Evaluation of common variants in the CNR2 gene and its interaction with abdominal obesity for osteoporosis susceptibility in Chinese post-menopausal females

Single nucleotide polymorphisms in the cannabinoid CB2 receptor: Molecular pharmacology and disease associations

Preclinical evidence implicating cannabinoid receptor 2 (CB2) in various diseases has led researchers to question whether CB2 genetics influence aetiology or progression. Associations between conditions and genetic loci are often studied via single nucleotide polymorphism (SNP) prevalence in case versus control populations. In the CNR2 coding exon, ~36 SNPs have high overall population prevalence (minor allele frequencies [MAF] ~37%), including non-synonymous SNP (ns-SNP) rs2501432 encoding CB2 63Q/R. Interspersed are ~27 lower frequency SNPs, four being ns-SNPs. CNR2 introns also harbour numerous SNPs. This review summarises CB2 ns-SNP molecular pharmacology and evaluates evidence from ~70 studies investigating CB2 genetic variants with proposed linkage to disease. Although CNR2 genetic variation has been associated with a wide variety of conditions, including osteoporosis, immune-related disorders, and mental illnesses, further work is required to robustly validate CNR2 disease links and clarify specific mechanisms linking CNR2 genetic variation to disease pathophysiology and potential drug responses.

Cannabinoid Receptor 2 Gene Polymorphism and the Risk of Developing Rheumatoid Arthritis in Lebanese Patients

Objective: Evidence supports a role of cannabinoid receptor 2 (CB2) in regulating the immune response. Some variations in the CB2 receptor gene (CB2) were linked to the susceptibility of developing rheumatoid arthritis (RA). The aim of this study is to assess the relationship between CNR2 rs2501431 and the risk of developing RA in Lebanese patients. Methods: A total of one hundred five Lebanese RA patients and one hundred five controls participated in the study. CNR2 was genotyped and analyzed. Results: Using χ2 test, our results show that the CC genotype was the most common (47.6%, p<0.00001) and that the C allele highly predominated (64%, p<0.00001) in the RA group compared to the control group. The relative odds ratio show that carriers of the CC genotype have more than 13-fold risk of developing RA as compared to TT. Conclusion: Our results suggest that the rs2501431 variant of CNR2 gene can be considered as a risk factor for RA development, and thus implicate the potential targeting of CB2 receptor for the treatment of RA.

Characterization of Fecal Microbiomes of Osteoporotic Patients in Korea

An imbalanced gut microbiome has been linked to a higher risk of many bone-related diseases. The objective of this study was to discover biomarkers of osteoporosis (OP). So, we collected 76 stool samples (60 human controls and 16 OP patients), extracted DNA, and performed 16S ribosomal ribonucleic acid (rRNA) gene-based amplicon sequencing. Among the taxa with an average taxonomic composition greater than 1%, only the Lachnospira genus showed a significant difference between the two groups. The Linear Discriminant Effect Size analysis and qPCR experiments indicated the Lachnospira genus as a potential biomarker of OP. Moreover, a total of 11 metabolic pathways varied between the two groups. Our study concludes that the genus Lachnospira is potentially crucial for diagnosing and treating osteoporosis. The findings of this study might help researchers better understand OP from a microbiome perspective. This research might develop more effective diagnostic and treatment methods for OP in the future.

GAS5/METTL14/ESR1 genetic variants are related to the susceptibility of coronary heart disease

The prevention and treatment of coronary heart disease (CHD) is a difficult problem to be solved urgently. Genetic factors play a crucial role in CHD development. This study aimed to investigate the association of GAS5/METTL14/ESR1 polymorphisms with CHD susceptibility. We carried out a case-control study that included 506 patients and 506 healthy subjects to detect the correlation between GAS5/METTL14/ESR1 polymorphisms and CHD risk in a Chinese population. Odds ratios (OR) and 95% confidence intervals (CI) were computed to assess the associations. Our study showed that GAS5 rs17359906 (OR 2.32, p = 0.020) and rs75315904 (OR 0.41, p = 0.039) were related to the risk of CHD in females. ESR1 rs6927072 (OR 1.76, p = 0.007) and rs4870061 (OR 0.74, p = 0.036) correlated with CHD risk in age ≤ 60 years. GAS5 rs17359906 (OR 0.10, p = 0.032) and ESR1 rs3020308 (OR 2.73, p = 0.041) were associated with an increased susceptibility to CHD in smokers. We also found that METTL14 rs4834698 (OR 1.57, p = 0.044) and ESR1 rs4870061 (OR 0.62, p = 0.040) were associated with CHD susceptibility in non-drinkers. Besides, METTL14 rs17050450 (OR 0.48, p = 0.029) and ESR1 rs3853248 (OR 1.61, p = 0.018) had the susceptibility of CHD patients with diabetes. Our study indicated that GAS5/METTL14/ESR1 polymorphisms were associated with CHD risk, which might provide a new understanding of CHD in a Chinese population.

