Pulsed electromagnetic fields regulate osteocyte apoptosis,RANKL/OPG expression,and its control of osteoclastogenesis depending on the presence of primary cilia

Growing evidence has shown that pulsed electromagnetic fields (PEMF) can modulate bone metabolism in vivo and regulate the activities of osteoblasts and osteoclasts in vitro. Osteocytes, accounting for 95% of bone cells, act as the major mechanosensors in bone for transducing external mechanical signals and producing cytokines to regulate osteoblastic and osteoclastic activities. Targeting osteocytic signaling pathways is becoming an emerging therapeutic strategy for bone diseases. We herein systematically investigated the changes of osteocyte behaviors, functions, and its regulation on osteoclastogenesis in response to PEMF. The osteocyte-like MLO-Y4 cells were exposed to 15 Hz PEMF stimulation with different intensities (0, 5, and 30 Gauss [G]) for 2 hr. We found that the cell apoptosis and cytoskeleton organization of osteocytes were regulated by PEMF with an intensity-dependent manner. Moreover, PEMF exposure with 5 G significantly inhibited apoptosis-related gene expression and also suppressed the gene and protein expression of the receptor activator of nuclear factor κB ligand/osteoprotegerin (RANKL/OPG) ratio in MLO-Y4 cells. The formation, maturation, and osteoclastic bone-resorption capability of in vitro osteoclasts were significantly suppressed after treated with the conditioned medium from PEMF-exposed (5 G) osteocytes. Our results also revealed that the inhibition of osteoclastic formation, maturation, and bone-resorption capability induced by the conditioned medium from 5 G PEMF-exposed osteocytes was significantly attenuated after abrogating primary cilia in osteocytes using the polaris siRNA transfection. Together, our findings highlight that PEMF with 5 G can inhibit cellular apoptosis, modulate cytoskeletal distribution, and decrease RANKL/OPG expression in osteocytes, and also inhibit osteocyte-mediated osteoclastogenesis, which requires the existence of primary cilia in osteocytes. This study enriches our basic knowledge for further understanding the biological behaviors of osteocytes and is also helpful for providing a more comprehensive mechanistic understanding of the effect of electromagnetic stimulation on bone and relevant skeletal diseases (e.g., bone fracture and osteoporosis).     

MicroRNA miR-505-5p Promotes Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury via Negative Regulation of CREG1 in Cultured Neuron-Like Cells

Neurophysiology - Cerebral ischemia/reperfusion (I/R) injury is associated with various cardiovascular and cerebrovascular diseases with high disability, morbidity, and mortality rates. MicroRNAs...     

Quantitative phosphoproteomic analyses provide evidence for extensive phosphorylation of regulatory proteins in the rhizobia–legume symbiosis

Plant Molecular Biology - PsLecRLK overexpression in rice provides tolerance against salinity stress and cause upregulation of SOS1 pathway genes, which are responsible for extrusion of excess Na+...     

Regulation of PSII function in Cyanothece sp. ATCC 51142 during a light–dark cycle

Photosynthesis Research - Cyanobacteria, as well as green algae and higher plants, have highly conserved photosynthetic machinery. Cyanothece sp. ATCC 51142 is a unicellular, aerobic, diazotrophic...     

