Estrogen anti-inflammatory activity in brain: a therapeutic opportunity for menopause and neurodegenerative diseases

Considering the role of estradiol in the psychoneuroimmunology of perimenopausal depression

In recent years, a burgeoning field of research has focused on women's mental health and psychiatric conditions associated with perinatal and postpartum periods. An emerging trend points to the link between hormone fluctuations during pregnancy and postpartum that have immunologic consequences in cases of perinatal depression and postpartum psychosis. The transition to menopause (or "perimenopause") has garnered comparatively less attention, but existing studies point to the influential interaction of hormonal and immune pathways. Moreover, the role of this cross talk in perturbing neural networks has been implicated in risk for cognitive decline, but relatively less work has focused on the depressed brain during perimenopause. This brief review brings a psychoneuroimmunology lens to depression during the perimenopausal period by providing an overview of existing knowledge and suggestions for future research to intertwine these bodies of work.

The communication mechanism of the gut-brain axis and its effect on central nervous system diseases: A systematic review

Gut microbiota is involved in intricate and active metabolic processes the host's brain function, especially its role in immune responses, secondary metabolism, and symbiotic connections with the host. Gut microbiota can promote the production of essential metabolites, neurotransmitters, and other neuroactive chemicals that affect the development and treatment of central nervous system diseases. This article introduces the relevant pathways and manners of the communication between the brain and gut, summarizes a comprehensive overview of the current research status of key gut microbiota metabolites that affect the functions of the nervous system, revealing those adverse factors that affect typical communication between the brain-gut axis, and outlining the efforts made by researchers to alleviate these neurological diseases through targeted microbial interventions. The relevant pathways and manners of communication between the brain and gut contribute to the experimental design of new treatment plans and drug development. The factors that may cause changes in gut microbiota and affect metabolites, as well as current intervention methods are summarized, which helps improve gut microbiota brain dialogue, prevent adverse triggering factors from interfering with the gut microbiota system, and minimize neuropathological changes.

Sex-specific modulating role of social support in the associations between oxidative stress, inflammation, and telomere length in older adults

Telomere length, a biomarker of human aging, is related to adverse health outcomes. Growing evidence indicates that oxidative stress and inflammation contributes to telomere shortening, whereas social support may protect from telomere shortening. Despite sex differences in telomere length and social support, little is known about whether there are sex differences in the relationship between oxidative stress/inflammation and telomere length, and sex-specific moderating roles of social support in older adults. Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002, this study assessed whether the associations between oxidative stress/inflammation and telomere length vary with sex and explored social support as a moderator in these associations among 2289 older adults. Oxidative stress was measured based on serum Gamma-glutamyl transferase (GGT), and inflammation was measured based on C-reactive protein (CRP). After adjusting for the covariates, GGT was significantly associated with telomere length in females only (β =  - 0.037, 95% CI =  - 0.070, - 0.005), while CRP was associated with telomere length in males only (β =  - 0.019, 95% CI =  - 0.035, - 0.002). Moreover, high social support mitigated the negative association between GGT and telomere length, which was more evident in females. Furthermore, social support moderated the association between CRP and telomere length in males aged 70 and above. Our findings indicated that biological mechanisms related to telomere length may vary with sex, while social support plays a sex-specific moderating role.

Effects of metal oxide inhalation on the transcription of some hormone receptors in the brain, examined in an in vivo mouse model

Respirable metal oxide nanoparticles in welding fumes pose significant health risks upon inhalation, potentially leading to neurodegenerative diseases. While the exact mechanisms remain unclear, it is evident that metal oxide nanoparticles can disrupt cellular functions, including metabolism and inflammatory responses after crossing the blood-brain barrier (BBB). Our study investigates the impact of manual metal arc welding fumes on hormone receptor transcription in an in vivo mouse model. After collecting samples from six different brain regions at 24 and 96 h upon exposure, we focused on expression levels of estrogen receptors (ERs), thyroid hormone receptors (TRs), and peroxisome proliferator-activated receptors (PPARs) due to their roles in modulating neuroprotective responses and neuroinflammatory processes. Analysis revealed differential susceptibility of brain regions to hormonal disruption induced by welding fumes, with the hypothalamus (HT) and olfactory bulb (OB) showing prominent changes in receptor expression. Considering ERs, 24 h sampling showed an elevation in OB, with later increases in both ERα and ERβ. HT showed significant ERβ change only by 96 h. TRs mirrored ER patterns, with notable changes in OB and less in HT. PPARγ followed TR trends, with early upregulation in HT and downregulation elsewhere. These findings suggest a compensatory response within the CNS aimed at mitigating neuroinflammatory effects, as evidenced by the upregulation of ERβ, TRα, and PPARγ. The coordinated increase in ERs, TRs, and PPARs in the hypothalamus and olfactory bulb also highlights their potential neuroprotective roles in response to welding fume exposure. Our results also support the theory of metal oxide penetration to the CNS via the lungs-blood-BBB pathway, making HT and OB more vulnerable to welding fume exposure.

Allopregnanolone and its antagonist modulate neuroinflammation and neurological impairment

Neuroinflammation accompanies several brain disorders, either as a secondary consequence or as a primary cause and may contribute importantly to disease pathogenesis. Neurosteroids which act as Positive Steroid Allosteric GABA-A receptor Modulators (Steroid-PAM) appear to modulate neuroinflammation and their levels in the brain may vary because of increased or decreased local production or import from the systemic circulation. The increased synthesis of steroid-PAMs is possibly due to increased expression of the mitochondrial cholesterol transporting protein (TSPO) in neuroinflammatory tissue, and reduced production may be due to changes in the enzymatic activity. Microglia and astrocytes play an important role in neuroinflammation, and their production of inflammatory mediators can be both activated and inhibited by steroid-PAMs and GABA. What is surprising is the finding that both allopregnanolone, a steroid-PAM, and golexanolone, a novel GABA-A receptor modulating steroid antagonist (GAMSA), can inhibit microglia and astrocyte activation and normalize their function. This review focuses on the role of steroid-PAMs in neuroinflammation and their importance in new therapeutic approaches to CNS and liver disease.

Neuroactive Steroids, Toll-like Receptors, and Neuroimmune Regulation: Insights into Their Impact on Neuropsychiatric Disorders

Pregnane neuroactive steroids, notably allopregnanolone and pregnenolone, exhibit efficacy in mitigating inflammatory signals triggered by toll-like receptor (TLR) activation, thus attenuating the production of inflammatory factors. Clinical studies highlight their therapeutic potential, particularly in conditions like postpartum depression (PPD), where the FDA-approved compound brexanolone, an intravenous formulation of allopregnanolone, effectively suppresses TLR-mediated inflammatory pathways, predicting symptom improvement. Additionally, pregnane neurosteroids exhibit trophic and anti-inflammatory properties, stimulating the production of vital trophic proteins and anti-inflammatory factors. Androstane neuroactive steroids, including estrogens and androgens, along with dehydroepiandrosterone (DHEA), display diverse effects on TLR expression and activation. Notably, androstenediol (ADIOL), an androstane neurosteroid, emerges as a potent anti-inflammatory agent, promising for therapeutic interventions. The dysregulation of immune responses via TLR signaling alongside reduced levels of endogenous neurosteroids significantly contributes to symptom severity across various neuropsychiatric disorders. Neuroactive steroids, such as allopregnanolone, demonstrate efficacy in alleviating symptoms of various neuropsychiatric disorders and modulating neuroimmune responses, offering potential intervention avenues. This review emphasizes the significant therapeutic potential of neuroactive steroids in modulating TLR signaling pathways, particularly in addressing inflammatory processes associated with neuropsychiatric disorders. It advances our understanding of the complex interplay between neuroactive steroids and immune responses, paving the way for personalized treatment strategies tailored to individual needs and providing insights for future research aimed at unraveling the intricacies of neuropsychiatric disorders.

