Anthocyanin improves kidney function in diabetic kidney disease by regulating amino acid metabolism.

BACKGROUND: Diabetic kidney disease (DKD) is among the most important causes for chronic kidney disease. Anthocyanins (ANT) are polyphenolic compounds present in various food and play an important role in ameliorating hyperglycemia and insulin sensitivity. However, the effects of ANT in DKD are still poorly understood. This study aimed to investigate the effect of ANT (cyanidin-3-O-glucoside [C3G]) on the renal function of DKD, and whether the anti-DKD effect of ANT is related to metabolic pathways. METHODS: To explore the role of ANT in DKD, we performed the examination of blood glucose, renal function, and histopathology. As for the mechanism, we designed the label-free quantification proteomics and nontargeted metabolomics analysis for kidney and serum. Subsequently, we revealed the anti-DKD effect of ANT through the bioinformatic analysis. RESULTS: We showed that the fasting blood glucose level (- 6.1 mmol/L, P = 0.037), perimeter of glomerular lesions (- 24.1 µm, P = 0.030), fibrosis score of glomerular (- 8.8%, P = 0.002), and kidney function (Cystatin C: - 701.4 pg/mL, P = 0.043; urine creatinine: - 701.4 mmol/L, P = 0.032) were significantly alleviated in DKD mice after ANT treatment compared to untreated in the 20th week. Further, proteins and metabolites in the kidneys of DKD mice were observed to be dramatically altered due to changes in amino acid metabolism with ANT treatment; mainly, taurine and hypotaurine metabolism pathway was upregulated (P = 0.0001, t value = 5.97). Furthermore, upregulated tryptophan metabolism (P < 0.0001, t value = 5.94) and tyrosine metabolism (P = 0.0037, t value = 2.91) pathways had effects on serum of DKD mice as responsed ANT regulating. CONCLUSIONS: Our results suggested that prevention of the progression of DKD by ANT could be related to the regulation of amino acid metabolism. The use of dietary ANT may be one of the dietary strategies to prevent and treat DKD.

The role of microbial metabolites in diabetic kidney disease.

Background: Growing evidence suggests a complex bidirectional interaction between gut microbes, gut-derived microbial metabolites, and diabetic kidney disease (DKD), known as the "gut-kidney axis" theory. The present study aimed to characterize the role of microbial metabolites in DKD. Methods: Six-week-old db/db and littermate db/m mice were raised to 20 weeks old. The serum, urine, feces, liver, perinephric fat, and kidney were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based metabolomic analyses. Results: The db/db mice showed obvious pathological changes and worse renal functions than db/m mice. Indoleacetaldehyde (IAld) and 5-hydroxy-l-tryptophan (5-HTP) in kidney samples, and serotonin (5-HT) in fecal samples were increased in the db/db group. Phosphatidylcholine (PC), phosphatidate (PA), and 1-acylglycerophosphocholine (lysoPC) were decreased in liver and serum samples of the db/db group, while PC and lysoPC were decreased in kidney and perinephric fat samples. Suggested metabolomic homeostasis was disrupted in DKD mice, especially glycerophospholipid and tryptophan metabolism, which are closely related to the gut microbiome. Conclusions: Our findings reveal the perturbation of gut microbial metabolism in db/db mice with DKD, which may be useful for building a bridge between the gut microbiota and the progression of DKD and provide a theoretical basis for the intestinal treatment of DKD.

[Percutaneous transforaminal endoscopic foraminoplasty for simple lumbar spinal lateral exit-zone stenosis].

OBJECTIVE: To evaluate the clinical effects of percutaneous endoscopic foraminoplasty for simple lumbar spinal lateral exit zone stenosis. METHODS: A total of 36 patients with simple lumbar spinal lateral exit zone stenosis were admitted to our hospital from January 2013 to June 2018, and received selective nerve root canal radiography and radicular block. According to the symptoms and patients' personal wills, 22 cases underwent the one-stage percutaneous foraminal surgery(the one-stage operation group), and the other 14 patients were re-admitted to the hospital for operation(the delayed operation group) because of the recurrence of symptoms after discharge. The visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical effects before therapy, 1 day after the radicular block, and 1 day, 3 months and 6 months after the operation. RESULTS: VAS and ODI of all 36 cases were obviously improved (P<0.05) at various stages after the surgery and maintained well and showed a continuous downward trend. The VAS at 6 months after the operation was improved significantly compared with that at 1 day after the operation (P<0.05).When comparing the postoperative ODI between 1 day and 3 months after the surgery, 1 day and 6 months after the surgery, 3 months and 6 months after the surgery, the differences were statistically significant (P<0.05). The VAS and ODI of the one-stage operation group at 1 day after radicular block were better than those of delayed operation group. The VAS and ODI of delayed operation group before readmission were significantly higher than those at 1 day after radicular block. There were no significant differences in VAS and ODI at each stage after operation between two groups(P>0.05), but when compared with its own pretherapy andbefore readmission results, the difference was significant (P<0.05). There was no nerve injury in all cases. Only 2 cases were presented with the outlet root stimulation symptoms, and the symptoms relieved after short term conservative treatment. CONCLUSION: The clinical effects of radicular block may be unsustainable for patients with simple lumbar spinal lateral exit zone stenosis. Instead, percutaneous endoscopic foraminoplasty was simple, safe and effective.