bluuebunny/crossref_metadata_2025_split huggingface dataset:
#886 Prevalence and prognostic relevance of electrocardiographic abnormalities among patients with ANCA-associated vasculitis
Authors: Nygaard Louis , Liboriussen Caroline Hundborg , Carlson Nicholas , Nelveg-Kristensen Karl Emil , Kristensen Salome , Kragholm Kristian , Graff Claus , Torp Christian , Ivarsen Per , Svensson My , Gregersen Jon Waarst , Polcwiartek Christoffer 
Published: May 2024

Abstract

Background and Aims
Cardiovascular disease (CVD) is one of the leading causes of death in patients with ANCA-associated vasculitis (AAV). However, in current clinical guidelines, limited evidence is available to support the recommendation of AAV-specific screening for cardiovascular comorbidities. This study reported the prevalence of electrocardiogram (ECG) abnormalities and investigated associations between ECG abnormalities and fatal CVD in a validated cohort of patients with AAV compared to matched controls.

Method
Based on a retrospective matched cohort design, patients with granulomatosis with polyangiitis [ICD-10: DM31.3] or microscopic polyangiitis [ICD-10: DM3.17] and accessible ECGs were identified in nationwide Danish health care registers from 2000 to 2021. Patients with AAV were matched 1:3 on age, sex, and calendar year of ECG measurement with controls without AAV. Index date was defined as the date of ECG measurement. ECGs were hierarchically categorized as either no, minor, or major ECG abnormalities according to contemporary literature. The associations between ECG abnormalities and fatal CVD were assessed in multiple Cox regression models adjusted for age, sex, and comorbidities. Counterfactual G-estimation of hazard ratios (HRs) standardized to age and sex was performed to estimate the 5-year absolute risk (AR) of fatal CVD according to ECG-abnormalities.

Results
A total of 1431 patients with AAV were matched to 4293 controls. The median age of patients with AAV and matched controls was 69 (IQR 58-77) years, and 52.3% were males. Median study follow-up time was 4.8 (IQR, 2.7-7.8) years. AAV was associated with increased prevalence of left ventricular hypertrophy (17.5% vs. 12.5%, p &lt; 0.001), ST-T deviations (10.1% vs. 7.1%, p &lt; 0.001), atrial fibrillation (9.6% vs. 7.5%, p = 0.017) and corrected QT prolongation (5.9% vs. 3.6%, p &lt; 0.001) compared to controls. When examining associations of fatal CVD across no, minor or major ECG abnormalities, only the patients with AAV and major ECG abnormalities had a higher risk of fatal CVD [HR 1.99 (95% CI, 1.49-2.65)], compared to matched controls. This corresponded to a significantly higher standardized 5-year AR of fatal CVD compared to controls: 19.14% (95% CI, 16-22%) vs. 9.41% (95% CI, 8-11%).

Conclusion
AAV was associated with a higher prevalence of major ECG abnormalities such as left ventricular hypertrophy, atrial fibrillation, and ST-T deviations compared to matched controls. Moreover, the patients with AAV demonstrating major ECG abnormalities had a particularly elevated risk of fatal CVD. This indicates that AAV patients with major ECG abnormalities are a distinct high-risk group within AAV patients prone to cardiovascular-related mortality.
#634 Prognosis is still poor in patients with posttransplant C3 glomerulopathy: a multicenter cohort
Authors: Mirioglu Safak , Hocaoglu Rabia Hacer , Velioglu Arzu , Ozluk Yasemin , Dirim Ahmet Burak , Oruc Aysegul , Oto Ozgur Akin , Yazici Halil , Caliskan Yasar 
Published: May 2024

Abstract

Background and Aims
Data on patients with posttransplant recurrent or de novo C3 glomerulopathy (C3G) are limited. We therefore aimed to analyze features and outcomes of patients developed posttransplant C3G.

Method
In this retrospective multicenter study conducted across 3 centers, we collected the data of kidney transplant recipients (KTRs) who were diagnosed with posttransplant recurrent or de novo C3G between 2014-2023 and followed for at least 3 months after the diagnosis. Demographic, clinical, laboratory and histopathological characteristics of patients were retrieved from the databases of participating centers. Primary outcome was defined as death-censored graft loss necessitating dialysis or re-transplantation, and secondary outcome was complete (CR) or partial remission (PR). CR was the recovery of baseline eGFR and proteinuria of &lt;0.5 g/g. PR was ≥50% reduction of proteinuria (and to &lt;3 g/g in patients with nephrotic-range proteinuria at baseline) plus stabilization or improvement in kidney function.

