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At least 1,549 records · Page 86

Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates

Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interaction between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. Furthermore, we applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.

3-D printing↗

Bump-and-Hole Engineering Identifies Specific Substrates of Glycosyltransferases in Living Cells

Studying posttranslational modifications classically relies on experimental strategies that oversimplify the complex biosynthetic machineries of living cells. Protein glycosylation contributes to essential biological processes, but correlating glycan structure, underlying protein, and disease-relevant biosynthetic regulation is currently elusive. Here, we engineer living cells to tag glycans with editable chemical functionalities while providing information on biosynthesis, physiological context, and glycan fine structure. We introduce a non-natural substrate biosynthetic pathway and use engineered glycosyltransferases to incorporate chemically tagged sugars into the cell surface glycome of the living cell. We apply the strategy to a particularly redundant yet disease-relevant human glycosyltransferase family, the polypeptide N-acetylgalactosaminyl transferases. This approach bestows a gain-of-chemical-functionality modification on cells, where the products of individual glycosyltransferases can be selectively characterized or manipulated to understand glycan contribution to major physiological processes.

59 BASIC BIOLOGICAL SCIENCES↗

Acute wood smoke exposure is associated with cell-specific hippocampal transcriptomic responses in an accelerated ovarian failure mouse model

Background Wildfire events are increasing in frequency and intensity, and aging individuals demonstrate heightened biological susceptibility to air pollution exposures including increased risk of neurological sequelae. Declining ovarian hormones levels that occur with aging in females along with associated systemic physiological and inflammatory changes may contribute to increased cerebral vulnerability to air pollution, representing a potential but underexplored mechanism. Menopause and the menopausal transition represent a period of profound physiological change that affects cardiovascular, neurological, and immune health. Methods We tested whether peri-menopausal–like hormonal status amplifies hippocampal responses to acute wood smoke (WS) using an ovary-intact, 4-vinylcyclohexene diepoxide (VCD) model of moderate accelerated ovarian failure (AOF) in female C57BL/6 mice. Animals were exposed to HEPA-filtered air (FA) or WS for 4 h/day over 2 consecutive days (∼0.5 mg/m³). Exposure characterization confirmed a complex mixture of combustion products with significant levels of both trace metals and gas release during WS exposure. Results Spatial transcriptomics (10x Visium; n = 4 sections/group) with automated cell-type annotation identified astrocytes, GABAergic and glutamatergic neurons, oligodendrocytes, revealed cell type-specific transcriptional alterations following WS exposure. Distinct transcriptional patterns were observed across all identified neuronal and glial cell populations. Conclusion Together, these findings define a cell-type specific transcriptomic framework describing how WS exposure and ovarian hormone decline interact to influence hippocampal responses and identify potential cellular pathways relevant to hippocampal vulnerability.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

Introducing furanocoumarin biosynthetic genes in tomato results in coumarins accumulation and impacts growth

Over the past three decades, efforts to decipher plant metabolism have shed light on key enzymes driving specialized metabolite biosynthesis. Although only few pathways have been completely investigated to date, their characterization paves the way for exploring the potential effects of specialized metabolites on plant physiology. Among them is the linear furanocoumarin pathway, which was recently completed to produce up to psoralen. In this study, we report the first metabolic engineering of the linear furanocoumarin pathway to enable artificial psoralen production in tomato, through the integration of four genes coding for the enzymes: Umbelliferone Synthase (PsDiox), Demethylsuberosin Synthase (PsPT1), Marmesin Synthase (FcCYP76F112) and Psoralen Synthase (PsCYP71AJ3). Metabolic analyses confirmed the detection of small quantities of psoralen in the transgenic tomato line, but also highlighted a larger accumulation of coumarins and particularly scopoletin. Using morphophysiological and multi-omics analyses, we explorate how such metabolic modifications, could impact growth and affect plant physiology.

