Browsing by Author "Du Plessis, Stefan"

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Computational Analysis of Short Linear Motifs in the Spike Protein of SARS-CoV-2 Variants Provides Possible Clues into the Immune Hijack and Evasion Mechanisms of Omicron Variant
(2022-08) Soorajkumar, Anjana; Alakraf, Ebrahim; Uddin, Mohammed; Du Plessis, Stefan; Alsheikh-Ali, Alawi; Kandasamy, Richard K
Abstract: Short linear motifs (SLiMs) are short linear sequences that can mediate protein–protein interaction. Mimicking eukaryotic SLiMs to compete with extra- or intracellular binding partners, or to sequester host proteins is the crucial strategy of viruses to pervert the host system. Evolved proteins in viruses facilitate minimal protein–protein interactions that significantly affect intracellular signaling networks. Unfortunately, very little information about SARS-CoV-2 SLiMs is known, especially across SARS-CoV-2 variants. Through the ELM database-based sequence analysis of spike proteins from all the major SARS-CoV-2 variants, we identified four overriding SLiMs in the SARS-CoV-2 Omicron variant, namely, LIG_TRFH_1, LIG_REV1ctd_RIR_1, LIG_CaM_NSCaTE_8, and MOD_LATS_1. These SLiMs are highly likely to interfere with various immune functions, interact with host intracellular proteins, regulate cellular pathways, and lubricate viral infection and transmission. These cellular interactions possibly serve as potential therapeutic targets for these variants, and this approach can be further exploited to combat emerging SARS-CoV-2 variants.
The Effect of Rooibos (Aspalathus linearis), Honeybush (Cyclopia intermedia) and Sutherlandia (Lessertia frutescens) on Testicular Insulin Signalling in Streptozotocin-Induced Diabetes in Wistar Rats
(2021) Omolaoye, Temidayo S; Du Plessis, Stefan
Background: Testicular insulin signalling is altered in diabetic (DM) males. While unravelling the mechanism through which DM exert these detrimental effects, studies have shown the importance of insulin regulation in glucose homeostasis, and how a lack in insulin secretion indirectly led to reduced male fertility. The current study aimed to investigate the role of rooibos, honeybush and Sutherlandia on insulin signalling in the testicular tissue of type I diabetic rats. Methods: Animals (n=60) were randomly divided into six groups. The groups include a control group, a vehicle group, and diabetes was induced in the remainder of animals via a single intraperitoneal injection of STZ at 45mg/kg. The remaining four groups included a diabetic control (DC), diabetic + rooibos (DRF), diabetic + honeybush (DHB) and diabetic + Sutherlandia group (DSL). Animals were sacrificed after seven weeks of treatment, and blood and testes were collected. Results: All diabetic groups (DC, DRF, DHB, DSL) presented with a significant increase in blood glucose levels after diabetes induction compared to the control and vehicle (p<0.001). The DC animals presented with decreased testicular protein expression of IRS-1, PkB/Akt and GLUT4 compared to controls. DRF and DHB animals displayed an acute upregulation in IRS-1, while the DSL group showed improvement in IRS-2 compared to DC. Although, DRF animals presented with a decrease in PkB/Akt, DHB and DSL animals displayed upregulation (22.3%, 48%) compared to controls, respectively. Conclusion: The results taken together, it can be suggested that these infusions may enhance insulin signalling through diverse pathways
The Effect of Statins on Male Reproductive Parameters: A Mechanism Involving Dysregulation of Gonadal Hormone Receptors and TRPV1
(2023) Omolaoye, Temidayo S.; Cyril, Asha Caroline; Radhakrishnan, Rajan; Rawat, Surendra Singh; Karuvantevida, Noushad; Du Plessis, Stefan
Abstract: Statins have been shown to cause diverse male reproductive function impairment, and in some cases, orchialgia. Therefore, the current study investigated the possible mechanisms through which statins may alter male reproductive parameters. Thirty adult male Wistar rats (200–250 g) were divided into three groups. The animals were orally administered rosuvastatin (50 mg/kg), simvastatin (50 mg/kg), or 0.5% carboxy methyl cellulose (control), for a 30-day period. Spermatozoa were retrieved from the caudal epididymis for sperm analysis. The testis was used for all biochemical assays and immunofluorescent localization of biomarkers of interest. Rosuvastatin-treated animals presented with a significant decrease in sperm concentration when compared to both the control and simvastatin groups (p < 0.005). While no significant difference was observed between the simvastatin and the control group. The Sertoli cells, Leydig cells and whole testicular tissue homogenate expressed transcripts of solute carrier organic anion transporters (SLCO1B1 and SLCO1B3). There was a significant decrease in the testicular protein expression of the luteinizing hormone receptor, follicle stimulating hormone receptor, and transient receptor potential vanilloid 1 in the rosuvastatin and simvastatin-treated animals compared to the control. The expression of SLCO1B1, SLCO1B2, and SLCO1B3 in the different spermatogenic cells portray that un-bio transformed statin can be transported into the testicular microenvironment, which can subsequently alter the regulation of the gonadal hormone receptors, dysregulate pain-inflammatory biomarkers, and consequently impair sperm concentration.
