Tubular Diameter Research Articles

Gallic acid mitigates lipopolysaccharide-induced testicular inflammation via regulation of the NF-κB and PK2/PKR1 pathway.

Genital tract infections are common causes of male infertility, and most of diagnosed men are asymptomatic. This study examined the effect of gallic acid (GA) against lipopolysaccharide (LPS)-induced testicular inflammation. Thirty-two Spraque Dawley, 2.5-3 month-old male rats were separated into four groups (n = 8). Control group; saline at 3ml/kg, and in the GA group; GA was dissolved in saline, by gavage at 100mg/kg for 14 days. LPS group; LPS 5mg/kg as a single dose was given intraperitoneal on the 11th day. LPS + GA group; GA was given for 14 days and LPS 5mg/kg on the 11th day. After 72h of LPS injection, all samples were collected. Semen analysis, biochemical assays, histological evaluations, and immunohistochemical or Western blot analyses for nuclear factor-kappa B (NF-κB) and Prokineticin 2/prokineticin receptor 1(PK2/PKR1) pathways were performed. There was a significant decrease in body and testicular weight, sperm parameters, serum testosterone level, mean seminiferous tubule diameter, germinal epithelial thickness, and Johnsen score in the LPS group compared to control and GA groups. However, a significant increase was found in interstitial space width, percentage of abnormal sperm, NF-κB and PK2 immunoreactivities, and expression of PK2 and PKR1 proteins. In the LPS + GA group, GA administration was observed to significantly prevent these adverse effects. In conclusion, the inhibitory effects of GA on the NF-κB and PK2/PKR1 pathways not only suppressed the inflammatory response but also restored impaired sperm parameters and testicular structure. These findings indicate GA's potential for treating testicular inflammation and protecting male reproductive health.

Impact of trypanosomiasis on male camel infertility

IntroductionBlood parasitism is a significant clinical disease that silently undermines the livestock industry, particularly affecting camels. This study aimed to assess the prevalence of Trypanosoma evansi in Arabian camels (Camelus dromedarius) and its impact on infertility by examining serum protein fractions, lipids, reproductive indices, and the expression of heat shock protein (HSP70) during breeding season.MethodsA total of 107 male post-pubertal camels, aged between 5 and 10 years, were collected randomly from slaughtering house in Assiut Governorate, Egypt.ResultsMicroscopic and serological examinations revealed that 23.4% (25/107) of the camels were infected with T. evansi. Infected camels exhibited a highly significant increase in total serum protein. The assessment of dyslipidemia, measure as binary variables for lipid profiles (cholesterol, triglycerides, HDL, and LDL), indicated a nonsignificant increase in risk of dyslipidemia in infected camels compared to healthy camels. Proteomic analysis identified four major protein fractions in the infected camels compared to healthy camels with molecular weights of 181.72, 87.59, 30.5, and 19.5 kDa using SDS electrophoresis. Testicular tissue of the infected camels showed degeneration and necrotic changes in seminiferous tubules and interstitial tissue, along with edema and congestion. There was a significant reduction in the diameter of seminiferous tubules and germinal epithelium height. A marked reduction in testosterone levels and a high expression of HSP70 in spermatogonia, spermatocytes, Sertoli cells, and Leydig cells were observed.DiscussionConsequently, a combination of physiological and hormonal analyses may serve as a reliable indicator of Trypanosoma infection.

Unseen Threats: The Long-term Impact of PET-Microplastics on Development of Male Reproductive Over a Lifetime.

