scholarly journals P-Glycoprotein Inhibitor Tariquidar Plays an Important Regulatory Role in Pigmentation in Larval Zebrafish

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 690
Author(s):  
Natalia Kasica ◽  
Piotr Jakubowski ◽  
Jerzy Kaleczyc
Keyword(s):  
Pigment Cell ◽  
Expression Patterns ◽  
Cell Formation ◽  
Differentiation Markers ◽  
Dopachrome Tautomerase ◽  
Forkhead Box ◽  
P Glycoprotein ◽  
Development And Differentiation ◽  
Dose Dependent ◽  
Tyrosinase Related Protein

Zebrafish has emerged as a powerful model in studies dealing with pigment development and pathobiology of pigment diseases. Due to its conserved pigment pattern with established genetic background, the zebrafish is used for screening of active compounds influencing melanophore, iridophore, and xanthophore development and differentiation. In our study, zebrafish embryos and larvae were used to investigate the influence of third-generation noncompetitive P-glycoprotein inhibitor, tariquidar (TQR), on pigmentation, including phenotype effects and changes in gene expression of chosen chromatophore differentiation markers. Five-day exposure to increasing TQR concentrations (1 µM, 10 µM, and 50 µM) resulted in a dose-dependent augmentation of the area covered with melanophores but a reduction in the area covered by iridophores. The observations were performed in three distinct regions—the eye, dorsal head, and tail. Moreover, TQR enhanced melanophore renewal after depigmentation caused by 0.2 mM 1-phenyl-2-thiourea (PTU) treatment. qPCR analysis performed in 56-h post-fertilization (hpf) embryos demonstrated differential expression patterns of genes related to pigment development and differentiation. The most substantial findings include those indicating that TQR had no significant influence on leukocyte tyrosine kinase, GTP cyclohydrolase 2, tyrosinase-related protein 1, and forkhead box D3, however, markedly upregulated tyrosinase, dopachrome tautomerase and melanocyte inducing transcription factor, and downregulated purine nucleoside phosphorylase 4a. The present study suggests that TQR is an agent with multidirectional properties toward pigment cell formation and distribution in the zebrafish larvae and therefore points to the involvement of P-glycoprotein in this process.

scholarly journals Tara Tannin Regulates Pigmentation by Modulating Melanogenesis Enzymes and Melanosome Transport Proteins Expression

2020 ◽  
Vol 7 (01) ◽  
pp. e34-e44
Author(s):  
Myra O. Villareal ◽  
Thanyanan Chaochaiphat ◽  
Meriem Bejaoui ◽  
Kozo Sato ◽  
Hiroko Isoda
Keyword(s):  
Skin Color ◽  
Pigment Cell ◽  
Underlying Mechanism ◽  
Mapk Signaling ◽  
Transport Proteins ◽  
Related Protein ◽  
Promoting Effect ◽  
Dopachrome Tautomerase ◽  
Tyrosinase Related Protein

AbstractThe skin color is imparted by the pigment melanin produced in the melanosomes of melanocytes, through the catalytic action of melanogenesis enzymes tyrosinase, tyrosinase-related protein 1, and dopachrome tautomerase. Disruptions in the melanogenesis process may result to hypopigmentation, as observed in cutaneous postinflammatory conditions. Here, the bioactivity of tara tannin, specifically on melanogenesis, was evaluated in vitro using human epidermal melanocytes (HEM) and B16F10 murine melanoma cells in order to determine the possibility that it may be used as a treatment against hypopigmentation. The melanin content of tara tannin-treated B16F10 cells and the expression level of melanogenesis enzymes and melanosome transport proteins were determined. To elucidate the underlying mechanism of tara tannin’s effect on melanogenesis, DNA microarray analysis was performed. Tara tannin significantly increased melanogenesis in both murine and human pigment cell models by upregulating melanogenesis-associated enzymes’ (tyrosinase, tyrosinase-related protein 1, and dopachrome tautomerase) protein and mRNA expression levels, as well as the melanosome transport proteins (myosin Va and RAB27A) expression, both attributed to increased microphthalmia-associated transcription factor (MITF) expression. Global gene expression analysis results revealed the modulation of genes (p≤0.05; fold-change ≥2.0 and ≤−2.0) that are under the transcriptional regulation of MITF and genes relevant for MAPK signaling, metabolic pathways, and cell cycle. Tara tannin has a significant effective melanogenesis-promoting effect, making it a potential therapeutic agent against hypopigmentation disorders. This is the first report on the melanogenesis regulatory effect of tara tannin in vitro.

