Immunization of Mice with Recombinant Protein CobB or AsnC Confers Protection against Brucella abortus Infection

Due to drawbacks of live attenuated vaccines, much more attention has been focused on screening of Brucella protective antigens as subunit vaccine candidates. Brucella is a facultative intracellular bacterium and cell mediated immunity plays essential roles for protection against Brucella infection. Identification of Brucella antigens that present T-cell epitopes to the host could enable development of such vaccines. In this study, 45 proven or putative pathogenesis-associated factors of Brucella were selected according to currently available data. After expressed and purified, 35 proteins were qualified for analysis of their abilities to stimulate T-cell responses in vitro. Then, an in vitro gamma interferon (IFN-γ) assay was used to identify potential T-cell antigens from B. abortus. In total, 7 individual proteins that stimulated strong IFN-γ responses in splenocytes from mice immunized with B. abortus live vaccine S19 were identified. The protective efficiencies of these 7 recombinant proteins were further evaluated. Mice given BAB1_1316 (CobB) or BAB1_1688 (AsnC) plus adjuvant could provide protection against virulent B. abortus infection, similarly with the known protective antigen Cu-Zn SOD and the license vaccine S19. In addition, CobB and AsnC could induce strong antibodies responses in BALB/c mice. Altogether, the present study showed that CobB or AsnC protein could be useful antigen candidates for the development of subunit vaccines against brucellosis with adequate immunogenicity and protection efficacy

Preclinical Evaluation of Liposomal C8 Ceramide as a Potent anti-Hepatocellular Carcinoma Agent.

Hepatocellular carcinoma (HCC) remains a global health threat. The search for novel anti-HCC agents is urgent. In the current study, we synthesized a liposomal C8 ceramide, and analyzed its anti-tumor activity in pre-clinical HCC models. The liposomal C8 (ceramide) potently inhibited HCC cell (HepG2, SMMC-7721 and Huh-7 lines) survival and proliferation, more efficiently than free C8 ceramide. Yet, non-cancerous HL7702 human hepatocytes were resistant to the liposomal C8 treatment. Liposomal C8 activated caspase-dependent apoptosis in HCC cells, and HCC cytotoxicity by liposomal C8 was significantly attenuated with co-treatment of caspase inhibitors. At the molecular level, we showed that liposomal C8 activated ASK1 (apoptosis signal-regulating kinase 1)-JNK (Jun N-terminal protein kinase) signaling in HCC cells. On the other hand, JNK pharmacological inhibition or dominant negative mutation, as well as ASK1 shRNA-knockdown remarkably inhibited liposomal C8-induced apoptosis in HCC cells. Further studies showed that liposomal C8 inhibited AKT-mTOR (mammalian target of rapamycin) activation in HCC cells. Restoring AKT-mTOR activation by introducing a constitutively-active AKT alleviated HepG2 cytotoxicity by liposomal C8. In vivo, intravenous (i.v.) injection of liposomal C8 significantly inhibited HepG2 xenograft growth in severe combined immuno-deficient (SCID) mice, and mice survival was significantly improved. These preclinical results suggest that liposomal C8 could be further studied as a valuable anti-HCC agent

Nature-mimic fabricated polydopamine/MIL-53(Fe): efficient visible-light responsive photocatalysts for the selective oxidation of alcohols

Polydopamine/MIL-53(Fe) (PDA/MIL-53(Fe)) nanocomposite photocatalysts were synthesized with PDA (PDA = polydopamine) and MIL-53(Fe) using a nature-mimicking method. The structures, morphologies, optical properties and thermal stabilities of all the synthesized materials were characterized using a series of methods. In particular, the separation efficiency of photogenerated charge significantly increased after the incorporation of PDA into MIL-53(Fe), which resulted in an elevated photocatalytic activity of PDA/MIL-53(Fe) compared with the control groups. The PDA/MIL-53(Fe) nanocomposite could accelerate the conversion of primary or secondary alcohols into the corresponding aldehydes or ketones with a high specificity by direct hole-involving oxidation under visible-light irradiation and room temperature. The catalysts could be cycled at least three times without a significant decrease in the catalytic activity and this result showed the excellent recyclability and stability of the catalysts

Celastrol suppresses tumor cell growth through targeting an AR-ERG-NF-κB pathway in TMPRSS2/ERG fusion gene expressing prostate cancer.

