Systems Biology

Heterodimerization domains in MAP4 KINASEs determine subcellular localization and activity in Arabidopsis

Thu, 2024-03-21 06:00

Plant Physiol. 2024 Mar 21:kiae176. doi: 10.1093/plphys/kiae176. Online ahead of print.

ABSTRACT

Signal transduction relies largely on the activity of kinases and phosphatases that control protein phosphorylation. However, we still know very little about phosphorylation-mediated signaling networks. Plant MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASEs (MAP4Ks) have recently gained more attention, given their role in a wide range of processes, including developmental processes and stress signaling. We analyzed MAP4K expression patterns and mapped protein-MAP4K interactions in Arabidopsis (Arabidopsis thaliana), revealing extensive co-expression and heterodimerization. This heterodimerization is regulated by the C-terminal, intrinsically disordered half of the MAP4K, and specifically by the coiled coil motif. The ability to heterodimerize is required for proper activity and localization of the MAP4Ks. Taken together, our results identify MAP4K-interacting proteins and emphasize the functional importance of MAP4K heterodimerization. Furthermore, we identified MAP4K4/TARGET OF TEMPERATURE3 (TOT3) and MAP4K5/TOT3-INTERACTING PROTEIN 5 (TOI5) as key regulators of the transition from cell division to elongation zones in the primary root tip.

PMID:38513700 | DOI:10.1093/plphys/kiae176

Categories: Literature Watch

Gut microbiota-dependent modulation of pre-metastatic niches by Jianpi Yangzheng decoction in the prevention of lung metastasis of gastric cancer

Thu, 2024-03-21 06:00

Phytomedicine. 2024 Feb 4;128:155413. doi: 10.1016/j.phymed.2024.155413. Online ahead of print.

ABSTRACT

AIM OF THE STUDY: To evaluate the in vitro and in vivo anti-metastasis efficacy of Jianpi Yangzheng (JPYZ) decoction against gastric cancer (GC) and its potential mechanisms.

MATERIALS AND METHODS: The distant metastasis of GC cells administered via tail vein injection was assessed using the pre-metastatic niche (PMN) model. 16S rRNA sequencing and GC-MS/MS were applied to determine the component of the gut microbiota and content of short-chain fatty acids (SCFAs) in feces of mice, respectively. The proportion of myeloid-derived suppressor cells (MDSCs) in the lung was evaluated by flow cytometry and immunofluorescence. Serum or tissue levels of inflammation factors including IL-6, IL-10 and TGF-β were determined by ELISA or Western blot respectively.

RESULTS: Injecting GC cells into the tail vein of mice led to the development of lung metastases and also resulted in alterations in the composition of gut microbiota and the levels of SCFAs produced. Nevertheless, JPYZ treatment robustly impeded the effect of GC cells administration. Mechanically, JPYZ treatment not only prevented the alteration in gut microbiota structure, but also restored the SCFAs content induced by GC cells administration. Specifically, JPYZ treatment recovered the relative abundance of genera Moryella, Helicobacter, Lachnoclostridium, Streptococcus, Tuzzerella, GCA-900066575, uncultured_Lachnospiraceae, Rikenellaceae_RC9_gut_group and uncultured_bacterium_Muribaculaceae to near the normal control levels. In addition, JPYZ abrogated MDSCs accumulation in the lung tissue and blocked inflammation factors overproduction in the serum and lung tissues, which subsequently impede the formation of the immunosuppressive microenvironment. Correlation analysis revealed that the prevalence of Rikenellaceae in the model group exhibited a positive correlation with MDSCs proportion and inflammation factor levels. Conversely, the scarcity of Muribaculaceae in the model group showed a negative correlation with these parameters. This suggests that JPYZ might exert an influence on the gut microbiota and their metabolites, such as SCFAs, potentially regulating the formation of the PMN and consequently impacting the outcome of GC metastasis.

CONCLUSION: These findings suggest that GC cells facilitate metastasis by altering the gut microbiota composition, affecting the production of SCFAs, and recruiting MDSCs to create a pro-inflammatory pre-metastatic niche. JPYZ decoction counteracts this process by reshaping the gut microbiota structure, enhancing SCFA production, and inhibiting the formation of the pre-metastatic microenvironment, thereby exerting an anti-metastatic effect.

