Effect of testicular ischemia-reperfusion on recruitment of neutrophils, E-selectin expression and germ cell apoptosis in the contralateral testis in a rat

The changing landscape of immune cells in the fetal mouse testis

Fetal testis growth involves cell influx and extensive remodeling. Immediately after sex determination in mouse, macrophages enable normal cord formation and removal of inappropriately positioned cells. This study provides new information about macrophages and other immune cells after cord formation in fetal testes, including their density, distribution, and close cellular contacts. C57BL6J mouse testes from embryonic day (E) 13.5 to birth (post-natal day 0; PND0), were examined using immunofluorescence, immunohistochemistry, and RT-qPCR to identify macrophages (F4/80, CD206, MHCII), T cells (CD3), granulocytes/neutrophils (Ly6G), and germ cells (DDX4). F4/80⁺ cells were the most abundant, comprising 90% of CD45⁺ cells at E13.5 and declining to 65% at PND0. Changes in size, shape, and markers (CD206 and MHCII) documented during this interval align with the understanding that F4/80⁺ cells have different origins during embryonic life. CD3⁺ cells and F4/80⁻/MHCII⁺ were absent to rare until PND0. Ly6G⁺ cells were scarce at E13.5 but increased robustly by PND0 to represent half of the CD45⁺ cells. These immunofluorescence data were in accord with transcript analysis, which showed that immune marker mRNAs increased with testis age. F4/80⁺ and Ly6G⁺ cells were frequently inside cords adjacent to germ cells at E13.5 and E15.5. F4/80⁺ cells were often in clusters next to other immune cells. Macrophages inside cords at E13.5 and E15.5 (F4/80^Hi/CD206⁺) were different from macrophages at PND0 (F4/80^Dim/CD206⁻), indicating that they have distinct origins. This histological quantification coupled with transcript information identifies new cellular interactions for immune cells in fetal testis morphogenesis, and highlights new avenues for studies of their functional significance.

Protective effect of pterostilbene on testicular ischemia/reperfusion injury in rats

PURPOSE

To evaluate protective effect of pterostilbene against testicular ischemia/reperfusion (I/R) injury, which results in increased formation of oxidative stress, leading to testicular apoptosis and impaired spermatogenesis.

METHODS

Thirty two pubertal male Sprague-Dawley rats weighing 180-220g were selected and randomly divided into the following four groups: group A (normal control group), group B (sham-operated group), group C (induced I/R injury group), group D (induced I/R injury group receiving pterostilbene treatment). Johnsen's scores and mean seminiferous tubule diameters were evaluated for histopathologic assessment; germinal cell apoptosis was evaluated by the transferase dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspases. Malondialdehyde (MDA) levels were assessed as an indicator of oxidative stress and total antioxidant capacity (TAC) was measured.

RESULTS

Germ cell apoptosis and MDA level significantly increased whereas TAC significantly decreased in group C; moreover, abnormal morphology and impaired spermatogenesis were observed in group C. In contrast, treatment with pterostilbene inhibited lipid peroxidation and apoptosis induced by ROS and restored the antioxidant capacity in group D.

CONCLUSIONS

These results show that treatment with pterostilbene may be a promising therapy for testicular I/R injury.

The Role of the Immune Response in Chlamydia trachomatis Infection of the Male Genital Tract: A Double-Edged Sword

Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection in the world, with more than 100 million cases reported annually. While there have been extensive studies into the adverse effects that CT infection has on the female genital tract, and on the subsequent ability of these women to conceive, studies into the consequences on male fertility have been limited and controversial. This is in part due to the asymptomatic nature of the infection, where it is estimated that 50% of men with Chlamydia fail to show any symptoms. It is accepted, however, that acute and/or persistent CT infection is the causative agent for conditions such as urethritis, epididymitis, epididymo-orchitis, and potentially prostatitis. As with most infections, the immune system plays a fundamental role in the body’s attempts to eradicate the infection. The first and most important immune response to Chlamydia infection is a local one, whereby immune cells such as leukocytes are recruited to the site of infections, and subsequently secrete pro-inflammatory cytokines and chemokines such as interferon gamma. Immune cells also work to initiate and potentiate chronic inflammation through the production of reactive oxygen species (ROS), and the release of molecules with degradative properties including defensins, elastase, collagenase, cathespins, and lysozyme. This long-term inflammation can lead to cell proliferation (a possible precursor to cancer), tissue remodeling, and scarring, as well as being linked to the onset of autoimmune responses in genetically disposed individuals. This review will focus on the ability of the immune system to recognize and clear acute and persistent chlamydial infections in the male genital tract, and on the paradoxical damage that chronic inflammation resulting from the infection can cause on the reproductive health of the individual.

