scholarly journals Overexpression of transforming growth factor-beta 1 mRNA is associated with up-regulation of glomerular tenascin and laminin gene expression in nonobese diabetic mice.

1995 ◽  
Vol 5 (8) ◽  
pp. 1610-1617
Author(s):  
C W Yang ◽  
M Hattori ◽  
H Vlassara ◽  
C J He ◽  
M A Carome ◽  
...  

Nonobese diabetic (NOD) mice spontaneously develop immune-mediated insulin-dependent diabetes mellitus and nephropathy, providing an opportunity to study the early molecular events in a model of diabetic glomerulosclerosis. The expression of several genes coding for growth factors and extracellular matrix was examined in microdissected glomeruli, by the use of reverse transcription-competitive polymerase chain reaction, in diabetic NOD mice (mean duration of diabetes, 28.5 +/- 7 days) and age-matched nondiabetic NOD mice with normal glucose tolerance. The levels of mRNA coding for transforming growth factor-beta 1, tenascin, and laminin B1 increased 1.9-, 2.0-, and 1.7-fold, respectively, whereas platelet-derived growth factor (PDGF)-B, alpha 1(IV) collagen, 72-kd collagenase, alpha-smooth muscle actin, and beta-actin mRNA remained stable in the diabetic mice. The kidney advanced glycosylation end-products levels increased 2.1-fold in the diabetic mice, and the diabetic glomeruli showed an accumulation of tenascin and laminin but not of type IV collagen by immunofluorescence microscopy. There was no increase in cell number per glomerulus after the onset of diabetes, a finding consistent with stable PDGF-B and alpha-smooth muscle actin mRNA levels. These findings provide evidence that increased glomerular transforming growth factor-beta 1, but not PDGF-B, mRNA is associated with the up-regulation of tenascin and laminin expression after advanced glycosylation endproduct accumulation, early after the onset of diabetes.

Author(s):  
Yedan Liu ◽  
Huawei Zhang ◽  
Shaoxun Wang ◽  
Ya Guo ◽  
Xing Fang ◽  
...  

Diabetes mellitus (DM) is one of the primary pathological factors that contributes to aging-related cognitive impairments, but the underlying mechanisms remain unclear. We recently reported that old DM rats exhibited impaired myogenic responses of the cerebral arteries and arterioles, poor cerebral blood flow autoregulation, enhanced blood-brain barrier (BBB) leakage, and cognitive impairments. These changes were associated with diminished vascular smooth muscle cell contractile capability linked to elevated reactive oxygen species (ROS) and reduced ATP production. The present study, using a non-obese T2DN DM rat, isolated parenchymal arterioles (PAs), and cultured cerebral microvascular pericytes, examined whether cerebrovascular pericyte in DM is damaged and whether pericyte dysfunction may play a role in the regulation of cerebral hemodynamics and BBB integrity. We found that ROS and mitochondrial superoxide production were elevated in PAs isolated from old DM rats and in high glucose (HG)-treated alpha-smooth muscle actin positive pericytes. HG-treated pericytes displayed decreased contractile capability in association with diminished mitochondrial respiration and ATP production. Additionally, the expression of advanced glycation end products, transforming growth factor-beta, vascular endothelial growth factor, and fibronectin were enhanced, but claudin 5 and integrin β1 was reduced in the brain of old DM rats and HG-treated pericytes. Further, endothelial tight junction and pericyte coverage on microvessels were reduced in the cortex of old DM rats. These results demonstrate our previous findings that the impaired cerebral hemodynamics and BBB leakage and cognitive impairments in the same old DM model are associated with hyperglycemia-induced cerebrovascular pericyte dysfunction.


1994 ◽  
Vol 42 (8) ◽  
pp. 1061-1070 ◽  
Author(s):  
T D Perdue ◽  
A R Brody

We are studying the development of fibrogenic lesions in the lungs of rats exposed briefly to an aerosol of chrysotile asbestos fibers. This model of asbestosis has enabled us to establish very early cellular events at the specific locations where interstitial fibrosis will develop. These sites, the first alveolar duct bifurcations, are where the fibers are initially deposited and where macrophages first accumulate. In the studies presented here, we used immunohistochemical techniques to show that these macrophages exhibit strong localization of transforming growth factor-beta. In the adjacent developing fibrogenic lesions a clear increase in fibronectin staining was demonstrated and morphological analysis indicated a significant increase in amounts of smooth muscle actin. Such studies are essential in furthering our understanding of the distribution of potential mediators of the fibrogenic process and the cellular responses they elicit during the pathogenesis of disease.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Farouk K. El-Baz ◽  
Abeer Salama ◽  
Sami I. Ali ◽  
Rania Elgohary

