scholarly journals The Circadian Clock Protein BMAL1 Acts as a Metabolic Sensor In Macrophages to Control the Production of Pro IL-1β

2021 ◽  
Vol 12 ◽  
Author(s):  
George A. Timmons ◽  
Richard G. Carroll ◽  
James R. O’Siorain ◽  
Mariana P. Cervantes-Silva ◽  
Lauren E. Fagan ◽  
...  

The transcription factor BMAL1 is a clock protein that generates daily or circadian rhythms in physiological functions including the inflammatory response of macrophages. Intracellular metabolic pathways direct the macrophage inflammatory response, however whether the clock is impacting intracellular metabolism to direct this response is unclear. Specific metabolic reprogramming of macrophages controls the production of the potent pro-inflammatory cytokine IL-1β. We now describe that the macrophage molecular clock, through Bmal1, regulates the uptake of glucose, its flux through glycolysis and the Krebs cycle, including the production of the metabolite succinate to drive Il-1β production. We further demonstrate that BMAL1 modulates the level and localisation of the glycolytic enzyme PKM2, which in turn activates STAT3 to further drive Il-1β mRNA expression. Overall, this work demonstrates that BMAL1 is a key metabolic sensor in macrophages, and its deficiency leads to a metabolic shift of enhanced glycolysis and mitochondrial respiration, leading to a heightened pro-inflammatory state. These data provide insight into the control of macrophage driven inflammation by the molecular clock, and the potential for time-based therapeutics against a range of chronic inflammatory diseases.

2015 ◽  
Vol 213 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Luke A.J. O’Neill ◽  
Edward J. Pearce

Recent studies on intracellular metabolism in dendritic cells (DCs) and macrophages provide new insights on the functioning of these critical controllers of innate and adaptive immunity. Both cell types undergo profound metabolic reprogramming in response to environmental cues, such as hypoxia or nutrient alterations, but importantly also in response to danger signals and cytokines. Metabolites such as succinate and citrate have a direct impact on the functioning of macrophages. Immunogenicity and tolerogenicity of DCs is also determined by anabolic and catabolic processes, respectively. These findings provide new prospects for therapeutic manipulation in inflammatory diseases and cancer.


2020 ◽  
Vol 21 (2) ◽  
pp. 254-266 ◽  
Author(s):  
Khandan Ilkhani ◽  
Milad Bastami ◽  
Soheila Delgir ◽  
Asma Safi ◽  
Shahrzad Talebian ◽  
...  

: Metabolic reprogramming is a significant property of various cancer cells, which most commonly arises from the Tumor Microenvironment (TME). The events of metabolic pathways include the Warburg effect, shifting in Krebs cycle metabolites, and the rate of oxidative phosphorylation, potentially providing energy and structural requirements for the development and invasiveness of cancer cells. TME and tumor metabolism shifting have a close relationship through bidirectional signaling pathways between stromal and tumor cells. Cancer- Associated Fibroblasts (CAFs), as the most dominant cells of TME, play a crucial role in the aberrant metabolism of cancer. Furthermore, the stated relationship can affect survival, progression, and metastasis in cancer development. Recently, exosomes are considered one of the most prominent factors in cellular communications considering effective content and bidirectional mediatory effect between tumor and stromal cells. In this regard, CAF-Derived Exosomes (CDE) exhibit an efficient obligation to induce metabolic reprogramming for promoting growth and metastasis of cancer cells. The understanding of cancer metabolism, including factors related to TME, could lead to the discovery of a potential biomarker for diagnostic and therapeutic approaches in cancer management. This review focuses on the association between metabolic reprogramming and engaged microenvironmental, factors such as CAFs, and the associated derived exosomes.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
F Canonico ◽  
R Vinci ◽  
D Pedicino ◽  
E Pisano ◽  
P Ciampi ◽  
...  

