bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Gemfibrozil on the Progression of Proteinuria in Obese Dahl Salt‐Sensitive Rats
Authors: Shields Corbin Anthony , Poudel Bibek , Browning Evan , Williams Jan Michael 
Published: June 2021

The prevalence of obesity has increased dramatically within the last decade and is now considered an independent risk factor for chronic kidney disease (CKD). Recently, we reported that obese Dahl salt‐sensitive leptin receptor mutant (SSLepRmutant) rats exhibit dyslipidemia and renal injury independent of hyperglycemia that progresses to CKD. Interestingly, the kidneys from the SSLepRmutant strain displayed increased renal triglycerides and significant glomerular injury including podocyte foot process effacement and lipid droplets. Lipid‐lowering drugs such as fibrates have proven to be renoprotective in various models of kidney disease. Therefore, in the current study, we tested the effects of gemfibrozil, a fibrate, on the progression of renal injury in SSLepRmutant rats. Twelve‐week‐old SSWT and SSLepRmutant rats were separated into four groups (n=4 in each group): (1) SSWT and (2) SSLepRmutant rats treated with vehicle and (3) SSWT and (4) SSLepRmutant rats treated with gemfibrozil (200 mg/kg/day, orally, powdered food) for 4 weeks. Treatment with gemfibrozil had no effect on body weight or blood glucose levels in SSWT and SSLepRmutant rats. We observed greater than a 10‐fold increase in plasma triglyceride levels in the SSLepRmutant strain versus the values measured in SSWT rats (1265±380 and 117±19 mg/day, respectively). Gemfibrozil treatment significantly reduced plasma triglycerides by 64% in SSWT rats (41±20 mg/dL) and 57% in the SSLepRmutant strain (549±108 mg/dL). During the course of the study, proteinuria rose from 89±26 and 416±11 mg/day to 181±46 and 675±47 mg/day in SS and SSLepRmutant rats, respectively. Chronic treatment with gemfibrozil markedly decreased the progression of proteinuria by 52% in SSWT rats (87±17 mg/day) and 43% in the SSLepRmutant strain (385±75 mg/day). The kidneys from vehicle‐treated SSLepRmutant rats displayed significant glomerular injury with mesangial expansion and increased interstitial fibrosis and tubular protein casts compared to SSWT rats. Gemfibrozil treatment markedly decreased these renal abnormalities in both strains. These data indicate that reducing plasma lipid levels with gemfibrozil prevents the progression of proteinuria in both lean SSWT and obese SSLepRmutant rats.Support or Funding InformationThis study was supported by GM104357 and DK109133.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Increased Renal Expression of Adhesion Molecules and Inflammation in Diabetic Nephropathy
Authors: FAN LETAO , He Xiaochen , Muroya Yoshikazu , Fan Fan , Roman Richard J. 
Published: June 2021

Diabetic nephropathy (DN) is the primary risk factor for end‐stage renal disease (ESRD). Previously, we reported that the T2DN rat develops hyperglycemia by 3 months of age, proteinuria by 6 months and progressive renal injury which closely mimics human diabetic nephropathy, including focal glomerular sclerosis, mesangial matrix expansion, thickening of basement membranes, and progressive renal interstitial fibrosis. However, the role of adhesion molecules and renal inflammation in the pathogenesis of DN in this model has not been studied. In the present study, we compared the expression of cytokine and adhesion molecules, as well as the infiltration of inflammatory cells in young (3‐month old), middle‐aged (12‐month old) and elderly (18‐month old) T2DN and SD rats. We found that the expression of the adhesion molecules, ICAM‐1 and E‐selectin, were elevated in elderly T2DN (1.3‐fold and 1.8‐fold, respectively), and E‐selectin level was already higher in young T2DN (2.1‐fold) than in age‐matched SD rats. The number of infiltrating CD45+ leucocytes, CD3+ T cells, CD3−/CD4+ monocytes and CD68+ macrophages per gram of kidney were increased by 2.81±0.45, 2.82±0.44, 3.06±1.05, and 7.86±3.75 times, respectively, in elderly T2DN versus SD control. The rise in infiltrating inflammatory cells was correlated with elevated proteinuria (1144±202 in T2DN vs. 293±47 mg/day in SD) and plasma creatinine level (1.01±0.1 mg/dl in elderly T2DN vs. 0.50±0.02 mg/dl in SD), a greater degree of glomerular sclerosis and a 2‐fold increase in renal fibrosis in elderly T2DN rats versus age‐matched SD rats. These results indicate that the increased expression of adhesion molecules promotes infiltration of inflammatory cells, which is associated with the progression of DN and suggests that immune modulatory drugs may slow the progression of this disease.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypertension‐Induced Renal Injury is Associated with Impaired Glomerular Barrier Function Involving Podocyte Dysfunction
