MiR-590-3p Promotes the Phenotypic Switching of Vascular Smooth Muscle Cells by Targeting Lysyl Oxidase.

ABSTRACT: We investigated the clinical characteristics of patients with acute aortic dissection (AAD) and miR-590-3p levels in serum, tissue, and vascular smooth muscle cells. The effect of miR-590-3p on the vascular smooth muscle cell phenotype was assessed, and the regulation of lysyl oxidase by miR-5903p was determined. C57BL/6 mice were used to investigate the incidence of AAD and effects of miR-5903p on AAD. The miR-590-3p levels were measured in the aortae of mice, and hematoxylin and eosin staining and Masson staining were performed to identify the morphological features of the aorta. Comparative analysis revealed significant differences in clinical characteristics between patients with AAD and healthy control subjects, with most patients with AAD exhibiting concomitant hypertension and nearly 50% having atherosclerosis. Lysyl oxidase was a direct target of miR-590-3p. Lysyl oxidase overexpression inhibited switching of the vascular smooth muscle cell phenotype from contractile to synthetic, but miR-590-3p overexpression significantly reversed this change. In the mouse model, miR-590-3p upregulation increased the incidence of AAD to 93.3%, and its incidence decreased to 13.3% after miR-590-3p inhibition. Hematoxylin and eosin and Masson staining revealed that the miR-590-3p agomiR group had a greater loss of the contractile phenotype in the dissected aortic wall and an increased number of muscle fibers in the aortic wall, which contributed to thickening of the aortic wall and the formation of a false lumen in aortic dissection. miR-590-3p might be pivotal in the pathogenesis of AAD. Thus, targeting miR-590-3p or its downstream pathways could represent a therapeutic approach for AAD.

MiR-4787-5p Regulates Vascular Smooth Muscle Cell Apoptosis by Targeting PKD1 and Inhibiting the PI3K/Akt/FKHR Pathway.

ABSTRACT: Vascular smooth muscle cell (VSMC) dysfunction is the main cause of aortic dissection (AD). In this study, we focused on the role and mechanism of miR-4787-5p in regulating VSMC apoptosis. Real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of miR-4787-5p in aorta tissues of AD (n = 10) and normal aortic tissues of donors (n = 10). Cell apoptosis was tested by TUNEL assay and Annexin V FITC/PI staining flow cytometry. The expression of PC1 and the PI3K/Akt/FKHR signaling pathway associated proteins in VSMCs was measured by Western blot. We found that the miR-4787-5p was highly expressed in aorta tissues of AD compared with 10 healthy volunteers. Meanwhile, PI3K/Akt/FKHR signaling pathway was inactive in the aortic tissue of AD. The overexpression of miR-4787-5p significantly induced VSMC apoptosis, and miR-4787-5p knockdown showed the opposite results. In addition, polycystic kidney disease 1 gene, which encodes polycystin-1 (PC1), was found to be a direct target of miR-4787-5p in the VSMCs and this was validated using a luciferase reporter assay. Overexpression of PC1 by a lentivirus packaging PC1-overexpression plasmid (LV-PC1) plasmids markedly eliminated the promotion of miR-4787-5p overexpression on VSMC apoptosis. Finally, it was found that miR-4787-5p deactivated the PI3K/Akt/FKHR pathway, as demonstrated by the down-regulation of phosphorylated (p-)PI3K, p-Akt, and p-FKHR. In conclusion, these findings confirm an important role for the miR-4787-5p/polycystic kidney disease 1 axis in AD pathobiology.

FMO1 gene expression independently predicts favorable recurrence-free survival of classical papillary thyroid cancer.

Aim: To examine the expression profile of FMO1 in papillary thyroid cancer (PTC) and its prognostic value in recurrence-free survival (RFS). Methods: A retrospective analysis was performed using data from the Cancer Genome Atlas and Human Protein Atlas. Results: The most frequent variants of PTC had decreased FMO1 expression compared with their respective adjacent normal tissues. However, even under the best cut-off model, high FMO1 expression was only significantly associated with better RFS in classical PTC (p < 0.001), but not in other two variants. High FMO1 expression independently predicted favorable RFS (hazard ratio: 0.202; 95% CI: 0.084-0.487; p < 0.001) in classical PTC. Conclusion: High FMO1 expression might serve as a biomarker that independently predicts favorable RFS in classical PTC patients.

