Name: quantification of hypopigmentation activity in vitro
Uploaded: 2019-03-06T12:30:00
Description: Watch this Scientific Journal Video about Quantification of Hypopigmentation Activity In Vitro at JoVE.com

Dit werk werd gesteund door de Korea Instituut voor Planning en evaluatie voor technologie in voedsel, landbouw en bosbouw (IPET) via de Agri-dierziekte Technology Development Program, gefinancierd door het ministerie van landbouw, voedsel en plattelandsontwikkeling zaken (MAFRA ) (116159-02-2-WT011) en de School van de biowetenschappen en de biotechnologie voor BK21 PLUS, Universiteit van Korea.

1. bereiding van Medium, verbindingen en reagentia
<ol><li>B16F10 groeimedium volledig voor te bereiden. De aanvulling Dulbecco bewerkt Eagle's medium (DMEM) met 10% foetale runderserum (FBS) en 1% penicilline/streptomycine (PEST).<ol>
<li>Meng om 500 mL van volledige medium, 445 mL Dulbecco van gemodificeerde Eagle's medium (DMEM) met 50 mL FBS en 5 mL van de PEST in een gesteriliseerde 1 L-fles. Na het mengen zachtjes, filtreer het medium door een 0,2-µm fles-top-filter naar een nieuwe gesteriliseerde glazen fles en...

<ol>
	<li>Bonaventure, J., Domingues, M. J., Larue, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+and+molecular+mechanisms+controlling+the+migration+of+melanocytes+and+melanoma+cells.">Cellular and molecular mechanisms controlling the migration of melanocytes and melanoma cells.</a> Pigment Cell &amp; Melanoma Research. 26 (3), 316-325 (2013).</li><li>Brenner, M., Hearing, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+protective+role+of+melanin+against+UV+damage+in+human+skin.">The protective role of melanin against UV damage in human skin.</a> Photochemistry and Photobiology. 84 (3), 539-549 (2008).</li><li>Galvan, I., Solano, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Melanin+chemistry+and+the+ecology+of+stress.">Melanin chemistry and the ecology of stress.</a> Physiological and Biochemical Zoology. 88 (3), 352-355 (2015).</li><li>Burger, P., Landreau, A., Azoulay, S., Michel, T., Fernandez, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skin+whitening+cosmetics:+Feedback+and+challenges+in+the+development+of+natural+skin+lighteners.">Skin whitening cosmetics: Feedback and challenges in the development of natural skin lighteners.</a> Cosmetics. 3 (4), 36 (2016).</li><li>Cooksey, C. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+of+the+indirect+formation+of+the+catecholic+intermediate+substrate+responsible+for+the+autoactivation+kinetics+of+tyrosinase.">Evidence of the indirect formation of the catecholic intermediate substrate responsible for the autoactivation kinetics of tyrosinase.</a> Journal of Biological Chemistry. 272 (42), 26226-26235 (1997).</li><li>Ando, H., Kondoh, H., Ichihashi, M., Hearing, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Approaches+to+identify+inhibitors+of+melanin+biosynthesis+via+the+quality+control+of+tyrosinase.">Approaches to identify inhibitors of melanin biosynthesis via the quality control of tyrosinase.</a> Journal of Investigative Dermatology. 127 (4), 751-761 (2007).</li><li>Gillbro, J. M., Olsson, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+melanogenesis+and+mechanisms+of+skin-lightening+agents+-+existing+and+new+approaches.">The melanogenesis and mechanisms of skin-lightening agents - existing and new approaches.</a> International Journal of Cosmetic Science. 33 (3), 210-221 (2011).</li><li>Passeron, T., Coelho, S. G., Miyamura, Y., Takahashi, K., Hearing, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunohistochemistry+and+in+situ+hybridization+in+the+study+of+human+skin+melanocytes.">Immunohistochemistry and in situ hybridization in the study of human skin melanocytes.</a> Experimental Dermatology. 16 (3), 162-170 (2007).</li><li>Lee, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Momilactione+B+inhibits+protein+kinase+A+signaling+and+reduces+tyrosinase-related+proteins+1+and+2+expression+in+melanocytes.">Momilactione B inhibits protein kinase A signaling and reduces tyrosinase-related proteins 1 and 2 expression in melanocytes.</a> Biotechnology Letters. 