Sex steroid hormone function in the brain niche: Implications for brain metastatic colonization and progression

The Multienzyme Complex Nature of Dehydroepiandrosterone Sulfate Biosynthesis

Dehydroepiandrosterone (DHEA), a precursor of steroid sex hormones, is synthesized by steroid 17-alpha-hydroxylase/17,20-lyase (CYP17A1) with the participation of microsomal cytochrome b5 (CYB5A) and cytochrome P450 reductase (CPR), followed by sulfation by two cytosolic sulfotransferases, SULT1E1 and SULT2A1, for storage and transport to tissues in which its synthesis is not available. The involvement of CYP17A1 and SULTs in these successive reactions led us to consider the possible interaction of SULTs with DHEA-producing CYP17A1 and its redox partners. Text mining analysis, protein-protein network analysis, and gene co-expression analysis were performed to determine the relationships between SULTs and microsomal CYP isoforms. For the first time, using surface plasmon resonance, we detected interactions between CYP17A1 and SULT2A1 or SULT1E1. SULTs also interacted with CYB5A and CPR. The interaction parameters of SULT2A1/CYP17A1 and SULT2A1/CYB5A complexes seemed to be modulated by 3'-phosphoadenosine-5'-phosphosulfate (PAPS). Affinity purification, combined with mass spectrometry (AP-MS), allowed us to identify a spectrum of SULT1E1 potential protein partners, including CYB5A. We showed that the enzymatic activity of SULTs increased in the presence of only CYP17A1 or CYP17A1 and CYB5A mixture. The structures of CYP17A1/SULT1E1 and CYB5A/SULT1E1 complexes were predicted. Our data provide novel fundamental information about the organization of microsomal CYP-dependent macromolecular complexes.

Activation of testosterone-androgen receptor mediates cerebrovascular protection by photobiomodulation treatment in photothrombosis-induced stroke rats

RATIONALE

Numerous epidemiological studies have reported a link between low testosterone levels and an increased risk of cerebrovascular disease in men. However, there is ongoing controversy surrounding testosterone replacement therapy due to potential side effects. PBMT has been demonstrated to improve cerebrovascular function and promote testosterone synthesis in peripheral tissues. Despite this, the molecular mechanisms that could connect PBMT with testosterone and vascular function in the brain of photothrombosis (PT)-induced stroke rats remain largely unknown.

METHODS

We measured behavioral performance, cerebral blood flow (CBF), vascular permeability, and the expression of vascular-associated and apoptotic proteins in PT-induced stroke rats treated with flutamide and seven consecutive days of PBM treatment (350 mW, 808 nM, 2 min/day). To gain further insights into the mechanism of PBM on testosterone synthesis, we used testosterone synthesis inhibitors to study their effects on bEND.3 cells.

RESULTS

We showed that PT stroke caused a decrease in cerebrovascular testosterone concentration, which was significantly increased by 7-day PBMT (808 nm, 350 mW/cm2 , 42 J/cm2 ). Furthermore, PBMT significantly increased cerebral blood flow (CBF) and the expression of vascular-associated proteins, while inhibiting vascular permeability and reducing endothelial cell apoptosis. This ultimately mitigated behavioral deficits in PT stroke rats. Notably, treatment with the androgen receptor antagonist flutamide reversed the beneficial effects of PBMT. Cellular experiments confirmed that PBMT inhibited cell apoptosis and increased vascular-associated protein expression in brain endothelial cell line (bEnd.3) subjected to oxygen-glucose deprivation (OGD). However, these effects were inhibited by flutamide. Moreover, mechanistic studies revealed that PBMT-induced testosterone synthesis in bEnd.3 cells was partly mediated by 17β-hydroxysteroid dehydrogenase 5 (17β-HSD5).

CONCLUSIONS

Our study provides evidence that PBMT attenuates cerebrovascular injury and behavioral deficits associated with testosterone/AR following ischemic stroke. Our findings suggest that PBMT may be a promising alternative approach for managing cerebrovascular diseases.

Proteomic and metabolomic signatures of U87 glioblastoma cells treated with cisplatin and/or paclitaxel

BACKGROUND

Glioblastoma (GBM) is a primary malignancy of the central nervous system and is classified as a grade IV astrocytoma by the World Health Organization (WHO). Although GBM rarely metastasizes, its prognosis remains poor. Moreover, the standard treatment for GBM, temozolomide (TMZ), is associated with chemoresistance, which is a major factor behind GBM-related deaths. Investigating drugs with repurposing potential in the context of GBM is worthwhile to bypass lengthy bench-to-bedside research. The field of omics has garnered significant interest in scientific research because of its potential to delineate the intricate regulatory network underlying tumor development. In particular, proteomic and metabolomic analyses are powerful approaches for the investigation of metabolic enzymes and intermediate metabolites since they represent the functional end of the cancer phenotype.

