The evolutionarily conserved choroid plexus contributes to the homeostasis of brain ventricles in zebrafish.

The choroid plexus (ChP) produces cerebrospinal fluid (CSF). It also contributes to brain development and serves as the CSF-blood barrier. Prior studies have identified transporters on the epithelial cells that transport water and ions from the blood vasculature to the ventricles and tight junctions involved in the CSF-blood barrier. Yet, how the ChP epithelial cells control brain physiology remains unresolved. We use zebrafish to provide insights into the physiological roles of the ChP. Upon histological and transcriptomic analyses, we identify that the zebrafish ChP is conserved with mammals and expresses transporters involved in CSF secretion. Next, we show that the ChP epithelial cells secrete proteins into CSF. By ablating the ChP epithelial cells, we identify a reduction of the ventricular sizes without alterations of the CSF-blood barrier. Altogether, our findings reveal that the zebrafish ChP is conserved and contributes to the size and homeostasis of the brain ventricles.

The forkhead transcription factor Foxj1 controls vertebrate olfactory cilia biogenesis and sensory neuron differentiation.

In vertebrates, olfactory receptors localize on multiple cilia elaborated on dendritic knobs of olfactory sensory neurons (OSNs). Although olfactory cilia dysfunction can cause anosmia, how their differentiation is programmed at the transcriptional level has remained largely unexplored. We discovered in zebrafish and mice that Foxj1, a forkhead domain-containing transcription factor traditionally linked with motile cilia biogenesis, is expressed in OSNs and required for olfactory epithelium (OE) formation. In keeping with the immotile nature of olfactory cilia, we observed that ciliary motility genes are repressed in zebrafish, mouse, and human OSNs. Strikingly, we also found that besides ciliogenesis, Foxj1 controls the differentiation of the OSNs themselves by regulating their cell type-specific gene expression, such as that of olfactory marker protein (omp) involved in odor-evoked signal transduction. In line with this, response to bile acids, odors detected by OMP-positive OSNs, was significantly diminished in foxj1 mutant zebrafish. Taken together, our findings establish how the canonical Foxj1-mediated motile ciliogenic transcriptional program has been repurposed for the biogenesis of immotile olfactory cilia, as well as for the development of the OSNs.

Protective effect of alpha-lipoic acid and epalrestat on oxaliplatin-induced peripheral neuropathy in zebrafish.

INTRODUCTION/AIMS: Oxaliplatin is a platinum-based anti-cancer drug widely used in colorectal cancer patients, but it may cause peripheral neuropathy. As one of the main causes of oxaliplatin-induced peripheral neuropathy (OPN) is oxidative stress, which is also a key factor causing diabetic peripheral neuropathy (DPN), the aim of this study was to evaluate the preventive effects of alpha-lipoic acid (ALA) and epalrestat (EP), which are used for the treatment of DPN, in an OPN zebrafish model. METHODS: Tg(nbt:dsred) transgenic zebrafish, with sensory nerves in the peripheral lateral line, were treated with oxaliplatin, oxaliplatin/EP, and oxaliplatin/ALA for 4 days. A confocal microscope was used to visualize and quantify the number of axon bifurcations in the distal nerve ending. To analyze the formation of synapses on sensory nerve terminals, quantification of membrane-associated guanylate kinase (MAGUK) puncta was performed using immunohistochemistry. RESULTS: The number of axon bifurcations and intensity of MAGUK puncta were significantly reduced in the oxaliplatin-treated group compared with those in the embryo medium-treated group. In both the oxaliplatin/EP and oxaliplatin/ALA-treated groups, the number of axon bifurcations and intensity of MAGUK puncta were greater than those in the oxaliplatin-treated group (p < .0001), and no significant difference was observed between larvae treated with oxaliplatin/ALA 1 µM and oxaliplatin/EP 1 µM (p = .4292). DISCUSSION: ALA and EP have protective effects against OPN in zebrafish. Our findings show that ALA and EP can facilitate more beneficial treatment for OPN.

