Endothelial cell SHP-2 negatively regulates neutrophil adhesion and promotes transmigration by enhancing ICAM-1-VE-cadherin interaction.

Intercellular adhesion molecule-1 (ICAM-1) mediates the firm adhesion of leukocytes to endothelial cells and initiates subsequent signaling that promotes their transendothelial migration (TEM). Vascular endothelial (VE)-cadherin plays a critical role in endothelial cell-cell adhesion, thereby controlling endothelial permeability and leukocyte transmigration. This study aimed to determine the molecular signaling events that originate from the ICAM-1-mediated firm adhesion of neutrophils that regulate VE-cadherin's role as a negative regulator of leukocyte transmigration. We observed that ICAM-1 interacts with Src homology domain 2-containing phosphatase-2 (SHP-2), and SHP-2 down-regulation via silencing of small interfering RNA in endothelial cells enhanced neutrophil adhesion to endothelial cells but inhibited neutrophil transmigration. We also found that VE-cadherin associated with the ICAM-1-SHP-2 complex. Moreover, whereas the activation of ICAM-1 leads to VE-cadherin dissociation from ICAM-1 and VE-cadherin association with actin, SHP-2 down-regulation prevented ICAM-1-VE-cadherin association and promoted VE-cadherin-actin association. Furthermore, SHP-2 down-regulation in vivo promoted LPS-induced neutrophil recruitment in mouse lung but delayed neutrophil extravasation. These results suggest that SHP-2-via association with ICAM-1-mediates ICAM-1-induced Src activation and modulates VE-cadherin switching association with ICAM-1 or actin, thereby negatively regulating neutrophil adhesion to endothelial cells and enhancing their TEM.-Yan, M., Zhang, X., Chen, A., Gu, W., Liu, J., Ren, X., Zhang, J., Wu, X., Place, A. T., Minshall, R. D., Liu, G. Endothelial cell SHP-2 negatively regulates neutrophil adhesion and promotes transmigration by enhancing ICAM-1-VE-cadherin interaction.

Increased thalamic gray matter volume induced by repetitive transcranial magnetic stimulation treatment in patients with major depressive disorder.

Purpose: Repetitive transcranial magnetic stimulation (rTMS) is an effective therapy in improving depressive symptoms in MDD patients, but the intrinsic mechanism is still unclear. In this study, we investigated the influence of rTMS on brain gray matter volume for alleviating depressive symptoms in MDD patients using structural magnetic resonance imaging (sMRI) data. Methods: Patients with first episode, unmedicated patients with MDD (n = 26), and healthy controls (n = 31) were selected for this study. Depressive symptoms were assessed before and after treatment by using the HAMD-17 score. High-frequency rTMS treatment was conducted in patients with MDD over 15 days. The rTMS treatment target is located at the F3 point of the left dorsolateral prefrontal cortex. Structural magnetic resonance imaging (sMRI) data were collected before and after treatment to compare the changes in brain gray matter volume. Results: Before treatment, patients with MDD had significantly reduced gray matter volumes in the right fusiform gyrus, left and right inferior frontal gyrus (triangular part), left inferior frontal gyrus (orbital part), left parahippocampal gyrus, left thalamus, right precuneus, right calcarine fissure, and right median cingulate gyrus compared with healthy controls (P < 0.05). After rTMS treatment, significant growth in gray matter volume of the bilateral thalamus was observed in depressed patients (P < 0.05). Conclusion: Bilateral thalamic gray matter volumes were enlarged in the thalamus of MDD patients after rTMS treatment and may be the underlying neural mechanism for the treatment of rTMS on depression.

Multiplexed detection and the establishment of a novel high-throughput method for human germ cell quality screening based on aggregation-induced emission.

