BACKGROUND:The pathogenesis of metabolic dysfunction-associated fatty liver disease (MAFLD) involves gut microbiota dysbiosis. This study investigated pseudolaric acid B (PAB), a diterpenoid from Pseudolarix kaempferi, for its potential to ameliorate MAFLD via microbiota-metabolite-host signaling pathways. METHOD:We evaluated the effects of PAB on MAFLD in high-fat diet (HFD)-fed mice. 16S rRNA sequencing and metabolomics analyzed the regulations of PAB on gut microbiota and metabolites. The fecal microbiota transplantation (FMT) experiment was conducted to validate the causal role of the gut microbiota in the efficacy of PAB. Mechanistic studies employed molecular docking, microscale thermal migration (MST), western blot, immunofluorescence, and PCR to elucidate how PAB alleviates hepatic lipid metabolism dysregulation in MAFLD via microbial metabolites. In vivo intervention with candidate metabolites assessed improvement of disease phenotypes. RESULTS:PAB effectively alleviatd the symptoms of HFD-induced MAFLD in mice, and repaired dysbiosis of intestinal microbiota, especially g_Faecalibaculum, g_Allobaculum, g_Ileibacterium, and g_Dubosiella, which were markedly down-regulated by PAB and showed a positive correlation with liver injury. FMT confirmed the relevance of PAB efficacy to the microbial community structure. Moreover, PAB intervention led to a dramatically enrichment of the tryptophan metabolism pathway, with cinnabarinic acid (CA), a microbial tryptophan metabolite, exhibiting a significat negative correlation with the abundance of the down-regulated bacteria. CA supplementation alleviated HFD-induced MAFLD in mice, indicating the hepatoprotective effect of CA. Molecular docking and MST revealed CA binds stablly to aryl hydrocarbon receptor (AhR) with higher affinity/stability, indicating a direct interaction between them. Mechanistically, PAB increased CA level and then activited AhR, downregulated hepatic lipogenesis genes by AhR-mediated IL-22/JAK1/STAT3 pathway. CONCLUSION:PAB exerts a protective effect against MAFLD via restructuring the gut microbiota ecosystem, and activating CA/AhR/IL-22 signaling axis to reduce lipogenesis. These findings reveal a novel microbiota-metabolite-host mechanism and highlight PAB as a promising prebiotic-based therapeutic candidate for MAFLD.

[This retracts the article DOI: 10.1007/s10616-013-9534-x.].

The complex characteristics of the tumor microenvironment (TME), such as hypoxia, elevated reactive oxygen species (ROS) levels, and immune suppression, provide opportunities for developing synergistic therapeutic strategies. This study presents a cascade-responsive nanoplatform tailored to TME features, integrating photodynamic therapy (PDT), chemotherapy, and immunotherapy to achieve multifaceted synergy. The platform comprises two functional nanoparticles: (1) IR808/ Resiquimod prodrug nanoparticles (IR808/R848-PRO NPs), which, upon NIR (near-infrared) light activation, initiate PDT to produce ROS, triggering the release of the immunomodulator R848 and exacerbating TME hypoxia; (2) Doxorubicin prodrug nanoparticles (DOX-PRO NPs), which utilize hypoxia-sensitive azo bonds to precisely release DOX, enabling chemotherapeutic killing and immunogenic cell death (ICD). ROS generated by PDT not only facilitates R848 release but also enhances DOX-PRO drug release efficiency by aggravating hypoxia. Simultaneously, the ICD effect induced by DOX amplifies the immune activation triggered by R848, resulting in a synergistic enhancement. In vitro and in vivo experiments demonstrated that this platform effectively promotes dendritic cell maturation, polarizes tumor-associated macrophages (TAMs), and enhances T-cell responses, significantly suppressing tumor growth with good biocompatibility. This study proposes an innovative multifunctional nanoplatform, offering a novel strategy for treating tumors with hypoxia and immune suppression characteristics.

