Impact of the COVID-19 pandemic on mortality and loss to follow-up among patients with dementia receiving anti-dementia medications.

The coronavirus disease 2019 (COVID-19) pandemic has profoundly impacted vulnerable groups, such as patients with dementia. We examined changes in mortality and loss to follow-up in patients with dementia using data from the Korean National Health Insurance Service research database. Patients with dementia who visited a medical institution with a recorded dementia-related diagnostic code, including Alzheimer's disease, and who received anti-dementia medication between February 2018 and January 2020 were included in this study. We divided patients with dementia receiving anti-dementia medications into two cohorts: those newly diagnosed with dementia between February 2018 and January 2019 (n = 62,631) and those diagnosed between February 2019 and January 2020 (n = 54,494). Then, we conducted a one-year follow-up of their records, tracking the cohort diagnosed between February 2018 and January 2019 from February 2019 to January 2020, as well as the cohort diagnosed between February 2019 and January 2020 from February 2020 to January 2021. There was a significant increase in follow-up loss among patients newly diagnosed with dementia during the COVID-19 outbreak, from 42.04% in 2019 to 45.89% in 2020. Female sex, younger age, fewer comorbidities, diagnosis of dementia at the Department of Neurology or Psychiatry, and higher income were associated with decreased follow-up loss and mortality. This study highlights the importance of paying extra attention to patients with dementia receiving anti-dementia medications, particularly during pandemics, given their increased risk of loss to follow-up.

Hypointense signal lesion on susceptibility-weighted imaging as a potential indicator of vertebral artery dissection in medullary infarction.

Vertebral artery dissection (VAD) is often associated with medullary infarction; however, an underlying cause may be underestimated. This study aimed to assess the diagnostic potential of hypointense signal lesions along the arterial pathways using susceptibility-weighted imaging (SWI) as a feasible indicator of VAD in medullary infarction. A retrospective analysis was conducted using clinical data, brain magnetic resonance imaging, and angiography records of 79 patients diagnosed with medullary infarction between January 2014 and December 2021. Patients were categorized into an angiography-confirmed dissection group and a non-dissection group based on imaging findings. A new possible dissection group was identified using SWI, including cases with hypointense signals along the arteries without calcification or cardioembolism. We compared the clinical characteristics of the two groups before and after the addition of the hypointense signal as a marker of VAD. The angiography-confirmed dissection group included 12 patients (15%). Among patients lacking angiographic VAD evidence, 14 subjects displayed hypointense signals on SWI: nine patients along the vertebral artery and five subjects at the posterior inferior cerebellar artery without calcification or cardioembolism. The newly classified dissection group was younger, had a lower prevalence of diabetes mellitus and stroke history, and revealed increased headaches compared to the non-dissection group. Hypointense signal detection on SWI in medullary infarctions shows promise as a diagnostic indicator for VAD. Suspicion of VAD is needed when the hypointense signal on SWI is noted, and considering different treatment strategies with angiographic follow-up will be helpful.

GV1001 reduces neurodegeneration and prolongs lifespan in 3xTg-AD mouse model through anti-aging effects.

GV1001, which mimics the activity of human telomerase reverse transcriptase, protects neural cells from amyloid beta (Aß) toxicity and other stressors through extra-telomeric function, as noted in our prior in vitro studies. As per a recent phase II clinical trial, it improves cognitive function in patients with moderate to severe dementia. However, the underlying protective mechanisms remain unclear. This study aimed to investigate the effects of GV1001 on neurodegeneration, senescence, and survival in triple transgenic Alzheimer's disease (3xTg-AD) mice. GV1001 (1 mg/kg) was subcutaneously injected into old 3xTg-AD mice thrice a week until the endpoint for sacrifice, and survival was analysed. Magnetic resonance imaging (MRI) and Prussian blue staining (PBS) were performed to evaluate entry of GV1001 entrance into the brain. Diverse molecular studies were performed to investigate the effect of GV1001 on neurodegeneration and cellular senescence in AD model mice, with a particular focus on BACE, amyloid beta1-42 (Aß1-42), phosphorylated tau, volume of dentate gyrus, ß-galactosidase positive cells, telomere length, telomerase activity, and ageing-associated proteins. GV1001 crossed the blood-brain barrier, as confirmed by assessing the status of ferrocenecarboxylic acid-conjugated GV1001 using magnetic resonance imaging and PBS. GV1001 increased the survival of 3xTg-AD mice. It decreased BACE and Aß1-42 levels, neurodegeneration (i.e., reduced CA1, CA3 and dentate gyrus volume, decreased levels of senescence-associated ß-galactosidase positive cells, and increased telomere length and telomerase activity), and levels of ageing-associated proteins. We suggest that GV1001 exerts anti-ageing effects in 3xTg-AD mice by reducing neurodegeneration and senescence, which contributes to improved survival.

