Protective Effect of Administered Rolipram against Radiation-Induced Testicular Injury in Mice

Low dose rate radiation impairs early follicles in young mice

Low-dose radiation is generally considered less harmful than high-dose radiation. However, its impact on ovaries remains debated. Since previous reports predominantly employed low-dose radiation delivered at a high dose rate on the ovary, the effect of low-dose radiation at a low dose rate on the ovary remains unknown. We investigated the effect of low-dose ionizing radiation delivered at a low dose rate on murine ovaries. Three- and ten-week-old mice were exposed to 0.1 and 0.5 Gy of radiation at a rate of 6 mGy/h and monitored after 3 and 30 days. While neither body weight nor ovarian area showed significant changes, ovarian cells were damaged, showing apoptosis and a decrease in cell proliferation after exposure to 0.1 and 0.5 Gy radiation. Follicle numbers decreased over time in both age groups proportionally to the radiation dose. Younger mice were more susceptible to radiation damage, as evidenced by decreased follicles in 3-week-old mice after 30 days of 0.1 Gy exposure, while 10-week-old mice showed reduced follicles only following 0.5 Gy exposure. Primordial or primary follicles were the most vulnerable to radiation. These findings suggest that even low-dose radiation, delivered at a low dose rate, can adversely affect ovarian function, particularly in the early follicles of younger mice.

Protective effects of an aqueous extract of Protaetia brevitarsis seulensis larvae against radiation-induced testicular injury in mice

The larvae of Protaetia brevitarsis seulensis have been used as a food ingredient and are known for their nutritional value and anti-inflammatory properties. However, whether P. brevitarsis seulensis larvae demonstrate protective effects against radiation-induced testicular injury has not been investigated. In this study, the protective effects of an aqueous extract of P. brevitarsis seulensis larvae (PBE) against radiation-induced testicular injury were tested. Male C57BL/6 mice were administered PBE (5 or 10 mg/kg) orally for 14 days before exposure to focal pelvic irradiation. Histopathological examinations were conducted at 8 h and 30 d after radiation exposure. PBE pretreatment reduced the radiation-induced apoptosis of germ cells at 8 h after irradiation and significantly increased testis and epididymis weights relative to those of the irradiated control mice at 30 days. PBE protected against histopathological damage and decreased the radiation-induced effects on the epithelium height and seminiferous tubule diameter. Furthermore, the extract ameliorated the radiation-induced morphological abnormalities of sperm cells and improved their motility. It also prevented a decrease in the epididymal sperm count caused by irradiation. Moreover, the extract alleviated the generation of reactive oxygen species, and its antioxidative activity increased in a dose-dependent manner. Among the six major compounds isolated from PBE, benzoic acid and uridine showed the highest antioxidant activities. These results suggest that PBE protects against radiation-induced testicular injury via its antioxidative properties. Thus, it has potential clinical applicability as a neoadjuvant therapy for the prevention of testicular damage caused by cancer radiotherapy.

Differential Effects of Low and High Radiation Dose Rates on Mouse Spermatogenesis

The adverse effects of radiation are proportional to the total dose and dose rate. We aimed to investigate the effects of radiation dose rate on different organs in mice. The mice were subjected to low dose rate (LDR, ~3.4 mGy/h) and high dose rate (HDR, ~51 Gy/h) radiation. LDR radiation caused severe tissue toxicity, as observed in the histological analysis of testis. It adversely influenced sperm production, including sperm count and motility, and induced greater sperm abnormalities. The expression of markers of early stage spermatogonial stem cells, such as Plzf, c-Kit, and Oct4, decreased significantly after LDR irradiation, compared to that following exposure of HDR radiation, in qPCR analysis. The compositional ratios of all stages of spermatogonia and meiotic cells, except round spermatid, were considerably reduced by LDR in FACS analysis. Therefore, LDR radiation caused more adverse testicular damage than that by HDR radiation, contrary to the response observed in other organs. Therefore, the dose rate of radiation may have differential effects, depending on the organ; it is necessary to evaluate the effect of radiation in terms of radiation dose, dose rate, organ type, and other conditions.

