JMJD3 regulate H3K27me3 modification via interacting directly with TET1 to affect spermatogonia self-renewal and proliferation.

BACKGROUND: In epigenetic modification, histone modification and DNA methylation coordinate the regulation of spermatogonium. Not only can methylcytosine dioxygenase 1 (TET1) function as a DNA demethylase, converting 5-methylcytosine to 5-hydroxymethylcytosine, it can also form complexes with other proteins to regulate gene expression. H3K27me3, one of the common histone modifications, is involved in the regulation of stem cell maintenance and tumorigenesis by inhibiting gene transcription. METHODS: we examined JMJD3 at both mRNA and protein levels and performed Chip-seq sequencing of H3K27me3 in TET1 overexpressing cells to search for target genes and signaling pathways of its action. RESULTS: This study has found that JMJD3 plays a leading role in spermatogonia self-renewal and proliferation: at one extreme, the expression of the self-renewal gene GFRA1 and the proliferation-promoting gene PCNA was upregulated following the overexpression of JMJD3 in spermatogonia; at the other end of the spectrum, the expression of differentiation-promoting gene DAZL was down-regulated. Furthermore, the fact that TET1 and JMJD3 can form a protein complex to interact with H3K27me3 has also been fully proven. Then, through analyzing the sequencing results of CHIP-Seq, we found that TET1 targeted Pramel3 when it interacted with H3K27me3. Besides, TET1 overexpression not only reduced H3K27me3 deposition at Pramel3, but promoted its transcriptional activation as well, and the up-regulation of Pramel3 expression was verified in JMJD3-overexpressing spermatogonia. CONCLUSION: In summary, our study identified a novel link between TET1 and H3K27me3 and established a Tet1-JMJD3-H3K27me3-Pramel3 axis to regulate spermatogonia self-renewal and proliferation. Judging from the evidence offered above, we can safely conclude that this study provides new ideas for further research regarding the mechanism of spermatogenesis and spermatogenesis disorders on an apparent spectrum.

A Triply Linked Porphyrin-Norcorrole Hybrid with Singlet Diradical Character.

Norcorrole Ni(II) complexes have recently received considerable attention because they are readily accessible antiaromatic molecules. Their high stability under ambient conditions and ease of synthesis have enabled the exploration of the intrinsic properties of antiaromatic molecules. Here, we report the synthesis and properties of meso-meso singly linked porphyrin-norcorrole hybrids and a triply linked porphyrin-norcorrole hybrid. The singly linked and triply linked porphyrin-norcorrole hybrids were fully characterized, including an X-ray structural analysis. Due to their orthogonal conformation, the singly linked hybrids maintain the individual electronic properties of their porphyrin and norcorrole subunits, while the triply linked hybrid shows a significantly smaller electrochemical HOMO-LUMO gap (0.45 eV) than that of Ni(II) dimesitylnorcorrole (1.08 eV). Furthermore, the triply linked hybrid exhibits singlet diradical characteristics, as confirmed by VT NMR, ESR, and SQUID experiments.

Post-Installation of Fused Benzoheptagons at the Periphery of NiII Porphyrins: Helical Structures and Conformation-Adjustable Fullerenes Binding.

Fused-benzoheptagon-installed NiII porphyrins were synthesized by a protocol consisting of (2-formyl)arylation at the meso-position(s) of NiII porphyrins, conversion of formyl group to methoxyethene group by Wittig reaction, and final Bi(OTf)3 -catalyzed cyclization. The structures of these porphyrins have been revealed by X-ray analysis. Owing to the installed heptagon ring(s), these porphyrins show curved structures with conformational flexibility. Dimer has been shown to have a small activation barrier for inversion and to capture C60 and C70 with large association constants with adjustable conformational changes.

A Robust Porphyrin-Stabilized Triplet Carbon Diradical.

