Evidences for the phagocytic activity of cultured rat mesangial cells

Author(s):  
Katsuyoshi Kouda ◽  
Masato Imada ◽  
Yoshio Igarashi ◽  
Akira Yamashita

It is known that glomerular mesangial cells have two major functions; the control of glomerular blood flow by contraction and the removal of macromolecules from the mesangial region by the endocytosis. As regards the latter function, the evidence of phagocytic activity for particulate materials is controversial. In this study, we attempted to make it clear whether mesangial cells isolated from glomeruli exhibit phagocytic activity in vitro.Male Sprague-Dawley rats, 6-8 wk old, were used. Glomeruli were isolated from rat renal cortex by the sieving technique according to Morita. The isolated glomeruli were cultured at 37°C in an atmosphere of 95% air, 5% CO2 in a medium containing 5ml of RPMI-1640 with 20% decomplemented fetal calf serum, and subcultured. Mesangial cells purified at the 6-20th succesive cultivations were identified by their morphology and antigenic phenotypes which were analyzed by immunohistochemical method using anti Thy-1, anti Ia, anti leukocyte common(LC) antigen, anti iC3bR, and Mar(anti rat macrophage antigen) 1-4 monoclonal antibodies. Fc receptor was detected with rosette forming method using sheep blood cells(SRBC).

1986 ◽  
Vol 251 (6) ◽  
pp. F1036-F1042 ◽  
Author(s):  
R. G. Appel ◽  
J. Wang ◽  
M. S. Simonson ◽  
M. J. Dunn

Differential in vivo glomerular effects of atriopeptin I (AP I) and atriopeptin III (AP III) were studied in parallel with in vitro physiological and biochemical parameters. In anesthetized Sprague-Dawley rats, AP III, but not AP I, significantly increased glomerular filtration rate. Image analysis microscopy was used to assess the effect of AP I and AP III on angiotensin II (ANG II)-induced contraction of cultured rat glomerular mesangial cells. AP III, but not AP I, inhibited ANG II-induced mesangial cell contraction in a concentration-dependent manner. Additional inhibitory agents included exogenous DBcGMP, 8-BrcGMP, Na nitroprusside, and DBcAMP. AP III stimulated mesangial cell cGMP with a lower threshold and greater maximum stimulation than AP I. Neither agent stimulated cAMP accumulation. Since mesangial cell contractility may regulate the glomerular capillary surface area, these results suggest that AP III partially mediates its glomerular effects through inhibition of ANG II-induced mesangial cell contraction. Whereas cGMP is not clearly implicated as the mediator of this effect, it appears that both cGMP and cAMP may regulate the state of mesangial cell contractility.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yuxuan Zhang ◽  
Juan Hao ◽  
Xuelian Ma ◽  
Qiyue Zhao ◽  
Xiaomeng Gao ◽  
...  

Objectives. To observe the effects of the Huoxue Jiedu Huayu Recipe (HJHR) on pyroptosis of glomerular mesangial cells in the contralateral unobstructed kidney (CK) of unilateral ureteral obstruction (UUO) rats. Methods. Sprague-Dawley rats were randomly divided into 4 groups: sham group, UUO group (10 days of left ureter ligation), UUO treated with eplerenone (EPL) (UUO + EPL) group, and UUO treated with HJHR (UUO + HJHR) group. The CKs of all rats were collected for studies. Results. Cell pyroptosis and macrophage infiltration was found in contralateral glomeruli, and nucleotide-binding oligomerization domain-like pyrin domain containing protein 3 (NLRP3) and interleukin (IL)-1β expression was upregulated in the CK of UUO rats. All of these changes were inhibited by HJHR and eplerenone. To determine how aldosterone (Aldo) activated the mineralocorticoid receptor (MR) and then induced mesangial cell pyroptosis with NLRP3-caspase-1-IL-1β pathway, human mesangial cells (HMCs) were treated with HJHR and eplerenone, which were examined to detect the expression of NLRP3 inflammasome-associated proteins following treatment with Aldo. Conclusion. These results suggest that HJHR and eplerenone suppressed HMC pyroptosis via the MR/NLRP3 pathway.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Himanshu Kushwah ◽  
Nidhi Sandal ◽  
Meenakshi Chauhan ◽  
Gaurav Mittal

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.


2011 ◽  
Vol 75 (3) ◽  
pp. 429-433 ◽  
Author(s):  
F.G. Leivas ◽  
D.S. Brum ◽  
S.S. Fialho ◽  
W.P. Saliba ◽  
M.T.T. Alvim ◽  
...  

1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio

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.


2013 ◽  
Vol 32 (5) ◽  
pp. 385-394 ◽  
Author(s):  
Antoinette Y. Odendaal ◽  
Narendra S. Deshmukh ◽  
Tennille K. Marx ◽  
Alexander G. Schauss ◽  
John R. Endres ◽  
...  

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 μg of extract/plate (Ames test) or 5000 μg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Jana Holmar ◽  
Heidi Noels ◽  
Joachim Jankowski ◽  
Setareh Orth-Alampour

Abstract Background and Aims Vascular calcification (VC) is one major complication in patients with chronic kidney disease whereas a misbalance in calcium and phosphate metabolism plays a crucial role. The mechanisms underlying VC have not been entirely revealed to date. Therefore are the studies aiming at the identification and characterization of the mediators/uremic toxins involved in VC ongoing and highly relevant. However, currently many different protocols being used in the studies of vascular calcification processes. This complicates the comparison of study outcomes, composing systematic reviews, and meta-analyses. Moreover, the reproducibility of data is hampered, and the efficiency in calcification research through the lack of a standardized protocol is reduced. In this study, we developed a standardized operating protocol for in vitro and ex vivo approaches to aiming at the comparability of these studies. Method We analysed in vitro and ex vivo experimental conditions to study VC. Vascular smooth muscle cells (HAoSMCs) were used for in vitro experiments and aortas from Wistar rats were used for ex vivo experiments. The influence of the following conditions was studied in detail: • Phosphate and calcium concentrations in calcifying media. • Incubation time. • Fetal calf serum (FCS) concentration. The degree of calcification was estimated by quantification of calcium concentrations that were normalized to protein content (in vitro) or to the dry weight of the aortic ring (ex vivo). Additionally, the aortic rings were stained using the von Kossa method. Optimal conditions for investigating medial vascular calcification were detected and summarized in the step-by-step protocol. Results We were able to demonstrate that the degree and the location of VC in vascular smooth muscle cells and aortic rings were highly dependent on the phosphate and CaCl2 concentration in the medium as well as the incubation time. Furthermore, the VC was reduced upon increasing fetal calf serum concentration in the medium. An optimized protocol for studying vascular calcification in vitro and ex vivo was developed and validated. The final protocol (Figure 1) presented will help to standardize in vitro and ex vivo approaches to investigate the processes of vascular calcification. Conclusion In the current study, we developed and validated a standardized operating protocol for systematic in vitro and ex vivo analyses of medial calcification, which is essential for the comparability of the results of future studies.


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