Inhibition of NKCC1 Ameliorates Anxiety and Autistic Behaviors Induced by Maternal Immune Activation in Mice.

Autism spectrum disorder (ASD) is thought to result from susceptibility genotypes and environmental risk factors. The offspring of women who experience pregnancy infection have an increased risk for autism. Maternal immune activation (MIA) in pregnant animals produces offspring with autistic behaviors, making MIA a useful model for autism. However, how MIA causes autistic behaviors in offspring is not fully understood. Here, we show that NKCC1 is critical for mediating autistic behaviors in MIA offspring. We confirmed that MIA induced by poly(I:C) infection during pregnancy leads to autistic behaviors in offspring. We further demonstrated that MIA offspring showed significant microglia activation, excessive dendritic spines, and narrow postsynaptic density (PSD) in their prefrontal cortex (PFC). Then, we discovered that these abnormalities may be caused by overexpression of NKCC1 in MIA offspring's PFCs. Finally, we ameliorated the autistic behaviors using PFC microinjection of NKCC1 inhibitor bumetanide (BTN) in MIA offspring. Our findings may shed new light on the pathological mechanisms for autism caused by pregnancy infection.

First principles studies on the adsorption of rare base-pairs on the surface of B/N atom doped γ-graphyne.

Rare base-pairs consists of guanine (G) paired with rare bases, such as 5-methylcytosine (5-meCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-carboxylcytosine (5-caCyt), and 5-formylcytosine (5-fCyt), have become the focus of epigenetic research because they can be used as markers to detect some chronic diseases and cancers. However, the correlation detection of these rare base-pairs is limited, which in turn limits the development of diagnostic tests and devices. Herein, the interaction of rare base-pairs adsorbed on pure and B/N-doped γ-graphyne (γ-GY) nanosheets was explored using the density functional theory. The calculated adsorption energy showed that the system of rare base-pairs on B-doped γ-GY is more stable than that on pure γ-GY or N-doped γ-GY. Translocation time values indicate that rare base-pairs can be successfully distinguished as the difference in their translocation times is very large for pure and B/N-doped γ-GY nanosheets. Meanwhile, sensing response values illustrated that pure and B-doped γ-GY are the best for G-5-hmCyt adsorption, while the N-doped γ-GY is the best for G-Cyt adsorption. The findings indicate that translocation times and sensing response can be used as detection indexes for pure and B/N doped γ-GY, which will provide a new way for experimental scientists to develop the biosensor components.

Melatonin attenuated chronic visceral pain by reducing Nav1.8 expression and nociceptive neuronal sensitization.

BACKGROUND: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, and its specific pathogenesis is still unclear. We have previously reported that TTX-resistant (TTX-R) sodium channels in colon-specific dorsal root ganglion (DRG) neurons were sensitized in a rat model of visceral hypersensitivity induced by neonatal colonic inflammation (NCI). However, the detailed molecular mechanism for activation of sodium channels remains unknown. This study was designed to examine roles for melatonin (MT) in sensitization of sodium channels in NCI rats. METHODS: Colorectal distention (CRD) in adult male rats as a measure of visceral hypersensitivity. Colon-specific dorsal root ganglion (DRG) neurons were labeled with DiI and acutely dissociated for measuring excitability and sodium channel current under whole-cell patch clamp configurations. Western blot and Immunofluorescence were employed to detect changes in expression of Nav1.8 and MT2. RESULTS: The results showed that rats exhibited visceral hypersensitivity after NCI treatment. Intrathecal application of melatonin significantly increased the threshold of CRD in NCI rats with a dose-dependent manner, but has no role in the control group. Whole-cell patch clamp recording showed that melatonin remarkably decreased the excitability and the density of TTX-R sodium channel in DRG neurons from NCI rats. The expression of MT2 receptor at the protein level was markedly lower in NCI rats. 8MP, an agonist of MT2 receptor, enhanced the distention threshold in NCI rats. Application of 8MP reversed the enhanced hypersensitivity of DRG neurons from NCI rats. 8MP also reduced TTX-R sodium current density and modulated dynamics of TTX-R sodium current activation. CONCLUSIONS: These data suggest that sensitization of sodium channels of colon DRG neurons in NCI rats is most likely mediated by MT2 receptor, thus identifying a potential target for treatment for chronic visceral pain in patients with IBS.

Ab initio studies on graphyne (GY) for the detection of rare bases in DNA.

Graphyne (GY) and functionalized GY have become cutting-edge research materials for the scientific community. In the present work, the adsorption of rare bases -cytosine (Cyt), 5-methylcytosine (5-meCyt), 5-hydroxymethylcytosine (5-hmCyt), 5-formoxylcytosine (5-fCyt), and 5-carboxylcytosine (5-caCyt) on pristine, B- and N-doped γ-GY was investigated by the first-principles density functional method; methods were designed to distinguish these rare bases by the translocation time and sensitivity. Initially, the stability of pristine, B- and N-doped γ-GY was ascertained by the cohesion energy, and the electronic properties were also analyzed by the energy gap and density of state (DOS). When adsorbing over pristine γ-GY, the translocation times of rare bases were 1.34 × 101, 4.71 × 101, 1.19 × 104, 3.77 × 10-1 and 1.93 × 101 s, respectively. The sensitivities were 2.19%, 0.88%, 0.22%, 2.41%, and 0.88%, respectively, which indicates that they were not clearly separated. By doping the impurity atom, the electronic properties can be fine-tuned to change their selectivity. When adsorbing on the B-doped γ-GY, these rare bases showed sensitivities of 24.69%, 27.20%, 43.32%, 29.97%, and 32.24%, respectively. The rare bases showed sensitivities of 10.15%, 9.02%, 17.29%, 0.38%, and 3.76%, respectively, when adsorbing over the N-doped γ-GY, which greatly increases selectivities for recognization. Thus, these results indicate that pristine and doped γ-GY, as the electrical sensing material, can be used to detect rare bases.

