bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of Salt‐Sensitive Hypertension in a Mouse Model of ACTH‐Dependent Cushing Syndrome
Authors: Costello Hannah M , Stewart Kevin , Jones Natalie K , Grenier Celine , Ralph Ailsa F , Livingstone Dawn E W , Dhaun Neeraj , Bailey Matthew A 
Published: June 2021

Salt‐sensitive blood pressure (BP) reflects underlying renal and vascular (endothelial) dysfunction. People with abnormal glucocorticoid homeostasis, such as in Cushing syndrome and obesity, are often salt‐sensitive but the underlying mechanisms are not clearly defined1,2. Here, we used a mouse model to examine the effect of ACTH excess on blood pressure and salt‐sensitivity. To test this, radio telemetry was used to track BP longitudinally and measure the effect of high salt diet before and after chronic ACTH treatment in C57BL/6J mice (n=6). Data are mean ± SD. After 7 days of baseline measurements, mean BP was 105.8 ± 6.5mmHg before being placed on a high salt diet (3 % Na+ by weight) for a further 7 days. BP increased ~12 mmHg over the first 3 days before declining to 113.1 ± 7.2mmHg. BP returned to 107.7 ± 10.4mmHg, similar to baseline, after a 5‐day washout period. Mice were then treated with ACTH (2.5μg/day). ACTH increased mean BP to 115.5 ± 5.0mmHg with a flattening of the diurnal rhythm following 13 days infusion. When placing these mice on a high salt diet, mean BP increased and stabilised to 136.1 ± 13.4mmHg after 14 days. These data show that chronic ACTH excess contributes to salt‐sensitivity. To investigate potential mechanisms of salt‐sensitivity, the acute pressure natriuresis (PN) response of renal artery function were examined in separate cohorts of mice treated with either vehicle or ACTH (2.5μg/day; n=6 per group) for 14 days. PN response was induced in anaesthesised mice (120mg/kg Inactin) by sequential arterial ligation. BP increased ~40mmHg following ligations in both vehicle and ACTH groups. In vehicle‐treated mice, fractional sodium excretion increased from 0.2 ± 0.2 to 5.0 ± 4.2μmol/min. The natriuretic response was significantly blunted in ACTH‐treated mice, reaching 2.1 ± 1.1μmol/min at its peak. We next investigated vascular function in ACTH‐excess ex vivo by wire myography in isolated mesenteric and renal arteries. Vascular reactivity to phenylephrine (PHE), acetylcholine (ACh) and sodium nitroprusside (SNP) was assessed. ACTH‐excess caused vascular dysfunction in the renal artery but not in the mesenteric artery. ACTH‐excess resulted in a reduction in sensitivity to vasoconstrictor PHE (p=0.0005) and endothelium dependent (ACh) and endothelium independent (SNP) vasodilators (p=0.0128 and p=0.0002, respectively). These data show that chronic glucocorticoid excess contributes to salt‐sensitivity with potential mechanisms behind this being impairment of the acute natriuretic and diuretic response to increased BP and renal vascular dysfunction.Support or Funding InformationSupported by British Heart Foundation PhD studentships FS/16/54/32730 & FS/15/63/32033.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
GYY4137 Modulates Renal Remodeling in Hyperhomocysteinemia
Authors: John AM Sashi Papu , Sen Utpal 
Published: June 2021

