Lin D. et al., 2026: . Inhibition of Ferroptosis in Prostatitis Model by Low Intensity Extracorporeal Shock Wave Therapy through the Integrin-β1/NRF2 Axis.

Lin D, Li K, Kuang W, Chen Z, Zhang M.
World J Mens Health. 2026 Apr;44(2):451-468. doi: 10.5534/wjmh.250222

Abstract

Purpose: Although low-intensity extracorporeal shock wave therapy (Li-ESWT) is used clinically for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), its mechanisms remain inadequately understood. This study aimed to explore Li-ESWT-mediated mechanotransduction signaling and its association with ferroptosis in CP/CPPS models.

Materials and methods: Experimental autoimmune prostatitis (EAP) was induced by intradermal prostate antigen immunization. Rats received Li-ESWT, with additional groups treated with the ferroptosis inducer RAS-selective lethal 3 (RSL3) or iron chelator deferoxamine (DFO). The rats were analyzed histologically and biochemically to assess immune responses, fibrosis, oxidative stress, ferroptosis markers, and related signaling. In vitro, Li-ESWT was applied to lipopolysaccharide (LPS)-stimulated RWPE-1 cells. The Integrin-β1-NRF2-xCT/GPX4 axis was modulated via siRNA or overexpression plasmid, with Ferrostatin-1 used as a reference control. The changes in NRF2-xCT/GPX4 expression, ferrous iron, and lipid peroxidation were evaluated to clarify the mechanisms by which Li-ESWT regulates ferroptosis.

Results: EAP rats recapitulated key pathological features of CP/CPPS, which were alleviated by Li-ESWT. Specifically, Li-ESWT reduced the inflammatory response by inhibiting CD3⁺ T cells and CD68⁺ macrophages infiltration, suppressed fibrosis by preventing epithelial-mesenchymal transition and smooth muscle hyperplasia, and attenuated hyperalgesia by inhibiting mast cell degranulation. RSL3 exacerbated these pathological changes, whereas DFO attenuated them. Li-ESWT also suppressed oxidative stress and ferroptosis, as indicated by reduced reactive oxygen species and ferrous iron accumulation, lipid peroxidation, and ferroptosis-driving factors (ACSL4, LPCAT3, ALOX15, COX-2) levels. Li-ESWT also upregulated the Integrin-β1 and NRF2-xCT/GPX4 expression. In vitro, Integrin-β1 knockdown reduced NRF2, xCT, and GPX4 expression, abolishing the protective effects of Li-ESWT against LPS-induced ferroptosis, as evidenced by increased lipid peroxidation and ferrous iron accumulation. Similarly, NRF2 knockdown negated the anti-ferroptotic effect of Li-ESWT, whereas ectopic overexpression of xCT/GPX4 restored ferroptosis suppression.

Conclusions: Li-ESWT ameliorates inflammation, fibrosis, hyperalgesia in the CP/CPPS model, likely through ferroptosis mitigation via activating the Integrin-β1/NRF2 pathway.

Comment Jens Rassweiler

The authors want to clarify the following question: Does Li-ESWT alleviate chronic prostatitis/CPPS by inhibiting ferroptosis, and if so, through which mechanotransduction pathway? For this issue, the authors specifically tested whether the pathway involves:

Li-ESWT → Integrin-β1 → NRF2 → xCT/GPX4 → ferroptosis inhibition

Experimental Design

The authors used

1. An animal model: Male Wistar rats were divided into several groups, including:

• Normal control
• Normal control + Li-ESWT
• EAP model (experimental autoimmune prostatitis model)
• EAP + Li-ESWT
• EAP + DFO (deferoxamine, an iron chelator and ferroptosis inhibitor)
• Normal control + RSL3 (ferroptosis inducer that inhibits GPX4)
• EAP + RSL3
• EAP + RSL3 + Li-ESWT

2. A cell model: Human prostate epithelial RWPE-1 cells were treated with:

• LPS to induce inflammatory stress
• Li-ESWT
• Fer-1 as a ferroptosis inhibitor
• siRNA knockdown of Integrin-β1 or NRF2
• xCT/GPX4 overexpression plasmids

Results

1. Li-ESWT reduced prostatic inflammation

The EAP model showed strong inflammatory infiltration in prostate tissue, including increased, such as

• CD3+ T cells
• CD68+ macrophages
• IL-6
• CCL2
• CCL3

RSL3 worsened inflammation, while DFO reduced it. Li-ESWT significantly decreased inflammatory lesions and immune cell infiltration. This supports the idea that ferroptosis contributes to chronic prostatic inflammation and that Li-ESWT has anti-inflammatory effects partly by suppressing ferroptosis.