Safety of Stenting and Endarterectomy for Asymptomatic Carotid Artery Stenosis: A Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE/BACKGROUND: A meta-analysis of recently published randomised controlled trials (RCTs) was performed to evaluate the safety of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) for asymptomatic carotid stenosis with average risk. METHODS: The MEDLINE, Embase, and Cochrane Library databases were systematically searched for RCTs that compared CAS with CEA for asymptomatic carotid stenosis. These publications reported clinical outcomes after revascularisation in patients with asymptomatic carotid stenosis during their primary intervention. Trials published in English were searched for on 31 May 2017. End points (composite of ipsilateral stroke, any stroke, major stroke, minor stroke, myocardial infarction [MI], and death during the post-procedural period) were extracted from the publications by two reviewers. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for peri-operative outcomes following CAS and CEA using a fixed effects model. RESULTS: Five studies involving 3901 patients (1585 with CEA; 2316 with CAS) were included in the meta-analysis. The risk of any stroke during the peri-procedural period was significantly lower in patients who underwent CEA than CAS (OR 0.53; 95% CI 0.29-0.96). The difference between CAS and CEA in the rate of stroke could be driven by minor stroke (OR 0.50; 95% CI 0.25-1.00). The risk of death, major stroke, ipsilateral stroke, and MI were not significantly different between the two interventions (peri-procedural death: OR 1.49 [95% CI 0.26-8.68]; peri-procedural major stroke: OR 0.69 [95% CI 0.20-2.35]; peri-procedural ipsilateral stroke: OR 0.63 [95% CI 0.27-1.47]; peri-procedural MI: OR 1.75 [95% CI 0.84-3.65]). No robust conclusion could be drawn regarding mid to long-term complications because of the heterogeneity of the reported data. The different outcomes precluded any further analysis being conducted. CONCLUSION: Among patients with asymptomatic carotid stenosis, stenting has a significantly higher rate of any peri-procedural stroke and peri-procedural minor stroke than CEA, and similar risk of peri-procedural major stroke, peri-procedural ipsilateral stroke, or MI.

Amino acid metabolism in tumor biology and therapy.

Amino acid metabolism plays important roles in tumor biology and tumor therapy. Accumulating evidence has shown that amino acids contribute to tumorigenesis and tumor immunity by acting as nutrients, signaling molecules, and could also regulate gene transcription and epigenetic modification. Therefore, targeting amino acid metabolism will provide new ideas for tumor treatment and become an important therapeutic approach after surgery, radiotherapy, and chemotherapy. In this review, we systematically summarize the recent progress of amino acid metabolism in malignancy and their interaction with signal pathways as well as their effect on tumor microenvironment and epigenetic modification. Collectively, we also highlight the potential therapeutic application and future expectation.

The deubiquitinase BAP1 and E3 ligase UBE3C sequentially target IRF3 to activate and resolve the antiviral innate immune response.

Ubiquitination is essential for the proteasomal turnover of IRF3, the central factor mediating the antiviral innate immune response. However, the spatiotemporal regulation of IRF3 ubiquitination for the precise activation and timely resolution of innate immunity remains unclear. Here, we identified BRCA1-associated protein-1 (BAP1) and ubiquitin-protein ligase E3C (UBE3C) as the key deubiquitinase and ubiquitinase for temporal control of IRF3 stability during viral infection. In the early stage, BAP1 dominates and removes K48-linked ubiquitination of IRF3 in the nucleus, preventing its proteasomal degradation and facilitating efficient interferon (IFN)-ß production. In the late stage, E3 ligase UBE3C, induced by IFN-ß, specifically mediates IRF3 ubiquitination and promotes its proteasomal degradation. Overall, the sequential interactions with BAP1 and UBE3C govern IRF3 stability during innate response, ensuring effective viral clearance and inflammation resolution. Our findings provide insights into the temporal control of innate signaling and suggest potential interventions in viral infection.

Circular RNA PTP4A2 regulates microglial polarization through STAT3 to promote neuroinflammation in ischemic stroke.

