Tolerance of spermatogonia to oxidative stress is due to high levels of Zn and Cu/Zn superoxide dismutase

Effect of quercetin and mirtazapine on spermatogenesis and testis structure in phenylhydrazine-induced hemolytic anemia mice: An experimental study

Anemia poses a significant healthcare challenge across different socioeconomic groups and can result in reproductive system damage through the generation of free radicals and lipid peroxidation. This study examines the protective effects of quercetin (QUE) and mirtazapine (MIR) against the reproductive damage caused by phenylhydrazine (PHZ) in mice. Fifty NMRI mice, aged 8-10 weeks with an average weight of 27.0 ± 2.0 g, were randomly divided into five groups. The control group (Group 1) received oral administration of 10 mL/kg/day of normal saline. Group 2 (PHZ group) received an initial intraperitoneal dose of 8 mg/100 g body weight of PHZ, followed by subsequent doses of 6 mg/100 g every 48 h. Group 3 received PHZ along with oral QUE at a dosage of 50 mg/kg/day. Group 4 received PHZ along with oral MIR at a dosage of 30 mg/kg/day. Group 5 received PHZ along with oral QUE at a dosage of 50 mg/kg/day and MIR at a dosage of 30 mg/kg/day. The treatment duration was 35 days. Sperm samples were collected from the caudal region of the epididymis post-euthanasia to assess the total mean sperm count, sperm viability, motility, DNA damage, and morphology. Testicular tissue was employed to quantify total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) concentrations, while serum levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were analyzed. Additionally, various aspects, including testicular histopathology, oxidative enzyme levels, gene expression related to apoptosis and antiapoptotic pathways, and in vivo fertility index, were evaluated after 35 days. The QUE, MIR, and QUE + MIR groups showed less abnormal morphology and DNA damage, as well as better total and progressive sperm motility, motility characteristics, viability, and plasma membrane function compared to the PHZ group. QUE, MIR, and QUE + MIR administration increased TAC, SOD, and GPx activities in testicular tissue, while reducing MDA levels compared to the PHZ group. Furthermore, QUE, MIR, and QUE + MIR significantly reduced Bax, and caspase-3 expression levels, and increased Bcl-2 expression levels, compared to the PHZ group. Mice treated with QUE, MIR, and QUE + MIR exhibited an increased in vivo fertility index and plasma sex hormone levels compared to the PHZ group. These results show that QUE, MIR, and QUE + MIR might be able to improve the fertility index, boost the testicular antioxidant defense system, and control the death of germ cells. This could mean that they could be used to treat mice with PHZ-induced testicular damage.

Simulated climate change and atrazine contamination can synergistically impair zebrafish testicular function

Elements that interfere with reproductive processes can have profound impacts on population and the equilibrium of ecosystems. Global warming represents the major environmental challenge of the 21st century, as it will affect all forms of life in the coming decades. Another coexisting concern is the persistent pollution by pesticides, particularly the herbicide Atrazine (ATZ), which is responsible for a significant number of contamination incidents in surface waters worldwide. While it is hypothesized that climate changes will significantly enhance the toxic effects of pesticides, the actual impact of these phenomena remain largely unexplored. Here, we conducted a climate-controlled room experiment to assess the interactive effects of the projected 2100 climate scenario and environmentally realistic ATZ exposures on the reproductive function of male zebrafish. The gonadosomatic index significantly decreased in fish kept in the extreme scenario. Cellular alterations across spermatogenesis phases led to synergic decreased sperm production and increased germ cell sloughing and death. ATZ exposure alone or combined with climate change effects, disrupted the transcription levels of key genes involved in steroidogenesis, hormone signaling and spermatogenesis regulation. An additive modulation with decreased 11-KT production and increased E2 levels was also evidenced, intensifying the effects of androgen/estrogen imbalance. Moreover, climate change and ATZ independently induced oxidative stress, upregulation of proapoptotic gene and DNA damage in post-meiotic germ cell, but the negative effects of ATZ were greater at extreme scenario. Ultimately, exposure to simulated climate changes severely impaired fertilization capacity, due to a drastic reduction in sperm motility and/or viability. These findings indicate that the future climate conditions have the potential to considerably enhance the toxicity of ATZ at low concentrations, leading to significant deleterious consequences for fish reproductive function and fertility. These may provide relevant information to supporting healthcare and environmental managers in decision-making related to climate changes and herbicide regulation.

Enhancement of Frozen-Thawed Human Sperm Quality with Zinc as a Cryoprotective Additive

BACKGROUND Cryopreservation preserves male fertility, crucial in oncology, advanced age, and infertility. However, it damages sperm motility, membrane, and DNA. Zinc (Zn), an antioxidant, shows promise in improving sperm quality after thawing, highlighting its potential as a cryoprotectant in reproductive medicine. MATERIAL AND METHODS Gradient concentration of ZnSO₄ (0, 12.5, 25, 50, and 100 µM) was added in the Glycerol-egg yolk-citrate (GEYC) cryopreservative medium as an extender. Alterations in sperm viability and motility parameters after cryopreservation were detected in each group. Sperm plasma membrane integrity (PMI), acrosome integrity (ACR), DNA fragment index (DFI), and changes in sperm mitochondrial function were examined, including: mitochondrial potential (MMP), sperm reactive oxygen species (ROS), and sperm ATP. RESULTS We found that 50 µM ZnSO₄ was the most effective for the curvilinear velocity (VCL) and the average path velocity (VAP) of sperm after cryo-resuscitation. Compared to the Zn-free group, sperm plasma membrane integrity (PMI) was increased, DNA fragmentation index (DFI) was decreased, reactive oxygen species (ROS) was reduced, and mitochondrial membrane potential (MMP) was increased after cryorevival in the presence of 50 µM ZnSO₄. CONCLUSIONS Zn ion is one of the antioxidants in the cell. The results of our current clinical study are sufficient to demonstrate that Zn can improve preserves sperm quality during cryopreservation when added to GEYC. The addition of 50 µM ZnSO₄ increased curve velocity, mean path velocity, sperm survival (or plasma membrane integrity), and mitochondrial membrane potential while reducing ROS production and DNA breaks compared to GEYC thawed without ZnSO₄.

Trace and essential elements as vital components to improve the performance of the male reproductive system: Implications in cell signaling pathways

Successful male fertilization requires the main processes such as normal spermatogenesis, sperm capacitation, hyperactivation, and acrosome reaction. The progress of these processes depends on some endogenous and exogenous factors. So, the optimal level of ions and essential and rare elements such as selenium, zinc, copper, iron, manganese, calcium, and so on in various types of cells of the reproductive system could affect conception and male fertility rates. The function of trace elements in the male reproductive system could be exerted through some cellular and molecular processes, such as the management of active oxygen species, involvement in the action of membrane channels, regulation of enzyme activity, regulation of gene expression and hormone levels, and modulation of signaling cascades. In this review, we aim to summarize the available evidence on the role of trace elements in improving male reproductive performance. Also, special attention is paid to the cellular aspects and the involved molecular signaling cascades.

Superoxidase dismutases (SODs) in the European eel: Gene characterization, expression response to temperature combined with hormonal maturation and possible migratory implications

Superoxide dismutases (SODs) are antioxidant enzymes that protect cells from oxidation. Three SODs have been identified in mammals, but there is limited information in teleosts. This study investigates SODs in the European eel and their expression patterns during testis maturation. Phylogenetic and synteny analyses revealed SODs paralogs and their evolution in vertebrates. The eel possesses one SOD1 and two SOD2/3 (a and b), indicating SOD2 and SOD3 duplication in elopomorphs. SODs expression were then evaluated in various male and female tissues. SOD1 is more expressed in females, while SOD2a and SOD2b dominate brain-pituitary-gonad tissues in both sexes. SOD3a showed predominant expression in the ovary and the male livers, whereas SOD3b was found in the pituitary and brain of both sexes. The effects of different maturation protocols (standard hormonal treatment vs. same protocol preceded with cold seawater pre-treatment) on SODs expression during testis maturation were evaluated. Salinity increase at the onset of standard treatment at 20 °C, simulating early migration, upregulated SOD1, SOD2a, and SOD2b, coinciding with spermatogonia type A differentiated cells dominance. Thereafter, SOD2a and SOD3a decreased, while SOD2b increased during hormonal treatment-induced spermatogenesis. Pre-treatment with seawater at 10 °C, mimicking the conditions at the beginning of the seawater migration, downregulated SOD1 but increased SOD3a expression. Finally, the standard hormonal treatment, replicating spawning at higher temperatures, downregulated SOD1 in eels without any pre-treatment while SOD2a expression increased in pre-treated eels. This study revealed tissue-specific, sex-dependent, and maturation-related SOD expression patterns, predicting SODs dynamic expression profiles during their reproductive migration.

