bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncoupling of Sodium and Potassium Excretion in Kidney‐Specific BMAL1 Knockout Mice following Potassium Depletion
Authors: Crislip Gene Ryan , Douma Lauren G , Masten Sarah H , Cheng Kit‐Yan , Lynch I. Jeanette , Barral Dominique , Glasford Krystal , Esser Karyn A , Wingo Charles S , Gumz Michelle L 
Published: June 2021

Blood pressure regulation is influenced by circadian clock factors. BMAL1 is a core mammalian circadian transcription factor responsible for the tissue‐specific regulation of thousands of genes. We have generated a kidney‐specific knockout of BMAL1 that exhibits lower blood pressure compared to control mice (CNTL). Additionally, qPCR data demonstrated basal differences in expression of potassium handling genes. The goal of this study was to determine if solute excretion in response to a potassium depleted diet was different in kidney‐specific BMAL1 knockout mice (KO) compared to CNTL. Our mouse model was generated using floxed exon 8 BMAL1 mice crossed with kidney‐specific cadherin Cre+ mice to generate KO. Floxed Cre− littermates were used as CNTL. Metabolic cages were used for urine collection. Urinalysis was performed via flame photometry. Basal urinary sodium and potassium excretion was similar between CNTL and KO (Na: 0.29±0.02 vs. 0.29±0.01 mmol; P=0.6; K: 0.65±0.05 vs. 0.64±0.02 mmol; P=0.2; N=5–6). After baseline measurements, mice were administered a potassium depleted diet for 5 days. There was a transient decrease in food intake in both genotypes (P<0.0001), however, body weight remained unchanged throughout treatment (P=1). Both body weight and food intake were comparable between CNTL and KO. Potassium excretion decreased within 24 hours of the start of treatment in both genotypes and remained low for all 5 days (CNTL: 0.012±0.002; KO: 0.015±0.004 mmol; PINTERACTION=0.3). Initially, sodium excretion decreased following potassium depletion in both groups which was matched with transient sodium retention. Interestingly, sodium excretion remained lower than baseline throughout treatment in CNTL whereas KO increased back to baseline levels by day 5 of treatment (0.19±0.01 vs. 0.26±0.01 mmol; PINTERACTION=0.0001). As expected, plasma aldosterone decreased following potassium depletion, however, levels were comparable between the groups (P=0.5). BMAL1 in the distal nephron and collecting duct play a role in regulating sodium handling in male mice in response to dietary potassium depletion. KO are able to uncouple sodium and potassium excretion during a potassium depleted diet. The mechanism responsible for this may shed light on the lower blood pressure phenotype that KO exhibit.Support or Funding Information5T32HL083810‐10 NIH/NIDDK 1R01DK109570 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.
Acidic Environment Facilitates Mitochondrial Fragmentation Induced by APOL1 Renal‐Risk‐Variants in Kidney Cells
Authors: Li DengFeng , Snipes James A. , Divers Jasmin , Freedman Barry I. , Ma Lijun , Petrovic Snezana 
Published: June 2021

