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1.
Cell Host Microbe ; 32(4): 573-587.e5, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38569545

RESUMEN

Microbiota assembly in the infant gut is influenced by diet. Breastfeeding and human breastmilk oligosaccharides promote the colonization of beneficial bifidobacteria. Infant formulas are supplemented with bifidobacteria or complex oligosaccharides, notably galacto-oligosaccharides (GOS), to mimic breast milk. To compare microbiota development across feeding modes, this randomized controlled intervention study (German Clinical Trial DRKS00012313) longitudinally sampled infant stool during the first year of life, revealing similar fecal bacterial communities between formula- and breast-fed infants (N = 210) but differences across age. Infant formula containing GOS sustained high levels of bifidobacteria compared with formula containing B. longum and B. breve or placebo. Metabolite and bacterial profiling revealed 24-h oscillations and circadian networks. Rhythmicity in bacterial diversity, specific taxa, and functional pathways increased with age and was strongest following breastfeeding and GOS supplementation. Circadian rhythms in dominant taxa were further maintained ex vivo in a chemostat model. Hence, microbiota rhythmicity develops early in life and is impacted by diet.


Asunto(s)
Fórmulas Infantiles , Microbiota , Lactante , Femenino , Humanos , Fórmulas Infantiles/microbiología , Lactancia Materna , Leche Humana , Bifidobacterium , Heces/microbiología , Oligosacáridos/metabolismo , Ritmo Circadiano
2.
Bioinform Adv ; 4(1): vbae032, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38464974

RESUMEN

Summary: Transcriptome deconvolution has emerged as a reliable technique to estimate cell-type abundances from bulk RNA sequencing data. Unlike their human equivalents, methods to quantify the cellular composition of complex tissues from murine transcriptomics are sparse and sometimes not easy to use. We extended the immunedeconv R package to facilitate the deconvolution of mouse transcriptomics, enabling the quantification of murine immune-cell types using 13 different methods. Through immunedeconv, we further offer the possibility of tweaking cell signatures used by deconvolution methods, providing custom annotations tailored for specific cell types and tissues. These developments strongly facilitate the study of the immune-cell composition of mouse models and further open new avenues in the investigation of the cellular composition of other tissues and organisms. Availability and implementation: The R package and the documentation are available at https://github.com/omnideconv/immunedeconv.

3.
Front Immunol ; 15: 1340726, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38504984

RESUMEN

Encoded by PTPN11, the Src-homology 2 domain-containing phosphatase 2 (SHP2) integrates signals from various membrane-bound receptors such as receptor tyrosine kinases (RTKs), cytokine and integrin receptors and thereby promotes cell survival and proliferation. Activating mutations in the PTPN11 gene may trigger signaling pathways leading to the development of hematological malignancies, but are rarely found in solid tumors. Yet, aberrant SHP2 expression or activation has implications in the development, progression and metastasis of many solid tumor entities. SHP2 is involved in multiple signaling cascades, including the RAS-RAF-MEK-ERK-, PI3K-AKT-, JAK-STAT- and PD-L1/PD-1- pathways. Although not mutated, activation or functional requirement of SHP2 appears to play a relevant and context-dependent dichotomous role. This mostly tumor-promoting and infrequently tumor-suppressive role exists in many cancers such as gastrointestinal tumors, pancreatic, liver and lung cancer, gynecological entities, head and neck cancers, prostate cancer, glioblastoma and melanoma. Recent studies have identified SHP2 as a potential biomarker for the prognosis of some solid tumors. Based on promising preclinical work and the advent of orally available allosteric SHP2-inhibitors early clinical trials are currently investigating SHP2-directed approaches in various solid tumors, either as a single agent or in combination regimes. We here provide a brief overview of the molecular functions of SHP2 and collate current knowledge with regard to the significance of SHP2 expression and function in different solid tumor entities, including cells in their microenvironment, immune escape and therapy resistance. In the context of the present landscape of clinical trials with allosteric SHP2-inhibitors we discuss the multitude of opportunities but also limitations of a strategy targeting this non-receptor protein tyrosine phosphatase for treatment of solid tumors.


