Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

Fertility in Cystinosis

Cystinosis is a rare inheritable lysosomal storage disorder characterized by cystine accumulation throughout the body, chronic kidney disease necessitating renal replacement therapy mostly during adolescence, and multiple extra-renal complications. The majority of male cystinosis patients are infertile due to azoospermia, in contrast to female patients who are fertile. Over recent decades, the fertility status of male patients has evolved from a primary hypogonadism in the era before the systematic treatment with cysteamine to azoospermia in the majority of cysteamine-treated infantile cystinosis patients. In this review, we provide a state-of-the-art overview on the available clinical, histopathological, animal, and in vitro data. We summarize current insights on both cystinosis males and females, and their clinical implications including the potential effect of cysteamine on fertility. In addition, we identify the remaining challenges and areas for future research.

Improvement of Astragalin on Spermatogenesis in Oligoasthenozoospermia Mouse Induced by Cyclophosphamide

More than 40% of infertile men are diagnosed with oligoasthenozoospermia and the incidence is still rising, but the effective treatments are not been found until now. Astragalin, one of the main active ingredients in traditional Chinese medicine, may be effective in the treatment of oligoasthenozoospermia. This study investigated the pharmacological effects of astragalin for treatment of oligoasthenozoospermia in male mice, induced by cyclophosphamide (CTX). Male mice were intraperitoneally injected by CTX (50 mg/kg), and astragalin (30 mg/kg) was given via oral gavage once daily. RNA-seq analysis highlighted astragalin upregulated gene expression of anti-apoptosis (AKT1and BCL2-XL), cell proliferation (ETV1, MAPKAPK2, and RPS6KA5) and synthesis of testosterone (STAR, CYP11A1, and PRKACB), but downregulated gene expression of cell apoptosis (BAD, BCL-2, CASPASE9, and CASPASE3) in mouse testis. Astragalin also significantly reversed the reduction in body weight, reproductive organs index, and sperm parameters (sperm concentration, viability, and motility) induced by CTX, and restored testicular abnormal histopathologic morphology induced by CTX. Furthermore, astragalin dramatically rescued the gene expression related to spermatogenesis (AKT1, BCL-2, CASPASE9, CASPASE3, MAPKAPK2, RPS6KA5, STAR, and PRKACB), and increased the level of testosterone by improving related proteins (STAR, CYP11A1, PRKACB) for oligoasthenozoospermia induced by CTX. In conclusion, astragalin may be a potential beneficial agent for oligoasthenozoospermia by increasing the testosterone levels in testis.

Human and animal fertility studies in cystinosis reveal signs of obstructive azoospermia, an altered blood-testis barrier and a subtherapeutic effect of cysteamine in testis

Cystinosis is an inherited metabolic disorder caused by autosomal recessive mutations in the CTNS gene leading to lysosomal cystine accumulation. The disease primarily affects the kidneys followed by extra-renal organ involvement later in life. Azoospermia is one of the unclarified complications which are not improved by cysteamine, which is the only available disease-modifying treatment. We aimed at unraveling the origin of azoospermia in cysteamine-treated cystinosis by confirming or excluding an obstructive factor, and investigating the effect of cysteamine on fertility in the Ctns^-/- mouse model compared with wild type. Azoospermia was present in the vast majority of infantile type cystinosis patients. While spermatogenesis was intact, an enlarged caput epididymis and reduced levels of seminal markers for obstruction neutral α-glucosidase (NAG) and extracellular matrix protein 1 (ECM1) pointed towards an epididymal obstruction. Histopathological examination in human and mouse testis revealed a disturbed blood-testis barrier characterized by an altered zonula occludens-1 (ZO-1) protein expression. Animal studies ruled out a negative effect of cysteamine on fertility, but showed that cystine accumulation in the testis is irresponsive to regular cysteamine treatment. We conclude that the azoospermia in infantile cystinosis is due to an obstruction related to epididymal dysfunction, irrespective of the severity of an evolving primary hypogonadism. Regular cysteamine treatment does not affect fertility but has subtherapeutic effects on cystine accumulation in testis.