Abstract 837: Beta1 And Beta2 Adrenergic Receptor Transgenic Mice Display Distinct MicroRNA Expression Patterns That Converge On The Hypertrophic Signature

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Danish Sayed ◽  
Shweta Rane ◽  
Leng-Yi Chen ◽  
Minzhen He ◽  
Jacqueline Lypowy ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Adrenergic Receptor ◽  
Mapk Pathway ◽  
Expression Patterns ◽  
Pressure Overload ◽  
Mapk Signaling ◽  
Compensatory Hypertrophy ◽  
Over Expression ◽  
Mrna Targets ◽  
Dose Dependent

MicroRNA (miRNA) are ~22 ribonucleotides-long, with a potential to recognize multiple mRNA targets guided by sequence complimentarity. This class of molecules is functionally versatile, with the capacity to specifically inhibit translation, as well as, induce mRNA degradation, through targeting the 3′-untranslated regions. The levels of individual miRNA vary under different developmental, biological, or pathological conditions, thus, implicating them in normal and pathological cellular attributes. We have previously reported a miRNA signature that distinguishes pressure-overload compensatory hypertrophy by recapitulating the neonatal pattern. We hypothesized that this ’signature’ might aid in discriminating the underlying molecular differences in genetic models of cardiac hypertrophy, as seen in the beta1 and 2 adrenergic receptor (B1AR and B2AR) transgenic (Tg) mice. To address this, we used microarray analysis of RNA isolated from the hearts of 3 months old B1AR and B2AR mice. In general, while both mice exhibited an overlap with the hypertrophy signature including, upregulation of miR-21 and downregulation of miR-133a, miR-133b, and miR-185, the B2-AR Tg exhibited a more extensive overlap with the hypertrophy pattern, which further included upregulation of miR-199a*, miR-214, and miR-15b. To understand the functional significance of these miRNA in myocyte hypertrophy, we cloned them and their anti-sense sequences into adenoviral vectors. Significantly, over-expression miR-21 resulted in a, dose-dependent, branching (sprouting) of the cells. Computational predictions by ’TargetScanS’ identified sprouty as potential target. Subsequently, we confirmed down-regulation of sprouty by over-expression of miR-21 and vice versa. Sprouty is a known inhibitor of the Ras-MAPK signaling pathway and is, concordantly, downregulated in many forms of cancer. In the heart, sprouty has been suggested to control myocyte size and vascularization during cardiac hypertrophy. Thus, we propose that B1AR and B2AR Tg models exhibit distinct miRNA profiles that converge on that of pressure-overload cardiac hypertrophy. Moreover, the commonly over-expressed miR-21 plays a role in downregulating sprouty, an antagonist of the Ras-MAPK pathway.

Effect of Clarithromycin on Steady-State Digoxin Concentrations

2003 ◽  
Vol 37 (2) ◽  
pp. 178-181 ◽  
Author(s):  
Hideko Tanaka ◽  
Kana Matsumoto ◽  
Kazuyuki Ueno ◽  
Mayumi Kodama ◽  
Kohji Yoneda ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Digoxin Concentration ◽  
Concomitant Administration ◽  
Percentage Increase ◽  
P Glycoprotein ◽  
Before And After ◽  
Glycoprotein Inhibitors ◽  
Dose Dependent ◽  
Digoxin Therapy

