Steroid hormone synthesis in mitochondria

The detoxification ability of sex-role reversed seahorses determines the sexual dimorphism in immune responses to benzo[a]pyrene exposure

Sexual dimorphism in immune responses is an essential factor in environmental adaptation. However, the mechanisms involved remain obscure owing to the scarcity of data from sex-role-reversed species in stressed conditions. Benzo[a]pyrene (BaP) is one of the most pervasive and carcinogenic organic pollutants in coastal environments. In this study, we evaluated the potential effects on renal immunotoxicity of the sex-role-reversed lined seahorse (Hippocampus erectus) toward environmental concentrations BaP exposure. Our results discovered the presence of different energy-immunity trade-off strategies adopted by female and male seahorses during BaP exposure. BaP induced more severe renal damage in female seahorses in a concentration-dependent manner. BaP biotransformation and detoxification in seahorses resemble those in mammals. Benzo[a]pyrene-7,8-dihydrodiol-9,10-oxide (BPDE) and 9-hydroxybenzo[a]pyrene (9-OH-BaP) formed DNA adducts and disrupted Ca2+ homeostasis may together attribute the renal immunotoxicity. Sexual dimorphisms in detoxification of both BPDE and 9-OH-BaP, and in regulation of Ca2+, autophagy and inflammation, mainly determined the extent of renal damage. Moreover, the mechanism of sex hormones regulated sexual dimorphism in immune responses needs to be further elucidated. Collectively, these findings contribute to the understanding of sexual dimorphism in the immunotoxicity induced by BaP exposure in seahorses, which may attribute to the dramatic decline in the biodiversity of the genus.

NR5A1 and NR5A2 regulate follicle development in chicken (Gallus gallus) by altering proliferation, apoptosis, and steroid hormone synthesis of granulosa cells

Chicken ovarian follicle development is regulated by complex and dynamic gene expression. Nuclear receptor 5A1 and 5A2 (NR5A1 and NR5A2, respectively) are key genes that regulate steroid hormone production and gonadal development in mammals; however, studies on follicular development in the chicken ovary are scarce. In this study, we investigated the functions of NR5A1 and NR5A2 on follicle development in chickens. The results showed that the expression of NR5A1 and NR5A2 was significantly higher in small yellow follicles and F5. Furthermore, the expression of NR5A1 and NR5A2 was significantly higher in follicular tissues of peak-laying hens (30 wk) than in follicular tissues of late-laying hens (60 wk), with high expression abundance in granulosa cells (GC). The overexpression of NR5A1 and NR5A2 significantly promoted proliferation and inhibited apoptosis of cultured GC; upregulated STAR, CYP11A1, and CYP19A1 expression and estradiol (E2) and progesterone (P4) synthesis in GC from preovulatory follicles (po-GC); and increased STAR, CYP11A1, and CYP19A1 promoter activities. In addition, follicle-stimulating hormone treatment significantly upregulated NR5A1 and NR5A2 expression in po-GC and significantly promoted FSHR, CYP11A1, and HSD3B1 expression in GC from pre-hierarchical follicles and po-GC. The core promoter region of NR5A1 was identified at the -1,095- to -483-bp and -2,054- to -1,536-bp regions from the translation start site (+1), and the core promoter region of NR5A2 was at -998 to -489 bp. Two single nucleotide polymorphisms (SNP) were identified in the core promoter region of the NR5A1 gene, which differed between high- and low-yielding chicken groups. Our study suggested that NR5A1 and NR5A2 promoted chicken follicle development by promoting GC proliferation and E2 and P4 hormone synthesis and inhibiting apoptosis. Moreover, we identified the promoter core region or functional site that regulates NR5A1 and NR5A2 expression.

Neurosteroids: A potential target for neuropsychiatric disorders

Neurosteroids are steroids produced by endocrine glands and subsequently entering the brain, and also include steroids synthesis in the brain. It has been widely known that neurosteroids influence many neurological functions, including neuronal signaling, synaptic adaptations, and neuroprotective effects. In addition, abnormality in the synthesis and function of neurosteroids has been closely linked to neuropsychiatric disorders, such as Alzheimer's disease (AD), schizophrenia (SZ), and epilepsy. Given their important role in brain pathophysiology and disorders, neurosteroids offer potential therapeutic targets for a variety of neuropsychiatric diseases, and that therapeutic strategies targeting neurosteroids probably exert beneficial effects. We therefore summarized the role of neurosteroids in brain physiology and neuropsychiatric disorders, and introduced the recent findings of synthetic neurosteroid analogues for potential treatment of neuropsychiatric disorders, thereby providing insights for further research in the future.

Peripheral Blood Cells From Older Adults Exhibit Sex-Associated Differences in Mitochondrial Function

Blood-based mitochondrial bioenergetic profiling is a feasible, economical, and minimally invasive approach that can be used to examine mitochondrial function and energy metabolism in human subjects. In this study, we use 2 complementary respirometric techniques to evaluate mitochondrial bioenergetics in both intact and permeabilized peripheral blood mononuclear cells (PBMCs) and platelets to examine sex dimorphism in mitochondrial function among older adults. Employing equal numbers of PBMCs and platelets to assess mitochondrial bioenergetics, we observe significantly higher respiration rates in female compared to male participants. Mitochondrial bioenergetic differences remain significant after controlling for independent parameters including demographic parameters (age, years of education), and cognitive parameters (mPACC5, COGDX). Our study illustrates that circulating blood cells, immune cells in particular, have distinctly different mitochondrial bioenergetic profiles between females and males. These differences should be taken into account as blood-based bioenergetic profiling is now commonly used to understand the role of mitochondrial bioenergetics in human health and aging.

Identification of a mechanism promoting mitochondrial sterol accumulation during myocardial ischemia-reperfusion: role of TSPO and STAR

Hypercholesterolemia is a major risk factor for coronary artery diseases and cardiac ischemic events. Cholesterol per se could also have negative effects on the myocardium, independently from hypercholesterolemia. Previously, we reported that myocardial ischemia-reperfusion induces a deleterious build-up of mitochondrial cholesterol and oxysterols, which is potentiated by hypercholesterolemia and prevented by translocator protein (TSPO) ligands. Here, we studied the mechanism by which sterols accumulate in cardiac mitochondria and promote mitochondrial dysfunction. We performed myocardial ischemia-reperfusion in rats to evaluate mitochondrial function, TSPO, and steroidogenic acute regulatory protein (STAR) levels and the related mitochondrial concentrations of sterols. Rats were treated with the cholesterol synthesis inhibitor pravastatin or the TSPO ligand 4'-chlorodiazepam. We used Tspo deleted rats, which were phenotypically characterized. Inhibition of cholesterol synthesis reduced mitochondrial sterol accumulation and protected mitochondria during myocardial ischemia-reperfusion. We found that cardiac mitochondrial sterol accumulation is the consequence of enhanced influx of cholesterol and not of the inhibition of its mitochondrial metabolism during ischemia-reperfusion. Mitochondrial cholesterol accumulation at reperfusion was related to an increase in mitochondrial STAR but not to changes in TSPO levels. 4'-Chlorodiazepam inhibited this mechanism and prevented mitochondrial sterol accumulation and mitochondrial ischemia-reperfusion injury, underlying the close cooperation between STAR and TSPO. Conversely, Tspo deletion, which did not alter cardiac phenotype, abolished the effects of 4'-chlorodiazepam. This study reveals a novel mitochondrial interaction between TSPO and STAR to promote cholesterol and deleterious sterol mitochondrial accumulation during myocardial ischemia-reperfusion. This interaction regulates mitochondrial homeostasis and plays a key role during mitochondrial injury.

A low dose of benzo(a)pyrene during prepuberty in male rats generated immediate oxidative stress in the testes and compromised steroidogenic enzymes/proteins

The prepubertal period is crucial for sexual development and any alterations can interfere with the reproductive system in adulthood. The aim of this study was to evaluate how Benzo(a)pyrene (BaP) can affect the testes during the prepubertal period. Juvenile male Wistar rats were divided into a control (corn oil + DMSO) and a BaP-group (0.1 μg/kg/day), exposed to BaP for 31 days (gavage), and all parameters were evaluated on postnatal day (PND) 54. Leukocyte counts were decreased. Histological analyses of the testes revealed that height and seminiferous tubules diameters (STDs) were reduced, tubular dynamics were altered, and Leydig cell atrophy was evident in the BaP-group. The testosterone concentration was decreased while FSH levels increased within the BaP-exposed group. Steroidogenic enzymes in the testes were decreased, but steroidogenic acute regulatory protein was not altered. The expression of gstp1 and ckit enzymes was decreased. Reduced glutathione (GSH) and superoxide dismutase (SOD) were increased, whereas malondialdehyde (MDA) was decreased in the testes. In conclusion, BaP or its metabolites causes low systemic toxicity; however, it adversely influences testicular function by disrupting the hormonal axis, unbalancing testicular antioxidative, and blocking the action of the steroidogenic mechanisms.

