Protein and m-RNA expression of farnesyl-transferases, RhoA and RhoB in rat liver hepatocytes: action of perillyl alcohol and vitamin A in vivo

The immune and metabolic treatment approach of using testosterone on mice models of liver injury

Background: Natural killer (NK) cells showed an anti-fibrotic effect; however, their function is thought to be impaired in advanced liver injury. In the current study, we aimed to assess the immune and metabolic impact of testosterone on mice models of liver injury. Methods: Carbon-tetrachloride induced liver fibrosis male mice models was i.p injected for 2 weeks (acute) and 4 weeks (chronic) (n = 36). Testosterone (4 mg/kg mouse body weight) was injected i.p. following the first week of the acute model of CCl4 and following the second week of the chronic model of CCl4. At the end of the experiments, mice were sacrificed, and serum was collected for assessing liver enzymes of ALT and AST, as well as inflammatory markers of IL-6, metabolic makers of C-peptide levels, and lipid and glucose profiles. Livers were harvested and used for histological assessments for inflammation and fibrosis. Fibrosis profiles from liver extracts, αSMA and Collagen III, were assessed by RT-PCR. Moreover, liver tissue-resident NK cells were isolated and evaluated for their activity by assessing INF-γ and IL-6 receptors using ELISA and flow cytometry, respectively. Results: Serum ALT, AST, and IL-6, as well as metabolic assessments of cholesterol, triglyceride, C-peptide, fasting blood sugar, and fibrotic profiles, were linearly correlated with disease progressions. Histological characterization of the liver was worsened in the chronic model of liver injury. Testosterone-treated mice exhibit a significant reduction in collagen depositions with less dense fibrosis tissue associated with reduced liver injury enzymes and metabolic markers in both the acute and chronic CCl4 mice models in favor of the latter one (p < 0.05). Moreover, testosterone treatments displayed a significant decrease in serum IL-6 of 2.4-fold (p = 0.0001) and 2.3-fold (p = 0.0003) in the acute and chronic models, respectively (p = 0.002), and data showed an increase in INF-γ release from NK associated with a reduction in their IL-6 receptor expressions (p < 0.05). Conclusion: Our results indicated effects of testosterone on mediating a decreased expressions of NK IL-6 receptors and consequently inducing their activation; which in part, could explain the amelioration of liver injury. Our data suggest an anti-inflammatory and anti-fibrotic treatment approach of using testosterone for delaying disease progressions.

Ecballium elaterium improved stimulatory effects of tissue-resident NK cells and ameliorated liver fibrosis in a thioacetamide mice model

Ecballium elaterium (EE), widely used plant in Mediterranean medicine, showed anticancer activity. This study aimed to investigate EE effects on liver fibrosis in an animal model of thioacetamide (TAA). Intraperitoneal administration of TAA was performed twice weekly for four weeks in C57BL6J mice. Livers were extracted and serum were evaluated for inflammatory markers (H&E staining, ALT, AST, ALP), pro-inflammatory cytokines, fibrosis (Sirius red staining, Masson's trichrome, α-smooth muscle actin and collagen III), and metabolic (cholesterol, triglyceride, C-peptide, and fasting-blood-sugar) profiles. Glutathione, glutathione peroxidase, and catalase liver antioxidant markers were assessed. Tissue-resident NK cells from mice livers were functionally assessed for activating receptors and cytotoxicity. Compared to vehicle-treated mice, the TAA-induced liver injury showed attenuation in the histopathology outcome following EE treatment. In addition, EE-treated mice resulted in decreased serum levels of ALT, AST, and ALP, associated with a decrease in IL-20, TGF-β, IL-17, IL-22 and MCP-1 concentrations. Moreover, EE-treated mice exhibited improved lipid profile of cholesterol, triglycerides, C-peptide, and FBS. EE treatment maintained GSH, GPX, and CAT liver antioxidant activity and led to elevated counts of tissue-resident NK (trNK) cells in the TAA-mice. Consequently, trNK demonstrated an increase in CD107a and IFN-γ with improved potentials to kill activated hepatic-stellate cells in an in vitro assay. EE exhibited antifibrotic and antioxidative effects, increased the number of trNK cells, and improved metabolic outcomes. This plant extract could be a targeted therapy for patients with advanced liver injury.

Intranasal Perillyl Alcohol for Glioma Therapy: Molecular Mechanisms and Clinical Development

Intracranial malignancies, such as primary brain cancers and brain-localized metastases derived from peripheral cancers, are particularly difficult to treat with therapeutic agents, because the blood-brain barrier (BBB) effectively minimizes brain entry of the vast majority of agents arriving from the systemic circulation. Intranasal administration of cancer drugs has the potential to reach the brain via direct nose-to-brain transport, thereby circumventing the obstacle posed by the BBB. However, in the field of cancer therapy, there is a paucity of studies reporting positive results with this type of approach. A remarkable exception is the natural compound perillyl alcohol (POH). Its potent anticancer activity was convincingly established in preclinical studies, but it nonetheless failed in subsequent clinical trials, where it was given orally and displayed hard-to-tolerate gastrointestinal side effects. Intriguingly, when switched to intranasal delivery, POH yielded highly promising activity in recurrent glioma patients and was well tolerated. As of 2018, POH is the only intranasally delivered compound in the field of cancer therapy (outside of cancer pain) that has advanced to active clinical trials. In the following, we will introduce this compound, summarize its molecular mechanisms of action, and present the latest data on its clinical evaluation as an intranasally administered agent for glioma.

