Developing fungal heterologous expression platforms to explore and improve the production of natural products from fungal biodiversity.

Natural products from fungi represent an important source of biologically active metabolites notably for therapeutic agent development. Genome sequencing revealed that the number of biosynthetic gene clusters (BGCs) in fungi is much larger than expected. Unfortunately, most of them are silent or barely expressed under laboratory culture conditions. Moreover, many fungi in nature are uncultivable or cannot be genetically manipulated, restricting the extraction and identification of bioactive metabolites from these species. Rapid exploration of the tremendous number of cryptic fungal BGCs necessitates the development of heterologous expression platforms, which will facilitate the efficient production of natural products in fungal cell factories. Host selection, BGC assembly methods, promoters used for heterologous gene expression, metabolic engineering strategies and compartmentalization of biosynthetic pathways are key aspects for consideration to develop such a microbial platform. In the present review, we summarize current progress on the above challenges to promote research effort in the relevant fields.

Anthocyanins Are Converted into Anthocyanidins and Phenolic Acids and Effectively Absorbed in the Jejunum and Ileum.

Anthocyanins have been known for their health benefits. However, the in vivo digestion and absorption of anthocyanins through the gastrointestinal tract have not been fully clarified, creating challenges for understanding why anthocyanins have high biological activities and purported low bioavailability in vivo. Twenty-seven male rats were intubated with a 500 mg/kg dose of cyanidin-3-glucoside (C3G). Samples from rats' stomach, duodenum, jejunum, ileum, colon, and serum were collected at 0.5, 1, 2, 3, 4, 5, 6, 12, and 24 h after intubation. Three rats without C3G were used as the control with samples collected at 0 h. C3G and its metabolites in each sample were analyzed using high-performance liquid chromatography-PDA-electrospray ionization-MS/MS. These in vivo studies' results unequivocally demonstrated that cyanidin and phenolic acids were the primary C3G metabolites absorbed, mainly in the jejunum and ileum, between 1 and 5 h post-ingestion. We speculate that C3G uses phloroglucinaldehyde and protocatechuic acid metabolic pathways in its metabolism in vivo.

Binding of HIV-1 gp120 to DC-SIGN promotes ASK-1-dependent activation-induced apoptosis of human dendritic cells.

During disease progression to AIDS, HIV-1 infected individuals become increasingly immunosuppressed and susceptible to opportunistic infections. It has also been demonstrated that multiple subsets of dendritic cells (DC), including DC-SIGN⁺ cells, become significantly depleted in the blood and lymphoid tissues of AIDS patients, which may contribute to the failure in initiating effective host immune responses. The mechanism for DC depletion, however, is unclear. It is also known that vast quantities of viral envelope protein gp120 are shed from maturing HIV-1 virions and form circulating immune complexes in the serum of HIV-1-infected individuals, but the pathological role of gp120 in HIV-1 pathogenesis remains elusive. Here we describe a previously unrecognized mechanism of DC death in chronic HIV-1 infection, in which ligation of DC-SIGN by gp120 sensitizes DC to undergo accelerated apoptosis in response to a variety of activation stimuli. The cultured monocyte-derived DC and also freshly-isolated DC-SIGN⁺ blood DC that were exposed to either cross-linked recombinant gp120 or immune-complex gp120 in HIV⁺ serum underwent considerable apoptosis after CD40 ligation or exposure to bacterial lipopolysaccharide (LPS) or pro-inflammatory cytokines such as TNFα and IL-1ß. Furthermore, circulating DC-SIGN⁺ DC that were isolated directly from HIV-1⁺ individuals had actually been pre-sensitized by serum gp120 for activation-induced exorbitant apoptosis. In all cases the DC apoptosis was substantially inhibited by DC-SIGN blockade. Finally, we showed that accelerated DC apoptosis was a direct consequence of excessive activation of the pro-apoptotic molecule ASK-1 and transfection of siRNA against ASK-1 significantly prevented the activation-induced excessive DC death. Our study discloses a previously unknown mechanism of immune modulation by envelope protein gp120, provides new insights into HIV immunopathogenesis, and suggests potential therapeutic approaches to prevent DC depletion in chronic HIV infection.

[Multicentric randomized double blinded clinical study of Yiqi Tongmai Oral Liquid against angina pectoris in patients with coronary heart disease].

OBJECTIVE: To study the efficacy and safety of Yiqi Tongmai Oral Liquid (YQTM), a traditional compound Chinese herbal medicine, in treating angina pectoris in patients with coronary heart disease. METHODS: A multicentric, randomized, double blinded and paralleled controlled trial was conducted on 110 patients in trial group treated with YQTM, and 109 patients in control group treated with Shuxin Oral Liquid (SX). Cure and effective rates in both groups were evaluated. Frequency and duration of angina attack were counted and measured. Coronary angiography (CAG), electrocardiogram (ECG) and flat exercise test were taken in both groups. Blood lipid indexes, such as cholesterol (CH), triglyceride (TG), low-density lipoprotein (LDL), high density lipoprotein (HDL), were determined at pre- and post-treatment. The hemodynamic indexes, such as whole blood viscosity (J2), high-shear reduced viscosity (Eh), low-shear reduced viscosity (Ei), red cell aggregation index (Lb), red cell rigidity index (Rh), fibrinogen (Fb), blood sedimentation rate (BSR) and hematocrit (HCT), were determined at pre-and post-treatment. The indicated scores of symptoms and signs of traditional Chinese medicine (TCM) pattern, such as chest pain, chest constriction, breath shortness, palpitation, fatigue, dim complexion, spontaneous perspiration and tongue proper, tongue coating were evaluated in week 0, 1, 2, 3, 4 during the treatment course. The safety indexes, such as body temperature, pulse, respiration and blood pressure were observed. Routine tests of blood, urine and stool, hepatic function test and renal function test were taken at pre- and post-treatment. RESULTS: There was no significant difference between the total effective rate of the trial group and that of the control group, which were 91.82% and 85.32%, respectively (P>0.05). Trial groups percentile of cure rate is significantly higher than that of the control group (P<0.01). The frequency and duration of angina attack, the positive ratio of CAG and flat exercise test of both groups were lowered, while the effect of the trial group on frequency and duration of angina attack was better. No significant difference was found in ECG features between the two groups (P>0.05). The levels of CH, TG and LDL of both groups were lowered significantly (P<0.05). The effect of lowering CH, TG and LDL of the trial group was stronger than that of the control group (P<0.05). The hemodynamic indexes, such as J2, Eh, Ei, Lb, Rh, Fb, BSR and HCT were improved significantly in both groups (P<0.05). The improvements of J2, Eh, Ei, Lb, Rh, Fb and SR in the trial group were greater than those of control group (P<0.05). The TCM symptoms and signs, such as chest pain, chest constriction, breath shortness, palpitation, fatigue, dim complexion, spontaneous perspiration were improved significantly in both groups (P<0.05). The improvements of chest constriction, palpitation, fatigue and spontaneous perspiration in the trial group were greater than those of the control group (P<0.05). The total indicated score of TCM symptoms and signs was lowered more significantly than that of the control group (P<0.01). No significant changes were found at pre- and post-treatment in safety indexes, such as routine tests for blood, urine and stool, hepatic function test and renal function test. There was no significant difference in safety features of both groups (P>0.05). CONCLUSION: Yiqi Tongmai Oral Liquid bears good therapeutic effect on angina pectoris without adverse reaction, and is superior to Shuxin Oral Liquid. Yiqi Tongmai Oral Liquid is a new effective and safe medicine for the treatment of angina pectoris in patients with coronary heart disease.