Retinal microstructure and developmental characteristics in Zebrafish / 解剖学报

Objective To study the microscopic structure and morphological characteristics of Zebrafish eyeball and retina at different developmental stages, and to lay a foundation for visual research model. Methods Select eight groups of zebrafish at different ages, with six fish in each group, 48 fish in total. Optical microscopy and transmission electron microscopy were used to observe the eyeball structure of Zebrafish at different developmental stages, and the thickness of retinal each layer was measured to analyze the temporal and spatial development pattern. The morphological characteristics of various cells in the retina and the way of nerve connection were observed from the microscopic and ultrastructural aspects, especially the structural differences between rod cells and cone cells. Results The retina of Zebrafish can be divided into ten layers including retinal pigment epithelial layer, rod cells and cone cells layer, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, inner limiting membrane. Rod cells had a smaller nucleus and a higher electron density than cone cells. Photoreceptor terminals were neatly arranged in the outer plexiform layer, forming neural connections with horizontal cells and bipolar cells, and several synaptic ribbons are clearly visible within them. In Zebrafish retina, ganglion cell layer and inner plexiform layer are the earliest developed. With the growth and development of Zebrafish, the thickness of rod cells and cone cells layer and retinal pigment epithelial layer gradually increases, and the retinal structure was basically developed in about 10 weeks. Conclusion The retinal structure of Zebrafish is typical, with obvious stratification and highly differentiated nerve cells. There are abundant neural connections in the outer plexiform layer. The ocular development characteristics of Zebrafish are similar to those of most mammals.

Histopathological Profile of Obese Zebrafish Liver after Administration of Red Spinach (Amaranthus tricolor L.)

Aims: Obesity is a non-communicable disease whose prevalence continues to increase every year throughout the world. Obesity contributes to the emergence of several diseases such as type-2 diabetes mellitus, hypertension, cardiovascular disorders, cancer, and non-alcoholic fatty liver. A number of studies report that natural ingredients have the potential to be used as a treatment for obesity while reducing a fatty liver. The aim of this research is to evaluate the activity of red spinach ethanol extract in reducing the accumulation of fatty liver in diet-induced obese zebrafish based on its histopathological profile. Methodology: Zebrafish must be adapted for 2 weeks. After 2 weeks, the zebrafish were divided into 6 groups which included: the normal group (or negative control); the obesity group (positive control group); the standard drug (orlistat with dose 4.5 µg/ml); the EERS group (dose of 50 µg/ml); the EERS group (dose of 100 µg/ml); and the EERS group (dose of 200 µg/ml). For a period of 4 weeks, the normal group received a standard diet. A positive control group received Artemia. The treated group received Artemia which was combined with the administration of red spinach (preventive method). The obese group and extract-treated group were given 60 mg/group/fish in the experimental diet. Results: The results showed that EERS at a dose of 100 µg/ml did not show any fatty liver based on their histopathological profile. The EERS dose of 200 µg/ml is more effective in reducing fatty liver when compared to doses of 50 µg/ml and 100 µg/ml on obese zebrafish. Conclusion: Based on the results of the study, it can be concluded that EERS is very prospective for further research and development as a drug for treating obesity and reducing fatty liver.

Study on Mechanism of Action of Matrine in Treatment of Inflammatory Bowel Disease Based on Zebrafish Model and Network Pharmacology / 中国实验方剂学杂志

ObjectiveTo study the mechanism of matrine in the treatment of inflammatory bowel disease （IBD） based on the zebrafish model and network pharmacology. MethodThe IBD model of zebrafish was established using 2，4，6-trinitro-benzenesulfonicacid （TNBS）， and the intestinal phagocytic function， goblet cell secretion， and neutrophil aggregation were evaluated using neutral red staining， alcian blue staining， and neutrophil number changes. Changes in tumor necrosis factor （TNF）-α and cholecystokinin （CCK） content in zebrafish were determined by using relevant reagent kits. Network pharmacology and molecular docking techniques were used to predict the potential mechanism of matrine in the treatment of IBD. Gene expression of relevant targets was verified through Real-time polymerase chain reaction （Real-time PCR）. ResultCompared with the model group， the matrine administration group can increase the neutral red staining area in a dose-dependent manner and improve intestinal phagocytic function（P<0.05，P<0.01）. It can reduce the staining area of alcian blue and affect the secretion of intestinal goblet cells（P<0.01）. It can reduce the number of neutrophil granulocytes， relieve its aggregation， significantly reduce TNF-α content（P<0.01）， and increase the CCK content. Network pharmacology analysis identifies 28 potential targets for matrine in the treatment of IBD. The top five targets by protein-protein interaction （PPI） network analysis are CHRNA7， DRD1， CHRNA4， SLC6A3， and GRM5. The Kyoto encyclopedia of genes and genomes （KEGG） results show that the treatment of IBD with matrine may be related to neuroactive ligand-receptor interaction， cholinergic synapse， and neutrophil extracellular trap formation. Real-time PCR results show that matrine can affect the expression level of related target genes. Conclusionmatrine has a certain therapeutic effect on IBD and can affect the inflammatory response of IBD. Its therapeutic effect may be related to neuroactive ligand-receptor interaction and other pathways.

