51
|
Metse AP, Wiggers J, Wye P, Wolfenden L, Prochaska JJ, Stockings E, Williams JM, Ansell K, Fehily C, Bowman JA. Smoking and mental illness: a bibliometric analysis of research output over time. Eur J Public Health 2016. [DOI: 10.1093/eurpub/ckw165.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
52
|
Cunningham MW, Williams JM, Amaral L, Usry N, Wallukat G, Dechend R, LaMarca B. Agonistic Autoantibodies to the Angiotensin II Type 1 Receptor Enhance Angiotensin II-Induced Renal Vascular Sensitivity and Reduce Renal Function During Pregnancy. Hypertension 2016; 68:1308-1313. [PMID: 27698062 DOI: 10.1161/hypertensionaha.116.07971] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/23/2016] [Indexed: 01/26/2023]
Abstract
Preeclamptic women produce agonistic autoantibodies to the angiotensin II type 1 receptor (AT1-AA) and exhibit increased blood pressure (mean arterial pressure), vascular sensitivity to angiotensin II (ANG II), and display a decrease in renal function. The objective of this study was to examine the renal hemodynamic changes during pregnancy in the presence of AT1-AAs with or without a slow pressor dose of ANG II. In this study, mean arterial pressure was elevated in all pregnant rats treated with ANG II with or without AT1-AA. Glomerular filtration rate was reduced from 1.90±0.16 mL/min in normal pregnant (NP) to 1.20±0.08 in ANG II+AT1-AA rats. Renal blood flow was decreased in ANG II+AT1-AA versus NP rats to 7.4±1.09 versus 15.4±1.75 mL/min. Renal vascular resistance was drastically increased between ANG II+AT1-AA versus NP rats (18.4±2.91 versus 6.4±0.77 mm Hg/mL per minute). Isoprostane excretion was increased by 3.5-fold in ANG II+AT1-AA versus NP (1160±321 versus 323±52 pg/mL). In conclusion, ANG II and AT1-AA together significantly decrease glomerular filtration rate by 37% and renal blood flow by 50% and caused a 3-fold increase in renal vascular resistance and isoprostane levels versus NP rats. These data indicate the importance of AT1-AAs to enhance ANG II-induced renal vasoconstriction and reduce renal function as mechanisms to cause hypertension as observed during preeclampsia.
Collapse
|
53
|
Bean C, Spencer SK, Bowles T, Kyle PB, Williams JM, Gibbens J, Wallace K. Inhibition of T-cell activation attenuates hypertension, TNFα, IL-17, and blood-brain barrier permeability in pregnant rats with angiogenic imbalance. Am J Reprod Immunol 2016; 76:272-9. [PMID: 27476638 PMCID: PMC5023479 DOI: 10.1111/aji.12547] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/05/2016] [Indexed: 12/26/2022] Open
Abstract
PROBLEM Angiogenic imbalance during pregnancy is associated with immune activation, hypertension, increased T cell infiltration, and neurological insults. METHOD OF STUDY On gestational day (GD) 12, timed-pregnant rats were infused with anti-angiogenic factors sFlt-1 and sEndoglin (4.7 and 7 μg/kg) to create HELLP syndrome via mini-osmotic pumps for 8 days, with a subset of these rats having Orencia (2 mg/kg) infused on GD13. On GD19, blood-brain barrier (BBB) permeability was evaluated via Evan's Blue infusion, blood was collected for T-cell measurements, inflammatory cytokine secretion. Brain tissues were also collected to examine inflammatory cytokine infiltration. RESULTS T-cell attenuation with Orencia decreased circulating CD4(+) and CD8(+) T cells, circulating tumor necrosis factor alpha (TNFα) and IL-17, BBB permeability and significantly decreased biochemical evidence of HELLP compared to untreated HELLP rats. CONCLUSIONS These data support the hypothesis that T cells have a critical role in contributing to the pathophysiology that is seen in angiogenic imbalance during pregnancy.
