Allograft Fibrosis Research Articles

Oxymatrine attenuates chronic allograft rejection by modulating immune responses and inhibiting fibrosis

BackgroundChronic rejection (CR) is a significant obstacle to long-term allograft survival. Oxymatrine (OMT) is a prominent bioactive compound widely utilized in traditional Chinese medicine for the management of inflammatory disorders and it has considerable potential as a therapeutic candidate for the treatment of CR. MethodsWell-established major histocompatibility complex (MHC) class II mismatched B6 mice. C-H-2bm12-to-C57BL/6 mouse transplantation was used as a CR model. Hematoxylin and eosin (H&E) staining, immunohistochemistry, and Masson's trichrome staining were used to assess pathological changes in the grafts, and the percentages of immune cells were determined by flow cytometry. The effects of OMT on the regulation of CD4+ T cell differentiation and cytokine secretion were verified in vitro. ResultsOMT effectively alleviated pathological graft damage, characterized by chronic changes in intimal lesions, vasculopathy, and fibrosis and significantly prolonged cardiac allograft survival. OMT exerted its immunomodulatory effects by inhibiting T helper 1 (Th1) and T helper 17 (Th17) cell differentiation while promoting Treg differentiation both in vivo and in vitro. Further studies revealed that OMT inhibited the phosphorylation of mammalian target of rapamycin (mTOR), which is a potential mechanism underlying its immunosuppressive effects. OMT also inhibited the activation of B cells and the production of donor-specific antibody (DSA). In addition, OMT effectively alleviated chronic changes in fibrosis in cardiac allografts, and these changes may be related to the inhibition of the transforming growth factor-β (TGF-β)-Smad 2/3 pathway. ConclusionsOMT attenuated CR by modulating the immune response and inhibiting graft fibrosis. Further in-depth investigations of OMT may provide valuable insights into the development of novel therapeutic strategies for CR inhibition.

A blood-based PT-LIFE (Pediatric Liver Transplantation-LIver Fibrosis Evaluation) biomarker panel for noninvasive evaluation of pediatric liver fibrosis after liver transplantation: A prospective derivation and validation study

Allograft fibrosis is increasingly detected in graft biopsies as the postoperative period extends, potentially emerging as a pivotal determinant of long-term graft function and graft survival among pediatric recipients. Currently, there is a paucity of noninvasive diagnostic tools capable of identifying allograft fibrosis in pediatric recipients of liver transplants. This study involved 507 pediatric liver transplant patients and developed a novel blood-based diagnostic assay, Pediatric Liver Transplantation-Liver Fibrosis Evaluation (PT-LIFE), to noninvasively distinguish allograft fibrosis using blood samples, clinical data, and biopsy outcomes. The PT-LIFE assay was derived from a matrix of 23 variables and validated in 2 independent cohorts. It integrates 3 biomarkers (LECT2, YKL-40, FBLN3) with an area under the receiver operating characteristic curve of 0.91. In the pooled analysis, a PT-LIFE score lower than 0.12 identified liver allograft fibrosis semiquantitative scores 0 to 2 with a sensitivity of 91.9%, whereas scores above 0.29 indicated liver allograft fibrosis semiquantitative scores 3 to 6, with a specificity of 88.4%. The PT-LIFE assay presents as a promising noninvasive diagnostic tool for the detection of allograft fibrosis in pediatric liver transplant recipients.

Transient Elastography for Noninvasive Evaluation of Posttransplant Liver Graft Fibrosis in Turkish Children, Ege University Children Hospital Experience.

The influence of advancing fibrosis on graft survival in the context of pediatric liver transplantation accentuates the critical role of protocol-driven liver biopsies, a practice adopted by numerous medical centers. Consequently, the exigency for noninvasive methodologies to assess graft fibrosis assumes heightened importance when conventional clinical and laboratory parameters fail to reveal signs of liver damage. This study aimed to assess the reliability of transient elastography (TE) in pediatric liver transplant recipients to detect graft fibrosis and compare the results of TE in patients who underwent biopsy. This prospective cohort study included liver transplanted children who underwent biopsy at Ege University Children's Hospital between October 1, 2021, and October 31, 2022, and a healthy control group. According to TE, fibrosis was detected in 40 patients, and no fibrosis was detected in 50. The median time to develop fibrosis was 100 months (95% CI [83.1-116.8]). A statistically significant positive correlation existed between LSM and METAVIR fibrosis score (r = 0.562, p = 0.001). There was a statistically significant difference in LSM between patients with F2 fibrosis (7.8-8.8kPa ± 3.2) compared to patients with F0 fibrosis (5.2kPa ± 0.7) (p = 0.005) and F1 fibrosis (6.1kPa ± 1.5) (p = 0.041), on ANOVA. Liver allograft fibrosis is common in long-term follow-up in children who have undergone liver transplantation. Abnormal TE may guide physicians to consider liver biopsy to detect late allograft fibrosis in these children.

