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1.
Proc Natl Acad Sci U S A ; 121(19): e2400903121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38683992

RESUMEN

The IL-17 pathway displays remarkably diverse functional modes between different subphyla, classes, and even orders, yet its driving factors remains elusive. Here, we demonstrate that the IL-17 pathway originated through domain shuffling between a Toll-like receptor (TLR)/IL-1R pathway and a neurotrophin-RTK (receptor-tyrosine-kinase) pathway (a Trunk-Torso pathway). Unlike other new pathways that evolve independently, the IL-17 pathway remains intertwined with its donor pathways throughout later evolution. This intertwining not only influenced the gains and losses of domains and components in the pathway but also drove the diversification of the pathway's functional modes among animal lineages. For instance, we reveal that the crustacean female sex hormone, a neurotrophin inducing sex differentiation, could interact with IL-17Rs and thus be classified as true IL-17s. Additionally, the insect prothoracicotropic hormone, a neurotrophin initiating ecdysis in Drosophila by binding to Torso, could bind to IL-17Rs in other insects. Furthermore, IL-17R and TLR/IL-1R pathways maintain crosstalk in amphioxus and zebrafish. Moreover, the loss of the Death domain in the pathway adaptor connection to IκB kinase and stress-activated protein kinase (CIKSs) dramatically reduced their abilities to activate nuclear factor-kappaB (NF-κB) and activator protein 1 (AP-1) in amphioxus and zebrafish. Reinstating this Death domain not only enhanced NF-κB/AP-1 activation but also strengthened anti-bacterial immunity in zebrafish larvae. This could explain why the mammalian IL-17 pathway, whose CIKS also lacks Death, is considered a weak signaling activator, relying on synergies with other pathways. Our findings provide insights into the functional diversity of the IL-17 pathway and unveil evolutionary principles that could govern the pathway and be used to redesign and manipulate it.


Asunto(s)
Interleucina-17 , Transducción de Señal , Receptores Toll-Like , Animales , Interleucina-17/metabolismo , Receptores Toll-Like/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Factores de Crecimiento Nervioso/genética , Receptores de Interleucina-1/metabolismo , Receptores de Interleucina-1/genética , Evolución Molecular , Receptores de Interleucina-17/metabolismo , Receptores de Interleucina-17/genética
2.
Clin Cosmet Investig Dermatol ; 17: 247-252, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38314146

RESUMEN

Acquired digital fibrokeratoma (ADF) is rare in clinical practice and is easily misdiagnosed. Herein, 5 cases of patients (3 males and 2 females) with ADF are reported. The mean age at onset was 42.6 years, and the mean disease duration was 3 years. Four patients had ADF on the hands, and 1 patient had ADF on the foot. The clinical manifestations were all solitary, skin-colored papules, with a firm texture and smooth surface, protruding from the skin surface. In 3 patients, ADF manifested as columnar protrusions, and in 2 patients, ADF manifested as dome-shaped protrusions. For all 5 patients, the diameters of the lesions were <1 cm. Clinically, all 5 patients were misdiagnosed (ie, eccrine poroma (EP), common warts, rudimentary polydactyly, pyogenic granuloma (PG), and acral fibroma). All cases of ADF were confirmed by histopathology. The histopathological manifestations of ADF were as follows: finger-like protrusions on the skin surface; collagen fiber bundles running vertically to the epidermis seen in the dermis; and thick red-stained collagen fibers connected with the normal dermal connective tissue below. All 5 patients underwent surgical resection; the distance between the incision margin and the edge of the tumor was 2-3 mm, and the surgical depth was the deep dermis. No recurrence was observed in more than half a year of follow-up after surgery.

