Decabromodiphenyl ether induces the chromosome association disorders of spermatocytes and deformation failures of spermatids in mice.

The environmental presence of decabromodiphenyl ether (BDE-209), which is toxic to the male reproductive system, is widespread. The current study investigated its mechanism of toxicity in mice. The results showed, that BDE-209 induced DNA damage, decreased the expression of the promoter of meiosis spermatogenesis- and oogenesis-specific basic helix-loop-helix 1 (Sohlh1), meiosis related-factors Lethal (3) malignant brain tumor like 2 (L3MBTL2), PIWI-like protein 2 (MILI), Cyclin-dependent kinase 2 (CDK2), Cyclin A, synaptonemal complex protein 1 (SYCP1) and synaptonemal complex protein 3 (SYCP3), and caused spermatogenic cell apoptosis, resulting in a decrease in sperm quantity and quality. Furthermore, BDE-209 downregulated the levels of anaphase-promoting complex/cyclosome (APC/C), increased the expression of PIWI-like protein 1 (MIWI) in the cytoplasm of elongating spermatids, and decreased the nuclear levels of RING finger protein 8 (RNF8), ubiquitinated (ub)-H2A/ub-H2B, and Protamine 1 (PRM1)/Protamine 2 (PRM2), while increasing H2A/H2B nuclear levels in spermatids. The reproductive toxicity was persistent for 50 days following the withdrawal of BDE-209 exposure. The results suggested that BDE-209 inhibits the initiation of meiosis by decreasing the expression of Sohlh1. Furthermore, the reduced expression of L3MBTL2 inhibited the formation of chromosomal synaptonemal complexes by depressing the expression of meiosis regulators affecting the meiotic progression and also inhibited histone ubiquitination preventing the replacement of histones by protamines, by preventing RNF8 from entering nuclei, which affected the evolution of spermatids into mature sperm.

Proteomic characteristics of plasma and blood cells in natural aging rhesus monkeys.

Aging has become a serious social issue that places a heavy burden on society. However, the underlying mechanisms of aging remain unclear. This study sought to understand the aging process as it may be affected by proteins in the blood, the most important functional system for material transportation in the body. We analyzed and compared the protein expression spectrums in the blood of old and young rhesus monkeys and found 257 proteins expressed differentially in plasma and 1183 proteins expressed differentially in blood cells. Through bioinformatics analysis, we found that the differentially-expressed proteins in plasma were involved in signal pathways related to complement and coagulation cascades, pertussis, malaria, phagosome, and cholesterol metabolism, while the differentially-expressed proteins in blood cells were involved in endocytosis, proteasome, ribosome, protein processing in the endoplasmic reticulum, and Parkinson's disease. We confirmed that the protein levels of complement C2 in plasma and actin-related protein 2/3 complex subunit 2 (ARPC2) in blood cells obviously decreased, whereas the complement C3 and complement component 4 binding protein beta (C4BPB) significantly increased in plasma of old rhesus monkeys and C57BL/6 mice. Our results suggest that C2, C3, C4BPB, and ARPC2 can be used as target proteins for anti-aging research.

Harm of circadian misalignment to the hearts of the adolescent wistar rats.

PURPOSE: The purpose of this study was to observe the harm of circadian misalignment (CM), caused by an inverted photoperiod (IP), on the hearts of the adolescent Wistar rats, and to explore the mechanisms leading to harm. METHODS: An IP was used to create a CM model. A total of 174 Wistar rats were randomly divided into circadian alignment (CA) and CM groups (87 rats per group). The different activity rhythms of the two groups of rats were adjusted through different light/dark cycles for 90 days. We recorded the rhythmic activity trajectory and sleep time of the rats. After 90 days of modeling, we performed various analyses (i.e., blood pressure, weight, cardiac ultrasound tests, serological tests, cardiac tissue immunofluorescence, immunohistochemistry, transmission electron microscopy on myocardial mitochondria, western blotting, and quantitative polymerase chain reactions). RESULTS: (1) The IP protocol caused CM in rats. (2) CM rats showed significantly higher blood pressure during the day (resting phase). They also showed significantly higher serum levels of angiotensin II and epinephrine during the day compared to the CA rats. (3) CM caused up-regulation of gene expression of adrenergic receptors α1 (α1-AR) and ß1 (ß1-AR) and down-regulation of the glucocorticoid receptor (Gr) gene expression in rat hearts. It also caused downregulation of Bmal1 expression. In addition, the changes in Bmal1 and Per2 correlated with the changes in ß1-AR and α1-AR. (4) CM had adverse effects on multiple molecular proteins of the heart. (5) CM increased the collagen fibers in the rat heart and increased the destruction of mitochondria. (6) Eventually, CM caused a decrease in the pumping function of the heart and decreased the coronary blood flow rate. CONCLUSIONS: (1) CM significantly affected the cardiac structure and function in the adolescent rats through a variety of mechanisms. (2) CM can regulate the expression of myocardial clock genes, and it is likely to have an impact on the heart through this pathway.

