scholarly journals Acetoacetate protects macrophages from lactic acidosis-induced mitochondrial dysfunction by metabolic reprograming

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Clément Adam ◽  
Léa Paolini ◽  
Naïg Gueguen ◽  
Guillaume Mabilleau ◽  
Laurence Preisser ◽  
...  

AbstractLactic acidosis, the extracellular accumulation of lactate and protons, is a consequence of increased glycolysis triggered by insufficient oxygen supply to tissues. Macrophages are able to differentiate from monocytes under such acidotic conditions, and remain active in order to resolve the underlying injury. Here we show that, in lactic acidosis, human monocytes differentiating into macrophages are characterized by depolarized mitochondria, transient reduction of mitochondrial mass due to mitophagy, and a significant decrease in nutrient absorption. These metabolic changes, resembling pseudostarvation, result from the low extracellular pH rather than from the lactosis component, and render these cells dependent on autophagy for survival. Meanwhile, acetoacetate, a natural metabolite produced by the liver, is utilized by monocytes/macrophages as an alternative fuel to mitigate lactic acidosis-induced pseudostarvation, as evidenced by retained mitochondrial integrity and function, retained nutrient uptake, and survival without the need of autophagy. Our results thus show that acetoacetate may increase tissue tolerance to sustained lactic acidosis.

2013 ◽  
Author(s):  
K Alexander Iwen ◽  
Erich Schroder ◽  
Julia Resch ◽  
Ulrich Lindner ◽  
Peter Konig ◽  
...  

2020 ◽  
Vol 22 (1) ◽  
pp. 91
Author(s):  
Vanina Romanello

Sarcopenia is a chronic disease characterized by the progressive loss of skeletal muscle mass, force, and function during aging. It is an emerging public problem associated with poor quality of life, disability, frailty, and high mortality. A decline in mitochondria quality control pathways constitutes a major mechanism driving aging sarcopenia, causing abnormal organelle accumulation over a lifetime. The resulting mitochondrial dysfunction in sarcopenic muscles feedbacks systemically by releasing the myomitokines fibroblast growth factor 21 (FGF21) and growth and differentiation factor 15 (GDF15), influencing the whole-body homeostasis and dictating healthy or unhealthy aging. This review describes the principal pathways controlling mitochondrial quality, many of which are potential therapeutic targets against muscle aging, and the connection between mitochondrial dysfunction and the myomitokines FGF21 and GDF15 in the pathogenesis of aging sarcopenia.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1552
Author(s):  
Mariona Guitart-Mampel ◽  
Pedro Urquiza ◽  
Jordana I. Borges ◽  
Anastasios Lymperopoulos ◽  
Maria E. Solesio

The mineralocorticoid aldosterone regulates electrolyte and blood volume homeostasis, but it also adversely modulates the structure and function of the chronically failing heart, through its elevated production in chronic human post-myocardial infarction (MI) heart failure (HF). By activating the mineralocorticoid receptor (MR), a ligand-regulated transcription factor, aldosterone promotes inflammation and fibrosis of the heart, while increasing oxidative stress, ultimately induding mitochondrial dysfunction in the failing myocardium. To reduce morbidity and mortality in advanced stage HF, MR antagonist drugs, such as spironolactone and eplerenone, are used. In addition to the MR, aldosterone can bind and stimulate other receptors, such as the plasma membrane-residing G protein-coupled estrogen receptor (GPER), further complicating it signaling properties in the myocardium. Given the salient role that adrenergic receptor (ARs)—particularly βARs—play in cardiac physiology and pathology, unsurprisingly, that part of the impact of aldosterone on the failing heart is mediated by its effects on the signaling and function of these receptors. Aldosterone can significantly precipitate the well-documented derangement of cardiac AR signaling and impairment of AR function, critically underlying chronic human HF. One of the main consequences of HF in mammalian models at the cellular level is the presence of mitochondrial dysfunction. As such, preventing mitochondrial dysfunction could be a valid pharmacological target in this condition. This review summarizes the current experimental evidence for this aldosterone/AR crosstalk in both the healthy and failing heart, and the impact of mitochondrial dysfunction in HF. Recent findings from signaling studies focusing on MR and AR crosstalk via non-conventional signaling of molecules that normally terminate the signaling of ARs in the heart, i.e., the G protein-coupled receptor-kinases (GRKs), are also highlighted.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lauren A. Callender ◽  
Johannes Schroth ◽  
Elizabeth C. Carroll ◽  
Conor Garrod-Ketchley ◽  
Lisa E. L. Romano ◽  
...  

AbstractGATA3 is as a lineage-specific transcription factor that drives the differentiation of CD4+ T helper 2 (Th2) cells, but is also involved in a variety of processes such as immune regulation, proliferation and maintenance in other T cell and non-T cell lineages. Here we show a mechanism utilised by CD4+ T cells to increase mitochondrial mass in response to DNA damage through the actions of GATA3 and AMPK. Activated AMPK increases expression of PPARG coactivator 1 alpha (PPARGC1A or PGC1α protein) at the level of transcription and GATA3 at the level of translation, while DNA damage enhances expression of nuclear factor erythroid 2-related factor 2 (NFE2L2 or NRF2). PGC1α, GATA3 and NRF2 complex together with the ATR to promote mitochondrial biogenesis. These findings extend the pleotropic interactions of GATA3 and highlight the potential for GATA3-targeted cell manipulation for intervention in CD4+ T cell viability and function after DNA damage.


2016 ◽  
Vol 4 (19) ◽  
pp. e12988 ◽  
Author(s):  
Kerstin Lohr ◽  
Fiona Pachl ◽  
Amin Moghaddas Gholami ◽  
Kerstin E. Geillinger ◽  
Hannelore Daniel ◽  
...  