Progress on the roles of zinc in sperm cryopreservation

One of the effective methods for the long-term preservation of mammalian genetic resources is the cryopreservation of semen. However, a number of parameters, including diluents, the rate of freezing and thawing, cryoprotectants, etc., can easily alter the survival of frozen-thawed sperm. Numerous studies have documented the addition of a variety of zinc compounds, to the diluents used to cryopreserve sperm. The primary objective of this review is to briefly describe that adding zinc to diluents as an antioxidant significantly enhances frozen-thawed sperm quality. Second, a summary of the present understanding of zinc's molecular mechanism on semen cryopreservation is provided. Thirdly, this study addresses that nanoparticles of zinc can offer suggestions for raising cryopreservation effectiveness.

The Regulatory Effects of JAK2/STAT3 on Spermatogenesis and the Redox Keap1/Nrf2 Axis in an Animal Model of Testicular Ischemia Reperfusion Injury

The male reproductive system requires the pleiotropic activity of JAK/STAT to maintain its function, especially spermatogenesis. The study aims to investigate the effect of JAK2 signaling on the expression of the Keap1/Nrf2 axis, spermatogenesis, and the Sertoli cells (Sc) junctions in an animal model of testicular ischemia reperfusion injury (tIRI). Testes subjected to tIRI exhibited increased JAK2/STAT3 activity associated with spermatogenic arrest and reduced expression of the Sc junctions. In addition, there was an increased protein expression of Keap1 and decreased Nrf2., which was coupled with the downregulation of gene expression of antioxidant enzymes. Reduced SOD and CAT activities were accompanied by increased lipid peroxidation and protein carbonylation during tIRI. Increased caspase 9 activity and Bax/Bcl2 ratio indicated initiation of apoptosis. Inhibition of JAK2 activity by AG490 maintained the integrity of spermatogenesis and SC junctions, normalized the expression of the Keap1/Nrf2 axis and its downstream antioxidant enzymes, and prevented germ cell apoptosis. The results further emphasized the regulatory role of JAK2/STAT3 on spermatogenesis, Keap1/Nrf2 signaling, and maintenance of the testicular redox balance to combat testicular dysfunction and male infertility.

Post-thaw quality assessment of testicular fragments as a source of spermatogonial cells for surrogate production in the flatfish Solea senegalensis

Cryopreservation of germ cells would facilitate the availability of cells at any time allowing the selection of donors and maintaining quality control for further applications such as transplantation and germline recovery. In the present study, we analyzed the efficiency of four cryopreservation protocols applied either to isolated cell suspensions or to testes fragments from Senegalese sole. In testes fragments, the quality of cryopreserved germ cells was analyzed in vitro in terms of cell recovery, integrity and viability, DNA integrity (fragmentation and apoptosis), and lipid peroxidation (malondialdehyde levels). Transplantation of cryopreserved germ cells was performed to check the capacity of cells to in vivo incorporate into the gonadal primordium of Senegalese sole early larval stages (6 days after hatching (dah), pelagic live), during metamorphosis (10 dah) and at post-metamorphic stages (16 dah and 20 dah, benthonic life). Protocols incorporating dimethyl sulfoxide (DMSO) as a cryoprotectant showed higher number of recovered spermatogonia, especially in samples cryopreserved with L-15 + DMSO (0.39 ± 0.18 × 106 cells). Lipid peroxidation and DNA fragmentation were also significantly lower in this treatment compared with other treatments. An important increase in oxidation (MDA levels) was detected in samples containing glycerol as a cryoprotectant, reflected also in terms of DNA damage. Transplantation of L-15 + DMSO cryopreserved germ cells into larvae during early metamorphosis (10 dah, 5.2 mm) showed higher incorporation of cells (27.30 ± 5.27%) than other larval stages (lower than 11%). Cryopreservation of germ cells using testes fragments frozen with L-15 + DMSO was demonstrated to be a useful technique to store Senegalese sole germline.

Oxidative stress-induced apoptosis and autophagy: Balancing the contrary forces in spermatogenesis

Spermatogenesis is a complex process in the testis and is a cornerstone of male infertility. The abundance of unsaturated fatty acid and high cell division rate make male germs cells prone to DNA deterioration. ROS-mediated oxidative stress triggers DNA damage, autophagy, and apoptosis in male germ cells, which are critical causative factors that lead to male infertility. The complex connection and molecular crosstalk between apoptosis and autophagy is seen at multifaceted levels that interconnect the signaling pathways of these two processes. Multilevel interaction between apoptosis and autophagy is a seamless state of survival and death in response to various stressors. Interaction between multiple genes and proteins such as the mTor signaling pathway, Atg12 proteins, and the death adapter proteins, such as Beclin 1, p53, and Bcl-2 family proteins, validates such a link between these two phenomena. Testicular cells being epigenetically different from somatic cells, undergo numerous significant epigenetic transitions, and ROS modulates the epigenetic framework of mature sperm. Epigenetic deregulation of apoptosis and autophagy under oxidative stress conditions can cause sperm cell damage. The current review recapitulates the current role of prevailing stressors that generate oxidative stress leading to the induction of apoptosis and autophagy in the male reproductive system. Considering the pathophysiological consequences of ROS-mediated apoptosis and autophagy, a combinatorial approach, including apoptosis inhibition and autophagy activation, a therapeutic strategy to treat male idiopathic infertility. Understanding the crosslink between apoptosis and autophagy under stress conditions in male germ cells may play an essential role in developing therapeutic strategies to treat infertility.

Green Synthesized Zinc Oxide Nanoparticles Using Moringa olifera Ethanolic Extract Lessens Acrylamide-Induced Testicular Damage, Apoptosis, and Steroidogenesis-Related Gene Dysregulation in Adult Rats

This study assessed the possible protective role of green synthesized zinc oxide nanoparticles using Moringa olifera leaf extract (MO-ZNPs) in acrylamide (ACR)-induced reproductive dysfunctions in male rats. ACR (20 mg/kg b.wt/day) and/or MO-ZNPs (10 mg/kg b.wt/day) were given orally by gastric gavage for 60 days. Then, sperm parameters; testicular enzymes; oxidative stress markers; reproductive hormones including testosterone, luteinizing hormone (LH)-estradiol, and follicle-stimulating hormone (FSH) concentration; testis histology; steroidogenesis-related gene expression; and apoptotic markers were examined. The findings revealed that MO-ZNPs significantly ameliorated the ACR-induced decline in the gonadosomatic index and altered the pituitary-gonadal axis, reflected by decreased serum testosterone and FSH with increased estradiol and LH, and sperm analysis disruption. Furthermore, a notable restoration of the tissue content of antioxidants (catalase and reduced glutathione) but depletion of malondialdehyde was evident in MO-ZNPs+ACR-treated rats compared to ACR-exposed ones. In addition, MO-ZNPs oral dosing markedly rescued the histopathological changes and apoptotic caspase-3 reactions in the testis resulting from ACR exposure. Furthermore, in MO-ZNPs+ACR-treated rats, ACR-induced downregulation of testicular steroidogenesis genes and proliferating cell nuclear antigen (PCNA) immune-expression were reversed. Conclusively, MO-ZNPs protected male rats from ACR-induced reproductive toxicity by suppressing oxidative injury and apoptosis while boosting steroidogenesis and sex hormones.

Infection of Metarhizium anisopliae Ma6 and defense responses of host Phyllotreta striolata adults

Entomopathogenic fungus as biological control agent plays a crucial role in the integrated management of insect pests. Metarhizium anisopliae Ma6 has been identified as a highly pathogenic strain against Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae), one of the most economically important and dominant insect pests damaging Brassica plants. The infection of M. anisopliae Ma6 on P. striolata was observed under stereomicroscopy and scanning electron microscopy (SEM), and biochemical defense responses of P. striolata adults after infection were investigated. The changes in total amino acids and free fatty acids, and the activities of protective enzymes, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), in P. striolata adults were measured. In stereomicroscopy and SEM observations, a large number of mycelia were observed on the body surface of P. striolata on the 5th day after treatment by M. anisopliae. Many conidia were germinated and covered the body of P. striolata on the 7th day after treatment. The free fatty acid, total amino acid, CAT, POD, and SOD activities all showed an increased and then decreased trend. These results suggest that entomopathogenic fungal infection triggers the defense response of hosts, which induces changes in nutrients and antioxidant enzymes in P. striolata adults. Our findings provide useful information for understanding the potential for using M. anisopliae Ma6 as a biocontrol agent.

Protective role of melatonin against testicular damage caused by polymicrobial sepsis in adult rats

BACKGROUND

This study aimed to investigate the possible protective effects of melatonin (MEL) against the damage to testicular tissue in rats caused by polymicrobial sepsis as a result of cecal ligation and perforation (CLP).

METHODS

In this study, 21 male Wistar albino rats were used. The rats were randomly divided into three groups (n=7): Sham Control (Group 1), CLP (Group 2), and CLP + MEL (Group 3). Sepsis was created using the CLP method. MEL was administered intraperitoneally in two equal doses of 10 mg/kg at 30 min before and 6 h after perforation. Tissue sections taken from paraffin blocks were stained with hematoxylin and eosin (H and E) and examined histopathologically under a light microscope. Intracellular H2O2 and apoptosis evaluations were carried out using the flow cytometric method.