Visualizing Lipophagy as a New Mechanism of the Synthesis of Sex Steroids in Human Ovary and Testis Using Immunofluorescence Staining Method

Immunofluorescence, a transformative tool in cellular biology, is employed to dissect the intricate mechanisms of cholesterol trafficking in human reproductive tissues. Autophagy, a key player in cellular homeostasis, particularly lipophagy, emerges as a free cholesterol source for steroidogenesis. In this chapter, we describe a comprehensive immunofluorescence staining protocol, with details provided for the precise visualization of subcellular dynamics of mitochondria, lysosomes, and lipid droplets in ex vivo testicular tissue and primary luteal granulosa cell culture models, pivotal components in sex steroid biosynthesis. Here, we detail the culture, treatment, and immunofluorescence protocols, providing a comprehensive guide for researchers. The provided immunofluorescence toolkit serves as a valuable resource for researchers, paving way for advancements in human reproductive health to investigate the intricate interplay between autophagy, lipophagy, and cholesterol trafficking.

Real-Time Visualization of Cholesterol Trafficking in Human Granulosa Cells Using Confocal Live Cell Microscopy as a Tool to Study the Novel Role of Autophagy in Sex Steroid Synthesis

Autophagy is an evolutionarily conserved process that aims to maintain the energy homeostasis of the cell by recycling long-lived proteins and organelles. We have very recently demonstrated that lipophagy, a special form of autophagy, mediates the association of the lipid droplets (LDs) with lysosomes to deliver the lipid cargo within the LDs to lysosomes for degradation in order to release free cholesterol required for steroid synthesis in human ovary and testis. In this chapter, we describe live cell confocal microscopy technique that allows us to monitor real-time cholesterol trafficking and the association of cholesterol-laden LDs with lysosome (lipophagy) in human granulosa cells.

Follow up of a rare case of adrenal insufficiency due to NNT mutation

Hypoglycaemia is one of the most common causes of convulsions in neonatal period. Repeated hypoglycaemic convulsions have to be addressed with utmost urgency to prevent its morbid sequelae. Repeated ketotic hypoglycaemia in the infantile period needs detailed endocrine evaluation. Our patient is a boy in the third year of his life, had presented in infancy with hypoglycaemic convulsions and hyperpigmentation of skin and mucous membrane. Investigations revealed ketotic hypoglycaemia, hypocortisolaemia with high adrenocorticotropic hormone (ACTH) and normal aldosterone, 17-hydroxyprogesterone (17-OHP) and testosterone levels. This suggested isolated glucocorticoid deficiency without mineralocorticoid deficiency. He responded well to hydrocortisone therapy with resolution of symptoms and normalisation of lab parameters. Genetic study confirmed the diagnosis of familial glucocorticoid deficiency (FGD) with homozygous mutation in NNT (nicotinamide nucleotide transhydrogenase) gene with a novel p.Thr578lle variant. This is the first case of FGD with NNT mutation to be reported from the Indian subcontinent.

Subtle perturbations of ovarian steroidogenesis in patients classified as Poseidon Group 3. Which consequences for therapeutic strategy?

The optimal strategy for stimulation of young women with a low ovarian reserve is still a challenging issue because the physio-pathogeny of this disorder is often unknown. As androgen production by the ovary plays a crucial role in folliculogenesis, it was tempting to speculate that subtle perturbations in ovarian steroidogenesis might participate to the low responsiveness to gonadotrophins. Indeed, in vitro analysis of human luteinized granulosa cells has recently provided evidence for some enzymatic deficits in steroidogenesis and altered response to gonadotrophins. Therefore, improving androgen environment of women classified in Poseidon Group 3 should be considered. In this clinical situation, the potential benefit of androgen supplementation or stimulation of theca cells by LH-activity products are respectively discussed.

Mitocentricity

Worldwide, interest in mitochondria is constantly growing, as evidenced by scientific statistics, and studies of the functioning of these organelles are becoming more prevalent than studies of other cellular structures. In this analytical review, mitochondria are conditionally placed in a certain cellular center, which is responsible for both energy production and other non-energetic functions, without which the existence of not only the eukaryotic cell itself, but also the entire organism is impossible. Taking into account the high multifunctionality of mitochondria, such a fundamentally new scheme of cell functioning organization, including mitochondrial management of processes that determine cell survival and death, may be justified. Considering that this issue is dedicated to the memory of V. P. Skulachev, who can be called mitocentric, due to the history of his scientific activity almost entirely aimed at studying mitochondria, this work examines those aspects of mitochondrial functioning that were directly or indirectly the focus of attention of this outstanding scientist. We list all possible known mitochondrial functions, including membrane potential generation, synthesis of Fe-S clusters, steroid hormones, heme, fatty acids, and CO2. Special attention is paid to the participation of mitochondria in the formation and transport of water, as a powerful biochemical cellular and mitochondrial regulator. The history of research on reactive oxygen species that generate mitochondria is subject to significant analysis. In the section "Mitochondria in the center of death", special emphasis is placed on the analysis of what role and how mitochondria can play and determine the program of death of an organism (phenoptosis) and the contribution made to these studies by V. P. Skulachev.

Mitochondrial morphology in the mouse adrenal cortex: Influence of chronic psychosocial stress

Mitochondria within the adrenal cortex play a key role in synthesizing steroid hormones. The adrenal cortex is organized in three functionally specialized zones (glomerulosa, fasciculata, and reticularis) that produce different classes of steroid hormones in response to various stimuli, including psychosocial stress. Given that the functions and morphology of mitochondria are dynamically related and respond to stress, we applied transmission electron microscopy (TEM) to examine potential differences in mitochondrial morphology under basal and chronic psychosocial stress conditions. We used the chronic subordinate colony housing (CSC) paradigm, a murine model of chronic psychosocial stress. Our findings quantitatively define how mitochondrial morphology differs among each of the three adrenal cortex zones under basal conditions, and show that chronic psychosocial stress mainly affected mitochondria in the zona glomerulosa, shifting their morphology towards the more typical glucocorticoid-producing zona fasciculata mitochondrial phenotype. Analysis of adrenocortical lipid droplets that provide cholesterol for steroidogenesis showed that chronic psychosocial stress altered lipid droplet diameter, without affecting droplet number or inter-organellar mitochondria-lipid droplet interactions. Together, our findings support the hypothesis that each adrenal cortex layer is characterized by morphologically distinct mitochondria and that this adrenal zone-specific mitochondrial morphology is sensitive to environmental stimuli, including chronic psychosocial stressors. Further research is needed to define the role of these stress-induced changes in mitochondrial morphology, particularly in the zona glomerulosa, on stress resilience and related behaviors.

Diversity of Androgens; Comparison of Their Significance and Characteristics in Vertebrate Species

Androgen(s) is one of the sex steroids that are involved in many physiological phenomena of vertebrate species. Although androgens were originally identified as male sex hormones, it is well known now that they are also essential in females. As in the case of other steroid hormones, androgen is produced from cholesterol through serial enzymatic reactions. Although testis is a major tissue to produce androgens in all species, androgens are also produced in ovary and adrenal (interrenal tissue). Testosterone is the most common and famous androgen. It represents a major androgen both in males and females of almost vertebrate species. In addition, testosterone is a precursor for producing significant androgens such as11-ketotestosterone, 5α-dihydrotestosterone, 11-ketodihydrotestosterones and 15α-hydroxytestosterone in a species- or sex-dependent manner for their homeostasis. In this article, we will review the significance and characteristics of these androgens, following a description of the history of testosterone discovery and its synthetic pathways.

A narrative review on inflammaging and late-onset hypogonadism

The increasing life expectancy observed in recent years has resulted in a higher prevalence of late-onset hypogonadism (LOH) in older men. LOH is characterized by the decline in testosterone levels and can have significant impacts on physical and mental health. While the underlying causes of LOH are not fully understood, there is a growing interest in exploring the role of inflammaging in its development. Inflammaging is a concept that describes the chronic, low-grade, systemic inflammation that occurs as a result of aging. This inflammatory state has been implicated in the development of various age-related diseases. Several cellular and molecular mechanisms have been identified as contributors to inflammaging, including immune senescence, cellular senescence, autophagy defects, and mitochondrial dysfunction. Despite the extensive research on inflammaging, its relationship with LOH has not yet been thoroughly reviewed in the literature. To address this gap, we aim to review the latest findings related to inflammaging and its impact on the development of LOH. Additionally, we will explore interventions that target inflammaging as potential treatments for LOH.

