Author Archives: David Worrell

Evaluation of cannabinoid type 2 receptor expression and pyridine-based radiotracers in brains from a mouse model of Alzheimer’s disease

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Frontiers - Crunchbase Company Profile & Funding

“Neuroinflammation plays an important role in the pathophysiology of Alzheimer’s disease. The cannabinoid type 2 receptor (CB2R) is an emerging target for neuroinflammation and therapeutics of Alzheimer’s disease. Here, we aim to assess the alterations in brain CB2R levels and evaluate novel CB2R imaging tracers in the arcAß mouse model of Alzheimer’s disease amyloidosis. Immunohistochemical staining for amyloid-ß deposits (6E10), microgliosis (anti-Iba1 and anti-CD68 antibodies), astrocytes (GFAP) and the anti-CB2R antibody was performed on brain slices from 17-month-old arcAß mice. Autoradiography using the CB2R imaging probes [18F]RoSMA-18-d6, [11C]RSR-056, and [11C]RS-028 and mRNA analysis were performed in brain tissue from arcAß and non-transgenic littermate (NTL) mice at 6, 17, and 24 months of age. Specific increased CB2R immunofluorescence intensities on the increased number of GFAP-positive astrocytes and Iba1-positive microglia were detected in the hippocampus and cortex of 17-month-old arcAß mice compared to NTL mice. CB2R immunofluorescence was higher in glial cells inside 6E10-positive amyloid-ß deposits than peri-plaque glial cells, which showed low background immunofluorescence in the hippocampus and cortex of 17-month-old arcAß mice. Ex vivo autoradiography showed that the specific binding of [18F]RoSMA-18-d6 and [11C]RSR-056 was comparable in arcAß and NTL mice at 6, 17, and 24 months of age. The level of Cnr2 mRNA expression in the brain was not significantly different between arcAß and NTL mice at 6, 17, or 24 months of age. In conclusion, we demonstrated pronounced specific increases in microglial and astroglial CB2R expression levels in a mouse model of AD-related cerebral amyloidosis, emphasizing CB2R as a suitable target for imaging neuroinflammation.”

https://pubmed.ncbi.nlm.nih.gov/36248003/

https://www.frontiersin.org/articles/10.3389/fnagi.2022.1018610/full

Design and function of targeted endocannabinoid nanoparticles

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Scientific Reports

“Nanoparticles and nano-delivery systems are constantly being refined and developed for biomedical applications such as imaging, gene therapy, and targeted delivery of drugs. Nanoparticles deliver beneficial effects by both release of their cargo and by liberation of their constitutive structural components. The N-acylethanolamines linoleoyl ethanolamide (LEA) and oleoyl ethanolamide (OEA) both exhibit endocannabinoid-like activity. Here, we report on their ability to form nanoparticles that when conjugated with tissue-specific molecules, are capable of localizing to specific areas of the body and reducing inflammation. The facilitation of pharmacological effects by endocannabinoids at targeted sites provides a novel biocompatible drug delivery system and a therapeutic approach to the treatment, patient management and quality of life, in conditions such as arthritis, epilepsy, and cancer.”

https://pubmed.ncbi.nlm.nih.gov/36241847/

https://www.nature.com/articles/s41598-022-21715-1

Endocannabinoid signaling in microglia

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“Microglia, the innate immune cells of the central nervous system (CNS), execute their sentinel, housekeeping and defense functions through a panoply of genes, receptors and released cytokines, chemokines and neurotrophic factors. Moreover, microglia functions are closely linked to the constant communication with other cell types, among them neurons. Depending on the signaling pathway and type of stimuli involved, the outcome of microglia operation can be neuroprotective or neurodegenerative. Accordingly, microglia are increasingly becoming considered cellular targets for therapeutic intervention.

Among signals controlling microglia activity, the endocannabinoid (EC) system has been shown to exert a neuroprotective role in many neurological diseases.

Like neurons, microglia express functional EC receptors and can produce and degrade ECs. Interestingly, boosting EC signaling leads to an anti-inflammatory and neuroprotective microglia phenotype. Nonetheless, little evidence is available on the microglia-mediated therapeutic effects of EC compounds.

This review focuses on the EC signals acting on the CNS microglia in physiological and pathological conditions, namely on the CB1R, CB2R and TRPV1-mediated regulation of microglia properties. It also provides new evidence, which strengthens the understanding of mechanisms underlying the control of microglia functions by ECs.