Neuro-Restorative Effect of Nimodipine and Calcitriol in 1-Methyl 4-Phenyl 1,2,3,6 Tetrahydropyridine-Induced Zebrafish Parkinson's Disease Model.

Objective: Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The treatment of PD aims to alleviate motor symptoms by replacing the reduced endogenous dopamine. Currently, there are no disease-modifying agents for the treatment of PD. Zebrafish (Danio rerio) have emerged as an effective tool for new drug discovery and screening in the age of translational research. The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to cause a similar loss of dopaminergic neurons in the human midbrain, with corresponding Parkinsonian symptoms. L-type calcium channels (LTCCs) have been implicated in the generation of mitochondrial oxidative stress, which underlies the pathogenesis of Parkinson's disease. Therefore, we investigated the neuro-restorative effect of LTCC inhibition in an MPTP-induced zebrafish PD model and suggested a possible drug candidate that might modify the progression of PD. Methods: All experiments were conducted using a line of transgenic zebrafish, Tg (dat:EGFP), in which green fluorescent protein (GFP) is expressed in dopaminergic neurons. The experimental groups were exposed to 500µã– MPTP from 1 to 3 days post fertilization (dpf). The drug candidates: Levodopa 1m㏖, Nifedipine 10µã–, Nimodipine 3.5 µã–, Diethylstilbestrol 0.3 µã–, Luteolin 100 µã–, Cacitriol 0.25 µã– were exposed from 3 to 5 dpf. Locomotor activity was assessed by automated tracking and dopaminergic neurons were visualized in vivo by confocal microscopy. Results: Levodopa, Nimodipine, Diethylstilbestrol, and Calcitriol had significant positive effects on the restoration of motor behavior, which was damaged by MPTP. Nimodipine and Calcitriol have significant positive effects on the restoration of dopaminergic neurons, which were reduced by MPTP. Through locomotor analysis and dopaminergic neuron quantification, we identified the neuro-restorative effects of Nimodipine and Calcitriol in Zebrafish MPTP-induced PD model. Conclusion: The present study identified the neuro-restorative effects of nimodipine and calcitriol in an MPTP-induced zebrafish model of Parkinson's disease. They restored dopaminergic neurons which were damaged due to the effects of MPTP and normalized the locomotor activity. LTCCs have potential pathological roles in neurodevelopmental and neurodegenerative disorders. Zebrafish are highly amenable to high-throughput drug screening and might, therefore, be a useful tool to work towards the identification of disease-modifying treatment for PD. Further studies including zebrafish genetic models to elucidate the mechanism of action of the disease-modifying candidate by investigating Ca2+ influx and mitochondrial function in dopaminergic neurons, are needed to reveal the pathogenesis of PD and develop disease-modifying treatments for PD.

Label-free adaptive optics single-molecule localization microscopy for whole zebrafish.

Specimen-induced aberration has been a major factor limiting the imaging depth of single-molecule localization microscopy (SMLM). Here, we report the application of label-free wavefront sensing adaptive optics to SMLM for deep-tissue super-resolution imaging. The proposed system measures complex tissue aberrations from intrinsic reflectance rather than fluorescence emission and physically corrects the wavefront distortion more than three-fold stronger than the previous limit. This enables us to resolve sub-diffraction morphologies of cilia and oligodendrocytes in whole zebrafish as well as dendritic spines in thick mouse brain tissues at the depth of up to 102 µm with localization number enhancement by up to 37 times and localization precision comparable to aberration-free samples. The proposed approach can expand the application range of SMLM to whole zebrafish that cause the loss of localization number owing to severe tissue aberrations.

Mechanism of Bisphenol F Affecting Motor System and Motor Activity in Zebrafish.

