A randomized pilot trial of estrogen replacement therapy in post-menopausal women with Parkinson's disease

Reproductive life factors and estro-progestin exposure in women with early-onset Parkinson's disease compared to late-onset disease and controls: A retrospective cohort study

BACKGROUND

Parkinson's disease (PD) is more common in men than women. Although hormonal factors may partially explain this difference, there are no studies evaluating reproductive life factors and exogenous estroprogestin exposure in women with Early Onset Parkinson Disease (EOPD).

OBJECTIVE

To compare reproductive life factors and exogenous estroprogestin exposure among female patients with EOPD, late-onset Parkinson's disease (LOPD), and EOPD-matched unaffected controls.

METHODS

We identified female patients with EOPD from 1989 to 2021, defining EOPD as PD with motor-symptoms onset before age 50 and LOPD as PD with motor onset after 50. We paired EOPD patients to age-matched, unaffected controls. We reviewed medical records to determine demographic characteristics, clinical history, and reported reproductive menopausal history (reviewing medical records).

RESULTS

We included 87 EOPD patients, 84 LOPD patients, and 91 unaffected controls with information about reproductive life factors and exogenous estroprogestin exposure in their medical records. There were no significant differences in race, ethnicity, or BMI between the three groups. EOPD patients were more likely to have used hormonal contraception than LOPD patients (23/49 (47 %) vs 0/84 (0 %), p < 0.001). LOPD patients had higher numbers of pelvic surgeries (48/84 [57 %] in LOPD, 23/87 [26 %] in EOPD, p < 0.001) and higher usage of perimenopausal hormonal therapy (52/84 [62 %] in LOPD, 10/87 [11 %] in EOPD, p < 0.001) in LOPD than EOPD.

CONCLUSIONS

Our study reports no significant difference in reproductive life factors and exogenous estroprogestin exposure between controls and EOPD patients, except for higher exposure to hormonal contraception in EOPD. There was no apparent difference in reproductive life factors and exogenous estroprogestin exposure between EOPD and LOPD patients. Our findings therefore do not observe that hormonal exposure is different between earlier onset of female EOPD compared to female LOPD patients, or between female EOPD patients and unaffected female controls.

The impact of VPS35 D620N mutation on alternative autophagy and its reversal by estrogen in Parkinson's disease

VPS35 plays a key role in neurodegenerative processes in Alzheimer's disease and Parkinson's disease (PD). Many genetic studies have shown a close relationship between autophagy and PD pathophysiology, and specifically, the PD-causing D620N mutation in VPS35 has been shown to impair autophagy. However, the molecular mechanisms underlying neuronal cell death and impaired autophagy in PD are debated. Notably, increasing evidence suggests that Rab9-dependent "alternative" autophagy, which is driven by a different molecular mechanism that driving ATG5-dependent "conventional" autophagy, also contributes to neurodegenerative process. In this study, we investigated the relationship between alternative autophagy and VPS35 D620N mutant-related PD pathogenesis. We isolated iPSCs from the blood mononuclear cell population of two PD patients carrying the VPS35 D620N mutant. In addition, we used CRISPR-Cas9 to generate SH-SY5Y cells carrying the D620N variant of VPS35. We first revealed that the number of autophagic vacuoles was significantly decreased in ATG5-knockout Mouse Embryonic Fibroblast or ATG5-knockdown patient-derived dopaminergic neurons carrying the VPS35 D620N mutant compared with that of the wild type VPS35 control cells. Furthermore, estrogen, which activates alternative autophagy pathways, increased the number of autophagic vacuoles in ATG5-knockdown VPS35 D620N mutant dopaminergic neurons. Estrogen induces Rab9 phosphorylation, mediated through Ulk1 phosphorylation, ultimately regulating alternative autophagy. Moreover, estrogen reduced the apoptosis rate of VPS35 D620N neurons, and this effect of estrogen was diminished under alternative autophagy knockdown conditions. In conclusion, alternative autophagy might be important for maintaining neuronal homeostasis and may be associated with the neuroprotective effect of estrogen in PD with VPS35 D620N.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

The role of genetics and gender specific differences in neurodegenerative disorders: Insights from molecular and immune landscape

Neurodegenerative disorders (NDDs) are the most common neurological disorders with high prevalence and have significant socioeconomic implications. Understanding the underlying cellular and molecular mechanisms associated with the immune system can be effective in disease etiology, leading to more effective therapeutic approaches for both females and males. The central nervous system (CNS) actively participates in immune responses, both within and outside the CNS. Immune system activation is a common feature in NDDs. Gender-specific factors play a significant role in the prevalence, progression, and manifestation of NDDs. Neuroinflammation, in both inflammatory neurological and neurodegenerative conditions, is defined by the triggering of microglia and astrocyte cell activation. This results in the secretion of pro-inflammatory cytokines and chemokines. Numerous studies have documented the role of neuroinflammation in neurological diseases, highlighting the involvement of immune signaling pathways in disease development. Converging evidence support immune system involvement during neurodegeneration in NDDs. In this review, we summarize emerging evidence that reveals gender-dependent differences in immune responses related to NDDs. Also, we highlight sex differences in immune responses and discuss how these sex-specific influences can increase the risk of NDDs. Understanding the role of gender-specific factors can aid in developing targeted therapeutic strategies and improving patient outcomes. Ultimately, the better understanding of these mechanisms contributed to sex-dependent immune response in NDDs, can be critically usful in targeting of immune signaling cascades in such disorders. In this regard, sex-related immune responses in NDDs may be promising and effective targets in therapeutic strategies.