34 (5), 805-812 (2012).</li><li>Jun, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual+inhibitions+of+lemon+balm+(Melissa+officinalis)+ethanolic+extract+on+melanogenesis+in+B16-F1+murine+melanocytes:+inhibition+of+tyrosinase+activity+and+its+gene+expression.">Dual inhibitions of lemon balm (Melissa officinalis) ethanolic extract on melanogenesis in B16-F1 murine melanocytes: inhibition of tyrosinase activity and its gene expression.</a> Food Science and Biotechnology. 20 (4), 1051-1059 (2011).</li><li>Jun, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=p-Coumaric+acid+inhibition+of+CREB+phosphorylation+reduces+cellular+melanogenesis.">p-Coumaric acid inhibition of CREB phosphorylation reduces cellular melanogenesis.</a> European Food Research and Technology. 235 (6), 1207-1211 (2012).</li><li>Jun, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual+inhibition+of+&#947;-oryzanol+on+cellular+melanogenesis:+inhibition+of+tyrosinase+activity+and+reduction+of+melanogenic+gene+expression+by+a+protein+kinase+a-dependent+mechanism.">Dual inhibition of &#947;-oryzanol on cellular melanogenesis: inhibition of tyrosinase activity and reduction of melanogenic gene expression by a protein kinase a-dependent mechanism.</a> Journal of Natural Products. 75 (10), 1706-1711 (2012).</li><li>Choi, Y. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+the+isoflavone+puerarin+and+its+glycosides+on+melanogenesis+in+B16+melanocytes.">Effects of the isoflavone puerarin and its glycosides on melanogenesis in B16 melanocytes.</a> European Food Research and Technology. 231 (1), 75-83 (2010).</li><li>Cho, B. R., Jun, H. J., Thach, T. T., Wu, C., Lee, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Betaine+reduces+cellular+melanin+content+via+suppression+of+microphthalmia-associated+transcription+factor+in+B16-F1+murine+melanocytes.">Betaine reduces cellular melanin content via suppression of microphthalmia-associated transcription factor in B16-F1 murine melanocytes.</a> Food Science and Biotechnology. 26 (5), 1391-1397 (2017).</li><li>Overwijk, W. W., Restifo, N. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=B16+as+a+mouse+model+for+human+melanoma.">B16 as a mouse model for human melanoma.</a> Current Protocols in Immunology. , (2001).</li><li>Virador, V. M., Kobayashi, N., Matsunaga, J., Hearing, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+standardized+protocol+for+assessing+regulators+of+pigmentation.">A standardized protocol for assessing regulators of pigmentation.</a> Analytical Biochemistry. 270 (2), 207-219 (1999).</li><li>D'Mello, S. A. N., Finlay, G. J., Baguley, B. C., Askarian-Amiri, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signaling+pathways+in+melanogenesis.">Signaling pathways in melanogenesis.</a> International Journal of Molecular Sciences. 17 (7), 1144 (2016).</li><li>Hou, L., Panthier, J. J., Arnheiter, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signaling+and+transcriptional+regulation+in+the+neural+crest-derived+melanocyte+lineage:+interactions+between+KIT+and+MITF.">Signaling and transcriptional regulation in the neural crest-derived melanocyte lineage: interactions between KIT and MITF.</a> Development. 127 (24), 5379-5389 (2000).</li><li>Hedley, S. J., Gawkrodger, D. J., Weetman, A. P., MacNeil, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#945;-MSH+and+melanogenesis+in+normal+human+adult+melanocytes.">&#945;-MSH and melanogenesis in normal human adult melanocytes.</a> Pigment Cell Research. 11 (1), 45-56 (1998).</li><li>Hu, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methodology+for+evaluation+of+melanin+content+and+production+of+pigment+cells+in+vitro.">Methodology for evaluation of melanin content and production of pigment cells in vitro.</a> Photochemistry and Photobiology. 84 (3), 645-649 (2008).</li><li>Carriel, V. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+histochemical+method+for+a+simultaneous+staining+of+melanin+and+collagen+fibers.">A novel histochemical method for a simultaneous staining of melanin and collagen fibers.</a> Journal of Histochemistry &amp; Cytochemistry. 59 (3), 270-277 (2011).</li></ol>

