Biofilm Architectural Breakdown in Response to Antibiotics Facilitates Community Invasion

2020 ◽  
Author(s):  
Francisco Diaz-Pascual ◽  
Knut Drescher
Keyword(s):  
Single Cell ◽  
Cell Volume ◽  
Metabolic Effects ◽  
Matrix Composition ◽  
Bacterial Cells ◽  
Isolated Cells ◽  
Matrix Cell ◽  
Biofilm Architecture ◽  
And Function ◽  
Induced Changes

<p>Bacterial cells are often exposed to stress by changes in their environment. During the last decades the response of isolated cells to stress has been investigated in great detail. By contrast, little is known about the emergent multicellular level responses to stress, such as antibiotic exposure. Studying responses at the community level is key to understand the structure and function of the most common bacterial state: the multicellular communities termed biofilms. Here, by analysing <em>Vibrio cholerae</em> biofilms exposed to all different classes of antibiotics with single-cell resolution, we found that inhibition of protein synthesis cause striking changes in cell volume and biofilm architecture. The observed changes in cell volume are a single-cell level response driven by metabolic effects of the translational inhibition. The multicellular-level responses result from changes in matrix composition, matrix-cell dissociation and mechanical properties of the biofilms. We observed that these antibiotic-induced changes in biofilm architecture have strong consequences on the ecological dynamics of biofilms by making biofilms prone to invasion by bacteriophages and other bacterial cells. These mechanistic and ecological consequences of the emergent group-level architectural response to antibiotics are important to fully understand the ecological succession of biofilms and the implications of antibiotic therapy.</p>

scholarly journals Single cell transcriptomic analysis of murine lung development on hyperoxia-induced damage

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Hurskainen ◽  
Ivana Mižíková ◽  
David P. Cook ◽  
Noora Andersson ◽  
Chanèle Cyr-Depauw ◽  
...  
Keyword(s):  
Single Cell ◽  
Lung Development ◽  
Alveolar Epithelium ◽  
Cell Types ◽  
Capillary Endothelium ◽  
Stromal Fibroblasts ◽  
Main Driver ◽  
Macrophage Populations ◽  
Induced Changes ◽  
Cellular Compartments

AbstractDuring late lung development, alveolar and microvascular development is finalized to enable sufficient gas exchange. Impaired late lung development manifests as bronchopulmonary dysplasia (BPD) in preterm infants. Single-cell RNA sequencing (scRNA-seq) allows for assessment of complex cellular dynamics during biological processes, such as development. Here, we use MULTI-seq to generate scRNA-seq profiles of over 66,000 cells from 36 mice during normal or impaired lung development secondary to hyperoxia with validation of some of the findings in lungs from BPD patients. We observe dynamic populations of cells, including several rare cell types and putative progenitors. Hyperoxia exposure, which mimics the BPD phenotype, alters the composition of all cellular compartments, particularly alveolar epithelium, stromal fibroblasts, capillary endothelium and macrophage populations. Pathway analysis and predicted dynamic cellular crosstalk suggest inflammatory signaling as the main driver of hyperoxia-induced changes. Our data provides a single-cell view of cellular changes associated with late lung development in health and disease.

Changes in Astroglial Cell Volume after Exposure to HgCl2 or CH3HgCl

1992 ◽  
Vol 20 (2) ◽  
pp. 246-250
Author(s):  
Lars Rönnbäck ◽  
Elisabeth Hansson
Keyword(s):  
Glucose Uptake ◽  
Cell Volume ◽  
Receptor Agonist ◽  
Primary Cultures ◽  
Control Cell ◽  
Astroglial Cell ◽  
Receptor Stimulation ◽  
Adrenoceptor Agonists ◽  
Β Receptor ◽  
Induced Changes

Cell volume was determined by measuring [14C]-3- O-methyl glucose uptake in astroglial-enriched primary cultures. Control cell volume was 3.20μl/mg protein. After incubation in 10 5M HgCl2 for 60 minutes, there was a 71% increase in cell volume. This increase was partially inhibited in the presence of the α1 receptor agonist, phenylephrine, or by the α2 receptor agonist clonidine, and was completely reversible by their respective antagonists, prazosine and yohimbine. The β receptor agonist, isoproterenol, which in itself increased cell volume, and 5-hydroxytryptamine (5HT) did not affect the HgCl2-induced changes in cell volume. 10 5M CH3HgCl increased cell volume by 26% after 30 minutes of incubation. This increase was not significantly influenced by adrenoceptor agonists or 5HT. It therefore seems that mercurial-induced changes in cell volume can be regulated by astroglial receptor stimulation.