Hormone therapy for sexual function in perimenopausal and postmenopausal women

BACKGROUND

The perimenopausal and postmenopausal periods are associated with many symptoms, including sexual complaints. This review is an update of a review first published in 2013.

OBJECTIVES

We aimed to assess the effect of hormone therapy on sexual function in perimenopausal and postmenopausal women.

SEARCH METHODS

On 19 December 2022 we searched the Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, ISI Web of Science, two trials registries, and OpenGrey, together with reference checking and contact with experts in the field for any additional studies.

SELECTION CRITERIA

We included randomized controlled trials that compared hormone therapy to either placebo or no intervention (control) using any validated assessment tool to evaluate sexual function. We considered hormone therapy: estrogen alone; estrogen in combination with progestogens; synthetic steroids, for example, tibolone; selective estrogen receptor modulators (SERMs), for example, raloxifene, bazedoxifene; and SERMs in combination with estrogen.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. We analyzed data using mean differences (MDs) and standardized mean differences (SMDs). The primary outcome was the sexual function score. Secondary outcomes were the domains of sexual response: desire; arousal; lubrication; orgasm; satisfaction; and pain. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 36 studies (23,299 women; 12,225 intervention group; 11,074 control group), of which 35 evaluated postmenopausal women; only one study evaluated perimenopausal women. The 'symptomatic or early postmenopausal women' subgroup included 10 studies, which included women experiencing menopausal symptoms (symptoms such as hot flushes, night sweats, sleep disturbance, vaginal atrophy, and dyspareunia) or early postmenopausal women (within five years after menopause). The 'unselected postmenopausal women' subgroup included 26 studies, which included women regardless of menopausal symptoms and women whose last menstrual period was more than five years earlier. No study included only women with sexual dysfunction and only seven studies evaluated sexual function as a primary outcome. We deemed 20 studies at high risk of bias, two studies at low risk, and the other 14 studies at unclear risk of bias. Nineteen studies received commercial funding. Estrogen alone versus control probably slightly improves the sexual function composite score in symptomatic or early postmenopausal women (SMD 0.50, 95% confidence interval (CI) (0.04 to 0.96; I² = 88%; 3 studies, 699 women; moderate-quality evidence), and probably makes little or no difference to the sexual function composite score in unselected postmenopausal women (SMD 0.64, 95% CI -0.12 to 1.41; I² = 94%; 6 studies, 608 women; moderate-quality evidence). The pooled result suggests that estrogen alone versus placebo or no intervention probably slightly improves sexual function composite score (SMD 0.60, 95% CI 0.16 to 1.04; I² = 92%; 9 studies, 1307 women, moderate-quality evidence). We are uncertain of the effect of estrogen combined with progestogens versus placebo or no intervention on the sexual function composite score in unselected postmenopausal women (MD 0.08 95% CI -1.52 to 1.68; 1 study, 104 women; very low-quality evidence). We are uncertain of the effect of synthetic steroids versus control on the sexual function composite score in symptomatic or early postmenopausal women (SMD 1.32, 95% CI 1.18 to 1.47; 1 study, 883 women; very low-quality evidence) and of their effect in unselected postmenopausal women (SMD 0.46, 95% CI 0.07 to 0.85; 1 study, 105 women; very low-quality evidence). We are uncertain of the effect of SERMs versus control on the sexual function composite score in symptomatic or early postmenopausal women (MD -1.00, 95% CI -2.00 to -0.00; 1 study, 215 women; very low-quality evidence) and of their effect in unselected postmenopausal women (MD 2.24, 95% 1.37 to 3.11 2 studies, 1525 women, I² = 1%, low-quality evidence). We are uncertain of the effect of SERMs combined with estrogen versus control on the sexual function composite score in symptomatic or early postmenopausal women (SMD 0.22, 95% CI 0.00 to 0.43; 1 study, 542 women; very low-quality evidence) and of their effect in unselected postmenopausal women (SMD 2.79, 95% CI 2.41 to 3.18; 1 study, 272 women; very low-quality evidence). The observed heterogeneity in many analyses may be caused by variations in the interventions and doses used, and by different tools used for assessment.

AUTHORS' CONCLUSIONS

Hormone therapy treatment with estrogen alone probably slightly improves the sexual function composite score in women with menopausal symptoms or in early postmenopause (within five years of amenorrhoea), and in unselected postmenopausal women, especially in the lubrication, pain, and satisfaction domains. We are uncertain whether estrogen combined with progestogens improves the sexual function composite score in unselected postmenopausal women. Evidence regarding other hormone therapies (synthetic steroids and SERMs) is of very low quality and we are uncertain of their effect on sexual function. The current evidence does not suggest the beneficial effects of synthetic steroids (for example tibolone) or SERMs alone or combined with estrogen on sexual function. More studies that evaluate the effect of estrogen combined with progestogens, synthetic steroids, SERMs, and SERMs combined with estrogen would improve the quality of the evidence for the effect of these treatments on sexual function in perimenopausal and postmenopausal women.

Sex differences in alpha-synucleinopathies: a systematic review

Background

Past research indicates a higher prevalence, incidence, and severe clinical manifestations of alpha-synucleinopathies in men, leading to a suggestion of neuroprotective properties of female sex hormones (especially estrogen). The potential pathomechanisms of any such effect on alpha-synucleinopathies, however, are far from understood. With that aim, we undertook to systematically review, and to critically assess, contemporary evidence on sex and gender differences in alpha-synucleinopathies using a bench-to-bedside approach.

