Parkinson's Disease in Women and Men: What's the Difference?

Treatment initiation for parkinson’s disease in Australia 2013–2018: a nation-wide study

Background

Guidelines highlight the importance of an individualized approach to treatment initiation for Parkinson’s disease. Our aim was to investigate initiation of anti-Parkinson medication in Australia from 2013–2018, and to determine factors predicting choice of initial treatment.

Methods

Cohort of new-users (N = 4,887) of anti-Parkinson medication aged ≥ 40 years were identified from a 10% random representative sample of national medication dispensing data from July-2013 to June-2018. Changes in treatment initiation were examined across the whole cohort and stratified by age and sex.

Results

Treatment initiation was most frequent with levodopa followed by non-ergot dopamine agonists (DAs) and anticholinergics. Two thirds initiated with levodopa across the study period. Initiation with non-ergot DAs increased from 22 to 27% (rate ratio, RR 1.23, 95% confidence interval, CI 1.02–1.47) and initiation with anticholinergics decreased from 6.9% to 2.4% (RR 0.34, 95% CI 0.21–0.55) from 2013–2018. Among persons aged ≥ 65 years, one third of women and one fourth of men initiated on levodopa. Among women aged < 65 years, rates of treatment initiation with DAs (37%) and levodopa (37%) were similar in 2013/2014 but initiation with DA exceeded levodopa thereafter. Among men aged < 65 years, treatment initiation with levodopa (44%-49%) remained more frequent than initiation with DAs (29%-32%) throughout the study period.

Conclusions

Treatment initiation with levodopa was most frequent among persons aged ≥ 65 years, consistent with current guidelines. Whilst the value of levodopa sparing strategies is unclear, treatment initiation with DA has become increasingly common relative to levodopa among women but not among men aged < 65 years.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03095-3.

The role of Tumour Necrosis Factor in neuroinflammation associated with Parkinson's disease and targeted therapies

Neurodegenerative disorders Parkinson's disease is a progressive neurodegenerative disorder associated with neuroinflammatory responses that lead to the neurodegeneration of the dopaminergic neurons. These neuroinflammatory mechanisms involve various cytokines produced by the activated glial cells. Tumour Necrosis factor α (TNF α) is one of the major mediators of the neuroinflammation associated with neurodegeneration. TNF α has a dual role of neuroprotection and neurotoxicity in the brain. The effective pathways of TNF involve various signalling pathways transduced by the receptors TNFR1 and TNFR2. Effective therapeutic strategies have been produced targeting the neurotoxic behaviour of the Tumour Necrosis Factor and the associated neurodegeneration which includes the use of Dominant Negative Tumour Necrosis Factor (DN-TNF) inhibitors like XENP 345 and XPro®1595 and peroxisome proliferator receptor gamma (PPAR-γ) agonists.

Myeloperoxidase and Advanced Oxidation Protein Products in the Cerebrospinal Fluid in Women and Men with Parkinson's Disease

Background: Myeloperoxidase (MPO) and advanced oxidation protein products, or AOPP (a type of MPO-derived chlorinated adducts), have been implicated in Parkinson´s disease (PD). Human MPO also show sex-based differences in PD. The objective was to study the relationship of MPO and AOPP in the cerebrospinal fluid (CSF) with motor features of idiopathic PD in male and female patients. Methods: MPO concentration and activity and AOPP content were measured in the CSF and serum in 34 patients and 30 controls. CSF leukocytes and the integrity of the blood-brain barrier were evaluated. Correlations of MPO and AOPP with clinical variables were examined. Results: The blood-brain barrier was intact and CSF leukocyte count was normal in all patients. CSF MPO concentration and activity were similar in the cohort of patients and controls, but CSF MPO content was significantly higher in male patients than in PD women (p = 0.0084). CSF MPO concentration correlated with disease duration in male and female patients (p < 0.01). CSF MPO concentration was significantly higher in men with disease duration ≥12 years versus the remainder of the male subjects (p < 0.01). Changes in CSF MPO in women were not significant. Serum MPO concentration and activity were significantly higher in all PD patients relative to controls (p < 0.0001). CSF MPO was not correlated with serum MPO. Serum AOPP were detected in all patients, but CSF AOPP was undetectable in 53% of patients. AOPP were not quantifiable in controls. Conclusions: CSF MPO is not a good biomarker for PD because mean CSF MPO concentration and activity are not different between the cohort of patients and controls. CSF MPO concentration positively correlated with disease duration in men and women, but CSF MPO is significantly enhanced only in male patients with disease duration longer than 12 years. It can be hypothesized that the MPO-related immune response in early-stage PD might be weak in all patients, but then the MPO-related immune response is progressively enhanced in men, not women. Since the blood-brain barrier is intact, and CSF MPO is not correlated with serum MPO, CSF myeloperoxidase would reflect MPO content in brain cells, not blood-derived cells. Finally, serum AOPP was detected in all patients, but not controls, which is consistent with the occurrence of chlorinative stress in blood serum in PD. The study of CSF AOPP as biomarker could not be assessed because the ELISA assay was hampered by its detection limit in the CSF.

Alterations in Self-Aggregating Neuropeptides in Cerebrospinal Fluid of Patients with Parkinsonian Disorders

Background: Parkinson’s disease (PD), progressive supranuclear palsy (PSP), and multiple system atrophy (MSA) present with similar movement disorder symptoms but distinct protein aggregates upon pathological examination. Objective: Discovery and validation of candidate biomarkers in parkinsonian disorders for differential diagnosis of subgroup molecular etiologies. Methods: Untargeted liquid chromatography (LC)-mass spectrometry (MS) proteomics was used for discovery profiling in cerebral spinal fluid (CSF) followed by LC-MS/MS based multiple reaction monitoring for validation of candidates. We compared clinical variation within the parkinsonian cohort including PD subgroups exhibiting tremor dominance (TD) or postural instability gait disturbance and those with detectable leukocytes in CSF. Results: We have identified candidate peptide biomarkers and validated related proteins with targeted quantitative multiplexed assays. Dopamine-drug naïve patients at first diagnosis exhibit reduced levels of signaling neuropeptides, chaperones, and processing proteases for packaging of self-aggregating peptides into dense core vesicles. Distinct patterns of biomarkers were detected in the parkinsonian disorders but were not robust enough to offer a differential diagnosis. Different biomarker changes were detected in male and female patients with PD. Subgroup specific candidate biomarkers were identified for TD PD and PD patients with leukocytes detected in CSF. Conclusion: PD, MSA, and PSP exhibit overlapping as well as distinct protein biomarkers that suggest specific molecular etiologies. This indicates common sensitivity of certain populations of selectively vulnerable neurons in the brain, and distinct therapeutic targets for PD subgroups. Our report validates a decrease in CSF levels of self-aggregating neuropeptides in parkinsonian disorders and supports the role of native amyloidogenic proteins in etiologies of neurodegenerative diseases.

Baseline Differences in Long-term Survivors and Nonsurvivors of the Colorado/Columbia Fetal Implant Trial

OBJECTIVE

This study is based on long-term follow-up of participants in a randomized double-blind sham surgery-controlled trial (1995-1999) designed to determine the effectiveness of implantation of human embryonic mesencephalic tissue containing dopamine neuron precursors into the brains of patients with advanced Parkinson's disease (PD). We investigated differences between long-term survivors and nonsurvivors at baseline in order to contribute to information regarding optimal patient selection for upcoming stem cell trials.

METHOD

Forty participants were randomly assigned to receive either neural implantation or sham surgery. Thirty-four patients who ultimately received the implant were followed periodically with the most recent assessment occurring in 2015-2016. Demographic information, neurological measures, positron emission tomography (PET) imaging, neuropsychological assessments, and a personality assessment were included in the current analyses. T-tests were used to compare survivors and nonsurvivors. Logistic regression analyses examined predictors of survivorship.

RESULTS

Five of six survivors were female. They were younger than nonsurvivors (p = .03) and more neuropsychologically "intact" across a broad range of cognitive areas (significance levels ranged from <.001 to .045). There were no differences between survivors and nonsurvivors off medications at baseline on neurological or PET assessments. Survivors reported more "Openness to Experience" (p = .004) than nonsurvivors. Using empirically derived predictor variables, results of logistic regression analyses indicated that Animal Naming (cognitive task) and Openness to Experience (personality variable) were the strongest predictors of survivorship.

