Search Results (43)

Male-factor infertility accounts for approxiamately half of all infertility cases globally, yet therapeutic options remain limited for individuals with no retrievable spermatozoa, such as those with non-obstructive azoospermia (NOA). In recent years, artificial gametogenesis has emerged as a promising avenue for fertility restoration, driven by advances in two complementary strategies: organotypic in vitro spermatogenesis (IVS), which aims to complete spermatogenesis ex vivo using native testicular tissue, and in vitro gametogenesis (IVG), which seeks to generate male gametes de novo from pluripotent or reprogrammed somatic stem cells. To evaluate the current landscape and future potential of these approaches, a narrative, semi-systematic literature search was conducted in PubMed and Scopus for the period January 2010 to February 2025. Additionally, landmark studies published prior to 2010 that contributed foundational knowledge in spermatogenesis and testicular tissue modeling were reviewed to provide historical context. This narrative review synthesizes multidisciplinary evidence from cell biology, tissue engineering, and translational medicine to benchmark IVS and IVG technologies against species-specific developmental milestones, ranging from rodent models to non-human primates and emerging human systems. Key challenges—such as the reconstitution of the blood–testis barrier, stage-specific endocrine signaling, and epigenetic reprogramming—are discussed alongside critical performance metrics of various platforms, including air–liquid interface slice cultures, three-dimensional organoids, microfluidic “testis-on-chip” devices, and stem cell-derived gametogenic protocols. Particular attention is given to clinical applicability in contexts such as NOA, oncofertility preservation in prepubertal patients, genetic syndromes, and reprocutive scenarios involving same-sex or unpartnered individuals. Safety, regulatory, and ethical considerations are critically appraised, and a translational framework is outlined that emphasizes biomimetic scaffold design, multi-omics-guided media optimization, and rigorous genomic and epigenomic quality control. While the generation of functionally mature sperm in vitro remains unachieved, converging progress in animal models and early human systems suggests that clinically revelant IVS and IVG applications are approaching feasibility, offering a paradigm shift in reproductive medicine. Full article

Background/Objectives: The prevalence of childhood obesity has recently increased, particularly during the COVID-19 pandemic, owing to lifestyle changes as a result of public health regulations and guidelines introduced by governments worldwide. The aim of our study was to evaluate the impact of novel e-Health applications in addressing childhood obesity prior to and during the COVID-19 pandemic. Methods: The study was conducted as part of the four-year European project BigO (Horizon2020, No.727688). A total of 86 children and adolescents with overweight and obesity (mean age ± standard error of the mean: 11.82 ± 0.25 years; 49 males, 37 females; 31 prepubertal, 55 pubertal) were studied prospectively for 1 year prior to the pandemic (non-COVID-19 group, n = 50) and during the pandemic (COVID-19 group, n = 36). Based on the body mass index (BMI), subjects were classified as having morbid obesity (n = 40, 46,51%) obesity (n = 21, 24.42%), overweight (n = 22, 25.58%), and normal ΒΜΙ (n = 3, 3.49%) according to the International Obesity Task Force cut-off points. The data collection system utilized the BigO technology platform, which connects to a smartphone and smartwatch to objectively record each patient’s diet, sleep, and physical activity. Participants used the BigO system continuously for 4 weeks and wore the smartwatch for specific periods during the week. Subsequently, they entered a personalized, multidisciplinary lifestyle intervention program for 4 months and used the system again for 4 weeks. Results: The key finding was a significantly higher improvement rate in BMI category among children and adolescents during the COVID-19 pandemic (58.3%) compared to before the pandemic (36%). Both groups showed significant reductions in BMI, BMI z-score, insulin resistance indices (homeostatic model assessment and quantitative insulin sensitivity check index), blood pressure, gamma-glutamyl transferase, and insulin concentrations, alongside increases in high-density lipoprotein cholesterol (p < 0.01). Notably, the COVID-19 group experienced a significantly greater reduction in BMI z-score at 12 months compared to the non-COVID-19 group (p < 0.05). Conclusions: Our results reveal that the COVID-19 group demonstrated better compliance with lifestyle interventions and experienced more significant improvements in cardiometabolic risk factors. This suggests that the innovative e-Health applications were successful in managing childhood obesity despite the challenges caused by the COVID-19 pandemic. Full article