METHODS

We chose two of the most widely prescribed anticancer drugs, cisplatin and paclitaxel. To our knowledge, the current literature lacks studies examining their effects on metabolic and proteomic alterations in GBM. We employed the mass spectrometry technological platform 'UHPLC-Q-TOF-MS/MS' to examine the changes in the proteome and metabolome profiles of the U87 cell line with defined concentrations of cisplatin and/or paclitaxel via an untargeted approach.

RESULTS

A total of 1,419 distinct proteins and 90 metabolites were generated, and subsequent analysis was performed. We observed that upon treatment with cisplatin (9.5 μM), U87 cells exhibited apparent efforts to cope with this exogenous stressor, understanding the effect of paclitaxel (5.3 μM) on altering the transport machinery of the cell, and how the combination of cisplatin and/or paclitaxel suggests potential interactions with promising benefits in GBM therapeutics.

CONCLUSION

Our research provides a detailed map of alterations in response to cisplatin and paclitaxel treatment, provides crucial insights into the molecular basis of their action, and paves the way for further research to identify molecular targets for this elusive malignancy.

Disruption of neurosteroid synthesis and release by tris(2,3-dibromopropyl)isocyanurate in primary mouse cortical astrocytes in vitro

Neurosteroidogenesis in astrocytes is crucial for the proper development and functioning of the brain. During this process, key neurohormones such as progesterone (P4 ), testosterone (T), and estradiol (E2 ) are produced. Proper production and release of neurosteroids can be affected by substances referred to as endocrine-disrupting compounds (EDCs). Tris-(2,3-dibromopropyl)isocyanurate (TBC) is a representative of novel brominated flame retardants used to stop ignition or reduce fire-related property damage to plastics, polyolefin, polyphenyl alkene, unsaturated polyester, synthetic rubber, and fibers. Interestingly, previous studies have shown that TBC can enhance the proliferation of estradiol-sensitive breast cancers in vitro, which suggests that TBC has EDC properties. Therefore, given the suspected endocrine-disrupting properties of TBC, the aim of the present study was to determine the impact of TBC on the neurosteroid (P4 , T, and E2 ) production and secretion as well as the mRNA expression of key enzymes involved in its production in mouse astrocytes in vitro. Our paper shows that TBC increases P4 production with a strong decrease in T production, which is accompanied by a decrease in Cyp17a1 mRNA expression, that is, the main enzyme metabolizing P4 to T. Moreover, TBC in both studied concentrations increases P4 secretion in the culture medium. Finally, our studies have demonstrated an increase in the expression of Cyp19a1 mRNA, an enzyme metabolizing T to E2 , with a simultaneous increase in the amount of E2 in cells. Our data clearly show that TBC in an in vitro environment acts as EDCs, which may lead to serious consequences for the proper development and functioning of the brain.

Melatonin Prevents Depression but Not Anxiety-like Behavior Produced by the Chemotherapeutic Agent Temozolomide: Implication of Doublecortin Cells and Hilar Oligodendrocytes

Melatonin is a hormone synthesized by the pineal gland with neuroprotective and neurodevelopmental effects. Also, melatonin acts as an antidepressant by modulating the generation of new neurons in the dentate gyrus of the hippocampus. The positive effects of melatonin on behavior and neural development may suggest it is used for reverting stress but also for the alterations produced by chemotherapeutic drugs influencing behavior and brain plasticity. In this sense, temozolomide, an alkylating/anti-proliferating agent used in treating brain cancer, is associated with decreased cognitive functions and depression. We hypothesized that melatonin might prevent the effects of temozolomide on depression- and anxiety-like behavior by modulating some aspects of the neurogenic process in adult Balb/C mice. Mice were treated with temozolomide (25 mg/kg) for three days of two weeks, followed by melatonin (8 mg/kg) for fourteen days. Temozolomide produced short- and long-term decrements in cell proliferation (Ki67-positive cells: 54.89% and 53.38%, respectively) and intermediate stages of the neurogenic process (doublecortin-positive cells: 68.23% and 50.08%, respectively). However, melatonin prevented the long-term effects of temozolomide with the increased number of doublecortin-positive cells (47.21%) and the immunoreactivity of 2' 3'-Cyclic-nucleotide-3 phosphodiesterase (CNPase: 82.66%), an enzyme expressed by mature oligodendrocytes, in the hilar portion of the dentate gyrus. The effects of melatonin in the temozolomide group occurred with decreased immobility in the forced swim test (45.55%) but not anxiety-like behavior. Thus, our results suggest that melatonin prevents the harmful effects of temozolomide by modulating doublecortin cells, hilar oligodendrocytes, and depression-like behavior tested in the forced swim test. Our study could point out melatonin's beneficial effects for counteracting temozolomide's side effects.

