scholarly journals Mitochondrial DNA as an inflammatory mediator in cardiovascular diseases

2018 ◽  
Vol 475 (5) ◽  
pp. 839-852 ◽  
Author(s):  
Hiroyuki Nakayama ◽  
Kinya Otsu

Mitochondria play a central role in multiple cellular functions, including energy production, calcium homeostasis, and cell death. Currently, growing evidence indicates the vital roles of mitochondria in triggering and maintaining inflammation. Chronic inflammation without microbial infection — termed sterile inflammation — is strongly involved in the development of heart failure. Sterile inflammation is triggered by the activation of pattern recognition receptors (PRRs) that sense endogenous ligands called damage-associated molecular patterns (DAMPs). Mitochondria release multiple DAMPs including mitochondrial DNA, peptides, and lipids, which induce inflammation via the stimulation of multiple PRRs. Among the mitochondrial DAMPs, mitochondrial DNA (mtDNA) is currently highlighted as the DAMP that mediates the activation of multiple PRRs, including Toll-like receptor 9, Nod-like receptors, and cyclic GMP–AMP synthetase/stimulator of interferon gene pathways. These PRR signalling pathways, in turn, lead to the activation of nuclear factor-κB and interferon regulatory factor, which enhances the transcriptional activity of inflammatory cytokines and interferons, and induces the recruitment of inflammatory cells. As the heart is an organ comprising abundant mitochondria for its ATP consumption (needed to maintain constant cyclic contraction and relaxation), the generation of massive amounts of mitochondrial radical oxygen species and mitochondrial DAMPs are predicted to occur and promote cardiac inflammation. Here, we will focus on the role of mtDNA in cardiac inflammation and review the mechanism and pathological significance of mtDNA-induced inflammatory responses in cardiac diseases.

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 903
Author(s):  
Eun-Ji Lee ◽  
Hyun-Jeong Kim ◽  
Min Sik Choi ◽  
Ji-Eun Chang

Inflammation is an adaptive response to tissue injury, which is a critical process in order to restore tissue functionality and homeostasis. The association between inflammation and cancer has been a topic of interest for many years, not only inflammatory cells themselves but also the chemokines and cytokines they produce, which affect cancer development. Autophagy is an intracellular self-degradative process providing elimination of damaged or dysfunctional organelles under stressful conditions such as nutrient deficiency, hypoxia, or chemotherapy. Interestingly, the signaling pathways that are involved in cancer-associated inflammation may regulate autophagy as well. These are 1) the toll-like receptor (TLR) signaling cascade, 2) the reactive oxygen species (ROS) signaling pathway, 3) the inflammatory cytokine signaling pathway, and 4) the IκB kinase (IKK)/Nuclear factor-κB (NF-κB) signaling axis. Moreover, the studies on the context-specific functions of autophagy during inflammatory responses in cancer will be discussed here. On that basis, we focus on autophagy inhibitors and activators regulating inflammatory process in cancer as useful candidates for enhancing anticancer effects. This review summarizes how the autophagic process regulates these key inflammatory processes and vice versa in various cancers.


2020 ◽  
Vol 26 ◽  
Author(s):  
Alexander N. Orekhov ◽  
Elena V. Gerasimova ◽  
Vasily N. Sukhorukov ◽  
Anastasia V. Poznyak ◽  
Nikita G. Nikiforov

Background: The elucidation of mechanisms implicated in the chronification of inflammation is able to shed the light on the pathogenesis of disorders that are responsible for the majority of the incidence of disease and deaths, and also causes of ageing. Atherosclerosis is an example of the most significant inflammatory pathology. The inflammatory response of innate immunity is implicated in the development of atherosclerosis arising locally or focally. Modified low-density lipoprotein (LDL) was regarded as the trigger for this response. No atherosclerotic changes in the arterial wall occur due to the quick decrease in inflammation rate. Nonetheless, the atherosclerotic lesion formation can be a result of the chronification of local inflammation, which, in turn, is caused by alteration of the response of innate immunity. Objective: In this review, we discussed potential mechanisms of the altered response of the immunity in atherosclerosis with a particular emphasis on mitochondrial dysfunctions. Conclusion: A few mitochondrial dysfunctions can be caused by the mitochondrial DNA (mtDNA) mutations. Moreover, mtDNA mutations were found to affect the development of defective mitophagy. Modern investigations have demonstrated the controlling mitophagy function in the response of the immune system. Therefore, we hypothesized that impaired mitophagy, as a consequence of mutations in mtDNA, can raise a disturbed innate immunity response resulting in the chronification of inflammation in atherosclerosis.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Chen Zhang ◽  
Xiao Shi ◽  
Zhongping Su ◽  
Chao Hu ◽  
Xianmin Mu ◽  
...  

