Apoptosis In Embryos Research Articles

Pyriproxyfen exposure induces DNA damage, cell proliferation impairments and apoptosis in the brain vesicles layers of chicken embryos

Larvicide pyriproxyfen (PPF), used in drinking water reservoirs to control Aedes mosquitoes, has already been shown as a possible cause of congenital anomalies in the central nervous system. However, the neurotoxic effects of PPF on the development of vertebrate embryos are still underexplored. Thus, the aim of this study was to investigate the effects of PPF on the morphometric parameters of the head and brain, as well as on the cell layers of the forebrain and midbrain, using embryos of Gallus domesticus as a model. Two sublethal PPF concentrations (0.01 mg/L and 10 mg/L), as defined by a survival curve, were tested. Analysis of the biometry of embryos showed significant reduction in body and brain mass and also in measurements of the head and brain. A reduction in cell layer thickness of the forebrain and midbrain was observed, accompanied by a reduction in the numerical density of cells per area. Changes in brain and head sizes and in the thickness of the cell layers of the forebrain and midbrain were significant at 10 mg/L PPF. Notably, PPF caused DNA doublestrand breaks and induced apoptosis in embryos exposed to 10 mg/L, which were accompanied by a reduction in cell proliferation. Regarding neuronal and glial differentiation, no changes were observed in the number of neurons and glial cells on the analyzed layers. Furthermore, PPF did not impact the head ossification process. These findings reveal that PPF is a strong stressor for neurodevelopment, causing damage to the cell architecture of brain vesicles.

Per- and polyfluoroalkyl substances (PFAS) during oocyte maturation and the effect on early porcine embryo development and apoptosis in vitro

Per- and polyfluoroalkyl substances (PFAS) during oocyte maturation and the effect on early porcine embryo development and apoptosis in vitro

Real-Time Visualization of Embryonic Apoptosis Using a Near-Infrared Fluorogenic Probe for Embryo Development Evaluation.

Developing an accurate and reliable detection technique for early embryonic apoptosis is of great significance for real-time monitoring and evaluation of embryonic development in living systems. Herein, we have rationally designed and synthesized a novel near-infrared (NIR) fluorogenic probe CGK(QSY21)DEVD-Cy5.5 for real-time imaging of embryonic apoptosis. This probe is constructed with a NIR dye Cy5.5, a fluorescence quencher QSY21, and a peptide substrate Asp-Glu-Val-Asp (DEVD) of the caspase-3 enzyme that is a key executor of cell apoptosis. The probe was initially nonfluorescent in aqueous solution but emitted strong NIR fluorescence upon specific cleavage by activated caspase-3 in a concentration-dependent manner. Taking advantage of this unique feature, this fluorogenic probe was for the first time used for real-time imaging of caspase-3 activity in apoptotic embryos. More notably, significant fluorescence enhancement was solely determined from the apoptotic embryos with the treatment of the probe both in vitro and in vivo, highly suggesting that this probe has great potential to monitor the apoptosis of embryos. We thus envision that this probe would provide a very useful means for real-time visualization and accurate evaluation of embryonic development in the future.

Exposure to citrinin induces DNA damage, autophagy, and mitochondria dysfunction during first cleavage of mouse embryos.

Citrinin (CTN) is a mycotoxin, which is isolated from Penicillium citrinum and widely existed in the contaminated feeds. It is reported that CTN is toxic to heart, liver, and reproductive system. Previous studies indicated that CTN induced apoptosis in oocytes and embryos. In this study, we reported the potential causes of CTN on embryo development. Our results showed that 40 μM CTN exposure significantly reduced the first cleavage of mouse embryos, showing with the low rate of 2-cell embryos. We found that CTN induced DNA damage, showing the higher positive γH2A.X signals. Autophagy was occurred since more LC3 positive autophagosomes were found in the cytoplasm. This could be confirmed by the enhanced lysosome function, since higher accumulated lysosome distribution were found and LAMP2 was also increased under CTN exposure. Besides, we showed that mitochondria distribution was disturbed, indicating that CTN could disrupt mitochondria function, which could be the possible reason for the oxidative stress and apoptosis in CTN-exposed embryos. In conclusion, our study showed that CTN exposure had adverse effects on the early embryo development during first cleavage through its effects on the induction of DNA damage, autophagy, and mitochondria dysfunction.