This overview explores the complex relationship between environmental factors, particularly obesity, and the timing of puberty, with a focus on how hormonal and genetic interactions are influenced by external conditions. Puberty (gonadarche) is characterised by the activation of the hypothalamic–pituitary–gonadal (HPG) axis. The onset and progression of puberty vary significantly among individuals, primarily due to genetic factors, with key genes like kisspeptin 1 (KISS1) and makorin ring finger protein 3 (MKRN3) playing a crucial role. Cohesively, this paper emphasises that environmental factors, particularly obesity and exposure to endocrine-disrupting chemicals (EDCs), have become significant influences on the timing of puberty. Childhood obesity has risen significantly in recent decades and the age of pubertal onset has declined over the same period. Obesity greatly disrupts hormone regulation in pre-pubertal children. Leptin accelerates the onset of puberty in girls but not in boys. The underlying mechanism is proposed to be the increase in Kiss1/GnRH signalling. On the contrary, excess leptin in boys suppresses testosterone production by increasing oestrogen conversion. Low adiponectin in obese girls may contribute to earlier puberty due to a reduced inhibition of Kiss1/GnRH signalling. Low adiponectin in boys is linked to delayed puberty due to its role in maintaining insulin sensitivity and testosterone production. Hyperinsulinemia influences pubertal timing through central and peripheral mechanisms. Insulin acting synergistically with leptin promotes the earlier onset of puberty in girls but not in boys. The effects of exposure to certain EDCs—mostly obesogenic chemicals that mimic the action of natural hormones—on the timing of puberty remain unclear; hence, further research on this topic is needed. Addressing and preventing obesity in children could potentially mitigate these alterations in pubertal timing. Full article

Background/Objectives: The quality and composition of dietary proteins are crucial during growth, particularly in children who follow vegetarian diets. Branched-chain amino acids (BCAAs: leucine, isoleucine, and valine) and lysine play essential roles in muscle growth, repair, and metabolism and are involved in the regulation of muscle-derived proteins known as myokines. This study aimed to compare the dietary intake and circulating levels of BCAAs, lysine, and myokines—follistatin-like protein 1 (FSTL-1), myostatin, and myonectin—between vegetarian and omnivorous prepubertal children and to explore the impact of diet on muscle metabolism. Methods: Sixty-four healthy Caucasian children aged 4–9 years (forty-two vegetarians and twenty-two omnivores) were assessed for dietary intake using the Dieta 5^® (extended version Dieta 5.0) software. Circulating BCAAs and lysine were measured using high-performance liquid chromatography, while myokine concentrations were determined using enzyme-linked immunosorbent assays. Results: Vegetarian children showed significantly lower intakes of total protein, animal protein, BCAAs, and lysine than omnivores. Correspondingly, the circulating levels of isoleucine, valine, lysine, and albumin were significantly reduced in vegetarians. Among myokines, serum myostatin and myonectin levels were comparable between the groups, but vegetarians had significantly lower median FSTL-1 levels 7.7 (6.5–9.4) ng/mL than omnivores 9.7 (7.5–13.9) ng/mL (p = 0.012). In the entire group of children, positive correlations were observed between dietary total and animal protein intake and circulating valine and lysine levels. Dietary animal protein intake was also positively associated with the serum levels of all myokines, whereas plant protein intake was negatively correlated with myonectin concentration. Conclusions: In conclusion, vegetarian diets in prepubertal children are associated with reduced dietary protein quality and lower circulating BCAAs, lysine, and FSTL-1 levels, which may impact muscle metabolism. Optimizing vegetarian diets using high-quality plant proteins with proper essential amino acids could mitigate their deficiencies and support muscle development during critical growth periods. Full article