A Study of the Regulatory Mechanism of the CB1/PPARγ2/PLIN1/HSL Pathway for Fat Metabolism in Cattle

Fat metabolism is closely related to the economic characteristics of beef cattle. Therefore, regulating fat deposition and increasing intramuscular fat deposition are among the main goals of breeders. In this study, we aim to explore the regulatory role of CB1 gene on PPARγ2/PLIN1/HSL pathway in fat metabolism, and to further explore the differential expression of regulatory factors of this pathway in Shandong black cattle and Luxi cattle. In this study, CB1 overexpression stimulated lipid synthesis in adipocytes to some extent by increasing the levels of FASN and ACSL1. CB1 inhibitors reduce the lipid content in adipocytes and reduce the expression of GLUT1 and Insig1. In addition, overexpression of CB1 decreased the expression of PPARγ2 and led to an increase in PLIN1 expression and a decrease in HSL expression in adipocytes. We also found that the CB1/PPARγ2/PLIN1/HSL was differentially expressed in the different breeds of cattle and was involved in the regulation of fat metabolism, which affected the fatty acid content in the longissimus dorsi muscle of the two breeds. In short, CB1 participates in lipid metabolism by regulating HSL in the PPARγ2 and PLIN1 pathways, and improves lipid formation in adipocytes. In conclusion, CB1/PPARγ2/PLIN1/HSL pathway may be involved in the regulation of lipid metabolism.

β-carotene Rescues Busulfan Disrupted Spermatogenesis Through Elevation in Testicular Antioxidant Capability

β-carotene, precursor of vitamin A, is an excellent antioxidant with many beneficial properties. It is a lipid-soluble antioxidant and a very effective quencher of reactive oxygen species (ROS) to reduce the oxidative stress. In contrast to vitamin A, β-carotene is not toxic even consumed in higher amount when it is delivered from natural plant products. Recently, we found that β-carotene acts as a potential antioxidant in the oocyte to improve its quality. Even though many studies have been reported that β-carotene has the beneficial contribution to the ovarian development and steroidogenesis, it is unknown the effects of β-carotene on the spermatogenesis. This investigation aimed to explore the hypothesis that β-carotene could improve spermatogenesis and the underlying mechanism. And we found that β-carotene rescued busulfan disrupted spermatogenesis in mouse with the increase in the sperm concentration and motility. β-carotene improved the expression of genes/proteins important for spermatogenesis, such as VASA, DAZL, SYCP3, PGK2. Moreover, β-carotene elevated the testicular antioxidant capability by the elevation of the antioxidant glutathione and antioxidant enzymes SOD, GPX1, catalase levels. In conclusion, β-carotene may be applied for the infertile couples by the improvement of spermatogenesis, since, worldly many couples are infertile due to the idiopathic failed gametogenesis (spermatogenesis).

Chestnut polysaccharides benefit spermatogenesis through improvement in the expression of important genes

Recently there has been a continuing worldwide decrease in the quality of human spermatozoa, especially in spermatozoa motility and concentration. Many factors are involved in this decline, and great efforts have been made to rescue spermatogenesis; however, there has been little progress in the improvement of sperm quality. Chestnuts are used in traditional Chinese medicine; their major active components are chestnut polysaccharides (CPs). CPs have many biological activities but their effects on spermatogenesis are unknown. The current investigation was designed to explore the impact of CPs on spermatogenesis and the underlying mechanisms. We demonstrated that CPs significantly increased sperm motility and concentration (4-fold and 12-fold, respectively), and improved seminiferous tubule development by increasing the number of germ cells after busulfan treatment. CPs dramatically rescued the expression of important genes and proteins (STRA8, DAZL, SYCP1, SYCP3, TNP1 etc.) in spermatogenesis. Furthermore, CPs increased the levels of hormone synthesis proteins such as CYP17A1 and HSD17β1. All the data suggested that CPs improved the testicular microenvironment to rescue spermatogenesis. With CPs being natural products, they may be an attractive alternative for treating infertile patients in the future. At the same time, the deep underlying mechanisms of their action need to be explored.

