bluuebunny/crossref_metadata_2025_split huggingface dataset:
NHERF1 loss results in metabolic stress and increased susceptibility to cisplatin‐induced acute kidney injury
Authors: Bushau‐Sprinkle Adrienne Marie , Barati Michelle , Conklin Caryl , Dupre Tess , Gagnon Kenneth B. , Siskind Leah , Doll Mark , Rane Madhavi , Clark Barbara , Merchant Michael , Klinge Carolyn , Brier Michael , Coventry Susan , Lederer Eleanor 
Published: June 2021

BackgroundAcute kidney injury (AKI) is associated with a high mortality rate and develops in 30% of patients who receive cisplatin. The sodium hydrogen regulatory factor isoform 1 (NHERF1) is a scaffolding protein that anchors multiple membrane proteins, in renal proximal tubules. We have recently demonstrated that NHERF1 loss results in changes in mitochondrial protein abundance and function.HypothesisWe hypothesize that NHERF1 loss increases susceptibility to AKI through an underlying metabolic stress.Materials and MethodsWe treated 2 month old male and female wild type (WT) C57BL/6 and NHERF1 knock out (KO) mice with vehicle (VEH) or cisplatin (CIS) (20 mg/kg dose IP) and euthanized after 72 hours. Blood was collected for blood urea nitrogen (BUN) levels. Urine was collected for NGAL. Kidneys were harvested for histology, TUNEL assay, and Western Blot for cleaved caspase 3. Proteomic analysis was conducted on kidney brush border membrane (BBM) of WT and KO kidneys. Metabolic measurements were conducted via the XF Flux analyzer on non‐treated primary proximal tubule cell cultures. Three‐way ANOVA was used to compare the different treatment groups. Ordinal regression was performed for the semi‐quantitative scoring. All statistical analysis was conducted with SPSS software. P values of <0.05 were considered statistically significant.ResultsCIS caused significantly greater severity of kidney injury in KO compared to WT mice by semi‐quantitative injury score (WT: 1.89, KO: 2.8), BUN levels (WT: 97.8 mg/dL +/− 10.1, KO: 151.8 mg/dL +/− 17.2) and NGAL protein (WT: 2.7 μg/mL +/− 0.53, KO: 55.6 μg/mL +/−21.3). Apoptosis markers were significantly increased in CIS treated KO and WT mice compared to respective controls. Proteomic comparison of BBM protein expression in WT and KO showed marked changes in the expression of mitochondrial proteins in KO mice, suggesting alterations in cell metabolism. KO proximal tubule cells also exhibited decreases of 35% in glycolytic reserve capacity, 40% in baseline mitochondrial respiration rate, 37% in ATP‐linked mitochondrial respiration rate, 40% in mitochondrial reserve capacity, and 40% in maximum mitochondrial capacity.ConclusionsWe conclude that the KO mice have increased susceptibility to CIS‐induced AKI, which may be due to altered metabolism and/or mitochondrial dysfunction.Support or Funding InformationFunding for this research was provided by VA and UofL School of Medicine (to EDL).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
AKI to CKD Transition is driven by Alpha 2 Adrenergic Receptors
Authors: Jang Hee‐Seong , Padanilam Babu 
Published: June 2021

