scholarly journals Oxidative Stress, Testicular Inflammatory Pathways and Male Reproduction

2021 ◽  
Vol 22 (18) ◽  
pp. 10043
Author(s):  
Sulagna Dutta ◽  
Pallav Sengupta ◽  
Petr Slama ◽  
Shubhadeep Roychoudhury

Inflammation is among the core causatives of male infertility. Despite male infertility being a serious global issue, “bits and pieces” of its complex etiopathology still remain missing. During inflammation, levels of proinflammatory mediators in the male reproductive tract are greater than usual. According to epidemiological research, in numerous cases of male infertility, patients suffer from acute or chronic inflammation of the genitourinary tract which typically occurs without symptoms. Inflammatory responses in the male genital system are inextricably linked to oxidative stress (OS). OS is detrimental to male fertility parameters as it causes oxidative damage to reproductive cells and intracellular components. Multifarious male infertility causative factors pave the way for impairing male reproductive functions via the common mechanisms of OS and inflammation, both of which are interlinked pathophysiological processes, and the occurrence of any one of them induces the other. Both processes may be simultaneously found in the pathogenesis of male infertility. Thus, the present article aims to explain the role of inflammation and OS in male infertility in detail, as well as to show the mechanistic pathways that link causative factors of male reproductive tract inflammation, OS induction, and oxidant-sensitive cellular cascades leading to male infertility.

2021 ◽  
Author(s):  
Vegim Zhaku ◽  
Ashok Agarwal ◽  
Sheqibe Beadini ◽  
Ralf Henkel ◽  
Renata Finelli ◽  
...  

Within the male reproductive system, oxidative stress (OS) has been identified as prevailing etiology of male infertility. The effects of reactive oxygen species (ROS) on male fertility depend on the dimensions, “modus operandi” of the ROS and the oxido-reduction potential (ORP) of the male reproductive tract. Hereupon, for an adequate response to OS, the cells of our body are endowed with a well-sophisticated system of defense in order to be protected. Various antioxidant enzymes and small molecular free radical scavengers, maintain the delicate balance between oxidants and reductants (antioxidants), crucial to cellular function and fertility. Therapeutic use of antioxidants is an optimal and coherent option in terms of mitigating OS and improving semen parameters. Therefore, recognizing and managing OS through either decreasing ROS levels or by increasing antioxidant force, appear to be a requesting approach in the management of male infertility. However, a clear defined attitude of the experts about the clinical efficacy of antioxidant therapy is still deprived. Prominently, antioxidant such as coenzyme Q10, vitamin C and E, lycopene, carnitine, zinc and selenium have been found useful in controlling the balance between ROS production and scavenging activities. In spite of that, healthy lifestyle, without smoke and alcohol, everyday exercise, reduction of psychological stress and quality well-designed meals, are habits that can overturn male infertility.


Author(s):  
Nikolaos Sofikitis ◽  
Aris Kaltsas ◽  
Fotios Dimitriadis ◽  
Jens Rassweiler ◽  
Nikolaos Grivas ◽  
...  

The therapeutic range of cyclic nucleotide phosphodiesterase 5 inhibitors (PDE5) inhibitors is getting wider in the last years. This review study focuses on the potential employment of PDE5 inhibitors as an adjunct tool for the therapeutic management of male infertility. The literature tends to suggest a beneficial effect of PDE5 inhibitors on Leydig and Sertoli cells secretory function. It also appears that PDE5 inhibitors play a role in the regulation of the contractility of the testicular tunica albuginea and the epididymis. Moreover scientific data suggest that PDE5 inhibitors enhance the prostatic secretory function leading to an improvement in sperm motility. Other studies additionally demonstrate a role of PDE5 inhibitors in the regulation of sperm capacitation process. Placebo-controlled, randomized, blind studies are necessary to unambiguously incorporate PDE5 inhibitors as an adjunct tool for the pharmaceutical treatment of semen disorders and male infertility.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 134 ◽  
Author(s):  
Karolina Nowicka-Bauer ◽  
Brett Nixon