coumarins↗

Influence of fertilization on the dynamics of energy use in wheat

Plant energy use is fundamental to plant survival and growth. However, we still lack effective means to quantify plant energy use strategies. This study introduced a concept quantifying the light level at which photochemical and non-photochemical energy use in plants are in equilibrium — the photochemical compensation point (PCCP) which can be determined with chlorophyll fluorescence measurements. We used winter wheat as a test case to explore the dynamics of PCCP and its physiological and biochemical regulations. Winter wheat PCCP decreased significantly across growth stages from jointing to grain filling. Long-term nitrogen and phosphate (NP) fertilization significantly increased PCCP, whereas potassium (K) and manure (M) fertilizer supplementation had negligible effects. PCCP exhibited significant positive correlations with leaf thickness, leaf P and sulfur (S), and stomatal conductance (gs) across all growth stages. All manure-amended treatments exhibited positive correlations of PCCP with leaf N, P, K and gs, and negative correlations with leaf calcium (Ca). Random forest analysis revealed that gs was the most significant predictor of PCCP variation, followed by leaf P, iWUE, and leaf thickness across all treatments. We suggest that plant energy use strategies are strongly coupled with plant water use strategies and nutrient availability through a complex interplay of effects on physiological and biochemical traits.

energy allocation↗

Engineering a biopolymer for vascular embolization based on fundamental polymer principals

Herein we describe the engineering of a potential polymer substitute to metal coils for achieving vascular embolization. Our system is based on a methacrylate end-functionalized polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymer which displays thermal-reversible gelation properties and FCC ordering of the original copolymer while also being able to chemically crosslink. This system shows injectability, two-step gelation, chemical crosslinking with a five-fold increase in modulus and is highly resistant to washout under physiological flow conditions. Furthermore, we show that exposure to aqueous flow imparts resistance to swelling where less than 10 % swelling was observed under physiological flow as opposed to more than 60 % under static conditions after 30 days. Auxiliary experiments with PEO-PPO-PEO copolymers of various molecular weights indicate that this phenomenon may possibly be attributed to entanglements known to occur between adjacent micelles, where the reptation time, the time for polymer disentanglement, is long compared to the flow rate.

36 MATERIALS SCIENCE↗

NASA's surface biology and geology designated observable: A perspective on surface imaging algorithms

The 2017-2027 National Academies' Decadal Survey, Thriving on Our Changing Planet, recommended Surface Biology and Geology (SBG) as a "Designated Targeted Observable" (DO). The SBG DO is based on the need for capabilities to acquire global, high spatial resolution, visible to shortwave infrared (VSWIR; 380 - 2500 nm; ~30 m pixel resolution) hyperspectral (imaging spectroscopy) and multispectral midwave and thermal infrared (MWIR: 3-5 µm; TIR: 8-12 µm; ~60 m pixel resolution) measurements with sub-monthly temporal revisits over terrestrial, freshwater, and coastal marine habitats. To address the various mission design needs, an SBG Algorithms Working Group of multidisciplinary researchers has been formed to review and evaluate the algorithms applicable to the SBG DO across a wide range of Earth science disciplines, including terrestrial and aquatic ecology, atmospheric science, geology, and hydrology. Here, we summarize current state-of-the-practice VSWIR and TIR algorithms that use airborne or orbital spectral imaging observations to address the SBG DO priorities identified by the Decadal Survey: (i) terrestrial vegetation physiology, functional traits, and health; (ii) inland and coastal aquatic ecosystems physiology, functional traits, and health; (iii) snow and ice accumulation, melting, and albedo; (iv) active surface composition (eruptions, landslides, evolving landscapes, hazard risks); (v) effects of changing land use on surface energy, water, momentum, and carbon fluxes; and (vi) managing agriculture, natural habitats, water use/quality, and urban development. We review existing algorithms in the following categories: snow/ice, aquatic environments, geology, and terrestrial vegetation, and summarize the community-state-of-practice in each category. Finally, this effort synthesizes the findings of more than 130 scientists.