Association between Kidney Allograft Fibrosis and Magnetic Resonance Elastography-Derived Stiffness in Kidney Transplant Recipients

Association between Kidney Allograft Fibrosis and Magnetic Resonance Elastography-Derived Stiffness in Kidney Transplant Recipients

Multicenter, prospective, observational study for urinary exosomal biomarkers of kidney allograft fibrosis

Severity of deceased donor kidney fibrosis impacts graft survival in deceased-donor kidney transplantation. Our aim was to identify potential miRNA biomarkers in urinary exosomes that mirror interstitial fibrosis and tubular atrophy (IFTA) severity. Among 109 urine samples from deceased donors, 34 displayed no IFTA in the zero-day biopsy (No IFTA group), while the remaining 75 deceased donor kidneys exhibited an IFTA score ≥ 1 (IFTA group). After analyzing previous reports and electronic databases, six miRNAs (miR-19, miR-21, miR-29c, miR-150, miR-200b, and miR-205) were selected as potential IFTA biomarker candidates. MiR-21, miR-29c, miR-150, and miR-205 levels were significantly higher, while miR-19 expression was significantly lower in the IFTA group. MiR-21 (AUC = 0.762; P < 0.001) and miR-29c (AUC = 0.795; P < 0.001) showed good predictive accuracy for IFTA. In the No IFTA group, the eGFR level at 1 week after transplantation was significantly higher compared to the IFTA group (41.34 mL/min/1.73m2 vs. 28.65 mL/min/1.73m2, P = 0.012). These findings signify the potential of urinary exosomal miRNAs as valuable biomarker candidates for evaluating the severity of IFTA in deceased donor kidneys before they undergo recovery.

MNK-driven eIF4E phosphorylation regulates the fibrogenic transformation of mesenchymal cells and chronic lung allograft dysfunction.

Tissue fibrosis remains unamenable to meaningful therapeutic interventions and is the primary cause of chronic graft failure after organ transplantation. Eukaryotic translation initiation factor (eIF4E), a key translational regulator, serves as convergent target of multiple upstream profibrotic signaling pathways that contribute to mesenchymal cell (MC) activation. Here, we investigate the role of MAP kinase-interacting serine/threonine kinase-induced (MNK-induced) direct phosphorylation of eIF4E at serine 209 (Ser209) in maintaining fibrotic transformation of MCs and determine the contribution of the MNK/eIF4E pathway to the pathogenesis of chronic lung allograft dysfunction (CLAD). MCs from patients with CLAD demonstrated constitutively higher eIF4E phosphorylation at Ser209, and eIF4E phospho-Ser209 was found to be critical in regulating key fibrogenic protein autotaxin, leading to sustained β-catenin activation and profibrotic functions of CLAD MCs. MNK1 signaling was upregulated in CLAD MCs, and genetic or pharmacologic targeting of MNK1 activity inhibited eIF4E phospho-Ser209 and profibrotic functions of CLAD MCs in vitro. Treatment with an MNK1/2 inhibitor (eFT-508) abrogated allograft fibrosis in an orthotopic murine lung-transplant model. Together these studies identify what we believe is a previously unrecognized MNK/eIF4E/ATX/β-catenin signaling pathway of fibrotic transformation of MCs and present the first evidence, to our knowledge, for the utility of MNK inhibitors in fibrosis.

