bluuebunny/crossref_metadata_2025_split huggingface dataset:
#2440 https://era.m-anage.com/era24/en-GB/Submit/submission/abstracts/197764/guidelines
Authors: Jiang Wei , Tang Tao-Tao , LV Linli , Liu Bicheng 
Published: May 2024

Abstract

Background and Aims
Acute kidney injury (AKI) is a critical condition that is strongly related to elevated risks for the progression of chronic kidney disease (CKD). While tubulointerstitial inflammation (TII) is widely accepted as a significant factor in driving this process, the underlying mechanisms responsible for the development of TII are still largely unknown. T cells are increasingly recognized to be involved in tissue injury and exacerbation of the inflammatory response. However, the dynamic landscape of T cell infiltration and their contribution to the chronic transition of AKI remain largely unclear. In this study, we used single-cell RNA sequencing (scRNA-seq) to obtain a high-resolution profile of T cells in a model of unilateral ischemia-reperfusion injury (uIRI) induced AKI to CKD (AtoC) transition and intended to explain their roles during this progress.

Method
Unilateral ischemia-reperfusion injury (uIRI) at multiple time points was used to simulate the transformation of AtoC. Next, the kidneys were isolated into single-cell suspensions and single-cell RNA sequencing (sRNA-seg) was performed to observe the dynamic evolution of T cells during AtoC transition. Further subpopulations of T cells were analyzed and T cell maps were constructed by UMAP. These subpopulations were defined by characteristic genes and their functions were analyzed. The dynamic changes of T cell subsets during AtoC transformation were observed. RNA velocity and pseudotime analysis were used to observe the evolution of T cell subpopulations. Receptor and ligand interaction analysis of the mechanism by T cell subsets role during AtoC. Finally, the sequencing results were further verified by detailed in vitro and in vivo experiments.

Results
PAS and Masson showed that the model of unilateral ischemia-reperfusion injury (uIRI) induced AKI to CKD transition was successfully established. In the chronic phase after AKI, the aggregation of T cells gradually increased. During the transition from AKI to CKD, T cells can be divided into 9 cell subsets, mainly including CD8, TH1 and Treg cells. The proportion of CD8 subsets increased significantly during this process and may originate from proliferating T cell subtypes that emerged rapidly after AKI. Interestingly, CD8 T cells can specifically induce apoptosis of vascular endothelial cells through Fas ligand (FasI)-Fas signaling, which leads to the thinning of peritubular capillaries (PTCs), ultimately leading to the progression of renal fibrosis.

Conclusion
Our results suggest that CD8 T cells can cause the rarefaction of peritubular capillaries and ultimately lead to renal fibrosis, and targeted clearance of CD8 T cells is expected to become a new therapeutic target in the AtoC process.
#245 Deficiency of GADD45α expression mediated tubulointerstitial injury in diabetic nephropathy
Authors: LI Xue Qi , Zhang Jia Xiu , LI Liang , Wu Qin Yi , MA Kun Ling 
Published: May 2024

Abstract

Background and Aims
The tubulointerstitial injury plays crucial roles in the development of diabetic nephropathy (DN). Recently, some studies have reported that disorder of mitochondrial fatty acid β-oxidation in proximal tubules is involved in tubulointerstitial injury of DN. The growth arrest and DNA damage-inducible gene 45 (GADD45) family proteins, especially, GADD45α, plays a crucial role in various cellular processes, such as mitochondrial biogenesis and lipid metabolism. Recent studies have demonstrated that GADD45α facilitates gene activation by inducing DNA demethylation. Therefore, this study aimed to investigate the role of GADD45α in tubulointerstitial injury of DN and its underlying mechanisms.

Methods
Bioinformatics and machine learning techniques were employed to identify differentially expressed genes between healthy individuals and DN patients. Experiments were conducted by using high glucose-treated HK-2 cells and streptozotocin (STZ)-induced mice. Lentivirus carrying the GADD45α gene was used to induce GADD45α overexpression in HK-2 cells. Adeno-Associated Virus vectors carrying LoxP-flanked GADD45α were intravenously injected into γGT-Cre transgenic mice expressing Cre recombinase in renal proximal tubular cells, specifically leading to GADD45α overexpression in proximal tubules.

