Alzheimer's Disease and Neurotransmission Gene Variants: Focus on Their Effects on Psychiatric Comorbidities and Inflammatory Parameters

"The Dynamic Nature of Being a Person": An Ethnographic Study of People Living With Dementia in Their Communities

BACKGROUND AND OBJECTIVES

A dementia diagnosis can affect social interactions. This study aims to understand how people living with dementia act as social beings within everyday interactions in their local communities.

RESEARCH DESIGN AND METHODS

Focused ethnography informed by Spradley's approach to data collection and analysis. Observations in community spaces.

RESULTS

Twenty-nine observations were undertaken in everyday social settings with 11 people with dementia who were part of a longitudinal interview study. Data consisted of 40 hr of observation, and researcher field notes. The overarching theme "the dynamic nature of being a person" encapsulates participants' exhibited experiences in negotiating to attain and sustain an acknowledged place in their communities. Two subthemes characterized contexts and actions: (1) "Being me-not dementia": Participants constructed narratives to assert their ontological presence in social settings. They and others used strategies to mediate cognitive changes evidencing dementia. (2) "Resisting or acquiescing to 'being absent in place'": Participants were often able to resist being absent to the gaze from others, but some social structures and behaviors led to a person being "in place," yet not having their presence confirmed.

DISCUSSION AND IMPLICATIONS

People living with dementia can actively draw on personal attributes, familiar rituals, objects, and social roles to continue to present themselves as social beings. Identifying how postdiagnosis people may self-manage cognitive changes to retain their presence as a person can help health and social care practitioners and families collaborate with the person living with dementia enabling them to have a continued social presence.

Extemporaneous combination of donepezil and memantine to treat dementia in Alzheimer disease: evidence from Italian real-world data

OBJECTIVE

Providing evidence on donepezil and memantine administration as extemporaneous combination (DM-EXT) to treat Alzheimer Disease (AD) in Italy, and describing demographic and clinical features of AD patients prescribed DM-EXT.

METHODS

Retrospective observational study using IQVIA Italian LifeLink Treatment Dynamics (LRx) and Longitudinal Patient Database (LPD). Prevalent users of DM-EXT were identified on the databases (cohorts DMp_LRx and DMp_LPD) including patients with donepezil and memantine overlapping prescriptions during the selection period (DMp_LRx: "July 2018-June 2021"; DMp_LPD: "July 2012-June 2021"). Demographic and clinical profiles of patients were provided. Starting from cohort DMp_LPD, new users of DM-EXT were selected to calculate treatment adherence. Three additional cohorts of prevalent users of DM-EXT were identified on IQVIA LRx over subsequent 12-month periods, from July 2018 to June 2021, to get national-level yearly estimates accounting for database representativeness.

RESULTS

Cohorts DMp_LRx and DMp_LPD included 9862 and 708 patients, respectively. For both cohorts, two-third of patients were female, and more than half were aged 80+. Concomitant conditions and co-treatments prevalence was very high; most frequent comorbidities included psychiatric and cardiovascular diseases. An intermediate-to-high adherence was observed in 57% of DM-EXT new users. National-level yearly estimates showed an increasing trend (+4%) in DM-EXT prescription, which led to estimate about 10,000 patients being treated during the period "July 2020-June 2021".

CONCLUSIONS

Prescription of DM-EXT is a common practice in Italy. Because the administration of fixed-dose (FDCs) instead of extemporaneous combinations improves treatment adherence, the introduction of an FDC containing donepezil and memantine might enhance AD patients' management and reduce caregiver burden.