Collapse
|
54
|
Lv W, Yu H, Li L, Taylor C, Gonzalez-Fernandez E, Sims J, Elliott MR, Wang Y, Williams JM, Roman RJ, Fan F. Abstract P243: A New Type 2 Diabetic Rat Model That is Associated with Cognitive Impairment in Aging. Hypertension 2016. [DOI: 10.1161/hyp.68.suppl_1.p243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alzheimer’s disease (AD) is an incurable neurodegenerative disease and the most common form of dementia, and AD and type II diabetes (DM II) are two of the most common diseases of aging. Numerous studies demonstrate DM II with increased risk for dementia, however, the mechanisms linking DM II and AD have not been fully elucidated. There is increasing evidence suggesting that cerebral vascular dysfunction plays an important role in the development of AD. T2DN rat is a DM II rat model that exhibits diabetic nephropathy. The present study examines whether aged T2DN rat is associated with cognitive impairment, and whether autoregulation of cerebral blood flow (CBF) is impaired that contributes to AD. The levels of glucose (422 ± 32 vs. 94 ± 3 mg/dL) and glycated hemoglobin (HbA
1c
, 11.5 ± 0.2 vs. 4.3 ± 0.1%) were higher in 12-18 months old T2DN than in age matched SD control rats. CBF rose by 137 ± 15% and 36 ± 5%, respectively, in T2DN and SD rats when MAP was increased from 100 to 180 mmHg. Aged T2DN rats exhibited BBB leakage and “AD” like cerebral vascular remodeling. The expression of Amyloid β 42 (Aβ
4
2
), p-tau (S416), GFAP and IL-1 beta were significantly higher in the brains of T2DN vs. SD rats. T2DN rats also exhibited learning and memory dysfunction as the short term (2-hour; T2DN 96 ± 12 vs. SD 13 ± 3 seconds) and long term (24-hour; T2DN 105 ± 15 vs. SD 8 ± 2 seconds) latency of escape were longer in an eight-arm water maze test, and spent less time in the target arm 48 hours after training (T2DN 3.4 ± 2.6 vs. SD 45.0 ± 1.7%). These findings indicate that T2DN is a new type II diabetic rat model. Elderly T2DN rat is associated with an impaired autoregulation of CBF, glial activation and inflammation which may contribute to the development of cognitive impairment and AD.
Collapse
|
55
|
McPherson KC, Taylor L, Johnson AC, Didion SP, Geurts AM, Garrett MR, Williams JM. Early development of podocyte injury independently of hyperglycemia and elevations in arterial pressure in nondiabetic obese Dahl SS leptin receptor mutant rats. Am J Physiol Renal Physiol 2016; 311:F793-F804. [PMID: 27465994 DOI: 10.1152/ajprenal.00590.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 07/25/2016] [Indexed: 01/05/2023] Open
Abstract
The current study examined the effect of obesity on the development of renal injury within the genetic background of the Dahl salt-sensitive rat with a dysfunctional leptin receptor derived from zinc-finger nucleases (SSLepRmutant strain). At 6 wk of age, body weight was 35% higher in the SSLepRmutant strain compared with SSWT rats and remained elevated throughout the entire study. The SSLepRmutant strain exhibited impaired glucose tolerance and increased plasma insulin levels at 6 wk of age, suggesting insulin resistance while SSWT rats did not. However, blood glucose levels were normal throughout the course of the study. Systolic arterial pressure (SAP) was similar between the two strains from 6 to 10 wk of age. However, by 18 wk of age, the development of hypertension was more severe in the SSLepRmutant strain compared with SSWT rats (201 ± 10 vs. 155 ± 3 mmHg, respectively). Interestingly, proteinuria was substantially higher at 6 wk of age in the SSLepRmutant strain vs. SSWT rats (241 ± 27 vs. 24 ± 2 mg/day, respectively) and remained elevated until the end of the study. The kidneys from the SSLepRmutant strain displayed significant glomerular injury, including podocyte foot process effacement and lipid droplets compared with SSWT rats as early as 6 wk of age. By 18 wk of age, plasma creatinine levels were twofold higher in the SSLepRmutant strain vs. SSWT rats, suggesting the presence of chronic kidney disease (CKD). Overall, these results indicate that the SSLepRmutant strain develops podocyte injury and proteinuria independently of hyperglycemia and elevated arterial pressure that later progresses to CKD.
