scholarly journals A dose-escalating toxicology study of the candidate biologic ELP-VEGF

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jamarius P. Waller ◽  
Stephen P. Burke ◽  
Jason Engel ◽  
Alejandro R. Chade ◽  
Gene L. Bidwell
Keyword(s):  
Growth Rate ◽  
Renal Fibrosis ◽  
Renal Diseases ◽  
Tumor Growth Rate ◽  
Vascular Density ◽  
Tumor Vascularity ◽  
Sd Rats ◽  
Renal Vascular ◽  
Dose Dependent ◽  
Dose Escalating

AbstractVascular Endothelial Growth Factor (VEGF), a key mediator of angiogenesis and vascular repair, is reduced in chronic ischemic renal diseases, leading to microvascular rarefaction and deterioration of renal function. We developed a chimeric fusion of human VEGF-A121 with the carrier protein Elastin-like Polypeptide (ELP-VEGF) to induce therapeutic angiogenesis via targeted renal VEGF therapy. We previously showed that ELP-VEGF improves renal vascular density, renal fibrosis, and renal function in swine models of chronic renal diseases. However, VEGF is a potent cytokine that induces angiogenesis and increases vascular permeability, which could cause undesired off-target effects or be deleterious in a patient with a solid tumor. Therefore, the current study aims to define the toxicological profile of ELP-VEGF and assess its risk for exacerbating tumor progression and vascularity using rodent models. A dose escalating toxicology assessment of ELP-VEGF was performed by administering a bolus intravenous injection at doses ranging from 0.1 to 200 mg/kg in Sprague Dawley (SD) rats. Blood pressure, body weight, and glomerular filtration rate (GFR) were quantified longitudinally, and terminal blood sampling and renal vascular density measurements were made 14 days after treatment. Additionally, the effects of a single administration of ELP-VEGF (0.1–10 mg/kg) on tumor growth rate, mass, and vascular density were examined in a mouse model of breast cancer. At doses up to 200 mg/kg, ELP-VEGF had no effect on body weight, caused no changes in plasma or urinary markers of renal injury, and did not induce renal fibrosis or other histopathological findings in SD rats. At the highest doses (100–200 mg/kg), ELP-VEGF caused an acute, transient hypotension (30 min), increased GFR, and reduced renal microvascular density 14 days after injection. In a mouse tumor model, ELP-VEGF did not affect tumor growth rate or tumor mass, but analysis of tumor vascular density by micro-computed tomography (μCT) revealed significant, dose dependent increases in tumor vascularity after ELP-VEGF administration. ELP-VEGF did not induce toxicity in the therapeutic dosing range, and doses one hundred times higher than the expected maximum therapeutic dose were needed to observe any adverse signs in rats. In breast tumor—bearing mice, ELP-VEGF therapy induced a dose-dependent increase in tumor vascularity, demanding caution for potential use in a patient suffering from kidney disease but with known or suspected malignancy.

P0117DOSE ESCALATING TOXICOLOGY STUDY OF ELP-VEGF, A NOVEL BIOLOGIC FOR RENAL THERAPEUTIC ANGIOGENESIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Gene Bidwell ◽  
Jamarius Waller ◽  
Jason Engel ◽  
Alejandro Chade
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Body Weight ◽  
Therapeutic Dose ◽  
Therapeutic Angiogenesis ◽  
Female Rats ◽  
Vascular Density ◽  
Therapeutic Doses ◽  
Renal Vascular ◽  
Dose Escalating

