A semi-automated pipeline for quantifying drusen-like deposits in human induced pluripotent stem cell-derived retinal pigment epithelium cells

Age-Related Macular Degeneration (AMD) is a highly prevalent form of retinal disease amongst Western communities over 50 years of age. A hallmark of AMD pathogenesis is the accumulation of drusen underneath the retinal pigment epithelium (RPE), a biological process also observable in vitro. The accumulation of drusen has been shown to predict the progression to advanced AMD, making accurate characterisation of drusen in vitro models valuable in disease modelling and drug development. More recently, deposits above the RPE in the subretinal space, called reticular pseudodrusen (RPD) have been recognized as a sub-phenotype of AMD. While in vitro imaging techniques allow for the immunostaining of drusen-like deposits, quantification of these deposits often requires slow, low throughput manual counting of images. This further lends itself to issues including sampling biases, while ignoring critical data parameters including volume and precise localization. To overcome these issues, we developed a semi-automated pipeline for quantifying the presence of drusen-like deposits in vitro, using RPE cultures derived from patient-specific induced pluripotent stem cells (iPSCs). Using high-throughput confocal microscopy, together with three-dimensional reconstruction, we developed an imaging and analysis pipeline that quantifies the number of drusen-like deposits, and accurately and reproducibly provides the location and composition of these deposits. Extending its utility, this pipeline can determine whether the drusen-like deposits locate to the apical or basal surface of RPE cells. Here, we validate the utility of this pipeline in the quantification of drusen-like deposits in six iPSCs lines derived from patients with AMD, following their differentiation into RPE cells. This pipeline provides a valuable tool for the in vitro modelling of AMD and other retinal disease, and is amenable to mid and high throughput screenings.

Effects of foetal size, sex and developmental stage on adaptive transcriptional responses of skeletal muscle to intrauterine growth restriction in pigs

Intrauterine growth restriction (IUGR) occurs both in humans and domestic species. It has a particularly high incidence in pigs, and is a leading cause of neonatal morbidity and mortality as well as impaired postnatal growth. A key feature of IUGR is impaired muscle development, resulting in decreased meat quality. Understanding the developmental origins of IUGR, particularly at the molecular level, is important for developing effective strategies to mitigate its economic impact on the pig industry and animal welfare. The aim of this study was to characterise transcriptional profiles in the muscle of growth restricted pig foetuses at different gestational days (GD; gestational length ~ 115 days), focusing on selected genes (related to development, tissue injury and metabolism) that were previously identified as dysregulated in muscle of GD90 fetuses. Muscle samples were collected from the lightest foetus (L) and the sex-matched foetus with weight closest to the litter average (AW) from each of 22 Landrace x Large White litters corresponding to GD45 (n = 6), GD60 (n = 8) or GD90 (n = 8), followed by analyses, using RT-PCR and protein immunohistochemistry, of selected gene targets. Expression of the developmental genes, MYOD, RET and ACTN3 were markedly lower, whereas MSTN expression was higher, in the muscle of L relative to AW littermates beginning on GD45. Levels of all tissue injury-associated transcripts analysed (F5, PLG, KNG1, SELL, CCL16) were increased in L muscle on GD60 and, most prominently, on GD90. Among genes involved in metabolic regulation, KLB was expressed at higher levels in L than AW littermates beginning on GD60, whereas both IGFBP1 and AHSG were higher in L littermates on GD90 but only in males. Furthermore, the expression of genes specifically involved in lipid, hexose sugar or iron metabolism increased or, in the case of UCP3, decreased in L littermates on GD60 (UCP3, APOB, ALDOB) or GD90 (PNPLA3, TF), albeit in the case of ALDOB this only involved females. In conclusion, marked dysregulation of genes with critical roles in development in L foetuses can be observed from GD45, whereas for a majority of transcripts associated with tissue injury and metabolism differences between L and AW foetuses were apparent by GD60 or only at GD90, thus identifying different developmental windows for different types of adaptive responses to IUGR in the muscle of porcine foetuses.

A208 REAL WORLD EVIDENCE ANALYSIS WITH ADALIMUMAB BIOSIMILAR, MSB 11022, REPORTED WITH PATIENT CARE PROGRAM

Background

Injection site reactions (ISR), including injection site pain (ISP) are common adverse events reported with drugs administrated via subcutaneous injections. In clinical trials, the rates of ISR of adalimumab and adalimumab biosimilars range from 3% to 22.8% with citrate-buffer formulations, and from 1.7% to 16.6% with acetate-buffered and other formulations.

Purpose

The objective of this study is to evaluate ISR of adalimumab biosimilar, MSB 11022, in real world setting.

Method

Patients with immune mediated inflammatory diseases (IMIDs) enrolled with patient care program (PSP), and received at least one dose of adalimumab biosimilar, MSB 11022, were followed up. Incidences of injection site reactions, including injection site pain, burning sensation, bruise, erythema, hemorrhage, pruritus, and/or swelling were documented through unsolicited and solicited (outgoing following up calls with patients after their first injection through PSP contacts) reports. The data were collected between April 2021 and July 2022, and the rates of ISRs were assessed.

Result(s)

There were 2812 patients that met criteria through data collection period, with 219 cases of ISR. More than 99% of case reports were through solicited contacts, i.e., through case-manager follow up calls. Overall, rate of injection site reaction is 7.8% in patients with IMIDs treated with adalimumab biosimilar, MSB 11022. The rates of ISRs reported by disease are as follows: 6.8% of patients with Crohn's disease, 8.7% with ulcerative colitis, 8.8% with rheumatoid arthritis, 6.5% with psoriatic arthritis, 7.8% ankylosing spondylitis, 6.1% uveitis, 8.3% with hidradenitis suppurativa, and 11.1% of juvenile rheumatoid arthritis.

