Protective Effect of Degraded Porphyra yezoensis Polysaccharides on the Oxidative Damage of Renal Epithelial Cells and on the Adhesion and Endocytosis of Nanocalcium Oxalate Crystals

Abstract

The protective effects of Porphyra yezoensis polysaccharides (PYPs) with molecular weights of 576.2 (PYP1), 105.4 (PYP2), 22.47 (PYP3), and 3.89 kDa (PYP4) on the oxidative damage of human kidney proximal tubular epithelial (HK-2) cells and the differences in adherence and endocytosis of HK-2 cells to calcium oxalate monohydrate crystals before and after protection were investigated. Results showed that PYPs can effectively reduce the oxidative damage of oxalic acid to HK-2 cells. Under the preprotection of PYPs, cell viability increased, cell morphology improved, reactive oxygen species levels decreased, mitochondrial membrane potential increased, S phase cell arrest was inhibited, the cell apoptosis rate decreased, phosphatidylserine exposure reduced, the number of crystals adhered to the cell surface reduced, but the ability of cells to endocytose crystals enhanced. The lower the molecular weight, the better the protective effect of PYP. The results in this article indicated that PYPs can reduce the risk of kidney stone formation by protecting renal epithelial cells from oxidative damage and reducing calcium oxalate crystal adhesion, and PYP4 with the lowest molecular weight may be a potential drug for preventing kidney stone formation.

Sea Cucumber Polysaccharide from Stichopus japonicu and Its Photocatalytic Degradation Product Alleviate Acute Alcoholic Liver Injury in Mice

“…Thus, the results indicated that molecular weight affected the oxidative stress activity of sea cucumber polysaccharides. Peng et al [ 38 ] obtained the degradation products of Porphyra yezoensis polysaccharides with different molecular weights through H 2 O 2 degradation and observed the same trend when studying its oxidative stress activation on human renal epithelial cells. Fang et al [ 39 ] found that the enzymatic degradation product of the Gracilariopsis lemaneiformis polysaccharide had a better effect in alleviating oxidative damage in HFL1 cells compared to the original polysaccharide.…”

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress

“…Diminishing crystal adhesion on cell surfaces is an imperative strategy to thwart stone formation [ 64 ]. A prior study from our laboratory [ 65 ] revealed that damaged HK-2 cells, upon repair by polysaccharides, showcased marked reductions in OPN expression.…”

Understanding formation processes of calcareous nephrolithiasis in renal interstitium and tubule lumen

“…93 The process of CaP precipitation in basement membranes involved the following mechanism: The basement membranes of the thin Henle loops are relatively thick and primarily composed of collagens, which along with a substantial presence of mucopolysaccharides, and provide numerous electrostatically binding sites for calcium and phosphate ions. 81 As there was evidence that CaP supersaturation, occurring in the thin Henle loops, adequately induced CaP crystallization, 94 and a few studies have reported the endocytosis of crystals by tubular epithelial cells, [95][96][97] thus there exist arguments that CaP crystals, originating in the tubular lumen, may be endocytosed and exocytosed by cells and then deposit in basement membranes. 77,91,94 Additionally, impaired functions of the tight junction, impairing paracellular permeability and barrier function, may be involved in the translocation of crystals.…”

“…As there was evidence that CaP supersaturation, occurring in the thin Henle loops, adequately induced CaP crystallization, 94 and a few studies have reported the endocytosis of crystals by tubular epithelial cells, 95 , 96 , 97 thus there exist arguments that CaP crystals, originating in the tubular lumen, may be endocytosed and exocytosed by cells and then deposit in basement membranes. 77 , 91 , 94 Additionally, impaired functions of the tight junction, impairing paracellular permeability and barrier function, may be involved in the translocation of crystals.…”