Results
Through bioinformatics and machine learning techniques, GADD45α was identified and found to exhibit a strong association with tubulointerstitial injury in DN. Further analysis revealed that the expression of GADD45α was decreased in the kidneys of DN patients, diabetic mice, and high glucose-treated HK-2 cells. Notably, GADD45α overexpression ameliorated kidney damage and mitochondrial injury, leading to improved fatty acid β-oxidation, restored ATP production, and reduced ROS production. Transcriptomics analyses further demonstrated that GADD45α overexpression enhanced the expression of genes related to mitochondrial biogenesis, dynamics, and electron transport chain, with six transmembrane epithelial antigen of prostate 4 (STEAP4) being a key protein in this process. Knocking down STEAP4 using siRNA in HK-2 cells exacerbated the damage induced by high glucose. In addition, our further results indicated that high glucose increased methylation of the STEAP4 promoter, while GADD45α overexpression decreased methylation and increased STEAP4 expression.

Conclusions
Deficiency of GADD45α expression mediated tubulointerstitial injury in DN, which was mainly through the decreased STEAP4 expression by demethylating CpG motifs in the STEAP4 promoter region, thereby resulting in reduced fatty acid oxidation, energy synthesis, and increased ROS production, and finally accelerated tubular injuries. These findings suggested that targeting the GADD45α-STEAP4 pathway could be a potential therapeutic strategy for DN.
#489 UCP1 regulates cardiolipin metabolism and mediates mitochondrial homeostasis maintenance of ANXA1 in diabetic nephropathy
Authors: LI Zihan 
Published: May 2024

Abstract

Background and Aims
Diabetic nephropathy (DN) is accounted for a large proportion of chronic kidney disease (CKD) and is the leading cause of end-stage renal disease (ESRD) nowadays. The complex pathogenesis of DN has hindered the development of a single effective medicine, so it is of great significance to seek new therapeutic targets. Uncoupling of mitochondrial respiration by chemical uncouplers has proven effective in ameliorating obesity, insulin resistance, and hyperglycemia, which were risk factors for DN. Recently, we found that ANXA1 could improve mitochondrial function to mitigate DN progression. However, the underlying mechanism is not fully clear yet.

Method
We used kidney samples from patients in our hospital. ANXA1-KO mice with local renal overexpression of UCP1 were constructed, UCP1-KO mice were constructed for STZ/HFD modeling, and db/db mice were treated with CL316243. UCP1-KO mice with renal overexpression of CRLS1 were constructed. Mice with PTECs-specific deletion of ANXA1 were constructed. Cell lines with UCP1/ANXA1/GATA3 knockdown and UCP1/ANXA1/GATA3 overexpression were constructed, and cell reversal tests were performed using Ac2-26, CL316243 and siRNA targeting the above genes.

Results
Here, we identified uncoupling protein 1 (UCP1), an inner membrane protein of mitochondria, as a key to mitochondrial homeostasis improved by ANXA1. Specifically, ANXA1 attenuated mitochondrial dysfunction via appropriately upregulating UCP1 by stabilizing its transcription factor GATA binding protein 3 (GATA3) through combining with thioredoxin. Moreover, specific overexpression of UCP1 in renal cortex rescued renal injuries in diabetic Anxa1-KO mice. UCP1 deletion aggravated renal injuries in HFD/STZ-induced diabetic mice. Mechanistically, UCP1 reduced mitochondrial fission through the aristaless-related homeobox (ARX)/cardiolipin synthase 1 (CRLS1) pathway. Therapeutically, CL316243, a UCP1 agonist, could attenuate established DN in db/db mice.

Conclusion
Thus, our data unraveled specific mechanism by which UCP1 mediated mitochondrial homeostasis maintenance via the ANXA1-GATA3-UCP1-ARX-CRLS1 signaling pathway. This work established a novel principle to harness the power of uncouplers for the treatment of DN.
#1581 Anoctamin 3 inhibits gluconeogenesis and contributes to renal interstitial fibrosis through EZH2
Authors: Wu Ming , Lin Pinglan , Ye Chaoyang 
Published: May 2024

Abstract

Background and Aims
Renal fibrosis is the common pathological pathway of various chronic kidney diseases progressing to the end stage of renal failure. Anoctamin 3 (ANO3) has been identified as a K-channel regulator and been extensively studied in the field of neurobiology. The role of ANO3 in kidney diseases is currently unknown.

