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1.
mSystems ; : e0043421, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34491082

RESUMO

Enterococcus faecalis, an opportunistic pathogen that causes severe community-acquired and nosocomial infections, has been reported to resist phagocyte-mediated killing, which enables its long-term survival in the host. Metabolism, especially carbohydrate metabolism, plays a key role in the battle between pathogens and hosts. However, the function of carbohydrate metabolism in the long-term survival of E. faecalis in phagocytes has rarely been reported. In this study, we utilized transposon insertion sequencing (TIS) to investigate the function of carbohydrate metabolism during the survival of E. faecalis in RAW264.7 cells. The TIS results showed that the fitness of carbohydrate metabolism-related mutants, especially those associated with fructose and mannose metabolism, were significantly enhanced, suggesting that the attenuation of carbohydrate metabolism promotes the survival of E. faecalis in macrophages. The results of our investigation indicated that macrophages responded to carbohydrate metabolism of E. faecalis and polarized to M1 macrophages to increase nitric oxide (NO) production, leading to the enhancement of macrophage-mediated killing to E. faecalis. Meanwhile, E. faecalis automatically decreased carbohydrate metabolism to escape from the immune clearance of macrophages during intracellular survival. The shift of primary carbon resources for macrophages affected the ability to clear intracellular E. faecalis. In summary, the results of the present study demonstrated that carbohydrate metabolism affects the macrophage-mediated killing of E. faecalis. IMPORTANCE E. faecalis has become a major pathogen leading to a variety of infections around the world. The metabolic interaction between E. faecalis and its host is important during infection but is rarely investigated. We used transposon insertion sequencing coupled with transcriptome sequencing to explore the metabolic interaction between E. faecalis and macrophages and uncovered that the shift of carbohydrate metabolism dramatically affected the inflammatory response of macrophages. In addition, E. faecalis attenuated carbohydrate metabolism to avoid the activation of the immune response of macrophages. This study provides new insights for the reason why E. faecalis is capable of long-term survival in macrophages and may facilitate the development of novel strategies to treat infectious diseases.

2.
J Colloid Interface Sci ; 607(Pt 1): 53-60, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34492353

RESUMO

Mixed electronic and ionic conductivity (MIEC) perovskite oxides hold promise as cathode with high oxygen reduction reaction (ORR) activity for solid oxide fuel cells (SOFCs) operating at reduced temperatures. However, these MIEC cathodes usually contain lanthanide or alkaline-earth elements at A-site. These elements tend to interact with yttria-stabilized zirconia electrolyte (YSZ) to form unwanted phases such as La2Zr2O7 and SrZrO3 at conventional electrode fabrication conditions (>800 °C). Such unwanted interfacial reaction severely degrades the cell performance. We present a new method to assemble SrCo0.4Fe0.5W0.1O3-δ (SCFW) directly onto YSZ by a highly efficient microwave plasma technique. Intimate contact between SCFW and YSZ phases can be achieved by ten-minute microwave-plasma treatment with no new phase formation. Consequently, the microwave-plasma fabricated interface exhibits a notably high ORR performance, showing an area-specific resistances of 0.11 Ω cm2 at 600 °C, about two orders of magnitude better than the equivalent prepared via the conventional method. Our method is also effective in assembling other MIEC perovskite cathodes such as SrCo0.5Fe0.5O3-δ and SrCo0.8Nb0.1Ta0.1O3-δ on YSZ electrolyte, achieving notable enhancement of the cathode performance. This study thus provides an effective and convenient method for synthesizing reactive and robust interfaces between two incompatible phases with minimized interphase interactions.