RESULTS

Sepsis caused a significant reduction in all sperm parameters. There was a significant decrease in sperm density, motility and cell numbers with normal morphology (p<0.05). Intracellular H2O2 level and apoptotic cell percentages increased in sperm cells in the CLP group. MEL treatment was found to significantly reduce sperm abnormalities, testicular damage, intracellular H2O2 levels, and apoptosis.

CONCLUSION

This study showed that melatonin administration could be a potential treatment option to reduce acute testicular tissue damage due to sepsis.

Analysis of antioxidants in water striders (Hemiptera: Gerridae) as bioindicator of water pollution

The antioxidant enzyme system is an important defense mechanism to cope with Reactive Oxygen Species (ROS) produced due to exposure to heavy metals. In the present study lead (Pb), chromium (Cr), arsenic (As), cadmium (Cd) and nickel (Ni) in water and the antioxidant activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was investigated in three species (Metrocoris communis, Limnogonus fossarum fossarum, and Aquarius adelaidis) of water striders collected from the industrial triangle of Punjab, Pakistan. The results of present study revealed that Pb, Cr, As, Cd and Ni were according to the permissible amount of WHO. The antioxidant activity of SOD, CAT and POD was found significantly different among species against oxidative stress, but found the highest activity of determining parameters in A. adelaidis. This is one of the pioneer studies in Pakistan reporting the role of water striders as a bioindicator of heavy metals present in the water through antioxidants enzyme variations. The current results supported that variant level of antioxidant enzyme activities in different species of water strider were reflective of heavy metal pollution in the Industrial triangle of Punjab, Pakistan and will be a useful ecotoxicological tools to evaluate the detrimental effects of heavy metal pollutants in aquatic organisms.

Effects of copper citrate on physiological-biochemical parameters of ejaculate of sire boars

Revealing peculiarities of the course of physiological and biochemical processes in the formation of parameters of ejaculate allows effective correlation of biological completeness of spermatozoids based on the use of chelate compounds of limiting microelements, particularly copper. The study was focused on determining changes in processes of spermatogenesis during correction of mineral nutrition. In the experiment, we used adult boars of the same age, live weight and quality of ejaculates. They consumed copper citrate during the 45 day experiment in doses higher than the norm by 10% (1.5 mg per 1 kg of combined feed) and 20% (3 mg per 1 kg of combined feed) compared with the control. We determined difference in the effects of different doses of copper citrate on the formation of parameters of ejaculates in sire boars. Addition of the mineral additive to the feed in the doses 10% exceeding the norm promoted increase in the parameters of functional activity of spermatozoids – mobility and survival – on day 45 of the intake, which occurred against the background of acceleration of peroxidation processes (increase in the concentration of thiobarbituric acid of active compounds) and activation of the system of antioxidant protection – increase in the activity of superoxide dismutase and decrease in the level of catalase in the sperm. At the same time, we observed increase in the morphometric parameters of spermatozoids – general length, width, length and volume of the head. On day 30, sire boars that had been consuming copper citrate in the amounts 20% above the norm were observed to have increase in concentration of spermatozoids, their mobility and survivability, though a decrease was seen in the morphometric parameters of the gametes. Further intake of this element caused increase in the amount of abnormal forms of spermatozoids. Under the action of this additive, we determined increase in the amount of metabolites of lipid peroxidation – conjugated dienes and thiobarbituric acids of active compounds, and also weakening of the system of antioxidative protection – decrease in the content of reduced glutathione and accumulation of dehydroascorbic acid. Thus, the intake of copper citrate in the amounts of 10% above the norm facilitated morpho-functional parameters of spermatozoids by activating the system of antioxidant protection. It would be promising to conduct further research to determine the effects of copper citrate on the processes of activation and capacitation of spermatozoids and fertilization of oocytes in in vivo and in vitro conditions.

Identification and Characterization of Antioxidant Enzyme Genes in Parasitoid Aphelinus asychis (Hymenoptera: Aphelinidae) and Expression Profiling Analysis under Temperature Stress

Simple Summary

High temperature affects the control efficiency of Aphelinus asychis, an important parasitic natural enemy of aphids. Antioxidative enzymes can protect organisms against oxidative damage by eliminating excess reactive oxygen species (ROS). This study identified 14 genes belonging to four classes of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), and glutathione-S-transferase (GST). The results showed that the expression levels and enzymatic activities of most antioxidant enzyme genes are significantly induced by high temperature, which indicates that antioxidant enzymes increase the resistance of A. asychis to lethal high temperature. Taken together, this study enriches the understanding of the molecular mechanisms of resistance of A. asychis to environmental high temperatures.

Abstract

It is well known that high temperature, a typically negative environmental factor, reduces the parasitism of a parasitoid. Generally, high temperature causes the rapid overproduction of reactive oxygen species (ROS) in organisms, and antioxidative enzymes participate in the process of resisting environmental stress by eliminating excess ROS. In the present study, we identify two superoxide dismutase (SOD), one catalase (CAT), six peroxidases (POD), and five glutathione-S-transferase (GST) genes; and the survival rate and antioxidative enzyme patterns under short-term high temperature exposure of the parasitoid wasp, A.asychis, are examined. Survival results of A.asychis reveal that females show higher thermal tolerance than males. Under short-term high-temperature exposure, in females, the expression levels of most antioxidant enzyme genes decreased first and then increased to a peak at 41 °C, while only the expression of AasyGST4 showed a continuous increase. In males, the expression patterns of most antioxidant enzyme genes fluctuated and reached a maximum at 41 °C. Moreover, the expression levels of the majority of antioxidant enzyme genes were higher in females than in males. In addition, at temperatures of and above 35 °C, the activities of these four antioxidant enzymes were induced. The results show that the antioxidant enzymes confer thermo-tolerance to A. asychis against lethal thermal stress. Our observations enrich the understanding of the response mechanism to high-temperature assaults of A. asychis.

Repro-protective role of royal jelly in phenylhydrazine-induced hemolytic anemia in male mice: Histopathological, embryological, and biochemical evidence

To estimate the repro-protective effect of royal jelly (RJ) on phenylhydrazine (PHZ)-induced anemia's detrimental effects, 24 mature mice were divided into control group (0.10 mL normal saline; intra-peritoneally), RJ group (100 mg/kg/day; orally), experimental anemia (EA) group that received only PHZ (6 mg/100 g/48 h; intra-peritoneally), and RJ + EA (according to the previous prescription) group. After 35 days, testicular histoarchitecture, RNA damage in germinal cells, sperm characteristics, testicular total anti-oxidant capacity and malondialdehyde as well as serum testosterone levels, pre-implantation embryo development and cyclin D1 and c-myc mRNA levels at two-cell, morula and blastocyst stages were analyzed. Spermatogenesis indices were ameliorated following RJ co-administration. Moreover, RJ co-treatment reduced germinal cells RNA damage, improved sperm characteristics, boosted pre-implantation embryo development and restored androgenesis, and oxidant/anti-oxidant status. Co-administration of RJ also decreased mRNA levels of cyclin D1 and up-regulated those of c-myc in two-cell embryos, morulas and blastocysts. The findings suggest that RJ can play a repro-protective role in PHZ-induced anemia in mice through anti-oxidant defense system reinforcement and androgenesis restoration as well as cyclin D1 and c-myc expressions regulation.

Physiological role of reactive oxygen species in testis and epididymal spermatozoa

The reactive oxygen species (ROS) play an important role in various aspects of male reproductive function, for spermatozoa to acquire the ability to fertilize. However, the increase in ROS generation, both due to internal and external factors, can induce oxidative stress, causing alterations in the structure and function of phospholipids and proteins. In the nucleus, ROS attack DNA, causing its fragmentation and activation of apoptosis, thus altering gene and protein expression. Accumulating evidence also reveals that endogenously produced ROS can act as second messengers in regulating cell signalling pathways and in the transduction of signals that are responsible for regulating spermatogonia self-renewal and proliferation. In the epididymis, they actively participate in the formation of disulphide bridges required for the final condensation of chromatin, as well as in the phosphorylation and dephosphorylation of proteins contained in the fibrous sheath of the flagellum, stimulating the activation of progressive motility in epididymal spermatozoa. In this review, the role of small amounts of ROS during spermatogenesis and epididymal sperm maturation was discussed.