Melatonin improves the first cleavage of parthenogenetic embryos from vitrified\u2013warmed mouse oocytes potentially by promoting cell cycle progression

BackgroundThis study investigated the effect of melatonin (MT) on cell cycle (G1/S/G2/M) of parthenogenetic zygotes developed from vitrified-warmed mouse metaphase II (MII) oocytes and elucidated the potential mechanism of MT action in the first cleavage of embryos.ResultsAfter vitrification and warming, oocytes were parthenogenetically activated (PA) and in vitro cultured (IVC). Then the spindle morphology and chromosome segregation in oocytes, the maternal mRNA levels of genes including Miss, Doc1r, Setd2 and Ythdf2 in activated oocytes, pronuclear formation, the S phase duration in zygotes, mitochondrial function at G1 phase, reactive oxygen species (ROS) level at S phase, DNA damage at G2 phase, early apoptosis in 2-cell embryos, cleavage and blastocyst formation rates were evaluated. The results indicated that the vitrification/warming procedures led to following perturbations 1) spindle abnormalities and chromosome misalignment, alteration of maternal mRNAs and delay in pronucleus formation, 2) decreased mitochondrial membrane potential (MMP) and lower adenosine triphosphate (ATP) levels, increased ROS production and DNA damage, G1/S and S/G2 phase transition delay, and delayed first cleavage, and 3) increased early apoptosis and lower levels of cleavage and blastocyst formation. Our results further revealed that such negative impacts of oocyte cryopreservation could be alleviated by supplementation of warming, recovery, PA and IVC media with 10− 9 mol/L MT before the embryos moved into the 2-cell stage of development.ConclusionsMT might promote cell cycle progression via regulation of MMP, ATP, ROS and maternal mRNA levels, potentially increasing the first cleavage of parthenogenetic zygotes developed from vitrified–warmed mouse oocytes and their subsequent development.

Alternariol exerts embryotoxic and immunotoxic effects on mouse blastocysts through ROS-mediated apoptotic processes.

Alternariol (AOH), a mycotoxin belonging to the genus Alternaria, has been shown to induce cytotoxicity, including apoptosis and cell cycle arrest, in several mammalian cell types. However, its effects on early-stage embryonic development require further investigation. Here, we have shown that AOH exerts embryotoxic effects on mouse blastocyst-stage embryos and long-term adverse effects on immunity in one-day-old newborn mice of the next generation. Significant apoptosis and decrease in total cell number, predominantly through loss of inner cell mass (ICM), and to a minor extent, trophectoderm (TE) cells, were observed in AOH-treated blastocysts. Moreover, AOH exerted detrimental effects on pre- and post-implantation embryo development potential and induced a decrease in fetal weight in in vitro development and embryo transfer assays. Injection of pregnant mice with AOH (1, 3 and 5mg/kg body weight/day) for 4days resulted in apoptosis of blastocyst-stage embryos and injurious effects on embryonic development from the zygote to blastocyst stage or embryo degradation and a further decrease in fetal weight. Furthermore, AOH exerted a long-term impact on the next generation, triggering a significant increase in total oxidative stress content and expression of genes encoding antioxidant proteins. Lower expression of CXCL1, IL-1β and IL-8 related to innate immunity was detected in liver tissue extracts obtained from one-day-old newborns of AOH-injected pregnant mice (5mg/kg body weight/day) relative to their non-treated counterparts. In addition, ROS served as an upstream regulator of AOH-triggered apoptotic processes and impairment of embryonic development. Our collective results highlight the potential of AOH as an embryotoxic and immunotoxic risk factor during embryo and infant development stages in mice.

E3 ligase activity of Carboxyl terminus of Hsc70 interacting protein (CHIP) in Wharton's jelly derived mesenchymal stem cells improves their persistence under hyperglycemic stress and promotes the prophylactic effects against diabetic cardiac damages.