Bombesin receptor subtype-3 (BRS3) is an orphan G protein-coupled receptor (GPCR) that plays critical roles in energy homeostasis, glucose metabolism, and insulin secretion. Recent structural studies have elucidated BRS3 signaling mechanisms using synthetic ligands, including BA1 and MK-5046. However, the molecular basis of BRS3 activation by bioactive natural compounds and their derivatives, particularly those derived from traditional Chinese medicine, remains unclear. Here, we present high-resolution cryogenic electron microscopy (cryo-EM) structures of the human BRS3-Gq complex in both unliganded and active states bound by two herb-derived compounds (DSO-5a and oridonin), at resolutions of 2.9, 2.8, and 2.9 Å, respectively. These structures display distinct ligand recognition patterns between DSO-5a and oridonin. Although both compounds bind to the orthosteric pocket, they differentially engage the interaction network of BRS3, as demonstrated by mutagenesis studies assessing calcium mobilization and inositol phosphate 1 (IP1) accumulation. These findings enhance our understanding of BRS3 activation and provide valuable insights into the development of small-molecule BRS3 modulators with therapeutic potential.

Maintaining pH homeostasis is critical for cellular function across all living organisms. Proton-sensing G protein-coupled receptors (GPCRs), particularly GPR4, play a pivotal role in cellular responses to pH changes. Yet, the molecular mechanisms underlying their proton sensing and activation remain incompletely understood. Here we present high-resolution cryo-electron microscopy structures of GPR4 in complex with G proteins under physiological and acidic pH conditions. Our structures reveal an intricate proton-sensing mechanism driven by a sophisticated histidine network in the receptor's extracellular domain. Upon protonation of key histidines under acidic conditions, a remarkable conformational cascade is initiated, propagating from the extracellular region to the intracellular G protein-coupling interface. This dynamic process involves precise transmembrane helix rearrangements and conformational shifts of conserved motifs, mediated by strategically positioned water molecules. Notably, we discovered a bound bioactive lipid, lysophosphatidylcholine, which has positive allosteric effects on GPR4 activation. These findings provide a comprehensive framework for understanding proton sensing in GPCRs and the interplay between pH sensing and lipid regulation, offering insights into cellular pH homeostasis and potential therapies for pH-related disorders.

The G protein–coupled cysteinyl leukotriene receptor CysLT2R plays intricate roles in the physiology and pathogenesis of inflammation-related processes. It has garnered increasing attention as a potential therapeutic target for atopic asthma, brain injury, central nervous system disorders, and various types of cancer. In this study, we present the cryo-electron microscopy structure of the cysteinyl leukotriene D4 (LTD4)-bound human CysLT2R in complex with a Gα q protein, adopting an active conformation at a resolution of 3.15 Å. The structure elucidates a spacious polar pocket designed to accommodate the two branched negative ends of LTD4 and reveals a lateral ligand access route into the orthosteric pocket located on transmembrane domain helix (TM) 4 and 5. Furthermore, our findings highlight the crucial role of transmembrane domain helix 3 in sensing agonist moieties, representing the pivotal mechanism of receptor activation for both CysLT1R and CysLT2R. Collectively, the insights derived from our structural investigation establish a foundation for comprehending CysLT2R activation by its endogenous ligand LTD4, offering a rational basis for the design of drugs targeting CysLT2R.

Investigating and identifying pathogenic molecules of non-alcoholic fatty liver disease (NAFLD) has become imperative, which would serve as effective targets in the future. We established high-fat diet (HFD)-induced NAFLD model in mice and palmitic acid (PA)-induced model in mouse AML12 cells. The level of miR-218-5p was examined by qRT-PCR, and Elovl5 was identified as the potential target gene of miR-218-5p. The binding relationship between miR-218-5p and Elovl5 was validated by double luciferase reporter gene assay, and inhibition/overexpression of miR-218-5p in vitro. The functional mechanisms of miR-218-5p/Elovl5 in regulating lipogenesis in NAFLD were investigated in vivo and in vitro through gain- and loss-of-function studies. MiR-218-5p was significantly increased, and Elovl5 was decreased in model group. According to the double luciferase reporter and gene interference experiments in AML12 cells, Elovl5 was a target gene of miR-218-5p and its expression was regulated by miR-218-5p. The SREBP1-mediated lipogenesis signaling pathway regulated by Elovl5 was upregulated in model group. Moreover, silencing of miR-218-5p significantly upregulated Elovl5 expression, and suppressed SREBP1 signaling pathway in PA-induced AML-12 cells. Correspondingly, the cell injury, elevated TC, TG contents and lipid droplet accumulation were ameliorated. Furthermore, the effect of miR-218-5p on lipogenesis in vitro and in vivo was obstructed by si-Elovl5, implicating that miR-218-5p promotes lipogenesis by targeting ELOVL5 in NAFLD. miR-218-5p could promote fatty acid synthesis by targeting Elovl5, thereby accelerating the development of NAFLD, which is one of the key pathogenic mechanisms of NAFLD and provides a new molecular target for the management of NAFLD.