Authors: He Xiaochen , Chen Chun Cheng Andy , Murphy Sydney R. , Booz George W. , Roman Richard J. , Fan Fan 
Published: June 2021

Dahl SS rats rapidly develop hypertension, proteinuria, and renal injury when challenged with a high‐salt diet. Previous studies revealed that a deficiency in the renal formation of 20‐HETE in SS rats impairs afferent arteriole myogenic response, autoregulation of renal blood flow, tubuloglomerular feedback and glomerular capillary pressure and enhances sodium transport in the thick ascending loop of Henle. However, the role of 20‐HETE in podocyte and glomerular barrier function is still unknown. The aim of this study is to investigate the role of 20‐HETE on the regulation of glomerular function and podocyte function using SS rats and CYP4A1 transgenic rats on a SS background. We found that the production of 20‐HETE was significantly higher in the isolated glomeruli of CYP4A1 compared to SS rats by using mass spectrometry. Immunoblot analysis demonstrated that the expression of α‐smooth muscle actin and vimentin was lower in the isolated glomeruli of CYP4A1 vs. SS rats, indicating reduced epithelial mesenchymal transition (EMT). After challenged with a 4% high‐salt diet, the mean arterial pressure increased to a similar extent in both strains as measured by radio telemetry. However, compared with SS rats, CYP4A1 rats developed lower proteinuria (127 ± 14 vs. 270 ± 23 mg/day, respectively), had unaltered glomerular permeability to albumin (Palb) by using a fluorescence dilution technique, and exhibited greater increases in Palb after treatment with HET0016, a 20‐HETE synthesis inhibitor. In addition, Masson's trichrome staining showed that the glomerular injury score was attenuated in hypertensive CYP4A1 transgenic vs. SS rats (1.3 ± 0.2 vs. 2.4 ± 0.2, respectively), and the area of renal interstitial fibrosis was significantly lower in CYP4A1 transgenic vs. SS rats (6% ± 1% vs. 18% ± 4%, respectively). Moreover, hypertensive CYP4A1 rats exhibited less podocyte foot process effacement and detachment than SS rats when examined by a transmission electron microscopy. These findings indicate that increased production of 20‐HETE has renoprotective effects in association with decreased EMT, preserved podocyte and glomerular barrier function. This study indicates that 20‐HETE is a potential novel pharmacological target and biomarker in hypertension and chronic kidney disease.Support or Funding InformationThis study was supported by grants HL36279 (RJR) and DK104184 (RJR), AG050049 (FF), P20GM104357 (RJR and FF) from the National Institutes of Health; 16GRNT31200036 (FF) from the American Heart Association.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Opioid Analgesics (Morphine, Fentanyl, and Sufentanil) and Trauma on Survival Time after Severe Conscious Hemorrhage in Rats
Authors: Klemcke Harold G , Calderon Mariam L , Rodriguez Cassandra M , Connor Brian S , Hinojosa‐Laborde Carmen 
Published: June 2021

BackgroundCurrently, opioid analgesics are not recommended for use on the battlefield for Soldiers with severe hemorrhage, although they are still used during such situations (Schauer et al., Prehosp Emerg Care 21: 744, 2017). Moreover, there have been few or no controlled, preclinical studies conducted using analgesic doses of fentanyl or sufentanil to support these guidelines. The current study was conducted to evaluate and compare effects of three opioid analgesics on survival after severe hemorrhage in conscious rats in the absence or presence of extremity trauma. We hypothesized that opioid drugs and trauma would both decrease survival time to severe hemorrhage.MethodsRats were randomly assigned to receive either 0.9% saline (S), 2.0 mg/kg morphine (M; 0.2 mg/100 μl), 10μg/kg fentanyl (F; 1 μg/100 μl) or 1μg/kg sufentanil (SuF; 0.1μg/100 μl). All rats (male; ~ 380grams) were surgically implanted with a carotid catheter. After 24 hours, rats were anesthetized briefly (10 min) to undergo soft tissue injury (crushing of the right gastrocnemius and semimembranosus muscles for 30 sec with forceps) and fibula fracture (T). Non‐trauma rats (NT) were anesthetized for 10 min only. Rats were allowed to awaken, and 90 min later underwent a conscious hemorrhage (~55% of