Asunto(s)
Neoplasias Pulmonares , Fosfatidilinositol 3-Quinasas , Masculino , Humanos , Transducción de Señal , Mutación con Ganancia de Función , Tirosina , Microambiente Tumoral , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética
4.
Sci Rep ; 14(1): 2808, 2024 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-38307916

RESUMEN

Bulk RNA sequencing (RNA-seq) of blood is typically used for gene expression analysis in biomedical research but is still rarely used in clinical practice. In this study, we propose that RNA-seq should be considered a diagnostic tool, as it offers not only insights into aberrant gene expression and splicing but also delivers additional readouts on immune cell type composition as well as B-cell and T-cell receptor (BCR/TCR) repertoires. We demonstrate that RNA-seq offers insights into a patient's immune status via integrative analysis of RNA-seq data from patients infected with various SARS-CoV-2 variants (in total 196 samples with up to 200 million reads sequencing depth). We compare the results of computational cell-type deconvolution methods (e.g., MCP-counter, xCell, EPIC, quanTIseq) to complete blood count data, the current gold standard in clinical practice. We observe varying levels of lymphocyte depletion and significant differences in neutrophil levels between SARS-CoV-2 variants. Additionally, we identify B and T cell receptor (BCR/TCR) sequences using the tools MiXCR and TRUST4 to show that-combined with sequence alignments and BLASTp-they could be used to classify a patient's disease. Finally, we investigated the sequencing depth required for such analyses and concluded that 10 million reads per sample is sufficient. In conclusion, our study reveals that computational cell-type deconvolution and BCR/TCR methods using bulk RNA-seq analyses can supplement missing CBC data and offer insights into immune responses, disease severity, and pathogen-specific immunity, all achievable with a sequencing depth of 10 million reads per sample.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/genética , Perfilación de la Expresión Génica , Receptores de Antígenos de Linfocitos T/genética , Análisis de Secuencia de ARN/métodos , Inmunidad
5.
bioRxiv ; 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-38076885

RESUMEN

Bulk RNA sequencing (RNA-seq) of blood is typically used for gene expression analysis in biomedical research but is still rarely used in clinical practice. In this study, we argue that RNA-seq should be considered a routine diagnostic tool, as it offers not only insights into aberrant gene expression and splicing but also delivers additional readouts on immune cell type composition as well as B-cell and T-cell receptor (BCR/TCR) repertoires. We demonstrate that RNA-seq offers vital insights into a patient's immune status via integrative analysis of RNA-seq data from patients infected with various SARS-CoV-2 variants (in total 240 samples with up to 200 million reads sequencing depth). We compare the results of computational cell-type deconvolution methods (e.g., MCP-counter, xCell, EPIC, quanTIseq) to complete blood count data, the current gold standard in clinical practice. We observe varying levels of lymphocyte depletion and significant differences in neutrophil levels between SARS-CoV-2 variants. Additionally, we identify B and T cell receptor (BCR/TCR) sequences using the tools MiXCR and TRUST4 to show that - combined with sequence alignments and pBLAST - they could be used to classify a patient's disease. Finally, we investigated the sequencing depth required for such analyses and concluded that 10 million reads per sample is sufficient. In conclusion, our study reveals that computational cell-type deconvolution and BCR/TCR methods using bulk RNA-seq analyses can supplement missing CBC data and offer insights into immune responses, disease severity, and pathogen-specific immunity, all achievable with a sequencing depth of 10 million reads per sample.