CONCLUSIONS

Variables to consider when selecting participants for future cell-based therapies include being "intact" neuropsychologically, level of Openness to Experience, younger age, and inclusion of women.

Demystifying the Neuroprotective Role of Neuropeptides in Parkinson's Disease: A Newfangled and Eloquent Therapeutic Perspective

Parkinson's disease (PD) refers to one of the eminently grievous, preponderant, tortuous nerve-cell-devastating ailments that markedly impacts the dopaminergic (DArgic) nerve cells of the midbrain region, namely the substantia nigra pars compacta (SN-PC). Even though the exact etiopathology of the ailment is yet indefinite, the existing corroborations have suggested that aging, genetic predisposition, and environmental toxins tremendously influence the PD advancement. Additionally, pathophysiological mechanisms entailed in PD advancement encompass the clumping of α-synuclein inside the lewy bodies (LBs) and lewy neurites, oxidative stress, apoptosis, neuronal-inflammation, and abnormalities in the operation of mitochondria, autophagy lysosomal pathway (ALP), and ubiquitin-proteasome system (UPS). The ongoing therapeutic approaches can merely mitigate the PD-associated manifestations, but until now, no therapeutic candidate has been depicted to fully arrest the disease advancement. Neuropeptides (NPs) are little, protein-comprehending additional messenger substances that are typically produced and liberated by nerve cells within the entire nervous system. Numerous NPs, for instance, substance P (SP), ghrelin, neuropeptide Y (NPY), neurotensin, pituitary adenylate cyclase-activating polypeptide (PACAP), nesfatin-1, and somatostatin, have been displayed to exhibit consequential neuroprotection in both in vivo and in vitro PD models via suppressing apoptosis, cytotoxicity, oxidative stress, inflammation, autophagy, neuronal toxicity, microglia stimulation, attenuating disease-associated manifestations, and stimulating chondriosomal bioenergetics. The current scrutiny is an effort to illuminate the neuroprotective action of NPs in various PD-experiencing models. The authors carried out a methodical inspection of the published work procured through reputable online portals like PubMed, MEDLINE, EMBASE, and Frontier, by employing specific keywords in the subject of our article. Additionally, the manuscript concentrates on representing the pathways concerned in bringing neuroprotective action of NPs in PD. In sum, NPs exert substantial neuroprotection through regulating paramount pathways indulged in PD advancement, and consequently, might be a newfangled and eloquent perspective in PD therapy.

Neuroglial Senescence, α-Synucleinopathy, and the Therapeutic Potential of Senolytics in Parkinson’s Disease

Parkinson’s disease (PD) is the most common movement disorder and the second most prevalent neurodegenerative disease after Alzheimer’s disease. Despite decades of research, there is still no cure for PD and the complicated intricacies of the pathology are still being worked out. Much of the research on PD has focused on neurons, since the disease is characterized by neurodegeneration. However, neuroglia has become recognized as key players in the health and disease of the central nervous system. This review provides a current perspective on the interactive roles that α-synuclein and neuroglial senescence have in PD. The self-amplifying and cyclical nature of oxidative stress, neuroinflammation, α-synucleinopathy, neuroglial senescence, neuroglial chronic activation and neurodegeneration will be discussed. Finally, the compelling role that senolytics could play as a therapeutic avenue for PD is explored and encouraged.

Contributions and Limitations of Mitochondria-Targeted and Non-Targeted Antioxidants in the Treatment of Parkinsonism: an Updated Review

As conventional therapeutics can only treat the symptoms of Parkinson's disease (PD), major focus of research in recent times is to slow down or prevent the progression of neuronal degeneration in PD. Non-targeted antioxidants have been an integral part of the conventional therapeutics regimen; however, their importance have lessened over time because of their controversial outcomes in clinical PD trials. Inability to permeate and localize within the mitochondria remains the main drawback on the part of non-targeted antioxidants inspite of possessing free radical scavenging properties. In contrast, mitochondrial-targeted antioxidants (MTAs), a special class of compounds have emerged having high advantages over non-targeted antioxidants by virtue of efficient pharmacokinetics and better absorption rate with capability to localize many fold inside the mitochondrial matrix. Preclinical experimentations indicate that MTAs have the potential to act as better alternatives compared to conventional non-targeted antioxidants in treating PD; however, sufficient clinical trials have not been conducted to investigate the efficacies of MTAs in treating PD. Controversial clinical outcomes on the part of non-targeted antioxidants and lack of clinical trials involving MTAs have made it difficult to go ahead with a direct comparison and in turn have slowed down the progress of development of safer and better alternate strategies in treating PD. This review provides an insight on the roles MTAs and non-targeted antioxidants have played in the treatment of PD till date in preclinical and clinical settings and discusses about the limitations of mitochondria-targeted and non-targeted antioxidants that can be resolved for developing effective strategies in treating Parkinsonism.

Gender differences in progressive supranuclear palsy

The gender differences in progressive supranuclear palsy (PSP) are not extensively studied. The objective of this study was to determine the gender differences in the phenotypic expression and progression in PSP. We did a retrospective review of medical records of patients diagnosed with PSP over a 21-year period. The interval between disease onset and attainment of the five clinical disability milestones namely wheel chair dependency, unintelligible speech, severe dysphagia, severe cognitive impairment and urinary catheterization was used to determine the progression. Data was analysed from the case records of 334 patients with PSP. 209 patients (62.2%) were male and 125 (37.4%) among the patients were women (male:female ratio = 1.6:1). Males had older age at onset with longer duration of illness at time of presentation. Tremors were more common, PSP-P phenotype was more frequent and time to attain wheelchair dependency was earlier in males. Falls within 1 year of disease onset, apathy and executive dysfunction were more frequent and time to attain unintelligible speech, severe dysphagia and cognitive impairment were earlier in females. This study in a large cohort of clinically diagnosed cases of PSP has showed that gender differences exist in PSP in terms of clinical characteristics, progression of the disease.

Aromatase inhibitors and the incidence of Parkinson disease: A population-based cohort study

BACKGROUND

Current guidelines recommend the treatment of hormone receptor-positive breast cancer with aromatase inhibitors (AIs) and tamoxifen in the adjuvant setting. Some observational studies have raised concerns that tamoxifen may be associated with an increased risk of Parkinson disease (PD). However, no studies have directly compared the risk of PD between AIs and tamoxifen in women diagnosed with breast cancer.

METHODS

Using the UK Clinical Practice Research Datalink, the authors assembled a cohort of women newly diagnosed with breast cancer and newly treated with either AIs or tamoxifen between January 1, 1995, and December 31, 2017. Patients were followed 1 year after treatment initiation (ie, a 1-year lag) until an incident diagnosis of PD or were censored at death from any cause, the date of transfer out of the practice, or the end of the study period (December 31, 2018). Cox proportional hazards models with inverse probability of treatment weights were used to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs) for PD comparing AIs with tamoxifen and accounting for more than 30 confounders.

RESULTS

In all, 30,140 women with nonmetastatic breast cancer were identified: 13,838 initiated AIs, and 16,302 initiated tamoxifen. Compared with tamoxifen, AIs were not associated with an increased risk of PD (HR, 0.94; 95% CI, 0.60-1.47). Consistent results were observed across all secondary and sensitivity analyses.

CONCLUSIONS

In this large observational study, the use of AIs, in comparison with tamoxifen, was not associated with an increased risk of PD in women diagnosed with nonmetastatic breast cancer in a real-world setting.

LAY SUMMARY

Previous studies have indicated that tamoxifen may increase the risk of Parkinson disease in the treatment of breast cancer. However, no studies have directly compared the risk of Parkinson disease between aromatase inhibitors and tamoxifen. This study included 30,140 women diagnosed with breast cancer and treated with aromatase inhibitors or tamoxifen. Overall, compared with tamoxifen, aromatase inhibitors were not associated with an increased risk of Parkinson disease in women diagnosed with breast cancer. This study provides an important addition to the comparative safety profile of aromatase inhibitors and tamoxifen in the treatment of breast cancer.

