Neuropeptides Substance P and CGRP Drive Endometriosis Scarring and Growth

Researchers used cultured endometriotic stromal cells treated with substance P, CGRP, or rat dorsal root ganglia supernatant to study cellular transformations in vitro. They also performed immunohistochemistry on human endometriosis lesion samples comparing deep endometriosis to ovarian endometriomas, measuring nerve fiber density, receptor expression, and fibrotic markers including α-SMA, desmin, and smooth muscle myosin heavy-chain.

Endometriosis affects roughly 10% of women of reproductive age and current treatments are limited. This study reveals that sensory nerves don't just transmit pain — they actively drive disease progression through neuropeptide signaling. This opens the door to targeting substance P and CGRP receptors as a therapeutic strategy, potentially treating both the pain and the underlying tissue damage of endometriosis.

This research bridges two fields — neuropeptide biology and endometriosis — by showing that sensory nerves actively participate in disease progression, not just pain perception. With CGRP-targeting drugs already approved for migraine and substance P antagonists available, there may be existing medications that could be repurposed for endometriosis. This also supports the emerging view that endometriosis lesions behave like chronic wounds undergoing repeated injury and repair.

The in vitro cell culture experiments may not fully replicate the complex microenvironment of endometriosis in vivo. The human tissue analysis was observational and correlational — it shows association between nerve density and fibrosis but doesn't prove causation in living patients. No clinical intervention was tested, so it remains unknown whether blocking these receptors would reduce fibrosis in patients with endometriosis.