Targeted protein degradation technology holds great potential in biomedicine, particularly in treating tumors and other protein-related diseases. Research on intracellular protein degradation using molecular glues and PROTAC technology is leading, while research on the degradation of membrane proteins and extracellular proteins through the lysosomal pathway is still in the preclinical stage. The scarcity of useful targets is an immense limitation to technological advancement, making it essential to explore novel, potentially effective approaches for targeted lysosomal degradation. Here, we employed the glucose transporter Glut1 as an innovative lysosome-targeting receptor and devised the Glut1-Facilitated Lysosomal Degradation (GFLD) strategy. We synthesized potential Glut1 ligands via reversible addition-fragmentation chain transfer (RAFT) polymerization and acquired antibody-glycooligomer conjugates through bioorthogonal reactions as lysosome-targeting protein degradation molecules, utilized in the management of PD-L1 high-expressing triple-negative breast cancer. The glucose transporter Glut1 as a lysosome-targeting receptor exhibits potential for the advancement of a broader array of medications in the future.

The effect of methylprotodioscin (MPD), a steroidal saponin obtained from medicinal plants, on myocardial infarction (MI) remains elusive. In this study, HL-1 and AC16 cells were subjected to injury induced by hypoxic environment, and a mouse model of MI was established by ligating the left anterior descending. MPD significantly increased viabilities and proliferations, improved the stability of MMP, reduced ROS and inflammatory factor levels in hypoxia cardiomyocytes. Moreover, MPD significantly improved cardiac functions, increased the ventricular ejection fraction and short axis shortening rate of mice with MI, reduced the infarction area, alleviated oxidative stress and increased ATPase activities. Then, differentially expressed proteins (DEPs) were discovered and evaluated using tandem mass tag (TMT)-based proteomics and bioinformatics approaches. Compared with sham group, there were 420 DEPs in the cardiac tissue of MI group, likewise, 163 DEPs in MPD group were identified compared to MI group. By validating, the expression of COX6C was elevated in MI group and declined in MPD groups, consistent with the TMT-based proteomics results. Correspondingly, p-NF-κB expression was downregulated, while Nrf2 and SOD expressions were upregulated by MPD. Moreover, si-COX6C transfection blocked the regulatory effects of MPD on COX6C-mediated inflammation and oxidative stress in MI. Our findings indicate that MPD, a naturally occurring active ingredient, could effectively improve cardiac function. Its ability may result from regulating COX6C to reduce oxidative stress and suppress inflammation, suggesting that MPD is very attractive for the treatment of MI.

In this study, the effectiveness of combining short-term starvation (STS or fasting) is investigated with blue light illumination therapy in delaying the progression of various types of cancer, including osteosarcoma, cervical, breast, liver carcinoma, and melanoma cancer in animal models. Moreover, the comparative analysis between cancerous (including HeLa, 143B, MDA-MB-231, and HepG2) and normal cell lines (including NCM460, HEKa, and L-O2), highlights the selectivity of the treatment's cytotoxic effects, favoring cancer cells while largely sparing normal cells. In HeLa cancer cells, treatment with the STS and blue light illumination combination resulted in increased phosphorylation of JNK and p38, which led to the activation of downstream signalling substrates, such as p53 and H2AX. This activation induced mitochondrial and nuclear damage, ultimately leading to tumor cell death. The combination treatment also caused metabolic disorders in tumor cells, which interfered with biomolecule availability and selectively induced lethal effects in tumor cells. Therefore, the combination treatment can be an effective strategy for eliminating cancer.

