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BACKGROUND/AIM: Individuals with Down syndrome (DS), attributed to triplication of human chromosome 21 (Hsa21), exhibit a reduced incidence of solid tumors. However, the prevalence of glioblastoma among individuals with DS remains a contentious issue in epidemiological studies. Therefore, this study examined the gliomagenicity in Ts1Cje mice, a murine model of DS. MATERIALS AND METHODS: We employed the Sleeping Beauty transposon system for the integration of human oncogenes into cells of the subventricular zone of neonatal mice. RESULTS: Notably, Sleeping Beauty-mediated de novo murine gliomagenesis was significantly suppressed in Ts1Cje mice compared to wild-type mice. In glioblastomas of Ts1je mice, we observed an augmented presence of M1-polarized tumor-associated macrophages and microglia, known for their anti-tumor efficacy in the early stage of tumor development. CONCLUSION: Our findings in a mouse model of DS offer novel perspectives on the diminished gliomagenicity observed in individuals with DS.
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Síndrome de Down , Ratones , Animales , Humanos , Síndrome de Down/genética , Síndrome de Down/patología , Modelos Animales de EnfermedadRESUMEN
Background: The use of robot-assisted surgery for rectal cancer is increasing, but its short-term results remain unclear. We compared the short-term outcomes of robot-assisted and laparoscopic surgery for rectal cancer using a nationwide inpatient database. Methods: We analyzed patients registered in the Japanese Diagnosis Procedure Combination database who underwent robot-assisted or laparoscopic surgery for rectal cancer from April 2018 to March 2020. Postoperative complication rates, anesthesia time, length of hospital stay, and cost were compared using propensity score matching for low anterior resection (LAR), high anterior resection (HAR), and abdominoperineal resection (APR). Results: Among 38 090 rectal cancer cases, 1992 LAR, 357 HAR, and 310 APR pairs were generated by propensity score matching and analyzed. Anesthesia time was longer for robot-assisted surgery compared with laparoscopic surgery (LAR: 388.6 vs. 452.8 min, p < 0.001; HAR: 300.9 vs. 393.5 min, p < 0.001; APR: 4478.5 vs. 533.5 min, p < 0.001). Robot-assisted surgery was associated with significantly shorter hospital stay for LAR (22.3 vs. 20.0 days, p < 0.001) and APR (29.2 vs. 25.9 days, p = 0.029). Total costs for LAR were significantly lower for robot-assisted surgery (2031511.6 vs. 1955216.6 JPY, p < 0.001). The complication rates for robot-assisted surgery tended to be fewer than laparoscopic surgery for all procedures, but the differences were not significant. Conclusions: Although the anesthesia time was longer for robot-assisted surgery, the procedure resulted in shorter hospital stay for LAR and APR, and lower costs for LAR compared with laparoscopic surgery. Robot-assisted surgery can thus help to reduce costs and can be performed safely.
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Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass, loss of muscle strength and/or reduced physical performance. Sarcopenia has repeatedly been reported as a strong predictor of both short- and long-term outcomes following surgical treatment for colorectal cancer. In this study, 86 primary colorectal cancer cases who received surgery at our hospital were examined. To evaluate which factor amongst muscle volume, muscle strength or physical performance would be important to avoid sarcopenia after surgery, we examined objective values of muscle volume, muscle strength and physical performance respectively. We also divided patients into groups by their ages or procedures of surgeries, then compared and analyzed within those groups. The results showed that most patients tended to lose their muscle volume of their legs and their physical performance after their surgeries. We also found patients who were equal or older than 75-year-old and patients who received open surgeries tended to lose their muscle volume or physical performance after their surgeries. These groups of patients have a potential risk to turn sarcopenia after surgeries. It would be important to observe each of 3 factors such as skeletal muscle volume, muscle strength and physical performance to evaluate precisely their condition of sarcopenia. Tailor-made peri-operative rehabilitation programs, especially for elderly patients or patients who received open surgeries, would be a possible solution to avoid sarcopenia after surgery for colorectal cancer.
