bioRxiv ScienceSearch

bioRxiv · 10.1101/2020.01.07.897751

Nephrotic Syndrome-Associated Hypercoagulopathy is Alleviated by Nuclear Receptor Agonist Therapy with both Pioglitazone and Glucocorticoids

Abstract

BackgroundThrombosis is a potentially life-threatening nephrotic syndrome (NS) complication. We have previously demonstrated that hypercoagulopathy is proportional to NS severity in rat models and that pioglitazone (Pio) reduces proteinuria both independently and in combination with methylprednisolone (MP), a glucocorticoid (GC). However, the effect of these treatments on NS-associated hypercoagulopathy remains unknown. We thus sought to determine the ability of Pio and GC to alleviate NS-associated hypercoagulopathy. MethodsPuromycin aminonucleoside-induced rat NS was treated with sham, Low- or High-dose MP, Pio, or combination (Pio+Low-MP) and plasma was collected at day 11. Plasma samples were collected from children with steroid-sensitive NS (SSNS) and steroid-resistant NS (SRNS) upon presentation and after 7 weeks of GC therapy. Plasma endogenous thrombin potential (ETP), antithrombin (AT) activity, and albumin (Alb) were measured using thrombin generation, amidolytic, and colorimetric assays, respectively. ResultsIn a rat model of NS, both High-MP and Pio improved proteinuria and corrected hypoalbuminemia, ETP and AT activity (P<0.05). Proteinuria (P=0.005) and hypoalbuminemia (P<0.001) were correlated with ETP. In childhood NS, while ETP was not different at presentation, GC therapy improved proteinuria, hypoalbuminemia, and ETP in children with SSNS (P<0.001) but not SRNS (P=0.330). ConclusionsBoth Pio and GC diminish proteinuria and significantly alleviate hypercoagulopathy. Both Pio and MP improved hypercoagulopathy in rats, and successful GC therapy (SSNS) also improved hypercoagulopathy in childhood NS. These data suggest that even a partial reduction in proteinuria may reduce NS-associated thrombotic risk. SIGNIFICANCE STATEMENTNephrotic syndrome (NS) is characterized by massive proteinuria and is complicated by a complex, acquired hypercoagulopathy that markedly increases the risk for potentially life-threatening venous thromboembolism (VTE). This study demonstrates a strong correlation between proteinuria reduction and improvement of an established VTE-risk biomarker, in both a well-established animal model and in childhood NS before and after steroid treatment. We show that nuclear receptor agonists with known disparate mechanisms of action successfully reduce proteinuria and simultaneously improve NS-associated hypercoagulopathy. These data suggest that complete or partial proteinuria reduction by any therapeutic modality may concurrently reduce NS-associated thrombotic risk.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Waller, A. P., Agrawal, S., Wolfgang, K. J., Kino, J., Chanley, M. A., Smoyer, W. E., Kerlin, B. A., Pediatric Nephrology Research Consortium (PNRC),. 2020-01-07. Nephrotic Syndrome-Associated Hypercoagulopathy is Alleviated by Nuclear Receptor Agonist Therapy with both Pioglitazone and Glucocorticoids. https://doi.org/10.1101/2020.01.07.897751

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

NAE1-Dependent Protein Neddylation Preserves Endothelial Identity and Vascular Integrity

