Systems Biology

Design, Dimerization, and Recombinant Production of MCh-AMP1-Derived Peptide in <em>Escherichia coli</em> and Evaluation of Its Antifungal Activity and Cytotoxicity

Mon, 2023-09-25 06:00

Front Fungal Biol. 2021 Apr 26;2:638595. doi: 10.3389/ffunb.2021.638595. eCollection 2021.

ABSTRACT

Fungal species resistant to current antifungal agents are considered as a serious threat to human health, the dilemma that has dragged attentions toward other sources of antifungals such as antimicrobial peptides (AMPs). In order to improve biological activity of a recently described antifungal peptide MCh-AMP1 from Matricaria chamomilla flowers, MCh-AMP1dimer (DiMCh-AMP1), containing 61 amino acid residues connected by flexible linker (GPDGSGPDESGPDES), was designed and expressed in Escherichia coli, and its structure was analyzed using bioinformatics tools. DiMCh-AMP1 synthetic gene was cloned into pET-28a expression vector, which was then used to transform E. coli BL21 (DE3) strain. His-tag purification was achieved using metal-chelate affinity chromatography. Because there is no methionine residue in the DiMCh-AMP1 sequence, cyanogen bromide was successfully used to separate the target product from the tag. Reverse-phase high-performance liquid chromatography was used as the final step of purification. Results showed that recombinant peptide was produced in considerable amounts (0.9 mg/L) with improved antifungal activity toward both yeasts and molds compared to its monomeric counterpart. The minimum inhibition concentration and minimum fungicidal concentration values of DiMCh-AMP1 against Candida and Aspergillus species were reported in the range of 1.67-6.66 μM and 3.33-26.64 μM, respectively. Our results showed that while antifungal activity of dimerized peptide was improved considerably, its cytotoxicity was decreased, implying that DiMCh-AMP1 could be a potential candidate to design an effective antifungal agent against pathogenic yeasts and molds.

PMID:37744143 | PMC:PMC10512307 | DOI:10.3389/ffunb.2021.638595

Categories: Literature Watch

Grand Challenges in Fungal Biotechnology

Mon, 2023-09-25 06:00

Front Fungal Biol. 2020 Dec 8;1:626551. doi: 10.3389/ffunb.2020.626551. eCollection 2020.

NO ABSTRACT

PMID:37743876 | PMC:PMC10512378 | DOI:10.3389/ffunb.2020.626551

Categories: Literature Watch

GH3-mediated auxin inactivation attenuates multiple stages of lateral root development

Mon, 2023-09-25 06:00

New Phytol. 2023 Sep 25. doi: 10.1111/nph.19284. Online ahead of print.

ABSTRACT

Lateral root (LR) positioning and development rely on the dynamic interplay between auxin production, transport but also inactivation. Nonetheless, how the latter affects LR organogenesis remains largely uninvestigated. Here, we systematically analyze the impact of the major auxin inactivation pathway defined by GRETCHEN HAGEN3-type (GH3) auxin conjugating enzymes and DIOXYGENASE FOR AUXIN OXIDATION1 (DAO1) in all stages of LR development using reporters, genetics and inhibitors in Arabidopsis thaliana. Our data demonstrate that the gh3.1/2/3/4/5/6 hextuple (gh3hex) mutants display a higher LR density due to increased LR initiation and faster LR developmental progression, acting epistatically over dao1-1. Grafting and local inhibitor applications reveal that root and shoot GH3 activities control LR formation. The faster LR development in gh3hex is associated with GH3 expression domains in and around developing LRs. The increase in LR initiation is associated with accelerated auxin response oscillations coinciding with increases in apical meristem size and LR cap cell death rates. Our research reveals how GH3-mediated auxin inactivation attenuates LR development. Local GH3 expression in LR primordia attenuates development and emergence, whereas GH3 effects on pre-initiation stages are indirect, by modulating meristem activities that in turn coordinate root growth with LR spacing.

PMID:37743759 | DOI:10.1111/nph.19284

Categories: Literature Watch

Non-small Cell Lung Cancer Epigenomes Exhibit Altered DNA Methylation in Smokers and Never-smokers

Sun, 2023-09-24 06:00

Genomics Proteomics Bioinformatics. 2023 Sep 22:S1672-0229(23)00105-5. doi: 10.1016/j.gpb.2023.03.006. Online ahead of print.

