Insight into the hydration friction of lipid bilayers.

Hydration layers formed on charged sites play crucial roles in many hydration lubrication systems in aqueous media. However, the underlying molecular mechanism is not well understood. Herein, we explored the hydration friction of lipid bilayers with different charged headgroups at the nanoscale through a combination of frequency-modulation atomic force microscopy and friction force microscopy. The nanoscale friction experiments showed that the hydration friction coefficient and frictional energy dissipation of a cationic lipid (DPTAP) were much lower than those of zwitterionic (DPPE) and anionic (DPPG) lipids. The hydration layer probing at the surfaces of different lipid bilayers clearly revealed the relationship between the charged lipid headgroups and hydration layer structures. Our detailed analysis demonstrated that the cationic lipid had the largest hydration force in comparison with zwitterionic and anionic lipids. These friction and hydration force results indicated that the difference of the lipid headgroup charge resulted in different hydration strengths which led to the difference of hydration friction behaviors. The findings in this study provide molecular insights into the hydration friction of lipid bilayers, which has potential implications for the development of efficient hydration lubrication systems with boundary lipid bilayers in aqueous media.

Transcriptomic landscape based on annotated clinical features reveals PLPP2 involvement in lipid raft-mediated proliferation signature of early-stage lung adenocarcinoma.

BACKGROUND: Image-based screening improves the detection of early-stage lung adenocarcinoma (LUAD)but also highlights the issue of high false-positive diagnoses, which puts patients at a risk of unnecessary over-treatment. Therefore, more precise discrimination criteria are required to ensure that patients with early-stage LUAD receive appropriate treatments. METHODS: We integrated 158 early-stage LUAD cases from 2 independent cohorts, including 30 matched resected specimens with complete radiological and pathological information, and 128 retrospective pathological pair-samples with partial follow-up data. This integration allowed us to conduct a correlation analysis between clinical phenotype and transcriptome landscape. Immunohistochemistry was performed using tissue microarrays to examine the expression of phospholipid phosphatase 2 (PLPP2) and lipid-raft markers. Lipidomics analysis was used to determine the changes of lipid components in PLPP2-overexpressed cells. To assess the effects of PLPP2 on the malignant phenotypes of LUAD cells, we conducted mice tumor-bearing experiments and in vitro cellular experiments by knocking down PLPP2 and inhibiting lipid raft synthesis with MßCD, respectively. RESULTS: Bioinformatics analysis indicated that the co-occurrence of lipid raft formation and rapid cell proliferation might exhibit synergistic effects in driving oncogenesis from lung preneoplasia to adenocarcinoma. The enhanced activation of the cell cycle promoted the transition from non-invasive to invasive status in early-stage LUAD, which was related to an increase in lipid rafts within LUAD cells. PLPP2 participated in lipid raft formation by altering the component contents of lipid rafts, such as esters, sphingomyelin, and sphingosine. Furthermore, elevated PLPP2 levels were identified as an independent prognostic risk factor for LUAD patients. Further results from in vivo and in vitro experiments confirmed that PLPP2 could induce excessive cell proliferation by enhancing lipid raft formation in LUAD cells. CONCLUSIONS: Our study has revealed the characteristics of gene expression profiles in early-stage LUAD patients with the different radiological and pathological subtypes, as well as deciphered transcriptomic evolution trajectory from preneoplasia to invasive LUAD. Furthermore, it suggests that PLPP2-mediated lipid raft synthesis may be a significant biological event in the initiation of early-stage LUAD, offering a potential target for more precise diagnosis and therapy in clinical settings.

Effects of cholesterol and PIP2 on interactions between glycophorin A and Band 3 in lipid bilayers.