PMID:38513377 | DOI:10.1016/j.phymed.2024.155413

Categories: Literature Watch

The focal adhesion protein talin is a mechanically gated A-kinase anchoring protein

Thu, 2024-03-21 06:00

Proc Natl Acad Sci U S A. 2024 Mar 26;121(13):e2314947121. doi: 10.1073/pnas.2314947121. Epub 2024 Mar 21.

ABSTRACT

Protein kinase A (PKA) is a ubiquitous, promiscuous kinase whose activity is specified through subcellular localization mediated by A-kinase anchoring proteins (AKAPs). PKA has complex roles as both an effector and a regulator of integrin-mediated cell adhesion to extracellular matrix (ECM). Recent observations demonstrate that PKA is an active component of focal adhesions (FA), suggesting the existence of one or more FA AKAPs. Using a promiscuous biotin ligase fused to PKA type-IIα regulatory (RIIα) subunits and subcellular fractionation, we identify the archetypal FA protein talin1 as an AKAP. Talin is a large, mechanosensitive scaffold that directly links integrins to actin filaments and promotes FA assembly by recruiting additional components in a force-dependent manner. The rod region of talin1 consists of 62 α-helices bundled into 13 rod domains, R1 to R13. Direct binding assays and NMR spectroscopy identify helix41 in the R9 subdomain of talin as the PKA binding site. PKA binding to helix41 requires unfolding of the R9 domain, which requires the linker region between R9 and R10. Experiments with single molecules and in cells manipulated to alter actomyosin contractility demonstrate that the PKA-talin interaction is regulated by mechanical force across the talin molecule. Finally, talin mutations that disrupt PKA binding also decrease levels of total and phosphorylated PKA RII subunits as well as phosphorylation of VASP, a known PKA substrate, within FA. These observations identify a mechanically gated anchoring protein for PKA, a force-dependent binding partner for talin1, and a potential pathway for adhesion-associated mechanotransduction.

PMID:38513099 | DOI:10.1073/pnas.2314947121

Categories: Literature Watch

Structure and function of the <em>Arabidopsis</em> ABC transporter ABCB19 in brassinosteroid export

Thu, 2024-03-21 06:00

Science. 2024 Mar 22;383(6689):eadj4591. doi: 10.1126/science.adj4591. Epub 2024 Mar 22.

ABSTRACT

Brassinosteroids are steroidal phytohormones that regulate plant development and physiology, including adaptation to environmental stresses. Brassinosteroids are synthesized in the cell interior but bind receptors at the cell surface, necessitating a yet to be identified export mechanism. Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.

PMID:38513023 | DOI:10.1126/science.adj4591

Categories: Literature Watch

mNFE: microbiome network flow entropy for detecting pre-disease states of type 1 diabetes

Thu, 2024-03-21 06:00

Gut Microbes. 2024 Jan-Dec;16(1):2327349. doi: 10.1080/19490976.2024.2327349. Epub 2024 Mar 21.

ABSTRACT

In the development of Type 1 diabetes (T1D), there are critical states just before drastic changes, and identifying these pre-disease states may predict T1D or provide crucial early-warning signals. Unlike gene expression data, gut microbiome data can be collected noninvasively from stool samples. Gut microbiome sequencing data contain different levels of phylogenetic information that can be utilized to detect the tipping point or critical state in a reliable manner, thereby providing accurate and effective early-warning signals. However, it is still difficult to detect the critical state of T1D based on gut microbiome data due to generally non-significant differences between healthy and critical states. To address this problem, we proposed a new method - microbiome network flow entropy (mNFE) based on a single sample from each individual - for detecting the critical state before seroconversion and abrupt transitions of T1D at various taxonomic levels. The numerical simulation validated the robustness of mNFE under different noise levels. Furthermore, based on real datasets, mNFE successfully identified the critical states and their dynamic network biomarkers (DNBs) at different taxonomic levels. In addition, we found some high-frequency species, which are closely related to the unique clinical characteristics of autoantibodies at the four levels, and identified some non-differential 'dark species' play important roles during the T1D progression. mNFE can robustly and effectively detect the pre-disease states at various taxonomic levels and identify the corresponding DNBs with only a single sample for each individual. Therefore, our mNFE method provides a new approach not only for T1D pre-disease diagnosis or preventative treatment but also for preventative medicine of other diseases by gut microbiome.