African Americans frequently carry G1 and G2 renal‐risk variants of the apolipoprotein L1 (APOL1) gene. Two copies of G1 and/or G2 confer 5–29 fold higher risk of chronic kidney disease (CKD); however, only 20% of those carrying risk‐genotype develop CKD. This indicates that an additional stressor may facilitate development of CKD in those carrying G1/G2 risk variants. Considering that a) G1/G2 variants elicit mitochondrial dysfunction in renal cells, b) APOL1 function is pH sensitive and c) renal interstitial pH is <7, we hypothesized that acidic interstitial environment in the kidney may amplify mitochondrial dysfunction induced by G1/G2 variants. To test the hypothesis, we incubated human embryonic kidney (HEK293) cells expressing APOL1 in pH=6.8 or 7.4; we estimated early mitochondrial dysfunction by measuring mitochondrial network morphology with confocal microscopy (Fig.1). HEK293 cells stably expressing APOL1 G0, G1, G2 or empty vector (EV) under doxycycline (Dox) control were exposed to Dox for 4, 6 or 8hr, while cultured in media pH=6.8 or pH=7.4. Confocal images were acquired at 1000 magnification in live cells kept in an environmentally‐controlled chamber at each time point; FIJI software was used to quantify relative mitochondrial length (ratio of “rods” vs. “network‐branches”). We also ascertained that a) APOL1 expression was comparable regardless of pH or APOL1 genotype for up to 8hr post Dox‐induction using real‐time PCR and b) cell viability was comparable under all conditions using lactate‐dehydrogenase‐based cytotoxicity assay. Without Dox, relative mitochondrial length was similar regardless of APOL1 genotype or pH. However, after 6hr of Dox‐induction in media pH=6.8, G2‐expressing cells had shorter mitochondrial length (6.54±0.40) vs. EV (7.65±0.72, p=0.02) or G0 cells (7.46±0.31, p=0.003), indicating early mitochondrial fragmentation. After 8hr of doxycycline‐induction in media pH=6.8, mitochondrial length in G1 (6.21±0.26) and G2 cells (6.46±0.34) was lower than EV (7.13±0.32, p=0.002 and p=0.008, respectively) and G0 cells (7.22±0.45, p=0.003 and p=0.01, respectively; Fig. 2). At media pH 7.4, mitochondrial length was comparable up to 8hr of Dox‐induction, regardless of APOL1 genotype. We concluded that acidic pH may facilitate early mitochondrial dysfunction induced by G1/G2 APOL1 risk‐variants in renal cells. We propose that an acidic interstitial pH may facilitate adverse effects of APOL1 renal‐risk variants in the kidney, but not other organs expressing APOL1.Support or Funding InformationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Administration of a selective prostaglandin E2 receptor agonist attenuates renal fibrosis in vitro and in vivo
Authors: Jensen Michael Schou , Mutsaers Henricus A.M. , Tingskov Stine Julie , Christensen Michael , Madsen Mia Gebauer , Olinga Peter , Kwon Tae‐Hwan , Norregaard Rikke 
Published: June 2021

Renal fibrosis plays a pivotal role in the development and progression of chronic kidney disease (CKD), which affects 10% of the adult population. Previously, it has been demonstrated that the cyclooxygenase‐2 (COX‐2)/prostaglandin (PG) system influences the progression of renal injury. PGE2 interacts with four different G‐protein‐coupled PGE2 EP receptors, known as EP1–EP4, and plays a role in several biological functions. Previous studies show that the EP2 receptor is involved in progression of lung fibrosis. In this study, we investigated the effect of an EP2 agonist (butaprost) on renal fibrogenesis on a cellular, renal tissue and organismal level using well‐established in vivo and in vitro models as well as a recently developed human model of renal fibrosis. This model is ideal to study multicellular pathological processes, e.g. fibrosis, directly in human tissue since cellular diversity and organ architecture is maintained in the slices. Butaprost (50 μM) reduced TGF‐β‐induced fibronectin (FN) expression, Smad2/3 phosphorylation and epithelial‐mesenchymal transition in MDCK cells. In addition, treatment with 4 mg/kg butaprost attenuated the development of fibrosis in mice that underwent unilateral ureteral obstruction (UUO) surgery, as illustrated by a significant reduction in the gene and protein expression of α‐smooth muscle actin, FN and collagen 1A1. More importantly, a similar anti‐fibrotic effect of butaprost was observed in human precision‐cut kidney slices exposed to TGF‐β. The mechanism of action of butaprost appeared to be a direct effect on TGF‐β/Smad signaling, which was independent of the cAMP/PKA pathway. In conclusion, this study demonstrates that stimulation of the EP2 receptor effectively mitigates renal fibrogenesis in various fibrosis models. These findings warrant further research into the clinical application of butaprost, or other EP2 agonists, for the inhibition of renal fibrosis.Support or Funding Information Sources of support: This work was kindly supported by Lundbeckfonden, grant number R231‐2016‐2344 as well as the Danish Council for Independent Research, grant number 6110‐00231B, Aarhus University Research Foundation, grant number AUFF‐E‐2015‐FLS‐8‐69 and Hildur and Dagny Jacobsens Foundation grant number 1295716‐1.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reno‐protective Effect of Central Leptin Receptor Blockade in Rat Model of Menopause
Authors: Van Erdewyk Jonathan , Khan Bilal , Babich Victor , Barnes Maria , Di Sole Francesca 
Published: June 2021

