JNK Signaling Pathway Mediates Fluoride-Induced Upregulation of CK1α during Enamel Formation

2021 ◽  
pp. 1-9
Author(s):  
Zhongrui Yang ◽  
Guanghui Shi ◽  
Jing Guo ◽  
Yanyan Zhou ◽  
Jie Jia

Fluorosis is a defect in the enamel mineral content caused by excessive fluoride intake during amelogenesis; the interaction of various factors in the development and progression of fluorosis has not been defined. Casein kinase 1α (CK1α) is constitutively active in cells and is involved in diverse cellular processes; however, its expression in fluorosis has not been measured. This study aimed to investigate the effects of fluoride on CK1α expression and to assess the regulation of molecular signaling involving fluoride and CK1α during enamel development. Kunming mice were randomly divided into the control and F groups with induced clinical features of fluorosis. The F group mice, including mothers and newborns, were treated with 50 ppm fluoridated water. Immunohistochemical staining of the sections of the embryonic mandible regions was performed at the bell stage. Protein expression and signaling pathways in a mouse-derived ameloblast-like cell line (LS8) exposed to fluoride or a Jun N-terminal kinase (JNK) inhibitor were compared to those in control cells without exposure. CK1α and proteins of the JNK signaling pathways were assayed by quantitative real-time PCR and Western blotting. Mice of the F group developed dental fluorosis. Scanning electron microscopy showed a significant reduction in the degree of mineralization in the F group mice, which manifested as thin, loosely arranged, and disorganized enamel rods. Additional analysis revealed that the expression of CK1α in the F group was significantly elevated compared with that in the control group; LS8 cells responded to fluoride by upregulation of CK1α expression through the JNK pathway. Our findings identified the potential effects of CK1α on fluorosis using a mouse model and revealed that a high fluoride level increases the expression of CK1α and that JNK can be a key regulatory factor in CK1α expression.

2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Renato Francesco Maria Scalise ◽  
Rosalba De Sarro ◽  
Alessandro Caracciolo ◽  
Rita Lauro ◽  
Francesco Squadrito ◽  
...  

The ischemic injury caused by myocardial infarction activates a complex healing process wherein a powerful inflammatory response and a reparative phase follow and balance each other. An intricate network of mediators finely orchestrate a large variety of cellular subtypes throughout molecular signaling pathways that determine the intensity and duration of each phase. At the end of this process, the necrotic tissue is replaced with a fibrotic scar whose quality strictly depends on the delicate balance resulting from the interaction between multiple actors involved in fibrogenesis. An inflammatory or reparative dysregulation, both in term of excess and deficiency, may cause ventricular dysfunction and life-threatening arrhythmias that heavily affect clinical outcome. This review discusses cellular process and molecular signaling pathways that determine fibrosis and the imaging technique that can characterize the clinical impact of this process in-vivo.


ISRN Virology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Pei-I Chi ◽  
Hung-Jen Liu

The cell signaling plays a pivotal role in regulating cellular processes and is often manipulated by viruses as they rely on the functions offered by cells for their propagation. The first stage of their host life is to pass the genetic materials into the cell. Although some viruses can directly penetrate into cytosol, in fact, most virus entry into their host cells is through endocytosis. This machinery initiates with cell type specific cellular signaling pathways, and the signaling compounds can be proteins, lipids, and carbohydrates. The activation can be triggered in a very short time after virus binds on target cells, such as receptors. The signaling pathways involved in regulation of viral entry are wide diversity that often cross-talk between different endocytosis results. Furthermore, some viruses have the ability to use the multiple internalization pathways which leads to the regulation being even more complex. In this paper, we discuss some recent advances in our understanding of cellular pathways for virus entry, molecular signaling during virus entry, formation of endocytic vesicles, and the traffic.


2020 ◽  
Vol 11 (9) ◽  
pp. 8297-8308
Author(s):  
Yuanyuan Li ◽  
Jialin Xu ◽  
Dongli Li ◽  
Hang Ma ◽  
Yu Mu ◽  
...  

GUB, a main phenolic compound present in guava fruits, could alleviate APAP-induced liver injury in vitro and in vivo by activating the Nrf2 signaling pathway and inhibiting the JNK signaling pathway.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 857 ◽  
Author(s):  
Manel Hammouda ◽  
Amy Ford ◽  
Yuan Liu ◽  
Jennifer Zhang

The c-Jun N-terminal kinases (JNKs), with its members JNK1, JNK2, and JNK3, is a subfamily of (MAPK) mitogen-activated protein kinases. JNK signaling regulates a wide range of cellular processes, including cell proliferation, differentiation, survival, apoptosis, and inflammation. Dysregulation of JNK pathway is associated with a wide range of immune disorders and cancer. Our objective is to provide a review of JNK proteins and their upstream regulators and downstream effector molecules in common skin disorders, including psoriasis, dermal fibrosis, scleroderma, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.


2020 ◽  
Vol 102 (6) ◽  
pp. 1270-1280 ◽  
Author(s):  
Gamze Bildik ◽  
Nazli Akin ◽  
Yashar Esmaeilian ◽  
Francesko Hela ◽  
Kayhan Yakin ◽  
...  

