No abstract

Rosmarinic acid (α-o-caffeoyl-3,4-dihydroxyphenyllactic acid, RA) is a major active constituent of Rosmarinus officinalis Linn. (rosemary) having significant anti-inflammatory, anti-apoptotic, and antioxidant effects. However, the cardioprotection of RA is still not understood. The present study was designed, for the first time, to investigate the cardioprotection of RA on myocardial infarction (MI)-induced cardiac fibrosis and to clarify the possible mechanisms. MI was induced in adult rats by left anterior descending coronary artery ligation, and animals were then administered RA (50, 100, or 200 mg/kg) by gavage. Compared with the model group, RA treatment ameliorated changes in the left ventricular systolic pressure (LVSP), +dp/dtmax, and -dp/dtmax after 4 weeks. This was associated with attenuation of infarct size, collagen volume fraction (CVF), expression of collagen I, collagen III, alpha smooth muscle actin (α-SMA), and hydroxyproline (Hyp) concentrations. RA treatment was also associated with decreased angiotensin-converting enzyme (ACE) expression and increased ACE2 expression, as well as decreased expression of angiotensin type 1 receptor (AT1R) and phospho-p38 mitogen-activated protein kinase (p38 MAPK). Thus, RA can protect against cardiac dysfunction and fibrosis following MI, likely due to decreasing ACE expression and increasing ACE2 expression via the AT1R/p38 MAPK pathway.

Indoleamine 2,3-dioxygenase (IDO) is involved in tumor immune escape and resistance to chemotherapy, and is clinically correlated with tumor progression. IDO inhibitors show marginal efficacy as single agents; therefore, combinations of these inhibitors with other therapies hold promise for cancer therapy. The aim of this study was to investigate the synergistic antitumor effects of IDO inhibitor NLG919 in combination with different regimens of paclitaxel in a murine B16-F10 melanoma model. NLG919 increased the cytotoxic activity of paclitaxel toward B16-F10 cells in the presence of pretreatment with interferon (IFN)-γ in vitro. In B16-F10 tumor-bearing mice, NLG919 was uniformly distributed throughout tumors and decreased kynurenine levels and kynurenine/tryptophan ratios in tumors and plasma for 6–12 h. NLG919 suppressed tumor growth in a dose-dependent manner and exhibited maximum efficacy at 100 mg/kg. In combination with different regimens of paclitaxel, NLG919 displayed synergistic antitumor effects, and NLG919 did not increase the side effects of paclitaxel. Within the tumors, the percentage of CD3+, CD8+, and CD4+ T cells and secretion of IFN-γ and interleukin-2 were synergistically increased, whereas the percentage of CD4+CD25+ regulatory T cells was decreased. NLG919 can potentiate the antitumor efficacy of paclitaxel without increasing its side effects, suggesting that the combination of IDO inhibitor-based immunotherapy with chemotherapy could be a potential strategy for cancer treatment.

No abstract

Glucagon is a peptide hormone secreted by islet α cells. It plays crucial roles in glucose homeostasis and metabolism by activating its cognate glucagon receptor (GCGR). A naturally occurring deleterious mutation V368M in the human GCGR leads to reduced ligand binding and down-regulation of glucagon signaling. To examine the association between this mutation and metabolic disorders, a knock-in mouse model bearing homozygous V369M substitution (equivalent to human V368M) in GCGR was made using CRISPR-Cas9 technology. These GcgrV369M+/+ mice displayed lower fasting blood glucose levels with improved glucose tolerance compared with wild-type controls. They also exhibited hyperglucagonemia, pancreas enlargement and α cell hyperplasia with a lean phenotype. Additionally, V369M mutation resulted in a reduction in adiposity with normal body weight and food intake. Our findings suggest a key role of V369M/V368M mutation in GCGR-mediated glucose homeostasis and pancreatic functions, thereby pointing to a possible interplay between GCGR defect and metabolic disorders.