Early life adversity (ELA) is a known risk factor for psychopathology, including stress-related anxiety and depressive disorders. The underlying mechanisms and developmental changes remain poorly understood. A likely underpinning is the impact of ELA on the development of stress response systems, including the hypothalamic–pituitary–adrenal (HPA) axis. Our group studied a translational ELA model of spontaneous infant maltreatment by the mother in rhesus macaques, where we used a cross-fostering design to randomly assign infant macaques to either Control or Maltreating (MALT) foster mothers at birth to examine the impact of adverse caregiving on the development of the HPA axis, while controlling for the confounding effects of heritable and prenatal factors. We previously reported higher levels of plasma and hair cortisol (CORT) across the first 6 postnatal months (equivalent to the first 2 years of life in humans) in the MALT than in the Control infants. Here, we followed the same cohort of infants longitudinally to assess the long-term developmental impact of this adverse experience on HPA axis function during the juvenile (12, 18 months) and late adolescent (~5 years) periods. For this, we collected measurements of diurnal CORT rhythm and glucocorticoid negative feedback using the dexamethasone suppression test (DST). At 12 months, we found higher diurnal CORT secretion in MALT females compared to Control females, and impaired negative feedback in response to the DST in both sexes in the MALT group. However, ELA group differences in the HPA axis function disappeared by 18 months and late adolescence, while sex differences in diurnal CORT rhythm emerged or became stronger. These results suggest that infant maltreatment causes dysregulation of the HPA axis during the first year of life, with HPA axis function normalizing later, during the pre-pubertal juvenile period and adolescence. This suggests that the impact of maltreatment on HPA axis function may be transient, at least if the adverse experience stops. Our findings are consistent with human evidence of recalibration/normalization of HPA axis function during adolescence in children that switch from adverse/deprived environments to supportive adoptive families. This research has broad implications regarding the biological processes that translate ELA to psychopathology during development and the pathways to resiliency. Full article

The antioxidant properties of resveratrol (RES) against oxidative toxicity induced by testicular toxicants are well documented. The current study aimed to investigate the probable beneficial role of RES on male reproduction in adult rats following prepubertal exposure to perfluorooctanoic acid (PFOA). Healthy rats of the Wistar strain (23 days old) were allocated into four groups. Rats in group I did not receive any treatment, while rats in groups II, III, and IV received RES, PFOA, and RES + PFOA, respectively, between days 23 and 56 and were monitored for up to 90 days. Exposure to PFOA resulted in a significant reduction in spermiogram parameters, testicular 3β- and 17β-HSD activity levels, and circulatory levels of testosterone. A significant elevation in LPx, PCs, H₂O₂, and O₂⁻, associated with a concomitant reduction in SOD, CAT, GPx, GR, and GSH, was noticed in the testes, as well as region-specific changes in pro- and antioxidants in the epididymides of exposed rats compared to controls. A significant increase in serum FSH and LH, testicular cholesterol levels, and caspase-3 activity was observed in PFOA-exposed rats compared to controls. Histological analysis revealed that the integrity of the testes was deteriorated in PFOA-exposed rats. Transcriptomic profiling of the testes and epididymides revealed 98 and 611 altered genes, respectively. In the testes, apoptosis and glutathione pathways were disrupted, while in the epididymides, glutathione and bile secretion pathways were altered in PFOA-exposed rats. PFOA exposure resulted in the down-regulation in the testes of 17β-HSD, StAR, nfe2l2, ar, Lhcgr, and mRNA levels, associated with the up-regulation of casp3 mRNA, and down-regulation of alpha 1 adrenoceptor, muscarinic choline receptor 3, and androgen receptor in the epididymides of exposed rats compared to the controls. These events might lead to male infertility in PFOA-exposed rats. In contrast, restoration of selected reproductive variables was observed in RES plus PFOA-exposed rats compared to rats exposed to PFOA alone. Taken together, we postulate that prepubertal exposure to PFOA triggered oxidative damage and altered genes in the testes and epididymides, leading to suppressed male reproductive health in adult rats, while RES, with its steroidogenic, antiapoptotic, and antioxidant effects, restored PFOA-induced fertility potential in rats. Full article

