Hypertensive retinopathy in a transgenic angiotensin-based model

Severe hypertension destroys eyesight. The RAS (renin–angiotensin system) may contribute to this. This study relied on an established angiotensin, AngII (angiotensin II)-elevated dTGR (double-transgenic rat) model and same-background SD (Sprague–Dawley) rat controls. In dTGRs, plasma levels of AngII were increased. We determined the general retinal phenotype and observed degeneration of ganglion cells that we defined as vascular degeneration. We also inspected relevant gene expression and lastly observed alterations in the outer blood–retinal barrier. We found that both scotopic a-wave and b-wave as well as oscillatory potential amplitude were significantly decreased in dTGRs, compared with SD rat controls. However, the b/a-wave ratio remained unchanged. Fluorescence angiography of the peripheral retina indicated that exudates, or fluorescein leakage, from peripheral vessels were increased in dTGRs compared with controls. Immunohistological analysis of blood vessels in retina whole-mount preparations showed structural alterations in the retina of dTGRs. We then determined the general retinal phenotype. We observed the degeneration of ganglion cells, defined vascular degenerations and finally found differential expression of RAS-related genes and angiogenic genes. We found the expression of both human angiotensinogen and human renin in the hypertensive retina. Although the renin gene expression was not altered, the AngII levels in the retina were increased 4-fold in the dTGR retina compared with that in SD rats, a finding with mechanistic implications. We suggest that alterations in the outer blood–retinal barrier could foster an area of visual-related research based on our findings. Finally, we introduce the dTGR model of retinal disease.

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Pressure-natriuresis and -diuresis in transgenic rats harboring both human renin and human angiotensinogen genes.

Journal of the American Society of Nephrology ◽

10.1681/asn.v9122212 ◽

1998 ◽

Vol 9 (12) ◽

pp. 2212-2222

Author(s):

B Dehmel ◽

E Mervaala ◽

A Lippoldt ◽

V Gross ◽

J Bohlender ◽

...

Keyword(s):

Gene Expression ◽

Renin Angiotensin System ◽

Renal Perfusion ◽

Transgenic Rat ◽

Water Excretion ◽

Excretory Function ◽

Human Renin ◽

Renin Gene ◽

Renin Mrna ◽

Pressure Natriuresis

The hypertensive double transgenic rat harboring both the human renin and human angiotensinogen genes (dTGR) offers a unique opportunity to study the human renin-angiotensin system in an experimental animal model. Since nothing is known about the control of sodium and water excretion in these rats, this study was performed to compare pressure-natriuresis relationships in hypertensive dTGR and normotensive control rats harboring only the human renin gene (hREN), in order to determine how the pressure-natriuresis relationship is reset in hypertensive dTGR. To differentiate between extrinsic and intrinsic renal mechanisms, experiments were performed with and without renal denervation, and with and without infusions of vasopressin, norepinephrine, 17-OH-corticosterone, and aldosterone. Human and rat angiotensinogen and renin mRNA expression were also determined. In hREN without controlled renal function, urine flow and sodium excretion increased from 13 to 169 microl/min per g kidney wet weight (kwt) and from 1 to 30 micromol/min per g kwt, respectively, as renal perfusion pressure was increased from 67 to 135 mmHg. Renal blood flow (RBF) and GFR ranged between 3 to 7 and 0.9 to 1.5 ml/min per g kwt. In dTGR, pressure-natriuresis-diuresis relationships were shifted approximately 40 mmHg rightward. RBF was lower in dTGR than in hREN; GFR was not different. In dTGR with neurohormonal factors controlled, RBF was decreased and pressure-natriuresis-diuresis curves were not different compared to dTGR curves without these interventions. By light microscopy, the kidneys of these 6-wk-old dTGR and hREN rats were normal and indistinguishable. Both human and rat renin and angiotensinogen mRNA were expressed in the kidneys of dTGR. The two renin mRNA were decreased in dTGR, indicating a physiologic downregulation of renin gene expression by high BP. It is concluded that the renal pressure-natriuresis mechanism is reset toward higher pressure levels in dTGR and participates in the maintenance of hypertension. The reduced excretory function in dTGR depends on hREN and human angiotensinogen gene expression and is intrinsic to the kidney as opposed to extrarenal regulators.