The physical abrasion of plastics from simple everyday entered the food chain, with associated risks recently emphasized. Although many studies have reported the adverse effects of microplastics (MPs) on human, the reproductive implications of continuous exposure to physically abraded polyethylene terephthalate (PET)-MPs remain unexplored. Ingestion of physically abraded PET-MPs (size range: 50-100µm) in mice from 5 to 34 weeks of age at an annual intake relevant dose of MPs (5 mgweek-1) significantly impaired male reproductive function. Reductions in seminiferous tubule diameter and epithelial height are observed (p <0.0001), with 32.2% decrease in Leydig cells and 24.3% reduction in testosterone levels (p <0.05). The epididymis shows marked deterioration in all regions, with total sperm concentration significantly reduce from 17.0 × 10⁶ to 5.3 × 10⁶ (p <0.01) and decrease motility. Transcriptome analysis demonstrates downregulation of genes related with gonadotropin-releasing hormone secretion, testosterone biosynthesis, and Meiosin gene, which is for crucial spermatogenesis. Continuous ingestion of physically abraded PET-MPs from plastic bottles adversely affected testicular and epididymal functions, leading to hormonal imbalances and abnormal sperm production. These findings raise concerns about the impact of commonly used plastics on male reproductive development, highlighting potential risks for future generations.

Antioxidant and Antiapoptotic Effects of Primula vulgaris L. Against Methotrexate-Induced Testicular Damage in Rats

The aim of this study was to investigate the antioxidant and antiapoptotic effects of Primula vulgaris extract against methotrexate (MTX)-induced testicular damage. In this study, 4 groups were formed with 8 rats in each group. Rats in group 1 were given 0.8 mg/kg physiological serum via gavage for 7 days. The rats in group 2 were administered a single dose (30 mg/kg) of MTX intraperitoneally on the first day of the study. The rats in group 3 were administered a single dose (30 mg/kg) of MTX on the first day of the study and then 100 mg/kg of aqueous extract via gavage for 7 days starting from the first day. The rats in group 4 were given 100 mg/kg of aqueous extract via gavage for 7 days. On the 8th day, the testicles and epididymis of the rats were removed under anesthesia and their blood was collected. The removed testicles were used for histological and biochemical analyses. When group 2 was compared with group 1, it was determined that seminiferous tubule diameter, epithelial thickness, sperm count, motility, vitality, and Johnsen scoring values decreased; tubule number that immature cells sloughed into the lumen and apoptotic index (AI) increased. In group 3, it was observed that seminiferous tubule diameter, epithelial thickness, sperm count, motility, vitality, and Johnsen scoring values increased; tubule number that immature cells sloughed into the lumen and AI decreased compared to group 2. When group 2 was compared with group 1, it was found that MDA values increased, and SOD and CAT values decreased in blood plasma and testicular tissue. According to the study results, it was determined that MTX caused damage to the testicle by creating oxidative stress, while Primula vulgaris reduced this damage thanks to its antioxidant effects.

Investigation of the effects of diisobutyl phthalate on rat testicular tissue: a histopathological and morphometric evaluation

Phthalates are a group of chemicals used to make plastics more durable, and they are often called plasticisers. Additionally, these chemicals are found in hundreds of products such as floor coverings, lubricating oils, and personal care products (soaps, shampoos, hair sprays). Consumer products containing phthalates can result in human exposure through direct contact and use, indirectly through leaching into the other products or general environmental contamination. In this study, the effects of Diisobutyl phthalate a commonly used phthalate, were investigated histopathologically and morphometrically to determine whether it is one of the causes of increased infertility in recent years. Two study groups of albino Wistar albino rats (total n: 40) were formed; the control group (untreated control group, solvent-corn oil the control group) and the experimental group. DiBP was administered by oral gavage to the experimental group in 3 different doses (0.25–0.5–1 mL/kg/day) mixed with corn oil every day for 28 days. At the end of the experiment, testicular tissue samples taken from all the experimental and control animals were evaluated histopathologically and morphometrically by light microscopy after routine preparation. Degeneration/atrophic tubules were quite prominent in the sections. Tubules containing degenerated germ cells and tubules devoid of germ cells were observed. It was determined that in most tubules, only tubules covered with Sertoli cells remained due to germ cell death. In addition, multinucleated giant cells were frequently encountered in such tubules. Dilatation and thickening in the basal lamina of the seminiferous tubule were accompanied by decreased PAS-positive reaction. The morphometric results supported the histopathological findings. Significant dose-related morphometrical changes (p&lt;0.0001), including seminiferous tubule diameter, tubular lumen diameter, spermatogenic cell line height and basal lamina thickness were observed between the control and administration groups. According to the control, sham and G1, the number of these multinucleated cells (MGC) increased in G2 and G3 but these increases were statistically insignificant (p &gt; 0.9999). In conclusion, it was observed that irreversible damage occurred in the testicular tissues of DiBP-exposed groups, and it was decided that this could be the cause of infertility. Therefore, we recommend the use of an alternative plasticiser with proven reliability.

