Shugoshin 1 injections help "rejuvenate" eggs/oocytes in older women

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#1

This study is fascinating and I am wondering if there is a way to get hold of Shugoshin 1 or to be part of clinical trials? I am about to try to get pregnant with eggs I froze at 38 and there is a high probability those eggs are good. However I would like for my child to have a sibling and have other eggs frozen from age 44. The chances of them being good are in the 1 to 5% range.

I wanted to share this study to see if anyone knows how I could get a hold of Shugoshin 1 or how I could participate in trials. I was about to partake in the Vibrant study which uses rapamycin to slow ovarian aging, and therefor, aging in women.

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#2

It seems that this is still too early to be looking at for human applications, its just one mouse study:

Here is the paper, and I’ve done a Gemini Pro analysis of it below:

Turning Back the Clock on the Fertile Window: SGO1 Rescue

In a significant advance for reproductive longevity, researchers have identified a primary molecular culprit behind the “biological clock” that causes age-related infertility and birth defects: the loss of the protein Shugoshin 1 (SGO1). Aneuploidy—an abnormal number of chromosomes in eggs—rises sharply with maternal age, leading to miscarriages and failed IVF cycles. While it was known that the “glue” holding chromosomes together (the cohesin complex) degrades over time, the upstream trigger remained elusive. This study reveals that the erosion of SGO1, a guardian protein that protects this cohesive glue, is a key driver of chromosomal errors in aging eggs.

Crucially, the team demonstrated that this defect is reversible. By microinjecting mRNA encoding SGO1 into aged mouse and human oocytes, they restored the protective machinery at the centromeres. This intervention significantly reduced “premature sister chromatid separation” (PSSC)—the most common segregation error in older eggs—halving the error rate in human samples. The study establishes a direct link between the cessation of localized transcription (RNA synthesis) at the chromosome center and the destabilization of SGO1, suggesting that keeping the genome “transcriptionally active” in specific regions is vital for structural integrity. This proof-of-concept suggests that reproductive aging is not merely cumulative damage, but a loss of regulatory maintenance that can be externally patched.

Context & Impact

  • Institution: Max Planck Institute for Multidisciplinary Sciences, Germany.
  • Journal: bioRxiv (Preprint).
  • Impact Evaluation: As this is a preprint, it does not yet have a Journal Impact Factor (JIF). BioRxiv is a repository for pre-publication data.

Part 2: The Technical Biohacker Analysis

Study Design Specifications

  • Type: Ex vivo / In vitro (Oocyte culture and microinjection).

  • Subjects:

    • Murine: 129S6 mice. Young: 8–12 weeks. Aged: 60–65 weeks (approx. 14–15 months).
    • Human: Surplus oocytes from IVF patients. Young: <35 years. Aged: ≄35 years.

  • Sample Size:

    • Mouse: Variable per experiment (e.g., n=27–52 eggs per group for rescue experiments).
    • Human: Limited clinical samples (e.g., n=73 control vs. n=38 treated).

Lifespan Analysis

  • Reproductive Lifespan Extension: The intervention functionally “reversed” the age of the oocyte in vitro. SGO1 supplementation reduced segregation errors in aged mouse eggs (60–65 weeks) to levels comparable to young controls (8–12 weeks). In human eggs from women over 35, SGO1 mRNA reduced PSSC rates from ~65% to ~44% (though statistical significance was borderline due to low N in the aged subgroup, the trend was robust across all donors).

Mechanistic Deep Dive

The paper delineates a collapse in the Pericentromeric Transcription Pathway as the root cause of cohesion loss.

  1. Transcription as a Tether: In young oocytes, active RNA Polymerase II transcription at the pericentromere produces non-coding RNAs (Major Satellite RNAs in mice).
  2. Recruitment Cascade: These transcripts are essential for recruiting and maintaining SGO1 at the inner centromere.
  3. The Protection Complex: SGO1 recruits PP2A (Protein Phosphatase 2A). PP2A keeps the cohesin subunit REC8 dephosphorylated, protecting it from premature cleavage by the enzyme Separase.
  4. The Aging Defect: Aging oocytes exhibit reduced pericentromeric transcription. This leads to a loss of SGO1 →loss of PP2A → phosphorylation and loss of REC8 → Premature Sister Chromatid Separation (PSSC) →Aneuploidy.
  5. The Fix: Injecting SGO1 mRNA bypasses the transcriptional defect, restoring PP2A localization and stabilizing REC8. Injecting Major Satellite RNA alone worked in young oocytes with chemically inhibited transcription, but failed in aged oocytes, suggesting the SGO1 protein itself becomes the limiting factor with age.

Novelty

  • Transcription-Cohesion Link: While known in mitosis, this is the first confirmation that pericentromeric transcription actively maintains cohesion in mammalian meiosis and that this process fails with age.

  • Human Translation: Previous rescues were largely murine. This study provides rare, direct evidence that SGO1 supplementation works in human eggs , reducing error rates by nearly half.

  • Upstream Target: It moves the target from the cohesin ring (which is hard to replenish) to the regulator SGO1 (which can be replenished), offering a more viable therapeutic angle.

Critical Limitations

  • Delivery Vector: The study used direct microinjection of mRNA into individual oocytes. This is feasible for IVF (ICSI) but impossible for systemic “anti-aging” therapy. It is strictly an assisted reproduction intervention, not a preventative biohack for natural conception.
  • Statistical Power (Human): The “aged” human data (≄35 years) for the rescue experiment had a small sample size (n=9 treated eggs in the age-stratified group), preventing it from reaching statistical significance despite a strong positive trend. The combined dataset was significant, but the specific claim for older women relies on extrapolation of the trend [Confidence: Medium].
  • Incomplete Rescue: SGO1 supplementation reduced errors but did not perfectly eliminate them (e.g., human error rates dropped to ~29%, not 0%). Other degradation pathways likely exist.
  • Ex Vivo Only: We do not know if these “rescued” eggs result in viable, healthy offspring, or if the intervention introduces other epigenetic anomalies due to SGO1 overexpression.