blood volume) via the indwelling carotid catheter. At the end of hemorrhage, rats received either S, M, F, or SuF via the carotid catheter. Rats were observed for a maximum of 4 hr after the start of the 25 min hemorrhage.ResultsWithin each trauma group, neither survival times (p > 0.51) nor percent survival (p > 0.55) differed among treatment groups (Table 1). However, when combined across all treatment groups, T rats had a shorter (p = 0.013) survival time (137 min, SD 81, n = 24) and lower percent survival (33.3%; p = 0.02) than did NT rats (196 min, SD 72, n=23, 69.6%).ConclusionsAt the analgesic doses given–previously shown to ameliorate behavioral indices of pain in rats (Xiang, J Trauma Acute care Surg 85: S49, 2018) –opioid drugs tested did not affect survival after severe hemorrhage. Exacerbating effects of extremity trauma on survival after hemorrhage in our rat model portend the need for rapid treatment of patients with traumatic injury accompanied by hemorrhage.Support or Funding InformationFunding for this project was provided by the US Army CRMRP, JPC8, Applied Pain Research Programs, and USAMRMC.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Curcumin Does Not Attenuate the Preeclamptic Phenotype in the Dahl Salt‐Sensitive Rat
Authors: Ishimwe Jeanne A , Maeda Kenji J , Johnson Ashley C , Garrett Michael R , Sasser Jennifer M 
Published: June 2021

Preeclampsia (PE) is associated with new onset of hypertension and proteinuria and affects 2–8% of pregnancies worldwide. It is a leading cause of maternal and fetal morbidity and mortality with no current therapy to manage the disease. While its etiology is yet to be elucidated, immune system activation of various inflammatory pathways is reported to be a contributing factor. Toll‐like receptor (TLR) activation by damage‐associated molecular patterns (DAMPS) released following poor placentation and oxidative stress has been linked to the development of PE and TLR4 expression is increased in the placenta of preeclamptic women. We performed a whole transcriptomic analysis on placental tissues from gestation day (GD) 14 rats using Affymetrix Rat 2.0ST GeneChip and noted significant dysregulation in multiple genes during pregnancy in the Dahl salt sensitive (S) rat, a model of spontaneous superimposed preeclampsia, compared to the normal pregnant control Sprague Dawley (SD) rat. These genes included upregulation of TLR4 in the placenta of Dahl S rats (1.9 fold, p<0.05), which was subsequently confirmed via quantitative real‐time PCR (2.9 fold, p<0.05). To further investigate this pathway, the goal of this study was to assess the effect of TLR4 inhibition in pregnant Dahl S rats. Curcumin, the anti‐oxidant and anti‐inflammatory active ingredient in the spice turmeric, has been reported to inhibit TLR4 activation, and reduced blood pressure in rodent models of LPS‐induced preeclampsia. We hypothesized that curcumin would inhibit TLR4 activation and reduce blood pressure and uterine artery resistance index during pregnancy in the Dahl S rat. Starting on gestational day (GD) 10, 17 weeks old rats were divided into two groups: a treated group (N=7) that orally received dough containing 400mg/kg of curcumin daily and a control group (N=6) that received the vehicle dough through GD20. On GD18, Uterine Artery Resistance Index (UARI) was measured via Doppler ultrasound. On GD20, terminal blood pressure measurements were taken, and pups and placentas harvested and measured. Curcumin had no effect on UARI (0.78 vs. 0.82, p=0.4) or mean arterial pressure (146 ± 5 vs. 133 ± 5 mmHg, p=0.08). Fetal outcome assessed by litter size (10 ± 1 vs. 11 ± 1 pups); pup weight (2.23 ± 0.08 vs. 2.30 ± 0.07 g) and pup length (29.44 ± 0.31 vs. 29.6 ± 0.46 cm) was similar between groups. These results suggest that administration of curcumin does not alleviate the preeclamptic phenotype in the Dahl S rat.Support or Funding InformationR01HL1347111R01HL137673This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Connexin 37 contributes to water homeostasis and urinary concentrating ability
Authors: Xue Jianxiang , Rieg Jessica Ann Dominguez , Thomas Linto , Rieg Timo 
Published: June 2021

