scholarly journals ACTH Induces ERK 1/2 Activation in Rat Adrenal Primary Cultures

2008 ◽  
Vol 14 (S3) ◽  
pp. 101-102
Author(s):  
A.R. Rodrigues ◽  
A.M. Gouveia ◽  
J.G. Ferreira ◽  
H. Almeida
Keyword(s):  
Adrenocorticotropic Hormone ◽  
Primary Cultures ◽  
Signalling Pathways ◽  
Tumour Cell Line ◽  
Adrenal Cells ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Mitogen Activated Protein ◽  
G Protein Coupled

Adrenocorticotropic hormone (ACTH) is the most potent stimulator of adrenal cortex, acting through the Melanocortin-2 receptor (MC2R). ACTH induces secretion of steroid hormones, critical for the normal stress response and plays also an important role on cell proliferation and differentiation. MC2R is a classical G-Protein coupled receptor (GPCR), thus activating Protein Kinase A (PKA). However, many studies suggested a cross-talk between different signalling pathways and a more complex intracellular network. In fact, in adrenocortical Y1 tumour cell line, ACTH may activate Extracellular Regulated Kinases 1/2 (ERK 1/2), which belong to the Mitogen-Activated Protein Kinases (MAPKs) family. In addition, this pathway was implicated in in vivo proliferation and steroidogenesis as shown by our group. In order to further explore and clarify ACTH signalling mechanisms, we made the present work to establish a model of primary cultures of rat adrenal cells.

scholarly journals Mechanics of the cellular microenvironment as perceived by cells in vivo

2021 ◽  
Author(s):  
Alessandro Mongera ◽  
Marie Pochitaloff ◽  
Hannah J. Gustafson ◽  
Georgina A. Stooke-Vaughan ◽  
Payam Rowghanian ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Mechanical Parameters ◽  
Cellular Microenvironment ◽  
Stem Cell Maintenance ◽  
Quantitative Studies ◽  
Cell Proliferation And Differentiation ◽  
3D Microenvironment ◽  
Proliferation And Differentiation

Tissue morphogenesis and repair, as well as organ homeostasis, require cells to constantly monitor their 3D microenvironment and adapt their behaviors in response to local biochemical and mechanical cues1-6. In vitro studies have shown that substrate stiffness and stress relaxation are important mechanical parameters in the control of cell proliferation and differentiation, stem cell maintenance, cell migration 7-11, as well as tumor progression and metastasis12,13. Yet, the mechanical parameters of the microenvironment that cells perceive in vivo, within 3D tissues, remain unknown. In complex materials with strain- and time-dependent material properties, the perceived mechanical parameters depend both on the strain and timescales at which the material is mechanically probed14. Here, we quantify in vivo and in situ the mechanics of the cellular microenvironment that cells probe during vertebrate presomitic mesoderm (PSM) specification. By analyzing the magnitude and dynamics of endogenous, cell-generated strains, we show that individual cells preferentially probe the stiffness associated with deformations of the supracellular, foam-like tissue architecture. We reveal how stress relaxation leads to a perceived microenvironment stiffness that decreases over time, with cells probing the softest regime. While stress relaxation timescales are spatially uniform in the tissue, most mechanical parameters, including those probed by cells, vary along the anteroposterior axis, as mesodermal progenitors commit to different lineages. Understanding the mechanical parameters that cells probe in their native 3D environment is important for quantitative studies of mechanosensation in vivo2-4,6,15 and can help design scaffolds for tissue engineering applications16-18.

scholarly journals Adrenal Cell Aldosterone Production Is Stimulated by Very-Low-Density Lipoprotein (VLDL)

Endocrinology ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 721-731 ◽  
Author(s):  
Yewei Xing ◽  
William E. Rainey ◽  
John W. Apolzan ◽  
Omar L. Francone ◽  
Ruth B. S. Harris ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Primary Cultures ◽  
Signal Transduction Pathway ◽  
Free Calcium ◽  
Low Density ◽  
Dependent Manner ◽  
Very Low Density Lipoproteins ◽  
Concentration Dependent Manner ◽  
Adrenal Cells

