Regulation of IκB kinase and NF-κB in contracting adult rat skeletal muscle

2005 ◽  
Vol 289 (4) ◽  
pp. C794-C801 ◽  
Author(s):  
Richard C. Ho ◽  
Michael F. Hirshman ◽  
Yangfeng Li ◽  
Dongsheng Cai ◽  
Jocelyn R. Farmer ◽  
...  

Nuclear factor-κB (NF-κB) is a transcription factor with important roles in regulating innate immune and inflammatory responses. NF-κB is activated through the phosphorylation of its inhibitor, IκB, by the IκB kinase (IKK) complex. Physical exercise elicits changes in skeletal muscle gene expression, yet signaling cascades and transcription factors involved remain largely unknown. To determine whether NF-κB signaling is regulated by exercise in vivo, rats were run on a motorized treadmill for 5–60 min. Exercise resulted in up to twofold increases in IKKα/β phosphorylation in the soleus and red gastrocnemius muscles throughout the time course studied. In red gastrocnemius muscles, NF-κB activity increased 50% 1–3 h after 60 min of treadmill exercise, returning to baseline by 5 h. Contraction of isolated extensor digitorum longus muscles in vitro increased IKKα/β phosphorylation sevenfold and this was accompanied by a parallel increase in IκBα phosphorylation. Additional kinases that are activated by exercise include p38, extracellular-signal regulated protein kinase (ERK), and AMP-activated protein kinase (AMPK). Inhibitors of p38 (SB-203580) and ERK (U-0126) blunted contraction-mediated IKK phosphorylation by 39 ± 4% ( P = 0.06) and 35 ± 10% ( P = 0.09), respectively, and in combination by 76 ± 5% ( P < 0.05), suggesting that these kinases might influence the activation of IKK and NF-κB during exercise. In contrast, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside, an activator of AMPK, had no effect on either IKK or NF-κB activity. In conclusion, acute submaximal exercise transiently stimulates NF-κB signaling in skeletal muscle. This activation is a local event because it can occur in the absence of exercise-derived systemic factors.

2022 ◽  
Author(s):  
Zhuo-yue Song ◽  
Mengru Zhu ◽  
Jun Wu ◽  
Tian Yu ◽  
Yao Chen ◽  
...  

The effects of Cucumaria frondosa polysaccharides (CFP) on renal interstitial fibrosis via regulating phosphatidylinositol-3-hydroxykinase/protein kinase-B/Nuclear factor-κB (PI3K/AKT/NF-κB) signaling pathway were investigated in vivo and in vitro in this research. A...


2020 ◽  
Vol 12 (524) ◽  
pp. eaax6601 ◽  
Author(s):  
Manoj Puthia ◽  
Marta Butrym ◽  
Jitka Petrlova ◽  
Ann-Charlotte Strömdahl ◽  
Madelene Å. Andersson ◽  
...  

There is a clinical need for improved wound treatments that prevent both infection and excessive inflammation. TCP-25, a thrombin-derived peptide, is antibacterial and scavenges pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide, thereby preventing CD14 interaction and Toll-like receptor dimerization, leading to reduced downstream immune activation. Here, we describe the development of a hydrogel formulation that was functionalized with TCP-25 to target bacteria and associated PAMP-induced inflammation. In vitro studies determined the polymer prerequisites for such TCP-25–mediated dual action, favoring the use of noncharged hydrophilic hydrogels, which enabled peptide conformational changes and LPS binding. The TCP-25–functionalized hydrogels killed Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacteria in vitro, as well as in experimental mouse models of subcutaneous infection. The TCP-25 hydrogel also mediated reduction of LPS-induced local inflammatory responses, as demonstrated by analysis of local cytokine production and in vivo bioimaging using nuclear factor κB (NF-κB) reporter mice. In porcine partial thickness wound models, TCP-25 prevented infection with S. aureus and reduced concentrations of proinflammatory cytokines. Proteolytic fragmentation of TCP-25 in vitro yielded a series of bioactive TCP fragments that were identical or similar to those present in wounds in vivo. Together, the results demonstrate the therapeutic potential of TCP-25 hydrogel, a wound treatment based on the body’s peptide defense, for prevention of both bacterial infection and the accompanying inflammation.