Recent studies indicate that umbilical cord stem cells are cytoprotective against several disorders. One critical limitation in using stem cells is reduction in their viability under stressful conditions, such as diabetes. However, the molecular intricacies responsible for diabetic conditions are not fully elucidated. In this study, we found that high glucose (HG) conditions induced loss of chaperone homeostasis, stabilized PTEN, triggered the downstream signaling cascade, and induced apoptosis and oxidative stress in Wharton's jelly derived mesenchymal stem cells (WJMSCs). Increased Carboxyl terminus of Hsc70 interacting protein (CHIP) expression promoted phosphatase and tensin homolog (PTEN) degradation via the ubiquitin‐proteasome system and shortened its half‐life during HG stress. Docking studies confirmed the interaction of CHIP with PTEN and FOXO3a with the Bim promoter region. Further, it was found that the chaperone system is involved in CHIP‐mediated PTEN proteasomal degradation. CHIP depletion stabilizes PTEN whereas PTEN inhibition showed an inverse effect. CHIP overactivation suppressed the binding of FOXO3a with bim. Coculturing CHIP overexpressed WJMSCs suppressed HG‐induced apoptosis and oxidative stress in embryo derived cardiac cell lines. CHIP overexpressing and PTEN silenced WJMSCs ameliorated diabetic effects in streptozotocin (STZ) induced diabetic rats and further improved their body weight and heart weight, and rescued from hyperglycemia‐induced cardiac injury. Considering these, the current study suggests that CHIP confers resistance to apoptosis and acts as a potentiation factor in WJMSCs to provide protection from degenerative effects of diabetes.

Differential Effects of Bisphenol A and Di (2-Ethylhexyl) Phthalate Exposure on Crestin and the Expression of Some Genes Related to Apoptosis and Inflammation in Zebrafish Embryos

Objective: Endocrine disrupting chemicals (EDC) in plastics may disrupt proper endocrine system functioning. Zebrafish embryos are formed through external fertilization, and their rapid development, short life cycle, and transparency provide imaging advantages. In zebrafish embryos, neural crest development occurs similarly to other vertebrate embryos and crestin is found in the neural crest during embryogenesis. The aim of our study is to evaluate the effects of bisphenol A (BPA) and Di (2-ethylhexyl) phthalate (DEHP), which are the most widely used EDCs, on the expression of crestin, apoptosis, and inflammation-related parameters in zebrafish embryos. Materials and Methods: The embryos were exposed to either DEHP or BPA in well plates for 72 h post fertilization (hpf). Expressions of crestin were evaluated by in situ hybridization, while the expressions of bax, casp8, casp3a, ifng1, fas, and tp53 were evaluated by RT-PCR. Results: Expressions of bax and casp8 increased and casp3a, ifng1, and fas decreased in BPA and DEHP groups. tp53 expression increased in the BPA group but decreased in the DEHP group compared with the control group. In the DEHP group, casp3a, ifng1, fas, bax, casp8, and tp53 expressions decreased compared with the BPA group. No significant change was observed in the crestin expressions in the groups. When compared with the control group, an inverse relation between ifng1 expression and apoptosis, as evidenced by increased bax and casp8 expressions, was observed in the BPA and DEHP groups. Conclusion: Our study provided important data on the effects of EDCs on the relationship between inflammation and apoptosis.

Alpha-Lipoic Acid Can Overcome The Reduced Developmental Competency Induced by Alcohol Toxicity during Ovine Oocyte Maturation.

Objective Alpha-lipoic acid (ALA) as a strong antioxidant has a protective effect. This study was designed to assess whether supplementation of maturation medium with ALA during in vitro maturation (IVM) can attenuate the toxic effect of ethanol. Materials and Methods In this experimental study, to assess the antioxidant capacity of ALA challenged by 1% ethanol during in vitro maturation, immature ovine oocytes were exposed to 1% alcohol in the presence or absence of 25 µM ALA during oocyte maturation. The cumulus expansion index, intracellular reactive oxygen species (ROS), and thiol content levels were assessed in matured oocytes of various treatment groups. Consequently, the blastocyst formation rate of matured oocytes in various treatment groups were assessed. In addition, total cell number (TCN), cell allocation, DNA fragmentation, and relative gene expression of interested genes were assessed in resultant blastocysts. Results The results revealed that alcohol significantly reduced cumulus cells (CCs) expansion index and blastocyst yield and rate of apoptosis in resultant embryos. Addition of 25 µM ALA to 1% ethanol during oocyte maturation decreased ROS level and elevated Thiolcontent. Furthermore, supplementation of maturation medium with ALA attenuated the effect of 1% ethanol and significantly increased the blastocyst formation and hatching rate as compared to control and ethanol groups. In addition, the quality of blastocysts produced in ALA+ethanol was improved based on the low number of TUNEL positive cells, the increased expression level of mRNA for pluripotency, and anti-oxidant markers, and decreased expression of apoptotic genes. ConclusionThe current findings demonstrate that ALA can diminish the effect of ethanol, possibly by decreasing the ROS level and increasing Thiolcontent during oocyte maturation. Using the ALA supplement may have implications in protecting oocytes from alcohol toxicity in affected patients.