Bisphenol F (BPF; 4,4'-dihydroxydiphenylmethane) is one of the most frequently used compounds in the manufacture of plastics and epoxy resins. Previous studies have demonstrated that BPF affects locomotor behavior, oxidative stress, and neurodevelopment in zebrafish. However, its neurotoxic effects are controversial, and the underlying mechanisms are unclear. In order to determine whether BPF affects the motor system, we exposed zebrafish embryos to BPF and assessed behavioral, histological, and neurochemical changes. Spontaneous locomotor behavior and startle response were significantly decreased in BPF-treated zebrafish larvae compared with control larvae. BPF induced motor degeneration and myelination defects in zebrafish larvae. In addition, embryonic exposure to BPF resulted in altered metabolic profiles of neurochemicals, including neurotransmitters and neurosteroids, which may impact locomotion and motor function. In conclusion, exposure to BPF has the potential to affect survival, motor axon length, locomotor activity, myelination, and neurochemical levels of zebrafish larvae.

Radioprotective effect of mistletoe extract on intestinal toxicity: in vivo study using adult zebrafish.

PURPOSE: The intestine is a dose-limiting organ in the treatment of intra-abdominal cancer. We previously reported that the extract of mistletoe parasites on Quercus had a more potent radioprotective effect than amifostine in reducing the developmental toxicities of zebrafish embryos. In this study, radioprotection against intestinal toxicity was investigated in adult zebrafish. METHODS: Wild-type adult AB zebrafish were exposed to 45-50 Gy of photon beam irradiation and/or treated with mistletoe extract orally 1 h before. The main endpoints of the study were survival and degree of deformation of the intestinal villi. RESULTS: The median follow-up period was 10 d post-irradiation (range: 7-11 d). A total of 105 zebrafish were used, including 42 in the radiation alone, 42 in the radiation and mistletoe arms, and 21 control subjects (mistletoe alone, mock-irradiated arm). The rate of both significant deformity and death was 53% in the radiation-alone arm, whereas the corresponding rate was 30% in the radiation and mistletoe arms. Significant deformity-free survival rates at 10 d post-irradiation in the radiation alone, and radiation and mistletoe arms were 44.7% (95% confidence interval [CI]:20-54.3) and 68.4% (95% CI:53.8-86.8), respectively (p=.046). The radiation and mistletoe arms showed decreased expression of two of three inflammatory genes (IL-1ß and IL-6) compared to the radiation alone group (p<.05). CONCLUSION: The radioprotective effect against intestinal toxicity was successfully shown in an adult zebrafish model. This result suggests the possibility of clinical use of mistletoe extract for the treatment of abdominal cancers.

Tamalin Function Is Required for the Survival of Neurons and Oligodendrocytes in the CNS.

Tamalin is a post-synaptic scaffolding protein that interacts with group 1 metabotropic glutamate receptors (mGluRs) and several other proteins involved in protein trafficking and cytoskeletal events, including neuronal growth and actin reorganization. It plays an important role in synaptic plasticity in vitro by controlling the ligand-dependent trafficking of group 1 mGluRs. Abnormal regulation of mGluRs in the central nervous system (CNS) is associated with glutamate-mediated neurodegenerative disorders. However, the pathological consequences of tamalin deficiency in the CNS are unclear. In this study, tamalin knockout (KO) zebrafish and mice exhibited neurodegeneration along with oligodendrocyte degeneration in the post-embryonic CNS to adulthood without any developmental defects, thus suggesting the function of tamalin is more important in the postnatal stage to adulthood than that in CNS development. Interestingly, hypomyelination was independent of axonal defects in the CNS of tamalin knockout zebrafish and mice. In addition, the loss of Arf6, a downstream signal of tamalin scaffolding protein, synergistically induced neurodegeneration in tamalin KO zebrafish even in the developing CNS. Furthermore, tamalin KO zebrafish displayed increased mGluR5 expression. Taken together, tamalin played an important role in neuronal and oligodendrocyte survival and myelination through the regulation of mGluR5 in the CNS.

Mechanism of action and neurotoxic effects of chronic exposure to bisphenol F in adult zebrafish.

