Carbofuran accelerates the cellular senescence and declines the life span of spns1 mutant zebrafish

Oseltamivir enhances 5-FU sensitivity in esophageal squamous carcinoma with high SPNS1

Sphingolipid transporter 1 (SPNS1) is a significant differentially expressed gene (DEGs) in esophageal squamous cell carcinoma (ESCC). According to 3 pairs clinic cohorts, transcriptomic (155 pairs of ESCC samples and GSE53624, and proteomic data from PXD021701 including 124 ESCC samples) we found that SPNS1 was significantly higher in ESCC tissues compared to adjacent normal esophagus tissues. ESCC patients with high SPNS1 had a significantly poorer clinical prognosis than those with low SPNS1. Knockdown of SPNS1 significantly inhibited the proliferation, migration, and invasion abilities of ESCC cells, while promoting apoptosis. And overexpression of SPNS1 exhibited opposite functions. Furthermore, ESCC cells became more sensitive to 5-fluorouracil (5-FU) when SPNS1 was knocked down. Transcriptome sequencing revealed that NEU1 was one significant DEG affected by SPNS1 and positively correlated with SPNS1 expression. Oseltamivir phosphate (OP), one NEU1 inhibitor, markedly reversed 5-FU resistance, migration, and proliferation induced by high expression of SPNS1 both in vivo and in vitro. Our findings indicated that SPNS1 might promote the progression of ESCC by upregulating NEU1 expression and influencing chemotherapy sensitivity. These results provide new perceptions into potential therapeutic targets for ESCC treatment. The present study aimed to investigate the role and underlying mechanism of SPNS1 in ESCC.

The adsorption effects of biochar on carbofuran in water and the mixture toxicity of biochar-carbofuran in rats

Carbofuran, a widely used carbamate insecticide, is frequently detected in water. In this study, a high-performance adsorbent (WAB4) for carbofuran was obtained from laboratory-synthesized biochars. The maximum adsorption of carbofuran by WAB4 reaches 113.7 mg/g approximately. The adsorption of carbofuran by biochar was a multi-molecular layer and the adsorption process conforms to the pseudo-second-order kinetic model (R2 = 0.9984) and Freundlich isotherm model (R2 = 0.99). Importantly, an in vivo rat model was used to assess the combined toxicological effects of biochar-carbofuran complexes. The toxicity of the complexes (LD50 > 12 mg/kg) is lower than that of carbofuran (LD50 = 7.9 mg/kg) alone. The damage of biochar-carbofuran complex on rat liver and lung is significantly less than that of carbofuran. The Cmax and bioavailability of carbofuran were found to be reduced by 64% and 68%, respectively, when biochar was present, by UPLC-MS/MS analysis of carbofuran in rat plasma. Furthermore, it was confirmed that the biochar-carbofuran complex is relatively stable in the gastrointestinal tract, by performing a carbofuran release assay in artificial gastrointestinal fluids in vitro. Collectively, biochar is a bio-friendly material for the removal of carbofuran from water.

Effects of the Pesticide Carbofuran on Two Species of Chlorophyceae (Desmodesmus communis and Pseudopediastrum boryanum) and Their Pesticide Bioremediation Ability

Carbofuran is one of the most toxic broad-spectrum pesticides. We evaluated the effects of carbofuran on two species of microalgae, Pseudopediastrum boryanum and Desmodesmus communis, through measurements of cell viability, biomass, chlorophyll content, and the production of reactive oxygen species (ROS). The ability of these algae to remove carbofuran dissolved in the media was also determined. For the evaluations, both microalgae species were exposed to carbofuran (FURADAN 350 SC®) at concentrations of 100, 1000, and 10,000 µg L-1 for 7 days. Algae cell viability and chlorophyll-a concentration were not affected by the presence of carbofuran. Both species grew when exposed to the pesticide; however, the microalgae D. communis grew less than its respective control when exposed to the highest concentration (10,000 µg L-1 of carbofuran), indicating an adverse effect of the pesticide on this species. A significant increase in ROS production was observed in D. communis and P. boryanum when exposed to the highest concentration tested. The microalgae P. boryanum completely removed carbofuran in the media within 2 days, regardless of the concentration, whereas D. communis achieved the same result only after 5 days of exposure. Growth inhibition was observed only until the disappearance of carbofuran from the media. The present study suggests the use of microalgae, mainly P. boryanum, as potential tools for the remediation of environments contaminated by carbofuran because of their resistance to the insecticide and their ability to remove it rapidly from water. Environ Toxicol Chem 2024;00:1-12. © 2023 SETAC.