Given the broad expression of the EC system in glial and neuronal cells, the resulting picture is the need for in vivo studies in transgenic mouse models to dissect the contribution of EC microglia signaling in the neuroprotective effects of EC-derived compounds.”

https://pubmed.ncbi.nlm.nih.gov/36222019/

https://onlinelibrary.wiley.com/doi/10.1002/glia.24281

Tonic Endocannabinoid Levels Modulate Retinal Signaling

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ijerph-logo

“The endocannabinoid (eCB) system is critically involved in the modulation of synaptic transmission in the central nervous system, playing an important role in the control of emotional responses, neurodevelopment and synaptic plasticity among other functions. The eCB system is also present in the retina, with studies indicating changes in function after application of cannabinoid receptor agonists, antagonists and in knockout models. Whether eCBs are tonically released in the retina and their physiological functions is, however, still unknown. We investigated the role of the eCB system in the modulation of response strength of retinal ganglion cells (RGCs) to light stimulation, their receptive field organization, contrast sensitivity and excitability properties by performing whole-cell patch-clamp recordings in mouse RGCs before and after bath application of URB597, an inhibitor of the enzyme that degrades the eCB anandamide. Our results show that URB597 application leads to a reduction in the strength of synaptic inputs onto RGCs but paradoxically increases RGC excitability. In addition, URB597 was shown to modulate receptive field organization and contrast sensitivity of RGCs. We conclude that tonically released eCBs modulate retinal signaling by acting on traditional cannabinoid receptors (CB1R/CB2R) as well as on non-cannabinoid receptor targets. Thus, a thorough understanding of the effects of drugs that alter the endogenous cannabinoid levels and of exogenous cannabinoids is necessary to fully comprehend the impact of their medical as well as recreational use on vision.”

https://pubmed.ncbi.nlm.nih.gov/36231760/

https://www.mdpi.com/1660-4601/19/19/12460/htm

Cannabidiol inhibits microglia activation and mitigates neuronal damage induced by kainate in an in-vitro seizure model

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Neurobiology of Disease

“Background: Epilepsy is one of the most common brain disorder and, despite the possible use of several therapeutic options, many patients continue to have seizures for their entire lifespan and they need new therapeutic approaches. In the last years the interest on the non-psychoactive compounds present in Cannabis sativa has massively increased, and cannabidiol (CBD) has been shown to be effective in the treatment of different types of neurological disorders and neurodegenerative diseases such as epilepsy, ischemia, multiple sclerosis and Alzheimer’s Disease.

Methods: We investigated the effects of the selected cannabinoids, Δ9-tetrahydrocannabinol (THC), CBD and cannabigerol (CBG) in rat organotypic hippocampal slices exposed to kainate, an in vitro seizure model. Cell death in the cornu Ammonis 3 (CA3) hippocampal subregion was quantified by propidium iodide fluorescence. Morphological analysis and tissue organization were examined by immunohistochemistry and confocal microscopy and microglia activation and polarization was evaluated using flow cytometry and morphology analysis .

Results: When present in the incubation medium, cannabidiol reduced dose-dependent CA3 injury induced by kainate. Conversely, incubation with THC exacerbated hippocampal damage. The neuroprotective effects of cannabidiol were blocked by TRPV1, TRPV2, 5-HT1A, and PPARγ antagonists. Confocal microscopy confirmed that CBD but not THC had a significant protective effect against neuronal damage and tissue disorganization caused by kainate. Cannabidiol incubation significantly block the microglia activation from the M0 to M1 phenotype observed in the kainate in-vitro seizure model, pushing toward a transition from M0 to M2 .

Conclusions: Our results suggest that CBD mitigated neuronal damage induced by kainate and blocked the transition from the M0 to the M1 phenotype.”

https://pubmed.ncbi.nlm.nih.gov/36240948/

“These findings support the idea that CBD may became a valid and safe therapeutic intervention in the treatment of epilepsy.”

https://www.sciencedirect.com/science/article/pii/S09999612200287X?via%3Dihub

Cannabinoid receptor-2 attenuates neuroinflammation by promoting autophagy-mediated degradation of the NLRP3 inflammasome post spinal cord injury

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Frontiers - Crunchbase Company Profile & Funding

“Background: Neuroinflammation following spinal cord injury (SCI) results in prolonged neurological damage and locomotor dysfunction. Polarization of microglia is vital to regulation of neuroinflammation, although the underlying mechanisms have not yet been elucidated. Endocannabinoid receptor subtype 2 (CB2R) is reported to ameliorate neurodegeneration via immunomodulation activities. However, the underlying machinery in the context of SCI remains unclear.

