309-OR: IGF-1 Receptors, Not Insulin Receptors, on Mesangial Cells Are Accelerating Mesangial Expansion and Albuminuria in Streptozotocin-Induced Diabetic Mice

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 309-OR
Author(s):  
ATSUSHI ISHIKADO ◽  
TAKANORI SHINJO ◽  
HISASHI YOKOMIZO ◽  
YASUTAKA MAEDA ◽  
KYOUNGMIN PARK ◽  
...  
Keyword(s):  
Mesangial Cells ◽  
Insulin Receptors ◽  
Diabetic Mice ◽  
Mesangial Expansion

scholarly journals Carbohydrate response element binding protein (ChREBP) modulates the inflammatory response of mesangial cells in response to glucose

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Yan Chen ◽  
Yan-Jun Wang ◽  
Ying Zhao ◽  
Jin-Cheng Wang
Keyword(s):  
Diabetes Mellitus ◽  
Inflammatory Response ◽  
Mesangial Cells ◽  
Binding Protein ◽  
The Body ◽  
Mrna Levels ◽  
Diabetic Mice ◽  
Response Element ◽  
Tnf Α ◽  
Element Binding Protein

Diabetic nephropathy (DN) is one of the most devastating complications of diabetes mellitus. Carbohydrate response element binding protein (ChREBP) is a basic helix–loop–helix leucine zipper transcription factor that primarily mediates glucose homeostasis in the body. The present study investigated the role of ChREBP in the pathogenesis of DN. The expression of ChREBP was detected in patients with type 2 diabetes mellitus (T2DM), diabetic mice, and mesangial cells. ELISA was used to measure cytokine production in mesangial cells. Flow cytometry analysis was performed to detect the apoptosis of mesangial cells in the presence of high glucose. The expression levels of ChREBP and several cytokines (TNF-α, IL-1β, and IL-6) were up-regulated in T2DM patients. The mRNA and protein levels of ChREBP were also significantly elevated in the kidneys of diabetic mice. Moreover, glucose treatment promoted mRNA levels of TNF-α, IL-1β, and IL-6 in mesangial cells. Glucose stimulation induced significant apoptosis of SV40 MES 13 cells. In addition, transfection with ChREBP siRNA significantly inhibited ChREBP expression. Consequently, the inflammatory responses and apoptosis were inhibited in SV40 MES 13 cells. These results demonstrated that ChREBP could mediate the inflammatory response and apoptosis of mesangial cells, suggesting that ChREBP may be involved in the pathogenesis of DN.

Suppressions of chronic glomerular injuries and TGF-β1 production by HGF in attenuation of murine diabetic nephropathy

2004 ◽  
Vol 286 (1) ◽  
pp. F134-F143 ◽  
Author(s):  
Shinya Mizuno ◽  
Toshikazu Nakamura
Keyword(s):  
Diabetic Nephropathy ◽  
Growth Factor ◽  
Renal Dysfunction ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Renal Diseases ◽  
Glomerular Mesangial Cells ◽  
Diabetic Mice

Diabetic nephropathy is now the leading cause of end-stage renal diseases, and glomerular sclerotic injury is an initial event that provokes renal dysfunction during processes of diabetes-linked kidney disease. Growing evidence shows that transforming growth factor-β1 (TGF-β1) plays a key role in this process, especially in eliciting hypertrophy and matrix overaccumulation. Thus it is important to find a ligand system to antagonize the TGF-β1-mediated pathogenesis under high-glucose conditions. Herein, we provide evidence that hepatocyte growth factor (HGF) targets mesangial cells, suppresses TGF-β1 production, and minimizes glomerular sclerotic changes, using streptozotocin-induced diabetic mice. In our murine model, glomerular sclerogenesis (such as tuft area expansion and collagen deposition) progressed between 6 and 10 wk after the induction of hyperglycemia, during a natural course of diabetic disease. Glomerular HGF expression levels in the diabetic kidney transiently increased but then declined below a basal level, with manifestation of glomerular sclerogenesis. When anti-HGF IgG was injected into mice for 2 wk (i.e., from weeks 4 to 6 after onset of hyperglycemia), these glomerular changes were significantly aggravated. When recombinant HGF was injected into the mice for 4 wk (i.e., between 6 and 10 wk following streptozotocin treatment), the progression of glomerular hypertrophy and sclerosis was almost completely inhibited, even though glucose levels remained unchanged (>500 mg/dl). Even more important, HGF repressed TGF-β1 production in glomerular mesangial cells even under hyperglycemic conditions both in vitro and in vivo. Consequently, not only albuminuria but also tubulointerstitial fibrogenesis were attenuated by HGF. Overall, HGF therapy inhibited the onset of renal dysfunction in the diabetic mice. On the basis of these findings, we wish to emphasize that HGF plays physiological and therapeutic roles in blocking renal fibrogenesis during a course of diabetic nephropathy.