Deficiency of spns1 exacerbates per- and polyfluoroalkyl substances mediated hepatic toxicity and steatosis in zebrafish (Danio rerio)

Per- and polyfluoroalkyl substances (PFAS) are man-made long-lasting chemical compounds that are found in everyday household items. Today they occur in the environment as a major group of pollutants. These compounds are broadly used in commercial product preparation such as, for food packaging, nonstick coatings, and firefighting foam. In humans, PFAS can cause immune disorders, impaired fetal development, abnormal skeletal tissue development, osteoarthritis, thyroid dysfunctions, cholesterol changes, affect insulin regulation and lipid metabolism, and are also involved in the development of fatty liver disease. In the current study, we investigated the effect of low, but physiologically relevant, concentrations of perfluorooctanoic acid (PFOA), heptafluorobutyric acid (HFBA), and perfluorotetradecanoic acid (PFTA) on gene expression markers of an inflammatory response (tnfa, il-1b, il-6, rplp0, edem1, and dnajc3a), unfolded protein response (UPR) (bip, atf4a, atf6, xbp1, and ddit3), senescence (p21, pai1, smp30, mdm2, and baxa), lipogenesis (scd1, acc, srebp1, pparγ, and fasn) and autophagy (p62, atg3, atg7, rab7, lc3b, and becn1) in AB wild-type (+/+), spns1-wt sibling (+/+), (+/-) and spns1 homozygous mutant (-/-) zebrafish embryos. Exposure to PFOA and HFBA (50 and 100 nM) specifically modulated inflammatory, UPR, senescence, lipogenic, and autophagy signaling in spns1-wt (+/+), (+/-), and spns1-mutant (-/-) zebrafish embryos. Furthermore, PFOA, but not HFBA, upregulated lipogenic-related gene expression and enhanced hepatic steatosis in spns1-wt (+/+), (+/-) zebrafish embryos. Combined exposure to PFOA, HFBA, and PFTA differentially expressed inflammatory, senescence, lipogenic, and autophagy-associated gene expression in spns1-mutant (-/-) zebrafish embryos compared with spns1-wt (+/+), (+/-) and AB-wt (+/+) zebrafish embryos. In addition, chronic exposure (∼2 months) to PFOA (120-600 nM) upregulated the expression of hepatic lipogenic and steatosis biomarkers in AB-wt (+/+) zebrafish. Collectively, our data suggest that acute/chronic physiologically relevant concentrations of PFOA upregulate inflammatory, UPR, senescence, and lipogenic signaling in spns1-wt (+/+), (+/-) and spns1-mutant (-/-) zebrafish embryos as well as in two-month-old AB-wt zebrafish, by targeting autophagy and hence induces toxicity that could promote nonalcoholic fatty liver disease.

Endosulfan affects embryonic development synergistically under elevated ambient temperature

In the present study, we determined the developmental toxicity of endosulfan at an elevated ambient temperature using the zebrafish animal model. Zebrafish embryos of various developmental stages were exposed to endosulfan through E3 medium, raised under two selected temperature conditions (28.5 °C and an elevated temperature of 35 °C), and monitored under the microscope. Zebrafish embryos of very early developmental stages (cellular cleavage stages, such as the 64-cell stage) were highly sensitive to the elevated temperature as 37.5% died and 47.5% developed into amorphous type, while only 15.0% of embryos developed as normal embryos without malformation. Zebrafish embryos that were exposed concurrently to endosulfan and an elevated temperature showed stronger developmental defects (arrested epiboly progress, shortened body length, curved trunk) compared to the embryos exposed to either endosulfan or an elevated temperature. The brain structure of the embryos that concurrently were exposed to the elevated temperature and endosulfan was either incompletely developed or malformed. Furthermore, the stress-implicated genes hsp70, p16, and smp30 regulations were synergistically affected by endosulfan treatment under the elevated thermal condition. Overall, the elevated ambient temperature synergistically enhanced the developmental toxicity of endosulfan in zebrafish embryos.

