Anandamide, Acting via CB2 Receptors, Alleviates LPS-Induced Neuroinflammation in Rat Primary Microglial Cultures.

“Microglial activation is a polarized process divided into potentially neuroprotective phenotype M2 and neurotoxic phenotype M1, predominant during chronic neuroinflammation.

Endocannabinoid system provides an attractive target to control the balance between microglial phenotypes.

Anandamide as an immune modulator in the central nervous system acts via not only cannabinoid receptors (CB1 and CB2) but also other targets (e.g., GPR18/GPR55).

In summary, we showed that the endocannabinoid system plays a crucial role in the management of neuroinflammation by dampening the activation of an M1 phenotype. This effect was primarily controlled by the CB2 receptor, although functional cross talk with GPR18/GPR55 may occur.”

http://www.ncbi.nlm.nih.gov/pubmed/26090232

Endocannabinoids drive the acquisition of an alternative phenotype in microglia.

“The ability of microglia to acquire diverse states of activation, or phenotypes, reflects different features that are determinant for their contribution to homeostasis in the adult CNS, and their activity in neuroinflammation, repair or immunomodulation.

Despite the widely reported immunomodulatory effects of cannabinoids in both the peripheral immune system and the CNS, less is known about how the endocannabinoid signaling system (eCBSS) influence the microglial phenotype.

The general aim of the present study was to investigate the role of endocannabinoids in microglia polarization by using microglia cell cultures.

We show that alternative microglia (M2a) and acquired deactivated microglia (M2c) exhibit changes in the eCB machinery that favor the selective synthesis of 2-AG and AEA, respectively.

Once released, these eCBs might be able to act through CB1 and/or CB2 receptors in order to influence the acquisition of an M2 phenotype.

We present three lines of evidence that the eCBSS is critical for the acquisition of the M2 phenotype: (i) M2 polarization occurs on exposure to the two main endocannabinoids 2-AG and AEA in microglia cultures; (ii)cannabinoid receptor antagonists block M2 polarization; and, (iii) M2 polarization is dampened in microglia from CB2 receptor knockout mice.

Taken together, these results indicate the interest of eCBSS for the regulation of microglial activation in normal and pathological conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/26086345

Neurobiological Interactions Between Stress and the Endocannabinoid System.

“Stress affects a constellation of physiological systems in the body and evokes a rapid shift in many neurobehavioral processes.

A growing body of work indicates that the endocannabinoid (eCB) system is an integral regulator of the stress response.

In the current review, we discuss the evidence to date that demonstrates stress-induced regulation of eCB signaling and the consequential role changes in eCB signaling play with respect to many of the effects of stress.

Across a wide array of stress paradigms, studies have generally shown that stress evokes bidirectional changes in the two eCB molecules, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), with stress exposure reducing AEA levels and increasing 2-AG levels.

Additionally, in almost every brain region examined, exposure to chronic stress reliably causes a down-regulation or loss of cannabinoid type 1 (CB1) receptors.

With respect to the functional role of changes in eCB signaling during stress, studies have demonstrated that the decline in AEA appears to contribute to the manifestation of the stress response, including activation of the hypothalamic-pituitary-adrenal (HPA) axis and increases in anxiety behavior, while the increased 2-AG signaling contributes to termination and adaptation of the HPA axis, as well as potentially contributing to changes in pain perception and synaptic plasticity.

More so, translational studies have shown that eCB signaling in humans regulates many of the same domains and appears to be a critical component of stress regulation, and impairments in this system may be involved in the vulnerability to stress-related psychiatric conditions, such as depression and post-traumatic stress disorder.

Collectively, these data create a compelling argument that eCB signaling is an important regulatory system in the brain that largely functions to buffer against many of the effects of stress and that dynamic changes in this system contribute to different aspects of the stress response.”

http://www.ncbi.nlm.nih.gov/pubmed/26068727

Role of the endocannabinoid system in the emotional manifestations of osteoarthritis pain.

“The levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol.

In this study, we investigated the role of the endocannabinoid system (ECS) in the emotional and cognitive alterations associated with osteoarthritis pain.

Changes found in these biomarkers of the ECS correlated with pain, affective and cognitive symptoms in these patients.

The ECS plays a crucial role in osteoarthritis and represents an interesting pharmacological target and biomarker of this disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26067584

http://www.thctotalhealthcare.com/category/osteoarthritis/

Localization of an endocannabinoid system in the hypophysial pars tuberalis and pars distalis of man.

“The hypophysial pars tuberalis (PT) acts as an important interface between neuroendocrine brain centers (hypothalamus, pineal organ) and the pars distalis (PD) of the hypophysis.

Recently, we have identified an endocannabinoid system in the PT of hamsters and provided evidence that 2-arachidonoylglycerol is a messenger molecule that appears to play an essential role in seasonal reproduction and prolactin release by acting on the cannabinoid receptors in the PD.”

