Citations

Abstract Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Although the live-attenuated measles virus (MeV) is one of the safest and most efficacious human vaccines, a measles-vectored COVID-19 vaccine candidate expressing the SARS-CoV-2 spike failed to elicit neutralizing antibody (nAb) responses in a phase-1 clinical trial, especially in measles-immune individuals. Here, we constructed a comprehensive panel of MeV-based COVID-19 vaccine candidates using a MeV with extensive modifications on the envelope glycoproteins (MeV-MR). We show that artificial trimerization of the spike is critical for the induction of nAbs and that their magnitude can be significantly augmented when the spike protein is synchronously fused to a dodecahedral scaffold. Furthermore, preexisting measles immunity did not abolish heterologous immunity elicited by our vector. Our results highlight the importance of antigen optimization in the development of spike-based COVID-19 vaccines and therapies.

Colorectal carcinoma with sarcomatoid components (which includes so-called carcinosarcomas and sarcomatoid carcinomas) is a rare subtype with 50 reported cases in the literature and overlapping criteria with undifferentiated carcinoma. We collected and described 15 cases from 10 men and 5 women, with a mean age of 66 years. Symptoms included abdominal pain and gastrointestinal bleeding. Most tumors presented in the rectosigmoid region, with a mean size of 8.2 cm. The sarcomatoid component, on average, represented 58% of the tumors and took many forms, including spindled (10 cases), anaplastic (9 cases), and rhabdoid (3 cases); one case showed osteoid matrix. Tumor budding was usually high, and tumor-infiltrating lymphocytes were usually low. The sarcomatoid component was keratin-positive in 10 cases. One case showed loss of mismatch repair protein expression, and 2 cases showed SMARCA4 loss (1 also with SMARCA2 loss). Molecular testing identified mutations in KRAS (n=1), NRAS (n=2), BRAF (n=2), APC (n=1), and TP53 (n=1) in a few cases. Tumors often presented at advanced stage, with 11 cases pT4, 9 cases with nodal metastases, and 7 cases with distant metastases. Follow-up was available for 10 cases (median: 2 months), with 2 alive without disease, 3 alive with disease, and 5 dead. Our findings roughly corresponded with those in previously reported cases. Colorectal carcinoma with sarcomatoid components is rare and aggressive, with a poor prognosis for many patients. We suggest that spindled cells, anaplasia, heterologous elements, and/or a component with definable sarcomatous lineage be used to distinguish colorectal carcinoma with sarcomatoid components from undifferentiated carcinoma.

Abstract Microglia, the major resident immune cells in the central nervous system, serve as the frontline soldiers against cerebral ischemic injuries, possibly along with metabolic alterations. However, signaling pathways involved in the regulation of microglial immunometabolism in ischemic stroke remain to be further elucidated. In this study, using single‐nuclei RNA sequencing, a microglial subcluster up‐regulated in ischemic brain tissues is identified, with high expression of Igf1 and Trem2, neuroprotective transcriptional signature and enhanced oxidative phosphorylation. Microglial depletion by PLX3397 exacerbates ischemic brain damage, which is reversed by repopulating the microglia with high Igf1 and Trem2 phenotype. Mechanistically, Igf1 serves as one of the major down‐stream molecules of Trem2, and Trem2‐Igf1 signaling axis regulates microglial functional and metabolic profiles, exerting neuroprotective effects on ischemic stroke. Overexpression of Igf1 and supplementation of cyclocreatine restore microglial glucometabolic levels and cellular functions even in the absence of Trem2. These findings suggest that Trem2‐Igf1 signaling axis reprograms microglial immunometabolic profiles and shifts microglia toward a neuroprotective phenotype, which has promising therapeutic potential in treating ischemic stroke.

AbstractBackgroundNeuropsychiatric symptoms (NPS) are frequent in Alzheimer’s Disease dementia (ADD) but a higher NPS burden is found in dementia with Lewy bodies (DLB). Lewy body (LB) pathology frequently co‐occurs with AD pathology and may not meet neuropathological criteria for DLB (ADLB). Previous studies have shown that both ADLB and DLB cases have faster cognitive and/or functional decline compared to AD. However, the differences in NPS severity over disease course and survival in these pathologic subgroups is not well understood.MethodCases from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) with a final neuropathologic diagnosis of DLB (±AD co‐pathology; n = 65), ADLB (n = 89), AD (without LB) (n = 140), and controls (no neuropathological diagnosis) (n = 82) were included. Total NPI‐Q (scores ranging from 0‐36) at time of enrollment and within 2.5 years of death were calculated for all groups. Statistical analysis utilizing ANCOVA (adjusting for age, sex, baseline MMSE and cognitive symptom duration) with pairwise comparisons, and Kaplan‐Meier curves were completed.ResultAge at onset of cognitive symptoms was not different between pathology groups. NPI‐Q scores at enrollment were highest in ADLB (7.33 ± 4.85), and higher (p<0.001) than DLB (5.10 ± 3.37), AD (4.54 ± 3.63) and controls (1.78 ± 1.70). At final evaluation, NPI‐Q scores were highest in DLB (10.04 ± 6.28), followed by ADLB (8.0 ± 4.), and ADD (7.61 ± 5.05) when compared to controls (2.78 ± 3.97) (all p<0.001). DLB and AD demonstrated significant increases in NPI‐Q severity during follow up (p < 0.001). AD had longer survival time (5.8 years) compared to ADLB (4.0 years) and DLB (3.9 years). Subjects with NPS had a shorter median survival time (3.4 years) compared to subjects without NPS (6.5 years; p = 0.002).ConclusionA higher NPS burden and shorter survival is seen in both DLB and ADLB, as compared with AD. This suggests that diffuse neocortical LB pathology is not the major driver of either NPS or survival.

