Bioactive hyaluronic acid fragments inhibit lipopolysaccharide-induced inflammatory responses via the Toll-like receptor 4 signaling pathway
FRONTIERS OF MEDICINE
Authors: You, Na; Chu, Sasa; Cai, Binggang; Gao, Youfang; Hui, Mizhou; Zhu, Jin; Wang, Maorong
Abstract
The high- and the low-molecular weight hyaluronic acids (HMW-HA and LMW-HA, respectively) showed different biological activities in inflammation. However, the role of LMW-HA in inflammatory response is controversial. In this study, we aimed to investigate the effect of bioactive hyaluronan (B-HA) on lipopolysaccharide (LPS)-induced inflammatory responses in human macrophages and mice. B-HA was produced from HA treated with glycosylated recombinant human hyaluronidase PH20. Human THP-1 cells were induced to differentiate into macrophages. THP-1-derived macrophages were treated with B-HA, LPS, or B-HA + LPS. The mRNA expression and the production of inflammatory cytokines were determined using quantitative real-time PCR and enzyme-linked immunosorbent assay. The phosphorylation levels of proteins in the nuclear factor-kappa B (NF-kappa B), mitogen-activated protein kinase (MAPK), and IRF-3 signaling pathways were measured using Western blot. Thein vivoefficacy of B-HA was assessed in a mouse model of LPS-induced inflammation. Results showed that B-HA inhibited the expression of TNF-alpha, IL-6, IL-1, and IFN-beta, and enhanced the expression of the antiinflammatory cytokine IL-10 in LPS-induced inflammatory responses in THP-1-derived macrophages andin vivo. B-HA significantly suppressed the phosphorylation of the TLR4 signaling pathway proteins p65, IKK alpha/beta, I kappa B alpha, JNK1/2, ERK1/2, p38, and IRF-3. In conclusion, our results demonstrated that the B-HA attenuated the LPS-stimulated inflammatory response by inhibiting the activation of the TLR4 signaling pathway. B-HA could be a potential anti-inflammatory drug in the treatment of inflammatory disease.
Eprinomectin, a novel semi-synthetic macrocylic lactone is cytotoxic to PC3 metastatic prostate cancer cells via inducing apoptosis
TOXICOLOGY AND APPLIED PHARMACOLOGY
Authors: Samy, Angela Lincy Prem Antony; Bakthavachalam, Velavan; Vudutha, Mona; Vinjamuri, Smita; Chinnapaka, Somaiah; Munirathinam, Gnanasekar
Abstract
Prostate Cancer (PCa) is the second most common cancer among men in United States after skin cancer. Conventional chemotherapeutic drugs available for PCa treatment are limited due to toxicity and resistance issues. Therefore, there is an urgent need to develop more effective treatment for advanced PCa. In this current study, we focused on evaluating the anti-cancer efficacy of Eprinomectin (EP), a novel avermectin analog against PC3 metastatic PCa cells. EP displayed robust inhibition of cell viability of PC3 cells in addition to suppressing the colony formation and wound healing capabilities. Our study showed that EP targets PC3 cells via inducing ROS and apoptosis activation. EP treatment enforces cell cycle arrest at G0/G1 phase via targeting cyclin-dependent kinase 4 (CDK4) and subsequent induction of apoptosis in PC3 cells. At the molecular level, EP effectively inhibited the expression of various cancer stem cell markers such as ALDH1, Sox-2, Nanog, Oct3/4 and CD44. Interestingly, EP also inhibited the activity of alkaline phosphatase, a maker of pluripotent stem cells. Of note, EP treatment resulted in the translocation of beta-catenin from the nucleus to the cytoplasm indicating that EP antagonizes Wnt/beta-catenin signaling pathway. Western blotting analysis revealed that EP downregulated the expression of key cell cycle markers such as cyclin D1, cyclin D3, CDK4, and c-Myc. In addition, EP inhibited the anti-apoptotic markers such as Mcl-1, XIAP, c-IAP1 and survivin in PC3 cells. On the other hand, EP treatment resulted in the activation of pH2A.X, Bad, caspase-9, caspase-3 and cleavage of PARP1. Taken together, our data suggests that EP is a potential agent to treat advanced PCa cells via modulating apoptosis signaling.