Mounting evidence indicates that a physiological function of amyloid-β (Aβ) is to mediate neural activity-dependent homeostatic and competitive synaptic plasticity in the brain. I have previously summarized the lines of evidence supporting this hypothesis and highlighted the similarities between Aβ and anti-microbial peptides in mediating cell/synapse competition. In cell competition, anti-microbial peptides deploy a multitude of mechanisms to ensure both self-protection and competitor elimination. Here I review recent studies showing that similar mechanisms are at play in Aβ-mediated synapse competition and perturbations in these mechanisms underpin Alzheimer’s disease (AD). Specifically, I discuss evidence that Aβ and ApoE, two crucial players in AD, co-operate in the regulation of synapse competition. Glial ApoE promotes self-protection by increasing the production of trophic monomeric Aβ and inhibiting its assembly into toxic oligomers. Conversely, Aβ oligomers, once assembled, promote the elimination of competitor synapses via direct toxic activity and amplification of “eat-me” signals promoting the elimination of weak synapses. I further summarize evidence that neuronal ApoE may be part of a gene regulatory network that normally promotes competitive plasticity, explaining the selective vulnerability of ApoE expressing neurons in AD brains. Lastly, I discuss evidence that sleep may be key to Aβ-orchestrated plasticity, in which sleep is not only induced by Aβ but is also required for Aβ-mediated plasticity, underlining the link between sleep and AD. Together, these results strongly argue that AD is a disease of competitive synaptic plasticity gone awry, a novel perspective that may promote AD research.
{"title":"Evidence that Alzheimer’s Disease Is a Disease of Competitive Synaptic Plasticity Gone Awry","authors":"Zhen Huang","doi":"10.3233/jad-240042","DOIUrl":"https://doi.org/10.3233/jad-240042","url":null,"abstract":" Mounting evidence indicates that a physiological function of amyloid-β (Aβ) is to mediate neural activity-dependent homeostatic and competitive synaptic plasticity in the brain. I have previously summarized the lines of evidence supporting this hypothesis and highlighted the similarities between Aβ and anti-microbial peptides in mediating cell/synapse competition. In cell competition, anti-microbial peptides deploy a multitude of mechanisms to ensure both self-protection and competitor elimination. Here I review recent studies showing that similar mechanisms are at play in Aβ-mediated synapse competition and perturbations in these mechanisms underpin Alzheimer’s disease (AD). Specifically, I discuss evidence that Aβ and ApoE, two crucial players in AD, co-operate in the regulation of synapse competition. Glial ApoE promotes self-protection by increasing the production of trophic monomeric Aβ and inhibiting its assembly into toxic oligomers. Conversely, Aβ oligomers, once assembled, promote the elimination of competitor synapses via direct toxic activity and amplification of “eat-me” signals promoting the elimination of weak synapses. I further summarize evidence that neuronal ApoE may be part of a gene regulatory network that normally promotes competitive plasticity, explaining the selective vulnerability of ApoE expressing neurons in AD brains. Lastly, I discuss evidence that sleep may be key to Aβ-orchestrated plasticity, in which sleep is not only induced by Aβ but is also required for Aβ-mediated plasticity, underlining the link between sleep and AD. Together, these results strongly argue that AD is a disease of competitive synaptic plasticity gone awry, a novel perspective that may promote AD research.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140679446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Donghyun Kim, Parivash Jamrasi, Xinxing Li, Soyoung Ahn, Yunho Sung, Seohyun Ahn, Yuseon Kang, Wook Song
Background: Alzheimer-associated neuronal thread protein (AD7c-NTP) has been demonstrated to have high diagnostic accuracy in differentiating Alzheimer’s disease (AD) patients from healthy individuals. However, it is yet unclear whether exercise can lower the level of AD7c-NTP in urine among active Korean elderly. Objective: To assess the effect of exercise on AD7c-ntp levels in urine and cognitive function among active Korean elderly. Methods: In total, 40 Korean elderly (≥65 years) were divided into Active Control group (CG, n = 10), Aerobic exercise group (AG, n = 18), and combined Resistance/Aerobic exercise group (RAG, n = 12). A total of 12 weeks of exercise intervention was implemented. At week 0 and 12, cognitive performance (Korean Mini-Mental State Examination, Korean-Color Word Stroop test), grip strength, and body composition (muscle mass and body fat percentage) were measured. Also, a morning urine sample was obtained from each subject. The level of AD7c-NTP was measured using competitive enzyme-linked immunosorbent assay (ELISA). Results: After 12 weeks of exercise intervention, there was a significant difference of AD7c-NTP levels between RAG and CG (p = 0.026), AG and CG (p = 0.032), respectively. Furthermore, the AD7c-NTP levels in urine showed negative correlation with K-MMSE scores (r = –0.390, p = 0.013) and grip strength (r = –0.376, p = 0.017), among all participants after exercise intervention. Conclusions: This is the first study to investigate urine biomarker through exercise intervention. In future stuides, participants who have low cognitive function and low activity levels need to be recruited to observe more significant ‘Exercise’ effect.
