To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reag...To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reagent, iron chelating agent, neuromelanin and dopamine melanin. We investigated the changes in expression of nine oxidative stress-related genes and proteins. The levels of mRNAs for heme-oxygenase-1 and glutathione S-transferase-ml were significantly reduced in SK-N-SH cells exposed to oxidative stress, and increased in glial cells treated with deferoxamine. These results revealed that SK-N-SH neurons react sensitively to oxidative stress, which implies different outcomes between these two types of cells in the substantia nigra. Moreover, the influences of neuromelanin and dopamine melanin on cell function are varied, and dopamine melanin is not a good model for neuromelanin.展开更多
Nigella sativa L.seeds have been traditionally utilized in Chinese folk medicine for centuries to treat vitiligo.This study revealed that the ethanolic extract of Nigella sativa L.(HZC)enhances melanogenesis and mitig...Nigella sativa L.seeds have been traditionally utilized in Chinese folk medicine for centuries to treat vitiligo.This study revealed that the ethanolic extract of Nigella sativa L.(HZC)enhances melanogenesis and mitigates oxidative stress-induced cellular senescence and dysfunction in melanocytes.In accordance with established protocols,the ethanol fraction from Nigella sativa L.seeds was extracted,concentrated,and lyophilized to evaluate its herbal effects via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assays,tyrosinase activity evaluation,measurement of cellular melanin contents,scratch assays,senescence-associatedβ-galactosidase(SA-β-gal)staining,enzyme-linked immunosorbent assay(ELISA),and Western blot analysis for expression profiling of experimentally relevant proteins.The results indicated that HZC significantly enhanced tyrosinase activity and melanin content while notably increasing the protein expression levels of Tyr,Mitf,and gp100 in B16F10 cells.Furthermore,HZC effectively mitigated oxidative stress-induced cellular senescence,improved melanocyte condition,and rectified various functional impairments associated with melanocyte dysfunction.These findings suggest that HZC increases melanin synthesis in melanocytes through the activation of the MAPK,PKA,and Wnt signaling pathways.In addition,HZC attenuates oxidative damage induced by H2O2 therapy by activating the nuclear factor E2-related factor 2-antioxidant response element(Nrf2-ARE)pathway and enhancing the activity of downstream antioxidant enzymes,thus preventing premature senescence and dysfunction in melanocytes.展开更多
Hair coloring has emerged as an integral part of the cosmetic industry,particularly in response to the increasing global aging phenomenon.The natural melanin analog,polydopamine(PDA),has garnered considerable attentio...Hair coloring has emerged as an integral part of the cosmetic industry,particularly in response to the increasing global aging phenomenon.The natural melanin analog,polydopamine(PDA),has garnered considerable attention as an eco-friendly hair dye,and several kinds of polymerization ways of dopamine(DA)have been proposed including alkali catalysis,metal ion catalysis,strong oxidants,and enzyme-mediated oxidation reactions and polymerizations.Yet the controllability of polymerization and potential toxicity of involved metal ions are still in question.Inspired by the photoprotective mechanism in human skin,we have developed the melanin-inspired hair dyeing strategy that allowed for the in situ oxidative polymerization of DA under ultraviolet(UV)light.This polymerization was triggered by photobase generators(PBGs),a class of compounds that produced organic bases upon UV and sunlight irradiation.The resulting hair showed an adjustable color from light brown to black by tuning the ratio of DA and PBG(DA@PBG),the concentration of DA,and light exposure time.The dyed hairs showed excellent washing resistance and superior anti-static properties.Furthermore,Hair Color Spray DA@PBG also demonstrated a desirable hair dyeing effect and excellent biosecurity by simply spraying it on the hair under sunlight.This novel sunlight-induced method provided a new direction towards the preparation of natural hair dyes and could promote the development of green and safe hair dyes in colorful and brilliant artistic-grade hair coloring.展开更多
Objective:Tyrosinase is the rate-limiting enzyme in the generation of melanin.The feline tyrosinase mutation,G302R,confers temperature-sensitive loss of function,resulting in the familiar Siamese cat phenotype.Crystal...Objective:Tyrosinase is the rate-limiting enzyme in the generation of melanin.The feline tyrosinase mutation,G302R,confers temperature-sensitive loss of function,resulting in the familiar Siamese cat phenotype.Crystal or cryoEM structures are elusive for any mammalian tyrosinase to date.Protein misfolding is suggested as a basis for phenotypes resulting frommutant tyrosinases,but this hypothesis needs structural confirmation.Our objective for this study is to confirm misfolding of mutant tyrosinase as a basis for temperature-sensitive phenotypes compared to catalytic dysfunction that may be responsible for other tyrosinase mutant breed phenotypes.Methods:We have employed AlphaFold3 to compare structural alignments of four well-characterized feline tyrosinase mutations to wild type(WT)feline tyrosinase;SiameseG302R,Burmese G227W,Mocha delI274-L312+2aa,andAlbino del401-529 lacking the transmembrane and C-terminus domains.Results:The manifestations of the bulkier side chains of the Siamese positively charged arginine(R)and the Burmese hydrophobic tryptophan(W)are evident locally.But interestingly,the major differences between the structures lie in the usually ignored signal peptide(SP)regions of each mutant.As the maturation of the nascent tyrosinase peptide is highly dependent on accurate and early cleavage of the SP,we hypothesize these structural anomaliesmay formthe basis formisfolded or truncated final enzyme forms,leading to the observed phenotypes seen in these cats.Conclusions:We have identified enzyme dysfunction and protein misfolding as separate mechanisms for feline coat phenotypes resulting from tyrosinase mutations.展开更多
Microorganisms inhabiting soils contaminated with heavy metals produce melanin,a dark brown pigment,as a survival strategy.In this study,a melanin-producing bacterium,Acinetobacter sp.ME1,with heavy metal tolerance an...Microorganisms inhabiting soils contaminated with heavy metals produce melanin,a dark brown pigment,as a survival strategy.In this study,a melanin-producing bacterium,Acinetobacter sp.ME1,with heavy metal tolerance and plant growth-promoting traits,was isolated from abandoned mine soil.Strain ME1 exhibited growth at concentrations of Zn up to 250 mg/L,Cd and Pb up to 100 mg/L,and Cr up to 50 mg/L.It had the ability to produce the plant hormone indole-3-acetic acid and siderophores along with 1-aminocyclopropane-1-carboxylic acid deaminase and protease activities.Additionally,it showed antioxidant activity,including catalase and 2,2-diphenyl-1-picryhydrazyl(DPPH)scavenging activities.The optimal conditions for melanin production by ME1 were a pH of 7 and a temperature of 35℃.At 1000 mg/L,ME1-extracted melanin exhibited DPPH radical scavenging activity of(25.040±0.007)%,a sun protection factor of 15.200±0.260,and 19.6%antibacterial activity against the plant pathogen Xanthomonas campestris.Furthermore,its adsorption capacity was(0.235±0.073)mg/g melanin for Zn and(0.277±0.008)mg/g melanin for Ni.In plants of Brassica chinensis grown under conditions of hydroponic cultivation with single heavy metal contamination of Cd,Zn,Pb,or Cr,the removal efficiency of each heavy metal was improved by 0.1–1.8 times after 3 d following inoculation with the strain ME1 compared to the plants grown under the same conditions without inoculation.In addition,ME1 inoculation improved the removal efficiency of each heavy metal by 0.1–1.0 times under multiple heavy metal contamination conditions.These findings suggest that Acinetobacter sp.ME1 could be used to enhance phytoremediation efficiency in heavy metal-contaminated soils.Moreover,the melanin it produces also holds promise in cosmetics,household products,and medical applications due to its photoprotective,antioxidant,and antimicrobial properties.展开更多
Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whiten...Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.展开更多
In our previous studies,we obtained scallops with black mantles by treating fertilized eggs with EMS(ethylmethane sulfonate)in the Argopecten scallop variety“Bohai”.While scallops that are potentially rich in melani...In our previous studies,we obtained scallops with black mantles by treating fertilized eggs with EMS(ethylmethane sulfonate)in the Argopecten scallop variety“Bohai”.While scallops that are potentially rich in melanin may have higher market values,the mechanisms underlying the occurrence of these black-mantled are largely unknown.We sequenced and compared the transcriptomes and metabolomes of the mantles from the black-mantled“Bohai Red”scallops and those from the scallops with normal-colored(white)mantles.Results reveal that the pigment component in the black mantle of scallops was melanin indeed.Based on the transcriptome data,1314 differentially expressed genes were obtained and subjected to the gene ontology(GO)enrichment analysis.The upregulated genes in the black mantle were mainly enriched in transition metal ion binding,hydrolytic enzyme activity,and copper ion binding.Several candidate genes associated with black mantle formation in scallops were identified.Among them,the downregulation of monoamine oxidase(MAO)and glutathione S-transferases(GST)genes and upregulation of cytochrome P 450 family 3 subfamily A(CYP 3 A)and protein kinase A(PKA)genes may have a positive effect on the formation of black mantle in scallops.The differentially expressed metabolites were mainly enriched in metabolism-related biological pathways,suggesting that the formation of black mantle in scallops may affect physiological functions related to metabolism in scallops.This study provided new evidence for understanding the mechanisms of coloration in scallop tissues,which eventually benefit the selection of new scallop strain with high melanin content.展开更多
OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real ...OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real time.We applied cupping at the following five Bladder Meridian acupoints.To investigate optimal intensity,negative pressure intensity was increased every 2 min up to 80 k Pa.To investigate optimal time,10 measurement sites were selected and negative pressure intensities of 30,60,and 80 k Pa were applied for 5 min each.Skin color information was analyzed by the following skin color values:red color saturation,erythema index,and melanin index.RESULTS:The red color saturation and erythema index increased steadily up to 60 kpa negative pressure intensity,then decreased between 60 and 80 k Pa.Therefore,maximal values were observed at 60 k Pa.The melanin index consistently increased with increasing negative pressure intensity.The red color saturation and erythema index did not change after 20 s at 60 k Pa negative pressure intensity.For negative pressure intensities below 80 k Pa,significant changes in melanin index were not observed after 20 s.At 80 k Pa negative pressure intensity,the melanin index exhibited an increasing pattern for200 s,then showed no changes.CONCLUSIONS:To minimize skin deformation,60 k Pa and 20 s were the appropriate intensity and duration when using red color saturation and erythema index as diagnostic indexes.Because of the increasing pattern up to 80 k Pa negative pressure intensity,the optimal intensity of melanin index could not be determined.When applying 80 k Pa negative pressure intensity and using melanin index as the diagnostic index,we recommend a duration of 200 s.展开更多
Objective:To investigate the suitability of citrus-press cakes,by-products of the juice industry as a source for the whitening agents for cosmetic industry.Methods:Ethylacetate extracts of citrus-press cakes(CCE)were ...Objective:To investigate the suitability of citrus-press cakes,by-products of the juice industry as a source for the whitening agents for cosmetic industry.Methods:Ethylacetate extracts of citrus-press cakes(CCE)were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese,tyrosinase-related protein-1(TRP-1),TRP2,and microphthalmia-associated transcription factor(MITF)proteins.To apply the topical agents,citrus-press cakes was investigated the safety in human skin cell line.Finally flavonoid analysis of CCE was also determined by HPLC analysis.Results:Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern.The CCE inhibited tyrosinase,TRP-2,and MITF expressions in a dose-dependent manner.To test the applicability of CCE to human skin,we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells.The CCE exhibited low cytotoxicity at 50μg/mL.Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin,narirutin,and hesperidin.Conclusions:Considering the anti-melanogenic activity and human safety,CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.展开更多
The gene, SLC7All, which encodes the solute carrier family 7 member 11 （anionic amino acid transporter light chain, xCT）, has been reported to be implicated in multiple processes such as in pheomelanin production, c...The gene, SLC7All, which encodes the solute carrier family 7 member 11 （anionic amino acid transporter light chain, xCT）, has been reported to be implicated in multiple processes such as in pheomelanin production, cell proliferation and migration, Kaposi＇s sarcoma herpesvirus （KSHV） entry into the host cells, learning and memory. Its involvement in cancer cell proliferation and metastasis has been widely studied. Its role in pheomelanogenesis is likely conserved in sheep. The full-length cDNA of sheep SLC7A11 was cloned from sheep skin fibroblasts for evaluating its role in regulating sheep coat color. The complete open reading frame of sheep xCT （sxCT） is 1512 bp in length, encoding a 503 amino acid polypeptide. We explored its function on pheomelanogenesis in vitro and in vivo. In the melan-a non-agouti mouse melanocytes that mainly produce eumelanin, overexpressed sxCT reduced the content of eumelanin. Using a testicular injection transgenic method, sxCT-transgenic sheep were generated and exhibited patches of brown/yellow coat, suggesting that sxCT can be selectively expressed to increase the pheomelanin production in wool. Our studies suggest that testicular injection of transgene can be used to genetically modify sheep coat color.展开更多
Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome,and plays a key role in the pigmentation of hair and skin.The abnormal expression or activation of tyrosinase is associated with ...Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome,and plays a key role in the pigmentation of hair and skin.The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism,vitiligo,melanoma and Parkinson disease.Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body,and it is also closely related to browning of fruits and vegetables and insect molting.Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these diseases.Therefore,many selective optical detection probes and small molecular inhibitors have been developed,and have made significant contributions to the basic and clinical research on these diseases.In this paper,the detection and inhibition of tyrosinase and their application in whitening products are reviewed,with special emphasis on development of fluorescent probes and inhibitors.Hopefully,this review will help design more efficient and sensitive tyrosinase probes and inhibitors,as well as shed light on novel treatment of diseases such as melanoma.展开更多
This study explored the therapeutic effects of Auricularia auricula melanin(AAM)on alcoholic liver damage in vitro and in vivo.Human normal liver L02 cells were pre-treated with ethanol and then treated with AAM to ex...This study explored the therapeutic effects of Auricularia auricula melanin(AAM)on alcoholic liver damage in vitro and in vivo.Human normal liver L02 cells were pre-treated with ethanol and then treated with AAM to explore the therapeutic effect of AAM on ethanol-induced hepatocyte injury.The results show that AAM signifi cantly elevated the cell viability,ameliorated the cell morphology,reduced the ROS and increased the GSH/GSSG of ethanol-pretreated L02 cells.Then,mice were administered with ethanol to induce acute alcoholic liver damage,and administered with AAM to further study the therapeutic effect of AAM on alcoholic liver damage in mice.As a result,AAM reduced the levels of ALT,AST,TG,and MDA,increased the levels of ADH,SOD,and CAT in liver damage mice.The therapeutic effect of AAM may be related to inhibition of CYP2E1 expression and activation of Nrf2 and its downstream antioxidase.The research enriched the bioactivity of AAM and provided some ideas for the development of melanin-related health foods.展开更多
Objective: To find anti-melanogenesis materials used in whitening cosmetics.Methods: The ethanolic leaf extract of Mallotus japonicus(M. japonicus) having an anti-melanogenesis activity was separated by a sephadex LH-...Objective: To find anti-melanogenesis materials used in whitening cosmetics.Methods: The ethanolic leaf extract of Mallotus japonicus(M. japonicus) having an anti-melanogenesis activity was separated by a sephadex LH-20 chromatography. Each fraction was measured for its tyrosinase inhibitory activity together with its polyphenol content using the Folin–Ciocalteu method. The anti-melanogenesis activity of the active fractions was determined by the melanin content in the murine B16F1 melanoma. The active fractions were put together due to similar constituents, and then separated by high performance liquid chromatography using a C-18 ODS column. The major antimelanogenesis compound was identified using1 H and13C-NMR and liquid chromatography-mass spectrometry.Results: The ethanolic leaf extract of M. japonicus showed an anti-tyrosinase activity with a high polyphenol content, resulting in suppression of melanin production in the B16F1 melanoma. The extract was separated and the active compound was identical as rutin based on the1 H,13C-NMR and liquid chromatography-mass spectrometry analysis data. In addition, the rutin treatment with cells reduced the melanin content in a concentration dependent manner without any cell toxicity. The leaf extract of M. japonicus containing rutin would be useful in whitening cosmetics for protection from UV-light exposure to be limiting the accumulation of melanin in skin.Conclusions: The leaf extract of M. japonicus and/or rutin isolated from the extract as a key whitening agent would be useful as a whitening cosmetic material for protecting against disorder skin due to melanin accumulation.展开更多
Albino Apostichopus japonicus occur both in the wild and in captivity.The offspring of albino A.japonicus also suffer from albinism.The formation of melanin in the melanocytes is dependant on microphthalmia-associated...Albino Apostichopus japonicus occur both in the wild and in captivity.The offspring of albino A.japonicus also suffer from albinism.The formation of melanin in the melanocytes is dependant on microphthalmia-associated transcription factor(MITF).To investigate the role of MITF in controlling albinism,we cloned the full-length MITF cDNA from A.japonicus and compared MITF mRNA expression in albino and normal A.japonicus.In addition,we used light and electron microscopy to compare histological samples of normal and albino A.japonicus.The body wall of albino adults was characterized by significantly lower levels of MITF expression and lower numbers of epidermal melanocytes,which also contained less melanin.In albino juvenile offspring,MITF expression levels were significantly lower 32 d after fertilization and there were fewer,and less developed,epidermal melanocytes.Thus,we conclude that albino A.japonicus have fewer melanocytes and a reduced ability to synthesize melanin,likely because of lower expression of MITF.展开更多
Setosphaeria turcica(syn.Exserohilum turcicum)is the pathogenic fungus of maize(Zea mays)that causes northern leaf blight,which is a major maize disease worldwide.Melanized appressoria are highly specialized infection...Setosphaeria turcica(syn.Exserohilum turcicum)is the pathogenic fungus of maize(Zea mays)that causes northern leaf blight,which is a major maize disease worldwide.Melanized appressoria are highly specialized infection structures formed by germinated conidia of S.turcica that infect maize leaves.The appressorium penetrates the plant cuticle by generating turgor,and glycerol is known to be the main source of the turgor.Here,the infection position penetrated by the appressorium on maize leaves was investigated,most of the germinated conidia entered the leaf interior by directly penetrating the epidermal cells,and the appressorium structure was necessary for the infection,whether it occurred through epidermal cells or stomata.Then,to investigate the effects of key factors in the development of the appressorium,we studied the effects of three inhibitors,including a melanin inhibitor(tricyclazole,TCZ),a DNA replication inhibitor(hydroxyurea,HU),and an autophagy inhibitor(3-methyladenine,3-MA),on appressorium turgor and glycerol content.As results,appressorium turgor pressure and glycerol concentration in the appressorium reached their highest levels at the mature stage of the appressorium under the control and inhibitor treatments.The three inhibitors had the greatest effects on appressorium turgor pressure at this stage.Glycogen and liposomes are the main substances producing glycerol.It was also found inhibitors affected the distribution of glycogen and liposomes,which were detected in the conidia,the germ tube,and the appressorium during appressorium development.This study provides profound insight into the relationship between appressorium turgor pressure and glycerol content,which was affected by the synthesis of melanin,DNA replication,and autophagy in the developing appressorium during a S.turcica infection.展开更多
