Lutein modulates transcription dysregulation of adhesion molecules and spermatogenesis transcription factors induced by testicular ischemia reperfusion injury: it could be SAFE

Novel Aspects of cAMP-Response Element Modulator (CREM) Role in Spermatogenesis and Male Fertility

Spermatogenesis is a very complex process with an intricate transcriptional regulation. The transition from the diploid to the haploid state requires the involvement of specialized genes in meiosis, among other specific functions for the formation of the spermatozoon. The transcription factor cAMP-response element modulator (CREM) is a key modulator that triggers the differentiation of the germ cell into the spermatozoon through the modification of gene expression. CREM has multiple repressor and activator isoforms whose expression is tissue-cell-type specific and tightly regulated by various factors at the transcriptional, post-transcriptional and post-translational level. The activator isoform CREMτ controls the expression of several relevant genes in post-meiotic stages of spermatogenesis. In addition, exposure to xenobiotics negatively affects CREMτ expression, which is linked to male infertility. On the other hand, antioxidants could have a positive effect on CREMτ expression and improve sperm parameters in idiopathically infertile men. Therefore, CREM expression could be used as a biomarker to detect and even counteract male infertility. This review examines the importance of CREM as a transcription factor for sperm production and its relevance in male fertility, infertility and the response to environmental xenobiotics that may affect CREMτ expression and the downstream regulation that alters male fertility. Also, some health disorders in which CREM expression is altered are discussed.

Trans-ferulic acid ameliorates cisplatin-induced testicular damage via suppression of TLR4, P38-MAPK, and ERK1/2 signaling pathways

Testicular damage has been described as a common side effect of cisplatin (CDDP), which limits its clinical uses. Since oxidative injury and inflammatory response are the most pathological impact, estimation of natural antioxidant and anti-inflammatory agents like trans-ferulic acid (TFA) could protect against CDDP-induced testicular damage. In the current investigation, rats were assigned into four groups: normal, TFA (50 mg/kg/day, P.O), CDDP (10 mg/kg) as single intraperitoneal (I.P) injection at the end of the 5th day, and TFA+CDDP where TFA was administered 5 days before CDDP injection and 5 days after. Interestingly, TFA significantly restored testosterone levels and abrogated oxidative stress injury. Additionally, TFA effectively suppressed inflammatory cytokines. It also counteracted the inflammation via downregulation of TLR4 and IRF3, P38-MAPK, NF-κB-p65, JAK1, STAT3, ERK1, and ERK2. Besides, TFA can modulate AKT and p-AKT protein expressions. In parallel, TFA mitigated the histopathological aberration of the testis and prevented spermatogenesis disruption. On the other hand, TFA augmented the in vitro CDDP cytotoxicity on Caco-2 and MCF-7 cells. Interestingly, TFA enhanced the cytotoxic effect of CDDP via apoptosis induction in both the early and late stages of apoptosis. Collectively, TFA exhibited a potential protective effect against CDDP-induced testicular injury by inhibiting oxidative stress as well as TLR4/IRF3/INF-γ, P38-MAPK/NF-κB-p65/TNF-α, and JAK1/STAT-3/ERK1/2 inflammatory signaling pathways with enhancing its in vitro cytotoxic activity.

The effects of broccoli and caraway extracts on serum oxidative markers, testicular structure and function, and sperm quality before and after sperm cryopreservation

Despite studies on the effects of medicinal plants on reproductive performance, the effect of extracts broccoli and caraway on serum and testicular oxidative biomarkers, testicular structure and function and sperm quality before and after cryopreservation has not been studied. Sixty-three male mice were divided into nine controlled and treated groups as follow: control, broccoli (200 mg/kg), broccoli (300 mg/kg), caraway (200 mg/kg), caraway (300 mg/kg), broccoli -caraway (200 mg/kg), broccoli (300 mg/kg)-caraway (200 mg/kg), broccoli (200 mg/kg)-caraway (300 mg/kg), broccoli-caraway (300 mg/kg). After 42 days of treatment, the animals were sacrificed and blood sample and testicular tissue were collected for biochemical and histological measurements. Sperm quality was also measured before and after cryopreservation. The results showed that the diameter and number of spermatogonium, primary spermatocytes, spermatids and sperm count were significantly increased by broccoli (300 mg/kg), while level of them were significantly decreased by caraway (300 mg/kg) compared to other groups (p < 0.01). Sperm viability and motility after thawing significantly improved by broccoli (300 mg/kg) compared to control. Testosterone levels significantly increased by broccoli (300 mg/kg) compared to control and caraway (300 mg/kg). The serum and testicular SOD and CAT activity significantly increased by broccoli (300 mg/kg) compared to other groups (p < 0.05). MDA and DNA fragmentation levels significantly increased by caraway (200 and 300 mg/kg) compared to others (p < 0.01). It can be concluded that broccoli extract in a dose-dependent manner than caraway extract could improve serum and testes oxidative biomarkers, testicular structure and function, and sperm quality before and after cryopreservation.