6.
NAR Genom Bioinform ; 5(2): lqad044, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37260511

RESUMEN

Alternative splicing is a major contributor to transcriptome and proteome diversity in health and disease. A plethora of tools have been developed for studying alternative splicing in RNA-seq data. Previous benchmarks focused on isoform quantification and mapping. They neglected event detection tools, which arguably provide the most detailed insights into the alternative splicing process. DICAST offers a modular and extensible framework for analysing alternative splicing integrating eleven splice-aware mapping and eight event detection tools. We benchmark all tools extensively on simulated as well as whole blood RNA-seq data. STAR and HISAT2 demonstrated the best balance between performance and run time. The performance of event detection tools varies widely with no tool outperforming all others. DICAST allows researchers to employ a consensus approach to consider the most successful tools jointly for robust event detection. Furthermore, we propose the first reporting standard to unify existing formats and to guide future tool development.

7.
Arterioscler Thromb Vasc Biol ; 43(8): 1494-1509, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37381987

RESUMEN

BACKGROUND: MAGT1 (magnesium transporter 1) is a subunit of the oligosaccharide protein complex with thiol-disulfide oxidoreductase activity, supporting the process of N-glycosylation. MAGT1 deficiency was detected in human patients with X-linked immunodeficiency with magnesium defect syndrome and congenital disorders of glycosylation, resulting in decreased cation responses in lymphocytes, thereby inhibiting the immune response against viral infections. Curative hematopoietic stem cell transplantation of patients with X-linked immunodeficiency with magnesium defect causes fatal bleeding and thrombotic complications. METHODS: We studied the role of MAGT1 deficiency in platelet function in relation to arterial thrombosis and hemostasis using several in vitro experimental settings and in vivo models of arterial thrombosis and transient middle cerebral artery occlusion model of ischemic stroke. RESULTS: MAGT1-deficient mice (Magt1-/y) displayed accelerated occlusive arterial thrombus formation in vivo, a shortened bleeding time, and profound brain damage upon focal cerebral ischemia. These defects resulted in increased calcium influx and enhanced second wave mediator release, which further reinforced platelet reactivity and aggregation responses. Supplementation of MgCl2 or pharmacological blockade of TRPC6 (transient receptor potential cation channel, subfamily C, member 6) channel, but not inhibition of store-operated calcium entry, normalized the aggregation responses of Magt1-/y platelets to the control level. GP (glycoprotein) VI activation of Magt1-/y platelets resulted in hyperphosphorylation of Syk (spleen tyrosine kinase), LAT (linker for activation of T cells), and PLC (phospholipase C) γ2, whereas the inhibitory loop regulated by PKC (protein kinase C) was impaired. A hyperaggregation response to the GPVI agonist was confirmed in human platelets isolated from a MAGT1-deficient (X-linked immunodeficiency with magnesium defect) patient. Haploinsufficiency of TRPC6 in Magt1-/y mice could normalize GPVI signaling, platelet aggregation, and thrombus formation in vivo. CONCLUSIONS: These results suggest that MAGT1 and TRPC6 are functionally linked. Therefore, deficiency or impaired functionality of MAGT1 could be a potential risk factor for arterial thrombosis and stroke.


Asunto(s)
Proteínas de Transporte de Catión , Homeostasis , Infarto de la Arteria Cerebral Media , Accidente Cerebrovascular Isquémico , Trombosis , Animales , Humanos , Ratones , Plaquetas/metabolismo , Calcio/metabolismo , Cationes/metabolismo , Accidente Cerebrovascular Isquémico/genética , Accidente Cerebrovascular Isquémico/complicaciones , Accidente Cerebrovascular Isquémico/metabolismo , Magnesio/metabolismo , Activación Plaquetaria , Agregación Plaquetaria , Glicoproteínas de Membrana Plaquetaria/metabolismo , Trombosis/genética , Trombosis/metabolismo , Canal Catiónico TRPC6/metabolismo , Proteínas de Transporte de Catión/deficiencia
8.
MAbs ; 15(1): 2215887, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37312434