OBJECTIVE: Microglial polarization plays a critical role in neuroinflammation and may be a potential therapeutic target for ischemic stroke. This study was to explore the role and underlying molecular mechanism of Circular RNA PTP4A2 (circPTP4A2) in microglial polarization after ischemic stroke. METHODS: C57BL/6J mice underwent transient middle cerebral artery occlusion (tMCAO), while primary mouse microglia and BV2 microglial cells experienced oxygen glucose deprivation/reperfusion (OGD/R) to mimic ischemic conditions. CircPTP4A2 shRNA lentivirus and Colivelin were used to knock down circPTP4A2 and upregulate signal transducer and activator of transcription 3 (STAT3) phosphorylation, respectively. Microglial polarization was assessed using immunofluorescence staining and Western blot. RNA pull-down and RNA binding protein immunoprecipitation (RIP) were applied to detect the binding between circPTP4A2 and STAT3. RESULTS: The levels of circPTP4A2 were significantly increased in plasma and peri-infarct cortex in tMCAO mice. CircPTP4A2 knockdown reduced infarct volume, increased cortical cerebral blood flow (CBF), and attenuated neurological deficits. It also decreased pro-inflammatory factors levels in peri-infarct cortex and plasma, and increased anti-inflammatory factors concentrations 24 h post-stroke. In addition, circPTP4A2 knockdown suppressed M1 microglial polarization and promoted M2 microglial polarization in both tMCAO mice and OGD/R-induced BV2 microglial cells. Moreover, circPTP4A2 knockdown inhibited the phosphorylation of STAT3 induced by oxygen-glucose deprivation. In contrast, increased phosphorylation of STAT3 partly counteracted the effects of circPTP4A2 knockdown. RNA pull-down and RIP assays further certified the binding between circPTP4A2 and STAT3. CONCLUSION: These results revealed regulatory mechanisms of circPTP4A2 that stimulated neuroinflammation by driving STAT3-dependent microglial polarization in ischemic brain injury. CircPTP4A2 knockdown reduced cerebral ischemic injury and promoted microglial M2 polarization, which could be a novel therapeutic target for ischemic stroke.

DMT1 ubiquitination by Nedd4 protects against ferroptosis after intracerebral hemorrhage.

OBJECTIVE: Neuronal precursor cells expressed developmentally down-regulated 4 (Nedd4) are believed to play a critical role in promoting the degradation of substrate proteins and are involved in numerous biological processes. However, the role of Nedd4 in intracerebral hemorrhage (ICH) remains unknown. This study aims to investigate the regulatory role of Nedd4 in the ICH model. METHODS: Male C57BL/6J mice were induced with ICH. Subsequently, the levels of glutathione peroxidase 4 (GPX4), malondialdehyde (MDA) concentration, iron content, mitochondrial morphology, as well as the expression of divalent metal transporter 1 (DMT1) and Nedd4 were assessed after ICH. Furthermore, the impact of Nedd4 overexpression was evaluated through analyses of hematoma area, ferroptosis, and neurobehavioral function. The mechanism underlying Nedd4-mediated degradation of DMT1 was elecidated using immunoprecipitation (IP) after ICH. RESULTS: Upon ICH, the level of DMT1 in the brain increased, but decreased when Nedd4 was overexpressed using Lentivirus, suggesting a negative correlation between Nedd4 and DMT1. Additionally, the degradation of DMT1 was inhibited after ICH. Furthermore, it was found that Nedd4 can interact with and ubiquitinate DMT1 at lysine residues 6, 69, and 277, facilitating the degradation of DMT1. Functional analysis indicated that overexpression of Nedd4 can alleviate ferroptosis and promote recovery following ICH. CONCLUSION: The results demonstrated that ferroptosis occurs via the Nedd4/DMT1 pathway during ICH, suggesting it potential as a valuable target to inhibit ferroptosis for the treatment of ICH.

Systematic Pan-Cancer Analysis Reveals X-C Motif Chemokine Receptor 1 as a Prognostic and Immunological Biomarker.

Chemokines and their receptors play an important role in immune monitoring and immune defense during tumor growth and metastasis. However, their prognostic roles in pan-cancer have not been elucidated. In this work, we screened all chemokine receptors in pan-cancer and discovered X-C Motif Chemokine Receptor 1 (XCR1) as a reliable immunological and prognostic biomarker in pan-cancer using bioinformation. The TCGA database served as the foundation for the primary research database analysis in this work. XCR1 was downregulated in tumors. Patients with reduced XCR1 showed worse prognoses and a concomitant decrease in immune cell infiltration (DCs and CD8+ T cells). According to a gene enrichment study, XCR1 enhanced immune system performance by promoting T-cell infiltration through the C-X-C Motif Chemokine Ligand 9 (CXCL9)- C-X-C Motif Chemokine Receptor 3 (CXCR3) axis. In addition, XCR1 is mainly expressed in infiltrated DCs and some malignant cells in tumor tissues. Our data revealed the important role of XCR1 in remodeling the tumor microenvironment and predicting the survival prognosis, which could also be used as a sensitive biomarker for tumor immunotherapy.