Wij presenteerden protocollen voor de beoordeling van de activiteit van de verdikking van de test verbindingen met behulp van gekweekte melanocyten. De representatieve resultaten toonde het effect van de verdikking van de Arbutine, een tyrosinase-remmer die geremd tyrosinase-activiteit en cellulaire melanine inhoud. Deze methoden worden veel gebruikt in anti-melanogenic activiteit onderzoek. Met behulp van deze tests, hebben we ook met succes verschillende bioactieve stoffen die melanogenesis remmende effecten op B16F10 ...

Melanine speelt een cruciale rol in de fysiologie, pathologie en toxicologie van verscheidene organen waaronder de huid, ogen en hersenen1. Belangrijkste functies van melanine zijn foto-screening en biochemische effecten. Melanine absorbeert nabij-infrarood en zichtbaar licht, alsmede ultraviolette (UV) straling, met verhoogde absorptie tarieven bij kortere golflengten van het licht; melanine beschermt dus weefsels tegen schade veroorzaakt door zichtbaar licht of UV straling2. Melanine is een antioxidant en heeft een affiniteit voor metalen en andere giftige chemische stoffen; het kan daarom weefsels beschermen tegen oxidatieve en chemische stress3. De overmatige productie van melanine veroorzaakt echter dermatologische problemen.
De kwantiteit en kwaliteit van melanine in de huid en iris zijn de belangrijkste determinanten van de kleur van de iris en de huid. Individuen kunnen hebben verschillende huid kleurvoorkeuren; enkele gunst gebruinde huid, terwijl anderen het voordeel van lichtere kleuren van de huid. Afhankelijk van deze consument profielen, zijn hypopigmentatie cosmetica ontwikkeld om te voldoen aan individuele markten voor favoriete huid kleuren4. Dienovereenkomstig, zijn studies van hypopigmentatie en anti-melanogenic activiteiten belangrijk, zowel wetenschappelijk als praktisch.
Melanogenesis is het complexe proces van melanine biosynthese door middel van een reeks van enzymatische en spontane chemische reacties in de melanocyten. Een melanocyt wordt omgeven door ongeveer 36 keratinocyten en melanocyten zijn de melanine synthese fabrieken die verspreiden van hun product aan naburige keratinocyten. In de huid, wordt de melanine geproduceerd en opgeslagen in het compartiment van de melanosomal van melanocyten getransporteerd naar naburige keratinocyten in de opperhuid via dendrites.
L-Tyrosine serveert de eerste substraat voor melanogenesis en het enzym tyrosinase katalyseert twee opeenvolgende reacties die L-tyrosine naar 3,4-dihydroxyphenylalanine (DOPA) en vervolgens naar dopaquinone converteren. Deze reacties zijn de snelheidslimieten stap in melanogenesis5,6. Dienovereenkomstig, hypopigmentatie activiteit kan eerst worden gemeten door cellulaire tyrosinase-activiteit rechtstreeks te bepalen. Om dit te doen, melanocyt extracten met tyrosinase worden geïncubeerd met DOPA en de dopaquinone geproduceerd in de monsters kan worden gemeten door spectrofotometrie op 475 nm. De waarden zijn genormaliseerd door de concentraties van de eiwitten van de monsters, alsmede stoffen met hypopigmentatie activiteit resultaat in minder vorming van de dopaquinone vergeleken met besturingselementen.
Ten tweede, hypopigmentatie activiteit kan worden gekwantificeerd door het meten van melanine in gekweekte melanocyten direct. Na behandeling van cellen met het testmateriaal, melanine wordt gewonnen onder alkalische omstandigheden en de melanine inhoud wordt gekwantificeerd door spectrofotometrie bij 400 nm. Een verdikking agent zal resulteren in een lagere melanine inhoud dan de besturingselementen7.
Tot slot, de verdikking activiteit kan worden gekwantificeerd door Fontana-Masson melanine kleuring en latere beeldanalyse. Melanine korrels Verlaag ammoniak-zilvernitraat aan een zwarte metalen zichtbaarheidsstatus in Fontana-Masson kleuring, en de zwarte gebieden van cellen in de microscopische beelden vertegenwoordigen de hoeveelheid melanine.
Een verdikking agent geeft meestal consistente en vergelijkbare resultaten met deze drie methoden, die bevestigt dat de activiteit van de stof geldig is. Anderzijds kan het zinvol zijn om te meten de uitdrukking van essentiële genen en proteïnen in melanogenesis naar aanleiding van een teststof te onderzoeken van hypopigmentatie activiteit. Naast tyrosinase zijn tyrosinase-gerelateerde eiwitten (TRP-1) en dopachrome tautomerase (TRP-2) essentiële enzymen in melanogenesis8. De transcriptie factor microphthalmia-geassocieerde transcriptiefactor (MITF) is een meester regelgever in melanogenesis en kwantificering van de gene/proteïne expressie niveaus of een promotor activiteit assay kan ook worden gebruikt om te beoordelen van hypopigmentatie activiteit.

<table>
	<tbody>
		<tr>
			<td>3,4-Dihydroxy-l-phenylalanine</td>
			<td>Sigma</td>
			<td>D9628</td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium hydroxide solution</td>
			<td>Sigma</td>
			<td>#320145</td>
			<td></td>
		</tr>
		<tr>
			<td>Arbutin</td>
			<td>Fluka</td>
			<td>#10960</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>HyClone</td>
			<td>SH30243.01</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>HyClone</td>
			<td>SH30084.03</td>
			<td></td>
		</tr>
		<tr>
			<td>Formalin</td>
			<td>Yakuri Pure Chemicals</td>
			<td>#16223</td>
			<td>37%</td>
		</tr>
		<tr>
			<td>Gold chloride</td>
			<td>American MasterTech</td>
			<td>AHG0226</td>
			<td>0.10%</td>
		</tr>
		<tr>
			<td>HCl</td>
			<td>Samchun chemical</td>
			<td>H0255</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Bio basic Canada Inc.</td>
			<td>PB0440</td>
			<td></td>
		</tr>
		<tr>
			<td>KH2PO4</td>
			<td>Sigma</td>
			<td>#60218</td>
			<td></td>
		</tr>
		<tr>
			<td>Na2HPO4</td>
			<td>J.T.Baker</td>
			<td>#3817-01</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Duksan pure chemicals</td>
			<td>#81</td>
			<td></td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>Sigma</td>
			<td>655104</td>
			<td></td>
		</tr>
		<tr>
			<td>Nuclear fast red</td>
			<td>Merck</td>
			<td>100121</td>
			<td>Nuclear fast red 0.1% in 5% aluminum sulfate.</td>
		</tr>
		<tr>
			<td>Penicillin and streptomycin solution</td>
			<td>HyClone</td>
			<td>SV30010</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver nitrate</td>
			<td>Duksan Pure Chemicals</td>
			<td>#900</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium phosphate dibasic (Na2HPO4)</td>
			<td>J.T. Baker</td>
			<td>#3817-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium phosphate monobasic (Na2HPO4)</td>
			<td>Sigma</td>
			<td>S5011</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium thiosulfate pentahydrate</td>
			<td>Duksan Pure Chemicals</td>
			<td>#2163</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris(hydroxymethyl)aminomethane</td>
			<td>Bio Basic Canada</td>
			<td>TB0196</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Union Carbide</td>
			<td>T8787</td>
			<td></td>
		</tr>
		<tr>
			<td>Tyrosinase from mushroom</td>
			<td>Sigma</td>
			<td>T3824</td>
			<td>25 KU</td>
		</tr>
	</tbody>
</table>

