Oxidative stress-induced alterations in seminal plasma antioxidants: Is there any association with keap1 gene methylation in human spermatozoa?

Differential expression of long non-coding RNAs in colon cancer: Insights from transcriptomic analysis

BACKGROUND

Colon Cancer (CC) incidence has sharply grown in recent years. Long non-coding RNAs (lncRNA) are produced by a group of non-protein-coding genes, and have important functions in controlling gene expression and impacting the biological features of various malignancies including CC.

METHODS

Our research focused on examining the function of lncRNAs in the development of colon cancer. To this end, we selected and analyzed a dataset (GSE104836) from the GEO database, which contained information about the expression of mRNAs and lncRNAs in both colon cancer tissues and normal adjacent paired tumor tissues. The DESeq2 R package in Bioconductor was used to identify differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) that showed differences in expression levels. Next, by literature review of previous studies, we chose two lncRNAs (FENDRR and LINC00092) for additional studies. To validate our findings, a series of tests were performed on a total of 31 tumor tissues and normal paired adjacent tumor tissues. The lncRNA expression levels were assessed in tumor tissues as well as in surrounding normal tumor tissues.

RESULTS

The data confirmed that just two particular lncRNAs, FENDRR and LINC00092, had considerably decreased expression levels throughout all stages of cancer. In addition, the survival assay was conducted using the GEPIA2 software, revealing that a reduced expression of FENDRR is correlated with a reduced overall survival. Furthermore, our investigation using receiver operating characteristic (ROC) methodology revealed that these two lncRNAs had significant discriminatory ability between colon cancer and normal tissues. To determine the cause of the decrease in the activity of these two long non-coding RNAs (lncRNAs), we used methylation-specific PCR (MSP) to examine the methylation pattern of their promoter regions. Our investigation revealed hypermethylation in the promoter regions of FENDRR and LINC00092 within tumor tissues compared to normal adjacent tumor tissues.

CONCLUSION

Taken together, our findings revealed the lncRNAs signatures as potential therapeutic targets and molecular diagnostic biomarkers in colon cancer. Furthermore, the evidence provided substantiates the important role of promoter methylation in regulating the expression levels for both of these lncRNAs.

miR-29b-3p targetedly regulates VEGF to inhibit tumor progression and cisplatin resistance through Nrf2/HO-1 signaling pathway in non-small cell lung cancer

BACKGROUNDS

Non-small cell lung carcinoma (NSCLC) is a common type of lung cancer. Prior investigations have elucidated the pivotal role of miR-29b-3p in restraining tumor growth and metastasis. Nonetheless, it remains to be determined whether miR-29b-3p can effectively suppress NSCLC progression and enhance the sensitivity of NSCLC cells to cisplatin. This investigation sought to determine the mechanism by which miR-29b-3p inhibited the advancement of NSCLC and mitigated resistance to cisplatin.

METHODS

We initially assessed miR-29b-3p and VEGF levels in NSCLC tissues and cell lines. Next, miR-29b-3p expression was elevated in NSCLC cell lines H1975 and A549 by overexpression plasmid transfection. Following this, a sequence of molecular biology experiments was conducted to evaluate the impact of miR-29b-3p on the biological behaviors of NSCLC cells and their resistance to cisplatin. Additionally, we predicted VEGF was a target gene of miR-29b-3p by bioinformatics analysis. We next employed western blot to evaluate the protein expression of Nrf2 and HO-1 in NSCLC cells. Finally, we elucidated the effects of VEGF and Nrf2/HO-1pathway on NSCLC progression and cisplatin resistance by in vitro assays.