Objectives: To investigate possible sources of Stenotrophomonas maltophilia(S. maltophilia) in the clinical environment.Methods: Different samples were collected from Amol City of Iran. Steps for the identification of...Objectives: To investigate possible sources of Stenotrophomonas maltophilia(S. maltophilia) in the clinical environment.Methods: Different samples were collected from Amol City of Iran. Steps for the identification of S. maltophilia included culturing, biochemical tests, polymerase chain reaction(PCR) of 16 S r RNA gene and 23 S r RNA gene. In addition, production of melanin pigment and patterns of motility of the bacteria, were also investigated.Results: In our study, 20 S. maltophilia strains were isolated from clinical sources,oxygen manometer apparatus of hospitals were 7/110(6.36%), blood was 1/777(0.13%),sputum was 4/40(4%), urine was 1/2 947(0.03%), tap water was 1/240(0.42%) and dental suction was 6/120(5%). The isolated bacteria showed production of melanin pigment with rates of strong, moderate, weak, and lack of pigment. Types of motilities were seen in isolates.Conclusions: The highest percentage of bacteria is isolated of oxygen manometer system and dental suction, yet has not been reported from oxygen manometer system. These bacteria have also been associated with patients who have respiratory problems, so it is essential for staffs of hospitals to draw attention to this source of bacteria.展开更多
Melanin nanoparticles(MNPs) is a kind of natural nanomaterial, not only retain the inherent characteristics of melanin(metal ion chelation, photothermal conversion property, etc.) but also can exhibit more excellent p...Melanin nanoparticles(MNPs) is a kind of natural nanomaterial, not only retain the inherent characteristics of melanin(metal ion chelation, photothermal conversion property, etc.) but also can exhibit more excellent properties, such as high dispersion stability, good biocompatibility and biodegradability. Furthermore, these performances can be enhanced to target the specific sites and treat diseases by the surface modification or combination with functional substance. All these advantages of MNPs made it an ideal platform for developing biomedical applications. In this paper, the MNPs preparation methods were summarized first. Biomedical applications of MNPs were also reviewed,including molecular imaging(magnetic resonance, positron emission tomography, and photoacoustic imaging) and treatment of diseases(drug delivery, photothermal therapy, antioxidant therapy, and iron overload therapy). Further development and prospects of MNPs for practice in biology or medicine were also discussed.展开更多
The color of Mollusca shells is one of the most important attributes to consumers.At the cellular level,black color is mainly from the melanin produced by melanocytes.The melanosome is a specialized membrane-bound org...The color of Mollusca shells is one of the most important attributes to consumers.At the cellular level,black color is mainly from the melanin produced by melanocytes.The melanosome is a specialized membrane-bound organelle that is involved in melanin synthesis,storage,and transportation.How the complex pigmentation process in the Crassostrea gigas is established remains an open question.The objectives of this studies are to examine the morphological characteristics of melanosomes or melanin of mantle pigmentation in the Pacific oyster,thereby investigating its contribution to shell color.The results show that pigmented granules of the mantles vary among the three lobes,and the melanosomes at different stages are enriched in distinct cargo molecules,which indicate the remarkable difference between the marginal mantle and central mantle.Examination of mantle histology reveals that the mantle margin of the oyster is characterized by three different folds,including the outer secretory,middle sensory,and inner muscular fold.Ferrous ion chelating assays against the tyrosine hydroxylase indicate that a large amount of melanin is localized in the inner surface of the middle fold.Transmission electron microscopy analyses show that the mantle edge is composed of tall columnar and cuboidal epidermal cells and some pigmented melanocytes intersperse among these cells.The numbers of melanosomes among the three lobes are different.In the inner fold and the middle fold of the mantle,some single dispersion,or aggregation of melanosomes with different degrees of melanization are found in the outer surface.Numerous melanosomes are distributed in the epithelium of the outer fold of the mantle,and mainly are at the apical microvillar surface near the lumen.However,melanosomes are occasionally observed in the central mantle,and they are relatively less.This work provides new insights into the process of melanin deposit in the mantle and shell pigmentation in C.gigas.展开更多
A variety of shell colors are one of the most fundamental characteristics of molluscs,which have importantly ecological and economic signifi cance.The Pacifi c oyster Crassostrea gigas is distributed in many sea areas...A variety of shell colors are one of the most fundamental characteristics of molluscs,which have importantly ecological and economic signifi cance.The Pacifi c oyster Crassostrea gigas is distributed in many sea areas around the world and also an aquacultured mollusc with high nutritional value.In this study,the whole soft body and the mantle tissue of black-shelled Pacifi c oyster(BSO)and white-shelled Pacifi c oyster(WSO)with starkly diff erent melanin contents were compared,and the diff erences in physiology and metabolism between BSO and WSO were analyzed.The results of physiological indicators suggested BSO show more melanin,more dry matter,more crude lipid content,and stronger ability to scavenge free radicals than WSO.The altered metabolites of glycerophospholipids,fatty acyls,and steroids revealed diff erent regulatory mechanisms of lipids.The correlation analysis of metabolomics and previously published RNAseq data suggested that BSO and WSO mainly diff ered in the basal metabolic processes,such as lipid,amino acid and purine metabolisms.This study provides insights into the changes in the physiological indictors and the metabolites of oysters with varying melanin content.展开更多
基金the National Natural Science Foundation of China, No. 30600201the Tianjin Science and Technology Committee, No. 07JCYBJC09900
文摘To investigate the effects of oxidative stress on substantia nigra neuronal degeneration and death in patients with Parkinson＇s disease, we treated neuroblastoma cells （SK-N-SH） and glioma cells with Fenton＇s reagent, iron chelating agent, neuromelanin and dopamine melanin. We investigated the changes in expression of nine oxidative stress-related genes and proteins. The levels of mRNAs for heme-oxygenase-1 and glutathione S-transferase-ml were significantly reduced in SK-N-SH cells exposed to oxidative stress, and increased in glial cells treated with deferoxamine. These results revealed that SK-N-SH neurons react sensitively to oxidative stress, which implies different outcomes between these two types of cells in the substantia nigra. Moreover, the influences of neuromelanin and dopamine melanin on cell function are varied, and dopamine melanin is not a good model for neuromelanin.