Although bisphenol F (BPF), the main replacement for bisphenol A, has been commonly used in polycarbonate production, its neurotoxicity and the underlying mechanisms remain poorly understood. To address this knowledge gap, this study aimed to assess the neurotoxicity caused by chronic exposure to BPF and to identify its underlying mechanisms. We exposed adult zebrafish chronically to BPF at environmentally relevant concentrations (0.001, 0.01, and 0.1 mg/L) for 4 weeks. The results revealed that with BPF crossing the blood-brain barrier and bioaccumulating in brain tissues, chronic exposure to BPF resulted in anxiety-like behaviors and disruptions in learning and memory function in adult zebrafish. Furthermore, BPF toxicity in the zebrafish brain involved the dysregulation of metabolic pathways for choline and kynurenine in neurotransmitter systems and for 17ß-estradiol, cortisol, pregnenolone-sulfate, and Dehydroepiandrosterone (DHEA)-sulfate in neurosteroid systems. RNA-seq analysis revealed that BPF exposure affected metabolic pathways, calcium signaling pathways, neuroactive ligand-receptor interactions, tight junctions, gap junctions, and the gonadotropin-releasing hormone signaling pathway. Our results indicate that chronic exposure to BPF alters the neurochemical profile of the brain and causes neurobehavioral effects, such as anxiety and cognitive decline. Overall, the multimodal approach, including behavioral and neurochemical profiling technologies, has great potential for the comprehensive assessment of potential risks posed by environmental pollutants to human and ecosystem health.

Chronic exposure to butyl-paraben causes photosensitivity disruption and memory impairment in adult zebrafish.

Limited studies on neurotoxicity following chronic exposure to butyl­paraben (BuP) have been conducted. In this study, neurobehavior in zebrafish adults was assessed using the novel tank test, photomotor response test, and T-maze test after exposure to BuP for 28 days at concentrations of 0, 0.01, 0.1, and 1.0 mg/L. To comprehensively understand the underlying molecular perturbations in the brain, alterations in transcripts, neurotransmitters, and neurosteroids were measured. We found that BuP penetrated the blood-brain barrier and impaired neurobehavior in photosensitivity at 1.0 mg/L and in memory at 0.1 and 1.0 mg/L. RNA-seq analysis showed that phototransduction, tight junctions, and neuroactive ligand receptor activity were significantly affected, which explains the observed abnormal neurobehaviors. Neurosteroid analysis revealed that BuP increased cortisol levels in a concentration-dependent manner and specifically reduced allopregnanolone levels at all tested concentrations, suggesting that cortisol and allopregnanolone are significant neurosteroid markers associated with photosensitivity and memory deficits. Collectively, we demonstrated that BuP can cross the blood-brain and modulate the levels of transcripts, associated with phototransduction and circadian rhythm, and neurosteroidal cortisol and allopregnanolone, resulting in abnormal neurobehavioral responses to light stimulation and learning and memory.

Improved anti-fibrotic effects by combined treatments of simvastatin and NS-398 in experimental liver fibrosis models.

BACKGROUND/AIMS: Efficient anti-fibrotic therapies are required for the treatment of liver cirrhosis. Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) and cyclooxygenase-2 (COX-2) inhibitors have been reported to have anti-fibrotic effects. Here, we investigated whether combined treatment with a statin and a COX-2 inhibitor has synergistic anti-fibrotic effects. METHODS: The effects of treatment strategies incorporating both simvastatin and a COX-2 inhibitor, NS-398, were investigated using an immortalized human hepatic stellate cell line (LX-2) and a hepatic fibrosis mouse model developed using thioacetamide (TAA) in drinking water. Cellular proliferation was investigated via 5-bromo-2-deoxyuridine uptake. Pro- and anti-apoptotic factors were investigated through Western blotting and real-time polymerase chain reaction analysis. RESULTS: The evaluation of the anti-proliferative effects on LX-2 cells showed that the observed effects were more pronounced with combination therapy than with single-drug therapy. Moreover, hepatic fibrosis and collagen deposition decreased significantly in TAA-treated mice in response to the combined treatment strategy. The mechanisms underlying the anti-fibrotic effects of the combination therapy were investigated. The effects of the combination therapy were correlated with increased expression levels of extracellular signal-regulated kinase 1/2 signaling molecules, upregulation of the Bax/Bcl-2 signaling pathway, inhibition of the transforming growth factor-ß signaling pathway, and inhibition of tissue inhibitor of matrix metalloproteinases 1 and 2. CONCLUSION: The combination of simvastatin and NS-398 resulted in a synergistic anti-fibrotic effect through multiple pathways. These findings offer a theoretical insight into the possible clinical application of this strategy for the treatment of advanced liver diseases with hepatic fibrosis.