PMID:38512768 | DOI:10.1080/19490976.2024.2327349

Categories: Literature Watch

Identification of pine wood nematode (Bur1aphelenchus xylophilus) loading response genes in Japanese pine sawyer (Monochamus alternatus) through comparative genomics and transcriptomics

Thu, 2024-03-21 06:00

Pest Manag Sci. 2024 Mar 21. doi: 10.1002/ps.8090. Online ahead of print.

ABSTRACT

BACKGROUND: Pine wood nematode (PWN; Bursaphelenchus xylophilus) is the causative agent of pine wilt disease (PWD), which is considered the most dangerous biohazard to conifer trees globally. The transmission of PWN relies on insect vectors, particularly the Japanese pine sawyer (JPS; Monochamus alternatus). However, the molecular mechanism underlying PWN-JPS assembly remains largely unknown.

RESULTS: Here, we found that both geographical and gender could significantly affect the PCA (PWN carrying amount) of JPS; thus, JPS transcriptomes from diverse locations and genders were explored regard to PWN loading. Due to the shortage of genomes, we developed a full-length reference transcriptome for analyzing next-generation sequencing data. A comparative genomic study was performed, and 11 248 potential PWN-carrying associate genes (β) were nominated in JPS by using the reported genomes of PWN and non-PWN carrier insect species. Then, 151 differentially expressed transcripts (DETs), 28 of them overlapped with β, correlated with the PCA of JPS were nominated by RNA-Seq, and found that fatty acid β-oxidation might be the key factor that affected the PCA of JPS. Furthermore, JPS fatty acid β-oxidation rates were experimentally decreased using the inhibitor Etomoxir, leading to an increased PCA of JPS. Meanwhile, silencing MaCPT1 in JPS by RNA interference led to a decreased fatty acid β-oxidation rate and increased PCA of JPS.

CONCLUSIONS: In conclusion, MaCPT1 was able to decrease the PWN-JPS assembly formation through the fatty acid β-oxidation of JPS. These results provide new insights for exploring the impact of PWN invasion on JPS. This article is protected by copyright. All rights reserved.

PMID:38511764 | DOI:10.1002/ps.8090

Categories: Literature Watch

Rational evolution for altering the ligand preference of estrogen receptor alpha

Thu, 2024-03-21 06:00

Protein Sci. 2024 Apr;33(4):e4940. doi: 10.1002/pro.4940.

ABSTRACT

Estrogen receptor α is commonly used in synthetic biology to control the activity of genome editing tools. The activating ligands, estrogens, however, interfere with various cellular processes, thereby limiting the applicability of this receptor. Altering its ligand preference to chemicals of choice solves this hurdle but requires adaptation of unspecified ligand-interacting residues. Here, we provide a solution by combining rational protein design with multi-site-directed mutagenesis and directed evolution of stably integrated variants in Saccharomyces cerevisiae. This method yielded an estrogen receptor variant, named TERRA, that lost its estrogen responsiveness and became activated by tamoxifen, an anti-estrogenic drug used for breast cancer treatment. This tamoxifen preference of TERRA was maintained in mammalian cells and mice, even when fused to Cre recombinase, expanding the mammalian synthetic biology toolbox. Not only is our platform transferable to engineer ligand preference of any steroid receptor, it can also profile drug-resistance landscapes for steroid receptor-targeted therapies.

PMID:38511482 | DOI:10.1002/pro.4940

Categories: Literature Watch

Receptors underlying an odorant's valence across concentrations in Drosophila Larvae

Thu, 2024-03-21 06:00

J Exp Biol. 2024 Mar 21:jeb.247215. doi: 10.1242/jeb.247215. Online ahead of print.

ABSTRACT

Odorants interact with receptors expressed in specialized olfactory neurons, and neurons of the same class send their axons to distinct glomeruli in the brain. The stereotypic spatial glomerular activity map generates recognition and behavioral response for the odorant. The valence of an odorant changes with concentration, typically becoming aversive at higher concentrations. Interestingly in the Drosophila larvae, the odorant (E)-2-hexenal is aversive at low concentrations and attractive at higher concentrations. We investigate the molecular and neural basis of this phenomenon focusing on how activities of different olfactory neurons conveying opposing effects dictate behaviors. We identify the repellant neuron in the larvae as one expressing the olfactory receptor Or7a, whose activation alone at low concentrations of (E)-2-hexenal elicits an avoidance response in an Or7a dependent manner. We demonstrate that avoidance can be overcome at higher concentrations by activation of additional neurons that are known to be attractive, most notably known activators of Or42a and Or85c. These findings suggest that in the larval stage, the attraction-conveying neurons can overcome the aversion-conveying channels for (E)-2-hexenal.