Women in menopause have substantial variations in hormonal balance. The weight gain in the form of adipose tissue in these women has been associated to an increase in leptin level; an adipocyte‐derived hormone that acts primarily on the central nervous system. The increase in central leptin has been related with the development of hypertension via an increase in renal sympathetic nerve activity (RSNA) and activation of RSNA has been demonstrated to play a role in the progression of kidney dysfunction. Therefore, we hypothesize that activation of RSNA due to elevated leptin induces hypertension via an action on kidney function. Utilizing a menopausal rat model, we studied the mechanisms mediated by central leptin receptor activation to alter kidney function. We measured the glomerular filtration rate (GFR) by creatinine clearance and protein level of the neutrophil gelatinase‐associated lipocalin (NGAL), an early biomarker of kidney injury, by immunohistochemistry. An increase in creatinine clearance (from 1.3 ml/min to 2.3 ml/min) and protein levels of NGAL (over 90% increase in both glomeruli and tubules) was measured in ovariectomized adult female rats when compared with their sham‐operated controls. Treatment with leptin reception antagonist (LAN‐6, 3μg/day), delivered for four weeks into the lateral ventricle by an osmotic pump, significantly attenuated these effects. Furthermore, we determined that intra‐abdominal and perirenal fat accumulation were both markedly higher in the same menopausal rat models. Perirenal fat accumulation has been associated with lipid accumulation in renal tissues and excess of intrarenal lipid is increasingly recognized to contribute to kidney injury through lipotoxicity. We found a significant accumulation of renal lipid, tested using oil red O staining, in the renal tubules of the ovariectomized animals when compared with their controls. The lipid accumulation was partially reversed by the leptin receptor antagonist treatment. In summary, the increase in GFR associated with kidney injury suggests the development of kidney disease in this rat model of menopause that is in part reversed by blocking central leptin receptors; infiltration of lipid in the renal tissue is proposed as a possible mechanism of kidney injury. These findings have the potential to translate into future therapeutic strategies for treating kidney injury in menopausal mediated‐hypertension.Support or Funding InformationIowa Osteopathic Education and Research FundsThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Salt‐Responsive Metabolite, beta‐Hydroxybutyrate, Attenuates Hypertension
Authors: Chakraborty Saroj , Galla Sarah , Cheng Xi , Yeo Ji‐Youn , Mell Blair , Singh Vishal , Yeoh BengSan , Saha Piu , Mathew Anna V. , Vijay‐Kumar Matam , Joe Bina 
Published: June 2021

Dietary salt reduction and exercise are lifestyle modifications for salt‐sensitive hypertensives. While exercise has prominent metabolic effects, salt has an adverse effect on metabolic syndrome, of which hypertension is a hallmark. We hypothesized that dietary salt impacts metabolism in a salt‐sensitive model of hypertension. An untargeted metabolomics approach demonstrates lower circulating levels of the ketone body, beta‐hydroxybutyrate (βOHB), in high salt‐fed hypertensive rats. Despite the high salt intake, specific rescue of βOHB levels by nutritional supplementation of its precursor, 1,3‐butanediol, attenuates hypertension and protects kidney function. This beneficial effect of βOHB was likely independent of gut‐microbiotal and Th17‐mediated effects of salt and instead facilitated by βOHB inhibiting the renal Nlrp3 inflammasome. The juxtaposed effects of dietary salt and exercise on salt‐sensitive hypertension, which decrease and increase βOHB respectively, indicate that nutritional supplementation of a precursor of βOHB provides a similar benefit to salt‐sensitive hypertension as exercise.Support or Funding InformationFunding from this work to BJ from the NHLBI (NIH) (HL143082) is gratefully acknowledged.Declaration of interests: Bina Joe and Saroj Chakraborty have an interest in U.S. Patent Application Serial No.: 62/665,690 filed on May 2, 2018 in this paper regarding nutritional intervention for salt‐sensitive hypertension for 1,3‐butanediol.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
High Sodium Diet in 11β Hydroxysteroid Dehydrogenase Type 2 CNS Knockout Mice Induces a Proinflammatory Phenotype of Perivascular Adipose Tissue and Alterations in Arterial Reactivity
Authors: Grenier Celine , Ralph Ailsa , Livingstone Dawn EW , Holmes Megan C , Bailey Matthew A 
Published: June 2021