{"title":"Effects of Exercise on Urinary AD7c-NTP (Alzheimer-Associated Neuronal Thread Protein) Levels and Cognitive Function Among Active Korean Elderly: A Randomized Controlled Trial","authors":"Donghyun Kim, Parivash Jamrasi, Xinxing Li, Soyoung Ahn, Yunho Sung, Seohyun Ahn, Yuseon Kang, Wook Song","doi":"10.3233/jad-230946","DOIUrl":"https://doi.org/10.3233/jad-230946","url":null,"abstract":"Background: Alzheimer-associated neuronal thread protein (AD7c-NTP) has been demonstrated to have high diagnostic accuracy in differentiating Alzheimer’s disease (AD) patients from healthy individuals. However, it is yet unclear whether exercise can lower the level of AD7c-NTP in urine among active Korean elderly. Objective: To assess the effect of exercise on AD7c-ntp levels in urine and cognitive function among active Korean elderly. Methods: In total, 40 Korean elderly (≥65 years) were divided into Active Control group (CG, n = 10), Aerobic exercise group (AG, n = 18), and combined Resistance/Aerobic exercise group (RAG, n = 12). A total of 12 weeks of exercise intervention was implemented. At week 0 and 12, cognitive performance (Korean Mini-Mental State Examination, Korean-Color Word Stroop test), grip strength, and body composition (muscle mass and body fat percentage) were measured. Also, a morning urine sample was obtained from each subject. The level of AD7c-NTP was measured using competitive enzyme-linked immunosorbent assay (ELISA). Results: After 12 weeks of exercise intervention, there was a significant difference of AD7c-NTP levels between RAG and CG (p = 0.026), AG and CG (p = 0.032), respectively. Furthermore, the AD7c-NTP levels in urine showed negative correlation with K-MMSE scores (r = –0.390, p = 0.013) and grip strength (r = –0.376, p = 0.017), among all participants after exercise intervention. Conclusions: This is the first study to investigate urine biomarker through exercise intervention. In future stuides, participants who have low cognitive function and low activity levels need to be recruited to observe more significant ‘Exercise’ effect.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140680576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ozde Cetinsoy, Ijeoma Anyanwu, Harikrishnan Krishnanand, Gokulakrishnan Natarajan, Naveen Ramachandran, Alan Thomas, Keeley J. Brookes
Background: The role of the innate immune system has long been associated with Alzheimer’s disease (AD). There is now accumulating evidence that the soluble Urokinase Plasminogen Activator Receptor pathway, and its genes, PLAU and PLAUR may be important in AD, and yet there have been few genetic association studies to explore this. Objective: This study utilizes the DNA bank of the Brains for Dementia Research cohort to investigate the genetic association of common polymorphisms across the PLAU and PLAUR genes with AD. Methods: TaqMan genotyping assays were used with standard procedures followed by association analysis in PLINK. Results: No association was observed between the PLAU gene and AD; however, two SNPs located in the PLAUR gene were indicative of a trend towards association but did not surpass multiple testing significance thresholds. Conclusions: Further genotyping studies and exploration of the consequences of these SNPs on gene expression and alternative splicing are warranted to fully uncover the role this system may have in AD.