Low doses of carbendazim and chlorothalonil synergized to impair mouse spermatogenesis through epigenetic pathways

Pesticides have been extensively produced and used to help the agricultural production which leads to the contamination of the environment, soil, groundwater sources, and even foodstuffs. Fungicides carbendazim (CBZ) and chlorothalonil (Chl) are widely applied in agriculture and other aspects. CBZ or Chl have been reported to disrupt spermatogenesis and decrease semen quality. However, it is not understood the effects of pubertal exposure to low doses of CBZ and Chl together, and the underlying mechanisms. Therefore, the aim of current investigation was to explore the negative impacts of pubertal exposure to low doses of CBZ and Chl together on spermatogenesis and the role of epigenetic modifications in the process. We demonstrated that CBZ and Chl together synergize to decrease sperm motility in vitro (CBZ 1.0 + Chl 0.1, CBZ 10.0 + CHl 1.0, CBZ 100.0 + Chl 10 μM in incubation medium for 24 h) and sperm concentration and motility in vivo with ICR mice (CBZ 0.1 + Chl 0.1, CBZ 1.0 + CHl 1.0, CBZ 10.0 + Chl 10 mg/kg body weight; oral gavage for five weeks). CBZ + Chl significantly increase reactive oxygen species (ROS) and apoptosis by the increase in the protein level of caspase 8 in vitro. Moreover, CBZ + Chl synergized to disrupt mouse spermatogenesis with the disturbance in sperm production proteins and sperm proteins (VASA, A-Myb, STK31, AR, Acrosin). CBZ + Chl synergized to decrease the protein level of estrogen receptor alpha and the protein level of DNA methylation marker 5 mC in Leydig cells, and to increase the protein levels of histone methylation marker H3K9 and the methylation enzyme G9a in germ cells. Therefore, greater attention should be paid to the use of CBZ and Chl as pesticides to minimise their adverse impacts on spermatogenesis.

Estrogen Receptor-Related DNA and Histone Methylation May Be Involved in the Transgenerational Disruption in Spermatogenesis by Selective Toxic Chemicals

Air pollution is a global threat to human health especially spermatogenesis. Animal and epidemiological studies suggest that epigenetic factors can transmit the pathologies transgenerationally. Paternal epigenetic effects can greatly impact offspring health. In this study and together with our previous report, we found that H₂S donor Na₂S and/or NH₃ donor NH₄Cl diminished mouse fertility, decreased spermatozoa concentration and motility, and impaired spermatogenesis in three consequent generations (F0, F1, and F2). In the current study, we found that DNA methylation, histone methylation, and estrogen receptor alpha (ERα) were impaired by NH₄Cl and/or Na₂S in F0, F1, and F2 mouse testes. Moreover, NH₄Cl and/or Na₂S might act as environmental endocrine-disrupting chemicals to decrease estrogen and testosterone in mouse blood. It has been reported that ERα signaling is intertwined together with DNA methylation and histone methylation, which plays very important roles in spermatogenesis. These data together indicate that the transgenerational disruption in spermatogenesis by NH₄Cl and/or Na₂S may be through ERα-related DNA methylation and histone methylation pathways. Therefore, we strongly recommend that greater attention should be paid to NH₃ and/or H₂S contamination to minimize their impact on human health especially spermatogenesis.

Low dose chlorothalonil impairs mouse spermatogenesis through the intertwining of Estrogen Receptor Pathways with histone and DNA methylation

Recently, environment contaminants including pesticides, fungicides, mycotoxin and others chemicals have been suggested to be responsible for the decline in the human spermatozoa quality especially motility and the increase in infertility rate. Chlorothalonil is used widely for protection of vegetables and crops because it is a broad spectrum fungicide. It has been reported that chronic occupational exposure to fungicides was associated with poor spermatozoa morphology in young men. The pubertal period is very important for the male reproductive system development due to spermatogonial cell proliferation, the expansion of meiotic and haploid germ cells. Although some investigations have studied the male reproductive toxicity of chlorothalonil, almost no studies focused on spermatogenesis. The aim of our current investigation was to explore the impacts of chlorothalonil on spermatogenesis and the underlying mechanisms. It demonstrates: i) chlorothalonil decreased boar spermatozoa motility in vitro and increased the cell apoptosis; ii) chlorothalonil inhibited mouse spermatogenesis in vivo; iii) chlorothalonil disturbed spermatogenesis through the disruption of estrogen receptor signalling; iv) chlorothalonil disrupted histone methylation and DNA methylation which might be through estrogen signalling pathways. Due to the over use or incorrect use, chlorothalonil might cause serious problems to human health, especially spermatogenesis. Therefore we strongly recommend that greater attention should be paid to this fungicide to minimise its impact on human health especially spermatogenesis.

