The PARN, TOE1, and USB1 RNA deadenylases and their roles in non-coding RNA regulation.

The levels of non-coding RNAs (ncRNAs) are regulated by transcription, RNA processing, and RNA degradation pathways. One mechanism for the degradation of ncRNAs involves the addition of oligo(A) tails by non-canonical poly(A) polymerases, which then recruit processive sequence-independent 3' to 5' exonucleases for RNA degradation. This pathway of decay is also regulated by three 3' to 5' exoribonucleases, USB1, PARN, and TOE1, which remove oligo(A) tails and thereby can protect ncRNAs from decay in a manner analogous to the deubiquitination of proteins. Loss-of-function mutations in these genes lead to premature degradation of some ncRNAs and lead to specific human diseases such as Poikiloderma with Neutropenia (PN) for USB1, Dyskeratosis Congenita (DC) for PARN and Pontocerebellar Hypoplasia type 7 (PCH7) for TOE1. Herein, we review the biochemical properties of USB1, PARN, and TOE1, how they modulate ncRNA levels, and their roles in human diseases.

Pushing boundaries: mechanisms enabling bacterial pathogens to spread between cells.

For multiple intracellular bacterial pathogens, the ability to spread directly into adjacent epithelial cells is an essential step for disease in humans. For pathogens such as Shigella, Listeria, Rickettsia, and Burkholderia, this intercellular movement frequently requires the pathogens to manipulate the host actin cytoskeleton and deform the plasma membrane into structures known as protrusions, which extend into neighboring cells. The protrusion is then typically resolved into a double-membrane vacuole (DMV) from which the pathogen quickly escapes into the cytosol, where additional rounds of intercellular spread occur. Significant progress over the last few years has begun to define the mechanisms by which intracellular bacterial pathogens spread. This review highlights the interactions of bacterial and host factors that drive mechanisms required for intercellular spread with a focus on how protrusion structures form and resolve.

NaI-Mediated Electrochemical Cyclization-Desulfurization for the Synthesis of N-Substituted 2-Aminobenzimidazoles.

An electrochemical method for the synthesis of N-substituted 2-aminobenzimidazoles through a NaI-mediated desulfurization-cyclization process is reported. This electrosynthesis method utilizes cost-effective NaI as both a mediator and an electrolyte in a catalytic amount (0.2 equiv), replacing traditional oxidizing reagents. N-Substituted o-phenylenediamines and isothiocyanates undergo a thiourea formation/cyclization/desulfurization process to provide N-substituted 2-aminobenzimidazoles (55 examples, up to 98% yield) in a single reaction vessel. Importantly, this electrochemical methodology is applicable to gram-scale synthesis, maintaining reaction efficiency.

RNA partitioning into stress granules is based on the summation of multiple interactions.

Stress granules (SGs) are stress-induced RNA-protein assemblies formed from a complex transcriptome of untranslating ribonucleoproteins (RNPs). Although RNAs can be either enriched or depleted from SGs, the rules that dictate RNA partitioning into SGs are unknown. We demonstrate that the SG-enriched NORAD RNA is sufficient to enrich a reporter RNA within SGs through the combined effects of multiple elements. Moreover, artificial tethering of G3BP1, TIA1, or FMRP can target mRNAs into SGs in a dose-dependent manner with numerous interactions required for efficient SG partitioning, which suggests individual protein interactions have small effects on the SG partitioning of mRNPs. This is supported by the observation that the SG transcriptome is largely unchanged in cell lines lacking the abundant SG RNA-binding proteins G3BP1 and G3BP2. We suggest the targeting of RNPs into SGs is due to a summation of potential RNA-protein, protein-protein, and RNA-RNA interactions with no single interaction dominating RNP recruitment into SGs.

N-Terminal pro-Brain Natriuretic Peptide is a biomarker for cardiovascular damage in systemic lupus erythematous: a cross-sectional study.