Pyrroloquinoline Quinone Improves Ram Sperm Quality through Its Antioxidative Ability during Storage at 4 °C

Sperm motility is an important factor in the migration of sperm from the uterus to the oviduct. During sperm preservation in vitro, sperm generates excessive ROS that damages its function. This study aims to investigate whether the addition of pyrroloquinoline quinone (PQQ) to the diluted medium could improve chilled ram sperm quality, and then elucidates the mechanism. Ram semen was diluted with Tris-citric acid-glucose (TCG) medium containing different doses of PQQ (0 nM, 10 nM, 100 nM, 1000 nM, 10,000 nM), and stored at 4 °C. Sperm motility patterns, plasma membrane integrity, acrosome integrity, mitochondrial membrane potential, reactive oxygen species (ROS) levels, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and ATP levels were measured after preservation. Furthermore, the expressions of NADH dehydrogenase 1 (MT-ND1) and NADH dehydrogenase 6 (MT-ND6) in sperm were also detected by western blotting. In addition, sperm capacitation and the ability of sperm to bind to the zona pellucina were also evaluated. It was observed that the addition of PQQ significantly (p < 0.05) improved ram sperm motility, membrane integrity, and acrosome integrity during preservation. The percentage of sperm with high mitochondrial membrane potential in the PQQ treatment group was much higher than that in the control. In addition, supplementation of PQQ also decreased the sperm MDA and ROS levels, while increasing ATP levels. Interestingly, the levels of MT-ND1 and MT-ND6 protein in sperm treated with PQQ were also higher than that of the control. Furthermore, the addition of 100 nM PQQ to the medium decreased ROS damage in MT-ND1 and MT-ND6 proteins. The addition of 100 nM PQQ significantly (p < 0.05) increased protein tyrosine phosphorylation in ram sperm after induced capacitation. Furthermore, the value of the sperm-zona pellucida binding capacity in the 100 nM PQQ treatment group was also much higher than that of the control. Overall, during chilled ram- sperm preservation, PQQ protected ram sperm quality by quenching the ROS levels to reduce ROS damage and maintain sperm mitochondrial function, and preserved the sperm's high ability of fertilization.

The mitochondrial protease PARL is required for spermatogenesis

Mitochondrial function plays an important role in the maintenance of male fertility. However, the mechanisms underlying mitochondrial defect-related infertility remain mostly unclear. Here we show that a deficiency of PARL (Parl-/-), a mitochondrial protease, causes complete arrest of spermatogenesis during meiosis I. PARL deficiency led to severe downregulation of proteins of respiratory chain complex IV in testes that did not occur in other tested organs, causing a deficit in complex IV activity and ATP production. Furthermore, Parl-/- testes showed an almost complete loss of HSD17B3, a protein of the sER responsible for the last step in testosterone synthesis. While testosterone production appeared to be restored by overexpression of HSD17B12, loss of the canonical testosterone synthesis led to an upregulation of luteinizing hormone (LH) and of LH-regulated responses. These results suggest an important impact of the downstream regulation of mitochondrial defects that manifest in a cell-type-specific manner and extend beyond mitochondria.

Drp1 regulated PINK1-dependent mitophagy protected duck follicular granulosa cells from acute heat stress injury

The mitochondrial quality control system is crucial in maintaining cellular homeostasis during environmental stress. Granulosa cells are the main cells secreting steroid hormones, and mitochondria are the key organelles for steroid hormone synthesis. The impact of the mitochondrial quality control system on granulosa cells' steroid hormone synthesis and survival under heat stress is still unclear. Here, we showed that acute heat stress induces mitochondrial damage and significantly increases the number of mitophagy-like vesicles in the cytoplasm of duck ovary granulosa cells at the ultra-structural level. Meanwhile, we also found heat stress significantly increased mitochondrial fission and mitophagy-related protein expression levels both in vivo and in vitro. Furthermore, by confocal fluorescence analysis, we discovered that LC3 was distributed spot-like manner near the nucleus in the heat treatment group, and the LC3 spots and lysosomes were colocalized with Mito-Tracker in the heat treatment group. We further detected the mitophagy-related protein in the cytoplasm and mitochondria, respectively. Results showed that the PINK1 protein was significantly increased both in cytoplasm and mitochondria, while the LC3-Ⅱ/LC3-Ⅰ ratio increase only occurred in mitochondrial. In addition, the autophagy protein induced by acute heat treatment was effectively inhibited by the mitophagy inhibitor CysA. Finally, we demonstrated that the alteration of cellular mitophagy by siRNA interference with Drp1 and PINK1 inhibited the steroid synthesis of granulosa cells and increased cell apoptosis. Study provides strong evidence that the Drp1 regulated PINK1-dependent mitophagy pathway protects follicular granulosa cells from acute heat stress-induced injury.

Autophagy-related 7 proteindependent autophagy mediates resveratrol-caused upregulation of mitochondrial biogenesis and steroidogenesis in aged Leydig cell

BACKGROUND

Mitochondrial dysfunction may contribute to decreased testosterone synthesis in aged Leydig cells. Resveratrol (RSV) as an antioxidant has been shown to exhibit multiple positive effects on mitochondrion, where steroidogenesis takes place. Whether RSV can improve steroidogenesis in aged testis is still unknown. This study investigates the effect of RSV on testosterone production during aging and corresponding changes in mitochondrial biogenesis and autophagy activity, which are closely associated with steroidogenesis. Whether ATG7, an important autophagy-related protein, functions in RSV-treated aged Leydig cells will also be explored.

METHODS AND RESULTS

Two-month-old male C57BL/6 mice were fed for 16 months by customized regular diet with or without RSV as diet supplement. Leydig cell line TM3 cells were treated with D-galactose to induce senescence, followed with or without RSV treatment. Results found that RSV supplement increased testosterone production in both aged mice and D-galactose-induced senescent Leydig cells. Western blot results revealed that RSV treatment elevated levels of steroidogenic rate-limiting enzymes StAR and 3β-HSD, as well as autophagy-related proteins LC3II, Beclin1, ATG5 and ATG7 and mitochondrial function-related proteins mtTFA and COXIV. However, after Atg7 was knocked down in senescent Leydig cells, even though RSV was added, levels of these proteins declined significantly, accompanied by decreased levels of mitochondrial transcript factors PGC-1α, mtTFA and NRF-1 and more fragmented mitochondria, demonstrating that Atg7 knockdown wrecked the protective effects of RSV on steroidogenesis in senescent Leydig cells.

CONCLUSION

ATG7-dependent autophagy plays a key role in RSV-brought testosterone production increase through regulating mitochondrial biogenesis in senescent Leydig cells.

Mitochondrial might: powering the peripartum for risk and resilience

The peripartum period, characterized by dynamic hormonal shifts and physiological adaptations, has been recognized as a potentially vulnerable period for the development of mood disorders such as postpartum depression (PPD). Stress is a well-established risk factor for developing PPD and is known to modulate mitochondrial function. While primarily known for their role in energy production, mitochondria also influence processes such as stress regulation, steroid hormone synthesis, glucocorticoid response, GABA metabolism, and immune modulation - all of which are crucial for healthy pregnancy and relevant to PPD pathology. While mitochondrial function has been implicated in other psychiatric illnesses, its role in peripartum stress and mental health remains largely unexplored, especially in relation to the brain. In this review, we first provide an overview of mitochondrial involvement in processes implicated in peripartum mood disorders, underscoring their potential role in mediating pathology. We then discuss clinical and preclinical studies of mitochondria in the context of peripartum stress and mental health, emphasizing the need for better understanding of this relationship. Finally, we propose mitochondria as biological mediators of resilience to peripartum mood disorders.

Local Effects of Steroid Hormones within the Bone Microenvironment

Steroid hormone production via the adrenal cortex, gonads, and placenta (so-called glandular steroidogenesis) is responsible for the endocrine control of the body's homeostasis and is organized by a feedback regulatory mechanism based on the hypothalamus-pituitary-steroidogenic gland axis. On the other hand, recently discovered extraglandular steroidogenesis occurring locally in different tissues is instead linked to paracrine or autocrine signaling, and it is independent of the control by the hypothalamus and pituitary glands. Bone cells, such as bone-forming osteoblasts, osteoblast-derived osteocytes, and bone-resorbing osteoclasts, respond to steroid hormones produced by both glandular and extraglandular steroidogenesis. Recently, new techniques to identify steroid hormones, as well as synthetic steroids and steroidogenesis inhibitors, have been introduced, which greatly empowered steroid hormone research. Based on recent literature and new advances in the field, here we review the local role of steroid hormones in regulating bone homeostasis and skeletal lesion formation. The novel idea of extraglandular steroidogenesis occurring within the skeletal system raises the possibility of the development of new therapies for the treatment of bone diseases.