Abstract Background Acetaminophen (APAP) overdose causes hepatotoxicity and even acute liver failure. Recent studies indicate that sterile inflammation and innate immune cells may play important roles in damage-induced hepatocytes regeneration and liver repair. The scavenger receptor CD36 has its crucial functions in sterile inflammation. However, the roles of CD36 in APAP induced acute liver injury remain unclear and warrant further investigation. Methods WT C57BL/6 J and CD36−/− mice were intraperitoneally injected with APAP (300 mg/kg) after fasting for 16 h. Liver injury was evaluated by serum alanine aminotransferase (ALT) level and liver tissue hematoxylin and eosin (H&E) staining. Liver inflammatory factor expression was determined by real-time polymerase chain reaction (PCR). The protein adducts forming from the metabolite of APAP and the metabolism enzyme cytochrome P450 2E1 (CYP2E1) levels were measured by Western blot. Liver infiltrating macrophages and neutrophils were characterized by flow cytometry. RNA sequencing and Western blot were used to evaluate the effect of damage-associated molecular patterns (DAMP) molecule high mobility group B1 (HMGB1) on WT and CD36−/− macrophages. Moreover, PP2, a Src kinase inhibitor, blocking CD36 signaling, was applied in APAP model. Results The expression of CD36 was increased in the liver of mice after APAP treatment. Compared with WT mice, APAP treated CD36−/− mice show less liver injury. There was no significant difference in APAP protein adducts and CYP2E1 expression between these two strains. However, reduced pro-inflammatory factor mRNA expression and serum IL-1β level were observed in APAP treated CD36−/− mice as well as infiltrating macrophages and neutrophils. Moreover, CD36 deficiency impaired the activation of c-Jun N-terminal kinase (JNK) caused by APAP. Interestingly, the lack of CD36 reduced the activation of extracellular regulated protein kinases (Erk) and v-akt murine thymoma viral oncogene homolog (Akt) induced by HMGB1. RNA transcription sequencing data indicated that HMGB1 has a different effect on WT and CD36−/− macrophages. Furthermore, treatment with PP2 attenuated APAP induced mouse liver injury. Conclusion Our data demonstrated that CD36 deficiency ameliorated APAP-induced acute liver injury and inflammatory responses by decreasing JNK activation. CD36 might serve as a new target to reduce acute liver injury.


2021 ◽  
Vol 22 (8) ◽  
pp. 3970
Author(s):  
Md Razib Hossain ◽  
Tuba M. Ansary ◽  
Mayumi Komine ◽  
Mamitaro Ohtsuki

The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. This review covers the mechanistic aspects of skin pigmentation caused by inflammation.


2018 ◽  
Vol 19 (10) ◽  
pp. 3104 ◽  
Author(s):  
Sabine Mihm

Inflammatory liver diseases in the absence of pathogens such as intoxication by xenobiotics, cholestatic liver injury, hepatic ischemia-reperfusion injury (I/R), non-alcoholic steatohepatitis (NASH), or alcoholic liver disease (ALD) remain threatening conditions demanding specific therapeutic options. Caused by various different noxae, all these conditions have been recognized to be triggered by danger- or death-associated molecular patterns (DAMPs), discompartmentalized self-structures released by dying cells. These endogenous, ectopic molecules comprise proteins, nucleic acids, adenosine triphosphate (ATP), or mitochondrial compounds, among others. This review resumes the respective modes of their release—passively by necrotic hepatocytes or actively by viable or apoptotic parenchymal cells—and their particular roles in sterile liver pathology. It addresses their sensors and the initial inflammatory responses they provoke. It further addresses a resulting second wave of parenchymal death that might be of different mode, boosting the release of additional, second-line DAMPs. Thus, triggering a more complex and pronounced response. Initial and secondary inflammatory responses comprise the activation of Kupffer cells (KCs), the attraction and activation of monocytes and neutrophil granulocytes, and the induction of type I interferons (IFNs) and their effectors. A thorough understanding of pathophysiology is a prerequisite for identifying rational therapeutic targets.