scholarly journals Proteasome Activators, PA28α and PA28β, Govern Development of Microvascular Injury in Diabetic Nephropathy and Retinopathy

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Saeed Yadranji Aghdam ◽  
Ali Mahmoudpour
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Molecular Mechanisms ◽  
Mesangial Cells ◽  
Diabetic Mice ◽  
Double Knockout ◽  
Monocyte Chemoattractant Protein 1 ◽  
Microvascular Injury ◽  
Retinal Pericytes ◽  
Diabetes Model

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are major complications of type 1 and type 2 diabetes. DN and DR are mainly caused by injury to the perivascular supporting cells, the mesangial cells within the glomerulus, and the pericytes in the retina. The genes and molecular mechanisms predisposing retinal and glomerular pericytes to diabetic injury are poorly characterized. In this study, the genetic deletion of proteasome activator genes, PA28α and PA28β genes, protected the diabetic mice in the experimental STZ-induced diabetes model against renal injury and retinal microvascular injury and prolonged their survival compared with wild type STZ diabetic mice. The improved wellbeing and reduced renal damage was associated with diminished expression of Osteopontin (OPN) and Monocyte Chemoattractant Protein-1 (MCP-1) in the glomeruli of STZ-injected PA28α/PA28β double knockout (Pa28αβDKO) mice and also in cultured mesangial cells and retinal pericytes isolated from Pa28αβDKO mice that were grown in high glucose. The mesangial PA28-mediated expression of OPN under high glucose conditions was suppressed by peptides capable of inhibiting the binding of PA28 to the 20S proteasome. Collectively, our findings demonstrate that diabetic hyperglycemia promotes PA28-mediated alteration of proteasome activity in vulnerable perivascular cells resulting in microvascular injury and development of DN and DR.

scholarly journals CD4/CD8 Antibodies Reduce Histopathological Damage in Salivary Glands of Spontaneously Diabetic Mice

2019 ◽  
Vol 26 (2) ◽  
pp. 149-157
Author(s):  
Raphael Oliveira Ramos Franco Netto ◽  
Eliézer Guimarães Moura ◽  
Luan Oenning Col ◽  
Magda Jaciara Barros ◽  
Juliana de Almeida Rodrigues Franco Netto ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Nod Mice ◽  
Insulin Receptors ◽  
Nonparametric Test ◽  
Diabetic Mice ◽  
Parotid Glands ◽  
Submandibular Glands ◽  
Group Iii ◽  
Group I ◽  
Group Ii

Abstract Background and aims: Diabetes affects the metabolism promoting damage in different tissues, including salivary glands. Current treatments, such as insulin, are ineffective to recovery of these tissues. In this aspect, the immunotherapy has been tested, but it can be inefficient as an agent for the control of damage caused by diabetes. The aim of this study to evaluate the association in anti-CD4 and anti-CD8 monoclonal antibody in the recovery of salivary glands of diabetic NOD mice. Material and methods: Fifteen spontaneously diabetic mice (NOD) were divided into three groups with 5 animals each: group I (Balb/C control mice), group II (untreated NOD mice), group III (NOD mice treated with CD4 and CD8 antibodies). The CD4 and CD8 antibodies (IMUNY, Rheabiotech Ltda, Brazil) were administered by intravenously injections (25 ug/days: 0, 7, 14, and 21). After treatment salivary glands samples were analyzed by immunofluorescence, microscopy, light microscopy and stereology. (ethical approval process: 304/11), Analysis of variance (ANOVA) and Kruskal-Wallis nonparametric test were used. Results: Elevated levels of glucose (mg/dl) were observed in untreated animals (group II) (605.25 ± 31.23, p≤0.05), whereas in treated animals (group III), were noted a decrease in these levels (464.77 ± 39.66, p≤0.05). Tissue restructure, characterized by cell volume recovery, also was observed in group III (nuclear volume of parotid glands: (109.91 ± 02.03, p≤0.05) and submandibular glands: (107.52 ± 02, p≤0.05) (cytoplasmic volume of parotid glands: (356.14 ± 26.34, p≤0.05) and submandibular glands: (331.22 ± 32.11, p≤0.05). Intense signaling (+++) of insulin receptors was observed in animals of group I. On the other hand, in group II was noted a reduction of these receptors (+). In treated animals (group III) were observed a recovery of the insulin receptors (+++). Conclusions: This treatment was effective in the recovery of salivary acinar cells, contributed also to homeostasis of body metabolism. Thus, this immunomodulation promoted a beneficial effect on the recovery of these tissues.