RESUMEN

Upon reformatting of an antibody to single-chain variable fragment format, a region in the former variable/constant domain interface of the heavy chain becomes accessible for preexisting (PE) anti-drug antibody (ADA) binding. The region exposed because of this reformatting contains a previously hidden hydrophobic patch. In this study, mutations are introduced in this region to reduce PE ADA reactivity and concomitantly reduce the hydrophobic patch. To enhance our understanding of the importance of individual residues in this region with respect to PE ADA reactivity, a total of 50 molecules for each of two antibodies against different tumor-associated antigens were designed, produced, and characterized by an arsenal of biophysical methods. The aim was to identify suitable mutations that reduce, or completely eliminate, PE ADA reactivity to variable fragments, without compromising biophysical and pharmacodynamic properties. Computational methods were used to pinpoint key residues to mutate and to evaluate designed molecules in silico, in order to reduce the number of molecules to produce and characterize experimentally. Mutation of two threonine residues, Thr101 and Thr146 in the variable heavy domain, proved to be critical to eliminate PE ADA reactivity. This may have important implications in optimizing early drug development for antibody fragment-based therapeutics.


Asunto(s)
Desarrollo de Medicamentos , Anticuerpos de Cadena Única , Mutación , Anticuerpos de Cadena Única/genética
10.
Am J Respir Cell Mol Biol ; 68(3): 314-325, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36378826

RESUMEN

TRPA1 (transient receptor potential ankyrin 1) is a nonselective Ca2+-permeable cation channel, which was originally cloned from human lung fibroblasts (HLFs). TRPA1-mediated Ca2+ entry is evoked by exposure to several chemicals, including allyl isothiocyanate (AITC), and a protective effect of TRPA1 activation in the development of cardiac fibrosis has been proposed. Yet the function of TRPA1 in TGF-ß1 (transforming growth factor-ß1)-driven fibroblast-to-myofibroblast differentiation and the development of pulmonary fibrosis remains elusive. TRPA1 expression and function were analyzed in cultured primary HLFs, and mRNA concentrations were significantly reduced after adding TGF-ß1. Expression of genes encoding fibrosis markers (e.g., ACTA2, SERPINE1 [plasminogen activator inhibitor 1], FN1 [fibronectin], COL1A1 [type I collagen]) was increased after siRNA-mediated downregulation of TRPA1 mRNA in HLFs. Moreover, AITC-induced Ca2+ entry in HLFs was decreased after TGF-ß1 treatment and by application of TRPA1 siRNAs, while AITC treatment alone did not reduce cell viability or enhance apoptosis. Most interestingly, AITC-induced TRPA1 activation augmented ERK1/2 (extracellular signal-regulated kinase 1/2) and SMAD2 linker phosphorylation, which might inhibit TGF-ß-receptor signaling. Our results suggest an inhibitory function of TRPA1 channels in TGF-ß1-driven fibroblast-to-myofibroblast differentiation. Therefore, activation of TRPA1 channels might be protective during the development of pulmonary fibrosis in patients.


Asunto(s)
Fibrosis Pulmonar , Factor de Crecimiento Transformador beta1 , Humanos , Factor de Crecimiento Transformador beta1/metabolismo , Fibrosis Pulmonar/patología , Miofibroblastos/metabolismo , Fibroblastos/metabolismo , Diferenciación Celular/fisiología , Fibrosis , ARN Mensajero/genética , Células Cultivadas , Canal Catiónico TRPA1/metabolismo
11.
Cell Calcium ; 109: 102674, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36450202

RESUMEN

Transient Receptor Potential (TRP) channels are nonselective cation channels, which are mainly permeable to Ca2+ and Na+ but many of them are also permeable to Zn2+. In a new elegant study, a Zn2+-dependent pathway involving the TRP member TRPC6 and α1- as well as ß-adrenoceptors (AR) was dissected in rodent myocytes. Norepinephrine-mediated activation of α1-AR induces Zn2+ influx through TRPC6 channels, which reinforces ß-AR-mediated positive inotropy and may help patients with heart failure. This work encourages a closer look at the consequences of Zn2+ permeation through TRP channels in human health and disease.


