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Osteocyte Gene Expression Analysis in Mouse Bone: Optimization of a Laser-assisted Microdissection Protocol

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Journal JBMR Plus
Date 2024 Jul 24
PMID 39045129
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Abstract

Among bone cells, osteocytes are the most abundant, but also the most challenging to study because they are located inside a dense mineralized matrix. Due to their involvement in bone homeostasis, diverse tools are needed to understand their roles in bone physiology and pathology. This work was aimed at establishing a laser-assisted microdissection protocol to isolate osteocytes and analyze their gene expressions. The goal was to overcome the limitations of the technique currently most used: RNA extraction from the whole bone. To perform laser microdissection and subsequent gene expression analysis, the five main steps of the protocol have been adapted for the bone tissue. After testing many parameters, we found that the best options were (1) take unfixed snap-frozen tissue, (2) cryosection with a supported tape system to improve the tissue morphology if necessary, (3) microdissect regions of interest, and (4) recover the bone pieces by catapulting, if feasible, or by gravity. Finally, RNA extraction (5) was the most efficient with a precipitation method and allowed quantifying the expression of well described osteocyte genes (, , , , ). This work describes two protocols optimized for femur and calvaria and gives an overview of the many optimization options that one could try when facing difficulties with laser microdissection.

References
1.
Bustin S, Benes V, Garson J, Hellemans J, Huggett J, Kubista M . The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments. Clin Chem. 2009; 55(4):611-22. DOI: 10.1373/clinchem.2008.112797. View

2.
Spatz J, Wein M, Gooi J, Qu Y, Garr J, Liu S . The Wnt Inhibitor Sclerostin Is Up-regulated by Mechanical Unloading in Osteocytes in Vitro. J Biol Chem. 2015; 290(27):16744-58. PMC: 4505423. DOI: 10.1074/jbc.M114.628313. View

3.
Shibutani M, Uneyama C, Miyazaki K, Toyoda K, Hirose M . Methacarn fixation: a novel tool for analysis of gene expressions in paraffin-embedded tissue specimens. Lab Invest. 2000; 80(2):199-208. DOI: 10.1038/labinvest.3780023. View

4.
Benoyahu D, Akavia U, Socher R, Shur I . Gene expression in skeletal tissues: application of laser capture microdissection. J Microsc. 2005; 220(Pt 1):1-8. DOI: 10.1111/j.1365-2818.2005.01511.x. View

5.
Golubeva Y, Smith R, Sternberg L . Optimizing Frozen Sample Preparation for Laser Microdissection: Assessment of CryoJane Tape-Transfer System®. PLoS One. 2013; 8(6):e66854. PMC: 3689705. DOI: 10.1371/journal.pone.0066854. View