Citations

AbstractBackgroundPhase four of the Alzheimer’s Disease Neuroimaging Initiative (ADNI4) began in 2023. This time‐period corresponded to MRI vendors introducing product sequences with compressed sensing (CS), cross‐vendor adoption of arterial spin‐labelling (ASL) and multi‐band slice excitation, and hardware improvements (head‐coils, increased gradient amplitudes). These advances enabled the acquisition of new imaging measures and reduced scan times. The ADNI4 MRI protocol aims to maintain longitudinal consistency across two decades of data acquisition, while adopting new technologies. Here we describe the design and justification behind the ADNI4 protocol and list the target imaging biomarkers.MethodsThe ADNI4 MRI protocol includes 9 MRI sequences; i) T1‐weighted (T1w) MP‐RAGE, ii) a compressed sensing T1w MP‐RAGE, iii) 3D T2w FLAIR, iv) structural isotropic 3D T2w v) T2*‐weighted susceptibility imaging vi) multi‐post labelling delay (PLD) 3D ASL, vii) 2D multi‐band‐multiple‐shell diffusion (dMRI), viii) 2D multi‐band EPI BOLD ix) high resolution, limited field of view, imaging centered on the hippocampus. Table 1 gives a detailed summary of the key protocol parameters and lists some of the imaging biomarkers that can be obtained from each series.ResultsStructural imaging was kept consistent across imaging sites. Variations in vendor specific sequences, software upgrades, and hardware performance capabilities, resulted in variations in advanced imaging strategies. Table 2 highlights the advanced sequences introduced in ADNI4, which will gradually be implemented as the required upgrades and licenses are obtained at each site. The main advanced sequences that are new in ADNI4 from ADNI 3 are i) CS for T1w images, ii) pseudo‐continuous‐ASL (pCASL) being implemented on all 3 vendors (GE, Siemens, Philips), iii) multi‐PLD ASL, which allows for the generation of quantitative maps of cerebral blood‐flow (CBF) and arterial transit times (ATTs), iv) and isotropic 1mm3 resolution for 3D FLAIR. When ADNI4 began, product sequences that utilized artificial intelligence were not widely available and could not be adequately tested before the rollout of ADNI4.ConclusionsThe ADNI4 database will continue to help the neuroimaging community, not only extract valuable imaging biomarkers, but provide the data necessary to test the impact of advanced imaging strategies on diagnostic accuracy and disease sensitivity.

ABSTRACT Hypoxic stress responses are essential for cellular and organismal survival and drive gene regulation across diverse biological pathways, including cell cycle progression and energy metabolism. Here, we show that topoisomerase IIβ (TOP2B) regulates DNA topology and transcription of hypoxia-inducible genes (HIGs) in a DNA-dependent protein kinase (DNA-PK)-dependent manner. Integrated cellular, biochemical, and genomic analyses reveal an antagonistic yet correlated relationship between TOP2B and DNA-PK activities. Under normoxic conditions, TOP2B associates with HIGs and represses transcription by suppressing DNA negative supercoiling formation and accessibility. Under hypoxic exposure, TOP2B dissociates from HIGs, while DNA-PK and HIF1α are recruited to activate HIGs. Notably, DNA-PK is required for the repressive function of TOP2B, as DNA-PK knockout abrogates TOP2B release and activity, resulting in elevated expression of a number of HIGs. Mechanistically, DNA-PK phosphorylates TOP2B at T1403, stimulating its catalytic activity to restrain DNA unwinding and accessibility, thereby suppressing HIG transcription. Collectively, these findings identify a novel role for TOP2B and DNA-PK-mediated regulation of TOP2B as key transcriptional regulators of HIG expression. We propose that phosphorylation-dependent modulation of TOP2B activity is coordinated with transcriptional states and determines DNA topology to regulate Pol II transcription.