54 ENVIRONMENTAL SCIENCES↗

A disposable bulk-acoustic-wave microalga trapping device for real-time water monitoring

Recently, there has been an increase in the use of algal physiology as a convenient and useful indicator for monitoring of water quality in aquatic ecosystems. However, current methods for monitoring algal physiology are high-cost, power intensive, and have limited sensitivity for practical samples in which algal concentration is low. In order to alleviate these problems, we developed a simple-to-fabricate acoustophoretic particle trapping device that can effectively enrich various types of microalgae such as chlorella and diatoms for real-time monitoring of water quality. This microalgae trap is fabricated by embedding a piezoelectric resonator in a single channel. In comparison to previously reported acoustophoretic particle traps, this device has a simple structure and does not require sheath flows, which makes the device low cost and simple to fabricate and operate. Using Chlorella kessleri and the marine diatom Thalassiosira pseudonana as model algae, we report the microalgae trap has demonstrated notable particle trapping efficiencies between 82 % to 74 % for Chlorella with a through-flow of 0.5 μl/min to 2.7 μl/min and 85 % to 79 % for diatoms with a 0.5 μl/min to 4 μl/min through-flow. The trap has also shown to simultaneously trap Chlorella and diatoms at different heights of the microchannel. This device has high promise for trapping, separating and manipulating microalgae.

47 OTHER INSTRUMENTATION↗

Soil microbial CNP and respiration responses to organic matter and nutrient additions: Evidence from a tropical soil incubation

Soil nutrient availability has a strong influence on the fate of soil carbon (C) during microbial decomposition, contributing to Earth's C balance. While nutrient availability itself can impact microbial physiology and C partitioning between biomass and respiration during soil organic matter decomposition, the availability of labile C inputs may mediate the response of microorganisms to nutrient additions. As soil organic matter is decomposed, microorganisms retain or release C, nitrogen (N) or phosphorus (P) to maintain a stoichiometric balance. While the concept of a microbial stoichiometric homeostasis has previously been proposed, microbial biomass CNP ratios are not static, and this may have very relevant implications for microbial physiological activities. In this work, we tested the hypothesis that N, P and potassium (K) nutrient additions impact C cycling in a tropical soil due to microbial stoichiometric constraints to growth and respiration, and that the availability of energy-rich labile organic matter in the soil (i.e. leaf litter) mediates the response to nutrient addition. We incubated tropical soil from French Guiana with a 13 C labeled leaf litter addition and with mineral nutrient additions of +K, +N, +NK, +PK and +NPK for 30 days. We found that litter additions led to a ten-fold increase in microbial respiration and a doubling of microbial biomass C, along with greater microbial N and P content. We found some evidence that P additions increased soil CO 2 fluxes. Additionally, we found microbial biomass CP and NP ratios varied more widely than CN in response to nutrient and organic matter additions, with important implications for the role of microorganisms in C cycling. The addition of litter did not prime soil organic matter decomposition, except in combination with +NK fertilization, indicating possible P-mining of soil organic matter in this P-poor tropical soil. Together, these results point toward an ultimate labile organic substrate limitation of soil microorganisms in this tropical soil, but also indicate a complex interaction between C, N, P and K availability. This draws attention to the difference between microbial C cycling responses to N, P, or K additions in the tropics and explains why coupled C, N and P cycle modeling efforts cannot rely on strict microbial stoichiometric homeostasis as an underlying assumption.

