scholarly journals Liquid-phase ASEM imaging of cellular and structural details in cartilage and bone formed during endochondral ossification: Keap1-deficient osteomalacia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eiko Sakai ◽  
Mari Sato ◽  
Nassirhadjy Memtily ◽  
Takayuki Tsukuba ◽  
Chikara Sato

AbstractChondrogenesis and angiogenesis drive endochondral ossification. Using the atmospheric scanning electron microscopy (ASEM) without decalcification and dehydration, we directly imaged angiogenesis-driven ossification at different developmental stages shortly after aldehyde fixation, using aqueous radical scavenger glucose solution to preserve water-rich structures. An embryonic day 15.5 mouse femur was fixed and stained with phosphotungstic acid (PTA), and blood vessel penetration into the hypertrophic chondrocyte zone was visualised. We observed a novel envelope between the perichondrium and proliferating chondrocytes, which was lined with spindle-shaped cells that could be borderline chondrocytes. At postnatal day (P)1, trabecular and cortical bone mineralisation was imaged without staining. Additional PTA staining visualised surrounding soft tissues; filamentous connections between osteoblast-like cells and osteocytes in cortical bone were interpreted as the osteocytic lacunar-canalicular system. By P10, resorption pits had formed on the tibial trabecular bone surface. The applicability of ASEM for pathological analysis was addressed using knockout mice of Keap1, an oxidative-stress sensor. In Keap1−/− femurs, we observed impaired calcification and angiogenesis of epiphyseal cartilage, suggesting impaired bone development. Overall, the quick ASEM method we developed revealed mineralisation and new structures in wet bone tissue at EM resolution and can be used to study mineralisation-associated phenomena of any hydrated tissue.

2020 ◽  
Author(s):  
Lucie E Bourne ◽  
Caroline P Wheeler-Jones ◽  
Isabel R Orriss

Biomineralisation, the deposition of mineral onto a matrix, can be both a physiological and pathological process. Bone formation involves the secretion of an extracellular matrix (ECM) by osteoblasts and subsequent mineralisation of that matrix. It is regulated by a number of local and systemic factors and is necessary for maintenance of normal bone health. Conversely, mineralisation (or calcification) of soft tissues, including the vasculature, is detrimental to that tissue, leading to diseases such as arterial medial calcification (AMC). The mechanisms underlying AMC development are not fully defined, though it is thought that vascular smooth muscle cells (VSMCs) drive this complex, cell-mediated process. Similarly, AMC is regulated by a variety of enzymes and molecules, many of which have already been implicated in the regulation of bone mineralisation. This review will provide an overview of the similar, and sometimes opposing effects of these signalling molecules on the regulation of bone mineralisation and AMC.


2019 ◽  
Vol 67 (10) ◽  
pp. 723-734
Author(s):  
Chenyang Zhang ◽  
Shuai Zhang ◽  
Yao Sun

Primary cilia, hair-like organelles projecting from the surface of cells, are critical for sensing extracellular stimuli and transmitting molecular signals that regulate cell functions. During bone development, cell cilia are found in several types of cells, but their roles require further investigation. Intraflagellar transport (IFT) is essential for the formation and maintenance of most eukaryotic cilia. IFT140 is a core protein of the IFT-A complex. Mutations in IFT140 have been associated with cases of skeletal ciliopathies. In this study, we examined the expression of IFT140 during bone development. The results showed that, compared with many soft tissues, Ift140 (mRNA level) was highly expressed in bone. Moreover, its expression level was downregulated in the long bones of murine osteoporosis models. At the histological level, IFT140 was characteristically expressed in osteoblasts and chondrocytes at representative stages of bone development, and its expression level in these two types of cells was observed in two waves. These findings suggest that IFT140 may play an important role in the process of chondrogenic and osteogenic differentiation during bone development.


2006 ◽  
Vol 208 (1) ◽  
pp. 73-79 ◽  
Author(s):  
E. Tanck ◽  
G. Hannink ◽  
R. Ruimerman ◽  
P. Buma ◽  
E. H. Burger ◽  
...  

2009 ◽  
Vol 102 (3) ◽  
pp. 407-412 ◽  
Author(s):  
Susanne Eriksson ◽  
Dan Mellström ◽  
Birgitta Strandvik

Animal studies have shown that fatty acids (FA) are important for normal bone development. Human data are scanty and mostly related to diseases. We hypothesised that serum FA pattern might be related to bone mineralisation in healthy children. Serum phospholipid FA pattern was studied in relation to bone parameters in eighty-five healthy Caucasian 8-year-olds. Dual-energy X-ray absorptiometry and blood sampling for analysis of serum phospholipid FA by capillary GLC were performed on the same day. SFA concentrations were associated with bone mineral density (BMD) of the hip, lumbar spine and total body. There was a general trend that linoleic acid (LA; 18 : 2n-6) was negatively associated with BMD, since that was found both for the LA concentration, the total n-6 concentration and the ratio of n-6:n-3 FA. Arachidonic acid (AA; 20 : 4n-6) was positively correlated with bone mineral content (BMC) and BMD of total body, as was the corresponding z-score and the AA:LA ratio. Both saturated and polyunsaturated serum phospholipid FA were associated with BMC and BMD in healthy children. LA and AA were found to inversely influence bone mineralisation and the association with the n-6:n-3 ratio suggested that this balance might also be of importance. The general trend of a negative influence of high n-6 FA concentrations on bone mineralisation might be of concern in relation to the changes in the Western diet. Longitudinal studies are necessary to verify if different bone compartments and different grades of modelling are related to different FA patterns.