ABSTRACT

Epigenetic alterations are widespread in cancer and can complement genetic alterations to influence cancer progression and treatment outcome. To determine the potential contribution of DNA methylation alterations to tumor phenotype in non-small cell lung cancer (NSCLC) in both smoker and never-smoker patients, we performed genome-wide profiling of DNA methylation in 17 primary NSCLC tumors and 10 matched normal lung samples using the complementary assays methylation DNA immunoprecipitation (MeDIP-seq) and methylation sensitive restriction enzyme digestion followed by sequencing (MRE-seq). We reported recurrent methylation changes of several gene promoters, many previously implicated in cancer, including FAM83A and SEPT9 (hypomethylation), as well as PCDH7, NKX2-1, and SOX17 (hypermethylation). Although many methylation changes between tumors and their paired normal samples were shared across patients, several were specific to a particular smoking status. For example, never-smokers displayed a greater proportion of hypomethylated differentially methylated regions (hypoDMRs) and a greater number of recurrently hypomethylated promoters, including those of ASPSCR1, TOP2A, DPP9, and USP39, all previously linked to cancer. Changes outside of promoters were also widespread and often recurrent, particularly methylation loss over repetitive elements, highly enriched for ERV1 subfamilies. Recurrent hypoDMRs were enriched for several transcription factor binding motifs, often for genes involved in signaling and cell proliferation. For example, 71% of recurrent promoter hypoDMRs contained a motif for NKX2-1. Finally, the majority of DMRs were located within an active chromatin state in tissues profiled using the Roadmap Epigenome data, suggesting that methylation changes may contribute to altered regulatory programs through the adaptation of cell type-specific expression programs.

PMID:37742993 | DOI:10.1016/j.gpb.2023.03.006

Categories: Literature Watch

Impact of Eating a Carbohydrate-Restricted Diet on Cortical Atrophy in a Cross-Section of Amyloid Positive Patients with Alzheimer's Disease: A Small Sample Study

Sun, 2023-09-24 06:00

J Alzheimers Dis. 2023 Sep 22. doi: 10.3233/JAD-230458. Online ahead of print.

ABSTRACT

BACKGROUND: A carbohydrate-restricted diet aimed at lowering insulin levels has the potential to slow Alzheimer's disease (AD). Restricting carbohydrate consumption reduces insulin resistance, which could improve glucose uptake and neural health. A hallmark feature of AD is widespread cortical thinning; however, no study has demonstrated that lower net carbohydrate (nCHO) intake is linked to attenuated cortical atrophy in patients with AD and confirmed amyloidosis.

OBJECTIVE: We tested the hypothesis that individuals with AD and confirmed amyloid burden eating a carbohydrate-restricted diet have thicker cortex than those eating a moderate-to-high carbohydrate diet.

METHODS: A total of 31 patients (mean age 71.4±7.0 years) with AD and confirmed amyloid burden were divided into two groups based on a 130 g/day nCHO cutoff. Cortical thickness was estimated from T1-weighted MRI using FreeSurfer. Cortical surface analyses were corrected for multiple comparisons using cluster-wise probability. We assessed group differences using a two-tailed two-independent sample t-test. Linear regression analyses using nCHO as a continuous variable, accounting for confounders, were also conducted.

RESULTS: The lower nCHO group had significantly thicker cortex within somatomotor and visual networks. Linear regression analysis revealed that lower nCHO intake levels had a significant association with cortical thickness within the frontoparietal, cingulo-opercular, and visual networks.

CONCLUSIONS: Restricting carbohydrates may be associated with reduced atrophy in patients with AD. Lowering nCHO to under 130 g/day would allow patients to follow the well-validated MIND diet while benefiting from lower insulin levels.

PMID:37742646 | DOI:10.3233/JAD-230458

Categories: Literature Watch

The effect of polyphenols on DNA methylation-assessed biological age attenuation: the DIRECT PLUS randomized controlled trial

Sun, 2023-09-24 06:00

BMC Med. 2023 Sep 25;21(1):364. doi: 10.1186/s12916-023-03067-3.

ABSTRACT

BACKGROUND: Epigenetic age is an estimator of biological age based on DNA methylation; its discrepancy from chronologic age warrants further investigation. We recently reported that greater polyphenol intake benefitted ectopic fats, brain function, and gut microbiota profile, corresponding with elevated urine polyphenols. The effect of polyphenol-rich dietary interventions on biological aging is yet to be determined.

