Systems Biology
Indole-3-Propionic Acid, a Gut Microbiota-Derived Tryptophan Metabolite, Promotes Endothelial Dysfunction Impairing Purinergic-Induced Nitric Oxide Release in Endothelial Cells
Int J Mol Sci. 2024 Mar 16;25(6):3389. doi: 10.3390/ijms25063389.
ABSTRACT
Different gut microbiota-derived metabolites influence cardiovascular function, and, among all, the role of indole-3-propionic acid (IPA), from tryptophan metabolism, shows controversial effects. The aim of this study was to evaluate its role in endothelial dysfunction. IPA effects were studied on bovine aortic endothelial cells (BAE-1). First, IPA cytotoxicity was evaluated by an MTS assay. Then, the levels of intracellular reactive oxygen species (ROS) were evaluated by a microplate reader or fluorescence microscopy with the CellROX® Green probe, and nitric oxide (NO) production was studied by fluorescence microscopy with the DAR4M-AM probe after acute or chronic treatment. Finally, immunoblotting analysis for endothelial nitric oxide synthase (eNOS) phosphorylation (p-eNOS) was performed. In BAE-1, IPA was not cytotoxic, except for the highest concentration (5 mM) after 48 h of treatment, and it showed neither oxidant nor antioxidant activity. However, the physiological concentration of IPA (1 μM) significantly reduced NO released by adenosine triphosphate (ATP)-stimulated BAE-1. These last data were confirmed by Western blot analysis, where IPA induced a significant reduction in p-eNOS in purinergic-stimulated BAE-1. Given these data, we can speculate that IPA negatively affects the physiological control of vascular tone by impairing the endothelial NO release induced by purinergic stimulation. These results represent a starting point for understanding the mechanisms underlying the relationship between gut microbiota metabolites and cardiometabolic health.
PMID:38542360 | DOI:10.3390/ijms25063389
GC-MS with Headspace Extraction for Non-Invasive Diagnostics of IBD Dynamics in a Model of DSS-Induced Colitis in Rats
Int J Mol Sci. 2024 Mar 14;25(6):3295. doi: 10.3390/ijms25063295.
ABSTRACT
Inflammatory bowel diseases are extremely common throughout the world. However, in most cases, it is asymptomatic at the initial stage. Therefore, it is important to develop non-invasive diagnostic methods that allow identification of the IBD risks in a timely manner. It is well known that gastrointestinal microbiota secrete volatile compounds (VOCs) and their composition may change in IBD. We propose a non-invasive method to identify the dynamics of IBD development in the acute and remission stage at the level of VOCs in model of dextran sulfate sodium (DSS) with chemically induced colitis measured by headspace GC/MS (HS GC/MS). Methods: VOCs profile was identified using a headspace GC/MS (HS GC/MS). GC/MS data were processed using MetaboAnalyst 5.0 and GraphPad Prism 8.0.1 software. The disease activity index (DAI) and histological method were used to assess intestinal inflammation. The peak of intestinal inflammation activity was reached on day 7, according to the disease activity index. Histological examination data showed changes in the intestine due to different stages of inflammation. As the acute inflammation stage was reached, the metabolomic profile also underwent changes, especially at the short-fatty acids level. A higher relative amounts of acetic acid (p value < 0.025) and lower relative amounts of propanoic acid (p value < 0.0005), butanoic acid (p value < 0.005) and phenol 4-methyl- (p value = 0.053) were observed in DSS7 group on day 7 compared to the control group. In remission stage, disease activity indexes decreased, and the histological picture also improved. But metabolome changes continued despite the withdrawal of the DSS examination. A lower relative amounts of propanoic acid (p value < 0.025), butanoic acid (p value < 0.0005), pentanoic acid (p value < 0.0005), and a significant de-crease of hexanoic acid (p value < 0.0005) relative amounts were observed in the DSS14 group compared to the control group on day 14. A model of DSS-induced colitis in rats was successfully implemented for metabolomic assessment of different stages of inflammation. We demonstrated that the ratios of volatile compounds change in response to DSS before the appearance of standard signs of inflammation, determined by DAI and histological examination. Changes in the volatile metabolome persisted even after visual intestine repair and it confirms the high sensitivity of the microbiota to the damaging effects of DSS. The use of HS GC/MS may be an important addition to existing methods for assessing inflammation at early stages.