Methods

In this systematic review, studies investigating sex and gender differences in alpha-synucleinopathies (Rapid Eye Movement (REM) Behavior Disorder (RBD), Parkinson's Disease (PD), Dementia with Lewy Bodies (DLB), Multiple System Atrophy (MSA)) from 2012 to 2022 were identified using electronic database searches of PubMed, Embase and Ovid.

Results

One hundred sixty-two studies were included; 5 RBD, 6 MSA, 20 DLB and 131 PD studies. Overall, there is conclusive evidence to suggest sex-and gender-specific manifestation in demographics, biomarkers, genetics, clinical features, interventions, and quality of life in alpha-synucleinopathies. Only limited data exists on the effects of distinct sex hormones, with majority of studies concentrating on estrogen and its speculated neuroprotective effects.

Conclusion

Future studies disentangling the underlying sex-specific mechanisms of alpha-synucleinopathies are urgently needed in order to enable novel sex-specific therapeutics.

Sex and Gender Differences in Parkinson's Disease

The lower prevalence of Parkinson disease (PD) in females is not well understood but may be partially explained by sex differences in nigrostriatal circuitry and possible neuroprotective effects of estrogen. PD motor and nonmotor symptoms differ between sexes, and women experience disparities in care including undertreatment with DBS and less access to caregiving. Our knowledge about PD in gender diverse individuals is limited. Future studies should improve our understanding of the role of hormone replacement therapy in PD, address gender-based inequities in PD care and expand our understanding of PD in SGM and marginalized communities.

Potential Regulation of miRNA-29 and miRNA-9 by Estrogens in Neurodegenerative Disorders: An Insightful Perspective

Finding a link between a hormone and microRNAs (miRNAs) is of great importance since it enables the adjustment of genetic composition or cellular functions without needing gene-level interventions. The dicer-mediated cleavage of precursor miRNAs is an interface link between miRNA and its regulators; any disruption in this process can affect neurogenesis. Besides, the hormonal regulation of miRNAs can occur at the molecular and cellular levels, both directly, through binding to the promoter elements of miRNAs, and indirectly, via regulation of the signaling effects of the post-transcriptional processing proteins. Estrogenic hormones have many roles in regulating miRNAs in the brain. This review discusses miRNAs, their detailed biogenesis, activities, and both the general and estrogen-dependent regulations. Additionally, we highlight the relationship between miR-29, miR-9, and estrogens in the nervous system. Such a relationship could be a possible etiological route for developing various neurodegenerative disorders.

Association Between Menopausal Hormone Therapy and Risk for Parkinson's Disease

BACKGROUND

The relationship between menopausal hormone therapy (MHT) and risk of Parkinson's disease (PD) remains controversial.

OBJECTIVE

This nationwide population-based cohort study investigated the association between MHT and PD development.

METHODS

Data from the National Health Insurance System of South Korea from 2007 to 2020 were used. The MHT group included women who underwent MHT for the first time between 2011-2014, while the non-MHT group included women who visited a healthcare provider for menopause during the same period but never received hormonal therapy. We used propensity score matching (1 : 1) to adjust for potential confounders, and Cox regression models to assess the association between MHT and PD.

RESULTS

We selected 303,260 female participants (n = 151,630 per MHT and non-MHT groups). The median age of the participants was 50 (48-54) years, and the follow-up period lasted 7.9 (6.9-8.9) years. Cox regression analysis revealed an increased risk of PD with MHT (hazard ratio [HR] 1.377, 95% confidence interval [CI] 1.184-1.602), particularly with tibolone (HR 1.554, 95% CI 1.297-1.861) and estrogen alone (HR 1.465, 95% CI 1.054-2.036). Tibolone and estrogen alone were linked to PD within three years; however, no association was observed after three years. In contrast, the use of combined estrogen-progesterone was linked to a higher risk of PD, which increased with the duration of MHT (HR 1.885, 95% CI 1.218-2.918 for over five years).

CONCLUSIONS

This study demonstrated that the MHT is closely associated with the risk of PD in a regimen- and duration-specific manner.

Age Cutoff for Early-Onset Parkinson's Disease: Recommendations from the International Parkinson and Movement Disorder Society Task Force on Early Onset Parkinson's Disease

Background

Early-onset Parkinson's disease (EOPD)/young-onset Parkinson's disease (YOPD) is defined as Parkinson's disease (PD) with an age at onset (AAO) after age 21 years but before the usual AAO for PD. Consensus is lacking, and the reported maximal age for EOPD/YOPD has varied from 40 to 60 years, leading to a lack of uniformity in published studies and difficulty in harmonization of data. EOPD and YOPD have both been used in the literature, somewhat interchangeably.

Objective

To define the nomenclature and AAO cutoff for EOPD/YOPD.

Methods

An extensive review of the literature and task force meetings were conducted. Conclusions were reached by consensus.

Results

First, the literature has seen a shift from the use of YOPD toward EOPD. This seems motivated by an attempt to avoid age-related stigmatization of patients. Second, in defining EOPD, 56% of the countries use 50 or 51 years as the cutoff age. Third, the majority of international genetic studies in PD use an age cutoff of younger than 50 years to define EOPD. Fourth, many studies suggest that changes in the estrogen level can affect the predisposition to develop PD, making the average age at menopause of 50 years an important factor to consider when defining EOPD. Fifth, considering the differential impact of the AAO of PD on professional and social life, using 50 years as the upper cutoff for the definition of EOPD seems reasonable.

Conclusions

This task force recommends the use of EOPD rather than YOPD. It defines EOPD as PD with AAO after 21 years but before 50 years.