DCAF13 promotes breast cancer cell proliferation by ubiquitin inhibiting PERP expression.

Evolutionarily conserved DDB1-and CUL4-associated factor 13 (DCAF13) is a recently discovered substrate receptor for the cullin RING-finger ubiquitin ligase 4 (CRL4) E3 ubiquitin ligase that regulates cell cycle progression. DCAF13 is overexpressed in many cancers, although its role in breast cancer is currently elusive. In this study we demonstrate that DCAF13 is overexpressed in human breast cancer and that its overexpression closely correlates with poor prognosis, suggesting that DCAF13 may serve as a diagnostic marker and therapeutic target. We knocked down DCAF13 in breast cancer cell lines using CRISPR/Cas9 and found that DCAF13 deletion markedly reduced breast cancer cell proliferation, clone formation, and migration both in vitro and in vivo. In addition, DCAF13 deletion promoted breast cancer cell apoptosis and senescence, and induced cell cycle arrest in the G1/S phase. Genome-wide RNAseq analysis and western blotting revealed that loss of DCAF13 resulted in both mRNA and protein accumulation of p53 apoptosis effector related to PMP22 (PERP). Knockdown of PERP partially reversed the hampered cell proliferation induced by DCAF13 knockdown. Co-immunoprecipitation assays revealed that DCAF13 and DNA damage-binding protein 1 (DDB1) directly interact with PERP. Overexpression of DDB1 significantly increased PERP polyubiquitination, suggesting that CRL4DCAF13 E3 ligase targets PERP for ubiquitination and proteasomal degradation. In conclusion, DCAF13 and the downstream effector PERP occupy key roles in breast cancer proliferation and potentially serve as prognostics and therapeutic targets.

The use of vertical flow constructed wetlands for the treatment of hyper-eutrophic water bodies with dense cyanobacterial blooms.

Eutrophication often leads to the periodic proliferation of harmful cyanobacterial blooms (HCBs), which threaten the sustainability of freshwater ecosystems and lead to serious environmental, health and economic damage. Hence, it is vitally important to take effective measures to manage HCBs and associated problems. In this study, vertical flow constructed wetlands (CWs) were operated under different hydraulic loading rates (HLRs) to treat a hyper-eutrophic water body with HCBs. Six sampling ports (representing different layers) were evenly distributed along the water flow direction to study the purification processes of CWs. With HLRs ranging from 0.2 m/d to 0.8 m/d, total nitrogen (TN), total phosphorus (TP), COD, total suspended solid (TSS) and Chlorophyll a (Chl.a) were efficiently treated by CWs, and they were mainly removed at the second layer of CWs. The concentrations of two cyanobacterial metabolites (geosmin and ß-cyclocitral) in the effluent were mostly below their odorous threshold concentrations. As the HLRs increased, the treatment efficiencies of the CWs decreased gradually. There was no removal of TP, Chl.a, geosmin, or ß-cyclocitral at an HLR of 1.0 m/d. Under suitable HLRs, this type of CW could provide a promising way to control HCBs and associated odorous problems in hyper-eutrophic water bodies.

Formic acid catalyzed isomerization of protonated cytosine: a lower barrier reaction for tautomer production of potential biological importance.

Tautomerism in nucleotide bases is one of the possible mechanisms of DNA mutation. In spite of numerous studies on the structure and energy of protonated cytosine tautomers, little information is available on the process of their intra- and intermolecular tautomerizations. The catalytic ability of H2O, HCOOH, and the HCOOHH2O group to facilitate the tautomerism of the Cyt2t+ to CytN3+ isomer has been studied. It is shown that the activation free energies of tautomerism in the gas phase are 161.17, 58.96, 26.06, and 15.69 kJ mol-1, respectively, when the reaction is carried out in the absence and presence of H2O, HCOOH, or the HCOOHH2O group. The formation of a doubly hydrogen bonded transition state is central to lowering the activation free energy and facilitating the intramolecular hydrogen atom transfer that is required for isomerization. In the aqueous phase, although the solvent effects of water significantly decrease the activation free energy of intramolecular tautomerization, the isomerization of the Cyt2t+ to CytN3+ isomer remains unfavorable, and the HCOOH and HCOOHH2O group mediated mechanisms are still more favorable. Meanwhile, conventional transition state theory (CTST) followed by Wigner tunneling correction is then applied to estimate the rate constants. The rate constant with Wigner tunneling correction for direct tautomerization is obviously smaller than that of HCOOH-mediated tautomerization, which is the most plausible mechanism. Finally, another important finding is that the product complex (CytN3+HCOOH) is in the rapid tautomeric equilibrium with the reaction complex (Cyt2t+HCOOH) (τ99.9% = 3.84 × 10-12 s), which is implemented by the mechanism of the concerted synchronous double proton transfer. Its lifetime of the formed CytN3+HCOOH complex (τ = 8.33 × 10-9 s) is almost one order of magnitude larger than the time required for the replication machinery to forcibly dissociate a base pair into the monomers during DNA replication (several ns), which is further dissociated into the CytN3+ and HCOOH monomers. The results of the present study demonstrate the feasibility of acid catalysis for DNA base isomerization reactions that would otherwise be forbidden.

Correction: Formic acid catalyzed isomerization of protonated cytosine: a lower barrier reaction for tautomer production of potential biological importance.

Correction for 'Formic acid catalyzed isomerization of protonated cytosine: a lower barrier reaction for tautomer production of potential biological importance' by Lingxia Jin et al., Phys. Chem. Chem. Phys., 2017, 19, 13515-13523.