Restoration and targeting of aberrant neurotransmitters in Parkinson's disease therapeutics

Neurotransmitters are considered as a fundamental regulator in the process of neuronal growth, differentiation and survival. Parkinson's Disease (PD) occurs due to extensive damage of dopamine-producing neurons; this causes dopamine deficits in the midbrain, followed by the alternation of various other neurotransmitters (glutamate, GABA, serotonin, etc.). It has been observed that fluctuation of neurotransmission in the basal ganglia exhibits a great impact on the pathophysiology of PD. Dopamine replacement therapy, such as the use of L-DOPA, can increase the dopamine level, but it majorly ameliorates the motor symptoms and is also associated with long-term complications (for e.g., LID). While the non-dopaminergic system can efficiently target non-motor symptoms, for instance, the noradrenergic system regulates the synthesis of BDNF via the MAPK pathway, which is important in learning and memory. Herein, we briefly discuss the role of different neurotransmitters, implementation of neurotransmitter receptors in PD. We also illustrate the recent advances of neurotransmitter-based drugs, which are currently under in vivo and clinical studies. Reinstating normal neurotransmitter levels has been believed to be advantageous in the treatment of PD. Thus, there is an increasing demand for drugs that can specifically target the neurotransmission system and reinstate the normal levels of neurotransmitters, which might prevent or delay neurodegeneration in PD.

Trends in Prevalence Cases and Disability-Adjusted Life-Years of Parkinson's disease: Findings from the Global Burden of Disease Study 2019

BACKGROUND

Parkinson's disease is a common, age-related progressive neurodegenerative disorder with considerable socioeconomic burdens, although the studies in incremental burdens to the disease' rapid growth are incomplete and lag behind. We aim to assess global burdens of Parkinson's disease based on a public database online.

METHODS

Based on the Global Burden of Disease, Injuries, and Risk Factors Study, we screened a range of indicators including prevalence cases, disability-adjusted life-years (DALY), age-standardized prevalence rates (ASPR) and age-standardized DALY (ASDR). The Join point regression was used to assess the indicators, wherein the ASPR and the ASDR were referred to temporal trends for burdens of Parkinson's disease.

RESULTS

Prevalence cases of global Parkinson's disease were on the rise for 30 years, with an increase of 155.51% during 1990-2019. Temporal trend of ASDRs was on the rise during 1990-2002 but in decline during 2002-2019. The ASPRs had a turning point in 2017 and a decline during 2017-2019 (APC (annual percentage changes) =-0.51%, P > 0.05). China, India, the United States, Japan and Germany shared the five highest prevalence cases and DALYs in 2019. Socio-demographic Index (SDI) was in relation to a significantly positive ASPR (R=0.61, P < 0.001) but not a significantly negative ASDR (R=-0.044, P=0.53), respectively.

CONCLUSIONS

In this study, a range of indicators for global burdens of Parkinson's disease were on the rise during 1990-2019. Tremendous efforts should be in place to prevent Parkinson's disease, especially among the populations of males, with advanced ages, in East Asia, and in regions with high SDI.

Intake of Flavonoids and Flavonoid-Rich Foods and Mortality Risk Among Individuals With Parkinson Disease: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

Although flavonoids have the potential to exert neuroprotective benefits, evidence of their role in improving survival rates among individuals with Parkinson disease (PD) remains lacking. We aimed to prospectively study the association between prediagnosis and postdiagnosis flavonoid intakes and risk of mortality among individuals with PD identified from 2 large ongoing cohorts of US men and women.

METHODS

Included in the current analysis were 599 women from the Nurses' Health Study and 652 men from the Health Professionals Follow-Up Study who were newly diagnosed with PD during follow-up. Dietary intakes of total flavonoid and its subclasses, together with major flavonoid-rich foods (tea, apples, berries, orange and orange juice, and red wine), were repeatedly assessed with a validated food frequency questionnaire every 4 years. Mortality was ascertained via the National Death Index and state vital statistics records.

RESULTS

We documented 944 deaths during 32 to 34 years of follow-up. A higher total flavonoid intake before PD diagnosis was associated with a lower future risk for all-cause mortality in men (hazard ratio [HR] comparing 2 extreme quartiles 0.53, 95% confidence interval [CI] 0.39, 0.71; p for trend < 0.001) but not in women (HR 0.93, 95% CI 0.68, 1.28; p for trend = 0.69) after adjustment for age, smoking status, total energy intake, and other covariates. The pooled HR comparing the extreme quartiles was 0.70 (95% CI 0.40, 1.22; p for trend = 0.25) with significant heterogeneity (p = 0.01). For flavonoid subclasses, the highest quartile of anthocyanins, flavones, and flavan-3-ols intakes before diagnosis had a lower mortality risk compared to the lowest quartile (pooled HR 0.66, 0.78, and 0.69, respectively; p < 0.05 for all); for berries and red wine, participants consuming ≥3 servings per week had a lower risk (pooled HR 0.77, 95% CI 0.58, 1.02; and pooled HR 0.68, 95% CI 0.51, 0.91, respectively) compared to <1 serving per month. After PD diagnosis, greater consumptions of total flavonoid, subclasses including flavonols, anthocyanins, flavan-3-ols, and polymers, and berries and red wine were associated with lower mortality risk (p < 0.05 for all).

DISCUSSION

Among individuals with PD, higher consumption of flavonoids, especially anthocyanins and flavan-3-ols, and flavonoid-rich food such as berries and red wine was likely to be associated with a lower risk of mortality.

Hormones and Sex-Specific Medicine in Human Physiopathology

A prodigious increment of scientific evidence in both preclinical and clinical studies is narrowing a major gap in knowledge regarding sex-specific biological responses observed in numerous branches of clinical practices. Some paradigmatic examples include neurodegenerative and mental disorders, immune-related disorders such as pathogenic infections and autoimmune diseases, oncologic conditions, and cardiovascular morbidities. The male-to-female proportion in a population is expressed as sex ratio and varies eminently with respect to the pathophysiology, natural history, incidence, prevalence, and mortality rates. The factors that determine this scenario incorporate both sex-associated biological differences and gender-dependent sociocultural issues. A broad narrative review focused on the current knowledge about the role of hormone regulation in gender medicine and gender peculiarities across key clinical areas is provided. Sex differences in immune response, cardiovascular diseases, neurological disorders, cancer, and COVID-19 are some of the hints reported. Moreover, gender implications in occupational health and health policy are offered to support the need for more personalized clinical medicine and public health approaches to achieve an ameliorated quality of life of patients and better outcomes in population health.

Sex-based differences in histology, staging, and prognosis among 2983 gastric cancer surgery patients

BACKGROUND

Few studies have been conducted on sex differences in the incidence, pathophysiology, and prognosis of gastric cancer (GC).

AIM

To analyze the differences in GC characteristics according to sex in patients who underwent surgical treatment for GC.

METHODS

A total of 2983 patients diagnosed with gastric adenocarcinoma who received surgical treatment at the Seoul National University Bundang Hospital between 2003 and 2017 were included. Baseline clinicopathological characteristics, histologic type of GC, overall and GC-specific survival rates, and associated risk factors were analyzed.

RESULTS

Among the 2983 patients, 2005 (67.2%) and 978 (32.8%) were males and females, respectively. The average age of the female group (59.36 years) was significantly younger than that of the male group (61.66 years; P < 0.001). Cancer of the gastric body (P < 0.001) and diffuse-type histology (P < 0.001) were more common in females than in males. This trend was more prominent in females younger than 60 years of age, with a significantly higher proportion of diffuse-type cancer than in the male group. Regardless of sex, diffuse-type GC was more common in younger patients, and the proportion of intestinal-type GC increased with age. The overall survival rate was significantly higher in females (P < 0.001). However, this difference disappeared for GC-specific survival (P = 0.168), except for the poor GC-specific survival rate in advanced-stage cancer (stage III or above) in females (P = 0.045). The risk factors for GC-related mortality were older age, upper location of GC, and diffuse- or mixed-type histology. In terms of comorbidities, more males died from diseases other than GC, including other malignancies such as lung cancer, hepatocellular carcinoma, and pancreatic cancer, and respiratory diseases such as interstitial lung disease and chronic obstructive pulmonary disease, while there were relatively more cardiovascular or cerebrovascular deaths in females.

CONCLUSION

Sex-based differences in GC were observed in clinicopathological features, including age at diagnosis, tumor location, histologic type, survival rate, and comorbidities.

Parkinson's disease and cancer: a systematic review and meta-analysis on the influence of lifestyle habits, genetic variants, and gender

PURPOSE

The relationship between Parkinson's disease (PD) and cancer has been debated. Gender and genetic influences on cancer development in PD is unclear.