Leukocyte telomere length and amyotrophic lateral sclerosis: a Mendelian randomization study

Background

Observational studies have suggested that telomere length is associated with amyotrophic lateral sclerosis (ALS). However, whether this association is causal remains unclear. In this study, we aimed to explore the causal relationship between leukocyte telomere length (LTL) and ALS by a two-sample Mendelian randomization (MR) approach. Single-nucleotide polymorphisms (SNPs) for LTL were identified through high-quality genome-wide association studies (GWASs). The ALS GWAS summary data (20,806 cases; 59,804 controls) with largest sample size to date was obtained. We adopted the inverse variance weighted (IVW) method to examine the effect of LTL on ALS and used the weighted median method, simple median method, MR Egger method and MR-PRESSO method to perform sensitivity analyses.

Results

We found that genetically determined increased LTL was inversely associated with the risk of ALS (odds ratio (OR) = 0.846, 95% confidence interval (CI): 0.744–0.962, P = 0.011), which was mainly driven by rs940209 in the OBFC1 gene, suggesting a potential effect of OBFC1 on ALS. The results were further confirmed by sensitivity analysis with the MR Egger method (OR = 0.647, 95% CI = 0.447–0.936, P = 0.050). Analyses by the weighted median method (OR = 0.893, P = 0.201) and simple median method (OR = 0.935, P = 0.535) also showed a similar trend. The MR Egger analysis did not suggest directional pleiotropy, with an intercept of 0.025 (P = 0.168). Neither the influence of instrumental outliers nor heterogeneity was found.

Conclusions

Our results suggest that genetically predicted increased LTL has a causal relationship with a lower risk of ALS. Protecting against telomere loss may be of great importance in the prevention and treatment of ALS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02135-2.

Effects of the Menstrual Cycle on Neurological Disorders

PURPOSE OF REVIEW

The menstrual cycle involves recurrent fluctuations in hormone levels and temperature via neuroendocrine feedback loops. This paper reviews the impact of the menstrual cycle on several common neurological conditions, including migraine, seizures, multiple sclerosis, stroke, and Parkinson's disease.

RECENT FINDINGS

The ovarian steroid hormones, estrogen and progesterone, have protean effects on central nervous system functioning that can impact the likelihood, severity, and presentation of many neurological diseases. Hormonal therapies have been explored as a potential treatment for many neurological diseases with varying degrees of evidence and success. Neurological conditions also impact women's reproductive health, and the cessation of ovarian function with menopause may also alter the course of neurological diseases. Medication selection must consider hormonal effects on metabolism and the potential for adverse drug reactions related to menstruation, fertility, and pregnancy outcomes. Novel medications with selective affinity for hormonal receptors are desirable. Neurologists and gynecologists must collaborate to provide optimal care for women with neurological disorders.

A Report of Tamoxifen and Parkinson's Disease in a US Population and a Review of the Literature

BACKGROUND

Tamoxifen, a selective estrogen receptor modulator, has been shown to variably affect Parkinson's disease (PD) risk.

OBJECTIVE

The aim of this study was to review epidemiological literature and evaluate the rate of PD in women with breast cancer with tamoxifen exposure in a US population.

METHODS

A literature search was conducted to identify relevant studies. We performed a retrospective cohort analysis using the Nurses' Health Study Version One to report descriptive statistics.

RESULTS

Most studies suggest there may be a time-dependent effect of tamoxifen on PD risk, with the risk increasing with time from exposure. However, rates of PD in persons exposed to tamoxifen overall appear to be low. In our cohort, PD was evident in 6.2 per 1,000 of those with tamoxifen use and 3.6 per 1,000 of those without tamoxifen use. Time from breast cancer to PD diagnosis was 9.7 years among women with tamoxifen exposure and 11.7 among women without.

CONCLUSIONS

Tamoxifen may be associated with an increased risk for PD. Further research is needed to elucidate the role of estrogen and selective estrogen antagonism in PD. © 2021 International Parkinson and Movement Disorder Society.

Gender Differences and Quality of Life in Parkinson's Disease

Parkinson's disease has been found to significantly affect health-related quality of life. The gender differences of the health-related quality of life of subjects with Parkinson's disease have been observed in a number of studies. These differences have been reported in terms of the age at onset, clinical manifestations, and response to therapy. In general, women with Parkinson's disease showed more positive disease outcomes with regard to emotion processing, non-motor symptoms, and cognitive functions, although women report more Parkinson's disease-related clinical manifestations. Female gender predicted poor physical functioning and socioemotional health-related quality of life, while male gender predicted the cognitive domain of health-related quality of life. Some studies reported gender differences in the association between health-related quality of life and non-motor symptoms. Depression and fatigue were the main causes of poorer health-related quality of life in women, even in the early stages of Parkinson's disease. The aim of this review was to collect the best available evidence on gender differences in the development of Parkinson's disease symptoms and health-related quality of life.

Repurposing sex steroids and related drugs as potential treatment for Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder for which a greater prevalence and incidence is described in men. This suggests a protective effect of sex hormones in the brain. Therefore, steroids and drugs to treat endocrine conditions could have additional application for PD. Here, we review the protective effect of sex hormones, particularly estrogens, progesterone, androgens and dehydroepiandrosterone, in animal models of PD and also in human studies. Data also support that drugs affecting estrogen neurotransmission such as selective estrogen receptor modulators or affecting steroid metabolism with 5α-reductase inhibitors could be repositioned for treatment of PD. Sex steroids are also modulator of neurotransmission, thus they could repurposed to treat PD motor symptoms and to modulate the response to PD medication. No drug is yet available to limit PD progression. PD is a complex disease implicating multiple pathological processes and a therapeutic strategy using drugs with several mechanisms of action, such as sex steroids and endocrine drugs are interesting repositioning options for symptomatic treatment and disease-modifying activity for PD. This article is part of the Special Issue entitled 'Drug Repurposing: old molecules, new ways to fast track drug discovery and development for CNS disorders'.

