scholarly journals Constitutive Androstane Receptor: A Peripheral and a Neurovascular Stress or Environmental Sensor

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2426
Author(s):  
Fabiana Oliviero ◽  
Céline Lukowicz ◽  
Badreddine Boussadia ◽  
Isabel Forner-Piquer ◽  
Jean-Marc Pascussi ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Physiological Stress ◽  
Neurovascular Unit ◽  
Constitutive Androstane Receptor ◽  
Functional Expression ◽  
Brain Diseases ◽  
Clear Understanding ◽  
Physiological Processes ◽  
Entry Points ◽  
Lipid Sensing

Xenobiotic nuclear receptors (NR) are intracellular players involved in an increasing number of physiological processes. Examined and characterized in peripheral organs where they govern metabolic, transport and detoxification mechanisms, accumulating data suggest a functional expression of specific NR at the neurovascular unit (NVU). Here, we focus on the Constitutive Androstane Receptor (CAR), expressed in detoxifying organs such as the liver, intestines and kidneys. By direct and indirect activation, CAR is implicated in hepatic detoxification of xenobiotics, environmental contaminants, and endogenous molecules (bilirubin, bile acids). Importantly, CAR participates in physiological stress adaptation responses, hormonal and energy homeostasis due to glucose and lipid sensing. We next analyze the emerging evidence supporting a role of CAR in NVU cells including the blood–brain barrier (BBB), a key vascular interface regulating communications between the brain and the periphery. We address the emerging concept of how CAR may regulate specific P450 cytochromes at the NVU and the associated relevance to brain diseases. A clear understanding of how CAR engages during pathological conditions could enable new mechanistic, and perhaps pharmacological, entry-points within a peripheral–brain axis.

scholarly journals Noncanonical Constitutive Androstane Receptor Signaling in Gene Regulation

2020 ◽  
Vol 21 (18) ◽  
pp. 6735
Author(s):  
Yuliya A. Pustylnyak ◽  
Lyudmila F. Gulyaeva ◽  
Vladimir O. Pustylnyak
Keyword(s):  
Cell Biology ◽  
Energy Homeostasis ◽  
Hormone Receptors ◽  
Target Genes ◽  
Constitutive Androstane Receptor ◽  
Steroid Hormone Receptors ◽  
Metabolizing Enzymes ◽  
Physiological Processes ◽  
Genes Encoding

The constitutive androstane receptor (CAR, NR1I3) is extremely important for the regulation of many physiological processes, especially xenobiotic (drug) metabolism and transporters. CAR differs from steroid hormone receptors in that it can be activated using structurally unrelated chemicals, both through direct ligand-binding and ligand-independent (indirect) mechanisms. By binding to specific responsive elements on DNA, CAR increases the expression of its target genes encoding drug-metabolizing enzymes and transporters. Therefore, CAR is mainly characterized as a ligand-dependent or ligand-independent transcription factor, and the induction of gene expression is considered the canonical mode of CAR action. Consistent with its central role in xenobiotic metabolism, CAR signaling includes a collection of mechanisms that are employed alongside the core transcriptional machinery of the receptor. These so-called noncanonical CAR pathways allow the receptor to coordinate the regulation of many aspects of cell biology. In this mini-review, we review noncanonical CAR signaling, paying special attention to the role of CAR in energy homeostasis and cell proliferation.

scholarly journals Targeting microRNAs to Regulate the Integrity of the Blood–Brain Barrier

2021 ◽  
Vol 9 ◽  
Author(s):  
Juntao Wang ◽  
Fang Xu ◽  
Xiaoming Zhu ◽  
Xianghua Li ◽  
Yankun Li ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Neurovascular Unit ◽  
Cerebrovascular Diseases ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Brain Diseases ◽  
Blood Brain ◽  
Recent Developments ◽  
Important Regulator

The blood–brain barrier (BBB) is a highly specialized neurovascular unit that protects the brain from potentially harmful substances. In addition, the BBB also engages in the exchange of essential nutrients between the vasculature and brain parenchyma, which is critical for brain homeostasis. Brain diseases, including neurological disorders and cerebrovascular diseases, are often associated with disrupted BBB integrity, evidenced by increased permeability. Therefore, defining the mechanisms underlying the regulation of BBB integrity is crucial for the development of novel therapeutics targeting brain diseases. MicroRNAs (miRNA), a type of small non-coding RNAs, are emerging as an important regulator of BBB integrity. Here we review recent developments related to the role of miRNAs in regulating BBB integrity.

