P-090 Genotypic sperm sorting: A less invasive Assisted Reproductive Technology (ART) to prevent genetic disorders in newborns

Study question

Is the prevention of genetic disorders in newborns possible by genotypically sorting sperm cells with specially characterized proteins on the sperm surface membrane?

Summary answer

For Cystic Fibrosis and X-linked Disorders prevention model, we utilized certain monoclonal antibodies to sort sperm cells by targeting proteins expressed on their surface membrane.

What is known already

Our study focused on Cystic Fibrosis (CF) and X-linked Diseases (XLD) which are genetic disorders inherited by offspring from parents who are healthy carriers of the autosomal recessive or allosomal genes. More than 10million Caucasians are healthy carriers of a mutant cystic-fibrosis gene (predominantly F508del) while 4% of all newborns are at risk of being born with an X-linked disease. The current clinically approved mitigation plan for preventing such genetic disorders in newborns – is to consider Preimplantation Genetic Testing for Monogenetic diseases (PGT-M). PGT-M involves an invasive microsurgical procedure that requires the removal of cells from 3-5day old embryos.

Study design, size, duration

For our study design, semen samples purchased from FairFax Cryobank from an anonymous CF-carrier and a non-carrier were utilized. The samples were assessed for the presence of H-Y male antigen and the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, which are both selectively expressed on the sperm surface – to delineate genotypic sperm sort models for XLD and CF respectively.

Participants/materials, setting, methods

Methods utilized in the genotypic sperm sorting protocols included the use of phycoerythrin (PE) binding Tetrameric Antibody Complexes (TAC) coupled with magnetic beads. Immuno-magnetic sorting was conducted with a conventional sort method in tubes and with specially fabricated microfluidic sperm sorting (MSS) chips. Sort yield and purities of positively selected sperm populations were assessed by flow cytometry, immunofluorescence, fluorescent in situ hybridization (FISH) and by quantitative-PCR (qPCR – Cq & Tm).

Main results and the role of chance

Our study was able to elucidate a potential less invasive clinical “ART” application or method of genotypically sorting sperm cells with H-Y/CFTR monoclonal-antibody-functionalized microfluidic chips or conventional immuno-magnetic sorting protocols in sort tubes. Preliminary assessments showed that flow cytometry may be utilized to confirm sort purities of positively selected sperm populations (with HY or CFTR markers) from immuno-magnetic sort tubes – based on their morphological and cellular characteristics. For a genotypic sperm sort in the pathogenic CF-carrier sample, positively and negatively selected CF-sperm fractions (being CFTR-Wt and F508del-Mut sperm) from immuno-magnetic sort tubes could not be adequately distinguished by qPCR-Cq – because of their intrinsic and slightly insignificant genetic variabilities. However, the microfluidic sperm sorting chip fabricated for this study enabled a differential and positive immuno-magnetic selection of CFTR-Wt sperm with a comparably higher but statistically insignificant sort yield, relative to the population of the F508del-Mut sperm negatively selected – when assessed by qPCR-Cq (p value = 0.092; significant at < 0.05). Immunofluorescence and FiSH evaluations of genotypically sorted sperm cells in both XLD and CF models also showed pictorial comparisons with the observed genetic assessment outcomes.

Limitations, reasons for caution

One of the limitations of this study is the immuno-magnetic sort efficiency. The sorting efficiency may however be improved if freshly collected normospermic semen samples were utilized rather than a frozen-thawed sample which may have been subjected to the stress of cryopreservation and potential cellular damage with reduced motility.

Wider implications of the findings

This novel less invasive method of Assisted Reproductive Technology may also usher in a new “ART” called Intra-cytoplasmic Genotypically-selected Sperm Injection (IGSI). The IGSI method would potentially enable the selection of non-diseased sperm cells – for the sole purpose of helping to prevent genetic disorders in newborns.

Trial registration number

Not Applicable

Emerging technologies for home-based semen analysis

With about 70 million cases of infertility worldwide, half of which are caused by male factors, sperm analysis is critical to determine male fertility potential. Conventional semen analysis methods involve complex and manual inspection with a microscope, and these methods are labor intensive and can take several days. Due to unavailability of rapid, convenient, and user-friendly semen analysis tools, many men do not seek medical evaluation, especially in resource-constrained settings. Furthermore, as conventional methods have to be conducted in the laboratories, many men are unwilling to be tested as a result of social stigma in certain regions of the world. One solution can be found in at-home sperm analysis, which allows men to test their semen without the hassle of going to and paying for a clinic. Herein, we examine current at-home sperm analysis technologies and compare them to the traditional laboratory-based methods. In addition, we discuss emerging sperm analysis approaches and describe their limitations and future directions.