Very low-density lipoproteins (VLDL) are a class of large lipoprotein synthesized in the liver. The key function of VLDL, in vivo, is to carry triglyceride from the liver to adipose tissue. As a steroidogenic organ, the adrenal gland mainly uses lipoproteins as sources of cholesterol. Although VLDL receptors have been detected in the human adrenal, the function of VLDL in the adrenal gland remains unknown. Herein, we used primary cultures of human and bovine adrenal cells and the adrenocortical cell line H295R as models to determine the effects of VLDL on adrenal steroidogenesis. Our studies revealed that VLDL significantly increased aldosterone synthesis in all of the models tested. This increase was largely due to VLDL's stimulation of the expression of steroidogenic acute regulatory (StAR) protein and aldosterone synthase (CYP11B2). VLDL increased CYP11B2 mRNA expression in a concentration-dependent manner. Effects of VLDL on CYP11B2 transcript levels were not additive with angiotensin II or potassium but were additive with the cAMP pathway agonists ACTH and forskolin. Nifedipine completely inhibited the effects of VLDL on CYP11B2 mRNA, suggesting that calcium is the main signal transduction pathway used by VLDL in adrenal cells. Indeed, VLDL increased cytosolic free calcium levels. An in vivo study conducted in sucrose-fed rats showed a positive correlation between elevated triglyceride (VLDL) levels in plasma and CYP11B2 expression in the adrenal. In conclusion, we have shown that VLDL can stimulate aldosterone synthesis in adrenocortical cells by increasing StAR and CYP11B2 expression, an event likely mediated by a calcium-initiated signaling cascade.

scholarly journals Critical role of integrin CD11c in splenic dendritic cell capture of missing-self CD47 cells to induce adaptive immunity

2018 ◽  
Vol 115 (26) ◽  
pp. 6786-6791 ◽  
Author(s):  
Jiaxi Wu ◽  
Huaizhu Wu ◽  
Jinping An ◽  
Christie M. Ballantyne ◽  
Jason G. Cyster
Keyword(s):  
Critical Role ◽  
T Cell Proliferation ◽  
Cell Capture ◽  
Antigen Uptake ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Missing Self

CD11c, also known as integrin alpha X, is the most widely used defining marker for dendritic cells (DCs). CD11c can bind complement iC3b and mediate phagocytosis in vitro, for which it is also referred to as complement receptor 4. However, the functions of this prominent marker protein in DCs, especially in vivo, remain poorly defined. Here, in the process of studying DC activation and immune responses induced by cells lacking self-CD47, we found that DC capture of CD47-deficient cells and DC activation was dependent on the integrin-signaling adaptor Talin1. Specifically, CD11c and its partner Itgb2 were required for DC capture of CD47-deficient cells. CD11b was not necessary for this process but could partially compensate in the absence of CD11c. Mice with DCs lacking Talin1, Itgb2, or CD11c were defective in supporting T-cell proliferation and differentiation induced by CD47-deficient cell associated antigen. These findings establish a critical role for CD11c in DC antigen uptake and activation in vivo. They may also contribute to understanding the functional mechanism of CD47-blockade therapies.

scholarly journals Klf5 regulates muscle differentiation by directly targeting muscle-specific genes in cooperation with MyoD in mice

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Shinichiro Hayashi ◽  
Ichiro Manabe ◽  
Yumi Suzuki ◽  
Frédéric Relaix ◽  
Yumiko Oishi
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Myogenic Differentiation ◽  
Muscle Differentiation ◽  
Skeletal Muscle Regeneration ◽  
Biological Processes ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Acting In Concert

Krüppel-like factor 5 (Klf5) is a zinc-finger transcription factor that controls various biological processes, including cell proliferation and differentiation. We show that Klf5 is also an essential mediator of skeletal muscle regeneration and myogenic differentiation. During muscle regeneration after injury (cardiotoxin injection), Klf5 was induced in the nuclei of differentiating myoblasts and newly formed myofibers expressing myogenin in vivo. Satellite cell-specific Klf5 deletion severely impaired muscle regeneration, and myotube formation was suppressed in Klf5-deleted cultured C2C12 myoblasts and satellite cells. Klf5 knockdown suppressed induction of muscle differentiation-related genes, including myogenin. Klf5 ChIP-seq revealed that Klf5 binding overlaps that of MyoD and Mef2, and Klf5 physically associates with both MyoD and Mef2. In addition, MyoD recruitment was greatly reduced in the absence of Klf5. These results indicate that Klf5 is an essential regulator of skeletal muscle differentiation, acting in concert with myogenic transcription factors such as MyoD and Mef2.

