scholarly journals Calcium Oxalate Induces Renal Injury through Calcium-Sensing Receptor

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoran Li ◽  
Junhai Ma ◽  
Wei Shi ◽  
Yu Su ◽  
Xu Fu ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Calcium Oxalate ◽  
Renal Injury ◽  
Mapk Signaling ◽  
Calcium Sensing Receptor ◽  
Crystal Deposition ◽  
Calcium Sensing ◽  
Crystal Adhesion

Objective.To investigate whether calcium-sensing receptor (CaSR) plays a role in calcium-oxalate-induced renal injury.Materials and Methods.HK-2 cells and rats were treated with calcium oxalate (CaOx) crystals with or without pretreatment with the CaSR-specific agonist gadolinium chloride (GdCl3) or the CaSR-specific antagonist NPS2390. Changes in oxidative stress (OS) in HK-2 cells and rat kidneys were assessed. In addition, CaSR, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal protein kinase (JNK), and p38 expression was determined. Further, crystal adhesion assay was performedin vitro, and the serum urea and creatinine levels and crystal deposition in the kidneys were also examined.Results.CaOx increased CaSR, ERK, JNK, and p38 protein expression and OSin vitroandin vivo. These deleterious changes were further enhanced upon pretreatment with the CaSR agonist GdCl3but were attenuated by the specific CaSR inhibitor NPS2390 compared with CaOx treatment alone. Pretreatment with GdCl3further increasedin vitroandin vivocrystal adhesion and renal hypofunction. In contrast, pretreatment with NPS2390 decreasedin vitroandin vivocrystal adhesion and renal hypofunction.Conclusions.CaOx-induced renal injury is related to CaSR-mediated OS and increased mitogen-activated protein kinase (MAPK) signaling, which subsequently leads to CaOx crystal adhesion.

Peptide Blocking Self-Polymerization of Extracellular Calcium-Sensing Receptor Attenuates Hypoxia-Induced Pulmonary Hypertension

Hypertension ◽  
2021 ◽  
Author(s):  
Rui Xiao ◽  
Shengquan Luo ◽  
Ting Zhang ◽  
Yankai Lv ◽  
Tao Wang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Disulfide Bonds ◽  
Acute Hypoxia ◽  
Extracellular Domain ◽  
Left Ventricular ◽  
Extracellular Calcium ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing

Activation of the CaSR (extracellular calcium-sensing receptor) has been recognized as a critical mediator of hypoxia-induced pulmonary hypertension. Preventive targeting of the early initiating phase as well as downstream events after CaSR activation remains unexplored. As a representative of the G protein-coupled receptor family, CaSR polymerizes on cell surface upon stimulation. Immunoblotting together with MAL-PEG technique identified a reactive oxygen species-sensitive CaSR polymerization through its extracellular domain in pulmonary artery smooth muscle cells upon exposure to acute hypoxia. Fluorescence resonance energy transfer screening employing blocking peptides determined that cycteine129/131 residues in the extracellular domain of CaSR formed intermolecular disulfide bonds to promote CaSR polymerization. The monitoring of intracellular Ca 2+ signal highlighted the pivotal role of CaSR polymerization in its activation. In contrast, the blockade of disulfide bonds formation using a peptide decreased both CaSR and hypoxia-induced mitogenic factor expression as well as other hypoxic-related genes in vitro and in vivo and attenuated pulmonary hypertension development in rats. The blocking peptide did not affect systemic arterial oxygenation in vivo but inhibited acute hypoxia-induced pulmonary vasoconstriction. Pharmacokinetic analyses revealed a more efficient lung delivery of peptide by inhaled nebulizer compared to intravenous injection. In addition, the blocking peptide did not affect systemic arterial pressure, body weight, left ventricular function, liver, or kidney function or plasma Ca 2+ level. In conclusion, a peptide blocking CaSR polymerization reduces its hypoxia-induced activation and downstream events leading to pulmonary hypertension and represents an attractive inhaled preventive alternative worthy of further development.

scholarly journals The Protective Roles of Estrogen Receptor β in Renal Calcium Oxalate Crystal Formation via Reducing the Liver Oxalate Biosynthesis and Renal Oxidative Stress-Mediated Cell Injury

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Wei Zhu ◽  
Zhijian Zhao ◽  
Fu-Ju Chou ◽  
Li Zuo ◽  
Tongzu Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Estrogen Receptor ◽  
Nadph Oxidase ◽  
Calcium Oxalate ◽  
Cell Lines ◽  
Ros Production ◽  
Crystal Deposition ◽  
Caox Crystal