GV1001 modulates neuroinflammation and improves memory and behavior through the activation of gonadotropin-releasing hormone receptors in a triple transgenic Alzheimer's disease mouse model.

GV1001 protects neural cells from amyloid-ß (Aß) toxicity and other stressors in in vitro studies and demonstrates clinically beneficial effects in patients with moderate to severe Alzheimer's disease (AD). Here, we investigated the protective effects and mechanism of action of GV1001 in triple transgenic AD (3xTg-AD) mice. We found that GV1001 improved memory and cognition in middle- and old-aged 3xTg-AD mice. Additionally, it reduced Aß oligomer and phospho-tau (Ser202 and Thr205) levels in the brain, and mitigated neuroinflammation by promoting a neuroprotective microglial and astrocyte phenotype while diminishing the neurotoxic ones. In vitro, GV1001 bound to gonadotropin releasing hormone receptors (GnRHRs) with high affinity. Levels of cyclic adenosine monophosphate, a direct downstream effector of activated GnRHRs, increased after GV1001 treatment. Furthermore, inhibition of GnRHRs blocked GV1001-induced effects. Thus, GV1001 might improve cognitive and memory functions of 3xTg-AD mice by suppressing neuroinflammation and reducing Aß oligomers levels and phospho-tau by activating GnRHRs and their downstream signaling pathways.

Predicting amyloid PET positivity using plasma p-tau181 and other blood-based biomarkers.

Introduction: This study aimed to determine the efficacy of combining plasma phosphorylated tau (p-tau)181, amyloid beta (Aß)42/Aß40, neurofilament light (NfL), and apolipoprotein E (APOE) genotypes for detecting positive amyloid positron emission tomography (PET), which is little known in the Asian population, in two independent cohorts. Methods: Biomarkers were measured using a single-molecule array (Simoa) in a cohort study (Asan). All participants underwent amyloid PET. Significant changes in the area under the curve (AUC) and Akaike Information Criterion values were considered to determine the best model. The generalizability of this model was tested using another cohort (KBASE-V). Results: In the Asan cohort, after adjusting for age and sex, p-tau181 (AUC = 0.854) or APOE ε4 status (AUC = 0.769) distinguished Aß status with high accuracy. Combining them or adding NfL and Aß42/40 improved model fitness. The best-fit model included the plasma p-tau181, APOE ε4, NfL and Aß42/40. The models established from the Asan cohort were tested in the KBASE-V cohort. Additionally, in the KBASE-V cohort, these three biomarker models had similar AUC in cognitively unimpaired (AUC = 0.768) and mild cognitive impairment (MCI) (AUC = 0.997) participants. Conclusions: Plasma p-tau181 showed a high performance in determining Aß-PET positivity. Adding plasma NfL and APOE ε4 status improved the model fit without significant improvement in AUC.

Effects of GV1001 on Language Dysfunction in Patients With Moderate-to-Severe Alzheimer's Disease: Post Hoc Analysis of Severe Impairment Battery Subscales.