PMID:38542269 | DOI:10.3390/ijms25063295
Phylogeographic Reconstruction to Trace the Source Population of Asian Giant Hornet Caught in Nanaimo in Canada and Blaine in the USA
Life (Basel). 2024 Feb 20;14(3):283. doi: 10.3390/life14030283.
ABSTRACT
The Asian giant hornet, Vespa mandarinia, is an invasive species that could potentially destroy the local honeybee industry in North America. It has been observed to nest in the coastal regions of British Columbia in Canada and Washington State in the USA. What is the source population of the immigrant hornets? The identification of the source population can shed light not only on the route of immigration but also on the similarity between the native habitat and the potential new habitat in the Pacific Northwest. We analyzed mitochondrial COX1 sequences of specimens sampled from multiple populations in China, the Republic of Korea, Japan, and the Russian Far East. V. mandarinia exhibits phylogeographic patterns, forming monophyletic clades for 16 specimens from China, six specimens from the Republic of Korea, and two specimens from Japan. The two mitochondrial COX1 sequences from Nanaimo, British Columbia, are identical to the two sequences from Japan. The COX1 sequence from Blaine, Washington State, clustered with those from the Republic of Korea and is identical to one sequence from the Republic of Korea. Our geophylogeny, which allows visualization of genetic variation over time and space, provides evolutionary insights on the evolution and speciation of three closely related vespine species (V. tropica, V. soror, and V. mandarinia), with the speciation events associated with the expansion of the distribution to the north.
PMID:38541609 | DOI:10.3390/life14030283
An Engineered Laccase from <em>Fomitiporia mediterranea</em> Accelerates Lignocellulose Degradation
Biomolecules. 2024 Mar 8;14(3):324. doi: 10.3390/biom14030324.
ABSTRACT
Laccases from white-rot fungi catalyze lignin depolymerization, a critical first step to upgrading lignin to valuable biodiesel fuels and chemicals. In this study, a wildtype laccase from the basidiomycete Fomitiporia mediterranea (Fom_lac) and a variant engineered to have a carbohydrate-binding module (Fom_CBM) were studied for their ability to catalyze cleavage of β-O-4' ether and C-C bonds in phenolic and non-phenolic lignin dimers using a nanostructure-initiator mass spectrometry-based assay. Fom_lac and Fom_CBM catalyze β-O-4' ether and C-C bond breaking, with higher activity under acidic conditions (pH < 6). The potential of Fom_lac and Fom_CBM to enhance saccharification yields from untreated and ionic liquid pretreated pine was also investigated. Adding Fom_CBM to mixtures of cellulases and hemicellulases improved sugar yields by 140% on untreated pine and 32% on cholinium lysinate pretreated pine when compared to the inclusion of Fom_lac to the same mixtures. Adding either Fom_lac or Fom_CBM to mixtures of cellulases and hemicellulases effectively accelerates enzymatic hydrolysis, demonstrating its potential applications for lignocellulose valorization. We postulate that additional increases in sugar yields for the Fom_CBM enzyme mixtures were due to Fom_CBM being brought more proximal to lignin through binding to either cellulose or lignin itself.
PMID:38540744 | DOI:10.3390/biom14030324
Evaluating Machine Learning Stability in Predicting Depression and Anxiety Amidst Subjective Response Errors
Healthcare (Basel). 2024 Mar 10;12(6):625. doi: 10.3390/healthcare12060625.
ABSTRACT
Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD) pose significant burdens on individuals and society, necessitating accurate prediction methods. Machine learning (ML) algorithms utilizing electronic health records and survey data offer promising tools for forecasting these conditions. However, potential bias and inaccuracies inherent in subjective survey responses can undermine the precision of such predictions. This research investigates the reliability of five prominent ML algorithms-a Convolutional Neural Network (CNN), Random Forest, XGBoost, Logistic Regression, and Naive Bayes-in predicting MDD and GAD. A dataset rich in biomedical, demographic, and self-reported survey information is used to assess the algorithms' performance under different levels of subjective response inaccuracies. These inaccuracies simulate scenarios with potential memory recall bias and subjective interpretations. While all algorithms demonstrate commendable accuracy with high-quality survey data, their performance diverges significantly when encountering erroneous or biased responses. Notably, the CNN exhibits superior resilience in this context, maintaining performance and even achieving enhanced accuracy, Cohen's kappa score, and positive precision for both MDD and GAD. This highlights the CNN's superior ability to handle data unreliability, making it a potentially advantageous choice for predicting mental health conditions based on self-reported data. These findings underscore the critical importance of algorithmic resilience in mental health prediction, particularly when relying on subjective data. They emphasize the need for careful algorithm selection in such contexts, with the CNN emerging as a promising candidate due to its robustness and improved performance under data uncertainties.
