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1.
Sci Rep ; 14(1): 10251, 2024 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-38704512

RESUMEN

Mesenchymal stem cells (MSCs) exert their anti-inflammatory and anti-fibrotic effects by secreting various humoral factors. Interferon-gamma (IFN-γ) can enhance these effects of MSCs, and enhancement of regulatory T (Treg) cell induction is thought to be an underlying mechanism. However, the extent to which Treg cell induction by MSCs pretreated with IFN-γ (IFN-γ MSCs) ameliorates renal fibrosis remains unknown. In this study, we investigated the effects of Treg cell induction by IFN-γ MSCs on renal inflammation and fibrosis using an siRNA knockdown system. Administration of IFN-γ MSCs induced Treg cells and inhibited infiltration of inflammatory cells in ischemia reperfusion injury (IRI) rats more drastically than control MSCs without IFN-γ pretreatment. In addition, administration of IFN-γ MSCs more significantly attenuated renal fibrosis compared with control MSCs. Indoleamine 2,3-dioxygenase (IDO) expression levels in conditioned medium from MSCs were enhanced by IFN-γ pretreatment. Moreover, IDO1 knockdown in IFN-γ MSCs reduced their anti-inflammatory and anti-fibrotic effects in IRI rats by reducing Treg cell induction. Our findings suggest that the increase of Treg cells induced by enhanced secretion of IDO by IFN-γ MSCs played a pivotal role in their anti-fibrotic effects. Administration of IFN-γ MSCs may potentially be a useful therapy to prevent renal fibrosis progression.


Asunto(s)
Fibrosis , Indolamina-Pirrol 2,3,-Dioxigenasa , Interferón gamma , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Linfocitos T Reguladores , Animales , Interferón gamma/metabolismo , Linfocitos T Reguladores/inmunología , Células Madre Mesenquimatosas/metabolismo , Ratas , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Masculino , Trasplante de Células Madre Mesenquimatosas/métodos , Riñón/patología , Riñón/efectos de los fármacos , Daño por Reperfusión/inmunología , Enfermedades Renales/terapia , Enfermedades Renales/patología , Ratas Sprague-Dawley
2.
Acta Cytol ; 67(5): 539-549, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37497898

RESUMEN

INTRODUCTION: Lobular endocervical glandular hyperplasia (LEGH) is a benign lesion; however, it is considered to be the origin of gastric-type adenocarcinoma in the uterine cervix, and early diagnosis is important. At Shinshu University Hospital, screening of LEGH cells is based on the difference in color tone of cytoplasmic mucin on Papanicolaou staining and detection of gastric mucin using HIK1083-labeled latex agglutination assay. However, it is sometimes difficult to distinguish LEGH cells with subtle nuclear atypia from endocervical (EC) cells. METHODS: We calculated the Gabor filter features (mean signal value, standard deviation, skewness, kurtosis) from the nuclei of cytological specimens in EC cells (37 cases) and LEGH cells (33 cases) using microscopic images, and we performed statistical analysis and discriminant analysis by linear support vector machine (LSVM) using these features. A Gabor filter is a linear filter defined as a mathematical representation of the mammalian visual system. Gabor filters with three wavelengths and eight angles were used for analysis. RESULTS: Gabor filter features in EC cells were higher than in LEGH cells, demonstrating that the gradient of LEGH cell nuclei was milder than that of EC cell nuclei. The accuracy calculated using all Gabor filters was 91.0% and the accuracy of four Gabor filters (λ = 2/3π and θ = 0°, 45°, 90°, 135°) was 88.9%. High accuracy with low computation costs was achieved by reducing the number of features used for LSVM. CONCLUSION: The application of a Gabor filter with convolutional processing resulted in the edges of LEGH cells being slightly rough and thick, whereas those of EC cells were fine and thin. Thus, it is thought that the frequency of abrupt gradients of pixels was higher in EC cells than in LEGH cells, and the gradient of chromatin distribution in LEGH cell nuclei was milder than that in EC cell nuclei. It was possible to evaluate nuclear findings of EC and LEGH cells objectively by quantifying morphological features of nuclei using Gabor filters. It was possible to differentiate EC cells from LEGH cells using LSVM using Gabor filter features.