The interaction between polyphyllin I and SQLE protein induces hepatotoxicity through SREBP-2/HMGCR/SQLE/LSS pathway / 药物分析学报

Polyphyllin Ⅰ(PPⅠ)and polyphyllin Ⅱ(PⅡ)are the main active substances in the Paris polyphylla.However,liver toxicity of these compounds has impeded their clinical application and the potential hepatotoxicity mechanisms remain to be elucidated.In this work,we found that PPⅠ and PⅡ exposure could induce significant hepatotoxicity in human liver cell line L-02 and zebrafish in a dose-dependent manner.The results of the proteomic analysis in L-02 cells and transcriptome in zebrafish indicated that the hepa-totoxicity of PPⅡ and PⅡwas associated with the cholesterol biosynthetic pathway disorders,which were alleviated by the cholesterol biosynthesis inhibitor lovastatin.Additionally,3-hydroxy-3-methy-lglutaryl CoA reductase(HMGCR)and squalene epoxidase(SQLE),the two rate-limiting enzymes in the choles-terol synthesis,selected as the potential targets,were confirmed by the molecular docking,the over-expression,and knockdown of HMGCR or SQLE with siRNA.Finally,the pull-down and surface plasmon resonance technology revealed that PPⅠ could directly bind with SQLE but not with HMGCR.Collectively,these data demonstrated that PPⅠ-induced hepatotoxicity resulted from the direct binding with SQLE protein and impaired the sterol-regulatory element binding protein 2/HMGCR/SQLE/lanosterol synthase pathways,thus disturbing the cholesterol biosynthesis pathway.The findings of this research can contribute to a better understanding of the key role of SQLE as a potential target in drug-induced hepatotoxicity and provide a therapeutic strategy for the prevention of drug toxic effects with similar structures in the future.

Down-regulation of complement genes in lipopolysaccharide-challenged zebrafish (Danio rerio) larvae exposed to Indonesian propolis / Regulação negativa dos genes do complemento em larvas de peixe-zebra (Danio rerio) desafiadas com lipopolissacarídeo expostas à própolis indonésia

Abstract Although propolis has been reported for having anti-inflammatory activities, its effects on complement system has not been much studied. This research was conducted to find out the effects of Indonesian propolis on the expression levels of C3, C1r/s, Bf, MBL, and C6 in zebrafish larvae which were induced by lipopolysaccharide (LPS). Counting of macrophages migrating to yolk sac and liver histology were carried out. Larvae were divided into four groups: CON (cultured in E3 medium only), LPS (cultured in a medium containing 0.5 μg/L LPS), LPSIBU (cultured in a medium containing LPS, and then treated with 100 μg/L ibuprofen for 24 hours), and LPSPRO (cultured in a medium containing LPS, and then immersed in 14,000 μg/L propolis for 24 hours) groups. The results showed that complement gene expression in larvae from the LPSIBU and LPSPRO groups were generally lower than in larvae from the LPS group. The number of macrophage migrations to the yolk in the LPSPRO group was also lower than in the LPS group. Histological structure of liver in all groups were considered normal. This study shows that Indonesian propolis has the potential to be used as an alternative to the substitution of NSAIDs.

