Coordinated development of brain stem and spinal target neurons is pivotal for the emergence of a precisely functioning locomotor system. Signals that match the development of these far-apart regions of the central nervous system may be redeployed during spinal cord regeneration. Here we show that descending dopaminergic projections from the brain promote motor neuron generation at the expense of V2 interneurons in the developing zebrafish spinal cord by activating the D4a receptor, which acts on the hedgehog pathway. Inhibiting this essential signal during early neurogenesis leads to a long-lasting reduction of motor neuron numbers and impaired motor responses of free-swimming larvae. Importantly, during successful spinal cord regeneration in adult zebrafish, endogenous dopamine promotes generation of spinal motor neurons, and dopamine agonists augment this process. Hence, we describe a supraspinal control mechanism for the development and regeneration of specific spinal cell types that uses dopamine as a signal.

The histaminergic and hypocretin/orexin (hcrt) neurotransmitter systems play crucial roles in alertness/wakefulness in rodents. We elucidated the role of histamine in wakefulness and the interaction of the histamine and hcrt systems in larval zebrafish. Translation inhibition of histidine decarboxylase (hdc) with morpholino oligonucleotides (MOs) led to a behaviorally measurable decline in light-associated activity, which was partially rescued by hdc mRNA injections and mimicked by histamine receptor H1 (Hrh1) antagonist pyrilamine treatment. Histamine-immunoreactive fibers targeted the dorsal telencephalon, an area that expresses histamine receptors hrh1 and hrh3 and contains predominantly glutamatergic neurons. Tract tracing with DiI revealed that projections from dorsal telencephalon innervate the hcrt and histaminergic neurons. Translation inhibition of hdc decreased the number of hcrt neurons in a Hrh1-dependent manner. The reduction was rescued by overexpression of hdc mRNA. hdc mRNA injection alone led to an up-regulation of hcrt neuron numbers. These results suggest that histamine is essential for the development of a functional and intact hcrt system and that histamine has a bidirectional effect on the development of the hcrt neurons. In summary, our findings provide evidence that these two systems are linked both functionally and developmentally, which may have important implications in sleep disorders and narcolepsy. development via histamine receptor H1 in zebrafish.

Tyrosine hydroxylase (TH) is a rate-limiting enzyme in the biosynthesis of catecholamines. In zebrafish, two genes encoding TH have been identified. We cloned them and studied their expression in zebrafish. In adult tissues, th1 mRNA was more abundant than th2 mRNA in the brain and eyes, whereas th2 mRNA was more abundant in the liver, kidney, heart and gills. In developing brain, th1 mRNA was readily detected at 1 day post-fertilization using qPCR and in situ hybridization, whereas th2 mRNA appeared later. th1 was found in 17 catecholaminergic groups in larval brain, whereas th2 was found in four additional groups. A monoclonal antibody commonly used against TH detected preferentially TH1 protein. The two th genes, probably originated as a result of genome duplication, thus show complementary expression, although th1 is predominant in the brain and th2 in the periphery. th2 may be a novel essential factor in regulation of catecholamine synthesis in zebrafish.

BackgroundTriple negative breast cancer (TNBC) lacks both early detection biomarkers and viable targeted therapeutics. Moreover, chemotherapy only produces 20–30% pathologic complete response. Because miRNAs are frequently dysregulated in breast cancer and have broad tissue effects, individual or combinations of circulating miRNAs may serve as ideal diagnostic, predictive or prognostic biomarkers, as well as therapeutic targets. Understanding the role and mechanism of dysregulated miRNAs in TNBC may help to develop novel diagnostic and prognostic strategy for TNBC patients.MethodsThe miRNA array profiles of 1299 breast cancer patients were collected from the Metabric database and subjected to analysis of the altered miRNAs between TNBC and non-TNBC. In Student’s t-test and Kaplan-Meier analysis, four upregulated miRNAs correlated with poor survival in TNBC but not in non-TNBC. Four miRNAs were manipulated in multiple cell lines to investigate their functional role in carcinogenesis. From these results, we studied miR-105 and miR-93-3p in greater detail. The level of miR-105 and miR-93-3p were evaluated in 25 breast cancer tumor tissues. In addition, the diagnostic utility of circulating miR-105 and miR-93-3p were examined in 12 normal and 118 breast cancer plasma samples by ROC curve construction.ResultsmiR-105 and miR-93-3p were upregulated and correlated with poor survival in TNBC patients. Both miR-105 and miR-93-3p were found to activate Wnt/β-catenin signaling by downregulation of SFPR1. By this action, stemness, chemoresistance, and metastasis were promoted. Importantly, the combination of circulating miR-105/93-3p may serve as a powerful biomarker for TNBC, even in early-stage disease.ConclusionsmiR-105/93-3p activates Wnt/β-catenin signaling by downregulating SFRP1 and thereby promotes stemness, chemoresistance, and metastasis in TNBC cells. Most importantly, combined circulating miR-105/93-3p levels represent a prime candidate for development into a diagnostic biomarker for both early- and late-stage TNBC.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-017-0918-2) contains supplementary material, which is available to authorized users.

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Autosomal recessively inherited glucocerebrosidase 1 (GBA1) mutations cause the lysosomal storage disorder Gaucher's disease (GD). Heterozygous GBA1 mutations (GBA1+/−) are the most common risk factor for Parkinson's disease (PD). Previous studies typically focused on the interaction between the reduction of glucocerebrosidase (enzymatic) activity in GBA1+/− carriers and alpha-synuclein-mediated neurotoxicity. However, it is unclear whether other mechanisms also contribute to the increased risk of PD in GBA1+/− carriers. The zebrafish genome does not contain alpha-synuclein (SNCA), thus providing a unique opportunity to study pathogenic mechanisms unrelated to alpha-synuclein toxicity. Here we describe a mutant zebrafish line created by TALEN genome editing carrying a 23 bp deletion in gba1 (gba1c.1276_1298del), the zebrafish orthologue of human GBA1. Marked sphingolipid accumulation was already detected at 5 days post-fertilization with accompanying microglial activation and early, sustained up-regulation of miR-155, a master regulator of inflammation. gba1c.1276_1298del mutant zebrafish developed a rapidly worsening phenotype from 8 weeks onwards with striking reduction in motor activity by 12 weeks. Histopathologically, we observed marked Gaucher cell invasion of the brain and other organs. Dopaminergic neuronal cell count was normal through development but reduced by >30% at 12 weeks in the presence of ubiquitin-positive, intra-neuronal inclusions. This gba1c.1276_1298del zebrafish line is the first viable vertebrate model sharing key pathological features of GD in both neuronal and non-neuronal tissue. Our study also provides evidence for early microglial activation prior to alpha-synuclein-independent neuronal cell death in GBA1 deficiency and suggests upregulation of miR-155 as a common denominator across different neurodegenerative disorders.

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The surgical outcome for the patients with multiple HCC's and vascular invasion was poor. Our study showed adjuvant HAIC was beneficial in these patients and formed the basis for further randomized controlled trials.