BackgroundEnhanced tissue level and activity of norepinephrine (NE) have been recognized as risk factors of development and progression of chronic kidney disease (CKD). Our reports showed renal denervation (DNx) can prevent renal fibrosis and inflammation in renal fibrogenesis models. However, the underlying mechanism by which renal DNx prevents the long‐term sequelae of acute kidney injury (AKI) remains to be elucidated.MethodsBased on our published data, we hypothesized that NE mediates its effect through activation of alpha 2 adrenergic receptors (α2‐ARs). In this study, we investigated whether genetic and/or pharmacological inhibition of α2‐ARs prevents ischemia/reperfusion injury (IRI)‐induced inflammation and CKD progression.ResultsRenal bilateral IRI resulted in severe kidney fibrosis in medullary region over 2 weeks with persistent tubular injury and massive macrophage infiltration. Renal DNx suppressed renal inflammation, tubular damage, and fibrosis progression, as well as increase in blood pressure, 2 weeks post‐IRI. Pharmacological inhibition of α2‐AR also inhibited fibrosis progression with reduced downstream targets of NE‐α2‐AR axis, including angiotensinogen and fibrogenic factors. Consistent with results in renal DNx and pharmacological inhibition of α2‐AR, inhibition of α2A‐ and α2C‐AR subtypes by pharmacological or genetic manipulation additively prevented macrophage accumulation with downregulation of M1 and M2 macrophage markers, resulting in suppression of persistent renal tubular injury and fibrosis progression.ConclusionTaken together, blockage of α2‐AR subtypes prevents IRI‐induced AKI to CKD transition through inhibition of macrophage accumulation, persistent renal tubular injury and fibrosis progression, suggesting that targeting α2‐ARs may be a potential therapeutic strategy to prevent long‐term sequelae of ischemic AKI.Support or Funding InformationThis work was supported by NIH DK‐083291 and DK‐090332 and UNMC College of Medicine Bridge fund.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Trehalose attenuates mitochondrial dysfunction in cisplatin‐induced acute kidney injury by activating autophagy
Authors: Zhu Lingling , Yuan Yujia , Li Hongxia , Chen Younan , Lu Yanrong , Cheng Jingqiu 
Published: June 2021

ObjectiveCisplatin, an anticancer drug, always lead to nephrotoxicity via causing mitochondrial dysfunction. As a major catabolic pathway, autophagy has been proved that could protect against cisplatin‐induced acute kidney injury (AKI). Base on the activation of autophagy induced by trehalose, we aimed to investigated whether trehalose could alleviate mitochondrial dysfunction and kidney injury in mice though autophagy‐lysosome mediated clearance of damaged mitochondria.MethodsMice were administered a single intraperitoneal (i.p.) injection of cisplatin 16mg/kg to induce AKI, then mice were treated with PBS or trehalose (i.p.). In vitro, HK2 cells were treated with cisplatin 16mg/kg in the presence or absence of trehalose. To evaluate mitochondrial bioenergetic, mitochondrial morphology, membrane potential and ATP content were detected.ResultsIn vivo, comparing with the normal mice, BUN and Crea were significantly increased in AKI mice, while decreased after the treatment with trehalose, indicating that trehalose could alleviate kidney injury in AKI mice. In vitro, along with the activation of autophagy (elevated expression of LC3 II and ATG5), mitochondrial fragmentation, depolarization, and reduced ATP generation induced by cisplatin were markedly inhibited in trehalose‐treated HK2 cells. Moreover, the double immunofluorescence staining results showed that the co‐localization between mitochondria and LC3 was increased, indicating that the mitophagy was induced. In addition, we found that the protective effect of trehalose was largely abolished when the autophagy process was inhibited by HCQ.ConclusionThese results indicated that trehalose can ameliorate cisplatin‐induced mitochondrial dysfunction by activating autophagy, and thus it might be a promising therapy to acute kidney injury.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Involvement of Tubular Mas Receptor in Lipid‐Induced Impaired Autophagy and ER Stress in the Kidney
Authors: Kong YongLun , Zhao Xiaoduo , Li Suchun , Qiu Miaojuan , Lin Yu , Li Chunling , Wang Weidong 
Published: June 2021

