Three dimensional modeling of biologically relevant fluid shear stress in human renal tubule cells mimics in vivo transcriptional profiles

The kidney proximal tubule is the primary site for solute reabsorption, secretion and where kidney diseases can originate, including drug-induced toxicity. Two-dimensional cell culture systems of the human proximal tubule cells (hPTCs) are often used to study these processes. However, these systems fail to model the interplay between filtrate flow, fluid shear stress (FSS), and functionality essential for understanding renal diseases and drug toxicity. The impact of FSS exposure on gene expression and effects of FSS at differing rates on gene expression in hPTCs has not been thoroughly investigated. Here, we performed RNA-sequencing of human RPTEC/TERT1 cells in a microfluidic chip-based 3D model to determine transcriptomic changes. We measured transcriptional changes following treatment of cells in this device at three different fluidic shear stress. We observed that FSS changes the expression of PTC-specific genes and impacted genes previously associated with renal diseases in genome-wide association studies (GWAS). At a physiological FSS level, we observed cell morphology, enhanced polarization, presence of cilia, and transport functions using albumin reabsorption via endocytosis and efflux transport. Here, we present a dynamic view of hPTCs response to FSS with increasing fluidic shear stress conditions and provide insight into hPTCs cellular function under biologically relevant conditions.

Hematoprotective effects and antioxidant properties of β-glucan and vitamin C against acetaminophen-induced toxicity: an experimental study in rats

Acetaminophen is widely used as an over-the-counter analgesic and antipyretic drug. The aim of the present study was to investigate the pro-oxidative effects of acetaminophen (300 mg/kg/day i.p.) and antioxidative effects of β-glucan (4 mg/kg/day i.p.) and/or vitamin C (100 mg/kg/day i.p.) on the blood parameters of treated rats. After 3 days of treatment, hematological and parameters of redox status were measured. Exposure of rats to acetaminophen caused significant changes in some hematological parameters and the glutathione redox cycle, leading to an increased concentration of oxidative stress parameters and the formation of lipid peroxidation, while the activities of antioxidant enzymes were decreased. Administration of β-glucan and/or vitamin C reduced lipid peroxidation and restored the levels of examined hematological and oxidative stress parameters and improved the activities of antioxidant enzymes. Obtained results demonstrated that acetaminophen has significant pro-oxidative effects and may disrupt redox balance in blood of rats, while the combination of β-glucan and/or vitamin C amplified the antioxidant defense potential and exhibited a strong hematoprotective activity against acetaminophen-induced toxicity. Therefore, β-glucan and vitamin C co-treatment may be a promising therapeutic option for the treatment of acute acetaminophen hematotoxicity.