scholarly journals Guanylyl Cyclase-cGMP Signaling Pathway in Melanocytes: Differential Effects of Altered Gravity in Non-Metastatic and Metastatic Cells

2020 ◽  
Vol 21 (3) ◽  
pp. 1139 ◽  
Author(s):  
Krassimira Ivanova ◽  
Ruth Hemmersbach

Human epidermal melanocytes as melanin producing skin cells represent a crucial barrier against UV-radiation and oxidative stress. It was shown that the intracellular signaling molecule cyclic guanosine-3′,5′-monophosphate (cGMP), generated by the guanylyl cyclases (GCs), e.g., the nitric oxide (NO)-sensitive soluble GC (sGC) and the natriuretic peptide-activated particulate GC (GC-A/GC-B), plays a role in the melanocyte response to environmental stress. Importantly, cGMP is involved in NO-induced perturbation of melanocyte–extracellular matrix interactions and in addition, increased NO production during inflammation may lead to loss of melanocytes and support melanoma metastasis. Further, the NO-sensitive sGC is expressed predominantly in human melanocytes and non-metastatic melanoma cells, whereas absence of functional sGC but up-regulated expression of GC-A/GC-B and inducible NO synthase (iNOS) are detected in metastatic cells. Thus, suppression of sGC expression as well as up-regulated expression of GC-A/GC-B/iNOS appears to correlate with tumor aggressiveness. As the cGMP pathway plays important roles in melanocyte (patho)physiology, we present an overview on the differential effects of altered gravity (hypergravity/simulated microgravity) on the cGMP signaling pathway in melanocytes and melanoma cells with different metastatic potential. We believe that future experiments in real microgravity may benefit from considering cGMP signaling as a possible factor for melanocyte transformation and in medication.

2002 ◽  
Vol 282 (3) ◽  
pp. F458-F464 ◽  
Author(s):  
Sylvia Notenboom ◽  
David S. Miller ◽  
Paul Smits ◽  
Frans G. M. Russel ◽  
Rosalinde Masereeuw

We previously demonstrated in intact killifish renal proximal tubules that endothelin (ET), acting through an ETB receptor and protein kinase C (PKC), reduced transport mediated by multidrug resistance-associated protein 2 (Mrp2), i.e., luminal accumulation of fluorescein methotrexate (FL-MTX) (Masereeuw R, Terlouw SA, Van Aubel RAMH, Russel FGM, and Miller DS. Mol Pharmacol 57: 59–67, 2000). In the present study, we used confocal microscopy and quantitative image analysis to measure Mrp2-mediated transport of FL-MTX in killifish tubules as an indicator of the status of this ET-fired, intracellular signaling pathway. Exposing tubules to sodium nitroprusside (SNP), a nitric oxide (NO) donor, signaled a reduction in luminal accumulation of FL-MTX, which suggested pathway activation. N G-monomethyl-l-arginine (l-NMMA), an NO synthase inhibitor, blocked the action of ET-1 on transport. Because SNP effects on transport were blocked by bisindoylmaleide, a PKC-selective inhibitor, but not by RES-701–1, an ETB-receptor antagonist, generation of NO occurred after ETB receptor signaling but before PKC activation. NO generation was implicated in the actions of several nephrotoxicants, i.e., diatrizoate, gentamicin, amikacin, HgCl2, and CdCl2, each of which decreased Mrp2-mediated transport by activating ET signaling. For each nephrotoxicant, decreased FL-MTX transport was prevented when tubules were exposed tol-NMMA. ET-1 and each nephrotoxicant stimulated NO production by the tubules, as determined by a fluorescence-based assay. Together, the data show that NO generation follows ET binding to the basolateral ETB receptor and that, in activating the ET-signaling pathway, nephrotoxicants produce NO, a molecule that could contribute to subsequent toxic effects.


2005 ◽  
Vol 22 (6) ◽  
pp. 825-838 ◽  
Author(s):  
DOU YU ◽  
WILLIAM D. ELDRED