13C↗

Resolving dynamic mineral-organic interactions in the rhizosphere by combining in-situ microsensors with plant-soil reactive transport modeling

Associations between minerals and organic matter represent one of the most important carbon storage mechanisms in soils. Plant roots are major sources of soil carbon, and resolving the dynamics and dominance of microbial consumption versus mineral sorption of root-derived carbon is critical to understanding soil carbon storage. Here we integrate in-situ rhizosphere microsensor and plant physiological measurements with a 3-D plant-soil reactive transport model to explore the fate of dissolved organic carbon (DOC) in the rhizosphere, particularly its microbial consumption and interaction with Fe oxide minerals. Over several days, a microdialysis probe sampling pore water at the root-soil interface of growing Vicia faba roots in live soil, revealed clear diel patterns of DOC concentration. Daytime DOC spikes coincided with peaks in leaf-level photosynthesis rates and were accompanied by declining redox potential and dissolved oxygen as well as increasing pH in the rhizosphere. Incorporating microsensor data into our modeling framework showed that the measured rapid loss of DOC after each mid-day spike could not be explained by consumption via aerobic respiration, nor via anaerobic respiration dominated by Fe oxide reduction. Rather, in the model, a large fraction of rhizosphere DOC was rapidly immobilized each day by adsorption to Fe oxides. Further, modeled microbial Fe reduction (fueled by DOC) did not mobilize significant organic carbon from Fe oxides during the day. Instead, the model predicted equilibrium desorption of organic carbon from Fe oxides at night. This new mechanistic modeling framework, which couples aboveground plant physiological measurements with non-destructive high-resolution monitoring of rhizosphere processes, has great potential for exploring the dynamics and balance of the various microbial reactions and mineral interactions controlling carbon transformations and storage in soils.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Effects of the UV filter benzophenone-3 (oxybenzone) at low concentrations in zebrafish (Danio rerio)

Organic UV filters including benzophenone-3 (BP-3) are widely used to protect humans and materials from damage by UV irradiation. Despite the environmental occurrence of BP-3 in the aquatic environment, little is known about its effects and modes of action. In the present study we assess molecular and physiological effects of BP-3 in adult male zebrafish (Danio rerio) and in eleuthero-embryos by a targeted gene expression approach focusing on the sex hormone system. Fish and embryos are exposed for 14 days and 120 hours post fertilization, respectively, to 2.4–312 μg/L and 8.2–438 μg/L BP-3. Chemical analysis of water and fish demonstrates that BP-3 is partly transformed to benzophenone-1 (BP-1) and both compounds are accumulated in adult fish. Biotransformation to BP-1 is absent in eleuthero-embryos. BP-3 exposure leads to similar alterations of gene expression in both adult fish and eleuthero-embryos. In the brain of adult males esr1, ar and cyp19b are down-regulated at 84 μg/L BP-3. There is no induction of vitellogenin expression by BP-3, both at the transcriptional and protein level. An overall down-regulation of the hsd3b, hsd17b3, hsd11b2 and cyp11b2 transcripts is observed in the testes, suggesting an antiandrogenic activity. No histological changes were observed in the testes after BP-3 treatment. The study leads to the conclusion that low concentrations of BP-3 exhibit similar multiple hormonal activities at the transcription level in two different life stages of zebrafish. Forthcoming studies should show whether this translates to additional physiological effects. Highlights: ► Activity of UV filter benzophenone-3 (BP-3) is assessed in zebrafish. ► BP-3 is partly metabolized to benzophenone-1 by adult fish but not embryos. ► Alterations of gene expression are similar in adult males and embryos. ► Gene expression alterations point to multiple hormonal activity of BP-3.

60 APPLIED LIFE SCIENCES↗

Superparamagnetic iron oxide polyacrylic acid coated γ-Fe{sub 2}O{sub 3} nanoparticles do not affect kidney function but cause acute effect on the cardiovascular function in healthy mice