3.
J Cosmet Dermatol ; 23(5): 1583-1587, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38279518

RESUMEN

OBJECTIVE: By presenting a case study on multiple instances of Bowen's disease and the consistent use of narrow-band ultraviolet B (NB-UVB) phototherapy over a three-year period, our aim is to enhance the comprehension of domestic clinicians regarding the disease. Additionally, we seek to review existing literature, encouraging dermatologists to consider clinical secondary primary lesion diagnoses. METHOD: Our approach involves analyzing a diagnosed case of multiple Bowen's disease, examining clinical manifestations, histopathology, imaging results, and treatment methods related to NB-UVB phototherapy. We aim to facilitate discussion and understanding through a comprehensive literature analysis. RESULTS: An elderly male with a 30-year history of psoriasis vulgaris initiated continuous NB-UVB therapy three years ago. A year later, he developed red patches and plaques with distinct borders and scaly surfaces on his face, trunk, lower extremities, and scrotum. Histopathological examination confirmed Bowen's disease. Treatment involved liquid nitrogen cryotherapy, with no recurrence observed during the one-year follow-up. CONCLUSION: This case highlights that Bowen's disease, typically solitary, can manifest as multiple instances, especially in individuals with a history of psoriasis vulgaris. While NB-UVB stands as the primary treatment for psoriasis vulgaris, caution is warranted due to the potential risk of skin tumor induction with prolonged high-dose usage. Clinicians should be vigilant in monitoring and assessing the long-term implications of such therapies.


Asunto(s)
Enfermedad de Bowen , Psoriasis , Neoplasias Cutáneas , Terapia Ultravioleta , Humanos , Enfermedad de Bowen/terapia , Enfermedad de Bowen/diagnóstico , Enfermedad de Bowen/patología , Masculino , Terapia Ultravioleta/efectos adversos , Terapia Ultravioleta/métodos , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/radioterapia , Neoplasias Cutáneas/diagnóstico , Psoriasis/diagnóstico , Psoriasis/radioterapia , Psoriasis/terapia , Anciano , Crioterapia/efectos adversos
4.
Carcinogenesis ; 44(10-11): 773-784, 2023 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-37681453

RESUMEN

OBJECTIVES: The CHRNΑ5 gene, which encodes the α5-nicotinic acetylcholine receptor (α5-nAChR), is related to lung cancer and nicotine addiction. Smoking is closely related to the immunosuppressive effect of macrophages. CD47, a phagocytosis checkpoint in macrophages, is a therapeutic target in various cancer types. Nevertheless, the relationship between α5-nAChR and CD47 in lung cancer is still unclear. METHODS AND RESULTS: The present study showed that α5-nAChR-mediated CD47 expression via STAT3 signaling, consequently leading to tumor progression and immune suppression in lung adenocarcinoma (LUAD). α5-nAChR expression was correlated with STAT3 expression, CD47 expression, smoking status and poor prognosis of LUAD in vivo. In vitro, α5-nAChR expression mediated the phosphorylation of STAT3, and phosphorylated STAT3 bound to the CD47 promoter and mediated CD47 expression. Downregulation of α5-nAChR and/or CD47 significantly reduced cell proliferation, migration, invasion, stemness and IL-10 expression, but increased TNF-α expression and phagocytosis of macrophages in LUAD. Furthermore, α5-nAChR/CD47 signaling contributed to the growth of subcutaneous xenograft tumors and liver metastasis of tumors in mice. CONCLUSION: The α5-nAChR/STAT3/CD47 axis contributed to the progression and immune escape of lung cancer and may be a potential target for LUAD immunotherapy.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Receptores Nicotínicos , Humanos , Animales , Ratones , Nicotina/farmacología , Antígeno CD47/genética , Antígeno CD47/metabolismo , Receptores Nicotínicos/metabolismo , Neoplasias Pulmonares/patología , Adenocarcinoma del Pulmón/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo
5.
Lasers Med Sci ; 38(1): 195, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37639055

RESUMEN

Fractional carbon dioxide (CO2) laser combined with subcision has been widely used for the clinical treatment, but the efficacy of the combined therapy on three types of atrophic acne scars remains unreported. This retrospective study analyzed the clinical data of 413 patients with atrophic acne scars, treated with fractional CO2 laser combined with subcision in the combined group and with fractional CO2 laser in the control group. The treatment efficacy was evaluated by the Investigator's Global Assessment (IGA) and the Échelle d'évaluation clinique des cicatrices d'acné (ECCA). We reported adverse reactions such as erythema, lump, skin sensitivity, acne recurrence, and hyperpigmentation that occurred in both treatment groups. The treatment efficiency of the combined group was significantly higher than that of the control group (P < 0.001). Among the three subtypes of atrophic acne scars, the ECCA scores in the combined group of boxcar-type and rolling-type scars after treatment were lower than those in the control group (P = 0.041, P < 0.001, respectively), and no statistical difference in scores between the two groups for icepick-type scars was seen (P = 0.062). There was no statistical difference in adverse reactions between the two groups (P = 0.361). Fractional CO2 laser combined with subcision is more effective than fractional CO2 laser in the treatment of boxcar-type and rolling-type scars, but there is no significant difference in the treatment of icepick-type scars.


