scholarly journals Comparative Analysis of Neurotoxicity of Six Phthalates in Zebrafish Embryos

Toxics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 5
Author(s):  
Cong Minh Tran ◽  
Trinh Ngoc Do ◽  
Ki-Tae Kim

The effects and underlying mechanisms of phthalates on neurotoxicity remain unclear as compared with the potentials of these substances as endocrine disruptors. The locomotor activities of zebrafish embryos were investigated upon exposure to six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBzP), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DnOP), and diisononyl phthalate (DiNP). Moreover, changes in fluorescence intensity in the green fluorescent protein (GFP) transgenic (Tg) lines Tg(HuC:eGFP), Tg(sox10:eGFP), and Tg(mbp:GFP) were measured after exposure to six phthalates, and changes in the expression profiles of genes involved in the cholinergic (ache) and dopaminergic systems (dat, th, and drd1b) were assessed. Exposure to BBzP, DEHP, and DiNP affected larval behaviors, whereas exposure to DMP, DEP, and DnOP revealed no alterations. A reduced expression of Tg(HuC:eGFP) was observed upon exposure to BBzP, DEHP, and DiNP. The expression of Tg(sox10:eGFP) and Tg(mbp:GFP) was reduced only in response to BBzP and DiNP, respectively. Further, exposure to DiNP upregulated ache and drd1b. The upregulation of ache and downregulation of drd1b was observed in DEHP-exposed groups. Exposure to BBzP suppressed th expression. These observations indicate that exposure to phthalates impaired embryogenesis of the neurological system and neurochemicals in zebrafish embryos, although the detailed mechanisms varied among the individual phthalates. Further mechanistic studies are needed to better understand the causality between phthalate exposure and neurotoxicity.

2020 ◽  
Author(s):  
Noriyuki Satoh ◽  
Koji Kinjo ◽  
Kohei Shintaku ◽  
Daisuke Kezuka ◽  
Hiroo Ishimori ◽  
...  

ABSTRACTCorals of the family Acroporidae are key structural components of reefs that support the most diverse marine ecosystems. Due to increasing anthropogenic stresses, coral reefs are in decline. Along the coast of Okinawa, Japan, three different color morphs of Acropora tenuis have been recognized for decades. These include brown (N morph), yellow-green (G) and purple (P) forms. The tips of axial coral polyps exhibit specific fluorescence spectra. This attribute is inherited asexually, and color morphs do not change seasonally. In Okinawa Prefecture, during the summer of 2017, the N and P morphs experienced bleaching, in which some N morphs died while P morphs recovered. In contrast, G morphs successfully withstood the stress. Symbiotic dinoflagellates are essential symbiotic partners of scleractinian corals. Photosynthetic activity of symbionts was reduced in July in N and P morphs; however, the three color-morphs host similar sets of Clade-C zoothanthellae, suggesting that beaching of N and P morphs cannot be attributed to differences in symbiont clades. The decoded Acropora tenuis genome includes five genes for green fluorescent proteins (GFP), two for cyan fluorescent proteins (CFP), three for red fluorescent proteins (RFP), and seven genes for chromoprotein (ChrP). A summer survey of gene expression profiles demonstrated that (a) expression of CFP and REP was quite low in all three morphs, (b) P morphs expressed higher levels of ChrP, (c) both N and G morphs expressed GFP highly, and (d) GFP expression was reduced in N morphs, compared to G morphs, which maintained higher levels of GFP expression throughout the summer. Although further studies are required to understand the biological significance of these color morphs of Acropora tenuis, our results suggest that thermal stress resistance is modified by genetic mechanisms that coincidentally lead to diversification of color morphs.


2011 ◽  
Vol 301 (5) ◽  
pp. C1239-C1250 ◽  
Author(s):  
Joseph A. Roche ◽  
Diana L. Ford-Speelman ◽  
Lisa W. Ru ◽  
Allison L. Densmore ◽  
Renuka Roche ◽  
...  