Cardiovascular effect of inflammation and nonsteroidal anti-inflammatory drugs on renin-angiotensin system in experimental arthritis

A co-morbidity of inflammatory conditions is increased cardio-renal risks. Additionally, nonsteroidal anti-inflammatory drugs (NSAIDs) which are used to treat pain and inflammation are also associated with increase in such risks. We hypothesized that inflammation and NSAIDs impose the cardio-renal risk through the activation of the renin-angiotensin-system (RAS), a regulating pathway of the renal and cardiovascular homeostasis. We investigated the effect of adjuvant arthritis and NSAIDs on the RAS. Western blotting and ELISA were used to measure the RAS components. Inflammation caused significant imbalances in the cardiac and renal angiotensin converting enzymes, their biologically active angiotensin peptides (AngII and Ang1-7) and the target proteins involved in the peptide-receptor binding (AngII type 1 and type 2, and Ang1-7 receptor, Mas) toward cardio-renal toxicity. However, 7 days treatment of arthritic animals with NSAIDs (rofecoxib, meloxicam, celecoxib and flurbiprofen) restored the constitutive balances, perhaps due to their anti-inflammatory properties. Inflammation exerts its cardio-renal effects by causing imbalance in the RAS. NSAIDs through their anti-inflammatory effect restore this imbalance. Thus, mechanisms other than imbalances in the RAS may be involved in the NSAIDs cardiotoxicity.

Evaluation of bone targeting salmon calcitonin analogues in rats developing osteoporosis and adjuvant arthritis

Synthetic analogues of the peptide hormone calcitonin have been used in medicine as biologic drug therapies for decades, to treat pathological conditions of excessive bone turnover, such as osteoporosis, where more bones are removed than replaced during bone remodeling. Osteoporosis and other chronic skeletal diseases, including inflammatory arthritis, exact a substantial and growing toll on aging populations worldwide however they respond poor to synthetic biologic drug therapy, due in part to the rapid half-life of elimination, which for calcitonin is 43 minutes. To address those shortcomings, we have developed and synthesized bone-targeting variants of calcitonin as a targeted drug delivery strategy, by conjugation to bisphosphonate drug bone-seeking functional groups in highly specific reaction conditions. To evaluate their in vivo efficacy, bisphosphonate-mediated bone targeting with PEGylated (polyethylene glycol conjugated) and non-PEGylated salmon calcitonin analogues were synthesized and dose escalation was performed in female rats developing Osteoporosis. The bone-targeting calcitonin analogues were also tested in a separate cohort of male rats developing adjuvant-induced arthritis. Ovariectomized female rats developing Osteoporosis were administered daily sub-cutaneous injection of analogues equivalent to 5, 10 and 20 IU/kg of calcitonin for 3 months. Adjuvant arthritis was developed in male rats by administering Mycobacterium butyricum through tail base injection. Daily sub-cutaneous injection of analogues equivalent to 20 IU/kg of calcitonin was administered and the rats were measured for visible signs of inflammation to a 21 day endpoint. In both studies, the effect of drug intervention upon bone volume and bone mineral density (BMD) was assessed by measuring the trabecular bone volume percentage and BMD at the proximal tibial metaphysis using in vivo micro-computed tomography. With dose escalation studies, only bone targeting analogue dosed groups showed a trend towards increased BMD and bone volume at 4, 8 and 12 weeks. Significant preservation of bone volume and BMD as evidenced by nonsignificant (P<0.05) loss of bone volume and BMD at the end of 3 month study endpoint was seen in animals dosed with 20 IU/kg of calcitonin compounds. Similarly, in case of adjuvant-induced arthritis rats, there was a significant increase (P<0.05) in bone volume and BMD in calcitonin-bisphosphonate and calcitonin-PEG-bisphosphonate treated groups at 21 days compared to the baseline values. Improved efficacy in terms of preserving bone volume and BMD in Osteoporosis, and in rats developing adjuvant-induced arthritis, by these analogues suggests their potential as new drug candidates for further evaluation to determine their usefulness in bone diseases characterized by excessive bone resorption.

Comparative efficacy of esomeprazole and omeprazole: Racemate to single enantiomer switch

Background

Both omeprazole and its S enantiomer (esomeprazole) have been available and used to treat  symptoms of gastroesophageal reflux disease (GERD) and conditions associated with excessive stomach acid secretion for more than a decade. Controversy exists over improved efficacy of S enantiomer (esomeprazole) over parent racemate (omeprazole). However, a comparison of the clinical outcomes of these products may reveal the rationale for switching from the racemate to single enantiomer. Since enantiomers of omeprazole are equipotent, we compared the outcomes of equal doses of each product to see if both actually differ in their efficacy’s or the reported superiority of S enantiomer is just a dose effect.

Methods

A web search was carried out for randomized controlled trials with head-to-head comparisons of omeprazole and S-omeprazole. The data were abstracted and after calculating theodd ratios (OR) for the outcomes reported in each study, the combined overall odd ratios (OR’) were estimated. The random effect inverse variance method with omeprazole as the reference (OR” = 1) was used.