Conclusion(s)

Real world data provided evidence that ISR rate of adalimumab biosimilar, MSB 11022, is within the ranges of clinical trial data of adalimumab with citrate-buffer, and other formulations. As far as we know, this is the first real world evidence reported for ISR among adalimumab biosimilars with IMID patients.

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Disclosure of Interest

None Declared

Selective effects of focusing on spatial details in episodic future thinking for self-relevant positive events

Mental simulations of positive future events increase their detail/vividness and plausibility, with effects on cognitive-affective processes such as anticipated and anticipatory pleasure. More recently, spatial details have been distinguished as important in increasing detail and elaborating mental scene construction. Building on this research, this study (N = 54; M age = 26.9) compared simulations of positive, self-relevant future events spatial details (i.e. people, objects, sequences of actions) with simulations focused on content details. Cross-sectionally at baseline, spatial details uniquely predicted phenomenological characteristics of future events, including anticipatory pleasure. The guided simulations increased detail and vividness, mental imagery, and pre-experiencing in both conditions. The content simulation condition did not increase content details relative to the spatial simulation condition, however, the inverse was true. Relatedly, overall detail and vividness were higher in the spatial condition, as was perceived control. The findings are discussed in relation to future thinking and mental health.

O-310 Browsing the Male Genome to Unravel Its Reproductive Potential

Study question

Can whole genome profiling of sperm DNA be used to identify aspects of ART failure and predict embryo developmental competence?

Summary answer

Whole genome profiling of sperm DNA identifies germline gene mutations associated with reproductive failure and helps characterize subtle male factor infertility.

What is known already

A routine semen analysis provides limited information on the characteristics of the male gamete and is unable to predict spermatozoa performance in ART. Therefore, ancillary tests may be used to further assess the male gamete’s reproductive potential. Whole exome sequencing (WES) of the male genome carried out on somatic cells has proven to be a powerful technique capable of identifying the genetic roots of infertility. Here, we aim to preferentially detect germline mutations by exclusively sequencing spermatozoal DNA to identify genes related to the different underlying etiologies of reproductive failure.

Study design, size, duration

Over a 6-year period, 31 consenting couples with negative female infertility workups and normal semen parameters were included in this study. These couples were divided according to whether they reported a successful pregnancy with ART (fertile; n = 10) or not (infertile; n = 21). Sperm aneuploidy assessment by copy number variant (CNV) analysis with WES were carried out on ejaculated spermatozoa. Gene mutation profiles were enlisted and compared between the two patient cohorts to identify genes involved.

Participants/materials, setting, methods

DNA was extracted and amplified from at least 500 spermatozoa (DNA concentration, 760±486 ng/ul; quality, 1.7±0.1 nm) for CNV analyses by WES. Mutations corresponding to the CNV were then annotated and assessed using the CLC Genomic Server 9.0. Genes were considered duplicated or deleted when their read depth was >1.5 or < 0.5 times the median read depth in the control, respectively.

Main results and the role of chance

All couples (n = 31) (maternal age, 37.6±3yrs; paternal age, 39.7±5yrs) had adequate semen parameters (concentration, 59.2±30x106/mL, 44.8±18% motility, normal morphology) and normal peripheral karyotypes.

The fertile cohort (n = 10) underwent 12 ICSI cycles, achieving an 82.6% (57/69) fertilization rate with 10/12 (83.3%) cycles resulting in live births. The infertile cohort (n = 21) underwent 25 ICSI cycles, achieving a 68.4% (91/133) fertilization rate and 6/14 (42.9%) clinical pregnancies, all resulting in pregnancy loss. CNV analysis indicated lower sperm aneuploidy in the fertile (4.0% vs. 8.4%) cohort (P < 0.00001). In both cohorts, mutations associated with sperm–egg fusion (ADAM3A) and acrosomal development (SPACA1, SPATA16) were identified, justifying ICSI utilization.

The infertile cohort included complete fertilization failure, poor early embryo development, implantation failure, or pregnancy loss. Couples with complete fertilization failure (n = 4) had gene deletions (PLCZ1, PIWIL1, ADAM15) indicating sperm-related oocyte-activating deficiency. Those with poor early embryo development (n = 5) had mutations essential for centrosome integrity (HAUS1) and spindle/microtubular stabilization (KIF4A, XRN1). Couples who failed to achieve pregnancy (n = 7) had mutations commonly implicated in embryonic implantation (IL9R) and microtubule/centrosomal integrity (MAP1S). Those with pregnancy losses (n = 5) displayed mutations related to trophoblast development (NLRP7), cell cycle regulation (MARK4, TRIP13, DAB2IP, KIF1C), and a gene linked to recurrent miscarriage (TP53).

Limitations, reasons for caution

Using WES, we were able to identify germline mutations that appear to be involved in various aspects of human reproduction. These findings are new and should be validated in a larger study population. Moreover, although we attempted to control for maternal age, we still cannot exclude confounding female factors.

Wider implications of the findings

Evaluating the sperm genome can help identify elusive genetic factors associated with reproductive competence and help guide treatment options for couples unable to conceive who undergo ART. Therefore, screening spermatozoal DNA may serve as an additional tool in precision medicine to identify and treat subtle male factor infertility.

Trial registration number

N/A

P-107 A Novel Sperm Selection Technique for Embryos of the Desired Sex

Study question

Can a novel sperm selection technique (GST) yield higher rates of embryos and offspring of the desired sex in couples undergoing ICSI with PGT-A?

Summary answer

GST consistently enriched spermatozoa, resulting in a higher proportion of embryos and offspring of the desired sex without impairing clinical outcomes or offspring health.

What is known already

Although various methods to select sex-specific spermatozoa have been proposed over the years, many of these techniques have been shown to have varying degrees of success in addition to being time-consuming and costly. Moreover, the use of fluorescence and electrical charges in some of these methods has raised concerns about their potential contribution to congenital malformations. Here, we tested a novel sperm selection method aimed at achieving a higher proportion of embryos of the desired sex, without compromising clinical outcome or offspring health.