Effect of Catechol-O-Methyltransferase Genotype Polymorphism on Neurological and Psychiatric Disorders: Progressing Towards Personalized Medicine

Different polymorphisms of the catechol-O-methyltransferase (COMT) gene affect the COMT enzyme activity. The COMT enzyme plays a major role in the pathophysiology of various neurological and psychiatric disorders. This review article aims to discuss what recent research has discovered about the association of COMT genotype polymorphism with neurological and psychiatric disorders and the scope for the knowledge to be applied for advancement in therapeutics. We searched PubMed and Google Scholar databases and found 1656 articles. We included observational studies, clinical trials, and meta-analyses in the English language published between 2019 and 2021. We screened the articles based on the title and the abstract and found 26 relevant articles. Diseases or conditions studied primarily were schizophrenia, Parkinson’s disease, Alzheimer’s disease, substance use, and depression. This article highlights how genetics influences the susceptibility of an individual to neurological and psychiatric diseases and the variations in the specific symptoms of those diseases. The review showed that the variability in individual response to therapeutic interventions stems from the gene level. This knowledge can contribute towards the dawn of a new era of personalized medicine.

Associations of particulate matter with dementia and mild cognitive impairment in China: A multicenter cross-sectional study

Ambient air pollution has been shown to be associated with the pathogenesis of dementia and mild cognitive impairment (MCI). However, few studies have examined these associations in well-characterized populations with low residential mobility, similar living habits, and a standardized assessment of both air pollution exposure and clinical outcome. This study examined the associations of long-term exposure to particulate matter (PM) air pollution with dementia and MCI, using data from the Chinese Veteran Clinical Research Platform. The cognitive function of elderly veterans from 277 communities in 18 Chinese cities was examined. Participants' daily exposures to aerodynamic diameters ≤2.5 μm (PM_2.5) and ≤10 μm (PM₁₀) during the 3 years prior to the survey were estimated using a satellite-based prediction. The adjusted odds ratios (ORs) and 95% confidence intervals of MCI associated with each 10 μg/m³ increase in PM_2.5 and PM₁₀ were 1.52 (1.39, 1.67) and 1.04 (1.00, 1.08), and those of dementia associated with PM_2.5 and PM₁₀ were 1.27 (1.11, 1.46) and 1.13 (1.05, 1.21), respectively. This demonstrates that long-term exposure to PM_2.5 and PM₁₀ can increase the prevalence of dementia/MCI among veterans in China. Higher ORs were observed for those with ≤9 years of educational attainment, those who actively attended physical activities, those who never smoked, former drinkers, and those who did not suffer from cerebral infarction. Improvement of ambient air quality, especially decreasing levels of PM_2.5, may help to decrease the risk of dementia/MCI. Given the statistically significant association between PM and cognitive impairment demonstrated here, future studies should focus on examining the causal effect of PM pollution on dementia and MCI.

In vitro monitoring of HTR2A-positive neurons derived from human-induced pluripotent stem cells

The serotonin 5-HT_2A receptor (5-HT_2AR) has been receiving increasing attention because its genetic variants have been associated with a variety of neurological diseases. To elucidate the pathogenesis of the neurological diseases associated with 5-HT_2AR gene (HTR2A) variants, we have previously established a protocol to induce HTR2A-expressing neurons from human-induced pluripotent stem cells (hiPSCs). Here, we investigated the maturation stages and electrophysiological properties of HTR2A-positive neurons induced from hiPSCs and constructed an HTR2A promoter-specific reporter lentivirus to label the neurons. We found that neuronal maturity increased over time and that HTR2A expression was induced at the late stage of neuronal maturation. Furthermore, we demonstrated successful labelling of the HTR2A-positive neurons, which had fluorescence and generated repetitive action potentials in response to depolarizing currents and an inward current during the application of TCB-2, a selective agonist of 5-HT_2ARs, respectively. These results indicated that our in vitro model mimicked the in vivo dynamics of 5-HT_2AR. Therefore, in vitro monitoring of the function of HTR2A-positive neurons induced from hiPSCs could help elucidate the pathophysiological mechanisms of neurological diseases associated with genetic variations of the HTR2A gene.