METHODS: We calculated different biological aging epigenetic clocks of different generations (Horvath2013, Hannum2013, Li2018, Horvath skin and blood2018, PhenoAge2018, PCGrimAge2022), their corresponding age and intrinsic age accelerations, and DunedinPACE, all based on DNA methylation (Illumina EPIC array; pre-specified secondary outcome) for 256 participants with abdominal obesity or dyslipidemia, before and after the 18-month DIRECT PLUS randomized controlled trial. Three interventions were assigned: healthy dietary guidelines, a Mediterranean (MED) diet, and a polyphenol-rich, low-red/processed meat Green-MED diet. Both MED groups consumed 28 g walnuts/day (+ 440 mg/day polyphenols). The Green-MED group consumed green tea (3-4 cups/day) and Mankai (Wolffia globosa strain) 500-ml green shake (+ 800 mg/day polyphenols). Adherence to the Green-MED diet was assessed by questionnaire and urine polyphenols metabolomics (high-performance liquid chromatography quadrupole time of flight).

RESULTS: Baseline chronological age (51.3 ± 10.6 years) was significantly correlated with all methylation age (mAge) clocks with correlations ranging from 0.83 to 0.95; p < 2.2e - 16 for all. While all interventions did not differ in terms of changes between mAge clocks, greater Green-Med diet adherence was associated with a lower 18-month relative change (i.e., greater mAge attenuation) in Li and Hannum mAge (beta = - 0.41, p = 0.004 and beta = - 0.38, p = 0.03, respectively; multivariate models). Greater Li mAge attenuation (multivariate models adjusted for age, sex, baseline mAge, and weight loss) was mostly affected by higher intake of Mankai (beta = - 1.8; p = 0.061) and green tea (beta = - 1.57; p = 0.0016) and corresponded with elevated urine polyphenols: hydroxytyrosol, tyrosol, and urolithin C (p < 0.05 for all) and urolithin A (p = 0.08), highly common in green plants. Overall, participants undergoing either MED-style diet had ~ 8.9 months favorable difference between the observed and expected Li mAge at the end of the intervention (p = 0.02).

CONCLUSIONS: This study showed that MED and green-MED diets with increased polyphenols intake, such as green tea and Mankai, are inversely associated with biological aging. To the best of our knowledge, this is the first clinical trial to indicate a potential link between polyphenol intake, urine polyphenols, and biological aging.

TRIAL REGISTRATION: ClinicalTrials.gov, NCT03020186.

PMID:37743489 | DOI:10.1186/s12916-023-03067-3

Categories: Literature Watch

Rules and mechanisms governing G protein coupling selectivity of GPCRs

Sun, 2023-09-24 06:00

Cell Rep. 2023 Sep 22;42(10):113173. doi: 10.1016/j.celrep.2023.113173. Online ahead of print.

ABSTRACT

G protein-coupled receptors (GPCRs) convert extracellular stimuli into intracellular signaling by coupling to heterotrimeric G proteins of four classes: Gi/o, Gq, Gs, and G12/13. However, our understanding of the G protein selectivity of GPCRs is incomplete. Here, we quantitatively measure the enzymatic activity of GPCRs in living cells and reveal the G protein selectivity of 124 GPCRs with the exact rank order of their G protein preference. Using this information, we establish a classification of GPCRs by functional selectivity, discover the existence of a G12/13-coupled receptor, G15-coupled receptors, and a variety of subclasses for Gi/o-, Gq-, and Gs-coupled receptors, culminating in development of the predictive algorithm of G protein selectivity. We further identify the structural determinants of G protein selectivity, allowing us to synthesize non-existent GPCRs with de novo G protein selectivity and efficiently identify putative pathogenic variants.

PMID:37742189 | DOI:10.1016/j.celrep.2023.113173

Categories: Literature Watch

A risk assessment framework for multidrug-resistant Staphylococcus aureus using machine learning and mass spectrometry technology

Sun, 2023-09-24 06:00

Brief Bioinform. 2023 Sep 22;24(6):bbad330. doi: 10.1093/bib/bbad330.