#2566 Clinicopathological and molecular characteristics of plasma cell rich rejection in renal transplant biopsies

Abstract Background and Aims Plasma cell rich rejection (PCRR) is an uncommon, ill-defined type of renal allograft rejection in the literature considered as a subtype of T cell-mediated rejection (TCMR). PCRR has poorer clinical outcome and is often refractory to classic immunosuppressive therapy. Our study analyzed In this study, we analyzed PCRR in a large cohort of patients who underwent renal transplantation at the Amsterdam UMC. Our objective was to study clinical, histological and molecular signatures of PCRR in comparison to other types of rejection, especially late presentations of TCMR and ABMR. We hypothesized PCRR could be a specific subtype of allograft rejection with different molecular and cellular characteristics compared to (late) TCMR and ABMR with differences in clinical outcome. Method We retrospectively scored and reclassified the last known biopsy of 263 renal transplant recipients, morphologically classified as rejection according to the 2019 Banff classification. mRNA expression analysis was performed using the Nanostring B-HOT panel on a subset of cases. PCRR was compared to (late) TCMR, ABMR and mixed rejection for renal function follow-up and graft survival. Results mRNA analysis revealed uniquely expressed genes in PCRR including LOX, CPA3, IL4, IL17F, and MMP12. PCRR is enriched for genes related to mast cells, memory B- and T-cells and transcripts involved in NK cells and allograft fibrosis with heterogeneity in gene expression in biopsies with PCRR. PCRR might be a late event compared to late TCMR and ABMR, with a higher degree of total inflammation and fibrosis. Graft survival and kidney function was similar to late TCMR and ABMR during a 5-year follow-up period after renal biopsy Conclusion PCRR represents a distinct late-onset stage of inflammation displaying diverse gene expression patterns, with presence of mainly mast cells, NK cells and transcripts involved in renal allograft fibrosis. Such insights could enable a better and more tailored treatment for these patients and ultimately enhance long-term graft survival for patients affected by PCRR. Clinical outcomes in patients with PCRR appeared similar to late TCMR and ABMR.

Maintaining the optimum level of immunosuppressive agents minimizes risk of liver allograft fibrosis during Pediatric liver transplantation.

Maintaining the optimum level of immunosuppressive agents minimizes risk of liver allograft fibrosis during Pediatric liver transplantation.

Rictor/mTORC2 signalling contributes to renal vascular endothelial-to-mesenchymal transition and renal allograft interstitial fibrosis by regulating BNIP3-mediated mitophagy.

Renal allograft interstitial fibrosis/tubular atrophy (IF/TA) constitutes the principal histopathological characteristic of chronic allograft dysfunction (CAD) in kidney-transplanted patients. While renal vascular endothelial-mesenchymal transition (EndMT) has been verified as an important contributing factor to IF/TA in CAD patients, its underlying mechanisms remain obscure. Through single-cell transcriptomic analysis, we identified Rictor as a potential pivotal mediator for EndMT. This investigation sought to elucidate the role of Rictor/mTORC2 signalling in the pathogenesis of renal allograft interstitial fibrosis and the associated mechanisms. The influence of the Rictor/mTOR2 pathway on renal vascular EndMT and renal allograft fibrosis was investigated by cell experiments and Rictor depletion in renal allogeneic transplantation mice models. Subsequently, a series of assays were conducted to explore the underlying mechanisms of the enhanced mitophagy and the ameliorated EndMT resulting from Rictor knockout. Our findings revealed a significant activation of the Rictor/mTORC2 signalling in CAD patients and allogeneic kidney transplanted mice. The suppression of Rictor/mTORC2 signalling alleviated TNFα-induced EndMT in HUVECs. Moreover, Rictor knockout in endothelial cells remarkably ameliorated renal vascular EndMT and allograft interstitial fibrosis in allogeneic kidney transplanted mice. Mechanistically, Rictor knockout resulted in an augmented BNIP3-mediated mitophagy in endothelial cells. Furthermore, Rictor/mTORC2 facilitated the MARCH5-mediated degradation of BNIP3 at the K130 site through K48-linked ubiquitination, thereby regulating mitophagy activity. Subsequent experiments also demonstrated that BNIP3 knockdown nearly reversed the enhanced mitophagy and mitigated EndMT and allograft interstitial fibrosis induced by Rictor knockout. Consequently, our study underscores Rictor/mTORC2 signalling as a critical mediator of renal vascular EndMT and allograft interstitial fibrosis progression, exerting its impact through regulating BNIP3-mediated mitophagy. This insight unveils a potential therapeutic target for mitigating renal allograft interstitial fibrosis.

Outcomes of Bladder Washout for the Treatment of Recurrent Urinary Tract Infections After Renal Transplantation.