The TMPRSS2/ERG (T/E) fusion gene is present in the majority of all prostate cancers (PCa). We have shown previously that NF-kB signaling is highly activated in these T/E fusion expressing cells via phosphorylation of NF-kB p65 Ser536 (p536). We therefore hypothesize that targeting NF-kB signaling may be an efficacious approach for the subgroup of PCas that carry T/E fusions. Celastrol is a well known NF-kB inhibitor, and thus may inhibit T/E fusion expressing PCa cell growth. We therefore evaluated Celastrol's effects in vitro and in vivo in VCaP cells, which express the T/E fusion gene. VCaP cells were treated with different concentrations of Celastrol and growth inhibition and target expression were evaluated. To test its ability to inhibit growth in vivo, 0.5 mg/kg Celastrol was used to treat mice bearing subcutaneous VCaP xenograft tumors. Our results show Celastrol can significantly inhibit the growth of T/E fusion expressing PCa cells both in vitro and in vivo through targeting three critical signaling pathways: AR, ERG and NF-kB in these cells. When mice received 0.5 mg/kg Celastrol for 4 times/week, significant growth inhibition was seen with no obvious toxicity or significant weight loss. Therefore, Celastrol is a promising candidate drug for T/E fusion expressing PCa. Our findings provide a novel strategy for the targeted therapy which may benefit the more than half of PCa patients who have T/E fusion expressing PCas

Liposomal C8 ceramide administration inhibits HepG2 cell growth in SCID mice, while dramatically improving mice survival.

<p>HepG2 xenograft-bearing SCID mice (10 mice per group) were intravenously (<i>i</i>.<i>v</i>.) injected with liposomal C8 (5/15 mg/kg body weight, once every two days, 30 days), liposomal vehicle control (no ceramide, “Lipo Ctrl”) or Saline, HepG2 xenograft volumes (A) and mice body weights (D) were recorded every 10 days, tumor growth (in mm³/day) was also presented (B). Mice survival at day 50 was shown (C). At day 50, xenografted tumors were isolated (n = 3 for each group), expression of listed proteins in the tumor tissues was tested by Western blot (E-G). Protein expression was quantified (E-G). <i>In vivo</i> experiments were repeated twice, and similar results were obtained. * indicates statistically significant differences compared to “Saline” group.</p

Liposomal C8 ceramide induces caspase-dependent apoptosis in HCC cells.

<p>HepG2 (A-E), SMMC-7721 (F) and Huh-7 (F) human HCC cells, as well as HL7702 human hepatocytes (F) were treated with applied concentrations of liposomal C8 for indicated time, cell apoptosis was tested by the assays described (A-C, F). HepG2 cells, pretreated with the caspase 3 specific inhibitor z-VAD-fmk (“cas3-i”, 30 μM) or the caspase-9 specific inhibitor Z-LEHD-fmk (“cas9-i”, 30 μM) for 1 h, were treated with liposomal C8 (10 μM), cells were then further cultured, and cell proliferation and cell death were tested by MTT assay (D) and trypan blue assay (E), respectively. Data represent the means of three independent experiments ± SD. The asterisks (*) indicate statistically significant differences compared to “C” group. ^# indicates statistically significant differences compared to liposomal C8 only group (D and E).</p

ASK1-JNK activation contributes to liposomal C8 ceramide-induced activity against HCC cells.