Effects of space flight on sperm function and integrity: A systematic review
(2022-08) Ahrari, Khulood; Omolaoye, Temidayo S; Goswami, Nandu; Al Suwaidi, Hanan; Du Plessis, Stefan
Abstract: With the advancement in space exploration and the intention to establish an inhabitable human settlement on Mars, it is important to investigate the effects of exposure to space/microgravity and the associated radiations on procreation. Sperm function and integrity are fundamental to male reproduction and can potentially be affected by the environmental changes experienced in space. Therefore, this study was conducted to systematically gather, filter, and collate all the relevant information on the effects of spaceflight on male reproductive parameters and functions. A search was performed utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were extracted from the major electronic databases including PubMed, and other credible literature sources. MeSH search terms that were employed included "spermatozoa", "microgravity", and "ionizing radiation". The literature search did not discriminate against papers published before a certain date due to the very limited number of articles available. However, there was a restriction on the male gender and language (English). The parameters included in this study are sperm motility, total sperm count, sperm DNA fragmentation hormonal levels and testicular histology. Following a comprehensive literature search, a total of 273 articles were retrieved and screened, 252 articles were excluded due to the irrelevance to the topic, duplication, and non-original articles. A total of 21 articles met the inclusion criteria and are included in the current study. Findings from these studies showed that sperm motility was decreased after exposure to microgravity and ionizing radiation. Total sperm count was also found to be reduced by microgravity only. Sperm DNA fragmentation was increased by both ionizing radiation and microgravity. Testosterone levels and testicular weight were also decreased by microgravity. Although there is a dearth in the literature regarding the effects of microgravity and ionizing radiation on male reproductive parameters, the available findings showed that exposure to microgravity poses a risk to male reproductive health. Therefore, it is essential to develop countermeasures to either manage, treat, or prevent these consequential adverse effects. Hence, this review also highlights some potential countermeasure approaches that may mitigate the harmful effects of microgravity and associated exposures on male reproductive health.
Guinness World Record: Personal Experience and Physiological Responses of a Non-Professional Athlete Successfully Covering 620 Km in 7-Days by Foot Across the United Arab Emirates
(2022) Boillat, Thomas; Du Plessis, Stefan; Loney, Tom
Abstract: Ultra-endurance record-breaking attempts place significant metabolic, cardiovascular, and mechanical stress on the athlete. This research explores the personal experience and physiological responses of a non-professional athlete attempting the Guinness World Record of covering 620 km on foot across the United Arab Emirates in 7-days or less. The participant wore a smartwatch throughout the challenge to collect heart rate, activity, and environmental temperature data. Anthropometric, body composition, and inflammatory, haematological, and endocrine biomarkers measurements were completed pre- and post-event. A pre- and post-event interview was conducted to collect data on training and preparation, and self-reported experiences during the challenge. Despite episodes of diarrhoea, vomiting, and muscle cramps due to hypohydration during the first days of the challenge, the participant successfully completed 619.01 km in six days, 21 hours, and 47 minutes (average pace 10.11 min/km) achieving a new Guinness World Record. Body mass remained unchanged, fat mass decreased, and fat-free mass especially in the legs increased over the seven days, most likely due to water retention. Biomarkers of stress, cell damage, and inflammation increased. Haematological markers related to red blood cells decreased probably due to exercise-induced increases in plasma volume with the participant classified with mild anaemia post-event. This case study reinforces the importance of amateur athletes attempting similar ultra-endurance events adhering to a pre-planned hydration and nutrition strategy to maximise performance and minimise the risk of injury.