quantification of hypopigmentation activity in vitro

Deze studie presenteert laboratoriumtechnieken voor de kwantificering van hypopigmentatie activiteit in vitro. Melanine, de grote pigment in de melanocyten, wordt gesynthetiseerd in reactie op meerdere factoren voor cellulaire en milieu. Melanine beschermt de huidcellen tegen ultraviolet schade, maar heeft ook biofysische en biochemische functies. Buitensporige productie of ophoping van melanine in de melanocyten kan leiden tot dermatologische problemen, zoals sproeten, donkere vlekken, melasma en mollen. Daarom is de controle van melanogenesis met hypopigmentatie agenten is belangrijk bij personen met klinische en cosmetische behoeften. Melanine is hoofdzakelijk gesynthetiseerd in de melanosomes van melanocyten in een complexe biochemische proces genaamd melanogenesis, die wordt beïnvloed door Extrinsieke en intrinsieke factoren, zoals hormonen, ontsteking, leeftijd en blootstelling aan ultraviolet licht. We beschrijven drie methoden om te bepalen van de activiteit van de verdikking van chemicaliën of natuurlijke stoffen in de melanocyten: meting van de 1) cellulaire tyrosinase-activiteit 2) melanine inhoud, en 3) kleuring en kwantificering cellulaire melanine met afbeelding analyse.
In melanogenesis katalyseert tyrosinase de snelheidslimieten stap dat L-tyrosine naar 3,4-dihydroxyphenylalanine (levodopa) en vervolgens naar dopaquinone converteert. Daarom is de remming van tyrosinase een primaire hypopigmentatie mechanisme. In gekweekte melanocyten, kan tyrosinase-activiteit worden gekwantificeerd door levodopa als een substraat toe te voegen en het meten van de dopaquinone productie door spectrofotometrie. Melanogenesis kan ook worden gemeten door het kwantificeren van de melanine inhoud. De melanine bevattende cellulaire fractie wordt geëxtraheerd met NaOH en melanine spectrophotometrically wordt gekwantificeerd. Tot slot kan de melanine inhoud worden gekwantificeerd door beeldanalyse na Fontana-Masson kleuring van melanine. Hoewel de resultaten van deze in-vitrotests kunnen niet altijd worden gereproduceerd in de menselijke huid, worden deze methoden veel gebruikt in melanogenesis onderzoek, met name als de eerste stap om te identificeren van potentiële hypopigmentatie activiteit. Deze methoden kunnen ook worden gebruikt ter beoordeling van de melanocyt activiteit, groei en differentiatie. Consistente resultaten met de drie verschillende methoden zorgen de geldigheid van de effecten.

Representatieve resultaten voor de activiteit van de verdikking van de Arbutine, een anti-melanogenic samengestelde, in B16F10 melanocyten staan hieronder. Figuur 1A blijkt dat Arbutine sterk onderdrukt de cellulaire tyrosinase-activiteit in vergelijking met de controle van voertuig-behandeld. Ook was de melanine inhoud van cellen gestimuleerd met Arbutine aanzienlijk verminderd in vergelijking met de besturingselementen (figuur 1B</stron...

Watch this Scientific Journal Video about Quantification of Hypopigmentation Activity In Vitro at JoVE.com

Quantification of Hypopigmentation Activity In Vitro

We beschrijven drie experimentele methoden voor de evaluatie van de activiteit van de verdikking van chemische stoffen in vitro: kwantificering van 1) cellulaire tyrosinase-activiteit en 2) melanine inhoud, en 3) meting van melanine door cellulaire melanine kleuring en beeld-analyse.

Kwantificering van hypopigmentatie activiteit In Vitro

This study presents laboratory methods for the quantification of hypopigmentation activity in vitro. Melanin, the major pigment in melanocytes, is ...