Characterization of serum metabolites as biomarkers of carbon black nanoparticles-induced subchronic toxicity in rats by hybrid triple quadrupole time-of-flight mass spectrometry with non-targeted metabolomics strategy

Carbon black nanoparticles (CBNPs) are one of atmospheric particles components and have been closely related with a series of lung diseases. It can reach the depths of the respiratory tract or even alveolar more easily than those micro-particles. Although some of its toxicities have been confirmed in animals or human bodies, the subchronic toxicity mechanism of CBNPs has been uncertain so far. Therefore, it is very necessary to establish a novel method and clarify the mechanism of subchronic toxicity caused by concentration adjustments of small molecule metabolites in vivo. In animal experiments, CB exposure, recovery and control group were set up. The concentration of CBNPs in chamber was 30.06 ± 4.42 mg/m³. We developed a UHPLC-Q-TOF-MS/MS-based non-targeted metabolomic analysis strategy to analyze serum samples of rats. Then, differential metabolites in serum were found by multivariate data analysis and 39 potential biomarkers were identified. It was showed that main metabolic pathways associated with CBNPs exposure were hormones metabolism, amino acid metabolism, nucleotide metabolism and lipid metabolism. It is worth noting that long-term exposure to CBNPs had the greatest impact on steroid hormones biosynthesis so that the risk of infertility could increase. The results provided a new mechanistic insight into the metabolic alterations owing to CBNPs induced subchronic toxicity.

Low dose carbendazim disrupts mouse spermatogenesis might Be through estrogen receptor related histone and DNA methylation

Pesticides, fungicides are reportedly involved in a decline in spermatozoa quality, especially motility, and a consequent increase in the rate of infertility. Fungicide carbendazim (CBZ) is widely used in agriculture and other aspects. Although CBZ is known to disrupt spermatogenesis, causing a decrease in spermatozoa concentration and motility, the mechanisms are not fully understood. We aimed to further explore the underlying mechanisms of CBZ disruption of spermatogenesis. Pubertal mice were exposed to low doses (0.1, 1 and 10 mg/kg body weight) of CBZ for 5 weeks, then many factors related to spermatogenesis have been explored. It was found that 0.1-10 mg/kg body weight of CBZ exposure decreased mouse sperm motility and concentration, diminished the important protein factors (VASA, PGK2, B-Amy and CREM) for spermatogenesis, reduced sperm protein acrosin level, disrupted very vital epigenetic factors H3K27, 5 mC and 5 hmC. Furthermore, CBZ exposure damaged estrogen receptor alpha (ERα) pathway by decreased the protein levels of ERα and its targets PI3K and AKT. In summary low doses of CBZ exposure disrupted mouse spermatogenesis through estrogen receptor signaling; and that histone methylation and DNA methylation might play vital roles in CBZ disturbance of spermatogenesis through intertwining with estrogen signaling pathways. CBZ from the contamination in environment or food chain poses a serious threat to the normal development of spermatozoa. Therefore we strongly recommend to minimise the use of CBZ since it causes the severe issues on spermatogenesis.

Gestational exposure to low-dose zearalenone disrupting offspring spermatogenesis might be through epigenetic modifications

Zearalenone (ZEA), a F-2 mycotoxin produced by Fusarium, has been found to be an endocrine disruptor through oestrogen receptor signalling pathway to impair spermatogenesis. The disruption on reproductive systems by ZEA exposure might be transgenerational. In our previous report, we have found that low dose (lower than no-observed effect level, NOEL) of ZEA impaired mouse spermatogenesis and decreased mouse semen quality. The purpose of the current investigation was to explore the impacts of low-dose ZEA on spermatogenesis in the offspring after prenatal exposure and the underlying mechanisms. And it demonstrated that prenatal low-dose ZEA exposure disrupted the meiosis process to inhibit the spermatogenesis in offspring and even to diminish the semen quality by the decrease in spermatozoa motility and concentration. The DNA methylation marker 5hmC was decreased, the histone methylation markers H3K9 and H3K27 were elevated, and oestrogen receptor alpha was reduced in the offspring testis after prenatal low-dose ZEA exposure. The data suggest that the disruption in spermatogenesis by prenatal low-dose ZEA exposure may be through the modifications on epigenetic pathways (DNA methylation and histone methylation) and the interactions with oestrogen receptor signalling pathway. Moreover, in the current study, the male offspring were indirectly exposed to low-dose ZEA through placenta and the spermatogenesis in offspring was disrupted which suggested that the toxicity of ZEA on reproductive systems was very severe. Therefore, we strongly recommend that greater attention should be paid to this mycotoxin to minimize its adverse impact on human spermatogenesis.