Introducing the 4Ps Model of Transitioning to Distance Learning: A convergent mixed methods study conducted during the COVID-19 pandemic
(2021) Otaki, Farah; Zaher, Shroque; Du Plessis, Stefan; Lakhtakia, Ritu; Zary, Nabil; Inuwa, Ibrahim M.
Abstract: Significant concern has been raised regarding the effect of COVID-19 on medical education. This study aimed to shed light on the distance learning experiences of medical students and their instructors at the Mohammed Bin Rashid University of Medicine and Health Sciences (MBRU) in Dubai, United Arab Emirates. A convergent mixed methods approach was utilized. Qualitative and quantitative data was collected using a survey of closed-ended followed by open-ended questions. The percentage of the total average of satisfaction among stakeholders was 76.4%. The qualitative analysis led to developing the 4Ps Model of Transitioning to Distance Learning, which encapsulates four interrelated themes. It would be helpful to leverage the lessons learned to tailor blended medical programs with a reasonable me´lange of experiences. The study also contributes to the mixed methods research by showcasing a means of adapting it to evaluate critical situations reliably and rapidly.
Mechanisms of SARS-CoV-2 and Male Infertility: Could Connexin and Pannexin Play a Role?
(2022) Omolaoye, Temidayo S.; Jalaleddine, Nour; Du Plessis, Stefan
Abstract: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on male infertility has lately received significant attention. SARS-CoV-2, the virus that causes coronavirus disease (COVID-19) in humans, has been shown to impose adverse effects on both the structural components and function of the testis, which potentially impact spermatogenesis. These adverse effects are partially explained by fever, systemic inflammation, oxidative stress, and an increased immune response leading to impaired blood-testis barrier. It has been well established that efficient cellular communication via gap junctions or functional channels is required for tissue homeostasis. Connexins and pannexins are two protein families that mediate autocrine and paracrine signaling between the cells and the extracellular environment. These channel-forming proteins have been shown to play a role in coordinating cellular communication in the testis and epididymis. Despite their role in maintaining a proper male reproductive milieu, their function is disrupted under pathological conditions. The involvement of these channels has been well documented in several physiological and pathological conditions and their designated function in infectious diseases. However, their role in COVID-19 and their meaningful contribution to male infertility remains to be elucidated. Therefore, this review highlights the multivariate pathophysiological mechanisms of SARS-CoV-2 involvement in male reproduction. It also aims to shed light on the role of connexin and pannexin channels in disease progression, emphasizing their unexplored role and regulation of SARS-CoV-2 pathophysiology. Finally, we hypothesize the possible involvement of connexins and pannexins in SARS-CoV-2 inducing male infertility to assist future research ideas targeting therapeutic approaches.
Mimicking Mother Nature in the Field of Human Reproduction?