Keap1 as Target of Genistein on Nrf2 Signaling Pathway Antagonizing Aß induced Oxidative Damage of Cerebrovascular Endothelial Cells.

BACKGROUND: ß-amyloid peptides (Aß) induced oxidative damage contributes to the pathogenesis of neurodegenerative diseases, and the cerebrovascular system is more vulnerable to oxidative stress. Our earlier study showed a clue that Genistein (Gen) might activate the Nf-E2 related factor 2 (Nrf2) pathway to protect cerebrovascular cells from oxidative damage induced by Aß, but the specific mechanisms and regulation targets are unclear. OBJECTIVE: In this study, the anti-oxidative effects and the possible targets of Gen on regulating the Nrf2 pathway in bEnd.3 cells were investigated. Cells were divided into control, Aß25-35, Gen, and Gen+Aß25-35 groups. METHODS: Cell viability, levels of malondialdehyde (MDA), Superoxide Dismutase (SOD) activity, and nitrotyrosine were evaluated. Moreover, mRNA and/or protein expressions of Nrf2 and kelchlike ECH-associated protein 1 (Keap1) were measured. Then we transfected Keap1 over-expressed plasmid into bEnd.3 cells and measured the protein expressions of Nrf2 pathway related factors. RESULTS: Data showed that Gen could inhibit the over-production of MDA and nitrotyrosine and activate SOD activity. Furthermore, we discovered that Gen could up-regulate Nrf2 mRNA and protein expression while down-regulating Keap1 protein expression. The Keap1 over-expressed plasmid study revealed that the up-regulation of Nrf2 protein expression induced by Gen pretreatment could be blocked by transfection of Keap1 over-expressed plasmid, and the same results were observed in Nrf2 downstream factors. CONCLUSION: Gen could alleviate the cerebrovascular cells' oxidative damage induced by Aß25-35 by regulating the Nrf2 pathway, and Keap1 might be one of the targets of Gen in activating the Nrf2 pathway.

Effects of inverted photoperiods on the blood pressure and carotid artery of spontaneously hypertensive rats and Wistar-Kyoto rats.

OBJECTIVE: The objective of this study was to investigate the effects of inverted photoperiods on the blood pressure and carotid arteries in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats (homologous control group). METHODS AND RESULTS: This study used two inverted photoperiods [inverted light:dark (ILD)16 : 8 and ILD12 : 12] to create the model. A total of 27 male SHR and 27 male WKY rats were randomly divided into six groups (nine rats per group): SHR (LD12 : 12), SHR (ILD16 : 8), SHR (ILD12 : 12), WKY (LD12 : 12), WKY (ILD16 : 8) and WKY (ILD12 : 12). We recorded the trajectory of the activity rhythm of the rats and performed carotid vascular ultrasound examination, MRI (arterial spin labelling) analysis and carotid biopsy. The results showed that inverted photoperiods increased the blood pressure, carotid intima-media thickness, resistance index and blood flow velocity. In addition, inverted photoperiods led to the development of carotid arterial thrombosis, significantly reduced cerebral blood flow and increased the number of collagen fibres. Moreover, it increased the expression of angiotensin receptor and low-density lipoprotein receptor in the carotid arteries, leading to decreased expression of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase and nitric oxide synthase. Inverted photoperiods induced the formation of atherosclerotic plaque. Multiple results of SHR were worse than those of WKY rats. CONCLUSION: Taken together, inverted photoperiods can produce a series of adverse consequences on blood pressure and carotid arteries. Hypertension can aggravate the adverse effects of inverted photoperiods.

Effect of ovarian storage time at 4 degrees C on cumulus cell apoptosis in porcine antral follicles.