OBJECTIVES: Prediction models based on traditional risk factors underestimate cardiovascular (CV) risk in systemic lupus erythematosus (SLE). In a large sample of unselected SLE patients, we investigated cross-sectional associations of NT-proBNP with cardiovascular damage (CVD). METHODS: Serum NT-proBNP was measured in SLE patients enrolled in the MUHC Lupus Clinic registry. Serum were collected between March 2022 and April 2023 at annual research visits. The primary outcome was CVD identified on the SLICC Damage Index. Factors associated with CVD and NT-proBNP levels were determined. RESULTS: Overall, 270 SLE patients (female 91%, median age 50.7 [1st quartile- 3rd quartile : 39.6-62.1] years) were analyzed for the primary outcome. Among them, 33 (12%) had CVD. The ROC curve for NT-proBNP demonstrated strong associations with CVD (AUC 0.78, 95% CI 0.69-0.87) with a threshold of 133 pg/ml providing the best discrimination for those with/without CVD. Hypertension (OR 3.3, 95% CI 1.2-9.0), dyslipidaemia (OR 3.6, 95% CI 1.3-9.6) and NT-proBNP > 133 pg/ml (OR 7.0, 95% CI, 2.6-19.1) were associated with CVD in the multivariable logistic regression model. Increased NT-proBNP levels were associated with age (OR 4.2, 95% CI 2.2-8.3), ever smoking (OR 1.9, 95% CI 1.0-3.5), reduced eGFR (4.1, 95% CI 1.3-13.1), prior pericarditis/pleuritis (OR 2.5, 95% CI 1.4-4.5) and aPL antibodies (OR 2.6, 95% CI 1.4-4.9). CONCLUSION: NT-proBNP is a biomarker for CV damage in SLE. The novel associations of NT-proBNP levels with prior pericarditis/pleuritis and aPL antibodies suggest new avenues for research to better understand what drives CV risk in SLE.

Electrochemical NaI-mediated one-pot synthesis of guanidines from isothiocyanates via tandem addition-guanylation.

In this study, we present an electrochemical approach for the synthesis of guanidines from isothiocyanates and amines in a single reaction vessel. This one-pot operation takes place in aqueous media, utilizing an undivided cell setup with NaI serving as both the electrolyte and mediator. The process involves the in situ generation of thiourea, followed by electrolytic guanylation with amines. Under ambient temperature conditions, we successfully demonstrated the formation of 30 different guanidine compounds, achieving yields ranging from fair to excellent. Furthermore, the synthesis method could be carried out on a gram scale with a good yield. This protocol stands out for its cost-effectiveness, step-economical design, high tolerance towards various functional groups, and environmentally friendly reaction conditions.

Safety outcomes of rapid- versus standard-infusion rate oxaliplatin.

PURPOSE: The National Comprehensive Cancer Network guidelines state that the oxaliplatin dose of 85 mg/m2 used in various gastrointestinal cancer regimens may be infused over a rapid rate of 85 min instead of the standard time of 120 min. We evaluated the safety outcomes of rapid administration of oxaliplatin compared to standard infusion. METHODS: We performed a retrospective, cohort study by chart review. Adult patients who received oxaliplatin as part of a FOLFOX, FOLFOXIRI, or FOLRINOX chemotherapy regimen from January 1, 2018, through June 30, 2021, were included. Primary outcomes were the incidence of hypersensitivity reaction (HSR) and treatment modification of oxaliplatin due to adverse drug events. Secondary outcomes included peripheral neuropathy (PN), myelosuppressive signs, and oxaliplatin-related emergency department visit and/or hospital admission. RESULTS: A total of 178 patients were included (90 and 88 in the rapid-rate and standard-rate groups, respectively). Rapid-rate oxaliplatin was not associated with increased HSR or difference in toxicity requiring dose reduction, delayed dose, or slowed infusion rate, but was associated with increased rate of permanent discontinuation of oxaliplatin, 7.8% and 1.1% in the rapid-rate group and standard-rate groups, respectively (p = 0.032). Peripheral neuropathy occurred in 72.2% and 42% of patients in the rapid-rate group and standard-rate groups, respectively (relative risk for PN, 2.09; 95%, CI: 1.43-3.04; p < .001). There were no differences in any other adverse drug event measured. CONCLUSION: Rapid-rate oxaliplatin was associated with minimal treatment modifications; however, there was an increase in PN incidence. A faster rate of oxaliplatin administration may not be worth the increased risk of PN.

Regulation of INF2-mediated actin polymerization through site-specific lysine acetylation of actin itself.

