Impact of Sulfated Hyaluronan on Bone Metabolism in Diabetic Charcot Neuroarthropathy and Degenerative Arthritis

Metabolites and Charcot Foot: A Comprehensive Analysis Through Mendelian Randomization

BACKGROUND

Multiple studies have shown metabolites may have potential effects on Charcot foot. However, the Mendelian randomization method has not yet explored the relationship between metabolites and Charcot foot.

METHODS

We selected genetic variants from the publicly available Genome-wide Association Studies (GWAS) summary database to represent 1400 metabolites described in recent research. Mendelian randomization (MR) analysis was carried out to examine the relationships between these metabolites and Charcot foot. Significant single nucleotide polymorphism (SNP) data associated with exposure were screened out through association analysis. Valid instrumental variables (IVs) were then selected, excluding SNPs with F-statistic values below 10. The MR analyses primarily employed the inverse variance weighted (IVW) method. Bayesian weighted Mendelian randomization (BWMR), constrained maximum likelihood(cML), contamination mixture(Conmix), robust adjusted profile score(RAPS), and debiased inverse-variance weighted(deIVW) method were used to enhance the results. Colocalization analysis was performed to identify shared causal genetic variants associated with the resulting phenotypes. Sensitivity analyses, including assessments of Cochrane's Q test, egger intercept, and MR PRESSO test were conducted to confirm the robustness of the results.

RESULTS

After preliminary MR exploration, the IVW results exhibited positive causal relationships between hexadecenedioate (C16:1-DC) levels (OR = 0.698, 95%CI: 0.586 to 0.831, PFDR = 0.040), octadecadienedioate (C18:2-DC) levels (OR = 0.665, 95%CI: 0.552 to 0.800, PFDR = 0.021), octadecanedioylcarnitine (C18-DC) levels (OR = 0.676, 95%CI: 0.553 to 0.827, PFDR = 0.067) and Charcot foot. Colocalization analysis indicated that the above three metabolites share a common causal variant at the same genomic location with Charcot foot. Sixty-four metabolites with suggestive causal relationships with Charcot foot were also identified, among which 25 kinds of metabolites were positively correlated with Charcot foot, and 33 metabolites were negatively associated with Charcot foot. The BWMR, cML, Conmix, RAPS, and deIVW results supported our preliminary MR results. In several results, sensitivity analyses showed heterogeneity and horizontal pleiotropy, while the causal relationships obtained through FDR correction did not show any significant heterogeneity and horizontal pleiotropy. No reverse causal association was detected.

CONCLUSION

We detected protective and risk metabolites in Charcot foot. Controlling metabolites may decrease Charcot foot risk and serve as a novel therapeutic biomarker for the therapy.

Cellular response of advanced triple cultures of human osteocytes, osteoblasts and osteoclasts to high sulfated hyaluronan (sHA3)

Bone remodelling, important for homeostasis and regeneration involves the controlled action of osteoblasts, osteocytes and osteoclasts. The present study established a three-dimensional human in vitro bone model as triple culture with simultaneously differentiating osteocytes and osteoclasts, in the presence of osteoblasts. Since high sulfated hyaluronan (sHA3) was reported as a biomaterial to enhance osteogenesis as well as to dampen osteoclastogenesis, the triple culture was exposed to sHA3 to investigate cellular responses compared to the respective bone cell monocultures. Osteoclast formation and marker expression was stimulated by sHA3 only in triple culture. Osteoprotegerin (OPG) gene expression and protein secretion, but not receptor activator of NF-κB ligand (RANKL) or sclerostin (SOST), were strongly enhanced, suggesting an important role of sHA3 itself in osteoclastogenesis with other targets than indirect modulation of the RANKL/OPG ratio. Furthermore, sHA3 upregulated osteocalcin (BGLAP) in osteocytes and osteoblasts in triple culture, while alkaline phosphatase (ALP) was downregulated.

[Progress in clinical diagnosis and treatment of diabetic Charcot neuroarthropathy of foot and ankle]

Objective

To summarize the progress of clinical diagnosis and treatment of diabetic Charcot neuroarthropathy (CNO) of foot and ankle to provide reference for clinical treatment.

Methods

The research literature on diabetic CNO of foot and ankle at home and abroad was widely reviewed, and the stages and classification criteria of CNO were summarized, and the treatment methods at different stages of the disease course were summarized.

Results

CNO is a rapidly destructive disease of bone and joint caused by peripheral neuropathy, which leads to the formation of local deformities and stress ulcers due to bone and joint destruction and protective sensory loss, which eventually leads to disability and even life-threatening. At present, the modified Eichenholtz stage is a commonly used staging criteria for CNO of foot and ankle, which is divided into 4 stages by clinical and imaging manifestations. The classification mainly adopts the modified Brodsky classification, which is divided into 6 types according to the anatomical structure. The treatment of diabetic CNO of foot and ankle needs to be considered in combination with disease stage, blood glucose, comorbidities, local soft tissue conditions, degree of bone and joint destruction, and whether ulcers and infections are present. Conservative treatment is mainly used in the active phase and surgery in the stable phase.

Conclusion

The formulation of individualized and stepped treatment regimens can help improve the effectiveness of diabetic CNO of foot and ankle. However, there is still a lack of definitive clinical evidence to guide the treatment of active and stable phases, and further research is needed.