Fertility up in flames: Reduced fertility indices as a consequence of a simulated heatwave on small African mammals

AbstractWith the increasing frequency and intensity of heatwaves due to climate change, the survival and reproductive success of mammals could be under significant threat. However, the specific effects of these environmental stressors on mammalian reproductive fitness remain insufficiently explored. This study investigates the impact of a simulated heatwave on male fertility indices in two African rodent species: the mesic four‐striped field mouse (Rhabdomys dilectus) and the Namaqua rock mouse (Micaelamys namaquensis) during the breeding season. We measured key indicators of male fertility, including testes mass, testes volume, seminiferous tubule diameter, the presence of sperm, and plasma testosterone levels. Our findings reveal that both species experienced significant effects on male fertility indices, with the smaller R. dilectus showing a decline in all fertility indices following a simulated heatwave. These results suggest that the projected increase in heatwave events may compromise the reproductive success of small mammals, potentially leading to population declines. Finally, this study highlights the need for focused studies on the effect of heatwaves on long‐term reproductive success in both males and females.

Oral Vaccine Formulation for Immunocastration Using a Live-Attenuated Salmonella ΔSPI2 Strain as an Antigenic Vector.

Immunization against Gonadotropin-Releasing Hormone (GnRH) has been successfully explored and developed for the parenteral inoculation of animals, aimed at controlling fertility, reducing male aggressiveness, and preventing boar taint. Although effective, these vaccines may cause adverse reactions at the injection site, including immunosuppression and inflammation, as well as the involvement of laborious and time-consuming procedures. Oral vaccines represent an advancement in antigen delivery technology in the vaccine industry. In this study, a Salmonella enterica serovar Typhimurium (S. Typhimurium) mutant lacking the pathogenicity island 2 (S. Typhimurium ΔSPI2) was used as a vehicle and mucosal adjuvant to deliver two genetic constructs in an attempt to develop an oral immunological preparation against gonadotropin hormone-releasing hormone (GnRH). S. Typhimurium ΔSPI2 was transformed to carry two plasmids containing a modified GnRH gene repeated in tandem (GnRXG/Q), one under eukaryotic expression control (pDNA::GnRXG/Q) and another under prokaryotic expression control (pJexpress::GnRXG/Q). A group of three male BALB/c mice were orally immunized and vaccination-boosted 30 days later. The oral administration of S. Typhimurium ΔSPI2 transformed with both plasmids was effective in producing antibodies against GnRXG/Q, leading to a decrease in serum testosterone levels and testicular tissue atrophy, evidenced by a reduction in the transverse tubular diameter of the seminiferous tubules and a decrease in the number of layers of the seminiferous epithelium in the testes of the inoculated mice. These results suggest that S. Typhimurium ΔSPI2 can be used as a safe and simple system to produce an oral formulation against GnRH and that Salmonella-mediated oral antigen delivery is a novel, yet effective, alternative to induce an immune response against GnRH in a murine model, warranting further research in other animal species.

Comparison of Profile Counting and Diameter Measurement for Estimating the Length Density of Seminiferous Tubules or Epididymal Duct

Transverse testicular sections are often used for histopathological studies and length of seminiferous tubules in the testis is often estimated by the tubule volume divided by the tubules’ cross-sectional area, with the area being obtained by measuring the (short axial) diameters of the round (or elliptical) tubule profiles. But unbiased stereological length estimation is best based on counting of tubule profiles on isotropic sections. To determine the bias of length estimation with the diameter measurement, (i) transverse sections (methacrylate embedded) were obtained from a testis of each normal mature male Sprague-Dawley rat (10 rats in total) and isotropic sections obtained (with the orientator) from the other testis of the rat, and (ii) the tubule length densities were estimated with both methods of profile counting and diameter measurement. The results demonstrated that the method of diameter measurement on transverse or isotropic sections overestimated the length density by 20%-25% compared with profile counting on isotropic sections, probably mainly because of underestimation of the tubules’ cross-sectional area estimated from the short-axial diameters. Length density of the epididymal duct in the epididymis was also estimated with profile counting in the present study, using transverse and isotropic sections for comparison, and a significant statistical difference was not found between the results obtained with the transverse and isotropic sections.