METHODS

Using QUOROM guidelines, we conducted a systematic review and meta-analysis on potential clinical and genetic factors influencing the PD and subsequent cancer relationship. English articles published in PubMed, Web of Science, and SCOPUS from 2010 to 30 August 2020 were considered for suitability.

RESULTS

Of 46 studies identified, fourteen satisfied the inclusion criteria and were further analysed. Unadjusted risk ratios (RR) and 95% confidence intervals were computed to determine the PD and cancer relationship. PD patients have decreased subsequent cancer risks (RR = 0.87, 95% CI = 0.81-0.93), reduced risks of colon, rectal, and colorectal cancer (RR = 0.77, 95% CI = 0.63-0.94), lung cancer (RR = 0.62, 95% CI = 0.48-0.80), and increased brain cancer (R = 1.48, 95% CI = 1.02-2.13) and melanoma risk (R = 1.76, 95% CI = 1.23-2.50). Compared to idiopathic PD, LRRK2-G2019S carriers had increased general cancer risks (RR = 1.26, 95% CI = 1.09-1.46), particularly brain (RR = 2.41, 95% CI = 1.06-5.50), breast (RR = 2.57, 95% CI = 1.19-5.58), colon (RR = 1.83, 95% CI = 1.13-2.99), and haematological cancers (RR = 2.05, 95% CI = 1.07-3.92). Female PD patients have decreased general cancer risks compared to male PD patients in this analysis (RR = 0.83, 95% CI = 0.69-0.98).

CONCLUSION

PD patients have reduced risks of colon, rectal, colorectal cancer and lung cancers and increased risks of brain cancer and melanoma. LRRK2-G2019S carriers have increased cancer risks, particularly brain, breast, colon and blood cancers. Female gender was associated with reduced risks. The role of ethnicity, comorbidities, and lifestyle habits on PD patients' subsequent cancer risk should be further investigated.

Gut dysbiosis and age-related neurological diseases in females

Historically, females have been underrepresented in biological research. With increased interest in the gut microbiome and the gut-brain axis, it is important for researchers to pursue studies that consider sex as a biological variable. The composition of the gut microbiome is influenced by environmental factors, disease, diet, and varies with age and by sex. Detrimental changes in the gut microbiome, referred to as dysbiosis, is believed to influence the development and progression of age-related neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and stroke. Many are investigating the changes in microbial populations in order or to better understand the role of the gut immunity and the microbiome in neurodegenerative diseases, many of which the exact etiology remains elusive, and no cures exist. Others are working to find diagnostic markers for earlier detection, or to therapeutically modulate microbial populations using probiotics. However, while all these diseases present in reproductively senescent females, most studies only use male animals for their experimental design. Reproductively senescent females have been shown to have differences in disease progression, inflammatory responses, and microbiota composition, therefore, for research to be translational to affected populations it is necessary for appropriate models to be used. This review discusses factors that influence the gut microbiome and the gut brain axis in females, and highlights studies that have investigated the role of dysbiosis in age-related neurodegenerative disorders that have included females in their study design.

Bone Quality in Patients with Parkinson's Disease Determined by Quantitative Ultrasound (QUS) of the Calcaneus: Influence of Sex Differences

(1) Background: Parkinson’s disease (PD) is a relatively common neurodegenerative disease in elderly individuals, with a high risk of falls. There is abundant literature on the relationship between PD and osteoporosis. The aim of this study is to describe the bone quality of a population with PD by calcaneal ultrasound and to compare it with a healthy control, assessing the influence of possible sex differences. (2) Methods: 21 patients diagnosed with PD were recruited. The control group was composed of 30 healthy individuals with similar sociodemographic characteristics. The bone quality of all participants was assessed using calcaneal quantitative ultrasound (QUS). The parameters recorded were broadband ultrasound attenuation (BUA, in decibels per megahertz), imaging speed of sound (SOS, in meters per second), stiffness index (SI) and T-score of each participant. Bone mineral density (BMD) was estimated using the equation BMD = 0.002592 × (BUA + SOS) − 3.687 (g/cm2). (3) Results: significant differences were observed between the healthy control and the PD group: the T-score was lower in the PD group (p < 0.05) and SOS was higher in Parkinson’s disease patients (p < 0.05), while 28.6% of the PD patients were osteoporotic with T-score values lower than −1.5 compared to 16.7% of osteoporotic individuals in the control group (p < 0.01). Regarding the sex, there were significant differences (p < 0.05) between the females of the PD group vs. control group, showing a significant difference in the SI (71.4 ± 14.7 vs. 87.8 ± 12), T-score (−2.19 ± 1.1 vs. −0.15 ± 0.8), BUA (104.5 ± 13 vs. 116 ± 10.6) and BMD (0.49 ± 0.09 vs. 0.60 ± 0.08), with no difference in the comparison between the male groups; and the comparison between both sexes in T-score only showed significant differences for the PD group (p < 0.05), with worse bone quality in women. (4) Conclusions: this study shows poorer bone quality in female patients with PD, who have a higher percentage of osteoporosis than healthy patients. The QUS technique of the calcaneus seems adequate for these determinations in patients with Parkinson’s disease.

Steroid Sulfation in Neurodegenerative Diseases

Steroid sulfation and desulfation participates in the regulation of steroid bioactivity, metabolism and transport. The authors focused on sulfation and desulfation balance in three neurodegenerative diseases: Alzheimer´s disease (AD), Parkinson´s disease (PD), and multiple sclerosis (MS). Circulating steroid conjugates dominate their unconjugated counterparts, but unconjugated steroids outweigh their conjugated counterparts in the brain. Apart from the neurosteroid synthesis in the central nervous system (CNS), most brain steroids cross the blood-brain barrier (BBB) from the periphery and then may be further metabolized. Therefore, steroid levels in the periphery partly reflect the situation in the brain. The CNS steroids subsequently influence the neuronal excitability and have neuroprotective, neuroexcitatory, antidepressant and memory enhancing effects. They also exert anti-inflammatory and immunoprotective actions. Like the unconjugated steroids, the sulfated ones modulate various ligand-gated ion channels. Conjugation by sulfotransferases increases steroid water solubility and facilitates steroid transport. Steroid sulfates, having greater half-lives than their unconjugated counterparts, also serve as a steroid stock pool. Sulfotransferases are ubiquitous enzymes providing massive steroid sulfation in adrenal zona reticularis and zona fasciculata.. Steroid sulfatase hydrolyzing the steroid conjugates is exceedingly expressed in placenta but is ubiquitous in low amounts including brain capillaries of BBB which can rapidly hydrolyze the steroid sulfates coming across the BBB from the periphery. Lower dehydroepiandrosterone sulfate (DHEAS) plasma levels and reduced sulfotransferase activity are considered as risk factors in AD patients. The shifted balance towards unconjugated steroids can participate in the pathophysiology of PD and anti-inflammatory effects of DHEAS may counteract the MS.

Contribution of Autophagy-Lysosomal Pathway in the Exosomal Secretion of Alpha-Synuclein and Its Impact in the Progression of Parkinson’s Disease

Parkinson’s disease (PD) is caused by the degeneration of dopaminergic neurons due to an accumulation of intraneuronal abnormal alpha-synuclein (α-syn) protein aggregates. It has been reported that the levels of exosomal α-syn of neuronal origin in plasma correlate significantly with motor dysfunction, highlighting the exosomes containing α-syn as a potential biomarker of PD. In addition, it has been found that the selective autophagy-lysosomal pathway (ALP) contributes to the secretion of misfolded proteins involved in neurodegenerative diseases. In this review, we describe the evidence that supports the relationship between the ALP and α-syn exosomal secretion on the PD progression and its implications in the diagnosis and progression of this pathology.

Neuromelanin-MRI to Quantify and Track Nigral Depigmentation in Parkinson's Disease: A Multicenter Longitudinal Study Using Template-Based Standardized Analysis

Background

Clinical diagnosis and monitoring of Parkinson's disease (PD) remain challenging because of the lack of an established biomarker. Neuromelanin‐magnetic resonance imaging (NM‐MRI) is an emerging biomarker of nigral depigmentation indexing the loss of melanized neurons but has unknown prospective diagnostic and tracking performance in multicenter settings.

Objectives

The aim was to investigate the diagnostic accuracy of NM‐MRI in early PD in a multiprotocol setting and to determine and compare serial NM‐MRI changes in PD and controls.

