Name: पारदर्शी ऊतकों और कैल्वरियल हड्डियों को तैयार करने के लिए पेगासोस विधि
Uploaded: 2023-08-18T12:00:00
Description: Watch this Scientific Journal Video about PEGASOS Method to Prepare Transparent Tissues and Calvarial Bones at JoVE.com

pegasos method to prepare transparent tissues and calvarial bones

सिवनी विस्तार चूहों में तन्यता लोड के तहत हड्डी रीमॉडेलिंग का 3 डी दृश्य

Craniofacial sutures are fibrous tissues that connect craniofacial bones and play essential roles in the growth and remodeling of craniofacial bones. The structure of the suture resembles a river, providing a flow of cell resources to nourish and build the &#34;river bank&#34;, known as the osteogenic fronts, which contribute to the formation of craniofacial bones via intramembranous osteogenesis1.
Interest in craniofacial sutures has been driven by clinical needs to understand premature closure of cranial sutures and facial suture dysfunction, which may lead to craniofacial deformities and even life-threatening conditions in children. Open suturectomy is routinely used in clinical treatment, but long-term follow-up has shown incomplete re-ossification recurrence in some patients2. Minimally invasive craniotomy assisted by expansion springs or endoscopic stripe craniectomy may provide a safer approach to preserving the potential suture rather than discarding the tissues3. Similarly, orthopedic therapies such as facemasks and expansion appliances have been widely used to treat sagittal or horizontal maxillary hypoplasia, with some studies extending the age limitation to treat adult patients via miniscrew-assisted palatal expanders4,5,6. Additionally, cranial suture regeneration with mesenchymal stem cells (MSCs) combined with biodegradable materials is a potential therapy in the future, offering a novel direction for the treatment of related diseases7. However, the function process or regulatory mechanism of sutures remains elusive.
Bone remodeling mainly consists of a balance between bone formation conducted by osteoblasts and bone resorption conducted by osteoclasts, where osteogenic differentiation of stem cells stimulated by mechanical signals plays an important role. After decades of research, it has been found that craniofacial sutures are highly plastic mesenchymal stem cell niches8. Suture stem cells (SuSCs) are a heterogeneous group of stem cells, belonging to mesenchymal stem cells (MSCs) or bone stem cells (SSCs). SuSCs are labeled in vivo by four markers, including Gli1, Axin2, Prrx1, and Ctsk. Gli1+ SuSCs, in particular, have strictly verified the biological characteristics of stem cells, not only exhibiting high expression of typical MSC markers but also demonstrating excellent osteogenic and chondrogenic potential9. Previous research has shown that Gli1+ SuSCs actively contribute to new bone formation under tensile force, identifying them as the suture stem cell source supporting distraction osteogenesis10.
In the past, extensive mechanical characteristics of stem cells were studied in vitro via Flexcell, four-point bending, micro-magnet loading system, and others. Although mouse cranial suture-derived mesenchymal cells have been identified in vitro11, and human suture mesenchymal stem cells have also been isolated recently12, the biomechanical response of suture cells remains unclear in the in vitro system. To further investigate the bone remodeling process, a suture expansion model based on isolated calvaria organ culture has been established, paving the way for establishing a useful in vivo suture expansion model1,13. Rabbits14 and rats15 have been the most widely used animals in basic research for suture expansion. However, mice are preferred animal models for exploring human disease due to their highly homologous genome with humans, numerous gene modification lines, and strong reproductive hybridization ability. Existing mouse models of cranial suture expansion typically rely on stainless steel orthodontic spring wires to apply tensile force to the sagittal suture16,17. In these models, two holes are made in each side of the parietal bones to fix the expansion device, and the wires are embedded under the skin, which may affect the cell activation mode.
Regarding the visualization method, the two-dimensional observation of slices in the sagittal direction has been generally adopted for decades. However, considering that bone remodeling is a complex three-dimensional dynamic process, obtaining complete three-dimensional information has become an urgent need. The PEGASOS tissue transparency technique emerged to meet this requirement18,19. It offers unique advantages for the transparency of hard and soft tissues, enabling the complete bone remodeling process to be reproduced in three-dimensional space.
To gain a deeper and more comprehensive understanding of the physiological changes in the bone remodeling periods, a standard sagittal suture expansion mouse model with a spring setting between the handmade holders was established10. With a standardized acid etching and bonding procedure, the expansion device could be firmly bonded to the cranial bone, generating a tensile force perpendicular to the sagittal suture. Furthermore, the PEGASOS tissue clearing method was applied after double labeling of the mineralized bone post-expansion to fully visualize the bone modeling changes after suture expansion.

