Ovariectomy, a model of menopause in rodents, causes a premature aging of the nervous and immune systems

Treatment of menopausal skin - A narrative review of existing treatments, controversies, and future perspectives

Menopause is a state of estrogen deficiency that affects numerous estrogen-dependent tissues in the female body. Skin is one of the most affected organs. Many consider menopausal skin changes to be merely an aesthetic problem; however, they can significantly affect women's quality of life. Currently, there are no approved effective treatments to prevent or alleviate skin changes associated with estrogen deficiency. Standard systemic hormone replacement therapy used to treat menopausal symptoms may be effective to some degree for skin treatment. In addition, compounded bioidentical hormone replacement therapy, selective estrogen receptor modulators, and phytoestrogens could also be used for skin treatment, although this is only hypothetical due to lack of data. Many questions therefore remain unanswered. On the other hand, topical, low-dose estrogen that would act only on the skin without systemic effects could be a possible option, as could be skin-only acting topical phytoestrogens. Such topical products without systemic effects could play a role in the treatment of menopausal skin. However, they are not currently approved because there is insufficient data on their safety and efficacy. A healthy lifestyle could have a positive effect on the menopausal skin. In this review, we provide an overview of the characteristics of menopausal skin, an outlook on the future treatment of menopausal skin with estrogens and other approaches, and the associated controversies and speculations. Overall, the importance of menopausal skin changes should not be neglected, and high-quality research is needed to gain new insights into the treatment of menopausal skin.

Hepatic Oxi-Inflammation and Neophobia as Potential Liver-Brain Axis Targets for Alzheimer's Disease and Aging, with Strong Sensitivity to Sex, Isolation, and Obesity

Research on Alzheimer's disease (AD) has classically focused on alterations that occur in the brain and their intra- and extracellular neuropathological hallmarks. However, the oxi-inflammation hypothesis of aging may also play a role in neuroimmunoendocrine dysregulation and the disease's pathophysiology, where the liver emerges as a target organ due to its implication in regulating metabolism and supporting the immune system. In the present work, we demonstrate organ (hepatomegaly), tissue (histopathological amyloidosis), and cellular oxidative stress (decreased glutathione peroxidase and increased glutathione reductase enzymatic activities) and inflammation (increased IL-6 and TNF𝛼) as hallmarks of hepatic dysfunction in 16-month-old male and female 3xTg-AD mice at advanced stages of the disease, and as compared to age- and sex-matched non-transgenic (NTg) counterparts. Moreover, liver-brain axis alterations were found through behavioral (increased neophobia) and HPA axis correlations that were enhanced under forced isolation. In all cases, sex (male) and isolation (naturalistic and forced) were determinants of worse hepatomegaly, oxidative stress, and inflammation progression. In addition, obesity in old male NTg mice was translated into a worse steatosis grade. Further research is underway determine whether these alterations could correlate with a worse disease prognosis and to establish potential integrative system targets for AD research.

In Response to a Punctual Stress Male and Female Tyrosine Hydroxylase Haploinsufficient Mice Show a Deteriorated Behavior, Immunity, and Redox State

An inadequate stress response is associated with impaired neuroimmunoendocrine communication, increasing morbidity and mortality. Since catecholamines (CA) constitute one of the acute stress response pathways, female mice with an haploinsufficiency of the tyrosine hydroxylase gene (TH-HZ), the main limiting enzyme in CA synthesis, show low CA amounts, exhibiting an impairment of homeostatic systems. The aim of this study was to investigate the effect of a punctual stress in TH-HZ mice, determining the differences with wild-type (WT) mice and those due to sex by restraint with a clamp for 10 min. After restraint, a behavioral battery was performed, and several immune functions, redox state parameters, and CA amounts were evaluated in peritoneal leukocytes. Results show that this punctual stress impaired WT behavior and improved female WT immunity and oxidative stress, whereas in TH-HZ mice, all parameters were impaired. In addition, different responses to stress due to sex were observed, with males having a worse response. In conclusion, this study confirms that a correct CA synthesis is necessary to deal with stress, and that when a positive stress (eustress) occurs, individuals may improve their immune function and oxidative state. Furthermore, it shows that the response to the same stressor is different according to sex.

Positive effects of pulsed electromagnetic fields on behavior, immune function, and oxidative and inflammatory state in old mice

The establishment of chronic oxidative and inflammatory stress with aging leads to the deterioration of the nervous and immune systems and, consequently, to the loss of health. The aim of this work was to study the effect of exposure to low-frequency pulsed electromagnetic fields (PEMFs) produced by the NEURALTER® system (15 min/day for 4 weeks) in the behavior, immune functions, and oxidative and inflammatory state of old mice. Female old CD1 mice were divided into three groups: control group, handling control group and Neuralter group. Then, behavioral tests were performed, and peritoneal leukocytes were extracted to analyze function, oxidative and inflammatory parameters. In peritoneal leukocytes from old mice, the effects in vitro of 15 min with NEURALTER® were studied on function and oxidative parameters. The results show that after this type of treatment, old mice had greater coordination and locomotion, better immune function, and an oxidative-inflammatory state. Similarly, the immune function and oxidative state of leukocytes showed an improvement when these cells were exposed directly to the NEURALTER® system. In conclusion, the exposure to low-frequency PEMFs produced by the NEURALTER® system has beneficial effects on health in aging. In addition, this effect is direct, at least in part, on immune cells.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Skin-to-Skin Contact: Crucial for Improving Behavior, Immunity, and Redox State after Short Cohabitation of Chronologically Old Mice and Prematurely Aging Mice with Adult Mice

(1) Background: Aging is characterized by a deterioration of the homeostatic systems, namely the nervous and immune systems. The rate of aging can be modified by lifestyle factors such as social interactions. Recently, improvements in behavior, immune function, and oxidative state were observed in adult prematurely aging mice (PAM) and chronologically old mice after cohabitation with exceptional non-PAM (E-NPAM) and adult mice, respectively, for 2 months. However, the cause of this positive effect is not known. The objective of the present work was to study whether skin-to-skin contact promotes these improvements both in chronologically old mice and in adult PAM. (2) Methods: Old and adult CD1 female mice were used as well as adult PAM and E-NPAM. After cohabitation for 15 min/day for 2 months (two old mice or PAM with five adult mice or E-NPAM, respectively, with both non- and skin-to-skin contact), several behavioral tests were performed and functions and oxidative stress parameters in peritoneal leukocytes were analyzed. (3) Results: This social interaction improved behavioral responses, immune functions, redox state, and longevity, but only if the animals had skin-to-skin contact. (4) Conclusions: Physical contact seems to be crucial to experiencing the positive effects of social interaction.