In this study, the expression and localization of gonadotropin-releasing hormone (GnRH1) and kisspeptin (KISS1) and their specific receptors in canine ovarian and uterine tissues were investigated after the application of deslorelin acetate (Suprelorin^®, 4.7 mg, Virbac, France) in the late prepubertal period. We hypothesized that prolonged treatment of prepubertal dogs with deslorelin would alter the expression of GnRH and kisspeptin genes in the uterus and ovaries. Ovarian and uterine samples of 25 dogs with an average age of 7.8 ± 0.2 months and from mixed breeds were used. Following implant insertion, dogs entered estrus (EST; n = 6); dogs without estrus (N-EST; n = 10) comprised the experimental groups. Nine dogs with placebo implants served as a control (CONT). Ovarian and uterine tissues were investigated for expression of GnRH1, GnRHR, KISS1, and KISS1R/GPR54 mRNA and protein by using IHC and RT-qPCR. In the uterus, expression of GnRH1 significantly decreased in response to deslorelin treatment in the N-EST, compared with the control group. Compared with CONT, KISS1R expression in ovarian samples was significantly lower in the EST group. Uterine protein expression of GnRH1 appeared weaker in N-EST than in CONT. While GnRH1-system members and KISS1 protein were localized in the follicles at various stages and stroma, no or only weak signals were detected for KISS1R in the ovarian samples. Deslorelin-mediated induction of puberty by changing the expression of some of the GnRH and KISS1-system members seems to have an effect on ovarian and uterine functionality. Deslorelin implants can, therefore, not be considered a valuable alternative to induce fertile estrus in late-prepubertal bitches. However, further studies with a larger number of animals are needed to clarify the effect of deslorelin-mediated induction of puberty. Full article

Increasing survival rates of children following cancer treatment have resulted in a significant population of adult survivors with the common side effect of infertility. Additionally, the availability of genetic testing has identified Klinefelter syndrome (classic 47,XXY) as the cause of future male infertility for a significant number of prepubertal patients. This study explores new spermatogonia stem cell (SSC)-based fertility therapies to meet the needs of these patients. Testicular cells were isolated from cryopreserved human testes tissue stored from XY and XXY prepubertal patients and propagated in a two-dimensional culture. Cells were then incorporated into a 3D human testicular organoid (HTO) system. During a 3-week culture period, HTOs maintained their structure, viability, and metabolic activity. Cell-specific PCR and flow cytometry markers identified undifferentiated spermatogonia, Sertoli, Leydig, and peritubular cells within the HTOs. Testosterone was produced by the HTOs both with and without hCG stimulation. Upregulation of postmeiotic germ cell markers was detected after 23 days in culture. Fluorescence in situ hybridization (FISH) of chromosomes X, Y, and 18 identified haploid cells in the in vitro differentiated HTOs. Thus, 3D HTOs were successfully generated from isolated immature human testicular cells from both euploid (XY) and Klinefelter (XXY) patients, supporting androgen production and germ cell differentiation in vitro. Full article

In vitro maturation (IVM) is a promising fertility restoration strategy for patients with nonobstructive azoospermia or for prepubertal boys to obtain fertilizing-competent spermatozoa. However, in vitro spermatogenesis is still not achieved with human immature testicular tissue. Knowledge of various human testicular transcriptional profiles from different developmental periods helps us to better understand the testis development. This scoping review aims to describe the testis development and maturation from the fetal period towards adulthood and to find information to optimize IVM. Research papers related to native and in vitro cultured human testicular cells and single-cell RNA-sequencing (scRNA-seq) were identified and critically reviewed. Special focus was given to gene ontology terms to facilitate the interpretation of the biological function of related genes. The different consecutive maturation states of both the germ and somatic cell lineages were described. ScRNA-seq regularly showed major modifications around 11 years of age to eventually reach the adult state. Different spermatogonial stem cell (SSC) substates were described and scRNA-seq analyses are in favor of a paradigm shift, as the A_dark and A_pale spermatogonia populations could not distinctly be identified among the different SSC states. Data on the somatic cell lineage are limited, especially for Sertoli cells due technical issues related to cell size. During cell culture, scRNA-seq data showed that undifferentiated SSCs were favored in the presence of an AKT-signaling pathway inhibitor. The involvement of the oxidative phosphorylation pathway depended on the maturational state of the cells. Commonly identified cell signaling pathways during the testis development and maturation highlight factors that can be essential during specific maturation stages in IVM. Full article

