The significance of Notch ligand expression in the peripheral blood of children with hand, foot and mouth disease (HFMD).

BACKGROUND: Hand, foot and mouth disease (HFMD), a virus-induced infectious disease that usually affects infants and children, has an increased incidence in China in recent years. This study attempted to investigate the role of the Notch signaling pathway in the pathogenesis of HFMD. METHODS: Eighty-two children diagnosed with HFMD were enrolled into this study. The HFMD group was further divided into the uncomplicated HFMD and HFMD with encephalitis groups. The control group included 40 children who underwent elective surgery for treatment of inguinal hernias. RESULTS: Children with HFMD displayed significantly reduced CD3+, CD3+CD4+ and CD3+CD8+ cell subsets, but substantially enhanced CD3-CD19+ cell subset (p<0.05 versus control subjects). The expression levels of Notch ligands Dll1 and Dll4 in the peripheral blood of the HFMD group were significantly higher than those in the control group (p<0.05). There were statistically significant differences in CD3+, CD3+CD4+ and CD3-CD19+ cell subsets, but not in Notch ligand expression, between the uncomplicated HFMD and HFMD with encephalitis groups. Dll4 expression in HFMD subjects correlated negatively with the CD3+ and CD3+CD8+ cell subsets (p<0.05), but positively with the CD3-CD19+ cell subset (p<0.05). Furthermore, Dll4 expression in HFMD with encephalitis subjects correlated positively with total white blood cell (WBC) counts and total protein contents in cerebrospinal fluid (CSF) (p<0.05). CONCLUSIONS: The Notch ligand Dll4 exhibits a strong correlation with the CD3+, CD3+CD8+ and CD3-CD19+ cell subsets in children with HFMD, indicating that the Notch signaling may be involved in the development of HFMD by affecting the number and status of peripheral lymphocytes.

Polydopamine nanoparticles for the treatment of acute inflammation-induced injury.

Nanotechnology-mediated anti-inflammatory therapy is emerging as a novel strategy for the treatment of inflammation-induced injury. However, one of the main hurdles for these anti-inflammatory nano-drugs is their potential toxic side effects in vivo. Herein, we uncovered that polydopamine (PDA) nanoparticles with their structure and chemical properties similar to melanin, a natural bio-polymer, displayed a significant anti-inflammation therapeutic effect on acute inflammation-induced injury. PDA with enriched phenol groups functioned as a radical scavenger to eliminate reactive oxygen species (ROS) generated during inflammatory responses. As revealed by in vivo photoacoustic imaging with a H2O2-specific nanoprobe, PDA nanoparticles remarkably reduced intracellular ROS levels in murine macrophages challenged with either H2O2 or lipopolysaccharide (LPS). The anti-inflammatory capacity of PDA nanoparticles was further demonstrated in murine models of both acute peritonitis and acute lung injury (ALI), where diminished ROS generation, reduced proinflammatory cytokines, attenuated neutrophil infiltration, and alleviated lung tissue damage were observed in PDA-treated mice after a single dose of PDA treatment. Our work therefore presents the great promise of PDA nanoparticles as a biocompatible nano-drug for anti-inflammation therapy to treat acute inflammation-induced injury.

Human amniotic fluid stem cells labeled with up-conversion nanoparticles for imaging-monitored repairing of acute lung injury.

Human amniotic fluid stem (hAFS) cells have generated a great deal of excitement in cell-based therapies and regenerative medicine. Here, we examined the effect of hAFS cells labeled with dual-polymer-coated UCNP-PEG-PEI nanoparticles in a murine model of acute lung injury (ALI). We observed hAFS cells migration to the lung using highly sensitive in vivo upconversion luminescence (UCL) imaging. We demonstrated that hAFS cells remained viable and retained their ability to differentiate even after UCNP-PEG-PEI labeling. More importantly, hAFS cells displayed remarkable positive effects on ALI-damaged lung tissue repair compared with mouse bone marrow mesenchymal stem cells (mBMSCs), which include recovery of the integrity of alveolar-capillary membrane, attenuation of transepithelial leukocyte and neutrophil migration, and down-regulation of proinflammatory cytokine and chemokine expression. Our work highlights a promising role for imaging-guided hAFS cell-based therapy in ALI.