Molecular analysis of spontaneous glomerulosclerosis in Os/+ mice, a model with reduced nephron mass

1995 ◽  
Vol 269 (2) ◽  
pp. F266-F273 ◽  
Author(s):  
C. He ◽  
R. K. Zalups ◽  
D. A. Henderson ◽  
G. E. Striker ◽  
L. J. Striker

Oligosyndactyly mice (ROP Os/+) are a radiation-induced mutant strain with reduced glomerular number and increased glomerular size. We found that they develop glomerulosclerosis. At 3 mo, ROP Os/+ mice had diffuse mesangial expansion by light microscopy, whereas their +/+ littermates did not. Electron microscopic morphometry revealed a twofold increase in mesangial areas but no changes in the thickness of glomerular basal laminae. Mean glomerular volume was increased 1.8-fold. Cell number and thymidine labeling index were increased 1.3- and 2.4-fold, respectively. The amount of glomerular type IV collagen and tenascin but not laminin was increased by immunofluorescence microscopy. mRNA levels in microdissected glomeruli were measured by competetive reverse transcription-polymerase chain reaction and corrected for cell number. alpha 1-Chain type IV collagen and tenascin mRNAs were increased 3.2-fold and 1.8-fold, whereas laminin B1 mRNA levels were not. The levels of 72-kDa collagenase mRNA were increased 1.6-fold. Transforming growth factor-beta 1 mRNA levels were elevated 1.8-fold, but platelet-derived growth factor-B mRNA levels remained normal. This is the first analysis of glomerular molecular and cellular changes in a model of congenital nephron reduction.

2001 ◽  
Vol 280 (4) ◽  
pp. F667-F674 ◽  
Author(s):  
Chhinder P. Sodhi ◽  
Sarojini A. Phadke ◽  
Daniel Batlle ◽  
Atul Sahai

The effect of hypoxia on the proliferation and collagen synthesis of cultured rat mesangial cells was examined under normal-glucose (NG, 5 mM) and high-glucose (HG, 25 mM)-media conditions. In addition, a role for osteopontin (OPN) in mediating these processes was assessed. Quiescent cultures were exposed to hypoxia (3% O2) and normoxia (18% O2) in a serum-free medium with NG or HG, and cell proliferation, collagen synthesis, and OPN expression were assessed. Cells exposed to hypoxia in NG medium resulted in significant increases in [3H]thymidine incorporation, cell number, and [3H]proline incorporation, respectively. HG incubations also produced significant stimulation of these parameters under normoxic conditions, which were markedly enhanced in cells exposed to hypoxia in HG medium. In addition, hypoxia and HG stimulated the mRNA levels of type IV collagen, and the combination of hypoxia and HG resulted in additive increases in type IV collagen expression. Hypoxia and HG also stimulated OPN mRNA and protein levels in an additive fashion. A neutralizing antibody to OPN or its β3-integrin receptor significantly blocked the effect of hypoxia and HG on proliferation and collagen synthesis. In conclusion, these results demonstrate for the first time that hypoxia in HG medium produces exaggerated mesangial cell growth and type IV collagen synthesis. In addition, OPN appears to play a role in mediating the accelerated mesangial cell growth and collagen synthesis found in a hyperglycemic and hypoxic environment.


1991 ◽  
Vol 2 (6) ◽  
pp. 467-477 ◽  
Author(s):  
U I Heine ◽  
J K Burmester ◽  
K C Flanders ◽  
D Danielpour ◽  
E F Munoz ◽  
...  

Using both electron microscopic immunohistochemistry and cell fractionation techniques, we show that transforming growth factor-beta 1 (TGF-beta 1) is found in mitochondria of rat and mouse cardiac myocytes and rat hepatocytes. Four different polyclonal antibodies, raised against various epitopes encompassing the mature portion of the TGF-beta 1 molecule as well as the pro-region of its precursor, were used for the electron microscopy studies. The localization of TGF-beta 1 in mitochondria was confirmed by detection of the native peptide in mitochondria isolated from rat heart and liver; the majority of native TGF-beta 1 found in liver homogenates was recovered in highly pure mitochondrial fractions. The functional role of TGF-beta in the mitochondrion is unknown at present.