Asunto(s)
Adenocarcinoma , Neoplasias del Cuello Uterino , Femenino , Humanos , Hiperplasia/patología , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Análisis Discriminante , Cuello del Útero/patología , Núcleo Celular/patología , Adenocarcinoma/diagnóstico , Adenocarcinoma/patología
3.
BMC Cancer ; 23(1): 478, 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37237373

RESUMEN

BACKGROUND: ADP-ribosylation factor-like protein 4 C (ARL4C) is a member of the ARF small GTP-binding protein subfamily. The ARL4C gene is highly expressed in colorectal cancer (CRC). ARL4C protein promotes cell motility, invasion, and proliferation. METHODS: We investigated the characteristics of ARL4C by comparing its expression at the invasion front and relationships with clinicopathological data using RNAscope, a highly sensitive RNA in situ method. RESULTS: In all cases, ARL4C expression was observed in cancer stromal cells and cancer cells. ARL4C expression in cancer cells was localized at the invasion front. In cancer stromal cells, ARL4C expression was significantly stronger in cases with high-grade tumor budding than in cases with low-grade tumor budding (P = 0.0002). Additionally, ARL4C expression was significantly increased in patients with high histological grade compared with those with low histological grade (P = 0.0227). Furthermore, ARL4C expression was significantly stronger in lesions with the epithelial-to-mesenchymal transition (EMT) phenotype compared with the non-EMT phenotype (P = 0.0289). In CRC cells, ARL4C expression was significantly stronger in cells that had the EMT phenotype compared with those with a non-EMT phenotype (P = 0.0366). ARL4C expression was significantly higher in cancer stromal cells than in CRC cells (P < 0.0001). CONCLUSION: Our analysis reinforces the possibility that ARL4C expression worsens the prognosis of patients with CRC. Further elucidation of the function of ARL4C is desired.


Asunto(s)
Transformación Celular Neoplásica , Neoplasias Colorrectales , Humanos , Pronóstico , Fenotipo , Transformación Celular Neoplásica/genética , Neoplasias Colorrectales/patología , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Movimiento Celular/genética , Proliferación Celular/genética , Línea Celular Tumoral , Factores de Ribosilacion-ADP/genética , Factores de Ribosilacion-ADP/metabolismo
4.
Vox Sang ; 118(1): 41-48, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36224113

RESUMEN

BACKGROUND AND OBJECTIVES: Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are common, although their mechanisms remain unclear. Immunoglobulin E (IgE)-mediated type I hypersensitivity may be involved in the pathogenesis of ATR. A basophil activation test (BAT) may help elucidate this process. MATERIALS AND METHODS: The BAT was based on peripheral blood samples from paediatric patients with a haematological or oncological disease and on samples of residual blood products transfused in each case. Dasatinib was used to evaluate whether basophil activation was mediated by an IgE-dependent pathway. RESULTS: Twenty-seven patients with and 19 patients without ATR/FNHTR were included in this study, respectively. The median BAT values associated with ATR- (n = 41) and FNHTR-causing (n = 5) blood products were 22.1% (range = 6.1%-77.0%) and 27.8% (range = 15.2%-47.8%), respectively, which were higher than the median value of 8.5% (range = 1.1%-40.9%) observed in blood products without a transfusion reaction. Dasatinib suppressed basophil activity. BAT values were comparable in patients with ATR regardless of severity. Meanwhile, BAT values analysed with blood products non-causal for ATR/FNHTR were higher in patients with ATR/FNHTR than in those without. CONCLUSION: The IgE-mediated type I hypersensitivity may be involved in the pathogenesis of ATR and FNHTR. BAT analyses may help elucidate the underlying mechanisms and identify patients at risk.