The local renin‐angiotensin system in the kidney plays an important role in development of obesity‐related kidney diseases. The purpose of current study was to investigate the role of Mas receptor in lipid‐induced kidney injuries. In human proximal tubular epithelial HK2 cells, saturated fatty acid palmitic acid (PA, 0.4mM) treatment induced increased LC3B and P62 protein expression and decreased LAMP1 expression, indicating an impaired autophagy flux and accumulation of autophagosome. This was associated with upregulated BIP and CHOP protein expression, two markers of endoplasmic reticulum stress (ER stress), and upregulated expression of cleaved caspase‐3, a marker of apoptosis. PA‐induced autophagosome accumulation, ER stress, and apoptosis was enhanced by Mas receptor agonists Ang (1‐7) or AVE0991, and suppressed by A779, a synthetic specific Mas inhibitor. PA‐induced impaired autophagy flux, increased ER stress and apoptosis were markedly attenuated by Mas receptor gene knockout in HK2 cells. Knockout Mas receptor also improved HK2 cell vitality and proliferation in response to PA treatment. Moreover, PA treatment caused elevated intracellular calcium levels, mitochondrial depolarization which were also markedly prevented by Mas knockout. Mas receptor gene knockout in HK2 cells was associated with markedly improved mitophagy after PA treatment. In mice with high‐fat diet for 12 weeks, Ang (1‐7) treatment caused enhanced autophagosome accumulation, ER stress, and apoptosis in the kidney cortex. In conclusion, Mas receptor mediated lipid‐induced impaired autophagy and ER stress in the kidney, likely contributing to tubular injuries seen in obesity‐related kidney diseases.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Novel role of dual oxidase 2 as a mediator of podocyte injury in the diabetic environment
Authors: Abraham Sachin M , Navarro Megan M , Wauquier Fabien M , Lee Doug‐Yoon , Gorin Yves , Ford Bridget M 
Published: June 2021

Glomerular injury is a prominent pathological feature of diabetic nephropathy (DN). In glomerular epithelial cells, or podocytes, hyperglycemia alters slit diaphragm proteins and causes foot process effacement, apoptosis and cell detachment. Oxidative stress has emerged as an important pathogenic mechanism in the development of glomerular injury in DN. However, the mechanisms by which these factors exert their action remain poorly understood.We provide evidence that the NADPH oxidase of the Nox family, Dual oxidase 2 (Duox2), is present in cultured glomerular cells, including podocytes. In mouse kidney cortex, immunostaining for Duox2 shows that a fraction of glomerular Duox2 colocalized with podocyte markers. Exposure of cultured podocytes to high concentrations of glucose (HG) elicited a rapid upregulation of Duox2 protein expression. Inhibition of Duox2 with specific siRNA prevented the HG‐induced increase in intracellular reactive oxygen species (ROS) generation and hydrogen peroxide (H2O2) production in cultured podocytes.In additional experiments, we established a functional link between Duox2‐derived ROS generation and podocyte injury in response to HG. Impairment of Duox2 function nearly abolished HG‐mediated DNA fragmentation, apoptosis and decrease in/reorganization of slit diaphragm protein expression in podocytes, indicating that Duox2 is required for the deleterious effects of glucose in podocytes.Our study demonstrates, for the first time, that Duox2 is responsible for increased ROS generation and subsequent alteration of podocyte function in response to HG. Our work serves as proof of concept to demonstrate the utility of targeting Duox2 as a future therapeutic intervention to reduce diabetes‐mediated glomerular lesions.Support or Funding InformationThis project was funded by the University of the Incarnate Word, Office of Research and Graduate Studies and the following grants: NRSA 5T32HL007446‐32, NIH 1RO1DK07999601A2, and NIH UL1 TR001120/IIMS Pilot ProjectThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Novel Concept for Origin and Treatment of Diabetic Nephropathy
Authors: Svensson Daniel , Zhang Liang , Panizza Elena , Nilsson Linnéa , Fontana Jacopo Maria , Moruzzi Noah , Scott Lena , Brismar Hjalmar , Aperia Anita 
Published: June 2021