The present study was conducted to investigate the effect of cold storage time on apoptosis of cumulus cells (CCs) from porcine ovaries, and to compare the sensitivity of four apoptosis-detection methods. Porcine ovaries were stored in physiological saline solution at 4°C for 0, 7, 24 and 48 hr, and then cumulus cells or granulosa cells (GCs) in antral follicles were retrieved to detect cell apoptosis. Cumulus cells isolated from stored ovaries for 24 hr presented obvious apoptosis using terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP nick end-labeling (TUNEL) assay. A typical DNA ladder pattern of apoptosis was observed in GCs 24 hr post storage treatment. The mean Olive Tail Moment of CCs was significantly increased after 24 hr using comet assay; however, the mean tail migration and mean tail DNA increased gradually after 7 hr of storage. In addition, annexin V/PI staining assay showed an obvious increase in apoptotic CCs (Annexin V positive, PI negative) 7 hr after treatment, and the apoptotic rate reached to a peak at 24 hr followed by a decline after 48 hr of storage to the level at 7 hr. In conclusion, cold storage of porcine ovary in physiological saline solution induced a time-dependent increase in apoptosis of cumulus cells, and annexin V/PI staining combined with comet assay provided a sensitive and reliable method to detect early damages in cumulus cells induced by cold storage of ovary.

Effects of circadian rhythm disorder on the hippocampus of SHR and WKY rats.

The present study investigated the effects of circadian rhythm disorder (CRD) on the hippocampus of SHR and WKY rats. Male SHR rats (n = 27) and WKY rats (n = 27) were randomly divided into six groups: SHR and WKY normal (N)CR, SHR and WKY CRD 16/8 (CRD16/8), and SHR and WKY CRD 12/12 (CRD12/12). Activity patterns were adjusted using different photoperiods over 90 days and any changes were recorded. Rats were tested in the Morris water maze and in a novel object recognition experiment; serologic analysis, magnetic resonance imaging (diffusion tensor imaging + arterial spin labeling), hippocampal Nissl staining, Fluoro-Jade B staining, and immunohistochemistry were also performed. The results showed that both types of inverted photoperiod reduced CR amplitude and prolonged the circadian period. CRD and hypertension reduced memory performance and novel object recognition and preference. The decreases in memory and preference indices were greater in rats in the CRD12/12 group compared to the CRD16/8 group. CRD and hypertension decreased fractional anisotropy values, the number of neurons and astrocytes in the hippocampus, and the expression of brain-derived neurotrophic factor and synapsin 1; it also enhanced the degeneration of neurons and microglia and reduced blood flow in the hippocampus, and increased nuclear factor κB, caspase, neuron-specific enolase, and interleukin-6 levels. These findings reveal a biological basis for the link between CRD and cognitive decline, which has implications for CRD caused by shift work and other factors.

Kinetics of the accumulation of group 2 innate lymphoid cells in IL-33-induced and IL-25-induced murine models of asthma: a potential role for the chemokine CXCL16.

ILC2s are implicated in asthma pathogenesis, but little is known about the mechanisms underlying their accumulation in airways. We investigated the time course of ILC2 accumulation in different tissues in murine models of asthma induced by a serial per-nasal challenge with ovalbumin (OVA), house dust mice (HDM), IL-25 and IL-33 and explored the potential roles of ILC2-attracting chemokines in this phenomenon. Flow cytometry was used to enumerate ILC2s at various time points. The effects of cytokines and chemokines on ILC2 migration were measured in vitro using a chemotaxis assay and in vivo using small animal imaging. Compared with saline and OVA challenge, both IL-25 and IL-33 challenge alone induced significant accumulation of ILC2s in the mediastinal lymph nodes, lung tissue and bronchoalveolar lavage fluid of challenged animals, but with a distinct potency and kinetics. In vitro, IL-33 and CXCL16, but not IL-25 or CCL25, directly induced ILC2 migration. Small animal in vivo imaging further confirmed that a single intranasal provocation with IL-33 or CXCL16 was sufficient to induce the accumulation of ILC2s in the lungs following injection via the tail vein. Moreover, IL-33-induced ILC2 migration involved the activation of ERK1/2, p38, Akt, JNK and NF-κB, while CXCL16-induced ILC2 migration involved the activation of ERK1/2, p38 and Akt. These data support the hypothesis that epithelium-derived IL-25 and IL-33 induce lung accumulation of ILC2s, while IL-33 exerts a direct chemotactic effect in this process. Although ILC2s express the chemokine receptors CXCR6 and CCR9, only CXCL16, the ligand of CXCR6, exhibits a direct chemoattractant effect.

