scholarly journals Circadian Rhythm Modulation of Microbes During Health and Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
James Alexander Pearson ◽  
Alexander Christopher Voisey ◽  
Kathrine Boest-Bjerg ◽  
F. Susan Wong ◽  
Li Wen
Keyword(s):  
Circadian Rhythm ◽  
Immune Responses ◽  
Time Of Day ◽  
Gut Bacteria ◽  
Host Immunity ◽  
Specific Therapy ◽  
Therapeutic Success ◽  
Physiological Processes ◽  
Time Specific ◽  
Therapeutic Administration

Circadian rhythms, referring to 24-h daily oscillations in biological and physiological processes, can significantly regulate host immunity to pathogens, as well as commensals, resulting in altered susceptibility to disease development. Furthermore, vaccination responses to microbes have also shown time-of-day-dependent changes in the magnitude of protective immune responses elicited in the host. Thus, understanding host circadian rhythm effects on both gut bacteria and viruses during infection is important to minimize adverse effects on health and identify optimal times for therapeutic administration to maximize therapeutic success. In this review, we summarize the circadian modulations of gut bacteria, viruses and their interactions, both in health and during infection. We also discuss the importance of chronotherapy (i.e., time-specific therapy) as a plausible therapeutic administration strategy to enhance beneficial therapeutic responses.

Matrix Metalloproteinases in Invertebrates

2020 ◽  
Vol 27 (11) ◽  
pp. 1068-1081
Author(s):  
Xi Liu ◽  
Dongwu Liu ◽  
Yangyang Shen ◽  
Mujie Huang ◽  
Lili Gao ◽  
...  
Keyword(s):  
Matrix Metalloproteinases ◽  
Immune Responses ◽  
Theoretical Basis ◽  
Regulatory Mechanism ◽  
Structure And Function ◽  
Catalytic Domains ◽  
Physiological Processes ◽  
Disease Occurrence ◽  
Complex Functions ◽  
And Function

Matrix Metalloproteinases (MMPs) belong to a family of metal-dependent endopeptidases which contain a series of conserved pro-peptide domains and catalytic domains. MMPs have been widely found in plants, animals, and microorganisms. MMPs are involved in regulating numerous physiological processes, pathological processes, and immune responses. In addition, MMPs play a key role in disease occurrence, including tumors, cardiovascular diseases, and other diseases. Compared with invertebrate MMPs, vertebrate MMPs have diverse subtypes and complex functions. Therefore, it is difficult to study the function of MMPs in vertebrates. However, it is relatively easy to study invertebrate MMPs because there are fewer subtypes of MMPs in invertebrates. In the present review, the structure and function of MMPs in invertebrates were summarized, which will provide a theoretical basis for investigating the regulatory mechanism of MMPs in invertebrates.

scholarly journals Infant functional networks are modulated by state of consciousness and circadian rhythm

2021 ◽  
pp. 1-36
Author(s):  
Rachel J. Smith ◽  
Ehsan Alipourjeddi ◽  
Cristal Garner ◽  
Amy L. Maser ◽  
Daniel W. Shrey ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Functional Connectivity ◽  
Principal Component ◽  
Time Of Day ◽  
Clustering Coefficient ◽  
Functional Networks ◽  
Temporal Properties ◽  
Healthy Infants ◽  
Infant Brain ◽  
Eeg Recordings

Abstract Functional connectivity networks are valuable tools for studying development, cognition, and disease in the infant brain. In adults, such networks are modulated by the state of consciousness and the circadian rhythm; however, it is unknown if infant brain networks exhibit similar variation, given the unique temporal properties of infant sleep and circadian patterning. To address this, we analyzed functional connectivity networks calculated from long-term EEG recordings (average duration 20.8 hours) from 19 healthy infants. Networks were subjectspecific, as inter-subject correlations between weighted adjacency matrices were low. However, within individual subjects, both sleep and wake networks were stable over time, with stronger functional connectivity during sleep than wakefulness. Principal component analysis revealed the presence of two dominant networks; visual sleep scoring confirmed that these corresponded to sleep and wakefulness. Lastly, we found that network strength, degree, clustering coefficient, and path length significantly varied with time of day, when measured in either wakefulness or sleep at the group level. Together, these results suggest that modulation of healthy functional networks occurs over ~24 hours and is robust and repeatable. Accounting for such temporal periodicities may improve the physiological interpretation and use of functional connectivity analysis to investigate brain function in health and disease.