INF2 is a formin protein that accelerates actin polymerization. A common mechanism for formin regulation is autoinhibition, through interaction between the N-terminal diaphanous inhibitory domain (DID) and C-terminal diaphanous autoregulatory domain (DAD). We recently showed that INF2 uses a variant of this mechanism that we term "facilitated autoinhibition," whereby a complex consisting of cyclase-associated protein (CAP) bound to lysine-acetylated actin (KAc-actin) is required for INF2 inhibition, in a manner requiring INF2-DID. Deacetylation of actin in the CAP/KAc-actin complex activates INF2. Here we use lysine-to-glutamine mutations as acetylmimetics to map the relevant lysines on actin for INF2 regulation, focusing on K50, K61, and K328. Biochemically, K50Q- and K61Q-actin, when bound to CAP2, inhibit full-length INF2 but not INF2 lacking DID. When not bound to CAP, these mutant actins polymerize similarly to WT-actin in the presence or absence of INF2, suggesting that the effect of the mutation is directly on INF2 regulation. In U2OS cells, K50Q- and K61Q-actin inhibit INF2-mediated actin polymerization when expressed at low levels. Direct-binding studies show that the CAP WH2 domain binds INF2-DID with submicromolar affinity but has weak affinity for actin monomers, while INF2-DAD binds CAP/K50Q-actin 5-fold better than CAP/WT-actin. Actin in complex with full-length CAP2 is predominately ATP-bound. These interactions suggest an inhibition model whereby CAP/KAc-actin serves as a bridge between INF2 DID and DAD. In U2OS cells, INF2 is 90-fold and 5-fold less abundant than CAP1 and CAP2, respectively, suggesting that there is sufficient CAP for full INF2 inhibition.

ACAT1/SOAT1 Blockade Suppresses LPS-Mediated Neuroinflammation by Modulating the Fate of Toll-like Receptor 4 in Microglia.

Cholesterol is stored as cholesteryl esters by the enzymes acyl-CoA:cholesterol acyltransferases/sterol O:acyltransferases (ACATs/SOATs). ACAT1 blockade (A1B) ameliorates the pro-inflammatory responses of macrophages to lipopolysaccharides (LPS) and cholesterol loading. However, the mediators involved in transmitting the effects of A1B in immune cells is unknown. Microglial Acat1/Soat1 expression is elevated in many neurodegenerative diseases and in acute neuroinflammation. We evaluated LPS-induced neuroinflammation experiments in control vs. myeloid-specific Acat1/Soat1 knockout mice. We also evaluated LPS-induced neuroinflammation in microglial N9 cells with and without pre-treatment with K-604, a selective ACAT1 inhibitor. Biochemical and microscopy assays were used to monitor the fate of Toll-Like Receptor 4 (TLR4), the receptor at the plasma membrane and the endosomal membrane that mediates pro-inflammatory signaling cascades. In the hippocampus and cortex, results revealed that Acat1/Soat1 inactivation in myeloid cell lineage markedly attenuated LPS-induced activation of pro-inflammatory response genes. Studies in microglial N9 cells showed that pre-incubation with K-604 significantly reduced the LPS-induced pro-inflammatory responses. Further studies showed that K-604 decreased the total TLR4 protein content by increasing TLR4 endocytosis, thus enhancing the trafficking of TLR4 to the lysosomes for degradation. We concluded that A1B alters the intracellular fate of TLR4 and suppresses its pro-inflammatory signaling cascade in response to LPS.

Stealth Liposomes Encapsulating a Potent ACAT1/SOAT1 Inhibitor F12511: Pharmacokinetic, Biodistribution, and Toxicity Studies in Wild-Type Mice and Efficacy Studies in Triple Transgenic Alzheimer's Disease Mice.

