Zhankuic acid A as a novel JAK2 inhibitor for the treatment of concanavalin A-induced hepatitis.

Fruiting bodies of Taiwanofungus camphoratus have been widely used as an antidote for food poisoning and considered to be a precious folk medicine for anti-inflammation and hepatoprotection. Zhankuic acid A (ZAA) is its major pharmacologically active compound. Janus kinase 2 (JAK2), whose activation is involved in cytokine signaling, plays critical roles in the development and biology of the hematopoietic system. JAK2 has been implicated as a therapeutic target in inflammatory diseases. The HotLig modeling approach was used to generate the binding model for ZAA with JAK2, showing that ZAA could bind to the ATP-binding pocket of JAK2 exclusively via the H-bond. The interaction between ZAA and JAK2 was verified by antibody competition assay. Binding of ZAA to JAK2 reduced antibody recognition of native JAK2. The expressions of phosphorylated JAK2 and STATs were analyzed by immuno-blotting. ZAA reduced the phosphorylation and downstream signaling of JAK2, and inhibited the interferon (IFN)-γ/signal transducer and activator of transcription (STAT) 1/interferon regulatory factor (IRF)-1 pathway. The protective effect of ZAA on liver injury was evaluated in mice by Con-A-induced acute hepatitis. Pre-treatment with ZAA also significantly ameliorated acute liver injury in mice. Therefore, ZAA can inhibit JAK2 phosphorylation and protect against liver injury during acute hepatitis in mice. In this study, we present data that ZAA exerts anti-inflammatory effects through the JAK2 signaling pathway. As such, ZAA may be a potential therapeutic agent for the treatment of inflammatory diseases.

Zhankuic acid A isolated from Taiwanofungus camphoratus is a novel selective TLR4/MD-2 antagonist with anti-inflammatory properties.

TLR4, a membrane receptor that functions in complex with its accessory protein myeloid differentiation factor-2 (MD-2), is a therapeutic target for bacterial infections. Taiwanofungus camphoratus is highly valued as a medicinal mushroom for cancer, hypertension, and inflammation in traditional medicine. Zhankuic acid A (ZAA) is the major pharmacologically active compound of T. camphoratus. The mechanism of action of T. camphoratus or ZAA has not been fully elucidated. We analyzed the structure of human TLR4/MD-2 complex with ZAA by X-score and HotLig modeling approaches. Two Abs against MD-2 were used to verify the MD-2/ZAA interaction. The inflammation and survival of the mice pretreated with ZAA and injected with LPS were monitored. The modeling structure shows that ZAA binds the MD-2 hydrophobic pocket exclusively via specific molecular recognition; the contact interface is dominated by hydrophobic interactions. Binding of ZAA to MD-2 reduced Ab recognition to native MD-2, similar to the effect of LPS binding. Furthermore, ZAA significantly ameliorated LPS-induced endotoxemia and Salmonella-induced diarrhea in mice. Our results suggest that ZAA, which can compete with LPS for binding to MD-2 as a TLR4/MD-2 antagonist, may be a potential therapeutic agent for gram-negative bacterial infections.

Scutellaria barbata inhibits angiogenesis through downregulation of HIF-1 α in lung tumor.

Hypoxia, a hallmark of many solid tumors, is associated with angiogenesis and tumor progression. Hypoxia-inducible factor-1 (HIF-1) plays a significant role in tumor angiogenesis. In this study, the authors constructed a selective platform to screen the traditional Chinese medicine as anti-angiogenic agent. The authors examined the molecular mechanism by which Scutellaria barbata regulates HIF-1-dependent expression of vascular endothelial growth factor (VEGF), which is an important angiogenic factor. Hypoxia promotes angiogenesis by increasing VEGF expression and secretion. Herein, the expression of VEGF was decreased by treatment with S. barbata in tumor cells. Meanwhile, S. barbata reduced the migration and proliferation of endothelial cells under hypoxic condition. S. barbata inhibited the expression of HIF-1α, as well as phosphorylated their upstream signal mediators AKT. S. barbata significantly inhibited the tumor growth in vivo and immunohistochemical studies in the tumors revealed decreased intratumoral microvessel density. These results suggest that the traditional Chinese medicine therapy using S. barbata, which exerts anti-angiogenic activities, represents a promising strategy for the treatment of tumors.