PMID:38511428 | DOI:10.1242/jeb.247215

Categories: Literature Watch

Monocyte-Mediated Thrombosis Linked to Circulating Tissue Factor and Immune Paralysis in COVID-19

Thu, 2024-03-21 06:00

Arterioscler Thromb Vasc Biol. 2024 Mar 21. doi: 10.1161/ATVBAHA.122.318721. Online ahead of print.

ABSTRACT

BACKGROUND: SARS-CoV-2 infections cause COVID-19 and are associated with inflammation, coagulopathy, and high incidence of thrombosis. Myeloid cells help coordinate the initial immune response in COVID-19. Although we appreciate that myeloid cells lie at the nexus of inflammation and thrombosis, the mechanisms that unite the two in COVID-19 remain largely unknown.

METHODS: In this study, we used systems biology approaches including proteomics, transcriptomics, and mass cytometry to define the circulating proteome and circulating immune cell phenotypes in subjects with COVID-19.

RESULTS: In a cohort of subjects with COVID-19 (n=35), circulating markers of inflammation (CCL23 and IL [interleukin]-6) and vascular dysfunction (ACE2 [angiotensin-converting enzyme 2] and TF [tissue factor]) were elevated in subjects with severe compared with mild COVID-19. Additionally, although the total white blood cell counts were similar between COVID-19 groups, CD14+ monocytes from subjects with severe COVID-19 expressed more TF. At baseline, transcriptomics demonstrated increased IL-6, CCL3, ACOD1, C5AR1, C5AR2, and TF in subjects with severe COVID-19 compared with controls. Using stress transcriptomics, we found that circulating immune cells from subjects with severe COVID-19 had evidence of profound immune paralysis with greatly reduced transcriptional activation and release of inflammatory markers in response to TLR (Toll-like receptor) activation. Finally, sera from subjects with severe (but not mild) COVID-19 activated human monocytes and induced TF expression.

CONCLUSIONS: Taken together, these observations further elucidate the pathological mechanisms that underlie immune dysfunction and coagulation abnormalities in COVID-19, contributing to our growing understanding of SARS-CoV-2 infections that could also be leveraged to develop novel diagnostic and therapeutic strategies.

PMID:38511328 | DOI:10.1161/ATVBAHA.122.318721

Categories: Literature Watch

Type I Interferons: leukemia's old foe in the limelight again

Thu, 2024-03-21 06:00

Haematologica. 2024 Mar 21. doi: 10.3324/haematol.2024.285079. Online ahead of print.

ABSTRACT

Not available.

PMID:38511262 | DOI:10.3324/haematol.2024.285079

Categories: Literature Watch

STAT6-targeting antisense oligonucleotides against solitary fibrous tumor

Thu, 2024-03-21 06:00

Mol Ther Nucleic Acids. 2024 Feb 15;35(2):102154. doi: 10.1016/j.omtn.2024.102154. eCollection 2024 Jun 11.

ABSTRACT

Solitary fibrous tumor (SFT) is a rare, non-hereditary soft tissue sarcoma thought to originate from fibroblastic mesenchymal stem cells. The etiology of SFT is thought to be due to an environmental intrachromosomal gene fusion between NGFI-A-binding protein 2 (NAB2) and signal transducer and activator protein 6 (STAT6) genes on chromosome 12, wherein the activation domain of STAT6 is fused with the DNA-binding domain of NAB2 resulting in the oncogenesis of SFT. All NAB2-STAT6 fusion variations discovered in SFTs contain the C-terminal of STAT6 transcript, and thus can serve as target site for antisense oligonucleotides (ASOs)-based therapies. Indeed, our in vitro studies show the STAT6 3' untranslated region (UTR)-targeting ASO (ASO 993523) was able to reduce expression of NAB2-STAT6 fusion transcripts in multiple SFT cell models with high efficiency (half-maximal inhibitory concentration: 116-300 nM). Encouragingly, in vivo treatment of SFT patient-derived xenograft mouse models with ASO 993523 resulted in acceptable tolerability profiles, reduced expression of NAB2-STAT6 fusion transcripts in xenograft tissues (21.9%), and, importantly, reduced tumor growth (32.4% decrease in tumor volume compared with the untreated control). Taken together, our study established ASO 993523 as a potential agent for the treatment of SFTs.