背景：长期以来，先天性免疫系统的作用一直与阿尔茨海默病（AD）有关。目前有越来越多的证据表明，可溶性尿激酶原激活剂受体通路及其基因 PLAU 和 PLAUR 可能对阿兹海默症有重要影响，但很少有遗传关联研究对此进行探讨。研究目的本研究利用脑痴呆研究队列的 DNA 库，调查 PLAU 和 PLAUR 基因的常见多态性与 AD 的遗传关联。研究方法采用标准程序进行 TaqMan 基因分型检测，然后在 PLINK 中进行关联分析。结果未观察到 PLAU 基因与 AD 之间存在关联；然而，位于 PLAUR 基因的两个 SNPs 显示出关联趋势，但未超过多重检验显著性阈值。结论有必要进一步开展基因分型研究，并探索这些 SNP 对基因表达和替代剪接的影响，以全面揭示该系统在 AD 中可能扮演的角色。
{"title":"Gene Association Study of the Urokinase Plasminogen Activator and Its Receptor Gene in Alzheimer’s Disease","authors":"Ozde Cetinsoy, Ijeoma Anyanwu, Harikrishnan Krishnanand, Gokulakrishnan Natarajan, Naveen Ramachandran, Alan Thomas, Keeley J. Brookes","doi":"10.3233/jad-231383","DOIUrl":"https://doi.org/10.3233/jad-231383","url":null,"abstract":"Background: The role of the innate immune system has long been associated with Alzheimer’s disease (AD). There is now accumulating evidence that the soluble Urokinase Plasminogen Activator Receptor pathway, and its genes, PLAU and PLAUR may be important in AD, and yet there have been few genetic association studies to explore this. Objective: This study utilizes the DNA bank of the Brains for Dementia Research cohort to investigate the genetic association of common polymorphisms across the PLAU and PLAUR genes with AD. Methods: TaqMan genotyping assays were used with standard procedures followed by association analysis in PLINK. Results: No association was observed between the PLAU gene and AD; however, two SNPs located in the PLAUR gene were indicative of a trend towards association but did not surpass multiple testing significance thresholds. Conclusions: Further genotyping studies and exploration of the consequences of these SNPs on gene expression and alternative splicing are warranted to fully uncover the role this system may have in AD.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140679161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The following commentary discusses a review by Cressot et al. entitled: ‘Psychosis in Neurodegenerative Dementias: A Systematic Comparative Review’. The authors describe the epidemiology and phenomenology of psychosis across neurodegenerative dementias. Dementia with Lewy bodies had the highest reported prevalence of psychosis at 74% followed by Alzheimer’s disease, 54% and frontotemporal degeneration, 42% . Detailed characterization of psychosis shows differences in the types of hallucinations and delusions by dementia type. These findings suggest that different types of dementia related pathology are associated with high rates of psychosis with more specific symptom profiles than previously appreciated. Understanding the differences and variety of psychotic experiences across dementia types may have diagnostic and therapeutic implications for treating hallucinations and delusions in populations suffering from neurodegenerative diseases.
{"title":"Exploring Psychosis in Neurodegenerative Dementia: Connecting Symptoms to Neurobiology","authors":"Christopher B. Morrow, G. Pontone","doi":"10.3233/jad-240328","DOIUrl":"https://doi.org/10.3233/jad-240328","url":null,"abstract":"The following commentary discusses a review by Cressot et al. entitled: ‘Psychosis in Neurodegenerative Dementias: A Systematic Comparative Review’. The authors describe the epidemiology and phenomenology of psychosis across neurodegenerative dementias. Dementia with Lewy bodies had the highest reported prevalence of psychosis at 74% followed by Alzheimer’s disease, 54% and frontotemporal degeneration, 42% . Detailed characterization of psychosis shows differences in the types of hallucinations and delusions by dementia type. These findings suggest that different types of dementia related pathology are associated with high rates of psychosis with more specific symptom profiles than previously appreciated. Understanding the differences and variety of psychotic experiences across dementia types may have diagnostic and therapeutic implications for treating hallucinations and delusions in populations suffering from neurodegenerative diseases.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140680868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: The joint associations of handgrip strength (HGS) weakness and asymmetry with cognitive decline remain understudied in older adults. Objective: To investigate the associations between HGS weakness, asymmetry, and lower cognitive function in a nationally representative sample of older Americans. Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey 2011–2014. Weakness was defined as HGS <26 kg for men and <16 kg for women. Asymmetry was determined by calculating the ratio of dominant to non-dominant HGS. Participants with an HGS ratio <0.90 or >1.10 were classified as having any HGS asymmetry. Those with an HGS ratio >1.10 exhibited dominant HGS asymmetry, while those with an HGS ratio <0.90 displayed nondominant HGS asymmetry, respectively. Lower cognitive functioning was defined as global cognitive composite scores more than 1 standard deviation below the mean. Covariate-adjusted logistic regression models were used to analyze the associations between HGS asymmetry/weakness and lower cognitive functioning. Results: Compared to individuals with non-weak and symmetric HGS, those with any HGS asymmetry alone and weakness alone had 1.017 (95% confidence interval [CI]: 0.707–1.463) and 1.391 (95% CI: 0.542–3.571) greater odds for cognitive decline, while co-occurrence of both HGS asymmetry and weakness was associated with 3.724 (95% CI: 1.711–8.107) greater odds for lower cognitive function after controlling for confounders. Cnclusions: Individuals exhibiting both diminished and asymmetrical HGS demonstrated an elevated susceptibility to cognitive impairment, thereby implying that the inclusion of HGS asymmetry assessment in conjunction with weakness evaluation may enhance the accuracy of prognosticating cognitive decline.
