bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calcium‐dependent dual oxidase 2 is a novel source of reactive oxygen species implicated in glomerular mesangial cell fibrotic response to angiotensin II
Authors: Pedroza Aleksis Ramirez , Martinez Alexandra , Wauquier Fabien , Lee Doug‐Yoon , Gorin Yves , Ford Bridget M 
Published: June 2021

The vasoactive peptide angiotensin II (Ang II) contributes to the initiation and the progression of glomerular fibrosis via activation of glomerular mesangial cells (MCs) and subsequent extracellular matrix expansion. We have previously shown that oxidative stress is critical for MC fibrotic response to Ang II. Here, we demonstrate that Dual oxidase 2 (Duox2), a member of the Nox/Duox family of NADPH oxidases, is present in MCs and that its protein expression is upregulated by Ang II.Small interfering RNA (siRNA)‐mediated downregulation of Duox2 significantly reduces Ang II‐induced increase in reactive oxygen (ROS) generation and prevents the stimulatory effect of Ang II on MC fibrotic injury (as assessed by measuring a‐smooth muscle actin and fibronectin expression).Duox2 activation is Ca2+‐dependent. Next, we investigated the role of Ca2+ in Ang II‐mediated Duox2 activation and the resulting fibrotic response. We show that the extracellular Ca2+ chelator BAPTA prevented Ang II‐induced ROS generation and the stimulation of MC fibrotic injury by Ang II. Moreover, treatment of MCs with ionomycin resulted in increased ROS production and enhanced MC fibrotic injury. These effects were abrogated by siRNA targeting Duox2. These data indicate that Ang II‐stimulated Duox2 activation and ROS generation subsequently lead to MC fibrotic injury.In summary, we have identified a novel role for Duox2 as a major source of ROS in response to Ang II and established the significance of Duox2 in Ang II‐mediated MC activation and fibrotic injury. Therapeutic targeting of this pathway may prevent or reverse pathophysiologic manifestations of renal fibrotic diseasesSupport 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.
Female mice are protected against the renal pro‐inflammatory effects of a high‐salt diet during diabetes
Authors: Giani Jorge F , Hernandez Adela F , Bernstein Ellen A , Veiras Luciana C , Khan Zakir , Cao DuoYao , Peng Zhenzi , Bernstein Kenneth E 
Published: June 2021

IntroductionHigh‐salt diet and hypertension are major contributors to diabetic nephropathy and predispose to end‐stage renal disease. In addition, studies in both humans and animal models of diabetes demonstrated that males have higher incidence of diabetic kidney disease compared to females.ObjectiveWe aim to determine the contribution of a high salt diet to the development of renal inflammation associated with diabetes in female versus male diabetic mice.MethodsFour‐month‐old female and male db/db mice (a model of type 2 diabetes) and non‐diabetic controls were exposed to either a high (4% NaCl w/w) or control (0.4% NaCl w/w) diet for 3 weeks (n=4). Systolic blood pressure (SBP) was measured by the tail‐cuff method. At the end of the protocol, mice were euthanized, and kidneys were preserved to assess renal inflammation.ResultsA high salt diet did not modify the blood pressure in any experimental group. At the beginning of the high salt diet, SBP was 99 ± 8 mmHg in diabetic females and 100 ± 3 mmHg in diabetic males. After 3 weeks of high salt, SBP was 101 ± 4 mmHg in diabetic females and 106 ± 2 mmHg in diabetic males (P=NS). However, male diabetic mice exposed to high salt displayed higher abundance of renal TNFα (1.8‐fold increase, P<0.001), IL‐6 (1.9 fold‐increase, P<0.01) and IL‐1β (2.1‐fold increase, P<0.05) compared to equally treated diabetic females. Further, male diabetic mice displayed higher expression of renal NLRP3 inflammasome components such as Pro‐caspase‐1 (2.6‐fold increase, P<0.01), caspase‐1 (2.2‐fold increase, P<0.05) and the adaptor protein ASC (2.3‐fold increase, P<0.05) compared to female diabetic mice. Finally, the anti‐inflammatory cytokine IL‐10 was decreased in diabetic males exposed to a high salt diet compared to diabetic males receiving a control diet (from 563 ± 23 to 411 ± 21 pg/mg kidney protein, P<0.05). In female diabetic mice, IL‐10 remained unchanged. Both female and male non‐diabetic mice displayed no changes in response to a 3‐week high salt diet.ConclusionEven in the absence of salt‐sensitive hypertension, male diabetic mice are more susceptible to the renal pro‐inflammatory effects of a high‐salt diet compared to female diabetic mice.Support or Funding InformationThis study was supported by NIH R01HL142672, AHA 16SDG30130015, and P30 DK063491 (JFG); NIH R01HL110353 and AHA 17GRNT32580000 (KEB).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Controlling Glucose Handling via Renal Olfr1393 Offers Protection in a Type I Diabetic Mouse Model
Authors: Schiazza Alexis R , Shepard Blythe D 
Published: June 2021