Abstract Human chorionic gonadotropin (hCG) is a luteotropic hormone that promotes the survival and steroidogenic activity of corpus luteum (CL) by acting through luteinizing hormone receptors (LHRs) expressed on luteinized theca and granulosa cells (GCs). Therefore, it is used to support luteal phase in in vitro fertilization (IVF) cycles to improve clinical pregnancy rates and prevent miscarriage. However, the molecular mechanism underlying this action of hCG is not well characterized. To address this question, we designed an in vitro translational research study on the luteal GCs obtained from 58 IVF patients. hCG treatment at different concentrations and time points activated c-Jun N-terminal kinase (JNK) pathway and significantly increased its endogenous kinase activity along with upregulated expression of steroidogenic enzymes (steroidogenic acute regulatory protein (stAR), 3β-Hydroxysteroid dehydrogenase (3β-HSD)) in a dose-dependent manner in the luteal GCs. As a result, in vitro P production of the cells was significantly enhanced after hCG. When JNK pathway was inhibited pharmacologically or knocked-down with small interfering RNA luteal function was compromised, P4 production was declined along with the expression of stAR and 3β-HSD in the cells. Further, hCG treatment after JNK inhibition failed to correct the luteal defect and promote P4 output. Similar to hCG, luteinizing hormone (LH) treatment improved luteal function as well and this action of LH was associated with JNK activation in the luteal GCs. These findings could be important from the perspective of CL biology and luteal phase in human because we for the first time identify a critical role for JNK signaling pathway downstream LHR activation by hCG/LH in luteal GCs. Summary Sentence JNK signaling pathway plays a central role in the upregulated expression of the steroidogenic enzymes StAR and 3b-HSD and augmented progesterone production by hCG/LH in human luteal granulosa cells.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yangfang Ding ◽  
Qi Xie ◽  
Wenjing Liu ◽  
Zhaohai Pan ◽  
Xinmei Fan ◽  
...  

The botanical constituents of Stellera chamaejasme Linn. exhibit various pharmacological and medicinal activities. Neochamaejasmin A (NCA), one main active constituent of S. chamaejasme, inhibits cell proliferation and induces cell apoptosis in several types of tumor cells. However, the antitumor effect of NCA on hepatocellular carcinoma cells is still unclear. In this study, NCA (36.9, 73.7, and 147.5 μM) significantly inhibited hepatoblastoma-derived HepG2 cell proliferation in a concentration-dependent manner. Hoechst 33258 staining and flow cytometry showed that apoptotic morphological changes were observed and the apoptotic rate was significantly increased in NCA-treated HepG2 cells, respectively. Additionally, the levels of Bax, cleaved caspase-3, and cytoplasmic cytochrome c were increased, while the level of Bcl-2 was decreased in NCA-treated HepG2 cells when compared with the control group. Moreover, we found that the reactive oxygen species (ROS) level was significantly higher and the mitochondrial membrane potential was remarkably lower in NCA-treated HepG2 cells than in the control group. Further studies demonstrated that the levels of p-JNK and p-ERK1/2 were significantly upregulated in NCA-treated HepG2 cells, and pretreatment with JNK and ERK1/2 inhibitors, SP600125 and PD0325901, respectively, suppressed NCA-induced cell apoptosis of HepG2 cells. In addition, NCA also significantly inhibited human hepatoma BEL-7402 cell proliferation and induced cell apoptosis through the ROS-mediated mitochondrial apoptotic pathway. These results implied that NCA induced mitochondrial-mediated cell apoptosis via ROS-dependent activation of the ERK1/2/JNK signaling pathway in HepG2 cells.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22004-e22004
Author(s):  
Ozgur Oktem ◽  
Meltem Muftuoglu ◽  
Filiz Senbabaoglu ◽  
Bulent Urman

e22004 Background: No data are available regarding the signaling pathways that controls the proliferation of granulosa cell tumors (GCT). Preliminary findings showing the activation of c-Jun N-terminal kinase (JNK) signaling pathway in the proliferating granulosa cells has led us to investigate the role of this pathway in human GCT. Methods: Human GCT line COV 434 was used. Cell proliferation was monitored real-time quantitatively for 120h using an impedance-based system. Two different pharmacologic JNK inhibitors SP600125 and AS601245 were used. Their inhibitory concentrations were determined in western blot. Cell cycle was analyzed with flow cytometry and apoptosis with yo-pro-1 staining. Results: First, the growth characteristics of this cell line was delineated (Table 1A). Then the cells were treated with the inhibitors at the indicated doses during the log phase. Their proliferation was significantly halted in a dose-dependent manner by both inhibitors (Table 1B). Furthermore, the cells failed to complete mitosis, and began to accumulate at G2 in a dose dependent manner when JNK pathway was interrupted with AS601245 (59%) and SP600125 (39%) during G2/M transition compared to control cells (7%) proceeding through G2/M phase regularly (p<0.001). Compared to 3.5% of control cells, 14% and 30% of the cells underwent apoptosis when treated with 50 µM SP600125 and AS601245, respectively. At 100 µM, the apoptotic fraction increased to 68% and 76%, respectively (p<0.01). Conclusions: These results suggest that pharmacologic manipulation of JNK pathway may provide a therapeutic benefit in the treatment of GCT for which currently, no curative therapy exists beyond surgery. Funded by a Grant to Ozgur Oktem (TUBITAK109S164). [Table: see text]


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Gamze Bildik ◽  
Nazli Akin ◽  
Yashar Esmaeilian ◽  
Francesko Hela ◽  
Ceren Sultan Yildiz ◽  
...  