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Ganglion cells apoptosis in diabetic rats as early prediction of glaucoma: a study of Brn3b gene expression and association with change of quantity of NO, caspase-3, NF-κB, and TNF-α

International Journal of Ophthalmology ◽

10.18240/ijo.2020.12.05 ◽

2020 ◽

Vol 13 (12) ◽

pp. 1872-1879

Author(s):

Irwan Tjandra ◽

Widya Artini ◽

Nurjati Chairani Siregar ◽

Andi Arus Victor

Keyword(s):

Gene Expression ◽

Caspase 3 ◽

Ganglion Cells ◽

Open Angle Glaucoma ◽

Rna Extraction ◽

Diabetic Rats ◽

Control Group ◽

Sprague Dawley ◽

Tnf Α

AIM: To find a new concept to show whether or not apoptosis of retinal ganglion cells (RGCs) can be determined in the histology of acute hyperglycemia in the role of expressed Brn3b gene related to nitric oxide (NO), caspase-3, nuclear factor kappa-B (NF-κB), and tumor necrosis factor-α (TNF-α) as an early predictor of primary open angle glaucoma (POAG) eyes and their associations. METHODS: Experimental in vivo study was carried out using adult male, white Sprague-Dawley rats aged ≥2mo, weighing 150-200 g. The animals were divided into two groups, one group receiving intraperitoneal injection of streptozotociz 50 mg/kg in 0.01 mol/L citric buffer and pH 4.5 and a comparison made with the control group. Retinal tissue was divided into two parts (both experimental and control groups respectively): a) right retina for immunohistochemistry (IHC; caspase-3 and TNF-α); b) left retina was divided into two parts for the purpose of real-time polymerase chain reaction (PCR) test (RNA extraction for Brn3b gene expression analysis) and ELISA test (NO and NF-κB). RESULTS: The experimental group showed a decrease in Brn3b gene expression compared to the control group (1.3-fold lower in 2nd month; 1.1-fold lower in 4th month and 2.5-fold lower in 6th month). However, there was a decrease of NO, caspase-3, and an increase of NF-κB and TNF-α quantity. CONCLUSION: The expression of mRNA Brn3b gene is inversely proportional to apoptosis in RGCs. The quantity of NO, caspase-3, NF-κB and TNF-α is influential in expression of Brn3b in RGCs caused by hyperglycemia in diabetic rats.

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Deleterious Effects of Hyperactivity of the Renin-Angiotensin System and Hypertension on the Course of Chemotherapy-Induced Heart Failure after Doxorubicin Administration: A Study in Ren-2 Transgenic Rat

International Journal of Molecular Sciences ◽

10.3390/ijms21249337 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9337

Author(s):

Petr Kala ◽

Hana Bartušková ◽

Jan Piťha ◽

Zdenka Vaňourková ◽

Soňa Kikerlová ◽

...

Keyword(s):

Heart Failure ◽

Systolic Function ◽

Treatment Strategies ◽

Renin Angiotensin System ◽

Transgenic Rat ◽

Suitable Model ◽

Sprague Dawley ◽

Renin Angiotensin ◽

New Treatment ◽

Novel Therapeutic Strategies

Doxorubicin’s (DOX) cardiotoxicity contributes to the development of chemotherapy-induced heart failure (HF) and new treatment strategies are in high demand. The aim of the present study was to characterize a DOX-induced model of HF in Ren-2 transgenic rats (TGR), those characterized by hypertension and hyperactivity of the renin-angiotensin-aldosterone system, and to compare the results with normotensive transgene-negative, Hannover Sprague-Dawley (HanSD) rats. DOX was administered for two weeks in a cumulative dose of 15 mg/kg. In HanSD rats DOX administration resulted in the development of an early phase of HF with the dominant symptom of bilateral cardiac atrophy demonstrable two weeks after the last DOX injection. In TGR, DOX caused substantial impairment of systolic function already at the end of the treatment, with further progression observed throughout the experiment. Additionally, two weeks after the termination of DOX treatment, TGR exhibited signs of HF characteristic for the transition stage between the compensated and decompensated phases of HF. In conclusion, we suggest that DOX-induced HF in TGR is a suitable model to study the pathophysiological aspects of chemotherapy-induced HF and to evaluate novel therapeutic strategies to combat this form of HF, which are urgently needed.