2. Li-ESWT reduced fibrosis

EAP rats showed increased stromal collagen deposition and fibrosis. This was associated with epithelial-mesenchymal transition, shown by:

• Decreased E-cadherin
• Increased N-cadherin
• Increased α-SMA-positive smooth muscle thickening

Li-ESWT reversed these changes and reduced collagen accumulation. DFO had similar anti-fibrotic effects, while RSL3 aggravated fibrosis. This suggests that ferroptosis may contribute to prostate fibrosis in CP/CPPS-like disease.

3. Li-ESWT alleviated pelvic pain and mast cell activation

EAP rats had increased pelvic mechanical hypersensitivity, measured using von Frey filaments. RSL3 worsened pain responses. Li-ESWT reduced hyperalgesia and also inhibited mast cell activation, shown by reduced:

• Total mast cell number
• Degranulated mast cells
• TPSB2-positive cells

Because mast cells can release tryptase and histamine, which contribute to pain sensitization, this finding links Li-ESWT to reduced neuroimmune pain signaling.

4. Li-ESWT restored antioxidant capacity

EAP prostates showed increased oxidative damage, including:

• Increased ROS
• Increased MDA
• Reduced GSH
• Reduced SOD activity

Li-ESWT reduced ROS and MDA while increasing GSH and SOD activity. This indicates that Li-ESWT strengthens antioxidant defense in inflamed prostate tissue.

5. Li-ESWT inhibited ferroptosis

Ferroptosis was demonstrated by increased:

• Ferrous iron
• Lipid peroxidation
• ACSL4
• LPCAT3
• ALOX15
• PTGS2/COX-2

Li-ESWT reduced iron accumulation and lipid peroxidation markers. It also lowered PTGS2/COX-2 expression, supporting an anti-ferroptotic effect. The ferroptosis inhibitor DFO produced similar protective effects, while RSL3 worsened disease features.

Proposed Mechanism

The central mechanism proposed is: Li-ESWT activates Integrin-β1, which restores NRF2 signaling. NRF2 then upregulates xCT and GPX4, improving antioxidant defense and suppressing ferroptosis. More simply (Fig. 9):

• Li-ESWT delivers mechanical stimulation to prostate tissue.
• This mechanical signal is sensed by Integrin-β1.
• Integrin-β1 activation increases NRF2, a master antioxidant transcription factor.
• NRF2 upregulates xCT and GPX4.
• xCT supports glutathione synthesis.
• GPX4 detoxifies lipid peroxides.
• Lipid peroxidation and iron-driven ferroptosis are reduced.
• Inflammation, fibrosis, mast cell activation, and pain are alleviated.

Cell Experiment Evidence

In RWPE-1 cells, LPS caused inflammatory stress and reduced:

• NRF2
• xCT
• GPX4

Li-ESWT restored these proteins and reduced lipid ROS and ferrous iron accumulation. However, when Integrin-β1 was knocked down, Li-ESWT could no longer restore NRF2, xCT, or GPX4 effectively. This suggests that Integrin-β1 is required for Li-ESWT’s anti-ferroptotic effect. When NRF2 was knocked down, Li-ESWT also lost much of its ability to increase xCT and GPX4. But overexpressing xCT and GPX4 rescued the anti-ferroptotic effect. This supports the pathway (Fig. 9):

Integrin-β1 → NRF2 → xCT/GPX4

Conclusion

The study concludes that Li-ESWT alleviates chronic prostatitis-like pathology by inhibiting ferroptosis. It does this through a mechanotransduction pathway involving Integrin-β1-mediated activation of NRF2, which then upregulates the anti-ferroptotic defense system xCT/GPX4.

As a result, Li-ESWT reduces:

• Iron overload
• Lipid peroxidation
• Oxidative stress
• Inflammation
• Fibrosis
• Mast cell activation
• Pelvic pain

Discussion

This study is important because it provides a possible molecular explanation for why Li-ESWT improves CP/CPPS symptoms. Clinically, Li-ESWT is already being explored as a non-invasive treatment for CP/CPPS, but its mechanism has not been fully understood. This article suggests that its benefit may come from blocking the inflammation-ferroptosis cycle in prostate tissue. The study also positions ferroptosis as a potential therapeutic target in CP/CPPS.

Limitations

The authors acknowledge several limitations:

• The precise signaling link between Integrin-β1 and NRF2 remains unclear.
• The detailed transcriptional regulation of xCT and GPX4 by NRF2 was not fully mapped.
• Findings are based on animal and cell models, not human CP/CPPS samples.
• More clinical evidence is needed to confirm whether Li-ESWT modulates ferroptosis markers in patients.

One-Sentence Takeaway

Li-ESWT may treat CP/CPPS by activating Integrin-β1-dependent NRF2 signaling, restoring xCT/GPX4 antioxidant defenses, suppressing ferroptosis, and thereby reducing prostate inflammation, fibrosis, and pain.

Jens Rassweiler