TGF-β/BMP signaling and other molecular events: regulation of osteoblastogenesis and bone formation

Transforming growth factor-beta（TGF-β）/bone morphogenetic protein（BMP） plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-β/BMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-β（I/II） or BMP receptors activates intracellular downstream Smads, the transducer of TGF-β/BMP signals. This signaling is modulated by various factors and pathways, including transcription factor Runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space specific.Additive, positive, negative, or synergistic effects are observed when TGF-β/BMP interacts with the pathways of MAPK, Wnt, Hedgehog（Hh）, Notch, Akt/m TOR, and mi RNA to regulate the effects of BMP-induced signaling in bone dynamics. Accumulating evidence indicates that Runx2 is the key integrator, whereas Hh is a possible modulator, mi RNAs are regulators, and b-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of BMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-β/BMP function and regulation that could allow understanding the complexity of bone tissue dynamics.

The Quasi-Parabolic Regulation of the Standard Free Energies of Formation of Binary Intermediate Compounds

In this paper it has theoretically proved that the relationship of the molar atomic standard free energies of formation of binary intermediate compounds to the molar fraction of component is a quasi-parabola which is called a quasi-parabolic regula- tion.

RANKL signaling in bone marrow mesenchymal stem cells negatively regulates osteoblastic bone formation

RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of BMSCs.Interestingly, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.

RANKL-RANK signaling regulates osteoblast differentiation and bone formation

In the recent two decades, it has been well elucidated that receptor activator of nuclear factor-κB ligand （RANKL; also known as TNFSF11） binding to its receptor RANK （also known as TNFRSF11A） drives osteoclast development as the crucial signaling pathway.;However, accumulating evidence also implies that

Woody plant cell walls:Fundamentals and utilization

Cell walls in plants,particularly forest trees,are the major carbon sink of the terrestrial ecosystem.Chemical and biosynthetic features of plant cell walls were revealed early on,focusing mostly on herbaceous model species.Recent developments in genomics,transcriptomics,epigenomics,transgenesis,and associated analytical techniques are enabling novel insights into formation of woody cell walls.Here,we review multilevel regulation of cell wall biosynthesis in forest tree species.We highlight current approaches to engineering cell walls as potential feedstock for materials and energy and survey reported field tests of such engineered transgenic trees.We outline opportunities and challenges in future research to better understand cell type biogenesis for more efficient wood cell wall modification and utilization for biomaterials or for enhanced carbon capture and storage.

Transcriptional Regulation of Secondary Growth and Wood Formation

Secondary growth and wood formation are products of the vascular cambium, a lateral meristem. Although the mechanisms have only recently begun to be uncovered, transcriptional regulation appears increasingly central to the regulation of secondary growth. The importance of transcriptional regulation is illustrated by the correlation of expression of specific classes of genes with related biological processes occurring at specific stages of secondary growth, including cell division, cell expansion, and cell differentiation. At the same time, transcription factors have been characterized that affect specific aspects of secondary growth, including regulation of the cambium and differentiation of cambial daughter cells. In the present review, we summarize evidence pointing to transcription as a major mechanism for regulation of secondary growth, and outline future approaches for comprehensively describing transcriptional networks underlying secondary growth.

Electrical coupling regulates layer 1 interneuron microcircuit formation in the neocortex

With the support by the National Natural Science Foundation of China,the research team led by Prof.Yu Yongchun(禹永春)at the Institutes of Brain Science,Fudan University,revealed the vital roles of electrical coupling in chemical synapse formation between interneurons,which was published in Nature Communications(2016,7:12229,DOI:10.1038).Although the excitatory neurons in the neocortex are electrically coupled only during early development,