Females develop kidney stones less frequently than males do. However, it is unclear if this gender difference is related to altered estrogen/estrogen receptor (ER) signaling. Here, we found that ER beta (ERβ) signals could suppress hepatic oxalate biosynthesis via transcriptional upregulation of the glyoxylate aminotransferase (AGT1) expression. Results from multiple in vitro renal cell lines also found that ERβ could function via suppressing the oxalate-induced injury through increasing the reactive oxygen species (ROS) production that led to a decrease of the renal calcium oxalate (CaOx) crystal deposition. Mechanism study results showed that ERβ suppressed oxalate-induced oxidative stress via transcriptional suppression of the NADPH oxidase subunit 2 (NOX2) through direct binding to the estrogen response elements (EREs) on the NOX2 5′ promoter. We further applied two in vivo mouse models with glyoxylate-induced renal CaOx crystal deposition and one rat model with 5% hydroxyl-L-proline-induced renal CaOx crystal deposition. Our data demonstrated that mice lacking ERβ (ERβKO) as well as mice or rats treated with ERβ antagonist PHTPP had increased renal CaOx crystal deposition with increased urinary oxalate excretion and renal ROS production. Importantly, targeting ERβ-regulated NOX2 with the NADPH oxidase inhibitor, apocynin, can suppress the renal CaOx crystal deposition in the in vivo mouse model. Together, results from multiple in vitro cell lines and in vivo mouse/rat models all demonstrate that ERβ may protect against renal CaOx crystal deposition via inhibiting the hepatic oxalate biosynthesis and oxidative stress-induced renal injury.

Taurine Activates BMP-2/Wnt3a-Mediated Osteoblast Differentiation and Mineralization via Akt and MAPK Signaling

2020 ◽  
Author(s):  
Minsu PARK ◽  
Hyeon Kyeong CHOI ◽  
Jeung Hee AN
Keyword(s):  
Protein Kinase ◽  
Osteoblast Differentiation ◽  
Integration Site ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Bone Morphogenetic Protein 2 ◽  
Dependent Manner ◽  
Ovx Rats

Background: We aimed to elucidate the preventive effects of taurine against osteopenia in ovariectomized (OVX) rats and the mechanisms by which taurine regulates osteoblastogenesis in vitro and in vivo. Methods: The effects of the taurine on human osteoblast MG-63 cell differentiation and osteoblastogenesis effect in OVX rat were examined Konkuk University in 2018 by evaluating osteoblast differentiation, and expression of osteoblast-specific factors by western blotting analysis. Results: Taurine supplementation significantly improved alkaline phosphatase (ALP) activity and mineralization in a concentration-dependent manner. Further, taurine induced the expression of osteogenic growth factors such as bone morphogenetic protein-2 (BMP-2), runt-related transcription factor 2 (RUNX2), small mothers against decapentaplegic 1/5/8 (SMAD1/5/8), wingless-type MMTV integration site family member 3A (Wnt3a), and collagen type 1 (COL-1) via mitogen-activated protein kinase (MAPK) and serine/threonine protein kinase (Akt). Moreover, the RUNX2 activity of the taurine-treated group was enhanced by proteinprotein interactions such as Wnt3a-induced p-AKT/RUNX2 and BMP-mediated SMADs/MAPK/RUNX2 interactions. Conclusion: Our in vitro and in vivo results suggested that taurine can be considered as a potential therapeutic candidate agent for preventing bone loss in postmenopausal osteoporosis.

scholarly journals Calcium-Sensing Receptor and Aquaporin 2 Interplay in Hypercalciuria-Associated Renal Concentrating Defect in Humans. An In Vivo and In Vitro Study

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33145 ◽  
Author(s):  
Giuseppe Procino ◽  
Lisa Mastrofrancesco ◽  
Grazia Tamma ◽  
Domenica Rita Lasorsa ◽  
Marianna Ranieri ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Calcium Sensing Receptor ◽  
Aquaporin 2 ◽  
Calcium Sensing ◽  
Concentrating Defect

scholarly journals Pioglitazone Protected against Cardiac Hypertrophy via Inhibiting AKT/GSK3βand MAPK Signaling Pathways

PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Wen-Ying Wei ◽  
Zhen-Guo Ma ◽  
Si-Chi Xu ◽  
Ning Zhang ◽  
Qi-Zhu Tang
Keyword(s):  
Protein Kinase ◽  
Cardiac Hypertrophy ◽  
Glycogen Synthase ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Neonatal Rat ◽  
Aortic Banding ◽  
Hypertrophic Response