Temperature response of enriched pre-pubertal caprine male germline stem cells in vitro

The present study aims to evaluate culture temperature-dependent variation in survival, growth characteristics and expression of stress, pluripotency, apoptosis, and adhesion markers in enriched caprine male germline stem cells (cmGSCs). For this, testes from pre-pubertal bucks (4-5 months; n = 4) were used to isolated cells by a two-step enzymatic digestion method. After enrichment of cmGSCs by multiple methods (differential platting, Percoll density gradient centrifugation, and MACS), viability of CD90+ cells was assessed before co-cultured onto the Sertoli cell feeder layer at different temperatures (35.5, 37.0, 38.5, and 40.0 °C). The culture characteristics of cells were compared with MTT assay (viability); cluster-forming activity assay, SA-β1-gal assay (senescence), BrdU assay (proliferation), and transcript expression analyses by qRT-PCR. Moreover, the co-localization of pluripotency markers (UCHL-1, PLZF, and DBA) was examined by a double-immunofluorescence method. The cells grown at 37.0 °C showed faster proliferation with a significantly (p < 0.05) higher number of viable cells and greater number of cell clusters, besides higher expression of pluripotency markers. The transcript expression of HSPs (more noticeably HSP72 than HSP73), anti-oxidative enzymes (GPx and CuZnSOD), and adhesion molecule (β1-integrin) was significantly (p < 0.05) downregulated when grown at 35.0, 38.5, or 40.0 °C compared with 37.0 °C. The expression of pluripotency-specific transcripts was significantly (p < 0.05) lower in cmGSCs grown at the culture temperature lower (35.5 °C) or higher (38.5 °C and 40.0 °C) than 37.0 °C. Overall, the culture temperature significantly affects the proliferation, growth characteristics, and expression of heat stress, pluripotency, and adhesion-specific markers in pre-pubertal cmGSCs. These results provide an insight to develop strategies for the improved cultivation and downstream applications of cmGSCs.

Differential regulation of antioxidant enzymes in Frankliniella occidentalis (Thysanoptera: Thripidae) exposed to thermal stress

Frankliniella occidentalis is an invasive insect pest that incites damage to ornamental and agronomic crops on a global scale. In this study, the effects of temperature on gene expression and enzyme activity were studied for superoxide dismutase (SOD), peroxidase (POD), and glutathione-S-transferase (GST) in F. occidentalis. SOD, POD and GST enzyme activity increased significantly at 35–37 °C but declined as the temperature increased to 41 °C. In a time course study at 35 °C, SOD, POD and GST activities were significantly elevated at 0.5, 1 and 2 h in comparison to the control at 26 °C. Expression patterns were evaluated for the three antioxidant genes under high and low temperature stress. In a time course study at –4 °C, SOD, POD and GST expression peaked at 1 h and declined at 2 h of exposure. In contrast, when transcription was monitored at 35 °C, expression was lowest at 1 h and increased at 2 h. The results provide data that will be useful in deciphering the role of antioxidant enzymes in the adaptation of F. occidentalis to climate change.

Chondroitin sulfate produces antinociception and neuroprotection in chronic constriction injury-induced neuropathic pain in rats by increasing anti-inflammatory molecules and reducing oxidative stress

OBJECTIVES

Damage to the peripheral and central nervous system lead to Neuropathic pain (NP) which is a widespread and devitalizing condition. chondroitin sulfate (CS), has been used in managing joint pain and osteoarthritis. In this study, the effectiveness of CS on NP induced by chronic constriction injury (CCI) is examined.

METHODS

Thirty Wistar rats were distributed at random into six groups (n = 5). Sciatic nerve ligation was carried out by encircling the nerve with four loose ligatures to induce NP. Allodynia (cold and mechanical) and heat hyperalgesia were assessed using Acetone, von Frey filament and Hot plate tests. CCI induction resulted to NP, prominent from the 3rd day after surgery. Structural architecture of sciatic nerves was evaluated via histological examination of the transverse section of the nerves.

RESULTS

Oral administration of CS (600 mg/kg and 900 mg/kg for 21 days) resulted in significant (P < 0.05) inhibition of allodynia (cold and mechanical) and thermal hyperalgesia. Lipid peroxidation, tumor necrosis factor-α (TNF-α), calcitonin gene related peptide (CGRP), C reactive protein (CRP), and oxidative stress were attenuated by CS. CS also improved interleukin (IL)-6, nitric oxide (NO), total antioxidant capacity (TAC).

CONCLUSION

These findings suggest that CS attenuates allodynia, and thermal hyperalgesia induced by CCI by downregulating TNF-α, CRP, CGRP, oxidative enzymes, and upregulating IL-6, NO, and TAC. Nociceptive behavioral studies and histological findings showed significant improvement in the CS treated groups compared to CCI rats. These findings are responsible for the beneficial effect of CS in NP.

New Galantamine Derivatives with Inhibitory Effect on Acetylcholinesterase Activity

BACKGROUND

Inhibitors of acetylcholinesterase (AChE) are used to treat many disorders, among which are neurodegenerative upsets, like Alzheimer's disease (AD). One of the limited licensed AChE inhibitors (AChEIs) used as drugs is the natural compound galantamine (Gal).

OBJECTIVE

As Gal is a toxic compound, here we expose data about its four derivatives in hybrid peptide-norgalantamine molecules, which have shown 100 times lower toxicity.

METHODS

Four newly synthesized galantamine derivatives have been involved in docking analysis made by Molegro Virtual Docker. Biological assessments were performed on ICR male mice. The change in short and long-term memory performance was evaluated by passive avoidance test. AChE activity and levels of main oxidative stress parameters: lipid peroxidation, total glutathione (GSH), enzyme activities of catalase (CAT), superoxide dismutase, and glutathione peroxidase were measured in brain homogenates.

RESULTS

Our experimental data revealed that the new hybrid molecules did not impair memory performance in healthy mice. Two of the compounds demonstrated better than Gal AChE inhibitory activity in the brain. None of them changed the level of lipid peroxidation products, one of the compounds increased GSH levels, and all of them increased CAT enzyme activity.

CONCLUSION

The new galantamine-peptide hybrids demonstrated a potential for inhibition of AChE and antioxidant activity and deserve further attention.

Antioxidant or Apoptosis Inhibitor Supplementation in Culture Media Improves Post-Thaw Recovery of Murine Spermatogonial Stem Cells

We postulated that supplementation of antioxidant or apoptosis inhibitor in post-thaw culture media of spermatogonial stem cells (SSCs) alleviates reactive oxygen species (ROS) generation and apoptosis. Our aim was to develop an effective culture media for improving post-thaw recovery of SSCs. To determine the efficacy of supplementation with hypotaurine (HTU), α-tocopherol (α-TCP), and Z-DEVD-FMK (ZDF), we assessed the relative proliferation rate and SSC functional activity and performed a ROS generation assay, apoptosis assay, and western blotting for determination of the Bax/Bcl-xL ratio, as well as immunocytochemistry and real-time quantitative polymerase chain reaction (RT-qPCR) for SSC characterization. The relative proliferation rates with HTU 400 μM (133.7 ± 3.2%), α-TCP 400 μM (158.9 ± 3.6%), and ZDF 200 μM (133.1 ± 7.6%) supplementation were higher than that in the DMSO control (100 ± 3.6%). ROS generation was reduced with α-TCP 400 μM (0.8-fold) supplementation in comparison with the control (1.0-fold). Early apoptosis and Bax/Bcl-xL were lower with α-TCP 400 μM (2.4 ± 0.4% and 0.5-fold) and ZDF 200 μM (1.8 ± 0.4% and 0.3-fold) supplementation in comparison with the control (5.3 ± 1.4% and 1.0-fold) with normal characterization and functional activity. Supplementation of post-thaw culture media with α-TCP 400 μM and ZDF 200 μM improved post-thaw recovery of frozen SSCs via protection from ROS generation and apoptosis after cryo-thawing.

FRET-Based Genetically Encoded Nanosensor for Real-Time Monitoring of the Flux of α-Tocopherol in Living Cells

Vitamin E plays an exemplary role in living organisms. α-Tocopherol is the most superior and active form of naturally occurring vitamin E that meets the requirements of human beings as it possesses the α-tocopherol transfer protein (α-TTP). α-Tocopherol deficiency can lead to severe anemia, certain cancers, several neurodegenerative and cardiovascular diseases, and most importantly male infertility. As a result of the depletion of its natural sources, researchers have tried to employ metabolic engineering to enhance α-tocopherol production to meet the human consumption demand. However, the metabolic engineering approach relies on the metabolic flux of a metabolite in its biosynthetic pathway. Analysis of the metabolic flux of a metabolite needs a method that can monitor the α-tocopherol level in living cells. This study was undertaken to construct a FRET (fluorescence resonance energy transfer)-based nanosensor for monitoring the α-tocopherol flux in prokaryotic and eukaryotic living cells. The human α-TTP was sandwiched between a pair of FRET fluorophores to construct the nanosensor, which was denoted as FLIP-α (the fluorescence indicator for α-tocopherol). FLIP-α showed excellence in monitoring the α-tocopherol flux with high specificity. The sensor was examined for its pH stability for physiological applications, where it shows no pH hindrance to its activity. The calculated affinity of this nanosensor was 100 μM. It monitored the real-time flux of α-tocopherol in bacterial and yeast cells, proving its biocompatibility in monitoring the α-tocopherol dynamics in living cells. Being noninvasive, FLIP-α provides high temporal and spatial resolutions, which holds an indispensable significance in bioimaging metabolic pathways that are highly compartmentalized.