Background and Purpose: The efficacy and safety of GV1001 have been demonstrated in patients with moderate-to-severe Alzheimer's disease (AD). In this study, we aimed to further demonstrate the effectiveness of GV1001 using subscales of the Severe Impairment Battery (SIB), which is a validated measure to assess cognitive function in patients with moderate-to-severe AD. Methods: We performed a post hoc analysis of data from a 6 month, multicenter, phase 2, randomized, double-blind, placebo-controlled trial with GV1001 (ClinicalTrials.gov, NCT03184467). Patients were randomized to receive either GV1001 or a placebo for 24 weeks. In the current study, nine subscales of SIB-social interaction, memory, orientation, language, attention, praxis, visuospatial ability, construction, and orientation to name- were compared between the treatment (GV1001 1.12 mg) and placebo groups at weeks 12 and 24. The safety endpoints for these patients were also determined based on adverse events. Results: In addition to the considerable beneficial effect of GV1001 on the SIB total score, GV1001 1.12 mg showed the most significant effect on language function at 24 weeks compared to placebo in both the full analysis set (FAS) and per-protocol set (PPS) (p=0.017 and p=0.011, respectively). The rate of adverse events did not differ significantly between the 2 groups. Conclusions: Patients with moderate-to-severe AD receiving GV1001 had greater language benefits than those receiving placebo, as measured using the SIB language subscale.

Inhibition of the NLRP3 Inflammasome Activation/Assembly through the Activation of the PI3K Pathway by Naloxone Protects Neural Stem Cells from Ischemic Condition.

Naloxone is a well-known opioid antagonist and has been suggested to have neuroprotective effects in cerebral ischemia. We investigated whether naloxone exhibits anti-inflammatory and neuroprotective effects in neural stem cells (NSCs) injured by oxygen-glucose deprivation (OGD), whether it affects the NOD-like receptor protein 3 (NLRP3) inflammasome activation/assembly, and whether the role of the phosphatidylinositol 3-kinase (PI3K) pathway is important in the control of NLRP3 inflammasome activation/assembly by naloxone. Primary cultured NSCs were subjected to OGD and treated with different concentrations of naloxone. Cell viability, proliferation, and the intracellular signaling proteins associated with the PI3K pathway and NLRP3 inflammasome activation/assembly were evaluated in OGD-injured NSCs. OGD significantly reduced survival, proliferation, and migration and increased apoptosis of NSCs. However, treatment with naloxone significantly restored survival, proliferation, and migration and decreased apoptosis of NSCs. Moreover, OGD markedly increased NLRP3 inflammasome activation/assembly and cleaved caspase-1 and interleukin-1ß levels in NSCs, but naloxone significantly attenuated these effects. These neuroprotective and anti-inflammatory effects of naloxone were eliminated when cells were treated with PI3K inhibitors. Our results suggest that NLRP3 inflammasome is a potential therapeutic target and that naloxone reduces ischemic injury in NSCs by inhibiting NLRP3 inflammasome activation/assembly mediated by the activation of the PI3K signaling pathway.

DKK3 expression is associated with immunosuppression and poor prognosis in glioblastoma, in contrast to lower-grade gliomas.

PURPOSE: We previously reported that expression of dickkopf-3 (DKK3), which is involved in the Wnt/ß-catenin pathway, is significantly associated with prognosis in patients with glioblastoma multiforme (GBM). The aim of this study was to compare the association of DKK3 with other Wnt/ß-catenin pathway-related genes and immune responses between lower grade glioma (LGG) and GBM. METHODS: We obtained the clinicopathological data of 515 patients with LGG (World Health Organization [WHO] grade II and III glioma) and 525 patients with GBM from the Cancer Genome Atlas (TCGA) database. We performed Pearson's correlation analysis to investigate the relationships between Wnt/ß-catenin-related gene expression in LGG and GBM. Linear regression analysis was performed to identify the association between DKK3 expression and immune cell fractions in all grade II to IV gliomas. RESULTS: A total of 1,040 patients with WHO grade II to IV gliomas were included in the study. As the grade of glioma increased, DKK3 showed a tendency to be more strongly positively correlated with the expression of other Wnt/ß-catenin pathway-related genes. DKK3 was not associated with immunosuppression in LGG but was associated with downregulation of immune responses in GBM. We hypothesized that the role of DKK3 in the Wnt/ß-catenin pathway might be different between LGG and GBM. CONCLUSION: According to our findings, DKK3 expression had a weak effect on LGG but a significant effect on immunosuppression and poor prognosis in GBM. Therefore, DKK3 expression seems to play different roles, through the Wnt/ß-catenin pathway, between LGG and GBM.