The role of the brain renin-angiotensin system in Parkinson´s disease

The renin-angiotensin system (RAS) was classically considered a circulating hormonal system that regulates blood pressure. However, different tissues and organs, including the brain, have a local paracrine RAS. Mutual regulation between the dopaminergic system and RAS has been observed in several tissues. Dysregulation of these interactions leads to renal and cardiovascular diseases, as well as progression of dopaminergic neuron degeneration in a major brain center of dopamine/angiotensin interaction such as the nigrostriatal system. A decrease in the dopaminergic function induces upregulation of the angiotensin type-1 (AT1) receptor activity, leading to recovery of dopamine levels. However, AT1 receptor overactivity in dopaminergic neurons and microglial cells upregulates the cellular NADPH-oxidase-superoxide axis and Ca2+ release, which mediate several key events in oxidative stress, neuroinflammation, and α-synuclein aggregation, involved in Parkinson's disease (PD) pathogenesis. An intraneuronal antioxidative/anti-inflammatory RAS counteracts the effects of the pro-oxidative AT1 receptor overactivity. Consistent with this, an imbalance in RAS activity towards the pro-oxidative/pro-inflammatory AT1 receptor axis has been observed in the substantia nigra and striatum of several animal models of high vulnerability to dopaminergic degeneration. Interestingly, autoantibodies against angiotensin-converting enzyme 2 and AT1 receptors are increased in PD models and PD patients and contribute to blood-brain barrier (BBB) dysregulation and nigrostriatal pro-inflammatory RAS upregulation. Therapeutic strategies addressed to the modulation of brain RAS, by AT1 receptor blockers (ARBs) and/or activation of the antioxidative axis (AT2, Mas receptors), may be neuroprotective for individuals with a high risk of developing PD or in prodromal stages of PD to reduce progression of the disease.

Sericin Improves Memory Impairment Via Activation of the PKA-CREB-BDNF Signaling Pathway and Suppression of Oxidative Stress in Ovariectomized Mice

Menopause results in estrogen hormone deficiency which causes changes in brain morphology and cognitive impairments. The risk of breast and ovarian cancer increases with estrogen therapy. Thus, finding a substitute treatment option for women in menopause is necessary. In the current study, the impact of chronic sericin treatment (200 mg/kg/day for 6 weeks, gavage) on memory process, oxidative stress markers, synaptic neurotransmission, and acetylcholinesterase (AChE) activity in the hippocampus (HIP) of ovariectomized (OVX) mice was examined and compared to the effects of 17β-estradiol (Es; 20 µg/kg, s.c.). The results demonstrated that sericin and Es administration improved spatial and recognition memory of the OVX animals in the both Lashley III maze and novel object recognition tests. Moreover, sericin-treated OVX mice showed decreased ROS levels, increased endogenous antioxidant defense capacity, and decreased AChE activity in the HIP. Additionally, sericin and Es therapy up-regulated pre-and-post-synaptic protein markers and increased BDNF, CREB, and protein kinase A (PKA) protein expressions in the HIP of OVX mice. Overall, the activation of the PKA-CREB-BDNF signaling pathway by sericin can provide protection against OVX-induced cognitive dysfunction, making it a potential alternative for managing cognitive deficits in postmenopausal women.

Human monocyte subtype expression of neuroinflammation and regeneration-related genes is linked to age and sex

Stroke is a leading cause of disability and the third cause of death. The immune system plays an essential role in post-stroke recovery. After an ischemic stroke, monocytes infiltrate the injured brain tissue and can exacerbate or mitigate the damage. Ischemic stroke is more prevalent in the aged population, and the aging brain exhibits an altered immune response. There are also sex disparities in ischemic stroke incidence, outcomes, and recovery, and these differences may be hormone-driven and determined by genetic and epigenetic factors. Here, we studied whether human peripheral blood monocyte subtype (classical, intermediate, and non-classical) expression of neuronal inflammation- and regeneration-related genes depends on age and sex. A FACS analysis of blood samples from 44 volunteers (male and female, aged 28 to 98) showed that in contrast to other immune cells, the proportion of natural killer cells increased in females. The proportion of B-cells decreased in both sexes with age, and subtypes of monocytes were not linked to age or sex. Gene expression analysis by qPCR identified several genes differentially correlating with age and sex within different monocyte subtypes. Interestingly, ANXA1 and CD36 showed a consistent increase with aging in all monocytes, specifically in intermediate (CD36) and intermediate and non-classical (ANXA1) subtypes. Other genes (IL-1β, S100A8, TNFα, CD64, CD33, TGFβ1, TLR8, CD91) were differentially changed in monocyte subtypes with increased aging. Most age-dependent gene changes were differentially expressed in female monocytes. Our data shed light on the nuanced interplay of age and sex in shaping the expression of inflammation- and regeneration-related genes within distinct monocyte subtypes. Understanding these dynamics could pave the way for targeted interventions and personalized approaches in post-stroke care, particularly for the aging population and individuals of different sexes.

Sex Differences under Vitamin D Supplementation in an Animal Model of Progressive Multiple Sclerosis

A central role for vitamin D (VD) in immune modulation has recently been recognized linking VD insufficiency to autoimmune disorders that commonly exhibit sex-associated differences. Similar to other autoimmune diseases, there is a higher incidence of multiple sclerosis (MS) in women, but a poorer prognosis in men, often characterized by a more rapid progression. Although sex hormones are most likely involved, this phenomenon is still poorly understood. Oxidative stress, modulated by VD serum levels as well as sex hormones, may act as a contributing factor to demyelination and axonal damage in both MS and the corresponding preclinical models. In this study, we analyzed sex-associated differences and VD effects utilizing an animal model that recapitulates histopathological features of the progressive MS phase (PMS). In contrast to relapsing-remitting MS (RRMS), PMS has been poorly investigated in this context. Male (n = 50) and female (n = 46) Dark Agouti rats received either VD (400 IU per week; VD+) or standard rodent food without extra VD (VD-) from weaning onwards. Myelination, microglial activation, apoptotic cell death and neuronal viability were assessed using immunohistochemical markers in brain tissue. Additionally, we also used two different histological markers against oxidized lipids along with colorimetric methods to measure protective polyphenols (PP) and total antioxidative capacity (TAC) in serum. Neurofilament light chain serum levels (sNfL) were analyzed using single-molecule array (SIMOA) analysis. We found significant differences between female and male animals. Female rats exhibited a better TAC and higher amounts of PP. Additionally, females showed higher myelin preservation, lower microglial activation and better neuronal survival while showing more apoptotic cells than male rats. We even found a delay in reaching the peak of the disease in females. Overall, both sexes benefitted from VD supplementation, represented by significantly less cortical, neuroaxonal and oxidative damage. Unexpectedly, male rats had an even higher overall benefit, most likely due to differences in oxidative capacity and defense systems.

Mind the Gap: Unraveling the Intricate Dance Between Alzheimer's Disease and Related Dementias and Bone Health

PURPOSE OF REVIEW

This review examines the linked pathophysiology of Alzheimer's disease/related dementia (AD/ADRD) and bone disorders like osteoporosis. The emphasis is on "inflammaging"-a low-level inflammation common to both, and its implications in an aging population.

RECENT FINDINGS

Aging intensifies both ADRD and bone deterioration. Notably, ADRD patients have a heightened fracture risk, impacting morbidity and mortality, though it is uncertain if fractures worsen ADRD. Therapeutically, agents targeting inflammation pathways, especially Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and TNF-α, appear beneficial for both conditions. Additionally, treatments like Sirtuin 1 (SIRT-1), known for anti-inflammatory and neuroprotective properties, are gaining attention. The interconnectedness of AD/ADRD and bone health necessitates a unified treatment approach. By addressing shared mechanisms, we can potentially transform therapeutic strategies, enriching our understanding and refining care in our aging society. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Blood-brain Barrier and Neurovascular Unit Dysfunction in Parkinson's Disease: From Clinical Insights to Pathogenic Mechanisms and Novel Therapeutic Approaches

The blood-brain barrier (BBB) plays a crucial role in the central nervous system by tightly regulating the influx and efflux of biological substances between the brain parenchyma and peripheral circulation. Its restrictive nature acts as an obstacle to protect the brain from potentially noxious substances such as blood-borne toxins, immune cells, and pathogens. Thus, the maintenance of its structural and functional integrity is vital in the preservation of neuronal function and cellular homeostasis in the brain microenvironment. However, the barrier's foundation can become compromised during neurological or pathological conditions, which can result in dysregulated ionic homeostasis, impaired transport of nutrients, and accumulation of neurotoxins that eventually lead to irreversible neuronal loss. Initially, the BBB is thought to remain intact during neurodegenerative diseases, but accumulating evidence as of late has suggested the possible association of BBB dysfunction with Parkinson's disease (PD) pathology. The neurodegeneration occurring in PD is believed to stem from a myriad of pathogenic mechanisms, including tight junction alterations, abnormal angiogenesis, and dysfunctional BBB transporter mechanism, which ultimately causes altered BBB permeability. In this review, the major elements of the neurovascular unit (NVU) comprising the BBB are discussed, along with their role in the maintenance of barrier integrity and PD pathogenesis. We also elaborated on how the neuroendocrine system can influence the regulation of BBB function and PD pathogenesis. Several novel therapeutic approaches targeting the NVU components are explored to provide a fresh outlook on treatment options for PD.