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Cell Atlas of the Human Fovea and Peripheral Retina

10.1101/2020.02.11.943779 ◽

2020 ◽

Cited By ~ 2

Author(s):

Wenjun Yan ◽

Yi-Rong Peng ◽

Tavé van Zyl ◽

Aviv Regev ◽

Karthik Shekhar ◽

...

Keyword(s):

Gene Expression ◽

Visual Processing ◽

Molecular Mechanisms ◽

Cynomolgus Macaque ◽

Retinal Disease ◽

Cell Types ◽

Macaque Monkey ◽

Peripheral Retina ◽

Retinal Ganglion ◽

Cell Class

ABSTRACTMost irreversible blindness results from retinal disease. To advance our understanding of the etiology of blinding diseases, we used single-cell RNA-sequencing (scRNA-seq) to analyze the transcriptomes of ∼85,000 cells from the fovea and peripheral retina of seven adult human donors. Utilizing computational methods, we identified 58 cell types within 6 classes: photoreceptor, horizontal, bipolar, amacrine, retinal ganglion and non-neuronal cells. Nearly all types are shared between the two retinal regions, but there are notable differences in gene expression and proportions between foveal and peripheral cohorts of shared types. We then used the human retinal atlas to map expression of 636 genes implicated as causes of or risk factors for blinding diseases. Many are expressed in striking cell class-, type-, or region-specific patterns. Finally, we compared gene expression signatures of cell types between human and the cynomolgus macaque monkey, Macaca fascicularis. We show that over 90% of human types correspond transcriptomically to those previously identified in macaque, and that expression of disease-related genes is largely conserved between the two species. These results validate the use of the macaque for modeling blinding disease, and provide a foundation for investigating molecular mechanisms underlying visual processing.

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Survival and remodeling of melanopsin cells during retinal dystrophy

Visual Neuroscience ◽

10.1017/s0952523808080309 ◽

2008 ◽

Vol 25 (2) ◽

pp. 125-138 ◽

Cited By ~ 29

Author(s):

ANTHONY A. VUGLER ◽

MA'AYAN SEMO ◽

ANNA JOSEPH ◽

GLEN JEFFERY

Keyword(s):

Retinal Degeneration ◽

Vascular Remodeling ◽

Ganglion Cells ◽

Retinal Dystrophy ◽

Retinal Disease ◽

Cell Number ◽

Molecular Profile ◽

Peripheral Retina ◽

Acetylated Tubulin ◽

Associated Proteins

AbstractThe melanopsin positive, intrinsically photosensitive retinal ganglion cells (ipRGCs) of the inner retina have been shown to send wide-ranging projections throughout the brain. To investigate the response of this important cell type during retinal dystrophy, we use the Royal College of Surgeons (RCS) dystrophic rat, a major model of retinal degeneration. We find that ipRGCs exhibit a distinctive molecular profile that remains unaltered during early stages of outer retinal pathology (15 weeks of age). In particular, these cells express βIII tubulin, α-acetylated tubulin, and microtubule-associated proteins (MAPs), while remaining negative for other RGC markers such as neurofilaments, calretinin, and parvalbumin. By 14 months of age, melanopsin positive fibers invade ectopic locations in the dystrophic retina and ipRGC axons/dendrites become distorted (a process that may involve vascular remodeling). The morphological abnormalities in melanopsin processes are associated with elevated immunoreactivity for MAP1b and a reduction in α-acetylated tubulin. Quantification of ipRGCs in whole mounts reveals reduced melanopsin cell number with increasing age. Focusing on the retinal periphery, we find a significant decline in melanopsin cell density contrasted by a stability of melanopsin positive processes. In addition to these findings, we describe for the first time, a distinct plexus of melanopsin processes in the far peripheral retina, a structure that is coincident with a short wavelength opsin cone-enriched rim. We conclude that some ipRGCs are lost in RCS dystrophic rats as the disease progresses and that this loss may involve vascular remodeling. However, a significant number of melanopsin positive cells survive into advanced stages of retinal degeneration and show indications of remodeling in response to pathology. Our findings underline the importance of early intervention in human retinal disease in order to preserve integrity of the inner retinal photoreceptive network.