(2023) Du Plessis, Stefan
Introduction: Although humans have made significant progress in understanding reproductive events, nature still has more information to reveal. Towards the end of the 19th century, humans started studying reproductive processes such as gametogenesis, fertilization, and embryo development.1 Since sperm and egg roles in fertilization were introduced in 1870 for the first time, reproductive biologists tried to emulate the natural reproductive processes despite the significant lack of knowledge regarding in vivo reproductive mechanisms. In the quest to mimic or overcome natural reproduction processes, numerous attempts have been made to produce embryos from non-germ cells.2,3 These trials ultimately culminated in the birth of Dolly the sheep4 as a result of somatic cell nuclear transfer, starting a new era of cloning or asexual reproduction. Though not fully understood at the time (1959), the work of Chang5 regarding the fertilization of rabbit ova in vitro, paved the way for the application of artificial reproductive techniques (ART) in humans. Ever since then, it has always been considered that the best evidence for these technologies to be accepted is that the progeny derived from ART are capable of reproducing naturally, especially those conceived by in vitro fertilization (IVF). Researchers have tried to ensure in vitro maturation of the spermatogonial stem cells transplanted in testes, separated into small pieces, and cultured on agarose, which migrated towards the basal membrane and settled on it, as in the in vivo process.6 On the other hand, have reported that after ovary tissue cryopreservation and orthotopic transplantation result in a 76% spontaneous pregnancy live baby rate in 119 human females 13 out 119 of these patients need also in vitro maturation of the oocytes,7 which allows to postulate that the cryopreservation of ovarian tissue could be a promising method to preserve fertility in humans. However, transformation of the experience and data obtained from animals to humans has been failing.
Monkeypox and Male Fertility: Is There Any Looming Danger?
(2022) Du Plessis, Stefan; Omolaoye, Temidayo S
Abstract: The current emergence of monkeypox virus infection, mainly reported from previously non-endemic regions, raised concerns about its transmission and possible implication on general health and wellbeing. The concern is spawned from the fact that the virus keeps spreading, and as of the 8th September 2022, at least 88 countries have reported over 54191 cases globally. In the wake of the Covid-19 pandemic, this recent outbreak is mustering up thoughts of public panic, social disruption, severe illness, and comorbidities, including risks to fertility and offspring.
Omics and Male Infertility: Highlighting the Application of Transcriptomic Data
(2022) Omolaoye, Temidayo S.; Kandasamy, Richard K; Hachim, Mahmood Yaseen; Du Plessis, Stefan; Omolaoye, Victor A
Abstract: Male infertility is a multifaceted disorder affecting approximately 50% of male partners in infertile couples. Over the years, male infertility has been diagnosed mainly through semen analysis, hormone evaluations, medical records and physical examinations, which of course are fundamental, but yet inefficient, because 30% of male infertility cases remain idiopathic. This dilemmatic status of the unknown needs to be addressed with more sophisticated and result-driven technologies and/or techniques. Genetic alterations have been linked with male infertility, thereby unveiling the practicality of investigating this disorder from the “omics” perspective. Omics aims at analyzing the structure and functions of a whole constituent of a given biological function at different levels, including the molecular gene level (genomics), transcript level (transcriptomics), protein level (proteomics) and metabolites level (metabolomics). In the current study, an overview of the four branches of omics and their roles in male infertility are briefly discussed; the potential usefulness of assessing transcriptomic data to understand this pathology is also elucidated. After assessing the publicly obtainable transcriptomic data for datasets on male infertility, a total of 1385 datasets were retrieved, of which 10 datasets met the inclusion criteria and were used for further analysis. These datasets were classified into groups according to the disease or cause of male infertility. The groups include non-obstructive azoospermia (NOA), obstructive azoospermia (OA), non-obstructive and obstructive azoospermia (NOA and OA), spermatogenic dysfunction, sperm dysfunction, and Y chromosome microdeletion. Findings revealed that 8 genes (LDHC, PDHA2, TNP1, TNP2, ODF1, ODF2, SPINK2, PCDHB3) were commonly differentially expressed between all disease groups. Likewise, 56 genes were common between NOA versus NOA and OA (ADAD1, BANF2, BCL2L14, C12orf50, C20orf173, C22orf23, C6orf99, C9orf131, C9orf24, CABS1, CAPZA3, CCDC187, CCDC54, CDKN3, CEP170, CFAP206, CRISP2, CT83, CXorf65, FAM209A, FAM71F1, FAM81B, GALNTL5, GTSF1, H1FNT, HEMGN, HMGB4, KIF2B, LDHC, LOC441601, LYZL2, ODF1, ODF2, PCDHB3, PDHA2, PGK2, PIH1D2, PLCZ1, PROCA1, RIMBP3, ROPN1L, SHCBP1L, SMCP, SPATA16, SPATA19, SPINK2, TEX33, TKTL2, TMCO2, TMCO5A, TNP1, TNP2, TSPAN16, TSSK1B, TTLL2, UBQLN3). These genes, particularly the above-mentioned 8 genes, are involved in diverse biological processes such as germ cell development, spermatid development, spermatid differentiation, regulation of proteolysis, spermatogenesis and metabolic processes. Owing to the stage-specific expression of these genes, any mal-expression can ultimately lead to male infertility. Therefore, currently available data on all branches of omics relating to male fertility can be used to identify biomarkers for diagnosing male infertility, which can potentially help in unravelling some idiopathic cases.