Peroxisome proliferator activated receptorγ(PPARγ) has been closely involved in the process of cardiovascular diseases. This study was to investigate whether pioglitazone (PIO), a PPARγagonist, could protect against pressure overload-induced cardiac hypertrophy. Mice were orally given PIO (2.5 mg/kg) from 1 week after aortic banding and continuing for 7 weeks. The morphological examination and biochemical analysis were used to evaluate the effects of PIO. Neonatal rat ventricular cardiomyocytes were also used to verify the protection of PIO against hypertrophy in vitro. The results in our study demonstrated that PIO remarkably inhibited hypertrophic response induced by aortic banding in vivo. Besides, PIO also suppressed cardiac fibrosis in vivo. PIO treatment also inhibited the activation of protein kinase B (AKT)/glycogen synthase kinase-3β(GSK3β) and mitogen-activated protein kinase (MAPK) in the heart. In addition, PIO alleviated angiotensin II-induced hypertrophic response in vitro. In conclusion, PIO could inhibit cardiac hypertrophy via attenuation of AKT/GSK3βand MAPK pathways.

scholarly journals Kokumi taste perception is functional in a model carnivore, the domestic cat (Felis catus)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Laffitte ◽  
M. Gibbs ◽  
C. Hernangomez de Alvaro ◽  
J. Addison ◽  
Z. N. Lonsdale ◽  
...  
Keyword(s):  
Amino Acids ◽  
Taste Receptor ◽  
Felis Catus ◽  
Domestic Cat ◽  
Taste Perception ◽  
Ligand Specificity ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing

AbstractKokumi taste is a well-accepted and characterised taste modality and is described as a sensation of enhancement of sweet, salty, and umami tastes. The Calcium Sensing Receptor (CaSR) has been designated as the putative kokumi taste receptor for humans, and a number of kokumi-active ligands of CaSR have been discovered recently with activity confirmed both in vivo and in vitro. Domestic cats (Felis catus) are obligate carnivores and accordingly, their diet is abundant in proteins, peptides, and amino acids. We hypothesised that CaSR is a key taste receptor for carnivores, due to its role in the detection of different peptides and amino acids in other species. Using in silico, in vitro and in vivo approaches, here we compare human CaSR to that of a model carnivore, the domestic cat. We found broad similarities in ligand specificity, but differences in taste sensitivity between the two species. Indeed our in vivo data shows that cats are sensitive to CaCl2 as a kokumi compound, but don’t show this same activity with Glutathione, whereas for humans the reverse is true. Collectively, our data suggest that kokumi is an important taste modality for carnivores that drives the palatability of meat-derived compounds such as amino acids and peptides, and that there are differences in the perception of kokumi taste between carnivores and omnivores.

scholarly journals Effects of pharmacological calcimimetics on colorectal cancer cells over-expressing the human calcium-sensing receptor

2020 ◽  
Author(s):  
Luca Iamartino ◽  
Taha Elajnaf ◽  
Katharina Gall ◽  
Jacquelina David ◽  
Teresa Manhardt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Tumor Growth ◽  
Colorectal Carcinogenesis ◽  
Inflammatory Factors ◽  
Type Ii ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing

AbstractThe calcium-sensing receptor (CaSR) is a ubiquitously expressed multifunctional G protein-coupled receptor. Several studies reported that the CaSR plays an anti-inflammatory and anti-tumorigenic role in the intestine, and that it is down-regulated during colorectal carcinogenesis. We hypothesized that intestine-specific positive allosteric CaSR modulators (type II calcimimetics) could be used for the treatment of intestinal pathologies. Therefore, the aim of this study was to determine the effect of pharmacological stimulation of CaSR on gene expression in vitro and on tumor growth in vivo.We stably transduced two colon cancer cell lines (HT29 and Caco2) with lentiviral vectors containing either the CaSR fused to GFP or GFP only. Using RNA sequencing, RT-qPCR experiments and ELISA, we determined that CaSR over-expression itself had generally little effect on gene expression in these cells. However, treatment with 1μM of the calcimimetic NPS R-568 increased the expression of pro-inflammatory factors such as IL-23α and IL-8 and reduced the transcription of various differentiation markers in the cells over-expressing the CaSR. In vivo, neither the presence of the CaSR nor p.o. treatment of the animals with the calcimimetic cinacalcet affected tumor growth, tumor cell proliferation or tumor vascularization of murine HT29 xenografts.In summary, CaSR stimulation in CaSR over-expressing cells enhanced the expression of inflammatory markers in vitro, but was not able to repress colorectal cancer tumorigenicity in vivo. These findings suggest potential pro-inflammatory effects of the CaSR and type II calcimimetics in the intestine.

scholarly journals The Extracellular Calcium-Sensing Receptor Regulates the Proliferation of Colonic Epithelial Cells In Vitro and In Vivo

2011 ◽  
Vol 140 (5) ◽  
pp. S-482
Author(s):  
Osvaldo Rey ◽  
Wenhan Chang ◽  
Daniel Bikle ◽  
Nora Rozengurt ◽  
Mary P. Moyer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Extracellular Calcium ◽  
Calcium Sensing Receptor ◽  
Colonic Epithelial Cells ◽  
Calcium Sensing
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