{"title":"Associations of Handgrip Strength Weakness and Asymmetry with Lower Cognitive Function: Results from the National Health and Nutrition Examination Survey (2011–2014)","authors":"Lang Peng, Qingwei Xiang, Yong Zhou, Renyi Yin","doi":"10.3233/jad-231375","DOIUrl":"https://doi.org/10.3233/jad-231375","url":null,"abstract":"Background: The joint associations of handgrip strength (HGS) weakness and asymmetry with cognitive decline remain understudied in older adults. Objective: To investigate the associations between HGS weakness, asymmetry, and lower cognitive function in a nationally representative sample of older Americans. Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey 2011–2014. Weakness was defined as HGS <26 kg for men and <16 kg for women. Asymmetry was determined by calculating the ratio of dominant to non-dominant HGS. Participants with an HGS ratio <0.90 or >1.10 were classified as having any HGS asymmetry. Those with an HGS ratio >1.10 exhibited dominant HGS asymmetry, while those with an HGS ratio <0.90 displayed nondominant HGS asymmetry, respectively. Lower cognitive functioning was defined as global cognitive composite scores more than 1 standard deviation below the mean. Covariate-adjusted logistic regression models were used to analyze the associations between HGS asymmetry/weakness and lower cognitive functioning. Results: Compared to individuals with non-weak and symmetric HGS, those with any HGS asymmetry alone and weakness alone had 1.017 (95% confidence interval [CI]: 0.707–1.463) and 1.391 (95% CI: 0.542–3.571) greater odds for cognitive decline, while co-occurrence of both HGS asymmetry and weakness was associated with 3.724 (95% CI: 1.711–8.107) greater odds for lower cognitive function after controlling for confounders. Cnclusions: Individuals exhibiting both diminished and asymmetrical HGS demonstrated an elevated susceptibility to cognitive impairment, thereby implying that the inclusion of HGS asymmetry assessment in conjunction with weakness evaluation may enhance the accuracy of prognosticating cognitive decline.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140682858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Minjae Kim, Yoo Sung Song, Kyunghwa Han, Yun Jung Bae, Ji Won Han, Ki Woong Kim
Background: Impaired glymphatic flow on the Alzheimer’s disease (AD) spectrum may be evaluated using diffusion tensor image analysis along the perivascular space (DTI-ALPS). Objective: We aimed to validate impaired glymphatic flow and explore its association with gray matter volume, cognitive status, and cerebral amyloid deposition on the AD spectrum. Methods: 80 participants (mean age, 76.9±8.5 years; 57 women) with AD (n = 65) and cognitively normal (CN) (n = 15) who underwent 3T brain MRI including DTI and/or amyloid PET were included. After adjusting for age, sex, apolipoprotein E status, and burden of white matter hyperintensities, the ALPS-index was compared according to the AD spectrum. The association between the ALPS-index and gray matter volume, cognitive status, and quantitative amyloid from PET was assessed. Results: The ALPS-index in the AD was significantly lower (mean, 1.476; 95% CI, 1.395–1.556) than in the CN (1.784;1.615–1.952; p = 0.026). Volumes of the entorhinal cortex, hippocampus, temporal pole, and primary motor cortex showed significant associations with the ALPS-index (all, p < 0.05). There was a positive correlation between the ALPS-index and MMSE score (partial r = 0.435; p < 0.001), but there was no significant correlation between the ALPS-index and amyloid SUVRs (all, p > 0.05). Conclusions: Decreased glymphatic flow measured by DTI-ALPS in AD may serve as a marker of neurodegeneration correlating with structural atrophy and cognitive decline.
