A Chemogenetic Tool that Enables Functional Neural Circuit Analysis.

Chemogenetics enables manipulation of neuronal activity in experimental animals. While providing information about the transduced neuron expressing a ligand-activated molecule, chemogenetics does not provide understanding about the antecedent circuit that drives that neuron's activity. For current approaches, this is not feasible, because the activating molecules are not genetically encoded. The insect allatostatin/allatostatin receptor system, a highly specific, powerful inhibitory chemogenetic approach, has this advantage, because the ligand, being a peptide, is genetically encoded. We developed viral vector-based systems to express biologically active allatostatin in neurons in vivo and allatostatin receptors in subpopulations of postsynaptic neurons. We demonstrate that activity-dependent release of allatostatin induces inhibition of allatostatin receptor-expressing neurons. We validate the approach in the vagal viscerosensory system where inhibitory, rather than the usual excitatory, viscerosensory input leads to sustained decreases in baroreceptor reflex sensitivity and bodyweight.

Different fermentation strategies by Schizochytrium mangrovei strain pq6 to produce feedstock for exploitation of squalene and omega-3 fatty acids.

Schizochytrium mangrovei strain PQ6 was investigated for coproduction of docosahexaenoic acid (C22: 6ω-3, DHA) and squalene using a 30-L bioreactor with a working volume of 15 L under various batch and fed-batch fermentation process regimes. The fed-batch process was a more efficient cultivation strategy for achieving higher biomass production rich in DHA and squalene. The final biomass, total lipid, unsaponifiable lipid content, and DHA productivity were 105.25 g · L-1 , 43.40% of dry cell weight, 8.58% total lipid, and 61.66 mg · g-1  · L-1 , respectively, after a 96 h fed-batch fermentation. The squalene content was highest at 48 h after feeding glucose (98.07 mg · g-1 of lipid). Differences in lipid accumulation during fermentation were correlated with changes in ultrastructure using transmission electron microscopy and Nile Red staining of cells. The results may be of relevance to industrial-scale coproduction of DHA and squalene in heterotrophic marine microalgae such as Schizochytrium.

Stratification of Pancreatic Ductal Adenocarcinoma: Combinatorial Genetic, Stromal, and Immunologic Markers.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is associated with an immunosuppressive milieu that supports immune system evasion and disease progression. Here, we interrogated genetic, stromal, and immunologic features of PDAC to delineate impact on prognosis and means to more effectively employ immunotherapy.Experimental Design: A cohort of 109 PDAC cases annotated for overall survival was utilized as a primary discovery cohort. Gene expression analysis defined immunologic subtypes of PDAC that were confirmed in the Cancer Genome Atlas dataset. Stromal and metabolic characteristics of PDAC cases were evaluated by histologic analysis and immunostaining. Enumeration of lymphocytes, as well as staining for CD8, FOXP3, CD68, CD163, PDL1, and CTLA4 characterized immune infiltrate. Neoantigens were determined by analysis of whole-exome sequencing data. Random-forest clustering was employed to define multimarker subtypes, with univariate and multivariate analyses interrogating prognostic significance.Results: PDAC cases exhibited distinct stromal phenotypes that were associated with prognosis, glycolytic and hypoxic biomarkers, and immune infiltrate composition. Immune infiltrate was diverse among PDAC cases and enrichment for M2 macrophages and select immune checkpoints regulators were specifically associated with survival. Composite analysis with neoantigen burden, immunologic, and stromal features defined novel subtypes of PDAC that could have bearing on sensitivity to immunologic therapy approaches. In addition, a subtype with low levels of neoantigens and minimal lymphocyte infiltrate was associated with improved overall survival.Conclusions: The mutational burden of PDAC is associated with distinct immunosuppressive mechanisms that are conditioned by the tumor stromal environment. The defined subtypes have significance for utilizing immunotherapy in the treatment of PDAC. Clin Cancer Res; 23(15); 4429-40. ©2017 AACR.

Phylogenetic analyses of Prorocentrum spp. and Alexandrium spp. isolated from northern coast of Vietnam based on 18S rDNA sequence.

Some species of marine dinoflagellates belonging to genera Alexandrium and Prorocentrum have been responsible for paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP), respectively Morphological and molecular studies of 4 species including Alexandrium sp. 5, Alexandrium sp. 16, Prorocentrum sp. 1 and Prorocentrum sp. 3 that were collected in Northern coast of Vietnam were presented for the first time. By morphologic observations, we identifiedAlexandrium sp. 5 and Alexandrium sp. 16 as Alexandrium minutum, Alexandrium affine, respectively; Prorocentrum sp. 1 and Prorocentrum sp. 3 as Prorocentrum mexicanum. Sequence data from the partial 18S riboxomal RNA genes have been used to generate a phylogenetic framework with database of GenBank. The obtained results of phylogenetic analyses of species of Prorocentrum spp. and Alexandrium spp. based on 18S rDNA sequences are similar to morphological observations. Thus, molecular tool would be helpful for the identification of dinoflagellate species and further taxonomic studies in Vietnam.