Molecular Regulation of Copper Homeostasis in the Male Gonad during the Process of Spermatogenesis

Owing to its redox properties, copper is a cofactor of enzymes that catalyze reactions in fundamental metabolic processes. However, copper-oxygen interaction, which is a source of toxic oxygen radicals generated by the Fenton reaction, makes copper a doubled-edged-sword in an oxygen environment. Among the microelements influencing male fertility, copper plays a special role because both copper deficiency and overload in the gonads worsen spermatozoa quality and disturb reproductive function in mammals. Male gametes are produced during spermatogenesis, a multi-step process that consumes large amounts of oxygen. Germ cells containing a high amount of unsaturated fatty acids in their membranes are particularly vulnerable to excess copper-mediated oxidative stress. In addition, an appropriate copper level is necessary to initiate meiosis in premeiotic germ cells. The balance between essential and toxic copper concentrations in germ cells at different stages of spermatogenesis and in Sertoli cells that support their development is handled by a network of copper importers, chaperones, recipient proteins, and exporters. Here, we describe coordinated regulation/functioning of copper-binding proteins expressed in germ and Sertoli cells with special emphasis on copper transporters, copper transporting ATPases, and SOD1, a copper-dependent antioxidant enzyme. These and other proteins assure copper bioavailability in germ cells and protection against copper toxicity.

Ultrasonic-assisted extraction of polysaccharides from Auricularia auricula and effects of its acid hydrolysate on the biological function of Caenorhabditis elegans

The present study was designed to explore the in vivo-antioxidant capacity and the probable mechanism of AAPs-H, prepared from Auricularia auricula polysaccharides with the optimal extraction conditions by Box-Behnken design and acid hydrolysis, using Caenorhabditis elegans as a model organism. The effects of AAPs-H on the locomotion behavior, life span, antioxidant-related enzymes activities, and antioxidants levels in C. elegans were studied. Furthermore, the potentials of AAPs-H in up-regulating the expression of antioxidant-related genes in C. elegans, such as skn-1, sod-3 and sir-2.1, were also discussed. AAPs-H demonstrated a highly significant protective effect against the damage caused by paraquat, could significantly increase U-Turn frequency of worms (p < 0.01), extend their lifespan, enhance antioxidant systems including GR by 63.96% (p < 0.05), GSH-Px by 71.16% (p < 0.01), SOD by 78.65% (p < 0.01) and CAT by 98.52% (p < 0.01), increase the level of GSH by 28.12% (p < 0.05), and decrease the level of MDA by 39.29% (p < 0.01). The qRT-PCR results showed that AAPs-H could up regulate mRNA expression levels of skn-1, sod-1, sod-2, sod-3 and sir-2.1 in wild-type C. elegans (>1.6 fold) when treated with the concentration of 0.4 mg/mL (p < 0.05 or p < 0.01). Our studies provide evidence that AAPs-H improves antioxidant defense system, and up-regulation of oxidative stress related genes for prevention of stress damage in C. elegans.

Effect of food plants on Spodoptera litura (Lepidoptera: Noctuidae) larvae immune and antioxidant properties in response to Bacillus thuringiensis infection

The larvae of Spodoptera litura (Fabricius) were reared on five host plants, Brassica oleracea, Nicotiana tabacum, Ricinus communis, Gossypium hirsutum, and Arachis hypogaea. The larvae were immunized with Bacillus thuringiensis to observe the immune response. The results of total and differential hemocyte count were increased in B. oleracea, N. tabacum, and R. communis fed S. litura larval hemolymph. Similar results were observed in the parameter of nodulation, melanization, and phenoloxidase. Total protein was higher in R. communis fed larvae. Antioxidant levels like Catalase (CAT), Superoxide dismutase (SOD), Glutathione S- transferase (GST), Peroxidase (POX), Lipid peroxidase (LPO), and Esterase (EST) was found in moreover all plant-feeding insect. High CAT activity was observed 2-6 h in R. communis, G. hirsutum, and A. hypogaea fed S. litura larval midgut and fatbody samples. Increased SOD activity in both midgut and fatbody at 2-12 h of B. oleracea, G. hirsutum, and A. hypogaea fed. GST activity was increased initially 2-6 h in G. hirsutum and A. hypogaea. Increased POX activity was observed initially in all treated groups. Highest LPO observed at 6 h in N. tabacum in both midgut and fatbody. Whereas increased EST activity was observed in N. tabacum and B. oleracea. The results of the present study shows that nature of food influence the immunity against Bt infection. This information can be very useful for incorporating biological control program for insect pest.

Melatonin daily oral supplementation attenuates inflammation and oxidative stress in testes of men with altered spermatogenesis of unknown aetiology

We have previously shown an inverse correlation between testicular melatonin concentration and inflammation/oxidative stress-related markers levels in infertile men showing unexplained azoospermia. Here, we evaluated the impact of melatonin oral supplementation (daily 3 mg dose used to treat sleep disorders) in the incidence of local inflammation, oxidative stress, and tubular wall fibrosis development in young and middle-aged infertile adult men. Compared with testes without histological alterations, gonads with morphological abnormalities showed lower melatonin concentration along with increased macrophage numbers, TBARS generation, and expression levels of inflammation-related markers and antioxidant enzymes, as well as tubular wall collagen fibers disorganization and thickening. Melatonin oral supplementation not only increased its own testicular levels but also decreased inflammation- and oxidative stress-related markers levels, and improved the tubular wall aspect. Overall, our work provides insights into the potential benefits of melatonin on the inflammatory and oxidative status in testes of patients suffering from unexplained infertility.

Molecular machinery providing copper bioavailability for spermatozoa along the epididymial tubule in mouse

Progressive functional maturation of spermatozoa is completed during the transit of these cells through the epididymis, a tubule structure connecting a testicle to a vas deferens. Epididymal epithelial cells by means of their secretory and absorptive functions determine a highly specialized luminal microenvironment containing multiple organic and inorganic components. The latter include copper ions, which due to their redox properties are indispensable for critical homeostatic processes occurring in spermatozoa floating in different part of epididymis but can be potentially toxic. Main purpose of our study was to determine epididymal region-dependent expression and localization of copper transporters ensuring a tight control of copper concentration in epididymal fluid. We also aimed at identifying proteins responsible for copper uptake by spermatozoa and verifying whether this process is coordinated with copper supply to superoxide dismutase 1 (SOD1), a copper-dependent antioxidant enzyme. Our study identifies two ATPases-ATP7A, ATP7B and Slc31a1, major copper importers/exporters depending on their differential expression on epididymal polarized epithelial cells of the caput, corpus, and cauda. Next, ceruloplasmin seems to be a chief protein transporting copper in the epididymal fluid and providing this biometal to spermatozoa. The entry of copper to germ cells is mediated by Slc31a1 and is correlated with both expressions of copper chaperone for superoxide dismutase (CCS), copper chaperone directly providing copper ions to SOD1 and with the expression and activity of the latter. Our results outline a network of cooperating copper binding proteins expressed in epididymal epithelium and in spermatozoa that orchestrate bioavailability of this microelement for gametes and protect them against copper toxicity.

Lethal and sublethal effect of heat shock on Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae)

Temperature is an important abiotic environmental factor, and is responsible for various kinds of behavioral and physiological changes in living organisms. Induced heat shock is associated with feeding behaviour, reproduction and reactive oxygen species (ROS) generation that causes oxidative damage. In this experiment, we examined the lethal and sublethal effects of heat shock on reproduction, feeding behaviour and antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD) and peroxidases (POD) in P. solenopsis. Results showed that males were highly susceptible to heat shock treatments than females, as LTemp₅₀ values were 43.8 °C for males and 45.11 °C for females. Heat shock events non-significantly affected the fecundity in female only treated adults and significantly affected the both sexes heat treated adults, it increased the xylem feeding duration, percentage of xylem feeding adults and reduce the phloem feeding duration and percentage of phloem feeding adults. Similarly it alter the antioxidant enzymes activities, an increase of CAT, SOD and POD activities were noticed in response to highest intensity of heat shock while a reduction of CAT and SOD activity were noticed in response to lowest intensity of heat shock compared to control (30 °C). These results suggest that heat shock may result in loss of body water and induce oxidative stress in P. solenopsis. However, antioxidant enzymes play a significant role in overcoming the oxidative damage.

A Brazilian pulp and paper mill effluent disrupts energy metabolism in immature rat testis and alters Sertoli cell secretion and mitochondrial activity

Our objective was to investigate whether the pulp and paper mill industry effluent could affect the testis and Sertoli cells in a fast exposure period. For this, the present study was carried out in immature rats at 10-day-old. Testis treated in vitro with 4% effluent for 1 h presented changes in energy metabolism in terms of a decrease in lactate content and glucose uptake. Elevation in GSH content, as an antioxidant defense mechanism, was also detected. Sertoli cells treated with 4% effluent for 1 hour showed alterations in the mitochondrial metabolism that favor the decoupling of oxidative phosphorylation and the generation of oxygen reactive species and also a time and concentration-dependent delay secretion of acidic vesicles. Our results showed that pollutants present in the pulp and paper mill effluents, in a short time of exposure, are capable of inducing alterations in important metabolic functions in the testis and in Sertoli cells that are crucial for the correct progression of spermatogenesis and fertility.