A review of bioeffects induced by focused ultrasound combined with microbubbles on the neurovascular unit

2021 ◽  
pp. 0271678X2110461
Author(s):  
Si Chen ◽  
Arash Nazeri ◽  
Hongchae Baek ◽  
Dezhuang Ye ◽  
Yaoheng Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Focused Ultrasound ◽  
Neurovascular Unit ◽  
Cell Types ◽  
Current Treatment ◽  
Clinical Applications ◽  
Brain Diseases ◽  
Great Promise ◽  
Cellular Effects ◽  
Cell Type Specific

Focused ultrasound combined with circulating microbubbles (FUS+MB) can transiently enhance blood-brain barrier (BBB) permeability at targeted brain locations. Its great promise in improving drug delivery to the brain is reflected by a rapidly growing number of clinical trials using FUS+MB to treat various brain diseases. As the clinical applications of FUS+MB continue to expand, it is critical to have a better understanding of the molecular and cellular effects induced by FUS+MB to enhance the efficacy of current treatment and enable the discovery of new therapeutic strategies. Existing studies primarily focus on FUS+MB-induced effects on brain endothelial cells, the major cellular component of BBB. However, bioeffects induced by FUS+MB expand beyond the BBB to cells surrounding blood vessels, including astrocytes, microglia, and neurons. Together these cell types comprise the neurovascular unit (NVU). In this review, we examine cell-type-specific bioeffects of FUS+MB on different NVU components, including enhanced permeability in endothelial cells, activation of astrocytes and microglia, as well as increased intraneuron protein metabolism and neuronal activity. Finally, we discuss knowledge gaps that must be addressed to further advance clinical applications of FUS+MB.

scholarly journals Dimorphic metabolic and endocrine disorders in mice lacking the constitutive androstane receptor

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Céline Lukowicz ◽  
Sandrine Ellero-Simatos ◽  
Marion Régnier ◽  
Fabiana Oliviero ◽  
Frédéric Lasserre ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Hepatic Steatosis ◽  
Energy Homeostasis ◽  
Metabolic Diseases ◽  
Constitutive Androstane Receptor ◽  
Developed Countries ◽  
Health Concern ◽  
Endocrine Disorders ◽  
Male Mice ◽  
Treatment Of Obesity

AbstractMetabolic diseases such as obesity, type II diabetes and hepatic steatosis are a public health concern in developed countries. The metabolic risk is gender‐dependent. The constitutive androstane receptor (CAR), which is at the crossroads between energy metabolism and endocrinology, has recently emerged as a promising therapeutic agent for the treatment of obesity and type 2 diabetes. In this study we sought to determine its role in the dimorphic regulation of energy homeostasis. We tracked male and female WT and CAR deficient (CAR−/−) mice for over a year. During aging, CAR−/− male mice developed hypercortisism, obesity, glucose intolerance, insulin insensitivity, dyslipidemia and hepatic steatosis. Remarkably, the latter modifications were absent, or minor, in female CAR−/− mice. When ovariectomized, CAR−/− female mice developed identical patterns of metabolic disorders as observed in male mice. These results highlight the importance of steroid hormones in the regulation of energy metabolism by CAR. They unveil a sexually dimorphic role of CAR in the maintenance of endocrine and metabolic homeostasis underscoring the importance of considering sex in treatment of metabolic diseases.

scholarly journals Neurological Diseases in Relation to the Blood–Brain Barrier

2012 ◽  
Vol 32 (7) ◽  
pp. 1139-1151 ◽  
Author(s):  
Gary A Rosenberg
Keyword(s):  
Free Radicals ◽  
Blood Brain Barrier ◽  
Neurological Diseases ◽  
Neurovascular Unit ◽  
Brain Barrier ◽  
Cellular Damage ◽  
Brain Diseases ◽  
Acute Injury ◽  
Blood Brain ◽  
The Brain

Disruption of the blood–brain barrier (BBB) has an important part in cellular damage in neurological diseases, including acute and chronic cerebral ischemia, brain trauma, multiple sclerosis, brain tumors, and brain infections. The neurovascular unit (NVU) forms the interface between the blood and brain tissues. During an injury, the cascade of molecular events ends in the final common pathway for BBB disruption by free radicals and proteases, which attack membranes and degrade the tight junction proteins in endothelial cells. Free radicals of oxygen and nitrogen and the proteases, matrix metalloproteinases and cyclooxgyenases, are important in the early and delayed BBB disruption as the neuroinflammatory response progresses. Opening of the BBB occurs in neurodegenerative diseases and contributes to the cognitive changes. In addition to the importance of the NVU in acute injury, angiogenesis contributes to the recovery process. The challenges to treatment of the brain diseases involve not only facilitating drug entry into the brain, but also understanding the timing of the molecular cascades to block the early NVU injury without interfering with recovery. This review will describe the molecular and cellular events associated with NVU disruption and potential strategies directed toward restoring its integrity.