ObjectivesDiabetic nephropathy (DN) is the most common cause of end‐stage renal failure and affects around 40% of all diabetic patients. This project aims to investigate the loss of proximal tubular cells (PTCs) in DN which are epithelial cells of the nephron leading away from the Bowman's capsule. Hyperglycemia induced damage to PTCs is attenuated by the Na/K‐ATPase ligand ouabain. Our second objective was thus to investigated the underlying mechanisms of ouabain in vitro and the function of Na/K‐ATPase as a signaling transducer.MethodsPTCs were isolated from mouse and rat kidney cortex and cultured for up to a week. COS‐7 kidney cells were used for some experiments. Protein expression and phosphorylation was studied by Western blotting and proteomics/phosphoproteomics. Gene ontology analysis was performed to find distinct cellular processes regulated by ouabain in the phopshoproteomic analysis. Seahorse was used for metabolic studies. Gene expression was analyzed by qPCR and apoptosis assessed by the TUNEL assay.Key resultsHigh glucose (HG, 15 mM) triggers apoptosis in PTC due to their expression of sodium dependent glucose transporter 2 (SGLT2), SGLT2 siRNA abolishes HG induced apoptosis. Apoptosis does not appear to coincide with a switch in glucose metabolism. Low concentrations of ouabain (10 nM) completely inhibits the apoptosis. Phosphoproteomic analysis revealed 2580 ouabain‐regulated phosphorylation sites, many of which were associated with cell adhesion and proliferation. Out of these, CaMK2γ were shown to be involved in the anti‐apoptotic effect of ouabain, siRNA silencing of CaMK2γ eliminates the protective effect of ouabain.ConclusionsLoss of tubular cells in DN might be driven by hyperglycemia due to the PTC expression of SGLT2. Low concentrations of ouabain protects from the detrimental hyperglycemic effects through an anti‐apoptotic mechanism involving CaMK2γ.Support or Funding InformationThe study was funded by the Swedish Research Council and Erling‐Persson Family Foundation. D.S. and N.M. is supported by a Novo Nordisk postdoctoral fellowship run in partnership with Karolinska Institutet.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Absence of Circadian Clock Gene Per1 Causes Increased Heart Rate and Hypertension in 129 Mixed Strain Mouse Model
Authors: Roig Emilio M , Masten Sarah , Miller Amber , Douma Lauren G , Lynch I Jeanette , Cheng Kit‐Yan , Wingo Charles S , Gumz Michelle L 
Published: June 2021

According to recently updated blood pressure guidelines, nearly half of Americans are affected by hypertension. A subset of these patients is salt sensitive, indicating that their blood pressure is more prone to acute changes in response to salt intake. Healthy individuals experience 24‐hour cycles in blood pressure, which is regulated by the molecular circadian clock. This clock is comprised of four core transcriptional factors, including period (PER) and BMAL. Our lab has previously demonstrated that male PER1 knockout mice (KO) on a C57B1/6 background become “non‐dippers” (failure to lower blood pressure during the inactive period) following a high salt (HS) diet plus an aldosterone analogue treatment (HS/DOCP, Solocinski et al. 2017). To test the role of PER1 in blood pressure regulation on a different background strain, we obtained global PER1 KO male mice on a 129/sv/S1S4 background. Similar to C57B1/6 KO, male KO on a 129/sv/S1S4 background lose their rhythm in mean arterial pressure (MAP) following the same HS/DOCP treatment. Based on this previous observation, we wanted to test the hypothesis that heart rate, systolic blood pressure, and diastolic blood pressure would also exhibit a loss of circadian rhythm compared to control mice (WT). Telemetry data from KO (n=7) and WT (n=4) following HS/DOCP treatment were collected. Analysis was performed using Cosinor software to fit data to a cosine wave, determining amplitude, mesor, and period. Male KO mice on a 129/sv/S1S4 background strain exhibited approximately twenty percent greater heart rate mesor compared to WT (KO: 488 ± 15; WT: 411 ± 10; P=0.005). The period and the amplitude for heart rate were similar between the groups (P=0.74, P=0.49). The systolic blood pressure mesor for KO was approximately 32 mmHg higher than WT (KO: 135 ± 6; WT: 103 ± 5; P=0.0054). No significant differences were found between period and amplitude for systolic blood pressure (P=0.65, P=0.58). Lastly, KO mice displayed 17 mmHg higher diastolic blood pressure mesor than WT (KO 113 ± 3; WT 96 ± 3; P=0.0025). No significant differences were found between period and amplitude for diastolic blood pressure (P=0.62, P=0.88). While individually the circadian rhythms of systolic and diastolic blood pressure are unaffected by PER1 KO in male 129/sv/S1S4 mice, MAP rhythms are dampened.Support or Funding InformationNIH/NIDDK 1R01DK109570 (MLG) and The Gatorade Trust through the UF Department of MedicineThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mapping chromatin accessibility in mouse nephron segments
Authors: Chen Lihe , Chou Chung‐Lin , Knepper Mark A 
Published: June 2021