Asunto(s)
Hipersensibilidad Inmediata , Hipersensibilidad , Reacción a la Transfusión , Humanos , Niño , Prueba de Desgranulación de los Basófilos , Dasatinib , Hipersensibilidad/complicaciones , Reacción a la Transfusión/etiología , Hipersensibilidad Inmediata/complicaciones , Basófilos , Inmunoglobulina E
5.
Stem Cell Res Ther ; 12(1): 472, 2021 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-34425892

RESUMEN

BACKGROUND: Mesenchymal stem cells (MSCs) repair injured tissue in a paracrine manner. To enhance their therapeutic properties, preconditioning with various factors has been researched. We have previously showed that MSCs cultured in serum-free medium (SF-MSCs) promote their immunosuppressive ability, thereby enhancing their anti-fibrotic effect. Here, we examined whether serum-free medium and hypoxic preconditioning synergistically enhance the therapeutic effects of MSCs on renal fibrosis in rats with ischemia-reperfusion injury (IRI). METHODS: SF-MSCs were incubated under 1% O2 conditions (hypo-SF-MSCs) or 21% O2 conditions (normo-SF-MSCs) for 24 h before collection. After IRI procedure, hypo-SF-MSCs or normo-SF-MSCs were injected through the abdominal aorta. At 7 or 21 days post-injection, the rats were killed and their kidneys were collected to evaluate inflammation and fibrosis. In in vitro experiments, we investigated whether hypo-SF-MSCs enhanced secretion of anti-fibrotic humoral factors using transforming growth factor (TGF)-ß1-stimulated HK-2 cells incubated with conditioned medium from hypo-SF-MSCs or normo-SF-MSCs. RESULTS: Normo-SF-MSCs showed attenuation of senescence, which increased their proliferative capacity. Although no significant difference in cellular senescence was found between normo-SF-MSCs and hypo-SF-MSCs, hypo-SF-MSCs further increased their proliferative capacity compared with normo-SF-MSCs. Additionally, administration of hypo-SF-MSCs more strongly ameliorated renal fibrosis than that of normo-SF-MSCs. Moreover, although hypo-SF-MSCs strongly attenuated infiltration of inflammatory cells compared with the control rats, which were treated with PBS, this attenuation was almost equal between normo-SF-MSCs and hypo-SF-MSCs. In vitro experiments revealed that hypo-SF-MSCs more significantly inhibited transforming growth factor (TGF)-ß/Smad signaling compared with normo-SF-MSCs. Moreover, hypoxic preconditioning increased hepatocyte growth factor (HGF) secretion even under serum-free conditions, whereas knockdown of HGF in hypo-SF-MSCs attenuated inhibition of TGF-ß/Smad signaling. CONCLUSIONS: These results indicate that administration of ex vivo-expanded, hypoxia-preconditioned SF-MSCs may be a useful cell therapy to prevent renal fibrosis.


Asunto(s)
Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Animales , Medios de Cultivo Condicionados/farmacología , Fibrosis , Hipoxia , Ratas
6.
Int J Mol Sci ; 22(8)2021 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-33920714

RESUMEN

Mesenchymal stem cells (MSCs) are a potential therapeutic tool for preventing the progression of acute kidney injury (AKI) to chronic kidney disease (CKD). Herein, we investigated the localization and maintenance of engrafted human bone marrow-derived MSCs in rats subjected to a renal ischemia-reperfusion injury (IRI) and compared the effectiveness of two intravascular injection routes via the renal artery or inferior vena cava. Renal artery injection of MSCs was more effective than intravenous injection at reducing IRI-induced renal fibrosis. Additionally, MSCs injected through the renal artery persisted in injured kidneys for over 21 days, whereas MSCs injected through the inferior vena cava survived for less than 7 days. This difference may be attributed to the antifibrotic effects of MSCs. Interestingly, MSCs injected through the renal artery were localized primarily in glomeruli until day 3 post-IRI, and they decreased in number thereafter. In contrast, the number of MSCs localized in tubular walls, and the interstitium increased gradually until day 21 post-IRI. This localization change may be related to areas of damage caused by IRI because ischemia-induced AKI leads to tubular cell damage. Taken together, these findings suggest renal artery injection of MSCs may be useful for preventing the progression of AKI to CKD.