Collapse
|
56
|
Miller B, Palygin O, Rufanova VA, Chong A, Lazar J, Jacob HJ, Mattson D, Roman RJ, Williams JM, Cowley AW, Geurts AM, Staruschenko A, Imig JD, Sorokin A. p66Shc regulates renal vascular tone in hypertension-induced nephropathy. J Clin Invest 2016; 126:2533-46. [PMID: 27270176 DOI: 10.1172/jci75079] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/19/2016] [Indexed: 11/17/2022] Open
Abstract
Renal preglomerular arterioles regulate vascular tone to ensure a large pressure gradient over short distances, a function that is extremely important for maintaining renal microcirculation. Regulation of renal microvascular tone is impaired in salt-sensitive (SS) hypertension-induced nephropathy, but the molecular mechanisms contributing to this impairment remain elusive. Here, we assessed the contribution of the SH2 adaptor protein p66Shc (encoded by Shc1) in regulating renal vascular tone and the development of renal vascular dysfunction associated with hypertension-induced nephropathy. We generated a panel of mutant rat strains in which specific modifications of Shc1 were introduced into the Dahl SS rats. In SS rats, overexpression of p66Shc was linked to increased renal damage. Conversely, deletion of p66Shc from these rats restored the myogenic responsiveness of renal preglomerular arterioles ex vivo and promoted cellular contraction in primary vascular smooth muscle cells (SMCs) that were isolated from renal vessels. In primary SMCs, p66Shc restricted the activation of transient receptor potential cation channels to attenuate cytosolic Ca2+ influx, implicating a mechanism by which overexpression of p66Shc impairs renal vascular reactivity. These results establish the adaptor protein p66Shc as a regulator of renal vascular tone and a driver of impaired renal vascular function in hypertension-induced nephropathy.
Collapse
MESH Headings
- Albumins/analysis
- Animals
- Arterioles/physiopathology
- Blood Pressure
- Calcium/metabolism
- Hypertension/physiopathology
- Hypertension, Renal/metabolism
- Hypertension, Renal/physiopathology
- Kidney/blood supply
- Kidney/physiopathology
- Kidney Glomerulus/metabolism
- Male
- Microcirculation
- Muscle, Smooth, Vascular/physiopathology
- Nephritis/metabolism
- Nephritis/physiopathology
- Promoter Regions, Genetic
- Rats
- Rats, Inbred BN
- Rats, Inbred Dahl
- Rats, Inbred WKY
- Rats, Transgenic
- Species Specificity
- Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism
- Vasoconstriction
Collapse
|
57
|
Wang X, Johnson AC, Sasser JM, Williams JM, Solberg Woods LC, Garrett MR. Spontaneous one-kidney rats are more susceptible to develop hypertension by DOCA-NaCl and subsequent kidney injury compared with uninephrectomized rats. Am J Physiol Renal Physiol 2016; 310:F1054-64. [PMID: 26936874 PMCID: PMC5002061 DOI: 10.1152/ajprenal.00555.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/25/2016] [Indexed: 12/12/2022] Open
Abstract
There is little clinical data of how hypertension may influence individuals with nephron deficiency in the context of being born with a single kidney. We recently developed a new rat model (the heterogeneous stock-derived model of unilateral renal agenesis rat) that is born with a single kidney and exhibits progressive kidney injury and decline in kidney function with age. We hypothesized that DOCA-salt would induce a greater increase in blood pressure and therefore accelerate the progression of kidney injury in rats born with a solitary kidney compared with rats that have undergone unilateral nephrectomy. Time course evaluation of blood pressure, kidney injury, and renal hemodynamics was performed in the following six groups of animals from weeks 13 to 18: 1) DOCA-treated rats with a solitary kidney (DOCA+S group), 2) placebo-treated rats with a solitary kidney, 3) DOCA-treated control rats with two kidneys (DOCA+C group), 4) placebo-treated control rats with two kidneys, 5) DOCA-treated rats with two kidneys that underwent uninephrectomy (DOCA+UNX8 group), and 6) placebo-treated rats with two kidneys that underwent uninephrectomy. DOCA+S rats demonstrated a significant rise (P < 0.05) in blood pressure (192 ± 4 mmHg), proteinuria (205 ± 31 mg/24 h), and a decline in glomerular filtration rate (600 ± 42 μl·min(-1)·g kidney weight(-1)) relative to the DOCA+UNX8 (173 ± 3 mmHg, 76 ± 26 mg/24 h, and 963 ± 36 μl·min(-1)·g kidney weight(-1)) and DOCA+C (154 ± 2 mmHg, 7 ± 1 mg/24 h, and 1,484 ± 121 μl·min(-1)·g kidney weight(-1)) groups. Placebo-treated groups showed no significant change among the three groups. An assessment of renal injury markers via real-time PCR/Western blot analysis and histological analysis was concordant with the measured physiological parameters. In summary, congenital solitary kidney rats are highly susceptible to the induction of hypertension compared with uninephrectomized rats, suggesting that low nephron endowment is an important driver of elevated blood pressure, hastening nephron injury through the transmission of elevated systemic blood pressure and thereby accelerating decline in kidney function.