Brief report: amelioration of collagen-induced arthritis in mice by lentivirus-mediated silencing of microRNA-223.

OBJECTIVE: MicroRNA (miRNA) plays a role in autoimmune diseases. MiRNA-223 (miR-223) is up-regulated in patients with rheumatoid arthritis (RA) and is involved in osteoclastogenesis, which contributes to erosive disease. The aim of this study was to test the feasibility of using lentiviral vectors expressing the miR-223 target sequence (miR-223T) to suppress miR-223 activity as a therapeutic strategy in a mouse model of collagen-induced arthritis (CIA). METHODS: Levels of miR-223 in the synovial tissue of patients with RA or osteoarthritis (OA), as well as in the ankle joints of mice with CIA, were determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Lentiviral vectors expressing miR-223T (LVmiR-223T) or luciferase short hairpin RNA (LVshLuc) as a control vector were injected intraperitoneally into mice with CIA. Treatment responses and disease-related bone mineral density were monitored. Levels of nuclear factor 1A (NF-1A), a direct target of miR-223, and macrophage colony-stimulating factor receptor (M-CSFR), which is critical for osteoclastogenesis, were measured by immunohistochemistry and quantitative RT-PCR. Osteoclasts were assessed by tartrate-resistant acid phosphatase staining. RESULTS: MiR-223 expression was significantly higher in the synovium of RA patients and in the ankle joints of mice with CIA as compared to OA patients and normal mice. LVmiR-223T treatment reduced the arthritis score, histologic score, miR-223 expression, osteoclastogenesis, and bone erosion in mice with CIA. Down-regulation of miR-223 with concomitant increases in NF-1A levels and decreases in M-CSFR levels was detected in the synovium of LVmiR-223T-treated mice. CONCLUSION: This study is the first to demonstrate that lentivirus-mediated silencing of miR-223 can reduce disease severity of experimental arthritis. Furthermore, our results indicate that inhibition of miR-223 activity should be further explored as a therapeutic strategy in RA.

B cells are required for tumor-targeting Salmonella in host.

Systemic administration of Salmonella to tumor-bearing mice leads to the preferential accumulation within tumor sites and retardation of the tumor growth. Host factors including innate and adaptive immune responses influence Salmonella-induced antitumor activity. Antitumor activities of Salmonella are not only determined by the tumor regression but also by the host immune response. Herein, we demonstrated that B cells play an important role in the antitumor activity mediated by Salmonella. Body weight and survival of B cell-deficient mice were decreased compared with wild-type, CD8(+) cell-deficient, or CD4(+) cell-deficient mice after Salmonella administration. Although Salmonella accumulated within the tumors in B cell-deficient mice, the bacterial loads of healthy organs were higher than those in wild-type mice. The inflammation cytokine and bacteremia were found in B cell-deficient mice after Salmonella treatment. When Salmonella accumulated within the tumor, B cells inhibited the dissemination of Salmonella to other healthy organs. The depletion of host B cells resulted in a noticeably higher total number of Salmonella in the tumor and inhibited tumor growth. Meanwhile, B cell-depletive and B cell-adoptive transfer of serum experiments demonstrated that the natural antibody produced by B cell takes part in the control of Salmonella dissemination in tumor-bearing mice. In this study, we want to address the mechanisms of incorporating host immunoresponse as a way to augment the antitumor activities of Salmonella.

T cell augments the antitumor activity of tumor-targeting Salmonella.