scholarly journals Glycerolipid Metabolism and Signaling in Health and Disease

2008 ◽  
Vol 29 (6) ◽  
pp. 647-676 ◽  
Author(s):  
Marc Prentki ◽  
S. R. Murthy Madiraju
Keyword(s):  
Energy Homeostasis ◽  
Neutral Lipids ◽  
Biological Processes ◽  
Cellular Functions ◽  
Appetite Control ◽  
Futile Cycle ◽  
Therapeutic Implications ◽  
Product Cycles ◽  
Continuous Formation ◽  
Physiological Processes

Abstract Maintenance of body temperature is achieved partly by modulating lipolysis by a network of complex regulatory mechanisms. Lipolysis is an integral part of the glycerolipid/free fatty acid (GL/FFA) cycle, which is the focus of this review, and we discuss the significance of this pathway in the regulation of many physiological processes besides thermogenesis. GL/FFA cycle is referred to as a “futile” cycle because it involves continuous formation and hydrolysis of GL with the release of heat, at the expense of ATP. However, we present evidence underscoring the “vital” cellular signaling roles of the GL/FFA cycle for many biological processes. Probably because of its importance in many cellular functions, GL/FFA cycling is under stringent control and is organized as several composite short substrate/product cycles where forward and backward reactions are catalyzed by separate enzymes. We believe that the renaissance of the GL/FFA cycle is timely, considering the emerging view that many of the neutral lipids are in fact key signaling molecules whose production is closely linked to GL/FFA cycling processes. The evidence supporting the view that alterations in GL/FFA cycling are involved in the pathogenesis of “fatal” conditions such as obesity, type 2 diabetes, and cancer is discussed. We also review the different enzymatic and transport steps that encompass the GL/FFA cycle leading to the generation of several metabolic signals possibly implicated in the regulation of biological processes ranging from energy homeostasis, insulin secretion and appetite control to aging and longevity. Finally, we present a perspective of the possible therapeutic implications of targeting this cycling.

scholarly journals Mitophagy: Molecular Mechanisms, New Concepts on Parkin Activation and the Emerging Role of AMPK/ULK1 Axis

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 30
Author(s):  
Roberto Iorio ◽  
Giuseppe Celenza ◽  
Sabrina Petricca
Keyword(s):  
Energy Homeostasis ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Mitochondrial Fission ◽  
E3 Ligases ◽  
Physiological Processes ◽  
New Concepts ◽  
Development And Differentiation ◽  
Amp Activated Protein Kinase ◽  
Spatial Specificity

Mitochondria are multifunctional subcellular organelles essential for cellular energy homeostasis and apoptotic cell death. It is, therefore, crucial to maintain mitochondrial fitness. Mitophagy, the selective removal of dysfunctional mitochondria by autophagy, is critical for regulating mitochondrial quality control in many physiological processes, including cell development and differentiation. On the other hand, both impaired and excessive mitophagy are involved in the pathogenesis of different ageing-associated diseases such as neurodegeneration, cancer, myocardial injury, liver disease, sarcopenia and diabetes. The best-characterized mitophagy pathway is the PTEN-induced putative kinase 1 (PINK1)/Parkin-dependent pathway. However, other Parkin-independent pathways are also reported to mediate the tethering of mitochondria to the autophagy apparatuses, directly activating mitophagy (mitophagy receptors and other E3 ligases). In addition, the existence of molecular mechanisms other than PINK1-mediated phosphorylation for Parkin activation was proposed. The adenosine5′-monophosphate (AMP)-activated protein kinase (AMPK) is emerging as a key player in mitochondrial metabolism and mitophagy. Beyond its involvement in mitochondrial fission and autophagosomal engulfment, its interplay with the PINK1–Parkin pathway is also reported. Here, we review the recent advances in elucidating the canonical molecular mechanisms and signaling pathways that regulate mitophagy, focusing on the early role and spatial specificity of the AMPK/ULK1 axis.

scholarly journals Molecular signature and target-specificity of inhibitory circuits formed by Martinotti cells in the mouse barrel cortex

2021 ◽  
Author(s):  
Cristina Donato ◽  
Carolina Cabezas ◽  
Andrea Aguirre ◽  
Joana Lourenço ◽  
Marie-Claude Potier ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Barrel Cortex ◽  
Functional Expression ◽  
Molecular Signature ◽  
Brain Diseases ◽  
Connectivity Pattern ◽  
Biophysical Properties ◽  
Molecular Fingerprint ◽  
Inhibitory Circuits ◽  
Sensory Evoked