Sesamol Protects Testis from Ischemia-Reperfusion Injury through Scavenging Reactive Oxygen Species and Upregulating CREMτ Expression

Testicular torsion/detorsion-induced damage is considered as a typical ischemia-reperfusion injury attributed to excessive reactive oxygen species (ROS) production. ROS may regulate many genes whose expression affects cell-cycle regulation, cell proliferation, and apoptosis. The cAMP-responsive element modulator-τ (CREMτ) gene expression in the testis is essential for normal germ cell differentiation. The present study was aimed at investigating the effect of sesamol, a powerful antioxidant, on testicular ischemia-reperfusion injury and related mechanisms in an experimental testicular torsion-detorsion rat model. The type of our study was a randomized controlled trial. Sixty rats were randomly divided into the following 3 groups: (1) sham-operated control group (n = 20), (2) testicular ischemia-reperfusion group (n = 20), and (3) testicular ischemia-reperfusion+sesamol-treated group (n = 20). Testicular ischemia-reperfusion was induced by left testicular torsion (720° rotation in a counterclockwise direction) for 2 hours, followed by detorsion. Orchiectomy was performed at 4 hours or 3 months after detorsion. The testis was obtained for the analysis of the following parameters, including malondialdehyde level (a sensitive indicator of ROS), CREMτ expression, and spermatogenesis. In the testicular ischemia-reperfusion group, the malondialdehyde level was significantly increased with a concomitant significant decrease in CREMτ expression and spermatogenesis in ipsilateral testis. These results suggest that overproduction of ROS after testicular ischemia-reperfusion may downregulate CREMτ expression, which causes spermatogenic injury. Sesamol treatment resulted in a significant reduction in the malondialdehyde level and significant increase in CREMτ expression and spermatogenesis in ipsilateral testis. These data support the above suggestion. Our study shows that sesamol can attenuate testicular ischemia-reperfusion injury through scavenging ROS and upregulating CREMτ expression.

Sulphur dioxide and arsenic affect male reproduction via interfering with spermatogenesis in mice

As two potential environmental hazards, sulphur dioxide (SO₂) and arsenic have adverse effects on male reproduction, but the mechanism of which and their combined toxicity are not clear. In this study, we investigate male reproductive toxicity with a focus on spermatogenesis by treating mice with 5 mg/m³ SO₂ and/or 5 mg/L arsenic. Our results showed that arsenic exposure caused significant decreases in water and food consumption and body weight in mice, whereas these changes were not observed in the SO₂-only group. Both SO₂ and arsenic reduced sperm counts, increased the percentage of sperm malformation, and induced abnormal testicular pathological changes. Elevated H₂O₂ and MDA contents, declined T-SOD activity, decreased spermatogenic cell counts, enhanced caspase-3 activity, and increased TUNEL-positive cells were also observed in mice exposed to SO₂ and/or arsenic. Moreover, SO₂ and arsenic co-exposure changed the mRNA levels of Bax and Bcl-2, decreased serum testosterone levels, and downregulated the expression of steroidogenic-related genes (LHR, StAR, and ABP) in mice. These findings provide a new theoretical basis for understanding how SO₂ and arsenic interfere with spermatogenesis leading to infertility. These results also suggest that SO₂ and arsenic co-exposure likely result in an additive effect on male reproductive toxicity in mice.

Testicular compartment syndrome: an overview of pathophysiology, etiology, evaluation, and management

Testicular compartment syndrome (TCS) refers to the impairment of microcirculation in the testicle due to either increased venous resistance or extraluminal compression, which leads to hypoxia. TCS releases oxidants through hypoxia and ischemia/reperfusion injury (IRI). The pathophysiology, etiology, evaluation, and management of TCS are reviewed. Based on the properties of TCS, specific causes, e.g., varicocele, hydrocele, orchitis, cryptorchidism, and scrotal hernia, are suggested and categorized. The oxidant-induced stress from TCS may explain the correlations between these causes and infertility. A chief shortcoming of current imaging modalities is that they detect TCS late after it has progressed to impair the macrocirculation of the testicle. We propose frequent sequential periodic power Doppler ultrasonography to monitoring for earlier detection. Intraoperatively, TCS can be diagnosed by the dull purple appearance of a hypoxic testicle and by tissue pressures above 30 mmHg. When compartment pressure is low, the underlying etiology must be promptly treated. During acute presentation, an incision of the resilient tunica albuginea may be necessary. A great challenge of treating TCS is restoring microcirculation while minimizing IRI; concomitant antioxidant therapy secondary to treatment may be effective and harmless at the least. Because testicular oxidant stress is common in infertility and since TCS can cause such a stress, TCS may be a larger factor in infertility than currently suspected.

Sulfur dioxide inhalation lowers sperm quality and alters testicular histology via increasing expression of CREM and ACT proteins in rat testes

Sulfur dioxide (SO₂) is one of the main atmospheric pollutants worldwide, and is reported to be responsible for the formation of severe haze in China. Some studies have demonstrated a potential harmful effect of SO₂ on the male reproductive system; however the underlying mechanism is still unknown. The purpose of this study is to investigate the roles of cytochrome P450 (P450), cAMP-responsive element modulator (CREM), and activator of CREM (ACT) in SO₂-induced toxicity. Forty-eight male Wistar rats were randomly divided into an experimental and control group. The experiment group was exposed to SO₂ in ambient air (10ppm, 4h/day), and the control group was treated with filtered air in the same conditions. After 2 weeks, the results showed a significant decrease in body weight and sperm motility, and an increase in the testis weight-to-body weight ratio as compared to the control group. Histological investigation suggested that SO₂ exposure led to loose arrangement of the spermatogenic cells and local structural damage in the seminiferous tubules. Moreover, the expressions of P450, CREM and ACT proteins increased in the testes by 0.22%, 47.26% and 23.38%, respectively. Taken together, SO₂ inhalation lowered sperm quality, altered testicular histology, and increased expressions of CREM and ACT proteins in the testes of rats. Overall, these results could contribute to a better understanding of SO₂-induced male reproductive toxicity.