4.
Front Endocrinol (Lausanne) ; 12: 709711, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539568

RESUMO

Genetic disorders of the skeleton encompass a diverse group of bone diseases differing in clinical characteristics, severity, incidence and molecular etiology. Of particular interest are the monogenic rare bone mass disorders, with the underlying genetic defect contributing to either low or high bone mass phenotype. Extensive, deep phenotyping coupled with high-throughput, cost-effective genotyping is crucial in the characterization and diagnosis of affected individuals. Massive parallel sequencing efforts have been instrumental in the discovery of novel causal genes that merit functional validation using in vitro and ex vivo cell-based techniques, and in vivo models, mainly mice and zebrafish. These translational models also serve as an excellent platform for therapeutic discovery, bridging the gap between basic science research and the clinic. Altogether, genetic studies of monogenic rare bone mass disorders have broadened our knowledge on molecular signaling pathways coordinating bone development and metabolism, disease inheritance patterns, development of new and improved bone biomarkers, and identification of novel drug targets. In this comprehensive review we describe approaches to further enhance the innovative processes taking discoveries from clinic to bench, and then back to clinic in rare bone mass disorders. We highlight the importance of cross laboratory collaboration to perform functional validation in multiple model systems after identification of a novel disease gene. We describe the monogenic forms of rare low and high rare bone mass disorders known to date, provide a roadmap to unravel the genetic determinants of monogenic rare bone mass disorders using proper phenotyping and genotyping methods, and describe different genetic validation approaches paving the way for future treatments.

5.
Nat Commun ; 12(1): 5321, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493732

RESUMO

CARM1 is often overexpressed in human cancers including in ovarian cancer. However, therapeutic approaches based on CARM1 expression remain to be an unmet need. Cancer cells exploit adaptive responses such as the endoplasmic reticulum (ER) stress response for their survival through activating pathways such as the IRE1α/XBP1s pathway. Here, we report that CARM1-expressing ovarian cancer cells are selectively sensitive to inhibition of the IRE1α/XBP1s pathway. CARM1 regulates XBP1s target gene expression and directly interacts with XBP1s during ER stress response. Inhibition of the IRE1α/XBP1s pathway was effective against ovarian cancer in a CARM1-dependent manner both in vitro and in vivo in orthotopic and patient-derived xenograft models. In addition, IRE1α inhibitor B-I09 synergizes with immune checkpoint blockade anti-PD1 antibody in an immunocompetent CARM1-expressing ovarian cancer model. Our data show that pharmacological inhibition of the IRE1α/XBP1s pathway alone or in combination with immune checkpoint blockade represents a therapeutic strategy for CARM1-expressing cancers.

6.
Aging (Albany NY) ; 13(17): 21268-21282, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34497154

RESUMO

Temozolomide (TMZ) is used for the treatment of high-grade gliomas. Acquired chemoresistance is a serious limitation to the therapy with more than 90% of recurrent gliomas showing little response to a second line of chemotherapy. Therefore, it is necessary to explore an alternative strategy to enhance the sensitivity of glioblastoma (GBM) to TMZ in neuro-oncology. Celecoxib is well known and widely used in anti-inflammatory and analgesic. Cyclooxygenase-2 (COX-2) expression has been linked to the prognosis, angiogenesis, and radiation sensitivity of many malignancies such as primitive neuroectodermal tumor and advanced melanoma. The objective of this study was to explore the chemotherapy-sensitizing effect of celecoxib on TMZ in GBM cells and its potential mechanisms. From the study, we found that the combination therapy (TMZ 250uM+celecoxib 30uM) showed excellent inhibitory effect to the GBM, the LN229 and LN18, which were the TMZ resistant GBM cell lines. Our data suggest that the combination therapy may inhibits cell proliferation, increases apoptosis, and increases the autophagy on LN229 and LN18. The potential molecular mechanisms were related to mitochondrial metabolism and respiratory chain inhibition.

7.
Nat Genet ; 53(9): 1276-1282, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34493870

RESUMO

Late-onset Alzheimer's disease is a prevalent age-related polygenic disease that accounts for 50-70% of dementia cases. Currently, only a fraction of the genetic variants underlying Alzheimer's disease have been identified. Here we show that increased sample sizes allowed identification of seven previously unidentified genetic loci contributing to Alzheimer's disease. This study highlights microglia, immune cells and protein catabolism as relevant to late-onset Alzheimer's disease, while identifying and prioritizing previously unidentified genes of potential interest. We anticipate that these results can be included in larger meta-analyses of Alzheimer's disease to identify further genetic variants that contribute to Alzheimer's pathology.

