Piezo1 promote macrophage-to-myofibroblast transition and bladder fibrosis in neurogenic bladder

Neurogenic bladder (NB) frequently leads to bladder fibrosis, yet the underlying mechanisms remain unclear. Piezo1, a mechanosensitive ion channel, has been implicated in fibrotic processes. This study investigated whether Piezo1 promotes macrophage-to-myofibroblast transition (MMT) and contributes to bladder fibrosis in NB.

A mouse NB model was established via spinal cord injury. Bladder tissues were analyzed by HE and Masson staining, immunohistochemistry, qRT-PCR, and Western blot to assess fibrosis and Piezo1 expression. Immunofluorescence colocalization and flow cytometry were used to evaluate MMT. In vitro, RAW264.7 macrophages were treated with TGF-β1, the Piezo1 agonist Yoda1, the Piezo1 inhibitor GsMTx4, or Piezo1 siRNA, followed by assessment of MMT and fibrosis-related protein expression.

Piezo1 expression was significantly upregulated in NB bladder tissues, correlating with increased collagen deposition and fibronectin expression. Immunofluorescence revealed colocalization of macrophage markers (CD68, F4/80) with α-SMA, indicating MMT in NB tissues. In vitro, TGF-β1-induced MMT was enhanced by Yoda1 and attenuated by GsMTx4 or Piezo1 knockdown, as confirmed by immunofluorescence and flow cytometry. Similarly, Piezo1 activation increased the expression of fibrosis-related proteins (Fibronectin, Collagen I, α-SMA), whereas Piezo1 inhibition suppressed their expression.

Piezo1 is a critical regulator of macrophage-to-myofibroblast transition and promotes bladder fibrosis in neurogenic bladder. Targeting Piezo1 may represent a potential therapeutic strategy to mitigate fibrosis and preserve bladder function in NB patients.