scholarly journals IKK/NF-κB regulates skeletal myogenesis via a signaling switch to inhibit differentiation and promote mitochondrial biogenesis

2008 ◽  
Vol 180 (4) ◽  
pp. 787-802 ◽  
Author(s):  
Nadine Bakkar ◽  
Jingxin Wang ◽  
Katherine J. Ladner ◽  
Huating Wang ◽  
Jason M. Dahlman ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Metabolic Stress ◽  
Nuclear Factor Κb ◽  
Classical Pathway ◽  
Nuclear Factor ◽  
Mitochondrial Content ◽  
Muscle Disorders ◽  
Myotube Formation ◽  
Skeletal Muscle Disorders ◽  
And Function

Nuclear factor κB (NF-κB) is involved in multiple skeletal muscle disorders, but how it functions in differentiation remains elusive given that both anti- and promyogenic activities have been described. In this study, we resolve this by showing that myogenesis is controlled by opposing NF-κB signaling pathways. We find that myogenesis is enhanced in MyoD-expressing fibroblasts deficient in classical pathway components RelA/p65, inhibitor of κB kinase β (IKKβ), or IKKγ. Similar increases occur in myoblasts lacking RelA/p65 or IKKβ, and muscles from RelA/p65 or IKKβ mutant mice also contain higher fiber numbers. Moreover, we show that during differentiation, classical NF-κB signaling decreases, whereas the induction of alternative members IKKα, RelB, and p52 occurs late in myogenesis. Myotube formation does not require alternative signaling, but it is important for myotube maintenance in response to metabolic stress. Furthermore, overexpression or knockdown of IKKα regulates mitochondrial content and function, suggesting that alternative signaling stimulates mitochondrial biogenesis. Together, these data reveal a unique IKK/NF-κB signaling switch that functions to both inhibit differentiation and promote myotube homeostasis.

scholarly journals MiR 208a Regulates Mitochondrial Biogenesis in Metabolically Challenged Cardiomyocytes

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3152
Author(s):  
Naveen Mekala ◽  
Jacob Kurdys ◽  
Alexis Paige Vicenze ◽  
Leana Rose Weiler ◽  
Carmen Avramut ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Protein Trafficking ◽  
Cardiac Contractility ◽  
Metabolic Stress ◽  
Mitochondrial Translation ◽  
Human Cardiomyocytes ◽  
Bioenergetic Metabolism ◽  
Mitochondrial Defects ◽  
And Function ◽  
High Albumin

Metabolic syndrome increases the risk for cardiovascular disease including metabolic cardiomyopathy that may progress to heart failure. The decline in mitochondrial metabolism is considered a critical pathogenic mechanism that drives this progression. Considering its cardiac specificity, we hypothesized that miR 208a regulates the bioenergetic metabolism in human cardiomyocytes exposed to metabolic challenges. We screened in silico for potential miR 208a targets focusing on mitochondrial outcomes, and we found that mRNA species for mediator complex subunit 7, mitochondrial ribosomal protein 28, stanniocalcin 1, and Sortin nexin 10 are rescued by the CRISPR deletion of miR 208a in human SV40 cardiomyocytes exposed to metabolic challenges (high glucose and high albumin-bound palmitate). These mRNAs translate into proteins that are involved in nuclear transcription, mitochondrial translation, mitochondrial integrity, and protein trafficking. MiR 208a suppression prevented the decrease in myosin heavy chain α isoform induced by the metabolic stress suggesting protection against a decrease in cardiac contractility. MiR 208a deficiency opposed the decrease in the mitochondrial biogenesis signaling pathway, mtDNA, mitochondrial markers, and respiratory properties induced by metabolic challenges. The benefit of miR 208a suppression on mitochondrial function was canceled by the reinsertion of miR 208a. In summary, miR 208a regulates mitochondrial biogenesis and function in cardiomyocytes exposed to diabetic conditions. MiR 208a may be a therapeutic target to promote mitochondrial biogenesis in chronic diseases associated with mitochondrial defects.

scholarly journals Suppressive effects of dehydroepiandrosterone and the nuclear factor-κB inhibitor parthenolide on corticotroph tumor cell growth and function in vitro and in vivo

2006 ◽  
Vol 188 (2) ◽  
pp. 321-331 ◽  
Author(s):  
T Taguchi ◽  
T Takao ◽  
Y Iwasaki ◽  
M Nishiyama ◽  
K Asaba ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Survivin Expression ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Aging Effects ◽  
And Function