The increase in cancer survival rates has put a focus on ensuring fertility preservation procedures for cancer patients. Ovarian tissue cryopreservation presents the only option for prepubertal girls and patients who require immediate start of treatment and, therefore, cannot undergo controlled ovarian stimulation. We aimed to provide an assessment of stem cells’ impact on cryopreserved ovarian tissue grafts in regard to the expression of growth factors, angiogenesis promotion, tissue oxygenation, ovarian follicle survival and restoration of endocrine function. For this systematic review, we searched the Scopus and PubMed databases and included reports of trials using murine and/or human cryopreserved ovarian tissue for transplantation or in vitro culture in combination with mesenchymal stem cell administration to the grafting site. Of the 1201 articles identified, 10 met the criteria. The application of stem cells to the grafting site has been proven to support vascular promotion and thereby shorten the period of tissue hypoxia, which is reflected in the increased number of remaining viable follicles and faster recovery of ovarian endocrine function. Further research is needed before implementing the use of stem cells in OT cryopreservation and transplantation procedures in clinical practice. Complex ethical dilemmas make this process more difficult. Full article

Background: The impact of the COVID-19 pandemic on the incidence rate of childhood type 1 diabetes (T1D) is controversial. Our aim was to analyze the incidence of new-onset T1D among children aged 0–17 before and during the COVID-19 pandemic in Israel. Methods: Data obtained from the national T1D registry for children aged 0–17 were analyzed for the pre-pandemic (1997–2019) and pandemic (2020–2022) periods. In the pre-pandemic period, 7246 children with newly diagnosed T1D were compared with 1490 children diagnosed during the pandemic period. Results: T1D incidence significantly increased in the 0–17 age group from a mean of 12.9/10⁵ (pre-pandemic) to 17.7/10⁵ and 16.7/10⁵ during the first two years of the pandemic (2020 and 2021, respectively) (p = 0.0001). Stratifying by age group (0–4, 5–9, 10–14, and 15–17) revealed a significant increase in the 5–9, 10–14, and 15–17 groups, both in 2020 (p = 0.0001) and in 2021 (p = 0.0001). The incidence rate in the 0–4 age group showed no change in the first year of the pandemic (2020) (p = 0.4). However, in the second year of the pandemic (2021), there was a significant increase from 6.3/10⁵ in the pre-pandemic period to 9.1/10⁵ (p = 0.001). Anti-COVID-19 vaccination in 2022 led to a significant decrease in the incidence rates in the 10–14 and 15–17 age groups (p = 0.03 and p = 0.02, respectively). Conclusion: The COVID-19 pandemic was associated with a significant increase in the incidence of new-onset T1D in prepubertal and pubertal children. Anti-COVID-19 vaccination decreased the incidence rate significantly only in pubertal children. Full article

Fibroblast growth factor 21 (FGF21) has been identified in multiple mammalian species as a molecular marker of energy metabolism while also providing negative feedback to the gonads. However, the role of FGF21 in regulating the energetic and reproductive physiology of beef heifers and cows has yet to be characterized. Herein, we investigated the temporal concentrations of FGF21 in female beef cattle from the prepubertal period to early lactation. Circulating concentrations of FGF21, non-esterified fatty acids, plasma urea nitrogen, glucose, and progesterone were assessed. Ultrasonography was employed to determine the onset of puberty and resumption of postpartum ovarian cyclicity as well as to measure backfat thickness. Finally, cows and calves underwent the weigh-suckle-weigh technique to estimate rate of milk production. We have revealed that FGF21 has an expansive role in the physiology of female beef cattle, including pubertal onset, adaptation to nutritional transition, rate of body weight gain, circulating markers of metabolism, and rate of milk production. In conclusion, FGF21 plays a role in physiological functions in beef cattle that can be applied to advance the understanding of basic scientific processes governing the nutritional regulation of reproductive function but also provides a novel means for beef cattle producers to select parameters of financial interest. Full article