<p>HepG2 cells were treated with applied concentrations of liposomal C8 for indicated time, expressions of indicated proteins were tested Western blots (A). HepG2 cells, pretreated with JNK inhibitor IX (“JNKi”, 0.25 μM) or SP600125 (“SP”, 5 μM) for 1 h, were treated with liposomal C8 (10 μM), cell proliferation (B) and apoptosis (C) were tested. Control HepG2 cells, or the stable HepG2 cells expressing dominant negative JNK1 (“dn-JNK1”) or empty vector (pSuper), were treated with liposomal C8 (10 μM) for applied time, Western blots were utilized to test the signaling changes (D), cell proliferation (E) and cell apoptosis (F) were also tested. Control HepG2 cells, as well as stable HepG2 cells expressing scramble control shRNA (“sc-shRNA”) or ASK1-shRNA were treated with liposomal C8 (10 μM) for applied time, signaling changes (G), cell proliferation (H) and apoptosis (I) were tested as described. Expressions of listed proteins were quantified (A, D and G, a total of three repeats). Data represent the means of three independent experiments ± SD. The asterisks (*) indicate statistically significant differences compared to “C” group. ^# indicates statistically significant differences compared to liposomal C8 only group of “no shRNA” or “Vector” group.</p

Liposomal C8 ceramide inhibits AKT-mTOR activation in HCC cells.

<p>HepG2 (A), SMMC-7721 (B) and Huh-7 (C) HCC cells were treated with applied concentrations of liposomal C8 for indicated time, expressions of indicated proteins were tested Western blots (A-C). Control HepG2 cells (“Ctrl”), as well as stable HepG2 cells expressing constitutively-active AKT1 (“ca-AKT1”) or empty vector (Ad-GFP) were treated with liposomal C8, Western blots were applied to test listed proteins (D), subsequent cell death (E) and apoptosis (F) were also tested. Expressions of indicated proteins were quantified (A-D, a total of three repeats). Data represent the means of three independent experiments ± SD. The asterisk (*) indicates statistically significant differences compared to “C” group. ^# indicates statistically significant differences compared to liposomal C8 only group of “Ctrl” cells (E and F).</p

Liposomal C8 ceramide inhibits HCC cell proliferation and survival.

<p>HepG2 (A-D), SMMC-7721 (E and F) and Huh-7 (E and F) human HCC cells, as well as HL7702 human hepatocytes (E and F) were either left untreated (“C”, same for all figures), or treated with applied concentrations of liposomal C8 ceramide (“Lipo C8”, same for all figures) or free C8 ceramide (For “A”) for indicated time, cell proliferation was tested by MTT assay (A, B and E) or clonogenicity assay (C, for HepG2 cells), and cell death was tested by trypan blue staining assay (D and F). Data represent the means of three independent experiments ± standard deviations (SD). The asterisks (*) indicate statistically significant differences compared to “C” group.</p

Tandem Molecular Self-Assembly Selectively Inhibits Lung Cancer Cells by Inducing Endoplasmic Reticulum Stress

The selective formation of nanomaterials in cancer cells and tumors holds great promise for cancer diagnostics and therapy. Until now, most strategies rely on a single trigger to control the formation of nanomaterials in situ. The combination of two or more triggers may provide for more sophisticated means of manipulation. In this study, we rationally designed a molecule (Comp. 1) capable of responding to two enzymes, alkaline phosphatase (ALP), and reductase. Since the A549 lung cancer cell line showed elevated levels of extracellular ALP and intracellular reductase, we demonstrated that Comp. 1 responded in a stepwise fashion to those two enzymes and displayed a tandem molecular self-assembly behavior. The selective formation of nanofibers in the mitochondria of the lung cancer cells led to the disruption of the mitochondrial membrane, resulting in an increased level of reactive oxygen species (ROS) and the release of cytochrome C (Cyt C). ROS can react with proteins, resulting in endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). This severe ER stress led to disruption of the ER, formation of vacuoles, and ultimately, apoptosis of the A549 cells. Therefore, Comp. 1 could selectively inhibit lung cancer cells in vitro and A549 xenograft tumors in vivo. Our study provides a novel strategy for the selective formation of nanomaterials in lung cancer cells, which is powerful and promising for the diagnosis and treatment of lung cancer