Collapse
|
58
|
Fan F, Chen CCA, Zhang J, Schreck CMN, Roman EA, Williams JM, Hirata T, Sharma M, Beard DA, Savin VJ, Roman RJ. Fluorescence dilution technique for measurement of albumin reflection coefficient in isolated glomeruli. Am J Physiol Renal Physiol 2015; 309:F1049-59. [PMID: 26447220 PMCID: PMC4683305 DOI: 10.1152/ajprenal.00311.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/28/2015] [Indexed: 12/11/2022] Open
Abstract
This study describes a high-throughput fluorescence dilution technique to measure the albumin reflection coefficient (σAlb) of isolated glomeruli. Rats were injected with FITC-dextran 250 (75 mg/kg), and the glomeruli were isolated in a 6% BSA solution. Changes in the fluorescence of the glomerulus due to water influx in response to an imposed oncotic gradient was used to determine σAlb. Adjustment of the albumin concentration of the bath from 6 to 5, 4, 3, and 2% produced a 10, 25, 35, and 50% decrease in the fluorescence of the glomeruli. Pretreatment of glomeruli with protamine sulfate (2 mg/ml) or TGF-β1 (10 ng/ml) decreased σAlb from 1 to 0.54 and 0.48, respectively. Water and solute movement were modeled using Kedem-Katchalsky equations, and the measured responses closely fit the predicted behavior, indicating that loss of albumin by solvent drag or diffusion is negligible compared with the movement of water. We also found that σAlb was reduced by 17% in fawn hooded hypertensive rats, 33% in hypertensive Dahl salt-sensitive (SS) rats, 26% in streptozotocin-treated diabetic Dahl SS rats, and 21% in 6-mo old type II diabetic nephropathy rats relative to control Sprague-Dawley rats. The changes in glomerular permeability to albumin were correlated with the degree of proteinuria in these strains. These findings indicate that the fluorescence dilution technique can be used to measure σAlb in populations of isolated glomeruli and provides a means to assess the development of glomerular injury in hypertensive and diabetic models.
Collapse
|
59
|
McPherson K, Guillory D, Taylor L, Spires D, Johnson AC, Garrett MR, Williams JM. Abstract P020: Decreased Survival Rate in Female Obese Leptin Receptor Mutant Dahl Salt-Sensitive Rats that Develop Chronic Kidney Disease. Hypertension 2015. [DOI: 10.1161/hyp.66.suppl_1.p020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Obesity contributes to sex differences in the risk for chronic kidney disease (CKD) in which males tend to develop CKD earlier in life than females. Therefore, in the current study, we examined whether there were sex differences in the development of CKD in the obese leptin receptor mutant Dahl salt-sensitive (SS
LepR
mutant) strain which was derived from Zinc-finger nucleases. We observed an increase in body weight in both female and male SS
LepR
mutant rats when compared to SS rats throughout the study. Glucose tolerance was impaired significantly in female and male SS
LepR
mutant rats versus SS
rats by 18 weeks of age. The SS
LepR
mutant strain also developed hyperinsulinemia in comparison to their lean SS counterparts (6.86±0.83 vs 0.72±0.04 ng/mL, respectively, n=6). However, blood glucose in the SS
LepR
mutant strain remained within normal range throughout the course of the study regardless of sex. Female and male SS
LepR
mutant rats developed severe systolic hypertension (via tail-cuff) by 18 weeks of age when compared to the values measured in SS rats (199±7 and 201±10 vs. 159±5 and 155±4 mmHg, respectively, n=6). Yet, the rise in arterial pressure occurred earlier in female SS
LepR
mutant rats than males. Protein excretion was significantly higher in the SS
LepR
mutant strain as opposed to the values observed in SS rats at 18 weeks of age regardless of sex (488±61 and 631±86 vs. 50±17 and 149±23 mg/day, respectively, n=6). At the end of study, kidneys from the SS
LepR
mutant strain displayed increased glomerulosclerosis and interstitial fibrosis than SS rats. Female and male SS
LepR
mutant rats had a significant increase in plasma creatinine levels and averaged 2.1±0.4 mg/dL (n=6) compared to the normal value of 0.5±0.1 mg/dL (n=6) observed in the SS strain suggesting the presence of severe CKD. While both, female and male, SS rats survived the length of study, the survival rate of female SS
LepR
mutant rats was markedly reduced compared to their male counterparts (62%, 21 of 34 vs. 25%, 6 of 24, respectively). Overall, these data indicate that the SS
LepR
mutant strain may be a useful model to study sex differences during the development of CKD associated with obesity.