PMID:38540589 | DOI:10.3390/healthcare12060625
Transcriptomic Analysis of Postnatal Rat Carotid Body Development
Genes (Basel). 2024 Feb 27;15(3):302. doi: 10.3390/genes15030302.
ABSTRACT
The carotid body (CB), located bilaterally at the carotid artery bifurcations, is the primary sensory organ for monitoring arterial blood O2 levels. Carotid bodies are immature at birth, exhibiting low sensitivity to hypoxia, and become more sensitive with maturation during the first few weeks of neonatal life. To understand the molecular basis for the postnatal developmental hypoxic responses of CB, we isolated CBs from 5-day and 21-day-old Sprague-Dawley rats and performed RNA sequencing, which allows comprehensive analysis of gene expression. Differentially expressed genes (DEGs) were generated using Edge R, while functional enrichment analysis was performed using gene-set enrichment analysis (GSEA). Analysis of RNA-Seq data showed 2604 DEGs of the total 12,696 genes shared between neonates and adults. Of the 2604 DEGs, 924 genes were upregulated, and 1680 genes were downregulated. Further analysis showed that genes related to oxidative phosphorylation (Ox/phos) and hypoxia-signaling pathways were significantly upregulated in neonatal CBs compared to adult CBs, suggesting a possible link to differential developmental hypoxic responses seen in CB. Genes related to cytokine signaling (INFγ and TNFα) and transcription factors (CREB and NFΚB) mediated pathways were enriched in adult CBs, suggesting that expression of these pathways may be linked to developmental regulation. The RNA-Seq results were verified by analyzing mRNA changes in selected genes by qRT-PCR. Our results of enrichment analysis of biological pathways offer valuable insight into CB hypoxic sensing responses related to the development process.
PMID:38540361 | DOI:10.3390/genes15030302
Crohn's Disease and Ulcerative Colitis: From Pathophysiology to Novel Therapeutic Approaches
Biomedicines. 2024 Mar 19;12(3):689. doi: 10.3390/biomedicines12030689.
ABSTRACT
Inflammatory bowel disease (IBD) is a non-specific autoimmune condition impacting the gastrointestinal tract, encompassing Crohn's disease (CD) and ulcerative colitis (UC) [...].
PMID:38540302 | DOI:10.3390/biomedicines12030689
Beyond Pain Relief: Unveiling the Multifaceted Impact of Anti-CGRP/R mAbs on Comorbid Symptoms in Resistant Migraine Patients
Biomedicines. 2024 Mar 18;12(3):677. doi: 10.3390/biomedicines12030677.
ABSTRACT
The study aimed to evaluate the effects of monoclonal antibodies (mAbs) acting on the calcitonin gene-related peptide (CGRP) or its receptor (anti-CGRP/R mAbs) on migraine comorbidities of depression, anxiety, and fatigue in patients resistant to traditional therapies. The issue addressed in this study is pivotal to unveiling the role of this neurotransmitter beyond pain processing. We conducted an open-label prospective study assessing comorbidities in patients with high frequency (HFEM) and chronic migraine (CM), medication overuse headache (MOH), and resistance to traditional prophylaxis. All patients were treated with anti-CGRP/R mAbs for 3 months. Seventy-seven patients were enrolled with either HFEM (21%) or CM (79%) with or without MOH (56% and 44%, respectively). We identified 21 non-responders (27%) and 56 responders (73%), defined on the reduction ≥50% of headache frequency. The two groups were highly homogeneous for the investigated comorbidities. Disease severity in terms of headache frequency, migraine-related disability, and affective comorbid symptoms was reduced in both groups with different thresholds; allodynia and fatigue were ameliorated only in responders. We found that anti-CGRP/R antibodies improved pain together with affection, fatigue, and sensory sensitization in a cohort of migraine patients resistant to traditional prophylaxis. Our results offer novel perspectives on the early efficacy of anti-CGRP/R mAbs in difficult-to-treat patients focusing on clinical features other than pain relief.
