Mitochondria and Inflammatory Bowel Diseases: Toward a Stratified Therapeutic Intervention

2021 ◽  
Vol 84 (1) ◽  
Author(s):  
Gwo-tzer Ho ◽  
Arianne L. Theiss

Mitochondria serve numerous critical cellular functions, rapidly responding to extracellular stimuli and cellular demands while dynamically communicating with other organelles. Mitochondrial function in the gastrointestinal epithelium plays a critical role in maintaining intestinal health. Emerging studies implicate the involvement of mitochondrial dysfunction in inflammatory bowel disease (IBD). This review presents mitochondrial metabolism, function, and quality control that converge in intestinal epithelial stemness, differentiation programs, barrier integrity, and innate immunity to influence intestinal inflammation. Intestinal and disease characteristics that set the stage for mitochondrial dysfunction being a key factor in IBD, and in turn, pathogenic mitochondrial mechanisms influencing and potentiating the development of IBD, are discussed. These findings establish the basis for potential mitochondrial-targeted interventions for IBD therapy. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

2021 ◽  
Vol 22 (5) ◽  
pp. 2645
Author(s):  
Dinh Nam Tran ◽  
Seon Myeong Go ◽  
Seon-Mi Park ◽  
Eui-Man Jung ◽  
Eui-Bae Jeung

Inflammatory bowel diseases (IBDs) comprises a range of chronic inflammatory conditions of the intestinal tract. The incidence and prevalence of IBDs are increasing worldwide, but the precise etiology of these diseases is not completely understood. Calcium signaling plays a regulatory role in cellular proliferation. Nckx3, a potassium-dependent Na+/Ca2+ exchanger, is not only expressed in the brain but also in the aortic, uterine, and intestinal tissues, which contain abundant smooth muscle cells. This study investigated the role of Nckx3 in intestinal inflammation. Microarray analyses revealed the upregulation of the innate immune response-associated genes in the duodenum of Nckx3 knockout (KO) mice. The Nckx3 KO mice also showed an increase in IBD- and tumorigenesis-related genes. Using dextran sodium sulfate (DSS)-induced experimental colitis mice models, the Nckx3 KO mice showed severe colitis. Furthermore, the pathways involving p53 and NF-κB signaling were significantly upregulated by the absence of Nckx3. Overall, Nckx3 plays a critical role in the innate immune and immune response and may be central to the pathogenesis of IBD.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Tiago Nunes ◽  
Claudio Bernardazzi ◽  
Heitor S. de Souza

Cell death mechanisms have been associated with the development of inflammatory bowel diseases in humans and mice. Recent studies suggested that a complex crosstalk between autophagy/apoptosis, microbe sensing, and enhanced endoplasmic reticulum stress in the epithelium could play a critical role in these diseases. In addition, necroptosis, a relatively novel programmed necrosis-like pathway associated with TNF receptor activation, seems to be also present in the pathogenesis of Crohn’s disease and in specific animal models for intestinal inflammation. This review attempts to cover new data related to cell death mechanisms and inflammatory bowel diseases.


Author(s):  
Nuno-Valério Silva ◽  
Diogo Carregosa ◽  
Catarina Gonçalves ◽  
Otília V. Vieira ◽  
Cláudia Nunes dos Santos ◽  
...  

Inflammatory bowel diseases (IBD) with chronic infiltration of immune cells in the gastrointestinal tract are common and largely incurable. The therapeutic targeting of IBD has been hampered by the complex causality of the disease, with environmental insults like cholesterol-enriched Western diets playing a critical role. To address this drug development challenge, we report an easy-to-handle dietary cholesterol-based in vivo assay that allows the screening of immune-modulatory therapeutics in transgenic zebrafish models. An improvement in the feeding strategy with high cholesterol diet (HCD) selectively induces a robust and consistent infiltration of myeloid cells in larvae intestines that is highly suitable for compound discovery efforts. Using transgenics with fluorescent reporter expression in neutrophils, we take advantage of the unique zebrafish larvae clarity to monitor an acute inflammatory response in a whole organism context with a fully functional innate immune system. The use of semi-automated image acquisition and processing combined with quantitative image analysis allows categorizing anti- or pro-inflammatory compounds based on a leukocytic inflammation index. Our HCD gut inflammation (HCD-GI) assay is simple, cost- and time-effective as well as highly physiological which makes it unique when compared to chemical-based zebrafish models of IBD. Besides, diet is a highly controlled, selective and targeted trigger of intestinal inflammation that avoids extra-intestinal outcomes and reduces the chances of chemical-induced toxicity during screenings. We show the validity of this assay for a screening platform by testing two dietary phenolic acids, namely gallic acid (GA; 3,4,5-trihydroxybenzoic acid) and ferulic acid (FA; 4-hydroxy-3-methoxycinnamic acid), with well described anti-inflammatory actions in animal models of IBD. Analysis of common IBD therapeutics (Prednisolone and Mesalamine) proved the fidelity of our IBD-like intestinal inflammation model. In conclusion, the HCD-GI assay can facilitate and accelerate drug discovery efforts on IBD, by identification of novel lead molecules with immune modulatory action on intestinal neutrophilic inflammation. This will serve as a jumping-off point for more profound analyses of drug mechanisms and pathways involved in early IBD immune responses.