2004 ◽  
Vol 287 (2) ◽  
pp. C484-C493 ◽  
Author(s):  
Minenori Ishido ◽  
Katsuya Kami ◽  
Mitsuhiko Masuhara

MyoD, a myogenic regulatory factor, is rapidly expressed in adult skeletal muscles in response to denervation. However, the function(s) of MyoD expressed in denervated muscle has not been adequately elucidated. In vitro, it directly transactivates cyclin-dependent kinase inhibitor p21 (p21) and retinoblastoma protein (Rb), a downstream target of p21. These factors then act to regulate cell cycle withdrawal and antiapoptotic cell death. Using immunohistochemical approaches, we characterized cell types expressing MyoD, p21, and Rb and the relationship among these factors in the myonucleus of denervated muscles. In addition, we quantitatively examined the time course changes and expression patterns among distinct myofiber types of MyoD, p21, and Rb during denervation. Denervation induced MyoD expression in myonuclei and satellite cell nuclei, whereas p21 and Rb were found only in myonuclei. Furthermore, coexpression of MyoD, p21, and Rb was induced in the myonucleus, and quantitative analysis of these factors determined that there was no difference among the three myofiber types. These observations suggest that MyoD may function in myonuclei in response to denervation to protect against denervation-induced apoptosis via perhaps the activation of p21 and Rb, and function of MyoD expressed in satellite cell nuclei may be negatively regulated. The present study provides a molecular basis to further understand the function of MyoD expressed in the myonuclei and satellite cell nuclei of denervated skeletal muscle.


2002 ◽  
Vol 22 (10) ◽  
pp. 3549-3561 ◽  
Author(s):  
Ray-Chang Wu ◽  
Jun Qin ◽  
Yoshihiro Hashimoto ◽  
Jiemin Wong ◽  
Jianming Xu ◽  
...  

ABSTRACT In the past few years, many nuclear receptor coactivators have been identified and shown to be an integral part of receptor action. The most frequently studied of these coactivators are members of the steroid receptor coactivator (SRC) family, SRC-1, TIF2/GRIP1/SRC-2, and pCIP/ACTR/AIB-1/RAC-3/TRAM-1/SRC-3. In this report, we describe the biochemical purification of SRC-1 and SRC-3 protein complexes and the subsequent identification of their associated proteins by mass spectrometry. Surprisingly, we found association of SRC-3, but not SRC-1, with the IκB kinase (IKK). IKK is known to be responsible for the degradation of IκB and the subsequent activation of NF-κB. Since NF-κB plays a key role in host immunity and inflammatory responses, we therefore investigated the significance of the SRC-3-IKK complex. We demonstrated that SRC-3 was able to enhance NF-κB-mediated gene expression in concert with IKK. In addition, we showed that SRC-3 was phosphorylated by the IKK complex in vitro. Furthermore, elevated SRC-3 phosphorylation in vivo and translocation of SRC-3 from cytoplasm to nucleus in response to tumor necrosis factor alpha occurred in cells, suggesting control of subcellular localization of SRC-3 by phosphorylation. Finally, the hypothesis that SRC-3 is involved in NF-κB-mediated gene expression is further supported by the reduced expression of interferon regulatory factor 1, a well-known NF-κB target gene, in the spleens of SRC-3 null mutant mice. Taken together, our results not only reveal the IKK-mediated phosphorylation of SRC-3 to be a regulated event that plays an important role but also substantiate the role of SRC-3 in multiple signaling pathways.


2018 ◽  
Author(s):  
Po-Jen Chen ◽  
I-Ling Ko ◽  
Chia-Lin Lee ◽  
Hao-Chun Hu ◽  
Fang-Rong Chang ◽  
...  

AbstractNeutrophil activation has a pathogenic effect in inflammatory diseases. Protein kinase B (PKB)/AKT regulates diverse cellular responses. However, the significance of AKT in neutrophilic inflammation is still not well understood. Here, we identified CLLV-1 as a novel AKT inhibitor. CLLV-1 inhibited respiratory burst, degranulation, chemotaxis, and AKT phosphorylation in activated human neutrophils and dHL-60 cells. Significantly, CLLV-1 blocked AKT activity and covalently reacted with AKT Cys310 in vitro. The AKT309-313 peptide-CLLV-1 adducts were determined by NMR or mass spectrometry assay. The alkylation agent-conjugated AKT (reduced form) level was also inhibited by CLLV-1. Additionally, CLLV-1 ameliorated lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. CLLV-1 acts as a covalent allosteric AKT inhibitor by targeting AKT Cys310 to restrain inflammatory responses in human neutrophils and LPS-induced ALI in vivo. Our findings provide a mechanistic framework for redox modification of AKT that may serve as a novel pharmacological target to alleviate neutrophilic inflammation.