Use of antioxidant in the attempt recovery of insulin receptors in salivary glands of spontaneously diabetic mice

2012 ◽  
Vol 23 (2) ◽  
pp. 35-39
Author(s):  
Raphael Oliveira Ramos Franco Netto ◽  
Rafael Mancio ◽  
Rodrigo Eduardo Silva ◽  
Eliézer Guimarães Moura ◽  
Marco Antonio Dias ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Insulin Receptors ◽  
Diabetic Mice

scholarly journals Exendin-4 Improves Diabetic Kidney Disease in C57BL/6 Mice Independent of Brown Adipose Tissue Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shu Fang ◽  
Yingying Cai ◽  
Fuping Lyu ◽  
Hongbin Zhang ◽  
Chunyan Wu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Blood Glucose ◽  
Renal Fibrosis ◽  
Mesangial Cells ◽  
Treated Group ◽  
Diabetic Mice ◽  
Urine Albumin ◽  
Brown Adipose

Background. The role of exendin-4 in brown adipose tissue (BAT) activation was not very clear. This study is to verify the role of BAT involved in renal benefits of exendin-4 in diabetes mellitus (DM). Methods. In vivo, C57BL/6 mice were randomly divided into nondiabetic (control) and diabetic groups (DM). The diabetic mice were randomized into a control group (DM-Con), BAT-excision group (DM+Exc), exendin-4-treated group (DM+E4), and BAT-excision plus exendin-4-treated group (DM+Exc+E4). The weight, blood glucose and lipids, 24 h urine albumin and 8-OH-dG, and renal fibrosis were analyzed. In vitro, we investigated the role of exendin-4 in the differentiation process of 3T3-L1 and brown preadipocytes and its effect on the rat mesangial cells induced by oleate. Results. The expressions of UCP-1, PGC-1α, ATGL, and CD36 in BAT of DM mice were all downregulated, which could be upregulated by exendin-4 treatment with significant effects on ATGL and CD36. BAT-excision exacerbated high blood glucose (BG) with no significant effect on the serum lipid level. Exendin-4 significantly lowered the level of serum triglycerides (TG) and low-density lipoprotein- (LDL-) c, 24 h urine albumin, and 8-OH-dG; improved renal fibrosis and lipid accumulation; and activated renal AMP-activated protein kinase (AMPK) in diabetic mice regardless of BAT excision. In vitro, there was no significant effect of exendin-4 on brown or white adipogenesis. However, exendin-4 could improve lipid accumulation and myofibroblast-like phenotype transition of mesangial cells induced by oleate via activating the AMPK pathway. Conclusions. Exendin-4 could decrease the renal lipid deposit and improve diabetic nephropathy via activating the renal AMPK pathway independent of BAT activation.

scholarly journals Involvement of p300/CBP and epigenetic histone acetylation in TGF-β1-mediated gene transcription in mesangial cells

2013 ◽  
Vol 304 (5) ◽  
pp. F601-F613 ◽  
Author(s):  
Hang Yuan ◽  
Marpadga A. Reddy ◽  
Guangdong Sun ◽  
Linda Lanting ◽  
Mei Wang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Histone Acetylation ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Mrna Levels ◽  
Creb Binding Protein ◽  
Diabetic Mice ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tgf Β1 ◽  
Pai 1

Transforming growth factor-β1 (TGF-β1)-induced expression of plasminogen activator inhibitor-1 (PAI-1) and p21 in renal mesangial cells (MCs) plays a major role in glomerulosclerosis and hypertrophy, key events in the pathogenesis of diabetic nephropathy. However, the involvement of histone acetyl transferases (HATs) and histone deacetylases (HDACs) that regulate epigenetic histone lysine acetylation, and their interaction with TGF-β1-responsive transcription factors, are not clear. We evaluated the roles of histone acetylation, specific HATs, and HDACs in TGF-β1-induced gene expression in rat mesangial cells (RMCs) and in glomeruli from diabetic mice. Overexpression of HATs CREB binding protein (CBP) or p300, but not p300/CBP-activating factor, significantly enhanced TGF-β1-induced PAI-1 and p21 mRNA levels as well as transactivation of their promoters in RMCs. Conversely, they were significantly attenuated by HAT domain mutants of CBP and p300 or overexpression of HDAC-1 and HDAC-5. Chromatin immunoprecipitation assays showed that TGF-β1 treatment led to a time-dependent enrichment of histone H3-lysine9/14-acetylation (H3K9/14Ac) and p300/CBP occupancies around Smad and Sp1 binding sites at the PAI-1 and p21 promoters. TGF-β1 also enhanced the interaction of p300 with Smad2/3 and Sp1 and increased Smad2/3 acetylation. High glucose-treated RMCs exhibited increased PAI-1 and p21 levels, and promoter H3K9/14Ac, which were blocked by TGF-β1 antibodies. Furthermore, increased PAI-1 and p21 expression was associated with elevated promoter H3K9/14Ac levels in glomeruli from diabetic mice. Thus TGF-β1-induced PAI-1 and p21 expression involves interaction of p300/CBP with Smads and Sp1, and increased promoter access via p300/CBP-induced H3K9/14Ac. This in turn can augment glomerular dysfunction linked to diabetic nephropathy.