PMID:38540290 | DOI:10.3390/biomedicines12030677
MicroRNAs and Their Associated Genes Regulating the Acrosome Reaction in Sperm of High- versus Low-Fertility Holstein Bulls
Animals (Basel). 2024 Mar 8;14(6):833. doi: 10.3390/ani14060833.
ABSTRACT
Bioinformatics envisage experimental data as illustrated biological networks, exploring roles of individual proteins and their interactions with other proteins in regulation of biological functions. The objective was to identify differentially expressed miRNAs and their associated genes regulating the acrosome reaction in capacitated sperm of high- compared to low-fertility dairy bulls and to elucidate biological functional pathways using a systems biology approach, featuring miRNA-mRNA cluster analysis. Categorized bovine-specific miRNAs (n = 84) were analyzed by RT-PCR; 19 were differentially expressed in high- compared to low-fertility sperm (p ≤ 0.05, fold regulation ≥ 2 magnitudes). Six miRNAs (bta-miR-129-5p, bta-miR-193a-3p, bta-miR-217, bta-mir-296-5p, bta-miR-27a, and bta-miR-320a) were highly upregulated (p < 0.05; fold regulation ≥ 5 magnitudes) in high- compared to low-fertility sperm. Highly scored integrated genes of differentially expressed miRNAs predicted associations with pathways regulating acrosome vesicle exocytosis, acrosome reaction, and sperm-oocyte binding. The mRNA expressions of genes associated with the acrosome reaction (including hub genes) were greater, ranging from 2.0 to 9.1-fold (p < 0.05) in high- compared to low-fertility capacitated bull sperm. In conclusion, differentially expressed miRNAs in high-fertility bovine sperm regulating acrosome functions have potential for predicting bull fertility.
PMID:38539931 | DOI:10.3390/ani14060833
Nucleoredoxin Redox Interactions Are Sensitized by Aging and Potentiated by Chronic Alcohol Consumption in the Mouse Liver
Antioxidants (Basel). 2024 Feb 20;13(3):257. doi: 10.3390/antiox13030257.
ABSTRACT
Aging is characterized by increased reactive species, leading to redox imbalance, oxidative damage, and senescence. The adverse effects of alcohol consumption potentiate aging-associated alterations, promoting several diseases, including liver diseases. Nucleoredoxin (NXN) is a redox-sensitive enzyme that targets reactive oxygen species and regulates key cellular processes through redox protein-protein interactions. Here, we determine the effect of chronic alcohol consumption on NXN-dependent redox interactions in the liver of aged mice. We found that chronic alcohol consumption preferentially promotes the localization of NXN either into or alongside senescent cells, declines its interacting capability, and worsens the altered interaction ratio of NXN with FLII, MYD88, CAMK2A, and PFK1 proteins induced by aging. In addition, carbonylated protein and cell proliferation increased, and the ratios of collagen I and collagen III were inverted. Thus, we demonstrate an emerging phenomenon associated with altered redox homeostasis during aging, as shown by the declining capability of NXN to interact with partner proteins, which is enhanced by chronic alcohol consumption in the mouse liver. This evidence opens an attractive window to elucidate the consequences of both aging and chronic alcohol consumption on the downstream signaling pathways regulated by NXN-dependent redox-sensitive interactions.
PMID:38539791 | DOI:10.3390/antiox13030257
Regulation of PD-L1 Expression by YY1 in Cancer: Therapeutic Efficacy of Targeting YY1
Cancers (Basel). 2024 Mar 21;16(6):1237. doi: 10.3390/cancers16061237.