背景：阿尔茨海默病（AD）的血流受损情况可通过沿血管周围空间的弥散张量图像分析（DTI-ALPS）进行评估。我们的目标是我们旨在验证受损的甘油三酯流，并探讨其与灰质体积、认知状态和脑淀粉样蛋白沉积之间的关系。方法：纳入80名接受了3T脑MRI（包括DTI和/或淀粉样蛋白PET）检查的AD患者（65人）和认知正常者（15人）（平均年龄76.9±8.5岁，女性57人）。在对年龄、性别、载脂蛋白 E 状态和白质高密度负担进行调整后，根据 AD 频谱对 ALPS 指数进行了比较。评估了ALPS指数与灰质体积、认知状态和PET定量淀粉样蛋白之间的关系。结果显示AD患者的ALPS指数（平均值，1.476；95% CI，1.395-1.556）明显低于CN患者（1.784；1.615-1.952；P = 0.026）。内叶皮层、海马、颞极和初级运动皮层的体积与 ALPS 指数有显著关联（均为 p <0.05）。ALPS-index 与 MMSE 评分呈正相关（部分 r = 0.435；p < 0.001），但 ALPS-index 与淀粉样蛋白 SUVR 之间无明显相关性（全部，p > 0.05）。结论通过DTI-ALPS测量到的AD患者血流减少可作为神经变性的标志物，与结构萎缩和认知能力下降相关。
{"title":"Impaired Glymphatic Flow on Diffusion Tensor MRI as a Marker of Neurodegeneration in Alzheimer’s Disease: Correlation with Gray Matter Volume Loss and Cognitive Decline Independent of Cerebral Amyloid Deposition","authors":"Minjae Kim, Yoo Sung Song, Kyunghwa Han, Yun Jung Bae, Ji Won Han, Ki Woong Kim","doi":"10.3233/jad-231131","DOIUrl":"https://doi.org/10.3233/jad-231131","url":null,"abstract":"Background: Impaired glymphatic flow on the Alzheimer’s disease (AD) spectrum may be evaluated using diffusion tensor image analysis along the perivascular space (DTI-ALPS). Objective: We aimed to validate impaired glymphatic flow and explore its association with gray matter volume, cognitive status, and cerebral amyloid deposition on the AD spectrum. Methods: 80 participants (mean age, 76.9±8.5 years; 57 women) with AD (n = 65) and cognitively normal (CN) (n = 15) who underwent 3T brain MRI including DTI and/or amyloid PET were included. After adjusting for age, sex, apolipoprotein E status, and burden of white matter hyperintensities, the ALPS-index was compared according to the AD spectrum. The association between the ALPS-index and gray matter volume, cognitive status, and quantitative amyloid from PET was assessed. Results: The ALPS-index in the AD was significantly lower (mean, 1.476; 95% CI, 1.395–1.556) than in the CN (1.784;1.615–1.952; p = 0.026). Volumes of the entorhinal cortex, hippocampus, temporal pole, and primary motor cortex showed significant associations with the ALPS-index (all, p < 0.05). There was a positive correlation between the ALPS-index and MMSE score (partial r = 0.435; p < 0.001), but there was no significant correlation between the ALPS-index and amyloid SUVRs (all, p > 0.05). Conclusions: Decreased glymphatic flow measured by DTI-ALPS in AD may serve as a marker of neurodegeneration correlating with structural atrophy and cognitive decline.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140684326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yaxuan Wu, Ming Tan, Yanling Gao, Na Geng, Weibin Zhong, Hairong Sun, Zhenguang Li, Chenxi Wu, Xuemei Li, Jinbiao Zhang
Background: The complement system plays crucial roles in cognitive impairment and acute ischemic stroke (AIS). High levels of complement proteins in plasma astrocyte-derived exosomes (ADEs) were proven to be associated with Alzheimer’s disease. We aimed to investigate the relationship of complement proteins in serum ADEs with poststroke cognitive impairment in type 2 diabetes mellitus (T2DM) patients. Methods: This study analyzed 197 T2DM patients who suffered AIS. The Beijing version of the Montreal Cognitive Assessment (MoCA) was used to assess cognitive function. Complement proteins in serum ADEs were quantified using ELISA kits. Results: Mediation analyses showed that C5b-9 and C3b in serum ADEs partially mediate the impact of obstructive sleep apnea (OSA), depression, small vessel disease (SVD), and infarct volume on cognitive function at the acute phase of AIS in T2DM patients. After adjusting for age, sex, time, and interaction between time and complement proteins in serum ADEs, the mixed linear regression showed that C3b and complement protein Factor B in serum ADEs were associated with MoCA scores at three-, six-, and twelve-months after AIS in T2DM patients. Conclusions: Our study suggested that the impact of OSA, depression, SVD, and infarct volume on cognitive impairment in the acute stage of AIS may partially mediate through the complement proteins in serum ADEs. Additionally, the complement proteins in serum ADEs at the acute phase of AIS associated with MoCA scores at three-, six-, twelve months after AIS in T2DM patients. REGISTRATION: URL: http://www.chictr.org.cn/,ChiCTR1900021544