Involvement of Nrf2-HO-1/JNK-Erk Signaling Pathways in Aconitine-Induced Developmental Toxicity, Oxidative Stress, and ROS-Mitochondrial Apoptosis in Zebrafish Embryos.

Aconitine (AC), one of the bioactive diterpenoid alkaloids extracted from Aconitum plants, is widely used in traditional herbal medicine to treat various diseases. Emerging evidence indicates that AC has attracted great interest for its wide cardiotoxicity and neurotoxicity. However, the toxic effects of AC on embryonic development and its underlying mechanisms remain unclear. Here, a developmental toxicity assay of AC was performed on zebrafish embryos from 4 to 96 h post fertilization (hpf), and its underlying mechanisms were discussed. AC exposure impaired the cardiac, liver, and neurodevelopment. Especially, a high dose of AC (7.27 and 8.23 μM) exposure resulted in malformations at 72 and 96 hpf, including reduced body length, curved body shape, pericardial edema, yolk retention, swim bladder and brain developmental deficiency, and degeneration of dopaminergic neurons. High-concentration AC exposure caused a deficient cardiovascular system with cardiac dysfunctions, increased heart rates at 72 and 96 hpf, and reduced locomotor behavior at 120 hpf. AC treatment significantly increased the ROS level and triggered cell apoptosis in the heart and brain regions of embryos at 96 hpf in 7.27 and 8.23 μM AC treatment zebrafish. Oxidative stress was confirmed by reduced levels of T-SOD activity associated with accumulation of lipid peroxidation in larvae. The expression levels of oxidative stress-related genes (Nrf2, HO-1, Cat, and Sod-1) Erk1/2 and Bcl-2 were significantly downregulated at 96 hpf. The expression pattern of JNK and mitochondrial apoptosis-related genes (Bad, Bax, Cyto C, Casp-9, and Casp-3) was significantly upregulated. Taken together, all these parameters collectively provide the first evidence of AC-induced developmental toxicity in zebrafish embryo/larvae through ROS-medicated mitochondrial apoptosis involving Nrf2/HO-1 and JNK/Erk pathways.

Melatonin protects against defects induced by Enniatin B1 during porcine early embryo development.

Exogenous factors influence embryo development. Enniatin B1 (EB1), one emerging mycotoxin of Fusarium fungi, can cause damage to cells and mouse blastocysts. However, the toxicity of EB1 on porcine embryo development and whether melatonin can eliminate the detrimental effects of EB1 on embryos remain unclear. Here, this work demonstrated that EB1 significantly decreased the cleavage and blastocyst rates and blastocyst cell number of embryos in a dose and time dependent manner. Further study displayed that EB1 obviously destroyed nuclear remodeling dynamics. Importantly, EB1 triggered embryo apoptosis through downregulating the expression of Sod1, Gpx4, Cat and Bcl2l1 while upregulating the transcription of Bax and Caspase3. Moreover, EB1 significantly disrupted the transcription of Dnmt1, Dnmt3a, Tet1 and Tet3, further leading to incomplete DNA demethylation of CenRep, Oct4, Nanog and Sox2, thus, the expression of Eif1a, Oct4, Nanog and Sox2 remarkably decreased. Whereas EB1-exposed embryos were treated with melatonin, these disorders were obviously ameliorated, and the development ability of embryos was also rescued. In conclusion, EB1 exerted detrimental effects on porcine early embryos, while melatonin effectively rescued EB1-mediated defects in embryos. This work provides a novel insight into the improvement of embryo quality and the promotion of human and animal reproduction.