Nitric oxide (NO) is a free radical that is important in retinal signal transduction and cyclic guanosine monophosphate (cGMP) is a critical downstream messenger of NO. The NO/cGMP signaling pathway has been shown to modulate neurotransmitter release and gap junction coupling in horizontal cells and amacrine cells, and increase the gain of the light response in photoreceptors. However, many of the mechanisms controlling the production of NO and cGMP remain unclear. Previous studies have shown activation of NO/cGMP production in response to stimulation with N-methyl-d-aspartate (NMDA) or nicotine, and the differential modulation of cGMP production by GABAA and GABAC receptors (GABAARs and GABACRs). This study used cGMP immunocytochemistry and NO imaging to investigate how the inhibitory GABAergic and glycinergic systems modulate the production of NO and cGMP. Our data show that blocking glycine receptors (GLYR) with strychnine (STRY) produced moderate increases in cGMP-like immunoreactivity (cGMP-LI) in select types of amacrine and bipolar cells, and strong increases in NO-induced fluorescence (NO-IF). TPMPA, a selective GABACR antagonist, greatly reduced the increases in cGMP-LI stimulated by STRY, but did not influence the increase in NO-IF stimulated by STRY. Bicuculline (BIC), a GABAAR antagonist, however, enhanced the increases in both the cGMP-LI and NO-IF stimulated by STRY. CNQX, a selective antagonist for α-Amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid hydrobromide/kainic acid (AMPA/KA) receptors, eliminated both the increases in cGMP-LI and NO-IF stimulated by STRY, while MK801, a selective antagonist for NMDA receptors, slightly increased the cGMP-LI and slightly decreased the NO-IF stimulated by STRY. Finally, double labeling of NO-stimulated cGMP and either GLY or GABA indicated that cGMP predominantly colocalized with GLY. Taken together, these findings support the hypothesis that GLY and GABA interact in the regulation of the NO/cGMP signaling pathway, where GLY primarily inhibits NO production and GABA has a greater effect on cGMP production. Such interacting inhibitory pathways could shape the course of signal transduction of the NO/cGMP pathway under different physiological situations.


2019 ◽  
Vol 10 (5) ◽  
pp. 1197-1208 ◽  
Author(s):  
Qianqian Zhang ◽  
Xianguang Meng ◽  
Guojing Qin ◽  
Xiaotong Xue ◽  
Ningning Dang

2021 ◽  
Vol 17 ◽  
pp. 174480692110033
Author(s):  
Travis Okerman ◽  
Taylor Jurgenson ◽  
Madelyn Moore ◽  
Amanda H Klein

Research presented here sought to determine if opioid induced tolerance is linked to activity changes within the PI3Kγ-AKT-cGMP-JNK intracellular signaling pathway in spinal cord or peripheral nervous systems. Morphine or saline injections were given subcutaneously twice a day for five days (15 mg/kg) to male C57Bl/6 mice. A separate cohort of mice received spinal nerve ligation (SNL) one week prior to the start of morphine tolerance. Afterwards, spinal cord, dorsal root ganglia, and sciatic nerves were isolated for quantifying total and phosphorylated- JNK levels, cGMP, and gene expression analysis of Pik3cg, Akt1, Pten, and nNos1. This pathway was downregulated in the spinal cord with increased expression in the sciatic nerve of morphine tolerant and morphine tolerant mice after SNL. We also observed a significant increase in phosphorylated- JNK levels in the sciatic nerve of morphine tolerant mice with SNL. Pharmacological inhibition of PI3K or JNK, using thalidomide, quercetin, or SP600125, attenuated the development of morphine tolerance in mice with SNL as measured by thermal paw withdrawal. Overall, the PI3K/AKT intracellular signaling pathway is a potential target for reducing the development of morphine tolerance in the peripheral nervous system. Continued research into this pathway will contribute to the development of new analgesic drug therapies.


Author(s):  
Samoylova A.V. ◽  
Snimshchikova I.A. ◽  
Plotnikova M.O. ◽  
Yakushkina N.Y.

Alopecia is a common pathology among the active population, which leads not only to cosmetic defects, but also to the development of somatic diseases against the background of traumatic effects and chronic stress. The pathogenetic mechanisms of hair follicle formation are complex and diverse, since numerous factors, including the components of the Wnt signaling pathway, have an effect on its morphogenesis, the study of which is the subject of this study. The search for possible early markers of the development of alopecia led to interest in the study of the main morphogenic proteins of WNT - the signaling pathway (one of the intracellular signaling pathways, which control the development of blood vessels, as well as the growth and division of hair follicle cells) sclerostin and β-catenin among patients with androgenic and alopecia areata. The article presents data on the quantitative content of β-catenin and sclerostin in the blood serum in patients with androgenic and alopecia areata. Their possible pathways of complex interaction and influence on the morphogenesis of the hair follicle and the activity of the Wnt-signaling pathway have been analyzed, and the relationship between changes in the level of morphogenic proteins of the WNT-signaling pathway with sex and the course of the disease has been described. Establishment of the prognostic role of morphogenic proteins of the WNT signaling pathway in androgenic and alopecia areata will allow not only identify the personal risk of disease progression and to determine approaches to targeted therapy, but to develop and introduce updated diagnostic screening into dermatological practice.


2015 ◽  
Vol 32 (8) ◽  
pp. 1170-1182 ◽  
Author(s):  
A. AlQathama ◽  
J. M. Prieto

Natural products continue to provide lead cytotoxic compounds for cancer treatment but less attention has been given to antimigratory compounds. We here systematically and critically survey more than 30 natural products with direct in vitro and in vivo pharmacological effects on migration and/or metastasis of melanoma cells and chart the mechanisms of action for this underexploited property.


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