Background & Aims
Identifying which nociceptors are expressed in the innervation of a pathophysiology is key to discover new therapies. This also goes for endometriosis, where pelvic oestrogen-responsive endometrium-like lesions grow in an inflammatory environment and attain sensory innervation. Transient receptor potential (TRP) channels, like TRPV1 and TRPA1 have already been suggested to play a role. However, another member, TRPM3, could also be a potential contributor in endometriosis-associated pain. This calcium-permeable channel is expressed in sensory innervation and has a role in inflammatory hyperalgesia. Moreover, nerve endings innervating inflamed tissue show increased TRPM3 expression at the DRG level. Therefore, we aim to investigate (i) if TRPM3 is functionally expressed in the innervation of murine endometriosis lesions via ex vivo calcium microfluorimetry and (ii) the effect of the inflammatory environment of endometriotic lesions on the DRG expression level of sensory TRP channels.
Methods
Endometriosis is induced by intra peritoneal injection of murine wild type menstrual endometrial tissue in Trpv1-CrexGCaMP3 mice, rendering wild type endometriosis lesions innervated by GCaMP3 positive nerve fibres after 12 weeks. Confocal ex vivo calcium imaging is performed, after excision of the lesions from the surrounding organs, to assess the functionality of TRPM3 by the application of agonists (100 ?M PS + 1 ?M CIM0216) and antagonists (20 µM isosakuranetin). To investigate TRPM3 expression at the DRG level, endometriosis was induced in wild type mice. After 12 weeks, laparotomy is performed to retrograde label the endometriotic lesions by injection of WGA-Alexa 647. This enables the retracing of the endometriosis innervation to the DRG. After one week, DRG neurons were harvested and, RNA scope experiments are performed to quantify mRNA expression of sensory TRP channels in labelled DRG neurons.
Results
Preliminary results show the presence of functional TRPM3 in the innervation of murine endometriosis lesions. Local increases in fluorescence upon application of PS+CIM0216 can be observed, which are reduced when the same application was performed in the presence of the TRPM3 inhibitor isosakuranetin.
Conclusions
Our preliminary data show for the first-time the expression of TRPM3 in the innervation of endometriotic lesions. Moreover, we will show the influence of the inflammatory environment on TRPM3 expression. Together, these results could point towards TRPM3 as potential target for treatment of endometriosis-associated pain.
References
Vriens J, Owsianik G, Hofmann T, et al. TRPM3 is a nociceptor channel involved in the detection of noxious heat. Neuron. 2011;70(3):482-494. doi:10.1016/j.neuron.2011.02.051
Mulier M, Van Ranst N, Corthout N, et al. Upregulation of TRPM3 in nociceptors innervating inflamed tissue. Elife. 2020;9:e61103. Published 2020 Sep 3. doi:10.7554/eLife.61103
Presenting Author
Eleonora Persoons
Poster Authors
Eleonora Persoons
PhD
KU Leuven
Lead Author
Katrien De Clercq
Department of Development and Regeneration, KU Leuven
Lead Author
Nikky Corthout
BioImaging Core Leuven - VIB Center for Brain and Disease Research
Lead Author
Thomas Voets
PhD
Laboratory of Ion Channel Research, KU Leuven; IB Center for Brain & Disease Research
Lead Author
Joris Vriens
Laboratory of Ion Channel Research, KU Leuven
Lead Author
Topics
- Specific Pain conditions/Pain in Specific Populations: Gynecological Pain