Chronic hypoxia of endothelial cells boosts HIF-1α-NLRP1 circuit in Alzheimer's disease.

Cerebral microvasculature of patients with Alzheimer's disease (AD) exhibits reduced capillary diameter and impaired blood flow. Molecular mechanisms of ischemic vessels affecting AD progressions have not been well established yet. In the present study, we found that in vivo triple (PS1M146V, APPswe, tauP301L) transgenic AD mouse model (3x-Tg AD) brains and retinas showed hypoxic vessels expressing hypoxyprobe and hypoxia inducible factor-1α (HIF-1α). To mimic in vivo hypoxic vessels, we used in vitro oxygen-glucose deprivation (OGD)-treated endothelial cells. HIF-1α protein was increased through reactive oxygen species (ROS) producing NADPH oxidases (NOX) (i.e., Nox2, Nox4). OGD-induced HIF-1α upregulated Nox2 and Nox4, demonstrating crosstalk between HIF-1α and NOX (i.e., Nox2, Nox4). Interestingly, NLR family pyrin domain containing 1 (NLRP1) protein was promoted by OGD, and such effect was blocked by downregulation of Nox4 and HIF-1α. Knockdown of NLRP1 also diminished OGD-mediated protein levels of Nox2, Nox4, and HIF-1α in human brain microvascular endothelial cells. These results showed interplay among HIF-1α, Nox4 and NLRP1 in OGD-treated endothelial cells. Expression of NLRP3 was not detected well in hypoxic endothelial cells of 3x-Tg AD retinas or OGD-treated endothelial cells. Instead, hypoxic endothelial cells of 3x-Tg AD brains and retinas markedly expressed NLRP1, the adaptor molecule apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and interleukin-1ß (IL-1ß). Taken together, our results suggest that AD brains and retinas can trigger chronic hypoxia especially in microvascular endothelial cells, consequently leading to NLRP1 inflammasome formation and upregulation of ASC-caspase-1-IL-1ß cascades. In addition, NLRP1 can stimulate HIF-1α expression and form HIF-1α-NLRP1 circuit. These consequences might further destroy vascular system in AD.

Predicting cognitive stage transition using p-tau181, Centiloid, and other measures.

BACKGROUND: A combination of plasma phospho-tau (p-tau), amyloid beta (Aß)-positron emission tomography (PET), brain magnetic resonance imaging, cognitive function tests, and other biomarkers might predict future cognitive decline. This study aimed to investigate the efficacy of combining these biomarkers in predicting future cognitive stage transitions within 3 years. METHODS: Among the participants in the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease (KBASE-V) study, 49 mild cognitive impairment (MCI) and 113 cognitively unimpaired (CU) participants with Aß-PET and brain imaging data were analyzed. RESULTS: Older age, increased plasma p-tau181, Aß-PET positivity, and decreased semantic fluency were independently associated with cognitive stage transitions. Combining age, p-tau181, the Centiloid scale, semantic fluency, and hippocampal volume produced high predictive value in predicting future cognitive stage transition (area under the curve = 0.879). CONCLUSIONS: Plasma p-tau181 and Centiloid scale alone or in combination with other biomarkers, might predict future cognitive stage transition in non-dementia patients. HIGHLIGHTS: -Plasma p-tau181 and Centiloid scale might predict future cognitive stage transition. -Combining them or adding other biomarkers increased the predictive value. -Factors that independently associated with cognitive stage transition were demonstrated.

Long Sleep Duration and Dissatisfaction with Sleep Quality Are Associated with Ischemic Stroke in Young Patients.

