Controlled Genetic Encoding of Unnatural Amino Acids in a Protein Nanopore.

Conventional protein engineering methods for modifying protein nanopores are typically limited to 20 natural amino acids, which restrict the diversity of the nanopores in structure and function. To enrich the chemical environment inside the nanopore, we employed the genetic code expansion (GCE) technique to site-specifically incorporate the unnatural amino acid (UAA) into the sensing region of aerolysin nanopores. This approach leveraged the efficient pyrrolysine-based aminoacyl-tRNA synthetase-tRNA pair for a high yield of pore-forming protein. Both molecular dynamics (MD) simulations and single-molecule sensing experiments demonstrated that the conformation of UAA residues provided a favorable geometric orientation for the interactions of target molecules and the pore. This rationally designed chemical environment enabled the direct discrimination of multiple peptides containing hydrophobic amino acids. Our work provides a new framework for endowing nanopores with unique sensing properties that are difficult to achieve using classical protein engineering approaches.

Serum netrin-1 serves as a prognostic biomarker of aneurysmal subarachnoid hemorrhage.

BACKGROUND: Netrin-1 exhibits anti-inflammatory properties. Netrin-1 could alleviate brain injury of subarachnoid hemorrhage (SAH) rat. This study was designed to discern the utility of serum netrin-1 as a biomarker for assessing the severity and prognosis of patients with aneurysmal SAH. METHODS: Netrin-1 concentrations were gauged in serum from 104 patients and 104 controls. Hemorrhagic clinical and radiological severity was assessed utilizing World Federation of Neurological Surgeons (WFNS) score, modified Fisher score, and Hunt Hess score. Glasgow Outcome Scale (GOS) score was recorded at 6 months after SAH. GOS score of 1-3 was considered as a poor outcome. RESULTS: Patients showed substantially lower serum netrin-1 concentrations than controls (median, 237.9 pg/ml; interquartile range, 189.6-271.2 pg/ml vs. median, 815.4 pg/ml; interquartile range, 581.8-990.4 pg/ml). Netrin-1 concentrations were independently correlated with WNFS score, modified Fisher score, Hunt Hess score and serum C-reactive protein concentrations (t = -4.667, -3.792, -4.304 and - 3.549 respectively). Area under ROC curve was 0.837 (95% CI, 0.752-0.902) for predicting 6-month poor prognosis. Serum netrin-1 concentrations <229.3 pg/ml emerged as an independent prognostic predictor (odds ratio, 14.316; 95% confidence interval, 5.032-40.726). CONCLUSIONS: Serum netrin-1 might represent a potential biomarker for reflecting severity, inflammation and prognosis of human aneurysmal SAH.

Association Between BRAFV600E Mutation and the American College of Radiology Thyroid Imaging, Reporting and Data System in Solitary Papillary Thyroid Carcinoma.

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate the associations between BRAFV600E mutation, the American College of Radiology (ACR) thyroid imaging, reporting and data system (TI-RADS) on ultrasound and clinicopathological characteristics in patients with a solitary papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: This retrospective study included 397 patients with a solitary PTC, proved pathologically. BRAFV600E mutation status was detected in postoperative samples by real-time fluorescent polymerase chain reaction. Associations of BRAFV600E mutation with the ACR TI-RADS and clinicopathological characteristics were analyzed. RESULTS: In this study, the incidence of BRAFV600E mutation was 81.4% (323/397) in patients with a solitary PTC. Univariate analyses showed that BRAFV600E mutation was significantly associated with margin, higher ACR TI-RADS point scores, and Hashimoto's thyroiditis. In multivariate analyses, lobulated or irregular margin was independently associated with BRAFV600E mutation in total solitary PTC. Furthermore, both in total solitary PTC and papillary thyroid microcarcinoma, BRAFV600E mutation was associated with ACR TI-RADS point scores, which was positively correlated with the risk of BRAFV600E mutation. There was no significant relationship between BRAFV600E mutation and ACR TI-RADS point scores in PTC >10 mm. In addition, Hashimoto's thyroiditis had a significant negative association with BRAFV600E mutation. CONCLUSION: A lobulated or irregular margin of the thyroid nodule is independently associated with BRAFV600E mutation in patients with PTC. In addition, higher ACR TI-RADS point scores is an independent risk factor for BRAFV600E mutation, and ACR TI-RADS point scores is positively associated with the risk of BRAFV600E mutation in solitary PTC, especially in papillary thyroid microcarcinoma. Our findings may be helpful for preoperative identification and medical management of PTC patients with BRAFV600E mutation.

The NLRP3 Inflammasome: An Important Driver of Neuroinflammation in Hemorrhagic Stroke.

Hemorrhagic stroke is a devastating clinical event with no effective medical treatment. Neuroinflammation, which follows a hemorrhagic stroke, is an important element that involves both acute brain injury and subsequent brain rehabilitation. Therefore, delineating the key inflammatory mediators and deciphering their pathophysiological roles in hemorrhagic strokes is of great importance in the development of novel therapeutic targets for this disease. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a multi-protein complex that is localized within the cytoplasm. This NOD-like receptor orchestrates innate immune responses to pathogenic organisms and cell stress through the activation of caspase-1 and the maturation of the proinflammatory cytokines such as interleukin-1ß (IL-1ß) and IL-18. Mounting evidence has demonstrated that when the NLRP3 inflammasome is activated, it exerts harmful effects on brain tissue after a hemorrhagic stroke. This review article summarizes the current knowledge regarding the role and the underlying mechanisms of the NLRP3 inflammasome in the pathophysiological processes of hemorrhagic strokes. A better understanding of the function and regulation of the NLRP3 inflammasome in hemorrhagic strokes will provide clues for devising novel therapeutic strategies to fight this disease.

The role of lateral habenula-dorsal raphe nucleus circuits in higher brain functions and psychiatric illness.

Serotonergic neurons in the dorsal raphe nucleus (DRN) play an important role in regulation of many physiological functions. The lateral nucleus of the habenular complex (LHb) is closely connected to the DRN both morphologically and functionally. The LHb is a key regulator of the activity of DRN serotonergic neurons, and it also receives reciprocal input from the DRN. The LHb is also a major way-station that receives limbic system input via the stria medullaris and provides output to the DRN and thereby indirectly connects a number of other brain regions to the DRN. The complex interactions of the LHb and DRN contribute to the regulation of numerous important behavioral and physiological mechanisms, including those regulating cognition, reward, pain sensitivity and patterns of sleep and waking. Disruption of these functions is characteristic of major psychiatric illnesses, so there has been a great deal of interest in how disturbed LHb-DRN interactions may contribute to the symptoms of these illnesses. This review summarizes recent research related to the roles of the LHb-DRN system in regulation of higher brain functions and the possible role of disturbed LHb-DRN function in the pathogenesis of psychiatric disorders, especially depression.

Postattachment events associated with viral entry are necessary for induction of interferon-stimulated genes by human cytomegalovirus.

Utilizing a human cytomegalovirus-specific fusion inhibitor and an antiglycoprotein H antibody, we studied the role of virion fusion in interferon-stimulated gene (ISG) induction. Our results indicate that ISG induction does not occur when virion-mediated, post-high-affinity attachment events are inhibited by either reagent. Thus, virion-mediated postattachment events, such as fusion, are required for ISG induction.