Asunto(s)
Lesión Renal Aguda/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Daño por Reperfusión/terapia , Animales , Células Cultivadas , Humanos , Inyecciones Intraarteriales/métodos , Masculino , Ratas , Ratas Sprague-Dawley
7.
Sci Rep ; 11(1): 850, 2021 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-33441701

RESUMEN

Mesenchymal stem cells (MSCs) administered for therapeutic purposes can be activated by interferon-γ (IFN-γ) secreted from natural killer cells in injured tissues and exert anti-inflammatory effects. These processes require a substantial period of time, leading to a delayed onset of MSCs' therapeutic effects. In this study, we investigated whether pretreatment with IFN-γ could potentiate the anti-fibrotic ability of MSCs in rats with ischemia-reperfusion injury (IRI) and unilateral ureter obstruction. Administration of MSCs treated with IFN-γ strongly reduced infiltration of inflammatory cells and ameliorated interstitial fibrosis compared with control MSCs without IFN-γ treatment. In addition, conditioned medium obtained from IFN-γ-treated MSCs decreased fibrotic changes in cultured cells induced by transforming growth factor-ß1 more efficiently than that from control MSCs. Most notably, secretion of prostaglandin E2 from MSCs was significantly increased by treatment with IFN-γ. Increased prostaglandin E2 in conditioned medium obtained from IFN-γ-treated MSCs induced polarization of immunosuppressive CD163 and CD206-positive macrophages. In addition, knockdown of prostaglandin E synthase weakened the anti-fibrotic effects of MSCs treated with IFN-γ in IRI rats, suggesting the involvement of prostaglandin E2 in the beneficial effects of IFN-γ. Administration of MSCs treated with IFN-γ might represent a promising therapy to prevent the progression of renal fibrosis.


Asunto(s)
Interferón gamma/farmacología , Enfermedades Renales/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Células Cultivadas , Medios de Cultivo Condicionados , Dinoprostona/metabolismo , Fibrosis/terapia , Riñón/patología , Enfermedades Renales/tratamiento farmacológico , Células Asesinas Naturales/metabolismo , Macrófagos/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Receptores de Superficie Celular/metabolismo , Daño por Reperfusión/fisiopatología , Daño por Reperfusión/terapia , Obstrucción Ureteral/fisiopatología , Obstrucción Ureteral/terapia
8.
Diagn Cytopathol ; 48(8): 724-735, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32374944

RESUMEN

BACKGROUND: Lobular endocervical glandular hyperplasia (LEGH) is a disease considered to be the origin of tumorigenesis of minimal deviation adenocarcinoma, which has characteristic expression in the gastric pyloric mucosa. It is difficult to diagnose by nuclear findings because of lower nuclear atypia. In this study, nuclei of endocervical (EC) and LEGH cells were digitized, and nuclear information was quantified from nuclear images and objectively evaluated using a computer. We examined whether it is possible to distinguish between EC and LEGH cells, which is difficult by human eyes. METHODS: Signal intensity, morphological features, Otsu thresholding technique and gray-level co-occurrence matrix (GLCM) features were calculated from nuclei of EC and LEGH cells on cytology microscopic images. Then, discriminant analysis was performed using the significant difference test and linear support vector machine (LSVM). RESULTS: GLCM features in LEGH cells were higher than those in EC cells. The nuclei of LEGH cells had a higher frequency of signal value pairs with a larger signal value difference than that of EC cells. Therefore, LEGH cell nuclei are thought to have more chromatin granules, and the chromatin is coarse and granular. Moreover, in the LSVM discriminant analysis, the accuracy of GLCM calculated using these features was 85.4%. CONCLUSION: In this study, GLCM accurately demonstrated the nuclear chromatin distribution and coarseness. Discriminant analysis of EC and LEGH cells using GLCM features is useful.


Asunto(s)
Adenocarcinoma/diagnóstico , Cromatina , Interpretación de Imagen Asistida por Computador/métodos , Máquina de Vectores de Soporte , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Anciano , Análisis Discriminante , Femenino , Humanos , Hiperplasia/diagnóstico , Persona de Mediana Edad , Prueba de Papanicolaou/métodos
9.
Stem Cell Res Ther ; 11(1): 130, 2020 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-32197638