RESULTS

In comparison to paracancerous tissues and human normal lung epithelial cells, the expression of miR-29b-3p was notably reduced and VEGF expression was clearly elevated in NSCLC tissues and cells. Moreover, miR-29b-3p upregulated obviously suppressed the biological activities of NSCLC cells and increased their sensitivity to cisplatin. Furthermore, in NSCLC cells, miR-29b-3p bound to VEGF and negatively regulate its transcription. Additionally, miR-29b-3p overexpression also inhibited the Nrf2/HO-1 signaling pathway. Finally, the overexpression of VEGF and the activation of the Nrf2/HO-1 pathway reversed miR-29b-3p-mediated inhibitory effect on biological behaviors of NSCLC cells and increased the cisplatin resistance.

CONCLUSION

Our findings indicate that miR-29b-3p impedes NSCLC cells' biological behaviors and augments their sensitivity to cisplatin by targeting VEGF to modulate the Nfr2/HO-1 signaling pathway.

GRIM-19 in asthenozoospermia regulates GC-2 spd cell proliferation, apoptosis and migration

Asthenozoospermia (AZS) is a severe form of male infertility with no clear pathogenesis, despite numerous research efforts, there is no consensus on this. This study was to investigate the expression of gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) in the sperm of patients with asthenozoospermia and the regulation of GC-2 spd cell proliferation, apoptosis and migration. We analyzed the sperm samples from 82 asthenozoospermia and normal patients were collected in the First People's Hospital of Shangqiu and the First Affiliated Hospital of Zhengzhou University. Immunofluorescence, western blots and RT-qPCR analyses were used to verify the expressions of GRIM-19. MTT assays were used to assess cell proliferations, flow cytometry was performed to assess cell apoptosis, wound‑healing was performed to measure cell migration. Immunofluorescence showed that GRIM-19 is predominantly expressed in the sperm mid-piece, the mRNA expressions of GRIM-19 in sperms of the asthenozoospermia group were significantly low, relative to the normal group (OR 0.266; 95% CI = 0.081-0.868; P = 0.028). The protein expressions of GRIM-19 in sperms of the asthenozoospermia group were significantly lower than that of the normal group as well (GRIM-19/GAPDH: 0.827 ± 0.063 vs 0.458 ± 0.033; P < 0.001). GRIM-19 overexpression promotes GC-2 spd cell proliferation and migration and reduces apoptosis, while GRIM-19-silenced reduces GC-2 spd cell proliferation and migration and increased apoptosis. GRIM-19 is closely related to the occurrence of asthenozoospermia and promotes GC-2 spd cell proliferation and migration and reduces apoptosis.

Açai Berry Attenuates Cyclophosphamide-Induced Damage in Genitourinary Axis-Modulating Nrf-2/HO-1 Pathways

Cyclophosphamide (CYP) is used to treat different malignancies and autoimmune disorders in men. This chemotherapy frequently reduces tumors, which is beneficial, but also causes infertility because of severe oxidative stress, inflammation, and apoptosis in the bladder and testes brought on by its metabolite, acrolein. The goal of this study was to assess the efficacy of a novel food, açai berry, in preventing CYP-induced damage in the bladder and testes.

METHODS

CYP was administered intraperitoneally once during the experiment at a dose of 200 mg/kg body weight diluted in 10 mL/kg b.w. of water. Açai berry was administered orally at a dose of 500 mg/kg.

RESULTS

The administration of açai berry was able to reduce inflammation, oxidative stress, lipid peroxidation, apoptosis, and histological changes in the bladder and testes after CYP injection.

CONCLUSIONS

Our findings show for the first time that açai berry modulates physiological antioxidant defenses to protect the bladder and testes against CYP-induced changes.