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Neoplasias Colorrectales , Sarcopenia , Humanos , Anciano , Sarcopenia/etiología , Músculo Esquelético , Periodo Perioperatorio , Neoplasias Colorrectales/cirugíaRESUMEN
We report our experience with needlescopic splenectomy (NS) for the surgical treatment of idiopathic thrombocytopenic purpura using a 3-mm needlescope with three ports. One patient was male and two were females, and their mean age was 58 years. The patient was placed in the right lateral decubitus position. The first 12-mm port was introduced through the lateral margin of the left rectus abdominis muscle, and the other two 3-mm ports were inserted in the left upper quadrant. NS was performed by a standard technique under the observation of 3.3-mm needlescope. The surgical procedure was successfully completed in all the patients. The mean duration of surgery, intra-operative bleeding volume and post-operative hospital stay were 176 min, 70 ml and 4.7 days, respectively. There were no particular peri-operative complications in spite of dense adhesions or simultaneous laparoscopic procedures. Our method is safe and feasible with low morbidity and without impairing cosmetic benefits.
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Vitiligo is an acquired pigment disorder in which depigmented macules result from the loss of melanocytes from the involved regions of skin and hair. The color dissimilarity on the cosmetically sensitive regions frequently induces quality of life impairment and high willingness to pay for treatment in patients with vitiligo. The Vitiligo Japanese Task Force was organized to overcome this situation and to cooperate with the Vitiligo Global Issues Consensus Conference. This guideline for the diagnosis and treatment of vitiligo in Japan is proposed to improve the circumstances of Japanese individuals with vitiligo. Its contents include information regarding the diagnosis, pathogenesis, evaluation of disease severity and effectiveness of treatment, and evidence-based recommendations for the treatment of vitiligo. The therapeutic algorithm based on the proposed recommendation is designed to cure and improve the affected lesions and quality of life of individuals with vitiligo.
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Vitíligo/terapia , Algoritmos , Diagnóstico Diferencial , Medicina Basada en la Evidencia , Humanos , Japón , Vitíligo/diagnóstico , Vitíligo/epidemiología , Vitíligo/etiologíaRESUMEN
The Japanese Dermatological Association established an advisory committee in 1995 to set up severity scoring systems for atopic dermatitis (AD). Its interim report was published in Japanese in the Japanese Journal of Dermatology (108: 1491-1496, 1998) by Chairman Hikotaro Yoshida. Because of the strong demand for an English version, we have decided to publish the report in English. This prospective study was designed to evaluate the status of 259 AD patients using Method 1, which involves a simple global evaluation of disease severity; Method 2, which involves global evaluation by summing severity scores obtained from five body regions (i.e. the head and neck, anterior and posterior trunks, and upper and lower limbs); Method 3, which consists of both assessment of the extent of involved areas at each of the five body regions and that of the severity scores of each eruption component observed in the most severely affected body region; and Method 4, which consists of the evaluation of only subjective components (daytime pruritus and sleep disturbance). Employing the results obtained with Method 1 as a tentative benchmark, we analyzed its correlation with those of Methods 2, 3 and 4 to statistically assess the validity and reliability of these methods. Method 2, Method 3 and the portion of Method 4 involving evaluation of only the subjective symptom of daytime pruritus but not the sleep disturbance were considered useful in evaluating AD severity.
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Dermatitis Atópica/clasificación , Adolescente , Adulto , Comités Consultivos , Niño , Dermatitis Atópica/complicaciones , Dermatitis Atópica/diagnóstico , Femenino , Humanos , Japón , Lenguaje , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Prurito/etiología , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Trastornos del Sueño-Vigilia/etiología , Sociedades Médicas , Adulto JovenRESUMEN
The Japanese Dermatological Association established an advisory committee in 1995 to develop a severity scoring system for atopic dermatitis (AD). Its interim and concluding reports were published in Japanese in the Japanese Journal of Dermatology (108: 1491-1496, 1998 and 111: 2023-2033, 2001). Because of the strong demand for an English version, we have decided to publish the reports in English. This manuscript is the English version of the concluding report. The interim report suggested that eruption components such as erythema, papule, erosion, crust, excoriation and lichenification with extent of involved areas in five body regions, including the head and neck, anterior and posterior trunks, and upper and lower limbs, were important items for assessing AD severity. Additionally, it was recommended that streamlining of eruption components was mandatory for improving the statistical validity and reliability. The committee members subsequently concentrated their efforts on this task, and finally proposed an Atopic Dermatitis Severity Classification Criteria of the Japanese Dermatological Association.