OBJECTIVE: To evaluate the magnitude and dose-relatedness of the effect of clarithromycin on the pharmacokinetics of digoxin, and to compare the effects of clarithromycin with those of P-glycoprotein inhibitors. METHODS: Eight Japanese inpatients with congestive heart failure participated in this study. Each patient received oral digoxin therapy for at least 7 days and were coadministered oral clarithromycin to prevent or treat pneumonia. To evaluate the effects of clarithromycin on the pharmacokinetics of digoxin, digoxin concentrations were compared before and after coadministration of clarithromycin. RESULTS: Digoxin concentrations were higher after coadministration of clarithromycin in all patients (before, 0.838 ± 0.329 ng/mL; after, 1.36 ± 0.619 ng/mL); (p < 0.005). A significant correlation was observed between the dose of clarithromycin and the percentage of increase in the digoxin concentration. CONCLUSIONS: Digoxin concentrations increased during concomitant administration of clarithromycin, and this effect was dose-dependent on clarithromycin. The percentage increase in digoxin concentrations after the usual oral dose of clarithromycin (400 mg/d) is approximately 70%. Therefore, digoxin concentrations must be monitored carefully after coadministration of clarithromycin, and the doses of digoxin may need readjustment in patients who are concomitantly receiving clarithromycin.

scholarly journals Exploring the potential effect and mechanisms of protocatechuic acid on human hair follicle melanocytes

2020 ◽  
Vol 70 (4) ◽  
pp. 539-549
Author(s):  
Bo Li ◽  
Jun Tan ◽  
Bosheng Zou ◽  
Xiaojia Liu ◽  
Yiling Yu
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Protocatechuic Acid ◽  
Treatment Time ◽  
Tyrosinase Activity ◽  
Dependent Manner ◽  
Related Protein ◽  
Human Hair Follicle ◽  
Dose Dependent ◽  
Tyrosinase Related Protein

AbstractThis study aims to evaluate the effect of protocatechuic acid (PCA) on human hair follicle melanocytes (HFM). Normal primary HFM were isolated and cultured till logarithmic period of second passage, then treated with different concentrations of PCA (0.1–200 μmol L−1) to study the cell proliferation, melanin contents, tyrosinase activity and protein and mRNA expression of melanogenic genes (tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 2 (TRP-2), and microphthalmia-associated transcription factor (MITF)) in the cultured HFM. In addition, we have also measured the contents of superoxide dismutase (SOD) and glutathione (GSH) in PCA treated HFM. Vitamin C was used as a positive control. The result showed that PCA can decrease the synthesis of melanin and the tyrosinase activity with IC50 = 8.9 μmol L−1 and IC50 = 6.4 μmol L−1, respectively, at the treatment time of 24 hours, without inducing any cytotoxicity in HFM cells. In addition, the mRNA transcription and protein expression levels of TRP-1, TRP-2 and MITF significantly decreased with a dose-dependent manner after 24-hour PCA treated in HFM cells. Furthermore, PCA has significantly increased the SOD and GSH activity in a dose-dependent manner for 24-hour PCA treatment. This study suggested that PCA has an inhibitory effect on the production of melanin through down-regulation of the expression of melanogenesis-related protein and the effect of anti-oxidation, which could be useful for the therapy of melanin overproduction or skin whitening.

scholarly journals Specific Responses in Rat Small Intestinal Epithelial mRNA Expression and Protein Levels During Chemotherapeutic Damage and Regeneration

2002 ◽  
Vol 50 (11) ◽  
pp. 1525-1536 ◽  
Author(s):  
Melissa Verburg ◽  
Ingrid B. Renes ◽  
Danielle J.P.M. Van Nispen ◽  
Sacha Ferdinandusse ◽  
Marieke Jorritsma ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Goblet Cell ◽  
Expression Patterns ◽  
Paneth Cell ◽  
Cytostatic Drug ◽  
Differentiation Markers ◽  
Protein Levels ◽  
Cell Functions ◽  
Enhanced Expression ◽  
Small Intestinal