scholarly journals A role for GPx3 in activity of normal and leukemia stem cells

2012 ◽  
Vol 209 (5) ◽  
pp. 895-901 ◽  
Author(s):  
Olivier Herault ◽  
Kristin J. Hope ◽  
Eric Deneault ◽  
Nadine Mayotte ◽  
Jalila Chagraoui ◽  
...  
Keyword(s):  
Stem Cells ◽  
Low Frequency ◽  
Leukemia Stem Cells ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Progenitor Cell Proliferation ◽  
Novel Target

The determinants of normal and leukemic stem cell self-renewal remain poorly characterized. We report that expression of the reactive oxygen species (ROS) scavenger glutathione peroxidase 3 (GPx3) positively correlates with the frequency of leukemia stem cells (LSCs) in Hoxa9+Meis1-induced leukemias. Compared with a leukemia with a low frequency of LSCs, a leukemia with a high frequency of LSCs showed hypomethylation of the Gpx3 promoter region, and expressed high levels of Gpx3 and low levels of ROS. LSCs and normal hematopoietic stem cells (HSCs) engineered to express Gpx3 short hairpin RNA (shRNA) were much less competitive in vivo than control cells. However, progenitor cell proliferation and differentiation was not affected by Gpx3 shRNA. Consistent with this, HSCs overexpressing Gpx3 were significantly more competitive than control cells in long-term repopulation experiments, and overexpression of the self-renewal genes Prdm16 or Hoxb4 boosted Gpx3 expression. In human primary acute myeloid leukemia samples, GPX3 expression level directly correlated with adverse prognostic outcome, revealing a potential novel target for the eradication of LSCs.

scholarly journals Maximal Induction of a Subset of Interferon Target Genes Requires the Chromatin-Remodeling Activity of the BAF Complex

2002 ◽  
Vol 22 (18) ◽  
pp. 6471-6479 ◽  
Author(s):  
Hong Liu ◽  
Hyeog Kang ◽  
Rui Liu ◽  
Xin Chen ◽  
Keji Zhao
Keyword(s):  
Chromatin Remodeling ◽  
Target Genes ◽  
Transcription Activator ◽  
Baf Complex ◽  
Antiproliferative Effects ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Maximal Induction ◽  
Antiproliferative Activities

ABSTRACT The mammalian SWI/SNF-like chromatin-remodeling BAF complex plays several important roles in controlling cell proliferation and differentiation. Interferons (IFNs) are key mediators of cellular antiviral and antiproliferative activities. In this report, we demonstrate that the BAF complex is required for the maximal induction of a subset of IFN target genes by alpha IFN (IFN-α). The BAF complex is constitutively associated with the IFITM3 promoter in vivo and facilitates the chromatin remodeling of the promoter upon IFN-α induction. Furthermore, we show that the ubiquitous transcription activator Sp1 interacts with the BAF complex in vivo and augments the BAF-mediated activation of the IFITM3 promoter. Sp1 binds constitutively to the IFITM3 promoter in the absence of the BAF complex, suggesting that it may recruit and/or stabilize the BAF complex binding to the IFITM3 promoter. Our results bring new mechanistic insights into the antiproliferative effects of the chromatin-remodeling BAF complex.

scholarly journals Analysis of mitogen-activated protein kinase pathways used by interleukin 1 in tissues in vivo: activation of hepatic c-Jun N-terminal kinases 1 and 2, and mitogen-activated protein kinase kinases 4 and 7

2001 ◽  
Vol 353 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Andrew FINCH ◽  
W. DAVIS ◽  
Wayne G. CARTER ◽  
Jeremy SAKLATVALA
Keyword(s):  
Protein Kinase ◽  
Cultured Cells ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Jnk Pathway ◽  
Mitogen Activated Protein ◽  
Jnk Isoforms ◽  
Fold Activation