Deze methode kan nuttig zijn bij de ontwikkeling van functionele cosmetica en huidagent met anti-melanogene activiteiten. Het is er om uit te voeren en het resultaat kan snel worden verkregen. Bovendien kan deze methode nuttig zijn voor onderzoekers, die de effecten of de verbindingen willen identificeren of onderzoeken of de antimelanogene of promelanogene activiteiten willen onderzoeken.Om te meten tyrosinase activiteit beginnen met het zaaien van B16-F10 Melaniciden op een vijf keer 10 tot de vierde cellen per put van een 24 put plaat concentratie in volledig medium gedurende 24 uur in een celcultuur incubator. De volgende dag, vervang de supernatant in elke put met DMEM aangevuld met vers bereide test verbinding en remmer controle of een negatieve controle en terug de plaat naar de incubator voor nog eens 72 uur. Spoel aan het einde van de behandeling de putten twee keer af met 300 microliter koude pbs per put en leg de plaat op ijs.Voeg vervolgens 300 microliter lysebuffer toe aan elke put met behulp van een celschraper om de celkrassen na vijf minuten te verzamelen. Breng de resulterende celdeeltjessuspensies over op individuele 1,5 milliliter microcentrifugebuizen. En homogeniseren de lysates drie keer gedurende twee seconden op 14, 500 rpm op ijs om de intercellulaire Tyrosinase release.Pellet het celpuin door centrifugatie en breng de supernatants over naar individuele 1,5 milliliter centrifugebuizen op ijs. Wijs 70 microliter van elke supernatant toe aan afzonderlijke putten van een duidelijke 96 put polystyreen microplaat en voeg 140 microliters van Tyrosinase substraatoplossing toe aan elke put van supernatant. Schudden van de plaat zacht om de put inhoud te mengen.Dan incubeer de plaat op 37 graden celsius voor twee uur. En meet tyrosinase activiteit op 475 nanometer op een microplate lezer. Om het melaninegehalte van de cellen te meten na het verzamelen van het lysaat van de behandelde cellen zoals aangetoond.Verzamel de lysates door centrifugatie en breng de supernatants over naar nieuwe buizen. Voeg 300 microliters van een normale natriumhydroxide toe aan elke pellet voor een incubatie van een uur bij 60 graden Celsius. Gevolgd door centrifugatie van de opgeloste celsuspensies.Breng vervolgens 200 microliters van de supernatants over naar elke put van een 96 putplaat. En meet de melanine inhoud op een microplate lezer op een golflengte van 400 nanometer. Voor Fontana-Masson Kleuring, was de behandelde cellen twee keer met 300 microliters koude pbs en bevestig de cellen met 200 microliters van 10% formaline gedurende een uur bij vier graden Celsius.Spoel de dikke cellen met gedestilleerd water en voeg 200 microliters van 58 tot 68 graden Celsius Ammoniacal zilver werkende oplossing aan elke put. Voor een uur incubatie bij 37 graden Celsius of totdat de cellen geelbruin van kleur. Spoel de gekleurde cellen met gedestilleerd water, gevolgd door twee minuten incubatie in 0,1%goudchloride bij kamertemperatuur.Spoel de met goudchloride behandelde cellen af met gedestilleerd water en voeg 200 microliter natriumthiosulfaatoplossing toe aan de cellen. Na twee minuten spoel de cellen weer. En label de cellen met 200 microliters van kernsnel rood per put gedurende vijf minuten.Was vervolgens de gekleurde cellen met leidingwater voordat beeldvorming onder een lichtmicroscoop. Open voor drempelanalyse de afbeeldingen in afbeelding J en selecteer afbeelding, aanpassen en Kleurdrempel. Als u het gebied wilt meten dat is bevlekt met Fontana Masson, stelt u de helderheidsparameterbalk in op nul en past u de helderheid aan op het punt waarop alle zwarte of bruine gekleurde cellen zijn opgenomen.Selecteer Deeltjes analyseren en analyseren en schakel het selectievakje samenvatten in het venster Deeltjes analyseren en klik vervolgens op oke om een samenvatting van de resultaten te verkrijgen en de gegevens in een spreadsheet te kopiëren en plakken. Arbutin behandeling onderdrukt de cellulaire Tyrosinase activiteit aanzienlijk in vergelijking met de controle voertuig behandelde cellen. Ook het melaninegehalte van cellen gestimuleerd met Arbutin is aanzienlijk verminderd in vergelijking met de controles.Hoewel de cellen morfologisch vergelijkbaar zijn tussen behandelingsgroepen, vermindert Arbutin het gebied van zwart pigment in vergelijking met de controle behandelde cellen. Deze methode is handig voor activiteiten screening met behulp van onze samengestelde bibliotheek. Er zijn meer dan honderden monsters die snel getest moeten worden.Bovendien kan deze methode ook worden gebruikt om het mechanisme met melanogenese te onderzoeken. Nadat de bioactieve kandidaten verbindingen zijn geïdentificeerd, voor hun getuigenis van de studie van biologische mechanismen of commerciële toepassingen.

quantification-of-hypopigmentation-activity-in-vitro

Research

JoVE Journal

Biochemistry

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

Bacteria are frequently exposed to environmental changes, such as alterations in pH, temperature, redox status, light exposure or mechanical force. Many of these conditions cause protein unfolding in the cell and have detrimental impact on the survival of the organism. A group of unrelated, stress-specific molecular chaperones have been shown to play essential roles in the survival of these stress conditions. While fully folded and chaperone-inactive before stress, these proteins rapidly unfold and become chaperone-active under specific stress conditions. Once activated, these conditionally disordered chaperones bind to a large number of different aggregation-prone proteins, prevent their aggregation and either directly or indirectly facilitate protein refolding upon return to non-stress conditions. The primary approach for gaining a more detailed understanding about the mechanism of their activation and client recognition involves the purification and subsequent characterization of these proteins using in vitro chaperone assays. Follow-up in vivo stress assays are absolutely essential to independently confirm the obtained in vitro results.
This protocol describes in vitro and in vivo methods to characterize the chaperone activity of E. coli HdeB, an acid-activated chaperone. Light scattering measurements were used as a convenient read-out for HdeB&#39;s capacity to prevent acid-induced aggregation of an established model client protein, MDH, in vitro. Analytical ultracentrifugation experiments were applied to reveal complex formation between HdeB and its client protein LDH, to shed light into the fate of client proteins upon their return to non-stress conditions. Enzymatic activity assays of the client proteins were conducted to monitor the effects of HdeB on pH-induced client inactivation and reactivation. Finally, survival studies were used to monitor the influence of HdeB&#39;s chaperone function in vivo.