In the erythrocyte membrane, the interactions between glycophorin A (GPA) and Band 3 are associated strongly with the biological function of the membrane and several blood disorders. In this work, using coarse-grained molecular-dynamics simulations, we systematically investigate the effects of cholesterol and phosphatidylinositol-4,5-bisphosphate (PIP2) on the interactions of GPA with Band 3 in the model erythrocyte membranes. We examine the dynamics of the interactions of GPA with Band 3 in different lipid bilayers on the microsecond time scale and calculate the binding free energy between GPA and Band 3. The results indicate that cholesterols thermodynamically favor the binding of GPA to Band 3 by increasing the thickness of the lipid bilayer and by producing an effective attraction between the proteins due to the depletion effect. Cholesterols also slow the kinetics of the binding of GPA to Band 3 by reducing the lateral mobility of the lipids and proteins and may influence the binding sites between the proteins. The anionic PIP2 lipids prefer binding to the surface of the proteins through electrostatic attraction between the PIP2 headgroup and the positively charged residues on the protein surface. Ions in the solvent facilitate PIP2 aggregation, which promotes the binding of GPA to Band 3.

VGF: A prospective biomarker and therapeutic target for neuroendocrine and nervous system disorders.

Neuroendocrine regulatory polypeptide VGF (nerve growth factor inducible) was firstly found in the rapid induction of nerve growth factor on PC12 cells. It was selectively distributed in neurons and many neuroendocrine tissues. This paper reviewed the latest literatures on the gene structure, transcriptional regulation, protein processing, distribution and potential receptors of VGF. The neuroendocrine roles of VGF and its derived polypeptides in regulating energy, water electrolyte balance, circadian rhythm and reproductive activities were also summarized. Furthermore, based on the experimental evidence in vivo and in vitro, dysregulation of VGF in different neuroendocrine diseases and the possible mechanism mediated by VGF polypeptides were discussed. We next discussed the potential as the clinical diagnosis and therapy for VGF related diseases in the future.

An oxygen-adaptive interaction between SNHG12 and occludin maintains blood-brain barrier integrity.

Tight junctions (TJs) of brain microvascular endothelial cells (BMECs) play a pivotal role in maintaining the blood-brain barrier (BBB) integrity; however, precise regulation of TJs stability in response to physiological and pathological stimuli remains elusive. Here, using RNA immunoprecipitation with next-generation sequencing (RIP-seq) and functional characterization, we identify SNHG12, a long non-coding RNA (lncRNA), as being critical for maintaining the BBB integrity by directly interacting with TJ protein occludin. The interaction between SNHG12 and occludin is oxygen adaptive and could block Itch (an E3 ubiquitin ligase)-mediated ubiquitination and degradation of occludin in human BMECs. Genetic ablation of endothelial Snhg12 in mice results in occludin reduction and BBB leakage and significantly aggravates hypoxia-induced BBB disruption. The detrimental effects of hypoxia on BBB could be alleviated by exogenous SNHG12 overexpression in brain endothelium. Together, we identify a direct TJ modulator lncRNA SNHG12 that is critical for the BBB integrity maintenance and oxygen adaption.

NOD2 deficiency confers a pro-tumorigenic macrophage phenotype to promote lung adenocarcinoma progression.

Nucleotide-binding and oligomerization domain-containing protein 2 (NOD2) was a member of the NOD-like receptor family and played an important role in the innate immune response. Dysregulated NOD2 had been reported to contribute to tumorigenesis and progression. Here, we investigated that decreased NOD2 expressions could affect the phenotypic polarization of tumour-associated macrophages and thus lead to the poor prognosis of lung adenocarcinoma patients. We clustered the patients by the single-sample gene set enrichment analysis of tumour microenvironment and 13 prognostic differentially expressed immune-related genes (PDEIRGs) were obtained based on prognostic analyses. After multiple assessments on the 13 PDEIRGs, NOD2 was considered to be the central immune gene and had a strong effect on suppressing tumour progression. Decreased NOD2 expression could be induced by cancer cells and lead to the phenotypic polarization of macrophages from protective M1 phenotype to pro-tumorigenic M2 subtype which might be attributed to the down-regulating of NF-κB signalling pathway. This study draw attention to the role of inhibited innate immune function mediated by depletion of NOD2 in the TME. Our work also points to a potential strategy of NOD2-mediated TAM-targeted immunotherapy.

BTK Has Potential to Be a Prognostic Factor for Lung Adenocarcinoma and an Indicator for Tumor Microenvironment Remodeling: A Study Based on TCGA Data Mining.