ABSTRACT
During the last decade, we have witnessed several milestones in the treatment of various resistant cancers including immunotherapeutic strategies that have proven to be superior to conventional treatment options, such as chemotherapy and radiation. This approach utilizes the host's immune response, which is triggered by cancer cells expressing tumor-associated antigens or neoantigens. The responsive immune cytotoxic CD8+ T cells specifically target and kill tumor cells, leading to tumor regression and prolongation of survival in some cancers; however, some cancers may exhibit resistance due to the inactivation of anti-tumor CD8+ T cells. One mechanism by which the anti-tumor CD8+ T cells become dysfunctional is through the activation of the inhibitory receptor programmed death-1 (PD-1) by the corresponding tumor cells (or other cells in the tumor microenvironment (TME)) that express the programmed death ligand-1 (PD-L1). Hence, blocking the PD-1/PD-L1 interaction via specific monoclonal antibodies (mAbs) restores the CD8+ T cells' functions, leading to tumor regression. Accordingly, the Food and Drug Administration (FDA) has approved several checkpoint antibodies which act as immune checkpoint inhibitors. Their clinical use in various resistant cancers, such as metastatic melanoma and non-small-cell lung cancer (NSCLC), has shown significant clinical responses. We have investigated an alternative approach to prevent the expression of PD-L1 on tumor cells, through targeting the oncogenic transcription factor Yin Yang 1 (YY1), a known factor overexpressed in many cancers. We report the regulation of PD-L1 by YY1 at the transcriptional, post-transcriptional, and post-translational levels, resulting in the restoration of CD8+ T cells' anti-tumor functions. We have performed bioinformatic analyses to further explore the relationship between both YY1 and PD-L1 in cancer and to corroborate these findings. In addition to its regulation of PD-L1, YY1 has several other anti-cancer activities, such as the regulation of proliferation and cell viability, invasion, epithelial-mesenchymal transition (EMT), metastasis, and chemo-immuno-resistance. Thus, targeting YY1 will have a multitude of anti-tumor activities resulting in a significant obliteration of cancer oncogenic activities. Various strategies are proposed to selectively target YY1 in human cancers and present a promising novel therapeutic approach for treating unresponsive cancer phenotypes. These findings underscore the distinct regulatory roles of YY1 and PD-L1 (CD274) in cancer progression and therapeutic response.
PMID:38539569 | DOI:10.3390/cancers16061237
Lung Cancer Proteogenomics: Shaping the Future of Clinical Investigation
Cancers (Basel). 2024 Mar 21;16(6):1236. doi: 10.3390/cancers16061236.
ABSTRACT
BACKGROUND: Lung cancer is associated with a high incidence of mortality worldwide. Molecular mechanisms governing the disease have been explored by genomic studies; however, several aspects remain elusive. The integration of genomic profiling with in-depth proteomic profiling has introduced a new dimension to lung cancer research, termed proteogenomics. The aim of this review article was to investigate proteogenomic approaches in lung cancer, focusing on how elucidation of proteogenomic features can evoke tangible clinical outcomes.
METHODS: A strict methodological approach was adopted for study selection and key article features included molecular attributes, tumor biomarkers, and major hallmarks involved in oncogenesis.
RESULTS: As a consensus, in all studies it becomes evident that proteogenomics is anticipated to fill significant knowledge gaps and assist in the discovery of novel treatment options. Genomic profiling unravels patient driver mutations, and exploration of downstream effects uncovers great variability in transcript and protein correlation. Also, emphasis is placed on defining proteogenomic traits of tumors of major histological classes, generating a diverse portrait of predictive markers and druggable targets.
CONCLUSIONS: An up-to-date synthesis of landmark lung cancer proteogenomic studies is herein provided, underpinning the importance of proteogenomics in the landscape of personalized medicine for combating lung cancer.
PMID:38539567 | DOI:10.3390/cancers16061236
Multimodal, Technology-Assisted Intervention for the Management of Menopause after Cancer Improves Cancer-Related Quality of Life-Results from the Menopause after Cancer (Mac) Study
Cancers (Basel). 2024 Mar 12;16(6):1127. doi: 10.3390/cancers16061127.
ABSTRACT
BACKGROUND: Vasomotor symptoms (VMSs) associated with menopause represent a significant challenge for many patients after cancer treatment, particularly if conventional menopausal hormone therapy (MHT) is contraindicated.
