Proteomic profiling and correlations with clinical features reveal biomarkers indicative of diabetic retinopathy with diabetic kidney disease.

Diabetic retinopathy (DR) and diabetic kidney disease (DKD) are complications of diabetes and place serious health and economic burdens on society. However, the identification and characterization of early biomarkers for DKD, especially for nonproliferative DR (NPDR) patients with DKD, are still needed. This study aimed to demonstrate the plasma proteomic profiles of NPDR+DKD and NPDR patients and identify potential biomarkers for early diagnosis of DKD. Fifteen plasma samples from the NPDR group and nine from the NPDR+DKD group were analyzed by LC-MS/MS to identify the differentially expressed proteins between the two groups. Functional enrichment, protein-protein interaction and clinical feature correlation analyses revealed the target protein candidates, which were verified using ELISA and receiver operating characteristic (ROC) analysis. In total, 410 proteins were detected in plasma; 15 were significantly upregulated and 7 were downregulated in the NPDR+DKD group. Bioinformatics analysis suggested that DKD is closely related to cell adhesion and immunity pathways. ß-2-Microglobulin (B2M) and vimentin (VIM) were upregulated in NPDR+DKD, enriched as hub proteins and strongly correlated with clinical features. ELISA showed that B2M (p<0.001) and VIM (p<0.0001) were significantly upregulated in NPDR+DKD compared with NPDR. In ROC analysis, B2M and VIM could distinguish DKD from NPDR with area under the curve values of 0.9000 (p < 0.0001) and 0.9950. Our proteomic study revealed alterations in the proteomic profile and identified VIM and B2M as early biomarkers of DKD, laying the foundation for the prevention, diagnosis and treatment of DKD.

Circ-NCX1 inhibits LPS-induced chondrocyte apoptosis by regulating the miR-133a/SIRT1 axis.

Osteoarthritis (OA) is a degenerative joint disease, which is characterized by the degeneration of articular cartilage, thickening of subchondral bone, and inflammation of the synovial membrane. In this study, we aimed to investigate the effects and underlying mechanisms of circ-NCX1 in lipopolysaccharide (LPS)-induced injury in SW1353 chondrocytes, an in vitro model of OA. The levels of circ-NCX1, miR-133a, and related apoptotic proteins were determined by RT-qPCR. MTT assay was used to evaluate the cell viability. The apoptosis was determined by flow cytometry, whereas the expression of apoptosis proteins was detected by Western blot. Immunofluorescence was used to detect cleaved caspase-3 expression in cells. Luciferase reporter assay was used to verify the interaction between circ-NCX1 and miR-133a, and between miR-133a and Silent information regulator 2 homolog 1 (Sirt1). The results showed that the overexpression of circ-NCX1 significantly upregulated the chondrocyte viability and proliferation, and alleviated apoptosis in LPS-induced SW1353 cells. Immunofluorescence results showed that the overexpression of circ-NCX1 significantly reduced expression of LPS-stimulated cleaved Caspase-3. The RT-qPCR results showed that the overexpression of circ-NCX1 inhibited mRNA levels of cleaved Caspase-3 and Bax, and promoted mRNA levels of Bcl-2. Luciferase reporter assay showed that circ-NCX1 targeted miR-133a, and miR-133a directly targeted the Sirt1. In addition, overexpression of circ-NCX1 inhibited chondrocyte apoptosis and promoted Akt phosphorylation via the miR-133a/Sirt1 axis in LPS-induced chondrocytes. In conclusion, circ-NCX1 may serve as an important regulator of LPS-induced chondrocyte apoptosis through the miR-133a/Sirt1 axis, and may be involved in the development of OA.

Downregulation of fatty acid binding protein 4 alleviates lipid peroxidation and oxidative stress in diabetic retinopathy by regulating peroxisome proliferator-activated receptor γ-mediated ferroptosis.

This study aims to explore the role of fatty acid binding protein 4 (FABP4) in diabetic retinopathy (DR), and to elucidate the potential regulatory mechanism. We firstly developed a mouse model of DR by injection with streptozocin (STZ) into C57BL/6 male mice and a cell model of DR by induction of high glucose (HG) to ARPE-19 cells. BMS309403, an inhibitor of FABP4, was employed for treatment. The blood glucose in vivo was monitored and the histological changes of retinal tissues were observed by hematoxylin and eosin staining and Evans blue assay. The expression level of FABP4 was detected by western blot and Immunohistochemical staining. The critical factors related to lipid peroxidation and oxidative stress were detected using their commercial kits, respectively. Prussian blue staining, iron content assay and thiobarbituric acid-reactive substances (TBARS) assay were conducted to evaluate ferroptosis. As a result, FABP4 was elevated in retina and serum of STZ-induced mice and in HG-induced ARPE-19 cells. BMS309403 treatment notably alleviated reduced blood glucose, reduced histological damage, and vascular permeability. In addition, BMS309403 treatment inhibited lipid peroxidation, oxidative stress, and ferroptosis both in vivo and in vitro. Furthermore, BMS309403 promoted the activation of peroxisome proliferator-activated receptor γ (PPARγ). GW9662 (an inhibitor of PPARγ) or Erastin (an inducer of ferroptosis) partially weakened the suppressive effects of BMS309403 on HG-induced lipid peroxidation, oxidative stress and ferroptosis. Taken together, FABP4 inhibition alleviates lipid peroxidation and oxidative stress in DR by regulating PPARγ-mediated ferroptosis.

Profiling of glucosinolates and flavonoids in Rorippa indica (Linn.) Hiern. (Cruciferae) by UHPLC-PDA-ESI/HRMS(n).

An UHPLC-PDA-ESI/HRMS(n) profiling method was used to identify the glucosinolates and flavonoids of Rorippa indica (Cruciferae), a wild vegetable and Chinese herb used to treat cough, diarrhea, and rheumatoid arthritis. Thirty-three glucosinolates, more than 40 flavonol glycosides, and 18 other phenolic and common organic compounds were identified. The glucosinolates and polyphenols were separated by UHPLC. High-resolution deprotonated molecules provided high accuracy mass values that were used to determine formulas and provide putative identification of the glucosinolates and flavonoids. The fragments from multistage mass spectrometry were used to elucidate the structures. The concentrations of the main components were based on UV peak areas and molar relative response factors with a single calibration standard. This study found this plant to be a rich source for glucosinolates, containing 24 new glucosinolates, including 14 glucosylated glucosinolates that were previously unidentified.