RESUMEN
Two Gram-stain-negative, rod-shaped, non-motile, aerobic and carotenoid-producing strains, belonging to the family Erythrobacteraceae, designated as H149T and Z2T, were isolated from tidal flat sediment samples collected in Hainan and Zhejiang, PR China, respectively. Growth of strain H149T occurred at 15-42 °C, 0-10.0â% (w/v) NaCl, and pH 6.0-8.5, with the optima at 35-37 °C, 3.0-3.5â% (w/v) NaCl and pH 7.0. Strain Z2T grew at 15-37 °C, 0-6.0â% (w/v) NaCl, and pH 6.0-9.5, with the optima at 25-30 °C, 0.5-1.0â% (w/v) NaCl and pH 6.0-6.5. Ubiquinone-10 was the sole ubiquinone in two strains. The predominant cellular fatty acids of strain H149T were C16â:â0, summed feature 3 and summed feature 8, while those of strain Z2T were C17â:â1 ω6c, summed feature 3 and summed feature 8. Strains H149T and Z2T shared diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid as major polar lipids. The 16S rRNA gene sequence identity analysis indicated that strain H149T had the highest sequence identity of 98.4â% with Aurantiacibacter odishensis KCTC 23981T, and strain Z2T had that of 98.2â% with Qipengyuania pacifica NZ-96T. Phylogenetic trees based on 16S rRNA gene and core-genome sequences revealed that strains H149T and Z2T formed two independent clades in the genera Aurantiacibacter and Qipengyuania, respectively. Strain H149T had average nucleotide identity values of 74.0-81.3â% and in silico DNA-DNA hybridization values of 18.5-23.1â% with Aurantiacibacter type strains, while strain Z2T had values of 73.3-78.7â% and 14.5-33.3â% with Qipengyuania type strains. The genomic DNA G+C contents of strains H149T and Z2T were 64.3 and 61.8â%, respectively. Based on the genetic, genomic, phylogenetic, physiological and chemotaxonomic results, strains H149T (=KCTC 8397T=MCCC 1K08920T) and Z2T (=KCTC 8396T=MCCC 1K08946T) are concluded to represent two novel Erythrobacteraceae species for which the names Aurantiacibacter hainanensis sp. nov. and Qipengyuania zhejiangensis sp. nov. are proposed, respectively.
Asunto(s)
Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Sedimentos Geológicos , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Ubiquinona , ARN Ribosómico 16S/genética , Sedimentos Geológicos/microbiología , China , ADN Bacteriano/genética , Agua de Mar/microbiología , FosfolípidosRESUMEN
In accordance with "the response to injury" theory, the entry of monocytes into the intima guided by inflammation signals, taking up cholesterol and transforming into foam cells, and egress from plaques determines the progression of atherosclerosis. Multiple cytokines and receptors have been reported to be involved in monocyte recruitment such as CCL2/CCR2, CCL5/CCR5, and CX3CL1/CX3CR1, and the egress of macrophages from the plaque like CCR7/CCL19/CCL21. Interestingly, some neural guidance molecules such as Netrin-1 and Semaphorin 3E have been demonstrated to show an inhibitory effect on monocyte migration. During the processes of monocytes recruitment and migration, factors affecting the biomechanical properties (e.g., the membrane fluidity, the deformability, and stiffness) of the monocytes, like cholesterol, amyloid-ß peptide (Aß), and lipopolysaccharides (LPS), as well as the biomechanical environment that the monocytes are exposed, like the extracellular matrix stiffness, mechanical stretch, blood flow, and hypertension, were discussed in the latter section. Till now, several small interfering RNAs (siRNAs), monoclonal antibodies, and antagonists for CCR2 have been designed and shown promising efficiency on atherosclerosis therapy. Seeking more possible biochemical factors that are chemotactic or can affect the biomechanical properties of monocytes, and uncovering the underlying mechanism, will be helpful in future studies.
Asunto(s)
Aterosclerosis , Monocitos , Aterosclerosis/tratamiento farmacológico , Humanos , Lipopolisacáridos , Macrófagos , Receptores CCR2RESUMEN
Brain metastases are the most prevalent cerebral tumors. Resting state networks (RSNs) are involved in multiple perceptual and cognitive functions. Therefore, precisely localizing multiple RSNs may be extremely valuable before surgical resection of metastases, to minimize neurocognitive impairments. Here we aimed to investigate the reliability of independent component analysis (ICA) for localizing multiple RSNs from resting-state functional MRI (rs-fMRI) data in individual patients, and further evaluate lesion-related spatial shifts of the RSNs. Twelve patients with brain metastases and 14 healthy controls were recruited. Using an improved automatic component identification method, we successfully identified seven common RSNs, including: the default mode network (DMN), executive control network (ECN), dorsal attention network (DAN), language network (LN), sensorimotor network (SMN), auditory network (AN) and visual network (VN), in both individual patients and controls. Moreover, the RSNs in the patients showed a visible spatial shift compared to those in the controls, and the spatial shift of some regions was related to the tumor location, which may reflect a complicated functional mechanism - functional disruptions and reorganizations - caused by metastases. Besides, higher cognitive networks (DMN, ECN, DAN and LN) showed significantly larger spatial shifts than perceptual networks (SMN, AN and VN), supporting a functional dichotomy between the two network groups even in pathologic alterations associated with metastases. Overall, our findings provide evidence that ICA is a promising approach for presurgical localization of multiple RSNs from rs-fMRI data in individual patients. More attention should be paid to the spatial shifts of the RSNs before surgical resection.