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Dermatitis Atópica/clasificación , Adulto , Comités Consultivos , Anciano , Dermatitis Atópica/complicaciones , Dermatitis Atópica/diagnóstico , Femenino , Humanos , Japón , Lenguaje , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Prurito/etiología , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Sociedades Médicas , Adulto JovenAsunto(s)
Proteína Morfogenética Ósea 4/metabolismo , Melanocitos/metabolismo , Melanoma/metabolismo , Cresta Neural/metabolismo , Proteínas Proto-Oncogénicas c-ret/metabolismo , Neoplasias Cutáneas/metabolismo , Animales , Línea Celular Tumoral , Regulación hacia Abajo , Ratones , Cresta Neural/citología , Factores de TiempoAsunto(s)
Complejo SIDA Demencia/virología , VIH-1/aislamiento & purificación , Linfoma de Células B Grandes Difuso/virología , Neoplasias Cutáneas/virología , Complejo SIDA Demencia/tratamiento farmacológico , Complejo SIDA Demencia/patología , Tendón Calcáneo , Anciano , Terapia Antirretroviral Altamente Activa , Biopsia , Humanos , Inmunohistoquímica , Pierna , Linfoma de Células B Grandes Difuso/patología , Linfoma de Células B Grandes Difuso/cirugía , Imagen por Resonancia Magnética , Masculino , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Resultado del TratamientoRESUMEN
OBJECTIVES: We examined the prevalence of LAC, aCL antibodies (Abs), anti-beta(2)-glycoprotein I (anti-beta(2)GPI) Abs and anti-phosphatidylserine-prothrombin complex (anti-PS/PT) Abs in patients with regular livedo reticularis or with livedo racemosa to determine whether those Abs correlate with the clinical or serological features. Assuming that a correlation exists, early recognition of the serological features of the cutaneous manifestations may aid in the treatment and prediction of complications. METHODS: We examined the prevalence of LAC, aCL Abs, anti-beta(2)GPI Abs and anti-PS/PT Abs in 143 Japanese patients who presented at our department with regular livedo reticularis or livedo racemosa between 2003 and 2008. LAC was determined according to the guidelines recommended by the Subcommittee on Lupus Anticoagulant/Phospholipid-Dependent Antibodies. Levels of anti-PS/PT, aCL and anti-beta(2)GPI Abs in serum samples taken from patients were measured by specific ELISAs. RESULTS: Anti-PS/PT Abs were detected in 94 (65.7%) of the livedo patients. Further, IgM anti-PS/PT Abs were detected in 90 (62.9%) of the livedo patients. Serum IgM anti-PS/PT Ab levels were significantly higher in livedo racemosa patients compared with regular livedo reticularis (19.2 +/- 17.0 vs 8.93 +/- 8.48 U/ml, P = 0.0013). Cutaneous vasculitis was significantly more prevalent among patients with livedo racemosa compared with regular livedo reticularis (P = 0.0014). Livedo racemosa patients had significantly higher CRP serum levels than regular livedo reticularis patients. Livedo racemosa has a stronger association with skin ulceration and arthralgia compared with regular livedo reticularis. Overall, we found a statistically significant association between cutaneous vasculitis and ischaemic cerebrovascular events in our livedo patients. CONCLUSIONS: We speculate that IgM anti-PS/PT Abs could be implicated in disease susceptibility for livedo racemosa. We further suspect that cutaneous vasculitis could be closely related to pathogenic factors that trigger the development of livedo racemosa. Early detection of cutaneous vasculitis in skin biopsies of livedo patients should be useful for prognostic evaluation, including ischaemic cerebrovascular events.
