High uric acid (UA) downregulates bone alkaline phosphatase (BALP) expression through inhibition of its promoter activity

Fluorescent Determination of Uric Acid Based on Porphyrin and ZnCo2O4 Nanocomposite

Advances in porphyrin chemistry have provided exciting technologies in the field of optical biosensing. Herein, we have synthesized 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and porous Zn0.1Co2O4 nanorods using a simple one-pot hydrothermal method. The obtained TCPP- Zn0.1Co2O4 composite was then used for the development of a novel optical sensor for the determination of uric acid (UA), which is an important biomarker in human urine, serum or saliva for the clinical diagnosis of hyperuricemia and hypouricemia, etc. TCPP-Zn0.1Co2O4 composite was characterized using SEM, TEM, EDAX, PXRD, FT-IR, UV-Visible, and NMR spectroscopic techniques. The fluorescence emission spectral analysis of TCPP-Zn0.1Co2O4 was then investigated for potential applications in the detection of uric acid via the fluorescence quenching mechanism. The designed sensor showed a linear response towards the uric acid in the concentration range of 0.99 to 5.2 nM. The optical sensor exhibits a sensitive response to uric acid with a detection limit of 0.015 nM. The sensor was employed to quantify UA in spiked human urine samples and artificial urine with satisfactory results.

Relationship between serum uric acid levels and osteoporosis

Osteoporosis (OP) is a systemic bone disease in which bone density and quality decrease and bone fragility increases due to a variety of causes, making it prone to fractures. The development of OP is closely related to oxidative stress. Uric acid (UA) is the end product of purine metabolism in the human body. Extracellular UA has antioxidant properties and is thought to have a protective effect on bone metabolism. However, the process of UA degradation can lead to intracellular oxidative stress, which together with UA-induced inflammatory factors, leads to increased bone destruction. In addition, UA can inhibit vitamin D production, resulting in secondary hyperparathyroidism and further exacerbating UA-associated bone loss. This review summarizes the relationship between serum UA levels and bone mineral density, bone turnover markers, and so on, in the hope of providing new insights into the pathogenesis and treatment of OP.

Changes of lipid and bone metabolism in broilers with spontaneous femoral head necrosis

Blood biochemistry and bone metabolism were evaluated to investigate the etiology and mechanism of spontaneous femoral head necrosis (FHN) in broilers. According to the femoral head score of the fourth, fifth, and sixth week old FHN-affected broilers, they were divided into 3 groups, namely Normal group, femoral head separation group, and femoral head separation with growth plate lacerations group, and then carried out a comparative study. The results showed that the liver function (alanine aminotransferase and aspartate aminotransferase) and lipid metabolism (high-density lipoprotein and triglyceride) levels of broilers with spontaneous FHN were significant changed compared with the normal group. At the same time, accumulation of lipid droplets appeared in the liver, which illustrated that the occurrence of FHN may be related to lipid metabolism disorders. Tibia and femur parameters showed significant changes in bone mineral density and bone strength. The distribution of chondrocytes in the articular cartilage of broilers with FHN was irregular and vacuoles appeared, which indicated that cartilage homeostasis was destroyed. TUNEL staining showed that the apoptosis rate of articular chondrocytes in broilers with FHN in 6-week-old was significantly higher than that of normal broilers. Meanwhile, the bone markers (bone glaprotein and bone-specific alkaline phosphatase) changed significantly, indicating that the articular chondrocyte apoptosis and bone metabolism disorder may occur in FHN-affected birds. Therefore, FHN in broilers may be caused by dyslipidemia and abnormal bone metabolism.

Enzymatic determination of uric acid using water-soluble CuInS/ZnS quantum dots as a fluorescent probe

Glutathione-capped water-soluble CuInS/ZnS quantum dots (QDs) were prepared by a microwave-assisted method. Their fluorescence, with excitation/emission peaks at 380/570 nm, is found to be quenched by hydrogen peroxide (H₂O₂) that is produced by the uricase catalyzed oxidation of uric acid (UA) and oxygen. The findings are used in a quenchometric method for the determination of UA. The effects of different ligands on the QDs, of pH value, buffers, enzyme ratio and reaction time were optimized. The detection limit for UA is 50 nM which is lower than other QD-based method, and the detection ranges extends from 0.25-4.0 μM. The assay is simple and sensitive, and no further modification of the QDs is required. Graphical abstract ᅟ.