“An endocannabinoid system is localized to the hypophysial pars tuberalis of Syrian hamsters and responds to photoperiodic changes.”  http://www.ncbi.nlm.nih.gov/pubmed/20165884

“We now demonstrate the enzymes involved in endocannabinoid synthesis and degradation, namely sn-1-selective diacylglycerol lipase α, N-acylphosphatidylethanolamine-specific phospholipase D, and monoacylglycerol lipase, in the PT of man by means of immunohistochemistry.

High-performance liquid chromatography coupled with tandem mass spectrometry revealed 2-arachidonoylglycerol and other endocannabinoids in the human PT.

Furthermore, we detected the expression of the cannabinoid receptor 1 (CB1), a primary receptor for endocannabinoids, in the PD.

Our data thus indicate that the human PT comprises an endocannabinoid system, and that corticotrophs and FS-cells are the main target cells for endocannabinoids.

The functional significance of this newly discovered pathway remains to be elucidated in man; it might be related to the control of stress responses and/or reflect a remnant seasonal control of hypophysial hormonal secretion.”

http://www.ncbi.nlm.nih.gov/pubmed/20957495

The rat pineal gland comprises an endocannabinoid system.

“In the mammalian pineal gland, the rhythm in melatonin biosynthesis depends on the norepinephrine (NE)-driven regulation of arylalkylamine N-acetyltransferase (AANAT), the penultimate enzyme of melatonin biosynthesis.

A recent study showed that phytocannabinoids like tetrahydrocannabinol reduce AANAT activity and attenuate NE-induced melatonin biosynthesis in rat pineal glands, raising the possibility that an endocannabinoid system is present in the pineal gland…

In summary, the pineal gland comprises indispensable compounds of the endocannabinoid system indicating that endocannabinoids may be involved in the control of pineal physiology.”

http://www.ncbi.nlm.nih.gov/pubmed/18554250

Rhythmic control of endocannabinoids in the rat pineal gland.

“Endocannabinoids modulate neuroendocrine networks by directly targeting cannabinoid receptors.

The time-hormone melatonin synchronizes these networks with external light condition and guarantees time-sensitive and ecologically well-adapted behaviors.

Here, the endocannabinoid arachidonoyl ethanolamide (AEA) showed rhythmic changes in rat pineal glands with higher levels during the light-period and reduced amounts at the onset of darkness.

Norepinephrine, the essential stimulus for nocturnal melatonin biosynthesis, acutely down-regulated AEA and other endocannabinoids in cultured pineal glands.

These temporal dynamics suggest that AEA exerts time-dependent autocrine and/or paracrine functions within the pineal.

Moreover, endocananbinoids may be released from the pineal into the CSF or blood stream.”

http://www.ncbi.nlm.nih.gov/pubmed/26061461

Inhibition of human neutrophil chemotaxis by endogenous cannabinoids and phytocannabinoids: evidence for a site distinct from CB1 and CB2.

“Here, we show a novel pharmacology for inhibition of human neutrophil migration by endocannabinoids, phytocannabinoids, and related compounds.

This study reveals that certain endogenous lipids, phytocannabinoids, and related ligands are potent inhibitors of human neutrophil migration, and it implicates a novel pharmacological target distinct from cannabinoid CB(1) and CB(2) receptors; this target is antagonized by the endogenous compound N-arachidonoyl l-serine.

Furthermore, our findings have implications for the potential pharmacological manipulation of elements of the endocannabinoid system for the treatment of various inflammatory conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/17965195

Prenatal elevation of endocannabinoids corrects the unbalance between dopamine systems and reduces activity in the Naples High Excitability rats.

“Several evidences suggest that endocannabinoids exert a neurotrophic effect on developing mesencephalic dopamine neurons.

Since an altered mesocorticolimbic system seems to underlie hyperactivity and attention deficit in clinical and animal studies of attention deficit hyperactivity disorder(ADHD), prenatal elevation of anandamide has been induced…

The data suggest a corrected unbalance between the two dopamine systems that apparently leads to reducedhyperactivity and modified scanning times in this animal model of ADHD.

This, in turn, might open new strategies in the treatment of a subset of ADHD cases.”

http://www.ncbi.nlm.nih.gov/pubmed/12732229

Endocannabinoids activate transient receptor potential vanilloid 1 receptors to reduce hyperdopaminergia-related hyperactivity: therapeutic implications.

“Knockout (KO) mice invalidated for the dopamine transporter (DAT) constitute a powerful animal model of neurobiological alterations associated with hyperdopaminergia relevant to schizophrenia and attention-deficit/hyperactivity disorder (ADHD).

CONCLUSIONS:

These data indicate a dysregulated striatal endocannabinoid neurotransmission associated with hyperdopaminergic state.

Restoring endocannabinoid homeostasis in active synapses might constitute an alternative therapeutic strategy for disorders associated with hyperdopaminergia.

In this process, TRPV1 receptors seem to play a key role and represent a novel promising pharmacological target.”

http://www.ncbi.nlm.nih.gov/pubmed/16199010