Author(s):  
Cathrin PFAFF ◽  
Jürgen KRIWET ◽  
Kyle MARTIN ◽  
Zerina JOHANSON

ABSTRACTCartilaginous fishes have a long evolutionary history dating back 440 million years and include model organisms in a number of fields of biological research. However, comparative developmental studies of these organisms, particularly neuroanatomical investigations, still remain sparse. Here, pre-hatching to adult developmental stages of the Little Skate, Leucoraja erinacea, are investigated using micro-computed tomography scanning in conjunction with staining procedures designed to improve visualisation of soft tissues. Within the ear, the anatomy of the skeletal labyrinth changes during ontogeny and differs substantially from the underlying membranous system, contrary to previous observations in sharks. Additionally, substantial morphological remodelling characterises the parietal fossa, which appears initially as a massive and hook-like structure and subsequently becomes slender and surrounded by soft tissue. The sizes of the vestibular system and neurocranium increase isometrically from pre- to post-hatching phases, and then exponentially after the post-hatching stages.


2014 ◽  
Vol 297 (6) ◽  
pp. 1103-1114 ◽  
Author(s):  
Astrid Slizewski ◽  
Eva Burger-Heinrich ◽  
Michael Francken ◽  
Joachim Wahl ◽  
Katerina Harvati

2019 ◽  
Author(s):  
S. Herberg ◽  
A. M. McDermott ◽  
P. N. Dang ◽  
D. S. Alt ◽  
R. Tang ◽  
...  

AbstractEndochondral ossification during long bone development and natural fracture healing initiates by mesenchymal cell condensation and is directed by local morphogen signals and mechanical cues. Here, we aimed to mimic these developmental conditions for regeneration of large bone defects. We hypothesized that engineered human mesenchymal stem cell (hMSC) condensations with in situ presentation of transforming growth factor-β1 (TGF-β1) and/or bone morphogenetic protein-2 (BMP-2) from encapsulated microparticles would promote endochondral regeneration of critical-sized rat femoral bone defects in a manner dependent on the in vivo mechanical environment. Mesenchymal condensations induced bone formation dependent on morphogen presentation, with dual BMP-2 + TGF-β1 fully restoring mechanical bone function by week 12. In vivo ambulatory mechanical loading, initiated at week 4 by delayed unlocking of compliant fixation plates, significantly enhanced the bone formation rate in the four weeks after load initiation in the dual morphogen group. In vitro, local presentation of either BMP-2 alone or BMP-2 + TGF-β1 initiated endochondral lineage commitment of mesenchymal condensations, inducing both chondrogenic and osteogenic gene expression through SMAD3 and SMAD5 signaling. In vivo, however, endochondral cartilage formation was evident only in the BMP-2 + TGF-β1 group and was enhanced by mechanical loading. The degree of bone formation was comparable to BMP-2 soaked on collagen but without the ectopic bone formation that limits the clinical efficacy of BMP-2/collagen. In contrast, mechanical loading had no effect on autograft-mediated repair. Together, this study demonstrates a biomimetic template for recapitulating developmental morphogenic and mechanical cues in vivo for tissue engineering.One Sentence SummaryMimicking aspects of the cellular, biochemical, and mechanical environment during early limb development, chondrogenically-primed human mesenchymal stem cell condensations promoted functional healing of critical-sized femoral defects via endochondral ossification, and healing rate and extent was a function of the in vivo mechanical environment.


2020 ◽  
Vol 21 (7) ◽  
pp. 2636
Author(s):  
Matthew Kirkham ◽  
Austen Kalivas ◽  
Kaniz Fatema ◽  
Sarah Luelling ◽  
Brooke H. Dubansky ◽  
...  

Synovial sarcoma, an uncommon cancer, typically affects young adults. Survival rates range from 36% to 76%, decreasing significantly when metastases are present. Synovial sarcomas form in soft tissues, often near bones, with about 10% demonstrating ossification in the tumor. The literature is inconclusive on whether the presence of ossification portends a worse prognosis. To this end, we analyzed our genetic mouse models of synovial sarcoma to determine the extent of ossification in the tumors and its relationship with morbidity. We noted higher ossification within our metastatic mouse model of synovial sarcoma. Not only did we observe ossification within the tumors at a frequency of 7%, but an even higher frequency, 72%, of bone reactivity was detected by radiography. An enrichment of bone development genes was associated with primary tumors, even in the absence of an ossification phenotype. In spite of the ossification being intricately linked with the metastatic model, the presence of ossification was not associated with a faster or worse morbidity in the mice. Our conclusion is that both metastasis and ossification are dependent on time, but that they are independent of one another.


1978 ◽  
Vol 56 (11) ◽  
pp. 1315-1325 ◽  
Author(s):  
E. Schnepf ◽  
G. Deichgräber ◽  
G. Drebes

Fine structural details of antheridia and oogonia, of cytogamy, plasmogamy, and karyogamy, and finally of the development of the oospore are described. Sexually determined zoospores (most probably zoomeiospores) resemble vegetative primary zoospores (zoomitospores). They form gametangia (antheridia or oogonia) which are similar to vegetative primary cysts. An antheridium germinates with a fertilization tube which penetrates the oogonium. As seen in abnormal cell fusions, the tip of the fertilization tube opens only within an oogonium; presumably, its wall is disintegrated by the latter. Before plasmogamy, both plasmalemmata are closely appressed. The fused protoplasts move into a short zygotial hypha which protudes from the oogonium. The thick-walled oospore is formed herein. It includes nearly all of the cytoplasm of the gametangia. Karyogamy takes place within the developing oospore. It is initiated by an interdigitation of microtubules radiating from the centrioles and by a close association of the latter. The observations are compared with those on other developmental stages of Lagenisma and with those on gametangia and oospores of other Oomycetes.


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