INTRODUCTION: Suboptimal sleep duration and poor sleep quality have been proposed to increase stroke risk. However, their significance in young ischemic stroke is unclear. We aimed to investigate the importance of sleep duration and quality on young ischemic stroke patients. METHODS: A multicenter matched case-control study was performed to evaluate under-recognized risk factors in young (<45 years) ischemic stroke patients in 8 tertiary hospitals in Korea. A total of 225 patients and 225 age- and sex-matched controls were enrolled in the same period. Detailed information about patients' demographics, socioeconomic state, and traditional and nontraditional risk factors including sleep-related factors were obtained using structured questionnaires. Risk of ischemic stroke was estimated using conditional logistic regression analysis. RESULTS: Although average sleep duration was similar in patients and controls, patients were more likely to have long (≥9 h) or extremely short (<5 h) sleep durations. In addition, the proportion of subjects with dissatisfaction with sleep quality was higher in patients than controls (66.2 vs. 49.3%, p < 0.001). In multivariable conditional logistic regression analysis, long sleep duration (OR: 11.076, 95% CI: 1.819-67.446, p = 0.009) and dissatisfaction with sleep quality (OR: 2.116, 95% CI: 1.168-3.833, p = 0.013) were independently associated with risk of ischemic stroke. CONCLUSIONS: Long sleep duration and dissatisfaction with sleep quality may be associated with increased risk of ischemic stroke in young adults. Improving sleep habit or quality could be important for reducing the risk of ischemic stroke.

Relationship between telomere shortening and early subjective depressive symptoms and cognitive complaints in older adults.

Telomere length (TL) has been reported to be associated with depression and cognitive impairment in elderly. Early detection of depression and cognitive impairment is important to delay disease progression. Therefore, we aimed to identify whether TL is associated with early subjective depressive symptoms and cognitive complaints among healthy elderly subjects. This study was a multicenter, outcome assessor-blinded, 24-week, randomized controlled trial (RCT). Measurement of questionnaire and physical activity scores and blood sample analyses were performed at baseline and after six months of follow-up in all study participants. Linear regression analyses were performed to identify whether early subjective depressive symptoms, cognitive complaints, and several blood biomarkers are associated with TL. Altogether, 137 relatively healthy elderly individuals (60-79 years old) were enrolled in this prospective RCT. We observed an approximate decrease of 0.06 and 0.11-0.14 kbps of TL per one point increase in the geriatric depression scale and cognitive complaint interview scores, respectively, at baseline and after six months of follow-up. We also found an approximate decrease of 0.08-0.09 kbps of TL per one point increase in interleukin (IL)-6 levels at baseline and after six months of follow-up. Our study showed that both early subjective depressive symptoms and cognitive complaints were associated with a relatively shorter TL in relatively healthy elderly individuals. In addition, based on our findings, we believe that IL-6 plays an important role in the relationship between shortening TL and early subjective depressive symptoms and cognitive complaints.

Anti-N-methyl-D-aspartate receptor encephalitis after coronavirus disease 2019: A case report and literature review.

RATIONALE: Coronavirus disease 2019 (COVID-19) has become a global pandemic and COVID-19-associated anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis may occur through an immune-mediated pathomechanism. PATIENT CONCERNS: A 21-year-old woman with a history of COVID-19 presented to our hospital with memory decline and psychiatric symptoms. DIAGNOSIS: The patient was diagnosed with anti-NMDAR encephalitis. INTERVENTION: Intravenous methylprednisolone (1 g/day over 5 days) followed by immunoglobulin (0.4 g/kg/day over 5 days) were administered. The patient underwent laparoscopic salpingo-oophorectomy to remove an ovarian teratoma. OUTCOMES: The patient was discharged with sequelae of short-term memory impairment, without other neuropsychiatric symptoms. LESSONS: Cases of previously reported anti-NMDAR encephalitis with COVID-19 were reviewed and compared with the present case. Clinicians should be aware of the occurrence of anti-NMDAR encephalitis in patients who present with neuropsychiatric complaints during or after exposure to COVID-19. Further studies are required to determine the causal relationship between the 2 diseases and predict the prognosis of anti-NMDAR encephalitis after COVID-19 exposure.