Abstract US clinical practice guidelines for the diagnostic evaluation of cognitive impairment due to Alzheimer's disease (AD) or AD and related dementias (ADRD) are decades old and aimed at specialists. This evidence‐based guideline was developed to empower all—including primary care—clinicians to implement a structured approach for evaluating a patient with symptoms that may represent clinical AD/ADRD. Through a modified‐Delphi approach and guideline‐development process (7374 publications were reviewed; 133 met inclusion criteria) an expert workgroup developed recommendations as steps in a patient‐centered evaluation process. This summary focuses on recommendations, appropriate for any practice setting, forming core elements of a high‐quality, evidence‐supported evaluation process aimed at characterizing, diagnosing, and disclosing the patient's cognitive functional status, cognitive–behavioral syndrome, and likely underlying brain disease so that optimal care plans to maximize patient/care partner dyad quality of life can be developed; a companion article summarizes specialist recommendations. If clinicians use this guideline and health‐care systems provide adequate resources, outcomes should improve in most patients in most practice settings. Highlights US clinical practice guidelines for the diagnostic evaluation of cognitive impairment due to Alzheimer's disease (AD) or AD and related dementias (ADRD) are decades old and aimed at specialists. This evidence‐based guideline was developed to empower all—including primary care—clinicians to implement a structured approach for evaluating a patient with symptoms that may represent clinical AD/ADRD. This summary focuses on recommendations, appropriate for any practice setting, forming core elements of a high‐quality, evidence‐supported evaluation process aimed at characterizing, diagnosing, and disclosing the patient's cognitive functional status, cognitive–behavioral syndrome, and likely underlying brain disease so that optimal care plans to maximize patient/care partner dyad quality of life can be developed; a companion article summarizes specialist recommendations. If clinicians use this guideline and health‐care systems provide adequate resources, outcomes should improve in most patients in most practice settings.

Abstract US clinical practice guidelines for the diagnostic evaluation of cognitive impairment due to Alzheimer's disease (AD) or a related dementia (ADRD) are two decades old. This evidence‐based guideline was developed to empower all clinicians to implement a structured approach for evaluating a patient with symptoms that may represent clinical AD/ADRD. An expert workgroup conducted a review of 7374 publications (133 met inclusion criteria) and developed recommendations as steps in an evaluation process. This summary briefly reviews core recommendations and details specialist recommendations of a high‐quality, evidence‐supported evaluation process aimed at characterizing, diagnosing, and disclosing the patient's cognitive functional status, cognitive–behavioral syndrome, and likely underlying brain disease so that optimal care plans to maximize patient/care partner dyad quality of life can be developed; a companion article summarizes primary care recommendations. If clinicians use the recommendations in this guideline and health‐care systems provide adequate resources, outcomes should improve in most patients in most practice settings. Highlights US clinical practice guidelines for the diagnostic evaluation of cognitive impairment due to Alzheimer's disease (AD) or related dementias (ADRD) are decades old and aimed at specialists. This evidence‐based guideline was developed to empower all—including primary care—clinicians to implement a structured approach for evaluating a patient with symptoms that may represent clinical AD/ADRD. This summary focuses on recommendations appropriate for specialty practice settings, forming key elements of a high‐quality, evidence‐supported evaluation process aimed at characterizing, diagnosing, and disclosing the patient's cognitive functional status, cognitive–behavioral syndrome, and likely underlying brain disease so that optimal care plans to maximize patient/care partner dyad quality of life can be developed; a companion article summarizes primary care recommendations. If clinicians use this guideline and health‐care systems provide adequate resources, outcomes should improve in most patients in most practice settings.

Abstract US clinical practice guidelines for the diagnostic evaluation of cognitive impairment due to Alzheimer's Disease (AD) or AD and related dementias (ADRD) are decades old and aimed at specialists. This evidence‐based guideline was developed to empower all—including primary care—clinicians to implement a structured approach for evaluating a patient with symptoms that may represent clinical AD/ADRD. As part of the modified Delphi approach and guideline development process (7374 publications were reviewed; 133 met inclusion criteria) an expert workgroup developed recommendations as steps in a patient‐centered evaluation process. The workgroup provided a summary of validated instruments to measure symptoms in daily life (including cognition, mood and behavior, and daily function) and to test for signs of cognitive impairment in the office. This article distills this information to provide a resource to support clinicians in the implementation of this approach in clinical practice. The companion articles provide context for primary care and specialty clinicians with regard to how to fit these instruments into the workflow and actions to take when integration of performance on these instruments with clinical profile and clinician judgment support potential cognitive impairment.