Asunto(s)
Miocardio , Canal Catiónico TRPC6 , Humanos , Cationes , Miocardio/metabolismo , Canales Catiónicos TRPC/metabolismo , Canal Catiónico TRPC6/metabolismo , Zinc/metabolismo , Calcio/metabolismo , Roedores , Animales
12.
Front Physiol ; 13: 1080875, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36569761

RESUMEN

Chronic hypoxia-induced pulmonary hypertension (CHPH) is a severe disease that is characterized by increased proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) leading to pulmonary vascular remodeling. The resulting increase in pulmonary vascular resistance (PVR) causes right ventricular hypertrophy and ultimately right heart failure. In addition, increased PVR can also be a consequence of hypoxic pulmonary vasoconstriction (HPV) under generalized hypoxia. Increased proliferation and migration of PASMCs are often associated with high intracellular Ca2+ concentration. Recent publications suggest that Ca2+-permeable nonselective classical transient receptor potential (TRPC) proteins-especially TRPC1 and 6-are crucially involved in acute and sustained hypoxic responses and the pathogenesis of CHPH. The aim of our study was to investigate whether the simultaneous deletion of TRPC proteins 1, 3 and 6 protects against CHPH-development and affects HPV in mice. We used a mouse model of chronic hypoxia as well as isolated, ventilated and perfused mouse lungs and PASMC cell cultures. Although right ventricular systolic pressure as well as echocardiographically assessed PVR and right ventricular wall thickness (RVWT) were lower in TRPC1, 3, 6-deficient mice, these changes were not related to a decreased degree of pulmonary vascular muscularization and a reduced proliferation of PASMCs. However, both acute and sustained HPV were almost absent in the TRPC1, 3, 6-deficient mice and their vasoconstrictor response upon KCl application was reduced. This was further validated by myographical experiments. Our data revealed that 1) TRPC1, 3, 6-deficient mice are partially protected against development of CHPH, 2) these changes may be caused by diminished HPV and not an altered pulmonary vascular remodeling.

13.
Cells ; 11(18)2022 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-36139480

RESUMEN

Our respiratory system is exposed to toxicants and pathogens from both sides: the airways and the vasculature. While tracheal, bronchial and alveolar epithelial cells form a natural barrier in the airways, endothelial cells protect the lung from perfused toxic compounds, particulate matter and invading microorganism in the vascular system. Damages induce inflammation by our immune response and wound healing by (myo)fibroblast proliferation. Members of the transient receptor potential (TRP) superfamily of ion channel are expressed in many cells of the respiratory tract and serve multiple functions in physiology and pathophysiology. TRP expression patterns in non-neuronal cells with a focus on TRPA1, TRPC6, TRPM2, TRPM5, TRPM7, TRPV2, TRPV4 and TRPV6 channels are presented, and their roles in barrier function, immune regulation and phagocytosis are summarized. Moreover, TRP channels as future pharmacological targets in chronic obstructive pulmonary disease (COPD), asthma, cystic and pulmonary fibrosis as well as lung edema are discussed.


Asunto(s)
Canales Catiónicos TRPM , Canales de Potencial de Receptor Transitorio , Células Endoteliales/metabolismo , Pulmón/metabolismo , Material Particulado , Canal Catiónico TRPC6/metabolismo , Canales Catiónicos TRPM/metabolismo , Canales Catiónicos TRPV/metabolismo , Canales de Potencial de Receptor Transitorio/metabolismo
14.
Bioinformatics ; 38(Suppl_2): ii141-ii147, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36124800