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Local mechanisms for acupoint sensitization in gall bladder meridian of foot shaoyang-a gene chip study

Acupuncture & Electro-Therapeutics Research ◽

10.3727/036012919x15650315071898 ◽

2019 ◽

Vol 44 (2) ◽

pp. 77-87

Author(s):

Koichi Ishida ◽

Liyue Qin ◽

Ting Wang ◽

Ying Lei ◽

Weiwei Hu ◽

...

Keyword(s):

Gene Expression ◽

Gall Bladder ◽

Interleukin 1 ◽

Gene Chip ◽

Molecular Evidence ◽

Sprague Dawley ◽

Sprague Dawley Rats ◽

Bladder Meridian ◽

Integrin Linked Kinase ◽

Necrosis Factor

Acupuncture manipulations are clinically important to traditional Chinese medicine, yet the biological mechanisms have not been fully understood. This study aimed to investigate continuous stimulation-induced gene expression changes at stimulated and non-stimulated adjacent acupoints in the same meridian. Catgut embedding into acupoint (CEP) was conducted at acupoint Yanglingquan (gall bladder meridian of foot-shaoyang 34, GB34) of Sprague Dawley rats once or continuously for eight weeks, and gene expression changes at GB34 were assessed by gene chip array analysis 72 h after the last CEP treatment. A total of 688 genes exhibited opposite changes in expression between the two treatments, and 1,336 genes were regulated only by the eight-week CEP treatment. Ingenuity Pathway Analysis revealed that among these differentially regulated genes by one-time and eight-week CEP treatment, insulin-like growth factor-1 pathway and integrin-linked kinase pathway, and Wnt/~ catenin signaling pathway match the observed gene changes to predicted up/down regulation patterns. Upstream analysis further predicted six molecules, namely, tumor necrosis factor, interleukin 1~, interleukin la, kallikrein-related peptidase 5, protein kinase Ca, and catenin ~1. On the other hand, continuous eight-week CEP stimulation at acupoint Xuanzhong (GB39) caused similar changes in the expression of 32 genes at acupoints GB34 and Fengshi (GB31) on the same meridian. Taken together, our results provide the first molecular evidence for the local acupoints' mechanisms for acupoint sensitization theory, and implicate the existence of signaling pathways, either direct or indirect, between acupoints within the meridian GB.

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Anti-Diabetic and Angio-Protective Effect of Guluronic Acid (G2013) as a New Nonsteroidal Anti-Inflammatory Drug in the Experimental Model of Diabetes

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530319666191016103918 ◽

2020 ◽

Vol 20 (3) ◽

pp. 446-452

Author(s):

Seyed S. Mortazavi-Jahromi ◽

Shahab Alizadeh ◽

Mohammad H. Javanbakht ◽

Abbas Mirshafiey

Keyword(s):

Gene Expression ◽

Blood Glucose ◽

Food Intake ◽

Experimental Model ◽

Serum Insulin ◽

Fasting Blood Glucose ◽

Diabetic Control ◽

The Body ◽

Sprague Dawley ◽

Guluronic Acid

Background: This study aimed to investigate the effects of guluronic acid (G2013) on blood sugar, insulin, and gene expression profile of oxLDL receptors (SR-A, CD36, LOX-1, and CD68) in the experimental model of diabetes. Methods: 18 Sprague Dawley rats were randomly assigned to three groups of healthy control, diabetic control, and G2013 group. Diabetes was induced through intraperitoneal (IP) injection of 60 mg/kg streptozotocin. The subjects were IP treated with 25 mg/kg of G2013 per day for 28 days. The body weight, food intake, fasting blood glucose and insulin were measured. In addition, the expression of mentioned genes was investigated through quantitative real-time PCR. Results: The data showed that the final weight increased significantly in the G2013-treated subjects compared to the diabetic control (p < 0.05). The results indicated that final food intake significantly reduced in the G2013-treated subjects compared to the diabetic control (p < 0.05). The study findings also suggested that the final fasting blood glucose significantly reduced in the G2013-treated group, whereas the final fasting serum insulin level significantly increased in this group compared to the diabetic control (p < 0.05). Moreover, the gene expression levels of SR-A, CD36, LOX-1, and CD68 in the G2013 group significantly reduced compared to the diabetic control (p < 0.05). Conclusion: This study showed that G2013, could reduce blood glucose and increase insulin levels and reduce the gene expression level of oxLDL receptors. In addition, it may probably play an important role in reducing the severity of diabetes-induced inflammatory symptoms.

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