Cholesterol is essential for cellular function and is stored as cholesteryl esters (CEs). CEs biosynthesis is catalyzed by the enzymes acyl-CoA:cholesterol acyltransferase 1 and 2 (ACAT1 and ACAT2), with ACAT1 being the primary isoenzyme in most cells in humans. In Alzheimer's Disease, CEs accumulate in vulnerable brain regions. Therefore, ACATs may be promising targets for treating AD. F12511 is a high-affinity ACAT1 inhibitor that has passed phase 1 safety tests for antiatherosclerosis. Previously, we developed a nanoparticle system to encapsulate a large concentration of F12511 into a stealth liposome (DSPE-PEG2000 with phosphatidylcholine). Here, we injected the nanoparticle encapsulated F12511 (nanoparticle F) intravenously (IV) in wild-type mice and performed an HPLC/MS/MS analysis and ACAT enzyme activity measurement. The results demonstrated that F12511 was present within the mouse brain after a single IV but did not overaccumulate in the brain or other tissues after repeated IVs. A histological examination showed that F12511 did not cause overt neurological or systemic toxicity. We then showed that a 2-week IV delivery of nanoparticle F to aging 3xTg AD mice ameliorated amyloidopathy, reduced hyperphosphorylated tau and nonphosphorylated tau, and reduced neuroinflammation. This work lays the foundation for nanoparticle F to be used as a possible therapy for AD and other neurodegenerative diseases.

Role of anti-HBs in functional cure of HBeAg+ chronic hepatitis B patients infected with HBV genotype A.

BACKGROUND & AIMS: HBsAg-specific antibody responses are difficult to detect during chronic hepatitis B infection (CHB) and are often overlooked. The aim of this study was to examine whether anti-HBs may be involved in functional cure (FC) by profiling anti-HBs responses in patients with CHB using a panel of specific assays. METHODS: Longitudinal serum samples were obtained from 25 patients with CHB who were infected with HBV genotype A and were undergoing nucleos(t)ide analogue (NA) treatment: 14 achieved FC while 11 remained infected (non-FC). Anti-HBs immune complexes (HBsAg-IC), FcγRIIIa dimer binding, epitope specificity and neutralisation efficacy were measured. RESULTS: HBsAg-IC peaks were detected prior to HBsAg loss in 10/14 FC patients. These HBsAg-IC peaks overlapped with either an alanine aminotransferase (ALT) flare (8/10 patients), or a rise in ALT (2/10 patients). HBsAg-IC peaks were detected in 7/11 non-FC patients, but were not associated with an ALT flare. FCγRIIIa binding was detected in 9/14 FC patients, independent from detection of overlapping HBsAg-IC/ALT peaks. FC patients had stable HBsAg epitope occupancy across the study, whereas non-FC patients had a reduction in HBsAg epitope occupancy within the first 12-24 weeks of NA treatment. Convalescent sera from FC patients recognised more HBsAg epitopes and neutralised HBV infection more potently than anti-HBs derived from vaccinees. Neutralisation potency appeared to increase post-HBsAg loss in 4/5 FC patients examined. CONCLUSIONS: Using these assays, we confirm that anti-HBs responses are present and fluctuate over time in this cohort of patients with HBeAg+ CHB, who were infected with HBV genotype A and treated with NAs. Key anti-HBs profiles associated with either FC or failure to achieve FC were also identified, suggesting a role for anti-HBs responses in FC. LAY SUMMARY: Using a panel of assays to characterise hepatitis B surface antibody (anti-HBs) responses in a group of patients with chronic hepatitis B, we identified anti-HBs profiles associated with either functional cure, or failure to achieve functional cure. Functional cure was associated with immune complex peaks which overlapped with alanine aminotransferase flares. Conversely, in those who did not achieve functional cure, immune complex peaks were present, but were not associated with alanine aminotransferase flares, and a decline in anti-HBs diversity was observed early during treatment.

Cardioinhibitory syncope with asystole during nitroglycerin potentiated head up tilt test: prevalence and clinical predictors.