AbstractBackgroundPathological Lewy body disease (LBD) may commonly present clinically as Parkinson’s disease dementia (PDD), Dementia with Lewy bodies (DLB) or Alzheimer’s disease dementia (ADD). Neuropathological definitions also include a group in which ADD is present, but the postmortem Lewy pathology does not meet threshold density and distribution levels for the neuropathological diagnosis of DLB (ADLB). Little is known about the cognitive profiles of patients with ADLB and despite common underlying pathology, studies delineating neuropsychological profiles in LBD are fraught with inconsistencies. We characterized the longitudinal cognitive trajectories defined by neuropsychological profiles in cases along the pathological spectrum of LBD.MethodCases from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) with a cognitive diagnosis of dementia at death and who at minimum, had two neuropsychological evaluations were included. Final neuropathological diagnosis was determined as LBD (neocortical or limbic LB ± AD), ADLB, and AD pathology only. LBD cases were categorized by their cognitive clinical syndromes as PDD and DLB. Global cognition was evaluated using MMSE. Neuropsychological domains of Memory, Executive function, language, attention, and visuospatial were evaluated. Mixed linear methods were used to predict longitudinal change for a given baseline MMSE.Result287 participants and 1874 participant‐years of data were included in this study. LBD (n = 115), and ADLB (52) groups were predominantly male, while AD (n = 114) group was primarily female. Baseline MMSE was similar across all pathologic groups. Linear mixed modelling methods showed faster decrease in memory domain scores (decreasing 0.22 units/year – 0.42 units/year faster, p = 0.01) in ADLB group compared to other groups. Significantly faster decline was noted in LBD and ADLB group in clock drawing (p<0.001), fluency scores (declining 1.02 unit/year faster p<0.001) compared to AD group. There was no difference between PDD and DLB clinical subgroups.ConclusionIn autopsy confirmed cases, ADLB had an accelerated trajectory of decline in memory tasks, while AD, and LBD appeared to have similar trajectories. In contrast, all groups with Lewy bodies progressed faster and showed accelerated decline compared to AD in measures of frontal‐subcortical functions. These results may inform antemortem classification of patients and diagnostic accuracy in these groups.

AbstractBackgroundCharacterizing disease trajectories in frontotemporal lobar degeneration (FTLD) is essential to determine the optimal timing for initiating therapeutic interventions, and there is an urgent need for novel and sensitive disease biomarkers. Intrinsic connectivity network (ICN) mapping using task‐free fMRI is a promising biomarker which reveals early abnormalities even before symptomatic onset (Dopper et al. 2014; Lee et al. 2016). Yet, ICN trajectories from the presymptomatic to symptomatic stages in FTLD mutation carriers remain unclear.MethodIn this cross‐sectional study, we used UCSF and ALLFTD Consortia data to study 129 carriers with variants in MAPT (presymptomatic/prodromal/symptomatic: 34/4/7), C9orf72 (30/9/12) and GRN (22/4/7). Using cross‐sectional data to construct ICN trajectories by genotype, we built separate generalized additive models for each genetic group to estimate non‐linear relationships between standardized connectivity changes and disease age across clinical stages. ICN connectivity was based on seed‐based analyses for networks associated with common clinical syndromes for each genetic group (i.e., salience and default mode [MAPT/C9orf72/GRN], corticobasal syndrome [MAPT/GRN], progressive supranuclear palsy syndrome [MAPT], sensorimotor and medial pulvinar‐related [C9orf72], and non‐fluent variant primary progressive aphasia (nfvPPA) syndrome networks [GRN]). We included 127 healthy controls as a reference to calculate ICN z‐scores for each carrier. Each carrier’s disease age was defined as the difference between the carrier’s chronological age and estimated age of onset based on multimodal measures of structural imaging, fluid biomarker and clinical assessments (Staffaroni et al. 2022).ResultIn MAPT+, presymptomatic carriers showed declining salience network connectivity starting approximately 30 years before estimated onset, which plateaued about 20 years before onset. In C9orf72+, salience network hyperconnectivity emerged about 30 years before onset and declined throughout the presymptomatic and symptomatic stages. For GRN+, connectivity changes as a function of disease age were found within the salience and nfvPPA networks, with connectivity stable until around 10 years before estimated onset, followed by decline starting in the late presymptomatic phase and continuing through the prodromal and symptomatic stages.ConclusionThese findings demonstrate that FTLD genes show distinct ICN trajectories throughout the clinical spectrum. These results help pave the way for determining the optimal timing to initiate therapeutic interventions.