Dehydroepiandrosterone (DHEA) is believed to have an anti-tumor effect, as well as anti-inflammatory, antioxidant, and anti-aging effects. To clarify the possible inhibitory action of DHEA on pituitary tumor cells, we tested the effects of DHEA, alone or in combination with the nuclear factor-κB (NF-κB) inhibitor parthenolide (PRT), on AtT20 corticotroph cell growth and function both in vitro and in vivo. We found that, in vitro, DHEA and PRT had potent inhibitory effects on pro-opiomelanocortin and NF-κB-dependent gene expression. They also suppressed the transcription activity of survivin, a representative anti-apoptotic factor, and induced apoptosis in this cell line. Furthermore, using BALB/C nude mice with xenografts of AtT20 cells in vivo, we found that the combined administration of DHEA and PRT significantly attenuated tumor growth and survivin expression. The treatment also decreased the elevated plasma corticosterone levels and ameliorated the malnutrition induced by tumor growth. Altogether, these results suggested that combined treatments of DHEA and PRT potently inhibit the growth and function of corticotroph tumor cells both in vitro and in vivo. This effect may, at least partly, be caused by the suppressive effects of these compounds, such as survivin and other inhibitor of apoptosis proteins, on NF-κB-mediated gene transcription.

scholarly journals Endogenous Collagenases Regulate Osteoclast Fusion

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 705
Author(s):  
Hyo Jeong Kim ◽  
Youngkyun Lee
Keyword(s):  
Present Report ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Extracellular Signal ◽  
Mouse Bone Marrow Macrophage ◽  
Collagenase Inhibition ◽  
And Function

The precise regulation of osteoclast differentiation and function is crucial for the maintenance of healthy bone. Despite several reports of collagenase expression in bone tissues, the precise isoform expression as well as the role in osteoclasts are still unclear. In the present report, the expression of matrix metalloprotease (MMP)8 and MMP13 was confirmed in mouse bone marrow macrophage osteoclast precursors. The mRNA and protein expressions of both collagenases were significantly reduced by receptor activator of nuclear factor κB ligand (RANKL) stimulation. Notably, either inhibition of MMP expression by siRNA or treatment of cells with collagenase inhibitor Ro 32-3555 significantly augmented osteoclast fusion and resorption activity without affecting the osteoclast number. The inhibition of collagenase by Ro 32-3555 increased the expression of osteoclast fusion genes, Atp6v0d2 and Dcstamp, without affecting nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) protein expression. The enhanced osteoclast fusion by collagenase inhibition appears to be mediated through an extracellular signal regulated kinase (ERK)-dependent pathway. Collectively, these data provide novel information on the regulation of osteoclast fusion process.

scholarly journals An acetylation rheostat for the control of muscle energy homeostasis

2013 ◽  
Vol 51 (3) ◽  
pp. T101-T113 ◽  
Author(s):  
Keir Menzies ◽  
Johan Auwerx
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Biogenesis ◽  
Energy Homeostasis ◽  
Cellular Stress ◽  
Metabolic Stress ◽  
Effector Proteins ◽  
The Body ◽  
Recent Developments ◽  
And Function

In recent years, the role of acetylation has gained ground as an essential modulator of intermediary metabolism in skeletal muscle. Imbalance in energy homeostasis or chronic cellular stress, due to diet, aging, or disease, translate into alterations in the acetylation levels of key proteins which govern bioenergetics, cellular substrate use, and/or changes in mitochondrial content and function. For example, cellular stress induced by exercise or caloric restriction can alter the coordinated activity of acetyltransferases and deacetylases to increase mitochondrial biogenesis and function in order to adapt to low energetic levels. The natural duality of these enzymes, as metabolic sensors and effector proteins, has helped biologists to understand how the body can integrate seemingly distinct signaling pathways to control mitochondrial biogenesis, insulin sensitivity, glucose transport, reactive oxygen species handling, angiogenesis, and muscle satellite cell proliferation/differentiation. Our review will summarize the recent developments related to acetylation-dependent responses following metabolic stress in skeletal muscle.

scholarly journals Spi-C positively regulates RANKL-mediated osteoclast differentiation and function

2020 ◽  
Vol 52 (4) ◽  
pp. 691-701 ◽  
Author(s):  
Eun Mi Go ◽  
Ju Hee Oh ◽  
Jin Hee Park ◽  
Soo Young Lee ◽  
Na Kyung Lee
Keyword(s):  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mitogen Activated Protein Kinase ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Specific Domain ◽  
Receptor Activator ◽  
And Function

