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1.
Ecotoxicol Environ Saf ; 192: 110268, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32036099

RESUMO

Present study highlighted the ultramicroscopic (SEM) alterations of the skin, eye, barbel, and fins of spawn of an air-breathing teleost (Clarias batrachus, Linn. 1758) induced by UV-B radiation (280-320 nm) at a dose (@4.07 × 10-20J/photon/m2) under the time-frame of 5, 10 and 15 min/d in the laboratory condition for the periods of 5 and 10 days. Limnological parameters revealed no significant changes throughout the period of experimentation which were measured by PCS Testr 35 Multi-Parameter. Morphometric analysis revealed that during the extended exposure period of 10 days the spawn size and weight were reduced as analysed through Specific Growth Rate (SGR). SGR values in terms of weight for 5 and 10 days under 3 time-frames were 17.12%, 12.52%, 11.46% and 9.09%, 6.43%, 6.09% respectively, which revealed a declined trend along with the exposure days. In the skin of C. batrachus, the compact regular orientation of the stratified epithelial cells and mucous cells became distorted and the microridges and double-ridged structures showed destruction and fragmentations. The body striations and microfolds became shrinked and swollen and finally degenerated to form a mass. The distribution of mucous cells throughout the epidermis was disorganised and releasing secretory contents on the surface through small pores. Appearance of huge quantity of biogenic semi-hexagonal plate like crystals (guanine platelets) on the skin surface of the body was the most significant observations during UV-B radiation. In the developmental phases the eyeball showed shrinkage loosing normal regular concave structure and to become a dome-shaped one. The supportive connective infoldings became loosened. The choroid coat displayed deformities and the iris deformed the pupil. The fibroblast on the epithelium and melanocytes depicted dispersed arrangement. The pairs of ventral barbels near the mouth depicted the presence of taste buds that became severely damaged exposing the sensory as well as neuroepithelial cells. Compact regular arrangement of the SECs was completely destroyed leaving long and deep channels inbetween them; the disintegrated concentric MRs also showed a mass.


Assuntos
Nadadeiras de Animais/efeitos da radiação , Peixes-Gato , Olho/efeitos da radiação , Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Nadadeiras de Animais/ultraestrutura , Animais , Relação Dose-Resposta à Radiação , Epiderme/efeitos da radiação , Epiderme/ultraestrutura , Epitélio/efeitos da radiação , Epitélio/ultraestrutura , Olho/ultraestrutura , Pele/ultraestrutura
2.
Artigo em Inglês | MEDLINE | ID: mdl-29567411

RESUMO

Lamin is an intermediate protein underlying the nuclear envelope and it plays a key role in maintaining the integrity of the nucleus. A defect in the processing of its precursor by a metalloprotease, ZMPSTE24, results in the accumulation of farnesylated prelamin in the nucleus and causes various diseases, including Hutchinson-Gilford progeria syndrome (HGPS). However, the role of lamin processing is unclear in fish species. Here, we generated zmpste24-deficient medaka and evaluated their phenotype. Unlike humans and mice, homozygous mutants did not show growth defects or lifespan shortening, despite lamin precursor accumulation. Gonadosomatic indices, blood glucose levels, and regenerative capacity of fins were similar in 1-year-old mutants and their wild-type (WT) siblings. Histological examination showed that the muscles, subcutaneous fat tissues, and gonads were normal in the mutants at the age of 1 year. However, the mutants showed hypersensitivity to X-ray irradiation, although p53target genes, p21 and mdm2, were induced 6 h after irradiation. Immunostaining of primary cultured cells from caudal fins and visualization of nuclei using H2B-GFP fusion proteins revealed an abnormal nuclear shape in the mutants both in vitro and in vivo. The telomere lengths were significantly shorter in the mutants compared to WT. Taken together, these results suggest that zmpste24-deficient medaka phenocopied HGPS only partially and that abnormal nuclear morphology and lifespan shortening are two independent events in vertebrates.


Assuntos
Núcleo Celular/patologia , Modelos Animais de Doenças , Proteínas de Peixes/deficiência , Proteínas de Membrana/deficiência , Metaloendopeptidases/deficiência , Oryzias/genética , Progéria/patologia , Nadadeiras de Animais/enzimologia , Nadadeiras de Animais/patologia , Nadadeiras de Animais/efeitos da radiação , Animais , Animais Geneticamente Modificados , Núcleo Celular/enzimologia , Núcleo Celular/efeitos da radiação , Forma do Núcleo Celular/efeitos da radiação , Células Cultivadas , Códon sem Sentido , Feminino , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Técnicas de Inativação de Genes , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Heterozigoto , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Metaloendopeptidases/genética , Metaloendopeptidases/metabolismo , Oryzias/metabolismo , Progéria/enzimologia , Progéria/genética , Tolerância a Radiação , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Análise de Sobrevida , Encurtamento do Telômero/efeitos da radiação
3.
Sci Rep ; 6: 33601, 2016 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-27640676

RESUMO

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 µm wide) and minibeams (200-800 µm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool.