Aclonifen causes developmental abnormalities in zebrafish embryos through mitochondrial dysfunction and oxidative stress

The herbicide aclonifen is commonly used in agriculture. Aclonifen is toxic to experimental animals, causing developmental abnormalities, decreased energy production for survival, and impaired organogenesis. However, no studies have reported the functional defects and toxicity caused by aclonifen in embryonic development. We hypothesized that the mechanism underlying the toxicity of several herbicides in various organisms involves mitochondrial dysfunction, which subsequently promotes genotoxicity, cytotoxicity, and acute organotoxicity. In the present study, we demonstrated that mitochondrial dysfunction during development results in decreased body length, delayed yolk sac absorption, malformed spinal cord, disrupted brain and eye formation, and the activation of apoptosis in zebrafish embryos. Aclonifen induced oxidative stress by elevating the level of reactive oxygen species, causing mitochondrial damage. Likewise, impaired embryonic vascularization can promote cardiovascular disorders. In this study, we characterized the toxicity of aclonifen in a non-target organism. These findings increase our understanding of the toxicological effects of herbicides in unexpected environments.

MicroRNA-210 Regulates Endoplasmic Reticulum Stress and Apoptosis in Porcine Embryos.

Simple SummaryThe purpose of this study was to explore the effect of miR-210 on in vitro embryo development, mRNA expression related endoplasmic reticulum (ER) stress. Treatment with a miR-210-inhibitor significantly improved in vitro embryo development and total blastocyst cell number (TCN). Furthermore, miR-210-inhibitor treatment downregulated ER stress and apoptosis-related gene expression, while simultaneously improving embryo capacity. In contrast, a miR-210-mimic decreased in vitro embryo development, TCN, upregulated ER stress and apoptosis genes, and concomitantly impaired embryo quality. Therefore, we suggest that miR-210 plays an important role in porcine in vitro embryo development.Endoplasmic reticulum (ER) stress can be triggered during in vitro embryo production and is a major obstacle to embryo survival. MicroRNA (miR)-210 is associated with cellular adaptation to cellular stress and inflammation. An experiment was conducted to understand the effects of miR-210 on in vitro embryo development, ER stress, and apoptosis; to achieve this, miR-210 was microinjected into parthenogenetically activated embryos. Our results revealed that miR-210 inhibition significantly enhanced the cleavage rate, blastocyst formation rate, and total cell number (TCN) of blastocysts, and reduced expression levels of XBP1 (p < 0.05). miR-210 inhibition greatly reduced the expression of ER stress-related genes (uXBP1, sXBP1, ATF4, and PTPN1) and Caspase 3 and increased the levels of NANOG and SOX2 (p < 0.05). A miR-210-mimic significantly decreased the cleavage, blastocyst rate, TCN, and expression levels of XBP1 compared with other groups (p < 0.05). The miR-210-mimic impaired the expression levels of uXBP1, sXBP1, ATF4, PTPN1, and Caspase 3 and decreased the expression of NANOG and SOX2 (p < 0.05). In conclusion, miR-210 plays an essential role in porcine in vitro embryo development. Therefore, we suggest that miR-210 inhibition could alleviate ER stress and reduce apoptosis to support the enhancement of in vitro embryo production.

Determining factors for the nano-biocompatibility of cobalt oxide nanoparticles: proximal discrepancy in intrinsic atomic interactions at differential vicinage

In vivo and in vitro Intrinsic atomic interaction of Cobalt oxide nanoparticles (Co3O4) describe the differential nano-biocompatibility.

Rescue Potential of Supportive Embryo Culture Conditions on Bovine Embryos Derived from Metabolically Compromised Oocytes.