Effects of long-term cysteamine treatment in patients with cystinosis

Cystinosis is a rare autosomal-recessive lysosomal storage disease with high morbidity and mortality. It is caused by mutations in the CTNS gene that encodes the cystine transporter, cystinosin, which leads to lysosomal cystine accumulation. Patients with infantile nephropathic cystinosis, the most common and most severe clinical form of cystinosis, commonly present with renal Fanconi syndrome by 6-12 months of age, and without specific treatment, almost all will develop end-stage renal disease (ESRD) by 10-12 years of age. Early corneal cystine crystal deposition is a hallmark of the disease. Cystinosis also presents with gastrointestinal symptoms (e.g., vomiting, decreased appetite, and feeding difficulties) and severe growth retardation and may affect several other organs over time, including the eye, thyroid gland, gonads, pancreas, muscles, bone marrow, liver, nervous system, lungs, and bones. Cystine-depleting therapy with cysteamine orally is the only specific targeted therapy available for managing cystinosis and needs to be combined with cysteamine eye drops for corneal disease involvement. In patients with early treatment initiation and good compliance to therapy, long-term cysteamine treatment delays progression to ESRD, significantly improves growth, decreases the frequency and severity of extrarenal complications, and is associated with extended life expectancy. Therefore, early diagnosis of cystinosis and adequate life-long treatment with cysteamine are essential for preventing end-organ damage and improving the overall prognosis in these patients.

Decrease in male mouse fertility by hydrogen sulfide and/or ammonia can Be inheritable

Numerous epidemiological studies suggest that air pollutants cause a decline in the quality of human spermatozoa and thus a reduction in fertility. However, the exact cause of infertility remains unknown. Air pollution gases, such as NH₃ and H₂S are either free or bound to airborne particular materials (PM) and are abundant and reactive. The aim of this current investigation was to explore the impacts of NH₃ and/or H₂S on male fertility and the underlying mechanisms. Male mouse exposed to H₂S and/or NH₃ and after two generations were used to evaluate the impacts on fertility. The fertility, and spermatozoa quality parameters and proteins involved in spermatogenesis were investigated. Our current investigation demonstrates: i) H₂S and/or NH₃ decrease male fertility by 20-30%, reduce the spermatozoa concentration about 20-40%, decrease 10-20%, increase around 30%; ii) the reduction in male fertility by H₂S and/or NH₃ can be inheritable; iii) H₂S and/or NH₃ can diminish male fertility through the disruption of spermatogenesis without affecting other body parameters such as body weight and organ index. One component of air pollutants, for example NH₃, does not have a severe impact; however, two or more pollutants such as H₂S and NH₃ combined can cause serious health problems, especially with regard to male fertility. We suggest that greater attention should be paid to these air pollutants to improve human health and fertility.

MicroRNA-221 may be involved in lipid metabolism in mammary epithelial cells

Milk lipids, important for infant growth and development, are produced and secreted by mammary gland under the regulation of steroid hormones, growth factors, and microRNAs (miRNAs). miR-221 has been identified in milk and adipocytes and it plays important roles in regulating normal mammary epithelial hierarchy and breast cancer stem cells; however, its roles in lipid metabolism in mammary epithelial cells (MECs), the cells of lipid synthesis and secretion, are as yet unknown. Through overexpression or inhibition of miR-221 expression, we found that it regulated lipid metabolism in MECs and was expressed differentially at various stages during murine mammary gland development. Inhibition of miR-221 expression increased lipid content in MECs through elevation of the lipid synthesis enzyme FASN, while overexpression of miR-221 reduced MEC lipid content. Moreover, the steroid hormones estradiol and progesterone decreased miR-221 expression with a subsequent increase in lipid formation in MECs. The expression of miR-221 was lower during lactation, which suggests that it may be involved in milk production. Therefore, miR-221 might be a useful target for influencing milk lipid production.