Bisphenol S and F affect cell cycle distribution and steroidogenic activity of human ovarian granulosa cells, but not primary granulosa tumour cells

Bisphenol S (BPS) and F (BPF), a new generation of bisphenols (BPs), are the main substitutes for bisphenol A (BPA). Both have been detected in human body fluids. Importantly, bisphenols are structurally similar to oestrogen, the main sex hormone in females. Because bisphenols bind to nuclear oestrogen receptors (ESR1 and ESR2) and to membrane G-coupled receptor 30 (GPR30), they can disrupt ovarian function. Here, we reveal the molecular mechanism underlying the effects of BPS and BPF on the cell cycle and steroidogenesis in the human ovarian granulosa cell (GC) line HGrC1. We show that BPS and BPF arrest GCs at the G0/G1 phase by inducing expression of cyclin D2, an important event that triggers maximal steroid synthesis in response to the BPS and BPF. We used pharmacological inhibitors to show that BPS and BPF, despite acting via already described pathways, also stimulate steroid secretion via IGF1R pathways in HGrC1 cells. Moreover, we identified differences critical to bisphenols response between normal (HGrC1) and primary tumour granulosa (COV434) cells, that enable COV434 cells to be more resistant to bisphenols. Overall, the data suggest that BPS and BPF drive steroidogenesis in human ovarian GCs by affecting the cell cycle. Furthermore, the results indicate that BPS and BPF act not only via the classical and non-classical ESR pathways, but also via the IGF1R pathway.

Expression of cholesterol synthesis and steroidogenic markers in females of the Chinese brown frog (Rana dybowskii) during prespawning and prehibernation

The oviduct of the Chinese brown frog (Rana dybowskii) expands in prehibernation rather than in prespawning, which is one of the physiological phenomena that occur in the preparation for hibernation. Steroid hormones are known to regulate oviductal development. Cholesterol synthesis and steroidogenesis may play an important role in the expansion of the oviduct before hibernation. In this study, we investigated the expression patterns of the markers that are involved in the de novo steroid synthesis pathway in the oviduct of R. dybowskii during prespawning and prehibernation. According to histological analysis, the oviduct of R. dybowskii contains epithelial cells, glandular cells, and tubule lumens. During prehibernation, oviductal pipe diameter and weight were significantly larger than during prespawning. 3-Hydroxy-3-methylglutaryl CoA reductase (HMGCR), low-density lipoprotein receptor (LDLR), steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) were detected in epithelial cells in prehibernation and glandular cells during prespawning. HMGCR, LDLR, StAR, and P450scc protein expression levels were higher in prehibernation than during prespawning, but the SF-1 protein expression level did not significantly differ. HMGCR, LDLR, StAR, P450scc (CYP11A1), and SF-1 (NR5A1) mRNA expression levels were significantly higher in prehibernation compared with prespawning. The transcriptome results showed that the steroid synthesis pathway was highly expressed during prehibernation. Existing results indicate that the oviduct is able to synthesize steroid hormones using cholesterol, and that steroid hormones may affect the oviductal functions of R. dybowskii.

Multi-omics analysis revealed the mitochondrial-targeted drug combination to suppress the development of lung cancer

PURPOSE

The incidence and mortality of lung cancer are continuously rising in recent years. Mitochondrial energy metabolism malfunction is found to be crucial in cancer proliferation and bioenergetic reprogramming, especially for lung cancer. In this study, we attempted to use mitochondrial-targeted drug therapy to change the energy metabolism pattern of cancer cells to inhibit the development of lung cancer, and investigated its mechanism of action and key targets through multi-omics studies.

METHODS

In this study, we established the in vivo tumor mouse mode, treated mice with multiple mitochondrial-targeted drug combinations and DDP, severally. Then, we investigated the differences between the 7-drug group with the control group and the DDP treatment group by transcriptomics, proteomics and metabolomics to find the therapeutic targets.

RESULTS

We found that mitochondria-targeting drug cocktail therapy, especially the 7-drug regimen, effectively improved mitochondrial metabolism, changed energy supply patterns in lung cancer cells, significantly increased NK cells in tumor tissues, and decreased tumor markers in plasma. Multi-omics analysis informed that the combination of 7-drug could up-regulate mitochondrial oxidative phosphorylation, ATP synthesis and autophagy related genes, and down-regulate proliferation and immune-related genes compared with the control group. By further mapping the protein interaction network, we identified a key target for 7-drug therapy to reverse tumor metabolic reprogramming and validated it in metabolomics.

CONCLUSIONS

Mitochondrial-targeted drug cocktail therapy can effectively inhibit the occurrence and development of tumors, through the reprogramming of energy metabolism and the increase in immune cells in tumor tissues. Thus, we provide a novel approach for the treatment of lung cancer and present evidence-based clues for the combined use of targeted mitochondrial drugs.

Perfluorooctanoic acid (PFOA) inhibits steroidogenesis and mitochondrial function in bovine granulosa cells in vitro

Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant. Due to the ubiquitous presence of PFOA in the environment, the impacts of PFOA exposure not only affect human reproductive health but may also affect livestock reproductive health. The focus of this study was to determine the effects of PFOA on the physiological functions of bovine granulosa cells in vitro. Primary bovine granulosa cells were exposed to 0, 4, and 40 μM PFOA for 48 and 96 h followed by analysis of granulosa cell function including cell viability, steroidogenesis, and mitochondrial activity. Results revealed that PFOA inhibited steroid hormone secretion and altered the expression of key enzymes required for steroidogenesis. Gene expression analysis revealed decreases in mRNA transcripts for CYP11A1, HSD3B, and CYP19A1 and an increase in STAR expression after PFOA exposure. Similarly, PFOA decreased levels of CYP11A1 and CYP19A1 protein. PFOA did not impact live cell number, alter the cell cycle, or induce apoptosis, although it reduced metabolic activity, indicative of mitochondrial dysfunction. We observed that PFOA treatment caused a loss of mitochondrial membrane potential and increases in PINK protein expression, suggestive of mitophagy and mitochondrial damage. Further analysis revealed that these changes were associated with increased levels of reactive oxygen species. Expression of autophagy related proteins phosphoULK1 and LAMP2 were increased after PFOA exposure, in addition to an increased abundance of lysosomes, characteristic of increased autophagy. Taken together, these findings suggest that PFOA can negatively impact granulosa cell steroidogenesis via mitochondrial dysfunction.

Adrenocortical function in patients with Single Large Scale Mitochondrial DNA Deletions: a retrospective single centre cohort study

OBJECTIVE

Single Large Scale Mitochondrial DNA Deletions (SLSMDs), Pearson Syndrome (PS) and Kearns-Sayre Syndrome (KSS), are systemic diseases with multiple endocrine abnormalities. The adrenocortical function has not been systematically investigated with a few anecdotal reports of overt adrenal insufficiency (AI). The study aimed to assess the adrenocortical function in a large cohort of SLSMDs.

DESIGN AND METHODS

A retrospective monocentric longitudinal study involved a cohort of 18 SLSMDs patients. Adrenocortical function was evaluated by baseline adrenocorticotrophic hormone (ACTH) and cortisol measurements and by high- (HDT) and low-dose (LDT) ACTH stimulation tests and compared with 92 healthy controls (HC).

RESULTS

Baseline adrenocortical function was impaired in 39% of patients and by the end of the study, 66% of PS and 25% of KSS showed an insufficient increase after ACTH stimulation, with cortisol deficiency due to primary AI in most PS and subclinical AI in KSS. Symptomatic AI was recorded in 44% of patients. Peak cortisol levels after ACTH stimulation tests were significantly lower in patients than in HC (P < .0001), with a more reduced response to LDT vs HDT (P < .05).

CONCLUSIONS

Our study highlights that cortisol deficiency due to primary AI represents a relevant part of the clinical spectrum in SLSMDs, with more severe impairment in PS than in KSS. Basal and after-stimulus assessment of adrenocortical axis should be early and regularly investigated to identify any degree of adrenocortical dysfunction. The study allowed the elaboration of a diagnostic process designed for the diagnosis, treatment, and follow-up of adrenocortical abnormalities in SLSMDs.

