scholarly journals Estrogen-related receptor alpha (ERRα) is a key regulator of intestinal homeostasis and protects against colitis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Allan Tran ◽  
Charlotte Scholtes ◽  
Mario Songane ◽  
Claudia Champagne ◽  
Luc Galarneau ◽  
...  

AbstractThe estrogen-related receptor alpha (ERRα) is a primary regulator of mitochondrial energy metabolism, function and dynamics, and has been implicated in autophagy and immune regulation. ERRα is abundantly expressed in the intestine and in cells of the immune system. However, its role in inflammatory bowel disease (IBD) remains unknown. Here, we report a protective role of ERRα in the intestine. We found that mice deficient in ERRα were susceptible to experimental colitis, exhibiting increased colon inflammation and tissue damage. This phenotype was mediated by impaired compensatory proliferation of intestinal epithelial cells (IEC) following injury, enhanced IEC apoptosis and necrosis and reduced mucus-producing goblet cell counts. Longitudinal analysis of the microbiota demonstrated that loss of ERRα lead to a reduction in microbiome α-diversity and depletion of healthy gut bacterial constituents. Mechanistically, ERRα mediated its protective effects by acting within the radio-resistant compartment of the intestine. It promoted disease tolerance through transcriptional control of key genes involved in intestinal tissue homeostasis and repair. These findings provide new insights on the role of ERRα in the gut and extends our current knowledge of nuclear receptors implicated in IBD.

Author(s):  
Lumin Wei ◽  
Rongjing Zhang ◽  
Jinzhao Zhang ◽  
Juanjuan Li ◽  
Deping Kong ◽  
...  

AbstractProtein kinase A (PKA) plays an important role in regulating inflammation via its catalytic subunits. Recently, PKA regulatory subunits have been reported to directly modulate some signaling pathways and alleviate inflammation. However, the role of PKA regulatory subunits in colonic inflammation remains unclear. Therefore, we conducted this study to investigate the role of the PKA regulatory subunit PRKAR2A in colitis. We observed that PRKAR2A deficiency protected mice from dextran sulfate sodium (DSS)-induced experimental colitis. Our experiments revealed that the intestinal epithelial cell-specific deletion of Prkar2a contributed to this protection. Mechanistically, the loss of PRKAR2A in Prkar2a−/− mice resulted in an increased IFN-stimulated gene (ISG) expression and altered gut microbiota. Inhibition of ISGs partially reversed the protective effects against DSS-induced colitis in Prkar2a−/− mice. Antibiotic treatment and cross-fostering experiments demonstrated that the protection against DSS-induced colitis in Prkar2a−/− mice was largely dependent on the gut microflora. Altogether, our work demonstrates a previously unidentified function of PRKAR2A in promoting DSS-induced colitis.


2007 ◽  
Vol 292 (4) ◽  
pp. L924-L935 ◽  
Author(s):  
Anna A. Birukova ◽  
Panfeng Fu ◽  
Santipongse Chatchavalvanich ◽  
Dylan Burdette ◽  
Olga Oskolkova ◽  
...  

We have previously described protective effects of oxidized 1-palmitoyl-2-arachidonoyl- sn-glycero-3-phosphocholine (OxPAPC) on pulmonary endothelial cell (EC) barrier function and demonstrated the critical role of cyclopentenone-containing modifications of arachidonoyl moiety in OxPAPC protective effects. In this study we used oxidized phosphocholine (OxPAPC), phosphoserine (OxPAPS), and glycerophosphate (OxPAPA) to investigate the role of polar head groups in EC barrier-protective responses to oxidized phospholipids (OxPLs). OxPAPC and OxPAPS induced sustained barrier enhancement in pulmonary EC, whereas OxPAPA caused a transient protective response as judged by measurements of transendothelial electrical resistance (TER). Non-OxPLs showed no effects on TER levels. All three OxPLs caused enhancement of peripheral EC actin cytoskeleton. OxPAPC and OxPAPS completely abolished LPS-induced EC hyperpermeability in vitro, whereas OxPAPA showed only a partial protective effect. In vivo, intravenous injection of OxPAPS or OxPAPC (1.5 mg/kg) markedly attenuated increases in the protein content, cell counts, and myeloperoxidase activities detected in bronchoalveolar lavage fluid upon intratracheal LPS instillation in mice, although OxPAPC showed less potency. All three OxPLs partially attenuated EC barrier dysfunction induced by IL-6 and thrombin. Their protective effects against thrombin-induced EC barrier dysfunction were linked to the attenuation of the thrombin-induced Rho pathway of EC hyperpermeability and stimulation of Rac-mediated mechanisms of EC barrier recovery. These results demonstrate for the first time the essential role of polar OxPL groups in blunting the LPS-induced EC dysfunction in vitro and in vivo and suggest the mechanism of agonist-induced hyperpermeability attenuation by OxPLs via reduction of Rho and stimulation of Rac signaling.