Resumo Embora a própolis tenha sido relatada por ter atividade anti-inflamatória, seus efeitos no sistema complemento, uma parte do sistema imunológico inato, não foram muito estudados. Esta pesquisa foi conduzida para descobrir os efeitos da própolis da Indonésia nos níveis de expressão de C3, C1r/s, Bf, MBL e C6 em larvas de peixe-zebra induzidas por lipopolissacarídeo (LPS). Foram realizadas contagens de macrófagos que migram para o saco vitelino e histologia do fígado. As larvas foram divididas em quatro grupos: CON (cultivadas apenas em meio E3), LPS (cultivadas em meio contendo 0,5 μg/L de LPS), LPSIBU (cultivadas em meio contendo LPS e, em seguida, tratadas com 100 μg/L de ibuprofeno por 24 horas) e LPSPRO (cultivado em meio contendo LPS, e então imerso em própolis 14,000 μg/L por 24 horas). Os resultados mostraram que a expressão do gene do complemento em larvas dos grupos LPSIBU e LPSPRO foi geralmente menor que em larvas do grupo LPS. O número de migrações de macrófagos para a gema no grupo LPSPRO também foi menor que no grupo LPS. A estrutura histológica do fígado em todos os grupos foi considerada normal. Este estudo mostra que a própolis indonésia tem potencial para ser utilizada como alternativa na substituição dos AINEs (anti-inflamatórios não esteroides).

Ethyl Lithospermate Reduces Lipopolysaccharide-Induced Inflammation through Inhibiting NF-κB and STAT3 Pathways in RAW 264.7 Cells and Zebrafish / 中国结合医学杂志

OBJECTIVE@#To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish, and its underlying mechanisms.@*METHODS@#3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide (MTT) assays were performed to investigate the toxicity of ethyl lithospermate at different concentrations (12.5-100 µ mol/L) in RAW 264.7 cells. The cells were stimulated with LPS (100 ng/mL) for 12 h to establish an inflammation model in vitro, the production of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor α (TNF-α) were assessed by enzyme linked immunosorbent assay (ELISA). Western blot was used to ascertain the protein expressions of signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NF-κB) p65, phospho-STAT3 (p-STAT3, Tyr705), inhibitor of NF-κB (IκB) α, and phospho-I κB α (p-IκB α, Ser32), and confocal imaging was used to identify the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705). Additionally, the yolk sacs of zebrafish (3 days post fertilization) were injected with 2 nL LPS (0.5 mg/mL) to induce an inflammation model in vivo. Survival analysis, hematoxylin-eosin (HE) staining, observation of neutrophil migration, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to further study the anti-inflammatory effects of ethyl lithospermate and its probable mechanisms in vivo.@*RESULTS@#The non-toxic concentrations of ethyl lithospermate have been found to range from 12.5 to 100 µ mol/L. Ethyl lithospermate inhibited the release of IL-6 and TNF-α(P<0.05 or P<0.01), decreased IκBα degradation and phosphorylation (P<0.05) as well as the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705) in LPS-induced RAW 264.7 cells (P<0.01). Ethyl lithospermate also decreased inflammatory cells infiltration and neutrophil migration while increasing the survival rate of LPS-stimulated zebrafish (P<0.05 or P<0.01). In addition, ethyl lithospermate also inhibited the mRNA expression levels of of IL-6, TNF-α, IκBα, STAT3, and NF-κB in LPS-stimulated zebrafish (P<0.01).@*CONCLUSION@#Ethyl lithospermate exerts anti-Inflammatory effected by inhibiting the NF-κB and STAT3 signal pathways in RAW 264.7 macrophages and zebrafish.

Radix Panacis quinquefolii Extract Ameliorates Inflammatory Bowel Disease through Inhibiting Inflammation / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-inflammatory activity of Radix Panacis quinguefolii root extract (RPQE) and its therapeutic effects on inflammatory bowel disease (IBD).@*METHODS@#The 72-hour post-fertilization zebrafish was used to generate the local and systematic inflammation models through tail-amputation and lipopolysaccharide (LPS)-induction (100 µ g/mL), respectively. The Tg(zlyz:EGFP) zebrafish was induced with 75 µ g/mL 2,4,6-trinitrobenzene sulfonic acid (TNBS) for establishing the IBD model. The tail-amputated, LPS-, and TNBS-induced models were subjected to RPQE (ethanol fraction, 10-20 µ g/mL) administration for 12 and 24 h, respectively. Anti-inflammatory activity of RPQE was evaluated by detecting migration and aggregation of leukocytes and expression of inflammation-related genes. Meanwhile, TNBS-induced fish were immersed in 0.2% (W/V) calcein for 1.5 h and RPQE for 12 h before photographing to analyze the intestinal efflux efficiency (IEE). Moreover, the expression of inflammation-related genes in these fish was detected by quantitative polymerase chain reaction.@*RESULTS@#Subject to RPQE administration, the migration and aggregation of leukocytes were significantly alleviated in 3 zebrafish models (P<0.01). Herein, RPQE ameliorated TNBS-induced IBD with respect to a significantly reduced number of leukocytes, improved IEE, and inhibited gene expression of pro-inflammatory factors (P<0.05 or P<0.01).@*CONCLUSION@#RPQE exhibited therapeutic effects on IBD by inhibiting inflammation.