RESUMEN

MOTIVATION: As complex tissues are typically composed of various cell types, deconvolution tools have been developed to computationally infer their cellular composition from bulk RNA sequencing (RNA-seq) data. To comprehensively assess deconvolution performance, gold-standard datasets are indispensable. Gold-standard, experimental techniques like flow cytometry or immunohistochemistry are resource-intensive and cannot be systematically applied to the numerous cell types and tissues profiled with high-throughput transcriptomics. The simulation of 'pseudo-bulk' data, generated by aggregating single-cell RNA-seq expression profiles in pre-defined proportions, offers a scalable and cost-effective alternative. This makes it feasible to create in silico gold standards that allow fine-grained control of cell-type fractions not conceivable in an experimental setup. However, at present, no simulation software for generating pseudo-bulk RNA-seq data exists. RESULTS: We developed SimBu, an R package capable of simulating pseudo-bulk samples based on various simulation scenarios, designed to test specific features of deconvolution methods. A unique feature of SimBu is the modeling of cell-type-specific mRNA bias using experimentally derived or data-driven scaling factors. Here, we show that SimBu can generate realistic pseudo-bulk data, recapitulating the biological and statistical features of real RNA-seq data. Finally, we illustrate the impact of mRNA bias on the evaluation of deconvolution tools and provide recommendations for the selection of suitable methods for estimating mRNA content. SimBu is a user-friendly and flexible tool for simulating realistic pseudo-bulk RNA-seq datasets serving as in silico gold-standard for assessing cell-type deconvolution methods. AVAILABILITY AND IMPLEMENTATION: SimBu is freely available at https://github.com/omnideconv/SimBu as an R package under the GPL-3 license. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Perfilación de la Expresión Génica , ARN , Perfilación de la Expresión Génica/métodos , ARN/genética , ARN Mensajero , RNA-Seq , Análisis de Secuencia de ARN/métodos
15.
Microb Genom ; 8(8)2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35917163

RESUMEN

16S rRNA gene profiling is currently the most widely used technique in microbiome research and allows the study of microbial diversity, taxonomic profiling, phylogenetics, functional and network analysis. While a plethora of tools have been developed for the analysis of 16S rRNA gene data, only a few platforms offer a user-friendly interface and none comprehensively covers the whole analysis pipeline from raw data processing down to complex analysis. We introduce Namco, an R shiny application that offers a streamlined interface and serves as a one-stop solution for microbiome analysis. We demonstrate Namco's capabilities by studying the association between a rich fibre diet and the gut microbiota composition. Namco helped to prove the hypothesis that butyrate-producing bacteria are prompted by fibre-enriched intervention. Namco provides a broad range of features from raw data processing and basic statistics down to machine learning and network analysis, thus covering complex data analysis tasks that are not comprehensively covered elsewhere. Namco is freely available at https://exbio.wzw.tum.de/namco/.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Bacterias/genética , Microbioma Gastrointestinal/genética , Microbiota/genética , Filogenia , ARN Ribosómico 16S/genética
16.
Front Oncol ; 12: 931774, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35965494

RESUMEN

Hyperactivation of the RAS-RAF-MEK-ERK cascade - a mitogen-activated protein kinase pathway - has a well-known association with oncogenesis of leading tumor entities, including non-small cell lung cancer, colorectal carcinoma, pancreatic ductal adenocarcinoma, and malignant melanoma. Increasing evidence shows that genetic alterations leading to RAS-RAF-MEK-ERK pathway hyperactivation mediate contact- and soluble-dependent crosstalk between tumor, tumor microenvironment (TME) and the immune system resulting in immune escape mechanisms and establishment of a tumor-sustaining environment. Consequently, pharmacological interruption of this pathway not only leads to tumor-cell intrinsic disruptive effects but also modification of the TME and anti-tumor immunomodulation. At the same time, the importance of ERK signaling in immune cell physiology and potentiation of anti-tumor immune responses through ERK signaling inhibition within immune cell subsets has received growing appreciation. Specifically, a strong case was made for targeted MEK inhibition due to promising associated immune cell intrinsic modulatory effects. However, the successful transition of therapeutic agents interrupting RAS-RAF-MEK-ERK hyperactivation is still being hampered by significant limitations regarding durable efficacy, therapy resistance and toxicity. We here collate and summarize the multifaceted role of RAS-RAF-MEK-ERK signaling in physiology and oncoimmunology and outline the rationale and concepts for exploitation of immunomodulatory properties of RAS-RAF-MEK-ERK inhibition while accentuating the role of MEK inhibition in combinatorial and intermittent anticancer therapy. Furthermore, we point out the extensive scientific efforts dedicated to overcoming the challenges encountered during the clinical transition of various therapeutic agents in the search for the most effective and safe patient- and tumor-tailored treatment approach.