scholarly journals Complementary vasoactivity and matrix remodelling in arterial adaptations to altered flow and pressure

2008 ◽  
Vol 6 (32) ◽  
pp. 293-306 ◽  
Author(s):  
A Valentín ◽  
L Cardamone ◽  
S Baek ◽  
J.D Humphrey
Keyword(s):  
Smooth Muscle ◽  
Continuum Theory ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Rates Of Change ◽  
Biomechanical Loading ◽  
Smooth Muscle Proliferation ◽  
And Function ◽  
Diverse Data ◽  
Induced Changes

Arteries exhibit a remarkable ability to adapt to sustained alterations in biomechanical loading, probably via mechanisms that are similarly involved in many arterial pathologies and responses to treatment. Of particular note, diverse data suggest that cell and matrix turnover within vasoaltered states enables arteries to adapt to sustained changes in blood flow and pressure. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodelling work together to adapt the geometry, structure, stiffness and function of a representative basilar artery. Towards this end, we employ a continuum theory of constrained mixtures to model evolving changes in the wall, which depend on both wall shear stress-induced changes in vasoactive molecules (which alter smooth muscle proliferation and synthesis of matrix) and intramural stress-induced changes in growth factors (which alter cell and matrix turnover). Simulations show, for example, that such considerations help explain the different rates of experimentally observed adaptations to increased versus decreased flows as well as differences in rates of change in response to increased flows or pressures.

scholarly journals Oestrogen replacement fails to fully revert ovariectomy-induced changes in adipose tissue monoglycerides, diglycerides and cholesteryl esters of rats fed a lard-enriched diet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Valter Tadeu Boldarine ◽  
Ellen Joyce ◽  
Amanda Paula Pedroso ◽  
Mônica Marques Telles ◽  
Lila Missae Oyama ◽  
...  
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Neutral Lipids ◽  
Saturated Fat ◽  
Metabolic Effects ◽  
Cholesteryl Esters ◽  
Ovx Rats ◽  
Lipid Species ◽  
Retroperitoneal White Adipose Tissue ◽  
Induced Changes

AbstractMenopause may be accompanied by abdominal obesity and inflammation, conditions accentuated by high-fat intake, especially of saturated fat (SFA)-rich diets. We investigated the consequences of high-SFA intake on the fatty acid (FA) profile of monoglycerides, diglycerides and cholesteryl esters from retroperitoneal white adipose tissue (RET) of rats with ovariectomy-induced menopause, and the effect of oestradiol replacement. Wistar rats were either ovariectomized (Ovx) or sham operated (Sham) and fed either standard chow (C) or lard-enriched diet (L) for 12 weeks. Half of the Ovx rats received 17β-oestradiol replacement (Ovx + E2). Body weight and food intake were measured weekly. RET neutral lipids were chromatographically separated and FAs analysed by gas chromatography. Ovariectomy alone increased body weight, feed efficiency, RET mass, leptin and insulin levels, leptin/adiponectin ratio, HOMA-IR and HOMA-β indexes. OvxC + E2 showed attenuation in nearly all blood markers. HOMA-β index was restored in OvxL + E2. OvxC showed significantly disturbed SFA and polyunsaturated FA (PUFA) profile in RET cholesteryl esters (CE). OvxC also showed increased monounsaturated FA (MUFA) in the monoglyceride diglyceride (Mono–Di) fraction. Similar changes were not observed in OvxL, although increased SFA and decreased PUFA was observed in Mono–Di. Overall, HRT was only partially able to revert changes induced by ovariectomy. There appears to be increased mobilization of essential FA in Ovx via CE, which is a dynamic lipid species. The same results were not found in Mono–Di, which are more inert. HRT may be helpful to preserve FA profile in visceral fat, but possibly not wholly sufficient in reverting the metabolic effects induced by menopause.