Shrinkable Hydrogels through Host–Guest Interactions: A Robust Approach to Obtain Tubular Cell‐Laden Scaffolds with Small Diameters

AbstractThe availability of realistic in vitro models is crucial for tissue engineering, disease modeling, and drug screening assays. However, reproducing the complex shapes and intricate structures of naturally occurring tissues or organs in the presence of functional cells remains a challenge. For example, it is still not trivial to obtain cell‐laden tubular structures on a micrometer scale present in the nephrons of the human kidney. Here, a unique hydrogel‐based shrinking approach making use of host–guest interactions to decrease the diameters of the preformed hydrogel tubules seeded with cells is proposed as a tool to overcome the abovementioned challenge. The hydrogels are composed of covalently crosslinked methacrylated hyaluronic acid and methacrylated dextran modified with either cyclodextrin or adamantane groups that can form dynamic bonds. The hydrogels are initially formed in the presence of small‐molecule competitors that block any interpolymer host–guest interactions, and the shrinking process is triggered by the release of these competitor molecules. The high shrinking efficiency with a shrinking factor up to eight times in volume and robust cytocompatibility make the host‐guest‐based shrinking approach an appealing tool to obtain hydrogel tubular in vitro models with the desired dimensions on demand.

The role of the co-chaperone DNAJB11 in polycystic kidney disease: Molecular mechanisms and cellular origin of cyst formation.

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 and PKD2, encoding polycystin-1 (PC1) and polycystin-2 (PC2), which are required for the regulation of the renal tubular diameter. Loss of polycystin function results in cyst formation. Atypical forms of ADPKD are caused by mutations in genes encoding endoplasmic reticulum (ER)-resident proteins through mechanisms that are not well understood. Here, we investigate the function of DNAJB11, an ER co-chaperone associated with atypical ADPKD. We generated mouse models with constitutive and conditional Dnajb11 inactivation and Dnajb11-deficient renal epithelial cells to investigate the mechanism underlying autosomal dominant inheritance, the specific cell types driving cyst formation, and molecular mechanisms underlying DNAJB11-dependent polycystic kidney disease. We show that biallelic loss of Dnajb11 causes cystic kidney disease and fibrosis, mirroring human disease characteristics. In contrast to classical ADPKD, cysts predominantly originate from proximal tubules. Cyst formation begins in utero and the timing of Dnajb11 inactivation strongly influences disease severity. Furthermore, we identify impaired PC1 cleavage as a potential mechanism underlying DNAJB11-dependent cyst formation. Proteomic analysis of Dnajb11- and Pkd1-deficient cells reveals common and distinct pathways and dysregulated proteins, providing a foundation to better understand phenotypic differences between different forms of ADPKD.

Ginkgo biloba extract alleviates deltamethrin-induced testicular injury by upregulating SKP2 and inhibiting Beclin1-independent autophagy