2020 ◽  
Author(s):  
Ozge Kizilay Mancini ◽  
David N Huynh ◽  
Liliane Menard ◽  
Dominique Shum-Tim ◽  
Huy Ong ◽  
...  

Abstract Aims Diabetes is a conventional risk factor for atherosclerotic cardiovascular disease and myocardial infarction (MI) is the most common cause of death among these patients. Mesenchymal stromal cells (MSCs) in patients with type 2 diabetes mellitus (T2DM) and atherosclerosis have impaired ability to suppress activated T-cells (i.e. reduced immunopotency). This is mediated by an inflammatory shift in MSC-secreted soluble factors (i.e. pro-inflammatory secretome) and can contribute to the reduced therapeutic effects of autologous T2DM and atherosclerosis-MSC post-MI. The signalling pathways driving the altered secretome of atherosclerosis- and T2DM-MSC are unknown. Specifically, the effect of IκB kinase β (IKKβ) modulation, a key regulator of inflammatory responses, on the immunopotency of MSCs from T2DM patients with advanced atherosclerosis has not been studied. Methods and results MSCs were isolated from adipose tissue obtained from patients with (i) atherosclerosis and T2DM (atherosclerosis+T2DM MSCs, n = 17) and (ii) atherosclerosis without T2DM (atherosclerosis MSCs, n = 17). MSCs from atherosclerosis+T2DM individuals displayed an inflammatory senescent phenotype and constitutively expressed active forms of effectors of the canonical IKKβ nuclear factor-κB transcription factors inflammatory pathway. Importantly, this constitutive pro-inflammatory IKKβ signature resulted in an altered secretome and impaired in vitro immunopotency and in vivo healing capacity in an acute MI model. Notably, treatment with a selective IKKβ inhibitor or IKKβ knockdown (KD) (clustered regularly interspaced short palindromic repeats/Cas9-mediated IKKβ KD) in atherosclerosis+T2DM MSCs reduced the production of pro-inflammatory secretome, increased survival, and rescued their immunopotency both in vitro and in vivo. Conclusions Constitutively active IKKβ reduces the immunopotency of atherosclerosis+T2DM MSC by changing their secretome composition. Modulation of IKKβ in atherosclerosis+T2DM MSCs enhances their myocardial repair ability.


Endocrinology ◽  
2014 ◽  
Vol 155 (6) ◽  
pp. 2254-2265 ◽  
Author(s):  
Guan-Ming Qi ◽  
Li-Xin Jia ◽  
Yu-Lin Li ◽  
Hui-Hua Li ◽  
Jie Du

Previous studies have indicated that adiponectin (APN) protects against cardiac remodeling, but the underlying mechanism remains unclear. The present study aimed to elucidate how APN regulates inflammatory responses and cardiac fibrosis in response to angiotensin II (Ang II). Male APN knockout (APN KO) mice and wild-type (WT) C57BL/6 littermates were sc infused with Ang II at 750 ng/kg per minute. Seven days after Ang II infusion, both APN KO and WT mice developed equally high blood pressure levels. However, APN KO mice developed more severe cardiac fibrosis and inflammation compared with WT mice. This finding was demonstrated by the up-regulation of collagen I, α-smooth muscle actin, IL-1β, and TNF-α and increased macrophage infiltration in APN KO mice. Moreover, there were substantially fewer microtubule-associated protein 1 light chain 3-positive autophagosomes in macrophages in the hearts of Ang II-infused APN KO mice. Additional in vitro studies also revealed that globular APN treatment induced autophagy, inhibited Ang II-induced nuclear factor-κB activity, and enhanced the expression of antiinflammatory cytokines, including IL-10, macrophage galactose N-acetyl-galactosamine specific lectin 2, found in inflammatory zone 1, and type-1 arginase in macrophages. In contrast, APN-induced autophagy and antiinflammatory cytokine expression was diminished in Atg5-knockdown macrophages or by Compound C, an inhibitor of adenosine 5′-monophosphate-activated protein kinase. Our study indicates that APN activates macrophage autophagy through the adenosine 5′-monophosphate-activated protein kinase pathway and suppresses Ang II-induced inflammatory responses, thereby reducing the extent of cardiac fibrosis.