Differential expression of aqueous humor microRNAs in central retinal vein occlusion and its association with matrix metalloproteinases: a pilot study.

The aim of this study is to investigate the differential expression of microRNAs (miRNAs) in the aqueous humor (AH) of patients with central retinal vein occlusion (CRVO), and their association with AH matrix metalloproteinase (MMP) activity. Eighteen subjects, including 10 treatment naïve patients with CRVO and 8 control subjects, scheduled for intravitreal injection and cataract surgery, respectively, were included. AH samples were collected at the beginning of the procedure. A microarray composed of 84 miRNAs was performed to identify differentially expressed miRNAs in CRVO AH, which were further analyzed using bioinformatic tools to identify directly related cytokines/proteins. Eight miRNAs (hsa-mir-16-5p, hsa-mir-142-3p, hsa-mir-19a-3p, hsa-mir-144-3p, hsa-mir-195-5p, hsa-mir-17-5p, hsa-mir-93-5p, and hsa-mir-20a-5p) were significantly downregulated in the CRVO group. Bioinformatic analysis revealed a direct relationship among downregulated miRNAs, CRVO, and the following proteins: MMP-2, MMP-9, tumor necrosis factor, transforming growth factor beta-1, caspase-3, interleukin-6, interferon gamma, and interleukin-1-beta. Activities of MMP-2 and -9 in AH were detected using gelatin zymography, showing significant increase in the CRVO group compared to the control group (p < 0.01). This pilot study first revealed that MMP-2 and -9 were directly related to downregulated miRNAs and showed significant increase in activity in AH of patients with CRVO. Therefore, the relevant miRNAs and MMPs in AH could serve as potential biomarkers or therapeutic targets for CRVO.

Is Telomere Length Shortening a Risk Factor for Neurodegenerative Disorders?

Telomeres are located at the end of chromosomes. They are known to protect chromosomes and prevent cellular senescence. Telomere length shortening has been considered an important marker of aging. Many studies have reported this concept in connection with neurodegenerative disorders. Considering the role of telomeres, it seems that longer telomeres are beneficial while shorter telomeres are detrimental in preventing neurodegenerative disorders. However, several studies have shown that people with longer telomeres might also be vulnerable to neurodegenerative disorders. Before these conflicting results can be explained through large-scale longitudinal clinical studies on the role of telomere length in neurodegenerative disorders, it would be beneficial to simultaneously review these opposing results. Understanding these conflicting results might help us plan future studies to reveal the role of telomere length in neurodegenerative disorders. In this review, these contradictory findings are thoroughly discussed, with the aim to better understand the role of telomere length in neurodegenerative disorders.

Identification of genes from ten oncogenic pathways associated with mortality and disease progression in glioblastoma.

Glioblastoma multiforme (GBM) is the most malignant brain tumor with an extremely poor prognosis. The Cancer Genome Atlas (TCGA) database has been used to confirm the roles played by 10 canonical oncogenic signaling pathways in various cancers. The purpose of this study was to evaluate the expression of genes in these 10 canonical oncogenic signaling pathways, which are significantly related to mortality and disease progression in GBM patients. Clinicopathological information and mRNA expression data of 525 patients with GBM were obtained from TCGA database. Gene sets related to the 10 oncogenic signaling pathways were investigated via Gene Set Enrichment Analysis. Multivariate Cox regression analysis was performed for all the genes significantly associated with mortality and disease progression for each oncogenic signaling pathway in GBM patients. We found 12 independent genes from the 10 oncogenic signaling pathways that were significantly related to mortality and disease progression in GBM patients. Considering the roles of these 12 significant genes in cancer, we suggest possible mechanisms affecting the prognosis of GBM. We also observed that the expression of 6 of the genes significantly associated with a poor prognosis of GBM, showed negative correlations with CD8+ T-cells in GBM tissue. Using a large-scale open database, we identified 12 genes belonging to 10 well-known oncogenic canonical pathways, which were significantly associated with mortality and disease progression in patients with GBM. We believe that our findings will contribute to a better understanding of the mechanisms underlying the pathophysiology of GBM in the future.