Abstract Background and Aims Chronic renal disease, irrespective of the etiology, is hallmarked by renal microvascular rarefaction. This rarefaction is associated with a reduced bioavailability of the pro-angiogenic cytokine vascular endothelial growth factor (VEGF). Recently, we developed a therapeutic intervention for ischemic renal conditions using therapeutic angiogenesis – supplementing renal VEGF levels. This was achieved by administration of a biopolymer-stabilized form of VEGF using a fusion protein between human VEGF-A121 and an elastin-like polypeptide carrier protein (ELP-VEGF). ELP-VEGF induced microvascular remodeling and increased microvascular density when administered intra-renally in swine models of unilateral renovascular disease (RVD) and chronic kidney disease (CKD), which was associated with improved renal function, reduced renal inflammation, and reduced renal fibrosis. Also, ELP-VEGF targeted the kidney when administered systemically and induced similar beneficial effects on renal function and renal vascular density. The therapeutic dose of ELP-VEGF in the swine models was 0.1 mg/kg when administered intra-renally and 1.0 mg/kg when administered intravenously. The aims of the present study were to determine the maximum tolerated dose of ELP-VEGF and assess its dose-related toxicity. We hypothesize that ELP-VEGF will not exhibit toxicity at therapeutic doses. Method A dose escalating toxicology experiment was performed in Sprague Dawley. Female rats were instrumented with either carotid catheters or carotid artery telemeters for blood pressure monitoring. After a recovery period, a baseline 24-hour urine sample was collected, and baseline glomerular filtration rate (GFR) was measured by monitoring FITC-sinistrin clearance via transdermal fluorescence. A single injection of saline control or ELP-VEGF (0.1, 1, 10, 100, or 200 mg/kg) was administered, and blood pressure was monitored by telemetry or by direct carotid arterial pressure measurements. Body weights were monitored daily throughout the study, and 24-hour urine collections and GFR measurements were repeated 7 and 14 days after protein injection. On day 14 after injection, blood was collected, one kidney was collected and fixed for histological examination, and the second kidney was perfused with Microfil vascular contrast agent for quantification of renal vascular density by micro-CT. Results ELP-VEGF caused no significant changes in body weight at any dose. At the highest doses there was an acute drop in blood pressure (20 – 30 mm Hg at 100 and 200 mg/kg dose, respectively) for approximately twenty minutes post-injection which then normalized. GFR was unchanged by ELP-VEGF at doses up to 100 mg/kg. However, GFR was significantly increased 14 days after treatment with 200 mg/kg ELP-VEGF (1.5 +/- 0.3 versus 2.7 +/- 0.3 mL/min/100 g body weight, p=0.0021). Plasma toxicology revealed no changes in markers of liver or kidney toxicity (AST, ALT, BUN, creatinine, LDH, bilirubin) at any dose or time point. Renal vascular density was unaffected by ELP-VEGF at doses up to 10 mg/kg. However, at 200 mg/kg ELP-VEGF, renal vascular density was significantly decreased for small (0 – 100 micron, p=0.0007) and intermediate (100 – 200 micron, p=0.028) sized vessels Conclusion ELP-VEGF has a proven therapeutic potential for treatment of RVD and CKD at therapeutic doses ranging from 0.1 – 1.0 mg/kg in swine models. Dose escalating toxicity assessment in rats found no effect of ELP-VEGF on body weight, blood pressure, plasma markers of liver and renal toxicity, GFR, or renal vascular density at these therapeutic doses. ELP-VEGF doses of 100 – 200 mg/kg caused transient hypotension immediately after the injection and were associated with increased GFR and loss of renal vascular density, possibly indicating renal damage at ultra-high doses. We conclude that the therapeutic window for ELP-VEGF is 100 – 1,000 times the effective therapeutic dose.

Changes in growth rate and thyroid- and sex-hormones blood levels in rats under sub-chronic lithium treatment

2006 ◽  
Vol 25 (5) ◽  
pp. 243-250 ◽  
Author(s):  
M S Allagui ◽  
N Hfaiedh ◽  
C Vincent ◽  
F Guermazi ◽  
J-C Murat ◽  
...  
Keyword(s):  
Growth Rate ◽  
Lithium Treatment ◽  
Lithium Carbonate ◽  
Serum Levels ◽  
Antagonistic Effect ◽  
Blood Levels ◽  
Vaginal Mucosa ◽  
Dependent Manner ◽  
Serum Concentrations ◽  
Dose Dependent

Lithium therapy, mainly used in curing some psychiatric diseases, is responsible for numerous undesirable side effects. The present study is a contribution to the understanding of the pathophysiological mechanisms underlying lithium toxicity. Male and female mature rats were divided into three batches and fed commercial pellets: one batch was the control and the second and third batches were given 2 g (Li1) and 4 g (Li2) of lithium carbonate/kg of food/day, respectively. After 7, 14, 21 and 28 days, serum levels of free tri-iodothyronine (FT3), thyroxine (FT4), testosterone and estradiol were measured. Attention was also paid to growth rate and a histological examination of testes or vaginal mucosa was carried out. In treated rats, a dose-dependent loss of appetite and a decrease in growth rate were observed, together with symptoms of polydypsia, polyuria and diarrhea. Lithium serum concentrations increased from 0.44 mM (day 7) to 1.34 mM (day 28) in Li1 rats and from 0.66 to 1.45 mM (day 14) in Li2 rats. Li2 treatment induced a high mortality after 14 days, reaching 50-60% in female and male animals. From these data, the LD50 (14 days Li2 chronic treatment) was calculated to be about 0.3 g/day per kilogram of animal, leading to Li serum concentrations of about 1.4 mM. A significant decrease of FT3 and FT4 was observed in treated rats. This effect appeared immediately for the highest dose and was more pronounced for FT3, resulting in an increase of the FT4/FT3 ratio. In males, testosterone decreased and spermatogenesis was stopped. Conversely, in females, estradiol increased in a dose-dependent manner as the animals were blocked in the diestrus phase at day 28. This finding supports a possible antagonistic effect of lithium on the estradiol receptors.