Angiotensin II Regulates Th1 T Cell Differentiation Through Angiotensin II Type 1 Receptor-PKA-Mediated Activation of Proteasome.

BACKGROUND/AIMS: Naive CD4+ T cells differentiate into T helper cells (Th1 and Th2) that play an essential role in the cardiovascular diseases. However, the molecular mechanism by which angiotensin II (Ang II) promotes Th1 differentiation remains unclear. The aim of this study was to determine whether the Ang II-induced Th1 differentiation regulated by ubiquitin-proteasome system (UPS). METHODS: Jurkat cells were treated with Ang II (100 nM) in the presence or absence of different inhibitors. The gene mRNA levels were detected by real-time quantitative PCR analysis. The protein levels were measured by ELISA assay or Western blot analysis, respectively. RESULTS: Ang II treatment significantly induced a shift from Th0 to Th1 cell differentiation, which was markedly blocked by angiotensin II type 1 receptor (AT1R) inhibitor Losartan (LST). Moreover, Ang II significantly increased the activities and the expression of proteasome catalytic subunits (ß1, ß1i, ß2i and ß5i) in a dose- and time-dependent manner. However, Ang II-induced proteasome activities were remarkably abrogated by LST and PKA inhibitor H-89. Mechanistically, Ang II-induced Th1 differentiation was at least in part through proteasome-mediated degradation of IκBα and MKP-1 and activation of STAT1 and NF-κB. CONCLUSIONS: This study for the first time demonstrates that Ang II activates AT1R-PKA-proteasome pathway, which promotes degradation of IκBα and MKP-1 and activation of STAT1 and NF-κB thereby leading to Th1 differentiation. Thus, inhibition of proteasome activation might be a potential therapeutic target for Th1-mediated diseases.

Bacterial magnetic particles improve testes-mediated transgene efficiency in mice.

Nano-scaled materials have been proved to be ideal DNA carriers for transgene. Bacterial magnetic particles (BMPs) help to reduce the toxicity of polyethylenimine (PEI), an efficient gene-transferring agent, and assist tissue transgene ex vivo. Here, the effectiveness of the BMP-PEI complex-conjugated foreign DNAs (BPDs) in promoting testes-mediated gene transfer (TMGT) in mouse was compared with that of liposome-conjugated foreign DNAs. The results proved that through testes injection, the clusters of BPDs successfully reached the cytoplasm and the nuclear of spermatogenesis cell, and expressed in testes of transgene founder mice. Additionally, the ratio of founder mice obtained from BPDs (88%) is about 3 times higher than the control (25%) (p < 0.05). Interestingly, the motility of sperms recovered from epididymis of the founder mice from BPD group were significantly improved, as compared with the control (p < 0.01). Based on classic breeding, the ratio of transgene mice within the first filial was significantly higher in BPDs compared with the control (73.8% versus 11.6%, p < 0.05). TMGT in this study did not produce visible histological changes in the testis. In conclusion, nano-scaled BPDs could be an alternative strategy for efficiently producing transgene mice in vivo.

[Establishment of a complete daily time series of precipitation and its change characteristics in forest region of eastern China during 1961-2010].

To accurately interpolate the missing precipitation data from meteorological observation stations within a region to obtain a complete precipitation series is of significance in improving the spatial and temporal resolution in analyzing the effects of climate change. By using spatial correlation and stepwise regression techniques, this paper interpolated the missing precipitation data for an individual day or less than 7 days in a month from the 853 meteorological stations in the forest region of Eastern China in 1961-2010, as a consequent establishment of the complete time series precipitation datasets of the observation stations in 1961-2010 established. Based on these, trend analysis approach was applied to analyze the variation characteristics of the annual precipitation, annual precipitation days, and extreme precipitation events in the region in 1961-2010. During the study period, the annual precipitation in the region presented an insignificant increasing trend, with a tendency of 5.58 mm (10 a) -1, but the decadal variation was obvious. The annual precipitation days reduced significantly, while the annual extreme precipitation days and extreme precipitation volumes increased significantly, with a tendency of 0.12 d (10 a) -1 and 10. 22 mm (10 a)-1, respectively. Since the 1990s, the extreme precipitation events became frequently and intensively, and the proportion of the volumes of extreme precipitation to total precipitation increased significantly. Both the extreme precipitation days and the volumes of extreme precipitation had an abrupt change in 1993.