Olfactory receptor 1393 (Olfr1393) is a G‐protein coupled receptor that has vital functionality outside of its native environment in the nose. In recent reports, we have discovered that renal Olfr1393 localizes to the apical membrane of the renal proximal tubule (PT) where it aids in glucose reabsorption in both health and disease (through a diet‐induced obesity model of type II diabetes) via the sodium‐glucose co‐transporters. To identify additional roles for Olfr1393, we induced type I diabetes (T1D) in whole animal Olfr1393 wildtype (WT) and knockout (KO) male and female mice. Low dose Streptozotocin (STZ: 55 mg / kg BW) injections were administered for 5 consecutive days to deplete pancreatic β‐cells and induce insulin deficiency. Preliminary studies indicate that by 2 weeks post‐STZ, WT male mice develop hyperglycemia (2hr fasting blood glucose (mg/dl): WT diabetics – 383.3 ± 30.1 vs WT vehicle controls – 156.5 ± 24.5) and impaired glucose tolerance (area under curve in thousands (AUC) WT diabetics – 37.8 ± 5.8 vs WT vehicle – 19.8 ± 1.0). In keeping with its function in PT glucose reabsorption, compared to the diabetic WTs, KO mice have lower 2h fasting blood glucose values (Diabetic WTs: 383.3 ± 30.1 vs KOs: 272.7 ± 27.7) and improved glucose tolerance (AUC: Diabetic WTs: 37.8 ± 5.8 vs KOs – 30.1 ± 2.3). No significant differences were detected in insulin sensitivity between diabetic WT and KO mice. One hallmark of T1D is the development of glomerular hyperfiltration; notably, neither diabetic WT nor KO mice present with diabetic hyperfiltration by 5 weeks post‐STZ when measured by transcutaneous elimination kinetics of FITC‐sinistrin. Efforts are currently underway to determine the glomerular damage induced by our T1D model. Collectively, this study indicates that Olfr1393‐mediated control of renal glucose handling is important for the progression of T1D, likely through the regulation of the Sglts.Support or Funding InformationNIDDKThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Store‐Operated Calcium Entry in Mesangial Cells and Glomerular Inflammatory Responses
Authors: Chaudhari Sarika , Shotorbani Parisa Yazdizadeh , Wang Yanxia , Ma Rong 
Published: June 2021

