Molecular modeling of interfacial properties of the hydrogen + water + decane mixture in three-phase equilibrium.

The understanding of interfacial phenomena between H2 and geofluids is of great importance for underground H2 storage, but requires further study. We report the first investigation on the three-phase fluid mixture containing H2, H2O, and n-C10H22. Molecular dynamics simulation and PC-SAFT density gradient theory are employed to estimate the interfacial properties under various conditions (temperature ranges from 298 to 373 K and pressure is up to around 100 MPa). Our results demonstrate that interfacial tensions (IFTs) of the H2-H2O interface in the H2 + H2O + C10H22 three-phase mixture are smaller than IFTs in the H2 + H2O two-phase mixture. This decrement of IFT can be attributed to C10H22 adsorption in the interface. Importantly, H2 accumulates in the H2O-C10H22 interface in the three-phase systems, which leads to weaker increments of IFT with increasing pressure compared to IFTs in the water + C10H22 two-phase mixture. In addition, the IFTs of the H2-C10H22 interface are hardly influenced by H2O due to the limited amount of H2O dissolved in nonaqueous phases. Nevertheless, positive surface excesses of H2O are seen in the H2-C10H22 interfacial region. Furthermore, the values of the spreading coefficient are mostly negative revealing the presence of the three-phase contact for the H2 + H2O + C10H22 mixture under studied conditions.

Molecular insights into fluid-solid interfacial tensions in water + gas + solid systems at various temperatures and pressures.

The fluid-solid interfacial tension is of great importance to many applications including the geological storage of greenhouse gases and enhancing the recovery of geo-resources, but it is rarely studied. Extensive molecular dynamics simulations are conducted to calculate fluid-solid interfacial properties in H2O + gas (H2, N2, CH4, and CO2) + rigid solid three-phase systems at various temperatures (298-403 K), pressures (0-100 MPa), and wettabilities (hydrophilic, neutral, and hydrophobic). Our results on the H2O + solid system show that vapor-solid interfacial tension should not be ignored in cases where the fluid-solid interaction energy is strong or the contact angle is close to 90°. As the temperature rises, the magnitude of H2O's liquid-solid interfacial tension declines because the oscillation of the interfacial density/pressure profile weakens at high temperatures. However, the magnitude of H2O vapor-solid interfacial tension is enhanced with temperature due to the stronger adsorption of H2O. Moreover, the H2O-solid interfacial tension in H2O + gas (H2 or N2) + solid systems is weakly dependent on pressure, while the pressure effects on H2O-solid interfacial tensions in systems with CH4 or CO2 are significant. We show that the assumption of pressure independent H2O-solid interfacial tensions should be cautiously applied to Neumann's method for systems containing non-hydrophilic surfaces with strong gas-solid interaction. Meanwhile, the magnitude of gas-solid interfacial tension increases with pressure and gas-solid interaction. High temperatures generally decrease the magnitude of gas-solid interfacial tensions. Further, we found that the increment of contact angle due to the presence of gases follows this order: H2 < N2 < CH4 < CO2.

NR2C2 of macrophages promotes inflammation via NF-κB in LPS-induced orchitis in mice.

In brief: Bacterial infection can induce testicular inflammation and damage male fertility. This paper reveals the role of nuclear receptor subfamily 2 group C member 2 (NR2C2) in macrophage cells in orchitis caused by bacterial endotoxin lipopolysaccharide (LPS) infection. Abstract: Bacterial infection and induced inflammation are important causes of male infertility. Here, we described the characteristics of expression and the regulatory role of NR2C2 in testicular inflammatory injury induced by infection with the bacterial endotoxin LPS. We found that NR2C2 was highly expressed in the testes and the expression of NR2C2 was upregulated in testicular macrophages in the LPS-induced mouse orchitis model in vivo. In primary testicular macrophages and RAW264.7 cells in vitro, RNA interference with the Nr2c2 gene downregulated the expression of inflammatory factors such as IL-1ß and IL-6. In addition, the knockdown of NR2C2 in macrophages alleviated the inhibitory effect of the inflammatory supernatant secreted by the macrophages on the proliferation of spermatogonia GC-1 SPG cells. Mechanistically, NR2C2 activated NF-κB signaling by binding with DR elements in the promotor of the Nfκb gene and promoted the development of inflammation. These data are the first to confirm that during LPS-induced bacterial infection, NR2C2 plays a proinflammatory role by activating IL-1ß and IL-6 via the NF-κB pathway in macrophages, consequently inhibiting the proliferation of spermatogonia and damaging the quality of sperm. Our findings reveal the important role of NR2C2 in testicular inflammatory injury induced via LPS and provide a new potential target and a molecular basis for the treatment of male infertility caused by bacterial infection.