Tumor microenvironment (TME) plays a crucial role in the initiation and progression of lung adenocarcinoma (LUAD); however, there is still a challenge in understanding the dynamic modulation of the immune and stromal components in TME. In the presented study, we applied CIBERSORT and ESTIMATE computational methods to calculate the proportion of tumor-infiltrating immune cell (TIC) and the amount of immune and stromal components in 551 LUAD cases from The Cancer Genome Atlas (TCGA) database. The differentially expressed genes (DEGs) were analyzed by COX regression analysis and protein-protein interaction (PPI) network construction. Then, Bruton tyrosine kinase (BTK) was determined as a predictive factor by the intersection analysis of univariate COX and PPI. Further analysis revealed that BTK expression was negatively correlated with the clinical pathologic characteristics (clinical stage, distant metastasis) and positively correlated with the survival of LUAD patients. Gene Set Enrichment Analysis (GSEA) showed that the genes in the high-expression BTK group were mainly enriched in immune-related activities. In the low-expression BTK group, the genes were enriched in metabolic pathways. CIBERSORT analysis for the proportion of TICs revealed that B-cell memory and CD8+ T cells were positively correlated with BTK expression, suggesting that BTK might be responsible for the preservation of immune-dominant status for TME. Thus, the levels of BTK might be useful for outlining the prognosis of LUAD patients and especially be a clue that the status of TME transition from immune-dominant to metabolic activity, which offered an extra insight for therapeutics of LUAD.

Caspr1 Facilitates sAPPα Production by Regulating α-Secretase ADAM9 in Brain Endothelial Cells.

The expression of contactin-associated protein 1 (Caspr1) in brain microvascular endothelial cells (BMECs), one of the major cellular components of the neurovascular unit (NVU), has been revealed recently. However, the physiological role of Caspr1 in BMECs remains unclear. We previously reported the nonamyloidogenic processing of amyloid protein precursor (APP) pathway in the human BMECs (HBMECs). In this study, we found Caspr1 depletion reduced the levels of soluble amyloid protein precursor α (sAPPα) in the supernatant of HBMECs, which could be rescued by expression of full-length Caspr1. Our further results showed that ADAM9, the α-secretase essential for processing of APP to generate sAPPα, was decreased in Caspr1-depleted HBMECs. The reduced sAPPα secretion in Caspr1-depleted HBMECs was recovered by expression of exogenous ADAM9. Then, we identified that Caspr1 specifically regulates the expression of ADAM9, but not ADAM10 and ADAM17, at transcriptional level by nuclear factor-κB (NF-κB) signaling pathway. Caspr1 knockout attenuated the activation of NF-κB and prevented the nuclear translocation of p65 in brain endothelial cells, which was reversed by expression of full-length Caspr1. The reduced sAPPα production and ADAM9 expression upon Caspr1 depletion were effectively recovered by NF-κB agonist. The results of luciferase assays indicated that the NF-κB binding sites are located at -859 bp to -571 bp of ADAM9 promoter. Taken together, our results demonstrated that Caspr1 facilitates sAPPα production by transcriptional regulation of α-secretase ADAM9 in brain endothelial cells.

Lung Cancer Cells-Controlled Dkk-1 Production in Brain Metastatic Cascade Drive Microglia to Acquire a Pro-tumorigenic Phenotype.

OBJECTIVES: Organotropism is primarily determined by tumor-derived exosomes. To date, the role of lung cancer cells-derived exosomes underlying the pre-metastatic niche formation is unclear. MATERIALS AND METHODS: The animal models of retro-orbital and intra-ventricular injection were constructed to administrate lung cancer cells-derived exosomes. Cytokine array was used to screen the cytokines released from brain endothelium after internalization of lung cancer cells-derived exosomes. The cellular co-culture system was established to mimic microglia-vascular niche contained lung cancer cells-derived exosomes. The levels of Dkk-1 and the activities of microglia were analyzed by qRT-PCR, western blot and immunofluorescence. In vivo selections of highly brain metastatic cells were performed to analyze the direct interaction of lung cancer cells with microglia. RESULTS: Animal studies demonstrated that there was a suppressive signal transferred from brain endothelium to microglia after internalization of lung cancer cells-derived exosomes into brain endothelium, which caused an absolutely less M1 phenotypic microglia and a relatively more M2 phenotypic microglia. Further results indicated that lung cancer cells-derived exosomes induced a release of endogenous Dkk-1 from brain endothelium, which rendered microglia to acquire a pro-tumorigenic feature in pre-metastatic niche. Subsequently, the declines of Dkk-1 in metastatic lung cancer cells removed the suppression on microglia and enhanced microglial activation in metastatic niche. CONCLUSION: Our findings shed a new light on the synergistic reaction of the different cells in "neurovascular units" toward the metastatic messages from lung cancer cells and provided a potential therapeutic pathway for lung cancer metastasis to brain.