The rapidly dividing small intestinal epithelium is very sensitive to the cytostatic drug methotrexate. We investigated the regulation of epithelial gene expression in rat jejunum during methotrexate-induced damage and regeneration. Ten differentiation markers were localized on tissue sections and quantified at mRNA and protein levels relative to control levels. We analyzed correlations in temporal expression patterns between markers. mRNA expression of enterocyte and goblet cell markers decreased significantly during damage for a specific period. Of these, sucrase-isomaltase (-62%) and CPS (-82%) were correlated. Correlations were also found between lactase (−76%) and SGLT1 (−77%) and between I-FABP (−52%) and L-FABP (-45%). Decreases in GLUT5 (−53%), MUC2 (-43%), and TFF3 (−54%) mRNAs occurred independently of any of the other markers. In contrast, lysozyme mRNA present in Paneth cells increased (+76%). At the protein level, qualitative and quantitative changes were in agreement with mRNA expression, except for Muc2 (+115%) and TFF3 (+81%), which increased significantly during damage, following independent patterns. During regeneration, expression of each marker returned to control levels. The enhanced expression of cytoprotective molecules (Muc2, TFF3, lysozyme) during damage represents maintenance of goblet cell and Paneth cell functions, most likely to protect the epithelium. Decreased expression of enterocyte-specific markers represents decreased enterocyte function, of which fatty acid transporters were least affected.

scholarly journals Anti-Melanogenic Effects of Hydroxyectoine via MITF Inhibition by JNK, p38, and AKT Pathways in B16F10 Melanoma Cells

2019 ◽  
Vol 14 (6) ◽  
pp. 1934578X1985852 ◽  
Author(s):  
You C. Chung ◽  
Min-Jin Kim ◽  
Eun Y. Kang ◽  
Yun B. Kim ◽  
Bong S. Kim ◽  
...  
Keyword(s):  
Skin Color ◽  
Inhibitory Effect ◽  
Tyrosinase Activity ◽  
Dependent Manner ◽  
Related Protein ◽  
B16f10 Melanoma ◽  
Melanin Production ◽  
B16f10 Cells ◽  
Dose Dependent ◽  
Tyrosinase Related Protein

Melanin plays a role in determining human skin color of a person, and a large amount of melanin makes the skin color look darkened. The proper amount of melanin formation protects our skin from UV radiation, but excessive melanin production causes hyperpigmentation and leads to freckles, melasma, and lentigo. In this study, we investigated the inhibitory effect of hydroxyectoine on melanogenesis and its mechanism in B16F10 cells. Melanin content and cellular tyrosinase activity were determined. The expression of microphthalmia-associated transcription factor (MITF), and the activities of tyrosinase and other melanogenesis-related enzymes, such as tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2, were also examined. Hydroxyectoine treatment significantly inhibited melanin production and intracellular tyrosinase activity in a dose-dependent manner. Western blot analysis showed that hydroxyectoine also reduced the expressions of tyrosinase and TRP-1. In addition, hydroxyectoine significantly reduced the expression of MITF, a major regulator of melanin production, and inhibited the phosphorylation of p38, c-Jun N-terminal kinase, and activated the protein kinase B. The results demonstrated that hydroxyectoine inhibits the expression of MITF through the inhibition or activation of melanin-related signaling pathways and downregulates melanogenesis by inhibiting melanogenic enzyme expression and tyrosinase activity. Hydroxyectoine has potential value in functional cosmetics applications, such as whitening.

Phase I/II trial of cyclosporine as a chemotherapy-resistance modifier in acute leukemia.

