scholarly journals TGFβ acts through PDGFRβ to activate mTORC1 via the Akt/PRAS40 axis and causes glomerular mesangial cell hypertrophy and matrix protein expression

2020 ◽  
Vol 295 (42) ◽  
pp. 14262-14278
Author(s):  
Soumya Maity ◽  
Falguni Das ◽  
Balakuntalam S. Kasinath ◽  
Nandini Ghosh-Choudhury ◽  
Goutam Ghosh Choudhury
Keyword(s):  
Growth Factor ◽  
Matrix Protein ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Kidney Cortex ◽  
Glomerular Mesangial Cells ◽  
Cell Hypertrophy ◽  
Tgfβ Receptor ◽  
Mtorc1 Activation ◽  
Noncanonical Signaling

Interaction of transforming growth factor-β (TGFβ)-induced canonical signaling with the noncanonical kinase cascades regulates glomerular hypertrophy and matrix protein deposition, which are early features of glomerulosclerosis. However, the specific target downstream of the TGFβ receptor involved in the noncanonical signaling is unknown. Here, we show that TGFβ increased the catalytic loop phosphorylation of platelet-derived growth factor receptor β (PDGFRβ), a receptor tyrosine kinase expressed abundantly in glomerular mesangial cells. TGFβ increased phosphorylation of the PI 3-kinase–interacting Tyr-751 residue of PDGFRβ, thus activating Akt. Inhibition of PDGFRβ using a pharmacological inhibitor and siRNAs blocked TGFβ-stimulated phosphorylation of proline-rich Akt substrate of 40 kDa (PRAS40), an intrinsic inhibitory component of mTORC1, and prevented activation of mTORC1 in the absence of any effect on Smad 2/3 phosphorylation. Expression of constitutively active myristoylated Akt reversed the siPDGFRβ-mediated inhibition of mTORC1 activity; however, co-expression of the phospho-deficient mutant of PRAS40 inhibited the effect of myristoylated Akt, suggesting a definitive role of PRAS40 phosphorylation in mTORC1 activation downstream of PDGFRβ in mesangial cells. Additionally, we demonstrate that PDGFRβ-initiated phosphorylation of PRAS40 is required for TGFβ-induced mesangial cell hypertrophy and fibronectin and collagen I (α2) production. Increased activating phosphorylation of PDGFRβ is also associated with enhanced TGFβ expression and mTORC1 activation in the kidney cortex and glomeruli of diabetic mice and rats, respectively. Thus, pursuing TGFβ noncanonical signaling, we identified how TGFβ receptor I achieves mTORC1 activation through PDGFRβ-mediated Akt/PRAS40 phosphorylation to spur mesangial cell hypertrophy and matrix protein accumulation. These findings provide support for targeting PDGFRβ in TGFβ-driven renal fibrosis.

scholarly journals Regulation of Rat Mesangial Cell Migration by Platelet-Derived Growth Factor, Angiotensin II, and Adrenomedullin

1999 ◽  
Vol 10 (12) ◽  
pp. 2495-2502 ◽  
Author(s):  
MASAKAZU KOHNO ◽  
KENICHI YASUNARI ◽  
MIEKO MINAMI ◽  
HIROAKI KANO ◽  
KENSAKU MAEDA ◽  
...  
Keyword(s):  
Cell Migration ◽  
Angiotensin Ii ◽  
Growth Factor ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Inhibitory Effect ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Concentration Dependent Manner

Abstract. This study sought to determine whether platelet-derived growth factor (PDGF) and angiotensin II (AngII) stimulate migration of cultured rat glomerular mesangial cells. After finding that this was so, the effects of adrenomedullin (ADM) and cAMP-elevating agents on basal and stimulated mesangial cell migration were examined. Two isoforms of PDGF, AB and BB, stimulated migration in a concentration-dependent manner between 1 and 50 ng/ml, while the AA isoform lacked significant effect. AngII modestly but significantly stimulated migration in a concentration-dependent manner between 10-7 and 10-6 mol/L. Rat ADM significantly inhibited the PDGF BB- and AngII-stimulated migration in a concentration-dependent manner between 10-8 and 10-7 mol/L. Inhibition by rat ADM was accompanied by an increase in cellular cAMP. cAMP agonists or inducers such as 8-bromo cAMP, forskolin, and prostaglandin I2 also significantly reduced the stimulated migration. H 89, a protein kinase A (PKA) inhibitor, attenuated the inhibitory effect of ADM, and a calcitonin gene-related peptide (CGRP) receptor antagonist, human CGRP (8-37), abolished the inhibitory effects of rat ADM. These results suggest that PDGF AB and BB as well as AngII stimulate rat mesangial cell migration and that ADM can inhibit PDGF BB- and AngII-stimulated migration, at least in part through cAMP-dependent mechanisms likely to involve specific ADM receptors with which CGRP interacts. The adenylate cyclase/cAMP/PKA system may be involved in the migration-inhibitory effect of ADM in these cells.

