Proteomic Analysis of the Effects of Tetramethylpyrazine on Irradiated QXMSC1 Cells

Tetramethylpyrazine: A review on its mechanisms and functions

Ligusticum chuanxiong Hort (known as Chuanxiong in China, CX) is one of the most widely used and long-standing medicinal herbs in China. Tetramethylpyrazine (TMP) is an alkaloid and one of the active components of CX. Over the past few decades, TMP has been proven to possess several pharmacological properties. It has been used to treat a variety of diseases with excellent therapeutic effects. Here, the pharmacological characteristics and molecular mechanism of TMP in recent years are reviewed, with an emphasis on the signal-regulation mechanism of TMP. This review shows that TMP has many physiological functions, including anti-oxidant, anti-inflammatory, and anti-apoptosis properties; autophagy regulation; vasodilation; angiogenesis regulation; mitochondrial damage suppression; endothelial protection; reduction of proliferation and migration of vascular smooth muscle cells; and neuroprotection. At present, TMP is used in treating cardiovascular, nervous, and digestive system conditions, cancer, and other conditions and has achieved good curative effects. The therapeutic mechanism of TMP involves multiple targets, multiple pathways, and bidirectional regulation. TMP is, thus, a promising drug with great research potential.

Serum translationally controlled tumor protein is involved in rat liver regeneration after hepatectomy

AIM

The translationally controlled tumor protein (TCTP) has been reported to promote progression of many physiological processes. However, whether TCTP is involved in liver regeneration has been rarely studied. This study aimed to investigate the potential role of serum TCTP in liver regeneration after two-thirds partial hepatectomy.

METHODS

The synthesis rate and accumulated expression of TCTP was assessed by phosphor imaging and Western blot analysis, respectively. The mRNA expression of tctp was analyzed by quantitative real-time PCR. The effect of serum TCTP on hepatocyte proliferation was investigated by bromodeoxyuridine incorporation, liver/body weight ratio, albumin concentration, and histological examination of liver following treatment of rat with anti-TCTP antibody or prokaryotic TCTP protein before hepatectomy. The MTT assay was used to examine effect of TCTP on hepatocyte proliferation in vitro.

RESULTS

The results showed that the expression of intracellular and serum TCTP protein was significantly increased in rats after two-thirds partial hepatectomy. In vivo bromodeoxyuridine labeling assay suggested that treatment with anti-TCTP antibody before hepatectomy significantly decreased hepatocyte proliferation and liver/body weight ratio. The prokaryotic TCTP had a potential promoting effect on hepatocyte proliferation both in vivo and in vitro, although prokaryotic TCTP given to rats prior to hepatectomy did not increase the proliferation ratio or liver/body weight ratio. Furthermore, anti-TCTP antibody pretreatment decreased the expression of cyclin E, cdk2, and interleukin-6 in rat liver.

CONCLUSION

These findings suggest serum TCTP is involved in rat liver regeneration through promoting hepatocyte proliferation.

Tetramethylpyrazine protects lymphocytes from radiation-induced apoptosis through nuclear factor-κB

AIM

Radiation induces an important apoptosis response in irradiated organs. The objective of this study was to investigate the radioprotective effect of tetramethylpyrazine (TMP) on irradiated lymphocytes and discover the possible mechanism of protection.

METHOD

Lymphocytes were pretreated for 12 h with TMP (25-200 μmol·L(-1)) and then exposed to 4 Gy radiation. Cell apoptosis and the signaling pathway were analyzed.

RESULTS

Irradiation increased cell death, DNA fragmentation, activated caspase activation and cytochrome c translocation, downregulated B-cell lymphoma 2 (Bcl-2) and up-regulated Bcl-2-associated X protein (Bax). Pretreated with TMP significantly reversed this tendency. Several anti-apoptotic characteristics of TMP, including the ability to increase cell viability, inhibit caspase-9 activation, and upregulate Bcl-2 and down-regulate Bax in 4Gy-irradiated lymphocytes were determined. Signal pathway analysis showed TMP could translate nuclear factor-κB (NF-κB) from cytosol into the nucleus.

CONCLUSION

The results suggest that TMP had a radioprotective effect through the NF-κB pathway to inhibit apoptosis, and it may be an effective candidate for treating radiation diseases associated with cell apoptosis.

Ferulic acid induces heme oxygenase-1 via activation of ERK and Nrf2

This study investigated the effect of ferulic acid (FA) on the up-regulation of heme oxygenase-1 (HO-1) in lymphocytes and the molecular mechanisms involved. Lymphocytes were treated with FA (0.001-0.1 μM) for certain times. Cell viability, the activity and level of expression of HO-1, and signal pathways were analyzed. FA significantly upregulated HO-1 expression both at the level of mRNA and protein in lymphocytes. Moreover, FA induced NF-E2-related factor (Nrf2) nuclear translocation and transcriptional activity, which is upstream of FA induced HO-1 expression. In addition, lymphocytes treated with FA exhibited activation of extracellular regulated kinase (ERK) and treatments with U0126 (an ERK kinase inhibitor) attenuated the FA induced activation of Nrf2, resulting in a decrease in HO-1 expression. Zinc protoporphyrin (ZnPP, a HO-1 inhibitor) markedly suppressed cytoprotection from radiation-induced cell damage by FA. Results suggested that the ERK signaling pathway controlled the anti-oxidation of FA by regulating the expression of the antioxidant enzyme HO-1.