Spermatogenesis recovery in the mouse after iron injury

Chlorocholine chloride exposure induced spermatogenic dysfunction via iron overload caused by AhR/PERK axis-dependent ferritinophagy activation

Chlorocholine chloride (CCC) is a plant growth regulator used worldwide that is detectable in cereals, fruits and animal products. The health effects of CCC exposure have raised public concern. Our previous research showed that CCC exposure decreased testosterone synthesis in pubertal rats. However, little is known about whether and how pubertal CCC exposure impacts spermatogenesis. In this study, we used BALB/c mice and spermatogonia-derived GC-1 cells to examine CCC-induced spermatogenic dysfunction. In vivo, pubertal CCC exposure led to decreased testicular weight, decreased testicular germ cells and poor sperm quality. This effect worsened after cessation of CCC exposure for the next 30 days. RNA-seq and western blot analysis revealed that CCC induced aryl hydrocarbon receptor (AhR) signaling, endoplasmic reticulum stress (ERS) and ferritinophagy. Increased iron content and lipid peroxidation levels were also observed in CCC-treated testes. In vitro, it was identified that iron overload mediated by enhanced ferritinophagy occurred in CCC-treated GC-1 cells, which might be attributed to the PERK pathway in ERS. Further, for the first time, our study elucidated the involvement of AhR in CCC-induced iron overload, which aggravated testicular oxidative damage via lipid peroxidation. Considering the adverse impact of CCC exposure on rodents, supportive evidence from GC-1 cells, and the critical importance of spermatogenesis on male development, the effects of CCC on the male reproduction warrant increased attention.

Relation of seminal plasma trace mineral in the Arabian stallion's semen with the semen characteristics and subsequent fertility

Background

Seminal plasma contains several microelements like Zn, Fe, Se, and Cu that affect sperm motility and male fertility. Biochemical evaluation of seminal plasma trace elements is important for assessing fertility and diagnosing male infertility.

Aims

The present study was designed to evaluate the effect of seminal fluid trace elements on sperm parameters and fertility in Arabian horses.

Methods

Ninety-four ejaculates from 25 Arabian stallions (4–27 years old) were used to investigate the effect of seminal fluid trace elements on semen parameters and fertility. Data divided according to season, stallion age, and fertility of stallions. The concentrations of Zn, Fe, Se, Cu, Cr and Mo were determined using an atomic absorption spectrophotometer. Percentage stallion fertility estimated by mares that conceived on their first cycle. Data were analyzed by ANOVA using SPSS statistical software program (2013), version 22.0.

Results

There was a significant effect of season on semen volume, pH, Fe, Se, Cu, Cr, and Mo. Stallion age had a significant effect on pH, sperm motility, concentration, total motile sperm count, sperm abnormalities, Zn, and Fe. Sperm motility was higher (P < 0.05) and sperm abnormalities were lower (P < 0.05) in group IV (>70% fertility) than in group I (infertile) and group II (<50% fertility). Sperm abnormalities were low in group IV and high in groups I and II. Seminal plasma Zn and Cu levels were higher (P < 0.05) in groups III (50_70% fertility) and IV than in group I. Fe levels were lower (P < 0.05) in group IV than in groups I, II, and III. Seminal plasma Mo concentrations were higher (P < 0.05) in group III than in group I.

Conclusions

High seminal plasma concentrations of Zn, Se, Cu, and Mo and low Fe concentrations are associated with improved stallions' semen parameters and fertility.