Carbofuran pesticide toxicity to the eye

Pesticide exposure to eyes is a major source of ocular morbidities in adults and children all over the world. Carbofuran (CF), N-methyl carbamate, pesticide is most widely used as an insecticide, nematicide, and acaricide in agriculture, forestry, and gardening. Contact or ingestion of carbofuran causes high morbidity and mortality in humans and pets. Pesticides are absorbed in the eye faster than other organs of the body and damage ocular tissues very quickly. Carbofuran exposure to eye causes blurred vision, pain, loss of coordination, anti-cholinesterase activities, weakness, sweating, nausea and vomiting, abdominal pain, endocrine, reproductive, and cytotoxic effects in humans depending on amount and duration of exposure. Pesticide exposure to eye injures cornea, conjunctiva, lens, retina, and optic nerve and leads to abnormal ocular movement and vision impairment. Additionally, anticholinesterase pesticides like carbofuran are known to cause salivation, lacrimation, urination, and defecation (SLUD). Carbofuran and its two major metabolites (3-hydroxycarbofuran and 3-ketocarbofuran) are reversible inhibitors of acetylcholinesterase (AChE) which regulates acetylcholine (ACh), a neurohumoral chemical that plays an important role in corneal wound healing. The corneal epithelium contains high levels of ACh whose accumulation by AChE inhibition after CF exposure overstimulates muscarinic ACh receptors (mAChRs) and nicotinic ACh receptors (nAChRs). Hyper stimulation of mAChRs in the eye causes miosis (excessive constriction of the pupil), dacryorrhea (excessive flow of tears), or chromodacryorrhea (red tears). Recent studies reported alteration of autophagy mechanism in human cornea in vitro and ex vivo post carbofuran exposure. This review describes carbofuran toxicity to the eye with special emphasis on corneal morbidities and blindness.

Lysosomal Function Impacts the Skeletal Muscle Extracellular Matrix

Muscle development and homeostasis are critical for normal muscle function. A key aspect of muscle physiology during development, growth, and homeostasis is modulation of protein turnover, the balance between synthesis and degradation of muscle proteins. Protein degradation depends upon lysosomal pH, generated and maintained by proton pumps. Sphingolipid transporter 1 (spns1), a highly conserved gene encoding a putative late endosome/lysosome carbohydrate/H⁺ symporter, plays a pivotal role in maintaining optimal lysosomal pH and spns1^−/− mutants undergo premature senescence. However, the impact of dysregulated lysosomal pH on muscle development and homeostasis is not well understood. We found that muscle development proceeds normally in spns1^−/− mutants prior to the onset of muscle degeneration. Dysregulation of the extracellular matrix (ECM) at the myotendinous junction (MTJ) coincided with the onset of muscle degeneration in spns1^−/− mutants. Expression of the ECM proteins laminin 111 and MMP-9 was upregulated. Upregulation of laminin 111 mitigated the severity of muscle degeneration, as inhibition of adhesion to laminin 111 exacerbated muscle degeneration in spns1^−/− mutants. MMP-9 upregulation was induced by tnfsf12 signaling, but abrogation of MMP-9 did not impact muscle degeneration in spns1^−/− mutants. Taken together, these data indicate that dysregulated lysosomal pH impacts expression of ECM proteins at the myotendinous junction.

Carbofuran affects cellular autophagy and developmental senescence through the impairment of Nrf2 signalling

Carbofuran is a broad-spectrum synthetic pesticide. Its exposure to non-target mammals affects the biological system through the induction of oxidative stress. Since oxidative stress is a major contributing factor to cellular autophagy and senescence, our present investigation determined the impacts of carbofuran-induced oxidative stress on cellular autophagy and senescence. A transmembrane protein, Spinster homolog 1 (Spns1), is involved in autophagic lysosomal metabolism. Its mutation accelerates the cellular senescence and shortens the lifespan. Using a transgenic zebrafish line, expressing fluorescent microtubules-associated protein 1 light chain 3 (EGFP-LC3) at the membrane of the autophagosome, we found that carbofuran affects autophagic lysosomal biogenesis in wild-type zebrafish and exacerbates autophagic defect in spns1-mutant zebrafish. In real-time mortality study, carbofuran has shortened the lifespan of wild-type fish. Nrf2 is a stress-responsive transcription factor that regulates the expression of antioxidant genes (such as gstp1) in the prevention of oxidative stress-mediated cellular damage. To assess the effect of carbofuran on Nrf2 signalling, we established a dual-monitoring transgenic zebrafish line, expressing gstp1 promoter-driven EGFP and mCherry-tagged Neh2 domain of Nrf2. Our results suggested that the exposure of carbofuran has down-regulated both Nrf2 and Gstp1 expressions. Overall, carbofuran affects cellular autophagy and accelerates senescence by enervating the Nrf2 signalling.