The synthesis of robust high-spin carbon radicals is an important topic in organic chemistry. Toward this end, several porphyrin-stabilized radicals have been systematically explored. A singly naphthalene-fused porphyrin radical was synthesized by a reaction sequence consisting of a Suzuki-Miyaura coupling of ß-borylated porphyrin with 2-bromobenzaldehyde, addition of mesityl Grignard reagent, intramolecular Friedel-Crafts alkylation, and final oxidation with DDQ or tBuOK/O2 . This strategy was also used to synthesize doubly naphthalene-fused porphyrins and syn- and anti-fused-anthracene-bridged porphyrin dimers. While singly naphthalene-fused porphyrin radical has been shown to be a stable monoradical, doubly naphthalene-fused porphyrins and anti-fused-anthracene-bridged porphyrin dimers have been shown to be closed-shell molecules. Finally, the syn-dimer was characterized as a surprisingly stable radical (t1/2 =28 days under ambient air and at 80 °C) that is storable for more than several months, despite its high-spin triplet ground-state carbon diradical.

Metabolic profiling reveals disorder of carbohydrate metabolism in mouse fibroblast cells induced by titanium dioxide nanoparticles.

As titanium dioxide (TiO(2)) nanoparticles are widely used commercially, their potential biosafety and metabolic mechanism needs to be fully explained. In this study, the cytotoxicity of homogeneous and weakly aggregated (< 100 nm) TiO(2) nanoparticles was investigated by analyzing the changes in metabolite profiles both in mouse fibroblast (L929) cells and their corresponding culture media using gas chromatograph with a time-of-flight mass spectrometry (GC/TOFMS)-based metabolomic strategy. With multivariate statistics analysis, satisfactory separations were observed in principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) models. Based on the variable importance in the OPLS-DA models, a series of differential metabolites were identified by comparison between TiO(2) nanoparticle-treated L929 cells or their corresponding culture media and the control groups. It was found that the major biochemical metabolism (carbohydrate metabolism) was suppressed in TiO(2) nanoparticle-treated L929 cells and their corresponding culture media. These results might account for the serious damage to energy metabolism in mitochondria and the increased cellular oxidation stress in TiO(2) nanoparticle-induced L929 cells. These results also suggest that the metabolomic strategy had a great potential in evaluating the cytotoxicity of TiO(2) nanoparticles and thus was very helpful in understanding its underlying molecular mechanisms.

Synthesis of Naphthalene- and Phenanthrene-Fused Smaragdyrins and Their BF2 Complexes.

Naphthalene- and phenanthrene-fused [22]smaragdyrin BF2 -complexes were synthesized by 1) Suzuki-Miyaura coupling of ß-brominated [22]smaragdyrin BF2 complexes with 2-formylarylboronates, 2) Witting-type methoxymethylenation of the formyl group, and 3) methanesulfonic acid-catalyzed cyclization reaction. Subsequently these BF2 complexes were deboronized and oxidized to the corresponding antiaromatic [20]smaragdyrin free bases. The installed fused structures led to decrease of the aromatic characters of the [22]smaragdyrin BF2 complexes and the antiaromatic characters of the [20]smaragdyrin free bases.

Prevalence and Novel Genotypes Identification of Enterocytozoon bieneusi in Dairy Cattle in Yunnan Province, China.

Enterocytozoon bieneusi is a fungus-like protist parasite that can cause diarrhea and enteric diseases. The infection of E. bieneusi has been reported in many host species, including cattle and humans. However, information on prevalence and genotype distribution of E. bieneusi in dairy cattle in Yunnan province in China is still absent. In this study, 490 Holstein Cows and 351 dairy buffalo fecal samples were collected from three regions in Yunnan province, China. By using nest-PCR that targets the internal transcribed spacer (ITS), we found that the prevalence of E. bieneusi was 0.59% (5/841). DNA sequence analysis showed that five E. bieneusi genotypes were identified in this study, including two novel genotypes, YNDCEB-90 and YNDCEB-174, and three known genotypes (I, J, BEB4). Phylogenetic analysis revealed that two novel genotypes, YNDCEB-90 and YNDCEB-174, were clustered into Group 1, representing the zoonotic potential. The remaining genotypes I, J, and BEB4, which are the most frequent genotypes of E. bieneusi infection in cattle and lead to E. bieneusi infection in humans, belonged to Group 2. Although the lower prevalence of E. bieneusi was detected in dairy cattle in Yunnan province, it indicates that dairy cattle should be considered to be one of the potential hosts for transmitting E. bieneusi to humans. These findings are important for the development of effective prevention strategies for microsporidiosis.