In vitro effect of ferrous sulphate on bovine spermatozoa motility parameters, viability and Annexin V-labeled membrane changes

The aim of this study was to assess the dose- and time-dependent in vitro effects of ferrous sulphate (FeSO₄.7H₂O) on the motility parameters, viability, structural and functional activity of bovine spermatozoa. Spermatozoa motility parameters were determined after exposure to concentrations (3.90, 7.80, 15.60, 31.20, 62.50, 125, 250, 500 and 1000 μM) of FeSO₄.7H₂O using the SpermVision^TM CASA (Computer Assisted Semen Analyzer) system in different time periods. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, and the Annexin V-Fluos was applied to detect the membrane integrity of spermatozoa. The initial spermatozoa motility showed increased average values at all experimental concentrations compared to the control group (culture medium without FeSO₄.7H₂O). After 2 h, FeSO₄.7H₂O stimulated the overall percentage of spermatozoa motility at the concentrations of ≤ 125 μM. However, experimental administration of 250 μM of FeSO₄.7H₂O significantly (P < 0.001) decreased the spermatozoa motility but had no negative effect on the cell viability (P < 0.05) (Time 2 h). The lowest viability was noted after the addition of ≥ 500 μM of FeSO₄.7H₂O (P < 0.001). The concentrations of ≤ 62.50 μM of FeSO₄.7H₂O markedly stimulated (P < 0.001) spermatozoa activity after 24 h of exposure, while at high concentrations of ≥ 500 μM of FeSO₄.7H₂O the overall percentage of spermatozoa motility was significantly inhibited (P < 0.001) and it elicited cytotoxic action. Fluorescence analysis confirmed that spermatozoa incubated with higher concentrations (≥ 500 μM) of FeSO₄.7H₂O displayed apoptotic changes, as detected in head membrane (acrosomal part) and mitochondrial portion of spermatozoa. Moreover, the highest concentration and the longest time of exposure (1000 μM of FeSO₄.7H₂O; Time 6 h) induced even necrotic alterations to spermatozoa. These results suggest that high concentrations of FeSO₄.7H₂O are able to induce toxic effects on the structure and function of spermatozoa, while low concentrations may have the positive effect on the fertilization potential of spermatozoa.

Effect of Fe and Cd Co-Exposure on Testicular Steroid Metabolism, Morphometry, and Spermatogenesis in Mice

The mechanism of testicular toxicity of simultaneous multiple exposures to metals is poorly understood. Previous studies reported that the toxic effect of cadmium (Cd) is modified by tissue concentration of iron (Fe). Using the mice (Mus musculus) model in the present study, we demonstrated that combined Cd (25 mg kg^-1 bw) and Fe (100 mg kg^-1 bw) treatment increased both Cd and Fe testicular concentrations much more than separate exposures to either of the metals. Intratesticular Cd and Fe concentrations were inversely correlated (r = - 0.731, p < 0.05) on administration of Fe but not on combined exposure to both metals when they were positively correlated (versus Cd; r = 0.793, versus Fe; r = 0.779, p < 0.05). Additionally, Cd + Fe treatment increased testicular lipid peroxidation and depleted intratestesticular testosterone, cholesterol and glutathione concentrations much more than their separate treatment. This was also associated with decreased activity of the germ cell marker, testicular lactate dehydrogenase, and increased testicular myeloperoxidase activity. These changes resulted in decreased seminiferous epithelial height, tubular diameter, germ cell (spermatogonia, spermatocytes, and spermatids) numbers, and severe tissue damage. In conclusion, Cd + Fe intake have synergistic toxic effects on testicular steroid formation and spermatogenesis due to the high testicular concentrations of both metals.

The relationship between seminal plasma and serum trace elements and semen parameters of dromedary camels (Camelus dromedarius)