Abstract Background Several studies suggest that an alteration of monocyte metabolism might be implicated in inflammatory diseases. Enhanced glycolysis might be a hallmark of pro-inflammatory monocyte subsets. Improved glycolysis enables the immune cells to generate sufficient ATP and biosynthetic intermediates to carry out its particular effector functions. For macrophages this includes phagocytosis and inflammatory cytokine production. Pyruvate Kinase isozyme M2 (PKM-2) catalyzes the final step of glycolysis producing pyruvate and ATP. Latest studies have shown that a member of Jumonji family (JMJD8) acts as a positive regulator in TNF-induced NF-kB signaling leading to pro-inflammatory pathways in macrophages and is involved in angiogenesis and cellular metabolism through interacting with PKM-2 in endothelial cells. Purpose The aims of the study are to assess the expression of the glycolytic key enzyme PKM-2 in CD14+ monocytes obtained from patients with non-ST-elevation myocardial infarction (NSTEMI) or with stable angina (SA). Furthermore, the expression of JMJD8 was evaluated. Methods 30 patients with NSTEMI and 30 patients with SA were enrolled. Peripheral blood mononuclear cells were obtained from whole blood samples. For cytoplasmatic protein identification, cells were fixed and permeabilized and then incubated with fluorochrome-conjugated mAbs anti-CD14, anti-PKM-2 and anti-JMJD8. For analysis we used Two-tailed Mann-Whitney non parametric Comparison test. Results CD14+ monocytes from NSTEMI patients showed reduced expression of the key glycolytic enzyme PKM-2 as compared to CD14+ monocytes from SA patients (p=0.02) (Figure 1). JMJD8 expression in NSTEMI patients is increased compared with SA patients (p=0.02) (Figure 2). Conclusion This study introduces a role for immune-metabolism in the immunity dysregulation described in ACS patients and provides novel insights into the mechanisms responsible for coronary instability. Taking their potential interaction into account, our data suggest that in acute setting glycolysis key enzyme PKM2 expression is downregulated. Besides, JMJD8 protein levels increase in NSTEMI patients acting as potential limiting factor of PKM2 function. Moreover, our data propose the potential roles of immune-metabolism to detect novel therapeutic targets, associated with an accurate patient stratification based on immune-metabolic profiles, for prevention and treatment of atherosclerosis, in the perspective of a personalized medicine approach. Funding Acknowledgement Type of funding source: Private hospital(s). Main funding source(s): Fondazione Policlinico A. Gemelli


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1704
Author(s):  
Diego Angosto-Bazarra ◽  
Cristina Molina-López ◽  
Alejandro Peñín-Franch ◽  
Laura Hurtado-Navarro ◽  
Pablo Pelegrín

Inflammasomes are immune cytosolic oligomers involved in the initiation and progression of multiple pathologies and diseases. The tight regulation of these immune sensors is necessary to control an optimal inflammatory response and recover organism homeostasis. Prolonged activation of inflammasomes result in the development of chronic inflammatory diseases, and the use of small drug-like inhibitory molecules are emerging as promising anti-inflammatory therapies. Different aspects have to be taken in consideration when designing inflammasome inhibitors. This review summarizes the different techniques that can be used to study the mechanism of action of potential inflammasome inhibitory molecules.


2021 ◽  
Vol 28 ◽  
Author(s):  
Thaise Martins ◽  
Bruno M. Fonseca ◽  
Irene Rebelo

