The influence of ICAM1 rs5498 on diabetes mellitus risk: evidence from a meta-analysis

Mechanism of action of quercetin in regulating cellular autophagy in multiple organs of Goto-Kakizaki rats through the PI3K/Akt/mTOR pathway

Objective

This experimental study investigated the protective function of quercetin on the liver, spleen, and kidneys of Goto-Kakizaki (GK) rats and explores its mechanism of action on autophagy-related factors and pathways.

Materials and methods

GK rats were randomly divided into three groups: DM, DM + L-Que, and DM + H-Que, with age-matched Wistar rats serving as the control group. The control and DM groups were gavaged with saline, and the quercetin-treated group was gavaged with quercetin for 8 weeks each. Weekly blood glucose levels were monitored. Upon conclusion of the experiment, blood samples were gathered for lipid and hepatic and renal function analyses. The histopathologic morphology and lipid deposition in rats were examined. Disease-related targets were identified using molecular docking methods and network pharmacology analysis. Subsequently, immunohistochemical analysis was performed, followed by Western blotting to evaluate the levels of autophagy-related proteins and proteins in the AKT/PI3K/mTOR pathway, as well as their phosphorylation levels.

Results

The results showed that, compared with the control group, the DM group exhibited significant increases in blood glucose, serum liver and kidney markers, liver fat vacuoles, and inflammatory cell infiltration. Immunohistochemistry (IHC) results indicated that quercetin reduced the extensive expression of AKT, P62, and mTOR in the liver and spleen of diabetic rats. The expression of autophagy and pathway-related proteins, such as P62, PI3K, P-PI3K, Akt, P-AKT, mTOR, and P-mTOR, was upregulated, while the expression of LC3A/LC3B, Beclin-1, Pink-1, and Parkin was downregulated. Conversely, the quercetin group showed a reduction in liver and kidney injury serum markers by decreasing lipid deposition and cell necrosis, indicating that quercetin has protective effects on the liver, spleen, and kidneys of GK rats. Additionally, in the quercetin group, the expression of autophagy and pathway-related proteins such as LC3A/LC3B, Beclin-1, Pink-1, and Parkin was upregulated, while the expression of P62, PI3K, P-PI3K, Akt, P-AKT, mTOR, and P-mTOR was downregulated, with statistically significant correlations.

Conclusion

Quercetin markedly ameliorates liver, spleen, and kidney damage in GK rats, potentially through the inhibition of the PI3K/Akt/mTOR pathway, promoting autophagy. This research offers a rationale to the therapeutic potential of quercetin in mitigating organ damage associated with diabetes.

Unveiling the crucial role of intercellular adhesion molecule-1 in secondary diabetic complications

Diabetes mellitus is associated with secondary complications such as diabetic retinopathy (DR), nephropathy (DN), and cardiomyopathy (DCM), all of which significantly impact patient health. Intercellular adhesion molecule-1 (ICAM-1) has been implicated in inflammatory responses and endothelial dysfunction, both crucial in the pathogenesis of these complications. The goal of this review is to investigate at potential therapy methods that target ICAM-1 pathways and to better understand the multifaceted role of ICAM-1 in secondary diabetic problems. A meticulous analysis of scholarly literature published globally was conducted to examine ICAM-1involvement in inflammatory processes, endothelial dysfunction, and oxidative stress related to diabetes and its complications. Elevated ICAM-1 levels are strongly associated with augmented leukocyte adhesion, compromised microvascular function, and heightened oxidative stress in diabetes. These pathways contribute significantly to DR, DN, and DCM pathogenesis, highlighting ICAM-1 as a key player in their progression. Understanding ICAM-1 role in secondary diabetic complications offers insights into novel therapeutic strategies. Targeting ICAM-1 pathways may mitigate inflammation, improve endothelial function, and ultimately attenuate diabetic complications, thereby enhancing patient health outcomes. Continued research in this area is crucial for developing effective targeted therapies.

Divalent Metal Transporter 1 Knock-Down Modulates IL-1β Mediated Pancreatic Beta-Cell Pro-Apoptotic Signaling Pathways through the Autophagic Machinery

Pro-inflammatory cytokines promote cellular iron-import through enhanced divalent metal transporter-1 (DMT1) expression in pancreatic β-cells, consequently cell death. Inhibition of β-cell iron-import by DMT1 silencing protects against apoptosis in animal models of diabetes. However, how alterations of signaling networks contribute to the protective action of DMT1 knock-down is unknown. Here, we performed phosphoproteomics using our sequential enrichment strategy of mRNA, protein, and phosphopeptides, which enabled us to explore the concurrent molecular events in the same set of wildtype and DMT1-silenced β-cells during IL-1β exposure. Our findings reveal new phosphosites in the IL-1β-induced proteins that are clearly reverted by DMT1 silencing towards their steady-state levels. We validated the levels of five novel phosphosites of the potential protective proteins using parallel reaction monitoring. We also confirmed the inactivation of autophagic flux that may be relevant for cell survival induced by DMT1 silencing during IL-1β exposure. Additionally, the potential protective proteins induced by DMT1 silencing were related to insulin secretion that may lead to improving β-cell functions upon exposure to IL-1β. This global profiling has shed light on the signal transduction pathways driving the protection against inflammation-induced cell death in β-cells after DMT1 silencing.

Common and Novel Markers for Measuring Inflammation and Oxidative Stress Ex Vivo in Research and Clinical Practice-Which to Use Regarding Disease Outcomes?

Many chronic conditions such as cancer, chronic obstructive pulmonary disease, type-2 diabetes, obesity, peripheral/coronary artery disease and auto-immune diseases are associated with low-grade inflammation. Closely related to inflammation is oxidative stress (OS), which can be either causal or secondary to inflammation. While a low level of OS is physiological, chronically increased OS is deleterious. Therefore, valid biomarkers of these signalling pathways may enable detection and following progression of OS/inflammation as well as to evaluate treatment efficacy. Such biomarkers should be stable and obtainable through non-invasive methods and their determination should be affordable and easy. The most frequently used inflammatory markers include acute-phase proteins, essentially CRP, serum amyloid A, fibrinogen and procalcitonin, and cytokines, predominantly TNFα, interleukins 1β, 6, 8, 10 and 12 and their receptors and IFNγ. Some cytokines appear to be disease-specific. Conversely, OS-being ubiquitous-and its biomarkers appear less disease or tissue-specific. These include lipid peroxidation products, e.g., F2-isoprostanes and malondialdehyde, DNA breakdown products (e.g., 8-OH-dG), protein adducts (e.g., carbonylated proteins), or antioxidant status. More novel markers include also -omics related ones, as well as non-invasive, questionnaire-based measures, such as the dietary inflammatory-index (DII), but their link to biological responses may be variable. Nevertheless, many of these markers have been clearly related to a number of diseases. However, their use in clinical practice is often limited, due to lacking analytical or clinical validation, or technical challenges. In this review, we strive to highlight frequently employed and useful markers of inflammation-related OS, including novel promising markers.