RationaleWe previously generated CNS‐specific knockout of HSD2 (“brain” knockout; BKO), showing that the mice have inappropriate salt‐appetite and hypertension under a high sodium diet (Evans, Ivy et al. 2016) . Multiple peripheral components may contribute to this salt‐sensitivity and here we have focussed on the role of resistance arteries, which are surrounded by perivascular adipose tissue (PVAT), able to secrete vasoactive molecules (pro‐ or anticontractile). It is well known that PVAT interacts with arteries to regulate their function. Studies also show that high‐sodium diet stimulates adipocity and alters adipocyte function. Our aim is to study the impact of high sodium intake on PVAT gene expression and on arterial reactivity in BKO knockout mice.MethodsBKO mice were generated by crossing HSD2flx/flx with Nestin‐Cre mice; HSD2flx/flx littermates were used as wild‐type controls (WT). Mice were fed with high sodium diet (HSD; 3% Na) or normal sodium diet (NSD; 0.3% Na) for one week before being culled. The PVAT and the mesenteric arteries were dissected. The arterial reactivity to phenylephrine (Phe), acetyl choline (Ach) and sodium nitroprusside (SNP) was studied by wire myography. In PVAT from mesenteric arteries, the expression of a panel of pro or anti inflammatory markers was measured by qRT‐PCR.ResultsOn normal sodium diet, There was no difference between genotypes in the PVAT expression of a panel of genes reporting inflammation (adipoq, lep, cybb, ptgs2, agtr1a, serpin, pparg, il‐6, ccl2, adgre1, vcam1, atp6ap2, nampt). High sodium diet demonstrated a significant (all P<0.05) overexpression of the proinflammatory genes il‐6, ccl2, cybb and ptgs2 on BKO fed with HSD compared to WT; other genes were not different. In PVAT‐free mesenteric arteries, hsd11b2 gene expression was not different between WT and BKO mesenteric arteries and on normal sodium diet, arterial reactivity to Phe, Ach and SNP was not different between genotypes. In contrast, 7 days of high sodium intake revealed there were differences in arterial function between genotypes: there was a significant increase in sensitivity to Phe in the WT and a decrease of the maximum effect of SNP in the BKO mice.ConclusionThe high salt diet on BKO mice led to an overexpression in pro‐inflammatory gene in the PVAT surrounding mesenteric arteries and affected intrinsic arterial reactivity. The interaction between these two phenomena remains to be elucidated but it may contribute explanation to the increase of blood pressure of salt sensitive BKO mice.Support or Funding InformationThis work was funded by The British Heart Foundation (PG/16/98/32568)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Activation of G Protein‐Coupled Estrogen Receptor 1, with a GPER Agonist, Reduces Blood Pressure in Female Growth‐Restricted Rats in Later Life
Authors: Davis Gwendolyn K. , Bamrick Daniel R. , Newsome Ashley D. , Coats Laura E. , Alexander Barbara T. 
Published: June 2021

The prevalence of hypertension (HTN) is two‐fold higher in low birth weight (LBW) women at age 60 relative to their normal birth weight (NBW) counterparts. Yet, the mechanisms that contribute to greater cardiovascular risk in LBW women are not known. In our model of intrauterine growth restriction (IUGR), induced by placental insufficiency in the pregnant rat, female IUGR offspring have an elevated blood pressure (BP) at 12 months of age that is associated with early reproductive senescence. Although estrogen levels do not differ between control and IUGR groups, there is a significant increase in testosterone levels in female IUGR that is not seen in female control. Elevated testosterone levels, due to an imbalance in the hormonal milieu, is suggested to contribute to the development of hypertension in women in later life. We previously reported that chronic administration of estradiol is able to abolish the increase in blood pressure in the female IUGR rat at 12 months of age. However, this was not accomplished through alterations in expression of the nuclear estrogen receptor alpha (ER‐alpha). In the current study, we tested the hypothesis that activation of G protein‐coupled estrogen receptor 1 (GPER) would reduce blood pressure in the female IUGR rat. The selective GPER agonist, G1 (400 g/kg/day), or vehicle was administered via osmotic pumps for 2 weeks beginning at 14 months of age. BP was measured in conscious, chronically catheterized rats following treatment (2way ANOVA; Tukey's multiple comparison). As shown previously, BP was significantly elevated in vehicle‐treated IUGR relative to vehicle‐treated control (138.3± 4.01 vs. 124.3 ± 0.70mmHG, respectively). BP was significantly decreased in G1‐treated IUGR relative to vehicle‐treated IUGR (125.14±4.03 vs. 138.3 ± 4.01mmHG, respectively), whereas BP was not significantly altered in G1‐treated control relative to vehicle‐treated control (124.5 ± 0.66 vs. 124.3 ± 0.70mmHG, respectively). Uterine weight did not differ between groups. Therefore, this data suggests that activation of GPER was able to abolish the increase in blood pressure in the female IUGR rat in later life. This study suggests that GPER may serve as a therapeutic target for ameliorating increases in blood pressure seen in LBW women in later life.Support or Funding InformationNIH: R56HL143459, P20GM121334, P20GM104357, P01‐HL51971, T32HL105324, F30DK112718. AHA: GRNT19900004, PRE34060010.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
AT1a stimulation of tonicity‐responsive enhancer binding protein (TonEBP/NFAT5) translation through Annexin‐A2 may represent allostatic anticipation of increased tonicity
Authors: Hultström Michael , Paliege Alexander , Jönsson Sofia , Agic Mediha Becirovic , Melville Jacqueline , Skogstrand Trude , Fähling Michael 
Published: June 2021