Background Current literature suggests that anywhere from 2.9-27% of renal transplant recipients (RTR) will develop recurrent urinary tract infections (UTIs) (≥2 UTIs over six months or ≥3 UTIs over 12 months). Recurrent UTIs are of particular importance to RTR given its increased risk for allograft fibrosis and overall patient survival. Alternative solutions are needed for the management of recurrent UTIs, especially given the vulnerability of RTR to UTIs. We hypothesize that bladder washout (BW) reduces the incidence and recurrence of UTIs in RTR. Methods This is a retrospective study evaluating the utility of BW procedures on RTR diagnosed with recurrent UTIs between December 2013 and July 2021 at a single center. Results A total of 106 patients were included in the study with a total of 118 BW performed. 69% of patients were successfully treated with BW, meaning they no longer met the criteria for recurrent UTIs (<1 UTI) in the six-month post-BW period. The mean number of UTIs was 2.76 (range 2-7) before the BW and 1.16 (range 0-5) after the BW. On average, there were 1.60 fewer UTIs in the post-BW period compared to the pre-BW period (p<0.0001). There is no statistically significant difference in success rates stratified by bacterial class (p=1) or antimicrobial resistance class (p=0.6937). Conclusion BWdecreased the incidence of UTIs in the six-month post-operative period as nearly 70% of patients did not have UTI recurrence. This data provides evidence that BW may have utility in transplant recipients with recurrent UTIs. We hope this will stimulate further prospective randomized studies in this area.

Progress in the diagnosis and treatment of graft fibrosis after liver transplantation

AbstractLiver transplantation (LT) is considered one of the best treatments for patients with end‐stage liver diseases. However, some patients with no significant clinical manifestations or abnormal laboratory tests still experience graft fibrosis during postoperative follow‐up, which is often recognized by graft histopathology. Graft fibrosis can lead to graft dysfunction, thereby reducing the survival time of the recipient and even requiring re‐transplantation. Currently, noninvasive methods are widely applied in the assessment of hepatic and allograft fibrosis. Although both noninvasive diagnostic models based on laboratory examination indicators and elastography technology that can quantify liver stiffness have some value in the evaluation of fibrosis, the diagnostic accuracy and characteristics of these various methods vary and cannot replace liver biopsy completely. In recent years, some liver‐protective drugs and proprietary Chinese traditional medicines have been proven to delay or reverse chronic liver fibrosis. Nevertheless, their efficacy and safety for LT recipients need to be further verified. This article reviews the diagnosis and treatment of graft fibrosis after LT to provide a reference for improving the overall survival rate of LT recipients.

Effect of Spironolactone on Kidney Function in Kidney Transplant Recipients (the SPIREN trial): A Randomized Placebo-Controlled Clinical Trial.

Long-term kidney allograft survival is hampered by progressive interstitial fibrosis and tubular atrophy. The SPIREN trial tested the hypothesis that the mineralocorticoid receptor antagonist spironolactone stabilizes kidney function and attenuates glomerular barrier injury in kidney transplant patients treated with calcineurin inhibitors. Randomized, placebo-controlled, double blind clinical trial including 188 prevalent kidney transplant patients. Patients were randomized to spironolactone or placebo for three years. Glomerular filtration rate was measured along with proteinuria and kidney fibrosis. The primary endpoint was change in measured glomerular filtration rate. Secondary outcomes were 24h proteinuria, kidney allograft fibrosis and cardiovascular events. Measured glomerular filtration rates, 24h proteinuria and blood pressure were determined yearly. Kidney biopsies were collected at baseline and after two years (n=48). Fibrosis was evaluated by quantitative stereology and classified according to Banff. The groups were comparable at baseline except for slightly older allografts in the spironolactone group. Spironolactone reduced measured glomerular filtration rates (up to -7.6 (95% CI -10.9;-4.3) ml/min compared to placebo) independently of time since transplantation and blood pressure with no impact on the kidney function curve over time and reduced 24h proteinuria after one year. There was no significant effect of spironolactone on the development of interstitial fibrosis. Spironolactone added to standard therapy for three years in kidney transplant patients did not improve kidney function, long-term proteinuria or interstitial fibrosis.