Isobavachalcone isolated from Psoralea corylifolia inhibits cell proliferation and induces apoptosis via inhibiting the AKT/GSK-3ß/ß-catenin pathway in colorectal cancer cells.

Background: Colorectal cancer (CRC) is a common form of cancer associated with a high mortality rate and poor prognosis. Given the limited efficacy of current therapies for CRC, interest in novel therapeutic agents isolated from natural sources has increased. We studied the anticancer properties of isobavachalcone (IBC), a flavonoid isolated from the herb Psoralea corylifolia, which is used in traditional Chinese medicine, in an in vitro model of CRC. Materials and methods: Cell viability and growth of CRC cells were determined by Cell Counting Kit-8 and colony formation assays following treatment with varying concentrations of IBC, respectively. Apoptosis was examined by 4',6-diamidino-2-phenylindole staining and flow cytometry with Annexin V/propidium iodide double staining. Western blot analysis was used to analyze expression of apoptosis-associated protein pathway and the AKT/GSK-3ß/ß-catenin signaling pathway. Results: Initial experiments showed that IBC inhibited proliferation and colony formation of human CRC cell lines in dose- and time-dependent manners. The antiproliferative effect of IBC resulted from induction of apoptosis, as evidenced by morphological changes in the nucleus, flow cytometry analysis, upregulation of cleaved caspase-3 and cleaved PARP, changes in the ratio of the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax, translocation of Bax from the cytosol to the mitochondria, and decreased expression of two inhibitors of apoptosis family proteins, XIAP, and survivin. Western blot analysis of signaling pathway proteins demonstrated that IBC downregulated Wnt/ß-catenin signaling, which has previously been associated with CRC, by inhibiting the AKT/GSK-3ß signaling pathway. Conclusion: This study demonstrated that IBC inhibited cell proliferation and induced apoptosis through inhibition of the AKT/GSK-3ß/ß-catenin pathway in CRC. These results suggest the potential of IBC as a novel therapeutic agent for the treatment of CRC.

A CASPR1-ATP1B3 protein interaction modulates plasma membrane localization of Na+/K+-ATPase in brain microvascular endothelial cells.

Contactin-associated protein 1 (CASPR1 or CNTNAP1) was recently reported to be expressed in brain microvascular endothelial cells (BMECs), the major component of the blood-brain barrier. To investigate CASPR1's physiological role in BMECs, here we used CASPR1 as a bait in a yeast two-hybrid screen to identify CASPR1-interacting proteins and identified the ß3 subunit of Na+/K+-ATPase (ATP1B3) as a CASPR1-binding protein. Using recombinant and purified CASPR1, RNAi, GST-pulldown, immunofluorescence, immunoprecipitation, and Na+/K+-ATPase activity assays, we found that ATP1B3's core proteins, but not its glycosylated forms, interact with CASPR1, which was primarily located in the endoplasmic reticulum of BMECs. CASPR1 knockdown reduced ATP1B3 glycosylation and prevented its plasma membrane localization, phenotypes that were reversed by expression of full-length CASPR1. We also found that the CASPR1 knockdown reduces the plasma membrane distribution of the α1 subunit of Na+/K+-ATPase, which is the major component assembled with ATP1B3 in the complete Na+/K+-ATPase complex. The binding of CASPR1 with ATP1B3, but not the α1 subunit, indicated that CASPR1 binds with ATP1B3 to facilitate the assembly of Na+/K+-ATPase. Furthermore, the activity of Na+/K+-ATPase was reduced in CASPR1-silenced BMECs. Interestingly, shRNA-mediated CASPR1 silencing reduced glutamate efflux through the BMECs. These results demonstrate that CASPR1 binds with ATP1B3 and thereby contributes to the regulation of Na+/K+-ATPase maturation and trafficking to the plasma membrane in BMECs. We conclude that CASPR1-mediated regulation of Na+/K+-ATPase activity is important for glutamate transport across the blood-brain barrier.