Noise-induced hearing loss in zebrafish model: Characterization of tonotopy and sex-based differences.

Hearing loss caused by frequent and persistent exposure to loud noise is one of the most common diseases in modern society. Many studies have demonstrated the characteristics of noise-induced hearing loss in human and non-human vertebrate models, including frequency-specific noise-induced hearing loss and sex-biased differences. Zebrafish (Danio rerio) is a useful hearing research model because its lateral line is easy to access and because of its detailed perception of sound. Despite the increasing popularity of zebrafish as a model for NIHL, a better understanding of this model is needed to determine sex differences in NIHL. To study the features of zebrafish as they relate to an NIHL model, we tested various phenotypes after frequency-specific noise stimulation. The degree of damage to hair cells and hearing loss were investigated after exposing zebrafish to 200 Hz and 1 kHz continuous waves and broadband white noise with a bandwidth from 50 Hz to 1 kHz. After exposure to all frequencies, the larvae showed lateral line hair cell damage, which is superficially located. In adult zebrafish, the threshold of auditory-evoked potential signals is elevated. Moreover, the number of hair cells remarkably decreased in the rostral region of the saccule, after exposure to 1 kHz and white noise, whereas zebrafish exposed to 200 Hz noise showed a decrease in hair cells in the caudal region. Moreover, male zebrafish were found to be more vulnerable to noise than female zebrafish, as is the case in humans and other mammals. Cortisol levels also increased in the noise-exposed male group, as compared to the noise-exposed female and control male groups. However, there was no difference in cortisol levels when the noise-exposed female group was compared to the control female group. Our study demonstrates not only that noise-induced hearing loss is frequency-dependent but also that the degree of hearing loss is affected by sex in zebrafish, emphasizing the need to consider sex in NIHL studies.

Transgenic fluorescent zebrafish lines that have revolutionized biomedical research.

Since its debut in the biomedical research fields in 1981, zebrafish have been used as a vertebrate model organism in more than 40,000 biomedical research studies. Especially useful are zebrafish lines expressing fluorescent proteins in a molecule, intracellular organelle, cell or tissue specific manner because they allow the visualization and tracking of molecules, intracellular organelles, cells or tissues of interest in real time and in vivo. In this review, we summarize representative transgenic fluorescent zebrafish lines that have revolutionized biomedical research on signal transduction, the craniofacial skeletal system, the hematopoietic system, the nervous system, the urogenital system, the digestive system and intracellular organelles.

Identification of de novo EP300 and PLAU variants in a patient with Rubinstein-Taybi syndrome-related arterial vasculopathy and skeletal anomaly.

Rubinstein-Taybi syndrome (RSTS) is a human genetic disorder characterized by distinctive craniofacial features, broad thumbs and halluces, and intellectual disability. Mutations in the CREB binding protein (CREBBP) and E1A binding protein p300 (EP300) are the known causes of RSTS disease. EP300 regulates transcription via chromatin remodeling and plays an important role in cell proliferation and differentiation. Plasminogen activator, urokinase (PLAU) encodes a serine protease that converts plasminogen to plasmin and is involved in several biological processes such as the proteolysis of extracellular matrix-remodeling proteins and the promotion of vascular permeability and angiogenesis. Recently, we discovered a patient who presented with RSTS-related skeletal anomaly and peripheral arterial vasculopathy. To investigate the genetic cause of the disease, we performed trio whole genome sequencing of the genomic DNA from the proband and the proband's parents. We identified two de novo variants coined c.1760T>G (p.Leu587Arg) and c.664G>A (p.Ala222Thr) in EP300 and PLAU, respectively. Furthermore, functional loss of EP300a and PLAUb in zebrafish synergistically affected the intersegmental vessel formation and resulted in the vascular occlusion phenotype. Therefore, we hypothesize that the de novo EP300 variant may have caused RSTS, while both the identified EP300 and PLAU variants may have contributed to the patient's vascular phenotype.