Influence of Estrogen Modulation on Glia Activation in a Murine Model of Parkinson's Disease

Epidemiological data suggest a sexual dimorphism in Parkinson disease (PD), with women showing lower risk of developing PD. Vulnerability of the nigrostriatal pathway may be influenced by exposure to estrogenic stimulation throughout fertile life. To further address this issue, we analyzed the progression of nigrostriatal damage, microglia and astrocyte activation and microglia polarization triggered by intrastriatal injection of dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) in male, female and ovariectomized (OVX) mice, as well as in OVX mice supplemented with 17βestradiol (OVX+E). Animals were sacrificed at different time points following 6-OHDA injection and brain sections containing striatum and substantia nigra pars compacta (SNc) underwent immunohistochemistry for tyrosine hydroxylase (TH) (dopaminergic marker), immunofluorescence for IBA1 and GFAP (markers of microglia and astrocyte activation, respectively) and triple immunoflorescent to identify polarization of microglia toward the cytotoxic M1 (DAPI/IBA1/TNFα) or cytoprotective M2 (DAPI/IBA1/CD206) phenotype. SNc damage induced by 6-OHDA was significantly higher in OVX mice, as compared to all other experimental groups, at 7 and 14 days after surgery. Astrocyte activation was higher in OVX mice with respect the other experimental groups, at all time points. Microglial activation in the SNc was detected at earlier time points in male, female and OVX+E, while in OVX mice was detected at all time-points. Microglia polarization toward the M2, but not the M1, phenotype was detected in female and OVX+E mice, while the M1 phenotype was observed only in male and OVX mice. Our results support the protective effects of estrogens against nigrostriatal degeneration, suggesting that such effects may be mediated by an interaction with microglia, which tend to polarize preferentially toward an M2, cytoprotective phenotype in the presence of intense estrogenic stimulation.

Association Analysis of Proteasome Subunits and Transporter Associated with Antigen Processing on Chinese Patients with Parkinson's Disease

Background:

Proteasome subunits (PSMB) and transporter associated with antigen processing (TAP) loci are located in the human leukocyte antigen (HLA) Class II region play important roles in immune response and protein degradation in neurodegenerative diseases. This study aimed to explore the association between single nucleotide polymorphisms (SNPs) of PSMB and TAP and Parkinson's disease (PD).

Methods:

A case–control study was conducted by genotyping SNPs in PSMB8, PSMB9, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMB9, TAP1, and TAP2 were genotyped through SNaPshot testing.

Results:

The stratified analysis of rs17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rs17587-G/G versus (A/A + G/A) compared with controls. But there was no significant difference with respect to the genotypic frequencies of the SNPs in PSMB8, TAP1, and TAP2 loci in PD patients.

Conclusion:

Chinese females carrying the rs17587-G/G genotype in PSMB9 may increase a higher risk for PD, but no linkage was found between other SNPs in HLA Class II region and PD.

Impact of Sex on the Nonmotor Symptoms and the Health-Related Quality of Life in Parkinson's Disease

Background. Female Parkinson's disease (PD) patients seem to experience not only more severe motor complications and postural instability but also more pronounced depression, anxiety, pain, and sleep disturbances. Objective. The aim of the present study was to evaluate the role of sex as a possible independent predictor of HRQoL in PD. Methods. In this cross-sectional study, 621 consecutive patients treated at the University of Pécs were enrolled. Severity of PD symptoms was assessed by MDS-UPDRS, UDysRS, Non-Motor Symptoms Scale, PDSS-2, Hamilton Anxiety Scale, Montgomery-Asberg Depression Rating Scale, Lille Apathy Rating Scale, and Addenbrooke Cognitive Examination. HRQoL was assessed by PDQ-39 and EQ-5D. Multiple regression analysis was performed to estimate the PDQ-39 and EQ-5D index values based on various clinical factors. Results. Although females received significantly lower dosage of levodopa, they had significantly more disabling dyskinesia and worse postural instability. Anxiety, pain, sleep disturbances, and orthostatic symptoms were more frequent among females while sexual dysfunction, apathy, and daytime sleepiness were more severe among males. Women had worse HRQoL than men (EQ-5D index value: 0.620 ± 0.240 versus 0.663 ± 0.229, p = 0.025, and PDQ-39 SI: 27.1 ± 17.0 versus 23.5 ± 15.9, p = 0.010). Based on multiple regression analysis, sex was an independent predictor for HRQoL in PD. Conclusions. Based on our results, female sex is an independent predictor for having worse HRQoL in PD.

Inhibition of Rho-kinase by Fasudil protects dopamine neurons and attenuates inflammatory response in an intranasal lipopolysaccharide-mediated Parkinson's model

Microglia activation and inflammatory factors in brain microenvironment are associated with degeneration of neurons in the substantia nigra (SN) of Parkinson's disease (PD) patients and various PD models. There is increasing evidence that the Rho/ROCK (Rho kinase) signalling pathway may play a critical role in the inflammatory response, and ROCK inhibitor has been reported to have neuroprotective effects. In this study, we examined the neuroprotective potential and possible mechanism of ROCK inhibitor Fasudil in an intranasal lipopolysaccharide (LPS)-induced PD model. ROCK was activated with LPS stimulation and inhibited by Fasudil treatment in this PD model. Behavioural tests demonstrated a clear improvement in motor performance after Fasudil treatment. Furthermore, Fasudil resulted in a significant attenuation of dopamine cell loss, α-synuclein accumulation and inflammatory response with the reversion of inflammatory M1 to anti-inflammatory M2 microglia, decreased NF-кB activation, and IL-12 and TNF-α generation in the SN and olfactory bulb in this model. This study establishes a role for Fasudil in protecting against LPS-mediated dopamine degeneration and provides a therapeutic strategy for the treatment of PD.