Connexin 37 (Cx37) is one gap junction component which plays an important role in intercellular communication. In the kidney, multiple gap junction proteins have been localized including Cx37. Previous studies have shown that Cx37 is expressed in a punctate pattern in the renal vasculature and along the nephron. Regarding the latter, strong basolateral expression was found in the thick ascending limb and distal convoluted tubule, weaker expression was found in the proximal tubule and collecting duct. Functional data are limited, with one study implying a role of Cx37 in sodium homeostasis. Based on its localization, we hypothesized that Cx37 possibly contributes to fluid homeostasis. In order to gain further insight, we studied wild‐type (WT, n=9–12) and Cx37 knockout mice (Cx37−/−, n=9–12). Under baseline conditions, Cx37−/− showed a ~40% higher fluid intake (5.7±0.3 vs 4.2±0.3 mL/day, P<0.05) associated with a ~40% lower urine osmolality (1611±79 vs 2556±171 mOsm/kg, P<0.05) compared to WT mice. Plasma osmolality (Cx37−/−: 333±2 vs WT: 334±2 mOsm/kg, NS) and food intake (Cx37−/−: 4.0±0.2 vs WT: 3.7±0.2 g/day, NS) were not significantly different between genotypes indicating that Cx37−/− mice are in fluid balance. To determine the role of Cx37 in the urinary concentrating mechanism, we conducted 18‐hour water deprivation studies. In response to water deprivation, urine osmolality increased significantly in both groups but the increase remained ~375 mOsm/kg lower in Cx37−/− vs WT mice (3355±85 vs 3730±181 mOsm/kg, P<0.05), an effect associated with a more pronounced body weight loss (8.8±0.6 vs 7.2±0.5%, P<0.05) indicative of greater urinary water loss. The increase in plasma osmolality was not significantly different between Cx37−/− and WT mice (Δ change: 14±3 vs 11±2 mOsm/kg, NS). Consistent with greater thirst, fluid intake in the first 6 hours after water deprivation was significantly greater in Cx37−/− vs WT mice (4.1±0.4 vs 3.0±0.3 mL, P<0.05). In summary, these results demonstrate that expression of Cx37 is important for urinary concentration in vivo, including in response to water restriction.Support or Funding InformationTR is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK110621). JX was supported by an American Heart Association Predoctoral Fellowship (18PRE33990236) and LT by a Postdoctoral Fellowship (19POST34400026).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Estrogen Modulates the Differential Expression of Cardiac Myocyte Chymase Isoforms and Diastolic Function
Authors: Wang Hao , Sun Xuming , Ahmad Sarfaraz , Su Jing , Ferrario Carlos M , Groban Leanne 
Published: June 2021

Background and objectiveCardiac angiotensin II (Ang II) is involved in the diastolic dysfunction in postmenopausal women. Chymases, a family of serine proteases with chymotryptic activity, play a significant role in cardiac Ang II formation from its substrate Ang‐(1–12) in both human and rodent models. While human tissue expresses only the α‐form of chymase, α‐ and β‐forms exist in rodents. Five of the ten rat mast cell proteases (rMCP‐1–5) display chymase activity, and rats express predominantly the β‐chymase isoforms. This study was designed to assess the differences in enzymatic activity among these rMCP isoforms in Ang II formation, particularly in the cardiomyocyte (CM), and the effects of estrogen status on MCP gene expression and activities in female rat models.Methods and resultsUsing conventional polymerase chain reaction (PCR) (Fig. 1A), real‐time PCR (Fig. 1B) and DNA sequencing (Fig. 1C), we demonstrated that MCP‐1, MCP‐2, MCP‐4, and MCP‐5 mRNAs are expressed in the CM of both spontaneously hypertensive rats (SHR) and normotensive Wistar‐Kyoto rats (WKY). While rMCP‐1 and rMCP‐5 gene transcripts were higher than other isoforms in both rat strains, WKY CM exhibits higher levels of rMCP‐1 and rMCP‐5 mRNAs compared to the SHR CM (Fig. 2). Ovariectomy (OVX) increased the expression of rMCP‐1 and rMCP‐5 mRNAs in WKY. In SHR, OVX was associated with a blunted increase in rMCP‐1 mRNA compared to OVX normotensive WKY. Chymase activity, measured by HPLC as Ang II formation from Ang‐(1–12), significantly correlated with rMCP‐1 and rMCP‐5 mRNA expression in both rat strains. Both rMCP‐1 and rMCP‐5 mRNA expressions were positively correlated with progressive diastolic dysfunction (increasing the ratio of early mitral inflow velocity‐to‐early mitral annular velocity, E/e′) and increases in left ventricular internal diameter end diastole.ConclusionThese data show rMCP‐1 and rMCP‐5 as the Ang II forming chymase isoforms participating in diastolic dysfunction due to ovariectomy in rodents.Support or Funding InformationThis work was funded by grants from the National Heart Lung and Blood Institute (CMF and LG) P01‐HL051952 and the National Institute on Aging (LG) AG033727 of the National Institute 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.