Protective effects of alpha-lipoic acid on hair cell damage in diabetic zebrafish model.

Hearing impairment is one of the complications in diabetes mellitus; however, there are very few therapeutic studies on it. In this study, we investigated the protective effect of alpha-lipoic acid (ALA) on hearing loss in diabetic transgenic zebrafish and confirmed that ALA protects the loss of hair cells (HCs) caused by hyperglycemia. The data indicated that ALA has a protective effect on the damage to HCs in diabetic zebrafish.

FAM19A5l Affects Mustard Oil-Induced Peripheral Nociception in Zebrafish.

Family with sequence similarity 19 (chemokine (C-C motif)-like) member A5 (FAM19A5) is a chemokine-like secretory protein recently identified as involved in the regulation of osteoclast formation, post-injury neointima formation, and depression. Although roles for FAM19A5 have been described in nervous system development and psychiatric disorders, its role in the nervous system remains poorly understood. Here, we analyzed the evolutionary history of FAM19A genes in vertebrates and identified FAM19A5l, a paralogous zebrafish gene originating from a common ancestral FAM19A5 gene. Further, zebrafish FAM19A5l is expressed in trigeminal and dorsal root ganglion neurons as well as distinct neuronal subsets of the central nervous system. Interestingly, FAM19A5l+ trigeminal neurons are nociceptive neurons that localized with TRPA1b and TRPV1 and respond to mustard oil treatment. Behavioral analysis further revealed that the nociceptive response to mustard oil decreases in FAM19A5l-knockout zebrafish larvae. In addition, TRPA1b and NGFa mRNA levels are down- and upregulated in FAM19A5l-knockout and -overexpressing transgenic zebrafish, respectively. Together, our data suggest that FAM19A5l plays a role in nociceptive responses to mustard oil by regulating TRPA1b and NGFa expression in zebrafish.

Development of an experimental model for ocular toxicity screening in Zebrafish.

BACKGROUND: To investigate the efficacy of a novel experimental model for exploring visual function using a contrast-optomotor response (C-OMR) assay made by applying the contrast sensitivity test to the OMR assay in zebrafish. METHODS: Zebrafish larvae were treated with 0 (control), 5, 10, or 15 µM gentamicin and digoxin for 24 h at four days post-fertilization (dpf). Zebrafish larvae were assessed using the C-OMR assay with graded contrast gray-white stripes at 5 dpf, and the results were expressed as the percentage of larvae that finished swimming for 30 s (n = 20 per each group). The same C-OMR assay was repeated four times using different larvae. RESULTS: The percentage of larvae that finished swimming within 30 s was significantly reduced in larvae treated with 5, 10, and 15 µM gentamicin and 10 and 15 µM digoxin as compared to the Control groups. The C-OMR assay could distinguish that the decrease in visual function was different depending on the concentration of gentamicin and digoxin (5, 10, and 15 µM), whereas the OMR test with one contrast gray-white stripe could not. CONCLUSIONS: The method of analyzing zebrafish OMR using graded contrast gray-white stripes is more sensitive than the OMR assay alone and may be more useful for assessing the drug toxicity and eye-related diseases to improve the understanding of drug-induced ocular side effects in the clinic.

Dual role of endothelial Myct1 in tumor angiogenesis and tumor immunity.