Neuroactive gonadal drugs for neuroprotection in male and female models of Parkinson's disease

The existence of sex differences in Parkinson's disease (PD) incidence is well documented with greater prevalence and earlier age at onset in men than in women. These reported sex differences could be related to estrogen exposure. In PD animal models, estrogen is well documented to be neuroprotective against dopaminergic neuron loss induced by neurotoxins. Using the 1-methyl 4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) mouse model, we showed that several compounds are neuroprotective on dopaminergic neurons including estrogen, the selective estrogen receptor modulator raloxifene, progesterone, dehydroepiandrosterone, the estrogen receptor alpha (ERα) agonist PPT as well as the G protein-coupled membrane estrogen receptor (GPER1) specific agonist G1. Accumulating evidence suggests that GPER1 could be implicated in the neuroprotective effects of estrogen, raloxifene and G1 in collaboration with ERα. We recently reported that the 5α-reductase inhibitor Dutasteride is also neuroprotective and could bring an alternative to estrogens for therapy in male. Additional studies are needed to optimize therapies with these gonadal drugs into safe personalized treatments according to sex for treatment of PD.

Hormone replacement therapy and Parkinson's disease risk in women: a meta-analysis of 14 observational studies

BACKGROUND AND PURPOSE

Published data on the relationship of hormone replacement therapy (HRT) with Parkinson's disease (PD) were inconclusive. Thus, a systematic meta-analysis of observational studies was performed to clarify this topic.

METHODS

The databases of PubMed and EMBASE were searched for case-control or cohort studies published up till June 2, 2014. Meta-analysis of the relative risks (RRs) with 95% confidence intervals (CIs) was estimated using random-effects models.

RESULTS

A final total of ten case-control and four cohort studies were included in our meta-analysis. The overall combined RR of PD for ever users versus never users of HRT was 1.00 (95% CI: 0.84-1.20). Limited to those subjects who only use estrogen, a similar trend was detected (RR: 0.95, 95% CI: 0.69-1.30). In the subgroup analysis by study design, no significant association was observed in case-control studies (RR: 0.79, 95% CI: 0.62-1.02), whereas a positive association was found in cohort studies (RR: 1.24, 95% CI: 1.10-1.40). In further analysis according to study quality, an inverse association was found in the low-quality group (RR: 0.58, 95% CI: 0.40-0.82), whereas a positive association was found in the high-quality group (RR: 1.16, 95% CI: 1.02-1.31).

CONCLUSION

In summary, our results of meta-analysis do not support a protective role of HRT in female PD development.

No sex differences in use of dopaminergic medication in early Parkinson disease in the US and Canada - baseline findings of a multicenter trial

Background

Sex differences in Parkinson disease clinical features have been reported, but few studies have examined sex influences on use of dopaminergic medication in early Parkinson disease. The objective of this study was to test if there are differences in the type of dopaminergic medication used and levodopa equivalent daily dose between men and women with early Parkinson disease enrolled in a large multicenter study of Creatine as a potential disease modifying therapy – the National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson Disease Long-Term Study-1.

Methods

Baseline data of 1,741 participants from 45 participating sites were analyzed. Participants from the United States and Canada were enrolled within five years of Parkinson Disease diagnosis. Two outcome variables were studied: type of dopaminergic medication used and levodopa equivalent daily dose at baseline in the Long-Term Study-1. Chi-square statistic and linear regression models were used for statistical analysis.

Results

There were no statistically significant differences in the frequency of use of different types of dopaminergic medications at baseline between men and women with Parkinson Disease. A small but statistically significant difference was observed in the median unadjusted levodopa equivalent daily dose at baseline between women (300 mg) and men (325 mg), but this was not observed after controlling for disease duration (years since Parkinson disease diagnosis), disease severity (Unified Parkinson's Disease Rating Scale Motor and Activities of Daily Living Scores), and body weight.

Conclusions

In this large multicenter study, we did not observe sex differences in the type and dose of dopaminergic medications used in early Parkinson Disease. Further research is needed to evaluate the influence of male or female sex on use of dopaminergic medication in mid- and late-stage Parkinson Disease.

Sex differences in Parkinson's disease and other movement disorders

Movement disorders including Parkinson's disease (PD), Huntington's disease (HD), chorea, tics, and Tourette's syndrome (TS) display sex differences in disease susceptibility, disease pathogenesis, and clinical presentation. PD is more common in males than in females. Epidemiologic studies suggest that exposure to endogenous and exogenous estrogen contributes to these sex differences. There is extensive evidence that estrogen prevents dopaminergic neuron depletion induced by neurotoxins in PD animal models and therefore is neuroprotective. Estrogen may also decrease the efficacy of other neuroprotective substances such as caffeine in females but not males. Sex chromosomes can exert effects independent of sex steroid hormones on the development and maintenance of the dopamine system. As a result of hormone, chromosome and other unknown effects, there are sexual dimorphisms in the basal ganglia, and at the molecular levels in dopaminergic neurons that may lead to distinct mechanisms of pathogenesis in males and females. In this review, we summarize the evidence that estrogen and selective estrogen receptor modulators are neuroprotective in PD and discuss potential mechanisms of action. We also briefly review how sex differences in basal ganglia function and dopaminergic pathways may impact HD, chorea, and tics/Tourette's syndrome. Further understanding of these sex differences may lead to novel therapeutic strategies for prevention and treatment of these diseases.