Performance of next-generation sequencing for diagnosis of blood infections by Klebsiella pneumoniae.

Objective: Klebsiella pneumoniae (Kp) bloodstream infections (BSI) can be a life-threatening opportunistic infection. We aimed to evaluate the diagnostic accuracy of metagenomic next-generation sequencing (mNGS) for Kp BSI. Methods: We retrospectively analyzed 72 patients suspected with bloodstream infection and mNGS Kp positive in peripheral blood, who were hospitalized in our hospital from January 2022 to January 2023. Clinical data and laboratory parameters were collected. All patients had blood drawn and other samples for blood mNGS, blood cultures (BC) and other cultures (OC). The accuracy of mNGS results was analyzed according to infection site, clinical indicators, therapeutic effect and routine culture results. The detection of pathogenic microorganisms by blood mNGS and routine culture was compared. Results: Among 72 infection patients, 29 cases (40.28%) were BC positive, 43 cases (59.72%) were other culture (OC) positive, 16 cases (22.22%) were both BC and OC positive, 56 cases were positive for both mNGS and routine culture. Among the 56 double-positive cases, mNGS and conventional cultures were completely consistent in 27 cases, partially consistent in 15 cases, and completely inconsistent in 14 cases. Using the clinical diagnosis as the reference standard, There were 51 cases consistent with the results of mNGS with Kp BSI, the clinical consistency was 70.83% (51/72). The coincidence rate of mNGS and clinical diagnosis was higher than that of BC (54.17%, 39/72), indicating a statistically significant difference between the two methods (P<0.01). Conclusions: Current evidence indicates that mNGS exhibits excellent accuracy for the diagnosis of Kp BSI. Although it cannot replace blood culture detection technology, it can be used as a supplement to provide stronger diagnostic capabilities for BSI and optimize treatment.

Increased plasma levels of circPTP4A2 and circTLK2 are associated with stroke injury.

OBJECTIVE: Accumulating studies have shown that circulating circular RNAs (circRNAs) represent novel biomarkers for many human diseases. We investigated whether plasma circPTP4A2 and circTLK2 levels are associated with stroke severity, infarct volume, stroke etiology, and functional outcome in acute ischemic stroke (AIS) patients. METHODS: We applied quantitative real-time PCR (qPCR) to measure plasma circPTP4A2 and circTLK2 levels of 236 AIS patients within 72 h of symptoms onset and 136 healthy controls. We further assessed the National Institutes of Health Stroke Scale (NIHSS), infarct size, the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification and the 90-day modified Rankin scale (mRS) for each patient. RESULTS: At admission, plasma circPTP4A2 and circTLK2 levels in patients with moderate to severe stroke were significantly higher compared to those with mild stroke. Logistic regression and receiver-operating characteristic (ROC) curve analyses indicated that they might function as predictive biomarkers for moderate to severe stroke. We also observed a medium positive correlation between these two circRNAs and NIHSS. Plasma circPTP4A2 and circTLK2 levels were slight positively correlated with cerebral infarct volume only in anterior circulation infarction (ACI) patients. Levels of both circPTP4A2 and circTLK2 were closely related with large artery atherosclerosis (LAA) stroke. Moreover, changes within 7 days after admission in circPTP4A2 and circTLK2 were able to predict unfavorable clinical outcome 90 days after AIS. INTERPRETATION: These results demonstrate that plasma circPTP4A2 and circTLK2 strongly correlated with severity, subtypes and prognosis of AIS, and they could serve as promising biomarkers.

Clonal Distribution and Intratumor Heterogeneity of the TCR Repertoire in Papillary Thyroid Cancer With or Without Coexistent Hashimoto's Thyroiditis.