Emerging evidence indicates that immunological and inflammatory mechanisms play a significant role in the development of diabetic nephropathy (DN). The early features of DN include accumulation of extracellular matrix (ECM) in the glomerular mesangium. Inflammatory cell infiltration mediated by locally produced cytokines/chemokines contributes to the histological impairment in DN. Glomerular mesangial cell (MC) is a major cell type in glomerulus to produce cytokines/chemokines in response to diabetes and a major contributor to mesangial expansion in DN. We have previously demonstrated that the Orai‐1 mediated store‐operated calcium entry (SOCE) suppressed ECM protein production by MCs. The aim of this study was to determine whether SOCE in MCs regulated cytokine/chemokine production by MCs and macrophage infiltration into glomerulus.MethodsOrai‐1 channel protein in MCs was knocked down using the targeted nanoparticle‐siRNA delivery system in wild‐type C57BL6 mice at the age of 16 weeks. Immunohistochemistry was performed on the paraffin‐embedded kidney sections to examine macrophages infiltration in glomeruli using F4/80 as a marker. In cultured human MCs, the levels of various inflammatory cytokines (MCP‐1, TNF‐α, IL‐6) were examined using ELISA in the presence of normal glucose (5 mM D‐glucose + 20 mM L‐glucose) or high glucose (25 mM D‐glucose) with/without an activator (thapsigargin at 1 μM) of SOCE.ResultsIn vivo knockdown of Orai1 in MCs induced infiltration of F4/80 stained macrophages into the glomeruli in the mice treated with nanoparticle/Orai1 siRNA for 5 days compared to the control mice. In cultured human MCs, 24‐hour treatment with high glucose significantly increased the expression levels of MCP‐1 and TNF‐α. The high glucose responses were significantly blunted by thapsigargin. However, high glucose treatment for 24 hours significantly decreased and activation of SOCE by thapsigargin significantly increased IL‐6 expression level in MCs.ConclusionOrai‐1 mediated SOCE in MCs inhibits the glomerular macrophage infiltration in mice and has differential effects on the expression of different cytokine/chemokines in MCs.Support or Funding InformationNIH/NIDDK (1RO1 DK115424); AHA Southwest Affiliate (16GRNT27780043); Harry S. Moss Heart Trust Award.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of Sex and GPER in Renal Damage Induced by Ang II Hypertension
Authors: Aguerre Ines M. , Gentry Kaylee M. , Lindsey Sarah H. 
Published: June 2021

The protective cardiovascular effects of estrogen are mediated by both the classic steroid receptors (ERα/β) and the novel G protein‐coupled estrogen receptor (GPER). We previously showed that genetic deletion of GPER does not alter the pressor response to Ang II but exacerbates pulse pressure and resistance artery contractility. The objective of the current study was to assess whether G protein‐coupled estrogen receptor (GPER) deletion is associated with evidence of renal damage in mice with intact ERα/β signaling. Male (M) and female (F) wildtype (wt) and GPER knockout (ko) mice were infused with Ang II (700 ng/kg/min) for two weeks. Kidneys were weighed, formalin‐fixed, and paraffin‐embedded. Renal damage was assessed in 4 mm sections mounted onto slides. Renal vascular fibrosis was quantified as percent of pixels with positive Masson's Trichrome staining, and renal infiltration was scored on a scale of 1–5 in sections stained with hematoxylin & eosin. Statistical analysis was completed using two‐way ANOVA. Kidney weights in Ang II‐infused mice were significantly higher in males (P< 0.0001) but were not impacted by GPER deletion (P=0.16; Fwt: 6.3 ± 0.2, Fko 6.1 ± 0.1, Mwt 7.6 ± 0.3, Mko 7.2 ± 0.2 mg/g body weight, n=7–9/group). Renal vascular fibrosis was not significantly affected by sex (P=0.29) or genotype (P=0.93). Interstitial infiltration was observed in the medulla, but there was no effect of sex (P=0.24) or genotype (P=0.58). Our findings indicate that neither sex nor GPER deletion significantly impacted renal damage in response to two week Ang II infusion. Future studies will determine whether sex and GPER play a role in renal damage when Ang II hypertension is induced for longer than two weeks.Support or Funding InformationFunding was provided by NIH HL133619 to SHL. The STRIDE Fellowship is supported by the American Physiological Society and NIH HL115473.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Kynurenine Induces Renal Fibrosis which May Contribute to Bone Loss in Aging
Authors: Irsik Debra L , Xu Jianrui , Bollag Wendy B , Isales Carlos M. 
Published: June 2021

