Cannabinoid as a neuroprotective strategy in perinatal hypoxic-ischemic injury.

“Perinatal hypoxia-ischemia remains the single most important cause of brain injury in the newborn, leading to death or lifelong sequelae.

Because of the fact that there is still no specific treatment for perinatal brain lesions due to the complexity of neonatal hypoxic-ischemic pathophysiology, the search of new neuroprotective therapies is of great interest.

In this regard, therapeutic possibilities of the endocannabinoid system have grown lately.

The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury, acting as a natural neuroprotectant.

Concerning perinatal asphyxia, the neuroprotective role of this endogenous system is emerging these years.

The present review mainly focused on the current knowledge of the cannabinoids as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

http://www.ncbi.nlm.nih.gov/pubmed/21788999

[The cannabinoid system and its importance in the perinatal period].

“The cannabinoid system has been recently described, including the endogenous ligands, mainly arachidonic acid derivatives, and their specific receptors. Endocannabinoids are involved in the modulation of synaptic transmission, through which they exert their psychoactive, motor and antinociceptive effects, among others; they also exert extraneural effects, mainly immunomodulation and vasodilation.

Recent data suggest that the cannabinoid system might play an important role in human ontogeny and could participate in the implantation and early development of the embryo, in fetal brain development, and in the beginning of breast feeding after birth.

In addition, the vasodilatory effect of cannabinoids, together with inhibition of the release of excitotoxic amino acids and cytokines, as well as modulation of oxidative stress and the toxic production of nitric oxide, justify the growing evidence pointing to a possible neuroprotective effect of cannabinoids in perinatal asphyxia.”

http://www.ncbi.nlm.nih.gov/pubmed/16266619

Cannabinoids: well-suited candidates for the treatment of perinatal brain injury.

“Perinatal brain injury can be induced by a number of different damaging events occurring during or shortly after birth… the number of clinical interventions available for the treatment of the affected newborn babies is extremely limited. Hence, there is a dramatic need to develop new effective therapies aimed to prevent acute brain damage and enhance the endogenous mechanisms of long-term brain repair.

The endocannabinoid system is an endogenous neuromodulatory system involved in the control of multiple central and peripheral functions. An early responder to neuronal injury, the endocannabinoid system has been described as an endogenous neuroprotective system that once activated can prevent glutamate excitotoxicity, intracellular calcium accumulation, activation of cell death pathways, microglia activation, neurovascular reactivity and infiltration of circulating leukocytes across the blood-brain barrier.

The modulation of the endocannabinoid system has proven to be an effective neuroprotective strategy to prevent and reduce neonatal brain injury in different animal models and species.

Also, the beneficial role of the endocannabinoid system on the control of the endogenous repairing responses (neurogenesis and white matter restoration) to neonatal brain injury has been described in independent studies.”

http://www.ncbi.nlm.nih.gov/pubmed/24961520

Delta-9 tetrahydrocannabinol (THC) inhibits lytic replication of gamma oncogenic herpesviruses in vitro

Figure 2

“The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC), has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication.

THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC. These studies may also provide the foundation for the development of antiviral strategies utilizing non-psychoactive derivatives of THC.

 We believe that studies on cannabinoids and herpesviruses are important to continue because there are obvious potential benefits. Better understanding may lead to the development of specific non-psychoactive drugs that may inhibit reactivation of oncogenic herpesviruses.”

The Cannabinoid WIN55212-2 Promotes Neural Repair After Neonatal Hypoxia–Ischemia

Figure 1.

“In the last years, cannabinoids have emerged as promising neuroprotective agents in several animal paradigms of acute and degenerative brain damage. Most neuroprotective effects of cannabinoids result from the activation of cannabinoid Type 1 (CB1R) and Type 2 (CB2R) receptors in neural and immune cells.

Besides, the stimulating effect of cannabinoids on proliferation, survival, and differentiation of neural progenitor cells provides interesting prospects for long-term neural repair after acute brain damage.

The endocannabinoid system has been involved in the modulation of neural stem cells proliferation, survival and differentiation as well as in the generation of new oligodendrocyte progenitors in the postnatal brain. The present work aims to test the effect of the synthetic Type 1 and Type 2 cannabinoid receptor agonist WIN55212-2 on these processes in the context of neonatal rat brain hypoxia–ischemia (HI)…

Our results suggest that the activation of the endocannabinoid system promotes white and gray matter recovery after neonatal HI injury…

In conclusion, we have demonstrated that the synthetic cannabinoid WIN55212-2 enhances SVZ cell proliferation, oligodendrogenesis, white matter remyelination, and neuroblast generation after neonatal HI.

These findings, summed to the previously described neuroprotective properties of cannabinoids after acute brain damage, may possess therapeutic repercussions in the long-term management of neonatal HI encephalopathy, a prevalent and devastating condition for which no pharmacological treatments are yet available.”

http://stroke.ahajournals.org/content/41/12/2956.full

 

The endocannabinoid system modulates stress, emotionality, and inflammation.

“The physiological and behavioral effects of stress are well characterized.

Endocannabinoids are produced on demand and function to attenuate many of the physiological effects of the stress response.

The endocannabinoid system is made up of cannabinoid receptors, the fatty acid signaling molecules that bind to and activate these receptors, and the enzymes that synthesize and catabolize these endocannabinoid signaling molecules.