Sex-oriented perspectives in immunopharmacology

Several immunopharmacological agents are effective in the treatment of cancer and immune-mediated conditions, with a favorable impact on life expectancy and clinical outcomes for a large number of patients. Nevertheless, response variation and undesirable effects of these drugs represent major issues, and overall efficacy remains unpredictable. Males and females show a distinct difference in immune system responses, with females generally mounting stronger responses to a variety of stimuli. Therefore, exploring sex differences in the efficacy and safety of immunopharmacological agents would strengthen the practice of precision medicine. As a pharmacological target highlight, programmed cell death 1 ligand 1 (PD-L1) is the first functionally characterized ligand of the coinhibitory programmed death receptor 1 (PD-1). The PD-L1/PD-1 crosstalk plays an important role in the immune response and is relevant in cancer, infectious and autoimmune disease. Sex differences in the response to immune checkpoint inhibitors are well documented, with male patients responding better than female patients. Similarly, higher efficacy of and adherence to tumor necrosis factor inhibitors in chronic inflammatory conditions including rheumatoid arthritis and Crohn's disease have been reported in male patients. The pharmacological basis of sex-specific responses to immune system modulating drugs is actively investigated in other settings such as stroke and type 1 diabetes. Advances in therapeutics targeting the endothelium could soon be wielded against autoimmunity and metabolic disorders. Based on the established sexual dimorphism in immune-related pathophysiology and disease presentation, sex-specific immunopharmacological protocols should be integrated into clinical guidelines.

Sex-specific adipose tissue's dynamic role in metabolic and inflammatory response following peripheral nerve injury

Epidemiological data and research highlight increased neuropathy and chronic pain prevalence among females, spanning metabolic and normometabolic contexts, including murine models. Prior findings demonstrated diverse immune and neuroimmune responses between genders in neuropathic pain (NeP), alongside distinct protein expression in sciatic nerves. This study unveils adipose tissue's (AT) role in sex-specific NeP responses after peripheral nerve injury. Metabolic assessments, metabolomics, energy expenditure evaluations, AT proteomic analyses, and adipokine mobilization depict distinct AT reactions to nerve damage. Females exhibit altered lipolysis, fatty acid oxidation, heightened energy expenditure, and augmented steroids secretion affecting glucose and insulin metabolism. Conversely, male neuropathy prompts glycolysis, reduced energy expenditure, and lowered unsaturated fatty acid levels. Males' AT promotes regenerative molecules, oxidative stress defense, and stimulates peroxisome proliferator-activated receptors (PPAR-γ) and adiponectin. This study underscores AT's pivotal role in regulating gender-specific inflammatory and metabolic responses to nerve injuries, shedding light on female NeP susceptibility determinants.

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties ("brain fog"), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions. Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms. Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Association Between the Dietary Inflammatory Index and the Risk of Fracture in Chinese Adults: Longitudinal Study

BACKGROUND

Chronic inflammation plays a crucial role in tissue injury, osteoporosis, and fracture. The dietary inflammatory index (DII) is a tool for assessing the potential for inflammation in the diet. However, the association between the DII and fractures remains controversial from previous studies.

OBJECTIVE

We aimed to explore the correlation between the DII and fracture risk in Chinese adults.

METHODS

We included 11,999 adults (5519 men and 6480 women) who were a part of the China Health and Nutrition Survey (1997-2015) prospective cohort. A 3-day, 24-hour meal review method was used to calculate the DII score. The fractures were identified using a questionnaire. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% CIs for fractures. Subgroup, sensitivity, and restricted cubic spline analyses were performed.

RESULTS

During the 18 years of follow-up (median follow-up 9.0 years), 463 men and 439 women developed fractures. The median DII score was 0.64 (IQR -1.74 to 1.46) for the total sample, 0.75 (IQR -1.68 to 1.50) for men, and 0.53 (IQR -1.79 to 1.42) for women. The DII score had a positive correlation with the risk of fracture among women but not among men. For men, after adjusting for covariates, the HRs for quintiles of DII were 1, 0.96 (95% CI 0.66-1.41), 1.05 (95% CI 0.74-1.49), 0.89 (95% CI 0.62-1.26), and 0.94 (95% CI 0.67-1.34; trend: P=.62). The HRs for women were 1, 1.13 (95% CI 0.72-1.79), 1.24 (95% CI 0.83-1.86), 1.51 (95% CI 1.02-2.22), and 1.62 (95% CI 1.10-2.39; trend: P=.004). The restricted cubic spline analysis showed a significant association between fracture risk and DII score in women (overall association: P=.01); as the DII scores were >0.53, HRs showed a significant upward trend. Women aged <50 years or who are nonsmokers, who are nondrinkers, or with nonabdominal obesity had a positive association between fracture risk and the DII score. In sensitivity analyses, after excluding people with diabetes or hypertension, there was still a positive association between fracture risk and the DII score in women. Among the DII components, the DII scores of protein (trend: P=.03), niacin (trend: P=.002), and iron (trend: P=.02) showed significant associations with the risk of fracture in women.

CONCLUSIONS

Proinflammatory diet consumption increased the fracture risk in Chinese women aged <50 years. The high consumption of anti-inflammatory foods and low consumption of proinflammatory foods may be an important strategy to prevent fractures in women.

Menopausal transition in multiple sclerosis: relationship with disease activity and brain volume measurements

Background

Recent evidence has shown a significant association between menopause and multiple sclerosis (MS) progression. This study investigated the possible role of menopause in influencing MS from clinical and neuroradiological perspectives. Notably, the possible association between menopause and brain atrophy has been evaluated.

Materials and methods

This study included women with MS whose ages ranged from 45 to 55 years. Demographic and clinical characteristics were collected, and the reproductive phase was defined as non-menopausal or menopausal based on the final menstrual period. Thus, MS activity over the past year was reported as the annualised relapse rate (ARR), and MRI activity (defined as new T2 lesions and/or the presence of gadolinium-enhancing lesions at the last MRI assessment in comparison with the MRI performed within the previous 12 months) were compared between non-menopausal women (non-MW) and menopausal women (MW). Volume measurements of the whole brain (WB), white matter (WM), grey matter (GM), and cortical GM were estimated using the SIENAX software, and the possible relationship with menopausal status was assessed by regression analysis.

Results

The study included 147 women with MS. Eighty-four (57.1%) were MW, with a mean age of 48.5 ± 4.3 years at menopause onset and a mean duration of menopause of 4.1 ± 1.1 years. When compared for ARR, MW reported a lower rate than the non-MW (ARR of 0.29 ± 0.4 vs. 0.52 ± 0.5; p < 0.01). MRI activity was observed in 13.1% of MW and 20.6% of non-MW (p = 0.03). Lower cortical GM volumes (578.1 ± 40.4 mL in MW vs. 596.9 ± 35.8 mL in non-MW; p < 0.01) have also been reported. Finally, multivariate analysis showed a significant association of lower ARR (p = 0.001) and cortical GM volume (p = 0.002) with menopausal status after correction for chronological age and other variables.

Discussion

Menopause may be an adverse prognostic factor of MS. Our preliminary results suggest that menopause may facilitate cortical GM atrophy, probably due to a decline in the neuroprotective effects of estrogen, with negative effects on MS evolution.

Ovariectomy in mice primes hippocampal microglia to exacerbate behavioral sickness responses

Estrogens are a group of steroid hormones that promote the development and maintenance of the female reproductive system and secondary sex characteristics. Estrogens also modulate immune responses; estrogen loss at menopause increases the risk of inflammatory disorders. Elevated inflammatory responses in the brain can lead to affective behavioral changes, which are characteristic of menopause. Thus, here we examined whether loss of estrogens sensitizes microglia, the primary innate immune cell of the brain, leading to changes in affective behaviors. To test this question, adult C57BL/6 mice underwent an ovariectomy to remove endogenous estrogens and then received estradiol hormone replacement or vehicle. After a one-month recovery, mice received an immune challenge with lipopolysaccharide (LPS) or vehicle control treatment and underwent behavioral testing. Ovariectomized, saline-treated mice exhibited reduced social investigation compared to sham-operated mice. Furthermore, ovariectomized mice that received LPS exhibited an exacerbated decrease in sucrose preference, which was ameliorated by estradiol replacement. These results indicate that ovariectomy modulates affective behaviors at baseline and in response to an inflammatory challenge. Ovariectomy-related behavioral changes were associated with downregulation of Cx3cr1, a microglial receptor that limits activation, suggesting that estrogen loss can disinhibit microglia to immune stimuli. Indeed, estradiol treatment reduced ovariectomy-induced increases in Il1b and Il6 expression after an immune challenge. Changes in microglial reactivity following ovariectomy are likely subtle, as overt changes in microglial morphology (e.g., soma size and branching) were limited. Collectively, these results suggest that a lack of estrogens may allow microglia to confer exaggerated neuroimmune responses, thereby raising vulnerability to adverse affective- and sickness-related behavioral changes.