Study design, size, duration

Over a 6-year period, ejaculates from male partners of couples (n = 109) undergoing ICSI with PGT-A were processed using GST to enrich spermatozoa for the couples’ preferred sex. Standard sperm processing was carried out for couples undergoing ICSI exclusively to assess conceptus aneuploidy, comprising the control group (n = 1,261). The proportion of male and female spermatozoa in the initial and selected specimens, PGT-A results, and ICSI outcomes were compared between the two groups.

Participants/materials, setting, methods

A total of 1,370 couples were treated in 2,483 ICSI cycles. Standard sperm processing was performed for 1,261 couples who did not have an offspring sex preference. For 109 consenting couples, GST was used to enrich spermatozoa for their desired sex (IRB 1306014043). To confirm sex enrichment, ≥1,000 sperm cells were screened by fluorescent in-situ hybridization (FISH) for 9 chromosomes. The couples’ PGT-A results and ICSI outcomes were compared between the control and GST cohorts.

Main results and the role of chance

For the control cohort (n = 1,261), ejaculates were processed in the standard fashion. Spermatozoa sex ratio was unaffected. These couples (maternal age, 37.1±4yrs; paternal age, 39.1±6yrs) underwent 2,356 ICSI cycles (1.2±1), yielding an 80.9% fertilization rate (14,830/18,321). PGT-A results confirmed that 46.6% (n = 760) of their embryos were female and 53.4% (n = 872) were male. They achieved a 76.3% (725/950) implantation rate and a 64.9% (617/950) clinical pregnancy rate resulting in 569 healthy deliveries (48% female, 52% male).

From the study cohort (n = 109), 60 couples desired a female and 49 desired a male child. Those who desired female offspring (maternal age, 37.9±4yrs; paternal age, 40.8±6yrs) obtained an 81.6% sperm sex enrichment, per FISH. They underwent 74 ICSI cycles and achieved a 77.6% (592/763) fertilization rate resulting in 78.1% (235/301) female embryos that generated a 79.3% (23/29) implantation rate, yielding 16 singleton deliveries of healthy female offspring that are developing normally.

The 49 couples (maternal age, 37.6±3yrs; paternal age, 40.8±5yrs) preferring male offspring obtained an 80.8% sperm sex enrichment. They underwent 53 ICSI cycles and achieved a 74.7% (481/644) fertilization rate with an equivalent proportion of male embryos (231/292, 79.1%). Their implantation rate was 90.9% (20/22), yielding 14 healthy male singletons, all developing normally.

Limitations, reasons for caution

Although our sperm sex selection method does not guarantee offspring of a specific sex, it allowed couples participating in the study to obtain a greater proportion of conceptuses of their desired genotype. This method does not aim to replace PGT-A, but rather reduce embryo wastage.

Wider implications of the findings

Semen specimens processed by GST yielded satisfactory fertilization and embryo development, comparable to those from the control cohort. Moreover, offspring health was not negatively affected. These encouraging findings indicate that our method is safe and can consistently enrich for the desired embryo sex in a reliable and ethically palatable manner.

Trial registration number

n/a

O-311 Evaluating the Reproductive Potential of Azoospermic Men by Profiling the Genome of Surgically Retrieved Spermatozoa

Study question

Can whole exome sequencing of surgically retrieved spermatozoa from azoospermic men pinpoint mutations related to the etiology of their infertility and ability to support pregnancy?

Summary answer

Identifying key germline mutations involved in spermatogenesis helps explain reproductive failure, regardless of the etiology of the azoospermia.

What is known already

Azoospermia accounts for approximately 15% of male factor infertility cases. Although it can be caused by pre-testicular factors, the most recognized forms are testicular and post-testicular. Post-testicular azoospermia is mainly attributed to a mechanical obstruction, whereas testicular azoospermia, the most challenging form, is characterized by scattered functional germinal epithelia that may fail to support the meiotic process during sperm development. To elucidate the etiology of this condition, genetic studies on somatic cells have been carried out. Here, we perform whole exome sequencing (WES) on surgically retrieved spermatozoa to preferentially detect germline mutations that may be passed on to offspring.

Study design, size, duration

Over 3 years, we recruited patients undergoing epididymal sperm aspiration for acquired obstructive azoospermia (OA; n = 19) or testicular biopsy for nonobstructive azoospermia (NOA; n = 11). Eight men were included as fertile controls. Copy number variants (CNVs) and gene mutation profiles were obtained through WES and compared between the OA and NOA cohorts, followed by sub-analyses within those two categories according to whether they generated a clinical pregnancy (fertile) or not (infertile), while controlling for maternal age.

Participants/materials, setting, methods

Spermatozoal DNA was extracted and amplified from the surgically retrieved specimens (concentration, 742±520 ng/ul; quality, 1.7±0.1 nm). CNVs and gene mutations were detected using CLC Genomic Server 9.0. Genes were considered duplicated or deleted when the read depth was >1.5 or < 0.5 times the median read depth in the control. Common mutations were compared between the OA and NOA cohorts, as well as according to the couples’ clinical outcomes. Female partners had negative infertility workups.

Main results and the role of chance

Of 30 men (paternal age, 42.3±7yrs), 19 OA men underwent epididymal sperm retrievals (concentration, 1.1±4x106/ml, 9±12% motility), while 11 NOA men underwent testicular biopsies (concentration, 0.03±0.4x106/ml, 0.5±1% motility). WES did not indicate a significant difference in sperm aneuploidy between the two etiologies (OA, 1.7%; NOA, 1.8%) compared to the control (1.1%).

In OA patients, only 3 housekeeping-related genes were deleted, while in the NOA cohort, 5 genes involved in RNA transcription (POLR2L), apoptosis (AP5M1), and basic spermiogenic functions (AP1S2, AP1G2, APOE) were deleted.