AIMS: The aim of our study was to evaluate the prevalence and clinical predictors of cardioinhibitory (CI) responses with asystole at the nitroglycerin (NTG)-potentiated head-up tilt test (HUTT) in patients with a history of syncope admitted to a tertiary referral syncope unit. METHODS: We retrospectively evaluated all consecutive patients who underwent NTG-potentiated HUTT for suspected reflex syncope at our institution from March 1 2017 to May 1 2020. The prevalence of HUTT-induced CI syncope was assessed. Univariate and multivariate analyses were performed to test the association of asystolic response to HUTT with a set of clinical covariates. RESULTS: We enrolled 1285 patients (45 ± 19.1 years; 49.6% male); 368 (28.6%) showed HUTT-induced CI response with asystole. A multivariate analysis revealed that the following factors were independently associated with HUTT-induced CI syncope: male sex (OR 1.48; ConInt 1.14-1.92; P = 0.003), smoking (OR 2.22; ConInt 1.56-3.115; P < 0.001), traumatic syncope (OR: 2.81; ConInt 1.79-4.42; P < 0.001), situational syncope (OR 0.45; ConInt 0.27-0.73; P = 0.002), and the use of diuretics (OR 9.94; ConInt 3.83-25.76; P < 0.001). CONCLUSIONS: The cardioinhibitory syncope with asystole induced by NTG-potentiated HUTT is more frequent than previously reported. The male gender, smoking habit, history of traumatic syncope, and use of diuretics were independent predictors of HUTT-induced CI responses. Conversely, the history of situational syncope seems to reduce this probability.

Genome-wide analysis of SARS-CoV-2 strains circulating in Vietnam: Understanding the nature of the epidemic and role of the D614G mutation.

Genome-wide analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains is essential to better understand infectivity and virulence and to track coronavirus disease 2019 (COVID-19) cases and outbreaks. We performed whole-genome sequencing of 27 SARS-CoV-2 strains isolated between January 2020 and April 2020. A total of 54 mutations in different genomic regions was found. The D614G mutation, first detected in March 2020, was identified in 18 strains and was more likely associated with a lower cycle threshold (<25) in real-time reverse-transcription polymerase chain reaction diagnostic tests than the original D614 (prevalence ratio = 2.75; 95% confidence interval, 1.19-6.38). The integration of sequencing and epidemiological data suggests that SARS-CoV-2 transmission in both quarantine areas and in the community in Vietnam occur at the beginning of the epidemic although the country implemented strict quarantine quite early, with strict contact tracing, and testing. These findings provide insights into the nature of the epidemic, as well as shape strategies for COVID-19 prevention and control in Vietnam.

The effect of ASA, ticagrelor, and heparin in ST-segment myocardial infarction patients with prolonged transport times to primary percutaneous intervention.

OBJECTIVES: To investigate the effects of early upstream antithrombotic therapy administration (ATTA) in ST-segment elevation myocardial infarction (STEMI) patients with prolonged transport times to primary percutaneous intervention (PPCI) on major clinical outcomes. BACKGROUND: It remains unclear whether early upstream administration of aspirin, ticagrelor, and unfractionated heparin (UFH) confers additional benefits compared with in-hospital administration. METHODS: Between 2015 and 2018, we performed PPCI in 709 included consecutive STEMI patients. We compared 482 STEMI patients who received aspirin, ticagrelor, and UFH loading in a non-PCI capable spoke hospital before transfer (NPHT) versus 227 prehospital triage setting (PTS) STEMI patients who received in-ambulance aspirin, followed by ticagrelor and UFH in the hub catheterization laboratory. The primary outcome was the presence of a pre-PPCI TIMI flow 2-3 in the infarct related artery (IRA). The secondary outcomes included definite acute stent thrombosis and hemorrhagic complications. RESULTS: The median times from ticagrelor and heparin administration to angiography in the NPHT group and the PTS group were 80.5 min (Interquartile Range (IQR) 68.5-94) and 10 min (IQR 5-15) respectively (p < .0001). Using inverse probability of treatment weighting to minimize heterogeneity between groups, we showed significant differences for the primary outcome (44.6 versus 18.5%, p < .0001) and for definite acute stent thrombosis (0.6 versus 2.6%, p = .03), with no difference in the combined in-hospital BARC 2-5 bleeding events (1.9 versus 3.5%, p = .18) in the NPHT versus the PTS group, respectively. CONCLUSION: In this single-center retrospective cohort study, after adjusting for baseline covariates, early upstream ATTA with aspirin, ticagrelor, and UFH was associated with greater pre-PPCI TIMI flow and less definite acute stent thrombosis in STEMI patients, without increased bleeding risk.

Prediction of heart failure outcomes in patients with type 2 diabetes mellitus: Validation of the Thrombolysis in Myocardial Infarction Risk Score for Heart Failure in Diabetes (TRS-HFDM ) in patients in the ACCORD trial.