METHODS: The Menopause after Cancer (MAC) Study (NCT04766229) was a single-arm phase II trial examining the impact of a composite intervention consisting of (1) the use of non-hormonal pharmacotherapy to manage VMS, (2) digital cognitive behavioral therapy for insomnia (dCBT-I) using Sleepio (Big Health), (3) self-management strategies for VMS delivered via the myPatientSpace mobile application and (4) nomination of an additional support person/partner on quality of life (QoL) in women with moderate-to-severe VMS after cancer. The primary outcome was a change in cancer-specific global QoL assessed by the EORTC QLC C-30 v3 at 6 months. Secondary outcomes included the frequency of VMS, the bother/interference of VMS and insomnia symptoms.
RESULTS: In total, 204 women (82% previous breast cancer) with a median age of 49 years (range 28-66) were recruited. A total of 120 women completed the protocol. Global QoL scores increased from 62.2 (95%CI 58.6-65.4) to 70.4 (95%CI 67.1-73.8) at 6 months (p < 0.001) in the intention to treatment (ITT) cohort (n = 204) and from 62 (95%CI 58.6-65.4) to 70.4 (95%CI 67.1-73.8) at 6 months (p < 0.001) in the per-protocol (PP) cohort (n = 120). At least 50% reductions were noticed in the frequency of VMS as well as the degree of bother/interference of VMS at six months. The prevalence of insomnia reduced from 93.1% at the baseline to 45.2% at 6 months (p < 0.001). The Sleep Condition Indicator increased from 8.5 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.0005) in the ITT cohort and 7.9 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.001) in the PP cohort.
CONCLUSIONS: A targeted composite intervention improves the quality of life for cancer patients with frequent and bothersome vasomotor symptoms with additional benefits on frequency, the bother/interference of VMS and insomnia symptoms.
PMID:38539462 | DOI:10.3390/cancers16061127
Systematic immune cell dysregulation and molecular subtypes revealed by single-cell RNA-seq of subjects with type 1 diabetes
Genome Med. 2024 Mar 27;16(1):45. doi: 10.1186/s13073-024-01300-z.
ABSTRACT
BACKGROUND: Type 1 diabetes mellitus (T1DM) is a prototypic endocrine autoimmune disease resulting from an immune-mediated destruction of pancreatic insulin-secreting β cells. A comprehensive immune cell phenotype evaluation in T1DM has not been performed thus far at the single-cell level.
METHODS: In this cross-sectional analysis, we generated a single-cell transcriptomic dataset of peripheral blood mononuclear cells (PBMCs) from 46 manifest T1DM (stage 3) cases and 31 matched controls.
RESULTS: We surprisingly detected profound alterations in circulatory immune cells (1784 dysregulated genes in 13 immune cell types), far exceeding the count in the comparator systemic autoimmune disease SLE. Genes upregulated in T1DM were involved in WNT signaling, interferon signaling and migration of T/NK cells, antigen presentation by B cells, and monocyte activation. A significant fraction of these differentially expressed genes were also altered in T1DM pancreatic islets. We used the single-cell data to construct a T1DM metagene z-score (TMZ score) that distinguished cases and controls and classified patients into molecular subtypes. This score correlated with known prognostic immune markers of T1DM, as well as with drug response in clinical trials.
CONCLUSIONS: Our study reveals a surprisingly strong systemic dimension at the level of immune cell network in T1DM, defines disease-relevant molecular subtypes, and has the potential to guide non-invasive test development and patient stratification.
PMID:38539228 | DOI:10.1186/s13073-024-01300-z
Calorie restriction-induced leptin reduction and T-lymphocyte activation in blood and adipose tissue in men with overweight and obesity
Int J Obes (Lond). 2024 Mar 27. doi: 10.1038/s41366-024-01513-7. Online ahead of print.
ABSTRACT
BACKGROUND: T-Lymphocyte activation is modulated by the adipokine leptin and serum concentrations of this hormone can be reduced with short-term calorie restriction. The aim of this study was to understand whether leptin per se is important in determining levels of T-lymphocyte activation in humans, by investigating whether the reduction in leptin concentration following calorie restriction is associated with a decrease in T-Lymphocyte activation in blood and adipose tissue.
METHODS: Twelve men with overweight and obesity (age 35-55 years, waist circumference 95-115 cm) reduced their calorie intake by 50% for 3 consecutive days. Blood and subcutaneous adipose tissue were obtained for isolation of immune cells and cytokine analysis. CD4+ and CD8 + T-Lymphocytes were identified and characterised according to their expression of activation markers CD25 and CD69 by flow cytometry.