OA patients and their partners (maternal age, 36.8±4yrs) underwent 19 ICSI cycles resulting in a delivery rate of 47.4% (9/19). Those able to reproduce (n = 9) shared a mutation in ZNF749, specifically affecting sperm production. The infertile men (n = 10) all shared a PRB1 deletion, controlling essential DNA replication.

NOA men and their partners (maternal age, 38.2±2yrs) underwent 11 ICSI cycles, yielding a delivery rate of 72.7% (8/11). The fertile men (n = 8) all shared a MPIG6B deletion, involved in stem cell lineage differentiation. All of their infertile counterparts (n = 3) presented gene deletions not only involved in spermato/spermio-genesis (n = 4) but, most importantly, also superimposed with those encoding early embryonic development (MBD5, CCAR1, PMEPA1, POLK, REC8, REPIN1, MAPRE3, ARL4C).  

Limitations, reasons for caution

Although maternal age was controlled for, confounding factors related to the female partner cannot entirely be excluded. While men unable to reproduce shared common gene mutations providing information about their condition, these findings still need to be confirmed in larger observations.

Wider implications of the findings

By performing WES, we were able to identify specific mutations associated with compromised embryo developmental competence of surgically retrieved spermatozoa. DNA sequencing technologies help identify gametes capable of sustaining a pregnancy even in the most severe form of male infertility, laying the groundwork for precision medicine in this field.

Trial registration number

N/A

O-044 ICSI in the lab: from vintage to AI

With the advent of in vitro fertilization (IVF) by Patrick Steptoe and Bob Edwards in the late 70s, the first conception outside of the human body resulted in the birth of Louise Brown. Although a terrific success, limitations of IVF surfaced, represented by the unexpected complete fertilization failure with suboptimal or dysfunctional spermatozoa.

This prompted curiosity toward individual spermatozoa for a deeper understanding of its role aimed at enhancing the interaction between complementary gametes. Techniques were designed to manipulate the oocytes, such as stripping, partially digesting, or cracking the zona pellucida (ZP). These methods were palliative solutions to overcome fertilization failure and were often plagued by polyspermy. As a result, more direct approaches were implemented to overcome the ZP, such as subzonal injection (SUZI) that although more consistent, was still unable to overcome the shortcomings of dysfunctional spermatozoa. This laid the foundation for the utilization of ICSI that, whilst attempted by some investigators, became popular when Gianpiero Palermo serendipitously inserted one spermatozoon into the ooplasm during SUZI. Consistent fertilization then followed by injecting a cohort of oocytes by ICSI in SUZI cycles, and replacement of these embryos led to 4 pregnancies described in the first clinical ICSI report. To minimize oocyte damage, the procedure was further refined by inducing a deep invagination of the oolemma toward the 9 o’clock position, granting higher chances of post-injection survival.

What set apart ICSI from other forms of ART was that any sperm sample, regardless of quality/quantity, would yield fertilization. Indeed, ICSI is the sole insemination method used with epididymal and testicular spermatozoa and has therefore revolutionized fertility treatment of azoospermic men. Indeed, even immotile testicular spermatozoa can still fertilize and yield successful pregnancies, albeit at a lower rate than their motile counterpart. Also, for these semen sources, aggressive sperm immobilization was introduced to enhance sperm membrane permeabilization and grant optimal fertilization results.

Furthermore, ICSI has transformed the field of reproductive medicine by assisting other reproductive techniques, such as testing embryos for single gene defects to reduce the occurence of sperm DNA contamination, or overcoming the cryostress-induced changes of the ZP during cryopreservation allowing the oocyte to be fertilized at a higher rate. Oocyte cryopreservation now empowers women in their reproductive age to ordain their childbearing future.

ICSI has proven to be the ultimate technique to overcome male infertility and has broadened its indication by yielding consistent fertilization and successful pregnancies in most circumstances, ensuring that men have the chance of fathering their own progeny.

To date, ICSI is applied in several countries, and in some, is performed as the preferred/sole insemination method contributing to the birth of millions of babies worldwide. Thus far, no concerning differences have been seen in the health of ICSI versus standard IVF offspring, or even naturally conceived. In fact, it has been currently established that young adults of both genders born through ICSI retain their reproductive health.

Despite its growing popularity, ICSI does not always succeed but still provides an invaluable platform to deepen our knowledge of gamete biology and helps to investigate/overcome some of the most severe and persistent forms of infertility. For example, combined with assisted gamete treatment, ICSI allows couples plagued by sperm-bound oocyte-activation-deficiency to achieve pregnancy.

The need to increase access and curtail costs of reproductive care has led to the testing of automation in ART. This is also occurring with ICSI and to date, different automated modules have been proposed for oocyte denudation, sperm tracking, and robotic ICSI. Concurrently, there has been an interest in experimenting with artificial intelligence in the IVF laboratory to minimize human shortcomings and ensure that the best spermatozoon is chosen.

O-314 Epigenetic Profiling of Seminal Plasma in NOA Men to Predict Successful Testicular Sperm Retrieval

Study question

Can epigenetic profiling of seminal plasma be used to predict successful testicular sperm retrieval for men with non-obstructive azoospermia (NOA)?

Summary answer

Epigenetic screening of cell-free seminal RNA identified gene imbalances in NOA men, with specific correlation to those who failed to yield spermatozoa at testicular biopsy.

What is known already

Although the chance of a successful microdissection testicular sperm extraction (micro-TESE) in men with NOA can be up to 60%, the procedure may still fail to yield spermatozoa. Several factors have been proposed to predict a successful retrieval, including FSH, inhibin B, genetics, and histopathology. Although histopathology would be the most reliable of these to predict successful micro-TESE, it is equally invasive to perform. Indeed, cell-free RNA extracted from testicular biopsy specimens has been shown to be differentially expressed in infertile men according to the origin of their azoospermia, whether obstructive or nonobstructive, and in relation to a normozoospermic control.