Aging results in both bone loss and renal dysfunction, and the two conditions are interrelated. Low‐protein diets are recommended to increase longevity in the elderly but may occur at the expense of bone density. Tryptophan, an essential amino acid, is at greatest risk of depletion. Aging is marked by low tryptophan levels and higher levels of its oxidized metabolite, kynurenine (KYN). Feeding a low‐protein diet supplemented with KYN results in bone loss in younger mice; however, the renal effects of KYN have not been evaluated in this model. We hypothesized that KYN feeding induces bone loss and renal dysfunction through the fibroblast growth factor‐23 (FGF23)/α‐Klotho pathway involved in renal handling of calcium and phosphate and production of 1,25‐dihydroxyvitamin D. Male C57BL/6 mice (13 months old) were fed either a low‐protein (LP, 8%) or normal‐protein (NP, 18%) diet with or without KYN for 8 weeks. LP induced significant diuresis (2.16 ± 0.08 mL/day) that was attenuated with KYN (1.28 ± 0.10 mL/day). Glomerular filtration rate (GFR) was not different among the groups. Albuminuria was increased with age in the NP‐ or NP+KYN‐fed mice but not in the LP or LP+KYN groups. Tubulo‐interstitial fibrosis was present in LP‐ and LP+KYN‐fed mice and was not different from 24‐month‐old mice. Serum levels of FGF23 were elevated in LP‐fed mice but did not reach significance. Kidney protein levels of α‐Klotho declined with age. Our preliminary data suggest that KYN feeding may induce renal fibrosis that may contribute to bone loss, and FGF23/α‐Klotho may be involved. Further studies are needed to define a role for KYN in renal aging.Support or Funding InformationPO1 AG036675 and AG036675S1This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
125Iodide as a Surrogate for 36Chloride in Tracing Transepithelial Intestinal Chloride Transport
Authors: Stephens Christine Elizabeth , Whittamore Jonathan Mark , Hatch Marguerite 
Published: June 2021

Chloride (Cl−) transport by the large intestine is critically important, driving epithelial fluid secretion and absorption. Dysregulation of Cl− transport by the intestine results in diarrhea‐associated pathologies. Measurement of epithelial Cl− transport has long been achieved using the radioisotope 36Cl−. However, the price of 36Cl has sky‐rocketed, now costing over $100 per μCi compared to just $1.50 per μCi 15 years ago, making it prohibitively expensive and a barrier to future research. 125Iodide (125I−) has been used as an alternative to 36Cl− in some transport assays, including Cl− efflux and influx by cultured cells, but has never before been validated in parallel with 36Cl as an alternative for tracing transepithelial Cl− transport. The goal of this study was to examine whether 125I− can serve as a reliable surrogate for measuring Cl− transport by the intestinal epithelium. Under symmetrical short‐circuited conditions in the Ussing chamber, we simultaneously measured 36Cl− and 125I− fluxes across the cecum and distal colon from mice lacking the main Cl−/HCO3− exchanger, DRA (Slc26a3), relative to wild‐type controls. In addition, we used a cocktail of forskolin and 3‐isobutyl‐1‐methylxanthine (IBMX) to stimulate cAMP production and net Cl− secretion by these tissues. We found the unidirectional fluxes of 125I− correlated well with 36Cl− in all circumstances, even in the absence of DRA, with a significant R2 value of 0.86 across all fluxes, or higher (up to 0.93) when data was separated by genotype and intestinal segment. Unexpectedly, cAMP induced net Cl− secretion predominantly through a reduction in the absorptive, mucosal‐to‐serosal, Cl− flux rather than stimulating the secretory serosal‐to‐mucosal Cl− flux, which is noteworthy considering antidiarrheal drugs often target secretory processes. Also, rates of Cl− and I− absorption in DRA‐knockout mice were decreased by 79% and 50%, respectively, in the ceca, and 65% and 34% in the distal colon, suggesting this Cl− transporter may have a previously unrecognized role in I− uptake. In summary, we demonstrated 125I− is an adequate, cost‐effective alternative for tracing unidirectional Clfluxes across the intestinal epithelium. For example, the amount of 36Cl− used in this study cost $536 compared to a mere $4 worth of 125I−, thus making future research into epithelial Cltransport accessible. In addition, this study also provides insight into mechanisms of net Clsecretion and suggests that DRA may have a role in intestinal I− absorption.Support or Funding InformationThis study was supported by grants DK088892 and DK108755 to M. Hatch from the National Institutes of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Genetic disruption of guanylyl cyclase/natriuretic peptide receptor‐A upregulates renal (pro)renin receptor expression in Npr1 null mutant mice
Authors: Periyasamy Ramu , Das Subhankar , Pandey Kailash N 
Published: June 2021