Methods: A lipopolysaccharide-induced microglia inflammation model and a mouse model of SCI were employed to investigate the regulatory role of CB2R in the polarization of microglia in response to excess neuroinflammation. Markers of inflammation and autophagy were measured by Western blot analysis, immunofluorescence, flow cytometry, and enzyme-linked immunosorbent assays. Histological staining with hematoxylin and eosin, Nissl, and Luxol® fast blue was conducted using commercial kits. The locomotor function of the hindlimbs of the experimental mice was evaluated with the Basso Mouse Scale, Louisville Swim Scale, and footprint assay.

Results: The results showed that CB2R promoted M2 differentiation, increased interleukin (IL)-10 expression, and inhibited M1 differentiation with decreased expression of IL-1β and IL-6. CB2R activation also increased ubiquitination of the NLRP3 inflammasome and interacted with the autophagy-related proteins p62 and microtubule-associated proteins 1B light chain 3. Treatment with the CB2R activator JWH-133 reduced loss of myelin, apoptosis of neurons, and glial scarring, leading to improved functional recovery of the hindlimbs, while the CB2R antagonist AM630 produced opposite results.

Conclusion: Taken together, these results suggested that CB2R activation attenuated neuroinflammation targeting microglial polarization by promoting NLRP3 clearance, thereby facilitating functional recovery post-SCI.”

https://pubmed.ncbi.nlm.nih.gov/36238284/

https://www.frontiersin.org/articles/10.3389/fimmu.2022.993168/full

Pilot clinical and pharmacokinetic study of Δ9-Tetrahydrocannabinol (THC)/Cannabidiol (CBD) nanoparticle oro-buccal spray in patients with advanced cancer experiencing uncontrolled pain

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Lopiccolo & Chang in PLoS ONE – BU Linguistics

“This pilot study aimed to assess the safety, tolerability, pharmacokinetics and exploratory analgesic effect of a novel water-soluble oro-buccal nanoparticle spray of a cannabis-based medicine (MDCNS-01) in patients with advanced incurable malignancy with unrelieved pain from opioid analgesic. The study was a non-blinded single arm 2 stage study. Stage I was a single escalating dose (n = 5) [2.5 mg Δ9-THC and 2.5 mg CBD) versus a 3-fold escalated dose. Stage II was an up-titrated dose in patients with advanced cancers and intractable pain (n = 25). During Stage I with an increased cannabis-based medicine dose, maximum observed plasma concentrations of cannabinoids were dose dependant. The water-soluble formulation in the current study resulted in a higher median (min, max) systemic exposure of Δ9-THC than CBD (AUC from 2.5 mg each of Δ9-THC and CBD, was 1.71 ng mL.h-1 (1.1, 6.6) and 0.65 ng mL.h-1 (0.49, 4.1), respectively). During stage II a subgroup of patients diagnosed with breast and prostate cancers with bone metastases, had the highest mean pain score improvement from baseline of 40% (unadjusted) and 33% (adjusted for rescue medication use). For all patients the most reported adverse events were mild or moderate drowsiness affecting 11 (44%) and 4 (6%) patients, respectively, and nausea and vomiting that affected 18 (72%) patients. The water-soluble cannabis-based medicine provided acceptable bioavailability for Δ9-THC/CBD, appeared safe and tolerable in advanced incurable cancers with uncontrolled pain with preliminary evidence of analgesic efficacy.”

https://pubmed.ncbi.nlm.nih.gov/36240167/

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0270543

Anti-inflammatory potential of delta-9-tetrahydrocannabinol in hyperinsulinemia: an experimental study

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SpringerLink

“Background: Hyperinsulinemia (HI) means that the amount of insulin in the blood is higher than normal and is often associated with type 2 diabetes. It is known that delta-9-tetrahydrocannabinol (THC) obtained from a medicinal plant, Cannabis sativa, has therapeutic effects on many diseases.

Objective: This study aimed to investigate the effects of THC on inflammatory and oxidant status in rat pancreas with HI.

Methods: Rats were divided into groups; Control, HI, THC and HI + THC. Each group consists of 8 animals. HI and HI + THC groups were given 10% fructose in the drinking water for 12 weeks. In the last four weeks of the experiment, 1.5 mg kg-1 THC was injected intraperitoneally daily into THC and HI + THC groups. The expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nuclear factor-kappa B (NF-κB) were detected. JNK/SAPK and Grap2/p38 levels, total antioxidant and oxidant capacities (TAC and TOC) were analyzed in the pancreas.

Results: Levels of IL-6, NF-κβ, and TNF-α mRNA expression were higher in the pancreas with HI than in the control (p < 0.001 for all). THC treatment reduced the expression of IL-6, NF-κβ, and TNF-α mRNAs in the HI + THC group compared to the HI group (p < 0.001 for all). TOC increased in the HI group compared to the control group (p < 0.001). However, THC treatment reduced TOC levels in the HI + THC group compared to the HI group (p < 0.001).

