Rolipram plays an anti-fibrotic effect in ligamentum flavum fibroblasts by inhibiting the activation of ERK1/2

Abstract

Background Fibrosis is an important factor and process of ligamentum flavum hypertrophy. The expression of phosphodiesterase family (PDE) is related to inflammation and fibrosis. This article studied the expression of PDE in hypertrophic ligamentum flavum fibroblasts and investigated whether inhibition of PDE4 activity can play an anti-fibrotic effect. Methods Samples of clinical hypertrophic ligamentum flavum were collected and patients with lumbar disc herniations as a control group. The collagenase digestion method is used to separate fibroblasts. qPCR is used to detect the expression of PDE subtypes, type I collagen (Col I), type III collagen (Col III), fibronectin (FN1) and transforming growth factor β1 (TGF-β1). Recombinant TGF-β1 was used to stimulate fibroblasts to make a fibrotic cell model and treated with Rolipram. The morphology of the cells treated with drugs was observed by Sirius Red staining. Scratch the cells to observe their migration and proliferation. WB detects the expression of the above-mentioned multiple fibrotic proteins after drug treatment. Finally, combined with a variety of signaling pathway drugs, the signaling mechanism was studied. Results Multiple PDE subtypes were expressed in ligamentum flavum fibroblasts. The expression of PDE4A and 4B was significantly up-regulated in the hypertrophic group. Using Rolipram to inhibit PDE4 activity, the expression of Col I and TGF-β1 in the hypertrophic group was inhibited. Col I recovered to the level of the control group. TGF-β1 was significantly inhibited, which was lower than the control group. Recombinant TGF-β1 stimulated fibroblasts to increase the expression of Col I/III, FN1 and TGF-β1, which was blocked by Rolipram. Rolipram restored the increased expression of p-ERK1/2 stimulated by TGF-β1. Conclusion The expressions of PDE4A and 4B in the hypertrophic ligamentum flavum are increased, suggesting that it is related to the hypertrophy of the ligamentum flavum. Rolipram has a good anti-fibrosis effect after inhibiting the activity of PDE4. This is related to blocking the function of TGF-β1, specifically by restoring normal ERK1/2 signal.

Revealing the novel autophagy-related genes for ligamentum flavum hypertrophy in patients and mice model

“…It has been reported that cigarette smoke-inactivated SIRT1 promotes autophagy-dependent senescence of AT2 cells to induce pulmonary fibrosis ( 48 ). Besides FN1 , TGFβ1 has been shown to play an important role in LFH ( 42 , 49 ), however, the mechanisms underlying the remainder of the hub ARGs (NGF, HMOX1 , CAT , and SIRT1 ) in the occurrence and development of LFH have not been fully elucidated. Further study is necessary to discover their potential biological function.…”

Nonsurgical therapy for lumbar spinal stenosis caused by ligamentum flavum hypertrophy: A review

“…The use of rolipram, an inhibitor of PDE4, not only significantly inhibited PDE4 activity but also suppressed the expression of Col I/ III, fibronectin, and TGF-β1, indicating that rolipram may exert an antifibrotic effect in LFH by inhibiting PDE4 activity. [73] Rolipram attenuates fibroblast activity and suppresses proliferation and differentiation. [74] Additionally, it has neuroprotective properties and may exert antiallodynic effects.…”

“…TGF-β1 is an essential molecule leading to LF fibrosis, and TGF-β1 exerts its fibrosis-stimulating effects via the Smad2/3, PI3K/Akt, β-catenin, and ERK1/2 signaling pathways. [2,30,73] It is feasible to inhibit LF fibrosis by modulating the concentration and potency of TGF-β1 in the serum and LF tissues. Previous studies have shown that bone morphogenetic protein-7 (BMP-7) interferes with TGF-β1 signaling and expression of various matrix proteins, thereby inhibiting ECM remodeling.…”

Amelioration of ligamentum flavum hypertrophy using umbilical cord mesenchymal stromal cell-derived extracellular vesicles

“…Previous studies have found markedly upregulated TGF-β1 expression levels in the hypertrophied LF of LSS patients [ 11 , 12 ]. The increased synthesis of extracellular matrix (ECM) proteins after stimulation by TGF-β1 expression in LF cells [ 13 ] was observed, elucidating that the formation and accumulation of inflammatory cytokines are important pathological mechanisms of LF fibrosis.…”