Fibrotic progression from acute cellular rejection is dependent on secondary lymphoid organs in a mouse model of chronic lung allograft dysfunction

Chronic lung allograft dysfunction (CLAD) remains one of the major limitations to long-term survival after lung transplantation. We modified a murine model of CLAD and transplanted left lungs from BALB/c donors into B6 recipients that were treated with intermittent cyclosporine and methylprednisolone postoperatively. In this model, the lung allograft developed acute cellular rejection on day 15 which, by day 30 after transplantation, progressed to severe pleural and peribronchovascular fibrosis, reminiscent of changes observed in restrictive allograft syndrome. Lung transplantation into splenectomized B6 alymphoplastic (aly/aly) or splenectomized B6 lymphotoxin-β receptor–deficient mice demonstrated that recipient secondary lymphoid organs, such as spleen and lymph nodes, are necessary for progression from acute cellular rejection to allograft fibrosis in this model. Our work uncovered a critical role for recipient secondary lymphoid organs in the development of CLAD after pulmonary transplantation and may provide mechanistic insights into the pathogenesis of this complication.

ACOX1 deficiency-induced lipid metabolic disorder facilitates chronic interstitial fibrosis development in renal allografts

Chronic interstitial fibrosis presents a significant challenge to the long-term survival of transplanted kidneys. Our research has shown that reduced expression of acyl-coenzyme A oxidase 1 (ACOX1), which is the rate-limiting enzyme in the peroxisomal fatty acid β-oxidation pathway, contributes to the development of fibrosis in renal allografts. ACOX1 deficiency leads to lipid accumulation and excessive oxidation of polyunsaturated fatty acids (PUFAs), which mediate epithelial–mesenchymal transition (EMT) and extracellular matrix (ECM) reorganization respectively, thus causing fibrosis in renal allografts. Furthermore, activation of Toll-like receptor 4 (TLR4)-nuclear factor kappa-B (NF-κB) signaling induced ACOX1 downregulation in a DNA methyltransferase 1 (DNMT1)-dependent manner. Overconsumption of PUFA resulted in endoplasmic reticulum (ER) stress, which played a vital role in facilitating ECM reorganization. Supplementation with PUFAs contributed to delayed fibrosis in a rat model of renal transplantation. The study provides a novel therapeutic approach that can delay chronic interstitial fibrosis in renal allografts by targeting the disorder of lipid metabolism.

Dysregulated lipid metabolism is associated with kidney allograft fibrosis

BackgroundInterstitial fibrosis and tubular atrophy (IF/TA), a histologic feature of kidney allograft destruction, is linked to decreased allograft survival. The role of lipid metabolism is well-acknowledged in the area of chronic kidney diseases; however, its role in kidney allograft fibrosis is still unclarified. In this study, how lipid metabolism contributes to kidney allografts fibrosis was examined.MethodsA comprehensive bioinformatic comparison between IF/TA and normal kidney allograft in the Gene Expression Omnibus (GEO) database was conducted. Further validations through transcriptome profiling or pathological staining of human recipient biopsy samples and in rat models of kidney transplantation were performed. Additionally, the effects of enhanced lipid metabolism on changes in the fibrotic phenotype induced by TGF-β1 were examined in HK-2 cell.ResultsIn-depth analysis of the GEO dataset revealed a notable downregulation of lipid metabolism pathways in human kidney allografts with IF/TA. This decrease was associated with increased level of allograft rejection, inflammatory responses, and epithelial mesenchymal transition (EMT). Pathway enrichment analysis showed the downregulation in mitochondrial LC-fatty acid beta-oxidation, fatty acid beta-oxidation (FAO), and fatty acid biosynthesis. Dysregulated fatty acid metabolism was also observed in biopsy samples from human kidney transplants and in fibrotic rat kidney allografts. Notably, the areas affected by IF/TA had increased immune cell infiltration, during which increased EMT biomarkers and reduced CPT1A expression, a key FAO enzyme, were shown by immunohistochemistry. Moreover, under TGF-β1 induction, activating CPT1A with the compound C75 effectively inhibited migration and EMT process in HK-2 cells.ConclusionsThis study reveal a critical correlation between dysregulated lipid metabolism and kidney allograft fibrosis. Enhancing lipid metabolism with CPT1A agonists could be a therapeutic approach to mitigate kidney allografts fibrosis.