Paclitaxel Chemotherapy Elicits Widespread Brain Anisotropy Changes in a Comprehensive Mouse Model of Breast Cancer Survivorship: Evidence From In Vivo Diffusion Weighted Imaging

Breast cancer is one of the most common diseases in the United States with 1 in 8 women developing the disease in her lifetime. Women who develop breast cancer are often post-menopausal and undergo a complex sequence of treatments including surgery, chemotherapy, and aromatase inhibitor therapy. Both independently and through potential interactions, these factors and treatments are associated with behavioral comorbidities reported in patients (e.g., fatigue), although the underlying neurobiological mechanisms are poorly understood. Currently, brain imaging is the most feasible way to assess neurobiology in patients. Indeed, breast cancer patients display alterations in white matter connections and chemotherapy is associated with decreased white and gray matter in the corpus callosum and cortex as well as decreased hippocampal volume. However, imaging in breast cancer rodent models is lacking, impeding translation of the mechanistic neurobiological findings made possible through modeling. Furthermore, current rodent models of breast cancer often lack the complexity of typical multimodal breast cancer treatments, thereby limiting translational value. The present study aimed to develop a comprehensive model of post-menopausal breast cancer survival using immunocompetent ovariectomized mice, including an orthotopic syngeneic tumor, surgical tumor removal, chemotherapy, and aromatase inhibitor therapy. Using this model, we systematically investigated the cumulative effects of chemotherapy and hormone replacement therapy on neurostructure and behavior using diffusion weighted imaging, open field test, and spontaneous alternation test. Our previous findings, in a simplified chemotherapy-only model, indicate that this regimen of chemotherapy causes circulating and central inflammation concurrent with reduced locomotor activity. The current study, in the more comprehensive model, has recapitulated the peripheral inflammation coincident with reduced locomotor activity as well as demonstrated that chemotherapy also drives widespread changes in brain anisotropy. Validating the clinical relevance of this comprehensive rodent breast cancer model will allow for additional neurobiological investigations of the interactions among various cancer components associated with behavioral comorbidities, as well as the relationship between these mechanisms and neurostructural imaging changes that can be measured in cancer patients.

Current Animal Model Systems for Ovarian Aging Research

Ovarian aging leads to menopause, loss of fertility and other disorders in multiple organs, which brings great distress to women. For ethical reasons, it is impossible to use humans as direct study subjects for aging research. Therefore, biomedical researchers have employed different non-human organisms to study ovarian aging, including worms, fruit flies, fishes, amphibians, birds, mice, rats, cavies, rabbits, pigs, sheep, cows, horses, monkeys, and apes. Because each of these model organisms has its own features, multiple factors, such as size, anatomical structure, cost, ease of operation, fertility, generation time, lifespan, and gene heredity, should be carefully considered when selecting a model system to study ovarian aging. An appropriate model organism would help researchers explore the risk factors and elucidate molecular mechanisms underlying declined ovarian functions, which might be conducive to preventing or delaying the ovarian aging process. This article will offer an overview on several currently available and commonly used model organisms for ovarian aging research by comparing their pros and cons. In doing so, we hope to provide useful information for ovarian aging researchers.

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.

A short social interaction between adult and old mice improves the homeostatic systems and increases healthy longevity

The aging process can be influenced by environmental factors, such as the social environment. The continuous cohabitation of the chronologically old mice with adult animals improves them at the behavioral level, immune function, oxidative stress and longevity, but causes a deterioration of these parameters in adults. Therefore, the objective of the study was to study whether the coexistence for only 15 min a day of old mice with adult mice, can produce that improvement and greater longevity in old animals without causing deterioration in adults. For that, old and adult CD1 female mice, after two months of that social interaction, were submitted to a behavioral battery and then peritoneal leukocytes were collected to assess several immune functions, oxidative and inflammatory stress parameters as well as catecholamine concentrations. When the adult mice reached old age, the same parameters were again analyzed. The life span of each animal was also recorded. Plasmatic concentration of oxytocin was also studied. The results showed that old mice presented better behavioral capacity, immunity and oxi-inflammatory state after this social interaction with adult animals, and consequently an extended life span. Adult mice, in general, did not show any changes after social interaction with old animals, but when they achieved old age, improvements of some parameters and of longevity were observed in comparison with animals that never had a that social interaction. In conclusion, a short social interaction between old and adult individuals can be an excellent strategy for improving in both the health state and longevity.

Daily ingestion of Akkermansia mucciniphila for one month promotes healthy aging and increases lifespan in old female mice

The ingestion of certain probiotics has been suggested as a promising nutritional strategy to improve aging. The objective of this work was to evaluate the effects of the daily intake, for a month, of a new probiotic Akkermansia muciniphila (AKK) (2 × 10⁸ cfu/100µL PBS) on behavior, as well as function and redox state of immune cells of old female ICR-CD1 mice (OA group). For this, several behavioral tests were performed, and function and oxidative-inflammatory stress parameters of peritoneal leukocytes were analyzed in OA group, in a group of the same age that did not take AKK (old control, OC group) and in another adult control (AC) group. The results showed, in OA group, a significant improvement of several behavioral responses (coordination, balance, neuromuscular vigor, exploratory ability and anxiety like-behaviors), as well as in immune functions (chemotaxis, phagocytosis, NK activity and lymphoproliferation) and in oxidative stress parameters (glutathione peroxidase and reductase activities, oxidized glutathione and lipid oxidation concentrations) of the peritoneal leukocytes in comparison to those observed in OC group. In addition, peritoneal immune cells from the OA group released lower basal concentrations of pro-inflammatory cytokines (IL-2, IL-6 and TNF-α) compared to those from the OC group. The values of parameters in OA were similar to those in AC group. These improvements in the old mice receiving the probiotic were reflected in an increase in their lifespan. In conclusion, our data indicate that AKK supplementation for a short period could be a good nutritional strategy to promote healthy longevity.

Estrogenic and Antioxidant Activities of Pterocarpus soyauxii (Fabaceae) Heartwood Aqueous Extract in Bilateral Oophorectomized Wistar Rat

Phytoestrogens are used to ease postmenopausal symptoms, a property probably due to estrogenic and antioxidant effects. Pterocarpus soyauxii (P. soyauxii) is empirically used in Cameroon to treat among others primary and secondary amenorrhea. The aim of this study is to evaluate estrogenic and antioxidant activities of P. soyauxii heartwood aqueous extract in bilateral oophorectomized Wistar rats. Firstly, a characterization of the extract was carried out. For that, flavonoids, phenols, and tannins levels in P. soyauxii extract were evaluated by colorimetric assays and UHPLC-MS analysis was realized. In vitro antioxidant analysis of P. soyauxii was conducted using DPPH, ABTS, and FRAP assays. Secondly, 2 sets of pharmacologic tests were carried out. The results revealed that P. soyauxii aqueous extract contains, respectively, 229.42 ± 3.62 mg EAG/g, 63.42 ± 2.16 mg EQ/g, and 27.88 ± 0.23 mg ETA/g of polyphenols, flavonoids, and tannins. UHPLC-MS enabled identifying seven components including mono(2-ethylhexyl) phthalate, cembrene, 3′,5′-dimethoxy-4-stilbenol, and linoleic acid. DPPH, ABTS, and FRAP assays revealed that P. soyauxii extract possessed a high antioxidant activity with IC₅₀ value of 730.20 µg/mL, 892.90 µg/mL, and 765.75 mEAG/g of extract, respectively. In the uterotrophic assay, P. soyauxii extract induced significant increase of fresh uterine weight, uterine and vaginal epithelial size, and mammary glands differentiation compared to Ovx control. In the postmenopausal model, compared to the sham control, vagina and uterine dystrophies were observed in Ovx rats treated with distilled water. P. soyauxii aqueous extract expressed estrogenic-like effects on vagina and did not affect uterine epithelial height compared with vehicle groups. On the back of these vaginotrophic effects, the extract displayed antiatherogenic properties by reducing (p < 0.001) AI and LDL cholesterol level as compared to Ovx control group. The extract at 200 mg/kg significantly prevented the increase of MDA (p < 0.01) level and decreased nitrites (p < 0.001) and GSH (p < 0.01) levels compared to Ovx rats. These beneficial effects are related at least in part to the presence of compound such as mono(2-ethylhexyl) phthalate, 3′,5′-dimethoxy-4-stilbenol, and linoleic acid. Overall, P. soyauxii aqueous extract exhibits estrogenic and antioxidant effects which can inhibit postmenopausal symptoms by providing vaginal stratification, improving lipid profile and insulin sensitivity, and reducing oxidative stress without side effects on the endometrium and mammary gland in 84-day Ovx rats.

