Pyridine-appended disulfidephospholipids enable exceptionally high drug loading and stability as a robust liposomal platform.

Low drug loading and instability of liposomes are two main challenges in the clinic. Herein, a liposomal platform from alternative pyridine-appended disulfidephospholipid (Pyr-SS-PC) was developed for delivering camptothecin (CPT) with high loading and stability. These Pyr-SS-PC lipids with π-π stacking open a general gate in the delivery of aromatic ring-containing drugs.

The combination therapy of oncolytic HSV-1 armed with anti-PD-1 antibody and IL-12 enhances anti-tumor efficacy.

Cancer immunotherapy is a new therapeutic strategy for cancer treatment that targets tumors by improving or restoring immune system function. Therapies targeting immune checkpoint molecules have exerted potent anti-tumor effects and prolonged the overall survival rate of patients. However, only a small number of patients benefit from the treatment. Oncolytic viruses exert anti-tumor effects by regulating the tumor microenvironment and affecting multiple steps of tumor immune circulation. In this study, we engineered two oncolytic viruses that express mouse anti-PD-1 antibody (VT1093M) or mouse IL-12 (VT1092M). We found that both oncolytic viruses showed significant anti-tumor effects in a murine CT26 colon adenocarcinoma model. Importantly, the intratumoral combined injection with VT1092M and VT1093M inhibited growth of the primary tumor, prevented growth of the contralateral untreated tumor, produced a vaccine-like response, activated antigen-specific T cell responses and prolonged the overall survival rate of mice. These results indicate that combination therapy with the engineered oncolytic virus may represent a potent immunotherapy strategy for cancer patients, especially those resistant to PD-1/PD-L1 blockade therapy.

The oncolytic virus VT09X optimizes immune checkpoint therapy in low immunogenic melanoma.

Tumors with a low level of pre-existing immune cell infiltration respond poorly to immune checkpoint therapies. Oncolytic viruses optimize immunotherapies by modulating the tumor microenvironment and affecting multiple steps in the cancer-immunity cycle, making them an attractive agent for combination strategies. We engineered an HSV-1-based oncolytic virus and investigated its antitumor effects in combination with the marketed PD-1 antibody Keytruda (pembrolizumab) in hPD-1 knock-in mice bearing non-immunogenic B16-F10 melanoma. Our results showed enhanced CD8+ and CD4+ T cell infiltration, IFN-γ secretion and PD-L1 expression in tumors, subsequently leading to the prolonged overall survival of mice. Systemic changes in lymphocyte cell proportions were also observed in the peripheral blood. In summary, these findings provide evidence that oncolytic viruses can be engineered as a potential platform for combination therapies, especially to treat tumors that are poorly responsive to immune checkpoint therapy.

Enzymatic Synthesis of Unnatural Ginsenosides Using a Promiscuous UDP-Glucosyltransferase from Bacillus subtilis.

Glycosylation, which is catalyzed by UDP-glycosyltransferases (UGTs), is an important biological modification for the structural and functional diversity of ginsenosides. In this study, the promiscuous UGT109A1 from Bacillus subtilis was used to synthesize unnatural ginsenosides from natural ginsenosides. UGT109A1 was heterologously expressed in Escherichia coli and then purified by Ni-NTA affinity chromatography. Ginsenosides Re, Rf, Rh1, and R1 were selected as the substrates to produce the corresponding derivatives by the recombinant UGT109A1. The results showed that UGT109A1 could transfer a glucosyl moiety to C3-OH of ginsenosides Re and R1, and C3-OH and C12-OH of ginsenosides Rf and Rh1, respectively, to produce unnatural ginsenosides 3,20-di-O-ß-d-glucopyranosyl-6-O-[α-l-rhamnopyrano-(1→2)-ß-d-glucopyranosyl]-dammar-24-ene-3ß,6α,12ß,20S-tetraol (1), 3,20-di-O-ß-d-glucopyranosyl-6-O-[ß-d-xylopyranosyl-(1→2)-ß-d-glucopyranosyl]-dammar-24-ene-3ß,6α,12ß,20S-tetraol (6), 3-O-ß-d-glucopyranosyl-6-O-[ß-d-glucopyranosyl-(1→2)-ß-d-glucopyranosyl]-dammar-24-ene-3ß,6α,12ß,20S-tetraol (3), 3,12-di-O-ß-d-glucopyranosyl-6-O-[ß-d-glucopyranosyl-(1→2)-ß-d-glucopyranosyl]-dammar-24-ene-3ß,6α,12ß,20S-tetraol (2), 3,6-di-O-ß-d-glucopyranosyl-dammar-24-ene-3ß,6α,12ß,20S-tetraol (5), and 3,6,12-tri-O-ß-d-glucopyranosyl-dammar-24-ene-3ß,6α,12ß,20S-tetraol (4). Among the above products, 1, 2, 3, and 6 are new compounds. The maximal activity of UGT109A1 was achieved at the temperature of 40 °C, in the pH range of 8.0⁻10.0. The activity of UGT109A1 was considerably enhanced by Mg2+, Mn2+, and Ca2+, but was obviously reduced by Cu2+, Co2+, and Zn2+. The study demonstrated that UGT109A1 was effective in producing a series of unnatural ginsenosides through enzymatic reactions, which could pave a way to generate promising leads for new drug discovery.