Asunto(s)
Acné Vulgar , Láseres de Gas , Humanos , Cicatriz/etiología , Cicatriz/radioterapia , Cicatriz/cirugía , Dióxido de Carbono , Estudios Retrospectivos , Láseres de Gas/efectos adversos , Acné Vulgar/complicaciones , Atrofia
6.
Cell Mol Life Sci ; 80(5): 119, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37029227

RESUMEN

Chronic stress significantly elevates the expression levels of various neurotransmitters in the tumour microenvironment, thereby promoting the cell growth and metastasis of lung adenocarcinoma (LUAD). However, the role of chronic stress in the progression of LUAD remains unclear. In this study, we found that chronic restraint stress increases the levels of the neurotransmitter acetylcholine (ACh), and the α5-nicotinic acetylcholine receptor (α5-nAChR) and decreased fragile histidine triad (FHIT) expression in vivo. Crucially, the increased ACh levels promoted LUAD cell migration and invasion via modulation of the α5-nAChR/DNA methyltransferase 1 (DNMT1)/FHIT axis. In a chronic unpredictable stress (CUMS) mouse model, chronic stress promotes tumour development, accompanied by changes in α5-nAChR, DNMT1, FHIT, and vimentin. Together, these findings reveal a novel chronic stress-mediated LUAD signalling pathway: chronic stress enforces lung adenocarcinoma cell invasion and migration via the ACh/α5-nAChR/FHIT axis, which could be a potential therapeutic target for chronic stress-related LUAD.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Receptores Nicotínicos , Animales , Ratones , Nicotina/farmacología , Acetilcolina/farmacología , Receptores Nicotínicos/genética , Transducción de Señal , Neoplasias Pulmonares/patología , Línea Celular Tumoral , Microambiente Tumoral
7.
Food Chem ; 420: 136002, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37060671

RESUMEN

The high ß-glucan content in barley disrupts the gluten network in dough. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), and solid-state nuclear magnetic resonance (NMR) techniques were used to clarify how ß-glucan affected the quality of the gluten network structure with ß-glucan contents of 0-2%. The results suggest that the physical hindrance of the ß-glucan gel destroyed the formation of the gluten network structure. When 1.0-2.0% ß-glucan was added, the percentage of α-helical structures increased significantly. When the added amount of ß-glucan reached 2.0%, the sulfhydryl group (SH) content increased from 8.06 to 10.27 µmol/g, and the disulfide bond (SS) content decreased from 240.09 to 217.38 µmol/g. The interaction between ß-glucan and gluten mainly resulted from the interaction of electron-withdrawing groups, such as carbonyl groups (CO) and double bond carbons (CC), and carbon atoms on the side chains of ß-glucan, which play an important role in the central structure of glutenin.


Asunto(s)
Hordeum , beta-Glucanos , beta-Glucanos/química , Hordeum/química , Rastreo Diferencial de Calorimetría/métodos
8.
EMBO Rep ; 24(4): e56645, 2023 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-36852962

RESUMEN

The chitin-based peritrophic matrix (PM) is a structure critical for both gut immunity and digestion in invertebrates. PM was traditionally considered lost in all vertebrates, but a PM-like chitinous membrane (CM) has recently been discovered in fishes, which may increase the knowledge on vertebrate gut physiology and structural evolution. Here, we show that in zebrafish, the CM affects ingestion behavior, microbial homeostasis, epithelial renewal, digestion, growth, and longevity. Young mutant fish without CM appear healthy and are able to complete their life cycle normally, but with increasing age they develop gut inflammation, resulting in gut atrophy. Unlike mammals, zebrafish have no visible gel-forming mucin layers to protect their gut epithelia, but at least in young fish, the CM is not a prerequisite for the antibacterial gut immunity. These findings provide new insights into the role of the CM in fish prosperity and its eventual loss in tetrapods. These findings may also help to improve fish health and conservation, as well as to advance the understanding of vertebrate gut physiology and human intestinal diseases.