Does endurance training prior to ovariectomy protect against myocardial contractility dysfunction in rats?

BACKGROUND

Endurance training prevents cardiac dysfunction induced by menopause, but to date, no studies compared the effects of endurance training prior to menopause versus estrogen replacement therapy during menopause on heart function of rats.

METHODS

Female Wistar rats aged three months were randomly assigned into three groups: Untrained ovariectomized rats (UN-OVX), untrained ovariectomized rats treated with estradiol (UN-OVX-E2), and ovariectomized rats previously exercised (EX-OVX). The endurance training protocol consisted of running on a treadmill at 60-70% of maximal aerobic capacity, 60 min per day, five days per week, for eight weeks. Estradiol replacement therapy consisted of silastic capsules containing the hormone for twelve days. After euthanasia, hearts were harvested, weighed and cardiac function was evaluated by the Langendorff technique.

RESULTS

Both cardiac contractility and relaxation indexes improved similarly in the EX-OVX and UN-OVX-E2 rats compared to UN-OVX.

CONCLUSION

Our findings reveal similar beneficial effects between endurance training previously to menopause and estradiol replacement therapy during menopause on cardiac function of rats.

Effects of Hormone Therapy and Flavonoids Capable on Reversal of Menopausal Immune Senescence

Menopause, probably the most important natural change in a woman’s life and a major component of female senescence, is characterized, inter alia, by cessation of ovarian estrogen and progesterone production, resulting in a gradual deterioration of the female immune system. Hormone replacement therapy (HRT) is used in postmenopausal women to relieve some of the peri- and postmenopausal symptoms, while there is also evidence that the therapy may additionally partially reverse menopausal immune senescence. Flavonoids, and especially isoflavones, are widely used for the treatment of menopausal symptoms, although it is not at present clear whether they can reverse or alleviate other menopausal changes. HRT reverses the menopausal CD4/CD8 ratio and also limits the general peri- and postmenopausal inflammatory state. Moreover, the increased levels of interleukins (IL)-1β, IL-6, and IL-8, as well as of tumor necrosis factor-α (TNF-α) are decreased after the initiation of HRT. However, some reports show no effect of HRT on IL-4, IL-10, and IL-12. It is thus evident that the molecular pathways connecting HRT and female immune senescence need to be clarified. Interestingly, recent studies have suggested that the anti-inflammatory properties of isoflavones possibly interact with inflammatory cytokines when applied in menopause treatments, thereby potentially reversing immune senescence. This narrative review presents the latest data on the effect of menopausal therapies, including administration of flavonoid-rich products, on age-associated immune senescence reversal with the aim of revealing possible directions for future research and treatment development.

A role for estrogen in skin ageing and dermal biomechanics

The skin is the body's primary defence against the external environment, preventing infection and desiccation. Therefore, alterations to skin homeostasis, for example with skin ageing, increase susceptibility to skin disease and injury. Skin biological ageing is uniquely influenced by a combination of intrinsic and extrinsic (primarily photoageing) factors, with differential effects on skin structure and function. Interestingly, skin architecture rapidly changes following the menopause, as a direct result of reduced circulating 17β-estradiol. The traditional clinical benefit of estrogens are supported by recent experimental data, where 17β-estradiol supplementation prevents age-related decline in the skin's structural and mechanical properties. However, the off-target effects of 17β-estradiol continue to challenge therapeutic application. Here we discuss how ageing alters the physiological and structural properties of the dermal extracellular matrix, and explore how estrogen receptor-targeted therapies may restore the mechanical defects associated with skin ageing.

Trabecular bone organoids: a micron-scale 'humanised' prototype designed to study the effects of microgravity and degeneration

Bone is a highly responsive organ, which continuously adapts to the environment it is subjected to in order to withstand metabolic demands. These events are difficult to study in this particular tissue in vivo, due to its rigid, mineralised structure and inaccessibility of the cellular component located within. This manuscript presents the development of a micron-scale bone organoid prototype, a concept that can allow the study of bone processes at the cell-tissue interface. The model is constructed with a combination of primary female osteoblastic and osteoclastic cells, seeded onto femoral head micro-trabeculae, where they recapitulate relevant phenotypes and functions. Subsequently, constructs are inserted into a simulated microgravity bioreactor (NASA-Synthecon) to model a pathological state of reduced mechanical stimulation. In these constructs, we detected osteoclastic bone resorption sites, which were different in morphology in the simulated microgravity group compared to static controls. Once encapsulated in human fibrin and exposed to analogue microgravity for 5 days, masses of bone can be observed being lost from the initial structure, allowing to simulate the bone loss process further. Constructs can function as multicellular, organotypic units. Large osteocytic projections and tubular structures develop from the initial construct into the matrix at the millimetre scale. Micron-level fragments from the initial bone structure are detected travelling along these tubules and carried to sites distant from the native structure, where new matrix formation is initiated. We believe this model allows the study of fine-level physiological processes, which can shed light into pathological bone loss and imbalances in bone remodelling.

Antidementia Effects of Alternanthera philoxeroides in Ovariectomized Mice Supported by NMR-Based Metabolomic Analysis

The crude ethanol extract of the whole plant of Alternanthera philoxeroides (Mart.) Griseb was investigated for its potential as antidementia, induced by estrogen deprivation, based on in vitro antioxidant activity, β-amyloid aggregation inhibition and cholinesterase inhibitory activity, as well as in vivo Morris water maze task (MWMT), novel object recognition task (NORT), and Y-maze task. To better understand the effect of the extract, oxidative stress-induced brain membrane damage through lipid peroxidation in the whole brain was also investigated. Additionally, expressions of neuroinflammatory cytokines (IL-1β, IL-6 and TNF-α) and estrogen receptor-mediated facilitation genes such as PI3K and AKT mRNA in the hippocampus and frontal cortex were also evaluated. These effects were confirmed by the determination of its serum metabolites by NMR metabolomic analysis. Both the crude extract of A. philoxeroides and its flavone constituents were found to inhibit β-amyloid (Aβ) aggregation.

