Nomogram based on a circular RNA biomarker for predicting the likelihood of successful sperm retrieval via microdissection testicular sperm extraction in patients with idiopathic non-obstructive azoospermia

Human sperm RNA in male infertility

The function and value of specific sperm RNAs in apparently idiopathic male infertility are currently poorly understood. Whether differences exist in the sperm RNA profile between patients with infertility and fertile men needs clarification. Similarly, the utility of sperm RNAs in predicting successful sperm retrieval and assisted reproductive technique (ART) outcome is unknown. Patients with infertility and fertile individuals seem to have differences in the expression of non-coding RNAs that regulate genes controlling spermatogenesis. Several RNAs seem to influence embryo quality and development. Also, RNA types seem to predict successful sperm retrieval in patients with azoospermia. These findings suggest that sperm RNAs could influence decision-making during the management of patients with infertility. This evidence might help to identify possible therapeutic approaches aimed at modulating the expression of dysregulated genes in patients with infertility. Performing prospective studies with large sample sizes is necessary to investigate cost-effective panels consisting of proven molecular targets to ensure that this evidence can be translated to clinical practice.

Epigenetics of nonobstructive azoospermia

Nonobstructive azoospermia (NOA) is a severe and heterogeneous form of male factor infertility caused by dysfunction of spermatogenesis. Although various factors are well defined in the disruption of spermatogenesis, not all aspects due to the heterogeneity of the disorder have been determined yet. In this review, we focus on the recent findings and summarize the current data on epigenetic mechanisms such as DNA methylation and different metabolites produced during methylation and demethylation and various types of small noncoding RNAs involved in the pathogenesis of different groups of NOA.

Association between anti-Müllerian hormone concentrations and sperm retrieval outcomes in patients with idiopathic nonobstructive azoospermia: a systematic review and meta-analysis

ABSTRACT

Microdissection testicular sperm extraction (mTESE) is commonly performed to retrieve sperm in the testes for assisted reproductive techniques in patients with idiopathic nonobstructive azoospermia (iNOA). However, the success rate of sperm retrieval varies among individuals. We aim to investigate the association between clinical parameters and sperm retrieval outcomes in patients with iNOA. We searched PubMed, EMBASE, and Web of Science from database inception to August 2, 2023. The main measure was whether sperm retrieval was successful in patients with iNOA who underwent mTESE. Pooled estimates of the sperm retrieval rate and weighted mean differences were calculated using random-effects models. The overall sperm retrieval rate was 36.8% (95% confidence interval [CI]: 27.5%-46.0%, I2 = 95.0%) in nine studies comprising 1892 patients with iNOA. No significant differences were found in age, testicular volume, serum total testosterone concentrations, or inhibin B concentrations between positive and negative sperm retrieval outcomes. Lower anti-Müllerian hormone concentrations in patients with iNOA were associated with a positive outcome of mTESE (weighted mean differences: -2.70; 95% CI: -3.94--1.46, I2 = 79.0%). In conclusion, this study shows a significant relationship between anti-Müllerian hormone and sperm retrieval outcomes in patients with iNOA, while age, testicular volume, total testosterone, and inhibin B show no significant association. These findings have important implications for assessing the potential success of sperm retrieval and selecting appropriate treatment strategies in patients with iNOA.

Clinical predictors of successful outcomes for couples with nonobstructive azoospermic male partners undergoing micro-TESE

ABSTRACT

Nonobstructive azoospermia (NOA) is the most challenging and complex clinical scenario for infertile men. Besides circumstances such as hypogonadotropic hypogonadism, surgical sperm retrieval is typically necessary, and microdissection testicular sperm extraction (micro-TESE) is the procedure of choice for men with NOA desiring to father children with their own gametes. Micro-TESE results in the highest numbers of sperm cells retrieved for use with in vitro fertilization/intracytoplasmic sperm injection (ICSI) in comparison to all other techniques for surgical sperm retrieval in men with NOA. Several factors may affect sperm retrieval rate and ICSI outcomes, including the patient's age, testicular volume, histopathological and genetic profile, and serum hormone levels. This article aims to review the medical literature describing predictors of successful micro-TESE and the outcomes of ICSI in men with NOA.

Role of Follicle-stimulating Hormone, Inhibin B, and Anti-Müllerian Hormone in Predicting Sperm Retrieval from Men with Nonobstructive Azoospermia Undergoing Microdissection Testicular Sperm Extraction: A Systematic Review and Meta-analysis

Background and objective

No clear-cut markers for predicting positive sperm retrieval (+SR) at microdissection testicular sperm extraction (mTESE) have been identified thus far. Our aim was to conduct a systematic review and meta-analysis to evaluate the ability of follicle-stimulating hormone (FSH), inhibin B (InhB), and anti-Müllerian hormone (AMH) to predict +SR in men with nonobstructive azoospermia (NOA) undergoing mTESE.