Study design, size, duration

Over a 2-year period, we identified men in whom no spermatozoa were identified despite extensive semen analyses conducted by multiple embryologists. These patients, who were negative for Y microdeletion, subsequently underwent micro-TESE. For consenting men, we performed epigenetic analyses on their seminal plasma by RNAseq. Significant differentially expressed gene (DEG) profiles were then assessed and compared according to whether surgical sperm retrieval successfully yielded spermatozoa (+TESE) or not (-TESE).

Participants/materials, setting, methods

RNA was isolated from the ejaculates for RNAseq using a commercially available spin column kit. RNA isolates were sequenced by Illumina HiSeq at 2x150bp. An absolute log2fold change of > 1 and a P-value of < 0.05 was considered significant. DEG profiles were compared within, as well as between, the +TESE and -TESE cohorts in comparison to a donor control.

Main results and the role of chance

All 12 men (37.3±6yrs) had normal peripheral karyotypes. Six (38.0±7yrs) underwent successful testicular sperm retrievals, defining the +TESE cohort. These men exclusively shared 10 significantly imbalanced genes involved in processes such as spermatogenesis (n = 4), sperm function (n = 2), and testis development (n = 1).

For the 6 men (36.6±5 yrs) who underwent testicular sperm retrievals that failed to yield spermatozoa (-TESE), we identified 16 significantly imbalanced genes, exclusively shared by these patients. These genes are mainly involved in spermatogenesis (n = 9), sperm maturation (n = 1), and cell cycle regulation (n = 4).

We then compared the DEG profiles between the +TESE and -TESE cohorts and identified 8 imbalanced genes that were shared among all 12 NOA men.

Of interest, TPTE2 was partially (67%) expressed in patients from the +TESE group, while IGSF11-AS1 was underexpressed in all men from the -TESE group. Both of these genes are implicated in spermatogenic defects and are normally highly expressed in the testis.

Interestingly, we identified a gene (NA) that was solely and specifically underexpressed in all men from the -TESE group, yet simultaneously overexpressed in all men from the +TESE group. NA, which is well known for its role in sialic acid metabolism, is also present on the sperm acrosome.

Limitations, reasons for caution

Using non-invasive RNAseq on the seminal plasma of NOA men, we were able to identify DEGs according to whether spermatozoa were successfully retrieved or had failed retrieval with micro-TESE. Although intriguing, these are preliminary results that should be further validated in a larger study cohort.

Wider implications of the findings

RNAseq identified genes shared within the same prognostic cohort. Moreover, differential expression of some specific genes predicted micro-TESE outcome. This epigenetic assessment, carried out on the ejaculate, can therefore be used as a non-invasive biomarker tool to predict loss of spermatogenesis in NOA men, sparing them from unnecessary surgery.

Trial registration number

N/A

P-270 Assisted gamete treatment to pinpoint acquired meiotic maturity and overcome oocyte activation deficiency contributed by both gametes

Study question

How can we treat couples with complete and persistent fertilization failure with ICSI linked to a combination of oocyte- and sperm-related oocyte activation deficiency (OAD)?

Summary answer

By targeting spindle presence, we optimized oocyte response to chemical activation and enhanced fertilization. Genomic assessment confirmed gamete contribution.

What is known already

Total fertilization failure occurs in 1-3% of all intracytoplasmic sperm injection (ICSI) cases. In sperm-factor OAD, the lack of phospholipase C zeta (PLCζ) prevents the spermatozoon from initiating downstream calcium oscillation in the oocyte. In these cases, assisted gamete treatment (AGT), which exposes gametes to calcium ionophore, has been adopted to artificially trigger the influx of calcium ions and has been shown to effectively improve fertilization. However, AGT is limited to triggering an intracytoplasmic calcium influx and still requires optimal ooplasmic maturity.

Study design, size, duration

Over the past 17 months, we identified couples with compromised PLCζ and reported persistent fertilization failure with ICSI despite AGT treatment. We then devised a treatment plan comprising an extended in vitro culture (IVC) to pinpoint meiotic oocyte maturity confirmed by the presence of a meiotic II spindle and followed by AGT post-ICSI. Genomic assessment was also carried out.

Participants/materials, setting, methods

Two couples with recurrent and total fertilization failure even after AGT were included. PLCζ expression was assessed using immunofluorescence on ≥ 200 cells/specimen with a 30% threshold. In the follow-up cycles, IVC was extended for at least 8 hours between retrieval and ICSI. Metaphase II spindles were visualized by Oosight®. AGT was performed by exposing both spermatozoa and oocytes to calcium ionophore. NGS was performed on spermatozoa to identify gene mutations involved in fertilization.

Main results and the role of chance

We identified 2 couples (couple A: 37-year-old female, 39-year-old male; couple B: 32-year-old female, 33-year-old male) with the following semen parameters: average volume of 2.6 ml, concentration of 82.0x106/ml, 44% motility, and normal morphology of 3%. The oocyte maturation rate was 76.3% (45/59) but resulted in zero fertilized out of a total of 45 MII oocytes injected. In-house PLCζ assessment revealed a deficiency of oocyte activation factor at 12.9%. AGT treatment alone failed to enhance fertilization on a subsequent cycle, resulting in 0% (0/8) and 5.6% (1/18) fertilization rates for couples A and B, respectively. Couple A then underwent 3 ICSI cycles with extended IVC and AGT; upon examination of nuclear maturity, 91.4% (32/35) of oocytes displayed normal metaphase II spindle and achieved an overall fertilization rate of 43.8% (14/32). To date, 12 blastocysts were cryopreserved. In couple B, 27 oocytes out of 34 retrieved presented normal metaphase II spindles after extended IVC; ICSI with AGT yielded a fertilization rate of 63.0% (17/27). All 17 zygotes were cryopreserved. Overall, our treatment improved fertilization to an overall rate of 52.5% (31/59, P  <0.00001). Genomic assessment of spermatozoa identified gene mutations involved in fertilization (ADAM15, ADAM30) and calcium channel activity (CATSPER1).