लेखक स्पॉटलाइट: पेगासोस ऊतक समाशोधन तकनीक अस्थि रीमॉडेलिंग की कल्पना करने के लिए 

एक सिवनी विस्तार माउस मॉडल में हड्डी रीमॉडेलिंग के लिए एक 3-डी दृश्य तकनीक

The interest in craniofacial sutures has been driven by the clinical needs to understand the mechanisms of orthodontic and the orthopedic treatment. The scope of our study is to establish a standardized suture expansion mouse model, and the 3D visualization method to study the mechanobiological changes of suture and bone remodeling upon expansion. PEGASOS tissue clearing technique has been combined with various labeling methods to obtain versatile information of suture and bond remodeling in space perspective.This model is suitable for various strengths of transgenic mice of different age. It is convenient to adjust the magnitude of tensile stress and withdraw force at any time. With the PEGASOS technique, we can observe the three dimensional spatial temporal distribution of cranial suture stem cells during bone remodeling.With the PEGASOS technique, we will further explore the relationship between suture stem cells and mechanical stress, as well as its specific mechanisms.

Watch this Scientific Journal Video about PEGASOS Method to Prepare Transparent Tissues and Calvarial Bones at JoVE.com

पारदर्शी ऊतकों और कैल्वरियल हड्डियों को तैयार करने के लिए पेगासोस विधि 

शुरू करने के लिए, चिपकने वाला टेप के साथ एक संवेदनाहारी माउस के अंगों को ठीक करें। पेट की त्वचा को ऊपर की ओर पकड़ें और इसे पूरी तरह से उजागर करने के लिए वक्ष की परिधि के साथ सावधानी से काट लें। नेत्र कैंची के साथ सही आलिंद में एक छोटे से कटौती करें और तुरंत बाएं वेंट्रिकल के शीर्ष पर एक छिड़काव 22 गेज सुई डालें.फिर सिरिंज के माध्यम से 30 से 50 मिलीलीटर कार्डियक परफ्यूजन तरल पदार्थ को धक्का दें। सही आलिंद से बहिर्वाह तरल पदार्थ पूरी तरह से स्पष्ट हो जाता है के बाद, 4% पीएफए समाधान के बराबर मात्रा में डालना. ऊतकों और अंगों काटना और उन्हें चार डिग्री सेल्सियस पर 4% पीएफए के साथ रात भर फिक्स.ऊतक डीकैल्सीफिकेशन को प्रेरित करने के लिए। 37 डिग्री सेल्सियस पर एक मिलाते हुए मेज पर EDTA समाधान के 10 मिलीलीटर में तय हृदय ऊतक रखें। लगभग दो दिनों के लिए सेते हैं और तरल पदार्थ को दैनिक बदलते हैं।ऊतक decolorization के लिए 25% Quadrol समाधान के 20 मिलीलीटर में तय calvaria हड्डियों रखें. एक दिन के लिए 37 डिग्री सेल्सियस पर एक मिलाते हुए मेज पर सेते हैं और एक बार तरल पदार्थ बदल जाते हैं. अगला, ऊतक क्रमिक 30% तृतीयक-Butanol या टीबी समाधान में जगह है.फिर 50% टीबी समाधान, और फिर 70% टीबी समाधान ढाल घटने के लिए। इसके बाद 37 डिग्री सेल्सियस पर एक मिलाते हुए मेज पर छह घंटे के लिए नमूने और टीबी खूंटी समाधान निर्जलीकरण. अंत में, 37 डिग्री सेल्सियस पर एक मिलाते हुए मेज पर बीबी खूंटी समाधान में पूरी तरह से निर्जलित ऊतक रखें.इनक्यूबेशन के दो से चार घंटे के बाद, ऊतक पारदर्शी हो जाएगा. पेगासोस ऊतक समाशोधन विधि के परिणामस्वरूप पारदर्शी ऊतक हुआ। पूरे माउंट EDU धुंधला के साथ साफ ऊतक से पता चला कि लेबलिंग कुशल और अच्छी तरह से संरक्षित थी।नियंत्रण समूह में, कई ईडीयू सकारात्मक कोशिकाओं को पूरे टांके में वितरित किया गया था। सिवनी विस्तार के एक दिन के बाद, सिवनी के मध्य और किनारों में प्रसार कोशिकाओं मनाया गया. जैसे-जैसे सिवनी चौड़ी होती गई, समय के साथ प्रसार करने वाली कोशिकाओं की संख्या कम होती गई।हरे रंग की लेबल वाली कोशिकाएं अस्थि मज्जा में छोटी गोल कोशिकाएं थीं, जो ईडीयू पॉजिटिव सिवनी कोशिकाओं से भिन्न थीं।

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JoVE Journal

Biology

PEGASOS Method to Prepare Transparent Tissues and Calvarial Bones

A 3-D Visualization Technique for Bone Remodeling in a Suture Expansion Mouse Model

Craniofacial sutures play a crucial role beyond being fibrous joints connecting craniofacial bones; they also serve as the primary niche for calvarial and ...