scholarly journals High glucose alone, as well as in combination with proinflammatory cytokines, stimulates nuclear factor kappa-B-mediated transcription in hepatocytes in vitro

2007 ◽  
Vol 21 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Yasumasa Iwasaki ◽  
Machiko Kambayashi ◽  
Masato Asai ◽  
Masanori Yoshida ◽  
Takeshi Nigawara ◽  
...  
2020 ◽  
Vol 19 (2) ◽  
pp. 164-171
Author(s):  
Feng Xue ◽  
Tingting Chen

Glioblastoma multiforme is the most common malignancy of central nervous system. Herein we have evaluated the effect of L-tetrahydropalmatine, an isoquinoline alkaloid, on the tumor growth both in vivo and in vitro using C6 glioblastoma multiforme cells and BALB/c mice injected subcutaneously with C6/luc2 cells. The results of these studies show that L-tetrahydropalmatine exhibited cytotoxic effect on C6 glioblastoma multiforme cells, suppressed nuclear factor-kappa B activity, suppressed the levels of tumor-linked proteins such as matrix metalloproteinase-2/9, Cyclin-D1, vascular endothelial growth factor, and X-linked inhibitor of apoptosis protein via ERK/nuclear factor-kappa B cascade. Further, L-tetrahydropalmatine inhibited the cell migration and invasion properties of C6 cells, and also suppressed the tumor weight and volume in mice. Immunohistochemical staining of tumor tissues suggested that L-tetrahydropalmatine inhibited the extracellular-signal-regulated kinase/nuclear factor-kappa B cascade and suppressed the levels of Cyclin-D1; matrix metalloproteinase-2/9; X-linked inhibitor of apoptosis protein; and vascular endothelial growth factor, and also the progression and growth of glioblastoma multiforme in mice. In summary, L-tetrahydropalmatine inhibits the ERK/nuclear factor-kappa B cascade, decreases the tumor volume, and inhibits the proteins responsible for tumor growth both in vivo and in vitro.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Naren Bao ◽  
Bing Tang ◽  
Junke Wang

Acute kidney injury (AKI) is one of the most common and troublesome perioperative complications. Dexmedetomidine (DEX) is a potent α2-adrenoceptor (α2-AR) agonist with anti-inflammatory and renoprotective effects. In this study, a rat renal ischemia–reperfusion injury (IRI) model was induced. At 24 h after reperfusion, the IRI-induced damage and the renoprotection of DEX preconditioning were confirmed both biochemically and histologically. Changes in nuclear factor-kappa B (NF-κB), as well as its downstream anti-inflammatory factor A20 and proinflammatory factor tumor necrosis factor-α (TNF-α), were detected. Atipamezole, a nonselective antagonist, was then added 5 min before the administration of DEX to further analyze DEX’s effects on NF-κB, and another anti-inflammatory medicine, methylprednisolone, was used in comparison with DEX, to further analyze DEX’s effects on NF-κB. Different concentrations of DEX (0 nM, 0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM, and 10 μM) were applied to preincubated human renal tubular epithelial cell line (HK-2) cells in vitro. After anoxia and reoxygenation, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay and enzyme-linked immunosorbent assay (ELISA) were performed to evaluate the levels of NF-κB downstream anti-inflammatory cytokines. The results showed that, unlike methylprednisolone, DEX preconditioning led to a time-dependent biphasic change (first activation then inhibition) of NF-κB in the rat renal IRI models that were given 25 μg/kg i.p. It was accompanied by a similarly biphasic change of TNF-α and an early and persistent upregulation of A20. In vitro, DEX’s cellular protection showed a concentration-dependent biphasic change which was protective within the range of 0 to 100 nM but became opposite when concentrations are greater than 1 μM. The changes in the A20 and NF-κB messenger RNA (mRNA) levels were consistent with the renoprotective ability of DEX. In other words, DEX preconditioning protected the rats from renal IRI via regulation biphasic change of NF-κB signaling.


2020 ◽  
Vol 245 (9) ◽  
pp. 785-796
Author(s):  
Satyanarayana Alleboina ◽  
Thomas Wong ◽  
Madhu V Singh ◽  
Ayotunde O Dokun

Peripheral artery disease (PAD) is a major health problem and is caused by atherosclerosis in arteries outside the heart leading to impaired blood flow. The presence of diabetes significantly increases the likelihood of having worse outcomes in PAD, and the molecular mechanisms involved are poorly understood. Hyperglycemia in diabetes activates the nuclear factor-kappa B (NF-κB) pathway, and chronic inflammation in diabetes is associated with vascular complications. Ischemia also activates NF-κB signaling that is important for perfusion recovery in experimental PAD. We hypothesized that prolonged exposure of endothelial cells to high glucose in diabetes impairs ischemic activation of the NF-κB pathway and contributes to poor perfusion recovery in experimental PAD. We assessed the effect of high glucose and ischemia on canonical and non-canonical NF-κB activation in endothelial cells and found both conditions activate both pathways. However, exposure of endothelial cells to high glucose impairs ischemia-induced activation of the canonical NF-κB pathway but not the non-canonical pathway. We probed an array of antibodies against signaling proteins in the NF-κB pathway to identify proteins whose phosphorylation status are altered in endothelial cells exposed to high glucose. Protein kinase C beta (PKCβ) was among the proteins identified, and its role in impaired ischemia-induced activation of NF-κB during hyperglycemia has not been previously described. Inhibition of PKCβ improves ischemia-induced NF-κB activation in vitroand in vivo. It also improves perfusion recovery in diabetic mice following experimental PAD. Thus, in diabetes, PKCβ phosphorylation contributes to impaired ischemic activation of NF-κB and likely a mechanism contributing to poor PAD outcomes. Impact statement Diabetes worsens the outcomes of peripheral arterial disease (PAD) likely in part through inducing chronic inflammation. However, in PAD, recovery requires the nuclear factor-kappa B (NF-κB) activation, a known contributor to inflammation. Our study shows that individually, both ischemia and high glucose activate the canonical and non-canonical arms of the NF-κB pathways. We show for the first time that prolonged high glucose specifically impairs ischemia-induced activation of the canonical NF-κB pathway through activation of protein kinase C beta (PKCβ). Accordingly, inhibition of PKCβ restores the ischemia-induced NF-κB activity both in vitroin endothelial cells and in vivoin hind limbs of type 1 diabetic mice and improves perfusion recovery after experimental PAD. Thus, this study provides a mechanistic insight into how diabetes contributes to poor outcomes in PAD and a potential translational approach to improve PAD outcomes.


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