Allostasis is idea that the body may anticipate homeostatic challenges and regulate cell and organ function in preparation. Angiotensin II (ANGII) is important for regulating sodium balance and as such increases tonicity in the renal medulla. The present study identifies a novel regulatory pathway whereby ANGII increases the translation of tonicity‐responsive enhancer binding protein (TonEBP/NFAT5) by activating nucleic acid binding of Annexin‐A2, which has several binding sites on NFAT5 mRNA and increases its translation. The activation of Annexin‐A2 was shown using heparin affinity chromatography and mass spectrometry in four‐week two‐kidney, one‐clip hypertension, and verified in two‐week ANGII infusion in rats. The addition of the AT1‐receptor blocker Losartan reduced the activation. Renal gene expression was studied using micro arrays, and identified NFAT5 targets as enriched. Western blot showed that NFAT5 protein was increased, while mRNA was not significantly regulated consistent with posttranscriptional regulation by Annexin‐A2. In conclusion, ANGII/AT1/Annexin‐A2‐mediated increase of the normally tonicity‐regulated NFAT5 in the kidney may be a way to ensure a more robust response to ANGII‐induced tonicity increase, and thus better protect homeostasis.Support or Funding InformationLars Hierta Foundation, Magnus Bergvall Foundation, Swedish Society for Medical Research.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Microbiota and Xenobiotics Reveal Links between Myopathy, Inflammaging and Glycolytic Metabolism
Authors: Schertzer Jonathan 
Published: June 2021

Environmental cues influence the risk and severity of myopathy and sarcopenia. Increased inflammation during ageing (i.e. inflammaging) has been proposed as a contributor sarcopenia. The source of age‐related inflammation is ill‐defined. Xenobiotics, including therapeutic drugs, can also promote inflammation that contributes to myopathy. However, the participatory immune components that link either of these stressors to functional decline in skeletal muscle are unknown. The intestinal microbiota has emerged as an environmental factor that can alter xenobiotic metabolism, inflammation and host metabolism. We sought to define aspects of the microbiota and specific innate immune components that connect triggers of inflammation during ageing or xenobiotic exposure.We used statins as a xenobiotic given well documented statin myopathy. Despite the widespread anti‐inflammatory effects, statins actually increase a very specific immune response that is propagated by an inflammasome that acts as a metabolic danger sensor. Statins activate the NOD‐like receptor family, pryin domain containing 3 (NLRP3) inflammasome. In order to implicate the microbiota, we used aged germ free mice and mice lacking bacterial cell wall sensors to test how the entire microbiota alters sarcopenia.We hypothesized that NLRP3‐null mice would be protected from statin‐induced myopathy and sarcopenia compared to wild type (WT) mice. We hypothesized that germ free mice (devoid of any bacteria) and Nod1‐null would be partially protected from age‐related inflammation and sarcopenia.We found that NLRP3‐null mice had an attenuation of statin myopathy and sarcopenic indicators compared to WT mice. A common mechanism between sarcopenia and statin myopathy was lower glycolysis in muscle cells. Further, specific bacterial ligands such as lipopolysaccharide exposure magnified statin myopathy. However, we found that germ free mice had worse indicators of sarcopenia compared to conventional mice. We found that Nod1‐null mice had worse indicators of sarcopenia compared to WT mice.Our results show that xenobiotics and aging alter glycolytic metabolism, which is a common mechanism linking inflammasome responses to myopathy from various stressors. Specific bacterial components play a role in augmenting statin‐induced myopathy via the NLRP3 inflammasome. However, the totality of the bacterial community and bacterial cell wall sensing actually protects against sarcopenia.Support or Funding InformationFunded by Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canadian Institutes of Health Research (CIHR).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.