8.
Environ Pollut ; 290: 117999, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34500397

RESUMO

Microplastics and nanoplastics are distributed in the environments universally. The interrelationship between vascular plants and micro/nanoplastics began to attract attention in recent years. Based on the relevant literatures collected from various databases, this review focuses on two topics: 1) the effect of vascular plants on the fate of micro/nanoplastics; 2) the effects of micro/nanoplastics on vascular plants. The review of the available studies reveals that vascular plants can act as sinks for microplastics and nanoplastics as their surfaces can adsorb these plastics; moreover, nanoplastics can be internalized by plants. Plastics on the surfaces and in the interiors of vascular plants can cause various phytotoxicity effects, including impacts on growth, photosynthesis, and oxidative stress. Furthermore, the results and mechanisms of phytotoxicity effects caused by microplastics or nanoplastics can be very different. However, knowledge gaps still exist in the relationships between micro/nanoplastics and vascular plants based on the analysis of available studies; thus, potential subjects for future studies were proposed, including the fates, analysis methods, influencing factors, mechanisms of phytotoxicity, and further influences of microplastics and nanoplastics in the vascular plant ecosystems. This study presents a review of micro/nanoplastics-vascular plant research and reaches a basis for future research.

9.
Psychol Health Med ; : 1-16, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465255

RESUMO

The aim of this meta-analysis was to compare health-related quality of life (HRQoL) of Osteoarthritis (OA) patients and controls. A systematic literature search was performed on PubMed, Web of Science and EMBASE from database inception to 7 January 2020. Random effect model was performed to summarize the scores of each domain and the forest plot was used to compare the scores of OA patients with healthy controls. Subgroup analyses were conducted to explore the source of heterogeneity. Statistical analyses were executed using Review Manager (version 5.1). In total, six studies were included in this study, including 7094 patients with OA and 12 100 healthy controls, which were all reliable to summarize the scores of the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). Meta-analyses found that pooled mean HRQoL score for the SF-36 each domain (physical function, physical role function, body pain, general health, vitality, social function, emotional role function, mental health) was lower in patients with OA than in healthy controls, especially the score in the dimension of physical role function. OA have a substantial impact HRQoL. HRQoL is a significant component of measuring overall health, which contributes to formulate successful self-disease management plan, patient-centered care, and develop effective interventions target confidence.

10.
Lancet Digit Health ; 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34538736

RESUMO

BACKGROUND: Inadequate bowel preparation is associated with a decrease in adenoma detection rate (ADR). A deep learning-based bowel preparation assessment system based on the Boston bowel preparation scale (BBPS) has been previously established to calculate the automatic BBPS (e-BBPS) score (ranging 0-20). The aims of this study were to investigate whether there was a statistically inverse relationship between the e-BBPS score and the ADR, and to determine the threshold of e-BBPS score for adequate bowel preparation in colonoscopy screening. METHODS: In this prospective, observational study, we trained and internally validated the e-BBPS system using retrospective colonoscopy images and videos from the Endoscopy Center of Wuhan University, annotated by endoscopists. We externally validated the system using colonoscopy images and videos from the First People's Hospital of Yichang and the Third Hospital of Wuhan. To prospectively validate the system, we recruited consecutive patients at Renmin Hospital of Wuhan University aged between 18 and 75 years undergoing colonoscopy. The exclusion criteria included: contraindication to colonoscopy, family polyposis syndrome, inflammatory bowel disease, history of surgery for colorectal or colorectal cancer, known or suspected bowel obstruction or perforation, patients who were pregnant or lactating, inability to receive caecal intubation, and lumen obstruction. We did colonoscopy procedures and collected withdrawal videos, which were reviewed and the e-BBPS system was applied to all colon segments. The primary outcome of this study was ADR, defined as the proportion of patients with one or more conventional adenomas detected during colonoscopy. We calculated the ADR of each e-BBPS score and did a correlation analysis using Spearman analysis. FINDINGS: From May 11 to Aug 10, 2020, 616 patients underwent screening colonoscopies, which evaluated. There was a significant inverse correlation between the e-BBPS score and ADR (Spearman's rank -0·976, p<0·010). The ADR for the e-BBPS scores 1-8 was 28·57%, 28·68%, 26·79%, 19·19%, 17·57%, 17·07%, 14·81%, and 0%, respectively. According to the 25% ADR standard for screening colonoscopy, an e-BBPS score of 3 was set as a threshold to guarantee an ADR of more than 25%, and so high-quality endoscopy. Patients with scores of more than 3 had a significantly lower ADR than those with a score of 3 or less (ADR 15·93% vs 28·03%, p<0·001, 95% CI 0·28-0·66, odds ratio 0·43). INTERPRETATION: The e-BBPS system has potential to provide a more objective and refined threshold for the quantification of adequate bowel preparation. FUNDING: Project of Hubei Provincial Clinical Research Center for Digestive Disease Minimally Invasive Incision and Hubei Province Major Science and Technology Innovation Project.