ABSTRACT

The emergence of multidrug-resistant bacteria is a critical global crisis that poses a serious threat to public health, particularly with the rise of multidrug-resistant Staphylococcus aureus. Accurate assessment of drug resistance is essential for appropriate treatment and prevention of transmission of these deadly pathogens. Early detection of drug resistance in patients is critical for providing timely treatment and reducing the spread of multidrug-resistant bacteria. This study aims to develop a novel risk assessment framework for S. aureus that can accurately determine the resistance to multiple antibiotics. The comprehensive 7-year study involved ˃20 000 isolates with susceptibility testing profiles of six antibiotics. By incorporating mass spectrometry and machine learning, the study was able to predict the susceptibility to four different antibiotics with high accuracy. To validate the accuracy of our models, we externally tested on an independent cohort and achieved impressive results with an area under the receiver operating characteristic curve of 0. 94, 0.90, 0.86 and 0.91, and an area under the precision-recall curve of 0.93, 0.87, 0.87 and 0.81, respectively, for oxacillin, clindamycin, erythromycin and trimethoprim-sulfamethoxazole. In addition, the framework evaluated the level of multidrug resistance of the isolates by using the predicted drug resistance probabilities, interpreting them in the context of a multidrug resistance risk score and analyzing the performance contribution of different sample groups. The results of this study provide an efficient method for early antibiotic decision-making and a better understanding of the multidrug resistance risk of S. aureus.

PMID:37742050 | DOI:10.1093/bib/bbad330

Categories: Literature Watch

Schistosoma japonicum EKLF/KLF1 is a potential immune target to tackle schistosomiasis

Sat, 2023-09-23 06:00

Parasit Vectors. 2023 Sep 23;16(1):334. doi: 10.1186/s13071-023-05947-2.

ABSTRACT

BACKGROUND: Interruption of parasite reproduction by targeting migrating schistosomula is a promising strategy for managing schistosomiasis. Hepatic schistosomula proteins previously identified based on second-generation schistosome DNA sequencing were found to hold excellent potential for schistosomiasis japonica diagnosis and as vaccine candidates. However, there are still many unknown schistosomula proteins that warrant further investigations. Herein, a novel schistosomula protein, the Schistosoma japonicum erythroid Krüppel-like factor (SjEKLF/KLF1), was explored.

METHODS: Sequence alignment was carried out to detect the amino acid sequence characteristics of SjEKLF. The expression profile of SjEKLF was determined by western blot and immunofluorescence analysis. Enzyme-linked immunosorbent assay was used to determine the antigenicity of SjEKLF in hosts. Mice immunised with recombinant SjEKLF were challenged to test the potential value of the protein as an immunoprotective target.

RESULTS: SjEKLF is defined as EKLF/KLF1 for its C-terminal DNA-binding domain. SjEKLF is mainly expressed in hepatic schistosomula and male adults and located within the intestinal intima of the parasites. Notably, high levels of SjEKLF-specific antibodies were detected in host sera and SjEKLF exhibited outstanding sensitivity and specificity for schistosomiasis japonica immunodiagnosis but failed to distinguish between ongoing infection and previous exposure. In addition, SjEKLF immunisation reduced the infection in vivo, resulting in decreased worm and egg counts, and alleviated body weight loss and hepatomegaly in infected mice.

CONCLUSIONS: Overall, these findings demonstrate that SjEKLF is critical for the infection of S. japonicum and may be a potential target to help control S. japonicum infection and transmission.

PMID:37742024 | DOI:10.1186/s13071-023-05947-2

Categories: Literature Watch

Urinary peptides provide information about the risk of mortality across a spectrum of diseases and scenarios

Sat, 2023-09-23 06:00

J Transl Med. 2023 Sep 24;21(1):663. doi: 10.1186/s12967-023-04508-6.

ABSTRACT

BACKGROUND: There is evidence of pre-established vulnerability in individuals that increases the risk of their progression to severe disease or death, although the mechanisms causing this are still not fully understood. Previous research has demonstrated that a urinary peptide classifier (COV50) predicts disease progression and death from SARS-CoV-2 at an early stage, indicating that the outcome prediction may be partly due to vulnerabilities that are already present. The aim of this study is to examine the ability of COV50 to predict future non-COVID-19-related mortality, and evaluate whether the pre-established vulnerability can be generic and explained on a molecular level by urinary peptides.

METHODS: Urinary proteomic data from 9193 patients (1719 patients sampled at intensive care unit (ICU) admission and 7474 patients with other diseases (non-ICU)) were extracted from the Human Urinary Proteome Database. The previously developed COV50 classifier, a urinary proteomics biomarker panel consisting of 50 peptides, was applied to all datasets. The association of COV50 scoring with mortality was evaluated.

RESULTS: In the ICU group, an increase in the COV50 score of one unit resulted in a 20% higher relative risk of death [adjusted HR 1.2 (95% CI 1.17-1.24)]. The same increase in COV50 in non-ICU patients resulted in a higher relative risk of 61% [adjusted HR 1.61 (95% CI 1.47-1.76)], consistent with adjusted meta-analytic HR estimate of 1.55 [95% CI 1.39-1.73]. The most notable and significant changes associated with future fatal events were reductions of specific collagen fragments, most of collagen alpha I (I).