RESULTS: Serum leptin was reduced by (mean ± SEM) 31 ± 16% (p < 0.001) following calorie restriction. The percentage of blood CD4 + CD25 + T-lymphocytes and level of CD25 expression on these lymphocytes were significantly reduced by 8 ± 10% (p = 0.016) and 8 ± 4% (p = 0.058), respectively. After calorie restriction, ex vivo leptin secretion from abdominal subcutaneous adipose tissue explants was not changed, and this corresponded with a lack of change in adipose tissue resident T-Lymphocyte activation.
CONCLUSIONS: Serum leptin was reduced after calorie restriction and this was temporally associated with a reduction in activation of blood CD4 + CD25 + T-Lymphocytes. In abdominal subcutaneous adipose tissue, however, leptin secretion was unaltered, and there were no observed changes in adipose resident T-Lymphocyte activation.
PMID:38538853 | DOI:10.1038/s41366-024-01513-7
Targeting DCAF5 suppresses SMARCB1-mutant cancer by stabilizing SWI/SNF
Nature. 2024 Mar 27. doi: 10.1038/s41586-024-07250-1. Online ahead of print.
ABSTRACT
Whereas oncogenes can potentially be inhibited with small molecules, the loss of tumour suppressors is more common and is problematic because the tumour-suppressor proteins are no longer present to be targeted. Notable examples include SMARCB1-mutant cancers, which are highly lethal malignancies driven by the inactivation of a subunit of SWI/SNF (also known as BAF) chromatin-remodelling complexes. Here, to generate mechanistic insights into the consequences of SMARCB1 mutation and to identify vulnerabilities, we contributed 14 SMARCB1-mutant cell lines to a near genome-wide CRISPR screen as part of the Cancer Dependency Map Project1-3. We report that the little-studied gene DDB1-CUL4-associated factor 5 (DCAF5) is required for the survival of SMARCB1-mutant cancers. We show that DCAF5 has a quality-control function for SWI/SNF complexes and promotes the degradation of incompletely assembled SWI/SNF complexes in the absence of SMARCB1. After depletion of DCAF5, SMARCB1-deficient SWI/SNF complexes reaccumulate, bind to target loci and restore SWI/SNF-mediated gene expression to levels that are sufficient to reverse the cancer state, including in vivo. Consequently, cancer results not from the loss of SMARCB1 function per se, but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of ubiquitin-mediated quality-control factors may effectively reverse the malignant state of some cancers driven by disruption of tumour suppressor complexes.
PMID:38538798 | DOI:10.1038/s41586-024-07250-1
Single-cell multiplex chromatin and RNA interactions in ageing human brain
Nature. 2024 Mar 27. doi: 10.1038/s41586-024-07239-w. Online ahead of print.
ABSTRACT
Dynamically organized chromatin complexes often involve multiplex chromatin interactions and sometimes chromatin-associated RNA1-3. Chromatin complex compositions change during cellular differentiation and ageing, and are expected to be highly heterogeneous among terminally differentiated single cells4-7. Here we introduce the multinucleic acid interaction mapping in single cells (MUSIC) technique for concurrent profiling of multiplex chromatin interactions, gene expression and RNA-chromatin associations within individual nuclei. When applied to 14 human frontal cortex samples from older donors, MUSIC delineated diverse cortical cell types and states. We observed that nuclei exhibiting fewer short-range chromatin interactions were correlated with both an 'older' transcriptomic signature and Alzheimer's disease pathology. Furthermore, the cell type exhibiting chromatin contacts between cis expression quantitative trait loci and a promoter tends to be that in which these cis expression quantitative trait loci specifically affect the expression of their target gene. In addition, female cortical cells exhibit highly heterogeneous interactions between XIST non-coding RNA and chromosome X, along with diverse spatial organizations of the X chromosomes. MUSIC presents a potent tool for exploration of chromatin architecture and transcription at cellular resolution in complex tissues.
PMID:38538789 | DOI:10.1038/s41586-024-07239-w
ROCK1 inhibition improves wound healing in diabetes via RIPK4/AMPK pathway
Acta Pharmacol Sin. 2024 Mar 27. doi: 10.1038/s41401-024-01246-3. Online ahead of print.