Methods

In this longitudinal case–control 3 T MRI study, 148 patients and 97 controls were included from six UK clinical centers, of whom 140 underwent a second scan after 1.5 to 3 years. An automated template‐based analysis was applied for subregional substantia nigra NM‐MRI contrast and volume assessment. A point estimate of the period of prediagnostic depigmentation was computed.

Results

All NM metrics performed well to discriminate patients from controls, with receiver operating characteristic showing 85% accuracy for ventral NM contrast and 83% for volume. Generalizability using a priori volume cutoff was good (79% accuracy). Serial MRI demonstrated accelerated NM loss in patients compared to controls. Ventral NM contrast loss was point estimated to start 5 to 6 years before clinical diagnosis. Ventral nigral depigmentation was greater in the most affected side, more severe cases, and nigral NM volume change correlated with change in motor severity.

Conclusions

We demonstrate that NM‐MRI provides clinically useful diagnostic information in early PD across protocols, platforms, and sites. It provides methods and estimated depigmentation rates that highlight the potential to detect preclinical PD and track progression for biomarker‐enabled clinical trials. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Metabolite and lipoprotein profiles reveal sex-related oxidative stress imbalance in de novo drug-naive Parkinson's disease patients

Parkinson’s disease (PD) is the neurological disorder showing the greatest rise in prevalence from 1990 to 2016. Despite clinical definition criteria and a tremendous effort to develop objective biomarkers, precise diagnosis of PD is still unavailable at early stage. In recent years, an increasing number of studies have used omic methods to unveil the molecular basis of PD, providing a detailed characterization of potentially pathological alterations in various biological specimens. Metabolomics could provide useful insights to deepen our knowledge of PD aetiopathogenesis, to identify signatures that distinguish groups of patients and uncover responsive biomarkers of PD that may be significant in early detection and in tracking the disease progression and drug treatment efficacy. The present work is the first large metabolomic study based on nuclear magnetic resonance (NMR) with an independent validation cohort aiming at the serum characterization of de novo drug-naive PD patients. Here, NMR is applied to sera from large training and independent validation cohorts of German subjects. Multivariate and univariate approaches are used to infer metabolic differences that characterize the metabolite and the lipoprotein profiles of newly diagnosed de novo drug-naive PD patients also in relation to the biological sex of the subjects in the study, evidencing a more pronounced fingerprint of the pathology in male patients. The presence of a validation cohort allowed us to confirm altered levels of acetone and cholesterol in male PD patients. By comparing the metabolites and lipoproteins levels among de novo drug-naive PD patients, age- and sex-matched healthy controls, and a group of advanced PD patients, we detected several descriptors of stronger oxidative stress.

Circular RNA as a Potential Biomarker for Forensic Age Prediction

In forensic science, accurate estimation of the age of a victim or suspect can facilitate the investigators to narrow a search and aid in solving a crime. Aging is a complex process associated with various molecular regulations on DNA or RNA levels. Recent studies have shown that circular RNAs (circRNAs) upregulate globally during aging in multiple organisms such as mice and C.elegans because of their ability to resist degradation by exoribonucleases. In the current study, we attempted to investigate circRNAs’ potential capability of age prediction. Here, we identified more than 40,000 circRNAs in the blood of thirteen Chinese unrelated healthy individuals with ages of 20–62 years according to their circRNA-seq profiles. Three methods were applied to select age-related circRNA candidates including the false discovery rate, lasso regression, and support vector machine. The analysis uncovered a strong bias for circRNA upregulation during aging in human blood. A total of 28 circRNAs were chosen for further validation in 30 healthy unrelated subjects by RT-qPCR, and finally, 5 age-related circRNAs were chosen for final age prediction models using 100 samples of 19–73 years old. Several different algorithms including multivariate linear regression (MLR), regression tree, bagging regression, random forest regression (RFR), and support vector regression (SVR) were compared based on root mean square error (RMSE) and mean average error (MAE) values. Among five modeling methods, regression tree and RFR performed better than the others with MAE values of 8.767 years (S.rho = 0.6983) and 9.126 years (S.rho = 0.660), respectively. Sex effect analysis showed age prediction models significantly yielded smaller prediction MAE values for males than females (MAE = 6.133 years for males, while 10.923 years for females in the regression tree model). In the current study, we first used circRNAs as additional novel age-related biomarkers for developing forensic age estimation models. We propose that the use of circRNAs to obtain additional clues for forensic investigations and serve as aging indicators for age prediction would become a promising field of interest.

Disease-Modifying Antirheumatic Drugs and Risk of Parkinson Disease: Nested Case-Control Study of People With Rheumatoid Arthritis

BACKGROUND

Epidemiological studies have suggested a link between rheumatoid arthritis and Parkinson's disease (PD). Disease-modifying anti-rheumatic drugs (DMARDs) might explain this association.

OBJECTIVE

To evaluate the association between DMARDs and risk of PD in persons with rheumatoid arthritis.

METHODS

Nested nationwide case-control study was conducted within the Finnish Parkinson's disease (FINPARK) cohort that includes 22,189 Finnish persons with clinically verified PD diagnosed in 1996-2015. The cases had recorded diagnosis of PD in the Special Reimbursement Register and had no exclusion diagnoses whose symptoms may be confused with PD within two years of PD diagnosis. This study included cases with PD diagnosed during 1999-2015 and rheumatoid arthritis diagnosed >3 years before PD. Rheumatoid arthritis was identified using Finnish Care Register for Health Care and Special Reimbursement Register. Cases were matched with up to seven control persons by age, sex, duration of rheumatoid arthritis and region. DMARDs were categorised into five classes and data on purchased prescriptions was identified from the Prescription Register since 1995. Associations were studied with conditional logistic regression adjusted for confounders.

RESULTS

Altogether 315 cases with PD and 1,571 matched controls were included. Majority (> 60%) were women and median duration of rheumatoid arthritis on matching date was 11.6 years for controls and 12.6 years for cases. Use of DMARDs was not associated with risk of PD with three-year lag period applied between exposure and outcome, except chloroquine/hydroxychloroquine which associated with decreased risk (adjusted odds ratio 0.74; 95% confidence interval 0.56-0.97). Other DMARDs, including sulfasalazine, methotrexate, gold preparations and immunosuppressants, were not associated with PD.

DISCUSSION

Our results suggest that the lower risk of PD in people with rheumatoid arthritis is not explained by DMARD use as these drugs in general did not modify the risk of PD among persons with rheumatoid arthritis. Association between chloroquine/hydroxychloroquine and lower risk of PD as well as the possible underlying mechanisms should be further investigated.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in individuals with rheumatoid arthritis using DMARDs, only chloroquine/hydroxychloroquine was associated with a potentially decreased risk of developing PD (adjusted OR 0.74, 95% CI 0.56-0.97).

Gender differences in motor and non-motor symptoms in early Parkinson disease

Gender differences in motor and non-motor symptoms in Parkinson disease (PD) are still controversial. This study aimed to investigate gender differences in clinical characteristics in patients with early PD.This study included 415 PD patients (201 men and 214 women) with modified Hoehn-Yahr stage 1 to 3 and a disease duration of ≤5 years. Demographic information was obtained by interviews, and motor and non-motor PD symptoms were evaluated with appropriate scales.Women with PD had a shorter duration of formal education than men with PD. No significant differences were found in other demographic variables. Women with PD had significantly lower scores in Unified Parkinson Disease Rating Scale part III and postural tremor compared to men with PD, which was significant after controlling for formal education. No significant gender-related differences were found in scores related to other motor symptoms. Concerning non-motor symptoms, men with PD had higher scores of sexual function on the Non-Motor Symptoms Scale, which means sexual dysfunction was more severe or occurred more frequently in men with PD. Women with PD had significantly higher scores of sleep disturbance in the Pittsburgh Sleep Quality Index, which was not significant after adjustment for multiple comparison.The present study suggests that women with PD had milder motor symptoms compared to men with PD, and gender differences in sexual function can be observed as non-motor symptoms.

