scholarly journals Modulation of IL-6 Expression by KLF4-Mediated Transactivation and PCAF-Mediated Acetylation in Sublytic C5b-9-Induced Rat Glomerular Mesangial Cells

2022 ◽  
Vol 12 ◽  
Author(s):  
Lu Xia ◽  
Yu Liu ◽  
Zhiwei Zhang ◽  
Yajuan Gong ◽  
Tianyi Yu ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Rat Model ◽  
Mesangial Cells ◽  
Histone H3 ◽  
Lysine Residue ◽  
Regulatory Mechanisms ◽  
Glomerular Mesangial Cells ◽  
Mesangial Proliferative Glomerulonephritis ◽  
Histone H2b ◽  
Inflammatory Damage

Interleukin-6 (IL-6) overproduction has been considered to contribute to inflammatory damage of glomerular mesangial cells (GMCs) in human mesangial proliferative glomerulonephritis (MsPGN) and its rat model called Thy-1 nephritis (Thy-1N). However, the regulatory mechanisms of IL-6 expression in GMCs upon sublytic C5b-9 timulation remain poorly understood. We found that Krüppel-like factor 4 (KLF4) bound to the IL-6 promoter (−618 to −126 nt) and activated IL-6 gene transcription. Furthermore, lysine residue 224 of KLF4 was acetylated by p300/CBP-associated factor (PCAF), which was important for KLF4-mediated transactivation. Moreover, lysine residue 5 on histone H2B and lysine residue 9 on histone H3 at the IL-6 promoter were also acetylated by PCAF, which resulted in an increase in IL-6 transcription. Besides, NF-κB activation promoted IL-6 expression by elevating the expression of PCAF. Overall, these findings suggest that sublytic C5b-9-induced the expression of IL-6 involves KLF4-mediated transactivation, PCAF-mediated acetylation of KLF4 and histones, and NF-κB activation in GMCs.

scholarly journals Regulation of nuclear factor kappaB by corticosteroids in rat mesangial cells.

1998 ◽  
Vol 9 (9) ◽  
pp. 1620-1628
Author(s):  
R B Auwardt ◽  
S J Mudge ◽  
C G Chen ◽  
D A Power
Keyword(s):  
Mesangial Cells ◽  
Kidney Diseases ◽  
Binding Activity ◽  
Proliferative Glomerulonephritis ◽  
Nuclear Factor Kappab ◽  
Nuclear Factor ◽  
Glomerular Mesangial Cells ◽  
Mesangial Proliferative Glomerulonephritis ◽  
Interleukin 1Beta ◽  
Nf Kappab

Nuclear factor kappaB (NF-kappaB) is one of the most important proinflammatory transcription factors. The anti-inflammatory activity of steroids in leukocytes is partly due to inhibition of signaling by NF-kappaB, but it is not known whether steroids inhibit NF-kappaB in kidney cells. Since the mesangial cell is important in several kidney diseases, especially mesangial proliferative glomerulonephritis, the aims of this study were: (1) to define the mechanism of NF-kappaB activation in rat glomerular mesangial cells; and (2) to determine whether steroids inhibit activation of NF-kappaB in these cells. Electrophoretic mobility shift assays (EMSA) showed that interleukin-1beta and tumor necrosis factor-alpha activated NF-kappaB from 15 min to 48 h after stimulation. Supershift EMSA demonstrated that p65 and p50 were the predominant subunits involved. Degradation of the inhibitory subunit IkappaB-alpha was first observed 15 min after stimulation by Western blot, was maximal at 15 to 30 min (>90% by densitometry), and had returned to near normal levels at 90 min. In contrast, IkappaB-beta was maximally degraded at 60 to 120 min and was still reduced at 48 h (<50% of the untreated level). Although treatment of mesangial cells with dexamethasone increased IkappaB-alpha mRNA by 1.92x and protein by 1.45x over controls, pretreatment did not inhibit degradation of IkappaB-alpha or -beta in response to stimulation, or prevent the increase in NF-kappaB binding activity shown by EMSA. However, dexamethasone significantly inhibited the increase in monocyte chemoattractant protein-1 mRNA seen after stimulation with interleukin 1beta, although this was not complete. It did not reduce transcription of an NF-kappaB reporter. In comparison, the pyrrolidine derivative of dithiocarnamate (PDTC), a known inhibitor of NF-kappaB, prevented the increase in NF-kappaB binding activity and significantly reduced transcription of the NF-kappaB reporter. These studies suggest that steroids can partially inhibit transcriptional activation by NF-kappaB in mesangial cells but not through an increase in IkappaB-alpha protein alone. Their effect must occur at the promoter and may be restricted to some NF-kappaB-responsive genes. Therapies that block NF-kappaB more effectively than steroids in mesangial cells, therefore, may be useful in the treatment of mesangial proliferative glomerulonephritis.

scholarly journals Modified Huangqi Chifeng Decoction Attenuates Proteinuria by Reducing Podocyte Injury in a Rat Model of Immunoglobulin a Nephropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Meiying Chang ◽  
Bin Yang ◽  
Liusheng Li ◽  
Yuan Si ◽  
Mingming Zhao ◽  
...  
Keyword(s):  
Rat Model ◽  
Mesangial Cells ◽  
Wilms Tumor ◽  
Immunoglobulin A ◽  
Protective Role ◽  
Protective Effects ◽  
Glomerular Mesangial Cells ◽  
Immunoglobulin A Nephropathy ◽  
Podocyte Injury ◽  
Drug Intervention