BackgroundMale infertility is a worldwide concern that is associated with a decline in sperm quality. Environmental pollutants such as deltamethrin (DM) have harmful effects on male reproductive organs. By maintaining intracellular redox homeostasis, ginkgo biloba extract (GBE) can alleviate male reproductive dysfunction. However, research on the mechanisms by which GBE alleviates reproductive toxicity induced by DM is limited. PurposeIn this study, we investigated whether GBE can alleviate DM-induced testicular and Sertoli cell reproductive toxicity by modulating SKP2 and Beclin1, thus providing a theoretical basis for the development of novel therapeutic approaches. Study designWe explored the role of GBE in mitigating DM-induced testicular damage, with a specific focus on the intricate involvement of ubiquitination and autophagy. MethodsAn experimental model was constructed using ICR male mice and the TM4 cell line. Tissue, cellular, and sperm morphological changes were observed through methods such as Hematoxylin and Eosin (H&E) staining, Periodate-Schiff (PAS) staining, ultrastructural observation, immunohistochemistry, and immunofluorescence. Enzyme and hormone levels were measured, and gene and protein levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting techniques. ResultsIn vivo experiments showed that DM exposure led to decreased sex hormone levels, increased seminiferous tubule diameter and impaired spermatogenesis. Meanwhile, DM exposure was found to decrease ubiquitination levels, leading to mitochondrial damage and further escalation of mitochondrial autophagy. Furthermore, in the DM-induced cell model, the upregulation of Beclin1 expression was associated with the inhibition of the ubiquitin‒proteasome system (UPS) and SKP2, thereby exacerbating autophagy. However, GBE has demonstrated notable efficacy in alleviating the reproductive toxicity induced by DM. ConclusionOur findings highlighted that SKP2 is a key regulator of Beclin1-independent autophagy and that GBE exerts therapeutic effects by upregulating SKP2 and inhibiting Beclin1 activation, which ameliorates autophagy and reduces DM-induced testicular damage.

Investigating the significance of the transgenerational impact of high and repeated doses of ivermectin: Effects on paternal testis histopathology, pups' development, and sexual behavior

Paternal exposure to environmental challenges is critical for the offspring's future health, and the transmission of acquired traits through generations increases the risk of offspring developing diseases. Ivermectin (IVM) is widely used in veterinary and human medicine to treat parasitosis. Our previous studies showed that IVM acute administration induced disorganization of the germinal epithelium and could cause damage to sperm production. Thus, this study investigated the effects of paternal exposure to repeated high ivermectin doses on paternal testis histology. After mating, their pups' development and sexual behavior in adult rats were examined. Method: Two groups of male rats were treated with IVM or its vehicle once a week for three weeks. We observed these males' body weight, organs and testis histology, and testosterone levels. These rats were mated with females without any treatment: the reproductive performance, the offspring development, and the male and female sexual behavior observed in adulthood. Relative to controls, the IVM paternal testis histology showed hypertrophy and hyperplasia of Leydig cells and increased diameter of the seminiferous tubules—no impairment in reproductive performance. In males and females, the physical and reflexes were modified. In adult age, female rats of the IVM group showed reduced sexual behavior and sexual preferences for the same sex, while male sexual behavior was not altered. Thus, it is possible that paternal exposure to IVM interfered with pups' hormonal and growth factors during development and in adult age. Further studies are needed to explore IVM transgenerational effects identifying possible mechanisms underpinning behavioral effects.

Mammalian Ste-20-like Kinase 1/2 (MST1/2) Inhibitor XMU-MP-1: A Potential Compound to Improve Spermatogenesis in Mouse Model of Diabetes Mellitus.

Background/Objectives: Spermatogenesis is a key process in male reproduction that, if it does not happen correctly, can lead to infertility, with diabetes being one of the most prevalent causes of spermatogenesis disruption. Currently, there is a lack of research examining the potential benefits of targeting cell proliferation to enhance spermatogenesis in this condition. XMU-MP1 has been identified as an inhibitor of MST1, a core component of the Hippo pathway, which is anticipated to promote proliferation and regeneration. This study aims to evaluate the effects of XMU-MP1 treatment on sperm and testicular characteristics in mice. Methods: We used the STZ-induced diabetic mouse model to investigate the impact of administering XMU-MP1 on testicular tissue and sperm parameters. This study compared the seminiferous tubules, specifically focusing on the diameter of the seminiferous tubule, the thickness of the seminiferous tubule epithelium, the ratio of the thickness of the seminiferous tubule epithelium to the diameter of the seminiferous tubules, and the lumen diameter of the seminiferous tubules. We also conducted a comparison of sperm parameters, including sperm concentration, progressive motility, total motility, total motility, and morphology. Results: XMU-MP1-treated mice had a larger spermatogenesis area and better sperm motility than control mice. Diabetic mice treated with XMU-MP1 also showed a trend toward improvements in the spermatogenesis area, sperm concentration, sperm motility, and sperm morphology, although these improvements were not statistically significant. Conclusions: XMU-MP1 serves as a potential compound to improve spermatogenesis in mice.