A state of oxidative stress (OS) and the presence of reactive oxygen species (ROS) in the male reproductive tract are strongly correlated with infertility. While physiological levels of ROS are necessary for normal sperm functioning, elevated ROS production can overwhelm the cell’s limited antioxidant defenses leading to dysfunction and loss of fertilizing potential. Among the deleterious pleiotropic impacts arising from OS, sperm motility appears to be particularly vulnerable. Here, we present a mechanistic account for how OS contributes to altered sperm motility profiles. In our model, it is suggested that the abundant polyunsaturated fatty acids (PUFAs) residing in the sperm membrane serve to sensitize the male germ cell to ROS attack by virtue of their ability to act as substrates for lipid peroxidation (LPO) cascades. Upon initiation, LPO leads to dramatic remodeling of the composition and biophysical properties of sperm membranes and, in the case of the mitochondria, this manifests in a dissipation of membrane potential, electron leakage, increased ROS production and reduced capacity for energy production. This situation is exacerbated by the production of cytotoxic LPO byproducts such as 4-hydroxynonenal, which dysregulate molecules associated with sperm bioenergetic pathways as well as the structural and signaling components of the motility apparatus. The impact of ROS also extends to lesions in the paternal genome, as is commonly seen in the defective spermatozoa of asthenozoospermic males. Concluding, the presence of OS in the male reproductive tract is strongly and positively correlated with reduced sperm motility and fertilizing potential, thus providing a rational target for the development of new therapeutic interventions.


Author(s):  
S. K. Bhure ◽  
P. Harikrishna ◽  
J. Usharani ◽  
A. M. Shende ◽  
S. Harikumar

Regucalcin is a multifunctional protein having an important role in calcium homeostasis, L-ascorbic acid biosynthesis, anti-prolific, anti-apoptotic functions as well as detoxification of chemical warfare nerve agents. Recently, it has been localized to male reproductive tract of rat and human, and identified as an androgen-target gene. The literature suggests a possible role of regucalcin in male fertility. However, no detailed studies have been conducted on its role in male reproductive organs of domestic animals. As an initial step, we had cloned and expressed regucalcin in Pichia pastoris. The sequence analysis showed 100% homology with regucalcin of Bos tours both at nucleotide and amino acid level. The SDS-PAGE and Western blot studies of recombinant protein probed with anti-regucalcin monoclonal antibody showed a higher molecular weight (56 kDa) than the expected (35.5 kDa) that could be due to hyperglycosylation. The recombinant regucalcin and its antibodies can be used to study the detailed role of the protein in male reproduction.


Author(s):  
Kushaan Khambata ◽  
Deepak Modi ◽  
Satish Gupta

The testis is designated as one of the immune previleged sites in the body and harbours a unique immunoregulatory environment, which is important for preventing an immune response against sperm antigens which otherwise are recognized as “foreign” by the immune system. The blood-testis barrier along with the unique immune cells repertoire and various immunoregulatory & immunosuppressive factors secreted by the Leydig cells, Sertoli cells and peritubular cells act in concert to maintain the tolerogenic environment in the testis. Abberations in immunotolerant mechanisms in the testis can lead to generation of anti-sperm antibodies that have an association with male infertility. It can also lead to inflammatory conditions of the male reproductive tract manifested as epididymitis and orchitis, generally due to bacterial or viral infections. In addition, non-infectious epididymitis and orchitis, having autoimmune origin have also been reported in males. While the immune privilege status of human testis protects the germ cells from an immune attack, it can also make the testis a succeptible reservoir for viruses such as human immunodeficiency virus-1, Zika virus and severe acute respiratory syndrome coronavirus-2, all of which have adverse consequences on male reproduction.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1534
Author(s):  
Evangelos N. Symeonidis ◽  
Evangelini Evgeni ◽  
Vasileios Palapelas ◽  
Dimitra Koumasi ◽  
Nikolaos Pyrgidis ◽  
...  