Method
Mouse models of renal fibrosis were established by unilateral ureteral obstruction (UUO) operation or aristolochic acid I (AAI) injection. Human proximal tubular cell line (HK2) was used as an in vitro model. ANO3 was deleted in vitro by siRNA. Western blotting analysis was performed. Glucogenic metabolites were measured.

Results
We found that ANO3 is upregulated in mouse kidneys with unilateral ureteral obstruction (UUO) or aristolochic acid nephropathy (AAN), and tightly correlated with the progression of renal fibrosis and negatively correlated with expression of several rate-limiting enzymes of renal gluconeogenesis. Knockdown of ANO3 with siRNA increased the concentration of glucose and reduced the concentration of lactate in the supernatant of TGF-β stimulated renal proximal tubular (HK2) cells. In parallel, transfection of ANO3 siRNA significantly reduced the expression of epithelial-to-mesenchymal transition (EMT) and fibrotic markers in TGF-β stimulated HK2 cells. We further showed that ANO3 expression is positively correlated with the expression of a methyltransferase enhancer of zeste homologue 2 (EZH2) in UUO and AAN mouse kidneys by time. Transfection of ANO3 siRNA significantly reduced the expression of EZH2 in TGF-β stimulated HK2 cells. Overexpression of EZH2 by adenovirus reversed the pro-gluconeogenic and anti-fibrotic effect of ANO3 siRNA in TGF-β stimulated HK2 cells by measuring the concentration of glucose and lactate in supernatant and analyzing the expression of EMT or fibrotic markers.

Conclusion
In conclusion, ANO3 inhibits renal gluconeogenesis through EZH2 and contributes to renal fibrosis. ANO3 could be promising therapeutic target to inhibit renal fibrosis in chronic kidney disease patients.
#273 Identification of epipin expression in progression of chronic kidney disease—a multi-omic approach
Authors: Kademani Sangeetha , Nelaturi Prabhudas , Sagar K Sathya , Sambandam Ravikumar 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease (CKD) is characterized by irreversible reduction in kidney function eventually leading to end-stage renal disease (ESRD). ESRD is a stage when kidney function is no longer adequate for long-term survival without dialysis or kidney transplant. Over the past the prevalence is increased more than 3 fold. Impaired activity of endogenous renal matrix-degrading proteases enhance interstitial matrix accumulation but specific pathways are involved remain unclear. Hence, an urgent need for sensitive biomarkers can detect disease earlier than traditional one and predict disease progression. Present study intended to identify epipin during chronic kidney disease and also we highlight promising kidney biomarkers that have robust underpinnings in the pathophysiology of kidney damage.

Method
A cross sectional study was conducted on patients with CKD compared with patients with diabetes mellitus (DM) and healthy controls. The collected samples were analyzed for the biochemical investigations included renal profile tests such as urea, serum creatinine, uric acid and urine spot test was analyzed for the screen of kidney problems. Firstly we identified the novel epipin protein through LC-MS then we estimated its gene expression levels using RT-PCR and levels of protein expression measured by ELISA.

Results
Epipin was shown higher expression in CKD compared to controls and moderately expressed in patients with diabetes mellitus compared to controls. The expression level of epipin gene was 4 fold in DM compared with controls, 19 fold in CKD compared with controls and 5 fold change between CKD and DM. Epipin showed AUC of 0.99 and 1.00 in DM and CKD respectively. The present study found that epipin was highly expressed in CKD patients and moderately expressed in patients with diabetes mellitus when compared to controls. In a present study, we identified one of the epipin with increased expression in renal disease progression.

Conclusion
The expression of epipin in virtually all samples suggests that this intracellular protein may have diverse and an extensive biological roles and may be an important therapeutic target for development of renal disease and its progression.
#2104 Neutrophil extracellular traps have a pivotal role in tubulointerstitial fibrosis
Authors: Cao Jingyuan , Hu Xinhui , Liu Haifei , Ni Weijie , Liu Hong 
Published: May 2024

Abstract

Background and Aims
Tubulointerstitial fibrosis (TIF) is a typical pathological change in chronic kidney disease (CKD). However, the mechanisms underlying tubulointerstitial fibrosis are still to be fully elucidated. Neutrophil extracellular traps (NETs) participate in the pathophysiological processes of various kidney diseases, but their role in CKD-TIF has not been reported. Here, we investigated the role of NETs in tubulointerstitial fibrosis.