This study describes the distribution of intravenously injected polyacrylic acid (PAA) coated γ-Fe{sub 2}O{sub 3} NPs (10 mg kg{sup −1}) at the organ, cellular and subcellular levels in healthy BALB/cJ mice and in parallel addresses the effects of NP injection on kidney function, blood pressure and vascular contractility. Magnetic resonance imaging (MRI) and transmission electron microscopy (TEM) showed accumulation of NPs in the liver within 1 h after intravenous infusion, accommodated by intracellular uptake in endothelial and Kupffer cells with subsequent intracellular uptake in renal cells, particularly the cytoplasm of the proximal tubule, in podocytes and mesangial cells. The renofunctional effects of NPs were evaluated by arterial acid–base status and measurements of glomerular filtration rate (GFR) after instrumentation with chronically indwelling catheters. Arterial pH was 7.46 ± 0.02 and 7.41 ± 0.02 in mice 0.5 h after injections of saline or NP, and did not change over the next 12 h. In addition, the injections of NP did not affect arterial PCO{sub 2} or [HCO{sub 3}{sup −}] either. Twenty-four and 96 h after NP injections, the GFR averaged 0.35 ± 0.04 and 0.35 ± 0.01 ml min{sup −1} g{sup −1}, respectively, values which were statistically comparable with controls (0.29 ± 0.02 and 0.33 ± 0.1 ml{sup –1} min{sup –1} 25 g{sup –1}). Mean arterial blood pressure (MAP) decreased 12–24 h after NP injections (111.1 ± 11.5 vs 123.0 ± 6.1 min{sup −1}) associated with a decreased contractility of small mesenteric arteries revealed by myography to characterize endothelial function. In conclusion, our study demonstrates that accumulation of superparamagnetic iron oxide nanoparticles does not affect kidney function in healthy mice but temporarily decreases blood pressure. -- Highlights: ► PAA coated γ-Fe{sub 2}O{sub 3} nanoparticles were injected intravenously into healthy mice. ► We examine the distribution and physiological effects of nanoparticle accumulation. ► No effects of accumulation in kidney on acid-base status or GFR. ► Acute hypotension associated with decreased contractility of small vessels. ► We demonstrate physiological effects of PAA γ-Fe{sub 2}O{sub 3} NP for medical purposes.

60 APPLIED LIFE SCIENCES↗

Toxicodynamics of rigid polystyrene microparticles on pulmonary gas exchange in mice: Implications for microemboli-based drug delivery systems

The toxicodynamic relationship between the number and size of pulmonary microemboli resulting from uniformly sized, rigid polystyrene microparticles (MPs) administered intravenously and their potential effects on pulmonary gas exchange were investigated. CD-1 male mice (6–8 weeks) were intravenously administered 10, 25 and 45 μm diameter MPs. Oxygen hemoglobin saturation in the blood (SpO{sub 2}) was measured non-invasively using a pulse oximeter while varying inhaled oxygen concentration (F{sub I}O{sub 2}). The resulting data were fit to a physiologically based non-linear mathematical model that estimates 2 parameters: ventilation–perfusion ratio (V{sub A}/Q) and shunt (percentage of deoxygenated blood returning to systemic circulation). The number of MPs administered prior to a statistically significant reduction in normalized V{sub A}/Q was dependent on particle size. MP doses that resulted in a significant reduction in normalized V{sub A}/Q one day post-treatment were 4000, 40,000 and 550,000 MPs/g for 45, 25 and 10 μm MPs, respectively. The model estimated V{sub A}/Q and shunt returned to baseline levels 7 days post-treatment. Measuring SpO{sub 2} alone was not sufficient to observe changes in gas exchange; however, when combined with model-derived V{sub A}/Q and shunt early reversible toxicity from pulmonary microemboli was detected suggesting that the model and physical measurements are both required for assessing toxicity. Moreover, it appears that the MP load required to alter gas exchange in a mouse prior to lethality is significantly higher than the anticipated required MP dose for effective drug delivery. Overall, the current results indicate that the microemboli-based approach for targeted pulmonary drug delivery is potentially safe and should be further explored. -- Highlights: ► Murine pulmonary gas exchange after microembolization was non-invasively studied. ► A physiologically based model quantified impairment of pulmonary gas exchange. ► Number and size of microemboli determine severity of impaired gas exchange. ► Pulmonary gas exchange returns to baseline within 7 days.