IntroductionElevated plasma levels of homocysteine, also known as hyperhomocysteinemia (HHcy), is associated with chronic kidney disease and end‐stage renal failure. HHcy is also a vascular risk factor that causes glomerular remodeling by inducing and accumulating extracellular matrix (ECM) in the glomerular and peri‐glomerular spaces. This remodeling is, in part, due to Hcy‐mediated imbalance between matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) and disruption of cell‐to‐cell gap junction protein, connexins (Cxs). HHcy also contribute to renal microvascular impairment and vasoconstriction due to decreased endogenous hydrogen sulfide (H2S) production and homocysteinylation of endothelial nitric‐oxide synthase (eNOS). However, the molecular events targeting Caveolin, eNOS, MMPs/TIMPs, Cxs and the role of H2S in HHcy associated ECM turnover and renovascular remodeling remain elusive.HypothesisWe investigated whether GYY4137, slow releasing H2S donor ameliorates HHcy effect and renal remodeling.MethodsCaveolin protein 1 knockout B6.Cg‐Cav1 (Cav1−/ −), C57BL6/J (WT) and hyperhomocysteinemic CBS+/− mice were supplemented without or with Hcy (2% in diet) and treated without or with GYY4137 (0.5 mg/Kg/d, IP) for a period of 8 weeks.ResultsHHcy decreased plasma H2S levels, upregulated Cav1 and decreased eNOS activity in the kidney. HHcy also resulted in the upregulation of mRNA and protein levels of MMPs −1, 2, −9, −8, −13 as well as connexins – 40 and −43 and decreased the activities of (TIMPs) −1, −2, −3, −4. Immunohistochemistry results indicated increased collagen IV deposition and expression of connexins in the glomerular and interstitial areas. GYY4137 treatment mitigated these changes in HHcy. In conclusion, our data suggests that H2S alleviates renovascular remodeling by modulating Cav‐1, eNOS, MMPs/TIMPs and Cxs in HHcy.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mitochondrial Dysfunction and Metabolic Reprogramming in Chronic Kidney Disease
Authors: Li Ying , Pham Hai , Singh Prabhleen 
Published: June 2021

Chronic kidney disease (CKD) is a leading cause of death in the U.S. With limited treatment options, the disease progresses to end‐stage renal disease (ESRD), which is also associated with significant morbidity and mortality. Better understanding of the mechanisms which underlie the progression of CKD is indispensable for developing novel treatments to slow or halt the progression of CKD. Towards this goal, we examined the role of mitochondrial function and metabolic reprogramming in renal tubules in the development and progression of CKD using the subtotal nephrectomy (STN) model of CKD.Weight and age‐matched male 129X1/SvJ mice underwent either sham or STN surgeries. Tubular mitochondrial respiration at 2 and 4 weeks post‐surgery were evaluated using a high‐throughput Seahorse XF Analyzer. Renal expression of genes regulating mitochondrial biogenesis, dynamics, and metabolism at 4 weeks post‐surgery were measured by real‐time PCR. The mitochondrial respiration were similar between sham and STN groups at 2 weeks post‐surgery. However, at 4 weeks post‐surgery, the basal, the ATP‐linked, and the maximum respiration were significantly reduced in the STN tubules compared with sham (Figure 1A). Reduction of renal oxidative respiration indicates an impairment of mitochondrial function in STN renal tubules. Interestingly, the expression level of glycolytic mRNA, including phosphofructokinase (PFK, a rate‐limiting enzyme of glycolysis), glycolytic pyruvate kinase (PKM), and Hexokinase‐1 (HK1) were all significantly increased (Figure 1B–D), while expressions of carnitine palmitoyltransferase I (CPT1, a rate limiting enzyme of lipid oxidation), and peroxisomal acyl‐coenzyme A oxidase 1 (acox 1) remained unchanged.In conclusion, we observed compromised mitochondrial function and metabolic switch from oxidative respiration to glycolysis at 4 weeks post‐STN. Additional studies to further delineate mitochondrial functional changes and switch in tubular metabolism are ongoing. Mitochondrial dysfunction and metabolic reprogramming may contribute to the development and/or progression of CKD. Therapeutic strategies which improve mitochondrial function and inhibit metabolic reprogramming pathway may serve as novel therapeutic targets in CKD treatment.Support or Funding InformationVA Merit Award BX002175 and NIH R01 DKDK107852This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Renal TH17 cells are Elevated in Humanized Sickle Cell Mice
Authors: Molina Patrick Axel , Fox Brandon M. , De Miguel Carmen , McMonigle Ryan J. , Botta Davide , Huang Fengyuan , Kasztan Malgorzata , Pollock David M. , Pollock Jennifer S. 
Published: June 2021

