oromucosal-as-an-alternative-method-for-administration-cannabis

Oromucosal as an Alternative Method for Administration of Cannabis Products in Rodents

Oral administration of drugs in laboratory rodents such as rats is conventionally performed using the gavage technique. Despite effectiveness, gavage can ...

Universidade Federal do Rio de Janeiro

Cholesterol is a sterol lipid that plays pleiotropic roles in the plasma membrane; it is involved in maintaining membrane fluidity and permeability and the structure of lipid microdomains. Despite its importance, the consequences of membrane cholesterol depletion during cardiac differentiation have not been described. Therefore, we investigated the cellular and molecular mechanisms associated with cholesterol depletion in cultures of chick cardiac cells. We used methyl-beta-cyclodextrin (MCD) to deplete membrane cholesterol and investigate its role in cardiac differentiation by following the expression of several markers including the transcriptional factor Nkx2.5, the myofibrillar protein tropomyosin, the cytoskeletal intermediate filament protein desmin, the caveolar protein caveolin-3, the cadherin/beta-catenin adhesion complex, and the junctional protein connexin 43. Confocal microscopy showed that desmin-positive cells were located more externally in the aggregates in relation to the more internally located caveolin-3-positive cells. Desmin and caveolin-3 were co-localized in filamentous structures in the subsarcolemmal region of well-spread cells outside the aggregates. beta-Catenin was concentrated in regions of cell-cell contact, and tropomyosin in sarcomeric structures. Western blot tests showed that immediately following cholesterol depletion, there was a slight decrease in the expression of caveolin-3 and desmin, and at the same time there was a sharp increase in the expression of cadherin, tropomyosin, Nkx2.5 and connexin 43. Further, we found an increase in the expression of cardiac beta-myosin heavy chain 7, a marker of the cardiac hypertrophic phenotype. These observations suggest that membrane cholesterol plays a significant role in regulating cardiomyocyte differentiation.

Membrane cholesterol depletion by methyl-beta-cyclodextrin enhances the expression of cardiac differentiation markers.

Muscle fibers are formed during embryonic development by the fusion of mononucleated myoblasts. The spatial structure and molecular composition of the sarcolemma are crucial for the myoblast recognition and fusion steps. Cyclodextrins are a group of substances that have the ability to solubilize lipids through the formation of molecular inclusion complexes. Previously, we have shown that methyl-β-cyclodextrin (MbCD) enhances muscle differentiation. Here, we analyzed the effects of α-cyclodextrin (aCD) during myogenesis. Myogenic cultures treated with aCD showed an increase in myoblast fusion and in the expression of myogenin, sarcomeric tropomyosin and desmin. aCD-conditioned media accelerates myogenesis in a similar way as aCD does, and increased levels of IL-4 were found in aCD-conditioned media. aCD-induced effects on myogenesis were inhibited by an anti-IL4 antibody. These results show that α-cyclodextrin induces myogenic differentiation by the release of IL-4.

α-Cyclodextrin enhances myoblast fusion and muscle differentiation by the release of IL-4.

The avian retina has been used as a model to study signaling by different neuro- and gliotransmitters. It is unclear how dopaminergic and cannabinoid systems are related in the retina. Here we studied the expression of type 1 and 2 cannabinoid receptors (CB and CB), as well as monoacylglycerol lipase (MAGL), the enzyme that degrades 2-arachidonoylglycerol (2-AG), during retina development. Our data show that CB receptor is highly expressed from embryonic day 5 (E5) until post hatched day 7 (PE7), decreasing its levels throughout development. CB is densely found in the ganglion cell layer (GCL) and inner plexiform layer (IPL). CB receptor was also found from E5 until PE7 with a decrease in its contents from E9 afterwards. CB was mainly present in the lamination of the IPL at PE7. MAGL is expressed in all retinal layers, mainly in the IPL and OPL from E9 to PE7 retina. CB and CB were found both in neurons and glia cells, but MAGL was only expressed in Müller glia. Older retinas (PE7) show CB positive cells mainly in the INL and co-expression of CB and tyrosine hydroxylase (TH) are shown in a few cells when both systems are mature. CB co-localized with TH and was heavily associated to D receptor labeling in primary cell cultures. Finally, cyclic AMP (cAMP) was activated by the selective D agonist SKF38393, and inhibited when cultures were treated with WIN55, 212-2 (WIN) in a CB dependent manner. The results suggest a correlation between the endocannabinoid and dopaminergic systems (DSs) during the avian retina development. Activation of CB limits cAMP accumulation via D receptor activation and may influence embryological parameters during avian retina differentiation.

Cannabinoid Receptor Type 1 Expression in the Developing Avian Retina: Morphological and Functional Correlation With the Dopaminergic System.