scholarly journals Macrophages promote prosclerotic responses in cultured rat mesangial cells: a mechanism for the initiation of glomerulosclerosis.

1997 ◽  
Vol 8 (10) ◽  
pp. 1525-1536
Author(s):  
I Z Pawluczyk ◽  
K P Harris
Keyword(s):  
Growth Factor ◽  
Matrix Protein ◽  
Transforming Growth Factor ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Platelet Derived Growth Factor ◽  
Minor Role ◽  
Dependent Manner ◽  
The Matrix

Glomerulosclerosis is the final outcome of a number of different causes of glomerular injury, during which the structures of the glomerulus are obliterated by extracellular matrix. Accumulating evidence suggests that infiltrating macrophages play a pivotal role in the progression to glomerulosclerosis. The present study defines the role played by macrophages at both cellular and molecular levels in the initiation of the sclerotic process in cultured rat mesangial cells. Macrophage-conditioned medium (MPCM) generated from thioglycollate-elicited, lipopolysaccharide-stimulated macrophages upregulated mesangial cell fibronectin production in a dose- and time-dependent manner, independently of cell proliferation. Immunoprecipitation of metabolically labeled 35S-fibronectin confirmed that the matrix protein was synthesized de novo. The genes for fibronectin and the matrix proteins laminin and collagen IV were also found to be upregulated 2.86 +/- 0.24-, 4.94 +/- 0.17-, and 3.03 +/- 0.31-fold over controls, respectively (P < 0.001). Macrophage modulation of matrix turnover was suggested by an upregulation of both transin and tissue inhibitor of metalloproteinase-1 gene transcription. Transforming growth factor (TGF) beta1, platelet-derived growth factor, tumor necrosis factor (TNF) alpha, or interleukin (IL)-1beta could not be detected in the MPCM per se; however, TGFbeta1 and platelet-derived growth factor AB were found to be secreted into mesangial cell culture supernatants. Secretion was augmented 1.69 +/- 0.16- and 2.28 +/- 0.28-fold, respectively (both P < 0.001), in response to MPCM. Northern blot analysis demonstrated that protein secretion had been preceded by upregulation of the genes for these cytokines (2.2 +/- 0.4-fold [P < 0.001] and 5.7 +/- 1.2-fold [P < 0.004], respectively). Incubation of MPCM with either neutralizing antibody or the growth factor receptor antagonist suramin demonstrated that TGFbeta1 played a significant, although minor, role in MPCM-stimulated fibronectin production. In conclusion, this study provides compelling evidence for a direct role of macrophages in the progression to glomerulosclerosis.

Synthesis and release of insulinlike growth factor I by mesangial cells in culture

1988 ◽  
Vol 255 (6) ◽  
pp. F1214-F1219 ◽  
Author(s):  
F. G. Conti ◽  
L. J. Striker ◽  
S. J. Elliot ◽  
D. Andreani ◽  
G. E. Striker
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Culture Medium ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Glomerular Mesangial Cells ◽  
Factor I ◽  
Cells In Culture ◽  
Igf I ◽  
Insulinlike Growth Factor I

Mesangial cell proliferation is a common hallmark of many glomerular diseases. The exact mechanisms inducing cell proliferation in glomerulosclerosis are not completely understood, and it remains to be determined whether growth factors play a role in this process. Insulinlike growth factor I (IGF I) has been shown to be synthesized in the kidney, and glomerular mesangial cells have receptors for and exhibit mitogenic response to IGF I. We found that mouse glomerular mesangial cells in culture synthesized and released into the culture medium a molecule with immunological and biological features of IGF I. This molecule specifically bound to mesangial cell IGF I receptors; high-pressure liquid chromatographic analysis provided further evidence of its similarity to human recombinant IGF I. Mesangial cells released into the culture medium 6 ng/10(6) cells of IGF I-like material per 24 h in a time-dependent and actinomycin-D inhibitable fashion. These data suggest that IGF I might be locally released by mesangial cells in the glomerulus and act in an autocrine and paracrine fashion.

