Detailed knowledge on tissue-specific metabolic reprogramming in diabetic nephropathy (DN) is vital for more accurate understanding the molecular pathological signature and developing novel therapeutic strategies. In the present study, a spatial-resolved metabolomics approach based on air flow-assisted desorption electrospray ionization (AFADESI) and matrix-assisted laser desorption ionization (MALDI) integrated mass spectrometry imaging (MSI) was proposed to investigate tissue-specific metabolic alterations in the kidneys of high-fat diet-fed and streptozotocin (STZ)-treated DN rats and the therapeutic effect of astragaloside IV, a potential anti-diabetic drug, against DN. As a result, a wide range of functional metabolites including sugars, amino acids, nucleotides and their derivatives, fatty acids, phospholipids, sphingolipids, glycerides, carnitine and its derivatives, vitamins, peptides, and metal ions associated with DN were identified and their unique distribution patterns in the rat kidney were visualized with high chemical specificity and high spatial resolution. These region-specific metabolic disturbances were ameliorated by repeated oral administration of astragaloside IV (100 mg/kg) for 12 weeks. This study provided more comprehensive and detailed information about the tissue-specific metabolic reprogramming and molecular pathological signature in the kidney of diabetic rats. These findings highlighted the promising potential of AFADESI and MALDI integrated MSI based metabolomics approach for application in metabolic kidney diseases.

Understanding of the nephrotoxicity induced by drug candidates is vital to drug discovery and development. Herein, an metabolomics method based on air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) was established for direct analysis of metabolites in renal tissue sections. This method was subsequently applied to investigate spatially resolved metabolic profile changes in rat kidney after the administration of aristolochic acid I, a known nephrotoxic drug, aimed to discover metabolites associated with nephrotoxicity. As a result, 38 metabolites related to the arginine-creatinine metabolic pathway, the urea cycle, the serine synthesis pathway, metabolism of lipids, choline, histamine, lysine, and adenosine triphosphate were significantly changed in the group treated with aristolochic acid I. These metabolites exhibited a unique distribution in rat kidney and a good spatial match with histopathological renal lesions. This study provides new insights into the mechanisms underlying aristolochic acids nephrotoxicity and demonstrates that AFADESI-MSI-based metabolomics is a promising technique for investigation of the molecular mechanism of drug toxicity.

Objective To investigate the mechanism involving the apoptosis of BGC-823 strain induced by miRNA-143. Methods Fluorometry and Western blot were used to detect Bcl-2 mRNA and the protein contents in the gastric cancer strain ( BGC-823)and normal gastric mucosa strain (GES-1).We verified the binding site by a Lnciferase reporter method .MiRNA-143-mimics, in-hibitor and NC were chemically synthesized .Bcl-2 protein levels were measured by Western blotting 48 hours after transiently transfect-ed with either miRNA-143 mimics, inhibitors, or negative control miRNAs into BGC-823 cells.Apoptosis assays were employed to eval-uate cell apoptosis in BGC-823 strain, and miRNA-143 expression levels in BGC-823 were measured by quantitative PCR ( qPCR) sim-ultaneously at different time points after transfection .Results The study successfully predicted and verified the putative miRNA-143 binding site in the 3′UTR of human Bcl-2 gene.Bcl-2 level in BGC-823 cells was significantly increased and miRNA-143 level was de-creased, as compared with that of GES-1 cells, and significant differences could be noted , when comparisons were made between the groups(P<0.01).Research results indicated that miRNA-143-mimics/miRNA-143-inhibitor and the wild type luciferase reporter gene co-transfection significantly reduced and induced the activity of luciferase .Forty-eight hours after transfection , statistical significance could be noticed, when the co-transfection group was compared with the single transfection group (P<0.05).The transfection of miR-NA-143-mimics and miRNA-143-inhibitors had no significant effects on the activity of mutant luciferase reporter gene .Statistical signifi-cance could be seen, when the co-transfection group was compared with the single transfection group (P<0.05).Furthermore, the transfection of miRNA-143-mimics and miRNA-143-inhibitor could significantly inhibit or enhance the expression of Bcl-2 protein, and statistical significance could be found , when it was compared with the control group (P<0.05).miRNA-143-mimics and miRNA-143-inhibitor transfected cells could induce changes in miRNA-143 level.Forty-eight hours after transfection , miRNA-143 level in the miR-NA-143-mimics transfected cells was obviously elevated , while that in the miRNA-143-inhibitor was significantly reduced , and statisti-cal significance could also be noted , when it was compared with the control group (P<0.05).There were no significant differences in miRNA-143 levels, when the negative control group was compared with the transfected control group (P<0.05).Results of apoptosis detection indicated that the elevated expression level of miRNA-143 could significantly induce apoptosis of BGC-823, and statistical sig-nificance could be seen, when the gene intervention group was compared with the transfected control group (P<0.05).Conclusion Through the inhibition of Bcl-2 gene expression, miRNA-143 could induce the apoptosis of the gastric cancer BGC-823 strain.