60 APPLIED LIFE SCIENCES↗

Safflor yellow B suppresses angiotensin II-mediated human umbilical vein cell injury via regulation of Bcl-2/p22{sup phox} expression

Intracellular reactive oxygen species (ROS) are derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Angiotensin II (Ang II) can cause endothelial dysfunction by promoting intracellular ROS generation. Safflor yellow B (SYB) effectively inhibits ROS generation by upregulating Bcl-2 expression. In this study, we examined the effects of SYB on Ang II-induced injury to human umbilical vein endothelial cells (HUVECs), and elucidated the roles of NADPH oxidase and Bcl-2. We treated cultured HUVECs with Ang II, SYB, and Bcl-2 siRNA, and determined NADPH oxidase activity and ROS levels. Furthermore, cellular and mitochondrial physiological states were evaluated, and the expression levels of target proteins were analyzed. Ang II significantly enhanced intracellular ROS levels, caused mitochondrial membrane dysfunction, and decreased cell viability, leading to apoptosis. This was associated with increased expression of AT1R and p22{sup phox}, increased NADPH oxidase activity, and an increased ratio of Bax/Bcl-2, leading to decreases in antioxidant enzyme activities, which were further strengthened after blocking Bcl-2. Compared to Ang II treatment alone, co-treatment with SYB significantly reversed HUVEC injury. Taken together, these results demonstrate that SYB could significantly protect endothelial cells from Ang II-induced cell damage, and that it does so by upregulating Bcl-2 expression and inhibiting ROS generation. - Highlights: • Angiotensin II depresses mitochondria physiological function. • Angiotensin II activates NADPH oxidase via up-regulating expresion of p22{sup phox}. • Bcl-2 plays a pivotal role in improving mitochondria function and regulates ROS level. • Inhibitor of Bcl-2 promotes angiotensin II mediated HUVEC injury. • SYB attenuates angiotensin II mediated HUVEC injury via up regulating Bcl-2 expression.

60 APPLIED LIFE SCIENCES↗

Assessment of beating parameters in human induced pluripotent stem cells enables quantitative in vitro screening for cardiotoxicity

Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes show promise for screening during early drug development. Here, we tested a hypothesis that in vitro assessment of multiple cardiomyocyte physiological parameters enables predictive and mechanistically-interpretable evaluation of cardiotoxicity in a high-throughput format. Human iPSC-derived cardiomyocytes were exposed for 30 min or 24 h to 131 drugs, positive (107) and negative (24) for in vivo cardiotoxicity, in up to 6 concentrations (3 nM to 30 uM) in 384-well plates. Fast kinetic imaging was used to monitor changes in cardiomyocyte function using intracellular Ca{sup 2+} flux readouts synchronous with beating, and cell viability. A number of physiological parameters of cardiomyocyte beating, such as beat rate, peak shape (amplitude, width, raise, decay, etc.) and regularity were collected using automated data analysis. Concentration–response profiles were evaluated using logistic modeling to derive a benchmark concentration (BMC) point-of-departure value, based on one standard deviation departure from the estimated baseline in vehicle (0.3% dimethyl sulfoxide)-treated cells. BMC values were used for cardiotoxicity classification and ranking of compounds. Beat rate and several peak shape parameters were found to be good predictors, while cell viability had poor classification accuracy. In addition, we applied the Toxicological Prioritization Index (ToxPi) approach to integrate and display data across many collected parameters, to derive “cardiosafety” ranking of tested compounds. Multi-parameter screening of beating profiles allows for cardiotoxicity risk assessment and identification of specific patterns defining mechanism-specific effects. These data and analysis methods may be used widely for compound screening and early safety evaluation in drug development. - Highlights: • Induced pluripotent stem cell-derived cardiomyocytes are promising in vitro models. • We tested if evaluation of cardiotoxicity is possible in a high-throughput format. • The assay shows benefits of automated data integration across multiple parameters. • Quantitative assessment of concentration–response is possible using iPSCs. • Multi-parametric screening allows for cardiotoxicity risk assessment.