Targeting CREB in Cancer Therapy: A Key Candidate or One of Many? An Update

Intratumor heterogeneity (ITH) is considered the major disorienting factor in cancer treatment. As a result of stochastic genetic and epigenetic alterations, the appearance of a branched evolutionary shape confers tumor plasticity, causing relapse and unfavorable clinical prognosis. The growing evidence in cancer discovery presents to us "the great paradox" consisting of countless potential targets constantly discovered and a small number of candidates being effective in human patients. Among these, cyclic-AMP response element-binding protein (CREB) has been proposed as proto-oncogene supporting tumor initiation, progression and metastasis. Overexpression and hyperactivation of CREB are frequently observed in cancer, whereas genetic and pharmacological CREB downregulation affects proliferation and apoptosis. Notably, the present review is designed to investigate the feasibility of targeting CREB in cancer therapy. In particular, starting with the latest CREB evidence in cancer pathophysiology, we evaluate the advancement state of CREB inhibitor design, including the histone lysine demethylases JMJD3/UTX inhibitor GSKJ4 that we newly identified as a promising CREB modulator in leukemia cells. Moreover, an accurate analysis of strengths and weaknesses is also conducted to figure out whether CREB can actually represent a therapeutic candidate or just one of the innumerable preclinical cancer targets.

Pelvic Radiation-Induced Testicular Damage: An Experimental Study at 1 Gray

Therapeutic radiation of the pelvic region has been shown to cause damage to testicular germ cells. In this study we aimed to evaluate the effects of a low therapeutic dose of 1 Gy on the induction of cellular and histological damage in early-stage testicular germ cells and the impact of this radiation on offspring sex ratio. Unirradiated and irradiated male rats were mated with unirradiated female rats. Female rats were followed and the sex of the offspring was determined. The male rats were sacrificed at the end of the second week, and the testicular germ cells were subjected to genetic analysis along with cytological and histopathological examination. Sperm DNA was amplified with primers specific to testis-specific Y-linked protein, rat actin beta and testis-specific X-linked genes. The resulting products were separated by capillary electrophoresis. Histopathological changes were investigated by light microscopy along with the TUNEL assay and immunohistochemical staining for caspase-3. There was no significant difference between the two groups for sex ratio and size of offspring. The number of sperm cells bearing X or Y chromosomes' did not differ significantly between these two groups. However, a 1 Gy dose of radiation caused significant cytopathological and histopathological changes in the testicular tissue. In the irradiated group, edematous regions were evident. The number of caspase-3 positive cells in the germinal epithelium of the seminiferous tubules was also significantly higher in the irradiated group. Our results showed that low-dose radiation induced apoptosis and caused significant cyto- and histopathological changes in the testicular tissue. Further research is required to fully elucidate their contribution to apoptosis and if low-dose radiation may potentially lead to long-term effects in the offspring. These results may also lead us to develop a new technique using the caspase-3 staining to monitor the susceptibility to low dose radiation.

Reduced Glycolysis Contributed to Inhibition of Testis Spermatogenesis in Rats After Chronic Methamphetamine Exposure

BACKGROUND Previous reports suggested that methamphetamine (METH) exposure could lead to inhibition of rat testis spermatogenesis. Glycolysis and glucose metabolism as well as oxidative stress have been implicated in testis spermatogenesis. Here we explored the underlying mechanism of local metabolism and glycolysis of testis after METH exposure. MATERIAL AND METHODS METH was intraperitoneally injected into rats with different doses and duration of METH exposure to establish short-term and chronic exposure models. The serum 8-hydroxy-2 deoxyguanosine (8-OHdG) level of rats was detected by enzyme-linked immunosorbent assay. Untargeted gas chromatography-mass spectrometry analysis was applied to identify differential metabolites and metabolic signature. The mRNA expression of hypoxia inducible factor 1alpha (HIF1alpha), glucose transporter 1 (GLUT1), hexokinase 1 (HK1) and lactate dehydrogenase C (LDHC) in rat testes were detected by polymerase chain reaction. Further, we determined the 4 proteins with western blotting and immunohistochemistry. RESULTS Decreased testes index and sperm counts were showed in the chronic METH group. The metabolome revealed that the main differential metabolites impacted were associated with glycolysis and glucose metabolism. The mRNA and protein expression of GLUT1, HK1, and LDHC were reduced in the chronic METH group but elevated in the short-term METH group, whereas HIF1alpha was upregulated in the short-term METH group but remained at baseline in the chronic METH group. CONCLUSIONS Overall, glucose metabolism was regulated by HIF1alpha after short-term METH exposure. Reduced glycolysis in the testis led to impaired spermatogenesis after chronic METH exposure.

Polydatin Alleviates Radiation-Induced Testes Injury by Scavenging ROS and Inhibiting Apoptosis Pathways

Background

Exposure to ionizing radiation (IR) induces severe damage in multiple human tissues. The testes are extremely sensitive to IR, and testes irradiation can result in infertility and abnormality. A novel and safe radioprotector for testes injury from IR is needed. Polydatin (PD) has been proved to have anti-oxidant and anti-inflammatory effects, indicating its potential application in radiation protection.