Desferrioxamine Ameliorates Lipopolysaccharide-Induced Lipocalin-2 Upregulation via Autophagy Activation in Primary Astrocytes

Lipocalin-2 (LCN2) is an important regulator of both neuroinflammation and iron homeostasis. Upregulated LCN2 was observed in reactive astrocytes in the Parkinson's disease (PD) models. In the present study, we reported iron chelator deferoxamine (DFO) abolished lipopolysaccharide (LPS)-induced LCN2 upregulation in primary astrocytes, although iron overload had no effects. The suppressive effects of DFO were consistent with autophagy inducer rapamycin or carfilzomib, blocked by autophagy inhibitor 3-methyladenine rather than chloroquine or bafilomycin A1, meanwhile, while were not dependent on proteasome system and NF-κB pathway. DFO was not able to ameliorate LCN2 upregulation in α-synuclein-treated astrocytes, because DFO failed to induce autophagy in these cells. We further demonstrated that DFO could not enhance autophagy lysosomal degradation, however promoted secretory autophagy in primary astrocytes with LPS insults. These data suggest that DFO could serve as an autophagy activator, capable of ameliorating the upregulation of LCN2 in astrocytes by acting on the formation of autophagosomes and secretory autophagy. This provides better understandings of DFO-mediated neuroprotection against neuroinflammation and provides new insights that autophagy activation could be beneficial approaches in PD.

Thalamic white matter macrostructure and subnuclei volumes in Parkinson's disease depression

Depression is a common non-motor feature of Parkinson's disease (PD) which confers significant morbidity and is challenging to treat. The thalamus is a key component in the basal ganglia-thalamocortical network critical to the pathogenesis of PD and depression but the precise thalamic subnuclei involved in PD depression have not been identified. We performed structural and diffusion-weighted imaging (DWI) on 76 participants with PD to evaluate the relationship between PD depression and grey and white matter thalamic subnuclear changes. We used a thalamic segmentation method to divide the thalamus into its 50 constituent subnuclei (25 each hemisphere). Fixel-based analysis was used to calculate mean fibre cross-section (FC) for white matter tracts connected to each subnucleus. We assessed volume and FC at baseline and 14-20 months follow-up. A generalised linear mixed model was used to evaluate the relationship between depression, subnuclei volume and mean FC for each thalamic subnucleus. We found that depression scores in PD were associated with lower right pulvinar anterior (PuA) subnucleus volume. Antidepressant use was associated with higher right PuA volume suggesting a possible protective effect of treatment. After follow-up, depression scores were associated with reduced white matter tract macrostructure across almost all tracts connected to thalamic subnuclei. In conclusion, our work implicates the right PuA as a relevant neural structure in PD depression and future work should evaluate its potential as a therapeutic target for PD depression.

Identification of an early-stage Parkinson's disease neuromarker using event-related potentials, brain network analytics and machine-learning

OBJECTIVE

The purpose of this study is to explore the possibility of developing a biomarker that can discriminate early-stage Parkinson's disease from healthy brain function using electroencephalography (EEG) event-related potentials (ERPs) in combination with Brain Network Analytics (BNA) technology and machine learning (ML) algorithms.

BACKGROUND

Currently, diagnosis of PD depends mainly on motor signs and symptoms. However, there is need for biomarkers that detect PD at an earlier stage to allow intervention and monitoring of potential disease-modifying therapies. Cognitive impairment may appear before motor symptoms, and it tends to worsen with disease progression. While ERPs obtained during cognitive tasks performance represent processing stages of cognitive brain functions, they have not yet been established as sensitive or specific markers for early-stage PD.

METHODS

Nineteen PD patients (disease duration of ≤2 years) and 30 healthy controls (HC) underwent EEG recording while performing visual Go/No-Go and auditory Oddball cognitive tasks. ERPs were analyzed by the BNA technology, and a ML algorithm identified a combination of features that distinguish early PD from HC. We used a logistic regression classifier with a 10-fold cross-validation.

RESULTS

The ML algorithm identified a neuromarker comprising 15 BNA features that discriminated early PD patients from HC. The area-under-the-curve of the receiver-operating characteristic curve was 0.79. Sensitivity and specificity were 0.74 and 0.73, respectively. The five most important features could be classified into three cognitive functions: early sensory processing (P50 amplitude, N100 latency), filtering of information (P200 amplitude and topographic similarity), and response-locked activity (P-200 topographic similarity preceding the motor response in the visual Go/No-Go task).

CONCLUSIONS

This pilot study found that BNA can identify patients with early PD using an advanced analysis of ERPs. These results need to be validated in a larger PD patient sample and assessed for people with premotor phase of PD.

Sex Differences in Brain and Cognition in de novo Parkinson's Disease

Background and Objective: Brain atrophy and cognitive impairment in neurodegenerative diseases are influenced by sex. We aimed to investigate sex differences in brain atrophy and cognition in de novo Parkinson's disease (PD) patients. Methods: Clinical, neuropsychological and T1-weighted MRI data from 205 PD patients (127 males: 78 females) and 69 healthy controls (40 males: 29 females) were obtained from the PPMI dataset. Results: PD males had a greater motor and rapid eye movement sleep behavior disorder symptomatology than PD females. They also showed cortical thinning in postcentral and precentral regions, greater global cortical and subcortical atrophy and smaller volumes in thalamus, caudate, putamen, pallidum, hippocampus, and brainstem, compared with PD females. Healthy controls only showed reduced hippocampal volume in males compared to females. PD males performed worse than PD females in global cognition, immediate verbal recall, and mental processing speed. In both groups males performed worse than females in semantic verbal fluency and delayed verbal recall; as well as females performed worse than males in visuospatial function. Conclusions: Sex effect in brain and cognition is already evident in de novo PD not explained by age per se, being a relevant factor to consider in clinical and translational research in PD.

Longitudinal Change and Progression Indicators Using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale in Two Independent Cohorts with Early Parkinson's Disease

BACKGROUND

The MDS-Unified Parkinson's disease (PD) Rating Scale (MDS-UPDRS) is the most used scale in clinical trials. Little is known about the predictive potential of its single items.

OBJECTIVE

To systematically dissect MDS-UPDRS to predict PD progression.

METHODS

574 de novo PD patients and 305 healthy controls were investigated at baseline (BL) in the single-center DeNoPa (6-year follow-up) and multi-center PPMI (8-year follow-up) cohorts. We calculated cumulative link mixed models of single MDS-UPDRS items for odds ratios (OR) for class change within the scale. Models were adjusted for age, sex, time, and levodopa equivalent daily dose. Annual change and progression of the square roots of the MDS-UDPRS subscores and Total Score were estimated by linear mixed modeling.

RESULTS

Baseline demographics revealed more common tremor dominant subtype in DeNoPa and postural instability and gait disorders-subtype and multiethnicity in PPMI. Subscore progression estimates were higher in PPMI but showed similar slopes and progression in both cohorts. Increased ORs for faster progression were found from BL subscores I and II (activities of daily living; ADL) most marked for subscore III (rigidity of neck/lower extremities, agility of the legs, gait, hands, and global spontaneity of movements). Tremor items showed low ORs/negative values.

CONCLUSION

Higher scores at baseline for ADL, freezing, and rigidity were predictors of faster deterioration in both cohorts. Precision and predictability of the MDS-UPDRS were higher in the single-center setting, indicating the need for rigorous training and/or video documentation to improve its use in multi-center cohorts, for example, clinical trials.

Water Extract of Rhizoma Drynaria Selectively Exerts Estrogenic Activities in Ovariectomized Rats and Estrogen Receptor-Positive Cells

Our previous study demonstrated that the bone protective actions of herbal medicine Rhizoma Drynariae (Gusuibu, RD) were mainly mediated by flavonoid phytoestrogens via estrogen receptors, raising concerns about the safety of using RD as it may induce estrogen-like risk-benefit profile and interact with other ER ligands, such as selective estrogen receptor modulators (SERMs), when coadministered. The present study evaluated the estrogenic activities of RD and its potential interaction with tamoxifen, a SERM, in estrogen-sensitive tissues by using mature ovariectomized (OVX) rats and ER-positive cells. Similar to but weaker than tamoxifen, RD at its clinical dose dramatically ameliorated OVX-induced changes in bone and dopamine metabolism-related markers in OVX rats. However, tamoxifen, but not RD, induced uterotrophic effects. No significant alteration in mammary gland was observed in OVX rats treated with RD, which was different from the inhibitory actions of tamoxifen. The two-way ANOVA results indicated the interactions between RD and tamoxifen in the bone, brain, and uterus of OVX rats while RD did not alter their responses to tamoxifen. Our results demonstrate that RD selectively exerts estrogenic actions in a different manner from tamoxifen. Moreover, RD interacts with tamoxifen without altering its effects in OVX rats.