Electroporation (EP) is used to transfect skeletal muscle fibers in vivo, but its effects on the structure and function of skeletal muscle tissue have not yet been documented in detail. We studied the changes in contractile function and histology after EP and the influence of the individual steps involved to determine the mechanism of recovery, the extent of myofiber damage, and the efficiency of expression of a green fluorescent protein (GFP) transgene in the tibialis anterior (TA) muscle of adult male C57Bl/6J mice. Immediately after EP, contractile torque decreased by ∼80% from pre-EP levels. Within 3 h, torque recovered to ∼50% but stayed low until day 3. Functional recovery progressed slowly and was complete at day 28. In muscles that were depleted of satellite cells by X-irradiation, torque remained low after day 3, suggesting that myogenesis is necessary for complete recovery. In unirradiated muscle, myogenic activity after EP was confirmed by an increase in fibers with central nuclei or developmental myosin. Damage after EP was confirmed by the presence of necrotic myofibers infiltrated by CD68+ macrophages, which persisted in electroporated muscle for 42 days. Expression of GFP was detected at day 3 after EP and peaked on day 7, with ∼25% of fibers transfected. The number of fibers expressing green fluorescent protein (GFP), the distribution of GFP+ fibers, and the intensity of fluorescence in GFP+ fibers were highly variable. After intramuscular injection alone, or application of the electroporating current without injection, torque decreased by ∼20% and ∼70%, respectively, but secondary damage at D3 and later was minimal. We conclude that EP of murine TA muscles produces variable and modest levels of transgene expression, causes myofiber damage due to the interaction of intramuscular injection with the permeabilizing current, and that full recovery requires myogenesis.


Gene ◽  
1996 ◽  
Vol 173 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Adam Amsterdam ◽  
Shuo Lin ◽  
Larry G. Moss ◽  
Nancy Hopkins

2016 ◽  
Vol 17 (2) ◽  
pp. 588-596
Author(s):  
Derek R. Faust ◽  
Kimberly J. Wooten ◽  
Philip N. Smith

Several different materials have been used for production of domestic water pipes throughout history. In recent years, the use of cross-linked polyethylene (PEX) pipe has increased dramatically, yet the potential for leaching of phthalates, which are endocrine disrupting compounds associated with adverse reproductive effects in humans, has not been examined. In this study, the potential of chlorinated polyvinyl chloride (cPVC) and red, blue, and heat PEX piping to leach phthalates into static hot and cold water after 2, 8, and 48 hours was evaluated. Concentrations of six phthalates, dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl-butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di(n-octyl) phthalate (DNOP), were determined by gas chromatography-mass spectrometry. Pipe type (F3,71 = 15.6, P = 0.001) contributed significantly to phthalate concentrations in water, while temperature (F4,71 = 1.74, P = 0.106) and time (F4,71 = 1.02, P = 0.427) were not significant factors. Significantly higher concentrations of DEP, DBP, and BBP were observed in cPVC pipe (<method detection limits (MDL) to 466 ng L−1, 252–4,219 ng L−1, 473–18,400 ng L−1, respectively) compared to blue PEX (T2 = 12.2, P < 0.001; <MDL, <MDL − 140 ng L−1, <MDL − 459 ng L−1, respectively), red PEX (T2 = 19.3, P < 0.001; <MDL, <MDL − 188 ng L−1, <MDL − 881 ng L−1, respectively), and heat PEX (T2 = 19.9, P < 0.001; <MDL, <MDL − 162 ng L−1, <MDL − 169 ng L−1, respectively). Phthalate exposure from drinking water via cPVC or PEX is low when compared to other dietary sources. Nonetheless, a shift from cPVC to PEX pipes in households would decrease potential exposure to phthalates.


2005 ◽  
Vol 71 (12) ◽  
pp. 8531-8536 ◽  
Author(s):  
Richard A. Long ◽  
David C. Rowley ◽  
Eric Zamora ◽  
Jiayuan Liu ◽  
Douglas H. Bartlett ◽  
...  