Age-Related Decline of Male Fertility: Mitochondrial Dysfunction and the Antioxidant Interventions

Mitochondria are structurally and functionally unique organelles in male gametes. Apparently, as the only organelles remaining in mature sperm, mitochondria not only produce adeno-sine triphosphate (ATP) through oxidative phosphorylation (OXPHOS) to support sperm mobility, but also play key roles in regulating reactive oxidation species (ROS) signaling, calcium homeostasis, steroid hormone biosynthesis, and apoptosis. Mitochondrial dysfunction is often associated with the aging process. Age-dependent alterations of the epididymis can cause alterations in sperm mitochondrial functioning. The resultant cellular defects in sperm have been implicated in male infertility. Among these, oxidative stress (OS) due to the overproduction of ROS in mitochondria may represent one of the major causes of these disorders. Excessive ROS can trigger DNA damage, disturb calcium homeostasis, impair OXPHOS, disrupt the integrity of the sperm lipid membrane, and induce apoptosis. Given these facts, scavenging ROS by antioxidants hold great potential in terms of finding promising therapeutic strategies to treat male infertility. Here, we summarize the progress made in understanding mitochondrial dysfunction, aging, and male infertility. The clinical potential of antioxidant interventions was also discussed.

Antioxidant Paradox in Male Infertility: 'A Blind Eye' on Inflammation

The pathophysiology of male infertility involves various interlinked endogenous pathways. About 50% of the cases of infertility in men are idiopathic, and oxidative stress (OS) reportedly serves as a central mechanism in impairing male fertility parameters. The endogenous antioxidant system operates to conserve the seminal redox homeostasis required for normal male reproduction. OS strikes when a generation of seminal reactive oxygen species (ROS) overwhelms endogenous antioxidant capacity. Thus, antioxidant treatment finds remarkable relevance in the case of idiopathic male infertility or subfertility. However, due to lack of proper detection of OS in male infertility, use of antioxidant(s) in some cases may be arbitrary or lead to overuse and induction of 'reductive stress'. Moreover, inflammation is closely linked to OS and may establish a vicious loop that is capable of disruption to male reproductive tissues. The result is exaggeration of cellular damage and disruption of male reproductive tissues. Therefore, limitations of antioxidant therapy in treating male infertility are the failure in the selection of specific treatments targeting inflammation and OS simultaneously, two of the core mechanisms of male infertility. The present review aims to elucidate the antioxidant paradox in male infertility treatment, from the viewpoints of both induction of reductive stress as well as overlooking the inflammatory consequences.

Oxidative Stress, Testicular Inflammatory Pathways, and Male Reproduction

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.

DNA methylation in human sperm: a systematic review

BACKGROUND

Studies in non-human mammals suggest that environmental factors can influence spermatozoal DNA methylation, and some research suggests that spermatozoal DNA methylation is also implicated in conditions such as subfertility and imprinting disorders in the offspring. Together with an increased availability of cost-effective methods of interrogating DNA methylation, this premise has led to an increasing number of studies investigating the DNA methylation landscape of human spermatozoa. However, how the human spermatozoal DNA methylome is influenced by environmental factors is still unclear, as is the role of human spermatozoal DNA methylation in subfertility and in influencing offspring health.

OBJECTIVE AND RATIONALE

The aim of this systematic review was to critically appraise the quality of the current body of literature on DNA methylation in human spermatozoa, summarize current knowledge and generate recommendations for future research.

SEARCH METHODS

A comprehensive literature search of the PubMed, Web of Science and Cochrane Library databases was conducted using the search terms 'semen' OR 'sperm' AND 'DNA methylation'. Publications from 1 January 2003 to 2 March 2020 that studied human sperm and were written in English were included. Studies that used sperm DNA methylation to develop methodologies or forensically identify semen were excluded, as were reviews, commentaries, meta-analyses or editorial texts. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to objectively evaluate quality of evidence in each included publication.