Role of Estrogen Receptor α in Aging and Chronic Disease

Estrogen receptor alpha (ERα) plays a crucial role in reproductive function in both sexes. It also mediates cellular responses to estrogens in multiple nonreproductive organ systems, many of which regulate systemic metabolic homeostasis and inflammatory processes in mammals. The loss of estrogens and/or ERα agonism during aging is associated with the emergence of several comorbid conditions, particularly in females undergoing the menopausal transition. Emerging data also suggests that male mammals likely benefit from ERα agonism if done in a way that circumvents feminizing characteristics. This has led us, and others, to speculate that tissue-specific ERα agonism may hold therapeutic potential for curtailing aging and chronic disease burden in males and females that are at high-risk of cancer and/or cardiovascular events with traditional estrogen replacement therapies. In this mini-review, we emphasize the role of ERα in the brain and liver, summarizing recent evidence that indicates these two organs systems mediate the beneficial effects of estrogens on metabolism and inflammation during aging. We also discuss how 17α-estradiol administration elicits health benefits in an ERα-dependent manner, which provides proof-of-concept that ERα may be a druggable target for attenuating aging and age-related disease burden.

Chromosomal and gonadal factors regulate microglial sex effects in the aging brain

Biological sex contributes to phenotypic sex effects through genetic (sex chromosomal) and hormonal (gonadal) mechanisms. There are profound sex differences in the prevalence and progression of age-related brain diseases, including neurodegenerative diseases. Inflammation of neural tissue is one of the most consistent age-related phenotypes seen with healthy aging and disease. The pro-inflammatory environment of the aging brain has primarily been attributed to microglial reactivity and adoption of heterogeneous reactive states dependent upon intrinsic (i.e., sex) and extrinsic (i.e., age, disease state) factors. Here, we review sex effects in microglia across the lifespan, explore potential genetic and hormonal molecular mechanisms of microglial sex effects, and discuss currently available models and methods to study sex effects in the aging brain. Despite recent attention to this area, significant further research is needed to mechanistically understand the regulation of microglial sex effects across the lifespan, which may open new avenues for sex informed prevention and treatment strategies.

DHEA and Its Metabolites Reduce the Cytokines Involved in the Inflammatory Response and Fibrosis in Primary Biliary Cholangitis

Dehydroepiandrosterone (DHEA) is an abundant steroid and precursor of sex hormones. During aging, the reduction in DHEA synthesis causes a significant depletion of estrogens and androgens in different organs, such as the ovaries, brain, and liver. Primary Biliary Cholangitis (PBC) is a cholestatic liver disease that begins with immune-mediated bile duct damage, and is followed by liver fibrosis, and finally, cirrhosis. PBC primarily affects postmenopausal women, with an average age of diagnosis of 65 years, but younger women are also affected. Here, we analyzed the levels of DHEA, estradiol (E2), and estriol (E3) in the PBC sera of females at an age of diagnosis under 40 (n = 37) and above 65 (n = 29). Our results indicate that in PBC patients at an age of diagnosis under 40, E2 was significantly lower compared to that in healthy women. In contrast, the levels of DHEA and E3 were in a normal range. Furthermore, ELISA assays revealed that in PBC patients at an age of diagnosis above 65, the levels of DHEA, E2, and E3 significantly declined in comparison to those in younger patients. In addition, flow cytometry analysis showed that the level of IL-8 significantly decreased while the level of TNF-α increased in older PBC patients compared to younger ones. Moreover, we showed for the first time that the sulfonated form of DHEA, DHEA-S, reduces the levels of both pro-inflammatory interleukins, IL-8 and TNF-α, in PBC-like cholangiocytes (H69-miR506), while it diminishes the level of the pro-fibrotic interleukin, IL-13, in hepatocytes (Hep-G2). Finally, we demonstrated that the expression of the pro-fibrotic agent TGF-β significantly increased in both the early (F0–F3) and cirrhotic (F4) stages of PBC, and this elevation was accompanied by higher α-SMA expression.

Sex and Time: Important Variables for Understanding the Impact of Constant Darkness on Behavior, Brain, and Physiology

The circadian clock can coordinate, regulate and predict physiology and behavior in response to the standard light-dark (LD: 12 h light and 12 h dark) cycle. If we alter the LD cycle by exposing mice to constant darkness (DD: 00 h light and 24 h dark), it can perturb behavior, the brain, and associated physiological parameters. The length of DD exposure and the sex of experimental animals are crucial variables that could alter the impact of DD on the brain, behavior, and physiology, which have not yet been explored. We exposed mice to DD for three and five weeks and studied their impact on (1) behavior, (2) hormones, (3) the prefrontal cortex, and (4) metabolites in male and female mice. We also studied the effect of three weeks of standard light-dark cycle restoration after five weeks of DD on the parameters mentioned above. We found that DD exposure was associated with anxiety-like behavior, increased corticosterone and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), downregulated neurotrophins (BDNF and NGF), and altered metabolites profile in a duration of DD exposure and sex-dependent manner. Females showed a more robust adaptation than males under DD exposure. Three weeks of restoration was adequate to establish homeostasis in both sexes. To the best of our knowledge, this study is the first of its kind to look at how DD exposure impacts physiology and behavior as a function of sex- and time. These findings would have translational value and may help in establishing sex-specific interventions for addressing DD-related psychological issues.

The Interaction Between NF-κB and Estrogen in Alzheimer's Disease

Post-menopausal women are at a higher risk of developing Alzheimer's disease (AD) than males. The higher rates of AD in women are associated with the sharp decline in the estrogen levels after menopause. Estrogen has been shown to downregulate inflammatory cytokines in the central nervous system (CNS), which has a neuroprotective role against neurodegenerative diseases including AD. Sustained neuroinflammation is associated with neurodegeneration and contributes to AD. Nuclear factor kappa-B (NF-κB) is a transcription factor involved with the modulation of inflammation and interacts with estrogen to influence the progression of AD. Application of 17β-estradiol (E2) has been shown to inhibit NF-κB, thereby reducing transcription of NF-κB target genes. Despite accumulating evidence showing that estrogens have beneficial effects in pre-clinical AD studies, there are mixed results with hormone replacement therapy in clinical trials. Furthering our understanding of how NF-κB interacts with estrogen and alters the progression of neurodegenerative disorders including AD, should be beneficial and result in the development of novel therapeutics.

Sex differences in the association of plasma cytokines and neurocognition in first-episode major depressive disorder

BACKGROUND

Peripheral cytokines were found to be involved in the pathophysiology of neurocognition in individuals with major depressive disorder (MDD). However, whether there are sex differences in this association between cytokines and cognition in MDD remains unknown. Our aim is to examine sex differences in the relationship between plasma cytokines and cognition in MDD.

METHOD

One hundred and twenty-seven first episode drug naïve patients with MDD and sixty healthy controls (HCs) were recruited for present study. The MATRICS Consensus Cognitive Battery was administered to measure the cognition. Plasma concentrations of nineteen cytokines were measured using high sensitivity multiplex bead-based assays.

RESULTS

Both female and male patients with MDD had significant cognitive impairment in verbal learning and visual learning and had higher levels of a range of cytokines than HCs (all p < 0.05). Female patients performed worse in trail making (F = 4.442, p = 0.018) and had higher concentration of interleukin (IL)-4 (F = 7.775, p = 0.006) than males. In female MDD, a significant positive association between category frequency and level of IL-4 was observed (B = 8.040, p = 0.031). However, this association was not present in male MDD or HCs (p > 0.05).

LIMITATION

Present study used a cross-sectional design.

CONCLUSION

Female MDD patients had worse trail making performance and higher level of IL-4 than males. The elevated IL-4 in female MDD was positively associated with category fluency, suggesting that IL-4 may be involved in the pathophysiology related to specific cognitive domain in female MDD patients.

Estrogen fluctuations during the menopausal transition are a risk factor for depressive disorders

Women are significantly more likely to develop depression than men. Fluctuations in the ovarian estrogen hormone levels are closely linked with women's well-being. This narrative review discusses the available knowledge on the role of estrogen in modulating brain function and the correlation between changes in estrogen levels and the development of depression. Equally discussed are the possible mechanisms underlying these effects, including the role of estrogen in modulating brain-derived neurotrophic factor activity, serotonin neurotransmission, as well as the induction of inflammatory response and changes in metabolic activity, are discussed.