Brain microvascular endothelial cell exosome-mediated S100A16 up-regulation confers small-cell lung cancer cell survival in brain.

Small cell lung cancer (SCLC) is the most aggressive histologic subtype of lung cancer, with a strong predilection for early brain metastases. Despite efforts and advances in new therapeutics for SCLC, the prognosis of patients with SCLC with brain metastases is consistently poor. Therefore, a better understanding of the mechanisms of SCLC brain metastasis is important in improving current treatments. In this study, elevated S100A16 levels were associated with SCLC brain metastases, which was a possible secondary event arising from the brain metastatic microenvironment. Using an in vitro cell coculture system, we found that the coculturing of SCLC cells with human brain microvascular endothelial cells (HBMECs) led to an increased expression of S100A16 in SCLC cells. Conversely, treatment of HBMECs with GW4869, an inhibitor of exosome release, significantly blocked this effect in the cocultured SCLC cells. Alternatively, the results from Western blot analyses and immunofluorescence indicated that the HBMEC exosomes purified by ultracentrifugation also induced the elevation and translocation from the cytoplasm to the nucleus of S100A16 in the recipient SCLC cells. The inhibition experiments demonstrated that elevated S100A16 contributed a benefit of HBMEC exosomes for the survival of the recipient SCLC cells under stress. Moreover, the elevation of S100A16 in SCLC cells prevented the loss of mitochondrial membrane potential (Δψm) and enhanced resistance to apoptosis under stressful conditions, which were determined by Annexin V/propidium iodide and JC-1 assay. Further results showed that the S100A16-mediated protective effect was caused by the presence of an important element in Δψm, prohibitin (PHB)-1, a protein in the mitochondrial inner membrane. Conversely, the delivery of PHB-1 siRNAs into S100A16 overexpressing SCLC cells weakened these protective effects. Our findings suggest that elevated S100A16 plays an active role in facilitating the survival of SCLC cells through modulating the mitochondrial function, identifying S100A16 as an important potential target in SCLC brain metastasis.-Xu, Z.-H., Miao, Z.-W., Jiang, Q.-Z., Gan, D.-X., Wei, X.-G., Xue, X.-Z., Li, J.-Q., Zheng, F., Qin, X.-X., Fang, W.-G., Chen, Y.-H., Li. B. Brain microvascular endothelial cell exosome-mediated S100A16 up-regulation confers small cell lung cancer cell survival in brain.

Caspr1 is a host receptor for meningitis-causing Escherichia coli.

Escherichia coli is the leading cause of neonatal Gram-negative bacterial meningitis, but the pathogenesis of E. coli meningitis remains elusive. E. coli penetration of the blood-brain barrier (BBB) is the critical step for development of meningitis. Here, we identify Caspr1, a single-pass transmembrane protein, as a host receptor for E. coli virulence factor IbeA to facilitate BBB penetration. Genetic ablation of endothelial Caspr1 and blocking IbeA-Caspr1 interaction effectively prevent E. coli penetration into the brain during meningitis in rodents. IbeA interacts with extracellular domain of Caspr1 to activate focal adhesion kinase signaling causing E. coli internalization into the brain endothelial cells of BBB. E. coli can invade hippocampal neurons causing apoptosis dependent on IbeA-Caspr1 interaction. Our results indicate that E. coli exploits Caspr1 as a host receptor for penetration of BBB resulting in meningitis, and that Caspr1 might be a useful target for prevention or therapy of E. coli meningitis.

Cystatin C Shifts APP Processing from Amyloid-ß Production towards Non-Amyloidgenic Pathway in Brain Endothelial Cells.