Modified Huangqi Chifeng decoction (MHCD) has been used to reduce proteinuria in immunoglobulin A nephropathy (IgAN) for many years. Previously, we have demonstrated its protective role in glomerular mesangial cells. Podocyte injury, another key factor associated with proteinuria in IgAN, has also attracted increasing attention. However, whether MHCD can reduce proteinuria by protecting podocytes remains unclear. The present study aimed to investigate the protective effects of MHCD against podocyte injury in a rat model of IgAN. To establish the IgAN model, rats were administered bovine serum albumin, carbon tetrachloride, and lipopolysaccharide. MHCD in three doses or telmisartan was administered once daily for 8 weeks (n = 10 rats/group). Rats with IgAN developed proteinuria at week 6, which worsened over time until drug intervention. After drug intervention, MHCD reduced proteinuria and had no effect on liver and kidney function. Furthermore, MHCD alleviated renal pathological lesions, hyperplasia of mesangial cells, mesangial matrix expansion, and podocyte foot process fusion. Western blot analysis revealed that MHCD increased the expression of the podocyte-associated proteins nephrin and podocalyxin. Additionally, we stained podocyte nuclei with an antibody for Wilms’ tumor protein one and found that MHCD increased the podocyte number in rats with IgAN. In conclusion, these results demonstrate that MHCD attenuates proteinuria by reducing podocyte injury.

scholarly journals Sp1-Induced lncRNA Rmrp Promotes Mesangial Cell Proliferation and Fibrosis in Diabetic Nephropathy by Modulating the miR-1a-3p/JunD Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Hansen Yang ◽  
Jia Wang ◽  
Zheng Zhang ◽  
Rui Peng ◽  
Dan Lv ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Regulatory Mechanisms ◽  
Glomerular Mesangial Cells ◽  
Nuclear Transcription Factor ◽  
Mechanism Research ◽  
Mesangial Cell Proliferation ◽  
Non Coding Rnas ◽  
Subcellular Level

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus. Long non-coding RNAs (lncRNAs) are regulators in DN progression. However, the regulatory mechanisms of multiple lncRNAs in DN remain to be determined. Our aim was to investigate the function and molecular mechanism of lncRNA RNA component of mitochondrial RNAase P (Rmrp) in DN. Here, we observed that the expression of Rmrp was up-regulated in the kidney of db/db DN mice and high glucose induced glomerular mesangial cells (MC). More importantly, the abnormal transcription of Rmrp was induced by nuclear transcription factor Sp1, which promotes the proliferation and production of fibrotic markers in MC. Subsequently, we screened the miRNAs related to Rmrp and found that Rmrp and miR-1a-3p are co-localized at the subcellular level of MC, and Rmrp could directly binds to miR-1a-3p. Further mechanism research demonstrated that the elevated miR-1a-3p significantly attenuated the proliferation and fibrosis-promoting effects induced by up-regulation of Rmrp. At the same time, we also investigated that miR-1a-3p can directly bind to Jun D proto-oncogene (JunD), thereby regulating the protein level of JunD. Rmrp-induced proliferation and fibrogenesis were reversed by co-transfection with JunD siRNA. In summary, Sp1 induced lncRNA Rmrp could drive the expression of JunD via sponging miR-1a-3p in DN progression.

Platelet-activating factor and the kidney

1986 ◽  
Vol 251 (1) ◽  
pp. F1-F11 ◽  
Author(s):  
D. Schlondorff ◽  
R. Neuwirth
Keyword(s):  
De Novo ◽  
Mesangial Cells ◽  
Biological Activities ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Initial Step ◽  
Renal Physiology ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Isolated Kidney

Platelet-activating factor (PAF) represents a group of phospholipids with the basic structure of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine. A number of different cells are capable of producing PAF in response to various stimuli. The initial step of PAF formation is activation of phospholipase A2 in a calcium-dependent manner, yielding lyso-PAF. During this step arachidonic acid is also released and can be converted to its respective cyclooxygenase and lipoxygenase products. The lyso-PAF generated is then acetylated in position 2 of the glycerol backbone by a coenzyme A (CoA)-dependent acetyltransferase. An additional pathway may exist whereby PAF is generated de novo from 1-alkyl-2-acetyl-sn-glycerol by phosphocholine transferase. PAF inactivation in cells and blood is by specific acetylhydrolases. PAF exhibits a variety of biological activities including platelet and leukocyte aggregation and activation, increased vascular permeability, respiratory distress, decreased cardiac output, and hypotension. In the kidney PAF can produce decreases in blood flow, glomerular filtration, and fluid and electrolyte excretion. Intrarenal artery injection of PAF may also result in glomerular accumulation of platelets and leukocytes and mild proteinuria. PAF increases prostaglandin formation in the isolated kidney and in cultured glomerular mesangial cells. PAF also causes contraction of mesangial cells. Upon stimulation with calcium ionophore the isolated kidney, isolated glomeruli and medullary cells, and cultured mesangial cells are capable of producing PAF. The potential role for PAF in renal physiology and pathophysiology requires further investigation that may be complicated by 1) the multiple interactions of PAF, prostaglandins, and leukotrienes and 2) the autocoid nature of PAF, which may restrict its action to its site of generation.

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