RESUMEN

BACKGROUND: Mesenchymal stem cells (MSCs) have been reported to promote the regeneration of injured tissue via their paracrine abilities, which are enhanced by hypoxic preconditioning. In this study, we examined the therapeutic efficacy of hypoxia-preconditioned MSCs on renal fibrosis and inflammation in rats with ischemia-reperfusion injury (IRI). METHODS: MSCs derived from rats and humans were incubated in 1% O2 conditions (1%O2 MSCs) for 24 h. After IRI, 1%O2 MSCs or MSCs cultured under normoxic conditions (21%O2 MSCs) were injected through the abdominal aorta. At 7 or 21 days post-injection, the rats were sacrificed and their kidneys were analyzed. In in vitro experiments, we examined whether 1%O2 MSCs enhanced the ability to produce anti-fibrotic humoral factors using transforming growth factor (TGF)-ß1-stimulated HK-2 cells incubated with conditioned medium from MSCs. RESULTS: Administration of rat 1%O2 MSCs (1%O2 rMSCs) attenuated renal fibrosis and inflammation more significantly than rat 21%O2 MSCs. Notably, human 1%O2 MSCs (1%O2 hMSCs) also attenuated renal fibrosis to the same extent as 1%O2 rMSCs. Flow cytometry showed that 1%O2 hMSCs did not change human leukocyte antigen expression. Further in vitro experiments revealed that conditioned medium from 1%O2 MSCs further suppressed TGF-ß1-induced fibrotic changes in HK-2 cells compared with 21%O2 MSCs. Hypoxic preconditioning enhanced vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) secretion. Interestingly, VEGF knockdown in 1%O2 MSCs attenuated HGF secretion and the inhibition of TGF-ß1-induced fibrotic changes in HK-2 cells. In addition, VEGF knockdown in 1%O2 hMSCs reduced the anti-fibrotic effect in IRI rats. CONCLUSIONS: Our results indicate that hypoxia-preconditioned MSCs are useful as an allogeneic transplantation cell therapy to prevent renal fibrosis and inflammation.


Asunto(s)
Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Animales , Hipoxia de la Célula , Células Cultivadas , Fibrosis , Humanos , Inflamación , Isquemia , Riñón/irrigación sanguínea , Riñón/patología , Ratas , Reperfusión , Daño por Reperfusión/terapia , Factor A de Crecimiento Endotelial Vascular
10.
Diagn Cytopathol ; 47(6): 553-563, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30761780

RESUMEN

BACKGROUND: Lobular endocervical glandular hyperplasia (LEGH) was first described by Nucci et al. in 1999 and is believed to be a precancerous lesion of minimal deviation adenocarcinoma and gastric-type adenocarcinoma in the uterine cervix. LEGH lesions do not always exhibit apparent cellular and structural atypia, so are difficult to distinguish from normal endocervical cells (EC cells) with cytological examination. Therefore, we often struggle to make a definite diagnosis of LEGH. METHODS: We used microscopy images of cytological specimens that were diagnosed as EC cells and LEGH cells. Signal intensity in whole nuclear area and in heterochromatin and euchromatin regions, euchromatin area ratio, and nuclear morphological features were quantified in each cell nucleus of the cases. Statistical analyses were conducted to determine statistical significance. Finally, we performed linear support vector machine (LSVM) modeling as a discriminant analysis using the quantified features. RESULTS: Signal intensity in whole nuclear area, and heterochromatin and euchromatin regions of EC cell nuclei were higher than that of the LEGH cell nuclei. Morphologically, EC cell nuclei were larger than LEGH cell nuclei, and nuclei of LEGH cells had irregular nuclear respectively membrane structure and an elongated shape. The LSVM accuracy of 10-fold cross validation and leave-one-case-out cross-validation (LOCOCV) using all measured features were 84.7% to 89.3% and 78.6% to 86.0%, respectively. CONCLUSIONS: The LVSM analysis using features extracted from signal intensity and morphological analysis was useful for discrimination of EC cells vs LEGH cells. We therefore believe that this image analysis method could be used for early detection of LEGH.