GABA transporters regulate synaptic GABA levels and dysfunctions in this system might result in psychiatric disorders. The endocannabinoid system (ECS) is the main circuit breaker in the nervous system and may alter noradrenaline (NA) communication, which in turn modulates the release of GABA. However, a close relationship between these systems has not been recognized. We asked whether NA and ECS might control extracellular GABA levels in slices of frontal cortex (FC) of adolescent Swiss mice with 40 days after birth (PN40). Here we show that NA and isoproterenol (ISO), a beta-adrenergic agonist, increased [H]-GABA uptake in mice FC, while alpha-adrenergic agonist phenylephrine had no effect. As GAT-1 is expressed and fully functional at the FC, addition of NO-711, a GAT-1 inhibitor, dose dependently blocked [H]-GABA uptake. The increase of [H]-GABA uptake induced by ISO was also blocked by NO-711. [H]-GABA release induced by 80 mM KCl was reduced by NO-711, but not by removal of Ca. ISO also increased cyclic AMP (cAMP) levels and addition of WIN 55,212-2, a mixed CB/CB receptor agonist, inhibited the effect of ISO in GABA uptake increase, GAT-1 expression and cAMP levels compared to control. Our data show that GABA transport increased by NA and ISO is negatively regulated by cannabinoid receptor agonist WIN55,212-2.

Beta-adrenergic receptor activation increases GABA uptake in adolescent mice frontal cortex: Modulation by cannabinoid receptor agonist WIN55,212-2.

Serotonin (5-HT) has been recognized as a neurotransmitter in the vertebrate retina, restricted mainly to amacrine and bipolar cells. It is involved with synaptic processing and possibly as a mitogenic factor. We confirm that chick retina amacrine and bipolar cells are, respectively, heavily and faintly immunolabeled for 5-HT. Amacrine serotonergic cells also co-express tyrosine hydroxylase (TH), a marker of dopaminergic cells in the retina. Previous reports demonstrated that serotonin transport can be modulated by neurotransmitter receptor activation. As 5-HT is diffusely released as a neuromodulator and co-localized with other transmitters, we evaluated if 5-HT uptake or release is modulated by several mediators in the avian retina. The role of different glutamate receptors on serotonin transport and release in vitro and in vivo was also studied. We show that L-glutamate induces an inhibitory effect on [H]5-HT uptake and this effect was specific to kainate receptor activation. Kainate-induced decrease in [H]5-HT uptake was blocked by CNQX, an AMPA/kainate receptor antagonist, but not by MK-801, a NMDA receptor antagonist. [H]5-HT uptake was not observed in the presence of AMPA, thus suggesting that the decrease in serotonin uptake is mediated by kainate. 5-HT (10-50 μM) had no intrinsic activity in raising intracellular Ca, but addition of 10 μM 5-HT decreased Ca shifts induced by KCl in retinal neurons. Moreover, kainate decreased the number of bipolar and amacrine cells labeled to serotonin in chick retina. In conclusion, our data suggest a highly selective effect of kainate receptors in the regulation of serotonin functions in the retinal cells.

Regulation of the Serotonergic System by Kainate in the Avian Retina.

The active principles of Cannabis sativa are potential treatments for several diseases, such as pain, seizures and anorexia. With the increase in the use of cannabis for medicinal purposes, a more careful assessment of the possible impacts on embryonic development becomes necessary. Surveys indicate that approximately 3.9% of pregnant women use cannabis in a recreational and/or medicinal manner. However, although the literature has already described the presence of endocannabinoid system components since the early stages of CNS development, many of their physiological effects during this stage have not yet been established. Moreover, it is still uncertain how the endocannabinoid system can be altered in terms of cell proliferation and cell fate, neural migration, neural differentiation, synaptogenesis and particularly cell death. In relation to cell death in the CNS, knowledge about the effects of cannabinoids is scarce. Thus, the present work aims to review the role of the endocannabinoid system in different aspects of CNS development and discuss possible side effects or even opportunities for treating some conditions in the development of this tissue.

Article	Year
Membrane cholesterol depletion by methyl-beta-cyclodextrin enhances the expression of cardiac differentiation markers. Cells, tissues, organs\| PubMed ID: 20523034	2010
α-Cyclodextrin enhances myoblast fusion and muscle differentiation by the release of IL-4. Cytokine\| PubMed ID: 21570315	2011
Cannabinoid Receptor Type 1 Expression in the Developing Avian Retina: Morphological and Functional Correlation With the Dopaminergic System. Frontiers in cellular neuroscience\| PubMed ID: 29662438	2018
Beta-adrenergic receptor activation increases GABA uptake in adolescent mice frontal cortex: Modulation by cannabinoid receptor agonist WIN55,212-2. Neurochemistry international\| PubMed ID: 30170018	2018
Regulation of the Serotonergic System by Kainate in the Avian Retina. Cellular and molecular neurobiology\| PubMed ID: 31197744	2019
The Role of Cannabinoids in CNS Development: Focus on Proliferation and Cell Death. Cellular and molecular neurobiology\| PubMed ID: 35925507	2023

Luzia Silva Sampaio

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