Biology subjects

Legouis, D.

Publications and source records attributed to Legouis, D..

4 recordsLinked to original sources

bioRxiv2025

Tissular glucocorticoid reactivating enzyme 11beta-HSD1 drives pathogenic myofibroblast differentiation in chronic kidney disease

Chronic kidney disease (CKD) is a growing public health crisis, affecting over 10% of the global population and significantly increasing mortality and morbidity. Irrespective of its underlying cause, tubulointerstitial fibrosis (TIF) is a hallmark of CKD progression, with myofibroblasts being the primary effectors of renal fibrosis. Here, we show that 11beta-hydroxysteroid dehydrogenase type 1 (11{beta}-HSD1) is a critical driver of pathogenic myofibroblast differentiation and fibrosis in CKD. Using genetic deletion and pharmacological inhibition of 11{beta}-HSD1 in mouse models, we demonstrate a marked reduction in TIF severity and improved renal function, linked to the suppression of a regulatory myofibroblast (Reg-MF) subpopulation. Single-cell and spatial transcriptomics data reveal that 11{beta}-HSD1 is essential for the activation and expansion of Reg-MFs, which is conserved across species and predicts worse outcomes in CKD patients and kidney allograft recipients. These findings establish a direct link between 11{beta}-HSD1 activity and renal fibrogenesis, highlighting its role during the transition from pericytes to pathogenic Reg-MFs. Our results support 11{beta}-HSD1 inhibition as a promising therapeutic strategy to mitigate CKD progression, offering both mechanistic insights and translational potential for improving patient outcomes.

physiology↗

bioRxiv2024

The preferential injury of outer renal medulla after ischemia-reperfusion relies on high oxidative metabolism

Acute kidney injury (AKI) is a prevalent and significant complication in critically ill patients, and its management remains a considerable challenge. The kidney is a highly metabolic organ, consuming and producing substantial amounts of ATP, mainly through mitochondrial oxidative phosphorylation. Recently, mitochondrial dysfunction has been identified as a key factor in the pathophysiology of AKI and the progression to chronic kidney disease. The kidney is a complex organ, comprising millions of structural and functional units. These nephrons are composed of different cell types dwelling within specific metabolic microenvironment. Whether the metabolic spatialization in the kidney has consequences on tubular injury distribution and severity remains unclear. In this study, we identified the high metabolic rate of the outer stripe of the outer medulla (OSOM) and its substrate preference flexibility, relying on both glycolysis and fatty acid oxidation (FAO) to fulfill its ATP demands. We demonstrated that the OSOM is susceptible to mitochondrial and FAO impairment induced by propofol, the most used sedative in intensive care settings, which exacerbates tubular injury during AKI. In the clinical setting, the cumulative dose of propofol is positively correlated with oxidative metabolism disruption and histological and function outcomes in renal allograft recipients. Finally, we found that the loop of Henle, the OSOM major constituent, was the most injured segment during AKI in patients. This study shows how renal metabolic spatialization impacts tubular injury severity. We identified the OSOM as the most metabolically active and the most injured region of the kidney both in humans and mice. We demonstrated that propofol is a potent inhibitor of renal mitochondrial function and FAO exacerbating tubular injury in the OSOM upon IRI. Translational StatementO_LIAerobic metabolism is basally enhanced in the renal OSOM, including the S3 proximal tubule, the thick ascending limb of the loop of Henle and Distal Convoluted Tubule C_LIO_LIPT cells as well as TAL cells are significantly targeted by injury in human AKI. C_LIO_LIPropofol impairs renal mitochondrial function worsening tubular injury during ischemia reperfusion. C_LI

physiology↗

bioRxiv2021

Single-cell profiling in COVID-19 associated acute kidney injury reveals patterns of tubule injury and repair in human

The cellular mechanisms of kidney tubule repair are poorly characterized in human. Here, we applied single-nucleus RNA sequencing to analyze the kidney in the first days after acute injury in 5 critically ill patients with COVID-19. We identified abnormal proximal tubule cell states associated with injury, characterized by altered functional and metabolic profiles and by pro-fibrotic properties. Tubule repair involved the plasticity of mature tubule cells in a process of cell de-differentiation and re-differentiation, which displayed substantial similarities between mouse and man. In addition, in man we identified a peculiar tubule reparative response determining the expansion of progenitor-like cells marked by PROM1 and following a differentiation program characterized by the sequential activation of the WNT, NOTCH and HIPPO signaling pathways. Taken together, our analyses reveal cell state transitions and fundamental cellular hierarchies underlying kidney injury and repair in critically ill patients.

pathology↗

bioRxiv2019

Impaired renal gluconeogenesis is a major determinant of acute kidney injury associated mortality

Nature letterAcute Kidney Injury (AKI) is strongly associated with adverse outcome and mortality independently of the cause of renal damage1-3. The mechanisms determining the deleterious systemic effects of AKI are poorly understood and specific interventions, including optimization of renal replacement therapy, had a marginal effect on AKI-associated mortality in clinical trials4-8. The kidney contributes to up to 40% of systemic glucose production by gluconeogenesis during fasting and stress conditions, mainly synthesized from lactate in the proximal tubule9-12, rendering this organ a major systemic lactate disposal13. Whether kidney gluconeogenesis is impaired during AKI and how this might influence systemic metabolism remains unknown. Here we demonstrate that glucose production and lactate clearance are impaired during human AKI using renal arteriovenous catheterization in patients. Using single cell transcriptomics in mice and RNA sequencing in human biopsies, we show that glycolytic and gluconeogenetic pathways are modified during AKI in the proximal tubule specifically, explaining the metabolic alterations. We further demonstrate that impaired renal gluconeogenesis and lactate clearance during AKI are major determinants of systemic glucose and lactate levels in critically ill patients. Most importantly, altered glucose metabolism in AKI emerged as a major determinant of AKI-associated mortality. Thiamine supplementation restored renal glucose metabolism and substantially reduced AKI-associated mortality in intensive care patients. This study highlights an unappreciated systemic role of renal glucose and lactate metabolism in stress conditions, delineates general mechanisms explaining AKI-associated mortality and introduces a potential therapeutic intervention for a highly prevalent clinical condition with limited therapeutic options.

cell biology↗