Method
Immunofluorescence was employed to assess the levels and localization of NETs in the renal tissues of CKD patients. The GSE66494 human CKD microarray dataset was explored to analyze the changes of PAD4 levels. Three CKD mice models, including 14d unilateral ureteral obstruction (UUO), 28d ischemia/reperfusion (I/R) injury, and adenine-induced models were constructed to detect the expression levels of NETs in the kidneys. Then, we established a NETs-deficient (PAD4−/−) CKD mice model and assessed changes in renal function, NETs levels, and renal fibrosis. In vitro, phorbol-12-myristate-13-acetate (the classic inducer of NETs) was used to induce the generation of NETs. Intervention was performed on rat fibroblast NRK49F cells to investigate the mechanism of TIF induced by NETs.

Results
We first identified NETs levels were significantly elevated in the renal tissues of CKD patients. Additionally, chip data results also indicated elevated PAD4 levels in the renal tissues of CKD patients. NETs levels were elevated in the kidneys of UUO, I/R, and adenine-induced CKD mice, with deposition in the renal interstitium. PAD4-deficient mice did not form neutrophil extracellular traps. Knocking out PAD4 alleviated tubulointerstitial fibrosis in UUO, adenine, and I/R mice after blocking NETs formation. In vitro, NETs intervention in fibroblasts can promote their activation and transformation into myofibroblasts.

Conclusion
The deletion of NETs by PAD4−/− could significantly improve CKD-TIF. The inhibition of NETs might provide a new molecular target for the prevention and treatment of CKD.
#2592 Tubular cell polyploidy is involved in kidney compensatory hypertrophy
Authors: De Chiara Letizia , Lazzeri Elena , Romagnani Paola 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease (CKD) affects more than 10% of the population and it is associated with high risk of death for cardiovascular causes or progression towards end stage kidney disease (ESKD) requiring dialysis or kidney transplantation. CKD is characterized by progressive loss of nephrons, with consequent structural degeneration and fibrosis. Nephron number is established during prenatal kidney development and cannot increase. Consequently, following a reduction in kidney mass or in condition of altered metabolic demands, the remaining nephrons undergo compensatory hypertrophy. Compensatory hypertrophy results in increased functional output and has been observed in the absence of direct tissue injury after nephrectomy. Recently, we have identified a previously unknown mechanism of cellular adaptation: polyploidization of tubular epithelial cells (TC), and demonstrated that this is the essential mediator of kidney hypertrophy after acute kidney injury (AKI). Here, we hypothesize that TC polyploidy is involved in compensatory hypertrophy following nephrectomy.

Method
Polyploid TC are characterized by an increased DNA content in the absence of cell division. To discriminate polyploid cells from actively proliferating cells, we employed a series of in vitro and in vivo transgenic models based on the Fluorescence Ubiquitin Cell Cycle Indicator (FUCCI2aR) technology. Nephrectomy was performed by removing the left kidney and mice were sacrificed at different days after uni- Nephrectomy (Nfx). Cytofluorimetric techniques were employed to characterize a subpopulation of polyploid TC and histology investigation was employed analyze fibrosis development. These results were further corroborated by single cell RNA-sequencing (scRNA-seq) analyses in vitro and in vivo.

Results
Employing mice that express the FUCCI2aR reported under the Pax8 promoter (which marks all TC), we found that TC polyploidy increases immediately after uni-Nfx. This was accompanied by an increased kidney to body mass ratio with a maximum peaks 3 days afterwards. Importantly, after uni-Nfx, YAP1 expression and nuclei localization (i.e., implying pathway activation) was exponentially increased, suggesting that the same mechanism that drives TC polyploidy after AKI controls TC polyploidization response after uni-Nfx. However, unlike in AKI, polyploidy after nephrectomy was not accompanied by structural alterations as shown by PAS and Masson's trichrome staining. Conversely, after uni-Nfx YAP1 knock-out mice, that are unable to undergo rapid polyploidization, displayed an impaired kidney function in the long term, characterized by extensive tubular dilations.