Limitations, reasons for caution

Assisted gamete treatment can enhance fertilization in cases of deficiency in PLCζ. However, chemical activation requires a responsive ooplasm that has reached meiotic maturity. These rare cases require precise diagnoses and tailored treatment techniques to address each aspect of sperm- and/or oocyte-factor OAD.

Wider implications of the findings

Our study has demonstrated the usefulness of extended IVC by targeting spindle presence to enhance chemical responses to AGT. Our findings show that although calcium ionophore can trigger the release of intracellular calcium and allow fertilization, a fully mature ooplasm is required.

Trial registration number

N/A

Analyzing cachectic phenotypes in the muscle and fat body of Drosophila larvae

Drosophila has become a popular model for examining the metabolic wasting syndrome, cachexia, characterized by degradation of muscles and fat. Here we present a protocol for quick and consistent scoring of muscle detachment, fat body lipid droplet size, and extracellular matrix (ECM) quantifications in Drosophila larvae. We detail the procedures for dissecting, staining, and imaging third instar Drosophila larval muscle fillets and fat body, and how to utilize FIJI macros for robust quantification of cachectic phenotypes in these dissected tissues.

For complete details on the use and execution of this protocol, please refer to Lodge et al. (2021).

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Detailed description of larval muscle preparation for muscle detachment analysis

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Detailed description of fat body dissection

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Quantification of fat body lipid droplet size and ECM disruption using FIJI macros

Methods to measure calcitonin receptor activity, up-regulated in cell stress, apoptosis and autophagy

The expression of the calcitonin receptor (CT Receptor) is widespread throughout the life cycle of mammals and in many diseases, and in these contexts the functions of the common isoforms is largely unknown. The relatively recent development of anti-CT Receptor antibodies that bind separate epitopes on the CT _a Receptor and CT _b Receptor isoforms has advanced our knowledge and understanding of these events. CT Receptor at the protein level is upregulated in programmed cell death including apoptosis (as described in a previous publication) and autophagy, which is discussed in our upcoming, unpublished review. Incomplete data sets are cited in this review on the upregulation of CACLR (encoding CT Receptor) mRNA, in particular the insert-positive isoform (CT _b Receptor), in response to cell stress. Cell stress is induced by growth in depleted foetal bovine serum (dFBS) or without FBS, both of which induce degrees of starvation and autophagy, or dFBS plus staurosporine, which induces apoptosis. Details of the methods deployed to generate these data are described here including measurement of the upregulation of CT _b Receptor mRNA with qPCR and nanopore long range sequencing. An anti-CT Receptor antibody also known as CalRexin ^TM, which binds an epitope in the N-terminal domain, was conjugated to either fluorophore 568, which is accumulated into apoptotic cells as previously reported, or pHrodo Red, a pH dependent fluorescent dye, which is accumulated into autophagic and apoptotic cells.  These conjugates are under development to image programmed cell death. The methods for conjugation and high content imaging on the Operetta platform are described. The high fluorescence intensity at low pH of CalRexin:pHrodo Red in both autophagic and apoptotic cells suggests localisation in autophago-lysosomes and lysosomes respectively. Overall, these observations and the methods that underpin them have contributed to our understanding of the widespread expression of CT Receptor isoforms.

O-119 Evaluating the reproductive potential of azoospermic men by germline mutation profiling

Study question

Can whole exome sequencing (WES) of spermatozoa from azoospermic men identify mutations related to the etiology of their infertility and ability to support a pregnancy?

Summary answer

Key de novo germline mutations that affect sperm production and/or embryo developmental competence may explain reproductive failure in azoospermic men, regardless of the etiology.

What is known already

Azoospermia accounts for approximately 15% of male factor infertility cases. Although it can be caused by pre-testicular factors, the most recognized forms are testicular and post-testicular. While post-testicular azoospermia is mainly due to a mechanical obstruction, testicular azoospermia, the most severe form, is characterized by scattered functional germinal epithelia that strive to support the meiotic process during gamete development. To shed light on the etiology of this condition, genetic studies have been performed, albeit exclusively on peripheral blood. We chose to perform a genomic assessment of spermatozoa to preferentially detect germline mutations that may be passed to the progeny.

Study design, size, duration

In a 2-year period, we recruited infertile men undergoing epididymal aspiration for acquired obstructive azoospermia (OA; n = 19) or testicular retrieval for nonobstructive azoospermia (NOA; n = 10). Four additional men were included as fertile controls. Following WES, copy number variants (CNVs) and gene mutation profiles were compared between the OA and NOA patients, and within those two categories, in relation to whether they generated a clinical pregnancy (fertile) or not (infertile).

Participants/materials, setting, methods

Spermatozoal DNA was extracted and amplified from the surgically retrieved specimens of consenting men (DNA concentration, 762±492 ng/ul; quality, 1.7±0.1 nm). CNVs, gene mutations, duplications, and deletions were detected using the CLC Genomic Server 9.0. Genes were considered duplicated or deleted when the read depth was >1.5 or < 0.5 times the median read depth in the control. Common mutations in the OA and NOA cohorts were assessed according to the couples’ clinical outcome.

Main results and the role of chance

Of 29 couples (maternal age, 41.9±7yrs; paternal age, 42.5±7yrs), 19 OA men underwent epididymal sperm retrieval (1.1±4x106/ml concentration, 9±12% motility) while 10 NOA men underwent testicular biopsy (0.03±0.2x106/ml concentration, 0.5±1% motility). WES did not reveal a significant difference in sperm aneuploidy between the two etiologies (OA, 1.8%; NOA, 1.9%).

In OA patients, only 3 genes were deleted, mainly housekeeping-related, while in the NOA cohort, 5 genes were deleted, involved in RNA transcription (POLR2L) and apoptosis (AP5M1), in addition to spermiogenic functions (AP1S2, AP1G2, APOE).