PMID:38511173 | PMC:PMC10950871 | DOI:10.1016/j.omtn.2024.102154

Categories: Literature Watch

Differential gene expression analysis pipelines and bioinformatic tools for the identification of specific biomarkers: A review

Thu, 2024-03-21 06:00

Comput Struct Biotechnol J. 2024 Mar 1;23:1154-1168. doi: 10.1016/j.csbj.2024.02.018. eCollection 2024 Dec.

ABSTRACT

In recent years, the role of bioinformatics and computational biology together with omics techniques and transcriptomics has gained tremendous importance in biomedicine and healthcare, particularly for the identification of biomarkers for precision medicine and drug discovery. Differential gene expression (DGE) analysis is one of the most used techniques for RNA-sequencing (RNA-seq) data analysis. This tool, which is typically used in various RNA-seq data processing applications, allows the identification of differentially expressed genes across two or more sample sets. Functional enrichment analyses can then be performed to annotate and contextualize the resulting gene lists. These studies provide valuable information about disease-causing biological processes and can help in identifying molecular targets for novel therapies. This review focuses on differential gene expression (DGE) analysis pipelines and bioinformatic techniques commonly used to identify specific biomarkers and discuss the advantages and disadvantages of these techniques.

PMID:38510977 | PMC:PMC10951429 | DOI:10.1016/j.csbj.2024.02.018

Categories: Literature Watch

VIPERA: Viral Intra-Patient Evolution Reporting and Analysis

Thu, 2024-03-21 06:00

Virus Evol. 2024 Mar 6;10(1):veae018. doi: 10.1093/ve/veae018. eCollection 2024.

ABSTRACT

Viral mutations within patients nurture the adaptive potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during chronic infections, which are a potential source of variants of concern. However, there is no integrated framework for the evolutionary analysis of intra-patient SARS-CoV-2 serial samples. Herein, we describe Viral Intra-Patient Evolution Reporting and Analysis (VIPERA), a new software that integrates the evaluation of the intra-patient ancestry of SARS-CoV-2 sequences with the analysis of evolutionary trajectories of serial sequences from the same viral infection. We have validated it using positive and negative control datasets and have successfully applied it to a new case, which revealed population dynamics and evidence of adaptive evolution. VIPERA is available under a free software license at https://github.com/PathoGenOmics-Lab/VIPERA.

PMID:38510921 | PMC:PMC10953798 | DOI:10.1093/ve/veae018

Categories: Literature Watch

ΔNp63 regulates MDSC survival and metabolism in triple-negative breast cancer

Thu, 2024-03-21 06:00

iScience. 2024 Feb 29;27(4):109366. doi: 10.1016/j.isci.2024.109366. eCollection 2024 Apr 19.

ABSTRACT

Triple-negative breast cancer (TNBC) contributes greatly to mortality of breast cancer, demanding new targetable options. We have shown that TNBC patients have high ΔNp63 expression in tumors. However, the function of ΔNp63 in established TNBC is yet to be explored. In current studies, targeting ΔNp63 with inducible CRISPR knockout and Histone deacetylase inhibitor Quisinostat showed that ΔNp63 is important for tumor progression and metastasis in established tumors by promoting myeloid-derived suppressor cell (MDSC) survival through tumor necrosis factor alpha. Decreasing ΔNp63 levels are associated with decreased CD4+ and FOXP3+ T-cells but increased CD8+ T-cells. RNA sequencing analysis indicates that loss of ΔNp63 alters multiple MDSC properties such as lipid metabolism, chemotaxis, migration, and neutrophil degranulation besides survival. We further demonstrated that targeting ΔNp63 sensitizes chemotherapy. Overall, we showed that ΔNp63 reprograms the MDSC-mediated immunosuppressive functions in TNBC, highlighting the benefit of targeting ΔNp63 in chemotherapy-resistant TNBC.

PMID:38510127 | PMC:PMC10951988 | DOI:10.1016/j.isci.2024.109366

Categories: Literature Watch

GLIMS: A two-stage gradual-learning method for cancer genes prediction using multi-omics data and co-splicing network

Thu, 2024-03-21 06:00

iScience. 2024 Mar 2;27(4):109387. doi: 10.1016/j.isci.2024.109387. eCollection 2024 Apr 19.