Abstract INTRODUCTION The U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (U.S. POINTER) is evaluating lifestyle interventions in older adults at risk for cognitive decline and dementia. Here we characterize the baseline data set of the POINTER Imaging ancillary study. METHODS Participants underwent health and cognitive assessments and neuroimaging with multimodal positron emission tomography (PET) (beta‐amyloid [Aβ] and tau) and magnetic resonance imaging (MRI). Framingham risk score (FRS) was used to quantify cardiovascular disease (CVD) risk. RESULTS A total of 1052 participants (31% from underrepresented ethnoracial groups) were enrolled. Compared to Aβ−, Aβ+ (29%) participants were older, had higher apolipoprotein E ( APOE ) ε4 carriage rate and white matter hyperintensity volume, and greater temporal tau. FRS was related to MRI measures, but not AD biomarkers. FRS and tau had independent effects on cognition. DISCUSSION In this heterogenous, at‐risk cohort, CVD risk was related to more abnormal brain structure and poorer cognition, representing a putative non‐AD (Alzheimer's disease) pathway to brain injury and cognitive decline. Highlights The U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (U.S. POINTER) cohort is enriched for cardiovascular disease (CVD) and poor lifestyle POINTER Imaging collected multimodal neuroimaging data in this unique, at‐risk cohort Amyloid burden was related to age, apolipoprotein E ( APOE ) ε4 carriage, and measures of disease progression Associations between amyloid and tau, and tau and cognition, were relatively weak CVD risk and tau pathology were independently related to memory

Background/Objectives: Respiratory syncytial virus (RSV) causes symptoms similar to a mild cold for adults, but in case of infants, it causes bronchitis and/or pneumonia, and in some cases, mortality. Mucosal immunity within the respiratory tract includes tissue-resident memory T (TRM) cells and tissue-resident memory B (BRM) cells, which provides rapid and efficient protection against RSV re-infection. Therefore, vaccine strategies should aim to generate mucosal immune responses. However, the interactions between RSV vaccines and mucosal immune responses within the respiratory tract are poorly understood. We evaluated a mucosal immune system following immunization by RSV vaccine with poly-sorbitol transporter (RSV-PST), a nanoparticle adjuvant. Methods: We intranasally immunized the RSV-PST and identified the systemic and mucosal immune responses. Furthermore, we challenged with RSV A2 strain after immunization and investigated the protective effects. Results: Consequently, antigen-specific CD8+ TRM cells were markedly elevated in the lung parenchyma, yet exhibited impaired cytokine expression. In contrast, humoral immunity, with systemic antibody production from serum, but not in the respiratory tract, was significantly increased by RSV-PST immunization. Interestingly, the production of respiratory mucosal antigen-specific IgG after RSV A2 challenge dramatically increased in the bronchoalveolar lavage fluid (BALF) of the RSV-PST immunized group in the presence of FTY720, and the lung-infected RSV titer was significantly lower in this group. Furthermore, after RSV A2 challenge, CD69+ IgG+ BRM cells were significantly increased in lung tissues in the RSV-PST group. Conclusions: The RSV-PST vaccine has protective effects against RSV infection by promoting both systemic and local humoral immunity rather than cellular immunity.