17.
Arch Toxicol ; 96(10): 2767-2783, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35864199

RESUMEN

Sustained exposure of the lung to various environmental or occupational toxins may eventually lead to pulmonary fibrosis, a devastating disease with no cure. Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix (ECM) proteins such as fibronectin and collagens. The peptidase plasmin degrades the ECM, but protein levels of the plasmin activator inhibitor-1 (PAI-1) are increased in fibrotic lung tissue, thereby dampening plasmin activity. Transforming growth factor-ß1 (TGF-ß1)-induced activation of SMAD transcription factors promotes ECM deposition by enhancing collagen, fibronectin and PAI-1 levels in pulmonary fibroblasts. Hence, counteracting TGF-ß1-induced signaling is a promising approach for the therapy of pulmonary fibrosis. Transient receptor potential cation channel subfamily M Member 7 (TRPM7) supports TGF-ß1-promoted SMAD signaling in T-lymphocytes and the progression of fibrosis in kidney and heart. Thus, we investigated possible effects of TRPM7 on plasmin activity, ECM levels and TGF-ß1 signaling in primary human pulmonary fibroblasts (pHPF). We found that two structurally unrelated TRPM7 blockers enhanced plasmin activity and reduced fibronectin or PAI-1 protein levels in pHPF under basal conditions. Further, TRPM7 blockade strongly inhibited fibronectin and collagen deposition induced by sustained TGF-ß1 stimulation. In line with these data, inhibition of TRPM7 activity diminished TGF-ß1-triggered phosphorylation of SMAD-2, SMAD-3/4-dependent reporter activation and PAI-1 mRNA levels. Overall, we uncover TRPM7 as a novel supporter of TGF-ß1 signaling in pHPF and propose TRPM7 blockers as new candidates to control excessive ECM levels under pathophysiological conditions conducive to pulmonary fibrosis.


Asunto(s)
Fibrosis Pulmonar , Canales Catiónicos TRPM , Colágeno/antagonistas & inhibidores , Colágeno/metabolismo , Fibrinolisina/metabolismo , Fibroblastos , Fibronectinas/efectos adversos , Fibronectinas/antagonistas & inhibidores , Fibronectinas/metabolismo , Fibrosis , Humanos , Pulmón/metabolismo , Inhibidor 1 de Activador Plasminogénico/genética , Inhibidor 1 de Activador Plasminogénico/metabolismo , Proteínas Serina-Treonina Quinasas , Fibrosis Pulmonar/inducido químicamente , Canales Catiónicos TRPM/metabolismo , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Factor de Crecimiento Transformador beta1/metabolismo
18.
Eur Respir J ; 60(4)2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35450969