Female reproductive factors, menopausal hormone use, and Parkinson's disease

The objective of this study was to examine the associations of reproductive factors and exogenous hormone use with risk of Parkinson's disease (PD) among postmenopausal women. The study comprised 119,166 postmenopausal women aged 50 to 71 years in the NIH-AARP Diet and Health Study, who completed a baseline questionnaire in 1995-1996 and a follow-up survey in 2004-2006. A total of 410 self-reported PD diagnoses were identified between 1995 and 2006. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were derived from logistic regression models. PD risk was not significantly associated with female reproductive factors including age at menarche, age at first live birth, parity, and age at menopause. For example, compared with women with natural menopause at age 50 to 54 years, the ORs were 1.18, (95% CI, 0.78-1.79) for women with natural menopause aged <45, 1.19 (95% CI, 0.88-1.61) for those aged 45 to 49, and 1.33 (95% CI, 0.91-1.93) for those aged 55 or older. We found that oral contraceptive use for ≥10 years (vs. never used) was associated with lower PD risk (OR, 0.59; 95% CI, 0.38-0.92), but shorter use showed no association. Use of menopausal hormone therapy showed inconsistent results. Compared with non-hormone users at baseline, current hormone users for <5 years showed a higher risk of PD (OR, 1.52; 95% CI, 1.11-2.08). However, no associations were observed for past hormone users or current users of ≥5 years. Overall, this large prospective study provides little support for an association between female reproductive factors and PD risk. Our findings on long-term oral contraceptive use and current hormone therapy warrant further investigations.

Perimenopause Amelioration of a TCM Recipe Composed of Radix Astragali, Radix Angelicae Sinensis, and Folium Epimedii: An In Vivo Study on Natural Aging Rat Model

Traditional Chinese medicine (TCM) has been extensively applied as preferable herbal remedy for menopausal symptoms. In the present work, the potential of a TCM recipe named RRF, composed of Radix Astragali, Radix Angelicae Sinensis, and Folium Epimedii, was investigated on a natural aging rat model. After administration of RRF (141, 282, and 564 mg/kg/d), the circulated estradiol (E2) level increased accompanied by a reduction of serum follicle stimulating hormone (FSH). But no significant impact on serum lutenizing hormone (LH) level was observed. As a result of the E2-FSH-LH adjustment, the histomorphology degenerations of ovary, uterus, and vagina of the 11.5-month female rats were alleviated. And lumbar vertebrae trabecular microstructure was also restored under RRF exposure by means of increasing the trabecular area and area rate. Moreover, levels of hypothalamic dopamine (DA) and norepinephrine (NE) rallied significantly after RRF treatment. Results from our studies suggest that RRF possesses a positive regulation on the estrogen imbalance and neurotransmitter disorder, thereby restoring reproductive organ degeneration and skeleton deterioration. The above-mentioned benefits of RRF on the menopause syndromes recommend RRF as a potential candidate for the treatment of perimenopausal syndrome.

Hormone therapy for sexual function in perimenopausal and postmenopausal women

BACKGROUND

The perimenopausal and postmenopausal periods are associated with many symptoms, including sexual complaints.

OBJECTIVES

To assess the effect of hormone therapy (HT) on sexual function in perimenopausal and postmenopausal women.

SEARCH METHODS

We searched for articles in the Cochrane Menstrual Disorders and Subfertility Group (MDSG) Specialised Register, CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS, ClinicalTrials.gov, Current Controlled Trials, WHO International Clinical Trials Registry Platform, ISI Web of Knowledge and OpenGrey. The last search was performed in December 2012.

SELECTION CRITERIA

We included randomised controlled trials comparing HT to either placebo or no intervention (control). We considered as HT estrogens alone; estrogens in combination with progestogens; synthetic steroids (for example tibolone); or selective estrogen receptor modulators (SERMs) (for example raloxifene, bazedoxifene). Studies of other drugs possibly used in the relief of menopausal symptoms were excluded. We included studies that evaluated sexual function using any validated assessment tool. The primary outcome was a composite score for sexual function and the scores for individual domains (arousal and sexual interest, orgasm, and pain) were secondary outcomes. Studies were selected by two authors independently.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two authors and checked by a third. Risk of bias assessment was performed independently by two authors. We contacted study investigators as required. Data were analysed using standardized mean difference (SMD) and relative risk (RR). We stratified the analysis by participant characteristics with regard to menopausal symptoms. The overall quality of the evidence for the primary outcome was evaluated using the GRADE criteria.