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Autoanticuerpos/sangre , Fosfatidilserinas/inmunología , Protrombina/inmunología , Enfermedades Cutáneas Vasculares/inmunología , Adulto , Anciano , Biomarcadores/sangre , Biopsia , Femenino , Humanos , Inmunoglobulina M/sangre , Livedo Reticularis/inmunología , Livedo Reticularis/patología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Piel/patología , Enfermedades Cutáneas Vasculares/patologíaRESUMEN
BACKGROUND: Superficial vein thrombophlebitis is the common vascular symptom in Behçet disease and is characterized as erythema nodosum-like eruptions. Some studies have reported the presence of antiphospholipid antibodies (Abs) in patients with Behçet disease. OBSERVATIONS: We measured lupus anticoagulant, anticardiolipin, anti-beta(2)-glycoprotein I, and antiphosphatidylserine-prothrombin complex antibody (Ab) levels in 3 patients with Behçet disease involving superficial vein thrombophlebitis. High levels of IgM antiphosphatidylserine-prothrombin complex Abs were found (mean [SD], 50.3 [43.1] U/mL; normal, <10 U/mL). One of the patients with Behçet disease was positive for both IgM and IgG antiphosphatidylserine-prothrombin complex Abs, and 2 were positive for lupus anticoagulant. Two patients were also positive for IgM anticardiolipin Abs, but the titers were low. In contrast, none of the patients with Behçet disease was positive for IgG anticardiolipin Abs or IgG or IgM anti-beta(2)-glycoprotein I Abs. CONCLUSIONS: A high titer of IgM antiphosphatidylserine-prothrombin complex Abs was found in our patients with Behçet disease involving superficial vein thrombophlebitis. We speculate that there is a relationship between the antiphospholipid Abs, especially IgM antiphosphatidylserine-prothrombin complex Abs, and superficial vein thrombophlebitis complications in Behçet disease. This study suggests that elevated serum antiphosphatidylserine-prothrombin complex Ab levels might play some role in the development of the vascular manifestations in Behçet disease.
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Anticuerpos Antifosfolípidos/sangre , Síndrome de Behçet/sangre , Fosfatidilserinas/inmunología , Protrombina/inmunología , Tejido Subcutáneo/irrigación sanguínea , Tromboflebitis/sangre , Adulto , Síndrome de Behçet/complicaciones , Síndrome de Behçet/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tromboflebitis/etiología , Tromboflebitis/patologíaAsunto(s)
Antivirales/uso terapéutico , Crioglobulinemia/tratamiento farmacológico , Guanina/análogos & derivados , Hepatitis B/complicaciones , Vasculitis/tratamiento farmacológico , Crioglobulinemia/virología , Guanina/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Vasculitis/virologíaAsunto(s)
Anticoagulantes/uso terapéutico , Autoanticuerpos/sangre , Úlcera de la Pierna/tratamiento farmacológico , Ácidos Pipecólicos/uso terapéutico , Trombina/antagonistas & inhibidores , Vasculitis/tratamiento farmacológico , Anciano , Arginina/análogos & derivados , Artritis Reumatoide/complicaciones , Femenino , Humanos , Úlcera de la Pierna/etiología , Úlcera de la Pierna/patología , Fosfatidilserinas/inmunología , Protrombina/inmunología , Piel/patología , Sulfonamidas , Vasculitis/etiología , Vasculitis/patologíaRESUMEN
BACKGROUND: In congenital or acquired dermal melanocytosis, attachment of melanocyte with elastic fiber was shown in electron microscopy of unknown biological meaning. We hypothesize elastin-derived peptide may play a role in activating dermal melanocyte precursors. OBJECTIVES: This study was designed to determine: (i) whether melanocyte precursors express elastin binding protein (EBP); (ii) ontogenic expression of EBP and elastin in murine embryonic skin; (iii) the effects of elastin-derived peptide (VGVAPG) on melanocyte precursors. METHODS: Using immunohistochemistry or Western blot to identify EBP on murine embryonic sections, neural crest cell (NCC) primary culture explants, or two melanocyte precursor cell lines, NCCmelb4 and NCCmelan5. NCC explants or cells were treated with VGVAPG to compare its effect on proliferation, dendrite formation, melanosome maturation and tyrosinase mRNA expression of melanocyte precursors. RESULTS: EBP was immunostained on c-kit+ melanocyte precursors. 