Maca extracts and estrogen replacement therapy in ovariectomized rats exposed at high altitude

PURPOSE

Hormone Replacement Therapy (HRT) and herbal remedies are often used to alleviate menopausal symptoms, but their effects and efficacy at high altitudes presents with several uncertainties. The purpose of this study was to evaluate whether pre-treatment with maca (Lepidium meyenii Walp) improved the tolerance to high altitude on an ovariectomized (OVX) rat model at sea level.

METHOD

The animals were treated with 17β-estradiol (200 µg/kg; E2), red and black maca (1.5 g/kg) for 28 days and exposed at high altitude or sea level.

RESULT

Our findings showed that red and black maca extracts significantly (P < .001) reduced the MDA level in OVX rat serum under hypoxia in a similar way to E2. Red and black maca extracts had similar effects with E2, by significantly (P < .001) reversing and increasing the ovariectomized induced decrease in cornified endometrial cell number. Under hypoxic conditions, the black maca (P < .05) and E2 (P < .01) increased the uterine weight in OVX rats. Finally, E2 alone significantly recovered the frequency of the uterine contractile response.

CONCLUSION

Aqueous extract of L. meyenii partially protects the reproductive function in hypobaric hypoxic environment, through the recovery of the cornified endometrial cells and uterine weight in a menopausal model of OVX rats.

Associations between estradiol and testosterone and depressive symptom scores of the Patient Health Questionnaire-9 in ovariectomized women: a population-based analysis of NHANES data

BACKGROUND

Women are well known to be susceptible to developing affective disorders, yet little attention has been given to effects of ovariectomy-reduced hormones and links with depression. This population-based cross-sectional study aimed to investigate possible associations between ovariectomy-reduced hormones and depression symptom scores of the Patient Health Questionnaire-9 (PHQ-9) in ovariectomized women.

METHODS

Data of PHQ-9 scores, demographics and comorbidities of ovariectomized women were extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) database (2013-2016) and were analyzed retrospectively.

RESULTS

Among ovariectomized women in the NHANES database, serum estradiol levels were significantly positively associated with PHQ-9 scores (ß = 0.014, 95% CI: 0.001, 0.028, P = 0.040), whereas serum testosterone was negatively associated with PHQ-9 scores (ß = -0.033, 95% CI: - 0.048, - 0.018, P < 0.001) after adjusting for confounders. Further stratified analyses revealed that serum estradiol was positively associated with PHQ-9 only among women with history of estrogen use. Serum testosterone levels were negatively associated with PHQ-9 among women with or without prior estrogen use but this was only observed among women aged <  = 60 years (ß = - 0.057, - 0.076, - 0.038, P < 0.001).

CONCLUSIONS

Serum estradiol and testosterone are associated with PHQ-9 scores indicative for depression in ovariectomized women. The associations are modified by age and history of estrogen use. Future prospective studies are warranted to confirm these findings, carefully addressing possible confounding of age-related dementia.

Neuroimmunomodulation by estrogen in health and disease

Systemic homeostasis is maintained by the robust bidirectional regulation of the neuroendocrine-immune network by the active involvement of neural, endocrine and immune mediators. Throughout female reproductive life, gonadal hormones undergo cyclic variations and mediate concomitant modulations of the neuroendocrine-immune network. Dysregulation of the neuroendocrine-immune network occurs during aging as a cumulative effect of declining neural, endocrine and immune functions and loss of compensatory mechanisms including antioxidant enzymes, growth factors and co-factors. This leads to disruption of homeostasis and sets the stage for the development of female-specific age-associated diseases such as autoimmunity, osteoporosis, cardiovascular diseases and hormone-dependent cancers. Ovarian hormones especially estrogen, play a key role in the maintenance of health and homeostasis by modulating the nervous, endocrine and immune functions and thereby altering neuroendocrine-immune homeostasis. Immunologically estrogen's role in the modulation of Th1/Th2 immune functions and contributing to pro-inflammatory conditions and autoimmunity has been widely studied. Centrally, hypothalamic and pituitary hormones influence gonadal hormone secretion in murine models during onset of estrous cycles and are implicated in reproductive aging-associated acyclicity. Loss of estrogen affects neuronal plasticity and the ensuing decline in cognitive functions during reproductive aging in females implicates estrogen in the incidence and progression of neurodegenerative diseases. Peripherally, sympathetic noradrenergic (NA) innervations of lymphoid organs and the presence of both adrenergic (AR) and estrogen receptors (ER) on lymphocytes poise estrogen as a potent neuroimmunomodulator during health and disease. Cyclic variations in estrogen levels throughout reproductive life, perimenopausal surge in estrogen levels followed by its precipitous decline, concomitant with decline in central hypothalamic catecholaminergic activity, peripheral sympathetic NA innervation and associated immunosuppression present an interesting study to explore female-specific age-associated diseases in a new light.

The ratio of prematurely aging to non-prematurely aging mice cohabiting, conditions their behavior, immunity and lifespan

Adult prematurely aging mice (PAM) show behavioral deterioration, premature immunosenescence and increased oxidative stress, impairments that are associated with their shorter lifespan, compared to the corresponding exceptional non-prematurely aging mice (ENPAM). When PAM live in a predominantly ENPAM environment (2/5, respectively) they exhibit an improvement of immunity and redox state in their spleen and thymus leukocytes, and an increased lifespan. Nevertheless, it is unknown if other PAM/ENPAM ratios could affect behavioral and peritoneal leukocyte functions of PAM and change their lifespan. ENPAM and PAM were divided into the following groups: C-ENPAM (8 ENPAM in the cage); C-PAM (8 PAM in the cage); ENPAM>50% and PAM<50% (5 ENPAM/2 PAM in each cage); ENPAM = 50% and PAM = 50% (4 ENPAM/4 PAM in each cage), and PAM>50% and ENPAM<50% (5 PAM/2 ENPAM in each cage). After two months, mice were submitted to a battery of behavioral tests. Several functions and oxidative stress parameters were then assessed in their peritoneal leukocytes. Animals were maintained in these conditions to analyze their lifespan. The results showed that PAM>50%, PAM = 50% and PAM<50% exhibited better behavioral responses, immunity and redox states in their peritoneal leukocytes than C-PAM. This improvement was higher when the number of ENPAM in the cage was increased, with most of the parameters in PAM<50% reaching similar values to those in C-ENPAM, and an increased lifespan. However, ENPAM that cohabited with PAM showed, in general, an impairment of parameters studied. In conclusion, the PAM/ENPAM cohabitation ratio is relevant to behavior and immunity.