Seasonal expressions of the translocator protein (18 kDa), voltage-dependent anion channel, and steroidogenic acute regulatory protein in the scent glands of muskrats (Ondatra zibethicus)

Steroidogenesis machinery involves the steroidogenic acute regulatory protein (StAR), which regulates cholesterol transfer within the mitochondria, and the transport of cholesterol via a channel composed of 18-kDa translocator protein (TSPO), the voltage-dependent anion channel (VDAC) plus some accessory proteins. In this study, we investigated the immunolocalizations and expressions of StAR, TSPO, VDAC and cytochrome P450 side chain cleavage enzyme (P450scc, CYP11A1) in the scent glands of muskrats (Ondatra zibethicus) during the breeding and non-breeding periods. StAR, TSPO, VDAC and CYP11A1 were immunolocalized in the scent glandular, interstitial and epithelial cells in both breeding and non-breeding seasons with stronger immunostaining in the breeding season. The mRNA expression levels of StAR, TSPO, VDAC and CYP11A1 were higher in the scent glands of the breeding season than those of the non-breeding season. The circulating follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) as well as scent glandular T and dihydrotestosterone (DHT) concentrations were also significantly higher in the breeding season. Additionally, the transcriptomic study in the scent glands identified that differentially expressed genes might be related to the lipid metabolic process, integral component of membrane, and steroid hormone receptor activity and hormone activity using GO analysis. Further in vitro study verified that StAR, TSPO, VDAC and CYP11A1 expression levels increased significantly after human chorionic gonadotropin, hCG/FSH treatment compared with the control group. The KEGG pathway enriched by differentially expressed genes detected to be involved in endocrine system or amino acid metabolism. These findings suggested that the scent glands of the muskrats have ability to synthesize steroids de novo, and that the steroid hormones may have an important regulatory role in the scent glandular function via an autocrine/paracrine pathway.

Long-term reproductive effects of benzo(a)pyrene at environmentally relevant dose on juvenile female rats

Since studies on the reproductive consequences after the exposure to environmentally relevant doses of Benzo(a)pyrene (BaP) during critical stages of development are scarce, this study evaluated female reproductive parameters of adult rats exposed to a low dose of BaP during the juvenile phase. Female rats (Post-natal 21) were treated with BaP (0 or 0.1 µg/kg/day; gavage) for 21 consecutive days. During the treatment, no clinical signs of toxicity were observed. Nevertheless, the ages of vaginal opening and first estrus were anticipated by the BaP-exposure. At the sexual maturity, the juvenile exposure compromised the sexual behavior, as well as the placental efficiency, follicle stimulating hormone levels, placenta histological analysis, and ovarian follicle count. A decrease in erythrocyte, platelet, and lymphocyte counts also was observed in the exposed-females. Moreover, the dose of BaP used in this study was not able to produce estrogenic activity in vivo. These data showed that juvenile BaP-exposure, at environmentally relevant dose, compromised the female reproductive system, possibly by an endocrine deregulation; however, this requires further investigation.

Mitophagy involved the biological processes of hormones

Mitochondria fulfill vital functions in energy production, maintaining ion balance, and facilitating material metabolism. Mitochondria are sacrificed to protect cells or induce apoptosis when the body is under stress. The regulatory pathways of mitophagy include both ubiquitin-dependent and non-dependent pathways. The involvement of mitophagy has been demonstrated in the onset and progression of numerous diseases, highlighting its significant role. Endocrine hormones are chemical substances secreted by endocrine organs or endocrine cells, which participate in the regulation of physiological functions and internal environmental homeostasis of the body. Imbalances in endocrine hormones contribute to the development of various diseases. However, the precise impact of mitophagy on the physiological and pathological processes involving endocrine hormones remains unclear. This article aims to comprehensively overview recent advancements in understanding the mechanisms through which mitophagy regulates endocrine hormones.

A big picture of the mitochondria-mediated signals: From mitochondria to organism

Mitochondria, well-known for years as the powerhouse and biosynthetic center of the cell, are dynamic signaling organelles beyond their energy production and biosynthesis functions. The metabolic functions of mitochondria, playing an important role in various biological events both in physiological and stress conditions, transform them into important cellular stress sensors. Mitochondria constantly communicate with the rest of the cell and even from other cells to the organism, transmitting stress signals including oxidative and reductive stress or adaptive signals such as mitohormesis. Mitochondrial signal transduction has a vital function in regulating integrity of human genome, organelles, cells, and ultimately organism.

FDX1 regulates leydig cell ferroptosis mediates PM2.5-induced testicular dysfunction of mice

Epidemiological studies have established an association between chronic exposure to PM2.5 and male infertility. However, the underlying mechanisms were not fully revealed. In this study, we established mice models exposed to PM2.5 for 16 weeks, and a significant decrease in sperm quality accompanied by an increase in testosterone levels were observed after PM2.5 exposure. Moreover, treatment with ferrostatin-1 (Fer-1), a specific ferroptosis inhibitor, effectively mitigated PM2.5-induced testicular dysfunction in mice. And lipid peroxidation and ferritin accumulation were found to be significantly increased in Leydig cells of testes with a PM2.5-dose dependent manner. Further investigations revealed that TM-3 cells, a mouse Leydig cell line, were prone to ferroptosis after PM2.5 exposure, and the cell viability was partly rescued after the intervention of Fer-1. Furthermore, our results supported that the ferroptosis of TM-3 cells was attributed to the upregulation of ferredoxin 1 (FDX1), which was the protein transferring electrons to cytochrome P450 family 11 subfamily A member 1 to aid lysing cholesterol to pregnenolone at initial of steroidogenesis. Mechanically, PM2.5-induced FDX1 upregulation resulted in cellular ROS elevation and ferrous iron overload, which together initiated an autoxidation process of polyunsaturated fatty acids in the cell membrane of Leydig cells until the accumulated lipid peroxides triggered ferroptotic cell death. Simultaneously, upregulation of FDX1 promoted steroidogenesis and let to an increased level of testosterone. In summary, our work suggested that FDX1, a mediator involving steroidogenesis, was a key regulator in PM2.5-induced Leydig cells ferroptosis.

Expression of genes regulating cell division in porcine follicular granulosa cells

BACKGROUND

Cell cycle regulation influences the proliferation of granulosa cells and affects many processes related to ovarian folliclular growth and ovulation. Abnormal regulation of the cell cycle can lead to many diseases within the ovary. The aim of this study was to describe the expression profile of genes within granulosa cells, which are related to the formation of the cytoskeleton, organization of cell organelles inside the cell, and regulation of cell division. Established in vitro primary cultures from porcine ovarian follicle granulosa cells were maintained for 48, 96, 144 h and evaluated via microarray expression analysis.

RESULTS

Analyzed genes were assigned to 12 gene ontology groups "actin cytoskeleton organization", "actin filament organization", "actin filament-based process", "cell-matrix adhesion", "cell-substrate adhesion", "chromosome segregation", "chromosome separation", "cytoskeleton organization", "DNA integrity checkpoint", "DNA replication initiation", "organelle fision", "organelle organization". Among the genes with significantly changed expression, those whose role in processes within the ovary are selected for consideration. Genes with increased expression include (ITGA11, CNN1, CCl2, TPM2, ACTN1, VCAM-1, COL3A1, GSN, FRMD6, PLK2). Genes with reduced expression inlcude (KIF14, TACC3, ESPL1, CDC45, TTK, CDC20, CDK1, FBXO5, NEK2-NIMA, CCNE2). For the results obtained by microarray expressions, quantitative validation by RT-qPCR was performed.

CONCLUSIONS

The results indicated expression profile of genes, which can be considered as new molecular markers of cellular processes involved in signaling, cell structure organization. The expression profile of selected genes brings new insight into regulation of physiological processes in porcine follicular granulosa cells during primary in vitro culture.

Statin Use in Relation to COVID-19 and Other Respiratory Infections: Muscle and Other Considerations

Statins have been widely advocated for use in COVID-19 based on large favorable observational associations buttressed by theoretical expected benefits. However, past favorable associations of statins to pre-COVID-19 infection outcomes (also buttressed by theoretical benefits) were unsupported in meta-analysis of RCTs, RR = 1.00. Initial RCTs in COVID-19 appear to follow this trajectory. Healthy-user/tolerator effects and indication bias may explain these disparities. Moreover, cholesterol drops in proportion to infection severity, so less severely affected individuals may be selected for statin use, contributing to apparent favorable statin associations to outcomes. Cholesterol transports fat-soluble antioxidants and immune-protective vitamins. Statins impair mitochondrial function in those most reliant on coenzyme Q10 (a mevalonate pathway product also transported on cholesterol)-i.e., those with existing mitochondrial compromise, whom data suggest bear increased risks from both COVID-19 and from statins. Thus, statin risks of adverse outcomes are amplified in those patients at risk of poor COVID-19 outcomes-i.e., those in whom adjunctive statin therapy may most likely be given. High reported rates of rhabdomyolysis in hospitalized COVID-19 patients underscore the notion that statin-related risks as well as benefits must be considered. Advocacy for statins in COVID-19 should be suspended pending clear evidence of RCT benefits, with careful attention to risk modifiers.