Sickle cell nephropathy (SCN) is a major complication of sickle cell disease (SCD). However, it is not fully understood what role immune cells play in SCN. Recent studies have implicated IL‐17A+CD4+(TH17) cells in mediating kidney disease outside of SCD. Furthermore, levels of circulating TH17 cells are elevated in SCD patients. We have previously reported that humanized sickle cell (HbSS) mice show progressive age‐dependent nephropathy with proteinuria, glomerulosclerosis, loss of GFR, and elevated CD3+cells compared to control (HbAA) mice. However, a role for renal TH17 cells in SCN has not yet been defined. We hypothesized that HbSS mice have elevated renal TH17 cells compared to HbAA mice. Thus, we phenotyped renal and splenic lymphocytes from 16–24 week‐old male HbAA and HbSS mice by flow cytometry. HbSS mice had increased renal TH17 cells compared to HbAA mice (18.3 ± 2.0% vs. 0.2 ± 0.1%, respectively; p<0.001) but no difference in renal CD4+cells. No differences were observed in splenic TH17 cells between HbSS and HbAA mice, which correlated with similar frequencies of splenic CD4+cells. Interestingly, HbSS mice had a significant increase in renal CXCR3+CD4+(TH1) cells compared to HbAA mice (48.8 ± 2.3% vs. 10.9 ± 3.3%, respectively; p<0.001) but no difference in splenic TH1 cells. Next, we measured changes in circulating proinflammatory mediators by Luminex multiplex technology. HbSS mice had elevated levels of soluble intercellular adhesion molecule 1 (sICAM‐1: 2937 ± 240 ng/mL vs. 2396 ± 57 ng/mL, respectively; p=0.04 ) and plasminogen activator inhibitor 1 (PAI‐1: 546.9 ± 120 ng/mL vs. 69.6 ± 4.5 ng/mL; p=0.001 ) compared to HbAA mice. We conducted a preliminary flow cytometric analysis of activated renal and splenic CD4+cells from aged (8–13 month‐old) mice and observed decreased splenic CD4+cells in aged HbSS mice compared to aged HbAA mice (5.1% vs. 32.5%, respectively; n = 2) but no differences in renal CD4+cells. Activated CD44hiCD4+cells from aged HbSS mice were increased in both the spleen (68.8% vs. 30.8%; n = 2) and the kidney (22.2% vs. 14.0%, respectively; n = 2) compared to aged HbAA mice. We propose that these findings and initial observations suggest an important role for renal T cells, especially TH17 and TH1 cells, in promoting and exacerbating kidney injury and dysfunction in SCD.Support or Funding InformationSupport provided by NIH T32 DK116672 to PAM, F30 DK107194 to BMF, NIH P01 HL136267 to CDM, JSP, DMP, NIH T32 AR069516 to RJM, NIH U01 HL117684 to JSP, DMP, and ASN Ben J. Lipps Research Fellowship to MK.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Acetazolamide Administration Restores the Blood Pressure Lowering Effect of Tempol in Female SHR
Authors: Zuchowski Yvonne , Fernandez Edgar David Torres , Subauste1 Alessandro , Zhang Huimin , Vinson Ruth Michelle , Cardozo Licy Yanes , Reckelhoff Jane F 
Published: June 2021

The mechanisms responsible for the sex differences in blood pressure (BP) in humans are not clear. Over the past several years, we have studied the spontaneously hypertensive rat (SHR) as a model of sex differences in BP control. Oxidative stress (OS) plays a major role in BP regulation in preclinical studies. There is a sex difference in the BP responses to pro‐oxidants and antioxidants in the SHR. In contrast to males, BP in female SHR does not decrease in response to Tempol or Apocynin. Acetazolamide (Aceta) inhibits proximal tubular sodium reabsorption, increasing sodium delivery to the distal tubule which increases distal tubule OS. We tested the hypothesis that an increase in sodium delivery in the distal tubule will restore the BP lowering effects of Tempol in female SHR.Materials and MethodsFemale SHR, aged twenty weeks, were implanted with radiotelemetry transmitters and following a two week recovery period, baseline mean arterial pressure (MAP) was measured 24 hrs per day. All rats were then given Aceta (100 mg/kg/day sc) for 14 days (n=14). After this period, a group of rats were randomized to receive Tempol (1mmol/L) in drinking water for an additional two weeks (Aceta + Tempol) (n=7/grp) and BP was compared to controls who received Aceta only (n=7/grp). MAP was measured continuously throughout the treatment periods.ResultsAt baseline, MAP was similar in both groups of female SHR (144 ± 1 vs. 145 ± 1 mmHg). Aceta administration for two weeks caused a 10 mmHg reduction in MAP, which was similar in both group of rats (132 ± 1 vs. 131 ± 1 mmHg, p=0.43). Tempol administration significantly lowered MAP in presence of Aceta (138 ± 1vs. 122 ± 1 mmHg, p<0.0001). Body weight was similar between Aceta and Aceta + Tempol groups (200.3 ± 2.0g vs. 192.2 ± 4.0 g).In conclusion, our data suggest that there are sex differences in proximal sodium reabsorption that may impact OS in SHR. By increasing sodium delivery to the distal nephron with acetazolamide, the BP lowering effect of Tempol is restored in female SHR. These data suggest that different mechanisms may control oxidative stress and blood pressure in male and female SHR.Support or Funding InformationThis project was funded by NIH R01 HL135089, P20 GM12334, & PO1HL51971This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Basolateral Calcium Sensing Receptor Mediated Regulation of TRPV6‐dependent Transcellular Calcium Absorption
Authors: Lee Justin , Liu Xiong , O'Neill Debbie , Beggs Megan R , Weissgerber Petra , Flockerzi Veit , Chen Xing‐Zhen , Dimke Henrik , Alexander Todd 
Published: June 2021