scholarly journals Prokaryotic Single-Cell RNA Sequencing by In Situ Combinatorial Indexing

2019 ◽  
Author(s):  
Sydney B. Blattman ◽  
Wenyan Jiang ◽  
Panos Oikonomou ◽  
Saeed Tavazoie
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Low Cost ◽  
Bacterial Cells ◽  
Single Experiment ◽  
Bacterial Populations ◽  
Single Cell Rna Sequencing ◽  
Gene Expression Heterogeneity ◽  
Mrna Polyadenylation

AbstractDespite longstanding appreciation of gene expression heterogeneity in isogenic bacterial populations, affordable and scalable technologies for studying single bacterial cells have been limited. While single-cell RNA sequencing (scRNA-seq) has revolutionized studies of transcriptional heterogeneity in diverse eukaryotic systems, application of scRNA-seq to prokaryotes has been hindered by their extremely low mRNA abundance, lack of mRNA polyadenylation, and thick cell walls. Here, we present Prokaryotic Expression-profiling by Tagging RNA In Situ and sequencing (PETRI-seq), a low-cost, high-throughput, prokaryotic scRNA-seq pipeline that overcomes these technical obstacles. PETRI-seq uses in situ combinatorial indexing to barcode transcripts from tens of thousands of cells in a single experiment. PETRI-seq captures single cell transcriptomes of Gram-negative and Gram-positive bacteria with high purity and low bias, with median capture rates >200 mRNAs/cell for exponentially growing E. coli. These characteristics enable robust discrimination of cell-states corresponding to different phases of growth. When applied to wild-type S. aureus, PETRI-seq revealed a rare sub-population of cells undergoing prophage induction. We anticipate broad utility of PETRI-seq in defining single-cell states and their dynamics in complex microbial communities.

scholarly journals Single cell RNA sequencing of calvarial and long bone endocortical cells

2019 ◽  
Author(s):  
Ugur M. Ayturk ◽  
Joseph P. Scollan ◽  
Alexander Vesprey ◽  
Christina M. Jacobsen ◽  
Paola Divieti Pajevic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Cultured Cells ◽  
Neutralizing Antibody ◽  
Long Bone ◽  
Appendicular Skeleton ◽  
Rna Seq ◽  
Isolated Cells

ABSTRACTSingle cell RNA-seq (scRNA-seq) is emerging as a powerful technology to examine transcriptomes of individual cells. We determined whether scRNA-seq could be used to detect the effect of environmental and pharmacologic perturbations on osteoblasts. We began with a commonly used in vitro system in which freshly isolated neonatal mouse calvarial cells are expanded and induced to produce a mineralized matrix. We used scRNA-seq to compare the relative cell type abundances and the transcriptomes of freshly isolated cells to those that had been cultured for 12 days in vitro. We observed that the percentage of macrophage-like cells increased from 6% in freshly isolated calvarial cells to 34% in cultured cells. We also found that Bglap transcripts were abundant in freshly isolated osteoblasts but nearly undetectable in the cultured calvarial cells. Thus, scRNA-seq revealed significant differences between heterogeneity of cells in vivo and in vitro. We next performed scRNA-seq on freshly recovered long bone endocortical cells from mice that received either vehicle or Sclerostin-neutralizing antibody for 1 week. Bone anabolism-associated transcripts were also not significantly increased in immature and mature osteoblasts recovered from Sclerostin-neutralizing antibody treated mice; this is likely a consequence of being underpowered to detect modest changes in gene expression, since only 7% of the sequenced endocortical cells were osteoblasts, and a limited portion of their transcriptomes were sampled. We conclude that scRNA-seq can detect changes in cell abundance, identity, and gene expression in skeletally derived cells. In order to detect modest changes in osteoblast gene expression at the single cell level in the appendicular skeleton, larger numbers of osteoblasts from endocortical bone are required.

scholarly journals Non-invasive stimulation of vagal afferents reduces gastric frequency

2019 ◽  
Author(s):  
Vanessa Teckentrup ◽  
Sandra Neubert ◽  
João C. P. Santiago ◽  
Manfred Hallschmid ◽  
Martin Walter ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Vagus Nerve ◽  
Energy Homeostasis ◽  
Resting Energy Expenditure ◽  
Vagal Afferents ◽  
Metabolic Effects ◽  
Net Energy ◽  
Non Invasive ◽  
Induced Changes ◽  
Stimulation Of