Chronic excessive Zn intake increases the testicular sensitivity to high ambient temperature in Bama miniature pigs

Zinc (Zn) can accumulate in the body of wild animal and human through bio-magnification effects in the food chain to pose chronic toxicity. Male spermatogenesis was sensitive to excessive Zn and elevated temperature. This study aimed to examine whether or not excessive Zn intake caused testicular toxicity and estimate the interaction between Zn and high temperature (HT) in testes of Bama miniature pigs. Six-month-old pigs were pre-fed with or without additional Zn at 1500 mg/kg diet for 30 d and afterward subjected to HT at 40 °C for 5 h daily for 8 consecutive days. Blood samples were collected on d 31 and d 38 and testes were obtained on d 38 immediately after HT exposure. Our data showed both scrotal surface temperature (T) and body surface T increased after 5-h HT exposure (p < 0.05). Pigs fed with additional Zn showed germ cell loss, the decreased testes weight (p < 0.01) and the elevated testicular H₂O₂ level (p < 0.05) as exposed to HT. In additional Zn groups, the autophagosomes or autolysosomes were more frequently observed in the Leydig cells and abnormal acrosomes increased in spermatids. Additional Zn diet increased p62 protein level (p < 0.05), decreased testicular Zn concentration (p < 0.01) and down-regulated the relative mRNA expression of heme oxygenase 1 (p < 0.05). There were significant interactions between T and Zn on testes weight, the relative weight of testes, testosterone concentration on d 31, and the relative mRNA expression of Zn transporters 1 and 2. In conclusion, chronic excessive Zn diet impacted testicular Zn concentration and made the testes more vulnerable to heat, leading to testicular toxicity in Bama miniature pigs.

Comparison between the Effects of Adding Vitamins, Trace Elements, and Nanoparticles to SHOTOR Extender on the Cryopreservation of Dromedary Camel Epididymal Spermatozoa

Simple Summary

This is a comprehensive study to compare between the effects of different supplements (vitamins C and E, trace elements Na₂SeO₃ and ZnSO₄, and nanoparticles of zinc oxide and selenium) to the semen extender of camel epididymal spermatozoa during cooling and freezing/thawing cryopreservation. Supplementation of the semen SHOTOR extender with zinc oxide and selenium nanoparticles lead to improved progressive motility, vitality, and anti-oxidative defense, and reduced the ultrastructural abnormalities in camel epididymal spermatozoa.

Abstract

There are several obstacles in camel semen cryopreservation; such as increasing semen viscosity and the reduction in motile spermatozoa after ejaculation. Epididymal spermatozoa offer an efficient alternative to overcome these problems and are well-suited for artificial insemination in camels. In the current study, we compared the effects of supplementation with vitamin C, E, inorganic trace elements of selenium (Na₂SeO₃) and zinc (ZnSO₄), and zinc and selenium nanoparticles (ZnONPs and SeNPs, respectively) on the cryopreservation of dromedary camel epididymal spermatozoa. When the SHOTOR extender was supplemented with ZnONPs and SeNPs; the sperm showed increased progressive motility; vitality; and membrane integrity after cooling at 5 °C for 2 h; when compared to the control and vitamin-supplemented groups. Moreover, the ZnONPs and SeNPs supplementation improved the progressive motility, vitality, sperm membrane integrity, ultrastructural morphology, and decreased apoptosis when frozen and thawed. SeNPs significantly increased reduced glutathione (GSH), superoxide dismutase (SOD), and decreased lipid peroxide malondialdehyde (MDA) levels. The advantageous effects of the trace elements were potentiated by reduction into a nano-sized particle, which could increase bioavailability and reduce the undesired liberation of toxic concentrations. We recommend the inclusion of SeNPs or ZnONPs to SHOTOR extenders to improve the cryotolerance of camel epididymal spermatozoa.

The inflammatory mediators TNFα and nitric oxide arrest spermatogonia GC-1 cell cycle

During an inflammatory process of the testis, the network of somatic, immune, and germ cell interactions is altered leading to organ dysfunction. In testicular biopsies of infertile men, spermatogenesis impairment is associated with reduced spermatogonia proliferation, increased number of immune cells, and content of pro-inflammatory cytokines. TNFα-TNFR and nitric oxide (NO)-NO synthase systems are up-regulated in models of testicular damage and in human testis with maturation arrest. The purpose of this study was to test the hypothesis that TNFα-TNFR system and NO alter the function of spermatogonia in the inflamed testis. We studied the effect of TNFα and NO on GC-1 spermatogonia cell cycle progression and death by flow cytometry. GC-1 cells expressed TNFR1 and TNFR2 (immunofluorescence). TNFα (10 and 50 ng/ml) and DETA-Nonoate (0.5 and 2 mM), a NO releaser, increased the percentage of cells in S-phase of the cell cycle and reduced the percentage in G1, inducing also cell apoptosis. TNFα effect was not mediated by oxidative stress unlike NO, since the presence of N-acetyl-l-cysteine (2.5 and 5.0 mM) prevented NO induced cell cycle arrest and death. GC-1 spermatogonia overpass NO induced cell cycle arrest but no TNFα, since after removal of NO, spermatogonia progressed through the cell cycle. We propose TNFα and NO might contribute to impairment of spermatogenesis by preventing adequate functioning of the spermatogonia population. Our results showed that TNFα and NO impaired spermatogonia cell cycle, inducing GC-1 arrest in the S phase.

A new paradigm regarding testicular thermoregulation in ruminants?

Increased testicular temperature reduces percentages of morphologically normal and motile sperm and fertility. Specific sperm defects appear at consistent intervals after testicular hyperthermia, with degree and duration of changes related to intensity and duration of the thermal insult. Regarding pathogenesis of testicular hyperthermia on sperm quality and fertility, there is a long-standing paradigm that: 1) testes operate near hypoxia; 2) blood flow to the testes does not increase in response to increased testicular temperature; and 3) an ensuing hypoxia is the underlying cause of heat-induced changes in sperm morphology and function. There are very limited experimental data to support this paradigm, but we have data that refute it. In 2 × 3 factorial studies, mice and rams were exposed to two testicular temperatures (normal and increased) and three concentrations of O₂ in inspired air (hyperoxia, normoxia and hypoxia). As expected, increased testicular temperature had deleterious effects on sperm motility and morphology; however, hyperoxia did not prevent these changes nor did hypoxia replicate them. In two follow-up experiments, anesthetized rams were sequentially exposed to: 1) three O₂ concentrations (100, 21 and 13% O₂); or 2) three testicular temperatures (33, 37 and 40 °C). As O₂, decreased, testis maintained O₂ delivery and uptake by increasing testicular blood flow and O₂ extraction, with no indication of anaerobic metabolism. Furthermore, as testicular temperature increased, testicular metabolic rate nearly doubled, but increased blood flow and O₂ extraction prevented testicular hypoxia and anaerobic metabolism. In conclusion, our data, in combination with other reports, challenged the paradigm that testicular hyperthermia fails to increase testicular blood flow and the ensuing hypoxia disrupts spermatogenesis.

Heat exposure induces oxidative stress and DNA damage in the male germ line

The reproductive consequences of global warming are not currently understood. In order to address this issue, we have examined the reproductive consequences of exposing male mice to a mild heat stress. For this purpose, adult male mice were exposed to an elevated ambient temperature of 35°C under two exposure models. The first involved acute exposure for 24 h, followed by recovery periods between 1 day and 6 weeks. The alternative heating regimen involved a daily exposure of 8 h for periods of 1 or 2 weeks. In our acute model, we identified elevated sperm mitochondrial ROS generation (P < 0.05), increased sperm membrane fluidity (P < 0.05), DNA damage in the form of single-strand breaks (P < 0.001), and oxidative DNA damage (P < 0.05), characteristic of an oxidative stress cascade. This DNA damage was detected in pachytene spermatocytes (P < 0.001) and round spermatids (P < 0.001) isolated from testes after 1 day heat recovery. Despite these lesions, the spermatozoa of heat-treated mice exhibited no differences in their ability to achieve hallmarks of capacitation or to fertilize the oocyte and support development of embryos to the blastocyst stage (all P > 0.05). Collectively, our acute heat stress model supports the existence of heat susceptible stages of germ cell development, with the round spermatids being most perturbed and spermatogonial stem cells exhibiting resistance to this insult. Such findings were complemented by our chronic heat stress model, which further supported the vulnerability of the round spermatid population.