11.
Artigo em Inglês | MEDLINE | ID: mdl-34499385

RESUMO

Self-assembly of N,N,N ' ,N '-tetrakis(4-carboxyphenyl)-1,4-phenylenediamine with the help of different solvents provides isostructural hydrogen-bonded organic frameworks (HOF-30). Single crystal X-ray diffraction (SCXRD) analysis reveals HOF-30 possesses 3D ten-fold interpenetrated dia nets connected by two kinds of hydrogen bonds, namely solvent-bridged carboxyl dimers and carboxyl···carboxyl dimers. Degassing treatment for HOF-30 yields HOF-30a still with 3D ten-fold interpenetrated dia nets but linked with sole carboxyl···carboxyl dimers. Reversible hydrogen-bond-to-hydrogen-bond transformation between solvent-bridged·carboxyl dimers in HOF-30 and carboxyl···carboxyl dimers in HOF-30a has been unveiled by single crystal and powder X-ray diffraction. In addition, HOF-30a enables the selective adsorption of propyne over propylene according to the single component sorption and breakthrough experiments. The preferred propyne location in HOF has also been identified by SCXRD test.

12.
Environ Pollut ; 290: 118091, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34488157

RESUMO

Decision-making related to nitrogen (N) fertilization is a crucial step in agronomic practices because of its direct interactions with agronomic productivity and environmental risk. Here, we hypothesized that soil apparent N balance could be used as an indicator to determine the thresholds of N input through analyzing the responses of the yield and N loss to N balance. Based on the observations from 951 field experiments conducted in rice (Oryza sativa L.) cropping systems of China, we established the relationships between N balance and ammonia (NH3) volatilization, yield increase ratio, and N application rate, respectively. Dramatical increase of NH3 volatilizations and stagnant increase of the rice yields were observed when the N surplus exceeded certain levels. Using a piecewise regression method, the seasonal upper limits of N surplus were determined as 44.3 and 90.9 kg N ha-1 under straw-return and straw-removal scenarios, respectively, derived from the responses of NH3 volatilization, and were determined as 53.0-74.9 and 97.9-112.0 kg N ha-1 under straw-return and straw-removal scenarios, respectively, derived from the maximum-yield consideration. Based on the upper limits of N surplus, the thresholds of N application rate suggested to be applied in single, middle-MLYR, middle-SW, early, and late rice types ranged 179.0-214.9 kg N ha-1 in order to restrict the NH3 volatilization, and ranged 193.3-249.8 kg N ha-1 in order to achieve the maximum yields. If rice straw was returned to fields, on average, the thresholds of N application rate could be theoretically decreased by 17.5 kg N ha-1. This study provides a robust reference for restricting the N surplus and the synthetic fertilizer N input in rice fields, which will guide yield goals and environmental protection.

13.
Chem Commun (Camb) ; 57(74): 9316-9329, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34528952

RESUMO

Although transition metal carbenes have found widespread applications and difluorocarbene has served as a versatile intermediate, it is still quite challenging to make use of transition-metal difluorocarbenes in synthetic chemistry due to their unpredictable reactivities. In this Highlight, we review recent developments in the transition-metal-catalyzed or -mediated transfer of difluorocarbene and the reactivies and conversions of transition-metal difluorocarbene complexes. We start with the MCF2 bonding, then provide the progress in the transfer of difluorocarbene, and finally briefly discuss the conversions of MCF2 into other metal complexes. The understanding of the interesting reactivities of MCF2 may help design the catalytic transfer of difluorocarbene for various reactions.