Male infertility, a relatively common and multifactorial medical condition, affects approximately 15% of couples globally. Based on WHO estimates, a staggering 190 million people struggle with this health condition, and male factor is the sole or contributing factor in roughly 20–50% of these cases. Nowadays, urologists are confronted with a wide spectrum of conditions ranging from the typical infertile male to more complex cases of either unexplained or idiopathic male infertility, requiring a specific patient-tailored diagnostic approach and management. Strikingly enough, no identifiable cause in routine workup can be found in 30% to 50% of infertile males. The medical term male oxidative stress infertility (MOSI) was recently coined to describe infertile men with abnormal sperm parameters and oxidative stress (OS), including those previously classified as having idiopathic infertility. OS is a critical component of male infertility, entailing an imbalance between reactive oxygen species (ROS) and antioxidants. ROS abundance has been implicated in sperm abnormalities, while the exact impact on fertilization and pregnancy has long been a subject of considerable debate. In an attempt to counteract the deleterious effects of OS, urologists resorted to antioxidant supplementation. Mounting evidence indicates that indiscriminate consumption of antioxidants has led in some cases to sperm cell damage through a reductive-stress-induced state. The “antioxidant paradox”, one of the biggest andrological challenges, remains a lurking danger that needs to be carefully avoided and thoroughly investigated. For that reason, oxidation-reduction potential (ORP) emerged as a viable ancillary tool to basic semen analysis, measuring the overall balance between oxidants and antioxidants (reductants). A novel biomarker, the Male infertility Oxidative System (MiOXSYS®), is a paradigm shift towards that goal, offering a quantification of OS via a quick, reliable, and reproducible measurement of the ORP. Moderation or “Μέτρον” according to the ancient Greeks is the key to successfully safeguarding redox balance, with MiOXSYS® earnestly claiming its position as a guarantor of homeostasis in the intracellular redox milieu. In the present paper, we aim to offer a narrative summary of evidence relevant to redox regulation in male reproduction, analyze the impact of OS and reductive stress on sperm function, and shed light on the “antioxidant paradox” phenomenon. Finally, we examine the most up-to-date scientific literature regarding ORP and its measurement by the recently developed MiOXSYS® assay.


2021 ◽  
Author(s):  
Ida Marie Boisen ◽  
John Erik Nielsen ◽  
Lieve Verlinden ◽  
Mette Lorenzen ◽  
Rune Holt ◽  
...  

Vitamin D is important for gonadal function in rodents, and improvement of vitamin D status in men with low sperm counts increases live birth rate. Vitamin D is a regulator of transcellular calcium transport in the intestine and kidney and may influence the dramatic changes in the luminal calcium concentration in epididymis. Here, we show spatial expression in the male reproductive tract of vitamin D receptor (VDR)-regulated factors involved in calcium transport: Transient receptor potential vanilloid 5/6 (TRPV5/6), sodium/calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1 (PMCA1), calbindin D9k, calcium-sensing receptor (CaSR), and parathyroid hormone-related peptide (PTHrP) in mouse and human testis and epididymis. Testicular Casr expression was lower in Vdr ablated mice compared with controls. Moreover, expression levels of Casr and Pthrp were strongly correlated in both testis and epididymis and Pthrp was suppressed by 1,25(OH)2D3 in a spermatogonial cell line. The expression of CaSR in epididymis may be of greater importance than in the gonad in mice as germ cell-specific Casr deficient mice had no major reproductive phenotype, and coincubation with a CaSR-agonist had no effect on human sperm-oocyte binding. In humans, seminal calcium concentration between 5-10 mM was associated with a higher fraction of motile and morphologically normal sperm cells and the seminal calcium concentration was not associated with serum calcium levels. In conclusion, VDR regulates CaSR and PTHrP, and both factors may be involved in the regulation of calcium transport in the male reproductive tract with possible implications for sperm function and storage.


Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 98
Author(s):  
Yoo-Jin Park ◽  
Myung-Geol Pang

Mitochondria are structurally and functionally distinct organelles that produce adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS), to provide energy to spermatozoa. They can also produce reactive oxidation species (ROS). While a moderate concentration of ROS is critical for tyrosine phosphorylation in cholesterol efflux, sperm–egg interaction, and fertilization, excessive ROS generation is associated with male infertility. Moreover, mitochondria participate in diverse processes ranging from spermatogenesis to fertilization to regulate male fertility. This review aimed to summarize the roles of mitochondria in male fertility depending on the sperm developmental stage (from male reproductive tract to female reproductive tract). Moreover, mitochondria are also involved in testosterone production, regulation of proton secretion into the lumen to maintain an acidic condition in the epididymis, and sperm DNA condensation during epididymal maturation. We also established the new signaling pathway using previous proteomic data associated with male fertility, to understand the overall role of mitochondria in male fertility. The pathway revealed that male infertility is associated with a loss of mitochondrial proteins in spermatozoa, which induces low sperm motility, reduces OXPHOS activity, and results in male infertility.


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