The cross-talk between angiogenesis and immunity within the tumor microenvironment (TME) is critical for tumor prognosis. While pro-angiogenic and immunosuppressive TME promote tumor growth, anti-angiogenic and immune stimulatory TME inhibit tumor progression. Therefore, there is a great interest in achieving vascular normalization to improve drug delivery and enhance antitumor immunity. However, anti-vascular endothelial growth factor (VEGF) mechanisms to normalize tumor vessels have offered limited therapeutic efficacies for patients with cancer. Here, we report that Myct1, a direct target of ETV2, was nearly exclusively expressed in endothelial cells. In preclinical mouse tumor models, Myct1 deficiency reduced angiogenesis, enhanced high endothelial venule formation, and promoted antitumor immunity, leading to restricted tumor progression. Analysis of The Cancer Genome Atlas (TCGA) datasets revealed a significant (P < 0.05) correlation between MYCT1 expression, angiogenesis, and antitumor immunity in human cancers, as suggested by decreased FOXP3 expression and increased antitumor macrophages in patients with low MYCT1 expression. Mechanistically, MYCT1 interacted with tight junction protein Zona Occludens 1 and regulated Rho GTPase-mediated actin cytoskeleton dynamics, thereby promoting endothelial motility in the angiogenic environment. Myct1-deficient endothelial cells facilitated trans-endothelial migration of cytotoxic T lymphocytes and polarization of M1 macrophages. Myct1 targeting combined with anti-PD1 treatment significantly (P < 0.05) increased complete tumor regression and long-term survival in anti-PD1-responsive and -refractory tumor models in mice. Our data collectively support a critical role for Myct1 in controlling tumor angiogenesis and reprogramming tumor immunity. Myct1-targeted vascular control, in combination with immunotherapy, may become an exciting therapeutic strategy.

Small compounds mimicking the adhesion molecule L1 improve recovery in a zebrafish demyelination model.

Demyelination leads to a loss of neurons, which results in, among other consequences, a severe reduction in locomotor function, and underlies several diseases in humans including multiple sclerosis and polyneuropathies. Considerable clinical progress has been made in counteracting demyelination. However, there remains a need for novel methods that reduce demyelination while concomitantly achieving remyelination, thus complementing the currently available tools to ameliorate demyelinating diseases. In this study, we used an established zebrafish demyelination model to test selected compounds, following a screening in cell culture experiments and in a mouse model of spinal cord injury that was aimed at identifying beneficial functions of the neural cell adhesion molecule L1. In comparison to mammalian nervous system disease models, the zebrafish allows testing of potentially promotive compounds more easily than what is possible in mammals. We found that our selected compounds tacrine and duloxetine significantly improved remyelination in the peripheral and central nervous system of transgenic zebrafish following pharmacologically induced demyelination. Given that both molecules are known to positively affect functions other than those related to L1 and in other disease contexts, we propose that their combined beneficial function raises hope for the use of these compounds in clinical settings.

Cross-Contamination of Enrofloxacin in Veterinary Medicinal and Nutritional Products in Korea.

Poultry meat and eggs are vital sources of protein for human consumption worldwide. The use of several nutritional and medicinal products, including antibiotics, is crucial for efficient and safe poultry production. Accumulation of drug residues in meat and eggs from inappropriate drug use is a major concern to public health. Recently, enrofloxacin was detected (2.4-3.8 ppb) in edible eggs produced in Jeju Island, Korea. Although the farm from which the enrofloxacin-contaminated eggs were collected did not use enrofloxacin-containing products, they reported extensive use of a nutritional product (NPJ). Accordingly, in this study, we investigated whether enrofloxacin contamination had occurred accidentally in various widely used veterinary pharmaceutical products. Enrofloxacin content (4.57-179.08 ppm) in different lots of the NPJ was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Furthermore, 76 veterinary pharmaceutical products that are widely used in poultry farms in Korea and claim to not contain enrofloxacin were collected and analyzed by LC-MS/MS. Among them, a florfenicol product and a sulfatrimethoprime product were found to contain 3.00 and 0.57 ppm enrofloxacin, respectively. These results suggest that appropriate manufacturing standards are not being followed and that strict monitoring of drug manufacturing is necessary in Korea to avoid drug contamination.