14.
Physiol Int ; 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34529586

RESUMO

Objective: To evaluate in-vivo and in-vitro effects of ferulic acid (FA) on glucocorticoid-induced osteoarthritis (GIO) to establish its possible underlying mechanisms. Methods: The effects of FA on cell proliferation, cell viability (MTT assay), ALP activity, and mineralization assay, and oxidative stress markers (ROS, SOD, GSH LDH and MDA levels) were investigated by MC3T3-E1 cell line. Wistar rats received standard saline (control group) or dexamethasone (GC, 2 mg-1 kg) or DEX+FA (50 and 100 mg-1 kg) orally for 8 weeks. Bone density, micro-architecture, bio-mechanics, bone turnover markers and histo-morphology were determined. The expression of OPG, RANKL, osteogenic markers, and other signalling proteins was assessed employing quantitative RT-PCR and Western blotting. Results: The findings indicated the elevation of ALP mRNA expressions, osteogenic markers (Runx-2, OSX, Col-I, and OSN), and the ß-Catenin, Lrp-5 and GSK-3ß protein expressions. FA showed the potential to increase MC3T3-E1 cell differentiation, proliferation, and mineralization. FA increased oxidative stress markers (SOD, MDA, and GSH) while decreasing ROS levels and lactate dehydrogenase release in GIO rats. The OPG/RANKL mRNA expression ratio was increased by FA, followed by improved GSK-3ß and ERK phosphorylation with enhanced mRNA expressions of Lrp-5 and ß-catenin. Conclusion: These findings showed that FA improved osteoblasts proliferation with oxidative stress suppression by controlling the Lrp-5/GSK-3ß/ERK pathway in GIO, demonstrating the potential pathways involved in the mechanism of actions of FA in GIO therapy.

15.
Artigo em Inglês | MEDLINE | ID: mdl-34518084

RESUMO

BACKGROUND AND AIMS: The relationship between the body fat percentage (BFP) and hyperuricemia is still unknown in different gender subjects. The purpose of this study was to determine the magnitude of the association between the BFP and the presence of hyperuricemia in the sex-specific group among hypertensive patients. METHODS AND RESULTS: We conducted a cross-sectional study enrolling 14,234 hypertensive participates from the Chinese Hypertension Registry Study. Body fat percentage (BFP) was calculated by simple anthropometric parameters. Hyperuricemia was defined as serum uric acid (SUA) level 420 umol/L in men and 360 umol/L in women. The mean BFP was 24.5% in men and 37.1% in women. Multiple logistic analyses showed that the relationship between BFP with the risk of hyperuricemia in a dose-dependent manner among both men (odds ratio [OR] 1.07, 95% CI 1.06, 1.09) and women (OR 1.08, 95% CI 1.06, 1.09) in the fully adjusted model. Subgroup analyses showed the positive association between BFP and the risk of hyperuricemia was consistent in all stratification subgroups (all P for interaction >0.05). CONCLUSION: For patients with hypertension, BFP was positively associated with an increased risk of hyperuricemia among both men and women.

16.
J Nat Prod ; 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519213

RESUMO

The soil bacterium Streptomyces pactum ATCC 27456 produces a number of polyketide natural products. Among them is NFAT-133, an inhibitor of the nuclear factor of activated T cells (NFAT) that suppresses interleukin-2 (IL-2) expression and T cell proliferation. Biosynthetic gene inactivation in the ATCC 27456 strain revealed the ability of this strain to produce other polyketide compounds including analogues of NFAT-133. Consequently, seven new derivatives of NFAT-133, TM-129-TM-135, together with a known compound, panowamycin A, were isolated from the culture broth of S. pactum ATCC 27456 ΔptmTDQ. Their chemical structures were elucidated on the basis of their HRESIMS, 1D and 2D NMR spectroscopy, and ECD calculation and spectral data. NFAT-133, TM-132, TM-135, and panowamycin A showed no antibacterial activity or cytotoxicity, but weakly reduced the production of LPS-induced nitric oxide in RAW264.7 cells in a dose-dependent manner. A revised chemical structure of panowamycin A and proposed modes of formation of the new NFAT-133 analogues are also presented.

