Limonin relieves TGF-ß-induced hepatocyte EMT and hepatic stellate cell activation in vitro and CCl4-induced liver fibrosis in mice via upregulating Smad7 and subsequent suppression of TGF-ß/Smad cascade.

Liver fibrosis is a pathological process as a result of intrahepatic deposition of excessive ECM. EMT of hepatocytes and activation of HSCs both play important roles in the etiology of liver fibrosis. Here, we found that limonin repressed TGF-ß-induced EMT in AML-12 hepatocytes and activation of LX-2 HSCs. Limonin suppressed TGF-ß-provoked Smad2/3 C-terminal phosphorylation and subsequent nuclear translocation. However, limonin exerted few effects on Smad2/3 phosphorylation atlinker region. Mechanistically, limonin increased Smad7 in both AML-12 and LX-2 cells. Knockdown of Smad7 abrogated inhibitory effects of limonin on TGF-ß-induced changes in both two cells. Further studies revealed that limonin upregulated Smad7 and declined C-terminal phosphorylation and nuclear translocation of Smad2/3 to alleviate mouse CCl4-induced liver fibrosis. Our findings indicated that limonin inhibits TGF-ß-induced EMT of hepatocytes and activation of HSCs in vitro and CCl4-induced liver fibrosis in mice. Upregulated Smad7 which suppresses Smad2/3-dependent gene transcription is implicated in the hepatoprotective activity of limonin.

Piperine inhibits AML-12 hepatocyte EMT and LX-2 HSC activation and alleviates mouse liver fibrosis provoked by CCl4: roles in the activation of the Nrf2 cascade and subsequent suppression of the TGF-ß1/Smad axis.

Piperine (PIP) is an alkaloid derived from peppercorns. Herein, we assessed its effects on hepatocyte EMT and HSC activation in vitro and CCl4-elicited liver fibrosis in mice. Further experiments were performed to unveil the molecular mechanisms underlying the hepatoprotective activity of PIP. We found that PIP inhibited TGF-ß1-provoked AML-12 hepatocyte EMT and LX-2 HSC activation. Mechanistically, in AML-12 and LX-2 cells, PIP evoked Nrf2 nuclear translocation and increased transcriptions of Nrf2-responsive antioxidative genes. These events decreased TGF-ß1-induced production of ROS. Moreover, PIP increased the expression of Smad7, suppressed phosphorylation and nuclear translocation of Smad2/3, and decreased the transcriptions of Smad2/3-downstream genes. Knockdown of Nrf2 abrogated the protective activity of PIP against TGF-ß1. Modulatory effects of PIP on the TGF-ß1/Smad cascade were also crippled, which suggested that activation of Nrf2 played critical roles in the regulatory effects of PIP on TGF-ß1/Smad signaling. Experiments in vivo unveiled that PIP ameliorated mouse liver fibrosis provoked by CCl4. PIP modulated the intrahepatic contents of the markers of EMT and HSC activation. In mouse livers, PIP activated Nrf2 signaling and reduced Smad2/3-dependent gene transcriptions. Our findings collectively suggested PIP as a new chemical entity with the capacity of alleviating liver fibrosis. The activation of the Nrf2 cascade and subsequent suppression of the TGF-ß1/Smad axis are implicated in the hepatoprotective activity of PIP.

A characterized saponin extract of Panax japonicus suppresses hepatocyte EMT and HSC activation in vitro and CCl4-provoked liver fibrosis in mice: Roles of its modulatory effects on the Akt/GSK3ß/Nrf2 cascade.

BACKGROUND AND PURPOSE: Liver fibrosis constitutes a pathologic condition resulting in a series of advanced liver diseases. Oleanane-type saponins are distinctive active constituents in the medicinal plant Panax japonicus C. A. Mey (P. japonicus). Herein, we assessed protective effects of a characterized saponin extract of rhizomes of P. japonicus (SEPJ) on hepatocyte EMT and HSC activation in vitro and liver fibrosis in mice. We also investigated molecular mechanisms underlying the hepatoprotective activity of SEPJ. METHODS: EMT of AML-12 hepatocytes was evaluated by observing morphology of cells and quantifying EMT marker proteins. Activation of LX-2 HSCs was assessed via scratch assay, transwell assay, and EdU-incorporation assay, and by quantifying activation marker proteins. Liver fibrosis in mice was evaluated by HE, SR, and Masson staining, and by measuring related serum indicators. Immunoblotting and RT-PCR were performed to study mechanisms underlying the action of SEPJ. RESULTS: SEPJ inhibited TGF-ß-induced EMT in AML-12 hepatocytes and activation of LX-2 HSCs. SEPJ elevated Akt phosphorylation at Ser473 and GSK3ß phosphorylation at Ser9 in these cells, giving rise to a descent of the catalytic activity of GSK3ß. These events increased levels of both total and nuclear Nrf2 protein and upregulated expressions of Nrf2-responsive antioxidative genes. In addition, enhanced phosphorylation of Akt and GSK3ß acted upstream of SEPJ-mediated activation of Nrf2. Knockdown of Nrf2 or inhibition of Akt diminished the protective activity of SEPJ against TGF-ß in both AML-12 and LX-2 cells. Our further in vivo experiments revealed that SEPJ imposed a considerable alleviation on CCl4-provoked mouse liver fibrosis. Moreover, hepatic Akt/GSK3ß/Nrf2 cascade were potentiated by SEPJ. Taken together, our results unveiled that SEPJ exerted protective effects against fibrogenic cytokine TGF-ß in vitro and ameliorated liver fibrosis in mice. Mechanistically, SEPJ regulated the Akt/GSK3ß/Nrf2 signaling which subsequently enhanced intracellular antioxidative capacity. CONCLUSIONS: SEPJ inhibits hepatocyte EMT and HSC activation in vitro and alleviates liver fibrosis in mice. Modulation of the Akt/GSK3ß/Nrf2 cascade attributes to its hepatoprotective effects. Our findings support a possible application of SEPJ in the control of liver fibrosis.

Comparision of the Limberg flap with the V-Y flap technique in the treatment of pilonidal disease / 대한외과학회지

PURPOSE: In this study, we investigated whether there is a factor that can aid determi nation of the preferred technique by comparing the early and late results of two different surgical techniques for the treatment of pilonidal sinus. METHODS: The medical records of 176 patients in whom the Limberg flap (LF) or V-Y flap techniques were applied for reconstruction after the excision were evaluated retrospectively. RESULTS: The development rates of postoperative hematoma, wound separation, wound infection, and seroma were 2.8%, 5.1%, 5.6%, and 6.3%, respectively, while total flap necrosis was not observed in any patient. Return to daily activities was achieved after a mean of 17.1 days (13 to 21 days) days in the LF group and 32.7 days (18 to 47 days) in the V-Y flap group. During the average follow-up of 65 months (36 to 110 months), nine patients (5.1%) developed recurrent disease. There was no difference between the two groups with respect to early surgical complications (P = 0.286) or disease recurrence (P = 0.094), whereas the resumption of daily activities was longer in patients with a V-Y flap (P < 0.001). CONCLUSION: The early postoperative and long-term results of the LF and V-Y flap techniques for the treatment of pilonidal sinus were similar. Because the resumption of daily activities at work is achieved later in patients undergoing the V-Y flap compared with the LF technique, patients' employment (or position in working life) must be considered when determining the most appropriate surgical technique.