Increased Clinical Pain Locations and Pain Sensitivity in Women After Breast Cancer Surgery: Influence of Aromatase Inhibitor Therapy

OBJECTIVES

Aromatase inhibitors (AIs), which potently inhibit estrogen biosynthesis, are a standard treatment for hormone sensitive early-stage breast cancer. AIs have been associated with substantial joint pain and muscle stiffness (aromatase inhibitor-associated musculoskeletal syndrome). However, the link between AIs and number of clinical pain locations and pain sensitivity are less well understood. The aim of this study was to compare longitudinal changes in clinical pain and quantitative pain sensitivity between women who did or did not receive AI therapy.

METHODS

Women with early-stage breast cancer were prospectively enrolled and assessed for clinical pain in surgical and nonsurgical body areas using the Brief Pain Inventory and Breast Cancer Pain Questionnaire, and for pain sensitivity using quantitative sensory testing preoperatively and at 1 year postoperatively. Pain outcomes between participants who did and did not begin adjuvant AI therapy were compared using Wilcoxon Signed-Ranks and generalized estimating equation linear regression analyses.

RESULTS

Clinical pain and pain sensitivity were comparable between AI (n=49) and no-AI (n=106) groups preoperatively. After adjusting for body mass index, AI therapy was associated with a greater increase in the number of painful nonsurgical body sites (significant time by treatment interaction, P =0.024). Pain location was most frequent in knees (28%), lower back (26%), and ankles/feet (17%). Quantitative sensory testing revealed a significant decrease in pain sensitivity (increased pressure pain threshold) in the no-AI group over time, but not in the AI group.

CONCLUSIONS

AI therapy was associated with increased diffuse joint-related pain and greater post-treatment pain sensitivity, potentially implicating central sensitization as a contributing pain mechanism of aromatase inhibitor-associated musculoskeletal syndrome worthy of future investigation.

Ovarian status modulates endocrine and neuroinflammatory responses to a murine mammary tumor

Patients with breast cancer have increased circulating inflammatory markers and mammary tumors increase neuroinflammation in rodent models. Menopausal status is not only important in the context of breast cancer as circulating estrogen influences tumor progression, but also because estrogen is anti-inflammatory and an essential modulator of endocrine function in the brain and body. Here, we manipulated "menopause" status (ovary-intact and ovariectomized) in an estrogen receptor (ER)+ mouse mammary tumor model to determine the extent to which ovarian status modulates: 1) tumor effects on estrogen concentrations and signaling in the brain, 2) tumor effects on estrogen-associated neurobiology and inflammation, and 3) the ability for tumor resection to resolve the effects of a tumor. We hypothesized that reduced circulating estradiol (E2) after an ovariectomy exacerbates tumor-induced peripheral and central inflammation. Notably, we observed ovarian-dependent modulation on tumor-induced peripheral outcomes, including E2-dependent processes and, to a lesser degree, circulating inflammatory markers. In the brain, ovariectomy exacerbated neuroinflammatory markers in select brain regions and modulated E2-related neurobiology due to a tumor and/or resection. Overall, our data suggest that ovarian status has moderate implications for tumor-induced alterations in neuroendocrinology and neuroinflammation and mild effects on peripheral inflammatory outcomes in this murine mammary tumor model.

Cerebrospinal fluid sex steroid hormones in bacterial meningitis

Unfavorable outcome in bacterial meningitis is related to excessive inflammation and higher inflammatory markers have been reported in female than in male patients. Sex steroid hormones have immunomodulatory properties and can be found in the cerebrospinal fluid (CSF); however, their actions have not been studied in bacterial meningitis. We investigated the association between CSF sex steroid hormone levels and inflammatory parameters, disease severity, and outcome in pneumococcal meningitis. We identified adults with culture-proven pneumococcal meningitis in a prospective cohort study (2006-2014). We measured estradiol and testosterone in CSF using liquid chromatography-tandem mass spectrometry and sex hormone-binding globulin (SHBG) using an enzyme-linked immunoassay. Hormone levels were compared according to outcome, which was graded using the Glasgow Outcome Scale (a score of 5 indicating favorable, 1-4 unfavorable outcome). Correlation analysis was used to measure the association between hormone levels and inflammatory cytokines, chemokines, and complement factors as well as severity of illness, as measured by the Glasgow Coma Scale and the Dutch Meningitis Risk Score. We included 60 patients: 20 men, 20 premenopausal (<50 years), and 20 postmenopausal (>50 years) women. Twenty-one (35%) patients had an unfavorable outcome and 11 (18%) died. Cases with an unfavorable outcome exhibited higher estradiol (median 14.0 vs 5.0 pmol/L, P = .04) and lower SHBG (0.40 vs 1.0 nmol/L, P = .03) levels compared with those with a favorable outcome. Estradiol was positively correlated with C-reactive protein (R = 0.42, P = .001), CSF protein (R = 0.33, P = .01), and proinflammatory cytokine levels. CSF concentrations of the sex steroid hormone estradiol were associated with outcome and CSF inflammation. Understanding the dose and time-dependent interaction between sex steroid hormones and the inflammatory response in bacterial meningitis represents an important and understudied topic.

Associations of the Lipidome with Ageing, Cognitive Decline and Exercise Behaviours

One of the most recognisable features of ageing is a decline in brain health and cognitive dysfunction, which is associated with perturbations to regular lipid homeostasis. Although ageing is the largest risk factor for several neurodegenerative diseases such as dementia, a loss in cognitive function is commonly observed in adults over the age of 65. Despite the prevalence of normal age-related cognitive decline, there is a lack of effective methods to improve the health of the ageing brain. In light of this, exercise has shown promise for positively influencing neurocognitive health and associated lipid profiles. This review summarises age-related changes in several lipid classes that are found in the brain, including fatty acyls, glycerolipids, phospholipids, sphingolipids and sterols, and explores the consequences of age-associated pathological cognitive decline on these lipid classes. Evidence of the positive effects of exercise on the affected lipid profiles are also discussed to highlight the potential for exercise to be used therapeutically to mitigate age-related changes to lipid metabolism and prevent cognitive decline in later life.

Autophagy Balances Neuroinflammation in Alzheimer's Disease

Autophagy is a highly evolutionary conserved process that degrades cytosolic macromolecules or damaged organelles (e.g., mitochondria), as well as intracellular pathogens for energy and survival. Dysfunction of autophagy has been associated with the pathologies of Alzheimer's disease (AD), including Aβ plaques and neurofibrillary tangles. Recently, the presence of sustained immune response in the brain has been considered a new core pathology in AD. Accumulating evidence suggests that autophagy activation may suppress inflammation response through degrading inflammasomes or pro-inflammatory cytokines and improving immune system function in both clinical trials and preclinical studies. This review provides an overview of updated information on autophagy and inflammation and their potential mediators in AD. In summary, we believe that understanding the relationship between autophagy and inflammation will provide insightful knowledge for future therapeutic implications in AD.

Women with lower systemic inflammation demonstrate steeper cognitive decline with age: Results from a large prospective, longitudinal sample

Background

Men and women experience large disparities in prevalence, detection, and clinical course of neurodegenerative diseases. Inflammation has been implicated in the pathogenesis of neurodegenerative diseases, yet there is a paucity of literature documenting sex differences in this phenomenon in prospective, longitudinal studies.

Methods

Participants were 4217 non-smoking individuals (62.2% female; aged 46–91 at enrollment) enrolled in the Health and Retirement Study who provided dried blood spots and completed a standardized assessment of cognitive function 3 times across 8 years. Inflammation was indexed using C-reactive protein (CRP).

Results

Higher CRP was associated with lower concurrent cognitive function, b = −0.13 (SE = 0.06), p < .05, but less decline in cognitive function over time, b = 0.02 (SE = 0.01), p < .05. Sex moderated the association between CRP and decline in total cognitive function, b = 0.02 (SE = 0.01), p < .05, such that the steepest declines in cognitive function were observed among women with the lowest CRP concentrations.

Conclusions

Women with lower systemic inflammation as measured by CRP may be at risk of going undetected for neurodegenerative disease, especially given their overall higher cognitive scores. This may perpetuate sex-related disparities in prevention and clinical course. Attention to the underlying biological mechanisms explaining the link between lower CRP and risk for cognitive decline for women and its potential clinical implications are needed.