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo

This study describes biophysical, biochemical and molecular techniques to characterize the chaperone activity of Escherichia coli HdeB under acidic pH conditions. These methods have been successfully applied for other acid-protective chaperones such as HdeA and can be modified to work for other chaperones and stress conditions.

Detectie van de pH-afhankelijke activiteit van<em&gt; Escherichia coli</em&gt; Chaperone HdeB<em&gt; In Vitro</em&gt; en<em&gt; In Vivo</em

Bacteria are frequently exposed to environmental changes, such as alterations in pH, temperature, redox status, light exposure or mechanical force. Many ...

Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli

Transfer RNA (tRNA) is an essential part of the translational machinery in any organism. tRNAs bind and transfer amino acids to the translating ribosome. The relative levels of different tRNAs, and the ratio of aminoacylated tRNA to total tRNA, known as the charging level, are important factors in determining the accuracy and speed of translation. Therefore, the abundance and charging levels of tRNAs are important variables to measure when studying protein synthesis, for example under various stress conditions. Here, we describe a method for harvesting tRNA and directly measuring both the relative abundance and the absolute charging level of specific tRNA species in Escherichia coli. The tRNA is harvested in such a way that the labile bond between the tRNA and its amino acid is preserved. The RNA is then subjected to gel electrophoresis and Northern blotting, which results in separation of the charged and uncharged tRNAs. The levels of specific tRNAs in different samples can be compared due to the addition of spike-in cells for normalization. Prior to RNA purification, we add 5% of E. coli cells that overproduce the rare tRNAselC to each sample. The amount of the tRNA species of interest in a sample is then normalized to the amount of tRNAselC in the same sample. Addition of spike-in cells prior to RNA purification has the advantage over addition of purified spike-in RNAs that it also accounts for any differences in cell lysis efficiency between samples.

Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli

Here we present a method for directly measuring transfer RNA charging levels from purified Escherichia coli RNA as well as a way to compare relative levels of transfer RNA, or any other short RNA, across different samples based on the addition of spike-in cells expressing a reference gene.

Kwantificering van de overvloed en het opladen van de niveaus van overdracht RNAs in Escherichia coli

Transfer RNA (tRNA) is an essential part of the translational machinery in any organism. tRNAs bind and transfer amino acids to the translating ribosome. ...

Mapping Metabolism: Monitoring Lactate Dehydrogenase Activity Directly in Tissue

Mapping enzymatic activity in space and time is critical for understanding the molecular basis of cell behavior in normal tissue and disease. In situ metabolic activity assays can provide information about the spatial distribution of metabolic activity within a tissue. We provide here a detailed protocol for monitoring the activity of the enzyme lactate dehydrogenase directly in tissue samples. Lactate dehydrogenase is an important determinant of whether consumed glucose will be converted to energy via aerobic or anaerobic glycolysis. A solution containing lactate and NAD is provided to a frozen tissue section. Cells with high lactate dehydrogenase activity will convert the provided lactate to pyruvate, while simultaneously converting provided nicotinamide adenine dinucleotide (NAD) to NADH and a proton, which can be detected based on the reduction of nitrotetrazolium blue to formazan, which is visualized as a blue precipitate. We describe a detailed protocol for monitoring lactate dehydrogenase activity in mouse skin. Applying this protocol, we found that lactate dehydrogenase activity is high in the quiescent hair follicle stem cells within the skin. Applying the protocol to cultured mouse embryonic stem cells revealed higher staining in cultured embryonic stem cells than mouse embryonic fibroblasts. Analysis of freshly isolated mouse aorta revealed staining in smooth muscle cells perpendicular to the aorta. The methodology provided can be used to spatially map the activity of enzymes that generate a proton in frozen or fresh tissue.

We describe a protocol for mapping the spatial distribution of enzymatic activity for enzymes that generate nicotinatmide adenine dinucleotide phosphate (NAD(P)H) + H+ directly in tissue samples.

Toewijzing metabolisme: Bewakingsactiviteit lactaat Dehydrogenase rechtstreeks in weefsel

Mapping enzymatic activity in space and time is critical for understanding the molecular basis of cell behavior in normal tissue and disease. In situ ...

An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity

N6-isopentenyladenosine RNA modifications are functionally diverse and highly conserved among prokaryotes and eukaryotes. One of the most highly conserved N6-isopentenyladenosine modifications occurs at the A37 position in a subset of tRNAs. This modification improves translation efficiency and fidelity by increasing the affinity of the tRNA for the ribosome. Mutation of enzymes responsible for this modification in eukaryotes are associated with several disease states, including mitochondrial dysfunction and cancer. Therefore, understanding the substrate specificity and biochemical activities of these enzymes is important for understanding of normal and pathologic eukaryotic biology. A diverse array of methods has been employed to characterize i6A modifications. Herein is described a direct approach for the detection of isopentenylation by Mod5. This method utilizes incubation of RNAs with a recombinant isopentenyl transferase, followed by RNase T1 digestion, and 1-dimensional gel electrophoresis analysis to detect i6A modifications. In addition, the potential adaptability of this protocol to characterize other RNA-modifying enzymes is discussed.

