) to simulate senescence. After being exposed to 50 µM H(2)O(2) for 2 weeks, HLECs senescent-morphological changes appeared, cell viability decreased dramatically, cell proliferation reduced from 37.4% to 16.1%, and senescence-associated ß-galactosidase activity increased from 0 to 90.3%. Ndrg2 protein expression was also significantly increased in these senescent cells. To induce overexpression of NDRG2, SRA01/04 cells were infected with the adenoviral vector of NDRG2. In these cells, overexpression of NDRG2 resulted in a fibroblast-like appearance and the cell viability decreased about 20%. In addition, the NDRG2-overexpression cells demonstrated 20% lower viability when exposed to 50-200 µM H(2)O(2) for acute oxidative stress. Furthermore, the expression of NDRG2 from age-related cataracts was up-regulated 2-fold at both mRNA and protein levels compared with the clear lenses. CONCLUSIONS/SIGNIFICANCE: NDRG2 is up regulated not only in the ageing process of HLECs in vitro but also in the cells from human age-related cortical cataract in vivo. Up-regulation of NDRG2 induces cell morphological changes, reduces cell viability, and especially lowers cellular resistance to oxidative stress. NDRG2-mediated affects in HLECs may associate with age-related cataract formation.

Transient protection from heat-stress induced apoptotic stimulation by metastasis-associated protein 1 in pachytene spermatocytes.

BACKGROUND: Deregulated thermal factors have been frequently implicated in the pathogenesis of male infertility, but the molecular basis through which certain responses are directed remain largely unknown. We previously reported that overexpression of exogenous Metastasis-associated protein 1 (MTA1) protects spermatogenic tumor cells GC-2spd (ts) against heat-induced apoptosis. To further dissect the underlying mechanism, we addressed here the fine coordination between MTA1 and p53 in pachytene spermatocytes upon hyperthermal stimulation. METHODOLOGY/PRINCIPAL FINDINGS: High level of MTA1 expression sustained for 1.5 h in primary spermatocytes after heat stress before a notable decrease was detected conversely correlated to the gradual increase of acetylation status of p53 and of p21 level. Knockdown of the endogenous MTA1 in GC-2spd (ts) elevated the acetylation of p53 by diminishing the recruitment of HDAC2 and thereafter led to a dramatic increase of apoptosis after heat treatment. Consistent with this, in vivo interference of MTA1 expression in the testes of C57BL/6 mice also urged an impairment of the differentiation of spermatocytes and a disruption of Sertoli cell function due to the elevated apoptotic rate after heat stress. Finally, attenuated expression of MTA1 of pachytene spermatocytes was observed in arrested testes (at the round spermatid level) of human varicocele patients. CONCLUSIONS: These data underscore a transient protective effect of this histone modifier in primary spermatocytes against heat-stress, which may operate as a negative coregulator of p53 in maintenance of apoptotic balance during early phase after hyperthermal stress.