The initiation of puberty in Atlantic salmon brings about large changes in testicular gene expression that are modulated by the energy status

Background

When puberty starts before males reach harvest size, animal welfare and sustainability issues occur in Atlantic salmon (Salmo salar) aquaculture. Hallmarks of male puberty are an increased proliferation activity in the testis and elevated androgen production. Examining transcriptional changes in salmon testis during the transition from immature to maturing testes may help understanding the regulation of puberty, potentially leading to procedures to modulate its start. Since differences in body weight influence, via unknown mechanisms, the chances for entering puberty, we used two feed rations to create body weight differences.

Results

Maturing testes were characterized by an elevated proliferation activity of Sertoli cells and of single undifferentiated spermatogonia. Pituitary gene expression data suggest increased Gnrh receptor and gonadotropin gene expression, potentially responsible for the elevated circulating androgen levels in maturing fish. Transcriptional changes in maturing testes included a broad variety of signaling systems (e.g. Tgfβ, Wnt, insulin/Igf, nuclear receptors), but also, activation of metabolic pathways such as anaerobic metabolism and protection against ROS. Feed restriction lowered the incidence of puberty. In males maturing despite feed restriction, plasma androgen levels were higher than in maturing fish receiving the full ration. A group of 449 genes that were up-regulated in maturing fully fed fish, was up-regulated more prominently in testis from fish maturing under caloric restriction. Moreover, 421 genes were specifically up-regulated in testes from fish maturing under caloric restriction, including carbon metabolism genes, a pathway relevant for nucleotide biosynthesis and for placing epigenetic marks.

Conclusions

Undifferentiated spermatogonia and Sertoli cell populations increased at the beginning of puberty, which was associated with the up-regulation of metabolic pathways (e.g. anaerobic and ROS pathways) known from other stem cell systems. The higher androgen levels in males maturing under caloric restriction may be responsible for the stronger up-regulation of a common set of (449) maturation-associated genes, and the specific up-regulation of another set of (421) genes. The latter opened regulatory and/or metabolic options for initiating puberty despite feed restriction. As a means to reduce the incidence of male puberty in salmon, however, caloric restriction seems unsuitable.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5869-9) contains supplementary material, which is available to authorized users.

In Vivo and In Vitro Antioxidant Activities of Methanol Extracts from Olive Leaves on Caenorhabditis elegans

The aim of this study was to evaluate the antioxidant activities of extracts from olive leaves (EOL). The main contents of EOL were determined by colorimetric methods. The antioxidant activities were assessed by measuring the scavenging free radicals in vitro. To investigate the antioxidant activity in vivo, we detected the survival of Caenorhabditis elegans, under thermal stress. Subsequently the reactive oxygen species (ROS) level, activities of antioxidant enzymes, the expression of HSP-16.2 and the translocation of daf-16 were measured. The results showed that, polyphenols was the main component. EOL could well scavenge DPPH and superoxide anion radicals in vitro. Compared to the control group, the survival rate of C. elegans treated with EOL was extended by 10.43%, under heat stress. The ROS level was reduced, while the expression of hsp-16.2 was increased to protect the organism against the increasing ROS. The level of malondialdehyde (MDA) also decreased sharply. The activities of inner antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were potentiated, which might have had a correlation with the DAF-16 transcription factor that was induced-turned into the nuclear. Therefore, EOL showed a strong antioxidant ability in vitro and in vivo. Hence, it could be a potential candidate when it came to medicinal and edible plants.

Antioxidant Responses of Ragweed Leaf Beetle Ophraella communa (Coleoptera: Chrysomelidae) Exposed to Thermal Stress

Ophraellacommuna LeSage is an effective biological control agent of common ragweed, Ambrosia artemisiifolia L., which competes with crops and causes allergic rhinitis and asthma. However, thermal stress negatively affects the developmental fitness and body size of this beetle. High temperatures cause a variety of physiological stress responses in insects, which can cause oxidative damage. We investigated the total protein content and activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidases (PODs) in O. communa adults when its different developmental stages were exposed to high temperatures (40, 42, and 44°C) for 3 h each day for 3, 5, 5, and 5 days, respectively (by stage), and a whole generation to high temperatures (40, 42, and 44°C) for 3 h each day. A control group was reared at 28 ± 2°C. Under short-term daily phasic high-temperature stress, total protein contents were close to the control as a whole; overall, SOD activities increased significantly, CAT activities were closer to or even higher than the control, POD activities increased at 40°C, decreased at 42 or 44°C; stage-specific response was also observed. Under long-term daily phasic high-temperature stress, total protein content increased significantly at 44°C, SOD activities increased at higher temperatures, decreased at 44°C; CAT activities of females increased at ≤42°C, and decreased at 44°C, CAT activities of males decreased significantly; POD activities of females increased at 40°C, decreased at ≥42°C, POD activities of males decreased at 44°C; and antioxidant enzymes activities in females were significantly higher than those in males. Antioxidative enzymes protect O. communa from oxidative damage caused by thermal stress.

Atp7a and Atp7b regulate copper homeostasis in developing male germ cells in mice

The maintenance of copper homeostasis is critical for all cells. As learned from mice with disturbed copper metabolism, this trace element is also important for spermatogenesis. The experiments conducted in yeasts have demonstrated that appropriate copper level must be preserved to enable meiosis progression; however, increased copper level is toxic for cells. This study aims to analyze the expression profile of Atp7a and Atp7b and other genes encoding copper-related proteins during spermatogenesis in mice. Using the transcripts and protein detection techniques, we demonstrate that within seminiferous tubuli, ATP7A is mainly present in early meiotic germ cells (leptotene to pachytene spermatocytes) and in Sertoli cells (SCs). During spermatogenesis, the progression Atp7a expression profile corresponds to Slc31a1 (encoding copper importer CTR1) and Atox1 (encoding chaperon protein, which delivers copper from CTR1 to ATP7A and ATP7B) expression, suggesting that male germ cells retrieve copper and ATP7A protects them from copper overdose. In contrast, ATP7B protein is observed in SCs and near elongated spermatids; thus, its function seems to be related to copper extraction during spermiogenesis. This is the first study to give a comprehensive view on the activity of copper-related genes during spermatogenesis in mice.

Protective effects of camel whey protein against scrotal heat-mediated damage and infertility in the mouse testis through YAP/Nrf2 and PPAR-gamma signaling pathways

Elevation of scrotal temperature is one of the most important causes of impaired spermatogenesis and male infertility, but the exact mechanism remains controversial. The present study investigated the impact of camel whey protein (CWP) on the mechanisms of heat stress (HS)-mediated testicular damage in male mice. Exposure to HS was associated with significant increase in the testicular tissues' oxidative stress. Mechanistically, exposure to HS resulted in upregulation of P53 and Nrf2 expressions; downregulation of Bcl2 and PPAR-γ expressions; and induction of testicular Leydig cell hyperplasia. Because Leydig cells produce testosterone up on stimulation with Luteinizing hormone (LH), HS mice also exhibited significant reduction in the serum testosterone levels followed by significant reduction in the percentages of progressively motile sperm and higher percentages of immotile sperm, when compared with those of control mice. Interestingly, treatment of HS mice with CWP significantly restored the levels of ROS and the activities of antioxidant enzymes in the testicular tissues nearly to those observed in control mice. Furthermore, CWP supplemented HS mice exhibited complete restoration of Bcl2, P53, Nrf2, and PPAR-γ expressions; testicular Leydig cell distribution; significant higher levels of testosterone levels; and hence higher percentages of progressively motile sperm and lower percentages of immotile sperm as compared to HS mice. Our findings reveal the protective effects of CWP against testis injury and infertility induced by exposure to HS by rescuing functional Leydig cells. Additionally, the present study has shed light on the molecular mechanisms underlying improved testicular damage following CWP treatment.

Effects of co-exposure to lead and zinc on redox status, kidney variables, and histopathology in adult albino rats

Lead (Pb) is a toxic metal that induces a wide range of biochemical and physiological effects in humans. Oxidative damage has been proposed as a possible mechanism involved in Pb toxicity. The current study was carried out to evaluate the antioxidant activities of zinc (Zn) supplement against lead acetate-induced kidney injury in rats. In this study, adults male rats were treated for 15 days with Pb (0.344 g/kg body weight (bw)) associated or not with Zn (10 mg/kg bw). Our study showed that supplementation with Zn prevented renal dysfunction as indicated by plasma biomarkers (urea, uric acid, creatinine, lactate dehydrogenase, and alkaline phosphatase levels) and oxidative stress-related parameters (thiobarbituric acid reactive substances, protein carbonyl, advanced oxidation protein product, superoxide dismutase, catalase, glutathione peroxidase, and vitamins (A, E)) in kidney tissue. The corrective effect of Zn on Pb-induced kidney nephrotoxicity recovered normal kidney histology. Overall, this study indicates that Zn alleviated the toxic effects of this heavy metal on renal tissue, suggesting its role as a potential antioxidant and nephroprotective agent.