Establishment of Patient-Derived Xenograft (PDX) Zebrafish Model of Multiple Myeloma and Its Application in Drug Screening / 中国实验血液学杂志

OBJECTIVE@#To establish a MM patient-derived tumor xenograft model (MM-PDX) in zebrafish, and to evaluate the anti-myeloma activity of indirubin-3'-monoxime(I3MO) using this model.@*METHODS@#Zebrafish embryos 2 days after fertilization were transplanted with fluorescence labeled myeloma primary tumor cells, the survival of primary tumor cells in zebrafish was observed at 0,16 and 24 hours after cell injection. The zebrafish embryos after tumor cell transplantation were randomly divided into control group, BTZ treatment and I3MO treatment group. Before and 24 hours after treatment with BTZ and I3MO, the positive area with calcein or Dil in zebrafish were observed under fluorescence microscope to reflect the survival of tumor cells, and it was verified.@*RESULTS@#MM patient derived tumor cells survived in zebrafish. The construction of MM-PDX was successful. Compared with control group, the fluo- rescence area of the BTZ and I3MO treatment groups in zebrafish were significantly decreased(P<0.05), and BTZ and I3MO significantly inhibited the survival of MM cells in zebrafish.@*CONCLUSION@#MM-PDX model was successfully established. Zebrafish model derived from tumor cells of MM patients can be used as a tool for drug screening of MM.

Role of pcgf5a in the early development of zebrafish / 解剖学报

Objective To investigate the role of pcgf5a gene during zebrafish embryonic development. Methods pcgf5a morpholine antisense morpholino oligomers(MO) was microinjected to delete the expression of pcgf5a gene, and possible phenotypes were examined in pcgf5a-deficient embryos. The whole mount in situ hybridization and Real-time PCR were used to detect alterations of key genes related to the development of nervous system and eye. Results After pcgf5a gene knockdown, the development of ectoderm and mesoderm of zebrafish embryos were affected. The brain size became smaller, and the eyes developed retarded, and the tail was curled and the body axis was shortened(548/891). In addition, the expressions of sox2(82/98), sox3(73/84), foxg1(70/88), pax6a(36/45), pax2a, vsx2 and rx1(n = 5) were significantly reduced. Conclusion pcgf5a affects the morphogenesis of nervous system and eye, possibly due to regulating the expression of the transcription factors related to their development via the processes of cell proliferation and apoptosis.

Research progress in the reprogramming of retinal Müller glia cells / 解剖学报

[Abstract] Blinding eye diseases caused by retinal degeneration have a detrimental effect on human health. Mammalian retina exhibits very limited capacity for self-repair after degenerative disease or injury. In contrast, zebrafish retina possesses a robust regenerative response that regenerates all types of retinal neurons and restores vision. Retina regeneration in zebrafish depends on a type of glia cells called Müller glia. Following retinal injury, zebrafish Müller glia undergo a reprogramming process and proliferate into multipotent progenitor cells that further differentiate into newborn retinal neurons. In recent years, significant progress has been made in the field of Müller glia-based retina regeneration. Here we summarize the mechanisms governing zebrafish retina regeneration and the recent advances in mammalian Müller glia reprogramming.

