Hyperurikämie: Wann und wie behandeln?

Effects of a Macroporous Resin Extract of Dendrobium officinale Leaves in Rats with Hyperuricemia Induced by Anthropomorphic Unhealthy Lifestyle

Aim

Hyperuricemia (HUA) has received increased attention in the last few decades due to its global prevalence. Our previous study found that administration of a macroporous resin extract of Dendrobium officinale leaves (DoMRE) to rats with HUA that was induced by exposure to potassium oxazine combined with fructose and a high-purine diet led to a significant reduction in serum uric acid (SUA) levels. The aim of this study was to explore the effects of DoMRE on hyperuricemia induced by anthropomorphic unhealthy lifestyle and to elucidate its possible mechanisms of action.

Methods

Dosages (5.0 and 10.0 g/kg/day) of DoMRE were administered to rats daily after induction of HUA by anthropomorphic unhealthy lifestyle for 12 weeks. The levels of UA in the serum, urine, and feces; the levels of creatinine (Cr) in the serum and urine; and the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum were all measured using an automatic biochemical analyzer. The activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) in the serum, liver, and intestine tissue supernatant were measured using appropriate kits for each biological target. The expressions levels of UA transporters (ABCG2 and GLUT9), tight junction (TJ) proteins (ZO-1 and occludin), and inflammatory factors (IL-6, IL-8, and TNF-α) in the intestine were assayed by immunohistochemical (IHC) staining. Hematoxylin and eosin (H&E) staining was used to assess histological changes in the renal and intestinal tissues.

Results

DoMRE treatment significantly reduced SUA levels and concomitantly increased fecal UA (FUA) levels and the fractional excretion of UA (FEUA) in HUA rats. Furthermore, DoMRE significantly reduced both the XOD activity in the serum, liver, and intestine and the ADA activity in the liver and intestine. DoMRE also effectively regulated the expression of GLUT9 and ABCG2 in the intestine, and it significantly upregulated the expression of the intestinal TJ proteins ZO-1 and occludin. Therefore, DoMRE reduced the damage to the intestinal barrier function caused by the increased production of inflammatory factors due to HUA to ensure normal intestinal UA excretion.

Conclusion

DoMRE demonstrated anti-HUA effects in the HUA rat model induced by an anthropomorphic unhealthy lifestyle, and the molecular mechanism appeared to involve the regulation of urate transport-related transporters (ABCG2 and GLUT9) in the intestine, protection of the intestinal barrier function to promote UA excretion, and inhibition of XOD and ADA activity in the liver and intestine to inhibit UA production in the HUA-induced rats.

Whole transcriptome expression profiles in kidney samples from rats with hyperuricaemic nephropathy

Hyperuricaemic nephropathy (HN) is a common clinical complication of hyperuricaemia (HUA) and poses a huge threat to human health. Hence, we aimed to prospectively investigate the dysregulated genes, pathways and networks involved in HN by performing whole transcriptome sequencing using RNA sequencing. Six kidney samples from HN group (n = 3) and a control group (n = 3) were obtained to conduct RNA sequencing. To disclose the relevant signalling pathways, we conducted the analysis of differentially expressed genes (DEGs), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. A competitive endogenous RNA (ceRNA) network was established to reveal the interactions between lncRNAs, circRNAs, mRNAs and miRNAs and investigate the potential mechanisms of HN. Ultimately, 2250 mRNAs, 306 lncRNAs, 5 circRNAs, and 70 miRNAs were determined to be significantly differentially expressed in the HN group relative to the control group. We further authenticated 8 differentially expressed (DE)-ncRNAs by quantitative real-time polymerase chain reaction, and these findings were in accordance with the sequencing results. The analysis results evidently showed that these DE-ncRNAs were significantly enriched in pathways related to inflammatory reaction. In conclusion, HUA may generate abnormal gene expression changes and regulate signalling pathways in kidney samples. Potentially related genes and pathways involved in HN were identified.

Vitamin C alleviates hyperuricemia nephropathy by reducing inflammation and fibrosis

Hyperuricemia contributes to chronic kidney disease development. However, it has been historically viewed with limited research interest. In this study, we mimicked the development of hyperuricemic nephropathy by using a potassium oxonate-induced hyperuricemia rat model. We found that administering vitamin C at 10 mg/kg/day effectively ameliorated hyperuricemic nephropathy. Compared to the control group, rats with hyperuricemia had significantly increased serum uric acid level, xanthine oxidase activity, and urine microalbumin level, by 5-fold, 1.5-fold, and 4-fold, respectively. At the same time, vitamin C supplementation reverted these values by 20% for serum uric acid level and xanthine oxidase activity and 50% for microalbumin level. Vitamin C also alleviated renal pathology and decreased the expression of pro-inflammatory and pro-fibrotic markers. A further mechanistic study suggested that vitamin C might attenuate hyperuricemic nephropathy in renal tubular epithelial cells induced by monosodium urate (MSU) crystal, at least in part, by directly inhibiting IL-6/JAK2/STAT3 signaling pathway. Meanwhile, in macrophages, vitamin C inhibited the expression of TGF-β, and reduced ROS level induced by MSU by about 35%. In short, our results suggest that vitamin C supplementation delay the progression of hyperuricemic nephropathy.

[Second look: practical diagnostic and therapeutic checks in neurorehabilitation]

Post-acute inpatient neurorehabilitation facilities are increasingly treating patients who are not only severely ill and multimorbid but who are also referred from non-neurological departments. These patients are still often medically unstable so that the previous diagnostics and treatment must be reevaluated and when necessary adapted or supplemented. Certain interdisciplinary diagnostic and therapeutic problems, such as antithrombotic therapy, regularly reoccur. This article presents these problems in a checklist fashion, which should provide indications in individual cases when previously carried out measures need to be questioned and adapted.