Active DNA regulatory elements recruit transcription machinery to drive gene expression and generate nephron heterogeneity, which is crucial for renal physiology and pathophysiology. Such heterogeneity poses a significant challenge in the precise mapping of these DNA regulatory elements in each renal segment. Whole kidney chromatin accessibility analysis averages the signal from multiple cell types, thus it is necessary to carry out such analysis at the single‐tubule level.Here, we report single‐tubule ATAC‐seq, a method using hyperactive Tn5 transposase to simultaneously fragment and tag the regions of accessible chromatin with adapters for high‐throughput DNA sequencing. We adapted this method to the microdissected mouse proximal tubule S2 segment (PTS2), cortical thick ascending limb (cTAL), and cortical collecting duct (CCD). DNA libraries were sequenced to saturation and around 20M unique high‐quality reads were recovered for downstream analysis. Our data are consistent with the expected nucleosomal pattern and enrichment of reads in the transcription start site (UCSC, TSS, mm10), indicating the high quality and robust ATAC‐seq. Overall, we identified more than 95,000 narrow peaks for each segment (MACS2, ‐q 0.05 ‐‐nomodel). Coupled with single‐tubule RNA‐seq, for those transcripts uniquely expressed in these segments, our data revealed a high correlation of chromatin accessibility with gene expression. Initial analysis revealed unique chromatin openness in PTS2 including Slc22a7, Aqp1, Slc34a1, Kap; in cTAL including Hnf4a, Egf, Kcnj1, Umod, Slc12a1, Cldn16; and in CCD including Aqp2, Aqp3, Slc4a1, Fxyd4, and three ENaC subunits.Our results provide a comprehensive chromatin accessibility map for the nephron segments. The identification of these regulatory elements along the nephron will provide additional information beyond transcriptome and point to gene regulation in the kidney.Support or Funding InformationThe work was primarily funded by the Division of Intramural Research, National Heart, Lung, and Blood Institute (project ZIA‐HL001285 and ZIA‐HL006129, M.A.K.).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Renal Hemodynamic Function is Impaired in Female Mice with SLE
Authors: Dent Elena , Ryan Michael 
Published: June 2021

Systemic lupus erythematosus (SLE) is a chronic multi‐system autoimmune disease characterized by the presence of circulating autoantibodies, systemic and localized inflammation, prevalent hypertension, renal injury, and cardiovascular disease. Onset of the disease typically occurs in young women of child‐bearing age, a time when women are typically protected from cardiovascular risk factors like hypertension. Although kidney involvement is common to patients with SLE, and renal hemodynamic dysfunction is evident in patients with active renal disease, surprisingly little is known about early changes in renal hemodynamic function that may contribute to the pathogenesis of hypertension during autoimmune diseases. We hypothesize that the loss of immunological tolerance and subsequent production of autoantibodies in SLE leads to impaired renal hemodynamic function that precedes the development hypertension.Female NZBWF1 mice, an established experimental model of SLE, and female NZW (control) mice were instrumented with carotid artery and jugular vein catheters to determine mean arterial pressure (MAP) and glomerular filtration rate (GFR) respectively at ages 15, 20, 28, 31, and 34 weeks (n>3 control/age, n>4 SLE/age). MAP was measured in conscious, freely‐moving mice. GFR was measured by the clearance of fluorescein isothiocyanate‐inulin (FITC‐inulin) after achieving steady state through continuous infusion.From 15 weeks of age to 34 weeks of age, there is a progressive increase in the levels of circulating autoantibodies in female mice with SLE, whereas autoantibodies are unchanged in control mice (Figure 1). Compared with control mice, female mice with SLE have higher MAP at 15, 20, 28, 31, and 34 weeks of age, with an increase in pressure that occurs by 34 weeks of age (Figure 2). GFR remains moderately higher in SLE mice compared with control mice until 28 weeks of age at which time GFR sharply declines in the mice with SLE (Figure 3). GFR is unchanged in control mice across all ages.These data suggest that changes in renal hemodynamic function occur in female SLE mice prior to changes in MAP suggesting an important mechanistic role for autoimmunity to directly impair renal hemodynamic function and promote the development of hypertension.Support or Funding InformationVA Merit BX002604, American Heart Association Predoctoral 19PRE34380830, NIH P20GM104357, NIH 5U54GM115428, NIH 5P01HL051971This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.