Results

Out of 1171 studies, 14 were deemed eligible. There was no significant difference in the therapeutic success between omeprazole and S-omeprazole as a part of triple therapy for the treatment of H. pylori in both intention-to-treat (OR’, 1.06; CI, 0.83, 1.36; p = 0.63) as well as per-protocol analysis (OR’, 1.07; CI, 0.84, 1.36; p = 0.57). For the treatment of gastro-oesophageal reflux disease, S-omeprazole was significantly but marginally superior to the racemate (OR’, 1.18; CI, 1.01, 1.38; p = 0.04). The two products were equipotent in all metrics used to assess intragastric pH except for the % patients maintaining a 24 h gastric pH above 4 (1.57; CI, 1.04, 2.381; p = 0.03).

Conclusion

The therapeutic benefit of chiral switch of omeprazole is questionable considering the substantially greater economic burden involved.

The effect of COX-2-selective meloxicam on the myocardial, vascular and renal risks: a systematic review

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to increase the risk of cardiovascular (CV) and renal incidences, especially at higher doses and upon long term use. However, the available reports are criticized for lack of specificity, grouping of vastly different outcomes together and ignoring the heterogeneity among NSAIDs. In this systematic review, we are reporting CV/renal risks associated with meloxicam, stratified into myocardial, vascular, renal risk categories, to address the differential nature of NSAIDs effects on different body systems. We are also reporting composite CV/renal risk to present overall risk associated with various covariates.

METHODS

We searched the online healthcare databases for observational studies or randomized controlled trials, reporting myocardial or all-cause mortality outcome (>90 days exposure) and/or vascular/renal outcomes (any exposure) after meloxicam use, published until April 2014. The combined odd ratio values (OR'; 95% CI) were calculated using the random effect inverse variance model.

RESULTS

We found 19 eligible studies out of 2,422 reports. Meloxicam demonstrated a low increase in composite risk (OR' 1.14; CI 1.04-1.25) which was mainly vascular in nature (OR' 1.35; CI 1.18-1.55] as it did not elevate myocardial (OR' 1.13; CI 0.98-1.32) or renal (OR', 0.99; CI 0.72-1.35) risks. Relative to meloxicam, other NSAIDs increased the composite risk, in a dose-dependent fashion, in the following order: rofecoxib > indomethacin > diclofenac > celecoxib > naproxen > ibuprofen. OR' was also influenced by type of disease and the comparator used, and acetylsalicylic acid.

CONCLUSION

NSAIDs are heterogeneous in increasing CV/renal risks. The low increased risk associated with meloxicam is mainly vascular in origin.

Adverse effects of nonsteroidal antiinflammatory drugs: an update of gastrointestinal, cardiovascular and renal complications

Non-steroidal anti-inflammatory drugs (NSAIDs) are used chronically to reduce pain and inflammation in patients with arthritic conditions, and also acutely as analgesics by many patients. Both therapeutic and adverse effects of NSAIDs are due to inhibition of cyclooxygenase (COX) enzyme. NSAIDs are classified as non-selective and COX-2-selective inhibitors (COXIBS) based on their extent of selectivity for COX inhibition. However, regardless of their COX selectivity, reports are still appearing on the GI side effect of NSAIDs particularly on the lower gastrointestinal (GI) tract and the harmful role of their controlled release formulations. In addition, previously unpublished data stored in the sponsor's files, question the GI sparing properties of rofecoxib, a COXIB that has been withdrawn due to cardiovascular (CV) side effects. Presently, the major side effects of NSAIDs are the GI complications, renal disturbances and CV events. There is a tendency to believe that all NSAIDs are associated with renal and CV side effects, a belief that is not supported by solid evidence. Indeed, lower but still therapeutics doses of some NSAIDs may be cardioprotective. In this review, we briefly discuss the GI toxicity of the NSAIDs and assess their renal and CV adverse effects in more detail.

Glucosamine dose/concentration-effect correlation in the rat with adjuvant arthritis

There is a debate on the dose dependency, concentration-effect, hence, the beneficial effect of glucosamine (GlcN), a widely used anti-inflammatory natural product. We investigated dose/concentration-effect relationship and determined its minimum effective dose/concentration in rats with adjuvant arthritis (AA, Mycobacterium butyricum in squalene) both as preventive and ameliorating interventions. To control already emerged arthritis, rats received oral doses of placebo or 160 mg/kg.day(-1) GlcN for 6 days. For prevention, rats were orally administered 0, 20, 40, 80, or 160 mg/kg.day(-1) GlcN commencing on the day of adjuvant injection. The arthritis index (AI), serum nitrite, and body weight were recorded. Subsequently, animals were cannulated in the right jugular veins and blood samples were collected for the determination of GlcN. GlcN ameliorated and, dose-dependently, prevented AA. It also controlled nitrite. AI was inversely correlated with GlcN dose, maximum plasma concentration, and the area under the concentration curve. Minimum effective dose was approximately 40 mg/kg.day(-1) that correspond to maximum plasma concentration of 1.37 ± 0.24 mg/L, close to 1.6 mg/L reported for pharmaceutical grades of GlcN to humans. GlcN efficacy is dose and concentration dependent. If the data extrapolated to humans, a higher than the commonly tested 1500 mg/kg dosage regimen may provide more clear treatment outcomes.