Inhibition of perillyl alcohol on cell invasion and migration depends on the Notch signaling pathway in hepatoma cells

Cell metastasis, especially the process of invasion and migration, is considered as the main cause for the high mortality rate of hepatocellular carcinoma (HCC), which has become the sixth most common cancer worldwide and the third leading cause of cancer death. In this present study, we aimed to exploit the effects of perillyl alcohol on cell invasion and migration and the underlying molecular mechanisms in HCC. According to the transwell assays, cell invasiveness and migratory capacity were markedly higher in hepatoma cells (HepG2, SMMC-7721 and MHCC97H) than those in normal liver cells (HL-7702), and then significantly suppressed by perillyl alcohol treatment (P < 0.05). Meanwhile, the mRNA levels of Notch signaling pathway downstream target genes, HES1, HES5, and HEY1, were notably higher in hepatoma cells detected with real-time reverse transcription polymerase chain reaction (RT-PCR) (P < 0.05). After treated with perillyl alcohol, these mRNA levels were significantly decreased in hepatoma cells (P < 0.05). In addition, compared with the normal liver cells, the protein expression levels of Notch1 intracellular domain (N1ICD) and Snail were significantly increased, while E-cadherin protein expression was significantly decreased in hepatoma cells (P < 0.05). However, perillyl alcohol treatment significantly decreased N1ICD and Snail protein expressions and increased E-cadherin protein expression in hepatoma cells (P < 0.05). In conclusion, perillyl alcohol might play an important role in the process of hepatoma cell invasion and migration via decreasing the activity of Notch signaling pathway and increasing E-cadherin expression regulated by Snail.

Perillyl alcohol suppresses antigen-induced immune responses in the lung

Perillyl alcohol (POH) is an isoprenoid which inhibits farnesyl transferase and geranylgeranyl transferase, key enzymes that induce conformational and functional changes in small G proteins to conduct signal production for cell proliferation. Thus, it has been tried for the treatment of cancers. However, although it affects the proliferation of immunocytes, its influence on immune responses has been examined in only a few studies. Notably, its effect on antigen-induced immune responses has not been studied. In this study, we examined whether POH suppresses Ag-induced immune responses with a mouse model of allergic airway inflammation. POH treatment of sensitized mice suppressed proliferation and cytokine production in Ag-stimulated spleen cells or CD4(+) T cells. Further, sensitized mice received aerosolized OVA to induce allergic airway inflammation, and some mice received POH treatment. POH significantly suppressed indicators of allergic airway inflammation such as airway eosinophilia. Cytokine production in thoracic lymph nodes was also significantly suppressed. These results demonstrate that POH suppresses antigen-induced immune responses in the lung. Considering that it exists naturally, POH could be a novel preventive or therapeutic option for immunologic lung disorders such as asthma with minimal side effects.

Protein isoprenylation regulates secretion of matrix metalloproteinase 1 from rheumatoid synovial fibroblasts: Effects of statins and farnesyl and geranylgeranyl transferase inhibitors

OBJECTIVE

To determine whether protein prenylation (farnesyl/geranylgeranylation) regulates matrix metalloproteinase (MMP) secretion from rheumatoid arthritis (RA) synovial fibroblasts (RASFs), and whether MMP-1 secretion can be regulated by statins or prenyltransferase inhibitors via effects mediated by ERK, JNK, and NF-kappaB.

METHODS

RASFs obtained from patients during elective knee replacement surgery were assessed by immunoblotting and/or enzyme-linked immunosorbent assay for secretion of MMP-1 and MMP-13 in the presence of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), statins, the farnesyl transferase (FT) inhibitor FTI-276 and geranylgeranyl transferase inhibitor GGTI-298, and prenyl substrates (farnesyl pyrophosphate [FPP] and geranylgeranyl pyrophosphate [GGPP]). Activities of JNK and ERK were determined by phosphoimmunoblotting, and NF-kappaB activation was determined by nuclear translocation of the p65 component.

RESULTS

FTI-276, but not statins, inhibited RASF secretion of MMP-1, but not MMP-13, following induction with TNFalpha (P = 0.0007) or IL-1beta (P = 0.006). Loading RASFs with FPP to promote farnesylation enhanced MMP-1 secretion. FTI-276 inhibited activation of JNK (P < 0.05) and NF-kappaB (P = 0.02), but not ERK. In contrast, GGTI-298 enhanced, while GGPP inhibited, MMP-1 secretion. FTI-276 and GGTI-298 together had no effect on MMP-1 secretion. Stimulation of RASFs with TNFalpha or IL-1beta led to increased expression and activity of FT.

CONCLUSION

Protein farnesylation is required for expression and secretion of MMP-1 from RASFs, via effects on JNK and NF-kappaB. The ability of cytokines to stimulate the expression and activity of FT suggests that FT may be increased in the rheumatoid joint. In contrast, geranylgeranylation down-regulates MMP-1 expression. Statins simultaneously inhibit farnesylation and geranylgeranylation, and in consequence do not inhibit MMP-1 secretion. The ability of FTI-276 to inhibit MMP-1 secretion suggests a potential therapeutic strategy in RA.