The intratumor heterogeneity (ITH) of the amount and TCR repertoires of tumor infiltrating lymphocytes (TILs) in PTC with and without coexistent Hashimoto's thyroiditis (HT) are unclear. Here, we investigated the amount of T cells in tumor and corresponding normal tissues by immunohistochemical staining on 80 tumor samples and 40 normal samples from 40 patients. The immune repertoire of T cells was identified on 24 tumor samples and 12 normal samples from 12 patients using TCR high-throughput sequencing. The results demonstrated that the numbers of CD3+, CD4+ and CD8+ T cells in PTC without coexistent HT (PTC-WO) were significantly lower than those in PTC with existing HT (PTC-W). In PTC-W, the density of CD4+ TILs were generally higher when compared with CD8+ TILs. Furthermore, we found that the numbers of CD3+ T cells and their CD4+, CD8+ subtypes in tumor samples were generally higher than those in normal tissue in PTC-WO and moreover, the number of CD3+ T cells was negatively associated with TCR clonality in PTC-WO. In addition, although ITH of the TCR repertoire truly existed in PTC-W and PTC-WO, the TCR repertoires between distinct regions of the non-adjacent tumor foci were presented with a higher degree of similarity than those between tumor and matched normal tissue in PTC-WO, yet the similarity of intratumor repertoires was not significantly higher than those between tumor and corresponding normal samples in PTC-W. This research comprehensively delineated the quantity and TCR repertoire ITH of T cells in PTC-W and PTC-WO, suggesting that TILs might be reactive to tumor antigens in PTC-WO. Moreover, multiregion biopsies should be performed to precisely identify the immune background in PTC-W and PTC-WO.

Quasi-Static Mechanical Properties and Continuum Constitutive Model of the Thyroid Gland.

The purpose of this study is to obtain the digital twin parameters of the thyroid gland and to build a constitutional model of the thyroid gland based on continuum mechanics, which will lay the foundation for the establishment of a surgical training system for the thyroid surgery robot and the development of the digital twin of the thyroid gland. First, thyroid parenchyma was obtained from fresh porcine thyroid tissue and subjected to quasi-static unconfined uniaxial compression tests using a biomechanical test platform with two strain rates (0.005 s-1 and 0.05 s-1) and two loading orientations (perpendicular to the thyroid surface and parallel to the thyroid surface). Based on this, a tensile thyroid model was established to simulate the stretching process by using the finite element method. The thyroid stretching test was carried out under the same parameters to verify the validity of the hyperelastic constitutive model. The quasi-static mechanical property parameters of the thyroid tissue were obtained by a quasi-static unconstrained uniaxial compression test, and a constitutional model that can describe the quasi-static mechanical properties of thyroid tissue was proposed based on the principle of continuum media mechanics, which is of great value for the establishment of a surgical training system for the head and neck surgery robot and for the development of the thyroid digital twin.

Clinical outcomes of multifocal papillary thyroid cancer: A systematic review and meta-analysis.

Objective: Papillary thyroid cancer (PTC) is the most common endocrine malignancy with a steadily increasing incidence. Researches have reported that tumor multifocality occurs in an extensive number of cases. Nevertheless, the clinical characteristics and prognostic value remained controversial. This study was performed to investigate the relationship between multifocal PTC and adverse clinicopathologic features and the prognosis. Methods: A systematic review and meta-analysis were conducted based on three electronic databases up to December 31, 2021. Parameters of interest included five clinical features (extrathyroidal extension, lymphovascular invasion, central lymph node metastasis, lateral lymph node metastasis, distant metastasis) and were pooled into risk ratios (RRs). Time-to-event data (recurrence-free survival and all-cause mortality) were evaluated using hazard ratios (HRs). Publication bias was examined using funnel plots and Egger's test. Results: A total of 23 articles were included according to the inclusion criteria; all of the studies were retrospective cohorts. In comparison with unifocality, multifocality showed an increased risk of extrathyroidal extension (RR 1.38, 95% CI 1.25-1.53), lymphovascular invasion (RR 1.27, 95% CI 1.04-1.55), central lymph node metastasis (RR 1.21, 95% CI 1.12-1.30), lateral lymph node metastasis (RR 1.86, 95% CI 1.62-2.14), and distant metastasis (RR 1.35, 95% CI 1.03-1.76). Multifocal patients were predisposed to postoperative recurrence (HR 1.76, 95% CI 1.50-2.07). The rate of all-cause mortality did not reach a statistical difference. Level of Evidence: 2. Conclusion: Multifocal PTC is more aggressive in contrast to unifocal PTC and is accompanied by an increased risk of recurrence. They were usually diagnosed in higher grades and stages. To achieve the maximal benefit, we recommend personalized therapy and close follow-up for multifocal PTC patients. Further prospective studies will clarify the best-fitted treatment plans.