scholarly journals Insulin-like Growth Factor I (IGF-I) Induces Unique Effects in the Cytoskeleton of Cultured Rat Glomerular Mesangial Cells

1997 ◽  
Vol 45 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Anne K. Berfield ◽  
Douglas Spicer ◽  
Christine K. Abrass
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Smooth Muscle Actin ◽  
Ultrastructural Changes ◽  
Insulin Like Growth Factor ◽  
Glomerular Mesangial Cells ◽  
Muscle Actin ◽  
Igf I

Resident glomerular mesangial cells (MCs) have complex cytoskeletal organizations that maintain functional and structural integrity. The ability of cells to replicate, coordinate movement, change shape, and interact with contiguous cells or extracellular matrix depends on cytoskeletal organization. MCs synthesize insulin-like growth factor (IGF-I), express IGF-I receptors, and respond to IGF-I with increased proliferation. We noted that IGF-I treatment of mesangial cells was associated with a change in morphology. Therefore, these studies were undertaken to define specific IGF-I-mediated changes in cytoskeletal protein organization. Rat MCs were propagated from birth in culture without supplemental insulin. Quiescent, subconfluent cultures were treated with IGF-I (100 nM) for 1 hr. Rearrangements in f-actin, α-smooth muscle actin, β-actin, vimentin, and vinculin were seen by fluorescence microscopy. As the cytoskeleton rearranged, α-smooth muscle actin dissociated from the f-actin bundles and β-actin became polymerized under the leading lamellar edge. Ultrastructural changes were consistent with increased membrane turnover and metabolic activity. The normally sessile mesangial cell was induced by IGF-I to express a wound-healing phenotype characterized by movement and increased pinocytosis. These changes are different from those induced by insulin and have important implications for mesangial cell function.

scholarly journals Tumor necrosis factor alpha activates soluble guanylate cyclase in bovine glomerular mesangial cells via an L-arginine-dependent mechanism.

1990 ◽  
Vol 172 (6) ◽  
pp. 1843-1852 ◽  
Author(s):  
P A Marsden ◽  
B J Ballermann
Keyword(s):  
Guanylate Cyclase ◽  
Mesangial Cell ◽  
Soluble Guanylate Cyclase ◽  
Mesangial Cells ◽  
Tnf Alpha ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Concentration Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Factor Alpha

Endothelium-derived nitric oxide (NO) causes vasodilatation by activating soluble guanylate cyclase, and glomerular mesangial cells respond to NO with elevations of intracellular guanosine 3',5'-cyclic monophosphate (cGMP). We explored whether mesangial cells can be stimulated to produce NO and whether NO modulates mesangial cell function in an autocrine or paracrine fashion. Tumor necrosis factor alpha (TNF-alpha) raised mesangial cell cGMP levels in a time- and concentration-dependent manner (threshold dose 1 ng/ml, IC50 13.8 ng/ml, maximal response 100 ng/ml). TNF-alpha-induced increases in mesangial cGMP content were evident at 8 h and maximal at 18-24 h. The TNF-alpha-induced stimulation of mesangial cell cGMP production was abrogated by actinomycin D or cycloheximide suggesting dependence on new RNA or protein synthesis. Hemoglobin and methylene blue, both known to inhibit NO action, dramatically reduced TNF-alpha-induced mesangial cell cGMP production. Superoxide dismutase, known to potentiate NO action, augmented the TNF-alpha-induced effect. Ng-monomethyl-L-arginine (L-NMMA) decreased cGMP levels in TNF-alpha-treated, but not vehicle-treated mesangial cells in a concentration-dependent manner (IC50 53 microM). L-arginine had no effect on cGMP levels in control or TNF-alpha-treated mesangial cells but reversed L-NMMA-induced inhibition. Interleukin 1 beta and lipopolysaccharide (LPS), but not interferon gamma, also increased mesangial cell cGMP content. Transforming growth factor beta 1 blunted the mesangial cell response to TNF-alpha. TNF-alpha-induced L-arginine-dependent increases in cGMP were also evident in bovine renal artery vascular smooth muscle cells, COS-1 cells, and 1502 human fibroblasts. These findings suggest that TNF-alpha induces expression in mesangial cell of an enzyme(s) involved in the formation of L-arginine-derived NO. Moreover, the data indicate that NO acts in an autocrine and paracrine fashion to activate mesangial cell soluble guanylate cyclase. Cytokine-induced formation of NO in mesangial and vascular smooth muscle cells may be implicated in the pathogenesis of septic shock.

