P-530 tRNA fragments in follicle fluid can be explored in Diminished Ovarian Reserve patients as a marker of IVF outcomes

Study question

Can tRNA fragments in follicle fluid be explored for markers that predict blastocyst formation in patients with diminished ovarian reserve?

Summary answer

tRNA-Ser-CGA-4 is up-regulated in the follicle fluid of patients with diminished ovarian reserve (DOR)

What is known already

tRNA fragments are a novel class of small non-coding RNAs that have been shown to play regulatory roles in reproductive biology.

Study design, size, duration

Non-Randomized case control study in patients presenting for IVF treatment at a University affiliated fertility clinic from September 2020- January 2021. Thirty three patients were included: 15 patients with DOR and 18 controls.

Participants/materials, setting, methods

Patients were stimulated by appropriate protocols according to their age, diagnosis and AMH.

At retrieval, non-bloody follicle fluid (FF) was retrieved for after removing the cumulus-oophorus complex. FF was centrifuged at 1600 g x 10 mins and filtered with 80 nm filter for analysis.

Main results and the role of chance

There were no differences between the two groups with respect to age, BMI and duration of infertility. The mean age was 35.1 years

As anticipated, the mean AMH, antral follicle count and number of eggs retrieved were statistically lower in the DOR groups compared with controls (<0.05)

The fertilization rate was 61.2% in DOR vs 79.5% in controls

The blastocyst rate was 39.5% in DOR patients and 50.6% in controls

Total RNA yield was lower in DOR patients, as 50% of the DOR samples had undetectable levels (p < 0.001).

Samples were predominantly processed in duplicate. Input into the pipeline was paired end data which showed an overall tRNA fragment count that was higher in the DOR population. Log2FC showed an up-regulation of the tRNA fragments tRNA-Ser-CGA-4, tRNA-Cys-GCA-15, tRNA-Cys-GCA-10 and tRNA-Cys-GCA-19 in the DOR population.

Limitations, reasons for caution

Undetectable levels in follicle fluid of some of the DOR patients introduced selection bias

Larger sample size and broader applicability across various ethnic groups.

Wider implications of the findings

Follicle fluid can be explored to give insight into the signaling pathways of ovarian biology

Non-invasive method of assessing oocyte competence

Useful in explaining the pathophysiology of DOR

Can these findings assist is in the identification of therapeutic targets to delay the progression of age related/non-age related DOR?

Trial registration number

not applicable

D-glucose transport in decapod crustacean hepatopancreas

Physiological mechanisms of gastrointestinal absorption of organic solutes among crustaceans remain severely underinvestigated, in spite of the considerable relevance of characterizing the routes of nutrient absorption for both nutritional purposes and formulation of balanced diets in aquaculture. Several lines of evidence attribute a primary absorptive role to the digestive gland (hepatopancreas) and a secondary role to the midgut (intestine). Among absorbed organic solutes, the importance of D-glucose in crustacean metabolism is paramount. Its plasma levels are finely tuned by hormones (crustacean hyperglycemic hormone, insulin-like peptides and insulin-like growth factors) and the function of certain organs (i.e. brain and muscle) largely depends on a balanced D-glucose supply. In the last few decades, D-glucose absorptive processes of the gastrointestinal tract of crustaceans have been described and transport mechanisms investigated, but not fully disclosed. We briefly review our present knowledge of D-glucose transport processes in the crustacean hepatopancreas. A discussion of previous results from experiments with hepatopancreatic epithelial brush-border membrane vesicles is presented. In addition, recent advances in our understandings of hepatopancreatic D-glucose transport are shown, as obtained (1) after isolation of purified R-, F-, B- and E-cell suspensions from the whole organ by centrifugal elutriation, and (2) by protein expression in hepatopancreatic mRNA-injected Xenopus laevis oocytes. In a perspective, the applicability of these novel methods to the study of hepatopancreatic absorptive function will certainly improve our knowledge of this structurally complex organ.