Whey Improves In Vitro Endothelial Mitochondrial Function and Metabolic Redox Status in Diabetic State

Abstract

Endothelial dysfunction plays a critical role in the progression of type 2 diabetes mellitus (T2DM), leading to cardiovascular complications. Current preventive antioxidant strategies to reduce oxidative stress and improve mitochondrial function in T2DM highlight dietary interventions as a promising approach, stimulating the deepening of knowledge of food sources rich in bioactive components. Whey (WH), a dairy by-product with a considerable content of bioactive compounds (betaines and acylcarnitines), modulates cancer cell metabolism by acting on mitochondrial energy metabolism. Here, we aimed at covering the lack of knowledge on the possible effect of WH on the mitochondrial function in T2DM. The results showed that WH improved human endothelial cell (TeloHAEC) function during the in vitro diabetic condition mimicked by treating cells with palmitic acid (PA) (0.1 mM) and high glucose (HG) (30 mM). Of note, WH protected endothelial cells from PA+HG-induced cytotoxicity (p < 0.01) and prevented cell cycle arrest, apoptotic cell death, redox imbalance, and metabolic alteration (p < 0.01). Moreover, WH counteracted mitochondrial injury and restored SIRT3 levels (p < 0.01). The SiRNA-mediated suppression of SIRT3 abolished the protective effects exerted by WH on the mitochondrial and metabolic impairment caused by PA+HG. These in vitro results reveal the efficacy of whey as a redox and metabolic modulator in the diabetic state and pave the way for future studies to consider whey as the source of dietary bioactive molecules with health benefits in preventive strategies against chronic diseases.

SGLT2 inhibitor promotes mitochondrial dysfunction and ER-phagy in colorectal cancer cells

“…We found that iSGLT2 promoted lysosome accumulation and autophagy cell death via LC3B activation in CRC cells and along with ER stress induction and upregulation of the molecular players related to autophagy triggered by ER stress, namely ER-phagy, i.e., PERK, CHOP and ATF6 [ 45 , 67 , 68 ]. Several reports described the ER stress-mediated autophagy-associated cell death as antitumor strategies in CRC [ 39 , 69 – 71 ]. However, to date no studies explored the association between SGLT2 and ER stress/autophagy as antineoplastic tool in CRC.…”

“…Metabolic state was investigated by using Glucose Assay Kit-WST (Dojindo Molecular Technologies, Tokyo, Japan), Lactate Assay Kit-WST (Dojindo, Molecular Technologies, Tokyo, Japan), NAD/NADH Assay Kit-WST (Dojindo Molecular Technologies, Tokyo, Japan), GSSG/GSH quantification kit (Dojindo Molecular Technologies, Tokyo, Japan), and ATP kit (Abcam, Cambridge, UK), according to the supplier’s instructions and as already described [ 38 , 39 ]. Specific absorbances were measured with a microplate reader model 680 (Bio-Rad, Hercules, CA, USA).…”

“…Respiration assay was assessed with the Seahorse MitoStress kit (Agilent Technologies, Santa Clara, CA, USA), as already described [ 39 ]. Cells were seeded in Seahorse assay microplate in growth medium or treatment.…”

“…RNA isolation and quantitative RT-PCR were performed, as already reported [ 39 ], to detect SGLT2 and SIRT3 mRNA levels. The relative sirtuin and SGLT2 expression levels were determined by comparing the expression of SIRT3 or SGLT2 to that of GAPDH with the 2 −ΔΔCt method, using the primer sequences reported in Table S1.…”

“…Acidic lysosomes and autophagy were detected by LysoTracker Red DND-99 (Invitrogen, Waltham, MA, USA) and Autophagy assay kit (Abcam, Cambridge, UK), respectively. As previously described [ 39 , 42 ], cells were incubated at 37 °C for 30 min in the dark with 1 µM LysoTracker or 2 μL green reagent and 1 μL nuclear stain. The occurrence of ER stress was assessed by staining cells for 30 min with 1 µM ER-Tracker Blue-White DPX dye (Invitrogen, Waltham, MA, USA).…”