Angiotensin II and tumor necrosis factor-α stimulate the growth, migration and invasion of BEL-7402 cells via down-regulation of GRK2 expression.

PURPOSE: To investigate the effects of angiotensin II (Ang II) and tumor necrosis factor-α (TNF-α) on the biological characteristics of hepatocellular carcinoma (HCC) cells and the associated changes in G protein-coupled receptor kinase 2 (GRK2) expression. METHODS: The mean serum levels of Ang II and TNF-α in normal subjects and patients with benign liver tumors (BLTs) and HCC were evaluated by enzyme-linked immunosorbent assay (ELISA), and liver samples from the patients with HCC and HCC mice were used to assess the protein levels of both cytokines, their major receptors and GRK2. In addition, the dynamics of Bel-7402 cells were determined with cell counting kit-8 (CCK-8) and Transwell experiments, while the levels of the primary cytokine receptors Ang II type-1 receptor (AT1R) and type-2 receptor (AT2R) as well as TNF receptor 1 (TNFR1) were detected by flow cytometry (FCM). The effects of Ang II and TNF-α on the GRK2 levels in Bel-7402 cells and on the dynamics of GRK2-knockdown HCC cells were also investigated. RESULTS: Both cytokines independently enhanced Bel-7402 cell growth, migration and invasion by decreasing the GRK2 level. In contrast, down-regulating the GRK2 level in Bel-7402 cells suppressed these effects. No synergistic effects were discovered when Ang II and TNF-α were administered together. Furthermore, increased AT1R and TNFR1 levels stimulated HCC initiation and progression, whereas AT2R overexpression produced the opposite effect. CONCLUSIONS: The present results suggested that Ang II and TNF-α promote Bel-7402 cell growth, migration and invasion by down-regulating GRK2 expression, and that the associated receptors AT1R, AT2R and TNFR1 participate in HCC initiation and progression.

The influence of TNF-α and Ang II on the proliferation, migration and invasion of HepG2 cells by regulating the expression of GRK2.

PURPOSE: Hepatocellular carcinoma (HCC) is a common digestive system malignancy that is associated with a poor prognosis. This study researched the interaction of tumor necrosis factor-α (TNF-α) and angiotensin II (Ang II) in HCC cells proliferation, migration and invasion and examined their influence on the expression of G protein-coupled receptor kinase 2 (GRK2) and relevant receptors. METHODS: Cell Counting Kit-8 and Transwell assays were performed to evaluate the effects of TNF-α and Ang II on HepG2 cells proliferation, migration and invasion. Flow cytometry was used to investigate the expression of tumor necrosis factor receptor 1 (TNFR1), angiotensin II type 1 (AT1R) and type 2 receptors (AT2R) on the surface of HepG2 cells. Additionally, Western blot was performed to assess the modulation of GRK2 expression by TNF-α and Ang II in HepG2 cells. Meanwhile, GRK2 siRNA-transfected HepG2 cells were used to confirm the effects of GRK2, TNF-α and Ang II on the proliferation, migration and invasion of GRK2-knockdown HCC cells. Finally, the expression of TNF-α, Ang II, TNFR1, AT1R, AT2R and GRK2 proteins in HCC, tumor-adjacent and normal liver tissues were tested by immunohistochemistry. RESULTS: The data demonstrated that TNF-α and Ang II can enhance the proliferation, migration and invasion of HepG2 cells through suppressing GRK2 expression but that the two reagents combined did not have synergistic effects. Moreover,overexpression of TNFR1 and AT1R perhaps promoted the formation and progression of HCC, while high AT2R expression had the opposite effect. CONCLUSIONS: This study provides new ideas for the prevention and treatment of HCC by researching the interaction and probable mechanism of different bioactive factors associated with HCC.

IL-21 acts as a promising therapeutic target in systemic lupus erythematosus by regulating plasma cell differentiation.

Plasma cells, which secrete auto-antibodies, are considered to be the arch-criminal of autoimmune diseases such as systemic lupus erythematosus, but there are many cytokines involved in inducing the differentiation of B-cell subsets into plasma cells. Here, we emphasize IL-21, which has emerged as the most potent inducer of plasma cell differentiation. In this review, we focused on the promoting effects of IL-21 on plasma cell differentiation and discuss how these effects contribute to B cell-mediated autoimmune disease.

[Pulmonary immune responses to acute lung injury following smoke inhalation and its mechanisms].

OBJECTIVE: To analyze pulmonary innate and specific immune responses following the smoke inhalation-induced acute lung injury (ALI). METHODS: Smoke inhalation-induced ALI should be replicated at high (4x10(-3)) and low (2x10(-3)) dose of carbon monoxide (CO) respectively for 24 hours. After this period, lung tissue histopathological changes and the parameters of both treatment groups were observed compared to those of control animals: the phasic variations of concentrations of pro-anti-inflammatory cytokines in bronchoalveolar lavage fluid (BALF), numbers of lymphocyte subsets in peripheral blood and BALF, CD45(+) lymphoid leukocytes, CD45(+) nonlymphoid leukocytes and CD4(+)/CD8(+) in BALF were determined by flow cytometry (FCM). RESULTS: Lung histopathological changes of smoke-exposed animals revealed obvious alveolar leakage characterizing ALI. Concentrations of tumor necrosis factor-alpha (TNF-alpha) in BALF were increased immediately after injury and reached the peak at 2 hours after injury, and more obvious changes were seen in high dose group than those in low dose group. Levels of interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) were elevated following after 4 hours injury peaking at 12 hours. The changes of levels of IL-6 in low dose group were more obviously than those in high dose group, and those of IFN-gamma were reverse. Levels of IL-6 and IFN-gamma were decreased at 24 hours, still higher than those of control group (P<0.05 or P<0.01), whereas the expressions of IL-10 were increased at 6 hours, and continuing upregulation to 24 hours compared with those of control group (P<0.05 or P<0.01). Additionally, the numbers of lung-resident CD4(+) T cells, CD8(+) T cells, natural killer cells, B cells and total T-lymphocytes in peripheral blood and BALF were significantly reduced after challenge (P<0.05 or P<0.01). The number of CD45(+) lymphoid leukocytes in BALF and CD4(+)/CD8(+) were decreased; while that of CD45(+) nonlymphoid leukocytes was increased obviously compared with those of control group, and obviously changed in high dose group than in low dose group (P<0.05 or P<0.01). CONCLUSION: These data suggest that smoke inhalation induced ALI is associated with exaggerated and sustained pulmonary innate immune responses partly by activated polymorphonuclear neutrophils (PMN) and macrophage, whereas specific immunity in the lung is suppressed obviously.