ABSTRACT
Importance: Abnormal blood pressure pattern is an independent risk factor for vascular events. Blood pressure variability can predict cardiovascular and cerebrovascular disease outcomes and is closely associated with the risk of cognitive impairment. However, the relationship between blood pressure variability and cerebral small vessel disease neuroimaging markers remains unclear. This study aimed to evaluate the relationship between blood pressure variability and cerebral small vessel disease neuroimaging markers. Data sources: We searched multiple databases, including Embase, Web of Science, PubMed, Cochrane Library, UpToDate, and World of Science, from their inception until November 27, 2023.Main Outcomes and Measures: A meta-analysis of 19 observational studies involving 14519 participants was performed. Findings: â Systolic blood pressure variability was correlated with the cerebral small vessel disease total burden, white matter hyperintensities and lacunar infarction; â¡ Diastolic blood pressure variability was correlated with the cerebral small vessel disease total burden, white matter hyperintensities and cerebral microbleeds; ⢠Non-dipping patterns were correlated with white matter hyperintensities and lacunar infarction. ⣠Reverse-dipping patterns were significantly correlated with white matter hyperintensities and cerebral microbleeds. Conclusions: and Relevance: Blood pressure variability correlates with neuroimaging markers of cerebral small vessel disease and its burden. Hence, early monitoring and intervention of blood pressure variability may be essential for the early diagnosis, prevention and treatment of cerebral small vessel disease.
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Mitochondria have diverse functions critical to whole-body metabolic homeostasis. Endurance training alters mitochondrial activity, but systematic characterization of these adaptations is lacking. Here, the Molecular Transducers of Physical Activity Consortium mapped the temporal, multi-omic changes in mitochondrial analytes across 19 tissues in male and female rats trained for 1, 2, 4, or 8 weeks. Training elicited substantial changes in the adrenal gland, brown adipose, colon, heart, and skeletal muscle. The colon showed non-linear response dynamics, whereas mitochondrial pathways were downregulated in brown adipose and adrenal tissues. Protein acetylation increased in the liver, with a shift in lipid metabolism, whereas oxidative proteins increased in striated muscles. Exercise-upregulated networks were downregulated in human diabetes and cirrhosis. Knockdown of the central network protein 17-beta-hydroxysteroid dehydrogenase 10 (HSD17B10) elevated oxygen consumption, indicative of metabolic stress. We provide a multi-omic, multi-tissue, temporal atlas of the mitochondrial response to exercise training and identify candidates linked to mitochondrial dysfunction.
Subject(s)
Mitochondria , Physical Conditioning, Animal , Animals , Male , Female , Mitochondria/metabolism , Rats , Muscle, Skeletal/metabolism , Humans , Rats, Sprague-Dawley , Adipose Tissue, Brown/metabolism , Adrenal Glands/metabolism , MultiomicsABSTRACT
Regular exercise has many physical and brain health benefits, yet the molecular mechanisms mediating exercise effects across tissues remain poorly understood. Here we analyzed 400 high-quality DNA methylation, ATAC-seq, and RNA-seq datasets from eight tissues from control and endurance exercise-trained (EET) rats. Integration of baseline datasets mapped the gene location dependence of epigenetic control features and identified differing regulatory landscapes in each tissue. The transcriptional responses to 8 weeks of EET showed little overlap across tissues and predominantly comprised tissue-type enriched genes. We identified sex differences in the transcriptomic and epigenomic changes induced by EET. However, the sex-biased gene responses were linked to shared signaling pathways. We found that many G protein-coupled receptor-encoding genes are regulated by EET, suggesting a role for these receptors in mediating the molecular adaptations to training across tissues. Our findings provide new insights into the mechanisms underlying EET-induced health benefits across organs.
