scholarly journals Chronic Microcystin-LR Exposure Induces Hepatocarcinogenesis via Increased Gankyrin in Vitro and in Vivo

2018 ◽  
Vol 49 (4) ◽  
pp. 1420-1430 ◽  
Author(s):  
Lixiong He ◽  
Yujing Huang ◽  
Qiaonan Guo ◽  
Hui Zeng ◽  
Chuanfen Zheng ◽  
...  
Keyword(s):  
Low Dose ◽  
Soft Agar ◽  
Tumor Formation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
L02 Cells ◽  
Insight Into

Background/Aims: Our recent study indicated that the serum microcystin-LR (MC-LR) level is positively linked to the risk of human hepatocellular carcinoma (HCC). Gankyrin is over-expressed in cancers and mediates oncogenesis; however, whether MC-LR induces tumor formation and the role of gankyrin in this process is unclear. Methods: We induced malignant transformation of L02 liver cells via 35 passages with exposure to 1, 10, or 100 nM MC-LR. Wound healing, plate and soft agar colony counts, and nude mice tumor formation were used to evaluate the tumorigenic phenotype of MC-LR-treated cells. Silencing gankyrin was used to confirm its function. We established a 35-week MC-LR exposure rat model by twice weekly intraperitoneal injection with 10 μg/kg body weight. In addition, 96 HCC patients were tested for tumor tissue gankyrin expression and serum MC-LR levels. Results: Chronic low-dose MC-LR exposure increased proliferation, mobility, clone and tumor formation abilities of L02 cells as a result of gankyrin activation, while silencing gankyrin inhibited the carcinogenic phenotype of MC-LR-treated cells. MC-LR also induced neoplastic liver lesions in Sprague-Dawley rats due to up-regulated gankyrin. Furthermore, a trend of increased gankyrin was observed in humans exposed to MC-LR. Conclusion: These results suggest that MC-LR induces hepatocarcinogenesis in vitro and in vivo by increasing gankyrin levels, providing new insight into MC-LR carcinogenicity studies.

scholarly journals Role of RFRP-3 in the development of cold stress-induced polycystic ovary phenotype in rats

2018 ◽  
Vol 239 (1) ◽  
pp. 81-91 ◽  
Author(s):  
V Squicciarini ◽  
R Riquelme ◽  
K Wilsterman ◽  
G E Bentley ◽  
H E Lara
Keyword(s):  
Cold Stress ◽  
Polycystic Ovary ◽  
Follicular Development ◽  
Sprague Dawley ◽  
Ovarian Steroid ◽  
Sprague Dawley Rats ◽  
Mrna Expression Analysis

RFamide-related peptide (RFRP-3) is a regulator of GnRH secretion from the brain, but it can also act in human ovary to influence steroidogenesis. We aimed to study the putative local role of RFRP-3 in the ovary and its potential participation in the development of a polycystic ovary phenotype induced by chronic sympathetic stress (cold stress). We used adult Sprague–Dawley rats divided into control and stressed groups. In both groups, we studied the effect of intraovarian exposure to RFRP-3 on follicular development and plasma ovarian steroid concentrations. We also tested the effect of RFRP-3 on ovarian steroid production in vitro. Chronic in vivo intraovarian exposure to RFRP-3 decreased basal testosterone concentrations and cold stress-induced progesterone production by the ovary. In vitro, RFRP-3 decreased hCG-induced ovarian progesterone and testosterone secretion. Immunohistochemistry and mRNA expression analysis showed a decrease in Rfrp and expression of its receptor in the ovary of stressed rats, a result which is in line with the increased testosterone levels found in stressed rats. In vivo application of RFRP-3 recovered the low levels of secondary and healthy antral follicles found in stressed rats. Taken together, our data indicate a previously unknown response of hypothalamic and ovarian RFRP-3 to chronic cold stress, influencing ovarian steroidogenesis and follicular dynamics. Thus, it is likely that RFRP-3 modulation in the ovary is a key component of development of the polycystic ovary phenotype.