Assuntos
Plaquetas/efeitos da radiação , Vasos Sanguíneos/patologia , Infiltração de Neutrófilos/efeitos da radiação , Adesividade Plaquetária/efeitos da radiação , Síncrotrons , Nadadeiras de Animais/irrigação sanguínea , Nadadeiras de Animais/efeitos da radiação , Nadadeiras de Animais/ultraestrutura , Animais , Tecido Conjuntivo/patologia , Hemostasia , Inflamação/patologia , Perfusão , Peixe-Zebra
4.
Aquat Toxicol ; 142-143: 303-16, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24080042

RESUMO

The 2010 Deepwater Horizon disaster in the Gulf of Mexico was the largest oil spill in United States history. Crude oils are highly toxic to developing fish embryos, and many pelagic fish species were spawning in the northern Gulf in the months before containment of the damaged Mississippi Canyon 252 (MC252) wellhead (April-July). The largest prior U.S. spill was the 1989 grounding of the Exxon Valdez that released 11 million gallons of Alaska North Slope crude oil (ANSCO) into Prince William Sound. Numerous studies in the aftermath of the Exxon Valdez spill defined a conventional crude oil injury phenotype in fish early life stages, mediated primarily by toxicity to the developing heart. To determine whether this type of injury extends to fishes exposed to crude oil from the Deepwater Horizon - MC252 incident, we used zebrafish to compare the embryotoxicity of ANSCO alongside unweathered and weathered MC252 oil. We also developed a standardized protocol for generating dispersed oil water-accommodated fractions containing microdroplets of crude oil in the size range of those detected in subsurface plumes in the Gulf. We show here that MC252 oil and ANSCO cause similar cardiotoxicity and photo-induced toxicity in zebrafish embryos. Morphological defects and patterns of cytochrome P450 induction were largely indistinguishable and generally correlated with polycyclic aromatic compound (PAC) composition of each oil type. Analyses of embryos exposed during different developmental windows provided additional insight into mechanisms of crude oil cardiotoxicity. These findings indicate that the impacts of MC252 crude oil on fish embryos and larvae are consistent with the canonical ANSCO cardiac injury phenotype. For those marine fish species that spawned in the northern Gulf of Mexico during and after the Deepwater Horizon incident, the established literature can therefore inform the assessment of natural resource injury in the form of potential year-class losses.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Nadadeiras de Animais/efeitos dos fármacos , Nadadeiras de Animais/efeitos da radiação , Animais , Dermatite Fototóxica , Embrião não Mamífero/efeitos da radiação , Coração/efeitos dos fármacos , Poluição por Petróleo , Luz Solar , Estados Unidos
5.
Dev Biol ; 365(2): 424-33, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22445510

RESUMO

The zebrafish fin is an excellent system to study the mechanisms of dermal bone patterning. Fin rays are segmented structures that form successive bifurcations both during ontogenesis and regeneration. Previous studies showed that sonic hedgehog (shha) may regulate regenerative bone patterning based on its expression pattern and functional analysis. The present study investigates the role of the shha-expressing cells in the patterning of fin ray branches. The shha expression domain in the basal epidermis of each fin ray splits into two prior to ray bifurcation. In addition, the osteoblast proliferation profile follows the dynamic expression pattern of shha. A zebrafish transgenic line, 2.4shh:gfpABC#15, in which GFP expression recapitulates the endogenous expression of shha, was used to specifically ablate shha-expressing cells with a laser beam. Such ablations lead to a delay in the sequence of events leading to ray bifurcation without affecting the overall growth of the fin ray. These results suggest that shha-expressing cells direct localized osteoblast proliferation and thus regulate branching morphogenesis. This study reveals the fin ray as a new accessible system to investigate epithelial-mesenchymal interactions leading to organ branching.


Assuntos
Nadadeiras de Animais/embriologia , Padronização Corporal/fisiologia , Proteínas Hedgehog/fisiologia , Regeneração , Proteínas de Peixe-Zebra/fisiologia , Peixe-Zebra/embriologia , Nadadeiras de Animais/citologia , Nadadeiras de Animais/efeitos da radiação , Animais , Animais Geneticamente Modificados , Padronização Corporal/efeitos da radiação , Células Cultivadas , Proteínas Hedgehog/antagonistas & inibidores , Lasers , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/antagonistas & inibidores
6.
Drug Chem Toxicol ; 35(3): 341-6, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22289409

RESUMO

We used ultraviolet (UV)-induced fin damage in zebrafish as a system for evaluating the chemopreventive potential of flavonoids. Chemopreventive effects of each compound, including flavone, flavanone, and chalcone, on fin development were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. Results showed that 1) flavone has the highest capacity to protect zebrafish fins from UV-induced damages among other groups; 2) zebrafish fins in the UV+1 ppm flavone group are 1.02~9.60 times more likely to return to normal fins than ones in the UV-only group, but fins in the UV+20 ppm flavone group are only 0.45~5.66 times more likely to recover; and 3) flavone significantly reduced ROS production in UV-exposed zebrafish embryos, which may attenuate UV-mediated apoptosis. In conclusion, zebrafish can be used as a system for comparing the UV-protection efficacy of flavonoids.