The impact of N-acetylcysteine on hypoxia-induced testicular apoptosis in male rats: TUNEL and IHC findings

The present study aimed to evaluate the impact of N-acetylcysteine (NAC) on testicular hypoxia caused by varicocele, focusing specifically on the regulation of genes related to apoptosis and oxidative stress in the testes of mature Wistar rats.Thirty-two rats were divided into four groups: Control (Sham), hypoxia, testicular hypoxia treated with NAC (Hypoxia + NAC), and healthy animals treated with NAC. After the 8-week treatment period, testicular histopathology and the levels of oxidative stress markers—superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA)—in serum were examined. The expression of Bax and Bcl-2 mRNA was analyzed using immunocytochemistry and RT-qPCR assays, while the apoptosis rate was determined using the TUNEL method.Histopathological evaluations showed that parameters such as Johnsen's score, epithelium width, and seminiferous tubule diameter indicated significant improvement in the Hypoxia + NAC group compared to the Hypoxia group. NAC administration resulted in elevated serum levels of GPx and SOD, accompanied by a reduction in MDA levels (p < 0.003). Furthermore, the study revealed that NAC decreased Bax expression and enhanced Bcl-2 gene and protein expression compared to the varicocele group (p < 0.05). Additionally, NAC administration significantly decreased the rate of apoptosis in germ cells (p < 0.05).These findings suggest that NAC administration can mitigate testicular damage induced by hypoxia from varicocele in rats, primarily due to its antioxidant properties.

Pathological and Hormonal Alterations of the Testis in Balb/C Mice Treated With Spirotetramat Insecticide

Background and Objectives: The side effects of insecticides are undeniable due to their excessive use by farmers. This study aims to investigate the impact of spirotetramat insecticide on pathological and hormonal alteration in BALB/c mice testes. Methods: In this experimental study, 24 adult BALB/c male mice, with a body weight range of 25-30 g, were obtained from the Animal House of Uremia University and examined. Mice were randomly divided into three groups of eight: control, experimental group 1, and experimental group 2. The mice of experimental group 1 received 2.5 mg/kg, and experimental group 2 received 10 mg/kg of spirotetramat. The control group received the same amount of distilled water for 21 days through the mouth by gavage. After this period, the mice were anesthetized and evaluated. Data were analyzed using a 1-way analysis of variance in SPSS version 19 software. Results: The results of the study showed that spirotetramat increased the thickness of the tunica albuginea, the diameter of the seminiferous tubules, the differentiation index of the testis tube, and the spermiogenesis index, but it decreased the thickness of the epithelium of the spermatogenic tubules, the replacement index of active spermatogonia, Leydig cells, and FSH, LH, and testosterone hormone levels. The thickness of interstitial tissue, Sertoli, and lymphocyte cells did not change significantly. Conclusion: By inhibiting the activity of acetyl coenzyme A, spirotetramat insecticide disrupts energy production and prevents the synthesis of lipids in the cells, finally decreasing spermatogenesis in mice.

Radio-protective effects of melatonin therapy against testicular oxidative stress: a systematic review and meta-analysis of rodent models.

Radiation exposure is a concern in today's world, given the widespread use of electronic devices and medical procedures involving ionizing and non-ionizing radiation. Radiations may cause male infertility by inducing oxidative stress in testicular tissue. Melatonin has antioxidant properties. The authors systematically reviewed the literature for the studies that have investigated the effects of melatonin therapy on radiation-induced oxidative stress in rodents' testicular tissue. PubMed, Scopus, and Web of Science were searched for relevant animal trials. Standardized mean difference and 95% CIs were used to pool the data. Subgroup and sensitivity analyses were done. The risk of bias was assessed using SYRCLE tool. Outcomes: histopathology and sperm analyses (testicular apoptotic cells, Johnsen's testicular biopsy score, seminiferous epithelial height, tubular diameter, sperm motility, viability, count, and morphology, concentration of spermatid, spermatocyte, and spermatogonia), body and testes weights (absolute and relative body and testicular weights), reproductive hormones (serum prolactin, FSH, and testosterone), and oxidative stress tissue markers (TBARS, CAT, GSH, GSH-Px, MDA, SOD, and XO, and total antioxidant capacity). Rats and mice were exposed to electromagnetic radiations (gamma, roentgen, microwave, radiofrequency, and high-power line energy) and particle waves (radioiodine and carbon-ion). Melatonin therapy was significantly associated with improved male reproduction. Radiation exposure harms male fertility, but melatonin, as an antioxidant, is potentially associated with improved male reproductive function in rodents. Inconsistencies in research require further investigations.