scholarly journals SP600125 suppresses Keap1 expression and results in NRF2-mediated prevention of diabetic nephropathy

2018 ◽  
Vol 60 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Huan Zhang ◽  
Xiuxia Liu ◽  
Shanshan Zhou ◽  
Ye Jia ◽  
Ying Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Nephropathy ◽  
Nuclear Translocation ◽  
Mesangial Cells ◽  
Critical Role ◽  
Antioxidant Defense System ◽  
Related Factor ◽  
Diabetic Mice ◽  
Nrf2 Protein

c-Jun N-terminal kinase (JNK) contributes to the pathogenesis of diabetic nephropathy (DN). The JNK inhibitor SP600125 was reported to ameliorate DN. However, the mechanism remained unclear. We previously reported that SP600125 activated nuclear factor erythroid 2-related factor 2 (NRF2), a governor of the cellular antioxidant defense system, in the aortas of the diabetic mice. Given the critical role of NRF2 in preventing DN, the present study aimed to test whether or not NRF2 is required for SP600125’s protection against DN. To test the role of NRF2 in SP600125’s effect, streptozotocin-induced C57BL/6 wild-type (WT) and Nrf2-knockout (KO) diabetic mice were treated in the presence or absence of SP600125, for 24 weeks. To explore the mechanism by which SP600125 activates NRF2, mouse mesangial cells (MMCs) were treated with high glucose (HG), in the presence or absence of either SP600125 or JNK siRNA. SP600125 significantly attenuated the diabetes-induced renal oxidative stress, inflammation, fibrosis, pathological change and dysfunction in the WT, but not the Nrf2 KO mice. SP600125 inactivated JNK, inhibited kelch-like ECH-associated protein 1 expression, preserved NRF2 protein and facilitated its nuclear translocation in the kidneys of the WT mice, the effects of which were similarly produced by either SP600125 or JNK siRNA in HG-treated MMCs. Further, both SP600125 and JNK siRNA alleviated HG-induced mesangial oxidative stress and expression of inflammatory and fibrotic genes. The present study demonstrates that NRF2 is required for SP600125’s protection against DN. SP600125 activates NRF2 possibly via inhibition of JNK-induced Keap1 expression.

Regulation of pancreatic acinar cell insulin receptors by insulin

1984 ◽  
Vol 247 (2) ◽  
pp. G155-G160 ◽  
Author(s):  
J. Mossner ◽  
C. D. Logsdon ◽  
I. D. Goldfine ◽  
J. A. Williams
Keyword(s):  
Acinar Cell ◽  
Insulin Receptors ◽  
Insulin Binding ◽  
Pancreatic Acinar Cell ◽  
Diabetic Mice ◽  
Pancreatic Acini ◽  
Endogenous Insulin ◽  
High Concentrations ◽  
Triton X

In vivo pancreatic acini from normal mice are exposed to very high concentrations of insulin. To determine whether insulin receptors in these acini are downregulated by this endogenous insulin, insulin receptors on acini from both normal and diabetic mice were studied. Isolated acini from normal mice, which have accompanying islets of Langerhans, were studied under conditions where endogenous insulin was minimized. These acini bound 50% less 125I-insulin than acini from mice made diabetic with streptozotocin. Computer analysis of competition-inhibition curves showed a decrease in the number of insulin receptors in acini from normal mice when compared with acini from diabetic mice; however, the IC50 (a measure of receptor affinity) remained unchanged at approximately 1 nM. To study further the regulation of acinar cell insulin receptors, acini from diabetic mice were placed in suspension culture for 24 h. Addition of 1 microM insulin during the culture period led to a 30% decrease in subsequent 125I-insulin binding; the presence or absence of either epidermal growth factor or carbachol was without effect on insulin binding. The decrease in binding induced by insulin resulted from a change in receptor number without an alteration of the IC50. Measurement of total acinar cell insulin receptors by solubilization of these acini in 1% Triton X-100 showed that this insulin-induced decrease was due to a change in the total number of cellular insulin receptors. The present study suggests, therefore, that insulin can regulate its own receptor on pancreatic acini and that in vivo insulin receptors in normal pancreatic cells are downregulated, presumably due to high ambient insulin concentrations.

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