Ovary removal modifies liver message RNA profiles in single Comb White Leghorn chickens

Ovaries produce sex hormones, and ovariectomized animals are often used as models for ovarian dysfunction. The liver is a vital organ involved in metabolism and immunity. In the present study, we conducted experiments to investigate the effects of ovariectomy on transcription and metabolic processes in the liver in chicken. Eight Single Comb White Leghorn (SCWL) female chickens were ovariectomized at 17 wk of age, and 8 intact SCWL females served as controls. At 100 wk of age, all chickens were euthanized. High-throughput transcriptome sequencing was performed on liver RNA obtained from ovariectomized and intact females. A total of 267 differentially expressed genes (DEG) were identified in our study. After analysis using DAVID functional annotation tool, one significant Kyoto Encyclopedia of Genes and Genomes pathway, the phosphatidylinositol signaling pathway, was clustered. Gene Ontology enrichment analysis yielded 46 significant Gene Ontology terms. Among terms describing biological processes, the glycerolipid metabolic and lipid localization processes were dominant. The anabolic genes, PEPCK and GK5, and the catabolic genes, VTG1; VTG2; PLD5; DGKQ; DGKE; and FABP3, were detected in ovariectomized chickens. Differentially expressed genes such as ENSGALG00000000162, IL-1Β, SVOPL, and CA12 implied that livers in ovariectomized chickens were subjected to strong inflammatory reactions, whereas defenses against endogenous materials were compromised. A comprehensive view of gene expression in the liver of ovariectomized chickens would advance our understanding of lipid metabolism, glycometabolism, and their relationships to pathologies induced by absence of the ovary. The identified DEG indicated that ovariectomy disturbed lipid metabolism in the liver and was accompanied by an increase in hepatic gluconeogenesis and reductions in phosphatidic acid synthesis and lipid carrier capacity.

Female adipose tissue has improved adaptability and metabolic health compared to males in aged obesity

Aging, like obesity, is associated with metabolic and inflammatory alterations within adipose tissue in older individuals. Younger females are protected from adipose inflammation, but older post-menopausal females exhibit exaggerated visceral adiposity correlated with increased disease risk. Obesity accelerates the onset and progression of age-associated diseases, but it is unclear if aging and obesity drive adipose tissue dysfunction in a sexually dimorphic fashion. We investigated adipose tissue metabolism and inflammation in a diet-induced obesity model in young and old mice. We identified age related sex differences in adipose tissue macrophages (ATMs), fibrosis and lipid metabolism in male and female visceral fat depot (GWAT). Although aging normalized body weights between the sexes, females remained protected from proinflammatory ATMs and stimulated lipolysis failed to adversely affect the inflammatory state even with obesity. Older obese males had augmented CD11c⁺ ATMs and higher insulin levels, while females showed increased visceral adiposity and exaggerated Pparγ, and Pgc1α expression. Obesity in aging demonstrated similar expression of GWAT p53, p16, p21, Timp1 and Tgfβ1 in both sexes. Our studies suggest that even with aging, female GWAT shows an attenuated inflammatory response compared to males due to an efficient oxidative metabolism combined with an active tissue remodeling state.

Effects of lipoic acid and ω-3 long-chain polyunsaturated fatty acids on the kidney in the ovariectomized rat model of menopause

OBJECTIVES

The loss of antioxidant protection from estrogen during menopause may lead to oxidative stress in the kidneys. Thus, antioxidant supplementation may potentially decrease the menopause-derived oxidative stress. The aim of this study was to evaluate the effect of α-lipoic acid (LA) and ω-3 long-chain polyunsaturated fatty acids on the redox profile of the kidneys in the ovariectomized rat model of menopause.

METHODS

We assessed oxidative damage markers and antioxidant defenses in the kidneys of ovariectomized rats supplemented with LA, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Animals received 3 mo of dietary supplementation.

RESULTS

Ovariectomy did not increase the levels of the damage markers carbonyl and malondialdehyde. EPA supplementation increased carbonyl and malondialdehyde levels. Ovariectomy increased fumarase activity but did not affect the levels of vitamin C, glutathione, and glutathione S-transferase activity. LA, DHA, and EPA supplementation decreased fumarase activity, but increased the levels of vitamin C, glutathione, and glutathione S-transferase activity. Vitamin E, superoxide dismutase, glutathione peroxidase, and peroxide consumption were not affected by ovariectomy or supplementation.

CONCLUSIONS

The results suggest that ovariectomy did not affect the redox profile in the kidneys. LA, DHA, and EPA supplementation increased certain endogenous antioxidants; however, EPA may have a prooxidant effect on the kidneys.

Impacts of the late adulthood diet-induced obesity onset on behavior, immune function, redox state and life span of male and female mice

The aim of the present study was to investigate whether the late onset of diet-induced obesity (DIO) in middle-aged mice affected behavioral, immunological and oxidative stress parameters as well as life span of male and female mice. Also, it was analyzed whether the late DIO onset aggravated immunosenescence in old female mice. Late-adult male and female ICR/CD1 mice (28 weeks old) were fed either a high-fat diet or a standard diet during 14 weeks. After that, in these middle-aged (42 weeks old) diet-induced obese (DIO) and non-DIO controls, behavior as well as functions and redox state of peritoneal leukocytes were evaluated. These same parameters (excepting behavioral tests) were repeated when female mice were old (72 weeks old). The results showed lower exploratory activity and higher anxiety-like behavior in middle-aged male and female DIO than in controls. Moreover, these DIO animals from both sexes exhibited statistically significant impaired immune cell functions, such as chemotaxis of macrophages and lymphocytes, phagocytosis of macrophages, natural killer activity and lymphoproliferation in response to ConA and LPS, as well as an oxidative stress state in comparison with controls. Male DIO mice exhibited higher impairments in a variety of the evaluated parameters and a shorter life span than their female counterparts. In addition, female DIO mice, at old age, showed aggravated immunosenescence. In conclusion, the late DIO onset leads to impairments in behavior as well as in immune system functions of middle-aged male and female mice, males being significantly more affected than females.

Estrogen-Dependent Disruption of Adiponectin-Connexin43 Signaling Underlies Exacerbated Myocardial Dysfunction in Diabetic Female Rats

The reasons for the higher severity of type 2 diabetes (T2DM)-associated cardiomyopathy in women, despite their inherent estrogen (E₂)-dependent cardioprotection, remain unknown. We hypothesized that the reliance of the healthy females' hearts on augmented adiponectin (APN)-connexin 43 (Cx43) signaling becomes paradoxically detrimental when disrupted by T2DM in an E₂-dependent manner. We tested this hypothesis in high-fat, low- dose streptozotocin diabetic rats and their controls with the following designations: 1) sham-operated (SO), 2) ovariectomized (OVX), 3) ovariectomized with E₂ supplementation (OVX + E₂), and 4) male. E₂-replete (SO or OVX + E₂) diabetic rats exhibited higher mortality and greater increases in left ventricular (LV) mass and reduced LV developed pressure, LV contractility, and fractional shortening but preserved ejection fraction. Further, compared with respective nondiabetic counterparts, the hearts of these E₂-replete diabetic rats exhibited greater upregulation of cardiac estrogen receptor α and reductions in Cx43 expression and in the phosphorylation levels of the survival molecules extracellular regulating kinases 1/2 and phosphorylated AKT (pAKT). Whereas serum APN was reduced, independent of sex and ovarian hormone status in all DM rats, cardiac APN was most drastically reduced in DM SO rats. The present translational findings are the first to implicate ovarian hormones/E₂ in the exacerbated myocardial dysfunction in female diabetic subjects and to suggest a pivotal role for malfunctioning cardiac APN-Cx43 signaling in this sex/E₂-specific clinical problem.