Importance Typical cysteine-altering NOTCH3 ( NOTCH3 cys ) variants are highly prevalent (approximately 1 in 300 individuals) and are associated with a broad spectrum of small vessel disease (SVD), ranging from early-onset stroke and dementia (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [CADASIL]) to nonpenetrance. A staging system that captures the full NOTCH3 -SVD severity spectrum is needed and currently lacking. Objective To design a simple disease severity staging system that captures the broad clinicoradiological NOTCH3 -SVD severity spectrum. Design, Setting, and Participants A cohort study was performed in which the NOTCH3 -SVD severity staging system was developed using a discovery cohort (2019-2020) and validated in independent international CADASIL cohorts (1999-2023) and the UK Biobank. Clinical and imaging data were collected from participants originating from 23 international CADASIL cohorts and from the UK Biobank. Eligibility criteria were presence of a NOTCH3 cys variant, availability of brain magnetic resonance imaging, and modified Rankin Scale score. The discovery cohort consisted of 195 NOTCH3 cys -positive cases from families with CADASIL; the validation set included 1713 NOTCH3 cys -positive cases from 15 countries. The UK Biobank cohort consisted of 101 NOTCH3 cys -positive individuals. Data from 2-year (2019-2023) and 18-year (1999-2017) follow-up studies were also analyzed. Data analysis was performed from July 2023 to August 2024. Main Outcomes and Measures Percentage of cases following the sequence of events of the NOTCH3 -SVD stages, and the association between the stages and ischemic stroke, intracerebral hemorrhage, global cognition, processing speed, brain volume, brain microstructural damage, and serum neurofilament light chain (NfL) level. Results The NOTCH3 -SVD staging system encompasses 9 disease stages or substages, ranging from stage 0 (premanifest stage) to stage 4B (end stage). Of all 1908 cases, which included 195 in the discovery cohort (mean [SD] age, 52.4 [12.2] years) and 1713 in the validation cohorts (mean [SD] age, 53.1 [13.0] years), 1789 (94%) followed the sequence of events defined by the NOTCH3 -SVD staging system. The NOTCH3 -SVD stages were associated with neuroimaging outcomes in the NOTCH3 cys -positive cases in the CADASIL cohorts and in the UK Biobank and with cognitive outcomes and serum NfL level in cases from the CADASIL cohorts. The NOTCH3 -SVD staging system captured disease progression and was associated with 18-year survival. Conclusions and Relevance The NOTCH3 -SVD staging system captures the full disease spectrum, from asymptomatic individuals with a NOTCH3 cys variant to patients with end-stage disease. The NOTCH3 -SVD staging system is a simple but effective tool for uniform disease staging in the clinic and in research.

Abstract Glioblastoma is the most common malignant primary brain tumor and is universally fatal. Treatment involves maximal safe resection with adjuvant chemoradiation. Poor prognosis in glioblastoma is multifactorial, and local and systemic immunosuppression is an important factor. Extracellular vesicles (EVs) are small, membrane-bound particles released by cells into the external environment. They play a key role in intercellular communication. In glioblastomas, EVs regulate immunosuppression through induction of myeloid-derived suppressor cells (MDSCs) in a process dependent on the PD-1/PD-L1 and IL-6 axes. Primary cilia are microtubule-based organelles that play crucial roles in various cellular processes and signal transduction cascades. We recently showed that primary cilia modulate IL-6 expression and consequently, MDSC induction. Comparative proteomic analysis of EVs derived from human glioblastoma cells devoid of cilia showed loss of ICAM-1 expression compared to control glioblastoma cells. ICAM-1 (Intercellular Adhesion Molecule-1) is a cell surface glycoprotein that mediates cell-cell adhesion and immune responses. In this study, we showed that depletion of primary cilia in human glioblastoma cells result in increased PD-L1 but loss of IL-6 and ICAM-1. RNAi-meidated loss of ICAM-1 was synergistic with primary cilia depletion in preventing MDSC inductionn normal human monocytes exposed to glioblastoma-derived EVs. Exogenous IFN-g was sufficient to restore IL-6 levels and MDSC induction despite loss of primary cilia and ICAM-1 suggesting that primary cilia act upstream of IFN-g, IL-6 and ICAM-1 in glioblastoma-mediated MDSC induction. This study is the first to connect primary cilia signal transduction to IL-6 and ICAM-1 expression and to MDSC induction. The evidence suggests a potential parallel primary cilia regulatory cascade independent of the PD-L1 axis that controls tumor-mediated immunosuppression. These results may inform novel therapeutic strategies aimed at increasing efficacy of immunotherapy in the glioblastoma and other neoplastic processes.