Re: The Impact of COVID-19 Vaccine on Sperm Quality
(2022) Omolaoye, Temidayo S; Du Plessis, Stefan
Experts summary: Owing to concerns about the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on male fertility and the potential analogous effects of the coronavirus vaccine, Barda and colleagues [1] evaluated the effects of two doses of the Pfizer SARS-CoV-2 vaccine (BNT162b) on sperm parameters. This prospective cohort study included 898 samples from 33 sperm donors, with each donor serving as his own control. Basic semen parameters (total sperm count, total motile count, percentage motile sperm) were assessed in 425 semen samples before the first vaccination and compared to 473 samples collected at least 72 d after receiving the second dose of the vaccine. Total sperm count and total motile count increased after completion of two doses of the vaccine compared to samples obtained before vaccination, while the percentage of motile sperm remained unchanged. In addition, the authors evaluated whether vaccination would affect the quality of freeze-thawed semen samples. Findings showed that the BNT162b, SARS-CoV-2 vaccine did not negatively affect sperm quality after freezing. According to the scientific literature, the virus triggers adverse effects on male sexual and reproductive health, while the vaccine appears to be safe, as evidenced by Barda et al [1]. Therefore, vaccine uptake is recommended, and patients and medical doctors should be counseled accordingly.
SARS-CoV-2 and the testis: similarity with other viruses and routes of infection
(2020) Du Plessis, Stefan
Abstract: Since the start of the latest coronavirus (SARS-CoV-2) outbreak, the number of infected individuals and cases of coronavirus disease (COVID-19) has been increasing exponentially worldwide. Of interest is existing evidence that orchitis can develop due coronavirus infection. It is therefore not unreasonable to believe that SARS-CoV-2 could be transmitted by semen. Consequently, it is of paramount importance that individuals who could potentially be infected take all possible care to mitigate the likely risk of passing on the infection through sexual intercourse.
Semen and viruses: significance during the transmission of infections
(2022) Du Plessis, Stefan
Introduction: Viral infections may trigger significant public health problems, and semen can be considered a vital transmission route with potential evolutionary advantages. Xie et al. recently published a meta-analysis showing that the susceptibility of semen parameters to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection could lead to marked impairments of male reproductive function. Thus, additional efforts should be made to study the long-term effects of COVID-19 infection and other infections on male reproduction.
Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology
(2022) Du Plessis, Stefan
Abstract: Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.
Statins and Male Fertility: Is There a Cause for Concern?
(2022) Omolaoye, Temidayo S.; Mubarak, Maitha; Cyril, Asha Caroline; Duvuru, Ruthwik; Radhakrishnan, Rajan; Du Plessis, Stefan
Abstract: The well-known 3-hydroxyl 3-methyl glutaryl-Coenzyme A reductase inhibitors, called statins, have been the main medication used in the treatment of hypercholesterolemia and some cases of cardiovascular diseases. The effectiveness of this drug in controlling cholesterol production is impeccable, however, patients often complain of a variety of side effects, such as myalgia, muscle atrophy, and in some cases, rhabdomyolysis. Not only has the use of statins caused the aforementioned side effects, but they are also shown to cause testicular discomfort, erectile dysfunction, altered semen parameters, and modified steroid hormone production. These reported adverse effects on male fertility are not generally agreed upon, as some have shown the use to be beneficial. Hence, this makes the aftermath effect of statin use on male fertility debatable and controversial. The negative effects have been associated with imbalanced or reduced steroid hormones, which are necessary for proper spermatogenesis and other sexual functions. Meanwhile, the beneficial effects are related to statin’s anti-inflammatory and cardioprotective properties. These contradictory findings are in part due to the different age of users, concentrations of statins, the type and duration of treatment, and the underlying disease and/or comorbidities. Therefore, the current study aims to analyze the literature and gather evidence as to the effects of statin on male sexual health and reproductive parameters, and subsequently give recommendations for the direction of future studies.