Hepatic fibrosis is a consequence of chronic liver diseases. Metalloproteinase and its inhibitor have crucial roles in the resolution of liver fibrosis. The current relevant study is aimed to evaluate the therapeutic effect of Haematococcus pluvialis (H. pluvialis) extract, astaxanthin-rich fraction, astaxanthin ester-rich fraction, and β-carotene-rich fraction as well as their mechanisms of action in curing hepatic fibrosis induced by thioacetamide (TAA). Liver fibrosis was induced using TAA (intraperitoneal injection, two times a week for 6 weeks), in a rat model and H. pluvialis extract (200 mg/kg), and other fractions (30 mg/kg) were orally administered daily for 4 weeks after the last TAA injection. Based on HPLC analysis, H. pluvialis extract contains β-carotene (12.95 mg/g, extract) and free astaxanthin (10.85 mg/g, extract), while HPLC/ESI-MS analysis revealed that H. pluvialis extract contains 28 carotenoid compounds including three isomers of free astaxanthin, α or β-carotene, lutein, 14 astaxanthin mono-esters, 5 astaxanthin di-esters, and other carotenoids. H. pluvialis and its fractions reduced liver enzymes, nitric oxide, collagen 1, alpha-smooth muscle actin, and transforming growth factor-beta as well as elevated catalase antioxidant activity compared to the TAA group. Also, H. pluvialis extract and its fractions exceedingly controlled the balance between metalloproteinase and its inhibitor, activated Kupffer cells proliferation, and suppressed liver apoptosis, necrobiosis, and fibrosis. These findings conclude that H. pluvialis extract and its fractions have an antifibrotic effect against TAA-induced liver fibrosis by regulating the oxidative stress and proinflammatory mediators, suppressing multiple profibrogenic factors, and modulating the metalloproteinase and its inhibitor pathway, recommending H. pluvialis extract and its fractions for the development of new effective medicine for treating hepatic fibrosis disorders.


Author(s):  
Russell Gould ◽  
Karen Chin ◽  
Puifai Santisakultam ◽  
Amanda Dropkin ◽  
Jennifer Richards ◽  
...  

In this work, we demonstrate the unique effect of controlled anisotropic strain on fibroblast behavior in 3D engineered tissue environments. Anisotropy of biaxial strain resulted in increased cellular orientation and collagen fiber alignment. Transforming growth factor beta-1 (TGFβ1) gene expression and pSmad2 nuclear translocation increased with biaxial directionality. Myofibroblastic alpha-smooth muscle actin (α-SMA) decreased with applied strain similar to mechanically unloaded hydrogels. Collectively, these results demonstrate a novel mechanobiological mechanism by which fibroblasts develop rapid anisotropic matrix striation while maintaining phenotype quiescence.


2021 ◽  
Vol 14 (4) ◽  
pp. 1841-1862
Author(s):  
Sally A El Awdan ◽  
Gihan F. Asaad

Liver fibrosis is considered: “a pathological repairing process in liver injuries leading to extracellular cell matrix (ECM) accumulation evidencing chronic liver diseases”. Chronic viral hepatitis, alcohol consumption, autoimmune diseases as well as non-alcoholic steatohepatitis are from the main causes of liver fibrosis (Lee et al., 2015; Mieli-Vergani et al., 2018). Hepatic stellate cells (HSCs) exist in the sinus space next to the hepatic epithelial cells as well as endothelial cells (Yin et al., 2013). Normally, HSCs are quiescent and mainly participate in fat storage and in the metabolism of vitamin A. HSCs are produced during liver injury and then transformed into myofibroblasts. The activated HSCs resulted in a sequence of events considered as marks fibrosis. The activation of HSCs mostly express alpha smooth muscle actin (α-SMA). Moreover, ECM is synthesized and secreted by HSCs that affects markedly the structure and function of the liver tissue leading to fibrosis (Tsuchida et al., 2017; Han et al., 2020). Hence, activated HSCs are attracting attention as potential targets in liver fibrosis. Many signaling molecules are involved in HSCs activation first and foremost, platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β) (Tsuchida et al., 2017; Wang et al., 2020c) as interfering the PDGF or TGF-β signaling pathways is a growing field for liver fibrosis treatment.


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