Molecular mechanisms of sex hormones in the development and progression of Alzheimer's disease

Alzheimer's disease (AD) is a form of brain disorder characterized by various pathological changes in the brain. Numerous studies have shown that sex hormones are involved in the disease. For instance, progesterone, estrogen, and testosterone are well-known steroid sex hormones that play an essential role in AD pathogenesis. The Gender-dependency of AD is attributed to the effect of these hormones on the brain, which plays a neuroprotective role. In recent years, much research has been performed on the protective role of these hormones against nerve cell damage, which are promising for AD management. Hence, in the current review, we aim to decipher the protective role of steroid hormones in AD. Accordingly, we will discuss their functional mechanisms at the genomic and non-genomic scales.

Hijacking Sexual Immuno-Privilege in GBM-An Immuno-Evasion Strategy

Regulatory T-cells (Tregs) are immunosuppressive T-cells, which arrest immune responses to 'Self' tissues. Some immunosuppressive Tregs that recognize seminal epitopes suppress immune responses to the proteins in semen, in both men and women. We postulated that GBMs express reproductive-associated proteins to manipulate reproductive Tregs and to gain immune privilege. We analyzed four GBM transcriptome databases representing ≈900 tumors for hypoxia-responsive Tregs, steroidogenic pathways, and sperm/testicular and placenta-specific genes, stratifying tumors by expression. In silico analysis suggested that the presence of reproductive-associated Tregs in GBM tumors was associated with worse patient outcomes. These tumors have an androgenic signature, express male-specific antigens, and attract reproductive-associated Related Orphan Receptor C (RORC)-Treg immunosuppressive cells. GBM patient sera were interrogated for the presence of anti-sperm/testicular antibodies, along with age-matched controls, utilizing monkey testicle sections. GBM patient serum contained anti-sperm/testicular antibodies at levels > six-fold that of controls. Myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) are associated with estrogenic tumors which appear to mimic placental tissue. We demonstrate that RORC-Tregs drive poor patient outcome, and Treg infiltration correlates strongly with androgen levels. Androgens support GBM expression of sperm/testicular proteins allowing Tregs from the patient's reproductive system to infiltrate the tumor. In contrast, estrogen appears responsible for MDSC/TAM immunosuppression.

The Use of Iron Oxide Nanoparticles to Reprogram Macrophage Responses and the Immunological Tumor Microenvironment

The synthesis and functionalization of iron oxide nanoparticles (IONPs) is versatile, which has enhanced the interest in studying them as theranostic agents over recent years. As IONPs begin to be used for different biomedical applications, it is important to know how they affect the immune system and its different cell types, especially their interaction with the macrophages that are involved in their clearance. How immune cells respond to therapeutic interventions can condition the systemic and local tissue response, and hence, the final therapeutic outcome. Thus, it is fundamental to understand the effects that IONPs have on the immune response, especially in cancer immunotherapy. The biological effects of IONPs may be the result of intrinsic features of their iron oxide core, inducing reactive oxygen species (ROS) and modulating intracellular redox and iron metabolism. Alternatively, their effects are driven by the nanoparticle coating, for example, through cell membrane receptor engagement. Indeed, exploiting these properties of IONPs could lead to the development of innovative therapies. In this review, after a presentation of the elements that make up the tumor immunological microenvironment, we will review and discuss what is currently known about the immunomodulatory mechanisms triggered by IONPs, mainly focusing on macrophage polarization and reprogramming. Consequently, we will discuss the implications of these findings in the context of plausible therapeutic scenarios for cancer immunotherapy.

3D Image Analysis of the Complete Ventricular-Subventricular Zone Stem Cell Niche Reveals Significant Vasculature Changes and Progenitor Deficits in Males Versus Females with Aging

With age, neural stem cell (NSC) function in the adult ventricular-subventricular zone (V-SVZ) declines, reducing memory and cognitive function in males; however, the impact on females is not well understood. To obtain a global view of how age and sex impact the mouse V-SVZ, we constructed 3D montages after multiplex immunostaining, and used computer-based 3D image analysis to quantify data across the entire niche at 2, 18, and 22 months. We discovered dramatic sex differences in the aging of the V-SVZ niche vasculature, which regulates NSC activity: females showed increased diameter but decreased vessel density with age, while males showed decreased diameter and increased tortuosity and vessel density. Accompanying these vascular changes, males showed significant decline in NSC numbers, progenitor cell proliferation, and more disorganized migrating neuroblast chains with age; however, females did not. By examining the entire 3D niche, we found significant sex differences, with females being relatively spared through very old age.