Elevated non-esterified fatty acid (NEFA), predominantly palmitic acid (PA), concentrations in blood and follicular fluid are a common feature in maternal metabolic disorders such as obesity. This has a direct negative impact on oocyte developmental competence and the resulting blastocyst quality. We use NEFA-exposure during bovine oocyte in vitro maturation (IVM) as a model to mimic oocyte maturation under maternal metabolic stress conditions. However, the impact of supportive embryo culture conditions on these metabolically compromised zygotes are not known yet. We investigated if the addition of anti-apoptotic, antioxidative and mitogenic factors (namely, Insulin-Transferrin-Selenium (ITS) or serum) to embryo culture media would rescue development and important embryo quality parameters (cell proliferation, apoptosis, cellular metabolism and gene expression patterns) of bovine embryos derived from high PA- or high NEFA-exposed oocytes when compared to controls (exposed to basal NEFA concentrations). ITS supplementation during in vitro culture of PA-exposed oocytes supported the development of lower quality embryos during earlier development. However, surviving blastocysts were of inferior quality. In contrast, addition of serum to the culture medium did not improve developmental competence of PA-exposed oocytes. Furthermore, surviving embryos displayed higher apoptotic cell indices and an aberrant cellular metabolism. We conclude that some supportive embryo culture supplements like ITS and serum may increase IVF success rates of metabolically compromised oocytes but this may increase the risk of reduced embryo quality and may thus have other long-term consequences.

MicroRNA-135a Protects Against Ethanol-Induced Apoptosis in Neural Crest Cells and Craniofacial Defects in Zebrafish by Modulating the Siah1/p38/p53 Pathway.

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in various biological processes, including apoptosis, by regulating gene expression. This study was designed to test the hypothesis that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in neural crest cells (NCCs) by upregulating Siah1 and activating the p38 mitogen-activated protein kinase (MAPK)/p53 pathway. We found that treatment with ethanol resulted in a significant decrease in miR-135a expression in both NCCs and zebrafish embryos. Ethanol-induced downregulation of miR-135a resulted in the upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and increased apoptosis in NCCs and zebrafish embryos. Ethanol exposure also resulted in growth retardation and developmental defects that are characteristic of fetal alcohol spectrum disorders (FASD) in zebrafish. Overexpression of miRNA-135a significantly reduced ethanol-induced upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and decreased ethanol-induced apoptosis in NCCs and zebrafish embryos. In addition, ethanol-induced growth retardation and craniofacial defects in zebrafish larvae were dramatically diminished by the microinjection of miRNA-135a mimics. These results demonstrated that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in NCCs by upregulating Siah1 and activating the p38 MAPK/p53 pathway and that the overexpression of miRNA-135a can protect against ethanol-induced apoptosis in NCCs and craniofacial defects in a zebrafish model of FASD.

The SPOM-adapted IVM system improves in vitro production of bovine embryos

This study aimed to test the effects of an IVM SPOM adaptation (SPOM-adapted IVM) on the production, total number of cells (TNC), apoptosis, and cryotolerance (post-warming survival and cytoskeleton actin integrity) of bovine IVP embryos. Two experiments were conducted with two experimental groups based on IVM treatment: A control group (TCM 199 without FCS) and an SPOM-adapted group (TCM 199 with forskolin and IBMX in pre-IVM and IVM with cilostamide). The first experiment evaluated embryo in vitro production, TNC, and apoptosis rate on D9 of development. In the second experiment, embryos were vitrified/warmed at D7 (control fresh and vitrified; SPOM-adapted fresh and vitrified) and assessed regarding post-warming survival rates and cytoskeleton actin integrity. Statistical analysis was performed using GraphPad INSTAT software at a significance level of 5%. An increase (p < 0.05) in blastocyst production was observed in the SPOM-adapted group comparing to the control group. There was no difference (p > 0.05) in the TNC or apoptosis rate between the groups. Regarding cryopreservation, no differences were found (p > 0.05) in actin integrity or post-warming survival rates between the vitrified groups. In both vitrified groups, we observed a significantly lower uninjured pattern of actin integrity compared to the fresh groups (p < 0.05). We conclude that the SPOM-adapted IVM system is beneficial for blastocyst production and does not affect the quality and cryotolerance of the produced embryos.