Atrial and brain natriuretic peptides (ANP and BNP) activate guanylyl cyclase/natriuretic peptide receptor‐a (GC‐A/NPRA), which regulates blood pressure through inhibition of renin‐angiotensin‐aldosterone system (RAAS). The aim of the present study was to determine whether targeted‐disruption of Npr1 (encoding GC‐A/NPRA) upregulates pro(renin) receptor (P)RR expression and leads to activation of MAPKs in Npr1 gene‐knockout mice. The Npr1 homozygous (Npr1−/−; 0‐copy), heterozygous (Npr1+/−; 1‐copy), wild‐type (Npr1+/+; 2‐copy), and gene‐duplicated homozygous (Npr1++/++; 4‐copy) mice were utilized. The renal expression of (P)RR, ACE‐1, and AT1R were analyzed. To identify the canonical pathway of (P)RR, we administered ACE‐1 inhibitor (captopril), AT1R inhibitor (losartan), and MAPKs inhibitors (U0126 and SB203580) to all Npr1 mice. The renal expression of (P)RR was increased by 3‐fold in 0‐copy and 2‐fold in 1‐copy mice compared with 2‐copy mice, which was also associated with increased expression of ACE‐1 and AT1R genes. Similarly, the renal expression of phosphorylated MAPKs (p‐Erk1/2 and p‐p38) were enhanced by 3.5‐fold and 3‐fold, respectively, in 0‐copy mice with significant increases in 1‐copy mice compared with 2‐copy mice. Proinflammatory cytokines were also significantly elevated in Npr1 0‐copy and 1‐copy mice. Treatment with captopril and losartan did not alter the expression of (P)RR in any of the Npr1 mice genotypes. Interestingly, losartan significantly reduced the expression of p‐ERK1/2 and p‐p38 in the Npr1 mice genotypes. The present findings suggest that ablation of Npr1 upregulates (P)RR, MAPKs (p‐Erk1/2 and p‐p38), and proinflammatory cytokines in 0‐copy and 1‐copy mice. In contrast, the duplication of Npr1 gene copy exhibited anti‐inflammatory and antihypertensive effects by reducing the expression of RAAS components, MAPKs, and proinflammatory cytokines.Support or Funding InformationThis work was supported by NIH grants (HL057531 and HL062147).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hormonal Regulation of Estrogen Receptors
Authors: Wilkinson Mary Margaret , Lindsey Sarah H. 
Published: June 2021

BackgroundWe previously showed that estrogen has beneficial effects on cardiovascular function via the novel G‐protein coupled estrogen receptor (GPER). Selectively activating GPER may elicit beneficial cardiovascular effects of estrogen without eliciting deleterious effects. Receptor expression is important in developing targeted pharmacological therapies, but the regulation and expression of estrogen receptors is still not fully understood.ObjectiveOur goal was to study the effects androgens, glucocorticoids, and progesterone on the expression of the classical estrogen receptor ERα and novel estrogen receptor GPER.MethodsMouse aortic smooth muscle cells (MOVAS) were grown in 10% FBS media to 80% confluency and then starved for 24 h in charcoal‐stripped 0.5% FBS. The plates were treated for 24 h with 100 nm of dexamethasone (DEX), dihydrotestosterone (DHT), medroxyprogesterone acetate (MPA), or vehicle. After treatment, RNA was extracted and droplet digital PCR was used to quantify the expression of both GPER and ERα. Results were analyzed using a one‐way ANOVA.ResultsGPER expression was decreased by both DHT (66% of control, p=0.006, n=9) and MPA (70% of control, p=0.012, n=6). The impact of DEX on GPER was not statistically significant (89% of control, p=0.245, n=9). ERα expression was significantly reduced by DEX (65% of control, p=0.0046, n=9), DHT (56% of control, p=0.004, n=9), and MPA (52% of control, p=0.005, n=6) as compared to controls.ConclusionsIn cultured vascular smooth muscle cells, DHT and MPA decreased the expression GPER, while DEX, DHT, and MPA downregulated ERα. These results suggest that androgens, glucocorticoids, and progesterone act at the transcriptional level to decrease the expression of GPER and ERα. This decrease in receptor expression could lessen beneficial effects of GPER and/or ERα on cardiovascular function. Future studies will address the impact of androgens, glucocorticoids, and progesterone on the molecular mechanisms and in vivo cardiovascular responses to estrogen. The regulation of estrogen receptor expression is important for understanding the clinical interactions that may alter the response to hormone therapy.Support or Funding InformationFunding was provided by NIH HL133619 to SHL.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.