Asunto(s)
Quitina , Pez Cebra , Animales , Humanos , Membranas , Inflamación , Estadios del Ciclo de Vida , Mamíferos
9.
Front Immunol ; 13: 971883, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36275759

RESUMEN

The Apextrin C-terminal (ApeC) domain is a new protein domain largely specific to aquatic invertebrates. In amphioxus, a short-form ApeC-containing protein (ACP) family is capable of binding peptidoglycan (PGN) and agglutinating bacteria via its ApeC domain. However, the functions of ApeC in other phyla remain unknown. Here we examined 130 ACPs from gastropods and bivalves, the first and second biggest mollusk classes. They were classified into nine groups based on their phylogenetics and architectures, including three groups of short-form ACPs, one group of apextrins and two groups of ACPs of complex architectures. No groups have orthologs in other phyla and only four groups have members in both gastropods and bivalves, suggesting that mollusk ACPs are highly diversified. We selected one bivalve ACP (CgACP1; from the oyster Crossostrea gigas) and one gastropod ACP (BgACP1; from the snail Biomphalaria glabrata) for functional experiments. Both are highly-expressed, secreted short-form ACPs and hence comparable to the amphioxus ACPs previously reported. We found that recombinant CgACP1 and BgACP1 bound with yeasts and several bacteria with different affinities. They also agglutinated these microbes, but showed no inhibiting or killing effects. Further analyses show that both ACPs had high affinities to the Lys-type PGN from S. aureus but weak or no affinities to the DAP-type PGN from Bacillus subtilis. Both recombinant ACPs displayed weak or no affinities to other microbial cell wall components, including lipopolysaccharide (LPS), lipoteichoic acid (LTA), zymosan A, chitin, chitosan and cellulose, as well as to several PGN moieties, including muramyl dipeptide (MDP), N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc). Besides, CgACP1 had the highest expression in the gill and could be greatly up-regulated quickly after bacterial challenge. This is reminiscent of the amphioxus ACP1/2 which serve as essential mucus lectins in the gill. Taken together, the current findings from mollusk and amphioxus ACPs suggest several basic common traits for the ApeC domains, including the high affinity to Lys-type PGN, the bacterial binding and agglutinating capacity, and the role as mucus proteins to protect the mucosal surface.


Asunto(s)
Quitosano , Anfioxos , Animales , Peptidoglicano/farmacología , Lipopolisacáridos , Acetilmuramil-Alanil-Isoglutamina/farmacología , Staphylococcus aureus/metabolismo , Acetilglucosamina/química , Zimosan , Anfioxos/metabolismo , Bacterias/metabolismo , Pared Celular/metabolismo , Lectinas , Moluscos , Celulosa
10.
J Invest Dermatol ; 142(11): 2978-2987.e6, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35513071

RESUMEN

It is well known that psoriasis is closely related to smoking, and CHRNA5 plays an important role in smoking-related diseases. However, studies on the relationship between CHRNA5 and psoriasis are limited. This study aimed to examine the role of CHRNA5 in psoriasis development and pathogenesis. Analysis in psoriatic tissues and imiquimod-induced mouse models showed that CHRNA5 was highly expressed in psoriatic lesional skin. To further verify the function of CHRNA5, we constructed Chrna5-knockout mice and induced the psoriasis model. We found that Chrna5 knockout significantly reduced the severity of psoriasis and could regulate inflammation through the MAPK kinase kinase-1/c-Jun N-terminal kinase‒MAPK/NF-κB pathway. The single-cell sequencing results revealed that after Chrna5 knockout, the keratinocyte subpopulation was significantly reduced and the related Jak/signal transducer and activator of transcription signaling pathway was downregulated, further indicating the importance of CHRNA5 in psoriasis. Human keratinocytes were analyzed, and silencing CHRNA5 inhibited keratinocyte proliferation and migration. In summary, CHRNA5 played important roles in the development and pathogenesis of psoriasis, and targeting CHRNA5 may be an effective strategy for the treatment of psoriasis.