Strategies for malaria vaccination during the COVID-19 pandemic in African countries
(2022) Nawaz, Faisal A; Du Plessis, Stefan
Abstract: Since October 2021, the World Health Organization (WHO) recommends the use of RTS,S/AS01 (RTS,S) malaria vaccine for children in areas of moderate to high transmission of Plasmodium falciparum in Africa. The vaccine can reduce the 241 million cases of malaria and 627 000 malaria deaths worldwide; it is much needed in the WHO African Region, which accounts for 228 million cases of malaria (95% of global cases) and about 96% of global malaria deaths. However, an effective vaccine roll-out in Africa can only be achieved when region-specific challenges can be overcome; intraregional inequality, health-care systems strengthening and lessons from community engagement in previous public health crises.
Taking a Leap of Faith:A Study of Abruptly Transitioning an Undergraduate Medical Education Program to Distance-Learning Owing to the COVID-19 Pandemic
(2021) Du Plessis, Stefan; Otaki, Farah; Zaher, Shroque; Zary, Nabil; Inuwa, Ibrahim M.; Lakhtakia, Ritu
Abstract: The COVID-19 pandemic has forced universities worldwide to immediately transition to distance-learning. Although numerous studies have investigated the effect of the COVID-19 pandemic on universities in the Middle East, none have reflected on the process through which medical education programs for health professions underwent this transition. This study aimed to elucidate the rapid transition to distance-learning of an undergraduate medical program at the College of Medicine, Mohammad Bin Rashid University of Medicine and Health Sciences (Dubai, United Arab Emirates), owing to the COVID-19 pandemic. An action research approach constituted the foundation of this collaborative effort that involved investigations, reflections, and improvements of practice, through ongoing cycles of planning, acting, observing, and reflecting. Efforts of transitioning to distance-learning were grouped into four interrelated aspects: supporting faculty members in delivering the program content, managing curriculum changes, engaging with the students to facilitate distance-learning experiences, and conducting web-based assessments. Challenges included the high perceived uncertainty, need for making ad hoc decisions, lack of experiential learning and testing of clinical skills, and blurring of work-life boundaries. Our preliminary findings show the successful generation of a strong existing digital base, future prospects for innovation, and a cohesive team that was key to agility, rapid decision-making, and program implementation.
Testicular oxidative stress and apoptosis status in streptozotocin-induced diabetic rats after treatment with rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia), and sutherlandia (Lessertia frutescens) infusions
(2021) Omolaoye, Temidayo S; Du Plessis, Stefan
Objective: To investigate the testicular oxidative stress and apoptosis status, as well as the sperm functional parameters in streptozotocin (STZ) induced diabetic rats following treatment with rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia) and sutherlandia (Lessertia frutescens) infusions. Methods: Diabetes was induced by injecting fourteen-week-old adult male Wistar rats (250-300 g) with a single intraperitoneal injection of STZ (45 mg/kg body weight). Fifty rats were randomly divided into five groups: the vehicle group received 0.1 M citrate buffer, the diabetic control group received 45 mg/kg STZ, the diabetic+rooibos group received 45 mg/kg STZ + 2.0% rooibos, the diabetic+honeybush group received 45 mg/kg STZ + 4.0% honeybush, and the diabetic+sutherlandia group received 45 mg/kg STZ + 0.2% sutherlandia. Rats were sacrificed 7 weeks after induction of diabetes mellitus. The testes and epididymides were harvested and weighed after induction. Spermatozoa were retrieved from the cauda epididymis for motility, concentration, and morphology analysis, and the testis was used for all biochemical assays. Oxidative stress was determined by measuring malondialdehyde levels, catalase, and superoxide dismutase activities, while apoptotic biomarkers were evaluated by Western blotting assays. Results: After induction of diabetes, rats in the diabetic control group, diabetic+rooibos group, diabetic+honeybush group, and diabetic+sutherlandia group presented with significantly elevated blood glucose levels as compared with the vehicle group (P<0.001). Rats in the diabetic control group had a reduction in sperm progressive motility, while rats in the diabetic+rooibos group and the diabetic+sutherlandia group displayed an increase in progressive motility as compared with the diabetic control group. The diabetic control animals showed a 40.0% decrease in sperm concentration when compared to the vehicle group, and there were no significant differences in sperm kinematic and speed parameters between the groups. In addition, the percentage of morphologically normal spermatozoa was increased by 13.0%, 16.0%, and 15.0% after treatment with rooibos, honeybush, and sutherlandia, respectively and the rats in the diabetic+infusion groups also displayed an increase in superoxide dismutase activity when compared to the diabetic control group. Conclusions: Rooibos, honeybush and sutherlandia infusions may partly alleviate diabetes-induced sperm function impairment by reducing oxidative stress.