基金supported by the National Natural Science Foundation of China (Nos.81973410 and 82473537)the Independent Research Fund of Yunnan Characteristic Plant Extraction Laboratory (Nos.2022YKZY002 and 2022YKZY004)。
文摘Nigella sativa L.seeds have been traditionally utilized in Chinese folk medicine for centuries to treat vitiligo.This study revealed that the ethanolic extract of Nigella sativa L.(HZC)enhances melanogenesis and mitigates oxidative stress-induced cellular senescence and dysfunction in melanocytes.In accordance with established protocols,the ethanol fraction from Nigella sativa L.seeds was extracted,concentrated,and lyophilized to evaluate its herbal effects via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assays,tyrosinase activity evaluation,measurement of cellular melanin contents,scratch assays,senescence-associatedβ-galactosidase(SA-β-gal)staining,enzyme-linked immunosorbent assay(ELISA),and Western blot analysis for expression profiling of experimentally relevant proteins.The results indicated that HZC significantly enhanced tyrosinase activity and melanin content while notably increasing the protein expression levels of Tyr,Mitf,and gp100 in B16F10 cells.Furthermore,HZC effectively mitigated oxidative stress-induced cellular senescence,improved melanocyte condition,and rectified various functional impairments associated with melanocyte dysfunction.These findings suggest that HZC increases melanin synthesis in melanocytes through the activation of the MAPK,PKA,and Wnt signaling pathways.In addition,HZC attenuates oxidative damage induced by H2O2 therapy by activating the nuclear factor E2-related factor 2-antioxidant response element(Nrf2-ARE)pathway and enhancing the activity of downstream antioxidant enzymes,thus preventing premature senescence and dysfunction in melanocytes.
基金financially supported by the National Natural Science Foundation of China(No.52225311)the Fundamental Research Funds for Central Universities.
文摘Hair coloring has emerged as an integral part of the cosmetic industry,particularly in response to the increasing global aging phenomenon.The natural melanin analog,polydopamine(PDA),has garnered considerable attention as an eco-friendly hair dye,and several kinds of polymerization ways of dopamine(DA)have been proposed including alkali catalysis,metal ion catalysis,strong oxidants,and enzyme-mediated oxidation reactions and polymerizations.Yet the controllability of polymerization and potential toxicity of involved metal ions are still in question.Inspired by the photoprotective mechanism in human skin,we have developed the melanin-inspired hair dyeing strategy that allowed for the in situ oxidative polymerization of DA under ultraviolet(UV)light.This polymerization was triggered by photobase generators(PBGs),a class of compounds that produced organic bases upon UV and sunlight irradiation.The resulting hair showed an adjustable color from light brown to black by tuning the ratio of DA and PBG(DA@PBG),the concentration of DA,and light exposure time.The dyed hairs showed excellent washing resistance and superior anti-static properties.Furthermore,Hair Color Spray DA@PBG also demonstrated a desirable hair dyeing effect and excellent biosecurity by simply spraying it on the hair under sunlight.This novel sunlight-induced method provided a new direction towards the preparation of natural hair dyes and could promote the development of green and safe hair dyes in colorful and brilliant artistic-grade hair coloring.
文摘Objective:Tyrosinase is the rate-limiting enzyme in the generation of melanin.The feline tyrosinase mutation,G302R,confers temperature-sensitive loss of function,resulting in the familiar Siamese cat phenotype.Crystal or cryoEM structures are elusive for any mammalian tyrosinase to date.Protein misfolding is suggested as a basis for phenotypes resulting frommutant tyrosinases,but this hypothesis needs structural confirmation.Our objective for this study is to confirm misfolding of mutant tyrosinase as a basis for temperature-sensitive phenotypes compared to catalytic dysfunction that may be responsible for other tyrosinase mutant breed phenotypes.Methods:We have employed AlphaFold3 to compare structural alignments of four well-characterized feline tyrosinase mutations to wild type(WT)feline tyrosinase;SiameseG302R,Burmese G227W,Mocha delI274-L312+2aa,andAlbino del401-529 lacking the transmembrane and C-terminus domains.Results:The manifestations of the bulkier side chains of the Siamese positively charged arginine(R)and the Burmese hydrophobic tryptophan(W)are evident locally.But interestingly,the major differences between the structures lie in the usually ignored signal peptide(SP)regions of each mutant.As the maturation of the nascent tyrosinase peptide is highly dependent on accurate and early cleavage of the SP,we hypothesize these structural anomaliesmay formthe basis formisfolded or truncated final enzyme forms,leading to the observed phenotypes seen in these cats.Conclusions:We have identified enzyme dysfunction and protein misfolding as separate mechanisms for feline coat phenotypes resulting from tyrosinase mutations.
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Korean government,the Ministry of Science,and the Ministry of Science and Information and Communication Technology(ICT(MSIT))(Nos.2022R1A2C2006615 and RS2023-00217228).
文摘Microorganisms inhabiting soils contaminated with heavy metals produce melanin,a dark brown pigment,as a survival strategy.In this study,a melanin-producing bacterium,Acinetobacter sp.ME1,with heavy metal tolerance and plant growth-promoting traits,was isolated from abandoned mine soil.Strain ME1 exhibited growth at concentrations of Zn up to 250 mg/L,Cd and Pb up to 100 mg/L,and Cr up to 50 mg/L.It had the ability to produce the plant hormone indole-3-acetic acid and siderophores along with 1-aminocyclopropane-1-carboxylic acid deaminase and protease activities.Additionally,it showed antioxidant activity,including catalase and 2,2-diphenyl-1-picryhydrazyl(DPPH)scavenging activities.The optimal conditions for melanin production by ME1 were a pH of 7 and a temperature of 35℃.At 1000 mg/L,ME1-extracted melanin exhibited DPPH radical scavenging activity of(25.040±0.007)%,a sun protection factor of 15.200±0.260,and 19.6%antibacterial activity against the plant pathogen Xanthomonas campestris.Furthermore,its adsorption capacity was(0.235±0.073)mg/g melanin for Zn and(0.277±0.008)mg/g melanin for Ni.In plants of Brassica chinensis grown under conditions of hydroponic cultivation with single heavy metal contamination of Cd,Zn,Pb,or Cr,the removal efficiency of each heavy metal was improved by 0.1–1.8 times after 3 d following inoculation with the strain ME1 compared to the plants grown under the same conditions without inoculation.In addition,ME1 inoculation improved the removal efficiency of each heavy metal by 0.1–1.0 times under multiple heavy metal contamination conditions.These findings suggest that Acinetobacter sp.ME1 could be used to enhance phytoremediation efficiency in heavy metal-contaminated soils.Moreover,the melanin it produces also holds promise in cosmetics,household products,and medical applications due to its photoprotective,antioxidant,and antimicrobial properties.
