Pyrazinamide (PZA) is a first-line tuberculosis drug that plays a unique role in shortening the duration of tuberculosis chemotherapy. PZA is hydrolyzed intracellularly to pyrazinoic acid (POA) by pyrazinamidase (PZase), an enzyme frequently lost in PZA-resistant strains, but the downstream target of POA in Mycobacterium tuberculosis (Mtb) has remained elusive. Here we identify a new target of POA as the ribosomal protein S1 (RpsA), a vital protein involved in protein translation and the ribosome-sparing process of trans-translation. Affinity chromatography using immobilized POA selectively retained RpsA and a PZA-resistant clinical isolate without pncA mutation harbored an alanine deletion in its C-terminus. RpsA overexpression conferred increased PZA resistance and we confirmed biochemically that POA bound to RpsA (but not the ΔAla mutant) and inhibited trans-translation rather than canonical translation. Trans-translation is essential for freeing scarce ribosomes in non-replicating organisms and its inhibition may explain the unique ability of PZA to eradicate persisting organisms.

Sepsis is the principal cause of fatality in the intensive care units worldwide. It involves uncontrolled inflammatory response resulting in multi-organ failure and even death. Micheliolide (MCL), a sesquiterpene lactone, was reported to inhibit dextran sodium sulphate (DSS)-induced inflammatory intestinal disease, colitis-associated cancer and rheumatic arthritis. Nevertheless, the role of MCL in microbial infection and sepsis is unclear. We demonstrated that MCL decreased lipopolysaccharide (LPS, the main cell wall component of Gram-negative bacteria)-mediated production of cytokines (IL-6, TNF-α, MCP-1, etc) in Raw264.7 cells, primary macrophages, dendritic cells and human monocytes. MCL plays an anti-inflammatory role by inhibiting LPS-induced activation of NF-κB and PI3K/Akt/p70S6K pathways. It has negligible impact on the activation of mitogen-activated protein kinase (MAPK) pathways. In the acute peritonitis mouse model, MCL reduced the secretion of IL-6, TNF-α, IL-1β, MCP-1, IFN-β and IL-10 in sera, and ameliorated lung and liver damage. MCL down-regulated the high mortality rate caused by lethal LPS challenge. Collectively, our data illustrated that MCL enabled maintenance of immune equilibrium may represent a potentially new anti-inflammatory and immunosuppressive drug candidate in the treatment of sepsis and septic shock.

Tuberculosis (TB) remains a leading killer worldwide among infectious diseases and the effective control of TB is still challenging. Autophagy is an intracellular self-digestion process which has been increasingly recognized as a major host immune defense mechanism against intracellular microorganisms like Mycobacterium tuberculosis (Mtb) and serves as a key negative regulator of inflammation. Clinically, chronic inflammation surrounding Mtb can persist for decades leading to lung injury that can remain even after successful treatment. Adjunct host-directed therapy (HDT) based on both antimycobacterial and anti-inflammatory interventions could be exploited to improve treatment efficacy and outcome. Autophagy occurring in the host macrophages represents a logical host target. Here, we show that herbal medicine, baicalin, could induce autophagy in macrophage cell line Raw264.7 and caused increased killing of intracellular Mtb. Further, baicalin inhibited Mtb-induced NLRP3 inflammasome activation and subsequent inflammasome-derived IL-1β. To investigate the molecular mechanisms of baicalin, the signaling pathways associated with autophagy were examined. Results indicated that baicalin decreased the levels of phosphorylated protein kinase B (p-Akt) and phosphorylated mammalian target of rapamycin (p-mTOR) at Ser473 and Ser2448, respectively, but did not alter the phosphorylation of p38, JNK, or ERK both in Raw264.7 and primary peritoneal macrophages. Moreover, baicalin exerted an obvious inhibitory effect on nuclear factor-kappa B (NF-κB) activity. Finally, immunofluorescence studies demonstrated that baicalin promoted the co-localization of inflammasome with autophagosome may serve as the underlying mechanism of autophagic degradative effect on reducing inflammasome activation. Together, baicalin definitely induces the activation of autophagy on the Mtb-infected macrophages through PI3K/Akt/mTOR pathway instead of MAPK pathway. Furthermore, baicalin inhibited the PI3K/Akt/NF-κB signal pathway, and both autophagy induction and NF-κB inhibition contribute to limiting the NLRP3 inflammasome as well as subsequent production of pro-inflammatory cytokine IL-1β. Based on these results, we conclude that baicalin is a promising antimycobacterial and anti-inflammatory agent which can be a novel candidate for the development of new adjunct drugs targeting HDT for possible improved treatment.

The present study was designed to explore the cross talk between fatty acid synthase (FASN) and HER2 (ErbB2) in ovarian cancer. A total of 60 ovarian cancer patients and 15 normal ovarian tissues were enrolled. Tissue array was conducted by using a tissue microarray instrument. Immunohistochemistry was performed to quantify the expressions of HER2 and FASN. The FASN was detected to be distributed in the cell cytoplasm and was significantly correlated with cancer grade (p = 0.000) and FIGO staging (p = 0.000). Patients with FASN overexpression in ovarian cancer tend to have a worse overall survival rate (p = 0.000). HER2 was also stained to be distributed in the cell cytoplasm associated with higher expression in high-grade cancer. It was also disclosed that FASN expression level is not correlated with HER2 status in ovarian cancer. These results for the first time indicated that a cross talk in FASN and HER2 expressions might be associated with prognosis in malignant ovarian cancer.