Perinatal exposure to environmental chemicals that disrupt thyroid function can perturb testis development

Thyroid hormones (THs) are essential for normal growth and development. Their role in skeletal and brain development is well established, with congenital hypothyroidism causing stunted growth and severe intellectual disability. THs are also important for the development of other tissues and organs, including the testis. Developmental hypothyroidism can manifest as smaller testes in early postnatal life that later develop into macroorchidism in adulthood due to increased proliferation of Sertoli cells. Effects of hypothyroidism on the testes can be modelled in rodents by exposing developing animals to TH-suppressing pharmaceuticals such as propylthiouracil (PTU) and methimazole (MMI). These drugs act by inhibiting the thyroperoxidase (TPO) enzyme in the thyroid gland, inhibiting the synthesis of THs. It is possible that environmental chemicals that inhibit TPO activity can also cause TH-mediated effects on the developing testis, but the extent to which this occurs is not known. Herein, we characterized the effects of perinatal exposure to the herbicide amitrole together with the antithyroid drug MMI. Pregnant Sprague-Dawley rats were exposed by oral gavage to two doses of amitrole (25 or 50 mg/kg body weight/day) or MMI (8 or 16 mg/kg body weight/day) from gestational day 7 until birth. After birth, pup exposure was continued by dosing lactating dams from day of delivery until pup day 16. Both chemicals caused a significant reduction in TH levels on day 16. This perinatal hypothyroidism disrupted both germ and Sertoli cell development, resulting in smaller testes and reduced seminiferous tubule diameter in 16-day old pups. Notably, fetal male blood progesterone levels were increased after exposure to both amitrole and MMI, whereas the amitrole-exposed animals also displayed increased estradiol levels. Our study raises concerns that exposure to environmental chemicals that happen to disrupt TH production may disrupt TH-dependent testis development, with adverse consequences to human reproductive health.

Integration analysis of transcriptome and metabolome revealed the potential mechanism of spermatogenesis in Tibetan sheep (Ovis aries) at extreme high altitude

Testis has an indispensable function in male reproduction of domestic animals. Numerous genes and metabolites were related to testicular development and spermatogenesis. However, little is known about the biological regulation pathways associated with fecundity in male Tibetan sheep. In this study, Testes were collected from Huoba Tibetan sheep (HB, 4614 m) and Gangba Tibetan sheep (GB, 4401 m) at extreme high altitude, and Alpine Merino sheep (AM, 2500 m, control group) at medium-high altitude, investigating the genes and metabolites levels of them. The histological analysis of testicular tissue using hematoxylin-eosin (HE) staining was performed for Tibetan sheep and Alpine Merino sheep, and the testes of them were analyzed by transcriptomics and metabolomics to explore the potential mechanism of testicular development and spermatogenesis. The statistical results showed that the cross-sectional area of testicular seminiferous tubules, diameter of seminiferous tubules, and spermatogenic epithelium thickness were significantly smaller in HB and GB than in AM (P < 0.05). Overall, 5648 differentially expressed genes (DEGs) and 336 differential metabolites (DMs) were identified in three sheep breeds, which were significantly enriched in spermatogenesis and other related pathways. According to integrated metabolomic and transcriptomic analysis, glycolysis/gluconeogenesis, AMPK signaling pathway, and TCA cycle, were predicted to have dramatic effects on the spermatogenesis of Tibetan sheep. Several genes (including Wnt2, Rab3a, Sox9, Hspa8, and Slc38a2) and metabolites (including L-histidinol, Glucose, Fumaric acid, Malic acid, and Galactose) were significantly enriched in pathways related to testicular development and spermatogenesis, and might affect the reproduction of Tibetan sheep by regulating the acrosome reaction, meiotic gene expression, and the production of sex hormones. Our results provide further understanding of the key genes and metabolites involved in testicular development and spermatogenesis in Tibetan sheep.