Metalloendopeptidases EC 3.4.24.15/16 regulate bradykinin activity in the cerebral microvasculature

2003 ◽  
Vol 284 (6) ◽  
pp. H1942-H1948 ◽  
Author(s):  
M. Ursula Norman ◽  
Rebecca A. Lew ◽  
A. Ian Smith ◽  
Michael J. Hickey
Keyword(s):  
Specific Inhibitor ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Cerebral Microvasculature ◽  
Microvessel Permeability ◽  
The Brain ◽  
Cerebral Microvessel

Bradykinin is a vasoactive peptide that has been shown to increase the permeability of the cerebral microvasculature to blood-borne macromolecules. The two zinc metalloendopeptidases EC 3.4.24.15 (EP 24.15) and EC 3.4.24.16 (EP 24.16) degrade bradykinin in vitro and are highly expressed in the brain. However, the role that these enzymes play in bradykinin metabolism in vivo remains unclear. In the present study, we investigated the role of EP 24.15 and EP 24.16 in the regulation of bradykinin-induced alterations in microvascular permeability. Permeability of the cerebral microvasculature was assessed in anesthetized Sprague-Dawley rats by measuring the clearance of 70-kDa FITC dextran from the brain. Inhibition of EP 24.15 and EP 24.16 by the specific inhibitor N-[1-( R, S)-carboxy-3-phenylpropyl]-Ala-Aib-Tyr- p-aminobenzoate (JA-2) resulted in the potentiation of bradykinin-induced increases in cerebral microvessel permeability. The level of potentiation was comparable to that achieved by the inhibition of angiotensin-converting enzyme. These findings provide the first evidence of an in vivo role for EP 24.15/EP 24.16 in brain function, specifically in regulating alterations in microvessel permeability induced by exogenous bradykinin.

Cytochrome C suppresses renal accumulation and nephrotoxicity of polymyxin B

2018 ◽  
Vol 38 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Z-D Li ◽  
J Luo ◽  
L-H Jia ◽  
X-Y Wang ◽  
Z-K Xun ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Polymyxin B ◽  
Control Group ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
C 30 ◽  
C 50

The receptor megalin plays an important role in the accumulation of polymyxin B (PMB) in renal cells in vitro. This study aimed to examine the effects of cytochrome c (cyto c), a typical megalin ligand, on renal accumulation and nephrotoxicity of PMB in vivo. Thirty Sprague-Dawley rats were randomly divided into the vehicle control group, PMB group, PMB + cyto c 50, 100, or 200 mg/kg group, respectively, and were treated with intravenous cyto c 30 min before the administration of PMB 4.0 mg/kg once a day for consecutive 5 days. On the 4th day after administration, 24 h urine was collected to determine N-acetyl-β-D-glucosaminidase excretion. Six hours after the last injection on the 5th day, kidneys were harvested to assay PMB concentration and observe pathological alterations, and blood samples were collected to assay serum creatinine (SCr), blood urea nitrogen (BUN), and blood β2-microglobulin (β2-MG) levels. Cyto c 50, 100, and 200 mg/kg decreased the accumulation of PMB in the kidney by 18.5%, 39.1% ( p < 0.01), and 36.8% ( p < 0.01), respectively, and reduced 24 h N-acetyl-β-D- glucosaminidase excretion by 22.5% ( p < 0.05), 40.4% ( p < 0.01), and 40.4% ( p < 0.01), respectively. Kidney pathological damage induced by PMB was markedly reduced by cyto c 100 mg/kg and 200 mg/kg. However, there were no significant differences in SCr, BUN, and blood β2-MG levels among the groups. These results indicated that cyto c may inhibit the renal accumulation and nephrotoxicity of PMB in a rat model, further proving the role of megalin in the accumulation of PMB.

scholarly journals Upregulation of SIRT1 and FOXO3a Contributes to The Protective Role of Estrogen on HPH in Rats

2020 ◽  
Author(s):  
Li Wang ◽  
Yadong Yuan ◽  
Xiaowei Gong ◽  
Jianjun Mao
Keyword(s):  
Pulmonary Artery ◽  
Protective Role ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Pulmonary Vascular Remodeling ◽  
Sprague Dawley Rats ◽  
Sirt1 Activator