OUTCOMES

The search identified 446 records, of which 135 were included in the systematic review. These 135 studies were divided into three groups according to area of research; 56 studies investigated the influence of spermatozoal DNA methylation on male fertility and abnormal semen parameters, 20 studies investigated spermatozoal DNA methylation in pregnancy outcomes including offspring health and 59 studies assessed the influence of environmental factors on spermatozoal DNA methylation. Findings from studies that scored as 'high' and 'moderate' quality of evidence according to GRADE criteria were summarized. We found that male subfertility and abnormal semen parameters, in particular oligozoospermia, appear to be associated with abnormal spermatozoal DNA methylation of imprinted regions. However, no specific DNA methylation signature of either subfertility or abnormal semen parameters has been convincingly replicated in genome-scale, unbiased analyses. Furthermore, although findings require independent replication, current evidence suggests that the spermatozoal DNA methylome is influenced by cigarette smoking, advanced age and environmental pollutants. Importantly however, from a clinical point of view, there is no convincing evidence that changes in spermatozoal DNA methylation influence pregnancy outcomes or offspring health.

WIDER IMPLICATIONS

Although it appears that the human sperm DNA methylome can be influenced by certain environmental and physiological traits, no findings have been robustly replicated between studies. We have generated a set of recommendations that would enhance the reliability and robustness of findings of future analyses of the human sperm methylome. Such studies will likely require multicentre collaborations to reach appropriate sample sizes, and should incorporate phenotype data in more complex statistical models.

Hidrox® Counteracts Cyclophosphamide-Induced Male Infertility through NRF2 Pathways in a Mouse Model

BACKGROUND

Every year, men use cyclophosphamide to treat various cancers and autoimmune diseases. On the one hand, this chemotherapy often has the beneficial effect of regressing the tumor, but on the other hand, it leads to infertility due to excessive oxidative stress and apoptosis in the testes caused by its metabolite, acrolein.

METHODS

The objective of this study was to evaluate the beneficial power of a new compound called Hidrox^®, containing 40-50% hydroxytyrosol, in counteracting the damage related to fertility induced by cyclophosphamide. The study was conducted using a single intraperitoneal injection of cyclophosphamide at a dose of 200 mg/kg b.w, in distilled water at 10 mL/kg b.w. The treatment was administered via the oral administration of Hidrox^® at a dose of 50 mg/kg.

RESULTS

Our study confirms that the use of cyclophosphamide causes a series of sperm and histological alterations strongly connected with oxidative stress, lipid peroxidation, and apoptosis.

CONCLUSION

Our results demonstrate for the first time that Hidrox^® protects testes from CYP-induced alterations by the modulation of physiological antioxidant defenses.

The protective effect of melatonin on radiofrequency electromagnetic fields of mobile phone-induced testicular damage in an experimental mouse model

Radiofrequency electromagnetic radiation (RF-EMR) from mobile devices has undesirable effects on the male reproductive organs. Melatonin with antioxidant potential can help to prevent these damages. Therefore, the aim of this study was to evaluate the protective effect of melatonin on testicular damage induced by RF-EMR of mobile phone. In this experimental study, 32 adult male BALB/c mice were divided randomly into four groups: control, melatonin (2 mg/kg, for 30 consecutive days, intraperitoneally), RF-EMR (900 MHz, 100 to 300 MT, 54 to 160 W/m) (4 hr per day, whole body) and melatonin + RF-EMR groups. One day after the last prescription were evaluated oxidative stress parameters, testosterone level and histopathological assays of the testis. EMR of mobile phone led to the induction of oxidative stress, testicular tissue damage and decreased testosterone. Treatment with melatonin improved oxidative stress parameters such as MDA and GSH, and testis injury score, increased the thickness of the germinal epithelial thickness and diameter of the seminiferous tubule, and decreased testosterone hormone in the EMR-exposed mice, and these differences were significant(p < .05). Data showed that melatonin with its antioxidant property can decrease oxidative damage induced by RF-EMR of mobile phones on testis tissue.

Comparing the different methods of sperm chromatin assessment concerning ART outcomes

OBJECTIVE

Sperm DNA fragmentation and maturation directly interferes with reproductive efficiency. Although there are several methods for assessing sperm DNA integrity, however, many of them are laborious and require high-precision equipment in the clinics. Thus, evaluating economic and reliable methods to prepare suitable sperm for assisted reproductive technologies without DNA damage is critical.

