Insights into the interaction between carbamazepine and natural dissolved organic matter in the Yangtze Estuary using fluorescence excitation-emission matrix spectra coupled with parallel factor analysis

The interaction between carbamazepine (CBZ) and dissolved organic matter (DOM) from three zones (the nearshore, the river channel, and the coastal areas) in the Yangtze Estuary was investigated using fluorescence quenching titration combined with excitation emission matrix spectra and parallel factor analysis (PARAFAC). The complexation between CBZ and DOM was demonstrated by the increase in hydrogen bonding and the disappearance of the C=O stretch obtained from the Fourier transform infrared spectroscopy analysis. The results indicated that two protein-like substances (component 2 and component3) and two humic-like substances (component 1 and 4) were identified in the DOM from the Yangtze Estuary. The fluorescence quenching curves of each component with the addition of CBZ and the Ryan and Weber model calculation results both demonstrated that the different components exhibited different complexation activities with CBZ. The protein-like components had a stronger affinity with CBZ than did the humic-like substances. On the other hand, the autochthonous tyrosine-like C2 played an important role in the complexation with DOM from the river channel and coastal areas, while C3 influenced by anthropogenic activities showed an obvious effect in the nearshore area. DOMs from the river channel have the highest binding capacity for CBZ, which may ascribe to the relatively high phenol content group in the DOM.

Organic acid compounds in root exudation of Moso Bamboo (Phyllostachys pubescens) and its bioactivity as affected by heavy metals

Moso bamboo (Phyllostachys pubescens) has great potential as phytoremediation material in soil contaminated by heavy metals. A hydroponics experiment was conducted to determine organic acid compounds of root exudates of lead- (Pb), zinc- (Zn), copper- (Cu), and cadmium (Cd)-tolerant of Moso bamboo. Plants were grown in nutrients solution which included Pb, Zn, Cu, and Cd applied as Pb(NO₃)₂ (200 μM), ZnSO₄·7H₂O (100 μM), CuSO₄·5H₂O (25 μM), and CdCl₂ (10 μM), respectively. Oxalic acid and malic acid were detected in all treatments. Lactic acid was observed in Cu, Cd, and control treatments. The oxalic was the main organic acid exudated by Moso bamboo. In the sand culture experiment, the Moso bamboo significantly activated carbonate heavy metals under activation of roots. The concentration of water-soluble metals (except Pb) in sand were significantly increased as compared with control. Organic acids (1 mM mixed) were used due to its effect on the soil adsorption of heavy metals. After adding mixed organic acids, the Cu and Zn sorption capacity in soils was decreased markedly compared with enhanced Pb and Cd sorption capacity in soils. The sorption was analyzed using Langmuir and Freundlich equations with R ² values that ranged from 0.956 to 0.999 and 0.919 to 0.997, respectively.

Adoptive Transfer of Tracer-Alloreactive CD4+ T Cell Receptor Transgenic T Cells Alters the Endogenous Immune Response to an Allograft

T cell receptor transgenic (TCR-Tg) T cells are often used as tracer populations of antigen-specific responses to extrapolate findings to endogenous T cells. The extent to which TCR-Tg T cells behave purely as tracer cells or modify the endogenous immune response is not clear. To test the impact of TCR-Tg T cell transfer on endogenous alloimmunity, recipient mice were seeded with CD4⁺ or CD8⁺ TCR-Tg or polyclonal T cells at the time of cardiac allograft transplantation. Only CD4⁺ TCR-Tg T cells accelerated rejection and, unexpectedly, led to a dose-dependent decrease in both transferred and endogenous T cells infiltrating the graft. In contrast, recipients of CD4⁺ TCR-Tg T cells exhibited enhanced endogenous donor-specific CD8⁺ T cell activation in the spleen and accelerated alloantibody production. Introduction of CD4⁺ TCR-Tg T cells also perturbed the intragraft accumulation of innate cell populations. Transferred CD4⁺ TCR-Tg T cells alter many aspects of endogenous alloimmunity, suggesting that caution should be used when interpreting experiments using these adoptively transferred cells because the overall nature of allograft rejection may be altered. These results also may have implications for adoptive CD4⁺ T cell immunotherapy in tumor and infectious clinical settings because cell infusion may have additional effects on natural immune responses.