ABSTRACT
Refractory wounds are a severe complication of diabetes mellitus that often leads to amputation because of the lack of effective treatments and therapeutic targets. The pathogenesis of refractory wounds is complex, involving many types of cells. Rho-associated protein kinase-1 (ROCK1) phosphorylates a series of substrates that trigger downstream signaling pathways, affecting multiple cellular processes, including cell migration, communication, and proliferation. The present study investigated the role of ROCK1 in diabetic wound healing and molecular mechanisms. Our results showed that ROCK1 expression significantly increased in wound granulation tissues in diabetic patients, streptozotocin (STZ)-induced diabetic mice, and db/db diabetic mice. Wound healing and blood perfusion were dose-dependently improved by the ROCK1 inhibitor fasudil in diabetic mice. In endothelial cells, fasudil and ROCK1 siRNA significantly elevated the phosphorylation of adenosine monophosphate-activated protein kinase at Thr172 (pThr172-AMPKα), the activity of endothelial nitric oxide synthase (eNOS), and suppressed the levels of mitochondrial reactive oxygen species (mtROS) and nitrotyrosine formation. Experiments using integrated bioinformatics analysis and coimmunoprecipitation established that ROCK1 inhibited pThr172-AMPKα by binding to receptor-interacting serine/threonine kinase 4 (RIPK4). These results suggest that fasudil accelerated wound repair and improved angiogenesis at least partially through the ROCK1/RIPK4/AMPK pathway. Fasudil may be a potential treatment for refractory wounds in diabetic patients.
PMID:38538716 | DOI:10.1038/s41401-024-01246-3
Roadmap for the next decade of plant programmed cell death research
New Phytol. 2024 Mar 27. doi: 10.1111/nph.19709. Online ahead of print.
ABSTRACT
Programmed cell death (PCD) is fundamentally important for plant development, abiotic stress responses and immunity, but our understanding of its regulation remains fragmented. Building a stronger research community is required to accelerate progress in this area through knowledge exchange and constructive debate. In this Viewpoint, we aim to initiate a collective effort to integrate data across a diverse set of experimental models to facilitate characterisation of the fundamental mechanisms underlying plant PCD and ultimately aid the development of a new plant cell death classification system in the future. We also put forward our vision for the next decade of plant PCD research stemming from discussions held during the 31st New Phytologist workshop, 'The Life and Death Decisions of Plant Cells' that took place at University College Dublin in Ireland (14-15 June 2023). We convey the key areas of significant progress and possible future research directions identified, including resolving the spatiotemporal control of cell death, isolation of its molecular and genetic regulators, and harnessing technical advances for studying PCD events in plants. Further, we review the breadth of potential impacts of plant PCD research and highlight the promising new applications of findings from this dynamically evolving field.
PMID:38538552 | DOI:10.1111/nph.19709
SpectiCal: <em>m</em>/<em>z</em> Calibration of MS2 Peptide Spectra Using Known Low Mass Ions
J Proteome Res. 2024 Mar 27. doi: 10.1021/acs.jproteome.3c00882. Online ahead of print.
ABSTRACT
Most tandem mass spectrometry fragmentation spectra have small calibration errors that can lead to suboptimal interpretation and annotation. We developed SpectiCal, a software tool that can read mzML files from data-dependent acquisition proteomics experiments in parallel, compute m/z calibrations for each file prior to identification analysis based on known low-mass ions, and produce information about frequently observed peaks and their explanations. Using calibration coefficients, the data can be corrected to generate new calibrated mzML files. SpectiCal was tested using five public data sets, creating a table of commonly observed low-mass ions and their identifications. Information about the calibration and individual peaks is written in PDF and TSV files. This includes information for each peak, such as the number of runs in which it appears, the percentage of spectra in which it appears, and a plot of the aggregated region surrounding each peak. SpectiCal can be used to compute MS run calibrations, examine MS runs for artifacts that might hinder downstream analysis, and generate tables of detected low-mass ions for further analysis. SpectiCal is freely available at https://github.com/PlantProteomes/SpectiCal.
PMID:38538550 | DOI:10.1021/acs.jproteome.3c00882