Background: Endothelial dysfunction is a central driver of cardiovascular and inflammatory diseases, yet the post-translational mechanisms that preserve endothelial homeostasis remain incompletely understood. Protein neddylation, the covalent conjugation of a ubiquitin-like modifier, regulates diverse cellular processes, yet its physiological role in the vascular endothelium remains unknown. This study investigated whether protein neddylation is required to preserve endothelial identity and vascular homeostasis. Methods: We generated tamoxifen-inducible endothelial-specific Nae1 knockout mice to inhibit neddylation and combined bulk RNA sequencing, single-cell and single-nucleus transcriptomics, quantitative proteomics, biochemical analyses, and gain- and loss-of-function approaches to define the role of endothelial neddylation in vascular homeostasis and inflammatory injury. Results: Endothelial-specific Nae1 deletion caused rapid mortality associated with vascular leakage, platelet accumulation, inflammation, and multi-organ injury. Multi-omics analyses demonstrated profound loss of endothelial identity, characterized by suppression of core endothelial programs and activation of inflammatory, procoagulant, and pyroptotic pathways. Single-cell analyses revealed progressive endothelial dysfunction culminating in depletion of the endothelial population and remodeling of the vascular niche. Mechanistically, endothelial neddylation deficiency activated gasdermin D (GSDMD)- and gasdermin E (GSDME)-dependent pyroptosis, whereas dual inhibition of GSDMD and GSDME markedly attenuated inflammatory transcriptomic remodeling, vascular injury, hepatocyte death, immune cell infiltration, and platelet accumulation. Translational analyses demonstrated reduced endothelial neddylation in experimental endotoxemia and decreased expression of neddylation pathway components in human atherosclerosis and COVID-19 datasets. Conversely, restoration of endothelial neddylation partially reversed inflammatory endothelial transcriptomic reprogramming in vivo. Conclusions: NAE1-dependent protein neddylation is an essential regulator of endothelial identity and vascular integrity. Loss of endothelial neddylation promotes gasdermin-dependent pyroptosis and thrombo-inflammatory vascular injury, whereas restoration of the neddylation pathway mitigates inflammatory endothelial dysfunction. These findings identify endothelial neddylation as a fundamental mechanism maintaining vascular homeostasis and a potential therapeutic target for cardiovascular and inflammatory diseases.

pathology

The NAD Metabolome is Functionally Depressed in Patients Undergoing Liver Transplantation for Alcohol-related Liver Disease

Nicotinamide adenine dinucleotide (NAD+) and related coenzymes play critical roles in liver function. Though hepatic alcohol metabolism depresses NAD+, current understanding of the NAD+ metabolome in alcohol-related liver disease (ArLD) is based on animal models. We used human liver samples to quantify the NAD+ metabolome in ArLD with samples obtained at the time of liver transplantation or resection at University Hospitals Birmingham NHS Foundation Trust (UHB). The severity of steatohepatitis in liver from patients with ArLD was assessed with standard liver function tests (LFT) and histology. NAD-targeted quantitative metabolomic analysis of liver tissue was performed by liquid chromatography-tandem mass spectrometry (LC-MS). Seventy-two human liver specimens were analyzed including 43 with ArLD. The NAD+ metabolome differed significantly between different types of liver disease (two-way ANOVA p = 0.001). ArLD liver tissue showed markedly depressed concentrations of NAD+ (432 M vs. 616 M in NL) and precursor molecules nicotinic acid and nicotinamide riboside. There was a significant overall difference in the NAD+ metabolome between ArLD samples with and without steatohepatitis (two-way ANOVA p = 0.018). After correcting for multiple comparisons, a significant difference for individual components of the metabolome was observed for the concentration of NAD+ (mean 451 M vs. 381 M, p = 0.045). NAD+ concentration was inversely related to serum bilirubin concentration (r2 -0.127, p = 0.04) and positively correlated with myeloperoxidase activity (r2 0.31, p = 0.003). The concentration of NAD+ and its precursor molecules are significantly reduced in ArLD and are associated with disease activity. Conclusion: Liver samples from people with ArLD show depressed NAD+ and precursor levels as well as depressed myeloperoxidase activity.

pathology

Deficient ER acetyl-CoA import in acinar cells leads to chronic pancreatitis

Maintaining endoplasmic reticulum (ER) proteostasis is essential for pancreatic acinar cell function. Under conditions of severe ER stress, activation of pathogenic unfolded protein response pathways play a central role in the development and progression of pancreatitis. A key event in this pathogenic response is a loss of the transcription factor spliced XBP1 (XBP1s) and activation of the PERK pathway. Less is known of the consequence of perturbing ER-associated post-translational protein modification during pancreatitis. Here we show that expression of the ER acetyl-CoA transporter AT-1, necessary for ER protein acetylation, lies downstream of XBP1s and is significantly downregulated during the onset of pancreatitis. Genetic deletion of AT-1 in acinar cells of adult pancreas induces chronic ER stress marked by activation of both the XBP1s and PERK pathways, leading to mild/moderate chronic pancreatitis evidenced by accumulation of intracellular trypsin, immune cell infiltration, and fibrosis, but little pancreatic degeneration. Two-day induction of acute on chronic pancreatitis in AT-1 acinar specific knockout mice results in a severe CP phenotype with pronounced pancreatic atrophy. These findings uncover a new layer of complexity of the pathological ER stress response and its impact on pancreatic disease.

pathology