: Reactive oxygen/nitrogen species (ROS/RNS) are produced physiologically by several mechanisms, especially during the inflammatory response. However, their overproduction can lead to the evolution of conditions known as oxidative/nitrosative stress, resulting in the establishment of chronic inflammatory diseases. Chalcones are considered as a class of flavonoids having the molecular pattern 1,3-diaryl-2-propen-1-one. In the last few years, the antioxidant property of chalcones has been extensively studied, mainly due to their ability to inhibit the production or scavenging ROS/RNS. The present review demonstrated and discussed the antioxidant activity of chalcones, focusing on the production of ROS/RNS during the inflammatory response. This literature revision was based on the modulatory effects of chalcones against different enzymes, such as superoxide dismutase (SOD), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, catalase (CAT), myeloperoxidase (MPO), and inducible nitric oxide synthase (iNOS) and, in the scavenging of ROS/RNS. Whenever possible, the structure-activity relationship (SAR) was established. Through the analysis accomplished in this review, it can be observed that the presence of substituents, e.g., hydroxyl, methoxyl, prenyl, and halogen atoms in the chalcones scaffold, often occurs and can improve their modulatory activities, namely, in the production of ROS/RNS during the inflammatory response.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Deok Jeong ◽  
Jaehwi Lee ◽  
Young-Su Yi ◽  
Yanyan Yang ◽  
Kyoung Won Kim ◽  
...  

Electrical stimulation with a weak current has been demonstrated to modulate various cellular and physiological responses, including the differentiation of mesenchymal stem cells and acute or chronic physical pain. Thus, a variety of investigations regarding the physiological role of nano- or microlevel currents at the cellular level are actively proceeding in the field of alternative medicine. In this study, we focused on the anti-inflammatory activity of aluminum-copper patches (ACPs) under macrophage-mediated inflammatory conditions. ACPs generated nanolevel currents ranging from 30 to 55 nA in solution conditions. Interestingly, the nanocurrent-generating aluminum-copper patches (NGACPs) were able to suppress both lipopolysaccharide-(LPS-) and pam3CSK-induced inflammatory responses such as NO and PGE2production in both RAW264.7 cells and peritoneal macrophages at the transcriptional level. Through immunoblotting and immunoprecipitation analyses, we found that p38/AP-1 could be the major inhibitory pathway in the NGACP-mediated anti-inflammatory response. Indeed, inhibition of p38 by SB203580 showed similar inhibitory activity of the production of TNF-αand PGE2and the expression of TNF-αand COX-2 mRNA. These results suggest that ACP-induced nanocurrents alter signal transduction pathways that are involved in the inflammatory response and could therefore be utilized in the treatment of various inflammatory diseases such as arthritis and colitis.


2022 ◽  
Vol 12 ◽  
Author(s):  
Dan He ◽  
Qiangdongzi Mao ◽  
Jialin Jia ◽  
Zhiyu Wang ◽  
Yu Liu ◽  
...  

The efficient removal of apoptotic cells (ACs), a process termed as efferocytosis, is essential for immune homeostasis. While recent work has established an important interplay between efferocytosis and cellular metabolic changing, underlying mechanisms remain poorly known. Here, we discovered that pentose phosphate pathway (PPP) regulates tolerogenic ACs clearance and immune tolerance. ACs decreased levels of PPP-related genes and metabolites in macrophages. AG1, the agonist of PPP, increased the activity of PPP but greatly reduced macrophage phagocytosis of ACs and enhanced the inflammatory response during efferocytosis. miR-323-5p regulated the expression of PPP-related genes and its levels increased during efferocytosis. miR-323-5p inhibitor greatly promoted levels of PPP-related genes, reduced the macrophage phagocytosis of ACs, and increased inflammatory response during efferocytosis, suggesting that miR-323-5p was essential in regulating PPP activity and ACs clearance in macrophages. Correspondingly, the PPP agonist AG1 exacerbated the lupus-like symptoms in the AC-induced systemic lupus erythematosus (SLE) model. Our study reveals that regulating PPP-dependent metabolic reprogramming is critical for tolerogenic ACs phagocytosis and immune tolerance.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Serena Becchi ◽  
Alberto Buson ◽  
Bernard W. Balleine