CONCLUSION: The COV50 classifier is predictive of death in the absence of SARS-CoV-2 infection, suggesting that it detects pre-existing vulnerability. This prediction is mainly based on collagen fragments, possibly reflecting disturbances in the integrity of the extracellular matrix. These data may serve as a basis for proteomics-guided intervention aiming towards manipulating/ improving collagen turnover, thereby reducing the risk of death.

PMID:37741989 | DOI:10.1186/s12967-023-04508-6

Categories: Literature Watch

The epidemiological and genetic characteristics of human parvovirus B19 in patients with febrile rash illnesses in China

Sat, 2023-09-23 06:00

Sci Rep. 2023 Sep 23;13(1):15913. doi: 10.1038/s41598-023-43158-y.

ABSTRACT

To understand the epidemiological and genetic characteristics of B19V, a multiple-province surveillance of patients with febrile rash illnesses (FRIs) were conducted in China during 2009 ~ 2021. The clinical specimens of 3,820 FRI patients were collected and tested for B19V DNA. A total of 99 (2.59%) patients were positive for B19V, and 49 (49.49%) were children under 5 years old. B19V infections occurred throughout the year without obvious seasonal pattern. Ten NS1-VP1u sequences and seven genome sequences were obtained in this study, identified as subgenotype 1a. Combined with the globally representative genome sequences, no temporal and geographic clustering trends of B19V were observed, and there was no significant correlation between B19V sequences and clinical manifestations. The evolutionary rate of the B19V genome was 2.30 × 10-4 substitutions/site/year. The number of negative selection sites was higher than that of positive selection sites. It was the first to comprehensively describe the prevalence patterns and evolutionary characteristics of B19V in FRI patients in China. B19V played the role in FRI patients. Children under 5 years old were the main population of B19V infection. Subgenotype 1a was prevalent in FRI patients in China. B19V showed a high mutation rate, while negative selection acted on the genome.

PMID:37741897 | DOI:10.1038/s41598-023-43158-y

Categories: Literature Watch

Understanding altruistic behavior: The joint role of prefrontal damage and OXTR genotype

Sat, 2023-09-23 06:00

Neuropsychologia. 2023 Sep 21:108686. doi: 10.1016/j.neuropsychologia.2023.108686. Online ahead of print.

ABSTRACT

Altruism is a type of prosocial behavior that is carried out in the absence of personal benefit or even at an expense to self. Trait altruism varies greatly across individuals, and the reasons for this variability are still not fully understood. Growing evidence suggests that altruism may be partly determined by the oxytocin receptor (OXTR) gene, which regulates the emotions underlying altruistic attitudes, such as empathy and trust. Neuroimaging and lesion studies have also implied several higher-order brain regions, including the prefrontal cortex, in altruistic behaviors. Yet the existing reports are contradictory and suggest that the top-down control exercised by the prefrontal cortex may promote both altruistic and self-interested behaviors and, thus, could obscure one's natural proclivity towards altruism encoded by OXTR. Here, we hypothesized that extensive prefrontal damage would result in an increased influence of the OXTR genotype on one's altruistic attitudes and actions. To test this hypothesis, we recruited 115 male combat veterans with penetrating traumatic brain injury to the prefrontal cortex and other brain regions, as well as 35 demographically matched control subjects without brain injury. Participants completed a self-report altruism questionnaire and were genotyped for four OXTR single nucleotide polymorphisms implicated in prosocial behavior, including rs53576, rs1042778, rs2254298 and rs7632287. Consistent with the previous studies, we found that individuals homozygotic for the G allele of rs53576 and rs7632287 were significantly more altruistic than carriers of at least one "vulnerable" A allele. Remarkably, in patients with prefrontal cortex damage, greater lesion extent was associated with significantly lower altruism scores in carriers of the A allele of rs7632287, but not in G-homozygotes, suggesting that significant disruption of the prefrontal cortex increased the influence of genetic polymorphisms on prosocial behavior. This study presents the first account of an interaction effect between the OXTR genotype and the location and extent of brain damage.

PMID:37741549 | DOI:10.1016/j.neuropsychologia.2023.108686

Categories: Literature Watch

CAN008 prolongs overall survival in patients with newly diagnosed GBM characterized by high tumor mutational burden

Sat, 2023-09-23 06:00

Biomed J. 2023 Sep 21:100660. doi: 10.1016/j.bj.2023.100660. Online ahead of print.