Asunto(s)
Mapeo Encefálico/métodos , Neoplasias Encefálicas/fisiopatología , Encéfalo/fisiopatología , Imagen por Resonancia Magnética/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
Neuronal growth, differentiation, extension, branching and neural network activity are strongly influenced by the mechanical property of extracellular matrix (ECM). However, the mechanism by which substrate stiffness regulates a neural network activity, and the importance of ECM composition in conferring substrate stiffness sensing have not been explored. To address this question, the hippocampal neurons were seeded on the polydimethylsiloxane (PDMS) substrate with different stiffness, which were coated with fibronectin and laminin respectively. Our results show that voltage-gated Ca2+ channel currents are greater in neurons on the stiff substrate than on the soft substrate. In addition, the neurons exhibit a greater increase of Ca2+ currents on laminin-coated stiff substrate than on those coated with fibronectin, indicating that the composition of ECM can modulate responses to substrate stiffness of neurons. Paired patch-clamp recordings have shown that upregulation of neural effective synaptic connectivity is greater on the laminin-coated stiff substrate than on the fibronectin-coated ones. Consistently, laminin-coated stiff substrate enhances Ca2+ oscillations of neurons is greater that compared with the fibronectin-coated ones. Our study demonstrates that a direct role for substrate stiffness in regulating neuronal network activity and indicate that this modulation is dependent on a specific type of ECM protein, which should be taken into account for the design of biomaterials for neuronal tissue engineering.
Asunto(s)
Dimetilpolisiloxanos/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Redes Neurales de la Computación , Animales , Calcio/metabolismo , Dimetilpolisiloxanos/química , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Ratones , Ingeniería de TejidosRESUMEN
It is well recognized that pathologically increased mechanical stretch plays a critical role in vascular remodeling during hypertension. However, how the stretch modulates the functions of ion channels of vascular smooth muscle cells (VSMCs) remains to be elucidated. Here, we demonstrated the effects of mechanical stretch on the activity of large conductance calcium, voltage-activated potassium (BK) and L-type Ca2+ channels. In comparison with 5% stretch (physiological), 15% stretch (pathological) upregulated the current density of L-type Ca2+ and BK channels as well as the frequency and amplitude of calcium oscillation in VSMCs. 15% stretch also increased the open probability and mean open time of the BK channel compared with 5% stretch. BK and L-type Ca2+ channels participated in the mechanical stretch-modulated calcium oscillation. Our results suggested that during hypertension, pathological stretch altered the activity of BK and L-type Ca2+ channels and manipulated the calcium oscillation of VSMCs.
Asunto(s)
Canales de Potasio de Gran Conductancia Activados por el Calcio/fisiología , Músculo Liso Vascular/fisiología , Miocitos del Músculo Liso/fisiología , Canales de Potasio con Entrada de Voltaje/fisiología , Estrés Mecánico , Animales , Fenómenos Electrofisiológicos , Oscilometría , Técnicas de Placa-Clamp , Ratas , Ratas Sprague-DawleyRESUMEN
White matter lesions (WMLs) have been associated with cognitive and motor decline. Resting state networks (RSNs) are spatially coherent patterns in the human brain and their interactions sustain our daily function. Therefore, investigating the altered intra- and inter-network connectivity among the RSNs may help to understand the association of WMLs with impaired cognitive and motor function. Here, we assessed alterations in functional connectivity patterns based on six well-defined RSNs-the default mode network (DMN), dorsal attention network (DAN), frontal-parietal control network (FPCN), auditory network (AN), sensory motor network (SMN) and visual network (VN)-in 15 patients with ischemic WMLs and 15 controls. In the patients, Spearman's correlation analysis was further performed between these alterations and cognitive test scores, including Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. Our results showed wide alterations of inter-network connectivity mainly involving the SMN, DMN, FPCN and DAN, and some alterations correlated with cognitive test scores in the patients. The reduced functional connectivities in the SMN-AN, SMN-VN, FPCN-AN, DAN-VN pairs may account for the cognitive and motor decline in patients with ischemic WMLs, while the increased functional connectivities in the DMN-AN, DMN-FPCN and DAN-FPCN pairs may reflect a functional network reorganization after damage to white matter. It is unexpected that altered intra-network connectivities were found within the AN and VN, which may explain the impairments in verbal fluency and information retrieval associated with WMLs. This study highlights the importance of functional connectivity in understanding how WMLs influence cognitive and behavior dysfunction.