Subject(s)
Physical Conditioning, Animal , Transcriptome , Animals , Physical Conditioning, Animal/physiology , Male , Rats , Female , DNA Methylation , Epigenesis, Genetic , Epigenomics , Adaptation, Physiological/genetics , Organ Specificity , Rats, Sprague-DawleyABSTRACT
Neurons regulate the microtubule-based transport of certain vesicles selectively into axons or dendrites to ensure proper polarization of function. The mechanism of this polarized vesicle transport is still not fully elucidated, though it is known to involve kinesins, which drive anterograde transport on microtubules. Here, we explore how the kinesin-3 family member KIF13A is regulated such that vesicles containing transferrin receptor (TfR) travel only to dendrites. In experiments involving live-cell imaging, knockout of KIF13A, BioID assay, we found that the kinase MARK2 phosphorylates KIF13A at a 14-3-3 binding motif, strengthening interaction of KIF13A with 14-3-3 such that it dissociates from TfR-containing vesicles, which therefore cannot enter axons. Overexpression of KIF13A or knockout of MARK2 leads to axonal transport of TfR-containing vesicles. These results suggest a unique kinesin-based mechanism for polarized transport of vesicles to dendrites.
Subject(s)
14-3-3 Proteins , Dendrites , Kinesins , Protein Serine-Threonine Kinases , Receptors, Transferrin , Kinesins/metabolism , Kinesins/genetics , 14-3-3 Proteins/metabolism , Dendrites/metabolism , Phosphorylation , Receptors, Transferrin/metabolism , Animals , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Humans , Binding Sites , Microtubules/metabolism , Rats , Mice , Protein BindingABSTRACT
Objective: To evaluate intracerebral hemorrhage (ICH) risk in patients with ischemic stroke (IS) and cerebral microbleeds (CMBs) undergoing anticoagulation therapy for non-valvular atrial fibrillation (AF). Methods: We conducted a comprehensive search across multiple databases, including Embase, PubMed, Cochrane, UpToDate, Scopus, WOS, and SinoMed. The search covered observational literature published from each database inception until February 1, 2023. We analyzed the prevalence of CMBs during the follow-up period, compared future ICH risk between patients with and without baseline CMBs (CMBs presence/absence, â§5 CMBs), and examined factors influencing ICH occurrence in patients with CMBs. Also studied recurrent stroke during anticoagulation therapy, the risk of future ICH when white matter hyperintensity (WMH) and CMBs coexist, and the effects of anticoagulants vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) on future ICH. Results: We included 7 articles involving 5,134 participants. The incidence of CMBs was 24%; baseline CMBs were associated with an increased ICH risk compared to patients without CMBs. ICH-risk was more significant in patients with baseline ≥5 CMBs. After anticoagulant therapy, ICH risk was higher than that of recurrent IS. The risk of future ICH was significantly increased with anticoagulant VKAs compared with NOAC. Conclusion: Anticoagulant therapy for ischemic stroke patients with non-valvular AF and CMBs increases future ICH risk. Discontinuing anticoagulation due to ICH risk should be avoided. NOACs are safe and effective for patients with CMBs and IS.
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BACKGROUND: Papillary thyroid cancer (PTC) is an indolent disease with a favorable prognosis but characterized by a high recurrence rate. We aimed to improve precise stratification of recurrence risk in PTC patients with early stage using multi-gene signatures. PATIENTS AND METHODS: The present study was performed using data from The Cancer Genome Atlas (TCGA) and multi-center datasets. Unsupervised consensus clustering was used to obtain the optimal molecular subtypes and least absolute shrinkage and selection operator (LASSO) analysis was performed to identify potential genes for the construction of recurrence signature. Kaplan-Meier survival analysis and the log-rank test was used to detect survival differences. Harrells concordance index (C-index) was used to assess the performance of the DNA damage repair (DDR) recurrence signature. RESULTS: Through screening 8 candidate gene sets, the entire cohort was successfully stratified into two recurrence-related molecular subtypes based on DDR genes: DDR-high subtype and DDR-low subtype. The recurrence rate of DDR-high subtype was significantly lower than DDR-low subtype [HR = 0.288 (95%CI, 0.084-0.986), P = 0.047]. Further, a two-gene DDR recurrence signature was constructed, including PER1 and EME2. The high-risk group showed a significantly worse recurrence-free survival (RFS) than the low-risk group [HR = 10.647 (95%CI, 1.363-83.197), P = 0.024]. The multi-center data demonstrated that proportion of patients with low expression of PER1 and EME2 was higher in the recurrence group than those in the non-recurrence group. CONCLUSIONS: These findings could help accurately and reliably identify PTC patients with high risk of recurrence so that they could receive more radical and aggressive treatment strategies and more rigorous surveillance practices.