Assuntos
Nadadeiras de Animais/efeitos dos fármacos , Nadadeiras de Animais/efeitos da radiação , Flavonas/farmacologia , Lesões Experimentais por Radiação/prevenção & controle , Raios Ultravioleta , Peixe-Zebra/embriologia , Animais , Apoptose/efeitos da radiação , Chalcona/química , Chalcona/farmacologia , Flavanonas/química , Flavanonas/farmacologia , Flavonas/química , Marcação In Situ das Extremidades Cortadas , Estimativa de Kaplan-Meier , Estrutura Molecular , Modelos de Riscos Proporcionais , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
7.
Toxicol Mech Methods ; 21(1): 63-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21067310

RESUMO

This study applied broccoli and cauliflower extracts (whole, floret, and stem) to zebrafish larvae in parallel to receive 100 mJ/cm(2) of UVB six times, and recorded their fin malformation phenotypes. Chemopreventive effects of each group, including UVB, whole-, floret-, and stem-extracts of broccoli and cauliflower on fin development were evaluated using Kaplan-Meier analysis, log-rank test, and Cox proportional hazards regression. Results showed that (1) zebrafish fins in the UVB + whole broccoli extract group are 6.20~9.32-times more likely to return to normal fins than ones in the UVB only group, but fins in the UVB + whole cauliflower extract group are only 5.13~11.10-times more likely to recover, indicated that whole broccoli and cauliflower extract had similar chemopreventive ability on fin development; and (2) the broccoli stem has the highest antioxidant capacity among other groups. In conclusion, zebrafish can be used as a system for evaluating the efficacy of other UVB protective compounds.


Assuntos
Nadadeiras de Animais/efeitos da radiação , Brassica/química , Extratos Vegetais/farmacologia , Raios Ultravioleta , Animais , Larva/efeitos dos fármacos , Extratos Vegetais/química , Peixe-Zebra/embriologia
8.
Development ; 137(23): 3931-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20980402

RESUMO

In vertebrates, the adult form emerges from the embryo by mobilization of precursors or adult stem cells. What different cell types these precursors give rise to, how many precursors establish the tissue or organ, and how they divide to establish and maintain the adult form remain largely unknown. We use the pigment pattern of the adult zebrafish fin, with a variety of clonal and lineage analyses, to address these issues. Early embryonic labeling with lineage-marker-bearing transposons shows that all classes of fin melanocytes (ontogenetic, regeneration and kit-independent melanocytes) and xanthophores arise from the same melanocyte-producing founding stem cells (mFSCs), whereas iridophores arise from distinct precursors. Additionally, these experiments show that, on average, six and nine mFSCs colonize the caudal and anal fin primordia, and daughters of different mFSCs always intercalate to form the adult pattern. Labeled clones are arrayed along the proximal-distal axis of the fin, and melanocyte time-of-differentiation lineage assays show that although most of the pigment pattern growth is at the distal edge of the fin, significant growth also occurs proximally. This suggests that leading edge melanocyte stem cells (MSCs) divide both asymmetrically to generate new melanocytes, and symmetrically to expand the MSCs and leave quiescent MSCs in their wake. Clonal labeling in adult stages confirms this and reveals different contributions of MSCs and transient melanoblasts during growth. These analyses build a comprehensive picture for how MSCs are established and grow to form the pigment stripes of the adult zebrafish fins.


Assuntos
Nadadeiras de Animais/citologia , Nadadeiras de Animais/crescimento & desenvolvimento , Melanócitos/citologia , Organogênese , Regeneração/fisiologia , Células-Tronco/citologia , Peixe-Zebra/crescimento & desenvolvimento , Envelhecimento/fisiologia , Nadadeiras de Animais/efeitos da radiação , Animais , Padronização Corporal/efeitos da radiação , Células Clonais , Elementos de DNA Transponíveis/genética , Melanócitos/efeitos da radiação , Organogênese/efeitos da radiação , Proteínas Proto-Oncogênicas c-kit/metabolismo , Regeneração/efeitos da radiação , Células-Tronco/efeitos da radiação , Raios X
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