[Upregulated PD-1 on CD8+T cells is positively correlated with activation of T cells during HIV-1 infection]

Objective To investigate the expressions of programmed death-1 (PD-1), CD38, human leukocyte antigen DR (HLA-DR) and anligen KI-67(ki67) on CD8⁺ T cells, and the correlation between PD-1/PD-L1 pathway and activation, immunodepletion during HIV-1 infection. Methods Peripheral blood mononuclear cells were isolated by density gradient centrifugation from 87 HIV-1 patients and 22 healthy controls. The expression levels of PD-1, CD38, HLA-DR and ki67 on CD8⁺T cells were detected by flow cytometry. Furthermore, we evaluated the production of interferon-γ (IFN-γ) and tumor necrosis factor α (TNF-α) in CD8⁺ T cells by blocking PD-1/PD-L1 pathway in the presence of PD-L1 mAb. Results Compared with healthy controls, HIV-1 infection resulted in a significant increase in PD-1 expression on CD8⁺T cells. Correlation analysis showed that PD-1 expression on CD8⁺T cell was positively associated with HIV-1 viral loading (VL) and negatively associated with the number of CD4⁺T cells. Furthermore, PD-1 expression was positively correlated with CD38 and HLA-DR expressions on CD8⁺T cells in HIV-1 infected patients. There was no association between PD-1 and ki67 expression on CD8⁺T cells in HIV-1 infected patients. Blockage of the PD-1/PD-L1 pathway increased TNF-α and IFN-γ production in CD8⁺T cells. Conclusion PD-1 expression on CD8⁺T cells is significantly upregulated during HIV-1 infection. PD-1 expression is correlated with CD8⁺T cell inhibition, immunodepletion and disease progression. Moreover, the blockage of PD-1/PD-L1 pathway can restore the function of CD8⁺T cells in HIV-1 patients.

Tracking of TCR-Transgenic T Cells Reveals That Multiple Mechanisms Maintain Cardiac Transplant Tolerance in Mice

Solid organ transplantation tolerance can be achieved following select transient immunosuppressive regimens that result in long-lasting restraint of alloimmunity without affecting responses to other antigens. Transplantation tolerance has been observed in animal models following costimulation or coreceptor blockade therapies, and in a subset of patients through induction protocols that include donor bone marrow transplantation, or following withdrawal of immunosuppression. Previous data from our lab and others have shown that proinflammatory interventions that successfully prevent the induction of transplantation tolerance in mice often fail to break tolerance once it has been stably established. This suggests that established tolerance acquires resilience to proinflammatory insults, and prompted us to investigate the mechanisms that maintain a stable state of robust tolerance. Our results demonstrate that only a triple intervention of depleting CD25⁺ regulatory T cells (Tregs), blocking programmed death ligand-1 (PD-L1) signals, and transferring low numbers of alloreactive T cells was sufficient to break established tolerance. We infer from these observations that Tregs and PD-1/PD-L1 signals cooperate to preserve a low alloreactive T cell frequency to maintain tolerance. Thus, therapeutic protocols designed to induce multiple parallel mechanisms of peripheral tolerance may be necessary to achieve robust transplantation tolerance capable of maintaining one allograft for life in the clinic.

Regulation of Neurospora Catalase-3 by global heterochromatin formation and its proximal heterochromatin region

Catalase-3 (CAT-3) constitutes the main catalase activity in growing hyphae of Neurospora crassa, and its activity increases during exponential growth or is induced under different stress conditions. Although extensive progress has been made to identify catalase regulators, the regulation mechanism of CAT-3 at the chromatin level still remains unclear. Here, we aim at investigating the molecular regulation mechanisms of cat-3 at the chromatin level. We found that CAT-3 protein levels increased in mutants defective in proper global heterochromatin formation. Bioinformatics analysis identified a 5-kb AT-rich sequence adjacent to the cat-3 promoter as a heterochromatin region because of its enrichment of H3K9me3 and HP1. Expression of CAT-3 was induced by H₂O₂ treatment in wild-type and such change occurred along with the accumulation of histone H3 acetylation at 5-kb heterochromatin boundaries and cat-3 locus, but without alteration of its H3K9me3 repressive modification. Moreover, disruption of 5-kb heterochromatin region results in elevated cat-3 expression, and higher levels of cat-3 expression were promoted by the combination with global heterochromatin defective mutants. Interestingly, the molecular weight and activity bands of CAT-3 protein are different in heterochromatin defective mutants compared with those in wild-type, suggesting that its N-terminal processing and modification may be altered. Our study indicates that the local chromatin structure creates a heterochromatin repressive environment to repress nearby gene expression.