Abstract Background: SIRT1 has anti-proliferation effects on cells through regulating the expression and activity of FOXOs. Estrogen (E2) has protective effects against hypoxic pulmonary hypertension (HPH), but the involvement of SIRT1 and FOXOs in the proliferation of pulmonary artery smooth muscle cells (PASMCs) and contribution to the effects of E2 on HPH are poorly understood. To use E2 to explore the roles of SIRT1 and FOXO3a in the pathogenesis and progression of HPH and pulmonary vascular remodeling (PVR) in vivo and in vitro.Methods: Female Sprague-Dawley rats with bilateral ovariectomy were randomized to normoxia, normoxia+E2, hypoxia, and hypoxia+E2. Serum E2 levels, hemodynamic, and pulmonary vascular pathomorphology were assessed. The anti-proliferation effect of E2 was determined in human PASMCs under hypoxia/normoxia. Immunohistochemistry, western blotting, and real-time PCR were used to assess SIRT1, FOXO3a, and PCNA in rat pulmonary artery and hPASMCs. SIRT1 activity was assayed.Results: Hypoxia increased mean pulmonary artery pressure (mPAP), medial width of pulmonary arterioles, right ventricular hypertrophy index (RVHI), decreased expression SIRT1 and FOXO3a and increased PCNA expression in rats; E2 alleviated these changes. In vitro, E2 significantly inhibited hypoxia-induced hPASMCs proliferation, associated with improvements in SIRT1 and FOXO3a expression, consistent with the in vivo results. SIRT1 inhibition attenuated the effects of E2 on hPASMCs proliferation and the expression of FOXO3a. A SIRT1 activator mimicked the effects of E2 on hPASMCs proliferation and the expression of FOXO3a.Conclusions: Upregulation of SIRT1 and FOXO3a contributes to the protective role of estrogen on HPH in rats, as supported by in vitro results using hPASMCs.

scholarly journals Endothelin contributes to blunted renal autoregulation observed with a high-salt diet

2015 ◽  
Vol 309 (8) ◽  
pp. F687-F696 ◽  
Author(s):  
Robert C. Fellner ◽  
Zhengrong Guan ◽  
Anthony K. Cook ◽  
David M. Pollock ◽  
Edward W. Inscho
Keyword(s):  
Receptor Activation ◽  
High Salt ◽  
Sprague Dawley ◽  
Dietary Salt ◽  
Renal Autoregulation ◽  
Sprague Dawley Rats ◽  
Afferent Arterioles

Autoregulation of renal blood flow (RBF) is an essential function of the renal microcirculation that has been previously shown to be blunted by excessive dietary salt. Endogenous endothelin 1 (ET-1) is increased following a high-salt (HS) diet and contributes to the control of RBF but the differential effects of ET-1 on renal microvessel autoregulation in response to HS remain to be established. We hypothesized that a HS diet increases endothelin receptor activation in normal Sprague-Dawley rats and blunts autoregulation of RBF. The role of ET-1 in the blunted autoregulation produced by a HS diet was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. Using highly selective antagonists, we observed that blockade of either ETA or ETB receptors was sufficient to restore normal autoregulatory behavior in afferent arterioles from HS-fed rats. Additionally, normal autoregulatory behavior was restored in vivo in HS-fed rats by simultaneous ETA and ETB receptor blockade, whereas blockade of ETB receptors alone showed significant improvement of normal autoregulation of RBF. Consistent with this observation, autoregulation of RBF in ETB receptor-deficient rats fed HS was similar to both ETB-deficient rats and transgenic control rats on normal-salt diets. These data support the hypothesis that endogenous ET-1, working through ETB and possibly ETA receptors, contributes to the blunted renal autoregulatory behavior in rats fed a HS diet.

scholarly journals Leptin induces the expression of tumorigenic genes in the gastric mucosa of male Sprague-Dawley rats

2018 ◽  
Vol 243 (14) ◽  
pp. 1118-1124 ◽  
Author(s):  
Faizatul Isyraqiah ◽  
Methil K Kutty ◽  
Damayanthi Durairajanayagam ◽  
Norita Salim ◽  
Harbindarjeet Singh
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Gastric Carcinogenesis ◽  
Control Group ◽  
Sprague Dawley ◽  
Gastric Cancer Cells ◽  
Sprague Dawley Rats

