Molecular underpinnings of cytoskeletal cross-talk

Cross-talk between the microtubule and actin networks has come under intense scrutiny following the realization that it is crucial for numerous essential processes, ranging from cytokinesis to cell migration. It is becoming increasingly clear that proteins long-considered highly specific for one or the other cytoskeletal system do, in fact, make use of both filament types. How this functional duality of “shared proteins” has evolved and how their coadaptation enables cross-talk at the molecular level remain largely unknown. We previously discovered that the mammalian adaptor protein melanophilin of the actin-associated myosin motor is one such “shared protein,” which also interacts with microtubules in vitro. In a hypothesis-driven in vitro and in silico approach, we turn to early and lower vertebrates and ask two fundamental questions. First, is the capability of interacting with microtubules and actin filaments unique to mammalian melanophilin or did it evolve over time? Second, what is the functional consequence of being able to interact with both filament types at the cellular level? We describe the emergence of a protein domain that confers the capability of interacting with both filament types onto melanophilin. Strikingly, our computational modeling demonstrates that the regulatory power of this domain on the microscopic scale alone is sufficient to recapitulate previously observed behavior of pigment organelles in amphibian melanophores. Collectively, our dissection provides a molecular framework for explaining the underpinnings of functional cross-talk and its potential to orchestrate the cell-wide redistribution of organelles on the cytoskeleton.

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Supplementation of a propionate-producing consortium improves markers of insulin resistance in an in vitro model of gut-liver axis

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00523.2019 ◽

2020 ◽

Vol 318 (5) ◽

pp. E742-E749 ◽

Cited By ~ 2

Author(s):

Racha El Hage ◽

Emma Hernandez-Sanabria ◽

Marta Calatayud Arroyo ◽

Tom Van de Wiele

Keyword(s):

Insulin Resistance ◽

Cross Talk ◽

Energy Homeostasis ◽

Metabolic Diseases ◽

Glycogen Synthesis ◽

Short Chain Fatty Acids ◽

Glycogen Storage ◽

Cellular Level ◽

Low Grade

Gut-liver cross talk is an important determinant of human health with profound effects on energy homeostasis. While gut microbes produce a huge range of metabolites, specific compounds such as short-chain fatty acids (SCFAs) can enter the portal circulation and reach the liver (Brandl K, Schnabl B. Curr Opin Gastroenterol 33: 128–133, 2017), a central organ involved in glucose homeostasis and diabetes control. Propionate is a major SCFA involved in activation of intestinal gluconeogenesis (IGN), thereby regulating food intake, enhancing insulin sensitivity, and leading to metabolic homeostasis. Although microbiome-modulating strategies may target the increased microbial production of propionate, it is not clear whether such an effect spreads through to the hepatic cellular level. Here, we designed a propionate-producing consortium using a selection of commensal gut bacteria, and we investigated how their delivered metabolites impact an in vitro enterohepatic model of insulin resistance. Glycogen storage on hepatocyte-like cells and inflammatory markers associated with insulin resistance were evaluated to understand the role of gut metabolites on gut-liver cross talk in a simulated scenario of insulin resistance. The metabolites produced by our consortium increased glycogen synthesis by ~57% and decreased proinflammatory markers such as IL-8 by 12%, thus elucidating the positive effect of our consortium on metabolic function and low-grade inflammation. Our results suggest that microbiota-derived products can be a promising multipurpose strategy to modulate energy homeostasis, with the potential ability to assist in managing metabolic diseases due to their adaptability.

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AP-4 mediated ATG9A sorting underlies axonal and autophagosome biogenesis defects in a mouse model of AP-4 deficiency syndrome

10.1101/235101 ◽

2017 ◽

Cited By ~ 3

Author(s):

Davor Ivankovic ◽

Guillermo López-Doménech ◽

James Drew ◽

Sharon A. Tooze ◽

Josef T. Kittler

Keyword(s):