ABSTRACT Changes in global climate have raised concerns about the emergence and resurgence of infectious diseases. Vibrio cholerae is a reemerging pathogen that proliferates and is transported on marine particles. Patterns of cholera outbreaks correlate with sea surface temperature increases, but the underlying mechanisms for rapid proliferation of V. cholerae during ocean warming events have yet to be fully elucidated. In this study, we tested the hypothesis that autochthonous marine bacteria impede the spread of V. cholerae in the marine environment. It was found that some marine bacteria are capable of inhibiting the growth of V. cholerae on surfaces and that bacterial isolates derived from pelagic particles show a greater frequency of V. cholerae inhibition than free-living bacteria. Vibrio cholerae was less susceptible to antagonism at higher temperatures, such as those measured during El Niño-Southern Oscilliation and monsoonal events. Using a model system employing green fluorescent protein-labeled bacteria, we found that marine bacteria can directly inhibit V. cholerae colonization of particles. The mechanism of inhibition in our model system was linked to the biosynthesis of andrimid, an antibacterial agent. Antibiotic production by the model antagonistic strain decreased at higher temperatures, thereby explaining the increased competitiveness of V. cholerae under warmer conditions. These findings suggest that bacterium-bacterium antagonism is a contributing mechanism in regulating the proliferation of V. cholerae on marine particles.


2006 ◽  
Vol 72 (5) ◽  
pp. 3696-3701 ◽  
Author(s):  
Kyle Jensen ◽  
Hal Alper ◽  
Curt Fischer ◽  
Gregory Stephanopoulos

ABSTRACT Here we present a simple statistical method to determine the phenotypic contribution of a single mutation from libraries of mutants with diverse phenotypes in which each mutant contains a multitude of mutations. The central premise of this method is that, given M phenotypic classes, mutations that do not affect the phenotype should partition among the M classes according to a multinomial distribution. Deviations from this distribution are indicative of a link between specific mutations and phenotypes. We suggest that this method will aid the engineering of functional nucleic acids, proteins, and other biomolecules by uncovering target sites for rational mutagenesis. As a proof of the principle, we show how the method can be used to deduce the individual effects of mutations in a set of 69 PL-λ promoter variants. Each of these promoters was generated by error-prone PCR and incorporated numerous mutations. The activity of the promoters was assayed using flow cytometry to measure the fluorescence of a green fluorescent protein reporter gene. Our analysis of the sequences of these mutants revealed seven positions having a statistically significant correlation with promoter activity. Using site-directed mutagenesis, we constructed point mutations for several sites, both statistically significant and insignificant, and combinations of these sites. Our results show that the statistical method correctly elucidated the phenotypic manifestations of these mutations. We suggest that this method may be useful for expediting directed evolution experiments by allowing both desired and undesired mutations to be identified and incorporated between rounds of mutagenesis.


2015 ◽  
Vol 80 (8) ◽  
pp. 983-996 ◽  
Author(s):  
Danica Milojkovic ◽  
Darko Andjelkovic ◽  
Gordana Kocic ◽  
Tatjana Andjelkovic

Liquid-liquid extraction techniques were compared coupled with gas chromatography-mass spectrometry (GC-MS), for the extraction and the determination of four phthalates: dimethyl phthalate (DMP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP) and di-(2-ethylhexyl) phthalate (DEHP) in six different kinds of milk-based samples. Extraction factors: sample preparation, organic solvent type and volume, salt effect, agitation and the extraction time were optimized. The ion of base peaks (m/z 149 for DBP, BBP and DEHP and m/z 163 for DMP) for investigated phthalates were selected for the screening studies. The acquisition was performed at the selected ion monitoring mode. The MSD response for GC-MS phthalate calibration standards was linear between 0.25 and 2.50 ?g mL-1 with calculated LODs between 0.01 ?g mL-1 to 0.04 ?g mL-1 and LOQs of 0.05 ?g mL-1 to 0.12 ?g mL-1, while repeatability was between 1.7 % to 4.9 % RSD. The study demonstrated an increase of the recovery of less polar phthalates in matrix milk standards by matrix dilution. Recovery for hydrophilic phthalates, like DMP, was not changed by matrix dilution and it was continuously low for the investigated method. Two spiking levels were tested for influence of matrix dilution on phthalate recovery, showed the same trend.


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