Author(s):  
Huimin Chen ◽  
Xiaohan Wu ◽  
Chunjin Xu ◽  
Jian Lin ◽  
Zhanju Liu

Abstract Neutrophils are considered as complex innate immune cells and play a critical role in maintaining intestinal mucosal homeostasis. They exert robust pro-inflammatory effects and recruit other immune cells in the acute phase of pathogen infection and intestinal inflammation, but paradoxically, they also limit exogenous microbial invasion and facilitate mucosal restoration. Hyperactivation or dysfunction of neutrophils results in abnormal immune responses, leading to multiple autoimmune and inflammatory diseases including systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel diseases (IBD). As a refractory intestinal inflammatory disease, the pathogenesis and progression of IBD are associated with complicated immune response processes in which neutrophils are profoundly involved. However, the consensus on potential roles of neutrophils in modulating pathogenic and repair processes of IBD remains not fully understood. Accumulated infiltrating neutrophils cross the epithelial barrier and contribute to microbial dysbiosis, aggravated intestinal architectural damage, compromised resolution of intestinal inflammation and increased risk of thrombosis during IBD. Paradoxically, activated neutrophils are also associated with effective elimination of invaded microbiota, promoted angiogenesis and tissue restoration of gut mucosa in IBD. Here, we discuss the beneficial and detrimental roles of neutrophils in the onset and resolution of intestinal mucosal inflammation and provide a precise overview of neutrophil functions in the pathogenesis of IBD.


2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Yue Shan ◽  
Mirae Lee ◽  
Eugene B. Chang

Inflammatory bowel diseases (IBD) arise from a convergence of genetic risk, environmental factors, and gut microbiota, where each is necessary but not sufficient to cause disease. Emerging evidence supports a bidirectional relationship between disease progression and changes in microbiota membership and function. Thus, the study of the gut microbiome and host–microbe interactions should provide critical insights into disease pathogenesis as well as leads for developing microbiome-based diagnostics and interventions for IBD. In this article, we review the most recent advances in understanding the relationship between the gut microbiota and IBD and highlight the importance of going beyond establishing description and association to gain mechanistic insights into causes and consequences of IBD. The review aims to contextualize recent findings to form conceptional frameworks for understanding the etiopathogenesis of IBD and for the future development of microbiome-based diagnostics and interventions. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Masaki Isoda

As a frontal node in the primate social brain, the medial prefrontal cortex (MPFC) plays a critical role in coordinating one's own behavior with respect to that of others. Current literature demonstrates that single neurons in the MPFC encode behavior-related variables such as intentions, actions, and rewards, specifically for self and other, and that the MPFC comes into play when reflecting upon oneself and others. The social moderator account of MPFC function can explain maladaptive social cognition in people with autism spectrum disorder, which tips the balance in favor of self-centered perspectives rather than taking into consideration the perspective of others. Several strands of evidence suggest a hypothesis that the MPFC represents different other mental models, depending on the context at hand, to better predict others’ emotions and behaviors. This hypothesis also accounts for aberrant MPFC activity in autistic individuals while they are mentalizing others. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 90 (1) ◽  
Author(s):  
Yi Wen ◽  
Volker M. Vogt ◽  
Gerald W. Feigenson

Located at the inner leaflet of the plasma membrane, phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] comprises only 1–2 mol% of total PM lipids. With its synthesis and turnover both spatially and temporally regulated, PI(4,5)P2 recruits and interacts with hundreds of cellular proteins to support a broad spectrum of cellular functions. Several factors contribute to the versatile and dynamic distribution of PI(4,5)P2 in membranes. Physiological multivalent cations such as Ca2+ and Mg2+ can bridge between PI(4,5)P2 headgroups, forming nanoscopic PI(4,5)P2–cation clusters. The distinct lipid environment surrounding PI(4,5)P2 affects the degree of PI(4,5)P2 clustering. In addition, diverse cellular proteins interacting with PI(4,5)P2 can further regulate PI(4,5)P2 lateral distribution and accessibility. This review summarizes the current understanding of PI(4,5)P2 behavior in both cells and model membranes, with emphasis on both multivalent cation– and protein-induced PI(4,5)P2 clustering. Understanding the nature of spatially separated pools of PI(4,5)P2 is fundamental to cell biology. Expected final online publication date for the Annual Review of Biochemistry, Volume 90 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2019 ◽  
Vol 5 ◽  
pp. 18-30 ◽  
Author(s):  
Jonathan C. Valdez ◽  
Bradley W. Bolling

Chronic intestinal inflammation, occurring in inflammatory bowel diseases (IBD), is associated with compromised intestinal barrier function. Inflammatory cytokines disrupt tight junctions and increase paracellular permeability of luminal antigens. Thus, chronic intestinal barrier dysfunction hinders the resolution of inflammation. Dietary approaches may help mitigate intestinal barrier dysfunction and chronic inflammation. A growing body of work in rodent models of colitis has demonstrated that berry consumption inhibits chronic intestinal inflammation. Berries are a rich dietary source of polyphenolic compounds, particularly anthocyanins. However, berry anthocyanins have limited bioavailability and are extensively metabolized by the gut microbiota and host tissue. This review summarizes the literature regarding the beneficial functions of anthocyanin-rich berries in treating and preventing IBD. Here, we will establish the role of barrier function in the pathogenesis of IBD and how dietary anthocyanins and their known microbial catabolites modulate intestinal barrier function.


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