We report a rapid, sensitive, and high-throughput method for quality control of human sperm cells and oocytes staining based on the aggregation-induced emission feature of the tetraphenylethylene-based luminogen (TPE-Ph-In), which is mitochondria-specific. Germ cells are evaluated to assess fertility and to facilitate assisted reproduction. In regular clinical practice, sperm quality is determined on the basis of visual examination and mathematical models of the sperm cell number, motility, and morphology. The maturation of the oocyte is crucial for the developmental competence of the resulting embryo. Human in vitro fertilization (IVF) have indicated that delaying insemination improves fertilization rates, presumably by allowing the completion of cytoplasmic maturation for those oocytes that have not completely matured at the time. Therefore, a more reliable method to determine germ cell quality is needed. The mitochondrial membrane potential (MMP) of spermatozoa reflects the function and status of those cells. In oocytes, the distribution of mitochondria indicates the readiness of the cell for fertilization. Aggregation-induced emission luminogens (AIEgens) have good biocompatibility and photostability and produce low levels of background signal. There are about 100,000 mitochondria per fully-grown human oocyte. Mitochondria in mammalian oocytes are spherical with little cristae, supplying large scale of ATP for embryo development. Here, we expanded the use of TPE-Ph-Into determine germ cell quality on the basis of the MMP and the intracellular distribution of mitochondria. We stained clinical sperm samples from 36 patients with infertility, as well as four oocytes, with TPE-Ph-In and examined the cells by confocal microscopy and cell sorting analysis. Our results showed a positive correlation between the MMP and sperm cell motility, as well as the different distribution of mitochondria in oocyte. Thus, staining with TPE-Ph-In could be used to quickly determine germ cell quality in vivo, bringing new possibilities for applications of AIEgens in biomedical research and clinical trials.

Testosterone regulates 3T3-L1 pre-adipocyte differentiation and epididymal fat accumulation in mice through modulating macrophage polarization.

Low testosterone levels are strongly related to obesity in males. The balance between the classically M1 and alternatively M2 polarized macrophages also plays a critical role in obesity. It is not clear whether testosterone regulates macrophage polarization and then affects adipocyte differentiation. In this report, we demonstrate that testosterone strengthens interleukin (IL) -4-induced M2 polarization and inhibits lipopolysaccharide (LPS)-induced M1 polarization, but has no direct effect on adipocyte differentiation. Cellular signaling studies indicate that testosterone regulates macrophage polarization through the inhibitory regulative G-protein (Gαi) mainly, rather than via androgen receptors, and phosphorylation of Akt. Moreover, testosterone inhibits pre-adipocyte differentiation induced by M1 macrophage medium. Lowering of serum testosterone in mice by injecting a luteinizing hormone receptor (LHR) peptide increases epididymal white adipose tissue. Testosterone supplementation reverses this effect. Therefore, our findings indicate that testosterone inhibits pre-adipocyte differentiation by switching macrophages to M2 polarization through the Gαi and Akt signaling pathways.

MicroRNA-22 regulates inflammation and angiogenesis via targeting VE-cadherin.

The vascular endothelial (VE)-cadherin functions as an endothelial barrier protein controlling endothelial permeability and leukocyte transmigration. Developmental studies indicate that VE-cadherin also plays a vital role in angiogenesis. MicroRNA-22 plays important roles in cardiovascular diseases including cardiac hypertrophy and heart failure. We identified that miR-22 interacts with VE-cadherin mRNA. Overexpression of miR-22 in endothelial cells increases the synthesis of proinflammatory cytokines. Injection of miR-22 results in increased myeloperoxidase activity in the mouse lungs. Moreover, miR-22 injection into the fluorescent-labeled transgenic zebrafish Tg(fli1:EGFP) embryos caused defective vascular development in the dorsal and intersegmental vessels, and vascular markers were significantly suppressed in these embryos. Our studies demonstrate that the conserved targeting of VE-cadherin by miR-22 regulates endothelial inflammation, tissue injury, and angiogenesis.

Biodegradable three-dimension micro-device delivering 5-fluorouracil in tumor bearing mice.

A novel three-dimension micro-device was formulated to control delivery of 5-fluorouracil (5-FU) for the treatment of solid tumors. The poly-(lactic-co-glycolic) acid (PLGA), which is both biocompatible and biodegradable, was used as carrier material. The characteristics of drug release in vitro and in vivo and the performance of the micro-device after implantation in tumor bearing mice were evaluated. A constant release profile from in vitro test was obtained for a period of 7 days, and it correlated well with the in vivo release profile. In the distribution experiment of 5-FU micro-device, it was demonstrated that 5-FU remained in the tumor tissues for more than 7 days after implantation. Likewise, we found that the 5-FU concentration in tumor correlated well with the in vivo release. Tumors treated with 5-FU loaded micro-device of three different dosages showed significant tumor reduction (P < 0.05) compared with empty control micro-device 7 days after administration. Moreover, the implantation treatment showed enhanced efficacy compared with the intraperitoneal administration with the same dosage. These results suggested that the three-dimensional micro-device may provide a promising local and controlled release drug delivery system, which may enable delivery of multiple drugs for post-surgical chemotherapy against solid tumor.