Therapeutic effect evaluation of leonurine,polygonatum polysaccharide and deoxynojirimycin in combination on antithrombosis and hypoglycaemia / 中国药理学通报

Aim To evaluate the efficacy of the combination of leonurine(SCM),polygonatum polysaccharide(PSP)and deoxynojirimycin(DNJ)in hypoglycemic and antithrombotic aspects by establishing and using zebrafish type II diabetes combined with thrombosis model. Methods On the basis of the zebrafish type II diabetes model established by streptozotocin,phenylhydrazine(PH),arachidonic acid(AA)and ponatinib(PT)were used respectively to establish thrombosis models,which were divided into control group,model group,metformin+aspirin group,and the high,medium and low concentration groups of the combination drugs. After drug intervention in the experimental group,the thrombosis of tail vein was observed. Kit was used to determine the sugar content of juvenile fish tissues in each group. Quantitative analysis of cardiac erythrocytes by o-dianisidine staining method was used to calculate the inhibition rate of thrombus. Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the mRNA expressions of related genes in zebrafish. Results Compared with the model group,the combined drug could significantly increase the staining intensity of erythrocytes in zebrafish hearts,inhibit thrombosis,down-regulate the expression of thrombosis-related genes,and reduce tissue glucose content. Conclusions The combined use of the three drugs can effectively reduce the tissue sugar content and have antithrombotic effect,which show great potential in the development of drugs for the treatment of type II diabetes and thrombosis.

Mechanism of seahorse ameliorating depression-like behavioral and pathological changes caused by chronic stress in zebrafish / 中国药理学通报

Aim To investigate the effect of marine herbal seahorse on chronic unpredictable mild stress ( CUMS ) -induced depression-like model in zebrafish. Methods Adult zebrafish were divided into control, Stress,Stress + low dose (Stress +0.044% SH) and Stress + high dose (Stress +0. 22% SH) seahorse intervention groups, and depression-like behavior was identified by novel tank test (NTT), cortisol, interleukin ( IL )-6 and interferon (IFN )-γ levels were detected by ELISA. The levels of dopamine (DA) ,norepinephrine (NE), 5-hydroxytryptamine (5-HT) and 5-hydroxyin-doleacetic acid (5-HIAA) were determined by high performance liquid chromatography. The mRNA expression levels of tryptophan hydroxylase(TPH)-2 and 5-HT2A receptor were measured by real-time quantitative PCR. Results Compared with the control group, the Stress group showed significantly longer latency to reach the top in NTT, significantly reduced number of transfers to the top region and top residence time, significantly increased levels of cortisol and IL-6, IFN-γ protein, significantly reduced levels of DA and 5-HT in brain as well as increased metabolism rate of 5-HT, while 5-HT2A mRNA expression was up-regulated and TPH2 mRNA expression was down-regulated. In contrast, low-dose seahorse intervention effectively reduced anxiety, decreased cortisol and IL-6 and IFN-γ concentrations, increased monoamine neurotransmitter levels and reversed dysregulation of the 5-HT ergic system in CUMS zebrafish. Conclusion Seahorse may exert an-tidepressant effects through anti-inflammation and mod¬ulation of monoamine neurotransmitter levels.

Effects of lead exposure on development of heart and spine in zebrafish embryos / 环境与职业医学

Background Lead is widely distributed. Lead exposure interferes with early life development in zebrafish, but the mechanisms by which lead exposure affects skeletal development and cardiac development are not clear as yet. Objective To investigate the molecular mechanisms of bone development and cardiac development toxicity induced by lead acetate exposure. Methods Zebrafish embryos were exposed to different concentrations of lead acetate (0, 6, 12, 24, and 48 μmol·L−1) for 3 h post-fertilization (3 hpf) until 5 d post-fertilization (5 dpf). The malformation phenotypes of 5 dpf were counted, and the mRNA expressions of spinal development-related genes (bmp2b, bmp4, bmp9, runx2a, runx2b) and heart development-related genes (nkx2.5, myh6, myh7) were detected by quantitative PCR (qPCR). Expressions of genes of development-related regulatory pathways including Wnt/β-catenin pathway (wnt5a, wnt8a, wnt10a, β-catenin) and TGF-β pathway (tgf-β1, tgf-β2) as well as key molecule eph of Eph-Ephrin signaling were analyzed. Results At 5 dpf, the zebrafish in the lead acetate treated groups showed deformed phenotypes including spinal curvature and pericardial sac edema compared to the control group. In the lead acetate groups at 24 and 48 μmol·L−1, the spinal curvature deformity rates reached 26.47% and 71.52% (P<0.01) respectively. The qPCR results revealed that the expression levels of spinal development-related genes bmp2b, bmp4, bmp9, runx2a, and runx2b were downregulated in the 48 μmol·L−1 exposure group compared to the control group by 82.8%, 58.0%, 88.7%, 85.5%, and 69.2%, respectively (P<0.05 or P<0.01); the expression levels of heart development-related genes myh6, myh7, and nkx2.5 were down-regulated by 63.7%, 58.9%, and 55.2%, respectively (P<0.01); the expression levels of wnt8a and β-catenin in the Wnt/β-catenin pathway were down-regulated by 71.5% and 47.3% (P < 0.05 or P < 0.01), respectively; the expression level of tgf- β1 in the TGF-β pathway was down-regulated by 67.5% (P<0.01); the expression level of eph was down-regulated by 86.9% (P<0.01). Conclusion Lead acetate exerts developmental toxic effects on zebrafish heart and bone by down-regulating the expressions of genes related to spinal development and heart development, as well as inhibiting development-related Wnt/β-catenin and TGF-β pathways and Eph-Ephrin signaling, causing malformed phenotypes such as spinal curvature and pericardial sac edema.