67kDa EBP protein was immunoblotted on NCCmelb4 and NCCmelan5 cells. EBP was expressed early at embryonic day (E) 9.5, but elastin appeared later at E12.5 skin. VGVAPG increased DOPA-positive cell number and enhanced their dendrite formation in NCC explants. Electron microscopy showed advanced melanosome maturation in NCC explants or cells treated with VGVAPG. VGVAPG enhanced tyrosinase mRNA expression in NCCmelan5 cells. CONCLUSIONS: Melanocyte precursors expressed EBP. VGVAPG stimulated their melanogenesis and dendrite formation. In the developmental journey interaction between elastin and EBP-expressed melanocyte precursors in embryos happened mainly since the stage of tertiary melanoblasts. These findings first provide biological evidences for the interaction between melanocyte and elastic fiber.
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Células Madre Embrionarias/efectos de los fármacos , Células Madre Embrionarias/metabolismo , Melanocitos/efectos de los fármacos , Melanocitos/metabolismo , Oligopéptidos/farmacología , Receptores de Superficie Celular/metabolismo , Animales , Secuencia de Bases , Línea Celular , Células Cultivadas , Cartilla de ADN/genética , Dendritas/efectos de los fármacos , Dendritas/metabolismo , Dendritas/ultraestructura , Dihidroxifenilalanina/metabolismo , Elastina/farmacología , Células Madre Embrionarias/citología , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Inmunohistoquímica , Melanocitos/citología , Melanosomas/efectos de los fármacos , Melanosomas/metabolismo , Melanosomas/ultraestructura , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Monofenol Monooxigenasa/genética , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
OBJECTIVE: To investigate a possible role of antiphospholipid (aPL) antibodies in adult Henoch-Schönlein purpura (HSP) and cutaneous leukocytoclastic angiitis (CLA). METHODS: We reviewed the records of 30 HSP and 8 CLA adults with an initial cutaneous manifestation of palpable purpura on their lower extremities between 2003 and 2007. Eight microscopic polyangiitis (MPA) patients and 30 healthy persons were recruited as controls. Serum anticardiolipin (aCL), anti-phosphatidylserine-prothrombin complex (anti-PS/PT), and anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibody levels in HSP, CLA, MPA patients, and healthy controls were measured by enzyme-linked immunosorbent assay. RESULTS: Twenty-two HSP patients (73%) were positive for serum IgA aCL antibodies. Nineteen (63%) had IgA anti-PS/PT antibodies and 4 (13%) had IgA anti-beta(2)GPI antibodies. IgA aCL and anti-PS/PT antibodies showed a significant correlation (P = 0.007). Twenty (67%) HSP patients had IgM anti-PS/PT antibodies and 6 (20%) had IgG anti-PS/PT antibodies. Six (75%) CLA patients had IgM anti-PS/PT antibodies and 2 (25%) had IgG anti-PS/PT antibodies. In contrast, aPL antibodies were not found in any MPA patients or normal controls. Serum IgA aCL antibody levels in HSP patients showed a significant correlation with serum IgA and C-reactive protein (CRP) levels (P = 0.030 and 0.039, respectively). A positive correlation between CRP and serum IgA anti-PS/PT antibody levels was observed in HSP patients (P = 0.023). Serum IgA aCL antibody levels were also significantly associated with proteinuria according to urinalysis (P = 0.024). CONCLUSION: Serum levels of IgA aCL and anti-PS/PT antibodies were elevated in adult HSP, suggesting that serum IgA antibodies may play some role in adult HSP. IgA aCL and/or anti-PS/PT antibodies could serve as markers for adult HSP and should be monitored as an indicator of adult HSP activity. Small-vessel vasculitis could be dependently associated with the presence of IgM anti-PS/PT antibodies. These findings suggest that aPL antibodies are closely related to the pathogenic factors that trigger the development of vasculitis.