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

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

Efficacy of Safinamide and Gender Differences During Routine Clinical Practice

Background: There is increasing evidence of gender differences in the epidemiology and clinical manifestation of both motor and non-motor symptoms of Parkinson's disease (PD). Nevertheless, few data are available on gender differences in the response to antiparkinsonian drugs. Safinamide is a multimodal drug with positive effects on motor and non-motor fluctuations that might improve patients' care and quality of life. Objective: To analyze gender differences on clinical effects of safinamide in PD patients treated in real-life conditions during the SYNAPSES trial. Methods: SYNAPSES was a multinational, multicenter, observational study. At baseline, patients with PD diagnosis received safinamide as an add-on to levodopa and were followed up for 12 months, with visits performed every 4 months. A new statistical analysis was performed to describe the efficacy of safinamide in men and women on motor complications, motor symptoms, and adverse events. Results: Six hundred and sixteen (38%) out of 1,610 patients enrolled in the SYNAPSES study were women and 994 (62%) men. Safinamide improved motor symptoms and motor complications (fluctuations and dyskinesia) in both genders, with a good safety profile and without requiring any change in the concomitant dopaminergic therapy. Clinically significant improvements, according to the criteria developed by Shulman et al., were seen in 46% of male and female patients for the UPDRS motor score and 43.5% of men vs. 39.1% of women for the UPDRS total score. Conclusions: Safinamide was effective in improving motor fluctuations and dyskinesia and proved to be safe in both male and female patients with PD. Further prospective studies, specifically addressing potential gender differences in response to PD therapies, are needed to develop tailored management strategies.

Sex is a defining feature of neuroimaging phenotypes in major brain disorders

Sex is a biological variable that contributes to individual variability in brain structure and behavior. Neuroimaging studies of population-based samples have identified normative differences in brain structure between males and females, many of which are exacerbated in psychiatric and neurological conditions. Still, sex differences in MRI outcomes are understudied, particularly in clinical samples with known sex differences in disease risk, prevalence, and expression of clinical symptoms. Here we review the existing literature on sex differences in adult brain structure in normative samples and in 14 distinct psychiatric and neurological disorders. We discuss commonalities and sources of variance in study designs, analysis procedures, disease subtype effects, and the impact of these factors on MRI interpretation. Lastly, we identify key problems in the neuroimaging literature on sex differences and offer potential recommendations to address current barriers and optimize rigor and reproducibility. In particular, we emphasize the importance of large-scale neuroimaging initiatives such as the Enhancing NeuroImaging Genetics through Meta-Analyses consortium, the UK Biobank, Human Connectome Project, and others to provide unprecedented power to evaluate sex-specific phenotypes in major brain diseases.

Identification of Novel Biomarkers in Platelets for Diagnosing Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disease affecting the elderly, but there is no blood test for PD diagnosis in the clinic currently. This study aimed to explore promising biomarkers in platelets (PLTs) for PD diagnosis.

METHODS

PLTs were isolated from whole blood samples of PD patients and healthy controls (HCs), and RNA was extracted for sequencing. RNA-seq was performed on the Illumina HiSeq platform.

RESULTS

A total of 2,221 genes with differential transcript levels (GDTLs) were identified between PD patients and HCs, 1,041 of which are upregulated genes and 1,180 of which are downregulated genes. WASH5P was the most upregulated gene and AC114491.1 was the most downregulated gene. Among the top 12 most relevant genes, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), eukaryotic elongation factor 1A (EEF1A1), and cathepsin S (CTSS) were reported to be associated with PD. Furthermore, gene ontology analysis showed that the most significant term in biological processes was neutrophil degranulation; the most enriched term in cellular components was cytoplasmic vesicle lumen; and tumor necrosis factor receptor superfamily binding was the most significant term in molecular functions. In the Kyoto Encyclopedia of Genes and Genomes enrichment analysis, inflammation-related pathway accounts for the majority.

CONCLUSION

Our findings demonstrated WASH5P, MALAT1, EEF1A1, and CTSS may be promising biomarkers in PD, which may contribute to improving the effectiveness and accuracy of diagnosis for PD in the future.

Prevalence of Parkinson's disease in China: a multicenter population-based survey

OBJECTIVE

Few data are available on the current prevalence of Parkinson's disease in China. The aim of this study was to determine the prevalence of Parkinson's disease in Chinese individuals aged 65 years and older and to analyze associated risk factors.

METHODS

We performed a population-based cross-sectional survey with a multistage cluster sampling design. Residents aged 65 and over were drawn from 11 urban districts and 10 rural counties across China. Data were entered into spreadsheets, and imported and analyzed using Statistical Package SPSS 24.

RESULTS

We identified 151 patients with Parkinson's disease among 8124 residents aged 65 and over, including 75 men (49.67%) and 76 women (50.33%). The overall prevalence of PD in the study population was 1.86% (95% confidence interval [CI]: 1.6%-2.2%), and the standardized prevalence of PD was 1.60%. The crude prevalence in men (2.12%) was higher than in women (1.66%), and standardized prevalence in urban areas (1.98%) was higher than in rural areas (1.48%). Logistic regression analysis showed that independent risk factors for PD were older age, heavy metal or pesticide exposure (odds ratio [OR]=3.83; 95% CI: 2.021-7.256), urban residence (OR=1.307; 95% CI: 1.041-1.642), rapid eye movement sleep behavior disorder (OR=1.450; 95% CI: 1.021-2.059), and heart disease (OR=2.431; 95% CI: 1.481-4.990). Conclusion：The prevalence of Parkinson's disease in individuals aged 65 and older in China has not increased significantly in recent years. The prevalence of Parkinson's disease is higher in men than in women and higher in urban areas than in rural areas.

Sex-Related Longitudinal Change of Motor, Non-Motor, and Biological Features in Early Parkinson's Disease

Background:

Investigation of sex-related motor and non-motor differences and biological markers in Parkinson’s disease (PD) may improve precision medicine approach.

Objective:

To examine sex-related longitudinal changes in motor and non-motor features and biologic biomarkers in early PD.

Methods:

We compared 5-year longitudinal changes in de novo, untreated PD men and women (at baseline N = 423; 65.5%male) of the Parkinson’s Progression Markers Initiative (PPMI), assessing motor and non-motor manifestations of disease; and biologic measures in cerebrospinal fluid (CSF) and dopamine transporter deficit on DaTscan^TM uptake.

Results:

Men experienced greater longitudinal decline in self-reported motor (p < 0.001) and non-motor (p = 0.009) aspects of experiences of daily living, such that men had a yearly increase in MDS-UPDRS part II by a multiplicative factor of 1.27 compared to women at 0.7, while men had a yearly increase in MDS-UPDRS part I by a multiplicative factor of 0.98, compared to women at 0.67. Compared to women, men had more longitudinal progression in clinician-assessed motor features in the ON medication state (p = 0.010) and required higher dopaminergic medication dosages over time (p = 0.014). Time to reach specific disease milestones and longitudinal changes in CSF biomarkers and DaTscan^TM uptake were not different by sex.

Conclusion:

Men showed higher self-assessed motor and non-motor burden of disease, with possible contributions from suboptimal dopaminergic therapeutic response in men. However, motor features of disease evaluated with clinician-based scales in the OFF medication state, as well as biological biomarkers do not show specific sex-related progression patterns.

Neurodegenerative Disease: Roles for Sex, Hormones, and Oxidative Stress

Neurodegenerative diseases cause severe impairments in cognitive and motor function. With an increasing aging population and the onset of these diseases between 50 and 70 years, the consequences are bound to be devastating. While age and longevity are the main risk factors for neurodegenerative diseases, sex is also an important risk factor. The characteristic of sex is multifaceted, encompassing sex chromosome complement, sex hormones (estrogens and androgens), and sex hormone receptors. Sex hormone receptors can induce various signaling cascades, ranging from genomic transcription to intracellular signaling pathways that are dependent on the health of the cell. Oxidative stress, associated with aging, can impact the health of the cell. Sex hormones can be neuroprotective under low oxidative stress conditions but not in high oxidative stress conditions. An understudied sex hormone receptor that can induce activation of oxidative stress signaling is the membrane androgen receptor (mAR). mAR can mediate nicotinamide adenine dinucleotide-phosphate (NADPH) oxidase (NOX)-generated oxidative stress that is associated with several neurodegenerative diseases, such as Alzheimer disease. Further complicating this is that aging can alter sex hormone signaling. Prior to menopause, women experience more estrogens than androgens. During menopause, this sex hormone profile switches in women due to the dramatic ovarian loss of 17β-estradiol with maintained ovarian androgen (testosterone, androstenedione) production. Indeed, aging men have higher estrogens than aging women due to aromatization of androgens to estrogens. Therefore, higher activation of mAR-NOX signaling could occur in menopausal women compared with aged men, mediating the observed sex differences. Understanding of these signaling cascades could provide therapeutic targets for neurodegenerative diseases.