Screening of active components and preliminary mechanism exploration of Lycii Fructus for improving osteoporosis based on the zebrafish model / 药学学报

Juvenile zebrafish were used to screen the active components of Lycii Fructus for improving osteoporosis. The screening results were further verified by zebrafish adult osteoporosis model and the action mechanism was explored. Prednisolone was used as the inducer to build osteoporosis models of juvenile and adult zebrafish, and 9 groups of samples of different extracts and chemical parts of Lycii Fructus were given. Alizarin red staining was applied for observing the scale matrix mineralization and bone resorption. The activities of osteoblasts and osteoclasts were detected using alkaline phosphatase (ALP) and tartrate resistant acid phosphatase (TRAP/TRACP) staining. The expressions of bone metabolism-related genes alp, osteoprotectin (opn), osteoblast specific transcription factor (sp7), cathepsin K (ctsk), tracp, and Runt family transcription factor 2b (runx2b) in each group were determined using quantitative polymerase chain reaction. The results showed that all components of Lycii Fructus improved the formation area of the first vertebrae, the staining light density value, and the number of vertebrae joints in juvenile zebrafish and the Lycium barbarum polysaccharide (LBP) treatment group exerted the best effect. In addition, LBP prevented the formation of bone resorption lacunae in zebrafish scales, increased ALP activity, decreased TRAP activity, up-regulated the alp, sp7, and opn genes, and lowered the expressions of ctsk and tracp genes. In conclusion, LBP regulated the activity of osteoblasts and osteoclasts, reduced bone resorption, promoted bone formation and enhanced bone density, which might be the main anti-osteoporosis active fraction of Lycii Fructus. This study provided modern scientific evidence for the scientific connotation of the traditional effect of "strengthening bones and muscles" of Lycii Fructus, provided the reference for the evaluation of the anti-osteoporosis activity of traditional Chinese medicine based on zebrafish adult model, and provided beneficial enlightenment for the bone health needs of the aging society population.

Immune regulation mechanism of Saposhnikoviae Radix polysaccharide based on zebrafish model / 中国中药杂志

The immunomodulatory effect of Saposhnikoviae Radix polysaccharide(SRP) was evaluated based on the zebrafish mo-del, and its mechanism was explored by transcriptome sequencing and real-time fluorescence-based quantitative PCR(RT-qPCR). The immune-compromised model was induced by navelbine in the immunofluorescence-labeled transgenic zebrafish Tg(lyz: DsRed), and the effect of SRP on the density and distribution of macrophages in zebrafish was evaluated. The effect of SRP on the numbers of macrophages and neutrophils in wild-type AB zebrafish was detected by neutral red and Sudan black B staining. The content of NO in zebrafish was detected by DAF-FM DA fluorescence probe. The content of IL-1β and IL-6 in zebrafish was detected by ELISA. The differentially expressed genes(DEGs) of zebrafish in the blank control group, the model group, and the SRP treatment group were analyzed by transcriptome sequencing. The immune regulation mechanism was analyzed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment, and the expression levels of key genes were verified by RT-qPCR. The results showed that SRP could significantly increase the density of immune cells in zebrafish, increase the number of macrophages and neutrophils, and reduce the content of NO, IL-1β, and IL-6 in immune-compromised zebrafish. The results of transcriptome sequencing analysis showed that SRP could affect the expression level of immune-related genes on Toll-like receptor pathway and herpes simplex infection pathway to affect the release of downstream cytokines and interferon, thereby completing the activation process of T cells and playing a role in regulating the immune activity of the body.