The effects of interleukin 1 (IL-1) are mediated by the activation of protein kinase signalling pathways, which have been well characterized in cultured cells. We have investigated the activation of these pathways in rabbit liver and other tissues after the systemic administration of IL-1α. In liver there was 30Ő40-fold activation of c-Jun N-terminal kinase (JNK) and 5-fold activation of both JNK kinases, mitogen-activated protein kinase (MAPK) kinase (MKK)4 and MKK7. IL-1α also caused 2Ő3-fold activation of p38 MAPK and degradation of the inhibitor of nuclear factor κB (‘IκB’), although no activation of extracellular signal-regulated protein kinase (ERK) (p42/44 MAPK) was observed. The use of antibodies against specific JNK isoforms showed that, in liver, short (p46) JNK1 and long (p54) JNK2 are the predominant forms activated, with smaller amounts of long JNK1 and short JNK2. No active JNK3 was detected. A similar pattern of JNK activation was seen in lung, spleen, skeletal muscle and kidney. Significant JNK3 activity was detectable only in the brain, although little activation of the JNK pathway in response to IL-1α was observed in this tissue. This distribution of active JNK isoforms probably results from a different expression of JNKs within the tissues, rather than from a selective activation of isoforms. We conclude that IL-1α might activate a more restricted set of signalling pathways in tissues in vivo than it does in cultured cells, where ERK and JNK3 activation are often observed. Cultured cells might represent a ‘repair’ phenotype that undergoes a broader set of responses to the cytokine.

scholarly journals Novel genomic targets of valosin-containing protein in protecting pathological cardiac hypertrophy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ning Zhou ◽  
Xin Chen ◽  
Jing Xi ◽  
Ben Ma ◽  
Christiana Leimena ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Pressure Overload ◽  
Bioinformatic Analysis ◽  
Pathological Cardiac Hypertrophy ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Survival Signaling ◽  
G Protein Coupled

Abstract Pressure overload-induced cardiac hypertrophy, such as that caused by hypertension, is a key risk factor for heart failure. However, the underlying molecular mechanisms remain largely unknown. We previously reported that the valosin-containing protein (VCP), an ATPase-associated protein newly identified in the heart, acts as a significant mediator of cardiac protection against pressure overload-induced pathological cardiac hypertrophy. Still, the underlying molecular basis for the protection is unclear. This study used a cardiac-specific VCP transgenic mouse model to understand the transcriptomic alterations induced by VCP under the cardiac stress caused by pressure overload. Using RNA sequencing and comprehensive bioinformatic analysis, we found that overexpression of the VCP in the heart was able to normalize the pressure overload-stimulated hypertrophic signals by activating G protein-coupled receptors, particularly, the olfactory receptor family, and inhibiting the transcription factor controlling cell proliferation and differentiation. Moreover, VCP overexpression restored pro-survival signaling through regulating alternative splicing alterations of mitochondrial genes. Together, our study revealed a novel molecular regulation mediated by VCP under pressure overload that may bring new insight into the mechanisms involved in protecting against hypertensive heart failure.

FGF-induced lens cell proliferation and differentiation is dependent on MAPK (ERK1/2) signalling

Development ◽  
2001 ◽  
Vol 128 (24) ◽  
pp. 5075-5084 ◽  
Author(s):  
Frank J. Lovicu ◽  
John W. McAvoy
Keyword(s):  
Cell Proliferation ◽  
Morphological Changes ◽  
Specific Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Differentiation Markers ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Lens Fibre ◽  
Lens Cell

Members of the fibroblast growth factor (FGF) family induce lens epithelial cells to undergo cell division and differentiate into fibres; a low dose of FGF can stimulate cell proliferation (but not fibre differentiation), whereas higher doses of FGF are required to induce fibre differentiation. To determine if these cellular events are regulated by the same signalling pathways, we examined the role of mitogen-activated protein kinase (MAPK) signalling in FGF-induced lens cell proliferation and differentiation. We show that FGF induced a dose-dependent activation of extracellular regulated kinase 1/2 (ERK1/2) as early as 15 minutes in culture, with a high (differentiating) dose of FGF stimulating a greater level of ERK phosphorylation than a lower (proliferating) dose. Subsequent blocking experiments using UO126 (a specific inhibitor of ERK activation) showed that activation of ERK is required for FGF-induced lens cell proliferation and fibre differentiation. Interestingly, inhibition of ERK signalling can block the morphological changes associated with FGF-induced lens fibre differentiation; however, it cannot block the synthesis of some of the molecular differentiation markers, namely, β-crystallin. These findings are consistent with the in vivo distribution of the phosphorylated (active) forms of ERK1/2 in the lens. Taken together, our data indicate that different levels of ERK signalling may be important for the regulation of lens cell proliferation and early morphological events associated with fibre differentiation; however, multiple signalling pathways are likely to be required for the process of lens fibre differentiation and maturation.

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