Chromodomain helicase DNA-binding domain 2 maintains spermatogonial self-renewal by promoting chromatin accessibility and mRNA stability.

Chromodomain helicase DNA-binding domain 2 (CHD2) is a chromatin remodeling factor involved in many developmental processes. However, its role in male germ cell development has not been elucidated. Here, we confirm that CHD2 expression is enriched in the male germline. In a heterozygous knockout mouse model of Chd2 (Chd2 +/-), we demonstrated that Chd2 haploinsufficiency resulted in testicular developmental delay, an increased rate of abnormal sperm, and impaired fertility in mice. In vitro experiments in mouse spermatogonia showed that CHD2 knockdown inhibits spermatogonial self-renewal. Mechanistically, CHD2 maintains the enrichment of H3K4me3 in the Ccnb1 and Ccnd2 promotors, consequently promoting the transcription of Ccnb1 and Ccnd2. In addition, CHD2 interacts with the cleavage stimulation factor CSTF3 and upregulates the expression of OCT4 and PLZF by improving mRNA stability. This is the first study to reveal the role and mechanism of CHD2 in maintaining spermatogonial self-renewal.

microRNA-196a-5p inhibits testicular germ cell tumor progression via NR6A1/E-cadherin axis.

Testicular germ cell tumors (TGCTs) are a diverse group of neoplasms that are derived from dysfunctional fetal germ cells and can also present in extragonadal sites. The genetic drivers underlying malignant transformation of TGCTs have not been fully elucidated so far. The aim of the present study is to clarify the functional role and regulatory mechanism of miR-196a-5p in TGCTs. We demonstrated that miR-196a-5p was downregulated in TGCTs. It can inhibit the proliferation, migration, and invasion of testicular tumor cell lines including NT-2 and NCCIT through targeting the NR6A1 gene, which we proved its role in promotion of cell proliferation and repression of cellular junction and aggregation. Mechanistically, NR6A1 inhibited E-cadherin through binding with DR0 sites in the CDH1 gene promoter and recruiting methyltransferases Dnmt1. Further, NR6A1 promoted neuronal marker protein MAP2 expression in RA-induced neurodifferentiation of NT-2 cells and testicular tumor xenografts. Clinical histopathologically, NR6A1 was positively correlated with MAP2, and negatively correlated with E-cadherin in TGCTs. These findings revealed that the miR-196a-5p represses cell proliferation, migration, invasion, and tumor neurogenesis by inhibition of NR6A1/E-cadherin signaling axis, which may be a potential target for diagnosis and therapy of TGCTs.

Significantly enhanced tumor cellular and lysosomal hydroxychloroquine delivery by smart liposomes for optimal autophagy inhibition and improved antitumor efficiency with liposomal doxorubicin.

Hydroxychloroquine (HCQ) inhibits autophagy and therefore can sensitize some cancer cells to chemotherapy, but the high doses required limit its clinical use. Here we show that loading HCQ into liposomes (HCQ/Lip) decorated with a pH-sensitive TH-RGD targeting peptide (HCQ/Lip-TR) can concentrate HCQ in B16F10 tumor cells and lysosomes. HCQ/Lip-TR was efficiently internalized as a result of its ability to bind ITGAV-ITGB3/integrin αvß3 receptors highly expressed on the tumor cell surface and to undergo charge reversal from anionic at pH 7.4 to cationic at pH 6.5. Studies in vitro at pH 6.5 showed that the intracellular HCQ concentration was 35.68-fold higher, and lysosomal HCQ concentration 32.22-fold higher, after treating cultures with HCQ/Lip-TR than after treating them with free HCQ. The corresponding enhancements observed in mice bearing B16F10 tumors were 15.16-fold within tumor cells and 14.10-fold within lysosomes. HCQ/Lip-TR was associated with milder anemia and milder myosuppressive reductions in white blood cell and platelet counts than free HCQ, as well as less accumulation in the small intestine, which may reduce risk of intestinal side effects. In addition, co-delivering HCQ/Lip-TR with either free doxorubicin (DOX) or liposomal DOX improved the ability of DOX to inhibit tumor growth. Biochemical, electron microscopy and immunofluorescence experiments confirmed that HCQ/Lip-TR blocked autophagic flux in tumor cells. Our results suggest that loading HCQ into Lip-TR liposomes may increase the effective concentration of the inhibitor in tumor cells, allowing less toxic doses to be used.

Pharmacological characterization of a novel gastrodin derivative as a potential anti-migraine agent.