Mouse Model ◽

Transmembrane Protein ◽

Adaptor Protein ◽

Deficiency Syndrome ◽

Cellular Level ◽

Loss Of Function ◽

Golgi Network ◽

Autophagosome Maturation

AbstractAdaptor protein (AP) complexes have critical roles in transmembrane protein sorting. AP-4 remains poorly understood in the brain despite its loss of function leading to a hereditary spastic paraplegia termed AP-4 deficiency syndrome. Here we demonstrate that knockout (KO) of AP-4 in a mouse model leads to thinning of the corpus callosum and ventricular enlargement, anatomical defects previously described in patients. At the cellular level, we find that AP-4 KO leads to defects in axonal extension and branching, in addition to aberrant distal swellings. Interestingly, we show that ATG9A, a key protein in autophagosome maturation, is critically dependent on AP-4 for its sorting from the trans-golgi network. Failure of AP-4 mediated ATG9A sorting results in its dramatic retention in the trans-golgi network in vitro and in vivo leading to a specific reduction of the axonal pool of ATG9A. As a result, autophagosome biogenesis is aberrant in the axon of AP-4 deficient neurons. The specific alteration to axonal integrity and axonal autophagosome maturation in AP-4 knockout neurons may underpin the pathology of AP-4 deficiency.

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Exploiting Anti-Inflammation Effects of Flavonoids in Chronic Inflammatory Diseases

Current Pharmaceutical Design ◽

10.2174/1381612826666200408101550 ◽

2020 ◽

Vol 26 (22) ◽

pp. 2610-2619 ◽

Cited By ~ 2

Author(s):

Tarique Hussain ◽

Ghulam Murtaza ◽

Huansheng Yang ◽

Muhammad S. Kalhoro ◽

Dildar H. Kalhoro

Keyword(s):

Oxidative Stress ◽

Chronic Diseases ◽

Inflammatory Diseases ◽

Therapeutic Option ◽

Cellular Level ◽

Antiinflammatory Drugs ◽

Suitable Alternative ◽

Chronic Inflammatory Diseases

Background: Inflammation is a complex response of the host defense system to different internal and external stimuli. It is believed that persistent inflammation may lead to chronic inflammatory diseases such as, inflammatory bowel disease, neurological and cardiovascular diseases. Oxidative stress is the main factor responsible for the augmentation of inflammation via various molecular pathways. Therefore, alleviating oxidative stress is effective a therapeutic option against chronic inflammatory diseases. Methods: This review article extends the knowledge of the regulatory mechanisms of flavonoids targeting inflammatory pathways in chronic diseases, which would be the best approach for the development of suitable therapeutic agents against chronic diseases. Results: Since the inflammatory response is initiated by numerous signaling molecules like NF-κB, MAPK, and Arachidonic acid pathways, their encountering function can be evaluated with the activation of Nrf2 pathway, a promising approach to inhibit/prevent chronic inflammatory diseases by flavonoids. Over the last few decades, flavonoids drew much attention as a potent alternative therapeutic agent. Recent clinical evidence has shown significant impacts of flavonoids on chronic diseases in different in-vivo and in-vitro models. Conclusion: Flavonoid compounds can interact with chronic inflammatory diseases at the cellular level and modulate the response of protein pathways. A promising approach is needed to overlook suitable alternative compounds providing more therapeutic efficacy and exerting fewer side effects than commercially available antiinflammatory drugs.

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Adipo-Derived Stem Cell Features and MCF-7

Cells ◽

10.3390/cells10071754 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1754

Author(s):

Giuseppe Garroni ◽

Francesca Balzano ◽

Sara Cruciani ◽

Renzo Pala ◽

Donatella Coradduzza ◽

...

Keyword(s):

Stem Cell ◽

Molecular Level ◽

Cancer Cell Line ◽

Human Adipose Tissue ◽

Cell Cycle Regulators ◽

Culturing Conditions ◽

And Migration ◽

Related Proteins ◽

Mcf 7

Human adipose tissue-derived stem cells (hADSCs) are highly suitable for regeneration therapies being easily collected and propagated in vitro. The effects of different external factors and culturing conditions are able to affect hADSC proliferation, senescence, differentiation, and migration, even at the molecular level. In the present paper, we exposed hADSCs to an exhausted medium from the breast cancer cell line (MCF-7) to evaluate whether the soluble factors released by these cells may be able to induce changes in stem cell behavior. In particular, we investigated the expression of stemness-related genes (OCT4; Sox 2; Nanog), the cell-cycle regulators p21 (WAF1/CIP1) p53, epigenetic markers (DNMT1 and Sirt1), and autophagy-related proteins. From our results, we can infer that the exhausted medium from MCF-7 is able to influence the hADSCs behavior increasing the expression of stemness-related genes, cell proliferation, and autophagy. Polyamines detectable in MCF-7 exhausted medium could be related to the higher proliferation capability observed in hADSCs, suggesting direct crosstalk between these molecules and the observed changes in stem cell potency.