Conclusion: According to the results, the THC treatment may regulate inflammation and TOC in rats with hyperinsulinemia. Thus, we can say that THC may have anti-inflammatory and antioxidant potential in metabolic disorders.”

https://pubmed.ncbi.nlm.nih.gov/36239881/

https://link.springer.com/article/10.1007/s11033-022-07996-9

Oxidative Stress and Autophagy Mediate Anti-Cancer Properties of Cannabis Derivatives in Human Oral Cancer Cells

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cancers-logo

“Cannabinoids, the active components of cannabis exert palliative effects in cancer patients by preventing nausea, vomiting and pain as well as by stimulating appetite.

Recent studies indicated that cannabinoids could be helpful in treating certain rare forms of cancer and other inflammatory diseases.

The objective of this study was to investigate the cytotoxic effect of a cannabinoid mixture (CM) in oral cells. Thus, normal and cancer gingival cells were treated with different concentrations of CM to evaluate their proliferation by MTT assay, cytotoxicity by using LDH assay, colony formation with crystal violet and migration by the scratch method. In addition, apoptosis, autophagy, oxidative stress, antioxidant level, DNA damage and the mitochondrial membrane potential (ΔΨm) generated by proton pumps were measured by flow cytometry. Furthermore, deactivation of the key signaling pathways involved in cancer progression such as NF-κB, ERK1/2, p38, STAT1, STAT3, STAT5 was also evaluated by this technique.

These outcomes indicate that CM, at a concentration higher than 0.1 µg/mL, provokes high cytotoxicity in Ca9-22 oral cancer cells but not in GMSM-K gingival normal cells. Apoptosis, autophagy, antioxidant levels and mitochondrial stress as well as DNA damage in oral cells were increased following exposure to low concentration (1 µg/mL). In addition, major signaling pathways that are involved such as MAPKase, STATs and NF-κB pathways were inhibited by CM as well as cell migration.

Our results suggest that cannabinoids could potentially have a beneficial effect on oral cancer therapy.”

https://pubmed.ncbi.nlm.nih.gov/36230847/

“The therapeutic efficacy of cannabis is very limited and still needs to be confirmed or refuted. However, our recent work has shown that at low doses, cannabinoids (Δ9-THC and Δ8-THC), which are the main constituents of cannabis, are beneficial against oral cancer. In this current study, we showed that a mixture of cannabinoids (CM) can induce oral toxicity in cells by damaging the DNA and activating the mechanisms of autophagy and apoptosis along with inhibiting many cancer progression pathways such as MAPKase, STATs and NF-κB pathways. These data demonstrated clearly the potential beneficial effect of CM at low concentrations for oral cancer therapy.”

https://www.mdpi.com/2072-6694/14/19/4924/htm

The Cytotoxic Effect of Isolated Cannabinoid Extracts on Polypoid Colorectal Tissue

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ijms-logo

“Purified cannabinoids have been shown to prevent proliferation and induce apoptosis in colorectal carcinoma cell lines.

To assess the cytotoxic effect of cannabinoid extracts and purified cannabinoids on both colorectal polyps and normal colonic cells, as well as their synergistic interaction. Various blends were tested to identify the optimal synergistic effect.

Methods: Biopsies from polyps and healthy colonic tissue were obtained from 22 patients undergoing colonic polypectomies. The toxicity of a variety of cannabinoid extracts and purified cannabinoids at different concentrations was evaluated. The synergistic effect of cannabinoids was calculated based on the cells’ survival.

Isolated cannabinoids illustrated different toxic effects on the viability of cells derived from colorectal polyps. THC-d8 and THC-d9 were the most toxic and exhibited persistent toxicity in all the polyps tested. CBD was more toxic to polypoid cells in comparison to normal colonic cells at a concentration of 15 µM. The combinations of the cannabinoids CBDV, THCV, CBDVA, CBCA, and CBGA exhibited a synergistic inhibitory effect on the viability of cells derived from colon polyps of patients.

Isolated cannabinoid compounds interacted synergistically against colonic polyps, and some also possessed a differential toxic effect on polyp and adjacent colonic tissue, suggesting possible future therapeutic value.”

https://pubmed.ncbi.nlm.nih.gov/36232668/

“To conclude, our study results support the potential cytotoxic effect of cannabinoid extracts on colorectal polyps, as well as their synergistic and differential interactions. Further studies examining this postulation and the ultimate combination of cannabinoids for inhibiting/decreasing the recurrence rate of neoplastic polyps, and for preventing their malignant transformation into adenocarcinoma, are needed.”

https://www.mdpi.com/1422-0067/23/19/11366/htm