文摘Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.
基金Supported by the Natural Science Foundation of Shandong Province(No.ZR 2020 MC 192)the Agricultural Industrial Technology System in Shandong Province(No.SDIT-14)+2 种基金the Fund for Agriculture Seed Improvement Project of Shandong Province(No.2020 LZGC 016)the Scientific and Technological Project of Yantai,Shandong Province(No.2022 XCZX 083)the Science and Technology Innovation Capacity Improvement Project of Shandong Province(No.2021 TSGC 1229)。
文摘In our previous studies,we obtained scallops with black mantles by treating fertilized eggs with EMS(ethylmethane sulfonate)in the Argopecten scallop variety“Bohai”.While scallops that are potentially rich in melanin may have higher market values,the mechanisms underlying the occurrence of these black-mantled are largely unknown.We sequenced and compared the transcriptomes and metabolomes of the mantles from the black-mantled“Bohai Red”scallops and those from the scallops with normal-colored(white)mantles.Results reveal that the pigment component in the black mantle of scallops was melanin indeed.Based on the transcriptome data,1314 differentially expressed genes were obtained and subjected to the gene ontology(GO)enrichment analysis.The upregulated genes in the black mantle were mainly enriched in transition metal ion binding,hydrolytic enzyme activity,and copper ion binding.Several candidate genes associated with black mantle formation in scallops were identified.Among them,the downregulation of monoamine oxidase(MAO)and glutathione S-transferases(GST)genes and upregulation of cytochrome P 450 family 3 subfamily A(CYP 3 A)and protein kinase A(PKA)genes may have a positive effect on the formation of black mantle in scallops.The differentially expressed metabolites were mainly enriched in metabolism-related biological pathways,suggesting that the formation of black mantle in scallops may affect physiological functions related to metabolism in scallops.This study provided new evidence for understanding the mechanisms of coloration in scallop tissues,which eventually benefit the selection of new scallop strain with high melanin content.
基金Supported by the Industrial Technology Innovation Program(Development of Safe and Comfortable Human augmentation Hybrid Robot Suit)Funded by the Ministry of Trade,Industry&Energy,No.20007058,MOTIE,Korea)。
文摘OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real time.We applied cupping at the following five Bladder Meridian acupoints.To investigate optimal intensity,negative pressure intensity was increased every 2 min up to 80 k Pa.To investigate optimal time,10 measurement sites were selected and negative pressure intensities of 30,60,and 80 k Pa were applied for 5 min each.Skin color information was analyzed by the following skin color values:red color saturation,erythema index,and melanin index.RESULTS:The red color saturation and erythema index increased steadily up to 60 kpa negative pressure intensity,then decreased between 60 and 80 k Pa.Therefore,maximal values were observed at 60 k Pa.The melanin index consistently increased with increasing negative pressure intensity.The red color saturation and erythema index did not change after 20 s at 60 k Pa negative pressure intensity.For negative pressure intensities below 80 k Pa,significant changes in melanin index were not observed after 20 s.At 80 k Pa negative pressure intensity,the melanin index exhibited an increasing pattern for200 s,then showed no changes.CONCLUSIONS:To minimize skin deformation,60 k Pa and 20 s were the appropriate intensity and duration when using red color saturation and erythema index as diagnostic indexes.Because of the increasing pattern up to 80 k Pa negative pressure intensity,the optimal intensity of melanin index could not be determined.When applying 80 k Pa negative pressure intensity and using melanin index as the diagnostic index,we recommend a duration of 200 s.
基金Supported by the Next-Generation BioGreen 21 Program,Rural Development Administration,Republic of Korea,Grant No.PJ009583002013
文摘Objective:To investigate the suitability of citrus-press cakes,by-products of the juice industry as a source for the whitening agents for cosmetic industry.Methods:Ethylacetate extracts of citrus-press cakes(CCE)were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese,tyrosinase-related protein-1(TRP-1),TRP2,and microphthalmia-associated transcription factor(MITF)proteins.To apply the topical agents,citrus-press cakes was investigated the safety in human skin cell line.Finally flavonoid analysis of CCE was also determined by HPLC analysis.Results:Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern.The CCE inhibited tyrosinase,TRP-2,and MITF expressions in a dose-dependent manner.To test the applicability of CCE to human skin,we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells.The CCE exhibited low cytotoxicity at 50μg/mL.Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin,narirutin,and hesperidin.Conclusions:Considering the anti-melanogenic activity and human safety,CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.
基金supported by the grants from the Ministry of Agriculture of the People's Republic of China(No. 2009ZX08009-158B)the National Natural Science Foundation of China(No.31071252)
文摘The gene, SLC7All, which encodes the solute carrier family 7 member 11 （anionic amino acid transporter light chain, xCT）, has been reported to be implicated in multiple processes such as in pheomelanin production, cell proliferation and migration, Kaposi＇s sarcoma herpesvirus （KSHV） entry into the host cells, learning and memory. Its involvement in cancer cell proliferation and metastasis has been widely studied. Its role in pheomelanogenesis is likely conserved in sheep. The full-length cDNA of sheep SLC7A11 was cloned from sheep skin fibroblasts for evaluating its role in regulating sheep coat color. The complete open reading frame of sheep xCT （sxCT） is 1512 bp in length, encoding a 503 amino acid polypeptide. We explored its function on pheomelanogenesis in vitro and in vivo. In the melan-a non-agouti mouse melanocytes that mainly produce eumelanin, overexpressed sxCT reduced the content of eumelanin. Using a testicular injection transgenic method, sxCT-transgenic sheep were generated and exhibited patches of brown/yellow coat, suggesting that sxCT can be selectively expressed to increase the pheomelanin production in wool. Our studies suggest that testicular injection of transgene can be used to genetically modify sheep coat color.