Leptin promotes the growth of gastric cancer cells in vitro. It is, however, unknown if leptin induces gastric cancer in vivo. This study therefore investigated the effect of leptin on the histology and expression of tumorigenic genes in the stomach of rats following 40 weeks of leptin treatment. Male Sprague-Dawley rats, aged 6 weeks, were randomized into control and experimental groups ( n = 8 per group). The experimental group was given intraperitoneal injections of leptin (60 µg/kg/day) once daily for 40 weeks, whereas the control group received intraperitoneal injection of an equal volume of normal saline daily. Rats were housed in polypropylene cages for the duration of the study. Body weight was measured weekly. Upon completion of treatment, rats were euthanized and their stomachs were collected for histopathological examination, microarray, and RT-qPCR. Data were analyzed using one-way ANOVA and Fisher’s exact test. On histology, one rat (12.5%) in the leptin-treated group had a large red-colored tumor nodule at the pyloric antrum of the stomach. Microscopically, stomachs of two leptin-treated rats (25%) showed hyperplasia or dysplasia. Microarray analysis revealed significant upregulation of a number of genes in the stomachs of leptin-treated rats that have been shown to be associated with tumorigenesis in other tissues, including Furin (protein maturation), Eef1a1 and Eif4g2 (translation factors), Tmed2 (vesicular trafficking), Rab7a (plasma membrane trafficking), Rfwd2 (protein degradation), Fth1 and Ftl1 (oxygen transport), Tspan8, Tspan1, Fxyd3, and Rack1 (cell migration), Pde4d (signal transduction), Nupr1 and Ybx1 (transcription factors), Ptma and Tmem134 (oncogenes), Srsf2 (mRNA maturation), and Reep5 (cell proliferation). None of the known oncogenes were, however, significantly up-regulated. In conclusion, although the overall effect of leptin on gastric carcinogenesis seems inconclusive, the findings of dysplasia and the up-regulation of some of the cancer-related genes nevertheless warrant further scrutiny on the role of leptin in gastric cancer. Impact statement Gastric cancer is the third most common cause of death due to cancer in the world. Obese individuals are at risk of developing gastric cancer, and the reason for this is unknown. Serum leptin levels are high in obese individuals and leptin is known to induce proliferation of gastric cancer cells in vitro. However, to date, no reports exist on the tumorigenic effects of leptin on the stomach in vivo. This study therefore determines if chronic leptin administration induces gastric carcinogenesis in non-obese rats, which might serve as a useful animal model for future studies. Although the findings are somewhat inconclusive, to our knowledge, however, this is the first study to show the up-regulation of numerous potential driver genes that highlight the potential role of leptin in the higher prevalence of gastric cancer among obese individuals. The findings certainly necessitate further scrutiny of leptin gastric cancer.

scholarly journals The long non-coding RNA DKFZp434J0226 regulates the alternative splicing process through phosphorylation of SF3B6 in PDAC

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Jinglei Li ◽  
Hanxing Tong ◽  
Dongping Li ◽  
Qiuyu Jiang ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Malignant Tumors ◽  
Soft Agar ◽  
Tumor Formation ◽  
Ductal Adenocarcinoma ◽  
Advanced Tumor ◽  
Tumor Node Metastasis Stage

Abstract Background Long noncoding RNAs (lncRNAs), a type of pervasive genes that regulates various biological processes, are differentially expressed in different types of malignant tumors. The role of lncRNAs in the carcinogenesis of pancreatic ductal adenocarcinoma (PDAC) remains unclear. Here, we investigated the role of the lncRNA DKFZp434J0226 in PDAC. Methods Aberrantly expressed mRNAs and lncRNAs among six PDAC and paired non-tumorous tissues were profiled using microarray analysis. Quantitative real-time polymerase chain reaction was used to evaluate DKFZp434J0226 expression in PDAC tissues. CCK-8 assay, wound-healing assay, soft agar colony formation assay, and transwell assay were performed to assess the invasiveness and proliferation of PDAC cells. Furthermore, RNA pull-down, immunofluorescence, RNA immunoprecipitation, and western blotting assays were performed to investigate the association between DKFZp434J0226 and SF3B6. Tumor xenografts in mice were used to test for tumor formation in vivo. Results In our study, 222 mRNAs and 128 lncRNAs were aberrantly expressed (≥ twofold change). Of these, 66 mRNAs and 53 lncRNAs were upregulated, while 75 lncRNAs and 156 mRNAs were downregulated. KEGG pathway analysis and the Gene ontology category indicated that these genes were associated with the regulation of mRNA alternative splicing and metabolic balance. Clinical analyses revealed that overexpression of DKFZp434J0226 was associated with worse tumor grading, frequent perineural invasion, advanced tumor-node-metastasis stage, and decreased overall survival and time to progression. Functional assays demonstrated that DKFZp434J0226 promoted PDAC cell migration, invasion, and growth in vitro and accelerated tumor proliferation in vivo. Mechanistically, DKFZp434J0226 interacted with the splicing factor SF3B6 and promoted its phosphorylation, which further regulated the alternative splicing of pre-mRNA. Conclusions This study indicates that DKFZp434J0226 regulates alternative splicing through phosphorylation of SF3B6 in PDAC and leads to an oncogenic phenotype in PDAC.