Regulation of lipid droplets and cholesterol metabolism in adrenal cortical cells

The adrenal gland is composed of two distinctly different endocrine moieties. The interior medulla consists of neuroendocrine chromaffin cells that secrete catecholamines like adrenaline and noradrenaline, while the exterior cortex consists of steroidogenic cortical cells that produce steroid hormones, such as mineralocorticoids (aldosterone), glucocorticoids (cortisone and cortisol) and androgens. Synthesis of steroid hormones in cortical cells requires substantial amounts of cholesterol, which is the common precursor for steroidogenesis. Cortical cells may acquire cholesterol from de novo synthesis and uptake from circulating low- and high-density lipoprotein particles (LDL and HDL). As cholesterol is part of the plasma membrane in all mammalian cells and an important regulator of membrane fluidity, cellular levels of free cholesterol are tightly regulated. To ensure a robust supply of cholesterol for steroidogenesis and to avoid cholesterol toxicity, cortical cells store large amounts of cholesterol as cholesteryl esters in intracellular lipid droplets. Cortical steroidogenesis relies on both mobilization of cholesterol from lipid droplets and constant uptake of circulating cholesterol to replenish lipid droplet stores. This chapter will describe mechanisms involved in cholesterol uptake, cholesteryl ester synthesis, lipid droplet formation, hydrolysis of stored cholesteryl esters, as well as their impact on steroidogenesis. Additionally, animal models and human diseases characterized by altered cortical cholesteryl ester storage, with or without abnormal steroidogenesis, will be discussed.

Single-Cell RNA-Seq Identifies Pathways and Genes Contributing to the Hyperandrogenemia Associated with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenemia of ovarian thecal cell origin, resulting in anovulation/oligo-ovulation and infertility. Our previous studies established that ovarian theca cells isolated and propagated from ovaries of normal ovulatory women and women with PCOS have distinctive molecular and cellular signatures that underlie the increased androgen biosynthesis in PCOS. To evaluate differences between gene expression in single-cells from passaged cultures of theca cells from ovaries of normal ovulatory women and women with PCOS, we performed single-cell RNA sequencing (scRNA-seq). Results from these studies revealed differentially expressed pathways and genes involved in the acquisition of cholesterol, the precursor of steroid hormones, and steroidogenesis. Bulk RNA-seq and microarray studies confirmed the theca cell differential gene expression profiles. The expression profiles appear to be directed largely by increased levels or activity of the transcription factors SREBF1, which regulates genes involved in cholesterol acquisition (LDLR, LIPA, NPC1, CYP11A1, FDX1, and FDXR), and GATA6, which regulates expression of genes encoding steroidogenic enzymes (CYP17A1) in concert with other differentially expressed transcription factors (SP1, NR5A2). This study provides insights into the molecular mechanisms underlying the hyperandrogenemia associated with PCOS and highlights potential targets for molecular diagnosis and therapeutic intervention.

Autophagy regulates sex steroid hormone synthesis through lysosomal degradation of lipid droplets in human ovary and testis

Autophagy is an evolutionarily conserved process that aims to maintain the energy homeostasis of the cell by recycling long-lived proteins and organelles. Previous studies documented the role of autophagy in sex steroid hormone biosynthesis in different animal models and human testis. Here we demonstrate in this study that sex steroid hormones estrogen and progesterone are produced through the same autophagy-mediated mechanism in the human ovary in addition to the human testis. In brief, pharmacological inhibition and genetic interruption of autophagy through silencing of autophagy genes (Beclin1 and ATG5) via siRNA and shRNA technologies significantly reduced basal and gonadotropin-stimulated estradiol (E₂), progesterone (P₄) and testosterone (T) production in the ex vivo explant tissue culture of ovary and testis and primary and immortalized granulosa cells. Consistent with the findings of the previous works, we observed that lipophagy, a special form of autophagy, mediates the association of the lipid droplets (LD)s with lysosome to deliver the lipid cargo within the LDs to lysosomes for degradation in order to release free cholesterol required for steroid synthesis. Gonadotropin hormones are likely to augment the production of sex steroid hormones by upregulating the expression of autophagy genes, accelerating autophagic flux and promoting the association of LDs with autophagosome and lysosome. Moreover, we detected some aberrations at different steps of lipophagy-mediated P₄ production in the luteinized GCs of women with defective ovarian luteal function. The progression of autophagy and the fusion of the LDs with lysosome are markedly defective, along with reduced P₄ production in these patients. Our data, together with the findings of the previous works, may have significant clinical implications by opening a new avenue in understanding and treatment of a wide range of diseases, from reproductive disorders to sex steroid-producing neoplasms, sex steroid-dependent malignancies (breast, endometrium, prostate) and benign disorders (endometriosis).

Mitochondria are midfield players in steroid synthesis

Steroids are important membrane components and signaling metabolites and thus are required for cellular homeostasis. All mammalian cells retain the ability to uptake and synthesize steroids. Dysregulation of steroid levels leads to profound effects on cellular function and organismal health. Hence it comes as no surprise that steroid synthesis is tightly regulated. It is well established that the main site for steroid synthesis and regulation is the endoplasmic reticulum. However, mitochondria are essential for: (1) cholesterol production (the precursor of all steroids) by exporting citrate and; (2) the products of steroidogenesis (such as mineralocorticoids and glucocorticoids). In this review, we describe the midfield player role of mitochondria in steroid synthesis and bring the idea of mitochondria actively participating in steroid synthesis regulation. A better understanding of the mitochondrial regulatory roles in steroid synthesis would open new avenues to targeted approaches aiming to control steroid levels.

Characterization of trophoblast mitochondrial function and responses to testosterone treatment in ACH-3P cells

INTRODUCTION

Trophoblast mitochondria play important roles in placental energy metabolism, physiology and pathophysiology. Hyperandrogenism has been associated with mitochondrial abnormalities in pregnancy disorders such as pre-eclampsia, gestational diabetes, and intrauterine growth restriction, but the direct impacts of androgen exposure on placental mitochondrial function are unknown. Given the inherent limitations of studying the human placenta during pregnancy, trophoblast cell lines are routinely used to model placental biology in vitro. The aim of this study was to characterize mitochondrial respiratory function in four commonly used trophoblast cell lines to provide a basis for selecting one well-suited to investigating the impact of androgens on trophoblast mitochondrial function.

METHODS

Androgen receptor expression, mitochondrial respiration (JO₂) and reactive oxygen species (ROS) release rates were evaluated in three human trophoblast cell lines (ACH-3P, BeWo and Swan-71) and one immortalized ovine trophoblast line (iOTR) under basal and substrate-stimulated conditions using high-resolution fluorespirometry.

RESULTS

ACH-3P cells exhibited the greatest mitochondrial respiratory capacity and coupling efficiency of the four trophoblast lines tested, along with robust expression of androgen receptor protein that was found to co-localize with mitochondria by immunoblot and immunofluorescence. Acute testosterone administration (10 nM) tended to decrease ACH-3P mitochondrial JO₂ and increase ROS release, while chronic (7 days) testosterone exposure increased expression of mitochondrial proteins, JO₂, and ROS release.

DISCUSSION

These studies establish ACH-3P as a suitable cell line for investigating trophoblast mitochondrial function, and provide foundational evidence supporting links between hyperandrogenism and placental mitochondrial ROS production with potential relevance to several common pregnancy disorders.

Rab7a-mTORC1 signaling-mediated cholesterol trafficking from the lysosome to mitochondria ameliorates hepatic lipotoxicity induced by aflatoxin B1 exposure

Aflatoxin B1 (AFB1) is a common contaminant in many foodstuffs and is considered a public health concern worldwide due to its hepatotoxicity caused by lipid metabolism disorders. However, the molecular mechanism underlying AFB1-induced lipotoxicity-dependent liver injury via regulating cholesterol metabolism remains unclear. We established a cholesterol trafficking disorder-mediated hepatic lipotoxicity model with AFB1 mixture exposure in vitro (HepaRG and HepG2 cells, 1.6 μM for 36 h) and in vivo (C57BL/6 mice, 3 mg kg^-1, i.g., every other day for 6 weeks). In vitro, the interaction between lysosomal Niemann-Pick type C1 (NPC1) protein and mitochondrial translocator protein (TSPO) regulated lipotoxicity induced by AFB1 mixture exposure, including lysosomal membrane permeabilization and mitochondria-dependent necroptosis. Moreover, the downregulation of lysosomal Ras-associated protein 7a (Rab7a) enhanced the mammalian target of rapamycin complex 1 (mTORC1)-mediated disorders of cholesterol trafficking from the lysosome to mitochondria. Furthermore, cholesterol trafficking disorder-mediated hepatic lipotoxicity induced by the low-dose level of AFB1 exposure was relieved by genetic or pharmaceutic activation of Rab7a to inhibit mTORC1 in vitro and ex vivo. In vivo, mTORC1 inhibitor (Torin1, 4 mg kg^-1, i.p., every other day for 3 weeks) alleviated the cholesterol trafficking disorder-mediated hepatic lipotoxicity via upregulating the molecular machinery of lysosomes and mitochondria contact mediated by NPC1 and TSPO interaction in the low dose of AFB1 exposure. Altogether, our data suggested a novel mechanism that lysosomal Rab7a-mTORC1 signaling determined the cholesterol trafficking regulated by NPC1-TSPO from the lysosome to mitochondria, which promoted hepatic lipotoxicity via lysosomal quality control and mitochondria-dependent necroptosis signaling pathways in chemical mixture exposure.