2005 ◽  
Vol 201 (10) ◽  
pp. 1677-1687 ◽  
Author(s):  
Maria Grazia Ruocco ◽  
Shin Maeda ◽  
Jin Mo Park ◽  
Toby Lawrence ◽  
Li-Chung Hsu ◽  
...  

Transcription factor, nuclear factor κB (NF-κB), is required for osteoclast formation in vivo and mice lacking both of the NF-κB p50 and p52 proteins are osteopetrotic. Here we address the relative roles of the two catalytic subunits of the IκB kinase (IKK) complex that mediate NF-κB activation, IKKα and IKKβ, in osteoclast formation and inflammation-induced bone loss. Our findings point out the importance of the IKKβ subunit as a transducer of signals from receptor activator of NF-κB (RANK) to NF-κB. Although IKKα is required for RANK ligand-induced osteoclast formation in vitro, it is not needed in vivo. However, IKKβ is required for osteoclastogenesis in vitro and in vivo. IKKβ also protects osteoclasts and their progenitors from tumor necrosis factor α–induced apoptosis, and its loss in hematopoietic cells prevents inflammation-induced bone loss.


1998 ◽  
Vol 331 (1) ◽  
pp. 299-308 ◽  
Author(s):  
Kay S. WALKER ◽  
Maria DEAK ◽  
Andrew PATERSON ◽  
Kevin HUDSON ◽  
Philip COHEN ◽  
...  

The regulatory and catalytic properties of the three mammalian isoforms of protein kinase B (PKB) have been compared. All three isoforms (PKBα, PKBβ and PKBγ) were phosphorylated at similar rates and activated to similar extents by 3-phosphoinositide-dependent protein kinase-1 (PDK1). Phosphorylation and activation of each enzyme required the presence of PtdIns(3,4,5)P3 or PtdIns(3,4)P2, as well as PDK1. The activation of PKBβ and PKBγ by PDK1 was accompanied by the phosphorylation of the residues equivalent to Thr308 in PKBα, namely Thr309 (PKBβ) and Thr305 (PKBγ). PKBγ which had been activated by PDK1 possessed a substrate specificity identical with that of PKBα and PKBβ towards a range of peptides. The activation of PKBγ and its phosphorylation at Thr305 was triggered by insulin-like growth factor-1 in 293 cells. Stimulation of rat adipocytes or rat hepatocytes with insulin induced the activation of PKBα and PKBβ with similar kinetics. After stimulation of adipocytes, the activity of PKBβ was twice that of PKBα, but in hepatocytes PKBα activity was four-fold higher than PKBβ. Insulin induced the activation of PKBα in rat skeletal muscle in vivo, with little activation of PKBβ. Insulin did not induce PKBγ activity in adipocytes, hepatocytes or skeletal muscle, but PKBγ was the major isoform activated by insulin in rat L6 myotubes (a skeletal-muscle cell line).


2019 ◽  
Author(s):  
Hannah E. Wilson ◽  
David A. Stanton ◽  
Cortney Montgomery ◽  
Aniello M. Infante ◽  
Matthew Taylor ◽  
...  

ABSTRACTIncreased susceptibility to fatigue is a negative predictor of survival commonly experienced by women with breast cancer. Here, we sought to identify molecular changes induced in human skeletal muscle by BC regardless of treatment history or tumor molecular subtype using RNA-sequencing and proteomic analyses. Mitochondrial dysfunction was apparent across all molecular subtypes, with the greatest degree of transcriptomic changes occurring in women with HER2/neu-overexpressing tumors, though muscle from patients of all subtypes exhibited similar pathway-level dysregulation. Interestingly, we found no relationship between anti-cancer treatments and muscle gene expression, suggesting that fatigue is a product of BC per se rather than clinical history. In vitro and in vivo experimentation confirmed the ability of BC cells to alter mitochondrial function and ATP content in muscle. These data suggest that interventions supporting muscle in the presence of BC-induced mitochondrial dysfunction may alleviate fatigue and improve the lives of women with BC.


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