Controlled drug release of nanoparticles was achieved by irreversibly disrupting polymer micelles through high-intensity focused ultrasound (HIFU) induction. An ultrasound-responsive block copolymer was synthesized, comprising an end-functional Eosin Y fluorophore, 2-tetrahydropyranyl acrylate (THPA), and acrylate mannose (MAN). The block copolymer was then self-assembled to produce micelles. The chemotherapy drug dasatinib (DAS) and the sonodynamic therapy agent methylene blue (MB) were encapsulated by the self-assembly of the block copolymer. This targeted nanoparticle enables sonodynamic therapy through high-intensity focused ultrasound while triggering nanoparticle disassembly for controlled drug release. The ultrasound-mediated, non-invasive strategy provides external spatiotemporal control for targeted tumour treatment.

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Gemcitabine (Gem) has been a key chemotherapy agent for pancreatic cancer treatment by suppressing cell proliferation and inducing apoptosis. However, the overexpression of inhibitors of apoptosis (IAP) family of proteins during the carcinogenesis of pancreatic cancer can develop resistance to chemotherapy treatment and result in poor efficacy. To achieve the synergistic combinations of multiple strategies for this dismal disease, we developed a robust nanomedicine system, consisting of a photodynamic therapeutic agent (chlorine e6, Ce6) and a pro-apoptotic peptide-Gem conjugate. To have spatiotemporally controlled drug release, the pro-apoptotic peptide-Gem conjugate was designed to have a vinyldithioether linker that was sensitive to reactive oxygen species (ROS). The nanomedicine was fabricated by the direct self-assembly of the pro-apoptotic peptide-Gem conjugate with Ce6. After being delivered into tumors, the nanomedicine disassembled and rapidly released Gem, Ce6, and the pro-apoptotic peptide upon light illumination (660 nm). Both in vitro and in vivo studies in pancreatic cancer models confirmed the tumor inhibition efficacy with low systemic toxicity to animals.

ABSTRACT: A robust aggregation-induced emission luminogen photoaddition-fragmentation chain transfer (PET-RAFT) polymerization was investigated. A variety of well-defined polymers with narrow polydispersities (D < 1.20) were prepared using the donor-acceptor (D-A) type aggregation-induced emission luminogen as a photocatalyst (as low as 5 ppm with respect to monomers) under visible light at ambient temperature. The use of ppm level of metal- or organo-photocatalysts for PET-RAFT polymerization has been investigated before, but mainly in organic solvents, and very much fewer studies were reported in aqueous environments. The polymerization strategy was successfully demonstrated in water with or without oxygen-free conditions and resulted in structure-controlled polymers. We observed that the fluorescence of DCDPP-2TPA was intensified linearly with an increase in the degree of polymerization.

医学培养模式的转变,是以医学人文教育为重点,培养新时代德才兼备应用型医药人才为目标.药理学是基础医学与临床医学之间的桥梁学科,充分运用"互联网+"技术,因材施教,课堂内外以不同的形式实践人文教育,激发学生的使命感和责任感.将人文精神的培养贯穿于医学教育的始终,提高当代医学生对人类生存意义与价值的关怀与认识,培养具有较高人文素养的新一代医学人才.

以药剂学课程为例,介绍大连医科大学药学院2020年春季学期进行线上教学的优势、面临的困境以及解决对策,为将来开展线上与线下结合教学提供思路,达到理想的教学效果.

Photocages for protection and controlled release of bioactive compounds have been widely investigated. However, the vast majority of these photocages have employed the cleavage of single bonds and high-energy ultraviolet light. The construction of a photoactivation system that uses a visible light to cleave unsaturated bonds still remains a challenge. Herein, we report a regioselective oxidative cleavage of C=C bond from a boron-dipyrrolemethene (BODIPY) based photocage by the illumination at 630 nm, resulting in a free aldehyde and a thiol fluorescent probe. This strategy was demonstrated in living HeLa cells and the generated α-formyl-BODIPY allowed the real-time monitoring aldehyde release in the cells. In particular, we showed a mannose functionalized photocage can target HepG2 cells.