Ligustrazine alleviates pulmonary arterial hypertension in rats by promoting the formation of myocardin transcription complex in the nucleus of pulmonary artery smooth muscle cells.

Pulmonary arterial hypertension (PAH) is a pathophysiological state of abnormally elevated pulmonary arterial pressure caused by drugs, inflammation, toxins, viruses, hypoxia, and other risk factors. We studied the therapeutic effect and target of tetramethylpyrazine (tetramethylpyrazine [TMP]; ligustrazine) in the treatment of PAH and we speculated that dramatic changes in myocardin levels can significantly affect the progression of PAH. In vivo, the results showed that administration of TMP significantly prolonged the survival of PAH rats by reducing the proliferative lesions, right ventricular systolic pressure (RVSP), mean pulmonary arterial pressure (mPAP), and the Fulton index in the heart and lung of PAH rats. In vitro, TMP can regulate the levels of smooth muscle protein 22-alpha (SM22-α), and myocardin as well as intracellular cytokines such as NO, transforming growth factor beta (TGF-ß), and connective tissue growth factor (CTGF) in a dose-dependent manner (25, 50, or 100 µM). Transfection of myocardin small interfering RNA (siRNA) aggravated the proliferation of pulmonary artery smooth muscle cells (PSMCs), and the regulatory effect of TMP on α-smooth muscle actin (α-SMA) and osteopontin (OPN) disappeared. The application of 10 nM estrogen receptor alpha (ERα) inhibitor MPP promoted the proliferation of PSMCs, but it does not affect the inhibition of TMP on PSMCs proliferation. Finally, we found that TMP promoted the nucleation of myocardin-related transcription factor-A (MRTF-A) and combined it with myocardin. In conclusion, TMP can inhibit the transformation of PSMCs from the contractile phenotype to the proliferative phenotype by promoting the formation of the nuclear (MRTF-A/myocardin) transcription complex to treat PAH.

Inhibition of glutamine transporter ASCT2 mitigates bleomycin-induced pulmonary fibrosis in mice.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) represents a fatal pulmonary disease. Its mechanisms remain unclear and effective therapies are urgently needed. Glutaminolysis is involved in IPF pathology, but little is known about the role of ASCT2 responsible for cellular uptake of glutamine in IPF. We investigated the role of ASCT2 and its therapeutic implication in IPF through knockdown of ASCT2 in mice. METHODS: Mouse IPF model was established through a single intratracheal administration of bleomycin, and lentivirus-coated ASCT2 siRNA was administrated into mice via caudal vein for knockdown of ASCT2. Mouse blood and lung tissues were collected for biochemical, histological, and molecular examinations. RESULTS: ASCT2 siRNA significantly lowered ASCT2 expression in mouse lung tissues. Knockdown of ASCT2 reduced pulmonary levels of glutamic acid, α-ketoglutarate, glutathione and ATP, mitigated pulmonary histological injury, and reduced serum concentrations of pulmonary injury parameters including SP-A, SP-D, KL-6 and CCL18 in IPF mice. Moreover, serum levels of fibrotic parameters HA, LN, PC-III and IV-C were lowered by ASCT2 depletion. Collagen production and pulmonary hydroxyproline levels were also decreased by ASCT2 siRNA in IPF mice, which was concomitant with downregulation of α-smooth muscle actin, collagen type Iα1 and transforming growth factor-ß receptor II. Furthermore, ASCT2 deficiency downregulated the mRNA and protein expression of inflammatory cytokines IL-1ß and TNF-α as well as macrophage marker F4/80 in lung tissues of IPF mice. CONCLUSIONS: Inhibition of ASCT2 effectively mitigated pulmonary injury, fibrosis and inflammation in mice with bleomycin-induced IPF. ASCT2 could be a novel therapeutic target for treatment of IPF.

Bioinformatics Analysis of Key Genes and Pathways in Colorectal Cancer.

Colorectal cancer (CRC) is the third most prevalent cancer in the world. Although great progress has been made, the specific molecular mechanism remains unclear. This study aimed to explore the differentially expressed genes (DEGs) and underlying mechanisms of CRC using bioinformatics analysis. In this study, we identified a total of 1353 DEGs in the database of GSE113513, including 715 up- and 638 downregulated genes. Gene ontology analysis results showed that upregulated DEGs were significantly enriched in cell division, cell proliferation, and DNA replication. The downregulated DEGs were enriched in immune response, relation of cell growth and inflammatory response. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that upregulated DEGs were enriched in cell cycle and p53 signaling pathway, whereas the downregulated DEGs were enriched in drug metabolism, metabolism of xenobiotics by cytochrome P450, and nitrogen metabolism. A total of 124 up-key genes and 35 down-key genes were identified from the protein-protein interaction networks. Furthermore, we identified five up-modules (up-A, up-B, up-C, up-D, and up-E) and three down-modules (d-A, d-B, and d-C) by module analysis. The module up-A was enriched in sister chromatid cohesion, cell division, and mitotic nuclear division. Pathways associated with cell cycle, progesterone-mediated oocyte maturation, oocyte meiosis, and p53 signaling pathway. Whereas the d-A was mainly enriched in G-protein coupled receptor signaling pathway, cell chemotaxis, and chemokine-mediated signaling pathway. The pathways enriched in chemokine signaling pathway, cytokine-cytokine receptor interaction, and alcoholism. These key genes and pathways might be used as molecular targets and diagnostic biomarkers for the treatment of CRC.