AIM: To investigate the ability of the Thrombolysis in Myocardial Infarction Risk Score for Heart Failure in Diabetes (TRS-HFDM ) to stratify patients with type 2 diabetes mellitus (T2DM) and high cardiovascular risk for heart failure (HF) hospitalization. MATERIALS AND METHODS: We used data from the control group of the Action to Control Cardiovascular Risk in Diabetes Study Group (ACCORD) trial (n = 5123; mean follow-up 4.8 years). The TRS-HFDM includes: prior HF (2 points), atrial fibrillation (1 point), coronary artery disease (1 point), estimated glomerular filtration rate <60 mL/min/1.73 m2 (1 point), and urine albumin-to-creatinine ratio (>300 mg/g: 2 points; 30-300 mg/g: 1 point). We evaluated the discrimination (Harrell's C-index) and calibration (Nam-D'Agostino calibration statistic) of the TRS-HFDM with regard to time to HF hospitalization or death due to HF. RESULTS: The mean age of the participants was 62.8 ± 6.6 years, and 38% were women. The prevalences of TRS-HFDM 0, 1, 2, 3 and ≥4 were 42.1%, 34.9%, 14.6%, 6.0% and 2.5%, respectively. Increasing TRS-HFDM corresponded to an increasing HF risk: 1.3 per 1000 person-years for a TRS-HFDM of 0 to 64.7 per 1000 person-years for TRS-HFDM of ≥4. The TRS-HFDM demonstrated robust discrimination of HF outcomes (C-index 0.78). Furthermore, the score was well calibrated for HF outcomes (calibration statistic P = 0.13). Similar results were seen in participants without baseline HF (C-index 0.75). CONCLUSION: The TRS-HFDM discriminates HF-specific risk among people with T2DM. The use of TRS-HFDM to identify those who would maximally benefit from therapies that reduce HF risk warrants evaluation.

The feasibility, reliability, and incremental value of two-dimensional speckle-tracking for the detection of significant coronary stenosis after treadmill stress echocardiography.

BACKGROUND: Two-dimensional speckle-tracking echocardiography (STE) may help detect coronary artery disease (CAD) when combined with dobutamine stress echocardiography. However, few studies have explored STE with exercise stress echocardiography (ESE). We aimed to evaluate the feasibility, reliability, and incremental value of STE combined with treadmill ESE compared to treadmill ESE alone to detect CAD. METHODS: We conducted a case-control study of all consecutive patients with abnormal ESE in 2018-2020 who subsequently underwent coronary angiography within a six-month interval. We 1:1 propensity score-matched these patients to those with a normal ESE. Two blinded operators generated a 17-segment bull's-eye map of longitudinal strain (LS). We utilized the mean differences between stress and baseline LS values in segments 13-17, segment 17, and segments 15-16 to create receiver operator curves for the overall examination, the left anterior descending artery (LAD), and the non-LAD territories, respectively. RESULTS: We excluded 61 STEs from 201 (30.3%) eligible ESEs; 47 (23.4%) because of suboptimal image quality and 14 (7.0%) because of excessive heart rate variability precluding the calculation of a bull's-eye map. After matching, a total of 102 patients were included (51 patients in each group). In the group with abnormal ESE patients (mean age 66.4 years, 39.2% female), 64.7% had significant CAD (> 70% stenosis) at coronary angiogram. In the group with normal ESE patients (mean age 65.1 years, 35.3% female), 3.9% were diagnosed with a new significant coronary stenosis within one year. The intra-class correlation for global LS was 0.87 at rest and 0.92 at stress, and 0.84 at rest, and 0.89 at stress for the apical segments. The diagnostic accuracy of combining ESE and STE was superior to visual assessment alone for the overall examination (area under the curve (AUC) = 0.89 vs. 0.84, p = 0.025), the non-LAD territory (AUC = 0.83 vs. 0.70, p = 0.006), but not the LAD territory (AUC = 0.79 vs. 0.73, p = 0.11). CONCLUSIONS: Two-dimensional speckle-tracking combined with treadmill ESE is relatively feasible, reliable, and may provide incremental diagnostic value for the detection and localization of significant CAD.