1993 ◽  
Vol 11 (9) ◽  
pp. 1652-1660 ◽  
Author(s):  
A F List ◽  
C Spier ◽  
J Greer ◽  
S Wolff ◽  
J Hutter ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Phase I ◽  
Response Rate ◽  
Chronic Phase ◽  
Response To Treatment ◽  
Mdr1 Gene ◽  
Gene Transcript ◽  
Blood Concentrations ◽  
P Glycoprotein ◽  
Dose Dependent

PURPOSE To determine the toxicities and maximum-tolerated dose of cyclosporine (CsA) administered with daunorubicin as a modulator of multidrug resistance (MDR) in acute leukemia, and to evaluate response to treatment and its relationship to mdr1 gene expression. PATIENTS AND METHODS Patients with poor-risk acute myeloid leukemia (AML) received sequential treatment with cytarabine (3 g/m2/d intravenously [i.v.]) days 1 to 5, and daunorubicin (45 mg/m2/d) plus CsA as a 72-hour continuous infusion (CI) days 6 through 8 in a phase I/II trial. A loading dose of CsA administered over 1 to 2 hours preceded the CI. CsA dose escalations ranged from 1.4 to 6 mg/kg (load) and 1.5 to 20 mg/kg/d (CI). Whole-blood concentrations of CsA were monitored by immunoassay; plasma concentration of daunorubicin and daunorubicinol were determined by high-pressure liquid chromatography (HPLC). Specimens were analyzed for P-glycoprotein expression, and results confirmed by a quantitative RNA polymerase chain reaction (PCR) assay for the mdr1 gene transcript. RESULTS Forty-two patients are assessable for toxicity and response. P-glycoprotein was detected in 70% of cases. Dose-dependent CsA toxicities included nausea and vomiting (22%), hypomagnesemia (61%), burning dysesthesias (21%), and prolongation of myelosuppression. Transient hyperbilirubinemia developed in 62% of treatment courses and was CsA-dose-dependent. Reversible azotemia occurred in three patients receiving concurrent treatment with potentially nephrotoxic antibiotics. Steady-state blood concentrations of CsA > or = 1,500 ng/mL were achieved in all patients receiving CI doses > or = 16 mg/kg/d. Mean plasma daunorubicin, but not daunorubicinol, levels were significantly elevated in patients who developed hyperbilirubinemia (P = .017). Twenty-six (62%) patients achieved a complete remission (CR) or restored chronic phase and three patients achieved a partial remission (PR) for an overall response rate of 69% (95% confidence interval, 54% to 84%). The response rate was higher in patients who developed hyperbilirubinemia (P = .001), whereas MDR phenotype did not influence response to treatment. Among five patients with MDR-positive leukemia, cellular mdr1 mRNA decreased (n = 1) or was absent from relapsed specimens (n = 4), while mdr1 RNA remained undetectable at relapse in two patients who were MDR-negative before treatment. CONCLUSION High doses of CsA, which achieve blood concentrations capable of reversing P-glycoprotein-mediated anthracycline resistance in vitro, can be incorporated into induction regimens with acceptable nonhematologic toxicity. Transient hyperbilirubinemia occurs commonly with CsA administration and may alter daunorubicin pharmacokinetics. Recommended doses of CsA for phase II and III trials are a load of 6 mg/kg and CI of 16 mg/kg/d.

scholarly journals Direct regulation of nacre, a zebrafish MITF homolog required for pigment cell formation, by the Wnt pathway

2000 ◽  
Vol 14 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Richard I. Dorsky ◽  
David W. Raible ◽  
Randall T. Moon
Keyword(s):  
Cell Differentiation ◽  
Binding Sites ◽  
Pigment Cell ◽  
Cell Formation ◽  
Dominant Negative ◽  
Reporter Construct ◽  
Cell Fates ◽  
Necessary And Sufficient

We have shown that Wnt signals are necessary and sufficient for neural crest cells to adopt pigment cell fates. nacre, a zebrafish homolog of MITF, is required for pigment cell differentiation. We isolated a promoter region of nacre that contains Tcf/Lef binding sites, which can mediate Wnt responsiveness. This promoter binds to zebrafish Lef1 protein in vitro, and a nacre reporter construct is strongly repressed by dominant-negative Tcf in melanoma cells. Mutation of Tcf/Lef sites abolishes Lef1 binding and reporter function in vivo. Wnt signaling therefore directly activatesnacre, which in turn leads to pigment cell differentiation.

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