Abstract Molecular mechanisms underlying luteinization (terminal differentiation of granulosa and theca cells after ovulation) and luteolysis (demise of corpus luteum) are poorly understood in human ovary. Here we report that activin-A, after binding to its cognate receptors induces a functional luteolytic state and reverses luteinization phenotype by downregulating the expression of the steroidogenic enzymes, LH receptor and VEGF and reducing estradiol (E2) progesterone (P4) production and upregulating FSH receptor and cyclin D1 expression in human primary luteinized granulosa cells. Further, this action of activin-A involves downregulation of JNK signaling pathway and is opposite to that of human chorionic gonadotropin (hCG), which acts as a luteotropic hormone and improves luteal function through the activation of JNK pathway in the same cell type. Reversal of luteinization phenotype in luteal granulosa cells by activin-A potentially makes this hormone an attractive candidate for use under certain clinical situations, where induction of luteolysis and rapid reduction of endogenous sex steroid levels are beneficial such as ovarian hyperstimulation syndrome (OHSS), in which the ovaries hyper-respond to gonadotropin stimulation by producing too many growing follicles along with development of ascites, pleural effusion, and hemo-concentrations as a result of increased vascular permeability and leakage of intravascular volume into third spaces. Our work unveils a previously undefined role for activin-A and JNK signaling pathway in human corpus luteum biology, that might have a direct clinical impact in assisted reproductive technologies.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Ling-Ling Zhang ◽  
Bing Chen ◽  
Xiao-Yun Fan ◽  
Sha-Sha Wu ◽  
Sheng-Quan Zhang ◽  
...  

Objective. Herein, we aimed to study the mechanism whereby poly-L-arginine (PLA) and lipopolysaccharide (LPS) can synergistically induce the release of interleukin-6 (IL-6) and IL-8 in NCI-H292 cells.Methods. NCI-H292 cells were divided into control, PLA, LPS, and PLA+LPS groups. At various time points, the phosphorylation of JNK in each group was measured by western blotting. Additionally, the productions of IL-6 and IL-8 were assessed using an enzyme-linked immunosorbent assay (ELISA). The effects of SP600125, an inhibitor of the JNK pathway, on the increase of p-JNK, IL-6, and IL-8 were also studied.Results. Our results showed that either PLA or LPS treatment alone can significantly increase the phosphorylation level of JNK in NCI-H292 cells. Of interest was the combined use of PLA and LPS that has a synergistic effect on the phosphorylation of JNK, as well as synergistically inducing the release of IL-6 and IL-8 in NCI-H292 cells. Furthermore, SP600125 significantly inhibited the activation of JNK signal, as well as reducing the productions of IL-6 and IL-8 in response to PLA+LPS stimulation.Conclusions. The JNK signaling pathway contributes to the release of IL-6 and IL-8, which is stimulated by the synergistic actions of PLA+LPS in NCI-H292 cells.


2020 ◽  
Vol 29 (04) ◽  
pp. 259-263
Author(s):  
Iftekhar Ahmed ◽  
◽  
Anwar Ali ◽  
Marium Zaheer ◽  
Ibraj Fatima ◽  
...  

OBJECTIVE: The objective of this study is to see the frequency of dental fluorosis in exposed area (Sammo Rind village of Thar District) and in unexposed area of Gadap town of Karachi and to find the association of fluoride level with dental fluorosis in both groups. METHODOLOGY: The water samples were taken from both the sites and fluoride estimation in water and geometrical, was determined using Fluoride Ion Selective Electrode (FISE) method. By random selection 121 subjects from Sammo Rind village and 121 controls from Gadap Town Karachi were included in study after informed consent. The participants were clinically examined by an expert university teacher dentist in proper dental setups in examination lights. RESULTS: A frequency of dental fluorosis of 100% was found among the study subjects with fluoride content as high as 6- 8 mg/dl as compared to prevalence of dental fluorosis 17.4% in unexposed group with water fluoride content as low as 0.30mg/dl. CONCLUSIONS: The high level of underground water fluoride level and cent per cent dental fluorosis in Thar area is an alarming situation that should be addressed immediately at national level. KEYWORDS: Exposed area, Dental Flurosis, Fluoride Level, Water Sample HOW TO CITE: Ahmed I, Ali A, Zaheer M, Fatima I, Khan N. Frequency of dental fluorosis in population drinking water with high fluoride level in Thar. J Pak Dent Assoc 2020;29(4):259-263. DOI: https://doi.org/10.25301/JPDA.294.259


Sign in / Sign up

Export Citation Format

Share Document