homoharringtonine and Fibrosis

The prevention of surgery-induced intraarticular fibrosis remains a challenge following orthopedic surgery. Homoharringtonine (HHT) has been reported to have positive effects in preventing various kinds of fibrosis. However, little is known regarding its effect as well as the potential mechanism of HHT in preventing surgery-induced intraarticular fibrosis.. Various concentrations of HHTs were locally applied in vivo to reduce knee intraarticular fibrosis in rabbits. Histological macroscopic assessments such as hematoxylin and eosin (HE) staining, Masson's trichrome staining, and Picric-sirius red polarized light were used to evaluate the effect of HHT in reducing intraarticular fibrosis. CCK-8, cell cycle assay, and EdU incorporation assay were used in vitro to detect HHT's effect on inhibiting fibroblast viability and proliferation. The effect of HHT on fibroblast differentiation, extracellular matrix production, and apoptosis were evaluated by western blot, flow cytometry, immunofluorescent staining, and TUNEL analysis. Moreover, the expressions of PI3K/AKT/mTOR signaling pathway were detected.. The results demonstrated that HHT could reduce the formation of intraarticular fibrosis. HHT was also found to induce fibroblast apoptotic cell death in a dose- and time-dependent manner in vitro. Moreover, HHT could effectively inhibit the production of the extracellular matrix secreted by fibroblasts and inhibited the expression of p-PI3K, p-AKT, and p-mTOR in a dose-dependent manner. After treating with insulin-like growth factor-1 (IGF-1), an activator of the PI3K/AKT axis, the expressions of pro-apoptosis-related proteins were decreased, and the fibroblast apoptosis rate was also inhibited.. In conclusion, this study demonstrated that HHT could reduce the formation of intraarticular fibrosis through the inhibition of fibroblast proliferation, extracellular matrix production, and the induction of fibroblast apoptotic cell death. Furthermore, its potential mechanism may be through the suppression of the PI3K/AKT/mTOR signaling pathway.

Topics: Apoptosis; Cell Line; Cell Proliferation; Depression, Chemical; Extracellular Matrix; Fibroblasts; Fibrosis; Homoharringtonine; Humans; Knee Joint; Phosphatidylinositol 3-Kinases; Postoperative Complications; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases

Surgery-induced epidural fibrosis after laminectomy often results in poor clinical outcomes. Fibroblasts proliferation is considered to be one of the major causes of epidural fibrosis formation. Previously, there was no research about the effect of Homoharringtonine(HHT) on inhibiting fibroblast proliferation and reducing epidural fibrosis. Here, we performed in vitro and in vivo experiments to explore the effect of HHT on inhibiting fibroblast proliferation, inducing fibroblast apoptosis and preventing epidural fibrosis formation. In vitro, the effect of HHT on inhibiting fibroblasts was detected by CCK-8 assay. Besides, the effect of HHT on causing fibroblast apoptosis was investigated via Western blots, flow cytometry and TUNEL assay. Results suggested that HHT could inhibit fibroblasts proliferation and induce apoptosis. And the marker proteins of endoplasmic reticulum (ER) stress were also changed positively. In vivo, histological macroscopic assessment, hydroxyproline content analysis and histological staining were used to detect the effect of HHT on reducing epidural fibrosis. The results showed that HHT had positive suppressive effects on epidural fibrosis following laminectomy in rats. TUNEL assay in epidural tissue suggested that HHT could obviously induce fibroblasts apoptosis. Immunohistochemistry staining showed that the expression of two important ER stress markers(78-kDa glucose-regulated protein and C/EBP homologous protein) were also increased. In conclusion, this research showed that HHT could reduce epidural fibrosis formation after laminectomy, and the potential mechanism might through inhibiting fibroblasts proliferation and inducing fibroblasts apoptosis via ER stress signaling pathway. It might provide a novel agent for reducing epidural fibrosis after laminectomy surgery.

Topics: Animals; Apoptosis; Cell Proliferation; Collagen; Endoplasmic Reticulum Stress; Epidural Space; Fibroblasts; Fibrosis; Harringtonines; Homoharringtonine; Rats; Signal Transduction

Rabbit models of intraocular proliferation were made by intravitreal injection of cultured homologous conjunctival fibroblasts. 0.025 mg of homoharringtonine, a Chinese herbal drug that potently inhibited rabbit fibroblast proliferation in vitro, or distilled water, as control, was injected into the vitreous immediately after the cell transplantation. On days 1, 3, 7, 10 after the injection, the homoharringtonine eyes were given same doses of the agent subconjunctivally. After 21 days, these eyes developed significantly less intravitreal proliferation than the control eyes, and no retinal detachment occurred while 54.5% of the control eyes did. Light microscopy and TEM revealed no toxic effect on tissues in the medicated eyes. Hence, homoharringtonine may be of clinical value in the treatment of post-traumatic proliferation in the eye.

Topics: Alkaloids; Animals; Cells, Cultured; Eye Diseases; Eye Injuries; Female; Fibrosis; Harringtonines; Homoharringtonine; Male; Rabbits; Retina; Retinal Detachment; Vitreous Body