Rapid risk assessment models for different types of cigarette smoke extract (CSE) exposure are critical to understanding the etiology of chronic obstructive pulmonary disease. The present study investigated inflammation of cultured tracheal tissues with CSE exposure. Rat trachea rings were isolated, cultured, then exposed to various concentrations of CSE from 3R4 F reference cigarettes for 4 h. Tissue/cellular morphology, ultrastructure, viability and damage, inflammatory cell infiltration, and inflammatory protein levels were measured and compared to untreated controls. Human bronchial epithelial cells (BEAS-2B) exposed to 0 or 300 μg/mL CSE were cocultured with macrophages to assess extent of mobilization and phagocytosis. Endotracheal epithelium cilia densities were significantly reduced with increasing CSE concentrations, while mucous membranes became increasingly disordered; both eventually disappeared. Macrophages became larger as the CSE concentration increased, with microvilli and extended pseudopodium covering their surface, and many primary and secondary lysosomes present in the cytoplasm. Inflammatory cell infiltration also increased with increasing CSE dose, as did intracellular adhesion molecule-1(ICAM-1), interleukin-6(IL-6). The method described here may be useful to qualitatively characterized the effects of the compound under study. Then, we use BEAS-2B cell line system to strength the observation made in the cultured tissues. Probably, an approach to integrate results from both experiments will facilitate its application. These results demonstrate that cultured rat tracheal rings have a whole-tissue structure that undergoes inflammatory processes similar to in vivo tissues upon CSE exposure.

Malignant gliomas exhibit extensive heterogeneity and poor prognosis. Here we identify mitotic Olig2-expressing cells as tumor-propagating cells in proneural gliomas, elimination of which blocks tumor initiation and progression. Intriguingly, deletion of Olig2 resulted in tumors that grow, albeit at a decelerated rate. Genome occupancy and expression profiling analyses reveal that Olig2 directly activates cell-proliferation machinery to promote tumorigenesis. Olig2 deletion causes a tumor phenotypic shift from an oligodendrocyte precursor-correlated proneural toward an astroglia-associated gene expression pattern, manifest in downregulation of platelet-derived growth factor receptor-α and reciprocal upregulation of epidermal growth factor receptor (EGFR). Olig2 deletion further sensitizes glioma cells to EGFR inhibitors and extends the lifespan of animals. Thus, Olig2-orchestrated receptor signaling drives mitotic growth and regulates glioma phenotypic plasticity. Targeting Olig2 may circumvent resistance to EGFR-targeted drugs.

Medulloblastoma, the most common malignant childhood brain tumor, exhibits distinct molecular subtypes and cellular origins. Genetic alterations driving medulloblastoma initiation and progression remain poorly understood. Herein, we identify GNAS, encoding the G protein Gαs, as a potent tumor suppressor gene that, when expressed at low levels, defines a subset of aggressive Sonic hedgehog (SHH)-driven human medulloblastomas. Ablation of the single Gnas gene in anatomically distinct progenitors in mice is sufficient to induce Shh-associated medulloblastomas, which recapitulate their human counterparts. Gαs is highly enriched at the primary cilium of granule neuron precursors and suppresses Shh signaling by regulating both the cAMP-dependent pathway and ciliary trafficking of Hedgehog pathway components. Elevation in levels of a Gαs effector, cAMP, effectively inhibits tumor cell proliferation and progression in Gnas-ablated mice. Thus, our gain- and loss-of-function studies identify a previously unrecognized tumor suppressor function for Gαs that can be found consistently across Shh-group medulloblastomas of disparate cellular and anatomical origins, highlighting G protein modulation as a potential therapeutic avenue.

Cigarette smoke significantly induces oxidative stress, resulting in cardiovascular disease. NRF2, a well-known antioxidative stress response factor, is generally considered to play protective roles in cardiovascular dysfunction triggered by oxidative stress. Interestingly, recent studies reported adverse effects of NRF2 on the cardiovascular system. These unfavourable pathogenic effects of NRF2 need to be further investigated. Our work shows that cigarette smoke extract (CSE)-induced oxidative stress disturbs fibronectin (FN) assembly during angiogenesis. Furthermore, this effect largely depends on hyperactive NRF2-STAT3 signalling, which consequently promotes abnormal FN deposition. Consistently, disruption of this pathway by inhibiting NRF2 or STAT3 prevents CSE-induced FN disorganization and vasculature disruption in human umbilical vein endothelial cells or zebrafish. Taken together, these findings demonstrate the cardiovascular dysfunction caused by CSE from a novel perspective that NRF2-dependent signalling engages in FN disorganization.

A lack of sufficient oligodendrocyte myelination contributes to remyelination failure in demyelinating disorders. miRNAs have been implicated in oligodendrogenesis; however, their functions in myelin regeneration remained elusive. Through developmentally regulated targeted mutagenesis, we demonstrate that miR-219 alleles are critical for CNS myelination and remyelination after injury. Further deletion of miR-338 exacerbates the miR-219 mutant hypomyelination phenotype. Conversely, miR-219 overexpression promotes precocious oligodendrocyte maturation and regeneration processes in transgenic mice. Integrated transcriptome profiling and biotin-affinity miRNA pull-down approaches reveal stage-specific miR-219 targets in oligodendrocytes and further uncover a novel network for miR-219 targeting of differentiation inhibitors including Lingo1 and Etv5. Inhibition of Lingo1 and Etv5 partially rescues differentiation defects of miR-219-deficient oligodendrocyte precursors. Furthermore, miR-219 mimics enhance myelin restoration following lysolecithin-induced demyelination as well as experimental autoimmune encephalomyelitis, principal animal models of multiple sclerosis. Together, our findings identify context-specific miRNA-regulated checkpoints that control myelinogenesis and a therapeutic role for miR-219 in CNS myelin repair.

The development of Dinophysis populations, producers of diarrhetic shellfish toxins, has been attributed to both abiotic (e.g., water column stratification) and biotic (prey availability) factors. An important process to consider is mixotrophy of the Dinophysis species, which is an intensive feeding of the Mesodinium species for nutrients and a benefit from kleptochloroplasts. During the feeding process, the nutritional status in the environment changes due to the preference of Mesodinium and/or Dinophysis for different nutrients, prey cell debris generated by sloppy feeding, and their degradation by micro-organisms changes. However, there is little knowledge about the role of the bacterial community during the co-occurrence of Mesodinium and Dinophysis and how they directly or indirectly interact with the mixotrophs. In this study, laboratory experiments were performed to characterize the environmental changes including those of the prey present, the bacterial communities, and the ambient dissolved nutrients during the co-occurrence of Mesodinium rubrum and Dinophysis acuminata. The results showed that, during the incubation of the ciliate prey Mesodinium with its predator Dinophysis, available dissolved nitrogen significantly shifted from nitrate to ammonium especially when the population of M. rubrum decayed. Growth phases of Dinophysis and Mesodinium greatly affected the structure and composition of the bacterial community. These changes could be mainly explained by both the changes of the nutrient status and the activity of Dinophysis cells. Dinophysis feeding activity also accelerated the decline of M. rubrum and contamination of cultures with okadaic acid, dinophysistoxin-1, and pectenotoxin-2, but their influence on the prokaryotic communities was limited to the rare taxa (<0.1%) fraction. This suggests that the interaction between D. acuminata and bacteria is species-specific and takes place intracellularly or in the phycosphere. Moreover, a majority of the dominant bacterial taxa in our cultures may also exhibit a metabolic flexibility and, thus, be unaffected taxonomically by changes within the Mesodinium-Dinophysis culture system.