Results
Eleven patients were identified, and 10 with follow-up data were included. Detailed features of patients were shown in the Table. Five (50%) were male, and mean age at the time of transplantation (KTx) was 33.2 ± 8.5 years. Nine KTRs (90%) were diagnosed with recurrent C3G and the etiology of primary kidney disease was not known in one patient. Majority of KTx were performed from living donors (9.90%). One patient had a history of T-cell mediated rejection before posttransplant C3G, which had showed good response to anti-rejection treatment. Posttransplant C3G was diagnosed after a median of 26 (3-85) months after KTx, and mean age was 36.8 ± 9.1 years. Mean hemoglobin, serum creatinine, serum albumin, and proteinuria at the time of diagnosis were 10.5 ± 1.8 g/dl, 1.9 ± 0.7 mg/dl, 4.1 ± 0.5 g/dl, and 1.1 ± 0.9 g/g, respectively. Monoclonal disorders were excluded by using serum and urine electrophoresis and serum free light chain assays in all KTRs. Serum C3 was low (67.1 ± 29.7 mg/dl, ref: 90-180 mg/dl) in 7 of 8 KTRs with available data (87.5%). Further immunosuppressive treatment was administered in 9 cases. Eculizumab was used in 8, and 1 patient was treated with pulse steroids and therapeutic plasma exchange. Median duration of treatment was 14.5 (3-24.3) months. Four patients (44.4%) who were treated with eculizumab showed CR. After a median of 32 (9.5-82) months, 5 KTRs (50%) experienced graft loss despite eculizumab use in 3 of them. No adverse events attributed to treatment were observed.

Conclusion
Prognosis is still quite dismal in patients with posttransplant C3G despite the use of eculizumab. Better treatment options are urgently needed.
#753 Targeted anti-IL-1β bacteroides fragilis outer membrane vesicles alleviate inflammatory injury in diabetic nephropathy
Authors: LI Liang , LI Xue Qi , Zhang Jia Xiu , Wu Qin Yi , MA Kun Ling 
Published: May 2024

Abstract

Background and Aims
It is accepted that diabetic nephropathy (DN) is not only a disease caused by impaired glucose metabolism, but also a chronic inflammatory disease. The interleukin-1β (IL-1β) plays an important role in inflammation-mediated renal injury in DN. IL-1β blocking therapy can prevent inflammatory cytokine-mediated kidney injury. However, the high cost and systemic side effects of IL-1β antibodies limit its application. Therefore, firstly this study aimed to construct kidney-targeting outer membrane vesicles (OMVs) of Bacteroides fragilis loaded with IL-1β single-chain variable fragment (scFv). These OMVs derived from human commensal non-toxigenic Bacteroides fragilis have been proven to play an immunosuppressive role in the intestine and distant organs. This targeted drug delivery platform built with this as a carrier is expected to relieve kidney inflammation in the development of DN.

Methods
We recombinantly expressed the scFv based on the Gevokizumab sequence in Escherichia coli, and loaded it into the OMVs derived from Bacteroides fragilis by multiple ultrasounds. The targeting peptide with the sequence (KKEEE)3{Lys(N3)} was connected to the membrane surface through a copper-free catalyzed click chemistry reaction. The package, which consisted of OMVs and the scFv targeting IL-1β in the kidney (OMV-KTP-scFv) was obtained. OMV-KTP-scFv treated in HK-2 cells and healthy mice respectively, and evaluated its in vitro and in vivo drug safety. The concentration of IL-1β scFv in blood and kidney tissues at different time points were measured using streptozotocin (STZ)-induced diabetic mice. DID-labeled OMVs was used for ex vivo infrared imaging of various organs to evaluate the delivery efficiency of the targeted carrier. In vitro, OMV-KTP-scFv was used to prevent inflammation in mouse primary renal tubular epithelial cells induced by high glucose, and in vivo to alleviate kidney injury in STZ-induced diabetic mice.

Results
We successfully prepared OMV-KTP-scFv and confirmed the co-localization of OMVs, KTP, and scFv using super-resolution microscopy. The prepared OMV-KTP-scFv had high stability, effectively extended the plasma half-life of scFv, and could deliver scFv accurately to the proximal renal tubules. Furthermore, OMV-KTP-scFv also had good safety in vitro and in vivo, and no obvious biotoxicity was found during long-term in vivo administration. In addition, our results show that OMV-KTP-scFv significantly inhibited the expression of inflammatory factors in renal tubular cells of DN, reduced the infiltration of renal interstitial inflammatory cells, and alleviated renal tubular injury.