ABSTRACT

BACKGROUND: A previous phase 1 dose-escalation study in Taiwan indicated CAN008 (asunercept) with standard concurrent chemoradiotherapy (CCRT) improved progression-free survival (PFS) in newly diagnosed glioblastoma (GBM) patients. This study evaluates the efficacy of CAN008 in promoting overall survival (OS) and identifies genetic alterations associated with treatment responses.

METHODS: We compared OS of 5-year follow-ups from 9 evaluable CAN008 cohort patients (6 received high-dose and 3 received low-dose) to a historical Taiwanese GBM cohort with 164 newly diagnosed patients. CAN008 treatment response-associated genetic alterations were identified by whole-exome sequencing and comparing variant differences between response groups. Associations among patient survival, tumor mutational burden (TMB), and genetic alterations were analyzed using CAN008 cohort and TCGA-GBM dataset.

RESULTS: OS for high-dose CAN008 patients at 2 and 5 years was 83% and 67%, respectively, and 40.1% and 8.8% for the historical GBM cohort, respectively. Better OS was observed in the high-dose CAN008 cohort (without reaching the median survival) than the historical GBM cohort (median OS: 20 months; p=0.0103). Five high-dose CAN008 patients were divided into good and poor response groups based on their PFS. A higher variant count and TMB were observed in good response patients, whereas no significant association was observed between TMB and patient survival in the newly diagnosed TCGA-GBM dataset, suggesting TMB may modulate patient CAN008 response.

CONCLUSION: CAN008 combined with standard CCRT treatment prolonged the PFS and OS of newly diagnosed GBM patients compared to standard therapy alone. Higher treatment efficacy was associated with higher TMB.

PMID:37741340 | DOI:10.1016/j.bj.2023.100660

Categories: Literature Watch

Association between PROMIS10, SF-36 and NeuroQoL in persons with multiple sclerosis

Sat, 2023-09-23 06:00

Mult Scler Relat Disord. 2023 Sep 15;79:105003. doi: 10.1016/j.msard.2023.105003. Online ahead of print.

ABSTRACT

BACKGROUND: Patient reported outcome measures (PROs) are considered promising tools for use in clinical settings to measure the impact of disease on physical, mental and social well-being from the patient's perspective. The Patient Reported Outcome Measurement Information System Scale v1.1-Global Health (PROMIS-10) is a measure that is well-suited to clinical practice, but the relationships between this measure and longer PRO measures used in multiple sclerosis (MS) research are unknown.

METHODS: Subjects enrolled in SysteMS: A Systems Biology Study of Clinical, Radiological, and Molecular Markers in Subjects with MS at the Brigham and Women's Hospital were eligible to contribute to the study. 349 subjects completed three PRO measures at study entry: PROMIS-10, Medical Outcomes Study Short-Form 36 (SF-36), and Quality of Life in Neurological Disorders (Neuro-QoL™). All questions and global scores from PROMIS-10 were correlated with all domain and summary component scores for SF-36 and all domain scores for Neuro-QoL using Pearson's correlation coefficient. Further, the global scores from PROMIS-10 were correlated with the expanded disability status scale (EDSS) and compared between disease categories (relapsing vs progressive MS).

RESULTS: Strong correlations were observed between PROMIS-10 questions and SF-36 domains aimed at measuring the same construct. Further, the PROMIS-10 Global Physical Health score was correlated with the Physical Component Score from the SF-36 (r = 0.798), and the PROMIS Global Mental Health score was correlated with the Mental Component Score from the SF-36 (r = 0.726). Strong correlations between PROMIS-10 questions and two Neuro-QoL domains (fatigue and lower extremity function) were observed, but other Neuro-QoL domains were not strongly correlated with PROMIS-10 questions. PROMIS-10 Global Physical Health had stronger relationship to EDSS and disease category compared to the Global Mental Health.

CONCLUSIONS: PROMIS-10 questions and global scores are highly correlated with the corresponding domains of SF-36 in PwMS. Neuro-QoL provides different information regarding HRQOL since different domains are being measured.

PMID:37741027 | DOI:10.1016/j.msard.2023.105003

Categories: Literature Watch

MuDCoD: Multi-Subject Community Detection in Personalized Dynamic Gene Networks from Single Cell RNA Sequencing

Sat, 2023-09-23 06:00

Bioinformatics. 2023 Sep 23:btad592. doi: 10.1093/bioinformatics/btad592. Online ahead of print.