1998 ◽  
Vol 274 (2) ◽  
pp. F252-F258 ◽  
Author(s):  
Jun Lei ◽  
Sharon Silbiger ◽  
Fuad N. Ziyadeh ◽  
Joel Neugarten

We examined the hypothesis that fetal calf serum (FCS) stimulates murine mesangial cell α1 type IV collagen ( COL4A1) gene transcription by increasing autocrine production of transforming growth factor-β (TGF-β) through a platelet-derived growth factor (PDGF)-dependent mechanism. PDGF-stimulated COL4A1 gene transcription was inhibited by neutralizing antibody to TGF-β (119.3 ± 3.6 vs. 106.0 ± 6.2 relative luciferase units, expressed as a percentage of control untreated cells, P < 0.003). FCS-stimulated gene transcription was inhibited by neutralizing antibody to PDGF (148.3 ± 4.1 vs. 136.7 ± 0.3 relative luciferase units, P < 0.002) and by neutralizing antibody to TGF-β (148.3 ± 4.1 vs. 127.1 ± 3.4 relative luciferase units, P < 0.036). The inhibitory effect of combined treatment with anti-PDGF and anti-TGF-β antibody on gene transcription was no greater than that of anti-TGF-β antibody alone [129.5 ± 0.53 vs. 127.1 ± 3.4 relative luciferase units, P = not significant (NS)]. FCS-stimulated gene transcription was also inhibited by estradiol (10−7 M) (148.4 ± 3.1 vs. 119.4 ± 8.1 relative luciferase units, P < 0.019). In the presence of estradiol, anti-TGF-β antibody failed to further reduce serum-stimulated gene transcription (119.4 ± 8.1 vs. 115.6 ± 9.8, P = NS), suggesting that estradiol reverses FCS-stimulated COL4A1 gene transcription by antagonizing the actions of TGF-β. Measurement of type IV collagen synthesis by Western blotting confirmed that the intact gene responded in a manner analogous to the promoter construct.


2019 ◽  
Vol 47 (7) ◽  
pp. 871-880
Author(s):  
Ezequiel Campos‐Mollo ◽  
Yago Varela‐Conde ◽  
Pedro Arriola‐Villalobos ◽  
Rubén Cabrera‐Beyrouti ◽  
José‐Manuel Benítez‐del‐Castillo ◽  
...  

2005 ◽  
Vol 186 (1) ◽  
pp. 109-121 ◽  
Author(s):  
M-O Faure ◽  
L Nicol ◽  
S Fabre ◽  
J Fontaine ◽  
N Mohoric ◽  
...  

Activins and inhibins, members of the transforming growth factor-beta family are able to stimulate and inhibit, respectively, FSH synthesis and release. Other members of this superfamily, the bone morphogenetic proteins (BMPs), may also affect FSH synthesis in the mouse. The aim of this work was to determine whether BMPs are expressed in the ovine pituitary and whether they play a role in the regulation of FSH release. The mRNAs encoding BMP-2, BMP-4, BMP-7 and the oocyte-derived growth factor, growth differentiation factor (GDF)-9 were detected in the pituitaries of cyclic ewes by reverse-transcriptase PCR, as well as the mRNAs encoding the BMP type I receptors, BMPR-IA (activin-receptor-like kinase (ALK)-3) and BMPR-IB (ALK-6), and type II receptors (BMPR-II). Immunolabeling of pituitary sections revealed the presence of BMPR-IA (ALK-3) and BMPR-II in gonadotrope cells. To investigate the potential effects of BMPs on FSH secretion, ewe pituitary cell cultures were treated with BMP-4 (10−11 M to 10−9 M) for 48 h. Interestingly, FSH release was decreased in a dose-dependent manner. At 10−9 M BMP-4 both FSH concentration and FSHβ mRNA expression were reduced by 40% of control values. In contrast, there was no inhibitory effect on either LH or LHβ mRNA expression. A similar result was found with BMP-6. BMP-4 triggered the phosphorylation of Smad1, suggesting that the effect of BMP-4 on FSH secretion is due to the activation of the BMPs signaling pathway. Furthermore, BMP-4 blocked the stimulatory effect of activin on both FSH release and FSHβ mRNA and amplified the suppression of FSH release and FSHβ mRNA levels induced by 17β-estradiol. These results indicate that a functional BMP system operates within the sheep pituitary, at least in vitro, to decrease FSH release and to modulate the effect of activin.


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