RESUMEN

BACKGROUND: Prostaglandin E2 (PGE2) increases pulmonary vascular permeability by activation of the PGE2 receptor 3 (EP3), which may explain adverse pulmonary effects of the EP1/EP3 receptor agonist sulprostone in patients. In addition, PGE2 contributes to pulmonary oedema in response to platelet-activating factor (PAF). PAF increases endothelial permeability by recruiting the cation channel transient receptor potential canonical 6 (TRPC6) to endothelial caveolae via acid sphingomyelinase (ASMase). Yet, the roles of PGE2 and EP3 in this pathway are unknown. We hypothesised that EP3 receptor activation may increase pulmonary vascular permeability by activation of TRPC6, and thus, synergise with ASMase-mediated TRPC6 recruitment in PAF-induced lung oedema. METHODS: In isolated lungs, we measured increases in endothelial calcium (ΔCa2+) or lung weight (Δweight), and endothelial caveolar TRPC6 abundance as well as phosphorylation. RESULTS: PAF-induced ΔCa2+ and Δweight were attenuated in EP3-deficient mice. Sulprostone replicated PAF-induced ΔCa2+ and Δweight which were blocked by pharmacological/genetic inhibition of TRPC6, ASMase or Src-family kinases (SrcFK). PAF, but not sulprostone, increased TRPC6 abundance in endothelial caveolae. Immunoprecipitation revealed PAF- and sulprostone-induced tyrosine-phosphorylation of TRPC6 that was prevented by inhibition of phospholipase C (PLC) or SrcFK. PLC inhibition also blocked sulprostone-induced ΔCa2+ and Δweight, as did inhibition of SrcFK or inhibitory G-protein (Gi) signalling. CONCLUSIONS: EP3 activation triggers pulmonary oedema via Gi-dependent activation of PLC and subsequent SrcFK-dependent tyrosine phosphorylation of TRPC6. In PAF-induced lung oedema, this TRPC6 activation coincides with ASMase-dependent caveolar recruitment of TRPC6, resulting in rapid endothelial Ca2+ influx and barrier failure.


Asunto(s)
Edema Pulmonar , Animales , Calcio/metabolismo , Edema , Células Endoteliales/metabolismo , Proteínas de Unión al GTP/metabolismo , Pulmón/metabolismo , Ratones , Factor de Activación Plaquetaria , Esfingomielina Fosfodiesterasa , Canal Catiónico TRPC6 , Fosfolipasas de Tipo C/metabolismo , Tirosina , Familia-src Quinasas
19.
Pharmacol Ther ; 237: 108164, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35247518

RESUMEN

Transient receptor potential (TRP) proteins form a superfamily of cation channels that are expressed in a wide range of tissues and cell types. During the last years, great progress has been made in understanding the molecular complexity and the functions of TRP channels in diverse cellular processes, including cell proliferation, migration, adhesion and activation. The diversity of functions depends on multiple regulatory mechanisms by which TRP channels regulate Ca2+ entry mechanisms and intracellular Ca2+ dynamics, either through membrane depolarization involving cation influx or store- and receptor-operated mechanisms. Abnormal function or expression of TRP channels results in vascular pathologies, including hypertension, ischemic stroke and inflammatory disorders through effects on vascular cells, including the components of blood vessels and platelets. Moreover, some TRP family members also regulate megakaryopoiesis and platelet production, indicating a complex role of TRP channels in pathophysiological conditions. In this review, we describe potential roles of TRP channels in megakaryocytes and platelets, as well as their contribution to diseases such as thrombocytopenia, thrombosis and stroke. We also critically discuss the potential of TRP channels as possible targets for disease prevention and treatment.


Asunto(s)
Canales de Potencial de Receptor Transitorio , Plaquetas/metabolismo , Calcio/metabolismo , Señalización del Calcio/fisiología , Cationes/metabolismo , Humanos , Megacariocitos/metabolismo , Canales de Potencial de Receptor Transitorio/metabolismo
20.
J Monet Econ ; 129: S35-S51, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35165494

RESUMEN

A tailor-made survey documents consumers' perceptions of the US economy's response to a large shock: the advent of the COVID-19 pandemic. The survey ran at a daily frequency between March 2020 and July 2021. Consumer's perceptions regarding output and inflation react rapidly. Uncertainty is pervasive. A business-cycle model calibrated to the consumers' views provides an interpretation. The rise in household uncertainty accounts for two-thirds of the fall in output. Different perceptions about monetary policy can explain why consumers and professional forecasters agree on the recessionary impact, but have sharply divergent views about inflation.

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