scholarly journals Caffeic Acid Inhibits RANKL and TNFa-induced Osteoclastogenesis by Targeting TAK1-p44/42 MAPK

2021 ◽  
Vol 13 (4) ◽  
pp. 433-7
Author(s):  
Ferry Sandra ◽  
Jennifer Putri ◽  
Hilary Limen ◽  
Blanca Sarizta

BACKGROUND: The potential of the caffeic acid in other important Receptor Activator Nuclear Factor kB Ligand (RANKL)-Tumor Necrosis Factor (TNF)a-induced osteoclastogenic signaling pathways has not been known. Therefore, the current study was conducted to explore as well as to understand the inhibition potential of caffeic acid.METHODS: RAW264.7 cells were cultured, treated with caffeic acid, RANKL and TNFa. Tartrate Resistant Acid Phosphatase (TRAP) staining was performed to detect TRAP+ osteoclast-like polynuclear cells. To detect the activity of p44/42 Mitogen Activated Protein Kinase (MAPK), Akt, and Transforming Growth Factor-β-activated Kinase (TAK)1, the phosphorylated forms of the proteins were investigated with the immunoblotting assay.RESULTS: Pre-treatment of caffeic acid inhibited the RANKL and TNFa-induced differentiation of RAW264.7 cells into TRAP+ osteoclast-like polynuclear cells. RANKL and TNFa induced phosphorylation of p44/42 MAPK at Thr202/Tyr204, phosphorylation of Akt at both Ser473 and Thr308 and phosphorylation of TAK1 at Ser412. Pre-treatment with caffeic acid prior to the RANKL and TNFa induction, inhibited the phosphorylation of MAPK, and TAK1, but not Akt.CONCLUSION: Caffeic acid might regulate the RANKL-TNFa-induced osteoclastogenic pathway in RAW264.7 by targeting TAK1, which later activation of p44/42 MAPK was abolished.KEYWORDS: caffeic acid, osteoclastogenesis, p44/42, Erk1/2, Akt, TAK1, RAW264.7 

2012 ◽  
Vol 124 (3) ◽  
pp. 191-202 ◽  
Author(s):  
Mona Sedeek ◽  
Alex Gutsol ◽  
Augusto C. Montezano ◽  
Dylan Burger ◽  
Aurelie Nguyen Dinh Cat ◽  
...  

Nox (NADPH oxidase)-derived ROS (reactive oxygen species) have been implicated in the development of diabetic nephropathy. Of the Nox isoforms in the kidney, Nox4 is important because of its renal abundance. In the present study, we tested the hypothesis that GKT136901, a Nox1/4 inhibitor, prevents the development of nephropathy in db/db (diabetic) mice. Six groups of male mice (8-week-old) were studied: (i) untreated control db/m, (ii) low-dose GKT136901-treated db/m (30 mg/kg of body weight per day), (iii) high-dose GKT136901-treated db/m (90 mg/kg of body weight per day), (iv) untreated db/db; (v) low dose GKT136901-treated db/db; and (vi) high-dose GKT136901-treated db/db. GKT136901, in chow, was administered for 16 weeks. db/db mice developed diabetes and nephropathy as evidenced by hyperglycaemia, albuminuria and renal injury (mesangial expansion, tubular dystrophy and glomerulosclerosis). GKT136901 treatment had no effect on plasma glucose or BP (blood pressure) in any of the groups. Plasma and urine TBARSs (thiobarbituric acid-reacting substances) levels, markers of systemic and renal oxidative stress, respectively, were increased in diabetic mice. Renal mRNA expression of Nox4, but not of Nox2, increased, Nox1 was barely detectable in db/db. Expression of the antioxidant enzyme SOD-1 (superoxide dismutase 1) decreased in db/db mice. Renal content of fibronectin, pro-collagen, TGFβ (transforming growth factor β) and VCAM-1 (vascular cell adhesion molecule 1) and phosphorylation of ERK1/2 (extracellular-signal-regulated kinase 1/2) were augmented in db/db kidneys, with no change in p38 MAPK (mitogen-activated protein kinase) and JNK (c-Jun N-terminal kinase). Treatment reduced albuminuria, TBARS and renal ERK1/2 phosphorylation and preserved renal structure in diabetic mice. Our findings suggest a renoprotective effect of the Nox1/4 inhibitor, possibly through reduced oxidative damage and decreased ERK1/2 activation. These phenomena occur independently of improved glucose control, suggesting GKT136901-sensitive targets are involved in complications of diabetes rather than in the disease process.


2012 ◽  
Vol 23 (18) ◽  
pp. 3731-3742 ◽  
Author(s):  
Jessica L. Allen ◽  
Margaret E. Cooke ◽  
Tamara Alliston

Cells encounter physical cues such as extracellular matrix (ECM) stiffness in a microenvironment replete with biochemical cues. However, the mechanisms by which cells integrate physical and biochemical cues to guide cellular decision making are not well defined. Here we investigate mechanisms by which chondrocytes generate an integrated response to ECM stiffness and transforming growth factor β (TGFβ), a potent agonist of chondrocyte differentiation. Primary murine chondrocytes and ATDC5 cells grown on 0.5-MPa substrates deposit more proteoglycan and express more Sox9, Col2α1, and aggrecan mRNA relative to cells exposed to substrates of any other stiffness. The chondroinductive effect of this discrete stiffness, which falls within the range reported for articular cartilage, requires the stiffness-sensitive induction of TGFβ1. Smad3 phosphorylation, nuclear localization, and transcriptional activity are specifically increased in cells grown on 0.5-MPa substrates. ECM stiffness also primes cells for a synergistic response, such that the combination of ECM stiffness and exogenous TGFβ induces chondrocyte gene expression more robustly than either cue alone through a p38 mitogen-activated protein kinase–dependent mechanism. In this way, the ECM stiffness primes the TGFβ pathway to efficiently promote chondrocyte differentiation. This work reveals novel mechanisms by which cells integrate physical and biochemical cues to exert a coordinated response to their unique cellular microenvironment.


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