Collapse
|
60
|
Dorey CD, Williams JM. Hip muscle strengthening in patients with patellofemoral pain: Learning from the literature. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
61
|
Parkinson J, West D, Clark C, Williams JM. Is there a correlation between wobble board performance and static balance performance? INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s5a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
62
|
Williams JM. The learning of higher order manual therapy through real-time feedback. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s2b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
63
|
Bewes R, Williams JM. An investigation into the use of inertial sensors to quantify joint position sense. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s2a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
64
|
Williams JM, Dorey C, Clark S, Clark C. The clinical measurement of balance using accelerometry: Within- and between-day reliability. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2015. [DOI: 10.12968/ijtr.2015.22.sup8.s3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
65
|
Kojima N, Williams JM, Slaughter TN, Kato S, Takahashi T, Miyata N, Roman RJ. Renoprotective effects of combined SGLT2 and ACE inhibitor therapy in diabetic Dahl S rats. Physiol Rep 2015; 3:3/7/e12436. [PMID: 26169541 PMCID: PMC4552522 DOI: 10.14814/phy2.12436] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
This study examined whether control of hyperglycemia with a new SGLT2 inhibitor, luseogliflozin, given alone or in combination with lisinopril could prevent the development of renal injury in diabetic Dahl salt-sensitive (Dahl S) rats treated with streptozotocin (Dahl-STZ). Blood glucose levels increased from normoglycemic to hyperglycemic levels after treatment of STZ in Dahl S rats. Chronic treatment of Dahl-STZ rats with luseogliflozin (10 mg/kg/day) increased the fractional excretion of glucose and normalized blood glucose and HbA1c levels. Lisinopril (20 mg/kg/day) reduced blood pressure from 145 ± 9 to 120 ± 5 mmHg in Dahl-STZ rats, while luseogliflozin had no effect on blood pressure. Combination therapy reduced blood pressure more than that seen in the rats treated with luseogliflozin or lisinopril alone. Dahl-STZ rats exhibited hyperfiltration, mesangial matrix expansion, severe progressive proteinuria, focal glomerulosclerosis and interstitial fibrosis. Control of hyperglycemia with luseogliflozin reduced the degree of hyperfiltration and renal injury but had no effect on blood pressure or the development of proteinuria. Treatment with lisinopril reduced hyperfiltration, proteinuria and renal injury in Dahl-STZ rats. Combination therapy afforded greater renoprotection than administration of either drug alone. These results suggest that long-term control of hyperglycemia with luseogliflozin, especially in combination with lisinopril to lower blood pressure, attenuates the development of renal injury in this rat model of advanced diabetic nephropathy.
Collapse
|
66
|
Gillis EE, Williams JM, Garrett MR, Mooney JN, Sasser JM. The Dahl salt-sensitive rat is a spontaneous model of superimposed preeclampsia. Am J Physiol Regul Integr Comp Physiol 2015; 309:R62-70. [PMID: 25904684 DOI: 10.1152/ajpregu.00377.2014] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 04/09/2015] [Indexed: 12/24/2022]
Abstract
The mechanisms of the pathogenesis of preeclampsia, a leading cause of maternal morbidity and death worldwide, are poorly understood in part due to a lack of spontaneous animal models of the disease. We hypothesized that the Dahl salt-sensitive (S) rat, a genetic model of hypertension and kidney disease, is a spontaneous model of superimposed preeclampsia. The Dahl S was compared with the Sprague-Dawley (SD) rat, a strain with a well-characterized normal pregnancy, and the spontaneously hypertensive rat (SHR), a genetic model of hypertension that does not experience a preeclamptic phenotype despite preexisting hypertension. Mean arterial pressure (MAP, measured via telemetry) was elevated in the Dahl S and SHR before pregnancy, but hypertension was exacerbated during pregnancy only in Dahl S. In contrast, SD and SHR exhibited significant reductions in MAP consistent with normal pregnancy. Dahl S rats exhibited a severe increase in urinary protein excretion, glomerulomegaly, increased placental hypoxia, increased plasma soluble fms-like tyrosine kinase-1 (sFlt-1), and increased placental production of tumor necrosis factor-α (TNF-α). The Dahl S did not exhibit the expected decrease in uterine artery resistance during late pregnancy in contrast to the SD and SHR. Dahl S pups and litter sizes were smaller than in the SD. The Dahl S phenotype is consistent with many of the characteristics observed in human superimposed preeclampsia, and we propose that the Dahl S should be considered further as a spontaneous model to improve our understanding of the pathogenesis of superimposed preeclampsia and to identify and test new therapeutic targets for its treatment.