AbstractMetabolic feedback between the gut and the brain relayed via the vagus nerve contributes to energy homeostasis. We investigated in healthy adults whether non-invasive stimulation of vagal afferents impacts energy homeostasis via efferent effects on metabolism or digestion. In a randomized crossover design, we applied transcutaneous auricular vagus nerve stimulation (taVNS) while recording efferent metabolic effects using simultaneous electrogastrography (EGG) and indirect calorimetry. We found that taVNS reduced gastric myoelectric frequency (p =.008), but did not alter resting energy expenditure. We conclude that stimulating vagal afferents induces gastric slowing via vagal efferents without acutely affecting net energy expenditure at rest. Collectively, this highlights the potential of taVNS to modulate digestion by activating the dorsal vagal complex. Thus, taVNS-induced changes in gastric frequency are an important peripheral marker of brain stimulation effects.

scholarly journals New gene discoveries in skeletal diseases with short stature

2021 ◽  
Author(s):  
Alice Costantini ◽  
Mari H Muurinen ◽  
Outi Mäkitie
Keyword(s):  
Short Stature ◽  
Molecular Mechanisms ◽  
Bone Growth ◽  
Massively Parallel Sequencing ◽  
Matrix Composition ◽  
Biological Processes ◽  
Novel Gene ◽  
Genetic Mechanisms ◽  
New Gene ◽  
And Function

In the last decade, the widespread use of massively-parallel sequencing has considerably boosted the number of novel gene discoveries in monogenic skeletal diseases with short stature. Defects in genes playing a role in the maintenance and function of the growth plate, the site of longitudinal bone growth, are a well-known cause of skeletal diseases with short stature. However, several genes involved in extracellular matrix composition or maintenance as well as genes partaking in various biological processes have also been characterized. This review aims to describe the latest genetic findings in spondyloepiphyseal and spondyloepimetaphyseal dysplasias and in some monogenic forms of isolated short stature. Strategies on how to successfully characterize novel skeletal phenotypes with short stature and genetic approaches to detect and validate novel gene-disease correlations will be discussed in detail. Finally, novel genetic mechanisms in the field of skeletal diseases, including variants affecting miRNAs and disrupting the chromatin structure, will be described. In summary, we discuss the latest gene discoveries underlying skeletal diseases with short stature and emphasize the importance of characterizing novel molecular mechanisms for genetic counseling, optimal management of the disease and for therapeutic innovations.

scholarly journals Spatial and single-cell transcriptional landscape of human cerebellar development

2020 ◽  
Author(s):  
Kimberly A. Aldinger ◽  
Zach Thomson ◽  
Parthiv Haldipur ◽  
Mei Deng ◽  
Andrew E. Timms ◽  
...  
Keyword(s):  
Single Cell ◽  
Emotional Regulation ◽  
Cell Types ◽  
Molecular Organization ◽  
Cerebellar Development ◽  
Disease Genes ◽  
Spatially Resolved ◽  
Human Cerebellum ◽  
Spatial Composition ◽  
And Function

ABSTRACTCerebellar development and function require precise regulation of molecular and cellular programs to coordinate motor functions and integrate network signals required for cognition and emotional regulation. However, molecular understanding of human cerebellar development is limited. Here, we combined spatially resolved and single-cell transcriptomics to systematically map the molecular, cellular, and spatial composition of early and mid-gestational human cerebellum. This enabled us to transcriptionally profile major cell types and examine the dynamics of gene expression within cell types and lineages across development. The resulting ‘Developmental Cell Atlas of the Human Cerebellum’ demonstrates that the molecular organization of the cerebellar anlage reflects cytoarchitecturally distinct regions and developmentally transient cell types that are insufficiently captured in bulk transcriptional profiles. By mapping disease genes onto cell types, we implicate the dysregulation of specific cerebellar cell types, especially Purkinje cells, in pediatric and adult neurological disorders. These data provide a critical resource for understanding human cerebellar development with implications for the cellular basis of cerebellar diseases.

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