•

Sex differences in links between inflammation and cognitive function are under-explored.

•

Higher CRP was associated with lower concurrent cognitive function, only in men.

•

Women with lower CRP showed the steepest declines in cognitive functioning.

Commercial Hormone Replacement Therapy Jeopardized Proinflammatory Factors in Experimental Rat Models

BACKGROUND: Hormonal contraceptive therapy is considered the easiest and most convenient contraceptive method. Commercially, available contraceptive combination differs in their composition and concentration of combined constituents. These variations make some of these products preferred over others by consumers based on their side effects profile. AIM: The objective of the current research was to ascertain the proinflammatory influences of commercially available products. METHODS: To do so, five groups of rats (ten rats in each group) were exposed to Microgynon, Depo-Provera, marvel on, and Yasmin compared to the control non-treated group. We measured proinflammatory markers including d-dimer, TNF-α (tumor necrosis factor-alpha), IL (interleukin)-6, IL (interleukin)-1B, and c-reactive protein. RESULTS: The results confirmed that Yasmin has induced the most deleterious effects on proinflammatory markers indicated by significant elevation of IL1B. CONCLUSION: Hormone replacement therapy should be critically indicated and precautions raised inpatient with subclinical diseases, especially cardiovascular ones.

Association of the Dietary Inflammatory Index with Depressive Symptoms among Pre- and Post-Menopausal Women: Findings from the National Health and Nutrition Examination Survey (NHANES) 2005-2010

During their lifetime, 20% of US women experience depression. Studies have indicated that a high Dietary Inflammatory Index (DII) score is associated with high C-reactive protein (CRP) levels and depression. No previous study has compared the association of the DII with different measures of depression (e.g., somatic, cognitive) among pre- and post-menopausal women. We used data from 2512 pre-menopausal and 2392 post-menopausal women from the National Health and Nutrition Examination Survey (NHANES) 2005−2010 database. We ran linear and logistic regression models to compare the association of the DII with survey-measured depression among pre- and post-menopausal women. We further assessed the mediation effect of CRP on the association of the DII and depression, using structural equation modeling. The odds of experiencing depression among pre-menopausal women was higher for all DII quartiles compared to the reference group (i.e., DII Q1), with an odds ratio (OR) of 3.2, 5.0, and 6.3 for Q2, Q3, and Q4, respectively (p < 0.05). Among post-menopausal women, only Q4 had 110% higher odds of experiencing depression compared to Q1 (p = 0.027). No mediation effect of CRP was found between DII and any of our depression outcome measures. Our findings suggest that lifestyle habits, such as diet, may have a stronger influence on mental health among pre-menopausal women than post-menopausal women.

Cerebral autoregulation across the menstrual cycle in eumenorrheic women

There is emerging evidence that ovarian hormones play a significant role in the lower stroke incidence observed in pre‐menopausal women compared with men. However, the role of ovarian hormones in cerebrovascular regulation remains to be elucidated. We examined the blood pressure‐cerebral blood flow relationship (cerebral autoregulation) across the menstrual cycle in eumenorrheic women (n = 12; mean ± SD: age, 31 ± 7 years). Participants completed sit‐to‐stand and Valsalva maneuvers (VM, mouth pressure of 40 mmHg for 15 s) during the early follicular (EF), late follicular (LF), and mid‐luteal (ML) menstrual cycle phases, confirmed by serum measurement of progesterone and 17β‐estradiol. Middle cerebral artery blood velocity (MCAv), arterial blood pressure and partial pressure of end‐tidal carbon dioxide were measured. Cerebral autoregulation was assessed by transfer function analysis during spontaneous blood pressure oscillations, rate of regulation (RoR) during sit‐to‐stand maneuvers, and Tieck’s autoregulatory index during VM phases II and IV (AI‐II and AI‐IV, respectively). Resting mean MCAv (MCAv_mean), blood pressure, and cerebral autoregulation were unchanged across the menstrual cycle (all p > 0.12). RoR tended to be different (EF, 0.25 ± 0.06; LF; 0.19 ± 0.04; ML, 0.18 ± 0.12 sec⁻¹; p = 0.07) and demonstrated a negative relationship with 17β‐estradiol (R² = 0.26, p = 0.02). No changes in AI‐II (EF, 1.95 ± 1.20; LF, 1.67 ± 0.77 and ML, 1.20 ± 0.55) or AI‐IV (EF, 1.35 ± 0.21; LF, 1.27 ± 0.26 and ML, 1.20 ± 0.2) were observed (p = 0.25 and 0.37, respectively). Although, a significant interaction effect (p = 0.02) was observed for the VM MCAv_mean response. These data indicate that the menstrual cycle has limited impact on cerebrovascular autoregulation, but individual differences should be considered.

Sex Differences in Poststroke Inflammation: a Focus on Microglia Across the Lifespan

Stroke is one of the leading causes of death worldwide and currently only few therapeutic options are available. Stroke is a sexually dimorphic disease contributing to the difficulty in finding efficient treatments. Poststroke neuroinflammation is geared largely by brain microglia and infiltrating peripheral immune cells and largely contributes to sex differences in the outcome of stroke. Microglia, since very early in the development, are sexually divergent, imprinting specific sex-related features. The diversity in terms of microglial density, morphology, and transcriptomic and proteomic profiles between sexes remains in the adulthood and is likely to contribute to the observed sex-differences on the postischemic inflammation. The impact of sexual hormones is fundamental: changes in terms of risk and severity have been observed for females before and after menopause underlining the importance of altered circulating sexual hormones. Moreover, aging is a driving force for changes that interact with sex, shifting the inflammatory response in a sex-dependent manner. This review summarizes the present literature on sex differences in stroke-induced inflammatory responses, with the focus on different microglial responses along lifespan.

Total phenolic, flavonoid contents, and biological activities of stem extracts of Astragalus spinosus (Forssk.) Muschl. grown in Northern Border Province, Saudi Arabia

Background and objective

Genus Astragalus belongs to the family Fabaceae and is one among the largest genera consisting of around 3000 species. The plants have been used traditionally in treatment of various ailments in folklore. The study was planned to assess the analgesic and inflammatory activity of Astragulus spinosus (Forssk.) Muschl extract of the stem.

Materials and methods

Course powder of stems of Astragulus spinosus was extracted using chloroform and methanol as solvents. Folin ciocalteu method was employed for determination of the phenolic acid content. Aluminum chloride colorimetric procedure was followed for estimating the flavonoid content. Both chloroform and methanolic extracts at 250 and 500 mg/kg, were tested for the analgesic activity, however, only methanolic extract was selected for anti-inflammatory property based on the results of analgesic activity. The analgesic effect was executed on male rats by the hot plate model. The anti-inflammatory effect was studied in the carrageenan rat paw edema model. The experimental information was interpreted statistically using one-way ANOVA and p < 0.05 was used to express importance of the results.

Results

The total phenolics of the methanol extract was 420 µg and that of chloroform extract was 265 µgwhile total flavonoid content in terms of quercetin was found to be 68 µg and 17.5 µg for methanol and chloroform extract respectively. Only methanolic extract exhibited significant (p < 0.001) analgesic activity by elevating the pain threshold starting from 15 min. The methanolic extract inhibited (p < 0.001) the edema in carrageenan induced model. The performance of higher dose (500 mg/kg) was better with reference to lower dose (250 mg/kg).

Conclusion

Outcome of the results show that the methanolic stem extracts exhibited significant analgesic and anti-inflammatory-like activity with reference to chloroform extract. Credit of which is given to flavonoids and phenolic content present in the methanolic extract. However, more research is suggested to establish the safety and effectiveness of the herbal drug to manage diseased states including pain and inflammation.

A novel targeted approach to delineate a role for estrogen receptor-β in ameliorating murine mammary tumor-associated neuroinflammation

PURPOSE

Circulating estrogens in breast cancer patients and survivors are often extremely low due to menopause and estrogen-reducing cancer treatments. Simultaneously, circulating inflammatory markers, and inflammatory proteins in brains of rodent tumor models, can be elevated and correlate with debilitating neurological and psychological comorbidities. Because estrogen has anti-inflammatory properties in the brain, we hypothesized that mammary tumor-induced neuroinflammation is driven, in part, by reduced brain estrogen signaling.

METHODS

An ovariectomized mouse model of postmenopausal breast cancer utilizing the ERα-positive 67NR mammary tumor cell line was used for these experiments. A novel, orally bioavailable, and brain penetrant ERβ agonist was administered daily via oral gavage. Following treatment, estrogen-responsive genes were measured in brain regions. Central and circulating inflammatory markers were measured via RT-qPCR and a multiplex cytokine array, respectively.