基金This work was financially supported by the National Natural Science Foundation of China(81672508,21675085)Jiangsu Provincial Foundation for Distinguished Young Scholars(BK20170041,BK20170042)+5 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-008,2020GXLH-Z-023)the Natural Science Basic Research Programof Shaanxi(Program No.2019JM-016)Key Research and Development Program of Shaanxi(2020ZDLGY13-04)Open Research Fund of Anhui Key Laboratory of Tobacco Chemistry(20181140)China-Sweden Joint Mobility Project(51811530018)Fundamental Research Funds for the Central Universities.
文摘Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome,and plays a key role in the pigmentation of hair and skin.The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism,vitiligo,melanoma and Parkinson disease.Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body,and it is also closely related to browning of fruits and vegetables and insect molting.Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these diseases.Therefore,many selective optical detection probes and small molecular inhibitors have been developed,and have made significant contributions to the basic and clinical research on these diseases.In this paper,the detection and inhibition of tyrosinase and their application in whitening products are reviewed,with special emphasis on development of fluorescent probes and inhibitors.Hopefully,this review will help design more efficient and sensitive tyrosinase probes and inhibitors,as well as shed light on novel treatment of diseases such as melanoma.
基金This work was financially supported by the Special Fund Project for Technological Innovation of Fujian Agriculture and Forestry University(CXZX2019055G)the Science and Technology Project on Social Development of Cixi(CN2020027).
文摘This study explored the therapeutic effects of Auricularia auricula melanin(AAM)on alcoholic liver damage in vitro and in vivo.Human normal liver L02 cells were pre-treated with ethanol and then treated with AAM to explore the therapeutic effect of AAM on ethanol-induced hepatocyte injury.The results show that AAM signifi cantly elevated the cell viability,ameliorated the cell morphology,reduced the ROS and increased the GSH/GSSG of ethanol-pretreated L02 cells.Then,mice were administered with ethanol to induce acute alcoholic liver damage,and administered with AAM to further study the therapeutic effect of AAM on alcoholic liver damage in mice.As a result,AAM reduced the levels of ALT,AST,TG,and MDA,increased the levels of ADH,SOD,and CAT in liver damage mice.The therapeutic effect of AAM may be related to inhibition of CYP2E1 expression and activation of Nrf2 and its downstream antioxidase.The research enriched the bioactivity of AAM and provided some ideas for the development of melanin-related health foods.
文摘Objective: To find anti-melanogenesis materials used in whitening cosmetics.Methods: The ethanolic leaf extract of Mallotus japonicus(M. japonicus) having an anti-melanogenesis activity was separated by a sephadex LH-20 chromatography. Each fraction was measured for its tyrosinase inhibitory activity together with its polyphenol content using the Folin–Ciocalteu method. The anti-melanogenesis activity of the active fractions was determined by the melanin content in the murine B16F1 melanoma. The active fractions were put together due to similar constituents, and then separated by high performance liquid chromatography using a C-18 ODS column. The major antimelanogenesis compound was identified using1 H and13C-NMR and liquid chromatography-mass spectrometry.Results: The ethanolic leaf extract of M. japonicus showed an anti-tyrosinase activity with a high polyphenol content, resulting in suppression of melanin production in the B16F1 melanoma. The extract was separated and the active compound was identical as rutin based on the1 H,13C-NMR and liquid chromatography-mass spectrometry analysis data. In addition, the rutin treatment with cells reduced the melanin content in a concentration dependent manner without any cell toxicity. The leaf extract of M. japonicus containing rutin would be useful in whitening cosmetics for protection from UV-light exposure to be limiting the accumulation of melanin in skin.Conclusions: The leaf extract of M. japonicus and/or rutin isolated from the extract as a key whitening agent would be useful as a whitening cosmetic material for protecting against disorder skin due to melanin accumulation.
基金Supported by the National Natural Science Foundation of China(No.40976089)the National Marine Public Welfare Research Project(No.200805069)+1 种基金the National Science and Technology Support Program of China(No.2011BAD13B02)the Breeding Project of Shandong Province(China)
文摘Albino Apostichopus japonicus occur both in the wild and in captivity.The offspring of albino A.japonicus also suffer from albinism.The formation of melanin in the melanocytes is dependant on microphthalmia-associated transcription factor(MITF).To investigate the role of MITF in controlling albinism,we cloned the full-length MITF cDNA from A.japonicus and compared MITF mRNA expression in albino and normal A.japonicus.In addition,we used light and electron microscopy to compare histological samples of normal and albino A.japonicus.The body wall of albino adults was characterized by significantly lower levels of MITF expression and lower numbers of epidermal melanocytes,which also contained less melanin.In albino juvenile offspring,MITF expression levels were significantly lower 32 d after fertilization and there were fewer,and less developed,epidermal melanocytes.Thus,we conclude that albino A.japonicus have fewer melanocytes and a reduced ability to synthesize melanin,likely because of lower expression of MITF.
基金supported by the grants from the National Natural Science Foundation of China(32072370 and 31901827)the China Agriculture Research System of MOF and MARA(CARS-02-25)+1 种基金the Natural Science Foundation of Hebei Province,China(C2020204039 and C2018204059)the Projects of Overseas Foundation,Hebei Province,China(C20190508)。
文摘Setosphaeria turcica(syn.Exserohilum turcicum)is the pathogenic fungus of maize(Zea mays)that causes northern leaf blight,which is a major maize disease worldwide.Melanized appressoria are highly specialized infection structures formed by germinated conidia of S.turcica that infect maize leaves.The appressorium penetrates the plant cuticle by generating turgor,and glycerol is known to be the main source of the turgor.Here,the infection position penetrated by the appressorium on maize leaves was investigated,most of the germinated conidia entered the leaf interior by directly penetrating the epidermal cells,and the appressorium structure was necessary for the infection,whether it occurred through epidermal cells or stomata.Then,to investigate the effects of key factors in the development of the appressorium,we studied the effects of three inhibitors,including a melanin inhibitor(tricyclazole,TCZ),a DNA replication inhibitor(hydroxyurea,HU),and an autophagy inhibitor(3-methyladenine,3-MA),on appressorium turgor and glycerol content.As results,appressorium turgor pressure and glycerol concentration in the appressorium reached their highest levels at the mature stage of the appressorium under the control and inhibitor treatments.The three inhibitors had the greatest effects on appressorium turgor pressure at this stage.Glycogen and liposomes are the main substances producing glycerol.It was also found inhibitors affected the distribution of glycogen and liposomes,which were detected in the conidia,the germ tube,and the appressorium during appressorium development.This study provides profound insight into the relationship between appressorium turgor pressure and glycerol content,which was affected by the synthesis of melanin,DNA replication,and autophagy in the developing appressorium during a S.turcica infection.