Abstract Spi-C is an SPI-group erythroblast transformation-specific domain transcription factor expressed during B-cell development. Here, we report that Spi-C is a novel receptor activator of nuclear factor-κB ligand (RANKL)-inducible protein that positively regulates RANKL-mediated osteoclast differentiation and function. Knockdown of Spi-C decreased the expression of RANKL-induced nuclear factor of activated T-cells, cytoplasmic 1, receptor activator of nuclear factor-κB (RANK), and tartrate-resistant acid phosphatase (TRAP), resulting in a marked decrease in the number of TRAP-positive multinucleated cells. Spi-C-transduced bone marrow-derived monocytes/macrophages (BMMs) displayed a significant increase in osteoclast formation in the presence of RANKL. In addition, Spi-C-depleted cells failed to show actin ring formation or bone resorption owing to a marked reduction in the expression of RANKL-mediated dendritic cell-specific transmembrane protein and the d2 isoform of vacuolar (H+) ATPase V0 domain, which are known osteoclast fusion-related genes. Interestingly, RANKL stimulation induced the translocation of Spi-C from the cytoplasm into the nucleus during osteoclastogenesis, which was specifically blocked by inhibitors of p38 mitogen-activated protein kinase (MAPK) or PI3 kinase. Moreover, Spi-C depletion prevented RANKL-induced MAPK activation and the degradation of inhibitor of κB-α (IκBα) in BMMs. Collectively, these results suggest that Spi-C is a novel positive regulator that promotes both osteoclast differentiation and function.

scholarly journals Role of NF-κB in Platelet Function

2019 ◽  
Vol 20 (17) ◽  
pp. 4185 ◽  
Author(s):  
Kevin Kojok ◽  
Abed El-Hakim El-Kadiry ◽  
Yahye Merhi
Keyword(s):  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Primary Hemostasis ◽  
Physiological Processes ◽  
Coronary Diseases ◽  
Blood Clots ◽  
Inflammatory State ◽  
Vascular Endothelia ◽  
And Function

Platelets are megakaryocyte-derived fragments lacking nuclei and prepped to maintain primary hemostasis by initiating blood clots on injured vascular endothelia. Pathologically, platelets undergo the same physiological processes of activation, secretion, and aggregation yet with such pronouncedness that they orchestrate and make headway the progression of atherothrombotic diseases not only through clot formation but also via forcing a pro-inflammatory state. Indeed, nuclear factor-κB (NF-κB) is largely implicated in atherosclerosis and its pathological complication in atherothrombotic diseases due to its transcriptional role in maintaining pro-survival and pro-inflammatory states in vascular and blood cells. On the other hand, we know little on the functions of platelet NF-κB, which seems to function in other non-genomic ways to modulate atherothrombosis. Therein, this review will resemble a rich portfolio for NF-κB in platelets, specifically showing its implications at the levels of platelet survival and function. We will also share the knowledge thus far on the effects of active ingredients on NF-κB in general, as an extrapolative method to highlight the potential therapeutic targeting of NF-κB in coronary diseases. Finally, we will unzip a new horizon on a possible extra-platelet role of platelet NF-κB, which will better expand our knowledge on the etiology and pathophysiology of atherothrombosis.

scholarly journals Mitf Induction by RANKL Is Critical for Osteoclastogenesis

2010 ◽  
Vol 21 (10) ◽  
pp. 1763-1771 ◽  
Author(s):  
Ssu-Yi Lu ◽  
Mengtao Li ◽  
Yi-Ling Lin
Keyword(s):  
Expression Profiles ◽  
Nuclear Factor Κb ◽  
Current Theory ◽  
Nuclear Factor ◽  
Binding Partner ◽  
Cell Lineages ◽  
Receptor Activator ◽  
And Function ◽  
Target Promoters ◽  
Distinct Role

Microphthalmia-associated transcription factor (Mitf) regulates the development and function of several cell lineages, including osteoclasts. In this report, we identified a novel mechanism by which RANKL regulates osteoclastogenesis via induction of Mitf isoform E (Mitf-E). Both Mitf-A and Mitf-E are abundantly present in osteoclasts. Unlike Mitf-A, which is ubiquitously expressed and is present in similar amounts in macrophages and osteoclasts, Mitf-E is almost nondetectable in macrophages, but its expression is significantly up-regulated during osteoclastogenesis. In addition to their different expression profiles, the two isoforms are drastically different in their abilities to support osteoclastogenesis, despite sharing all known functional domains. Unlike Mitf-A, small amounts of Mitf-E are present in nuclear lysates unless chromatin is digested/sheared during the extraction. Based on these data, we propose a model in which Mitf-E is induced during osteoclastogenesis and is closely associated with chromatin to facilitate its interaction with target promoters; therefore, Mitf-E has a stronger osteoclastogenic activity. Mitf-A is a weaker osteoclastogenic factor, but activated Mitf-A alone is not sufficient to fully support osteoclastogenesis. Therefore, this receptor activator for nuclear factor-κB ligand (RANKL)-induced Mitf phenomenon seems to play an important role during osteoclastogenesis. Although the current theory indicates that Mitf and its binding partner Tfe3 are completely redundant in osteoclasts, using RNA interference, we demonstrated that Mitf has a distinct role from Tfe3. This study provides the first evidence that RANKL-induced Mitf is critical for osteoclastogenesis and Mitf is not completely redundant with Tfe3.

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