Astrocyte dysfunction in Parkinson's disease: from the perspectives of transmitted α-synuclein and genetic modulation

Parkinson's disease (PD) is a common neurodegenerative disorder that primarily affects the elderly. While the etiology of PD is likely multifactorial with the involvement of genetic, environmental, aging and other factors, α-synuclein (α-syn) pathology is a pivotal mechanism underlying the development of PD. In recent years, astrocytes have attracted considerable attention in the field. Although astrocytes perform a variety of physiological functions in the brain, they are pivotal mediators of α-syn toxicity since they internalize α-syn released from damaged neurons, and this triggers an inflammatory response, protein degradation dysfunction, mitochondrial dysfunction and endoplasmic reticulum stress. Astrocytes are indispensable coordinators in the background of several genetic mutations, including PARK7, GBA1, LRRK2, ATP13A2, PINK1, PRKN and PLA2G6. As the most abundant glial cells in the brain, functional astrocytes can be replenished and even converted to functional neurons. In this review, we discuss astrocyte dysfunction in PD with an emphasis on α-syn toxicity and genetic modulation and conclude that astrocyte replenishment is a valuable therapeutic approach in PD.

Associations of sleep disorders with cerebrospinal fluid α-synuclein in prodromal and early Parkinson's disease

OBJECTIVES

Our aim is to investigate the associations of sleep disorders with cerebrospinal fluid (CSF) α-synuclein (α-syn) in healthy controls (HCs), and patients with prodromal and early Parkinson's disease (PD).

METHODS

We included a total of 575 individuals, consisting of 360 PD individuals, 46 prodromal PD individuals, and 169 HCs. Multiple linear regression models and linear mixed-effects models were used to investigate the associations of sleep disorders with baseline and longitudinal CSF α-syn. Associations between the change rates of sleep disorders and CSF α-syn were further investigated via multiple linear regression models.

RESULTS

In PD, probable Rapid-eye-movement sleep Behavior Disorder (pRBD) (β = - 0.1199; P = 0.0444) and RBD sub-items, such as aggressive dreams (β = - 0.1652; P = 0.0072) and hurting bed partner (β = - 0.2468; P = 0.0010), contributed to lower CSF α-syn. The association between aggressive dreams and lower CSF α-syn further survived Bonferroni correction (P < 0.0036). In prodromal PD, dream-enacting (a specific RBD behavior) was significantly associated with decreased CSF α-syn during the follow-up (β = - 0.0124; P = 0.0237). HCs with daytime sleepiness when inactive-sitting in public places (β = - 0.0033; P = 0.0135) showed decreased CSF α-syn. Furthermore, increased possibilities of daytime sleepiness when sitting and reading contributed to a greater decrease of CSF α-syn in HCs (β = - 196.8779; P = 0.0433).

CONCLUSIONS

Sleep disorders were associated with decreased CSF α-syn. Sleep management may be important for disease monitoring and preventing the progression of α-syn pathology.

Heat Shock Protein 70 as a Sex-Skewed Regulator of α-Synucleinopathy

The role of molecular chaperones, such as heat shock protein 70 (Hsp70), is not typically studied as a function of biological sex, but by addressing this gap we might improve our understanding of proteinopathic disorders that predominate in one sex. Therefore, we exposed male or female primary hippocampal cultures to preformed α-synuclein fibrils in a model of early-stage Lewy pathology. We first discovered that two mechanistically distinct inhibitors of Hsp70 function increased phospho-α-synuclein+ inclusions more robustly in male-derived neurons. Because Hsp70 is released into extracellular compartments and may restrict cell-to-cell transmission/amplification of α-synucleinopathy, we then tested the effects of low-endotoxin, exogenous Hsp70 (eHsp70) in primary hippocampal cultures. eHsp70 was taken up by and reduced α-synuclein+ inclusions in cells of both sexes, but pharmacological suppression of Hsp70 function attenuated the inhibitory effect of eHsp70 on perinuclear inclusions only in male neurons. In 20-month-old male mice infused with α-synuclein fibrils in the olfactory bulb, daily intranasal eHsp70 delivery also reduced inclusion numbers and the time to locate buried food. eHsp70 penetrated the limbic system and spinal cord of male mice within 3 h but was cleared within 72 h. Unexpectedly, no evidence of eHsp70 uptake from nose into brain was observed in females. A trend towards higher expression of inducible Hsp70-but not constitutive Hsp70 or Hsp40-was observed in amygdala tissues from male subjects with Lewy body disorders compared to unaffected male controls, supporting the importance of this chaperone in human disease. Women expressed higher amygdalar Hsp70 levels compared to men, regardless of disease status. Together, these data provide a new link between biological sex and a key chaperone that orchestrates proteostasis.

Dopamine Modulates Drosophila Gut Physiology, Providing New Insights for Future Gastrointestinal Pharmacotherapy

Dopamine has a variety of physiological roles in the gastrointestinal tract (GI) through binding to Drosophila dopamine D1-like receptors (DARs) and/or adrenergic receptors and has been confirmed as one of the enteric neurotransmitters. To gain new insights into what could be a potential future promise for GI pharmacology, we used Drosophila as a model organism to investigate the effects of dopamine on intestinal physiology and gut motility. GAL4/UAS system was utilized to knock down specific dopamine receptors using specialized GAL4 driver lines targeting neurons or enterocytes cells to identify which dopamine receptor controls stomach contractions. DARs (Dop1R1 and Dop1R2) were shown by immunohistochemistry to be strongly expressed in all smooth muscles in both larval and adult flies, which could explain the inhibitory effect of dopamine on GI motility. Adult males' gut peristalsis was significantly inhibited by knocking down dopamine receptors Dop1R1, Dop1R2, and Dop2R, but female flies' gut peristalsis was significantly repressed by knocking down only Dop1R1 and Dop1R2. Our findings also showed that dopamine drives PLC-β translocation from the cytoplasm to the plasma membrane in enterocytes for the first time. Overall, these data revealed the role of dopamine in modulating Drosophila gut physiology, offering us new insights for the future gastrointestinal pharmacotherapy of neurodegenerative diseases associated with dopamine deficiency.

Pisa syndrome: Pathophysiology, physical rehabilitation and falls risk

BACKGROUND

Pisa syndrome (PS) is a postural disorder characterised by lateral flexion of the spine (> 10°), predisposing the affected individuals to falls, and contributing to increased mortality in neurodegenerative diseases.

OBJECTIVE

An overview of currently applied therapeutic management options, primarily focused on specifically structured rehabilitation exercises, in conjunction with falls-risk assessment in the individuals affected by PS.

METHODS

A narrative literature review, augmented with the authors' own experience in physical rehabilitation management.

RESULTS

As individuals affected by PS are evidenced to be intrinsically exposed to higher falls-risk through acquired postural deformities, they often fall victims of traumatic accidents, occasionally also facing relocation into 24-hour nursing facilities due to the injuries sustained/resultant disability, consequently having overall quality of their life appreciably reduced.

CONCLUSIONS

sA comprehensive approach is postulated in designing optimal therapeutic management, comprised of the exercises controlling postural stability, whilst reducing lower back pain, and the ones also promoting specific skills essential for coping unassisted after an accidental fall effectively. Rehabilitation of individuals affected by PS should be a fully integrated service, eliminating all identified risk factors for falls. As clinical PS symptoms tend to recur after completion of a full course of therapeutic management, all PS patients should continue the pursuit of therapeutic exercises on an individual basis, to effectively retard their recurrence. In view of overall scarcity of clinical studies completed on the large population samples of PS patients, further in-depth research is still required to ensure higher credence to overall efficacy of the presently proposed therapeutic solutions.