Material/Methods

Male wild-type C57BL/6 mice (8 weeks old) were exposed to ionizing radiation. At different times after irradiation, testes were isolated and subjected to hematoxylin-eosin (HE) staining and TUNEL staining, as well as related quantification. ELISA assay was used to measure the level of inflammatory cytokines, and apoptosis proteins were detected by Western blot assay. Intracellular ROS was measured by DCFH-DA flow cytometry method.

Results

In the present study, we demonstrated that polydatin effectively alleviated testes injury and retained sperm viability. PD pretreatment also inhibited cell apoptosis caused by irradiation. Radiation-induced decrease of FSH and testosterone was also inhibited by PD treatment. Finally, we showed that PD obviously reduced the ROS level, using DCFH-DA method. We also found that PD reduced the concentration of the oxidative products MDA and 8-OHdG. PD also inhibited apoptosis-related proteins such as Bax and caspase 3.

Conclusions

Our data proved that polydatin effectively alleviated testes injury after irradiation, mainly through reducing ROS and oxidative stress. Our findings suggest polydatin as a potential radioprotector for testes radiation damage.

Beneficial effects of rolipram, a phosphodiesterase 4 specific inhibitor, on testicular torsion-detorsion injury in rats

INTRODUCTION

The aim of the study is to investigate the effect of Rolipram, a selective phosphodiesterase 4 inhibitor, on testicular torsion - detorsion injury.

METHODS

Sixty young male rats were divided into five groups. In each group, the right testes of six rats were removed four hours after detorsion for biochemical analysis, and the right testes of the remaining six rats were removed 24 h after detorsion for pathological analysis. In group 1 (sham-operated) right orchiectomy was performed without torsion, and right testes were sent to the laboratory for biochemical and pathologic analyses. In group 2 (control) torsion was applied to the right testes for 60 min, and detorsion was performed without the administration of Rolipram. In group 3 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min before detorsion. In group 4 torsion was applied to the right testes for 60 min, and 1 mg/kg Rolipram was administered during detorsion. In group 5 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min after detorsion. The malondialdehyde and nitric oxide levels were determined. The rates of necrosis and apoptosis were evaluated by histopathological examination.

RESULTS

The level of malondialdehyde was higher in the torsioned groups (Group 2, 3, 4, 5) than that in group 1 (p = 0.004). There was no statistically significant difference between the groups regarding the level of nitric oxide (p = 0.182). Apoptosis was higher in groups 2, 3 and 4 than in group 1; however, apoptosis was similar in group 1 and group 5 (p = 0.122). The level of necrosis in group 1 was similar to that in groups 4 and 5 (p = 0.194 and p = 0.847, respectively).

CONCLUSION

We suggest that the administration of Rolipram can decrease the rate of necrosis and apoptosis in testicular ischaemia-reperfusion injury.

Nesfatin-1 ameliorates testicular injury and supports gonadal function in rats induced with testis torsion

Testicular torsion causes ischemia-reperfusion injury and an increased risk of infertility. Nesfatin-1 is a novel peptide with antioxidant, anti-inflammatory and anti-apoptotic properties. In the present study, we aimed to investigate the putative beneficial effects of nesfatin-1 on oxidative injury and impaired testicular function induced by testis torsion. Under anesthesia, male Sprague-Dawley rats (180-230 g; n = 24) had sham-operation or they underwent testicular torsion by rotating the left testis 720° and fixing it for 2 h, followed by a 2-h detorsion. Rats in each group were treated intraperitoneally with either nesfatin-1 (0.3 μg/kg) or saline prior to the torsion or sham-torsion. At the end of the 4-h experimental period, tissue samples were removed for evaluation of spermatozoa, molecular and histochemical analyses. In saline-treated torsion/detorsion group, a high percentage of abnormal spermatozoa with head defects was observed, which was abolished in nesfatin-1-treated torsion/detorsion group. The levels of 8-OHdG, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, caspase-3 were increased in the saline-treated torsion/detorsion group as compared to sham-operated group, while nesfatin-1 pre-treatment significantly decreased the expressions of the pro-inflammatory cytokines, depressed apoptosis, and also reduced the tubular degeneration. In addition, nesfatin-1 in torsion/detorsion group elevated expressions of transforming growth factor (TGF)-beta and reduced expressions of protein kinase B (AKT) and cAMP response element binding protein (CREB) in the testis tissue. The present findings show that nesfatin-1, by regulating AKT and CREB signaling pathways and pro-inflammatory/anti-inflammatory cytokine balance, preserves the spermatogenic cells and ameliorates torsion-detorsion-induced tubular degeneration.