ABSTRACT
BACKGROUND: A history of SARS-CoV-2 infection has been reported to be associated with an increased risk of postoperative pulmonary complications (PPCs). Even mild PPCs can elevate the rates of early postoperative mortality, intensive care unit (ICU) admission and prolong the length of ICU and/or hospital stays. Consequently, it is crucial to develop perioperative management strategies that can mitigate these increased risks in surgical patients who have recently been infected with SARS-CoV-2. Accumulating evidence suggests that nitric oxide (NO) inhalation might be effective in treating COVID-19. NO functions in COVID-19 by promoting vasodilation, anticoagulation, anti-inflammatory and antiviral effects. Therefore, our study hypothesises that the perioperative use of NO can effectively reduce PPCs in patients with recent SARS-CoV-2 infection. METHOD AND ANALYSIS: A prospective, double-blind, single-centre, randomised controlled trial is proposed. The trial aims to include participants who are planning to undergo surgery with general anaesthesia and have been recently infected with SARS-CoV-2 (within 7 weeks). Stratified allocation of eligible patients will be performed at a 1:1 ratio based on the predicted risk of PPCs using the Assess Respiratory Risk in Surgical Patients in Catalonia risk index and the time interval between infection and surgery.The primary outcome of the study will be the presence of PPCs within the first 7 days following surgery, including respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, bronchospasm and aspiration pneumonitis. The primary outcome will be reported as counts (percentage) and will be compared using a two-proportion χ2 test. The common effect across all primary components will be estimated using a multiple generalised linear model. ETHICS AND DISSEMINATION: The trial is approved by the Institutional Review Board of Xijing Hospital (KY20232058-F1). The findings, including positive, negative and inconclusive results, will be published in scientific journals with peer-review processes. TRIAL REGISTRATION NUMBER: NCT05721144.
Subject(s)
COVID-19 , Humans , Nitric Oxide/therapeutic use , Postoperative Complications/prevention & control , Prospective Studies , Randomized Controlled Trials as Topic , SARS-CoV-2 , Treatment OutcomeABSTRACT
BACKGROUND: Trousseau syndrome (TS) is relatively rare and easily overlooked by clinicians, causing misdiagnosis and affecting subsequent treatment. OBJECTIVE: In this study, clinical features, laboratory examination, imaging features, treatment, and prognosis of patients with TS were discussed. METHODS AND MATERIAL: From February 2018 to April 2022, cases of 21 patients with malignant tumors complicated by acute ischemic stroke (AIS) were admitted to the Neurology Department of the hospital, and were retrospectively analyzed and discussed based on the literature. RESULTS: Twenty-one cases were included in the study. Of these, 95.23% (20/21) developed AIS 6-21 months after the onset of malignant tumors, 9.52% (2/21) had ischemic stroke as the first symptom, 4.76% (1/21) had recurrent ischemic stroke, and 14.29% (3/21) subsequently experienced venous and arterial thrombosis events; 80.95% (17/21) were pathologically confirmed to have adenocarcinoma; and 90.47% (19/21) of infarction cases involved multiple blood vessel feeding sites. MRI showed multiregional, multifocal patchy infarcts. D-dimer concentration was higher than normal in all patients. In addition, 61.90% (13/21) of the patients had poor outcomes according to mRS. CONCLUSION: TS is a rare clinical type. It is often associated with adenocarcinoma, and the treatment is different from that of conventional cerebral infarction and the prognosis is very poor. In clinical practice, for AIS of unknown cause, if MRI shows multiple small lesions accompanied by a significant increase in D-dimer, routine screening for latent malignant tumors is recommended.