Amyloid-ß (Aß), the major component of neuritic plaques in Alzheimer's disease (AD), is derived from sequential proteolytic cleavage of amyloid protein precursor (APP) by secretases. In this study, we found that cystatin C (CysC), a natural cysteine protease inhibitor, is able to reduce Aß40 secretion in human brain microvascular endothelial cells (HBMEC). The CysC-induced Aß40 reduction was caused by degradation of ß-secretase BACE1 through the ubiquitin/proteasome pathway. In contrast, we found that CysC promoted secretion of soluble APPα indicating the activated non-amyloidogenic processing of APP in HBMEC. Further results revealed that α-secretase ADAM10, which was transcriptionally upregulated in response to CysC, was required for the CysC-induced sAPPα secretion. Knockdown of SIRT1 abolished CysC-triggered ADAM10 upregulation and sAPPα production. Taken together, our results demonstrated that exogenously applied CysC can direct amyloidogenic APP processing to non-amyloidgenic pathway in brain endothelial cells, mediated by proteasomal degradation of BACE1 and SIRT1-mediated ADAM10 upregulation. Our study unveils previously unrecognized protective role of CysC in APP processing.

Carboxymethyl Chitosan-Modified Polyamidoamine Dendrimer Enables Progressive Drug Targeting of Tumors via pH-Sensitive Charge Inversion.

Polyamidoamine dendrimers are potential candidates for drug delivery systems due to their remarkable cell-penetrating power that results from their strong positive surface charge. However, the positively charged surfaces always lead to serious cytotoxicity and the rapid clearance of polyamidoamine in vivo, which limit the application of these dendrimers. To overcome these drawbacks, we developed a carboxymethyl chitosan-modified polyamidoamine dendrimer to achieve progressive drug targeting of tumors via pH-sensitive charge inversion. With the shielding of carboxymethyl chitosan, the complex was negatively charged at physiological conditions (pH 7.4) and prone to enrich at tumor sites due to the enhanced permeation and retention effect; however, it regained a positive charge via the removal of the carboxymethyl chitosan coating under tumor-acidic conditions (pH 6.5) and achieved high intracellular uptake in tumor cells through electrostatic adsorptive endocytosis. In this study, these dendrimers exhibited 1.99- and 1.76-times higher cellular uptake efficiencies at pH 7.4 in MCF-7 or A549 cells, respectively, compared with efficiencies at pH 6.5, indicating an effective pH-dependent accumulation; the fluorescence intensities of these cells exposed to the dendrimers at pH 6.5 were also 16.45- and 9.27-fold greater, respectively, than those of free doxorubicin. After intravenous administration in mice bearing H22 tumors, doxorubicin-loaded dendrimers exhibited a 1.50-fold greater antitumor activity and presented no obvious systematic toxicity based on histological analysis compared with free drugs. Overall, a simple decoration of carboxymethyl chitosan demonstrated to be a promising way for cationic nanocarriers to achieve pH-sensitive drug release and charge conversion response to tumor microenvironment pH and enhance the antitumor therapy efficiency of anticancer drugs.

Intra-articular Administration of Chitosan Thermosensitive In Situ Hydrogels Combined With Diclofenac Sodium-Loaded Alginate Microspheres.

The aims of this study were to prepare fine intra-articular-administrated chitosan thermosensitive hydrogels combined with alginate microspheres and to investigate the possibility of those hydrogels as a drug delivery system for promoting the anti-inflammation effect. Diclofenac sodium containing alginate microspheres was prepared by a modified emulsification and/or gelation method and then dispersed into injectable thermosensitive hydrogels, consisting of chitosan and ß-glycerophosphate. The final combined hydrogels were evaluated in terms of their morphology properties, rheological properties, in vitro drug release, and in vivo biocompatibility and pharmacodynamics behaviors. The optimized formulation exhibited sol-gel transition at 31.72 ± 0.42°C and quickly turned into gel within 5 min, with sustained drug release characteristics followed Ritger-Peppas equation, which could prolong the in vitro drug release to 5 days. In addition, the anti-inflammation efficacy of the combined hydrogels in rabbits with experimental rheumatoid arthritis was higher than that of drug solution and pure chitosan hydrogels. Those results demonstrated that these combined hydrogels could become a potential drug delivery system for improving the therapeutic effect of diclofenac sodium and suggested an important technology platform for intra-articular administration.

Topotecan hydrochloride liposomes incorporated into thermosensitive hydrogel for sustained and efficient in situ therapy of H22 tumor in Kunming mice.