{"title":"Complement Proteins in Serum Astrocyte-Derived Exosomes Are Associated with Poststroke Cognitive Impairment in Type 2 Diabetes Mellitus Patients","authors":"Yaxuan Wu, Ming Tan, Yanling Gao, Na Geng, Weibin Zhong, Hairong Sun, Zhenguang Li, Chenxi Wu, Xuemei Li, Jinbiao Zhang","doi":"10.3233/jad-231235","DOIUrl":"https://doi.org/10.3233/jad-231235","url":null,"abstract":"Background: The complement system plays crucial roles in cognitive impairment and acute ischemic stroke (AIS). High levels of complement proteins in plasma astrocyte-derived exosomes (ADEs) were proven to be associated with Alzheimer’s disease. We aimed to investigate the relationship of complement proteins in serum ADEs with poststroke cognitive impairment in type 2 diabetes mellitus (T2DM) patients. Methods: This study analyzed 197 T2DM patients who suffered AIS. The Beijing version of the Montreal Cognitive Assessment (MoCA) was used to assess cognitive function. Complement proteins in serum ADEs were quantified using ELISA kits. Results: Mediation analyses showed that C5b-9 and C3b in serum ADEs partially mediate the impact of obstructive sleep apnea (OSA), depression, small vessel disease (SVD), and infarct volume on cognitive function at the acute phase of AIS in T2DM patients. After adjusting for age, sex, time, and interaction between time and complement proteins in serum ADEs, the mixed linear regression showed that C3b and complement protein Factor B in serum ADEs were associated with MoCA scores at three-, six-, and twelve-months after AIS in T2DM patients. Conclusions: Our study suggested that the impact of OSA, depression, SVD, and infarct volume on cognitive impairment in the acute stage of AIS may partially mediate through the complement proteins in serum ADEs. Additionally, the complement proteins in serum ADEs at the acute phase of AIS associated with MoCA scores at three-, six-, twelve months after AIS in T2DM patients. REGISTRATION: URL: http://www.chictr.org.cn/,ChiCTR1900021544","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140683036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calum Marr, Bethany McDowell, C. Holmes, Christopher J Edwards, Christopher Cardwell, M. Mchenry, Gary Meenagh, J. Teeling, B. McGuinness
Background: Evidence suggests that TNF inhibitors (TNFi) used to treat rheumatoid arthritis (RA) may protect against Alzheimer’s disease progression by reducing inflammation. Objective: To investigate whether RA patients with mild cognitive impairment (MCI) being treated with a TNFi show slower cognitive decline than those being treated with a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD). Methods: 251 participants with RA and MCI taking either a csDMARD (N = 157) or a TNFi (N = 94) completed cognitive assessments at baseline and 6-month intervals for 18 months. It was hypothesized that those taking TNFis would show less decline on the primary outcome of Free and Cued Selective Reminding Test with Immediate Recall (FCSRT-IR) and the secondary outcome of Montreal Cognitive Assessment (MoCA). Results: No significant changes in FCSRT-IR scores were observed in either treatment group. There was no significant difference in FCSRT-IR between treatment groups at 18 months after adjusting for baseline (mean difference = 0.5, 95% CI = –1.3, 2.3). There was also no difference in MoCA score (mean difference = 0.4, 95% CI = –0.4, 1.3). Conclusions: There was no cognitive decline in participants with MCI being treated with TNFis and csDMARDs, raising the possibility both classes of drug may be protective. Future studies should consider whether controlling inflammatory diseases using any approach is more important than a specific therapeutic intervention.