Subject(s)
Adenocarcinoma , Ischemic Stroke , Stroke , Humans , Adenocarcinoma/complications , Cerebral Infarction/complications , Ischemic Stroke/complications , Prognosis , Retrospective Studies , Stroke/complications , Stroke/diagnostic imagingABSTRACT
Neurons regulate the microtubule-based transport of certain vesicles selectively into axons or dendrites to ensure proper polarization of function. The mechanism of this polarized vesicle transport is still not fully elucidated, though it is known to involve kinesins, which drive anterograde transport on microtubules. Here we explore how the kinesin-3 family member KIF13A is regulated such that vesicles containing transferrin receptor (TfR) travel only to dendrites. In experiments involving live-cell imaging, knockout of KIF13A, BioID assay, we found that the kinase MARK2 phosphorylates KIF13A at a 14-3-3 binding motif, strengthening interaction of KIF13A with 14-3-3 such that it dissociates from TfR-containing vesicles, which therefore cannot enter axons. Overexpression of KIF13A or knockout of MARK2 leads to axonal transport of TfR-containing vesicles. These results suggest a novel kinesin-based mechanism for polarized transport of vesicles to dendrites. Significance: Our findings suggest that at least one type of vesicles, those containing transferrin receptor, travel exclusively to dendrites and are excluded from axons because the kinase MARK2 phosphorylates the kinesin KIF13A to promote its separation from vesicles at the proximal axon, preventing vesicle transport into axons, such that they travel only to dendrites. Future studies should explore how this mechanism of polarized vesicle transport supports neuronal function.
ABSTRACT
Endowing room-temperature polymorphs with both long-term stability and easy interconvertibility is a big challenge due to the complexity of intermolecular interactions. Herein, we present a chiral hexagonal perovskite (R-3-hydroxy-1-methylpiperidinium)[CdCl3 ] having two room-temperature crystalline forms featuring obviously distinct second-harmonic-generation (SHG) signals with a high switching contrast of ~18â times. The two room-temperature forms could be long-term stable yet easily interconvertible through an irreversible thermal-induced phase transition and a pressure-driven backward transition, by switching hydrogen bonds via collective reorientation of ordered homochiral cations. Based on the essential role of homochiral organic cations in inducing switchable hydrogen bond linkages, this present instance provides good evidence that relatively irregular organic cations could induce more obvious inorganic chain deformations, thus endowing polymorphs with significantly different SHG signals at room temperature.
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OBJECTIVE: This study aimed to investigate the effects of intensive blood pressure control on cognitive function in elderly patients with cerebral small vessel disease (CSVD). METHODS: From May 2020 to June 2022, 140 outpatients and inpatients with CSVD and hypertension in the Department of Neurology of Beijing Shijingshan Hospital were selected. They were randomly divided into the standard and intensive blood pressure control groups, and the dosage of antihypertensive drugs was adjusted to reduce the blood pressure to the target level. The patients were followed up for 2 years. The medical records or data at "enrollment" and "2-year follow-up" were analyzed and evaluated. The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to evaluate cognitive function. Cranial magnetic resonance imaging was performed to evaluate lacunar infarctions (LIs) and white matter hyperintensity (WMH). Multiple linear regression was used to analyze the correlation between MMSE scores and blood pressure, WMH, and LIs. RESULTS: (1) The MMSE and MoCA scores in the standard group were significantly lower than those at enrollment. The WMH score in the standard group was significantly higher than that at enrollment. (2) After the 2-year follow-up, the 24-h systolic blood pressure (SBP), 24-h diastolic blood pressure (DBP), daytime mean SBP, daytime mean DBP, and nighttime mean SBP in the two groups significantly decreased, which had significant statistical significance (P < 0.05). (3) The correlation between blood pressure and MMSE score was analyzed using multiple linear regression analysis. The WMH score, LIs, 24-h SBP, and 24-h DBP were independently correlated with MMSE scores. CONCLUSION: In elderly patients with hypertension, a decrease in SBP to 126 mmHg, compared with 134 mmHg, can delay cognitive impairment as well as reduce LIs and cerebral WMH lesions in patients with CSVD.