Collapse
|
67
|
Murphy S, Williams JM. Impaired Renal Autoregulation in Susceptible Models of Renal Disease. Curr Vasc Pharmacol 2014; 12:859-66. [DOI: 10.2174/15701611113116660148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/14/2013] [Accepted: 05/01/2013] [Indexed: 11/22/2022]
|
68
|
Williams JM, Duckworth CA, Burkitt MD, Watson AJM, Campbell BJ, Pritchard DM. Epithelial cell shedding and barrier function: a matter of life and death at the small intestinal villus tip. Vet Pathol 2014; 52:445-55. [PMID: 25428410 PMCID: PMC4441880 DOI: 10.1177/0300985814559404] [Citation(s) in RCA: 210] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The intestinal epithelium is a critical component of the gut barrier. Composed of a single layer of intestinal epithelial cells (IECs) held together by tight junctions, this delicate structure prevents the transfer of harmful microorganisms, antigens, and toxins from the gut lumen into the circulation. The equilibrium between the rate of apoptosis and shedding of senescent epithelial cells at the villus tip, and the generation of new cells in the crypt, is key to maintaining tissue homeostasis. However, in both localized and systemic inflammation, this balance may be disturbed as a result of pathological IEC shedding. Shedding of IECs from the epithelial monolayer may cause transient gaps or microerosions in the epithelial barrier, resulting in increased intestinal permeability. Although pathological IEC shedding has been observed in mouse models of inflammation and human intestinal conditions such as inflammatory bowel disease, understanding of the underlying mechanisms remains limited. This process may also be an important contributor to systemic and intestinal inflammatory diseases and gut barrier dysfunction in domestic animal species. This review aims to summarize current knowledge about intestinal epithelial cell shedding, its significance in gut barrier dysfunction and host-microbial interactions, and where research in this field is directed.
Collapse
|
69
|
Mallow PJ, Baniewicz J, Williams JM, Au-Yeung A. A Cost Comparison Analysis Of Medtronic's Stent Graft System To Competition For Endovascular Aneurysm Repair For Abdominal Aortic Aneurysms. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2014; 17:A482. [PMID: 27201409 DOI: 10.1016/j.jval.2014.08.1400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
|
70
|
Wang X, Johnson AC, Williams JM, White T, Chade AR, Zhang J, Liu R, Roman RJ, Lee JW, Kyle PB, Solberg-Woods L, Garrett MR. Nephron Deficiency and Predisposition to Renal Injury in a Novel One-Kidney Genetic Model. J Am Soc Nephrol 2014; 26:1634-46. [PMID: 25349207 DOI: 10.1681/asn.2014040328] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/08/2014] [Indexed: 11/03/2022] Open
Abstract
Some studies have reported up to 40% of patients born with a single kidney develop hypertension, proteinuria, and in some cases renal failure. The increased susceptibility to renal injury may be due, in part, to reduced nephron numbers. Notably, children who undergo nephrectomy or adults who serve as kidney donors exhibit little difference in renal function compared with persons who have two kidneys. However, the difference in risk between being born with a single kidney versus being born with two kidneys and then undergoing nephrectomy are unclear. Animal models used previously to investigate this question are not ideal because they require invasive methods to model congenital solitary kidney. In this study, we describe a new genetic animal model, the heterogeneous stock-derived model of unilateral renal agenesis (HSRA) rat, which demonstrates 50%-75% spontaneous incidence of a single kidney. The HSRA model is characterized by reduced nephron number (more than would be expected by loss of one kidney), early kidney/glomerular hypertrophy, and progressive renal injury, which culminates in reduced renal function. Long-term studies of temporal relationships among BP, renal hemodynamics, and renal function demonstrate that spontaneous single-kidney HSRA rats are more likely than uninephrectomized normal littermates to exhibit renal impairment because of the combination of reduced nephron numbers and prolonged exposure to renal compensatory mechanisms (i.e., hyperfiltration). Future studies with this novel animal model may provide additional insight into the genetic contributions to kidney development and agenesis and the factors influencing susceptibility to renal injury in individuals with congenital solitary kidney.
