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Synthetic excitatory synaptic organizer The human brain contains trillions of synapses within a vast network of neurons. Synapse remodeling is essential to ensure the efficient reception and integration of external stimuli and to store and retrieve information. Building and remodeling of synapses occurs throughout life under the control of synaptic organizer proteins. Errors in this process can lead to neuropsychiatric or neurological disorders. Suzuki et al. combined structural elements of natural synaptic organizers to develop an artificial version called CPTX, which has different binding properties (see the Perspective by Salinas). CPTX could act as a molecular bridge to reconnect neurons and restore excitatory synaptic function in animal models of cerebellar ataxia, familial Alzheimer's disease, and spinal cord injury. The findings illustrate how structure-guided approaches can help to repair neuronal circuits. Science , this issue p. eabb4853 ; see also p. 1052

The gradual accumulation of hepatic fibrosis in chronic liver disease results in clinical complications. The rate of hepatic fibrosis score progression (RFSP) in predicting clinical outcomes was assessed by extending the 4-year Hepatitis C Antiviral Long-term Treatment Against Cirrhosis (HALT-C) Trial to include preenrollment liver biopsies. The RFSP was calculated from the linear regression slope of Ishak fibrosis score vs time in 457 patients with liver biopsies (≥10-mm length) prior to the HALT-C Trial (575 biopsies) plus 1101 on-study biopsies (total 1676 biopsies). Individual slopes were calculated if duration from first to last biopsy was > 4 years. The RFSP as average fibrosis score vs average time in intervals (0-3 and >3 years prestudy, screening, month 24 and 48 on-study) in 455 patients in cohorts of baseline Ishak score ranged from 0.005 with Ishak score 2 to 0.124 with Ishak 6. The RFSP in individual patients (-0.35 to +0.97 Ishak units/year) had a mean of 0.12 ± 0.23 in 344 patients with prestudy and on-study biopsies (group A) and only 0.17 ± 0.22 in 169 with prestudy and screening biopsies (group B). Group A patients with RFSP slope ≥ 0.2 (95 patients, 27.6%) had higher 7-year cumulative rates of non-hepatocellular carcinoma outcomes (46% vs 8%, respectively) and with a hepatocellular carcinoma (10% vs 3%, respectively) than RFSP slope < 02 (249 patients, 72.4%) (P < .0001). RFSP and screening Ishak score correlated independently (P 0.2), which occurred in 26.7% of HALT-C Trial patients, correlated strongly with clinical outcomes.

Human amyloids have been shown to interact with viruses and interfere with viral replication. Based on this observation, we employed a synthetic biology approach in which we engineered virus-specific amyloids against influenza A and Zika proteins. Each amyloid shares a homologous aggregation-prone fragment with a specific viral target protein. For influenza we demonstrate that a designer amyloid against PB2 accumulates in influenza A-infected tissue in vivo. Moreover, this amyloid acts specifically against influenza A and its common PB2 polymorphisms, but not influenza B, which lacks the homologous fragment. Our model amyloid demonstrates that the sequence specificity of amyloid interactions has the capacity to tune amyloid-virus interactions while allowing for the flexibility to maintain activity on evolutionary diverging variants., Some human amyloid proteins have been shown to interact with viral proteins, suggesting that they may have potential as therapeutic agents. Here the authors design synthetic amyloids specific for influenza A and Zika virus proteins, respectively, and show that they can inhibit viral replication.