Subject(s)
Cerebral Small Vessel Diseases , Cognitive Dysfunction , Hypertension , Stroke, Lacunar , Humans , Aged , Blood Pressure/physiology , Cognition , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/drug therapy , Cerebral Small Vessel Diseases/complications , Cerebral Small Vessel Diseases/diagnostic imaging , Cerebral Small Vessel Diseases/drug therapy , Hypertension/complications , Hypertension/diagnosis , Hypertension/drug therapyABSTRACT
Hybrid ferroelastics have attracted increasing attention for their potential application as mechanical switches. The sporadically documented anomalous ferroelastic phase transitions, i.e., ferroelasticity that appears at a high-temperature phase rather than a low-temperature phase, are of particular interest but are not well understood at the molecular level. By judiciously choosing a polar and flexible organic cation (Me2NH(CH2)2Br+) with cis-/anti- conformations as an A-site component, we obtained two new polar hybrid ferroelastics, A2[MBr6] (M = Te for 1 and Sn for 2). These materials undergo distinct thermal-induced ferroelastic phase transitions. The larger [TeBr6]2- anions anchor the adjacent organic cations well and essentially endow 1 with a conventional ferroelastic transition (P21 â Pm21n) arising from a common order-disorder transition of organic cations without conformational changes. Moreover, the smaller [SnBr6]2- anions can interact with the adjacent organic cations in energetically similar sets of intermolecular interactions, enabling 2 to undergo an anomalous ferroelastic phase transition (P212121 â P21) arising from an unusual cis-/anti-conformational reversal of organic cations. These two instances demonstrate the importance of the delicate balance of intermolecular interactions for inducing anomalous ferroelastic phase transitions. The findings here provide important insights for seeking new multifunctional ferroelastic materials.
ABSTRACT
BACKGROUND: Interstitial lung disease (ILD) is a common pulmonary manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). OBJECTIVES: We aimed to clarify the clinical predictors of mortality in a cohort of patients with AAV-related ILD (AAV-ILD). METHOD: We retrospectively identified AAV-ILD patients seen at Peking University First Hospital from January 2010 to June 2020 and manually screened for study inclusion. Baseline computed tomography (CT) images were further classified as nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), and unclassified ILD. Disease characteristics and other pulmonary findings including pulmonary function test and bronchoalveolar lavage (BAL) were also evaluated. Multivariable Cox regression analysis was performed to identify clinical predictors of mortality. RESULTS: The cohort included 204 patients with AAV-ILD, 152 had UIP on CT (AAV-UIP), 39 had NSIP on CT (AAV-NSIP), 3 had OP, and 10 had unclassified ILD. Microscopic polyangiitis was more prevalent in patients with UIP, while granulomatosis with polyangiitis was more common in the NSIP and OP groups, and eosinophilic granulomatosis with polyangiitis was more frequent in patients with unclassified ILD. ILD diagnosis before AAV was more common in patients with either UIP or NSIP patterns. During the median follow-up of 40 months, 44 (21.6%) patients died. One- and 5-year overall survival rates were 88.2% (95% CI, 83.7-92.7%) and 81.0% (95% CI, 74.9-87.1%) for the entire cohort. Patients with UIP patterns had the worst prognosis, while those with NSIP patterns had the best long-term outcome. Specifically, patients with UIP patterns had an approximately 5-fold risk of death compared to those with NSIP. After controlling for potential confounding factors, we observed that each 10% increase in the BAL fluid neutrophil percentage was associated with nearly a 20% increased risk of death (HR 1.195, 95% CI 1.018-1.404). CONCLUSIONS: Clinical characteristics and survival differ between subgroups defined by CT patterns. BAL fluid neutrophilia is an independent predictor of mortality among AAV-ILD patients, and therefore, the clinical utility of BAL at the time of AAV diagnosis should be considered.
Subject(s)
Churg-Strauss Syndrome , Granulomatosis with Polyangiitis , Idiopathic Interstitial Pneumonias , Idiopathic Pulmonary Fibrosis , Lung Diseases, Interstitial , Humans , Antibodies, Antineutrophil Cytoplasmic , Retrospective Studies , Churg-Strauss Syndrome/complications , Lung Diseases, Interstitial/diagnosis , Idiopathic Pulmonary Fibrosis/complications , Idiopathic Interstitial Pneumonias/complications , PrognosisABSTRACT
Transcription factors (TFs) play a key role in regulating gene expression and responses to stimuli. We conducted an integrated analysis of chromatin accessibility, DNA methylation, and RNA expression across eight rat tissues following endurance exercise training (EET) to map epigenomic changes to transcriptional changes and determine key TFs involved. We uncovered tissue-specific changes and TF motif enrichment across all omic layers, differentially accessible regions (DARs), differentially methylated regions (DMRs), and differentially expressed genes (DEGs). We discovered distinct routes of EET-induced regulation through either epigenomic alterations providing better access for TFs to affect target genes, or via changes in TF expression or activity enabling target gene response. We identified TF motifs enriched among correlated epigenomic and transcriptomic alterations, DEGs correlated with exercise-related phenotypic changes, and EET-induced activity changes of TFs enriched for DEGs among their gene targets. This analysis elucidates the unique transcriptional regulatory mechanisms mediating diverse organ effects of EET.