Collapse
|
71
|
Williams JM, Theobald PS, Jones MD. Infant cervical range of motion in the sagittal plane. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2014. [DOI: 10.12968/ijtr.2014.21.sup7.s6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background: Data pertaining to infant sagittal cervical range of motion (CROM) is lacking. Previous studies have either quantified motions other than sagittal or quantified sagittal range of motion in children >3 years old. Data capture in infants is complex and novel methods are required to overcome previous limitations. Such data is invaluable to inform paediatric injury models, such as those for shaken baby syndrome and automotive safety. Methods: Nine infants were recruited from a local group of parents (mean age=406 days, SD=19). Sagittal range-of-motion was measured using two miniature accelerometers (THETAmetrix), which provide orientation angle with respect to gravity. One sensor was placed on the forehead and one over the T2–3 spinous process. Sagittal range of motion was determined by subtracting the tilt angle of thorax sensor from that of the forehead and then summing the total sagittal movement cycle to yield resultant cervical range of motion. Infants were placed in their usual highchair and encouraged to move their head into flexion and extension by a parent focussing their attention on a favourite toy. At the point of maximal motion, the lead researcher applied gentle overpressure to ensure full range was achieved with parental consent. Once one full cycle of sagittal motion was achieved, data collection was terminated. Results: Overpressure was not possible in two infants, therefore, their data was omitted. The mean peak sagittal range of motion was 115° (SD=12) with a 95% CI=106–124°. Conclusions: The described methods were successful in measuring sagittal CROM in infants and could be used to determine range of motion in even younger infants. The data produced is in agreement with previous reports on older children; however, this method overcomes limitations of other data capture methods. Implications: The results provide the first estimate of infant CROM. These data can serve as reference for models of musculoskeletal and neurological injury, including those for shaken baby syndrome and automotive safety.
Collapse
|
72
|
Alqhtani RS, Williams JM, Jones MD, Theobald PS. Hip and lumbar motion: Is there a correlation between flexion and functional tasks? INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2014. [DOI: 10.12968/ijtr.2014.21.sup7.s7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
73
|
Alqhtani RS, Jones MD, Theobald PS, Williams JM. The reliability of novel multiregional spinal motion measurement device. INTERNATIONAL JOURNAL OF THERAPY AND REHABILITATION 2014. [DOI: 10.12968/ijtr.2014.21.sup7.s6a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background: Current spinal range of motion (ROM) measurement methods have limitations ranging from the amount of detail obtained to environmental costs and complexity. In particular, limited regional spinal motion is obtained using the current methods. However, a new portable ‘string’ of accelerometers is proposed to overcome these limitations. Objectives: This study seeks to determine the reliability of this sensor string in measuring three-dimensional spinal ROM and to investigate the relative motions across six different regions. Methods: Two procedures were undertaken on 18 healthy participants. Protocol one: two sensors were placed on the forehead and T1 to measure cervical ROM; and protocol two: six sensors were placed on the spinous processes of T1, T4, T8, T12, L3 and S1 to measure thoraco-lumbar regional ROM. Results: The ICC values for all regions were found to be high, ranging from ICC=0.88–0.99 for all movements and regions of the spine, demonstrating that the proposed methods were highly reliable for repeated measures. The standard error of the means (SEMs) were small, ranging from 0.7–5.2°. The flexion/extension motion demonstrated a mean SEM of 1.9° and 1.1° for lateral bending motions. Slightly larger SEMs were observed for rotation, especially for the upper thoracic (UT) and mid thoracic (MT) region with an overall mean SEM of 3.1°. Minimum detectable change (MDC) values ranged from 1.9–14.4°. The flexion/extension motion demonstrated a mean MDC of 5.2° with 3.1° for lateral bending motions. Slightly larger MDCs were observed for rotation (mean MDC=8.4°), especially for the UT and MT region. Implications: This method was able to quantify the relative contribution of differing regions to the overall motion. The method described represents a reliable method of assessing spinal ROM across multiple spinal regions.