MicroRNA-126 participates in lipid metabolism in mammary epithelial cells

Lipids are a major component of milk and are important for infant growth and development. MicroRNA-126 (miR-126) has previously been observed in mammary glands and adipocytes and is known to be involved in lipid metabolism during the process of atherosclerosis. However, it remains unknown whether miR-126 also participates in lipid metabolism in mammary luminal epithelial cells (MECs). In the current investigation, miR-126-3p inhibition stimulated lipid synthesis in MECs in part through increasing levels of the lipid synthesis enzymes FASN, ACSL1, and Insig1. Overexpression of miR-126-3p decreased lipid content in MECs with a reduction in FASN and Insig1. Furthermore, the expression of miR-126-3p was diminished by the steroid hormones estradiol and progesterone with a subsequent elevation of lipid formation in MECs. We also noted that miR-126-3p was expressed differentially at various stages of murine mammary gland development, exhibiting a negative correlation with FASN. Together these findings suggest that miR-126-3 might be involved in lipid metabolism in mammary gland.

LncRNA as ceRNAs may be involved in lactation process

The main function of the mammary gland is to secret milk for newborn growth. Milk production process is regulated by hormones, growth factors, noncoding RNAs and other factors locally. Long non-coding RNAs (lncRNAs), one type of recently discovered non-coding RNA, have been found in mammary gland and some studies suggested lncRNA may play important roles in mammary gland development. Competing endogenous RNAs (ceRNAs) are emerging to compete for miRNA binding and, in turn, regulate each other. In the current study, we sequenced mRNA, miRNA and lncRNA in goat mammary tissue at 2 points in lactation (early and mature). All data were co-expressed together from the same samples. Our data showed that the ceRNAs up-regulated during the mature lactation phase were associated with lipid, protein, carbon and amino acid synthesis and metabolism. This correlates with the function of the mature lactation phase: i.e. the continuous production of large amounts of milk, rich in proteins, lipids, amino acids and other nutrients. Alternately, the ceRNAs up-regulated during early lactation were associated with PI3K-AKT pathways and ECM-receptor interactions; these fulfil the functional role of preparing the mammary gland for full lactation. Therefore, the results suggest that ceRNAs work synergistically during different developmental stages to regulate specific functions associated with lactation control. This study suggests that ceRNAs (lncRNA-mRNA) may be involved in lactation process.

miR-15b negatively correlates with lipid metabolism in mammary epithelial cells

Mammary epithelial cells are regulated by steroid hormones, growth factors, and even microRNAs. miR-15b has been found to regulate lipid metabolism in adipocytes; however, its effects on lipid metabolism in mammary epithelial cells, the cells of lipid synthesis and secretion, are as yet unknown. The main purpose of this investigation was to explore the effect of miR-15b on lipid metabolism in mammary epithelial cells, along with the underlying mechanisms. miR-15b was overexpressed or inhibited by miRNA mimics or inhibitors; subsequently, lipid formation in mammary epithelial cells, and proteins related to lipid metabolism, were investigated. Through overexpression or inhibition of miR-15b expression, the current investigation found that miR-15b downregulates lipid metabolism in mammary epithelial cells and is expressed differentially at various stages of mouse and goat mammary gland development. Inhibition of miR-15b expression increased lipid content in mammary epithelial cells through elevation of the lipid synthesis enzyme fatty acid synthetase (FASN), and overexpression of miR-15b reduced lipid content in mammary epithelial cells with decreasing levels of FASN. Moreover, the steroid hormones estradiol and progesterone decreased miR-15b expression with a subsequent increase in lipid formation in mammary epithelial cells. The expression of miR-15b was lower during lactation and negatively correlated with lipid synthesis proteins, which suggests that it may be involved in lipid synthesis and milk production. miR-15b might be a useful target for altering lipid production and milk yield.