An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity

Here, we describe a protocol for the biochemical characterization of the yeast RNA-modifying enzyme, Mod5, and discuss how this protocol could be applied to other RNA-modifying enzymes.

Een In Vitro Assay tRNA-Isopentenyl Transferase activiteit detecteren

N6-isopentenyladenosine RNA modifications are functionally diverse and highly conserved among prokaryotes and eukaryotes. One of the most highly conserved ...

Calibration-free In Vitro Quantification of Protein Homo-oligomerization Using Commercial Instrumentation and Free, Open Source Brightness Analysis Software

Number and brightness is a calibration-free fluorescence fluctuation spectroscopy (FFS) technique for detecting protein homo-oligomerization. It can be employed using a conventional confocal microscope equipped with digital detectors. A protocol for the use of the technique in vitro is shown by means of a use case where number and brightness can be seen to accurately quantify the oligomeric state of mVenus-labelled FKBP12F36V before and after the addition of the dimerizing drug AP20187. The importance of using the correct microscope acquisition parameters and the correct data preprocessing and analysis methods are discussed. In particular, the importance of the choice of photobleaching correction is stressed. This inexpensive method can be employed to study protein-protein interactions in many biological contexts.

Calibration-free In Vitro Quantification of Protein Homo-oligomerization Using Commercial Instrumentation and Free, Open Source Brightness Analysis Software

This protocol describes a calibration-free approach for quantifying protein homo-oligomerization in vitro based on fluorescence fluctuation spectroscopy using commercial light scanning microscopy. The correct acquisition settings and analysis methods are shown.

Kalibratie-gratis In Vitro kwantificering van eiwit Homo-oligomerisatie met behulp van commerciële instrumentatie en Software van de analyse van de helderheid van gratis, Open Source

Number and brightness is a calibration-free fluorescence fluctuation spectroscopy (FFS) technique for detecting protein homo-oligomerization. It can be ...

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

Mitochondria play the most prominent roles in cellular metabolism by producing ATP through oxidative phosphorylation and regulating a variety of physiological processes. Mitochondrial dysfunction is a primary cause of a number of metabolic and neurodegenerative diseases. Intact mitochondria are critical for their proper functioning. The enzyme citrate synthase is localized in the mitochondrial matrix and thus can be used as a quantitative enzyme marker of intact mitochondrial mass. Given that many molecules and pathways that have important functions in mitochondria are highly conserved between humans and Drosophila, and that an array of powerful genetic tools are available in Drosophila, Drosophila serves as a good model system for studying mitochondrial function. Here, we present a protocol for fast and simple measurement of citrate synthase activity in tissue homogenate from adult flies without isolating mitochondria. This protocol is also suitable for measuring citrate synthase activity in larvae, cultured cells, and mammalian tissues.

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

We present a protocol for a colorimetric assay of citrate synthase activity for quantification of intact mitochondrial mass in Drosophila tissue homogenates.

Een colorimetrische assay van citraat synthase activiteit in Drosophila melanogaster

Mitochondria play the most prominent roles in cellular metabolism by producing ATP through oxidative phosphorylation and regulating a variety of ...

Synthesis of a Deuterated Standard for the Quantification of 2-Arachidonoylglycerol in Caenorhabditis elegans

This work presents a method to prepare an analytical standard to analyze 2-arachidonoyl glycerol (2-AG) qualitatively and quantitatively by liquid chromatography-electrospray Ionization-tandem mass spectrometry (LC-ESI-MS/MS). Endocannabinoids are conserved lipid mediators that regulate multiple biological processes in a variety of organisms. In C. elegans, 2-AG has been found to possess different roles, including modulation of dauer formation and cholesterol metabolism. This report describes a method to overcome the difficulties associated with the costs and stability of deuterated standards required for 2-AG quantification. The procedure for the synthesis of the standard is simple and can be performed in any laboratory, without the need for organic synthesis expertise or special equipment. In addition, a modification of Folch&#39;s method to extract the deuterated standard from C. elegans culture is described. Finally, a quantitative and analytic method to detect 2-AG using the stable isotopically labeled analog 1-AG-d5 is described, which provides reliable results in a fast-chromatographic run. The procedure is useful for studying the multiple roles of 2-AG in C. elegans while also being applicable to other studies of metabolites in different organisms.

Synthesis of a Deuterated Standard for the Quantification of 2-Arachidonoylglycerol in Caenorhabditis elegans

This work describes a robust and straightforward method to detect and quantify the endocannabinoid 2-arachidonoylglycerol (2-AG) in C. elegans. An analytical deuterated standard us prepared and used for the quantification of 2-AG by isotopic dilution and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS).

Synthese van een Deuterated norm voor de kwantificering van 2-arachidonoylglycerol in Caenorhabditis elegans

This work presents a method to prepare an analytical standard to analyze 2-arachidonoyl glycerol (2-AG) qualitatively and quantitatively by liquid ...