Cannabinoid research has recently grown substantially, due in no small part to the development of genetic research models as well as highly selective pharmaceutical tools.

The purpose of this minireview is to discuss a subset of the many parallels between cannabinoid and behavioral neuroimmunology research, with specific discussion of interactions between the endocannabinoid system and psychological stress, emotionality, and inflammation.”

http://www.ncbi.nlm.nih.gov/pubmed/24953427

Role of ionotropic cannabinoid receptors in peripheral antinociception and antihyperalgesia

Figure 1

“Although cannabinoids have been used for millennia for treating pain and other symptoms, their mechanisms of action remain obscure.

With the heralded identification of multiple G-protein-coupled receptors (GPCRs) mediating cannabinoid effects nearly two decades ago, the mystery of cannabinoid pharmacology was thought to be solved…

Despite the wealth of information on cannabinoid-induced peripheral antihyperalgesic and antinociceptive effects in many pain models, the molecular mechanism(s) for these actions remains unknown.

Although metabotropic cannabinoid receptors have important roles in many pharmacological actions of cannabinoids, recent studies have led to the recognition of a family of at least five ionotropic cannabinoid receptors (ICRs). The known ICRs are members of the family of transient receptor potential (TRP) channels and include TRPV1, TRPV2, TRPV4, TRPM8 and TRPA1.

Cannabinoid activation of ICRs can result in desensitization of the TRPA1 and TRPV1 channel activities, inhibition of nociceptors and antihyperalgesia and antinociception in certain pain models.

Thus, cannabinoids activate both metabotropic and ionotropic mechanisms to produce peripheral analgesic effects.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2863326/

TRP Channel Cannabinoid Receptors in Skin Sensation, Homeostasis, and Inflammation.

“In the skin, cannabinoid lipids, whether of endogenous or exogenous origin, are capable of regulating numerous sensory, homeostatic and inflammatory events.

Although many of these effects are mediated by metabotropic CB receptors, a growing body of evidence has revealed that multiple members of the transient receptor potential (TRP) ion channel family can act as “ionotropic cannabinoid receptors”.

Furthermore, many of these same TRP channels are intimately involved in cutaneous processes that include the initiation of pain, temperature, and itch perception, the maintenance of epidermal homeostasis, the regulation of hair follicles and sebaceous glands, and the modulation of dermatitis.

Ionotropic cannabinoid receptors therefore represent potentially attractive targets for the therapeutic use of cannabinoids to treat sensory and dermatological diseases.

Furthermore, the interactions between neurons and other cell types that are mediated by cutaneous ionotropic cannabinoid receptors are likely to be recapitulated during physiological and pathophysiological processes in the central nervous system and elsewhere, making the skin an ideal setting in which to dissect general complexities of cannabinoid signaling.”

http://www.ncbi.nlm.nih.gov/pubmed/24915599

Reduced endocannabinoid immune modulation by a common cannabinoid 2 (CB2) receptor gene polymorphism: possible risk for autoimmune disorders.

Publication cover image

“Immune system responsiveness results from numerous factors, including endogenous cannabinoid signaling in immunocytes termed the “immunocannabinoid” system. This system can be an important signaling pathway for immune modulation.

To assess the immunomodulating role of the cannabinoid 2 (CB2) receptor, we sought polymorphisms in the human gene, identified a common dinucleotide polymorphism, and investigated its effect on endocannabinoid-induced inhibition of T lymphocyte proliferation.

Collectively, these results demonstrate reduced endogenous fatty acid amide immunomodulatory responses in individuals with the CB2 188-189 GG/GG genotype and suggest that this CB2 gene variation may be a risk factor for autoimmunity.

The results also support the proposition that the CB2 receptor may represent a novel pharmacological target for selective agonists designed to suppress autoreactive immune responses”

https://jlb.onlinelibrary.wiley.com/doi/full/10.1189/jlb.0205111

https://www.ncbi.nlm.nih.gov/pubmed/15845647

Role of Endocannabinoid Activation of Peripheral CB1 Receptors in the Regulation of Autoimmune Disease.

“The impact of the endogenous cannabinoids (AEA, 2-AG, PEA, and virodamine) on the immune cell expressed cannabinoid receptors (CB1, CB2, TRPV-1, and GPR55) and consequent regulation of immune function is an exciting area of research with potential implications in the prevention and treatment of inflammatory and autoimmune diseases.

Despite significant advances in understanding the mechanisms through which cannabinoids regulate immune functions, not much is known about the role of endocannabinoids in the pathogenesis or prevention of autoimmune diseases.

Inasmuch as CB2 expression on immune cells and its role has been widely reported, the importance of CB1 in immunological disorders has often been overlooked especially because it is not highly expressed on naive immune cells.

Therefore, the current review aims at delineating the effect of endocannabinoids on CB1 receptors in T cell driven autoimmune diseases. This review will also highlight some autoimmune diseases in which there is evidence indicating a role for endocannabinoids in the regulation of autoimmune pathogenesis.

Overall, based on the evidence presented using the endocannabinoids, specifically AEA, we propose that the peripheral CB1 receptor is involved in the regulation and amelioration of inflammation associated with autoimmune diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/24911431