Hypoxia and spermatogenesis

This review mainly focuses on our understanding of spermatogenesis in physiological and pathological hypoxic condition. Real hypoxia is closely related to vascular changes and an increase in testicular temperature. Both induce a reduction in sperm count and can be related to the increase in germ cell apoptosis. On the other hand, change in the temperature, and oxygen levels in the microenvironment have influence on spermatogonial stem cell function and differentiation. The initial connection between hypoxia and a factor critical for stem cell maintenance is alteration in Oct-4 expression, and these data may be a useful strategy for modulating stem cell function. Unilateral testicular ischemia-induced cell death can be accompanied by an increase in germ cell apoptosis in the contralateral testis. The injury of contralateral testis following unilateral testicular damage is controversial, and it can contribute to the reduction in fertility.

Effect of P/E-selectin blockage on antisperm antibody development and histopathological alterations in experimental orchitis

AIM

This study aimed to evaluate the effect of P/E-selectin blockage on antisperm antibody (ASA) development and histopathological alterations in experimental orchitis.

MATERIALS AND METHODS

Thirty-six Wistar albino-type male rats weighing 100-150 g were included in the study. Rats were allocated into six groups (n = 6) including control (CG), sham (SG), orchitis (OG), antimicrobial treatment (AG), P/E-selectin blockage (PESG), and both antimicrobial and P/E-selectin treatment (TG) groups. In CG, serum samples were taken from the tail vein prior to the procedure and followed by extraction of both testes. In SG, 1 ml of saline solution was injected in testicular parenchyma. OG was obtained by injecting 0.1 ml 106 cfu/ml Escherichia coli (0:6 strain) and 1 ml saline solution into the right testes. AG received ciprofloxacin (50 mg/kg/day) twice a day through gastrogavage 24 hours after generating orchitis. In PESG, P/E-selectin antibody (100 μg) was administered intravenously via the tail vein 24 hours after the induction of orchitis. Finally, both ciprofloxacin and P/E-selectin antibody were administered in TG 24 hours after the induction of orchitis for 14 days. At the end of treatment, 1 ml of serum sample was obtained to evaluate the ASA, P-selectin and E-selectin levels. In order to evaluate spermatogenesis (Johnsen score) and testicular injury (Cosentino score), both testes were extracted at the end of the 14th day.

RESULTS

In orchitis-induced groups (OG, ATG, PSEG, TG), ASA levels were significantly increased at the 14th day when compared to SG (p < 0.05). In TG, ASA levels were decreased when compared to AG. However, similar alteration in ASA levels was not detected in PSEG (p > 0.05). In OG and AG, P-selectin levels were decreased at the 14th day when compared to levels observed on 0 day (p < 0.05). E-selectin levels on 0 day showed that each group had higher levels of E-selectin when compared to CG (p > 0.05). There was no significant difference regarding E-selectin when compared to CG (p > 0.05). No significant differences regarding E-selectin levels were detected on the 0th and 14th days between AG and CG (p > 0.05). When the Cosentino and Johnsen scores were compared among groups, TG and PSEG has decreased scores of Cosentino than OG on the right testicle (p < 0.05). In contrast, an increased Johnsen score was detected in TG and PSEG when compared to OG (p < 0/05). No significant difference was detected for both Cosentino and Johnsen scores on the left testicle (p > 0.05). There was no difference with regard to the right and left testicular injury in TG. In P/E-blocked groups, decreased histopathological alterations were observed in the contralateral testis.

CONCLUSION

P/E-selectin blockage may reduce ASA production after orchitis when combined with antimicrobial treatment. P/E-selectin blockage not only has a protective effect on blood-testis barrier but also decreases the histopathological alterations in both the affected and contralateral testis. Histopathological parameters of spermatogenesis may also be prevented by P/E-selectin blockage in experimental orchitis.

Endogenous EGF maintains Sertoli germ cell anchoring junction integrity and is required for early recovery from acute testicular ischemia/reperfusion injury

Administration of exogenous epidermal growth factor (EGF) improves testicular injury after acute ischemia–reperfusion (IR) stress, but the molecular basis is poorly understood. The role of endogenous EGF in testicular recovery and the underlying intracellular signaling pathways involved were herein investigated. In mice, testicular IR injury significantly enhanced the expression level of endogenousEgfat the very beginning of reperfusion. Expression of EGF receptor (Egfr(ErbB1)) was accordingly upregulated 3 h after reperfusion. Deprivation of majority of circulated EGF by sialoadenectomy aggravated testicular detriment (especially in pachytene spermatocytes), enhanced germ cell apoptosis, and thereafter resulted in impaired meiotic differentiation after IR insult. Mechanistically, endogenous EGF signaling appeared to be indispensable for the proper maintenance of Sertoli germ cells anchoring junction dynamics during the early testicular recovery. We also provided thein vitroevidences in a well-established rat Sertoli germ cell co-cultures model that the pro-survival effect of endogenous EGF on germ cells in response to testicular IR insult is mediated, at least in part, via the phosphatidylinositol 3-kinase/pAkt pathway. Collectively, our results suggest that the augment of endogenous EGF during the early testicular recovery may act on top of an endocrinous cascade orchestrating the intimate interactions between Sertoli cells and germ cells and may operate as indispensable defensive mechanism in response to testicular IR stress. Future studies in this field would shed light on this complicated pathogenesis.