Multifaceted mitochondria: moving mitochondrial science beyond function and dysfunction

Mitochondria have cell-type specific phenotypes, perform dozens of interconnected functions and undergo dynamic and often reversible physiological recalibrations. Given their multifunctional and malleable nature, the frequently used terms 'mitochondrial function' and 'mitochondrial dysfunction' are misleading misnomers that fail to capture the complexity of mitochondrial biology. To increase the conceptual and experimental specificity in mitochondrial science, we propose a terminology system that distinguishes between (1) cell-dependent properties, (2) molecular features, (3) activities, (4) functions and (5) behaviours. A hierarchical terminology system that accurately captures the multifaceted nature of mitochondria will achieve three important outcomes. It will convey a more holistic picture of mitochondria as we teach the next generations of mitochondrial biologists, maximize progress in the rapidly expanding field of mitochondrial science, and also facilitate synergy with other disciplines. Improving specificity in the language around mitochondrial science is a step towards refining our understanding of the mechanisms by which this unique family of organelles contributes to cellular and organismal health.

Mitochondrial respiratory quiescence: A new model for examining the role of mitochondrial metabolism in development

Mitochondria are vital organelles with a central role in all aspects of cellular metabolism. As a means to support the ever-changing demands of the cell, mitochondria produce energy, drive biosynthetic processes, maintain redox homeostasis, and function as a hub for cell signaling. While mitochondria have been widely studied for their role in disease and metabolic dysfunction, this organelle has a continually evolving role in the regulation of development, wound repair, and regeneration. Mitochondrial metabolism dynamically changes as tissues transition through distinct phases of development. These organelles support the energetic and biosynthetic demands of developing cells and function as key structures that coordinate the nutrient status of the organism with developmental progression. This review will examine the mechanisms that link mitochondria to developmental processes. We will also examine the process of mitochondrial respiratory quiescence (MRQ), a novel mechanism for regulating cellular metabolism through the biochemical and physiological remodeling of mitochondria. Lastly, we will examine MRQ as a system to discover the mechanisms that drive mitochondrial remodeling during development.

Testicular impairment in Primary Adrenal Insufficiency caused by Nicotinamide Nucleotide Transhydrogenase (NNT) deficiency - a case report: implication of oxidative stress and importance of fertility preservation

INTRODUCTION

Nicotinamide nucleotide transhydrogenase (NNT) gene deficiency has recently been shown to be involved in Primary Adrenal Insufficiency (PAI). NNT encodes an inner mitochondrial membrane protein that produces large amounts of NADPH. NADPH is used in several biosynthesis pathways and the oxidoreduction of free radicals by the glutathione and thioredoxin systems in mitochondria. Patients with PAI due to NNT deficiency may also exhibit extra-adrenal manifestations, usually including gonadal impairment.

CASE REPORT

We present the case of a 35-year-old patient referred to our center for primary infertility with non-obstructive azoospermia, in a context of PAI and obesity. PAI genetic exploration carried out at the age of thirty revealed NNT deficiency due to the presence of two deleterious mutations (one on each allele) in the NNT gene. Scrotal ultrasound revealed a right Testicular Adrenal Rest Tumor (TART). Intensification of glucocorticoid therapy over the course of 8 months failed to reduce the TART volume or improve sperm production and endocrine function. No spermatozoa were found after surgical exploration of both testes, and subsequent histopathological analysis revealed bilateral Sertoli cell-only syndrome. A retrospective review of the hypothalamic-pituitary-gonadic axis hormonal assessment over 20 years showed progressive impairment of testicular function, accelerated during adulthood, leading to hypergonadotropic hypogonadism and non-obstructive azoospermia when the patient reached his thirties, while the PAI remained controlled over the same period.

CONCLUSION

This case report provides, for the first time, direct evidence of complete germ line loss in an azoospermic man with NNT deficiency. Additional data further support the hypothesis of a determinant role of oxidative cellular damage due to reactive oxygen species (ROS) imbalance in the severe gonadal impairment observed in this NNT-deficient patient. Early and regular evaluation of gonadal function should be performed in patients with PAI, especially with NNT deficiency, as soon as the patients reach puberty. Fertility preservation options should then be provided in early adulthood for these patients.

Disturb mitochondrial associated proteostasis: Neurodegeneration and imperfect ageing

The disturbance in mitochondrial functions and homeostasis are the major features of neuron degenerative conditions, like Parkinson’s disease, Amyotrophic Lateral Sclerosis, and Alzheimer’s disease, along with protein misfolding. The aberrantly folded proteins are known to link with impaired mitochondrial pathways, further contributing to disease pathogenesis. Despite their central significance, the implications of mitochondrial homeostasis disruption on other organelles and cellular processes remain insufficiently explored. Here, we have reviewed the dysfunction in mitochondrial physiology, under neuron degenerating conditions. The disease misfolded proteins impact quality control mechanisms of mitochondria, such as fission, fusion, mitophagy, and proteasomal clearance, to the detriment of neuron. The adversely affected mitochondrial functional roles, like oxidative phosphorylation, calcium homeostasis, and biomolecule synthesis as well as its axes and contacts with endoplasmic reticulum and lysosomes are also discussed. Mitochondria sense and respond to multiple cytotoxic stress to make cell adapt and survive, though chronic dysfunction leads to cell death. Mitochondria and their proteins can be candidates for biomarkers and therapeutic targets. Investigation of internetworking between mitochondria and neurodegeneration proteins can enhance our holistic understanding of such conditions and help in designing more targeted therapies.

Mitochondrial function and E2 synthesis are impaired following alteration of CLOCK gene expression in porcine ovarian granulosa cells

Circadian locomotor output cycles kaput (CLOCK) is a critical component of the mammalian circadian clock system and regulates ovarian physiology. However, the functions and mechanisms of CLOCK in porcine granulosa cells (GCs) are poorly understood. The present study focused on CLOCK's effects on estradiol synthesis. Similarity analysis showed that CLOCK is highly conserved between pigs and other species. The phylogenetic tree analysis indicated that porcine CLOCK was most closely related to that in Arabian camels. CLOCK significantly reduced E₂ synthesis in GCs. CLOCK reduced the expression of steroidogenesis-related genes at the mRNA and protein levels, including CYP19A1, CYP11A1, and StAR. CYP17A1 levels were significantly downregulated. We demonstrated that CLOCK dramatically decreased ATP content, mitochondrial copy number, and mitochondrial membrane potential (MMP) and increased reactive oxygen species levels in GCs. We observed that mitochondria were severely damaged with fuzzy and fractured cristae and swollen matrix. These findings suggest that mitochondrial function and E₂ synthesis are impaired following the alteration of CLOCK gene expression in porcine ovarian GCs.

Oxytocin modulates steroidogenesis-associated genes and estradiol levels in the placenta

Oxytocin (OXT) plays a significant role during pregnancy, especially toward the end of pregnancy. Some studies have reported that OXT is involved in the stimulation of steroidogenesis in several organs. However, the effects of OXT on placental steroidogenesis have not yet been established. In this study, we investigated the regulation of steroid hormones and steroidogenic enzymes by OXT-associated signaling in vitro and in vivo. OXT increased the gene expression of steroidogenic enzymes, which convert pregnenolone to progesterone and dehydroepiandrosterone (DHEA) in vitro. In OXT-administered pregnant rats, pregnenolone and DHEA levels were significantly enhanced in the plasma and the expression of the enzymes synthesizing DHEA, testosterone, and estradiol (E2) was increased in placental tissues. Furthermore, OXT was found to affect placental cell differentiation, which is closely related to steroid hormone synthesis. After treatment of the pregnant rats with atosiban, an antagonist of the OXT receptor, the concentration of E2 in the plasma and the expression of E2-synthesizing enzyme were reduced. This regulation may be due to OXT-mediated differentiation, because OXT increases the expression of corticotropin-releasing hormone, which is a biomarker of placental cell differentiation. Our findings suggest that OXT contributes to maintaining pregnancy by regulating the differentiation of placental cells and steroidogenesis during pregnancy.

