NRF2-HIF2α Signaling Attenuates Endothelial Cell Senescence and Maintains Intercellular Junctions in Diabetes.

In the context of diabetes, endothelial cells frequently exhibit compromised intercellular junctions and accelerated cellular senescence simultaneously. The precise mechanisms underlying these issues and the identification of effective treatments remain largely undefined. Our findings reveal that human umbilical vein endothelial cells (HUVECs) can counteract senescence and uphold the integrity of intercellular junctions under mildly to moderately elevated glucose levels (10 mM and 15 mM) via two primary mechanisms: i) The acetylation of NRF2 at lysine residues K56, K68, and K52 prevents its ubiquitination, enhancing the transcription of antioxidant genes GST, SOD1, and GPX1. This activity diminishes cytoplasmic oxidative stress, thereby mitigating endothelial cell senescence. ii) The interaction between the Neh2 domain of NRF2 and the PAS-B domain of HIF-2α within the nucleus curtails the attachment of HIF-2α to the NOX4/p22phox promoter. This action lessens oxidative stress near the cell membrane, maintaining intercellular junctions by safeguarding the disulfide bonds in occludin and E-cadherin from disruption. However, these protective strategies prove insufficient under severe hyperglycemic conditions (25 mM). Further investigation has identified Oltipraz, an activator of NRF2, as also promoting the degradation of HIF-2α. Through its simultaneous modulation of NRF2 and HIF-2α, Oltipraz significantly reduces cellular senescence and prevents the deterioration of intercellular junctions in HUVECs subjected to high glucose concentrations (25 mM). Our research positions Oltipraz as a promising therapeutic candidate for mitigating diabetes-induced vascular endothelial damage, potentially offering benefits against diabetes-related atherosclerosis and valvular calcification.

Network pharmacology combined with an experimental validation study to reveal the effect and mechanism of Lonicera japonica Thunb. extracts against immunomodulation.

Lonicera japonica Thunb. (LJT) is known for its valuable medicinal properties that highlight its potential application in the pharmaceutical and health food industry. We predict that LJT polyphenols by network pharmacology may be involved in immunomodulation, and the study of LJT polyphenols regulating immunity is still insufficient; therefore, we experimentally found that LJT enhances immunity by promoting the proliferation and phagocytic activity of RAW246.7 cells. A model of an immunosuppressed mouse was constructed using cyclophosphamide-induced, and LJT was extracted for the intervention. We found that LJT restored immune homeostasis in immune deficiency mice by inhibiting the abnormal apoptosis in lymphocytes, enhancing natural killer cell cytotoxicity, promoting T lymphocyte proliferation, and increasing the CD4+ and CD8+ T lymphocytes in quantity. Moreover, LJT treatment modulates immunity by significantly downregulating lipopolysaccharide-induced inflammation and oxidative stress levels. We verified the immunomodulatory function of LJT through both cell and animal experiments. The combination of potential-protein interactions and molecular docking later revealed that LJT polyphenols were associated with immunomodulatory effects on MAPK1; together, LJT intervention significantly modulates the immune, with the activation of MAPK1 as the underlying mechanism of action, which provided evidence for the utilization of LJT as a nutraceutical in immune function.

Significant association of serum autoantibodies to TYMS, HAPLN1 and IGFBP5 with early stage canine malignant mammary tumours.

Canine mammary tumours (CMTs) are the most prevalent neoplasms in female dogs. Despite the high incidence of such tumours, a lack of easily accessible biomarkers still impedes early diagnosis of malignant CMTs. Herein we identify thymidylate synthetase (TYMS), hyaluronan and proteoglycan link protein 1 (HAPLN1) and insulin-like growth factor-binding protein 5 (IGFBP5) as CMT antigens eliciting corresponding autoantibodies in CMT cases. We establish enzyme-linked immunosorbent assays (ELISAs) to detect autoantibodies to TYMS (TYMS-AAb), HAPLN1 (HAPLN1-AAb) and IGFBP5 (IGFBP5-AAb) in sera from 81 dogs with malignant CMTs (41 in Stage I), 24 with benign CMTs and 35 healthy controls. Levels of all the three autoantibodies are elevated in the malignant group compared with the healthy or the benign group; notably, the elevated autoantibody levels significantly correlate with the stage-I CMTs. For discriminating malignant CMTs from healthy control, the area under curve (AUC) of TYMS-AAb is 0.694 with specificity of 82.9% and sensitivity of 50.6%. The AUC of utilising HAPLN1-AAb for distinguishing the stage-I CMTs from healthy controls is 0.711 with specificity of 77.1% and sensitivity of 58.5%. In differentiating malignant CMTs from the benign, the AUC of IGFBP5-AAb reaches 0.696 with specificity of 70.8% and sensitivity of 67.9%, and a combination of IGFBP5-AAb and TYMS-AAb increases the AUC to 0.72. Finally, the AUC of combined HAPLN1-AAb and IGFBP5-AAb in discriminating the stage-I CMTs from the benign achieves 0.731. Collectively, this study highlights a significant association of the three serum autoantibodies with early stage malignant CMTs.