![\"\"](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/10\/low-res.jpeg\" "\\"Scientists")
Recovered sperm and offspring obtained via intracytoplasmic sperm injection (ICSI). Mashiko et al., 2025<\/p>\nA new mRNA approach successfully restored sperm production and led to the birth of viable offspring in a genetic mouse model.\u00a0<\/p>\n
The technique has been developed by the University of Osaka, Japan, in collaboration with Baylor College of Medicine, the US.<\/p>\n
This new therapy addresses non-obstructive azoospermia (NOA), a form of genetic male infertility characterized by a complete failure or halt in sperm production. The condition currently has very few available treatment options.<\/p>\n
Interestingly, the treatment successfully targeted specific testicular genes in a mouse model, thereby restoring sperm production and leading to the birth of viable offspring.<\/p>\n
\u201cIt introduces a safer, non-integrating alternative to traditional gene therapies, providing hope for untreatable infertility cases in humans,\u201d the researchers noted in the study.\u00a0<\/p>\n
Recovered sperm and offspring obtained via intracytoplasmic sperm injection (ICSI). Mashiko et al., 2025<\/p>\n
Targeting sperm-producing cells in mRNA therapy<\/p>\n
Infertility is a major global health issue, affecting one in six couples worldwide, with roughly half of all cases attributed to male factors.\u00a0<\/p>\n
One of the most severe forms of male infertility<\/a> is NOA, where a man has a complete lack of sperm in his ejaculate despite having normal hormone levels.\u00a0<\/p>\n This condition is primarily caused by genetic defects that severely disrupt or halt the complex process of sperm production, known as spermatogenesis.\u00a0<\/p>\n Due to its underlying genetic nature, treatment options for NOA are currently limited, leaving thousands of affected individuals without a biological path to father children.<\/p>\n The new research focused on an NOA mouse model specifically designed to mimic human genetic deficiencies causing meiotic arrest \u2014 a stage where sperm production stalls.\u00a0<\/p>\n The deficiency was caused due to defects in the Pdha2 gene<\/a>.\u00a0<\/p>\n The team employed a novel method using lipid nanoparticles (LNPs) to deliver messenger RNA (mRNA) directly to the testes.<\/p>\n The LNPs were injected carrying the Pdha2 mRNA into the rete testis to ensure broad delivery throughout the seminiferous tubules.<\/p>\n A key innovation involved modifying the mRNA with a specific sequence (Dsc1 3\u2019-UTR) to direct its expression predominantly to germ cells, the cells responsible for producing sperm, rather than supporting Sertoli cells.<\/p>\n This targeted delivery proved crucial for the treatment\u2019s success.<\/p>\n \u201cUsing fully synthetic LNPs to deliver mRNA minimizes genome-integration concerns and enables us to restore spermatogenesis in a defined genetic model,\u201d said Professor Masahito Ikawa, senior author of the study.<\/p>\n<\/p>\n Healthy pups <\/p>\n Within two weeks of treatment, the Pdha2 knockout mice, which initially exhibited meiotic arrest, showed a resumption of meiotic progression. <\/p>\n It led to the formation of round spermatids, and by three weeks, mature sperm were successfully produced.<\/p>\n The ultimate test of the treatment\u2019s efficacy came with fertilization<\/a>.\u00a0<\/p>\n Sperm retrieved from the treated mice were used for intracytoplasmic sperm injection (ICSI), resulting in 26 healthy pups from 117 embryos.<\/p>\n These offspring developed normally, were fertile, and showed \u201cno large genomic alterations.\u201d The findings showcase the safety and precision of the LNP-mRNA delivery system.<\/p>\n