Cross-talk between neurosteroid and endocannabinoid systems in cannabis addiction

Steroids and endocannabinoids are part of two modulatory systems and some evidence has shown their interconnections in several functions. Homeostasis is a common steady-state described in the body, which is settled by regulatory systems to counterbalance deregulated or allostatic set points towards an equilibrium. This regulation is of primary significance in the central nervous system for maintaining neuronal plasticity and preventing brain-related disorders. In this context, the recent discovery of the shutdown of the endocannabinoid system (ECS) overload by the neurosteroid pregnenolone has highlighted new endogenous mechanisms of ECS regulation related to cannabis-induced intoxication. These mechanisms involve a regulatory loop mediated by overactivation of the central type-1 cannabinoid receptor (CB1R), which triggers the production of its own regulator, pregnenolone. Therefore, this highlights a new process of regulation of steroidogenesis in the brain. Pregnenolone, long considered an inactive precursor of neurosteroids, can then act as an endogenous negative allosteric modulator of CB1R. The present review aims to shed light on a new framework for the role of ECS in the addictive characteristics of cannabis with the novel endogenous mechanism of ECS involving the neurosteroid pregnenolone. In addition, this new endogenous regulatory loop could provide a relevant therapeutic model in the current context of increasing recreational and medical use of cannabis.

The Comprehensive Steroidome in Complete TSPO/PBR Knockout Mice under Basal Conditions

The 18 kDa translocator protein (TSPO/PBR) is a multifunctional evolutionary highly conserved outer mitochondrial membrane protein. Decades of research has reported an obligatory role of TSPO/PBR in both mitochondrial cholesterol transport and, thus, steroid production. However, the strict dependency of steroidogenesis on TSPO/PBR has remained controversial. The aim of this study was to provide insight into the steroid profile in complete C57BL/6-^{Tspotm1GuWu(GuwiyangWurra)}-knockout male mice (TSPO-KO) under basal conditions. The steroidome in the brain, adrenal glands, testes and plasma was measured by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). We found that steroids present in wild-type (WT) mice were also detected in TSPO-KO mice, including pregnenolone (PREG), progestogens, mineralo-glucocorticosteroids and androgens. The concentrations of PREG and most metabolites were similar between genotypes, except a significant decrease in the levels of the 5α-reduced metabolites of progesterone (PROG) in adrenal glands and plasma and of the 5α-reduced metabolites of corticosterone (B) in plasma in TSPO-KO compared to WT animals, suggesting other regulatory functions for the TSPO/PBR. The expression levels of the voltage-dependent anion-selective channel (VDAC-1), CYP11A1 and 5α-reductase were not significantly different between both groups. Thus, the complete deletion of the tspo gene in male mice does not impair de novo steroidogenesis in vivo.

A prospective and comparative investigation of blood sFlt-1, P1GF, and niacin concentrations in women with premature ovarian insufficiency

OBJECTIVE

Endothelial dysfunction is an important component of preeclampsia like premature ovarian insufficiency (POI), and it is reported that placental growth factor (P1GF) and soluble fms-like tyrosine kinase receptor-1 (sFlt-1) levels are important in preeclampsia. Extra-placental sources for P1GF and sFlt-1 have also been identified, including various cell types. In animal models of POI, niacin treatment inhibited follicular apoptosis under hazardous conditions while significantly reducing cumulus cell apoptosis. The number of developing follicles also increased after niacin was given. This study was designed to determine blood sFlt-1, P1GF, and niacin concentrations in women with idiopathic POI (iPOI) compared with those of healthy women.

METHODS

The study comprised 45 women with iPOI and 45 healthy women. Blood was obtained and analyzed at the early follicular phase of the menstrual cycle and sFlt-1, P1GF, and niacin levels were measured using a commercially available enzyme-linked immunosorbent assay kit.

RESULTS

No significant differences were observed in the two groups according to the gravidity numbers, parity, abortion, live births, and menarche ages (p ≥ 0.05). In the iPOI group, the mean anti-mullerian hormone value was 0.03 ± 0.04 (min-max, 0.00-0.21) ng/ml. sFlt-1, P1GF, niacin levels, and also the sFlt-1/P1GF ratio were lower in the iPOI group (p < 0.01). A significant discriminative role of sFlt-1, P1GF, niacin levels, and the sFlt-1/P1GF ratio for the presence of iPOI, with cut-off values of 5.13, 10.28, 37.17, and 0.61 ng/ml, respectively, were reported in the receiver operating characteristics curve analysis.

CONCLUSIONS

Lower levels of P1GF, sFlt-1, niacin, and sFlt-1/P1GF ratios may be associated with the development of POI/iPOI. Further studies are required to better understand the etiopathogenesis of POI/iPOI.

CLINICAL TRIAL NUMBER

NCT04641624 (clinicaltrials.gov).

Mitochondrial stress and mitokines in aging

Mitokines are signaling molecules that enable communication of local mitochondrial stress to other mitochondria in distant cells and tissues. Among those molecules are FGF21, GDF15 (both expressed in the nucleus) and several mitochondrial-derived peptides, including humanin. Their responsiveness to mitochondrial stress induces mitokine-signaling in response for example to exercise, following mitochondrial challenges in skeletal muscle. Such signaling is emerging as an important mediator of exercise-derived and dietary strategy-related molecular and systemic health benefits, including healthy aging. A compensatory increase in mitokine synthesis and secretion could preserve mitochondrial function and overall cellular vitality. Conversely, resistance against mitokine actions may also develop. Alterations of mitokine-levels, and therefore of mitokine-related inter-tissue cross talk, are associated with general aging processes and could influence the development of age-related chronic metabolic, cardiovascular and neurological diseases; whether these changes contribute to aging or represent "rescue factors" remains to be conclusively shown. The aim of the present review is to summarize the expanding knowledge on mitokines, the potential to modulate them by lifestyle and their involvement in aging and age-related diseases. We highlight the importance of well-balanced mitokine-levels, the preventive and therapeutic properties of maintaining mitokine homeostasis and sensitivity of mitokine signaling but also the risks arising from the dysregulation of mitokines. While reduced mitokine levels may impair inter-organ crosstalk, also excessive mitokine concentrations can have deleterious consequences and are associated with conditions such as cancer and heart failure. Preservation of healthy mitokine signaling levels can be achieved by regular exercise and is associated with an increased lifespan.

Emerging Promise of Therapeutic Approaches Targeting Mitochondria in Neurodegenerative Disorders

Mitochondria are critical for homeostasis and metabolism in all cellular eukaryotes. Brain mitochondria are the primary source of fuel that supports many brain functions, including intracellular energy supply, cellular calcium regulation, regulation of limited cellular oxidative capacity, and control of cell death. Much evidence suggests that mitochondria play a central role in neurodegenerative disorders (NDDs) such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. Ongoing studies of NDDs have revealed that mitochondrial pathology is mainly found in inherited or irregular NDDs and is thought to be associated with the pathophysiological cycle of these disorders. Typical mitochondrial disturbances in NDDs include increased free radical production, decreased ATP synthesis, alterations in mitochondrial permeability, and mitochondrial DNA damage. The main objective of this review is to highlight the basic mitochondrial problems that occur in NDDs and discuss the use mitochondrial drugs, especially mitochondrial antioxidants, mitochondrial permeability transition blockade, and mitochondrial gene therapy, for the treatment and control of NDDs.

Organ Weights in NPC1 Mutant Mice Partly Normalized by Various Pharmacological Treatment Approaches

Niemann-Pick Type C1 (NPC1, MIM 257220) is a rare, progressive, lethal, inherited autosomal-recessive endolysosomal storage disease caused by mutations in the NPC1 leading to intracellular lipid storage. We analyzed mostly not jet known alterations of the weights of 14 different organs in the BALB/cNctr-Npc1^m1N/-J Jackson Npc1 mice in female and male Npc1^+/+ and Npc1^-/- mice under various treatment strategies. Mice were treated with (i) no therapy, (ii) vehicle injection, (iii) a combination of miglustat, allopregnanolone, and 2-hydroxypropyl-ß-cyclodextrin (HPßCD), (iv) miglustat, and (v) HPßCD alone starting at P7 and repeated weekly throughout life. The 12 respective male and female wild-type mice groups were evaluated in parallel. In total, 351 mice (176 Npc1^+/+, 175 Npc1^-/-) were dissected at P65. In both sexes, the body weights of None and Sham Npc1^-/- mice were lower than those of respective Npc1^+/+ mice. The influence of the Npc1 mutation and/or sex on the weights of various organs, however, differed considerably. In males, Npc1^+/+ and Npc1^-/- mice had comparable absolute weights of lungs, spleen, and adrenal glands. In Npc1^-/- mice, smaller weights of hearts, livers, kidneys, testes, vesicular, and scent glands were found. In female Npc1^-/- mice, ovaries, and uteri were significantly smaller. In Npc1^-/- mice, relative organ weights, i.e., normalized with body weights, were sex-specifically altered to different extents by the different therapies. The combination of miglustat, allopregnanolone, and the sterol chelator HPßCD partly normalized the weights of more organs than miglustat or HPßCD mono-therapies.