ABSTRACT
Mitochondria are adaptable organelles with diverse cellular functions critical to whole-body metabolic homeostasis. While chronic endurance exercise training is known to alter mitochondrial activity, these adaptations have not yet been systematically characterized. Here, the Molecular Transducers of Physical Activity Consortium (MoTrPAC) mapped the longitudinal, multi-omic changes in mitochondrial analytes across 19 tissues in male and female rats endurance trained for 1, 2, 4 or 8 weeks. Training elicited substantial changes in the adrenal gland, brown adipose, colon, heart and skeletal muscle, while we detected mild responses in the brain, lung, small intestine and testes. The colon response was characterized by non-linear dynamics that resulted in upregulation of mitochondrial function that was more prominent in females. Brown adipose and adrenal tissues were characterized by substantial downregulation of mitochondrial pathways. Training induced a previously unrecognized robust upregulation of mitochondrial protein abundance and acetylation in the liver, and a concomitant shift in lipid metabolism. The striated muscles demonstrated a highly coordinated response to increase oxidative capacity, with the majority of changes occurring in protein abundance and post-translational modifications. We identified exercise upregulated networks that are downregulated in human type 2 diabetes and liver cirrhosis. In both cases HSD17B10, a central dehydrogenase in multiple metabolic pathways and mitochondrial tRNA maturation, was the main hub. In summary, we provide a multi-omic, cross-tissue atlas of the mitochondrial response to training and identify candidates for prevention of disease-associated mitochondrial dysfunction.
ABSTRACT
The accurate evaluation of the carcinogenic risk of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) is crucial because of the teratogenic, carcinogenic, and mutagenic effects of PAHs. The best model out of six models was selected across three highly used categories in recent years, including the USEPA-recommended inhalation risk (Model I), inhalation carcinogen unit risk (Models IIA-IID), and three exposure pathways (inhalation, dermal, and oral) (Model III). Model I was found to be superior to the other models, and its predicted risk values were in accordance with the thresholds of PM2.5 and benzo[a]pyrene in ambient-air-quality standards. Models IIA and III overestimated the risk of cancer compared to the actual cancer incidence in the local population. Model IID can replace Models IIB and IIC as these models exhibited no statistically significant differences between each other. Furthermore, the exposure parameters were optimized for Model I and significant differences were observed with respect to country and age. However, the gender difference was not statistically significant. In conclusion, Model I is recommended as the more suitable model, but in assessing cancer risk in the future, the exposure parameters must be appropriate for each country.
ABSTRACT
Molecular-based ferroic phase-transition materials have attracted increasing attention in the past decades due to their promising potential as sensors, switches, and memory. One of the long-term challenges in the development of molecular-based ferroic materials is determining how to promote the ferroic phase-transition temperature (T c). Herein, we present two new hexagonal molecular perovskites, (nortropinonium)[CdCl3] (1) and (nortropinium)[CdCl3] (2), to demonstrate a simple design principle for obtaining ultrahigh-T c ferroelastic phase transitions. They consist of same host inorganic chains but subtly different guest organic cations featuring a rigid carbonyl and a flexible hydroxyl group in 1 and 2, respectively. With stronger hydrogen bonds involving the carbonyl but a relatively lower decomposition temperature (T d, 480 K), 1 does not exhibit a crystalline phase transition before its decomposition. The hydroxyl group subtly changes the balance of intermolecular interactions in 2via reducing the attractive hydrogen bonds but increasing the repulsive interactions between adjacent organic cations, which finally endows 2 with an enhanced thermal stability (T d = 570 K) and three structural phase transitions, including two ferroelastic phase transitions at ultrahigh T c values of 463 K and 495 K, respectively. This finding provides important clues to judiciously tuning the intermolecular interactions in hybrid crystals for developing high-T c ferroic materials.