scholarly journals Tumor growth characteristics of the Walker 256 AR tumor, a regressive variant of the rat Walker 256 A tumor

2010 ◽  
Vol 53 (5) ◽  
pp. 1101-1108 ◽  
Author(s):  
Fernando Guimarães ◽  
Alessandra Soares Schanoski ◽  
Tereza Cristina Samico Cavalcanti ◽  
Priscila Bianchi Juliano ◽  
Ana Neuza Viera-Matos ◽  
...  
Keyword(s):  
Growth Rate ◽  
Tumor Growth ◽  
Wistar Rats ◽  
Tumor Regression ◽  
Growth Characteristics ◽  
Tumor Growth Rate ◽  
Continuous Growth ◽  
Tumor Bearing ◽  
Walker 256 ◽  
Complete Tumor

The present study aimed at characterizing the subcutaneous development of the Walker 256 (W256) AR tumor, a regressive variant of the rat W256 A tumor. Wistar rats were injected subcutaneously with 4x10(6) W256 A or W256 AR tumor cells. The development of tumors was evaluated daily by percutaneous measurements. None of the W256 A tumors (n=20) regressed, but 62% of the W256 AR tumor-bearing rats (n=21) underwent complete tumor regression within 35 days. Continuous growth of AR tumors was characterized by an increase of the tumor growth rate from day 12, which reached values above 1.0 g/day, and were significantly higher (p<0.05) than those of the regressive AR tumors. Immunosuppression by irradiation before subcutaneous injection of AR cells completely abrogated tumor regression and was associated with severe metastatic dissemination. Daily evaluation of the tumor growth rate enabled the discrimination, in advance, between continuously growing tumors and those that regressed later on.

Targeted Treatment of Experimental Spinal Cord Glioma With Dual Gene-Engineered Human Neural Stem Cells

Neurosurgery ◽  
2015 ◽  
Vol 79 (3) ◽  
pp. 481-491 ◽  
Author(s):  
Alexander E. Ropper ◽  
Xiang Zeng ◽  
Hariprakash Haragopal ◽  
Jamie E. Anderson ◽  
Zaid Aljuboori ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Growth Rate ◽  
Neural Stem Cells ◽  
Tumor Growth ◽  
Rat Model ◽  
Weight Bearing ◽  
Tumor Growth Rate ◽  
Intramedullary Spinal Cord ◽  
Human Neural Stem Cells

Abstract BACKGROUND There are currently no satisfactory treatments or experimental models showing autonomic dysfunction for intramedullary spinal cord gliomas (ISCG). OBJECTIVE To develop a rat model of ISCG and investigate whether genetically engineered human neural stem cells (F3.hNSCs) could be developed into effective therapies for ISCG. METHODS Immunodeficient/Rowett Nude rats received C6 implantation of G55 human glioblastoma cells (10K/each). F3.hNSCs engineered to express either cytosine deaminase gene only (i.e., F3.CD) or dual genes of CD and thymidine kinase (i.e., F3.CD-TK) converted benign 5-fluorocytosine and ganciclovir into oncolytic 5-fluorouracil and ganciclovir-triphosphate, respectively. ISCG rats received injection of F3.CD-TK, F3.CD, or F3.CD-TK debris near the tumor epicenter 7 days after G55 seeding, followed with 5-FC (500 mg/kg/5 mL) and ganciclovir administrations (25 mg/kg/1 mL/day × 5/each repeat, intraperitoneal injection). Per humane standards for animals, loss of weight-bearing stepping in the hindlimb was used to determine post-tumor survival. Also evaluated were autonomic functions and tumor growth rate in vivo. RESULTS ISCG rats with F3.CD-TK treatment survived significantly longer (37.5 ± 4.78 days) than those receiving F3.CD (21.5 ± 1.75 days) or F3.CD-TK debris (19.3 ± 0.85 days; n = 4/group; P &lt;.05, median rank test), with significantly improved autonomic function and reduced tumor growth rate. F3.DC-TK cells migrated diffusively into ISCG clusters to mediate oncolytic effect. CONCLUSION Dual gene-engineered human neural stem cell regimen markedly prolonged survival in a rat model that emulates somatomotor and autonomic dysfunctions of human cervical ISCG. F3.CD-TK may provide a novel approach to treating clinical ISCG.

scholarly journals Effects of Preventive Acupuncture and Moxibustion on Fat Accumulation, Blood Lipid, and UterusE2of Menopause Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shi-Peng Zhu ◽  
Yu-wei He ◽  
Huan Chen ◽  
Zhi-Fang Sun ◽  
Na Ding ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Density Lipoprotein ◽  
Blood Lipid ◽  
Control Group ◽  
Young Control ◽  
Fat Accumulation ◽  
Acupuncture And Moxibustion ◽  
Weight Growth ◽  
Sd Rats

Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats.Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n=10/group) and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4). Body weight growth rate has been recorded. Plasma total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high density lipoprotein (HDL) levels and uterusE2level were measured.Results. Compared to young control group, plasma TC and LDL increased and uterusE2reduced significantly in 12-month-old control group. Compared to 12-month-old control group, plasma TC and LDL level and body weight growth rate decreased while HDL level increased remarkably in preventive acupuncture 12-month-old group. Compared to 14-month-old control group, plasma TC level and body weight growth rate decreased remarkably in preventive moxibustion 14-month-old group.Conclusions. Preventive acupuncture and moxibustion can significantly decrease the plasma TG and LDL, increase the plasma HDL, and prevent fat accumulation. Our finding suggests that preventive acupuncture and moxibustion have beneficial effects on blood lipid. Different treatment effects were found between preventive acupuncture and preventive moxibustion.

Obstructive nephropathy and renal fibrosis

2002 ◽  
Vol 283 (5) ◽  
pp. F861-F875 ◽  
Author(s):  
Saulo Klahr ◽  
Jeremiah Morrissey
Keyword(s):  
Renal Disease ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Rodent Model ◽  
Renal Diseases ◽  
Obstructive Nephropathy ◽  
Therapeutic Approaches ◽  
Cellular Events ◽  
The Impact ◽  
Made In

Interstitial fibrosis has a major role in the progression of renal diseases. Several animal models are available for the study of renal fibrosis. The models of aminonucleoside-induced nephrotic syndrome, cyclosporin nephrotoxicity, and passive Heyman nephritis are characterized by molecular and cellular events similar to those that occur in obstructive nephropathy. Additionally, inhibition of angiotensin-converting enzyme exerts salutary effects on the progression of renal fibrosis in obstructive nephropathy. Unilateral ureteral obstruction (UUO) has emerged as an important model for the study of the mechanisms of renal fibrosis and also for the evaluation of the impact of potential therapeutic approaches to ameliorate renal disease. Many quantifiable pathophysiological events occur over the span of 1 wk of UUO, making this an attractive model for study. This paper reviews some of the ongoing studies that utilized a rodent model of UUO. Some of the findings of the animal model have been compared with observations made in patients with obstructive nephropathy. Most of the evidence suggests that the rodent model of UUO is reflective of human renal disease processes.

scholarly journals Tumor Growth Rate Determines the Timing of Optimal Chronomodulated Treatment Schedules

2010 ◽  
Vol 6 (3) ◽  
pp. e1000712 ◽  
Author(s):  
Samuel Bernard ◽  
Branka Čajavec Bernard ◽  
Francis Lévi ◽  
Hanspeter Herzel
Keyword(s):  
Growth Rate ◽  
Tumor Growth ◽  
Tumor Growth Rate

Carvacrol Ameliorates Transforming Growth Factor-β1-Induced Extracellular Matrix Deposition and Reduces Epithelial-Mesenchymal Transition by Regulating The Phosphatidylinositol 3-Kinase/Protein Kinase B Pathway In Hk-2 Cells

2021 ◽  
Vol 19 (4) ◽  
pp. 501-507
Author(s):  
Yunhe Gu ◽  
Peiyao Guo ◽  
Guangbiao Xu
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Transforming Growth Factor Β1 ◽  
Mesenchymal Transition ◽  
Matrix Deposition ◽  
Extracellular Matrix Deposition ◽  
Dose Dependent

Transforming growth factor-β1 promotes excessive extracellular matrix deposition and epithelial-mesenchymal transition of tubular epithelial cells, thus stimulating the progression of renal fibrosis. Carvacrol has been shown to alleviate cardiac and liver fibrosis and attenuate renal injury. However, the role of carvacrol on renal fibrosis has not been examined. First, measurements using Cell Counting Kit-8 showed that carvacrol reduced cell viability of tubular epithelial cell line HK-2 in a dose-dependent fashion. Second, transforming growth factor-β1 induced excessive extracellular matrix deposition in HK-2 cells with enhanced collagen I, collagen IV, and fibronectin expression. However, carvacrol decreased the expression of collagen I, collagen IV in a dose-dependent manner and fibronectin to attenuate the extracellular matrix deposition in HK-2. Third, carvacrol attenuated TGF-β1-induced decrease of E-cadherin and increase of snail, vimentin, and alpha-smooth muscle actin in HK-2 cells. Transforming growth factor-β1-induced increase in PI3K and AKT phosphorylation in HK-2 were also reversed by carvacrol. Collectively, carvacrol ameliorates renal fibrosis through inhibition of transforming growth factor-β1-induced extracellular matrix deposition and epithelial-mesenchymal transition of HK-2 cells, providing potential therapy for the treatment of renal fibrosis.

Sign in / Sign up

Export Citation Format

Share Document