OA patients and their partners (maternal age, 36.8±4yrs) underwent 19 ICSI cycles that resulted in a pregnancy and delivery rate of 47.4% (9/19). Those able to reproduce (n = 9) shared a mutation in ZNF749, a gene affecting only sperm production. The infertile individuals (n = 10) all had a deletion on PRB1, controlling essential DNA replication.

NOA men and their partners (maternal age, 38.2±2yrs) underwent 10 ICSI cycles, yielding a clinical pregnancy rate of 70% (7/10). The fertile men (n = 7) had a concurrent gene deletion involved in stem cell lineage differentiation (MPIG6B). Their infertile counterparts (n = 3) had deleted genes involved in spermato/spermio-genesis (n = 6) and, most importantly, in early embryonic development (MBD5, CCAR1, PMEPA1, POLK, REC9, REPIN1, MAPRE3, and ARL4C).

Limitations, reasons for caution

This is a novel study with limited observations. The presence of housekeeping-related mutations in fertile OA men as well as the DNA replication mutation in infertile OA patients, considering the acquired condition, remains puzzling. Although maternal age was controlled for, confounding factors related to the female partner cannot be excluded.

Wider implications of the findings

Screening men for germline mutations provides valuable information on their ability to reproduce, regardless of the etiology of azoospermia. Genome profiling was able to identify reasons for failed reproductive performance in azoospermic men, particularly those individuals with secretory azoospermia (NOA). Genomic profiling may identify gametes with retained embryo developmental competence.

Trial registration number

n/a

O-094 Utilization of ultrastructural analysis and genomics of spermatozoa to better characterize subtle forms of male factor infertility

Study question

Can sequencing the sperm genome provide insight into the various forms of male factor infertility caused by sperm organelle ultrastructural defects?

Summary answer

A comprehensive genomic assessment of spermatozoal DNA is able to identify genetic causes of ultrastructural defects visualized by transmission electron microscopy (TEM).

What is known already

To evaluate a man’s reproductive potential, a conventional semen analysis through the assessment of concentration, motility, and morphology can indicate the proficiency of male gametes. Among those, conventional morphology assay can only provide indirect information on the different components of the sperm cell. The assessment of nanoscopic details such as chromatin, centriolar, mitochondrial, and axonemal components can only be observed by TEM. Indeed, TEM has been used to identify defects in the acrosome, chromatin compaction, and axonemal/periaxonemal structures. Furthermore, exome sequencing of spermatozoal DNA may identify novel causes and candidate genes for these ultrastructural defects.

Study design, size, duration

In the past 2 years, 20 men with history of fertilization failure or severe astheno-/terato-zoospermia were selected for TEM analysis of their spermatozoa, while 3 fertile men served as controls. Sperm head characteristics, intactness of fibrous sheath, and axonemal/periaxonemal structure were examined by diagnostic TEM. For consenting patients, NGS assessment was concurrently performed to identify mutations responsible for the structural abnormalities identified by TEM.

Participants/materials, setting, methods

TEM was performed on the ejaculates of 20 infertile patients and 3 fertile controls. Post-centrifugation cell pellets were resuspended, fixed, and dehydrated to be infiltrated and embedded onto the resin. Fixed specimens were sliced by ultramicrotome to 100-nm sections, then viewed by JEOL-1400 electron microscope at 300,000X magnification. At least 100 spermatozoa were evaluated by TEM. For consenting patients, DNA was extracted and amplified from at least 500 spermatozoa for concurrent NGS analysis.

Main results and the role of chance

Four types of sperm ultrastructural defects were observed, including globozoospermia, dysplasia of fibrous sheath (DFS), proximal centriole defect, and primary ciliary dyskinesia (PCD). One combined case of globozoospermia and DFS was identified. In globozoospermic patients (n = 13), 97-100% of the spermatozoa displayed characteristic spherical heads with absence of acrosomes, dispersed chromatin, and perinuclear theca deformities. Centrosomal and axonemal structures were conserved. NGS identified gene deletions (DPY19L, PICK1, SPATA16) directly related to the globozoospermic phenotype. In patients with DFS (n = 4), complete absence of flagellum was observed in 90-100% of spermatozoa. These defective gametes also displayed mitochondria disorganization, microtubular deformities, and cytoplasmic residues containing coiled flagellum with deformed capitulum within the plasma membrane. Contrary to the globozoospermia, acrosomes and nuclei appeared normal, indicating incomplete late spermiogenesis. Indeed, NGS confirmed gene deletions involved in flagellar development/function (AKAP4, SPAG16, CATSPER1). For the patient with proximal centriole defect (n = 1), sperm nucleus, fibrous sheath, and flagellar structure were conserved. However, 90% of proximal centrioles assessed exhibited microtubular disorganization, confirmed by ODF2 mutation per NGS. In the PCD patient (n = 1), chaotic flagellar microtubule arrangement and absence of outer dynein arms were prevalent in 90% of axonemal cross-sections examined, which was explained by a DNAH5 gene deletion.

Limitations, reasons for caution

While TEM can overcome the limitations of conventional semen analysis by providing direct visualization of the inner organelle arrangement of spermatozoa to accurately diagnose rare sperm pathologies, it is not routinely applied in clinics due to its high cost and technical specifications. Therefore, confirmatory NGS can provide additional diagnostic value.

Wider implications of the findings

Ultrastructural analysis with a concurrent genomic assessment characterized phenotypes and genotypes of rare sperm pathologies in infertile men. The utilization of TEM, corroborated by genomic assay, is therefore crucial for clinical and translational reproductive medicine to better characterize male factor infertility.

