Project description:Chronic kidney disease (CKD) results in the impaired filtration of metabolites, which may be toxic or harmful to organs/tissues. The objective of this study was to perform unbiased 1H nuclear magnetic resonance (NMR)-based metabolomics profiling of tissues from mice with CKD. Five-month-old male C57BL6J mice were placed on either a casein control diet or adenine-supplemented diet to induce CKD for 24 weeks. CKD was confirmed by significant increases in blood urea nitrogen (24.1 ± 7.7 vs. 105.3 ± 18.3 mg/dL, p < 0.0001) in adenine-fed mice. Following this chronic adenine diet, the kidney, heart, liver, and quadriceps muscles were rapidly dissected; snap-frozen in liquid nitrogen; and the metabolites were extracted. Metabolomic profiling coupled with multivariate analyses confirm clear separation in both aqueous and organic phases between control and CKD mice. Severe energetic stress and apparent impaired mitochondrial metabolism were observed in CKD kidneys evidenced by the depletion of ATP and NAD+, along with significant alterations in tricarboxylic acid (TCA) cycle intermediates. Altered amino acid metabolism was observed in all tissues, although significant differences in specific amino acids varied across tissue types. Taken together, this study provides a metabolomics fingerprint of multiple tissues from mice with and without severe CKD induced by chronic adenine feeding.
Project description:BackgroundEctopic calcification (EC) involves multiple organ systems in chronic kidney disease (CKD). Previous CKD-animal models primarily focused on a certain histological abnormality but did not show the correlation with calcified development among various tissues. This study compared calcified deposition in various tissues during CKD progression in mice.MethodsMale 8-week-old C57BL/6J mice were randomly allocated to the seven groups: a basic, adenine, high-phosphorus, or adenine and high-phosphorus diet for 12-16 weeks (Ctl16, A12, P16, or AP16, respectively); an adenine diet for 4-6 weeks; and a high-phosphorus or adenine and high-phosphorus diet for 10-12 weeks (A6 + P10, A4 + P12, or A4 + AP12, respectively).ResultsCompared to the Ctl16 mice, the P16 mice only displayed a slight abnormality in serum calcium and phosphorus; the A12 mice had the most serious kidney impairment; the A4 + P12 and A6 + P10 mice had similar conditions of CKD, mineral abnormalities, and mild calcification in the kidney and aortic valves; the A4 + AP12 and AP16 groups had severe kidney impairment, mineral abnormalities and calcification in the kidneys, aortic valves and aortas. Furthermore, calcium-phosphate particles were deposited not only in the tubulointerstitial compartment but in the glomerular and tubular basement membrane. The elemental composition of EC in various tissues matched the calcification of human cardiovascular tissue as determined by energy dispersive spectroscopy.ConclusionsThe severity of CKD was unparalleled with the progression of mineral metabolism disorder and EC. Calcification was closely related in different tissues and observed in the glomerular and tubular basement membranes.
Project description:Chronic kidney disease (CKD) causes anemia by renal damage. In CKD, the kidney is submitted to hypoxia, persistent inflammation, leading to fibrosis and permanent loss of renal function. Human recombinant erythropoietin (rEPO) has been widely used to treat CKD-associated anemia and is known to possess organ-protective properties that are independent from its well-established hematopoietic effects. Nonhematopoietic effects of EPO are mediated by an alternative receptor that is proposed to consist of a heterocomplex between the erythropoietin receptor (EPOR) and the beta common receptor (βcR). The present study explored the effects of rEPO to prevent renal fibrosis in adenine-induced chronic kidney disease (Ad-CKD) and their association with the expression of the heterodimer EPOR/βcR. Male Wistar rats were randomized to control group (CTL), adenine-fed rats (Ad-CKD), and Ad-CKD with treatment of rEPO (1050 IU/kg, once weekly for 4 weeks). Ad-CKD rats exhibited anemia, uremia, decreased renal function, increased infiltration of inflammatory cells, tubular atrophy, and fibrosis. rEPO treatment not only corrected anemia but reduced uremia and partially improved renal function as well. In addition, we observed that rEPO diminishes tubular injury, prevents fibrosis deposition, and induces the EPOR/βcR heteroreceptor. The findings may explain the extrahematopoietic effects of rEPO in CKD and provide new strategies for the treatment of renal fibrosis in CKD.