Conclusion
Our findings demonstrated that OMVs of Bacteroides fragilis targeting the kidney can deliver the IL-1β scFv to the renal tubulointerstitium and reduce the renal interstitial injury in DN by antagonizing local inflammation.
#894 Dynamic multi-omics and mechanistic modelling approach provides deeper insight into kidney fibrosis progression
Authors: Tuechler Nadine , Burtscher Mira Lea , Rodriguez-Cordoba Martin Garrido , Khan Muzamil Majid , Turei Denes , Kramann Rafael , Merten Christoph A , Rodriguez Julio Saez , Pepperkok Rainer 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease (CKD) affects more than 10% of the world's population and causes millions of deaths annually. Organ fibrosis is the main driver of CKD, leading to excessive accumulation of extracellular matrix (ECM). The presence of myofibroblasts correlates with disease progression. The pro-fibrotic responses of these cells, such as ECM production, are driven by the master regulator TGF-β. Despite progress in understanding the disease, there are no treatments available, and current diagnostic indicators neither facilitate early detection of CKD nor correlate with actual renal damage [1–4] Using human kidney-derived PDGFRβ+ mesenchymal cells we aim to provide time-resolved mechanistic insight into CKD progression.

Method
Our goal is to understand and model how these cells contribute to fibrosis by studying their kinetic response to TGF-β. Therefore, we use multiple omics measurements: transcriptomics, secretomics and phospho-/proteomics coupled with quantitative imaging of the ECM. For each time point, we quantified differential changes in omics and estimated the activities of transcription factors, kinases and phosphatases [5]. Furthermore, we used causal reasoning to draw mechanistic relationships between omics layers within and across time points.

Results
For validation, we focused on a set of transcription factors that also showed importance in the network context that considers several data modalities. Using knock-down experiments, we show the relevance of these transcription factors for the ECM deposition as well as the fibrotic response to TGF-β.

Conclusion
Taken together, by applying mechanistic modeling and the integration of multiple datasets, we are contributing to a better understanding of the factors and mechanisms driving kidney fibrosis. Furthermore, we will publish this dataset and thus provide a valuable resource for researchers in the field of CKD.
#1344 Molecular signatures of assembloids generated from stem cell derived nephron progenitors and ureteric bud cells as potential kidney organoid therapy
Authors: Woollard Kevin , Graneli Cecilia , Larsson Susanna , Petrillo Federica , Hong Xuechong , Holmgren Gustav , Vaithilingam Vijay , Söderberg Magnus , Sini Marcella , Stauske Michael , Wigge Leif , Hansen Pernille B L 
Published: May 2024

Abstract

Background and Aims
Novel therapies are needed to address the unmet clinical need of patients suffering from end stage kidney disease (ESKD) and cell therapy is an innovative strategy to deliver effective, curative treatment options to renal patients. There are several reports that have developed protocols to differentiate human pluripotent stem cells (hPSCs) into kidney-lineage progenitor derived organoid models and we have developed a robust and scalable method to produce kidney organoids.

Method
hPSCs were used to generate nephron progenitor cells (NPCs) and ureteric bud cells (UB) through previously described stem cell differentiation protocols. NPCs on day 9 of differentiation and UB on day 9 were combined for 2 days at 3:1 ratio respectively, to form ‘assembloids’ in-vitro and implanted in-vivo for 2 weeks. We used kidney capsule implantation in a NOD background mouse model and studied integration and phenotype using micro-CT and immunohistochemistry.

Results
RNA sequencing, flow cytometry and histology of NPCs, UB and assembloids in vitro shows broad representation of renal cell types by expression of markers representing several cell populations present in the developing nephron. We can currently show in-vitro molecular signatures of NPC derived organoids versus assembloids, with superiority of UB derived structures such as connecting tubules and intercalated cells. In-vivo histological examination of implanted assembloids showed maturation of human renal compartments such as collecting ducts, distal tubules as well as glomeruli-like structures. Micro-CT analysis showed integration with host and host derived endothelial vascularisation.

Conclusion
These observations demonstrate the use and differentiation potential of hPSCs and organoids in a pre-clinical setting towards more functional like kidney compartments by combining different progenitor populations. More work is needed evaluating these and other renal progenitor populations for future efforts to examine efficacy studies to develop regenerative therapies for ESKD.
#1322 VEGF therapy improves cardio-renal pathophysiology in a novel model of CKD-HFpEF
Authors: Chade Alejandro , Sitz Rhys , Mccarthy Elizabeth , Tharp Darla , Bidwell Gene , Eirin Alfonso 
Published: May 2024

Abstract

Background and Aims
Patients with chronic kidney disease (CKD) have a higher risk of developing heart failure with preserved ejection fraction (HFpEF). We developed a model of CKD-HFpEF and showed that renal-cardio pathophysiology is associated with decreased expression and availability of vascular endothelial growth factor in both organs. We showed that renal VEGF therapy improved renal function in our model. We hypothesize that cardiac VEGF therapy will improve cardiac function and will investigate whether cardiac protection in CKD also carries recovery of renal function.

