Biology subjects

de Almeida Monteiro Melo Ferraz, M.

Publications and source records attributed to de Almeida Monteiro Melo Ferraz, M..

5 recordsLinked to original sources

bioRxiv2023

Microplastics are detected in bull and dog sperm and polystyrene microparticles impair sperm fertilization

The alarming increase in global infertility rates has coincided with the pervasive accumulation of microplastics (MPs) resulting from the poor management of plastic waste. This concerning trend is particularly troubling because only 10% of male infertility cases can be attributed to identifiable causes, leaving a significant knowledge gap in our understanding of their underlying factors. To bridge this critical gap, it is important to explore the connection between the accumulation of MPs and the observed decline in male fertility. Here, the presence of microplastics in reproductive fluids from bulls and dogs was assessed and used as baseline concentrations for bull sperm exposure. Bovine epididymal sperm (ES) presented a mean of 72.5 MP particles mL-1 (0.3691 g mL-1) while canine seminal plasma had an average of 35.4 MP particles mL-1 (0.0066 g mL-1). Bovine sperm was exposed to three different concentrations of a mixture of 1.1, 0.5, and 0.3 {micro}m polystyrene (PS) beads: (1) 0.7 g mL-1, blood concentration of PS in cows (bPS); (2) 0.37 g mL-1, concentration of total MPs in ES (esMP); and (3) 0.026 g mL-1, concentration of PS in ES (esPS). All sperm samples incubated with PS exhibited reduced motility compared with the CT at 0.5 h. However, PS exposure did not affect acrosome or induced oxidative stress. When used for in vitro fertilization, the sperm exposed to PS had decreased blastocyst rates, in addition to inducing ROS formation and apoptosis on resulting embryos. By employing realistic exposure concentrations, this research sought to shed light on the comprehensive impact of MPs on bovine sperm and the quality of resulting embryos, providing the first evidence of MPs in bovine and dog sperm and demonstrating the detrimental effect of PS MPs on sperm motility and functionality. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/571802v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@5871acorg.highwire.dtl.DTLVardef@8ee9f2org.highwire.dtl.DTLVardef@a1416borg.highwire.dtl.DTLVardef@cde261_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIMicroplastics were found across the most diverse range of environments and their presence have been shown to affect reproductive parameters within different species. C_LIO_LITrue-to-life concentrations of exposure were used to assess the potential effects of polystyrene in sperm parameters and fertilization. C_LIO_LIPolystyrene microplastics attach to sperm and decrease motility, also reducing sperm functionality as seen by decreased blastocyst rate and increased oxidative stress in embryos. C_LI

developmental biology↗

bioRxiv2023

Microplastics analytics: why we should not underestimate the importance of blank controls

Recent years have seen considerable scientific attention devoted towards documenting the presence of microplastics (MPs) in environmental samples. Due to omnipresence of environmental microplastics, however, disentangling environmental MPs from sample contamination is a challenge. Hence, the environmental (collection site and laboratory) microplastics contamination of samples during processing is a reality that we must address, in order to generate reproducible and reliable data. Here we investigated published literature and have found that around 1/5 of studies failed to use blank controls in their experiments. Additionally, only 34% of the studies used a controlled air environment for their samples processing (laminar flow, fume hood, closed laboratory, clean room, etc.). In that regard, we have also shown that preparing samples in the fume hood, leads to more microplastics contamination than preparing it in the laboratory bench and the laminar flow. Although it did not completely prevent microplastics contamination, the processing of sample inside the laminar flow is the best option to reduce sample contamination during processing. Overall, we showed that blank controls are a must in microplastics sample preparation, but it is often overlooked by researchers. HighlightsO_LIMost of the contaminant microplastics in blank controls were particles < 20 m. C_LIO_LIFume hoods result in more contamination than processing the samples on the bench. C_LIO_LILaminar flow was the best option for reducing MPs contamination of samples. C_LIO_LI1/5 of studies failed to use blank controls, and 1/3 did not correct their data. C_LIO_LIImproving the use and description of blanks is imperative for ensuring data quality. C_LI Mandatory graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/527118v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1de1ef4org.highwire.dtl.DTLVardef@1c240cdorg.highwire.dtl.DTLVardef@2c57bcorg.highwire.dtl.DTLVardef@1341059_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2022

The need for ecologically realistic studies on the health effects of microplastics

Plastic pollution is now so widespread that microplastics are consistently detected in every biological sample surveyed for their presence. Despite their pervasiveness, very little is known about the effects of microplastics on the health of terrestrial species. While emerging studies are showing that microplastics represent a potentially serious threat to animal health, data have been limited to in vivo studies on laboratory rodents that were force fed plastics. The extent to which these studies are representative of the conditions that animals and humans might actually experience in the real world is largely unknown. Here, we review the peer-reviewed literature in order to understand how the concentrations and types of microplastics being administered in lab studies compare to those found in terrestrial soils. We found that lab studies have heretofore fed rodents microplastics at concentrations that were hundreds of thousands of times greater than they would be exposed to in nature. Furthermore, health effects have been studied for only 10% of the microplastic polymers that are known to occur in soils. The plastic pollution crisis is arguably one of the most pressing ecological and public health issues of our time, yet existing lab-based research on the health effects of terrestrial microplastics does not reflect the conditions that free-ranging animals are actually experiencing. Going forward, performing more true-to-life research will be of the utmost importance to understand the impacts of microplastics and maintain the publics faith in the scientific process.

pharmacology and toxicology↗

bioRxiv2022

Microplastics are present in follicular fluid and compromise gamete function in vitro: Is the Anthropocene throw-away society throwing away fertility?

The past several decades have seen alarming declines in the reproductive health of humans, animals and plants. While humans have introduced numerous pollutants that can impair reproductive systems (such as well-documented endocrine disruptors), the potential for microplastics (MPs) to be contributing to the widespread declines in fertility is particularly noteworthy. Over the same timespan that declines in fertility began to be documented, there has been a correlated shift towards a "throw-away society" that is characterised by the excessive consumption of single-use plastic products and a concomitant accumulation of MPs pollution. Studies are showing that MPs can impair fertility, but data have been limited to rodents that were force-fed hundreds of thousands of times more plastics than they would be exposed in the environment. As a first step to link in vitro health effects with in vivo environmental exposure, we quantified microplastics in the follicular fluid of women and domestic cows. We found that the concentrations of polystyrene microplastics that naturally occurred in follicular fluid were sufficient to compromise the maturation of bovine oocytes in vitro. Collectively, these findings demonstrate that microplastics may also be contributing to the widespread declines in fertility that have been occurring over recent Anthropocene decades.

developmental biology↗

bioRxiv2021

RNAseq analysis reveals dynamic metaboloepigenetic profiles of human, mouse and bovine pre-implantation embryos

Metaboloepigenetic regulation (metabolites regulating the cellular epigenome inducing long-term changes), has been reported in stem cells, germ cells and tumor cells. Embryonic metaboloepigenetics, however, have just begun to be described. Here we analyzed RNAseq data to characterize the metaboloepigenetic profiles of human, mouse and bovine pre-implantation embryos. In embryos, metaboloepigenetic reprogramming is species specific, varies with the developmental stage and is disrupted with in vitro culture. Although the idea that the in vitro environment may influence embryo development is not new, there has been little progress on improving pregnancy rates after more than 43 years using in vitro fertilization. Hence, the present data on embryonic metaboloepigenetic will contribute to understanding how the in vitro manipulation affects the metaboloepigenetic status of early embryos, which can be used to establish culture strategies aimed at improving the in vitro environment and, consequently, pregnancy rates and offspring health.

developmental biology↗