Proteomic examination of Cornus officinalis stimulated 1.1B4 human pancreatic cells reveals activation of autophagy and Keap1/Nrf2 pathway. (1st November 2022)

• Record Type: Journal Article
• Authors: Sharp-Tawfik, Arielle; Fletcher, Justin D.; Guergues, Jennifer; Marelia-Bennett, Catherine; Wolf, Tiara J.; Coiner, Alexis M.; Zhang, Y. Clare; Stevens, Stanley M.; Burkhardt, Brant R.
• Is Part Of: Molecular and cellular endocrinology. Volume 557(2022)
• Publication Date: 2022-11-01
• Subjects: Type 1 diabetes -- Cornus officinalis -- Proteomics -- Autophagy -- p62 -- Keap1/Nrf2; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2022.111773
• Languages: English
• ISSNs: 0303-7207

Abstract

Abstract: Type 1 diabetes (T1D) is an autoimmune disease initiated by genetic predisposition and environmental influences culminating in the immunologically mediated destruction of pancreatic β-cells with eventual loss of insulin production. Although T1D can be accurately predicted via autoantibodies, therapies are lacking that can intercede autoimmunity and protect pancreatic β-cells. There are no approved interventional modalities established for this purpose. One such potential source for clinical agents of this use is from the frequently utilized Cornus officinalis (CO) in the field of ethnopharmacology. Studies by our lab and others have demonstrated that CO has robust proliferative, metabolic, and cytokine protective effects on pancreatic β-cells. To identify the molecular mechanism of the biological effects of CO, we performed a proteomic and phosphoproteomic analysis examining the cellular networks impacted by CO application on the 1.1B4 pancreatic β-cell line. Our label-free mass spectrometry approach has demonstrated significant increased phosphorylation of the selective autophagy receptor of p62 (Sequestosome-1/SQSTM1/p62) and predicted activation of the antioxidant Kelch-like ECH-associated protein 1 (Keap1)/Nuclear factor-erythroid factor 2-related factor 2 (Nrf2) pathway. Further validation by immunoblotting and immunofluorescence revealed markers of autophagy such as increased LC3-II and decreased total p62 along with nuclear localization of Nrf2. Both autophagy and the Keap1/Nrf2 pathways have been shown to be impaired in human and animal models of T1D and may serve as an excellent potential therapeutic target stimulated by CO. Highlights: The biological impact of C. officinalis on pancreatic β-cells was examined. Proteomics revealed increased phosphorylated p62 and predicted Nrf2 activation. CO induced expression of autophagic markers such as LC3-II. CO promoted Nrf2 translocation to the nucleus and HO-1/SOD-2 expression. CO may promote pancreatic β-cell survival by enhancing autophagy and the Nrf2 cytoprotective pathway.