Asunto(s)
Psoriasis , Receptores Nicotínicos , Ratones , Animales , Humanos , Imiquimod/farmacología , FN-kappa B/metabolismo , Psoriasis/metabolismo , Queratinocitos/metabolismo , Inflamación/metabolismo , Modelos Animales de Enfermedad , Ratones Noqueados , Proliferación Celular/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Ratones Endogámicos BALB C , Proteínas del Tejido Nervioso/metabolismo , Receptores Nicotínicos/metabolismo
11.
Hum Cell ; 35(4): 1207-1218, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35593989

RESUMEN

α5 nicotinic acetylcholine receptor (α5-nAChR) is associated with the progression of smoking-related lung adenocarcinoma (LUAD), but the molecular mechanism is unclear. Programmed death ligand 1 (PD-L1) is encoded by the CD274 gene, which not only inhibits the immune system, but also plays a unique role in tumor growth and metastasis. Here, we gained important insights into the underlying mechanism between α5-nAChR and PD-L1 in LUAD progression. α5-nAChR was overexpressed in various histological subtypes, cancer stages and metastasis statuses of LUAD. The group that coexpressed α5-nAChR and PD-L1 had a worse prognosis than the other subgroups at different stages of LUAD lymph node metastasis. The expression of α5-nAChR and PD-L1 was associated with epithelial-mesenchymal transition (EMT) marker CDH2. In vitro, α5-nAChR mediated nicotine-induced PD-L1 expression via STAT3 and the expression of EMT markers. Downregulation of α5-nAChR and/or PD-L1 inhibited EMT marker expression, cell proliferation, migration and invasion compared to silencing α5-nAChR or PD-L1 alone in LUAD cells. Furthermore, α5-nAChR expression was associated with PD-L1 and EMT marker expression in mouse xenograft models. These results highlight that α5-nAChR mediates STAT3/PD-L1 signaling, which contributes to cell migration and invasion. Therefore, our study may reveal a new interaction between α5-nAChR and PD-L1 that is involved in tumor cell growth and progression in LUAD, which may be a promising target for NSCLC diagnosis and immunotherapy.


Asunto(s)
Adenocarcinoma del Pulmón , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Adenocarcinoma del Pulmón/genética , Animales , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Línea Celular Tumoral , Movimiento Celular/genética , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/patología , Ratones
12.
Foods ; 11(7)2022 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-35407083

RESUMEN

In food processing, the temperature is usually reduced to limit bacterial reproduction and maintain food safety. However, Staphylococcus aureus can adapt to low temperatures by controlling gene expression and protein activity, although its survival strategies normally vary between different strains. The present study investigated the molecular mechanisms of S. aureus with different survival strategies in response to low temperatures (4 °C). The survival curve showed that strain BA-26 was inactivated by 6.0 logCFU/mL after 4 weeks of low-temperature treatment, while strain BB-11 only decreased by 1.8 logCFU/mL. Intracellular nucleic acid leakage, transmission electron microscopy, and confocal laser scanning microscopy analyses revealed better cell membrane integrity of strain BB-11 than that of strain BA-26 after low-temperature treatment. Regarding oxidative stress, the superoxide dismutase activity and the reduced glutathione content in BB-11 were higher than those in BA-26; thus, BB-11 contained less malondialdehyde than BA-26. RNA-seq showed a significantly upregulated expression of the fatty acid biosynthesis in membrane gene (fabG) in BB-11 compared with BA-26 because of the damaged cell membrane. Then, catalase (katA), reduced glutathione (grxC), and peroxidase (ahpC) were found to be significantly upregulated in BB-11, leading to an increase in the oxidative stress response, but BA-26-related genes were downregulated. NADH dehydrogenase (nadE) and α-glucosidase (malA) were upregulated in the cold-tolerant strain BB-11 but were downregulated in the cold-sensitive strain BA-26, suggesting that energy metabolism might play a role in S. aureus under low-temperature stress. Furthermore, defense mechanisms, such as those involving asp23, greA, and yafY, played a pivotal role in the response of BB-11 to stress. The study provided a new perspective for understanding the survival mechanism of S. aureus at low temperatures.