{"title":"The RESIST Study: Examining Cognitive Change in Rheumatoid Arthritis Patients with Mild Cognitive Impairment Being Treated with a TNF-Inhibitor Compared to a Conventional Synthetic Disease-Modifying Anti-Rheumatic Drug","authors":"Calum Marr, Bethany McDowell, C. Holmes, Christopher J Edwards, Christopher Cardwell, M. Mchenry, Gary Meenagh, J. Teeling, B. McGuinness","doi":"10.3233/jad-231329","DOIUrl":"https://doi.org/10.3233/jad-231329","url":null,"abstract":"Background: Evidence suggests that TNF inhibitors (TNFi) used to treat rheumatoid arthritis (RA) may protect against Alzheimer’s disease progression by reducing inflammation. Objective: To investigate whether RA patients with mild cognitive impairment (MCI) being treated with a TNFi show slower cognitive decline than those being treated with a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD). Methods: 251 participants with RA and MCI taking either a csDMARD (N = 157) or a TNFi (N = 94) completed cognitive assessments at baseline and 6-month intervals for 18 months. It was hypothesized that those taking TNFis would show less decline on the primary outcome of Free and Cued Selective Reminding Test with Immediate Recall (FCSRT-IR) and the secondary outcome of Montreal Cognitive Assessment (MoCA). Results: No significant changes in FCSRT-IR scores were observed in either treatment group. There was no significant difference in FCSRT-IR between treatment groups at 18 months after adjusting for baseline (mean difference = 0.5, 95% CI = –1.3, 2.3). There was also no difference in MoCA score (mean difference = 0.4, 95% CI = –0.4, 1.3). Conclusions: There was no cognitive decline in participants with MCI being treated with TNFis and csDMARDs, raising the possibility both classes of drug may be protective. Future studies should consider whether controlling inflammatory diseases using any approach is more important than a specific therapeutic intervention.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140685249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tracy Butler, Xiuyuan H. Wang, Gloria C. Chiang, K. Xi, S. Niogi, Lidia Glodzik, Yi Li, Q. Razlighi, Liangdong Zhou, S. H. Hojjati, Ilker Ozsahin, Xiangling Mao, Thomas Maloney, E. Tanzi, N. Rahmouni, C. Tissot, Firoza Z. Lussier, Sudhin A. Shah, D. Shungu, Ajay Gupta, M. D. de Leon, P. D. Mozley, T. Pascoal, P. Rosa-Neto
Background: Alzheimer’s disease (AD) pathology is considered to begin in the brainstem, and cerebral microglia are known to play a critical role in AD pathogenesis, yet little is known about brainstem microglia in AD. Translocator protein (TSPO) PET, sensitive to activated microglia, shows high signal in dorsal brainstem in humans, but the precise location and clinical correlates of this signal are unknown. Objective: To define age and AD associations of brainstem TSPO PET signal in humans. Methods: We applied new probabilistic maps of brainstem nuclei to quantify PET-measured TSPO expression over the whole brain including brainstem in 71 subjects (43 controls scanned using 11C-PK11195; 20 controls and 8 AD subjects scanned using 11C-PBR28). We focused on inferior colliculi (IC) because of visually-obvious high signal in this region, and potential relevance to auditory dysfunction in AD. We also assessed bilateral cortex. Results: TSPO expression was normally high in IC and other brainstem regions. IC TSPO was decreased with aging (p = 0.001) and in AD subjects versus controls (p = 0.004) In cortex, TSPO expression was increased with aging (p = 0.030) and AD (p = 0.033). Conclusions: Decreased IC TSPO expression with aging and AD—an opposite pattern than in cortex—highlights underappreciated regional heterogeneity in microglia phenotype, and implicates IC in a biological explanation for strong links between hearing loss and AD. Unlike in cerebrum, where TSPO expression is considered pathological, activated microglia in IC and other brainstem nuclei may play a beneficial, homeostatic role. Additional study of brainstem microglia in aging and AD is needed.
背景：阿尔茨海默病（AD）的病理变化被认为始于脑干，已知脑小胶质细胞在AD发病机制中起着关键作用，但人们对AD中的脑干小胶质细胞知之甚少。对活化的小胶质细胞敏感的转座子蛋白（TSPO）PET在人类背侧脑干显示出高信号，但这一信号的确切位置和临床相关性尚不清楚。研究目的确定人类脑干 TSPO PET 信号与年龄和 AD 的关系。方法我们应用新的脑干核团概率图，对 71 名受试者（43 名对照组，使用 11C-PK11195 扫描；20 名对照组和 8 名 AD 受试者，使用 11C-PBR28 扫描）全脑（包括脑干）的 PET 测量 TSPO 表达进行量化。我们重点研究了下侧副神经体（IC），因为该区域在视觉上具有明显的高信号，而且可能与 AD 的听觉功能障碍有关。我们还评估了双侧皮层。结果TSPO在IC和其他脑干区域的表达通常很高。在大脑皮层中，TSPO 的表达随着年龄的增长而增加（p = 0.030），随着年龄的增长而增加（p = 0.033）。结论IC中TSPO的表达随衰老和AD而减少--与皮层中的模式相反--凸显了小胶质细胞表型中未被重视的区域异质性，并将IC与听力损失和AD之间密切联系的生物学解释联系了起来。在大脑中，TSPO 的表达被认为是病理性的，而在集成电路和其他脑干核中，活化的小胶质细胞可能发挥有益的平衡作用。还需要对脑干小胶质细胞在衰老和注意力缺失症中的作用进行更多研究。
