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Purpose: In our previous study, exacerbation of albuminuria was observed in A1 adenosine receptor knockout (A1AR) mice with diabetic nephropathy (DN), but the mechanism was unclear. Here, we investigated the relationship of megalin loss and albuminuria, to identify the protective effect of A1AR in megalin loss associated albuminuria by inhibiting pyroptosis-related caspase-1/IL-18 signaling of DN.
Methods: We successfully collected DN patients' samples and built diabetes mice models induced by streptozotocin. Megalin, cubilin, and A1AR expression were detected in kidney tissue samples from DN patients and mice through immunohistochemical and immunofluorescent staining. A1AR, caspase-1, interleukin-18 (IL-18) expression were analyzed using Western blotting in wild-type and mice. Human renal proximal tubular epithelial cells (PTC) were cultured with high glucose to observe the effect of A1AR agonist and antagonist on caspase-1/IL-18 and megalin injury.
Results: The loss of megalin, co-localized with A1AR at PTC, was associated with the level of albuminuria in diabetic patients and mice. The injury of megalin-cubilin was accompanied with the A1AR upregulation (1.30±0.1 vs 0.98±0.2, 0.042), the caspase-1 (1.33±0.1 vs 1.0±0.2, 0.036), and IL-18 (1.26±0.2 vs 0.96±0.2, 0.026) signaling activation in mice with DN. More severe pathological injury, 24 hrs urine albumin excretion (170.8±4.1 μg/d vs 132.0±2.9 μg/d vs 17.9±2.8 μg/d, 0.001) and megalin-cubilin loss were observed in DN mice with more pronounced caspase-1 (1.52±0.03 vs 1.20±0.01, 0.017) and IL-18 (1.42±0.02 vs 1.21±0.02, 0.018) secretion. High glucose could stimulate the secretion of caspase-1 (1.72 times, 0.01) and IL-18 (1.64 times, 0.01), which was abolished by A1AR agonist and aggravated by A1AR antagonist.
Conclusion: A1AR played a protective role in proximal tubular megalin loss associated albuminuria by inhibiting the pyroptosis-related caspase-1/IL-18 signaling in DN.
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http://dx.doi.org/10.2147/DMSO.S215531 | DOI Listing |
JCI Insight
August 2025
Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Paris F-75006, France.
High myopia (HM) and posterior staphyloma (PS) are major causes of vision loss worldwide. Genetic and environmental factors, especially light exposure, influence myopia. This study shows that low-density lipoprotein-related receptor type 2 (LRP2) levels are decreased in the vitreous of patients with HM and PS, and that in human donor eyes affected by PS, LRP2 expression was reduced in the neural retina and retinal pigment epithelium (RPE), with morphologic changes similar to those observed in the Foxg1-Cre-Lrp2fl/fl mouse that also develops PS.
View Article and Find Full Text PDFCell Rep
July 2025
Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210000, China; Department of Neurology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, China. Electronic address:
Secondary demyelination worsens outcomes after cerebral infarction, but astrocyte-oligodendrocyte interactions in this process remain unclear. Using distal middle cerebral artery occlusion (dMCAO) in mice, we show that lipocalin-2 (LCN2), partially diffusing from the infarct-adjacent corpus callosum, is transcriptionally and translationally upregulated in reactive astrocytes of the contralateral corpus callosum by 7 days post-injury. At upstream levels, PERK-orchestrated endoplasmic reticulum stress drives contralateral astrocytic activation and autonomous LCN2 synthesis.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Cell Res
August 2025
Department of Nephrology, The Second Affiliated Hospital of Harbin Medical University, 150086 Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, 150086 Harbin, China. Electronic address:
Cisplatin-induced acute kidney injury (AKI) is associated with a considerable risk of mortality, highlighting the critical need for effective preventive and therapeutic strategies to mitigate its impact on patients' outcomes. Mounting evidence suggests that administration of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor evolocumab significantly reduces the risk of AKI, however, the underlying mechanisms remain poorly understood. Megalin is an endocytic receptor that plays a crucial role in tubular cells.
View Article and Find Full Text PDFJ Am Soc Nephrol
April 2025
Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
Background: Loss-of-function mutations in the lysosomal channel transient receptor potential cation channel (TRPML-1) cause mucolipidosis type IV (MLIV), a rare lysosomal storage disease characterized by neurological defects, progressive vision loss, and achlorhydria. Recent reports have highlighted kidney disease and kidney failure in patients with MLIV during the second to third decade of life; however, the molecular mechanisms driving kidney dysfunction remain poorly understood.
Methods: A cross-sectional review of medical records from 21 patients with MLIV (ages 3–43 years) was conducted to assess kidney function impairment.
Pediatr Nephrol
March 2025
Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan.
The proximal tubule has a highly efficient endocytic pathway dedicated to reabsorbing albumin and low-molecular-weight proteins that have passed through the glomerular filtration barrier. This pathway is dependent on multi-ligand receptors: megalin and cubilin. Abnormalities in genes associated with endocytosis in the proximal tubule can lead to tubular proteinuria, where the urine contains albumin and low-molecular-weight proteins.
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