Metabolic reprogramming by ex vivo glutamine inhibition endows CAR-T cells with less-differentiated phenotype and persistent antitumor activity.

The inadequate in vivo persistence of chimeric antigen receptor (CAR)-modified T cells has been shown to lead to poor therapeutic efficacy and disease recurrence. In vivo persistence is associated with the differentiation subsets infused, with less differentiated TN or TCM conferring superior renewal capacity and antitumor immunity compared to TEM or TEFF. However, ex vivo expanded CAR-T cells exhibit phenotypic heterogeneity with majority of TEM or TEFF subsets and very low populations of TN and TCM. The transition of differentiation subsets is closely correlated with T cell metabolism fitness. Effector T cell differentiation from TN or TCM requires glutamine uptake and metabolism. Using a CD19-specific CAR, we demonstrated that glutamine inhibition by adding the glutamine antagonist 6-Diazo-5-oxo-l-norleucine (DON) into the culture endows CAR-T cells with enhanced mitochondrial OXPHOS utilizing fatty acids and reduced glycolytic activity, and retains more TN or TCM subsets. DON- pretreated CAR-T cells exhibited stronger cytotoxic lysis in vitro and more robust elimination of tumor burdens in vivo. This study suggests that glutamine inhibition ex vivo would be a potential approach for modulating metabolism and differentiation state to improve the efficacy of CAR-T cell therapy.

Evidence of anti-inflammatory activity of Schizandrin A in animal models of acute inflammation.

Schisandrin A (Sch A) is a lignin extracted from the fruit of Schisandra chinensis, which has potential anti-inflammatory properties and is used for treating various inflammatory diseases. In this study, we aimed to evaluate the anti-inflammatory effects of Sch A and the underlying mechanisms in animal models of acute inflammation. First, the anti-inflammatory effects of Sch A were evaluated preliminarily in an animal model of xylene-induced ear edema. Sch A pretreatment significantly decreased the degree of edema and inhibited telangiectasia in the ear. Second, a mouse model of paw edema was used to investigate the anti-inflammatory effects and mechanisms of Sch A. Pretreatment with Sch A significantly inhibited carrageenan-induced paw edema in mice. Hematoxylin-eosin (HE) staining of paw tissues demonstrated that Sch A inhibited the infiltration of inflammatory cells in the mouse model of paw edema. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of inflammatory factors decreased. The western blot and immunohistochemical assay results revealed that the toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) pathway could play a role in the anti-inflammatory functions of Sch A. The findings demonstrated that Sch A exerts anti-inflammatory effects and may provide possible strategies for the treatment of inflammatory diseases.

MHC Class I Molecules Exacerbate Viral Infection by Disrupting Type I Interferon Signaling.

MHC class I molecules are key in the presentation of antigen and initiation of adaptive CD8+ T cell responses. In addition to its classical activity, MHC I may possess nonclassical functions. We have previously identified a regulatory role of MHC I in TLR signaling and antibacterial immunity. However, its role in innate antiviral immunity remains unknown. In this study, we found a reduced viral load in MHC I-deficient macrophages that was independent of type I IFN production. Mechanically, MHC I mediated viral suppression by inhibiting the type I IFN signaling pathway, which depends on SHP2. Cross-linking MHC I at the membrane increased SHP2 activation and further suppressed STAT1 phosphorylation. Therefore, our data revealed an inhibitory role of MHC I in type I IFN response to viral infection and expanded our understanding of MHC I and antigen presentation.

Real-time imaging of Pt3Fe nanorod growth in solution.

The growth of colloidal nanocrystal architectures by nanoparticle attachment is frequently reported as an alternative to the conventional growth by monomer attachment. However, the mechanism whereby nanoparticle attachment proceeds microscopically remains unclear. We report real-time transmission electron microscopy (TEM) imaging of the solution growth of Pt(3)Fe nanorods from nanoparticle building blocks. Observations revealed growth of winding polycrystalline nanoparticle chains by shape-directed nanoparticle attachment followed by straightening and orientation and shape corrections to yield single-crystal nanorods. Tracking nanoparticle growth trajectories allowed us to distinguish the force fields exerted by single nanoparticles and nanoparticle chains. Such quantification of nanoparticle interaction and understanding the growth pathways are important for the design of hierarchical nanomaterials and controlling nanocrystal self-assembly for functional devices.