scholarly journals MicroRNA-218 Negatively Regulates Osteoclastogenic Differentiation by Repressing the Nuclear Factor-κB Signaling Pathway and Targeting Tumor Necrosis Factor Receptor 1

2018 ◽  
Vol 48 (1) ◽  
pp. 339-347 ◽  
Author(s):  
Weiwei Wang ◽  
Lei Yang ◽  
Dan Zhang ◽  
Chao Gao ◽  
Jie Wu ◽  
...  
Keyword(s):  
Bioinformatics Analysis ◽  
Tumor Necrosis Factor Receptor ◽  
Nuclear Factor Κb ◽  
Raw 264.7 Cells ◽  
Luciferase Reporter ◽  
Raw 264.7 ◽  
Nuclear Factor ◽  
Reporter Assay ◽  
Trap Staining ◽  
Necrosis Factor

Background/Aims: Postmenopausal osteoporosis is a common disease associated with estrogen deficiency leading to bone loss and bone tissue changes. The resultant bone fragility and increased risk of fracture has serious adverse effects on health and quality of life of the elderly, making it an important health issue. MicroRNA-218 (miR-218) is closely related to the development of osteoporosis. In this study, we investigated the regulatory mechanisms of miR-218 in osteoclastogenesis. Methods: We investigated miR-218 levels on differentiation of RAW 264.7 cells into osteoclasts compared with normal cells. Next, RAW 264.7 cells were transfected with miR-218 mimics or inhibitors to study the role of miR-218 in osteoclastogenic differentiation. Tartrate-resistant acid phosphatase (TRAP) staining was performed to determine osteoclastogenic differentiation. Bioinformatics analysis and luciferase reporter assay were used to identify and validate miR-218 target genes. Results: miR-218 was downregulated following RAW 264.7 cell differentiation into osteoclasts. miR-218 overexpression attenuated osteoclast differentiation, whereas low miR-218 expression promoted it as demonstrated by increased expression of osteoclast-specific genes and TRAP staining. Bioinformatics analysis and the luciferase reporter assay showed that tumor necrosis factor receptor 1 (TNFR1), a cell membrane receptor of TNF (TNF is an activator of nuclear factor-κB [NF-κB]), is a direct target of miR-218. Conclusions: Our findings indicate that miR-218 regulates osteoclastogenic differentiation negatively by repressing NF-κB signaling by targeting TNFR1, suggesting that targeting miR-218 may be a therapeutic approach in postmenopausal osteoporosis.

scholarly journals JFC1 is transcriptionally activated by nuclear factor-κB and up-regulated by tumour necrosis factor α in prostate carcinoma cells

2002 ◽  
Vol 367 (3) ◽  
pp. 791-799 ◽  
Author(s):  
Sergio D. CATZ ◽  
Bernard M. BABIOR ◽  
Jennifer L. JOHNSON
Keyword(s):  
Tumour Necrosis Factor ◽  
Cell Lines ◽  
Prostate Carcinoma ◽  
Tumour Necrosis ◽  
Nuclear Factor Κb ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Tumour Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

The human promoter region of JFC1, a phosphatidylinositol 3,4,5-trisphosphate binding ATPase, was isolated by amplification of a 549bp region upstream of the jfc1 gene by the use of a double-PCR system. By primer extension analysis we mapped the transcription initiation site at nucleotide −321 relative to the translation start site. Putative regulatory elements were identified in the jfc1 TATA-less promoter, including three consensus sites for nuclear factor-κB (NF-κB). We analysed the three putative NF-κB binding sites by gel retardation and supershift assays. Each of the putative NF-κB sites interacted specifically with recombinant NF-κB p50, and the complexes co-migrated with those formed by the NF-κB consensus sequence and p50. An antibody to p50 generated a supershifted complex for these NF-κB sites. These sites formed specific complexes with nuclear proteins from tumour necrosis factor α (TNFα)-treated WEHI 231 cells, which were supershifted with antibodies against p50 and p65. The jfc1 promoter was transcriptionally active in various cell lines, as determined by luciferase reporter assays following transfection with a jfc1 promoter luciferase vector. Co-transfection with NF-κB expression vectors or stimulation with TNFα resulted in significant transactivation of the jfc1 promoter construct, although transactivation of a mutated jfc1 promoter was negligible. The expression of a dominant negative IκB (inhibitor κB) decreased basal jfc1 promoter activity. The cell lines PC-3, LNCaP and DU-145, but not Epstein—Barr virus-transformed lymphocytes, showed a dramatic increase in the expression of JFC1 after treatment with TNFα, suggesting that transcriptional activation of JFC1 by the TNFα/NF-κB pathway is significant in prostate carcinoma cell lines.

scholarly journals ZDHHC11 Positively Regulates NF-κB Activation by Enhancing TRAF6 Oligomerization

2021 ◽  
Vol 9 ◽  
Author(s):  
Enping Liu ◽  
Jiawei Sun ◽  
Jing Yang ◽  
Lin Li ◽  
Qili Yang ◽  
...  
Keyword(s):  
Virus Infection ◽  
Ubiquitin Ligase ◽  
Tumor Necrosis ◽  
Molecular Mechanisms ◽  
Tumor Necrosis Factor Receptor ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Dna Virus ◽  
Positive Modulator ◽  
Necrosis Factor

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a RING domain ubiquitin ligase that plays an important role in nuclear factor-κB (NF-κB) signaling by regulating activation of the TAK1 and IKK complexes. However, the molecular mechanisms that regulate TRAF6 E3 activity remain unclear. Here, we found that ZDHHC11, a member of the DHHC palmitoyl transferase family, functions as a positive modulator in NF-κB signaling. ZDHHC11 overexpression activated NF-κB, whereas ZDHHC11 deficiency impaired NF-κB activity stimulated by IL-1β, LPS, and DNA virus infection. Furthermore, Zdhhc11 knockout mice had a lower level of serum IL6 upon treatment with LPS and D-galactosamine or HSV-1 infection than control mice. Mechanistically, ZDHHC11 interacted with TRAF6 and then enhanced TRAF6 oligomerization, which increased E3 activity of TRAF6 for synthesis of K63-linked ubiquitination chains. Collectively, our study indicates that ZDHHC11 positively regulates NF-κB signaling by promoting TRAF6 oligomerization and ligase activity, subsequently activating TAK1 and IKK complexes.

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