An Emerging Role for Chloroplasts in Disease and Defense

2021 ◽  
Vol 59 (1) ◽  
pp. 423-445
Author(s):  
Pradeep Kachroo ◽  
Tessa M. Burch-Smith ◽  
Murray Grant
Keyword(s):  
Immune Responses ◽  
De Novo ◽  
Current Knowledge ◽  
Reactive Oxygen ◽  
Host Immunity ◽  
Retrograde Signaling ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
De Novo Synthesis ◽  
Key Players

Chloroplasts are key players in plant immune signaling, contributing to not only de novo synthesis of defensive phytohormones but also the generation of reactive oxygen and nitrogen species following activation of pattern recognition receptors or resistance (R) proteins. The local hypersensitive response (HR) elicited by R proteins is underpinned by chloroplast-generated reactive oxygen species. HR-induced lipid peroxidation generates important chloroplast-derived signaling lipids essential to the establishment of systemic immunity. As a consequence of this pivotal role in immunity, pathogens deploy effector complements that directly or indirectly target chloroplasts to attenuate chloroplast immunity (CI). Our review summarizes the current knowledge of CI signaling and highlights common pathogen chloroplast targets and virulence strategies. We address emerging insights into chloroplast retrograde signaling in immune responses and gaps in our knowledge, including the importance of understanding chloroplast heterogeneity and chloroplast involvement in intraorganellular interactions in host immunity.

3. When timing goes wrong

2017 ◽  
pp. 24-44
Author(s):  
Russell G. Foster ◽  
Leon Kreitzman
Keyword(s):  
Circadian Rhythm ◽  
Time Of Day ◽  
Circadian System ◽  
Multiple Time ◽  
Sleep Phase ◽  
Circadian Rhythm Sleep Disorders ◽  
Time Zones ◽  
Delayed Sleep Phase Disorder ◽  
Delayed Sleep Phase ◽  
Delayed Sleep

While time of day, interacting with an individual’s chronotype, can have an important impact upon performance and health, severe disruption of the circadian system adds another level of complexity and severity. ‘When timing goes wrong’ considers the effects of flying across multiple time zones, resulting in jet lag, and shift work on human health. Sleep and circadian rhythm disruption is almost always associated with poor health. Four circadian rhythm sleep disorders have been identified: advanced sleep phase disorder, delayed sleep phase disorder, freerunning, and irregular sleep timing. Sleep and circadian rhythm disruption in mental illness and neurodegenerative disease is also discussed.

Identification Methods of G Protein-Coupled Receptors

2011 ◽  
Vol 2 (4) ◽  
pp. 35-52
Author(s):  
Meriem Zekri ◽  
Karima Alem ◽  
Labiba Souici-Meslati
Keyword(s):  
Immune Responses ◽  
G Protein ◽  
Pharmaceutical Research ◽  
G Protein Coupled Receptors ◽  
Machine Learning Algorithms ◽  
Signaling Networks ◽  
Identification Methods ◽  
Physiological Processes ◽  
Cell Signaling Networks ◽  
G Protein Coupled

The G protein-coupled receptors (GPCRs) include one of the largest and most important families of multifunctional proteins known to molecular biology. They play a key role in cell signaling networks that regulate many physiological processes, such as vision, smell, taste, neurotransmission, secretion, immune responses, metabolism, and cell growth. These proteins are thus very important for understanding human physiology and they are involved in several diseases. Therefore, many efforts in pharmaceutical research are to understand their structures and functions, which is not an easy task, because although thousands GPCR sequences are known, many of them remain orphans. To remedy this, many methods have been developed using methods such as statistics, machine learning algorithms, and bio-inspired approaches. In this article, the authors review the approaches used to develop algorithms for classification GPCRs by trying to highlight the strengths and weaknesses of these different approaches and providing a comparison of their performances.

scholarly journals Desflurane anesthesia shifts the circadian rhythm phase depending on the time of day of anesthesia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ryo Imai ◽  
Hiroshi Makino ◽  
Takasumi Katoh ◽  
Tetsuro Kimura ◽  
Tadayoshi Kurita ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Phase Shift ◽  
Clock Genes ◽  
Activity Rhythm ◽  
Time Of Day ◽  
Prevention And Treatment ◽  
The Relationship ◽  
Relative Mrna Expression ◽  
Master Clock ◽  
Rest Activity

Abstract Desflurane is one of the most frequently used inhalational anesthetics in clinical practice. A circadian rhythm phase-shift after general anesthesia with sevoflurane or isoflurane has been reported in mice, but few studies have reported this effect with desflurane. In the present study, we examined the rest/activity rhythm of mice by counting the number of running wheel rotations, and we found that desflurane anesthesia caused a phase shift in the circadian rhythm that was dependent on the time of day of anesthesia. We also found that desflurane anesthesia altered the relative mRNA expression of four major clock genes (Per2, Bmal, Clock, and Cry1) in the suprachiasmatic nucleus (SCN). These results are important for elucidating the effects of desflurane on the SCN, which is the master clock for the mammalian circadian rhythm. Further studies on the relationship between anesthesia and circadian rhythm may lead to the prevention and treatment of postoperative complications related to circadian rhythms.