ABSTRACT

Identifying cancer genes is vital for cancer diagnosis and treatment. However, because of the complexity of cancer occurrence and limited cancer genes knowledge, it is hard to identify cancer genes accurately using only a few omics data, and the overall performance of existing methods is being called for further improvement. Here, we introduce a two-stage gradual-learning strategy GLIMS to predict cancer genes using integrative features from multi-omics data. Firstly, it uses a semi-supervised hierarchical graph neural network to predict the initial candidate cancer genes by integrating multi-omics data and protein-protein interaction (PPI) network. Then, it uses an unsupervised approach to further optimize the initial prediction by integrating the co-splicing network in post-transcriptional regulation, which plays an important role in cancer development. Systematic experiments on multi-omics cancer data demonstrated that GLIMS outperforms the state-of-the-art methods for the identification of cancer genes and it could be a useful tool to help advance cancer analysis.

PMID:38510118 | PMC:PMC10951990 | DOI:10.1016/j.isci.2024.109387

Categories: Literature Watch

Molecular characterization of ESBL-producing uropathogenic <em>Escherichia coli</em> isolates among kidney transplant patients: Emergence and spread of B2-ST131 clone type

Thu, 2024-03-21 06:00

Heliyon. 2024 Mar 7;10(6):e27339. doi: 10.1016/j.heliyon.2024.e27339. eCollection 2024 Mar 30.

ABSTRACT

This study was conducted to identify the distribution of virulence determinants in uropathogenic Escherichia coli (UPEC) isolates obtained from kidney transplant (KTP) and non-transplant patients (non-KTP) with urinary tract infections (UTI). Additionally, the (GTG)5 fingerprinting technique was used to investigate the genetic diversity of Extended-Spectrum B-Lactamase (ESBL)-positive isolates. In this case-control study, 111 urine isolates were obtained from non-KTPs and KTPs, respectively. The presence of genetic markers encoding adhesion proteins, toxins and major E. coli phylogroups was assessed through PCR amplification. Molecular typing of ESBL-positive UPEC strains was performed using (GTG)5 fingerprinting and Multilocus sequence typing (MLST) techniques. Overall, 65 and 46 UPEC isolates were obtained from non-KTPs and KTPs, respectively. Among the studied isolates, traT (85.6%) gene was the most frequently observed virulence gene, followed by kpsMT (49.5%). Using the 80% cut-off point, all the 35 UPEC isolates were classified into four major clusters, namely A, B, C, and D. The majority of the Sequence Type (ST) 131 isolates belonged to cluster A. Additionally, three ST1193 isolates belonged to cluster A and phylogroup B2. Moreover, ST38, ST131 and ST10 were in different cluster. In general, we observed significant differences in the papA, ompT, sat, and vat genes between KTPs and non-KTPs. Furthermore, since all the isolates carried one or more virulence factors (VFs), these findings are concerning in the context of managing UTIs caused by the UPEC strain. Additionally, the distribution of ST and Clonal Complex (CC) among isolates in the main clusters revealed significant differences between MLST and (GTG)5 fingerprinting analysis.

PMID:38510019 | PMC:PMC10951548 | DOI:10.1016/j.heliyon.2024.e27339

Categories: Literature Watch

Evaluation of in vitro corrosion behavior and biocompatibility of poly[xylitol-(1,12-dodecanedioate)](PXDD)-HA coated porous iron for bone scaffolds applications

Thu, 2024-03-21 06:00

Biotechnol J. 2024 Mar;19(3):e2300464. doi: 10.1002/biot.202300464.

ABSTRACT

The present study evaluates the corrosion behavior of poly[xylitol-(1,12-dodecanedioate)](PXDD)-HA coated porous iron (PXDD140/HA-Fe) and its cell-material interaction aimed for temporary bone scaffold applications. The physicochemical analyses show that the addition of 20 wt.% HA into the PXDD polymers leads to a higher crystallinity and lower surface roughness. The corrosion assessments of the PXDD140/HA-Fe evaluated by electrochemical methods and surface chemistry analysis indicate that HA decelerates Fe corrosion due to a lower hydrolysis rate following lower PXDD content and being more crystalline. The cell viability and cell death mode evaluations of the PXDD140/HA-Fe exhibit favorable biocompatibility as compared to bare Fe and PXDD-Fe scaffolds owing to HA's bioactive properties. Thus, the PXDD140/HA-Fe scaffolds possess the potential to be used as a biodegradable bone implant.