Progress on the Studies of the Key Enzymes of Ginsenoside Biosynthesis.

As the main bioactive constituents of Panax species, ginsenosides possess a wide range of notable medicinal effects such as anti-cancer, anti-oxidative, antiaging, anti-inflammatory, anti-apoptotic and neuroprotective activities. However, the increasing medical demand for ginsenosides cannot be met due to the limited resource of Panax species and the low contents of ginsenosides. In recent years, biotechnological approaches have been utilized to increase the production of ginsenosides by regulating the key enzymes of ginsenoside biosynthesis, while synthetic biology strategies have been adopted to produce ginsenosides by introducing these genes into yeast. This review summarizes the latest research progress on cloning and functional characterization of key genes dedicated to the production of ginsenosides, which not only lays the foundation for their application in plant engineering, but also provides the building blocks for the production of ginsenosides by synthetic biology.

[Epidemiology characteristics of crawfish related rhabdomyolysis in Nanjing, 2016: a multicenter retrospective investigation].

OBJECTIVE: To investigate the epidemiology characteristics of crawfish related rhabdomyolysis (RM) in Nanjing, 2016. METHODS: Outpatient and inpatient electronic medical system of 21 hospitals in Nanjing during 2016 were retrospectively searched, and all the patients diagnosed with RM were selected. The patients with none crayfish-related RM was excluded. The epidemiology characteristics were depicted. The geographic information system (GIS) was used to collect, manage and analyze the spatial data, to visualize it, to analyze the spatial distribution features of the disease, and to explore the cause of disease prediction. GeoDa 1.8 software was used to analyze the global and local spatial auto-correlation. RESULTS: A total of 1 183 patients with crawfish related RM were initially screened, excluding 59 patients with RM caused by trauma, severe exercise, heat stroke, myositis, poisoning, drugs, and genetic diseases, and 1 124 patients were enrolled. The proportion of men was 36.48% (410/1 124) with an incidence of 12.54/100 thousands; while of women was 63.52% (714/1 124) with an incidence of 21.86/100 thousands. The median age at onset was 34 (28, 43) years. From July to August, the incidence of crawfish related RM was the highest, accounting for 96.53% of the total number of cases. The top four incidence areas were Pukou (41.54/100 thousands), Jianye (25.94/100 thousands), Qixia (25.73/100 thousands), Gulou (25.04/100 thousands), all of which were adjacent to the Yangtze River. Global spatial autocorrelation analysis showed: Moran I = 0.427, Z = 2.646, P = 0.003, suggesting that the crawfish related RM had positive spatial autocorrelation. The results showed that the spatial structure of crawfish related RM existed in Nanjing in 2016. Local spatial autocorrelation analysis showed that the "high-high" concentration areas were Pukou, Jianye and Liuhe. The incidences of above three areas which were the Nanjing section of the lower reaches of the Yangtze River flowed through the region and surrounding areas were higher than the overall incidence of Nanjing. CONCLUSIONS: The prevalence of crawfish related RM in Nanjing during 2016 had an obvious region-concentrated character and global spatial autocorrelation with the high prevalent regions mainly concentrated in the urban areas adjacent to the Yangtze River.

Production of a bioactive unnatural ginsenoside by metabolically engineered yeasts based on a new UDP-glycosyltransferase from Bacillus subtilis.