scholarly journals Pharmacological comparison of four biopolymeric natural gums as hemostatic agents for management of bleeding wounds: preliminary in vitro and in vivo results

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Himanshu Kushwah ◽  
Nidhi Sandal ◽  
Meenakshi Chauhan ◽  
Gaurav Mittal
Keyword(s):  
Xanthan Gum ◽  
Guar Gum ◽  
Human Lymphocytes ◽  
Sprague Dawley ◽  
Gum Tragacanth ◽  
Civilian Trauma ◽  
Sprague Dawley Rats ◽  
Cytotoxicity Studies

Abstract Background Uncontrolled bleeding is one of the primary reasons for preventable death in both civilian trauma and military battle field. This study evaluates in vitro and in vivo hemostatic potential of four biopolymeric natural gums, namely, gum tragacanth, guar gum, xanthan gum, and gum acacia. In vitro evaluation of whole blood clotting time and erythrocyte agglutination assay were carried out. In vitro cytotoxicity studies with respect to each gum were done in human lymphocytes to ascertain percent cell viability. In vivo hemostatic potential of each gum (as sponge dressing and powder form) was evaluated in Sprague Dawley rats using tail bleeding assay and compared with commercially available hemostatic sponge. Other important parameters like (a) time taken for complete hemostasis, (b) amount of blood absorbed, (c) adherence strength of developed hemostatic dressing(s), (d) incidence of re-bleeding, and (e) survival of animals were also studied. Results Of the four test gums studied, xanthan gum (@3mg/ml of blood) and gum tragacanth (@35mg/ml of blood) were able to clot blood in least time (58.75±6.408 s and 59.00±2.082 s, respectively) and exhibited very good hemostatic potential in vitro. Except for xanthan gum, all other test gums did not exhibit any significant cytotoxicity at different time points till 24 h. In rat tail bleeding experiments, gum tragacanth sponge dressing and powder achieved hemostasis in least time (156.2±12.86 s and 76±12.55 s, respectively) and much earlier than commercially available product (333.3±38.84 s; p˂0.01). Conclusion Results indicate potential of gum tragacanth to be developed into a suitable hemostatic product.

Bioavailability in Vivo of Benzo[a]Pyrene Adsorbed to Diesel Particulate

1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio
Keyword(s):  
Health Risks ◽  
Quantitative Description ◽  
Intratracheal Instillation ◽  
Direct Analysis ◽  
Sprague Dawley ◽  
Reasonable Estimate ◽  
Diesel Particulate ◽  
Sprague Dawley Rats

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.

scholarly journals Dissemination of Rat Cytomegalovirus through Infected Granulocytes and Monocytes In Vitro and In Vivo

2003 ◽  
Vol 77 (20) ◽  
pp. 11274-11278 ◽  
Author(s):  
B. W. A. van der Strate ◽  
J. L. Hillebrands ◽  
S. S. Lycklama à Nijeholt ◽  
L. Beljaars ◽  
C. A. Bruggeman ◽  
...  
Keyword(s):  
Intravenous Injection ◽  
Systemic Infection ◽  
Insight Into

ABSTRACT The role of leukocytes in the in vivo dissemination of cytomegalovirus was studied in this experiment. Rat cytomegalovirus (RCMV) could be transferred to rat granulocytes and monocytes by cocultivation with RCMV-infected fibroblasts in vitro. Intravenous injection of purified infected granulocytes or monocytes resulted in a systemic infection in rats, indicating that our model is a powerful tool to gain further insight into CMV dissemination and the development of new antivirals.

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