Distinct translatome changes in specific neural populations precede electroencephalographic changes in prion-infected mice.

Selective vulnerability is an enigmatic feature of neurodegenerative diseases (NDs), whereby a widely expressed protein causes lesions in specific cell types and brain regions. Using the RiboTag method in mice, translational responses of five neural subtypes to acquired prion disease (PrD) were measured. Pre-onset and disease onset timepoints were chosen based on longitudinal electroencephalography (EEG) that revealed a gradual increase in theta power between 10- and 18-weeks after prion injection, resembling a clinical feature of human PrD. At disease onset, marked by significantly increased theta power and histopathological lesions, mice had pronounced translatome changes in all five cell types despite appearing normal. Remarkably, at a pre-onset stage, prior to EEG and neuropathological changes, we found that 1) translatomes of astrocytes indicated reduced synthesis of ribosomal and mitochondrial components, 2) glutamatergic neurons showed increased expression of cytoskeletal genes, and 3) GABAergic neurons revealed reduced expression of circadian rhythm genes. These data demonstrate that early translatome responses to neurodegeneration emerge prior to conventional markers of disease and are cell type-specific. Therapeutic strategies may need to target multiple pathways in specific populations of cells, early in disease.

Postoperative Outcomes of Tangential versus Segmental Resection and End-to-end Reconstruction of the Superior Mesenterico-Portal Vein During Pancreatoduodenectomy for Pancreatic Adenocarcinoma: A Single-Center Experience.

BACKGROUND/AIM: The impact of venous resections and reconstruction techniques on morbidity after surgery for pancreatic cancer (PDAC) remains controversial. PATIENTS AND METHODS: A total of 143 patients receiving pancreatoduodenectomy (PD) for PDAC between 2013 and 2018 were identified from a prospective database. Morbidity and mortality after PD with tangential resection versus end-to-end reconstruction were assessed. RESULTS: Fifty-two of 143 (36.4%) patients underwent PD with portal venous resection (PVR), which was associated with longer operation times [398 (standard error (SE) 12.01) vs. 306 (SE 13.09) min, p<0.001]. PVR was associated with longer intensive-care-unit stay (6.3 vs. 3.8 days, p=0.054); morbidity (Clavien-Dindo classification (CDC) grade IIIa-V 45.8% vs. 35.8%, p=0.279) and 30-day mortality (4.1% vs. 4.2%, p>0.99) were not different. Tangential venous resection was associated with similar CDC grade IIIa-IV (42.9% vs. 50.0%, p=0.781) and 30-day mortality rates (3.5% vs. 4.1%, p=0.538) as segmental resection and end-to-end venous reconstruction. CONCLUSION: Both tangential and segmental PVR appear feasible and can be safely performed to achieve negative resection margins.

Radiological prediction of portal vein infiltration in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy characterized by early loco-regional invasion. Portal vein resection (PVR) during pancreatoduodenectomy (PD) for PDAC is performed if tumor cell invasion to the venous wall (PVI) is suspected. The aim of this study is to evaluate radiological criteria for predicting PVR and PVI. METHODS: Patients undergoing PD for PDAC were identified from a prospectively maintained database. On the basis of CT- and MRI-based imaging portal vein tumor contact (PV), stranding of the superior mesenteric artery (SMA) and any alterations of the superior mesenterico-portal vein (SMPV) were evaluated. The accuracy of PVI and PVR prediction based on the radiological parameters was calculated. RESULTS: 143 patients were included in the study. 48 patients underwent PVR (34%), PVI was diagnosed in 23 patients (16%). Median overall survival was 22 months. Prediction of PVR (sensitivity 79%, negative predictive value 88%, p = 0.010) and PVI (sensitivity 95%, negative predictive value 99%, p = 0.002) was most accurate for any SMPV alterations as compared to the other radiological parameters. SMPV alterations qualified as an independent prognostic parameter (26.5 months vs. 33.5months, p = 0.034). CONCLUSION: Radiological evaluation of any SMPV alterations is a simple preoperative method to accurately predict PVI. Assessing SMPV alterations may help to identify candidates for neoadjuvant therapy.

P2Y1 receptor blockade normalizes network dysfunction and cognition in an Alzheimer's disease model.

Astrocytic hyperactivity is an important contributor to neuronal-glial network dysfunction in Alzheimer's disease (AD). We have previously shown that astrocyte hyperactivity is mediated by signaling through the P2Y1 purinoreceptor (P2Y1R) pathway. Using the APPPS1 mouse model of AD, we here find that chronic intracerebroventricular infusion of P2Y1R inhibitors normalizes astroglial and neuronal network dysfunction, as measured by in vivo two-photon microscopy, augments structural synaptic integrity, and preserves hippocampal long-term potentiation. These effects occur independently from ß-amyloid metabolism or plaque burden but are associated with a higher morphological complexity of periplaque reactive astrocytes, as well as reduced dystrophic neurite burden and greater plaque compaction. Importantly, APPPS1 mice chronically treated with P2Y1R antagonists, as well as APPPS1 mice carrying an astrocyte-specific genetic deletion (Ip3r2-/-) of signaling pathways downstream of P2Y1R activation, are protected from the decline of spatial learning and memory. In summary, our study establishes the restoration of network homoeostasis by P2Y1R inhibition as a novel treatment target in AD.