Going with the flow: New insights regarding flow induced K+ secretion in the distal nephron.

K+ secretion in the distal nephron has a critical role in K+ homeostasis and is the primary route by which K+ is lost from the body. Renal K+ secretion is enhanced by increases in dietary K+ intake and by increases in tubular flow rate in the distal nephron. This review addresses new and important insights regarding the mechanisms underlying flow-induced K+ secretion (FIKS). While basal K+ secretion in the distal nephron is mediated by renal outer medullary K+ (ROMK) channels in principal cells (PCs), FIKS is mediated by large conductance, Ca2+/stretch activated K+ (BK) channels in intercalated cells (ICs), a distinct cell type. BK channel activation requires an increase in intracellular Ca2+ concentration ([Ca2+]i), and both PCs and ICs exhibit increases in [Ca2+]i in response to increases in tubular fluid flow rate, associated with an increase in tubular diameter. PIEZO1, a mechanosensitive, nonselective cation channel, is expressed in the basolateral membranes of PCs and ICs, where it functions as a mechanosensor. The loss of flow-induced [Ca2+]i transients in ICs and BK channel-mediated FIKS in microperfused collecting ducts isolated from mice with IC-specific deletion of Piezo1 in the CCD underscores the importance of PIEZO1 in the renal regulation of K+ transport.

Nicotinamide mononucleotide ameliorates ionizing radiation-induced spermatogenic dysfunction in mice by modulating the glycolytic pathway.

Radiotherapy, a common cancer treatment, leads to infertility in male cancer survivors, particularly young and middle-aged patients. Nicotinamide mononucleotide (NMN), a precursor of nicotinamide adenine dinucleotide (NAD +), plays crucial roles in energy metabolism, DNA repair, and gene expression. The purpose of this study is to investigate the protective effects and underlying mechanisms of NMN against ionizing radiation (IR)-induced testicular injury and spermatogenic dysfunction in an adult male mouse model. To assess the effects of NMN, single whole-body γ-ray irradiation is used to induce testicular injury and spermatogenic dysfunction in adult male mice. NMN is orally administered at 500 mg/kg before and after IR exposure. The structural and cellular damage to the testes caused by 5 Gy γ-ray irradiation, as well as the protective effect of NMN on testicular spermatogenic dysfunction, are evaluated. The serum hormone testosterone, LH, and FSH levels, as well as testicular NAD +, lactate, and pyruvate levels, are detected. Furthermore, the expressions of the apoptosis-related genes Bcl-2, Bax, and Caspase-3 and the rate-limiting enzymes HK2, PKM2, and LDHA, which are potentially associated with the mechanism of injury, are examined. The results demonstrate that 5 Gy γ-ray irradiation exposure causes a decrease in the serum testosterone, LH, and FSH levels in adult male mice, as well as in the testicular NAD +, lactate, and pyruvate levels, and causes damage to the testicular structure and cells. Morphometric analysis reveal a decrease in the testis mass, seminiferous tubule diameter, and height of the germinal epithelium. The sperm quantity, motility, and testicular volume are reduced in the 5 Gy group but are restored by NMN supplementation. NMN intervention downregulates the expressions of proapoptotic genes ( Bax and Caspase-3) and upregulates the expression of an antiapoptotic gene ( Bcl- 2). Sertoli cells marker genes ( WT-1, GATA-4, SOX9, and vimentin) and glycolysis rate-limiting enzyme-encoding genes ( HK2, PKM2, LDHA) are significantly upregulated. In summary, NMN has a positive regulatory effect on testicular spermatogenic dysfunction in male mice induced by ionizing radiation. This positive effect is likely achieved by promoting the proliferation of spermatogenic cells and activating glycolytic pathways. These findings suggest that NMN supplementation may be a potential protective strategy to prevent reproductive damage to male subjects from ionizing radiation.