In clinical therapy, the poor prognosis of hepatocellular carcinoma (HCC) is mainly attributed to the failure of chemotherapeutical agents to accumulate in tumor as well as their serious systemic toxicity. In this work, we developed actively tumor-targeting trilayer micelles with microenvironment-sensitive cross-links as a novel nanocarrier for HCC therapy. These micelles comprised biodegradable PEG-pLys-pPhe polymers, in which pLys could react with a disulfide-containing agent to form redox-responsive cross-links. In vitro drug release and pharmacokinetics studies showed that these cross-links were stable in physiological condition whereas cleaved once internalized into cells due to the high level of glutathione, resulting in facilitated intracellular doxorubicin release. In addition, dehydroascorbic acid (DHAA) was decorated on the surface of micelles for specific recognition of tumor cells via GLUT1, a member of glucose transporter family overexpressed on hepatocarcinoma cells. Moreover, DHAA exhibited a "one-way" continuous accumulation within tumor cells. Cellular uptake and in vivo imaging studies proved that these micelles had remarkable targeting property toward hepatocarcinoma cells and tumor. Enhanced anti-HCC efficacy of the micelles was also confirmed both in vitro and in vivo. Therefore, this micellar system may be a potential platform of chemotherapeutics delivery for HCC therapy.

Compared with peripheral tumors, glioma is very difficult to treat, not only because it has general features of tumor but also because the therapy has been restricted by the brain-blood barrier (BBB). The two main features of tumor growth are angiogenesis and proliferation of tumor cells. RNA interference (RNAi) can downregulate VEGF overexpression to inhibit tumor neovascularization. Meanwhile, doxorubicin (DOX) has been used for cytotoxic chemotherapy to kill tumor cells. Thus, combining RNAi and chemotherapy has been regarded as a potential strategy for cancer treatment. However, the BBB limits the shVEGF-DOX codelivery system to direct into glioma. Here, a smart drug delivery system modified with a dual functional peptide was established, which could target to transferrin receptor (TfR) overexpressing on both the BBB and glioma. It showed that the dual-targeting delivery system had high tumor targeting efficiency in vitro and in vivo.

Ligand-mediated polymeric micelles have enormous potential for improving the efficacy of glioma therapy. Linear-dendritic drug-polymer conjugates composed of doxorubicin (DOX) and polyethylene glycol (PEG) were synthesized with or without modification of choline derivate (CD). The resulting MeO-PEG-DOX8 and CD-PEG-DOX8 could self-assemble into polymeric micelles with a nanosized diameter around 30 nm and a high drug loading content up to 40.6 and 32.3%, respectively. The optimized formulation 20% CD-PEG-DOX8 micelles had superior cellular uptake and antitumor activity against MeO-PEG-DOX8 micelles. The subcellular distribution using confocal study revealed that 20% CD-PEG-DOX8 micelles preferentially accumulated in the mitochondria. Pharmacokinetic study showed area under the plasma concentration-time curve (AUC0-t) and Cmax for 20% CD-PEG-DOX8 micelles and DOX solution were 1336.58 ± 179.43 mg/L·h, 96.35 ± 3.32 mg/L and 1.40 ± 0.19 mg/L·h, 1.15 ± 0.25 mg/L, respectively. Biodistribution study showed the DOX concentration of 20% CD-PEG-DOX8 micelles treated group at 48 h was 2.37-fold higher than that of MeO-PEG-DOX8 micelles treated group at 48 h and was 24 fold-higher than that of DOX solution treated group at 24 h. CD-PEG-DOX8 micelles (20%) were well tolerated with reduced cardiotoxicity, as evaluated in the body weight change and HE staining studies, while they induced most significant antitumor activity with longest media survival time in an orthotopic mouse model of U87-luci glioblastoma model as displayed in the bioluminescence imaging and survival curve studies. Our findings consequently indicated that 20% CD-PEG-DOX8 micelles are promising drug delivery system for glioma chemotherapy.

In an effort to determine whether there is a major difference in protein level between isoniazid resistant and susceptible Mycobacterium tuberculosis strains, the proteins extracted from nine isoniazid (INH) monoresistant M. tuberculosis strains, seven isoniazid susceptible M. tuberculosis strains, and M. tuberculosis H37Rv, were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). In all protein spot differences, five protein spots that are upregulated in INH-resistant strains were identified as Rv1446c, Rv3028c, Rv0491, Rv2971, and Rv2145 by matrix-assisted laser desorption/ionization-time of fight-mass spectrometry (MALDI-TOF-MS). Most of these differential proteins are membrane proteins, which are known to be rich in potential diagnostic and therapeutic protein targets. These results suggest that the differentially expressed proteins from INH-resistant strains might be used as potential immunodiagnosis antigens and candidate novel drug targets against drug-resistant tuberculosis.