{"title":"Reduction in Constitutively Activated Auditory Brainstem Microglia in Aging and Alzheimer’s Disease","authors":"Tracy Butler, Xiuyuan H. Wang, Gloria C. Chiang, K. Xi, S. Niogi, Lidia Glodzik, Yi Li, Q. Razlighi, Liangdong Zhou, S. H. Hojjati, Ilker Ozsahin, Xiangling Mao, Thomas Maloney, E. Tanzi, N. Rahmouni, C. Tissot, Firoza Z. Lussier, Sudhin A. Shah, D. Shungu, Ajay Gupta, M. D. de Leon, P. D. Mozley, T. Pascoal, P. Rosa-Neto","doi":"10.3233/jad-231312","DOIUrl":"https://doi.org/10.3233/jad-231312","url":null,"abstract":"Background: Alzheimer’s disease (AD) pathology is considered to begin in the brainstem, and cerebral microglia are known to play a critical role in AD pathogenesis, yet little is known about brainstem microglia in AD. Translocator protein (TSPO) PET, sensitive to activated microglia, shows high signal in dorsal brainstem in humans, but the precise location and clinical correlates of this signal are unknown. Objective: To define age and AD associations of brainstem TSPO PET signal in humans. Methods: We applied new probabilistic maps of brainstem nuclei to quantify PET-measured TSPO expression over the whole brain including brainstem in 71 subjects (43 controls scanned using 11C-PK11195; 20 controls and 8 AD subjects scanned using 11C-PBR28). We focused on inferior colliculi (IC) because of visually-obvious high signal in this region, and potential relevance to auditory dysfunction in AD. We also assessed bilateral cortex. Results: TSPO expression was normally high in IC and other brainstem regions. IC TSPO was decreased with aging (p = 0.001) and in AD subjects versus controls (p = 0.004) In cortex, TSPO expression was increased with aging (p = 0.030) and AD (p = 0.033). Conclusions: Decreased IC TSPO expression with aging and AD—an opposite pattern than in cortex—highlights underappreciated regional heterogeneity in microglia phenotype, and implicates IC in a biological explanation for strong links between hearing loss and AD. Unlike in cerebrum, where TSPO expression is considered pathological, activated microglia in IC and other brainstem nuclei may play a beneficial, homeostatic role. Additional study of brainstem microglia in aging and AD is needed.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140684512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicola Luigi Bragazzi, Ayoub Boulares, Sergio Garbarino
In their article, Finch and Burstein explore the hypothesis that Alzheimer’s disease and related dementias (ADRD) may predominantly be phenomena of the modern era. Through a review of classical Greek and Latin literature, they found minimal reference to conditions akin to ADRD, suggesting a historical rarity of severe cognitive decline. Instead, ancient texts focused on physical aspects of aging, with cognitive changes, when noted, not resembling modern-day dementia. Finch and Burstein further extend their analysis by drawing parallels with the Tsimane people of Bolivia, known for their low prevalence of dementia and cardiovascular diseases, attributed to lifestyle factors such as diet and physical activity. By comparing historical sleep patterns transitioning from segmented to monophasic sleep with those of the Tsimane community, we enriched Finch and Burstein’s research, highlighting the need to take into account a range of diverse factors, including sleep, in understanding the etiopathogenesis of ADRD in today’s society.
{"title":"Could the Historical Transition from Segmented to Monophasic Sleep Explain the Modern Insurgence of Alzheimer’s Disease and Related Dementias?","authors":"Nicola Luigi Bragazzi, Ayoub Boulares, Sergio Garbarino","doi":"10.3233/jad-240154","DOIUrl":"https://doi.org/10.3233/jad-240154","url":null,"abstract":"In their article, Finch and Burstein explore the hypothesis that Alzheimer’s disease and related dementias (ADRD) may predominantly be phenomena of the modern era. Through a review of classical Greek and Latin literature, they found minimal reference to conditions akin to ADRD, suggesting a historical rarity of severe cognitive decline. Instead, ancient texts focused on physical aspects of aging, with cognitive changes, when noted, not resembling modern-day dementia. Finch and Burstein further extend their analysis by drawing parallels with the Tsimane people of Bolivia, known for their low prevalence of dementia and cardiovascular diseases, attributed to lifestyle factors such as diet and physical activity. By comparing historical sleep patterns transitioning from segmented to monophasic sleep with those of the Tsimane community, we enriched Finch and Burstein’s research, highlighting the need to take into account a range of diverse factors, including sleep, in understanding the etiopathogenesis of ADRD in today’s society.","PeriodicalId":14929,"journal":{"name":"Journal of Alzheimer's Disease","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140579528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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