PMID:38509814 | DOI:10.1002/biot.202300464

Categories: Literature Watch

Drivers of Geographic Patterns in Outpatient Antibiotic Prescribing in the United States

Thu, 2024-03-21 06:00

Clin Infect Dis. 2024 Mar 21:ciae111. doi: 10.1093/cid/ciae111. Online ahead of print.

ABSTRACT

In a retrospective, ecological analysis of US medical claims, visit rates explained more of the geographic variation in outpatient antibiotic prescribing rates than per-visit prescribing. Efforts to reduce antibiotic use may benefit from addressing the factors that drive higher rates of outpatient visits, in addition to continued focus on stewardship.

PMID:38509670 | DOI:10.1093/cid/ciae111

Categories: Literature Watch

The role of supervision and motivation during exercise on physical and mental health in older adults: a study protocol for a randomized controlled trial (PRO-Training project)

Thu, 2024-03-21 06:00

BMC Geriatr. 2024 Mar 20;24(1):274. doi: 10.1186/s12877-024-04868-8.

ABSTRACT

BACKGROUND: Although supervised exercise is frequently recommended for older adults, its superiority over unsupervised exercise remains uncertain. Furthermore, whether motivational techniques could help to enhance the effectiveness of the latter remains to be elucidated. The present randomized controlled trial aims to determine the role of supervision and motivational strategies on the safety, adherence, efficacy, and cost-effectiveness of different exercise programs for improving physical and mental health in older adults.

METHODS: Participants (n = 120, aged 60-75 years) will be randomly allocated into five groups: 1-Control (CON), 2-Supervised exercise without motivational intervention (SUP), 3- Supervised exercise with motivational intervention (SUP +), 4- Unsupervised exercise without motivational intervention (UNSUP) and 5- Unsupervised exercise with motivational intervention (UNSUP +). Over 24 weeks, all exercise groups will participate in a multicomponent exercise program three times/week (performed in group classes at a center for SUP and SUP + , or home without supervision but with the help of a mobile app for UNSUP and UNSUP +), while the CON group will maintain their usual lifestyle. The motivational intervention (for SUP + and UNSUP + groups) will be based on the self-determination theory, including strategies such as phone calls, interactive workshops, motivational messages, informative infographics and videos. Primary outcomes will include safety, adherence, costs, and lower-body muscular function using a leg press machine. Secondary outcomes will include upper-body muscular function, physical and cardiorespiratory function, blood pressure and heart rate, body composition, health-related quality of life, cognitive performance, anxiety, depression, physical activity levels, sleep and sedentarism, biochemical markers, motivators and barriers to exercise. Assessments will be conducted at baseline, mid-intervention (i.e., week 13), at the end of the intervention (i.e., week 25), and 24 weeks later (i.e., week 49).

DISCUSSION: The findings of this trial might provide valuable insights into the role of supervision and motivational strategies on the effectiveness of exercise programs for older adults. Additionally, the study could contribute to developing cost-effective interventions, supporting the design of future public policies for healthy aging.

TRIAL REGISTRATION: NCT05619250. Registered 16 November 2022.

PMID:38509514 | DOI:10.1186/s12877-024-04868-8

Categories: Literature Watch

Increased enhancer-promoter interactions during developmental enhancer activation in mammals

Thu, 2024-03-21 06:00

Nat Genet. 2024 Mar 20. doi: 10.1038/s41588-024-01681-2. Online ahead of print.

ABSTRACT

Remote enhancers are thought to interact with their target promoters via physical proximity, yet the importance of this proximity for enhancer function remains unclear. Here we investigate the three-dimensional (3D) conformation of enhancers during mammalian development by generating high-resolution tissue-resolved contact maps for nearly a thousand enhancers with characterized in vivo activities in ten murine embryonic tissues. Sixty-one percent of developmental enhancers bypass their neighboring genes, which are often marked by promoter CpG methylation. The majority of enhancers display tissue-specific 3D conformations, and both enhancer-promoter and enhancer-enhancer interactions are moderately but consistently increased upon enhancer activation in vivo. Less than 14% of enhancer-promoter interactions form stably across tissues; however, these invariant interactions form in the absence of the enhancer and are likely mediated by adjacent CTCF binding. Our results highlight the general importance of enhancer-promoter physical proximity for developmental gene activation in mammals.

PMID:38509385 | DOI:10.1038/s41588-024-01681-2

Categories: Literature Watch

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