Pd-Catalyzed Cross Coupling Strategy for Functional Porphyrin Arrays.

Porphyrin arrays are an important class of compounds to study interporphyrin electronic interactions that are crucial in determining the rates of energy transfer and electron transfer reactions. When the electronic interactions become stronger, porphyrin arrays exhibit significantly altered optical and electronic properties owing to large oscillator strength and flexible electronic nature of porphyrins. In addition, porphyrins accept various metal cation in their cavities and the interporphyrin interactions depend upon the coordinated metal. With these in the background, porphyrin arrays have been extensively explored as sensors, multielectron catalysts, photodynamic therapy reagents, artificial photosynthetic antenna, nonlinear optical materials, and so on. Here, we review the synthesis of porphyrin arrays by palladium-catalyzed cross-coupling reactions, which are quite effective to construct carbon-carbon bonds and carbon-nitrogen bonds in porphyrin substrates. Palladium-catalyzed cross coupling reactions employed so far are Suzuki-Miyaura coupling reaction, Sonogashira coupling reaction, Buchwald-Hartwig amination, Mizoroki-Heck reaction, Migita-Kosugi-Stille coupling reaction, and so on. In each case, the representative examples and synthetic advantages are discussed.

MHC-DRB1 exon 2 polymorphism and its association with mycoplasma ovipneumonia resistance or susceptibility genotypes in sheep.

Major histocompatibility complex (MHC) polymorphisms are associated with animal and human diseases. However, only a few studies have reported an association between MHC polymorphisms and mycoplasma ovipneumonia (MO). In the present study, three resistance/susceptibility genotypes associated with MO were identified by polymerase chain reaction-restriction fragment length polymorphism genotyping, assessing the clinical and pathological features, and examining the immune factors. The current results showed that MvaI bb and HaeIII ee were dominant genotypes in the susceptible Hu population, while MO-resistant populations, Dorper and D 9 H hybrids, were dominated by the MvaI cc and HaeIII dd genotypes, suggesting that MvaI cc and HaeIII dd genotypes might be associated with the trait of MO resistance. Further, the clinical symptoms and pathological morphology in the susceptibility group infected with MO were more severe than those in the resistant groups infected similarly. The data on the changes in the immune factor responses were utilized to deduce the molecular mechanism underlying the MO resistance/susceptibility. The results showed that the susceptible genotypes promote the inflammatory responses by inducing a high expression of TNFa, IFNc, IL-4, IL-6, and IL-1b, while the resistant genotypes inhibit the inflammatory response by increasing the expression of IL-2 and IL-10 significantly. This finding would provide the theoretical guidance for propagating sheep breeds that are highly resistant to MO.

The Use of RNAi Technology to Interfere with Zfx Gene Increases the Male Rates of Red Deer (Cervus elaphus) Offspring.

Zinc finger protein X-linked (Zfx) was regarded to be a sex determination factor and plays a critical role in spermatogenesis. RNAi is an effective method of silencing Zfx mRNA expression. However, there has been little research on the use of RNAi technology to control the sex of the offspring of red deer (Cervus elaphus). The objective of this study was first to explore an efficient method to alter the red deer offspring sex-ratio by silencing the gene Zfx during spermatogenesis. Three recombinant expression vectors pLL3.7/A, pLL3.7/B, and pLL3.7/C were constructed to interrupt the Zfx gene. The results showed that the expression of Zfx mRNA was significantly silenced by pLL3.7/A (P < 0.01), compared with the control group. The group injected with pLL3.7/A produced 94 red deer, including 68 males and 26 females. The male rates (72.34%) were significantly higher than the control groups (P < 0.01). Our result suggests that Zfx siRNA is a useful approach to control offspring sex in red deer. This study further confirms that the Zfx gene plays a significant role in the process of X spermatogenesis.

Chemical properties of heavy metals in typical hospital waste incinerator ashes in China.