Studies on Binding and Mitogenic Effect of Insulin and Insulin-Like Growth Factor I in Glomerular Mesangial Cells*

Endocrinology ◽  
1988 ◽  
Vol 122 (6) ◽  
pp. 2788-2795 ◽  
Author(s):  
FRANCESCO G. CONTI ◽  
LILIANE J. STRIKER ◽  
MAXINE A. LESNIAK ◽  
KAREN MACKAY ◽  
JESSE ROTH ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mesangial Cells ◽  
Insulin Like Growth Factor ◽  
Glomerular Mesangial Cells ◽  
Mitogenic Effect ◽  
Factor I ◽  
Growth Factor I

scholarly journals LncRNA NEAT1 Promotes High Glucose-Induced Mesangial Cell Hypertrophy by Targeting miR-222-3p/CDKN1B Axis

2021 ◽  
Vol 7 ◽  
Author(s):  
Lin Liao ◽  
Jie Chen ◽  
Chuanfu Zhang ◽  
Yue Guo ◽  
Weiwei Liu ◽  
...  
Keyword(s):  
High Glucose ◽  
Noncoding Rna ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Morphological Alteration ◽  
Glomerular Hypertrophy ◽  
Cell Hypertrophy ◽  
Rna Immunoprecipitation ◽  
Lncrna Neat1

Glomerular hypertrophy is an early morphological alteration in diabetic nephropathy. Cyclin-Dependent Kinases have been shown to be required for high glucose (HG)-induced hypertrophy; however, the upstream regulators of CDKN1B in glomerular hypertrophy remain unclear. Herein we describe a novel pathway in which Long noncoding RNA (lncRNA) NEAT1 regulates the progression of mesangial cell hypertrophy via a competing endogenous RNA (ceRNA) mechanism. Real-time PCR was performed to detect the relative NEAT1 and miR-222-3p expressions and further confirmed the relationship between NEAT1 and miR-222-3p. Cell cycle was evaluated by flow cytometry. The related mechanisms were explored by Western blot, RNA immunoprecipitation and chromatin immunoprecipitation assay. We show that NEAT1 forms double stranded RNA (dsRNA) with miR-222-3p, thus limiting miR-222-3p’s binding with CDKN1B. This release of CDKN1B mRNA leads to elevated CDKN1B protein expression, resulting in hypertrophy. In addition, we demonstrated that STAT3 which is activated by HG induces the transcription of NEAT1 by binding to its promoter. Our findings underscore an unexpected role of lncRNAs on gene regulation and introduce a new mode of proliferation regulation in mesangial cells.

Mesangial cells express PDGF mRNAs and proliferate in response to PDGF

1988 ◽  
Vol 255 (4) ◽  
pp. F674-F684 ◽  
Author(s):  
P. J. Shultz ◽  
P. E. DiCorleto ◽  
B. J. Silver ◽  
H. E. Abboud
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Northern Blot Analysis ◽  
Mesangial Cells ◽  
Glomerular Mesangial Cells ◽  
Human Mesangial Cells ◽  
Human Foreskin Fibroblasts ◽  
Human Glomerular Mesangial Cells ◽  
Paracrine Growth Factor

Platelet-derived growth factor (PDGF) is a potent mitogen for cells of mesenchymal origin and is released and/or synthesized by platelets, macrophages, endothelial cells, and rat mesangial cells. In the present investigation, we found that human glomerular mesangial cells in culture release a PDGF-like protein which competes for 125I-PDGF binding to human foreskin fibroblasts and is mitogenic for these fibroblasts. The competing and to a lesser extent the mitogenic activities present in the conditioned medium are partially recognized by an anti-PDGF antibody. Northern blot analysis of poly(A)+ RNA from human mesangial cells demonstrates the expression of both PDGF A- and B-chain mRNAs. PDGF also binds to mesangial cells in a specific manner and stimulates DNA synthesis and cell proliferation. These data suggest that a PDGF-like protein secreted by mesangial cells or released from platelets, monocytes, or endothelial cells during glomerular inflammation may function as an autocrine or a paracrine growth factor for these cells. The biological role of PDGF in mediating proliferative and other inflammatory events in the glomerulus remains to be identified.

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