Premature aging in behavior and immune functions in tyrosine hydroxylase haploinsufficient female mice. A longitudinal study

Aging is accompanied by impairment in the nervous, immune, and endocrine systems as well as in neuroimmunoendocrine communication. In this context, there is an age-related alteration of the physiological response to acute stress, which is modulated by catecholamine (CA), final products of the sympathetic-adreno-medullary axis. The involvement of CA in essential functions of the nervous system is consistent with the neuropsychological deficits found in mice with haploinsufficiency (hemizygous; HZ) of tyrosine hydroxylase (TH) enzyme (TH-HZ). However, other possible alterations in regulatory systems have not been studied in these animals. The aim of the present work was to analyze whether adult TH-HZ female mice presented the impairment of behavioral traits and immunological responses that occurs with aging and whether they had affected their mean lifespan. ICR-CD1 female TH-HZ and wild type (WT) mice were used in a longitudinal study. Behavioral tests were performed on adult and old mice in order to evaluate their sensorimotor abilities and exploratory capacity, as well as anxiety-like behaviors. At the ages of 2 ± 1, 4 ± 1, 9 ± 1, 13 ± 1 and 20 ± 1 months, peritoneal leukocytes were extracted and several immune functions were assessed (phagocytic capacity, Natural Killer (NK) cytotoxicity, and lymphoproliferative response to lipopolysaccharide (LPS) and concanavalin A (ConA)). In addition, several oxidative stress parameters (catalase, glutathione reductase and glutathione peroxidase activities, and reduced glutathione (GSH) concentrations as antioxidant compounds as well as xanthine oxidase activity, oxidized glutathione (GSSG) concentrations, and GSSG/GSH ratio as oxidants) were analyzed. As inflammatory stress parameters TNF-alpha and IL-10 concentrations, and TNF-alpha/IL-10 ratios as inflammatory/anti-inflammatory markers, were measured. Animals were maintained in standard conditions until their natural death. The results indicate that adult TH-HZ mice presented worse sensorimotor abilities and exploratory capacity than their WT littermates as well as greater anxiety-like behaviors. With regards to the immune system, adult TH-HZ animals exhibited lower values of phagocytic capacity, NK cytotoxicity, and lymphoproliferative response to LPS and ConA than WT mice. Moreover, immune cells of TH-HZ mice showed higher oxidative and inflammatory stress than those of WT animals. Although these differences between TH-HZ and WT, in general, decreased with aging, this premature immunosenescence and impairment of behavior of TH-HZ mice was accompanied by a shorter mean lifespan in comparison to WT counterparts. In conclusion, haploinsufficiency of th gene in female mice appears to provoke premature aging of the regulatory systems affecting mean lifespan.

Effects of Estradiol on Histological Parameters and Secretory Ability of Pituitary Mammotrophs in Ovariectomized Female Rats

Objective

Estrogen replacement therapy remains current as a therapeutic approach to treat menopausal symptoms and may significantly affect hormone-producing cells in the female pituitaries. The aim of this study was to examine the histological parameters of pituitary mammotrophs and prolactin secretion after chronic estradiol treatment in ovariectomized adult female rats, reflecting premature menopause.

Materials and Methods

In this experimental study, adult female Wistar rats were divided into non-ovariectomized (C), ovariectomized (OVX) and estradiol-treated ovariectomized (OVX+E) groups. Estradiol dipropionate [0.625 mg/kg body mass per day] was administered for four weeks, while the C and OVX groups received vehicle alone. Mammotrophs were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure, while prolactin concentrations were measured by the non-isotopic two-step assay (Delfia) method. Comparison of the differences between groups was performed using one-way analysis of variance (ANOVA) and Tukay (honest significant difference) HSD test.

Results

Ovariectomy caused significant (P<0.05) decreases in mammotroph optical density (OD), volume density (V_V) and number per mm² by 29, 27 and 34%, respectively, in comparison with the C females. In the OVX+E group, significant (P<0.05) increases in OD, cell volume, V_Vand number of mammotrophs per mm² by 181, 15%, 5.8-fold and 5.2-fold, respectively, were observed when compared to OVX animals. The serum prolactin concentration in OVX females was significantly (P<0.05) decreased by 14% in comparison to the C group, while in OVX+E females, prolactin levels were significantly (P<0.05) increased by 53% compared to the OVX controls.

Conclusion

Estradiol supplementation in ovariectomized females is followed by stimulatory histological and secretory changes of the mammotrophs. These results could serve as indicators of possible prolactinome development upon estradiol application in premature menopausal subjects.

The role of estrogen in cutaneous ageing and repair

Combined advances in modern medical practice and increased human longevity are driving an ever-expanding elderly population. Females are particularly at risk of age-associated pathology, spending more of their lives in a post-menopausal state. Menopause, denoted by a rapid decline in serum sex steroid levels, accelerates biological ageing across the body's tissues. Post-menopause physiological changes are particularly noticeable in the skin, which loses structural architecture and becomes prone to damage. The sex steroid most widely discussed as an intrinsic contributor to skin ageing and pathological healing is 17β-estradiol (or estrogen), although many others are involved. Estrogen deficiency is detrimental to many wound-healing processes, notably inflammation and re-granulation, while exogenous estrogen treatment widely reverses these effects. Over recent decades, many of the molecular and cellular correlates to estrogen's beneficial effect on normal skin homeostasis and wound healing have been reported. However, disparities still exist, particularly in the context of mechanistic studies investigating estrogen receptor signalling and its potential cellular effects. New molecular techniques, coupled with increased understanding of estrogen in skin biology, will provide further opportunities to develop estrogen receptor-targeted therapeutics.

Changes in the Level of Immunoglobulins and CD4/CD8 Ratio in Young and Aged Mice with Estradiol Deficiency

Studies demonstrated that deficiency in 17β-estradiol (E₂) in postmenopausal women influences their immune system. However, few studies have reported alterations in immunologic presentation during nonnatural menopause in young females. Here we compared the differences in immune response between young C57BL/6N mice with surgical or medical variectomy and aged C57BL/6N mice with the common feature of E₂ deficiency following Con A stimulation. We observed inverted CD4/CD8 ratios in the aged group and apparent reduced production of serum immunoglobin (Ig)G, IgA, and IgM in the surgical group, whereas changes in immune parameters in the medical group were moderate. These data suggested that the immunological response to Con A stimulus differed among the three groups and that E₂ deficiency was only partially responsible for the development of immune deficiency in aged mice.