This study aimed to optimise culture conditions for murine preantral follicles to improve their growth and survival. Preantral follicles (diameter 100–130 µm) were isolated from prepubertal NMRI mice and individually cultured within alginate beads for 12 days. Three conditions were evaluated: (1) follicle re-encapsulation on day 6 of culture-reducing alginate concentration (0.5% to 0.25% w/v), (2) the presence of oestradiol (E₂), and (3) increased follicle-stimulating hormone (FSH) concentration in the culture medium (from 10 to 100 mIU/mL FSH). Follicle morphology and growth, as well as anti-Müllerian hormone (AMH) production, were evaluated. From day 8, re-embedded follicles had a larger average diameter compared to follicles without alginate re-encapsulation (0.5% and 0.25% groups, p < 0.05). Oestradiol (1 µM) had a significantly positive effect on the mean follicular diameter and antrum formation (p < 0.001). Moreover, follicles cultured with 100 mIU/mL FSH showed faster growth (p < 0.05) and significantly higher antrum formation (p < 0.05) compared to the low FSH group. Nevertheless, AMH production was not affected by any of the culture conditions. In conclusion, the growth and survival of mouse preantral follicles during a 12-day period were improved by altering the alginate concentration midways during culture and adding E₂ and FSH to the culture medium. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a prevalence rate of 2.78%, and it is characterized by deficits in sociability and communication and restricted patterns of interests and activities. Remarkably, this psychiatric disorder exhibits a pronounced gender bias, with 80% of children diagnosed with ASD being boys. In this review, we will present advancements in mouse models of ASD and their potential contributions to our understanding of the disorder. We will highlight how initial pre-clinical investigations focused solely on male mice due to the gender bias in ASD and explain why we believe that this approach might have had detrimental consequences regarding our understanding of ASD etiology and pathophysiology. We will highlight the evidence of two sensitive periods during brain development when differential exposure to gonadal hormones may result in sex differences in brain function and behavior: the perinatal period and the pre-pubertal period. Finally, we will suggest neuroinflammation as a feasible biological mechanism that may converge different ASD etiological factors and cellular mechanisms into a brain sexual differentiation context, thus accounting for the gender disparities observed in the disorder. Full article

The objectives were (a) the study of haemodynamic parameters of blood flow within the testicular artery, (b) the assessment of differences in these parameters at different segments of the artery (i.e., sequentially, as the artery flows through different regions of the testis), and (c) the identification of potential associations with measures of testicular maturation. Eight healthy beagle-breed male dogs were monitored at fortnightly intervals from the 4th to the 40th week of life, by using clinical, seminological, and ultrasonographic (B-mode, pulsed-wave Doppler) examinations. Haemodynamic parameters were assessed at four different segments of the testicular artery: at the distal supra-testicular, the marginal testicular at the cranial pole of the testis, the marginal testicular at the caudal pole of the testis, and the intratesticular. The study period was divided into three time slots (pre-puberty, puberty, and post-puberty) depending on testicular maturation and sperm production. No clinically evident abnormalities were seen in any animal throughout the study. Semen ejaculates were first collected on the 28th week, and spermatozoa were first seen on the 30th week of life. The results of B-mode examination indicated that in all dogs, the echogenicity of the testicular parenchyma was homogeneous. The waveforms of the blood flow in the testicular artery were monophasic with systolic peaks, low diastolic flow, and low vascular resistance. Most cases of significant differences between the three age periods were noted for the comparison of the pre-pubertal to pubertal periods (n = 11); among the parameters studied, the blood volume (n = 9) showed most instances of significant differences; finally, most cases of significant differences were noted in the distal supra-testicular artery (n = 12). Correlations were mainly seen for the end diastolic velocity, the peak systolic velocity and the blood volume (each with two semen evaluation parameters). The distal supra-testicular and the marginal artery at the cranial pole of the testis are recommended as the most appropriate segments of the vessel for performing a Doppler examination in the testicular artery due to the adequate size and the clear spectral waveforms as early as the 12th week of age of the animals. Full article