RESULTS

We present novel findings that peripheral mammary tumors alter estrogen signaling genes including receptors and aromatase in the hypothalamus, hippocampus, and frontal cortex. Mammary tumors induced peripheral and central inflammation, however, pharmacological ERβ activation was not sufficient to reduce this inflammation.

CONCLUSIONS

Data presented here suggest that compensating for low circulating estrogen with ERβ brain activation is not sufficient to attenuate mammary tumor-induced neuroinflammation, and is therefore not a likely candidate for the treatment of behavioral symptoms in patients. The novel finding that mammary tumors alter estrogen signaling-related genes is a clinically relevant advancement to the understanding of how peripheral tumor biology modulates neurobiology. This is necessary to predict and prevent behavioral comorbidities (e.g., cognitive impairment) prevalent in cancer patients and survivors.

Rapid Identification of 44 Steroids in Human Urine Samples using HPLCESI- QTOF-MS

Objective:

Detailed analysis of un-processed and un-derivatized free and conjugated urinary steroids is useful to avoid miscalculations and to diagnose sports doping and adrenal problems, including abnormal steroidogenesis, congenital deficiency of related enzymes, cancer, and other disease conditions. Hence, the present study was conducted to develop a soft ionization method to identify the maximum number of urinary steroids using ultra-performance liquid chromatography coupled with quadrupole time of flight mass spectrometer (HPLC–Q-TOF-MS).

Material and Methods:

HPLC–Q-TOF-MS was carried out for the qualitative detection of steroids and their conjugates in urine samples. The method provides high sensitivity and fast analysis of steroids and their glucuronides without hydrolysis or sample preparation or extraction of steroids.

Results:

Using the method, 44 steroids belonging to C-18, C-19, and C-21 classes and their conjugates were resolved and identified using positive and negative modes of ionizations by their characteristic ionization and collision energy induced dissociation behaviors.

Conclusion:

The method is time-saving and good to compare samples from different peoples with control or healthy ones as it does not require any kind of pre-treatment or sample processing. It provides a complete picture of steroids metabolism and catabolism. It can be good for doping control or to explore the effects of other drugs. However, in qualitative analysis, one may miss the significant information unless direct methods of steroids analysis to be employed.

Delayed Minocycline Treatment Ameliorates Hydrocephalus Development and Choroid Plexus Inflammation in Spontaneously Hypertensive Rats

Hydrocephalus is a complicated disorder that affects both adult and pediatric populations. The mechanism of hydrocephalus development, especially when there is no mass lesion present causing an obstructive, is poorly understood. Prior studies have demonstrated that spontaneously hypertensive rats (SHRs) develop hydrocephalus by week 7, which was attenuated with minocycline. The aim of this study was to determine sex differences in hydrocephalus development and to examine the effect of minocycline administration after hydrocephalus onset. Male and female Wistar-Kyoto rats (WKYs) and SHRs underwent magnetic resonance imaging at weeks 7 and 9 to determine ventricular volume. Choroid plexus epiplexus cell activation, cognitive deficits, white matter atrophy, and hippocampal neuronal loss were examined at week 9. In the second phase of the experiment, male SHRs (7 weeks old) were treated with either saline or minocycline (20 mg/kg) for 14 days, and similar radiologic, histologic, and behavior tests were performed. Hydrocephalus was present at week 7 and increased at week 9 in both male and female SHRs, which was associated with greater epiplexus cell activation than WKYs. Male SHRs had greater ventricular volume and epiplexus cell activation compared to female SHRs. Minocycline administration improved cognitive function, white matter atrophy, and hippocampal neuronal cell loss. In conclusion, while both male and female SHRs developed hydrocephalus and epiplexus cell activation by week 9, it was more severe in males. Delayed minocycline treatment alleviated hydrocephalus, epiplexus macrophage activation, brain pathology, and cognitive impairment in male SHRs.

Inflammatory Potential of Diet and Odds of Lung Cancer: A Case-Control Study

Lung cancer is one of the common types of malignant disorders and the most prevalent cause of cancer mortality worldwide. Few studies have examined the association of dietary inflammatory index (DII) with lung cancer and findings from these studies are conflicting. Moreover, no study has examined this association in the Middle East. Therefore, the current case-control study was conducted to examine the association between DII and lung cancer among Iranian adults. We recruited 140 pathologically confirmed cases of lung cancer and 140 healthy controls who were matched with cases in terms of age. Dietary intakes were assessed using a 142-item Willett-format dish-based semi-quantitative food frequency questionnaire. DII scores were calculated using the method developed by Shivappa et al. Overall, we found a significant positive association between DII and lung cancer so that after controlling for potential confounders, individuals in the highest tertile of DII scores had 2.03 times more odds of lung cancer compared to those in the lowest tertile (OR: 2.01; 95% CI: 1.02-4.01). This significant positive association was also seen in men, but not in women. In conclusion, adherence to a pro-inflammatory diet was associated with increased odds of lung cancer in adults, particularly in male adults.

Effects of estradiol supplementation on the brain transcriptome of old rhesus macaques maintained on an obesogenic diet

Obesity, the cessation of ovarian steroids with menopause, and age are risk factors for mood disorders, dementia, and Alzheimer's disease (AD). However, immediate hormone therapy (HT) after menopause may have beneficial effects in different brain regions involved in memory and cognition. To more closely replicate the age, endocrine, and metabolic environment of obese postmenopausal women, either on or off HT, middle-aged female rhesus macaques were ovariectomized/hysterectomized (OvH) and maintained on a high-fat, high-sugar, obesogenic Western-style diet (WSD) for 30 months; half of the animals received HT immediately after OvH and half served as placebo controls. RNAseq of the occipital (OC) and prefrontal cortex (PFC), hippocampus (HIP), and amygdala (AMG) identified 293, 379, 505, and 4993 differentially expressed genes (DEGs), respectively. Pathway enrichment analysis identified an activation of neuroinflammation in OC and HIP, but an inhibition in the AMG with HT. Synaptogenesis, circadian rhythm, mitochondrial dysfunction, mTOR, glutamate, serotonin, GABA, dopamine, epinephrine/norepinephrine, glucocorticoid receptor signaling, neuronal NOS, and amyloid processing were exclusively enriched in AMG. As compared to the placebo control group, most of these signaling pathways are downregulated after HT, suggesting a protective effect of HT in OvH females under a WSD. Overall, our results suggest that a chronic obesogenic diet may induce a wide range of alterations in multiple signaling pathways that are linked to age-associated brain pathology and dementia. In these individuals, HT seems to have a protective effect against neuroinflammation, amyloid beta depositions, and tau tangle formation.

Kidney function, brain morphology and cognition in the elderly: sex differences in the Austrian Stroke Prevention Study

Impaired kidney function is associated with structural brain changes and cognitive dysfunction. In the aging kidney, hemodynamic and structural alterations reduce the glomerular filtration rate (eGFR). Little is known about differences between men and women regarding decline of kidney function and brain damage.

In this community-based study, we assessed associations between the eGFR, focal and diffuse brain abnormalities and cognitive functions. Sex-specific effects were analyzed by interaction terms eGFR x sex on brain structure and cognition. Interactive effects were assessed using mixed-models –stratified by sex.

Overall, 196 women and 129 men (median age 68 years and mean eGFR 73.8±14.9 ml/min/1.73m²) were included. Significant associations existed between eGFR and cortical volume (β: 1.53E-04; SE: 6.72E-05; p=0.023 for neocortex). Sex exerted a significant interactive effect. Only in men, eGFR related to cortical volumes of all lobes and of deep gray matter structures (p= 0.001 for total gray matter, p=0.0004 for neocortex). In the whole group eGFR was not associated with cognition, but men with lower eGFR performed worse on tests for executive function, which, after FDR correction, was not significant.

We conclude, that in community-dwelling middle-aged and elderly individuals, reduced eGFR relates to brain volume loss in men but not in women.

Gender-based differences in neuroprotective effects of hydrogen gas against intracerebral hemorrhage-induced depression

BACKGROUND

Post-stroke depression (PSD) severely affects recovery in patients with intracerebral hemorrhage (ICH). Although hydrogen gas (H₂) exerts excellent neuroprotective effects in patients with ICH, there are sex-based differences in H₂ efficacy in several diseases. Herein, we determined whether estrogen increases susceptibility to the neuroprotective effects of H₂ in males with ICH-induced depression.