2020 ◽  
Vol 27 (22) ◽  
pp. 3657-3664 ◽  
Author(s):  
Min Shi ◽  
Liang Ma ◽  
Ping Fu

Accumulating evidences indicated that obesity and metabolic syndrome were independent risk factors for the development and progression of kidney diseases. Apart from inflammation, lipotoxicity, and hemodynamic factors, adipokines have been proposed to play crucial roles in the relationship between kidney diseases and metabolic disorders. As one of the key adipokines, fatty acid binding protein 4 (FABP4), which is mainly expressed in adipocytes and macrophages, has recently been shown to be associated with renal dysfunction and kidney damage. Both clinical and experimental studies have proposed circulating FABP4 as a novel predictor for renal injuries, and it might also be a predictor for cardiovascular events in patients with end stage renal disease (ESRD). FABP4 has also been detected in the glomerular cells and epithelial tubular cells in mouse and human kidneys, and the expression of FABP4 in these cells has been involved in the pathogenesis of kidney diseases. In addition, experimental studies suggested that inhibition of FABP4 had protective effects on renal damage. Here, we reviewed current knowledge regarding the role of FABP4 in pathophysiological insights as well as its potential function as a predictor and therapeutic target for kidney diseases.


2011 ◽  
Vol 29 (15_suppl) ◽  
pp. e16009-e16009
Author(s):  
K. S. Gopinath ◽  
S. Swamy ◽  
A. Nagashri ◽  
K. G. Srinivas

2011 ◽  
Author(s):  
Véronique Giroux ◽  
Gérald Bernatchez ◽  
Thomas Lassalle ◽  
Jean-François Beaulieu ◽  
Julie C. Carrier

2015 ◽  
Vol 309 (12) ◽  
pp. L1420-L1429 ◽  
Author(s):  
Biji Mathew ◽  
Daisuke Takekoshi ◽  
Saad Sammani ◽  
Yulia Epshtein ◽  
Rajesh Sharma ◽  
...  

We previously reported protective effects of GADD45a (growth arrest and DNA damage-inducible gene 45 alpha) in murine ventilator-induced lung injury (VILI) via effects on Akt-mediated endothelial cell signaling. In the present study we investigated the role of GADD45a in separate murine models of radiation- and bleomycin-induced lung injury. Initial studies of wild-type mice subjected to single-dose thoracic radiation (10 Gy) confirmed a significant increase in lung GADD45a expression within 24 h and persistent at 6 wk. Mice deficient in GADD45a (GADD45a−/−) demonstrated increased susceptibility to radiation-induced lung injury (RILI, 10 Gy) evidenced by increased bronchoalveolar lavage (BAL) fluid total cell counts, protein and albumin levels, and levels of inflammatory cytokines compared with RILI-challenged wild-type animals at 2 and 4 wk. Furthermore, GADD45a−/− mice had decreased total and phosphorylated lung Akt levels both at baseline and 6 wk after RILI challenge relative to wild-type mice while increased RILI susceptibility was observed in both Akt+/− mice and mice treated with an Akt inhibitor beginning 1 wk prior to irradiation. Additionally, overexpression of a constitutively active Akt1 transgene reversed RILI-susceptibility in GADD45a−/− mice. In separate studies, lung fibrotic changes 2 wk after treatment with bleomycin (0.25 U/kg IT) was significantly increased in GADD45a−/− mice compared with wild-type mice assessed by lung collagen content and histology. These data implicate GADD45a as an important modulator of lung inflammatory responses across different injury models and highlight GADD45a-mediated signaling as a novel target in inflammatory lung injury clinically.


Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2603
Author(s):  
Maristella Donato ◽  
Elisabetta Faggin ◽  
Francesco Cinetto ◽  
Carla Felice ◽  
Maria Giovanna Lupo ◽  
...  

Cardiovascular calcification is the ectopic deposition of calcium-phosphate crystals within the arterial wall and the aortic valve leaflets. This pathological process leads to increased vascular stiffness, reduced arterial elasticity, and aortic valve stenosis, increasing the risk of cardiovascular diseases. Although cardiovascular calcification is an increasing health care burden, to date no medical therapies have been approved for treating or preventing it. Considering the current lack of therapeutic strategies and the increasing prevalence of cardiovascular calcification, the investigation of some nutraceuticals to prevent this pathological condition has become prevalent in recent years. Recent preclinical and clinical studies evaluated the potential anti-calcific role of nutraceuticals (including magnesium, zinc, iron, vitamin K, and phytate) in the progression of vascular calcification, providing evidence for their dietary supplementation, especially in high-risk populations. The present review summarizes the current knowledge and latest advances for nutraceuticals with the most relevant preclinical and clinical data, including magnesium, zinc, iron, vitamin K, and phytate. Their supplementation might be recommended as a cost-effective strategy to avoid nutritional deficiency and to prevent or treat cardiovascular calcification. However, the optimal dose of nutraceuticals has not been identified and large interventional trials are warranted to support their protective effects on cardiovascular disease.


2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.


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