Impact of Estrogen Therapy on Lymphocyte Homeostasis and the Response to Seasonal Influenza Vaccine in Post-Menopausal Women

It is widely recognized that changes in levels of ovarian steroids modulate severity of autoimmune disease and immune function in young adult women. These observations suggest that the loss of ovarian steroids associated with menopause could affect the age-related decline in immune function, known as immune senescence. Therefore, in this study, we determined the impact of menopause and estrogen therapy (ET) on lymphocyte subset frequency as well as the immune response to seasonal influenza vaccine in three different groups: 1) young adult women (regular menstrual cycles, not on hormonal contraception); 2) post-menopausal (at least 2 years) women who are not receiving any form of hormone therapy (HT) and 3) post-menopausal hysterectomized women receiving ET. Although the numbers of circulating CD4 and CD20 B cells were reduced in the post-menopausal group receiving ET, we also detected a better preservation of naïve B cells, decreased CD4 T cell inflammatory cytokine production, and slightly lower circulating levels of the pro-inflammatory cytokine IL-6. Following vaccination, young adult women generated more robust antibody and T cell responses than both post-menopausal groups. Despite similar vaccine responses between the two post-menopausal groups, we observed a direct correlation between plasma 17β estradiol (E2) levels and fold increase in IgG titers within the ET group. These findings suggest that ET affects immune homeostasis and that higher plasma E2 levels may enhance humoral responses in post-menopausal women.

Effects of edible bird's nest on hippocampal and cortical neurodegeneration in ovariectomized rats

The aim of this research is to investigate whether edible bird's nest (EBN) attenuates cortical and hippocampal neurodegeneration in ovariectomized rats. Ovariectomized rats were randomly divided into seven experimental groups (n = 6): the ovariectomy (OVX) group had their ovaries surgically removed; the sham group underwent surgical procedure similar to OVX group, but ovaries were left intact; estrogen group had OVX and received estrogen therapy (0.2 mg kg(-1) per day); EBN treatment groups received 6%, 3%, and 1.5% EBN, respectively. Control group was not ovariectomized. After 12 weeks of intervention, biochemical assays were performed for markers of neurodegeneration, and messenger ribonucleic acid (mRNA) levels of oxidative stress-related genes in the hippocampus and frontal cortex of the brain were analysed. Caspase 3 (cysteine-aspartic proteases 3) protein levels in the hippocampus and frontal cortex were also determined using western blotting. The results show that EBNs significantly decreased estrogen deficiency-associated serum elevation of advanced glycation end-products (AGEs), and they changed redox status as evidenced by oxidative damage (malondialdehyde content) and enzymatic antioxidant defense (superoxide dismutase and catalase) markers. Furthermore, genes associated with neurodegeneration and apoptosis were downregulated in the hippocampus and frontal cortex by EBN supplementation. Taken together, the results suggest that EBN has potential for neuroprotection against estrogen deficiency-associated senescence, at least in part via modification of the redox system and attenuation of AGEs.

Plasmid DNA-coding p62 as a bone effective anti-inflammatory/anabolic agent

We recently reported that a DNA plasmid coding p62-SQSTM1 acts as an effective anti tumor vaccine against both transplantable mouse tumors and canine spontaneous mammary neoplasms. Here we report the unexpected finding that intramuscular delivery of p62 DNA exerts a powerful anti-osteoporotic activity in a mouse model of inflammatory bone loss (i.e, ovariectomy) by combining bone-sparing and osteo-synthetic effects. Notably, the suppression of osteoporosis by p62DNA was associated with a sharp down-regulation of master inflammatory cytokines, and up-regulation of endogenous p62 protein by bone-marrow stromal cells. The present data provide a solid rational to apply p62 DNA vaccine as a safe, new therapeutic for treatment of inflammatory related bone loss diseases.

Curcumin Supplementation Decreases Intestinal Adiposity Accumulation, Serum Cholesterol Alterations, and Oxidative Stress in Ovariectomized Rats

The aim of this study was to investigate the potential of curcumin oral supplementation (50 and 100 mg/Kg/day, for 30 days) in circumventing menopause-associated oxidative stress and lipid profile dysfunctions in a rat ovariectomy (OVX) model. Female Wistar rats were operated and randomly divided into either sham-operated or OVX groups. Sham-operated group (n = 8) and one OVX group (n = 11) were treated with vehicle (refined olive oil), and the other two OVX groups received curcumin at 50 or 100 mg/Kg/day doses (n = 8/group). OVX vehicle-treated animals presented a higher deposition of intestinal adipose tissue as well as increased serum levels of IL-6, LDL, and total cholesterol when compared to sham-operated rats. In addition, several oxidative stress markers in serum, blood, and liver (such as TBARS, carbonyl, reduced-sulphydryl, and nonenzymatic antioxidant defenses) were altered toward a prooxidant status by OVX. Interestingly, curcumin supplementation attenuated most of these parameters to sham comparable values. Thus, the herein presented results show that curcumin may be useful to ameliorate lipid metabolism alterations and oxidative damage associated with hormone deprivation in menopause.

Luteinizing hormone: Evidence for direct action in the CNS

This article is part of a Special Issue "SBN 2014". Hormonal dysfunction due to aging, especially during menopause, plays a substantial role in cognitive decline as well as the progression and development of neurodegenerative diseases. The hypothalamic-pituitary-gonadal (HPG) axis has long been implicated in changes in behavior and neuronal morphology. Most notably, estrogens have proven beneficial in the healthy brain through a host of different mechanisms. Recently, luteinizing hormone (LH) has emerged as a candidate for further investigation for its role in the CNS. The basis of this is that both LH and the LH receptor are expressed in the brain, and serum levels of LH correlate with cognitive deficits and Alzheimer's disease (AD) incidence. The study of LH in cognition and AD primarily focuses on evaluating the effects of downregulation of this peptide. This literature has shown that decreasing peripheral LH, through a variety of pharmacological interventions, reduces cognitive deficits in ovariectomy and AD models. However, few studies have researched the direct actions of LH on neurons and glial cells. Here we summarize the role of luteinizing hormone in modulating cognition, and we propose a mechanism that underlies a role for brain LH in this process.

Estrogen upregulates inflammatory signals through NF-κB, IFN-γ, and nitric oxide via Akt/mTOR pathway in the lymph node lymphocytes of middle-aged female rats

The alterations in the secretion of sex steroids, especially estrogen, in females throughout reproductive life and its decline with age alters the functions of the neuroendocrine-immune network and renders them susceptible to age-related diseases and cancers. This study investigates the mechanisms of estrogen-induced alterations in cell-mediated immune and inflammatory responses in the lymphocytes from lymph nodes (axillary and inguinal) of ovariectomized (OVX) middle-aged female rats. Ovariectomized middle-aged (MA) Sprague-Dawley female rats (n=8) were implanted with 17β-estradiol (E2) 30-day release pellets (0.6 and 300μg). At the end of the treatment period, lymph nodes (axillary and inguinal) were isolated and examined for serum 17β-estradiol, lymphoproliferation, cytokine production, expression of p-Akt, p-mTOR, p-IκB-α and p-NF-κB (p50 and p65), extent of lipid peroxidation, nitric oxide (NO) production, cytochrome c oxidase activity and reactive oxygen species (ROS) production. There was an OVX-related decline in serum 17β-estradiol level, Con A-induced lymphoproliferation, p-Akt and p-mTOR expression, and cytochrome c oxidase (COX) activity. E2 supplementation increased serum 17β-estradiol level, lymphoproliferation, expression of p-Akt, p-mTOR, p-IκB-α and p-NF-κB (p50 and p65), lipid peroxidation, IFN-γ, TNF-α, ROS and NO production, while it decreased IL-6 production. E2 mediates inflammatory responses by increasing the levels of NO and TNF-α by up regulating IFN-γ and simultaneously promotes aging through the generation of free radicals as reflected by increased lipid peroxidation and ROS production in lymph nodes. These findings may have wide implications to immunity and inflammatory disorders including autoimmune diseases predominantly prevalent in females.