The plasma concentrations of ionized calcium (Ca2+) is maintained within a narrow physiological range by amending the release of parathyroid hormone and through direct effects of the calcium sensing receptor (CaSR) on the renal tubule. Combined, these mechanisms alter intestinal Ca2+ absorption via 1,25‐dihydroxy vitamin D3, bone resorption, and renal Ca2+ excretion. The CaSR is also expressed in intestinal epithelium, but its function with respect to intestinal Ca2+ absorption are unknown. In the present study, we describe a mechanism by which the intestine detects and regulates Ca2+ absorption. Chronic CaSR activation decreased the expression of genes driving transcellular Ca2+ absorption, with the greatest effect observed in the proximal colon. To directly assess Ca2+ fluxes across the proximal colon, radioactive tracer experiments were performed ex vivo in Ussing chambers. Increased extracellular Ca2+ or basolateral application of the calcimimetic cinacalcet decreased net Ca2+ absorption acutely. Conversely, Ca2+ absorption was increased when the extracellular buffer was switched to one containing a lower Ca2+ concentration. These responses were absent in mice expressing a non‐functional TRPV6, TRPV6D541A. Cinacalcet also attenuated Ca2+ fluxes through TRPV6 in Xenopus oocytes when co‐expressed with the CaSR. Moreover, the phospholipase C inhibitor, U73122, prevented cinacalcet‐mediated inhibition of Ca2+ flux in both Xenopus ooctyes and murine proximal colon. Together, our results reveal a novel regulatory pathway whereby activation of the CaSR in the basolateral membrane of the proximal large bowel attenuates Ca2+ absorption via genomic and non‐genomic regulation of TRPV6 to prevent hypercalcemia.Support or Funding InformationThis work was funded by the Canadian Institute of Health Research, the Natural Sciences and Engineering Research Council, and the Women and Children's Health Research Institute.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Kidney Specific BMAL1 Knockout Exhibit Sex‐dependent Differences in the Expression and Activity of Renal H, K‐ATPases
Authors: Crislip Gene Ryan , Lynch I. Jeanette , Douma Lauren G , Masten Sarah H. , Cheng Kit‐Yan , Esser Karyn A , Wingo Charles S. , Gumz Michelle L. 
Published: June 2021