ABSTRACT
Crosslinking mass spectrometry (XL-MS) of bacterial ribosomes revealed the dynamic intra- and intermolecular interactions within the ribosome structure. It has been also extended to capture the interactions of ribosome binding proteins during translation. Generally, XL-MS often identified the crosslinks within a cross-linkable distance (<40 Å) using amine-reactive crosslinkers. The crosslinks larger than cross-linkable distance (>40 Å) are always difficult to interpret and remain unnoticed. Here, we focused on stationary phase bacterial ribosome crosslinking that yields ultra-long crosslinks in an E. coli cell lysate. We explain these ultra-long crosslinks with the combination of sucrose density gradient centrifugation, chemical crosslinking, high-resolution mass spectrometry, and electron microscopy analysis. Multiple ultra-long crosslinks were observed in E. coli ribosomes for example ribosomal protein L19 (K63, K94) crosslinks with L21 (K71, K81) at two locations that are about 100 Å apart. Structural mapping of such ultra-long crosslinks in 70S ribosomes suggested that these crosslinks are not potentially formed within one 70S particle and could be a result of dimer and trimer formation as evidenced by negative staining electron microscopy. Ribosome dimerization captured by chemical crosslinking reaction could be an indication of ribosome-ribosome interactions in the stationary phase.
ABSTRACT
To optimize the effect-directed analysis (EDA) approach to identify the fine particulate matter (PM2.5) bound organic toxicants, Jinzhong city, in the Shanxi Province of China, was selected as the object of our study. First, PM2.5 samples were collected and their organic extracts were separated out in 9 fractions (F1-F9) using reversed-phase high performance liquid chromatography after purification using gel permeation chromatography. Second, the toxicity effects of each fraction were measured by human bronchial epithelial cells (BEAS-2B) in vitro. And toxicity effects included antioxidant stress (ROS, LDH, and CAT) and an inflammatory response (IL-6, IL-1ß, and TNF-α). The results showed that the scores of the toxicity effects on multiple lines of evidence were the highest in the F3 and F4 fractions compared with those of the control. Subsequently, the main poisons, o-cymene, p-cymene, benzene, ethylbenzene, xylene, and styrene, were identified using GC×GC-TOF/MS. Finally, to confirm the above possible candidates, (1) the levels of o-cymene, p-cymene and BTEXS in daily PM2.5 were measured using GC-MS in November 2020, and the rates of detection of these pollutants were 100% in PM2.5. Among them, o-cymene and p-cymene were first reported as the key toxic substances of PM2.5, and their average concentration values were 0.16 ± 0.11 and 0.18 ± 0.15 ngâ§m-3, respectively. (2) the toxicity of p-cymene may be no less than that of other benzene derivatives according to their LC50 in Daphnia magna. (3) based on canonical correlation analysis, the exposure to p-cymene, benzene, and styrene in PM2.5 was most likely associated with the toxicity effects (CAT, IL-6, and TNF-α), which in turn caused the observed toxicity. In conclusion, p-cymene, benzene, and styrene were found to be the key toxic organics in PM2.5 for cells in vitro. EDA technology avoids the limitations of chemical analysis and uncertainty of the biological testing and adds new toxicants to the control list of PM2.5, contributing to this study field. However, the application of EDA to PM2.5 still faces challenges such as the selection of biological effects, loss of toxicity with the separation process, influence of the dosing method, and identification of the unknown effects of pollutants.
Subject(s)
Air Pollutants , Air Pollutants/analysis , Air Pollutants/toxicity , Benzene/analysis , Biological Assay , China , Cymenes , Hazardous Substances/analysis , Interleukin-6 , Particulate Matter/analysis , Particulate Matter/toxicity , Styrenes/analysis , Tumor Necrosis Factor-alphaABSTRACT
While it is established that the functional impact of genetic variation can vary across cell types and states, capturing this diversity remains challenging. Current studies using bulk sequencing either ignore this heterogeneity or use sorted cell populations, reducing discovery and explanatory power. Here, we develop scDALI, a versatile computational framework that integrates information on cellular states with allelic quantifications of single-cell sequencing data to characterize cell-state-specific genetic effects. We apply scDALI to scATAC-seq profiles from developing F1 Drosophila embryos and scRNA-seq from differentiating human iPSCs, uncovering heterogeneous genetic effects in specific lineages, developmental stages, or cell types.