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Co-culture of monocytes and zona fasciculata adrenal cells: An in vitro model to study the immune-adrenal cross-talk

Molecular and Cellular Endocrinology ◽

10.1016/j.mce.2021.111195 ◽

2021 ◽

Vol 526 ◽

pp. 111195

Author(s):

Daniel P. Fudulu ◽

George Horn ◽

Georgina Hazell ◽

Anne-Marie Lefrançois-Martinez ◽

Antoine Martinez ◽

...

Keyword(s):

Cross Talk ◽

In Vitro Model ◽

Zona Fasciculata ◽

Adrenal Cells ◽

Vitro Model

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Investigation of Chlorella pyrenoidosa Protein as a Source of Novel Angiotensin I-Converting Enzyme (ACE) and Dipeptidyl Peptidase-IV (DPP-IV) Inhibitory Peptides

Nutrients ◽

10.3390/nu13051624 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1624

Author(s):

Yuchen Li ◽

Gilda Aiello ◽

Enrico Mario Alessandro Fassi ◽

Giovanna Boschin ◽

Martina Bartolomei ◽

...

Keyword(s):

Chlorella Pyrenoidosa ◽

Cellular Level ◽

Potential Interaction ◽

Converting Enzyme ◽

Inhibitory Peptides ◽

Angiotensin I Converting Enzyme ◽

Dpp Iv ◽

Ace Activity ◽

The Stability

Chlorella pyrenoidosa (C. pyrenoidosa) is a microalgae species with a remarkably high protein content that may potentially become a source of hypotensive and hypoglycemic peptides. In this study, C. pyrenoidosa proteins were extracted and hydrolyzed overnight with pepsin and trypsin with final degrees of hydrolysis of 18.7% and 35.5%, respectively. By LC-MS/MS, 47 valid peptides were identified in the peptic hydrolysate (CP) and 66 in the tryptic one (CT). At the concentration of 1.0 mg/mL, CP and CT hydrolysates inhibit in vitro the angiotensin-converting enzyme (ACE) activity by 84.2 ± 0.37% and 78.6 ± 1.7%, respectively, whereas, tested at cellular level at the concentration of 5.0 mg/mL, they reduce the ACE activity by 61.5 ± 7.7% and 69.9 ± 0.8%, respectively. At the concentration of 5.0 mg/mL, they decrease in vitro the DPP-IV activity by 63.7% and 69.6% and in Caco-2 cells by 38.4% and 42.5%, respectively. Short peptides (≤10 amino acids) were selected for investigating the potential interaction with ACE and DPP-IV by using molecular modeling approaches and four peptides were predicted to block both enzymes. Finally, the stability of these peptides was investigated against gastrointestinal digestion.

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Lipopolysaccharide induces neuroinflammation in microglia by activating the MTOR pathway and downregulating Vps34 to inhibit autophagosome formation

Journal of Neuroinflammation ◽

10.1186/s12974-019-1644-8 ◽

2020 ◽

Vol 17 (1) ◽

Cited By ~ 8

Author(s):

Xiaoxia Ye ◽

Mingming Zhu ◽

Xiaohang Che ◽

Huiyang Wang ◽

Xing-Jie Liang ◽

...

