Summary

מהיר<em> באתר</em> הכלאה באמצעות oligonucleotide בדיקות במוח-התחילית Paraformaldehyde של חולדות עם סרוטונין תסמונת

Published: September 23, 2015
doi:

Summary

This protocol describes a rapid and simplified in situ hybridization method ideal forparaformaldehyde-prefixed brain, thus reducing the need for prolonged complex steps while using fresh frozen tissues. The method is validated using the identification of the serotonin 5-HT2A receptor gene htr2a in rats.

Abstract

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) toxicity may cause region-specific changes in serotonergic mRNA expression due to acute serotonin (5-hydroxytryptamine; 5-HT) syndrome. This hypothesis can be tested using in situ hybridization to detect the serotonin 5-HT2A receptor gene htr2a. In the past, such procedures, utilizing radioactive riboprobe, were difficult because of the complicated workflow that needs several days to perform and the added difficulty that the technique required the use of fresh frozen tissues maintained in an RNase-free environment. Recently, the development of short oligonucleotide probes has simplified in situ hybridization procedures and allowed the use of paraformaldehyde-prefixed brain sections, which are more widely available in laboratories. Here, we describe a detailed protocol using non-radioactive oligonucleotide probes on the prefixed brain tissues. Hybridization probes used for this study include dapB (a bacterial gene coding for dihydrodipicolinate reductase), ppiB (a housekeeping gene coding for peptidylprolyl isomerase B), and htr2a (a serotonin gene coding for 5-HT2A receptors). This method is relatively simply, cheap, reproducible and requires less than two days to complete.

Introduction

Serotonin (5-hydroxytryptamine; 5-HT) syndrome is an acute neurologic disorder caused by 5-HT-promoting drugs such as antidepressants1, while also occurring in situations of MDMA use for recreational purposes2. Molecular mechanisms responsible for mood swings, learning and memory deficits that occur in association with the acute syndrome are not well understood3,4. In situ hybridization is a powerful research tool allowing the detection and quantification of specific mRNAs expressed potentially at a single-cell level. The conventional way to perform in situ hybridization is to utilize a radioactive-labeled riboprobe that specifically hybridizes the gene of interest. However, a major drawback is that the method requires complicated and time-consuming probe preparation and hybridization steps, as well as access to fresh frozen tissues maintained in an RNase-free environment5,6.

Oligonucleotide probes have been recently developed to hybridize shorter RNA fragments than those required for riboprobes7. Furthermore, the probes produce a low background signal without sacrificing specificity8. This newly-developed probe technology can be used in situ hybridization on paraformaldehyde-prefixed brain tissues commonly available in immunocytochemical laboratories.

Here, we describe a protocol for in situ hybridization using oligonucleotide probes on paraformaldehyde-prefixed rat brain and compare findings with those noted in a fresh frozen brain5,6. This protocol is used to test the hypothesis that MDMA substance abuse causes changes in 5-HT2A receptor gene htr2a mRNA in the brain. We began the procedure with MDMA treatment followed by paraformaldehyde tissue perfusion of the animal, in situ hybridization of the thr2a probe, and data analysis. Note that dapB (the bacterial gene coding for dihydrodipicolinate reductase) is used as a negative control, and ppiB (housekeeping gene coding for peptidylprolyl isomerase B) as a positive control.

Protocol

נהלי שימוש בבעלי חיים מתוארים להלן אושרו על ידי הוועדה המוסדית הטיפול בבעלי חיים והשימוש (IACUC) באוניברסיטת רוס לרפואת וטרינרית ואוניברסיטת פלורידה אטלנטיק. למרות טכניקות וכפפות סטריליות נדרשות, הסביבה נטול RNase אין צורך בעת השימוש בפרוטוקול זה. <p class="jove_title" style=";text-al…

Representative Results

שימוש בבדיקות RNA oligonucleotide (<25 NT), הכלאה יכולה להתגלות כנקודות אדומות בתאי ההיפותלמוס הוכנו מהמוח הקפוא-התחילית paraformaldehyde וטרי. מולקולות mRNA htr2a נמצאות בכמה תאים (המסומנים בחצים מוצקים), אך לא לאחרים (חיצים פתוחים). הבחנו כי אין הבדל בין-התחילית paraformaldehyde והרקמות קפוא…

Discussion

One of the major concerns of in situ hybridization test is to choose appropriate techniques used for RNA preservation because of RNase enzymes. It is well known that these enzymes are widely present in the cells and environment which can affect the results. However, enzyme activity can be quickly distinguished by placing the tissue in the dry ice/alcohol solution5,12. Although quick preservation is critical for hybridization using a riboprobe13, little is known about experimental conditions…

Offenlegungen

The authors have nothing to disclose.

Acknowledgements

מחקר זה נתמך על ידי מענק NIH (R15DA029863), מענק אוניברסיטת פלורידה אטלנטיק מחקר לתואר ראשון (M30014) ואוניברסיטת רוס של מענק מחקר לרפואת הווטרינרית. ברצוננו להודות למכון הלאומי לשימוש בסמים (Rockville, MD) למתן (±) 3,4-methylenedioxymethamphetamine (± MDMA) עבור עבודה זו.