Collapse
|
74
|
Westbrook L, Johnson AC, Regner KR, Williams JM, Mattson DL, Kyle PB, Henegar JR, Garrett MR. Genetic susceptibility and loss of Nr4a1 enhances macrophage-mediated renal injury in CKD. J Am Soc Nephrol 2014; 25:2499-510. [PMID: 24722447 DOI: 10.1681/asn.2013070786] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Nuclear hormone receptors of the NR4A subgroup have been implicated in cancer, atherosclerosis, and metabolic disease. However, little is known about the role of these receptors in kidney health or disease. Nr4a1-deficient rats (Nr4a1(-/-)) developed on a genetic background susceptible to kidney injury (fawn-hooded hypertensive rat [FHH]) were evaluated for BP, proteinuria, renal function, and metabolic parameters from 4 to 24 weeks-of-age. By week 24, Nr4a1(-/-) rats exhibited significantly higher proteinuria (approximately 4-fold) and decreased GFR compared with FHH controls. The severity of tubular atrophy, tubular casts, and interstitial fibrosis increased significantly in Nr4a1(-/-) rats and was accompanied by a large increase in immune cell infiltration, predominantly macrophages and to a lesser extent T cells and B cells. Global transcriptome and network analyses at weeks 8, 16, and 24 identified several proinflammatory genes and pathways differentially regulated between strains. Bone marrow crosstransplantation studies demonstrated that kidney injury in Nr4a1(-/-) rats was almost completely rescued by bone marrow transplanted from FHH controls. In vitro, macrophages isolated from Nr4a1(-/-) rats demonstrated increased immune activation compared with FHH-derived macrophages. In summary, the loss of Nr4a1 in immune cells appears to cause the increased kidney injury and reduced renal function observed in the Nr4a1(-/-) model.
Collapse
|
75
|
Fan F, Sun CW, Maier KG, Williams JM, Pabbidi MR, Didion SP, Falck JR, Zhuo J, Roman RJ. 20-Hydroxyeicosatetraenoic acid contributes to the inhibition of K+ channel activity and vasoconstrictor response to angiotensin II in rat renal microvessels. PLoS One 2013; 8:e82482. [PMID: 24324797 PMCID: PMC3853207 DOI: 10.1371/journal.pone.0082482] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/02/2013] [Indexed: 11/24/2022] Open
Abstract
The present study examined whether 20-hydroxyeicosatetraenoic acid (HETE) contributes to the vasoconstrictor effect of angiotensin II (ANG II) in renal microvessels by preventing activation of the large conductance Ca2+-activated K+ channel (KCa) in vascular smooth muscle (VSM) cells. ANG II increased the production of 20-HETE in rat renal microvessels. This response was attenuated by the 20-HETE synthesis inhibitors, 17-ODYA and HET0016, a phospholipase A2 inhibitor AACOF3, and the AT1 receptor blocker, Losartan, but not by the AT2 receptor blocker, PD123319. ANG II (10-11 to 10-6 M) dose-dependently decreased the diameter of renal microvessels by 41 ± 5%. This effect was blocked by 17-ODYA. ANG II (10-7 M) did not alter KCa channel activity recorded from cell-attached patches on renal VSM cells under control conditions. However, it did reduce the NPo of the KCa channel by 93.4 ± 3.1% after the channels were activated by increasing intracellular calcium levels with ionomycin. The inhibitory effect of ANG II on KCa channel activity in the presence of ionomycin was attenuated by 17-ODYA, AACOF3, and the phospholipase C (PLC) inhibitor U-73122. ANG II induced a peak followed by a steady-state increase in intracellular calcium concentration in renal VSM cells. 17-ODYA (10-5 M) had no effect on the peak response, but it blocked the steady-state increase. These results indicate that ANG II stimulates the formation of 20-HETE in rat renal microvessels via the AT1 receptor activation and that 20-HETE contributes to the vasoconstrictor response to ANG II by blocking activation of KCa channel and facilitating calcium entry.
Collapse
MESH Headings
- Angiotensin II/pharmacology
- Animals
- Calcium/metabolism
- Gene Expression
- Hydroxyeicosatetraenoic Acids/metabolism
- Ionomycin/pharmacology
- Male
- Microvessels/drug effects
- Microvessels/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phospholipases A2/metabolism
- Potassium Channel Blockers/pharmacology
- Potassium Channels/metabolism
- Potassium Channels, Calcium-Activated/antagonists & inhibitors
- Potassium Channels, Calcium-Activated/metabolism
- Rats
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Renal Circulation/drug effects
- Renal Circulation/physiology
- Type C Phospholipases/metabolism
- Vasoconstrictor Agents/pharmacology
Collapse
|