2012 ◽  
Vol 3 ◽  
Author(s):  
Kinga K. Hosszu ◽  
Alisa Valentino ◽  
Yan Ji ◽  
Mara Matkovic ◽  
Lina Pednekar ◽  
...  

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yoshiyuki Ikeda ◽  
Junichi Sadoshima

Fission and fusion affect mitochondrial turnover in part by modulating mitophagy. This study aimed to clarify the role of mitochondrial fission in regulating cardiac function and autophagy in the heart. Dynamin-related protein 1 (Drp-1) plays an essential role in mediating mitochondrial fission. Therefore, we generated cardiac specific Drp-1 KO mice and utilized cultured cardiomyocytes transduced with adenovirus harboring short hairpin Drp-1 (Ad-shDrp-1) to test the effect of Drp-1 disruption both in vivo and in vitro. In Drp-1 KO hearts we observed a significantly greater mitochondrial mass ratio compared to control, as assessed by electron microscopy (Drp-1 KO: 3.57 ± 1.38, control: 1.18 ± 0.31, P<0.05). Mitochondrial ATP content was significantly lower (0.70 ± 0.07 vs 1.03 ± 0.10, P<0.05), while mitochondrial swelling was significantly greater (% decrease in absorbance; 8.01 ± 1.99 vs 2.01 ± 0.58, P<0.05) in Drp-1 KO hearts versus control. Mitochondrial membrane potential, assessed by JC-1 staining, was significantly reduced in myocytes with knockdown of Drp-1. Taken together, these results suggest that inhibition of fission causes mitochondrial dysfunction. We also examined the effect of Drp-1 depletion on autophagy. We found that the amount of LC-3 II was significantly less (0.47 ± 0.16 vs 1.32 ±0.34, P<0.05), whereas p62 expression was significantly greater (1.14 ± 0.16 vs 0.16 ± 0.06, P<0.01) in Drp-1 KO hearts compared to control. The number of LC3 dots in Ad-shDrp-1 transduced myocytes was lower than that of sh-scramble treatment. We investigated apoptosis and found that the amount of cleaved caspase-3 (0.62 ± 0.24 vs 0.18 ± 0.04, P<0.05) and the number of TUNEL positive cells (0.22 ± 0.12 vs 0.03 ± 0.06%, P<0.01) were higher in Drp-1 KO versus control hearts. Cardiac systolic function was reduced (ejection fraction; 44.5 ± 6.3 vs 85.4 ± 5.7%, P<0.01) and LVW/tibia length was greater (4.48 ± 0.38 vs 3.84 ± 0.58, P<0.05) in Drp-1 KO mice compared to control. Finally, we observed that the survival rate of Drp-1 KO mice was significantly reduced compared to control mice. Our results demonstrate that inhibition of mitochondrial fission via disruption of Drp-1 inhibits autophagy and causes mitochondrial dysfunction, thereby promoting cardiomyopathy.


1998 ◽  
Vol 5 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Mariangela Mancini ◽  
Monireh Sedghinasab ◽  
Katya Knowlton ◽  
Amy Tam ◽  
David Hockenberg ◽  
...  

Author(s):  
Tom Tanjeko Ajime ◽  
Jef Serré ◽  
Rob C I Wüst ◽  
Guy Anselme Mpaka Messa ◽  
Chiel Poffé ◽  
...  

Abstract Introduction Apart from its adverse effects on the respiratory system, cigarette smoking also induces skeletal muscle atrophy and dysfunction. Whether short-term smoking cessation can restore muscle mass and function is unknown. We, therefore, studied the impact of 1- and 2-week smoking cessation on skeletal muscles in a mouse model. Methods Male mice were divided into four groups: Air-exposed (14 weeks); cigarette smoke (CS)-exposed (14 weeks); CS-exposed (13 weeks) followed by 1-week cessation; CS-exposed (12 weeks) followed by 2 weeks cessation to examine exercise capacity, physical activity levels, body composition, muscle function, capillarization, mitochondrial function and protein expression in the soleus, plantaris, and diaphragm muscles. Results CS-induced loss of body and muscle mass was significantly improved within 1 week of cessation due to increased lean and fat mass. Mitochondrial respiration and protein levels of the respiratory complexes in the soleus were lower in CS-exposed mice, but similar to control values after 2 weeks of cessation. Exposing isolated soleus muscles to CS extracts reduced mitochondrial respiration that was reversed after removing the extract. While physical activity was reduced in all groups, exercise capacity, limb muscle force, fatigue resistance, fiber size and capillarization, and diaphragm cytoplasmic HIF-1α were unaltered by CS-exposure. However, CS-induced diaphragm atrophy and increased capillary density were not seen after 2 weeks of smoking cessation. Conclusion In male mice, 2 weeks of smoking cessation reversed smoking-induced mitochondrial dysfunction, limb muscle mass loss, and diaphragm muscle atrophy, highlighting immediate benefits of cessation on skeletal muscles. Implications Our study demonstrates that CS-induced skeletal muscle mitochondrial dysfunction and atrophy are significantly improved by 2 weeks of cessation in male mice. We show for the first time that smoking cessation as short as 1 to 2 weeks is associated with immediate beneficial effects on skeletal muscle structure and function with the diaphragm being particularly sensitive to CS-exposure and cessation. This could help motivate smokers to quit smoking as early as possible. The knowledge that smoking cessation has potential positive extrapulmonary effects is particularly relevant for patients referred to rehabilitation programs and those admitted to hospitals suffering from acute or chronic muscle deterioration yet struggling with smoking cessation.


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