60 APPLIED LIFE SCIENCES↗

Adverse testicular effects of Botox® in mature rats

Botox® injections are taking a consistently increasing place in urology. Intracremasteric injections, particularly, have been applied for cryptorchidism and painful testicular spasms. Studies outlining their safety for this use are, however, scanty. Thus, the present study aimed at evaluating possible testicular toxicity of Botox® injections and their effect on male fertility. Mature rats were given intracremasteric Botox® injections (10, 20 and 40 U/kg) three times in a two-week interval. Changes in body and testes weights were examined and gonadosomatic index compared to control group. Semen quality, sperm parameters, fructose, protein, cholesterol and triglycerides contents were assessed. Effects on normal testicular function were investigated by measuring testosterone levels and changes in enzyme activities (lactate dehydrogenase-X and acid phosphatase). To draw a complete picture, changes in oxidative and inflammatory states were examined, in addition to the extent of connective tissue deposition between seminiferous tubules. In an attempt to have more accurate information about possible spermatotoxic effects of Botox®, flowcytometric analysis and histopathological examination were carried out. Botox®-injected rats showed altered testicular physiology and function. Seminiferous tubules were separated by dense fibers, especially with the highest dose. Flowcytometric analysis showed a decrease in mature sperms and histopathology confirmed the findings. The oxidative state was, however, comparable to control group. This study is the first to show that intracremasteric injections of Botox® induce adverse testicular effects evidenced by inhibited spermatogenesis and initiation of histopathological changes. In conclusion, decreased fertility may be a serious problem Botox® injections could cause. - Highlights: • Botox® injections are the trend nowadays, for both medical and non-medical uses. • They were recently suggested for cryptorchidism and testicular spasms. • This study outlines possible testicular adverse effects of these injections. • Botox® affected normal testicular function and physiology. • Infertility is a serious problem that Botox® injections could cause.

60 APPLIED LIFE SCIENCES↗

Effect of the combination of metformin hydrochloride and melatonin on oxidative stress before and during pregnancy, and biochemical and histopathological analysis of the livers of rats after treatment for polycystic ovary syndrome

The aim of the present study was to analyze the effect of a combination of metformin hydrochloride and melatonin on oxidative stress together with a biochemical and histopathological analysis of the livers of Wistar rats induced with PCOS. The results indicated that a combination of the drugs was more effective in the reduction of plasmatic levels of liver enzyme alanine aminotransferase, nitric oxide and total glutathione, and decreased the inflammatory response and histopathological damage, producing results that were significantly similar to animals from the control group. A mixture of the drugs produced more effective results against liver toxicity caused by PCOS, encouraging the normalization of biochemical parameters. During pregnancy, there was reduced oxidative stress compared to monotherapeutic use of these drugs. Interestingly, the combination of the drugs caused a physiological reaction similar to responses identified in healthy rats without induction of the PCOS control group. However, the clinical and physiological effectiveness of the combination should be further explored, especially with respect to the possible side effects on offspring. - Highlights: • Studies have documented increased oxidative stress in patients with PCOS. • It has been noted that women with PCOS have a high prevalence of liver alterations. • Liver disease in pregnancy may be pre-existing increasing the newborn mortality. • Metformin/melatonin associated reduced oxidative stress in liver in pregnant rats. • Association of metformin/melatonin normalizes hepatic biochemical parameters.

60 APPLIED LIFE SCIENCES↗

Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors

Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28 °C as compared to 37 °C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology. - Highlights: • Zebrafish is increasingly used to study the effects of estrogens. • We assessed the activity of pharmaceutical and environmental estrogens on zfERs. • Environmental estrogens displayed greater potency for zfERα compared to zfERβs. • hERβ selective agonists displayed greater potency for zfERα compared to zfERβs. • The hERα selective agonist 16αL-E2 is the most zfERα selective compound.

60 APPLIED LIFE SCIENCES↗