Arterial spin labeling in assessment of interstitial fibrosis in renal allografts

Objective: To explore the feasibility and application value of arterial spin labeling (ASL) in evaluating the degree of renal fibrosis after kidney transplantation. Methods: This is a cross-sectional study. Renal transplant recipients who received treatment at the First Affiliated Hospital of Soochow University from December 2021 to December 2022 were enrolled. All participants underwent ASL scan, and the values of renal cortical renal blood flow (RBF) were measured through post-processing software. The participants were divided into different groups according to the Banff interstitial fibrosis score (ci score) of the transplanted kidneys, and then relevant indicators were compared. One-way analysis of variance was conducted to compare the differences in renal cortical RBF among the groups. Spearman correlation analysis was employed to investigate the association between renal cortical RBF and ci score of the transplanted kidney. Receiver operating characteristic curve was used to analyze the diagnostic effectiveness of renal cortical RBF and laboratory indicators for distinguishing varying degrees of fibrosis in transplanted kidneys. The Delong test was utilized to compare the area under the curve (AUC). Results: A total of 60 patients (42 males and 18 females) were included in the study, with a mean age of (44.6±10.8) years. All patients were divided into 4 groups: ci0 group (ci score=0, 11 cases), ci1 group (ci score=1, 21 cases), ci2 group (ci score=2, 20 cases), and ci3 group (ci score=3, 8 cases). With an increase in the degree of fibrosis in the transplanted kidney, there was a corresponding decrease in the renal cortical RBF value. The differences in renal cortical RBF values among the 4 groups were statistically significant[ci0 group: (214.9±28.5) ml·(100 g)-1·min-1; ci1 group: (181.7±29.3) ml·(100 g)-1·min-1; ci2 group: (158.8±39.2) ml·(100 g)-1·min-1; ci3 group: (123.1±27.2) ml·(100 g)-1·min-1; F=14.02, P<0.001]. The renal cortical RBF was moderately negatively correlated with the ci score (r=-0.644, P<0.001). The AUC for discriminating between ci0 and ci1-3 of renal cortical RBF and 24-hour urine protein was 0.881 (95%CI: 0.772-0.950) and 0.680 (95%CI: 0.547-0.795), respectively. The AUC for renal cortical RBF was significantly higher than that for 24-hour urine protein (P=0.047). The renal cortical RBF can distinguish between ci0-1 and ci2-3, as well as ci0-2 and ci3, with the corresponding AUC value of 0.796 (95%CI: 0.673-0.889) and 0.900 (95%CI: 0.795-0.963), respectively. Conclusion: ASL can quantitatively assess renal blood perfusion in transplanted kidneys and demonstrates high operational efficacy in distinguishing varying degrees of fibrosis in the transplanted kidneys.

NSD2 modulates Drp1-mediated mitochondrial fission in chronic renal allograft interstitial fibrosis by methylating STAT1

Renal interstitial fibrosis/tubular atrophy (IF/TA) is a prominent pathological feature of chronic allograft dysfunction (CAD). Our previous study has demonstrated that epithelial-mesenchymal transition (EMT) plays a significant role in shaping the development of IF/TA. Nuclear SET domain (NSD2), a histone methyltransferase catalyzing methylation at lysine 36 of histone 3, is crucially involved in the development and progression of solid tumors. But its role in the development of renal allograft interstitial fibrosis has yet to be elucidated. Here, we characterize NSD2 as a crucial mediator in the mouse renal transplantation model in vivo and a model of tumor necrosis factor-α (TNF-α) stimulated-human renal tubular epithelial cells (HK-2) in vitro. Functionally, NSD2 knockdown inhibits EMT, dynamin-related protein 1 (Drp1)-mediated mitochondrial fission in mice. Conversely, NSD2 overexpression exacerbates fibrosis-associated phenotypes and mitochondrial fission in tubular cells. Mechanistically, tubular NSD2 aggravated the Drp-1 mediated mitochondrial fission via STAT1/ERK/PI3K/Akt signaling pathway in TNF-α-induced epithelial cell models. Momentously, mass spectrometry (MS) Analysis and site-directed mutagenesis assays revealed that NSD2 interacted with and induced Mono-methylation of STAT1 on K173, leading to its phosphorylation, IMB1-dependent nuclear translocation and subsequent influence on TNF-α-induced EMT and mitochondrial fission in NSD2-dependent manner. Collectively, these findings shed light on the mechanisms and suggest that targeting NSD2 could be a promising therapeutic approach to enhance tubular cell survival and alleviate interstitial fibrosis in renal allografts during CAD.