Conclusion
Polyploidization of TC mediates compensatory hypertrophy following nephrectomy via YAP1 activation
#2641 MiR-200b induces ZEB1 mediated upregulation of Matriptase and affects expression of podocin
Authors: Tati Ramesh , Müller-Deile Janina , Walentinsson Anna , Sopel Nina , Lassen Emelie , Ebefors Kerstin , Söderberg Magnus , Daniel Christoph , Hansen Pernille B L , Schiffer Mario , Nystrom Jenny , Buvall Lisa 
Published: May 2024

Abstract

Background and Aims
Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and a predominant reason for renal failure. Evidence from previous research indicates that abnormal expression of microRNAs (miRs) links closely to the occurrence and progression of DKD.

Methods
Expression of miRs in urine samples from DKD patients and in cultured renal cells stressed with transforming growth factor beta 1 (TGF-β1) was evaluated by TaqMan assay. The emerging miR of interest and its downstream targets were analyzed in human renal sections, in cultured human podocytes and in zebrafish.

Results
Cell free urine screening showed increased abundance of miR-200b in samples from patients with DKD when compared to healthy controls. In situ hybridization confirmed expression of miR-200b in kidney specimens from DKD patients, but was not detected in healthy renal parenchyma. Transcriptome profiling of cultured human podocytes overexpressing miR-200b identified this miR as a regulator of the ZEB1 mediated matriptase (ST14)/ podocin pathway and found TGF- β1 stress to be upstream activators of miR-200b expression in these cells. Immunofluorescence analysis of kidney sections from DKD patients showed increased expression of ST14 and decreased expression of podocin when compared to healthy controls. Furthermore, injection of a miR-200b mimic in zebrafish larvae caused an upregulation of ST14 and was accompanied by phenotypic changes such as edema, proteinuria and podocyte effacement.

Conclusion
Our results show that miR-200b is expressed in glomeruli and found at elevated levels in urine of DKD patients. Overexpression of miR-200b in cultured podocytes and in zebrafish induces upregulation of matriptase, a serine protease previously shown to cleave podocin. The observed increase in matriptase and decrease in podocin levels in glomeruli from DKD patients, together with the effect of a miR-200b mimic on proteinuria and ultrastructure of the pronephros in zebrafish positions miR-200b as a key regulator that modulates matriptase overactivation in DKD and warrants further studies.
#613 Is there a relationship between kidney stiffness identified by 2D shear wave elastography and the estimated glomerular filtration rate?
Authors: Maralescu Felix-Mihai , Raimann Jochen G , Schiller Adalbert , Petrica Ligia , Bob Flaviu 
Published: May 2024

Abstract

Background and Aims
Ultrasound-based elastography has been utilized as an imaging method with high utility in the liver or thyroid, but it is not yet being implemented in evaluating the chronic kidney disease (CKD) because current research indicates a high level of heterogeneity between studies. We aimed to investigate if there is a connection between kidney stiffness measured with a new, specially designed elastography software for kidneys and estimated glomerular filtration rate (eGFR).

Method
In 2022 and 2023 we performed a cross-sectional study in 150 participants (50 healthy, 50 kidney-transplanted, 50 with chronic glomerulonephritis). The mean value of five different measurements for each kidney were correlated with biological and clinical parameters. To examine the variations amongst the three groups, one-way between-groups ANOVA was employed.

Results
The mean kidney stiffness for the healthy cohort was 31.9 ± 2.9 kiloPascal (kPa), for kidney transplanted (Ktx) patients 25.9 ± 6.9 kPa and for the chronic glomerulonephritis (GN) 23.8 ± 7.45 kPa. We discovered correlations between kidney stiffness and eGFR in all three groups: healthy r = 0.61, p &lt; 0.0001, Ktx r = 0.56, p &lt; 0.0001, GN r = 0.70, p &lt; 0.0001.
We also found a value of under 26 kPa for the detection of an eGFR under 60 mL/min/1.73 m2 with 94.3% sensitivity and 84% specificity (AUC = 0.905, p &lt; 0.0001). The healthy group showed significant higher values than Ktx or GN groups, but without significant differences between the latter two.

Conclusion
Our findings demonstrate a correlation between renal function, with very good diagnostic accuracy, and these novel imaging techniques. A decrease in renal stiffness with the progression of CKD could prove to be an easy, reproducible approach to provide additional diagnostic information. However, given the limited number of participants, additional studies are required before they can be incorporated into standard clinical practice.