Mapping 3D fiber orientation in tissue using dual-angle optical polarization tractography

Optical polarization tractography (OPT) has recently been applied to map fiber organization in the heart, skeletal muscle, and arterial vessel wall with high resolution. The fiber orientation measured in OPT represents the 2D projected fiber angle in a plane that is perpendicular to the incident light. We report here a dual-angle extension of the OPT technology to measure the actual 3D fiber orientation in tissue. This method was first verified by imaging the murine extensor digitorum muscle placed at various known orientations in space. The accuracy of the method was further studied by analyzing the 3D fiber orientation of the mouse tibialis anterior muscle. Finally we showed that dual-angle OPT successfully revealed the unique 3D "arcade" fiber structure in the bovine articular cartilage.

Expression of lncRNA HULC in cervical cancer and its correlation with tumor progression and patient survival

OBJECTIVE

To investigate Long non-coding RNA HULC (HULC) expression in cervical cancer and to evaluate its clinical significance.

PATIENTS AND METHODS

HULC expression in 244 pairs of human cervical cancer and adjacent normal tissues was detected by real-time quantitative RT-PCR assay. The correlation between HULC and clinicopathological factors was also evaluated. The clinical and prognostic significance of HULC expression was analyzed statistically by Kaplan-Meier estimate and Cox regression model.

RESULTS

HULC expression was high in cervical cancer (p < 0.01). Also, the high HULC expression was significantly associated with the FIGO stage, lymph node metastasis and depth of cervical invasion (p < 0.05). Kaplan-Meier analysis showed that cervical cancer pa¬tients with high expression of HULC possessed poorer outcome than those with low expression of HULC (p < 0.001). Based on the univariate and multivariate analysis, the elevated expression of the HULC protein was a significant predictor of poor prognosis for cervical cancer patients (p = 0.001).

CONCLUSIONS

Our data firstly showed that the expression of HULC was upregulated in cervical cancer, and associated with overall survival, indicating that HULC may serve as a predictive biomarker for the prognosis of cervical cancer.

Photosynthetic adaptation strategy of Ulva prolifera floating on the sea surface to environmental changes

For 8 consecutive years, a green tide has originated in the southern Yellow Sea and spread to the Qingdao offshore area. The causative species, Ulva prolifera, always forms a very thick thallus mat that is capable of drifting long distances over long periods. During this process, although the thalli face disturbance by complex environmental factors, they maintain high biomass and proliferation. We hypothesized that some form of photosynthetic adaptation strategy must exist to protect the thalli. Therefore, we studied the different photosynthetic response characteristics of the surface and lower layers of the floating thallus mats, and investigated the physiological and molecular-level adaptation mechanisms. The results showed that: (1) U. prolifera has strong photosynthetic capability that ensures it can gain sufficient energy to increase its biomass and adapt to long-distance migration. (2) Surface layer thalli adapt to the complex environment by dissipating excess energy via photosynthetic quantum control (energy quenching and energy redistribution between PSII/PSI) to avoid irreversible damage to the photosynthetic system. (3) Lower layer thalli increase their contents of Chlorophyll a (Chl a) and Chlorophyll b (Chl b) and decrease their Chl a/Chl b ratio to improve their ability to use light energy. (4) U. prolifera has strong photosynthetic plasticity and can adapt to frequent exchange between the surface and lower layer environments because of wave disturbance. Pigment component changes, energy quenching, and energy redistribution between PSII/PSI contribute to this photosynthetic plasticity.