Systemic administration of Salmonella to tumor-bearing mice leads to preferential accumulation within tumor sites and retardation of tumor growth. However, the detailed mechanism of Salmonella-induced antitumor immune response via host T cell remains uncertain. Herein, we used wild-type, CD4(+) T-cell-deficient, and CD8(+) T-cell-deficient mice to study the role of T cell in the antitumor immune responses induced by Salmonella enterica serovar Choleraesuis (Salmonella Choleraesuis). When systemically administered into mice bearing tumors, Salmonella Choleraesuis significantly inhibited tumor growth by 50%. In contrast, in T-cell-deficient mice, there was only 34-42% inhibition of tumor growth. We found that treatment with Salmonella Choleraesuis significantly upregulates interferon-γ in wild-type and CD8(+) T-cell-deficient mice, but not in CD4(+) T-cell-deficient mice. Furthermore, immunohistochemical staining of the tumors revealed more infiltration of macrophages and neutrophils in wild-type mice after Salmonella Choleraesuis treatment compared with those in T-cell-deficient mice. The antitumor therapeutic effect mediated by Salmonella Choleraesuis is associated with an inflammatory immune response at the tumor site and a tumor T helper 1-type immune response. In conclusion, these results suggest that tumor-targeted therapy using Salmonella Choleraesuis, which exerts tumoricidal effects and stimulates T cell activities, represents a potential strategy for the treatment of tumor.

Amelioration of rat collagen-induced arthritis through CD4+ T cells apoptosis and synovial interleukin-17 reduction by indoleamine 2,3-dioxygenase gene therapy.

Indoleamine 2,3-dioxygenase (IDO) has been known as an emerging therapeutic target in autoimmunity-related arthritis. The treatment responses of adenoviral vectors encoding IDO (AdIDO) gene therapy in rat collagen-induced arthritis (CIA) were examined in this study. The therapeutic effects on ankle circumference, articular index, and radiographic and histological scores were evaluated in AdIDO-injected ankle joints. We further determined CD4+ T-cell numbers and their apoptotic status, CD68(+) macrophage numbers, kynurenine (a downstream tryptophan metabolite) concentrations, interleukin-17 (IL-17) levels, and retinoic acid-related orphan receptor γt (RORγt) expression in synovial tissues of CIA rats receiving AdIDO treatment. Reduction of ankle circumference, articular index, and radiographic and histological scores were noted in AdIDO-treated ankles, as compared with those receiving injection of control vectors. Furthermore, IDO gene transfer led to decreased infiltrating CD4+ T cells with enhanced apoptosis, reduced CD68+ macrophage numbers, increased kynurenine levels, lower IL-17 concentrations, and decreased RORγt expression within the ankle joints. In addition, such a therapy diminished type II collagen-specific IL-17 production and RORγt expression in CD4+ T cells from draining lymph nodes of CIA rats. Our results demonstrate for the first time that intra-articular delivery of IDO gene ameliorated ankle arthritis of CIA rats by induction of CD4+ T-cell apoptosis and reduction of synovial IL-17 production through the supplement of kynurenine. Taken together, these findings implicate the novel strategy of using IDO gene as a therapeutic approach in treating patients with rheumatoid arthritis.

Licorice and licochalcone-A induce autophagy in LNCaP prostate cancer cells by suppression of Bcl-2 expression and the mTOR pathway.

Licorice is a common Chinese medicinal herb with antitumor activity. Some components in licorice root have been shown to induce cell cycle arrest or apoptosis in cancer cells. This paper demonstrates for the first time that licorice Glycyrrhiza glabra and its component licochalcone-A (LA) can induce autophagy in addition to apoptosis in human LNCaP prostate cancer cells. Exposure of cells to licorice or LA resulted in several confirmed characteristics of autophagy, including the appearance of autophagic vacuoles revealed by monodansylcadaverine (MDC) staining, formation of acidic vesicular organelles (AVOs), and autophagosome membrane association of microtubule-associated protein 1 light chain 3 (LC3) characterized by cleavage of LC3 and its punctuate redistribution, as well as ultrastructural observation of autophagic vacuoles by transmission electron microscopy. Autophagy induction was accompanied by down-regulation of Bcl-2 and inhibition of the mammalian target of rapamycin (mTOR) pathway. In summary, licorice can induce caspase-dependent and autophagy-related cell death in LNCaP cells.