Comprehensive expression analysis of mRNA and microRNA for the investigation of compensatory mechanisms in the rat kidney after unilateral nephrectomy

The transcriptome of early compensatory kidney growth reveals cell and time specific responses

Following kidney removal, the remaining kidney enlarges and increases its function. The mechanism and signals driving this compensatory kidney hypertrophy and the enlargement of its constituent kidney cells remains elusive. RNA-seq studies in mice undergoing hypertrophy 24, 48, and 72 h following nephrectomy were undertaken to understand the early transcriptional changes. This revealed substantial enhancement of cholesterol biosynthesis pathways, increases in mitochondrial gene expression and cell cycle perturbations. Single nuclei RNA-seq delineated cell specific changes at 24 h post nephrectomy and showed that sterol binding protein 2 (SREBP2) activity increases in medullary thick ascending limb cells in keeping with promotion of cholesterol synthesis. Cultured renal tubular cells were examined for insulin-like growth factor-1 (IGF-1) stimulated hypertrophy and SREBP2 was found to be required for increase in cell size. This work describes the early cell specific growth pathways mediating cellular and kidney hypertrophy with an intriguing role for cholesterol synthesis.

Nuclear miR-150 enhances hepatic lipid accumulation by targeting RNA transcripts overlapping the PLIN2 promoter

Alcohol-associated liver disease is a prevalent chronic liver disease caused by excessive ethanol consumption. This study aims to investigate the role of miR-150 in regulating hepatic lipid homeostasis in alcoholic fatty liver (AFL). miR-150 was mainly distributed in the nucleus of hepatocytes and correlated with the degree of liver injury. The decreased expression of miR-150 observed in AFL was a compensatory response to ethanol-induced hepatic steatosis. Overexpression of miR-150 facilitated hepatic lipid accumulation in cellulo and exacerbated ethanol-induced liver steatosis in vivo. In silico analysis identified perilipin-2 (PLIN2) as a potential target gene of miR-150. miR-150 activated PLIN2 transcription by directly binding the RNA transcripts overlapping PLIN2 promoter and facilitating the recruitment of DNA helicase DHX9 and RNA polymeraseⅡ. Overall, our study provides fresh insights into the homeostasis regulation of hepatic steatosis induced by ethanol and identifies miR-150 as a pro-steatosis effector driving transcriptional PLIN2 gene activation.

A Rodent Model of Human-Dose-Equivalent 5-Fluorouracil: Toxicity in the Liver, Kidneys, and Lungs

5-Fluorouracil (5-FU) is a chemotherapy drug widely used to treat a range of cancer types, despite the recurrence of adverse reactions. Therefore, information on its side effects when administered at a clinically recommended dose is relevant. On this basis, we examined the effects of the 5-FU clinical treatment on the integrity of the liver, kidneys, and lungs of rats. For this purpose, 14 male Wistar rats were divided into treated and control groups and 5-FU was administered at 15 mg/kg (4 consecutive days), 6 mg/kg (4 alternate days), and 15 mg/kg on the 14th day. On the 15th day, blood, liver, kidney, and lung samples were collected for histological, oxidative stress, and inflammatory evaluations. We observed a reduction in the antioxidant markers and an increase in lipid hydroperoxides (LOOH) in the liver of treated animals. We also detected elevated levels of inflammatory markers, histological lesions, apoptotic cells, and aspartate aminotransferase. Clinical treatment with 5-FU did not promote inflammatory or oxidative alterations in the kidney samples; however, histological and biochemical changes were observed, including increased serum urea and uric acid. 5-FU reduces endogenous antioxidant defenses and increases LOOH levels in the lungs, suggesting oxidative stress. Inflammation and histopathological alterations were also detected. The clinical protocol of 5-FU promotes toxicity in the liver, kidneys, and lungs of healthy rats, resulting in different levels of histological and biochemical alterations. These results will be useful in the search for new adjuvants to attenuate the adverse effects of 5-FU in such organs.

Decellularization of kidney tissue: comparison of sodium lauryl ether sulfate and sodium dodecyl sulfate for allotransplantation in rat

An automatic decellularization device was developed to perfuse and decellularize male rats' kidneys using both sodium lauryl ether sulfate (SLES) and sodium dodecyl sulfate (SDS) and to compare their efficacy in kidney decellularization and post-transplantation angiogenesis. Kidneys were perfused with either 1% SDS solution for 4 h or 1% SLES solution for 6 h. The decellularized scaffolds were stained with hematoxylin and eosin, periodic acid Schiff, Masson's trichrome, and Alcian blue to determine cell removal and glycogen, collagen, and glycosaminoglycan contents, respectively. Moreover, scanning electron microscopy was performed to evaluate the cell removal and preservation of microarchitecture of both SDS and SLES scaffolds. Additionally, DNA quantification assay was applied for all groups in order to measure residual DNA in the scaffolds and normal kidney. In order to demonstrate biocompatibility of the decellularized scaffolds, human umbilical cord mesenchymal stromal/stem cells (hUC-MSCs) were seeded on the scaffolds. In addition, the allotransplantation was performed in back muscle and angiogenesis was evaluated. Complete cell removal in both SLES and SDS groups was observed in scanning electron microscopy and DNA quantification assays. Moreover, the extracellular matrix (ECM) architecture of rat kidney in the SLES group was significantly preserved better than the SDS group. The hUC-MSCs were successfully migrated from the cell culture plate surface into the SDS and SLES decellularized scaffolds. The formation of blood vessels was observed in the kidney in both SLES and SDS decellularized kidneys. The better preservation of ECM than SDS introduces SLES as the solvent of choice for kidney decellularization.

In vivo mutagenicity and tumor-promoting activity of 1,3-dichloro-2-propanol in the liver and kidneys of gpt delta rats

1,3-Dichloro-2-propanol (1,3-DCP), a food contaminant, exerts carcinogenic effects in multiple organs, including the liver and kidneys, in rats. However, the underlying mechanisms of 1,3-DCP-induced carcinogenesis remain unclear. Here, the in vivo mutagenicity and tumor-promoting activity of 1,3-DCP in the liver and kidneys were evaluated using medium-term gpt delta rat models previously established in our laboratory (GPG and GNP models). Six-week-old male F344 gpt delta rats were treated with 0 or 50 mg/kg body weight/day 1,3-DCP by gavage for 4 weeks. After 2 weeks of cessation, partial hepatectomy or unilateral nephrectomy was performed to collect samples for in vivo mutation assays, followed by single administration of diethylnitrosamine (DEN) for tumor initiation. One week after DEN injection, 1,3-DCP treatment was resumed, and tumor-promoting activity was evaluated in the residual liver or kidneys by histopathological analysis of preneoplastic lesions. gpt mutant frequencies increased in excised liver and kidney tissues following 1,3-DCP treatment. 1,3-DCP did not affect the development of glutathione S-transferase placental form-positive foci in residual liver tissues, but enhanced atypical tubule hyperplasia in residual kidney tissues. Detailed histopathological analyses revealed glomerular injury and increased cell proliferation of renal tubular cells in residual kidney tissues of rats treated with 1,3-DCP. These results suggested possible involvement of genotoxic mechanisms in 1,3-DCP-induced carcinogenesis in the liver and kidneys. In addition, we found that 1,3-DCP exhibited limited tumor-promoting activity in the liver, but enhanced clonal expansion in renal carcinogenesis via proliferation of renal tubular cells following glomerular injury.