The Unique Cysteine of F-ATP Synthase OSCP Subunit Participates in Modulation of the Permeability Transition Pore

The mitochondrial permeability transition pore (PTP) is a Ca2+-activated channel that plays a key role in cell death. Thiol oxidation facilitates PTP opening, yet the targets and molecular mechanisms still await a definition. Here, we investigate the role of C141 of F-ATP synthase oligomycin sensitivity conferral protein (OSCP) subunit in PTP modulation by oxidation. We find that the OSCP C141S mutation confers resistance to PTP opening and cell death by diamide and MitoParaquat only when cyclophilin D (CyPD) has been ablated, a protective role that can be explained by CyPD shielding C141 from oxidants. The mutation decreases apoptosis in zebrafish embryos, indicating that this OSCP residue is involved in development. Site-directed mutagenesis in yeast suggests that other conserved cysteines in the α, γ, and c subunits of F-ATP synthase are not involved in PTP modulation. Thus, OSCP provides a strategic site that regulates PTP opening by the interplay between CyPD (un)binding and thiol oxidation-reduction.

Developmental toxicity triggered by benzyl alcohol in the early stage of zebrafish embryos: Cardiovascular defects with inhibited liver formation and degenerated neurogenesis

Benzyl alcohol (BnOH) is an aromatic alcohol used worldwide as an excipient in foods, cosmetics, household products, and medications. Although BnOH is a bacteriostatic agent found in many parenteral preparations, this agent is responsible for precipitating the gasping syndrome in premature neonates. Increasing evidence of human exposure to BnOH and environmental contamination of BnOH requires a detailed toxicity assessment of this aromatic chemical. Few studies on the toxicity of BnOH have been reported on different animal models, but its developmental toxicity effects are not fully understood yet. Studies on the effects of BnOH on the specific endpoints of organ toxicity are rare. Thus, the present study aimed to examine the developmental toxicity effects of BnOH by using zebrafish (Danio rerio) embryo as a biological disease model. Four-hour post fertilization zebrafish embryos were exposed to BnOH for 72 h to assess BnOH toxicity on an ecological viewpoint. The median lethal concentrations of varying BnOH concentrations in zebrafish embryos were estimated. The embryonic toxicity induced by BnOH was revealed by the apoptosis in embryos and pathological alterations, such as increased mortality, inhibited hatching rate, and decreased somite number. Moreover, pericardial edema and string heartbeat were observed because of arrhythmia and cardiac malformation. The number of normal vessels in the head and trunk regions was remarkably reduced in transgenic zebrafish line Tg (Fli-1: EGFP). Morphological defects and yolk sac retention were related to the degenerated liver formation in Tg (Lfabp: dsRED). Furthermore, BnOH exposure led to the disruption of motor neuron axonal integrity and the alteration of the axon pattern in Tg (olig2: dsRED). In addition, the results exhibited the pathological effects of BnOH exposure on major organs. We believe that this study is the second to report the developmental organ toxicity of BnOH to zebrafish embryos. This study provides important information for further elucidating the mechanism of BnOH-induced developmental organ toxicity.

3-Pyridinylboronic acid normalizes the effects of 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposure in zebrafish embryos

1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) is a neurotoxin that damages dopaminergic neurons. Zebrafish has been shown to be a suitable model organism to investigate the molecular pathways in the pathogenesis of Parkinson’s disease and also for potential therapeutic agent research. Boron has been shown to play an important role in the neural activity of the brain. Boronic acids are used in combinatorial approaches in drug design and discovery. The effect of 3-pyridinylboronic acid which is an important sub-class of heterocyclic boronic acids has not been evaluated in case of MPTP exposure in zebrafish embryos. Accordingly, this study was designed to investigate the effects of 3-pyridinylboronic acid on MPTP exposed zebrafish embryos focusing on the molecular pathways related to neurodegeneration and apoptosis by RT-PCR. Zebrafish embryos were exposed to MPTP (800 μM); MPTP + Low Dose 3-Pyridinylboronic acid (50 μM) (MPTP + LB) and MPTP + High Dose 3-Pyridinylboronic acid (100 μM) (MPTP + HB) in well plates for 72 hours post fertilization. Results of our study showed that MPTP induced a P53 dependent and Bax mediated apoptosis in zebrafish embryos and 3-pyridinylboronic acid restored the locomotor activity and gene expressions related to mitochondrial dysfunction and oxidative stress due to the deleterious effects of MPTP, in a dose-dependent manner.