scholarly journals TGFβ (Transforming Growth Factor-Beta)–Activated Kinase 1 Regulates Arteriovenous Fistula Maturation

Author(s):  
Haidi Hu ◽  
Shin-Rong Lee ◽  
Hualong Bai ◽  
Jianming Guo ◽  
Takuya Hashimoto ◽  
...  

Objective: Arteriovenous fistulae (AVF) are the optimal conduit for hemodialysis access but have high rates of primary maturation failure. Successful AVF maturation requires wall thickening with deposition of ECM (extracellular matrix) including collagen and fibronectin, as well as lumen dilation. TAK1 (TGFβ [transforming growth factor-beta]–activated kinase 1) is a mediator of noncanonical TGFβ signaling and plays crucial roles in regulation of ECM production and deposition; therefore, we hypothesized that TAK1 regulates wall thickening and lumen dilation during AVF maturation. Approach and Results: In both human and mouse AVF, immunoreactivity of TAK1, JNK (c-Jun N-terminal kinase), p38, collagen 1, and fibronectin was significantly increased compared with control veins. Manipulation of TAK1 in vivo altered AVF wall thickening and luminal diameter; reduced TAK1 function was associated with reduced thickness and smaller diameter, whereas activation of TAK1 function was associated with increased thickness and larger diameter. Arterial magnitudes of laminar shear stress (20 dyne/cm 2 ) activated noncanonical TGFβ signaling including TAK1 phosphorylation in mouse endothelial cells. Conclusions: TAK1 is increased in AVF, and TAK1 manipulation in a mouse AVF model regulates AVF thickness and diameter. Targeting noncanonical TGFβ signaling such as TAK1 might be a novel therapeutic approach to improve AVF maturation.

1988 ◽  
Vol 91 (2) ◽  
pp. 313-318
Author(s):  
T. Lombardi ◽  
R. Montesano ◽  
M.B. Furie ◽  
S.C. Silverstein ◽  
L. Orci

Cultured endothelial cells isolated from fenestrated capillaries express many properties characteristic of their in vivo differentiated phenotype, including the formation of a limited number of fenestrae. In this study, we have investigated whether physiological factors that control cell differentiation might regulate the surface density of fenestrae in capillary endothelial cells. We have found that treatment of the cultures with retinoic acid (10 microM) induces a more than threefold increase in the surface density of endothelial fenestrae, whereas transforming growth factor beta (TGF beta) (2 ng ml-1) causes a sevenfold decrease in the surface density of these structures. These results show that the expression of endothelial fenestrae is susceptible to bidirectional modulation by physiological signals, and suggest that retinoids and TGF beta may participate in the regulation of fenestral density of capillary endothelium in vivo.


1991 ◽  
Vol 173 (5) ◽  
pp. 1121-1132 ◽  
Author(s):  
R A Fava ◽  
N J Olsen ◽  
A E Postlethwaite ◽  
K N Broadley ◽  
J M Davidson ◽  
...  

We have studied the consequences of introducing human recombinant transforming growth factor beta 1 (hrTGF-beta 1) into synovial tissue of the rat, to begin to better understand the significance of the fact that biologically active TGF-beta is found in human arthritic synovial effusions. Within 4-6 h after the intra-articular injection of 1 microgram of hrTGF-beta 1 into rat knee joints, extensive recruitment of polymorphonuclear leukocytes (PMNs) was observed. Cytochemistry and high resolution histological techniques were used to quantitate the influx of PMNs, which peaked 6 h post-injection. In a Boyden chamber assay, hrTGF-beta 1 at 1-10 fg/ml elicited a chemotactic response from PMNs greater in magnitude than that evoked by FMLP, establishing that TGF-beta 1 is an effective chemotactic agent for PMNs in vitro as well as in vivo. That PMNs may represent an important source of TGF-beta in inflammatory infiltrates was strongly suggested by a demonstration that stored TGF-beta 1 was secreted during phorbol myristate acetate-stimulated degranulation in vitro. Acid/ethanol extracts of human PMNs assayed by ELISA contained an average of 355 ng of TGF/beta 1 per 10(9) cells potentially available for secretion during degranulation of PMNs. [3H]Thymidine incorporation in vivo and autoradiography of tissue sections revealed that widespread cell proliferation was triggered by TGF-beta 1 injection. Synovial lining cells and cells located deep within the subsynovial connective tissue were identified as sources of at least some of the new cells that contribute to TGF-beta 1-induced hyperplasia. Our results demonstrate that TGF-beta is capable of exerting pathogenic effects on synovial tissue and that PMNs may represent a significant source of the TGF-beta present in synovial effusions.


Cilia ◽  
2012 ◽  
Vol 1 (S1) ◽  
Author(s):  
S Christensen ◽  
CA Clement ◽  
SK Brorsen ◽  
KD Ajbro ◽  
M de Jesus ◽  
...  

1991 ◽  
Vol 174 (3) ◽  
pp. 539-545 ◽  
Author(s):  
J S Silva ◽  
D R Twardzik ◽  
S G Reed

The effects of transforming growth factor beta (TGF-beta) on interferon gamma-mediated killing of the intracellular protozoan parasite Trypanosoma cruzi and on the course of T. cruzi infection in mice were investigated. Spleen cells from mice with acute T. cruzi infections were found to produce elevated levels of biologically active TGF-beta in vitro, and the possibility that TGF-beta may mediate certain aspects of T. cruzi infection was then addressed. When mouse peritoneal macrophages were treated with TGF-beta in vitro, the ability of IFN-gamma to activate intracellular inhibition of the parasite was blocked. This occurred whether cells were treated with TGF-beta either before or after IFN-gamma treatment. TGF-beta treatment also blocked the T. cruzi-inhibiting effects of IGN-gamma on human macrophages. Additionally, treatment of human macrophages with TGF-beta alone led to increased parasite replication in these cells. The effects of TGF-beta on T. cruzi infection in vivo were then investigated. Susceptible C57BL/6 mice developed higher parasitemias and died earlier when treated with TGF-beta during the course of infection. Resistant C57BL/6 x DBA/2 F1 mice treated with TGF-beta also had increased parasitemias, and 50% mortality, compared with no mortality in infected, saline-treated controls. A single dose of TGF-beta, given at the time of infection, was sufficient to significantly decrease resistance to infection in F1 mice and to exacerbate infection in susceptible C57BL/6 mice. Furthermore, a single injection of TGF-beta was sufficient to counter the in vivo protective effects of IFN-gamma. We conclude that TGF-beta, produced during acute T. cruzi infection in mice, is a potent inhibitor of the effects of macrophage activating cytokines in vivo and in vitro and may play a role in regulating infection.


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