Abstract Background Changes in dopaminergic neural function can be induced by an acute inflammatory state that, by altering the integrity of the neurovasculature, induces neuronal stress, cell death and causes functional deficits. Effectively blocking these effects of inflammation could, therefore, reduce both neuronal and functional decline. To test this hypothesis, we inhibited vascular adhesion protein 1 (VAP-1), a membrane-bound protein expressed on the endothelial cell surface, that mediates leukocyte extravasation and induces oxidative stress. Method We induced dopaminergic neuronal loss by infusing lipopolysaccharide (LPS) directly into the substantia nigra (SN) in rats and administered the VAP-1 inhibitor, PXS-4681A, daily. Results LPS produced: an acute inflammatory response, the loss of dopaminergic neurons in the SN, reduced the dopaminergic projection to SN target regions, particularly the dorsolateral striatum (DLS), and a deficit in habit learning, a key function of the DLS. In an attempt to protect SN neurons from this inflammatory response we found that VAP-1 inhibition not only reduced neutrophil infiltration in the SN and striatum, but also reduced the associated striatal microglia and astrocyte response. We found VAP-1 inhibition protected dopamine neurons in the SN, their projections to the striatum and promoted the functional recovery of habit learning. Thus, we reversed the loss of habitual actions, a function usually dependent on dopamine release in DLS and sensitive to striatal dysfunction. Conclusions We establish, therefore, that VAP-1 inhibition has an anti-inflammatory profile that may be beneficial in the treatment of dopamine neuron dysfunction caused by an acute inflammatory state in the brain.


2020 ◽  
Author(s):  
Thomas Meul ◽  
Korbinian Berschneider ◽  
Sabine Schmitt ◽  
Christoph H. Mayr ◽  
Laura F. Mattner ◽  
...  

SummaryThe proteasome is the main proteolytic system for targeted protein degradation in the cell. Its function is fine-tuned according to cellular needs. Regulation of proteasome function by mitochondrial metabolism, however, is unknown.Here, we demonstrate that mitochondrial dysfunction reduces the assembly and activity of the 26S proteasome in the absence of oxidative stress. Impaired respiratory complex I function leads to metabolic reprogramming of the Krebs cycle and deficiency in aspartate. Aspartate supplementation activates assembly and activity of 26S proteasomes via transcriptional activation of the proteasome assembly factors p28 and Rpn6. This metabolic adaptation of 26S proteasome function involves sensing of aspartate via the mTORC1 pathway. Metformin treatment of primary human cells similarly reduced assembly and activity of 26S proteasome complexes, which was fully reversible and rescued by supplementation of aspartate or pyruvate. Of note, respiratory dysfunction conferred resistance towards the proteasome inhibitor Bortezomib.Our study uncovers a fundamental novel mechanism of how mitochondrial metabolism adaptively adjusts protein degradation by the proteasome. It thus unravels unexpected consequences of defective mitochondrial metabolism in disease or drug-targeted mitochondrial reprogramming for proteasomal protein degradation in the cell. As metabolic inhibition of proteasome function can be alleviated by treatment with aspartate or pyruvate, our results also have therapeutic implications.


Author(s):  
Zohreh Jadali

Recent literature has highlighted the importance of chronic inflammation in psoriasis pathogenesis. Non-resolving inflammation can trigger progressive tissue damage and inflammatory mediator release which in turn perpetuate the inflammatory cycle. Under normal conditions, inflammatory responses are tightly controlled through several mechanisms that restore normal tissue function and structure. Defects in regulatory mechanisms of the inflammatory response can result in persistent unresolved inflammation and further increases of inflammation. Therefore, this review focuses on defects in regulatory mechanisms of inflammatory responses that lead to uncontrolled chronic inflammation in psoriasis. Databases such as Pubmed Embase, ISI, and Iranian databases including Iranmedex, and SID were researched to identify relevant literature. The results of this review indicate that dysregulation of the inflammatory response may be a likely cause of various immune-mediated inflammatory disorders such as psoriasis. Based on current findings, advances in understanding the cellular and molecular mechanisms involved in inflammation resolution are not only improving our knowledge of the pathogenesis of chronic inflammatory diseases but also supporting the development of new therapeutic strategies.


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