17α-Estradiol: a candidate neuroserm and non-feminizing estrogen for postmenopausal neuronal complications

Extensive evidence suggests that decline in ovarian function with menopause is associated with neuronal dysfunction. Major cause of this is rise in oxidative stress and inflammatory cytokines because of estrogen deficiency. 17β-Estradiol (E2, hormone with potent antioxidant and anti-inflammatory activity) has profound protective actions on multiple organ systems, but feminizing side effects of β-estradiol limits its clinical efficacy. 17α-Estradiol (E2α), a non feminizing congener, gives a ray of hope to the scientific community as an alternative strategy to treat menopause associated neuronal pathologies. We assessed the protective actions of 17α-estradiol (5, 10μg/kg) against cognitive deficits, depression and motor coordination after 4weeks of ovariectomy in rats and compared its efficacy with E2 at same doses. After the behavioral assay animals were sacrificed and their brains were harvested for biochemical studies. Uterine weights were also assessed. E2 and E2α (5, 10μg/kg) were equally protective against attenuating cognitive deficits, depressive symptoms and motor incoordination in OVX rats. Both demonstrated significant antioxidant activity and E2, but not E2α, increased serum estradiol levels and proliferated uterine weights, markers of feminizing action. It can thus be concluded that E2α offers safe alternative to E2 in protecting against menopausal neuropathologies.

Histophysiology of the immune system of Wistar rats at delayed terms after ovariectomy

We studied histophysiological changes in organs of the immune system, liver, and lungs of Wistar rats at delayed terms after ovariectomy. On day 52 after surgical castration leading to a decrease in estradiol, progesterone, and testosterone levels, activation of the immune system was revealed characterized by stage I accidental thymus involution, while pulp depletion in the spleen, and enhanced IL-2 and IFN-γ production. We also observed small-droplet degeneration of hepatocytes and reactive changes in the lungs manifested in increased number of neutrophils in the interalveolar septa.

Physical exercise neuroprotects ovariectomized 3xTg-AD mice through BDNF mechanisms

Postmenopausal women may be more vulnerable to cognitive loss and Alzheimer's disease (AD) than premenopausal women because of their deficiency in estrogens, in addition to their usually older age. Aerobic physical exercise has been proposed as a therapeutic approach for maintaining health and well-being in postmenopausal women, and for improving brain health and plasticity in populations at high risk for AD. To study the neuroprotective mechanisms of physical exercise in a postmenopausal animal model, we submitted previously ovariectomized, six-month old non-transgenic and 3xTg-AD mice to three months of voluntary exercise in a running wheel. At nine months of age, we observed lower grip strength and some exacerbation of the behavioral and psychological symptoms of dementia (BPSD)-like involving active exploratory activities. A similar major cognitive impairment was observed of ovariectomized 3xTg-AD mice in comparison with sham-operated 3xTg-AD mice. A reduction of bodily fitness and lack of retention of memory were observed in the ovariectomized non-transgenic mice. Physical exercise protected against all deleterious behaviors and normalized learning and memory. It also protected against body frailty, as expected. Analyses of hippocampal key markers of antioxidant and neuroplasticity signaling pathways, showed that ovariectomy impairs the activation of CREB through physical exercise. Furthermore, molecular and behavioral correlates suggested a central role of BDNF in the neuroprotection mediated by physical exercise therapy against apathy and memory loss induced by ovariectomy and the AD-genotype.

Lifelong treatment with atenolol decreases membrane fatty acid unsaturation and oxidative stress in heart and skeletal muscle mitochondria and improves immunity and behavior, without changing mice longevity

The membrane fatty acid unsaturation hypothesis of aging and longevity is experimentally tested for the first time in mammals. Lifelong treatment of mice with the β1-blocker atenolol increased the amount of the extracellular-signal-regulated kinase signaling protein and successfully decreased one of the two traits appropriately correlating with animal longevity, the membrane fatty acid unsaturation degree of cardiac and skeletal muscle mitochondria, changing their lipid profile toward that present in much more longer-lived mammals. This was mainly due to decreases in 22:6n-3 and increases in 18:1n-9 fatty acids. The atenolol treatment also lowered visceral adiposity (by 24%), decreased mitochondrial protein oxidative, glycoxidative, and lipoxidative damage in both organs, and lowered oxidative damage in heart mitochondrial DNA. Atenolol also improved various immune (chemotaxis and natural killer activities) and behavioral functions (equilibrium, motor coordination, and muscular vigor). It also totally or partially prevented the aging-related detrimental changes observed in mitochondrial membrane unsaturation, protein oxidative modifications, and immune and behavioral functions, without changing longevity. The controls reached 3.93 years of age, a substantially higher maximum longevity than the best previously described for this strain (3.0 years). Side effects of the drug could have masked a likely lowering of the endogenous aging rate induced by the decrease in membrane fatty acid unsaturation. We conclude that it is atenolol that failed to increase longevity, and likely not the decrease in membrane unsaturation induced by the drug.

Animal models for the effective development of atrophic vaginitis therapies: possibilities and limitations

INTRODUCTION

Vaginal atrophy (VA) is an inflammation of the vagina that develops when there is a significant decrease in levels of the estrogen. Prolonged periods of hypoestrogenism may induce severe VA and treatment is essential. This is a significant problem which requires more focused attention for the development of existing and future therapies.

AREAS COVERED

This review evaluates the suitable animal models of VA, including: mice, rodents and non-human primates. It focuses particularly on the possibilities and limitations of these in vivo models for the effective development of VA therapies.

EXPERT OPINION

Hormone replacement therapy (HRT) has been prescribed and successfully used for VA. However, some studies have shown that HRT may be linked to an increased risk of breast cancer, coronary heart diseases and others risks. Thus, there is a growing interest in effective and safe alternatives to VA symptoms. There are, however, a number of things that must be considered for future drug discovery efforts. One major consideration is what animal model should be used and whether the model is appropriate for the study aim. Similarly, research studies must also consider the influencing factors on these animal models, so that these models can effectively mimic the actual disease. The authors also highlight the need to standardize research parameters to produce more reliable and reproducible data.