Ginsenosides are the main bioactive constituents of Panax species, which are biosynthesized by glycosylation at C3-OH and/or C20-OH of protopanaxadiol (PPD), C6-OH and/or C20-OH of protopanaxatriol (PPT). The C12-glycosylated ginsenosides have scarcely been identified from Panax species. The C12-glycosylated ginsenosides produced from PPD by chemical semi-synthesis have been reported to exhibit higher cytotoxicity than the natural ginsenosides. However, the chemical semi-synthesis approach is not practical due to its complexity and high cost. In our study, a new UDP-glycosyltransferase UGT109A1 was identified from Bacillus subtilis. This enzyme transferred a glucose moiety to C3-OH and C20-OH of dammarenediol-II (DM), C3-OH and C12-OH of PPD and PPT respectively to produce the unnatural ginsenosides 3ß-O-Glc-DM, 3ß,20S-Di-O-Glc-DM, 3ß,12ß-Di-O-Glc-PPD and 3ß,12ß-Di-O-Glc-PPT. Among these unnatural ginsenosides, 3ß,12ß-Di-O-Glc-PPT is a new compound which has never been reported before. The anti-cancer activities of these unnatural ginsenosides were evaluated in vitro and in vivo. 3ß,12ß-Di-O-Glc-PPD exhibited higher anti-lung cancer activity than Rg3, which is the most active natural ginsenoside against lung cancer. Finally, we constructed metabolically engineered yeasts to produce 3ß,12ß-Di-O-Glc-PPD by introducing the genes encoding B. subtilis UGT109A1, Panax ginseng dammarenediol-II synthase (DS), P. ginseng cytochrome P450-type protopanaxadiol synthase (PPDS) together with Arabidopsis thaliana NADPH-cytochrome P450 reductase (ATR1) into Saccharomyces cerevisiae INVSc1. The yield of 3ß,12ß-Di-O-Glc-PPD was increased from 6.17mg/L to 9.05mg/L by overexpressing tHMG1. Thus, this study has established an alternative route to produce the unnatural ginsenoside 3ß,12ß-Di-O-Glc-PPD by synthetic biology strategies, which provides a promising candidate for anti-cancer drug discovery.

[Expression, subcellular localization and characterization of dammarenediol-â ¡ synthase of Panax ginseng in Saccharomyces cerevisiae].

To study the expression and subcellular localization of recombinant dammarenediol-Ⅱ synthase (DS) in Saccharomyces cerevisiae, the dammarenediol-Ⅱ synthase gene ds was cloned from Panax ginseng, and the gene ds was fused with the gene of green fluorescent protein to obtain the fusion gene ds-gfp. The recombinant expression plasmids pESC-HIS-DS and pESC-HIS-DS-GFP were constructed and transformed into S. cerevisiae INVSc1 to obtain recombinant strains INVSc1-DS and INVSc1-DS-GFP. Microsomes of recombinant strains were prepared by differential centrifugation and observed by fluorescence microscope. The green fluorescence was only detected in INVSc1-DS-GFP microsomes, which indicated that DS was a membrane protein. It was also proved that dammarenediol-Ⅱ was produced from the cyclization of 2,3-oxidosqualene catalyzed by DS through in vitro enzymatic reaction. In addition, our results revealed that the fusion expression of ds with gfp significantly improved the production of dammarenediol-Ⅱ from 7.53 mg·g(-1) to 12.24 mg·g(-1). This study provides a new strategy in the optimization of the pathway of ginsenosides biosynthesis in S.cerevisiae.

Pneumomediastinum from acute inhalation of chlorine gas in 2 young patients.

Trichloroisocyanuric acid is a high-efficiency and-low toxicity fungicide and bleach. It is commonly used as disinfectant for industrial circulating water, swimming pools, restaurants, and other public places in China. When trichloroisocyanuric acid is put into water, chlorine gas is produced. Chlorine gas is a potent pulmonary irritant that causes acute damage in both the upper and lower respiratory tracts (J Toxicol Clin Toxicol. 1998;36(1-2):87-93). Pneumomediastinum is a rare complication in patients with acute chlorine gas poisoning. A small amount of gas can be asymptomatic, but a large amount of gas entering the mediastinum suddenly will lead to respiratory and circulatory disorder, mediastinal swing, or even cardiopulmonary arrest. Severe chlorine gas poisoning patients usually need mechanical ventilation; if the pneumomediastinum is not found on time, threat to life would be greatly increased. It requires a high index of suspicion for diagnosis and rapid treatment. The proper use of ventilator, timely and effective treatment of original disease, and multiple system organ support had significant impact on the prognosis. The pneumomediastinum case secondary to inhalation of chlorine gas that we report here should remind all emergency department physicians to maintain a high index of suspicion for this disease and seek immediate and proper intervention when treating patients with acute chlorine gas poisoning, once diagnosed, especially in younger patients.