MATERIAL AND METHODS

A total of 114 semen samples were collected and analyzed using computer-assisted semen analysis. The DNA fragmentation index (DFI) of all samples was evaluated by two methods of sperm chromatin dispersion (SCD) and sperm chromatin structure assay (SCSA). Besides, chromatin maturation index (CMI) was assessed by three methods including aniline blue (AB)-sperm chromatin maturation assay (SCMA), fluorescence microscopic chromomycin A3 (fmCMA3), and flow cytometric CMA3 (fcCMA3).

RESULTS

The result showed that the DFI had no statistically significant differences (p>0.05) between SCSA (26.98%±1.28%) and SCD (27.88%±1.278%), although SCD demonstrated a strong correlation with DNA maturity (p<0.001), which had not been seen in SCSA. Besides, the CMI demonstrated significant differences (p<0.001) when assessed by AB-SCMA (14.86%±0.65%), fmCMA3 (29.18%±1.01%), and fcCMA3 (22.45%±0.62%). Among these, only the fmCMA3 showed a significant correlation with semen parameters (p<0.01) and embryo development (p<0.001).

CONCLUSION

It seems that SCD and fmCMA3 were more accessible, affordable, and reliable tests for assessing DFI and CMI. It appeared these two methods may be the best choices for evaluating sperm DNA integrity in clinics.

Degradation of proteins by PROTACs and other strategies

Blocking the biological functions of scaffold proteins and aggregated proteins is a challenging goal. PROTAC proteolysis-targeting chimaera (PROTAC) technology may be the solution, considering its ability to selectively degrade target proteins. Recent progress in the PROTAC strategy include identification of the structure of the first ternary eutectic complex, extra-terminal domain-4-PROTAC-Von-Hippel-Lindau (BRD4-PROTAC-VHL), and PROTAC ARV-110 has entered clinical trials for the treatment of prostate cancer in 2019. These discoveries strongly proved the value of the PROTAC strategy. In this perspective, we summarized recent meaningful research of PROTAC, including the types of degradation proteins, preliminary biological data in vitro and in vivo, and new E3 ubiquitin ligases. Importantly, the molecular design, optimization strategy and clinical application of candidate molecules are highlighted in detail. Future perspectives for development of advanced PROTAC in medical fields have also been discussed systematically.

The effect of paternal age on semen quality and fertilization outcome in men with normal sperm DNA compaction, reactive oxygen species, and total antioxidant capacity levels

OBJECTIVE

Studies showed a decrease of the semen analysis parameters and an increase in the average age of first-time fathers over the past several decades. The aim of the present study was to assess the influence of paternal age on semen quality and fertilization outcomes in men with normal sperm DNA fragmentation and chromatin maturation index (DFI and CMI), reactive oxygen species (ROS), and total antioxidant capacity (TAC) levels.

MATERIAL AND METHODS

The study was performed on 70 men with their wife's age ≤38 years and normal sperm DFI, CMI, ROS, and TAC levels. None of the couples had a history of genital inflammation, chronic diseases, endocrine abnormality, chromosomal aberrations, Y chromosome microdeletion, azoospermia, and leukocytospermia. These men were separated into 2 groups according to their age (group A: age <45 years and group B: age ≥45 years). Semen analysis and fertilization outcome after using the intracytoplasmic sperm injection were assessed in both groups.

RESULT

Sperm concentration showed a significant reduction in group B (p=0.04). Although semen volume, sperm normal morphology, and progressive motility were decreased in group B, the reduction was not significant when compared with group A (p=0.09, p=0.47, and p=0.77, respectively). In addition, the differences of embryo quality with grades A, B, and C and 8-cell embryo formation were not statistically significant between the 2 groups.

CONCLUSION

These results demonstrated that in men with normal sperm DFI, CMI, ROS, and TAC levels, there were no significant changes in semen parameters and fertilization outcomes with an increasing age.