The Uruguayan semen donor population: A twenty-eight-year retrospective study
(2019) Du Plessis, Stefan
Abstract: Several studies have reported a global decline in seminal quality over the years. The objective of this study was to describe the semen donor population of Uruguay through comparing data of successive samples banked by the same donors and the analysis of their semen and physical characteristics, ancestry origin and educational level. A total of 3,449 ejaculated samples collected from 71 donors, cryobanked between 1989 and March 2017 at Fertilab, were analysed. Results revealed a mean age of 23.90 ± 3.98 years, an average weight of 74.95 ± 1.09 kg and a mean height of 1.78 ± 0.06 m. The majority of the donors trace their origin to Europe (74.65%, 53/71) and 66.19% (47/71) have a level of education higher than secondary school. We observed longitudinal differences in two parameters, that is sperm concentration and semen volume. Sperm concentration declined, while semen volume increased significantly over the 28-year period. The results of the present study are in accordance with that of previous articles that also reported a decline in sperm concentration over time. However, no differences were observed in total sperm number per ejaculate due to the increase in semen volume values, thus reflecting no real changes in sperm production over time.
Using publicly available transcriptomic data to identify mechanistic and diagnostic biomarkers in azoospermia and overall male infertility
(2022) Omolaoye, Temidayo S.; Hachim, Mahmood Yaseen; Du Plessis, Stefan
Abstract Azoospermia, which is the absence of spermatozoa in an ejaculate occurring due to defects in sperm production, or the obstruction of the reproductive tract, afects about 1% of all men and is prevalent in up to 10–15% of infertile males. Conventional semen analysis remains the gold standard for diagnosing and treating male infertility; however, advances in molecular biology and bioinformatics now highlight the insufciency thereof. Hence, the need to widen the scope of investigating the aetiology of male infertility stands pertinent. The current study aimed to identify common diferentially expressed genes (DEGs) that might serve as potential biomarkers for non-obstructive azoospermia (NOA) and overall male infertility. DEGs across diferent datasets of transcriptomic profling of testis from human patients with diferent causes of infertility/ impaired spermatogenesis and/or azoospermia were explored using the gene expression omnibus (GEO) database. Following the search using the GEOquery, 30 datasets were available, with 5 meeting the inclusion criteria. The DEGs for datasets were identifed using limma R packages through the GEO2R tool. The annotated genes of the probes in each dataset were intersected with DEGs from all other datasets. Enriched Ontology Clustering for the identifed genes was performed using Metascape to explore the possible connection or interaction between the genes. Twenty-fve DEGs were shared between most of the datasets, which might indicate their role in the pathogenesis of male infertility. Of the 25 DEGs, eight genes (THEG, SPATA20, ROPN1L, GSTF1, TSSK1B, CABS1, ADAD1, RIMBP3) are either involved in the overall spermatogenic processes or at specifc phases of spermatogenesis. We hypothesize that alteration in the expression of these genes leads to impaired spermatogenesis and, ultimately, male infertility. Thus, these genes can be used as potential biomarkers for the early detection of NOA.