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Anticuerpos Antifosfolípidos/sangre , Vasculitis por IgA/sangre , Vasculitis Leucocitoclástica Cutánea/sangre , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Extramedullary hematopoiesis (EMH) is a relatively rare, but well-documented, manifestation of chronic myeloproliferative disorders. Microscopically, foci of EMH consist of erythroid and myeloid precursors intermixed with megakaryocytes. It typically occurs in the spleen and liver, but very occasionally manifests as cutaneous EMH. We report a 76-year-old Japanese man with cutaneous EMH arising from myelodysplastic syndrome associated with myelofibrosis. His cutaneous manifestations showed multiple skin-colored firm nodules over the head, trunk, and extremities. We detected high plasma levels of transforming growth factor (TGF)-beta1 in our patient. Immunohistochemical analysis of the skin biopsy sample revealed TGF-beta1 overexpression in immature hematopoietic cells and dermal fibroblasts within the cutaneous EMH mass of the dermis. These findings suggest that TGF-beta could play some role in the onset of cutaneous EMH. Five months after his first visit to our dermatologic clinic, the patient developed bone-marrow failure and died. Based on our observations, accelerated malignancy in the bone marrow should be considered in any patient with cutaneous EMH. It is presumed that TGF-beta released from hematopoietic cells within the cutaneous EMH play a critical role in the activation of hematologic malignancy.
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Hematopoyesis Extramedular , Síndromes Mielodisplásicos/fisiopatología , Mielofibrosis Primaria/fisiopatología , Factor de Crecimiento Transformador beta/biosíntesis , Anciano , Humanos , Masculino , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/patología , Mielofibrosis Primaria/etiología , Mielofibrosis Primaria/patología , Piel/patología , Fenómenos Fisiológicos de la PielRESUMEN
Genes encoding Kit and the Kit ligand (KL) play essential roles in the differentiation of melanoblasts. We previously established three immortal but distinct cell populations of mouse neural crest (NC) cells. NCCmelb4M5 cells do not express Kit and grow independently of KL; they have the potential to differentiate into NCCmelb4 cells, which are Kit-positive melanocyte precursors. NCCmelan5 cells show the characteristics of differentiated melanocytes. All three cell lines demonstrated bone morphogenetic protein (BMP) receptor expression. BMP-4 upregulated Kit protein and mRNA expression in most immature NCCmelb4M5 cells. Noggin, a BMP-4 antagonist, dramatically decreased the Kit expression induced by BMP-4. Western blot analysis revealed that extrinsic BMP-4 leads to the phosphorylation of Smads in NCCmelb4M5 cells. Using transfected Kit-promoter reporter, we showed BMP-4 could activate Kit promoter in transfected NCCmelb4M5 cells. We conclude that BMP-4 is active and is involved in the regulation of Kit expression on most immature melanocyte precursors. We further investigated the influence of BMP-4 in vitro using primary NC cells cultured from wild-type mice. Addition of BMP-4 to the medium increased the number of Kit-positive cells compared to diluent-treated controls. We have identified BMP-4 as an important factor for prenatal Kit-negative melanoblasts just prior to entering the Kit-dependent cycle of melanogenesis.