AbstractIn the neocortex, fast synaptic inhibition orchestrates both spontaneous and sensory-evoked activity. GABAergic interneurons (INs) inhibit pyramidal neurons (PNs) directly, modulating their output activity and thus contributing to balance cortical networks. Moreover, several IN subtypes also inhibit other INs, forming specific disinhibitory circuits, which play crucial roles in several cognitive functions. Here, we studied a homogeneous subpopulation of somatostatin (SST)-positive INs, the Martinotti cells (MCs) in layer 2/3 of the mouse barrel cortex (both sexes). MCs are a prominent IN subclass inhibiting the distal portion of PN apical dendrites, thus controlling dendrite electrogenesis and synaptic integration. Yet, it is poorly understood whether MCs inhibit other elements of the cortical circuits, and the connectivity properties with non-PN targets are unknown. We found that MCs have a strong preference for PN dendrites, but they also considerably connect with parvalbumin (PV)-positive, vasoactive intestinal peptide (VIP)-expressing and layer 1 (L1) INs. Remarkably, GABAergic synapses from MCs exhibited clear cell-type-specific short-term plasticity. Moreover, whereas the biophysical properties of MC-PN synapses were consistent with distal dendritic inhibition, MC-IN synapses exhibited characteristics of fast perisomatic inhibition. Finally, MC-PN connections used α5-containing GABAARs, but this subunit was not expressed by the other INs targeted by MCs. We reveal a specialized connectivity blueprint of MCs within different elements of superficial cortical layers. In addition, our results identify α5-GABAARs as the molecular fingerprint of MC-PN dendritic inhibition. This is of critical importance, given the role of α5-GABAARs in cognitive performance and their involvement in several brain diseases.Significance statementMartinotti cells (MCs) are a prominent subclass of SST-expressing GABAergic INs, specialized in controlling distal dendrites of PNs and taking part in several cognitive functions. Here we characterize the connectivity pattern of MCs with other INs in the superficial layers (L1 and L2/3) of the mouse barrel cortex. We found that the connectivity pattern of MCs with PNs as well as PV, VIP and L1 INs exhibit target-specific plasticity and biophysical properties. The stark specificity of α5-GABAARs at MC-PN synapses, and the lack or functional expression of this subunit by other cell types, define the molecular identity of MC-PN connections and the exclusive involvement of this outstanding inhibitory circuits in α5-dependent cognitive tasks.

scholarly journals Role of N-Linked Glycosylation in PKR2 Trafficking and Signaling

2021 ◽  
Vol 15 ◽  
Author(s):  
Jissele A. Verdinez ◽  
Julien A. Sebag
Keyword(s):  
Plasma Membrane ◽  
Energy Homeostasis ◽  
Reproductive Function ◽  
Receptor Trafficking ◽  
Membrane Localization ◽  
Accessory Protein ◽  
Post Translational Modification ◽  
Physiological Processes ◽  
Glycosylation Sites

Prokineticin receptors are GPCRs involved in several physiological processes including the regulation of energy homeostasis, nociception, and reproductive function. PKRs are inhibited by the endogenous accessory protein MRAP2 which prevents them from trafficking to the plasma membrane. Very little is known about the importance of post-translational modification of PKRs and their role in receptor trafficking and signaling. Here we identify 2 N-linked glycosylation sites within the N-terminal region of PKR2 and demonstrate that glycosylation of PKR2 at position 27 is important for its plasma membrane localization and signaling. Additionally, we show that glycosylation at position 7 results in a decrease in PKR2 signaling through Gαs without impairing Gαq/11 signaling.

Bacterial Protein Mimetic of Peptide Hormone as a New Class of Protein- based Drugs

2019 ◽  
Vol 26 (3) ◽  
pp. 546-553 ◽  
Author(s):  
Sergueï O. Fetissov ◽  
Romain Legrand ◽  
Nicolas Lucas
Keyword(s):  
Energy Homeostasis ◽  
In Silico Analysis ◽  
Peptide Hormone ◽  
Intercellular Signaling ◽  
E Coli ◽  
Melanocyte Stimulating Hormone ◽  
New Class ◽  
Bacterial Proteins ◽  
Physiological Processes ◽  
New Type

Specific peptide molecules classified as hormones, neuropeptides and cytokines are involved in intercellular signaling regulating various physiological processes in all organs and tissues. This justifies the peptidergic signaling as an attractive pharmacological target. Recently, a protein mimetic of a peptide hormone has been identified in Escherichia coli suggesting the potential use of specific bacterial proteins as a new type of peptide-like drugs. We review the scientific rational and technological approaches leading to the identification of the E. coli caseinolytic protease B (ClpB) homologue protein as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a melanocortin peptide critically involved in the regulation of energy homeostasis in humans and animals. Theoretical and experimental backgrounds for the validation of bacterial ClpB as a potential drug are discussed based on the known E. coli ClpB amino acid sequence homology with α-MSH. Using in silico analysis, we show that other protein sources containing similar to E. coli ClpB α-MSH-like epitopes with potential biological activity may exist in Enterobacteriaceae and in some Brassicaceae. Thus, the original approach leading to the identification of E. coli ClpB as an α-MSH mimetic protein can be applied for the identification of mimetic proteins of other peptide hormones and development of a new type of peptide-like protein-based drugs.

Sign in / Sign up

Export Citation Format

Share Document