Quantification of Protein Interaction Network Dynamics using Multiplexed Co-Immunoprecipitation

Dynamic protein-protein interactions control cellular behavior, from motility to DNA replication to signal transduction. However, monitoring dynamic interactions among multiple proteins in a protein interaction network is technically difficult. Here, we present a protocol for Quantitative Multiplex Immunoprecipitation (QMI), which allows quantitative assessment of fold changes in protein interactions based on relative fluorescence measurements of Proteins in Shared Complexes detected by Exposed Surface epitopes (PiSCES). In QMI, protein complexes from cell lysates are immunoprecipitated onto microspheres, and then probed with a labeled antibody for a different protein in order to quantify the abundance of PiSCES. Immunoprecipitation antibodies are conjugated to different MagBead spectral regions, which allows a flow cytometer to differentiate multiple parallel immunoprecipitations and simultaneously quantify the amount of probe antibody associated with each. QMI does not require genetic tagging and can be performed using minimal biomaterial compared to other immunoprecipitation methods. QMI can be adapted for any defined group of interacting proteins, and has thus far been used to characterize signaling networks in T cells and neuronal glutamate synapses. Results have led to new hypothesis generation with potential diagnostic and therapeutic applications. This protocol includes instructions to perform QMI, from the initial antibody panel selection through to running assays and analyzing data. The initial assembly of a QMI assay involves screening antibodies to generate a panel, and empirically determining an appropriate lysis buffer. The subsequent reagent preparation includes covalently coupling immunoprecipitation antibodies to MagBeads, and biotinylating probe antibodies so they can be labeled by a streptavidin-conjugated fluorophore. To run the assay, lysate is mixed with MagBeads overnight, and then beads are divided and incubated with different probe antibodies, and then a fluorophore label, and read by flow cytometry. Two statistical tests are performed to identify PiSCES that differ significantly between experimental conditions, and results are visualized using heatmaps or node-edge diagrams.

Quantitative Multiplex Immunoprecipitation (QMI) uses flow cytometry for sensitive detection of differences in the abundance of targeted protein-protein interactions between two samples. QMI can be performed using a small amount of biomaterial, does not require genetically engineered tags, and can be adapted for any previously defined protein interaction network.

Kwantificering van eiwit interactie netwerk dynamiek met Multiplexed co-immunoprecipitatie

Dynamic protein-protein interactions control cellular behavior, from motility to DNA replication to signal transduction. However, monitoring dynamic ...

Quantification of Coenzyme A in Cells and Tissues

Emerging research has revealed that the cellular coenzyme A (CoA) supply can become limiting with a detrimental impact on growth, metabolism and survival. Measurement of cellular CoA is a challenge due to its relatively low abundance and the dynamic conversion of free CoA to CoA thioesters that, in turn, participate in numerous metabolic reactions. A method is described that navigates through potential pitfalls during sample preparation to yield an assay with a broad linear range of detection that is suitable for use in many biomedical laboratories.

This method describes sample preparation from cultured cells and animal tissues, extraction and derivatization of coenzyme A in the samples, followed by high pressure liquid chromatography for purification and quantification of the derivatized coenzyme A by absorbance or fluorescence detection.

Kwantificering van co-enzym A in cellen en weefsels

Emerging research has revealed that the cellular coenzyme A (CoA) supply can become limiting with a detrimental impact on growth, metabolism and survival. ...

High-throughput kwantificering van de synthese en distributie van mtDNA

High-Throughput Image-Based Quantification of Mitochondrial DNA Synthesis and Distribution

The vast majority of cellular processes require a continuous supply of energy, the most common carrier of which is the ATP molecule. Eukaryotic cells produce most of their ATP in the mitochondria by oxidative phosphorylation. Mitochondria are unique organelles because they have their own genome that is replicated and passed on to the next generation of cells. In contrast to the nuclear genome, there are multiple copies of the mitochondrial genome in the cell. The detailed study of the mechanisms responsible for the replication, repair, and maintenance of the mitochondrial genome is essential for understanding the proper functioning of mitochondria and whole cells under both normal and disease conditions. Here, a method that allows the high-throughput quantification of the synthesis and distribution of mitochondrial DNA (mtDNA) in human cells cultured in vitro is presented. This approach is based on the immunofluorescence detection of actively synthesized DNA molecules labeled by 5-bromo-2'-deoxyuridine (BrdU) incorporation and the concurrent detection of all the mtDNA molecules with anti-DNA antibodies. Additionally, the mitochondria are visualized with specific dyes or antibodies. The culturing of cells in a multi-well format and the utilization of an automated fluorescence microscope make it easier to study the dynamics of mtDNA and the morphology of mitochondria under a variety of experimental conditions in a relatively short time.

Auteur in de schijnwerpers: high-throughput beeldgebaseerde kwantificering van mitochondriale DNA-synthese en -distributie  

A procedure for studying the dynamics of mitochondrial DNA (mtDNA) metabolism in cells using a multi-well plate format and automated immunofluorescence imaging to detect and quantify mtDNA synthesis and distribution is described. This can be further used to investigate the effects of various inhibitors, cellular stresses, and gene silencing on mtDNA metabolism.

High-throughput image-based kwantificering van mitochondriale DNA-synthese en -distributie

The vast majority of cellular processes require a continuous supply of energy, the most common carrier of which is the ATP molecule. Eukaryotic cells ...