Asunto(s)
Eucromatina/química , Heterocromatina/química , Procesamiento de Imagen Asistido por Computador , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Núcleo Celular/patología , Diagnóstico Diferencial , Femenino , Humanos , Hiperplasia , Reproducibilidad de los Resultados
11.
Appl Environ Microbiol ; 70(2): 1135-44, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14766598

RESUMEN

In organisms other than higher plants, family 19 chitinase was first discovered in Streptomyces griseus HUT6037, and later, the general occurrence of this enzyme in Streptomyces species was demonstrated. In the present study, the distribution of family 19 chitinases in the class Actinobacteria and the phylogenetic relationship of Actinobacteria family 19 chitinases with family 19 chitinases of other organisms were investigated. Forty-nine strains were chosen to cover almost all the suborders of the class Actinobacteria, and chitinase production was examined. Of the 49 strains, 22 formed cleared zones on agar plates containing colloidal chitin and thus appeared to produce chitinases. These 22 chitinase-positive strains were subjected to Southern hybridization analysis by using a labeled DNA fragment corresponding to the catalytic domain of ChiC, and the presence of genes similar to chiC of S. griseus HUT6037 in at least 13 strains was suggested by the results. PCR amplification and sequencing of the DNA fragments corresponding to the major part of the catalytic domains of the family 19 chitinase genes confirmed the presence of family 19 chitinase genes in these 13 strains. The strains possessing family 19 chitinase genes belong to 6 of the 10 suborders in the order Actinomycetales, which account for the greatest part of the Actinobacteria: Phylogenetic analysis suggested that there is a close evolutionary relationship between family 19 chitinases found in Actinobacteria and plant class IV chitinases. The general occurrence of family 19 chitinase genes in Streptomycineae and the high sequence similarity among the genes found in Actinobacteria suggest that the family 19 chitinase gene was first acquired by an ancestor of the Streptomycineae and spread among the Actinobacteria through horizontal gene transfer.


Asunto(s)
Actinobacteria/clasificación , Actinobacteria/enzimología , Quitinasas , Filogenia , Actinobacteria/genética , Secuencia de Aminoácidos , Quitinasas/química , Quitinasas/genética , Quitinasas/metabolismo , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADN
12.
Microbiology (Reading) ; 145 ( Pt 12): 3353-3363, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10627034

RESUMEN

Chitinase C from Streptomyces griseus HUT6037, described in 1997, is the first family 19 chitinase found in an organism other than higher plants. In this study, some properties of chitinase C were compared with those of family 18 bacterial chitinases, and the distribution of family 19 chitinases in Streptomyces species was investigated. The specific hydrolysing activity of chitinase C against soluble and insoluble chitinous substrates was markedly higher than those of bacterial family 18 chitinases. Chitinase C exhibited marked antifungal activity, whereas the other bacterial chitinases examined had no antifungal activity. Chitinase C was insensitive to allosamidin, whereas the family 18 bacterial chitinases were sensitive. Taking advantage of this insensitivity to allosamidin, a search was made for family 19 chitinases in various Streptomyces species. Chitinases insensitive to allosamidin were detected in the culture supernatants of all tested Streptomyces species. Southern hybridization analysis using a labelled DNA fragment corresponding to the catalytic domain of chitinase C strongly suggested that these species have genes similar to the chiC gene of S. griseus HUT6037. DNA fragments corresponding to the major part of the catalytic domains were amplified by PCR. The amplified fragments encoded amino acid sequences very similar to that of the corresponding region of chitinase C. Therefore, it was concluded that Streptomyces species generally possess family 19 chitinases which are very similar to chitinase C. Comparison of their amino acid sequences with those of plant family 19 chitinases revealed that Streptomyces family 19 chitinases are class IV type in terms of the presence and positions of deletions of amino acid sequences which are characteristic of plant class IV chitinases.


Asunto(s)
Quitinasas , Streptomyces/enzimología , Acetilglucosamina/análogos & derivados , Acetilglucosamina/farmacología , Secuencia de Aminoácidos , Antifúngicos/farmacología , Southern Blotting , Quitinasas/química , Quitinasas/genética , Quitinasas/metabolismo , Quitinasas/farmacología , Inhibidores Enzimáticos/farmacología , Escherichia coli/enzimología , Escherichia coli/genética , Hongos/efectos de los fármacos , Amplificación de Genes , Datos de Secuencia Molecular , Filogenia , Proteínas de Plantas , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Streptomyces/genética , Trisacáridos/farmacología
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