Materials

RNAscope Negative Control Probe-DapB Advanced cell diagnostic, INC 310098
RNAscope Pretreat 4 Advanced cell diagnostic, INC 320046
RNAscope 2.0 HD Reagent Kit – Red Advanced cell diagnostic, INC 310036
RNAscope Probe – Rn-Ppib Advanced cell diagnostic, INC 313921
Rat Htr2a Advanced cell diagnostic, INC 300031
Cryostat Leica CM 1850
Horizontal shaker VWR 88032-088
Hybridization oven Thermo Fisher Scientific 222000
Superfrost Plus microscope slide Fisher Scientific 12-550-15
Hydrophobic pen Vector H-4000
Microscope Olympus Provis AX70

Referenzen

  1. Muzyk, A. J., Jakel, R. J., Preud’homme, X. Serotonin syndrome after a massive overdose of controlled-release paroxetine. Psychosomatics. 51, 437-442 (2010).
  2. Davies, O., Batajoo-Shrestha, B., Sosa-Popoteur, J., Olibrice, M. Full recovery after severe serotonin syndrome, severe rhabdomyolysis, multi-organ failure and disseminated intravascular coagulopathy from MDMA. Heart Lung. 43, 117-119 (2014).
  3. Bosch, O. G., et al. Verbal memory deficits are correlated with prefrontal hypometabolism in 18FDG PET of recreational MDMA users. PLoS On. 8, e61234 (2013).
  4. Smithies, V., Broadbear, J., Verdejo-Garcia, A., Conduit, R. Dysfunctional overnight memory consolidation in ecstasy users. J Psychopharmaco. 28, 751-762 (2014).
  5. Winzer-Serhan, U. H., Broide, R. S., Chen, Y., Leslie, F. M. Highly sensitive radioactive in situ hybridization using full length hydrolyzed riboprobes to detect α2 adrenoceptor subtype mRNAs in adult and developing rat brain. Brain Res Brain Res Proto. 3, 229-241 (1999).
  6. Zoeller, R. T., Fletcher, D. L., Butnariu, O., Lowry, C. A., Moore, F. L. N-ethylmaleimide (NEM) can significantly improve in situ hybridization results using 35S-labeled oligodeoxynucleotide or complementary RNA probes. J Histochem Cytoche. 45, 1035-1041 (1997).
  7. Wang, F., et al. RNAscope: a novel in situ RNA analysis platform for formalin-fixed, paraffin-embedded tissues. J Mol Diag. 14, 22-29 (2012).
  8. Wang, H., et al. RNAscope for in situ detection of transcriptionally active human papillomavirus in head and neck squamous cell carcinoma. J Vis E. , (2014).
  9. Gage, G. J., Kipke, D. R., Shain, W. Whole animal perfusion fixation for rodents. J Vis E. , (2012).
  10. Mishra, A., et al. Imaging pericytes and capillary diameter in brain slices and isolated retinae. Nat Proto. 9, 323-336 (2014).
  11. Shi, S. R., Cote, R. J., Taylor, C. R. Antigen retrieval techniques: current perspectives. J Histochem Cytoche. 49, 931-937 (2001).
  12. Qin, Y., Heine, V. M., Karst, H., Lucassen, P. J., Joels, M. Gene expression patterns in rat dentate granule cells: comparison between fresh and fixed tissue. J Neurosci Method. 131, 205-211 (2003).
  13. Carter, B. S., Fletcher, J. S., Thompson, R. C. Analysis of messenger RNA expression by in situ hybridization using RNA probes synthesized via in vitro transcription. Method. 52, 322-331 (2010).
  14. Mijnster, M. J., et al. Regional and cellular distribution of serotonin 5-hydroxytryptamine2a receptor mRNA in the nucleus accumbens, olfactory tubercle, and caudate putamen of the rat. J Comp Neuro. 389, 1-11 (1997).
  15. Li, Q., et al. Brain region-specific alterations of 5-HT2A and 5-HT2C receptors in serotonin transporter knockout mice. J Neuroche. 84, 1256-1265 (2003).
  16. Horner, K. A., Gilbert, Y. E., Noble, E. S. Differential regulation of 5-HT2A receptor mRNA expression following withdrawal from a chronic escalating dose regimen of D-amphetamine. Brain Re. 1390, 10-20 (2011).
  17. Mocci, G., Jimenez-Sanchez, L., Adell, A., Cortes, R., Artigas, F. Expression of 5-HT2A receptors in prefrontal cortex pyramidal neurons projecting to nucleus accumbens. Potential relevance for atypical antipsychotic action. Neuropharmacolog. 79, 49-58 (2014).
  18. Reneman, L., et al. The acute and chronic effects of MDMA (‘Ecstasy’) on cortical 5-HT2A receptors in rat and human. 26, 387-396 (2002).
check_url/de/53165?article_type=t

Play Video

Diesen Artikel zitieren
Shokry, I. M., Callanan, J. J., Sousa, J., Tao, R. Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome. J. Vis. Exp. (103), e53165, doi:10.3791/53165 (2015).

View Video