基金funded by Islamic Azad University Karaj Branch (grant number: 1193)
文摘Objectives: To investigate possible sources of Stenotrophomonas maltophilia(S. maltophilia) in the clinical environment.Methods: Different samples were collected from Amol City of Iran. Steps for the identification of S. maltophilia included culturing, biochemical tests, polymerase chain reaction(PCR) of 16 S r RNA gene and 23 S r RNA gene. In addition, production of melanin pigment and patterns of motility of the bacteria, were also investigated.Results: In our study, 20 S. maltophilia strains were isolated from clinical sources,oxygen manometer apparatus of hospitals were 7/110(6.36%), blood was 1/777(0.13%),sputum was 4/40(4%), urine was 1/2 947(0.03%), tap water was 1/240(0.42%) and dental suction was 6/120(5%). The isolated bacteria showed production of melanin pigment with rates of strong, moderate, weak, and lack of pigment. Types of motilities were seen in isolates.Conclusions: The highest percentage of bacteria is isolated of oxygen manometer system and dental suction, yet has not been reported from oxygen manometer system. These bacteria have also been associated with patients who have respiratory problems, so it is essential for staffs of hospitals to draw attention to this source of bacteria.
基金financial support from the National Natural Science Foundation of China (Nos. 31671035, 51473071, 51803082)Natural Science Foundation of Jiangsu Province(No. BK20170204)+2 种基金Jiangsu Provincial Medical Innovation Team (No. CXTDA2017024)Innovation Capacity Development Plan of Jiangsu Province (No. BM2018023)Jiangsu Provincial Key Medical Discipline (No. ZDXKA2016017)
文摘Melanin nanoparticles(MNPs) is a kind of natural nanomaterial, not only retain the inherent characteristics of melanin(metal ion chelation, photothermal conversion property, etc.) but also can exhibit more excellent properties, such as high dispersion stability, good biocompatibility and biodegradability. Furthermore, these performances can be enhanced to target the specific sites and treat diseases by the surface modification or combination with functional substance. All these advantages of MNPs made it an ideal platform for developing biomedical applications. In this paper, the MNPs preparation methods were summarized first. Biomedical applications of MNPs were also reviewed,including molecular imaging(magnetic resonance, positron emission tomography, and photoacoustic imaging) and treatment of diseases(drug delivery, photothermal therapy, antioxidant therapy, and iron overload therapy). Further development and prospects of MNPs for practice in biology or medicine were also discussed.
基金supported by grants from the National Natural Science Foundation of China(Nos.31772843 and 31972789)the National Key R&D Program of China(No.2018YFD0900200)+1 种基金the Earmarked Fund for Agriculture Seed Improvement Project of Shandong Province(No.2017LZGC009)the Ocean University of China-Auburn University Joint Research Center for Aquaculture and Environmental Science。
文摘The color of Mollusca shells is one of the most important attributes to consumers.At the cellular level,black color is mainly from the melanin produced by melanocytes.The melanosome is a specialized membrane-bound organelle that is involved in melanin synthesis,storage,and transportation.How the complex pigmentation process in the Crassostrea gigas is established remains an open question.The objectives of this studies are to examine the morphological characteristics of melanosomes or melanin of mantle pigmentation in the Pacific oyster,thereby investigating its contribution to shell color.The results show that pigmented granules of the mantles vary among the three lobes,and the melanosomes at different stages are enriched in distinct cargo molecules,which indicate the remarkable difference between the marginal mantle and central mantle.Examination of mantle histology reveals that the mantle margin of the oyster is characterized by three different folds,including the outer secretory,middle sensory,and inner muscular fold.Ferrous ion chelating assays against the tyrosine hydroxylase indicate that a large amount of melanin is localized in the inner surface of the middle fold.Transmission electron microscopy analyses show that the mantle edge is composed of tall columnar and cuboidal epidermal cells and some pigmented melanocytes intersperse among these cells.The numbers of melanosomes among the three lobes are different.In the inner fold and the middle fold of the mantle,some single dispersion,or aggregation of melanosomes with different degrees of melanization are found in the outer surface.Numerous melanosomes are distributed in the epithelium of the outer fold of the mantle,and mainly are at the apical microvillar surface near the lumen.However,melanosomes are occasionally observed in the central mantle,and they are relatively less.This work provides new insights into the process of melanin deposit in the mantle and shell pigmentation in C.gigas.
基金Supported by the Agricultural Variety Improvement Project of Shandong Province(No.2019LZGC020),the National Natural Science Foundation of China(Nos.41906088,41876193,31802328)the National Key R&D Program of China(No.2018YFD0901400)+2 种基金the Special Funds for Taishan Scholars Project of Shandong Province,China(No.tsqn201812094)the Shandong Provincial Natural Science Foundation,China(No.ZR2019MC002),the Modern Agricultural Industry Technology System of Shandong Province,China(No.SDAIT-14-03)the Plan of Excellent Youth Innovation Team of Colleges and universities in Shandong Province,China(No.2019KJF004)。
文摘A variety of shell colors are one of the most fundamental characteristics of molluscs,which have importantly ecological and economic signifi cance.The Pacifi c oyster Crassostrea gigas is distributed in many sea areas around the world and also an aquacultured mollusc with high nutritional value.In this study,the whole soft body and the mantle tissue of black-shelled Pacifi c oyster(BSO)and white-shelled Pacifi c oyster(WSO)with starkly diff erent melanin contents were compared,and the diff erences in physiology and metabolism between BSO and WSO were analyzed.The results of physiological indicators suggested BSO show more melanin,more dry matter,more crude lipid content,and stronger ability to scavenge free radicals than WSO.The altered metabolites of glycerophospholipids,fatty acyls,and steroids revealed diff erent regulatory mechanisms of lipids.The correlation analysis of metabolomics and previously published RNAseq data suggested that BSO and WSO mainly diff ered in the basal metabolic processes,such as lipid,amino acid and purine metabolisms.This study provides insights into the changes in the physiological indictors and the metabolites of oysters with varying melanin content.