Nuclear condensates of the Polycomb protein chromobox 2 (CBX2) assemble through phase separation.

Polycomb group (PcG) proteins repress master regulators of development and differentiation through organization of chromatin structure. Mutation and dysregulation of PcG genes cause developmental defects and cancer. PcG proteins form condensates in the cell nucleus, and these condensates are the physical sites of PcG-targeted gene silencing via formation of facultative heterochromatin. However, the physiochemical principles underlying the formation of PcG condensates remain unknown, and their determination could shed light on how these condensates compact chromatin. Using fluorescence live-cell imaging, we observed that the Polycomb repressive complex 1 (PRC1) protein chromobox 2 (CBX2), a member of the CBX protein family, undergoes phase separation to form condensates and that the CBX2 condensates exhibit liquid-like properties. Using site-directed mutagenesis, we demonstrated that the conserved residues of CBX2 within the intrinsically disordered region (IDR), which is the region for compaction of chromatin in vitro, promote the condensate formation both in vitro and in vivo We showed that the CBX2 condensates concentrate DNA and nucleosomes. Using genetic engineering, we report that trimethylation of Lys-27 at histone H3 (H3K27me3), a marker of heterochromatin formation produced by PRC2, had minimal effects on the CBX2 condensate formation. We further demonstrated that the CBX2 condensate formation does not require CBX2-PRC1 subunits; however, the condensate formation of CBX2-PRC1 subunits depends on CBX2, suggesting a mechanism underlying the assembly of CBX2-PRC1 condensates. In summary, our results reveal that PcG condensates assemble through liquid-liquid phase separation (LLPS) and suggest that phase-separated condensates can organize PcG-bound chromatin.

Clinical features, isolation, and complete genome sequence of severe acute respiratory syndrome coronavirus 2 from the first two patients in Vietnam.

In January 2020, we identified two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients in a familial cluster with one person coming from Wuhan, China. The complete genome sequences of two SARS-CoV-2 strains isolated from these patients were identical and 99.98% similar to strains isolated in Wuhan. This is genetically suggestive of human-to-human transmission of SARS-CoV-2 and indicates Wuhan as the most plausible origin of the early outbreak in Vietnam. The younger patient had a mild upper respiratory illness and a brief viral shedding, whereas the elderly with multi-morbidity had pneumonia, prolonged viral shedding, and residual lung damage. The evidence of nonsynonymous substitutions in the ORF1ab region of the viral sequence warrants further studies.

Incremental prognostic value of echocardiography of left ventricular remodeling and diastolic function in STICH trial.

AIMS: We sought to determine which echocardiographic markers of left ventricular (LV) remodeling and diastolic dysfunction can contribute as incremental and independent prognostic information in addition to current clinical risk markers of ischemic LV systolic dysfunction in the Surgical Treatment for Ischemic Heart Failure (STICH) trial. METHODS AND RESULTS: The cohort consisted of 1511 of 2136 patients in STICH for whom baseline transmitral Doppler (E/A ratio) could be measured by an echocardiographic core laboratory blinded to treatment and outcomes, and prognostic value of echocardiographic variables was determined by a Cox regression model. E/A ratio was the most significant predictor of mortality amongst diastolic variables with lowest mortality for E/A closest 0.8, although mortality was consistently low for E/A 0.6 to 1.0. Mortality increased for E/A < 0.6 and > 1.0 up to approximately 2.3, beyond which there was no further increase in risk. Larger LV end-systolic volume index (LVESVI) and E/A < 0.6 and > 1.0 had incremental negative effects on mortality when added to a clinical multivariable model, where creatinine, LVESVI, age, and E/A ratio accounted for 74% of the prognostic information for predicting risk. LVESVI and E/A ratio were stronger predictors of prognosis than New York Heart Association functional class, anemia, diabetes, history of atrial fibrillation, and stroke. CONCLUSIONS: Echocardiographic markers of advanced LV remodeling and diastolic dysfunction added incremental prognostic value to current clinical risk markers. LVESVI and E/A ratio outperformed other markers and should be considered as standard in assessing risks in ischemic heart failure. E/A closest to 0.8 was the most optimal filling pattern.