A total of 14 camels of known fertility (controls) at the Camel Research Centre, King Faisal University and 41 infertile dromedaries brought to the Veterinary Teaching Hospital were used in this study during the breeding season. Seminal plasma and serum were obtained from all males, and stored at -80°C until analysis. Concentrations of six trace elements (manganese [Mn], zinc [Zn], iron [Fe], selenium [Se], copper [Cu] and chromium [Cr]) were estimated in the seminal plasma and serum using an atomic absorption spectrophotometer. Results showed significant (p < 0.05 and p < 0.01) differences in semen pH and sperm motility, concentration and abnormalities between the control and infertile dromedaries. In seminal plasma, a significant (p < 0.01) difference in Fe concentrations (7.792 ± 1.567 vs. 61.259 ± 11.967 mg/L) and significant (p < 0.05) differences in Zn (24.763 ± 8.206 vs. 83.981 ± 4.972 mg/L) and Cu (1.653 ± 0.348 vs. 7.905 ± 1.134 mg/L) concentrations existed between the control and infertile dromedaries, respectively. In serum, there were significant (p < 0.05) differences in Fe (6.237 ± 0.695 vs. 151.121 ± 27.604 mg/L) and Cu (24.703 ± 4.195 vs. 6.375 ± 0.644 mg/L) concentrations and a significant (p < 0.01) difference in Zn concentrations (17.086 ± 1.606 vs. 90.422 ± 4.347 mg/L) between the fertile and infertile camels, respectively. There were significant (p < 0.05) positive (r = 0.51) and negative (r = -0.54) correlations between Zn concentrations in seminal plasma and both sperm motility and sperm abnormalities, respectively. In conclusion, seminal plasma and serum trace elements of Fe, Zn and Cu influenced the semen parameters and fertility of dromedary camels. Low concentrations of Fe, Zn and Cu in the seminal plasma were associated with normal fertility in dromedaries.

Dose- and Time-Dependent In Vitro Effects of Divalent and Trivalent Iron on the Activity of Bovine Spermatozoa

This in vitro study was designed to assess the impact of divalent (Fe(2+)) or trivalent (Fe(3+)) iron on the activity and oxidative balance of bovine spermatozoa at specific time intervals (0, 2, 8, 16, and 24 h) during an in vitro culture. Forty-five semen samples were collected from adult breeding bulls and diluted in physiological saline solution supplemented with different concentrations (0, 1, 5, 10, 50, 100, 200, 500, 1000 μmol/L) of FeCl2 or FeCl3. Spermatozoa motion parameters were assessed using the SpermVision™ computer-aided sperm analysis (CASA) system. Cell viability was examined with the metabolic activity 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the nitroblue-tetrazolium (NBT) test was applied to quantify the intracellular superoxide formation. Both divalent and trivalent iron exhibited a dose- and time-dependent impact on the spermatozoa physiology and oxidative balance. Concentrations ≥50 μmol/L FeCl2 and ≥100 μmol/L FeCl3 led to a significant decrease of spermatozoa motility (P < 0.05) and mitochondrial activity (P < 0.001 with respect to 200-1000 μmol/L FeCl2/FeCl3; P < 0.01 in case of 100 μmol/L FeCl2/FeCl3), accompanied by a significant superoxide overproduction (P < 0.001 in terms of 200-1000 μmol/L FeCl2 and 500-1000 μmol/L FeCl3; P < 0.01 with respect to 100 μmol/L FeCl2 and 100-200 μmol/L FeCl3). On the other hand, concentrations below 10 μmol/L FeCl2 and 50 μmol/L FeCl3 proved to stimulate the spermatozoa activity, as shown by a significant preservation of the motility and viability characteristics (P < 0.001 in case of the motility parameters; P < 0.01 with respect to the spermatozoa viability), alongside a significant decline of the superoxide generation (P < 0.05). In a direct comparison, divalent iron has been shown to be more toxic than trivalent iron. Results from this in vitro study show that high concentrations of both forms of iron are toxic, while their low concentrations may have spermatozoa activity-promoting properties. In vitro concentrations of divalent or trivalent iron that could be regarded as critical are 50 μmol/L FeCl2 and 100 μmol/L FeCl3 when iron ceases to be an essential micronutrient in order to become a toxic risk factor.

Iron and copper in male reproduction: a double-edged sword

Iron and copper are essential trace nutrients playing important roles in general health and fertility. However, both elements are highly toxic when accumulating in large quantities. Their direct or indirect impact on the structure and function of male gonads and gametes is not completely understood yet. Excess or deficiency of either element may lead to defective spermatogenesis, reduced libido, and oxidative damage to the testicular tissue and spermatozoa, ultimately leading to fertility impairment. This review will detail the complex information currently available on the dual roles iron and copper play in male reproduction.