Project description:AimCerium oxide, particularly in nanoparticle form (nanoceria), has been investigated for biomedical applications as a promising new agent for treating several pathologies. The aim of the present study was to characterize the pharmacologic effects of nanoceria in an animal model of chronic kidney disease.MethodsWe created the chronic kidney disease animal model by feeding rats a 0.25% adenine diet. Male Wistar rats were divided into five groups: normal diet, 0.25% adenine diet, or adenine diet containing three different doses or durations of nanoceria treatment. Blood was collected weekly from the tail veins of each rat and analyzed for renal function markers. After 5 weeks, various biochemical markers in serum, plasma, and urine were also analyzed.ResultsIn the adenine-treated group, body weight was significantly decreased, and the kidneys lost much of their healthy reddish color and became lumpy and white in appearance. In addition, levels of serum creatinine, blood urea nitrogen, and plasma uremic toxins were significantly increased in adenine-treated rats compared with controls. Renal functional and structural damage in adenine diet model rats tended to be ameliorated by nanoceria ingestion. The high-dose cerium-treated group maintained reddish areas in the kidneys, and the increases in biomarker levels of creatinine, blood urea nitrogen, and inorganic phosphorus were markedly reduced, regardless of treatment duration.ConclusionsIngestion of nanoceria may be effective for improving or preventing renal damage caused by adenine. Geriatr Gerontol Int 2024; 24: 88-95.
Project description:Chronic kidney disease (CKD) is a leading public health problem with high morbidity and mortality. However, the therapies remain limited. Traditional Chinese medicine (TCM) has been used for treating kidney disease for thousands of years and is an effective alternative treatment for CKD patients in China and other Asian countries. In the present study, we aimed to investigate the effect and mechanism of Huangqi-Danshen decoction (HDD), a TCM herbal decoction, on treating CKD. CKD rat model was induced by adding 0.75% adenine to the diet for 4 weeks. HDD extract was administrated orally to CKD rats at the dose of 4.7 g/kg/d for consecutive 4 weeks in adenine-induced CKD rats. Kidney function was evaluated by the levels of serum creatinine (Scr) and blood urea nitrogen (BUN). The pathological changes of kidney tissues were observed by periodic acid-Schiff (PAS) and Masson's trichrome staining. The proteins expression of renal fibrosis and mitochondrial dynamics were determined and quantified by Western blot analysis. CKD rats showed obvious decline in renal function as evidenced by increased levels of Scr and BUN, which were blunted by HDD treatment. HDD could also improve tubular atrophy and interstitial fibrosis of CKD rats. Moreover, HDD downregulated fibronectin, type IV collagen, and α-smooth muscle actin expression in CKD rats. Furthermore, mitochondrial dynamics was disturbed in CKD rats, which manifested as increased mitochondrial fission and decreased mitochondrial fusion. HDD treatment restored mitochondrial dynamics in CKD rats by repressing dynamin-related protein 1 and Mid 49/51 expression, promoting mitofusin 2 expression, and suppressing optic atrophy 1 proteolysis. In conclusion, HDD could significantly retard CKD progression through modulating mitochondrial dynamics.
Project description:To date, good experimental animal models of renal anemia are not available. Therefore, the purpose of this study was to establish a novel approach to induce chronic kidney disease (CKD) with severe anemia by oral administration of adenine in rodents. Adenine was administered to 6-week-old male C57BL/6 mice (25 and 50 mg/kg body weight) by oral gavage daily for 28 days. Serum creatinine and BUN as well as hematocrit, hemoglobin (Hb) and plasma erythropoietin (EPO) levels were monitored to assess renal function and anemia, respectively. Adenine at 25 mg/kg for 28 days slightly increased plasma creatinine levels, but did not induce anemia. In contrast, 50 mg/kg of adenine daily for 28 days showed severe renal dysfunction (plasma creatinine 1.9 ± 0.10 mg/dL) and anemia (hematocrit 36.5 ± 1.0% and EPO 28 ± 2.4 pg/mL) as compared with vehicle-treated mice (0.4 ± 0.02 mg/dL, 49.6 ± 1.6% and 61 ± 4.0 pg/mL, respectively). At the end of experiment, level of Hb also significantly reduced in 50 mg/kg adenine administration group. Remarkable histological changes of kidney tissues characterized by interstitial fibrosis and cystic appearance in tubules were observed in 50 mg/kg of adenine treatment group. These results have demonstrated that oral dosing with adenine at 50 mg/kg for 28 days is suitable to induce a stable anemia associated with CKD in mice.