14.
Environ Sci Pollut Res Int ; 28(48): 69093-69110, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34283352

RESUMEN

Land space is the carrier of human production, living activities, and ecological civilization construction. How to promote the orderly, moderate, and sustainable development and utilization of land space is a scientific problem to be solved. As a key element in China's spatial planning, the quantitative analysis of spatial pattern and functional zoning has become a focus of China's current development. Based on the analysis of land space symbiosis development, this study takes Henan province as the case study; appropriate indicators were selected from the perspective of "production-living-ecological" functions (PLEFs) index that was developed including three subsystems of the production function, living function, and ecological function. The entropy weight method and geographic information system (GIS) spatial method were used to analyze the PLEF status and spatial pattern in Henan province. The PLEF score showed a certain geographical pattern, where in the southwestern areas of Henan province have higher PLEFs than that in the northeastern areas. The PLEFs have an obvious positive correlation in the spatial distribution by spatial correlation analysis. In addition, this study designs a three-dimensional magic cube evaluation model to analyze the symbiotic function type of land space. The results indicated that the PLEFs of Henan province were classified into 13 symbiotic function types of areas, which can better reflect the spatial differentiation characteristics. Moreover, we proposed paths to promote the development and management of each type function area.


Asunto(s)
Planificación de Ciudades , Conservación de los Recursos Naturales , Desarrollo Sostenible , China , Humanos , Análisis Espacial
15.
J Food Sci Technol ; 56(6): 2932-2939, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31205348

RESUMEN

The objective of this study was to investigate the effects and mechanism of potassium alum (PA) on potato starch noodles to provide a theoretical basis for future searches for new alternatives for PA that are not harmful to the body. The amount of amylose leakage significantly decreased with the PA addition. SEM showed that the honeycomb structure of potato starch noodles with 0.1% PA was diminished. The number of internal pores and average area decreased from 92 and 580.09 units to 72 and 652.58 units, respectively. NMR indicated that the water holding capacity of potato starch noodles containing PA was greater than that of the control. XRD showed that the crystal structure of potato starch noodles was destroyed and that the crystallinity of potato starch noodles with PA increased from 16.65 to 19.64%. G' and G'' increased, but tanδ decreased. FT-IR showed that PA caused the O-H stretching vibration in the absorption peak to move in the high-field direction and that the ionic bond was dominant in the PA-potato starch interaction system.

16.
Wei Sheng Wu Xue Bao ; 55(11): 1409-17, 2015 Nov 04.
Artículo en Chino | MEDLINE | ID: mdl-26915222

RESUMEN

OBJECTIVE: To study the repair mechanisms of frozen sublethally damaged Staphylococcus aurous cells. METHODS: We resuscitated frozen sublethally damaged S. aureus at 37 degrees C for different time within 3 h. Meanwhile, we compared the morphological changes of the frozen sublethally damaged cells after 1 h of resuscitation using transmission electron microscopy assay (TEM). The expressions of the transcriptional attenuator MsrR (msrR), iron (Fe3+) ABC transporter ATP-binding protein (fhuC), and cytochrome b (cytB) genes were quantitatively analyzed by real-time fluorescence quantitative PCR (Real-time PCR) method. The content of cells outside leakage, active oxygen (ROS), and superoxide dismutase (SOD) activity were also determined by ultraviolet spectrophotometry. RESULTS: More than 99% of the frozen sublethally damaged S. aureus repaired after 3 h. The resuscitated cells expressed an equal resistance to high concentration of NaCl. Real-time PCR results showed that the msrR and fhuC genes expressions were down-regulated, whereas the cytB gene expression was up-regulated significantly. The frozen sublethally damaged S. aureus cellar surface ultrastructure significant changed during resuscitation. The cell surface became compact and sturdy from smooth and transparent. The cell leakage rate of ultraviolet absorption material gradually decreased. Meanwhile, the intracellular ROS level declined along with the decrease of SOD activity. CONCLUSION: Frozen sublethally damaged cells may regain the capability of resistance to high salt stress by repairing cell membrane integrity, reducing the content of ROS through gene regulation, inhibiting the toxicity of active oxygen to the cells. Meanwhile, the regulation of metabolism related genes (cytB) provides the energy for the requirement of cells, therefore, the frozen sublethally damaged cells were repaired finally.


Asunto(s)
Staphylococcus aureus/química , Staphylococcus aureus/crecimiento & desarrollo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Membrana Celular/química , Membrana Celular/genética , Membrana Celular/metabolismo , Congelación , Regulación Bacteriana de la Expresión Génica , Viabilidad Microbiana , Especies Reactivas de Oxígeno/metabolismo , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo
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