Biology subjects

Lotfollahzadeh, S.

Publications and source records attributed to Lotfollahzadeh, S..

2 recordsLinked to original sources

bioRxiv2025

Tryptophan metabolism reprogramming contributes to the prothrombotic milieu in mice and humans infected with SARS-CoV-2

SARS-CoV-2 infection disturbs the coagulation balance in the blood, triggering thrombosis and contributing to organ failure. The role of prothrombotic metabolites in COVID-19-associated coagulopathy remains elusive. Leveraging K18-hACE2 mice infected with SARS-CoV-2, we observed higher levels of the tryptophan metabolite, kynurenine, compared to controls. SARS-CoV-2 infected mice showed a significant upregulation of enzymes controlling Kynurenine biogenesis, such as indoleamine 2,3-dioxygenase (IDO-1) and tryptophan 2,3-dioxygenase levels in kidneys and liver, respectively, as well as changes in the enzymes involved in kynurenine catabolism, including kynurenine monooxygenase and kynurinase. Consistent with the agonistic role of these metabolites in Aryl Hydrocarbon Receptor (AHR) signaling, AHR activation and its downstream mediator, tissue factor (TF), a highly potent procoagulant factor, was observed in endothelial cells (ECs) of lungs and kidneys of infected mice. These findings were validated in humans, where compared to controls, sera of COVID-19 patients showed increased levels of Kynurenine, kynurenic acid, anthranilic acid, and quinolinic acid. Activation of the AHR-TF axis was noted in the kidneys and lungs of COVID-19 patients, and COVID-19 sera showed higher IDO-1 activity than controls. Levels of Kyn in COVID-19 patients correlated strongly with the TF-inducing activity of COVID-19 sera on ECs. A specific IDO-1 inhibitor or AHR inhibitor separately or in combination suppressed COVID-19 sera-induced TF activity in ECs. Together, we identified IDO-1 as upregulated by SARS-CoV-2 infection, resulting in augmented Kyn and its prothrombotic catabolites, thereby suggesting the Kyn-AHR-TF axis as possibly a new diagnostic and/or therapeutic target. Key pointsO_LISARS-CoV-2-infection upregulates kynurenine biogenesis in the liver and diminishes kynurenine catabolism in the lungs and kidneys. C_LIO_LIAn increase in kynurenine stimulates the AHR-TF axis in the microvasculature in COVID-19 patients, which is inhibited by pharmacological manipulation. C_LI

systems biology↗

bioRxiv2024

A murine model of cardiovascular-kidney-metabolic syndrome demonstrates compromised limb function in the ischemic hind limb

AbstractsO_ST_ABSBackgroundC_ST_ABSCardiovascular-Kidney-metabolic (CKM) syndrome is a public health problem involving > 90% of the US and results in premature CVD at a relatively preserved GFR. The molecular mediators of CKM are poorly understood, partly due to the lack of a reliable animal model. We set out to generate an animal model with renal and metabolic dysfunctions, using PAD as a CKM manifestation. MethodsA group of C57BL/6 mice was randomized into four groups-a normal diet (ND), a 0.2% adenine diet (AD, a CKD model), a high-fat diet (HFD, a metabolic model), and a combination of HFD+AD (a potential CKM model). Mice underwent a hind limb ischemia surgery. An array of structural (capillary density, soleus muscle evaluation), and functional assays were performed. ResultsCompared to ND mice, AD mice showed loss of weight (40%) and GFR (90%) (P<0.001). The HFD+AD mice had 23-50% higher weight and GFR than the AD group (P = 0.003). The kidneys of HFD+AD showed tubular atrophy, tubulointerstitial fibrosis, immune infiltration, glomerulomegaly, consistent with glomerular hyperperfusion, hypercholesterolemia, impaired glucose tolerance, and adipophilin in the liver, an early marker of hepatic steatosis, and myocardial fibrosis. Compared to ND mice, the AD and HFD+AD mice showed similar reductions in the hind limb perfusion ratios, microcapillary density, Type II muscle fibers, and increased muscle fibrosis, immune infiltration, and lowest cross-sectional muscle area. Compared to AD, HFD+AD mice showed a lower flux ratio and grip strength, all at a GFR double that of the AD group. ConclusionA combination of HFD+AD in mice displays features of CKD (loss of GFR, renal fibrosis), dysfunctional obesity (dyslipidemia, impaired glucose tolerance, hepatic steatosis and glomerulomegaly), and cardiovascular disease (myocardial fibrosis and PAD) at a higher GFR, consistent with the features of CKM. This model can be explored to probe the mechanisms of CKM syndrome.

pathology↗