The crosstalk between gut bacteria and host immunity in intestinal inflammation

2020 ◽  
Author(s):  
Qiuli Yang ◽  
Yuexin Wang ◽  
Anna Jia ◽  
Yufei Wang ◽  
Yujing Bi ◽  
...  
Keyword(s):  
Intestinal Inflammation ◽  
Gut Bacteria ◽  
Host Immunity

scholarly journals Evolutionary and structural analysis of SARS-CoV-2 specific evasion of host immunity

2020 ◽  
Vol 21 (6-8) ◽  
pp. 409-419
Author(s):  
Irfan Hussain ◽  
Nashaiman Pervaiz ◽  
Abbas Khan ◽  
Shoaib Saleem ◽  
Huma Shireen ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nonstructural Protein ◽  
Critical Role ◽  
Clinical Manifestations ◽  
Host Immunity ◽  
Innate Immune ◽  
Host Immune System ◽  
Innate Immune Responses ◽  
In Vivo Models

AbstractThe outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading fast worldwide. There is a pressing need to understand how the virus counteracts host innate immune responses. Deleterious clinical manifestations of coronaviruses have been associated with virus-induced direct dysregulation of innate immune responses occurring via viral macrodomains located within nonstructural protein-3 (Nsp3). However, no substantial information is available concerning the relationship of macrodomains to the unusually high pathogenicity of SARS-CoV-2. Here, we show that structural evolution of macrodomains may impart a critical role to the unique pathogenicity of SARS-CoV-2. Using sequence, structural, and phylogenetic analysis, we identify a specific set of historical substitutions that recapitulate the evolution of the macrodomains that counteract host immune response. These evolutionary substitutions may alter and reposition the secondary structural elements to create new intra-protein contacts and, thereby, may enhance the ability of SARS-CoV-2 to inhibit host immunity. Further, we find that the unusual virulence of this virus is potentially the consequence of Darwinian selection‐driven epistasis in protein evolution. Our findings warrant further characterization of macrodomain-specific evolutionary substitutions in in vitro and in vivo models to determine their inhibitory effects on the host immune system.

scholarly journals Activation of c-Jun N-Terminal Kinase, a Potential Therapeutic Target in Autoimmune Arthritis

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2466
Author(s):  
Benjamin Lai ◽  
Chien-Hsiang Wu ◽  
Jenn-Haung Lai
Keyword(s):  
Immune Responses ◽  
Proinflammatory Cytokines ◽  
Therapeutic Target ◽  
Signaling Molecules ◽  
Autoimmune Disorders ◽  
Autoimmune Arthritis ◽  
Potential Therapeutic Target ◽  
Downstream Signaling ◽  
Physiological Processes ◽  
Complex Manner

The c-Jun-N-terminal kinase (JNK) is a critical mediator involved in various physiological processes, such as immune responses, and the pathogenesis of various diseases, including autoimmune disorders. JNK is one of the crucial downstream signaling molecules of various immune triggers, mainly proinflammatory cytokines, in autoimmune arthritic conditions, mainly including rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. The activation of JNK is regulated in a complex manner by upstream kinases and phosphatases. Noticeably, different subtypes of JNKs behave differentially in immune responses. Furthermore, aside from biologics targeting proinflammatory cytokines, small-molecule inhibitors targeting signaling molecules such as Janus kinases can act as very powerful therapeutics in autoimmune arthritis patients unresponsiveness to conventional synthetic antirheumatic drugs. Nevertheless, despite these encouraging therapies, a population of patients with an inadequate therapeutic response to all currently available medications still remains. These findings identify the critical signaling molecule JNK as an attractive target for investigation of the immunopathogenesis of autoimmune disorders and for consideration as a potential therapeutic target for patients with autoimmune arthritis to achieve better disease control. This review provides a useful overview of the roles of JNK, how JNK is regulated in immunopathogenic responses, and the potential of therapeutically targeting JNK in patients with autoimmune arthritis.

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