ABSTRACT

MOTIVATION: With the wide availability of single-cell RNA-seq (scRNA-seq) technology, population-scale scRNA-seq datasets across multiple individuals and time points are emerging. While the initial investigations of these datasets tend to focus on standard analysis of clustering and differential expression, leveraging the power of scRNA-seq data at the personalized dynamic gene co-expression network level has the potential to unlock subject and/or time-specific network-level variation, which is critical for understanding phenotypic differences. Community detection from co-expression networks of multiple time points or conditions has been well-studied; however, none of the existing settings included networks from multiple subjects and multiple time points simultaneously. To address this, we develop MuDCoD for multi-subject community detection in personalized dynamic gene networks from scRNA-seq. MuDCoD builds on the spectral clustering framework and promotes information sharing among the networks of the subjects as well as networks at different time points. It clusters genes in the personalized dynamic gene networks and reveals gene communities that are variable or shared not only across time but also among subjects.

RESULTS: Evaluation and benchmarking of MuDCoD against existing approaches reveal that MuDCoD effectively leverages apparent shared signals among networks of the subjects at individual time points, and performs robustly when there is no or little information sharing among the networks. Applications to population-scale scRNA-seq datasets of human-induced pluripotent stem cells during dopaminergic neuron differentiation and CD4+ T cell activation indicate that MuDCoD enables robust inference for identifying time-varying personalized gene modules. Our results illustrate how personalized dynamic community detection can aid in the exploration of subject-specific biological processes that vary across time.

AVAILABILITY: MuDCoD is publicly available at https://github.com/bo1929/MuDCoD as a Python package. Implementation includes simulation and real-data experiments together with extensive documentation.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

PMID:37740957 | DOI:10.1093/bioinformatics/btad592

Categories: Literature Watch

Frictional properties of phase-separated agarose hydrogels in water permeation

Sat, 2023-09-23 06:00

Soft Matter. 2023 Sep 22. doi: 10.1039/d3sm00814b. Online ahead of print.

ABSTRACT

We studied the friction coefficient between the polymer gel network and water f for thermoreversible agarose gels under various conditions of agarose concentration and gelation temperature. Since agarose gels exhibit phase separation below the gelation temperature, f strongly depends on the thermal history. We found that the friction coefficient of the phase-separated agarose gel normalized by the water viscosity, f/η, is expressed as f/η = S/ξνSD where ξSD is the frictional pore size and ν and S are constant parameters. ξSD corresponds to the correlation length of the frozen density fluctuations of the polymers via spinodal decomposition determined from small-angle light scattering. The least-squares analysis of the results shows that the exponent is ν ≃ 2 with the numerical constant of S ≃ 105/2π. The results suggest that the frictional properties of phase-separated agarose gels are dominated by the dilute regions of the bicontinuous gel structure.

PMID:37740384 | DOI:10.1039/d3sm00814b

Categories: Literature Watch

Compendium of Chromatographic Behavior of Post-translationally and Chemically Modified Peptides in Bottom-Up Proteomic Experiments

Fri, 2023-09-22 06:00

Anal Chem. 2023 Sep 22. doi: 10.1021/acs.analchem.3c02412. Online ahead of print.

ABSTRACT

We have systematically evaluated the chromatographic behavior of post-translationally/chemically modified peptides using data spanning over 70 of the most relevant modifications. These retention properties were measured for standard bottom-up proteomic settings (fully porous C18 separation media, 0.1% formic acid as ion-pairing modifier) using collections of modified/nonmodified peptide pairs. These pairs were generated by spontaneous degradation, chemical or enzymatic treatment, analysis of synthetic peptides, or the cotranslational incorporation of noncanonical proline analogues. In addition, these measurements were validated using external data acquired for synthetic peptides and enzymatically induced citrullination. Working in units of hydrophobicity index (HI, % ACN) and evaluating the average retention shifts (ΔHI) represent the simplest approach to describe the effect of modifications from a didactic point of view. Plotting HI values for modified (y-axis) vs nonmodified (x-axis) counterparts generates unique slope and intercept values for each modification defined by the chemistry of the modifying moiety: its hydrophobicity, size, pKa of ionizable groups, and position of the altered residue. These composition-dependent correlations can be used for coarse incorporation of PTMs into models for prediction of peptide retention. More accurate predictions would require the development of specific sequence-dependent algorithms to predict ΔHI values.