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Proteínas Morfogenéticas Óseas/metabolismo , Melaninas/biosíntesis , Melanocitos/fisiología , Proteínas Proto-Oncogénicas c-kit/metabolismo , Células Madre/fisiología , Animales , Western Blotting , Proteína Morfogenética Ósea 4 , Proteínas Morfogenéticas Óseas/farmacología , Diferenciación Celular/fisiología , División Celular/fisiología , Células Cultivadas , Medios de Cultivo/farmacología , Femenino , Expresión Génica/efectos de los fármacos , Expresión Génica/fisiología , Masculino , Melanocitos/citología , Melanocitos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Embarazo , Regiones Promotoras Genéticas/fisiología , Proteínas Proto-Oncogénicas c-kit/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína Smad1/metabolismo , Proteína Smad5/metabolismo , Proteína Smad8/metabolismo , Células Madre/citología , Células Madre/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/fisiologíaRESUMEN
Melanosomes are unique membrane-bound organelles specialized for the synthesis and distribution of melanin. Mechanisms involved in the trafficking of proteins to melanosomes and in the transport of mature pigmented melanosomes to the dendrites of melanocytic cells are being characterized, but details about those processes during early stages of melanosome maturation are not well understood. Early melanosomes must remain in the perinuclear area until critical components are assembled. In this study, we characterized the processing of two distinct melanosomal proteins, tyrosinase (TYR) and Pmel17, to elucidate protein processing in early or late steps of the secretory pathway, respectively, and to determine mechanisms underlying the subcellular localization and transport of early melanosomes. We used immunological, biochemical, and molecular approaches to demonstrate that the movement of early melanosomes in the perinuclear area depends primarily on microtubules but not on actin filaments. In contrast, the trafficking of TYR and Pmel17 depends on cytoplasmic dynein and its interaction with the spectrin/ankyrin system, which is involved with the sorting of cargo from the plasma membrane. These results provide important clues toward understanding the processes involved with early events in melanosome formation and transport.
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Dineínas/fisiología , Melanosomas/fisiología , Glicoproteínas de Membrana/metabolismo , Monofenol Monooxigenasa/metabolismo , Espectrina/fisiología , Actinas/fisiología , Proteínas Adaptadoras Transductoras de Señales/análisis , Proteína de Señalización Agouti/fisiología , Animales , Transporte Biológico , Células Cultivadas , Dihidroxifenilalanina/análisis , Aparato de Golgi/metabolismo , Humanos , Cinesinas/análisis , Melanoma/metabolismo , Melanosomas/ultraestructura , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Microtúbulos/fisiología , Transporte de Proteínas , Espectrina/análisis , Antígeno gp100 del Melanoma , Proteínas de Unión al GTP rab/análisis , Proteínas rab27 de Unión a GTPRESUMEN
BACKGROUND: We have established two immature melanocyte cell lines from murine neural crest cells. NCC-E3 cells have Stage II melanosomes and express tyrosinase while in NCCmelb4 cells, the melanosomes remain at Stage I and tyrosinase is not expressed. These cell lines may be useful in studying the differentiation of melanocyte precursors. OBJECTIVE: To perform proteomic analysis of the two cell lines to identify proteins related to and possibly responsible for their different maturation stages. METHODS: Western blotting, two-dimensional differential image gel electrophoresis (2D-DIGE), liquid chromatography-tandem mass spectrometry (LC-MS/MS), real-time PCR analysis and RNA interference using siRNA were employed in this study. RESULTS: Western blotting revealed that the processed form of gp100, which is specific for Stage II melanosomes, is expressed in NCC-E3 cells but not in NCCmelb4 cells. 2D-DIGE identified two protein spots showing 4.06- and 2.22-fold increases in NCC-E3 cells compared to NCCmelb4 cells. Analysis of those proteins by LC-MS/MS revealed that the former was calreticulin and the latter was BiP/GRP78. When calreticulin mRNA expression in NCC-E3 cells was blocked by siRNA, tyrosinase protein was abolished and DOPA-reactivity was decreased, although tyrosinase mRNA was abundantly expressed after the same treatment. CONCLUSION: Calreticulin, a lectin chaperone, is an essential molecule for the processing of tyrosinase in murine melanocytes. The role of molecular chaperones such as calreticulin should be considered when analyzing the mechanism(s) of melanocyte differentiation.