Targeted changes in blood lipids improves fibrosis in renal allografts

BackgroundChronic interstitial fibrosis is the primary barrier against the long-term survival of transplanted kidneys. Extending the lifespan of allografts is vital for ensuring the long-term health of patients undergoing kidney transplants. However, few targets and their clinical applications have been identified. Moreover, whether dyslipidemia facilitates fibrosis in renal allograft remains unclear.MethodsBlood samples were collected from patients who underwent kidney transplantation. Correlation analyses were conducted between the Banff score and body mass index, and serum levels of triacylglycerol, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. A rat model of renal transplantation was treated with the lipid-lowering drug, fenofibrate, and kidney fibrosis levels were determined by histochemical staining. Targeted metabolomic detection was conducted in blood samples from patients who underwent kidney transplantation and were divided into fibrotic and non-fibrotic groups. Rats undergoing renal transplantation were fed either an n-3 or n-6 polyunsaturated fatty acid (PUFA)-enriched diet. Immunohistochemical and Masson’s trichrome staining were used to determine the degree of fibrosis.ResultsHyperlipidemia was associated with fibrosis development. Treatment with fenofibrate contributed to improve fibrosis in a rat model of renal transplantation. Moreover, n-3 PUFAs from fibrotic group showed significant downregulation compared to patients without fibrotic renal allografts, and n-3 PUFAs-enriched diet contributed to delayed fibrosis in a rat model of renal transplantation.ConclusionsThis study suggests that hyperlipidemia facilitates fibrosis of renal allografts. Importantly, a new therapeutic approach was provided that may delay chronic interstitial fibrosis in transplanted kidneys by augmenting the n-3 PUFA content in the diet.

Association between fibrosis-related gene polymorphism and long-term allograft outcome in renal transplant recipients

BackgroundRenal allograft fibrosis is one of characteristic causes of long-term renal function loss. The purpose of our study is to investigate the association between fibrosis-related genes single nucleotide polymorphism (SNPs) and kidney function in 5 years after kidney transplantation.MethodsA total of 143 recipients were eligible for screening with 5-year follow-up information and SNP sequencing information from blood samples were included in this study. Minor Allele Frequency (MAF) and Hardy–Weinberg Equilibrium (HWE) analysis was conducted to identify tagger single-nucleotide polymorphisms (SNPs) and haplotypes. SNPs associated with the fifth year chronic kidney disease (CKD) staging were screened by SPSS and the “SNPassoc” package in RStudio and used for subsequent prediction model construction.ResultsA total of 275 renal transplant-related SNPs identified after target sequencing analysis. 64 Tagger SNPs were selected, and two SNPs (rs13969 and rs243849) were statistically significant for stage of CKD in 5 years. Finally, a model based on Gender, Age, rs1396, and rs243849 was constructed by multivariate linear regression analysis. Additionally, this model has a good performance in predicting uremia five years after kidney transplantation.ConclusionTwo SNPs (rs13969 and rs243849) were identified to be significantly associated with long-term renal allograft function. Based on this, a prediction model for long-term allograft function was established containing Gender, Age, rs1396, and rs243849. However, an independent cohort should be enrolled to validate the predicting performance.

Long-term Outcome of Asymptomatic Patients With Graft Fibrosis in Protocol Biopsies After Pediatric Liver Transplantation.

The histological prevalence of allograft fibrosis in asymptomatic children after liver transplantation (LT) is well documented. However, long-term graft and patient survival remain unclear. This retrospective multicenter study aims to determine the prevalence of allograft fibrosis and analyze the long-term outcome for patients transplanted in childhood. We reviewed clinical data of children who had undergone 10-y protocol liver biopsies. We excluded patients with autoimmune hepatitis, primary sclerosing cholangitis, hepatitis B or C, and retransplantation. In total, 494 patients transplanted in childhood across 12 international transplant centers were included. We evaluated the development of fibrosis by comparing the results with biopsies obtained 5 and 15 y post-LT. Histological findings were correlated with graft and patient survival up to 20 y post-LT. In the 10-y biopsies, periportal or pericentral fibrosis was observed in 253 patients (51%), 87 (18%) had bridging fibrosis, 30 (6%) had cirrhosis, and 124 (25%) had no fibrosis. The prevalence and stage of graft fibrosis significantly progressed from 5 to 10 y. At 10 y, the severity of fibrosis correlated significantly with inflammation. Patients with graft cirrhosis in the 10-y biopsy were more likely to die or require retransplantation subsequently ( P = 0.027). At 10 y post-LT, most patients transplanted in childhood developed fibrosis, based on the protocol liver biopsies. Although mild-to-moderate graft fibrosis did not largely affect patient or graft survival up to 20 y post-LT, this progressive fibrosis finding has substantial implications for developing cirrhosis and portal hypertension in adult care.