Construction of fluorescent transgenic zebrafish Tg (ttn.2: EGFP) / 生物工程学报

In order to develop a transgenic zebrafish line with green fluorescent protein (enhanced green fluorescent protein, EGFP) expressed specifically in muscle and heart, the recombinant expression vector constructed using the zebrafish ttn.2 gene promoter fragment and EGFP gene coding sequence and the capped mRNA of Tol2 transposase were co-injected into the zebrafish 1-cell stage embryos. The stable genetic Tg (ttn.2: EGFP) transgenic zebrafish line was successfully developed by fluorescence detection, followed by genetic hybridization screening and molecular identification. Fluorescence signals and whole-mount in situ hybridization showed that EGFP expression was located in muscle and heart, the specificity of which was consistent with the expression of ttn.2 mRNA. Inverse PCR showed that EGFP was integrated into chromosomes 4 and 11 of zebrafish in No. 33 transgenic line, while integrated into chromosome 1 in No. 34 transgenic line. The successful construction of this fluorescent transgenic zebrafish line, Tg (ttn.2: EGFP), laid a foundation for the research of muscle and heart development and related diseases. In addition, the transgenic zebrafish lines with strong green fluorescence can also be used as a new ornamental fish.

Exploring the key anti-fatigue components of American ginseng based on metabolomics and zebrafish models / 药学学报

The aim of this paper is to explore the key anti-fatigue active components in the saponin-like composition of American ginseng. The anti-fatigue activity of western ginseng samples was evaluated using a zebrafish model; metabolomics techniques were used to identify the main saponins in western ginseng from different origins; the active substances and relevant targets of the anti-fatigue effect of western ginseng were initially screened by constructing a PPI protein interaction network between western ginseng saponins and disease targets, and the key active ingredients were screened using a molecular docking method; finally, the anti-fatigue activity of the key active ingredients was evaluated using a zebrafish, animal experiment was approved by the Ethics Committee of Shandong Academy of Medical Sciences (SYXK20220005). The anti-fatigue activity of the key active ingredients was evaluated using a zebrafish model. The results of the zebrafish activity evaluation showed that there were significant differences in the activities of the western ginseng samples from the two origins, and a total of 10 different saponins were identified as possibly related to the anti-fatigue activity after further metabolomic testing and pattern discrimination. The core anti-fatigue targets were screened with the help of component-disease target PPI, combined with pharmacophore-like parameters and molecular docking techniques, and pseudoginsenoside F11 was found to have good binding activity to five of the targets. Finally, the zebrafish model revealed that pseudoginsenoside F11 exhibited significant anti-fatigue activity. This study used metabolomics and zebrafish model to screen the key active substances of pseudoginsenoside F11 for its anti-fatigue activity, which will provide a reference for further research on the anti-fatigue of pseudoginsenosides.

Anti-osteoporosis mechanism of Panax quiquefolium L. based on zebrafish model and metabonomics / 药学学报

In this study, we investigated the anti-osteoporotic activity and mechanism of action of extract of Panax quiquefolium L. based on zebrafish model combined with metabolomics technology. A zebrafish model of prednisolone-induced osteoporosis was used to compare the anti-osteoporotic activity of Panax quiquefolium L., and the expression of osteoblast-associated genes and osteoclast-associated genes in zebrafish was detected by quantitative real-time PCR (qRT-PCR), using bone fluorescence area and fluorescence density as evaluation indexes. Metabolomics based on ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to explore the change patterns of biomarkers and the metabolic pathways affected. The results showed that the 50% ethanol extracts of Panax quiquefolium L. from Jilin, Canada, Wenden and the United States can significantly improve the bone fluorescence area of zebrafish compared with model group. Furthermore, four sources 50% ethanol extracts of Panax quiquefolium L. except United States also can significantly improve the bone fluorescence density of zebrafish. In addition, PCR showed that extract of Panax quiquefolium L. can significantly up-regulated the expression of vitamin D receptor b (vdrb), collagen type I α2 (col1a2) and cysteine-rich acidic secreted protein (sparc) genes, and down-regulated the expression of matrix metalloproteinase 9 (mmp9), anti-tartrase acid phosphatase (trap) and cathepsin K (ctsk) genes. Metabolomic analysis identified 24 key differential metabolites. Furthermore, pathway analysis showed that Panax quiquefolium L. could regulate the levels of 10 key biomarkers by participating in purine metabolism, tricarboxylic acid cycle and pentose phosphate metabolism and improve the osteoporosis status of zebrafish. This study preliminically revealed the anti-osteoporosis mechanism of 50% ethanol extract from Panax quiquefolium L. through multi-component, multi-target and multi-pathway and also provides theoretical basis for clinical development and utilization of anti-osteoporosis products of Panax quiquefolium L. This experiment was approved by the Experimental Animal Welfare Ethics Committee of the Institute of Biology, Shandong Academy of Sciences (approval number: SWS20181002).