17.
Artigo em Inglês | MEDLINE | ID: mdl-34519394

RESUMO

Although super-resolution imaging offers an opportunity to visualize cellular structures and organelles at the nanoscale level, cellular heterogeneity and unpredictability still pose a significant challenge in the dynamic imaging of live cells. It is thus vital to develop better performing and more photostable probes for long-term super-resolution imaging. Herein, we report a probe LD-FG for imaging lipid droplet (LD) dynamics using structured illumination microscopy (SIM). LD-FG allows wash-free imaging of LDs, owing to hydrogen-bond sensitive fluorogenicity. The replenishment of photobleached LD-FG by intact ones outside LDs further ensure the long-time stability of the fluorescence imaging. With this buffering fluorogenic probe, fast and unpredictable dynamic processes of LDs can be visualized. Two LD coalescence modes (as well as heterogeneity in different regions of the cells and even in between different cells) were discovered for the first time. Notably, the dynamic imaging also allowed us to propose a new model of LD maturation during adipocyte differentiation, i.e. , a fast LD coalescence followed by a slow ripening step. The excellent performance of LD-FG makes the buffer strategy an effective method for designing fluorescent probes for cell dynamic imaging.

18.
Electrophoresis ; 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499755

RESUMO

Enhancing the specific surface area of stationary phase is important in chromatographic science, especially in open-tubular column in which the coating only exists on the inner surface. In this work, a porous layer open-tubular (PLOT) column with stationary phase of styrene and itaconic acid-copolymerized polymer was developed. Thermal-initiated polymerization method with strategies like controlling the ratio of reaction reagents to solvents and reaction time, confinement by the narrow inner diameter of capillary were used for preparing the stationary phase with uniform structure and relatively thick layer. Due to the high separation efficiency and capacity, the PLOT column was used for capillary electrochromatography (CEC) separation of multiple groups of analytes like alkylbenzenes, phenyl amines, phenols, vanillins, and sulfonamides with theoretical plates (N) up to 1,54,845 N/m. In addition, due to high permeability of the CEC column and large electroosmotic flow mobility generated by abundant carboxyl groups in the coating material, the PLOT-CEC column was successfully coupled with mass spectrometry (MS) through a sheath flow interface. The developed PLOT-CEC-MS method was used for the analysis of antiseptics like parabens and herbicides like pyridines.

19.
Front Cell Infect Microbiol ; 11: 706252, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34513728

RESUMO

The pandemic of COVID-19 by SARS-CoV-2 has become a global disaster. However, we still don't know how specific SARS-CoV-2-encoded proteins contribute to viral pathogenicity. We found that SARS-CoV-2-encoded membrane glycoprotein M could induce caspase-dependent apoptosis via interacting with PDK1 and inhibiting the activation of PDK1-PKB/Akt signaling. Our investigation further revealed that SARS-CoV-2-encoded nucleocapsid protein N could specifically enhance the M-induced apoptosis via interacting with both M and PDK1, therefore strengthening M-mediated attenuation of PDK1-PKB/Akt interaction. Furthermore, when the M-N interaction was disrupted via certain rationally designed peptides, the PDK1-PKB/Akt signaling was restored, and the boosting activity of N on the M-triggered apoptosis was abolished. Overall, our findings uncovered a novel mechanism by which SARS-CoV-2-encoded M triggers apoptosis with the assistance of N, which expands our understanding of the two key proteins of SARS-CoV-2 and sheds light on the pathogenicity of this life-threatening virus.


Assuntos
COVID-19 , SARS-CoV-2 , Apoptose , Humanos , Glicoproteínas de Membrana , Proteínas do Nucleocapsídeo , Glicoproteína da Espícula de Coronavírus
20.
J Biomech Eng ; 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34529040

RESUMO

Atherosclerotic plaques can gradually develop in certain arteries. Disruption of fibrous tissue in plaques can result in plaque rupture and thromboembolism, leading to heart attacks and strokes. Collagen fibrils are important tissue building blocks and tissue strength depends on how fibrils are oriented. Fibril orientation in plaque tissue may potentially influence vulnerability to disruption. While X-ray scattering has previously been used to characterize fibril orientations in soft tissues and bones, it has never been used for characterization of human atherosclerotic plaque tissue. This study served to explore fibril orientation in specimens from human plaques using small angle X-ray scattering. Plaque tissue was extracted from human femoral and carotid arteries, and each tissue specimen contained a region of calcified material. 3D collagen fibril orientation was determined along scan lines that started away from and then extended towards a given calcification. At locations several millimeters or more from a calcification, fibrils were found to be oriented predominantly in the circumferential direction of the plaque tissue. However, in a number of cases, the dominant fibril direction changed markedly near a calcification, from circumferential to longitudinal. Further study is needed to elucidate how these fibril patterns may change plaque tissue behavior.

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