PMID:37739932 | DOI:10.1021/acs.analchem.3c02412

Categories: Literature Watch

Multi-omics indicators of long-term survival benefits after immune checkpoint inhibitor therapy

Fri, 2023-09-22 06:00

Cell Rep Methods. 2023 Sep 14:100596. doi: 10.1016/j.crmeth.2023.100596. Online ahead of print.

ABSTRACT

Molecular indicators of long-term survival (LTS) in response to immune-checkpoint inhibitor (ICI) treatment have the potential to provide both mechanistic and therapeutic insights. In this study, we construct predictive models of LTS following ICI therapy based on data from 158 clinical trials involving 21,023 patients of 25 cancer types with available 1-year overall survival (OS) rates. We present evidence for the use of 1-year OS rate as a surrogate for LTS. Based on these and corresponding TCGA multi-omics data, total neoantigen, metabolism score, CD8+ T cell, and MHC_score were identified as predictive biomarkers. These were integrated into a Gaussian process regression model that estimates "long-term survival predictive score of immunotherapy" (iLSPS). We found that iLSPS outperformed the predictive capabilities of individual biomarkers and successfully predicted LTS of patient groups with melanoma and lung cancer. Our study explores the feasibility of modeling LTS based on multi-omics indicators and machine-learning methods.

PMID:37738982 | DOI:10.1016/j.crmeth.2023.100596

Categories: Literature Watch

SARS-CoV-2 variants evolve convergent strategies to remodel the host response

Fri, 2023-09-22 06:00

Cell. 2023 Sep 19:S0092-8674(23)00915-7. doi: 10.1016/j.cell.2023.08.026. Online ahead of print.

ABSTRACT

SARS-CoV-2 variants of concern (VOCs) emerged during the COVID-19 pandemic. Here, we used unbiased systems approaches to study the host-selective forces driving VOC evolution. We discovered that VOCs evolved convergent strategies to remodel the host by modulating viral RNA and protein levels, altering viral and host protein phosphorylation, and rewiring virus-host protein-protein interactions. Integrative computational analyses revealed that although Alpha, Beta, Gamma, and Delta ultimately converged to suppress interferon-stimulated genes (ISGs), Omicron BA.1 did not. ISG suppression correlated with the expression of viral innate immune antagonist proteins, including Orf6, N, and Orf9b, which we mapped to specific mutations. Later Omicron subvariants BA.4 and BA.5 more potently suppressed innate immunity than early subvariant BA.1, which correlated with Orf6 levels, although muted in BA.4 by a mutation that disrupts the Orf6-nuclear pore interaction. Our findings suggest that SARS-CoV-2 convergent evolution overcame human adaptive and innate immune barriers, laying the groundwork to tackle future pandemics.

PMID:37738970 | DOI:10.1016/j.cell.2023.08.026

Categories: Literature Watch

circAtlas 3.0: a gateway to 3 million curated vertebrate circular RNAs based on a standardized nomenclature scheme

Fri, 2023-09-22 06:00

Nucleic Acids Res. 2023 Sep 22:gkad770. doi: 10.1093/nar/gkad770. Online ahead of print.

ABSTRACT

Recent studies have demonstrated the important regulatory role of circRNAs, but an in-depth understanding of the comprehensive landscape of circRNAs across various species still remains unexplored. The current circRNA databases are often species-restricted or based on outdated datasets. To address this challenge, we have developed the circAtlas 3.0 database, which contains a rich collection of 2674 circRNA sequencing datasets, curated to delineate the landscape of circRNAs within 33 distinct tissues spanning 10 vertebrate species. Notably, circAtlas 3.0 represents a substantial advancement over its precursor, circAtlas 2.0, with the number of cataloged circRNAs escalating from 1 007 087 to 3 179 560, with 2 527 528 of them being reconstructed into full-length isoforms. circAtlas 3.0 also introduces several notable enhancements, including: (i) integration of both Illumina and Nanopore sequencing datasets to detect circRNAs of extended lengths; (ii) employment of a standardized nomenclature scheme for circRNAs, providing information of the host gene and full-length circular exons; (iii) inclusion of clinical cancer samples to explore the biological function of circRNAs within the context of cancer and (iv) links to other useful resources to enable user-friendly analysis of target circRNAs. The updated circAtlas 3.0 provides an important platform for exploring the evolution and biological implications of vertebrate circRNAs, and is freely available at http://circatlas.biols.ac.cn and https://ngdc.cncb.ac.cn/circatlas.

PMID:37739414 | DOI:10.1093/nar/gkad770

Categories: Literature Watch

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