Hepatotoxicity and mechanism of Rhododendri Mollis Flos based on zebrafish model / 中国中药杂志

This study used the zebrafish model to explore the hepatotoxicity of Rhododendri Mollis Flos(RMF). The mortality was calculated according to the number of the survival of zebrafish larvae 4 days after fertilization under different concentration of RMF, and the dose-toxicity curve was fitted to preliminarily evaluate the toxicity of RMF. The liver phenotypes under the sublethal concentration of RMF in the treatment group and the blank control group were observed by hematoxylin-eosin(HE) staining and acridine orange(AO) staining. Meanwhile, the activities of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were determined to confirm the hepatotoxicity of RMF. Real-time quantitative polymerase chain reaction(real-time PCR) and Western blot were used to determine the expressions of genes and proteins in zebrafish larvae. Gas chromatography time-of-flight mass spectrometry(GC-TOF-MS) was used to conduct untargeted metabolomics testing to explore the mechanism. The results showed that the toxicity of RMF to zebrafish larvae was dose-dependent, with 1 100 μg·mL~(-1) of the absolute lethal concentration and 448 μg·mL~(-1) of sublethal concentration. The hepatocyte apoptosis and degeneration appeared in the zebrafish larvae under the sublethal concentration of RMF. The content of ALT and AST in zebrafish larvae at the end of the experiment was significantly increased in a dose-dependent manner. Under the sublethal concentration, the expressions of genes and proteins related to apoptosis in zebrafish larvae were significantly increased as compared with the blank control group. The results of untargeted metabolomics showed that the important metabolites related to the he-patotoxicity of RMF were mainly enriched in alanine, aspartic acid, glutamic acid, and other pathways. In conclusion, it is inferred that RMF has certain hepatotoxicity to zebrafish larvae, and its mechanism may be related to apoptosis.

Single-cell analysis reveals an Angpt4-initiated EPDC-EC-CM cellular coordination cascade during heart regeneration

Mammals exhibit limited heart regeneration ability, which can lead to heart failure after myocardial infarction. In contrast, zebrafish exhibit remarkable cardiac regeneration capacity. Several cell types and signaling pathways have been reported to participate in this process. However, a comprehensive analysis of how different cells and signals interact and coordinate to regulate cardiac regeneration is unavailable. We collected major cardiac cell types from zebrafish and performed high-precision single-cell transcriptome analyses during both development and post-injury regeneration. We revealed the cellular heterogeneity as well as the molecular progress of cardiomyocytes during these processes, and identified a subtype of atrial cardiomyocyte exhibiting a stem-like state which may transdifferentiate into ventricular cardiomyocytes during regeneration. Furthermore, we identified a regeneration-induced cell (RIC) population in the epicardium-derived cells (EPDC), and demonstrated Angiopoietin 4 (Angpt4) as a specific regulator of heart regeneration. angpt4 expression is specifically and transiently activated in RIC, which initiates a signaling cascade from EPDC to endocardium through the Tie2-MAPK pathway, and further induces activation of cathepsin K in cardiomyocytes through RA signaling. Loss of angpt4 leads to defects in scar tissue resolution and cardiomyocyte proliferation, while overexpression of angpt4 accelerates regeneration. Furthermore, we found that ANGPT4 could enhance proliferation of neonatal rat cardiomyocytes, and promote cardiac repair in mice after myocardial infarction, indicating that the function of Angpt4 is conserved in mammals. Our study provides a mechanistic understanding of heart regeneration at single-cell precision, identifies Angpt4 as a key regulator of cardiomyocyte proliferation and regeneration, and offers a novel therapeutic target for improved recovery after human heart injuries.