Topotecan hydrochloride (TPT) has potential for the treatment of ovarian cancer, but the activity of TPT tends to decrease due to the ring-opening at physiological pH. In this study, we proposed to incorporate TPT liposomes into injectable thermosensitive in situ hydrogel, consisting of chitosan (CS) and ß-glycerophosphate (ß-GP), for sustained release and preservation of active lactone form of TPT. The rheology studies were carried out to investigate the sol-gel temperature, flow behavior and viscosity of these CS/ß-GP systems. The optimized formulation exhibited sol-gel transition at 40.2 ± 0.4 °C, with pseudoplastic flow behavior. The drug release rate of TPT liposomes loaded CS/ß-GP hydrogel in phosphate buffer saline (pH = 7.4) was found to be slowed down, and the lactone fraction of TPT in the hydrogel matrix was maintaining 40% after 50 h. In addition, the antitumor efficacy in Kunming mice bearing Hepatoma-22 tumor, after intratumoral injection of TPT liposomes loaded CS/ß-GP hydrogel, was higher than that of TPT in saline and TPT in CS/ß-GP hydrogel. Those results demonstrated that TPT liposomes loaded CS/ß-GP hydrogel could become a potential formulation for improving the antitumor efficacy of TPT and suggested an important technology platform for intratumoral administration of derivative of camptothecin-family drugs.

Association between tumor necrosis factor-α gene polymorphisms and diffuse large B-cell lymphoma in Chinese Han population: evidence from two center case-control study and a meta-analysis.

OBJECTIVES: The tumor necrosis factor-α (TNF-α) gene, which plays crucial roles in tumorigenesis, is reported to be an independent marker for cancer. This study aims to examine the association between the TNF-α G308A polymorphism and DLBCL risk based on the two center case-control studies and meta-analysis. METHODS: In the current study, we performed a two centers case-control study to investigate the effect of the TNF-α G308A polymorphism on DLBCL risk in Chinese Han population. A meta-analysis including 10 published datasets along with current dataset, including 111 comparisons containing 34,041 cases and 42,730 controls were enrolled, was next performed to further confirm the association after literature search was conducted and relevant studies were identified from PubMed, Embase, and Web of Science. RESULTS: The TNF-α -308A allele was associated with a significantly increased DLBCL risk in the two independent patient case-control studies and additionally for pooled analysis from the two sets (P<0.05 for both). The result of meta-analysis further demonstrated that the A allele of -308A was significantly correlated with DLBCL risk under the allelic model (OR=1.35, 95% CI=1.27-1.44) without heterogeneity by fixed-effects model analysis (Q=17.30, P=0.139). Moreover, sensitivity analysis supported the robustness of this meta-analysis. CONCLUSION: This study suggested that -308A polymorphism may be associated with the susceptibility of DLBCL in a Chinese population. The further meta-analysis provides additional evidence supporting the above result that the risk allele of the -308A polymorphism may increase DLBCL risk.

Ephrin-A3 and ephrin-A4 contribute to microglia-induced angiogenesis in brain endothelial cells.

The association of microglia with brain vasculature during development and the reduced brain vascular complexity in microglia-deficient mice suggest the role of microglia in cerebrovascular angiogenesis. However, the underlying molecular mechanism remains unclear. Here, using an in vitro angiogenesis model, we found the culture supernatant of BV2 microglial cells significantly enhanced capillary-like tube formation and migration of brain microvascular endothelial cells (BMECs). The expression of angiogenic factors, ephrin-A3 and ephrin-A4, were specifically upregulated in BMECs exposed to BV2-derived culture supernatant. Knockdown of ephrin-A3 and ephrin-A4 in BMECs by siRNA significantly attenuated the enhanced angiogenesis and migration of BMECs induced by BV2 supernatant. Our further results indicated that the ability of BV2 supernatant to promote endothelial angiogenesis was caused by the soluble tumor necrosis factor α (TNF-α) released from BV2 microglial cells. Moreover, the upregulations of ephrin-A3 and ephrin-A4 in BMECs in response to BV2 supernatant were effectively abolished by neutralization antibody against TNF-α and TNF receptor 1, respectively. The present study provides evidence that microglia upregulates endothelial ephrin-A3 and ephrin-A4 to facilitate in vitro angiogenesis of brain endothelial cells, which is mediated by microglia-released TNF-α.