Method
CKD and normal pigs (n = 4 each, 2 males/2 females) were studied for 14 weeks. In addition, CKD-HFpEF (n = 4, 2 males/2 females) were treated after 6 weeks of disease with a single intracoronary (IC) administration of VEGF attached to a drug-delivery vector (ELP-VEGF) that increases cardiac targeting, and effects quantified 8 weeks later. Renal (multi-detector CT) and cardiac (echocardiography, PV loops) morphology and function were quantified in vivo, microvascular (MV) density (3D micro-CT) ex vivo, and cardiac expression of VEGF was quantified by qPCR.

Results
Cardiac function, VEGF expression, and MV density were improved after IC ELP-VEGF therapy compared to placebo. Notably, renal hemodynamics (expressed as % change) were significantly improved compared to pre-treatment values and to time-matched untreated CKD-HFpEF pigs (Figure).

Conclusion
Our study suggests strong crosstalk between the heart and the kidney in a pre-clinical model of CKD-HFpEF. Renal and cardiac hemodynamics were significantly improved after cardiac VEGF therapy, conceptually supporting a cardio-renal axis in CKD and showing the extent of beneficial effects of a novel targeted intervention in a translational fashion.
#1451 Calcimimetics reduce the progression of high-phosphate diet-induced tubular damage
Authors: Walles Franziska , Richter Beatrice , Weingärtner Nina , Schmitz Jessica , Bräsen Jan Hinrich , Haffner Dieter , Leifheit-Nestler Maren 
Published: May 2024

Abstract

Background and Aims
During chronic kidney disease (CKD) progresses, there is an increased phosphate load and the concentration of the phosphaturic hormones PTH and FGF23 rises. In patients, phosphate and FGF23 are discussed as risk factors for CKD progression. We have recently shown that mice with high phosphate, PTH and FGF23 levels develop Stat3/Kim-1-mediated proximal tubule damage and tubulointerstitial fibrosis associated with increased MCP-1 expression and accumulation of macrophages. Calcimimetics lower PTH and FGF23 levels in hemodialysis patients and are thought to have both cardio- and nephroprotective effects. In a preclinical study, cinacalcet was shown to stabilize podocyte function in proteinuric mice. Therefore, we postulate that calcimimetics also have a positive effect on the progression of tubular damage in mice with high phosphate, PTH and FGF23 levels.

Method
For the induction of phosphaturic hormones with concomitant tubule damage, male C57BL/6 mice were fed a 2.0% high phosphate diet (HPD) and compared to animals on a 0.8% control phosphate diet (CPD). After four months, one HPD group was additionally treated with 1 mg/kg body weight/day etelcalcetide (KP-2326). Six months after the start of the trial, blood and urine samples as well as kidneys were taken for biochemical, histological and molecular biological examinations.

Results
KP-2326 treatment reduced HPD-induced PTH and FGF23 levels, but had no effect on increased phosphate excretion or elevated serum phosphate levels. Histologically, tubular damage was not as pronounced in the KP-2326-treated HPD animals as in the HPD group without therapy. The increased BUN levels caused by HPD and the albuminuria were significantly reduced by KP-2326. KP-2326 reduced HPD-mediated activation of Stat3 in proximal tubule cells and decreased Kim-1 synthesis at both mRNA and protein levels. Moreover, KP-2326 significantly reduced the mRNA expression of Ccl2 and the macrophage-specific marker Adgre1 compared to the untreated HPD group, which was histologically reflected in a lower accumulation of F4/80+ macrophages around the damaged tubules.

Conclusion
Treatment with KP-2326 was able to reduce the progression of HPD-induced tubule damage, at least in part due to the reduction in PTH and FGF23 levels.
#1116 Hyperuricemia worsens bacterial sepsis by suppressing neutrophil functions in CKD
Authors: LI Qiubo , Flora Kailey , Ehreiser Louisa , Steiger Stefanie 
Published: May 2024

Abstract

Background and Aims
Patients with kidney disease, especially those on dialysis, are more susceptible to infections such as peritonitis, sepsis, pneumonia, and are at a higher risk for infection-related mortality. Pathogenic mechanisms underlying the secondary immunodeficiency in kidney disease include gut dysbiosis and barrier dysfunction, persistent inflammation, immune paralysis due to increased levels of immunoregulatory metabolites (e.g. uric acid) and proteins (e.g. FGF23) [1]. Currently, it is unknown whether CKD-related hyperuricemia may contribute to the immune paralysis in this context. We hypothesized that hyperuricemia (HU) may aggravate the innate immune response to infection in CKD in mice.