N,N-Dimethylformamide inhibits high glucose-induced osteoporosis via attenuating MAPK and NF-κB signalling

Aims

The role of N,N-dimethylformamide (DMF) in diabetes-induced osteoporosis (DM-OS) progression remains unclear. Here, we aimed to explore the effect of DMF on DM-OS development.

Methods

Diabetic models of mice, RAW 264.7 cells, and bone marrow macrophages (BMMs) were established by streptozotocin stimulation, high glucose treatment, and receptor activator of nuclear factor-κB ligand (RANKL) treatment, respectively. The effects of DMF on DM-OS development in these models were examined by micro-CT analysis, haematoxylin and eosin (H&E) staining, osteoclast differentiation of RAW 264.7 cells and BMMs, H&E and tartrate-resistant acid phosphatase (TRAP) staining, enzyme-linked immunosorbent assay (ELISA) of TRAP5b and c-terminal telopeptides of type 1 (CTX1) analyses, reactive oxygen species (ROS) analysis, quantitative reverse transcription polymerase chain reaction (qRT-PCR), Cell Counting Kit-8 (CCK-8) assay, and Western blot.

Results

The established diabetic mice were more sensitive to ovariectomy (OVX)-induced osteoporosis, and DMF treatment inhibited the sensitivity. OVX-treated diabetic mice exhibited higher TRAP5b and c-terminal telopeptides of type 1 (CTX1) levels, and DMF treatment inhibited the enhancement. DMF reduced RAW 264.7 cell viability. Glucose treatment enhanced the levels of TRAP5b, cathepsin K, Atp6v0d2, and H⁺-ATPase, ROS, while DMF reversed this phenotype. The glucose-increased protein levels were inhibited by DMF in cells treated with RANKL. The expression levels of antioxidant enzymes Gclc, Gclm, Ho-1, and Nqo1 were upregulated by DMF. DMF attenuated high glucose-caused osteoclast differentiation by targeting mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signalling in BMMs.

Conclusion

DMF inhibits high glucose-induced osteoporosis by targeting MAPK and NF-κB signalling.

Cite this article: Bone Joint Res 2022;11(4):200–209.

Pharmacological Properties, Therapeutic Potential and Molecular Mechanisms of JWH133, a CB2 Receptor-Selective Agonist

The endocannabinoid system has attracted attention as a pharmacological target for several pathological conditions. Cannabinoid (CB2)-selective agonists have been the focus of pharmacological studies because modulation of the CB2 receptor (CB2R) can be useful in the treatment of pain, inflammation, arthritis, addiction, and cancer among other possible therapeutic applications while circumventing CNS-related adverse effects. Increasing number of evidences from different independent preclinical studies have suggested new perspectives on the involvement of CB2R signaling in inflammation, infection and immunity, thus play important role in cancer, cardiovascular, renal, hepatic and metabolic diseases. JWH133 is a synthetic agonist with high CB2R selectivity and showed to exert CB2R mediated antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory activities. Cumulative evidences suggest that JWH133 protects against hepatic injury, renal injury, cardiotoxicity, fibrosis, rheumatoid arthritis, and cancer as well as against oxidative damage and inflammation, inhibits fibrosis and apoptosis, and acts as an immunosuppressant. This review provides a comprehensive overview of the polypharmacological properties and therapeutic potential of JWH133. This review also presents molecular mechanism and signaling pathways of JWH133 under various pathological conditions except neurological diseases. Based on the available data, this review proposes the possibilities of developing JWH133 as a promising therapeutic agent; however, further safety and toxicity studies in preclinical studies and clinical trials in humans are warranted.

Gut microbiome and osteoporosis: a review

Osteoporosis (OP) is a chronic metabolic bone disease characterized by the decrease of bone tissue per unit volume under the combined action of genetic and environmental factors, which leads to the decrease of bone strength, makes the bone brittle, and raises the possibility of bone fracture. However, the exact mechanism that determines the progression of OP remains to be underlined. There are hundreds of trillions of symbiotic bacteria living in the human gut, which have a mutually beneficial symbiotic relationship with the human body that helps to maintain human health. With the development of modern high-throughput sequencing (HTS) platforms, there has been growing evidence that the gut microbiome may play an important role in the programming of bone metabolism. In the present review, we discuss the potential mechanisms of the gut microbiome in the development of OP, such as alterations of bone metabolism, bone mineral absorption, and immune regulation. The potential of gut microbiome-targeted strategies in the prevention and treatment of OP was also evaluated.

Cite this article: Bone Joint Res 2020;9(8):524–530.