【Animal modeling】-Effect of aloin on NOX4/ROS/p38 MAPK signaling pathway and podocyte function in diabetic nephropathy rats

  Objective To investigate the effects of aloin on podocyte function and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4)/reactive oxygen species (ROS)/p38 mitogen-activated protein kinase (p38 MAPK) signaling in diabetic nephropathy (DN) rats pathway effects.

  Methods Rats were fed with high-sugar and high-fat diet for 4 weeks, and DN rat model was established by intraperitoneal injection of 40 mg/kg STZ. They were randomly divided into model group, positive control group, and (low, medium and high) dose experimental groups; deal with. The positive control group was given 9.45 mg/(kg·d) Tangshiping by gavage; the (low, medium, and high) doses of the experimental groups were given 10, 20, and 40 mg/(kg·d) aloe verain, and the normal group and the model group were given Equal volume of distilled water in stomach for 6 consecutive weeks. Blood glucose meter was used to detect the level of fasting blood glucose; enzyme-linked immunosorbent assay (ELISA) to detect the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum; HE staining to observe the morphology of rat kidney; superoxide Dismutase (SOD), malondialdehyde (MDA), reactive oxygen species (ROS) kits were used to detect the levels of SOD, MDA and ROS in renal tissue; Western blot was used to detect NOX4, p38 MAPK, phospho-p38 MAPK, renal small Levels of the cleft transmembrane proteins Nephrin and Podocin in podocytes.

  Results Before administration, compared with the normal group, the fasting blood glucose levels in the model group, positive control group, and (low, medium, and high) dose experimental groups increased (P<0.05). After administration, the renal tissue of the model group had hypertrophy of the glomerulus, thickening of the mesangium, thickening of the glomerular basement membrane, and interstitial inflammatory infiltration; Mild-moderate hyperplasia of the mesangium, and slow expansion of renal tubules; in the high-dose experimental group, the shape of renal tissue was normal, the structure was clear, and the shape of glomeruli and tubules were regular. Compared with the normal group, the fasting blood glucose, serum IL-1β, TNF-α, MDA, ROS, NOX4 and phospho-p38 MAPK protein levels in the model group increased (P<0.05), and the levels of SOD, SOD/MDA, Nephrin, Podocin protein levels decreased (P<0.05). Compared with the model group, the fasting blood glucose, serum IL-1β, TNF-α, MDA, ROS, NOX4, phospho-p38 MAPK protein levels in the positive control group and high-dose experimental group were decreased (P<0.05), and renal The SOD level, SOD/MDA, Nephrin and Podocin protein levels in tissue increased (P<0.05); fasting blood glucose, serum IL-1β, TNF-α, MDA, ROS, NOX4 protein levels in kidney tissue decreased in the middle-dose experimental group (P<0.05), SOD levels, SOD/MDA, Nephrin, Podocin protein levels in renal tissue increased (P<0.05); fasting blood glucose, serum IL-1β, TNF-α, MDA in renal tissue in low-dose experimental group , NOX4 protein level decreased (P<0.05); SOD level in kidney tissue increased (P<0.05). Compared with before administration, the fasting blood glucose level in the positive control group and (low, medium and high) dose experimental groups decreased after administration (P<0.05).

  Conclusion Aloin may achieve anti-inflammatory and recovery of podocytes by down-regulating NOX4/ROS/p38 signaling pathway.