小菜蛾成虫下唇须感器的超微结构及其神经元中枢投射

【目的】明确小菜蛾Plutella xylostella成虫下唇须感器的形态结构及感器神经元的投射。【方法】利用光学显微镜观察和扫描电子显微镜观察下唇须结构和感器类型,利用神经回填技术和激光共聚焦显微镜观察下唇须感器神经元在脑部的投射。【结果】小菜蛾成虫下唇须共3节,其上存在Böhm氏鬃毛、钟形感器、鳞形感器、锥形感器、微毛形感器5种不同类型的感器和一个陷窝器结构。Böhm氏鬃毛短小尖细,钟形感器形如顶部凹陷的圆帽,两种感器均分布于下唇须第1节,且大小上均无雌雄二型差异;鳞形感器形同柳叶,锥形感器粗而直,均散生于下唇须的第2和3节,两种感器在大小上均存在雌雄二型差异,其中雌性的鳞形感器显著大于雄性的,根据其雌雄二型差异现象推测雌蛾的鳞形感器可能与感受寄主植物挥发物有关;下唇须第3节中上部具有一个圆形陷窝器结构,雄虫的陷窝器内径为5.68±0.33μm,雌虫的为6.03±0.23μm,雌雄间无显著性差异;凹坑内长有表面光滑的微毛形感器。小菜蛾下唇须感器神经元主要投射于脑部咽下神经节、每个触角叶的下唇须陷窝器神经纤维球和腹神经索3条通路。【结论】阐明了小菜蛾下唇须感器的类型、分布和形态特征及其感器神经元在脑部的投射形态,为深入了解小菜蛾下唇须感器的生理和功能奠定了基础。     

邓州八里岗仰韶时期居民的体质变迁

河南邓州八里岗遗址出土的仰韶早期与中晚期人骨体质状况的对比分析表明,八里岗仰韶文化在其延续千年的时间内,居民体质状况从早期到中晚期出现一系列变化。具体表现为女性身高的减少、男女性下肢功能活跃度的降低以及四肢长骨纤细化的倾向。古病理指征则展现出龋病发生的显著增加、头骨钝伤的减少以及女性胫骨骨膜反应增多等表现。这些体质状况的变迁,与八里岗仰韶文化发展过程中日趋定居的生活方式、农业经济渐趋成熟以及食物加工技术的进步有关。与此同时,女性的社会地位开始呈现下降的趋势。八里岗仰韶居民的体质特征改变与这一阶段仰韶社会的发展状况及古代人类的行为模式存在密切联系。     

里氏木霉产纤维素酶研究进展

木质纤维素类生物质被认为是重要且可持续的可再生能源,其主要组成部分是纤维素.纤维素酶是一种能将纤维素分解为葡萄糖的复合酶,能有效地降解木质纤维素生物质.真菌、细菌、放线菌、酵母等多种微生物均可以产生纤维素酶,其中里氏木霉具有完整的纤维素酶系结构,常作为生物技术领域中一个重要菌株,广泛应用于纤维素酶的商业生产.介绍了纤维...     

Lipid nanoparticle-encapsulated mRNA antibody provides long-term protection against SARS-CoV-2 in mice and hamsters

Monoclonal antibodies represent important weapons in our arsenal to against the COVID-19 pandemic. However, this potential is severely limited by the time-consuming process of developing effective antibodies and the relative high cost of manufacturing. Herein, we present a rapid and cost-effective lipid nanoparticle (LNP) encapsulated-mRNA platform for in vivo delivery of SARS-CoV-2 neutralization antibodies. Two mRNAs encoding the light and heavy chains of a potent SARS-CoV-2 neutralizing antibody HB27, which is currently being evaluated in clinical trials, were encapsulated into clinical grade LNP formulations (named as mRNA-HB27-LNP). In vivo characterization demonstrated that intravenous administration of mRNA-HB27-LNP in mice resulted in a longer circulating half-life compared with the original HB27 antibody in protein format. More importantly, a single prophylactic administration of mRNA-HB27-LNP provided protection against SARS-CoV-2 challenge in mice at 1, 7 and even 63 days post administration. In a close contact transmission model, prophylactic administration of mRNA-HB27-LNP prevented SARS-CoV-2 infection between hamsters in a dose-dependent manner. Overall, our results demonstrate a superior long-term protection against SARS-CoV-2 conferred by a single administration of this unique mRNA antibody, highlighting the potential of this universal platform for antibody-based disease prevention and therapy against COVID-19 as well as a variety of other infectious diseases.Subject terms: Biological techniques, Immunology