METHODS

A rodent model of ICH in the basal ganglia was established using autologous blood injection (30 μL). Mice were treated with 2.9% H₂ for 2 h daily for 3 days post-ICH. Estrogen (1 mg/kg) was administered by subcutaneous injection daily for 3 days to male mice post-ICH. Thirty days post-ICH, PSD was evaluated by sucrose preference, forced swimming, and 3-chamber social tests. Following the completion of behavioral tests, levels of superoxide dismutase (SOD) and reactive oxygen species (ROS), astrocytic activation, phosphorylated (p)-NF-κB-positive astrocytes, p-NF-κB, p-IKKβ, IL-1β, and IL-6 expression were determined.

RESULTS

Compared with female mice, H₂ administration post-ICH exhibited fewer neuroprotective effects, including decreased sucrose consumption and time spent sniffing a novel mouse, increased immobility time, downregulated total SOD content, upregulated ROS content and p-NF-κB levels, and elevated astrocyte branches, whereas estrogen enhanced the neuroprotective effects of H₂ in male mice. A reduced number of p-NF-κB-positive astrocytes, downregulated expression of p-NF-κB, p-IKKβ, IL-1β, and IL-6 in the amygdala were demonstrated in ICH-males treated with estrogen plus H₂.

CONCLUSIONS

Estrogen was responsible for increased H₂ sensitivity in male mice with ICH. The underlying mechanism may be associated with the suppression of NF-κB signaling in astrocytes.

The Use of ERE-Luc Reporter Mice to Monitor Estrogen Receptor Transcriptional Activity in a Spatio-Temporal Dimension

In spite of the fact that women spend 1/3 of their lives in postmenopause, the search for appropriate therapies able to counteract the derangements associated with the menopause still represents a sort of sought after the "Holy Grail."Nowadays, the combination of estrogens and selective estrogen receptor modulators (SERMs), a class of compounds with a mixed agonist/antagonistic activity on the estrogen receptor (ER) in various tissues, represents the most promising approach to improve postmenopausal women's health, by preserving the benefits while avoiding the side effects of estrogen-based therapy.Given their complex mechanisms of action, the evaluation of SERM activity in combination with conjugated estrogens (CE) requires a multifactorial analysis that takes into account the multifaceted and dynamic effects of these compounds in target tissues, even in relation to the physiological/pathological status.To accomplish such a goal, we took advantage of the ERE-Luc model, a reporter mouse that allows the monitoring of ER transcriptional activity in a spatio-temporal dimension. Cluster analyses performed on in vivo/ex vivo bioluminescence (BLI) data and ex vivo luciferase activity enabled to sustain the combination of CE plus bazedoxifene (TSEC, tissue-selective estrogen complex) as a valuable option for the pharmacological treatment of the postmenopause.

Lipid-lowering drug targets and Parkinson's disease: A sex-specific Mendelian randomization study

Parkinson's disease (PD) affects millions of individuals worldwide, and it is the second most common late-onset neurodegenerative disorder. There is no cure and current treatments only alleviate symptoms. Modifiable risk factors have been explored as possible options for decreasing risk or developing drug targets to treat PD, including low-density lipoprotein cholesterol (LDL-C). There is evidence of sex differences for cholesterol levels as well as for PD risk. Genetic datasets of increasing size are permitting association analyses with increased power, including sex-stratified analyses. These association results empower Mendelian randomization (MR) studies, which, given certain assumptions, test whether there is a causal relationship between the risk factor and the outcome using genetic instruments. Sex-specific causal inference approaches could highlight sex-specific effects that may otherwise be masked by sex-agnostic approaches. We conducted a sex-specific two-sample cis-MR analysis based on genetic variants in LDL-C target encoding genes to assess the impact of lipid-lowering drug targets on PD risk. To complement the cis-MR analysis, we also conducted a sex-specific standard MR analysis (using genome-wide independent variants). We did not find evidence of a causal relationship between LDL-C levels and PD risk in females [OR (95% CI) = 1.01 (0.60, 1.69), IVW random-effects] or males [OR (95% CI) = 0.93 (0.55, 1.56)]. The sex-specific standard MR analysis also supported this conclusion. We encourage future work assessing sex-specific effects using causal inference techniques to better understand factors that may contribute to complex disease risk differently between the sexes.

β-Amyloid Formation, Memory, and Learning Decline Following Long-term Ovariectomy and Its Inhibition by Systemic Administration of Apigenin and β-Estradiol

Introduction:

The increasing cases of Alzheimer Disease (AD) has caused numerous problems. The risk of developing AD increases in menopausal women, too. Apigenin and β-estradiol are effective antioxidant and neuroprotective agents. We conducted the present study to explore their combined effects on β-amyloid plaque formation, memory, and learning in ovariectomized rats.

Methods:

Forty-two Wistar rats were randomly assigned into 6 groups: 1) ovariectomized (OVX), 2) OVX + apigenin, 3) OVX + β-estradiol, 4) OVX + apigenin + β-estradiol, 5 &6) vehicle shams for E2 and API, and 7) surgical sham. Treatment was done with apigenin and β-estradiol. Then, we studied the formation of β-amyloid plaques, neuronal density in the hippocampus area, apoptosis, memory, and learning.

Results:

Findings showed the significant formation of β-amyloid plaques in the hippocampus of OVX animals and their memory impairment. Apigenin and β-estradiol significantly reduced the number of β-amyloid plaques, as well as the symptoms of memory impairment and learning, and decreased the expression of caspase-3 in treated animals.

Conclusion:

Accordingly, β-estradiol and apigenin could have more potent therapeutic effects on AD.

Effect of sex and gonadectomy on brain MPTP toxicity and response to dutasteride treatment in mice

The main neuropathological feature of Parkinson's disease (PD) is degeneration of dopamine (DA) neurons in the substantia nigra (SN); PD prevalence is higher in men, suggesting a role of sex hormones in neuroprotection. This study sought the effects of sex hormones in the brain in a mouse model of PD and modulation of steroid metabolism/synthesis with the 5α-reductase inhibitor dutasteride shown to protect 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) male mice. Male and female mice were gonadectomized (GDX) or SHAM operated. They were treated with vehicle or dutasteride (5 mg/kg) for 10 days and administered a low dose of MPTP (5.5 mg/kg) or saline on the 5th day to model early PD; brains were collected thereafter. Striatal measures of the active metabolite 1-methyl-4-phenylpyridinium (MPP+) contents showed no difference supporting an effect of the experimental conditions investigated. In SHAM MPTP male mice loss of striatal DA and metabolites, DA transporter (DAT) and vesicular monoamine transporter 2 (VMAT2) specific binding in the striatum and SN was prevented by dutasteride treatment; these changes were inversely correlated with glial fibrillary acidic protein (GFAP, an astrogliosis marker) levels. In SHAM female mice MPTP treatment had little or no effect on striatal and SN DA markers and GFAP levels whereas GDX male and female mice showed a similar loss of striatal DA markers and increase of GFAP. No effect of dutasteride treatment was observed in GDX male and female mice. In conclusion, sex differences in mice MPTP toxicity and response to dutasteride were observed that were lost upon gonadectomy implicating neuroinflammation.

Depression and obesity among females, are sex specificities considered?

This study aimed to systematically review the relationship of obesity-depression in the female sex. We carried out a systematic search (PubMed, MEDLINE, Embase) to quantify the articles (controlled trials and randomized controlled trials) regarding obesity and depression on a female population or a mixed sample. Successively, we established whether the sex specificities were studied by the authors and if they reported on collecting data regarding factors that may contribute to the evolution of obesity and depression and that could be responsible for the greater susceptibility of females to those conditions. After applying the inclusion and exclusion criteria, we found a total of 20 articles with a female sample and 54 articles with a mixed sample. More than half of all articles (51.35%, n = 38) evaluated the relationship between depression and obesity, but only 20 (27.03%) evaluated this relationship among females; still, 80% of those (n = 16) presented supporting results. However, few articles considered confounding factors related to female hormones (12.16%, n = 9) and none of the articles focused on factors responsible for the binomial obesity-depression in the female sex. The resulting articles also supported that depression (and related impairments) influencing obesity (and related impairments) is a two-way road. This systematic review supports the concurrency of obesity-depression in females but also shows how sex specificities are ultimately under-investigated. Female sex specificity is not being actively considered when studying the binomial obesity-depression, even within a female sample. Future studies should focus on trying to understand how the female sex and normal hormonal variations influence these conditions.

Brain-derived estrogen and neural function

Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E₂) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E₂ (BDE₂). Much of what we know regarding the functional roles of BDE₂ has come from studies using specific inhibitors of the E₂ synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E₂ (NDE₂) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E₂ (ADE₂) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.