The plasma peptides of Alzheimer's disease

Background

A practical strategy to discover proteins specific to Alzheimer’s dementia (AD) may be to compare the plasma peptides and proteins from patients with dementia to normal controls and patients with neurological conditions like multiple sclerosis or other diseases. The aim was a proof of principle for a method to discover proteins and/or peptides of plasma that show greater observation frequency and/or precursor intensity in AD. The endogenous tryptic peptides of Alzheimer’s were compared to normals, multiple sclerosis, ovarian cancer, breast cancer, female normal, sepsis, ICU Control, heart attack, along with their institution-matched controls, and normal samples collected directly onto ice.

Methods

Endogenous tryptic peptides were extracted from blinded, individual AD and control EDTA plasma samples in a step gradient of acetonitrile for random and independent sampling by LC–ESI–MS/MS with a set of robust and sensitive linear quadrupole ion traps. The MS/MS spectra were fit to fully tryptic peptides within proteins identified using the X!TANDEM algorithm. Observation frequency of the identified proteins was counted using SEQUEST algorithm. The proteins with apparently increased observation frequency in AD versus AD Control were revealed graphically and subsequently tested by Chi Square analysis. The proteins specific to AD plasma by Chi Square with FDR correction were analyzed by the STRING algorithm. The average protein or peptide log₁₀ precursor intensity was compared across disease and control treatments by ANOVA in the R statistical system.

Results

Peptides and/or phosphopeptides of common plasma proteins such as complement C2, C7, and C1QBP among others showed increased observation frequency by Chi Square and/or precursor intensity in AD. Cellular gene symbols with large Chi Square values (χ2 ≥ 25, p ≤ 0.001) from tryptic peptides included KIF12, DISC1, OR8B12, ZC3H12A, TNF, TBC1D8B, GALNT3, EME2, CD1B, BAG1, CPSF2, MMP15, DNAJC2, PHACTR4, OR8B3, GCK, EXOSC7, HMGA1 and NT5C3A among others. Similarly, increased frequency of tryptic phosphopeptides were observed from MOK, SMIM19, NXNL1, SLC24A2, Nbla10317, AHRR, C10orf90, MAEA, SRSF8, TBATA, TNIK, UBE2G1, PDE4C, PCGF2, KIR3DP1, TJP2, CPNE8, and NGF amongst others. STRING analysis showed an increase in cytoplasmic proteins and proteins associated with alternate splicing, exocytosis of luminal proteins, and proteins involved in the regulation of the cell cycle, mitochondrial functions or metabolism and apoptosis. Increases in mean precursor intensity of peptides from common plasma proteins such as DISC1, EXOSC5, UBE2G1, SMIM19, NXNL1, PANO, EIF4G1, KIR3DP1, MED25, MGRN1, OR8B3, MGC24039, POLR1A, SYTL4, RNF111, IREB2, ANKMY2, SGKL, SLC25A5, CHMP3 among others were associated with AD. Tryptic peptides from the highly conserved C-terminus of DISC1 within the sequence MPGGGPQGAPAAAGGGGVSHRAGSRDCLPPAACFR and ARQCGLDSR showed a higher frequency and highest intensity in AD compared to all other disease and controls.

Conclusion

Proteins apparently expressed in the brain that were directly related to Alzheimer’s including Nerve Growth Factor (NFG), Sphingomyelin Phosphodiesterase, Disrupted in Schizophrenia 1 (DISC1), the cell death regulator retinitis pigmentosa (NXNl1) that governs the loss of nerve cells in the retina and the cell death regulator ZC3H12A showed much higher observation frequency in AD plasma vs the matched control. There was a striking agreement between the proteins known to be mutated or dis-regulated in the brains of AD patients with the proteins observed in the plasma of AD patients from endogenous peptides including NBN, BAG1, NOX1, PDCD5, SGK3, UBE2G1, SMPD3 neuronal proteins associated with synapse function such as KSYTL4, VTI1B and brain specific proteins such as TBATA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12014-021-09320-2.