Incineration has become the main mechanism for hospital waste (HW) disposal in China after the outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003. However, little information is available on the chemical properties of the resulting ashes. In the present study, 22HW ash samples, including 14 samples of bottom ash and eight samples of fly ash, were collected from four typical HW incineration plants located across China. Chemical analysis indicated that the HW ashes contained large amounts of metal salts of Al, Ca, Fe, K, Mg, Na with a concentration range of 1.8-315gkg(-1). Furthermore, the ashes contained high concentrations of heavy metals such as Ag, As, Ba, Bi, Cd, Cr, Cu, Mn, Ni, Pb, Ti, Sb, Sn, Sr, Zn with a vast range of 1.1-121,411mgkg(-1), with higher concentrations found in the fly ash samples. Sequential extraction results showed that Ba, Cr, Ni and Sn are present in the residual fraction, while Cd existed in the exchangeable and carbonate fractions. As, Mn, Zn existed in the Fe-Mn oxide fraction, Pb was present in the Fe-Mn oxide and residual fractions, and Cu was present in the organic matter fraction. Furthermore, toxicity characteristic leaching procedure (TCLP) results indicated that leached amounts of Cd, Cu and Pb from almost all fly ash samples exceeded the USEPA regulated levels. A comparison between the HW ashes and municipal solid waste (MSW) ash showed that both HW bottom ash and fly ash contained higher concentrations of Ag, As, Bi, Cd, Cr, Cu, Pb, Ti, and Zn. This research provides critical information for appropriate HW incineration ash management plans.

Carbazole-containing porphyrinoid and its oligomers.

A novel carbazole-containing porphyrinoid 4H and its oligomers 6H and 7H were synthesized for the first time via the Suzuki-Miyaura cross-coupling reaction. The structures of 4H, 4Pd, 6H, and 6Zn were finally confirmed by X-ray analysis. The exciton coupling strength (628 cm-1) in 4Zn, 6Zn, and 7Zn was found to be larger than that of the directly-linked porphyrin arrays (570 cm-1), extending their absorption spectra to the NIR region as well as enhancing the extinction coefficients.

Outer Membrane Protein 25 of Brucella Activates Mitogen-Activated Protein Kinase Signal Pathway in Human Trophoblast Cells.

Outer membrane protein 25 (OMP25), a virulence factor from Brucella, plays an important role in maintaining the structural stability of Brucella. Mitogen-activated protein kinase (MAPK) signal pathway widely exists in eukaryotic cells. In this study, human trophoblast cell line HPT-8 and BALB/c mice were infected with Brucella abortus 2308 strain (S2308) and 2308ΔOmp25 mutant strain. The expression of cytokines and activation of MAPK signal pathway were detected. We found that the expressions of tumor necrosis factor-α, interleukin-1, and interleukin-10 (IL-10) were increased in HPT-8 cells infected with S2308 and 2308ΔOmp25 mutant. S2308 also activated p38 phosphorylation protein, extracellular-regulated protein kinases (ERK), and Jun-N-terminal kinase (JNK) from MAPK signal pathway. 2308ΔOmp25 could not activate p38, ERK, and JNK branches. Immunohistochemistry experiments showed that S2308 was able to activate phosphorylation of p38 and ERK in BABL/c mice. However, 2308ΔOmp25 could weakly activate phosphorylation of p38 and ERK. These results suggest that Omp25 played an important role in the process of Brucella activation of the MAPK signal pathway.

Building online brand perceptual map.

Many companies have launched their products or services online as a new business focus, but only a few of them have survived the competition and made profits. The most important key to an online business's success is to create "brand value" for the customers. Although the concept of online brand has been discussed in previous studies, there is no empirical study on the measurement of online branding. As Web 2.0 emerges to be critical to online branding, the purpose of this study was to measure Taiwan's major Web sites with a number of personality traits to build a perceptual map for online brands. A pretest identified 10 most representative online brand perceptions. The results of the correspondence analysis showed five groups in the perceptual map. This study provided a practical view of the associations and similarities among online brands for potential alliance or branding strategies. The findings also suggested that brand perceptions can be used with identified consumer needs and behaviors to better position online services. The brand perception map in the study also contributed to a better understanding of the online brands in Taiwan.