Keyword(s):

Inflammatory Response ◽

Microglial Activation ◽

Adaptor Protein ◽

Mtor Pathway ◽

Microglial Cells ◽

Inflammatory Factors ◽

Intraventricular Injection ◽

Enzyme Linked Immunosorbent Assay ◽

Autophagic Flux

Abstract Background Microglial activation is a prominent feature of neuroinflammation, which is present in almost all neurodegenerative diseases. While an initial inflammatory response mediated by microglia is considered to be protective, excessive pro-inflammatory response of microglia contributes to the pathogenesis of neurodegeneration. Although autophagy is involved in the suppression of inflammation, its role and mechanism in microglia are unclear. Methods In the present study, we studied the mechanism by which lipopolysaccharide (LPS) affects microglial autophagy and the effects of autophagy on the production of pro-inflammatory factors in microglial cells by western blotting, immunocytochemistry, transfection, transmission electron microscopy (TEM), and real-time PCR. In a mouse model of neuroinflammation, generated by intraventricular injection of LPS (5 μg/animal), we induced autophagy by rapamycin injection and investigated the effects of enhanced autophagy on microglial activation by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. Results We found that autophagic flux was suppressed in LPS-stimulated N9 microglial cells, as evidenced by decreased expression of the autophagy marker LC3-II (lipidated form of MAP1LC3), as well as increased levels of the autophagy adaptor protein SQSTM1. LPS significantly decreased Vps34 expression in N9 microglial cells by activating the PI3KI/AKT/MTOR pathway without affecting the levels of lysosome-associated proteins and enzymes. More importantly, overexpression of Vps34 significantly enhanced the autophagic flux and decreased the accumulation of SQSTM1 in LPS-stimulated N9 microglial cells. Moreover, our results revealed that an LPS-induced reduction in the level of Vps34 prevented the maturation of omegasomes to phagophores. Furthermore, LPS-induced neuroinflammation was significantly ameliorated by treatment with the autophagy inducer rapamycin both in vitro and in vivo. Conclusions These data reveal that LPS-induced neuroinflammation in N9 microglial cells is associated with the inhibition of autophagic flux through the activation of the PI3KI/AKT/MTOR pathway, while enhanced microglial autophagy downregulates LPS-induced neuroinflammation. Thus, this study suggests that promoting the early stages of autophagy might be a potential therapeutic approach for neuroinflammation-associated diseases.

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Direct Neuronal Reprogramming of Common Marmoset Fibroblasts by ASCL1, microRNA-9/9*, and microRNA-124 Overexpression

Cells ◽

10.3390/cells10010006 ◽

2020 ◽

Vol 10 (1) ◽

pp. 6

Author(s):

Akisa Nemoto ◽

Reona Kobayashi ◽

Sho Yoshimatsu ◽

Yuta Sato ◽

Takahiro Kondo ◽

...

Keyword(s):

Late Onset ◽

Common Marmoset ◽

Cellular Level ◽

Biomedical Science ◽

Disease Models ◽

Specific Gene ◽

Bhlh Transcription Factor ◽

Research Fields ◽

Microrna 124

The common marmoset (Callithrix jacchus) has attracted considerable attention, especially in the biomedical science and neuroscience research fields, because of its potential to recapitulate the complex and multidimensional phenotypes of human diseases, and several neurodegenerative transgenic models have been reported. However, there remain several issues as (i) it takes years to generate late-onset disease models, and (ii) the onset age and severity of phenotypes can vary among individuals due to differences in genetic background. In the present study, we established an efficient and rapid direct neuronal induction method (induced neurons; iNs) from embryonic and adult marmoset fibroblasts to investigate cellular-level phenotypes in the marmoset brain in vitro. We overexpressed reprogramming effectors, i.e., microRNA-9/9*, microRNA-124, and Achaete-Scute family bHLH transcription factor 1, in fibroblasts with a small molecule cocktail that facilitates neuronal induction. The resultant iNs from embryonic and adult marmoset fibroblasts showed neuronal characteristics within two weeks, including neuron-specific gene expression and spontaneous neuronal activity. As directly reprogrammed neurons have been shown to model neurodegenerative disorders, the neuronal reprogramming of marmoset fibroblasts may offer new tools for investigating neurological phenotypes associated with disease progression in non-human primate neurological disease models.

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Natural Variation in Plant Pluripotency and Regeneration

Plants ◽

10.3390/plants9101261 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1261

Author(s):

Robin Lardon ◽

Danny Geelen

Keyword(s):

De Novo ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Relative Role ◽

Root Explants ◽

Experimental Systems ◽

Complex Process ◽

Insight Into ◽

Molecular Framework

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.

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