Two isoforms of the Hydrogen, Potassium‐ATPases, HKa1 and HKa2, located in the cortical collecting duct (CCD) are important in acid‐base regulation and potassium handling and are encoded by ATP4a and ATP12a, respectively. Elabida et al. has reported that progesterone mediates antikaliuretic effects via stimulation of HKa2 expression. The circadian clock influences kaliuresis as demonstrated by its 24‐hour cycles. Therefore, the objective of this study was to determine whether expression of the clock gene BMAL1 affected HK activity and if there was a difference in females compared to males.Kidney‐specific BMAL1 knockout mice (KO) were generated using floxed exon 8 BMAL1 mice crossed with kidney‐specific cadherin Cre+ mice. Floxed Cre− littermates were used as control mice (CNTL). Kidneys were collected for qPCR or CCD isolation. HK‐mediated H secretion in isolated perfused CCD was measured as EIPA‐ and bafilomycin A1‐insensitive intracellular pH (pHi) recovery from an acute H loading (NH4) using BCECF. pHi recovery was measured in A‐ and B‐type intercalated cells (IC) from female and male mice. IC type were differentiated based on the pHi response to peritubular Cl removal.Female mice had 2.3 fold greater ATP12a mRNA in the cortex than males (PSEX=0.008; N=4–6) and greater cortical ATP4a mRNA than males (1.5 fold; PSEX<0.0001), however, there was no genotype difference. Furthermore, the expression of BMAL1 affected ATP4a expression in a sex‐dependent manner (PSEX*KO=0.02). Overall, ICs from female mice exhibited faster rates of HK‐mediated H flux than males (4.3 ± 0.5 vs. 2.9 ± 0.3 H/min, PSEX<0.02, NIC/CCD=108/11 & 103/10). We observed a heterogeneous IC cell population with the number of A‐type ICs increasing (and B‐cells decreasing) from the outer to the inner CCD (P<0.001). We systematically analyzed HK activity in A‐ & B‐type ICs from the outer to the inner CCD. Female KO mice had 2.5 fold greater HK activity than female CNTL in A‐type ICs from mid and inner CCD (2.8 ± 0.6 vs. 6.9 ± 1.0, N=23/4 & 23/4, PKO<0.001).In conclusion, these data demonstrated a sex‐dependent difference in mRNA expression and HK activity. HKa1 and HKa2 mRNA expression and HK activity in females are greater than in males. HK activity is upregulated in the acid secreting ICs in female BMAL1 KO mice compared with controls. The clock gene BMAL1 has a sex‐specific role in regulating cortical mRNA expression of HKa1 and HK‐activity.Support or Funding Information5T32HL083810‐10NIH/NIDDK 1R01DK109570The 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.
Evaluation of Renin Angiotensin System (RAS) in Renal Transplant Patients
Authors: Bochio Filipo , Felipe Claudia Rosso , Aragão Danielle Sanches , Brandão Juliana Dinéia Perez , Pestana José Osmar Medina , Junior Helio Tedesco Silva , Casarini Dulce Elena 
Published: June 2021

Kidney transplantation is a surgical process that involves swapping the diseased kidney for a healthy kidney. In Brazil, about 5500 transplants per year are performed. After the transplantation process, the patients started to use immunosuppression therapy for acute rejection prophylaxis. There are two immunosuppressants that are most commonly used, Everolimus, Tacrolimus and Sodium Mycophenolate. Current immunosuppressive regimens are effective in preventing acute rejection but have several adverse events. Among them, hypertension and diabetes probably occurred due to an imbalance in RAS. In view of the above observations, the objective of this study was to verify the expression of the proteins and peptides of the RAS, in order to understand if there were changes in the modulation of the same. Two groups of patients, diabetics (n=10) and non‐diabetics (n=10), all with the underlying disease, hypertension, were analyzed. For this purpose, patients were collected at different times after transplantation: seven days (D7), fourteen days (D14), one month (M1), two months (M2), three months (M3), four months M4), five months (M5) and six months (M6). Patient plasma was prepared separately for albumin removal, and subjected to HiScreen Blue FF (GE Healthcare) (1 × 4.7 ml) affinity column chromatography coupled to Akta FPLC system and equilibrated with 50 mM Monopotassium Phosphate buffer, pH 7.0, under flow rate of 1.0 mL/min. The purification of the samples analyzed for one patient is in the table above.Purified plasma in different times was submitted to western blotting in order to demonstrate the expression of angiotensin converting enzyme (ACE). In the table above, we can see that the ACE expression increased gradually in the times of D7 to M6, coinciding with the detection of more pronounced hypertension in this patient (M6). This pilot study suggests that the healthy kidney is likely to be physiologically modified as a result of medications received by the patient, immunological modulations, leading to hypertension and that RAS is involved in this profile.Support or Funding InformationCAPES and CNPq

Purification

Sample (days)
D7
D14
M1
M2
M3
M4
M5
M6

Times (x)
15,65
12,40
15,40
12,87
14,32
16,55
10,72
17,30

Protein Expression (Arbitrary Units)

Expression ACE 190
0,933
1,119
1,390
2,483
2,630
2,517
2,545
4,755

90
0,846
1,200
1,183
1,587
1,839
2,167
2,310
3,158

65
1,625
1,376
1,246
1,420
1,702
1,775
1,687
2,047

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.