Project description:16S rRNA sequencing showed that Akkermansia muciniphila (Akk) decreased during the course of HCC tumor development, and daily administration of Akk not only ameliorated liver steatosis and cholesterol biosynthesis but also effectively attenuated the development of NAFLD-induced HCC.
Project description:Neuropilin-1 (NRP1), a co-receptor for various cytokines, including TGF-β, has been identified as a potential therapeutic target for fibrosis. However, its role and mechanism in renal fibrosis remains elusive. Here, we show that NRP1 is upregulated in distal tubular (DT) cells of patients with transplant renal insufficiency and mice with renal ischemia-reperfusion (I-R) injury. Knockout of Nrp1 reduced multiple endpoints of renal injury and fibrosis. We found that Nrp1 facilitates the binding of TNF-α to its receptor in DT cells after renal injury. This signaling results in a downregulation of lysine crotonylation of the metabolic enzyme Cox4i1, decreased cellular energetics and exacerbation of renal injury. Furthermore, by single-cell RNA-sequencing we found that Nrp1-positive DT cells secrete collagen and communicate with myofibroblasts, exacerbating acute kidney injury (AKI)-induced renal fibrosis by activating Smad3. Dual genetic deletion of Nrp1 and Tgfbr1 in DT cells better improves renal injury and fibrosis than either single knockout. Together, these results reveal that targeting of NRP1 represents a promising strategy for the treatment of AKI and subsequent chronic kidney disease.
Project description:Neuropilin-1 (NRP1), a co-receptor for various cytokines, including TGF-β, has been identified as a potential therapeutic target for fibrosis. However, its role and mechanism in renal fibrosis remains elusive. Here, we show that NRP1 is upregulated in distal tubular (DT) cells of patients with transplant renal insufficiency and mice with renal ischemia-reperfusion (I-R) injury. Knockout of Nrp1 reduced multiple endpoints of renal injury and fibrosis. We found that Nrp1 facilitates the binding of TNF-α to its receptor in DT cells after renal injury. This signaling results in a downregulation of lysine crotonylation of the metabolic enzyme Cox4i1, decreased cellular energetics and exacerbation of renal injury. Furthermore, by single-cell RNA-sequencing we found that Nrp1-positive DT cells secrete collagen and communicate with myofibroblasts, exacerbating acute kidney injury (AKI)-induced renal fibrosis by activating Smad3. Dual genetic deletion of Nrp1 and Tgfbr1 in DT cells better improves renal injury and fibrosis than either single knockout. Together, these results reveal that targeting of NRP1 represents a promising strategy for the treatment of AKI and subsequent chronic kidney disease
Project description:8 week-old male C57BL6J mice were given Gram-negative endotoxin (LPS O111:B4, 10 mg/kg) intraperitoneally at time 0. 18 hrs thereafter, they were administered 10 ml/kg 0.9% saline. Mice were sacrificed at 0, 18, or 42 hrs after LPS challenge. Kidneys were immediately collected into TRIzol for RNA preparation. Renal function was measured on blood collected at the time of tissue harvest At t=0hr, mice had normal baseline renal function. At t=18hr, mice exhibited early renal injury, At t=42hr, mice had either recovered normal renal function or had persistent renal injury. We collected kidneys from 3 mice per time point. For the 42 hr time point, we collected kidneys from 3 mice with recovered renal function and kidneys from 3 mice with persistent renal injury. Mouse kidneys selected at successive stages of renal injury and recovery following systemic LPS challenge and volume resuscitation following LPS challenge.
Project description:Using renal ischemia-reperfusion injury as a model of acute kidney injury, we deteremined temporally-released miRNAs released in urinary exosomes during the injury
Project description:Congenital obstructive nephropathy is a common cause of chronic kidney disease and a leading indication for renal transplant in children. The cellular and molecular responses of the kidney to congenital obstruction are incompletely characterized. In this study, we evaluated global transcription in kidneys with graded hydronephrosis in the megabladder (mgb-/-) mouse to better understand the pathophysiology of congenital obstructive nephropathy. Three primary pathways associated with kidney remodeling/repair were induced in mgb-/- kidneys independent of the degree of hydronephrosis. These pathways included retinoid signaling, steroid hormone metabolism, and renal response to injury. Urothelial proliferation and the expression of genes with roles in the integrity and maintenance of the renal urothelium were selectively increased in mgb-/- kidneys. Ngal/Lcn2, a marker of acute kidney injury, was elevated in 36% of kidneys with higher grades of hydronephrosis. Evaluation of Ngalhigh versus Ngallow kidneys identified the expression of several novel candidate markers of renal injury. This study indicates that the development of progressive hydronephrosis in mgb-/- mice results in renal adaptation that includes significant changes in the morphology and potential functionality of the renal urothelium. These observations will permit the development of novel biomarkers and therapeutic approaches to progressive renal injury in the context of congenital obstruction. Gene expression was measured in control, mild, moderate and severely hydronephrotic megabladder mouse kidneys. A total of 6 control kidneys were compared to 18 mutant kidneys from age-matched male animals.
Project description:Podocytes are essential cells of the renal blood filter. They structurally compose the renal blood filter by interdigitating with neighboring podocytes by the means of a modified adherens junction, the slit membrane. In podocyte injury, loss of podocytes is a common feature. Podocyte loss could be mediated by the cleavage of podocyte cell adhesion molecules through the A Disintegrin and Metalloproteinase 10 (ADAM10). Here we show that ADAM10 is highly abundant at the site of blood filtration, namely at podocyte foot processes. Podocyte-expressed ADAM10 is not required for the development of the renal filter but plays a major role in podocyte injury. Following antibody-mediated injury, ADAM10 is upregulated in humans and mice. ADAM10 activity results in the cleavage of cell-cell adhesion molecules. This cleavage paves the way for an activation of the injury related Wnt/-catenin signaling pathway and for podocyte loss. We therefore conclude that ADAM10-mediated ectodomain shedding of injury-related cadherins drives podocyte injury. As part of this project, we have analyzed the membrane proteome of murin podocytes to evaluate the abundance of membrane bound proteases.
Project description:We created a rat renal congestion model and investigated the effect of renal congestion on hemodynamics and molecular mechanisms. The inferior vena cava (IVC) between the renal veins was ligated by suture in male Sprague-Dawley rats to increase upstream IVC pressure and induce congestion in the left kidney only. Left kidney congestion reduced renal blood flow, glomerular filtration rate, and increased renal interstitial hydrostatic pressure. Tubulointerstitial and glomerular injury and medullary thick ascending limb hypoxia were observed only in the congestive kidneys. Molecules related to extracellular matrix expansion, tubular injury, and focal adhesion were upregulated in microarray analysis. Renal decapsulation ameliorated the tubulointerstitial injury. Electron microscopy captured pericyte detachment in the congestive kidneys. Transgelin and platelet-derived growth factor receptors, as indicators of pericyte-myofibroblast transition, were upregulated in the pericytes and the adjacent interstitium. With the compression of the peritubular capillaries and tubules, hypoxia and physical stress induce pericyte detachment, which could result in extracellular matrix expansion and tubular injury in renal congestion.