Trial registration number

N/A

Residual lymph node tumour burden following removal of a single axillary sentinel lymph with macrometastatic disease in women with screen-detected invasive breast cancer

Background

Women with screen-detected invasive breast cancer who have macrometastatic disease on axillary sentinel lymph node biopsy (SLNB) are usually offered either surgical axillary node clearance (ANC) or axillary radiotherapy. These treatments can lead to significant complications for patients. The aim of this study was to identify a group of patients who may not require completion ANC.

Methods

Data from the NHS Breast Screening Programme between 1 April 2012 and 31 March 2017 were interrogated to identify women with invasive breast carcinoma and a single sentinel lymph node (SLN) with macrometastatic disease who subsequently proceeded to completion ANC. Univariable and multivariable analyses were performed to identify patients with a single positive SLN who had no further lymph node metastasis on ANC.

Results

Of the 2401 women included in the cohort, the presence of non-sentinel node disease was significantly affected by: the number of nodes obtained at SLNB (odds ratio (OR) 0.49 for retrieval of more than 1 node), invasive size of tumour (OR 1.63 for size greater than 20 mm), surgical treatment (OR 1.34 for mastectomy), human epidermal growth factor receptor (HER) 2 status (OR 0.71 for HER2 positivity), and patient age (OR 1.10 for age less than 50 years; OR 1.46 for age greater than 70 years). Patients aged less than 70 years, with tumour size smaller than 2 cm, more than one node retrieved on SLNB, and who had breast-conserving surgery had a lower chance of positive non-sentinel nodes on completion ANC compared with other patients.

Conclusion

This study, of a purely screen-detected breast cancer cohort, identified a subset of patients who may be spared completion ANC in the event of a single axillary SLN with macrometastasis.

SIDT1 Localizes to Endolysosomes and Mediates Double-Stranded RNA Transport into the Cytoplasm

dsRNA is a common by-product of viral replication and acts as a potent trigger of antiviral immunity. SIDT1 and SIDT2 are closely related members of the SID-1 transmembrane family. SIDT2 functions as a dsRNA transporter and is required to traffic internalized dsRNA from endocytic compartments into the cytosol for innate immune activation, but the role of SIDT1 in dsRNA transport and in the innate immune response to viral infection is unclear. In this study, we show that Sidt1 expression is upregulated in response to dsRNA and type I IFN exposure and that SIDT1 interacts with SIDT2. Moreover, similar to SIDT2, SIDT1 localizes to the endolysosomal compartment, interacts with the long dsRNA analog poly(I:C), and, when overexpressed, enhances endosomal escape of poly(I:C) in vitro. To elucidate the role of SIDT1 in vivo, we generated SIDT1-deficient mice. Similar to Sidt2^-/- mice, SIDT1-deficient mice produced significantly less type I IFN following infection with HSV type 1. In contrast to Sidt2^-/- mice, however, SIDT1-deficient animals showed no impairment in survival postinfection with either HSV type 1 or encephalomyocarditis virus. Consistent with this, we observed that, unlike SIDT2, tissue expression of SIDT1 was relatively restricted, suggesting that, whereas SIDT1 can transport extracellular dsRNA into the cytoplasm following endocytosis in vitro, the transport activity of SIDT2 is likely to be functionally dominant in vivo.

The Single Nucleotide Polymorphism Mal-D96N Mice Provide New Insights into Functionality of Mal in TLR Immune Responses

MyD88 adaptor-like (Mal) protein is the most polymorphic of the four key adaptor proteins involved in TLR signaling. TLRs play a critical role in the recognition and immune response to pathogens through activation of the prototypic inflammatory transcription factor NF-κB. The study of single nucleotide polymorphisms in TLRs, adaptors, and signaling mediators has provided key insights into the function of the corresponding genes but also into the susceptibility to infectious diseases in humans. In this study, we have analyzed the immune response of mice carrying the human Mal-D96N genetic variation that has previously been proposed to confer protection against septic shock. We have found that Mal-D96N macrophages display reduced cytokine expression in response to TLR4 and TLR2 ligand challenge. Mal-D96N macrophages also display reduced MAPK activation, NF-κB transactivation, and delayed NF-κB nuclear translocation, presumably via delayed kinetics of Mal interaction with MyD88 following LPS stimulation. Importantly, Mal-D96N genetic variation confers a physiological protective phenotype to in vivo models of LPS-, Escherichia coli-, and influenza A virus-induced hyperinflammatory disease in a gene dosage-dependent manner. Together, these results highlight the critical role Mal plays in regulating optimal TLR-induced inflammatory signaling pathways and suggest the potential therapeutic advantages of targeting the Mal D96 signaling nexus.

A DIE responsive NIR-fluorescent cell membrane probe

It is challenging to achieve selective off to on modulation of the emissive state of a fluorophore within a complex and heterogeneous cellular environment. Herein we show that the dis-assembly of a non-fluorescent aggregate to produce individual fluorescent molecules, termed disaggregation induced emission (DIE), can be utilised to achieve this goal with an amphiphilic BF₂-azadipyrromethene (NIR-AZA) probe. Optical near-infrared properties of the NIR-AZA probe used in this study include absorption and emission maxima at 700 and 726 nm respectively when in the emissive non-aggregated state. Key to the success of the probe is the bis-sulfonic acid substitution of the NIR-AZA fluorophore, which is atypical for membrane probes as it does not contain zwitterionic lipid substituents. The aggregation/disaggregation properties of the NIR-fluorophore have been investigated in model surfactant and synthetic liposomal systems and shown to be emissive responsive to both. Real-time live cell imaging experiments in HeLa Kyoto and MC3T3 cells showed a rapid switch on of emission specific to the plasma membrane of viable and apoptotic cells attributable to a disaggregation-induced emission of the probe. Image analysis software confirmed localisation of fluorescence to the plasma membrane. Cell membrane staining was also effective for formaldehyde fixed cells, with staining possible either before or after fixation. This study adds new and important findings to recent developments of DIE responsive probes and further applications of this controllable emission-switching event are anticipated.