In vitro study of doxorubicin-induced oxidative stress in spermatogonia and immature Sertoli cells

Pediatric chemotherapy treatments can impair long-term male fertility. Unfortunately, no fertility preservation solution is available for pre-pubertal boys. Studies suggest that doxorubicin, used against pediatric cancers, induces oxidative stress in the testis. However, the targeted testicular cell types remain unknown. The goal of this study was to determine whether doxorubicin can induce oxidative stress in rat spermatogonia (GC-6Spg) and immature Sertoli (Ser-W3) cell lines, and to assess their protection by antioxidants. Using the MTT assay, we have shown that doxorubicin induces a time- and dose-dependent cytotoxicity in these two cell lines, Ser-W3 being more sensitive than GC-6Spg. After 3 h of treatment, reactive oxygen species and nuclear 8-oxo-deoxyguanosine increase in Ser-W3, but not in GC-6Spg. Moreover, after 6 h of treatment, intracellular reduced glutathione levels decrease significantly in Ser-W3 cells. These results show that doxorubicin induces oxidative stress in the Ser-W3 cell line. However, a depletion in glutathione does not affect their survival, and supplementation only offers a weak protection after exposure to doxorubicin, suggesting that the glutathione system is not essential for Ser-W3 cell line's defense against doxorubicin. On the other hand, among four antioxidants selected from the literature, none reduces the cytotoxicity of doxorubicin in Ser-W3 cells. Together, our data suggest that oxidative stress may not be a major pathway for doxorubicin's cytotoxicity in GC-6Spg and Ser-W3 lines. This study provides new insights in the mechanisms by which chemotherapies affect the pre-pubertal testis, with the long-term goal to help improve the quality of life of pediatric cancer survivors.

Silica nanoparticle exposure inducing granulosa cell apoptosis and follicular atresia in female Balb/c mice

Given that the effects of ultrafine fractions (< 0.1 μm) on reproductive diseases are gaining attention, this study aimed to explore the influence of silica nanoparticle (SiNP)-induced female reproductive dysfunction. In this study, 80 female mice were randomly divided into four groups including a control group and three concentrations of SiNP groups (7, 21, 35 mg/kg). Mice were exposed to the vehicle control and silica nanoparticles by tracheal perfusion every 3 days a total of five times in 15 days. Then, half of the mice in each group were sacrificed on 15 and 30 days after the first dose, respectively. Our findings indicated that SiNPs can result in ovarian damage, cause an imbalance of sex hormones, increase the number of atretic and primary follicles, and induce oxidative stress and DNA strand breaks in ovary by day 15. The protein expressions of ATM, CHK-2, P53, E2F1, P73, BAX, Caspase-9, and Caspase-3 were significantly increased, while expressions of RAD51 were down-regulated after SiNP exposure by days 15. Estradiol increased, while progesterone increased in low dose and decreased in high dose after SiNP exposure by 15 days. However, these changes were recovered by 30 days. The results suggest that SiNPs can cause reversible damage to follicles in mice. SiNPs could primarily cause DNA damage and DNA damage response through oxidative stress, while DNA damage repair failure because of severe DNA damage activated the mitochondrial apoptosis pathway and therefore resulted in apoptosis of granulosa cell. In addition, the disorder of reproductive endocrine function caused by SiNPs could be another reason for SiNP-induced reproductive dysfunction in mice. These events in turn induce the follicles to undergo atresia.

A morphological and biochemical evaluation of the effects of quercetin on experimental sciatic nerve damage in rats

The present study evaluated the neuroprotective and antioxidant effects of quercetin in a rat model of sciatic nerve crush injury using histopathological, morphometric and biochemical methods. A total of 48 male Sprague Dawley rats, aged 10-12 weeks old were randomly divided into eight groups, consisting of two sham groups (S-7, S-28), three quercetin-treated groups (Q-7, Q-28; 200 mg/kg/7 days), trauma (T-7, T-28; 1 min sciatic nerve crush injury) and three trauma+quercetin groups (T+Q-7, T+Q-28; trauma+quercetin 200 mg/kg/7 days). Rats were sacrificed on day 7 or 28. Oxidant-antioxidant biochemical parameters in nerve tissues from all groups were analyzed using histopathological staining with toluidine blue and Masson's trichrome. DNA fragmentations were identified using terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling in cells from each tissue sample. Degeneration of the axons and myelin sheath, the breakdown of the concentric lamellar structure of the myelin sheath and axonal swelling were observed in groups T-7 and T-28. Myelin sheath thicknesses, nerve fiber diameters and the number of myelinated nerve fibers decreased, while the apoptotic index (AI) increased in the T-7 and T-28 groups. However, it was observed that nerve regeneration began in the T+Q-7 and T+Q-28 groups compared with the sham groups, together with the healing of cellular damage and axonal structure and a decrease in the AI. Malondialdehyde and superoxide dismutase activity did not differ significantly between the T-7 and S-7 groups. However, catalase activity significantly decreased in the T-28 group when compared with the sham 7 day group. Tissue malondialdehyde levels significantly increased, while serum catalase activity increased in the T+Q-7 group compared with the T-7 group. These results suggest that quercetin has beneficial effects on nerve regeneration and may shorten the healing period in crush-type sciatic nerve injuries.

Histomorphometric evaluation of mice testicular tissue following short- and long-term effects of lipopolysaccharide-induced endotoxemia

Objective(s)::

Lipopolysaccharide (LPS)-induced endotoxemia is known to cause male infertility. This study was designed to explore the effects of bacterial LPS on histomorphometric changes of mice testicular tissues.

Materials and Methods:

In experiment 1, a pilot dose responsive study was performed with mice that were divided into five groups, receiving 36000, 18000, 9000, and 6750 µg/kg body weight (B.W) of LPS or only saline (control). White blood cells (WBC) were observed for 3 days after LPS inoculation. In experiment 2, two groups of mice were treated with 6750 µg/kg B.W of LPS or only saline (control). Five cases from each experimental group were sacrificed at 3, 30, and 60 days after LPS inoculation. Left testes were fixed in Bouin’s solution, and stained for morphometrical assays.

Results:

Time-course changes of WBC obtained from different doses of LPS-treated mice showed that inoculation of 6750 µg/kg B.W produced a reversible endotoxemia that lasts for 72 hr and so it was used in the second experiment. In experiment 2, during the first 3 days, no significant changes were observed in the evaluated parameters instead of seminiferous tubules diameter. Spermatogenesis, Johnsen’s score, meiotic index, and epithelial height were significantly affected at 30^th day. However, complete recovery was only observed for the spermatogenesis at day 60. Interestingly, deleterious effects of LPS on spermatogonia were only seen at 60^th day (P<0.05).

Conclusion:

Endotoxemia induced by LPS has long-term detrimental effects on spermatogonia and later stage germ cells, which are reversible at the next spermatogenic cycle.

Biochemical and pathological changes in the male rat kidney and bladder following exposure to continuous 900-MHz electromagnetic field on postnatal days 22-59<sup/>

PURPOSE

To investigate the effect on male rat kidney and bladder tissues of exposure to 900-megahertz (MHz) electromagnetic field (EMF) applied on postnatal days 22-59, inclusive.

MATERIALS AND METHODS

Twenty-four male Sprague Dawley rats, aged 21 days, were used. These were divided equally into one of three groups, control (CG), sham (SG) or EMF (EMFG). CG was not exposed to any procedure. SG rats were kept inside a cage, without being exposed to the effect of EMF, for 1 h a day on postnatal days 22-59, inclusive. EMFG rats were exposed to continuous 900-MHz EMF for 1 h a day under the same conditions as those for the SG rats. Rats were sacrificed on postnatal day 60, and the kidney and bladder tissues were removed. Tissues were stained with hematoxylin and eosin (H&E) and Masson trichrome for histomorphological evaluation. The TUNEL method was used to assess apoptosis. Transmission electron microscopy (TEM) was also used for the kidney tissue. Oxidant/antioxidant parameters were studied in terms of biochemical values.

RESULTS

The findings showed that tissue malondialdehyde increased in EMFG compared to CG and SG in both kidney (p = 0.004 and p = 0.004, respectively) and bladder tissue (p = 0.004, p = 0.006, respectively), while catalase and glutathione levels decreased compared to CG (p = 0.004; p = 0.004, respectively) and SG (p = 0.004; p = 0.004, respectively). In the EMF group, pathologies such as dilatation and vacuolization in the distal and proximal tubules, degeneration in glomeruli and an increase in cells tending to apoptosis were observed in kidney tissue. In bladder tissue, degeneration in the transitional epithelium and stromal irregularity and an increase in cells tending to apoptosis were observed in EMFG. Additionally, EMFG samples exhibited glomerular capillary degeneration with capillary basement membranes under TEM.

CONCLUSIONS

We conclude that continuous exposure to the effect of 900-MHz EMF for 1 h a day on postnatal days 22-59, inclusive, causes an increase in oxidative stress and various pathological changes in male rat kidney and bladder tissues.