Methods

We performed a search in the PubMed, EMBASE, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Thirty-four publications were selected for inclusion in the analysis.

Key findings and limitations

Overall, the mean +SR rate was 45%. Pooled standardized mean difference (SMD) values revealed significant hormonal differences between the +SR and -SR groups, with lower FSH (SMD -0.30), higher InhB (SMD 0.54), and lower AMH (SMD -0.56) levels in the +SR group. Pooled odds ratios (Ors) revealed no significant prediction of +SR by either FSH (OR 1.03, 95% confidence interval [CI] 1.00-1.06) or InhB (OR 1.01, 95% CI 1.00-1.02), despite variations in baseline levels and study heterogeneity. Conversely, AMH had significant predictive value (OR 0.82, 95% CI 0.73-0.92), with lower baseline levels in the +SR group. InhB and FSH levels were higher in the +SR group, while InhB exhibited the opposite trend.

Conclusions and clinical implications

Despite study heterogeneity, our meta-analysis findings support the ability of AMH to predict +SR for men with NOA undergoing mTESE.

Patient summary

We conducted a review and analysis of results from previous studies. Our findings show that for men with an infertility condition called nonobstructive azoospermia, blood levels of anti-Müllerian hormone can predict successful extraction of sperm using a microsurgical technique. Levels of two other hormones did not predict successful sperm extraction.

A detection model of testis-derived circular RNAs in serum for predicting testicular sperm retrieval rate in non-obstructive azoospermia patients

BACKGROUND

Microdissection testicular sperm extraction is an effective method to retrieve sperm from non-obstructive azoospermia patients. However, its successful rate is less than 50%.

OBJECTIVES

To identify the predictive value of circular RNAs in serum for sperm retrieval rate in non-obstructive azoospermia patients.

MATERIALS AND METHODS

180 non-obstructive azoospermia patients were recruited in this study, including 84 individuals with successful sperm retrieval and 96 individuals with failed sperm retrieval. Our study contained two phases. First, 20 patients, selected from the 180 patients, were included in screening cohort. In this cohort, the top 20 circular RNAs from our previous testicular circRNA profiles were verified between successful and failed sperm retrieval groups using real-time polymerase chain reaction. Six circular RNAs with the most significantly different expressions were selected for further verification. Second, the 180 patients were included as discovery cohort to verify the six circular RNAs. Circular RNAs were extracted from serum in each participant. Logistic regression analysis was further performed to identify the predictive value and the area under the curve analysis was used to evaluate diagnostic efficiency, sensitivity, and specificity.

RESULTS

Six circular RNAs including hsa_circ_0058058, hsa_circ_0008045, hsa_circ_0084789, hsa_circ_0000550, hsa_circ_0007422, and hsa_circ_0004099 showed aberrant expressions between the successful and failed sperm retrieval group. In addition, both single-circular RNA panels and multi-circular RNA panels were finally verified to be significant in predicting sperm retrieval rate. Notably, multi-circular RNAs panels demonstrated better predictive abilities compared with single-circRNA panels, and the combined panel of six-circular RNAs (risk score = 1.094×hsa_circ_0058058+0.697×hsa_circ_0008045+0.718×hsa_circ_0084789-0.591×hsa_circ_0000550-0.435×hsa_circ_0007422-1.017×hsa_circ_0004099-1.561) exhibited the best predictive ability in the present study with an AUC of 0.977, a sensitivity of 91.7% and a specificity of 86.5%. A higher risk score indicated a higher risk of failure in sperm retrieval.

DISCUSSION AND CONCLUSION

Our study was the first to report that testis-derived circular RNAs in serum have the ability to predict sperm retrieval rate in non-obstructive azoospermia patients, whether it is a single-circular RNA or a combination of multi-circular RNAs.

Protein-coding circular RNAs - mechanism, detection, and their role in cancer and neurodegenerative diseases

Circular RNAs (circRNAs) are a unique class of non-coding RNAs and were originally thought to have no protein-coding potential due to their lack of a 5' cap and 3' poly(A) tail. However, recent studies have challenged this notion and revealed that some circRNAs have protein-coding potential. They have emerged as a key area of interest in cancer and neurodegeneration research as recent studies have identified several circRNAs that can produce functional proteins with important roles in cancer progression. The protein-coding potential of circRNAs is determined by the presence of an open reading frame (ORF) within the circular structure that can encode a protein. In some cases, the ORF can be translated into a functional protein despite the lack of traditional mRNA features. While the protein-coding potential of most circRNAs remains unclear, several studies have identified specific circRNAs that can produce functional proteins. Understanding the protein-coding potential of circRNAs is important for unravelling their biological functions and potential roles in disease. Our review provides comprehensive coverage of recent advances in the field of circRNA protein-coding capacity and its impact on cancer and neurodegenerative diseases pathogenesis and progression.