Abstract Infertility is a global problem being associated with emotional and financial burden. Recent studies have shown contribution of a group of non-coding RNAs, namely circular RNAs (circRNAs) to the etiology of some infertility conditions. CircRNA are transcribed from exons and form a circular RNA molecule, being abundant in eukaryotes. Traditionally classified as non-coding RNA, these transcripts are endogenously produced through either non-canonical back-splicing or linear splicing, typically produced from precursor messenger ribonucleic acid (pre-mRNA). While during the canonical splicing process the 3’ end of the exon is joined to the 5’ end of the succeeding exon to form linear mRNA, during backsplicing, the 3’ end to the 5’ end of the same exon is joined to make a circular molecule. circRNAs are involved in the regulation of several aspects of spermatogenesis. They appear to influence how stem germ cells grow and divide during the sperm production process. Malfunctions in circRNA activity could contribute to male infertility issues stemming from abnormalities in spermatogenesis. In the current review, we highlight the exciting potential of circRNAs as key players in the male fertility.
Abstract Disclosure: H. Alkaissi: None. B. Turturice: None. J.S. Rosenblum: None. A.S. Alzahrani: None. S. Talvacchio: None. A. Derkyi: None. M. Nazari: None. H. Wang: None. I. Pinal Fernandez: None. Z. Zhuang: None. K. Pacak: None. We recently discovered a new syndrome characterized by a triad of pheochromocytoma/paraganglioma, polycythemia, and somatostatinoma (so called Pacak-Zhuang syndrome) caused by somatic gain-of-function pathogenic variants in the EPAS1 gene, encoding hypoxia-inducible factor 2α (HIF-2α). Recently, we have described additional features of this syndrome, including systemic developmental vascular malformations in patients and the mouse model [1]. Here we evaluated vascular changes in the nailfold capillaries by using video capillaroscopy in four patients, three of whom were female and carried the same pathogenic somatic EPAS1 variant allele (EPAS1A530V). The first patient is an 18-year-old female with a history of ventricular septal defect since birth, acrocyanosis, abdominal paraganglioma, left adrenal pheochromocytoma, and polycythemia. The second patient is a 64-year-old female who presented with paraganglioma without polycythemia, in whom we found the EPAS1A530V variant from hair sample, and an additional variant (EPAS1P53[1]A) in a resected paraganglioma, confirming the diagnosis. The third patient is a 33-year-old female had polycythemia, right adrenal pheochromocytoma, abdominal paragangliomas and duodenal somatostatinoma. The fourth patient is a 25-year-old male with PZS bearing a somatic EPAS1M535V pathogenic variant and an additional D536_L542 deletion, with hypoplastic left ventricle and metastatic paraganglioma who never developed polycythemia due to concomitant sickle cell-thalassemia traits. Despite the notable differences in genotype between the first three patients compared to the fourth patient, whose genotype is more complex, nailfold video capillaroscopy of all these patients showed similar phenotype—abnormal capillary structure marked by widespread dilations, megacapillaries, sporadic capillary hemorrhages, and regions with diminished capillary density. While polycythemia has been implicated in megacapillaries phenotype, two of our patients did not have polycythemia at the time of evaluation, further supporting the role of HIF-2a in angiogenesis. In conclusion, we describe nailfold capillary changes on video capillaroscopy as a non-invasive clinical sign in patients with EPAS1 pathogenic variants. Whether this finding is due to circulating angiogenic factors secreted by the tissues harboring HIF-2α mutation, or a direct effect of HIF-2α on angiogenesis remains to be determined. References:1. Rosenblum JS, Wang H, Dmitriev PM, Cappadona AJ, Mastorakos P, Xu C, Jha A, Edwards N, Donahue DR, Munasinghe J, Nazari MA, Knutsen RH, Rosenblum BR, Smirniotopoulos JG, Pappo A, Spetzler RF, Vortmeyer A, Gilbert MR, McGavern DB, Chew E, Kozel BA, Heiss JD, Zhuang Z, Pacak K. Developmental vascular malformations in EPAS1 gain-of-function syndrome. Presentation: 6/2/2024
Abstract The parallel rise in obesity and male infertility in modern societies necessitates the identification of susceptibility genes underlying these interconnected health issues. In our study, we conducted a comprehensive search in the OMIM database to identify genes commonly associated with male infertility and obesity. Subsequently, we performed an insilico analysis using the REVEL algorithm to detect pathogenic single nucleotide polymorphisms (SNPs) in the coding region of these candidate genes. To validate our findings in vivo, we conducted a comprehensive analysis of SNPs and gene expression of candidate genes in 200 obese infertile subjects and 240 obese fertile individuals using ARMS-PCR. Additionally, we analyzed 20 fertile and 22 infertile obese individuals using Realtime-qPCR. By removing duplicated queries, we obtained 197 obesity-related genes and 102 male infertility-related genes from the OMIM database. Interestingly, the APOB gene was found in common between the two datasets. REVEL identified the rs13306194 variant as potentially pathogenic with a calculated score of 0.524. The study identified a significant association between the AA (P value = 0.001) genotype and A allele (P value = 0.003) of the APOB rs13306194 variant and infertility in obese men. APOB expression levels were significantly lower in obese infertile men compared to obese fertile controls ( p < 0.01). Moreover, the AA genotype of rs13306194 APOB was associated with a significant decrease in APOB gene expression in obese infertile men ( p = 0.05). There is a significant association between the Waist-to-Hip Ratio (WHR) and LH with infertility in the obese infertile group. These results are likely to contribute to a better understanding of the causes of male infertility and its association with obesity.