Mast Cell Peptidases (Carboxypeptidase A and Chymase)‐Mediated Hydrolysis of Human Angiotensin‐(1‐12)
Authors: Ahmad Sarfaraz , Wright Kendra N , Varagic Jasmina , Groban Leanne , Ferrario Carlos M 
Published: June 2021

IntroductionAngiotensin processing peptidases [carboxypeptidase A (CPA) and chymase] are stored in cardiac mast cell secretory granules and are co‐released into the extracellular environment after activation/degranulation. In the human heart, we showed that chymase is primarily responsible for angiotensin II (Ang II) generation from the alternate substrate angiotensin‐(1‐12) [Ang‐(1‐12)], which is present in human heart. In this study, we investigated whether there are any synergistic effects of CPA and chymase in the processing of Ang‐(1‐12).MethodRadiolabeled human Ang‐(1‐12) [125I‐Ang‐(1‐12)] substrate was incubated with CPA alone (0.325 μg/mL), human recombinant chymase (hrChymase) (0.325 μg/mL) or a combination of CPA + hrChymase (1:1 or 1: ⅓ ratio) in 50 mM Tris‐HCl buffer solution containing 150 mM NaCl (pH 8.0) for 0–15 min at 37 °C. The reaction was stopped by adding an equal volume of 1% phosphoric acid and injected on a C18 column. Eluted 125I‐Ang‐(1‐12) metabolic products were quantified by HPLC connected to in‐line flow‐through gamma detector. To determine the Km and Vmax, CPA and hrChymase were incubated with increasing concentrations (0–300 μM) of human Ang‐(1‐12) substrate for 20 min at 37 °C. The Km and Vmax were calculated using the Michaelis‐Menten equation.ResultsWe found that after 15 min of incubation, CPA sequentially metabolized Ang‐(1‐12) substrate into angiotensin‐(1‐9) [Ang‐(1‐9), 53% (major product)], Ang II (22%) and angiotensin‐(1‐7) [Ang‐(1‐7), 11%]. No further hydrolysis of Ang‐(1‐7) was detected during CPA incubation. In the presence of hrChymase alone, 125I‐Ang‐(1‐12) was directly metabolized into Ang II (89%) and no further hydrolysis of Ang II was detected. In the presence of both CPA + hrChymase (1:1 ratio), the amount of Ang II formation was 68% from 125I‐Ang‐(1‐12) within a 5 min incubation period. The formation of Ang‐(1‐9) and Ang‐(1‐7) were only 11% and 10%, respectively. When CPA + hrChymase were added in 1: ⅓ ratio for 5 min, the Ang II, Ang‐(1‐9) and Ang‐(1‐7) formations were 65%, 27%, 6%, respectively. The Km and Vmax values were 150 ± 5 μM and 384 ± 23 nM/min/mg of CPA and 40 ± 9 μM and 116 ± 20 nM/min/mg of hrChymase.ConclusionsThese findings suggest that compared to CPA, chymase shows a much higher affinity to metabolize Ang‐(1‐12) into Ang II. In addition, Ang II and Ang‐(1‐7) are the end products of chymase and CPA, respectively. Overall, our findings suggest that chymase, rather than CPA, is primarily responsible for Ang II generation from Ang‐(1‐12).Support or Funding InformationThis work was supported by grant from the National Heart, Lung and Blood Institute of the National Institutes of Health (P01 HL‐051952).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.