Method
Mono- and polybacterial sepsis was induced by LPS injection or cecal ligation and puncture in Alb-creERT2;Glut9lox/lox mice with HU and/or CKD, and in Glut9lox/lox (healthy) control mice. After 24 hours, systemic inflammation was evaluated by measuring serum cytokine levels, immune cell activation and recruitment, and neutrophil extracellular trap release. Tissue injury in liver, heart, and kidney was assessed by performing RT-qPCR and immunohistochemistry. In addition, kidney function was determined by measuring the glomerular filtration rate (GFR). Additionally, mice were treated with urate-lowering therapy to reduce serum uric acid levels and the immune response and functional outcomes after sepsis is quantified.

Results
We found that both mono- and polybacterial sepsis caused systemic inflammation as indicated by an increased number of blood neutrophils (see Figure), neutrophil activation and pro-inflammatory cytokine levels as compared to the PBS-treated or sham-operated control groups in Glut9lox/lox healthy mice, respectively. Mice with sepsis also displayed a slightly worsened kidney function. Interestingly, HU significantly increased neutrophil numbers but decreased their activation status and the ability of neutrophils to form neutrophil extracellular traps in Alb-creERT2;Glut9lox/lox mice with sepsis as compared to the control groups, which was further aggravated in mice with CKD-related HU (CKD+HU). This impaired inflammatory response was partially reversible by lowering serum uric acid with febuxostat.

Conclusion
Our results identify hyperuricemia related or unrelated to kidney disease as immune regulator in bacterial infection by suppressing neutrophil functions in mice. Specifically targeting uric acid may help to overcome the secondary immunodeficiency related to kidney disease during infection but enhances sterile inflammation [2].
#2036 Mitochondrial copper overload promotes renal fibrosis via inhibiting pyruvate dehydrogenase activity
Authors: Zhu Saiya , Yu Chen 
Published: May 2024

Abstract

Background and Aims
Copper is a trace element essential for numerous biological activities, whereas the mitochondria serve as both major sites of intracellular copper utilization and copper reservoir. Pyruvate dehydrogenase complex (PDHC) is a rate-limiting enzyme of glucose oxidation in mitochondrial matrix, converting pyruvate into acetyl-CoA and linking glycolysis to tricarboxylic acid (TCA) cycle. Dihydrolipoamide acetyltransferase (DLAT), the E2 component of the PDHC, requires lipoylation for enzymatic function and exhibits a high affinity for copper within its lipoyl moiety. Here, we investigated the impact of mitochondrial copper overload on the tricarboxylic acid cycle and renal senescence and fibrosis.

Method
Molecular dynamics simulation was used to explore the effect of copper ions on lipoylated DLAT protein. ICP-MS was used to detect copper content in mitochondria. Western blotting was used to detect the level of lipoylated DLAT dimer. Enzyme biopsy test kit, electron microscopy, mitoSOX Red staining and ATP content detection were used to evaluate mitochondrial function. Detect Collagen I, α-smooth muscle actin (α-SMA) expression levels and Masson staining to explore renal fibrosis. To reduce mitochondrial copper level, we used lentivirus to downregulate CRT1 expression or copper chelator tetrathiomolybdate in renal tubular epithelial cells (NRK-52E), and used CTR1 knockdown transgenic mice or tetrathiomolybdate in vivo.

Results
We found that copper ion levels are significantly elevated in the mitochondria in fibrotic kidney tissues, which are accompanied by reduced pyruvate dehydrogenase (PDH) activity, mitochondrial dysfunction, cellular senescence and renal fibrosis. Conversely, lowering mitochondrial copper levels through knocking-down of copper transporter 1 or treatment with the copper chelator tetrathiomolybdate effectively restore PDH enzyme activity, improve mitochondrial function, and mitigate cellular senescence and renal fibrosis. Mechanically, we found mitochondrial copper binds directly to lipoylated dihydrolipoamide acetyltransferase (DLAT), thereby changing the interaction between protein subunits, inducing lipoylated DLAT protein dimerization, and ultimately inhibiting PDH enzyme activity.

Conclusion
Our study indicates that mitochondrial copper overload could inhibit PDH activity, subsequently leading to mitochondrial dysfunction, cellular senescence and renal fibrosis. Reducing mitochondrial copper overload might therefore serve as a strategy to rescue renal fibrosis.