MAIN RESULTS

The search retrieved 2351 records from which 27 studies (16,393 women) were included. The 'symptomatic or early post-menopausal' subgroup included nine studies: perimenopausal women (one study), up to 36 months postmenopause (one study), up to five years postmenopause (one study), experiencing vasomotor or other menopausal symptoms (five studies), or experiencing hot flushes and sexual dysfunction (one study). The 'unselected postmenopausal women' subgroup included 18 studies, which included women regardless of menopausal symptoms and permitted the inclusion of women with more than five years since the final menstrual period. No studies were restricted to women with sexual dysfunction. Only five studies evaluated sexual function as a primary outcome. Eighteen studies were deemed at high risk of bias, and the other nine studies were at unclear risk of bias. Twenty studies received commercial funding.Findings for sexual function (measured by composite score):For estrogens alone versus control, in symptomatic or early postmenopausal women the SMD and 95% CI were compatible with a small to moderate benefit in sexual function for the HT group (SMD 0.38, 95% CI 0.23 to 0.54, P < 0.00001, 3 studies, 699 women, I² = 55%, high-quality evidence). In unselected postmenopausal women, the 95% CI was compatible with no effect to a small benefit (SMD 0.16, 95% CI -0.02 to 0.34, P = 0.08, 2 studies, 478 women, I² = 44%, low-quality evidence). The subgroups were not pooled because of considerable heterogeneity.For estrogens combined with progestogens versus control, in symptomatic or early postmenopausal women the 95% CI was compatible with a small to moderate benefit for sexual function in the HT group (SMD 0.42, 95% CI 0.19 to 0.64, P = 0.0003, 1 study, 335 women, moderate-quality evidence). In unselected postmenopausal women, the 95% CI was compatible with no effect to a small benefit (SMD 0.09, 95% CI -0.02 to 0.20, P = 0.10, 3 studies, 1314 women, I² = 0%, moderate-quality evidence). The subgroups were not pooled because of considerable heterogeneity.For tibolone versus control, in symptomatic or early postmenopausal women the 95% CI was compatible with no effect to a small benefit for sexual function in the HT group (SMD 0.13, 95% CI 0.00 to 0.26, P = 0.05, 1 study, 883 women, low-quality evidence). In unselected postmenopausal women, the 95% CI was compatible with no effect to a moderate benefit (SMD 0.38, 95% CI 0.04 to 0.71, P = 0.03, 2 studies, 142 women, I² = 0%, low-quality evidence). In the combined analysis, the 95% CI was compatible with no effect to a small benefit (SMD 0.17, 95% CI 0.04 to 0.29, P = 0.008, 3 studies, 1025 women, I² = 20%).For SERMs versus control, in symptomatic or early postmenopausal women the 95% CI was compatible with no effect to a moderate benefit for sexual function in the HT group (SMD 0.23, 95% CI -0.04 to 0.50, P = 0.09, 1 study, 215 women, low-quality evidence). In unselected postmenopausal women, the 95% CI was compatible with small harm to a small benefit (SMD 0.04, 95% CI -0.20 to 0.29, P = 0.72, 1 study, 283 women, low-quality evidence). In the combined analysis, the 95% CI was compatible with no effect to a small benefit (SMD 0.13, 95% CI -0.05 to 0.31, P = 0.16, 2 studies, 498 women, I² = 2%).A comparison of SERMs combined with estrogens versus control was only evaluated in symptomatic or early postmenopausal women. The 95% CI was compatible with no effect to a small benefit for sexual function in the HT group (SMD 0.21, 95% CI 0.00 to 0.43, P = 0.05, 1 study, 542 women, moderate-quality evidence).

AUTHORS' CONCLUSIONS

HT treatment with estrogens alone or in combination with progestogens was associated with a small to moderate improvement in sexual function, particularly in pain, when used in women with menopausal symptoms or in early postmenopause (within five years of amenorrhoea), but not in unselected postmenopausal women. Evidence regarding other HTs (synthetic steroids and SERMs) is of low quality and we are uncertain of their effect on sexual function. The current evidence does not suggest an important effect of tibolone or of SERMs alone or combined with estrogens on sexual function. More studies evaluating the effect of synthetic steroids, SERMS and the association of SERM + estrogens would improve the quality of the evidence for the effect of these treatments on sexual function in peri and postmenopausal women. Future studies should also evaluate the effect of HT solely among women with sexual complaints.

Estrogen synthesis and signaling pathways during aging: from periphery to brain

Estrogens are the primary female sex hormones and play important roles in both reproductive and non-reproductive systems. Estrogens can be synthesized in non-reproductive tissues such as liver, heart, muscle, bone and brain, and tissue-specific estrogen synthesis is consistent with a diversity of estrogen actions. In this article we review tissue and cell-specific estrogen synthesis and estrogen receptor signaling in three parts: (i) synthesis and metabolism, (ii) the distribution of estrogen receptors and signaling, and (iii) estrogen functions and related disorders, including cardiovascular diseases, osteoporosis, Alzheimer's disease (AD), and Parkinson disease (PD). This comprehensive review provides new insights into estrogens by giving a better understanding of the tissue-specific estrogen effects and their roles in various diseases.

Hormone replacement therapy and risk for neurodegenerative diseases

Over the past two decades, there has been a significant amount of research investigating the risks and benefits of hormone replacement therapy (HRT) with regards to neurodegenerative disease. Here, we review basic science studies, randomized clinical trials, and epidemiological studies, and discuss the putative neuroprotective effects of HRT in the context of Alzheimer's disease, Parkinson's disease, frontotemporal dementia, and HIV-associated neurocognitive disorder. Findings to date suggest a reduced risk of Alzheimer's disease and improved cognitive functioning of postmenopausal women who use 17β-estradiol. With regards to Parkinson's disease, there is consistent evidence from basic science studies for a neuroprotective effect of 17β-estradiol; however, results of clinical and epidemiological studies are inconclusive at this time, and there is a paucity of research examining the association between HRT and Parkinson's-related neurocognitive impairment. Even less understood are the effects of HRT on risk for frontotemporal dementia and HIV-associated neurocognitive disorder. Limits to the existing research are discussed, along with proposed future directions for the investigation of HRT and neurodegenerative diseases.