Migraine is a highly prevalent neurovascular disorder in the brain. An optimal therapy for migraine has not yet been developed. Gastrodin (Gas), the main effective constitute from Gastrodiae Rhizoma (Tianma in Chinese), has been indicated for migraine treatment and prophylaxis more than 30 years, with demonstrated safety. However, Gas is a phenolic glycoside, with relatively low concentrations and weak efficacy in the central nervous system. To develop more effective anti-migraine agents, we synthesized a novel Gas derivative (Gas-D). In the present study, comparative pharmacodynamic evaluations of Gas and Gas-D were performed in a model of nitroglycerin (NTG)-induced migraine in rats and the hot-plate test in mice. Following behavioral testing in this migraine model, external jugular vein blood and the trigeminal nucleus caudalis (TNC) were collected to analyze plasma nitric oxide (NO) and calcitonin gene-related peptide (CGRP) concentrations and c-Fos expression in the TNC. The acute oral toxicity of Gas and Gas-D was also examined. We found that Gas-D had potent anti-migraine effects, likely attributable to inhibition of both trigeminal nerve activation at central sites and the peripheral release of CGRP following NO scavenging. Additionally, Gas-D exerted significant anti-nociceptive effect in response to thermal pain compared with Gas. Furthermore, a single dose of 2.048 g/kg Gas or Gas-D presented no acute oral toxicity in mice. Altogether, the potent anti-migraine and anti-hyperalgesic effects of Gas-D suggest that it might be a potentially novel drug candidate for migraine treatment or prophylaxis.

A Novel Strategy through Combining iRGD Peptide with Tumor-Microenvironment-Responsive and Multistage Nanoparticles for Deep Tumor Penetration.

Despite the great achievements that nanomedicines have obtained so far, deep penetration of nanomedicines into tumors is still a major challenge in tumor treatment. The enhanced permeability and retention (EPR) effect was the main theoretical foundation for using nanomedicines to treat solid tumor. However, the antitumor efficiency is modest because the tumor is heterogeneous, with dense collagen matrix, abnormal tumor vasculature, and lymphatic system. Nanomedicines could only passively accumulate near leaky site of tumor vessels, and they cannot reach the deep region of tumor. To enhance further the tumor penetration efficiency, we developed a novel strategy of coadministering cell-homing penetration peptide iRGD with size-shrinkable and tumor-microenvironment-responsive multistage system (DOX-AuNPs-GNPs) to overcome these barriers. First, iRGD could specifically increase the permeability of tumor vascular and tumor tissue, leading to more DOX-AuNPs-GNPs leaking out from tumor vasculature. Second, the multistage system passively accumulated in tumor tissue and shrank from 131.1 to 46.6 nm to reach the deep region of tumor. In vitro, coadministering iRGD with DOX-AuNPs-GNPs showed higher cellular uptake and apoptosis ratio. In vivo, coadministering iRGD with DOX-AuNPs-GNPs presented higher penetration and accumulation in tumor than giving DOX-AuNPs-GNPs alone, leading to the best antitumor efficiency in 4T1 tumor-bearing mouse model.

PEGylated fluorescent carbon nanoparticles for noninvasive heart imaging.

Fluorescent carbon nanoparticles (CNP) have gained much attention due to their unique fluorescent properties and safety. In this study, we evaluated the potential application of CNP and PEGylated CNP (PEG-CNP) in noninvasive heart imaging. CNP was prepared by hydrothermal treatment of silk. The particle size and zeta potential of CNP were 121.8 nm and -3.7 mV, respectively, which did not change significantly after PEGylation with a PEG density of 4.43 ± 0.02 µg/mg CNP. FTIR and XPS showed that CNP possessed several functional groups, such as -COOH, -OH, and NH2, which could be utilized for PEGylation and other modifications. CNP displayed strong blue fluorescence after excitation at the wavelength of 375 nm. PEG-CNP displayed better serum stability compared to CNP. The hemolysis rate of PEG-CNP was lower than that of CNP, suggesting PEGylation could enhance the hemocompatibility of CNP. Both CNP and PEG-CNP showed higher uptake capacity by H9c2 cells (a heart cell line) than that by human umbilical vein endothelial cells (HUVEC), suggesting the particles tend to be selectively taken up by heart cells. Both CNP and PEG-CNP were proven to be taken up through endosome-mediated pathway, and the colocalization of nanoparticles with mitochondria was also observed. In vivo results demonstrated that CNP could target heart with much higher fluorescent intensity than liver and spleen. Although PEGylation could decrease the distribution in heart, it remained high for PEG-CNP. In conclusion, CNP could be used for heart imaging, and moreover, PEGylation could improve the stability and biocompatibility of CNP.