2005 ◽  
Vol 48 (spe2) ◽  
pp. 145-152 ◽  
Author(s):  
David Wareham ◽  
J. Michael ◽  
Satya Das

Nuclear medicine is a powerful diagnostic technique able to detect inflammatory foci in human disease. A wide range of agents have been evaluated for their ability to distinguish lesions due to microbial infection from those due to sterile inflammation. Advances continue to be made on the use of radiolabelled antibiotics which as well as being highly specific in the diagnosis of infection may be useful in monitoring the treatment and course of disease. Here we provide an update on in-vitro and clinical studies with a number of established and novel radiopharmaceuticals


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lili Wang ◽  
Qianhui Zhang ◽  
Kexin Yuan ◽  
Jing Yuan

The incidence rate of cardiovascular disease (CVD) has been increasing year by year and has become the main cause for the increase of mortality. Mitochondrial DNA (mtDNA) plays a crucial role in the pathogenesis of CVD, especially in heart failure and ischemic heart diseases. With the deepening of research, more and more evidence showed that mtDNA is related to the occurrence and development of CVD. Current studies mainly focus on how mtDNA copy number, an indirect biomarker of mitochondrial function, contributes to CVD and its underlying mechanisms including mtDNA autophagy, the effect of mtDNA on cardiac inflammation, and related metabolic functions. However, no relevant studies have been conducted yet. In this paper, we combed the current research status of the mechanism related to the influence of mtDNA on the occurrence, development, and prognosis of CVD, so as to find whether these mechanisms have something in common, or is there a correlation between each mechanism for the development of CVD?


2019 ◽  
Vol 47 (5) ◽  
pp. 1383-1392 ◽  
Author(s):  
Ying-Chi Chao ◽  
Nicoletta C. Surdo ◽  
Sergio Pantano ◽  
Manuela Zaccolo

Abstract 3′-5′-cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that modulates multiple cellular functions. It is now well established that cAMP can mediate a plethora of functional effects via a complex system of local regulatory mechanisms that result in compartmentalized signalling. The use of fluorescent probes to monitor cAMP in intact, living cells have been instrumental in furthering our appreciation of this ancestral and ubiquitous pathway and unexpected details of the nano-architecture of the cAMP signalling network are starting to emerge. Recent evidence shows that sympathetic control of cardiac contraction and relaxation is achieved via generation of multiple, distinct pools of cAMP that lead to differential phosphorylation of target proteins localized only tens of nanometres apart. The specific local control at these nanodomains is enabled by a distinct signalosome where effectors, targets, and regulators of the cAMP signal are clustered. In this review, we focus on recent advances using targeted fluorescent reporters for cAMP and how they have contributed to our current understanding of nanodomain cAMP signalling in the heart. We briefly discuss how this information can be exploited to design novel therapies and we highlight some of the questions that remain unanswered.


2018 ◽  
Vol 61 (2) ◽  
pp. F1-F6 ◽  
Author(s):  
Kira Meyerovich ◽  
Fernanda Ortis ◽  
Alessandra K Cardozo

The prevalence of diabetes has reached 8.8% in worldwide population and is predicted to increase up to 10.4% by 2040. Thus, there is an urgent need for the development of means to treat or prevent this major disease. Due to its role in inflammatory responses, several studies demonstrated the importance of the transcription factor nuclear factor-κB (NF-κB) in both type 1 diabetes (T1D) and type 2 diabetes (T2D). The two major NF-κB pathways are the canonical and the non-canonical. The later pathway is activated by the NF-κB-inducing kinase (NIK) that triggers p100 processing into p52, which forms with RelB its main dimer. Cytokines mediating the activation of this pathway are present in the serum of T1D and T2D patients. Conversely, limited information is available regarding the role of the alternative pathway on diabetes development and β-cell fate. In the present review, we will briefly describe the involvement of NF-κB on diabetes pathology and discuss new studies indicating an important role for the non-canonical NF-κB activation in β-cell function and survival. The non-canonical NF-κB pathway is emerging as a novel potential target for the development of therapeutic strategies to treat or prevent diabetes.


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